--- /usr/lib/python2.7/site-packages/nova/virt/disk/api.py.old	2018-05-07 17:29:29.310129011 +0300
+++ /usr/lib/python2.7/site-packages/nova/virt/disk/api.py	2018-05-04 15:51:49.431347099 +0300
@@ -137,14 +137,14 @@
                       run_as_root=run_as_root)
 
 
-def get_disk_size(path):
+def get_disk_size(path, force_share=False):
     """Get the (virtual) size of a disk image
 
     :param path: Path to the disk image
     :returns: Size (in bytes) of the given disk image as it would be seen
               by a virtual machine.
     """
-    return images.qemu_img_info(path).virtual_size
+    return images.qemu_img_info(path, force_share=force_share).virtual_size
 
 
 def extend(image, size):
--- /usr/lib/python2.7/site-packages/nova/virt/images.py.old	2018-05-07 17:30:57.721863823 +0300
+++ /usr/lib/python2.7/site-packages/nova/virt/images.py	2018-05-04 15:52:06.985264486 +0300
@@ -43,7 +43,7 @@
     address_space=1 * units.Gi)
 
 
-def qemu_img_info(path, format=None):
+def qemu_img_info(path, format=None, force_share=False):
     """Return an object containing the parsed output from qemu-img info."""
     # TODO(mikal): this code should not be referring to a libvirt specific
     # flag.
@@ -56,6 +56,8 @@
 
     try:
         cmd = ('env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path)
+        if force_share:
+            cmd = cmd + ('--force-share',)
         if format is not None:
             cmd = cmd + ('-f', format)
         out, err = utils.execute(*cmd, prlimit=QEMU_IMG_LIMITS)
--- /usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py.old	2018-05-07 17:31:29.771822315 +0300
+++ /usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py	2018-05-04 15:51:02.773542630 +0300
@@ -403,6 +403,7 @@
 # for all architectures/hypervisors, as this value rises to
 # meet them.
 MIN_LIBVIRT_VERSION = (0, 10, 2)
+MIN_QEMU_VERSION = (2, 1, 0)
 # TODO(berrange): Re-evaluate this at start of each release cycle
 # to decide if we want to plan a future min version bump.
 # MIN_LIBVIRT_VERSION can be updated to match this after
@@ -482,6 +483,11 @@
 # libvirt 1.3 fix f391889f4e942e22b9ef8ecca492de05106ce41e
 MIN_LIBVIRT_PF_WITH_NO_VFS_CAP_VERSION = (1, 3, 0)
 
+# qemu >= 2.10.0
+# Use '--force-share' to skip image locking during qemu-img info
+# execution as running qemu process owns the write lock.
+MIN_QEMU_FORCE_SHARE = (2, 10, 0)
+
 # ppc64/ppc64le architectures with KVM
 # NOTE(rfolco): Same levels for Libvirt/Qemu on Big Endian and Little
 # Endian giving the nuance around guest vs host architectures
@@ -580,6 +586,9 @@
         self._remotefs = remotefs.RemoteFilesystem()
 
         self._live_migration_flags = self._block_migration_flags = None
+        
+        # Assume pre 2.10 version of qemu is in use
+        self._force_share = False
 
     def _get_volume_drivers(self):
         return libvirt_volume_drivers
@@ -664,6 +673,16 @@
                 _('Nova requires libvirt version %s or greater.') %
                 self._version_to_string(MIN_LIBVIRT_VERSION))
 
+        if CONF.libvirt.virt_type in ("qemu", "kvm"):
+            if self._host.has_min_version(hv_ver=MIN_QEMU_VERSION):
+                self._force_share = (
+                    self._host.has_min_version(hv_ver=MIN_QEMU_FORCE_SHARE)
+                )
+            else:
+                raise exception.InternalError(
+                    _('Nova requires QEMU version %s or greater.') %
+                    self._version_to_string(MIN_QEMU_VERSION))
+
         if (CONF.libvirt.virt_type == 'parallels' and
             not self._host.has_min_version(MIN_LIBVIRT_PARALLELS_VERSION)):
             raise exception.NovaException(
@@ -1858,14 +1877,23 @@
         #             in QEMU 1.3. In order to do this, we need to create
         #             a destination image with the original backing file
         #             and matching size of the instance root disk.
-        src_disk_size = libvirt_utils.get_disk_size(disk_path,
-                                                    format=source_format)
-        src_back_path = libvirt_utils.get_disk_backing_file(disk_path,
-                                                        format=source_format,
-                                                        basename=False)
+        src_disk_size = libvirt_utils.get_disk_size(
+            disk_path,
+            format=source_format,
+            force_share=self._force_share
+        )
+        src_back_path = libvirt_utils.get_disk_backing_file(
+            disk_path,
+            format=source_format,
+            basename=False,
+            force_share=self._force_share
+        )
         disk_delta = out_path + '.delta'
-        libvirt_utils.create_cow_image(src_back_path, disk_delta,
-                                       src_disk_size)
+        libvirt_utils.create_cow_image(
+            src_back_path, disk_delta,
+            src_disk_size,
+            force_share=self._force_share
+        )
 
         quiesced = False
         try:
@@ -6996,8 +7024,14 @@
 
             disk_type = driver_nodes[cnt].get('type')
             if disk_type == "qcow2":
-                backing_file = libvirt_utils.get_disk_backing_file(path)
-                virt_size = disk.get_disk_size(path)
+                backing_file = libvirt_utils.get_disk_backing_file(
+                    path,
+                    force_share=self._force_share
+                )
+                virt_size = disk.get_disk_size(
+                    path,
+                    force_share=self._force_share
+                )
                 over_commit_size = int(virt_size) - dk_size
             else:
                 backing_file = ""
--- /usr/lib/python2.7/site-packages/nova/virt/libvirt/utils.py.old	2018-05-07 17:31:55.222746021 +0300
+++ /usr/lib/python2.7/site-packages/nova/virt/libvirt/utils.py	2018-05-04 15:52:35.339131046 +0300
@@ -75,7 +75,7 @@
     execute('qemu-img', 'create', '-f', disk_format, path, size)
 
 
-def create_cow_image(backing_file, path, size=None):
+def create_cow_image(backing_file, path, size=None, force_share=False):
     """Create COW image
 
     Creates a COW image with the given backing file
@@ -87,7 +87,8 @@
     cow_opts = []
     if backing_file:
         cow_opts += ['backing_file=%s' % backing_file]
-        base_details = images.qemu_img_info(backing_file)
+        base_details = images.qemu_img_info(backing_file,
+                                            force_share=force_share)
     else:
         base_details = None
     # Explicitly inherit the value of 'cluster_size' property of a qcow2
@@ -163,25 +164,27 @@
         return None
 
 
-def get_disk_size(path, format=None):
+def get_disk_size(path, format=None, force_share=False):
     """Get the (virtual) size of a disk image
 
     :param path: Path to the disk image
     :param format: the on-disk format of path
+    :param force_share: Inhibit write lock during qemu-img info call
     :returns: Size (in bytes) of the given disk image as it would be seen
               by a virtual machine.
     """
-    size = images.qemu_img_info(path, format).virtual_size
+    size = images.qemu_img_info(path, format, force_share).virtual_size
     return int(size)
 
 
-def get_disk_backing_file(path, basename=True, format=None):
+def get_disk_backing_file(path, basename=True, format=None, force_share=False):
     """Get the backing file of a disk image
 
     :param path: Path to the disk image
+    :param force_share: Inhibit write lock during qemu-img info cal
     :returns: a path to the image's backing store
     """
-    backing_file = images.qemu_img_info(path, format).backing_file
+    backing_file = images.qemu_img_info(path, format, force_share).backing_file
     if backing_file and basename:
         backing_file = os.path.basename(backing_file)