From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755418Ab3HBKoR (ORCPT ); Fri, 2 Aug 2013 06:44:17 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:37350 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030294Ab3HBKKr (ORCPT ); Fri, 2 Aug 2013 06:10:47 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joe Lawrence , NeilBrown Subject: [ 46/99] md/raid1: fix bio handling problems in process_checks() Date: Fri, 2 Aug 2013 18:07:59 +0800 Message-Id: <20130802100232.513222218@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.4.841.g1a3f60e In-Reply-To: <20130802100225.478715166@linuxfoundation.org> References: <20130802100225.478715166@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown commit 30bc9b53878a9921b02e3b5bc4283ac1c6de102a upstream. Recent change to use bio_copy_data() in raid1 when repairing an array is faulty. The underlying may have changed the bio in various ways using bio_advance and these need to be undone not just for the 'sbio' which is being copied to, but also the 'pbio' (primary) which is being copied from. So perform the reset on all bios that were read from and do it early. This also ensure that the sbio->bi_io_vec[j].bv_len passed to memcmp is correct. This fixes a crash during a 'check' of a RAID1 array. The crash was introduced in 3.10 so this is suitable for 3.10-stable. Reported-by: Joe Lawrence Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/raid1.c | 53 ++++++++++++++++++++++++++++++----------------------- 1 file changed, 30 insertions(+), 23 deletions(-) --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1848,6 +1848,36 @@ static int process_checks(struct r1bio * int i; int vcnt; + /* Fix variable parts of all bios */ + vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9); + for (i = 0; i < conf->raid_disks * 2; i++) { + int j; + int size; + struct bio *b = r1_bio->bios[i]; + if (b->bi_end_io != end_sync_read) + continue; + /* fixup the bio for reuse */ + bio_reset(b); + b->bi_vcnt = vcnt; + b->bi_size = r1_bio->sectors << 9; + b->bi_sector = r1_bio->sector + + conf->mirrors[i].rdev->data_offset; + b->bi_bdev = conf->mirrors[i].rdev->bdev; + b->bi_end_io = end_sync_read; + b->bi_private = r1_bio; + + size = b->bi_size; + for (j = 0; j < vcnt ; j++) { + struct bio_vec *bi; + bi = &b->bi_io_vec[j]; + bi->bv_offset = 0; + if (size > PAGE_SIZE) + bi->bv_len = PAGE_SIZE; + else + bi->bv_len = size; + size -= PAGE_SIZE; + } + } for (primary = 0; primary < conf->raid_disks * 2; primary++) if (r1_bio->bios[primary]->bi_end_io == end_sync_read && test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) { @@ -1856,12 +1886,10 @@ static int process_checks(struct r1bio * break; } r1_bio->read_disk = primary; - vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9); for (i = 0; i < conf->raid_disks * 2; i++) { int j; struct bio *pbio = r1_bio->bios[primary]; struct bio *sbio = r1_bio->bios[i]; - int size; if (sbio->bi_end_io != end_sync_read) continue; @@ -1887,27 +1915,6 @@ static int process_checks(struct r1bio * rdev_dec_pending(conf->mirrors[i].rdev, mddev); continue; } - /* fixup the bio for reuse */ - bio_reset(sbio); - sbio->bi_vcnt = vcnt; - sbio->bi_size = r1_bio->sectors << 9; - sbio->bi_sector = r1_bio->sector + - conf->mirrors[i].rdev->data_offset; - sbio->bi_bdev = conf->mirrors[i].rdev->bdev; - sbio->bi_end_io = end_sync_read; - sbio->bi_private = r1_bio; - - size = sbio->bi_size; - for (j = 0; j < vcnt ; j++) { - struct bio_vec *bi; - bi = &sbio->bi_io_vec[j]; - bi->bv_offset = 0; - if (size > PAGE_SIZE) - bi->bv_len = PAGE_SIZE; - else - bi->bv_len = size; - size -= PAGE_SIZE; - } bio_copy_data(sbio, pbio); }