block: add a blk_plug_device_unlocked() that grabs the queue lock
blk_plug_device() must be called with the queue lock held, so callers
often just grab and release the lock for that purpose. Add a helper
that does just that.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/blk-core.c b/block/blk-core.c
index fef79cc..4889eb8 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -212,6 +212,24 @@
}
EXPORT_SYMBOL(blk_plug_device);
+/**
+ * blk_plug_device_unlocked - plug a device without queue lock held
+ * @q: The &struct request_queue to plug
+ *
+ * Description:
+ * Like @blk_plug_device(), but grabs the queue lock and disables
+ * interrupts.
+ **/
+void blk_plug_device_unlocked(struct request_queue *q)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ blk_plug_device(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+}
+EXPORT_SYMBOL(blk_plug_device_unlocked);
+
/*
* remove the queue from the plugged list, if present. called with
* queue lock held and interrupts disabled.
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 88d6808..e61f22b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -655,6 +655,7 @@
extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
extern void blk_requeue_request(struct request_queue *, struct request *);
extern void blk_plug_device(struct request_queue *);
+extern void blk_plug_device_unlocked(struct request_queue *);
extern int blk_remove_plug(struct request_queue *);
extern void blk_recount_segments(struct request_queue *, struct bio *);
extern int scsi_cmd_ioctl(struct file *, struct request_queue *,
