ovn-controller: Remove old values from local_ids.

local_ids is supposed to be the set of interface iface-id values from
this chassis that correspond to OVN logical ports.  We use this for
detecting when an interface has been removed as well as if child-ports
should be bound to this chassis.

Old values were not being removed from local_ids.  The most immediate
effect of this was that once an interface has been removed from a
chassis, we would think a removal has occured *every* time through
binding_run and trigger the full binding processing.  This was
a performance problem.

The second problem this would cause is if a port that had child ports
was moved to another chassis.  We would end up with two chassis fighting
over the binding of the child ports.

Signed-off-by: Russell Bryant <[email protected]>
Acked-by: Ryan Moats <[email protected]>

ovn/controller/binding.c

@@ -103,6 +103,11 @@ get_local_iface_ids(const struct ovsrec_bridge *br_int,
      * that has been removed. */
     if (!changed && !sset_is_empty(&old_local_ids)) {
         changed = true;
+
+        const char *cur_id;
+        SSET_FOR_EACH(cur_id, &old_local_ids) {
+            sset_find_and_delete(&local_ids, cur_id);
+        }
     }
 
     sset_destroy(&old_local_ids);