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=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 92EC6C433E1 for ; Fri, 21 Aug 2020 09:58:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D33F207DF for ; Fri, 21 Aug 2020 09:58:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728394AbgHUJ6N (ORCPT ); Fri, 21 Aug 2020 05:58:13 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:60015 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728004AbgHUJ6N (ORCPT ); Fri, 21 Aug 2020 05:58:13 -0400 X-Originating-IP: 82.67.131.7 Received: from [10.137.0.38] (unknown [82.67.131.7]) (Authenticated sender: swami@petaramesh.org) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 40532240003; Fri, 21 Aug 2020 09:58:10 +0000 (UTC) To: linux-bcache@vger.kernel.org, BTRFS Cc: kent.overstreet@gmail.com, swami@petaramesh.org From: =?UTF-8?Q?Sw=c3=a2mi_Petaramesh?= Subject: Complete disparition of BTRFS FS on bcache, kernel 5.8 Message-ID: <98e963a4-dbd0-7d7b-e8e5-cd846cd6c418@petaramesh.org> Date: Fri, 21 Aug 2020 11:58:08 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hello, I have a Manjaro system on which the disks setup is as follows : sda : mechanical HD - sda1 -> LUKS encryption -> bcache backing dev bcache0 -> BTRFS FS -> /home sdb : SSD - sdb1 -> System EFI partition - sdb2 -> LUKS encryption -> BTRFS FS -> / (system root FS) - sdb3 -> LUKS encryption -> bcache cache dev bcache0 (for /home) - sdb4 -> LUKS encryption -> SWAP bcache working in writeback mode. This setup had worked perfectly flawlessly for more than a year with different kernel versions. Then I upgraded to Manjaro kernel 5.8 I was immediately under the impression that the overall disks access performance had much worsened. Then, after I had worked on a couple VMs hosted on the bcache'd FS, I tried to power the system down normally from the GUI menu. At that time there was high disk activity going on and systemd waited for more than 1'30" trying to unmount the FSes, to no avail. Looks like everything didn't make it to disk before it eventually timed out. Afterwards systemd killed the processes and powered down the system. At next powerup, the bcache would activate as usual, but the BTRFS filesystem on it was completely *GONE*. The “file” utility would identify the device as “data” (not an FS), mount would complain that this wasn't any recognizable FS anymore, and “btrfs-find-root” wouldn't find anything. AFAIK the FS is completely gone. I've been using BTRFS over bcache over LUKS (on 2 machines) for years, and it was usually very stable until today. Both the HD and SSD looks healthy and their SMART do not record any error, remapped sectors, or other issue. So this was just to let you know... There might be some new kernel issue in bcache or BTRFS or their relation to one another. Best regards. ॐ -- Swâmi Petaramesh PGP 9076E32E