From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Sandeen Subject: extent counting fun Date: Mon, 05 Jul 2010 14:24:52 -0500 Message-ID: <4C323184.8020401@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: ext4 development Return-path: Received: from mx1.redhat.com ([209.132.183.28]:64116 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754590Ab0GETY4 (ORCPT ); Mon, 5 Jul 2010 15:24:56 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o65JOuJg024447 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 5 Jul 2010 15:24:56 -0400 Received: from liberator.sandeen.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o65JOrWd017541 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 5 Jul 2010 15:24:56 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: [root@host ~]# filefrag -B /mnt/test/file /mnt/test/file: 34 extents found [root@host ~]# filefrag /mnt/test/file /mnt/test/file: 1058 extents found, perfection would be 1 extent Hum, is it 34 or 1058? :) Older filefrag counted contiguous metadata as part of a contiguous extent... newer filefrag works in fiemap query-only mode by default, and just takes what fiemap tells it. The inconsistency is weird though, and led to a Red Hat bug that I'm inclined to NOTABUG... but do people think this needs to be made any more consistent? Should we hack ext3_fiemap() to include the checks for contiguous metadata? Or was that too shady/clever to start with ...? :) -Eric