bridge: send query as soon as leave is received

Continue sending queries when leave is received if the user marks
it as a querier.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Adam Baker <linux@baker-net.org.uk>
Signed-off-by: NCong Wang <amwang@redhat.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/bridge/br_multicast.c

@@ -1250,6 +1250,32 @@ static void br_multicast_leave_group(struct net_bridge *br,
 	if (!mp)
 		goto out;
 
+	if (br->multicast_querier &&
+	    !timer_pending(&br->multicast_querier_timer)) {
+		__br_multicast_send_query(br, port, &mp->addr);
+
+		time = jiffies + br->multicast_last_member_count *
+				 br->multicast_last_member_interval;
+		mod_timer(port ? &port->multicast_query_timer :
+				 &br->multicast_query_timer, time);
+
+		for (p = mlock_dereference(mp->ports, br);
+		     p != NULL;
+		     p = mlock_dereference(p->next, br)) {
+			if (p->port != port)
+				continue;
+
+			if (!hlist_unhashed(&p->mglist) &&
+			    (timer_pending(&p->timer) ?
+			     time_after(p->timer.expires, time) :
+			     try_to_del_timer_sync(&p->timer) >= 0)) {
+				mod_timer(&p->timer, time);
+			}
+
+			break;
+		}
+	}
+
 	if (port && (port->flags & BR_MULTICAST_FAST_LEAVE)) {
 		struct net_bridge_port_group __rcu **pp;