Subject: Re: [patch net-next-2.6 6/8] bonding: move processing of recv handlers into handle_frame()

From: Nicolas de Pesloüan<[email-masked]>
Date: Sun, 06 Mar 2011 18:37:28 +0100

Le 06/03/2011 17:32, Michał Mirosław a écrit :
[snip]

> Is there a particular reason why this ARP monitoring can't be done in
> userspace (e.g. on AF_PACKET with suitable filter)? Marking slaves
> up/down as their link goes in that direction is easy, but as more and
> more link-state detecting methods/algorithms get added this is
> becoming more of a mess.

Moving as much as possible of bonding into userspace is a long standing target.

I think we currently lack a good way to notify the bonding driver that a given slave is available or 
not. Bringing the slave down on link failure is not appropriate, because it would prevent userspace 
from receiving the ARP packets that would bring the slave up again upon link return.

The only thing we can do is writing into /sys/class/net/bond0/bonding/active_slave, to force the 
active_slave. And this is strictly limited to active-backup mode.

I will let Jay / Andy comment on the general problem.

	Nicolas.