Re: [PATCH] Add ENOSYS into sys_io_cancel

[Benjamin LaHaise <bcrl@kvack.org>]

Hello Wendy,

Two things: your patch needs to be properly signed off on.  Read 
Documentation/SubmittingPatches for a description of what that entials.  
Secondly, your patch adds whitespace on the end of the else.  Aside 
from that, the printk should be removed -- just replace it with the 
ret = -ENOSYS.

Also, please cc linux-aio@kvack.org on future aio patches.  Cheers,

		-ben 

On Mon, Jul 11, 2005 at 03:06:52PM -0400, Wendy Cheng wrote:
> Previously sent via private mail that doesn't seem to go thru - resend 
> via office mailer.
> 
> 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.
> 
> -- Wendy
> 
> 

> --- linux-2.6.12/fs/aio.c	2005-06-17 15:48:29.000000000 -0400
> +++ linux/fs/aio.c	2005-07-10 12:48:14.000000000 -0400
> @@ -1641,8 +1641,9 @@ asmlinkage long sys_io_cancel(aio_contex
>  		cancel = kiocb->ki_cancel;
>  		kiocb->ki_users ++;
>  		kiocbSetCancelled(kiocb);
> -	} else
> +	} else 
>  		cancel = NULL;
> +	 
>  	spin_unlock_irq(&ctx->ctx_lock);
>  
>  	if (NULL != cancel) {
> @@ -1659,8 +1660,10 @@ asmlinkage long sys_io_cancel(aio_contex
>  			if (copy_to_user(result, &tmp, sizeof(tmp)))
>  				ret = -EFAULT;
>  		}
> -	} else
> +	} else {
> +		ret = -ENOSYS;
>  		printk(KERN_DEBUG "iocb has no cancel operation\n");
> +	} 
>  
>  	put_ioctx(ctx);
>  


-- 
"Time is what keeps everything from happening all at once." -- John Wheeler