From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757470AbbGGN5b (ORCPT ); Tue, 7 Jul 2015 09:57:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40949 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751757AbbGGN5X (ORCPT ); Tue, 7 Jul 2015 09:57:23 -0400 Date: Tue, 7 Jul 2015 09:57:21 -0400 From: Mike Snitzer To: Jens Axboe Cc: "Martin K. Petersen" , dm-devel@redhat.com, linux-kernel@vger.kernel.org, mpatocka@redhat.com Subject: Re: [RFC PATCH] bio integrity: do not assume bio_integrity_pool exists if bioset exists Message-ID: <20150707135721.GA16040@redhat.com> References: <20150701165740.GA1573@redhat.com> <559BD866.6030305@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <559BD866.6030305@kernel.dk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 07 2015 at 9:47am -0400, Jens Axboe wrote: > On 07/01/2015 10:57 AM, Mike Snitzer wrote: > >bio_integrity_alloc() and bio_integrity_free() assume that if a bio was > >allocated from a bioset that that bioset also had its bio_integrity_pool > >allocated using bioset_integrity_create(). This is a very bad > >assumption given that bioset_create() and bioset_integrity_create() are > >completely disjoint. Not all callers of bioset_create() have been > >trained to also call bioset_integrity_create() -- and they may not care > >to be. > > > >Fix this by falling back to kmalloc'ing 'struct bio_integrity_payload' > >rather than force all bioset consumers to (wastefully) preallocate a > >bio_integrity_pool that they very likely won't actually need (given the > >niche nature of the current block integrity support). > > > >Otherwise, a NULL pointer "Kernel BUG" with a trace like the following > >will be observed (as seen on s390x using zfcp storage) because dm-io > >doesn't use bioset_integrity_create() when creating its bioset: > > > > [ 791.643338] Call Trace: > > [ 791.643339] ([<00000003df98b848>] 0x3df98b848) > > [ 791.643341] [<00000000002c5de8>] bio_integrity_alloc+0x48/0xf8 > > [ 791.643348] [<00000000002c6486>] bio_integrity_prep+0xae/0x2f0 > > [ 791.643349] [<0000000000371e38>] blk_queue_bio+0x1c8/0x3d8 > > [ 791.643355] [<000000000036f8d0>] generic_make_request+0xc0/0x100 > > [ 791.643357] [<000000000036f9b2>] submit_bio+0xa2/0x198 > > [ 791.643406] [<000003ff801f9774>] dispatch_io+0x15c/0x3b0 [dm_mod] > > [ 791.643419] [<000003ff801f9b3e>] dm_io+0x176/0x2f0 [dm_mod] > > [ 791.643423] [<000003ff8074b28a>] do_reads+0x13a/0x1a8 [dm_mirror] > > [ 791.643425] [<000003ff8074b43a>] do_mirror+0x142/0x298 [dm_mirror] > > [ 791.643428] [<0000000000154fca>] process_one_work+0x18a/0x3f8 > > [ 791.643432] [<000000000015598a>] worker_thread+0x132/0x3b0 > > [ 791.643435] [<000000000015d49a>] kthread+0xd2/0xd8 > > [ 791.643438] [<00000000005bc0ca>] kernel_thread_starter+0x6/0xc > > [ 791.643446] [<00000000005bc0c4>] kernel_thread_starter+0x0/0xc > > > >Signed-off-by: Mike Snitzer > >Cc: stable@vger.kernel.org > >--- > > block/bio-integrity.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > Applied for this series. Awesome, thanks.