From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:39702 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752304AbeCURvE (ORCPT ); Wed, 21 Mar 2018 13:51:04 -0400 Date: Wed, 21 Mar 2018 18:48:38 +0100 From: David Sterba To: "Misono, Tomohiro" Cc: linux-btrfs Subject: Re: [PATCH] btrfs-progs: mkfs: add uuid and otime to ROOT_ITEM of FS_TREE Message-ID: <20180321174838.GW6955@twin.jikos.cz> Reply-To: dsterba@suse.cz References: <7ca269db-a724-5938-f4d8-b85e893fd558@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <7ca269db-a724-5938-f4d8-b85e893fd558@jp.fujitsu.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Mon, Mar 19, 2018 at 05:16:42PM +0900, Misono, Tomohiro wrote: > Currently, the top-level subvolume lacks the UUID. As a result, both > non-snapshot subvolume and snapshot of top-level subvolume do not have > Parent UUID and cannot be distinguisued. Therefore "fi show" of > top-level lists all the subvolumes which lacks the UUID in > "Snapshot(s)" filed. Also, it lacks the otime information. > > Fix this by adding the UUID and otime at the mkfs time. As a > consequence, snapshots of top-level subvolume now have a Parent UUID and > UUID tree will create an entry for top-level subvolume at mount time. > This should not cause the problem for current kernel, but user program > which relies on the empty Parent UUID may be affected by this change. > > Signed-off-by: Tomohiro Misono So this adds uuid, ctime and otime to FS_TEEE but also to UUID_TREE and DATA_RELOC_TREE. This is harmelss, but would be nice to mention in the changelog, I'll apply the patch add that. Thanks.