Attachment 2654 Details for Bug 15838 – linux-2.6.25.4-unionfs-aufs-cvs-20080519.patch

[patch] linux-2.6.25.4-unionfs-aufs-cvs-20080519.patch

linux-2.6.25.4-unionfs-aufs-cvs-20080519.patch (text/plain), 673.97 KB, created by led on 2008-05-30 00:15:51 MSD

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Creator: led

Created: 2008-05-30 00:15:51 MSD

Size: 673.97 KB

patch

obsolete

>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/aufs.h linux-2.6.25.4-unionfs/fs/aufs/aufs.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/aufs.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/aufs.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,53 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * main header files
>+ *
>+ * $Id: aufs.h,v 1.2 2008/04/21 01:31:49 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_H__
>+#define __AUFS_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/version.h>
>+
>+#include "debug.h"
>+
>+#include "branch.h"
>+#include "cpup.h"
>+#include "dcsub.h"
>+#include "dentry.h"
>+#include "dir.h"
>+#include "file.h"
>+#include "hinode.h"
>+#include "inode.h"
>+#include "misc.h"
>+#include "module.h"
>+#include "opts.h"
>+#include "super.h"
>+#include "sysaufs.h"
>+#include "vfsub.h"
>+#include "whout.h"
>+#include "wkq.h"
>+//#include "xattr.h"
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/branch.c linux-2.6.25.4-unionfs/fs/aufs/branch.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/branch.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/branch.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,916 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * branch management
>+ *
>+ * $Id: branch.c,v 1.5 2008/05/19 01:52:18 sfjro Exp $
>+ */
>+
>+#include <linux/iso_fs.h>
>+#include <linux/loop.h>
>+#include <linux/romfs_fs.h>
>+#include <linux/smp_lock.h>
>+#include "aufs.h"
>+
>+static void free_branch(struct au_branch *br)
>+{
>+	AuTraceEnter();
>+
>+	if (br->br_xino)
>+		fput(br->br_xino);
>+	dput(br->br_wh);
>+	dput(br->br_plink);
>+	if (!au_test_nfs(br->br_mnt->mnt_sb))
>+		mntput(br->br_mnt);
>+	else {
>+		lockdep_off();
>+		mntput(br->br_mnt);
>+		lockdep_on();
>+	}
>+	AuDebugOn(au_br_count(br) || atomic_read(&br->br_wh_running));
>+	//AuDbg("free\n");
>+	kfree(br);
>+}
>+
>+/*
>+ * frees all branches
>+ */
>+void au_br_free(struct au_sbinfo *sbinfo)
>+{
>+	aufs_bindex_t bmax;
>+	struct au_branch **br;
>+
>+	AuTraceEnter();
>+	bmax = sbinfo->si_bend + 1;
>+	br = sbinfo->si_branch;
>+	while (bmax--)
>+		free_branch(*br++);
>+}
>+
>+/*
>+ * find the index of a branch which is specified by @br_id.
>+ */
>+int au_br_index(struct super_block *sb, aufs_bindex_t br_id)
>+{
>+	aufs_bindex_t bindex, bend;
>+
>+	AuTraceEnter();
>+
>+	bend = au_sbend(sb);
>+	for (bindex = 0; bindex <= bend; bindex++)
>+		if (au_sbr_id(sb, bindex) == br_id)
>+			return bindex;
>+	return -1;
>+}
>+
>+/*
>+ * test if the @h_sb is real-readonly.
>+ */
>+int au_test_def_rr(struct super_block *h_sb)
>+{
>+	switch (h_sb->s_magic) {
>+#ifdef CONFIG_AUFS_RR_SQUASHFS
>+	case SQUASHFS_MAGIC_LZMA:
>+	case SQUASHFS_MAGIC:
>+	case SQUASHFS_MAGIC_LZMA_SWAP:
>+	case SQUASHFS_MAGIC_SWAP:
>+		return 1; /* real readonly */
>+#endif
>+
>+#if defined(CONFIG_ISO9660_FS) || defined(CONFIG_ISO9660_FS_MODULE)
>+	case ISOFS_SUPER_MAGIC:
>+		return 1;
>+#endif
>+
>+#if defined(CONFIG_CRAMFS) || defined(CONFIG_CRAMFS_MODULE)
>+	case CRAMFS_MAGIC:
>+		return 1;
>+#endif
>+
>+#if defined(CONFIG_ROMFS_FS) || defined(CONFIG_ROMFS_FS_MODULE)
>+	case ROMFS_MAGIC:
>+		return 1;
>+#endif
>+
>+	default:
>+		return 0;
>+	}
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * test if two hidden_dentries have overlapping branches.
>+ */
>+static int do_test_overlap(struct super_block *sb, struct dentry *h_d1,
>+			   struct dentry *h_d2)
>+{
>+	int err;
>+
>+	LKTRTrace("%.*s, %.*s\n", AuDLNPair(h_d1), AuDLNPair(h_d2));
>+
>+	err = au_test_subdir(h_d1, h_d2);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int test_overlap_loopback(struct super_block *sb, struct dentry *h_d1,
>+				 struct dentry *h_d2)
>+{
>+#if defined(CONFIG_BLK_DEV_LOOP) || defined(CONFIG_BLK_DEV_LOOP_MODULE)
>+	struct inode *h_inode;
>+	struct loop_device *l;
>+
>+	h_inode = h_d1->d_inode;
>+	if (MAJOR(h_inode->i_sb->s_dev) != LOOP_MAJOR)
>+		return 0;
>+
>+	l = h_inode->i_sb->s_bdev->bd_disk->private_data;
>+	h_d1 = l->lo_backing_file->f_dentry;
>+	if (unlikely(h_d1->d_sb == sb))
>+		return 1;
>+	return do_test_overlap(sb, h_d1, h_d2);
>+#else
>+	return 0;
>+#endif
>+}
>+
>+static int test_overlap(struct super_block *sb, struct dentry *h_d1,
>+			struct dentry *h_d2)
>+{
>+	LKTRTrace("d1 %.*s, d2 %.*s\n", AuDLNPair(h_d1), AuDLNPair(h_d2));
>+
>+	if (unlikely(h_d1 == h_d2))
>+		return 1;
>+	return do_test_overlap(sb, h_d1, h_d2)
>+		|| do_test_overlap(sb, h_d2, h_d1)
>+		|| test_overlap_loopback(sb, h_d1, h_d2)
>+		|| test_overlap_loopback(sb, h_d2, h_d1);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int init_br_wh(struct super_block *sb, aufs_bindex_t bindex,
>+		      struct au_branch *br, int new_perm,
>+		      struct dentry *h_root, struct vfsmount *h_mnt)
>+{
>+	int err, old_perm;
>+	struct inode *dir, *h_dir;
>+	const int new = (bindex < 0);
>+
>+	LKTRTrace("b%d, new_perm %d\n", bindex, new_perm);
>+
>+	dir = sb->s_root->d_inode;
>+	h_dir = h_root->d_inode;
>+	if (new)
>+		mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
>+	else
>+		au_hdir_lock(h_dir, dir, bindex);
>+
>+	br_wh_write_lock(br);
>+	old_perm = br->br_perm;
>+	br->br_perm = new_perm;
>+	err = au_wh_init(h_root, br, au_do_nfsmnt(h_mnt), sb);
>+	br->br_perm = old_perm;
>+	br_wh_write_unlock(br);
>+
>+	if (new)
>+		mutex_unlock(&h_dir->i_mutex);
>+	else
>+		au_hdir_unlock(h_dir, dir, bindex);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * returns a newly allocated branch. @new_nbranch is a number of branches
>+ * after adding a branch.
>+ */
>+static struct au_branch *alloc_addbr(struct super_block *sb, int new_nbranch)
>+{
>+	struct au_branch **branchp, *add_branch;
>+	int sz;
>+	void *p;
>+	struct dentry *root;
>+	struct inode *inode;
>+	struct au_hinode *hinodep;
>+	struct au_hdentry *hdentryp;
>+
>+	LKTRTrace("new_nbranch %d\n", new_nbranch);
>+	SiMustWriteLock(sb);
>+	root = sb->s_root;
>+	DiMustWriteLock(root);
>+	inode = root->d_inode;
>+	IiMustWriteLock(inode);
>+
>+	add_branch = kmalloc(sizeof(*add_branch), GFP_KERNEL);
>+	//if (LktrCond) {kfree(add_branch); add_branch = NULL;}
>+	if (unlikely(!add_branch))
>+		goto out;
>+
>+	sz = sizeof(*branchp) * (new_nbranch - 1);
>+	if (unlikely(!sz))
>+		sz = sizeof(*branchp);
>+	p = au_sbi(sb)->si_branch;
>+	branchp = au_kzrealloc(p, sz, sizeof(*branchp) * new_nbranch,
>+			       GFP_KERNEL);
>+	//if (LktrCond) branchp = NULL;
>+	if (unlikely(!branchp))
>+		goto out_br;
>+	au_sbi(sb)->si_branch = branchp;
>+
>+	sz = sizeof(*hdentryp) * (new_nbranch - 1);
>+	if (unlikely(!sz))
>+		sz = sizeof(*hdentryp);
>+	p = au_di(root)->di_hdentry;
>+	hdentryp = au_kzrealloc(p, sz, sizeof(*hdentryp) * new_nbranch,
>+				GFP_KERNEL);
>+	//if (LktrCond) hdentryp = NULL;
>+	if (unlikely(!hdentryp))
>+		goto out_br;
>+	au_di(root)->di_hdentry = hdentryp;
>+
>+	sz = sizeof(*hinodep) * (new_nbranch - 1);
>+	if (unlikely(!sz))
>+		sz = sizeof(*hinodep);
>+	p = au_ii(inode)->ii_hinode;
>+	hinodep = au_kzrealloc(p, sz, sizeof(*hinodep) * new_nbranch,
>+			       GFP_KERNEL);
>+	//if (LktrCond) hinodep = NULL; // unavailable test
>+	if (unlikely(!hinodep))
>+		goto out_br;
>+	au_ii(inode)->ii_hinode = hinodep;
>+	return add_branch; /* success */
>+
>+ out_br:
>+	kfree(add_branch);
>+ out:
>+	AuTraceErr(-ENOMEM);
>+	return ERR_PTR(-ENOMEM);
>+}
>+
>+/*
>+ * test if the branch permission is legal or not.
>+ */
>+static int test_br(struct super_block *sb, struct inode *inode, int brperm,
>+		   char *path)
>+{
>+	int err;
>+
>+	err = 0;
>+	if (unlikely(au_br_writable(brperm) && IS_RDONLY(inode))) {
>+		AuErr("write permission for readonly fs or inode, %s\n", path);
>+		err = -EINVAL;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * returns:
>+ * 0: success, the caller will add it
>+ * plus: success, it is already unified, the caller should ignore it
>+ * minus: error
>+ */
>+static int test_add(struct super_block *sb, struct au_opt_add *add, int remount)
>+{
>+	int err;
>+	struct dentry *root;
>+	struct inode *inode, *h_inode;
>+	aufs_bindex_t bend, bindex;
>+
>+	LKTRTrace("%s, remo%d\n", add->path, remount);
>+
>+	root = sb->s_root;
>+	bend = au_sbend(sb);
>+	if (unlikely(bend >= 0
>+		     && au_find_dbindex(root, add->nd.path.dentry) >= 0)) {
>+		err = 1;
>+		if (!remount) {
>+			err = -EINVAL;
>+			AuErr("%s duplicated\n", add->path);
>+		}
>+		goto out;
>+	}
>+
>+	err = -ENOSPC; //-E2BIG;
>+	//if (LktrCond) bend = AUFS_BRANCH_MAX;
>+	if (unlikely(AUFS_BRANCH_MAX <= add->bindex
>+		     || AUFS_BRANCH_MAX - 1 <= bend)) {
>+		AuErr("number of branches exceeded %s\n", add->path);
>+		goto out;
>+	}
>+
>+	err = -EDOM;
>+	if (unlikely(add->bindex < 0 || bend + 1 < add->bindex)) {
>+		AuErr("bad index %d\n", add->bindex);
>+		goto out;
>+	}
>+
>+	inode = add->nd.path.dentry->d_inode;
>+	AuDebugOn(!inode || !S_ISDIR(inode->i_mode));
>+	err = -ENOENT;
>+	if (unlikely(!inode->i_nlink)) {
>+		AuErr("no existence %s\n", add->path);
>+		goto out;
>+	}
>+
>+	err = -EINVAL;
>+	if (unlikely(inode->i_sb == sb)) {
>+		AuErr("%s must be outside\n", add->path);
>+		goto out;
>+	}
>+
>+	if (unlikely(au_test_nested(inode->i_sb))) {
>+		AuErr("nested " AUFS_NAME " %s\n", add->path);
>+		goto out;
>+	}
>+
>+	if (unlikely(!strcmp(au_sbtype(inode->i_sb), "unionfs"))) {
>+		AuErr("unsupported filesystem, %s\n", add->path);
>+		goto out;
>+	}
>+
>+	if (unlikely(au_test_unsupported_nfs(inode->i_sb))) {
>+		AuErr(AuNoNfsBranchMsg " %s\n", add->path);
>+		goto out;
>+	}
>+
>+	err = test_br(sb, add->nd.path.dentry->d_inode, add->perm, add->path);
>+	if (unlikely(err))
>+		goto out;
>+
>+	if (bend < 0)
>+		return 0; /* success */
>+
>+	h_inode = au_h_dptr(root, 0)->d_inode;
>+	if (unlikely(au_opt_test(au_mntflags(sb), WARN_PERM)
>+		     && ((h_inode->i_mode & S_IALLUGO)
>+			 != (inode->i_mode & S_IALLUGO)
>+			 || h_inode->i_uid != inode->i_uid
>+			 || h_inode->i_gid != inode->i_gid)))
>+		AuWarn("uid/gid/perm %s %u/%u/0%o, %u/%u/0%o\n",
>+		       add->path,
>+		       inode->i_uid, inode->i_gid, (inode->i_mode & S_IALLUGO),
>+		       h_inode->i_uid, h_inode->i_gid,
>+		       (h_inode->i_mode & S_IALLUGO));
>+
>+	err = -EINVAL;
>+	for (bindex = 0; bindex <= bend; bindex++)
>+		if (unlikely(test_overlap(sb, add->nd.path.dentry,
>+					  au_h_dptr(root, bindex)))) {
>+			AuErr("%s is overlapped\n", add->path);
>+			goto out;
>+		}
>+	err = 0;
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int au_br_init(struct au_branch *br, struct super_block *sb,
>+		      struct au_opt_add *add)
>+{
>+	int err;
>+
>+	AuTraceEnter();
>+
>+	err = 0;
>+	au_rw_init_nolock(&br->br_wh_rwsem);
>+	br->br_plink = NULL;
>+	br->br_wh = NULL;
>+	if (unlikely(au_br_writable(add->perm))) {
>+		err = init_br_wh(sb, /*bindex*/-1, br, add->perm,
>+				 add->nd.path.dentry, add->nd.path.mnt);
>+		if (unlikely(err))
>+			goto out;
>+	}
>+
>+	br->br_xino = NULL;
>+	br->br_mnt = mntget(add->nd.path.mnt);
>+	if (au_opt_test(au_mntflags(sb), XINO)) {
>+		err = au_xino_br(sb, br, add->nd.path.dentry->d_inode->i_ino,
>+				 au_sbr(sb, 0)->br_xino, /*do_test*/1);
>+		if (unlikely(err)) {
>+			AuDebugOn(br->br_xino);
>+			goto out;
>+		}
>+	}
>+
>+	atomic_set(&br->br_wh_running, 0);
>+	br->br_id = au_new_br_id(sb);
>+	br->br_perm = add->perm;
>+	atomic_set(&br->br_count, 0);
>+	br->br_bytes = 0;
>+	br->br_xino_upper = AUFS_XINO_TRUNC_INIT;
>+	atomic_set(&br->br_xino_running, 0);
>+	sysaufs_br_init(br);
>+	br->br_generation = au_sigen(sb);
>+	//smp_mb(); /* atomic_set */
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_br_add(struct super_block *sb, struct au_opt_add *add, int remount)
>+{
>+	int err, amount;
>+	aufs_bindex_t bend, add_bindex;
>+	struct dentry *root, *dentry;
>+	struct au_iinfo *iinfo;
>+	struct au_sbinfo *sbinfo;
>+	struct au_dinfo *dinfo;
>+	struct inode *root_inode, *inode;
>+	unsigned long long maxb;
>+	struct au_branch **branchp, *add_branch;
>+	struct au_hdentry *hdentryp;
>+	struct au_hinode *hinodep;
>+
>+	dentry = add->nd.path.dentry;
>+	LKTRTrace("b%d, %s, 0x%x, %.*s\n",
>+		  add->bindex, add->path, add->perm, AuDLNPair(dentry));
>+	SiMustWriteLock(sb);
>+	root = sb->s_root;
>+	DiMustWriteLock(root);
>+	root_inode = root->d_inode;
>+	IMustLock(root_inode);
>+	IiMustWriteLock(root_inode);
>+
>+	err = test_add(sb, add, remount);
>+	if (unlikely(err < 0))
>+		goto out;
>+	if (err)
>+		return 0; /* success */
>+
>+	bend = au_sbend(sb);
>+	add_branch = alloc_addbr(sb, bend + 2);
>+	err = PTR_ERR(add_branch);
>+	if (IS_ERR(add_branch))
>+		goto out;
>+	err = au_br_init(add_branch, sb, add);
>+	if (unlikely(err)) {
>+		kfree(add_branch);
>+		goto out;
>+	}
>+
>+	add_bindex = add->bindex;
>+	if (remount)
>+		sysaufs_brs_del(sb, add_bindex);
>+
>+	sbinfo = au_sbi(sb);
>+	dinfo = au_di(root);
>+	iinfo = au_ii(root_inode);
>+
>+	amount = bend + 1 - add_bindex;
>+	branchp = sbinfo->si_branch + add_bindex;
>+	memmove(branchp + 1, branchp, sizeof(*branchp) * amount);
>+	*branchp = add_branch;
>+	hdentryp = dinfo->di_hdentry + add_bindex;
>+	memmove(hdentryp + 1, hdentryp, sizeof(*hdentryp) * amount);
>+	au_h_dentry_init(hdentryp);
>+	hinodep = iinfo->ii_hinode + add_bindex;
>+	memmove(hinodep + 1, hinodep, sizeof(*hinodep) * amount);
>+	hinodep->hi_inode = NULL;
>+	au_hin_init(hinodep, NULL);
>+
>+	sbinfo->si_bend++;
>+	dinfo->di_bend++;
>+	iinfo->ii_bend++;
>+	if (unlikely(bend < 0)) {
>+		sbinfo->si_bend = 0;
>+		dinfo->di_bstart = 0;
>+		iinfo->ii_bstart = 0;
>+	}
>+	inode = dentry->d_inode;
>+	au_set_h_dptr(root, add_bindex, dget(dentry));
>+	au_set_h_iptr(root_inode, add_bindex, igrab(inode), 0);
>+	if (remount)
>+		sysaufs_brs_add(sb, add_bindex);
>+
>+	if (!add_bindex)
>+		au_cpup_attr_all(root_inode);
>+	else
>+		au_add_nlink(root_inode, inode);
>+	maxb = dentry->d_sb->s_maxbytes;
>+	if (sb->s_maxbytes < maxb)
>+		sb->s_maxbytes = maxb;
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#define AuVerbose(do_info, fmt, args...) do { \
>+	if (!do_info) \
>+		LKTRTrace(fmt, ##args); \
>+	else \
>+		AuInfo(fmt, ##args); \
>+} while (0)
>+
>+/*
>+ * test if the branch is deletable or not.
>+ */
>+static int test_dentry_busy(struct dentry *root, aufs_bindex_t bindex,
>+			    au_gen_t sigen)
>+{
>+	int err, i, j, ndentry, verbose;
>+	struct au_dcsub_pages dpages;
>+	struct au_dpage *dpage;
>+	struct dentry *d;
>+	aufs_bindex_t bstart, bend;
>+	struct inode *inode;
>+
>+	LKTRTrace("b%d, gen%d\n", bindex, sigen);
>+	SiMustWriteLock(root->d_sb);
>+
>+	err = au_dpages_init(&dpages, GFP_TEMPORARY);
>+	if (unlikely(err))
>+		goto out;
>+	err = au_dcsub_pages(&dpages, root, NULL, NULL);
>+	if (unlikely(err))
>+		goto out_dpages;
>+
>+	verbose = !!au_opt_test(au_mntflags(root->d_sb), VERBOSE);
>+	for (i = 0; !err && i < dpages.ndpage; i++) {
>+		dpage = dpages.dpages + i;
>+		ndentry = dpage->ndentry;
>+		for (j = 0; !err && j < ndentry; j++) {
>+			d = dpage->dentries[j];
>+			AuDebugOn(!atomic_read(&d->d_count));
>+			inode = d->d_inode;
>+			AuDebugOn(!inode);
>+			if (au_digen(d) == sigen
>+			    && au_iigen(inode) == sigen)
>+				di_read_lock_child(d, AuLock_IR);
>+			else {
>+				di_write_lock_child(d);
>+				err = au_reval_dpath(d, sigen);
>+				if (!err)
>+					di_downgrade_lock(d, AuLock_IR);
>+				else {
>+					di_write_unlock(d);
>+					break;
>+				}
>+			}
>+
>+			bstart = au_dbstart(d);
>+			bend = au_dbend(d);
>+			if (bstart <= bindex
>+			    && bindex <= bend
>+			    && au_h_dptr(d, bindex)
>+			    && (!S_ISDIR(d->d_inode->i_mode)
>+				|| bstart == bend)) {
>+				err = -EBUSY;
>+				AuVerbose(verbose, "busy %.*s\n", AuDLNPair(d));
>+			}
>+			di_read_unlock(d, AuLock_IR);
>+		}
>+	}
>+
>+ out_dpages:
>+	au_dpages_free(&dpages);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int test_inode_busy(struct super_block *sb, aufs_bindex_t bindex,
>+			   au_gen_t sigen)
>+{
>+	int err, verbose;
>+	struct inode *i;
>+	aufs_bindex_t bstart, bend;
>+
>+	LKTRTrace("b%d, gen%d\n", bindex, sigen);
>+	SiMustWriteLock(sb);
>+
>+	err = 0;
>+	verbose = !!au_opt_test(au_mntflags(sb), VERBOSE);
>+	list_for_each_entry(i, &sb->s_inodes, i_sb_list) {
>+		AuDebugOn(!atomic_read(&i->i_count));
>+		if (!list_empty(&i->i_dentry))
>+			continue;
>+
>+		if (au_iigen(i) == sigen)
>+			ii_read_lock_child(i);
>+		else {
>+			ii_write_lock_child(i);
>+			err = au_refresh_hinode_self(i);
>+			if (!err)
>+				ii_downgrade_lock(i);
>+			else {
>+				ii_write_unlock(i);
>+				break;
>+			}
>+		}
>+
>+		bstart = au_ibstart(i);
>+		bend = au_ibend(i);
>+		if (bstart <= bindex
>+		    && bindex <= bend
>+		    && au_h_iptr(i, bindex)
>+		    && (!S_ISDIR(i->i_mode) || bstart == bend)) {
>+			err = -EBUSY;
>+			AuVerbose(verbose, "busy i%lu\n", i->i_ino);
>+			//au_debug_on();
>+			//DbgInode(i);
>+			//au_debug_off();
>+			ii_read_unlock(i);
>+			break;
>+		}
>+		ii_read_unlock(i);
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int test_children_busy(struct dentry *root, aufs_bindex_t bindex)
>+{
>+	int err;
>+	au_gen_t sigen;
>+
>+	LKTRTrace("b%d\n", bindex);
>+	SiMustWriteLock(root->d_sb);
>+	DiMustWriteLock(root);
>+	//todo: dont trust BKL.
>+	AuDebugOn(!kernel_locked());
>+
>+	sigen = au_sigen(root->d_sb);
>+	DiMustNoWaiters(root);
>+	IiMustNoWaiters(root->d_inode);
>+	di_write_unlock(root);
>+	err = test_dentry_busy(root, bindex, sigen);
>+	if (!err)
>+		err = test_inode_busy(root->d_sb, bindex, sigen);
>+	di_write_lock_child(root); /* aufs_write_lock() calls ..._child() */
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_br_del(struct super_block *sb, struct au_opt_del *del, int remount)
>+{
>+	int err, do_wh, rerr, verbose;
>+	struct dentry *root;
>+	struct inode *inode, *hidden_dir;
>+	aufs_bindex_t bindex, bend, br_id;
>+	struct au_sbinfo *sbinfo;
>+	struct au_dinfo *dinfo;
>+	struct au_iinfo *iinfo;
>+	struct au_branch *br;
>+	unsigned int mnt_flags;
>+
>+	//au_debug_on();
>+	LKTRTrace("%s, %.*s\n", del->path, AuDLNPair(del->h_root));
>+	SiMustWriteLock(sb);
>+	root = sb->s_root;
>+	DiMustWriteLock(root);
>+	inode = root->d_inode;
>+	IiMustWriteLock(inode);
>+
>+	err = 0;
>+	bindex = au_find_dbindex(root, del->h_root);
>+	if (bindex < 0) {
>+		if (remount)
>+			goto out; /* success */
>+		err = -ENOENT;
>+		AuErr("%s no such branch\n", del->path);
>+		goto out;
>+	}
>+	LKTRTrace("bindex b%d\n", bindex);
>+
>+	err = -EBUSY;
>+	mnt_flags = au_mntflags(sb);
>+	verbose = au_opt_test(mnt_flags, VERBOSE);
>+	bend = au_sbend(sb);
>+	if (unlikely(!bend)) {
>+		AuVerbose(verbose, "no more branches left\n");
>+		goto out;
>+	}
>+	br = au_sbr(sb, bindex);
>+	if (unlikely(au_br_count(br))) {
>+		AuVerbose(verbose, "%d file(s) opened\n", au_br_count(br));
>+		goto out;
>+	}
>+
>+	do_wh = 0;
>+	hidden_dir = del->h_root->d_inode;
>+	if (br->br_wh || br->br_plink) {
>+		dput(br->br_wh);
>+		dput(br->br_plink);
>+		br->br_plink = NULL;
>+		br->br_wh = NULL;
>+		do_wh = 1;
>+	}
>+
>+	err = test_children_busy(root, bindex);
>+	if (unlikely(err)) {
>+		if (unlikely(do_wh))
>+			goto out_wh;
>+		goto out;
>+	}
>+
>+	err = 0;
>+	if (remount)
>+		sysaufs_brs_del(sb, bindex);
>+	sbinfo = au_sbi(sb);
>+	dinfo = au_di(root);
>+	iinfo = au_ii(inode);
>+
>+	dput(au_h_dptr(root, bindex));
>+	au_hiput(iinfo->ii_hinode + bindex);
>+	br_id = br->br_id;
>+	free_branch(br);
>+
>+	//todo: realloc and shrink memory
>+	if (bindex < bend) {
>+		const aufs_bindex_t n = bend - bindex;
>+		struct au_branch **brp;
>+		struct au_hdentry *hdp;
>+		struct au_hinode *hip;
>+
>+		brp = sbinfo->si_branch + bindex;
>+		memmove(brp, brp + 1, sizeof(*brp) * n);
>+		hdp = dinfo->di_hdentry + bindex;
>+		memmove(hdp, hdp + 1, sizeof(*hdp) * n);
>+		hip = iinfo->ii_hinode + bindex;
>+		memmove(hip, hip + 1, sizeof(*hip) * n);
>+	}
>+	sbinfo->si_branch[0 + bend] = NULL;
>+	dinfo->di_hdentry[0 + bend].hd_dentry = NULL;
>+	iinfo->ii_hinode[0 + bend].hi_inode = NULL;
>+	au_hin_init(iinfo->ii_hinode + bend, NULL);
>+
>+	sbinfo->si_bend--;
>+	dinfo->di_bend--;
>+	iinfo->ii_bend--;
>+	if (remount)
>+		sysaufs_brs_add(sb, bindex);
>+
>+	if (!bindex)
>+		au_cpup_attr_all(inode);
>+	else
>+		au_sub_nlink(inode, del->h_root->d_inode);
>+	if (au_opt_test(mnt_flags, PLINK))
>+		au_plink_half_refresh(sb, br_id);
>+
>+	if (sb->s_maxbytes == del->h_root->d_sb->s_maxbytes) {
>+		bend--;
>+		sb->s_maxbytes = 0;
>+		for (bindex = 0; bindex <= bend; bindex++) {
>+			unsigned long long maxb;
>+			maxb = au_sbr_sb(sb, bindex)->s_maxbytes;
>+			if (sb->s_maxbytes < maxb)
>+				sb->s_maxbytes = maxb;
>+		}
>+	}
>+	goto out; /* success */
>+
>+ out_wh:
>+	/* revert */
>+	rerr = init_br_wh(sb, bindex, br, br->br_perm, del->h_root, br->br_mnt);
>+	if (rerr)
>+		AuWarn("failed re-creating base whiteout, %s. (%d)\n",
>+		       del->path, rerr);
>+ out:
>+	AuTraceErr(err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+static int do_need_sigen_inc(int a, int b)
>+{
>+	return (au_br_whable(a) && !au_br_whable(b));
>+}
>+
>+static int need_sigen_inc(int old, int new)
>+{
>+	return (do_need_sigen_inc(old, new)
>+		|| do_need_sigen_inc(new, old));
>+}
>+
>+int au_br_mod(struct super_block *sb, struct au_opt_mod *mod, int remount,
>+	      int *do_update)
>+{
>+	int err;
>+	struct dentry *root;
>+	aufs_bindex_t bindex;
>+	struct au_branch *br;
>+	struct inode *hidden_dir;
>+
>+	LKTRTrace("%s, %.*s, 0x%x\n",
>+		  mod->path, AuDLNPair(mod->h_root), mod->perm);
>+	SiMustWriteLock(sb);
>+	root = sb->s_root;
>+	DiMustWriteLock(root);
>+	IiMustWriteLock(root->d_inode);
>+
>+	bindex = au_find_dbindex(root, mod->h_root);
>+	if (bindex < 0) {
>+		if (remount)
>+			return 0; /* success */
>+		err = -ENOENT;
>+		AuErr("%s no such branch\n", mod->path);
>+		goto out;
>+	}
>+	LKTRTrace("bindex b%d\n", bindex);
>+
>+	hidden_dir = mod->h_root->d_inode;
>+	err = test_br(sb, hidden_dir, mod->perm, mod->path);
>+	if (unlikely(err))
>+		goto out;
>+
>+	br = au_sbr(sb, bindex);
>+	if (br->br_perm == mod->perm)
>+		return 0; /* success */
>+
>+	if (au_br_writable(br->br_perm)) {
>+		/* remove whiteout base */
>+		//todo: mod->perm?
>+		err = init_br_wh(sb, bindex, br, AuBr_RO, mod->h_root,
>+				 br->br_mnt);
>+		if (unlikely(err))
>+			goto out;
>+
>+		if (!au_br_writable(mod->perm)) {
>+			/* rw --> ro, file might be mmapped */
>+			struct file *file, *hf;
>+
>+			DiMustNoWaiters(root);
>+			IiMustNoWaiters(root->d_inode);
>+			di_write_unlock(root);
>+
>+			/*
>+			 * no need file_list_lock()
>+			 * since BKL (and sbinfo) is locked
>+			 */
>+			AuDebugOn(!kernel_locked());
>+			list_for_each_entry(file, &sb->s_files, f_u.fu_list) {
>+				LKTRTrace("%.*s\n", AuDLNPair(file->f_dentry));
>+				if (!au_test_aufs_file(file))
>+					continue;
>+
>+				fi_read_lock(file);
>+				if (!S_ISREG(file->f_dentry->d_inode->i_mode)
>+				    || !(file->f_mode & FMODE_WRITE)
>+				    || au_fbstart(file) != bindex) {
>+					FiMustNoWaiters(file);
>+					fi_read_unlock(file);
>+					continue;
>+				}
>+
>+				if (unlikely(au_test_mmapped(file))) {
>+					err = -EBUSY;
>+					FiMustNoWaiters(file);
>+					fi_read_unlock(file);
>+					break;
>+				}
>+
>+				// todo: already flushed?
>+				hf = au_h_fptr(file, au_fbstart(file));
>+				hf->f_flags = au_file_roflags(hf->f_flags);
>+				hf->f_mode &= ~FMODE_WRITE;
>+				put_write_access(hf->f_dentry->d_inode);
>+				FiMustNoWaiters(file);
>+				fi_read_unlock(file);
>+			}
>+
>+			/* aufs_write_lock() calls ..._child() */
>+			di_write_lock_child(root);
>+		}
>+	}
>+
>+	if (!err) {
>+		*do_update |= need_sigen_inc(br->br_perm, mod->perm);
>+		br->br_perm = mod->perm;
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/branch.h linux-2.6.25.4-unionfs/fs/aufs/branch.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/branch.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/branch.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,324 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * branch filesystems and xino for them
>+ *
>+ * $Id: branch.h,v 1.3 2008/04/28 03:03:32 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_BRANCH_H__
>+#define __AUFS_BRANCH_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/mount.h>
>+#include <linux/sysfs.h>
>+#include <linux/aufs_type.h>
>+#include "misc.h"
>+#include "super.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* an entry in a xino file */
>+struct au_xino_entry {
>+	ino_t ino;
>+	//__u32 h_gen;
>+} __packed;
>+
>+//#define AuXino_INVALID_HGEN	(-1)
>+
>+/* a xino file */
>+struct au_xino_file {
>+	//struct file		**xi_file;
>+	struct file		*xi_file;
>+
>+	/* array management */
>+	//unsigned long long	xi_limit;	/* Max xino file size */
>+	//unsigned long long	xi_size; /* s_maxbytes */
>+
>+	/* truncation */
>+	blkcnt_t		xi_upper;	/* watermark in blocks */
>+	//u64			xi_upper;	/* watermark in bytes */
>+	//u64			xi_step;	/* to next watermark in bytes */
>+	atomic_t 		xi_running;
>+};
>+
>+/* protected by superblock rwsem */
>+struct au_branch {
>+	struct file		*br_xino;
>+	//struct au_xino_file		*br_xino;
>+
>+	aufs_bindex_t		br_id;
>+
>+	int			br_perm;
>+	struct vfsmount		*br_mnt;
>+	atomic_t		br_count;
>+
>+	/* whiteout base */
>+	struct au_rwsem		br_wh_rwsem;
>+	struct dentry		*br_wh;
>+	atomic_t 		br_wh_running;
>+
>+	/* pseudo-link dir */
>+	struct dentry		*br_plink;
>+
>+	/* xino truncation */
>+	blkcnt_t		br_xino_upper;	/* watermark in blocks */
>+	atomic_t		br_xino_running;
>+
>+	/* mfs mode */
>+	u64			br_bytes;
>+
>+#ifdef CONFIG_SYSFS
>+	/* an entry under sysfs per mount-point */
>+	char			br_name[8];
>+	struct attribute	br_attr;
>+#endif
>+
>+	au_gen_t		br_generation;
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* branch permission and attribute */
>+enum {
>+	AuBr_RW,		/* writable, linkable wh */
>+	AuBr_RO,		/* readonly, no wh */
>+	AuBr_RR,		/* natively readonly, no wh */
>+
>+	AuBr_RWNoLinkWH,	/* un-linkable whiteouts */
>+
>+	AuBr_ROWH,
>+	AuBr_RRWH,		/* whiteout-able */
>+
>+	AuBr_Last
>+};
>+
>+static inline int au_br_writable(int brperm)
>+{
>+	return (brperm == AuBr_RW || brperm == AuBr_RWNoLinkWH);
>+}
>+
>+static inline int au_br_whable(int brperm)
>+{
>+	return (brperm == AuBr_RW
>+		|| brperm == AuBr_ROWH
>+		|| brperm == AuBr_RRWH);
>+}
>+
>+static inline int au_br_hinotifyable(int brperm)
>+{
>+#ifdef CONFIG_AUFS_HINOTIFY
>+	return (brperm != AuBr_RR && brperm != AuBr_RRWH);
>+#else
>+	return 0;
>+#endif
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* branch.c */
>+struct au_sbinfo;
>+void au_br_free(struct au_sbinfo *sinfo);
>+int au_test_def_rr(struct super_block *h_sb);
>+int au_br_index(struct super_block *sb, aufs_bindex_t br_id);
>+struct au_opt_add;
>+int au_br_add(struct super_block *sb, struct au_opt_add *add, int remount);
>+struct au_opt_del;
>+int au_br_del(struct super_block *sb, struct au_opt_del *del, int remount);
>+struct au_opt_mod;
>+int au_br_mod(struct super_block *sb, struct au_opt_mod *mod, int remount,
>+	      int *do_update);
>+
>+/* xino.c */
>+int au_xib_trunc(struct super_block *sb);
>+
>+struct file *au_xino_create(struct super_block *sb, char *fname, int silent,
>+			    struct dentry *parent);
>+ino_t au_xino_new_ino(struct super_block *sb);
>+int au_xino_write0(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
>+		   ino_t ino);
>+int au_xino_write(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
>+		  struct au_xino_entry *xinoe);
>+int au_xino_read(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
>+		 struct au_xino_entry *xinoe);
>+int au_xino_br(struct super_block *sb, struct au_branch *br, ino_t hino,
>+	       struct file *base_file, int do_test);
>+int au_xino_trunc(struct super_block *sb, aufs_bindex_t bindex);
>+
>+struct au_opt_xino;
>+int au_xino_set(struct super_block *sb, struct au_opt_xino *xino, int remount);
>+void au_xino_clr(struct super_block *sb);
>+struct file *au_xino_def(struct super_block *sb);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+//todo: memory barrier?
>+static inline int au_br_count(struct au_branch *br)
>+{
>+	return atomic_read(&br->br_count);
>+}
>+
>+static inline int au_br_get(struct au_branch *br)
>+{
>+	return atomic_inc_return(&br->br_count);
>+}
>+
>+static inline int au_br_put(struct au_branch *br)
>+{
>+	return atomic_dec_return(&br->br_count);
>+}
>+
>+static inline au_gen_t au_br_gen(struct au_branch *br)
>+{
>+	return br->br_generation;
>+}
>+
>+/*
>+ * test if the @br is readonly or not.
>+ */
>+static inline int au_br_rdonly(struct au_branch *br)
>+{
>+	return ((br->br_mnt->mnt_sb->s_flags & MS_RDONLY)
>+		|| !au_br_writable(br->br_perm))
>+		? -EROFS : 0;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* Superblock to branch */
>+static inline
>+aufs_bindex_t au_sbr_id(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	return au_sbr(sb, bindex)->br_id;
>+}
>+
>+static inline
>+struct vfsmount *au_sbr_mnt(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	return au_sbr(sb, bindex)->br_mnt;
>+}
>+
>+static inline
>+struct super_block *au_sbr_sb(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	return au_sbr_mnt(sb, bindex)->mnt_sb;
>+}
>+
>+static inline void au_sbr_put(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	au_br_put(au_sbr(sb, bindex));
>+}
>+
>+static inline int au_sbr_perm(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	return au_sbr(sb, bindex)->br_perm;
>+}
>+
>+static inline int au_sbr_whable(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	return au_br_whable(au_sbr_perm(sb, bindex));
>+}
>+
>+static inline int au_test_trunc_xino(struct super_block *sb)
>+{
>+	return au_test_tmpfs(sb);
>+}
>+
>+/* temporary support for i#1 in cramfs */
>+static inline int au_test_unique_ino(struct dentry *h_dentry, ino_t h_ino)
>+{
>+#if defined(CONFIG_CRAMFS) || defined(CONFIG_CRAMFS_MODULE)
>+	if (unlikely(h_dentry->d_sb->s_magic == CRAMFS_MAGIC))
>+		return (h_ino != 1);
>+#endif
>+	return 1;
>+}
>+
>+#ifdef CONFIG_AUFS_BR_NFS
>+static inline int au_test_unsupported_nfs(struct super_block *h_sb)
>+{
>+	return 0;
>+}
>+
>+static inline struct vfsmount *au_do_nfsmnt(struct vfsmount *h_mnt)
>+{
>+	if (!au_test_nfs(h_mnt->mnt_sb))
>+		return NULL;
>+	return h_mnt;
>+}
>+
>+/* it doesn't mntget() */
>+static inline
>+struct vfsmount *au_nfsmnt(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	return au_do_nfsmnt(au_sbr_mnt(sb, bindex));
>+}
>+
>+#define AuNoNfsBranchMsg "dummy"
>+
>+#else
>+static inline int au_test_unsupported_nfs(struct super_block *h_sb)
>+{
>+	return au_test_nfs(h_sb);
>+}
>+
>+static inline struct vfsmount *au_do_nfsmnt(struct vfsmount *h_mnt)
>+{
>+	return NULL;
>+}
>+
>+static inline
>+struct vfsmount *au_nfsmnt(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	return NULL;
>+}
>+
>+#define AuNoNfsBranchMsg "NFS branch is not supported" \
>+	", try some configurations and patches included in aufs source CVS."
>+
>+#endif /* CONFIG_AUFS_BR_NFS */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * br_wh_read_lock, br_wh_write_lock
>+ * br_wh_read_unlock, br_wh_write_unlock, br_wh_downgrade_lock
>+ */
>+AuSimpleRwsemFuncs(br_wh, struct au_branch *br, br->br_wh_rwsem);
>+
>+/* to debug easier, do not make them inlined functions */
>+#define BrWhMustReadLock(br) do { \
>+	/* SiMustAnyLock(sb); */ \
>+	AuRwMustReadLock(&(br)->br_wh_rwsem); \
>+} while (0)
>+
>+#define BrWhMustWriteLock(br) do { \
>+	/* SiMustAnyLock(sb); */ \
>+	AuRwMustWriteLock(&(br)->br_wh_rwsem); \
>+} while (0)
>+
>+#define BrWhMustAnyLock(br) do { \
>+	/* SiMustAnyLock(sb); */ \
>+	AuRwMustAnyLock(&(br)->br_wh_rwsem); \
>+} while (0)
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_BRANCH_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/br_fuse.c linux-2.6.25.4-unionfs/fs/aufs/br_fuse.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/br_fuse.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/br_fuse.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,78 @@
>+/*
>+ * Copyright (C) 2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * special handling for inode attributes on FUSE branch
>+ *
>+ * $Id: br_fuse.c,v 1.2 2008/04/21 01:32:05 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+/* h_mnt can be NULL, is it safe? */
>+int au_update_fuse_h_inode(struct vfsmount *h_mnt, struct dentry *h_dentry)
>+{
>+	int err;
>+	struct kstat st;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(h_dentry));
>+
>+	err = 0;
>+	if (unlikely(h_dentry->d_inode
>+		     //&& atomic_read(&h_dentry->d_inode->i_count)
>+		     && au_test_fuse(h_dentry->d_sb))) {
>+		err = vfsub_getattr(h_mnt, h_dentry, &st, /*dlgt*/0);
>+		if (unlikely(err)) {
>+			AuDbg("err %d\n", err);
>+			au_debug_on();
>+			AuDbgDentry(h_dentry);
>+			au_debug_off();
>+			WARN_ON(err);
>+		}
>+	}
>+	return err;
>+}
>+
>+/* currently, for fuse only */
>+int aufs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *st)
>+{
>+	int err;
>+	struct inode *inode, *h_inode;
>+	struct dentry *h_dentry;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	err = 0;
>+	aufs_read_lock(dentry, AuLock_IR);
>+	inode = dentry->d_inode;
>+	h_inode = au_h_iptr(inode, au_ibstart(inode));
>+	if (unlikely(au_test_fuse(h_inode->i_sb))) {
>+		h_dentry = d_find_alias(h_inode);
>+		/* simply gave up updating fuse inode */
>+		if (h_dentry) {
>+			/*ignore*/
>+			if (!au_update_fuse_h_inode(NULL, h_dentry))
>+				au_cpup_attr_all(inode);
>+			dput(h_dentry);
>+		}
>+	}
>+	generic_fillattr(inode, st);
>+
>+	aufs_read_unlock(dentry, AuLock_IR);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/br_nfs.c linux-2.6.25.4-unionfs/fs/aufs/br_nfs.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/br_nfs.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/br_nfs.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,358 @@
>+/*
>+ * Copyright (C) 2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * lookup functions for NFS branch in linux-2.6.19 and later
>+ *
>+ * $Id: br_nfs.c,v 1.3 2008/05/04 23:51:14 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+static struct file *au_find_h_intent(struct au_hdentry *hd, struct file *file)
>+{
>+	struct file *h_file, *hf;
>+	struct au_hdintent *hdi, *tmp, *do_free;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(hd->hd_dentry));
>+
>+	h_file = NULL;
>+	do_free = NULL;
>+	spin_lock(&hd->hd_lock);
>+	list_for_each_entry_safe(hdi, tmp, hd->hd_intent_list, hdi_list) {
>+		hf = hdi->hdi_file[AuIntent_BRANCH];
>+		if (hdi->hdi_file[AuIntent_AUFS] == file
>+		    && hf->f_dentry == hd->hd_dentry) {
>+			h_file = hf;
>+			do_free = hdi;
>+			list_del(&hdi->hdi_list);
>+			break;
>+		}
>+	}
>+	spin_unlock(&hd->hd_lock);
>+	kfree(do_free);
>+
>+	return h_file;
>+}
>+
>+struct file *au_h_intent(struct dentry *dentry, aufs_bindex_t bindex,
>+			 struct file *file)
>+{
>+	struct file *h_file;
>+	struct au_hdentry *hd = au_di(dentry)->di_hdentry + bindex;
>+
>+	LKTRTrace("%.*s, b%d, f %p\n", AuDLNPair(dentry), bindex, file);
>+	DiMustAnyLock(dentry);
>+	AuDebugOn(bindex < au_di(dentry)->di_bstart
>+		  || bindex > au_di(dentry)->di_bend);
>+
>+	h_file = NULL;
>+	if (!hd->hd_intent_list || !file)
>+		return h_file; /* success */
>+
>+	//AuDebugOn(au_test_wkq(current));
>+	h_file = au_find_h_intent(hd, file);
>+	//AuDbgFile(h_file);
>+	return h_file;
>+}
>+
>+static int au_set_h_intent(struct dentry *dentry, aufs_bindex_t bindex,
>+			   struct file *file, struct file *h_file)
>+{
>+	int err;
>+	struct au_hdentry *hd = au_di(dentry)->di_hdentry + bindex;
>+	struct au_hdintent *hdi;
>+	struct file *hf;
>+
>+	LKTRTrace("%.*s, b%d, f %p\n", AuDLNPair(dentry), bindex, file);
>+	/* d_revalidate() holds read_lock */
>+	//DiMustWriteLock(dentry);
>+	AuDebugOn(bindex < au_di(dentry)->di_bstart
>+		  || bindex > au_di(dentry)->di_bend
>+		  || !file
>+		  || !h_file
>+		  /* || au_test_wkq(current) */);
>+
>+	err = -ENOMEM;
>+	if (hd->hd_intent_list) {
>+		while (1) {
>+			hf = au_find_h_intent(hd, file);
>+			if (!hf)
>+				break;
>+			fput(hf);
>+			AuWarn("freed hfile %.*s b%d left\n",
>+			       AuDLNPair(dentry), bindex);
>+		}
>+	} else {
>+		spin_lock(&hd->hd_lock);
>+		if (!hd->hd_intent_list) {
>+			hd->hd_intent_list
>+				= kmalloc(sizeof(*hd->hd_intent_list),
>+					  GFP_ATOMIC);
>+			if (unlikely(!hd->hd_intent_list)) {
>+				spin_unlock(&hd->hd_lock);
>+				goto out;
>+			}
>+			INIT_LIST_HEAD(hd->hd_intent_list);
>+		}
>+		spin_unlock(&hd->hd_lock);
>+	}
>+
>+	hdi = kmalloc(sizeof(*hdi), GFP_TEMPORARY);
>+	if (unlikely(!hdi))
>+		goto out;
>+
>+	err = 0;
>+	//hdi->hdi_pid = current->pid;
>+	hdi->hdi_file[AuIntent_AUFS] = file;
>+	hdi->hdi_file[AuIntent_BRANCH] = h_file;
>+	spin_lock(&hd->hd_lock);
>+	list_add(&hdi->hdi_list, hd->hd_intent_list);
>+	spin_unlock(&hd->hd_lock);
>+	//AuDbgDentry(dentry);
>+	//AuDbgFile(h_file);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_br_nfs_h_intent(struct file *nd_file, struct dentry *dentry,
>+		       aufs_bindex_t bindex, struct nameidata *nd)
>+{
>+	int err;
>+
>+	AuTraceEnter();
>+
>+	err = 0;
>+	if (!nd_file)
>+		goto out;
>+
>+	AuDebugOn(!nd);
>+	err = au_set_h_intent(dentry, bindex, nd->intent.open.file, nd_file);
>+	//err = -1;
>+	if (unlikely(err)) {
>+		fput(nd_file);
>+		au_set_h_dptr(dentry, bindex, NULL);
>+		//todo: update bstart and bend?
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void au_hintent_put(struct au_hdentry *hd, int do_free)
>+{
>+	struct au_hdintent *hdi, *tmp;
>+	struct file *hf;
>+
>+	if (unlikely(hd->hd_intent_list)) {
>+		// no spin lock
>+		list_for_each_entry_safe(hdi, tmp, hd->hd_intent_list,
>+					 hdi_list) {
>+			LKTRTrace("hdi %p\n", hdi);
>+			hf = hdi->hdi_file[AuIntent_BRANCH];
>+			if (unlikely(hf))
>+				fput(hf);
>+			//list_del(&hdi->hdi_list);
>+			kfree(hdi);
>+		}
>+		if (do_free)
>+			kfree(hd->hd_intent_list);
>+	}
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int au_fake_intent(/* struct au_ndsub *save,  */struct nameidata *nd,
>+		   int perm)
>+{
>+	int err;
>+
>+	LKTRTrace("perm %d\n", perm);
>+
>+	err = 0;
>+
>+	nd->intent.open.file = NULL;
>+	if (nd->flags & LOOKUP_OPEN) {
>+		err = -ENFILE;
>+		nd->intent.open.file = get_empty_filp();
>+		if (unlikely(!nd->intent.open.file)) {
>+			//nd->intent.open.file = save->intent.open.file;
>+			goto out;
>+		}
>+
>+		err = 0;
>+		if (!au_br_writable(perm)) {
>+			nd->intent.open.flags = FMODE_READ
>+				| au_file_roflags(nd->intent.open.flags);
>+			nd->flags &= ~LOOKUP_CREATE;
>+		}
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_hin_after_reval(struct nameidata *nd, struct dentry *dentry,
>+		       aufs_bindex_t bindex, struct file *file)
>+{
>+	int err;
>+
>+	LKTRTrace("nd %p, %.*s, b%d, f %d\n",
>+		  nd, AuDLNPair(dentry), bindex, !!file);
>+
>+	err = 0;
>+	if ((nd->flags & LOOKUP_OPEN)
>+	    && nd->intent.open.file
>+	    && !IS_ERR(nd->intent.open.file)) {
>+		if (nd->intent.open.file->f_dentry) {
>+			//AuDbgFile(nd->intent.open.file);
>+			err = au_set_h_intent(dentry, bindex, file,
>+					      nd->intent.open.file);
>+			if (!err)
>+				nd->intent.open.file = NULL;
>+		}
>+		if (unlikely(nd->intent.open.file))
>+			put_filp(nd->intent.open.file);
>+	}
>+
>+	return err;
>+}
>+
>+#ifdef CONFIG_AUFS_DLGT
>+struct au_lookup_hash_args {
>+	struct dentry **errp;
>+	struct qstr *name;
>+	struct dentry *base;
>+	struct nameidata *nd;
>+};
>+
>+static void au_call_lookup_hash(void *args)
>+{
>+	struct au_lookup_hash_args *a = args;
>+	*a->errp = vfsub__lookup_hash(a->name, a->base, a->nd);
>+}
>+
>+static struct dentry *
>+au_lkup_hash_dlgt(struct qstr *this, struct dentry *parent,
>+		  struct nameidata *nd, unsigned int flags)
>+{
>+	struct dentry *dentry;
>+	int dirperm1;
>+
>+	dirperm1 = au_ftest_ndx(flags, DIRPERM1);
>+	if (!dirperm1 && !au_ftest_ndx(flags, DLGT))
>+		dentry = vfsub__lookup_hash(this, parent, nd);
>+	else {
>+		int wkq_err;
>+		struct au_lookup_hash_args args = {
>+			.errp	= &dentry,
>+			.name	= this,
>+			.base	= parent,
>+			.nd	= nd
>+		};
>+		wkq_err = au_wkq_wait(au_call_lookup_hash, &args,
>+				      /*dlgt*/!dirperm1);
>+		if (unlikely(wkq_err))
>+			dentry = ERR_PTR(wkq_err);
>+	}
>+
>+	AuTraceErrPtr(dentry);
>+	return dentry;
>+}
>+#else
>+static struct dentry *
>+au_lkup_hash_dlgt(struct qstr *this, struct dentry *parent,
>+		  struct nameidata *nd, unsigned int flags)
>+{
>+	return vfsub__lookup_hash(this, parent, nd);
>+}
>+#endif /* CONFIG_AUFS_DLGT */
>+
>+struct dentry *au_lkup_hash(const char *name, struct dentry *parent,
>+			    int len, struct au_ndx *ndx)
>+{
>+	struct dentry *dentry;
>+	char *p;
>+	unsigned long hash;
>+	struct qstr this;
>+	unsigned int c;
>+	struct nameidata tmp_nd, *ndo;
>+	int err;
>+
>+	LKTRTrace("%.*s/%.*s\n", AuDLNPair(parent), len, name);
>+
>+	//todo: export and call __lookup_one_len() in fs/namei.c
>+	dentry = ERR_PTR(-EACCES);
>+	this.name = name;
>+	this.len = len;
>+	if (unlikely(!len))
>+		goto out;
>+
>+	p = (void *)name;
>+	hash = init_name_hash();
>+	while (len--) {
>+		c = *p++;
>+		if (unlikely(c == '/' || c == '\0'))
>+			goto out;
>+		hash = partial_name_hash(c, hash);
>+	}
>+	this.hash = end_name_hash(hash);
>+
>+	ndo = ndx->nd;
>+	if (ndo) {
>+		tmp_nd = *ndo;
>+		err = au_fake_intent(&tmp_nd, ndx->br->br_perm);
>+		dentry = ERR_PTR(err);
>+		if (unlikely(err))
>+			goto out_intent;
>+	} else
>+		memset(&tmp_nd, 0, sizeof(tmp_nd));
>+
>+	tmp_nd.path.dentry = parent;
>+	tmp_nd.path.mnt = ndx->nfsmnt;
>+	path_get(&tmp_nd.path);
>+	dentry = au_lkup_hash_dlgt(&this, parent, &tmp_nd, ndx->flags);
>+	if (0 && !IS_ERR(dentry))
>+		AuDbgDentry(dentry);
>+	if (!IS_ERR(dentry)) {
>+		/* why negative dentry for a new dir was unhashed? */
>+		if (unlikely(d_unhashed(dentry)))
>+			d_rehash(dentry);
>+		if (tmp_nd.intent.open.file
>+		    && tmp_nd.intent.open.file->f_dentry) {
>+			//AuDbgFile(tmp_nd.intent.open.file);
>+			ndx->nd_file = tmp_nd.intent.open.file;
>+			tmp_nd.intent.open.file = NULL;
>+			//au_br_get(ndx->br);
>+		}
>+	}
>+	path_put(&tmp_nd.path);
>+
>+ out_intent:
>+	if (tmp_nd.intent.open.file)
>+		put_filp(tmp_nd.intent.open.file);
>+ out:
>+	AuTraceErrPtr(dentry);
>+	return dentry;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/br_xfs.c linux-2.6.25.4-unionfs/fs/aufs/br_xfs.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/br_xfs.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/br_xfs.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,69 @@
>+/*
>+ * Copyright (C) 2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * special handling inode attributes on XFS branch in linux-2.6.24 and later
>+ *
>+ * $Id: br_xfs.c,v 1.2 2008/04/21 01:33:00 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+/* h_mnt can be NULL, is it safe? */
>+dev_t au_h_rdev(struct inode *h_inode, struct vfsmount *h_mnt,
>+		struct dentry *h_dentry)
>+{
>+	dev_t rdev;
>+	int err;
>+	struct kstat st;
>+
>+	LKTRTrace("hi%lu\n", h_inode->i_ino);
>+	if (h_dentry)
>+		LKTRTrace("%.*s\n", AuDLNPair(h_dentry));
>+
>+	rdev = h_inode->i_rdev;
>+	if (!rdev || !au_test_xfs(h_inode->i_sb))
>+		goto out;
>+
>+	rdev = 0;
>+	if (!h_dentry) {
>+		err = 0;
>+		h_dentry = d_find_alias(h_inode);
>+		if (unlikely(!h_dentry))
>+			goto failure;
>+		err = PTR_ERR(h_dentry);
>+		if (IS_ERR(h_dentry)) {
>+			h_dentry = NULL;
>+			goto failure;
>+		}
>+		LKTRTrace("%.*s\n", AuDLNPair(h_dentry));
>+	} else
>+		dget(h_dentry);
>+
>+	err = vfsub_getattr(h_mnt, h_dentry, &st, /*dlgt*/0);
>+	dput(h_dentry);
>+	if (!err) {
>+		rdev = st.rdev;
>+		goto out; /* success */
>+	}
>+
>+ failure:
>+	AuIOErr("failed rdev for XFS inode, hi%lu, %d\n", h_inode->i_ino, err);
>+ out:
>+	return rdev;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/cpup.c linux-2.6.25.4-unionfs/fs/aufs/cpup.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/cpup.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/cpup.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,1039 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * copy-up functions, see wbr_policy.c for copy-down
>+ *
>+ * $Id: cpup.c,v 1.5 2008/05/12 00:29:11 sfjro Exp $
>+ */
>+
>+#include <linux/fs_stack.h>
>+#include <linux/uaccess.h>
>+#include "aufs.h"
>+
>+/* violent cpup_attr_*() functions don't care inode lock */
>+void au_cpup_attr_timesizes(struct inode *inode)
>+{
>+	struct inode *h_inode;
>+
>+	LKTRTrace("i%lu\n", inode->i_ino);
>+	//IMustLock(inode);
>+	h_inode = au_h_iptr(inode, au_ibstart(inode));
>+	AuDebugOn(!h_inode);
>+	//IMustLock(!h_inode);
>+
>+	fsstack_copy_attr_times(inode, h_inode);
>+	//todo: this spin_lock conflicts the new unionfs patch in -mm tree
>+	spin_lock(&inode->i_lock);
>+	fsstack_copy_inode_size(inode, h_inode);
>+	spin_unlock(&inode->i_lock);
>+}
>+
>+void au_cpup_attr_nlink(struct inode *inode)
>+{
>+	struct inode *h_inode;
>+
>+	LKTRTrace("i%lu\n", inode->i_ino);
>+	//IMustLock(inode);
>+	AuDebugOn(!inode->i_mode);
>+
>+	h_inode = au_h_iptr(inode, au_ibstart(inode));
>+	inode->i_nlink = h_inode->i_nlink;
>+
>+	/*
>+	 * fewer nlink makes find(1) noisy, but larger nlink doesn't.
>+	 * it may includes whplink directory.
>+	 */
>+	if (unlikely(S_ISDIR(h_inode->i_mode))) {
>+		aufs_bindex_t bindex, bend;
>+		bend = au_ibend(inode);
>+		for (bindex = au_ibstart(inode) + 1; bindex <= bend; bindex++) {
>+			h_inode = au_h_iptr(inode, bindex);
>+			if (h_inode)
>+				au_add_nlink(inode, h_inode);
>+		}
>+	}
>+}
>+
>+void au_cpup_attr_changeable(struct inode *inode)
>+{
>+	struct inode *h_inode;
>+
>+	LKTRTrace("i%lu\n", inode->i_ino);
>+	//IMustLock(inode);
>+	h_inode = au_h_iptr(inode, au_ibstart(inode));
>+	AuDebugOn(!h_inode);
>+
>+	inode->i_mode = h_inode->i_mode;
>+	inode->i_uid = h_inode->i_uid;
>+	inode->i_gid = h_inode->i_gid;
>+	au_cpup_attr_timesizes(inode);
>+
>+	//??
>+	inode->i_flags = h_inode->i_flags;
>+}
>+
>+void au_cpup_igen(struct inode *inode, struct inode *h_inode)
>+{
>+	inode->i_generation = h_inode->i_generation;
>+	au_ii(inode)->ii_hsb1 = h_inode->i_sb;
>+}
>+
>+void au_cpup_attr_all(struct inode *inode)
>+{
>+	struct inode *h_inode;
>+
>+	LKTRTrace("i%lu\n", inode->i_ino);
>+	//IMustLock(inode);
>+	h_inode = au_h_iptr(inode, au_ibstart(inode));
>+	AuDebugOn(!h_inode);
>+
>+	au_cpup_attr_changeable(inode);
>+	if (inode->i_nlink > 0)
>+		au_cpup_attr_nlink(inode);
>+
>+	switch (inode->i_mode & S_IFMT) {
>+	case S_IFBLK:
>+	case S_IFCHR:
>+		inode->i_rdev = au_h_rdev(h_inode, /*h_mnt*/NULL,
>+					  /*h_dentry*/NULL);
>+	}
>+	inode->i_blkbits = h_inode->i_blkbits;
>+	au_cpup_igen(inode, h_inode);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* Note: dt_dentry and dt_hidden_dentry are not dget/dput-ed */
>+
>+/* keep the timestamps of the parent dir when cpup */
>+void au_dtime_store(struct au_dtime *dt, struct dentry *dentry,
>+		    struct dentry *h_dentry, struct au_hinode *hdir)
>+{
>+	struct inode *inode;
>+
>+	LKTRTrace("%.*s, hdir %d\n", AuDLNPair(dentry), !!hdir);
>+	AuDebugOn(!dentry || !h_dentry || !h_dentry->d_inode);
>+
>+	dt->dt_dentry = dentry;
>+	dt->dt_h_dentry = h_dentry;
>+	dt->dt_hdir = hdir;
>+	inode = h_dentry->d_inode;
>+	dt->dt_atime = inode->i_atime;
>+	dt->dt_mtime = inode->i_mtime;
>+	//smp_mb();
>+}
>+
>+void au_dtime_revert(struct au_dtime *dt)
>+{
>+	struct iattr attr;
>+	int err;
>+	struct au_hin_ignore ign;
>+	struct vfsub_args vargs;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dt->dt_dentry));
>+
>+	attr.ia_atime = dt->dt_atime;
>+	attr.ia_mtime = dt->dt_mtime;
>+	attr.ia_valid = ATTR_FORCE | ATTR_MTIME | ATTR_MTIME_SET
>+		| ATTR_ATIME | ATTR_ATIME_SET;
>+
>+	vfsub_args_init(&vargs, &ign,
>+			au_opt_test_dlgt(au_mntflags(dt->dt_dentry->d_sb)), 0);
>+	if (unlikely(dt->dt_hdir))
>+		vfsub_ign_hinode(&vargs, IN_ATTRIB, dt->dt_hdir);
>+	err = vfsub_notify_change(dt->dt_h_dentry, &attr, &vargs);
>+	if (unlikely(err))
>+		AuWarn("restoring timestamps failed(%d). ignored\n", err);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static noinline_for_stack int
>+cpup_iattr(struct dentry *h_dst, struct dentry *h_src, int dlgt)
>+{
>+	int err, sbits;
>+	struct iattr ia;
>+	struct inode *h_isrc, *h_idst;
>+	struct vfsub_args vargs;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(h_dst));
>+	h_idst = h_dst->d_inode;
>+	//IMustLock(h_idst);
>+	h_isrc = h_src->d_inode;
>+	//IMustLock(h_isrc);
>+
>+	ia.ia_valid = ATTR_FORCE | ATTR_MODE | ATTR_UID | ATTR_GID
>+		| ATTR_ATIME | ATTR_MTIME
>+		| ATTR_ATIME_SET | ATTR_MTIME_SET;
>+	ia.ia_mode = h_isrc->i_mode;
>+	ia.ia_uid = h_isrc->i_uid;
>+	ia.ia_gid = h_isrc->i_gid;
>+	ia.ia_atime = h_isrc->i_atime;
>+	ia.ia_mtime = h_isrc->i_mtime;
>+	sbits = !!(ia.ia_mode & (S_ISUID | S_ISGID));
>+
>+	vfsub_args_init(&vargs, NULL, dlgt, /*force_unlink*/0);
>+	err = vfsub_notify_change(h_dst, &ia, &vargs);
>+	//if (LktrCond) err = -1;
>+
>+	/* is this nfs only? */
>+	if (!err && sbits && au_test_nfs(h_dst->d_sb)) {
>+		ia.ia_valid = ATTR_FORCE | ATTR_MODE;
>+		ia.ia_mode = h_isrc->i_mode;
>+		err = vfsub_notify_change(h_dst, &ia, &vargs);
>+	}
>+
>+	if (!err)
>+		h_idst->i_flags = h_isrc->i_flags; //??
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * to support a sparse file which is opened with O_APPEND,
>+ * we need to close the file.
>+ */
>+static noinline_for_stack int
>+cpup_regular(struct dentry *dentry, aufs_bindex_t bdst, aufs_bindex_t bsrc,
>+	     loff_t len)
>+{
>+	int err, i;
>+	struct super_block *sb;
>+	struct inode *h_inode;
>+	enum { SRC, DST };
>+	struct {
>+		aufs_bindex_t bindex;
>+		unsigned int flags;
>+		struct dentry *dentry;
>+		struct file *file;
>+		void *label, *label_file;
>+	} *h, hidden[] = {
>+		{
>+			.bindex = bsrc,
>+			.flags = O_RDONLY | O_NOATIME | O_LARGEFILE,
>+			.file = NULL,
>+			.label = &&out,
>+			.label_file = &&out_src_file
>+		},
>+		{
>+			.bindex = bdst,
>+			.flags = O_WRONLY | O_NOATIME | O_LARGEFILE,
>+			.file = NULL,
>+			.label = &&out_src_file,
>+			.label_file = &&out_dst_file
>+		}
>+	};
>+
>+	LKTRTrace("dentry %.*s, bdst %d, bsrc %d, len %lld\n",
>+		  AuDLNPair(dentry), bdst, bsrc, len);
>+	AuDebugOn(bsrc <= bdst);
>+	AuDebugOn(!len);
>+	sb = dentry->d_sb;
>+	AuDebugOn(au_test_ro(sb, bdst, dentry->d_inode));
>+	/* bsrc branch can be ro/rw. */
>+
>+	h = hidden;
>+	for (i = 0; i < 2; i++, h++) {
>+		h->dentry = au_h_dptr(dentry, h->bindex);
>+		AuDebugOn(!h->dentry);
>+		h_inode = h->dentry->d_inode;
>+		AuDebugOn(!h_inode || !S_ISREG(h_inode->i_mode));
>+		h->file = au_h_open(dentry, h->bindex, h->flags, /*file*/NULL);
>+		//if (LktrCond)
>+		//{fput(h->file);au_sbr_put(sb, h->bindex);h->file=ERR_PTR(-1);}
>+		err = PTR_ERR(h->file);
>+		if (IS_ERR(h->file))
>+			goto *h->label;
>+		err = -EINVAL;
>+		if (unlikely(!h->file->f_op))
>+			goto *h->label_file;
>+	}
>+
>+	/* stop updating while we copyup */
>+	IMustLock(hidden[SRC].dentry->d_inode);
>+	err = au_copy_file(hidden[DST].file, hidden[SRC].file, len, sb);
>+
>+ out_dst_file:
>+	fput(hidden[DST].file);
>+	au_sbr_put(sb, hidden[DST].bindex);
>+ out_src_file:
>+	fput(hidden[SRC].file);
>+	au_sbr_put(sb, hidden[SRC].bindex);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static noinline_for_stack int
>+au_do_cpup_regular(struct dentry *dentry, aufs_bindex_t bdst,
>+		   aufs_bindex_t bsrc, loff_t len, struct inode *h_inode,
>+		   struct inode *h_dir, struct dentry *h_dst, int dlgt)
>+{
>+	int err, rerr;
>+	loff_t l;
>+	struct vfsub_args vargs;
>+
>+	AuTraceEnter();
>+
>+	err = 0;
>+	l = i_size_read(h_inode);
>+	if (len == -1 || l < len)
>+		len = l;
>+	if (len)
>+		err = cpup_regular(dentry, bdst, bsrc, len);
>+		//if (LktrCond) err = -1;
>+	if (!err)
>+		goto out; /* success */
>+
>+	vfsub_args_init(&vargs, NULL, dlgt, 0);
>+	rerr = vfsub_unlink(h_dir, h_dst, &vargs);
>+	if (rerr) {
>+		AuIOErr("failed unlinking cpup-ed %.*s(%d, %d)\n",
>+			AuDLNPair(h_dst), err, rerr);
>+		err = -EIO;
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static noinline_for_stack int
>+au_do_cpup_symlink(struct dentry *h_dst, struct dentry *h_src,
>+		   struct inode *h_dir, umode_t mode, int dlgt)
>+{
>+	int err, symlen;
>+	char *sym;
>+	mm_segment_t old_fs;
>+
>+	AuTraceEnter();
>+
>+	err = -ENOMEM;
>+	sym = __getname();
>+	//if (LktrCond) {__putname(sym); sym = NULL;}
>+	if (unlikely(!sym))
>+		goto out;
>+
>+	old_fs = get_fs();
>+	set_fs(KERNEL_DS);
>+	symlen = h_src->d_inode->i_op->readlink(h_src, (char __user *)sym,
>+						PATH_MAX);
>+	err = symlen;
>+	//if (LktrCond) err = symlen = -1;
>+	set_fs(old_fs);
>+
>+	if (symlen > 0) {
>+		sym[symlen] = 0;
>+		err = vfsub_symlink(h_dir, h_dst, sym, mode, dlgt);
>+		//if (LktrCond)
>+		//{vfs_unlink(h_dir, h_dst); err = -1;}
>+	}
>+	__putname(sym);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* return with hidden dst inode is locked */
>+static noinline_for_stack int
>+cpup_entry(struct dentry *dentry, aufs_bindex_t bdst, aufs_bindex_t bsrc,
>+	   loff_t len, unsigned int flags, int dlgt)
>+{
>+	int err, isdir, hinotify;
>+	struct dentry *h_src, *h_dst, *h_parent, *parent;
>+	struct inode *h_inode, *h_dir;
>+	struct au_dtime dt;
>+	umode_t mode;
>+	struct super_block *sb;
>+	struct au_hinode *hgdir;
>+	const int do_dt = au_ftest_cpup(flags, DTIME);
>+	unsigned int mnt_flags;
>+
>+	LKTRTrace("%.*s, i%lu, bdst %d, bsrc %d, len %Ld, dtime %u\n",
>+		  AuDLNPair(dentry), dentry->d_inode->i_ino, bdst, bsrc, len,
>+		  do_dt);
>+	sb = dentry->d_sb;
>+	AuDebugOn(bdst >= bsrc || au_test_ro(sb, bdst, NULL));
>+	/* bsrc branch can be ro/rw. */
>+
>+	h_src = au_h_dptr(dentry, bsrc);
>+	AuDebugOn(!h_src);
>+	h_inode = h_src->d_inode;
>+	AuDebugOn(!h_inode);
>+
>+	/* stop referencing while we are creating */
>+	parent = dget_parent(dentry);
>+	h_dst = au_h_dptr(dentry, bdst);
>+	AuDebugOn(h_dst && h_dst->d_inode);
>+	h_parent = h_dst->d_parent; /* dir inode is locked */
>+	h_dir = h_parent->d_inode;
>+	IMustLock(h_dir);
>+
>+	mnt_flags = au_mntflags(sb);
>+	hinotify = !!au_opt_test(mnt_flags, UDBA_INOTIFY);
>+	if (do_dt) {
>+		hgdir = NULL;
>+		if (unlikely(hinotify && !IS_ROOT(parent))) {
>+			struct dentry *gparent;
>+			gparent = dget_parent(parent);
>+			hgdir = au_hi(gparent->d_inode, bdst);
>+			dput(gparent);
>+		}
>+		au_dtime_store(&dt, parent, h_parent, hgdir);
>+	}
>+
>+	isdir = 0;
>+	mode = h_inode->i_mode;
>+	switch (mode & S_IFMT) {
>+	case S_IFREG:
>+		/* stop updating while we are referencing */
>+		IMustLock(h_inode);
>+		err = au_h_create(h_dir, h_dst, mode | S_IWUSR, dlgt, NULL,
>+				  au_nfsmnt(sb, bdst));
>+		//if (LktrCond) {vfs_unlink(h_dir, h_dst); err = -1;}
>+		if (!err)
>+			err = au_do_cpup_regular(dentry, bdst, bsrc, len,
>+						 h_inode, h_dir, h_dst, dlgt);
>+		break;
>+	case S_IFDIR:
>+		isdir = 1;
>+		err = vfsub_mkdir(h_dir, h_dst, mode, dlgt);
>+		//if (LktrCond) {vfs_rmdir(h_dir, h_dst); err = -1;}
>+		if (!err) {
>+			/* setattr case: dir is not locked */
>+			if (0 && au_ibstart(parent->d_inode) == bdst)
>+				au_cpup_attr_nlink(parent->d_inode);
>+			au_cpup_attr_nlink(dentry->d_inode);
>+		}
>+		break;
>+	case S_IFLNK:
>+		err = au_do_cpup_symlink(h_dst, h_src, h_dir, mode, dlgt);
>+		break;
>+	case S_IFCHR:
>+	case S_IFBLK:
>+		AuDebugOn(!capable(CAP_MKNOD));
>+		/*FALLTHROUGH*/
>+	case S_IFIFO:
>+	case S_IFSOCK:
>+		err = vfsub_mknod(h_dir, h_dst, mode,
>+				  au_h_rdev(h_inode, /*h_mnt*/NULL, h_src),
>+				  dlgt);
>+		//if (LktrCond) {vfs_unlink(h_dir, h_dst); err = -1;}
>+		break;
>+	default:
>+		AuIOErr("Unknown inode type 0%o\n", mode);
>+		err = -EIO;
>+	}
>+
>+	//todo: should it be always?
>+	if (unlikely(hinotify
>+		     && !isdir
>+		     && au_opt_test(mnt_flags, XINO)
>+		     && h_inode->i_nlink == 1
>+		     && bdst < bsrc))
>+		au_xino_write0(sb, bsrc, h_inode->i_ino, /*ino*/0);
>+		/* ignore this error */
>+
>+	if (do_dt)
>+		au_dtime_revert(&dt);
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * copyup the @dentry from @bsrc to @bdst.
>+ * the caller must set the both of hidden dentries.
>+ * @len is for truncating when it is -1 copyup the entire file.
>+ */
>+int au_cpup_single(struct dentry *dentry, aufs_bindex_t bdst,
>+		   aufs_bindex_t bsrc, loff_t len, unsigned int flags)
>+{
>+	int err, rerr, isdir, dlgt, plink;
>+	struct dentry *h_src, *h_dst, *parent, *h_parent;
>+	struct inode *dst_inode, *h_dir, *inode;
>+	struct super_block *sb;
>+	aufs_bindex_t old_ibstart;
>+	struct au_dtime dt;
>+	struct vfsub_args vargs;
>+	struct au_hinode *hgdir;
>+	unsigned int mnt_flags;
>+
>+	LKTRTrace("%.*s, i%lu, bdst %d, bsrc %d, len %Ld, flags 0x%x\n",
>+		  AuDLNPair(dentry), dentry->d_inode->i_ino, bdst, bsrc, len,
>+		  flags);
>+	sb = dentry->d_sb;
>+	AuDebugOn(bsrc <= bdst);
>+	h_dst = au_h_dptr(dentry, bdst);
>+	AuDebugOn(!h_dst || h_dst->d_inode);
>+	h_parent = h_dst->d_parent; /* dir inode is locked */
>+	h_dir = h_parent->d_inode;
>+	IMustLock(h_dir);
>+	h_src = au_h_dptr(dentry, bsrc);
>+	AuDebugOn(!h_src || !h_src->d_inode);
>+	inode = dentry->d_inode;
>+	IiMustWriteLock(inode);
>+	parent = dget_parent(dentry);
>+
>+	mnt_flags = au_mntflags(sb);
>+	dlgt = !!au_opt_test_dlgt(mnt_flags);
>+	plink = !!au_opt_test(mnt_flags, PLINK);
>+	dst_inode = au_h_iptr(inode, bdst);
>+	if (unlikely(dst_inode)) {
>+		if (unlikely(!plink)) {
>+			err = -EIO;
>+			AuIOErr("i%lu exists on a upper branch "
>+				"but plink is disabled\n", inode->i_ino);
>+			goto out;
>+		}
>+
>+		if (dst_inode->i_nlink) {
>+			h_src = au_plink_lkup(sb, bdst, inode);
>+			err = PTR_ERR(h_src);
>+			if (IS_ERR(h_src))
>+				goto out;
>+			AuDebugOn(!h_src->d_inode);
>+			err = vfsub_link(h_src, h_dir, h_dst, dlgt);
>+			dput(h_src);
>+			goto out;
>+		} else
>+			//todo: cpup_wh_file
>+			/* udba work */
>+			au_update_brange(inode, 1);
>+	}
>+
>+	old_ibstart = au_ibstart(inode);
>+	err = cpup_entry(dentry, bdst, bsrc, len, flags, dlgt);
>+	if (unlikely(err))
>+		goto out;
>+	dst_inode = h_dst->d_inode;
>+	mutex_lock_nested(&dst_inode->i_mutex, AuLsc_I_CHILD2);
>+
>+	//todo: test dlgt
>+	err = cpup_iattr(h_dst, h_src, dlgt);
>+	//if (LktrCond) err = -1;
>+	isdir = S_ISDIR(dst_inode->i_mode);
>+	if (!err) {
>+		if (bdst < old_ibstart)
>+			au_set_ibstart(inode, bdst);
>+		au_set_h_iptr(inode, bdst, igrab(dst_inode),
>+			      au_hi_flags(inode, isdir));
>+		mutex_unlock(&dst_inode->i_mutex);
>+		if (!isdir
>+		    && h_src->d_inode->i_nlink > 1
>+		    && plink)
>+			au_plink_append(sb, inode, h_dst, bdst);
>+		goto out; /* success */
>+	}
>+
>+	/* revert */
>+	mutex_unlock(&dst_inode->i_mutex);
>+	hgdir = NULL;
>+	if (unlikely(au_opt_test(mnt_flags, UDBA_INOTIFY)
>+		     && !IS_ROOT(parent))) {
>+		struct dentry *gparent;
>+		gparent = dget_parent(parent);
>+		hgdir = au_hi(gparent->d_inode, bdst);
>+		dput(gparent);
>+	}
>+	au_dtime_store(&dt, parent, h_parent, hgdir);
>+	vfsub_args_init(&vargs, NULL, dlgt, 0);
>+	if (!isdir)
>+		rerr = vfsub_unlink(h_dir, h_dst, &vargs);
>+	else
>+		rerr = vfsub_rmdir(h_dir, h_dst, &vargs);
>+	//rerr = -1;
>+	au_dtime_revert(&dt);
>+	if (rerr) {
>+		AuIOErr("failed removing broken entry(%d, %d)\n", err, rerr);
>+		err = -EIO;
>+	}
>+
>+ out:
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+struct au_cpup_single_args {
>+	int *errp;
>+	struct dentry *dentry;
>+	aufs_bindex_t bdst, bsrc;
>+	loff_t len;
>+	unsigned int flags;
>+};
>+
>+static void au_call_cpup_single(void *args)
>+{
>+	struct au_cpup_single_args *a = args;
>+	*a->errp = au_cpup_single(a->dentry, a->bdst, a->bsrc, a->len,
>+				  a->flags);
>+}
>+
>+int au_sio_cpup_single(struct dentry *dentry, aufs_bindex_t bdst,
>+		       aufs_bindex_t bsrc, loff_t len, unsigned int flags)
>+{
>+	int err, wkq_err;
>+	struct dentry *h_dentry;
>+	umode_t mode;
>+
>+	LKTRTrace("%.*s, i%lu, bdst %d, bsrc %d, len %Ld, flags 0x%x\n",
>+		  AuDLNPair(dentry), dentry->d_inode->i_ino, bdst, bsrc, len,
>+		  flags);
>+
>+	h_dentry = au_h_dptr(dentry, bsrc);
>+	mode = h_dentry->d_inode->i_mode & S_IFMT;
>+	if ((mode != S_IFCHR && mode != S_IFBLK)
>+	    || capable(CAP_MKNOD))
>+		err = au_cpup_single(dentry, bdst, bsrc, len, flags);
>+	else {
>+		struct au_cpup_single_args args = {
>+			.errp		= &err,
>+			.dentry		= dentry,
>+			.bdst		= bdst,
>+			.bsrc		= bsrc,
>+			.len		= len,
>+			.flags		= flags
>+		};
>+		wkq_err = au_wkq_wait(au_call_cpup_single, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * copyup the @dentry from the first active hidden branch to @bdst,
>+ * using au_cpup_single().
>+ */
>+int au_cpup_simple(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
>+		   unsigned int flags)
>+{
>+	int err;
>+	struct inode *inode;
>+	aufs_bindex_t bsrc, bend;
>+
>+	LKTRTrace("%.*s, bdst %d, len %Ld, flags 0x%x\n",
>+		  AuDLNPair(dentry), bdst, len, flags);
>+	inode = dentry->d_inode;
>+	AuDebugOn(!S_ISDIR(inode->i_mode) && au_dbstart(dentry) < bdst);
>+
>+	bend = au_dbend(dentry);
>+	for (bsrc = bdst + 1; bsrc <= bend; bsrc++)
>+		if (au_h_dptr(dentry, bsrc))
>+			break;
>+	AuDebugOn(!au_h_dptr(dentry, bsrc));
>+
>+	err = au_lkup_neg(dentry, bdst);
>+	//err = -1;
>+	if (!err) {
>+		err = au_cpup_single(dentry, bdst, bsrc, len, flags);
>+		if (!err)
>+			return 0; /* success */
>+
>+		/* revert */
>+		au_set_h_dptr(dentry, bdst, NULL);
>+		au_set_dbstart(dentry, bsrc);
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+struct au_cpup_simple_args {
>+	int *errp;
>+	struct dentry *dentry;
>+	aufs_bindex_t bdst;
>+	loff_t len;
>+	unsigned int flags;
>+};
>+
>+static void au_call_cpup_simple(void *args)
>+{
>+	struct au_cpup_simple_args *a = args;
>+	*a->errp = au_cpup_simple(a->dentry, a->bdst, a->len, a->flags);
>+}
>+
>+int au_sio_cpup_simple(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
>+		       unsigned int flags)
>+{
>+	int err, do_sio, dlgt, wkq_err;
>+	struct dentry *parent;
>+	struct inode *h_dir, *dir;
>+
>+	LKTRTrace("%.*s, b%d, len %Ld, flags 0x%x\n",
>+		  AuDLNPair(dentry), bdst, len, flags);
>+
>+	parent = dget_parent(dentry);
>+	dir = parent->d_inode;
>+	h_dir = au_h_iptr(dir, bdst);
>+	dlgt = !!au_opt_test_dlgt(au_mntflags(dir->i_sb));
>+	do_sio = au_test_h_perm_sio(h_dir, MAY_EXEC | MAY_WRITE, dlgt);
>+	if (!do_sio) {
>+		/*
>+		 * testing CAP_MKNOD is for generic fs,
>+		 * but CAP_FSETID is for xfs only, currently.
>+		 */
>+		umode_t mode = dentry->d_inode->i_mode;
>+		do_sio = (((mode & (S_IFCHR | S_IFBLK))
>+			   && !capable(CAP_MKNOD))
>+			  || ((mode & (S_ISUID | S_ISGID))
>+			      && !capable(CAP_FSETID)));
>+	}
>+	if (!do_sio)
>+		err = au_cpup_simple(dentry, bdst, len, flags);
>+	else {
>+		struct au_cpup_simple_args args = {
>+			.errp		= &err,
>+			.dentry		= dentry,
>+			.bdst		= bdst,
>+			.len		= len,
>+			.flags		= flags
>+		};
>+		wkq_err = au_wkq_wait(au_call_cpup_simple, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static noinline_for_stack int
>+au_do_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst,
>+	      struct dentry *wh_dentry, struct file *file, loff_t len)
>+{
>+	int err;
>+	struct au_dinfo *dinfo;
>+	aufs_bindex_t bstart;
>+	struct dentry *h_d_bdst, *h_d_bstart;
>+
>+	AuTraceEnter();
>+
>+	dinfo = au_di(dentry);
>+	bstart = dinfo->di_bstart;
>+	h_d_bdst = dinfo->di_hdentry[0 + bdst].hd_dentry;
>+	dinfo->di_bstart = bdst;
>+	dinfo->di_hdentry[0 + bdst].hd_dentry = wh_dentry;
>+	h_d_bstart = dinfo->di_hdentry[0 + bstart].hd_dentry;
>+	if (file)
>+		dinfo->di_hdentry[0 + bstart].hd_dentry
>+			= au_h_fptr(file, au_fbstart(file))->f_dentry;
>+	err = au_cpup_single(dentry, bdst, bstart, len, !AuCpup_DTIME);
>+	//if (LktrCond) err = -1;
>+	if (!err && file) {
>+		err = au_reopen_nondir(file);
>+		//err = -1;
>+		dinfo->di_hdentry[0 + bstart].hd_dentry = h_d_bstart;
>+	}
>+	dinfo->di_hdentry[0 + bdst].hd_dentry = h_d_bdst;
>+	dinfo->di_bstart = bstart;
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * copyup the deleted file for writing.
>+ */
>+int au_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
>+	       struct file *file)
>+{
>+	int err, dlgt;
>+	struct dentry *parent, *h_parent, *wh_dentry;
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+	struct au_dtime dt;
>+	struct vfsub_args vargs;
>+	struct au_hinode *hgdir;
>+	struct au_ndx ndx = {
>+		.nd	= NULL,
>+		.flags	= 0,
>+		//.br	= NULL
>+	};
>+
>+	LKTRTrace("%.*s, bdst %d, len %Lu\n", AuDLNPair(dentry), bdst, len);
>+	AuDebugOn(S_ISDIR(dentry->d_inode->i_mode)
>+		  || (file && !(file->f_mode & FMODE_WRITE)));
>+	DiMustWriteLock(dentry);
>+
>+	parent = dget_parent(dentry);
>+	IiMustAnyLock(parent->d_inode);
>+	h_parent = au_h_dptr(parent, bdst);
>+	AuDebugOn(!h_parent);
>+
>+	sb = parent->d_sb;
>+	mnt_flags = au_mntflags(sb);
>+	dlgt = 0;
>+	ndx.nfsmnt = au_nfsmnt(sb, bdst);
>+	if (unlikely(au_opt_test_dlgt(mnt_flags))) {
>+		dlgt = 1;
>+		au_fset_ndx(ndx.flags, DLGT);
>+	}
>+	wh_dentry = au_whtmp_lkup(h_parent, &dentry->d_name, &ndx);
>+	//if (LktrCond) {dput(wh_dentry); wh_dentry = ERR_PTR(-1);}
>+	err = PTR_ERR(wh_dentry);
>+	if (IS_ERR(wh_dentry))
>+		goto out;
>+
>+	hgdir = NULL;
>+	if (unlikely(au_opt_test(mnt_flags, UDBA_INOTIFY)
>+		     && !IS_ROOT(parent))) {
>+		struct dentry *gparent;
>+		gparent = dget_parent(parent);
>+		hgdir = au_hi(gparent->d_inode, bdst);
>+		dput(gparent);
>+	}
>+	au_dtime_store(&dt, parent, h_parent, hgdir);
>+	err = au_do_cpup_wh(dentry, bdst, wh_dentry, file, len);
>+	if (unlikely(err))
>+		goto out_wh;
>+
>+	AuDebugOn(!d_unhashed(dentry));
>+	/* dget first to force sillyrename on nfs */
>+	dget(wh_dentry);
>+	vfsub_args_init(&vargs, NULL, dlgt, 0);
>+	err = vfsub_unlink(h_parent->d_inode, wh_dentry, &vargs);
>+	//if (LktrCond) err = -1;
>+	if (unlikely(err)) {
>+		AuIOErr("failed remove copied-up tmp file %.*s(%d)\n",
>+			AuDLNPair(wh_dentry), err);
>+		err = -EIO;
>+	}
>+	au_dtime_revert(&dt);
>+	au_set_hi_wh(dentry->d_inode, bdst, wh_dentry);
>+
>+ out_wh:
>+	dput(wh_dentry);
>+ out:
>+	dput(parent);
>+	AuTraceErr(err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+struct au_cpup_wh_args {
>+	int *errp;
>+	struct dentry *dentry;
>+	aufs_bindex_t bdst;
>+	loff_t len;
>+	struct file *file;
>+};
>+
>+static void au_call_cpup_wh(void *args)
>+{
>+	struct au_cpup_wh_args *a = args;
>+	*a->errp = au_cpup_wh(a->dentry, a->bdst, a->len, a->file);
>+}
>+
>+int au_sio_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
>+		   struct file *file)
>+{
>+	int err, wkq_err;
>+	struct dentry *parent;
>+	struct inode *dir, *h_dir;
>+
>+	AuTraceEnter();
>+	parent = dget_parent(dentry);
>+	dir = parent->d_inode;
>+	IiMustAnyLock(dir);
>+	h_dir = au_h_iptr(dir, bdst);
>+
>+	if (!au_test_h_perm_sio
>+	    (h_dir, MAY_EXEC | MAY_WRITE,
>+	     au_opt_test_dlgt(au_mntflags(dentry->d_sb))))
>+		err = au_cpup_wh(dentry, bdst, len, file);
>+	else {
>+		struct au_cpup_wh_args args = {
>+			.errp	= &err,
>+			.dentry	= dentry,
>+			.bdst	= bdst,
>+			.len	= len,
>+			.file	= file
>+		};
>+		wkq_err = au_wkq_wait(au_call_cpup_wh, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+	dput(parent);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * generic routine for both of copy-up and copy-down.
>+ * Although I've tried building a path by dcsub, I gave up this approach.
>+ * Since the ancestor directory may be moved/renamed during copy.
>+ */
>+/* cf. revalidate function in file.c */
>+int au_cp_dirs(struct dentry *dentry, aufs_bindex_t bdst, struct dentry *locked,
>+	       int (*cp)(struct dentry *dentry, aufs_bindex_t bdst,
>+			 struct dentry *h_parent, void *arg),
>+	       void *arg)
>+{
>+	int err, hinotify;
>+	struct super_block *sb;
>+	struct dentry *d, *parent, *h_parent, *gparent, *real_parent;
>+
>+	LKTRTrace("%.*s, b%d, parent i%lu, locked %p\n",
>+		  AuDLNPair(dentry), bdst, parent_ino(dentry), locked);
>+	sb = dentry->d_sb;
>+	AuDebugOn(au_test_ro(sb, bdst, NULL));
>+	err = 0;
>+	parent = dget_parent(dentry);
>+	IiMustWriteLock(parent->d_inode);
>+	if (unlikely(IS_ROOT(parent)))
>+		goto out;
>+	if (locked) {
>+		DiMustAnyLock(locked);
>+		IiMustAnyLock(locked->d_inode);
>+	}
>+
>+	/* slow loop, keep it simple and stupid */
>+	real_parent = parent;
>+	hinotify = !!au_opt_test(au_mntflags(sb), UDBA_INOTIFY);
>+	while (1) {
>+		dput(parent);
>+		parent = dget_parent(dentry);
>+		h_parent = au_h_dptr(parent, bdst);
>+		if (h_parent)
>+			goto out; /* success */
>+
>+		/* find top dir which is needed to cpup */
>+		do {
>+			d = parent;
>+			dput(parent);
>+			parent = dget_parent(d);
>+			if (parent != locked) {
>+				di_read_lock_parent3(parent, !AuLock_IR);
>+				h_parent = au_h_dptr(parent, bdst);
>+				di_read_unlock(parent, !AuLock_IR);
>+			} else
>+				h_parent = au_h_dptr(parent, bdst);
>+		} while (!h_parent);
>+
>+		if (d != real_parent)
>+			di_write_lock_child3(d);
>+
>+		/* somebody else might create while we were sleeping */
>+		if (!au_h_dptr(d, bdst) || !au_h_dptr(d, bdst)->d_inode) {
>+			struct inode *h_dir = h_parent->d_inode,
>+				*dir = parent->d_inode;
>+
>+			if (au_h_dptr(d, bdst))
>+				au_update_dbstart(d);
>+			//AuDebugOn(au_dbstart(d) <= bdst);
>+			if (parent != locked)
>+				di_read_lock_parent3(parent, AuLock_IR);
>+			gparent = NULL;
>+			if (unlikely(hinotify && !IS_ROOT(parent))) {
>+				gparent = dget_parent(parent);
>+				if (gparent != locked)
>+					ii_read_lock_parent4(gparent->d_inode);
>+				else {
>+					dput(gparent);
>+					gparent = NULL;
>+				}
>+			}
>+			au_hdir_lock(h_dir, dir, bdst);
>+			err = cp(d, bdst, h_parent, arg);
>+			//if (LktrCond) err = -1;
>+			au_hdir_unlock(h_dir, dir, bdst);
>+			if (unlikely(gparent)) {
>+				ii_read_unlock(gparent->d_inode);
>+				dput(gparent);
>+			}
>+			if (parent != locked)
>+				di_read_unlock(parent, AuLock_IR);
>+		}
>+
>+		if (d != real_parent)
>+			di_write_unlock(d);
>+		if (unlikely(err))
>+			break;
>+	}
>+
>+ out:
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int au_cpup_dir(struct dentry *dentry, aufs_bindex_t bdst,
>+		       struct dentry *h_parent, void *arg)
>+{
>+	int err;
>+
>+	err = au_sio_cpup_simple(dentry, bdst, -1, AuCpup_DTIME);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst,
>+		 struct dentry *locked)
>+{
>+	int err;
>+
>+	err = au_cp_dirs(dentry, bdst, locked, au_cpup_dir, NULL);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_test_and_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst,
>+			  struct dentry *locked)
>+{
>+	int err;
>+	struct dentry *parent;
>+	struct inode *dir;
>+
>+	parent = dget_parent(dentry);
>+	dir = parent->d_inode;
>+	LKTRTrace("%.*s, b%d, parent i%lu, locked %p\n",
>+		  AuDLNPair(dentry), bdst, dir->i_ino, locked);
>+	DiMustReadLock(parent);
>+	IiMustReadLock(dir);
>+
>+	err = 0;
>+	if (au_h_iptr(dir, bdst))
>+		goto out;
>+
>+	di_read_unlock(parent, AuLock_IR);
>+	di_write_lock_parent2(parent);
>+	/* someone else might change our inode while we were sleeping */
>+	if (unlikely(!au_h_iptr(dir, bdst)))
>+		err = au_cpup_dirs(dentry, bdst, locked);
>+	di_downgrade_lock(parent, AuLock_IR);
>+
>+ out:
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/cpup.h linux-2.6.25.4-unionfs/fs/aufs/cpup.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/cpup.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/cpup.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,82 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * copy-up/down functions
>+ *
>+ * $Id: cpup.h,v 1.2 2008/04/21 01:33:43 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_CPUP_H__
>+#define __AUFS_CPUP_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/aufs_type.h>
>+
>+void au_cpup_attr_timesizes(struct inode *inode);
>+void au_cpup_attr_nlink(struct inode *inode);
>+void au_cpup_attr_changeable(struct inode *inode);
>+void au_cpup_igen(struct inode *inode, struct inode *h_inode);
>+void au_cpup_attr_all(struct inode *inode);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* cpup flags */
>+#define AuCpup_DTIME	1	/* do dtime_store/revert */
>+#define au_ftest_cpup(flags, name)	((flags) & AuCpup_##name)
>+#define au_fset_cpup(flags, name)	{ (flags) |= AuCpup_##name; }
>+#define au_fclr_cpup(flags, name)	{ (flags) &= ~AuCpup_##name; }
>+
>+int au_cpup_single(struct dentry *dentry, aufs_bindex_t bdst,
>+		   aufs_bindex_t bsrc, loff_t len, unsigned int flags);
>+int au_sio_cpup_single(struct dentry *dentry, aufs_bindex_t bdst,
>+		       aufs_bindex_t bsrc, loff_t len, unsigned int flags);
>+int au_cpup_simple(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
>+		   unsigned int flags);
>+int au_sio_cpup_simple(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
>+		       unsigned int flags);
>+int au_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
>+	       struct file *file);
>+int au_sio_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
>+		   struct file *file);
>+
>+int au_cp_dirs(struct dentry *dentry, aufs_bindex_t bdst, struct dentry *locked,
>+	       int (*cp)(struct dentry *dentry, aufs_bindex_t bdst,
>+			 struct dentry *h_parent, void *arg),
>+	       void *arg);
>+int au_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst,
>+		 struct dentry *locked);
>+int au_test_and_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst,
>+			  struct dentry *locked);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* keep timestamps when copyup */
>+struct au_dtime {
>+	struct dentry *dt_dentry, *dt_h_dentry;
>+	struct au_hinode *dt_hdir;
>+	struct timespec dt_atime, dt_mtime;
>+};
>+void au_dtime_store(struct au_dtime *dt, struct dentry *dentry,
>+		    struct dentry *h_dentry, struct au_hinode *hdir);
>+void au_dtime_revert(struct au_dtime *dt);
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_CPUP_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/dcsub.c linux-2.6.25.4-unionfs/fs/aufs/dcsub.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/dcsub.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/dcsub.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,233 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * sub-routines for dentry cache
>+ *
>+ * $Id: dcsub.c,v 1.3 2008/05/19 01:47:37 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+static void au_dpage_free(struct au_dpage *dpage)
>+{
>+	int i;
>+
>+	AuTraceEnter();
>+	AuDebugOn(!dpage);
>+
>+	for (i = 0; i < dpage->ndentry; i++)
>+		dput(dpage->dentries[i]);
>+	free_page((unsigned long)dpage->dentries);
>+}
>+
>+int au_dpages_init(struct au_dcsub_pages *dpages, gfp_t gfp)
>+{
>+	int err;
>+	void *p;
>+
>+	AuTraceEnter();
>+
>+	err = -ENOMEM;
>+	dpages->dpages = kmalloc(sizeof(*dpages->dpages), gfp);
>+	if (unlikely(!dpages->dpages))
>+		goto out;
>+	p = (void *)__get_free_page(gfp);
>+	if (unlikely(!p))
>+		goto out_dpages;
>+	dpages->dpages[0].ndentry = 0;
>+	dpages->dpages[0].dentries = p;
>+	dpages->ndpage = 1;
>+	return 0; /* success */
>+
>+ out_dpages:
>+	kfree(dpages->dpages);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+void au_dpages_free(struct au_dcsub_pages *dpages)
>+{
>+	int i;
>+
>+	AuTraceEnter();
>+
>+	for (i = 0; i < dpages->ndpage; i++)
>+		au_dpage_free(dpages->dpages + i);
>+	kfree(dpages->dpages);
>+}
>+
>+static int au_dpages_append(struct au_dcsub_pages *dpages,
>+			    struct dentry *dentry, gfp_t gfp)
>+{
>+	int err, sz;
>+	struct au_dpage *dpage;
>+	void *p;
>+
>+	//AuTraceEnter();
>+
>+	dpage = dpages->dpages + dpages->ndpage - 1;
>+	AuDebugOn(!dpage);
>+	sz = PAGE_SIZE / sizeof(dentry);
>+	if (unlikely(dpage->ndentry >= sz)) {
>+		LKTRLabel(new dpage);
>+		err = -ENOMEM;
>+		sz = dpages->ndpage * sizeof(*dpages->dpages);
>+		p = au_kzrealloc(dpages->dpages, sz,
>+				 sz + sizeof(*dpages->dpages), gfp);
>+		if (unlikely(!p))
>+			goto out;
>+		dpages->dpages = p;
>+		dpage = dpages->dpages + dpages->ndpage;
>+		p = (void *)__get_free_page(gfp);
>+		if (unlikely(!p))
>+			goto out;
>+		dpage->ndentry = 0;
>+		dpage->dentries = p;
>+		dpages->ndpage++;
>+	}
>+
>+	dpage->dentries[dpage->ndentry++] = dget(dentry);
>+	return 0; /* success */
>+
>+ out:
>+	//AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_dcsub_pages(struct au_dcsub_pages *dpages, struct dentry *root,
>+		   au_dpages_test test, void *arg)
>+{
>+	int err;
>+	struct dentry *this_parent = root;
>+	struct list_head *next;
>+	struct super_block *sb = root->d_sb;
>+
>+	AuTraceEnter();
>+
>+	err = 0;
>+	spin_lock(&dcache_lock);
>+ repeat:
>+	next = this_parent->d_subdirs.next;
>+ resume:
>+	if (this_parent->d_sb == sb
>+	    && !IS_ROOT(this_parent)
>+	    && atomic_read(&this_parent->d_count)
>+	    && this_parent->d_inode
>+	    && (!test || test(this_parent, arg))) {
>+		err = au_dpages_append(dpages, this_parent, GFP_ATOMIC);
>+		if (unlikely(err))
>+			goto out;
>+	}
>+
>+	while (next != &this_parent->d_subdirs) {
>+		struct list_head *tmp = next;
>+		struct dentry *dentry = list_entry(tmp, struct dentry,
>+						   d_u.d_child);
>+		next = tmp->next;
>+		if (unlikely(/*d_unhashed(dentry) || */!dentry->d_inode))
>+			continue;
>+		if (!list_empty(&dentry->d_subdirs)) {
>+			this_parent = dentry;
>+			goto repeat;
>+		}
>+		if (dentry->d_sb == sb
>+		    && atomic_read(&dentry->d_count)
>+		    && (!test || test(dentry, arg))) {
>+			err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
>+			if (unlikely(err))
>+				goto out;
>+		}
>+	}
>+
>+	if (this_parent != root) {
>+		next = this_parent->d_u.d_child.next;
>+		this_parent = this_parent->d_parent; /* dcache_lock is locked */
>+		goto resume;
>+	}
>+ out:
>+	spin_unlock(&dcache_lock);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_dcsub_pages_rev(struct au_dcsub_pages *dpages, struct dentry *dentry,
>+		       int do_include, au_dpages_test test, void *arg)
>+{
>+	int err;
>+
>+	AuTraceEnter();
>+
>+	err = 0;
>+	spin_lock(&dcache_lock);
>+	if (do_include && (!test || test(dentry, arg))) {
>+		err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
>+		if (unlikely(err))
>+			goto out;
>+	}
>+	while (!IS_ROOT(dentry)) {
>+		dentry = dentry->d_parent; /* dcache_lock is locked */
>+		if (!test || test(dentry, arg)) {
>+			err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
>+			if (unlikely(err))
>+				break;
>+		}
>+	}
>+
>+ out:
>+	spin_unlock(&dcache_lock);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_test_subdir(struct dentry *d1, struct dentry *d2)
>+{
>+	int err;
>+	int i, j;
>+	struct au_dcsub_pages dpages;
>+	struct au_dpage *dpage;
>+	struct dentry **dentries;
>+
>+	LKTRTrace("%.*s, %.*s\n", AuDLNPair(d1), AuDLNPair(d2));
>+
>+	err = au_dpages_init(&dpages, GFP_TEMPORARY);
>+	if (unlikely(err))
>+		goto out;
>+	err = au_dcsub_pages_rev(&dpages, d1, /*do_include*/1, NULL, NULL);
>+	if (unlikely(err))
>+		goto out_dpages;
>+
>+	for (i = dpages.ndpage - 1; !err && i >= 0; i--) {
>+		dpage = dpages.dpages + i;
>+		dentries = dpage->dentries;
>+		for (j = dpage->ndentry - 1; !err && j >= 0; j--) {
>+			struct dentry *d;
>+			d = dentries[j];
>+			//AuDbg("d %.*s\n", AuDLNPair(d));
>+			err = (d == d2);
>+		}
>+	}
>+
>+ out_dpages:
>+	au_dpages_free(&dpages);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/dcsub.h linux-2.6.25.4-unionfs/fs/aufs/dcsub.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/dcsub.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/dcsub.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,54 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * sub-routines for dentry cache
>+ *
>+ * $Id: dcsub.h,v 1.1 2008/04/18 12:18:29 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_DCSUB_H__
>+#define __AUFS_DCSUB_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/dcache.h>
>+
>+struct au_dpage {
>+	int ndentry;
>+	struct dentry **dentries;
>+};
>+
>+struct au_dcsub_pages {
>+	int ndpage;
>+	struct au_dpage *dpages;
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int au_dpages_init(struct au_dcsub_pages *dpages, gfp_t gfp);
>+void au_dpages_free(struct au_dcsub_pages *dpages);
>+typedef int (*au_dpages_test)(struct dentry *dentry, void *arg);
>+int au_dcsub_pages(struct au_dcsub_pages *dpages, struct dentry *root,
>+		   au_dpages_test test, void *arg);
>+int au_dcsub_pages_rev(struct au_dcsub_pages *dpages, struct dentry *dentry,
>+		       int do_include, au_dpages_test test, void *arg);
>+int au_test_subdir(struct dentry *d1, struct dentry *d2);
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_DCSUB_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/debug.c linux-2.6.25.4-unionfs/fs/aufs/debug.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/debug.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/debug.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,328 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * debug print functions
>+ *
>+ * $Id: debug.c,v 1.2 2008/04/21 01:33:00 sfjro Exp $
>+ */
>+
>+//#include <linux/errno.h>
>+#include "aufs.h"
>+
>+atomic_t au_cond = ATOMIC_INIT(0);
>+
>+char *au_plevel = KERN_DEBUG;
>+#define dpri(fmt, arg...) do { \
>+	if (LktrCond) \
>+		printk("%s" fmt, au_plevel, ##arg); \
>+} while (0)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void au_dpri_whlist(struct au_nhash *whlist)
>+{
>+	int i;
>+	struct hlist_head *head;
>+	struct au_vdir_wh *tpos;
>+	struct hlist_node *pos;
>+
>+	for (i = 0; i < AuSize_NHASH; i++) {
>+		head = whlist->heads + i;
>+		hlist_for_each_entry(tpos, pos, head, wh_hash)
>+			dpri("b%d, %.*s, %d\n",
>+			     tpos->wh_bindex,
>+			     tpos->wh_str.len, tpos->wh_str.name,
>+			     tpos->wh_str.len);
>+	}
>+}
>+
>+void au_dpri_vdir(struct au_vdir *vdir)
>+{
>+	int i;
>+	union au_vdir_deblk_p p;
>+	unsigned char *o;
>+
>+	if (!vdir || IS_ERR(vdir)) {
>+		dpri("err %ld\n", PTR_ERR(vdir));
>+		return;
>+	}
>+
>+	dpri("nblk %d, deblk %p, last{%d, %p}, ver %lu\n",
>+	     vdir->vd_nblk, vdir->vd_deblk,
>+	     vdir->vd_last.i, vdir->vd_last.p.p, vdir->vd_version);
>+	for (i = 0; i < vdir->vd_nblk; i++) {
>+		p.deblk = vdir->vd_deblk[i];
>+		o = p.p;
>+		dpri("[%d]: %p\n", i, o);
>+	}
>+}
>+
>+static int do_pri_inode(aufs_bindex_t bindex, struct inode *inode,
>+			struct dentry *wh)
>+{
>+	char *n = NULL;
>+	int l = 0, ntfy = 0;
>+
>+	if (!inode || IS_ERR(inode)) {
>+		dpri("i%d: err %ld\n", bindex, PTR_ERR(inode));
>+		return -1;
>+	}
>+
>+	/* the type of i_blocks depends upon CONFIG_LSF */
>+	BUILD_BUG_ON(sizeof(inode->i_blocks) != sizeof(unsigned long)
>+		     && sizeof(inode->i_blocks) != sizeof(u64));
>+	if (wh) {
>+		n = (void *)wh->d_name.name;
>+		l = wh->d_name.len;
>+	}
>+
>+	ntfy = au_test_inotify(inode);
>+	dpri("i%d: i%lu, %s, cnt %d, nl %u, 0%o, ntfy %d, sz %Lu, blk %Lu,"
>+	     " ct %Ld, np %lu, st 0x%lx, f 0x%x, g %x%s%.*s\n",
>+	     bindex,
>+	     inode->i_ino, inode->i_sb ? au_sbtype(inode->i_sb) : "??",
>+	     atomic_read(&inode->i_count), inode->i_nlink, inode->i_mode,
>+	     ntfy,
>+	     i_size_read(inode), (u64)inode->i_blocks,
>+	     timespec_to_ns(&inode->i_ctime) & 0x0ffff,
>+	     inode->i_mapping ? inode->i_mapping->nrpages : 0,
>+	     inode->i_state, inode->i_flags, inode->i_generation,
>+	     l ? ", wh " : "", l, n);
>+	return 0;
>+}
>+
>+void au_dpri_inode(struct inode *inode)
>+{
>+	struct au_iinfo *iinfo;
>+	aufs_bindex_t bindex;
>+	int err;
>+
>+	err = do_pri_inode(-1, inode, NULL);
>+	if (err || !au_test_aufs(inode->i_sb))
>+		return;
>+
>+	iinfo = au_ii(inode);
>+	if (!iinfo)
>+		return;
>+	dpri("i-1: bstart %d, bend %d, gen %d\n",
>+	     iinfo->ii_bstart, iinfo->ii_bend, au_iigen(inode));
>+	if (iinfo->ii_bstart < 0)
>+		return;
>+	for (bindex = iinfo->ii_bstart; bindex <= iinfo->ii_bend; bindex++)
>+		do_pri_inode(bindex, iinfo->ii_hinode[0 + bindex].hi_inode,
>+			     iinfo->ii_hinode[0 + bindex].hi_whdentry);
>+}
>+
>+static int do_pri_dentry(aufs_bindex_t bindex, struct dentry *dentry,
>+			 struct list_head *intent)
>+{
>+	struct dentry *wh = NULL;
>+
>+	if (!dentry || IS_ERR(dentry)) {
>+		dpri("d%d: err %ld\n", bindex, PTR_ERR(dentry));
>+		return -1;
>+	}
>+	/* do not call dget_parent() here */
>+	dpri("d%d: %.*s/%.*s, %s, cnt %d, flags 0x%x, intent %d\n",
>+	     bindex,
>+	     AuDLNPair(dentry->d_parent), AuDLNPair(dentry),
>+	     dentry->d_sb ? au_sbtype(dentry->d_sb) : "??",
>+	     atomic_read(&dentry->d_count), dentry->d_flags, !!intent);
>+	if (bindex >= 0 && dentry->d_inode && au_test_aufs(dentry->d_sb)) {
>+		struct au_iinfo *iinfo = au_ii(dentry->d_inode);
>+		if (iinfo)
>+			wh = iinfo->ii_hinode[0 + bindex].hi_whdentry;
>+	}
>+	do_pri_inode(bindex, dentry->d_inode, wh);
>+	return 0;
>+}
>+
>+static struct list_head *au_dbg_h_intent(struct au_dinfo *dinfo,
>+					 aufs_bindex_t bindex)
>+{
>+#ifdef CONFIG_AUFS_BR_NFS
>+	return dinfo->di_hdentry[0 + bindex].hd_intent_list;
>+#else
>+	return NULL;
>+#endif
>+}
>+
>+void au_dpri_dentry(struct dentry *dentry)
>+{
>+	struct au_dinfo *dinfo;
>+	aufs_bindex_t bindex;
>+	int err;
>+
>+	err = do_pri_dentry(-1, dentry, NULL);
>+	if (err || !au_test_aufs(dentry->d_sb))
>+		return;
>+
>+	dinfo = au_di(dentry);
>+	if (!dinfo)
>+		return;
>+	dpri("d-1: bstart %d, bend %d, bwh %d, bdiropq %d, gen %d\n",
>+	     dinfo->di_bstart, dinfo->di_bend,
>+	     dinfo->di_bwh, dinfo->di_bdiropq, au_digen(dentry));
>+	if (dinfo->di_bstart < 0)
>+		return;
>+	for (bindex = dinfo->di_bstart; bindex <= dinfo->di_bend; bindex++)
>+		do_pri_dentry(bindex, dinfo->di_hdentry[0 + bindex].hd_dentry,
>+			      au_dbg_h_intent(dinfo, bindex));
>+}
>+
>+static int do_pri_file(aufs_bindex_t bindex, struct file *file)
>+{
>+	char a[32];
>+
>+	if (!file || IS_ERR(file)) {
>+		dpri("f%d: err %ld\n", bindex, PTR_ERR(file));
>+		return -1;
>+	}
>+	a[0] = 0;
>+	if (bindex < 0
>+	    && file->f_dentry
>+	    && au_test_aufs(file->f_dentry->d_sb)
>+	    && au_fi(file))
>+		snprintf(a, sizeof(a), ", mmapped %d", au_test_mmapped(file));
>+	dpri("f%d: mode 0x%x, flags 0%o, cnt %d, pos %Lu%s\n",
>+	     bindex, file->f_mode, file->f_flags, file_count(file),
>+	     file->f_pos, a);
>+	if (file->f_dentry)
>+		do_pri_dentry(bindex, file->f_dentry, NULL);
>+	return 0;
>+}
>+
>+void au_dpri_file(struct file *file)
>+{
>+	struct au_finfo *finfo;
>+	aufs_bindex_t bindex;
>+	int err;
>+
>+	err = do_pri_file(-1, file);
>+	if (err || !file->f_dentry || !au_test_aufs(file->f_dentry->d_sb))
>+		return;
>+
>+	finfo = au_fi(file);
>+	if (!finfo)
>+		return;
>+	if (finfo->fi_bstart < 0)
>+		return;
>+	for (bindex = finfo->fi_bstart; bindex <= finfo->fi_bend; bindex++) {
>+		struct au_hfile *hf;
>+		//dpri("bindex %d\n", bindex);
>+		hf = finfo->fi_hfile + bindex;
>+		do_pri_file(bindex, hf ? hf->hf_file : NULL);
>+	}
>+}
>+
>+static int do_pri_br(aufs_bindex_t bindex, struct au_branch *br)
>+{
>+	struct vfsmount *mnt;
>+	struct super_block *sb;
>+
>+	if (!br || IS_ERR(br)
>+	    || !(mnt = br->br_mnt) || IS_ERR(mnt)
>+	    || !(sb = mnt->mnt_sb) || IS_ERR(sb)) {
>+		dpri("s%d: err %ld\n", bindex, PTR_ERR(br));
>+		return -1;
>+	}
>+
>+	dpri("s%d: {perm 0x%x, cnt %d}, "
>+	     "%s, flags 0x%lx, cnt(BIAS) %d, active %d, xino %d\n",
>+	     bindex, br->br_perm, au_br_count(br),
>+	     au_sbtype(sb), sb->s_flags, sb->s_count - S_BIAS,
>+	     atomic_read(&sb->s_active), !!br->br_xino);
>+	return 0;
>+}
>+
>+void au_dpri_sb(struct super_block *sb)
>+{
>+	struct au_sbinfo *sbinfo;
>+	aufs_bindex_t bindex;
>+	int err;
>+	struct vfsmount mnt = { .mnt_sb = sb };
>+	struct au_branch fake = {
>+		.br_perm = 0,
>+		.br_mnt = &mnt,
>+		.br_count = ATOMIC_INIT(0),
>+		.br_xino = NULL
>+	};
>+
>+	atomic_set(&fake.br_count, 0);
>+	smp_mb(); /* atomic_set */
>+	err = do_pri_br(-1, &fake);
>+	dpri("dev 0x%x\n", sb->s_dev);
>+	if (err || !au_test_aufs(sb))
>+		return;
>+
>+	sbinfo = au_sbi(sb);
>+	if (!sbinfo)
>+		return;
>+	for (bindex = 0; bindex <= sbinfo->si_bend; bindex++) {
>+		//dpri("bindex %d\n", bindex);
>+		do_pri_br(bindex, sbinfo->si_branch[0 + bindex]);
>+	}
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void au_dbg_sleep(int sec)
>+{
>+	static DECLARE_WAIT_QUEUE_HEAD(wq);
>+	wait_event_timeout(wq, 0, sec * HZ);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void au_debug_sbinfo_init(struct au_sbinfo *sbinfo)
>+{
>+#ifdef ForceInotify
>+	au_opt_set_udba(sbinfo->si_mntflags, UDBA_INOTIFY);
>+#endif
>+#ifdef ForceDlgt
>+	au_opt_set(sbinfo->si_mntflags, DLGT);
>+#endif
>+#ifdef ForceNoPlink
>+	au_opt_clr(sbinfo->si_mntflags, PLINK);
>+#endif
>+#ifdef ForceNoXino
>+	au_opt_clr(sbinfo->si_mntflags, XINO);
>+#endif
>+#ifdef ForceNoRefrof
>+	au_opt_clr(sbinfo->si_mntflags, REFROF);
>+#endif
>+}
>+
>+int __init au_debug_init(void)
>+{
>+	aufs_bindex_t bindex;
>+	struct au_vdir_destr destr;
>+
>+	bindex = -1;
>+	AuDebugOn(bindex >= 0);
>+
>+	destr.len = -1;
>+	AuDebugOn(destr.len < NAME_MAX);
>+
>+#ifdef CONFIG_4KSTACKS
>+	AuWarn("CONFIG_4KSTACKS is defined.\n");
>+#endif
>+
>+	return 0;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/debug.h linux-2.6.25.4-unionfs/fs/aufs/debug.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/debug.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/debug.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,210 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * debug print functions
>+ *
>+ * $Id: debug.h,v 1.2 2008/04/21 02:00:37 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_DEBUG_H__
>+#define __AUFS_DEBUG_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+
>+/* to debug easier, do not make it an inlined function */
>+#define MtxMustLock(mtx)	AuDebugOn(!mutex_is_locked(mtx))
>+
>+#ifdef CONFIG_AUFS_DEBUG
>+/* sparse warns about pointer */
>+#define AuDebugOn(a)		BUG_ON(!!(a))
>+extern atomic_t au_cond;
>+#define au_debug_on()		atomic_inc_return(&au_cond)
>+#define au_debug_off()		atomic_dec_return(&au_cond)
>+static inline int au_debug_test(void)
>+{
>+	return atomic_read(&au_cond);
>+}
>+#else
>+#define AuDebugOn(a)		do {} while (0)
>+#define au_debug_on()		do {} while (0)
>+#define au_debug_off()		do {} while (0)
>+static inline int au_debug_test(void)
>+{
>+	return 0;
>+}
>+#endif /* CONFIG_AUFS_DEBUG */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* debug print */
>+#if defined(CONFIG_LKTR) || defined(CONFIG_LKTR_MODULE)
>+#include <linux/lktr.h>
>+#ifdef CONFIG_AUFS_DEBUG
>+#undef LktrCond
>+#define LktrCond	unlikely(au_debug_test() || (lktr_cond && lktr_cond()))
>+#endif
>+#else
>+#define LktrCond			au_debug_test()
>+#define LKTRDumpVma(pre, vma, suf)	do {} while (0)
>+#define LKTRDumpStack()			do {} while (0)
>+#define LKTRTrace(fmt, args...) do { \
>+	if (LktrCond) \
>+		AuDbg(fmt, ##args); \
>+} while (0)
>+#define LKTRLabel(label)		LKTRTrace("%s\n", #label)
>+#endif /* CONFIG_LKTR */
>+
>+#define AuTraceErr(e) do { \
>+	if (unlikely((e) < 0)) \
>+		LKTRTrace("err %d\n", (int)(e)); \
>+} while (0)
>+
>+#define AuTraceErrPtr(p) do { \
>+	if (IS_ERR(p)) \
>+		LKTRTrace("err %ld\n", PTR_ERR(p)); \
>+} while (0)
>+
>+#define AuTraceEnter()	LKTRLabel(enter)
>+
>+/* dirty macros for debug print, use with "%.*s" and caution */
>+#define AuLNPair(qstr)		(qstr)->len, (qstr)->name
>+#define AuDLNPair(d)		AuLNPair(&(d)->d_name)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#define AuDpri(lvl, fmt, arg...) \
>+	printk(lvl AUFS_NAME " %s:%d:%s[%d]: " fmt, \
>+	       __func__, __LINE__, current->comm, current->pid, ##arg)
>+#define AuDbg(fmt, arg...)	AuDpri(KERN_DEBUG, fmt, ##arg)
>+#define AuInfo(fmt, arg...)	AuDpri(KERN_INFO, fmt, ##arg)
>+#define AuWarn(fmt, arg...)	AuDpri(KERN_WARNING, fmt, ##arg)
>+#define AuErr(fmt, arg...)	AuDpri(KERN_ERR, fmt, ##arg)
>+#define AuIOErr(fmt, arg...)	AuErr("I/O Error, " fmt, ##arg)
>+#define AuIOErrWhck(fmt, arg...) AuErr("I/O Error, try whck. " fmt, ##arg)
>+#define AuWarn1(fmt, arg...) do { \
>+	static unsigned char _c; \
>+	if (!_c++) AuWarn(fmt, ##arg); \
>+} while (0)
>+
>+#define AuErr1(fmt, arg...) do { \
>+	static unsigned char _c; \
>+	if (!_c++) AuErr(fmt, ##arg); \
>+} while (0)
>+
>+#define AuIOErr1(fmt, arg...) do { \
>+	static unsigned char _c; \
>+	if (!_c++) AuIOErr(fmt, ##arg); \
>+} while (0)
>+
>+#define AuUnsupportMsg	"This operation is not supported." \
>+			" Please report this application to aufs-users ML."
