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=-1.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 57391C10F0F for ; Fri, 5 Apr 2019 03:04:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1AA4D217D9 for ; Fri, 5 Apr 2019 03:04:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=colorremedies-com.20150623.gappssmtp.com header.i=@colorremedies-com.20150623.gappssmtp.com header.b="vtCkJI8q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729635AbfDEDEg (ORCPT ); Thu, 4 Apr 2019 23:04:36 -0400 Received: from mail-lj1-f174.google.com ([209.85.208.174]:35466 "EHLO mail-lj1-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727051AbfDEDEf (ORCPT ); Thu, 4 Apr 2019 23:04:35 -0400 Received: by mail-lj1-f174.google.com with SMTP id t4so3925368ljc.2 for ; Thu, 04 Apr 2019 20:04:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=colorremedies-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=q+K+ErqzaOqAygquobVGRWCFwDA1lh0NafFnZZuJDMY=; b=vtCkJI8qCjI1PjLyz2frKY+FisXdsjPduqYgl7IE7o5OGX9XrL2wh13tHKTGnzvFTR FjJxcmsh+ErjOs6W+QvFext5T85KUZl5pSvzPDU+Dh2Zz+LGMrmeRIFc6lPQ3CmlbkKe RZt1ecPC4Ss86ZJYF5nnoHBiZweDxFxrWeixf+oY3cgIulWkN2h6hsHl2VRLWJHvL02K d3HJI6dTw6FpeUQS+BR8E2jdbscFBkC7fMBelSfJ0k/WkGMw4kWjgjXNE+bDRUfy/x72 Fg0ja01kRw7FGAHhm6SmfLGrgUkpSujPvGywCssuT+PKqiMGn/dwSArLwQMGDxwyeAfo 7/mw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=q+K+ErqzaOqAygquobVGRWCFwDA1lh0NafFnZZuJDMY=; b=bfO79Kq/SpDlVjyBdaSSOEVJCaW48k810scGB9kj/MPhH2AfTu5xNV8ERkmBZ5sCmF C2mofT4hk7BtInHTOj836MwrcYcjFFgeJ2WnmZevCeURSgbzDZegkQHUgM44mDak5eAV Bow1nlf2sto1f89m8gOwcfxhW6NJJ+gtBWq6KbMKXH1SJpr/XfFbu9eL2j6g3/fcSBeM y7uoUWSOX95C5EaoG51/8Fy5XbyEyJtx/v0XwUDbvFSoCn+hXutyc0GHvqXfYUVbSSWE nycsvtCGIMbckvqz45FwVHXxFCMUdURu5wSBmVpBDJVY/IYBLz+ZoGrI13ue+yp5Sxto RaTg== X-Gm-Message-State: APjAAAWLrEWR5+4/NGZPokPne7I73h4c0X/hqoEOTYHL8B7pHf94EPOu AuDmcitNecnUsFPivi9xn2OSMn3dOmp5hiOJOJ3HWSs1e2A= X-Google-Smtp-Source: APXvYqz1orqU/mIVtaOE15Aon7WBqaFA69jiLgDVQUl0ikORFI2BAf0KG9MgAkSbnQgMzWbkRIeBvYRacm9hR65n46Y= X-Received: by 2002:a2e:7e0f:: with SMTP id z15mr5476250ljc.122.1554433473292; Thu, 04 Apr 2019 20:04:33 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Chris Murphy Date: Thu, 4 Apr 2019 21:04:21 -0600 Message-ID: Subject: Re: btrfs balance hangs To: Zirconium Hacker Cc: Btrfs BTRFS , Qu Wenruo Content-Type: text/plain; charset="UTF-8" Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, Apr 4, 2019 at 12:18 PM Zirconium Hacker wrote: > > Yes, I have qgroups enabled on that filesystem. I'll disable qgroups > the next chance I get, they aren't worth the trouble. > > After rebooting, BTRFS finished the balance. I then foolishly started > a selective metadata balance, which never got past the first block > group; it just thrashed the disk for several hours. > It could not be canceled, so I rebooted. > > Then I mounted the filesystem with skip_balance and clear_cache. > The mount failed. The relevant part of dmesg is attached. I can't parse that, maybe Qu has an idea. In the meantime I suggest btrfs-progs 4.20.2 and running: # btrfs check --readonly /dev/ Attach that output. Balance is supposed to be COW. And skip_balance and clear_cache are supposed to be safe. So I'd say you've found a bug but I don't know what it is or how to work around it. -- Chris Murphy