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, 1 insertions, 2 deletions

diff --git a/mm/slab.c b/mm/slab.c
index 825c606f691d..208323fd37bc 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3992,8 +3992,7 @@ static void cache_reap(struct work_struct *w)
         struct kmem_cache *searchp;
         struct kmem_list3 *l3;
         int node = numa_node_id();
-        struct delayed_work *work =
-                container_of(w, struct delayed_work, work);
+        struct delayed_work *work = to_delayed_work(w);
 
         if (!mutex_trylock(&cache_chain_mutex))
                 /* Give up. Setup the next iteration. */