>+#define AuUnsupport(fmt, args...) do { \
>+	AuErr(AuUnsupportMsg "\n" fmt, ##args); \
>+	dump_stack(); \
>+} while (0)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_sbinfo;
>+#ifdef CONFIG_AUFS_DEBUG
>+extern char *au_plevel;
>+struct au_nhash;
>+void au_dpri_whlist(struct au_nhash *whlist);
>+struct au_vdir;
>+void au_dpri_vdir(struct au_vdir *vdir);
>+void au_dpri_inode(struct inode *inode);
>+void au_dpri_dentry(struct dentry *dentry);
>+void au_dpri_file(struct file *filp);
>+void au_dpri_sb(struct super_block *sb);
>+void au_dbg_sleep(int sec);
>+int __init au_debug_init(void);
>+void au_debug_sbinfo_init(struct au_sbinfo *sbinfo);
>+#define AuDbgWhlist(w) do { \
>+	LKTRTrace(#w "\n"); \
>+	au_dpri_whlist(w); \
>+} while (0)
>+
>+#define AuDbgVdir(v) do { \
>+	LKTRTrace(#v "\n"); \
>+	au_dpri_vdir(v); \
>+} while (0)
>+
>+#define AuDbgInode(i) do { \
>+	LKTRTrace(#i "\n"); \
>+	au_dpri_inode(i); \
>+} while (0)
>+
>+#define AuDbgDentry(d) do { \
>+	LKTRTrace(#d "\n"); \
>+	au_dpri_dentry(d); \
>+} while (0)
>+
>+#define AuDbgFile(f) do { \
>+	LKTRTrace(#f "\n"); \
>+	au_dpri_file(f); \
>+} while (0)
>+
>+#define AuDbgSb(sb) do { \
>+	LKTRTrace(#sb "\n"); \
>+	au_dpri_sb(sb); \
>+} while (0)
>+
>+#define AuDbgSleep(sec) do { \
>+	AuDbg("sleep %d sec\n", sec); \
>+	au_dbg_sleep(sec); \
>+} while (0)
>+#else
>+static inline int au_debug_init(void)
>+{
>+	return 0;
>+}
>+static inline void au_debug_sbinfo_init(struct au_sbinfo *sbinfo)
>+{
>+	/* empty */
>+}
>+#define AuDbgWhlist(w)		do {} while (0)
>+#define AuDbgVdir(v)		do {} while (0)
>+#define AuDbgInode(i)		do {} while (0)
>+#define AuDbgDentry(d)		do {} while (0)
>+#define AuDbgFile(f)		do {} while (0)
>+#define AuDbgSb(sb)		do {} while (0)
>+#define AuDbgSleep(sec)		do {} while (0)
>+#endif /* CONFIG_AUFS_DEBUG */
>+
>+#ifdef DbgUdbaRace
>+#define AuDbgSleep_UdbaRace()	AuDbgSleep(DbgUdbaRace)
>+#else
>+#define AuDbgSleep_UdbaRace()	do {} while (0)
>+#endif
>+
>+#ifdef CONFIG_AUFS_MAGIC_SYSRQ
>+int __init au_sysrq_init(void);
>+void au_sysrq_fin(void);
>+#else
>+static inline int au_sysrq_init(void)
>+{
>+	return 0;
>+}
>+#define au_sysrq_fin()		do {} while (0)
>+#endif
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_DEBUG_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/dentry.c linux-2.6.25.4-unionfs/fs/aufs/dentry.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/dentry.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/dentry.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,976 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * lookup and dentry operations
>+ *
>+ * $Id: dentry.c,v 1.6 2008/05/19 01:46:53 sfjro Exp $
>+ */
>+
>+//#include <linux/fs.h>
>+//#include <linux/namei.h>
>+#include "aufs.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * au_lkup_one() is a generic abstract entry function which calls
>+ * lookup_one_len() or __lookup_hash() finally. it is some condisions that makes
>+ * lookup complicated, which are nfs branch, open-intent and dlgt mode.
>+ */
>+
>+#if defined(CONFIG_AUFS_BR_NFS) || defined(CONFIG_AUFS_DLGT)
>+/* cf. lookup_one_len() in linux/fs/namei.c */
>+struct dentry *au_lkup_one(const char *name, struct dentry *parent, int len,
>+			   struct au_ndx *ndx)
>+{
>+	struct dentry *dentry;
>+
>+	LKTRTrace("%.*s/%.*s, ndx{%d, 0x%x}\n",
>+		  AuDLNPair(parent), len, name, !!ndx->nfsmnt, ndx->flags);
>+
>+	ndx->nd_file = NULL;
>+	if (!ndx->nfsmnt)
>+		dentry = au_lkup_one_dlgt(name, parent, len, ndx->flags);
>+	else
>+		dentry = au_lkup_hash(name, parent, len, ndx);
>+
>+	AuTraceErrPtr(dentry);
>+	return dentry;
>+}
>+#endif /* CONFIG_AUFS_BR_NFS || CONFIG_AUFS_DLGT */
>+
>+struct au_lkup_one_args {
>+	struct dentry **errp;
>+	const char *name;
>+	struct dentry *parent;
>+	int len;
>+	struct au_ndx *ndx;
>+};
>+
>+static void au_call_lkup_one(void *args)
>+{
>+	struct au_lkup_one_args *a = args;
>+	*a->errp = au_lkup_one(a->name, a->parent, a->len, a->ndx);
>+}
>+
>+#define AuLkup_ALLOW_NEG	1
>+#define AuLkup_DLGT		(1 << 1)
>+#define AuLkup_DIRPERM1		(1 << 2)
>+#define au_ftest_lkup(flags, name)	((flags) & AuLkup_##name)
>+#define au_fset_lkup(flags, name)	{ (flags) |= AuLkup_##name; }
>+#define au_fclr_lkup(flags, name)	{ (flags) &= ~AuLkup_##name; }
>+#ifndef CONFIG_AUFS_DLGT
>+#undef AuLkup_DLGT
>+#define AuLkup_DLGT	0
>+#undef AuLkup_DIRPERM1
>+#define AuLkup_DIRPERM1	0
>+#endif
>+
>+struct au_do_lookup_args {
>+	unsigned int		flags;
>+	mode_t			type;
>+	struct nameidata	*nd;
>+};
>+
>+/*
>+ * returns positive/negative dentry, NULL or an error.
>+ * NULL means whiteout-ed or not-found.
>+ */
>+static noinline_for_stack
>+struct dentry *au_do_lookup(struct dentry *h_parent, struct dentry *dentry,
>+			    aufs_bindex_t bindex, struct qstr *wh_name,
>+			    struct au_do_lookup_args *args)
>+{
>+	struct dentry *h_dentry;
>+	int wh_found, wh_able, opq, err;
>+	struct inode *h_dir, *h_inode, *inode;
>+	struct qstr *name;
>+	struct super_block *sb;
>+	unsigned int nd_flags;
>+	struct au_ndx ndx = {
>+		.flags	= 0,
>+		.nd	= args->nd
>+	};
>+	const int allow_neg = au_ftest_lkup(args->flags, ALLOW_NEG);
>+
>+	LKTRTrace("%.*s/%.*s, b%d, {flags 0x%x, type 0%o, nd %d}\n",
>+		  AuDLNPair(h_parent), AuDLNPair(dentry), bindex,
>+		  args->flags, args->type, !!args->nd);
>+	if (args->nd)
>+		LKTRTrace("nd{0x%x}\n", args->nd->flags);
>+	AuDebugOn(IS_ROOT(dentry));
>+	h_dir = h_parent->d_inode;
>+
>+	nd_flags = 0;
>+	wh_found = 0;
>+	sb = dentry->d_sb;
>+	ndx.nfsmnt = au_nfsmnt(sb, bindex);
>+	if (unlikely(au_ftest_lkup(args->flags, DLGT)))
>+		au_fset_ndx(ndx.flags, DLGT);
>+	if (unlikely(au_ftest_lkup(args->flags, DIRPERM1)))
>+		au_fset_ndx(ndx.flags, DIRPERM1);
>+	LKTRTrace("nfsmnt %p\n", ndx.nfsmnt);
>+	ndx.br = au_sbr(sb, bindex);
>+	wh_able = au_br_whable(ndx.br->br_perm);
>+	name = &dentry->d_name;
>+	if (unlikely(wh_able))
>+		wh_found = au_test_robr_wh(name, h_parent, wh_name,
>+					   /*try_sio*/0, &ndx);
>+	//if (LktrCond) wh_found = -1;
>+	h_dentry = ERR_PTR(wh_found);
>+	if (!wh_found)
>+		goto real_lookup;
>+	if (unlikely(wh_found < 0))
>+		goto out;
>+
>+	/* We found a whiteout */
>+	//au_set_dbend(dentry, bindex);
>+	au_set_dbwh(dentry, bindex);
>+	if (!allow_neg)
>+		return NULL; /* success */
>+	if (unlikely(ndx.nd
>+		     && au_test_nfs(h_parent->d_sb)
>+		     && (ndx.nd->flags & LOOKUP_CREATE))) {
>+		nd_flags = ndx.nd->flags;
>+		ndx.nd->flags &= ~(LOOKUP_OPEN | LOOKUP_CREATE);
>+	}
>+
>+ real_lookup:
>+	/* do not superio. */
>+	h_dentry = au_lkup_one(name->name, h_parent, name->len, &ndx);
>+	//if (LktrCond) {dput(h_dentry); h_dentry = ERR_PTR(-1);}
>+	if (IS_ERR(h_dentry))
>+		goto out;
>+	AuDebugOn(d_unhashed(h_dentry));
>+	h_inode = h_dentry->d_inode;
>+	if (!h_inode) {
>+		if (!allow_neg)
>+			goto out_neg;
>+	} else if (wh_found
>+		   || (args->type && args->type != (h_inode->i_mode & S_IFMT)))
>+		goto out_neg;
>+
>+	if (au_dbend(dentry) <= bindex)
>+		au_set_dbend(dentry, bindex);
>+	if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry))
>+		au_set_dbstart(dentry, bindex);
>+	au_set_h_dptr(dentry, bindex, h_dentry);
>+
>+	err = au_br_nfs_h_intent(ndx.nd_file, dentry, bindex, args->nd);
>+	if (unlikely(err)) {
>+		h_dentry = ERR_PTR(err);
>+		goto out;
>+	}
>+
>+	inode = dentry->d_inode;
>+	if (!h_inode || !S_ISDIR(h_inode->i_mode) || !wh_able
>+	    || (inode && !S_ISDIR(inode->i_mode)))
>+		goto out; /* success */
>+
>+	mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
>+	opq = au_diropq_test(h_dentry, &ndx);
>+	//if (LktrCond) opq = -1;
>+	mutex_unlock(&h_inode->i_mutex);
>+	if (opq > 0)
>+		au_set_dbdiropq(dentry, bindex);
>+	else if (unlikely(opq < 0)) {
>+		au_set_h_dptr(dentry, bindex, NULL);
>+		h_dentry = ERR_PTR(opq);
>+	}
>+	goto out;
>+
>+ out_neg:
>+	dput(h_dentry);
>+	h_dentry = NULL;
>+ out:
>+	if (unlikely(nd_flags))
>+		ndx.nd->flags |= (nd_flags & (LOOKUP_OPEN | LOOKUP_CREATE));
>+	AuTraceErrPtr(h_dentry);
>+	return h_dentry;
>+}
>+
>+/*
>+ * returns the number of hidden positive dentries,
>+ * otherwise an error.
>+ * can be called at unlinking with @type is zero.
>+ */
>+int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t bstart, mode_t type,
>+		   struct nameidata *nd)
>+{
>+	int npositive, err, isdir;
>+	struct dentry *parent;
>+	aufs_bindex_t bindex, btail, bdiropq;
>+	const struct qstr *name = &dentry->d_name;
>+	struct qstr whname;
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+	struct inode *inode;
>+	struct au_do_lookup_args args = {
>+		.type	= type,
>+		.nd	= nd
>+	};
>+
>+	LKTRTrace("%.*s, b%d, type 0%o\n", AuLNPair(name), bstart, type);
>+	AuDebugOn(bstart < 0 || IS_ROOT(dentry));
>+
>+	/* dir may not be locked */
>+	parent = dget_parent(dentry);
>+
>+	err = au_test_robr_shwh(dentry->d_sb, name);
>+	if (unlikely(err))
>+		goto out;
>+
>+	err = au_wh_name_alloc(name->name, name->len, &whname);
>+	//if (LktrCond) {au_wh_name_free(&whname); err = -1;}
>+	if (unlikely(err))
>+		goto out;
>+
>+	sb = dentry->d_sb;
>+	mnt_flags = au_mntflags(sb);
>+	inode = dentry->d_inode;
>+	isdir = (inode && S_ISDIR(inode->i_mode));
>+	args.flags = 0;
>+	if (unlikely(au_opt_test_dlgt(mnt_flags)))
>+		au_fset_lkup(args.flags, DLGT);
>+	if (unlikely(au_opt_test_dirperm1(mnt_flags)))
>+		au_fset_lkup(args.flags, DIRPERM1);
>+	if (!type)
>+		au_fset_lkup(args.flags, ALLOW_NEG);
>+	npositive = 0;
>+	btail = au_dbtaildir(parent);
>+	for (bindex = bstart; bindex <= btail; bindex++) {
>+		struct dentry *h_parent, *h_dentry;
>+		struct inode *h_inode, *h_dir;
>+
>+		h_dentry = au_h_dptr(dentry, bindex);
>+		if (h_dentry) {
>+			if (h_dentry->d_inode)
>+				npositive++;
>+			if (type != S_IFDIR)
>+				break;
>+			continue;
>+		}
>+		h_parent = au_h_dptr(parent, bindex);
>+		if (!h_parent)
>+			continue;
>+		h_dir = h_parent->d_inode;
>+		if (!h_dir || !S_ISDIR(h_dir->i_mode))
>+			continue;
>+
>+		mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
>+		h_dentry = au_do_lookup(h_parent, dentry, bindex, &whname,
>+					&args);
>+		// do not dput for testing
>+		//if (LktrCond) {h_dentry = ERR_PTR(-1);}
>+		mutex_unlock(&h_dir->i_mutex);
>+		err = PTR_ERR(h_dentry);
>+		if (IS_ERR(h_dentry))
>+			goto out_wh;
>+		au_fclr_lkup(args.flags, ALLOW_NEG);
>+
>+		if (au_dbwh(dentry) >= 0)
>+			break;
>+		if (!h_dentry)
>+			continue;
>+		h_inode = h_dentry->d_inode;
>+		if (!h_inode)
>+			continue;
>+		npositive++;
>+		if (!args.type)
>+			args.type = h_inode->i_mode & S_IFMT;
>+		if (args.type != S_IFDIR)
>+			break;
>+		else if (isdir) {
>+			/* the type of lowers may be different */
>+			bdiropq = au_dbdiropq(dentry);
>+			if (bdiropq >= 0 && bdiropq <= bindex)
>+				break;
>+		}
>+	}
>+
>+	if (npositive) {
>+		LKTRLabel(positive);
>+		au_update_dbstart(dentry);
>+	}
>+	err = npositive;
>+
>+ out_wh:
>+	au_wh_name_free(&whname);
>+ out:
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+struct dentry *au_sio_lkup_one(const char *name, struct dentry *parent, int len,
>+			       struct au_ndx *ndx)
>+{
>+	struct dentry *dentry;
>+	int wkq_err;
>+
>+	LKTRTrace("%.*s/%.*s\n", AuDLNPair(parent), len, name);
>+
>+	if (!au_test_h_perm_sio(parent->d_inode, MAY_EXEC,
>+				au_ftest_ndx(ndx->flags, DLGT)))
>+		dentry = au_lkup_one(name, parent, len, ndx);
>+	else {
>+		// ugly
>+		unsigned int flags = ndx->flags;
>+		struct au_lkup_one_args args = {
>+			.errp	= &dentry,
>+			.name	= name,
>+			.parent	= parent,
>+			.len	= len,
>+			.ndx	= ndx
>+		};
>+
>+		au_fclr_ndx(ndx->flags, DLGT);
>+		au_fclr_ndx(ndx->flags, DIRPERM1);
>+		wkq_err = au_wkq_wait(au_call_lkup_one, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			dentry = ERR_PTR(wkq_err);
>+		ndx->flags = flags;
>+	}
>+
>+	AuTraceErrPtr(dentry);
>+	return dentry;
>+}
>+
>+/*
>+ * lookup @dentry on @bindex which should be negative.
>+ */
>+int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex)
>+{
>+	int err;
>+	struct dentry *parent, *h_parent, *h_dentry;
>+	struct inode *h_dir;
>+	struct au_ndx ndx = {
>+		.flags	= 0,
>+		.nd	= NULL,
>+		//.br	= NULL
>+	};
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+
>+	LKTRTrace("%.*s, b%d\n", AuDLNPair(dentry), bindex);
>+	/* dir may not be locked */
>+	parent = dget_parent(dentry);
>+	AuDebugOn(!parent || !parent->d_inode
>+		  || !S_ISDIR(parent->d_inode->i_mode));
>+	h_parent = au_h_dptr(parent, bindex);
>+	AuDebugOn(!h_parent);
>+	h_dir = h_parent->d_inode;
>+	AuDebugOn(!h_dir || !S_ISDIR(h_dir->i_mode));
>+
>+	sb = dentry->d_sb;
>+	mnt_flags = au_mntflags(sb);
>+	ndx.nfsmnt = au_nfsmnt(sb, bindex);
>+	if (unlikely(au_opt_test_dlgt(mnt_flags)))
>+		au_fset_ndx(ndx.flags, DLGT);
>+	if (unlikely(au_opt_test_dirperm1(mnt_flags)))
>+		au_fset_ndx(ndx.flags, DIRPERM1);
>+	h_dentry = au_sio_lkup_one(dentry->d_name.name, h_parent,
>+				   dentry->d_name.len, &ndx);
>+	//if (LktrCond) {dput(h_dentry); h_dentry = ERR_PTR(-1);}
>+	err = PTR_ERR(h_dentry);
>+	if (IS_ERR(h_dentry))
>+		goto out;
>+	if (unlikely(h_dentry->d_inode)) {
>+		err = -EIO;
>+		AuIOErr("b%d %.*s should be negative.\n",
>+			bindex, AuDLNPair(h_dentry));
>+		dput(h_dentry);
>+		goto out;
>+	}
>+
>+	if (bindex < au_dbstart(dentry))
>+		au_set_dbstart(dentry, bindex);
>+	if (au_dbend(dentry) < bindex)
>+		au_set_dbend(dentry, bindex);
>+	au_set_h_dptr(dentry, bindex, h_dentry);
>+	err = 0;
>+
>+ out:
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * returns the number of found hidden positive dentries,
>+ * otherwise an error.
>+ */
>+int au_refresh_hdentry(struct dentry *dentry, mode_t type)
>+{
>+	int npositive, new_sz;
>+	struct au_dinfo *dinfo;
>+	struct super_block *sb;
>+	struct dentry *parent;
>+	aufs_bindex_t bindex, parent_bend, parent_bstart, bwh, bdiropq, bend;
>+	struct au_hdentry *p;
>+	au_gen_t sgen;
>+
>+	LKTRTrace("%.*s, type 0%o\n", AuDLNPair(dentry), type);
>+	DiMustWriteLock(dentry);
>+	sb = dentry->d_sb;
>+	AuDebugOn(IS_ROOT(dentry));
>+	sgen = au_sigen(sb);
>+	parent = dget_parent(dentry);
>+	AuDebugOn(au_digen(parent) != sgen
>+		  || au_iigen(parent->d_inode) != sgen);
>+
>+	npositive = -ENOMEM;
>+	new_sz = sizeof(*dinfo->di_hdentry) * (au_sbend(sb) + 1);
>+	dinfo = au_di(dentry);
>+	p = au_kzrealloc(dinfo->di_hdentry, sizeof(*p) * (dinfo->di_bend + 1),
>+			 new_sz, GFP_KERNEL);
>+	//p = NULL;
>+	if (unlikely(!p))
>+		goto out;
>+	dinfo->di_hdentry = p;
>+
>+	bend = dinfo->di_bend;
>+	bwh = dinfo->di_bwh;
>+	bdiropq = dinfo->di_bdiropq;
>+	p += dinfo->di_bstart;
>+	for (bindex = dinfo->di_bstart; bindex <= bend; bindex++, p++) {
>+		struct dentry *hd, *hdp;
>+		struct au_hdentry tmp, *q;
>+		aufs_bindex_t new_bindex;
>+
>+		hd = p->hd_dentry;
>+		if (!hd)
>+			continue;
>+		hdp = dget_parent(hd);
>+		if (hdp == au_h_dptr(parent, bindex)) {
>+			dput(hdp);
>+			continue;
>+		}
>+
>+		new_bindex = au_find_dbindex(parent, hdp);
>+		dput(hdp);
>+		AuDebugOn(new_bindex == bindex);
>+		if (dinfo->di_bwh == bindex)
>+			bwh = new_bindex;
>+		if (dinfo->di_bdiropq == bindex)
>+			bdiropq = new_bindex;
>+		if (new_bindex < 0) { // test here
>+			au_hdput(p, /*do_free*/0);
>+			p->hd_dentry = NULL;
>+			continue;
>+		}
>+		/* swap two hidden dentries, and loop again */
>+		q = dinfo->di_hdentry + new_bindex;
>+		tmp = *q;
>+		*q = *p;
>+		*p = tmp;
>+		if (tmp.hd_dentry) {
>+			bindex--;
>+			p--;
>+		}
>+	}
>+
>+	// test here
>+	dinfo->di_bwh = -1;
>+	if (unlikely(bwh >= 0 && bwh <= au_sbend(sb) && au_sbr_whable(sb, bwh)))
>+		dinfo->di_bwh = bwh;
>+	dinfo->di_bdiropq = -1;
>+	if (unlikely(bdiropq >= 0 && bdiropq <= au_sbend(sb)
>+		     && au_sbr_whable(sb, bdiropq)))
>+		dinfo->di_bdiropq = bdiropq;
>+	parent_bend = au_dbend(parent);
>+	p = dinfo->di_hdentry;
>+	for (bindex = 0; bindex <= parent_bend; bindex++, p++)
>+		if (p->hd_dentry) {
>+			dinfo->di_bstart = bindex;
>+			break;
>+		}
>+	p = dinfo->di_hdentry + parent_bend;
>+	//for (bindex = parent_bend; bindex > dinfo->di_bstart; bindex--, p--)
>+	for (bindex = parent_bend; bindex >= 0; bindex--, p--)
>+		if (p->hd_dentry) {
>+			dinfo->di_bend = bindex;
>+			break;
>+		}
>+
>+	npositive = 0;
>+	parent_bstart = au_dbstart(parent);
>+	if (type != S_IFDIR && dinfo->di_bstart == parent_bstart)
>+		goto out_dgen; /* success */
>+
>+	npositive = au_lkup_dentry(dentry, parent_bstart, type, /*nd*/NULL);
>+	//if (LktrCond) npositive = -1;
>+	if (npositive < 0)
>+		goto out;
>+	if (unlikely(dinfo->di_bwh >= 0 && dinfo->di_bwh <= dinfo->di_bstart))
>+		d_drop(dentry);
>+
>+ out_dgen:
>+	au_update_digen(dentry);
>+ out:
>+	dput(parent);
>+	AuTraceErr(npositive);
>+	return npositive;
>+}
>+
>+static int au_lock_nd(struct dentry *dentry, struct nameidata *nd)
>+{
>+	int locked = 0;
>+	if (nd && dentry != nd->path.dentry) {
>+		di_read_lock_parent(nd->path.dentry, 0);
>+		locked = 1;
>+	}
>+	return locked;
>+}
>+
>+static void au_unlock_nd(int locked, struct nameidata *nd)
>+{
>+	if (locked)
>+		di_read_unlock(nd->path.dentry, 0);
>+}
>+
>+//#define TestingFuse
>+static noinline_for_stack int
>+au_do_h_d_reval(struct dentry *dentry, aufs_bindex_t bindex,
>+		struct nameidata *nd, struct dentry *h_dentry)
>+{
>+	int err, valid, e;
>+	int (*reval)(struct dentry *, struct nameidata *);
>+	struct super_block *sb;
>+	struct nameidata fake_nd, *p;
>+
>+	LKTRTrace("%.*s, b%d, nd %d\n", AuDLNPair(dentry), bindex, !!nd);
>+
>+	err = 0;
>+	reval = NULL;
>+	if (h_dentry->d_op)
>+		reval = h_dentry->d_op->d_revalidate;
>+	if (!reval)
>+		goto out;
>+
>+	sb = dentry->d_sb;
>+	if (nd) {
>+		memcpy(&fake_nd, nd, sizeof(*nd));
>+		err = au_fake_intent(&fake_nd, au_sbr_perm(sb, bindex));
>+		if (unlikely(err)) {
>+			err = -EINVAL;
>+			goto out;
>+		}
>+	}
>+	p = au_fake_dm(&fake_nd, nd, sb, bindex);
>+	AuDebugOn(IS_ERR(p));
>+	AuDebugOn(nd && p != &fake_nd);
>+	LKTRTrace("b%d\n", bindex);
>+
>+	/* it may return tri-state */
>+	valid = reval(h_dentry, p);
>+	if (unlikely(valid < 0))
>+		err = valid;
>+	else if (!valid)
>+		err = -EINVAL;
>+	else
>+		AuDebugOn(err);
>+
>+	if (p) {
>+		AuDebugOn(!nd);
>+		e = au_hin_after_reval(p, dentry, bindex, nd->intent.open.file);
>+#ifndef TestingFuse
>+		au_update_fuse_h_inode(p->path.mnt, h_dentry); /*ignore*/
>+#endif
>+		if (unlikely(e && !err))
>+			err = e;
>+	}
>+#ifndef TestingFuse
>+	else
>+		au_update_fuse_h_inode(NULL, h_dentry); /*ignore*/
>+#endif
>+	au_fake_dm_release(p);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static noinline_for_stack int
>+h_d_revalidate(struct dentry *dentry, struct inode *inode,
>+	       struct nameidata *nd, int do_udba)
>+{
>+	int err, plus, locked, unhashed, is_root, h_plus;
>+	aufs_bindex_t bindex, btail, bstart, ibs, ibe;
>+	struct super_block *sb;
>+	struct inode *first, *h_inode, *h_cached_inode;
>+	umode_t mode, h_mode;
>+	struct dentry *h_dentry;
>+	struct qstr *name;
>+
>+	LKTRTrace("%.*s, nd %d\n", AuDLNPair(dentry), !!nd);
>+	AuDebugOn(inode && au_digen(dentry) != au_iigen(inode));
>+
>+	err = 0;
>+	sb = dentry->d_sb;
>+	plus = 0;
>+	mode = 0;
>+	first = NULL;
>+	ibs = -1;
>+	ibe = -1;
>+	unhashed = d_unhashed(dentry);
>+	is_root = IS_ROOT(dentry);
>+	name = &dentry->d_name;
>+
>+	/*
>+	 * Theoretically, REVAL test should be unnecessary in case of INOTIFY.
>+	 * But inotify doesn't fire some necessary events,
>+	 *	IN_ATTRIB for atime/nlink/pageio
>+	 *	IN_DELETE for NFS dentry
>+	 * Let's do REVAL test too.
>+	 */
>+	if (do_udba && inode) {
>+		mode = (inode->i_mode & S_IFMT);
>+		plus = (inode->i_nlink > 0);
>+		first = au_h_iptr(inode, au_ibstart(inode));
>+		ibs = au_ibstart(inode);
>+		ibe = au_ibend(inode);
>+	}
>+
>+	bstart = au_dbstart(dentry);
>+	btail = bstart;
>+	if (inode && S_ISDIR(inode->i_mode))
>+		btail = au_dbtaildir(dentry);
>+	locked = au_lock_nd(dentry, nd);
>+	for (bindex = bstart; bindex <= btail; bindex++) {
>+		h_dentry = au_h_dptr(dentry, bindex);
>+		if (!h_dentry)
>+			continue;
>+
>+		LKTRTrace("b%d, %.*s\n", bindex, AuDLNPair(h_dentry));
>+#ifdef TestingFuse
>+		/* force re-lookup for fuse, in order to update attributes */
>+		if (unlikely(au_test_fuse(h_dentry->d_sb)))
>+			goto err;
>+#endif
>+
>+		if (unlikely(do_udba
>+			     && !is_root
>+			     && (unhashed != d_unhashed(h_dentry)
>+				 || name->len != h_dentry->d_name.len
>+				 || memcmp(name->name, h_dentry->d_name.name,
>+					   name->len)
>+				     ))) {
>+			LKTRTrace("unhash 0x%x 0x%x, %.*s %.*s\n",
>+				  unhashed, d_unhashed(h_dentry),
>+				  AuDLNPair(dentry), AuDLNPair(h_dentry));
>+			goto err;
>+		}
>+
>+		err = au_do_h_d_reval(dentry, bindex, nd, h_dentry);
>+		if (unlikely(err))
>+			/* do not goto err, to keep the errno */
>+			break;
>+
>+		if (unlikely(!do_udba))
>+			continue;
>+
>+		/* UDBA tests */
>+		h_inode = h_dentry->d_inode;
>+		if (unlikely(!!inode != !!h_inode)) {
>+			//AuDbg("here\n");
>+			goto err;
>+		}
>+
>+		h_plus = plus;
>+		h_mode = mode;
>+		h_cached_inode = h_inode;
>+		if (h_inode) {
>+			h_mode = (h_inode->i_mode & S_IFMT);
>+			h_plus = (h_inode->i_nlink > 0);
>+			//AuDbgInode(inode);
>+			//AuDbgInode(h_inode);
>+		}
>+		if (inode && ibs <= bindex && bindex <= ibe)
>+			h_cached_inode = au_h_iptr(inode, bindex);
>+
>+		LKTRTrace("{%d, 0%o, %d}, h{%d, 0%o, %d}\n",
>+			  plus, mode, !!h_cached_inode,
>+			  h_plus, h_mode, !!h_inode);
>+		if (unlikely(plus != h_plus
>+			     || mode != h_mode
>+			     || h_cached_inode != h_inode))
>+			goto err;
>+		continue;
>+
>+	err:
>+		err = -EINVAL;
>+		break;
>+	}
>+	au_unlock_nd(locked, nd);
>+
>+	/*
>+	 * judging by timestamps is meaningless since some filesystem uses
>+	 * CURRENT_TIME_SEC instead of CURRENT_TIME.
>+	 */
>+	/*
>+	 * NFS may stop IN_DELETE because of DCACHE_NFSFS_RENAMED.
>+	 */
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static noinline_for_stack int
>+simple_reval_dpath(struct dentry *dentry, au_gen_t sgen)
>+{
>+	int err;
>+	mode_t type;
>+	struct dentry *parent;
>+	struct inode *inode;
>+
>+	LKTRTrace("%.*s, sgen %d\n", AuDLNPair(dentry), sgen);
>+	SiMustAnyLock(dentry->d_sb);
>+	DiMustWriteLock(dentry);
>+	inode = dentry->d_inode;
>+	AuDebugOn(!inode);
>+
>+	if (au_digen(dentry) == sgen && au_iigen(inode) == sgen)
>+		return 0;
>+
>+	parent = dget_parent(dentry);
>+	di_read_lock_parent(parent, AuLock_IR);
>+	AuDebugOn(au_digen(parent) != sgen
>+		  || au_iigen(parent->d_inode) != sgen);
>+#ifdef CONFIG_AUFS_DEBUG
>+	{
>+		int i, j;
>+		struct au_dcsub_pages dpages;
>+		struct au_dpage *dpage;
>+		struct dentry **dentries;
>+
>+		err = au_dpages_init(&dpages, GFP_TEMPORARY);
>+		AuDebugOn(err);
>+		err = au_dcsub_pages_rev(&dpages, parent, /*do_include*/1, NULL,
>+					 NULL);
>+		AuDebugOn(err);
>+		for (i = dpages.ndpage - 1; !err && i >= 0; i--) {
>+			dpage = dpages.dpages + i;
>+			dentries = dpage->dentries;
>+			for (j = dpage->ndentry - 1; !err && j >= 0; j--)
>+				AuDebugOn(au_digen(dentries[j]) != sgen);
>+		}
>+		au_dpages_free(&dpages);
>+	}
>+#endif
>+	type = (inode->i_mode & S_IFMT);
>+	/* returns a number of positive dentries */
>+	err = au_refresh_hdentry(dentry, type);
>+	if (err >= 0)
>+		err = au_refresh_hinode(inode, dentry);
>+	di_read_unlock(parent, AuLock_IR);
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_reval_dpath(struct dentry *dentry, au_gen_t sgen)
>+{
>+	int err;
>+	struct dentry *d, *parent;
>+	struct inode *inode;
>+
>+	LKTRTrace("%.*s, sgen %d\n", AuDLNPair(dentry), sgen);
>+	AuDebugOn(!dentry->d_inode);
>+	DiMustWriteLock(dentry);
>+
>+	if (!au_ftest_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIRS))
>+		return simple_reval_dpath(dentry, sgen);
>+
>+	/* slow loop, keep it simple and stupid */
>+	/* cf: au_cpup_dirs() */
>+	err = 0;
>+	parent = NULL;
>+	while (au_digen(dentry) != sgen || au_iigen(dentry->d_inode) != sgen) {
>+		d = dentry;
>+		while (1) {
>+			dput(parent);
>+			parent = dget_parent(d);
>+			if (au_digen(parent) == sgen
>+			    && au_iigen(parent->d_inode) == sgen)
>+				break;
>+			d = parent;
>+		}
>+
>+		inode = d->d_inode;
>+		if (d != dentry) {
>+			//mutex_lock(&inode->i_mutex);
>+			di_write_lock_child(d);
>+		}
>+
>+		/* someone might update our dentry while we were sleeping */
>+		if (au_digen(d) != sgen || au_iigen(d->d_inode) != sgen) {
>+			di_read_lock_parent(parent, AuLock_IR);
>+			/* returns a number of positive dentries */
>+			err = au_refresh_hdentry(d, inode->i_mode & S_IFMT);
>+			//err = -1;
>+			if (err >= 0)
>+				err = au_refresh_hinode(inode, d);
>+			//err = -1;
>+			di_read_unlock(parent, AuLock_IR);
>+		}
>+
>+		if (d != dentry) {
>+			di_write_unlock(d);
>+			//mutex_unlock(&inode->i_mutex);
>+		}
>+		dput(parent);
>+		if (unlikely(err))
>+			break;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * THIS IS A BOOLEAN FUNCTION: returns 1 if valid, 0 otherwise.
>+ * nfsd passes NULL as nameidata.
>+ */
>+static int aufs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
>+{
>+	int valid, err, do_udba;
>+	struct super_block *sb;
>+	au_gen_t sgen;
>+	struct inode *inode;
>+	struct nameidata tmp_nd, *ndp;
>+
>+	LKTRTrace("dentry %.*s\n", AuDLNPair(dentry));
>+	if (nd && nd->path.dentry)
>+		LKTRTrace("nd{%.*s, 0x%x}\n",
>+			  AuDLNPair(nd->path.dentry), nd->flags);
>+	//dir case: AuDebugOn(dentry->d_parent != nd->dentry);
>+	//remove failure case:AuDebugOn(!IS_ROOT(dentry) && d_unhashed(dentry));
>+	AuDebugOn(!dentry->d_fsdata);
>+	//AuDbgDentry(dentry);
>+
>+	err = -EINVAL;
>+	inode = dentry->d_inode;
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+
>+	sgen = au_sigen(sb);
>+	if (au_digen(dentry) == sgen)
>+		di_read_lock_child(dentry, !AuLock_IR);
>+	else {
>+		AuDebugOn(IS_ROOT(dentry));
>+#ifdef ForceInotify
>+		AuDbg("UDBA or digen, %.*s\n", AuDLNPair(dentry));
>+#endif
>+		di_write_lock_child(dentry);
>+		if (inode)
>+			err = au_reval_dpath(dentry, sgen);
>+		//err = -1;
>+		di_downgrade_lock(dentry, AuLock_IR);
>+		if (unlikely(err))
>+			goto out;
>+		if (inode)
>+			ii_read_unlock(inode);
>+		AuDebugOn(au_digen(dentry) != sgen);
>+	}
>+
>+	if (inode) {
>+		if (au_iigen(inode) == sgen)
>+			ii_read_lock_child(inode);
>+		else {
>+			AuDebugOn(IS_ROOT(dentry));
>+#ifdef ForceInotify
>+			AuDbg("UDBA or survived, %.*s\n", AuDLNPair(dentry));
>+			//au_debug_on();
>+			//AuDbgInode(inode);
>+			//au_debug_off();
>+#endif
>+			ii_write_lock_child(inode);
>+			err = au_refresh_hinode(inode, dentry);
>+			ii_downgrade_lock(inode);
>+			if (unlikely(err))
>+				goto out;
>+			AuDebugOn(au_iigen(inode) != sgen);
>+		}
>+	}
>+
>+	AuDebugOn(au_digen(dentry) != sgen);
>+	AuDebugOn(inode && au_iigen(inode) != sgen);
>+	err = -EINVAL;
>+	do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE);
>+	if (do_udba && inode) {
>+		aufs_bindex_t bstart = au_ibstart(inode);
>+		if (bstart >= 0
>+		    && au_test_higen(inode, au_h_iptr(inode, bstart)))
>+			goto out;
>+	}
>+	ndp = au_dup_nd(au_sbi(sb), &tmp_nd, nd);
>+	err = h_d_revalidate(dentry, inode, ndp, do_udba);
>+	//err = -1;
>+
>+ out:
>+	au_store_fmode_exec(nd, inode);
>+
>+	if (inode)
>+		ii_read_unlock(inode);
>+	di_read_unlock(dentry, !AuLock_IR);
>+	si_read_unlock(sb);
>+	AuTraceErr(err);
>+	valid = !err;
>+	if (!valid)
>+		LKTRTrace("%.*s invalid\n", AuDLNPair(dentry));
>+	return valid;
>+}
>+
>+static void aufs_d_release(struct dentry *dentry)
>+{
>+	struct au_dinfo *dinfo;
>+	aufs_bindex_t bend, bindex;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	AuDebugOn(!d_unhashed(dentry));
>+
>+	dinfo = dentry->d_fsdata;
>+	if (unlikely(!dinfo))
>+		return;
>+
>+	/* dentry may not be revalidated */
>+	bindex = dinfo->di_bstart;
>+	if (bindex >= 0) {
>+		struct au_hdentry *p;
>+		bend = dinfo->di_bend;
>+		AuDebugOn(bend < bindex);
>+		p = dinfo->di_hdentry + bindex;
>+		while (bindex++ <= bend) {
>+			if (p->hd_dentry)
>+				au_hdput(p, /*do_free*/1);
>+			p++;
>+		}
>+	}
>+	kfree(dinfo->di_hdentry);
>+	au_cache_free_dinfo(dinfo);
>+}
>+
>+struct dentry_operations aufs_dop = {
>+	.d_revalidate	= aufs_d_revalidate,
>+	.d_release	= aufs_d_release,
>+	/* never use d_delete, especially in case of nfs server */
>+	//.d_delete	= aufs_d_delete
>+	//.d_iput		= aufs_d_iput
>+};
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/dentry.h linux-2.6.25.4-unionfs/fs/aufs/dentry.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/dentry.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/dentry.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,381 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * lookup and dentry operations
>+ *
>+ * $Id: dentry.h,v 1.4 2008/05/04 23:54:53 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_DENTRY_H__
>+#define __AUFS_DENTRY_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/namei.h>
>+#include <linux/aufs_type.h>
>+#include "misc.h"
>+#include "super.h"
>+#include "vfsub.h"
>+
>+/* nameidata open_intent */
>+enum {
>+	AuIntent_AUFS,
>+	AuIntent_BRANCH,
>+	AuIntent_Last
>+};
>+
>+struct au_hdintent {
>+	struct list_head	hdi_list;
>+	struct file		*hdi_file[AuIntent_Last];
>+};
>+
>+struct au_hdentry {
>+	struct dentry		*hd_dentry;
>+
>+#ifdef CONFIG_AUFS_BR_NFS
>+	spinlock_t		hd_lock; /* intest_list */
>+	struct list_head	*hd_intent_list;
>+#endif
>+};
>+
>+struct au_dinfo {
>+	atomic_t		di_generation;
>+
>+	struct au_rwsem		di_rwsem;
>+	aufs_bindex_t		di_bstart, di_bend, di_bwh, di_bdiropq;
>+	struct au_hdentry	*di_hdentry;
>+};
>+
>+/* nameidata extension flags */
>+#define AuNdx_DLGT	1
>+#define AuNdx_DIRPERM1	(1 << 1)
>+#define au_ftest_ndx(flags, name)	((flags) & AuNdx_##name)
>+#define au_fset_ndx(flags, name)	{ (flags) |= AuNdx_##name; }
>+#define au_fclr_ndx(flags, name)	{ (flags) &= ~AuNdx_##name; }
>+#ifndef CONFIG_AUFS_DLGT
>+#undef AuNdx_DLGT
>+#define AuNdx_DLGT	0
>+#undef AuNdx_DIRPERM1
>+#define AuNdx_DIRPERM1	0
>+#endif
>+
>+struct au_ndx {
>+	struct vfsmount *nfsmnt;
>+	unsigned int flags;
>+	struct nameidata *nd;
>+	struct au_branch *br;
>+	struct file *nd_file;
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline void au_do_h_dentry_init(struct au_hdentry *hdentry)
>+{
>+	hdentry->hd_dentry = NULL;
>+}
>+
>+#ifdef CONFIG_AUFS_BR_NFS
>+static inline void au_h_dentry_init(struct au_hdentry *hdentry)
>+{
>+	au_do_h_dentry_init(hdentry);
>+	spin_lock_init(&hdentry->hd_lock);
>+}
>+
>+static inline void au_h_dentry_init_all(struct au_hdentry *hdentry, int n)
>+{
>+	while (n--)
>+		spin_lock_init(&hdentry[n].hd_lock);
>+}
>+
>+/* br_nfs.c */
>+struct file *au_h_intent(struct dentry *dentry, aufs_bindex_t bindex,
>+			 struct file *file);
>+int au_br_nfs_h_intent(struct file *nd_file, struct dentry *dentry,
>+		       aufs_bindex_t bindex, struct nameidata *nd);
>+void au_hintent_put(struct au_hdentry *hd, int do_free);
>+int au_fake_intent(struct nameidata *nd, int perm);
>+int au_hin_after_reval(struct nameidata *nd, struct dentry *dentry,
>+		       aufs_bindex_t bindex, struct file *file);
>+struct dentry *au_lkup_hash(const char *name, struct dentry *parent, int len,
>+			    struct au_ndx *ndx);
>+#else
>+
>+static inline void au_h_dentry_init(struct au_hdentry *hdentry)
>+{
>+	au_do_h_dentry_init(hdentry);
>+}
>+
>+static inline void au_h_dentry_init_all(struct au_hdentry *hdentry, int n)
>+{
>+	/* nothing */
>+}
>+
>+static inline
>+struct file *au_h_intent(struct dentry *dentry, aufs_bindex_t bindex,
>+			 struct file *file)
>+{
>+	//return ERR_PTR(-ENOSYS);
>+	return NULL;
>+}
>+
>+static inline
>+int au_br_nfs_h_intent(struct file *nd_file, struct dentry *dentry,
>+		       aufs_bindex_t bindex, struct nameidata *nd)
>+{
>+	return 0;
>+}
>+
>+static inline void au_hintent_put(struct au_hdentry *hd, int do_free)
>+{
>+	/* empty */
>+}
>+
>+static inline int au_fake_intent(struct nameidata *nd, int perm)
>+{
>+	return 0;
>+}
>+
>+static inline
>+int au_hin_after_reval(struct nameidata *nd, struct dentry *dentry,
>+		       aufs_bindex_t bindex, struct file *file)
>+{
>+	return 0;
>+}
>+
>+#ifdef CONFIG_AUFS_DLGT
>+static inline
>+struct dentry *au_lkup_hash(const char *name, struct dentry *parent, int len,
>+			    struct au_ndx *ndx)
>+{
>+	//return ERR_PTR(-ENOSYS);
>+	return vfsub_lookup_one_len(name, parent, len);
>+}
>+#endif
>+#endif /* CONFIG_AUFS_BR_NFS */
>+
>+#ifdef CONFIG_AUFS_DLGT
>+/* dlgt.c */
>+struct dentry *au_lkup_one_dlgt(const char *name, struct dentry *parent,
>+				int len, unsigned int flags);
>+#elif defined(CONFIG_AUFS_BR_NFS)
>+/* regardelss kernel version */
>+static inline
>+struct dentry *au_lkup_one_dlgt(const char *name, struct dentry *parent,
>+				int len, unsigned int flags)
>+{
>+	return vfsub_lookup_one_len(name, parent, len);
>+}
>+#endif
>+
>+/* dentry.c */
>+extern struct dentry_operations aufs_dop;
>+#if defined(CONFIG_AUFS_BR_NFS) || defined(CONFIG_AUFS_DLGT)
>+struct dentry *au_lkup_one(const char *name, struct dentry *parent, int len,
>+			   struct au_ndx *ndx);
>+#else
>+static inline
>+struct dentry *au_lkup_one(const char *name, struct dentry *parent, int len,
>+			   struct au_ndx *ndx)
>+{
>+	//todo: ndx->nd_file = NULL;
>+	return vfsub_lookup_one_len(name, parent, len);
>+}
>+#endif
>+struct dentry *au_sio_lkup_one(const char *name, struct dentry *parent, int len,
>+			       struct au_ndx *ndx);
>+int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t bstart, mode_t type,
>+		   struct nameidata *nd);
>+int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex);
>+int au_refresh_hdentry(struct dentry *dentry, mode_t type);
>+int au_reval_dpath(struct dentry *dentry, au_gen_t sgen);
>+
>+/* dinfo.c */
>+int au_alloc_dinfo(struct dentry *dentry);
>+struct au_dinfo *au_di(struct dentry *dentry);
>+
>+void di_read_lock(struct dentry *d, int flags, unsigned int lsc);
>+void di_read_unlock(struct dentry *d, int flags);
>+void di_downgrade_lock(struct dentry *d, int flags);
>+void di_write_lock(struct dentry *d, unsigned int lsc);
>+void di_write_unlock(struct dentry *d);
>+void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir);
>+void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir);
>+void di_write_unlock2(struct dentry *d1, struct dentry *d2);
>+
>+struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex);
>+
>+aufs_bindex_t au_dbtail(struct dentry *dentry);
>+aufs_bindex_t au_dbtaildir(struct dentry *dentry);
>+
>+void au_set_dbdiropq(struct dentry *dentry, aufs_bindex_t bindex);
>+void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex,
>+		   struct dentry *h_dentry);
>+
>+void au_update_dbrange(struct dentry *dentry, int do_put_zero);
>+void au_update_dbstart(struct dentry *dentry);
>+void au_update_dbend(struct dentry *dentry);
>+int au_find_dbindex(struct dentry *dentry, struct dentry *h_dentry);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+//todo: memory barrier?
>+static inline au_gen_t au_digen(struct dentry *d)
>+{
>+	return atomic_read(&au_di(d)->di_generation);
>+}
>+
>+#ifdef CONFIG_AUFS_HINOTIFY
>+static inline au_gen_t au_digen_dec(struct dentry *d)
>+{
>+	return atomic_dec_return(&au_di(d)->di_generation);
>+}
>+#endif /* CONFIG_AUFS_HINOTIFY */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* lock subclass for dinfo */
>+enum {
>+	AuLsc_DI_CHILD,		/* child first */
>+	AuLsc_DI_CHILD2,	/* rename(2), link(2), and cpup at hinotify */
>+	AuLsc_DI_CHILD3,	/* copyup dirs */
>+	AuLsc_DI_PARENT,
>+	AuLsc_DI_PARENT2,
>+	AuLsc_DI_PARENT3
>+};
>+
>+/*
>+ * di_read_lock_child, di_write_lock_child,
>+ * di_read_lock_child2, di_write_lock_child2,
>+ * di_read_lock_child3, di_write_lock_child3,
>+ * di_read_lock_parent, di_write_lock_parent,
>+ * di_read_lock_parent2, di_write_lock_parent2,
>+ * di_read_lock_parent3, di_write_lock_parent3,
>+ */
>+#define AuReadLockFunc(name, lsc) \
>+static inline void di_read_lock_##name(struct dentry *d, int flags) \
>+{ di_read_lock(d, flags, AuLsc_DI_##lsc); }
>+
>+#define AuWriteLockFunc(name, lsc) \
>+static inline void di_write_lock_##name(struct dentry *d) \
>+{ di_write_lock(d, AuLsc_DI_##lsc); }
>+
>+#define AuRWLockFuncs(name, lsc) \
>+	AuReadLockFunc(name, lsc) \
>+	AuWriteLockFunc(name, lsc)
>+
>+AuRWLockFuncs(child, CHILD);
>+AuRWLockFuncs(child2, CHILD2);
>+AuRWLockFuncs(child3, CHILD3);
>+AuRWLockFuncs(parent, PARENT);
>+AuRWLockFuncs(parent2, PARENT2);
>+AuRWLockFuncs(parent3, PARENT3);
>+
>+#undef AuReadLockFunc
>+#undef AuWriteLockFunc
>+#undef AuRWLockFuncs
>+
>+/* to debug easier, do not make them inlined functions */
>+#define DiMustReadLock(d) do { \
>+	SiMustAnyLock((d)->d_sb); \
>+	AuRwMustReadLock(&au_di(d)->di_rwsem); \
>+} while (0)
>+
>+#define DiMustWriteLock(d) do { \
>+	SiMustAnyLock((d)->d_sb); \
>+	AuRwMustWriteLock(&au_di(d)->di_rwsem); \
>+} while (0)
>+
>+#define DiMustAnyLock(d) do { \
>+	SiMustAnyLock((d)->d_sb); \
>+	AuRwMustAnyLock(&au_di(d)->di_rwsem); \
>+} while (0)
>+
>+#define DiMustNoWaiters(d)	AuRwMustNoWaiters(&au_di(d)->di_rwsem)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline aufs_bindex_t au_dbstart(struct dentry *dentry)
>+{
>+	DiMustAnyLock(dentry);
>+	return au_di(dentry)->di_bstart;
>+}
>+
>+static inline aufs_bindex_t au_dbend(struct dentry *dentry)
>+{
>+	DiMustAnyLock(dentry);
>+	return au_di(dentry)->di_bend;
>+}
>+
>+static inline aufs_bindex_t au_dbwh(struct dentry *dentry)
>+{
>+	DiMustAnyLock(dentry);
>+	return au_di(dentry)->di_bwh;
>+}
>+
>+static inline aufs_bindex_t au_dbdiropq(struct dentry *dentry)
>+{
>+	DiMustAnyLock(dentry);
>+	AuDebugOn(dentry->d_inode
>+		  && dentry->d_inode->i_mode
>+		  && !S_ISDIR(dentry->d_inode->i_mode));
>+	return au_di(dentry)->di_bdiropq;
>+}
>+
>+// hard/soft set
>+static inline void au_set_dbstart(struct dentry *dentry, aufs_bindex_t bindex)
>+{
>+	DiMustWriteLock(dentry);
>+	AuDebugOn(au_sbend(dentry->d_sb) < bindex);
>+	/* */
>+	au_di(dentry)->di_bstart = bindex;
>+}
>+
>+static inline void au_set_dbend(struct dentry *dentry, aufs_bindex_t bindex)
>+{
>+	DiMustWriteLock(dentry);
>+	AuDebugOn(au_sbend(dentry->d_sb) < bindex
>+		  || bindex < au_dbstart(dentry));
>+	au_di(dentry)->di_bend = bindex;
>+}
>+
>+static inline void au_set_dbwh(struct dentry *dentry, aufs_bindex_t bindex)
>+{
>+	DiMustWriteLock(dentry);
>+	AuDebugOn(au_sbend(dentry->d_sb) < bindex);
>+	/* dbwh can be outside of bstart - bend range */
>+	au_di(dentry)->di_bwh = bindex;
>+}
>+
>+static inline void au_hdput(struct au_hdentry *hd, int do_free)
>+{
>+	au_hintent_put(hd, do_free);
>+	dput(hd->hd_dentry);
>+}
>+
>+static inline void au_update_digen(struct dentry *dentry)
>+{
>+	//DiMustWriteLock(dentry);
>+	AuDebugOn(!dentry->d_sb);
>+	atomic_set(&au_di(dentry)->di_generation, au_sigen(dentry->d_sb));
>+	//smp_mb(); /* atomic_set */
>+}
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_DENTRY_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/dinfo.c linux-2.6.25.4-unionfs/fs/aufs/dinfo.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/dinfo.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/dinfo.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,412 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * dentry private data
>+ *
>+ * $Id: dinfo.c,v 1.3 2008/04/28 03:04:23 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+int au_alloc_dinfo(struct dentry *dentry)
>+{
>+	struct au_dinfo *dinfo;
>+	struct super_block *sb;
>+	int nbr;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	AuDebugOn(dentry->d_fsdata);
>+
>+	dinfo = au_cache_alloc_dinfo();
>+	//if (LktrCond) {au_cache_free_dinfo(dinfo); dinfo = NULL;}
>+	if (dinfo) {
>+		sb = dentry->d_sb;
>+		nbr = au_sbend(sb) + 1;
>+		if (unlikely(nbr <= 0))
>+			nbr = 1;
>+		dinfo->di_hdentry = kcalloc(nbr, sizeof(*dinfo->di_hdentry),
>+					    GFP_KERNEL);
>+		//if (LktrCond)
>+		//{kfree(dinfo->di_hdentry); dinfo->di_hdentry = NULL;}
>+		if (dinfo->di_hdentry) {
>+			au_h_dentry_init_all(dinfo->di_hdentry, nbr);
>+			atomic_set(&dinfo->di_generation, au_sigen(sb));
>+			//smp_mb(); /* atomic_set */
>+			au_rw_init_wlock_nested(&dinfo->di_rwsem,
>+						AuLsc_DI_PARENT);
>+			dinfo->di_bstart = -1;
>+			dinfo->di_bend = -1;
>+			dinfo->di_bwh = -1;
>+			dinfo->di_bdiropq = -1;
>+
>+			dentry->d_fsdata = dinfo;
>+			dentry->d_op = &aufs_dop;
>+			return 0; /* success */
>+		}
>+		au_cache_free_dinfo(dinfo);
>+	}
>+	AuTraceErr(-ENOMEM);
>+	return -ENOMEM;
>+}
>+
>+struct au_dinfo *au_di(struct dentry *dentry)
>+{
>+	struct au_dinfo *dinfo = dentry->d_fsdata;
>+	AuDebugOn(!dinfo
>+		 || !dinfo->di_hdentry
>+		 /* || au_sbi(dentry->d_sb)->si_bend < dinfo->di_bend */
>+		 || dinfo->di_bend < dinfo->di_bstart
>+		 /* dbwh can be outside of this range */
>+		 || (0 <= dinfo->di_bdiropq
>+		     && (dinfo->di_bdiropq < dinfo->di_bstart
>+			 /* || dinfo->di_bend < dinfo->di_bdiropq */))
>+		);
>+	return dinfo;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static void do_ii_write_lock(struct inode *inode, unsigned int lsc)
>+{
>+	switch (lsc) {
>+	case AuLsc_DI_CHILD:
>+		ii_write_lock_child(inode);
>+		break;
>+	case AuLsc_DI_CHILD2:
>+		ii_write_lock_child2(inode);
>+		break;
>+	case AuLsc_DI_CHILD3:
>+		ii_write_lock_child3(inode);
>+		break;
>+	case AuLsc_DI_PARENT:
>+		//AuDebugOn(!S_ISDIR(inode->i_mode));
>+		ii_write_lock_parent(inode);
>+		break;
>+	case AuLsc_DI_PARENT2:
>+		//AuDebugOn(!S_ISDIR(inode->i_mode));
>+		ii_write_lock_parent2(inode);
>+		break;
>+	case AuLsc_DI_PARENT3:
>+		//AuDebugOn(!S_ISDIR(inode->i_mode));
>+		ii_write_lock_parent3(inode);
>+		break;
>+	default:
>+		BUG();
>+	}
>+}
>+
>+static void do_ii_read_lock(struct inode *inode, unsigned int lsc)
>+{
>+	switch (lsc) {
>+	case AuLsc_DI_CHILD:
>+		ii_read_lock_child(inode);
>+		break;
>+	case AuLsc_DI_CHILD2:
>+		ii_read_lock_child2(inode);
>+		break;
>+	case AuLsc_DI_CHILD3:
>+		ii_read_lock_child3(inode);
>+		break;
>+	case AuLsc_DI_PARENT:
>+		//AuDebugOn(!S_ISDIR(inode->i_mode));
>+		ii_read_lock_parent(inode);
>+		break;
>+	case AuLsc_DI_PARENT2:
>+		//AuDebugOn(!S_ISDIR(inode->i_mode));
>+		ii_read_lock_parent2(inode);
>+		break;
>+	case AuLsc_DI_PARENT3:
>+		//AuDebugOn(!S_ISDIR(inode->i_mode));
>+		ii_read_lock_parent3(inode);
>+		break;
>+	default:
>+		BUG();
>+	}
>+}
>+
>+void di_read_lock(struct dentry *d, int flags, unsigned int lsc)
>+{
>+	SiMustAnyLock(d->d_sb);
>+	// todo: always nested?
>+	au_rw_read_lock_nested(&au_di(d)->di_rwsem, lsc);
>+	if (d->d_inode) {
>+		if (au_ftest_lock(flags, IW))
>+			do_ii_write_lock(d->d_inode, lsc);
>+		else if (au_ftest_lock(flags, IR))
>+			do_ii_read_lock(d->d_inode, lsc);
>+	}
>+}
>+
>+void di_read_unlock(struct dentry *d, int flags)
>+{
>+	SiMustAnyLock(d->d_sb);
>+	if (d->d_inode) {
>+		if (au_ftest_lock(flags, IW))
>+			ii_write_unlock(d->d_inode);
>+		else if (au_ftest_lock(flags, IR))
>+			ii_read_unlock(d->d_inode);
>+	}
>+	au_rw_read_unlock(&au_di(d)->di_rwsem);
>+}
>+
>+void di_downgrade_lock(struct dentry *d, int flags)
>+{
>+	SiMustAnyLock(d->d_sb);
>+	au_rw_dgrade_lock(&au_di(d)->di_rwsem);
>+	if (d->d_inode && au_ftest_lock(flags, IR))
>+		ii_downgrade_lock(d->d_inode);
>+}
>+
>+void di_write_lock(struct dentry *d, unsigned int lsc)
>+{
>+	SiMustAnyLock(d->d_sb);
>+	// todo: always nested?
>+	au_rw_write_lock_nested(&au_di(d)->di_rwsem, lsc);
>+	if (d->d_inode)
>+		do_ii_write_lock(d->d_inode, lsc);
>+}
>+
>+void di_write_unlock(struct dentry *d)
>+{
>+	SiMustAnyLock(d->d_sb);
>+	if (d->d_inode)
>+		ii_write_unlock(d->d_inode);
>+	au_rw_write_unlock(&au_di(d)->di_rwsem);
>+}
>+
>+void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir)
>+{
>+	AuTraceEnter();
>+	AuDebugOn(d1 == d2
>+		  || d1->d_inode == d2->d_inode
>+		  || d1->d_sb != d2->d_sb);
>+
>+	if (isdir && au_test_subdir(d1, d2)) {
>+		di_write_lock_child(d1);
>+		di_write_lock_child2(d2);
>+	} else {
>+		/* there should be no races */
>+		di_write_lock_child(d2);
>+		di_write_lock_child2(d1);
>+	}
>+}
>+
>+void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir)
>+{
>+	AuTraceEnter();
>+	AuDebugOn(d1 == d2
>+		  || d1->d_inode == d2->d_inode
>+		  || d1->d_sb != d2->d_sb);
>+
>+	if (isdir && au_test_subdir(d1, d2)) {
>+		di_write_lock_parent(d1);
>+		di_write_lock_parent2(d2);
>+	} else {
>+		/* there should be no races */
>+		di_write_lock_parent(d2);
>+		di_write_lock_parent2(d1);
>+	}
>+}
>+
>+void di_write_unlock2(struct dentry *d1, struct dentry *d2)
>+{
>+	di_write_unlock(d1);
>+	if (d1->d_inode == d2->d_inode)
>+		au_rw_write_unlock(&au_di(d2)->di_rwsem);
>+	else
>+		di_write_unlock(d2);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex)
>+{
>+	struct dentry *d;
>+
>+	DiMustAnyLock(dentry);
>+	if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry))
>+		return NULL;
>+	AuDebugOn(bindex < 0
>+		  /* || bindex > au_sbend(dentry->d_sb) */);
>+	d = au_di(dentry)->di_hdentry[0 + bindex].hd_dentry;
>+	AuDebugOn(d && (atomic_read(&d->d_count) <= 0));
>+	return d;
>+}
>+
>+aufs_bindex_t au_dbtail(struct dentry *dentry)
>+{
>+	aufs_bindex_t bend, bwh;
>+
>+	bend = au_dbend(dentry);
>+	if (0 <= bend) {
>+		bwh = au_dbwh(dentry);
>+		//AuDebugOn(bend < bwh);
>+		if (!bwh)
>+			return bwh;
>+		if (0 < bwh && bwh < bend)
>+			return bwh - 1;
>+	}
>+	return bend;
>+}
>+
>+aufs_bindex_t au_dbtaildir(struct dentry *dentry)
>+{
>+	aufs_bindex_t bend, bopq;
>+
>+	AuDebugOn(dentry->d_inode
>+		  && dentry->d_inode->i_mode
>+		  && !S_ISDIR(dentry->d_inode->i_mode));
>+
>+	bend = au_dbtail(dentry);
>+	if (0 <= bend) {
>+		bopq = au_dbdiropq(dentry);
>+		AuDebugOn(bend < bopq);
>+		if (0 <= bopq && bopq < bend)
>+			bend = bopq;
>+	}
>+	return bend;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void au_set_dbdiropq(struct dentry *dentry, aufs_bindex_t bindex)
>+{
>+	DiMustWriteLock(dentry);
>+	AuDebugOn(au_sbend(dentry->d_sb) < bindex);
>+	AuDebugOn((bindex >= 0
>+		   && (bindex < au_dbstart(dentry)
>+		       || au_dbend(dentry) < bindex))
>+		  || (dentry->d_inode
>+		      && dentry->d_inode->i_mode
>+		      && !S_ISDIR(dentry->d_inode->i_mode)));
>+	au_di(dentry)->di_bdiropq = bindex;
>+}
>+
>+void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex,
>+		   struct dentry *h_dentry)
>+{
>+	struct au_hdentry *hd = au_di(dentry)->di_hdentry + bindex;
>+	DiMustWriteLock(dentry);
>+	AuDebugOn(bindex < au_di(dentry)->di_bstart
>+		  || bindex > au_di(dentry)->di_bend
>+		  || (h_dentry && atomic_read(&h_dentry->d_count) <= 0)
>+		  || (h_dentry && hd->hd_dentry)
>+		);
>+	if (hd->hd_dentry)
>+		au_hdput(hd, /*do_free*/0);
>+	hd->hd_dentry = h_dentry;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void au_update_dbrange(struct dentry *dentry, int do_put_zero)
>+{
>+	struct au_dinfo *dinfo;
>+	aufs_bindex_t bindex;
>+	struct dentry *h_d;
>+
>+	LKTRTrace("%.*s, %d\n", AuDLNPair(dentry), do_put_zero);
>+	DiMustWriteLock(dentry);
>+
>+	dinfo = au_di(dentry);
>+	if (unlikely(!dinfo) || dinfo->di_bstart < 0)
>+		return;
>+
>+	if (do_put_zero) {
>+		for (bindex = dinfo->di_bstart; bindex <= dinfo->di_bend;
>+		     bindex++) {
>+			h_d = dinfo->di_hdentry[0 + bindex].hd_dentry;
>+			if (h_d && !h_d->d_inode)
>+				au_set_h_dptr(dentry, bindex, NULL);
>+		}
>+	}
>+
>+	dinfo->di_bstart = -1;
>+	while (++dinfo->di_bstart <= dinfo->di_bend)
>+		if (dinfo->di_hdentry[0 + dinfo->di_bstart].hd_dentry)
>+			break;
>+	if (dinfo->di_bstart > dinfo->di_bend) {
>+		dinfo->di_bstart = -1;
>+		dinfo->di_bend = -1;
>+		return;
>+	}
>+
>+	dinfo->di_bend++;
>+	while (0 <= --dinfo->di_bend)
>+		if (dinfo->di_hdentry[0 + dinfo->di_bend].hd_dentry)
>+			break;
>+	AuDebugOn(dinfo->di_bstart > dinfo->di_bend || dinfo->di_bend < 0);
>+}
>+
>+void au_update_dbstart(struct dentry *dentry)
>+{
>+	aufs_bindex_t bindex,
>+		bstart = au_dbstart(dentry),
>+		bend = au_dbend(dentry);
>+	struct dentry *h_dentry;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	DiMustWriteLock(dentry);
>+
>+	for (bindex = bstart; bindex <= bend; bindex++) {
>+		h_dentry = au_h_dptr(dentry, bindex);
>+		if (!h_dentry)
>+			continue;
>+		if (h_dentry->d_inode) {
>+			au_set_dbstart(dentry, bindex);
>+			return;
>+		}
>+		au_set_h_dptr(dentry, bindex, NULL);
>+	}
>+	//au_set_dbstart(dentry, -1);
>+	//au_set_dbend(dentry, -1);
>+}
>+
>+void au_update_dbend(struct dentry *dentry)
>+{
>+	aufs_bindex_t bindex,
>+		bstart = au_dbstart(dentry),
>+		bend = au_dbend(dentry);
>+	struct dentry *h_dentry;
>+
>+	DiMustWriteLock(dentry);
>+	for (bindex = bend; bindex <= bstart; bindex--) {
>+		h_dentry = au_h_dptr(dentry, bindex);
>+		if (!h_dentry)
>+			continue;
>+		if (h_dentry->d_inode) {
>+			au_set_dbend(dentry, bindex);
>+			return;
>+		}
>+		au_set_h_dptr(dentry, bindex, NULL);
>+	}
>+	//au_set_dbstart(dentry, -1);
>+	//au_set_dbend(dentry, -1);
>+}
>+
>+int au_find_dbindex(struct dentry *dentry, struct dentry *h_dentry)
>+{
>+	aufs_bindex_t bindex, bend;
>+
>+	bend = au_dbend(dentry);
>+	for (bindex = au_dbstart(dentry); bindex <= bend; bindex++)
>+		if (au_h_dptr(dentry, bindex) == h_dentry)
>+			return bindex;
>+	return -1;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/dir.c linux-2.6.25.4-unionfs/fs/aufs/dir.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/dir.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/dir.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,553 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * directory operations
>+ *
>+ * $Id: dir.c,v 1.4 2008/05/12 00:27:58 sfjro Exp $
>+ */
>+
>+#include <linux/fs_stack.h>
>+#include "aufs.h"
>+
>+static int reopen_dir(struct file *file)
>+{
>+	int err;
>+	struct dentry *dentry, *h_dentry;
>+	aufs_bindex_t bindex, btail, bstart;
>+	struct file *h_file;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	AuDebugOn(!S_ISDIR(dentry->d_inode->i_mode));
>+
>+	/* open all hidden dirs */
>+	bstart = au_dbstart(dentry);
>+	for (bindex = au_fbstart(file); bindex < bstart; bindex++)
>+		au_set_h_fptr(file, bindex, NULL);
>+	au_set_fbstart(file, bstart);
>+	btail = au_dbtaildir(dentry);
>+	for (bindex = au_fbend(file); btail < bindex; bindex--)
>+		au_set_h_fptr(file, bindex, NULL);
>+	au_set_fbend(file, btail);
>+	for (bindex = bstart; bindex <= btail; bindex++) {
>+		h_dentry = au_h_dptr(dentry, bindex);
>+		if (!h_dentry)
>+			continue;
>+		h_file = au_h_fptr(file, bindex);
>+		if (h_file) {
>+			AuDebugOn(h_file->f_dentry != h_dentry);
>+			continue;
>+		}
>+
>+		h_file = au_h_open(dentry, bindex, file->f_flags, file);
>+		// unavailable
>+		//if (LktrCond) {fput(h_file);
>+		//au_br_put(au_sbr(dentry->d_sb, bindex));h_file=ERR_PTR(-1);}
>+		err = PTR_ERR(h_file);
>+		if (IS_ERR(h_file))
>+			goto out; // close all?
>+		//cpup_file_flags(h_file, file);
>+		au_set_h_fptr(file, bindex, h_file);
>+	}
>+	au_update_figen(file);
>+	//file->f_ra = h_file->f_ra; //??
>+	err = 0;
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int do_open_dir(struct file *file, int flags)
>+{
>+	int err;
>+	aufs_bindex_t bindex, btail;
>+	struct dentry *dentry, *h_dentry;
>+	struct file *h_file;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, 0x%x\n", AuDLNPair(dentry), flags);
>+	AuDebugOn(!dentry->d_inode || !S_ISDIR(dentry->d_inode->i_mode));
>+
>+	err = 0;
>+	au_set_fvdir_cache(file, NULL);
>+	file->f_version = dentry->d_inode->i_version;
>+	bindex = au_dbstart(dentry);
>+	au_set_fbstart(file, bindex);
>+	btail = au_dbtaildir(dentry);
>+	au_set_fbend(file, btail);
>+	for (; !err && bindex <= btail; bindex++) {
>+		h_dentry = au_h_dptr(dentry, bindex);
>+		if (!h_dentry)
>+			continue;
>+
>+		h_file = au_h_open(dentry, bindex, flags, file);
>+		//if (LktrCond) {fput(h_file);
>+		//au_br_put(au_sbr(dentry->d_sb, bindex));h_file=ERR_PTR(-1);}
>+		if (!IS_ERR(h_file)) {
>+			au_set_h_fptr(file, bindex, h_file);
>+			continue;
>+		}
>+		err = PTR_ERR(h_file);
>+	}
>+	au_update_figen(file);
>+	//file->f_ra = h_file->f_ra; //??
>+	if (!err)
>+		return 0; /* success */
>+
>+	/* close all */
>+	for (bindex = au_fbstart(file); !err && bindex <= btail; bindex++)
>+		au_set_h_fptr(file, bindex, NULL);
>+	au_set_fbstart(file, -1);
>+	au_set_fbend(file, -1);
>+	return err;
>+}
>+
>+static int aufs_open_dir(struct inode *inode, struct file *file)
>+{
>+	return au_do_open(inode, file, do_open_dir);
>+}
>+
>+static int aufs_release_dir(struct inode *inode, struct file *file)
>+{
>+	struct au_vdir *vdir_cache;
>+	struct super_block *sb;
>+
>+	LKTRTrace("i%lu, %.*s\n", inode->i_ino, AuDLNPair(file->f_dentry));
>+
>+	sb = file->f_dentry->d_sb;
>+	si_noflush_read_lock(sb);
>+	fi_write_lock(file);
>+	vdir_cache = au_fvdir_cache(file);
>+	if (vdir_cache)
>+		au_vdir_free(vdir_cache);
>+	fi_write_unlock(file);
>+	au_finfo_fin(file);
>+	si_read_unlock(sb);
>+	return 0;
>+}
>+
>+static int fsync_dir(struct dentry *dentry, int datasync)
>+{
>+	int err;
>+	struct inode *inode;
>+	struct super_block *sb;
>+	aufs_bindex_t bend, bindex;
>+
>+	LKTRTrace("%.*s, %d\n", AuDLNPair(dentry), datasync);
>+	DiMustAnyLock(dentry);
>+	sb = dentry->d_sb;
>+	SiMustAnyLock(sb);
>+	inode = dentry->d_inode;
>+	IMustLock(inode);
>+	IiMustAnyLock(inode);
>+
>+	err = 0;
>+	bend = au_dbend(dentry);
>+	for (bindex = au_dbstart(dentry); !err && bindex <= bend; bindex++) {
>+		struct dentry *h_dentry;
>+		struct inode *h_inode;
>+		struct file_operations *fop;
>+
>+		if (au_test_ro(sb, bindex, inode))
>+			continue;
>+		h_dentry = au_h_dptr(dentry, bindex);
>+		if (!h_dentry)
>+			continue;
>+		h_inode = h_dentry->d_inode;
>+		if (!h_inode)
>+			continue;
>+
>+		/* cf. fs/nsfd/vfs.c and fs/nfsd/nfs4recover.c */
>+		//au_hdir_lock(h_inode, inode, bindex);
>+		mutex_lock(&h_inode->i_mutex);
>+		fop = (void *)h_inode->i_fop;
>+		err = filemap_fdatawrite(h_inode->i_mapping);
>+		if (!err && fop && fop->fsync)
>+			err = fop->fsync(NULL, h_dentry, datasync);
>+		if (!err)
>+			err = filemap_fdatawrite(h_inode->i_mapping);
>+		if (!err)
>+			au_update_fuse_h_inode(NULL, h_dentry); /*ignore*/
>+		//au_hdir_unlock(h_inode, inode, bindex);
>+		mutex_unlock(&h_inode->i_mutex);
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * @file may be NULL
>+ */
>+static int aufs_fsync_dir(struct file *file, struct dentry *dentry,
>+			  int datasync)
>+{
>+	int err;
>+	struct inode *inode;
>+	struct file *h_file;
>+	struct super_block *sb;
>+	aufs_bindex_t bend, bindex;
>+
>+	LKTRTrace("%.*s, %d\n", AuDLNPair(dentry), datasync);
>+	inode = dentry->d_inode;
>+	IMustLock(inode);
>+
>+	err = 0;
>+	sb = dentry->d_sb;
>+	si_noflush_read_lock(sb);
>+	if (file) {
>+		err = au_reval_and_lock_finfo(file, reopen_dir, /*wlock*/1,
>+					      /*locked*/1);
>+		//err = -1;
>+		if (unlikely(err))
>+			goto out;
>+	} else
>+		di_read_lock_child(dentry, !AuLock_IW);
>+
>+	ii_write_lock_child(inode);
>+	if (file) {
>+		bend = au_fbend(file);
>+		for (bindex = au_fbstart(file); !err && bindex <= bend;
>+		     bindex++) {
>+			h_file = au_h_fptr(file, bindex);
>+			if (!h_file || au_test_ro(sb, bindex, inode))
>+				continue;
>+
>+			err = -EINVAL;
>+			if (h_file->f_op && h_file->f_op->fsync) {
>+				// todo: try do_fsync() in fs/sync.c
>+				mutex_lock(&h_file->f_mapping->host->i_mutex);
>+				err = h_file->f_op->fsync
>+					(h_file, h_file->f_dentry, datasync);
>+				//err = -1;
>+				if (!err)
>+					au_update_fuse_h_inode
>+						(h_file->f_vfsmnt,
>+						 h_file->f_dentry);
>+				/*ignore*/
>+				mutex_unlock(&h_file->f_mapping->host->i_mutex);
>+			}
>+		}
>+	} else
>+		err = fsync_dir(dentry, datasync);
>+	au_cpup_attr_timesizes(inode);
>+	ii_write_unlock(inode);
>+	if (file)
>+		fi_write_unlock(file);
>+	else
>+		di_read_unlock(dentry, !AuLock_IW);
>+
>+ out:
>+	si_read_unlock(sb);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int aufs_readdir(struct file *file, void *dirent, filldir_t filldir)
>+{
>+	int err;
>+	struct dentry *dentry;
>+	struct inode *inode;
>+	struct super_block *sb;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, pos %Ld\n", AuDLNPair(dentry), file->f_pos);
>+	inode = dentry->d_inode;
>+	IMustLock(inode);
>+
>+	au_nfsd_lockdep_off();
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	err = au_reval_and_lock_finfo(file, reopen_dir, /*wlock*/1,
>+				      /*locked*/1);
>+	if (unlikely(err))
>+		goto out;
>+
>+	ii_write_lock_child(inode);
>+	err = au_vdir_init(file);
>+	if (unlikely(err)) {
>+		ii_write_unlock(inode);
>+		goto out_unlock;
>+	}
>+	//DbgVdir(au_fvdir_cache(file));// goto out_unlock;
>+
>+	/* nfsd filldir calls lookup_one_len(). */
>+	ii_downgrade_lock(inode);
>+	err = au_vdir_fill_de(file, dirent, filldir);
>+	//DbgVdir(au_fvdir_cache(file));// goto out_unlock;
>+
>+	fsstack_copy_attr_atime(inode, au_h_iptr(inode, au_ibstart(inode)));
>+	ii_read_unlock(inode);
>+
>+ out_unlock:
>+	fi_write_unlock(file);
>+ out:
>+	si_read_unlock(sb);
>+	au_nfsd_lockdep_on();
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#define AuTestEmpty_WHONLY	1
>+#define AuTestEmpty_DLGT	(1 << 1)
>+#define AuTestEmpty_DIRPERM1	(1 << 2)
>+#define AuTestEmpty_CALLED	(1 << 3)
>+#define AuTestEmpty_SHWH	(1 << 4)
>+#define au_ftest_testempty(flags, name)	((flags) & AuTestEmpty_##name)
>+#define au_fset_testempty(flags, name)	{ (flags) |= AuTestEmpty_##name; }
>+#define au_fclr_testempty(flags, name)	{ (flags) &= ~AuTestEmpty_##name; }
>+#ifndef CONFIG_AUFS_DLGT
>+#undef AuTestEmpty_DLGT
>+#define AuTestEmpty_DLGT	0
>+#undef AuTestEmpty_DIRPERM1
>+#define AuTestEmpty_DIRPERM1	0
>+#endif
>+#ifndef CONFIG_AUFS_SHWH
>+#undef AuTestEmpty_SHWH
>+#define AuTestEmpty_SHWH	0
>+#endif
>+
>+struct test_empty_arg {
>+	struct au_nhash *whlist;
>+	unsigned int flags;
>+	int err;
>+	aufs_bindex_t bindex;
>+};
>+
>+static int test_empty_cb(void *__arg, const char *__name, int namelen,
>+			 loff_t offset, u64 ino, unsigned int d_type)
>+{
>+	struct test_empty_arg *arg = __arg;
>+	char *name = (void *)__name;
>+
>+	LKTRTrace("%.*s\n", namelen, name);
>+
>+	arg->err = 0;
>+	au_fset_testempty(arg->flags, CALLED);
>+	//smp_mb();
>+	if (name[0] == '.'
>+	    && (namelen == 1 || (name[1] == '.' && namelen == 2)))
>+		return 0; /* success */
>+
>+	if (namelen <= AUFS_WH_PFX_LEN
>+	    || memcmp(name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
>+		if (au_ftest_testempty(arg->flags, WHONLY)
>+		    && !au_nhash_test_known_wh(arg->whlist, name, namelen))
>+			arg->err = -ENOTEMPTY;
>+		goto out;
>+	}
>+
>+	name += AUFS_WH_PFX_LEN;
>+	namelen -= AUFS_WH_PFX_LEN;
>+	if (!au_nhash_test_known_wh(arg->whlist, name, namelen))
>+		arg->err = au_nhash_append_wh
>+			(arg->whlist, name, namelen, ino, d_type, arg->bindex,
>+			 au_ftest_testempty(arg->flags, SHWH));
>+
>+ out:
>+	//smp_mb();
>+	AuTraceErr(arg->err);
>+	return arg->err;
>+}
>+
>+static int do_test_empty(struct dentry *dentry, struct test_empty_arg *arg)
>+{
>+	int err, dlgt;
>+	struct file *h_file;
>+
>+	LKTRTrace("%.*s, {%p, 0x%x, %d}\n",
>+		  AuDLNPair(dentry), arg->whlist, arg->flags, arg->bindex);
>+
>+	h_file = au_h_open(dentry, arg->bindex,
>+			   O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_LARGEFILE,
>+			   /*file*/NULL);
>+	err = PTR_ERR(h_file);
>+	if (IS_ERR(h_file))
>+		goto out;
>+	err = 0;
>+	if (unlikely(au_opt_test(au_mntflags(dentry->d_sb), UDBA_INOTIFY)
>+		     && !h_file->f_dentry->d_inode->i_nlink))
>+		goto out_put;
>+
>+	dlgt = au_ftest_testempty(arg->flags, DLGT);
>+	//h_file->f_pos = 0;
>+	do {
>+		arg->err = 0;
>+		au_fclr_testempty(arg->flags, CALLED);
>+		//smp_mb();
>+		err = vfsub_readdir(h_file, test_empty_cb, arg, dlgt);
>+		if (err >= 0)
>+			err = arg->err;
>+	} while (!err && au_ftest_testempty(arg->flags, CALLED));
>+
>+ out_put:
>+	fput(h_file);
>+	au_sbr_put(dentry->d_sb, arg->bindex);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+struct do_test_empty_args {
>+	int *errp;
>+	struct dentry *dentry;
>+	struct test_empty_arg *arg;
>+};
>+
>+static void call_do_test_empty(void *args)
>+{
>+	struct do_test_empty_args *a = args;
>+	*a->errp = do_test_empty(a->dentry, a->arg);
>+}
>+
>+static int sio_test_empty(struct dentry *dentry, struct test_empty_arg *arg)
>+{
>+	int err, wkq_err;
>+	struct dentry *h_dentry;
>+	struct inode *h_inode;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	h_dentry = au_h_dptr(dentry, arg->bindex);
>+	AuDebugOn(!h_dentry);
>+	h_inode = h_dentry->d_inode;
>+	AuDebugOn(!h_inode || !S_ISDIR(h_inode->i_mode));
>+
>+	mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
>+	err = au_test_h_perm_sio(h_inode, MAY_EXEC | MAY_READ,
>+				 au_opt_test_dlgt(au_mntflags(dentry->d_sb)));
>+	mutex_unlock(&h_inode->i_mutex);
>+	if (!err)
>+		err = do_test_empty(dentry, arg);
>+	else {
>+		struct do_test_empty_args args = {
>+			.errp	= &err,
>+			.dentry	= dentry,
>+			.arg	= arg
>+		};
>+		unsigned int flags = arg->flags;
>+		au_fclr_testempty(arg->flags, DLGT);
>+		au_fclr_testempty(arg->flags, DIRPERM1);
>+		wkq_err = au_wkq_wait(call_do_test_empty, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		arg->flags = flags;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_test_empty_lower(struct dentry *dentry)
>+{
>+	int err;
>+	struct inode *inode;
>+	struct test_empty_arg arg;
>+	struct au_nhash *whlist;
>+	aufs_bindex_t bindex, bstart, btail;
>+	unsigned int mnt_flags;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	inode = dentry->d_inode;
>+	AuDebugOn(!inode || !S_ISDIR(inode->i_mode));
>+
>+	whlist = au_nhash_new(GFP_TEMPORARY);
>+	err = PTR_ERR(whlist);
>+	if (IS_ERR(whlist))
>+		goto out;
>+
>+	bstart = au_dbstart(dentry);
>+	mnt_flags = au_mntflags(dentry->d_sb);
>+	arg.whlist = whlist;
>+	arg.flags = 0;
>+	if (unlikely(au_opt_test_dlgt(mnt_flags)))
>+		au_fset_testempty(arg.flags, DLGT);
>+	if (unlikely(au_opt_test(mnt_flags, SHWH)))
>+		au_fset_testempty(arg.flags, SHWH);
>+	arg.bindex = bstart;
>+	err = do_test_empty(dentry, &arg);
>+	if (unlikely(err))
>+		goto out_whlist;
>+
>+	au_fset_testempty(arg.flags, WHONLY);
>+	if (unlikely(au_opt_test_dirperm1(mnt_flags)))
>+		au_fset_testempty(arg.flags, DIRPERM1);
>+	btail = au_dbtaildir(dentry);
>+	for (bindex = bstart + 1; !err && bindex <= btail; bindex++) {
>+		struct dentry *h_dentry;
>+		h_dentry = au_h_dptr(dentry, bindex);
>+		if (h_dentry && h_dentry->d_inode) {
>+			AuDebugOn(!S_ISDIR(h_dentry->d_inode->i_mode));
>+			arg.bindex = bindex;
>+			err = do_test_empty(dentry, &arg);
>+		}
>+	}
>+
>+ out_whlist:
>+	au_nhash_del(whlist);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_test_empty(struct dentry *dentry, struct au_nhash *whlist)
>+{
>+	int err;
>+	struct inode *inode;
>+	struct test_empty_arg arg;
>+	aufs_bindex_t bindex, btail;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	inode = dentry->d_inode;
>+	AuDebugOn(!inode || !S_ISDIR(inode->i_mode));
>+
>+	err = 0;
>+	arg.whlist = whlist;
>+	arg.flags = AuTestEmpty_WHONLY;
>+	if (unlikely(au_opt_test(au_mntflags(dentry->d_sb), SHWH)))
>+		au_fset_testempty(arg.flags, SHWH);
>+	btail = au_dbtaildir(dentry);
>+	for (bindex = au_dbstart(dentry); !err && bindex <= btail; bindex++) {
>+		struct dentry *h_dentry;
>+		h_dentry = au_h_dptr(dentry, bindex);
>+		if (h_dentry && h_dentry->d_inode) {
>+			AuDebugOn(!S_ISDIR(h_dentry->d_inode->i_mode));
>+			arg.bindex = bindex;
>+			err = sio_test_empty(dentry, &arg);
>+		}
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct file_operations aufs_dir_fop = {
>+	.read		= generic_read_dir,
>+	.readdir	= aufs_readdir,
>+	.open		= aufs_open_dir,
>+	.release	= aufs_release_dir,
>+	.flush		= aufs_flush,
>+	.fsync		= aufs_fsync_dir,
>+};
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/dir.h linux-2.6.25.4-unionfs/fs/aufs/dir.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/dir.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/dir.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,146 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * directory operations
>+ *
>+ * $Id: dir.h,v 1.2 2008/04/21 01:34:26 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_DIR_H__
>+#define __AUFS_DIR_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/aufs_type.h>
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* need to be faster and smaller */
>+
>+#define AuSize_DEBLK	512 // todo: changeable
>+#define AuSize_NHASH	32 // todo: changeable
>+#if AuSize_DEBLK < NAME_MAX || PAGE_SIZE < AuSize_DEBLK
>+#error invalid size AuSize_DEBLK
>+#endif
>+
>+typedef char au_vdir_deblk_t[AuSize_DEBLK];
>+
>+struct au_nhash {
>+	struct hlist_head heads[AuSize_NHASH];
>+};
>+
>+struct au_vdir_destr {
>+	unsigned char	len;
>+	char		name[0];
>+} __packed;
>+
>+struct au_vdir_dehstr {
>+	struct hlist_node	hash;
>+	struct au_vdir_destr	*str;
>+};
>+
>+struct au_vdir_de {
>+	ino_t			de_ino;
>+	unsigned char		de_type;
>+	/* caution: packed */
>+	struct au_vdir_destr	de_str;
>+} __packed;
>+
>+struct au_vdir_wh {
>+	struct hlist_node	wh_hash;
>+	aufs_bindex_t		wh_bindex;
>+#ifdef CONFIG_AUFS_SHWH
>+	ino_t			wh_ino;
>+	unsigned char		wh_type;
>+	/* caution: packed */
>+#endif
>+	struct au_vdir_destr	wh_str;
>+} __packed;
>+
>+union au_vdir_deblk_p {
>+	unsigned char		*p;
>+	au_vdir_deblk_t		*deblk;
>+	struct au_vdir_de	*de;
>+};
>+
>+struct au_vdir {
>+	au_vdir_deblk_t	**vd_deblk;
>+	int		vd_nblk;
>+	struct {
>+		int			i;
>+		union au_vdir_deblk_p	p;
>+	} vd_last;
>+
>+	unsigned long	vd_version;
>+	unsigned long	vd_jiffy;
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* dir.c */
>+extern struct file_operations aufs_dir_fop;
>+int au_test_empty_lower(struct dentry *dentry);
>+int au_test_empty(struct dentry *dentry, struct au_nhash *whlist);
>+
>+/* vdir.c */
>+struct au_nhash *au_nhash_new(gfp_t gfp);
>+void au_nhash_del(struct au_nhash *nhash);
>+void au_nhash_init(struct au_nhash *nhash);
>+void au_nhash_move(struct au_nhash *dst, struct au_nhash *src);
>+void au_nhash_fin(struct au_nhash *nhash);
>+int au_nhash_test_longer_wh(struct au_nhash *whlist, aufs_bindex_t btgt,
>+			    int limit);
>+int au_nhash_test_known_wh(struct au_nhash *whlist, char *name, int namelen);
>+int au_nhash_append_wh(struct au_nhash *whlist, char *name, int namelen,
>+		       ino_t ino, unsigned int d_type, aufs_bindex_t bindex,
>+		    unsigned char shwh);
>+void au_vdir_free(struct au_vdir *vdir);
>+int au_vdir_init(struct file *file);
>+int au_vdir_fill_de(struct file *file, void *dirent, filldir_t filldir);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline
>+void au_shwh_init_wh(struct au_vdir_wh *wh, ino_t ino, unsigned char d_type)
>+{
>+#ifdef CONFIG_AUFS_SHWH
>+	wh->wh_ino = ino;
>+	wh->wh_type = d_type;
>+#endif
>+}
>+
>+static inline void au_add_nlink(struct inode *dir, struct inode *h_dir)
>+{
>+	AuDebugOn(!S_ISDIR(dir->i_mode) || !S_ISDIR(h_dir->i_mode));
>+	dir->i_nlink += h_dir->i_nlink - 2;
>+	if (unlikely(h_dir->i_nlink < 2))
>+		dir->i_nlink += 2;
>+}
>+
>+static inline void au_sub_nlink(struct inode *dir, struct inode *h_dir)
>+{
>+	AuDebugOn(!S_ISDIR(dir->i_mode) || !S_ISDIR(h_dir->i_mode));
>+	dir->i_nlink -= h_dir->i_nlink - 2;
>+	if (unlikely(h_dir->i_nlink < 2))
>+		dir->i_nlink -= 2;
>+}
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_DIR_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/dlgt.c linux-2.6.25.4-unionfs/fs/aufs/dlgt.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/dlgt.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/dlgt.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,113 @@
>+/*
>+ * Copyright (C) 2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * lookup functions in 'delegate' mode
>+ *
>+ * $Id: dlgt.c,v 1.2 2008/04/21 02:00:37 sfjro Exp $
>+ */
>+
>+//#include <linux/security.h>
>+#include "aufs.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_lookup_one_len_args {
>+	struct dentry **errp;
>+	const char *name;
>+	struct dentry *parent;
>+	int len;
>+};
>+
>+static void au_call_lookup_one_len(void *args)
>+{
>+	struct au_lookup_one_len_args *a = args;
>+	*a->errp = vfsub_lookup_one_len(a->name, a->parent, a->len);
>+}
>+
>+struct dentry *au_lkup_one_dlgt(const char *name, struct dentry *parent,
>+				int len, unsigned int flags)
>+{
>+	struct dentry *dentry;
>+	int dirperm1;
>+
>+	LKTRTrace("%.*s/%.*s, 0x%x\n", AuDLNPair(parent), len, name, flags);
>+
>+	dirperm1 = au_ftest_ndx(flags, DIRPERM1);
>+	if (!dirperm1 && !au_ftest_ndx(flags, DLGT))
>+		dentry = vfsub_lookup_one_len(name, parent, len);
>+	else {
>+		int wkq_err;
>+		struct au_lookup_one_len_args args = {
>+			.errp	= &dentry,
>+			.name	= name,
>+			.parent	= parent,
>+			.len	= len
>+		};
>+		wkq_err = au_wkq_wait(au_call_lookup_one_len, &args,
>+				      /*dlgt*/!dirperm1);
>+		if (unlikely(wkq_err))
>+			dentry = ERR_PTR(wkq_err);
>+	}
>+
>+	AuTraceErrPtr(dentry);
>+	return dentry;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct security_inode_permission_args {
>+	int *errp;
>+	struct inode *h_inode;
>+	int mask;
>+	struct nameidata *fake_nd;
>+};
>+
>+static void call_security_inode_permission(void *args)
>+{
>+	struct security_inode_permission_args *a = args;
>+	LKTRTrace("fsuid %d\n", current->fsuid);
>+	*a->errp = security_inode_permission(a->h_inode, a->mask, a->fake_nd);
>+}
>+
>+int au_security_inode_permission(struct inode *h_inode, int mask,
>+				 struct nameidata *fake_nd, int dlgt)
>+{
>+	int err;
>+
>+	AuTraceEnter();
>+
>+	if (!dlgt)
>+		err = security_inode_permission(h_inode, mask, fake_nd);
>+	else {
>+		int wkq_err;
>+		struct security_inode_permission_args args = {
>+			.errp		= &err,
>+			.h_inode	= h_inode,
>+			.mask		= mask,
>+			.fake_nd	= fake_nd
>+		};
>+		wkq_err = au_wkq_wait(call_security_inode_permission, &args,
>+				      /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/export.c linux-2.6.25.4-unionfs/fs/aufs/export.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/export.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/export.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,578 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * export via nfs
>+ *
>+ * $Id: export.c,v 1.4 2008/05/04 23:52:08 sfjro Exp $
>+ */
>+
>+#include <linux/exportfs.h>
>+#include "aufs.h"
>+
>+union conv {
>+#if BITS_PER_LONG == 32
>+	__u32 a[1];
>+#else
>+	__u32 a[2];
>+#endif
>+	ino_t ino;
>+};
>+
>+static ino_t decode_ino(__u32 *a)
>+{
>+	union conv u;
>+
>+	u.a[0] = a[0];
>+#if BITS_PER_LONG == 64
>+	u.a[1] = a[1];
>+#endif
>+	return u.ino;
>+}
>+
>+static void encode_ino(__u32 *a, ino_t ino)
>+{
>+	union conv u;
>+
>+	u.ino = ino;
>+	a[0] = u.a[0];
>+#if BITS_PER_LONG == 64
>+	a[1] = u.a[1];
>+#endif
>+}
>+
>+/* NFS file handle */
>+enum {
>+	Fh_br_id,
>+	Fh_sigen,
>+#if BITS_PER_LONG == 64
>+	/* support 64bit inode number */
>+	Fh_ino1,
>+	Fh_ino2,
>+	Fh_dir_ino1,
>+	Fh_dir_ino2,
>+	Fh_h_ino1,
>+	Fh_h_ino2,
>+#else
>+	Fh_ino1,
>+	Fh_dir_ino1,
>+	Fh_h_ino1,
>+#endif
>+	Fh_h_igen,
>+	Fh_h_type,
>+	Fh_tail,
>+
>+	Fh_ino = Fh_ino1,
>+	Fh_dir_ino = Fh_dir_ino1,
>+	Fh_h_ino = Fh_h_ino1,
>+};
>+
>+static int au_test_anon(struct dentry *dentry)
>+{
>+	return !!(dentry->d_flags & DCACHE_DISCONNECTED);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static struct dentry *decode_by_ino(struct super_block *sb, ino_t ino,
>+				    ino_t dir_ino)
>+{
>+	struct dentry *dentry, *parent;
>+	struct inode *inode;
>+
>+	LKTRTrace("i%lu, diri%lu\n", ino, dir_ino);
>+
>+	dentry = NULL;
>+	inode = ilookup(sb, ino);
>+	if (unlikely(!inode))
>+		goto out;
>+
>+	dentry = ERR_PTR(-ESTALE);
>+	if (unlikely(is_bad_inode(inode)))
>+		goto out_iput;
>+
>+	dentry = NULL;
>+	if (!S_ISDIR(inode->i_mode)) {
>+		struct dentry *d;
>+		spin_lock(&dcache_lock);
>+		list_for_each_entry(d, &inode->i_dentry, d_alias)
>+			if (!au_test_anon(d)
>+			    && d->d_parent->d_inode->i_ino == dir_ino) {
>+				dentry = dget_locked(d);
>+				break;
>+			}
>+		spin_unlock(&dcache_lock);
>+	} else {
>+		dentry = d_find_alias(inode);
>+		if (dentry && !au_test_anon(dentry)) {
>+			int same_ino;
>+			parent = dget_parent(dentry);
>+			same_ino = (parent->d_inode->i_ino == dir_ino);
>+			dput(parent);
>+			if (same_ino)
>+				goto out_iput; /* success */
>+		}
>+
>+		dput(dentry);
>+		dentry = NULL;
>+	}
>+
>+ out_iput:
>+	iput(inode);
>+ out:
>+	AuTraceErrPtr(dentry);
>+	return dentry;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct find_name_by_ino {
>+	int called, found;
>+	ino_t ino;
>+	char *name;
>+	int namelen;
>+};
>+
>+static int
>+find_name_by_ino(void *arg, const char *name, int namelen, loff_t offset,
>+		 u64 ino, unsigned int d_type)
>+{
>+	struct find_name_by_ino *a = arg;
>+
>+	a->called++;
>+	if (a->ino != ino)
>+		return 0;
>+
>+	memcpy(a->name, name, namelen);
>+	a->namelen = namelen;
>+	a->found = 1;
>+	return 1;
>+}
>+
>+static struct dentry *decode_by_dir_ino(struct super_block *sb, ino_t ino,
>+					ino_t dir_ino)
>+{
>+	struct dentry *dentry, *parent;
>+	struct inode *dir;
>+	struct find_name_by_ino arg;
>+	struct file *file;
>+	int err;
>+
>+	LKTRTrace("i%lu, diri%lu\n", ino, dir_ino);
>+
>+	dentry = NULL;
>+	dir = ilookup(sb, dir_ino);
>+	if (unlikely(!dir))
>+		goto out;
>+
>+	dentry = ERR_PTR(-ESTALE);
>+	if (unlikely(is_bad_inode(dir)))
>+		goto out_iput;
>+
>+	dentry = NULL;
>+	parent = d_find_alias(dir);
>+	if (parent) {
>+		if (unlikely(au_test_anon(parent))) {
>+			dput(parent);
>+			goto out_iput;
>+		}
>+	} else
>+		goto out_iput;
>+
>+	file = dentry_open(parent, au_mntcache_get(sb), au_dir_roflags);
>+	dentry = (void *)file;
>+	if (IS_ERR(file))
>+		goto out_iput;
>+
>+	dentry = ERR_PTR(-ENOMEM);
>+	arg.name = __getname();
>+	if (unlikely(!arg.name))
>+		goto out_fput;
>+	arg.ino = ino;
>+	arg.found = 0;
>+
>+	do {
>+		arg.called = 0;
>+		//smp_mb();
>+		err = vfsub_readdir(file, find_name_by_ino, &arg, /*dlgt*/0);
>+	} while (!err && !arg.found && arg.called);
>+	dentry = ERR_PTR(err);
>+	if (arg.found) {
>+		/* do not call au_lkup_one(), nor dlgt */
>+		mutex_lock(&dir->i_mutex);
>+		dentry = vfsub_lookup_one_len(arg.name, parent, arg.namelen);
>+		mutex_unlock(&dir->i_mutex);
>+		AuTraceErrPtr(dentry);
>+	}
>+
>+	//out_putname:
>+	__putname(arg.name);
>+ out_fput:
>+	fput(file);
>+ out_iput:
>+	iput(dir);
>+ out:
>+	AuTraceErrPtr(dentry);
>+	return dentry;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct append_name {
>+	int found, called, len;
>+	char *h_path;
>+	ino_t h_ino;
>+};
>+
>+static int append_name(void *arg, const char *name, int len, loff_t pos,
>+		       u64 ino, unsigned int d_type)
>+{
>+	struct append_name *a = arg;
>+	char *p;
>+
>+	a->called++;
>+	if (ino != a->h_ino)
>+		return 0;
>+
>+	AuDebugOn(len == 1 && *name == '.');
>+	AuDebugOn(len == 2 && name[0] == '.' && name[1] == '.');
>+	a->len = strlen(a->h_path);
>+	memmove(a->h_path - len - 1, a->h_path, a->len);
>+	a->h_path -= len + 1;
>+	p = a->h_path + a->len;
>+	*p++ = '/';
>+	memcpy(p, name, len);
>+	a->len += 1 + len;
>+	a->found++;
>+	return 1;
>+}
>+
>+static int h_acceptable(void *expv, struct dentry *dentry)
>+{
>+	return 1;
>+}
>+
>+static char *au_build_path(struct super_block *sb, __u32 *fh, char *path,
>+			     struct vfsmount *h_mnt, struct dentry *h_root,
>+			     struct dentry *h_parent)
>+{
>+	char *ret;
>+	int err, len;
>+	struct file *h_file;
>+	struct append_name arg;
>+	struct path dm_path = {
>+		.mnt	= h_mnt,
>+		.dentry	= h_root
>+	};
>+
>+	AuTraceEnter();
>+
>+	arg.h_path = d_path(&dm_path, path, PATH_MAX);
>+	ret = arg.h_path;
>+	if (unlikely(!arg.h_path || IS_ERR(arg.h_path)))
>+		goto out;
>+
>+	len = strlen(arg.h_path);
>+	dm_path.dentry = h_parent;
>+	arg.h_path = d_path(&dm_path, path, PATH_MAX);
>+	ret = arg.h_path;
>+	if (unlikely(!arg.h_path || IS_ERR(arg.h_path)))
>+		goto out;
>+	LKTRTrace("%s\n", arg.h_path);
>+	if (len != 1)
>+		arg.h_path += len;
>+	LKTRTrace("%p, %s, %ld\n",
>+		  arg.h_path, arg.h_path, (long)(arg.h_path - path));
>+
>+	/* cf. fs/exportfs/expfs.c */
>+	h_file = dentry_open(dget(h_parent), mntget(h_mnt), au_dir_roflags);
>+	ret = (void *)h_file;
>+	if (IS_ERR(h_file))
>+		goto out;
>+
>+	arg.found = 0;
>+	arg.h_ino = decode_ino(fh + Fh_h_ino);
>+	do {
>+		arg.called = 0;
>+		err = vfsub_readdir(h_file, append_name, &arg, /*dlgt*/0);
>+	} while (!err && !arg.found && arg.called);
>+	LKTRTrace("%p, %s, %d\n", arg.h_path, arg.h_path, arg.len);
>+	fput(h_file);
>+	ret = ERR_PTR(err);
>+	if (unlikely(err))
>+		goto out;
>+
>+	dm_path.mnt = au_mntcache_get(sb);
>+	dm_path.dentry = sb->s_root;
>+	ret = d_path(&dm_path, path, PATH_MAX - arg.len);
>+	mntput(dm_path.mnt);
>+	if (unlikely(!ret || IS_ERR(ret)))
>+		goto out;
>+	ret[strlen(ret)] = '/';
>+	LKTRTrace("%s\n", ret);
>+
>+ out:
>+	AuTraceErrPtr(ret);
>+	return ret;
>+}
>+
>+static struct dentry *
>+decode_by_path(struct super_block *sb, aufs_bindex_t bindex, __u32 *fh,
>+	       int fh_len, void *context)
>+{
>+	struct dentry *dentry, *h_parent, *root, *h_root;
>+	struct super_block *h_sb;
>+	char *path, *p;
>+	struct vfsmount *h_mnt;
>+	int err;
>+	struct nameidata nd;
>+	struct au_branch *br;
>+
>+	LKTRTrace("b%d\n", bindex);
>+	SiMustAnyLock(sb);
>+
>+	br = au_sbr(sb, bindex);
>+	/* au_br_get(br); */
>+	h_mnt = br->br_mnt;
>+	h_sb = h_mnt->mnt_sb;
>+	LKTRTrace("%s, h_decode_fh\n", au_sbtype(h_sb));
>+	/* in linux-2.6.24, it takes struct fid * as file handle */
>+	//todo: call lower fh_to_dentry()? fh_to_parent()?
