block: add API for delaying work/request_fn a little bit

Currently we use plugging for that, but as plugging is going away,
we need an alternative mechanism.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e3ee74fc5903..f55b2a8b6610 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -300,6 +300,11 @@ struct request_queue
         unsigned long           unplug_delay;   /* After this many jiffies */
         struct work_struct      unplug_work;
 
+        /*
+         * Delayed queue handling
+         */
+        struct delayed_work     delay_work;
+
         struct backing_dev_info backing_dev_info;
 
         /*
@@ -677,6 +682,7 @@ extern int blk_insert_cloned_request(struct request_queue *q,
 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_delay_queue(struct request_queue *, unsigned long);
 extern void blk_recount_segments(struct request_queue *, struct bio *);
 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
                           unsigned int, void __user *);