raid5: set bio bi_vcnt 0 for discard request (37c61ff3) · Commits · 戴 / test

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 <Jes.Sorensen@redhat.com> Signed-off-by:

Shaohua Li <shli@fusionio.com> Signed-off-by:

NeilBrown <neilb@suse.de> Acked-by:

Martin K. Petersen <martin.petersen@oracle.com>

drivers/md/raid5.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -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),

Admin message