From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.fusionio.com ([66.114.96.31]:52858 "EHLO mx2.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755199Ab2IFNL4 (ORCPT ); Thu, 6 Sep 2012 09:11:56 -0400 Date: Thu, 6 Sep 2012 09:11:53 -0400 From: Josef Bacik To: Liu Bo CC: "linux-btrfs@vger.kernel.org" , "dave@jikos.cz" Subject: Re: [PATCH v2 2/2] Btrfs: snapshot-aware defrag Message-ID: <20120906131153.GB18438@localhost.localdomain> References: <1346893852-9815-1-git-send-email-bo.li.liu@oracle.com> <1346893852-9815-2-git-send-email-bo.li.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <1346893852-9815-2-git-send-email-bo.li.liu@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Wed, Sep 05, 2012 at 07:10:52PM -0600, Liu Bo wrote: > This comes from one of btrfs's project ideas, > As we defragment files, we break any sharing from other snapshots. > The balancing code will preserve the sharing, and defrag needs to grow this > as well. > > Now we're able to fill the blank with this patch, in which we make full use of > backref walking stuff. > > Here is the basic idea, > o set the writeback ranges started by defragment with flag EXTENT_DEFRAG > o at endio, after we finish updating fs tree, we use backref walking to find > all parents of the ranges and re-link them with the new COWed file layout by > adding corresponding backrefs. > > Original-Signed-off-by: Li Zefan > Signed-off-by: Liu Bo > --- > v2: rebase against the latest btrfs-repo > Heh well it doesn't apply onto btrfs-next, try again please :). Thanks, Josef