block: set make_request_fn manually in blk_mq_update_nr_hw_queues

Calling blk_queue_make_request resets a bunch of settings on the
request_queue, but all we really want is to update the make_request_fn,
so do this directly so we don't lose things like the logical and
physical block sizes.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7412191aee57..ade89197a4f1 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2629,10 +2629,14 @@ void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
         list_for_each_entry(q, &set->tag_list, tag_set_list) {
                 blk_mq_realloc_hw_ctxs(set, q);
 
+                /*
+                 * Manually set the make_request_fn as blk_queue_make_request
+                 * resets a lot of the queue settings.
+                 */
                 if (q->nr_hw_queues > 1)
-                        blk_queue_make_request(q, blk_mq_make_request);
+                        q->make_request_fn = blk_mq_make_request;
                 else
-                        blk_queue_make_request(q, blk_sq_make_request);
+                        q->make_request_fn = blk_sq_make_request;
 
                 blk_mq_queue_reinit(q, cpu_online_mask);
         }