Re: [PATCH 3/7] revoke: core code

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

On Fri, 9 Mar 2007 10:15:15 +0200 (EET)
Pekka J Enberg <penberg@cs.helsinki.fi> wrote:

> From: Pekka Enberg <penberg@cs.helsinki.fi>
> 
> The revokeat(2) and frevoke(2) system calls invalidate open file
> descriptors and shared mappings of an inode. After an successful
> revocation, operations on file descriptors fail with the EBADF or
> ENXIO error code for regular and device files,
> respectively. Attempting to read from or write to a revoked mapping
> causes SIGBUS.

Acked-by: Alan Cox <alan@redhat.com>


> +static ssize_t revoked_file_aio_read(struct kiocb *iocb,
> +				     const struct iovec *iov,
> +				     unsigned long nr_segs, loff_t pos)
> +{
> +	return -EBADF;
> +}

Do we need both -EBADF and -EXNIO versions. It is hard to tell from
existing OS's as they don't support revoke of files just special files ?

> +static ssize_t revoked_special_file_read(struct file *filp, char __user * buf,
> +					 size_t size, loff_t * ppos)
> +{
> +	return -ENXIO;
> +}

Bezerkly Unix returns 0 for the special file read case