From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: 3.15-rc4: circular locking dependency triggered by dm-multipath Date: Tue, 27 May 2014 09:22:28 -0400 Message-ID: <20140527132228.GA10955@redhat.com> References: <5368ABE8.9050909@acm.org> <536B1CC1.6080709@suse.de> <53832919.8080500@acm.org> <53832F2B.9060808@suse.de> <53833183.7080106@acm.org> <538333AC.60103@suse.de> <53833730.50509@suse.de> <538338D5.4080804@suse.de> <538355B3.9060100@acm.org> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <538355B3.9060100@acm.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Bart Van Assche Cc: dm-devel@redhat.com List-Id: dm-devel.ids On Mon, May 26 2014 at 10:54am -0400, Bart Van Assche wrote: > On 05/26/14 14:51, Hannes Reinecke wrote: > > Or, better still, try the attached patch. > > There's one more instance where lockdep might complain. > > Does anyone know whether it's safe to revert commit 4cdd2ad780 ? Yes, it should be reverted, otherwise multipath_ioctl is using inconsistent lock order. I should've waited for test confirmation before sending the previous "fix" upstream. It made the lock order consistent (but consistently wrong). > Anyway, > I ran a test with v3.15-rc7 + your patch + 4cdd2ad780 reverted and that > test ran fine. I didn't encounter any lockups nor any lockdep > complaints. The test I ran was to run a fio I/O verification test on top > of a dm-multipath device. That multipath device was created on top of > several SCSI device nodes created by the ib_srp driver. About once every > 30 seconds a cable removal / reinsertion was simulated via the > ibportstate command. Great, thanks. I'll try to get this queued for Linus this week.