From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Dilger Subject: Re: [Ext2-devel] [RFC 0/13] extents and 48bit ext3 Date: Fri, 9 Jun 2006 17:21:08 -0600 Message-ID: <20060609232108.GM5964@schatzie.adilger.int> References: <20060609091327.GA3679@infradead.org> <44898476.80401@garzik.org> <4489874C.1020108@garzik.org> <44899113.3070509@garzik.org> <170fa0d20606090921x71719ad3m7f9387ba15413b8f@mail.gmail.com> <200606092252.k59Mqc2Q018613@turing-police.cc.vt.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alex Tomas , Jeff Garzik , ext2-devel , linux-kernel@vger.kernel.org, Christoph Hellwig , Mingming Cao , linux-fsdevel@vger.kernel.org Return-path: Received: from mail.clusterfs.com ([206.168.112.78]:22420 "EHLO mail.clusterfs.com") by vger.kernel.org with ESMTP id S1030301AbWFIXVC (ORCPT ); Fri, 9 Jun 2006 19:21:02 -0400 To: Valdis.Kletnieks@vt.edu Content-Disposition: inline In-Reply-To: <200606092252.k59Mqc2Q018613@turing-police.cc.vt.edu> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Jun 09, 2006 18:52 -0400, Valdis.Kletnieks@vt.edu wrote: > On Fri, 09 Jun 2006 20:33:18 +0400, Alex Tomas said: > > one who needs/wants to go back may get rid of extents by: > > a) remounting w/o extents option > > b) copying new-fashion-style files so that copies use blockmap > > c) dropping extents feature in superblock > > OK.. Obviously my brain is tiny and easily overfilled. ... > Given that the whole alledged problem with extents is that they're not > backward compatible, how do you read the files in (b) so that you can copy > them, if the data is in the non-compatible extents that you can't read because > you've disabled extents? You mount with the new kernel without "-o extents", and find files with extents "lsattr -R /mnt/tmp | awk '/----e / print { $2 }'", copy those files, mv over old files, unmount. A similar thing is necessary for ext3 filesystems before you can mount them as ext2 - they can't be mounted as ext2 until the journal is recovered (an unrecovered journal is an incompatible feature). Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc.