From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0AA16C4332D for ; Sat, 21 Mar 2020 17:46:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DFE68206F9 for ; Sat, 21 Mar 2020 17:46:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727872AbgCURqZ (ORCPT ); Sat, 21 Mar 2020 13:46:25 -0400 Received: from mx2.suse.de ([195.135.220.15]:55188 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726961AbgCURqY (ORCPT ); Sat, 21 Mar 2020 13:46:24 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id BBBB6AB8F; Sat, 21 Mar 2020 17:46:23 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id E97A8DA70B; Sat, 21 Mar 2020 18:45:53 +0100 (CET) Date: Sat, 21 Mar 2020 18:45:53 +0100 From: David Sterba To: Qu Wenruo Cc: fdmanana@kernel.org, linux-btrfs@vger.kernel.org Subject: Re: [PATCH] Btrfs: fix removal of raid[56|1c34} incompat flags after removing block group Message-ID: <20200321174553.GK12659@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Qu Wenruo , fdmanana@kernel.org, linux-btrfs@vger.kernel.org References: <20200320184348.845248-1-fdmanana@kernel.org> <8107ef53-5317-327c-674e-d5bd1b9d1e4d@gmx.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <8107ef53-5317-327c-674e-d5bd1b9d1e4d@gmx.com> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Sat, Mar 21, 2020 at 09:43:21AM +0800, Qu Wenruo wrote: > > > On 2020/3/21 上午2:43, fdmanana@kernel.org wrote: > > From: Filipe Manana > > > > We are incorrectly dropping the raid56 and raid1c34 incompat flags when > > there are still raid56 and raid1c34 block groups, not when we do not any > > of those anymore. The logic just got unintentionally broken after adding > > the support for the raid1c34 modes. > > > > Fix this by clear the flags only if we do not have block groups with the > > respective profiles. > > > > Fixes: 9c907446dce3 ("btrfs: drop incompat bit for raid1c34 after last block group is gone") > > Signed-off-by: Filipe Manana > > The fix is OK. > > Reviewed-by: Qu Wenruo > > Just interesting do we really need to remove such flags? > To me, keep the flag is completely sane. So you'd suggest to keep a flag for a feature that's not used on the filesystem so it's not possible to mount the filesystem on an older kernel?