block: always assign default lock to queues

Move the assignment of a default lock below blk_init_queue() to
blk_queue_make_request(), so we also get to set the default lock
for ->make_request_fn() based drivers. This is important since the
queue flag locking requires a lock to be in place.

Signed-off-by: Jens Axboe <[e-mail]>

block/blk-core.c

···
 		return NULL;
 	}
 
-	/*
-	 * if caller didn't supply a lock, they get per-queue locking with
-	 * our embedded lock
-	 */
-	if (!lock)
-		lock = &q->__queue_lock;
-
 	q->request_fn		= rfn;
 	q->prep_rq_fn		= NULL;
 	q->unplug_fn		= generic_unplug_device;

block/blk-settings.c

···
 	blk_set_default_limits(&q->limits);
 
 	/*
+	 * If the caller didn't supply a lock, fall back to our embedded
+	 * per-queue locks
+	 */
+	if (!q->queue_lock)
+		q->queue_lock = &q->__queue_lock;
+
+	/*
 	 * by default assume old behaviour and bounce for any highmem page
 	 */
 	blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);