[Glusterfs] Fix delete share, Couldn't find the 'gluster_used_vols'

When we have multiple share driver backends, create a shared instance,
and the list of'self.gluster_used_vols' will only be updated on the
current node. If the RPC request to delete the share instance is sent
to other nodes,'self.gluster_used_vols' will be Cannot find the
information of the glusterfs volume we want to delete, so we need to
update'self.gluster_used_vols' when deleting the instance

Change-Id: I14835f6c54376737b41cbf78c94908ea1befde15
Closes-Bug: #1894362

manila/share/drivers/glusterfs/layout_volume.py

@@ -435,6 +435,10 @@ class GlusterfsVolumeMappedLayout(layout.GlusterfsShareLayoutBase):
                 gmgr.set_vol_option(USER_MANILA_SHARE, 'NONE')
                 gmgr.set_vol_option('nfs.disable', 'on')
 
+            # When deleting the share instance, we need to
+            # update'self.gluster_used_vols' again
+            self.gluster_used_vols = set()
+            self.gluster_used_vols.add(gmgr.qualified)
             self._push_gluster_vol(gmgr.qualified)
         except exception.GlusterfsException:
             msg = ("Error during delete_share request for "

manila/tests/share/drivers/glusterfs/test_layout_volume.py

@@ -587,6 +587,7 @@ class GlusterfsVolumeMappedLayoutTestCase(test.TestCase):
         gmgr1 = gmgr(self.glusterfs_target1, self._execute, None, None)
         gmgr1.set_vol_option = mock.Mock()
         gmgr1.get_vol_option = mock.Mock(return_value=clone_of)
+        new_vol_addr = self.glusterfs_target1
         self.mock_object(self._layout, '_glustermanager',
                          mock.Mock(return_value=gmgr1))
         self._layout.gluster_used_vols = set([self.glusterfs_target1])
@@ -596,6 +597,7 @@ class GlusterfsVolumeMappedLayoutTestCase(test.TestCase):
         gmgr1.get_vol_option.assert_called_once_with(
             'user.manila-cloned-from')
         self._layout._wipe_gluster_vol.assert_called_once_with(gmgr1)
+        self.assertIn(new_vol_addr, self._layout.gluster_used_vols)
         self._layout._push_gluster_vol.assert_called_once_with(
             self.glusterfs_target1)
         self._layout.private_storage.delete.assert_called_once_with(

releasenotes/notes/bug-1894362-fix-Glusterfs-del-share-3c8467e1d9f0c6e4.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Fixed `bug #1894362  <https://bugs.launchpad.net/manila/+bug/1894362>`_
+    Fixed the problem of Couldn't find the'gluster_used_vols' error when
+    deploying glusterfs driver multi-backend service and deleting share
+    instance.