Re: [PATCH 21/31] xfs: move the legacy xfs_attr_list to xfs_ioctl.c

[Dave Chinner <david@fromorbit.com>]

On Mon, Feb 17, 2020 at 01:59:47PM +0100, Christoph Hellwig wrote:
> The old xfs_attr_list code is only used by the attrlist by handle
> ioctl.  Move it to xfs_ioctl.c with its user.  Also move the
> attrlist and attrlist_ent structure to xfs_fs.h, as they are exposed
> user ABIs.  They are used through libattr headers with the same name
> by at least xfsdump.  Also document this relation so that it doesn't
> require a research project to figure out.

That's a bit nasty. I suspect that also needs documentation in the
path_to_handle(3) man page, too.

[...]

> +int
> +xfs_ioc_attr_list(
> +	struct xfs_inode		*dp,
> +	char				*buffer,
> +	int				bufsize,
> +	int				flags,
> +	struct attrlist_cursor_kern	*cursor)
> +{
> +	struct xfs_attr_list_context	context;
> +	struct xfs_attrlist		*alist;
> +	int				error;
> +
> +	/*
> +	 * Validate the cursor.
> +	 */
> +	if (cursor->pad1 || cursor->pad2)
> +		return -EINVAL;
> +	if ((cursor->initted == 0) &&
> +	    (cursor->hashval || cursor->blkno || cursor->offset))
> +		return -EINVAL;
> +
> +	/*
> +	 * Check for a properly aligned buffer.
> +	 */
> +	if (((long)buffer) & (sizeof(int)-1))
> +		return -EFAULT;
> +
> +	/*
> +	 * Initialize the output buffer.
> +	 */
> +	memset(&context, 0, sizeof(context));
> +	context.dp = dp;
> +	context.cursor = cursor;
> +	context.resynch = 1;
> +	context.flags = flags;
> +	context.buffer = buffer;
> +	context.bufsize = (bufsize & ~(sizeof(int)-1));  /* align */

ALIGN()?

Otherwise looks OK.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

-- 
Dave Chinner
david@fromorbit.com