diff options
| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2016-11-15 15:34:32 -0800 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2016-11-21 09:52:10 -0500 |
| commit | 6599c84e4ce6e428180f9958c7c40aa4202d8072 (patch) | |
| tree | 1ca8b8f0ccc0e6139450ddfa30f7a6b4470c8a5f | |
| parent | 4813577f932050f33c29e2a35a01431814437700 (diff) | |
| download | linux-6599c84e4ce6e428180f9958c7c40aa4202d8072.tar.bz2 | |
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>
| -rw-r--r-- | drivers/md/dm-mpath.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 373e5e3eec78..0caab4bf3515 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) |