Set backup status to error on VolumeNotFound

When creating a backup and it fails we will try
to update the status on the volume but if it does
not exist we will instead fail on that and the
backup will be stuck in creating status which means
cloud admin need to help resetting the status.

This catches the VolumeNotFound exception and ignores
updating the volume status and thus backup will be
set to error and can be deleted by user instead.

Closes-Bug: #1996049
Change-Id: Iafa92ece7f83323af257c1702df5029469b11739

cinder/backup/manager.py

@@ -416,10 +416,15 @@ class BackupManager(manager.SchedulerDependentManager):
                     snapshot.status = fields.SnapshotStatus.AVAILABLE
                     snapshot.save()
                 else:
-                    self.db.volume_update(
-                        context, volume_id,
-                        {'status': previous_status,
-                         'previous_status': 'error_backing-up'})
+                    try:
+                        self.db.volume_update(
+                            context, volume_id,
+                            {'status': previous_status,
+                             'previous_status': 'error_backing-up'})
+                    except exception.VolumeNotFound:
+                        # If the volume was deleted we cannot update its
+                        # status but we still want to set the backup to error.
+                        pass
                 volume_utils.update_backup_error(backup, str(err))
 
     def _start_backup(self, context, backup, volume):

cinder/tests/unit/backup/test_backup.py

@@ -673,6 +673,26 @@ class BackupTestCase(BaseBackupTest):
             backup.refresh()
         self.assertEqual(fields.BackupStatus.DELETED, backup.status)
 
+    @mock.patch('cinder.backup.manager.BackupManager._start_backup',
+                side_effect=FakeBackupException(str(uuid.uuid4())))
+    @mock.patch.object(db, 'volume_update')
+    def test_create_backup_aborted_volume_not_found(self, vol_up_mock,
+                                                    start_backup_mock):
+        """Test error handling when backup fails and volume does not exist."""
+        vol_id = self._create_volume_db_entry(size=1)
+        backup = self._create_backup_db_entry(volume_id=vol_id)
+
+        vol_up_mock.side_effect = exception.VolumeNotFound(volume_id=vol_id)
+
+        self.assertRaises(FakeBackupException,
+                          self.backup_mgr.create_backup,
+                          self.ctxt,
+                          backup)
+        backup.refresh()
+        self.assertEqual(fields.BackupStatus.ERROR, backup.status)
+        self.assertTrue(start_backup_mock.called)
+        self.assertTrue(vol_up_mock.called)
+
     @mock.patch('cinder.backup.manager.BackupManager._start_backup',
                 side_effect=FakeBackupException(str(uuid.uuid4())))
     def test_create_backup_with_snapshot_error(self, mock_start_backup):

releasenotes/notes/backup-volumenotfound-set-to-error-fa47b3631093a702.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    `Bug #1996049 <https://bugs.launchpad.net/cinder/+bug/1996049>`_: Fixed bug
+    where backup was not set to error on failure when volume did not exist.