Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272561AbTHKMxr (ORCPT ); Mon, 11 Aug 2003 08:53:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272563AbTHKMxr (ORCPT ); Mon, 11 Aug 2003 08:53:47 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:26059 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S272561AbTHKMxp (ORCPT ); Mon, 11 Aug 2003 08:53:45 -0400 Message-ID: <3F3791C8.4090903@pobox.com> Date: Mon, 11 Aug 2003 08:53:28 -0400 From: Jeff Garzik Organization: none User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20021213 Debian/1.2.1-2.bunk X-Accept-Language: en MIME-Version: 1.0 To: Alex Tomas CC: linux-kernel@vger.kernel.org, ext2-devel@lists.sourceforge.net Subject: Re: [RFC] file extents for EXT3 References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1428 Lines: 39 Alex Tomas wrote: > hello all! > > there are several problems with old good method ext2/ext3 > use to store map of block for an inode. for example, ext3's > truncate is quite slow. I think extents could solve this > and some other troubles. so ... > > > in fact, design is taken from htree modern ext2/ext3 uses. in constrast with > htree, it isn't backward-compatible. Neat. I really like extents, and think this is the best long-term approach. Apparently the ext3 maintainers do, too, because tytso/sct's "ext roadmap" paper publishing a while ago describes extents, too. (I wish I had a URL for that) Anyway, something to keep in mind: Changing the underlying disk format without bumping the filesystem revision is a hugely bad idea. I disagreed with merging htree (even though its backward compat) without bumping the filesystem version, too. Vendors, distributors, OEMs, etc. all test against existing on-disk formats, when they release their products. When the filesystem format for an existing filesystem, in production, changes underneath them, they tend to get worried and annoyed. So, to all ext developers, Please add to ext4 not ext3! Jeff - 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/