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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 1A0BACA9EAF for ; Mon, 21 Oct 2019 13:03:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E1CB320679 for ; Mon, 21 Oct 2019 13:03:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="RVZ1ytdR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728831AbfJUNDe (ORCPT ); Mon, 21 Oct 2019 09:03:34 -0400 Received: from mail-ed1-f43.google.com ([209.85.208.43]:37073 "EHLO mail-ed1-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728829AbfJUNDd (ORCPT ); Mon, 21 Oct 2019 09:03:33 -0400 Received: by mail-ed1-f43.google.com with SMTP id r4so9945345edy.4 for ; Mon, 21 Oct 2019 06:03:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ln31ItBN6c43yOKakjwFCr7pqh/RYcQKe74wxeRuEWw=; b=RVZ1ytdRlWmzBPr2jUvoOAU1+6s5aZV9sq3J3fn/iTiuQ7jeChP4fTIlfj1YCoh71F Fvu+kRKlU2XzKbE1muHR8FdC7+fsfsGZ0uxTpus5Al7dE3RW9g5924+kjPu7ZHDz/hRr k2xMKDlBwSZ4bVW1IoRUsr8sHpayiDnsNjyOlOoMIbY5tRjSyUkD0gODnFxfNpquJJPC TH7h8gJck5L2dL/jhOy9jQav8tTu2SIkICtOarag+cNtSTrvelRpRM4oF4qT2C/Hza6s c0mr74QScMvIyDbazKanvelWkKgcZjES8wefOGiwrndBdilF1ghF3ik+dr+dA+w0ICNB 4Etw== 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=ln31ItBN6c43yOKakjwFCr7pqh/RYcQKe74wxeRuEWw=; b=f+thQRoCQBLAUGLolQuPH3NRhJU7TXo16Zy1jKoHZNxieDV+WoVpUj6035uVamq0RP XBaVd9YH4wUG5KjmsLBMI6GDhCRySlIPP/lWkbU3TgbCCcq2GmISEzheYuRGd8jth1Dt f+lKiezewtsglfOB3JrgKBFDGwAwA6wLLNOivM07q5vpZ6Y8KnL5cqhDiCVSgRpRSB5c AxMOcrhyxIpfB0z33wKTC7OovLHnexzuxCTs3ZYy6PZwWY+LJnO5WVSpDYbalb+bUKii YeYqVphWIgJHPvEsCWidi1H5vyTnwlkfJYihVT0XdD4WJRqAWvZBGB155OiZL5auWeeW asXA== X-Gm-Message-State: APjAAAV28YrUkWMLQWe+j4y/TBgUjauwiz+YciVDJRSKMsfXlfW2gCZP EejS0Q2M3DRS9H/j2WXyWZRL7sY8rkOsLUvDPgvqTyY= X-Google-Smtp-Source: APXvYqxIezNDMl3+UJr6vgRKqY+SpJ46XqPVMVVQyw7/psZCUWORbu6sQF8el/CkxXMkOsQNoouUxSgyMunank0mK74= X-Received: by 2002:a05:6402:1acd:: with SMTP id ba13mr7638856edb.141.1571663011986; Mon, 21 Oct 2019 06:03:31 -0700 (PDT) MIME-Version: 1.0 References: <4608b644-0fa3-7212-af45-0f4eebfb0be9@gmx.com> In-Reply-To: From: Christian Pernegger Date: Mon, 21 Oct 2019 15:02:55 +0200 Message-ID: Subject: Re: first it froze, now the (btrfs) root fs won't mount ... To: "Austin S. Hemmelgarn" Cc: Qu Wenruo , linux-btrfs 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 [Please CC me, I'm not on the list.] Am Mo., 21. Okt. 2019 um 13:47 Uhr schrieb Austin S. Hemmelgarn : > I've [worked with fs clones] like this dozens of times on single-device volumes with exactly zero issues. Thank you, I have taken precautions, but it does seem to work fine. > There are actually two possible ways I can think of a buggy GPU driver causing this type of issue: [snip] Interesting and plausible, but ... > Your best option for mitigation [...] is to ensure that your hardware has an IOMMU [...] and ensure it's enabled in firmware. It has and it is. (The machine's been specced so GPU pass-through is an option, should it be required. I haven't gotten around to setting that up yet, haven't even gotten a second GPU, but I have laid the groundwork, the IOMMU is enabled and, as far as one can tell from logs and such, working.) > However, there's also the possibility that you may have hardware issues. Don't I know it ... The problem is, if there are hardware issues, that's the first I've seen of them, and while I didn't run torture tests, there was quite a lot of benchmarking when it was new. Needle in a haystack. Some memory testing can't hurt, I suppose. Any other ideas (for hardware testing)? Back on the topic of TRIM: I'm 99 % certain discard wasn't set on the mount (not by me, in any case), but I think Mint runs fstrim periodically by default. Just to be sure, should any form of TRIM be disabled? The only other idea I've got is Timeshift's hourly snapshots. (How) would btrfs deal with a crash during snapshot creation? In other news, I've still not quite given up, mainly because the fs doesn't look all that broken. The output of btrfs inspect-internal dump-tree (incl. options), for instance, looks like gibberish to me of course, but it looks sane, doesn't spew warnings, doesn't error out or crash. Also plain btrfs check --init-extent-tree errored out, same with -s0, but with -s1 it's now chugging along. (BTW, is there a hierarchy among the super block slots, a best or newest one?) Will keep you posted. Cheers, C.