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=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 27448C47404 for ; Thu, 12 Sep 2019 13:09:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EEF992084D for ; Thu, 12 Sep 2019 13:09:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732006AbfILNJy (ORCPT ); Thu, 12 Sep 2019 09:09:54 -0400 Received: from mailgw-02.dd24.net ([193.46.215.43]:60546 "EHLO mailgw-02.dd24.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731786AbfILNJy (ORCPT ); Thu, 12 Sep 2019 09:09:54 -0400 Received: from mailpolicy-01.live.igb.homer.key-systems.net (mailpolicy-02.live.igb.homer.key-systems.net [192.168.1.27]) by mailgw-02.dd24.net (Postfix) with ESMTP id 905935FD8B; Thu, 12 Sep 2019 13:09:52 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mailpolicy-02.live.igb.homer.key-systems.net Received: from smtp.dd24.net ([192.168.1.36]) by mailpolicy-01.live.igb.homer.key-systems.net (mailpolicy-02.live.igb.homer.key-systems.net [192.168.1.25]) (amavisd-new, port 10236) with ESMTP id Ti00DtwrCd58; Thu, 12 Sep 2019 13:09:50 +0000 (UTC) Received: from gar-nb-etp23.garching.physik.uni-muenchen.de (unknown [141.84.41.131]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.dd24.net (Postfix) with ESMTPSA; Thu, 12 Sep 2019 13:09:50 +0000 (UTC) Message-ID: Subject: Re: Massive filesystem corruption since kernel 5.2 (ARCH) From: Christoph Anton Mitterer To: fdmanana@gmail.com Cc: linux-btrfs Date: Thu, 12 Sep 2019 15:09:50 +0200 In-Reply-To: References: <11e4e889f903ddad682297c4420faeb0245414cf.camel@scientia.net> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hi. First, thanks for finding&fixing this :-) On Thu, 2019-09-12 at 08:50 +0100, Filipe Manana wrote: > 1) either a hang when committing a transaction, reported by several > users recently and hit it myself too twice when running fstests (test > case generic/475 and generic/561) after I upgradaded my development > branch from a 5.1.x kernel to a 5.3-rcX kernel. If this happens you > risk no corruption, still the hang is very inconvenient of course, as > you have to reboot. Okay inconvenient, but not so bad if there is no corruption risk. > 2) writeback for some btree nodes may never be started and we end up > committing a transaction without noticing that. This is really > serious > and that will lead to the "parent transid verify failed on ..." > messages. As some people have already pointed out, it will be infeasible for many end users to downgrade (no security updates) or manually patch (well, end-users). Can you elaborate under which circumstances this problem occurs, whether there are any intermediate workarounds, and whether it's always noticed (i.e. no silence corruption)? Thanks, Chris.