block: add a queue_limits_set helper

Add a small wrapper around queue_limits_commit_update for stacking
drivers that don't want to update existing limits, but set an
entirely new set.

Signed-off-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

block/blk-settings.c

@@ -266,6 +266,24 @@ int queue_limits_commit_update(struct request_queue *q,
 }
 EXPORT_SYMBOL_GPL(queue_limits_commit_update);
 
+/**
+ * queue_limits_commit_set - apply queue limits to queue
+ * @q:		queue to update
+ * @lim:	limits to apply
+ *
+ * Apply the limits in @lim that were freshly initialized to @q.
+ * To update existing limits use queue_limits_start_update() and
+ * queue_limits_commit_update() instead.
+ *
+ * Returns 0 if successful, else a negative error code.
+ */
+int queue_limits_set(struct request_queue *q, struct queue_limits *lim)
+{
+	mutex_lock(&q->limits_lock);
+	return queue_limits_commit_update(q, lim);
+}
+EXPORT_SYMBOL_GPL(queue_limits_set);
+
 /**
  * blk_queue_bounce_limit - set bounce buffer limit for queue
  * @q: the request queue for the device

include/linux/blkdev.h

@@ -889,6 +889,7 @@ queue_limits_start_update(struct request_queue *q)
 }
 int queue_limits_commit_update(struct request_queue *q,
 		struct queue_limits *lim);
+int queue_limits_set(struct request_queue *q, struct queue_limits *lim);
 
 /*
  * Access functions for manipulating queue properties