From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH] md: Partially revert 2f6db2a7, which broke raid5
Date: Sat, 18 May 2013 09:05:15 +0200
Message-ID: <20130518070515.GL19781@kernel.dk>
References: <20130517213223.GA2530@gmail.com>
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To: Calvin Owens <jcalvinowens@gmail.com>
Cc: Kent Overstreet <koverstreet@google.com>, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, NeilBrown <neilb@suse.de>, majianpeng@gmail.com
List-Id: linux-raid.ids

On Fri, May 17 2013, Calvin Owens wrote:
> Commit 2f6db2a7 was part of a series that cleaned up mdraid code by
> replacing explicit re-initialization of struct bio with bio_reset().
> 
> In raid5 it incorrectly assumed that a couple initializations of its
> members was a full reset, erasing the existing data and unconditionally
> triggering the following BUG when assembling arrays:
> 
> [   14.653072] kernel BUG at /home/calvinow/git/linux/drivers/scsi/scsi_lib.c:1196!
> [   14.653074] invalid opcode: 0000 [#1] PREEMPT SMP
> [   14.653076] CPU: 1 PID: 40 Comm: kworker/1:0H Not tainted 3.10.0-rc1-amd-00279-g8f710dd #3
> [   14.653077] Hardware name: System manufacturer System Product Name/M5A88-M, BIOS 0601    09/20/2011
> [   14.653082] Workqueue: kblockd blk_delay_work
> <snip>
> [   14.653123] Call Trace:
> [   14.653126]  [<ffffffff81477248>] sd_prep_fn+0x2c8/0xb70
> [   14.653129]  [<ffffffff812c8b70>] ? deadline_remove_request.isra.9+0x50/0x90
> [   14.653132]  [<ffffffff812b8f5b>] blk_peek_request+0xdb/0x210
> [   14.653134]  [<ffffffff81465f15>] scsi_request_fn+0x45/0x4e0
> [   14.653136]  [<ffffffff812b6a51>] __blk_run_queue+0x31/0x40
> [   14.653138]  [<ffffffff812b6a84>] blk_delay_work+0x24/0x40
> [   14.653141]  [<ffffffff8105dc2a>] process_one_work+0x1da/0x490
> [   14.653143]  [<ffffffff8105dbcd>] ? process_one_work+0x17d/0x490
> [   14.653145]  [<ffffffff8105e32a>] worker_thread+0x11a/0x370
> [   14.653147]  [<ffffffff8105e210>] ? rescuer_thread+0x2f0/0x2f0
> [   14.653149]  [<ffffffff81066296>] kthread+0xd6/0xe0
> [   14.653151]  [<ffffffff810661c0>] ? __kthread_unpark+0x50/0x50
> [   14.653154]  [<ffffffff816e4d6c>] ret_from_fork+0x7c/0xb0
> [   14.653156]  [<ffffffff810661c0>] ? __kthread_unpark+0x50/0x50
> [   14.653172] Code: <snip>
> [   14.653174] RIP  [<ffffffff81467329>] scsi_setup_fs_cmnd+0x89/0x90
> 
> Signed-off-by: Calvin Owens <jcalvinowens@gmail.com>

Kent, there was a report on this issue yesterday as well. We need to get
this fixed up ASAP.

-- 
Jens Axboe