[v4] net: bridge: reduce multicast checks in fast path

[PATCH net-next v4 07/14] net: bridge: mcast: track active state, own MLD querier disappearance

Posted by Linus Lüssing 3 weeks, 6 days ago

This change ensures that the new multicast active state variable is
immediately unset if our internal IGMP/MLD querier was elected and
now disabled.

If no IGMP/MLD querier exists on the link then we can't reliably receive
IGMP/MLD reports and in turn can't ensure the completeness of our MDB
anymore either.

No functional change for the fast/data path yet.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
---
 net/bridge/br_multicast.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 2eebfb7c5ff9..f37a18f3713c 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -4945,6 +4945,7 @@ int br_multicast_set_querier(struct net_bridge_mcast *brmctx, unsigned long val)
 #endif
 
 unlock:
+	br_multicast_update_active(brmctx);
 	spin_unlock_bh(&brmctx->br->multicast_lock);
 
 	return 0;
-- 
2.53.0

Re: [PATCH net-next v4 07/14] net: bridge: mcast: track active state, own MLD querier disappearance

Posted by Ido Schimmel 3 weeks, 4 days ago

On Sat, Mar 07, 2026 at 05:45:41AM +0100, Linus Lüssing wrote:
> This change ensures that the new multicast active state variable is
> immediately unset if our internal IGMP/MLD querier was elected and
> now disabled.
> 
> If no IGMP/MLD querier exists on the link then we can't reliably receive
> IGMP/MLD reports and in turn can't ensure the completeness of our MDB
> anymore either.
> 
> No functional change for the fast/data path yet.
> 
> Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
> Reviewed-by: Ido Schimmel <idosch@nvidia.com>

Please take care of the comment I left last time regarding the subject:

https://lore.kernel.org/netdev/20260208160907.GG154003@shredder/