From b197f7c1c4b9c0dd4c58f5c5a4b654dde5596b85 Mon Sep 17 00:00:00 2001
From: Adrian Chiris <adrianc@mellanox.com>
Date: Thu, 31 Jan 2019 18:51:33 +0200
Subject: [PATCH] Delete port binding level for deleted bindings

Today, if live migration has failed after an inactive
binding was created on the destination node but before
the activation of the created binding, the port's binding level
for the destination host is not cleared during nova's API call
to neutron to delete the port binding.

This causes future attempts to perform live migration
of the instance to the same host to fail.

This change removes port binding level object during port binding
deletion.

Closes-Bug: #1815345

Change-Id: Idd55f7d24a2062c08ac8a0dc2243625632d962a5
---
 neutron/plugins/ml2/plugin.py                 |  6 +++++-
 neutron/tests/unit/plugins/ml2/test_plugin.py | 17 +++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/neutron/plugins/ml2/plugin.py b/neutron/plugins/ml2/plugin.py
index e9cda8b6612..08fd82cb87c 100644
--- a/neutron/plugins/ml2/plugin.py
+++ b/neutron/plugins/ml2/plugin.py
@@ -2274,5 +2274,9 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
     @utils.transaction_guard
     @db_api.retry_if_session_inactive()
     def delete_port_binding(self, context, host, port_id):
-        ports_obj.PortBinding.delete_objects(context, host=host,
+        ports_obj.PortBinding.delete_objects(context,
+                                             host=host,
                                              port_id=port_id)
+        db.clear_binding_levels(context,
+                                port_id=port_id,
+                                host=host)
diff --git a/neutron/tests/unit/plugins/ml2/test_plugin.py b/neutron/tests/unit/plugins/ml2/test_plugin.py
index 1bda8dfac7a..8a6b273c3c5 100644
--- a/neutron/tests/unit/plugins/ml2/test_plugin.py
+++ b/neutron/tests/unit/plugins/ml2/test_plugin.py
@@ -1663,6 +1663,23 @@ class TestMl2PluginOnly(Ml2PluginV2TestCase):
         self.assertEqual(port_id, ml2_plugin.Ml2Plugin._device_to_port_id(
             self.context, port_id))
 
+    @mock.patch.object(ml2_db, 'clear_binding_levels')
+    @mock.patch.object(port_obj.PortBinding, 'delete_objects')
+    def test_delete_port_binding_delete_binding_and_levels(
+            self,
+            clear_bl_mock,
+            delete_port_binding_mock):
+        port_id = uuidutils.generate_uuid()
+        host = 'fake-host'
+        plugin = directory.get_plugin()
+        plugin.delete_port_binding(self.context, host, port_id)
+        self.assertTrue(clear_bl_mock.called_with(self.context,
+                                                  port_id=port_id,
+                                                  host=host))
+        self.assertTrue(delete_port_binding_mock.called_with(self.context,
+                                                             host=host,
+                                                             port_id=port_id))
+
 
 class Test_GetNetworkMtu(Ml2PluginV2TestCase):