From mboxrd@z Thu Jan  1 00:00:00 1970
From: Shaya Potter <spotter@cs.columbia.edu>
Subject: Re: [PATCH 01/24] Unionfs: Documentation
Date: Mon, 08 Jan 2007 16:30:48 -0500
Message-ID: <1168291848.9853.1.camel@localhost.localdomain>
References: <1168229596580-git-send-email-jsipek@cs.sunysb.edu>
	 <1168229596875-git-send-email-jsipek@cs.sunysb.edu>
	 <20070108111852.ee156a90.akpm@osdl.org>
	 <Pine.LNX.4.63.0701081442230.19059@razor.cs.columbia.edu>
	 <20070108131957.cbaf6736.akpm@osdl.org>
Mime-Version: 1.0
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
Cc: "Josef 'Jeff' Sipek" <jsipek@cs.sunysb.edu>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	hch@infradead.org, viro@ftp.linux.org.uk, torvalds@osdl.org,
	mhalcrow@us.ibm.com, David Quigley <dquigley@fsl.cs.sunysb.edu>,
	Erez Zadok <ezk@cs.sunysb.edu>
Return-path: <linux-fsdevel-owner@vger.kernel.org>
Received: from cs.columbia.edu ([128.59.16.20]:39759 "EHLO cs.columbia.edu"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S932152AbXAHVkT (ORCPT <rfc822;linux-fsdevel@vger.kernel.org>);
	Mon, 8 Jan 2007 16:40:19 -0500
To: Andrew Morton <akpm@osdl.org>
In-Reply-To: <20070108131957.cbaf6736.akpm@osdl.org>
Sender: linux-fsdevel-owner@vger.kernel.org
List-Id: linux-fsdevel.vger.kernel.org

On Mon, 2007-01-08 at 13:19 -0800, Andrew Morton wrote:
> On Mon, 8 Jan 2007 14:43:39 -0500 (EST) Shaya Potter <spotter@cs.columbia.edu> wrote:
> >  It's the same thing as modifying a block 
> > device while a file system is using it.  Now, when unionfs gets confused, 
> > it shouldn't oops, but would one expect ext3 to allow one to modify its 
> > backing store while its using it?
> 
> There's no such problem with bind mounts.  It's surprising to see such a
> restriction with union mounts.

the difference is bind mounts are a vfs construct, while unionfs is a
file system.