[AIO] fix iocb run deadlock introduced in lock_kiocb

Calling __aio_run_iocbs can result in a deadlock if an iocb on the run 
list has its lock held by the caller.  Fix this by only running the iocb 
list *after* having run and unlocked the iocb just submitted.

Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com>
diff -purN --exclude=description 815_dont_unlock/fs/aio.c 816_iocb_run_deadlock/fs/aio.c
--- 815_dont_unlock/fs/aio.c	2005-08-15 15:34:25.000000000 -0400
+++ 816_iocb_run_deadlock/fs/aio.c	2005-08-17 13:46:21.000000000 -0400
@@ -1558,17 +1558,15 @@ int fastcall io_submit_one(struct kioctx
 		goto out_put_req;
 
 	spin_lock_irq(&ctx->ctx_lock);
-	if (likely(list_empty(&ctx->run_list))) {
-		aio_run_iocb(req);
-	} else {
-		list_add_tail(&req->ki_run_list, &ctx->run_list);
+	aio_run_iocb(req);
+	if (!kiocbIsDontUnlock(req))
+		unlock_kiocb(req);
+	if (!list_empty(&ctx->run_list)) {
 		/* drain the run list */
 		while (__aio_run_iocbs(ctx))
 			;
 	}
 	spin_unlock_irq(&ctx->ctx_lock);
-	if (!kiocbIsDontUnlock(req))
-		unlock_kiocb(req);
 	aio_put_req(req);	/* drop extra ref to req */
 	return 0;