Do not modify *__clone if blk_mq_alloc_request() fails. This makes
it easier to figure out what is going on if the caller accidentally
dereferences *__clone if blk_mq_alloc_request() failed.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
---
drivers/md/dm-mpath.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 1c97f0e..5c73818 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -582,16 +582,17 @@ 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 = clone;
+ clone->bio = clone->biotail = NULL;
+ clone->rq_disk = bdev->bd_disk;
+ clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
}
if (pgpath->pg->ps.type->start_io)
--
2.10.1
--
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