Re: Generic infrastructure for acls

[Andrew Morton <akpm@osdl.org>]

On Sat, 02 Sep 2006 00:14:22 +0200
Andreas Gruenbacher <agruen@suse.de> wrote:

> +generic_acl_list(struct inode *inode, struct generic_acl_operations *ops,
> +		 int type, char *list, size_t list_size)
> +{
> +	struct posix_acl *acl;
> +	const char *name;
> +	size_t size;
> +
> +	acl = ops->getacl(inode, type);
> +	if (!acl)
> +		return 0;
> +	posix_acl_release(acl);
> +
> +	switch(type) {
> +		case ACL_TYPE_ACCESS:
> +			name = POSIX_ACL_XATTR_ACCESS;
> +			break;
> +
> +		case ACL_TYPE_DEFAULT:
> +			name = POSIX_ACL_XATTR_DEFAULT;
> +			break;
> +
> +		default:
> +			return 0;
> +	}
> +	size = strlen(name) + 1;
> +	if (list && size <= list_size)
> +		memcpy(list, name, size);
> +	return size;
> +}

That's a clumsy-looking interface.  How is the caller to know that *list
got filled in?  By checking the generic_acl_list() return value against
`list_size'?

If so, shouldn't this be covered in the API description (when you write
it ;))?

Or should it be returning some error code in this case?

Or should we just strdup() the thing?

Or return `name' and let the caller worry about it?

-- 
VGER BF report: H 1.83187e-15