>+	h_parent = exportfs_decode_fh(h_mnt, (void *)(fh + Fh_tail),
>+				      fh_len - Fh_tail, fh[Fh_h_type],
>+				      h_acceptable, /*context*/NULL);
>+	dentry = h_parent;
>+	if (unlikely(!h_parent || IS_ERR(h_parent))) {
>+		AuWarn1("%s decode_fh failed\n", au_sbtype(h_sb));
>+		goto out;
>+	}
>+	dentry = NULL;
>+	if (unlikely(au_test_anon(h_parent))) {
>+		AuWarn1("%s decode_fh returned a disconnected dentry\n",
>+			au_sbtype(h_sb));
>+		dput(h_parent);
>+		goto out;
>+	}
>+
>+	dentry = ERR_PTR(-ENOMEM);
>+	path = __getname();
>+	if (unlikely(!path)) {
>+		dput(h_parent);
>+		goto out;
>+	}
>+
>+	root = sb->s_root;
>+	di_read_lock_parent(root, !AuLock_IR);
>+	h_root = au_h_dptr(root, bindex);
>+	di_read_unlock(root, !AuLock_IR);
>+	p = au_build_path(sb, fh, path, h_mnt, h_root, h_parent);
>+	dput(h_parent);
>+	if (IS_ERR(p))
>+		goto out_putname;
>+
>+	err = vfsub_path_lookup(p, LOOKUP_FOLLOW, &nd);
>+	dentry = ERR_PTR(err);
>+	if (!err) {
>+		dentry = dget(nd.path.dentry);
>+		if (unlikely(au_test_anon(dentry))) {
>+			dput(dentry);
>+			dentry = ERR_PTR(-ESTALE);
>+		}
>+		path_put(&nd.path);
>+	}
>+
>+ out_putname:
>+	__putname(path);
>+ out:
>+	/* au_br_put(br); */
>+	AuTraceErrPtr(dentry);
>+	return dentry;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static noinline_for_stack struct dentry *
>+aufs_decode_fh(struct super_block *sb, __u32 *fh, int fh_len, int fh_type,
>+	       int (*acceptable)(void *context, struct dentry *de),
>+	       void *context)
>+{
>+	struct dentry *dentry;
>+	ino_t ino, dir_ino;
>+	aufs_bindex_t bindex, br_id;
>+	struct inode *inode, *h_inode;
>+	au_gen_t sigen;
>+
>+	//au_debug_on();
>+	LKTRTrace("%d, fh{i%u, br_id %u, sigen %u, hi%u}\n",
>+		  fh_type, fh[Fh_ino], fh[Fh_br_id], fh[Fh_sigen],
>+		  fh[Fh_h_ino]);
>+	AuDebugOn(fh_len < Fh_tail);
>+
>+	si_read_lock(sb, AuLock_FLUSH);
>+	lockdep_off();
>+
>+	/* branch id may be wrapped around */
>+	dentry = ERR_PTR(-ESTALE);
>+	br_id = fh[Fh_br_id];
>+	sigen = fh[Fh_sigen];
>+	bindex = au_br_index(sb, br_id);
>+	if (unlikely(bindex < 0 || sigen + AUFS_BRANCH_MAX <= au_sigen(sb)))
>+		goto out;
>+
>+	/* is this inode still cached? */
>+	ino = decode_ino(fh + Fh_ino);
>+	dir_ino = decode_ino(fh + Fh_dir_ino);
>+	dentry = decode_by_ino(sb, ino, dir_ino);
>+	if (IS_ERR(dentry))
>+		goto out;
>+	if (dentry)
>+		goto accept;
>+
>+	/* is the parent dir cached? */
>+	dentry = decode_by_dir_ino(sb, ino, dir_ino);
>+	if (IS_ERR(dentry))
>+		goto out;
>+	if (dentry)
>+		goto accept;
>+
>+	/* lookup path */
>+	dentry = decode_by_path(sb, bindex, fh, fh_len, context);
>+	if (IS_ERR(dentry))
>+		goto out;
>+	if (unlikely(!dentry))
>+		goto out_stale;
>+	if (unlikely(dentry->d_inode->i_ino != ino))
>+		goto out_dput;
>+
>+ accept:
>+	inode = dentry->d_inode;
>+	h_inode = NULL;
>+	ii_read_lock_child(inode);
>+	if (au_ibstart(inode) <= bindex && bindex <= au_ibend(inode))
>+		h_inode = au_h_iptr(inode, bindex);
>+	ii_read_unlock(inode);
>+	if (h_inode
>+	    && h_inode->i_generation == fh[Fh_h_igen]
>+	    && acceptable(context, dentry))
>+		goto out; /* success */
>+ out_dput:
>+	dput(dentry);
>+ out_stale:
>+	dentry = ERR_PTR(-ESTALE);
>+ out:
>+	lockdep_on();
>+	si_read_unlock(sb);
>+	AuTraceErrPtr(dentry);
>+	//au_debug_off();
>+	return dentry;
>+}
>+
>+static struct dentry *
>+aufs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
>+		  int fh_type)
>+{
>+	return aufs_decode_fh(sb, fid->raw, fh_len, fh_type, h_acceptable,
>+			      /*context*/NULL);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int aufs_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
>+			  int connectable)
>+{
>+	int err;
>+	struct super_block *sb, *h_sb;
>+	struct inode *inode, *h_inode, *dir;
>+	aufs_bindex_t bindex;
>+	union conv u;
>+	struct dentry *parent, *h_parent;
>+
>+	//au_debug_on();
>+	BUILD_BUG_ON(sizeof(u.ino) != sizeof(u.a));
>+	LKTRTrace("%.*s, max %d, conn %d\n",
>+		  AuDLNPair(dentry), *max_len, connectable);
>+	AuDebugOn(au_test_anon(dentry));
>+	inode = dentry->d_inode;
>+	AuDebugOn(!inode);
>+	parent = dget_parent(dentry);
>+	AuDebugOn(au_test_anon(parent));
>+
>+	err = -ENOSPC;
>+	if (unlikely(*max_len <= Fh_tail)) {
>+		AuWarn1("NFSv2 client (max_len %d)?\n", *max_len);
>+		goto out;
>+	}
>+
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	di_read_lock_child(dentry, AuLock_IR);
>+	di_read_lock_parent(parent, AuLock_IR);
>+#ifdef CONFIG_AUFS_DEBUG
>+	if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
>+		AuWarn1("NFS-exporting requires xino\n");
>+#endif
>+
>+	err = -EPERM;
>+	bindex = au_dbstart(dentry);
>+	h_sb = au_sbr_sb(sb, bindex);
>+	if (unlikely(!h_sb->s_export_op)) {
>+		AuErr1("%s branch is not exportable\n", au_sbtype(h_sb));
>+		goto out_unlock;
>+	}
>+
>+	fh[Fh_br_id] = au_sbr_id(sb, bindex);
>+	fh[Fh_sigen] = au_sigen(sb);
>+	encode_ino(fh + Fh_ino, inode->i_ino);
>+	dir = parent->d_inode;
>+	encode_ino(fh + Fh_dir_ino, dir->i_ino);
>+	h_inode = au_h_dptr(dentry, bindex)->d_inode;
>+	encode_ino(fh + Fh_h_ino, h_inode->i_ino);
>+	fh[Fh_h_igen] = h_inode->i_generation;
>+
>+	*max_len -= Fh_tail;
>+	//LKTRTrace("Fh_tail %d, max_len %d\n", Fh_tail, *max_len);
>+	h_parent = au_h_dptr(parent, bindex);
>+	AuDebugOn(au_test_anon(h_parent));
>+	/* in linux-2.6.24, it takes struct fid * as file handle */
>+	fh[Fh_h_type] = exportfs_encode_fh(h_parent, (void *)(fh + Fh_tail),
>+					   max_len, connectable);
>+	err = fh[Fh_h_type];
>+	*max_len += Fh_tail;
>+	if (err != 255)
>+		err = 2; //??
>+	else
>+		AuWarn1("%s encode_fh failed\n", au_sbtype(h_sb));
>+
>+ out_unlock:
>+	di_read_unlock(parent, AuLock_IR);
>+	aufs_read_unlock(dentry, AuLock_IR);
>+ out:
>+	dput(parent);
>+	AuTraceErr(err);
>+	//au_debug_off();
>+	if (unlikely(err < 0))
>+		err = 255;
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct export_operations aufs_export_op = {
>+	.fh_to_dentry	= aufs_fh_to_dentry,
>+	.encode_fh	= aufs_encode_fh
>+};
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/file.c linux-2.6.25.4-unionfs/fs/aufs/file.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/file.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/file.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,755 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * handling file/dir, and address_space operation
>+ *
>+ * $Id: file.c,v 1.4 2008/05/04 23:54:53 sfjro Exp $
>+ */
>+
>+//#include <linux/fsnotify.h>
>+#include <linux/pagemap.h>
>+//#include <linux/poll.h>
>+//#include <linux/security.h>
>+#include "aufs.h"
>+
>+/*
>+ * a dirty trick for handling FMODE_EXEC and deny_write_access().
>+ * because FMODE_EXEC flag is not passed to f_op->open(),
>+ * set it to file->private_data temporary.
>+ */
>+#if !defined(CONFIG_AUFS_MODULE) || defined(CONFIG_AUFS_DENY_WRITE_ACCESS_PATCH)
>+int au_store_fmode_exec(struct nameidata *nd, struct inode *inode)
>+{
>+	int err;
>+	union {
>+		void *p;
>+		unsigned long ul;
>+	} u;
>+
>+	err = 0;
>+	if (nd
>+	    && (nd->flags & LOOKUP_OPEN)
>+	    && nd->intent.open.file
>+	    && (nd->intent.open.flags & FMODE_EXEC)
>+	    && inode
>+	    && S_ISREG(inode->i_mode)) {
>+		u.ul = nd->intent.open.flags;
>+		nd->intent.open.file->private_data = u.p;
>+		//smp_mb();
>+		err = 1;
>+	}
>+
>+	return err;
>+}
>+#endif
>+
>+/* drop flags for writing */
>+unsigned int au_file_roflags(unsigned int flags)
>+{
>+	flags &= ~(O_WRONLY | O_RDWR | O_APPEND | O_CREAT | O_TRUNC);
>+	flags |= O_RDONLY | O_NOATIME;
>+	return flags;
>+}
>+
>+/* common functions to regular file and dir */
>+struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
>+		       struct file *file)
>+{
>+	struct file *h_file;
>+	struct dentry *h_dentry;
>+	struct inode *h_inode;
>+	struct super_block *sb;
>+	struct au_branch *br;
>+	int hinotify, err;
>+
>+	LKTRTrace("%.*s, b%d, flags 0%o, f %d\n",
>+		  AuDLNPair(dentry), bindex, flags, !!file);
>+	AuDebugOn(!dentry);
>+	h_dentry = au_h_dptr(dentry, bindex);
>+	AuDebugOn(!h_dentry);
>+	h_inode = h_dentry->d_inode;
>+	AuDebugOn(!h_inode);
>+
>+	sb = dentry->d_sb;
>+	hinotify = !!au_opt_test(au_mntflags(sb), UDBA_INOTIFY);
>+
>+	br = au_sbr(sb, bindex);
>+	au_br_get(br);
>+	/* drop flags for writing */
>+	if (au_test_ro(sb, bindex, dentry->d_inode))
>+		flags = au_file_roflags(flags);
>+	flags &= ~O_CREAT;
>+
>+	h_file = NULL;
>+	if (unlikely(file && au_test_nfs(h_dentry->d_sb)))
>+		h_file = au_h_intent(dentry, bindex, file);
>+	if (!h_file) {
>+		//DbgSleep(3);
>+		h_file = dentry_open(dget(h_dentry), mntget(br->br_mnt), flags);
>+		//if (LktrCond) {fput(h_file); h_file = ERR_PTR(-1);}
>+	}
>+
>+	/*
>+	 * a dirty trick for handling FMODE_EXEC and deny_write_access().
>+	 */
>+	if (file && (file->f_mode & FMODE_EXEC)) {
>+		h_file->f_mode |= FMODE_EXEC;
>+		smp_mb(); /* flush f_mode */
>+		err = au_deny_write_access(h_file);
>+		if (unlikely(err)) {
>+			fput(h_file);
>+			h_file = ERR_PTR(err);
>+		}
>+	}
>+	if (!IS_ERR(h_file))
>+		return h_file;
>+
>+	au_br_put(br);
>+	AuTraceErrPtr(h_file);
>+	return h_file;
>+}
>+
>+static int do_coo(struct dentry *dentry, aufs_bindex_t bstart)
>+{
>+	int err;
>+	struct dentry *parent, *h_parent, *h_dentry, *gparent;
>+	aufs_bindex_t bcpup;
>+	struct inode *h_dir, *h_inode, *dir;
>+	struct super_block *sb;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	AuDebugOn(IS_ROOT(dentry));
>+	DiMustWriteLock(dentry);
>+
>+	parent = dget_parent(dentry);
>+	di_write_lock_parent(parent);
>+	sb = dentry->d_sb;
>+	err = AuWbrCopyup(au_sbi(sb), dentry);
>+	bcpup = err;
>+	if (err < 0) {
>+		err = 0; /* stop copyup, it is not an error */
>+		goto out;
>+	}
>+	err = 0;
>+
>+	h_parent = au_h_dptr(parent, bcpup);
>+	if (!h_parent) {
>+		err = au_cpup_dirs(dentry, bcpup, NULL);
>+		if (unlikely(err))
>+			goto out;
>+		h_parent = au_h_dptr(parent, bcpup);
>+	}
>+
>+	h_dir = h_parent->d_inode;
>+	h_dentry = au_h_dptr(dentry, bstart);
>+	h_inode = h_dentry->d_inode;
>+	dir = parent->d_inode;
>+	//todo: meaningless lock if CONFIG_AUFS_DEBUG is disabled.
>+	gparent = NULL;
>+	if (unlikely(au_opt_test(au_mntflags(sb), UDBA_INOTIFY)
>+		     && !IS_ROOT(parent))) {
>+		gparent = dget_parent(parent);
>+		ii_read_lock_parent2(gparent->d_inode);
>+	}
>+	au_hdir_lock(h_dir, dir, bcpup);
>+	//todo: test parent-gparent relationship
>+	mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
>+	AuDebugOn(au_h_dptr(dentry, bcpup));
>+	err = au_sio_cpup_simple(dentry, bcpup, -1, AuCpup_DTIME);
>+	AuTraceErr(err);
>+	mutex_unlock(&h_inode->i_mutex);
>+	au_hdir_unlock(h_dir, dir, bcpup);
>+	if (unlikely(gparent)) {
>+		ii_read_unlock(gparent->d_inode);
>+		dput(gparent);
>+	}
>+
>+ out:
>+	di_write_unlock(parent);
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_do_open(struct inode *inode, struct file *file,
>+	       int (*open)(struct file *file, int flags))
>+{
>+	int err, coo;
>+	struct dentry *dentry;
>+	struct super_block *sb;
>+	aufs_bindex_t bstart;
>+	//struct inode *h_dir, *dir;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("i%lu, %.*s\n", inode->i_ino, AuDLNPair(dentry));
>+
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	coo = 0;
>+	switch (au_mntflags(sb) & AuOptMask_COO) {
>+	case AuOpt_COO_LEAF:
>+		coo = !S_ISDIR(inode->i_mode);
>+		break;
>+	case AuOpt_COO_ALL:
>+		coo = 1;
>+		break;
>+	}
>+	err = au_finfo_init(file);
>+	//if (LktrCond) {fi_write_unlock(file); fin_finfo(file); err = -1;}
>+	if (unlikely(err))
>+		goto out;
>+
>+	if (!coo) {
>+		di_read_lock_child(dentry, AuLock_IR);
>+		bstart = au_dbstart(dentry);
>+	} else {
>+		di_write_lock_child(dentry);
>+		bstart = au_dbstart(dentry);
>+		if (au_test_ro(sb, bstart, dentry->d_inode)) {
>+			err = do_coo(dentry, bstart);
>+			if (err) {
>+				di_write_unlock(dentry);
>+				goto out_finfo;
>+			}
>+			bstart = au_dbstart(dentry);
>+		}
>+		di_downgrade_lock(dentry, AuLock_IR);
>+	}
>+
>+	err = open(file, file->f_flags);
>+	//if (LktrCond) err = -1;
>+	di_read_unlock(dentry, AuLock_IR);
>+
>+ out_finfo:
>+	fi_write_unlock(file);
>+	if (unlikely(err))
>+		au_finfo_fin(file);
>+	//DbgFile(file);
>+ out:
>+	si_read_unlock(sb);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_reopen_nondir(struct file *file)
>+{
>+	int err;
>+	struct dentry *dentry;
>+	aufs_bindex_t bstart, bindex, bend;
>+	struct file *h_file, *h_file_tmp;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	bstart = au_dbstart(dentry);
>+	AuDebugOn(S_ISDIR(dentry->d_inode->i_mode)
>+		  || !au_h_dptr(dentry, bstart)->d_inode);
>+
>+	h_file_tmp = NULL;
>+	if (au_fbstart(file) == bstart) {
>+		h_file = au_h_fptr(file, bstart);
>+		if (file->f_mode == h_file->f_mode)
>+			return 0; /* success */
>+		h_file_tmp = h_file;
>+		get_file(h_file_tmp);
>+		au_set_h_fptr(file, bstart, NULL);
>+	}
>+	AuDebugOn(au_fbstart(file) < bstart
>+		  || au_fi(file)->fi_hfile[0 + bstart].hf_file);
>+
>+	h_file = au_h_open(dentry, bstart, file->f_flags & ~O_TRUNC, file);
>+	//if (LktrCond) {fput(h_file); au_br_put(au_sbr(dentry->d_sb, bstart));
>+	//h_file = ERR_PTR(-1);}
>+	err = PTR_ERR(h_file);
>+	if (IS_ERR(h_file))
>+		goto out; // close all?
>+	err = 0;
>+	//cpup_file_flags(h_file, file);
>+	au_set_fbstart(file, bstart);
>+	au_set_h_fptr(file, bstart, h_file);
>+	au_update_figen(file);
>+	//file->f_ra = h_file->f_ra; //??
>+
>+	/* close lower files */
>+	bend = au_fbend(file);
>+	for (bindex = bstart + 1; bindex <= bend; bindex++)
>+		au_set_h_fptr(file, bindex, NULL);
>+	au_set_fbend(file, bstart);
>+
>+ out:
>+	if (h_file_tmp)
>+		fput(h_file_tmp);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * prepare the @file for writing.
>+ */
>+int au_ready_to_write(struct file *file, loff_t len)
>+{
>+	int err;
>+	struct dentry *dentry, *parent, *h_dentry, *h_parent, *hi_wh,
>+		*old_h_dentry, *gparent;
>+	struct inode *h_inode, *h_dir, *inode, *dir;
>+	struct super_block *sb;
>+	aufs_bindex_t bstart, bcpup, old_bstart;
>+	struct au_dinfo *dinfo;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, len %Ld\n", AuDLNPair(dentry), len);
>+	FiMustWriteLock(file);
>+
>+	sb = dentry->d_sb;
>+	bstart = au_fbstart(file);
>+	AuDebugOn(au_fbr(file, bstart) != au_sbr(sb, bstart));
>+
>+	inode = dentry->d_inode;
>+	AuDebugOn(S_ISDIR(inode->i_mode));
>+	ii_read_lock_child(inode);
>+	LKTRTrace("rdonly %d, bstart %d\n",
>+		  au_test_ro(sb, bstart, inode), bstart);
>+	err = au_test_ro(sb, bstart, inode);
>+	ii_read_unlock(inode);
>+	if (!err && (au_h_fptr(file, bstart)->f_mode & FMODE_WRITE))
>+		return 0;
>+
>+	/* need to cpup */
>+	di_write_lock_child(dentry);
>+	parent = dget_parent(dentry);
>+	di_write_lock_parent(parent);
>+	err = AuWbrCopyup(au_sbi(sb), dentry);
>+	bcpup = err;
>+	if (unlikely(err < 0))
>+		goto out_unlock;
>+	err = 0;
>+
>+	h_parent = au_h_dptr(parent, bcpup);
>+	if (!h_parent) {
>+		err = au_cpup_dirs(dentry, bcpup, NULL);
>+		//if (LktrCond) err = -1;
>+		if (unlikely(err))
>+			goto out_unlock;
>+		h_parent = au_h_dptr(parent, bcpup);
>+	}
>+
>+	//todo: meaningless lock if CONFIG_AUFS_DEBUG is disabled.
>+	gparent = NULL;
>+	if (unlikely(au_opt_test(au_mntflags(sb), UDBA_INOTIFY)
>+		     && !IS_ROOT(parent))) {
>+		gparent = dget_parent(parent);
>+		ii_read_lock_parent2(gparent->d_inode);
>+	}
>+	h_dir = h_parent->d_inode;
>+	h_dentry = au_h_fptr(file, au_fbstart(file))->f_dentry;
>+	h_inode = h_dentry->d_inode;
>+	dir = parent->d_inode;
>+	au_hdir_lock(h_dir, dir, bcpup);
>+	//todo: test parent-gparent relationship
>+	mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
>+	if (d_unhashed(dentry) /* || d_unhashed(h_dentry) */
>+	    /* || !h_inode->i_nlink */) {
>+		hi_wh = au_hi_wh(inode, bcpup);
>+		if (!hi_wh)
>+			err = au_sio_cpup_wh(dentry, bcpup, len, file);
>+		else {
>+			/* already copied-up after unlink */
>+			dinfo = au_di(dentry);
>+			old_bstart = dinfo->di_bstart;
>+			dinfo->di_bstart = bcpup;
>+			old_h_dentry = dinfo->di_hdentry[0 + bcpup].hd_dentry;
>+			dinfo->di_hdentry[0 + bcpup].hd_dentry = hi_wh;
>+			err = au_reopen_nondir(file);
>+			dinfo->di_hdentry[0 + bcpup].hd_dentry = old_h_dentry;
>+			dinfo->di_bstart = old_bstart;
>+		}
>+		//if (LktrCond) err = -1;
>+		AuTraceErr(err);
>+	} else {
>+		if (!au_h_dptr(dentry, bcpup))
>+			err = au_sio_cpup_simple(dentry, bcpup, len,
>+						 AuCpup_DTIME);
>+		//if (LktrCond) err = -1;
>+		AuTraceErr(err);
>+		if (!err)
>+			err = au_reopen_nondir(file);
>+		//if (LktrCond) err = -1;
>+		AuTraceErr(err);
>+	}
>+	mutex_unlock(&h_inode->i_mutex);
>+	au_hdir_unlock(h_dir, dir, bcpup);
>+	if (unlikely(gparent)) {
>+		ii_read_unlock(gparent->d_inode);
>+		dput(gparent);
>+	}
>+
>+ out_unlock:
>+	di_write_unlock(parent);
>+	di_write_unlock(dentry);
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int refresh_file_by_inode(struct file *file, int *need_reopen)
>+{
>+	int err;
>+	struct au_finfo *finfo;
>+	struct dentry *dentry, *parent, *old_h_dentry, *hi_wh;
>+	struct inode *inode, *dir, *h_dir;
>+	aufs_bindex_t bstart, new_bstart, old_bstart;
>+	struct super_block *sb;
>+	struct au_dinfo *dinfo;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	FiMustWriteLock(file);
>+
>+	err = 0;
>+	finfo = au_fi(file);
>+	inode = dentry->d_inode;
>+	sb = dentry->d_sb;
>+ again:
>+	bstart = au_ibstart(inode);
>+	if (bstart == finfo->fi_bstart)
>+		goto out;
>+
>+	new_bstart = bstart;
>+	parent = dget_parent(dentry);
>+	dir = parent->d_inode;
>+	if (au_test_ro(sb, bstart, inode)) {
>+		di_read_lock_parent(parent, !AuLock_IR);
>+		err = AuWbrCopyup(au_sbi(sb), dentry);
>+		new_bstart = err;
>+		di_read_unlock(parent, !AuLock_IR);
>+		//todo: err = -1;
>+		if (unlikely(err < 0))
>+			goto out_put;
>+	}
>+	di_read_unlock(dentry, AuLock_IR);
>+	di_write_lock_child(dentry);
>+	/* someone else might change our inode while we were sleeping */
>+	if (bstart != au_ibstart(inode)) { // todo
>+		di_downgrade_lock(dentry, AuLock_IR);
>+		err = 0;
>+		dput(parent);
>+		goto again;
>+	}
>+	di_read_lock_parent(parent, AuLock_IR);
>+	bstart = new_bstart;
>+
>+	hi_wh = au_hi_wh(inode, bstart);
>+	if (au_opt_test(au_mntflags(sb), PLINK)
>+	    && au_plink_test(sb, inode)
>+	    && !d_unhashed(dentry)) {
>+		err = au_test_and_cpup_dirs(dentry, bstart, NULL);
>+
>+		/* always superio. */
>+		h_dir = au_h_dptr(parent, bstart)->d_inode;
>+		au_hdir_lock(h_dir, dir, bstart);
>+		err = au_sio_cpup_simple(dentry, bstart, -1, AuCpup_DTIME);
>+		au_hdir_unlock(h_dir, dir, bstart);
>+	} else if (hi_wh) {
>+		/* already copied-up after unlink */
>+		dinfo = au_di(dentry);
>+		old_bstart = dinfo->di_bstart;
>+		dinfo->di_bstart = bstart;
>+		old_h_dentry = dinfo->di_hdentry[0 + bstart].hd_dentry;
>+		dinfo->di_hdentry[0 + bstart].hd_dentry = hi_wh;
>+		err = au_reopen_nondir(file);
>+		dinfo->di_hdentry[0 + bstart].hd_dentry = old_h_dentry;
>+		dinfo->di_bstart = old_bstart;
>+		*need_reopen = 0;
>+	}
>+	di_read_unlock(parent, AuLock_IR);
>+	di_downgrade_lock(dentry, AuLock_IR);
>+
>+ out_put:
>+	dput(parent);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * after branch manipulating, refresh the file.
>+ */
>+static int refresh_file(struct file *file, int (*reopen)(struct file *file))
>+{
>+	int err, new_sz, need_reopen;
>+	struct dentry *dentry;
>+	aufs_bindex_t bend, bindex, bstart, brid;
>+	struct au_hfile *p;
>+	struct au_finfo *finfo;
>+	struct super_block *sb;
>+	struct inode *inode;
>+	struct file *hidden_file;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	FiMustWriteLock(file);
>+	DiMustReadLock(dentry);
>+	inode = dentry->d_inode;
>+	IiMustReadLock(inode);
>+
>+	err = -ENOMEM;
>+	sb = dentry->d_sb;
>+	finfo = au_fi(file);
>+	bstart = finfo->fi_bstart;
>+	bend = finfo->fi_bstart;
>+	new_sz = sizeof(*finfo->fi_hfile) * (au_sbend(sb) + 1);
>+	p = au_kzrealloc(finfo->fi_hfile, sizeof(*p) * (finfo->fi_bend + 1),
>+			 new_sz, GFP_KERNEL);
>+	//p = NULL;
>+	if (unlikely(!p))
>+		goto out;
>+	finfo->fi_hfile = p;
>+	hidden_file = p[0 + bstart].hf_file;
>+
>+	p = finfo->fi_hfile + finfo->fi_bstart;
>+	brid = p->hf_br->br_id;
>+	bend = finfo->fi_bend;
>+	for (bindex = finfo->fi_bstart; bindex <= bend; bindex++, p++) {
>+		struct au_hfile tmp, *q;
>+		aufs_bindex_t new_bindex;
>+
>+		if (!p->hf_file)
>+			continue;
>+		new_bindex = au_find_bindex(sb, p->hf_br);
>+		if (new_bindex == bindex)
>+			continue;
>+		if (new_bindex < 0) { // test here
>+			au_set_h_fptr(file, bindex, NULL);
>+			continue;
>+		}
>+
>+		/* swap two hidden inode, and loop again */
>+		q = finfo->fi_hfile + new_bindex;
>+		tmp = *q;
>+		*q = *p;
>+		*p = tmp;
>+		if (tmp.hf_file) {
>+			bindex--;
>+			p--;
>+		}
>+	}
>+	{
>+		aufs_bindex_t s = finfo->fi_bstart, e = finfo->fi_bend;
>+		finfo->fi_bstart = 0;
>+		finfo->fi_bend = au_sbend(sb);
>+		finfo->fi_bstart = s;
>+		finfo->fi_bend = e;
>+	}
>+
>+	p = finfo->fi_hfile;
>+	if (!au_test_mmapped(file) && !d_unhashed(dentry)) {
>+		bend = au_sbend(sb);
>+		for (finfo->fi_bstart = 0; finfo->fi_bstart <= bend;
>+		     finfo->fi_bstart++, p++)
>+			if (p->hf_file) {
>+				if (p->hf_file->f_dentry
>+				    && p->hf_file->f_dentry->d_inode)
>+					break;
>+				else
>+					au_hfput(p);
>+			}
>+	} else {
>+		bend = au_br_index(sb, brid);
>+		//LKTRTrace("%d\n", bend);
>+		for (finfo->fi_bstart = 0; finfo->fi_bstart < bend;
>+		     finfo->fi_bstart++, p++)
>+			if (p->hf_file)
>+				au_hfput(p);
>+		//LKTRTrace("%d\n", finfo->fi_bstart);
>+		bend = au_sbend(sb);
>+	}
>+
>+	p = finfo->fi_hfile + bend;
>+	for (finfo->fi_bend = bend; finfo->fi_bend >= finfo->fi_bstart;
>+	     finfo->fi_bend--, p--)
>+		if (p->hf_file) {
>+			if (p->hf_file->f_dentry
>+			    && p->hf_file->f_dentry->d_inode)
>+				break;
>+			else
>+				au_hfput(p);
>+		}
>+	AuDebugOn(finfo->fi_bend < finfo->fi_bstart);
>+	//DbgFile(file);
>+	//DbgDentry(file->f_dentry);
>+
>+	err = 0;
>+	need_reopen = 1;
>+	if (!au_test_mmapped(file))
>+		err = refresh_file_by_inode(file, &need_reopen);
>+	if (!err && need_reopen && !d_unhashed(dentry))
>+		err = reopen(file);
>+		//err = -1;
>+	if (!err) {
>+		au_update_figen(file);
>+		//DbgFile(file);
>+		return 0; /* success */
>+	}
>+
>+	/* error, close all hidden files */
>+	bend = au_fbend(file);
>+	for (bindex = au_fbstart(file); bindex <= bend; bindex++)
>+		au_set_h_fptr(file, bindex, NULL);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* common function to regular file and dir */
>+int au_reval_and_lock_finfo(struct file *file, int (*reopen)(struct file *file),
>+			    int wlock, int locked)
>+{
>+	int err, pseudo_link;
>+	struct dentry *dentry;
>+	struct super_block *sb;
>+	aufs_bindex_t bstart;
>+	au_gen_t sgen, fgen;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, w %d, l %d\n", AuDLNPair(dentry), wlock, locked);
>+	sb = dentry->d_sb;
>+	SiMustAnyLock(sb);
>+
>+	err = 0;
>+	sgen = au_sigen(sb);
>+	fi_write_lock(file);
>+	fgen = au_figen(file);
>+	di_read_lock_child(dentry, AuLock_IR);
>+	bstart = au_dbstart(dentry);
>+	pseudo_link = (bstart != au_ibstart(dentry->d_inode));
>+	di_read_unlock(dentry, AuLock_IR);
>+	if (sgen == fgen && !pseudo_link && au_fbstart(file) == bstart) {
>+		if (!wlock)
>+			fi_downgrade_lock(file);
>+		return 0; /* success */
>+	}
>+
>+	LKTRTrace("sgen %d, fgen %d\n", sgen, fgen);
>+	if (unlikely(sgen != au_digen(dentry)
>+		     || sgen != au_iigen(dentry->d_inode))) {
>+		/*
>+		 * d_path() and path_lookup() is a simple and good approach
>+		 * to revalidate. but si_rwsem in DEBUG_RWSEM will cause a
>+		 * deadlock. removed the code.
>+		 */
>+		di_write_lock_child(dentry);
>+		err = au_reval_dpath(dentry, sgen);
>+		//if (LktrCond) err = -1;
>+		di_write_unlock(dentry);
>+		if (unlikely(err < 0))
>+			goto out;
>+		AuDebugOn(au_digen(dentry) != sgen
>+			  || au_iigen(dentry->d_inode) != sgen);
>+	}
>+
>+	di_read_lock_child(dentry, AuLock_IR);
>+	err = refresh_file(file, reopen
>+			   /* , au_opt_test(au_mnt_flags(sb), REFROF) */);
>+	//if (LktrCond) err = -1;
>+	di_read_unlock(dentry, AuLock_IR);
>+	if (!err) {
>+		if (!wlock)
>+			fi_downgrade_lock(file);
>+	} else
>+		fi_write_unlock(file);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* cf. aufs_nopage() */
>+/* for madvise(2) */
>+static int aufs_readpage(struct file *file, struct page *page)
>+{
>+	AuTraceEnter();
>+	unlock_page(page);
>+	return 0;
>+}
>+
>+/* they will never be called. */
>+#ifdef CONFIG_AUFS_DEBUG
>+static int aufs_prepare_write(struct file *file, struct page *page,
>+			      unsigned from, unsigned to)
>+{ AuUnsupport(); return 0; }
>+static int aufs_commit_write(struct file *file, struct page *page,
>+			     unsigned from, unsigned to)
>+{ AuUnsupport(); return 0; }
>+static int aufs_write_begin(struct file *file, struct address_space *mapping,
>+			    loff_t pos, unsigned len, unsigned flags,
>+			    struct page **pagep, void **fsdata)
>+{ AuUnsupport(); return 0; }
>+static int aufs_write_end(struct file *file, struct address_space *mapping,
>+			  loff_t pos, unsigned len, unsigned copied,
>+			  struct page *page, void *fsdata)
>+{ AuUnsupport(); return 0; }
>+static int aufs_writepage(struct page *page, struct writeback_control *wbc)
>+{ AuUnsupport(); return 0; }
>+static void aufs_sync_page(struct page *page)
>+{ AuUnsupport(); }
>+
>+static int aufs_set_page_dirty(struct page *page)
>+{ AuUnsupport(); return 0; }
>+static void aufs_invalidatepage(struct page *page, unsigned long offset)
>+{ AuUnsupport(); }
>+static int aufs_releasepage(struct page *page, gfp_t gfp)
>+{ AuUnsupport(); return 0; }
>+static ssize_t aufs_direct_IO(int rw, struct kiocb *iocb,
>+			      const struct iovec *iov, loff_t offset,
>+			      unsigned long nr_segs)
>+{ AuUnsupport(); return 0; }
>+static struct page *aufs_get_xip_page(struct address_space *mapping,
>+				      sector_t offset, int create)
>+{ AuUnsupport(); return NULL; }
>+//static int aufs_migratepage (struct page *newpage, struct page *page)
>+//{ AuUnsupport(); return 0; }
>+#endif /* CONFIG_AUFS_DEBUG */
>+
>+struct address_space_operations aufs_aop = {
>+	.readpage	= aufs_readpage,
>+#ifdef CONFIG_AUFS_DEBUG
>+	.writepage	= aufs_writepage,
>+	.sync_page	= aufs_sync_page,
>+	//.writepages	= aufs_writepages,
>+	.set_page_dirty	= aufs_set_page_dirty,
>+	//.readpages	= aufs_readpages,
>+	.prepare_write	= aufs_prepare_write,
>+	.commit_write	= aufs_commit_write,
>+	.write_begin	= aufs_write_begin,
>+	.write_end	= aufs_write_end,
>+	//.bmap		= aufs_bmap,
>+	.invalidatepage	= aufs_invalidatepage,
>+	.releasepage	= aufs_releasepage,
>+	.direct_IO	= aufs_direct_IO,
>+	.get_xip_page	= aufs_get_xip_page,
>+	//.migratepage	= aufs_migratepage
>+#endif /* CONFIG_AUFS_DEBUG */
>+};
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/file.h linux-2.6.25.4-unionfs/fs/aufs/file.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/file.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/file.h	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,246 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * file operations
>+ *
>+ * $Id: file.h,v 1.3 2008/05/19 01:48:04 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_FILE_H__
>+#define __AUFS_FILE_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/file.h>
>+#include <linux/fs.h>
>+#include <linux/mm.h>
>+#include <linux/aufs_type.h>
>+#include "dentry.h"
>+#include "misc.h"
>+#include "super.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_branch;
>+struct au_hfile {
>+	struct file		*hf_file;
>+	struct au_branch	*hf_br;
>+};
>+
>+struct au_vdir;
>+struct au_finfo {
>+	atomic_t		fi_generation;
>+
>+	struct au_rwsem		fi_rwsem;
>+	struct au_hfile		*fi_hfile;
>+	aufs_bindex_t		fi_bstart, fi_bend;
>+
>+	union {
>+		struct vm_operations_struct	*fi_h_vm_ops;
>+		struct au_vdir			*fi_vdir_cache;
>+	};
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* file.c */
>+extern struct address_space_operations aufs_aop;
>+unsigned int au_file_roflags(unsigned int flags);
>+struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
>+		       struct file *file);
>+int au_do_open(struct inode *inode, struct file *file,
>+	       int (*open)(struct file *file, int flags));
>+int au_reopen_nondir(struct file *file);
>+int au_ready_to_write(struct file *file, loff_t len);
>+int au_reval_and_lock_finfo(struct file *file, int (*reopen)(struct file *file),
>+			    int wlock, int locked);
>+
>+/* f_op.c */
>+extern struct file_operations aufs_file_fop;
>+int aufs_flush(struct file *file, fl_owner_t id);
>+
>+/* finfo.c */
>+struct au_finfo *au_fi(struct file *file);
>+struct au_branch *au_fbr(struct file *file, aufs_bindex_t bindex);
>+struct file *au_h_fptr(struct file *file, aufs_bindex_t bindex);
>+
>+void au_hfput(struct au_hfile *hf);
>+void au_set_h_fptr(struct file *file, aufs_bindex_t bindex,
>+		   struct file *h_file);
>+
>+void au_finfo_fin(struct file *file);
>+int au_finfo_init(struct file *file);
>+
>+#ifdef CONFIG_AUFS_ROBR
>+/* robr.c */
>+struct file *au_robr_safe_file(struct vm_area_struct *vma);
>+void au_robr_reset_file(struct vm_area_struct *vma, struct file *file);
>+#else
>+static inline struct file *au_robr_safe_file(struct vm_area_struct *vma)
>+{
>+	struct file *file;
>+
>+	file = vma->vm_file;
>+	if (file->private_data && au_test_aufs(file->f_dentry->d_sb))
>+		return file;
>+	return NULL;
>+}
>+
>+static inline
>+void au_robr_reset_file(struct vm_area_struct *vma, struct file *file)
>+{
>+	vma->vm_file = file;
>+	//smp_mb(); /* flush vm_file */
>+}
>+#endif /* CONFIG_AUFS_ROBR */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+//todo: memory barrier?
>+static inline au_gen_t au_figen(struct file *f)
>+{
>+	return atomic_read(&au_fi(f)->fi_generation);
>+}
>+
>+static inline int au_test_mmapped(struct file *f)
>+{
>+	return !!(au_fi(f)->fi_h_vm_ops);
>+}
>+
>+static inline int au_test_aufs_file(struct file *f)
>+{
>+	return !(f->f_dentry->d_inode->i_mode
>+		 & (S_IFCHR | S_IFBLK | S_IFIFO | S_IFSOCK));
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#if !defined(CONFIG_AUFS_MODULE) || defined(CONFIG_AUFS_DENY_WRITE_ACCESS_PATCH)
>+int au_store_fmode_exec(struct nameidata *nd, struct inode *inode);
>+
>+static inline int au_deny_write_access(struct file *h_file)
>+{
>+	LKTRTrace("%.*s\n", AuDLNPair(h_file->f_dentry));
>+	return deny_write_access(h_file);
>+}
>+
>+static inline void au_allow_write_access(struct file *h_file)
>+{
>+	allow_write_access(h_file);
>+}
>+
>+#else
>+
>+static inline int au_store_fmode_exec(struct nameidata *nd, struct inode *inode)
>+{
>+	/* nothing */
>+	return 0;
>+}
>+
>+static inline int au_deny_write_access(struct file *h_file)
>+{
>+	/* nothing */
>+	return 0;
>+}
>+
>+static inline void au_allow_write_access(struct file *h_file)
>+{
>+	/* nothing */
>+}
>+#endif /* CONFIG_AUFS_DENY_WRITE_ACCESS_PATCH */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * fi_read_lock, fi_write_lock,
>+ * fi_read_unlock, fi_write_unlock, fi_downgrade_lock
>+ */
>+AuSimpleRwsemFuncs(fi, struct file *f, au_fi(f)->fi_rwsem);
>+
>+/* to debug easier, do not make them inlined functions */
>+#define FiMustReadLock(f) do { \
>+	SiMustAnyLock((f)->f_dentry->d_sb); \
>+	AuRwMustReadLock(&au_fi(f)->fi_rwsem); \
>+} while (0)
>+
>+#define FiMustWriteLock(f) do { \
>+	SiMustAnyLock((f)->f_dentry->d_sb); \
>+	AuRwMustWriteLock(&au_fi(f)->fi_rwsem); \
>+} while (0)
>+
>+#define FiMustAnyLock(f) do { \
>+	SiMustAnyLock((f)->f_dentry->d_sb); \
>+	AuRwMustAnyLock(&au_fi(f)->fi_rwsem); \
>+} while (0)
>+
>+#define FiMustNoWaiters(f)	AuRwMustNoWaiters(&au_fi(f)->fi_rwsem)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+// hard/soft set
>+static inline aufs_bindex_t au_fbstart(struct file *file)
>+{
>+	FiMustAnyLock(file);
>+	return au_fi(file)->fi_bstart;
>+}
>+
>+static inline aufs_bindex_t au_fbend(struct file *file)
>+{
>+	FiMustAnyLock(file);
>+	return au_fi(file)->fi_bend;
>+}
>+
>+static inline struct au_vdir *au_fvdir_cache(struct file *file)
>+{
>+	FiMustAnyLock(file);
>+	return au_fi(file)->fi_vdir_cache;
>+}
>+
>+static inline void au_set_fbstart(struct file *file, aufs_bindex_t bindex)
>+{
>+	FiMustWriteLock(file);
>+	AuDebugOn(au_sbend(file->f_dentry->d_sb) < bindex);
>+	au_fi(file)->fi_bstart = bindex;
>+}
>+
>+static inline void au_set_fbend(struct file *file, aufs_bindex_t bindex)
>+{
>+	FiMustWriteLock(file);
>+	AuDebugOn(au_sbend(file->f_dentry->d_sb) < bindex
>+		  || bindex < au_fbstart(file));
>+	au_fi(file)->fi_bend = bindex;
>+}
>+
>+static inline void au_set_fvdir_cache(struct file *file,
>+				      struct au_vdir *vdir_cache)
>+{
>+	FiMustWriteLock(file);
>+	AuDebugOn(!S_ISDIR(file->f_dentry->d_inode->i_mode)
>+		  || (au_fi(file)->fi_vdir_cache && vdir_cache));
>+	au_fi(file)->fi_vdir_cache = vdir_cache;
>+}
>+
>+static inline void au_update_figen(struct file *file)
>+{
>+	atomic_set(&au_fi(file)->fi_generation, au_digen(file->f_dentry));
>+	//smp_mb(); /* atomic_set */
>+}
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_FILE_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/finfo.c linux-2.6.25.4-unionfs/fs/aufs/finfo.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/finfo.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/finfo.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,185 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * file private data
>+ *
>+ * $Id: finfo.c,v 1.2 2008/04/21 01:35:14 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+struct au_finfo *au_fi(struct file *file)
>+{
>+	struct au_finfo *finfo = file->private_data;
>+	AuDebugOn(!finfo
>+		  || !finfo->fi_hfile
>+		  || (0 < finfo->fi_bend
>+		      && (/* au_sbi(file->f_dentry->d_sb)->si_bend
>+			     < finfo->fi_bend
>+			     || */ finfo->fi_bend < finfo->fi_bstart)));
>+	return finfo;
>+}
>+
>+struct au_branch *au_fbr(struct file *file, aufs_bindex_t bindex)
>+{
>+	struct au_finfo *finfo = au_fi(file);
>+	struct au_hfile *hf;
>+
>+	FiMustAnyLock(file);
>+	AuDebugOn(!finfo
>+		  || finfo->fi_bstart < 0
>+		  || bindex < finfo->fi_bstart
>+		  || finfo->fi_bend < bindex);
>+	hf = finfo->fi_hfile + bindex;
>+	AuDebugOn(hf->hf_br && au_br_count(hf->hf_br) <= 0);
>+	return hf->hf_br;
>+}
>+
>+struct file *au_h_fptr(struct file *file, aufs_bindex_t bindex)
>+{
>+	struct au_finfo *finfo = au_fi(file);
>+	struct au_hfile *hf;
>+
>+	FiMustAnyLock(file);
>+	AuDebugOn(!finfo
>+		  || finfo->fi_bstart < 0
>+		  || bindex < finfo->fi_bstart
>+		  || finfo->fi_bend < bindex);
>+	hf = finfo->fi_hfile + bindex;
>+	AuDebugOn(hf->hf_file
>+		  && file_count(hf->hf_file) <= 0
>+		  && au_br_count(hf->hf_br) <= 0);
>+	return hf->hf_file;
>+}
>+
>+void au_hfput(struct au_hfile *hf)
>+{
>+	if (hf->hf_file->f_mode & FMODE_EXEC)
>+		au_allow_write_access(hf->hf_file);
>+	fput(hf->hf_file);
>+	hf->hf_file = NULL;
>+	AuDebugOn(!hf->hf_br);
>+	au_br_put(hf->hf_br);
>+	hf->hf_br = NULL;
>+}
>+
>+void au_set_h_fptr(struct file *file, aufs_bindex_t bindex, struct file *val)
>+{
>+	struct au_finfo *finfo = au_fi(file);
>+	struct au_hfile *hf;
>+
>+	FiMustWriteLock(file);
>+	AuDebugOn(!finfo
>+		  || finfo->fi_bstart < 0
>+		  || bindex < finfo->fi_bstart
>+		  || finfo->fi_bend < bindex);
>+	AuDebugOn(val && file_count(val) <= 0);
>+	hf = finfo->fi_hfile + bindex;
>+	AuDebugOn(val && hf->hf_file);
>+	if (hf->hf_file)
>+		au_hfput(hf);
>+	if (val) {
>+		hf->hf_file = val;
>+		hf->hf_br = au_sbr(file->f_dentry->d_sb, bindex);
>+	}
>+}
>+
>+void au_finfo_fin(struct file *file)
>+{
>+	struct au_finfo *finfo;
>+	struct dentry *dentry;
>+	aufs_bindex_t bindex, bend;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	SiMustAnyLock(dentry->d_sb);
>+
>+	fi_write_lock(file);
>+	bend = au_fbend(file);
>+	bindex = au_fbstart(file);
>+	if (bindex >= 0)
>+		for (; bindex <= bend; bindex++)
>+			au_set_h_fptr(file, bindex, NULL);
>+
>+	finfo = au_fi(file);
>+#ifdef CONFIG_AUFS_DEBUG
>+	if (finfo->fi_bstart >= 0) {
>+		bend = au_fbend(file);
>+		for (bindex = finfo->fi_bstart; bindex <= bend; bindex++) {
>+			struct au_hfile *hf;
>+			hf = finfo->fi_hfile + bindex;
>+			AuDebugOn(hf->hf_file || hf->hf_br);
>+		}
>+	}
>+#endif
>+
>+	kfree(finfo->fi_hfile);
>+	fi_write_unlock(file);
>+	au_cache_free_finfo(finfo);
>+	//file->private_data = NULL;
>+}
>+
>+int au_finfo_init(struct file *file)
>+{
>+	struct au_finfo *finfo;
>+	struct dentry *dentry;
>+	union {
>+		void *p;
>+		unsigned long ul;
>+	} u;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	AuDebugOn(!dentry->d_inode);
>+
>+	finfo = au_cache_alloc_finfo();
>+	if (finfo) {
>+		finfo->fi_hfile = kcalloc(au_sbend(dentry->d_sb) + 1,
>+					  sizeof(*finfo->fi_hfile), GFP_KERNEL);
>+		if (finfo->fi_hfile) {
>+			au_rw_init_wlock(&finfo->fi_rwsem);
>+			finfo->fi_bstart = -1;
>+			finfo->fi_bend = -1;
>+			atomic_set(&finfo->fi_generation, au_digen(dentry));
>+			//smp_mb(); /* atomic_set */
>+
>+			/*
>+			 * a dirty trick for handling FMODE_EXEC and
>+			 * deny_write_access().
>+			 * because FMODE_EXEC flag is not passed to
>+			 * f_op->open(),
>+			 * aufs set it to file->private_data temporary in lookup
>+			 * or dentry revalidation operations.
>+			 * restore the flag to f_mode here.
>+			 */
>+			u.p = file->private_data;
>+			if (u.ul & FMODE_EXEC) {
>+				file->f_mode |= FMODE_EXEC;
>+				smp_mb(); /* flush f_mode */
>+			}
>+
>+			file->private_data = finfo;
>+			return 0; /* success */
>+		}
>+		au_cache_free_finfo(finfo);
>+	}
>+
>+	AuTraceErr(-ENOMEM);
>+	return -ENOMEM;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/f_op.c linux-2.6.25.4-unionfs/fs/aufs/f_op.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/f_op.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/f_op.c	2008-05-25 11:59:38 +0300
>@@ -0,0 +1,651 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * file and vm operations
>+ *
>+ * $Id: f_op.c,v 1.5 2008/05/19 01:48:04 sfjro Exp $
>+ */
>+
>+//#include <linux/fsnotify.h>
>+#include <linux/fs_stack.h>
>+//#include <linux/pagemap.h>
>+#include <linux/poll.h>
>+//#include <linux/security.h>
>+#include "aufs.h"
>+
>+/* common function to regular file and dir */
>+int aufs_flush(struct file *file, fl_owner_t id)
>+{
>+	int err;
>+	struct dentry *dentry;
>+	aufs_bindex_t bindex, bend;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	// aufs_read_lock_file()
>+	si_noflush_read_lock(dentry->d_sb);
>+	fi_read_lock(file);
>+	di_read_lock_child(dentry, AuLock_IW);
>+
>+	err = 0;
>+	bend = au_fbend(file);
>+	for (bindex = au_fbstart(file); !err && bindex <= bend; bindex++) {
>+		struct file *h_file;
>+		h_file = au_h_fptr(file, bindex);
>+		if (h_file && h_file->f_op && h_file->f_op->flush) {
>+			err = h_file->f_op->flush(h_file, id);
>+			if (!err)
>+				au_update_fuse_h_inode
>+					(h_file->f_vfsmnt, h_file->f_dentry);
>+			/*ignore*/
>+		}
>+	}
>+	au_cpup_attr_timesizes(dentry->d_inode);
>+
>+	di_read_unlock(dentry, AuLock_IW);
>+	fi_read_unlock(file);
>+	si_read_unlock(dentry->d_sb);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int do_open_nondir(struct file *file, int flags)
>+{
>+	int err;
>+	aufs_bindex_t bindex;
>+	struct super_block *sb;
>+	struct file *h_file;
>+	struct dentry *dentry;
>+	struct inode *inode;
>+	struct au_finfo *finfo;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, flags 0%o\n", AuDLNPair(dentry), flags);
>+	FiMustWriteLock(file);
>+	inode = dentry->d_inode;
>+	AuDebugOn(!inode || S_ISDIR(inode->i_mode));
>+
>+	err = 0;
>+	finfo = au_fi(file);
>+	finfo->fi_h_vm_ops = NULL;
>+	sb = dentry->d_sb;
>+	bindex = au_dbstart(dentry);
>+	AuDebugOn(!au_h_dptr(dentry, bindex)->d_inode);
>+	/* O_TRUNC is processed already */
>+	BUG_ON(au_test_ro(sb, bindex, inode) && (flags & O_TRUNC));
>+
>+	h_file = au_h_open(dentry, bindex, flags, file);
>+	//if (LktrCond) {fput(h_file); au_br_put(au_sbr(dentry->d_sb, bindex));
>+	//h_file = ERR_PTR(-1);}
>+	if (!IS_ERR(h_file)) {
>+		au_set_fbstart(file, bindex);
>+		au_set_fbend(file, bindex);
>+		au_set_h_fptr(file, bindex, h_file);
>+		au_update_figen(file);
>+		//file->f_ra = h_file->f_ra; //??
>+		//AuDbgFile(file);
>+		return 0; /* success */
>+	}
>+	err = PTR_ERR(h_file);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int aufs_open_nondir(struct inode *inode, struct file *file)
>+{
>+	return au_do_open(inode, file, do_open_nondir);
>+}
>+
>+static int aufs_release_nondir(struct inode *inode, struct file *file)
>+{
>+	struct super_block *sb = file->f_dentry->d_sb;
>+
>+	LKTRTrace("i%lu, %.*s\n", inode->i_ino, AuDLNPair(file->f_dentry));
>+
>+	si_noflush_read_lock(sb);
>+	au_finfo_fin(file);
>+	si_read_unlock(sb);
>+	return 0;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static ssize_t aufs_read(struct file *file, char __user *buf, size_t count,
>+			 loff_t *ppos)
>+{
>+	ssize_t err;
>+	struct dentry *dentry;
>+	struct file *h_file;
>+	struct super_block *sb;
>+	struct inode *h_inode;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, cnt %lu, pos %Ld\n",
>+		  AuDLNPair(dentry), (unsigned long)count, *ppos);
>+	//AuDbgDentry(dentry);
>+
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	err = au_reval_and_lock_finfo(file, au_reopen_nondir, /*wlock*/0,
>+				      /*locked*/0);
>+	//if (LktrCond) {fi_read_unlock(file); err = -1;}
>+	if (unlikely(err))
>+		goto out;
>+
>+	/* support LSM and notify */
>+	h_file = au_h_fptr(file, au_fbstart(file));
>+	h_inode = h_file->f_dentry->d_inode;
>+	err = vfsub_read_u(h_file, buf, count, ppos,
>+			   au_opt_test_dlgt(au_mntflags(sb)));
>+	//file->f_ra = h_file->f_ra; //??
>+	fsstack_copy_attr_atime(dentry->d_inode, h_file->f_dentry->d_inode);
>+
>+	fi_read_unlock(file);
>+ out:
>+	si_read_unlock(sb);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static ssize_t aufs_write(struct file *file, const char __user *ubuf,
>+			  size_t count, loff_t *ppos)
>+{
>+	ssize_t err;
>+	struct dentry *dentry, *parent;
>+	struct inode *inode, *dir;
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+	struct file *h_file;
>+	char __user *buf = (char __user *)ubuf;
>+	struct au_hin_ignore ign;
>+	struct vfsub_args vargs;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, cnt %lu, pos %Ld\n",
>+		  AuDLNPair(dentry), (unsigned long)count, *ppos);
>+
>+	inode = dentry->d_inode;
>+	mutex_lock(&inode->i_mutex);
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	err = au_reval_and_lock_finfo(file, au_reopen_nondir, /*wlock*/1,
>+				      /*locked*/1);
>+	//if (LktrCond) {fi_write_unlock(file); err = -1;}
>+	if (unlikely(err))
>+		goto out;
>+	err = au_ready_to_write(file, -1);
>+	//if (LktrCond) err = -1;
>+	if (unlikely(err))
>+		goto out_unlock;
>+
>+	/* support LSM and notify */
>+	mnt_flags = au_mntflags(sb);
>+	vfsub_args_init(&vargs, &ign, au_opt_test_dlgt(mnt_flags), 0);
>+	h_file = au_h_fptr(file, au_fbstart(file));
>+	if (!au_opt_test(mnt_flags, UDBA_INOTIFY))
>+		err = vfsub_write_u(h_file, buf, count, ppos, &vargs);
>+	else {
>+		parent = dget_parent(dentry);
>+		dir = parent->d_inode;
>+		ii_read_lock_parent(dir);
>+		vfsub_ign_hinode(&vargs, IN_MODIFY,
>+				 au_hi(dir, au_fbstart(file)));
>+		err = vfsub_write_u(h_file, buf, count, ppos, &vargs);
>+		ii_read_unlock(dir);
>+		dput(parent);
>+	}
>+	ii_write_lock_child(inode);
>+	au_cpup_attr_timesizes(inode);
>+	ii_write_unlock(inode);
>+
>+ out_unlock:
>+	fi_write_unlock(file);
>+ out:
>+	si_read_unlock(sb);
>+	mutex_unlock(&inode->i_mutex);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+#ifdef CONFIG_AUFS_SPLICE_PATCH
>+static int au_test_loopback(void)
>+{
>+	const char c = current->comm[4];
>+	/* true if a kernel thread named 'loop[0-9].*' accesses a file */
>+	const int loopback = (current->mm == NULL
>+			      && '0' <= c && c <= '9'
>+			      && strncmp(current->comm, "loop", 4) == 0);
>+	return loopback;
>+}
>+
>+static ssize_t aufs_splice_read(struct file *file, loff_t *ppos,
>+				struct pipe_inode_info *pipe, size_t len,
>+				unsigned int flags)
>+{
>+	ssize_t err;
>+	struct file *h_file;
>+	struct dentry *dentry;
>+	struct super_block *sb;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, pos %Ld, len %lu\n",
>+		  AuDLNPair(dentry), *ppos, (unsigned long)len);
>+
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	err = au_reval_and_lock_finfo(file, au_reopen_nondir, /*wlock*/0,
>+				      /*locked*/0);
>+	if (unlikely(err))
>+		goto out;
>+
>+	err = -EINVAL;
>+	/* support LSM and notify */
>+	h_file = au_h_fptr(file, au_fbstart(file));
>+	if (/* unlikely */(au_test_loopback())) {
>+		file->f_mapping = h_file->f_mapping;
>+		smp_mb(); /* unnecessary? */
>+	}
>+	err = vfsub_splice_to(h_file, ppos, pipe, len, flags,
>+			      au_opt_test_dlgt(au_mntflags(sb)));
>+	//file->f_ra = h_file->f_ra; //??
>+	fsstack_copy_attr_atime(dentry->d_inode, h_file->f_dentry->d_inode);
>+	fi_read_unlock(file);
>+
>+ out:
>+	si_read_unlock(sb);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static ssize_t
>+aufs_splice_write(struct pipe_inode_info *pipe, struct file *file, loff_t *ppos,
>+		  size_t len, unsigned int flags)
>+{
>+	ssize_t err;
>+	struct dentry *dentry;
>+	struct inode *inode, *h_inode;
>+	struct super_block *sb;
>+	struct file *h_file;
>+	struct au_hin_ignore ign;
>+	struct vfsub_args vargs;
>+	unsigned int mnt_flags;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, len %lu, pos %Ld\n",
>+		  AuDLNPair(dentry), (unsigned long)len, *ppos);
>+
>+	inode = dentry->d_inode;
>+	mutex_lock(&inode->i_mutex);
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	err = au_reval_and_lock_finfo(file, au_reopen_nondir, /*wlock*/1,
>+				      /*locked*/1);
>+	//if (LktrCond) {fi_write_unlock(file); err = -1;}
>+	if (unlikely(err))
>+		goto out;
>+	err = au_ready_to_write(file, -1);
>+	//if (LktrCond) err = -1;
>+	if (unlikely(err))
>+		goto out_unlock;
>+
>+	/* support LSM and notify */
>+	mnt_flags = au_mntflags(sb);
>+	vfsub_args_init(&vargs, &ign, au_opt_test_dlgt(mnt_flags), 0);
>+	h_file = au_h_fptr(file, au_fbstart(file));
>+	h_inode = h_file->f_dentry->d_inode;
>+	/* current vfs_splice_from() doesn't fire up the inotify event */
>+	if (1 || !au_opt_test(mnt_flags, UDBA_INOTIFY))
>+		err = vfsub_splice_from(pipe, h_file, ppos, len, flags, &vargs);
>+	else {
>+		//struct dentry *parent = dget_parent(dentry);
>+		//vfsub_ign_hinode(&vargs, IN_MODIFY,
>+		//au_hi(parent->d_inode, au_fbstart(file));
>+		err = vfsub_splice_from(pipe, h_file, ppos, len, flags, &vargs);
>+		//dput(parent);
>+	}
>+	ii_write_lock_child(inode);
>+	au_cpup_attr_timesizes(inode);
>+	ii_write_unlock(inode);
>+
>+ out_unlock:
>+	fi_write_unlock(file);
>+ out:
>+	si_read_unlock(sb);
>+	mutex_unlock(&inode->i_mutex);
>+	AuTraceErr(err);
>+	return err;
>+}
>+#endif /* CONFIG_AUFS_SPLICE_PATCH */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int aufs_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>+{
>+	int err;
>+	struct dentry *dentry;
>+	struct file *file, *h_file;
>+	struct inode *inode;
>+	static DECLARE_WAIT_QUEUE_HEAD(wq);
>+	struct au_finfo *finfo;
>+	//struct page *page;
>+
>+	AuTraceEnter();
>+	AuDebugOn(!vma || !vma->vm_file);
>+	//todo: non-robr mode, user vm_file as it is.
>+	wait_event(wq, (file = au_robr_safe_file(vma)));
>+	AuDebugOn(!au_test_aufs(file->f_dentry->d_sb));
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	inode = dentry->d_inode;
>+	AuDebugOn(!S_ISREG(inode->i_mode));
>+
>+	/* do not revalidate, nor si lock */
>+	finfo = au_fi(file);
>+	h_file = finfo->fi_hfile[0 + finfo->fi_bstart].hf_file;
>+	AuDebugOn(!h_file || !au_test_mmapped(file));
>+	fi_write_lock(file);
>+	vma->vm_file = h_file;
>+	err = finfo->fi_h_vm_ops->fault(vma, vmf);
>+	//file->f_ra = h_file->f_ra; //??
>+	au_robr_reset_file(vma, file);
>+	fi_write_unlock(file);
>+	wake_up(&wq);
>+
>+	if (!(err & VM_FAULT_ERROR)) {
>+		//page->mapping = file->f_mapping;
>+		//get_page(page);
>+		//file->f_mapping = h_file->f_mapping;
>+		//touch_atime(NULL, dentry);
>+		//inode->i_atime = h_file->f_dentry->d_inode->i_atime;
>+	}
>+	AuTraceErr(err);
>+	//AuDbg("err %d\n", err);
>+	return err;
>+}
>+
>+static struct vm_operations_struct aufs_vm_ops = {
>+	//.open		= aufs_vmaopen,
>+	//.close		= aufs_vmaclose,
>+	.fault		= aufs_fault,
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static struct vm_operations_struct *au_vm_ops(struct file *h_file,
>+					      struct vm_area_struct *vma)
>+{
>+	struct vm_operations_struct *vm_ops;
>+	int err;
>+
>+	AuTraceEnter();
>+
>+	if (!au_test_nfs(h_file->f_vfsmnt->mnt_sb))
>+		err = h_file->f_op->mmap(h_file, vma);
>+	else {
>+		lockdep_off();
>+		err = h_file->f_op->mmap(h_file, vma);
>+		lockdep_on();
>+	}
>+	vm_ops = ERR_PTR(err);
>+	if (unlikely(err))
>+		goto out;
>+	vm_ops = vma->vm_ops;
>+	err = do_munmap(current->mm, vma->vm_start,
>+			vma->vm_end - vma->vm_start);
>+	if (unlikely(err)) {
>+		AuIOErr("failed internal unmapping %.*s, %d\n",
>+			AuDLNPair(h_file->f_dentry), err);
>+		vm_ops = ERR_PTR(-EIO);
>+	}
>+
>+ out:
>+	AuTraceErrPtr(vm_ops);
>+	return vm_ops;
>+}
>+
>+static int aufs_mmap(struct file *file, struct vm_area_struct *vma)
>+{
>+	int err, wlock, mmapped;
>+	struct dentry *dentry;
>+	struct super_block *sb;
>+	struct file *h_file;
>+	struct vm_operations_struct *vm_ops;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, %lx, len %lu\n",
>+		  AuDLNPair(dentry), vma->vm_start,
>+		  vma->vm_end - vma->vm_start);
>+	AuDebugOn(!S_ISREG(dentry->d_inode->i_mode));
>+	AuDebugOn(down_write_trylock(&vma->vm_mm->mmap_sem));
>+
>+	mmapped = au_test_mmapped(file); /* can be harmless race condition */
>+	wlock = !!(file->f_mode & FMODE_WRITE);
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	err = au_reval_and_lock_finfo(file, au_reopen_nondir,
>+				      wlock | !mmapped, /*locked*/0);
>+	//err = -1;
>+	if (unlikely(err))
>+		goto out;
>+
>+	if (wlock) {
>+		err = au_ready_to_write(file, -1);
>+		//err = -1;
>+		if (unlikely(err))
>+			goto out_unlock;
>+	}
>+
>+	h_file = au_h_fptr(file, au_fbstart(file));
>+	if (unlikely(au_test_fuse(h_file->f_dentry->d_sb))) {
>+		/*
>+		 * by this assignment, f_mapping will differs from aufs inode
>+		 * i_mapping.
>+		 * if someone else mixes the use of f_dentry->d_inode and
>+		 * f_mapping->host, then a problem may arise.
>+		 */
>+		file->f_mapping = h_file->f_mapping;
>+	}
>+
>+	if (0 && h_file->f_op->mmap == generic_file_mmap) {
>+		err = generic_file_mmap(file, vma); /* instead of h_file */
>+		if (unlikely(err))
>+			goto out_unlock;
>+		au_fi(file)->fi_h_vm_ops = vma->vm_ops;
>+	} else {
>+		vm_ops = NULL;
>+		if (!mmapped) {
>+			vm_ops = au_vm_ops(h_file, vma);
>+			err = PTR_ERR(vm_ops);
>+			if (IS_ERR(vm_ops))
>+				goto out_unlock;
>+		}
>+
>+		err = generic_file_mmap(file, vma);
>+		if (unlikely(err))
>+			goto out_unlock;
>+		vma->vm_ops = &aufs_vm_ops;
>+		/* test again */
>+		if (!au_test_mmapped(file)) {
>+			FiMustWriteLock(file);
>+			au_fi(file)->fi_h_vm_ops = vm_ops;
>+		}
>+	}
>+
>+	file_accessed(h_file);
>+	au_update_fuse_h_inode(h_file->f_vfsmnt, h_file->f_dentry); /*ignore*/
>+	fsstack_copy_attr_atime(dentry->d_inode, h_file->f_dentry->d_inode);
>+
>+ out_unlock:
>+	if (!wlock && mmapped)
>+		fi_read_unlock(file);
>+	else
>+		fi_write_unlock(file);
>+ out:
>+	si_read_unlock(sb);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static unsigned int aufs_poll(struct file *file, poll_table *wait)
>+{
>+	unsigned int mask;
>+	struct file *h_file;
>+	int err;
>+	struct dentry *dentry;
>+	struct super_block *sb;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, wait %p\n", AuDLNPair(dentry), wait);
>+	AuDebugOn(S_ISDIR(dentry->d_inode->i_mode));
>+
>+	/* We should pretend an error happened. */
>+	mask = POLLERR /* | POLLIN | POLLOUT */;
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	err = au_reval_and_lock_finfo(file, au_reopen_nondir, /*wlock*/0,
>+				      /*locked*/0);
>+	//err = -1;
>+	if (unlikely(err))
>+		goto out;
>+
>+	/* it is not an error of hidden_file has no operation */
>+	mask = DEFAULT_POLLMASK;
>+	h_file = au_h_fptr(file, au_fbstart(file));
>+	if (h_file->f_op && h_file->f_op->poll)
>+		mask = h_file->f_op->poll(h_file, wait);
>+	fi_read_unlock(file);
>+
>+ out:
>+	si_read_unlock(sb);
>+	AuTraceErr((int)mask);
>+	return mask;
>+}
>+
>+static int aufs_fsync_nondir(struct file *file, struct dentry *dentry,
>+			     int datasync)
>+{
>+	int err;
>+	struct inode *inode;
>+	struct file *h_file;
>+	struct super_block *sb;
>+
>+	LKTRTrace("%.*s, %d\n", AuDLNPair(dentry), datasync);
>+	inode = dentry->d_inode;
>+
>+	IMustLock(file->f_mapping->host);
>+	if (unlikely(inode != file->f_mapping->host)) {
>+		mutex_unlock(&file->f_mapping->host->i_mutex);
>+		mutex_lock(&inode->i_mutex);
>+	}
>+	IMustLock(inode);
>+
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	err = 0; //-EBADF; // posix?
>+	if (unlikely(!(file->f_mode & FMODE_WRITE)))
>+		goto out;
>+	err = au_reval_and_lock_finfo(file, au_reopen_nondir, /*wlock*/1,
>+				      /*locked*/1);
>+	//err = -1;
>+	if (unlikely(err))
>+		goto out;
>+	err = au_ready_to_write(file, -1);
>+	//err = -1;
>+	if (unlikely(err))
>+		goto out_unlock;
>+
>+	err = -EINVAL;
>+	h_file = au_h_fptr(file, au_fbstart(file));
>+	if (h_file->f_op && h_file->f_op->fsync) {
>+		ii_write_lock_child(inode);
>+		mutex_lock_nested(&h_file->f_dentry->d_inode->i_mutex,
>+				  AuLsc_I_CHILD);
>+		err = h_file->f_op->fsync(h_file, h_file->f_dentry, datasync);
>+		//err = -1;
>+		if (!err)
>+			au_update_fuse_h_inode(h_file->f_vfsmnt,
>+					       h_file->f_dentry);
>+		au_cpup_attr_timesizes(inode);
>+		mutex_unlock(&h_file->f_dentry->d_inode->i_mutex);
>+		ii_write_unlock(inode);
>+	}
>+
>+ out_unlock:
>+	fi_write_unlock(file);
>+ out:
>+	si_read_unlock(sb);
>+	if (unlikely(inode != file->f_mapping->host)) {
>+		mutex_unlock(&inode->i_mutex);
>+		mutex_lock(&file->f_mapping->host->i_mutex);
>+	}
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int aufs_fasync(int fd, struct file *file, int flag)
>+{
>+	int err;
>+	struct file *h_file;
>+	struct dentry *dentry;
>+	struct super_block *sb;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, %d\n", AuDLNPair(dentry), flag);
>+
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+	err = au_reval_and_lock_finfo(file, au_reopen_nondir, /*wlock*/0,
>+				      /*locked*/0);
>+	//err = -1;
>+	if (unlikely(err))
>+		goto out;
>+
>+	h_file = au_h_fptr(file, au_fbstart(file));
>+	if (h_file->f_op && h_file->f_op->fasync)
>+		err = h_file->f_op->fasync(fd, h_file, flag);
>+	fi_read_unlock(file);
>+
>+ out:
>+	si_read_unlock(sb);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct file_operations aufs_file_fop = {
>+	.read		= aufs_read,
>+	.write		= aufs_write,
>+	.poll		= aufs_poll,
>+	.mmap		= aufs_mmap,
>+	.open		= aufs_open_nondir,
>+	.flush		= aufs_flush,
>+	.release	= aufs_release_nondir,
>+	.fsync		= aufs_fsync_nondir,
>+	.fasync		= aufs_fasync,
>+#ifdef CONFIG_AUFS_SPLICE_PATCH
>+	.splice_write	= aufs_splice_write,
>+	.splice_read	= aufs_splice_read,
>+#endif
>+};
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/hinode.h linux-2.6.25.4-unionfs/fs/aufs/hinode.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/hinode.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/hinode.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,188 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * lower (branch filesystem) inode and setting inotify
>+ *
>+ * $Id: hinode.h,v 1.3 2008/04/28 03:08:37 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_HINODE_H__
>+#define __AUFS_HINODE_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/inotify.h>
>+#include <linux/aufs_type.h>
>+//#include "branch.h"
>+//#include "inode.h"
>+#include "super.h"
>+#include "vfsub.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_hinotify {
>+#ifdef CONFIG_AUFS_HINOTIFY
>+	struct inotify_watch	hin_watch;
>+	struct inode		*hin_aufs_inode;	/* no get/put */
>+
>+	/* an array of atomic_t X au_hin_nignore */
>+	atomic_t		hin_ignore[0];
>+#endif
>+};
>+
>+struct au_hinode {
>+	struct inode		*hi_inode;
>+	aufs_bindex_t		hi_id;
>+#ifdef CONFIG_AUFS_HINOTIFY
>+	struct au_hinotify	*hi_notify;
>+#endif
>+
>+	/* reference to the copied-up whiteout with get/put */
>+	struct dentry		*hi_whdentry;
>+};
>+
>+struct au_hin_ignore {
>+#ifdef CONFIG_AUFS_HINOTIFY
>+	__u32			ign_events;
>+	struct au_hinode	*ign_hinode;
>+#endif
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#ifdef CONFIG_AUFS_HINOTIFY
>+static inline
>+void au_hin_init(struct au_hinode *hinode, struct au_hinotify *val)
>+{
>+	hinode->hi_notify = val;
>+}
>+
>+/* hinotify.c */
>+int au_hin_alloc(struct au_hinode *hinode, struct inode *inode,
>+		 struct inode *h_inode);
>+void au_hin_free(struct au_hinode *hinode);
>+void au_do_hdir_lock(struct inode *h_dir, struct inode *dir,
>+		     aufs_bindex_t bindex, unsigned int lsc);
>+void au_hdir_unlock(struct inode *h_dir, struct inode *dir,
>+		    aufs_bindex_t bindex);
>+struct dentry *au_hdir_lock_rename(struct dentry **h_parents,
>+				   struct inode **dirs, aufs_bindex_t bindex,
>+				   int issamedir);
>+void au_hdir_unlock_rename(struct dentry **h_parents, struct inode **dirs,
>+			   aufs_bindex_t bindex, int issamedir);
>+void au_reset_hinotify(struct inode *inode, unsigned int flags);
>+
>+void au_hin_ignore(struct au_hinode *hinode, __u32 events);
>+void au_hin_unignore(struct au_hinode *hinode, __u32 events);
>+
>+int __init au_inotify_init(void);
>+void au_inotify_fin(void);
>+
>+#else
>+
>+static inline
>+void au_hin_init(struct au_hinode *hinode, struct au_hinotify *val)
>+{
>+	/* empty */
>+}
>+
>+static inline
>+int au_hin_alloc(struct au_hinode *hinode, struct inode *inode,
>+		 struct inode *h_inode)
>+{
>+	return -EOPNOTSUPP;
>+}
>+
>+static inline void au_hin_free(struct au_hinode *hinode)
>+{
>+	/* nothing */
>+}
>+
>+static inline
>+void au_do_hdir_lock(struct inode *h_dir, struct inode *dir,
>+		     aufs_bindex_t bindex, unsigned int lsc)
>+{
>+	mutex_lock_nested(&h_dir->i_mutex, lsc);
>+}
>+
>+static inline
>+void au_hdir_unlock(struct inode *h_dir, struct inode *dir,
>+		    aufs_bindex_t bindex)
>+{
>+	mutex_unlock(&h_dir->i_mutex);
>+}
>+
>+static inline
>+struct dentry *au_hdir_lock_rename(struct dentry **h_parents,
>+				   struct inode **dirs, aufs_bindex_t bindex,
>+				   int issamedir)
>+{
>+	return vfsub_lock_rename(h_parents[0], h_parents[1]);
>+}
>+
>+static inline
>+void au_hdir_unlock_rename(struct dentry **h_parents, struct inode **dirs,
>+			   aufs_bindex_t bindex, int issamedir)
>+{
>+	vfsub_unlock_rename(h_parents[0], h_parents[1]);
>+}
>+
>+static inline void au_reset_hinotify(struct inode *inode, unsigned int flags)
>+{
>+	/* nothing */
>+}
>+
>+static inline void au_hin_ignore(struct au_hinotify *hinotify, __u32 events)
>+{
>+	/* nothing */
>+}
>+
>+static inline void au_hin_unignore(struct au_hinotify *hinotify, __u32 events)
>+{
>+	/* nothing */
>+}
>+
>+static inline int au_inotify_init(void)
>+{
>+	return 0;
>+}
>+
>+#define au_inotify_fin()	do {} while (0)
>+#endif /* CONFIG_AUFS_HINOTIFY */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * au_hdir_lock, au_hdir2_lock
>+ */
>+#define AuLockFunc(name, lsc) \
>+static inline \
>+void name##_lock(struct inode *h_dir, struct inode *dir, aufs_bindex_t bindex) \
>+{ au_do_hdir_lock(h_dir, dir, bindex, AuLsc_I_##lsc); }
>+
>+AuLockFunc(au_hdir, PARENT);
>+AuLockFunc(au_hdir2, PARENT2);
>+
>+#undef AuLockFunc
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_HINODE_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/hin_or_dlgt.c linux-2.6.25.4-unionfs/fs/aufs/hin_or_dlgt.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/hin_or_dlgt.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/hin_or_dlgt.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,708 @@
>+/*
>+ * Copyright (C) 2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * sub-routines for vfs in hinotify or dlgt mode
>+ *
>+ * $Id: hin_or_dlgt.c,v 1.2 2008/04/21 02:00:37 sfjro Exp $
>+ */
>+// I'm going to slightly mad
>+
>+#include <linux/uaccess.h>
>+#include "aufs.h"
>+
>+#if !defined(CONFIG_AUFS_HINOTIFY) && !defined(CONFIG_AUFS_DLGT)
>+#error mis-configuraion or Makefile
>+#endif
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct permission_args {
>+	int *errp;
>+	struct inode *inode;
>+	int mask;
>+	struct nameidata *nd;
>+};
>+
>+static void call_permission(void *args)
>+{
>+	struct permission_args *a = args;
>+	*a->errp = do_vfsub_permission(a->inode, a->mask, a->nd);
>+}
>+
>+int vfsub_permission(struct inode *inode, int mask, struct nameidata *nd,
>+		     int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_permission(inode, mask, nd);
>+	else {
>+		int err, wkq_err;
>+		struct permission_args args = {
>+			.errp	= &err,
>+			.inode	= inode,
>+			.mask	= mask,
>+			.nd	= nd
>+		};
>+		wkq_err = au_wkq_wait(call_permission, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		return err;
>+	}
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct create_args {
>+	int *errp;
>+	struct inode *dir;
>+	struct dentry *dentry;
>+	int mode;
>+	struct nameidata *nd;
>+};
>+
>+static void call_create(void *args)
>+{
>+	struct create_args *a = args;
>+	*a->errp = do_vfsub_create(a->dir, a->dentry, a->mode, a->nd);
>+}
>+
>+int vfsub_create(struct inode *dir, struct dentry *dentry, int mode,
>+		 struct nameidata *nd, int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_create(dir, dentry, mode, nd);
>+	else {
>+		int err, wkq_err;
>+		struct create_args args = {
>+			.errp	= &err,
>+			.dir	= dir,
>+			.dentry	= dentry,
>+			.mode	= mode,
>+			.nd	= nd
>+		};
>+		wkq_err = au_wkq_wait(call_create, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		return err;
>+	}
>+}
>+
>+struct symlink_args {
>+	int *errp;
>+	struct inode *dir;
>+	struct dentry *dentry;
>+	const char *symname;
>+	int mode;
>+};
>+
>+static void call_symlink(void *args)
>+{
>+	struct symlink_args *a = args;
>+	*a->errp = do_vfsub_symlink(a->dir, a->dentry, a->symname, a->mode);
>+}
>+
>+int vfsub_symlink(struct inode *dir, struct dentry *dentry, const char *symname,
>+		  int mode, int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_symlink(dir, dentry, symname, mode);
>+	else {
>+		int err, wkq_err;
>+		struct symlink_args args = {
>+			.errp		= &err,
>+			.dir		= dir,
>+			.dentry		= dentry,
>+			.symname	= symname,
>+			.mode		= mode
>+		};
>+		wkq_err = au_wkq_wait(call_symlink, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		return err;
>+	}
>+}
>+
>+struct mknod_args {
>+	int *errp;
>+	struct inode *dir;
>+	struct dentry *dentry;
>+	int mode;
>+	dev_t dev;
>+};
>+
>+static void call_mknod(void *args)
>+{
>+	struct mknod_args *a = args;
>+	*a->errp = do_vfsub_mknod(a->dir, a->dentry, a->mode, a->dev);
>+}
>+
>+int vfsub_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev,
>+		int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_mknod(dir, dentry, mode, dev);
>+	else {
>+		int err, wkq_err;
>+		struct mknod_args args = {
>+			.errp	= &err,
>+			.dir	= dir,
>+			.dentry	= dentry,
>+			.mode	= mode,
>+			.dev	= dev
>+		};
>+		wkq_err = au_wkq_wait(call_mknod, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		return err;
>+	}
>+}
>+
>+struct mkdir_args {
>+	int *errp;
>+	struct inode *dir;
>+	struct dentry *dentry;
>+	int mode;
>+};
>+
>+static void call_mkdir(void *args)
>+{
>+	struct mkdir_args *a = args;
>+	*a->errp = do_vfsub_mkdir(a->dir, a->dentry, a->mode);
>+}
>+
>+int vfsub_mkdir(struct inode *dir, struct dentry *dentry, int mode, int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_mkdir(dir, dentry, mode);
>+	else {
>+		int err, wkq_err;
>+		struct mkdir_args args = {
>+			.errp	= &err,
>+			.dir	= dir,
>+			.dentry	= dentry,
>+			.mode	= mode
>+		};
>+		wkq_err = au_wkq_wait(call_mkdir, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		return err;
>+	}
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct link_args {
>+	int *errp;
>+	struct inode *dir;
>+	struct dentry *src_dentry, *dentry;
>+};
>+
>+static void call_link(void *args)
>+{
>+	struct link_args *a = args;
>+	*a->errp = do_vfsub_link(a->src_dentry, a->dir, a->dentry);
>+}
>+
>+int vfsub_link(struct dentry *src_dentry, struct inode *dir,
>+	       struct dentry *dentry, int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_link(src_dentry, dir, dentry);
>+	else {
>+		int err, wkq_err;
>+		struct link_args args = {
>+			.errp		= &err,
>+			.src_dentry	= src_dentry,
>+			.dir		= dir,
>+			.dentry		= dentry
>+		};
>+		wkq_err = au_wkq_wait(call_link, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		return err;
>+	}
>+}
>+
>+struct rename_args {
>+	int *errp;
>+	struct inode *src_dir, *dir;
>+	struct dentry *src_dentry, *dentry;
>+	struct vfsub_args *vargs;
>+};
>+
>+static void call_rename(void *args)
>+{
>+	struct rename_args *a = args;
>+	vfsub_ignore(a->vargs);
>+	*a->errp = do_vfsub_rename(a->src_dir, a->src_dentry, a->dir,
>+				   a->dentry);
>+	if (unlikely(*a->errp))
>+		vfsub_unignore(a->vargs);
>+}
>+
>+int vfsub_rename(struct inode *src_dir, struct dentry *src_dentry,
>+		 struct inode *dir, struct dentry *dentry,
>+		 struct vfsub_args *vargs)
>+{
>+	int err;
>+
>+	if (!vfsub_ftest(vargs->flags, DLGT)) {
>+		vfsub_ignore(vargs);
>+		err = do_vfsub_rename(src_dir, src_dentry, dir, dentry);
>+		if (unlikely(err))
>+			vfsub_unignore(vargs);
>+	} else {
>+		int wkq_err;
>+		struct rename_args args = {
>+			.errp		= &err,
>+			.src_dir	= src_dir,
>+			.src_dentry	= src_dentry,
>+			.dir		= dir,
>+			.dentry		= dentry,
>+			.vargs		= vargs
>+		};
>+		wkq_err = au_wkq_wait(call_rename, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+	return err;
>+}
>+
>+struct rmdir_args {
>+	int *errp;
>+	struct inode *dir;
>+	struct dentry *dentry;
>+	struct vfsub_args *vargs;
>+};
>+
>+static void call_rmdir(void *args)
>+{
>+	struct rmdir_args *a = args;
>+	vfsub_ignore(a->vargs);
>+	*a->errp = do_vfsub_rmdir(a->dir, a->dentry);
>+	if (unlikely(*a->errp))
>+		vfsub_unignore(a->vargs);
>+}
>+
>+int vfsub_rmdir(struct inode *dir, struct dentry *dentry,
>+		struct vfsub_args *vargs)
>+{
>+	int err;
>+
>+	if (!vfsub_ftest(vargs->flags, DLGT)) {
>+		vfsub_ignore(vargs);
>+		err = do_vfsub_rmdir(dir, dentry);
>+		if (unlikely(err))
>+			vfsub_unignore(vargs);
>+	} else {
>+		int wkq_err;
>+		struct rmdir_args args = {
>+			.errp	= &err,
>+			.dir	= dir,
>+			.dentry	= dentry,
>+			.vargs	= vargs
>+		};
>+		wkq_err = au_wkq_wait(call_rmdir, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct read_args {
>+	ssize_t *errp;
>+	struct file *file;
>+	union {
>+		void *kbuf;
>+		char __user *ubuf;
>+	};
>+	size_t count;
>+	loff_t *ppos;
>+};
>+
>+static void call_read_k(void *args)
>+{
>+	struct read_args *a = args;
>+	LKTRTrace("%.*s, cnt %lu, pos %Ld\n",
>+		  AuDLNPair(a->file->f_dentry), (unsigned long)a->count,
>+		  *a->ppos);
>+	*a->errp = do_vfsub_read_k(a->file, a->kbuf, a->count, a->ppos);
>+}
>+
>+ssize_t vfsub_read_u(struct file *file, char __user *ubuf, size_t count,
>+		     loff_t *ppos, int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_read_u(file, ubuf, count, ppos);
>+	else {
>+		int wkq_err;
>+		ssize_t err, read;
>+		struct read_args args = {
>+			.errp	= &err,
>+			.file	= file,
>+			.count	= count,
>+			.ppos	= ppos
>+		};
>+
>+		if (unlikely(!count))
>+			return 0;
>+
>+		/*
>+		 * workaround an application bug.
>+		 * generally, read(2) or write(2) may return the value shorter
>+		 * than requested. But many applications don't support it,
>+		 * for example bash.
>+		 */
>+		err = -ENOMEM;
>+		if (args.count > PAGE_SIZE)
>+			args.count = PAGE_SIZE;
>+		args.kbuf = kmalloc(args.count, GFP_TEMPORARY);
>+		if (unlikely(!args.kbuf))
>+			goto out;
>+
>+		read = 0;
>+		do {
>+			wkq_err = au_wkq_wait(call_read_k, &args, /*dlgt*/1);
>+			if (unlikely(wkq_err))
>+				err = wkq_err;
>+			if (unlikely(err > 0
>+				     && copy_to_user(ubuf, args.kbuf, err))) {
>+				err = -EFAULT;
>+				goto out_free;
>+			} else if (!err)
>+				break;
>+			else if (unlikely(err < 0))
>+				goto out_free;
>+			count -= err;
>+			/* do not read too much because of file i/o pointer */
>+			if (count < args.count)
>+				args.count = count;
>+			ubuf += err;
>+			read += err;
>+		} while (count);
>+		smp_mb(); /* flush ubuf */
>+		err = read;
>+
>+	out_free:
>+		kfree(args.kbuf);
>+	out:
>+		return err;
>+	}
>+}
>+
>+ssize_t vfsub_read_k(struct file *file, void *kbuf, size_t count, loff_t *ppos,
>+		     int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_read_k(file, kbuf, count, ppos);
>+	else {
>+		ssize_t err;
>+		int wkq_err;
>+		struct read_args args = {
>+			.errp	= &err,
>+			.file	= file,
>+			.count	= count,
>+			.ppos	= ppos
>+		};
>+		args.kbuf = kbuf;
>+		wkq_err = au_wkq_wait(call_read_k, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		return err;
>+	}
>+}
>+
>+struct write_args {
>+	ssize_t *errp;
>+	struct file *file;
>+	union {
>+		void *kbuf;
>+		const char __user *ubuf;
>+	};
>+	void *buf;
>+	size_t count;
>+	loff_t *ppos;
>+	struct vfsub_args *vargs;
>+};
>+
>+static void call_write_k(void *args)
>+{
>+	struct write_args *a = args;
>+	LKTRTrace("%.*s, cnt %lu, pos %Ld\n",
>+		  AuDLNPair(a->file->f_dentry), (unsigned long)a->count,
>+		  *a->ppos);
>+	vfsub_ignore(a->vargs);
>+	*a->errp = do_vfsub_write_k(a->file, a->kbuf, a->count, a->ppos);
>+	if (unlikely(*a->errp < 0))
>+		vfsub_unignore(a->vargs);
>+}
>+
>+ssize_t vfsub_write_u(struct file *file, const char __user *ubuf, size_t count,
>+		      loff_t *ppos, struct vfsub_args *vargs)
>+{
>+	ssize_t err;
>+
>+	if (!vfsub_ftest(vargs->flags, DLGT)) {
>+		vfsub_ignore(vargs);
>+		err = do_vfsub_write_u(file, ubuf, count, ppos);
>+		if (unlikely(err < 0))
>+			vfsub_unignore(vargs);
>+	} else {
>+		ssize_t written;
>+		int wkq_err;
>+		struct write_args args = {
>+			.errp	= &err,
>+			.file	= file,
>+			.count	= count,
>+			.ppos	= ppos,
>+			.vargs	= vargs
>+		};
>+
>+		if (unlikely(!count))
>+			return 0;
>+
>+		/*
>+		 * workaround an application bug.
>+		 * generally, read(2) or write(2) may return the value shorter
>+		 * than requested. But many applications don't support it,
>+		 * for example bash.
>+		 */
>+		err = -ENOMEM;
>+		if (args.count > PAGE_SIZE)
>+			args.count = PAGE_SIZE;
>+		args.kbuf = kmalloc(args.count, GFP_TEMPORARY);
>+		if (unlikely(!args.kbuf))
>+			goto out;
>+
>+		written = 0;
>+		do {
>+			if (unlikely(copy_from_user(args.kbuf, ubuf,
>+						    args.count))) {
>+				err = -EFAULT;
>+				goto out_free;
>+			}
>+
>+			wkq_err = au_wkq_wait(call_write_k, &args, /*dlgt*/1);
>+			if (unlikely(wkq_err))
>+				err = wkq_err;
>+			if (err > 0) {
>+				count -= err;
>+				if (count < args.count)
>+					args.count = count;
>+				ubuf += err;
>+				written += err;
>+			} else if (!err)
>+				break;
>+			else if (unlikely(err < 0))
>+				goto out_free;
>+		} while (count);
>+		err = written;
>+
>+	out_free:
>+		kfree(args.kbuf);
>+	}
>+ out:
>+	return err;
>+}
>+
>+ssize_t vfsub_write_k(struct file *file, void *kbuf, size_t count, loff_t *ppos,
>+		      struct vfsub_args *vargs)
>+{
>+	ssize_t err;
>+
>+	if (!vfsub_ftest(vargs->flags, DLGT)) {
>+		vfsub_ignore(vargs);
>+		err = do_vfsub_write_k(file, kbuf, count, ppos);
>+		if (unlikely(err < 0))
>+			vfsub_unignore(vargs);
>+	} else {
>+		int wkq_err;
>+		struct write_args args = {
>+			.errp	= &err,
>+			.file	= file,
>+			.count	= count,
>+			.ppos	= ppos,
>+			.vargs	= vargs
>+		};
>+		args.kbuf = kbuf;
>+		wkq_err = au_wkq_wait(call_write_k, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+	return err;
>+}
>+
>+struct readdir_args {
>+	int *errp;
>+	struct file *file;
>+	filldir_t filldir;
>+	void *arg;
>+};
>+
>+static void call_readdir(void *args)
>+{
>+	struct readdir_args *a = args;
>+	*a->errp = do_vfsub_readdir(a->file, a->filldir, a->arg);
>+}
>+
>+int vfsub_readdir(struct file *file, filldir_t filldir, void *arg, int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_readdir(file, filldir, arg);
>+	else {
>+		int err, wkq_err;
>+		struct readdir_args args = {
>+			.errp		= &err,
>+			.file		= file,
>+			.filldir	= filldir,
>+			.arg		= arg
>+		};
>+		wkq_err = au_wkq_wait(call_readdir, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		return err;
>+	}
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct splice_to_args {
>+	long *errp;
>+	struct file *in;
>+	loff_t *ppos;
>+	struct pipe_inode_info *pipe;
>+	size_t len;
>+	unsigned int flags;
>+};
>+
>+static void call_splice_to(void *args)
>+{
>+	struct splice_to_args *a = args;
>+	*a->errp = do_vfsub_splice_to(a->in, a->ppos, a->pipe, a->len,
>+				      a->flags);
>+}
>+
>+long vfsub_splice_to(struct file *in, loff_t *ppos,
>+		     struct pipe_inode_info *pipe, size_t len,
>+		     unsigned int flags, int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_splice_to(in, ppos, pipe, len, flags);
>+	else {
>+		long err;
>+		int wkq_err;
>+		struct splice_to_args args = {
>+			.errp	= &err,
>+			.in	= in,
>+			.ppos	= ppos,
>+			.pipe	= pipe,
>+			.len	= len,
>+			.flags	= flags
>+		};
>+		wkq_err = au_wkq_wait(call_splice_to, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		return err;
>+	}
>+}
>+
>+struct splice_from_args {
>+	long *errp;
>+	struct pipe_inode_info *pipe;
>+	struct file *out;
>+	loff_t *ppos;
>+	size_t len;
>+	unsigned int flags;
>+	struct vfsub_args *vargs;
>+};
>+
>+static void call_splice_from(void *args)
>+{
>+	struct splice_from_args *a = args;
>+	vfsub_ignore(a->vargs);
>+	*a->errp = do_vfsub_splice_from(a->pipe, a->out, a->ppos, a->len,
>+					a->flags);
>+	if (unlikely(*a->errp < 0))
>+		vfsub_unignore(a->vargs);
>+}
>+
>+long vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
>+		       loff_t *ppos, size_t len, unsigned int flags,
>+		       struct vfsub_args *vargs)
>+{
>+	long err;
>+
>+	if (!vfsub_ftest(vargs->flags, DLGT)) {
>+		vfsub_ignore(vargs);
>+		err = do_vfsub_splice_from(pipe, out, ppos, len, flags);
>+		if (unlikely(err < 0))
>+			vfsub_unignore(vargs);
>+	} else {
>+		int wkq_err;
>+		struct splice_from_args args = {
>+			.errp	= &err,
>+			.pipe	= pipe,
>+			.out	= out,
>+			.ppos	= ppos,
>+			.len	= len,
>+			.flags	= flags,
>+			.vargs	= vargs
>+		};
>+		wkq_err = au_wkq_wait(call_splice_from, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct getattr_args {
>+	int *errp;
>+	struct vfsmount *mnt;
>+	struct dentry *dentry;
>+	struct kstat *st;
>+};
>+
>+static void call_getattr(void *args)
>+{
>+	struct getattr_args *a = args;
>+	*a->errp = do_vfsub_getattr(a->mnt, a->dentry, a->st);
>+}
>+
>+int vfsub_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *st,
>+		  int dlgt)
>+{
>+	if (!dlgt)
>+		return do_vfsub_getattr(mnt, dentry, st);
>+	else {
>+		int err, wkq_err;
>+		struct getattr_args args = {
>+			.errp	= &err,
>+			.mnt	= mnt,
>+			.dentry	= dentry,
>+			.st	= st
>+		};
>+		wkq_err = au_wkq_wait(call_getattr, &args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		return err;
>+	}
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/hinotify.c linux-2.6.25.4-unionfs/fs/aufs/hinotify.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/hinotify.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/hinotify.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,1053 @@
>+/*
>+ * Copyright (C) 2006-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * internal/hidden inotify handler
>+ *
>+ * $Id: hinotify.c,v 1.5 2008/05/19 01:49:11 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+/* inotify events */
>+static const __u32 AuInMask = (IN_MOVE | IN_DELETE | IN_CREATE
>+			       /* | IN_ACCESS */
>+			       | IN_MODIFY | IN_ATTRIB
>+			       /* | IN_DELETE_SELF | IN_MOVE_SELF */
>+	);
>+static struct inotify_handle *in_handle;
>+
>+/* the size of an array for ignore counter */
>+static int au_hin_nignore;
>+
>+AuCacheFuncs(hinotify, AuCache_HINOTIFY);
>+
>+int au_hin_alloc(struct au_hinode *hinode, struct inode *inode,
>+		 struct inode *hidden_inode)
>+{
>+	int err, i;
>+	struct au_hinotify *hin;
>+	s32 wd;
>+
>+	LKTRTrace("i%lu, hi%lu\n", inode->i_ino, hidden_inode->i_ino);
>+
>+	err = -ENOMEM;
>+	hin = au_cache_alloc_hinotify();
>+	if (hin) {
>+		AuDebugOn(hinode->hi_notify);
>+		hinode->hi_notify = hin;
>+		hin->hin_aufs_inode = inode;
>+		for (i = 0; i < au_hin_nignore; i++)
>+			atomic_set(hin->hin_ignore + i, 0);
>+
>+		inotify_init_watch(&hin->hin_watch);
>+		wd = inotify_add_watch(in_handle, &hin->hin_watch, hidden_inode,
>+				       AuInMask);
>+		if (wd >= 0)
>+			return 0; /* success */
>+
>+		err = wd;
>+		put_inotify_watch(&hin->hin_watch);
>+		au_cache_free_hinotify(hin);
>+		hinode->hi_notify = NULL;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+void au_hin_free(struct au_hinode *hinode)
>+{
>+	int err;
>+	struct au_hinotify *hin;
>+
>+	AuTraceEnter();
>+
>+	hin = hinode->hi_notify;
>+	if (unlikely(hin)) {
>+		err = 0;
>+		if (atomic_read(&hin->hin_watch.count))
>+			err = inotify_rm_watch(in_handle, &hin->hin_watch);
>+		if (unlikely(err))
>+			/* it means the watch is already removed */
>+			LKTRTrace("failed inotify_rm_watch() %d\n", err);
>+		au_cache_free_hinotify(hin);
>+		hinode->hi_notify = NULL;
>+	}
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static void ctl_hinotify(struct au_hinode *hinode, const __u32 mask)
>+{
>+	struct inode *h_inode;
>+	struct inotify_watch *watch;
>+
>+	h_inode = hinode->hi_inode;
>+	LKTRTrace("hi%lu, sb %p, 0x%x\n", h_inode->i_ino, h_inode->i_sb, mask);
>+	IMustLock(h_inode);
>+	if (!hinode->hi_notify)
>+		return;
>+
>+	watch = &hinode->hi_notify->hin_watch;
>+	/* struct inotify_handle is hidden */
>+	mutex_lock(&h_inode->inotify_mutex);
>+	//mutex_lock(&watch->ih->mutex);
>+	watch->mask = mask;
>+	//mutex_unlock(&watch->ih->mutex);
>+	mutex_unlock(&h_inode->inotify_mutex);
>+	LKTRTrace("watch %p, mask %u\n", watch, watch->mask);
>+}
>+
>+#define suspend_hinotify(hi)	ctl_hinotify(hi, 0)
>+#define resume_hinotify(hi)	ctl_hinotify(hi, AuInMask)
>+
>+void au_do_hdir_lock(struct inode *h_dir, struct inode *dir,
>+		     aufs_bindex_t bindex, unsigned int lsc)
>+{
>+	struct au_hinode *hinode;
>+
>+	LKTRTrace("i%lu, b%d, lsc %d\n", dir->i_ino, bindex, lsc);
>+	AuDebugOn(!S_ISDIR(dir->i_mode));
>+	hinode = au_ii(dir)->ii_hinode + bindex;
>+	AuDebugOn(h_dir != hinode->hi_inode);
>+
>+	mutex_lock_nested(&h_dir->i_mutex, lsc);
>+	suspend_hinotify(hinode);
>+}
>+
>+void au_hdir_unlock(struct inode *h_dir, struct inode *dir,
>+		    aufs_bindex_t bindex)
>+{
>+	struct au_hinode *hinode;
>+
>+	LKTRTrace("i%lu, b%d\n", dir->i_ino, bindex);
>+	AuDebugOn(!S_ISDIR(dir->i_mode));
>+	hinode = au_ii(dir)->ii_hinode + bindex;
>+	AuDebugOn(h_dir != hinode->hi_inode);
>+
>+	resume_hinotify(hinode);
>+	mutex_unlock(&h_dir->i_mutex);
>+}
>+
>+struct dentry *au_hdir_lock_rename(struct dentry **h_parents,
>+				   struct inode **dirs, aufs_bindex_t bindex,
>+				   int issamedir)
>+{
>+	struct dentry *h_trap;
>+	struct au_hinode *hinode;
>+
>+	LKTRTrace("%.*s, %.*s\n",
>+		  AuDLNPair(h_parents[0]), AuDLNPair(h_parents[1]));
>+
>+	h_trap = vfsub_lock_rename(h_parents[0], h_parents[1]);
>+	hinode = au_ii(dirs[0])->ii_hinode + bindex;
>+	AuDebugOn(h_parents[0]->d_inode != hinode->hi_inode);
>+	suspend_hinotify(hinode);
>+	if (!issamedir) {
>+		hinode = au_ii(dirs[1])->ii_hinode + bindex;
>+		AuDebugOn(h_parents[1]->d_inode != hinode->hi_inode);
>+		suspend_hinotify(hinode);
>+	}
>+
>+	return h_trap;
>+}
>+
>+void au_hdir_unlock_rename(struct dentry **h_parents, struct inode **dirs,
>+			   aufs_bindex_t bindex, int issamedir)
>+{
>+	struct au_hinode *hinode;
>+
>+	LKTRTrace("%.*s, %.*s\n",
>+		  AuDLNPair(h_parents[0]), AuDLNPair(h_parents[1]));
>+
>+	hinode = au_ii(dirs[0])->ii_hinode + bindex;
>+	AuDebugOn(h_parents[0]->d_inode != hinode->hi_inode);
>+	resume_hinotify(hinode);
>+	if (!issamedir) {
>+		hinode = au_ii(dirs[1])->ii_hinode + bindex;
>+		AuDebugOn(h_parents[1]->d_inode != hinode->hi_inode);
>+		resume_hinotify(hinode);
>+	}
>+	vfsub_unlock_rename(h_parents[0], h_parents[1]);
>+}
>+
>+void au_reset_hinotify(struct inode *inode, unsigned int flags)
>+{
>+	aufs_bindex_t bindex, bend;
>+	struct inode *hi;
>+	struct dentry *iwhdentry;
>+
>+	LKTRTrace("i%lu, 0x%x\n", inode->i_ino, flags);
>+
>+	bend = au_ibend(inode);
>+	for (bindex = au_ibstart(inode); bindex <= bend; bindex++) {
>+		hi = au_h_iptr(inode, bindex);
>+		if (hi) {
>+			//mutex_lock_nested(&hi->i_mutex, AuLsc_I_CHILD);
>+			iwhdentry = au_hi_wh(inode, bindex);
>+			if (unlikely(iwhdentry))
>+				dget(iwhdentry);
>+			igrab(hi);
>+			au_set_h_iptr(inode, bindex, NULL, 0);
>+			au_set_h_iptr(inode, bindex, igrab(hi),
>+				      flags & ~AuHi_XINO);
>+			iput(hi);
>+			dput(iwhdentry);
>+			//mutex_unlock(&hi->i_mutex);
>+		}
>+	}
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* cf. fsnotify_change() */
>+__u32 vfsub_events_notify_change(struct iattr *ia)
>+{
>+	__u32 events;
>+	const unsigned int amtime = (ATTR_ATIME | ATTR_MTIME);
>+
>+	events = 0;
>+	if ((ia->ia_valid & (ATTR_UID | ATTR_GID | ATTR_MODE))
>+	    || (ia->ia_valid & amtime) == amtime)
>+		events |= IN_ATTRIB;
>+	if ((ia->ia_valid & ATTR_SIZE)
>+	    || (ia->ia_valid & amtime) == ATTR_MTIME)
>+		events |= IN_MODIFY;
>+	return events;
>+}
>+
>+void vfsub_ign_hinode(struct vfsub_args *vargs, __u32 events,
>+		      struct au_hinode *hinode)
>+{
>+	struct au_hin_ignore *ign;
>+
>+	AuDebugOn(!hinode);
>+
>+	ign = vargs->ignore + vargs->nignore++;
>+	ign->ign_events = events;
>+	ign->ign_hinode = hinode;
>+}
>+
>+void vfsub_ignore(struct vfsub_args *vargs)
>+{
>+	int n;
>+	struct au_hin_ignore *ign;
>+
>+	n = vargs->nignore;
>+	ign = vargs->ignore;
>+	while (n-- > 0) {
>+		au_hin_ignore(ign->ign_hinode, ign->ign_events);
>+		ign++;
>+	}
>+}
>+
>+void vfsub_unignore(struct vfsub_args *vargs)
>+{
>+	int n;
>+	struct au_hin_ignore *ign;
>+
>+	n = vargs->nignore;
>+	ign = vargs->ignore;
>+	while (n-- > 0) {
>+		au_hin_unignore(ign->ign_hinode, ign->ign_events);
>+		ign++;
>+	}
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void au_hin_ignore(struct au_hinode *hinode, __u32 events)
>+{
>+	int i;
>+	atomic_t *ign;
>+
>+	LKTRTrace("0x%x\n", events);
>+	AuDebugOn(!hinode || !events);
>+	if (unlikely(!hinode->hi_inode || !hinode->hi_notify)) {
>+		/*
>+		 * it may happen by this scenario.
>+		 * - a file and its parent dir exist on two branches
>+		 * - a file on the upper branch is opened
>+		 * - the parent dir and the file are removed by udba
>+		 * - the parent is re-accessed, and new dentry/inode in
>+		 *   aufs is generated for it, based upon the one on the lower
>+		 *   branch
>+		 * - the opened file is re-accessed, re-validated, and it may be
>+		 *   re-connected to the new parent dentry
>+		 * it means the file in aufs cannot get the actual removed
>+		 * parent dir on the branch.
>+		 */
>+		return;
>+	}
>+	LKTRTrace("hi%lu\n", hinode->hi_inode->i_ino);
>+#ifdef DbgInotify
>+	AuDbg("hi%lu, 0x%x\n", hinode->hi_inode->i_ino, events);
>+#endif
>+	AuDebugOn(!hinode->hi_notify);
>+
>+	ign = hinode->hi_notify->hin_ignore;
>+	for (i = 0; i < au_hin_nignore; i++)
>+		if (1U << i & events)
>+			atomic_inc_return(ign + i);
>+}
>+
>+void au_hin_unignore(struct au_hinode *hinode, __u32 events)
>+{
>+	int i;
>+	atomic_t *ign;
>+
>+	LKTRTrace("0x%x\n", events);
>+	AuDebugOn(!hinode || !events);
>+	if (unlikely(!hinode->hi_inode || !hinode->hi_notify))
>+		return;
>+	LKTRTrace("hi%lu\n", hinode->hi_inode->i_ino);
>+#ifdef DbgInotify
>+	AuDbg("hi%lu, 0x%x\n", hinode->hi_inode->i_ino, events);
>+#endif
>+	AuDebugOn(!hinode->hi_notify);
>+
>+	ign = hinode->hi_notify->hin_ignore;
>+	for (i = 0; i < au_hin_nignore; i++)
>+		if (1U << i & events)
>+			atomic_dec_return(ign + i);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static char *in_name(u32 mask)
>+{
>+#ifdef CONFIG_AUFS_DEBUG
>+#define test_ret(flag)	if (mask & flag) return #flag;
>+	test_ret(IN_ACCESS);
>+	test_ret(IN_MODIFY);
>+	test_ret(IN_ATTRIB);
>+	test_ret(IN_CLOSE_WRITE);
>+	test_ret(IN_CLOSE_NOWRITE);
>+	test_ret(IN_OPEN);
>+	test_ret(IN_MOVED_FROM);
>+	test_ret(IN_MOVED_TO);
>+	test_ret(IN_CREATE);
>+	test_ret(IN_DELETE);
>+	test_ret(IN_DELETE_SELF);
>+	test_ret(IN_MOVE_SELF);
>+	test_ret(IN_UNMOUNT);
>+	test_ret(IN_Q_OVERFLOW);
>+	test_ret(IN_IGNORED);
>+	return "";
>+#undef test_ret
>+#else
>+	return "??";
>+#endif
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static struct dentry *lookup_wlock_by_name(char *name, unsigned int nlen,
>+					   struct inode *dir)
>+{
>+	struct dentry *dentry, *d, *parent;
>+	struct qstr *dname;
>+
>+	LKTRTrace("%.*s, dir%lu\n", nlen, name, dir->i_ino);
>+
>+	parent = d_find_alias(dir);
>+	if (!parent)
>+		return NULL;
>+
>+	dentry = NULL;
>+	spin_lock(&dcache_lock);
>+	list_for_each_entry(d, &parent->d_subdirs, d_u.d_child) {
>+		LKTRTrace("%.*s\n", AuDLNPair(d));
>+		dname = &d->d_name;
>+		if (dname->len != nlen || memcmp(dname->name, name, nlen))
>+			continue;
>+		if (!atomic_read(&d->d_count)) {
>+			spin_lock(&d->d_lock);
>+			__d_drop(d);
>+			spin_unlock(&d->d_lock);
>+			continue;
>+		}
>+
>+		dentry = dget(d);
>+		break;
>+	}
>+	spin_unlock(&dcache_lock);
>+	dput(parent);
>+
>+	if (dentry)
>+		di_write_lock_child(dentry);
>+	return dentry;
>+}
>+
>+static struct inode *lookup_wlock_by_ino(struct super_block *sb,
>+					 aufs_bindex_t bindex, ino_t h_ino)
>+{
>+	struct inode *inode;
>+	struct au_xino_entry xinoe;
>+	int err;
>+
>+	LKTRTrace("b%d, hi%lu\n", bindex, h_ino);
>+	AuDebugOn(!au_opt_test(au_mntflags(sb), XINO));
>+
>+	inode = NULL;
>+	err = au_xino_read(sb, bindex, h_ino, &xinoe);
>+	if (!err && xinoe.ino)
>+		inode = ilookup(sb, xinoe.ino);
>+	if (!inode)
>+		goto out;
>+	if (unlikely(inode->i_ino == AUFS_ROOT_INO)) {
>+		AuWarn("wrong root branch\n");
>+		iput(inode);
>+		inode = NULL;
>+		goto out;
>+	}
>+
>+	ii_write_lock_child(inode);
>+
>+ out:
>+	return inode;
>+}
>+
>+static int hin_xino(struct inode *inode, struct inode *h_inode)
>+{
>+	int err;
>+	aufs_bindex_t bindex, bend, bfound, bstart;
>+	struct inode *h_i;
>+
>+	LKTRTrace("i%lu, hi%lu\n", inode->i_ino, h_inode->i_ino);
>+
>+	err = 0;
>+	if (unlikely(inode->i_ino == AUFS_ROOT_INO)) {
>+		AuWarn("branch root dir was changed\n");
>+		goto out;
>+	}
>+
>+	bfound = -1;
>+	bend = au_ibend(inode);
>+	bstart = au_ibstart(inode);
>+	for (bindex = bstart; bindex <= bend; bindex++) {
>+		if (au_h_iptr(inode, bindex) == h_inode) {
>+			bfound = bindex;
>+			break;
>+		}
>+	}
>+	if (bfound < 0)
>+		goto out;
>+
>+	for (bindex = bstart; bindex <= bend; bindex++) {
>+		h_i = au_h_iptr(inode, bindex);
>+		if (h_i)
>+			err = au_xino_write0(inode->i_sb, bindex, h_i->i_ino,
>+					     0);
>+		/* ignore this error */
>+		/* bad action? */
>+	}
>+
>+	/* children inode number will be broken */
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int hin_gen_tree(struct dentry *dentry)
>+{
>+	int err, i, j, ndentry;
>+	struct au_dcsub_pages dpages;
>+	struct au_dpage *dpage;
>+	struct dentry **dentries;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	err = au_dpages_init(&dpages, GFP_TEMPORARY);
>+	if (unlikely(err))
>+		goto out;
>+	err = au_dcsub_pages(&dpages, dentry, NULL, NULL);
>+	if (unlikely(err))
>+		goto out_dpages;
>+
>+	for (i = 0; i < dpages.ndpage; i++) {
>+		dpage = dpages.dpages + i;
>+		dentries = dpage->dentries;
>+		ndentry = dpage->ndentry;
>+		for (j = 0; j < ndentry; j++) {
>+			struct dentry *d;
>+			d = dentries[j];
>+			LKTRTrace("%.*s\n", AuDLNPair(d));
>+			if (IS_ROOT(d))
>+				continue;
>+
>+			d_drop(d);
>+			au_digen_dec(d);
>+			if (d->d_inode)
>+				//reset children xino? cached children only?
