[AIO] restore aio_default_wake function after aio_down succeeds

In order to ensure correct operation of future code in the iocb retry 
path, we need to restore the wait queue function to aio_wake_function 
before kick_iocb() triggers the retry path.

Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com>
diff -purN --exclude=description 51_aio_down_cancel_fix/fs/aio.c 52_aio_down_reset_wakefn/fs/aio.c
--- 51_aio_down_cancel_fix/fs/aio.c	2005-08-08 17:15:37.000000000 -0400
+++ 52_aio_down_reset_wakefn/fs/aio.c	2005-08-08 17:15:41.000000000 -0400
@@ -1475,8 +1475,7 @@ static ssize_t aio_setup_iocb(struct kio
  * because this callback isn't used for wait queues which
  * are nested inside ioctx lock (i.e. ctx->wait)
  */
-static int aio_wake_function(wait_queue_t *wait, unsigned mode,
-			     int sync, void *key)
+int aio_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
 {
 	struct kiocb *iocb = container_of(wait, struct kiocb, ki_wait);
 
diff -purN --exclude=description 51_aio_down_cancel_fix/include/linux/aio.h 52_aio_down_reset_wakefn/include/linux/aio.h
--- 51_aio_down_cancel_fix/include/linux/aio.h	2004-12-24 16:35:50.000000000 -0500
+++ 52_aio_down_reset_wakefn/include/linux/aio.h	2005-08-08 17:15:41.000000000 -0400
@@ -154,6 +154,7 @@ struct kioctx {
 /* prototypes */
 extern unsigned aio_max_size;
 
+extern int aio_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
 extern ssize_t FASTCALL(wait_on_sync_kiocb(struct kiocb *iocb));
 extern int FASTCALL(aio_put_req(struct kiocb *iocb));
 extern void FASTCALL(kick_iocb(struct kiocb *iocb));
diff -purN --exclude=description 51_aio_down_cancel_fix/lib/semaphore-sleepers.c 52_aio_down_reset_wakefn/lib/semaphore-sleepers.c
--- 51_aio_down_cancel_fix/lib/semaphore-sleepers.c	2005-08-12 12:44:31.000000000 -0400
+++ 52_aio_down_reset_wakefn/lib/semaphore-sleepers.c	2005-08-16 15:43:24.000000000 -0400
@@ -16,6 +16,7 @@
 #include <linux/sched.h>
 #include <linux/err.h>
 #include <linux/init.h>
+#include <linux/aio.h>
 #include <asm/semaphore.h>
 
 /*
@@ -103,6 +104,7 @@ static int aio_down_wait(wait_queue_t *w
 	 * the wait_queue_head.
 	 */
 	if (!atomic_add_negative(sleepers - 1, &sem->count)) {
+		iocb->ki_wait.func = aio_wake_function;
 		iocb->ki_cancel = NULL;
 		sem->sleepers = 0;
 		sem->aio_owner = iocb;