Merge "Check for concurrent port binding deletion before binding the port"

neutron/plugins/ml2/plugin.py

@@ -51,6 +51,7 @@ from neutron.extensions import portbindings
 from neutron.extensions import providernet as provider
 from neutron import manager
 from neutron.openstack.common import excutils
+from neutron.openstack.common.gettextutils import _LI
 from neutron.openstack.common import importutils
 from neutron.openstack.common import jsonutils
 from neutron.openstack.common import lockutils
@@ -948,6 +949,11 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
             cur_binding = db.get_dvr_port_binding_by_host(session,
                                                           port_id,
                                                           host)
+            if not cur_binding:
+                LOG.info(_LI("Binding info for port %s was not found, "
+                             "it might have been deleted already."),
+                         port_id)
+                return
             # Commit our binding results only if port has not been
             # successfully bound concurrently by another thread or
             # process and no binding inputs have been changed.
@@ -1055,6 +1061,8 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
                            filter(models_v2.Port.id.startswith(port_id)).
                            one())
             except sa_exc.NoResultFound:
+                LOG.debug("No ports have port_id starting with %s",
+                          port_id)
                 return
             except exc.MultipleResultsFound:
                 LOG.error(_("Multiple ports have port_id starting with %s"),
@@ -1072,8 +1080,18 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
                 port_context = driver_context.DvrPortContext(
                     self, plugin_context, port, network, binding)
             else:
+                # since eager loads are disabled in port_db query
+                # related attribute port_binding could disappear in
+                # concurrent port deletion.
+                # It's not an error condition.
+                binding = port_db.port_binding
+                if not binding:
+                    LOG.info(_LI("Binding info for port %s was not found, "
+                                 "it might have been deleted already."),
+                             port_id)
+                    return
                 port_context = driver_context.PortContext(
-                    self, plugin_context, port, network, port_db.port_binding)
+                    self, plugin_context, port, network, binding)
 
         return self._bind_port_if_needed(port_context)
 

neutron/tests/unit/ml2/test_port_binding.py

@@ -19,6 +19,7 @@ from neutron import context
 from neutron.extensions import portbindings
 from neutron import manager
 from neutron.plugins.ml2 import config as config
+from neutron.plugins.ml2 import models as ml2_models
 from neutron.tests.unit import test_db_plugin as test_plugin
 
 
@@ -98,6 +99,29 @@ class PortBindingTestCase(test_plugin.NeutronDbPluginV2TestCase):
                                 portbindings.VIF_TYPE_OVS,
                                 True, True, 'ACTIVE')
 
+    def test_update_port_binding_no_binding(self):
+        ctx = context.get_admin_context()
+        with self.port(name='name') as port:
+            # emulating concurrent binding deletion
+            (ctx.session.query(ml2_models.PortBinding).
+             filter_by(port_id=port['port']['id']).delete())
+            self.assertIsNone(
+                self.plugin.get_bound_port_context(ctx, port['port']['id']))
+
+    def test_commit_dvr_port_binding(self):
+        ctx = context.get_admin_context()
+
+        class MechContext(object):
+            pass
+
+        mctx = MechContext()
+        mctx._binding = None
+        # making a shortcut: calling private method directly to
+        # avoid bothering with "concurrent" port binding deletion
+        res = self.plugin._commit_dvr_port_binding(ctx, 'anyUUID',
+                                                   'HostA', mctx)
+        self.assertIsNone(res)
+
     def _test_update_port_binding(self, host, new_host=None):
         with mock.patch.object(self.plugin,
                                '_notify_port_updated') as notify_mock: