Re: [Patch v2 net-next 3/3] net: bridge: mcast: Notify on mdb offload failure

[Joseph Huang]

On 4/4/2025 6:29 AM, Nikolay Aleksandrov wrote:
> On 4/4/25 02:44, Joseph Huang wrote:
> > Notify user space on mdb offload failure if mdb_offload_fail_notification
> > is set.
> >
> > Signed-off-by: Joseph Huang <Joseph.Huang@xxxxxxxxxx>
> > ---
> >   net/bridge/br_mdb.c       | 26 +++++++++++++++++++++-----
> >   net/bridge/br_private.h   |  9 +++++++++
> >   net/bridge/br_switchdev.c |  4 ++++
> >   3 files changed, 34 insertions(+), 5 deletions(-)
>
> The patch looks good, but one question - it seems we'll mark mdb entries with
> "offload failed" when we get -EOPNOTSUPP as an error as well. Is that intended?
>
> That is, if the option is enabled and we have mixed bridge ports, we'll mark mdbs
> to the non-switch ports as offload failed, but it is not due to a switch offload
> error.

Good catch. No, that was not intended.

What if we short-circuit and just return like you'd suggested initially 
if err == -EOPNOTSUPP?

> > diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
> > index 40f0b16e4df8..9b5005d0742a 100644
> > --- a/net/bridge/br_switchdev.c
> > +++ b/net/bridge/br_switchdev.c
> > @@ -504,6 +504,7 @@ static void br_switchdev_mdb_complete(struct net_device *dev, int err, void *pri
> >   	struct net_bridge_mdb_entry *mp;
> >   	struct net_bridge_port *port = data->port;
> >   	struct net_bridge *br = port->br;
> > +	u8 old_flags;
> >   

+	if (err == -EOPNOTSUPP)
+		goto notsupp;

> >   	spin_lock_bh(&br->multicast_lock);
> >   	mp = br_mdb_ip_get(br, &data->ip);
> > @@ -514,7 +515,10 @@ static void br_switchdev_mdb_complete(struct net_device *dev, int err, void *pri
> >   		if (p->key.port != port)
> >   			continue;
> >   
> > +		old_flags = p->flags;
> >   		br_multicast_set_pg_offload_flags(p, !err);
> > +		if (br_mdb_should_notify(br, old_flags ^ p->flags))
> > +			br_mdb_flag_change_notify(br->dev, mp, p);
> >   	}
> >   out:
> >   	spin_unlock_bh(&br->multicast_lock);

+ notsupp:
	kfree(priv);