net: bridge: Add br_multicast_del_port_group()

Since cleaning up the effects of br_multicast_new_port_group() just
consists of delisting and freeing the memory, the function
br_mdb_add_group_star_g() inlines the corresponding code. In the following
patches, number of per-port and per-port-VLAN MDB entries is going to be
maintained, and that counter will have to be updated. Because that logic
is going to be hidden in the br_multicast module, introduce a new hook
intended to again remove a newly-created group.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_mdb.c

@@ -1099,8 +1099,7 @@ static int br_mdb_add_group_star_g(const struct br_mdb_config *cfg,
 	return 0;
 
 err_del_port_group:
-	hlist_del_init(&p->mglist);
-	kfree(p);
+	br_multicast_del_port_group(p);
 	return err;
 }
 

net/bridge/br_multicast.c

@@ -1326,6 +1326,17 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 	return p;
 }
 
+void br_multicast_del_port_group(struct net_bridge_port_group *p)
+{
+	struct net_bridge_port *port = p->key.port;
+
+	hlist_del_init(&p->mglist);
+	if (!br_multicast_is_star_g(&p->key.addr))
+		rhashtable_remove_fast(&port->br->sg_port_tbl, &p->rhnode,
+				       br_sg_port_rht_params);
+	kfree(p);
+}
+
 void br_multicast_host_join(const struct net_bridge_mcast *brmctx,
 			    struct net_bridge_mdb_entry *mp, bool notify)
 {

net/bridge/br_private.h

@@ -958,6 +958,7 @@ br_multicast_new_port_group(struct net_bridge_port *port,
 			    unsigned char flags, const unsigned char *src,
 			    u8 filter_mode, u8 rt_protocol,
 			    struct netlink_ext_ack *extack);
+void br_multicast_del_port_group(struct net_bridge_port_group *p);
 int br_mdb_hash_init(struct net_bridge *br);
 void br_mdb_hash_fini(struct net_bridge *br);
 void br_mdb_notify(struct net_device *dev, struct net_bridge_mdb_entry *mp,