From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner+willy=40w.ods.org-S1751954AbWG0TNe@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1751954AbWG0TNe (ORCPT <rfc822;willy@w.ods.org>);
	Thu, 27 Jul 2006 15:13:34 -0400
Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751958AbWG0TNe
	(ORCPT <rfc822;linux-kernel-outgoing>);
	Thu, 27 Jul 2006 15:13:34 -0400
Received: from pentafluge.infradead.org ([213.146.154.40]:10963 "EHLO
	pentafluge.infradead.org") by vger.kernel.org with ESMTP
	id S1751954AbWG0TNe (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Thu, 27 Jul 2006 15:13:34 -0400
Date: Thu, 27 Jul 2006 20:12:47 +0100
From: Christoph Hellwig <hch@infradead.org>
To: Eric Sandeen <sandeen@sandeen.net>
Cc: Neil Brown <neilb@suse.de>, Andrew Morton <akpm@osdl.org>,
       Theodore Tso <tytso@mit.edu>, jack@suse.cz, 20@madingley.org,
       marcel@holtmann.org, linux-kernel@vger.kernel.org, sct@redhat.com,
       adilger@clusterfs.com
Subject: Re: Bad ext3/nfs DoS bug
Message-ID: <20060727191247.GA29166@infradead.org>
Mail-Followup-To: Christoph Hellwig <hch@infradead.org>,
	Eric Sandeen <sandeen@sandeen.net>, Neil Brown <neilb@suse.de>,
	Andrew Morton <akpm@osdl.org>, Theodore Tso <tytso@mit.edu>,
	jack@suse.cz, 20@madingley.org, marcel@holtmann.org,
	linux-kernel@vger.kernel.org, sct@redhat.com, adilger@clusterfs.com
References: <17599.2754.962927.627515@cse.unsw.edu.au> <20060720160639.GF25111@atrey.karlin.mff.cuni.cz> <17600.30372.397971.955987@cse.unsw.edu.au> <20060721170627.4cbea27d.akpm@osdl.org> <20060722131759.GC7321@thunk.org> <20060724185604.9181714c.akpm@osdl.org> <17605.32781.909741.310735@cse.unsw.edu.au> <44C7A272.8030401@sandeen.net> <17608.96.409298.126686@cse.unsw.edu.au> <44C906CB.8050100@sandeen.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <44C906CB.8050100@sandeen.net>
User-Agent: Mutt/1.4.2.1i
X-SRS-Rewrite: SMTP reverse-path rewritten from <hch@infradead.org> by pentafluge.infradead.org
	See http://www.infradead.org/rpr.html
Sender: linux-kernel-owner@vger.kernel.org
X-Mailing-List: linux-kernel@vger.kernel.org

On Thu, Jul 27, 2006 at 01:32:43PM -0500, Eric Sandeen wrote:
> Neil Brown wrote:
> >On Wednesday July 26, sandeen@sandeen.net wrote:
> 
> >>Hm, with this, ext3.ko has a new dependency on exportfs.ko.  Is that 
> >>desirable/acceptable?
> >
> >Drat, you're right.
> >No, I don't think that is what we want.
> >I'll do it differently in a day or so.
> 
> Would moving export_iget into fs/inode.c & exporting it from there be a 
> reasonable way to go?  At least ext2 & ext3 both have this need (prevent 
> nfs access to special inodes) so putting the bulk of what they need for 
> get_dentry (i.e. export_iget) somewhere common seems like a decent 
> option to me.

Nope.  The right fix is to not make ext2/3 rely on export_iget at all. Please
implement the proper export_operations instead, similar to e.g. xfs. 

export_iget is a horrible layering violation that needs to go away long-term,
not move into core code.