Re: [PATCH net] bonding: properly stop queuing work when requested

[David Miller <davem@davemloft.net>]

From: Andy Gospodarek <andy@greyhouse.net>
Date: Fri, 23 Sep 2011 16:53:34 -0400

> During a test where a pair of bonding interfaces using ARP monitoring
> were both brought up and torn down (with an rmmod) repeatedly, a panic
> in the timer code was noticed.  I tracked this down and determined that
> any of the bonding functions that ran as workqueue handlers and requeued
> more work might not properly exit when the module was removed.
> 
> There was a flag protected by the bond lock called kill_timers that is
> set when the interface goes down or the module is removed, but many of
> the functions that monitor link status now unlock the bond lock to take
> rtnl first.  There is a chance that another CPU running the rmmod could
> get the lock and set kill_timers after the first check has passed.
> 
> This patch does not allow any function to queue work that will make
> itself run unless kill_timers is not set.  I also noticed while doing
> this work that bond_resend_igmp_join_requests did not have a check for
> kill_timers, so I added the needed call there as well.
> 
> Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
> Reported-by: Liang Zheng <lzheng@redhat.com>

Applied, thanks Andy.