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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84F6DCCA477 for ; Wed, 1 Jun 2022 15:16:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355181AbiFAPQa (ORCPT ); Wed, 1 Jun 2022 11:16:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354999AbiFAPQ3 (ORCPT ); Wed, 1 Jun 2022 11:16:29 -0400 Received: from mail-qk1-x734.google.com (mail-qk1-x734.google.com [IPv6:2607:f8b0:4864:20::734]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29E339159B for ; Wed, 1 Jun 2022 08:16:28 -0700 (PDT) Received: by mail-qk1-x734.google.com with SMTP id p123so1537897qke.5 for ; Wed, 01 Jun 2022 08:16:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20210112.gappssmtp.com; s=20210112; h=from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=y4nLfhtVjThLJOBWzaURdvTe4KZz4vjOxdl8B1WrSqw=; b=zRWp3MkdE4gSQ9AkLwt/nagne6DXwUXSvhXM6l3dXHCS6yhkHCznQq5A4t4O5SYCdc 3pWjzQmHxEBOeiTNGBrW02LjJKmPxg2K9esmcDgGpdfWuZa4g5OAUdakBB2EBSsuNXjB v7NN2NqZIN9EeUJZQGdMyLlog7KFE6IqpEyg00/YI6gJp+lmBIE7C0rQ/s3GLzCXwGRt wNSbU2MP0UuG7o/QytUxtY0ZdgE3Kvhup2VEJhB314wnGfOjulSNHu33RdjecT5wQ5PN /uYvxDqEgY5gdJ6RN8EYIELBGYXVTRqFCKhsVDfEJ09lb90vOe/KlVJGCbYd330LRUIt UrnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=y4nLfhtVjThLJOBWzaURdvTe4KZz4vjOxdl8B1WrSqw=; b=roNt9Y2xIp9nvwI+DrE8NNF8BZGvMropbJMjB9k/8pLiG67E5cgyB+j1NLI3c527Si TkeIDamonK8s+D4zcjENtqaaXnj8VH+1jr5U6YER1UAqbHmVCLD2qklA5Je1Vqf8Ey3j 5oZOdrlJdgjjS4qFxfaHKaPEE8WlcxIWstL2naagSnj6cagbumd2uPpwP2bSl9ilJuKR T6vE1WpjOO65SsPoBPiTyGWDVF/zGtq9vEZv48vFGSfaTq5MBuGhjv+1Bk/4S6EkkrmA Fg0IJWZ0/Ud+MN7LiVKcteS4DeNtlfON5fbSeo9VPYehggLYEThPXMZ5nDfacp6Xo85t /NVQ== X-Gm-Message-State: AOAM532j1YtiR24P1Sd3I1iYXpsVOW3eXdJ445juJB73i1Dutva2/5FA EIJWaD0XyV2ofrJ9kXRwKaykNzZr29SWfA== X-Google-Smtp-Source: ABdhPJyaTy+XysSKlxLGJ63xKn9DKq5A6wmk8jcAL4dOsFrzuKuBRfG0ED18CQkaWZGoMz6G2AT5Jg== X-Received: by 2002:a05:620a:c52:b0:6a6:6b8f:eac2 with SMTP id u18-20020a05620a0c5200b006a66b8feac2mr414179qki.643.1654096586875; Wed, 01 Jun 2022 08:16:26 -0700 (PDT) Received: from localhost (cpe-174-109-172-136.nc.res.rr.com. [174.109.172.136]) by smtp.gmail.com with ESMTPSA id o1-20020a05620a22c100b0069fcdbabdb4sm1357756qki.69.2022.06.01.08.16.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Jun 2022 08:16:26 -0700 (PDT) From: Josef Bacik To: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 0/2] btrfs: fix deadlock with fsync and full sync Date: Wed, 1 Jun 2022 11:16:23 -0400 Message-Id: X-Mailer: git-send-email 2.26.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hello, We've hit a pretty convoluted deadlock in production that Omar tracked down with drgn. I've described the deadlock in the second patch, but generally it's a lock inversion where we have an existing dependency of extent lock -> transaction, but in fsync in a few cases we can end up with transaction -> extent lock, and the expected hilarity ensues. Thanks, Josef Josef Bacik (2): btrfs: make the return value for log syncing consistent btrfs: fix deadlock with fsync+fiemap+full sync fs/btrfs/file.c | 67 +++++++++++++++++++++++++++++++++++---------- fs/btrfs/tree-log.c | 18 ++++++------ fs/btrfs/tree-log.h | 3 ++ 3 files changed, 64 insertions(+), 24 deletions(-) -- 2.26.3