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> 

1 files changed, 6 insertions, 15 deletions

diff --git a/net/core/link_watch.c b/net/core/link_watch.c
index c3519c6d1b16..8e397a69005a 100644
--- a/net/core/link_watch.c
+++ b/net/core/link_watch.c
@@ -120,22 +120,13 @@ static void linkwatch_schedule_work(int urgent)
 		delay = 0;
 
 	/*
-	 * This is true if we've scheduled it immeditately or if we don't
-	 * need an immediate execution and it's already pending.
+	 * If urgent, schedule immediate execution; otherwise, don't
+	 * override the existing timer.
 	 */
-	if (schedule_delayed_work(&linkwatch_work, delay) == !delay)
-		return;
-
-	/* Don't bother if there is nothing urgent. */
-	if (!test_bit(LW_URGENT, &linkwatch_flags))
-		return;
-
-	/* It's already running which is good enough. */
-	if (!__cancel_delayed_work(&linkwatch_work))
-		return;
-
-	/* Otherwise we reschedule it again for immediate execution. */
-	schedule_delayed_work(&linkwatch_work, 0);
+	if (test_bit(LW_URGENT, &linkwatch_flags))
+		mod_delayed_work(system_wq, &linkwatch_work, 0);
+	else
+		schedule_delayed_work(&linkwatch_work, delay);
 }