ovs_lib: Fix a race between get_port_tag_dict and port removal

get_port_tag_dict() gets a list of ports using get_port_name_list()
and then queries the db again for ports in the list.
It fails if some of ports disappeared in between.
This change fixes it by ignoring "not exist" errors in the later query.

Closes-Bug: #1444797
Change-Id: Ic54b644bb1d72a4664b70f124863d17805c26fff

diff --git a/neutron/agent/common/ovs_lib.py b/neutron/agent/common/ovs_lib.py
index 3004bc99b583bef6c471abfa5d56f9feec910fcd..1576b15806c111d3697b41e9de74406bcb85a170 100644 (file)
--- a/neutron/agent/common/ovs_lib.py
+++ b/neutron/agent/common/ovs_lib.py
@@ -388,7 +388,8 @@ class OVSBridge(BaseOVS):
 
         """
         port_names = self.get_port_name_list()
-        cmd = self.ovsdb.db_list('Port', port_names, columns=['name', 'tag'])
+        cmd = self.ovsdb.db_list('Port', port_names, columns=['name', 'tag'],
+                                 if_exists=True)
         results = cmd.execute(check_error=True)
         return {p['name']: p['tag'] for p in results}