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 <jens.axboe@oracle.com>

block/blk-core.c

@@ -575,13 +575,6 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
 		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

@@ -164,6 +164,13 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
 
 	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
 	 */