From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759280AbZEPJnR (ORCPT ); Sat, 16 May 2009 05:43:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758863AbZEPJmc (ORCPT ); Sat, 16 May 2009 05:42:32 -0400 Received: from mail.lang.hm ([64.81.33.126]:33573 "EHLO bifrost.lang.hm" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758879AbZEPJma (ORCPT ); Sat, 16 May 2009 05:42:30 -0400 Date: Sat, 16 May 2009 02:42:17 -0700 (PDT) From: david@lang.hm X-X-Sender: dlang@asgard To: Theodore Tso cc: Timo Sirainen , Josef Bacik , linux-kernel@vger.kernel.org Subject: Re: ext3/ext4 directories don't shrink after deleting lots of files In-Reply-To: <20090515105815.GD6816@mit.edu> Message-ID: References: <1242338523.6933.664.camel@timo-desktop> <1b7401870905141732v43bd7321g1f0d9721b5e3f761@mail.gmail.com> <605A8D56-81CD-4775-8FCD-58CDB12CBA36@iki.fi> <20090515105815.GD6816@mit.edu> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 15 May 2009, Theodore Tso wrote: > On Thu, May 14, 2009 at 08:45:38PM -0400, Timo Sirainen wrote: >> >> I was rather thinking something that I could run while the system was >> fully operational. Otherwise just moving the files to a temp directory + >> rmdir() + rename() would have been fine too. >> >> I just tested that xfs, jfs and reiserfs all shrink the directories >> immediately. Is it more difficult to implement for ext* or has no one >> else found this to be a problem? > > It's probably fairest to say no one has thought it worth the effort. > It would require some fancy games to swap out block locations in the > extent trees (life would be easier with non-extent-using inodes), and > in the case of htree, we would have to keep track of the index block > so we could remove it from the htree index. So it's all doable, if a > bit tricky in terms of the technical details; it's just that the > people who could do it have been busy enough with other things. > > It's hasn't been considered high priority because most of the time > directories don't go from holding thousands of files down to a small > handful. I see it on a fairly regular basis on mail servers. in sendng a large queue builds up due to a remote system being down, but then after the remote system recovers, all access to that directory is slow, hurting everything else on the system. David Lang