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=-3.8 required=3.0 tests=BAYES_00, 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 213A9C433ED for ; Sun, 16 May 2021 08:45:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DC73861183 for ; Sun, 16 May 2021 08:45:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230453AbhEPIqs (ORCPT ); Sun, 16 May 2021 04:46:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41978 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230248AbhEPIqs (ORCPT ); Sun, 16 May 2021 04:46:48 -0400 X-Greylist: delayed 174 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Sun, 16 May 2021 01:45:33 PDT Received: from smtp.mfedv.net (smtp.mfedv.net [IPv6:2a04:6c0:2::19]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC186C061573 for ; Sun, 16 May 2021 01:45:33 -0700 (PDT) Received: from suse92host.mfedv.net (suse92host.mfedv.net [IPv6:2a04:6c0:2:3:0:0:0:ffff]) by smtp.mfedv.net (8.15.2/8.15.2/Debian-10) with ESMTP id 14G8gTfj015880; Sun, 16 May 2021 08:42:30 GMT Received: from xoff (klappe2.mfedv.net [192.168.71.72]) by suse92host.mfedv.net (Postfix) with SMTP id E2B191180F6; Sun, 16 May 2021 10:42:28 +0200 (CEST) (envelope-from bcache@mfedv.net) Date: Sun, 16 May 2021 10:42:28 +0200 From: Matthias Ferdinand To: Thorsten Knabe Cc: linux-bcache@vger.kernel.org Subject: Re: PROBLEM: bcache related kernel BUG() since Linux 5.12 Message-ID: References: <58f92cd7-38d1-bc16-2b5f-b68b2db2233b@thorsten-knabe.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <58f92cd7-38d1-bc16-2b5f-b68b2db2233b@thorsten-knabe.de> Precedence: bulk List-ID: X-Mailing-List: linux-bcache@vger.kernel.org On Sat, May 15, 2021 at 09:06:07PM +0200, Thorsten Knabe wrote: > Hello. > > Starting with Linux 5.12 bcache triggers a BUG() after a few minutes of > usage. > > Linux up to 5.11.x is not affected by this bug. > > Environment: > - Debian 10 AMD 64 > - Kernel 5.12 - 5.12.4 > - Filesystem ext4 > - Backing device: degraded software RAID-6 (MD) with 3 of 4 disks active > (unsure if the degraded RAID-6 has an effect or not) > - Cache device: Single SSD Sorry I can't immediately help with bcache, but for DRBD, there was a similar problem with DRBD on degraded md-raid fixed just recently: https://lists.linbit.com/pipermail/drbd-user/2021-May/025904.html Although they had silent data corruption AFAICT, not a loud BUG(), and they stated problems started with kernel 4.3. For DRBD it had to do with split BIOs and readahead, which degraded md-raid may or may not fail, and missing a fail on parts of a split-up readahead BIO. Matthias