From 37c61ff31e9b5e3fcf3cc6579f5c68f6ad40c4b1 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Sat, 19 Oct 2013 14:50:28 +0800 Subject: [PATCH] raid5: set bio bi_vcnt 0 for discard request 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+ Cc: stable@vger.kernel.org (v3.7+) Reported-by: Jes Sorensen Signed-off-by: Shaohua Li Signed-off-by: NeilBrown Acked-by: Martin K. Petersen --- drivers/md/raid5.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 7ff4f25..302d7cd 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -778,6 +778,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) bi->bi_io_vec[0].bv_len = STRIPE_SIZE; bi->bi_io_vec[0].bv_offset = 0; bi->bi_size = STRIPE_SIZE; + /* + * 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); @@ -816,6 +822,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) rbi->bi_io_vec[0].bv_len = STRIPE_SIZE; rbi->bi_io_vec[0].bv_offset = 0; rbi->bi_size = STRIPE_SIZE; + /* + * 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), -- 2.7.4