Merge "Do not delete trunk bridges if service port attached"

neutron/services/trunk/drivers/openvswitch/agent/ovsdb_handler.py

@@ -205,6 +205,20 @@ class OVSDBHandler(object):
         :param bridge_name: Name of the bridge used for locking purposes.
         :param port: Parent port dict.
         """
+        # TODO(njohnston): In the case of DPDK with trunk ports, if nova
+        # deletes an interface and then re-adds it we can get a race
+        # condition where the port is re-added and then the bridge is
+        # deleted because we did not properly catch the re-addition.  To
+        # solve this would require transitioning to ordered event
+        # resolution, like the L3 agent does with the
+        # ResourceProcessingQueue class.  Until we can make that happen, we
+        # try to mitigate the issue by checking if there is a port on the
+        # bridge and if so then do not remove it.
+        bridge = ovs_lib.OVSBridge(bridge_name)
+        if bridge_has_instance_port(bridge):
+            LOG.debug("The bridge %s has instances attached so it will not "
+                      "be deleted.", bridge_name)
+            return
         try:
             # TODO(jlibosva): Investigate how to proceed during removal of
             # trunk bridge that doesn't have metadata stored.

neutron/tests/functional/services/trunk/drivers/openvswitch/agent/test_ovsdb_handler.py

@@ -193,3 +193,11 @@ class OVSDBHandlerTestCase(base.OVSAgentTestFramework):
             # Check no resources are left behind.
             self.assertFalse(self.trunk_br.exists())
             self.assertFalse(ovsdb_handler.bridge_has_service_port(br_int))
+
+    def test_do_not_delete_trunk_bridge_with_instance_ports(self):
+        ports = self._fill_trunk_dict()
+        self.setup_agent_and_ports(port_dicts=ports)
+        self.wait_until_ports_state(self.ports, up=True)
+        self.ovsdb_handler.handle_trunk_remove(self.trunk_br.br_name,
+                ports.pop())
+        self.assertTrue(self.trunk_br.exists())

neutron/tests/unit/services/trunk/drivers/openvswitch/agent/test_ovsdb_handler.py

@@ -182,7 +182,9 @@ class TestOVSDBHandler(base.BaseTestCase):
     def test_handle_trunk_remove_trunk_manager_failure(self):
         with mock.patch.object(self.ovsdb_handler, '_get_trunk_metadata',
                 side_effect=trunk_manager.TrunkManagerError(error='error')):
-            self.ovsdb_handler.handle_trunk_remove('foo', self.fake_port)
+            with mock.patch.object(ovsdb_handler, 'bridge_has_instance_port',
+                    return_value=True):
+                self.ovsdb_handler.handle_trunk_remove('foo', self.fake_port)
 
     @mock.patch('neutron.agent.common.ovs_lib.OVSBridge')
     def test_handle_trunk_remove_rpc_failure(self, br):