Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752831Ab3ESRwY (ORCPT ); Sun, 19 May 2013 13:52:24 -0400 Received: from mail-da0-f41.google.com ([209.85.210.41]:46666 "EHLO mail-da0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752203Ab3ESRwV (ORCPT ); Sun, 19 May 2013 13:52:21 -0400 Date: Sun, 19 May 2013 10:51:45 -0700 From: Kent Overstreet To: Jens Axboe Cc: Calvin Owens , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, NeilBrown , majianpeng@gmail.com Subject: Re: [PATCH] md: Partially revert 2f6db2a7, which broke raid5 Message-ID: <20130519175145.GC19194@moria.home.lan> References: <20130517213223.GA2530@gmail.com> <20130518070515.GL19781@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130518070515.GL19781@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 Content-Length: 3667 Lines: 81 On Sat, May 18, 2013 at 09:05:15AM +0200, Jens Axboe wrote: > 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 > > > > [ 14.653123] Call Trace: > > [ 14.653126] [] sd_prep_fn+0x2c8/0xb70 > > [ 14.653129] [] ? deadline_remove_request.isra.9+0x50/0x90 > > [ 14.653132] [] blk_peek_request+0xdb/0x210 > > [ 14.653134] [] scsi_request_fn+0x45/0x4e0 > > [ 14.653136] [] __blk_run_queue+0x31/0x40 > > [ 14.653138] [] blk_delay_work+0x24/0x40 > > [ 14.653141] [] process_one_work+0x1da/0x490 > > [ 14.653143] [] ? process_one_work+0x17d/0x490 > > [ 14.653145] [] worker_thread+0x11a/0x370 > > [ 14.653147] [] ? rescuer_thread+0x2f0/0x2f0 > > [ 14.653149] [] kthread+0xd6/0xe0 > > [ 14.653151] [] ? __kthread_unpark+0x50/0x50 > > [ 14.653154] [] ret_from_fork+0x7c/0xb0 > > [ 14.653156] [] ? __kthread_unpark+0x50/0x50 > > [ 14.653172] Code: > > [ 14.653174] RIP [] scsi_setup_fs_cmnd+0x89/0x90 > > > > Signed-off-by: Calvin Owens > > Kent, there was a report on this issue yesterday as well. We need to get > this fixed up ASAP. Sorry for the delay - been vacationing. Reproduced the original bug, here's a patch that fixes it: commit 402f5db3708b2062795a384a3d8397cf702e27bc Author: Kent Overstreet Date: Sun May 19 10:27:07 2013 -0700 raid5: Initialize bi_vcnt The patch that converted raid5 to use bio_reset() forgot to initialize bi_vcnt. Signed-off-by: Kent Overstreet Cc: NeilBrown Cc: Jens Axboe Cc: linux-raid@vger.kernel.org diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 9359828..753f318 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -664,6 +664,7 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) bi->bi_rw |= REQ_FLUSH; + bi->bi_vcnt = 1; bi->bi_io_vec[0].bv_len = STRIPE_SIZE; bi->bi_io_vec[0].bv_offset = 0; bi->bi_size = STRIPE_SIZE; @@ -701,6 +702,7 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) else rbi->bi_sector = (sh->sector + rrdev->data_offset); + rbi->bi_vcnt = 1; rbi->bi_io_vec[0].bv_len = STRIPE_SIZE; rbi->bi_io_vec[0].bv_offset = 0; rbi->bi_size = STRIPE_SIZE; -- 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/