net: bridge: mcast: factor out port group del

In order to avoid future errors and reduce code duplication we should
factor out the port group del sequence. This allows us to have one
function which takes care of all details when removing a port group.

v4: set pg's fast leave flag when deleting due to fast leave
    move the patch before adding source lists

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/bridge/br_mdb.c

@@ -764,16 +764,8 @@ static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
 		if (p->port->state == BR_STATE_DISABLED)
 			goto unlock;
 
-		__mdb_entry_fill_flags(entry, p->flags);
-		rcu_assign_pointer(*pp, p->next);
-		hlist_del_init(&p->mglist);
-		del_timer(&p->timer);
-		kfree_rcu(p, rcu);
+		br_multicast_del_pg(mp, p, pp);
 		err = 0;
-
-		if (!mp->ports && !mp->host_joined &&
-		    netif_running(br->dev))
-			mod_timer(&mp->timer, jiffies);
 		break;
 	}
 

net/bridge/br_multicast.c

@@ -163,8 +163,24 @@ static void br_multicast_group_expired(struct timer_list *t)
 	spin_unlock(&br->multicast_lock);
 }
 
-static void br_multicast_del_pg(struct net_bridge *br,
-				struct net_bridge_port_group *pg)
+void br_multicast_del_pg(struct net_bridge_mdb_entry *mp,
+			 struct net_bridge_port_group *pg,
+			 struct net_bridge_port_group __rcu **pp)
+{
+	struct net_bridge *br = pg->port->br;
+
+	rcu_assign_pointer(*pp, pg->next);
+	hlist_del_init(&pg->mglist);
+	del_timer(&pg->timer);
+	br_mdb_notify(br->dev, pg->port, &pg->addr, RTM_DELMDB, pg->flags);
+	kfree_rcu(pg, rcu);
+
+	if (!mp->ports && !mp->host_joined && netif_running(br->dev))
+		mod_timer(&mp->timer, jiffies);
+}
+
+static void br_multicast_find_del_pg(struct net_bridge *br,
+				     struct net_bridge_port_group *pg)
 {
 	struct net_bridge_mdb_entry *mp;
 	struct net_bridge_port_group *p;
@@ -180,17 +196,7 @@ static void br_multicast_del_pg(struct net_bridge *br,
 		if (p != pg)
 			continue;
 
-		rcu_assign_pointer(*pp, p->next);
-		hlist_del_init(&p->mglist);
-		del_timer(&p->timer);
-		br_mdb_notify(br->dev, p->port, &pg->addr, RTM_DELMDB,
-			      p->flags);
-		kfree_rcu(p, rcu);
-
-		if (!mp->ports && !mp->host_joined &&
-		    netif_running(br->dev))
-			mod_timer(&mp->timer, jiffies);
-
+		br_multicast_del_pg(mp, pg, pp);
 		return;
 	}
 
@@ -207,7 +213,7 @@ static void br_multicast_port_group_expired(struct timer_list *t)
 	    hlist_unhashed(&pg->mglist) || pg->flags & MDB_PG_FLAGS_PERMANENT)
 		goto out;
 
-	br_multicast_del_pg(br, pg);
+	br_multicast_find_del_pg(br, pg);
 
 out:
 	spin_unlock(&br->multicast_lock);
@@ -852,7 +858,7 @@ void br_multicast_del_port(struct net_bridge_port *port)
 	/* Take care of the remaining groups, only perm ones should be left */
 	spin_lock_bh(&br->multicast_lock);
 	hlist_for_each_entry_safe(pg, n, &port->mglist, mglist)
-		br_multicast_del_pg(br, pg);
+		br_multicast_find_del_pg(br, pg);
 	spin_unlock_bh(&br->multicast_lock);
 	del_timer_sync(&port->multicast_router_timer);
 	free_percpu(port->mcast_stats);
@@ -901,7 +907,7 @@ void br_multicast_disable_port(struct net_bridge_port *port)
 	spin_lock(&br->multicast_lock);
 	hlist_for_each_entry_safe(pg, n, &port->mglist, mglist)
 		if (!(pg->flags & MDB_PG_FLAGS_PERMANENT))
-			br_multicast_del_pg(br, pg);
+			br_multicast_find_del_pg(br, pg);
 
 	__del_port_router(port);
 
@@ -1407,16 +1413,8 @@ br_multicast_leave_group(struct net_bridge *br,
 			if (p->flags & MDB_PG_FLAGS_PERMANENT)
 				break;
 
-			rcu_assign_pointer(*pp, p->next);
-			hlist_del_init(&p->mglist);
-			del_timer(&p->timer);
-			kfree_rcu(p, rcu);
-			br_mdb_notify(br->dev, port, group, RTM_DELMDB,
-				      p->flags | MDB_PG_FLAGS_FAST_LEAVE);
-
-			if (!mp->ports && !mp->host_joined &&
-			    netif_running(br->dev))
-				mod_timer(&mp->timer, jiffies);
+			p->flags |= MDB_PG_FLAGS_FAST_LEAVE;
+			br_multicast_del_pg(mp, p, pp);
 		}
 		goto out;
 	}

net/bridge/br_private.h

@@ -777,6 +777,9 @@ void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
 		   struct br_ip *group, int type, u8 flags);
 void br_rtr_notify(struct net_device *dev, struct net_bridge_port *port,
 		   int type);
+void br_multicast_del_pg(struct net_bridge_mdb_entry *mp,
+			 struct net_bridge_port_group *pg,
+			 struct net_bridge_port_group __rcu **pp);
 void br_multicast_count(struct net_bridge *br, const struct net_bridge_port *p,
 			const struct sk_buff *skb, u8 type, u8 dir);
 int br_multicast_init_stats(struct net_bridge *br);