From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Shaohua Li , NeilBrown , Kamal Mostafa Subject: [PATCH 3.8 61/91] raid5: set bio bi_vcnt 0 for discard request Date: Thu, 7 Nov 2013 18:15:16 -0800 Message-Id: <1383876946-2396-62-git-send-email-kamal@canonical.com> In-Reply-To: <1383876946-2396-1-git-send-email-kamal@canonical.com> References: <1383876946-2396-1-git-send-email-kamal@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.8.13.13 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Shaohua Li commit 37c61ff31e9b5e3fcf3cc6579f5c68f6ad40c4b1 upstream. SCSI layer will add new payload for discard request. If two bios are merged to one, the second bio has bi_vcnt 1 which is set in raid5. This will confuse SCSI and cause oops. Suitable for backport to 3.7+ Reported-by: Jes Sorensen Signed-off-by: Shaohua Li Signed-off-by: NeilBrown Acked-by: Martin K. Petersen [ kamal: backport to 3.8 (context) ] Signed-off-by: Kamal Mostafa --- drivers/md/raid5.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 5b022b1..7ace380 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -672,6 +672,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) bi->bi_io_vec[0].bv_offset = 0; bi->bi_size = STRIPE_SIZE; bi->bi_next = NULL; + /* + * If this is discard request, set bi_vcnt 0. We don't + * want to confuse SCSI because SCSI will replace payload + */ + if (rw & REQ_DISCARD) + bi->bi_vcnt = 0; if (rrdev) set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags); @@ -706,6 +712,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) rbi->bi_io_vec[0].bv_offset = 0; rbi->bi_size = STRIPE_SIZE; rbi->bi_next = NULL; + /* + * If this is discard request, set bi_vcnt 0. We don't + * want to confuse SCSI because SCSI will replace payload + */ + if (rw & REQ_DISCARD) + rbi->bi_vcnt = 0; if (conf->mddev->gendisk) trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev), rbi, disk_devt(conf->mddev->gendisk), -- 1.8.1.2