>+				au_iigen_dec(d->d_inode);
>+		}
>+	}
>+
>+ out_dpages:
>+	au_dpages_free(&dpages);
>+
>+	/* discard children */
>+	dentry_unhash(dentry);
>+	dput(dentry);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * return 0 if processed.
>+ */
>+static int hin_gen_by_inode(char *name, unsigned int nlen, struct inode *inode,
>+			    const unsigned int isdir)
>+{
>+	int err;
>+	struct dentry *d;
>+	struct qstr *dname;
>+
>+	LKTRTrace("%.*s, i%lu\n", nlen, name, inode->i_ino);
>+
>+	err = 1;
>+	if (unlikely(inode->i_ino == AUFS_ROOT_INO)) {
>+		AuWarn("branch root dir was changed\n");
>+		err = 0;
>+		goto out;
>+	}
>+
>+	if (!isdir) {
>+		AuDebugOn(!name);
>+		au_iigen_dec(inode);
>+		spin_lock(&dcache_lock);
>+		list_for_each_entry(d, &inode->i_dentry, d_alias) {
>+			dname = &d->d_name;
>+			if (dname->len != nlen
>+			    && memcmp(dname->name, name, nlen))
>+				continue;
>+			err = 0;
>+			spin_lock(&d->d_lock);
>+			__d_drop(d);
>+			au_digen_dec(d);
>+			spin_unlock(&d->d_lock);
>+			break;
>+		}
>+		spin_unlock(&dcache_lock);
>+	} else {
>+		au_fset_si(au_sbi(inode->i_sb), FAILED_REFRESH_DIRS);
>+		d = d_find_alias(inode);
>+		if (!d) {
>+			au_iigen_dec(inode);
>+			goto out;
>+		}
>+
>+		dname = &d->d_name;
>+		if (dname->len == nlen && !memcmp(dname->name, name, nlen))
>+			err = hin_gen_tree(d);
>+		dput(d);
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int hin_gen_by_name(struct dentry *dentry, const unsigned int isdir)
>+{
>+	int err;
>+	struct inode *inode;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	inode = dentry->d_inode;
>+	if (IS_ROOT(dentry)
>+	    //|| (inode && inode->i_ino == AUFS_ROOT_INO)
>+		) {
>+		AuWarn("branch root dir was changed\n");
>+		return 0;
>+	}
>+
>+	err = 0;
>+	if (!isdir) {
>+		d_drop(dentry);
>+		au_digen_dec(dentry);
>+		if (inode)
>+			au_iigen_dec(inode);
>+	} else {
>+		au_fset_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIRS);
>+		if (inode)
>+			err = hin_gen_tree(dentry);
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static void hin_attr(struct inode *inode, struct inode *h_inode)
>+{
>+	struct dentry *h_dentry;
>+
>+	LKTRTrace("i%lu, hi%lu\n", inode->i_ino, h_inode->i_ino);
>+
>+	if (au_h_iptr(inode, au_ibstart(inode)) != h_inode)
>+		return;
>+
>+	h_dentry = d_find_alias(h_inode);
>+	if (h_dentry) {
>+		au_update_fuse_h_inode(NULL, h_dentry);
>+		/* ignore an error*/
>+		dput(h_dentry);
>+	}
>+
>+	au_cpup_attr_all(inode);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* hinotify job flags */
>+#define AuHinJob_XINO0	1
>+#define AuHinJob_GEN	(1 << 1)
>+#define AuHinJob_DIRENT	(1 << 2)
>+#define AuHinJob_ATTR	(1 << 3)
>+#define AuHinJob_ISDIR	(1 << 4)
>+#define AuHinJob_TRYXINO0 (1 << 5)
>+#define AuHinJob_MNTPNT	(1 << 6)
>+#define au_ftest_hinjob(flags, name)	((flags) & AuHinJob_##name)
>+#define au_fset_hinjob(flags, name)	{ (flags) |= AuHinJob_##name; }
>+#define au_fclr_hinjob(flags, name)	{ (flags) &= ~AuHinJob_##name; }
>+
>+struct hin_job_args {
>+	unsigned int flags;
>+	struct inode *inode, *h_inode, *dir, *h_dir;
>+	struct dentry *dentry;
>+	char *h_name;
>+	int h_nlen;
>+};
>+
>+static int hin_job(struct hin_job_args *a)
>+{
>+	const unsigned int isdir = au_ftest_hinjob(a->flags, ISDIR);
>+
>+	/* reset xino */
>+	if (au_ftest_hinjob(a->flags, XINO0) && a->inode)
>+		hin_xino(a->inode, a->h_inode);
>+	/* ignore this error */
>+
>+	if (au_ftest_hinjob(a->flags, TRYXINO0)
>+	    && a->inode
>+	    && a->h_inode) {
>+		mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
>+		if (!a->h_inode->i_nlink)
>+			hin_xino(a->inode, a->h_inode);
>+		/* ignore this error */
>+		mutex_unlock(&a->h_inode->i_mutex);
>+	}
>+
>+	/* make the generation obsolete */
>+	if (au_ftest_hinjob(a->flags, GEN)) {
>+		int err = -1;
>+		if (a->inode)
>+			err = hin_gen_by_inode(a->h_name, a->h_nlen, a->inode,
>+					       isdir);
>+		if (err && a->dentry)
>+			hin_gen_by_name(a->dentry, isdir);
>+		/* ignore this error */
>+	}
>+
>+	/* make dir entries obsolete */
>+	if (au_ftest_hinjob(a->flags, DIRENT) && a->inode) {
>+		struct au_vdir *vdir;
>+		IiMustWriteLock(a->inode);
>+		vdir = au_ivdir(a->inode);
>+		if (vdir)
>+			vdir->vd_jiffy = 0;
>+		//IMustLock(a->inode);
>+		//a->inode->i_version++;
>+	}
>+
>+	/* update the attr */
>+	if (au_ftest_hinjob(a->flags, ATTR) && a->inode && a->h_inode)
>+		hin_attr(a->inode, a->h_inode);
>+
>+	/* can do nothing but warn */
>+	if (au_ftest_hinjob(a->flags, MNTPNT)
>+	    && a->dentry
>+	    && d_mountpoint(a->dentry))
>+		AuWarn("mount-point %.*s is removed or renamed\n",
>+		       AuDLNPair(a->dentry));
>+
>+	return 0;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+enum { CHILD, PARENT };
>+struct postproc_args {
>+	struct inode *h_dir, *dir, *h_child_inode;
>+	u32 mask;
>+	unsigned int flags[2];
>+	unsigned int h_child_nlen;
>+	char h_child_name[];
>+};
>+
>+static void postproc(void *_args)
>+{
>+	struct postproc_args *a = _args;
>+	struct super_block *sb;
>+	aufs_bindex_t bindex, bend, bfound;
>+	int xino, err;
>+	struct inode *inode;
>+	ino_t h_ino;
>+	struct hin_job_args args;
>+	struct dentry *dentry;
>+	struct au_sbinfo *sbinfo;
>+
>+	AuDebugOn(!_args);
>+	AuDebugOn(!a->h_dir);
>+	AuDebugOn(!a->dir);
>+	AuDebugOn(!a->mask);
>+	//au_debug_on();
>+	LKTRTrace("mask 0x%x %s, i%lu, hi%lu, hci%lu\n",
>+		  a->mask, in_name(a->mask), a->dir->i_ino, a->h_dir->i_ino,
>+		  a->h_child_inode ? a->h_child_inode->i_ino : 0);
>+
>+	inode = NULL;
>+	dentry = NULL;
>+	// do not lock here because of d_revalidate() may cause a deadlock.
>+	//mutex_lock(&a->dir->i_mutex);
>+	sb = a->dir->i_sb;
>+	AuDebugOn(!sb);
>+	sbinfo = au_sbi(sb);
>+	AuDebugOn(!sbinfo);
>+	/* big aufs lock */
>+	si_noflush_write_lock(sb);
>+
>+	ii_read_lock_parent(a->dir);
>+	bfound = -1;
>+	bend = au_ibend(a->dir);
>+	for (bindex = au_ibstart(a->dir); bindex <= bend; bindex++)
>+		if (au_h_iptr(a->dir, bindex) == a->h_dir) {
>+			bfound = bindex;
>+			break;
>+		}
>+	ii_read_unlock(a->dir);
>+	if (unlikely(bfound < 0))
>+		goto out;
>+
>+	xino = !!au_opt_test(au_mntflags(sb), XINO);
>+	h_ino = 0;
>+	if (a->h_child_inode)
>+		h_ino = a->h_child_inode->i_ino;
>+	//AuDbg("here\n");
>+
>+	if (a->h_child_nlen
>+	    && (au_ftest_hinjob(a->flags[CHILD], GEN)
>+		|| au_ftest_hinjob(a->flags[CHILD], MNTPNT)))
>+		dentry = lookup_wlock_by_name(a->h_child_name, a->h_child_nlen,
>+					      a->dir);
>+	//AuDbg("here\n");
>+	if (dentry)
>+		inode = dentry->d_inode;
>+	if (xino && !inode && h_ino
>+	    && (au_ftest_hinjob(a->flags[CHILD], XINO0)
>+		|| au_ftest_hinjob(a->flags[CHILD], TRYXINO0)
>+		|| au_ftest_hinjob(a->flags[CHILD], GEN)
>+		|| au_ftest_hinjob(a->flags[CHILD], ATTR)))
>+		inode = lookup_wlock_by_ino(sb, bfound, h_ino);
>+	//AuDbg("here\n");
>+
>+	args.flags = a->flags[CHILD];
>+	args.dentry = dentry;
>+	args.inode = inode;
>+	args.h_inode = a->h_child_inode;
>+	args.dir = a->dir;
>+	args.h_dir = a->h_dir;
>+	args.h_name = a->h_child_name;
>+	args.h_nlen = a->h_child_nlen;
>+	err = hin_job(&args);
>+	if (dentry) {
>+		di_write_unlock(dentry);
>+		dput(dentry);
>+	} else if (inode) {
>+		ii_write_unlock(inode);
>+		iput(inode);
>+	}
>+	//AuDbg("here\n");
>+
>+	ii_write_lock_parent(a->dir);
>+	args.flags = a->flags[PARENT];
>+	args.dentry = NULL;
>+	args.inode = a->dir;
>+	args.h_inode = a->h_dir;
>+	args.dir = NULL;
>+	args.h_dir = NULL;
>+	args.h_name = NULL;
>+	args.h_nlen = 0;
>+	err = hin_job(&args);
>+	ii_write_unlock(a->dir);
>+	//AuDbg("here\n");
>+
>+ out:
>+	si_write_unlock(sb);
>+	//mutex_unlock(&a->dir->i_mutex);
>+	au_nwt_dec(&sbinfo->si_nowait);
>+
>+	iput(a->h_child_inode);
>+	iput(a->h_dir);
>+	iput(a->dir);
>+	kfree(a);
>+	//au_debug_off();
>+}
>+
>+//todo: endian?
>+#ifndef ilog2
>+#define ilog2(n) ffz(~(n))
>+#endif
>+
>+static void aufs_inotify(struct inotify_watch *watch, u32 wd, u32 mask,
>+			 u32 cookie, const char *h_child_name,
>+			 struct inode *h_child_inode)
>+{
>+	struct au_hinotify *hinotify;
>+	struct postproc_args *args;
>+	int len, wkq_err, isdir, isroot, wh, idx;
>+	char *p;
>+	struct inode *dir;
>+	unsigned int flags[2];
>+	struct super_block *sb;
>+	atomic_t *cnt;
>+
>+	LKTRTrace("i%lu, wd %d, mask 0x%x %s, cookie 0x%x, hcname %s, hi%lu\n",
>+		  watch->inode->i_ino, wd, mask, in_name(mask), cookie,
>+		  h_child_name ? h_child_name : "",
>+		  h_child_inode ? h_child_inode->i_ino : 0);
>+	/* if IN_UNMOUNT happens, there must be another bug */
>+	if (mask & (IN_IGNORED | IN_UNMOUNT)) {
>+		//WARN_ON(watch->inode->i_ino == 15);
>+		put_inotify_watch(watch);
>+		return;
>+	}
>+
>+#ifdef DbgInotify
>+	if (!h_child_name || strcmp(h_child_name, AUFS_XINO_FNAME))
>+		AuDbg("i%lu, wd %d, mask 0x%x %s, cookie 0x%x, hcname %s,"
>+		      " hi%lu\n",
>+		      watch->inode->i_ino, wd, mask, in_name(mask), cookie,
>+		      h_child_name ? h_child_name : "",
>+		      h_child_inode ? h_child_inode->i_ino : 0);
>+	//WARN_ON(1);
>+#endif
>+
>+	hinotify = container_of(watch, struct au_hinotify, hin_watch);
>+	AuDebugOn(!hinotify || !hinotify->hin_aufs_inode);
>+	idx = ilog2(mask & IN_ALL_EVENTS);
>+	AuDebugOn(au_hin_nignore <= idx);
>+	cnt = hinotify->hin_ignore + idx;
>+	if (0 <= atomic_dec_return(cnt))
>+		return;
>+	atomic_inc_return(cnt);
>+
>+	dir = igrab(hinotify->hin_aufs_inode);
>+	if (!dir)
>+		return;
>+	isroot = (dir->i_ino == AUFS_ROOT_INO);
>+	len = 0;
>+	wh = 0;
>+	if (h_child_name) {
>+		len = strlen(h_child_name);
>+		if (!memcmp(h_child_name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
>+			h_child_name += AUFS_WH_PFX_LEN;
>+			len -= AUFS_WH_PFX_LEN;
>+			wh = 1;
>+		}
>+	}
>+
>+	isdir = 0;
>+	if (h_child_inode)
>+		isdir = !!S_ISDIR(h_child_inode->i_mode);
>+	flags[PARENT] = AuHinJob_ISDIR;
>+	flags[CHILD] = 0;
>+	if (isdir)
>+		flags[CHILD] = AuHinJob_ISDIR;
>+	switch (mask & IN_ALL_EVENTS) {
>+	case IN_MODIFY:
>+		/*FALLTHROUGH*/
>+	case IN_ATTRIB:
>+		if (h_child_inode) {
>+			if (!wh)
>+				au_fset_hinjob(flags[CHILD], ATTR);
>+		} else
>+			au_fset_hinjob(flags[PARENT], ATTR);
>+		break;
>+
>+		/* IN_MOVED_FROM is the first event in rename(2) */
>+	case IN_MOVED_FROM:
>+	case IN_MOVED_TO:
>+		AuDebugOn(!h_child_name || !h_child_inode);
>+		au_fset_hinjob(flags[CHILD], GEN);
>+		au_fset_hinjob(flags[CHILD], ATTR);
>+		if (1 || isdir)
>+			au_fset_hinjob(flags[CHILD], XINO0);
>+		au_fset_hinjob(flags[CHILD], MNTPNT);
>+
>+		au_fset_hinjob(flags[PARENT], ATTR);
>+		au_fset_hinjob(flags[PARENT], DIRENT);
>+		break;
>+
>+	case IN_CREATE:
>+		AuDebugOn(!h_child_name || !h_child_inode);
>+		au_fset_hinjob(flags[PARENT], ATTR);
>+		au_fset_hinjob(flags[PARENT], DIRENT);
>+		au_fset_hinjob(flags[CHILD], GEN);
>+		/* hard link */
>+		if (!isdir && h_child_inode->i_nlink > 1)
>+			au_fset_hinjob(flags[CHILD], ATTR);
>+		break;
>+
>+	case IN_DELETE:
>+		/*
>+		 * aufs never be able to get this child inode.
>+		 * revalidation should be in d_revalidate()
>+		 * by checking i_nlink, i_generation or d_unhashed().
>+		 */
>+		AuDebugOn(!h_child_name);
>+		au_fset_hinjob(flags[PARENT], ATTR);
>+		au_fset_hinjob(flags[PARENT], DIRENT);
>+		au_fset_hinjob(flags[CHILD], GEN);
>+		au_fset_hinjob(flags[CHILD], TRYXINO0);
>+		au_fset_hinjob(flags[CHILD], MNTPNT);
>+		break;
>+
>+	case IN_DELETE_SELF:
>+		if (!isroot)
>+			au_fset_hinjob(flags[PARENT], GEN);
>+		/*FALLTHROUGH*/
>+
>+	case IN_MOVE_SELF:
>+		/*
>+		 * when an inotify is set to an aufs inode,
>+		 * such inode can be isolated and this event can be fired
>+		 * solely.
>+		 */
>+		AuDebugOn(h_child_name || h_child_inode);
>+		if (unlikely(isroot)) {
>+			AuWarn("root branch was moved\n");
>+			iput(dir);
>+			return;
>+		}
>+		au_fset_hinjob(flags[PARENT], XINO0);
>+		au_fset_hinjob(flags[PARENT], GEN);
>+		au_fset_hinjob(flags[PARENT], ATTR);
>+		au_fset_hinjob(flags[PARENT], DIRENT);
>+		//au_fset_hinjob(flags[PARENT], MNTPNT);
>+		break;
>+	case IN_ACCESS:
>+	default:
>+		AuDebugOn(1);
>+	}
>+
>+	if (wh)
>+		h_child_inode = NULL;
>+
>+	/* iput() and kfree() will be called in postproc() */
>+	/*
>+	 * inotify_mutex is already acquired and kmalloc/prune_icache may lock
>+	 * iprune_mutex. strange.
>+	 */
>+	lockdep_off();
>+	args = kmalloc(sizeof(*args) + len + 1, GFP_TEMPORARY);
>+	lockdep_on();
>+	if (unlikely(!args)) {
>+		AuErr1("no memory\n");
>+		iput(dir);
>+		return;
>+	}
>+	args->flags[PARENT] = flags[PARENT];
>+	args->flags[CHILD] = flags[CHILD];
>+	args->mask = mask;
>+	args->dir = dir;
>+	args->h_dir = igrab(watch->inode);
>+	if (h_child_inode)
>+		igrab(h_child_inode);
>+	args->h_child_inode = h_child_inode;
>+	args->h_child_nlen = len;
>+	if (len) {
>+		p = (void *)args;
>+		p += sizeof(*args);
>+		memcpy(p, h_child_name, len + 1);
>+	}
>+
>+	sb = dir->i_sb;
>+	au_nwt_inc(&au_sbi(sb)->si_nowait);
>+	lockdep_off();
>+	wkq_err = au_wkq_nowait(postproc, args, sb, /*dlgt*/0);
>+	lockdep_on();
>+	if (unlikely(wkq_err)) {
>+		AuErr("wkq %d\n", wkq_err);
>+		au_nwt_dec(&au_sbi(sb)->si_nowait);
>+	}
>+}
>+
>+static void aufs_inotify_destroy(struct inotify_watch *watch)
>+{
>+	return;
>+}
>+
>+static struct inotify_operations aufs_inotify_ops = {
>+	.handle_event	= aufs_inotify,
>+	.destroy_watch	= aufs_inotify_destroy
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static void au_hin_destroy_cache(void)
>+{
>+	kmem_cache_destroy(au_cachep[AuCache_HINOTIFY]);
>+	au_cachep[AuCache_HINOTIFY] = NULL;
>+}
>+
>+int __init au_inotify_init(void)
>+{
>+	au_hin_nignore = 6;
>+	while (1U << au_hin_nignore < AuInMask)
>+		au_hin_nignore++;
>+	//AuDbg("au_hin_nignore %d\n", au_hin_nignore);
>+	AuDebugOn(au_hin_nignore != 10);
>+
>+	in_handle = ERR_PTR(-ENOMEM);
>+	au_cachep[AuCache_HINOTIFY]
>+		= AuCacheX(au_hinotify, sizeof(atomic_t) * au_hin_nignore);
>+	if (unlikely(!au_cachep[AuCache_HINOTIFY]))
>+		goto out;
>+
>+	in_handle = inotify_init(&aufs_inotify_ops);
>+	if (!IS_ERR(in_handle))
>+		return 0;
>+
>+	au_hin_destroy_cache();
>+ out:
>+	AuTraceErrPtr(in_handle);
>+	return PTR_ERR(in_handle);
>+}
>+
>+void au_inotify_fin(void)
>+{
>+	inotify_destroy(in_handle);
>+	if (au_cachep[AuCache_HINOTIFY])
>+		au_hin_destroy_cache();
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/iinfo.c linux-2.6.25.4-unionfs/fs/aufs/iinfo.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/iinfo.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/iinfo.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,282 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * inode private data
>+ *
>+ * $Id: iinfo.c,v 1.2 2008/04/21 01:32:05 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+struct au_iinfo *au_ii(struct inode *inode)
>+{
>+	struct au_iinfo *iinfo;
>+
>+	iinfo = &(container_of(inode, struct aufs_icntnr, vfs_inode)->iinfo);
>+	/* bad_inode case */
>+	if (unlikely(!iinfo->ii_hinode))
>+		return NULL;
>+	AuDebugOn(!iinfo->ii_hinode
>+		  /* || au_sbi(inode->i_sb)->si_bend < iinfo->ii_bend */
>+		  || iinfo->ii_bend < iinfo->ii_bstart);
>+	return iinfo;
>+}
>+
>+struct inode *au_h_iptr(struct inode *inode, aufs_bindex_t bindex)
>+{
>+	struct inode *hidden_inode;
>+
>+	IiMustAnyLock(inode);
>+	AuDebugOn(bindex < 0 || au_ibend(inode) < bindex);
>+	hidden_inode = au_ii(inode)->ii_hinode[0 + bindex].hi_inode;
>+	AuDebugOn(hidden_inode && atomic_read(&hidden_inode->i_count) <= 0);
>+	return hidden_inode;
>+}
>+
>+aufs_bindex_t au_ii_br_id(struct inode *inode, aufs_bindex_t bindex)
>+{
>+	IiMustAnyLock(inode);
>+	AuDebugOn(bindex < 0
>+		  || au_ibend(inode) < bindex
>+		  || !au_ii(inode)->ii_hinode[0 + bindex].hi_inode);
>+	return au_ii(inode)->ii_hinode[0 + bindex].hi_id;
>+}
>+
>+// hard/soft set
>+void au_set_ibstart(struct inode *inode, aufs_bindex_t bindex)
>+{
>+	struct au_iinfo *iinfo = au_ii(inode);
>+	struct inode *h_inode;
>+
>+	IiMustWriteLock(inode);
>+	AuDebugOn(au_sbend(inode->i_sb) < bindex);
>+	iinfo->ii_bstart = bindex;
>+	h_inode = iinfo->ii_hinode[bindex + 0].hi_inode;
>+	if (h_inode)
>+		au_cpup_igen(inode, h_inode);
>+}
>+
>+unsigned int au_hi_flags(struct inode *inode, int isdir)
>+{
>+	unsigned int flags;
>+	const unsigned int mnt_flags = au_mntflags(inode->i_sb);
>+
>+	flags = 0;
>+	if (au_opt_test(mnt_flags, XINO))
>+		au_fset_hi(flags, XINO);
>+	if (unlikely(isdir && au_opt_test(mnt_flags, UDBA_INOTIFY)))
>+		au_fset_hi(flags, NOTIFY);
>+	return flags;
>+}
>+
>+void au_set_h_iptr(struct inode *inode, aufs_bindex_t bindex,
>+		   struct inode *h_inode, unsigned int flags)
>+{
>+	struct au_hinode *hinode;
>+	struct inode *hi;
>+	struct au_iinfo *iinfo = au_ii(inode);
>+
>+	LKTRTrace("i%lu, b%d, hi%lu, flags 0x%x\n",
>+		  inode->i_ino, bindex, h_inode ? h_inode->i_ino : 0, flags);
>+	IiMustWriteLock(inode);
>+	hinode = iinfo->ii_hinode + bindex;
>+	hi = hinode->hi_inode;
>+	AuDebugOn(bindex < au_ibstart(inode) || au_ibend(inode) < bindex
>+		  || (h_inode && atomic_read(&h_inode->i_count) <= 0)
>+		  || (h_inode && hi));
>+
>+	if (hi) {
>+		au_hiput(hinode);
>+	}
>+	hinode->hi_inode = h_inode;
>+	if (h_inode) {
>+		int err;
>+		struct super_block *sb = inode->i_sb;
>+
>+		if (bindex == iinfo->ii_bstart)
>+			au_cpup_igen(inode, h_inode);
>+		hinode->hi_id = au_sbr_id(sb, bindex);
>+		if (au_ftest_hi(flags, XINO)) {
>+			struct au_xino_entry xinoe = {
>+				.ino	= inode->i_ino,
>+				//.h_gen	= h_inode->i_generation
>+			};
>+			err = au_xino_write(sb, bindex, h_inode->i_ino, &xinoe);
>+			if (unlikely(err))
>+				AuIOErr1("failed au_xino_write() %d\n", err);
>+		}
>+
>+		if (unlikely(au_ftest_hi(flags, NOTIFY)
>+			     && au_br_hinotifyable(au_sbr_perm(sb, bindex)))) {
>+			err = au_hin_alloc(hinode, inode, h_inode);
>+			if (unlikely(err))
>+				AuIOErr1("au_hin_alloc() %d\n", err);
>+		}
>+	}
>+}
>+
>+void au_set_hi_wh(struct inode *inode, aufs_bindex_t bindex,
>+		  struct dentry *h_wh)
>+{
>+	struct au_hinode *hinode;
>+
>+	IiMustWriteLock(inode);
>+	hinode = au_ii(inode)->ii_hinode + bindex;
>+	AuDebugOn(hinode->hi_whdentry);
>+	hinode->hi_whdentry = h_wh;
>+}
>+
>+void au_update_iigen(struct inode *inode)
>+{
>+	//IiMustWriteLock(inode);
>+	AuDebugOn(!inode->i_sb);
>+	atomic_set(&au_ii(inode)->ii_generation, au_sigen(inode->i_sb));
>+	//smp_mb(); /* atomic_set */
>+}
>+
>+/* it may be called at remount time, too */
>+void au_update_brange(struct inode *inode, int do_put_zero)
>+{
>+	struct au_iinfo *iinfo;
>+
>+	LKTRTrace("i%lu, %d\n", inode->i_ino, do_put_zero);
>+	IiMustWriteLock(inode);
>+
>+	iinfo = au_ii(inode);
>+	if (unlikely(!iinfo) || iinfo->ii_bstart < 0)
>+		return;
>+
>+	if (do_put_zero) {
>+		aufs_bindex_t bindex;
>+		for (bindex = iinfo->ii_bstart; bindex <= iinfo->ii_bend;
>+		     bindex++) {
>+			struct inode *h_i;
>+			h_i = iinfo->ii_hinode[0 + bindex].hi_inode;
>+			if (h_i && !h_i->i_nlink)
>+				au_set_h_iptr(inode, bindex, NULL, 0);
>+		}
>+	}
>+
>+	iinfo->ii_bstart = -1;
>+	while (++iinfo->ii_bstart <= iinfo->ii_bend)
>+		if (iinfo->ii_hinode[0 + iinfo->ii_bstart].hi_inode)
>+			break;
>+	if (iinfo->ii_bstart > iinfo->ii_bend) {
>+		iinfo->ii_bstart = -1;
>+		iinfo->ii_bend = -1;
>+		return;
>+	}
>+
>+	iinfo->ii_bend++;
>+	while (0 <= --iinfo->ii_bend)
>+		if (iinfo->ii_hinode[0 + iinfo->ii_bend].hi_inode)
>+			break;
>+	AuDebugOn(iinfo->ii_bstart > iinfo->ii_bend || iinfo->ii_bend < 0);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int au_iinfo_init(struct inode *inode)
>+{
>+	struct au_iinfo *iinfo;
>+	struct super_block *sb;
>+	int nbr, i;
>+
>+	sb = inode->i_sb;
>+	AuDebugOn(!sb);
>+	iinfo = &(container_of(inode, struct aufs_icntnr, vfs_inode)->iinfo);
>+	AuDebugOn(iinfo->ii_hinode);
>+	nbr = au_sbend(sb) + 1;
>+	if (unlikely(nbr <= 0))
>+		nbr = 1;
>+	iinfo->ii_hinode = kcalloc(nbr, sizeof(*iinfo->ii_hinode), GFP_KERNEL);
>+	//iinfo->ii_hinode = NULL;
>+	if (iinfo->ii_hinode) {
>+		for (i = 0; i < nbr; i++)
>+			iinfo->ii_hinode[i].hi_id = -1;
>+		atomic_set(&iinfo->ii_generation, au_sigen(sb));
>+		//smp_mb(); /* atomic_set */
>+		au_rw_init_nolock(&iinfo->ii_rwsem);
>+		iinfo->ii_bstart = -1;
>+		iinfo->ii_bend = -1;
>+		iinfo->ii_vdir = NULL;
>+		return 0;
>+	}
>+	return -ENOMEM;
>+}
>+
>+static int au_iinfo_write0(struct super_block *sb, struct au_hinode *hinode,
>+			   ino_t ino)
>+{
>+	int err, locked;
>+	aufs_bindex_t bindex;
>+
>+	err = 0;
>+	locked = si_read_trylock(sb, !AuLock_FLUSH); // crucio!
>+	bindex = au_br_index(sb, hinode->hi_id);
>+	if (bindex >= 0)
>+		err = au_xino_write0(sb, bindex, hinode->hi_inode->i_ino, ino);
>+	/* error action? */
>+	if (locked)
>+		si_read_unlock(sb);
>+	return err;
>+}
>+
>+void au_iinfo_fin(struct inode *inode)
>+{
>+	struct au_iinfo *iinfo;
>+	aufs_bindex_t bend;
>+	struct au_hinode *hi;
>+	struct super_block *sb;
>+	int unlinked;
>+	ino_t ino;
>+
>+	iinfo = au_ii(inode);
>+	/* bad_inode case */
>+	if (unlikely(!iinfo))
>+		return;
>+
>+	if (unlikely(iinfo->ii_vdir))
>+		au_vdir_free(iinfo->ii_vdir);
>+
>+	if (iinfo->ii_bstart >= 0) {
>+		sb = inode->i_sb;
>+		unlinked = !inode->i_nlink;
>+		ino = 0;
>+		if (unlinked)
>+			ino = inode->i_ino;
>+		hi = iinfo->ii_hinode + iinfo->ii_bstart;
>+		bend = iinfo->ii_bend;
>+		while (iinfo->ii_bstart++ <= bend) {
>+			if (hi->hi_inode) {
>+				if (unlinked || !hi->hi_inode->i_nlink) {
>+					au_iinfo_write0(sb, hi, ino);
>+					/* ignore this error */
>+					ino = 0;
>+				}
>+				au_hiput(hi);
>+			}
>+			hi++;
>+		}
>+		//iinfo->ii_bstart = iinfo->ii_bend = -1;
>+	}
>+
>+	kfree(iinfo->ii_hinode);
>+	//iinfo->ii_hinode = NULL;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/inode.c linux-2.6.25.4-unionfs/fs/aufs/inode.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/inode.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/inode.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,405 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * inode functions
>+ *
>+ * $Id: inode.c,v 1.3 2008/04/28 03:04:12 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+int au_refresh_hinode_self(struct inode *inode)
>+{
>+	int err, new_sz, update;
>+	struct inode *first;
>+	struct au_hinode *p, *q, tmp;
>+	struct super_block *sb;
>+	struct au_iinfo *iinfo;
>+	aufs_bindex_t bindex, bend, new_bindex;
>+
>+	LKTRTrace("i%lu\n", inode->i_ino);
>+	IiMustWriteLock(inode);
>+
>+	err = -ENOMEM;
>+	update = 0;
>+	sb = inode->i_sb;
>+	bend = au_sbend(sb);
>+	new_sz = sizeof(*iinfo->ii_hinode) * (bend + 1);
>+	iinfo = au_ii(inode);
>+	p = au_kzrealloc(iinfo->ii_hinode, sizeof(*p) * (iinfo->ii_bend + 1),
>+			 new_sz, GFP_KERNEL);
>+	//p = NULL;
>+	if (unlikely(!p))
>+		goto out;
>+
>+	iinfo->ii_hinode = p;
>+	p = iinfo->ii_hinode + iinfo->ii_bstart;
>+	first = p->hi_inode;
>+	err = 0;
>+	for (bindex = iinfo->ii_bstart; bindex <= iinfo->ii_bend;
>+	     bindex++, p++) {
>+		if (!p->hi_inode)
>+			continue;
>+
>+		new_bindex = au_br_index(sb, p->hi_id);
>+		if (new_bindex == bindex)
>+			continue;
>+		if (new_bindex < 0) {
>+			update++;
>+			au_hiput(p);
>+			p->hi_inode = NULL;
>+			continue;
>+		}
>+
>+		if (new_bindex < iinfo->ii_bstart)
>+			iinfo->ii_bstart = new_bindex;
>+		if (iinfo->ii_bend < new_bindex)
>+			iinfo->ii_bend = new_bindex;
>+		/* swap two hidden inode, and loop again */
>+		q = iinfo->ii_hinode + new_bindex;
>+		tmp = *q;
>+		*q = *p;
>+		*p = tmp;
>+		if (tmp.hi_inode) {
>+			bindex--;
>+			p--;
>+		}
>+	}
>+	au_update_brange(inode, /*do_put_zero*/0);
>+
>+	if (unlikely(err))
>+		goto out;
>+
>+	if (1 || first != au_h_iptr(inode, iinfo->ii_bstart))
>+		au_cpup_attr_all(inode);
>+	if (update && S_ISDIR(inode->i_mode))
>+		inode->i_version++;
>+	au_update_iigen(inode);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_refresh_hinode(struct inode *inode, struct dentry *dentry)
>+{
>+	int err, update, isdir;
>+	struct inode *first;
>+	struct au_hinode *p;
>+	struct super_block *sb;
>+	struct au_iinfo *iinfo;
>+	aufs_bindex_t bindex, bend;
>+	unsigned int flags;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	IiMustWriteLock(inode);
>+
>+	err = au_refresh_hinode_self(inode);
>+	if (unlikely(err))
>+		goto out;
>+
>+	sb = dentry->d_sb;
>+	bend = au_sbend(sb);
>+	iinfo = au_ii(inode);
>+	update = 0;
>+	p = iinfo->ii_hinode + iinfo->ii_bstart;
>+	first = p->hi_inode;
>+	isdir = S_ISDIR(inode->i_mode);
>+	flags = au_hi_flags(inode, isdir);
>+	bend = au_dbend(dentry);
>+	for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) {
>+		struct inode *hi;
>+		struct dentry *hd;
>+
>+		hd = au_h_dptr(dentry, bindex);
>+		if (!hd || !hd->d_inode)
>+			continue;
>+
>+		if (iinfo->ii_bstart <= bindex && bindex <= iinfo->ii_bend) {
>+			hi = au_h_iptr(inode, bindex);
>+			if (hi) {
>+				if (hi == hd->d_inode)
>+					continue;
>+				err = -ESTALE;
>+				break;
>+			}
>+		}
>+		if (bindex < iinfo->ii_bstart)
>+			iinfo->ii_bstart = bindex;
>+		if (iinfo->ii_bend < bindex)
>+			iinfo->ii_bend = bindex;
>+		au_set_h_iptr(inode, bindex, igrab(hd->d_inode), flags);
>+		update++;
>+	}
>+	au_update_brange(inode, /*do_put_zero*/0);
>+
>+	if (unlikely(err))
>+		goto out;
>+
>+	if (1 || first != au_h_iptr(inode, iinfo->ii_bstart))
>+		au_cpup_attr_all(inode);
>+	if (update && isdir)
>+		inode->i_version++;
>+	au_update_iigen(inode);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int set_inode(struct inode *inode, struct dentry *dentry)
>+{
>+	int err, isdir;
>+	struct dentry *h_dentry;
>+	struct inode *h_inode;
>+	umode_t mode;
>+	aufs_bindex_t bindex, bstart, btail;
>+	struct au_iinfo *iinfo;
>+	unsigned int flags;
>+
>+	LKTRTrace("i%lu, %.*s\n", inode->i_ino, AuDLNPair(dentry));
>+	AuDebugOn(!(inode->i_state & I_NEW));
>+	IiMustWriteLock(inode);
>+	bstart = au_dbstart(dentry);
>+	h_dentry = au_h_dptr(dentry, bstart);
>+	AuDebugOn(!h_dentry);
>+	h_inode = h_dentry->d_inode;
>+	AuDebugOn(!h_inode);
>+
>+	err = 0;
>+	isdir = 0;
>+	mode = h_inode->i_mode;
>+	switch (mode & S_IFMT) {
>+	case S_IFREG:
>+		btail = au_dbtail(dentry);
>+		break;
>+	case S_IFDIR:
>+		isdir = 1;
>+		btail = au_dbtaildir(dentry);
>+		inode->i_op = &aufs_dir_iop;
>+		inode->i_fop = &aufs_dir_fop;
>+		break;
>+	case S_IFLNK:
>+		btail = au_dbtail(dentry);
>+		inode->i_op = &aufs_symlink_iop;
>+		break;
>+	case S_IFBLK:
>+	case S_IFCHR:
>+	case S_IFIFO:
>+	case S_IFSOCK:
>+		btail = au_dbtail(dentry);
>+		init_special_inode(inode, mode,
>+				   au_h_rdev(h_inode, /*h_mnt*/NULL, h_dentry));
>+		break;
>+	default:
>+		AuIOErr("Unknown file type 0%o\n", mode);
>+		err = -EIO;
>+		goto out;
>+	}
>+
>+	flags = au_hi_flags(inode, isdir);
>+	iinfo = au_ii(inode);
>+	iinfo->ii_bstart = bstart;
>+	iinfo->ii_bend = btail;
>+	for (bindex = bstart; bindex <= btail; bindex++) {
>+		h_dentry = au_h_dptr(dentry, bindex);
>+		if (!h_dentry)
>+			continue;
>+		AuDebugOn(!h_dentry->d_inode);
>+		au_set_h_iptr(inode, bindex, igrab(h_dentry->d_inode), flags);
>+	}
>+	au_cpup_attr_all(inode);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* successful returns with iinfo write_locked */
>+//todo: return with unlocked?
>+static int reval_inode(struct inode *inode, struct dentry *dentry, int *matched)
>+{
>+	int err;
>+	struct inode *h_inode, *h_dinode;
>+	aufs_bindex_t bindex, bend;
>+
>+	LKTRTrace("i%lu, %.*s\n", inode->i_ino, AuDLNPair(dentry));
>+
>+	*matched = 0;
>+
>+	/*
>+	 * before this function, if aufs got any iinfo lock, it must be only
>+	 * one, the parent dir.
>+	 * it can happen by UDBA and the obsoleted inode number.
>+	 */
>+	err = -EIO;
>+	if (unlikely(inode->i_ino == parent_ino(dentry)))
>+		goto out;
>+
>+	err = 0;
>+	h_dinode = au_h_dptr(dentry, au_dbstart(dentry))->d_inode;
>+	mutex_lock_nested(&inode->i_mutex, AuLsc_I_CHILD);
>+	ii_write_lock_new(inode);
>+	bend = au_ibend(inode);
>+	for (bindex = au_ibstart(inode); bindex <= bend; bindex++) {
>+		h_inode = au_h_iptr(inode, bindex);
>+		if (h_inode && h_inode == h_dinode) {
>+			//&& (ibs != bstart || !au_test_higen(inode, h_inode)));
>+			*matched = 1;
>+			err = 0;
>+			if (unlikely(au_iigen(inode) != au_digen(dentry)))
>+				err = au_refresh_hinode(inode, dentry);
>+			break;
>+		}
>+	}
>+	if (unlikely(err))
>+		ii_write_unlock(inode);
>+	mutex_unlock(&inode->i_mutex);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* successful returns with iinfo write_locked */
>+//todo: return with unlocked?
>+struct inode *au_new_inode(struct dentry *dentry)
>+{
>+	struct inode *inode, *h_inode;
>+	struct dentry *h_dentry;
>+	ino_t h_ino;
>+	struct super_block *sb;
>+	int err, match;
>+	aufs_bindex_t bstart;
>+	struct au_xino_entry xinoe;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	sb = dentry->d_sb;
>+	bstart = au_dbstart(dentry);
>+	h_dentry = au_h_dptr(dentry, bstart);
>+	AuDebugOn(!h_dentry);
>+	h_inode = h_dentry->d_inode;
>+	AuDebugOn(!h_inode);
>+
>+	h_ino = h_inode->i_ino;
>+	err = au_xino_read(sb, bstart, h_ino, &xinoe);
>+	//err = -1;
>+	inode = ERR_PTR(err);
>+	if (unlikely(err))
>+		goto out;
>+ new_ino:
>+	if (!xinoe.ino) {
>+		xinoe.ino = au_xino_new_ino(sb);
>+		if (!xinoe.ino) {
>+			inode = ERR_PTR(-EIO);
>+			goto out;
>+		}
>+	}
>+
>+	LKTRTrace("i%lu\n", xinoe.ino);
>+	inode = au_iget_locked(sb, xinoe.ino);
>+	err = PTR_ERR(inode);
>+	if (IS_ERR(inode))
>+		goto out;
>+
>+	LKTRTrace("%lx, new %d\n", inode->i_state, !!(inode->i_state & I_NEW));
>+	if (inode->i_state & I_NEW) {
>+		ii_write_lock_new(inode);
>+		err = set_inode(inode, dentry);
>+		//err = -1;
>+		unlock_new_inode(inode);
>+		if (!err)
>+			goto out; /* success */
>+		iget_failed(inode);
>+		ii_write_unlock(inode);
>+		goto out_iput;
>+	} else {
>+		//todo: remove this
>+		AuDebugOn(inode->i_state & I_LOCK);
>+		err = reval_inode(inode, dentry, &match);
>+		if (!err)
>+			goto out; /* success */
>+		else if (match)
>+			goto out_iput;
>+	}
>+
>+	if (unlikely(au_test_unique_ino(h_dentry, h_ino)))
>+		AuWarn1("Un-notified UDBA or repeatedly renamed dir,"
>+			" b%d, %s, %.*s, hi%lu, i%lu.\n",
>+			bstart, au_sbtype(h_dentry->d_sb), AuDLNPair(dentry),
>+			h_ino, xinoe.ino);
>+	xinoe.ino = 0;
>+	err = au_xino_write0(sb, bstart, h_ino, 0);
>+	if (!err) {
>+		iput(inode);
>+		goto new_ino;
>+	}
>+	/* force noxino? */
>+
>+ out_iput:
>+	iput(inode);
>+	inode = ERR_PTR(err);
>+ out:
>+	AuTraceErrPtr(inode);
>+	return inode;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int au_test_ro(struct super_block *sb, aufs_bindex_t bindex,
>+	       struct inode *inode)
>+{
>+	int err;
>+
>+	err = au_br_rdonly(au_sbr(sb, bindex));
>+
>+	/* pseudo-link after flushed may out of bounds */
>+	if (!err
>+	    && inode
>+	    && au_ibstart(inode) <= bindex
>+	    && bindex <= au_ibend(inode)) {
>+		/*
>+		 * permission check is unnecessary since vfsub routine
>+		 * will be called later
>+		 */
>+		struct inode *hi = au_h_iptr(inode, bindex);
>+		if (hi)
>+			err = IS_IMMUTABLE(hi) ? -EROFS : 0;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_test_h_perm(struct inode *h_inode, int mask, int dlgt)
>+{
>+	if (!current->fsuid)
>+		return 0;
>+	//todo: fake nameidata
>+	return vfsub_permission(h_inode, mask, NULL, dlgt);
>+}
>+
>+int au_test_h_perm_sio(struct inode *h_inode, int mask, int dlgt)
>+{
>+	if (unlikely(au_test_nfs(h_inode->i_sb)
>+		     && (mask & MAY_WRITE)
>+		     && S_ISDIR(h_inode->i_mode)))
>+		mask |= MAY_READ; /* force permission check */
>+	return au_test_h_perm(h_inode, mask, dlgt);
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/inode.h linux-2.6.25.4-unionfs/fs/aufs/inode.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/inode.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/inode.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,326 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * inode operations
>+ *
>+ * $Id: inode.h,v 1.2 2008/04/21 01:32:05 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_INODE_H__
>+#define __AUFS_INODE_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/namei.h>
>+#include <linux/security.h>
>+#include <linux/aufs_type.h>
>+#include "hinode.h"
>+#include "misc.h"
>+#include "super.h"
>+
>+struct au_hinode;
>+struct au_vdir;
>+struct au_iinfo {
>+	atomic_t		ii_generation;
>+	struct super_block	*ii_hsb1;	/* no get/put */
>+
>+	struct au_rwsem		ii_rwsem;
>+	aufs_bindex_t		ii_bstart, ii_bend;
>+	struct au_hinode	*ii_hinode;
>+	struct au_vdir		*ii_vdir;
>+};
>+
>+struct aufs_icntnr {
>+	struct au_iinfo iinfo;
>+	struct inode vfs_inode;
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* inode.c */
>+int au_refresh_hinode_self(struct inode *inode);
>+int au_refresh_hinode(struct inode *inode, struct dentry *dentry);
>+struct inode *au_new_inode(struct dentry *dentry);
>+int au_test_ro(struct super_block *sb, aufs_bindex_t bindex,
>+	       struct inode *inode);
>+int au_test_h_perm(struct inode *h_inode, int mask, int dlgt);
>+int au_test_h_perm_sio(struct inode *h_inode, int mask, int dlgt);
>+
>+/* i_op.c */
>+extern struct inode_operations aufs_iop, aufs_symlink_iop, aufs_dir_iop;
>+
>+/* au_wr_dir flags */
>+#define AuWrDir_ADD_ENTRY	1
>+#define AuWrDir_LOCK_SRCDIR	(1 << 1)
>+#define AuWrDir_ISDIR		(1 << 2)
>+#define au_ftest_wrdir(flags, name)	((flags) & AuWrDir_##name)
>+#define au_fset_wrdir(flags, name)	{ (flags) |= AuWrDir_##name; }
>+#define au_fclr_wrdir(flags, name)	{ (flags) &= ~AuWrDir_##name; }
>+
>+struct au_wr_dir_args {
>+	aufs_bindex_t force_btgt;
>+	unsigned int flags;
>+};
>+int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry,
>+	      struct au_wr_dir_args *args);
>+
>+/* i_op_add.c */
>+struct au_ndx;
>+int au_may_add(struct dentry *dentry, aufs_bindex_t bindex,
>+	       struct dentry *h_parent, int isdir, struct au_ndx *ndx);
>+int aufs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev);
>+int aufs_symlink(struct inode *dir, struct dentry *dentry, const char *symname);
>+int aufs_create(struct inode *dir, struct dentry *dentry, int mode,
>+		struct nameidata *nd);
>+int aufs_link(struct dentry *src_dentry, struct inode *dir,
>+	      struct dentry *dentry);
>+int aufs_mkdir(struct inode *dir, struct dentry *dentry, int mode);
>+
>+/* i_op_del.c */
>+int au_wr_dir_need_wh(struct dentry *dentry, int isdir, aufs_bindex_t *bcpup,
>+		      struct dentry *locked);
>+int au_may_del(struct dentry *dentry, aufs_bindex_t bindex,
>+	       struct dentry *h_parent, int isdir, struct au_ndx *ndx);
>+int aufs_unlink(struct inode *dir, struct dentry *dentry);
>+int aufs_rmdir(struct inode *dir, struct dentry *dentry);
>+
>+/* i_op_ren.c */
>+int au_wbr(struct dentry *dentry, aufs_bindex_t btgt);
>+int aufs_rename(struct inode *src_dir, struct dentry *src_dentry,
>+		struct inode *dir, struct dentry *dentry);
>+
>+#ifdef CONFIG_AUFS_DLGT
>+/* dlgt.c */
>+int au_security_inode_permission(struct inode *h_inode, int mask,
>+				 struct nameidata *fake_nd, int dlgt);
>+#else
>+static inline
>+int au_security_inode_permission(struct inode *h_inode, int mask,
>+				 struct nameidata *fake_nd, int dlgt)
>+{
>+	return security_inode_permission(h_inode, mask, fake_nd);
>+}
>+#endif /* CONFIG_AUFS_DLGT */
>+
>+#ifdef CONFIG_AUFS_WORKAROUND_FUSE
>+/* br_fuse.c */
>+int aufs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *st);
>+#endif
>+
>+/* iinfo.c */
>+struct au_iinfo *au_ii(struct inode *inode);
>+struct inode *au_h_iptr(struct inode *inode, aufs_bindex_t bindex);
>+aufs_bindex_t au_ii_br_id(struct inode *inode, aufs_bindex_t bindex);
>+
>+void au_set_ibstart(struct inode *inode, aufs_bindex_t bindex);
>+void au_set_hi_wh(struct inode *inode, aufs_bindex_t bindex,
>+		  struct dentry *h_wh);
>+unsigned int au_hi_flags(struct inode *inode, int isdir);
>+
>+/* hinode flags */
>+#define AuHi_XINO	1
>+#define AuHi_NOTIFY	(1 << 1)
>+#define au_ftest_hi(flags, name)	((flags) & AuHi_##name)
>+#define au_fset_hi(flags, name)		{ (flags) |= AuHi_##name; }
>+#define au_fclr_hi(flags, name)		{ (flags) &= ~AuHi_##name; }
>+#ifndef CONFIG_AUFS_HINOTIFY
>+#undef AuHi_NOTIFY
>+#define AuHi_NOTIFY	0
>+#endif
>+
>+void au_set_h_iptr(struct inode *inode, aufs_bindex_t bindex,
>+		   struct inode *h_inode, unsigned int flags);
>+
>+void au_update_iigen(struct inode *inode);
>+void au_update_brange(struct inode *inode, int do_put_zero);
>+
>+int au_iinfo_init(struct inode *inode);
>+void au_iinfo_fin(struct inode *inode);
>+
>+/* plink.c */
>+#ifdef CONFIG_AUFS_DEBUG
>+void au_plink_list(struct super_block *sb);
>+#else
>+static inline void au_plink_list(struct super_block *sb)
>+{
>+	/* nothing */
>+}
>+#endif
>+int au_plink_test(struct super_block *sb, struct inode *inode);
>+struct dentry *au_plink_lkup(struct super_block *sb, aufs_bindex_t bindex,
>+			     struct inode *inode);
>+void au_plink_append(struct super_block *sb, struct inode *inode,
>+		     struct dentry *h_dentry, aufs_bindex_t bindex);
>+void au_plink_put(struct super_block *sb);
>+void au_plink_half_refresh(struct super_block *sb, aufs_bindex_t br_id);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* lock subclass for iinfo */
>+enum {
>+	AuLsc_II_CHILD,		/* child first */
>+	AuLsc_II_CHILD2,	/* rename(2), link(2), and cpup at hinotify */
>+	AuLsc_II_CHILD3,	/* copyup dirs */
>+	AuLsc_II_PARENT,
>+	AuLsc_II_PARENT2,
>+	AuLsc_II_PARENT3,
>+	AuLsc_II_PARENT4,
>+	AuLsc_II_NEW		/* new inode */
>+};
>+
>+/*
>+ * ii_read_lock_child, ii_write_lock_child,
>+ * ii_read_lock_child2, ii_write_lock_child2,
>+ * ii_read_lock_child3, ii_write_lock_child3,
>+ * ii_read_lock_parent, ii_write_lock_parent,
>+ * ii_read_lock_parent2, ii_write_lock_parent2,
>+ * ii_read_lock_parent3, ii_write_lock_parent3,
>+ * ii_read_lock_parent4, ii_write_lock_parent4,
>+ * ii_read_lock_new, ii_write_lock_new
>+ */
>+#define AuReadLockFunc(name, lsc) \
>+static inline void ii_read_lock_##name(struct inode *i) \
>+{ au_rw_read_lock_nested(&au_ii(i)->ii_rwsem, AuLsc_II_##lsc); }
>+
>+#define AuWriteLockFunc(name, lsc) \
>+static inline void ii_write_lock_##name(struct inode *i) \
>+{ au_rw_write_lock_nested(&au_ii(i)->ii_rwsem, AuLsc_II_##lsc); }
>+
>+#define AuRWLockFuncs(name, lsc) \
>+	AuReadLockFunc(name, lsc) \
>+	AuWriteLockFunc(name, lsc)
>+
>+AuRWLockFuncs(child, CHILD);
>+AuRWLockFuncs(child2, CHILD2);
>+AuRWLockFuncs(child3, CHILD3);
>+AuRWLockFuncs(parent, PARENT);
>+AuRWLockFuncs(parent2, PARENT2);
>+AuRWLockFuncs(parent3, PARENT3);
>+AuRWLockFuncs(parent4, PARENT4);
>+AuRWLockFuncs(new, NEW);
>+
>+#undef AuReadLockFunc
>+#undef AuWriteLockFunc
>+#undef AuRWLockFuncs
>+
>+/*
>+ * ii_read_unlock, ii_write_unlock, ii_downgrade_lock
>+ */
>+AuSimpleUnlockRwsemFuncs(ii, struct inode *i, au_ii(i)->ii_rwsem);
>+
>+/* to debug easier, do not make them inlined functions */
>+#define IiMustReadLock(i) do { \
>+	SiMustAnyLock((i)->i_sb); \
>+	AuRwMustReadLock(&au_ii(i)->ii_rwsem); \
>+} while (0)
>+
>+#define IiMustWriteLock(i) do { \
>+	SiMustAnyLock((i)->i_sb); \
>+	AuRwMustWriteLock(&au_ii(i)->ii_rwsem); \
>+} while (0)
>+
>+#define IiMustAnyLock(i) do { \
>+	SiMustAnyLock((i)->i_sb); \
>+	AuRwMustAnyLock(&au_ii(i)->ii_rwsem); \
>+} while (0)
>+
>+#define IiMustNoWaiters(i)	AuRwMustNoWaiters(&au_ii(i)->ii_rwsem)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline aufs_bindex_t au_ibstart(struct inode *inode)
>+{
>+	IiMustAnyLock(inode);
>+	return au_ii(inode)->ii_bstart;
>+}
>+
>+static inline aufs_bindex_t au_ibend(struct inode *inode)
>+{
>+	IiMustAnyLock(inode);
>+	return au_ii(inode)->ii_bend;
>+}
>+
>+static inline struct au_vdir *au_ivdir(struct inode *inode)
>+{
>+	IiMustAnyLock(inode);
>+	AuDebugOn(!S_ISDIR(inode->i_mode));
>+	return au_ii(inode)->ii_vdir;
>+}
>+
>+static inline struct dentry *au_hi_wh(struct inode *inode, aufs_bindex_t bindex)
>+{
>+	struct au_hinode *hinode;
>+	IiMustAnyLock(inode);
>+	hinode = au_ii(inode)->ii_hinode + bindex;
>+	return hinode->hi_whdentry;
>+}
>+
>+static inline void au_set_ibend(struct inode *inode, aufs_bindex_t bindex)
>+{
>+	IiMustWriteLock(inode);
>+	AuDebugOn(au_sbend(inode->i_sb) < bindex || bindex < au_ibstart(inode));
>+	au_ii(inode)->ii_bend = bindex;
>+}
>+
>+static inline void au_set_ivdir(struct inode *inode, struct au_vdir *vdir)
>+{
>+	IiMustWriteLock(inode);
>+	AuDebugOn(!S_ISDIR(inode->i_mode) || (au_ii(inode)->ii_vdir && vdir));
>+	au_ii(inode)->ii_vdir = vdir;
>+}
>+
>+static inline void au_hiput(struct au_hinode *hinode)
>+{
>+	au_hin_free(hinode);
>+	dput(hinode->hi_whdentry);
>+	iput(hinode->hi_inode);
>+}
>+
>+static inline struct au_hinode *au_hi(struct inode *inode, aufs_bindex_t bindex)
>+{
>+	//todo: this lock check causes some unnecessary locks in callers.
>+	IiMustAnyLock(inode);
>+	return au_ii(inode)->ii_hinode + bindex;
>+}
>+
>+/* tiny test for inode number */
>+/* tmpfs generation is too rough */
>+static inline int au_test_higen(struct inode *inode, struct inode *h_inode)
>+{
>+	IiMustAnyLock(inode);
>+	return !(au_ii(inode)->ii_hsb1 == h_inode->i_sb
>+		 && inode->i_generation == h_inode->i_generation);
>+}
>+
>+static inline au_gen_t au_iigen(struct inode *inode)
>+{
>+	return atomic_read(&au_ii(inode)->ii_generation);
>+}
>+
>+#ifdef CONFIG_AUFS_HINOTIFY
>+static inline au_gen_t au_iigen_dec(struct inode *inode)
>+{
>+	//AuDbg("i%lu\n", inode->i_ino);
>+	return atomic_dec_return(&au_ii(inode)->ii_generation);
>+}
>+#endif
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_INODE_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/i_op_add.c linux-2.6.25.4-unionfs/fs/aufs/i_op_add.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/i_op_add.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/i_op_add.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,777 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * inode operations (add entry)
>+ *
>+ * $Id: i_op_add.c,v 1.4 2008/05/04 23:54:53 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+/*
>+ * final procedure of adding a new entry, except link(2).
>+ * remove whiteout, instantiate, copyup the parent dir's times and size
>+ * and update version.
>+ * if it failed, re-create the removed whiteout.
>+ */
>+static int epilog(struct inode *dir, struct dentry *wh_dentry,
>+		  struct dentry *dentry)
>+{
>+	int err, rerr;
>+	aufs_bindex_t bwh;
>+	struct inode *inode, *h_dir;
>+	struct dentry *wh;
>+	struct au_ndx ndx;
>+	struct super_block *sb;
>+
>+	LKTRTrace("wh %p, %.*s\n", wh_dentry, AuDLNPair(dentry));
>+
>+	bwh = -1;
>+	if (wh_dentry) {
>+		h_dir = wh_dentry->d_parent->d_inode; /* dir inode is locked */
>+		IMustLock(h_dir);
>+		bwh = au_dbwh(dentry);
>+		err = au_wh_unlink_dentry(h_dir, wh_dentry, dentry, dir,
>+					  /*dlgt*/0);
>+		//err = -1;
>+		if (unlikely(err))
>+			goto out;
>+	}
>+
>+	inode = au_new_inode(dentry);
>+	//inode = ERR_PTR(-1);
>+	if (!IS_ERR(inode)) {
>+		d_instantiate(dentry, inode);
>+		dir = dentry->d_parent->d_inode; /* dir inode is locked */
>+		IMustLock(dir);
>+		/* or always cpup dir mtime? */
>+		if (au_ibstart(dir) == au_dbstart(dentry))
>+			au_cpup_attr_timesizes(dir);
>+		dir->i_version++;
>+		return 0; /* success */
>+	}
>+
>+	err = PTR_ERR(inode);
>+	if (!wh_dentry)
>+		goto out;
>+
>+	/* revert */
>+	sb = dentry->d_sb;
>+	ndx.flags = 0;
>+	if (unlikely(au_opt_test_dlgt(au_mntflags(sb))))
>+		au_fset_ndx(ndx.flags, DLGT);
>+	ndx.nfsmnt = au_nfsmnt(sb, bwh);
>+	ndx.nd = NULL;
>+	//ndx.br = NULL;
>+	/* dir inode is locked */
>+	wh = au_wh_create(dir, dentry, bwh, wh_dentry->d_parent, &ndx);
>+	//wh = ERR_PTR(-1);
>+	rerr = PTR_ERR(wh);
>+	if (!IS_ERR(wh)) {
>+		dput(wh);
>+		goto out;
>+	}
>+	AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
>+		AuDLNPair(dentry), err, rerr);
>+	err = -EIO;
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * simple tests for the adding inode operations.
>+ * following the checks in vfs, plus the parent-child relationship.
>+ */
>+int au_may_add(struct dentry *dentry, aufs_bindex_t bindex,
>+	       struct dentry *h_parent, int isdir, struct au_ndx *ndx)
>+{
>+	int err, exist;
>+	struct dentry *h_dentry;
>+	struct inode *h_inode;
>+	umode_t h_mode;
>+
>+	LKTRTrace("%.*s/%.*s, b%d, dir %d\n",
>+		  AuDLNPair(h_parent), AuDLNPair(dentry), bindex, isdir);
>+
>+	exist = !!dentry->d_inode;
>+	h_dentry = au_h_dptr(dentry, bindex);
>+	h_inode = h_dentry->d_inode;
>+	if (!exist) {
>+		err = -EEXIST;
>+		if (unlikely(h_inode))
>+			goto out;
>+	} else {
>+		/* rename(2) case */
>+		err = -EIO;
>+		if (unlikely(!h_inode || !h_inode->i_nlink))
>+			goto out;
>+
>+		h_mode = h_inode->i_mode;
>+		if (!isdir) {
>+			err = -EISDIR;
>+			if (unlikely(S_ISDIR(h_mode)))
>+				goto out;
>+		} else if (unlikely(!S_ISDIR(h_mode))) {
>+			err = -ENOTDIR;
>+			goto out;
>+		}
>+	}
>+
>+	err = -EIO;
>+	/* expected parent dir is locked */
>+	if (unlikely(h_parent != h_dentry->d_parent))
>+		goto out;
>+	err = 0;
>+
>+	if (unlikely(au_opt_test(au_mntflags(dentry->d_sb), UDBA_INOTIFY))) {
>+		struct dentry *h_latest;
>+		struct qstr *qstr = &dentry->d_name;
>+
>+		err = -EACCES;
>+		if (unlikely(au_test_h_perm
>+			     (h_parent->d_inode, MAY_EXEC | MAY_WRITE,
>+			      au_ftest_ndx(ndx->flags, DLGT))))
>+			goto out;
>+
>+		err = -EIO;
>+		h_latest = au_sio_lkup_one(qstr->name, h_parent, qstr->len,
>+					   ndx);
>+		err = PTR_ERR(h_latest);
>+		if (IS_ERR(h_latest))
>+			goto out;
>+		err = -EIO;
>+		dput(h_latest);
>+		if (h_latest == h_dentry)
>+			err = 0;
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * initial procedure of adding a new entry.
>+ * prepare writable branch and the parent dir, lock it,
>+ * lookup whiteout for the new entry.
>+ */
>+static struct dentry *
>+lock_hdir_lkup_wh(struct dentry *dentry, struct au_dtime *dt,
>+		  struct dentry *src_dentry, struct au_wr_dir_args *wr_dir_args)
>+{
>+	struct dentry *wh_dentry, *parent, *h_parent, *gparent;
>+	int err;
>+	aufs_bindex_t bstart, bcpup;
>+	struct inode *dir, *h_dir, *gdir;
>+	struct au_ndx ndx;
>+	struct super_block *sb;
>+	struct au_hinode *hgdir;
>+	unsigned int mnt_flags;
>+
>+	LKTRTrace("%.*s, src %p\n", AuDLNPair(dentry), src_dentry);
>+
>+	parent = dentry->d_parent; /* dir inode is locked */
>+	IMustLock(parent->d_inode);
>+	bstart = au_dbstart(dentry);
>+	err = au_wr_dir(dentry, src_dentry, wr_dir_args);
>+	bcpup = err;
>+	//err = -1;
>+	wh_dentry = ERR_PTR(err);
>+	if (unlikely(err < 0))
>+		goto out;
>+
>+	sb = parent->d_sb;
>+	mnt_flags = au_mntflags(sb);
>+	//todo: meaningless lock if CONFIG_AUFS_DEBUG is disabled.
>+	hgdir = NULL;
>+	if (unlikely(dt && au_opt_test(mnt_flags, UDBA_INOTIFY)
>+		     && !IS_ROOT(parent))) {
>+		gparent = dget_parent(parent);
>+		gdir = gparent->d_inode;
>+		ii_read_lock_parent2(gdir);
>+		hgdir = au_hi(gdir, bcpup);
>+		ii_read_unlock(gdir);
>+		dput(gparent);
>+	}
>+	dir = parent->d_inode;
>+	h_parent = au_h_dptr(parent, bcpup);
>+	h_dir = h_parent->d_inode;
>+
>+	AuDbgSleep_UdbaRace();
>+	au_hdir_lock(h_dir, dir, bcpup);
>+	//todo: revalidate the lower dentry?
>+
>+	ndx.nfsmnt = au_nfsmnt(sb, bcpup);
>+	ndx.flags = 0;
>+	if (unlikely(au_opt_test_dlgt(mnt_flags)))
>+		au_fset_ndx(ndx.flags, DLGT);
>+	ndx.nd = NULL;
>+	//ndx.br = NULL;
>+	//ndx.nd_file = NULL;
>+
>+	if (!au_opt_test(mnt_flags, UDBA_NONE) && au_dbstart(dentry) == bcpup) {
>+		struct nameidata nd;
>+
>+		if (unlikely(ndx.nfsmnt)) {
>+			//todo: dirty
>+			ndx.nd = &nd;
>+			ndx.br = au_sbr(sb, bcpup);
>+			memset(&nd, 0, sizeof(nd));
>+			nd.flags = LOOKUP_CREATE;
>+			nd.intent.open.flags = O_EXCL;
>+		}
>+		err = au_may_add(dentry, bcpup, h_parent,
>+				 au_ftest_wrdir(wr_dir_args->flags, ISDIR),
>+				 &ndx);
>+		wh_dentry = ERR_PTR(err);
>+		if (unlikely(err))
>+			goto out_dir;
>+		ndx.nd = NULL;
>+		ndx.br = NULL;
>+	}
>+
>+	if (dt)
>+		au_dtime_store(dt, parent, h_parent, hgdir);
>+	wh_dentry = NULL;
>+	if (/* bcpup != bstart || */ bcpup != au_dbwh(dentry))
>+		goto out; /* success */
>+
>+	wh_dentry = au_wh_lkup(h_parent, &dentry->d_name, &ndx);
>+	//wh_dentry = ERR_PTR(-1);
>+
>+ out_dir:
>+	if (IS_ERR(wh_dentry))
>+		au_hdir_unlock(h_dir, dir, bcpup);
>+ out:
>+	AuTraceErrPtr(wh_dentry);
>+	return wh_dentry;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+enum { Mknod, Symlink, Creat };
>+struct simple_arg {
>+	int type;
>+	union {
>+		struct {
>+			int mode;
>+			struct nameidata *nd;
>+		} c;
>+		struct {
>+			const char *symname;
>+		} s;
>+		struct {
>+			int mode;
>+			dev_t dev;
>+		} m;
>+	} u;
>+};
>+
>+static int add_simple(struct inode *dir, struct dentry *dentry,
>+		      struct simple_arg *arg)
>+{
>+	int err, dlgt, created;
>+	struct dentry *h_dentry, *h_parent, *wh_dentry, *parent;
>+	struct inode *h_dir;
>+	struct au_dtime dt;
>+	struct vfsub_args vargs;
>+	struct super_block *sb;
>+	aufs_bindex_t bstart;
>+	struct au_wr_dir_args wr_dir_args = {
>+		.force_btgt	= -1,
>+		.flags		= AuWrDir_ADD_ENTRY
>+	};
>+
>+	LKTRTrace("type %d, %.*s\n", arg->type, AuDLNPair(dentry));
>+	IMustLock(dir);
>+
>+	aufs_read_lock(dentry, AuLock_DW);
>+	parent = dentry->d_parent; /* dir inode is locked */
>+	di_write_lock_parent(parent);
>+	wh_dentry = lock_hdir_lkup_wh(dentry, &dt, /*src_dentry*/NULL,
>+				      &wr_dir_args);
>+	//wh_dentry = ERR_PTR(-1);
>+	err = PTR_ERR(wh_dentry);
>+	if (IS_ERR(wh_dentry))
>+		goto out;
>+
>+	bstart = au_dbstart(dentry);
>+	h_dentry = au_h_dptr(dentry, bstart);
>+	h_parent = h_dentry->d_parent; /* dir inode is locked */
>+	h_dir = h_parent->d_inode;
>+	IMustLock(h_dir);
>+	sb = dir->i_sb;
>+	dlgt = !!au_opt_test_dlgt(au_mntflags(sb));
>+
>+	switch (arg->type) {
>+	case Creat:
>+		AuDebugOn(au_test_nfs(h_dir->i_sb) && !arg->u.c.nd);
>+		err = au_h_create(h_dir, h_dentry, arg->u.c.mode, dlgt,
>+				  arg->u.c.nd, au_nfsmnt(sb, bstart));
>+		break;
>+	case Symlink:
>+		err = vfsub_symlink(h_dir, h_dentry, arg->u.s.symname,
>+				    S_IALLUGO, dlgt);
>+		break;
>+	case Mknod:
>+		err = vfsub_mknod(h_dir, h_dentry, arg->u.m.mode, arg->u.m.dev,
>+				  dlgt);
>+		break;
>+	default:
>+		BUG();
>+	}
>+	created = !err;
>+	if (!err)
>+		err = epilog(dir, wh_dentry, dentry);
>+	//err = -1;
>+
>+	/* revert */
>+	if (unlikely(created && err && h_dentry->d_inode)) {
>+		int rerr;
>+		vfsub_args_init(&vargs, NULL, dlgt, 0);
>+		rerr = vfsub_unlink(h_dir, h_dentry, &vargs);
>+		//rerr = -1;
>+		if (rerr) {
>+			AuIOErr("%.*s revert failure(%d, %d)\n",
>+				AuDLNPair(dentry), err, rerr);
>+			err = -EIO;
>+		}
>+		//todo: inotify will be fired to the grand parent dir
>+		au_dtime_revert(&dt);
>+		d_drop(dentry);
>+	}
>+
>+	au_hdir_unlock(h_dir, dir, bstart);
>+	dput(wh_dentry);
>+
>+ out:
>+	if (unlikely(err)) {
>+		au_update_dbstart(dentry);
>+		d_drop(dentry);
>+	}
>+	di_write_unlock(parent);
>+	aufs_read_unlock(dentry, AuLock_DW);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int aufs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
>+{
>+	struct simple_arg arg = {
>+		.type = Mknod,
>+		.u.m = {
>+			.mode	= mode,
>+			.dev	= dev
>+		}
>+	};
>+	return add_simple(dir, dentry, &arg);
>+}
>+
>+int aufs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
>+{
>+	struct simple_arg arg = {
>+		.type = Symlink,
>+		.u.s.symname = symname
>+	};
>+	return add_simple(dir, dentry, &arg);
>+}
>+
>+int aufs_create(struct inode *dir, struct dentry *dentry, int mode,
>+		struct nameidata *nd)
>+{
>+	struct simple_arg arg = {
>+		.type = Creat,
>+		.u.c = {
>+			.mode	= mode,
>+			.nd	= nd
>+		}
>+	};
>+	return add_simple(dir, dentry, &arg);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct link_arg {
>+	aufs_bindex_t bdst, bsrc;
>+	int issamedir, dlgt;
>+	struct dentry *src_parent, *parent, *h_dentry;
>+	struct inode *h_dir, *inode, *dir;
>+};
>+
>+static int cpup_before_link(struct dentry *src_dentry, struct inode *dir,
>+			    struct link_arg *a)
>+{
>+	int err;
>+	struct inode *hi, *h_dir, *src_dir, *gdir;
>+	struct dentry *gparent;
>+
>+	AuTraceEnter();
>+
>+	gparent = NULL;
>+	gdir = NULL;
>+	if (unlikely(au_opt_test(au_mntflags(src_dentry->d_sb), UDBA_INOTIFY)
>+		     && !IS_ROOT(a->src_parent))) {
>+		gparent = dget_parent(a->src_parent);
>+		gdir = gparent->d_inode;
>+		if (gdir == dir) {
>+			dput(gparent);
>+			gparent = NULL;
>+		}
>+	}
>+	src_dir = a->src_parent->d_inode;
>+	h_dir = NULL;
>+
>+	if (!a->issamedir) {
>+		/* this temporary unlock/lock is safe */
>+		au_hdir_unlock(a->h_dir, dir, a->bdst);
>+		di_read_lock_parent2(a->src_parent, AuLock_IR);
>+		err = au_test_and_cpup_dirs(src_dentry, a->bdst, a->parent);
>+		//err = -1;
>+		if (unlikely(err)) {
>+			au_hdir_lock(a->h_dir, dir, a->bdst);
>+			goto out;
>+		}
>+
>+		//todo: meaningless lock if CONFIG_AUFS_DEBUG is disabled.
>+		if (unlikely(gparent))
>+			ii_read_lock_parent3(gdir);
>+		h_dir = au_h_iptr(src_dir, a->bdst);
>+		au_hdir_lock(h_dir, src_dir, a->bdst);
>+	} else if (unlikely(gparent)) {
>+		/* this temporary unlock/lock is safe */
>+		au_hdir_unlock(a->h_dir, dir, a->bdst);
>+		ii_read_lock_parent3(gdir);
>+		au_hdir_lock(a->h_dir, dir, a->bdst);
>+	}
>+	//todo: test parent-gparent relationship
>+
>+	AuDebugOn(au_dbstart(src_dentry) != a->bsrc);
>+	hi = au_h_dptr(src_dentry, a->bsrc)->d_inode;
>+	mutex_lock_nested(&hi->i_mutex, AuLsc_I_CHILD);
>+	err = au_sio_cpup_simple(src_dentry, a->bdst, -1, AuCpup_DTIME);
>+	//err = -1;
>+	mutex_unlock(&hi->i_mutex);
>+
>+	if (unlikely(gparent)) {
>+		ii_read_unlock(gdir);
>+		dput(gparent);
>+	}
>+
>+ out:
>+	if (h_dir) {
>+		au_hdir_unlock(h_dir, src_dir, a->bdst);
>+		au_hdir_lock(a->h_dir, dir, a->bdst);
>+	}
>+	if (!a->issamedir)
>+		di_read_unlock(a->src_parent, AuLock_IR);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int cpup_or_link(struct dentry *src_dentry, struct link_arg *a)
>+{
>+	int err;
>+	struct inode *inode, *h_inode, *h_dst_inode;
>+	struct dentry *h_dentry;
>+	aufs_bindex_t bstart;
>+	struct super_block *sb;
>+
>+	AuTraceEnter();
>+
>+	sb = src_dentry->d_sb;
>+	inode = src_dentry->d_inode;
>+	AuDebugOn(au_dbstart(src_dentry) != a->bsrc);
>+	h_dentry = au_h_dptr(src_dentry, a->bsrc);
>+	h_inode = h_dentry->d_inode;
>+	bstart = au_ibstart(inode);
>+	h_dst_inode = NULL;
>+	if (bstart <= a->bdst)
>+		h_dst_inode = au_h_iptr(inode, a->bdst);
>+
>+	if (!h_dst_inode || !h_dst_inode->i_nlink) {
>+		/* copyup src_dentry as the name of dentry. */
>+		au_set_dbstart(src_dentry, a->bdst);
>+		au_set_h_dptr(src_dentry, a->bdst, dget(a->h_dentry));
>+		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
>+		err = au_sio_cpup_single(src_dentry, a->bdst, a->bsrc, -1,
>+					 !AuCpup_DTIME);
>+		//err = -1;
>+		mutex_unlock(&h_inode->i_mutex);
>+		au_set_h_dptr(src_dentry, a->bdst, NULL);
>+		au_set_dbstart(src_dentry, a->bsrc);
>+	} else {
>+		/* the inode of src_dentry already exists on a.bdst branch */
>+		h_dentry = d_find_alias(h_dst_inode);
>+		if (h_dentry) {
>+			err = vfsub_link(h_dentry, a->h_dir,
>+					 a->h_dentry, a->dlgt);
>+			dput(h_dentry);
>+		} else {
>+			AuIOErr("no dentry found for i%lu on b%d\n",
>+				h_dst_inode->i_ino, a->bdst);
>+			err = -EIO;
>+		}
>+	}
>+
>+	if (!err)
>+		au_plink_append(sb, a->inode, a->h_dentry, a->bdst);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int aufs_link(struct dentry *src_dentry, struct inode *dir,
>+	      struct dentry *dentry)
>+{
>+	int err, rerr;
>+	struct dentry *h_parent, *wh_dentry, *h_src_dentry;
>+	struct au_dtime dt;
>+	struct link_arg a;
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+	struct vfsub_args vargs;
>+	struct au_wr_dir_args wr_dir_args = {
>+		//.force_btgt	= -1,
>+		.flags		= AuWrDir_ADD_ENTRY
>+	};
>+
>+	LKTRTrace("src %.*s, i%lu, dst %.*s\n",
>+		  AuDLNPair(src_dentry), dir->i_ino, AuDLNPair(dentry));
>+	IMustLock(dir);
>+	IMustLock(src_dentry->d_inode);
>+	AuDebugOn(S_ISDIR(src_dentry->d_inode->i_mode));
>+
>+	aufs_read_and_write_lock2(dentry, src_dentry, /*flags*/0);
>+	sb = dentry->d_sb;
>+	a.dir = dir;
>+	a.src_parent = dget_parent(src_dentry);
>+	a.parent = dentry->d_parent; /* dir inode is locked */
>+	a.issamedir = (a.src_parent == a.parent);
>+	if (!a.issamedir)
>+		au_fset_wrdir(wr_dir_args.flags, LOCK_SRCDIR);
>+	wr_dir_args.force_btgt = au_dbstart(src_dentry);
>+	di_write_lock_parent(a.parent);
>+	wr_dir_args.force_btgt = au_wbr(dentry, wr_dir_args.force_btgt);
>+	wh_dentry = lock_hdir_lkup_wh(dentry, &dt, src_dentry, &wr_dir_args);
>+	//wh_dentry = ERR_PTR(-1);
>+	err = PTR_ERR(wh_dentry);
>+	if (IS_ERR(wh_dentry))
>+		goto out;
>+
>+	a.inode = src_dentry->d_inode;
>+	a.bdst = au_dbstart(dentry);
>+	a.h_dentry = au_h_dptr(dentry, a.bdst);
>+	h_parent = a.h_dentry->d_parent; /* dir inode is locked */
>+	a.h_dir = h_parent->d_inode;
>+	IMustLock(a.h_dir);
>+
>+	err = 0;
>+	mnt_flags = au_mntflags(sb);
>+	a.dlgt = !!au_opt_test_dlgt(mnt_flags);
>+
>+	//todo: minor optimize, their sb may be same while their bindex differs.
>+	a.bsrc = au_dbstart(src_dentry);
>+	h_src_dentry = au_h_dptr(src_dentry, a.bsrc);
>+	if (unlikely(!au_opt_test(mnt_flags, PLINK))) {
>+		/*
>+		 * copyup src_dentry to the branch we process,
>+		 * and then link(2) to it.
>+		 * gave up 'pseudo link by cpup' approach,
>+		 * since nlink may be one and some applications will not work.
>+		 */
>+		if (a.bdst < a.bsrc
>+		    /* && h_src_dentry->d_sb != a.h_dentry->d_sb */)
>+			err = cpup_before_link(src_dentry, dir, &a);
>+		if (!err) {
>+			h_src_dentry = au_h_dptr(src_dentry, a.bdst);
>+			err = vfsub_link(h_src_dentry, a.h_dir, a.h_dentry,
>+					 a.dlgt);
>+			//err = -1;
>+		}
>+	} else {
>+		if (a.bdst < a.bsrc
>+		    /* && h_src_dentry->d_sb != a.h_dentry->d_sb */)
>+			err = cpup_or_link(src_dentry, &a);
>+		else {
>+			h_src_dentry = au_h_dptr(src_dentry, a.bdst);
>+			err = vfsub_link(h_src_dentry, a.h_dir, a.h_dentry,
>+					 a.dlgt);
>+			//err = -1;
>+		}
>+	}
>+	if (unlikely(err))
>+		goto out_unlock;
>+	if (wh_dentry) {
>+		err = au_wh_unlink_dentry(a.h_dir, wh_dentry, dentry,
>+					  dir, /*dlgt*/0);
>+		//err = -1;
>+		if (unlikely(err))
>+			goto out_revert;
>+	}
>+
>+	dir->i_version++;
>+	if (au_ibstart(dir) == au_dbstart(dentry))
>+		au_cpup_attr_timesizes(dir);
>+	if (!d_unhashed(a.h_dentry)
>+	    /* || h_old_inode->i_nlink <= nlink */
>+	    /* || SB_NFS(h_src_dentry->d_sb) */) {
>+		dentry->d_inode = igrab(a.inode);
>+		d_instantiate(dentry, a.inode);
>+		inc_nlink(a.inode);
>+		a.inode->i_ctime = dir->i_ctime;
>+	} else
>+		/* nfs case (< 2.6.15) */
>+		d_drop(dentry);
>+	goto out_unlock; /* success */
>+
>+ out_revert:
>+	vfsub_args_init(&vargs, NULL, a.dlgt, 0);
>+	rerr = vfsub_unlink(a.h_dir, a.h_dentry, &vargs);
>+	//rerr = -1;
>+	if (!rerr)
>+		goto out_dt;
>+// out_rerr:
>+	AuIOErr("%.*s reverting failed(%d, %d)\n",
>+		AuDLNPair(dentry), err, rerr);
>+	err = -EIO;
>+ out_dt:
>+	d_drop(dentry);
>+	au_dtime_revert(&dt);
>+ out_unlock:
>+	au_hdir_unlock(a.h_dir, dir, a.bdst);
>+	dput(wh_dentry);
>+ out:
>+	if (unlikely(err)) {
>+		au_update_dbstart(dentry);
>+		d_drop(dentry);
>+	}
>+	di_write_unlock(a.parent);
>+	dput(a.src_parent);
>+	aufs_read_and_write_unlock2(dentry, src_dentry);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int aufs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
>+{
>+	int err, rerr, diropq, dlgt;
>+	struct dentry *h_dentry, *h_parent, *wh_dentry, *parent, *opq_dentry;
>+	struct inode *h_dir, *h_inode;
>+	struct au_dtime dt;
>+	aufs_bindex_t bindex;
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+	struct vfsub_args vargs;
>+	struct au_wr_dir_args wr_dir_args = {
>+		.force_btgt	= -1,
>+		.flags		= AuWrDir_ADD_ENTRY | AuWrDir_ISDIR
>+	};
>+
>+	LKTRTrace("i%lu, %.*s, mode 0%o\n",
>+		  dir->i_ino, AuDLNPair(dentry), mode);
>+	IMustLock(dir);
>+
>+	aufs_read_lock(dentry, AuLock_DW);
>+	parent = dentry->d_parent; /* dir inode is locked */
>+	di_write_lock_parent(parent);
>+	wh_dentry = lock_hdir_lkup_wh(dentry, &dt, /*src_dentry*/NULL,
>+				      &wr_dir_args);
>+	//wh_dentry = ERR_PTR(-1);
>+	err = PTR_ERR(wh_dentry);
>+	if (IS_ERR(wh_dentry))
>+		goto out;
>+
>+	sb = dentry->d_sb;
>+	bindex = au_dbstart(dentry);
>+	h_dentry = au_h_dptr(dentry, bindex);
>+	h_parent = h_dentry->d_parent; /* dir inode is locked */
>+	h_dir = h_parent->d_inode;
>+	IMustLock(h_dir);
>+	mnt_flags = au_mntflags(sb);
>+	dlgt = !!au_opt_test_dlgt(mnt_flags);
>+
>+	err = vfsub_mkdir(h_dir, h_dentry, mode, dlgt);
>+	//err = -1;
>+	if (unlikely(err))
>+		goto out_unlock;
>+	h_inode = h_dentry->d_inode;
>+
>+	/* make the dir opaque */
>+	diropq = 0;
>+	if (wh_dentry || au_opt_test(mnt_flags, ALWAYS_DIROPQ)) {
>+		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
>+		opq_dentry = au_diropq_create(dentry, bindex, /*dlgt*/0);
>+		//opq_dentry = ERR_PTR(-1);
>+		mutex_unlock(&h_inode->i_mutex);
>+		err = PTR_ERR(opq_dentry);
>+		if (IS_ERR(opq_dentry))
>+			goto out_dir;
>+		dput(opq_dentry);
>+		diropq = 1;
>+	}
>+
>+	err = epilog(dir, wh_dentry, dentry);
>+	//err = -1;
>+	if (!err) {
>+		inc_nlink(dir);
>+		goto out_unlock; /* success */
>+	}
>+
>+	/* revert */
>+	if (diropq) {
>+		LKTRLabel(revert opq);
>+		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
>+		rerr = au_diropq_remove(dentry, bindex, dlgt);
>+		//rerr = -1;
>+		mutex_unlock(&h_inode->i_mutex);
>+		if (rerr) {
>+			AuIOErr("%.*s reverting diropq failed(%d, %d)\n",
>+				AuDLNPair(dentry), err, rerr);
>+			err = -EIO;
>+		}
>+	}
>+
>+ out_dir:
>+	LKTRLabel(revert dir);
>+	vfsub_args_init(&vargs, NULL, dlgt, 0);
>+	rerr = vfsub_rmdir(h_dir, h_dentry, &vargs);
>+	//rerr = -1;
>+	if (rerr) {
>+		AuIOErr("%.*s reverting dir failed(%d, %d)\n",
>+			AuDLNPair(dentry), err, rerr);
>+		err = -EIO;
>+	}
>+	d_drop(dentry);
>+	au_dtime_revert(&dt);
>+ out_unlock:
>+	au_hdir_unlock(h_dir, dir, bindex);
>+	dput(wh_dentry);
>+ out:
>+	if (unlikely(err)) {
>+		au_update_dbstart(dentry);
>+		d_drop(dentry);
>+	}
>+	di_write_unlock(parent);
>+	aufs_read_unlock(dentry, AuLock_DW);
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/i_op.c linux-2.6.25.4-unionfs/fs/aufs/i_op.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/i_op.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/i_op.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,732 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * inode operations (except add/del/rename)
>+ *
>+ * $Id: i_op.c,v 1.5 2008/05/19 01:46:53 sfjro Exp $
>+ */
>+
>+//#include <linux/fs.h>
>+#include <linux/fs_stack.h>
>+//#include <linux/namei.h>
>+//#include <linux/mm.h>
>+#include <linux/uaccess.h>
>+#include "aufs.h"
>+
>+static int h_permission(struct inode *h_inode, int mask,
>+			struct nameidata *fake_nd, int brperm, int dlgt)
>+{
>+	int err, submask;
>+	const int write_mask = (mask & (MAY_WRITE | MAY_APPEND));
>+
>+	LKTRTrace("ino %lu, mask 0x%x, brperm 0x%x\n",
>+		  h_inode->i_ino, mask, brperm);
>+
>+	err = -EACCES;
>+	if (unlikely((write_mask && IS_IMMUTABLE(h_inode))
>+		     || ((mask & MAY_EXEC) && S_ISREG(h_inode->i_mode)
>+			 && fake_nd && fake_nd->path.mnt
>+			 && (fake_nd->path.mnt->mnt_flags & MNT_NOEXEC))
>+		    ))
>+		goto out;
>+
>+	/* skip hidden fs test in the case of write to ro branch */
>+	submask = mask & ~MAY_APPEND;
>+	if (unlikely((write_mask && !au_br_writable(brperm))
>+		     || !h_inode->i_op
>+		     || !h_inode->i_op->permission)) {
>+		//LKTRLabel(generic_permission);
>+		err = generic_permission(h_inode, submask, NULL);
>+	} else {
>+		//LKTRLabel(h_inode->permission);
>+		err = h_inode->i_op->permission(h_inode, submask, fake_nd);
>+		AuTraceErr(err);
>+	}
>+
>+	if (!err)
>+		err = au_security_inode_permission(h_inode, mask, fake_nd,
>+						   dlgt);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int silly_lock(struct inode *inode, struct nameidata *nd)
>+{
>+	int locked = 0;
>+	struct super_block *sb = inode->i_sb;
>+
>+	LKTRTrace("i%lu, nd %p\n", inode->i_ino, nd);
>+
>+	if (!nd || !nd->path.dentry) {
>+		si_read_lock(sb, AuLock_FLUSH);
>+		ii_read_lock_child(inode);
>+	} else if (nd->path.dentry->d_inode != inode) {
>+		locked = 1;
>+		/* lock child first, then parent */
>+		si_read_lock(sb, AuLock_FLUSH);
>+		ii_read_lock_child(inode);
>+		di_read_lock_parent(nd->path.dentry, 0);
>+	} else {
>+		locked = 2;
>+		aufs_read_lock(nd->path.dentry, AuLock_FLUSH | AuLock_IR);
>+	}
>+	return locked;
>+}
>+
>+static void silly_unlock(int locked, struct inode *inode, struct nameidata *nd)
>+{
>+	struct super_block *sb = inode->i_sb;
>+
>+	LKTRTrace("locked %d, i%lu, nd %p\n", locked, inode->i_ino, nd);
>+
>+	switch (locked) {
>+	case 0:
>+		ii_read_unlock(inode);
>+		si_read_unlock(sb);
>+		break;
>+	case 1:
>+		di_read_unlock(nd->path.dentry, 0);
>+		ii_read_unlock(inode);
>+		si_read_unlock(sb);
>+		break;
>+	case 2:
>+		aufs_read_unlock(nd->path.dentry, AuLock_FLUSH | AuLock_IR);
>+		break;
>+	default:
>+		BUG();
>+	}
>+}
>+
>+static int aufs_permission(struct inode *inode, int mask, struct nameidata *nd)
>+{
>+	int err, locked, dlgt;
>+	aufs_bindex_t bindex, bend;
>+	struct inode *h_inode;
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+	struct nameidata fake_nd, *p;
>+	const int write_mask = (mask & (MAY_WRITE | MAY_APPEND));
>+	const int nondir = !S_ISDIR(inode->i_mode);
>+
>+	LKTRTrace("ino %lu, mask 0x%x, nondir %d, write_mask %d, "
>+		  "nd %d{%d, %d}\n",
>+		  inode->i_ino, mask, nondir, write_mask,
>+		  !!nd, nd ? !!nd->path.dentry : 0, nd ? !!nd->path.mnt : 0);
>+
>+	sb = inode->i_sb;
>+	locked = silly_lock(inode, nd);
>+	mnt_flags = au_mntflags(sb);
>+	dlgt = !!au_opt_test_dlgt(mnt_flags);
>+
>+	if (nd)
>+		fake_nd = *nd;
>+	if (/* unlikely */(nondir || write_mask
>+			   || au_opt_test_dirperm1(mnt_flags))) {
>+		h_inode = au_h_iptr(inode, au_ibstart(inode));
>+		AuDebugOn(!h_inode
>+			  || ((h_inode->i_mode & S_IFMT)
>+			      != (inode->i_mode & S_IFMT)));
>+		err = 0;
>+		bindex = au_ibstart(inode);
>+		p = au_fake_dm(&fake_nd, nd, sb, bindex);
>+		/* actual test will be delegated to LSM */
>+		if (IS_ERR(p))
>+			AuDebugOn(PTR_ERR(p) != -ENOENT);
>+		else {
>+			LKTRTrace("b%d\n", bindex);
>+			err = h_permission(h_inode, mask, p,
>+					   au_sbr_perm(sb, bindex), dlgt);
>+			au_fake_dm_release(p);
>+		}
>+		if (write_mask && !err) {
>+			/* test whether the upper writable branch exists */
>+			err = -EROFS;
>+			for (; bindex >= 0; bindex--)
>+				if (!au_br_rdonly(au_sbr(sb, bindex))) {
>+					err = 0;
>+					break;
>+				}
>+		}
>+		goto out;
>+	}
>+
>+	/* non-write to dir */
>+	err = 0;
>+	bend = au_ibend(inode);
>+	for (bindex = au_ibstart(inode); !err && bindex <= bend; bindex++) {
>+		h_inode = au_h_iptr(inode, bindex);
>+		if (!h_inode)
>+			continue;
>+		AuDebugOn(!S_ISDIR(h_inode->i_mode));
>+
>+		p = au_fake_dm(&fake_nd, nd, sb, bindex);
>+		/* actual test will be delegated to LSM */
>+		if (IS_ERR(p))
>+			AuDebugOn(PTR_ERR(p) != -ENOENT);
>+		else {
>+			LKTRTrace("b%d\n", bindex);
>+			err = h_permission(h_inode, mask, p,
>+					   au_sbr_perm(sb, bindex), dlgt);
>+			au_fake_dm_release(p);
>+		}
>+	}
>+
>+ out:
>+	silly_unlock(locked, inode, nd);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static struct dentry *aufs_lookup(struct inode *dir, struct dentry *dentry,
>+				  struct nameidata *nd)
>+{
>+	struct dentry *ret, *parent;
>+	int err, npositive;
>+	struct inode *inode, *h_inode;
>+	struct nameidata tmp_nd, *ndp;
>+
>+	LKTRTrace("dir %lu, %.*s, nd{0x%x}\n",
>+		  dir->i_ino, AuDLNPair(dentry), nd ? nd->flags : 0);
>+	AuDebugOn(IS_ROOT(dentry));
>+	IMustLock(dir);
>+
>+	/* nd can be NULL */
>+	parent = dentry->d_parent; /* dir inode is locked */
>+	aufs_read_lock(parent, AuLock_FLUSH);
>+	err = au_alloc_dinfo(dentry);
>+	//if (LktrCond) err = -1;
>+	ret = ERR_PTR(err);
>+	if (unlikely(err))
>+		goto out;
>+
>+	ndp = au_dup_nd(au_sbi(dir->i_sb), &tmp_nd, nd);
>+	npositive = au_lkup_dentry(dentry, au_dbstart(parent), /*type*/0, ndp);
>+	err = npositive;
>+	//err = -1;
>+	ret = ERR_PTR(err);
>+	if (unlikely(err < 0))
>+		goto out_unlock;
>+	inode = NULL;
>+	if (npositive) {
>+		/*
>+		 * stop 'race'-ing between hardlinks under different parents.
>+		 */
>+		h_inode = au_h_dptr(dentry, au_dbstart(dentry))->d_inode;
>+		AuDebugOn(!h_inode);
>+		if (h_inode->i_nlink == 1 || S_ISDIR(h_inode->i_mode))
>+			inode = au_new_inode(dentry);
>+		else {
>+			static DEFINE_MUTEX(mtx);
>+			mutex_lock(&mtx);
>+			inode = au_new_inode(dentry);
>+			mutex_unlock(&mtx);
>+		}
>+		ret = (void *)inode;
>+	}
>+	if (!IS_ERR(inode)) {
>+		/* d_splice_alias() also supports d_add() */
>+		ret = d_splice_alias(inode, dentry);
>+		if (unlikely(IS_ERR(ret) && inode))
>+			ii_write_unlock(inode);
>+		//AuDbgDentry(dentry);
>+		AuDebugOn(nd
>+			  && (nd->flags & LOOKUP_OPEN)
>+			  && nd->intent.open.file
>+			  && nd->intent.open.file->f_dentry);
>+		au_store_fmode_exec(nd, inode);
>+	}
>+
>+ out_unlock:
>+	di_write_unlock(dentry);
>+ out:
>+	aufs_read_unlock(parent, !AuLock_IR);
>+	AuTraceErrPtr(ret);
>+	return ret;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * decide the branch and the parent dir where we will create a new entry.
>+ * returns new bindex or an error.
>+ * copyup the parent dir if needed.
>+ */
>+int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry,
>+	      struct au_wr_dir_args *args)
>+{
>+	int err;
>+	aufs_bindex_t bcpup, bstart, src_bstart;
>+	struct super_block *sb;
>+	struct dentry *parent, *src_parent;
>+	struct au_sbinfo *sbinfo;
>+	const int add_entry = au_ftest_wrdir(args->flags, ADD_ENTRY);
>+	const int lock_srcdir = au_ftest_wrdir(args->flags, LOCK_SRCDIR);
>+
>+	LKTRTrace("%.*s, src %p, {%d, 0x%x}\n",
>+		  AuDLNPair(dentry), src_dentry, args->force_btgt, args->flags);
>+	//AuDbgDentry(dentry);
>+
>+	src_parent = NULL;
>+	sb = dentry->d_sb;
>+	sbinfo = au_sbi(sb);
>+	parent = dget_parent(dentry);
>+	bstart = au_dbstart(dentry);
>+	bcpup = bstart;
>+	if (args->force_btgt < 0) {
>+		if (src_dentry) {
>+			src_bstart = au_dbstart(src_dentry);
>+			if (src_bstart < bstart)
>+				bcpup = src_bstart;
>+		} else if (add_entry) {
>+			err = AuWbrCreate(sbinfo, dentry,
>+					  au_ftest_wrdir(args->flags, ISDIR));
>+			bcpup = err;
>+		}
>+
>+		if (bcpup < 0 || au_test_ro(sb, bcpup, dentry->d_inode)) {
>+			if (add_entry)
>+				err = AuWbrCopyup(sbinfo, dentry);
>+			else {
>+				di_read_lock_parent(parent, !AuLock_IR);
>+				err = AuWbrCopyup(sbinfo, dentry);
>+				di_read_unlock(parent, !AuLock_IR);
>+			}
>+			//err = -1;
>+			bcpup = err;
>+			if (unlikely(err < 0))
>+				goto out;
>+		}
>+	} else {
>+		bcpup = args->force_btgt;
>+		AuDebugOn(au_test_ro(sb, bcpup, dentry->d_inode));
>+	}
>+	LKTRTrace("bstart %d, bcpup %d\n", bstart, bcpup);
>+	if (bstart < bcpup)
>+		au_update_dbrange(dentry, /*do_put_zero*/1);
>+
>+	err = bcpup;
>+	if (bcpup == bstart)
>+		goto out; /* success */
>+
>+	/* copyup the new parent into the branch we process */
>+	if (src_dentry) {
>+		src_parent = dget_parent(src_dentry);
>+		if (lock_srcdir)
>+			di_write_lock_parent2(src_parent);
>+	}
>+
>+	if (add_entry) {
>+		au_update_dbstart(dentry);
>+		IMustLock(parent->d_inode);
>+		DiMustWriteLock(parent);
>+		IiMustWriteLock(parent->d_inode);
>+	} else
>+		di_write_lock_parent(parent);
>+
>+	err = 0;
>+	if (!au_h_dptr(parent, bcpup)) {
>+		if (bstart < bcpup)
>+			err = au_cpdown_dirs(dentry, bcpup, src_parent);
>+		else
>+			err = au_cpup_dirs(dentry, bcpup, src_parent);
>+	}
>+	//err = -1;
>+	if (!err && add_entry) {
>+		struct dentry *h_parent;
>+		struct inode *h_dir;
>+
>+		h_parent = au_h_dptr(parent, bcpup);
>+		AuDebugOn(!h_parent);
>+		h_dir = h_parent->d_inode;
>+		AuDebugOn(!h_dir);
>+		mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
>+		err = au_lkup_neg(dentry, bcpup);
>+		//err = -1;
>+		mutex_unlock(&h_dir->i_mutex);
>+		if (bstart < bcpup && au_dbstart(dentry) < 0) {
>+			au_set_dbstart(dentry, 0);
>+			au_update_dbrange(dentry, /*do_put_zero*/0);
>+		}
>+	}
>+
>+	if (!add_entry)
>+		di_write_unlock(parent);
>+	if (lock_srcdir)
>+		di_write_unlock(src_parent);
>+	dput(src_parent);
>+	if (!err)
>+		err = bcpup; /* success */
>+	//err = -EPERM;
>+ out:
>+	dput(parent);
>+	LKTRTrace("err %d\n", err);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static void au_hi_lock(struct inode *h_inode, int isdir, struct inode *inode,
>+		       aufs_bindex_t bindex)
>+{
>+	if (!isdir)
>+		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
>+	else
>+		au_hdir2_lock(h_inode, inode, bindex);
>+}
>+
>+static void au_hi_unlock(struct inode *h_inode, int isdir, struct inode *inode,
>+			 aufs_bindex_t bindex)
>+{
>+	if (!isdir)
>+		mutex_unlock(&h_inode->i_mutex);
>+	else
>+		au_hdir_unlock(h_inode, inode, bindex);
>+}
>+
>+struct au_icpup_args {
>+	aufs_bindex_t btgt;
>+	unsigned char isdir, did_cpup; /* flags */
>+	unsigned char hinotify;
>+	struct dentry *parent, *gparent, *h_dentry;
>+	struct inode *dir, *gdir, *h_inode, *h_dir;
>+};
>+
>+static int au_lock_and_icpup(struct dentry *dentry, loff_t sz,
>+			     struct au_icpup_args *rargs)
>+{
>+	int err;
>+	aufs_bindex_t bstart;
>+	struct super_block *sb;
>+	struct dentry *hi_wh;
>+	struct inode *inode;
>+	struct au_wr_dir_args wr_dir_args = {
>+		.force_btgt	= -1,
>+		.flags		= 0
>+	};
>+
>+	LKTRTrace("%.*s, %lld\n", AuDLNPair(dentry), sz);
>+
>+	di_write_lock_child(dentry);
>+	bstart = au_dbstart(dentry);
>+	sb = dentry->d_sb;
>+	inode = dentry->d_inode;
>+	rargs->isdir = S_ISDIR(inode->i_mode);
>+	if (rargs->isdir)
>+		au_fset_wrdir(wr_dir_args.flags, ISDIR);
>+	err = au_wr_dir(dentry, /*src_dentry*/NULL, &wr_dir_args);
>+	//err = -1;
>+	if (unlikely(err < 0))
>+		goto out_dentry;
>+	rargs->btgt = err;
>+	rargs->did_cpup = (err != bstart);
>+	err = 0;
>+
>+	/* crazy udba locks */
>+	rargs->hinotify = !!au_opt_test(au_mntflags(sb), UDBA_INOTIFY);
>+	if (unlikely(!IS_ROOT(dentry))) {
>+		rargs->parent = dget_parent(dentry);
>+		rargs->dir = rargs->parent->d_inode;
>+		di_read_lock_parent(rargs->parent, AuLock_IR);
>+	}
>+	rargs->h_dentry = au_h_dptr(dentry, au_dbstart(dentry));
>+	rargs->h_inode = rargs->h_dentry->d_inode;
>+	AuDebugOn(!rargs->h_inode);
>+
>+	if (!rargs->did_cpup) {
>+		au_hi_lock(rargs->h_inode, rargs->isdir, inode, rargs->btgt);
>+		//todo: revalidate the lower dentry?
>+		goto out; /* success */
>+	}
>+
>+	if (unlikely(rargs->hinotify
>+		     && rargs->parent
>+		     && !IS_ROOT(rargs->parent))) {
>+		rargs->gparent = dget_parent(rargs->parent);
>+		rargs->gdir = rargs->gparent->d_inode;
>+		ii_read_lock_parent2(rargs->gdir);
>+	}
>+
>+	hi_wh = NULL;
>+	rargs->h_dir = au_h_iptr(rargs->dir, rargs->btgt);
>+	au_hdir_lock(rargs->h_dir, rargs->dir, rargs->btgt);
>+	//todo: revalidate the lower dentry?
>+	au_hi_lock(rargs->h_inode, rargs->isdir, inode, bstart);
>+	if (!d_unhashed(dentry)) {
>+		err = au_sio_cpup_simple(dentry, rargs->btgt, sz, AuCpup_DTIME);
>+		if (!err)
>+			rargs->h_dentry = au_h_dptr(dentry, au_dbstart(dentry));
>+	} else {
>+		hi_wh = au_hi_wh(inode, rargs->btgt);
>+		if (!hi_wh) {
>+			err = au_sio_cpup_wh(dentry, rargs->btgt, sz,
>+					     /*file*/NULL);
>+			if (!err)
>+				hi_wh = au_hi_wh(inode, rargs->btgt);
>+		}
>+		if (!hi_wh)
>+			rargs->h_dentry = au_h_dptr(dentry, au_dbstart(dentry));
>+		else
>+			rargs->h_dentry = hi_wh; /* do not dget here */
>+	}
>+
>+	//err = -1;
>+	au_hi_unlock(rargs->h_inode, rargs->isdir, inode, bstart);
>+	rargs->h_inode = rargs->h_dentry->d_inode;
>+	AuDebugOn(!rargs->h_inode);
>+	if (!err)
>+		au_hi_lock(rargs->h_inode, rargs->isdir, inode, rargs->btgt);
>+	au_hdir_unlock(rargs->h_dir, rargs->dir, rargs->btgt);
>+	if (!err)
>+		goto out; /* success */
>+
>+	au_hi_unlock(rargs->h_inode, rargs->isdir, inode, rargs->btgt);
>+	if (unlikely(rargs->gdir)) {
>+		ii_read_unlock(rargs->gdir);
>+		dput(rargs->gparent);
>+	}
>+	if (unlikely(rargs->dir)) {
>+		di_read_unlock(rargs->parent, AuLock_IR);
>+		dput(rargs->parent);
>+	}
>+
>+ out_dentry:
>+	di_write_unlock(dentry);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int aufs_setattr(struct dentry *dentry, struct iattr *ia)
>+{
>+	int err;
>+	struct inode *inode;
>+	struct au_hin_ignore ign;
>+	struct vfsub_args vargs;
>+	struct super_block *sb;
>+	__u32 events;
>+	struct file *file;
>+	loff_t sz;
>+	struct au_icpup_args rargs;
>+
>+	LKTRTrace("%.*s, ia_valid 0x%x\n", AuDLNPair(dentry), ia->ia_valid);
>+	inode = dentry->d_inode;
>+	IMustLock(inode);
>+
>+	sb = dentry->d_sb;
>+	si_read_lock(sb, AuLock_FLUSH);
>+
>+	file = NULL;
>+	if (ia->ia_valid & ATTR_FILE) {
>+		/* currently ftruncate(2) only */
>+		file = ia->ia_file;
>+		fi_write_lock(file);
>+		ia->ia_file = au_h_fptr(file, au_fbstart(file));
>+	}
>+
>+	sz = -1;
>+	if ((ia->ia_valid & ATTR_SIZE)
>+	    && ia->ia_size < i_size_read(inode))
>+		sz = ia->ia_size;
>+	memset(&rargs, 0, sizeof(rargs));
>+	err = au_lock_and_icpup(dentry, sz, &rargs);
>+	if (unlikely(err < 0))
>+		goto out;
>+
>+	if ((ia->ia_valid & ATTR_SIZE)
>+	    && ia->ia_size < i_size_read(inode)) {
>+		err = vmtruncate(inode, ia->ia_size);
>+		if (unlikely(err))
>+			goto out_unlock;
>+	}
>+
>+	if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
>+		ia->ia_valid &= ~ATTR_MODE;
>+
>+	events = 0;
>+	vfsub_args_init(&vargs, &ign, au_opt_test_dlgt(au_mntflags(sb)), 0);
>+	if (unlikely(rargs.hinotify && rargs.dir)) {
>+		events = vfsub_events_notify_change(ia);
>+		if (events)
>+			vfsub_ign_hinode(&vargs, events,
>+					 au_hi(rargs.dir, rargs.btgt));
>+	}
>+	err = vfsub_notify_change(rargs.h_dentry, ia, &vargs);
>+	//err = -1;
>+	if (!err)
>+		au_cpup_attr_changeable(inode);
>+
>+ out_unlock:
>+	au_hi_unlock(rargs.h_inode, rargs.isdir, inode, rargs.btgt);
>+	if (unlikely(rargs.gdir)) {
>+		ii_read_unlock(rargs.gdir);
>+		dput(rargs.gparent);
>+	}
>+	if (unlikely(rargs.dir)) {
>+		di_read_unlock(rargs.parent, AuLock_IR);
>+		dput(rargs.parent);
>+	}
>+	di_write_unlock(dentry);
>+ out:
>+	if (file) {
>+		ia->ia_file = file;
>+		//ia->ia_valid |= ATTR_FILE;
>+		fi_write_unlock(file);
>+	}
>+	si_read_unlock(sb);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int h_readlink(struct dentry *dentry, int bindex, char __user *buf,
>+		      int bufsiz)
>+{
>+	struct super_block *sb;
>+	struct dentry *h_dentry;
>+
>+	LKTRTrace("%.*s, b%d, %d\n", AuDLNPair(dentry), bindex, bufsiz);
>+
>+	h_dentry = au_h_dptr(dentry, bindex);
>+	if (unlikely(!h_dentry->d_inode->i_op
>+		     || !h_dentry->d_inode->i_op->readlink))
>+		return -EINVAL;
>+
>+	sb = dentry->d_sb;
>+	if (!au_test_ro(sb, bindex, dentry->d_inode)) {
>+		touch_atime(au_sbr_mnt(sb, bindex), h_dentry);
>+		au_update_fuse_h_inode(NULL, h_dentry); /*ignore*/
>+		fsstack_copy_attr_atime(dentry->d_inode, h_dentry->d_inode);
>+	}
>+	return h_dentry->d_inode->i_op->readlink(h_dentry, buf, bufsiz);
>+}
>+
>+static int aufs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
>+{
>+	int err;
>+
>+	LKTRTrace("%.*s, %d\n", AuDLNPair(dentry), bufsiz);
>+
>+	aufs_read_lock(dentry, AuLock_IR);
>+	err = h_readlink(dentry, au_dbstart(dentry), buf, bufsiz);
>+	//err = -1;
>+	aufs_read_unlock(dentry, AuLock_IR);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static void *aufs_follow_link(struct dentry *dentry, struct nameidata *nd)
>+{
>+	int err;
>+	char *buf;
>+	mm_segment_t old_fs;
>+
>+	LKTRTrace("%.*s, nd %.*s\n",
>+		  AuDLNPair(dentry), AuDLNPair(nd->path.dentry));
>+
>+	err = -ENOMEM;
>+	buf = __getname();
>+	//buf = NULL;
>+	if (unlikely(!buf))
>+		goto out;
>+
>+	aufs_read_lock(dentry, AuLock_IR);
>+	old_fs = get_fs();
>+	set_fs(KERNEL_DS);
>+	err = h_readlink(dentry, au_dbstart(dentry), (char __user *)buf,
>+			 PATH_MAX);
>+	//err = -1;
>+	set_fs(old_fs);
>+	aufs_read_unlock(dentry, AuLock_IR);
>+
>+	if (err >= 0) {
>+		buf[err] = 0;
>+		/* will be freed by put_link */
>+		nd_set_link(nd, buf);
>+		return NULL; /* success */
>+	}
>+	__putname(buf);
>+
>+ out:
>+	path_put(&nd->path);
>+	AuTraceErr(err);
>+	return ERR_PTR(err);
>+}
>+
>+static void aufs_put_link(struct dentry *dentry, struct nameidata *nd,
>+			  void *cookie)
>+{
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	__putname(nd_get_link(nd));
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static void aufs_truncate_range(struct inode *inode, loff_t start, loff_t end)
>+{
>+	AuUnsupport();
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct inode_operations aufs_symlink_iop = {
>+	.permission	= aufs_permission,
>+	.setattr	= aufs_setattr,
>+#ifdef CONFIG_AUFS_WORKAROUND_FUSE
>+	.getattr	= aufs_getattr,
>+#endif
>+
>+	.readlink	= aufs_readlink,
>+	.follow_link	= aufs_follow_link,
>+	.put_link	= aufs_put_link
>+};
>+
>+struct inode_operations aufs_dir_iop = {
>+	.create		= aufs_create,
>+	.lookup		= aufs_lookup,
>+	.link		= aufs_link,
>+	.unlink		= aufs_unlink,
>+	.symlink	= aufs_symlink,
>+	.mkdir		= aufs_mkdir,
>+	.rmdir		= aufs_rmdir,
>+	.mknod		= aufs_mknod,
>+	.rename		= aufs_rename,
>+
>+	.permission	= aufs_permission,
>+	.setattr	= aufs_setattr,
>+#ifdef CONFIG_AUFS_WORKAROUND_FUSE
>+	.getattr	= aufs_getattr,
>+#endif
>+};
>+
>+struct inode_operations aufs_iop = {
>+	.permission	= aufs_permission,
>+	.setattr	= aufs_setattr,
>+#ifdef CONFIG_AUFS_WORKAROUND_FUSE
>+	.getattr	= aufs_getattr,
>+#endif
>+
>+	//void (*truncate) (struct inode *);
>+	.truncate_range	= aufs_truncate_range,
>+};
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/i_op_del.c linux-2.6.25.4-unionfs/fs/aufs/i_op_del.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/i_op_del.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/i_op_del.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,566 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * inode operations (del entry)
>+ *
>+ * $Id: i_op_del.c,v 1.4 2008/05/04 23:54:53 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+/* returns,
>+ * 0: wh is unnecessary
>+ * plus: wh is necessary
>+ * minus: error
>+ */
>+int au_wr_dir_need_wh(struct dentry *dentry, int isdir, aufs_bindex_t *bcpup,
>+		      struct dentry *locked)
>+{
>+	int need_wh, err;
>+	aufs_bindex_t bstart;
>+	struct dentry *h_dentry;
>+	struct super_block *sb;
>+
>+	LKTRTrace("%.*s, isdir %d, *bcpup %d, locked %p\n",
>+		  AuDLNPair(dentry), isdir, *bcpup, locked);
>+	sb = dentry->d_sb;
>+
>+	bstart = au_dbstart(dentry);
>+	LKTRTrace("bcpup %d, bstart %d\n", *bcpup, bstart);
>+	h_dentry = au_h_dptr(dentry, bstart);
>+	if (*bcpup < 0) {
>+		*bcpup = bstart;
>+		if (au_test_ro(sb, bstart, dentry->d_inode)) {
>+			err = AuWbrCopyup(au_sbi(sb), dentry);
>+			*bcpup = err;
>+			//err = -1;
>+			if (unlikely(err < 0))
>+				goto out;
>+		}
>+	} else
>+		AuDebugOn(bstart < *bcpup
>+			  || au_test_ro(sb, *bcpup, dentry->d_inode));
>+	LKTRTrace("bcpup %d, bstart %d\n", *bcpup, bstart);
>+
>+	if (*bcpup != bstart) {
>+		err = au_cpup_dirs(dentry, *bcpup, locked);
>+		//err = -1;
>+		if (unlikely(err))
>+			goto out;
>+		need_wh = 1;
>+	} else {
>+		//struct nameidata nd;
>+		aufs_bindex_t old_bend, new_bend, bdiropq = -1;
>+		old_bend = au_dbend(dentry);
>+		if (isdir) {
>+			bdiropq = au_dbdiropq(dentry);
>+			au_set_dbdiropq(dentry, -1);
>+		}
>+		need_wh = au_lkup_dentry(dentry, bstart + 1, /*type*/0,
>+					 /*nd*/NULL);
>+		err = need_wh;
>+		//err = -1;
>+		if (isdir)
>+			au_set_dbdiropq(dentry, bdiropq);
>+		if (unlikely(err < 0))
>+			goto out;
>+		new_bend = au_dbend(dentry);
>+		if (!need_wh && old_bend != new_bend) {
>+			au_set_h_dptr(dentry, new_bend, NULL);
>+			au_set_dbend(dentry, old_bend);
>+		}
>+	}
>+	LKTRTrace("need_wh %d\n", need_wh);
>+	err = need_wh;
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * simple tests for the removal inode operations.
