From: Eric Sandeen Subject: Re: delalloc fragmenting files? Date: Mon, 05 Nov 2007 12:54:34 -0600 Message-ID: <472F66EA.9080908@redhat.com> References: <47225B1E.2060708@redhat.com> <20071026221938.GV3042@webber.adilger.int> <4728ED3B.1060407@redhat.com> <47291F62.3000008@gmail.com> <4729EEB2.9090406@redhat.com> <472A2384.2010001@redhat.com> <472AE644.1040102@gmail.com> <472B453F.8010608@redhat.com> <472E1114.7060206@gmail.com> <472F54EE.9030904@redhat.com> <20071105185133.GA3900@webber.adilger.int> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: Eric Sandeen , Alex Tomas , ext4 development , Kalpak Shah Return-path: Received: from mx1.redhat.com ([66.187.233.31]:40747 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753263AbXKESyk (ORCPT ); Mon, 5 Nov 2007 13:54:40 -0500 In-Reply-To: <20071105185133.GA3900@webber.adilger.int> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Andreas Dilger wrote: > On a related note - the FIEMAP patches to filefrag also include a new > output format that is much more useful, IMHO. The new format is like: > > {filename} > ext: [logical start.. end kB]: phys start..end kB : kB:lun: flags > 0: [ 0.. 30207]: 401416.. 522251: 120828: 0 : > 1: [ 30208.. 60927]: 532480.. 655359: 122880: 0 : > 2: [ 60928.. 121855]: 790536.. 916484: 125948: 0 : > > Hopefully Kalpak will be able to post the updated patches here soon. yep, I hacked existing filefrag to do something like this, the existing format is pretty hard to glance over :) One thing I like about xfs_bmap is that it can tell you which Allocation Group the blocks are in; most filesystems have some concept of sub-regions of the filesystem, such as BGs or resource groups or whatnot - do you think there is room for this in the FIEMAP interface? Hm, or should this just be calculated from knowing the size of the sub-regions... -Eric