NSX: Fix possible deadlock in sync code

This patch removes the call to nsx from within the db transcation
which can cause deadlock if another request comes in during this time.

Change-Id: If16b53a77997bccfdff2554dead26f42e23eaec9
Closes-bug: #1278991

diff --git a/neutron/plugins/nicira/common/sync.py b/neutron/plugins/nicira/common/sync.py
index 6bddb1ea2663f68c1ede8b32657fb8e6c288b605..7b0fca7bd1fc1c4de43dc3673394797283fc03f2 100644 (file)
--- a/neutron/plugins/nicira/common/sync.py
+++ b/neutron/plugins/nicira/common/sync.py
@@ -297,17 +297,17 @@ class NvpSynchronizer():
             neutron_nvp_mappings[neutron_id] = (
                 neutron_nvp_mappings.get(neutron_id, []) +
                 [self._nvp_cache[ls_uuid]])
-        with ctx.session.begin(subtransactions=True):
-            # Fetch neutron networks from database
-            filters = {'router:external': [False]}
-            if not scan_missing:
-                filters['id'] = neutron_net_ids
-            # TODO(salv-orlando): Filter out external networks
-            for network in self._plugin._get_collection_query(
-                ctx, models_v2.Network, filters=filters):
-                lswitches = neutron_nvp_mappings.get(network['id'], [])
-                lswitches = [lswitch.get('data') for lswitch in lswitches]
-                self.synchronize_network(ctx, network, lswitches)
+        # Fetch neutron networks from database
+        filters = {'router:external': [False]}
+        if not scan_missing:
+            filters['id'] = neutron_net_ids
+        # TODO(salv-orlando): Filter out external networks
+        networks = self._plugin._get_collection_query(
+            ctx, models_v2.Network, filters=filters)
+        for network in networks:
+            lswitches = neutron_nvp_mappings.get(network['id'], [])
+            lswitches = [lswitch.get('data') for lswitch in lswitches]
+            self.synchronize_network(ctx, network, lswitches)
 
     def synchronize_router(self, context, neutron_router_data,
                            lrouter=None):
@@ -348,15 +348,15 @@ class NvpSynchronizer():
             return
         neutron_router_mappings = (
             dict((lr_uuid, self._nvp_cache[lr_uuid]) for lr_uuid in lr_uuids))
-        with ctx.session.begin(subtransactions=True):
-            # Fetch neutron routers from database
-            filters = ({} if scan_missing else
-                       {'id': neutron_router_mappings.keys()})
-            for router in self._plugin._get_collection_query(
-                ctx, l3_db.Router, filters=filters):
-                lrouter = neutron_router_mappings.get(router['id'])
-                self.synchronize_router(
-                    ctx, router, lrouter and lrouter.get('data'))
+        # Fetch neutron routers from database
+        filters = ({} if scan_missing else
+                   {'id': neutron_router_mappings.keys()})
+        routers = self._plugin._get_collection_query(
+            ctx, l3_db.Router, filters=filters)
+        for router in routers:
+            lrouter = neutron_router_mappings.get(router['id'])
+            self.synchronize_router(
+                ctx, router, lrouter and lrouter.get('data'))
 
     def synchronize_port(self, context, neutron_port_data,
                          lswitchport=None, ext_networks=None):
@@ -425,24 +425,24 @@ class NvpSynchronizer():
             if neutron_port_id:
                 neutron_port_mappings[neutron_port_id] = (
                     self._nvp_cache[lp_uuid])
-        with ctx.session.begin(subtransactions=True):
-            # Fetch neutron ports from database
-            # At the first sync we need to fetch all ports
-            filters = ({} if scan_missing else
-                       {'id': neutron_port_mappings.keys()})
-            # TODO(salv-orlando): Work out a solution for avoiding
-            # this query
-            ext_nets = [net['id'] for net in ctx.session.query(
-                models_v2.Network).join(
-                    external_net_db.ExternalNetwork,
-                    (models_v2.Network.id ==
-                     external_net_db.ExternalNetwork.network_id))]
-            for port in self._plugin._get_collection_query(
-                ctx, models_v2.Port, filters=filters):
-                lswitchport = neutron_port_mappings.get(port['id'])
-                self.synchronize_port(
-                    ctx, port, lswitchport and lswitchport.get('data'),
-                    ext_networks=ext_nets)
+        # Fetch neutron ports from database
+        # At the first sync we need to fetch all ports
+        filters = ({} if scan_missing else
+                   {'id': neutron_port_mappings.keys()})
+        # TODO(salv-orlando): Work out a solution for avoiding
+        # this query
+        ext_nets = [net['id'] for net in ctx.session.query(
+            models_v2.Network).join(
+                external_net_db.ExternalNetwork,
+                (models_v2.Network.id ==
+                 external_net_db.ExternalNetwork.network_id))]
+        ports = self._plugin._get_collection_query(
+            ctx, models_v2.Port, filters=filters)
+        for port in ports:
+            lswitchport = neutron_port_mappings.get(port['id'])
+            self.synchronize_port(
+                ctx, port, lswitchport and lswitchport.get('data'),
+                ext_networks=ext_nets)
 
     def _get_chunk_size(self, sp):
         # NOTE(salv-orlando): Try to use __future__ for this routine only?