>+ * following the checks in vfs, plus the parent-child relationship.
>+ */
>+int au_may_del(struct dentry *dentry, aufs_bindex_t bindex,
>+	       struct dentry *h_parent, int isdir, struct au_ndx *ndx)
>+{
>+	int err, exist;
>+	struct super_block *sb;
>+	struct dentry *h_dentry;
>+	struct inode *h_inode;
>+	umode_t h_mode;
>+
>+	LKTRTrace("%.*s/%.*s, b%d, dir %d\n",
>+		  AuDLNPair(h_parent), AuDLNPair(dentry), bindex, isdir);
>+
>+	sb = dentry->d_sb;
>+	exist = !!dentry->d_inode;
>+	h_dentry = au_h_dptr(dentry, bindex);
>+	h_inode = h_dentry->d_inode;
>+	if (exist) {
>+		err = -ENOENT;
>+		if (unlikely(!h_inode || !h_inode->i_nlink))
>+			goto out;
>+
>+		h_mode = h_inode->i_mode;
>+		if (!isdir) {
>+			err = -EISDIR;
>+			if (unlikely(S_ISDIR(h_mode)))
>+				goto out;
>+		} else if (unlikely(!S_ISDIR(h_mode))) {
>+			err = -ENOTDIR;
>+			goto out;
>+		}
>+	} else {
>+		/* rename(2) case */
>+		err = -EIO;
>+		if (unlikely(h_inode))
>+			goto out;
>+	}
>+
>+	err = -ENOENT;
>+	/* expected parent dir is locked */
>+	if (unlikely(h_parent != h_dentry->d_parent))
>+		goto out;
>+	err = 0;
>+
>+	/*
>+	 * some filesystem may unlink a dir and corrupt its consistency.
>+	 * so let's try heavy test.
>+	 */
>+	if (1 /*unlikely(au_opt_test(au_mntflags(sb), UDBA_INOTIFY))*/) {
>+		struct dentry *h_latest;
>+		struct qstr *qstr = &dentry->d_name;
>+
>+		err = -EACCES;
>+		if (unlikely(au_test_h_perm(h_parent->d_inode,
>+					    MAY_EXEC | MAY_WRITE,
>+					    au_ftest_ndx(ndx->flags, DLGT))))
>+			goto out;
>+
>+		h_latest = au_sio_lkup_one(qstr->name, h_parent, qstr->len,
>+					   ndx);
>+		//err = PTR_ERR(h_latest);
>+		err = -EIO;
>+		if (IS_ERR(h_latest))
>+			goto out;
>+		dput(h_latest);
>+		if (h_latest == h_dentry)
>+			err = 0;
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static struct dentry *
>+lock_hdir_create_wh(struct dentry *dentry, int isdir, aufs_bindex_t *rbcpup,
>+		    struct au_dtime *dt)
>+{
>+	struct dentry *wh_dentry;
>+	int err, need_wh;
>+	struct dentry *h_parent, *parent, *gparent;
>+	struct inode *dir, *h_dir, *gdir;
>+	struct au_ndx ndx;
>+	struct super_block *sb;
>+	struct au_hinode *hgdir;
>+	aufs_bindex_t bcpup;
>+	unsigned int mnt_flags;
>+
>+	LKTRTrace("%.*s, isdir %d\n", AuDLNPair(dentry), isdir);
>+
>+	need_wh = au_wr_dir_need_wh(dentry, isdir, rbcpup, NULL);
>+	err = need_wh;
>+	//err = -1;
>+	wh_dentry = ERR_PTR(err);
>+	if (unlikely(err < 0))
>+		goto out;
>+
>+	//todo: meaningless lock if CONFIG_AUFS_DEBUG is disabled.
>+	hgdir = NULL;
>+	bcpup = *rbcpup;
>+	sb = dentry->d_sb;
>+	mnt_flags = au_mntflags(sb);
>+	parent = dentry->d_parent; /* dir inode is locked */
>+	if (unlikely(au_opt_test(mnt_flags, UDBA_INOTIFY)
>+		     && !IS_ROOT(parent))) {
>+		gparent = dget_parent(parent);
>+		gdir = gparent->d_inode;
>+		ii_read_lock_parent2(gdir);
>+		hgdir = au_hi(gdir, bcpup);
>+		ii_read_unlock(gdir);
>+		dput(gparent);
>+	}
>+	dir = parent->d_inode;
>+	IMustLock(dir);
>+	h_parent = au_h_dptr(parent, bcpup);
>+	h_dir = h_parent->d_inode;
>+
>+	AuDbgSleep_UdbaRace();
>+	au_hdir_lock(h_dir, dir, bcpup);
>+	//todo: revalidate the lower dentry?
>+
>+	if (!au_opt_test(mnt_flags, UDBA_NONE) && au_dbstart(dentry) == bcpup) {
>+		ndx.nfsmnt = au_nfsmnt(sb, bcpup);
>+		ndx.flags = 0;
>+		if (unlikely(au_opt_test_dlgt(mnt_flags)))
>+			au_fset_ndx(ndx.flags, DLGT);
>+		ndx.nd = NULL;
>+		//ndx.br = au_sbr(sb, bcpup);
>+		//ndx.nd_file = NULL;
>+		err = au_may_del(dentry, bcpup, h_parent, isdir, &ndx);
>+		wh_dentry = ERR_PTR(err);
>+		if (unlikely(err))
>+			goto out_dir;
>+	}
>+
>+	au_dtime_store(dt, parent, h_parent, hgdir);
>+	wh_dentry = NULL;
>+	if (!need_wh)
>+		goto out; /* success, no need to create whiteout */
>+
>+	ndx.nfsmnt = au_nfsmnt(sb, bcpup);
>+	ndx.flags = 0;
>+	if (unlikely(au_opt_test_dlgt(mnt_flags)))
>+		au_fset_ndx(ndx.flags, DLGT);
>+	ndx.nd = NULL;
>+	//ndx.br = NULL;
>+	wh_dentry = au_wh_create(dir, dentry, bcpup, h_parent, &ndx);
>+	//wh_dentry = ERR_PTR(-1);
>+	if (!IS_ERR(wh_dentry))
>+		goto out; /* success */
>+	/* returns with the parent is locked and wh_dentry is DGETed */
>+
>+ out_dir:
>+	au_hdir_unlock(h_dir, dir, bcpup);
>+ out:
>+	AuTraceErrPtr(wh_dentry);
>+	return wh_dentry;
>+}
>+
>+static int renwh_and_rmdir(struct dentry *dentry, aufs_bindex_t bindex,
>+			   struct au_nhash *whlist, struct inode *dir)
>+{
>+	int rmdir_later, err;
>+	struct dentry *h_dentry;
>+	struct inode *inode, *h_inode;
>+	struct super_block *sb;
>+
>+	LKTRTrace("%.*s, b%d\n", AuDLNPair(dentry), bindex);
>+
>+	inode = NULL;
>+	h_inode = NULL;
>+	sb = dentry->d_sb;
>+	if (unlikely(au_opt_test(au_mntflags(sb), UDBA_INOTIFY))) {
>+		inode = dentry->d_inode;
>+		h_inode = au_h_iptr(inode, bindex);
>+		au_hdir2_lock(h_inode, inode, bindex);
>+	}
>+	err = au_whtmp_ren(dir, dentry, bindex, /*noself*/1);
>+	if (unlikely(inode))
>+		au_hdir_unlock(h_inode, inode, bindex);
>+	//err = -1;
>+	if (unlikely(err))
>+		goto out;
>+
>+	h_dentry = au_h_dptr(dentry, bindex);
>+	if (!au_test_nfs(h_dentry->d_sb)) {
>+		const int dirwh = au_sbi(sb)->si_dirwh;
>+		rmdir_later = (dirwh <= 1);
>+		if (!rmdir_later)
>+			rmdir_later = au_nhash_test_longer_wh(whlist, bindex,
>+							      dirwh);
>+		if (rmdir_later)
>+			return rmdir_later;
>+	}
>+
>+	err = au_whtmp_rmdir(h_dentry, whlist, bindex, dir, dentry->d_inode,
>+			     /*noself*/1);
>+	//err = -1;
>+	if (unlikely(err)) {
>+		AuIOErr("rmdir %.*s, b%d failed, %d. ignored\n",
>+			AuDLNPair(h_dentry), bindex, err);
>+		err = 0;
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static void epilog(struct inode *dir, struct dentry *dentry,
>+		   aufs_bindex_t bindex)
>+{
>+	//todo: unnecessary?
>+	d_drop(dentry);
>+	dentry->d_inode->i_ctime = dir->i_ctime;
>+
>+	if (atomic_read(&dentry->d_count) == 1) {
>+		au_set_h_dptr(dentry, au_dbstart(dentry), NULL);
>+		au_update_dbstart(dentry);
>+	}
>+	if (au_ibstart(dir) == bindex)
>+		au_cpup_attr_timesizes(dir);
>+	dir->i_version++;
>+}
>+
>+/* revert flags */
>+#define AuRev_DLGT	1
>+#define au_ftest_rev(flags, name)	((flags) & AuRev_##name)
>+#define au_fset_rev(flags, name)	{ (flags) |= AuRev_##name; }
>+#define au_fclr_rev(flags, name)	{ (flags) &= ~AuRev_##name; }
>+#ifndef CONFIG_AUFS_DLGT
>+#undef AuRev_DLGT
>+#define AuRev_DLGT	0
>+#endif
>+
>+static int do_revert(int err, struct dentry *wh_dentry, struct dentry *dentry,
>+		     aufs_bindex_t bwh, struct au_dtime *dt, unsigned int flags)
>+{
>+	int rerr;
>+	struct inode *dir;
>+
>+	dir = wh_dentry->d_parent->d_inode; /* dir inode is locked */
>+	IMustLock(dir);
>+	rerr = au_wh_unlink_dentry(dir, wh_dentry, dentry, dir,
>+				   au_ftest_rev(flags, DLGT));
>+	//rerr = -1;
>+	if (!rerr) {
>+		au_set_dbwh(dentry, bwh);
>+		au_dtime_revert(dt);
>+		return 0;
>+	}
>+
>+	AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
>+		AuDLNPair(dentry), err, rerr);
>+	return -EIO;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int aufs_unlink(struct inode *dir, struct dentry *dentry)
>+{
>+	int err, dlgt;
>+	struct inode *inode, *h_dir;
>+	struct dentry *parent, *wh_dentry, *h_dentry;
>+	struct au_dtime dt;
>+	aufs_bindex_t bwh, bindex, bstart;
>+	struct super_block *sb;
>+	struct vfsub_args vargs;
>+
>+	LKTRTrace("i%lu, %.*s\n", dir->i_ino, AuDLNPair(dentry));
>+	IMustLock(dir);
>+	inode = dentry->d_inode;
>+	if (unlikely(!inode))
>+		return -ENOENT; /* possible? */
>+	IMustLock(inode);
>+
>+	aufs_read_lock(dentry, AuLock_DW);
>+	parent = dentry->d_parent; /* dir inode is locked */
>+	di_write_lock_parent(parent);
>+
>+	bstart = au_dbstart(dentry);
>+	bwh = au_dbwh(dentry);
>+	bindex = -1;
>+	wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/0, &bindex, &dt);
>+	//wh_dentry = ERR_PTR(-1);
>+	err = PTR_ERR(wh_dentry);
>+	if (IS_ERR(wh_dentry))
>+		goto out;
>+
>+	sb = dir->i_sb;
>+	dlgt = !!au_opt_test_dlgt(au_mntflags(sb));
>+	AuDebugOn(au_dbstart(dentry) != bstart);
>+	h_dentry = au_h_dptr(dentry, bstart);
>+	dget(h_dentry);
>+
>+	if (bindex == bstart) {
>+		vfsub_args_init(&vargs, NULL, dlgt, 0);
>+		h_dir = h_dentry->d_parent->d_inode; /* dir inode is locked */
>+		IMustLock(h_dir);
>+		err = vfsub_unlink(h_dir, h_dentry, &vargs);
>+		//err = -1;
>+	} else {
>+		/* dir inode is locked */
>+		AuDebugOn(!wh_dentry
>+			  || wh_dentry->d_parent != au_h_dptr(parent, bindex));
>+		h_dir = wh_dentry->d_parent->d_inode;
>+		IMustLock(h_dir);
>+		err = 0;
>+	}
>+
>+	if (!err) {
>+		drop_nlink(inode);
>+		epilog(dir, dentry, bindex);
>+
>+		/* update target timestamps */
>+		if (bindex == bstart) {
>+			au_update_fuse_h_inode(NULL, h_dentry); /*ignore*/
>+			inode->i_ctime = h_dentry->d_inode->i_ctime;
>+		} else
>+			//todo: this timestamp may be reverted later
>+			inode->i_ctime = h_dir->i_ctime;
>+		goto out_unlock; /* success */
>+	}
>+
>+	/* revert */
>+	if (wh_dentry) {
>+		int rerr;
>+		unsigned int rev_flags;
>+
>+		rev_flags = 0;
>+		if (unlikely(dlgt))
>+			au_fset_rev(rev_flags, DLGT);
>+		rerr = do_revert(err, wh_dentry, dentry, bwh, &dt, rev_flags);
>+		if (rerr)
>+			err = rerr;
>+	}
>+
>+ out_unlock:
>+	au_hdir_unlock(h_dir, dir, bindex);
>+	dput(wh_dentry);
>+	dput(h_dentry);
>+ out:
>+	di_write_unlock(parent);
>+	aufs_read_unlock(dentry, AuLock_DW);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int aufs_rmdir(struct inode *dir, struct dentry *dentry)
>+{
>+	int err, rmdir_later;
>+	struct inode *inode, *h_dir;
>+	struct dentry *parent, *wh_dentry, *h_dentry;
>+	struct au_dtime dt;
>+	aufs_bindex_t bwh, bindex, bstart;
>+	struct au_whtmp_rmdir_args *args;
>+	struct au_nhash *whlist;
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+
>+	LKTRTrace("i%lu, %.*s\n", dir->i_ino, AuDLNPair(dentry));
>+	IMustLock(dir);
>+	inode = dentry->d_inode;
>+	if (unlikely(!inode))
>+		return -ENOENT; /* possible? */
>+	IMustLock(inode);
>+
>+	whlist = au_nhash_new(GFP_TEMPORARY);
>+	err = PTR_ERR(whlist);
>+	if (IS_ERR(whlist))
>+		goto out;
>+
>+	err = -ENOMEM;
>+	args = kmalloc(sizeof(*args), GFP_TEMPORARY);
>+	//args = NULL;
>+	if (unlikely(!args))
>+		goto out_whlist;
>+
>+	aufs_read_lock(dentry, AuLock_DW);
>+	parent = dentry->d_parent; /* dir inode is locked */
>+	di_write_lock_parent(parent);
>+	err = au_test_empty(dentry, whlist);
>+	//err = -1;
>+	if (unlikely(err))
>+		goto out_args;
>+
>+	bstart = au_dbstart(dentry);
>+	bwh = au_dbwh(dentry);
>+	bindex = -1;
>+	wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/1, &bindex, &dt);
>+	//wh_dentry = ERR_PTR(-1);
>+	err = PTR_ERR(wh_dentry);
>+	if (IS_ERR(wh_dentry))
>+		goto out_args;
>+
>+	AuDebugOn(au_dbstart(dentry) != bstart);
>+	h_dentry = au_h_dptr(dentry, bstart);
>+	dget(h_dentry);
>+
>+	rmdir_later = 0;
>+	if (bindex == bstart) {
>+		h_dir = h_dentry->d_parent->d_inode; /* dir inode is locked */
>+		IMustLock(h_dir);
>+		err = renwh_and_rmdir(dentry, bstart, whlist, dir);
>+		//err = -1;
>+		if (err > 0) {
>+			rmdir_later = err;
>+			err = 0;
>+		}
>+	} else {
>+		/* dir inode is locked */
>+		AuDebugOn(!wh_dentry
>+			  || wh_dentry->d_parent != au_h_dptr(parent, bindex));
>+		h_dir = wh_dentry->d_parent->d_inode;
>+		IMustLock(h_dir);
>+		err = 0;
>+	}
>+
>+	sb = dentry->d_sb;
>+	mnt_flags = au_mntflags(sb);
>+	if (!err) {
>+		//aufs_bindex_t bi, bend;
>+
>+		if (unlikely(au_opt_test(mnt_flags, UDBA_INOTIFY)
>+			     && rmdir_later))
>+			au_reset_hinotify(inode, /*flags*/0);
>+		clear_nlink(inode);
>+		au_set_dbdiropq(dentry, -1);
>+		epilog(dir, dentry, bindex);
>+
>+		if (rmdir_later) {
>+			au_whtmp_kick_rmdir(h_dentry, whlist, bstart, dir,
>+					    inode, /*noself*/1, args);
>+			args = NULL;
>+		}
>+
>+		goto out_unlock; /* success */
>+	}
>+
>+	/* revert */
>+	LKTRLabel(revert);
>+	if (wh_dentry) {
>+		int rerr;
>+		unsigned int rev_flags;
>+
>+		rev_flags = 0;
>+		if (unlikely(au_opt_test_dlgt(mnt_flags)))
>+			au_fset_rev(rev_flags, DLGT);
>+		rerr = do_revert(err, wh_dentry, dentry, bwh, &dt, rev_flags);
>+		if (rerr)
>+			err = rerr;
>+	}
>+
>+ out_unlock:
>+	au_hdir_unlock(h_dir, dir, bindex);
>+	dput(wh_dentry);
>+	dput(h_dentry);
>+ out_args:
>+	di_write_unlock(parent);
>+	aufs_read_unlock(dentry, AuLock_DW);
>+	kfree(args);
>+ out_whlist:
>+	au_nhash_del(whlist);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/i_op_ren.c linux-2.6.25.4-unionfs/fs/aufs/i_op_ren.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/i_op_ren.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/i_op_ren.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,812 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * inode operation (rename entry)
>+ * todo: this is monster
>+ *
>+ * $Id: i_op_ren.c,v 1.4 2008/05/04 23:51:40 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+enum { SRC, DST };
>+
>+#define AuRen_ISDIR	1
>+#define AuRen_ISSAMEDIR	(1 << 1)
>+#define AuRen_WHSRC	(1 << 2)
>+#define AuRen_WHDST	(1 << 3)
>+#define AuRen_DLGT	(1 << 4)
>+#define au_ftest_ren(flags, name)	((flags) & AuRen_##name)
>+#define au_fset_ren(flags, name)	{ (flags) |= AuRen_##name; }
>+#define au_fclr_ren(flags, name)	{ (flags) &= ~AuRen_##name; }
>+#ifndef CONFIG_AUFS_DLGT
>+#undef AuRen_DLGT
>+#define AuRen_DLGT	0
>+#endif
>+
>+struct rename_args {
>+	struct dentry *h_dentry[2], *parent[2], *h_parent[2], *h_trap;
>+	struct au_nhash whlist;
>+	aufs_bindex_t btgt, bstart[2];
>+	struct super_block *sb;
>+	unsigned int flags;
>+	unsigned int mnt_flags;
>+};
>+
>+static noinline_for_stack int
>+do_rename(struct inode *src_dir, struct dentry *src_dentry,
>+	  struct inode *dir, struct dentry *dentry, struct rename_args *a)
>+{
>+	int err, need_diropq, bycpup, rerr;
>+	struct au_whtmp_rmdir_args *thargs;
>+	struct dentry *wh_dentry[2], *h_dst, *h_src;
>+	struct inode *h_dir[2];
>+	aufs_bindex_t bindex, bend;
>+	struct au_hin_ignore ign;
>+	struct vfsub_args vargs;
>+	struct au_ndx ndx = {
>+		.flags	= 0,
>+		.nd	= NULL,
>+		//.br	= NULL
>+	};
>+
>+	LKTRTrace("%.*s/%.*s, %.*s/%.*s, "
>+		  "hd{%p, %p}, hp{%p, %p}, wh %p, btgt %d, bstart{%d, %d}, "
>+		  "flags 0x%x\n",
>+		  AuDLNPair(a->parent[SRC]), AuDLNPair(src_dentry),
>+		  AuDLNPair(a->parent[DST]), AuDLNPair(dentry),
>+		  a->h_dentry[SRC], a->h_dentry[DST],
>+		  a->h_parent[SRC], a->h_parent[DST],
>+		  &a->whlist, a->btgt,
>+		  a->bstart[SRC], a->bstart[DST],
>+		  a->flags);
>+
>+	h_dir[SRC] = a->h_parent[SRC]->d_inode;
>+	h_dir[DST] = a->h_parent[DST]->d_inode;
>+
>+	/* prepare workqueue args */
>+	h_dst = NULL;
>+	thargs = NULL;
>+	if (au_ftest_ren(a->flags, ISDIR) && a->h_dentry[DST]->d_inode) {
>+		err = -ENOMEM;
>+		thargs = kmalloc(sizeof(*thargs), GFP_TEMPORARY);
>+		//thargs = NULL;
>+		if (unlikely(!thargs))
>+			goto out;
>+		h_dst = dget(a->h_dentry[DST]);
>+	}
>+
>+	wh_dentry[SRC] = NULL;
>+	wh_dentry[DST] = NULL;
>+	ndx.nfsmnt = au_nfsmnt(a->sb, a->btgt);
>+	if (unlikely(au_ftest_ren(a->flags, DLGT)))
>+		au_fset_ndx(ndx.flags, DLGT);
>+
>+	/* create whiteout for src_dentry */
>+	if (au_ftest_ren(a->flags, WHSRC)) {
>+		wh_dentry[SRC] = au_wh_create(src_dir, src_dentry, a->btgt,
>+					      a->h_parent[SRC], &ndx);
>+		//wh_dentry[SRC] = ERR_PTR(-1);
>+		err = PTR_ERR(wh_dentry[SRC]);
>+		if (IS_ERR(wh_dentry[SRC]))
>+			goto out_thargs;
>+	}
>+
>+	/* lookup whiteout for dentry */
>+	if (au_ftest_ren(a->flags, WHDST)) {
>+		struct dentry *d;
>+
>+		d = au_wh_lkup(a->h_parent[DST], &dentry->d_name, &ndx);
>+		//d = ERR_PTR(-1);
>+		err = PTR_ERR(d);
>+		if (IS_ERR(d))
>+			goto out_whsrc;
>+		if (!d->d_inode)
>+			dput(d);
>+		else
>+			wh_dentry[DST] = d;
>+	}
>+
>+	/* rename dentry to tmpwh */
>+	if (thargs) {
>+		err = au_whtmp_ren(dir, dentry, a->btgt, /*noself*/0);
>+		//err = -1;
>+		if (unlikely(err))
>+			goto out_whdst;
>+		au_set_h_dptr(dentry, a->btgt, NULL);
>+		err = au_lkup_neg(dentry, a->btgt);
>+		//err = -1;
>+		if (unlikely(err))
>+			goto out_whtmp;
>+		a->h_dentry[DST] = au_h_dptr(dentry, a->btgt);
>+	}
>+
>+	/* cpup src */
>+	if (a->h_dentry[DST]->d_inode && a->bstart[SRC] != a->btgt) {
>+		mutex_lock_nested(&a->h_dentry[SRC]->d_inode->i_mutex,
>+				  AuLsc_I_CHILD);
>+		err = au_sio_cpup_simple(src_dentry, a->btgt, -1,
>+					 !AuCpup_DTIME);
>+		//err = -1; // untested dir
>+		mutex_unlock(&a->h_dentry[SRC]->d_inode->i_mutex);
>+		if (unlikely(err))
>+			goto out_whtmp;
>+	}
>+
>+	/* rename by vfs_rename or cpup */
>+	need_diropq = au_ftest_ren(a->flags, ISDIR)
>+		&& (wh_dentry[DST]
>+		    || au_dbdiropq(dentry) == a->btgt
>+		    /* hide the lower to keep xino */
>+		    || a->btgt < au_dbend(dentry)
>+		    || au_opt_test(a->mnt_flags, ALWAYS_DIROPQ));
>+	bycpup = 0;
>+	if (au_dbstart(src_dentry) == a->btgt) {
>+		if (need_diropq && au_dbdiropq(src_dentry) == a->btgt)
>+			need_diropq = 0;
>+		vfsub_args_init(&vargs, &ign, au_ftest_ren(a->flags, DLGT), 0);
>+		if (unlikely(au_opt_test(a->mnt_flags, UDBA_INOTIFY)
>+			     && au_ftest_ren(a->flags, ISDIR)))
>+			vfsub_ign_hinode(&vargs, IN_MOVE_SELF,
>+					 au_hi(src_dentry->d_inode, a->btgt));
>+		AuDebugOn(au_dbstart(src_dentry) != a->btgt);
>+		err = vfsub_rename(h_dir[SRC], au_h_dptr(src_dentry, a->btgt),
>+				   h_dir[DST], a->h_dentry[DST], &vargs);
>+		//err = -1;
>+	} else {
>+		bycpup = 1;
>+		mutex_lock_nested(&a->h_dentry[SRC]->d_inode->i_mutex,
>+				  AuLsc_I_CHILD);
>+		au_set_dbstart(src_dentry, a->btgt);
>+		au_set_h_dptr(src_dentry, a->btgt, dget(a->h_dentry[DST]));
>+		err = au_sio_cpup_single(src_dentry, a->btgt, a->bstart[SRC],
>+					 -1, !AuCpup_DTIME);
>+		//err = -1; // untested dir
>+		if (unlikely(err)) {
>+			au_set_h_dptr(src_dentry, a->btgt, NULL);
>+			au_set_dbstart(src_dentry, a->bstart[SRC]);
>+		}
>+		mutex_unlock(&a->h_dentry[SRC]->d_inode->i_mutex);
>+	}
>+	if (unlikely(err))
>+		goto out_whtmp;
>+
>+	/* make dir opaque */
>+	if (need_diropq) {
>+		struct dentry *diropq;
>+		struct inode *h_inode;
>+
>+		h_inode = au_h_dptr(src_dentry, a->btgt)->d_inode;
>+		au_hdir_lock(h_inode, src_dentry->d_inode, a->btgt);
>+		diropq = au_diropq_create(src_dentry, a->btgt,
>+					  au_ftest_ren(a->flags, DLGT));
>+		//diropq = ERR_PTR(-1);
>+		au_hdir_unlock(h_inode, src_dentry->d_inode, a->btgt);
>+		err = PTR_ERR(diropq);
>+		if (IS_ERR(diropq))
>+			goto out_rename;
>+		dput(diropq);
>+	}
>+
>+	/* update target timestamps */
>+	AuDebugOn(au_dbstart(src_dentry) != a->btgt);
>+	h_src = au_h_dptr(src_dentry, a->btgt);
>+	au_update_fuse_h_inode(NULL, h_src); /*ignore*/
>+	//fsstack_copy_attr_atime(src_dentry->d_inode, h_src->d_inode);
>+	src_dentry->d_inode->i_ctime = h_src->d_inode->i_ctime;
>+
>+	/* remove whiteout for dentry */
>+	if (wh_dentry[DST]) {
>+		err = au_wh_unlink_dentry(h_dir[DST], wh_dentry[DST],
>+					  dentry, dir, /*dlgt*/0);
>+		//err = -1;
>+		if (unlikely(err))
>+			goto out_diropq;
>+	}
>+
>+	/* remove whtmp */
>+	if (thargs) {
>+		if (au_test_nfs(h_dst->d_sb)
>+		    || !au_nhash_test_longer_wh(&a->whlist, a->btgt,
>+						au_sbi(a->sb)->si_dirwh)) {
>+			err = au_whtmp_rmdir(h_dst, &a->whlist, a->btgt, dir,
>+					     dentry->d_inode, /*noself*/0);
>+			if (unlikely(err))
>+				AuWarn("failed removing whtmp dir %.*s (%d), "
>+				       "ignored.\n", AuDLNPair(h_dst), err);
>+		} else {
>+			au_whtmp_kick_rmdir(h_dst, &a->whlist, a->btgt, dir,
>+					    dentry->d_inode, /*noself*/0,
>+					    thargs);
>+			dput(h_dst);
>+			thargs = NULL;
>+		}
>+	}
>+	err = 0;
>+	goto out_success;
>+
>+#define RevertFailure(fmt, args...) do { \
>+		AuIOErrWhck("revert failure: " fmt " (%d, %d)\n", \
>+			    ##args, err, rerr); \
>+		err = -EIO; \
>+	} while (0)
>+
>+ out_diropq:
>+	if (need_diropq) {
>+		struct inode *h_inode;
>+
>+		h_inode = au_h_dptr(src_dentry, a->btgt)->d_inode;
>+		//br_wh_read_lock(au_sbr(a->sb, a->btgt));
>+		/* i_lock simply since inotify is not set to h_inode. */
>+		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_PARENT);
>+		//au_hdir_lock(h_inode, src_dentry->d_inode, a->btgt);
>+		rerr = au_diropq_remove(src_dentry, a->btgt,
>+					au_ftest_ren(a->flags, DLGT));
>+		//rerr = -1;
>+		//au_hdir_unlock(h_inode, src_dentry->d_inode, a->btgt);
>+		mutex_unlock(&h_inode->i_mutex);
>+		//br_wh_read_unlock(au_sbr(a->sb, a->btgt));
>+		if (rerr)
>+			RevertFailure("remove diropq %.*s",
>+				      AuDLNPair(src_dentry));
>+	}
>+ out_rename:
>+	if (!bycpup) {
>+		struct dentry *d;
>+		struct qstr *name = &src_dentry->d_name;
>+
>+		d = au_lkup_one(name->name, a->h_parent[SRC], name->len, &ndx);
>+		//d = ERR_PTR(-1);
>+		rerr = PTR_ERR(d);
>+		if (IS_ERR(d)) {
>+			RevertFailure("au_lkup_one %.*s",
>+				      AuDLNPair(src_dentry));
>+			goto out_whtmp;
>+		}
>+		AuDebugOn(d->d_inode);
>+		vfsub_args_init(&vargs, &ign, au_ftest_ren(a->flags, DLGT), 0);
>+		if (unlikely(au_opt_test(a->mnt_flags, UDBA_INOTIFY)
>+			     && au_ftest_ren(a->flags, ISDIR)))
>+			vfsub_ign_hinode(&vargs, IN_MOVE_SELF,
>+					 au_hi(src_dentry->d_inode, a->btgt));
>+		rerr = vfsub_rename(h_dir[DST], au_h_dptr(src_dentry, a->btgt),
>+				    h_dir[SRC], d, &vargs);
>+		//rerr = -1;
>+		d_drop(d);
>+		dput(d);
>+		//au_set_h_dptr(src_dentry, a->btgt, NULL);
>+		if (rerr)
>+			RevertFailure("rename %.*s", AuDLNPair(src_dentry));
>+	} else {
>+		vfsub_args_init(&vargs, NULL, au_ftest_ren(a->flags, DLGT), 0);
>+		rerr = vfsub_unlink(h_dir[DST], a->h_dentry[DST], &vargs);
>+		//rerr = -1;
>+		au_set_h_dptr(src_dentry, a->btgt, NULL);
>+		au_set_dbstart(src_dentry, a->bstart[SRC]);
>+		if (rerr)
>+			RevertFailure("unlink %.*s",
>+				      AuDLNPair(a->h_dentry[DST]));
>+	}
>+ out_whtmp:
>+	if (thargs) {
>+		struct dentry *d;
>+		struct qstr *name = &dentry->d_name;
>+
>+		d = au_lkup_one(name->name, a->h_parent[DST], name->len, &ndx);
>+		//d = ERR_PTR(-1);
>+		rerr = PTR_ERR(d);
>+		if (IS_ERR(d)) {
>+			RevertFailure("lookup %.*s", AuLNPair(name));
>+			goto out_whdst;
>+		}
>+		if (d->d_inode) {
>+			d_drop(d);
>+			dput(d);
>+			goto out_whdst;
>+		}
>+		AuDebugOn(d->d_inode);
>+		vfsub_args_init(&vargs, &ign, au_ftest_ren(a->flags, DLGT), 0);
>+		if (unlikely(0 && au_opt_test(a->mnt_flags, UDBA_INOTIFY)
>+			     && au_ftest_ren(a->flags, ISDIR)))
>+			vfsub_ign_hinode(&vargs, IN_MOVE_SELF,
>+					 au_hi(dentry->d_inode, a->btgt));
>+		rerr = vfsub_rename(h_dir[DST], h_dst, h_dir[DST], d, &vargs);
>+		//rerr = -1;
>+		d_drop(d);
>+		dput(d);
>+		if (rerr) {
>+			RevertFailure("rename %.*s", AuDLNPair(h_dst));
>+			goto out_whdst;
>+		}
>+		au_set_h_dptr(dentry, a->btgt, NULL);
>+		au_set_h_dptr(dentry, a->btgt, dget(h_dst));
>+	}
>+ out_whdst:
>+	dput(wh_dentry[DST]);
>+	wh_dentry[DST] = NULL;
>+ out_whsrc:
>+	if (wh_dentry[SRC]) {
>+		rerr = au_wh_unlink_dentry(h_dir[SRC], wh_dentry[SRC],
>+					   src_dentry, src_dir, /*dlgt*/0);
>+		//rerr = -1;
>+		if (rerr)
>+			RevertFailure("unlink %.*s", AuDLNPair(wh_dentry[SRC]));
>+	}
>+#undef RevertFailure
>+	d_drop(src_dentry);
>+	bend = au_dbend(src_dentry);
>+	for (bindex = au_dbstart(src_dentry); bindex <= bend; bindex++) {
>+		struct dentry *hd;
>+
>+		hd = au_h_dptr(src_dentry, bindex);
>+		if (hd)
>+			d_drop(hd);
>+	}
>+	d_drop(dentry);
>+	bend = au_dbend(dentry);
>+	for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) {
>+		struct dentry *hd;
>+
>+		hd = au_h_dptr(dentry, bindex);
>+		if (hd)
>+			d_drop(hd);
>+	}
>+	au_update_dbstart(dentry);
>+	if (thargs)
>+		d_drop(h_dst);
>+ out_success:
>+	dput(wh_dentry[SRC]);
>+	dput(wh_dentry[DST]);
>+ out_thargs:
>+	if (thargs) {
>+		dput(h_dst);
>+		kfree(thargs);
>+	}
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * test if @dentry dir can be rename destination or not.
>+ * success means, it is a logically empty dir.
>+ */
>+static int may_rename_dstdir(struct dentry *dentry, aufs_bindex_t btgt,
>+			     struct au_nhash *whlist)
>+{
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	return au_test_empty(dentry, whlist);
>+}
>+
>+/*
>+ * test if @dentry dir can be rename source or not.
>+ * if it can, return 0 and @children is filled.
>+ * success means,
>+ * - or, it is a logically empty dir.
>+ * - or, it exists on writable branch and has no children including whiteouts
>+ *       on the lower branch.
>+ */
>+static int may_rename_srcdir(struct dentry *dentry, aufs_bindex_t btgt)
>+{
>+	int err;
>+	aufs_bindex_t bstart;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	bstart = au_dbstart(dentry);
>+	if (bstart != btgt) {
>+		struct au_nhash *whlist;
>+
>+		whlist = au_nhash_new(GFP_TEMPORARY);
>+		err = PTR_ERR(whlist);
>+		if (IS_ERR(whlist))
>+			goto out;
>+		err = au_test_empty(dentry, whlist);
>+		au_nhash_del(whlist);
>+		goto out;
>+	}
>+
>+	if (bstart == au_dbtaildir(dentry))
>+		return 0; /* success */
>+
>+	err = au_test_empty_lower(dentry);
>+
>+ out:
>+	if (/* unlikely */(err == -ENOTEMPTY)) {
>+		AuWarn1("renaming dir who has child(ren) on multiple branches,"
>+		      " is not supported\n");
>+		err = -EXDEV;
>+	}
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* mainly for link(2) and rename(2) */
>+int au_wbr(struct dentry *dentry, aufs_bindex_t btgt)
>+{
>+	aufs_bindex_t bdiropq, bwh;
>+	struct dentry *parent;
>+
>+	LKTRTrace("%.*s, b%d\n", AuDLNPair(dentry), btgt);
>+	parent = dentry->d_parent;
>+	IMustLock(parent->d_inode); /* dir is locked */
>+
>+	bdiropq = au_dbdiropq(parent);
>+	bwh = au_dbwh(dentry);
>+	if (au_br_rdonly(au_sbr(dentry->d_sb, btgt))
>+		     || (0 <= bdiropq && bdiropq < btgt)
>+		     || (0 <= bwh && bwh < btgt))
>+		btgt = -1;
>+
>+	LKTRTrace("btgt %d\n", btgt);
>+	return btgt;
>+}
>+
>+//todo: meaningless lock if CONFIG_AUFS_DEBUG is disabled.
>+static void au_hgdirs(struct au_hinode **hgdir, struct rename_args *a)
>+{
>+	struct dentry *gparent[2];
>+	struct inode *gdir;
>+
>+	if (!au_opt_test(a->mnt_flags, UDBA_INOTIFY))
>+		return;
>+
>+	gparent[SRC] = NULL;
>+	if (!IS_ROOT(a->parent[SRC])) {
>+		gparent[SRC] = dget_parent(a->parent[SRC]);
>+		gdir = gparent[SRC]->d_inode;
>+		if (gparent[SRC] != a->parent[DST]) {
>+			ii_read_lock_parent3(gdir);
>+			hgdir[SRC] = au_hi(gdir, a->btgt);
>+			ii_read_unlock(gdir);
>+		} else
>+			hgdir[SRC] = au_hi(gdir, a->btgt);
>+		dput(gparent[SRC]);
>+	}
>+
>+	if (!au_ftest_ren(a->flags, ISSAMEDIR)
>+	    && !IS_ROOT(a->parent[DST])
>+	    && a->parent[DST] != gparent[SRC]) {
>+		gparent[DST] = dget_parent(a->parent[DST]);
>+		gdir = gparent[DST]->d_inode;
>+		if (gparent[DST] != a->parent[SRC]) {
>+			ii_read_lock_parent3(gdir);
>+			hgdir[DST] = au_hi(gdir, a->btgt);
>+			ii_read_unlock(gdir);
>+		} else
>+			hgdir[DST] = au_hi(gdir, a->btgt);
>+		dput(gparent[DST]);
>+	}
>+}
>+
>+/*
>+ * simple tests for rename.
>+ * following the checks in vfs, plus the parent-child relationship.
>+ */
>+static int au_may_ren(struct inode *src_dir, struct dentry *src_dentry,
>+		      struct inode *dir, struct dentry *dentry,
>+		      struct rename_args *a, struct au_ndx *ndx)
>+{
>+	int err;
>+	struct inode *h_inode;
>+
>+	AuTraceEnter();
>+
>+	if (a->bstart[SRC] == a->btgt) {
>+		err = au_may_del(src_dentry, a->btgt, a->h_parent[SRC],
>+				 au_ftest_ren(a->flags, ISDIR), ndx);
>+		if (unlikely(err))
>+			goto out;
>+		err = -EINVAL;
>+		if (unlikely(a->h_dentry[SRC] == a->h_trap))
>+			goto out;
>+	}
>+
>+	err = 0;
>+	if (a->bstart[DST] != a->btgt)
>+		goto out;
>+
>+	err = -EIO;
>+	h_inode = a->h_dentry[DST]->d_inode;
>+	if (!dentry->d_inode) {
>+		if (unlikely(h_inode))
>+			goto out;
>+		err = au_may_add(dentry, a->btgt, a->h_parent[DST],
>+				 au_ftest_ren(a->flags, ISDIR), ndx);
>+	} else {
>+		if (unlikely(!h_inode || !h_inode->i_nlink))
>+			goto out;
>+		err = au_may_del(dentry, a->btgt, a->h_parent[DST],
>+				 au_ftest_ren(a->flags, ISDIR), ndx);
>+		if (unlikely(err))
>+			goto out;
>+		err = -ENOTEMPTY;
>+		if (unlikely(a->h_dentry[DST] == a->h_trap))
>+			goto out;
>+		err = 0;
>+	}
>+
>+ out:
>+	if (unlikely(err == -ENOENT || err == -EEXIST))
>+		err = -EIO;
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int aufs_rename(struct inode *src_dir, struct dentry *src_dentry,
>+		struct inode *dir, struct dentry *dentry)
>+{
>+	int err, do_dt_dstdir, flags;
>+	aufs_bindex_t bend, bindex;
>+	struct inode *inode[2], *dirs[2];
>+	struct au_hinode *hgdir[2], *hdir;
>+	enum { PARENT, CHILD };
>+	/* reduce stack space */
>+	struct {
>+		struct rename_args a;
>+		struct au_dtime dt[2][2];
>+	} *p;
>+	struct au_wr_dir_args wr_dir_args = {
>+		//.force_btgt	= -1,
>+		.flags		= AuWrDir_ADD_ENTRY
>+	};
>+
>+	LKTRTrace("i%lu, %.*s, i%lu, %.*s\n",
>+		  src_dir->i_ino, AuDLNPair(src_dentry),
>+		  dir->i_ino, AuDLNPair(dentry));
>+	IMustLock(src_dir);
>+	IMustLock(dir);
>+	inode[DST] = dentry->d_inode;
>+	if (inode[DST]) {
>+		IMustLock(inode[DST]);
>+		igrab(inode[DST]);
>+	}
>+
>+	err = -ENOMEM;
>+	BUILD_BUG_ON(sizeof(*p) > PAGE_SIZE);
>+	p = kmalloc(sizeof(*p), GFP_TEMPORARY);
>+	if (unlikely(!p))
>+		goto out;
>+
>+	err = -ENOTDIR;
>+	p->a.sb = src_dentry->d_sb;
>+	inode[SRC] = src_dentry->d_inode;
>+	flags = 0;
>+	p->a.flags = 0;
>+	if (S_ISDIR(inode[SRC]->i_mode)) {
>+		flags = AuLock_DIR;
>+		au_fset_ren(p->a.flags, ISDIR);
>+		if (unlikely(inode[DST] && !S_ISDIR(inode[DST]->i_mode)))
>+			goto out_free;
>+	}
>+
>+	aufs_read_and_write_lock2(dentry, src_dentry, flags);
>+	p->a.mnt_flags = au_mntflags(p->a.sb);
>+	if (unlikely(au_opt_test_dlgt(p->a.mnt_flags)))
>+		au_fset_ren(p->a.flags, DLGT);
>+	p->a.parent[SRC] = src_dentry->d_parent; /* dir inode is locked */
>+	p->a.parent[DST] = dentry->d_parent; /* dir inode is locked */
>+	if (src_dir == dir) {
>+		au_fset_ren(p->a.flags, ISSAMEDIR);
>+		di_write_lock_parent(p->a.parent[DST]);
>+	} else
>+		di_write_lock2_parent(p->a.parent[SRC], p->a.parent[DST],
>+				      /*isdir*/1);
>+
>+	/* which branch we process */
>+	p->a.bstart[SRC] = au_dbstart(src_dentry);
>+	p->a.bstart[DST] = au_dbstart(dentry);
>+	if (au_ftest_ren(p->a.flags, ISDIR))
>+		au_fset_wrdir(wr_dir_args.flags, ISDIR);
>+	wr_dir_args.force_btgt = p->a.bstart[SRC];
>+	if (dentry->d_inode && p->a.bstart[DST] < p->a.bstart[SRC])
>+		wr_dir_args.force_btgt = p->a.bstart[DST];
>+	wr_dir_args.force_btgt = au_wbr(dentry, wr_dir_args.force_btgt);
>+	err = au_wr_dir(dentry, src_dentry, &wr_dir_args);
>+	p->a.btgt = err;
>+	if (unlikely(err < 0))
>+		goto out_unlock;
>+
>+	/* are they available to be renamed */
>+	err = 0;
>+	au_nhash_init(&p->a.whlist);
>+	if (au_ftest_ren(p->a.flags, ISDIR) && inode[DST]) {
>+		au_set_dbstart(dentry, p->a.bstart[DST]);
>+		err = may_rename_dstdir(dentry, p->a.btgt, &p->a.whlist);
>+		au_set_dbstart(dentry, p->a.btgt);
>+	}
>+	p->a.h_dentry[DST] = au_h_dptr(dentry, au_dbstart(dentry));
>+	if (unlikely(err))
>+		goto out_unlock;
>+	//todo: minor optimize, their sb may be same while their bindex differs.
>+	p->a.h_dentry[SRC] = au_h_dptr(src_dentry, au_dbstart(src_dentry));
>+	if (au_ftest_ren(p->a.flags, ISDIR)) {
>+		err = may_rename_srcdir(src_dentry, p->a.btgt);
>+		if (unlikely(err))
>+			goto out_children;
>+	}
>+
>+	/* prepare the writable parent dir on the same branch */
>+	err = au_wr_dir_need_wh(src_dentry, au_ftest_ren(p->a.flags, ISDIR),
>+				&p->a.btgt,
>+				au_ftest_ren(p->a.flags, ISSAMEDIR)
>+				? NULL : p->a.parent[DST]);
>+	if (unlikely(err < 0))
>+		goto out_children;
>+	if (err)
>+		au_fset_ren(p->a.flags, WHSRC);
>+	if (p->a.bstart[DST] == p->a.btgt) {
>+		au_fset_ren(p->a.flags, WHDST);
>+	} else {
>+		err = au_cpup_dirs(dentry, p->a.btgt,
>+				   au_ftest_ren(p->a.flags, ISSAMEDIR)
>+				   ? NULL : p->a.parent[SRC]);
>+		if (unlikely(err))
>+			goto out_children;
>+	}
>+
>+	hgdir[SRC] = NULL;
>+	hgdir[DST] = NULL;
>+	au_hgdirs(hgdir, &p->a);
>+	p->a.h_parent[SRC] = au_h_dptr(p->a.parent[SRC], p->a.btgt);
>+	p->a.h_parent[DST] = au_h_dptr(p->a.parent[DST], p->a.btgt);
>+	dirs[0] = src_dir;
>+	dirs[1] = dir;
>+
>+	AuDbgSleep_UdbaRace();
>+	p->a.h_trap = au_hdir_lock_rename(p->a.h_parent, dirs, p->a.btgt,
>+					  au_ftest_ren(p->a.flags, ISSAMEDIR));
>+	//todo: revalidate the lower dentries?
>+
>+	if (!au_opt_test(p->a.mnt_flags, UDBA_NONE)) {
>+		struct au_ndx ndx = {
>+			.nfsmnt	= au_nfsmnt(p->a.sb, p->a.btgt),
>+			.flags	= 0,
>+			.nd	= NULL,
>+			//.br	= NULL
>+		};
>+		if (unlikely(au_ftest_ren(p->a.flags, DLGT)))
>+			au_fset_ndx(ndx.flags, DLGT);
>+		err = au_may_ren(src_dir, src_dentry, dir, dentry, &p->a, &ndx);
>+		if (unlikely(err))
>+			goto out_hdir;
>+	}
>+
>+	/* store timestamps to be revertible */
>+	au_dtime_store(p->dt[PARENT] + SRC, p->a.parent[SRC],
>+		       p->a.h_parent[SRC], hgdir[SRC]);
>+	if (!au_ftest_ren(p->a.flags, ISSAMEDIR))
>+		au_dtime_store(p->dt[PARENT] + DST, p->a.parent[DST],
>+			       p->a.h_parent[DST], hgdir[DST]);
>+	do_dt_dstdir = 0;
>+	if (au_ftest_ren(p->a.flags, ISDIR)) {
>+		hdir = NULL;
>+		if (unlikely(au_opt_test(p->a.mnt_flags, UDBA_INOTIFY)))
>+			hdir = au_hi(p->a.parent[SRC]->d_inode, p->a.btgt);
>+		au_dtime_store(p->dt[CHILD] + SRC, src_dentry,
>+			       p->a.h_dentry[SRC], hdir);
>+		if (p->a.h_dentry[DST]->d_inode) {
>+			do_dt_dstdir = 1;
>+			if (unlikely(au_opt_test(p->a.mnt_flags, UDBA_INOTIFY)))
>+				hdir = au_hi(p->a.parent[DST]->d_inode,
>+					     p->a.btgt);
>+			au_dtime_store(p->dt[CHILD] + DST, dentry,
>+				       p->a.h_dentry[DST], hdir);
>+		}
>+	}
>+
>+	err = do_rename(src_dir, src_dentry, dir, dentry, &p->a);
>+	if (unlikely(err))
>+		goto out_dt;
>+	au_hdir_unlock_rename(p->a.h_parent, dirs, p->a.btgt,
>+			      au_ftest_ren(p->a.flags, ISSAMEDIR));
>+
>+	/* update dir attributes */
>+	dir->i_version++;
>+	if (au_ftest_ren(p->a.flags, ISDIR)) {
>+		/* is this updating defined in POSIX? */
>+		//mutex_lock(&inode[SRC]->i_mutex);
>+		au_cpup_attr_timesizes(inode[SRC]);
>+		//mutex_unlock(&inode[SRC]->i_mutex);
>+
>+		au_cpup_attr_nlink(dir);
>+		if (inode[DST]) {
>+			clear_nlink(inode[DST]);
>+			au_cpup_attr_timesizes(inode[DST]);
>+		}
>+	}
>+	if (au_ibstart(dir) == p->a.btgt)
>+		au_cpup_attr_timesizes(dir);
>+
>+	if (!au_ftest_ren(p->a.flags, ISSAMEDIR)) {
>+		src_dir->i_version++;
>+		if (au_ftest_ren(p->a.flags, ISDIR))
>+			au_cpup_attr_nlink(src_dir);
>+		if (au_ibstart(src_dir) == p->a.btgt)
>+			au_cpup_attr_timesizes(src_dir);
>+	}
>+
>+	/* dput/iput all lower dentries */
>+	au_set_dbwh(src_dentry, -1);
>+	bend = au_dbend(src_dentry);
>+	for (bindex = p->a.btgt + 1; bindex <= bend; bindex++) {
>+		struct dentry *hd;
>+		hd = au_h_dptr(src_dentry, bindex);
>+		if (hd)
>+			au_set_h_dptr(src_dentry, bindex, NULL);
>+	}
>+	au_set_dbend(src_dentry, p->a.btgt);
>+
>+	bend = au_ibend(inode[SRC]);
>+	for (bindex = p->a.btgt + 1; bindex <= bend; bindex++) {
>+		struct inode *hi;
>+		hi = au_h_iptr(inode[SRC], bindex);
>+		if (hi) {
>+			//AuDbg("hi%lu, i%lu\n", hi->i_ino, 0LU);
>+			au_xino_write0(p->a.sb, bindex, hi->i_ino, 0);
>+			/* ignore this error */
>+			au_set_h_iptr(inode[SRC], bindex, NULL, 0);
>+		}
>+	}
>+	au_set_ibend(inode[SRC], p->a.btgt);
>+
>+	goto out_children; /* success */
>+
>+ out_dt:
>+	au_dtime_revert(p->dt[PARENT] + SRC);
>+	if (!au_ftest_ren(p->a.flags, ISSAMEDIR))
>+		au_dtime_revert(p->dt[PARENT] + DST);
>+	if (au_ftest_ren(p->a.flags, ISDIR) && err != -EIO) {
>+		struct dentry *hd;
>+
>+		hd = p->dt[CHILD][SRC].dt_h_dentry;
>+		mutex_lock_nested(&hd->d_inode->i_mutex, AuLsc_I_CHILD);
>+		au_dtime_revert(p->dt[CHILD] + SRC);
>+		mutex_unlock(&hd->d_inode->i_mutex);
>+		if (do_dt_dstdir) {
>+			hd = p->dt[CHILD][DST].dt_h_dentry;
>+			mutex_lock_nested(&hd->d_inode->i_mutex, AuLsc_I_CHILD);
>+			au_dtime_revert(p->dt[CHILD] + DST);
>+			mutex_unlock(&hd->d_inode->i_mutex);
>+		}
>+	}
>+ out_hdir:
>+	au_hdir_unlock_rename(p->a.h_parent, dirs, p->a.btgt,
>+			      au_ftest_ren(p->a.flags, ISSAMEDIR));
>+ out_children:
>+	au_nhash_fin(&p->a.whlist);
>+ out_unlock:
>+	//if (unlikely(err /* && au_ftest_ren(p->a.flags, ISDIR) */)) {
>+	if (unlikely(err && au_ftest_ren(p->a.flags, ISDIR))) {
>+		au_update_dbstart(dentry);
>+		d_drop(dentry);
>+	}
>+	if (au_ftest_ren(p->a.flags, ISSAMEDIR))
>+		di_write_unlock(p->a.parent[DST]);
>+	else
>+		di_write_unlock2(p->a.parent[SRC], p->a.parent[DST]);
>+	aufs_read_and_write_unlock2(dentry, src_dentry);
>+ out_free:
>+	kfree(p);
>+ out:
>+	iput(inode[DST]);
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/Kconfig linux-2.6.25.4-unionfs/fs/aufs/Kconfig
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/Kconfig	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/Kconfig	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,284 @@
>+config AUFS
>+	tristate "Another unionfs"
>+	help
>+	Aufs is a stackable unification filesystem such as Unionfs,
>+	which unifies several directories and provides a merged single
>+	directory.
>+	In the early days, aufs was entirely re-designed and
>+	re-implemented Unionfs Version 1.x series. After many original
>+	ideas, approaches and improvements, it becomes totally
>+	different from Unionfs while keeping the basic features.
>+	See Unionfs for the basic features.
>+
>+if AUFS
>+
>+config AUFS_FAKE_DM
>+	bool "Use simplified (fake) nameidata"
>+	depends on AUFS
>+	default y
>+	help
>+	Faking nameidata (linux kernel internal data), you can get
>+	better performance in some cases.
>+	When you use NFS as an aufs branch or dlgt /* /dirperm1 */ aufs mount option,
>+	you need to disable this configuration.
>+
>+choice
>+	prompt "Maximum number of branches"
>+	depends on AUFS
>+	default AUFS_BRANCH_MAX_127
>+	help
>+	Specifies the maximum number of branches (or member directories) in a \
>+	single aufs. The larger value consumes more system resources and has \
>+	an impact to performance.
>+config AUFS_BRANCH_MAX_127
>+	bool "127"
>+	help
>+	Specifies the maximum number of branches (or member directories) in a \
>+	single aufs. The larger value consumes more system resources and has \
>+	an impact to performance.
>+config AUFS_BRANCH_MAX_511
>+	bool "511"
>+	help
>+	Specifies the maximum number of branches (or member directories) in a \
>+	single aufs. The larger value consumes more system resources and has \
>+	an impact to performance.
>+config AUFS_BRANCH_MAX_1023
>+	bool "1023"
>+	help
>+	Specifies the maximum number of branches (or member directories) in a \
>+	single aufs. The larger value consumes more system resources and has \
>+	an impact to performance.
>+config AUFS_BRANCH_MAX_32767
>+	bool "32767"
>+	help
>+	Specifies the maximum number of branches (or member directories) in a \
>+	single aufs. The larger value consumes more system resources and has \
>+	an impact to performance.
>+endchoice
>+
>+config AUFS_HINOTIFY
>+	bool "Use inotify to detect actions on a branch"
>+	depends on AUFS
>+	depends on INOTIFY
>+	default n
>+	help
>+	If you want to modify files on branches directly, eg. bypassing aufs,
>+	and want aufs to detect the changes of them fully, then enable this
>+	option and use 'udba=inotify' mount option.
>+	It will damage the performance.
>+	See detail in aufs.5.
>+
>+comment "INOTIFY and AUFS_HINOTIFY are disabled"
>+	depends on INOTIFY = n
>+
>+config AUFS_EXPORT
>+	bool "NFS-exportable aufs"
>+	depends on AUFS
>+	depends on (AUFS = y && EXPORTFS = y) || (AUFS = m && EXPORTFS)
>+	default n
>+	help
>+	If you want to export your mounted aufs, then enable this
>+	option. There are several requirements to export aufs.
>+	See detail in aufs.5.
>+
>+comment "EXPORTFS and AUFS_EXPORT are disabled"
>+	depends on AUFS
>+	depends on EXPORTFS = n
>+
>+comment "AUFS_EXPORT is disabled since EXPORTFS is a module but AUFS"
>+	depends on AUFS
>+	depends on EXPORTFS = m && AUFS = y
>+
>+config AUFS_ROBR
>+	bool "Aufs as an readonly branch of another aufs"
>+	depends on AUFS
>+	default n
>+	help
>+	If you want make your aufs to be a part of another aufs, then
>+	enable this option. In other words, you can specify your aufs
>+	path in 'br:' mount option for another aufs, but cannot
>+	specify 'rw' as the branch permission.
>+	It will damage the performance.
>+	See detail in aufs.5.
>+
>+config AUFS_DLGT
>+	bool "Delegate the internal branch access the kernel thread"
>+	depends on AUFS
>+	default n
>+	help
>+	If you want /*to use 'dirperm1' mount option, or */ aufs to delegate
>+	the internal access to the branches which is made by aufs, to
>+	the kernel thread, in order to hide the access issued by your
>+	application from your LSM or something or make your
>+	application to be traced strictly by the task I/O accounting,
>+	then enable this option and use 'dlgt' mount option.
>+	It will damage the performance.
>+	See detail in aufs.5.
>+
>+config AUFS_RR_SQUASHFS
>+	bool "Make squashfs branch RR (real readonly) by default"
>+	depends on AUFS
>+	default y
>+	help
>+	If you use squashfs or LZMA patched squashfs as an aufs branch
>+	and want to set '=rr' to it by default, then enable this
>+	configuration.
>+	'rr' stands for real readonly and it optimizes some aspects of
>+	'ro.'
>+	See detail in aufs.5.
>+
>+config AUFS_SEC_PERM_PATCH
>+	bool "sec_perm-2.6.24.patch was applied or not"
>+	depends on AUFS
>+	depends on AUFS = m
>+	depends on SECURITY
>+	default n
>+	help
>+	If you build aufs as a module and enabled CONFIG_SECURITY,
>+	then you need to apply the patch
>+	'CVS_TREE/aufs/patch/sec_perm-2.6.24.patch' to your kernel
>+	source, and enable this configuration.
>+	The sec_perm-2.6.24.patch exports a kernel function
>+	security_inode_permission() to modules.
>+
>+comment "SECURITY and AUFS_SEC_PERM_PATCH are disabled"
>+	depends on AUFS
>+	depends on SECURITY = n
>+
>+config AUFS_SPLICE_PATCH
>+	bool "splice.patch for sendfile(2) and splice(2)"
>+	depends on AUFS
>+	default n
>+	help
>+	If you use 'loopback mount' on a fs-image file, or use
>+	splice(2) or sendfile(2) systemcall in aufs, then you need to
>+	apply the patch 'CVS_TREE/aufs/patch/splice.patch' to your
>+	kernel source, and enable this configuration.
>+	The splice.patch makes the kernel function vfs_splice_to/from()
>+	global and exports them to modules.
>+
>+config AUFS_PUT_FILP_PATCH
>+	bool "put_filp.patch for NFS branch"
>+	depends on AUFS
>+	depends on AUFS = m
>+	depends on NFS_FS
>+	depends on AUFS_FAKE_DM = n
>+	default n
>+	help
>+	If you build aufs as a module and use mounted NFS as an aufs
>+	branch filesystem, then you need to apply the patch
>+	'CVS_TREE/aufs/patch/put_filp.patch' to your kernel source,
>+	and enable this configuration.
>+	The put_filp.patch exports a kernel function put_filp() to
>+	modules.
>+
>+comment "NFS_FS and AUFS_PUT_FILP_PATCH are disabled"
>+	depends on AUFS
>+	depends on NFS_FS = n
>+
>+comment "AUFS_FILP_PATCH is disabled since AUFS_FAKE_DM is enabled"
>+	depends on AUFS
>+	depends on AUFS_FAKE_DM
>+
>+config AUFS_LHASH_PATCH
>+	bool "lhash.patch for NFS branch"
>+	depends on AUFS
>+	depends on NFS_FS
>+	depends on AUFS_FAKE_DM = n
>+	default n
>+	help
>+	If you use mounted NFS as an aufs branch filesystem, then you
>+	need to apply the patch 'CVS_TREE/aufs/patch/lhash.patch' (or
>+	lhash-2.6.22.patch for linux-2.6.22 and later) to your kernel
>+	source, and enable this configuration.
>+	The patch file makes the kernel function __lookup_hash() global
>+	and exports it to modules.
>+
>+comment "NFS_FS and AUFS_LHASH_PATCH are disabled"
>+	depends on AUFS
>+	depends on NFS_FS = n
>+
>+comment "AUFS_LHASH_PATCH is disabled since AUFS_FAKE_DM is enabled"
>+	depends on AUFS
>+	depends on AUFS_FAKE_DM
>+
>+config AUFS_FSYNC_SUPER_PATCH
>+	bool "fsync_super-2.6.xx.patch was applied or not"
>+	depends on AUFS
>+	depends on AUFS = m
>+	default n
>+	help
>+	If you build aufs as a module and want to flush everything for
>+	branch filesystems which are not marked as 'rr' nor 'rr+wh' at
>+	umount or remount time, then you need to apply the patch
>+	'CVS_TREE/aufs/patch/fsync_super-2.6.16.patch' or
>+	'...-2.6.19.patch' to your kernel source, and enable this
>+	configuration.
>+	It may be helpful at shutdown time in case of your aufs is a
>+	root filesystem. But this behaviour will not guarantee the
>+	consistency of branch filesystems. To gurantee it, try the
>+	approach described in the aufs manual, and don't forget
>+	installing auplink script.
>+	The fsync_super-2.6.xx.patch does nothing but exports a kernel
>+	function fsync_super() to modules.
>+
>+config AUFS_DENY_WRITE_ACCESS_PATCH
>+	bool "deny_write_access.patch was applied or not"
>+	depends on AUFS
>+	depends on AUFS = m
>+	default n
>+	help
>+	A security enhancement to deny writing to a running executable
>+	which exists on an aufs branch filesystem and executed through
>+	aufs. If you applied
>+	'CVS_TREE/aufs/patch/deny_write_access.patch' to your kernel
>+	and you are compiling aufs as a module, then enable this
>+	option.
>+	The write_deny_access.patch does nothing but export the
>+	function.
>+
>+config AUFS_WORKAROUND_FUSE
>+	bool "Special handling for FUSE-based filesystem"
>+	depends on AUFS && FUSE_FS
>+	default n
>+	help
>+	A FUSE-based filesystem may not initialize its inode
>+	attributes and the FUSE developer thinks the inode attributes
>+	in a positive dentry which is returned by VFS lookup operation
>+	are not reliable.
>+	If you use a FUSE-based filesystem as an aufs branch, and it
>+	customizes the inode attribute on it without overriding
>+	fuse_lowlevel_ops.lookup, probably you need to enable this
>+	configuration.
>+	If you enable this configuration, aufs calls getattr operation
>+	in every lookup and revalidate operation for the FUSE-based
>+	filesystem branch.
>+	It will damage the performance even if you don't use a
>+	FUSE-based filesystem branch.
>+
>+config AUFS_DEBUG
>+	bool "Debug aufs"
>+	depends on AUFS
>+	default y
>+	help
>+	Enable this to compile aufs internal debug code.
>+	The performance will be damaged.
>+
>+config AUFS_COMPAT
>+	bool "Compatibility with Unionfs (obsolete)"
>+	depends on AUFS
>+	default n
>+	help
>+	This makes aufs compatible with unionfs-style mount options and some
>+	behaviours.
>+	The dirs= mount option and =nfsro branch permission flag are always
>+	interpreted as br: mount option and =ro flag respectively. The
>+	'debug', 'delete' and 'imap' mount options are ignored.
>+	If you disable this option, you will get,
>+	- aufs issues a warning about the ignored mount options
>+	- the default branch permission flag is set. RW for the first branch,
>+	  and RO for the rests.
>+	- the name of a internal file which represents the directory is
>+	  'opaque', becomes '.wh..wh..opq'
>+	- the 'diropq=w' mount option is set by default
>+endif
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/Makefile linux-2.6.25.4-unionfs/fs/aufs/Makefile
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/Makefile	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/Makefile	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,65 @@
>+# AUFS Makefile for the Linux 2.6.25 and later
>+# $Id: Makefile,v 1.3 2008/04/28 03:03:10 sfjro Exp $
>+
>+# the environment variables are not inherited since 2.6.23
>+ifdef AUFS_EXTRA_CFLAGS
>+EXTRA_CFLAGS += ${AUFS_EXTRA_CFLAGS}
>+endif
>+
>+########################################
>+
>+ifdef CONFIG_AUFS_RR_SQUASHFS
>+# cf. squashfs3.2-r2 and sqlzma patch.
>+EXTRA_CFLAGS += -DSQUASHFS_MAGIC=0x73717368
>+EXTRA_CFLAGS += -DSQUASHFS_MAGIC_SWAP=0x68737173
>+EXTRA_CFLAGS += -DSQUASHFS_MAGIC_LZMA=0x71736873
>+EXTRA_CFLAGS += -DSQUASHFS_MAGIC_LZMA_SWAP=0x73687371
>+endif
>+
>+ifdef CONFIG_AUFS_WORKAROUND_FUSE
>+# defined in ${srctree}/fs/fuse/inode.c
>+EXTRA_CFLAGS += -DFUSE_SUPER_MAGIC=0x65735546
>+endif
>+
>+ifdef CONFIG_XFS_FS
>+# defined in ${srctree}/fs/xfs/xfs_sb.h
>+EXTRA_CFLAGS += -DXFS_SB_MAGIC=0x58465342
>+endif
>+
>+ifdef CONFIG_TMPFS
>+# defined in ${srctree}/mm/shmem.c
>+EXTRA_CFLAGS += -DTMPFS_MAGIC=0x01021994
>+endif
>+
>+-include $(dir $(lastword ${MAKEFILE_LIST}))priv.mk
>+#$(warning ${EXTRA_CFLAGS})
>+
>+########################################
>+
>+obj-$(CONFIG_AUFS) += aufs.o
>+aufs-y := module.o super.o sbinfo.o branch.o xino.o sysaufs.o opts.o \
>+	wkq.o vfsub.o dcsub.o \
>+	cpup.o whout.o plink.o wbr_policy.o \
>+	dentry.o dinfo.o \
>+	file.o f_op.o finfo.o \
>+	dir.o vdir.o \
>+	inode.o i_op.o i_op_add.o i_op_del.o i_op_ren.o iinfo.o \
>+	misc.o
>+
>+#xattr.o
>+aufs-$(CONFIG_SYSFS) += sysfs.o
>+aufs-$(CONFIG_AUFS_BR_NFS) += br_nfs.o
>+aufs-$(CONFIG_AUFS_BR_XFS) += br_xfs.o
>+aufs-$(CONFIG_AUFS_WORKAROUND_FUSE) += br_fuse.o
>+
>+aufs-$(CONFIG_AUFS_DLGT) += dlgt.o
>+aufs-$(CONFIG_AUFS_HINOTIFY) += hinotify.o hin_or_dlgt.o
>+# dirty
>+ifndef CONFIG_AUFS_HINOTIFY
>+aufs-$(CONFIG_AUFS_DLGT) += hin_or_dlgt.o
>+endif
>+
>+aufs-$(CONFIG_AUFS_EXPORT) += export.o
>+aufs-$(CONFIG_AUFS_ROBR) += robr.o
>+aufs-$(CONFIG_AUFS_DEBUG) += debug.o
>+aufs-$(CONFIG_AUFS_MAGIC_SYSRQ) += sysrq.o
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/misc.c linux-2.6.25.4-unionfs/fs/aufs/misc.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/misc.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/misc.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,271 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * $Id: misc.c,v 1.6 2008/05/19 01:46:53 sfjro Exp $
>+ */
>+
>+//#include <linux/fs.h>
>+//#include <linux/namei.h>
>+//#include <linux/mm.h>
>+//#include <asm/uaccess.h>
>+#include "aufs.h"
>+
>+void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp)
>+{
>+	void *q;
>+
>+	LKTRTrace("p %p, nused %d, sz %d\n", p, nused, new_sz);
>+	AuDebugOn(new_sz <= 0);
>+	if (new_sz <= nused)
>+		return p;
>+
>+	q = krealloc(p, new_sz, gfp);
>+	if (q)
>+		memset(q + nused, 0, new_sz - nused);
>+	return q;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct nameidata *au_dup_nd(struct au_sbinfo *sbinfo, struct nameidata *dst,
>+			    struct nameidata *src)
>+{
>+	LKTRTrace("src %p\n", src);
>+
>+	if (src) {
>+		*dst = *src;
>+		dst->flags &= ~LOOKUP_PARENT;
>+		if (sbinfo->si_wbr_create == AuWbrCreate_TDP) {
>+			if ((dst->flags & LOOKUP_CREATE)
>+			    && !(dst->intent.open.flags & O_CREAT))
>+				dst->flags &= ~LOOKUP_CREATE;
>+		} else {
>+			dst->flags &= ~LOOKUP_CREATE;
>+			dst->intent.open.flags &= ~O_CREAT;
>+		}
>+	} else
>+		dst = NULL;
>+
>+	return dst;
>+}
>+
>+struct nameidata *au_fake_dm(struct nameidata *fake_nd, struct nameidata *nd,
>+			     struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	LKTRTrace("nd %p, b%d\n", nd, bindex);
>+
>+	if (!nd)
>+		return NULL;
>+
>+	DiMustAnyLock(nd->path.dentry);
>+
>+	fake_nd->path.dentry = NULL;
>+	fake_nd->path.mnt = NULL;
>+
>+	if (bindex <= au_dbend(nd->path.dentry))
>+		fake_nd->path.dentry = au_h_dptr(nd->path.dentry, bindex);
>+	if (fake_nd->path.dentry) {
>+		fake_nd->path.mnt = au_sbr_mnt(sb, bindex);
>+		AuDebugOn(!fake_nd->path.mnt);
>+		path_get(&fake_nd->path);
>+	} else
>+		fake_nd = ERR_PTR(-ENOENT);
>+
>+	AuTraceErrPtr(fake_nd);
>+	return fake_nd;
>+}
>+
>+void au_fake_dm_release(struct nameidata *fake_nd)
>+{
>+	if (fake_nd)
>+		path_put(&fake_nd->path);
>+}
>+
>+int au_h_create(struct inode *h_dir, struct dentry *h_dentry, int mode,
>+		int dlgt, struct nameidata *nd, struct vfsmount *nfsmnt)
>+{
>+	int err;
>+
>+	LKTRTrace("hi%lu, %.*s, 0%o, nd %d, nfsmnt %d\n",
>+		  h_dir->i_ino, AuDLNPair(h_dentry), mode, !!nd, !!nfsmnt);
>+
>+	err = -ENOSYS;
>+	if (!nfsmnt)
>+		err = vfsub_create(h_dir, h_dentry, mode, /*nd*/NULL, dlgt);
>+	else {
>+		struct nameidata fake_nd;
>+
>+		if (nd)
>+			fake_nd = *nd;
>+		else
>+			memset(&fake_nd, 0, sizeof(fake_nd));
>+		fake_nd.path.dentry = h_dentry;
>+		fake_nd.path.mnt = nfsmnt;
>+		path_get(&fake_nd.path);
>+		fake_nd.flags = LOOKUP_CREATE;
>+		fake_nd.intent.open.flags = O_CREAT | FMODE_READ;
>+		fake_nd.intent.open.create_mode = mode;
>+
>+		err = vfsub_create(h_dir, h_dentry, mode, &fake_nd, dlgt);
>+		path_put(&fake_nd.path);
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int au_copy_file(struct file *dst, struct file *src, loff_t len,
>+		 struct super_block *sb)
>+{
>+	int err, all_zero;
>+	unsigned long blksize;
>+	char *buf;
>+	struct vfsub_args vargs;
>+	/* reduce stack space */
>+	struct iattr *ia;
>+
>+	LKTRTrace("%.*s, %.*s\n",
>+		  AuDLNPair(dst->f_dentry), AuDLNPair(src->f_dentry));
>+	AuDebugOn(!(dst->f_mode & FMODE_WRITE));
>+#ifdef CONFIG_AUFS_DEBUG
>+	{
>+		struct dentry *parent;
>+		parent = dget_parent(dst->f_dentry);
>+		IMustLock(parent->d_inode);
>+		dput(parent);
>+	}
>+#endif
>+
>+	err = -ENOMEM;
>+	blksize = dst->f_dentry->d_sb->s_blocksize;
>+	if (!blksize || PAGE_SIZE < blksize)
>+		blksize = PAGE_SIZE;
>+	LKTRTrace("blksize %lu\n", blksize);
>+	buf = kmalloc(blksize, GFP_TEMPORARY);
>+	//buf = NULL;
>+	if (unlikely(!buf))
>+		goto out;
>+	ia = kmalloc(sizeof(*ia), GFP_TEMPORARY);
>+	if (unlikely(!ia))
>+		goto out_buf;
>+
>+#ifdef CONFIG_AUFS_DEBUG
>+	if (len > (1 << 22))
>+		AuWarn("copying a large file %Ld\n", (long long)len);
>+#endif
>+	vfsub_args_init(&vargs, NULL, au_opt_test_dlgt(au_mntflags(sb)), 0);
>+	err = 0;
>+	all_zero = 0;
>+	src->f_pos = 0;
>+	dst->f_pos = 0;
>+	while (len) {
>+		size_t sz, rbytes, wbytes, i;
>+		char *p;
>+
>+		LKTRTrace("len %lld\n", len);
>+		sz = blksize;
>+		if (len < blksize)
>+			sz = len;
>+
>+		/* support LSM and notify */
>+		rbytes = 0;
>+		// signal_pending
>+		while (!rbytes || err == -EAGAIN || err == -EINTR) {
>+			rbytes = vfsub_read_k(src, buf, sz, &src->f_pos,
>+					      vfsub_ftest(vargs.flags, DLGT));
>+			err = rbytes;
>+		}
>+		if (unlikely(err < 0))
>+			break;
>+
>+		all_zero = 0;
>+		if (len >= rbytes && rbytes == blksize) {
>+			//todo: try bitmap or memcmp()/get_zeroed_page()
>+			unsigned long *ulp;
>+			size_t n;
>+
>+			all_zero = 1;
>+			ulp = (void *)buf;
>+			n = rbytes / sizeof(*ulp);
>+			i = n;
>+			while (n-- > 0 && all_zero)
>+				all_zero = !*ulp++;
>+			p = (void *)ulp;
>+			i *= sizeof(*ulp);
>+			for (; all_zero && i < rbytes; i++)
>+				all_zero = !*p++;
>+		}
>+		if (!all_zero) {
>+			wbytes = rbytes;
>+			p = buf;
>+			while (wbytes) {
>+				size_t b;
>+				/* support LSM and notify */
>+				b = vfsub_write_k(dst, p, wbytes, &dst->f_pos,
>+						  &vargs);
>+				err = b;
>+				// signal_pending
>+				if (unlikely(err == -EAGAIN || err == -EINTR))
>+					continue;
>+				if (unlikely(err < 0))
>+					break;
>+				wbytes -= b;
>+				p += b;
>+			}
>+		} else {
>+			loff_t res;
>+			LKTRLabel(hole);
>+			res = vfsub_llseek(dst, rbytes, SEEK_CUR);
>+			err = res;
>+			if (unlikely(res < 0))
>+				break;
>+		}
>+		len -= rbytes;
>+		err = 0;
>+	}
>+
>+	/* the last block may be a hole */
>+	if (unlikely(!err && all_zero)) {
>+		struct dentry *h_d = dst->f_dentry;
>+		struct inode *h_i = h_d->d_inode;
>+
>+		LKTRLabel(last hole);
>+		do {
>+			// signal_pending
>+			err = vfsub_write_k(dst, "\0", 1, &dst->f_pos, &vargs);
>+		} while (err == -EAGAIN || err == -EINTR);
>+		if (err == 1) {
>+			ia->ia_size = dst->f_pos;
>+			ia->ia_valid = ATTR_SIZE | ATTR_FILE;
>+			ia->ia_file = dst;
>+			mutex_lock_nested(&h_i->i_mutex, AuLsc_I_CHILD2);
>+			err = vfsub_notify_change(h_d, ia, &vargs);
>+			mutex_unlock(&h_i->i_mutex);
>+		}
>+	}
>+
>+	kfree(ia);
>+ out_buf:
>+	kfree(buf);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/misc.h linux-2.6.25.4-unionfs/fs/aufs/misc.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/misc.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/misc.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,201 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * $Id: misc.h,v 1.2 2008/04/21 01:33:00 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_MISC_H__
>+#define __AUFS_MISC_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/namei.h>
>+#include <linux/aufs_type.h>
>+
>+/* ---------------------------------------------------------------------- */
>+
>+typedef unsigned int au_gen_t;
>+/* see linux/include/linux/jiffies.h */
>+#define AuGenYounger(a, b)	((int)(b) - (int)(a) < 0)
>+#define AuGenOlder(a, b)	AufsGenYounger(b, a)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_rwsem {
>+	struct rw_semaphore	rwsem;
>+#ifdef CONFIG_AUFS_DEBUG
>+	atomic_t		rcnt;
>+#endif
>+};
>+
>+#ifdef CONFIG_AUFS_DEBUG
>+#define AuDbgRcntInit(rw) do { \
>+	atomic_set(&(rw)->rcnt, 0); \
>+	smp_mb(); \
>+} while (0)
>+
>+#define AuDbgRcntInc(rw)	atomic_inc_return(&(rw)->rcnt)
>+#define AuDbgRcntDec(rw)	WARN_ON(atomic_dec_return(&(rw)->rcnt) < 0)
>+#else
>+#define AuDbgRcntInit(rw)	do {} while (0)
>+#define AuDbgRcntInc(rw)	do {} while (0)
>+#define AuDbgRcntDec(rw)	do {} while (0)
>+#endif /* CONFIG_AUFS_DEBUG */
>+
>+static inline void au_rw_init_nolock(struct au_rwsem *rw)
>+{
>+	AuDbgRcntInit(rw);
>+	init_rwsem(&rw->rwsem);
>+}
>+
>+static inline void au_rw_init_wlock(struct au_rwsem *rw)
>+{
>+	au_rw_init_nolock(rw);
>+	down_write(&rw->rwsem);
>+}
>+
>+static inline void au_rw_init_wlock_nested(struct au_rwsem *rw,
>+					   unsigned int lsc)
>+{
>+	au_rw_init_nolock(rw);
>+	down_write_nested(&rw->rwsem, lsc);
>+}
>+
>+static inline void au_rw_read_lock(struct au_rwsem *rw)
>+{
>+	down_read(&rw->rwsem);
>+	AuDbgRcntInc(rw);
>+}
>+
>+static inline void au_rw_read_lock_nested(struct au_rwsem *rw, unsigned int lsc)
>+{
>+	down_read_nested(&rw->rwsem, lsc);
>+	AuDbgRcntInc(rw);
>+}
>+
>+static inline void au_rw_read_unlock(struct au_rwsem *rw)
>+{
>+	AuDbgRcntDec(rw);
>+	up_read(&rw->rwsem);
>+}
>+
>+static inline void au_rw_dgrade_lock(struct au_rwsem *rw)
>+{
>+	AuDbgRcntInc(rw);
>+	downgrade_write(&rw->rwsem);
>+}
>+
>+static inline void au_rw_write_lock(struct au_rwsem *rw)
>+{
>+	down_write(&rw->rwsem);
>+}
>+
>+static inline void au_rw_write_lock_nested(struct au_rwsem *rw,
>+					   unsigned int lsc)
>+{
>+	down_write_nested(&rw->rwsem, lsc);
>+}
>+
>+static inline void au_rw_write_unlock(struct au_rwsem *rw)
>+{
>+	up_write(&rw->rwsem);
>+}
>+
>+/* why is not _nested version defined */
>+static inline int au_rw_read_trylock(struct au_rwsem *rw)
>+{
>+	int ret = down_read_trylock(&rw->rwsem);
>+	if (ret)
>+		AuDbgRcntInc(rw);
>+	return ret;
>+}
>+
>+static inline int au_rw_write_trylock(struct au_rwsem *rw)
>+{
>+	return down_write_trylock(&rw->rwsem);
>+}
>+
>+#undef AuDbgRcntInit
>+#undef AuDbgRcntInc
>+#undef AuDbgRcntDec
>+
>+/* to debug easier, do not make them inlined functions */
>+#define AuRwMustNoWaiters(rw)	AuDebugOn(!list_empty(&(rw)->rwsem.wait_list))
>+#define AuRwMustAnyLock(rw)	AuDebugOn(down_write_trylock(&(rw)->rwsem))
>+#ifdef CONFIG_AUFS_DEBUG
>+#define AuRwMustReadLock(rw) do { \
>+	AuRwMustAnyLock(rw); \
>+	AuDebugOn(!atomic_read(&(rw)->rcnt)); \
>+} while (0)
>+
>+#define AuRwMustWriteLock(rw) do { \
>+	AuRwMustAnyLock(rw); \
>+	AuDebugOn(atomic_read(&(rw)->rcnt)); \
>+} while (0)
>+#else
>+#define AuRwMustReadLock(rw)	AuRwMustAnyLock(rw)
>+#define AuRwMustWriteLock(rw)	AuRwMustAnyLock(rw)
>+#endif /* CONFIG_AUFS_DEBUG */
>+
>+#define AuSimpleLockRwsemFuncs(prefix, param, rwsem) \
>+static inline void prefix##_read_lock(param) \
>+{ au_rw_read_lock(&(rwsem)); } \
>+static inline void prefix##_write_lock(param) \
>+{ au_rw_write_lock(&(rwsem)); } \
>+static inline int prefix##_read_trylock(param) \
>+{ return au_rw_read_trylock(&(rwsem)); } \
>+static inline int prefix##_write_trylock(param) \
>+{ return au_rw_write_trylock(&(rwsem)); }
>+//static inline void prefix##_read_trylock_nested(param, lsc)
>+//{au_rw_read_trylock_nested(&(rwsem, lsc));}
>+//static inline void prefix##_write_trylock_nestd(param, lsc)
>+//{au_rw_write_trylock_nested(&(rwsem), nested);}
>+
>+#define AuSimpleUnlockRwsemFuncs(prefix, param, rwsem) \
>+static inline void prefix##_read_unlock(param) \
>+{ au_rw_read_unlock(&(rwsem)); } \
>+static inline void prefix##_write_unlock(param) \
>+{ au_rw_write_unlock(&(rwsem)); } \
>+static inline void prefix##_downgrade_lock(param) \
>+{ au_rw_dgrade_lock(&(rwsem)); }
>+
>+#define AuSimpleRwsemFuncs(prefix, param, rwsem) \
>+	AuSimpleLockRwsemFuncs(prefix, param, rwsem) \
>+	AuSimpleUnlockRwsemFuncs(prefix, param, rwsem)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp);
>+
>+struct au_sbinfo;
>+struct nameidata *au_dup_nd(struct au_sbinfo *sbinfo, struct nameidata *dst,
>+			    struct nameidata *src);
>+
>+struct nameidata *au_fake_dm(struct nameidata *fake_nd, struct nameidata *nd,
>+			     struct super_block *sb, aufs_bindex_t bindex);
>+void au_fake_dm_release(struct nameidata *fake_nd);
>+int au_h_create(struct inode *h_dir, struct dentry *h_dentry, int mode,
>+		int dlgt, struct nameidata *nd, struct vfsmount *nfsmnt);
>+
>+int au_copy_file(struct file *dst, struct file *src, loff_t len,
>+		 struct super_block *sb);
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_MISC_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/module.c linux-2.6.25.4-unionfs/fs/aufs/module.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/module.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/module.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,237 @@
>+/*
>+ * Copyright (C) 2007 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * module global variables and operations
>+ *
>+ * $Id: module.c,v 1.4 2008/05/19 01:49:24 sfjro Exp $
>+ */
>+
>+#include <linux/module.h>
>+#include "aufs.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * aufs caches
>+ */
>+struct kmem_cache *au_cachep[AuCache_Last];
>+static int __init create_cache(void)
>+{
>+	au_cachep[AuCache_DINFO] = AuCache(au_dinfo);
>+	if (au_cachep[AuCache_DINFO])
>+		au_cachep[AuCache_ICNTNR] = AuCache(aufs_icntnr);
>+	if (au_cachep[AuCache_ICNTNR])
>+		au_cachep[AuCache_FINFO] = AuCache(au_finfo);
>+	//au_cachep[AuCache_FINFO] = NULL;
>+	if (au_cachep[AuCache_FINFO])
>+		au_cachep[AuCache_VDIR] = AuCache(au_vdir);
>+	if (au_cachep[AuCache_VDIR])
>+		au_cachep[AuCache_DEHSTR] = AuCache(au_vdir_dehstr);
>+	if (au_cachep[AuCache_DEHSTR])
>+		return 0;
>+
>+	return -ENOMEM;
>+}
>+
>+static void destroy_cache(void)
>+{
>+	int i;
>+	for (i = 0; i < AuCache_Last; i++)
>+		if (au_cachep[i]) {
>+			kmem_cache_destroy(au_cachep[i]);
>+			au_cachep[i] = NULL;
>+		}
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+char au_esc_chars[0x20 + 3]; /* 0x01-0x20, backslash, del, and NULL */
>+int au_dir_roflags;
>+
>+/*
>+ * functions for module interface.
>+ */
>+MODULE_LICENSE("GPL");
>+MODULE_AUTHOR("Junjiro Okajima");
>+MODULE_DESCRIPTION(AUFS_NAME " -- Another unionfs");
>+MODULE_VERSION(AUFS_VERSION);
>+
>+/* it should be 'byte', but param_set_byte() prints it by "%c" */
>+short aufs_nwkq = AUFS_NWKQ_DEF;
>+MODULE_PARM_DESC(nwkq, "the number of workqueue thread, " AUFS_WKQ_NAME);
>+module_param_named(nwkq, aufs_nwkq, short, S_IRUGO);
>+
>+int sysaufs_brs;
>+MODULE_PARM_DESC(brs, "use <sysfs>/fs/aufs/si_*/brN");
>+module_param_named(brs, sysaufs_brs, int, S_IRUGO);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int __init aufs_init(void)
>+{
>+	int err, i;
>+	char *p;
>+
>+	au_debug_init();
>+
>+	p = au_esc_chars;
>+	for (i = 1; i <= ' '; i++)
>+		*p++ = i;
>+	*p++ = '\\';
>+	*p++ = '\x7f';
>+	*p = 0;
>+
>+	au_dir_roflags = au_file_roflags(O_DIRECTORY | O_LARGEFILE);
>+
>+	err = -EINVAL;
>+	if (unlikely(aufs_nwkq <= 0))
>+		goto out;
>+
>+	err = sysaufs_init();
>+	if (unlikely(err))
>+		goto out;
>+	err = au_wkq_init();
>+	if (unlikely(err))
>+		goto out_sysaufs;
>+	err = au_inotify_init();
>+	if (unlikely(err))
>+		goto out_wkq;
>+	err = au_sysrq_init();
>+	if (unlikely(err))
>+		goto out_inotify;
>+
>+	err = create_cache();
>+	if (unlikely(err))
>+		goto out_sysrq;
>+
>+	err = register_filesystem(&aufs_fs_type);
>+	if (unlikely(err))
>+		goto out_cache;
>+	pr_info(AUFS_NAME " " AUFS_VERSION "\n");
>+	return 0; /* success */
>+
>+ out_cache:
>+	destroy_cache();
>+ out_sysrq:
>+	au_sysrq_fin();
>+ out_inotify:
>+	au_inotify_fin();
>+ out_wkq:
>+	au_wkq_fin();
>+ out_sysaufs:
>+	sysaufs_fin();
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static void __exit aufs_exit(void)
>+{
>+	unregister_filesystem(&aufs_fs_type);
>+	destroy_cache();
>+
>+	au_sysrq_fin();
>+	au_inotify_fin();
>+	au_wkq_fin();
>+	sysaufs_fin();
>+}
>+
>+module_init(aufs_init);
>+module_exit(aufs_exit);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* fake Kconfig */
>+#if 1
>+
>+#ifdef CONFIG_AUFS_HINOTIFY
>+#ifndef CONFIG_INOTIFY
>+#error enable CONFIG_INOTIFY to use CONFIG_AUFS_HINOTIFY.
>+#endif
>+#endif /* CONFIG_AUFS_HINOTIFY */
>+
>+#if AUFS_BRANCH_MAX > 511 && PAGE_SIZE > 4096
>+#warning pagesize is larger than 4kb, \
>+	CONFIG_AUFS_BRANCH_MAX_511 or smaller is recommended.
>+#endif
>+
>+#ifdef CONFIG_AUFS_STAT
>+#ifndef CONFIG_SYSFS
>+#error CONFIG_AUFS_STAT requires CONFIG_SYSFS.
>+#endif
>+#endif /* CONFIG_AUFS_STAT */
>+
>+#ifdef CONFIG_AUFS_EXPORT
>+#if !defined(CONFIG_EXPORTFS) && !defined(CONFIG_EXPORTFS_MODULE)
>+#error CONFIG_AUFS_EXPORT requires CONFIG_EXPORTFS
>+#endif
>+#if defined(CONFIG_EXPORTFS_MODULE) && defined(CONFIG_AUFS)
>+#error need CONFIG_EXPORTFS = y to link aufs statically with CONFIG_AUFS_EXPORT
>+#endif
>+#endif /* CONFIG_AUFS_EXPORT */
>+
>+#ifdef CONFIG_AUFS_SEC_PERM_PATCH
>+#ifndef CONFIG_SECURITY
>+#warning CONFIG_AUFS_SEC_PERM_PATCH is unnecessary since CONFIG_SECURITY is disabled.
>+#endif
>+#ifdef CONFIG_AUFS
>+#warning CONFIG_AUFS_SEC_PERM_PATCH is unnecessary since CONFIG_AUFS is not a module.
>+#endif
>+#endif
>+
>+#ifdef CONFIG_AUFS_FAKE_DM
>+#warning CONFIG_AUFS_FAKE_DM is obsoleted in linux-2.6.24 and later.
>+#endif
>+
>+#ifdef CONFIG_AUFS_PUT_FILP_PATCH
>+#if !defined(CONFIG_NFS_FS) && !defined(CONFIG_NFS_FS_MODULE)
>+#warning CONFIG_AUFS_PUT_FILP_PATCH is unnecessary since CONFIG_NFS_FS is disabled.
>+#endif
>+#ifdef CONFIG_AUFS
>+#warning CONFIG_AUFS_PUT_FILP_PATCH is unnecessary since CONFIG_AUFS is not a module.
>+#endif
>+#endif /* CONFIG_AUFS_PUT_FILP_PATCH */
>+
>+#ifdef CONFIG_AUFS_LHASH_PATCH
>+#if !defined(CONFIG_NFS_FS) && !defined(CONFIG_NFS_FS_MODULE)
>+#warning CONFIG_AUFS_LHASH_PATCH is unnecessary since CONFIG_NFS_FS is disabled.
>+#endif
>+#endif
>+
>+#ifdef CONFIG_AUFS_KSIZE_PATCH
>+#warning CONFIG_AUFS_KSIZE_PATCH is unnecessary for linux-2.6.22 and later.
>+#endif
>+
>+#ifdef CONFIG_AUFS_WORKAROUND_FUSE
>+#if !defined(CONFIG_FUSE_FS) && !defined(CONFIG_FUSE_FS_MODULE)
>+#warning CONFIG_AUFS_WORKAROUND_FUSE is enabled while FUSE is disabled.
>+#endif
>+#endif
>+
>+#ifdef CONFIG_DEBUG_PROVE_LOCKING
>+#if MAX_LOCKDEP_SUBCLASSES < AuLsc_I_End
>+#warning lockdep will not work since aufs uses deeper locks.
>+#endif
>+#endif
>+
>+#ifdef CONFIG_AUFS_COMPAT
>+#warning CONFIG_AUFS_COMPAT will be removed in the near future.
