Subject: Re: [PATCH net-next v4 13/14] net: bridge: mcast: use combined active state in fast/data path

From: Ido Schimmel <[email-masked]>
Date: Mon, 9 Mar 2026 18:51:34 +0200

On Sat, Mar 07, 2026 at 05:45:47AM +0100, Linus Lüssing wrote:
> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
> index 6faa484dede7..aa2edb63a97b 100644
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
> @@ -1067,6 +1067,26 @@ static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge_mcast *brm
>  	return skb;
>  }
>  
> +static bool
> +__br_multicast_querier_exists(struct net_bridge_mcast *brmctx,
> +			      struct bridge_mcast_other_query *querier,

Both can be const

> +			      bool is_ipv6)
> +{
> +	bool own_querier_enabled;
> +
> +	if (brmctx->multicast_querier) {
> +		if (is_ipv6 && !br_opt_get(brmctx->br, BROPT_HAS_IPV6_ADDR))
> +			own_querier_enabled = false;
> +		else
> +			own_querier_enabled = true;
> +	} else {
> +		own_querier_enabled = false;
> +	}
> +
> +	return !timer_pending(&querier->delay_timer) &&
> +	       (own_querier_enabled || timer_pending(&querier->timer));
> +}
> +
>  static bool br_ip4_multicast_querier_exists(struct net_bridge_mcast *brmctx)

Same (br_ip6_multicast_querier_exists() as well)

>  {
>  	return __br_multicast_querier_exists(brmctx, &brmctx->ip4_other_query,
> @@ -1081,6 +1101,21 @@ static bool br_ip6_multicast_querier_exists(struct net_bridge_mcast *brmctx)
>  }
>  #endif
>  
> +static bool
> +br_multicast_querier_exists(struct net_bridge_mcast *brmctx, u16 proto)

Same

> +{
> +	switch (proto) {
> +	case ETH_P_IP:
> +		return br_ip4_multicast_querier_exists(brmctx);
> +#if IS_ENABLED(CONFIG_IPV6)
> +	case ETH_P_IPV6:
> +		return br_ip6_multicast_querier_exists(brmctx);
> +#endif
> +	default:
> +		return false;
> +	}
> +}

[...]

> +br_multicast_snooping_active(const struct net_bridge_mcast *brmctx,
> +			     __be16 eth_proto,
> +			     const struct net_bridge_mdb_entry *mdb)
>  {
> -	bool own_querier_enabled;
> -
> -	if (brmctx->multicast_querier) {
> -		if (is_ipv6 && !br_opt_get(brmctx->br, BROPT_HAS_IPV6_ADDR))
> -			own_querier_enabled = false;
> -		else
> -			own_querier_enabled = true;
> -	} else {
> -		own_querier_enabled = false;
> -	}
> -
> -	return !timer_pending(&querier->delay_timer) &&
> -	       (own_querier_enabled || timer_pending(&querier->timer));
> -}
> -
> -static inline bool br_multicast_querier_exists(struct net_bridge_mcast *brmctx,
> -					       struct ethhdr *eth,
> -					       const struct net_bridge_mdb_entry *mdb)
> -{
> -	switch (eth->h_proto) {
> -	case (htons(ETH_P_IP)):
> -		return __br_multicast_querier_exists(brmctx,
> -			&brmctx->ip4_other_query, false);
> +	switch (eth_proto) {
> +	case htons(ETH_P_IP):
> +		return READ_ONCE(brmctx->ip4_active);
>  #if IS_ENABLED(CONFIG_IPV6)

This can be removed given that 'ipv6_active' is always available

> -	case (htons(ETH_P_IPV6)):
> -		return __br_multicast_querier_exists(brmctx,
> -			&brmctx->ip6_other_query, true);
> +	case htons(ETH_P_IPV6):
> +		return READ_ONCE(brmctx->ip6_active);
>  #endif
>  	default:
>  		return !!mdb && br_group_is_l2(&mdb->addr);
> @@ -1458,9 +1437,10 @@ static inline bool br_multicast_is_router(struct net_bridge_mcast *brmctx,
>  	return false;
>  }