Subject: Re: [PATCH net-next 01/14] net: bridge: multicast: Propagate br_mc_disabled_update() return

From: Ido Schimmel <[email-masked]>
Date: Thu, 17 Jan 2019 13:47:40 +0000

On Wed, Jan 16, 2019 at 12:00:49PM -0800, Florian Fainelli wrote:
> Some Ethernet switches might not be able to support disabling multicast
> flooding globally when e.g: several bridges span the same physical
> device, propagate the return value of br_mc_disabled_update() such that
> this propagates correctly to user-space.
> 
> Signed-off-by: Florian Fainelli <[email-masked]>
> ---
>  net/bridge/br_multicast.c | 19 ++++++++++++++-----
>  1 file changed, 14 insertions(+), 5 deletions(-)
> 
> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
> index 3aeff0895669..09fc92541873 100644
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
> @@ -813,7 +813,7 @@ static void br_ip6_multicast_port_query_expired(struct timer_list *t)
>  }
>  #endif
>  
> -static void br_mc_disabled_update(struct net_device *dev, bool value)
> +static int br_mc_disabled_update(struct net_device *dev, bool value)
>  {
>  	struct switchdev_attr attr = {
>  		.orig_dev = dev,
> @@ -822,11 +822,13 @@ static void br_mc_disabled_update(struct net_device *dev, bool value)
>  		.u.mc_disabled = !value,
>  	};
>  
> -	switchdev_port_attr_set(dev, &attr);
> +	return switchdev_port_attr_set(dev, &attr);

Did you test this for veth? If switchdev ops are not defined, this
returns -EOPNOTSUPP. See __br_vlan_filter_toggle() for reference

>  }
>  
>  int br_multicast_add_port(struct net_bridge_port *port)
>  {
> +	int ret;
> +
>  	port->multicast_router = MDB_RTR_TYPE_TEMP_QUERY;
>  
>  	timer_setup(&port->multicast_router_timer,
> @@ -837,8 +839,11 @@ int br_multicast_add_port(struct net_bridge_port *port)
>  	timer_setup(&port->ip6_own_query.timer,
>  		    br_ip6_multicast_port_query_expired, 0);
>  #endif
> -	br_mc_disabled_update(port->dev,
> -			      br_opt_get(port->br, BROPT_MULTICAST_ENABLED));
> +	ret = br_mc_disabled_update(port->dev,
> +				    br_opt_get(port->br,
> +					       BROPT_MULTICAST_ENABLED));
> +	if (ret)
> +		return ret;
>  
>  	port->mcast_stats = netdev_alloc_pcpu_stats(struct bridge_mcast_stats);
>  	if (!port->mcast_stats)
> @@ -1937,12 +1942,16 @@ static void br_multicast_start_querier(struct net_bridge *br,
>  int br_multicast_toggle(struct net_bridge *br, unsigned long val)
>  {
>  	struct net_bridge_port *port;
> +	int err;
>  
>  	spin_lock_bh(&br->multicast_lock);
>  	if (!!br_opt_get(br, BROPT_MULTICAST_ENABLED) == !!val)
>  		goto unlock;
>  
> -	br_mc_disabled_update(br->dev, val);
> +	err = br_mc_disabled_update(br->dev, val);
> +	if (err)
> +		goto unlock;
> +
>  	br_opt_toggle(br, BROPT_MULTICAST_ENABLED, !!val);
>  	if (!br_opt_get(br, BROPT_MULTICAST_ENABLED))
>  		goto unlock;

You never return the error

> -- 
> 2.17.1