From: tytso@mit.edu Subject: Re: [PATCH,RFC] Adding quotacheck functionality to e2fsck Date: Thu, 25 Mar 2010 23:38:24 -0400 Message-ID: <20100326033824.GC21658@thunk.org> References: <20100326004738.GJ3145@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org To: Jan Kara Return-path: Received: from THUNK.ORG ([69.25.196.29]:35364 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753913Ab0CZDkq (ORCPT ); Thu, 25 Mar 2010 23:40:46 -0400 Content-Disposition: inline In-Reply-To: <20100326004738.GJ3145@quack.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Mar 26, 2010 at 01:47:38AM +0100, Jan Kara wrote: > This is definitely a move in the right direction. I'd be even happier > if e2fsck would write quota file directly - then we could just make > quota files hidden inodes, start doing quota accounting immediately > on mount and always do quota journaling. That would save us quite some > trouble in kernel. The only problem with this is that we'd need to pull > knowledge about quota formats in e2fsck... Yes, quite possibly. How quota is currently is set up is quite kludgy, with magic options that do nothing but display magic options in /proc/mounts, just in case that's a hard link to /etc/mtab. It also looks like that some of the magic is in various distribution's init.d scripts, and so while I very much want to clean things up, it wasn't clear to me how much flexibility we would have without worrying about breaking the init scripts for Debian, Ubuntu, RHEL, SLES, Fedora, Open SuSE, etc. There may also be other programs that depend on the existence of aquota.user, and may be reading and writing them in various random ways, and there is the question of how do we provide compatibility with these other programs, some of which may not be within quotatools, but in various magic virtualization or container or cluster management systems.... So maintaining compatibility between older kernels, newer kernels, older init scripts, new init scripts, etc. may make changing the quota system quite difficult. I would like to do as much cleanup as we can, though. One question I have --- do we really have to support the 2 or 3 different quota variants? How many people/distributions are still using the original old quota system? One thing that worries me is that it looks like the old (non-journaled) quota system may be the primary system still being used by Canonical and Debian... I really do hope I'm wrong, but there are a bunch of HOWTO's that still people to use usrquota and grpquota in /etc/fstab, and not the newer usrjquota and grpjquota mount options. - Ted