nova.patch

diff --git a/nova/storage/linuxscsi.py b/nova/storage/linuxscsi.py
index ed30462..bb7c265 100644
--- a/nova/storage/linuxscsi.py
+++ b/nova/storage/linuxscsi.py
@@ -150,3 +150,13 @@ def find_multipath_device(device):
                 "devices": devices}
         return info
     return None
+
+
+def flush_device_io(device):
+    """This is used to flush any remaining IO in the buffers."""
+    try:
+        LOG.debug("Flushing IO for device %s" % device)
+        utils.execute('blockdev', '--flushbufs', device,
+                      run_as_root=True)
+    except processutils.ProcessExecutionError:
+        LOG.warn(_LW("Failed to flush IO buffers on device %s"), device)
diff --git a/nova/virt/libvirt/volume.py b/nova/virt/libvirt/volume.py
index 8688458..4d34d60 100644
--- a/nova/virt/libvirt/volume.py
+++ b/nova/virt/libvirt/volume.py
@@ -558,6 +558,9 @@ class LibvirtISCSIVolumeDriver(LibvirtBaseVolumeDriver):
         if self.use_multipath and multipath_device:
             return self._disconnect_volume_multipath_iscsi(iscsi_properties,
                                                            multipath_device)
+        else:
+            # remove the volume from the system.
+            self._delete_device(host_device)
 
         # NOTE(vish): Only disconnect from the target if no luns from the
         #             target are in use.
@@ -571,14 +574,13 @@ class LibvirtISCSIVolumeDriver(LibvirtBaseVolumeDriver):
                                                         '/dev/disk/by-path/'))]
         if not devices:
             self._disconnect_from_iscsi_portal(iscsi_properties)
-        elif host_device not in devices:
-            # Delete device if LUN is not in use by another instance
-            self._delete_device(host_device)
 
     def _delete_device(self, device_path):
         device_name = os.path.basename(os.path.realpath(device_path))
         delete_control = '/sys/block/' + device_name + '/device/delete'
         if os.path.exists(delete_control):
+            # Better flush an IO prior to removing it from the system
+            linuxscsi.flush_device_io(device_path)
             # Copy '1' from stdin to the device delete control file
             utils.execute('cp', '/dev/stdin', delete_control,
                           process_input='1', run_as_root=True)