Re: [net-next,v2,05/14] net: bridge: mcast: track active state, foreign IGMP/MLD querier disappearance
From: Jakub Kicinski <kuba@kernel.org>
Date: 2026-02-07 04:56:07
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bridge, lkml
This is an AI-generated review of your patch. The human sending this email has considered the AI review valid, or at least plausible. For local reproduction steps see https://netdev-ai.bots.linux.dev/ai-local.html --- net: bridge: mcast: track active state, foreign IGMP/MLD querier disappearance This change ensures that the new multicast active state variable is unset again after a foreign IGMP/MLD querier has disappeared (default: 255 seconds). If no new, other IGMP/MLD querier took over then we can't reliably receive IGMP/MLD reports anymore and in turn can't ensure the completeness of our MDB anymore either.
quoted hunk ↗ jump to hunk
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index d5c623dce7eb..0fc29875db9c 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c@@ -1826,6 +1826,10 @@ static void br_multicast_querier_expired(struct net_bridge_mcast *brmctx, br_multicast_start_querier(brmctx, query); out: + /* another IGMP/MLD querier disappeared, set multicast state to inactive + * if our own querier is disabled, too + */ + br_multicast_update_active(brmctx); spin_unlock(&brmctx->br->multicast_lock); }
This isn't a bug, but I noticed a couple of unaddressed review comments from Ido Schimmel's feedback on v1 back in May 2025 that don't appear to have been incorporated into this v2 series. In __br_multicast_querier_exists() in net/bridge/br_private.h around line 1164, the 'is_ipv6' bool parameter is marked const. Since this is a pass-by-value parameter, the const qualifier doesn't provide any benefit. Should it be removed? Reference: https://lore.kernel.org/all/aDNPxdmDPYwasUEM@shredder/ (local) Also in br_multicast_querier_exists() in net/bridge/br_private.h around line 1182, the function takes a struct ethhdr *eth parameter but only uses eth->h_proto. Would it make more sense to either make the 'eth' parameter const, or just pass the EtherType (__be16) directly instead of the entire struct pointer? Reference: https://lore.kernel.org/all/aDNPxdmDPYwasUEM@shredder/ (local)