workqueue: use mod_delayed_work() instead of __cancel + queue

Now that mod_delayed_work() is safe to call from IRQ handlers,
__cancel_delayed_work() followed by queue_delayed_work() can be
replaced with mod_delayed_work().

Most conversions are straight-forward except for the following.

* net/core/link_watch.c: linkwatch_schedule_work() was doing a quite
  elaborate dancing around its delayed_work.  Collapse it such that
  linkwatch_work is queued for immediate execution if LW_URGENT and
  existing timer is kept otherwise.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> 

2 files changed, 3 insertions, 10 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 4b4dbdfbca89..4b8b606dbb01 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -319,10 +319,8 @@ EXPORT_SYMBOL(__blk_run_queue);
  */
 void blk_run_queue_async(struct request_queue *q)
 {
-        if (likely(!blk_queue_stopped(q))) {
-                __cancel_delayed_work(&q->delay_work);
-                queue_delayed_work(kblockd_workqueue, &q->delay_work, 0);
-        }
+        if (likely(!blk_queue_stopped(q)))
+                mod_delayed_work(kblockd_workqueue, &q->delay_work, 0);
 }
 EXPORT_SYMBOL(blk_run_queue_async);
 
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 5a58e779912b..a9664fa0b609 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -929,12 +929,7 @@ throtl_schedule_delayed_work(struct throtl_data *td, unsigned long delay)
 
         /* schedule work if limits changed even if no bio is queued */
         if (total_nr_queued(td) || td->limits_changed) {
-                /*
-                 * We might have a work scheduled to be executed in future.
-                 * Cancel that and schedule a new one.
-                 */
-                __cancel_delayed_work(dwork);
-                queue_delayed_work(kthrotld_workqueue, dwork, delay);
+                mod_delayed_work(kthrotld_workqueue, dwork, delay);
                 throtl_log(td, "schedule work. delay=%lu jiffies=%lu",
                                 delay, jiffies);
         }