>+#endif
>+
>+#endif
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/module.h linux-2.6.25.4-unionfs/fs/aufs/module.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/module.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/module.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,78 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * module initialization and module-global
>+ *
>+ * $Id: module.h,v 1.2 2008/04/21 01:33:00 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_MODULE_H__
>+#define __AUFS_MODULE_H__
>+
>+#ifdef __KERNEL__
>+
>+//#include <linux/slab.h>
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* module parameters */
>+extern short aufs_nwkq;
>+extern int sysaufs_brs;
>+
>+/* ---------------------------------------------------------------------- */
>+
>+extern char au_esc_chars[];
>+extern int au_dir_roflags;
>+
>+/* kmem cache */
>+enum {
>+	AuCache_DINFO,
>+	AuCache_ICNTNR,
>+	AuCache_FINFO,
>+	AuCache_VDIR,
>+	AuCache_DEHSTR,
>+#ifdef CONFIG_AUFS_HINOTIFY
>+	AuCache_HINOTIFY,
>+#endif
>+	AuCache_Last
>+};
>+
>+extern struct kmem_cache *au_cachep[];
>+
>+#define AuCacheArgs(type, sz)	(type), (sz), 0, SLAB_RECLAIM_ACCOUNT, NULL
>+#define AuCacheX(type, extra) \
>+	kmem_cache_create(AuCacheArgs(#type, sizeof(struct type) + extra))
>+#define AuCache(type)		AuCacheX(type, 0)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#define AuCacheFuncs(name, index) \
>+static inline void *au_cache_alloc_##name(void) \
>+{ return kmem_cache_alloc(au_cachep[index], GFP_KERNEL); } \
>+static inline void au_cache_free_##name(void *p) \
>+{ kmem_cache_free(au_cachep[index], p); }
>+
>+AuCacheFuncs(dinfo, AuCache_DINFO);
>+AuCacheFuncs(icntnr, AuCache_ICNTNR);
>+AuCacheFuncs(finfo, AuCache_FINFO);
>+AuCacheFuncs(vdir, AuCache_VDIR);
>+AuCacheFuncs(dehstr, AuCache_DEHSTR);
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_MODULE_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/opts.c linux-2.6.25.4-unionfs/fs/aufs/opts.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/opts.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/opts.c	2008-05-25 12:00:15 +0300
>@@ -0,0 +1,1465 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * mount options/flags
>+ *
>+ * $Id: opts.c,v 1.5 2008/05/19 01:49:36 sfjro Exp $
>+ */
>+
>+#include <linux/types.h> /* a distribution requires */
>+#include <linux/parser.h>
>+#include "aufs.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+enum {
>+	Opt_br,
>+	Opt_add, Opt_del, Opt_mod, Opt_reorder, Opt_append, Opt_prepend,
>+	Opt_idel, Opt_imod, Opt_ireorder,
>+	Opt_dirwh, Opt_rdcache, Opt_deblk, Opt_nhash, Opt_rendir,
>+	Opt_xino, Opt_zxino, Opt_noxino,
>+	Opt_trunc_xino, Opt_trunc_xino_v, Opt_notrunc_xino,
>+	Opt_trunc_xino_path, Opt_itrunc_xino,
>+	Opt_xinodir, Opt_xinonames, Opt_ixinonames,
>+	Opt_trunc_xib, Opt_notrunc_xib,
>+	Opt_dirperm1, Opt_nodirperm1,
>+	Opt_shwh, Opt_noshwh,
>+	Opt_plink, Opt_noplink, Opt_list_plink, Opt_clean_plink,
>+	Opt_udba,
>+	//Opt_lock, Opt_unlock,
>+	Opt_cmd, Opt_cmd_args,
>+	Opt_diropq_a, Opt_diropq_w,
>+	Opt_warn_perm, Opt_nowarn_perm,
>+	Opt_wbr_copyup, Opt_wbr_create,
>+	Opt_coo,
>+	Opt_dlgt, Opt_nodlgt,
>+	Opt_refrof, Opt_norefrof,
>+	Opt_verbose, Opt_noverbose,
>+	Opt_tail, Opt_ignore, Opt_ignore_silent, Opt_err
>+};
>+
>+static match_table_t options = {
>+	{Opt_br, "br=%s"},
>+	{Opt_br, "br:%s"},
>+
>+	{Opt_add, "add=%d:%s"},
>+	{Opt_add, "add:%d:%s"},
>+	{Opt_add, "ins=%d:%s"},
>+	{Opt_add, "ins:%d:%s"},
>+	{Opt_append, "append=%s"},
>+	{Opt_append, "append:%s"},
>+	{Opt_prepend, "prepend=%s"},
>+	{Opt_prepend, "prepend:%s"},
>+
>+	{Opt_del, "del=%s"},
>+	{Opt_del, "del:%s"},
>+	//{Opt_idel, "idel:%d"},
>+	{Opt_mod, "mod=%s"},
>+	{Opt_mod, "mod:%s"},
>+	{Opt_imod, "imod:%d:%s"},
>+
>+	{Opt_dirwh, "dirwh=%d"},
>+	{Opt_dirwh, "dirwh:%d"},
>+
>+	{Opt_xino, "xino=%s"},
>+	{Opt_xino, "xino:%s"},
>+	{Opt_xinodir, "xinodir=%s"},
>+	{Opt_xinodir, "xinodir:%s"},
>+	{Opt_noxino, "noxino"},
>+	{Opt_trunc_xino, "trunc_xino"},
>+	{Opt_trunc_xino_v, "trunc_xino_v=%d:%d"},
>+	{Opt_notrunc_xino, "notrunc_xino"},
>+	{Opt_trunc_xino_path, "trunc_xino=%s"},
>+	{Opt_trunc_xino_path, "trunc_xino:%s"},
>+	{Opt_itrunc_xino, "itrunc_xino=%d"},
>+	{Opt_itrunc_xino, "itrunc_xino:%d"},
>+	//{Opt_zxino, "zxino=%s"},
>+	{Opt_trunc_xib, "trunc_xib"},
>+	{Opt_notrunc_xib, "notrunc_xib"},
>+
>+	{Opt_plink, "plink"},
>+	{Opt_noplink, "noplink"},
>+#ifdef CONFIG_AUFS_DEBUG
>+	{Opt_list_plink, "list_plink"},
>+#endif
>+	{Opt_clean_plink, "clean_plink"},
>+
>+	{Opt_udba, "udba=%s"},
>+
>+	{Opt_diropq_a, "diropq=always"},
>+	{Opt_diropq_a, "diropq=a"},
>+	{Opt_diropq_w, "diropq=whiteouted"},
>+	{Opt_diropq_w, "diropq=w"},
>+
>+	{Opt_warn_perm, "warn_perm"},
>+	{Opt_nowarn_perm, "nowarn_perm"},
>+
>+#ifdef CONFIG_AUFS_DLGT
>+	{Opt_dlgt, "dlgt"},
>+	{Opt_nodlgt, "nodlgt"},
>+
>+	{Opt_dirperm1, "dirperm1"},
>+	{Opt_nodirperm1, "nodirperm1"},
>+#endif
>+
>+#ifdef CONFIG_AUFS_SHWH
>+	{Opt_shwh, "shwh"},
>+	{Opt_noshwh, "noshwh"},
>+#endif
>+
>+	{Opt_rendir, "rendir=%d"},
>+	{Opt_rendir, "rendir:%d"},
>+
>+	{Opt_refrof, "refrof"},
>+	{Opt_norefrof, "norefrof"},
>+
>+	{Opt_verbose, "verbose"},
>+	{Opt_verbose, "v"},
>+	{Opt_noverbose, "noverbose"},
>+	{Opt_noverbose, "quiet"},
>+	{Opt_noverbose, "q"},
>+	{Opt_noverbose, "silent"},
>+
>+	{Opt_rdcache, "rdcache=%d"},
>+	{Opt_rdcache, "rdcache:%d"},
>+
>+	{Opt_coo, "coo=%s"},
>+
>+	{Opt_wbr_create, "create=%s"},
>+	{Opt_wbr_create, "create:%s"},
>+	{Opt_wbr_create, "create_policy=%s"},
>+	{Opt_wbr_create, "create_policy:%s"},
>+	{Opt_wbr_copyup, "cpup=%s"},
>+	{Opt_wbr_copyup, "cpup:%s"},
>+	{Opt_wbr_copyup, "copyup=%s"},
>+	{Opt_wbr_copyup, "copyup:%s"},
>+	{Opt_wbr_copyup, "copyup_policy=%s"},
>+	{Opt_wbr_copyup, "copyup_policy:%s"},
>+
>+	/* internal use for the scripts */
>+	{Opt_ignore_silent, "si=%s"},
>+
>+	{Opt_br, "dirs=%s"},
>+	{Opt_ignore, "debug=%d"},
>+	{Opt_ignore, "delete=whiteout"},
>+	{Opt_ignore, "delete=all"},
>+	{Opt_ignore, "imap=%s"},
>+
>+	{Opt_err, NULL}
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static const char *au_parser_pattern(int val, struct match_token *token)
>+{
>+	while (token->pattern) {
>+		if (token->token == val)
>+			return token->pattern;
>+		token++;
>+	}
>+	BUG();
>+	return "??";
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#define RW		"rw"
>+#define RO		"ro"
>+#define WH		"wh"
>+#define RR		"rr"
>+#define NoLinkWH	"nolwh"
>+
>+static match_table_t brperms = {
>+	{AuBr_RR, RR},
>+	{AuBr_RO, RO},
>+	{AuBr_RW, RW},
>+
>+	{AuBr_RRWH, RR "+" WH},
>+	{AuBr_ROWH, RO "+" WH},
>+	{AuBr_RWNoLinkWH, RW "+" NoLinkWH},
>+
>+	{AuBr_ROWH, "nfsro"},
>+	{AuBr_RO, NULL}
>+};
>+
>+static noinline_for_stack int br_perm_val(char *perm)
>+{
>+	int val;
>+	substring_t args[MAX_OPT_ARGS];
>+
>+	AuDebugOn(!perm || !*perm);
>+	LKTRTrace("perm %s\n", perm);
>+	val = match_token(perm, brperms, args);
>+	AuTraceErr(val);
>+	return val;
>+}
>+
>+const char *au_optstr_br_perm(int brperm)
>+{
>+	return au_parser_pattern(brperm, brperms);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static match_table_t udbalevel = {
>+	{AuOpt_UDBA_REVAL, "reval"},
>+#ifdef CONFIG_AUFS_HINOTIFY
>+	{AuOpt_UDBA_INOTIFY, "inotify"},
>+#endif
>+	{AuOpt_UDBA_NONE, "none"},
>+	{-1, NULL}
>+};
>+
>+static noinline_for_stack int udba_val(char *str)
>+{
>+	substring_t args[MAX_OPT_ARGS];
>+	return match_token(str, udbalevel, args);
>+}
>+
>+const char *au_optstr_udba(int udba)
>+{
>+	return au_parser_pattern(udba, udbalevel);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static match_table_t coolevel = {
>+	{AuOpt_COO_NONE, "none"},
>+	{AuOpt_COO_LEAF, "leaf"},
>+	{AuOpt_COO_ALL, "all"},
>+	{-1, NULL}
>+};
>+
>+static noinline_for_stack int coo_val(char *str)
>+{
>+	substring_t args[MAX_OPT_ARGS];
>+	return match_token(str, coolevel, args);
>+}
>+
>+const char *au_optstr_coo(int coo)
>+{
>+	return au_parser_pattern(coo, coolevel);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static match_table_t au_wbr_create_policy = {
>+	{AuWbrCreate_TDP, "tdp"},
>+	{AuWbrCreate_TDP, "top-down-parent"},
>+	{AuWbrCreate_RR, "rr"},
>+	{AuWbrCreate_RR, "round-robin"},
>+	{AuWbrCreate_MFS, "mfs"},
>+	{AuWbrCreate_MFS, "most-free-space"},
>+	{AuWbrCreate_MFSV, "mfs:%d"},
>+	{AuWbrCreate_MFSV, "most-free-space:%d"},
>+
>+	{AuWbrCreate_MFSRR, "mfsrr:%d"},
>+	{AuWbrCreate_MFSRRV, "mfsrr:%d:%d"},
>+	{AuWbrCreate_PMFS, "pmfs"},
>+	{AuWbrCreate_PMFSV, "pmfs:%d"},
>+
>+	{-1, NULL}
>+};
>+
>+/* cf. linux/lib/parser.c */
>+static int au_match_ull(substring_t *s, unsigned long long *result, int base)
>+{
>+	char *endp;
>+	char *buf;
>+	int ret;
>+
>+	buf = kmalloc(s->to - s->from + 1, GFP_KERNEL);
>+	if (!buf)
>+		return -ENOMEM;
>+	memcpy(buf, s->from, s->to - s->from);
>+	buf[s->to - s->from] = '\0';
>+	*result = simple_strtoull(buf, &endp, base);
>+	ret = 0;
>+	if (endp == buf)
>+		ret = -EINVAL;
>+	kfree(buf);
>+	return ret;
>+}
>+
>+static int au_wbr_mfs_wmark(substring_t *arg, char *str,
>+			    struct au_opt_wbr_create *create)
>+{
>+	int err;
>+	u64 ull;
>+
>+	err = 0;
>+	if (!au_match_ull(arg, &ull, 0))
>+		create->mfsrr_watermark = ull;
>+	else {
>+		AuErr("bad integer in %s\n", str);
>+		err = -EINVAL;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int au_wbr_mfs_sec(substring_t *arg, char *str,
>+			  struct au_opt_wbr_create *create)
>+{
>+	int n, err;
>+
>+	err = 0;
>+	if (!match_int(arg, &n) && 0 <= n)
>+		create->mfs_second = n;
>+	else {
>+		AuErr("bad integer in %s\n", str);
>+		err = -EINVAL;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static noinline_for_stack int
>+au_wbr_create_val(char *str, struct au_opt_wbr_create *create)
>+{
>+	int err, e;
>+	substring_t args[MAX_OPT_ARGS];
>+
>+	err = match_token(str, au_wbr_create_policy, args);
>+	create->wbr_create = err;
>+	switch (err) {
>+	case AuWbrCreate_MFSRRV:
>+		e = au_wbr_mfs_wmark(&args[0], str, create);
>+		if (!e)
>+			e = au_wbr_mfs_sec(&args[1], str, create);
>+		if (unlikely(e))
>+			err = e;
>+		break;
>+	case AuWbrCreate_MFSRR:
>+		e = au_wbr_mfs_wmark(&args[0], str, create);
>+		if (unlikely(e)) {
>+			err = e;
>+			break;
>+		}
>+		/*FALLTHROUGH*/
>+	case AuWbrCreate_MFS:
>+	case AuWbrCreate_PMFS:
>+		create->mfs_second = AUFS_MFS_SECOND_DEF;
>+		break;
>+	case AuWbrCreate_MFSV:
>+	case AuWbrCreate_PMFSV:
>+		e = au_wbr_mfs_sec(&args[0], str, create);
>+		if (unlikely(e))
>+			err = e;
>+		break;
>+	}
>+
>+	return err;
>+}
>+
>+const char *au_optstr_wbr_create(int wbr_create)
>+{
>+	return au_parser_pattern(wbr_create, au_wbr_create_policy);
>+}
>+
>+static match_table_t au_wbr_copyup_policy = {
>+	{AuWbrCopyup_TDP, "tdp"},
>+	{AuWbrCopyup_TDP, "top-down-parent"},
>+	{AuWbrCopyup_BUP, "bup"},
>+	{AuWbrCopyup_BUP, "bottom-up-parent"},
>+	{AuWbrCopyup_BU, "bu"},
>+	{AuWbrCopyup_BU, "bottom-up"},
>+	{-1, NULL}
>+};
>+
>+static noinline_for_stack int au_wbr_copyup_val(char *str)
>+{
>+	substring_t args[MAX_OPT_ARGS];
>+	return match_token(str, au_wbr_copyup_policy, args);
>+}
>+
>+const char *au_optstr_wbr_copyup(int wbr_copyup)
>+{
>+	return au_parser_pattern(wbr_copyup, au_wbr_copyup_policy);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static const int lkup_dirflags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
>+
>+static noinline_for_stack void dump_opts(struct au_opts *opts)
>+{
>+#ifdef CONFIG_AUFS_DEBUG
>+	/* reduce stack space */
>+	union {
>+		struct au_opt_add *add;
>+		struct au_opt_del *del;
>+		struct au_opt_mod *mod;
>+		struct au_opt_xino *xino;
>+		struct au_opt_xino_itrunc *xino_itrunc;
>+		struct au_opt_wbr_create *create;
>+	} u;
>+	struct au_opt *opt;
>+
>+	AuTraceEnter();
>+
>+	opt = opts->opt;
>+	while (/* opt < opts_tail && */ opt->type != Opt_tail) {
>+		switch (opt->type) {
>+		case Opt_add:
>+			u.add = &opt->add;
>+			LKTRTrace("add {b%d, %s, 0x%x, %p}\n",
>+				  u.add->bindex, u.add->path, u.add->perm,
>+				  u.add->nd.path.dentry);
>+			break;
>+		case Opt_del:
>+		case Opt_idel:
>+			u.del = &opt->del;
>+			LKTRTrace("del {%s, %p}\n", u.del->path, u.del->h_root);
>+			break;
>+		case Opt_mod:
>+		case Opt_imod:
>+			u.mod = &opt->mod;
>+			LKTRTrace("mod {%s, 0x%x, %p}\n",
>+				  u.mod->path, u.mod->perm, u.mod->h_root);
>+			break;
>+		case Opt_append:
>+			u.add = &opt->add;
>+			LKTRTrace("append {b%d, %s, 0x%x, %p}\n",
>+				  u.add->bindex, u.add->path, u.add->perm,
>+				  u.add->nd.path.dentry);
>+			break;
>+		case Opt_prepend:
>+			u.add = &opt->add;
>+			LKTRTrace("prepend {b%d, %s, 0x%x, %p}\n",
>+				  u.add->bindex, u.add->path, u.add->perm,
>+				  u.add->nd.path.dentry);
>+			break;
>+		case Opt_dirwh:
>+			LKTRTrace("dirwh %d\n", opt->dirwh);
>+			break;
>+		case Opt_rdcache:
>+			LKTRTrace("rdcache %d\n", opt->rdcache);
>+			break;
>+		case Opt_xino:
>+			u.xino = &opt->xino;
>+			LKTRTrace("xino {%s %.*s}\n",
>+				  u.xino->path,
>+				  AuDLNPair(u.xino->file->f_dentry));
>+			break;
>+		case Opt_trunc_xino:
>+			LKTRLabel(trunc_xino);
>+			break;
>+		case Opt_notrunc_xino:
>+			LKTRLabel(notrunc_xino);
>+			break;
>+		case Opt_trunc_xino_path:
>+		case Opt_itrunc_xino:
>+			u.xino_itrunc = &opt->xino_itrunc;
>+			LKTRTrace("trunc_xino %d\n", u.xino_itrunc->bindex);
>+			break;
>+
>+		case Opt_noxino:
>+			LKTRLabel(noxino);
>+			break;
>+		case Opt_trunc_xib:
>+			LKTRLabel(trunc_xib);
>+			break;
>+		case Opt_notrunc_xib:
>+			LKTRLabel(notrunc_xib);
>+			break;
>+		case Opt_dirperm1:
>+			LKTRLabel(dirperm1);
>+			break;
>+		case Opt_nodirperm1:
>+			LKTRLabel(nodirperm1);
>+			break;
>+		case Opt_shwh:
>+			LKTRLabel(shwh);
>+			break;
>+		case Opt_noshwh:
>+			LKTRLabel(noshwh);
>+			break;
>+		case Opt_plink:
>+			LKTRLabel(plink);
>+			break;
>+		case Opt_noplink:
>+			LKTRLabel(noplink);
>+			break;
>+		case Opt_list_plink:
>+			LKTRLabel(list_plink);
>+			break;
>+		case Opt_clean_plink:
>+			LKTRLabel(clean_plink);
>+			break;
>+		case Opt_udba:
>+			LKTRTrace("udba %d, %s\n",
>+				  opt->udba, au_optstr_udba(opt->udba));
>+			break;
>+		case Opt_diropq_a:
>+			LKTRLabel(diropq_a);
>+			break;
>+		case Opt_diropq_w:
>+			LKTRLabel(diropq_w);
>+			break;
>+		case Opt_warn_perm:
>+			LKTRLabel(warn_perm);
>+			break;
>+		case Opt_nowarn_perm:
>+			LKTRLabel(nowarn_perm);
>+			break;
>+		case Opt_dlgt:
>+			LKTRLabel(dlgt);
>+			break;
>+		case Opt_nodlgt:
>+			LKTRLabel(nodlgt);
>+			break;
>+		case Opt_refrof:
>+			LKTRLabel(refrof);
>+			break;
>+		case Opt_norefrof:
>+			LKTRLabel(norefrof);
>+			break;
>+		case Opt_verbose:
>+			LKTRLabel(verbose);
>+			break;
>+		case Opt_noverbose:
>+			LKTRLabel(noverbose);
>+			break;
>+		case Opt_coo:
>+			LKTRTrace("coo %d, %s\n",
>+				  opt->coo, au_optstr_coo(opt->coo));
>+			break;
>+		case Opt_wbr_create:
>+			u.create = &opt->wbr_create;
>+			LKTRTrace("create %d, %s\n", u.create->wbr_create,
>+				  au_optstr_wbr_create(u.create->wbr_create));
>+			switch (u.create->wbr_create) {
>+			case AuWbrCreate_MFSV:
>+			case AuWbrCreate_PMFSV:
>+				LKTRTrace("%d sec\n", u.create->mfs_second);
>+				break;
>+			case AuWbrCreate_MFSRR:
>+				LKTRTrace("%Lu watermark\n",
>+					  u.create->mfsrr_watermark);
>+				break;
>+			case AuWbrCreate_MFSRRV:
>+				LKTRTrace("%Lu watermark, %d sec\n",
>+					  u.create->mfsrr_watermark,
>+					  u.create->mfs_second);
>+				break;
>+			}
>+			break;
>+		case Opt_wbr_copyup:
>+			LKTRTrace("copyup %d, %s\n", opt->wbr_copyup,
>+				  au_optstr_wbr_copyup(opt->wbr_copyup));
>+			break;
>+		default:
>+			BUG();
>+		}
>+		opt++;
>+	}
>+#endif
>+}
>+
>+void au_opts_free(struct au_opts *opts)
>+{
>+	struct au_opt *opt;
>+
>+	AuTraceEnter();
>+
>+	opt = opts->opt;
>+	while (opt->type != Opt_tail) {
>+		switch (opt->type) {
>+		case Opt_add:
>+		case Opt_append:
>+		case Opt_prepend:
>+			path_put(&opt->add.nd.path);
>+			break;
>+		case Opt_del:
>+		case Opt_idel:
>+			dput(opt->del.h_root);
>+			break;
>+		case Opt_mod:
>+		case Opt_imod:
>+			dput(opt->mod.h_root);
>+			break;
>+		case Opt_xino:
>+			fput(opt->xino.file);
>+			break;
>+		}
>+		opt++;
>+	}
>+}
>+
>+static int opt_add(struct au_opt *opt, char *opt_str, struct super_block *sb,
>+		   aufs_bindex_t bindex)
>+{
>+	int err;
>+	struct au_opt_add *add = &opt->add;
>+	char *p;
>+
>+	LKTRTrace("%s, b%d\n", opt_str, bindex);
>+
>+	add->bindex = bindex;
>+	add->perm = AuBr_Last;
>+	add->path = opt_str;
>+	p = strchr(opt_str, '=');
>+	if (unlikely(p)) {
>+		*p++ = 0;
>+		if (*p)
>+			add->perm = br_perm_val(p);
>+	}
>+
>+	/* LSM may detect it */
>+	/* do not superio. */
>+	err = vfsub_path_lookup(add->path, lkup_dirflags, &add->nd);
>+	//err = -1;
>+	if (!err) {
>+		if (!p /* && add->perm == AuBr_Last */) {
>+			add->perm = AuBr_RO;
>+			if (au_test_def_rr(add->nd.path.dentry->d_sb))
>+				add->perm = AuBr_RR;
>+			if (!bindex && !(sb->s_flags & MS_RDONLY))
>+				add->perm = AuBr_RW;
>+#ifdef CONFIG_AUFS_COMPAT
>+			add->perm = AuBr_RW;
>+#endif
>+		}
>+		opt->type = Opt_add;
>+		goto out;
>+	}
>+	AuErr("lookup failed %s (%d)\n", add->path, err);
>+	err = -EINVAL;
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* called without aufs lock */
>+int au_opts_parse(struct super_block *sb, unsigned long flags, char *str,
>+		  struct au_opts *opts)
>+{
>+	int err, n, token, skipped;
>+	struct dentry *root;
>+	struct au_opt *opt, *opt_tail;
>+	char *opt_str, *p;
>+	substring_t args[MAX_OPT_ARGS];
>+	aufs_bindex_t bindex, bend;
>+	struct nameidata nd;
>+	union {
>+		struct au_opt_del *del;
>+		struct au_opt_mod *mod;
>+		struct au_opt_xino *xino;
>+		struct au_opt_xino_itrunc *xino_itrunc;
>+		struct au_opt_wbr_create *create;
>+	} u;
>+	struct file *file;
>+
>+	LKTRTrace("%s, nopts %d\n", str, opts->max_opt);
>+
>+	root = sb->s_root;
>+	err = 0;
>+	bindex = 0;
>+	opt = opts->opt;
>+	opt_tail = opt + opts->max_opt - 1;
>+	opt->type = Opt_tail;
>+	while (!err && (opt_str = strsep(&str, ",")) && *opt_str) {
>+		err = -EINVAL;
>+		token = match_token(opt_str, options, args);
>+		LKTRTrace("%s, token %d, args[0]{%p, %p}\n",
>+			  opt_str, token, args[0].from, args[0].to);
>+
>+		skipped = 0;
>+		switch (token) {
>+		case Opt_br:
>+			err = 0;
>+			while (!err && (opt_str = strsep(&args[0].from, ":"))
>+			       && *opt_str) {
>+				err = opt_add(opt, opt_str, sb, bindex++);
>+				//if (LktrCond) err = -1;
>+				if (unlikely(!err && ++opt > opt_tail)) {
>+					err = -E2BIG;
>+					break;
>+				}
>+				opt->type = Opt_tail;
>+				skipped = 1;
>+			}
>+			break;
>+		case Opt_add:
>+			if (unlikely(match_int(&args[0], &n))) {
>+				AuErr("bad integer in %s\n", opt_str);
>+				break;
>+			}
>+			bindex = n;
>+			err = opt_add(opt, args[1].from, sb, bindex);
>+			break;
>+		case Opt_append:
>+			err = opt_add(opt, args[0].from, sb, /*dummy bindex*/1);
>+			if (!err)
>+				opt->type = token;
>+			break;
>+		case Opt_prepend:
>+			err = opt_add(opt, args[0].from, sb, /*bindex*/0);
>+			if (!err)
>+				opt->type = token;
>+			break;
>+		case Opt_del:
>+			u.del = &opt->del;
>+			u.del->path = args[0].from;
>+			LKTRTrace("del path %s\n", u.del->path);
>+			/* LSM may detect it */
>+			/* do not superio. */
>+			err = vfsub_path_lookup(u.del->path, lkup_dirflags,
>+						&nd);
>+			if (unlikely(err)) {
>+				AuErr("lookup failed %s (%d)\n",
>+				      u.del->path, err);
>+				break;
>+			}
>+			u.del->h_root = dget(nd.path.dentry);
>+			path_put(&nd.path);
>+			opt->type = token;
>+			break;
>+		case Opt_mod:
>+			u.mod = &opt->mod;
>+			u.mod->path = args[0].from;
>+			p = strchr(u.mod->path, '=');
>+			if (unlikely(!p)) {
>+				AuErr("no permssion %s\n", opt_str);
>+				break;
>+			}
>+			*p++ = 0;
>+			u.mod->perm = br_perm_val(p);
>+			LKTRTrace("mod path %s, perm 0x%x, %s\n",
>+				  u.mod->path, u.mod->perm, p);
>+			/* LSM may detect it */
>+			/* do not superio. */
>+			err = vfsub_path_lookup(u.mod->path, lkup_dirflags,
>+						&nd);
>+			if (unlikely(err)) {
>+				AuErr("lookup failed %s (%d)\n",
>+				      u.mod->path, err);
>+				break;
>+			}
>+			u.mod->h_root = dget(nd.path.dentry);
>+			path_put(&nd.path);
>+			opt->type = token;
>+			break;
>+#ifdef IMOD
>+		case Opt_imod:
>+			u.mod = &opt->mod;
>+			u.mod->path = "(indexed)";
>+			if (unlikely(match_int(&args[0], &n))) {
>+				AuErr("bad integer in %s\n", opt_str);
>+				break;
>+			}
>+			bindex = n;
>+			aufs_read_lock(root, AuLock_FLUSH);
>+			if (bindex < 0 || au_sbend(sb) < bindex) {
>+				AuErr("out of bounds, %d\n", bindex);
>+				aufs_read_unlock(root, !AuLock_IR);
>+				break;
>+			}
>+			u.mod->perm = br_perm_val(args[1].from);
>+			LKTRTrace("mod path %s, perm 0x%x, %s\n",
>+				  u.mod->path, u.mod->perm, args[1].from);
>+			err = 0;
>+			u.mod->h_root = dget(au_h_dptr(root, bindex));
>+			opt->type = token;
>+			aufs_read_unlock(root, !AuLock_IR);
>+			break;
>+#endif
>+		case Opt_xino:
>+			u.xino = &opt->xino;
>+			file = au_xino_create(sb, args[0].from, /*silent*/0,
>+					      /*parent*/NULL);
>+			err = PTR_ERR(file);
>+			if (IS_ERR(file))
>+				break;
>+			err = -EINVAL;
>+			if (unlikely(file->f_dentry->d_sb == sb)) {
>+				fput(file);
>+				AuErr("%s must be outside\n", args[0].from);
>+				break;
>+			}
>+			err = 0;
>+			u.xino->file = file;
>+			u.xino->path = args[0].from;
>+			opt->type = token;
>+			break;
>+
>+		case Opt_trunc_xino_path:
>+			u.xino_itrunc = &opt->xino_itrunc;
>+			p = args[0].from;
>+			LKTRTrace("trunc_xino path %s\n", p);
>+			/* LSM may detect it */
>+			/* do not superio. */
>+			err = vfsub_path_lookup(p, lkup_dirflags, &nd);
>+			if (unlikely(err)) {
>+				AuErr("lookup failed %s (%d)\n", p , err);
>+				break;
>+			}
>+			u.xino_itrunc->bindex = -1;
>+			aufs_read_lock(root, AuLock_FLUSH);
>+			bend = au_sbend(sb);
>+			for (bindex = 0; bindex <= bend; bindex++) {
>+				if (au_h_dptr(root, bindex) == nd.path.dentry) {
>+					u.xino_itrunc->bindex = bindex;
>+					break;
>+				}
>+			}
>+			aufs_read_unlock(root, !AuLock_IR);
>+			path_put(&nd.path);
>+			if (unlikely(u.xino_itrunc->bindex < 0)) {
>+				AuErr("no such branch %s\n", p);
>+				err = -EINVAL;
>+				break;
>+			}
>+			opt->type = token;
>+			break;
>+
>+		case Opt_itrunc_xino:
>+			u.xino_itrunc = &opt->xino_itrunc;
>+			if (unlikely(match_int(&args[0], &n))) {
>+				AuErr("bad integer in %s\n", opt_str);
>+				break;
>+			}
>+			u.xino_itrunc->bindex = n;
>+			aufs_read_lock(root, AuLock_FLUSH);
>+			if (n < 0 || au_sbend(sb) < n) {
>+				AuErr("out of bounds, %d\n", n);
>+				aufs_read_unlock(root, !AuLock_IR);
>+				break;
>+			}
>+			aufs_read_unlock(root, !AuLock_IR);
>+			err = 0;
>+			opt->type = token;
>+			break;
>+
>+		case Opt_dirwh:
>+			if (unlikely(match_int(&args[0], &opt->dirwh)))
>+				break;
>+			err = 0;
>+			opt->type = token;
>+			break;
>+
>+		case Opt_rdcache:
>+			if (unlikely(match_int(&args[0], &opt->rdcache)))
>+				break;
>+			err = 0;
>+			opt->type = token;
>+			break;
>+
>+		case Opt_shwh:
>+			if (flags & MS_RDONLY) {
>+				err = 0;
>+				opt->type = token;
>+			} else
>+				AuErr("shwh requires ro\n");
>+			break;
>+
>+		case Opt_trunc_xino:
>+		case Opt_notrunc_xino:
>+		case Opt_noxino:
>+		case Opt_trunc_xib:
>+		case Opt_notrunc_xib:
>+		case Opt_dirperm1:
>+		case Opt_nodirperm1:
>+		case Opt_noshwh:
>+		case Opt_plink:
>+		case Opt_noplink:
>+		case Opt_list_plink:
>+		case Opt_clean_plink:
>+		case Opt_diropq_a:
>+		case Opt_diropq_w:
>+		case Opt_warn_perm:
>+		case Opt_nowarn_perm:
>+		case Opt_dlgt:
>+		case Opt_nodlgt:
>+		case Opt_refrof:
>+		case Opt_norefrof:
>+		case Opt_verbose:
>+		case Opt_noverbose:
>+			err = 0;
>+			opt->type = token;
>+			break;
>+
>+		case Opt_udba:
>+			opt->udba = udba_val(args[0].from);
>+			if (opt->udba >= 0) {
>+				err = 0;
>+				opt->type = token;
>+			}
>+			break;
>+
>+		case Opt_wbr_create:
>+			u.create = &opt->wbr_create;
>+			u.create->wbr_create
>+				= au_wbr_create_val(args[0].from, u.create);
>+			if (u.create->wbr_create >= 0) {
>+				err = 0;
>+				opt->type = token;
>+			}
>+			break;
>+		case Opt_wbr_copyup:
>+			opt->wbr_copyup = au_wbr_copyup_val(args[0].from);
>+			if (opt->wbr_copyup >= 0) {
>+				err = 0;
>+				opt->type = token;
>+			}
>+			break;
>+
>+		case Opt_coo:
>+			opt->coo = coo_val(args[0].from);
>+			if (opt->coo >= 0) {
>+				err = 0;
>+				opt->type = token;
>+			}
>+			break;
>+
>+		case Opt_ignore:
>+#ifndef CONFIG_AUFS_COMPAT
>+			AuWarn("ignored %s\n", opt_str);
>+#endif
>+		case Opt_ignore_silent:
>+			skipped = 1;
>+			err = 0;
>+			break;
>+		case Opt_err:
>+			AuErr("unknown option %s\n", opt_str);
>+			break;
>+		}
>+
>+		if (!err && !skipped) {
>+			if (unlikely(++opt > opt_tail)) {
>+				err = -E2BIG;
>+				opt--;
>+				opt->type = Opt_tail;
>+				break;
>+			}
>+			opt->type = Opt_tail;
>+		}
>+	}
>+
>+	dump_opts(opts);
>+	if (unlikely(err))
>+		au_opts_free(opts);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * returns,
>+ * plus: processed without an error
>+ * zero: unprocessed
>+ */
>+static int au_opt_simple(struct super_block *sb, struct au_opt *opt,
>+			 struct au_opts *opts)
>+{
>+	int err;
>+	struct au_sbinfo *sbinfo;
>+	struct au_opt_wbr_create *create;
>+
>+	AuTraceEnter();
>+
>+	err = 1; /* handled */
>+	sbinfo = au_sbi(sb);
>+	switch (opt->type) {
>+	case Opt_udba:
>+		sbinfo->si_mntflags &= ~AuOptMask_UDBA;
>+		sbinfo->si_mntflags |= opt->udba;
>+		opts->given_udba |= opt->udba;
>+		break;
>+
>+	case Opt_plink:
>+		au_opt_set(sbinfo->si_mntflags, PLINK);
>+		break;
>+	case Opt_noplink:
>+		if (au_opt_test(sbinfo->si_mntflags, PLINK))
>+			au_plink_put(sb);
>+		au_opt_clr(sbinfo->si_mntflags, PLINK);
>+		break;
>+	case Opt_list_plink:
>+		if (au_opt_test(sbinfo->si_mntflags, PLINK))
>+			au_plink_list(sb);
>+		break;
>+	case Opt_clean_plink:
>+		if (au_opt_test(sbinfo->si_mntflags, PLINK))
>+			au_plink_put(sb);
>+		break;
>+
>+	case Opt_diropq_a:
>+		au_opt_set(sbinfo->si_mntflags, ALWAYS_DIROPQ);
>+		break;
>+	case Opt_diropq_w:
>+		au_opt_clr(sbinfo->si_mntflags, ALWAYS_DIROPQ);
>+		break;
>+
>+	case Opt_dlgt:
>+		au_opt_set(sbinfo->si_mntflags, DLGT);
>+		break;
>+	case Opt_nodlgt:
>+		au_opt_clr(sbinfo->si_mntflags, DLGT);
>+		break;
>+
>+	case Opt_warn_perm:
>+		au_opt_set(sbinfo->si_mntflags, WARN_PERM);
>+		break;
>+	case Opt_nowarn_perm:
>+		au_opt_clr(sbinfo->si_mntflags, WARN_PERM);
>+		break;
>+
>+	case Opt_refrof:
>+		au_opt_set(sbinfo->si_mntflags, REFROF);
>+		break;
>+	case Opt_norefrof:
>+		//au_opt_set(sbinfo->si_mntflags, COO_LEAF);
>+		au_opt_clr(sbinfo->si_mntflags, REFROF);
>+		break;
>+
>+	case Opt_verbose:
>+		au_opt_set(sbinfo->si_mntflags, VERBOSE);
>+		break;
>+	case Opt_noverbose:
>+		au_opt_clr(sbinfo->si_mntflags, VERBOSE);
>+		break;
>+
>+	case Opt_wbr_create:
>+		create = &opt->wbr_create;
>+		if (sbinfo->si_wbr_create_ops->fin) {
>+			err = sbinfo->si_wbr_create_ops->fin(sb);
>+			if (!err)
>+				err = 1;
>+		}
>+		sbinfo->si_wbr_create = create->wbr_create;
>+		sbinfo->si_wbr_create_ops
>+			= au_wbr_create_ops + create->wbr_create;
>+		switch (create->wbr_create) {
>+		case AuWbrCreate_MFSRRV:
>+		case AuWbrCreate_MFSRR:
>+			sbinfo->si_wbr_mfs.mfsrr_watermark
>+				= create->mfsrr_watermark;
>+			/*FALLTHROUGH*/
>+		case AuWbrCreate_MFS:
>+		case AuWbrCreate_MFSV:
>+		case AuWbrCreate_PMFS:
>+		case AuWbrCreate_PMFSV:
>+			sbinfo->si_wbr_mfs.mfs_expire = create->mfs_second * HZ;
>+			break;
>+		}
>+		if (sbinfo->si_wbr_create_ops->init)
>+			sbinfo->si_wbr_create_ops->init(sb); /* ignore */
>+		break;
>+	case Opt_wbr_copyup:
>+		sbinfo->si_wbr_copyup = opt->wbr_copyup;
>+		sbinfo->si_wbr_copyup_ops = au_wbr_copyup_ops + opt->wbr_copyup;
>+		break;
>+
>+	case Opt_coo:
>+		sbinfo->si_mntflags &= ~AuOptMask_COO;
>+		sbinfo->si_mntflags |= opt->coo;
>+		break;
>+
>+	case Opt_dirwh:
>+		sbinfo->si_dirwh = opt->dirwh;
>+		break;
>+
>+	case Opt_rdcache:
>+		sbinfo->si_rdcache = opt->rdcache * HZ;
>+		break;
>+
>+	case Opt_trunc_xino:
>+		au_opt_set(sbinfo->si_mntflags, TRUNC_XINO);
>+		break;
>+	case Opt_notrunc_xino:
>+		au_opt_clr(sbinfo->si_mntflags, TRUNC_XINO);
>+		break;
>+
>+	case Opt_dirperm1:
>+		au_opt_set(sbinfo->si_mntflags, DIRPERM1);
>+		break;
>+	case Opt_nodirperm1:
>+		au_opt_clr(sbinfo->si_mntflags, DIRPERM1);
>+		break;
>+
>+	case Opt_shwh:
>+		au_opt_set(sbinfo->si_mntflags, SHWH);
>+		break;
>+	case Opt_noshwh:
>+		au_opt_clr(sbinfo->si_mntflags, SHWH);
>+		break;
>+
>+	case Opt_trunc_xino_path:
>+	case Opt_itrunc_xino:
>+		err = au_xino_trunc(sb, opt->xino_itrunc.bindex);
>+		if (!err)
>+			err = 1;
>+		break;
>+
>+	case Opt_trunc_xib:
>+		au_fset_opts(opts->flags, TRUNC_XIB);
>+		break;
>+	case Opt_notrunc_xib:
>+		au_fclr_opts(opts->flags, TRUNC_XIB);
>+		break;
>+
>+	default:
>+		err = 0;
>+		break;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * returns tri-state.
>+ * plus: processed without an error
>+ * zero: unprocessed
>+ * minus: error
>+ */
>+static int au_opt_br(struct super_block *sb, struct au_opt *opt,
>+		     struct au_opts *opts)
>+{
>+	int err, do_refresh;
>+
>+	AuTraceEnter();
>+
>+	err = 0;
>+	switch (opt->type) {
>+	case Opt_append:
>+		opt->add.bindex = au_sbend(sb) + 1;
>+		if (unlikely(opt->add.bindex < 0))
>+			opt->add.bindex = 0;
>+		goto add;
>+	case Opt_prepend:
>+		opt->add.bindex = 0;
>+	add:
>+	case Opt_add:
>+		err = au_br_add(sb, &opt->add,
>+				au_ftest_opts(opts->flags, REMOUNT));
>+		if (!err) {
>+			err = 1;
>+			au_fset_opts(opts->flags, REFRESH_DIR);
>+			if (unlikely(au_br_whable(opt->add.perm)))
>+				au_fset_opts(opts->flags, REFRESH_NONDIR);
>+		}
>+		break;
>+
>+	case Opt_del:
>+	case Opt_idel:
>+		err = au_br_del(sb, &opt->del,
>+				au_ftest_opts(opts->flags, REMOUNT));
>+		if (!err) {
>+			err = 1;
>+			au_fset_opts(opts->flags, TRUNC_XIB);
>+			au_fset_opts(opts->flags, REFRESH_DIR);
>+			au_fset_opts(opts->flags, REFRESH_NONDIR);
>+		}
>+		break;
>+
>+	case Opt_mod:
>+	case Opt_imod:
>+		err = au_br_mod(sb, &opt->mod,
>+				au_ftest_opts(opts->flags, REMOUNT),
>+				&do_refresh);
>+		if (!err) {
>+			err = 1;
>+			if (unlikely(do_refresh)) {
>+				au_fset_opts(opts->flags, REFRESH_DIR);
>+				au_fset_opts(opts->flags, REFRESH_NONDIR);
>+			}
>+		}
>+		break;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int au_opt_xino(struct super_block *sb, struct au_opt *opt,
>+		       struct au_opt_xino **opt_xino, struct au_opts *opts)
>+{
>+	int err;
>+
>+	AuTraceEnter();
>+
>+	err = 0;
>+	switch (opt->type) {
>+	case Opt_xino:
>+		err = au_xino_set(sb, &opt->xino,
>+				  au_ftest_opts(opts->flags, REMOUNT));
>+		if (!err)
>+			*opt_xino = &opt->xino;
>+		break;
>+	case Opt_noxino:
>+		au_xino_clr(sb);
>+		*opt_xino = (void *)-1;
>+		break;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static noinline_for_stack int
>+verify_opts(struct super_block *sb, unsigned int pending, int remount)
>+{
>+	int err;
>+	aufs_bindex_t bindex, bend;
>+	struct au_branch *br;
>+	struct dentry *root;
>+	struct inode *dir;
>+	unsigned int do_plink;
>+	unsigned int mnt_flags;
>+
>+	AuTraceEnter();
>+	mnt_flags = au_mntflags(sb);
>+	AuDebugOn(!(mnt_flags & AuOptMask_COO));
>+	AuDebugOn(!(mnt_flags & AuOptMask_UDBA));
>+
>+	if (!(sb->s_flags & MS_RDONLY)) {
>+		if (unlikely(!au_br_writable(au_sbr_perm(sb, 0))))
>+			AuWarn("first branch should be rw\n");
>+		if (unlikely(au_opt_test(mnt_flags, SHWH)))
>+			AuWarn("shwh should be used with ro\n");
>+	}
>+
>+	if (unlikely(au_opt_test(mnt_flags | pending, UDBA_INOTIFY)
>+		     && !au_opt_test(mnt_flags, XINO)))
>+		AuWarn("udba=inotify requires xino\n");
>+
>+	err = 0;
>+	root = sb->s_root;
>+	dir = sb->s_root->d_inode;
>+	do_plink = !!au_opt_test(mnt_flags, PLINK);
>+	bend = au_sbend(sb);
>+	for (bindex = 0; !err && bindex <= bend; bindex++) {
>+		struct inode *h_dir;
>+		int skip;
>+
>+		skip = 0;
>+		h_dir = au_h_iptr(dir, bindex);
>+		br = au_sbr(sb, bindex);
>+		br_wh_read_lock(br);
>+		switch (br->br_perm) {
>+		case AuBr_RR:
>+		case AuBr_RO:
>+		case AuBr_RRWH:
>+		case AuBr_ROWH:
>+			skip = (!br->br_wh && !br->br_plink);
>+			break;
>+
>+		case AuBr_RWNoLinkWH:
>+			skip = !br->br_wh;
>+			if (skip) {
>+				if (do_plink)
>+					skip = !!br->br_plink;
>+				else
>+					skip = !br->br_plink;
>+			}
>+			break;
>+
>+		case AuBr_RW:
>+			skip = !!br->br_wh;
>+			if (skip) {
>+				if (do_plink)
>+					skip = !!br->br_plink;
>+				else
>+					skip = !br->br_plink;
>+			}
>+			break;
>+
>+		default:
>+			BUG();
>+		}
>+		br_wh_read_unlock(br);
>+
>+		if (skip)
>+			continue;
>+
>+		au_hdir_lock(h_dir, dir, bindex);
>+		br_wh_write_lock(br);
>+		err = au_wh_init(au_h_dptr(root, bindex), br,
>+				 au_nfsmnt(sb, bindex), sb);
>+		br_wh_write_unlock(br);
>+		au_hdir_unlock(h_dir, dir, bindex);
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_opts_mount(struct super_block *sb, struct au_opts *opts)
>+{
>+	int err;
>+	struct inode *dir;
>+	struct au_opt *opt;
>+	struct au_opt_xino *opt_xino;
>+	aufs_bindex_t bend;
>+	struct au_sbinfo *sbinfo;
>+	unsigned int tmp;
>+
>+	AuTraceEnter();
>+	SiMustWriteLock(sb);
>+	DiMustWriteLock(sb->s_root);
>+	dir = sb->s_root->d_inode;
>+	IiMustWriteLock(dir);
>+
>+	err = 0;
>+	opt_xino = NULL;
>+	opt = opts->opt;
>+	while (err >= 0 && opt->type != Opt_tail)
>+		err = au_opt_simple(sb, opt++, opts);
>+	if (err > 0)
>+		err = 0;
>+	else if (unlikely(err < 0))
>+		goto out;
>+
>+	/* disable xino, hinotify, dlgt temporary */
>+	sbinfo = au_sbi(sb);
>+	tmp = sbinfo->si_mntflags;
>+	au_opt_clr(sbinfo->si_mntflags, XINO);
>+	au_opt_clr(sbinfo->si_mntflags, DLGT);
>+	au_opt_set_udba(sbinfo->si_mntflags, UDBA_REVAL);
>+
>+	opt = opts->opt;
>+	while (err >= 0 && opt->type != Opt_tail)
>+		err = au_opt_br(sb, opt++, opts);
>+	if (err > 0)
>+		err = 0;
>+	else if (unlikely(err < 0))
>+		goto out;
>+
>+	bend = au_sbend(sb);
>+	if (unlikely(bend < 0)) {
>+		err = -EINVAL;
>+		AuErr("no branches\n");
>+		goto out;
>+	}
>+
>+	if (au_opt_test(tmp, XINO))
>+		au_opt_set(sbinfo->si_mntflags, XINO);
>+	opt = opts->opt;
>+	while (!err && opt->type != Opt_tail)
>+		err = au_opt_xino(sb, opt++, &opt_xino, opts);
>+	if (unlikely(err))
>+		goto out;
>+
>+	//todo: test this error case.
>+	err = verify_opts(sb, tmp, /*remount*/0);
>+	if (unlikely(err))
>+		goto out;
>+
>+	/* enable xino */
>+	if (au_opt_test(tmp, XINO) && !opt_xino) {
>+		struct au_opt_xino xino;
>+
>+		xino.file = au_xino_def(sb);
>+		err = PTR_ERR(xino.file);
>+		if (IS_ERR(xino.file))
>+			goto out;
>+
>+		err = au_xino_set(sb, &xino, /*remount*/0);
>+		fput(xino.file);
>+		if (unlikely(err))
>+			goto out;
>+	}
>+
>+	/* restore hinotify */
>+	sbinfo->si_mntflags &= ~AuOptMask_UDBA;
>+	sbinfo->si_mntflags |= (tmp & AuOptMask_UDBA);
>+	if (au_opt_test(tmp, UDBA_INOTIFY))
>+		au_reset_hinotify(dir, au_hi_flags(dir, 1) & ~AuHi_XINO);
>+
>+	/* restore dlgt */
>+	if (au_opt_test_dlgt(tmp))
>+		au_opt_set(sbinfo->si_mntflags, DLGT);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_opts_remount(struct super_block *sb, struct au_opts *opts)
>+{
>+	int err, rerr;
>+	struct inode *dir;
>+	struct au_opt_xino *opt_xino;
>+	struct au_opt *opt;
>+	unsigned int dlgt;
>+	struct au_sbinfo *sbinfo;
>+
>+	AuTraceEnter();
>+	SiMustWriteLock(sb);
>+	DiMustWriteLock(sb->s_root);
>+	dir = sb->s_root->d_inode;
>+	IiMustWriteLock(dir);
>+	sbinfo = au_sbi(sb);
>+	//AuDebugOn(au_opt_test(sbifno->si_mntflags, UDBA_INOTIFY));
>+
>+	err = 0;
>+	dlgt = !!au_opt_test_dlgt(sbinfo->si_mntflags);
>+	opt_xino = NULL;
>+	opt = opts->opt;
>+	while (err >= 0 && opt->type != Opt_tail) {
>+		err = au_opt_simple(sb, opt, opts);
>+
>+		/* disable it temporary */
>+		dlgt = !!au_opt_test_dlgt(sbinfo->si_mntflags);
>+		au_opt_clr(sbinfo->si_mntflags, DLGT);
>+
>+		if (!err)
>+			err = au_opt_br(sb, opt, opts);
>+		if (!err)
>+			err = au_opt_xino(sb, opt, &opt_xino, opts);
>+
>+		/* restore it */
>+		if (unlikely(dlgt))
>+			au_opt_set(sbinfo->si_mntflags, DLGT);
>+		opt++;
>+	}
>+	if (err > 0)
>+		err = 0;
>+	AuTraceErr(err);
>+
>+	/* go on even err */
>+
>+	//todo: test this error case.
>+	au_opt_clr(sbinfo->si_mntflags, DLGT);
>+	rerr = verify_opts(sb, sbinfo->si_mntflags, /*remount*/1);
>+	if (unlikely(dlgt))
>+		au_opt_set(sbinfo->si_mntflags, DLGT);
>+	if (unlikely(rerr && !err))
>+		err = rerr;
>+
>+	if (unlikely(au_ftest_opts(opts->flags, TRUNC_XIB))) {
>+		rerr = au_xib_trunc(sb);
>+		if (unlikely(rerr && !err))
>+			err = rerr;
>+	}
>+
>+	/* they are handled by the caller */
>+	if (!au_ftest_opts(opts->flags, REFRESH_DIR)
>+	    && (opts->given_udba || au_opt_test(sbinfo->si_mntflags, XINO)))
>+		au_fset_opts(opts->flags, REFRESH_DIR);
>+
>+	LKTRTrace("status 0x%x\n", opts->flags);
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/opts.h linux-2.6.25.4-unionfs/fs/aufs/opts.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/opts.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/opts.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,245 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * mount options/flags
>+ *
>+ * $Id: opts.h,v 1.2 2008/04/21 01:46:26 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_OPTS_H__
>+#define __AUFS_OPTS_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/namei.h>
>+#include <linux/aufs_type.h>
>+#include "wkq.h"
>+
>+/* ---------------------------------------------------------------------- */
>+/* mount flags */
>+
>+/* external inode number bitmap and translation table */
>+#define AuOpt_XINO		1
>+#define AuOpt_TRUNC_XINO	(1 << 1)
>+#define AuOpt_LINO		(1 << 2)
>+#define AuOpt_UDBA_NONE		(1 << 3)	/* users direct branch access */
>+#define AuOpt_UDBA_REVAL	(1 << 4)
>+#define AuOpt_UDBA_INOTIFY	(1 << 5)
>+#define AuOpt_SHWH		(1 << 6)
>+#define AuOpt_PLINK		(1 << 7)
>+#define AuOpt_WARN_PERM		(1 << 8)
>+#define AuOpt_DIRPERM1		(1 << 9)
>+#define AuOpt_DLGT		(1 << 10)
>+#define AuOpt_COO_NONE		(1 << 11)	/* copyup on open */
>+#define AuOpt_COO_LEAF		(1 << 12)
>+#define AuOpt_COO_ALL		(1 << 13)
>+#define AuOpt_ALWAYS_DIROPQ	(1 << 14)
>+#define AuOpt_REFROF		(1 << 15)
>+#define AuOpt_VERBOSE		(1 << 16)
>+#ifndef CONFIG_AUFS_HINOTIFY
>+#undef AuOpt_UDBA_INOTIFY
>+#define AuOpt_UDBA_INOTIFY	0
>+#endif
>+#ifndef CONFIG_AUFS_SHWH
>+#undef AuOpt_SHWH
>+#define AuOpt_SHWH		0
>+#endif
>+#ifndef CONFIG_AUFS_DLGT
>+#undef AuOpt_DIRPERM1
>+#define AuOpt_DIRPERM1		0
>+#undef AuOpt_DLGT
>+#define AuOpt_DLGT		0
>+#endif
>+
>+/* policies to select one among multiple writable branches */
>+enum {
>+	AuWbrCreate_TDP,	/* top down parent */
>+	AuWbrCreate_RR,		/* round robin */
>+	AuWbrCreate_MFS,	/* most free space */
>+	AuWbrCreate_MFSV,	/* mfs with seconds */
>+	AuWbrCreate_MFSRR,	/* mfs then rr */
>+	AuWbrCreate_MFSRRV,	/* mfs then rr with seconds */
>+	AuWbrCreate_PMFS,	/* parent and mfs */
>+	AuWbrCreate_PMFSV,	/* parent and mfs with seconds */
>+
>+	AuWbrCreate_Def = AuWbrCreate_TDP
>+};
>+
>+enum {
>+	AuWbrCopyup_TDP,	/* top down parent */
>+	AuWbrCopyup_BUP,	/* bottom up parent */
>+	AuWbrCopyup_BU,		/* bottom up */
>+
>+	AuWbrCopyup_Def = AuWbrCopyup_TDP
>+};
>+
>+#define AuOptMask_COO		(AuOpt_COO_NONE \
>+				 | AuOpt_COO_LEAF \
>+				 | AuOpt_COO_ALL)
>+#define AuOptMask_UDBA		(AuOpt_UDBA_NONE \
>+				 | AuOpt_UDBA_REVAL \
>+				 | AuOpt_UDBA_INOTIFY)
>+
>+#ifdef CONFIG_AUFS_COMPAT
>+#define AuOpt_DefExtra1	AuOpt_ALWAYS_DIROPQ
>+#else
>+#define AuOpt_DefExtra1	0
>+#endif
>+
>+#define AuOpt_Def	(AuOpt_XINO \
>+			 | AuOpt_UDBA_REVAL \
>+			 | AuOpt_WARN_PERM \
>+			 | AuOpt_COO_NONE \
>+			 | AuOpt_PLINK \
>+			 | AuOpt_DefExtra1)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_opt_add {
>+	aufs_bindex_t		bindex;
>+	char			*path;
>+	int			perm;
>+	struct nameidata	nd;
>+};
>+
>+struct au_opt_del {
>+	char		*path;
>+	struct dentry	*h_root;
>+};
>+
>+struct au_opt_mod {
>+	char		*path;
>+	int		perm;
>+	struct dentry	*h_root;
>+};
>+
>+struct au_opt_xino {
>+	char		*path;
>+	struct file	*file;
>+};
>+
>+struct au_opt_xino_itrunc {
>+	aufs_bindex_t	bindex;
>+};
>+
>+struct au_opt_xino_trunc_v {
>+	u64		upper;
>+	int		step;
>+};
>+
>+struct au_opt_wbr_create {
>+	int wbr_create;
>+	int mfs_second;
>+	u64 mfsrr_watermark;
>+};
>+
>+struct au_opt {
>+	int type;
>+	union {
>+		struct au_opt_xino	xino;
>+		struct au_opt_xino_itrunc xino_itrunc;
>+		struct au_opt_add	add;
>+		struct au_opt_del	del;
>+		struct au_opt_mod	mod;
>+		int			dirwh;
>+		int			rdcache;
>+		int			deblk;
>+		int			nhash;
>+		int			udba;
>+		int			coo;
>+		struct au_opt_wbr_create wbr_create;
>+		int			wbr_copyup;
>+	};
>+};
>+
>+/* opts flags */
>+#define AuOpts_REMOUNT		1
>+#define AuOpts_REFRESH_DIR	(1 << 1)
>+#define AuOpts_REFRESH_NONDIR	(1 << 2)
>+#define AuOpts_TRUNC_XIB	(1 << 3)
>+#define au_ftest_opts(flags, name)	((flags) & AuOpts_##name)
>+#define au_fset_opts(flags, name)	{ (flags) |= AuOpts_##name; }
>+#define au_fclr_opts(flags, name)	{ (flags) &= ~AuOpts_##name; }
>+
>+struct au_opts {
>+	struct au_opt	*opt;
>+	int		max_opt;
>+
>+	unsigned int	given_udba;
>+	unsigned int	flags;
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+const char *au_optstr_br_perm(int brperm);
>+const char *au_optstr_udba(int udba);
>+const char *au_optstr_coo(int coo);
>+const char *au_optstr_wbr_copyup(int wbr_copyup);
>+const char *au_optstr_wbr_create(int wbr_create);
>+
>+void au_opts_free(struct au_opts *opts);
>+int au_opts_parse(struct super_block *sb, unsigned long flags, char *str,
>+		  struct au_opts *opts);
>+int au_opts_mount(struct super_block *sb, struct au_opts *opts);
>+int au_opts_remount(struct super_block *sb, struct au_opts *opts);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline unsigned int au_opt_do_test(unsigned int flags, unsigned int bit)
>+{
>+	AuDebugOn(bit & (AuOpt_DLGT | AuOpt_DIRPERM1));
>+	return (flags & bit);
>+}
>+
>+#define au_opt_test(flags, name)	au_opt_do_test(flags, AuOpt_##name)
>+
>+#define au_opt_set(flags, name) do { \
>+	BUILD_BUG_ON(AuOpt_##name & (AuOptMask_COO | AuOptMask_UDBA)); \
>+	((flags) |= AuOpt_##name); \
>+} while (0)
>+
>+#define au_opt_clr(flags, name)		{ ((flags) &= ~AuOpt_##name); }
>+
>+#define au_opt_set_coo(flags, name) do { \
>+	(flags) &= ~AuOptMask_COO; \
>+	((flags) |= AuOpt_##name); \
>+} while(0)
>+
>+#define au_opt_set_udba(flags, name) do { \
>+	(flags) &= ~AuOptMask_UDBA; \
>+	((flags) |= AuOpt_##name); \
>+} while(0)
>+
>+static inline unsigned int au_opt_test_dlgt(unsigned int flags)
>+{
>+	if (!au_test_wkq(current))
>+		return (flags & AuOpt_DLGT);
>+	return 0;
>+}
>+
>+static inline unsigned int au_opt_test_dirperm1(unsigned int flags)
>+{
>+	if (!au_test_wkq(current))
>+		return (flags & AuOpt_DIRPERM1);
>+	return 0;
>+}
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_OPTS_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/plink.c linux-2.6.25.4-unionfs/fs/aufs/plink.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/plink.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/plink.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,345 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * pseudo-link
>+ *
>+ * $Id: plink.c,v 1.2 2008/04/21 01:45:16 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+struct pseudo_link {
>+	struct list_head list;
>+	struct inode *inode;
>+};
>+
>+#ifdef CONFIG_AUFS_DEBUG
>+void au_plink_list(struct super_block *sb)
>+{
>+	struct au_sbinfo *sbinfo;
>+	struct list_head *plink_list;
>+	struct pseudo_link *plink;
>+
>+	AuTraceEnter();
>+	SiMustAnyLock(sb);
>+	sbinfo = au_sbi(sb);
>+	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
>+
>+	plink_list = &sbinfo->si_plink;
>+	spin_lock(&sbinfo->si_plink_lock);
>+	list_for_each_entry(plink, plink_list, list)
>+		AuDbg("%lu\n", plink->inode->i_ino);
>+	spin_unlock(&sbinfo->si_plink_lock);
>+}
>+#endif
>+
>+int au_plink_test(struct super_block *sb, struct inode *inode)
>+{
>+	int found;
>+	struct au_sbinfo *sbinfo;
>+	struct list_head *plink_list;
>+	struct pseudo_link *plink;
>+
>+	LKTRTrace("i%lu\n", inode->i_ino);
>+	SiMustAnyLock(sb);
>+	sbinfo = au_sbi(sb);
>+	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
>+
>+	found = 0;
>+	plink_list = &sbinfo->si_plink;
>+	spin_lock(&sbinfo->si_plink_lock);
>+	list_for_each_entry(plink, plink_list, list)
>+		if (plink->inode == inode) {
>+			found = 1;
>+			break;
>+		}
>+	spin_unlock(&sbinfo->si_plink_lock);
>+	return found;
>+}
>+
>+/* 20 is max digits length of ulong 64 */
>+#define PLINK_NAME_LEN	((20 + 1) * 2)
>+
>+static int plink_name(char *name, int len, struct inode *inode,
>+		      aufs_bindex_t bindex)
>+{
>+	int rlen;
>+	struct inode *h_inode;
>+
>+	LKTRTrace("i%lu, b%d\n", inode->i_ino, bindex);
>+	AuDebugOn(len != PLINK_NAME_LEN);
>+	h_inode = au_h_iptr(inode, bindex);
>+	AuDebugOn(!h_inode);
>+	rlen = snprintf(name, len, "%lu.%lu", inode->i_ino, h_inode->i_ino);
>+	AuDebugOn(rlen >= len);
>+	return rlen;
>+}
>+
>+struct dentry *au_plink_lkup(struct super_block *sb, aufs_bindex_t bindex,
>+			     struct inode *inode)
>+{
>+	struct dentry *h_dentry, *h_parent;
>+	struct au_branch *br;
>+	struct inode *h_dir;
>+	char tgtname[PLINK_NAME_LEN];
>+	int len;
>+	struct au_ndx ndx = {
>+		.flags	= 0,
>+		.nd	= NULL,
>+		//.br	= NULL
>+	};
>+
>+	LKTRTrace("b%d, i%lu\n", bindex, inode->i_ino);
>+	br = au_sbr(sb, bindex);
>+	h_parent = br->br_plink;
>+	AuDebugOn(!h_parent);
>+	h_dir = h_parent->d_inode;
>+	AuDebugOn(!h_dir);
>+
>+	len = plink_name(tgtname, sizeof(tgtname), inode, bindex);
>+
>+	/* always superio. */
>+	ndx.nfsmnt = au_do_nfsmnt(br->br_mnt);
>+	mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_CHILD2);
>+	h_dentry = au_sio_lkup_one(tgtname, h_parent, len, &ndx);
>+	mutex_unlock(&h_dir->i_mutex);
>+	return h_dentry;
>+}
>+
>+static int do_whplink(char *tgt, int len, struct dentry *h_parent,
>+		      struct dentry *h_dentry, struct vfsmount *nfsmnt,
>+		      struct super_block *sb)
>+{
>+	int err, dlgt;
>+	struct dentry *h_tgt;
>+	struct inode *h_dir;
>+	struct vfsub_args vargs;
>+	struct au_ndx ndx = {
>+		.nfsmnt	= nfsmnt,
>+		.flags	= 0,
>+		.nd	= NULL,
>+		//.br	= NULL
>+	};
>+
>+	dlgt = !!au_opt_test_dlgt(au_mntflags(sb));
>+	if (unlikely(dlgt))
>+		au_fset_ndx(ndx.flags, DLGT);
>+	h_tgt = au_lkup_one(tgt, h_parent, len, &ndx);
>+	err = PTR_ERR(h_tgt);
>+	if (IS_ERR(h_tgt))
>+		goto out;
>+
>+	err = 0;
>+	vfsub_args_init(&vargs, NULL, dlgt, 0);
>+	h_dir = h_parent->d_inode;
>+	if (unlikely(h_tgt->d_inode && h_tgt->d_inode != h_dentry->d_inode))
>+		err = vfsub_unlink(h_dir, h_tgt, &vargs);
>+	if (!err && !h_tgt->d_inode) {
>+		err = vfsub_link(h_dentry, h_dir, h_tgt, dlgt);
>+		//inode->i_nlink++;
>+	}
>+	dput(h_tgt);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+struct do_whplink_args {
>+	int *errp;
>+	char *tgt;
>+	int len;
>+	struct dentry *h_parent;
>+	struct dentry *h_dentry;
>+	struct vfsmount *nfsmnt;
>+	struct super_block *sb;
>+};
>+
>+static void call_do_whplink(void *args)
>+{
>+	struct do_whplink_args *a = args;
>+	*a->errp = do_whplink(a->tgt, a->len, a->h_parent, a->h_dentry,
>+			      a->nfsmnt, a->sb);
>+}
>+
>+static int whplink(struct dentry *h_dentry, struct inode *inode,
>+		   aufs_bindex_t bindex, struct super_block *sb)
>+{
>+	int err, len, wkq_err;
>+	struct au_branch *br;
>+	struct dentry *h_parent;
>+	struct inode *h_dir;
>+	char tgtname[PLINK_NAME_LEN];
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(h_dentry));
>+	br = au_sbr(inode->i_sb, bindex);
>+	h_parent = br->br_plink;
>+	AuDebugOn(!h_parent);
>+	h_dir = h_parent->d_inode;
>+	AuDebugOn(!h_dir);
>+
>+	len = plink_name(tgtname, sizeof(tgtname), inode, bindex);
>+
>+	/* always superio. */
>+	mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_CHILD2);
>+	if (!au_test_wkq(current)) {
>+		struct do_whplink_args args = {
>+			.errp		= &err,
>+			.tgt		= tgtname,
>+			.len		= len,
>+			.h_parent	= h_parent,
>+			.h_dentry	= h_dentry,
>+			.nfsmnt		= au_do_nfsmnt(br->br_mnt),
>+			.sb		= sb
>+		};
>+		wkq_err = au_wkq_wait(call_do_whplink, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	} else
>+		err = do_whplink(tgtname, len, h_parent, h_dentry,
>+				 au_do_nfsmnt(br->br_mnt), sb);
>+	mutex_unlock(&h_dir->i_mutex);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+void au_plink_append(struct super_block *sb, struct inode *inode,
>+		     struct dentry *h_dentry, aufs_bindex_t bindex)
>+{
>+	struct au_sbinfo *sbinfo;
>+	struct list_head *plink_list;
>+	struct pseudo_link *plink;
>+	int found, err, cnt;
>+
>+	LKTRTrace("i%lu\n", inode->i_ino);
>+	SiMustAnyLock(sb);
>+	sbinfo = au_sbi(sb);
>+	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
>+
>+	cnt = 0;
>+	found = 0;
>+	plink_list = &sbinfo->si_plink;
>+	spin_lock(&sbinfo->si_plink_lock);
>+	list_for_each_entry(plink, plink_list, list) {
>+		cnt++;
>+		if (plink->inode == inode) {
>+			found = 1;
>+			break;
>+		}
>+	}
>+
>+	err = 0;
>+	if (!found) {
>+		plink = kmalloc(sizeof(*plink), GFP_ATOMIC);
>+		if (plink) {
>+			plink->inode = igrab(inode);
>+			list_add(&plink->list, plink_list);
>+			cnt++;
>+		} else
>+			err = -ENOMEM;
>+	}
>+	spin_unlock(&sbinfo->si_plink_lock);
>+
>+	if (!err)
>+		err = whplink(h_dentry, inode, bindex, sb);
>+
>+	if (unlikely(cnt > AUFS_PLINK_WARN))
>+		AuWarn1("unexpectedly many pseudo links, %d\n", cnt);
>+	if (unlikely(err))
>+		AuWarn("err %d, damaged pseudo link. ignored.\n", err);
>+}
>+
>+static void do_put_plink(struct pseudo_link *plink, int do_del)
>+{
>+	AuTraceEnter();
>+
>+	iput(plink->inode);
>+	if (do_del)
>+		list_del(&plink->list);
>+	kfree(plink);
>+}
>+
>+void au_plink_put(struct super_block *sb)
>+{
>+	struct au_sbinfo *sbinfo;
>+	struct list_head *plink_list;
>+	struct pseudo_link *plink, *tmp;
>+
>+	AuTraceEnter();
>+	SiMustWriteLock(sb);
>+	sbinfo = au_sbi(sb);
>+	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
>+
>+	plink_list = &sbinfo->si_plink;
>+	//spin_lock(&sbinfo->si_plink_lock);
>+	list_for_each_entry_safe(plink, tmp, plink_list, list)
>+		do_put_plink(plink, 0);
>+	INIT_LIST_HEAD(plink_list);
>+	//spin_unlock(&sbinfo->si_plink_lock);
>+}
>+
>+void au_plink_half_refresh(struct super_block *sb, aufs_bindex_t br_id)
>+{
>+	struct au_sbinfo *sbinfo;
>+	struct list_head *plink_list;
>+	struct pseudo_link *plink, *tmp;
>+	struct inode *inode;
>+	aufs_bindex_t bstart, bend, bindex;
>+	int do_put;
>+
>+	AuTraceEnter();
>+	SiMustWriteLock(sb);
>+	sbinfo = au_sbi(sb);
>+	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
>+
>+	plink_list = &sbinfo->si_plink;
>+	//spin_lock(&sbinfo->si_plink_lock);
>+	list_for_each_entry_safe(plink, tmp, plink_list, list) {
>+		do_put = 0;
>+		inode = igrab(plink->inode);
>+		ii_write_lock_child(inode);
>+		bstart = au_ibstart(inode);
>+		bend = au_ibend(inode);
>+		if (bstart >= 0) {
>+			for (bindex = bstart; bindex <= bend; bindex++) {
>+				if (!au_h_iptr(inode, bindex)
>+				    || au_ii_br_id(inode, bindex) != br_id)
>+					continue;
>+				au_set_h_iptr(inode, bindex, NULL, 0);
>+				do_put = 1;
>+				break;
>+			}
>+		} else
>+			do_put_plink(plink, 1);
>+
>+		if (do_put) {
>+			for (bindex = bstart; bindex <= bend; bindex++)
>+				if (au_h_iptr(inode, bindex)) {
>+					do_put = 0;
>+					break;
>+				}
>+			if (do_put)
>+				do_put_plink(plink, 1);
>+		}
>+		ii_write_unlock(inode);
>+		iput(inode);
>+	}
>+	//spin_unlock(&sbinfo->si_plink_lock);
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/robr.c linux-2.6.25.4-unionfs/fs/aufs/robr.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/robr.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/robr.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,111 @@
>+/*
>+ * Copyright (C) 2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * 'robr', aufs as readonly branch of another aufs
>+ *
>+ * $Id: robr.c,v 1.3 2008/05/19 01:48:04 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int au_test_robr_wh(struct qstr *name, struct dentry *h_parent,
>+		    struct qstr *wh_name, int try_sio, struct au_ndx *ndx)
>+{
>+	if (strncmp(name->name, AUFS_WH_PFX, AUFS_WH_PFX_LEN))
>+		return au_wh_test(h_parent, wh_name, try_sio, ndx);
>+	return -EPERM;
>+}
>+
>+int au_test_robr_shwh(struct super_block *sb, const struct qstr *name)
>+{
>+	return 0;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_robr_lvma {
>+	struct list_head list;
>+	struct vm_area_struct *vma;
>+};
>+
>+struct file *au_robr_safe_file(struct vm_area_struct *vma)
>+{
>+	struct file *file = vma->vm_file;
>+	struct super_block *sb = file->f_dentry->d_sb;
>+	struct au_robr_lvma *lvma, *entry;
>+	struct au_sbinfo *sbinfo;
>+	int found, warn;
>+
>+	AuTraceEnter();
>+	AuDebugOn(!au_test_aufs(sb));
>+
>+	warn = 0;
>+	found = 0;
>+	sbinfo = au_sbi(sb);
>+	spin_lock(&sbinfo->si_lvma_lock);
>+	list_for_each_entry(entry, &sbinfo->si_lvma, list) {
>+		found = (entry->vma == vma);
>+		if (unlikely(found))
>+			break;
>+	}
>+	if (!found) {
>+		lvma = kmalloc(sizeof(*lvma), GFP_ATOMIC);
>+		if (lvma) {
>+			lvma->vma = vma;
>+			list_add(&lvma->list, &sbinfo->si_lvma);
>+		} else {
>+			warn = 1;
>+			file = NULL;
>+		}
>+	} else
>+		file = NULL;
>+	spin_unlock(&sbinfo->si_lvma_lock);
>+
>+	if (unlikely(warn))
>+		AuWarn1("no memory for lvma\n");
>+	return file;
>+}
>+
>+void au_robr_reset_file(struct vm_area_struct *vma, struct file *file)
>+{
>+	struct super_block *sb = file->f_dentry->d_sb;
>+	struct au_robr_lvma *entry, *found;
>+	struct au_sbinfo *sbinfo;
>+
>+	AuTraceEnter();
>+	AuDebugOn(!au_test_aufs(sb));
>+
>+	vma->vm_file = file;
>+	//smp_mb(); /* flush vm_file */
>+
>+	found = NULL;
>+	sbinfo = au_sbi(sb);
>+	spin_lock(&sbinfo->si_lvma_lock);
>+	list_for_each_entry(entry, &sbinfo->si_lvma, list)
>+		if (entry->vma == vma) {
>+			found = entry;
>+			break;
>+		}
>+	AuDebugOn(!found);
>+	list_del(&found->list);
>+	spin_unlock(&sbinfo->si_lvma_lock);
>+	kfree(found);
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/sbinfo.c linux-2.6.25.4-unionfs/fs/aufs/sbinfo.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/sbinfo.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/sbinfo.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,268 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * superblock private data
>+ *
>+ * $Id: sbinfo.c,v 1.5 2008/05/19 01:49:56 sfjro Exp $
>+ */
>+
>+#include <linux/mnt_namespace.h>
>+#include <linux/smp_lock.h>
>+#include "aufs.h"
>+
>+/*
>+ * they are necessary regardless sysfs is disabled.
>+ */
>+void au_si_free(struct kobject *kobj)
>+{
>+	struct au_sbinfo *sbinfo;
>+	struct super_block *sb;
>+
>+	LKTRTrace("kobj %p\n", kobj);
>+	sbinfo = container_of(kobj, struct au_sbinfo, si_kobj);
>+	LKTRTrace("sbinfo %p\n", sbinfo);
>+	AuDebugOn(!list_empty(&sbinfo->si_plink));
>+
>+	sb = sbinfo->si_sb;
>+	if (unlikely(!au_ftest_si(sbinfo, FAILED_INIT))) {
>+		au_sbilist_lock();
>+		au_sbilist_del(sbinfo);
>+		au_sbilist_unlock();
>+	}
>+
>+	si_write_lock(sb);
>+	au_xino_clr(sb);
>+	au_br_free(sbinfo);
>+	kfree(sbinfo->si_branch);
>+	si_write_unlock(sb);
>+
>+	//AuDbg("free\n");
>+ 	kfree(sbinfo);
>+}
>+
>+int au_si_alloc(struct super_block *sb)
>+{
>+	int err;
>+	struct au_sbinfo *sbinfo;
>+
>+	AuTraceEnter();
>+
>+	err = -ENOMEM;
>+	sbinfo = kmalloc(sizeof(*sbinfo), GFP_KERNEL);
>+	//if (LktrCond) {kfree(sbinfo); sbinfo = NULL;}
>+	if (unlikely(!sbinfo))
>+		goto out;
>+	sbinfo->si_branch = kzalloc(sizeof(*sbinfo->si_branch), GFP_KERNEL);
>+	//if (LktrCond) {kfree(sbinfo->si_branch); sbinfo->si_branch = NULL;}
>+	if (unlikely(!sbinfo->si_branch))
>+		goto out_sbinfo;
>+
>+	memset(&sbinfo->si_kobj, 0, sizeof(sbinfo->si_kobj));
>+	err = sysaufs_si_init(sbinfo);
>+	if (unlikely(err))
>+		goto out_br;
>+
>+	au_rw_init_wlock(&sbinfo->si_rwsem);
>+	sbinfo->si_generation = 0;
>+	//sbinfo->si_generation = INT_MAX - 2;
>+	sbinfo->au_si_status = 0;
>+	sbinfo->si_bend = -1;
>+	sbinfo->si_last_br_id = 0;
>+
>+	sbinfo->si_wbr_copyup = AuWbrCopyup_Def;
>+	sbinfo->si_wbr_create = AuWbrCreate_Def;
>+	sbinfo->si_wbr_copyup_ops = au_wbr_copyup_ops + AuWbrCopyup_Def;
>+	sbinfo->si_wbr_create_ops = au_wbr_create_ops + AuWbrCreate_Def;
>+
>+	sbinfo->si_mntflags = AuOpt_Def;
>+
>+	sbinfo->si_xread = NULL;
>+	sbinfo->si_xwrite = NULL;
>+	sbinfo->si_xib = NULL;
>+	mutex_init(&sbinfo->si_xib_mtx);
>+	sbinfo->si_xib_buf = NULL;
>+	/* leave si_xib_last_pindex and si_xib_next_bit */
>+
>+	au_nwt_init(&sbinfo->si_nowait);
>+
>+	sbinfo->si_rdcache = AUFS_RDCACHE_DEF * HZ;
>+	sbinfo->si_dirwh = AUFS_DIRWH_DEF;
>+
>+	spin_lock_init(&sbinfo->si_plink_lock);
>+	INIT_LIST_HEAD(&sbinfo->si_plink);
>+
>+	au_robr_lvma_init(sbinfo);
>+
>+	/* leave other members for sysaufs and si_mnt. */
>+	sbinfo->si_sb = sb;
>+
>+	sb->s_fs_info = sbinfo;
>+	//sysaufs_si_get(sb);
>+
>+	au_debug_sbinfo_init(sbinfo);
>+	return 0; /* success */
>+
>+ out_br:
>+	kfree(sbinfo->si_branch);
>+ out_sbinfo:
>+	kfree(sbinfo);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_branch *au_sbr(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	struct au_branch *br;
>+
>+	SiMustAnyLock(sb);
>+	AuDebugOn(bindex < 0 || au_sbend(sb) < bindex);
>+	br = au_sbi(sb)->si_branch[0 + bindex];
>+	AuDebugOn(!br);
>+	return br;
>+}
>+
>+au_gen_t au_sigen_inc(struct super_block *sb)
>+{
>+	au_gen_t gen;
>+
>+	SiMustWriteLock(sb);
>+	gen = ++au_sbi(sb)->si_generation;
>+	au_update_digen(sb->s_root);
>+	au_update_iigen(sb->s_root->d_inode);
>+	sb->s_root->d_inode->i_version++;
>+	return gen;
>+}
>+
>+int au_find_bindex(struct super_block *sb, struct au_branch *br)
>+{
>+	aufs_bindex_t bindex, bend;
>+
>+	bend = au_sbend(sb);
>+	for (bindex = 0; bindex <= bend; bindex++)
>+		if (au_sbr(sb, bindex) == br)
>+			return bindex;
>+	return -1;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* dentry and super_block lock. call at entry point */
>+void aufs_read_lock(struct dentry *dentry, int flags)
>+{
>+	si_read_lock(dentry->d_sb, flags);
>+	if (au_ftest_lock(flags, DW))
>+		di_write_lock_child(dentry);
>+	else
>+		di_read_lock_child(dentry, flags);
>+}
>+
>+void aufs_read_unlock(struct dentry *dentry, int flags)
>+{
>+	if (au_ftest_lock(flags, DW))
>+		di_write_unlock(dentry);
>+	else
>+		di_read_unlock(dentry, flags);
>+	si_read_unlock(dentry->d_sb);
>+}
>+
>+void aufs_write_lock(struct dentry *dentry)
>+{
>+	si_write_lock(dentry->d_sb);
>+	di_write_lock_child(dentry);
>+}
>+
>+void aufs_write_unlock(struct dentry *dentry)
>+{
>+	di_write_unlock(dentry);
>+	si_write_unlock(dentry->d_sb);
>+}
>+
>+void aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int flags)
>+{
>+	AuDebugOn(d1 == d2 || d1->d_sb != d2->d_sb);
>+	si_read_lock(d1->d_sb, flags);
>+	di_write_lock2_child(d1, d2, au_ftest_lock(flags, DIR));
>+}
>+
>+void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2)
>+{
>+	AuDebugOn(d1 == d2 || d1->d_sb != d2->d_sb);
>+	di_write_unlock2(d1, d2);
>+	si_read_unlock(d1->d_sb);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+aufs_bindex_t au_new_br_id(struct super_block *sb)
>+{
>+	aufs_bindex_t br_id;
>+	struct au_sbinfo *sbinfo;
>+
>+	AuTraceEnter();
>+	SiMustWriteLock(sb);
>+
>+	sbinfo = au_sbi(sb);
>+	while (1) {
>+		br_id = ++sbinfo->si_last_br_id;
>+		if (br_id && au_br_index(sb, br_id) < 0)
>+			return br_id;
>+	}
>+}
>+
>+//todo: dirty
>+/*
>+ * when you mntput() for the return value of this function,
>+ * you have to store it to your local var.
>+ * ie. never mntput si_mntcache directly.
>+ */
>+struct vfsmount *au_mntcache_get(struct super_block *sb)
>+{
>+	struct au_sbinfo *sbinfo;
>+	struct mnt_namespace *ns;
>+	struct vfsmount *pos, *mnt;
>+
>+	AuTraceEnter();
>+
>+	sbinfo = au_sbi(sb);
>+
>+	spin_lock(&sbinfo->si_mntcache_lock);
>+	if (sbinfo->si_mntcache)
>+		goto out;
>+
>+	/* vfsmount_lock is not exported */
>+	//root_mnt = current->fs->root.mnt;
>+	/* no get/put */
>+	AuDebugOn(!current->nsproxy);
>+	ns = current->nsproxy->mnt_ns;
>+	AuDebugOn(!ns);
>+	list_for_each_entry(pos, &ns->list, mnt_list)
>+		if (pos->mnt_sb == sb) {
>+			sbinfo->si_mntcache = pos;
>+			break;
>+		}
>+	AuDebugOn(!sbinfo->si_mntcache);
>+
>+ out:
>+	mnt = mntget(sbinfo->si_mntcache);
>+	spin_unlock(&sbinfo->si_mntcache_lock);
>+	return mnt;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/super.c linux-2.6.25.4-unionfs/fs/aufs/super.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/super.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/super.c	2008-05-25 12:00:53 +0300
>@@ -0,0 +1,877 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * mount and super_block operations
>+ *
>+ * $Id: super.c,v 1.6 2008/05/19 01:50:10 sfjro Exp $
>+ */
>+
>+#include <linux/module.h>
>+#include <linux/buffer_head.h>
>+#include <linux/seq_file.h>
>+#include <linux/smp_lock.h>
>+#include <linux/statfs.h>
>+
>+#include "aufs.h"
>+
>+/*
>+ * super_operations
>+ */
>+static struct inode *aufs_alloc_inode(struct super_block *sb)
>+{
>+	struct aufs_icntnr *c;
>+
>+	AuTraceEnter();
>+
>+	c = au_cache_alloc_icntnr();
>+	//if (LktrCond) {au_cache_free_icntnr(c); c = NULL;}
>+	if (c) {
>+		inode_init_once(&c->vfs_inode);
>+		c->vfs_inode.i_version = 1; //sigen(sb);
>+		c->iinfo.ii_hinode = NULL;
>+		return &c->vfs_inode;
>+	}
>+	return NULL;
>+}
>+
>+static void aufs_destroy_inode(struct inode *inode)
>+{
>+	LKTRTrace("i%lu\n", inode->i_ino);
>+	au_iinfo_fin(inode);
>+	au_cache_free_icntnr(container_of(inode, struct aufs_icntnr,
>+					  vfs_inode));
>+}
>+
>+struct inode *au_iget_locked(struct super_block *sb, ino_t ino)
>+{
>+	struct inode *inode;
>+	int err;
>+
>+	LKTRTrace("i%lu\n", ino);
>+
>+	inode = iget_locked(sb, ino);
>+	if (unlikely(!inode)) {
>+		inode = ERR_PTR(-ENOMEM);
>+		goto out;
>+	}
>+	AuDebugOn(IS_ERR(inode));
>+	if (unlikely(!(inode->i_state & I_NEW)))
>+		goto out;
>+
>+	err = au_iinfo_init(inode);
>+	//if (LktrCond) err = -1;
>+	if (!err) {
>+		inode->i_version++;
>+		inode->i_op = &aufs_iop;
>+		inode->i_fop = &aufs_file_fop;
>+		inode->i_mapping->a_ops = &aufs_aop;
>+		//inode->i_mapping->backing_dev_info = &bdi;
>+	} else {
>+		iget_failed(inode);
>+		inode = ERR_PTR(err);
>+	}
>+
>+ out:
>+	/* never return NULL */
>+	AuDebugOn(!inode);
>+	AuTraceErrPtr(inode);
>+	return inode;
>+}
>+
>+static int au_show_brs(struct seq_file *seq, struct super_block *sb)
>+{
>+	int err;
>+	aufs_bindex_t bindex, bend;
>+	struct dentry *root;
>+	struct path path;
>+
>+	AuTraceEnter();
>+
>+	err = 0;
>+	root = sb->s_root;
>+	bend = au_sbend(sb);
>+	for (bindex = 0; !err && bindex <= bend; bindex++) {
>+		path.mnt = au_sbr_mnt(sb, bindex);
>+		path.dentry = au_h_dptr(root, bindex);
>+		err = seq_path(seq, &path, au_esc_chars);
>+		if (err > 0)
>+			err = seq_printf
>+				(seq, "=%s",
>+				 au_optstr_br_perm(au_sbr_perm(sb, bindex)));
>+		if (!err && bindex != bend)
>+			err = seq_putc(seq, ':');
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static void au_show_wbr_create(struct seq_file *m, int v,
>+			       struct au_sbinfo *sbinfo)
>+{
>+	const char *pat;
>+
>+	AuDebugOn(v == AuWbrCreate_Def);
>+
>+	seq_printf(m, ",create=");
>+	pat = au_optstr_wbr_create(v);
>+	switch (v) {
>+	case AuWbrCreate_TDP:
>+	case AuWbrCreate_RR:
>+	case AuWbrCreate_MFS:
>+	case AuWbrCreate_PMFS:
>+		seq_printf(m, pat);
>+		break;
>+	case AuWbrCreate_MFSV:
>+		seq_printf(m, /*pat*/"mfs:%lu",
>+			   sbinfo->si_wbr_mfs.mfs_expire / HZ);
>+		break;
>+	case AuWbrCreate_PMFSV:
>+		seq_printf(m, /*pat*/"pmfs:%lu",
>+			   sbinfo->si_wbr_mfs.mfs_expire / HZ);
>+		break;
>+	case AuWbrCreate_MFSRR:
>+		seq_printf(m, /*pat*/"mfsrr:%Lu",
>+			   sbinfo->si_wbr_mfs.mfsrr_watermark);
>+		break;
>+	case AuWbrCreate_MFSRRV:
>+		seq_printf(m, /*pat*/"mfsrr:%Lu:%lu",
>+			   sbinfo->si_wbr_mfs.mfsrr_watermark,
>+			   sbinfo->si_wbr_mfs.mfs_expire / HZ);
>+		break;
>+	}
>+}
>+
>+/* seq_file will re-call me in case of too long string */
>+static int aufs_show_options(struct seq_file *m, struct vfsmount *mnt)
>+{
>+	int err, n;
>+	struct super_block *sb;
>+	struct au_sbinfo *sbinfo;
>+	struct dentry *root;
>+	struct file *xino;
>+	unsigned int mnt_flags, v;
>+	struct path path;
>+
>+	//au_debug_on();
>+	AuTraceEnter();
>+
>+	sb = mnt->mnt_sb;
>+	root = sb->s_root;
>+	if (!sysaufs_brs)
>+		aufs_read_lock(root, !AuLock_IR);
>+	else
>+		si_noflush_read_lock(sb);
>+	sbinfo = au_sbi(sb);
>+	seq_printf(m, ",si=%p", sbinfo);
>+	mnt_flags = au_mntflags(sb);
>+	if (au_opt_test(mnt_flags, XINO)) {
>+		seq_puts(m, ",xino=");
>+		xino = sbinfo->si_xib;
>+		path.mnt = xino->f_vfsmnt;
>+		path.dentry = xino->f_dentry;
>+		err = seq_path(m, &path, au_esc_chars);
>+		if (unlikely(err <= 0))
>+			goto out;
>+		err = 0;
>+#define Deleted "\\040(deleted)"
>+		m->count -= sizeof(Deleted) - 1;
>+		AuDebugOn(memcmp(m->buf + m->count, Deleted,
>+				 sizeof(Deleted) - 1));
>+#undef Deleted
>+	} else
>+		seq_puts(m, ",noxino");
>+
>+#define AuBool(name, str) do { \
>+	v = au_opt_test(mnt_flags, name); \
>+	if (v != au_opt_test(AuOpt_Def, name)) \
>+		seq_printf(m, ",%s" #str, v ? "" : "no"); \
>+} while (0)
>+
>+#define AuStr(name, str) do { \
>+	v = mnt_flags & AuOptMask_##name; \
>+	if (v != (AuOpt_Def & AuOptMask_##name)) \
>+		seq_printf(m, "," #str "=%s", au_optstr_##str(v)); \
>+} while (0)
>+
>+#ifdef CONFIG_AUFS_COMPAT
>+#define AuStr_BrOpt	"dirs="
>+#else
>+#define AuStr_BrOpt	"br:"
>+#endif
>+
>+	AuBool(TRUNC_XINO, trunc_xino);
>+	AuBool(DIRPERM1, dirperm1);
>+	AuBool(SHWH, shwh);
>+	AuBool(PLINK, plink);
>+	AuStr(UDBA, udba);
>+
>+	v = sbinfo->si_wbr_create;
>+	if (v != AuWbrCreate_Def)
>+		au_show_wbr_create(m, v, sbinfo);
>+
>+	v = sbinfo->si_wbr_copyup;
>+	if (v != AuWbrCopyup_Def)
>+		seq_printf(m, ",cpup=%s", au_optstr_wbr_copyup(v));
>+
>+	v = au_opt_test(mnt_flags, ALWAYS_DIROPQ);
>+	if (v != au_opt_test(AuOpt_Def, ALWAYS_DIROPQ))
>+		seq_printf(m, ",diropq=%c", v ? 'a' : 'w');
>+	AuBool(REFROF, refrof);
>+	AuBool(DLGT, dlgt);
>+	AuBool(WARN_PERM, warn_perm);
>+	AuBool(VERBOSE, verbose);
>+
>+	n = sbinfo->si_dirwh;
>+	if (n != AUFS_DIRWH_DEF)
>+		seq_printf(m, ",dirwh=%d", n);
>+	n = sbinfo->si_rdcache / HZ;
>+	if (n != AUFS_RDCACHE_DEF)
>+		seq_printf(m, ",rdcache=%d", n);
>+
>+	AuStr(COO, coo);
>+
>+ out:
>+	if (!sysaufs_brs) {
>+		seq_puts(m, "," AuStr_BrOpt);
>+		au_show_brs(m, sb);
>+		aufs_read_unlock(root, !AuLock_IR);
>+	} else
>+		si_read_unlock(sb);
>+	//au_debug_off();
>+	return 0;
>+
>+#undef AuBool
>+#undef AuStr
>+#undef AuStr_BrOpt
>+}
>+
>+static int aufs_statfs(struct dentry *dentry, struct kstatfs *buf)
>+{
>+	int err;
>+
>+	AuTraceEnter();
>+
>+	aufs_read_lock(dentry->d_sb->s_root, 0);
>+	err = vfsub_statfs(au_h_dptr(dentry->d_sb->s_root, 0), buf,
>+			   !!au_opt_test_dlgt(au_mntflags(dentry->d_sb)));
>+	//if (LktrCond) err = -1;
>+	aufs_read_unlock(dentry->d_sb->s_root, 0);
>+	if (!err) {
>+		buf->f_type = AUFS_SUPER_MAGIC;
>+		buf->f_namelen -= AUFS_WH_PFX_LEN;
>+		//todo: support uuid?
>+		memset(&buf->f_fsid, 0, sizeof(buf->f_fsid));
>+	}
>+	/* buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1; */
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static void au_fsync_br(struct super_block *sb)
>+{
>+#ifdef CONFIG_AUFS_FSYNC_SUPER_PATCH
>+	aufs_bindex_t bend, bindex;
>+	int brperm;
>+	struct super_block *h_sb;
>+
>+	AuTraceEnter();
>+
>+	si_write_lock(sb);
>+	bend = au_sbend(sb);
>+	for (bindex = 0; bindex < bend; bindex++) {
>+		brperm = au_sbr_perm(sb, bindex);
>+		if (brperm == AuBr_RR || brperm == AuBr_RRWH)
>+			continue;
>+		h_sb = au_sbr_sb(sb, bindex);
>+		if (bdev_read_only(h_sb->s_bdev))
>+			continue;
>+
>+		lockdep_off();
>+		down_write(&h_sb->s_umount);
>+		shrink_dcache_sb(h_sb);
>+		fsync_super(h_sb);
>+		up_write(&h_sb->s_umount);
>+		lockdep_on();
>+	}
>+	si_write_unlock(sb);
>+#endif
>+}
>+
>+static void aufs_umount_begin(struct vfsmount *mnt, int flags)
>+{
>+	struct super_block *sb = mnt->mnt_sb;
>+	struct au_sbinfo *sbinfo;
>+
>+	AuTraceEnter();
>+	//todo: dont trust BKL.
>+	AuDebugOn(!kernel_locked());
>+
>+	sbinfo = au_sbi(sb);
>+	if (unlikely(!sbinfo))
>+		return;
>+
>+	au_fsync_br(sb);
>+
>+	si_write_lock(sb);
>+	if (au_opt_test(au_mntflags(sb), PLINK))
>+		au_plink_put(sb);
>+	spin_lock(&sbinfo->si_mntcache_lock);
>+	sbinfo->si_mntcache = NULL;
>+	spin_unlock(&sbinfo->si_mntcache_lock);
>+	si_write_unlock(sb);
>+}
>+
>+/* final actions when unmounting a file system */
>+static void aufs_put_super(struct super_block *sb)
>+{
>+	struct au_sbinfo *sbinfo;
>+
>+	AuTraceEnter();
>+
>+	sbinfo = au_sbi(sb);
>+	if (unlikely(!sbinfo))
>+		return;
>+	kobject_put(&sbinfo->si_kobj);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * refresh dentry and inode at remount time.
>+ */
>+static int do_refresh(struct dentry *dentry, mode_t type,
>+		      unsigned int dir_flags)
>+{
>+	int err;
>+	struct dentry *parent;
>+	struct inode *inode;
>+
>+	LKTRTrace("%.*s, 0%o\n", AuDLNPair(dentry), type);
>+	inode = dentry->d_inode;
>+	AuDebugOn(!inode);
>+
>+	di_write_lock_child(dentry);
>+	parent = dget_parent(dentry);
>+	di_read_lock_parent(parent, AuLock_IR);
>+	/* returns a number of positive dentries */
>+	err = au_refresh_hdentry(dentry, type);
>+	//err = -1;
>+	if (err >= 0) {
>+		err = au_refresh_hinode(inode, dentry);
>+		//err = -1;
>+		if (!err && type == S_IFDIR)
>+			au_reset_hinotify(inode, dir_flags);
>+	}
>+	if (unlikely(err))
>+		AuErr("unrecoverable error %d, %.*s\n", err, AuDLNPair(dentry));
>+	di_read_unlock(parent, AuLock_IR);
>+	dput(parent);
>+	di_write_unlock(dentry);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int test_dir(struct dentry *dentry, void *arg)
>+{
>+	return S_ISDIR(dentry->d_inode->i_mode);
>+}
>+
>+//todo: merge with refresh_nondir()
>+static int refresh_dir(struct dentry *root, au_gen_t sgen)
>+{
>+	int err, i, j, ndentry, e;
>+	const unsigned int flags = au_hi_flags(root->d_inode, /*isdir*/1);
>+	struct au_dcsub_pages dpages;
>+	struct au_dpage *dpage;
>+	struct dentry **dentries;
>+	struct inode *inode;
>+
>+	LKTRTrace("sgen %d\n", sgen);
>+	SiMustWriteLock(root->d_sb);
>+	//todo: dont trust BKL.
>+	AuDebugOn(au_digen(root) != sgen || !kernel_locked());
>+
>+	err = 0;
>+	list_for_each_entry(inode, &root->d_sb->s_inodes, i_sb_list)
>+		if (S_ISDIR(inode->i_mode) && au_iigen(inode) != sgen) {
>+			ii_write_lock_child(inode);
>+			e = au_refresh_hinode_self(inode);
>+			//e = -1;
>+			ii_write_unlock(inode);
>+			if (unlikely(e)) {
>+				LKTRTrace("e %d, i%lu\n", e, inode->i_ino);
>+				if (!err)
>+					err = e;
>+				/* go on even if err */
>+			}
>+		}
>+
>+	e = au_dpages_init(&dpages, GFP_TEMPORARY);
>+	if (unlikely(e)) {
>+		if (!err)
>+			err = e;
>+		goto out;
>+	}
>+	e = au_dcsub_pages(&dpages, root, test_dir, NULL);
>+	if (unlikely(e)) {
>+		if (!err)
>+			err = e;
>+		goto out_dpages;
>+	}
>+
>+	for (i = 0; !e && i < dpages.ndpage; i++) {
>+		dpage = dpages.dpages + i;
>+		dentries = dpage->dentries;
>+		ndentry = dpage->ndentry;
>+		for (j = 0; !e && j < ndentry; j++) {
>+			struct dentry *d;
>+			d = dentries[j];
>+#ifdef CONFIG_AUFS_DEBUG
>+			{
>+				struct dentry *parent;
>+				parent = dget_parent(d);
>+				AuDebugOn(!S_ISDIR(d->d_inode->i_mode)
>+					  || IS_ROOT(d)
>+					  || au_digen(parent) != sgen);
>+				dput(parent);
>+			}
>+#endif
>+			if (au_digen(d) != sgen) {
>+				e = do_refresh(d, S_IFDIR, flags);
>+				//e = -1;
>+				if (unlikely(e && !err))
>+					err = e;
>+				/* break on err */
>+			}
>+		}
>+	}
>+
>+ out_dpages:
>+	au_dpages_free(&dpages);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int test_nondir(struct dentry *dentry, void *arg)
>+{
>+	return !S_ISDIR(dentry->d_inode->i_mode);
>+}
>+
>+static int refresh_nondir(struct dentry *root, au_gen_t sgen, int do_dentry)
>+{
>+	int err, i, j, ndentry, e;
>+	struct au_dcsub_pages dpages;
>+	struct au_dpage *dpage;
>+	struct dentry **dentries;
>+	struct inode *inode;
>+
>+	LKTRTrace("sgen %d\n", sgen);
>+	SiMustWriteLock(root->d_sb);
>+	//todo: dont trust BKL.
>+	AuDebugOn(au_digen(root) != sgen || !kernel_locked());
>+
>+	err = 0;
>+	list_for_each_entry(inode, &root->d_sb->s_inodes, i_sb_list)
>+		if (!S_ISDIR(inode->i_mode) && au_iigen(inode) != sgen) {
>+			ii_write_lock_child(inode);
>+			e = au_refresh_hinode_self(inode);
>+			//e = -1;
>+			ii_write_unlock(inode);
>+			if (unlikely(e)) {
>+				LKTRTrace("e %d, i%lu\n", e, inode->i_ino);
>+				if (!err)
>+					err = e;
>+				/* go on even if err */
>+			}
>+		}
>+
>+	if (!do_dentry)
>+		goto out;
>+
>+	e = au_dpages_init(&dpages, GFP_TEMPORARY);
>+	if (unlikely(e)) {
>+		if (!err)
>+			err = e;
>+		goto out;
>+	}
>+	e = au_dcsub_pages(&dpages, root, test_nondir, NULL);
>+	if (unlikely(e)) {
>+		if (!err)
>+			err = e;
>+		goto out_dpages;
>+	}
>+
>+	for (i = 0; i < dpages.ndpage; i++) {
>+		dpage = dpages.dpages + i;
>+		dentries = dpage->dentries;
>+		ndentry = dpage->ndentry;
>+		for (j = 0; j < ndentry; j++) {
>+			struct dentry *d;
>+			d = dentries[j];
>+#ifdef CONFIG_AUFS_DEBUG
>+			{
>+				struct dentry *parent;
>+				parent = dget_parent(d);
>+				AuDebugOn(S_ISDIR(d->d_inode->i_mode)
>+					  || au_digen(parent) != sgen);
>+				dput(parent);
>+			}
>+#endif
>+			inode = d->d_inode;
>+			if (inode && au_digen(d) != sgen) {
>+				e = do_refresh(d, inode->i_mode & S_IFMT, 0);
>+				//e = -1;
>+				if (unlikely(e && !err))
>+					err = e;
>+				/* go on even err */
>+			}
>+		}
>+	}
>+
>+ out_dpages:
>+	au_dpages_free(&dpages);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* stop extra interpretation of errno in mount(8), and strange error messages */
>+static int cvt_err(int err)
>+{
>+	AuTraceErr(err);
>+
>+	switch (err) {
>+	case -ENOENT:
>+	case -ENOTDIR:
>+	case -EEXIST:
>+	case -EIO:
>+		err = -EINVAL;
>+	}
>+	return err;
>+}
>+
>+/* protected by s_umount */
>+static int aufs_remount_fs(struct super_block *sb, int *flags, char *data)
>+{
>+	int err;
>+	struct dentry *root;
>+	struct inode *inode;
>+	struct au_opts opts;
>+	unsigned int dlgt;
>+	struct au_sbinfo *sbinfo;
>+
>+	//au_debug_on();
>+	LKTRTrace("flags 0x%x, data %s, len %lu\n",
>+		  *flags, data ? data : "NULL",
>+		  (unsigned long)(data ? strlen(data) : 0));
>+
>+	au_fsync_br(sb);
>+	err = 0;
>+	if (!data || !*data)
>+		goto out; /* success */
>+
>+	err = -ENOMEM;
>+	memset(&opts, 0, sizeof(opts));
>+	opts.opt = (void *)__get_free_page(GFP_TEMPORARY);
>+	//if (LktrCond) {free_page((unsigned long)opts.opt); opts.opt = NULL;}
>+	if (unlikely(!opts.opt))
>+		goto out;
>+	opts.max_opt = PAGE_SIZE / sizeof(*opts.opt);
>+	opts.flags = AuOpts_REMOUNT;
>+
>+	/* parse it before aufs lock */
>+	err = au_opts_parse(sb, *flags, data, &opts);
>+	//if (LktrCond) {au_free_opts(&opts); err = -1;}
>+	if (unlikely(err))
>+		goto out_opts;
>+
>+	sbinfo = au_sbi(sb);
>+	root = sb->s_root;
>+	inode = root->d_inode;
>+	mutex_lock(&inode->i_mutex);
>+	aufs_write_lock(root);
>+
>+	//DbgSleep(3);
>+
>+	/* au_do_opts() may return an error */
>+	err = au_opts_remount(sb, &opts);
>+	//if (LktrCond) err = -1;
>+	au_opts_free(&opts);
>+
>+	if (au_ftest_opts(opts.flags, REFRESH_DIR)
>+	    || au_ftest_opts(opts.flags, REFRESH_NONDIR)) {
>+		int rerr;
>+		au_gen_t sigen;
>+
>+		dlgt = !!au_opt_test_dlgt(sbinfo->si_mntflags);
>+		au_opt_clr(sbinfo->si_mntflags, DLGT);
>+		au_sigen_inc(sb);
>+		au_reset_hinotify(inode, au_hi_flags(inode, /*isdir*/1));
>+		sigen = au_sigen(sb);
>+		au_fclr_si(sbinfo, FAILED_REFRESH_DIRS);
>+
>+		DiMustNoWaiters(root);
>+		IiMustNoWaiters(root->d_inode);
>+		di_write_unlock(root);
>+
>+		rerr = refresh_dir(root, sigen);
>+		if (unlikely(rerr)) {
>+			au_fset_si(sbinfo, FAILED_REFRESH_DIRS);
>+			AuWarn("Refreshing directories failed, ignores (%d)\n",
>+			       rerr);
>+		}
>+
>+		if (unlikely(au_ftest_opts(opts.flags, REFRESH_NONDIR))) {
>+			//au_debug_on();
>+			rerr = refresh_nondir(root, sigen, !rerr);
>+			if (unlikely(rerr))
>+				AuWarn("Refreshing non-directories failed,"
>+				       " ignores (%d)\n", rerr);
>+			//au_debug_off();
>+		}
>+
>+		/* aufs_write_lock() calls ..._child() */
>+		di_write_lock_child(root);
>+
>+		au_cpup_attr_all(inode);
>+		if (unlikely(dlgt))
>+			au_opt_set(sbinfo->si_mntflags, DLGT);
>+	}
>+
>+	aufs_write_unlock(root);
>+	mutex_unlock(&inode->i_mutex);
>+
>+ out_opts:
>+	free_page((unsigned long)opts.opt);
>+ out:
>+	err = cvt_err(err);
>+	AuTraceErr(err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+static struct super_operations aufs_sop = {
>+	.alloc_inode	= aufs_alloc_inode,
>+	.destroy_inode	= aufs_destroy_inode,
>+	//.dirty_inode	= aufs_dirty_inode,
>+	//.write_inode	= aufs_write_inode,
>+	//void (*put_inode) (struct inode *);
>+	.drop_inode	= generic_delete_inode,
>+	//.delete_inode	= aufs_delete_inode,
>+	//.clear_inode	= aufs_clear_inode,
>+
>+	.show_options	= aufs_show_options,
>+	.statfs		= aufs_statfs,
>+
>+	.put_super	= aufs_put_super,
>+	//void (*write_super) (struct super_block *);
>+	//int (*sync_fs)(struct super_block *sb, int wait);
>+	//void (*write_super_lockfs) (struct super_block *);
>+	//void (*unlockfs) (struct super_block *);
>+	.remount_fs	= aufs_remount_fs,
>+	/* depends upon umount flags. also use put_super() (< 2.6.18) */
>+	.umount_begin	= aufs_umount_begin
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int alloc_root(struct super_block *sb)
>+{
>+	int err;
>+	struct inode *inode;
>+	struct dentry *root;
>+
>+	AuTraceEnter();
>+
>+	err = -ENOMEM;
>+	inode = au_iget_locked(sb, AUFS_ROOT_INO);
>+	//if (LktrCond) {iput(inode); inode = NULL;}
>+	err = PTR_ERR(inode);
>+	if (IS_ERR(inode))
>+		goto out;
>+	unlock_new_inode(inode);
>+	inode->i_mode = S_IFDIR;
>+	root = d_alloc_root(inode);
>+	//if (LktrCond) {igrab(inode); dput(root); root = NULL;}
>+	if (unlikely(!root))
>+		goto out_iput;
>+	err = PTR_ERR(root);
>+	if (IS_ERR(root))
>+		goto out_iput;
>+
>+	err = au_alloc_dinfo(root);
>+	//if (LktrCond){au_rw_write_unlock(&au_di(root)->di_rwsem);err=-1;}
>+	if (!err) {
>+		sb->s_root = root;
>+		return 0; /* success */
>+	}
>+	dput(root);
>+	goto out; /* do not iput */
>+
>+ out_iput:
>+	iget_failed(inode);
>+	iput(inode);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+
>+}
>+
>+static int aufs_fill_super(struct super_block *sb, void *raw_data, int silent)
>+{
>+	int err;
>+	struct dentry *root;
>+	struct inode *inode;
>+	struct au_opts opts;
>+	char *arg = raw_data;
>+
>+	//au_debug_on();
>+	if (unlikely(!arg || !*arg)) {
>+		err = -EINVAL;
>+		AuErr("no arg\n");
>+		goto out;
>+	}
>+	LKTRTrace("%s, silent %d\n", arg, silent);
>+
>+	err = -ENOMEM;
>+	memset(&opts, 0, sizeof(opts));
>+	opts.opt = (void *)__get_free_page(GFP_TEMPORARY);
>+	//if (LktrCond) {free_page((unsigned long)opts.opt); opts.opt = NULL;}
>+	if (unlikely(!opts.opt))
>+		goto out;
>+	opts.max_opt = PAGE_SIZE / sizeof(*opts.opt);
>+
>+	err = au_si_alloc(sb);
>+	//if (LktrCond) {si_write_unlock(sb);free_sbinfo(sb);err=-1;}
>+	if (unlikely(err))
>+		goto out_opts;
>+	SiMustWriteLock(sb);
>+	/* all timestamps always follow the ones on the branch */
>+	sb->s_flags |= MS_NOATIME | MS_NODIRATIME;
>+	sb->s_op = &aufs_sop;
>+	sb->s_magic = AUFS_SUPER_MAGIC;
>+	au_init_export_op(sb);
>+
>+	err = alloc_root(sb);
>+	//if (LktrCond) {au_rw_write_unlock(&au_di(sb->s_root)->di_rwsem);
>+	//dput(sb->s_root);sb->s_root=NULL;err=-1;}
>+	if (unlikely(err)) {
>+		AuDebugOn(sb->s_root);
>+		si_write_unlock(sb);
>+		goto out_info;
>+	}
>+	root = sb->s_root;
>+	DiMustWriteLock(root);
>+	inode = root->d_inode;
>+	inode->i_nlink = 2;
>+
>+	/*
>+	 * actually we can parse options regardless aufs lock here.
>+	 * but at remount time, parsing must be done before aufs lock.
>+	 * so we follow the same rule.
>+	 */
>+	ii_write_lock_parent(inode);
>+	aufs_write_unlock(root);
>+	err = au_opts_parse(sb, sb->s_flags, arg, &opts);
>+	//if (LktrCond) {au_opts_free(&opts); err = -1;}
>+	if (unlikely(err))
>+		goto out_root;
>+
>+	/* lock vfs_inode first, then aufs. */
>+	mutex_lock(&inode->i_mutex);
>+	inode->i_op = &aufs_dir_iop;
>+	inode->i_fop = &aufs_dir_fop;
>+	aufs_write_lock(root);
>+
>+	sb->s_maxbytes = 0;
>+	err = au_opts_mount(sb, &opts);
>+	//if (LktrCond) err = -1;
>+	au_opts_free(&opts);
>+	if (unlikely(err))
>+		goto out_unlock;
>+	AuDebugOn(!sb->s_maxbytes);
>+
>+	//AuDbgDentry(root);
>+	aufs_write_unlock(root);
>+	mutex_unlock(&inode->i_mutex);
>+	//AuDbgSb(sb);
>+	goto out_opts; /* success */
>+
>+ out_unlock:
>+	aufs_write_unlock(root);
>+	mutex_unlock(&inode->i_mutex);
>+ out_root:
>+	dput(root);
>+	sb->s_root = NULL;
>+ out_info:
>+	au_fset_si(au_sbi(sb), FAILED_INIT);
>+	kobject_put(&au_sbi(sb)->si_kobj);
>+	sb->s_fs_info = NULL;
>+ out_opts:
>+	free_page((unsigned long)opts.opt);
>+ out:
>+	AuTraceErr(err);
>+	err = cvt_err(err);
>+	AuTraceErr(err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int aufs_get_sb(struct file_system_type *fs_type, int flags,
>+		       const char *dev_name, void *raw_data,
>+		       struct vfsmount *mnt)
>+{
>+	int err;
>+
>+	/* all timestamps always follow the ones on the branch */
>+	/* mnt->mnt_flags |= MNT_NOATIME | MNT_NODIRATIME; */
>+	err = get_sb_nodev(fs_type, flags, raw_data, aufs_fill_super, mnt);
>+	if (!err) {
>+		struct super_block *sb = mnt->mnt_sb;
>+		struct au_sbinfo *sbinfo = au_sbi(sb);
>+
>+		/* no get/put */
>+		spin_lock_init(&sbinfo->si_mntcache_lock);
>+		sbinfo->si_mntcache = mnt;
>+
>+		au_sbilist_lock();
>+		au_sbilist_add(sbinfo);
>+		si_write_lock(sb);
>+		sysaufs_brs_add(sb, 0);
>+		si_write_unlock(sb);
>+		au_sbilist_unlock();
>+	}
>+	return err;
>+}
>+
>+struct file_system_type aufs_fs_type = {
>+	.name		= AUFS_FSTYPE,
>+	.fs_flags	= FS_REVAL_DOT, /* for UDBA and NFS branch */
>+	.get_sb		= aufs_get_sb,
>+	.kill_sb	= generic_shutdown_super,
>+	//.kill_sb	= kill_anon_super,
>+	/* no need to __module_get() and module_put(). */
>+	.owner		= THIS_MODULE,
>+};
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/super.h linux-2.6.25.4-unionfs/fs/aufs/super.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/super.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/super.h	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,410 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * super_block operations
>+ *
>+ * $Id: super.h,v 1.5 2008/05/19 01:50:18 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_SUPER_H__
>+#define __AUFS_SUPER_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/cramfs_fs.h>
>+#include <linux/kobject.h>
>+#include <linux/magic.h>
>+#include <linux/aufs_type.h>
>+//#include "hinode.h"
>+#include "misc.h"
>+//#include "opts.h"
>+#include "wkq.h"
>+
>+typedef ssize_t (*au_readf_t)(struct file *, char __user *, size_t, loff_t *);
>+typedef ssize_t (*au_writef_t)(struct file *, const char __user *, size_t,
>+			       loff_t *);
>+
>+struct au_wbr_copyup_operations {
>+	int (*copyup)(struct dentry *dentry);
>+};
>+
>+struct au_wbr_create_operations {
>+	int (*create)(struct dentry *dentry, int isdir);
>+	int (*init)(struct super_block *sb);
>+	int (*fin)(struct super_block *sb);
>+};
>+
>+struct au_wbr_mfs {
>+	struct mutex	mfs_lock; /* protect this structure */
>+	unsigned long	mfs_jiffy;
>+	unsigned long	mfs_expire;
>+	aufs_bindex_t	mfs_bindex;
>+
>+	u64		mfsrr_bytes;
>+	u64		mfsrr_watermark;
>+};
>+
>+/* sbinfo status flags */
>+/*
>+ * set true when refresh_dirs() failed at remount time.
>+ * then try refreshing dirs at access time again.
>+ * if it is false, refreshing dirs at access time is unnecesary
>+ */
>+#define AuSi_FAILED_REFRESH_DIRS	1
>+#define AuSi_FAILED_INIT		(1 << 1)
>+#define au_ftest_si(sbinfo, name)	((sbinfo)->au_si_status & AuSi_##name)
>+#define au_fset_si(sbinfo, name) \
>+	{ (sbinfo)->au_si_status |= AuSi_##name; }
>+#define au_fclr_si(sbinfo, name) \
>+	{ (sbinfo)->au_si_status &= ~AuSi_##name; }
>+
>+struct au_branch;
>+struct au_sbinfo {
>+	/* nowait tasks in the system-wide workqueue */
>+	struct au_nowait_tasks	si_nowait;
>+
>+	struct au_rwsem		si_rwsem;
>+
>+	/* branch management */
>+	au_gen_t		si_generation;
>+
>+	/* see above flags */
>+	unsigned char		au_si_status;
>+
>+	aufs_bindex_t		si_bend;
>+	aufs_bindex_t		si_last_br_id;
>+	struct au_branch	**si_branch;
>+
>+	/* policy to select a writable branch */
>+	unsigned char		si_wbr_copyup;
>+	unsigned char		si_wbr_create;
>+	struct au_wbr_copyup_operations *si_wbr_copyup_ops;
>+	struct au_wbr_create_operations *si_wbr_create_ops;
>+
>+	/* round robin */
>+	atomic_t		si_wbr_rr_next;
>+
>+	/* most free space */
>+	struct au_wbr_mfs	si_wbr_mfs;
>+
>+	/* mount flags */
>+	/* include/asm-ia64/siginfo.h defines a macro named si_flags */
>+	unsigned int		si_mntflags;
>+
>+	/* external inode number (bitmap and translation table) */
>+	au_readf_t		si_xread;
>+	au_writef_t		si_xwrite;
>+	struct file		*si_xib;
>+	struct mutex		si_xib_mtx; /* protect xib members */
>+	unsigned long		*si_xib_buf;
>+	unsigned long		si_xib_last_pindex;
>+	int			si_xib_next_bit;
>+	//unsigned long long	si_xib_limit;	/* Max xib file size */
>+
>+	/* readdir cache time, max, in HZ */
>+	unsigned long		si_rdcache;
>+
>+	/*
>+	 * If the number of whiteouts are larger than si_dirwh, leave all of
>+	 * them after au_whtmp_ren to reduce the cost of rmdir(2).
>+	 * future fsck.aufs or kernel thread will remove them later.
>+	 * Otherwise, remove all whiteouts and the dir in rmdir(2).
>+	 */
>+	unsigned int		si_dirwh;
>+
>+	/*
>+	 * rename(2) a directory with all children.
>+	 */
>+	//int			si_rendir;
>+
>+	/* pseudo_link list */ // dirty
>+	spinlock_t		si_plink_lock;
>+	struct list_head	si_plink;
>+
>+	/* dirty, for export, async ops, and sysfs */
>+	spinlock_t		si_mntcache_lock;
>+	struct vfsmount		*si_mntcache;	/* no get/put */
>+
>+	/*
>+	 * sysfs and lifetime management.
>+	 * this is not a small structure and it may be a waste of memory in case
>+	 * of sysfs is disabled, particulary when many aufs-es are mounted.
>+	 */
>+	struct kobject		si_kobj;
>+
>+	//todo: remove this list.
>+	/* super_blocks list is not exported */
>+	struct list_head	si_list;
>+
>+#ifdef CONFIG_AUFS_ROBR
>+	/* locked vma list for mmap() */ // dirty
>+	spinlock_t		si_lvma_lock;
>+	struct list_head	si_lvma;
>+#endif
>+
>+	/* dirty, necessary for unmounting, sysfs and sysrq */
>+	struct super_block	*si_sb;
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* policy to select one among writable branches */
>+#define AuWbrCopyup(sbinfo, args... ) \
>+	(sbinfo)->si_wbr_copyup_ops->copyup(args)
>+#define AuWbrCreate(sbinfo, args... ) \
>+	(sbinfo)->si_wbr_create_ops->create(args)
>+
>+/* flags for si_read_lock()/aufs_read_lock()/di_read_lock() */
>+#define AuLock_DW		1		/* write-lock dentry */
>+#define AuLock_IR		(1 << 1)	/* read-lock inode */
>+#define AuLock_IW		(1 << 2)	/* write-lock inode */
>+#define AuLock_FLUSH		(1 << 3)	/* wait for 'nowait' tasks */
>+#define AuLock_DIR		(1 << 4)	/* target is a dir */
>+#define au_ftest_lock(flags, name)	((flags) & AuLock_##name)
>+#define au_fset_lock(flags, name)	{ (flags) |= AuLock_##name; }
>+#define au_fclr_lock(flags, name)	{ (flags) &= ~AuLock_##name; }
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* super.c */
>+extern struct file_system_type aufs_fs_type;
>+struct inode *au_iget_locked(struct super_block *sb, ino_t ino);
>+
>+/* sbinfo.c */
>+void au_si_free(struct kobject *kobj);
>+int au_si_alloc(struct super_block *sb);
>+struct au_branch *au_sbr(struct super_block *sb, aufs_bindex_t bindex);
>+au_gen_t au_sigen_inc(struct super_block *sb);
>+int au_find_bindex(struct super_block *sb, struct au_branch *br);
>+
>+void aufs_read_lock(struct dentry *dentry, int flags);
>+void aufs_read_unlock(struct dentry *dentry, int flags);
>+void aufs_write_lock(struct dentry *dentry);
>+void aufs_write_unlock(struct dentry *dentry);
>+void aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int isdir);
>+void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2);
>+
>+aufs_bindex_t au_new_br_id(struct super_block *sb);
>+struct vfsmount *au_mntcache_get(struct super_block *sb);
>+
>+/* wbr_policy.c */
>+extern struct au_wbr_copyup_operations au_wbr_copyup_ops[];
>+extern struct au_wbr_create_operations au_wbr_create_ops[];
>+int au_cpdown_dirs(struct dentry *dentry, aufs_bindex_t bdst,
>+		   struct dentry *locked);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline struct au_sbinfo *au_sbi(struct super_block *sb)
>+{
>+	return sb->s_fs_info;
>+}
>+
>+static inline const char *au_sbtype(struct super_block *sb)
>+{
>+	return sb->s_type->name;
>+}
>+
>+static inline int au_test_aufs(struct super_block *sb)
>+{
>+	return (sb->s_magic == AUFS_SUPER_MAGIC);
>+}
>+
>+static inline int au_test_nfs(struct super_block *sb)
>+{
>+#ifdef CONFIG_AUFS_BR_NFS
>+	return (sb->s_magic == NFS_SUPER_MAGIC);
>+#else
>+	return 0;
>+#endif
>+}
>+
>+static inline int au_test_fuse(struct super_block *sb)
>+{
>+#ifdef CONFIG_AUFS_WORKAROUND_FUSE
>+#ifdef FUSE_SUPER_MAGIC
>+	BUILD_BUG_ON(FUSE_SUPER_MAGIC != 0x65735546);
>+	return (sb->s_magic == FUSE_SUPER_MAGIC);
>+#else
>+	return !strcmp(au_sbtype(sb), "fuse");
>+#endif
>+#endif
>+	return 0;
>+}
>+
>+static inline int au_test_xfs(struct super_block *sb)
>+{
>+#ifdef CONFIG_AUFS_BR_XFS
>+#ifdef XFS_SB_MAGIC
>+	BUILD_BUG_ON(XFS_SB_MAGIC != 0x58465342);
>+	return (sb->s_magic == XFS_SB_MAGIC);
>+#else
>+	return !strcmp(au_sbtype(sb), "xfs");
>+#endif
>+#endif
>+	return 0;
>+}
>+
>+static inline int au_test_tmpfs(struct super_block *sb)
>+{
>+#ifdef CONFIG_TMPFS
>+#ifdef TMPFS_MAGIC
>+	BUILD_BUG_ON(TMPFS_MAGIC != 0x01021994);
>+	return (sb->s_magic == TMPFS_MAGIC);
>+#else
>+	return !strcmp(au_sbtype(sb), "tmpfs");
>+#endif
>+#endif
>+	return 0;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#ifdef CONFIG_AUFS_EXPORT
>+extern struct export_operations aufs_export_op;
>+static inline void au_init_export_op(struct super_block *sb)
>+{
>+	sb->s_export_op = &aufs_export_op;
>+}
>+
>+static inline int au_test_nfsd(struct task_struct *tsk)
>+{
>+	return (!tsk->mm && !strcmp(tsk->comm, "nfsd"));
>+}
>+
>+static inline void au_nfsd_lockdep_off(void)
>+{
>+	if (au_test_nfsd(current))
>+		lockdep_off();
>+}
>+
>+static inline void au_nfsd_lockdep_on(void)
>+{
>+	if (au_test_nfsd(current))
>+		lockdep_on();
>+}
>+#else
>+static inline int au_test_nfsd(struct task_struct *tsk)
>+{
>+	return 0;
>+}
>+
>+static inline void au_init_export_op(struct super_block *sb)
>+{
>+	/* nothing */
>+}
>+
>+#define au_nfsd_lockdep_off()	do {} while (0)
>+#define au_nfsd_lockdep_on()	do {} while (0)
>+#endif /* CONFIG_AUFS_EXPORT */
>+
>+#ifdef CONFIG_AUFS_ROBR
>+static inline int au_test_nested(struct super_block *h_sb)
>+{
>+	return 0;
>+}
>+
>+static inline void au_robr_lvma_init(struct au_sbinfo *sbinfo)
>+{
>+	spin_lock_init(&sbinfo->si_lvma_lock);
>+	INIT_LIST_HEAD(&sbinfo->si_lvma);
>+}
>+#else
>+static inline int au_test_nested(struct super_block *h_sb)
>+{
>+	int err = 0;
>+	if (unlikely(au_test_aufs(h_sb))) {
>+		err = -EINVAL;
>+		AuTraceErr(err);
>+	}
>+	return err;
>+}
>+
>+static inline void au_robr_lvma_init(struct au_sbinfo *sbinfo)
>+{
>+	/* empty */
>+}
>+#endif /* CONFIG_AUFS_ROBR */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* lock superblock. mainly for entry point functions */
>+/*
>+ * si_noflush_read_lock, si_noflush_write_lock,
>+ * si_read_unlock, si_write_unlock, si_downgrade_lock
>+ */
>+AuSimpleLockRwsemFuncs(si_noflush, struct super_block *sb,
>+		       au_sbi(sb)->si_rwsem);
>+AuSimpleUnlockRwsemFuncs(si, struct super_block *sb, au_sbi(sb)->si_rwsem);
>+
>+static inline void si_read_lock(struct super_block *sb, int flags)
>+{
>+	if (au_ftest_lock(flags, FLUSH))
>+		au_nwt_flush(&au_sbi(sb)->si_nowait);
>+	si_noflush_read_lock(sb);
>+}
>+
>+static inline void si_write_lock(struct super_block *sb)
>+{
>+	au_nwt_flush(&au_sbi(sb)->si_nowait);
>+	si_noflush_write_lock(sb);
>+}
>+
>+static inline int si_read_trylock(struct super_block *sb, int flags)
>+{
>+	if (au_ftest_lock(flags, FLUSH))
>+		au_nwt_flush(&au_sbi(sb)->si_nowait);
>+	return si_noflush_read_trylock(sb);
>+}
>+
>+static inline int si_write_trylock(struct super_block *sb, int flags)
>+{
>+	if (au_ftest_lock(flags, FLUSH))
>+		au_nwt_flush(&au_sbi(sb)->si_nowait);
>+	return si_noflush_write_trylock(sb);
>+}
>+
>+/* to debug easier, do not make them inlined functions */
>+#define SiMustReadLock(sb)	AuRwMustReadLock(&au_sbi(sb)->si_rwsem)
>+#define SiMustWriteLock(sb)	AuRwMustWriteLock(&au_sbi(sb)->si_rwsem)
>+#define SiMustAnyLock(sb)	AuRwMustAnyLock(&au_sbi(sb)->si_rwsem)
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline aufs_bindex_t au_sbend(struct super_block *sb)
>+{
>+	SiMustAnyLock(sb);
>+	return au_sbi(sb)->si_bend;
>+}
>+
>+static inline unsigned int au_mntflags(struct super_block *sb)
>+{
>+	SiMustAnyLock(sb);
>+	return au_sbi(sb)->si_mntflags;
>+}
>+
>+static inline au_gen_t au_sigen(struct super_block *sb)
>+{
>+	SiMustAnyLock(sb);
>+	return au_sbi(sb)->si_generation;
>+}
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_SUPER_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/sysaufs.c linux-2.6.25.4-unionfs/fs/aufs/sysaufs.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/sysaufs.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/sysaufs.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,104 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * sysfs interface and lifetime management
>+ * they are necessary regardless sysfs is disabled.
