Ceph: Fix delete backup with non-existent pool

If a non-existent pool is specified, Ceph will raise
ObjectNotFound error when deleting a backup.

Cinder should catch this error and delete the db
record directly.

Change-Id: I41177b9b1f63c6bd2296a5eff70f0058ce3393e5
Closes-bug: #1686897

cinder/backup/drivers/ceph.py

@@ -1202,6 +1202,7 @@ class CephBackupDriver(driver.BackupDriver):
         LOG.debug('Delete started for backup=%s', backup.id)
 
         delete_failed = False
+        has_pool = True
         try:
             self._try_delete_base_image(backup)
         except self.rbd.ImageNotFound:
@@ -1210,7 +1211,13 @@ class CephBackupDriver(driver.BackupDriver):
                 "not found. Deleting backup metadata.",
                 {'backup': backup.id, 'volume': backup.volume_id})
             delete_failed = True
+        except self.rados.ObjectNotFound:
+            LOG.warning("The pool %(pool)s doesn't exist.",
+                        {'pool': backup.container})
+            delete_failed = True
+            has_pool = False
 
+        if has_pool:
             with rbd_driver.RADOSClient(self, backup.container) as client:
                 VolumeMetadataBackup(client, backup.id).remove_if_exists()
 

cinder/tests/unit/backup/drivers/test_backup_ceph.py

@@ -91,6 +91,7 @@ def common_mocks(f):
             inst.mock_rbd = mock_rbd
             inst.mock_rbd.ImageBusy = MockImageBusyException
             inst.mock_rbd.ImageNotFound = MockImageNotFoundException
+            inst.mock_rados.ObjectNotFound = MockObjectNotFoundException
 
             inst.service.rbd = inst.mock_rbd
             inst.service.rados = inst.mock_rados
@@ -828,6 +829,20 @@ class BackupCephTestCase(test.TestCase):
             self.service.delete(self.backup)
             self.assertEqual([MockImageNotFoundException], RAISED_EXCEPTIONS)
 
+    @common_mocks
+    @mock.patch('cinder.backup.drivers.ceph.VolumeMetadataBackup', spec=True)
+    def test_delete_pool_not_found(self, mock_meta_backup):
+        with mock.patch.object(
+                self.service, '_try_delete_base_image') as mock_del_base:
+            mock_del_base.side_effect = self.mock_rados.ObjectNotFound
+            # ObjectNotFound exception is caught so that db entry can be
+            # cleared
+            self.service.delete(self.backup)
+            self.assertEqual([MockObjectNotFoundException],
+                             RAISED_EXCEPTIONS)
+            mock_del_base.assert_called_once_with(self.backup)
+            mock_meta_backup.return_value.remove_if_exists.assert_not_called()
+
     @common_mocks
     def test_diff_restore_allowed_with_image_not_exists(self):
         """Test diff restore not allowed when backup not diff-format."""