On Fri, Feb 11, 2022 at 03:14:26PM +0200, 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. > > Signed-off-by: Oleksandr Mazur <oleksandr.mazur@xxxxxxxxxxx> > --- > net/bridge/br_multicast.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c > index de2409889489..d53c08906bc8 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 +1159,8 @@ 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) { > + err = br_mc_disabled_update(br->dev, false, NULL); > + WARN_ON(err && err != -EOPNOTSUPP); What is the purpose of the WARN_ON()? There are a lot of operations that can fail in rollback paths, but we never WARN_ON() there I suggest: br_mc_disabled_update(br->dev, false, NULL); > br_opt_toggle(br, BROPT_MULTICAST_ENABLED, false); > return ERR_PTR(-E2BIG); > } > -- > 2.17.1 >