Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757497AbbGGNrw (ORCPT ); Tue, 7 Jul 2015 09:47:52 -0400 Received: from mail-pd0-f176.google.com ([209.85.192.176]:35973 "EHLO mail-pd0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757278AbbGGNrU (ORCPT ); Tue, 7 Jul 2015 09:47:20 -0400 Message-ID: <559BD866.6030305@kernel.dk> Date: Tue, 07 Jul 2015 07:47:18 -0600 From: Jens Axboe User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Mike Snitzer , "Martin K. Petersen" CC: 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 References: <20150701165740.GA1573@redhat.com> In-Reply-To: <20150701165740.GA1573@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2544 Lines: 51 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. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/