>+ *
>+ * $Id: sysaufs.c,v 1.5 2008/05/19 01:50:47 sfjro Exp $
>+ */
>+
>+#include <linux/fs.h>
>+#include <linux/module.h>
>+#include <linux/sysfs.h>
>+#include "aufs.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* super_blocks list is not exported */
>+DEFINE_MUTEX(au_sbilist_mtx);
>+LIST_HEAD(au_sbilist);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static struct kset au_kset;
>+
>+#define AuSbiAttr(_name) { \
>+	.attr   = { .name = __stringify(_name), .mode = 0444 },	\
>+	.show   = sysaufs_sbi_##_name,				\
>+}
>+
>+static struct au_sbi_attr au_sbi_attr_xino = AuSbiAttr(xino);
>+struct attribute *au_sbi_attrs[] = {
>+	&au_sbi_attr_xino.attr,
>+	NULL,
>+};
>+
>+static struct sysfs_ops au_sbi_ops = {
>+	.show   = sysaufs_sbi_show
>+};
>+
>+static struct kobj_type au_sbi_ktype = {
>+	.release	= au_si_free,
>+	.sysfs_ops	= &au_sbi_ops,
>+	.default_attrs	= au_sbi_attrs,
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int sysaufs_si_init(struct au_sbinfo *sbinfo)
>+{
>+	int err;
>+
>+	sbinfo->si_kobj.kset = &au_kset;
>+	err = kobject_init_and_add(&sbinfo->si_kobj, &au_sbi_ktype,
>+				   NULL/*&au_kset.kobj*/,
>+				   SysaufsSb_PREFIX "%p", sbinfo);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void sysaufs_fin(void)
>+{
>+	AuDebugOn(!list_empty(&au_sbilist));
>+	sysfs_remove_group(&au_kset.kobj, au_attr_group);
>+	kset_unregister(&au_kset);
>+}
>+
>+int __init sysaufs_init(void)
>+{
>+	int err;
>+
>+	sysaufs_brs_init();
>+	au_kset.kobj.parent = fs_kobj;
>+	kobject_set_name(&au_kset.kobj, AUFS_NAME);
>+	au_kset.kobj.ktype = au_ktype;
>+	err = kset_register(&au_kset);
>+	if (unlikely(err))
>+		goto out;
>+	err = sysfs_create_group(&au_kset.kobj, au_attr_group);
>+	if (unlikely(err))
>+		kset_unregister(&au_kset);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/sysaufs.h linux-2.6.25.4-unionfs/fs/aufs/sysaufs.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/sysaufs.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/sysaufs.h	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,146 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * sysfs interface and lifetime management
>+ *
>+ * $Id: sysaufs.h,v 1.6 2008/05/19 01:50:47 sfjro Exp $
>+ */
>+
>+#ifndef __SYSAUFS_H__
>+#define __SYSAUFS_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/sysfs.h>
>+#include "module.h"
>+#include "super.h"
>+
>+/* entries under sysfs per super block */
>+enum {
>+	SysaufsSb_XINO,
>+	SysaufsSb_MNTPNT1,
>+	SysaufsSb_Last
>+};
>+
>+#define SysaufsSb_PREFIX	"si_"	/* followed by %p */
>+
>+struct au_sbi_attr {
>+	struct attribute attr;
>+	int (*show)(struct seq_file *seq, struct super_block *sb);
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* sysaufs.c */
>+extern struct mutex au_sbilist_mtx;
>+extern struct list_head au_sbilist;
>+extern struct attribute *au_sbi_attrs[];
>+int sysaufs_si_init(struct au_sbinfo *sbinfo);
>+int __init sysaufs_init(void);
>+void sysaufs_fin(void);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline void au_sbilist_lock(void)
>+{
>+	mutex_lock(&au_sbilist_mtx);
>+}
>+
>+static inline void au_sbilist_unlock(void)
>+{
>+	mutex_unlock(&au_sbilist_mtx);
>+}
>+
>+static inline void au_sbilist_del(struct au_sbinfo *sbinfo)
>+{
>+	list_del(&sbinfo->si_list);
>+}
>+
>+static inline void au_sbilist_add(struct au_sbinfo *sbinfo)
>+{
>+	/* the order in this list is important */
>+	list_add_tail(&sbinfo->si_list, &au_sbilist);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_branch;
>+#ifdef CONFIG_SYSFS
>+/* sysfs.c */
>+extern struct attribute_group *au_attr_group;
>+extern struct kobj_type *au_ktype;
>+
>+int sysaufs_sbi_xino(struct seq_file *seq, struct super_block *sb);
>+int sysaufs_sbi_mntpnt1(struct seq_file *seq, struct super_block *sb);
>+ssize_t sysaufs_sbi_show(struct kobject *kobj, struct attribute *attr,
>+			 char *buf);
>+
>+void sysaufs_br_init(struct au_branch *br);
>+void sysaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex);
>+void sysaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex);
>+
>+#define sysaufs_brs_init()	do {} while (0)
>+
>+#else
>+#define au_attr_group	NULL
>+#define au_ktype	NULL
>+
>+static inline
>+int sysaufs_sbi_xino(struct seq_file *seq, struct super_block *sb)
>+{
>+	return 0;
>+}
>+
>+static inline
>+int sysaufs_sbi_mntpnt1(struct seq_file *seq, struct super_block *sb)
>+{
>+	return 0;
>+}
>+
>+static inline
>+ssize_t sysaufs_sbi_show(struct kobject *kobj, struct attribute *attr,
>+			 char *buf)
>+{
>+	return 0;
>+}
>+
>+static inline void sysaufs_br_init(struct au_branch *br)
>+{
>+	/* empty */
>+}
>+
>+static inline void sysaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	/* nothing */
>+}
>+
>+static inline void sysaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	/* nothing */
>+}
>+
>+static inline void sysaufs_brs_init(void)
>+{
>+	sysaufs_brs = 0;
>+}
>+#endif /* CONFIG_SYSFS */
>+
>+#endif /* __KERNEL__ */
>+#endif /* __SYSAUFS_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/sysfs.c linux-2.6.25.4-unionfs/fs/aufs/sysfs.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/sysfs.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/sysfs.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,456 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * sysfs interface
>+ *
>+ * $Id: sysfs.c,v 1.4 2008/05/19 01:51:16 sfjro Exp $
>+ */
>+
>+#include <linux/fs.h>
>+#include <linux/module.h>
>+#include <linux/seq_file.h>
>+#include <linux/sysfs.h>
>+#include "aufs.h"
>+
>+
>+#ifdef CONFIG_AUFS_LOCAL
>+static ssize_t config_show(struct kobject *kobj, struct kobj_attribute *attr,
>+			   char *buf)
>+{
>+#define conf_bool(name)	"CONFIG_AUFS_" #name "=y\n"
>+	static const char opt[] =
>+#ifdef CONFIG_AUFS
>+		"CONFIG_AUFS=y\n"
>+#else
>+		"CONFIG_AUFS=m\n"
>+#endif
>+#ifdef CONFIG_AUFS_BRANCH_MAX_127
>+		conf_bool(BRANCH_MAX_127)
>+#elif defined(CONFIG_AUFS_BRANCH_MAX_511)
>+		conf_bool(BRANCH_MAX_511)
>+#elif defined(CONFIG_AUFS_BRANCH_MAX_1023)
>+		conf_bool(BRANCH_MAX_1023)
>+#elif defined(CONFIG_AUFS_BRANCH_MAX_32767)
>+		conf_bool(BRANCH_MAX_32767)
>+#endif
>+#ifdef CONFIG_AUFS_HINOTIFY
>+		conf_bool(HINOTIFY)
>+#endif
>+#ifdef CONFIG_AUFS_EXPORT
>+		conf_bool(EXPORT)
>+#endif
>+#ifdef CONFIG_AUFS_ROBR
>+		conf_bool(ROBR)
>+#endif
>+#ifdef CONFIG_AUFS_SHWH
>+		conf_bool(SHWH)
>+#endif
>+#ifdef CONFIG_AUFS_DLGT
>+		conf_bool(DLGT)
>+#endif
>+#ifdef CONFIG_AUFS_RR_SQUASHFS
>+		conf_bool(RR_SQUASHFS)
>+#endif
>+#ifdef CONFIG_AUFS_SEC_PERM_PATCH
>+		conf_bool(SEC_PERM_PATCH)
>+#endif
>+#ifdef CONFIG_AUFS_SPLICE_PATCH
>+		conf_bool(SPLICE_PATCH)
>+#endif
>+#ifdef CONFIG_AUFS_PUT_FILP_PATCH
>+		conf_bool(PUT_FILP_PATCH)
>+#endif
>+#ifdef CONFIG_AUFS_LHASH_PATCH
>+		conf_bool(LHASH_PATCH)
>+#endif
>+#ifdef CONFIG_AUFS_FSYNC_SUPER_PATCH
>+		conf_bool(FSYNC_SUPER_PATCH)
>+#endif
>+#ifdef CONFIG_AUFS_DENY_WRITE_ACCESS_PATCH
>+		conf_bool(DENY_WRITE_ACCESS_PATCH)
>+#endif
>+#ifdef CONFIG_AUFS_KSIZE_PATCH
>+		conf_bool(KSIZE_PATCH)
>+#endif
>+#ifdef CONFIG_AUFS_WORKAROUND_FUSE
>+		conf_bool(WORKAROUND_FUSE)
>+#endif
>+#ifdef CONFIG_AUFS_STAT
>+		conf_bool(STAT)
>+#endif
>+#ifdef CONFIG_AUFS_DEBUG
>+		conf_bool(DEBUG)
>+#endif
>+#ifdef CONFIG_AUFS_COMPAT
>+		conf_bool(COMPAT)
>+#endif
>+
>+/* automatic configurations */
>+#ifdef CONFIG_AUFS_BR_NFS
>+		conf_bool(BR_NFS)
>+#endif
>+#ifdef CONFIG_AUFS_MAGIC_SYSRQ
>+		conf_bool(MAGIC_SYSRQ)
>+#endif
>+		;
>+#undef conf_bool
>+
>+	char *p = buf;
>+	const char *end = buf + PAGE_SIZE;
>+
>+	p += snprintf(p, end - p, "%s", opt);
>+#ifdef DbgUdbaRace
>+	if (p < end)
>+		p += snprintf(p, end - p, "DbgUdbaRace=%d\n", DbgUdbaRace);
>+#endif
>+	if (p < end)
>+		return p - buf;
>+	else
>+		return -EFBIG;
>+}
>+
>+static struct kobj_attribute au_config_attr = __ATTR_RO(config);
>+#endif
>+
>+#ifdef CONFIG_AUFS_STAT
>+static ssize_t stat_show(struct kobject *kobj, struct kobj_attribute *attr,
>+			 char *buf)
>+{
>+	char *p = buf;
>+	const char *end = buf + PAGE_SIZE;
>+	int i;
>+
>+	p += snprintf(p, end - p, "wkq max_busy:");
>+	for (i = 0; p < end && i < aufs_nwkq; i++)
>+		p += snprintf(p, end - p, " %u", au_wkq[i].max_busy);
>+	if (p < end)
>+		p += snprintf(p, end - p, ", %u(generic)\n",
>+			      au_wkq[aufs_nwkq].max_busy);
>+
>+	if (p < end)
>+		return p - buf;
>+	else
>+		return -EFBIG;
>+}
>+
>+static struct kobj_attribute au_stat_attr = __ATTR_RO(stat);
>+#endif
>+
>+#ifdef CONFIG_AUFS_DEBUG
>+static ssize_t debug_show(struct kobject *kobj, struct kobj_attribute *attr,
>+			  char *buf)
>+{
>+	return sprintf(buf, "%d\n", au_debug_test());
>+}
>+
>+static ssize_t debug_store(struct kobject *kobj, struct kobj_attribute *attr,
>+			   const char *buf, size_t sz)
>+{
>+	LKTRTrace("%.*s\n", (unsigned int)sz, buf);
>+
>+	if (unlikely(!sz || (*buf != '0' && *buf != '1')))
>+		return -EOPNOTSUPP;
>+
>+	if (*buf == '0')
>+		au_debug_off();
>+	else if (*buf == '1')
>+		au_debug_on();
>+	return sz;
>+}
>+
>+static struct kobj_attribute au_debug_attr = __ATTR(debug, S_IRUGO | S_IWUSR,
>+						    debug_show, debug_store);
>+#endif
>+
>+static struct attribute *au_attr[] = {
>+#ifdef CONFIG_AUFS_LOCAL
>+	&au_config_attr.attr,
>+#endif
>+#ifdef CONFIG_AUFS_STAT
>+	&au_stat_attr.attr,
>+#endif
>+#ifdef CONFIG_AUFS_DEBUG
>+	&au_debug_attr.attr,
>+#endif
>+	NULL,	/* need to NULL terminate the list of attributes */
>+};
>+
>+static struct attribute_group au_attr_group_body = {
>+	.attrs = au_attr
>+};
>+
>+struct attribute_group *au_attr_group = &au_attr_group_body;
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * they are copied from linux/lib/kobject.c,
>+ * and will be exported in the future.
>+ */
>+static ssize_t au_attr_show(struct kobject *kobj, struct attribute *attr,
>+			    char *buf)
>+{
>+	struct kobj_attribute *kattr;
>+	ssize_t ret = -EIO;
>+
>+	kattr = container_of(attr, struct kobj_attribute, attr);
>+	if (kattr->show)
>+		ret = kattr->show(kobj, kattr, buf);
>+	return ret;
>+}
>+
>+#ifdef CONFIG_AUFS_DEBUG
>+static ssize_t au_attr_store(struct kobject *kobj, struct attribute *attr,
>+			     const char *buf, size_t count)
>+{
>+	struct kobj_attribute *kattr;
>+	ssize_t ret = -EIO;
>+
>+	kattr = container_of(attr, struct kobj_attribute, attr);
>+	if (kattr->store)
>+		ret = kattr->store(kobj, kattr, buf, count);
>+	return ret;
>+}
>+#endif
>+
>+static struct sysfs_ops sysaufs_ops = {
>+	.show   = au_attr_show,
>+#ifdef CONFIG_AUFS_DEBUG
>+	.store  = au_attr_store
>+#endif
>+};
>+
>+static struct kobj_type au_ktype_body = {
>+	.sysfs_ops = &sysaufs_ops
>+};
>+struct kobj_type *au_ktype = &au_ktype_body;
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int sysaufs_sbi_xino(struct seq_file *seq, struct super_block *sb)
>+{
>+	int err, dlgt;
>+	struct au_sbinfo *sbinfo;
>+	unsigned int mnt_flags;
>+	aufs_bindex_t bend, bindex;
>+	struct file *xf;
>+	struct kstat st;
>+
>+	AuTraceEnter();
>+
>+	sbinfo = au_sbi(sb);
>+	mnt_flags = au_mntflags(sb);
>+	if (unlikely(!au_opt_test(mnt_flags, XINO))) {
>+#ifdef CONFIG_AUFS_DEBUG
>+		AuDebugOn(sbinfo->si_xib);
>+		bend = au_sbend(sb);
>+		for (bindex = 0; bindex <= bend; bindex++)
>+			AuDebugOn(au_sbr(sb, bindex)->br_xino);
>+#endif
>+		err = 0;
>+		goto out; /* success */
>+	}
>+
>+	dlgt = !!au_opt_test_dlgt(mnt_flags);
>+	xf = sbinfo->si_xib;
>+	err = vfsub_getattr(xf->f_vfsmnt, xf->f_dentry, &st, dlgt);
>+	if (!err)
>+		seq_printf(seq, "%Lux%lu %Ld\n",
>+			   st.blocks, st.blksize, (long long)st.size);
>+	else
>+		seq_printf(seq, "err %d\n", err);
>+
>+	bend = au_sbend(sb);
>+	for (bindex = 0; !err && bindex <= bend; bindex++) {
>+		xf = au_sbr(sb, bindex)->br_xino;
>+		if (!xf)
>+			continue;
>+		seq_printf(seq, "%d: ", bindex);
>+		err = vfsub_getattr(xf->f_vfsmnt, xf->f_dentry, &st, dlgt);
>+		if (!err)
>+			seq_printf(seq, "%d, %Lux%lu %Ld\n",
>+				   file_count(xf), st.blocks, st.blksize,
>+				   (long long)st.size);
>+		else
>+			seq_printf(seq, "err %d\n", err);
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * the lifetime of branch is independent from the entry under sysfs.
>+ * sysfs handles the lifetime of the entry, and never call ->show() after it is
>+ * unlinked.
>+ */
>+#define SysaufsBr_PREFIX "br"
>+static int sysaufs_sbi_br(struct seq_file *seq, struct super_block *sb,
>+			  aufs_bindex_t bindex)
>+{
>+	int err;
>+	struct dentry *root;
>+	struct au_branch *br;
>+	struct path path;
>+
>+	LKTRTrace("b%d\n", bindex);
>+
>+	err = -ENOENT;
>+	if (unlikely(au_sbend(sb) < bindex))
>+		goto out;
>+
>+	err = 0;
>+	root = sb->s_root;
>+	di_read_lock_parent(root, !AuLock_IR);
>+	br = au_sbr(sb, bindex);
>+	path.mnt = br->br_mnt;
>+	path.dentry = au_h_dptr(root, bindex);
>+	seq_path(seq, &path, au_esc_chars);
>+	di_read_unlock(root, !AuLock_IR);
>+	seq_printf(seq, "=%s\n", au_optstr_br_perm(br->br_perm));
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static struct seq_file *au_seq(char *p, ssize_t len)
>+{
>+	struct seq_file *seq;
>+
>+	seq = kzalloc(sizeof(*seq), GFP_TEMPORARY);
>+	if (seq) {
>+		//mutex_init(&seq.lock);
>+		seq->buf = p;
>+		seq->count = 0;
>+		seq->size = len;
>+		return seq; /* success */
>+	}
>+
>+	seq = ERR_PTR(-ENOMEM);
>+	AuTraceErrPtr(seq);
>+	return seq;
>+}
>+
>+//todo: file size may exceed PAGE_SIZE
>+ssize_t sysaufs_sbi_show(struct kobject *kobj, struct attribute *attr,
>+			 char *buf)
>+{
>+	ssize_t err;
>+	struct au_sbinfo *sbinfo;
>+	struct super_block *sb;
>+	struct seq_file *seq;
>+	char *name;
>+	struct attribute **cattr;
>+
>+	LKTRTrace("%s/%s\n", kobject_name(kobj), attr->name);
>+
>+	sbinfo = container_of(kobj, struct au_sbinfo, si_kobj);
>+	sb = sbinfo->si_sb;
>+	si_noflush_read_lock(sb);
>+
>+	seq = au_seq(buf, PAGE_SIZE);
>+	err = PTR_ERR(seq);
>+	if (IS_ERR(seq))
>+		goto out;
>+
>+	name = (void *)attr->name;
>+	cattr = au_sbi_attrs;
>+	while (*cattr) {
>+		if (!strcmp(name, (*cattr)->name)) {
>+			err = container_of(*cattr, struct au_sbi_attr, attr)
>+				->show(seq, sb);
>+			goto out_seq;
>+		}
>+		cattr++;
>+	}
>+
>+	if (!strncmp(name, SysaufsBr_PREFIX, sizeof(SysaufsBr_PREFIX) - 1)) {
>+		name += sizeof(SysaufsBr_PREFIX) - 1;
>+		err = sysaufs_sbi_br(seq, sb, simple_strtol(name, NULL, 10));
>+		goto out_seq;
>+	}
>+	BUG();
>+
>+ out_seq:
>+	if (!err) {
>+		err = seq->count;
>+		/* sysfs limit */
>+		if (unlikely(err == PAGE_SIZE))
>+			err = -EFBIG;
>+	}
>+	kfree(seq);
>+ out:
>+	si_read_unlock(sb);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void sysaufs_br_init(struct au_branch *br)
>+{
>+	br->br_attr.name = br->br_name;
>+	br->br_attr.mode = S_IRUGO;
>+	br->br_attr.owner = THIS_MODULE;
>+}
>+
>+void sysaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	struct au_sbinfo *sbinfo;
>+	aufs_bindex_t bend;
>+
>+	LKTRTrace("b%d\n", bindex);
>+
>+	if (!sysaufs_brs)
>+		return;
>+
>+	sbinfo = au_sbi(sb);
>+	bend = au_sbend(sb);
>+	for (; bindex <= bend; bindex++)
>+		sysfs_remove_file(&sbinfo->si_kobj,
>+				  &au_sbr(sb, bindex)->br_attr);
>+}
>+
>+void sysaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	int err;
>+	struct kobject *kobj;
>+	aufs_bindex_t bend;
>+	struct au_branch *br;
>+
>+	LKTRTrace("b%d\n", bindex);
>+
>+	if (!sysaufs_brs)
>+		return;
>+
>+	kobj = &au_sbi(sb)->si_kobj;
>+	bend = au_sbend(sb);
>+	for (; bindex <= bend; bindex++) {
>+		br = au_sbr(sb, bindex);
>+		snprintf(br->br_name, sizeof(br->br_name),
>+			 SysaufsBr_PREFIX "%d", bindex);
>+		err = sysfs_create_file(kobj, &br->br_attr);
>+		if (unlikely(err))
>+			AuWarn("failed %s under sysfs(%d)\n", br->br_name, err);
>+	}
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/sysrq.c linux-2.6.25.4-unionfs/fs/aufs/sysrq.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/sysrq.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/sysrq.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,99 @@
>+/*
>+ * Copyright (C) 2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * magic sysrq hanlder
>+ *
>+ * $Id: sysrq.c,v 1.4 2008/05/04 23:53:27 sfjro Exp $
>+ */
>+
>+#include <linux/fs.h>
>+#include <linux/module.h>
>+#include <linux/moduleparam.h>
>+#include <linux/sysrq.h>
>+#include "aufs.h"
>+
>+static void sysrq_sb(struct super_block *sb)
>+{
>+	char *plevel;
>+	struct inode *i;
>+
>+	plevel = au_plevel;
>+	au_plevel = KERN_WARNING;
>+	au_debug_on();
>+
>+	pr_warning(AUFS_NAME ": superblock\n");
>+	au_dpri_sb(sb);
>+	pr_warning(AUFS_NAME ": root dentry\n");
>+	au_dpri_dentry(sb->s_root);
>+	pr_warning(AUFS_NAME ": isolated inode\n");
>+	list_for_each_entry(i, &sb->s_inodes, i_sb_list)
>+		if (list_empty(&i->i_dentry))
>+			au_dpri_inode(i);
>+
>+	au_plevel = plevel;
>+	au_debug_off();
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* module parameter */
>+static char *aufs_sysrq_key = "a";
>+module_param_named(sysrq, aufs_sysrq_key, charp, S_IRUGO);
>+MODULE_PARM_DESC(sysrq, "MagicSysRq key for " AUFS_NAME);
>+
>+static void au_sysrq(int key, struct tty_struct *tty)
>+{
>+	struct au_sbinfo *sbinfo;
>+
>+	//mutex_lock(&au_sbilist_mtx);
>+	list_for_each_entry(sbinfo, &au_sbilist, si_list)
>+		sysrq_sb(sbinfo->si_sb);
>+	//mutex_unlock(&au_sbilist_mtx);
>+}
>+
>+static struct sysrq_key_op au_sysrq_op = {
>+	.handler	= au_sysrq,
>+	.help_msg	= "Aufs",
>+	.action_msg	= "Aufs",
>+	.enable_mask	= SYSRQ_ENABLE_DUMP //??
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int __init au_sysrq_init(void)
>+{
>+	int err;
>+	char key;
>+
>+	err = -1;
>+	key = *aufs_sysrq_key;
>+	if ('a' <= key && key <= 'z')
>+		err = register_sysrq_key(key, &au_sysrq_op);
>+	if (unlikely(err))
>+		AuErr("err %d, sysrq=%c\n", err, key);
>+	return err;
>+}
>+
>+void au_sysrq_fin(void)
>+{
>+	int err;
>+	err = unregister_sysrq_key(*aufs_sysrq_key, &au_sysrq_op);
>+	if (unlikely(err))
>+		AuErr("err %d (ignored)\n", err);
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/vdir.c linux-2.6.25.4-unionfs/fs/aufs/vdir.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/vdir.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/vdir.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,934 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * virtual or vertical directory
>+ *
>+ * $Id: vdir.c,v 1.3 2008/04/28 03:05:48 sfjro Exp $
>+ */
>+
>+#include "aufs.h"
>+
>+static int calc_size(int namelen)
>+{
>+	int sz;
>+
>+	sz = sizeof(struct au_vdir_de) + namelen;
>+	if (sizeof(ino_t) == sizeof(long)) {
>+		const int mask = sizeof(ino_t) - 1;
>+		if (sz & mask) {
>+			sz += sizeof(ino_t);
>+			sz &= ~mask;
>+		}
>+	} else {
>+	}
>+
>+	AuDebugOn(sz % sizeof(ino_t));
>+	return sz;
>+}
>+
>+static int set_deblk_end(union au_vdir_deblk_p *p,
>+			 union au_vdir_deblk_p *deblk_end)
>+{
>+	if (calc_size(0) <= deblk_end->p - p->p) {
>+		p->de->de_str.len = 0;
>+		//smp_mb();
>+		return 0;
>+	}
>+	return -1; /* error */
>+}
>+
>+/* returns true or false */
>+static int is_deblk_end(union au_vdir_deblk_p *p,
>+			union au_vdir_deblk_p *deblk_end)
>+{
>+	if (calc_size(0) <= deblk_end->p - p->p)
>+		return !p->de->de_str.len;
>+	return 1;
>+}
>+
>+static au_vdir_deblk_t *last_deblk(struct au_vdir *vdir)
>+{
>+	return vdir->vd_deblk[vdir->vd_nblk - 1];
>+}
>+
>+void au_nhash_init(struct au_nhash *nhash)
>+{
>+	int i;
>+	for (i = 0; i < AuSize_NHASH; i++)
>+		INIT_HLIST_HEAD(nhash->heads + i);
>+}
>+
>+struct au_nhash *au_nhash_new(gfp_t gfp)
>+{
>+	struct au_nhash *nhash;
>+
>+	nhash = kmalloc(sizeof(*nhash), gfp);
>+	if (nhash) {
>+		au_nhash_init(nhash);
>+		return nhash;
>+	}
>+	return ERR_PTR(-ENOMEM);
>+}
>+
>+void au_nhash_del(struct au_nhash *nhash)
>+{
>+	au_nhash_fin(nhash);
>+	kfree(nhash);
>+}
>+
>+void au_nhash_move(struct au_nhash *dst, struct au_nhash *src)
>+{
>+	int i;
>+
>+	AuTraceEnter();
>+
>+	//DbgWhlist(src);
>+	*dst = *src;
>+	for (i = 0; i < AuSize_NHASH; i++) {
>+		struct hlist_head *h;
>+		h = dst->heads + i;
>+		if (h->first)
>+			h->first->pprev = &h->first;
>+		INIT_HLIST_HEAD(src->heads + i);
>+	}
>+	//DbgWhlist(src);
>+	//DbgWhlist(dst);
>+	//smp_mb();
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void au_nhash_fin(struct au_nhash *whlist)
>+{
>+	int i;
>+	struct hlist_head *head;
>+	struct au_vdir_wh *tpos;
>+	struct hlist_node *pos, *n;
>+
>+	AuTraceEnter();
>+
>+	for (i = 0; i < AuSize_NHASH; i++) {
>+		head = whlist->heads + i;
>+		hlist_for_each_entry_safe(tpos, pos, n, head, wh_hash) {
>+			//hlist_del(pos);
>+			kfree(tpos);
>+		}
>+	}
>+}
>+
>+int au_nhash_test_longer_wh(struct au_nhash *whlist, aufs_bindex_t btgt,
>+			    int limit)
>+{
>+	int n, i;
>+	struct hlist_head *head;
>+	struct au_vdir_wh *tpos;
>+	struct hlist_node *pos;
>+
>+	LKTRTrace("limit %d\n", limit);
>+	//return 1;
>+
>+	n = 0;
>+	for (i = 0; i < AuSize_NHASH; i++) {
>+		head = whlist->heads + i;
>+		hlist_for_each_entry(tpos, pos, head, wh_hash)
>+			if (tpos->wh_bindex == btgt && ++n > limit)
>+				return 1;
>+	}
>+	return 0;
>+}
>+
>+static unsigned int au_name_hash(const unsigned char *name, unsigned int len)
>+{
>+	return (full_name_hash(name, len) % AuSize_NHASH);
>+}
>+
>+/* returns found(true) or not */
>+int au_nhash_test_known_wh(struct au_nhash *whlist, char *name, int namelen)
>+{
>+	struct hlist_head *head;
>+	struct au_vdir_wh *tpos;
>+	struct hlist_node *pos;
>+	struct au_vdir_destr *str;
>+
>+	LKTRTrace("%.*s\n", namelen, name);
>+
>+	head = whlist->heads + au_name_hash(name, namelen);
>+	hlist_for_each_entry(tpos, pos, head, wh_hash) {
>+		str = &tpos->wh_str;
>+		LKTRTrace("%.*s\n", str->len, str->name);
>+		if (str->len == namelen && !memcmp(str->name, name, namelen))
>+			return 1;
>+	}
>+	return 0;
>+}
>+
>+int au_nhash_append_wh(struct au_nhash *whlist, char *name, int namelen,
>+		       ino_t ino, unsigned int d_type, aufs_bindex_t bindex,
>+		       unsigned char shwh)
>+{
>+	int err;
>+	struct au_vdir_destr *str;
>+	struct au_vdir_wh *wh;
>+
>+	LKTRTrace("%.*s\n", namelen, name);
>+
>+	err = -ENOMEM;
>+	wh = kmalloc(sizeof(*wh) + namelen, GFP_TEMPORARY);
>+	if (unlikely(!wh))
>+		goto out;
>+	err = 0;
>+	wh->wh_bindex = bindex;
>+	if (unlikely(shwh))
>+		au_shwh_init_wh(wh, ino, d_type);
>+	str = &wh->wh_str;
>+	str->len = namelen;
>+	memcpy(str->name, name, namelen);
>+	hlist_add_head(&wh->wh_hash,
>+		       whlist->heads + au_name_hash(name, namelen));
>+	//smp_mb();
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void au_vdir_free(struct au_vdir *vdir)
>+{
>+	au_vdir_deblk_t **deblk;
>+
>+	AuTraceEnter();
>+
>+	deblk = vdir->vd_deblk;
>+	while (vdir->vd_nblk--) {
>+		kfree(*deblk);
>+		deblk++;
>+	}
>+	kfree(vdir->vd_deblk);
>+	au_cache_free_vdir(vdir);
>+}
>+
>+static int append_deblk(struct au_vdir *vdir)
>+{
>+	int err, sz, i;
>+	au_vdir_deblk_t **o;
>+	union au_vdir_deblk_p p, deblk_end;
>+
>+	AuTraceEnter();
>+
>+	err = -ENOMEM;
>+	sz = sizeof(*o) * vdir->vd_nblk;
>+	o = au_kzrealloc(vdir->vd_deblk, sz, sz + sizeof(*o), GFP_KERNEL);
>+	if (unlikely(!o))
>+		goto out;
>+	vdir->vd_deblk = o;
>+	p.deblk = kmalloc(sizeof(*p.deblk), GFP_KERNEL);
>+	if (p.deblk) {
>+		i = vdir->vd_nblk++;
>+		vdir->vd_deblk[i] = p.deblk;
>+		vdir->vd_last.i = i;
>+		vdir->vd_last.p.p = p.p;
>+		deblk_end.deblk = p.deblk + 1;
>+		err = set_deblk_end(&p, &deblk_end);
>+		AuDebugOn(err);
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static struct au_vdir *alloc_vdir(void)
>+{
>+	struct au_vdir *vdir;
>+	int err;
>+
>+	AuTraceEnter();
>+
>+	err = -ENOMEM;
>+	vdir = au_cache_alloc_vdir();
>+	if (unlikely(!vdir))
>+		goto out;
>+	vdir->vd_deblk = kzalloc(sizeof(*vdir->vd_deblk), GFP_KERNEL);
>+	if (unlikely(!vdir->vd_deblk))
>+		goto out_free;
>+
>+	vdir->vd_nblk = 0;
>+	vdir->vd_version = 0;
>+	vdir->vd_jiffy = 0;
>+	err = append_deblk(vdir);
>+	if (!err)
>+		return vdir; /* success */
>+
>+	kfree(vdir->vd_deblk);
>+
>+ out_free:
>+	au_cache_free_vdir(vdir);
>+ out:
>+	vdir = ERR_PTR(err);
>+	AuTraceErrPtr(vdir);
>+	return vdir;
>+}
>+
>+static int reinit_vdir(struct au_vdir *vdir)
>+{
>+	int err;
>+	union au_vdir_deblk_p p, deblk_end;
>+
>+	AuTraceEnter();
>+
>+	while (vdir->vd_nblk > 1) {
>+		kfree(vdir->vd_deblk[vdir->vd_nblk - 1]);
>+		vdir->vd_deblk[vdir->vd_nblk - 1] = NULL;
>+		vdir->vd_nblk--;
>+	}
>+	p.deblk = vdir->vd_deblk[0];
>+	deblk_end.deblk = p.deblk + 1;
>+	err = set_deblk_end(&p, &deblk_end);
>+	AuDebugOn(err);
>+	vdir->vd_version = 0;
>+	vdir->vd_jiffy = 0;
>+	vdir->vd_last.i = 0;
>+	vdir->vd_last.p.deblk = vdir->vd_deblk[0];
>+	//smp_mb();
>+	//DbgVdir(vdir);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static void free_dehlist(struct au_nhash *dehlist)
>+{
>+	int i;
>+	struct hlist_head *head;
>+	struct au_vdir_dehstr *tpos;
>+	struct hlist_node *pos, *n;
>+
>+	AuTraceEnter();
>+
>+	for (i = 0; i < AuSize_NHASH; i++) {
>+		head = dehlist->heads + i;
>+		hlist_for_each_entry_safe(tpos, pos, n, head, hash) {
>+			//hlist_del(pos);
>+			au_cache_free_dehstr(tpos);
>+		}
>+	}
>+}
>+
>+/* returns found(true) or not */
>+static int test_known(struct au_nhash *delist, char *name, int namelen)
>+{
>+	struct hlist_head *head;
>+	struct au_vdir_dehstr *tpos;
>+	struct hlist_node *pos;
>+	struct au_vdir_destr *str;
>+
>+	LKTRTrace("%.*s\n", namelen, name);
>+
>+	head = delist->heads + au_name_hash(name, namelen);
>+	hlist_for_each_entry(tpos, pos, head, hash) {
>+		str = tpos->str;
>+		LKTRTrace("%.*s\n", str->len, str->name);
>+		if (str->len == namelen && !memcmp(str->name, name, namelen))
>+			return 1;
>+	}
>+	return 0;
>+
>+}
>+
>+static int append_de(struct au_vdir *vdir, char *name, int namelen, ino_t ino,
>+		     unsigned int d_type, struct au_nhash *delist)
>+{
>+	int err, sz;
>+	union au_vdir_deblk_p p, *room, deblk_end;
>+	struct au_vdir_dehstr *dehstr;
>+
>+	LKTRTrace("%.*s %d, i%lu, dt%u\n", namelen, name, namelen, ino, d_type);
>+
>+	p.deblk = last_deblk(vdir);
>+	deblk_end.deblk = p.deblk + 1;
>+	room = &vdir->vd_last.p;
>+	AuDebugOn(room->p < p.p || deblk_end.p <= room->p
>+		  || !is_deblk_end(room, &deblk_end));
>+
>+	sz = calc_size(namelen);
>+	if (unlikely(sz > deblk_end.p - room->p)) {
>+		err = append_deblk(vdir);
>+		if (unlikely(err))
>+			goto out;
>+		p.deblk = last_deblk(vdir);
>+		deblk_end.deblk = p.deblk + 1;
>+		//smp_mb();
>+		AuDebugOn(room->p != p.p);
>+	}
>+
>+	err = -ENOMEM;
>+	dehstr = au_cache_alloc_dehstr();
>+	if (unlikely(!dehstr))
>+		goto out;
>+	dehstr->str = &room->de->de_str;
>+	hlist_add_head(&dehstr->hash,
>+		       delist->heads + au_name_hash(name, namelen));
>+
>+	room->de->de_ino = ino;
>+	room->de->de_type = d_type;
>+	room->de->de_str.len = namelen;
>+	memcpy(room->de->de_str.name, name, namelen);
>+
>+	err = 0;
>+	room->p += sz;
>+	if (unlikely(set_deblk_end(room, &deblk_end)))
>+		err = append_deblk(vdir);
>+	//smp_mb();
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int au_ino(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
>+		  ino_t *ino)
>+{
>+	int err;
>+	struct au_xino_entry xinoe;
>+	static DEFINE_MUTEX(mtx);
>+
>+	/* a race condition for hardlinks */
>+	mutex_lock(&mtx);
>+	err = au_xino_read(sb, bindex, h_ino, &xinoe);
>+	if (unlikely(err))
>+		goto out;
>+
>+	if (!xinoe.ino) {
>+		//struct inode *h_inode;
>+		err = -EIO;
>+		xinoe.ino = au_xino_new_ino(sb);
>+		if (unlikely(!xinoe.ino))
>+			goto out;
>+		err = au_xino_write(sb, bindex, h_ino, &xinoe);
>+		if (unlikely(err))
>+			goto out;
>+	}
>+
>+	*ino = xinoe.ino;
>+
>+ out:
>+	mutex_unlock(&mtx);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int au_wh_ino(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
>+		     ino_t *ino)
>+{
>+#ifdef CONFIG_AUFS_SHWH
>+	return au_ino(sb, bindex, h_ino, ino);
>+#else
>+	return 0;
>+#endif
>+}
>+
>+#define AuFillVdir_CALLED	1
>+#define AuFillVdir_SHWH		(1 << 1)
>+#define au_ftest_fillvdir(flags, name)	((flags) & AuFillVdir_##name)
>+#define au_fset_fillvdir(flags, name)	{ (flags) |= AuFillVdir_##name; }
>+#define au_fclr_fillvdir(flags, name)	{ (flags) &= ~AuFillVdir_##name; }
>+#ifndef CONFIG_AUFS_SHWH
>+#undef AuFillVdir_SHWH
>+#define AuFillVdir_SHWH		0
>+#endif
>+
>+struct fillvdir_arg {
>+	struct file		*file;
>+	struct au_vdir 	*vdir;
>+	struct au_nhash	*delist;
>+	struct au_nhash	*whlist;
>+	aufs_bindex_t		bindex;
>+	unsigned int		flags;
>+	int			err;
>+};
>+
>+static int fillvdir(void *__arg, const char *__name, int namelen, loff_t offset,
>+		    u64 h_ino, unsigned int d_type)
>+{
>+	struct fillvdir_arg *arg = __arg;
>+	char *name = (void *)__name;
>+	aufs_bindex_t bindex, bend;
>+	struct super_block *sb;
>+	ino_t ino;
>+
>+	LKTRTrace("%.*s, namelen %d, i%Lu, dt%u\n",
>+		  namelen, name, namelen, (u64)h_ino, d_type);
>+
>+	sb = arg->file->f_dentry->d_sb;
>+	bend = arg->bindex;
>+	arg->err = 0;
>+	au_fset_fillvdir(arg->flags, CALLED);
>+	//smp_mb();
>+	if (namelen <= AUFS_WH_PFX_LEN
>+	    || memcmp(name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
>+		for (bindex = 0; bindex < bend; bindex++)
>+			if (test_known(arg->delist + bindex, name, namelen)
>+			    || au_nhash_test_known_wh(arg->whlist + bindex,
>+						      name, namelen))
>+				goto out; /* already exists or whiteouted */
>+
>+		ino = 1; /* why does gcc warns? */
>+		arg->err = au_ino(sb, bend, h_ino, &ino);
>+		if (!arg->err)
>+			arg->err = append_de(arg->vdir, name, namelen, ino,
>+					     d_type, arg->delist + bend);
>+	} else {
>+		name += AUFS_WH_PFX_LEN;
>+		namelen -= AUFS_WH_PFX_LEN;
>+		for (bindex = 0; bindex < bend; bindex++)
>+			if (au_nhash_test_known_wh(arg->whlist + bend, name,
>+						   namelen))
>+				goto out; /* already whiteouted */
>+
>+		ino = 1; /* dummy */
>+		if (unlikely(au_ftest_fillvdir(arg->flags, SHWH)))
>+			arg->err = au_wh_ino(sb, bend, h_ino, &ino);
>+		if (!arg->err)
>+			arg->err = au_nhash_append_wh
>+				(arg->whlist + bend, name, namelen, ino, d_type,
>+				 bend, au_ftest_fillvdir(arg->flags, SHWH));
>+	}
>+
>+ out:
>+	if (!arg->err)
>+		arg->vdir->vd_jiffy = jiffies;
>+	//smp_mb();
>+	AuTraceErr(arg->err);
>+	return arg->err;
>+}
>+
>+static int au_handle_shwh(struct super_block *sb, struct au_vdir *vdir,
>+			  aufs_bindex_t bstart, aufs_bindex_t bend,
>+			  struct au_nhash *_whlist, struct au_nhash *_delist)
>+{
>+#ifdef CONFIG_AUFS_SHWH
>+	int err, i;
>+	struct hlist_head *head;
>+	struct au_vdir_wh *tpos;
>+	struct hlist_node *pos, *n;
>+	char *p, *o;
>+	struct au_nhash *whlist, *delist;
>+	struct au_vdir_destr *destr;
>+	aufs_bindex_t bindex;
>+
>+	AuTraceEnter();
>+	AuDebugOn(!au_opt_test(au_mntflags(sb), SHWH));
>+
>+	err = -ENOMEM;
>+	o = p = __getname();
>+	if (unlikely(!p))
>+		goto out;
>+
>+	err = 0;
>+	memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
>+	p += AUFS_WH_PFX_LEN;
>+	for (bindex = bstart; !err && bindex <= bend; bindex++) {
>+		whlist = _whlist + bindex;
>+		delist = _delist + bindex;
>+
>+		for (i = 0; i < AuSize_NHASH; i++) {
>+			head = whlist->heads + i;
>+			hlist_for_each_entry_safe(tpos, pos, n, head, wh_hash) {
>+				destr = &tpos->wh_str;
>+				memcpy(p, destr->name, destr->len);
>+				err = append_de(vdir, o,
>+						destr->len + AUFS_WH_PFX_LEN,
>+						tpos->wh_ino, tpos->wh_type,
>+						delist);
>+				if (unlikely(err))
>+					break;
>+			}
>+		}
>+	}
>+
>+	__putname(o);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+#else
>+	return 0;
>+#endif
>+}
>+
>+static int au_do_read_vdir(struct fillvdir_arg *arg)
>+{
>+	int err, dlgt, shwh;
>+	aufs_bindex_t bend, bindex, bstart;
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+	struct file *hf;
>+	loff_t offset;
>+
>+	AuTraceEnter();
>+
>+	err = -ENOMEM;
>+	bend = au_fbend(arg->file);
>+	arg->delist = kmalloc(sizeof(*arg->delist) * (bend + 1), GFP_TEMPORARY);
>+	if (unlikely(!arg->delist))
>+		goto out;
>+	arg->whlist = kmalloc(sizeof(*arg->whlist) * (bend + 1), GFP_TEMPORARY);
>+	if (unlikely(!arg->whlist))
>+		goto out_delist;
>+	err = 0;
>+	for (bindex = 0; bindex <= bend; bindex++) {
>+		au_nhash_init(arg->delist + bindex);
>+		au_nhash_init(arg->whlist + bindex);
>+	}
>+
>+	sb = arg->file->f_dentry->d_sb;
>+	mnt_flags = au_mntflags(sb);
>+	dlgt = !!au_opt_test_dlgt(mnt_flags);
>+	arg->flags = 0;
>+	shwh = 0;
>+	if (unlikely(au_opt_test(mnt_flags, SHWH))) {
>+		shwh = 1;
>+		au_fset_fillvdir(arg->flags, SHWH);
>+	}
>+	bstart = au_fbstart(arg->file);
>+	for (bindex = bstart; !err && bindex <= bend; bindex++) {
>+		hf = au_h_fptr(arg->file, bindex);
>+		if (!hf)
>+			continue;
>+
>+		offset = vfsub_llseek(hf, 0, SEEK_SET);
>+		err = offset;
>+		if (unlikely(offset))
>+			break;
>+		arg->bindex = bindex;
>+		do {
>+			arg->err = 0;
>+			au_fclr_fillvdir(arg->flags, CALLED);
>+			//smp_mb();
>+			err = vfsub_readdir(hf, fillvdir, arg, dlgt);
>+			if (err >= 0)
>+				err = arg->err;
>+		} while (!err && au_ftest_fillvdir(arg->flags, CALLED));
>+	}
>+
>+	if (unlikely(!err && shwh))
>+		err = au_handle_shwh(sb, arg->vdir, bstart, bend, arg->whlist,
>+				     arg->delist);
>+
>+	for (bindex = bstart; bindex <= bend; bindex++) {
>+		free_dehlist(arg->delist + bindex);
>+		au_nhash_fin(arg->whlist + bindex);
>+	}
>+	kfree(arg->whlist);
>+
>+ out_delist:
>+	kfree(arg->delist);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int read_vdir(struct file *file, int may_read)
>+{
>+	int err, do_read;
>+	struct dentry *dentry;
>+	struct inode *inode;
>+	struct au_vdir *vdir, *allocated;
>+	unsigned long expire;
>+	struct fillvdir_arg arg;
>+	struct super_block *sb;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, may %d\n", AuDLNPair(dentry), may_read);
>+	FiMustWriteLock(file);
>+	inode = dentry->d_inode;
>+	IMustLock(inode);
>+	IiMustWriteLock(inode);
>+	AuDebugOn(!S_ISDIR(inode->i_mode));
>+
>+	err = 0;
>+	allocated = NULL;
>+	do_read = 0;
>+	sb = inode->i_sb;
>+	expire = au_sbi(sb)->si_rdcache;
>+	vdir = au_ivdir(inode);
>+	if (!vdir) {
>+		AuDebugOn(au_fvdir_cache(file));
>+		do_read = 1;
>+		vdir = alloc_vdir();
>+		err = PTR_ERR(vdir);
>+		if (IS_ERR(vdir))
>+			goto out;
>+		err = 0;
>+		allocated = vdir;
>+	} else if (may_read
>+		   && (inode->i_version != vdir->vd_version
>+		       || time_after(jiffies, vdir->vd_jiffy + expire))) {
>+		LKTRTrace("iver %Lu, vdver %lu, exp %lu\n",
>+			  inode->i_version, vdir->vd_version,
>+			  vdir->vd_jiffy + expire);
>+		do_read = 1;
>+		err = reinit_vdir(vdir);
>+		if (unlikely(err))
>+			goto out;
>+	}
>+	//AuDbgVdir(vdir); goto out;
>+
>+	if (!do_read)
>+		return 0; /* success */
>+
>+	arg.file = file;
>+	arg.vdir = vdir;
>+	err = au_do_read_vdir(&arg);
>+	if (!err) {
>+		//file->f_pos = 0;
>+		vdir->vd_version = inode->i_version;
>+		vdir->vd_last.i = 0;
>+		vdir->vd_last.p.deblk = vdir->vd_deblk[0];
>+		if (allocated)
>+			au_set_ivdir(inode, allocated);
>+		//AuDbgVdir(vdir);
>+	} else if (allocated)
>+		au_vdir_free(allocated);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int copy_vdir(struct au_vdir *tgt, struct au_vdir *src)
>+{
>+	int err, i, rerr, n;
>+
>+	AuTraceEnter();
>+	AuDebugOn(tgt->vd_nblk != 1);
>+	//AuDbgVdir(tgt);
>+
>+	err = -ENOMEM;
>+	if (tgt->vd_nblk < src->vd_nblk) {
>+		au_vdir_deblk_t **p;
>+		p = au_kzrealloc(tgt->vd_deblk, sizeof(*p) * tgt->vd_nblk,
>+				 sizeof(*p) * src->vd_nblk, GFP_KERNEL);
>+		if (unlikely(!p))
>+			goto out;
>+		tgt->vd_deblk = p;
>+	}
>+
>+	tgt->vd_nblk = src->vd_nblk;
>+	n = src->vd_nblk;
>+	memcpy(tgt->vd_deblk[0], src->vd_deblk[0], AuSize_DEBLK);
>+	//tgt->vd_last.i = 0;
>+	//tgt->vd_last.p.deblk = tgt->vd_deblk[0];
>+	tgt->vd_version = src->vd_version;
>+	tgt->vd_jiffy = src->vd_jiffy;
>+
>+	for (i = 1; i < n; i++) {
>+		tgt->vd_deblk[i] = kmalloc(AuSize_DEBLK, GFP_KERNEL);
>+		if (tgt->vd_deblk[i])
>+			memcpy(tgt->vd_deblk[i], src->vd_deblk[i],
>+			       AuSize_DEBLK);
>+		else
>+			goto out;
>+	}
>+	//smp_mb();
>+	//AuDbgVdir(tgt);
>+	return 0; /* success */
>+
>+ out:
>+	rerr = reinit_vdir(tgt);
>+	BUG_ON(rerr);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_vdir_init(struct file *file)
>+{
>+	int err;
>+	struct dentry *dentry;
>+	struct inode *inode;
>+	struct au_vdir *vdir_cache, *allocated;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, pos %Ld\n", AuDLNPair(dentry), file->f_pos);
>+	FiMustWriteLock(file);
>+	inode = dentry->d_inode;
>+	IiMustWriteLock(inode);
>+	AuDebugOn(!S_ISDIR(inode->i_mode));
>+
>+	err = read_vdir(file, !file->f_pos);
>+	if (unlikely(err))
>+		goto out;
>+	//AuDbgVdir(au_ivdir(inode)); goto out;
>+
>+	allocated = NULL;
>+	vdir_cache = au_fvdir_cache(file);
>+	if (!vdir_cache) {
>+		vdir_cache = alloc_vdir();
>+		err = PTR_ERR(vdir_cache);
>+		if (IS_ERR(vdir_cache))
>+			goto out;
>+		allocated = vdir_cache;
>+	} else if (!file->f_pos && vdir_cache->vd_version != file->f_version) {
>+		err = reinit_vdir(vdir_cache);
>+		if (unlikely(err))
>+			goto out;
>+	} else
>+		return 0; /* success */
>+	//err = 0; AuDbgVdir(vdir_cache); goto out;
>+
>+	err = copy_vdir(vdir_cache, au_ivdir(inode));
>+	if (!err) {
>+		file->f_version = inode->i_version;
>+		if (allocated)
>+			au_set_fvdir_cache(file, allocated);
>+	} else if (allocated)
>+		au_vdir_free(allocated);
>+
>+ out:
>+	//au_debug_on();
>+	AuTraceErr(err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+static loff_t calc_offset(struct au_vdir *vdir)
>+{
>+	loff_t offset;
>+	union au_vdir_deblk_p p;
>+
>+	p.deblk = vdir->vd_deblk[vdir->vd_last.i];
>+	offset = vdir->vd_last.p.p - p.p;
>+	offset += sizeof(*p.deblk) * vdir->vd_last.i;
>+	return offset;
>+}
>+
>+/* returns true or false */
>+static int seek_vdir(struct file *file)
>+{
>+	int valid, i, n;
>+	struct dentry *dentry;
>+	struct au_vdir *vdir_cache;
>+	loff_t offset;
>+	union au_vdir_deblk_p p, deblk_end;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, pos %Ld\n", AuDLNPair(dentry), file->f_pos);
>+	vdir_cache = au_fvdir_cache(file);
>+	AuDebugOn(!vdir_cache);
>+	//AuDbgVdir(vdir_cache);
>+
>+	valid = 1;
>+	offset = calc_offset(vdir_cache);
>+	LKTRTrace("offset %Ld\n", offset);
>+	if (file->f_pos == offset)
>+		goto out;
>+
>+	vdir_cache->vd_last.i = 0;
>+	vdir_cache->vd_last.p.deblk = vdir_cache->vd_deblk[0];
>+	if (!file->f_pos)
>+		goto out;
>+
>+	valid = 0;
>+	i = file->f_pos / AuSize_DEBLK;
>+	LKTRTrace("i %d\n", i);
>+	if (i >= vdir_cache->vd_nblk)
>+		goto out;
>+
>+	n = vdir_cache->vd_nblk;
>+	for (; i < n; i++) {
>+		p.deblk = vdir_cache->vd_deblk[i];
>+		deblk_end.deblk = p.deblk + 1;
>+		offset = i;
>+		offset *= AuSize_DEBLK;
>+		while (!is_deblk_end(&p, &deblk_end) && offset < file->f_pos) {
>+			int l;
>+			l = calc_size(p.de->de_str.len);
>+			offset += l;
>+			p.p += l;
>+		}
>+		if (!is_deblk_end(&p, &deblk_end)) {
>+			valid = 1;
>+			vdir_cache->vd_last.i = i;
>+			vdir_cache->vd_last.p = p;
>+			break;
>+		}
>+	}
>+
>+ out:
>+	//smp_mb();
>+	AuTraceErr(!valid);
>+	return valid;
>+}
>+
>+int au_vdir_fill_de(struct file *file, void *dirent, filldir_t filldir)
>+{
>+	int err, l;
>+	struct dentry *dentry;
>+	struct au_vdir *vdir_cache;
>+	struct au_vdir_de *de;
>+	union au_vdir_deblk_p deblk_end;
>+
>+	dentry = file->f_dentry;
>+	LKTRTrace("%.*s, pos %Ld\n", AuDLNPair(dentry), file->f_pos);
>+	vdir_cache = au_fvdir_cache(file);
>+	AuDebugOn(!vdir_cache);
>+	//AuDbgVdir(vdir_cache);
>+
>+	if (!seek_vdir(file))
>+		return 0;
>+
>+	while (1) {
>+		deblk_end.deblk
>+			= vdir_cache->vd_deblk[vdir_cache->vd_last.i] + 1;
>+		while (!is_deblk_end(&vdir_cache->vd_last.p, &deblk_end)) {
>+			de = vdir_cache->vd_last.p.de;
>+			LKTRTrace("%.*s, off%Ld, i%lu, dt%d\n",
>+				  de->de_str.len, de->de_str.name,
>+				  file->f_pos, de->de_ino, de->de_type);
>+			err = filldir(dirent, de->de_str.name, de->de_str.len,
>+				      file->f_pos, de->de_ino, de->de_type);
>+			if (unlikely(err)) {
>+				AuTraceErr(err);
>+				//return err;
>+				//todo: ignore the error caused by udba.
>+				return 0;
>+			}
>+
>+			l = calc_size(de->de_str.len);
>+			vdir_cache->vd_last.p.p += l;
>+			file->f_pos += l;
>+		}
>+		if (vdir_cache->vd_last.i < vdir_cache->vd_nblk - 1) {
>+			vdir_cache->vd_last.i++;
>+			vdir_cache->vd_last.p.deblk
>+				= vdir_cache->vd_deblk[vdir_cache->vd_last.i];
>+			file->f_pos = sizeof(*vdir_cache->vd_last.p.deblk)
>+				* vdir_cache->vd_last.i;
>+			continue;
>+		}
>+		break;
>+	}
>+
>+	//smp_mb();
>+	return 0;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/vfsub.c linux-2.6.25.4-unionfs/fs/aufs/vfsub.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/vfsub.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/vfsub.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,642 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * sub-routines for VFS
>+ *
>+ * $Id: vfsub.c,v 1.3 2008/05/12 00:29:11 sfjro Exp $
>+ */
>+// I'm going to slightly mad
>+
>+#include <linux/uaccess.h>
>+#include "aufs.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void vfsub_args_init(struct vfsub_args *vargs, struct au_hin_ignore *ign,
>+		     int dlgt, int force_unlink)
>+{
>+	do_vfsub_args_reinit(vargs, ign);
>+	vargs->flags = 0;
>+	if (unlikely(dlgt))
>+		vfsub_fset(vargs->flags, DLGT);
>+	if (force_unlink)
>+		vfsub_fset(vargs->flags, FORCE_UNLINK);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct file *vfsub_filp_open(const char *path, int oflags, int mode)
>+{
>+	struct file *err;
>+
>+	LKTRTrace("%s\n", path);
>+
>+	lockdep_off();
>+	err = filp_open(path, oflags, mode);
>+	lockdep_on();
>+	if (!IS_ERR(err))
>+		au_update_fuse_h_inode(err->f_vfsmnt, err->f_dentry); /*ignore*/
>+	return err;
>+}
>+
>+int vfsub_path_lookup(const char *name, unsigned int flags,
>+		      struct nameidata *nd)
>+{
>+	int err;
>+
>+	LKTRTrace("%s\n", name);
>+
>+	/* lockdep_off(); */
>+	err = path_lookup(name, flags, nd);
>+	/* lockdep_on(); */
>+	if (!err)
>+		au_update_fuse_h_inode(nd->path.mnt, nd->path.dentry);
>+	/*ignore*/
>+	return err;
>+}
>+
>+struct dentry *vfsub_lookup_one_len(const char *name, struct dentry *parent,
>+				    int len)
>+{
>+	struct dentry *d;
>+
>+	LKTRTrace("%.*s/%.*s\n", AuDLNPair(parent), len, name);
>+	IMustLock(parent->d_inode);
>+
>+	d = lookup_one_len(name, parent, len);
>+	if (!IS_ERR(d))
>+		au_update_fuse_h_inode(NULL, d); /*ignore*/
>+	return d;
>+}
>+
>+#ifdef CONFIG_AUFS_LHASH_PATCH
>+struct dentry *vfsub__lookup_hash(struct qstr *name, struct dentry *parent,
>+				  struct nameidata *nd)
>+{
>+	struct dentry *d;
>+
>+	LKTRTrace("%.*s/%.*s, nd %d\n",
>+		  AuDLNPair(parent), AuLNPair(name), !!nd);
>+	if (nd)
>+		LKTRTrace("nd{0x%x}\n", nd->flags);
>+	IMustLock(parent->d_inode);
>+
>+	d = __lookup_hash(name, parent, nd);
>+	if (!IS_ERR(d))
>+		au_update_fuse_h_inode(NULL, d); /*ignore*/
>+	return d;
>+}
>+#endif
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int do_vfsub_create(struct inode *dir, struct dentry *dentry, int mode,
>+		    struct nameidata *nd)
>+{
>+	int err;
>+	struct vfsmount *mnt;
>+
>+	LKTRTrace("i%lu, %.*s, 0x%x\n", dir->i_ino, AuDLNPair(dentry), mode);
>+	IMustLock(dir);
>+
>+	err = vfs_create(dir, dentry, mode, nd);
>+	if (!err) {
>+		mnt = NULL;
>+		if (nd)
>+			mnt = nd->path.mnt;
>+		/* dir inode is locked */
>+		au_update_fuse_h_inode(mnt, dentry->d_parent); /*ignore*/
>+		au_update_fuse_h_inode(mnt, dentry); /*ignore*/
>+	}
>+	return err;
>+}
>+
>+int do_vfsub_symlink(struct inode *dir, struct dentry *dentry,
>+		     const char *symname, int mode)
>+{
>+	int err;
>+
>+	LKTRTrace("i%lu, %.*s, %s, 0x%x\n",
>+		  dir->i_ino, AuDLNPair(dentry), symname, mode);
>+	IMustLock(dir);
>+
>+	err = vfs_symlink(dir, dentry, symname, mode);
>+	if (!err) {
>+		/* dir inode is locked */
>+		au_update_fuse_h_inode(NULL, dentry->d_parent); /*ignore*/
>+		au_update_fuse_h_inode(NULL, dentry); /*ignore*/
>+	}
>+	return err;
>+}
>+
>+int do_vfsub_mknod(struct inode *dir, struct dentry *dentry, int mode,
>+		   dev_t dev)
>+{
>+	int err;
>+
>+	LKTRTrace("i%lu, %.*s, 0x%x\n", dir->i_ino, AuDLNPair(dentry), mode);
>+	IMustLock(dir);
>+
>+	err = vfs_mknod(dir, dentry, mode, dev);
>+	if (!err) {
>+		/* dir inode is locked */
>+		au_update_fuse_h_inode(NULL, dentry->d_parent); /*ignore*/
>+		au_update_fuse_h_inode(NULL, dentry); /*ignore*/
>+	}
>+	return err;
>+}
>+
>+int do_vfsub_link(struct dentry *src_dentry, struct inode *dir,
>+		  struct dentry *dentry)
>+{
>+	int err;
>+
>+	LKTRTrace("%.*s, i%lu, %.*s\n",
>+		  AuDLNPair(src_dentry), dir->i_ino, AuDLNPair(dentry));
>+	IMustLock(dir);
>+
>+	lockdep_off();
>+	err = vfs_link(src_dentry, dir, dentry);
>+	lockdep_on();
>+	if (!err) {
>+		LKTRTrace("src_i %p, dst_i %p\n",
>+			  src_dentry->d_inode, dentry->d_inode);
>+		/* fuse has different memory inode for the same inumber */
>+		au_update_fuse_h_inode(NULL, src_dentry); /*ignore*/
>+		/* dir inode is locked */
>+		au_update_fuse_h_inode(NULL, dentry->d_parent); /*ignore*/
>+		au_update_fuse_h_inode(NULL, dentry); /*ignore*/
>+	}
>+	return err;
>+}
>+
>+int do_vfsub_rename(struct inode *src_dir, struct dentry *src_dentry,
>+		    struct inode *dir, struct dentry *dentry)
>+{
>+	int err;
>+
>+	LKTRTrace("i%lu, %.*s, i%lu, %.*s\n",
>+		  src_dir->i_ino, AuDLNPair(src_dentry),
>+		  dir->i_ino, AuDLNPair(dentry));
>+	IMustLock(dir);
>+	IMustLock(src_dir);
>+
>+	lockdep_off();
>+	err = vfs_rename(src_dir, src_dentry, dir, dentry);
>+	lockdep_on();
>+	if (!err) {
>+		/* dir inode is locked */
>+		au_update_fuse_h_inode(NULL, dentry->d_parent); /*ignore*/
>+		au_update_fuse_h_inode(NULL, src_dentry->d_parent); /*ignore*/
>+		au_update_fuse_h_inode(NULL, src_dentry); /*ignore*/
>+	}
>+	return err;
>+}
>+
>+int do_vfsub_mkdir(struct inode *dir, struct dentry *dentry, int mode)
>+{
>+	int err;
>+
>+	LKTRTrace("i%lu, %.*s, 0x%x\n", dir->i_ino, AuDLNPair(dentry), mode);
>+	IMustLock(dir);
>+
>+	err = vfs_mkdir(dir, dentry, mode);
>+	if (!err) {
>+		/* dir inode is locked */
>+		au_update_fuse_h_inode(NULL, dentry->d_parent); /*ignore*/
>+		au_update_fuse_h_inode(NULL, dentry); /*ignore*/
>+	}
>+	return err;
>+}
>+
>+int do_vfsub_rmdir(struct inode *dir, struct dentry *dentry)
>+{
>+	int err;
>+
>+	LKTRTrace("i%lu, %.*s\n", dir->i_ino, AuDLNPair(dentry));
>+	IMustLock(dir);
>+
>+	lockdep_off();
>+	err = vfs_rmdir(dir, dentry);
>+	lockdep_on();
>+	/* dir inode is locked */
>+	if (!err)
>+		au_update_fuse_h_inode(NULL, dentry->d_parent); /*ignore*/
>+	return err;
>+}
>+
>+int do_vfsub_unlink(struct inode *dir, struct dentry *dentry)
>+{
>+	int err;
>+
>+	LKTRTrace("i%lu, %.*s\n", dir->i_ino, AuDLNPair(dentry));
>+	IMustLock(dir);
>+
>+	/* vfs_unlink() locks inode */
>+	lockdep_off();
>+	err = vfs_unlink(dir, dentry);
>+	lockdep_on();
>+	/* dir inode is locked */
>+	if (!err)
>+		au_update_fuse_h_inode(NULL, dentry->d_parent); /*ignore*/
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+ssize_t do_vfsub_read_u(struct file *file, char __user *ubuf, size_t count,
>+			loff_t *ppos)
>+{
>+	ssize_t err;
>+
>+	LKTRTrace("%.*s, cnt %lu, pos %Ld\n",
>+		  AuDLNPair(file->f_dentry), (unsigned long)count, *ppos);
>+
>+	if (0 /*!au_test_nfs(file->f_vfsmnt->mnt_sb)*/)
>+		err = vfs_read(file, ubuf, count, ppos);
>+	else {
>+		lockdep_off();
>+		err = vfs_read(file, ubuf, count, ppos);
>+		lockdep_on();
>+	}
>+	if (err >= 0)
>+		au_update_fuse_h_inode(file->f_vfsmnt, file->f_dentry);
>+	/*ignore*/
>+	return err;
>+}
>+
>+// kernel_read() ??
>+ssize_t do_vfsub_read_k(struct file *file, void *kbuf, size_t count,
>+			loff_t *ppos)
>+{
>+	ssize_t err;
>+	mm_segment_t oldfs;
>+
>+	oldfs = get_fs();
>+	set_fs(KERNEL_DS);
>+	err = do_vfsub_read_u(file, (char __user *)kbuf, count, ppos);
>+	set_fs(oldfs);
>+	return err;
>+}
>+
>+ssize_t do_vfsub_write_u(struct file *file, const char __user *ubuf,
>+			 size_t count, loff_t *ppos)
>+{
>+	ssize_t err;
>+
>+	LKTRTrace("%.*s, cnt %lu, pos %Ld\n",
>+		  AuDLNPair(file->f_dentry), (unsigned long)count, *ppos);
>+
>+	lockdep_off();
>+	err = vfs_write(file, ubuf, count, ppos);
>+	lockdep_on();
>+	if (err >= 0)
>+		au_update_fuse_h_inode(file->f_vfsmnt, file->f_dentry);
>+	/*ignore*/
>+	return err;
>+}
>+
>+ssize_t do_vfsub_write_k(struct file *file, void *kbuf, size_t count,
>+			 loff_t *ppos)
>+{
>+	ssize_t err;
>+	mm_segment_t oldfs;
>+
>+	oldfs = get_fs();
>+	set_fs(KERNEL_DS);
>+	err = do_vfsub_write_u(file, (const char __user *)kbuf, count, ppos);
>+	set_fs(oldfs);
>+	return err;
>+}
>+
>+int do_vfsub_readdir(struct file *file, filldir_t filldir, void *arg)
>+{
>+	int err;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(file->f_dentry));
>+
>+	lockdep_off();
>+	err = vfs_readdir(file, filldir, arg);
>+	lockdep_on();
>+	if (err >= 0)
>+		au_update_fuse_h_inode(file->f_vfsmnt, file->f_dentry);
>+	/*ignore*/
>+	return err;
>+}
>+
>+#ifdef CONFIG_AUFS_SPLICE_PATCH
>+long do_vfsub_splice_to(struct file *in, loff_t *ppos,
>+			struct pipe_inode_info *pipe, size_t len,
>+			unsigned int flags)
>+{
>+	long err;
>+
>+	LKTRTrace("%.*s, pos %Ld, len %lu, 0x%x\n",
>+		  AuDLNPair(in->f_dentry), *ppos, (unsigned long)len, flags);
>+
>+	lockdep_off();
>+	err = vfs_splice_to(in, ppos, pipe, len, flags);
>+	lockdep_on();
>+	if (err >= 0)
>+		au_update_fuse_h_inode(in->f_vfsmnt, in->f_dentry); /*ignore*/
>+	return err;
>+}
>+
>+long do_vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
>+			  loff_t *ppos, size_t len, unsigned int flags)
>+{
>+	long err;
>+
>+	LKTRTrace("%.*s, pos %Ld, len %lu, 0x%x\n",
>+		  AuDLNPair(out->f_dentry), *ppos, (unsigned long)len, flags);
>+
>+	lockdep_off();
>+	err = vfs_splice_from(pipe, out, ppos, len, flags);
>+	lockdep_on();
>+	if (err >= 0)
>+		au_update_fuse_h_inode(out->f_vfsmnt, out->f_dentry); /*ignore*/
>+	return err;
>+}
>+#endif
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_vfsub_mkdir_args {
>+	int *errp;
>+	struct inode *dir;
>+	struct dentry *dentry;
>+	int mode;
>+	int dlgt;
>+};
>+
>+static void au_call_vfsub_mkdir(void *args)
>+{
>+	struct au_vfsub_mkdir_args *a = args;
>+	*a->errp = vfsub_mkdir(a->dir, a->dentry, a->mode, a->dlgt);
>+}
>+
>+int vfsub_sio_mkdir(struct inode *dir, struct dentry *dentry, int mode,
>+		    int dlgt)
>+{
>+	int err, do_sio, wkq_err;
>+
>+	LKTRTrace("i%lu, %.*s\n", dir->i_ino, AuDLNPair(dentry));
>+
>+	do_sio = au_test_h_perm_sio(dir, MAY_EXEC | MAY_WRITE, dlgt);
>+	if (!do_sio)
>+		err = vfsub_mkdir(dir, dentry, mode, dlgt);
>+	else {
>+		struct au_vfsub_mkdir_args args = {
>+			.errp	= &err,
>+			.dir	= dir,
>+			.dentry	= dentry,
>+			.mode	= mode,
>+			.dlgt	= dlgt
>+		};
>+		wkq_err = au_wkq_wait(au_call_vfsub_mkdir, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+struct au_vfsub_rmdir_args {
>+	int *errp;
>+	struct inode *dir;
>+	struct dentry *dentry;
>+	struct vfsub_args *vargs;
>+};
>+
>+static void au_call_vfsub_rmdir(void *args)
>+{
>+	struct au_vfsub_rmdir_args *a = args;
>+	*a->errp = vfsub_rmdir(a->dir, a->dentry, a->vargs);
>+}
>+
>+int vfsub_sio_rmdir(struct inode *dir, struct dentry *dentry, int dlgt)
>+{
>+	int err, do_sio, wkq_err;
>+	struct vfsub_args vargs;
>+
>+	LKTRTrace("i%lu, %.*s\n", dir->i_ino, AuDLNPair(dentry));
>+
>+	vfsub_args_init(&vargs, /*ign*/NULL, dlgt, /*force_unlink*/0);
>+	do_sio = au_test_h_perm_sio(dir, MAY_EXEC | MAY_WRITE, dlgt);
>+	if (!do_sio)
>+		err = vfsub_rmdir(dir, dentry, &vargs);
>+	else {
>+		struct au_vfsub_rmdir_args args = {
>+			.errp		= &err,
>+			.dir		= dir,
>+			.dentry		= dentry,
>+			.vargs		= &vargs
>+		};
>+		wkq_err = au_wkq_wait(au_call_vfsub_rmdir, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct notify_change_args {
>+	int *errp;
>+	struct dentry *h_dentry;
>+	struct iattr *ia;
>+	struct vfsub_args *vargs;
>+};
>+
>+static void call_notify_change(void *args)
>+{
>+	struct notify_change_args *a = args;
>+	struct inode *h_inode;
>+
>+	LKTRTrace("%.*s, ia_valid 0x%x\n",
>+		  AuDLNPair(a->h_dentry), a->ia->ia_valid);
>+	h_inode = a->h_dentry->d_inode;
>+	IMustLock(h_inode);
>+
>+	*a->errp = -EPERM;
>+	if (!IS_IMMUTABLE(h_inode) && !IS_APPEND(h_inode)) {
>+		vfsub_ignore(a->vargs);
>+		lockdep_off();
>+		*a->errp = notify_change(a->h_dentry, a->ia);
>+		lockdep_on();
>+		if (!*a->errp)
>+			au_update_fuse_h_inode(NULL, a->h_dentry); /*ignore*/
>+		else
>+			vfsub_unignore(a->vargs);
>+	}
>+	AuTraceErr(*a->errp);
>+}
>+
>+#ifdef CONFIG_AUFS_DLGT
>+static void vfsub_notify_change_dlgt(struct notify_change_args *args,
>+				     unsigned int flags)
>+{
>+	if (!vfsub_ftest(flags, DLGT))
>+		call_notify_change(args);
>+	else {
>+		int wkq_err;
>+		wkq_err = au_wkq_wait(call_notify_change, args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			*args->errp = wkq_err;
>+	}
>+}
>+#else
>+static void vfsub_notify_change_dlgt(struct notify_change_args *args,
>+				     unsigned int flags)
>+{
>+	call_notify_change(args);
>+}
>+#endif
>+
>+int vfsub_notify_change(struct dentry *dentry, struct iattr *ia,
>+			struct vfsub_args *vargs)
>+{
>+	int err;
>+	struct notify_change_args args = {
>+		.errp		= &err,
>+		.h_dentry	= dentry,
>+		.ia		= ia,
>+		.vargs		= vargs
>+	};
>+
>+	vfsub_notify_change_dlgt(&args, vargs->flags);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct unlink_args {
>+	int *errp;
>+	struct inode *dir;
>+	struct dentry *dentry;
>+	struct vfsub_args *vargs;
>+};
>+
>+static void call_unlink(void *args)
>+{
>+	struct unlink_args *a = args;
>+	struct inode *h_inode;
>+	const int stop_sillyrename = (au_test_nfs(a->dentry->d_sb)
>+				      && atomic_read(&a->dentry->d_count) == 1);
>+
>+	LKTRTrace("%.*s, stop_silly %d, cnt %d\n",
>+		  AuDLNPair(a->dentry), stop_sillyrename,
>+		  atomic_read(&a->dentry->d_count));
>+	//IMustLock(a->dir);
>+
>+	if (!stop_sillyrename)
>+		dget(a->dentry);
>+	h_inode = a->dentry->d_inode;
>+	if (h_inode)
>+		atomic_inc_return(&h_inode->i_count);
>+	*a->errp = do_vfsub_unlink(a->dir, a->dentry);
>+
>+	if (!stop_sillyrename)
>+		dput(a->dentry);
>+	if (h_inode)
>+		iput(h_inode);
>+
>+	AuTraceErr(*a->errp);
>+}
>+
>+/*
>+ * @dir: must be locked.
>+ * @dentry: target dentry.
>+ */
>+int vfsub_unlink(struct inode *dir, struct dentry *dentry,
>+		 struct vfsub_args *vargs)
>+{
>+	int err;
>+	struct unlink_args args = {
>+		.errp	= &err,
>+		.dir	= dir,
>+		.dentry	= dentry,
>+		.vargs	= vargs
>+	};
>+
>+	if (!vfsub_ftest(vargs->flags, DLGT)
>+	    && !vfsub_ftest(vargs->flags, FORCE_UNLINK))
>+		call_unlink(&args);
>+	else {
>+		int wkq_err;
>+		wkq_err = au_wkq_wait(call_unlink, &args,
>+				      vfsub_ftest(vargs->flags, DLGT));
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	}
>+
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct statfs_args {
>+	int *errp;
>+	void *arg;
>+	struct kstatfs *buf;
>+};
>+
>+static void call_statfs(void *args)
>+{
>+	struct statfs_args *a = args;
>+	*a->errp = vfs_statfs(a->arg, a->buf);
>+}
>+
>+#ifdef CONFIG_AUFS_DLGT
>+static void vfsub_statfs_dlgt(struct statfs_args *args, int dlgt)
>+{
>+	if (!dlgt)
>+		call_statfs(args);
>+	else {
>+		int wkq_err;
>+		wkq_err = au_wkq_wait(call_statfs, args, /*dlgt*/1);
>+		if (unlikely(wkq_err))
>+			*args->errp = wkq_err;
>+	}
>+}
>+#else
>+static void vfsub_statfs_dlgt(struct statfs_args *args, int dlgt)
>+{
>+	call_statfs(args);
>+}
>+#endif
>+
>+int vfsub_statfs(void *arg, struct kstatfs *buf, int dlgt)
>+{
>+	int err;
>+	struct statfs_args args = {
>+		.errp	= &err,
>+		.arg	= arg,
>+		.buf	= buf
>+	};
>+
>+	vfsub_statfs_dlgt(&args, dlgt);
>+
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/vfsub.h linux-2.6.25.4-unionfs/fs/aufs/vfsub.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/vfsub.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/vfsub.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,493 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * sub-routines for VFS
>+ *
>+ * $Id: vfsub.h,v 1.2 2008/04/21 01:49:22 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_VFSUB_H__
>+#define __AUFS_VFSUB_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/namei.h>
>+#include <linux/splice.h>
>+#include <linux/inotify.h>
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* vfsub flags */
>+#define Vfsub_DLGT		1		/* operation with delegation */
>+#define Vfsub_FORCE_UNLINK	(1 << 1)	/* force unlinking */
>+#define vfsub_ftest(flags, name)	((flags) & Vfsub_##name)
>+#define vfsub_fset(flags, name)		{ (flags) |= Vfsub_##name; }
>+#define vfsub_fclr(flags, name)		{ (flags) &= ~Vfsub_##name; }
>+#ifndef CONFIG_AUFS_DLGT
>+#undef Vfsub_DLGT
>+#define Vfsub_DLGT	0
>+#endif
>+
>+struct au_hin_ignore;
>+struct vfsub_args {
>+#ifdef CONFIG_AUFS_HINOTIFY
>+	/* inotify events to be ignored */
>+	int			nignore;
>+	struct au_hin_ignore	*ignore;
>+#endif
>+
>+	unsigned int		flags;
>+};
>+
>+struct au_hinode;
>+#ifdef CONFIG_AUFS_HINOTIFY
>+static inline
>+void do_vfsub_args_reinit(struct vfsub_args *vargs, struct au_hin_ignore *ign)
>+{
>+	vargs->nignore = 0;
>+	vargs->ignore = ign;
>+}
>+
>+static inline void vfsub_args_reinit(struct vfsub_args *vargs)
>+{
>+	vargs->nignore = 0;
>+}
>+
>+__u32 vfsub_events_notify_change(struct iattr *ia);
>+void vfsub_ign_hinode(struct vfsub_args *vargs, __u32 events,
>+		      struct au_hinode *hinode);
>+void vfsub_ign_inode(struct vfsub_args *vargs, __u32 events,
>+		     struct inode *inode, struct inode *h_inode);
>+
>+void vfsub_ignore(struct vfsub_args *vargs);
>+void vfsub_unignore(struct vfsub_args *vargs);
>+#else
>+static inline
>+void do_vfsub_args_reinit(struct vfsub_args *vargs, struct au_hin_ignore *ign)
>+{
>+	/* empty */
>+}
>+
>+static inline void vfsub_args_reinit(struct vfsub_args *vargs)
>+{
>+	/* empty */
>+}
>+
>+static inline __u32 vfsub_events_notify_change(struct iattr *ia)
>+{
>+	return 0;
>+}
>+
>+static inline void vfsub_ign_hinode(struct vfsub_args *vargs, __u32 events,
>+				    struct au_hinode *hinode)
>+{
>+	/* empty */
>+}
>+
>+static inline void vfsub_ign_inode(struct vfsub_args *vargs, __u32 events,
>+				   struct inode *inode, struct inode *h_inode)
>+{
>+	/* empty */
>+}
>+
>+static inline void vfsub_ignore(struct vfsub_args *vargs)
>+{
>+	/* empty */
>+}
>+
>+static inline void vfsub_unignore(struct vfsub_args *vargs)
>+{
>+	/* empty */
>+}
>+#endif /* CONFIG_AUFS_HINOTIFY */
>+
>+void vfsub_args_init(struct vfsub_args *vargs, struct au_hin_ignore *ign,
>+		     int dlgt, int force_unlink);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* inotify_inode_watched() is not exported */
>+static inline int au_test_inotify(struct inode *inode)
>+{
>+#ifdef CONFIG_INOTIFY
>+	return !list_empty(&inode->inotify_watches);
>+#endif
>+	return 0;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* lock subclass for hidden inode */
>+/* default MAX_LOCKDEP_SUBCLASSES(8) is not enough */
>+// todo: reduce it
>+enum {
>+	AuLsc_I_Begin = I_MUTEX_QUOTA, /* 4 */
>+	AuLsc_I_PARENT,		/* hidden inode, parent first */
>+	AuLsc_I_CHILD,
>+	AuLsc_I_PARENT2,	/* copyup dirs */
>+	AuLsc_I_CHILD2,
>+	AuLsc_I_End
>+};
>+
>+#define IMustLock(i)	MtxMustLock(&(i)->i_mutex)
>+
>+static inline
>+struct dentry *vfsub_lock_rename(struct dentry *d1, struct dentry *d2)
>+{
>+	struct dentry *d;
>+
>+	lockdep_off();
>+	d = lock_rename(d1, d2);
>+	lockdep_on();
>+	return d;
>+}
>+
>+static inline void vfsub_unlock_rename(struct dentry *d1, struct dentry *d2)
>+{
>+	lockdep_off();
>+	unlock_rename(d1, d2);
>+	lockdep_on();
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#ifdef CONFIG_AUFS_WORKAROUND_FUSE
>+/* br_fuse.c */
>+int au_update_fuse_h_inode(struct vfsmount *h_mnt, struct dentry *h_dentry);
>+#else
>+static inline
>+int au_update_fuse_h_inode(struct vfsmount *h_mnt, struct dentry *h_dentry)
>+{
>+	return 0;
>+}
>+#endif
>+
>+#ifdef CONFIG_AUFS_BR_XFS
>+/* br_xfs.c */
>+dev_t au_h_rdev(struct inode *h_inode, struct vfsmount *h_mnt,
>+		struct dentry *h_dentry);
>+#else
>+static inline
>+dev_t au_h_rdev(struct inode *h_inode, struct vfsmount *h_mnt,
>+		struct dentry *h_dentry)
>+{
>+	return h_inode->i_rdev;
>+}
>+#endif
>+
>+/* simple abstractions, for future use */
>+static inline
>+int do_vfsub_permission(struct inode *inode, int mask, struct nameidata *nd)
>+{
>+	LKTRTrace("i%lu, mask 0x%x, nd %d\n", inode->i_ino, mask, !!nd);
>+	IMustLock(inode);
>+	return permission(inode, mask, nd);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct file *vfsub_filp_open(const char *path, int oflags, int mode);
>+int vfsub_path_lookup(const char *name, unsigned int flags,
>+		      struct nameidata *nd);
>+struct dentry *vfsub_lookup_one_len(const char *name, struct dentry *parent,
>+				    int len);
>+
>+#ifdef CONFIG_AUFS_LHASH_PATCH
>+struct dentry *vfsub__lookup_hash(struct qstr *name, struct dentry *parent,
>+				  struct nameidata *nd);
>+#endif
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int do_vfsub_create(struct inode *dir, struct dentry *dentry, int mode,
>+		    struct nameidata *nd);
>+int do_vfsub_symlink(struct inode *dir, struct dentry *dentry,
>+		     const char *symname, int mode);
>+int do_vfsub_mknod(struct inode *dir, struct dentry *dentry, int mode,
>+		   dev_t dev);
>+int do_vfsub_link(struct dentry *src_dentry, struct inode *dir,
>+		  struct dentry *dentry);
>+int do_vfsub_rename(struct inode *src_dir, struct dentry *src_dentry,
>+		    struct inode *dir, struct dentry *dentry);
>+int do_vfsub_mkdir(struct inode *dir, struct dentry *dentry, int mode);
>+int do_vfsub_rmdir(struct inode *dir, struct dentry *dentry);
>+int do_vfsub_unlink(struct inode *dir, struct dentry *dentry);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+ssize_t do_vfsub_read_u(struct file *file, char __user *ubuf, size_t count,
>+			loff_t *ppos);
>+// kernel_read() ??
>+ssize_t do_vfsub_read_k(struct file *file, void *kbuf, size_t count,
>+			loff_t *ppos);
>+ssize_t do_vfsub_write_u(struct file *file, const char __user *ubuf,
>+			 size_t count, loff_t *ppos);
>+ssize_t do_vfsub_write_k(struct file *file, void *kbuf, size_t count,
>+			 loff_t *ppos);
>+int do_vfsub_readdir(struct file *file, filldir_t filldir, void *arg);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#ifdef CONFIG_AUFS_SPLICE_PATCH
>+long do_vfsub_splice_to(struct file *in, loff_t *ppos,
>+			struct pipe_inode_info *pipe, size_t len,
>+			unsigned int flags);
>+long do_vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
>+			  loff_t *ppos, size_t len, unsigned int flags);
>+#else
>+static inline
>+long do_vfsub_splice_to(struct file *in, loff_t *ppos,
>+			struct pipe_inode_info *pipe, size_t len,
>+			unsigned int flags)
>+{
>+	return -ENOSYS;
>+}
>+
>+static inline
>+long do_vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
>+			  loff_t *ppos, size_t len, unsigned int flags)
>+{
>+	return -ENOSYS;
>+}
>+#endif /* CONFIG_AUFS_SPLICE_PATCH */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline loff_t vfsub_llseek(struct file *file, loff_t offset, int origin)
>+{
>+	loff_t err;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(file->f_dentry));
>+
>+	lockdep_off();
>+	err = vfs_llseek(file, offset, origin);
>+	lockdep_on();
>+	return err;
>+}
>+
>+static inline int do_vfsub_getattr(struct vfsmount *mnt, struct dentry *dentry,
>+				   struct kstat *st)
>+{
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+	return vfs_getattr(mnt, dentry, st);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#if defined(CONFIG_AUFS_HINOTIFY) || defined(CONFIG_AUFS_DLGT)
>+/* hin_or_dlgt.c */
>+int vfsub_permission(struct inode *inode, int mask, struct nameidata *nd,
>+		     int dlgt);
>+
>+int vfsub_create(struct inode *dir, struct dentry *dentry, int mode,
>+		 struct nameidata *nd, int dlgt);
>+int vfsub_symlink(struct inode *dir, struct dentry *dentry, const char *symname,
>+		  int mode, int dlgt);
>+int vfsub_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev,
>+		int dlgt);
>+int vfsub_link(struct dentry *src_dentry, struct inode *dir,
>+	       struct dentry *dentry, int dlgt);
>+int vfsub_rename(struct inode *src_dir, struct dentry *src_dentry,
>+		 struct inode *dir, struct dentry *dentry,
>+		 struct vfsub_args *vargs);
>+int vfsub_mkdir(struct inode *dir, struct dentry *dentry, int mode, int dlgt);
>+int vfsub_rmdir(struct inode *dir, struct dentry *dentry,
>+		struct vfsub_args *vargs);
>+
>+ssize_t vfsub_read_u(struct file *file, char __user *ubuf, size_t count,
>+		     loff_t *ppos, int dlgt);
>+ssize_t vfsub_read_k(struct file *file, void *kbuf, size_t count, loff_t *ppos,
>+		     int dlgt);
>+ssize_t vfsub_write_u(struct file *file, const char __user *ubuf, size_t count,
>+		      loff_t *ppos, struct vfsub_args *vargs);
>+ssize_t vfsub_write_k(struct file *file, void *kbuf, size_t count, loff_t *ppos,
>+		      struct vfsub_args *vargs);
>+int vfsub_readdir(struct file *file, filldir_t filldir, void *arg, int dlgt);
>+long vfsub_splice_to(struct file *in, loff_t *ppos,
>+		     struct pipe_inode_info *pipe, size_t len,
>+		     unsigned int flags, int dlgt);
>+long vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
>+		       loff_t *ppos, size_t len, unsigned int flags,
>+		       struct vfsub_args *vargs);
>+
>+int vfsub_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *st,
>+		  int dlgt);
>+#else
>+
>+static inline
>+int vfsub_permission(struct inode *inode, int mask, struct nameidata *nd,
>+		     int dlgt)
>+{
>+	return do_vfsub_permission(inode, mask, nd);
>+}
>+
>+static inline
>+int vfsub_create(struct inode *dir, struct dentry *dentry, int mode,
>+		 struct nameidata *nd, int dlgt)
>+{
>+	return do_vfsub_create(dir, dentry, mode, nd);
>+}
>+
>+static inline
>+int vfsub_symlink(struct inode *dir, struct dentry *dentry, const char *symname,
>+		  int mode, int dlgt)
>+{
>+	return do_vfsub_symlink(dir, dentry, symname, mode);
>+}
>+
>+static inline
>+int vfsub_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev,
>+		int dlgt)
>+{
>+	return do_vfsub_mknod(dir, dentry, mode, dev);
>+}
>+
>+static inline
>+int vfsub_link(struct dentry *src_dentry, struct inode *dir,
>+	       struct dentry *dentry, int dlgt)
>+{
>+	return do_vfsub_link(src_dentry, dir, dentry);
>+}
>+
>+static inline
>+int vfsub_rename(struct inode *src_dir, struct dentry *src_dentry,
>+		 struct inode *dir, struct dentry *dentry,
>+		 struct vfsub_args *vargs)
>+{
>+	int err;
>+
>+	vfsub_ignore(vargs);
>+	err = do_vfsub_rename(src_dir, src_dentry, dir, dentry);
>+	if (unlikely(err))
>+		vfsub_unignore(vargs);
>+	return err;
>+}
>+
>+static inline
>+int vfsub_mkdir(struct inode *dir, struct dentry *dentry, int mode, int dlgt)
>+{
>+	return do_vfsub_mkdir(dir, dentry, mode);
>+}
>+
>+static inline
>+int vfsub_rmdir(struct inode *dir, struct dentry *dentry,
>+		struct vfsub_args *vargs)
>+{
>+	int err;
>+
>+	vfsub_ignore(vargs);
>+	err = do_vfsub_rmdir(dir, dentry);
>+	if (unlikely(err))
>+		vfsub_unignore(vargs);
>+	return err;
>+}
>+
>+static inline
>+ssize_t vfsub_read_u(struct file *file, char __user *ubuf, size_t count,
>+		     loff_t *ppos, int dlgt)
>+{
>+	return do_vfsub_read_u(file, ubuf, count, ppos);
>+}
>+
>+static inline
>+ssize_t vfsub_read_k(struct file *file, void *kbuf, size_t count, loff_t *ppos,
>+		     int dlgt)
>+{
>+	return do_vfsub_read_k(file, kbuf, count, ppos);
>+}
>+
>+static inline
>+ssize_t vfsub_write_u(struct file *file, const char __user *ubuf, size_t count,
>+		      loff_t *ppos, struct vfsub_args *vargs)
>+{
>+	int err;
>+
>+	vfsub_ignore(vargs);
>+	err = do_vfsub_write_u(file, ubuf, count, ppos);
>+	if (unlikely(err < 0))
>+		vfsub_unignore(vargs);
>+	return err;
>+}
>+
>+static inline
>+ssize_t vfsub_write_k(struct file *file, void *kbuf, size_t count, loff_t *ppos,
>+		      struct vfsub_args *vargs)
>+{
>+	int err;
>+
>+	vfsub_ignore(vargs);
>+	err = do_vfsub_write_k(file, kbuf, count, ppos);
>+	if (unlikely(err < 0))
>+		vfsub_unignore(vargs);
>+	return err;
>+}
>+
>+static inline
>+int vfsub_readdir(struct file *file, filldir_t filldir, void *arg, int dlgt)
>+{
>+	return do_vfsub_readdir(file, filldir, arg);
>+}
>+
>+static inline
>+long vfsub_splice_to(struct file *in, loff_t *ppos,
>+		     struct pipe_inode_info *pipe, size_t len,
>+		     unsigned int flags, int dlgt)
>+{
>+	return do_vfsub_splice_to(in, ppos, pipe, len, flags);
>+}
>+
>+static inline
>+long vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
>+		       loff_t *ppos, size_t len, unsigned int flags,
>+		       struct vfsub_args *vargs)
>+{
>+	long err;
>+
>+	vfsub_ignore(vargs);
>+	err = do_vfsub_splice_from(pipe, out, ppos, len, flags);
>+	if (unlikely(err < 0))
>+		vfsub_unignore(vargs);
>+	return err;
>+}
>+
>+static inline
>+int vfsub_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *st,
>+		  int dlgt)
>+{
>+	return do_vfsub_getattr(mnt, dentry, st);
>+}
>+#endif /* CONFIG_AUFS_DLGT || CONFIG_AUFS_HINOTIFY */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int vfsub_sio_mkdir(struct inode *dir, struct dentry *dentry, int mode,
>+		    int dlgt);
>+int vfsub_sio_rmdir(struct inode *dir, struct dentry *dentry, int dlgt);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int vfsub_notify_change(struct dentry *dentry, struct iattr *ia,
>+			struct vfsub_args *vargs);
>+int vfsub_unlink(struct inode *dir, struct dentry *dentry,
>+		 struct vfsub_args *vargs);
>+int vfsub_statfs(void *arg, struct kstatfs *buf, int dlgt);
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_VFSUB_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/wbr_policy.c linux-2.6.25.4-unionfs/fs/aufs/wbr_policy.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/wbr_policy.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/wbr_policy.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,693 @@
>+/*
>+ * Copyright (C) 2007-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * policies for selecting one among multiple writable branches
>+ *
>+ * $Id: wbr_policy.c,v 1.3 2008/04/28 03:04:12 sfjro Exp $
>+ */
>+
>+#include <linux/statfs.h>
>+#include "aufs.h"
>+
>+static int au_cpdown_attr(struct dentry *h_dst, struct dentry *h_src, int dlgt)
>+{
>+	int err, sbits;
>+	struct iattr ia;
>+	struct inode *h_idst, *h_isrc;
>+	struct vfsub_args vargs;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(h_dst));
>+	h_idst = h_dst->d_inode;
>+	//IMustLock(h_idst);
>+	h_isrc = h_src->d_inode;
>+	//IMustLock(h_isrc);
>+
>+	ia.ia_valid = ATTR_FORCE | ATTR_MODE | ATTR_UID | ATTR_GID;
>+	ia.ia_mode = h_isrc->i_mode;
>+	ia.ia_uid = h_isrc->i_uid;
>+	ia.ia_gid = h_isrc->i_gid;
>+	sbits = !!(ia.ia_mode & (S_ISUID | S_ISGID));
>+
>+	vfsub_args_init(&vargs, NULL, dlgt, /*force_unlink*/0);
>+	err = vfsub_notify_change(h_dst, &ia, &vargs);
>+
>+	/* is this nfs only? */
>+	if (!err && sbits && au_test_nfs(h_dst->d_sb)) {
>+		ia.ia_valid = ATTR_FORCE | ATTR_MODE;
>+		ia.ia_mode = h_isrc->i_mode;
>+		err = vfsub_notify_change(h_dst, &ia, &vargs);
>+	}
>+
>+	if (!err)
>+		h_idst->i_flags = h_isrc->i_flags; //??
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+struct au_cpdown_dir_args {
>+	struct dentry *parent;
>+	unsigned int parent_opq; // bit-flags
>+};
>+
>+static int au_cpdown_dir(struct dentry *dentry, aufs_bindex_t bdst,
>+			 struct dentry *h_parent, void *arg)
>+{
>+	int err, parent_opq, whed, dlgt, do_opq, made_dir, diropq, rerr;
>+	struct au_cpdown_dir_args *args = arg;
>+	aufs_bindex_t bend, bopq, bstart;
>+	struct dentry *h_dentry, *opq_dentry, *wh_dentry;
>+	struct inode *h_dir, *h_inode, *inode;
>+
>+	LKTRTrace("%.*s, b%d\n", AuDLNPair(dentry), bdst);
>+	bstart = au_dbstart(dentry);
>+	AuDebugOn(bstart <= bdst
>+		  && bdst <= au_dbend(dentry)
>+		  && au_h_dptr(dentry, bdst));
>+	AuDebugOn(!h_parent);
>+	h_dir = h_parent->d_inode;
>+	AuDebugOn(!h_dir);
>+	IMustLock(h_dir);
>+
>+	err = au_lkup_neg(dentry, bdst);
>+	if (unlikely(err < 0))
>+		goto out;
>+	h_dentry = au_h_dptr(dentry, bdst);
>+	dlgt = !!au_opt_test_dlgt(au_mntflags(dentry->d_sb));
>+	err = vfsub_sio_mkdir(h_dir, h_dentry, S_IRWXU | S_IRUGO | S_IXUGO,
>+			      dlgt);
>+	if (unlikely(err))
>+		goto out_put;
>+
>+	made_dir = 1;
>+	bend = au_dbend(dentry);
>+	bopq = au_dbdiropq(dentry);
>+	whed = (au_dbwh(dentry) == bdst);
>+	if (!args->parent_opq)
>+		args->parent_opq |= (bopq <= bdst);
>+	parent_opq = (args->parent_opq && args->parent == dentry);
>+	do_opq = 0;
>+	diropq = 0;
>+	h_inode = h_dentry->d_inode;
>+	mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
>+	if (whed || (parent_opq && do_opq)) {
>+		opq_dentry = au_diropq_create(dentry, bdst, dlgt);
>+		err = PTR_ERR(opq_dentry);
>+		if (IS_ERR(opq_dentry)) {
>+			mutex_unlock(&h_inode->i_mutex);
>+			goto out_dir;
>+		}
>+		dput(opq_dentry);
>+		diropq = 1;
>+	}
>+
>+	err = au_cpdown_attr(h_dentry, au_h_dptr(dentry, bstart), dlgt);
>+	mutex_unlock(&h_inode->i_mutex);
>+	if (unlikely(err))
>+		goto out_opq;
>+
>+	wh_dentry = NULL;
>+	if (whed) {
>+		wh_dentry = au_wh_lkup(h_parent, &dentry->d_name, /*ndx*/NULL);
>+		err = PTR_ERR(wh_dentry);
>+		if (IS_ERR(wh_dentry))
>+			goto out_opq;
>+		err = 0;
>+		if (wh_dentry->d_inode)
>+			err = au_wh_unlink_dentry(h_dir, wh_dentry, dentry,
>+						  NULL, dlgt);
>+		dput(wh_dentry);
>+		if (unlikely(err))
>+			goto out_opq;
>+	}
>+
>+	inode = dentry->d_inode;
>+	if (au_ibend(inode) < bdst)
>+		au_set_ibend(inode, bdst);
>+	au_set_h_iptr(inode, bdst, igrab(h_inode), au_hi_flags(inode, 1));
>+	goto out; /* success */
>+
>+	/* revert */
>+ out_opq:
>+	if (diropq) {
>+		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
>+		rerr = au_diropq_remove(dentry, bdst, dlgt);
>+		mutex_unlock(&h_inode->i_mutex);
>+		if (unlikely(rerr)) {
>+			AuIOErr("failed removing diropq for %.*s b%d (%d)\n",
>+				AuDLNPair(dentry), bdst, rerr);
>+			err = -EIO;
>+			goto out;
>+		}
>+	}
>+ out_dir:
>+	if (made_dir) {
>+		rerr = vfsub_sio_rmdir(h_dir, h_dentry, dlgt);
>+		if (unlikely(rerr)) {
>+			AuIOErr("failed removing %.*s b%d (%d)\n",
>+				AuDLNPair(dentry), bdst, rerr);
>+			err = -EIO;
>+		}
>+	}
>+ out_put:
>+	au_set_h_dptr(dentry, bdst, NULL);
>+	if (au_dbend(dentry) == bdst)
>+		au_update_dbend(dentry);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_cpdown_dirs(struct dentry *dentry, aufs_bindex_t bdst,
>+		   struct dentry *locked)
>+{
>+	int err;
>+	struct au_cpdown_dir_args args = {
>+		.parent		= dget_parent(dentry),
>+		.parent_opq	= 0
>+	};
>+
>+	LKTRTrace("%.*s, b%d\n", AuDLNPair(dentry), bdst);
>+
>+	err = au_cp_dirs(dentry, bdst, locked, au_cpdown_dir, &args);
>+	dput(args.parent);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* policies for create */
>+
>+static int au_wbr_bu(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	for (; bindex >= 0; bindex--)
>+		if (!au_br_rdonly(au_sbr(sb, bindex)))
>+			return bindex;
>+	return -EROFS;
>+}
>+
>+/* top down parent */
>+static int au_wbr_create_tdp(struct dentry *dentry, int isdir)
>+{
>+	int err, dirperm1;
>+	struct super_block *sb;
>+	aufs_bindex_t bstart, bindex;
>+	struct dentry *parent, *h_parent;
>+	struct inode *h_dir;
>+
>+	LKTRTrace("%.*s, dir %d\n", AuDLNPair(dentry), isdir);
>+
>+	sb = dentry->d_sb;
>+	dirperm1 = !!au_opt_test_dirperm1(au_mntflags(sb));
>+	bstart = au_dbstart(dentry);
>+	err = bstart;
>+	if (!au_br_rdonly(au_sbr(sb, bstart)))
>+		goto out;
>+
>+	err = -EROFS;
>+	parent = dget_parent(dentry);
>+	for (bindex = au_dbstart(parent); bindex < bstart; bindex++) {
>+		h_parent = au_h_dptr(parent, bindex);
>+		if (!h_parent)
>+			continue;
>+		h_dir = h_parent->d_inode;
>+		if (!h_dir)
>+			continue;
>+
>+		if (!au_br_rdonly(au_sbr(sb, bindex))
>+		    && (!dirperm1
>+			|| au_test_h_perm(h_dir, MAY_WRITE | MAY_EXEC,
>+					  /*dlgt*/0))) {
>+				err = bindex;
>+				break;
>+		}
>+	}
>+	dput(parent);
>+
>+	/* bottom up here */
>+	if (unlikely(err < 0))
>+		err = au_wbr_bu(sb, bstart - 1);
>+
>+ out:
>+	LKTRTrace("b%d\n", err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* an exception for the policy other than tdp */
>+static int au_wbr_create_exp(struct dentry *dentry)
>+{
>+	int err;
>+	struct dentry *parent;
>+	aufs_bindex_t bwh, bdiropq;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	err = -1;
>+	bwh = au_dbwh(dentry);
>+	parent = dget_parent(dentry);
>+	bdiropq = au_dbdiropq(parent);
>+	if (bwh >= 0) {
>+		if (bdiropq >= 0)
>+			err = min(bdiropq, bwh);
>+		else
>+			err = bwh;
>+		LKTRTrace("%d\n", err);
>+	} else if (bdiropq >= 0) {
>+		err = bdiropq;
>+		LKTRTrace("%d\n", err);
>+	}
>+	dput(parent);
>+
>+	if (err >= 0 && au_br_rdonly(au_sbr(dentry->d_sb, err)))
>+		err = -1;
>+
>+	LKTRTrace("%d\n", err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* round robin */
>+static int au_wbr_create_init_rr(struct super_block *sb)
>+{
>+	int err;
>+
>+	err = au_wbr_bu(sb, au_sbend(sb));
>+	atomic_set(&au_sbi(sb)->si_wbr_rr_next, -err); /* less important */
>+
>+	LKTRTrace("b%d\n", err);
>+	return err;
>+}
>+
>+static int au_wbr_create_rr(struct dentry *dentry, int isdir)
>+{
>+	int err, nbr;
>+	struct super_block *sb;
>+	atomic_t *next;
>+	unsigned int u;
>+	aufs_bindex_t bindex, bend;
>+
>+	//au_debug_on();
>+	LKTRTrace("%.*s, dir %d\n", AuDLNPair(dentry), isdir);
>+
>+	sb = dentry->d_sb;
>+	next = NULL;
>+	err = au_wbr_create_exp(dentry);
>+	if (err >= 0)
>+		goto out;
>+
>+	next = &au_sbi(sb)->si_wbr_rr_next;
>+	bend = au_sbend(sb);
>+	nbr = bend + 1;
>+	for (bindex = 0; bindex <= bend; bindex++) {
>+		if (!isdir) {
>+			err = atomic_dec_return(next) + 1;
>+			/* modulo for 0 is meaningless */
>+			if (unlikely(!err))
>+				err = atomic_dec_return(next) + 1;
>+		} else
>+			err = atomic_read(next);
>+		LKTRTrace("%d\n", err);
>+		u = err;
>+		err = u % nbr;
>+		LKTRTrace("%d\n", err);
>+		if (!au_br_rdonly(au_sbr(sb, err)))
>+			break;
>+		err = -EROFS;
>+	}
>+
>+ out:
>+	LKTRTrace("%d\n", err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* most free space */
>+static void *au_wbr_statfs_arg(struct au_branch *br, struct super_block *sb,
>+			       aufs_bindex_t bindex)
>+{
>+	struct super_block *h_sb;
>+
>+	h_sb = br->br_mnt->mnt_sb;
>+
>+	if (!au_test_nfs(h_sb))
>+		return h_sb->s_root;
>+
>+	/* sigh,,, why nfs s_root has wrong inode? */
>+	return au_di(sb->s_root)->di_hdentry[0 + bindex].hd_dentry;
>+}
>+
>+static void au_mfs(struct dentry *dentry)
>+{
>+	struct super_block *sb;
>+	aufs_bindex_t bindex, bend;
>+	int dlgt, err;
>+	struct kstatfs st;
>+	u64 b, bavail;
>+	void *arg;
>+	struct au_branch *br;
>+	struct au_wbr_mfs *mfs;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	bavail = 0;
>+	sb = dentry->d_sb;
>+	mfs = &au_sbi(sb)->si_wbr_mfs;
>+	mfs->mfs_bindex = -EROFS;
>+	mfs->mfsrr_bytes = 0;
>+	dlgt = !!au_opt_test_dlgt(au_mntflags(sb));
>+	bend = au_sbend(sb);
>+	for (bindex = 0; bindex <= bend; bindex++) {
>+		br = au_sbr(sb, bindex);
>+		if (au_br_rdonly(br))
>+			continue;
>+		arg = au_wbr_statfs_arg(br, sb, bindex);
>+		if (!arg)
>+			continue;
>+
>+		err = vfsub_statfs(arg, &st, dlgt);
>+		LKTRTrace("b%d, %d, %Lu\n",
>+			  bindex, err, (unsigned long long)st.f_bavail);
>+		if (unlikely(err)) {
>+			AuWarn1("failed statfs, b%d, %d\n", bindex, err);
>+			continue;
>+		}
>+
>+		/* when the available size is equal, select lower one */
>+		b = st.f_bavail * st.f_bsize;
>+		br->br_bytes = b;
>+		if (b >= bavail) {
>+			bavail = b;
>+			mfs->mfs_bindex = bindex;
>+			mfs->mfs_jiffy = jiffies;
>+		}
>+	}
>+
>+	mfs->mfsrr_bytes = bavail;
>+	LKTRTrace("b%d\n", mfs->mfs_bindex);
>+}
>+
>+static int au_wbr_create_mfs(struct dentry *dentry, int isdir)
>+{
>+	int err;
>+	struct super_block *sb;
>+	struct au_wbr_mfs *mfs;
>+
>+	//au_debug_on();
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	sb = dentry->d_sb;
>+	err = au_wbr_create_exp(dentry);
>+	if (err >= 0)
>+		goto out;
>+
>+	mfs = &au_sbi(sb)->si_wbr_mfs;
>+	mutex_lock(&mfs->mfs_lock);
>+	if (unlikely(time_after(jiffies, mfs->mfs_jiffy + mfs->mfs_expire)
>+		     || mfs->mfs_bindex < 0
>+		     || au_br_rdonly(au_sbr(sb, mfs->mfs_bindex))))
>+		au_mfs(dentry);
>+	mutex_unlock(&mfs->mfs_lock);
>+	err = mfs->mfs_bindex;
>+
>+ out:
>+	LKTRTrace("b%d\n", err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+static int au_wbr_create_init_mfs(struct super_block *sb)
>+{
>+	struct au_wbr_mfs *mfs;
>+
>+	mfs = &au_sbi(sb)->si_wbr_mfs;
>+	LKTRTrace("expire %lu\n", mfs->mfs_expire);
>+
>+	mutex_init(&mfs->mfs_lock);
>+	mfs->mfs_jiffy = 0;
>+	mfs->mfs_bindex = -EROFS;
>+
>+	return 0;
>+}
>+
>+static int au_wbr_create_fin_mfs(struct super_block *sb)
>+{
>+	AuTraceEnter();
>+	mutex_destroy(&au_sbi(sb)->si_wbr_mfs.mfs_lock);
>+	return 0;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* most free space and then round robin */
>+static int au_wbr_create_mfsrr(struct dentry *dentry, int isdir)
>+{
>+	int err;
>+	struct au_wbr_mfs *mfs;
>+
>+	//au_debug_on();
>+	LKTRTrace("%.*s, %d\n", AuDLNPair(dentry), isdir);
>+
>+	err = au_wbr_create_mfs(dentry, isdir);
>+	if (err >= 0) {
>+		mfs = &au_sbi(dentry->d_sb)->si_wbr_mfs;
>+		LKTRTrace("%Lu bytes, %Lu wmark\n",
>+			  mfs->mfsrr_bytes, mfs->mfsrr_watermark);
>+		if (unlikely(mfs->mfsrr_bytes < mfs->mfsrr_watermark))
>+			err = au_wbr_create_rr(dentry, isdir);
>+	}
>+
>+	LKTRTrace("b%d\n", err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+static int au_wbr_create_init_mfsrr(struct super_block *sb)
>+{
>+	int err;
>+	//au_debug_on();
>+	au_wbr_create_init_mfs(sb); /* ignore */
>+	err = au_wbr_create_init_rr(sb);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* top down parent and most free space */
>+static int au_wbr_create_pmfs(struct dentry *dentry, int isdir)
>+{
>+	int err, e2, dirperm1;
>+	struct super_block *sb;
>+	struct dentry *parent, *h_parent;
>+	aufs_bindex_t bindex, bstart, bend;
>+	struct au_branch *br;
>+	u64 b;
>+	struct inode *h_dir;
>+
>+	//au_debug_on();
>+	LKTRTrace("%.*s, %d\n", AuDLNPair(dentry), isdir);
>+
>+	err = au_wbr_create_tdp(dentry, isdir);
>+	if (unlikely(err < 0))
>+		goto out;
>+	parent = dget_parent(dentry);
>+	bstart = au_dbstart(parent);
>+	bend = au_dbtaildir(parent);
>+	if (bstart == bend)
>+		goto out_parent; /* success */
>+
>+	e2 = au_wbr_create_mfs(dentry, isdir);
>+	if (e2 < 0)
>+		goto out_parent; /* success */
>+
>+	/* when the available size is equal, select upper one */
>+	sb = dentry->d_sb;
>+	br = au_sbr(sb, err);
>+	dirperm1 = !!au_opt_test_dirperm1(au_mntflags(sb));
>+	b = br->br_bytes;
>+	LKTRTrace("b%d, %Lu\n", err, b);
>+
>+	if (unlikely(dirperm1)) {
>+		for (bindex = bstart; bindex <= bend; bindex++) {
>+			h_parent = au_h_dptr(parent, bindex);
>+			if (!h_parent)
>+				continue;
>+			h_dir = h_parent->d_inode;
>+			if (!h_dir)
>+				continue;
>+
>+			br = au_sbr(sb, bindex);
>+			if (!au_br_rdonly(br)
>+			    && au_test_h_perm(h_dir, MAY_WRITE | MAY_EXEC,
>+					      /*dlgt*/0)
>+			    && br->br_bytes > b) {
>+				b = br->br_bytes;
>+				err = bindex;
>+				LKTRTrace("b%d, %Lu\n", err, b);
>+			}
>+		}
>+		if (err >= 0)
>+			goto out_parent;
>+	}
>+	for (bindex = bstart; bindex <= bend; bindex++) {
>+		h_parent = au_h_dptr(parent, bindex);
>+		if (!h_parent || !h_parent->d_inode)
>+			continue;
>+
>+		br = au_sbr(sb, bindex);
>+		if (!au_br_rdonly(br) && br->br_bytes > b) {
>+			b = br->br_bytes;
>+			err = bindex;
>+			LKTRTrace("b%d, %Lu\n", err, b);
>+		}
>+	}
>+
>+ out_parent:
>+	dput(parent);
>+ out:
>+	LKTRTrace("b%d\n", err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* policies for copyup */
>+
>+/* top down parent */
>+static int au_wbr_copyup_tdp(struct dentry *dentry)
>+{
>+	return au_wbr_create_tdp(dentry, /*isdir, anything is ok*/0);
>+}
>+
>+/* bottom up parent */
>+static int au_wbr_copyup_bup(struct dentry *dentry)
>+{
>+	int err, dirperm1;
>+	struct dentry *parent, *h_parent;
>+	aufs_bindex_t bindex, bstart;
>+	struct super_block *sb;
>+	struct inode *h_dir;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	err = -EROFS;
>+	sb = dentry->d_sb;
>+	dirperm1 = !!au_opt_test_dirperm1(au_mntflags(sb));
>+	parent = dget_parent(dentry);
>+	bstart = au_dbstart(parent);
>+	for (bindex = au_dbstart(dentry); bindex >= bstart; bindex--) {
>+		h_parent = au_h_dptr(parent, bindex);
>+		if (!h_parent)
>+			continue;
>+		h_dir = h_parent->d_inode;
>+		if (!h_dir)
>+			continue;
>+
>+		if (!au_br_rdonly(au_sbr(sb, bindex))
>+		    && (!dirperm1
>+			|| au_test_h_perm(h_dir, MAY_WRITE | MAY_EXEC,
>+					  /*dlgt*/0))) {
>+			err = bindex;
>+			break;
>+		}
>+	}
>+	dput(parent);
>+
>+	/* bottom up here */
>+	if (unlikely(err < 0))
>+		err = au_wbr_bu(sb, bstart - 1);
>+
>+	LKTRTrace("b%d\n", err);
>+	return err;
>+}
>+
>+/* bottom up */
>+static int au_wbr_copyup_bu(struct dentry *dentry)
>+{
>+	int err;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
>+
>+	err = au_wbr_bu(dentry->d_sb, au_dbstart(dentry));
>+
>+	LKTRTrace("b%d\n", err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct au_wbr_copyup_operations au_wbr_copyup_ops[] = {
>+	[AuWbrCopyup_TDP] = {
>+		.copyup	= au_wbr_copyup_tdp
>+	},
>+	[AuWbrCopyup_BUP] = {
>+		.copyup	= au_wbr_copyup_bup
>+	},
>+	[AuWbrCopyup_BU] = {
>+		.copyup	= au_wbr_copyup_bu
>+	}
>+};
>+
>+struct au_wbr_create_operations au_wbr_create_ops[] = {
>+	[AuWbrCreate_TDP] = {
>+		.create	= au_wbr_create_tdp
>+	},
>+	[AuWbrCreate_RR] = {
>+		.create	= au_wbr_create_rr,
>+		.init	= au_wbr_create_init_rr
>+	},
>+	[AuWbrCreate_MFS] = {
>+		.create	= au_wbr_create_mfs,
>+		.init	= au_wbr_create_init_mfs,
>+		.fin	= au_wbr_create_fin_mfs
>+	},
>+	[AuWbrCreate_MFSV] = {
>+		.create	= au_wbr_create_mfs,
>+		.init	= au_wbr_create_init_mfs,
>+		.fin	= au_wbr_create_fin_mfs
>+	},
>+	[AuWbrCreate_MFSRR] = {
>+		.create	= au_wbr_create_mfsrr,
>+		.init	= au_wbr_create_init_mfsrr,
>+		.fin	= au_wbr_create_fin_mfs
>+	},
>+	[AuWbrCreate_MFSRRV] = {
>+		.create	= au_wbr_create_mfsrr,
>+		.init	= au_wbr_create_init_mfsrr,
>+		.fin	= au_wbr_create_fin_mfs
>+	},
>+	[AuWbrCreate_PMFS] = {
>+		.create	= au_wbr_create_pmfs,
>+		.init	= au_wbr_create_init_mfs,
>+		.fin	= au_wbr_create_fin_mfs
>+	},
>+	[AuWbrCreate_PMFSV] = {
>+		.create	= au_wbr_create_pmfs,
>+		.init	= au_wbr_create_init_mfs,
>+		.fin	= au_wbr_create_fin_mfs
>+	}
>+};
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/whout.c linux-2.6.25.4-unionfs/fs/aufs/whout.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/whout.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/whout.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,1052 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * whiteout for logical deletion and opaque directory
>+ *
>+ * $Id: whout.c,v 1.4 2008/05/12 00:27:58 sfjro Exp $
>+ */
>+
>+#include <linux/fs.h>
>+#include <linux/namei.h>
>+//#include <linux/random.h>
>+//#include <linux/security.h>
>+#include "aufs.h"
>+
>+#define WH_MASK			S_IRUGO
>+
>+/* If a directory contains this file, then it is opaque.  We start with the
>+ * .wh. flag so that it is blocked by lookup.
