From: Karel Zak Subject: Re: [PATCH] obsolete libcom-err for SuSE e2fsprogs Date: Tue, 25 Sep 2007 22:57:23 +0200 Message-ID: <20070925205723.GG2806@petra.dvoda.cz> References: <46F1CFC0.3070801@redhat.com> <20070920050923.GX32520@schatzie.adilger.int> <46F2D678.4060203@redhat.com> <20070920215427.GL30221@thunk.org> <20070924092539.GC2819@petra.dvoda.cz> <20070924124035.GA4209@thunk.org> <20070925091400.GA2806@petra.dvoda.cz> <1190715083.3373.79.camel@lov.localdomain> <20070925123454.GE2806@petra.dvoda.cz> <1190751950.3773.23.camel@lov.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Theodore Tso , Eric Sandeen , Andreas Dilger , linux-ext4@vger.kernel.org, List util-linux-ng To: Kay Sievers Return-path: Received: from mx1.redhat.com ([66.187.233.31]:40417 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754557AbXIYU5b (ORCPT ); Tue, 25 Sep 2007 16:57:31 -0400 Content-Disposition: inline In-Reply-To: <1190751950.3773.23.camel@lov.localdomain> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Tue, Sep 25, 2007 at 10:25:50PM +0200, Kay Sievers wrote: > On Tue, 2007-09-25 at 14:34 +0200, Karel Zak wrote: > > On Tue, Sep 25, 2007 at 12:11:23PM +0200, Kay Sievers wrote: > > > On Tue, 2007-09-25 at 11:14 +0200, Karel Zak wrote: > > > > Now we duplicate a lot of FS probe code in libblkid, libvolume_id and > > > > libdisk. > > > > > > > > Yes, it's long-term task, but it's good direction (IMHO). > > > > > > It is, and we are not providing a real value to the users by providing > > > both of these libs at the same time. :) > > > > > > But udev has a very different requirement for probing filesystems. > > > Unlike non-udev systems, we can't accept any hidden policy inside a > > > library. We just want to pass a byte stream to the lib, and get back > > > what exactly is in _this_ byte stream. There must be no chaching, no > > > devmapper logic, no stat()'ing in /dev, no reading of /proc/partitions, > > > no ioctl()'s, no hidden decisions, nothing. None of these actions is > > > acceptable to be done by the library itself, if udev is used. We need > > > pure mechanics, no policy. We also need an API that allows to specify > > > the size of the stream and the probing offset. And we don't want to > > > iterate over tags, need the filesystem version information, the raid > > > metadata probing, and the classification volume_id provides. > > > > Technical details :-) > > What do you miss, these are all technical details. :) In simple words, > we need a completely policy-free, not try-to-be-smart in any sense set > of functions to identify a bytestream by magic bytes. Yes, I've read libvolume_id code and I good understand what you mean. > > Cool. I'd like to create libfsprobe as an independent project. Or is > > there any advantage to merge everything to util-linux-ng? I don't > > think so. > > Hmm, only if you reaqlly don't want to pull it in util-linux, we could > have it as a separate tree. I still think util-linux is the best place, > because the most important user of it is mount/fsck. It's your call, I > would have no problem sending patches against util-linux. :) OK, Ted has same opinion and I'm not so stubborn... Let's use util-linux-ng. (I think we can continue with this topic at util-linux-ng mailing list only.) Karel -- Karel Zak