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: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 373e5e3..0caab4b 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -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),
- rq_data_dir(rq), BLK_MQ_REQ_NOWAIT);
- if (IS_ERR(*__clone)) {
- /* ENOMEM, requeue */
+ clone = blk_mq_alloc_request(bdev_get_queue(bdev),
+ rq_data_dir(rq), BLK_MQ_REQ_NOWAIT);
+ 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)
