From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269505AbUHZT15 (ORCPT ); Thu, 26 Aug 2004 15:27:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269504AbUHZT1z (ORCPT ); Thu, 26 Aug 2004 15:27:55 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:30640 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S269499AbUHZT0r (ORCPT ); Thu, 26 Aug 2004 15:26:47 -0400 Subject: Re: silent semantic changes with reiser4 From: Lee Revell To: Hans Reiser Cc: Andrew Morton , hch@lst.de, linux-fsdevel@vger.kernel.org, linux-kernel , flx@namesys.com, torvalds@osdl.org, reiserfs-list@namesys.com In-Reply-To: <412DAC59.4010508@namesys.com> References: <20040824202521.GA26705@lst.de> <412CEE38.1080707@namesys.com> <20040825152805.45a1ce64.akpm@osdl.org> <412D9FE6.9050307@namesys.com> <20040826014542.4bfe7cc3.akpm@osdl.org> <412DAC59.4010508@namesys.com> Content-Type: text/plain Message-Id: <1093548414.5678.74.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Thu, 26 Aug 2004 15:26:55 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2004-08-26 at 05:24, Hans Reiser wrote: > Andrew Morton wrote: > > > >And describe the "plugin" system. Why does the filesystem need such a > >thing (other filesystems get their features via `patch -p1')? > > > > > It takes 6 months or more to become competent to change a usual > filesystem. Creating a new reiser4 plugin is a weekend programmer fun > hack to do. Weekend programmers matter, because they tend to have > clever ideas based on understanding a need they have. How many people > can easily add new features to ext3 or reiserfs V3? Very few. > > What happens if you need a disk format change? > > Well, in V4, you can easily compose a plugin from plugin methods of > other plugins, write a little piece of code with the one thing you want > different, and add it in. Disk format changes, no big deal, add a new > disk format plugin, or a new item plugin, or a new node plugin, etc., > and you got your new format. > OK, real world example. My roommate has an AKAI MPC-2000, a very popular hardware sampler from the 90's. The disk format is known,there are a few utilities to edit the disks on a PC and extract the PCM samples, but there are no tools to mount it on a modern PC. Are you saying that, since I know the MPC disk format, I could write a reiser4 plugin to mount an MPC drive? If so, then Hans has an excellent point. Users do want this kind of thing, and it is worth having to fix tar et al. Lee