Soft delete tmp migration volume

Previously the row for the temporary migration volume was deleted from
the database, which caused a foreign key violation for its admin
metadata. Regardless, the volume should have been soft deleted from the
database anyway, and this patch takes care of that.

Change-Id: I8e4942b0e21ec79c90aa95b18b5612b5b133fd62
Closes-Bug: #1219097

cinder/db/sqlalchemy/api.py

@@ -1119,9 +1119,6 @@ def finish_volume_migration(context, src_vol_id, dest_vol_id):
         session.query(models.Volume).\
             filter_by(id=src_vol_id).\
             update(updates)
-        session.query(models.Volume).\
-            filter_by(id=dest_vol_id).\
-            delete()
 
 
 @require_admin_context

cinder/tests/db/test_finish_migration.py

@@ -44,8 +44,6 @@ def test_finish_volume_migration(self):
         db.finish_volume_migration(ctxt, src_volume['id'],
                                    dest_volume['id'])
 
-        self.assertRaises(exception.VolumeNotFound, db.volume_get, ctxt,
-                          dest_volume['id'])
         src_volume = db.volume_get(ctxt, src_volume['id'])
         expected_name = 'volume-%s' % dest_volume['id']
         self.assertEqual(src_volume['_name_id'], dest_volume['id'])

cinder/volume/manager.py

@@ -705,6 +705,7 @@ def migrate_volume_completion(self, ctxt, volume_id, new_volume_id,
             LOG.error(msg % {'vol': volume_id, 'err': ex})
 
         self.db.finish_volume_migration(ctxt, volume_id, new_volume_id)
+        self.db.volume_destroy(ctxt, new_volume_id)
         self.db.volume_update(ctxt, volume_id, {'migration_status': None})
         return volume['id']