[PATCH] dm: drop unnecessary assignment of md->queue

[PATCH] dm: drop unnecessary assignment of md->queue

[Bob Liu]

md->queue and q are the same thing in dm_init_request_based_queue() and
dm_init_request_based_blk_mq_queue().

Also drop the temporary struct request_queue *q.

Signed-off-by: Bob Liu <bob.liu@oracle.com>
---
 drivers/md/dm.c |    7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 5df4048..4f1f317 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2605,17 +2605,13 @@ static void init_rq_based_worker_thread(struct mapped_device *md)
  */
 static int dm_init_request_based_queue(struct mapped_device *md)
 {
-	struct request_queue *q = NULL;
-
 	/* Fully initialize the queue */
-	q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL);
-	if (!q)
+	if (!blk_init_allocated_queue(md->queue, dm_request_fn, NULL))
 		return -EINVAL;
 
 	/* disable dm_request_fn's merge heuristic by default */
 	md->seq_rq_merge_deadline_usecs = 0;
 
-	md->queue = q;
 	dm_init_old_md_queue(md);
 	blk_queue_softirq_done(md->queue, dm_softirq_done);
 	blk_queue_prep_rq(md->queue, dm_prep_fn);
@@ -2740,7 +2736,6 @@ static int dm_init_request_based_blk_mq_queue(struct mapped_device *md)
 		err = PTR_ERR(q);
 		goto out_tag_set;
 	}
-	md->queue = q;
 	dm_init_md_queue(md);
 
 	/* backfill 'mq' sysfs registration normally done in blk_register_queue */
-- 
1.7.10.4

Re: dm: drop unnecessary assignment of md->queue

[Mike Snitzer]

On Wed, Feb 24 2016 at  3:15am -0500,
Bob Liu <bob.liu@oracle.com> wrote:

> md->queue and q are the same thing in dm_init_request_based_queue() and
> dm_init_request_based_blk_mq_queue().
> 
> Also drop the temporary struct request_queue *q.

Yeah, I carried the extra assignment just as a form of documentation but
your patch is correct (they aren't needed).  I've rebased your patch
ontop of linux-dm.git's 'dm-4.6' and have staged it in linux-next.