Linux Ethernet Bridging - Sep 2020 - [Bridge] [PATCH net-next] net: bridge: mcast: remove only S, G port groups from sg_port hash

From: Nikolay Aleksandrov <nikolay at nvidia.com>

We should remove a group from the sg_port hash only if it's an S,G
entry. This makes it correct and more symmetric with group add. Also
since *,G groups are not added to that hash we can hide a bug.

Fixes: 085b53c8beab ("net: bridge: mcast: add sg_port rhashtable")
Signed-off-by: Nikolay Aleksandrov <nikolay at nvidia.com>
---
 net/bridge/br_multicast.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 66eb62ded192..eae898c3cff7 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -590,17 +590,18 @@ void br_multicast_del_pg(struct net_bridge_mdb_entry *mp,
 	struct net_bridge_group_src *ent;
 	struct hlist_node *tmp;
 
-	rhashtable_remove_fast(&br->sg_port_tbl, &pg->rhnode,
-			       br_sg_port_rht_params);
 	rcu_assign_pointer(*pp, pg->next);
 	hlist_del_init(&pg->mglist);
 	hlist_for_each_entry_safe(ent, tmp, &pg->src_list, node)
 		br_multicast_del_group_src(ent);
 	br_mdb_notify(br->dev, mp, pg, RTM_DELMDB);
-	if (!br_multicast_is_star_g(&mp->addr))
+	if (!br_multicast_is_star_g(&mp->addr)) {
+		rhashtable_remove_fast(&br->sg_port_tbl, &pg->rhnode,
+				       br_sg_port_rht_params);
 		br_multicast_sg_del_exclude_ports(mp);
-	else
+	} else {
 		br_multicast_star_g_handle_mode(pg, MCAST_INCLUDE);
+	}
 	hlist_add_head(&pg->mcast_gc.gc_node, &br->mcast_gc_list);
 	queue_work(system_long_wq, &br->mcast_gc_work);
 
-- 
2.25.4

From: Nikolay Aleksandrov <razor at blackwall.org>
Date: Fri, 25 Sep 2020 13:25:49 +0300
> From: Nikolay Aleksandrov <nikolay at nvidia.com>
> 
> We should remove a group from the sg_port hash only if it's an S,G
> entry. This makes it correct and more symmetric with group add. Also
> since *,G groups are not added to that hash we can hide a bug.
> 
> Fixes: 085b53c8beab ("net: bridge: mcast: add sg_port
rhashtable")
> Signed-off-by: Nikolay Aleksandrov <nikolay at nvidia.com>
Applied, thanks.