Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422734AbXAHUtf (ORCPT ); Mon, 8 Jan 2007 15:49:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422745AbXAHUte (ORCPT ); Mon, 8 Jan 2007 15:49:34 -0500 Received: from tmailer.gwdg.de ([134.76.10.23]:55177 "EHLO tmailer.gwdg.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422734AbXAHUtd (ORCPT ); Mon, 8 Jan 2007 15:49:33 -0500 Date: Mon, 8 Jan 2007 21:24:57 +0100 (MET) From: Jan Engelhardt To: Shaya Potter cc: Andrew Morton , "Josef 'Jeff' Sipek" , 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 , Erez Zadok Subject: Re: [PATCH 01/24] Unionfs: Documentation In-Reply-To: Message-ID: References: <1168229596580-git-send-email-jsipek@cs.sunysb.edu> <1168229596875-git-send-email-jsipek@cs.sunysb.edu> <20070108111852.ee156a90.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Report: Content analysis: 0.0 points, 6.0 required _SUMMARY_ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1341 Lines: 35 On Jan 8 2007 14:43, Shaya Potter wrote: > On Mon, 8 Jan 2007, Andrew Morton wrote: >> On Sun, 7 Jan 2007 23:12:53 -0500 >> "Josef 'Jeff' Sipek" wrote: >> >> > +Modifying a Unionfs branch directly, while the union is >> > +mounted, is currently unsupported. >> >> Does this mean that if I have /a/b/ and /c/d/ unionised under >> /mnt/union, I am not allowed to alter anything under /a/b/ >> and /c/d/? That I may only alter stuff under /mnt/union? >> >> If so, that sounds like a significant limitation. > > haven't we been through this? 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? (Blunt counter-example: Modifying the underlying filesystem of an NFS import does not break. But I agree with Shaya.) Well it was suggested to make /a/b and /c/d read-only while the union is mounted, using a ro bind mount, what about it? (To catch unwanted tampering with the lowlevels) -`J' -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/