From: Eric Sandeen Subject: Re: [PATCH v2] xfstests: add support for ext4dev FSTYP Date: Thu, 02 Jun 2011 22:26:05 -0500 Message-ID: <4DE8544D.30800@redhat.com> References: <1306933012-8666-1-git-send-email-amir73il@users.sourceforge.net> <20110601232804.GL32466@dastard> <4DE7A557.9040608@redhat.com> <7D3F86FA-5AA9-49B0-9AFE-F597E83C07B4@dilger.ca> <20110603003610.GD16306@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Andreas Dilger , "Amir G." , Dave Chinner , xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, sergey57@gmail.com, Amir Goldstein To: "Ted Ts'o" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:60430 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751701Ab1FCD0Z (ORCPT ); Thu, 2 Jun 2011 23:26:25 -0400 In-Reply-To: <20110603003610.GD16306@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 6/2/11 7:36 PM, Ted Ts'o wrote: > On Thu, Jun 02, 2011 at 11:22:53AM -0600, Andreas Dilger wrote: >> On 2011-06-02, at 8:59 AM, Eric Sandeen wrote: >>> I don't really mind adding ext4dev to FSTYP case statements, it >>> -is- something which blkid could, in theory, still return, and >>> making xfstests cope with that and try to invoke fsck -t ext4dev >>> doesn't bother me too much. It is sadly an fs type embedded into >>> a few tools. >> >> I'm perfectly OK with using ext4dev as a filesystem type that allows testing >> changes to ext4 on a system that is already running ext4 as the root fs. > > My take on this is that way too much time has been spent this subject. > Being able to use ext4dev is useful, and given that we have all of > this support in our existing system tools, why not use it to make ext4 > development more efficient/easy? As a bonus you can build the ext4dev > as a module, and that means you the compile/edit/debug cycle can be > much faster since you can avoid doing a reboot, for those > circumstances where using KVM is not possible/convenient. Personally, > I normally use KVM these days, but I can imagine situations where > using ext4dev would be a better way to go. For example, I'd probably > use KVM on my laptop, but for testing on production servers in a data > center, I'd probably use ext4dev, for a variety of local deployment > considerations that's not worth going into here. > > That being said, whether or not we modify xfstests seems to be a moot > point. In order for me to do my bigalloc development, I've been > patching common.rc so that "/sbin/mkfs.$FSTYP" --> "mkfs.$FSTYP" and > "/sbin/fsck -t $FSTYP" --> "fsck.$FSTYP". It's a 3 line change. Not > a big deal. I've been making this change using /bin/ed after > installing xfstests. So if the XFS folks want to veto this change --- > who cares? It's not hard to make the change locally in order to make > xfstests. > > On the other hand, given that xfstests is using "mkfs.$FSTYP", I don't > see why it's so important that it clings to "fsck -t $FSTYP" instead > of using "fsck.$FSTYP". There's no real benefit to calling the fsck > driver; it's just an extra fork and exec, and xfstests is being > inconsistent by insisting on the use of the fsck driver, but not using > the mkfs driver. > > But that being said, hacking xfstests is not hard, and if Dave and/or > Eric feels strongly about resisting this change, it's not worth a lot > of time, one way or another.... I think we just want to make sure we understand the reasons for a change. Every change has risks, and xfstests is used on a lot of different systems. If I don't fully understand the motivation for a change, I ask questions. All part of a careful review. And I apologize for the mkfs vs. fsck inconsistency, that was probably my fault, originally ;) -Eric > - Ted