From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [Ext2-devel] [RFC 0/13] extents and 48bit ext3 Date: Fri, 09 Jun 2006 17:47:23 -0400 Message-ID: <4489EC6B.4010200@garzik.org> References: <1149816055.4066.60.camel@dyn9047017069.beaverton.ibm.com> <4488E1A4.20305@garzik.org> <20060609083523.GQ5964@schatzie.adilger.int> <44898EE3.6080903@garzik.org> <448992EB.5070405@garzik.org> <448997FA.50109@garzik.org> <44899A1C.7000207@garzik.org> <1149886363.5776.109.camel@sisko.sctweedie.blueyonder.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Alex Tomas , Andrew Morton , "ext2-devel@lists.sourceforge.net" , linux-kernel , Linus Torvalds , Mingming Cao , linux-fsdevel@vger.kernel.org, Andreas Dilger Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:8614 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S1030533AbWFIVrc (ORCPT ); Fri, 9 Jun 2006 17:47:32 -0400 To: "Stephen C. Tweedie" In-Reply-To: <1149886363.5776.109.camel@sisko.sctweedie.blueyonder.co.uk> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Stephen C. Tweedie wrote: > Hi, > > On Fri, 2006-06-09 at 11:56 -0400, Jeff Garzik wrote: > >> Think about how this will be deployed in production, long term. >> >> If extents are not made default at some point, then no one will use the >> feature, and it should not be merged. > > Features such as ACLs and SELinux are still not on by default and are > most *definitely* used. This is a bogus argument. They are on in SElinux-enabled distro installs, AFAIK? >> And when extents are default, you have this blizzard-of-feature-flags >> stealth upgrade event occur _sometime_ after they boot into the new fs >> for the first time. > > No. I don't see it ever being forced on in the kernel by default, so > there will be no such "stealth upgrades". > > Rather, if it is "made default", that will be done by setting the flag > by default on newly-created filesystems in mke2fs. We won't be playing > magic on existing filesystems. > > And to avoid confusion, I am *entirely* open to the idea of making it > only ever default to on in mke2fs at some point in the future where we > batch a set of incompat features with the "ext4" label, so that "mke2fs > -O ext4", or "mke4fs", would set it. That has already been proposed on > ext2-devel; we're nowhere near the stage of making that default yet. Sure. And why not bundle that with a vehicle for separating out the _code_ that deals with ancient formats versus newer formats. A vehicle that enables the existing ext3 stuff to stabilize and freeze, while enabling parallel development of new features. Jeff