Creating snapshot on NFS backend fails

Fixed an issue with creating a snapshot on an NFS backend
if the snapshot name is not specified.

Closes-Bug: 1886222
Change-Id: I33da9c65ef56b3e4967170e3a0fb25f12e067876

cinder/tests/unit/volume/drivers/test_remotefs.py

@@ -314,7 +314,7 @@ class RemoteFsSnapDriverTestCase(test.TestCase):
                  mock.call(*command3, run_as_root=True)]
         self._driver._execute.assert_has_calls(calls)
 
-    def _test_create_snapshot(self, volume_in_use=False, tmp_snap=False,
+    def _test_create_snapshot(self, display_name=None, volume_in_use=False,
                               encryption=False):
         fake_snapshot_info = {}
         if encryption:
@@ -329,6 +329,7 @@ class RemoteFsSnapDriverTestCase(test.TestCase):
             snapshot = self._fake_snapshot
             snapshot_path = self._fake_snapshot_path
 
+        snapshot.display_name = display_name
         self._driver._local_path_volume_info = mock.Mock(
             return_value=mock.sentinel.fake_info_path)
         self._driver._read_info_file = mock.Mock(
@@ -347,18 +348,15 @@ class RemoteFsSnapDriverTestCase(test.TestCase):
             snapshot.id: fake_snapshot_file_name
         }
         exp_acceptable_states = ['available', 'in-use', 'backing-up']
-        if tmp_snap:
+        if display_name and display_name.startswith('tmp-snap-'):
             exp_acceptable_states.append('downloading')
             self._fake_snapshot.volume.status = 'downloading'
-            display_name = 'tmp-snap-%s' % self._fake_snapshot.id
-            self._fake_snapshot.display_name = display_name
 
         if volume_in_use:
             snapshot.volume.status = 'backing-up'
             snapshot.volume.attach_status = 'attached'
             expected_method_called = '_create_snapshot_online'
         else:
-            snapshot.volume.status = 'available'
             expected_method_called = '_do_create_snapshot'
 
         self._driver._create_snapshot(snapshot)
@@ -389,8 +387,9 @@ class RemoteFsSnapDriverTestCase(test.TestCase):
                           self._driver._create_snapshot,
                           self._fake_snapshot)
 
-    def test_create_snapshot_w_image_caching(self):
-        self._test_create_snapshot(tmp_snap=True)
+    @ddt.data(None, 'test', 'tmp-snap-404f-404')
+    def test_create_snapshot_names(self, display_name):
+        self._test_create_snapshot(display_name=display_name)
 
     @mock.patch('cinder.db.snapshot_get')
     @mock.patch('time.sleep')

cinder/volume/drivers/remotefs.py

@@ -1623,7 +1623,8 @@ class RemoteFSSnapDriverBase(RemoteFSDriver):
         status = snapshot.volume.status
 
         acceptable_states = ['available', 'in-use', 'backing-up']
-        if snapshot.display_name.startswith('tmp-snap-'):
+        if (snapshot.display_name and
+                snapshot.display_name.startswith('tmp-snap-')):
             # This is an internal volume snapshot. In order to support
             # image caching, we'll allow creating/deleting such snapshots
             # while having volumes in 'downloading' state.

releasenotes/notes/bug-1886222-nfs-snapshot-82b5519175c48a6f.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    `Bug #1886222 <https://bugs.launchpad.net/cinder/+bug/1886222>`_:
+    Fixed an issue with creating a snapshot on an NFS backend
+    if the snapshot name is not specified.