From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dkim1.fusionio.com ([66.114.96.53]:35205 "EHLO dkim1.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752395Ab3FGOsC (ORCPT ); Fri, 7 Jun 2013 10:48:02 -0400 Received: from mx1.fusionio.com (unknown [10.101.1.160]) by dkim1.fusionio.com (Postfix) with ESMTP id 4B1507C0692 for ; Fri, 7 Jun 2013 08:48:02 -0600 (MDT) Date: Fri, 7 Jun 2013 10:47:59 -0400 From: Josef Bacik To: Stefan Behrens CC: Josef Bacik , "linux-btrfs@vger.kernel.org" Subject: Re: [PATCH v4 6/8] Btrfs: introduce uuid-tree-gen field Message-ID: <20130607144759.GF29248@localhost.localdomain> References: <49cfd0aca92177345f59f3f700f6d43f8445f405.1370534938.git.sbehrens@giantdisaster.de> <20130607143916.GE29248@localhost.localdomain> <51B1F130.90401@giantdisaster.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <51B1F130.90401@giantdisaster.de> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Fri, Jun 07, 2013 at 08:41:52AM -0600, Stefan Behrens wrote: > On 06/07/2013 16:39, Josef Bacik wrote: > > On Fri, Jun 07, 2013 at 04:27:51AM -0600, Stefan Behrens wrote: > >> In order to be able to detect the case that a filesystem is mounted > >> with an old kernel, add a uuid-tree-gen field like the free space > >> cache is doing it. It is part of the super block and written with > >> each commit. Old kernels do not know this field and don't update it. > >> > > > > So to get around the whole crashing before we finish creating the uuid tree > > maybe set some flag or something that doesn't actually set the > > super->uuid_tree_generation until _after_ it finishes populating the tree, and > > then have the scan deal with having a half populated tree. Just an idea, but we > > have to deal with it some way. Thanks, > > That's what the patch 7/8 is doing. > Yeah I just noticed that, thanks. Josef