Race between list_networks and delete_network in OVS plugin

[Eugene Nikanorov]

When listing networks, OVS plugin fetches networks bindings via additional per-network db-query.

In case some network (and its binding) from the list is getting deleted in the process of extending networks dict, _extend_network_dict_provider throws an exception:

TRACE neutron.api.v2.resource Traceback (most recent call last):
TRACE neutron.api.v2.resource File "/opt/stack/neutron/neutron/api/v2/resource.py", line 84, in resource
TRACE neutron.api.v2.resource result = method(request=request, **args)
TRACE neutron.api.v2.resource File "/opt/stack/neutron/neutron/api/v2/base.py", line 279, in index
TRACE neutron.api.v2.resource return self._items(request, True, parent_id)
TRACE neutron.api.v2.resource File "/opt/stack/neutron/neutron/api/v2/base.py", line 233, in _items
TRACE neutron.api.v2.resource obj_list = obj_getter(request.context, **kwargs)
TRACE neutron.api.v2.resource File "/opt/stack/neutron/neutron/plugins/openvswitch/ovs_neutron_plugin.py", line 567, in get_networks
TRACE neutron.api.v2.resource self._extend_network_dict_provider(context, net)
TRACE neutron.api.v2.resource File "/opt/stack/neutron/neutron/plugins/openvswitch/ovs_neutron_plugin.py", line 381, in _extend_network_dict_provider
TRACE neutron.api.v2.resource network[provider.NETWORK_TYPE] = binding.network_type
TRACE neutron.api.v2.resource AttributeError: 'NoneType' object has no attribute 'network_type'

This issue is reproducible easily with tempest.api.network.test_networks.BulkNetworkOps

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/63918
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=126a26367b40125b3e434c948f21a4980bc86340
Submitter: Jenkins
Branch: master

commit 126a26367b40125b3e434c948f21a4980bc86340
Author: Eugene Nikanorov <email address hidden>
Date: Tue Dec 24 15:08:22 2013 +0400

    Fix race in get_network(s) in OVS plugin

    Load network bindings eagerly with networks.
    Otherwise a different db query could try to fetch network bindings
    for already deleted networks. The issue is reproducible with
    concurrent tempest network API tests.

    Closes-Bug: 1263686
    Change-Id: I0521ab162220c66a62491ff8e7e4a9f6d7bef6c4