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=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 E366EC433E0 for ; Thu, 21 May 2020 23:48:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A673F207D8 for ; Thu, 21 May 2020 23:48:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728881AbgEUXsl (ORCPT ); Thu, 21 May 2020 19:48:41 -0400 Received: from bezitopo.org ([45.55.162.231]:57384 "EHLO marozi.bezitopo.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728537AbgEUXsk (ORCPT ); Thu, 21 May 2020 19:48:40 -0400 Received: from bezitopo.org (unknown [IPv6:2001:5b0:211f:ee48:4e72:b9ff:fe7b:8dbf]) by marozi.bezitopo.org (Postfix) with ESMTPSA id C95325FB5F for ; Thu, 21 May 2020 19:48:38 -0400 (EDT) Received: from puma.localnet (localhost [127.0.0.1]) by bezitopo.org (Postfix) with ESMTP id BBC69117F7 for ; Thu, 21 May 2020 19:48:26 -0400 (EDT) From: Pierre Abbat To: linux-btrfs@vger.kernel.org Subject: Re: Trying to mount hangs Date: Thu, 21 May 2020 19:48:26 -0400 Message-ID: <7541432.rVhWMRgfCE@puma> In-Reply-To: <87436f2d-40d2-5fa1-cdee-4cc4f63e68c9@gmx.com> References: <2549429.Qys7a5ZjRC@puma> <87436f2d-40d2-5fa1-cdee-4cc4f63e68c9@gmx.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thursday, May 21, 2020 3:56:01 AM EDT Qu Wenruo wrote: > That doesn't sound good. But according to your btrfs check result, your > memory doesn't look good. > There seems to be a memory bit flip. > > A full memtest is highly recommended. > > And since your hardware is not functioning reliable, everything can go > wrong. There was a thunderstorm. The power blinked twice within a few minutes. That could have easily caused the bit flip. > > UUID: 1f5a6f23-a7ef-46c6-92b1-84fc2f684931 > > [1/7] checking root items > > [2/7] checking extents > > incorrect local backref count on 4186230784 root 257 owner 99013 offset > > 5033684992 found 1 wanted 2097153 back 0x5589817e5ef0 > > Here, the 2097153 is 0x200001, it's an obvious bitflip. > > And since it's in extent tree, even write time tree checker can't detect it. > > But that problem is not a big thing, btrfs check --repair can fix it. > > Still, memtest first, only process to try repair after your memory is fixed. "btrfs check" gave me a "device busy" error. (When I booted the M.2, this was caused by the hung mount process, but it happened even when I booted the flash drive. I don't know why.) I couldn't repair it. I had to get a new drive and recover the files to the new drive. Trying to mount the corrupt filesystem consistently hangs. That indicates a bug in mount. How can I send you the corrupt filesystem so that you can debug mount? Pierre -- The Black Garden on the Mountain is not on the Black Mountain.