From: Suparna Bhattacharya <suparna@in.ibm.com>

This patch appears to fix the hangs seen with AIO and 4G-4G for me.  It
ensures that the indirect versions of copy_xxx_user are used during aio
retries running in worker thread context (i.e.  access aio issuer's
user-space instead of kernel-space).


 fs/aio.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletion(-)

--- aio/fs/aio.c	2004-06-17 10:58:34.596512112 -0700
+++ 4g4g-aio-hang-fix/fs/aio.c	2004-06-17 12:29:35.380346784 -0700
@@ -795,18 +795,23 @@ static inline void aio_run_iocbs(struct 
  * aio_kick_handler:
  * 	Work queue handler triggered to process pending
  * 	retries on an ioctx. Takes on the aio issuer's
- * 	mm context before running the iocbs.
+ *	mm context before running the iocbs, so that
+ *	copy_xxx_user operates on the issuer's address
+ *      space.
  * Run on aiod's context.
  */
 static void aio_kick_handler(void *data)
 {
 	struct kioctx *ctx = data;
+	mm_segment_t oldfs = get_fs();
 
+	set_fs(USER_DS);
 	use_mm(ctx->mm);
 	spin_lock_irq(&ctx->ctx_lock);
 	__aio_run_iocbs(ctx);
  	unuse_mm(ctx->mm);
 	spin_unlock_irq(&ctx->ctx_lock);
+	set_fs(oldfs);
 }