From: Jens Axboe <axboe@fb.com>
Date: Mon, 28 Dec 2015 20:01:22 +0000 (-0700)
Subject: block: add blk_start_queue_async()
X-Git-Tag: v4.4-rc8~6^2~2
X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=21491412f2ec6f13d4104de734dec0ba659d092e

block: add blk_start_queue_async()

We currently only have an inline/sync helper to restart a stopped
queue. If drivers need an async version, they have to roll their
own. Add a generic helper instead.

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

diff --git a/block/blk-core.c b/block/blk-core.c
index c487b94c59e3..33e2f62d5062 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -206,6 +206,22 @@ void blk_delay_queue(struct request_queue *q, unsigned long msecs)
 }
 EXPORT_SYMBOL(blk_delay_queue);
 
+/**
+ * blk_start_queue_async - asynchronously restart a previously stopped queue
+ * @q:    The &struct request_queue in question
+ *
+ * Description:
+ *   blk_start_queue_async() will clear the stop flag on the queue, and
+ *   ensure that the request_fn for the queue is run from an async
+ *   context.
+ **/
+void blk_start_queue_async(struct request_queue *q)
+{
+	queue_flag_clear(QUEUE_FLAG_STOPPED, q);
+	blk_run_queue_async(q);
+}
+EXPORT_SYMBOL(blk_start_queue_async);
+
 /**
  * blk_start_queue - restart a previously stopped queue
  * @q:    The &struct request_queue in question
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0169ba2e2e64..c70e3588a48c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -797,6 +797,7 @@ extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 extern int blk_queue_enter(struct request_queue *q, gfp_t gfp);
 extern void blk_queue_exit(struct request_queue *q);
 extern void blk_start_queue(struct request_queue *q);
+extern void blk_start_queue_async(struct request_queue *q);
 extern void blk_stop_queue(struct request_queue *q);
 extern void blk_sync_queue(struct request_queue *q);
 extern void __blk_stop_queue(struct request_queue *q);