On 15/02/2022 18:53, Oleksandr Mazur wrote:
> Whenever bridge driver hits the max capacity of MDBs, it disables
> the MC processing (by setting corresponding bridge option), but never
> notifies switchdev about such change (the notifiers are called only upon
> explicit setting of this option, through the registered netlink interface).
>
> This could lead to situation when Software MDB processing gets disabled,
> but this event never gets offloaded to the underlying Hardware.
>
> Fix this by adding a notify message in such case.
>
> Fixes: 147c1e9b902c ("switchdev: bridge: Offload multicast disabled")
>
> Signed-off-by: Oleksandr Mazur <oleksandr.mazur@xxxxxxxxxxx>
> ---
> V2:
> - target 'net' tree;
> - add missed 'Fixes' tag;
> - remove mc_disabled retcode check, as well as WARN_ON in case of err;
> ---
> net/bridge/br_multicast.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
> index de2409889489..db4f2641d1cd 100644
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
> @@ -82,6 +82,9 @@ static void br_multicast_find_del_pg(struct net_bridge *br,
> struct net_bridge_port_group *pg);
> static void __br_multicast_stop(struct net_bridge_mcast *brmctx);
>
> +static int br_mc_disabled_update(struct net_device *dev, bool value,
> + struct netlink_ext_ack *extack);
> +
> static struct net_bridge_port_group *
> br_sg_port_find(struct net_bridge *br,
> struct net_bridge_port_group_sg_key *sg_p)
> @@ -1156,6 +1159,7 @@ struct net_bridge_mdb_entry *br_multicast_new_group(struct net_bridge *br,
> return mp;
>
> if (atomic_read(&br->mdb_hash_tbl.nelems) >= br->hash_max) {
> + br_mc_disabled_update(br->dev, false, NULL);
> br_opt_toggle(br, BROPT_MULTICAST_ENABLED, false);
> return ERR_PTR(-E2BIG);
> }
nit: you don't have to leave empty new line between Fixes and Signed-off-by.
Patch looks good to me.
Acked-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxx>
