From 1e176b563e9d97473fb6d18aa8129ef55292c8a7 Mon Sep 17 00:00:00 2001 From: Attila Fazekas Date: Sun, 4 May 2014 19:54:37 +0200 Subject: [PATCH] L3 RPC loop could delete a router on concurrent update routers_updated does not acquire any lock just updates a set for future rpc loop processing. The self.updated_routers can be changed by concurrent update notification. If this change happens at the time around the self.plugin_rpc.get_routers call, the additional routers - by mistake - is considered as admin_state_up=false routers, which are safe to delete. Creating a local copy of the updated_routers and preserve the fresh updated_routers entries for the next _rpc_loop operations. Change-Id: Icc7377f9c29e248c3b34562465e859b15ecc2ec3 Closes-Bug: #1315467 Partial-Bug: #1253896 --- neutron/agent/l3_agent.py | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/neutron/agent/l3_agent.py b/neutron/agent/l3_agent.py index 8adf9b5919..aa185e4306 100644 --- a/neutron/agent/l3_agent.py +++ b/neutron/agent/l3_agent.py @@ -793,18 +793,24 @@ class L3NATAgent(firewall_l3_agent.FWaaSL3AgentRpcCallback, manager.Manager): # _rpc_loop and _sync_routers_task will not be # executed in the same time because of lock. # so we can clear the value of updated_routers - # and removed_routers + # and removed_routers, but they can be updated by + # updated_routers and removed_routers rpc call try: LOG.debug(_("Starting RPC loop for %d updated routers"), len(self.updated_routers)) if self.updated_routers: - router_ids = list(self.updated_routers) + # We're capturing and clearing the list, and will + # process the "captured" updates in this loop, + # and any updates that happen due to a context switch + # will be picked up on the next pass. + updated_routers = set(self.updated_routers) + self.updated_routers.clear() + router_ids = list(updated_routers) routers = self.plugin_rpc.get_routers( self.context, router_ids) - + # routers with admin_state_up=false will not be in the fetched fetched = set([r['id'] for r in routers]) - self.removed_routers.update(self.updated_routers - fetched) - self.updated_routers.clear() + self.removed_routers.update(updated_routers - fetched) self._process_routers(routers) self._process_router_delete()