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Commit 6599c84e authored by Bart Van Assche's avatar Bart Van Assche Committed by Mike Snitzer
Browse files

dm mpath: do not modify *__clone if blk_mq_alloc_request() fails 



Purely cleanup, avoids potential for strange coding bugs.  But in
reality if __multipath_map() fails the caller has no business looking at
*__clone.

Signed-off-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 4813577f

drivers/md/dm-mpath.c

+8 −7
Original line number Diff line number Diff line
@@ -580,16 +580,17 @@ static int __multipath_map(struct dm_target *ti, struct request *clone, 
		 * .request_fn stacked on blk-mq path(s) and

		 * blk-mq stacked on blk-mq path(s).

		 */

		*__clone = blk_mq_alloc_request(bdev_get_queue(bdev),

		clone = blk_mq_alloc_request(bdev_get_queue(bdev),

					     rq_data_dir(rq), BLK_MQ_REQ_NOWAIT);

		if (IS_ERR(*__clone)) {

			/* ENOMEM, requeue */

		if (IS_ERR(clone)) {

			/* EBUSY, ENODEV or EWOULDBLOCK: requeue */

			clear_request_fn_mpio(m, map_context);

			return r;

		}

		(*__clone)->bio = (*__clone)->biotail = NULL;

		(*__clone)->rq_disk = bdev->bd_disk;

		(*__clone)->cmd_flags |= REQ_FAILFAST_TRANSPORT;

		clone->bio = clone->biotail = NULL;

		clone->rq_disk = bdev->bd_disk;

		clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;

		*__clone = clone;

	}



	if (pgpath->pg->ps.type->start_io)