Re: [PATCH] Add ENOSYS into sys_io_cancel

[Wendy Cheng <wcheng@redhat.com>]

Benjamin LaHaise wrote:

> Also, please cc linux-aio@kvack.org on future aio patches.  
>  
Didn't realize the patch was sent to linux-kernel (that I don't 
subscribe) instead of linux-aio - revised patch attached. Thanks for the 
help .... Wendy

> On Mon, Jul 11, 2005 at 03:06:52PM -0400, Wendy Cheng wrote:
>
> Note that other than few exceptions, most of the current filesystem 
> and/or drivers do not have aio cancel specifically defined 
> (kiob->ki_cancel field is mostly NULL). However, sys_io_cancel system 
> call universally sets return code to -EGAIN. This gives applications a 
> wrong impression that this call is implemented but just never works. We 
> have customer inquires about this issue.
>
> Upload a trivial patch to address this confusion.
>
>  

Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>

--- linux-2.6.12/fs/aio.c	2005-06-17 15:48:29.000000000 -0400
+++ linux/fs/aio.c	2005-07-12 11:26:08.503256160 -0400
@@ -1660,7 +1660,7 @@ asmlinkage long sys_io_cancel(aio_contex
 				ret = -EFAULT;
 		}
 	} else
-		printk(KERN_DEBUG "iocb has no cancel operation\n");
+		ret = -ENOSYS;
 
 	put_ioctx(ctx);