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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 BCAE5C433E1 for ; Thu, 23 Jul 2020 21:54:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C9F520714 for ; Thu, 23 Jul 2020 21:54:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726436AbgGWVyd (ORCPT ); Thu, 23 Jul 2020 17:54:33 -0400 Received: from james.kirk.hungrycats.org ([174.142.39.145]:48248 "EHLO james.kirk.hungrycats.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726304AbgGWVyd (ORCPT ); Thu, 23 Jul 2020 17:54:33 -0400 Received: by james.kirk.hungrycats.org (Postfix, from userid 1002) id 4072E77BA3C; Thu, 23 Jul 2020 17:54:31 -0400 (EDT) Date: Thu, 23 Jul 2020 17:54:30 -0400 From: Zygo Blaxell To: dsterba@suse.cz, Qu Wenruo , linux-btrfs@vger.kernel.org Subject: Re: [PATCH 0/2] btrfs: balance root leak and runaway balance fix Message-ID: <20200723215430.GC5890@hungrycats.org> References: <20200520065851.12689-1-wqu@suse.com> <20200522111347.GJ18421@twin.jikos.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200522111347.GJ18421@twin.jikos.cz> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Fri, May 22, 2020 at 01:13:47PM +0200, David Sterba wrote: > On Wed, May 20, 2020 at 02:58:49PM +0800, Qu Wenruo wrote: > > This patchset will fix the most wanted balance bug, runaway balance. > > All my fault, and all small fixes. > > Well, that happens. > > d2311e698578 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots") > > is the most broken patch in recent history (5.1+), there were so many > fixups but hopefully this is the last one. I've tagged the patches for > 5.1+ stable but we'll need manual backports due to the root refcount > changes in 5.7. The patch 1dae7e0e58b4 "btrfs: reloc: clear DEAD_RELOC_TREE bit for orphan roots to prevent runaway balance" does apply to 5.7 itself, but it is not present in 5.7.10. I've been running it in test (and even a few pre-prod) systems since May. We still get someone in IRC with a runaway balance every week or so. Currently we can only tell them to wait for 5.8, or roll all the way back to 4.19. > I reproduced the umount crash and verified the fix, the runaway balance > does not happen anymore in the test so I guess we have all the needed > fixes in place to allow the fast balance cancel. Thanks.