workqueue: add to_delayed_work() helper function

It is a fairly common operation to have a pointer to a work and to need a
pointer to the delayed work it is contained in.  In particular, all
delayed works which want to rearm themselves will have to do that.  So it
would seem fair to offer a helper function for this operation.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 3cd51e579ab1..13e1adf55c4c 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -41,6 +41,11 @@ struct delayed_work {
 	struct timer_list timer;
 };
 
+static inline struct delayed_work *to_delayed_work(struct work_struct *work)
+{
+	return container_of(work, struct delayed_work, work);
+}
+
 struct execute_work {
 	struct work_struct work;
 };