bridge: Optimize multiple unregistration

Speedup module unloading by factorizing synchronize_rcu() calls
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/bridge/br_if.c

@@ -154,7 +154,7 @@ static void del_nbp(struct net_bridge_port *p)
 }
 
 /* called with RTNL */
-static void del_br(struct net_bridge *br)
+static void del_br(struct net_bridge *br, struct list_head *head)
 {
 	struct net_bridge_port *p, *n;
 
@@ -165,7 +165,7 @@ static void del_br(struct net_bridge *br)
 	del_timer_sync(&br->gc_timer);
 
 	br_sysfs_delbr(br->dev);
-	unregister_netdevice(br->dev);
+	unregister_netdevice_queue(br->dev, head);
 }
 
 static struct net_device *new_bridge_dev(struct net *net, const char *name)
@@ -323,7 +323,7 @@ int br_del_bridge(struct net *net, const char *name)
 	}
 
 	else
-		del_br(netdev_priv(dev));
+		del_br(netdev_priv(dev), NULL);
 
 	rtnl_unlock();
 	return ret;
@@ -462,15 +462,14 @@ int br_del_if(struct net_bridge *br, struct net_device *dev)
 void br_net_exit(struct net *net)
 {
 	struct net_device *dev;
+	LIST_HEAD(list);
 
 	rtnl_lock();
-restart:
-	for_each_netdev(net, dev) {
-		if (dev->priv_flags & IFF_EBRIDGE) {
-			del_br(netdev_priv(dev));
-			goto restart;
-		}
-	}
+	for_each_netdev(net, dev)
+		if (dev->priv_flags & IFF_EBRIDGE)
+			del_br(netdev_priv(dev), &list);
+
+	unregister_netdevice_many(&list);
 	rtnl_unlock();
 
 }