Re: [Patch] bonding: fix potential deadlock in bond_uninit()
From: Stephen Hemminger <hidden>
Date: 2010-03-31 23:02:45
Also in:
lkml
From: Stephen Hemminger <hidden>
Date: 2010-03-31 23:02:45
Also in:
lkml
On Wed, 31 Mar 2010 04:28:33 -0700 ebiederm@xmission.com (Eric W. Biederman) wrote:
Amerigo Wang [off-list ref] writes:quoted
bond_uninit() is invoked with rtnl_lock held, when it does destroy_workqueue() which will potentially flush all works in this workqueue, if we hold rtnl_lock again in the work function, it will deadlock. So unlock rtnl_lock before calling destroy_workqueue().Ouch. That seems rather rude to our caller, and likely very dangerous. Is this a deadlock you actually hit, or is this something lockdep warned about? My gut feel says we need to move the destroy_workqueue into the network device destructor. Eric
Why is there one workqueue per bond device rather than just one workqueue for all bonding devices controlled by the module instance? It would be cleaner on removal and less space and overhead. I can't see that doing arp/mii or alb work is high parallel and load activity.