>+ */
>+static struct qstr diropq_name = {
>+	.name = AUFS_WH_DIROPQ,
>+	.len = sizeof(AUFS_WH_DIROPQ) - 1
>+};
>+
>+/*
>+ * generate whiteout name, which is NOT terminated by NULL.
>+ * @name: original d_name.name
>+ * @len: original d_name.len
>+ * @wh: whiteout qstr
>+ * returns zero when succeeds, otherwise error.
>+ * succeeded value as wh->name should be freed by au_wh_name_free().
>+ */
>+int au_wh_name_alloc(const char *name, int len, struct qstr *wh)
>+{
>+	char *p;
>+
>+	AuDebugOn(!name || !len || !wh);
>+
>+	if (unlikely(len > PATH_MAX - AUFS_WH_PFX_LEN))
>+		return -ENAMETOOLONG;
>+
>+	wh->len = len + AUFS_WH_PFX_LEN;
>+	p = kmalloc(wh->len, GFP_KERNEL);
>+	wh->name = p;
>+	//if (LktrCond) {kfree(p); wh->name = p = NULL;}
>+	if (p) {
>+		memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
>+		memcpy(p + AUFS_WH_PFX_LEN, name, len);
>+		//smp_mb();
>+		return 0;
>+	}
>+	return -ENOMEM;
>+}
>+
>+void au_wh_name_free(struct qstr *wh)
>+{
>+	AuDebugOn(!wh || !wh->name);
>+	kfree(wh->name);
>+#ifdef CONFIG_AUFS_DEBUG
>+	wh->name = NULL;
>+#endif
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * test if the @wh_name exists under @h_parent.
>+ * @try_sio specifies the necessary of super-io.
>+ */
>+int au_wh_test(struct dentry *h_parent, struct qstr *wh_name, int try_sio,
>+	       struct au_ndx *ndx)
>+{
>+	int err;
>+	struct dentry *wh_dentry;
>+	struct inode *h_dir;
>+	unsigned int flags;
>+
>+	LKTRTrace("%.*s/%.*s, ndx{%p, 0x%x}\n", AuDLNPair(h_parent),
>+		  wh_name->len, wh_name->name, ndx->nfsmnt, ndx->flags);
>+	h_dir = h_parent->d_inode;
>+	AuDebugOn(!S_ISDIR(h_dir->i_mode));
>+
>+	flags = 0;
>+	if (ndx && ndx->nd) {
>+		flags = ndx->nd->flags;
>+		ndx->nd->flags &= ~(LOOKUP_OPEN | LOOKUP_CREATE);
>+	}
>+
>+	if (!try_sio)
>+		wh_dentry = au_lkup_one(wh_name->name, h_parent,
>+					wh_name->len, ndx);
>+	else
>+		wh_dentry = au_sio_lkup_one(wh_name->name, h_parent,
>+					    wh_name->len, ndx);
>+	if (flags)
>+		ndx->nd->flags = flags;
>+	//if (LktrCond) {dput(wh_dentry); wh_dentry = ERR_PTR(-1);}
>+	err = PTR_ERR(wh_dentry);
>+	if (IS_ERR(wh_dentry))
>+		goto out;
>+
>+	err = 0;
>+	if (!wh_dentry->d_inode)
>+		goto out_wh; /* success */
>+
>+	err = 1;
>+	if (S_ISREG(wh_dentry->d_inode->i_mode))
>+		goto out_wh; /* success */
>+
>+	err = -EIO;
>+	AuIOErr("%.*s Invalid whiteout entry type 0%o.\n",
>+		AuDLNPair(wh_dentry), wh_dentry->d_inode->i_mode);
>+
>+ out_wh:
>+	dput(wh_dentry);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * test if the @h_dentry sets opaque or not.
>+ */
>+int au_diropq_test(struct dentry *h_dentry, struct au_ndx *ndx)
>+{
>+	int err, try_sio;
>+	struct inode *h_dir;
>+
>+	LKTRTrace("dentry %.*s\n", AuDLNPair(h_dentry));
>+	h_dir = h_dentry->d_inode;
>+	AuDebugOn(!S_ISDIR(h_dir->i_mode));
>+
>+	try_sio = au_test_h_perm_sio(h_dir, MAY_EXEC,
>+				     au_ftest_ndx(ndx->flags, DLGT));
>+	err = au_wh_test(h_dentry, &diropq_name, try_sio, ndx);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/*
>+ * returns a negative dentry whose name is unique and temporary.
>+ */
>+struct dentry *au_whtmp_lkup(struct dentry *h_parent, struct qstr *prefix,
>+			     struct au_ndx *ndx)
>+{
>+#define HEX_LEN 4
>+	struct dentry *dentry;
>+	int len, i;
>+	char defname[AUFS_WH_PFX_LEN * 2 + DNAME_INLINE_LEN_MIN + 1
>+		     + HEX_LEN + 1], *name, *p;
>+	static unsigned char cnt;
>+
>+	LKTRTrace("hp %.*s, prefix %.*s\n",
>+		  AuDLNPair(h_parent), prefix->len, prefix->name);
>+	AuDebugOn(!h_parent->d_inode);
>+
>+	name = defname;
>+	len = sizeof(defname) - DNAME_INLINE_LEN_MIN + prefix->len - 1;
>+	if (unlikely(prefix->len > DNAME_INLINE_LEN_MIN)) {
>+		dentry = ERR_PTR(-ENAMETOOLONG);
>+		if (unlikely(len >= PATH_MAX))
>+			goto out;
>+		dentry = ERR_PTR(-ENOMEM);
>+		name = kmalloc(len + 1, GFP_KERNEL);
>+		//if (LktrCond) {kfree(name); name = NULL;}
>+		if (unlikely(!name))
>+			goto out;
>+	}
>+
>+	/* doubly whiteout-ed */
>+	memcpy(name, AUFS_WH_PFX AUFS_WH_PFX, AUFS_WH_PFX_LEN * 2);
>+	p = name + AUFS_WH_PFX_LEN * 2;
>+	memcpy(p, prefix->name, prefix->len);
>+	p += prefix->len;
>+	*p++ = '.';
>+	AuDebugOn(name + len + 1 - p <= HEX_LEN);
>+
>+	for (i = 0; i < 3; i++) {
>+		sprintf(p, "%.*d", HEX_LEN, cnt++);
>+		dentry = au_sio_lkup_one(name, h_parent, len, ndx);
>+		//if (LktrCond) {dput(dentry); dentry = ERR_PTR(-1);}
>+		if (IS_ERR(dentry) || !dentry->d_inode)
>+			goto out_name;
>+		dput(dentry);
>+	}
>+	/* AuWarn("could not get random name\n"); */
>+	dentry = ERR_PTR(-EEXIST);
>+	AuDbg("%.*s\n", len, name);
>+	BUG();
>+
>+ out_name:
>+	if (unlikely(name != defname))
>+		kfree(name);
>+ out:
>+	AuTraceErrPtr(dentry);
>+	return dentry;
>+#undef HEX_LEN
>+}
>+
>+/*
>+ * rename the @dentry of @bindex to the whiteouted temporary name.
>+ */
>+int au_whtmp_ren(struct inode *dir, struct dentry *dentry, aufs_bindex_t bindex,
>+		 int noself)
>+{
>+	int err, dlgt;
>+	struct inode *h_dir;
>+	struct dentry *h_dentry, *h_parent, *tmp_dentry;
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+	struct au_hin_ignore ign;
>+	struct vfsub_args vargs;
>+	struct au_ndx ndx = {
>+		.flags	= 0,
>+		.nd	= NULL,
>+		//.br	= NULL
>+	};
>+
>+	LKTRTrace("%.*s, b%d\n", AuDLNPair(dentry), bindex);
>+	h_dentry = au_h_dptr(dentry, bindex);
>+	AuDebugOn(!h_dentry || !h_dentry->d_inode);
>+	h_parent = h_dentry->d_parent; /* dir inode is locked */
>+	h_dir = h_parent->d_inode;
>+	IMustLock(h_dir);
>+
>+	sb = dentry->d_sb;
>+	mnt_flags = au_mntflags(sb);
>+	dlgt = !!au_opt_test_dlgt(mnt_flags);
>+	if (unlikely(dlgt))
>+		au_fset_ndx(ndx.flags, DLGT);
>+	ndx.nfsmnt = au_nfsmnt(sb, bindex);
>+	tmp_dentry = au_whtmp_lkup(h_parent, &h_dentry->d_name, &ndx);
>+	//if (LktrCond) {dput(tmp_dentry); tmp_dentry = ERR_PTR(-1);}
>+	err = PTR_ERR(tmp_dentry);
>+	if (!IS_ERR(tmp_dentry)) {
>+		/* under the same dir, no need to lock_rename() */
>+		vfsub_args_init(&vargs, &ign, dlgt, 0);
>+		AuDebugOn(!S_ISDIR(dentry->d_inode->i_mode));
>+		if (unlikely(au_opt_test(mnt_flags, UDBA_INOTIFY) && !noself))
>+			vfsub_ign_hinode(&vargs, IN_MOVE_SELF,
>+					 au_hi(dentry->d_inode, bindex));
>+		err = vfsub_rename(h_dir, h_dentry, h_dir, tmp_dentry, &vargs);
>+		//if (LktrCond) err = -1; //unavailable
>+		AuTraceErr(err);
>+		dput(tmp_dentry);
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static int do_unlink_wh(struct inode *h_dir, struct dentry *wh_dentry,
>+			struct inode *dir, int dlgt)
>+{
>+	struct vfsub_args vargs;
>+
>+	LKTRTrace("hi%lu, wh %.*s\n", h_dir->i_ino, AuDLNPair(wh_dentry));
>+	AuDebugOn(!wh_dentry->d_inode || !S_ISREG(wh_dentry->d_inode->i_mode));
>+
>+	/*
>+	 * forces superio when the dir has a sticky bit.
>+	 * this may be a violation of unix fs semantics.
>+	 */
>+	vfsub_args_init(&vargs, NULL, dlgt,
>+			(h_dir->i_mode & S_ISVTX)
>+			&& wh_dentry->d_inode->i_uid != current->fsuid);
>+	return vfsub_unlink(h_dir, wh_dentry, &vargs);
>+}
>+
>+int au_wh_unlink_dentry(struct inode *h_dir, struct dentry *wh_dentry,
>+			struct dentry *dentry, struct inode *dir, int dlgt)
>+{
>+	int err;
>+
>+	LKTRTrace("hi%lu, wh %.*s, d %p\n", h_dir->i_ino,
>+		  AuDLNPair(wh_dentry), dentry);
>+	AuDebugOn((dentry && au_dbwh(dentry) < 0)
>+		  || !wh_dentry->d_inode
>+		  || !S_ISREG(wh_dentry->d_inode->i_mode));
>+
>+	err = do_unlink_wh(h_dir, wh_dentry, dir, dlgt);
>+	//if (LktrCond) err = -1; // unavailable
>+	if (!err && dentry)
>+		au_set_dbwh(dentry, -1);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int unlink_wh_name(struct dentry *h_parent, struct qstr *wh,
>+			  struct inode *dir, struct au_ndx *ndx)
>+{
>+	int err;
>+	struct inode *h_dir;
>+	struct dentry *h_dentry;
>+
>+	LKTRTrace("%.*s/%.*s\n", AuDLNPair(h_parent), AuLNPair(wh));
>+	h_dir = h_parent->d_inode;
>+
>+	/* au_test_h_perm() is already done */
>+	h_dentry = au_lkup_one(wh->name, h_parent, wh->len, ndx);
>+	//if (LktrCond) {dput(h_dentry); h_dentry = ERR_PTR(-1);}
>+	if (!IS_ERR(h_dentry)) {
>+		err = 0;
>+		if (h_dentry->d_inode && S_ISREG(h_dentry->d_inode->i_mode))
>+			err = do_unlink_wh(h_dir, h_dentry, dir,
>+					   au_ftest_ndx(ndx->flags, DLGT));
>+		dput(h_dentry);
>+	} else
>+		err = PTR_ERR(h_dentry);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static void clean_wh(struct inode *h_dir, struct dentry *wh)
>+{
>+	int err;
>+	struct vfsub_args vargs;
>+
>+	AuTraceEnter();
>+
>+	if (wh->d_inode) {
>+		vfsub_args_init(&vargs, NULL, 0, 0);
>+		err = vfsub_unlink(h_dir, wh, &vargs);
>+		if (unlikely(err))
>+			AuWarn("failed unlink %.*s (%d), ignored.\n",
>+			       AuDLNPair(wh), err);
>+	}
>+}
>+
>+static void clean_plink(struct inode *h_dir, struct dentry *plink)
>+{
>+	int err;
>+	struct vfsub_args vargs;
>+
>+	AuTraceEnter();
>+
>+	if (plink->d_inode) {
>+		vfsub_args_init(&vargs, NULL, 0, 0);
>+		err = vfsub_rmdir(h_dir, plink, &vargs);
>+		if (unlikely(err))
>+			AuWarn("failed rmdir %.*s (%d), ignored.\n",
>+			       AuDLNPair(plink), err);
>+	}
>+}
>+
>+static int test_linkable(struct inode *h_dir)
>+{
>+	if (h_dir->i_op && h_dir->i_op->link)
>+		return 0;
>+	return -ENOSYS;
>+}
>+
>+static int plink_dir(struct inode *h_dir, struct dentry *plink)
>+{
>+	int err;
>+
>+	err = -EEXIST;
>+	if (!plink->d_inode) {
>+		int mode = S_IRWXU;
>+		if (unlikely(au_test_nfs(plink->d_sb)))
>+			mode |= S_IXUGO;
>+		err = vfsub_mkdir(h_dir, plink, mode, /*dlgt*/0);
>+	} else if (S_ISDIR(plink->d_inode->i_mode))
>+		err = 0;
>+	else
>+		AuErr("unknown %.*s exists\n", AuDLNPair(plink));
>+
>+	return err;
>+}
>+
>+/*
>+ * initialize the whiteout base file/dir for @br.
>+ */
>+int au_wh_init(struct dentry *h_root, struct au_branch *br,
>+	       struct vfsmount *nfsmnt, struct super_block *sb)
>+{
>+	int err;
>+	struct dentry *wh, *plink;
>+	struct inode *h_dir;
>+	static struct qstr base_name[] = {
>+		{
>+			.name	= AUFS_WH_BASENAME,
>+			.len	= sizeof(AUFS_WH_BASENAME) - 1
>+		},
>+		{
>+			.name	= AUFS_WH_PLINKDIR,
>+			.len	= sizeof(AUFS_WH_PLINKDIR) - 1
>+		}
>+	};
>+	struct au_ndx ndx = {
>+		.nfsmnt	= nfsmnt,
>+		.flags	= 0, /* always no dlgt */
>+		.nd	= NULL,
>+		//.br	= NULL
>+	};
>+	const int do_plink = au_opt_test(au_mntflags(sb), PLINK);
>+
>+	LKTRTrace("nfsmnt %p\n", nfsmnt);
>+	BrWhMustWriteLock(br);
>+	SiMustWriteLock(sb);
>+	h_dir = h_root->d_inode;
>+
>+	/* doubly whiteouted */
>+	wh = au_wh_lkup(h_root, base_name + 0, &ndx);
>+	//if (LktrCond) {dput(wh); wh = ERR_PTR(-1);}
>+	err = PTR_ERR(wh);
>+	if (IS_ERR(wh))
>+		goto out;
>+	AuDebugOn(br->br_wh && br->br_wh != wh);
>+
>+	plink = au_wh_lkup(h_root, base_name + 1, &ndx);
>+	err = PTR_ERR(plink);
>+	if (IS_ERR(plink))
>+		goto out_dput_wh;
>+	AuDebugOn(br->br_plink && br->br_plink != plink);
>+
>+	dput(br->br_wh);
>+	dput(br->br_plink);
>+	br->br_wh = NULL;
>+	br->br_plink = NULL;
>+
>+	err = 0;
>+	switch (br->br_perm) {
>+	case AuBr_RR:
>+	case AuBr_RO:
>+	case AuBr_RRWH:
>+	case AuBr_ROWH:
>+		clean_wh(h_dir, wh);
>+		clean_plink(h_dir, plink);
>+		break;
>+
>+	case AuBr_RWNoLinkWH:
>+		clean_wh(h_dir, wh);
>+		if (do_plink) {
>+			err = test_linkable(h_dir);
>+			if (unlikely(err))
>+				goto out_nolink;
>+
>+			err = plink_dir(h_dir, plink);
>+			if (unlikely(err))
>+				goto out_err;
>+			br->br_plink = dget(plink);
>+		} else
>+			clean_plink(h_dir, plink);
>+		break;
>+
>+	case AuBr_RW:
>+		/*
>+		 * for the moment, aufs supports the branch filesystem
>+		 * which does not support link(2).
>+		 * testing on FAT which does not support i_op->setattr() fully
>+		 * either, copyup failed.
>+		 * finally, such filesystem will not be used as the writable
>+		 * branch.
>+		 */
>+		err = test_linkable(h_dir);
>+		if (unlikely(err))
>+			goto out_nolink;
>+
>+		err = -EEXIST;
>+		if (!wh->d_inode)
>+			err = au_h_create(h_dir, wh, WH_MASK, /*dlgt*/0,
>+					  /*nd*/NULL, nfsmnt);
>+		else if (S_ISREG(wh->d_inode->i_mode))
>+			err = 0;
>+		else
>+			AuErr("unknown %.*s/%.*s exists\n",
>+			      AuDLNPair(h_root), AuDLNPair(wh));
>+		if (unlikely(err))
>+			goto out_err;
>+
>+		if (do_plink) {
>+			err = plink_dir(h_dir, plink);
>+			if (unlikely(err))
>+				goto out_err;
>+			br->br_plink = dget(plink);
>+		} else
>+			clean_plink(h_dir, plink);
>+		br->br_wh = dget(wh);
>+		break;
>+
>+	default:
>+		BUG();
>+	}
>+
>+ out_dput:
>+	dput(plink);
>+ out_dput_wh:
>+	dput(wh);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+ out_nolink:
>+	AuErr("%.*s doesn't support link(2), use noplink and rw+nolwh\n",
>+	      AuDLNPair(h_root));
>+	goto out_dput;
>+ out_err:
>+	AuErr("an error(%d) on the writable branch %.*s(%s)\n",
>+	      err, AuDLNPair(h_root), au_sbtype(h_root->d_sb));
>+	goto out_dput;
>+}
>+
>+struct reinit_br_wh {
>+	struct super_block *sb;
>+	struct au_branch *br;
>+};
>+
>+static void reinit_br_wh(void *arg)
>+{
>+	int err;
>+	struct reinit_br_wh *a = arg;
>+	struct inode *h_dir, *dir;
>+	struct dentry *h_root;
>+	aufs_bindex_t bindex;
>+	struct vfsub_args vargs;
>+
>+	AuTraceEnter();
>+	AuDebugOn(!a->br->br_wh || !a->br->br_wh->d_inode || current->fsuid);
>+
>+	err = 0;
>+	/* big aufs lock */
>+	si_write_lock(a->sb);
>+	if (unlikely(!au_br_writable(a->br->br_perm)))
>+		goto out;
>+	bindex = au_br_index(a->sb, a->br->br_id);
>+	if (unlikely(bindex < 0))
>+		goto out;
>+
>+	dir = a->sb->s_root->d_inode;
>+	h_root = dget_parent(a->br->br_wh);
>+	h_dir = h_root->d_inode;
>+	AuDebugOn(!h_dir->i_op || !h_dir->i_op->link);
>+	vfsub_args_init(&vargs, NULL, /*dlgt*/0, 0);
>+	au_hdir_lock(h_dir, dir, bindex);
>+	br_wh_write_lock(a->br);
>+	err = vfsub_unlink(h_dir, a->br->br_wh, &vargs);
>+	//if (LktrCond) err = -1;
>+	dput(a->br->br_wh);
>+	a->br->br_wh = NULL;
>+	if (!err)
>+		err = au_wh_init(h_root, a->br, au_do_nfsmnt(a->br->br_mnt),
>+				 a->sb);
>+	br_wh_write_unlock(a->br);
>+	au_hdir_unlock(h_dir, dir, bindex);
>+	dput(h_root);
>+
>+ out:
>+	atomic_dec_return(&a->br->br_wh_running);
>+	au_br_put(a->br);
>+	si_write_unlock(a->sb);
>+	kfree(arg);
>+	if (unlikely(err))
>+		AuIOErr("err %d\n", err);
>+}
>+
>+static void kick_reinit_br_wh(struct super_block *sb, struct au_branch *br)
>+{
>+	int do_dec, wkq_err;
>+	struct reinit_br_wh *arg;
>+
>+	do_dec = 1;
>+	if (atomic_inc_return(&br->br_wh_running) != 1)
>+		goto out;
>+
>+	/* ignore ENOMEM */
>+	arg = kmalloc(sizeof(*arg), GFP_TEMPORARY);
>+	if (arg) {
>+		/*
>+		 * dec(wh_running), kfree(arg) and au_br_put()
>+		 * in reinit function
>+		 */
>+		arg->sb = sb;
>+		arg->br = br;
>+		au_br_get(br);
>+		wkq_err = au_wkq_nowait(reinit_br_wh, arg, sb, /*dlgt*/0);
>+		if (unlikely(wkq_err)) {
>+			atomic_dec_return(&br->br_wh_running);
>+			au_br_put(br);
>+			kfree(arg);
>+		}
>+		do_dec = 0;
>+	}
>+
>+ out:
>+	if (do_dec)
>+		atomic_dec_return(&br->br_wh_running);
>+}
>+
>+/*
>+ * create the whiteout @wh.
>+ */
>+static int link_or_create_wh(struct dentry *wh, struct super_block *sb,
>+			     aufs_bindex_t bindex, struct inode *dir)
>+{
>+	int err, dlgt;
>+	struct au_branch *br;
>+	struct dentry *h_parent;
>+	struct inode *h_dir;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(wh));
>+	SiMustReadLock(sb);
>+	h_parent = wh->d_parent; /* dir inode is locked */
>+	h_dir = h_parent->d_inode;
>+	IMustLock(h_dir);
>+
>+	dlgt = !!au_opt_test_dlgt(au_mntflags(sb));
>+	br = au_sbr(sb, bindex);
>+	br_wh_read_lock(br);
>+	if (br->br_wh) {
>+		err = vfsub_link(br->br_wh, h_dir, wh, dlgt);
>+		if (!err || err != -EMLINK)
>+			goto out;
>+
>+		/* link count full. re-initialize br_wh. */
>+		kick_reinit_br_wh(sb, br);
>+	}
>+
>+	/* return this error in this context */
>+	err = au_h_create(h_dir, wh, WH_MASK, dlgt, /*nd*/NULL,
>+			  au_do_nfsmnt(br->br_mnt));
>+
>+ out:
>+	br_wh_read_unlock(br);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * create or remove the diropq.
>+ */
>+static struct dentry *do_diropq(struct dentry *dentry, aufs_bindex_t bindex,
>+				unsigned int flags)
>+{
>+	struct dentry *opq_dentry, *h_dentry;
>+	struct inode *h_dir;
>+	int err, dlgt;
>+	struct super_block *sb;
>+	struct au_ndx ndx = {
>+		.flags	= 0,
>+		.nd	= NULL,
>+		//.br	= NULL
>+	};
>+
>+	LKTRTrace("%.*s, bindex %d, flags 0x%x\n",
>+		  AuDLNPair(dentry), bindex, flags);
>+	h_dentry = au_h_dptr(dentry, bindex);
>+	AuDebugOn(!h_dentry);
>+	h_dir = h_dentry->d_inode;
>+	AuDebugOn(!h_dir || !S_ISDIR(h_dir->i_mode));
>+
>+	/* already checked by au_test_h_perm(). */
>+	sb = dentry->d_sb;
>+	ndx.nfsmnt = au_nfsmnt(sb, bindex);
>+	dlgt = 0;
>+	if (unlikely(au_ftest_diropq(flags, DLGT))) {
>+		dlgt = 1;
>+		au_fset_ndx(ndx.flags, DLGT);
>+	}
>+	opq_dentry = au_lkup_one(diropq_name.name, h_dentry, diropq_name.len,
>+				 &ndx);
>+	//if (LktrCond) {dput(opq_dentry); opq_dentry = ERR_PTR(-1);}
>+	if (IS_ERR(opq_dentry))
>+		goto out;
>+
>+	if (au_ftest_diropq(flags, CREATE)) {
>+		AuDebugOn(opq_dentry->d_inode);
>+		err = link_or_create_wh(opq_dentry, sb, bindex,
>+					dentry->d_inode);
>+		//if (LktrCond) {vfs_unlink(h_dir, opq_dentry); err = -1;}
>+		if (!err) {
>+			au_set_dbdiropq(dentry, bindex);
>+			goto out; /* success */
>+		}
>+	} else {
>+		AuDebugOn(/* !S_ISDIR(dentry->d_inode->i_mode)
>+			   * ||  */!opq_dentry->d_inode);
>+		err = do_unlink_wh(h_dir, opq_dentry, dentry->d_inode, dlgt);
>+		//if (LktrCond) err = -1;
>+		if (!err)
>+			au_set_dbdiropq(dentry, -1);
>+	}
>+	dput(opq_dentry);
>+	opq_dentry = ERR_PTR(err);
>+
>+ out:
>+	AuTraceErrPtr(opq_dentry);
>+	return opq_dentry;
>+}
>+
>+struct do_diropq_args {
>+	struct dentry **errp;
>+	struct dentry *dentry;
>+	aufs_bindex_t bindex;
>+	unsigned int flags;
>+};
>+
>+static void call_do_diropq(void *args)
>+{
>+	struct do_diropq_args *a = args;
>+	*a->errp = do_diropq(a->dentry, a->bindex, a->flags);
>+}
>+
>+struct dentry *au_diropq_sio(struct dentry *dentry, aufs_bindex_t bindex,
>+			     unsigned int flags)
>+{
>+	struct dentry *diropq, *h_dentry;
>+
>+	LKTRTrace("%.*s, bindex %d, flags 0x%x\n",
>+		  AuDLNPair(dentry), bindex, flags);
>+
>+	h_dentry = au_h_dptr(dentry, bindex);
>+	if (!au_test_h_perm_sio(h_dentry->d_inode, MAY_EXEC | MAY_WRITE,
>+				au_ftest_diropq(flags, DLGT)))
>+		diropq = do_diropq(dentry, bindex, flags);
>+	else {
>+		int wkq_err;
>+		struct do_diropq_args args = {
>+			.errp		= &diropq,
>+			.dentry		= dentry,
>+			.bindex		= bindex,
>+			.flags		= flags
>+		};
>+		wkq_err = au_wkq_wait(call_do_diropq, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			diropq = ERR_PTR(wkq_err);
>+	}
>+
>+	AuTraceErrPtr(diropq);
>+	return diropq;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * lookup whiteout dentry.
>+ * @h_parent: hidden parent dentry which must exist and be locked
>+ * @base_name: name of dentry which will be whiteouted
>+ * returns dentry for whiteout.
>+ */
>+struct dentry *au_wh_lkup(struct dentry *h_parent, struct qstr *base_name,
>+			  struct au_ndx *ndx)
>+{
>+	int err;
>+	struct qstr wh_name;
>+	struct dentry *wh_dentry;
>+
>+	LKTRTrace("%.*s/%.*s\n", AuDLNPair(h_parent), AuLNPair(base_name));
>+
>+	err = au_wh_name_alloc(base_name->name, base_name->len, &wh_name);
>+	//if (LktrCond) {au_wh_name_free(&wh_name); err = -1;}
>+	wh_dentry = ERR_PTR(err);
>+	if (!err) {
>+		/* do not superio. */
>+		wh_dentry = au_lkup_one(wh_name.name, h_parent,
>+					wh_name.len, ndx);
>+		au_wh_name_free(&wh_name);
>+	}
>+	AuTraceErrPtr(wh_dentry);
>+	return wh_dentry;
>+}
>+
>+/*
>+ * link/create a whiteout for @dentry on @bindex.
>+ */
>+struct dentry *au_wh_create(struct inode *dir, struct dentry *dentry,
>+			    aufs_bindex_t bindex, struct dentry *h_parent,
>+			    struct au_ndx *ndx)
>+{
>+	struct dentry *wh_dentry;
>+	int err;
>+	struct super_block *sb;
>+
>+	LKTRTrace("%.*s/%.*s on b%d\n", AuDLNPair(h_parent),
>+		  AuDLNPair(dentry), bindex);
>+
>+	sb = dentry->d_sb;
>+	wh_dentry = au_wh_lkup(h_parent, &dentry->d_name, ndx);
>+	//au_nfsmnt(sb, bindex), need_dlgt(sb));
>+	//if (LktrCond) {dput(wh_dentry); wh_dentry = ERR_PTR(-1);}
>+	if (!IS_ERR(wh_dentry) && !wh_dentry->d_inode) {
>+		err = link_or_create_wh(wh_dentry, sb, bindex, dir);
>+		if (!err)
>+			au_set_dbwh(dentry, bindex);
>+		else {
>+			dput(wh_dentry);
>+			wh_dentry = ERR_PTR(err);
>+		}
>+	}
>+
>+	AuTraceErrPtr(wh_dentry);
>+	return wh_dentry;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* Delete all whiteouts in this directory on branch bindex. */
>+static int del_wh_children(struct au_nhash *whlist, struct dentry *h_parent,
>+			   aufs_bindex_t bindex, struct inode *inode,
>+			   struct au_ndx *ndx)
>+{
>+	int err, i;
>+	struct qstr wh_name;
>+	char *p;
>+	struct inode *h_dir;
>+	struct hlist_head *head;
>+	struct au_vdir_wh *tpos;
>+	struct hlist_node *pos;
>+	struct au_vdir_destr *str;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(h_parent));
>+	h_dir = h_parent->d_inode;
>+	AuDebugOn(IS_RDONLY(h_dir));
>+	//SiMustReadLock(??);
>+
>+	err = -ENOMEM;
>+	p = __getname();
>+	wh_name.name = p;
>+	//if (LktrCond) {__putname(p); wh_name.name = p = NULL;}
>+	if (unlikely(!wh_name.name))
>+		goto out;
>+	memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
>+	p += AUFS_WH_PFX_LEN;
>+
>+	/* already checked by au_test_h_perm(). */
>+	err = 0;
>+	for (i = 0; !err && i < AuSize_NHASH; i++) {
>+		head = whlist->heads + i;
>+		hlist_for_each_entry(tpos, pos, head, wh_hash) {
>+			if (tpos->wh_bindex != bindex)
>+				continue;
>+			str = &tpos->wh_str;
>+			if (str->len + AUFS_WH_PFX_LEN <= PATH_MAX) {
>+				memcpy(p, str->name, str->len);
>+				wh_name.len = AUFS_WH_PFX_LEN + str->len;
>+				err = unlink_wh_name(h_parent, &wh_name, inode,
>+						     ndx);
>+				//if (LktrCond) err = -1;
>+				if (!err)
>+					continue;
>+				break;
>+			}
>+			AuIOErr("whiteout name too long %.*s\n",
>+				str->len, str->name);
>+			err = -EIO;
>+			break;
>+		}
>+	}
>+	__putname(wh_name.name);
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+struct del_wh_children_args {
>+	int *errp;
>+	struct au_nhash *whlist;
>+	struct dentry *h_parent;
>+	aufs_bindex_t bindex;
>+	struct inode *inode;
>+	struct au_ndx *ndx;
>+};
>+
>+static void call_del_wh_children(void *args)
>+{
>+	struct del_wh_children_args *a = args;
>+	*a->errp = del_wh_children(a->whlist, a->h_parent, a->bindex,
>+				   a->inode, a->ndx);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * rmdir the whiteouted temporary named dir @h_dentry.
>+ * @whlist: whiteouted children.
>+ */
>+int au_whtmp_rmdir(struct dentry *h_dentry, struct au_nhash *whlist,
>+		   aufs_bindex_t bindex, struct inode *dir, struct inode *inode,
>+		   int noself)
>+{
>+	int err, dlgt;
>+	struct inode *h_inode, *h_dir;
>+	struct super_block *sb;
>+	unsigned int mnt_flags;
>+	struct au_hin_ignore ign;
>+	struct vfsub_args vargs;
>+	struct au_ndx ndx = {
>+		.flags	= 0,
>+		.nd	= NULL,
>+		//.br	= NULL
>+	};
>+
>+	LKTRTrace("hd %.*s, b%d, i%lu\n",
>+		  AuDLNPair(h_dentry), bindex, dir->i_ino);
>+	IMustLock(dir);
>+	IiMustAnyLock(dir);
>+	h_dir = h_dentry->d_parent->d_inode; /* dir inode is locked */
>+	IMustLock(h_dir);
>+
>+	sb = inode->i_sb;
>+	mnt_flags = au_mntflags(sb);
>+	dlgt = !!au_opt_test_dlgt(mnt_flags);
>+	if (unlikely(dlgt))
>+		au_fset_ndx(ndx.flags, DLGT);
>+	ndx.nfsmnt = au_nfsmnt(sb, bindex);
>+	h_inode = h_dentry->d_inode;
>+	AuDebugOn(h_inode != au_h_iptr(inode, bindex));
>+	au_hdir2_lock(h_inode, inode, bindex);
>+
>+	/*
>+	 * someone else might change some whiteouts while we were sleeping.
>+	 * it means this whlist may have an obsoleted entry.
>+	 */
>+	if (!au_test_h_perm_sio(h_inode, MAY_EXEC | MAY_WRITE, dlgt))
>+		err = del_wh_children(whlist, h_dentry, bindex, inode, &ndx);
>+	else {
>+		int wkq_err;
>+		/* ugly */
>+		unsigned int flags = ndx.flags;
>+		struct del_wh_children_args args = {
>+			.errp		= &err,
>+			.whlist		= whlist,
>+			.h_parent	= h_dentry,
>+			.bindex		= bindex,
>+			.inode		= inode,
>+			.ndx		= &ndx
>+		};
>+
>+		ndx.flags = 0;
>+		wkq_err = au_wkq_wait(call_del_wh_children, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+		ndx.flags = flags;
>+	}
>+	au_hdir_unlock(h_inode, inode, bindex);
>+
>+	if (!err) {
>+		vfsub_args_init(&vargs, &ign, dlgt, 0);
>+		if (unlikely(au_opt_test(mnt_flags, UDBA_INOTIFY) && !noself))
>+			vfsub_ign_hinode(&vargs, IN_DELETE_SELF,
>+					 au_hi(inode, bindex));
>+		err = vfsub_rmdir(h_dir, h_dentry, &vargs);
>+		//d_drop(h_dentry);
>+		//if (LktrCond) err = -1;
>+	}
>+
>+	if (!err) {
>+		if (au_ibstart(dir) == bindex) {
>+			au_cpup_attr_timesizes(dir);
>+			//au_cpup_attr_nlink(dir);
>+			drop_nlink(dir);
>+		}
>+		return 0; /* success */
>+	}
>+
>+	AuWarn("failed removing %.*s(%d), ignored\n", AuDLNPair(h_dentry), err);
>+	return err;
>+}
>+
>+static void au_whtmp_rmdir_free_args(struct au_whtmp_rmdir_args *args)
>+{
>+	dput(args->h_dentry);
>+	au_nhash_fin(&args->whlist);
>+	iput(args->inode);
>+	mutex_unlock(&args->dir->i_mutex);
>+	iput(args->dir);
>+	kfree(args);
>+}
>+
>+static void do_rmdir_whtmp(void *args)
>+{
>+	int err;
>+	struct au_whtmp_rmdir_args *a = args;
>+	struct super_block *sb;
>+
>+	LKTRTrace("%.*s, b%d, dir i%lu\n",
>+		  AuDLNPair(a->h_dentry), a->bindex, a->dir->i_ino);
>+
>+	mutex_lock(&a->dir->i_mutex);
>+	sb = a->dir->i_sb;
>+	//AuDbgSleep(3);
>+	si_noflush_read_lock(sb);
>+	err = au_test_ro(sb, a->bindex, NULL);
>+	if (!err) {
>+		struct dentry *h_parent = dget_parent(a->h_dentry);
>+		struct inode *h_dir = h_parent->d_inode;
>+
>+		ii_write_lock_child(a->inode);
>+		ii_write_lock_parent(a->dir);
>+		au_hdir_lock(h_dir, a->dir, a->bindex);
>+		err = au_whtmp_rmdir(a->h_dentry, &a->whlist, a->bindex,
>+				     a->dir, a->inode, a->noself);
>+		au_hdir_unlock(h_dir, a->dir, a->bindex);
>+		ii_write_unlock(a->dir);
>+		ii_write_unlock(a->inode);
>+		dput(h_parent);
>+	}
>+	si_read_unlock(sb);
>+	au_whtmp_rmdir_free_args(a);
>+	if (unlikely(err))
>+		AuIOErr("err %d\n", err);
>+}
>+
>+void au_whtmp_kick_rmdir(struct dentry *h_dentry, struct au_nhash *whlist,
>+			 aufs_bindex_t bindex, struct inode *dir,
>+			 struct inode *inode, int noself,
>+			 struct au_whtmp_rmdir_args *args)
>+{
>+	int wkq_err;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(h_dentry));
>+	IMustLock(dir);
>+
>+	/* all post-process will be done in do_rmdir_whtmp(). */
>+	args->h_dentry = dget(h_dentry);
>+	au_nhash_init(&args->whlist);
>+	au_nhash_move(&args->whlist, whlist);
>+	args->bindex = bindex;
>+	args->dir = igrab(dir);
>+	args->inode = igrab(inode);
>+	args->noself = noself;
>+	wkq_err = au_wkq_nowait(do_rmdir_whtmp, args, dir->i_sb, /*dlgt*/0);
>+	if (unlikely(wkq_err)) {
>+		AuWarn("rmdir error %.*s (%d), ignored\n",
>+		       AuDLNPair(h_dentry), wkq_err);
>+		au_whtmp_rmdir_free_args(args);
>+	}
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/whout.h linux-2.6.25.4-unionfs/fs/aufs/whout.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/whout.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/whout.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,140 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * whiteout for logical deletion and opaque directory
>+ *
>+ * $Id: whout.h,v 1.2 2008/04/21 02:00:37 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_WHOUT_H__
>+#define __AUFS_WHOUT_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/aufs_type.h>
>+#include "dir.h"
>+#include "opts.h"
>+#include "super.h"
>+
>+int au_wh_name_alloc(const char *name, int len, struct qstr *wh);
>+void au_wh_name_free(struct qstr *wh);
>+
>+struct au_ndx;
>+int au_wh_test(struct dentry *h_parent, struct qstr *wh_name, int try_sio,
>+	       struct au_ndx *ndx);
>+int au_diropq_test(struct dentry *h_dentry, struct au_ndx *ndx);
>+
>+struct dentry *au_whtmp_lkup(struct dentry *h_parent, struct qstr *prefix,
>+			     struct au_ndx *ndx);
>+int au_whtmp_ren(struct inode *dir, struct dentry *dentry, aufs_bindex_t bindex,
>+		 int noself);
>+int au_wh_unlink_dentry(struct inode *h_dir, struct dentry *wh_dentry,
>+			struct dentry *dentry, struct inode *dir, int dlgt);
>+
>+struct au_branch;
>+int au_wh_init(struct dentry *h_parent, struct au_branch *br,
>+	       struct vfsmount *nfsmnt, struct super_block *sb);
>+
>+/* diropq flags */
>+#define AuDiropq_CREATE	1
>+#define AuDiropq_DLGT	(1 << 1)
>+#define au_ftest_diropq(flags, name)	((flags) & AuDiropq_##name)
>+#define au_fset_diropq(flags, name)	{ (flags) |= AuDiropq_##name; }
>+#define au_fclr_diropq(flags, name)	{ (flags) &= ~AuDiropq_##name; }
>+#ifndef CONFIG_AUFS_DLGT
>+#undef AuDiropq_DLGT
>+#define AuDiropq_DLGT	0
>+#endif
>+
>+struct dentry *au_diropq_sio(struct dentry *dentry, aufs_bindex_t bindex,
>+			     unsigned int flags);
>+
>+struct dentry *au_wh_lkup(struct dentry *h_parent, struct qstr *base_name,
>+			  struct au_ndx *ndx);
>+struct dentry *au_wh_create(struct inode *dir, struct dentry *dentry,
>+			    aufs_bindex_t bindex, struct dentry *h_parent,
>+			    struct au_ndx *ndx);
>+
>+/* real rmdir the whiteout-ed dir */
>+struct au_whtmp_rmdir_args {
>+	struct dentry *h_dentry;
>+	struct au_nhash whlist;
>+	aufs_bindex_t bindex;
>+	struct inode *dir, *inode;
>+	int noself;
>+};
>+
>+struct au_nhash;
>+int au_whtmp_rmdir(struct dentry *h_dentry, struct au_nhash *whlist,
>+		   aufs_bindex_t bindex, struct inode *dir, struct inode *inode,
>+		   int noself);
>+void au_whtmp_kick_rmdir(struct dentry *h_dentry, struct au_nhash *whlist,
>+			 aufs_bindex_t bindex, struct inode *dir,
>+			 struct inode *inode, int noself,
>+			 struct au_whtmp_rmdir_args *args);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline
>+struct dentry *au_diropq_create(struct dentry *dentry, aufs_bindex_t bindex,
>+				int dlgt)
>+{
>+	unsigned int flags = AuDiropq_CREATE;
>+	if (unlikely(dlgt))
>+		au_fset_diropq(flags, DLGT);
>+	return au_diropq_sio(dentry, bindex, flags);
>+}
>+
>+static inline
>+int au_diropq_remove(struct dentry *dentry, aufs_bindex_t bindex, int dlgt)
>+{
>+	unsigned int flags = !AuDiropq_CREATE;
>+	if (unlikely(dlgt))
>+		au_fset_diropq(flags, DLGT);
>+	return PTR_ERR(au_diropq_sio(dentry, bindex, flags));
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#ifdef CONFIG_AUFS_ROBR
>+/* robr.c */
>+int au_test_robr_wh(struct qstr *name, struct dentry *h_parent,
>+		    struct qstr *wh_name, int try_sio, struct au_ndx *ndx);
>+int au_test_robr_shwh(struct super_block *sb, const struct qstr *name);
>+#else
>+static inline
>+int au_test_robr_wh(struct qstr *name, struct dentry *h_parent,
>+		    struct qstr *wh_name, int try_sio, struct au_ndx *ndx)
>+{
>+	return au_wh_test(h_parent, wh_name, try_sio, ndx);
>+}
>+
>+static inline
>+int au_test_robr_shwh(struct super_block *sb, const struct qstr *name)
>+{
>+	if (unlikely(!au_opt_test(au_mntflags(sb), SHWH)
>+		     && !strncmp(name->name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)))
>+		return -EPERM;
>+	return 0;
>+}
>+#endif /* CONFIG_AUFS_ROBR */
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_WHOUT_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/wkq.c linux-2.6.25.4-unionfs/fs/aufs/wkq.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/wkq.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/wkq.c	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,297 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * workqueue for asynchronous/super-io/delegated operations
>+ *
>+ * $Id: wkq.c,v 1.4 2008/05/04 23:53:38 sfjro Exp $
>+ */
>+
>+#include <linux/module.h>
>+#include "aufs.h"
>+
>+struct au_wkq *au_wkq;
>+
>+struct au_cred {
>+#ifdef CONFIG_AUFS_DLGT
>+	int umask;
>+	uid_t fsuid;
>+	gid_t fsgid;
>+	kernel_cap_t cap_effective, cap_inheritable, cap_permitted;
>+	//unsigned keep_capabilities:1;
>+	//struct user_struct *user;
>+	//struct fs_struct *fs;
>+	//struct nsproxy *nsproxy;
>+#endif
>+};
>+
>+struct au_wkinfo {
>+	struct work_struct wk;
>+	struct vfsmount *mnt;
>+
>+	unsigned int flags;
>+	struct au_cred cred;
>+
>+	au_wkq_func_t func;
>+	void *args;
>+
>+	atomic_t *busyp;
>+	struct completion *comp;
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#ifdef CONFIG_AUFS_DLGT
>+static void cred_store(struct au_cred *cred)
>+{
>+	cred->umask = current->fs->umask;
>+	cred->fsuid = current->fsuid;
>+	cred->fsgid = current->fsgid;
>+	cred->cap_effective = current->cap_effective;
>+	cred->cap_inheritable = current->cap_inheritable;
>+	cred->cap_permitted = current->cap_permitted;
>+}
>+
>+static void cred_revert(struct au_cred *cred)
>+{
>+	AuDebugOn(!au_test_wkq(current));
>+	current->fs->umask = cred->umask;
>+	current->fsuid = cred->fsuid;
>+	current->fsgid = cred->fsgid;
>+	current->cap_effective = cred->cap_effective;
>+	current->cap_inheritable = cred->cap_inheritable;
>+	current->cap_permitted = cred->cap_permitted;
>+}
>+
>+static void cred_switch(struct au_cred *old, struct au_cred *new)
>+{
>+	cred_store(old);
>+	cred_revert(new);
>+}
>+
>+static void dlgt_cred_store(unsigned int flags, struct au_wkinfo *wkinfo)
>+{
>+	if (unlikely(au_ftest_wkq(flags, DLGT)))
>+		cred_store(&wkinfo->cred);
>+}
>+
>+static void dlgt_func(struct au_wkinfo *wkinfo)
>+{
>+	if (!au_ftest_wkq(wkinfo->flags, DLGT))
>+		wkinfo->func(wkinfo->args);
>+	else {
>+		struct au_cred cred;
>+		cred_switch(&cred, &wkinfo->cred);
>+		wkinfo->func(wkinfo->args);
>+		cred_revert(&cred);
>+	}
>+}
>+#else
>+static void dlgt_cred_store(unsigned int flags, struct au_wkinfo *wkinfo)
>+{
>+	/* empty */
>+}
>+
>+static void dlgt_func(struct au_wkinfo *wkinfo)
>+{
>+	wkinfo->func(wkinfo->args);
>+}
>+#endif /* CONFIG_AUFS_DLGT */
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static void update_busy(struct au_wkq *wkq, struct au_wkinfo *wkinfo)
>+{
>+#ifdef CONFIG_AUFS_STAT
>+	unsigned int new, old;
>+
>+	do {
>+		new = atomic_read(wkinfo->busyp);
>+		old = wkq->max_busy;
>+		if (new <= old)
>+			break;
>+	} while (cmpxchg(&wkq->max_busy, old, new) == old);
>+#endif
>+}
>+
>+static int enqueue(struct au_wkq *wkq, struct au_wkinfo *wkinfo)
>+{
>+	AuTraceEnter();
>+	wkinfo->busyp = &wkq->busy;
>+	update_busy(wkq, wkinfo);
>+	if (au_ftest_wkq(wkinfo->flags, WAIT))
>+		return !queue_work(wkq->q, &wkinfo->wk);
>+	else
>+		return !schedule_work(&wkinfo->wk);
>+}
>+
>+static void do_wkq(struct au_wkinfo *wkinfo)
>+{
>+	unsigned int idle, n;
>+	int i, idle_idx;
>+
>+	AuTraceEnter();
>+
>+	while (1) {
>+		if (au_ftest_wkq(wkinfo->flags, WAIT)) {
>+			idle_idx = 0;
>+			idle = UINT_MAX;
>+			for (i = 0; i < aufs_nwkq; i++) {
>+				n = atomic_inc_return(&au_wkq[i].busy);
>+				if (n == 1 && !enqueue(au_wkq + i, wkinfo))
>+					return; /* success */
>+
>+				if (n < idle) {
>+					idle_idx = i;
>+					idle = n;
>+				}
>+				atomic_dec_return(&au_wkq[i].busy);
>+			}
>+		} else
>+			idle_idx = aufs_nwkq;
>+
>+		atomic_inc_return(&au_wkq[idle_idx].busy);
>+		if (!enqueue(au_wkq + idle_idx, wkinfo))
>+			return; /* success */
>+
>+		/* impossible? */
>+		AuWarn1("failed to queue_work()\n");
>+		yield();
>+	}
>+}
>+
>+static void wkq_func(struct work_struct *wk)
>+{
>+	struct au_wkinfo *wkinfo = container_of(wk, struct au_wkinfo, wk);
>+
>+	LKTRTrace("wkinfo{0x%x, %p, %p, %p}\n",
>+		  wkinfo->flags, wkinfo->func, wkinfo->busyp, wkinfo->comp);
>+
>+	dlgt_func(wkinfo);
>+	atomic_dec_return(wkinfo->busyp);
>+	if (au_ftest_wkq(wkinfo->flags, WAIT))
>+		complete(wkinfo->comp);
>+	else {
>+		mntput(wkinfo->mnt);
>+		module_put(THIS_MODULE);
>+		kfree(wkinfo);
>+	}
>+}
>+
>+int au_wkq_run(au_wkq_func_t func, void *args, struct super_block *sb,
>+	       unsigned int flags)
>+{
>+	int err;
>+	//int queued;
>+	//struct workqueue_struct *wkq;
>+	DECLARE_COMPLETION_ONSTACK(comp);
>+	struct au_wkinfo _wkinfo = {
>+		//.sb	= sb,
>+		.flags	= flags,
>+		.func	= func,
>+		.args	= args,
>+		.comp	= &comp
>+	}, *wkinfo = &_wkinfo;
>+
>+	LKTRTrace("0x%x\n", flags);
>+	AuDebugOn(au_test_wkq(current));
>+
>+	err = 0;
>+	if (unlikely(!au_ftest_wkq(flags, WAIT))) {
>+		AuDebugOn(!sb);
>+		/*
>+		 * wkq_func() must free this wkinfo.
>+		 * it highly depends upon the implementation of workqueue.
>+		 */
>+		err = -ENOMEM;
>+		wkinfo = kmalloc(sizeof(*wkinfo), GFP_TEMPORARY);
>+		if (unlikely(!wkinfo))
>+			goto out;
>+		err = 0;
>+		/* prohibit umount */
>+		wkinfo->mnt = au_mntcache_get(sb);
>+		wkinfo->flags = flags;
>+		wkinfo->func = func;
>+		wkinfo->args = args;
>+		wkinfo->comp = NULL;
>+		__module_get(THIS_MODULE);
>+	}
>+
>+	INIT_WORK(&wkinfo->wk, wkq_func);
>+	dlgt_cred_store(flags, wkinfo);
>+	do_wkq(wkinfo);
>+	if (au_ftest_wkq(flags, WAIT))
>+		/* no timeout, no interrupt */
>+		wait_for_completion(wkinfo->comp);
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+void au_wkq_fin(void)
>+{
>+	int i;
>+
>+	AuTraceEnter();
>+
>+	for (i = 0; i < aufs_nwkq; i++)
>+		if (au_wkq[i].q && !IS_ERR(au_wkq[i].q))
>+			destroy_workqueue(au_wkq[i].q);
>+	kfree(au_wkq);
>+}
>+
>+int __init au_wkq_init(void)
>+{
>+	int err, i;
>+	struct au_wkq *nowaitq;
>+
>+	LKTRTrace("%d\n", aufs_nwkq);
>+
>+	/* '+1' is for accounting  of nowait queue */
>+	err = -ENOMEM;
>+	au_wkq = kcalloc(aufs_nwkq + 1, sizeof(*au_wkq), GFP_KERNEL);
>+	if (unlikely(!au_wkq))
>+		goto out;
>+
>+	err = 0;
>+	for (i = 0; i < aufs_nwkq; i++) {
>+		au_wkq[i].q = create_singlethread_workqueue(AUFS_WKQ_NAME);
>+		if (au_wkq[i].q && !IS_ERR(au_wkq[i].q)) {
>+			atomic_set(&au_wkq[i].busy, 0);
>+			au_wkq[i].max_busy = 0;
>+			continue;
>+		}
>+
>+		err = PTR_ERR(au_wkq[i].q);
>+		au_wkq_fin();
>+		break;
>+	}
>+
>+	/* nowait accounting */
>+	nowaitq = au_wkq + aufs_nwkq;
>+	atomic_set(&nowaitq->busy, 0);
>+	nowaitq->max_busy = 0;
>+	nowaitq->q = NULL;
>+	//smp_mb(); /* atomic_set */
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/wkq.h linux-2.6.25.4-unionfs/fs/aufs/wkq.h
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/wkq.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/wkq.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,155 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * workqueue for asynchronous/super-io/delegated operations
>+ *
>+ * $Id: wkq.h,v 1.3 2008/04/28 03:18:21 sfjro Exp $
>+ */
>+
>+#ifndef __AUFS_WKQ_H__
>+#define __AUFS_WKQ_H__
>+
>+#ifdef __KERNEL__
>+
>+#include <linux/fs.h>
>+#include <linux/sched.h>
>+#include <linux/workqueue.h>
>+#include <linux/aufs_type.h>
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* internal workqueue named AUFS_WKQ_NAME */
>+struct au_wkq {
>+	struct workqueue_struct	*q;
>+
>+	/* accounting */
>+	atomic_t		busy;
>+	unsigned int		max_busy; // todo: STAT only
>+};
>+
>+/*
>+ * in the next operation, wait for the 'nowait' tasks in system-wide workqueue
>+ */
>+struct au_nowait_tasks {
>+#ifdef CONFIG_AUFS_HINOTIFY
>+	/*
>+	 * currently, the 'nowait' task which should be waited in the next
>+	 * operation is only hinotify.
>+	 */
>+	atomic_t		nw_len;
>+	wait_queue_head_t	nw_wq;
>+#endif
>+};
>+
>+/* ---------------------------------------------------------------------- */
>+
>+extern struct au_wkq *au_wkq;
>+typedef void (*au_wkq_func_t)(void *args);
>+
>+/* wkq flags */
>+#define AuWkq_WAIT	1
>+#define AuWkq_DLGT	(1 << 1)
>+#define au_ftest_wkq(flags, name)	((flags) & AuWkq_##name)
>+#define au_fset_wkq(flags, name)	{ (flags) |= AuWkq_##name; }
>+#define au_fclr_wkq(flags, name)	{ (flags) &= ~AuWkq_##name; }
>+#ifndef CONFIG_AUFS_DLGT
>+#undef AuWkq_DLGT
>+#define AuWkq_DLGT	0
>+#endif
>+
>+int au_wkq_run(au_wkq_func_t func, void *args, struct super_block *sb,
>+	       unsigned int flags);
>+int __init au_wkq_init(void);
>+void au_wkq_fin(void);
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static inline int au_test_wkq(struct task_struct *tsk)
>+{
>+	return (!tsk->mm && !strcmp(tsk->comm, AUFS_WKQ_NAME));
>+}
>+
>+static inline int au_wkq_wait(au_wkq_func_t func, void *args, int dlgt)
>+{
>+	unsigned int flags = AuWkq_WAIT;
>+	if (unlikely(dlgt))
>+		au_fset_wkq(flags, DLGT);
>+	return au_wkq_run(func, args, /*sb*/NULL, flags);
>+}
>+
>+static inline int au_wkq_nowait(au_wkq_func_t func, void *args,
>+				struct super_block *sb, int dlgt)
>+{
>+	unsigned int flags = !AuWkq_WAIT;
>+	if (unlikely(dlgt))
>+		au_fset_wkq(flags, DLGT);
>+	return au_wkq_run(func, args, sb, flags);
>+}
>+
>+#ifdef CONFIG_AUFS_HINOTIFY
>+//todo: memory barrier?
>+static inline void au_nwt_init(struct au_nowait_tasks *nwt)
>+{
>+	atomic_set(&nwt->nw_len, 0);
>+	smp_mb(); /* atomic_set */
>+	init_waitqueue_head(&nwt->nw_wq);
>+}
>+
>+static inline int au_nwt_inc(struct au_nowait_tasks *nwt)
>+{
>+	return atomic_inc_return(&nwt->nw_len);
>+}
>+
>+static inline int au_nwt_dec(struct au_nowait_tasks *nwt)
>+{
>+	int ret = atomic_dec_return(&nwt->nw_len);
>+	if (!ret)
>+		wake_up_all(&nwt->nw_wq);
>+	return ret;
>+}
>+
>+static inline int au_nwt_flush(struct au_nowait_tasks *nwt)
>+{
>+	wait_event(nwt->nw_wq, !atomic_read(&nwt->nw_len));
>+	return 0;
>+}
>+#else
>+static inline void au_nwt_init(struct au_nowait_tasks *nwt)
>+{
>+	/* nothing */
>+}
>+
>+static inline int au_nwt_inc(struct au_nowait_tasks *nwt)
>+{
>+	return 0;
>+}
>+
>+static inline int au_nwt_dec(struct au_nowait_tasks *nwt)
>+{
>+	return 0;
>+}
>+
>+static inline int au_nwt_flush(struct au_nowait_tasks *nwt)
>+{
>+	return 0;
>+}
>+#endif /* CONFIG_AUFS_HINOTIFY */
>+
>+#endif /* __KERNEL__ */
>+#endif /* __AUFS_WKQ_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/fs/aufs/xino.c linux-2.6.25.4-unionfs/fs/aufs/xino.c
>--- linux-2.6.25.4-unionfs.orig/fs/aufs/xino.c	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/fs/aufs/xino.c	2008-05-25 11:58:53 +0300
>@@ -0,0 +1,1225 @@
>+/*
>+ * Copyright (C) 2005-2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/*
>+ * external inode number translation table and bitmap
>+ *
>+ * $Id: xino.c,v 1.6 2008/05/19 01:51:23 sfjro Exp $
>+ */
>+
>+//#include <linux/fsnotify.h>
>+//#include <linux/smp_lock.h>
>+#include <linux/uaccess.h>
>+#include "aufs.h"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static ssize_t xino_fread(au_readf_t func, struct file *file, void *buf,
>+			  size_t size, loff_t *pos)
>+{
>+	ssize_t err;
>+	mm_segment_t oldfs;
>+
>+	LKTRTrace("%.*s, sz %lu, *pos %Ld\n",
>+		  AuDLNPair(file->f_dentry), (unsigned long)size, *pos);
>+
>+	oldfs = get_fs();
>+	set_fs(KERNEL_DS);
>+	do {
>+		// signal_pending
>+		err = func(file, (char __user *)buf, size, pos);
>+	} while (err == -EAGAIN || err == -EINTR);
>+	set_fs(oldfs);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static ssize_t do_xino_fwrite(au_writef_t func, struct file *file, void *buf,
>+			      size_t size, loff_t *pos)
>+{
>+	ssize_t err;
>+	mm_segment_t oldfs;
>+
>+	lockdep_off();
>+	oldfs = get_fs();
>+	set_fs(KERNEL_DS);
>+	do {
>+		// signal_pending
>+		err = func(file, (const char __user *)buf, size, pos);
>+	} while (err == -EAGAIN || err == -EINTR);
>+	set_fs(oldfs);
>+	lockdep_on();
>+
>+	if (err >= 0)
>+		au_update_fuse_h_inode(file->f_vfsmnt, file->f_dentry);
>+	/*ignore*/
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+struct do_xino_fwrite_args {
>+	ssize_t *errp;
>+	au_writef_t func;
>+	struct file *file;
>+	void *buf;
>+	size_t size;
>+	loff_t *pos;
>+};
>+
>+static void call_do_xino_fwrite(void *args)
>+{
>+	struct do_xino_fwrite_args *a = args;
>+	*a->errp = do_xino_fwrite(a->func, a->file, a->buf, a->size, a->pos);
>+}
>+
>+static ssize_t xino_fwrite(au_writef_t func, struct file *file, void *buf,
>+			   size_t size, loff_t *pos)
>+{
>+	ssize_t err;
>+
>+	LKTRTrace("%.*s, sz %lu, *pos %Ld\n",
>+		  AuDLNPair(file->f_dentry), (unsigned long)size, *pos);
>+
>+	// signal block and no wkq?
>+	/*
>+	 * it breaks RLIMIT_FSIZE and normal user's limit,
>+	 * users should care about quota and real 'filesystem full.'
>+	 */
>+	if (!au_test_wkq(current)) {
>+		int wkq_err;
>+		struct do_xino_fwrite_args args = {
>+			.errp	= &err,
>+			.func	= func,
>+			.file	= file,
>+			.buf	= buf,
>+			.size	= size,
>+			.pos	= pos
>+		};
>+		wkq_err = au_wkq_wait(call_do_xino_fwrite, &args, /*dlgt*/0);
>+		if (unlikely(wkq_err))
>+			err = wkq_err;
>+	} else
>+		err = do_xino_fwrite(func, file, buf, size, pos);
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct xino_do_trunc_args {
>+	struct vfsmount *mnt;
>+	struct au_branch *br;
>+};
>+
>+static void xino_do_trunc(void *_args)
>+{
>+	struct xino_do_trunc_args *args = _args;
>+	struct super_block *sb;
>+	aufs_bindex_t bindex;
>+	int err;
>+	struct file *file;
>+
>+	err = 0;
>+	sb = args->mnt->mnt_sb;
>+	si_noflush_write_lock(sb);
>+	bindex = au_br_index(sb, args->br->br_id);
>+	AuDebugOn(bindex < 0);
>+	err = au_xino_trunc(sb, bindex);
>+	if (unlikely(err))
>+		goto out;
>+
>+	file = args->br->br_xino;
>+	au_update_fuse_h_inode(args->br->br_mnt, file->f_dentry); /*ignore*/
>+	if (file->f_dentry->d_inode->i_blocks >= args->br->br_xino_upper)
>+		args->br->br_xino_upper += AUFS_XINO_TRUNC_STEP;
>+	//AuDbg("%Lu\n", (unsigned long long)args->br->br_xino_upper);
>+
>+ out:
>+	si_write_unlock(sb);
>+	if (unlikely(err))
>+		AuWarn("err b%d, (%d)\n", bindex, err);
>+	au_nwt_dec(&au_sbi(sb)->si_nowait);
>+	atomic_dec_return(&args->br->br_xino_running);
>+	au_br_put(args->br);
>+	mntput(args->mnt);
>+	kfree(args);
>+}
>+
>+static void xino_try_trunc(struct super_block *sb, struct au_branch *br)
>+{
>+	struct xino_do_trunc_args *args;
>+	struct au_sbinfo *sbinfo;
>+	struct file *file = br->br_xino;
>+	int wkq_err;
>+
>+	au_update_fuse_h_inode(br->br_mnt, file->f_dentry); /*ignore*/
>+	if (file->f_dentry->d_inode->i_blocks < br->br_xino_upper)
>+		return;
>+	if (atomic_inc_return(&br->br_xino_running) > 1)
>+		goto out;
>+
>+	/* lock and kfree() will be called in trunc_xino() */
>+	args = kmalloc(sizeof(*args), GFP_TEMPORARY);
>+	if (args) {
>+		args->mnt = au_mntcache_get(sb);
>+		args->br = br;
>+		au_br_get(br);
>+		sbinfo = au_sbi(sb);
>+		au_nwt_inc(&sbinfo->si_nowait);
>+		wkq_err = au_wkq_nowait(xino_do_trunc, args, sb, /*dlgt*/0);
>+		if (!wkq_err)
>+			return; /* success */
>+
>+		AuErr("wkq %d\n", wkq_err);
>+		au_nwt_dec(&sbinfo->si_nowait);
>+		mntput(args->mnt);
>+		au_br_put(br);
>+		kfree(args);
>+	} else
>+		AuErr1("no memory\n");
>+ out:
>+	atomic_dec_return(&br->br_xino_running);
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#define Au_LOFF_MAX	((loff_t)LLONG_MAX)
>+
>+static int au_xino_do_write(au_writef_t write, struct file *file,
>+			    ino_t h_ino, struct au_xino_entry *xinoe)
>+{
>+	loff_t pos;
>+	ssize_t sz;
>+
>+	AuTraceEnter();
>+
>+	pos = h_ino;
>+	if (unlikely(Au_LOFF_MAX / sizeof(*xinoe) - 1 < pos)) {
>+		AuIOErr1("too large hi%lu\n", h_ino);
>+		return -EFBIG;
>+	}
>+	pos *= sizeof(*xinoe);
>+	sz = xino_fwrite(write, file, xinoe, sizeof(*xinoe), &pos);
>+	if (sz == sizeof(*xinoe))
>+		return 0; /* success */
>+
>+	AuIOErr("write failed (%ld)\n", (long)sz);
>+	return -EIO;
>+}
>+
>+/*
>+ * write @ino to the xinofile for the specified branch{@sb, @bindex}
>+ * at the position of @_ino.
>+ * when @ino is zero, it is written to the xinofile and means no entry.
>+ */
>+int au_xino_write(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
>+		  struct au_xino_entry *xinoe)
>+{
>+	int err;
>+	struct file *file;
>+	struct au_branch *br;
>+	unsigned int mnt_flags;
>+
>+	LKTRTrace("b%d, hi%lu, i%lu\n", bindex, h_ino, xinoe->ino);
>+	BUILD_BUG_ON(sizeof(long long) != sizeof(Au_LOFF_MAX)
>+		     || ((loff_t) - 1) > 0);
>+
>+	mnt_flags = au_mntflags(sb);
>+	if (unlikely(!au_opt_test(mnt_flags, XINO)))
>+		return 0;
>+
>+	br = au_sbr(sb, bindex);
>+	file = br->br_xino;
>+	AuDebugOn(!file);
>+
>+	err = au_xino_do_write(au_sbi(sb)->si_xwrite, file, h_ino, xinoe);
>+	if (!err) {
>+		if (unlikely(au_opt_test(mnt_flags, TRUNC_XINO)
>+			     && au_test_trunc_xino(br->br_mnt->mnt_sb)))
>+			xino_try_trunc(sb, br);
>+		return 0; /* success */
>+	}
>+
>+	AuIOErr("write failed (%d)\n", err);
>+	return -EIO;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+static const int page_bits = (int)PAGE_SIZE * BITS_PER_BYTE;
>+//static const int page_bits = 4;
>+static ino_t xib_calc_ino(unsigned long pindex, int bit)
>+{
>+	ino_t ino;
>+	AuDebugOn(bit < 0 || page_bits <= bit);
>+	ino = AUFS_FIRST_INO + pindex * page_bits + bit;
>+	return ino;
>+}
>+
>+static void xib_calc_bit(ino_t ino, unsigned long *pindex, int *bit)
>+{
>+	AuDebugOn(ino < AUFS_FIRST_INO);
>+	ino -= AUFS_FIRST_INO;
>+	*pindex = ino / page_bits;
>+	*bit = ino % page_bits;
>+}
>+
>+static int xib_pindex(struct super_block *sb, unsigned long pindex)
>+{
>+	int err;
>+	struct au_sbinfo *sbinfo;
>+	loff_t pos;
>+	ssize_t sz;
>+	struct file *xib;
>+	unsigned long *p;
>+
>+	LKTRTrace("pindex %lu\n", pindex);
>+	sbinfo = au_sbi(sb);
>+	MtxMustLock(&sbinfo->si_xib_mtx);
>+	AuDebugOn(pindex > ULONG_MAX / PAGE_SIZE
>+		  || !au_opt_test(sbinfo->si_mntflags, XINO));
>+
>+	if (pindex == sbinfo->si_xib_last_pindex)
>+		return 0;
>+
>+	xib = sbinfo->si_xib;
>+	p = sbinfo->si_xib_buf;
>+	pos = sbinfo->si_xib_last_pindex;
>+	pos *= PAGE_SIZE;
>+	sz = xino_fwrite(sbinfo->si_xwrite, xib, p, PAGE_SIZE, &pos);
>+	if (unlikely(sz != PAGE_SIZE))
>+		goto out;
>+
>+	pos = pindex;
>+	pos *= PAGE_SIZE;
>+	if (i_size_read(xib->f_dentry->d_inode) >= pos + PAGE_SIZE)
>+		sz = xino_fread(sbinfo->si_xread, xib, p, PAGE_SIZE, &pos);
>+	else {
>+		memset(p, 0, PAGE_SIZE);
>+		sz = xino_fwrite(sbinfo->si_xwrite, xib, p, PAGE_SIZE, &pos);
>+	}
>+	if (sz == PAGE_SIZE) {
>+		sbinfo->si_xib_last_pindex = pindex;
>+		return 0; /* success */
>+	}
>+
>+ out:
>+	AuIOErr1("write failed (%ld)\n", (long)sz);
>+	err = sz;
>+	if (sz >= 0)
>+		err = -EIO;
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+int au_xino_write0(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
>+		   ino_t ino)
>+{
>+	int err, bit;
>+	unsigned long pindex;
>+	struct au_sbinfo *sbinfo;
>+	struct au_xino_entry xinoe = {
>+		.ino	= 0
>+	};
>+
>+	LKTRTrace("b%d, hi%lu, i%lu\n", bindex, h_ino, ino);
>+
>+	sbinfo = au_sbi(sb);
>+	if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
>+		return 0;
>+
>+	err = 0;
>+	if (unlikely(ino)) {
>+		AuDebugOn(ino < AUFS_FIRST_INO);
>+		xib_calc_bit(ino, &pindex, &bit);
>+		AuDebugOn(page_bits <= bit);
>+		mutex_lock(&sbinfo->si_xib_mtx);
>+		err = xib_pindex(sb, pindex);
>+		if (!err) {
>+			clear_bit(bit, sbinfo->si_xib_buf);
>+			sbinfo->si_xib_next_bit = bit;
>+		}
>+		mutex_unlock(&sbinfo->si_xib_mtx);
>+	}
>+
>+	if (!err)
>+		err = au_xino_write(sb, bindex, h_ino, &xinoe);
>+	return err;
>+}
>+
>+ino_t au_xino_new_ino(struct super_block *sb)
>+{
>+	ino_t ino;
>+	struct au_sbinfo *sbinfo;
>+	int free_bit, err;
>+	unsigned long *p, pindex, ul, pend;
>+	struct file *file;
>+
>+	//au_debug_on();
>+	AuTraceEnter();
>+
>+	sbinfo = au_sbi(sb);
>+	if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
>+		return iunique(sb, AUFS_FIRST_INO);
>+
>+	mutex_lock(&sbinfo->si_xib_mtx);
>+	p = sbinfo->si_xib_buf;
>+	free_bit = sbinfo->si_xib_next_bit;
>+	//AuDbg("bit %d, pindex %d\n", free_bit, sbinfo->si_xib_last_pindex);
>+	//AuDbg("bit %d, %d\n", free_bit, test_bit(free_bit, p));
>+	if (free_bit < page_bits && !test_bit(free_bit, p))
>+		goto out; /* success */
>+	free_bit = find_first_zero_bit(p, page_bits);
>+	if (free_bit < page_bits)
>+		goto out; /* success */
>+
>+	pindex = sbinfo->si_xib_last_pindex;
>+	for (ul = pindex - 1; ul < ULONG_MAX; ul--) {
>+		err = xib_pindex(sb, ul);
>+		if (unlikely(err))
>+			goto out_err;
>+		free_bit = find_first_zero_bit(p, page_bits);
>+		if (free_bit < page_bits)
>+			goto out; /* success */
>+	}
>+
>+	file = sbinfo->si_xib;
>+	pend = i_size_read(file->f_dentry->d_inode) / PAGE_SIZE;
>+	for (ul = pindex + 1; ul <= pend; ul++) {
>+		err = xib_pindex(sb, ul);
>+		if (unlikely(err))
>+			goto out_err;
>+		free_bit = find_first_zero_bit(p, page_bits);
>+		if (free_bit < page_bits)
>+			goto out; /* success */
>+	}
>+	BUG();
>+
>+ out:
>+	set_bit(free_bit, p);
>+	sbinfo->si_xib_next_bit++;
>+	pindex = sbinfo->si_xib_last_pindex;
>+	mutex_unlock(&sbinfo->si_xib_mtx);
>+	ino = xib_calc_ino(pindex, free_bit);
>+	//AuDbg("i%lu\n", ino);
>+	LKTRTrace("i%lu\n", ino);
>+	//au_debug_off();
>+	return ino;
>+ out_err:
>+	mutex_unlock(&sbinfo->si_xib_mtx);
>+	LKTRTrace("i0\n");
>+	//au_debug_off();
>+	return 0;
>+}
>+
>+/*
>+ * read @ino from xinofile for the specified branch{@sb, @bindex}
>+ * at the position of @h_ino.
>+ * if @ino does not exist and @do_new is true, get new one.
>+ */
>+int au_xino_read(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
>+		 struct au_xino_entry *xinoe)
>+{
>+	int err;
>+	struct file *file;
>+	loff_t pos;
>+	ssize_t sz;
>+	struct au_sbinfo *sbinfo;
>+
>+	LKTRTrace("b%d, hi%lu\n", bindex, h_ino);
>+
>+	err = 0;
>+	xinoe->ino = 0;
>+	sbinfo = au_sbi(sb);
>+	if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
>+		return 0; /* no ino */
>+
>+	pos = h_ino;
>+	if (unlikely(Au_LOFF_MAX / sizeof(*xinoe) - 1 < pos)) {
>+		AuIOErr1("too large hi%lu\n", h_ino);
>+		return -EFBIG;
>+	}
>+	pos *= sizeof(*xinoe);
>+
>+	file = au_sbr(sb, bindex)->br_xino;
>+	AuDebugOn(!file);
>+	if (i_size_read(file->f_dentry->d_inode) < pos + sizeof(*xinoe))
>+		return 0; /* no ino */
>+
>+	sz = xino_fread(sbinfo->si_xread, file, xinoe, sizeof(*xinoe), &pos);
>+	if (sz == sizeof(*xinoe))
>+		return 0; /* success */
>+
>+	err = sz;
>+	if (unlikely(sz >= 0)) {
>+		err = -EIO;
>+		AuIOErr("xino read error (%ld)\n", (long)sz);
>+	}
>+
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+struct file *au_xino_create(struct super_block *sb, char *fname, int silent,
>+			    struct dentry *parent)
>+{
>+	struct file *file;
>+	int err;
>+	struct dentry *h_parent;
>+	struct inode *h_dir;
>+	struct vfsub_args vargs;
>+	//const int hinotify = au_opt_test(au_mntflags(sb), UDBA_INOTIFY);
>+
>+	LKTRTrace("%s\n", fname);
>+	//AuDebugOn(!au_opt_test(au_mntflags(sb), XINO));
>+
>+	/* LSM may detect it */
>+	file = vfsub_filp_open(fname, O_RDWR | O_CREAT | O_EXCL | O_LARGEFILE,
>+			       S_IRUGO | S_IWUGO);
>+	//file = ERR_PTR(-1);
>+	if (IS_ERR(file)) {
>+		if (!silent)
>+			AuErr("open %s(%ld)\n", fname, PTR_ERR(file));
>+		return file;
>+	}
>+
>+	/* keep file count */
>+	h_parent = dget_parent(file->f_dentry);
>+	h_dir = h_parent->d_inode;
>+	vfsub_args_init(&vargs, NULL, 0, 0);
>+	mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
>+	err = vfsub_unlink(h_dir, file->f_dentry, &vargs);
>+	mutex_unlock(&h_dir->i_mutex);
>+	dput(h_parent);
>+	if (unlikely(err)) {
>+		if (!silent)
>+			AuErr("unlink %s(%d)\n", fname, err);
>+		goto out;
>+	}
>+
>+	if (sb != file->f_dentry->d_sb)
>+		return file; /* success */
>+
>+	if (!silent)
>+		AuErr("%s must be outside\n", fname);
>+	err = -EINVAL;
>+
>+ out:
>+	fput(file);
>+	file = ERR_PTR(err);
>+	return file;
>+}
>+
>+/*
>+ * find another branch who is on the same filesystem of the specified
>+ * branch{@btgt}. search until @bend.
>+ */
>+static int is_sb_shared(struct super_block *sb, aufs_bindex_t btgt,
>+			aufs_bindex_t bend)
>+{
>+	aufs_bindex_t bindex;
>+	struct super_block *tgt_sb = au_sbr_sb(sb, btgt);
>+
>+	for (bindex = 0; bindex <= bend; bindex++)
>+		if (unlikely(btgt != bindex && tgt_sb == au_sbr_sb(sb, bindex)))
>+			return bindex;
>+	return -1;
>+}
>+
>+/*
>+ * create a new xinofile at the same place/path as @base_file.
>+ */
>+static
>+struct file *au_xino_create2(struct super_block *sb, struct file *base_file,
>+			     struct file *copy_src)
>+{
>+	struct file *file;
>+	int err;
>+	struct dentry *base, *dentry, *parent;
>+	struct inode *dir, *inode;
>+	struct qstr *name;
>+	struct vfsub_args vargs;
>+	struct au_ndx ndx = {
>+		.nfsmnt	= NULL,
>+		.flags	= 0,
>+		.nd	= NULL,
>+		//.br	= NULL
>+	};
>+
>+	base = base_file->f_dentry;
>+	LKTRTrace("%.*s\n", AuDLNPair(base));
>+	parent = base->d_parent; /* dir inode is locked */
>+	dir = parent->d_inode;
>+	IMustLock(dir);
>+
>+	file = ERR_PTR(-EINVAL);
>+	if (unlikely(au_test_nfs(parent->d_sb)))
>+		goto out;
>+
>+	/* do not superio, nor NFS. */
>+	name = &base->d_name;
>+	dentry = au_lkup_one(name->name, parent, name->len, &ndx);
>+	//if (LktrCond) {dput(dentry); dentry = ERR_PTR(-1);}
>+	if (IS_ERR(dentry)) {
>+		file = (void *)dentry;
>+		AuErr("%.*s lookup err %ld\n", AuLNPair(name), PTR_ERR(dentry));
>+		goto out;
>+	}
>+	err = vfsub_create(dir, dentry, S_IRUGO | S_IWUGO, NULL, /*dlgt*/0);
>+	//if (LktrCond) {vfs_unlink(dir, dentry); err = -1;}
>+	if (unlikely(err)) {
>+		file = ERR_PTR(err);
>+		AuErr("%.*s create err %d\n", AuLNPair(name), err);
>+		goto out_dput;
>+	}
>+	file = dentry_open(dget(dentry), mntget(base_file->f_vfsmnt),
>+			   O_RDWR | O_CREAT | O_EXCL | O_LARGEFILE);
>+	//if (LktrCond) {fput(file); file = ERR_PTR(-1);}
>+	if (IS_ERR(file)) {
>+		AuErr("%.*s open err %ld\n", AuLNPair(name), PTR_ERR(file));
>+		goto out_dput;
>+	}
>+	vfsub_args_init(&vargs, NULL, 0, 0);
>+	err = vfsub_unlink(dir, dentry, &vargs);
>+	//if (LktrCond) err = -1;
>+	if (unlikely(err)) {
>+		AuErr("%.*s unlink err %d\n", AuLNPair(name), err);
>+		goto out_fput;
>+	}
>+
>+	if (copy_src) {
>+		inode = copy_src->f_dentry->d_inode;
>+		err = au_copy_file(file, copy_src, i_size_read(inode), sb);
>+		if (unlikely(err)) {
>+			AuErr("%.*s copy err %d\n", AuLNPair(name), err);
>+			goto out_fput;
>+		}
>+	}
>+	goto out_dput; /* success */
>+
>+ out_fput:
>+	fput(file);
>+	file = ERR_PTR(err);
>+ out_dput:
>+	dput(dentry);
>+ out:
>+	AuTraceErrPtr(file);
>+	return file;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * initialize the xinofile for the specified branch{@sb, @bindex}
>+ * at the place/path where @base_file indicates.
>+ * test whether another branch is on the same filesystem or not,
>+ * if @do_test is true.
>+ */
>+int au_xino_br(struct super_block *sb, struct au_branch *br, ino_t h_ino,
>+	       struct file *base_file, int do_test)
>+{
>+	int err, do_create;
>+	struct au_branch *shared_br;
>+	aufs_bindex_t bshared, bend;
>+	struct inode *dir;
>+	struct au_xino_entry xinoe;
>+	struct dentry *parent;
>+	struct file *file;
>+
>+	LKTRTrace("base_file %p, do_test %d\n", base_file, do_test);
>+	SiMustWriteLock(sb);
>+	AuDebugOn(!au_opt_test(au_mntflags(sb), XINO));
>+	AuDebugOn(br->br_xino);
>+
>+	do_create = 1;
>+	bshared = -1;
>+	shared_br = NULL;
>+	bend = au_sbend(sb);
>+	if (do_test) {
>+		aufs_bindex_t bindex;
>+
>+		struct super_block *tgt_sb = br->br_mnt->mnt_sb;
>+		for (bindex = 0; bindex <= bend; bindex++)
>+			if (unlikely(tgt_sb == au_sbr_sb(sb, bindex))) {
>+				bshared = bindex;
>+				break;
>+			}
>+	}
>+	if (unlikely(bshared >= 0)) {
>+		shared_br = au_sbr(sb, bshared);
>+		do_create = !shared_br->br_xino;
>+	}
>+
>+	if (do_create) {
>+		parent = dget_parent(base_file->f_dentry);
>+		dir = parent->d_inode;
>+
>+		mutex_lock_nested(&dir->i_mutex, AuLsc_I_PARENT);
>+		file = au_xino_create2(sb, base_file, NULL);
>+		err = PTR_ERR(file);
>+		mutex_unlock(&dir->i_mutex);
>+		dput(parent);
>+		if (IS_ERR(file))
>+			goto out;
>+		br->br_xino = file;
>+	} else {
>+		br->br_xino = shared_br->br_xino;
>+		get_file(br->br_xino);
>+	}
>+
>+	xinoe.ino = AUFS_ROOT_INO;
>+	//xinoe.h_gen = h_inode->i_generation;
>+	//WARN_ON(xinoe.h_gen == AuXino_INVALID_HGEN);
>+	err = au_xino_do_write(au_sbi(sb)->si_xwrite, br->br_xino, h_ino,
>+			       &xinoe);
>+	//if (LktrCond) err = -1;
>+	if (!err)
>+		return 0; /* success */
>+
>+	//fput(br->br_xino);
>+	//br->br_xino = NULL;
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* too slow */
>+static int do_xib_restore(struct super_block *sb, struct file *file, void *page)
>+{
>+	int err, bit;
>+	struct au_sbinfo *sbinfo;
>+	au_readf_t func;
>+	loff_t pos, pend;
>+	ssize_t sz;
>+	struct au_xino_entry *xinoe;
>+	unsigned long pindex;
>+
>+	AuTraceEnter();
>+	SiMustWriteLock(sb);
>+
>+	err = 0;
>+	sbinfo = au_sbi(sb);
>+	func = sbinfo->si_xread;
>+	pend = i_size_read(file->f_dentry->d_inode);
>+#ifdef CONFIG_AUFS_DEBUG
>+	if (unlikely(pend > (1 << 22)))
>+		AuWarn("testing a large xino file %Ld\n", (long long)pend);
>+#endif
>+	pos = 0;
>+	while (pos < pend) {
>+		sz = xino_fread(func, file, page, PAGE_SIZE, &pos);
>+		err = sz;
>+		if (unlikely(sz <= 0))
>+			goto out;
>+
>+		err = 0;
>+		for (xinoe = page; sz > 0; xinoe++, sz -= sizeof(xinoe)) {
>+			//AuDbg("i%lu\n", xinoe->ino);
>+			if (unlikely(xinoe->ino < AUFS_FIRST_INO))
>+				continue;
>+
>+			xib_calc_bit(xinoe->ino, &pindex, &bit);
>+			AuDebugOn(page_bits <= bit);
>+			err = xib_pindex(sb, pindex);
>+			if (!err)
>+				set_bit(bit, sbinfo->si_xib_buf);
>+			else
>+				goto out;
>+			//AuDbg("i%lu, bit %d\n", xinoe->ino, bit);
>+		}
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+static int xib_restore(struct super_block *sb)
>+{
>+	int err;
>+	aufs_bindex_t bindex, bend;
>+	void *page;
>+
>+	//au_debug_on();
>+	AuTraceEnter();
>+
>+	err = -ENOMEM;
>+	page = (void *)__get_free_page(GFP_TEMPORARY);
>+	if (unlikely(!page))
>+		goto out;
>+
>+	err = 0;
>+	bend = au_sbend(sb);
>+	for (bindex = 0; !err && bindex <= bend; bindex++)
>+		if (!bindex || is_sb_shared(sb, bindex, bindex - 1) < 0)
>+			err = do_xib_restore
>+				(sb, au_sbr(sb, bindex)->br_xino, page);
>+		else
>+			LKTRTrace("b%d\n", bindex);
>+	free_page((unsigned long)page);
>+
>+ out:
>+	AuTraceErr(err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+int au_xib_trunc(struct super_block *sb)
>+{
>+	int err;
>+	struct au_sbinfo *sbinfo;
>+	unsigned long *p;
>+	//ino_t ino;
>+	loff_t pos;
>+	ssize_t sz;
>+	struct dentry *parent;
>+	struct inode *dir;
>+	struct file *file;
>+	unsigned int mnt_flags;
>+
>+	AuTraceEnter();
>+	SiMustWriteLock(sb);
>+
>+	mnt_flags = au_mntflags(sb);
>+	if (unlikely(!au_opt_test(mnt_flags, XINO)))
>+		return 0;
>+
>+	//aufs_debug_on();
>+	sbinfo = au_sbi(sb);
>+	parent = dget_parent(sbinfo->si_xib->f_dentry);
>+	dir = parent->d_inode;
>+	mutex_lock_nested(&dir->i_mutex, AuLsc_I_PARENT);
>+	file = au_xino_create2(sb, sbinfo->si_xib, NULL);
>+	mutex_unlock(&dir->i_mutex);
>+	dput(parent);
>+	err = PTR_ERR(file);
>+	if (IS_ERR(file))
>+		goto out;
>+	fput(sbinfo->si_xib);
>+	sbinfo->si_xib = file;
>+
>+	p = sbinfo->si_xib_buf;
>+	memset(p, 0, PAGE_SIZE);
>+	pos = 0;
>+	sz = xino_fwrite(sbinfo->si_xwrite, sbinfo->si_xib, p, PAGE_SIZE, &pos);
>+	if (unlikely(sz != PAGE_SIZE)) {
>+		err = sz;
>+		AuIOErr("err %d\n", err);
>+		if (sz >= 0)
>+			err = -EIO;
>+		goto out;
>+	}
>+
>+	if (au_opt_test(mnt_flags, XINO)) {
>+		mutex_lock(&sbinfo->si_xib_mtx);
>+		err = xib_restore(sb);
>+		mutex_unlock(&sbinfo->si_xib_mtx);
>+	}
>+
>+out:
>+	//aufs_debug_off();
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * xino mount option handlers
>+ */
>+static au_readf_t find_readf(struct file *h_file)
>+{
>+	const struct file_operations *fop = h_file->f_op;
>+
>+	if (fop) {
>+		if (fop->read)
>+			return fop->read;
>+		if (fop->aio_read)
>+			return do_sync_read;
>+	}
>+	return ERR_PTR(-ENOSYS);
>+}
>+
>+static au_writef_t find_writef(struct file *h_file)
>+{
>+	const struct file_operations *fop = h_file->f_op;
>+
>+	if (fop) {
>+		if (fop->write)
>+			return fop->write;
>+		if (fop->aio_write)
>+			return do_sync_write;
>+	}
>+	return ERR_PTR(-ENOSYS);
>+}
>+
>+/* xino bitmap */
>+static void xino_clear_xib(struct super_block *sb)
>+{
>+	struct au_sbinfo *sbinfo;
>+
>+	AuTraceEnter();
>+	SiMustWriteLock(sb);
>+
>+	sbinfo = au_sbi(sb);
>+	sbinfo->si_xread = NULL;
>+	sbinfo->si_xwrite = NULL;
>+	if (sbinfo->si_xib)
>+		fput(sbinfo->si_xib);
>+	sbinfo->si_xib = NULL;
>+	free_page((unsigned long)sbinfo->si_xib_buf);
>+	sbinfo->si_xib_buf = NULL;
>+}
>+
>+static int au_xino_set_xib(struct super_block *sb, struct file *base)
>+{
>+	int err;
>+	struct au_sbinfo *sbinfo;
>+	struct file *file;
>+	loff_t pos;
>+
>+	LKTRTrace("%.*s\n", AuDLNPair(base->f_dentry));
>+	SiMustWriteLock(sb);
>+
>+	sbinfo = au_sbi(sb);
>+	file = au_xino_create2(sb, base, sbinfo->si_xib);
>+	err = PTR_ERR(file);
>+	if (IS_ERR(file))
>+		goto out;
>+	if (sbinfo->si_xib)
>+		fput(sbinfo->si_xib);
>+	sbinfo->si_xib = file;
>+	sbinfo->si_xread = find_readf(file);
>+	AuDebugOn(IS_ERR(sbinfo->si_xread));
>+	sbinfo->si_xwrite = find_writef(file);
>+	AuDebugOn(IS_ERR(sbinfo->si_xwrite));
>+
>+	err = -ENOMEM;
>+	if (!sbinfo->si_xib_buf)
>+		sbinfo->si_xib_buf = (void *)get_zeroed_page(GFP_KERNEL);
>+	if (unlikely(!sbinfo->si_xib_buf))
>+		goto out_unset;
>+
>+	sbinfo->si_xib_last_pindex = 0;
>+	sbinfo->si_xib_next_bit = 0;
>+
>+	/* no need to lock for i_size_read() */
>+	if (i_size_read(file->f_dentry->d_inode) < PAGE_SIZE) {
>+		pos = 0;
>+		err = xino_fwrite(sbinfo->si_xwrite, file, sbinfo->si_xib_buf,
>+				  PAGE_SIZE, &pos);
>+		if (unlikely(err != PAGE_SIZE))
>+			goto out_free;
>+	}
>+	err = 0;
>+	goto out; /* success */
>+
>+ out_free:
>+	free_page((unsigned long)sbinfo->si_xib_buf);
>+	sbinfo->si_xib_buf = NULL;
>+	if (err >= 0)
>+		err = -EIO;
>+ out_unset:
>+	fput(sbinfo->si_xib);
>+	sbinfo->si_xib = NULL;
>+	sbinfo->si_xread = NULL;
>+	sbinfo->si_xwrite = NULL;
>+ out:
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+/* xino for each branch */
>+static void xino_clear_br(struct super_block *sb)
>+{
>+	aufs_bindex_t bindex, bend;
>+	struct au_branch *br;
>+
>+	AuTraceEnter();
>+	SiMustWriteLock(sb);
>+
>+	bend = au_sbend(sb);
>+	for (bindex = 0; bindex <= bend; bindex++) {
>+		br = au_sbr(sb, bindex);
>+		if (unlikely(!br || !br->br_xino))
>+			continue;
>+
>+		fput(br->br_xino);
>+		br->br_xino = NULL;
>+	}
>+}
>+
>+static int au_xino_set_br(struct super_block *sb, struct file *base)
>+{
>+	int err;
>+	aufs_bindex_t bindex, bend, bshared;
>+	struct {
>+		struct file *old, *new;
>+	} *fpair, *p;
>+	struct au_branch *br;
>+	struct au_xino_entry xinoe;
>+	struct inode *inode;
>+	au_writef_t writef;
>+
>+	//au_debug_on();
>+	LKTRTrace("%.*s\n", AuDLNPair(base->f_dentry));
>+	SiMustWriteLock(sb);
>+
>+	err = -ENOMEM;
>+	bend = au_sbend(sb);
>+	fpair = kcalloc(bend + 1, sizeof(*fpair), GFP_TEMPORARY);
>+	if (unlikely(!fpair))
>+		goto out;
>+
>+	inode = sb->s_root->d_inode;
>+	xinoe.ino = AUFS_ROOT_INO;
>+	writef = au_sbi(sb)->si_xwrite;
>+	for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++) {
>+		br = au_sbr(sb, bindex);
>+		bshared = is_sb_shared(sb, bindex, bindex - 1);
>+		if (bshared >= 0) {
>+			/* shared xino */
>+			*p = fpair[bshared];
>+			get_file(p->new);
>+		}
>+
>+		if (!p->new) {
>+			/* new xino */
>+			p->old = br->br_xino;
>+			p->new = au_xino_create2(sb, base, br->br_xino);
>+			err = PTR_ERR(p->new);
>+			if (IS_ERR(p->new)) {
>+				p->new = NULL;
>+				goto out_pair;
>+			}
>+		}
>+
>+		err = au_xino_do_write(writef, p->new,
>+				       au_h_iptr(inode, bindex)->i_ino, &xinoe);
>+		if (unlikely(err))
>+			goto out_pair;
>+	}
>+
>+	for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++) {
>+		br = au_sbr(sb, bindex);
>+		AuDebugOn(p->old != br->br_xino);
>+		if (br->br_xino)
>+			fput(br->br_xino);
>+		get_file(p->new);
>+		br->br_xino = p->new;
>+	}
>+
>+ out_pair:
>+	for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++)
>+		if (p->new)
>+			fput(p->new);
>+		else
>+			break;
>+	kfree(fpair);
>+ out:
>+	AuTraceErr(err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+void au_xino_clr(struct super_block *sb)
>+{
>+	AuTraceEnter();
>+	SiMustWriteLock(sb);
>+
>+	xino_clear_xib(sb);
>+	xino_clear_br(sb);
>+	au_opt_clr(au_sbi(sb)->si_mntflags, XINO);
>+}
>+
>+int au_xino_set(struct super_block *sb, struct au_opt_xino *xino, int remount)
>+{
>+	int err, skip;
>+	struct dentry *parent, *cur_parent;
>+	struct qstr *dname, *cur_name;
>+	struct file *cur_xino;
>+	struct inode *dir;
>+	struct au_sbinfo *sbinfo;
>+
>+	LKTRTrace("remount %d\n", remount);
>+	SiMustWriteLock(sb);
>+
>+	err = 0;
>+	sbinfo = au_sbi(sb);
>+	parent = dget_parent(xino->file->f_dentry);
>+	if (remount) {
>+		skip = 0;
>+		dname = &xino->file->f_dentry->d_name;
>+		cur_xino = sbinfo->si_xib;
>+		if (cur_xino) {
>+			cur_parent = dget_parent(cur_xino->f_dentry);
>+			cur_name = &cur_xino->f_dentry->d_name;
>+			skip = (cur_parent == parent
>+				&& dname->len == cur_name->len
>+				&& !memcmp(dname->name, cur_name->name,
>+					   dname->len));
>+			dput(cur_parent);
>+		}
>+		if (skip)
>+			goto out;
>+	}
>+
>+	au_opt_set(sbinfo->si_mntflags, XINO);
>+	dir = parent->d_inode;
>+	mutex_lock_nested(&dir->i_mutex, AuLsc_I_PARENT);
>+	err = au_xino_set_xib(sb, xino->file);
>+	if (!err)
>+		err = au_xino_set_br(sb, xino->file);
>+	mutex_unlock(&dir->i_mutex);
>+	if (!err)
>+		goto out; /* success */
>+
>+	/* reset all */
>+	AuIOErr("failed creating xino, forcing noxino (%d).\n", err);
>+	err = -EIO;
>+	au_xino_clr(sb);
>+
>+ out:
>+	dput(parent);
>+	AuTraceErr(err);
>+	return err;
>+}
>+
>+int au_xino_trunc(struct super_block *sb, aufs_bindex_t bindex)
>+{
>+	int err;
>+	struct au_branch *br;
>+	struct file *new_xino;
>+	struct super_block *h_sb;
>+	aufs_bindex_t bi, bend;
>+	struct dentry *parent;
>+	struct inode *dir;
>+
>+	//au_debug_on();
>+	LKTRTrace("b%d\n", bindex);
>+	SiMustWriteLock(sb);
>+
>+	err = -EINVAL;
>+	bend = au_sbend(sb);
>+	if (unlikely(bindex < 0 || bend < bindex))
>+		goto out;
>+	br = au_sbr(sb, bindex);
>+	if (unlikely(!br->br_xino))
>+		goto out;
>+
>+	parent = dget_parent(br->br_xino->f_dentry);
>+	dir = parent->d_inode;
>+	//AuDbgFile(br->br_xino);
>+	mutex_lock_nested(&dir->i_mutex, AuLsc_I_PARENT);
>+	new_xino = au_xino_create2(sb, br->br_xino, br->br_xino);
>+	mutex_unlock(&dir->i_mutex);
>+	//AuDbgFile(new_xino);
>+	dput(parent);
>+	err = PTR_ERR(new_xino);
>+	if (IS_ERR(new_xino))
>+		goto out;
>+	err = 0;
>+	fput(br->br_xino);
>+	br->br_xino = new_xino;
>+
>+	h_sb = br->br_mnt->mnt_sb;
>+	for (bi = 0; bi <= bend; bi++) {
>+		if (unlikely(bi == bindex))
>+			continue;
>+		br = au_sbr(sb, bi);
>+		if (br->br_mnt->mnt_sb != h_sb)
>+			continue;
>+
>+		fput(br->br_xino);
>+		br->br_xino = new_xino;
>+		get_file(new_xino);
>+	}
>+
>+ out:
>+	AuTraceErr(err);
>+	//au_debug_off();
>+	return err;
>+}
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/*
>+ * create a xinofile at the default place/path.
>+ */
>+struct file *au_xino_def(struct super_block *sb)
>+{
>+	struct file *file;
>+	aufs_bindex_t bend, bindex, bwr;
>+	char *page, *p;
>+	struct path path;
>+
>+	AuTraceEnter();
>+
>+	bend = au_sbend(sb);
>+	bwr = -1;
>+	for (bindex = 0; bindex <= bend; bindex++)
>+		if (au_br_writable(au_sbr_perm(sb, bindex))
>+		    && !au_test_nfs(au_h_dptr(sb->s_root, bindex)->d_sb)) {
>+			bwr = bindex;
>+			break;
>+		}
>+
>+	if (bwr >= 0) {
>+		file = ERR_PTR(-ENOMEM);
>+		page = __getname();
>+		//if (LktrCond) {__putname(page); page = NULL;}
>+		if (unlikely(!page))
>+			goto out;
>+		path.mnt = au_sbr_mnt(sb, bwr);
>+		path.dentry = au_h_dptr(sb->s_root, bwr);
>+		p = d_path(&path, page, PATH_MAX - sizeof(AUFS_XINO_FNAME));
>+		//if (LktrCond) p = ERR_PTR(-1);
>+		file = (void *)p;
>+		if (p && !IS_ERR(p)) {
>+			strcat(p, "/" AUFS_XINO_FNAME);
>+			LKTRTrace("%s\n", p);
>+			file = au_xino_create(sb, p, /*silent*/0, sb->s_root);
>+			//if (LktrCond) {fput(file); file = ERR_PTR(-1);}
>+		}
>+		__putname(page);
>+	} else {
>+		file = au_xino_create(sb, AUFS_XINO_DEFPATH, /*silent*/0,
>+				      /*parent*/NULL);
>+		//if (LktrCond) {fput(file); file = ERR_PTR(-1);}
>+		if (unlikely(au_test_nfs(file->f_dentry->d_sb))) {
>+			AuErr("xino or noxino option is required "
>+			      "since %s is NFS\n", AUFS_XINO_DEFPATH);
>+			fput(file);
>+			file = ERR_PTR(-EINVAL);
>+		}
>+	}
>+
>+ out:
>+	AuTraceErrPtr(file);
>+	return file;
>+}
>diff -urN linux-2.6.25.4-unionfs.orig/fs/file_table.c linux-2.6.25.4-unionfs/fs/file_table.c
>--- linux-2.6.25.4-unionfs.orig/fs/file_table.c	2008-04-18 01:20:10 +0300
>+++ linux-2.6.25.4-unionfs/fs/file_table.c	2008-05-25 11:56:08 +0300
>@@ -308,6 +308,7 @@
> 		file_free(file);
> 	}
> }
>+EXPORT_SYMBOL(put_filp);
> 
> void file_move(struct file *file, struct list_head *list)
> {
>diff -urN linux-2.6.25.4-unionfs.orig/fs/Kconfig linux-2.6.25.4-unionfs/fs/Kconfig
>--- linux-2.6.25.4-unionfs.orig/fs/Kconfig	2008-05-25 11:53:37 +0300
>+++ linux-2.6.25.4-unionfs/fs/Kconfig	2008-05-25 11:56:08 +0300
>@@ -614,6 +614,8 @@
> 	  If you want to develop a userspace FS, or if you want to use
> 	  a filesystem based on FUSE, answer Y or M.
> 
>+source "fs/aufs/Kconfig"
>+
> config GENERIC_ACL
> 	bool
> 	select FS_POSIX_ACL
>diff -urN linux-2.6.25.4-unionfs.orig/fs/Makefile linux-2.6.25.4-unionfs/fs/Makefile
>--- linux-2.6.25.4-unionfs.orig/fs/Makefile	2008-05-25 11:53:37 +0300
>+++ linux-2.6.25.4-unionfs/fs/Makefile	2008-05-25 11:56:08 +0300
>@@ -107,6 +107,7 @@
> obj-$(CONFIG_AUTOFS4_FS)	+= autofs4/
> obj-$(CONFIG_ADFS_FS)		+= adfs/
> obj-$(CONFIG_FUSE_FS)		+= fuse/
>+obj-$(CONFIG_AUFS)		+= aufs/
> obj-$(CONFIG_UDF_FS)		+= udf/
> obj-$(CONFIG_SUN_OPENPROMFS)	+= openpromfs/
> obj-$(CONFIG_JFS_FS)		+= jfs/
>diff -urN linux-2.6.25.4-unionfs.orig/fs/namei.c linux-2.6.25.4-unionfs/fs/namei.c
>--- linux-2.6.25.4-unionfs.orig/fs/namei.c	2008-05-25 11:53:37 +0300
>+++ linux-2.6.25.4-unionfs/fs/namei.c	2008-05-25 11:56:08 +0300
>@@ -1292,7 +1292,7 @@
> 	return err;
> }
> 
>-static struct dentry *__lookup_hash(struct qstr *name,
>+struct dentry *__lookup_hash(struct qstr *name,
> 		struct dentry *base, struct nameidata *nd)
> {
> 	struct dentry *dentry;
>@@ -2837,3 +2837,5 @@
> EXPORT_SYMBOL(vfs_unlink);
> EXPORT_SYMBOL(dentry_unhash);
> EXPORT_SYMBOL(generic_readlink);
>+EXPORT_SYMBOL(__lookup_hash);
>+EXPORT_SYMBOL(deny_write_access);
>diff -urN linux-2.6.25.4-unionfs.orig/fs/splice.c linux-2.6.25.4-unionfs/fs/splice.c
>--- linux-2.6.25.4-unionfs.orig/fs/splice.c	2008-05-25 11:53:37 +0300
>+++ linux-2.6.25.4-unionfs/fs/splice.c	2008-05-25 11:56:08 +0300
>@@ -874,7 +874,6 @@
> {
> 	return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage);
> }
>-
> EXPORT_SYMBOL(generic_splice_sendpage);
> 
> /*
>diff -urN linux-2.6.25.4-unionfs.orig/fs/super.c linux-2.6.25.4-unionfs/fs/super.c
>--- linux-2.6.25.4-unionfs.orig/fs/super.c	2008-04-18 01:20:10 +0300
>+++ linux-2.6.25.4-unionfs/fs/super.c	2008-05-25 11:56:08 +0300
>@@ -267,6 +267,7 @@
> 	__fsync_super(sb);
> 	return sync_blockdev(sb->s_bdev);
> }
>+EXPORT_SYMBOL(fsync_super);
> 
> /**
>  *	generic_shutdown_super	-	common helper for ->kill_sb()
>diff -urN linux-2.6.25.4-unionfs.orig/include/linux/aufs_type.h linux-2.6.25.4-unionfs/include/linux/aufs_type.h
>--- linux-2.6.25.4-unionfs.orig/include/linux/aufs_type.h	1970-01-01 03:00:00 +0300
>+++ linux-2.6.25.4-unionfs/include/linux/aufs_type.h	2008-05-25 11:56:08 +0300
>@@ -0,0 +1,111 @@
>+/*
>+ * Copyright (C) 2005, 2006, 2007, 2008 Junjiro Okajima
>+ *
>+ * This program, aufs is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 2 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, write to the Free Software
>+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>+ */
>+
>+/* $Id: aufs_type.h,v 1.105 2008/05/04 23:55:14 sfjro Exp $ */
>+
>+#include <linux/ioctl.h>
>+
>+#ifndef __AUFS_TYPE_H__
>+#define __AUFS_TYPE_H__
>+
>+#define AUFS_VERSION	"20080505"
>+
>+/* move this to linux-2.6.19/include/magic.h */
>+#define AUFS_SUPER_MAGIC	('a' << 24 | 'u' << 16 | 'f' << 8 | 's')
>+
>+/* ---------------------------------------------------------------------- */
>+
>+#ifdef CONFIG_AUFS_BRANCH_MAX_127
>+/* some environments treat 'char' as 'unsigned char' by default */
>+typedef signed char aufs_bindex_t;
>+#define AUFS_BRANCH_MAX 127
>+#else
>+typedef short aufs_bindex_t;
>+#ifdef CONFIG_AUFS_BRANCH_MAX_511
>+#define AUFS_BRANCH_MAX 511
>+#elif defined(CONFIG_AUFS_BRANCH_MAX_1023)
>+#define AUFS_BRANCH_MAX 1023
>+#elif defined(CONFIG_AUFS_BRANCH_MAX_32767)
>+#define AUFS_BRANCH_MAX 32767
>+#else
>+#error unknown CONFIG_AUFS_BRANCH_MAX value
>+#endif
>+#endif
>+
>+#define AUFS_NAME		"aufs"
>+#define AUFS_FSTYPE		AUFS_NAME
>+
>+#define AUFS_ROOT_INO		2
>+#define AUFS_FIRST_INO		11
>+
>+#define AUFS_WH_PFX		".wh."
>+#define AUFS_WH_PFX_LEN		((int)sizeof(AUFS_WH_PFX) - 1)
>+#define AUFS_XINO_FNAME		"." AUFS_NAME ".xino"
>+#define AUFS_XINO_DEFPATH	"/tmp/" AUFS_XINO_FNAME
>+#define AUFS_XINO_TRUNC_INIT	64 /* blocks */
>+#define AUFS_XINO_TRUNC_STEP	4  /* blocks */
>+#define AUFS_DIRWH_DEF		3
>+#define AUFS_RDCACHE_DEF	10 /* seconds */
>+#define AUFS_WKQ_NAME		AUFS_NAME "d"
>+#define AUFS_NWKQ_DEF		4
>+#define AUFS_MFS_SECOND_DEF	30 /* seconds */
>+#define AUFS_PLINK_WARN		100 /* number of plinks */
>+
>+#ifdef CONFIG_AUFS_COMPAT
>+#define AUFS_DIROPQ_NAME	"__dir_opaque"
>+#else
>+#define AUFS_DIROPQ_NAME	AUFS_WH_PFX ".opq" /* whiteouted doubly */
>+#endif
>+#define AUFS_WH_DIROPQ		AUFS_WH_PFX AUFS_DIROPQ_NAME
>+
>+/* will be whiteouted doubly */
>+#define AUFS_WH_BASENAME	AUFS_WH_PFX AUFS_NAME
>+#define AUFS_WH_PLINKDIR	AUFS_WH_PFX "plink"
>+
>+/* ---------------------------------------------------------------------- */
>+
>+/* ioctl */
>+enum {
>+	AuCtlErr,
>+	AuCtlErr_Last
>+};
>+enum {
>+	AuCtl_REFRESH, //AuCtl_REFRESHV,
>+	//AuCtl_FLUSH_PLINK,
>+	//AuCtl_CPUP,
>+	AuCtl_CPDOWN, AuCtl_MVDOWN,
>+	//AuCtl_DIROPQ
>+};
>+
>+struct aufs_ctl_cp {
>+	int bsrc, bdst;
>+	int err;
>+};
>+
>+#define AuCtlType		'A'
>+#define AUFS_CTL_REFRESH	_IO(AuCtlType, AuCtl_REFRESH)
>+//#define AUFS_CTL_REFRESHV	_IO(AuCtlType, AuCtl_REFRESHV)
>+//#define AUFS_CTL_FLUSH_PLINK	_IOR(AuCtlType, AuCtl_FLUSH_PLINK)
>+//#define AUFS_CTL_CPUP		_IOWR(AuCtlType, AuCtl_CPUP, struct aufs_ctl_cp)
>+#define AUFS_CTL_CPDOWN \
>+	_IOWR(AuCtlType, AuCtl_CPDOWN, struct aufs_ctl_cp)
>+#define AUFS_CTL_MVDOWN \
>+	_IOWR(AuCtlType, AuCtl_MVDOWN, struct aufs_ctl_cp)
>+//#define AUFS_CTL_DIROPQ		_IO(AuCtlType, AuCtl_DIROPQ)
>+
>+#endif /* __AUFS_TYPE_H__ */
>diff -urN linux-2.6.25.4-unionfs.orig/include/linux/namei.h linux-2.6.25.4-unionfs/include/linux/namei.h
>--- linux-2.6.25.4-unionfs.orig/include/linux/namei.h	2008-04-18 01:20:17 +0300
>+++ linux-2.6.25.4-unionfs/include/linux/namei.h	2008-05-25 11:56:08 +0300
>@@ -71,6 +71,7 @@
> extern int path_lookup_open(int dfd, const char *name, unsigned lookup_flags, struct nameidata *, int open_flags);
> extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
> 		int (*open)(struct inode *, struct file *));
>+struct dentry * __lookup_hash(struct qstr *name, struct dentry * base, struct nameidata *nd);
> extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);
> extern void release_open_intent(struct nameidata *);
> 
>diff -urN linux-2.6.25.4-unionfs.orig/include/linux/splice.h linux-2.6.25.4-unionfs/include/linux/splice.h
>--- linux-2.6.25.4-unionfs.orig/include/linux/splice.h	2008-05-25 11:53:37 +0300
>+++ linux-2.6.25.4-unionfs/include/linux/splice.h	2008-05-25 11:56:08 +0300
>@@ -75,5 +75,4 @@
> extern long vfs_splice_to(struct file *in, loff_t *ppos,
> 			  struct pipe_inode_info *pipe, size_t len,
> 			  unsigned int flags);
>-
> #endif
>diff -urN linux-2.6.25.4-unionfs.orig/security/security.c linux-2.6.25.4-unionfs/security/security.c
>--- linux-2.6.25.4-unionfs.orig/security/security.c	2008-04-18 01:20:20 +0300
>+++ linux-2.6.25.4-unionfs/security/security.c	2008-05-25 11:56:08 +0300
>@@ -433,6 +433,7 @@
> 		return 0;
> 	return security_ops->inode_permission(inode, mask, nd);
> }
>+EXPORT_SYMBOL(security_inode_permission);
> 
> int security_inode_setattr(struct dentry *dentry, struct iattr *attr)
> {

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Attachments on bug 15838: 2654 | 2655