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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 C9F89C433EF for ; Fri, 10 Sep 2021 00:44:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B84DB61108 for ; Fri, 10 Sep 2021 00:44:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241778AbhIJApe (ORCPT ); Thu, 9 Sep 2021 20:45:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:47232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233777AbhIJAVX (ORCPT ); Thu, 9 Sep 2021 20:21:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7A184610E9; Fri, 10 Sep 2021 00:20:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233213; bh=ZfP09m5w4LGh1ZGZG+EzEbW+bLxlL9P5Fvsc5CaZiW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gkerlsG+bUNRsYAHpZCN6V0Z9H5SuFGA2sQm+D1w5hGKkJuzVM5PaxRvYs8dytfvM RsYpCeQMekAvhh1ctCUVOsINaHf1d5rlXtE/cAfyyObBn+QNy6pCer/UY4z5syvtzS dI5Irz7+3SqDvMG5OeWsvSWwmdKUOAEjYvs+khPl8C28gUxSMnufklgSiPgw4d6Bch nl9iIlmuxtjBUwE/Rumug2x0/dE+XDcTR6JNI3X3mEmvarr00c7gocHo1Y2MpU018H EkAYIDHAvgf/skBGCWX0xpkj0rrrUV6I6Wnz0sTw/TbWNCI6b4PR0oK4orKTvDu7Ft WJWhmJ4FsWvRg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Gang He , Joseph Qi , Mark Fasheh , Joel Becker , Junxiao Bi , Changwei Ge , Jun Piao , Andrew Morton , Linus Torvalds , Sasha Levin , ocfs2-devel@oss.oracle.com Subject: [PATCH AUTOSEL 5.13 80/88] ocfs2: ocfs2_downconvert_lock failure results in deadlock Date: Thu, 9 Sep 2021 20:18:12 -0400 Message-Id: <20210910001820.174272-80-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910001820.174272-1-sashal@kernel.org> References: <20210910001820.174272-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Gang He [ Upstream commit 9673e0050c39b0534d0e2ca431223f52089f4959 ] Usually, ocfs2_downconvert_lock() function always downconverts dlm lock to the expected level for satisfy dlm bast requests from the other nodes. But there is a rare situation. When dlm lock conversion is being canceled, ocfs2_downconvert_lock() function will return -EBUSY. You need to be aware that ocfs2_cancel_convert() function is asynchronous in fsdlm implementation. If we does not requeue this lockres entry, ocfs2 downconvert thread no longer handles this dlm lock bast request. Then, the other nodes will not get the dlm lock again, the current node's process will be blocked when acquire this dlm lock again. Link: https://lkml.kernel.org/r/20210830044621.12544-1-ghe@suse.com Signed-off-by: Gang He Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Gang He Cc: Jun Piao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/ocfs2/dlmglue.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c index 48fd369c29a4..f8f561850470 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -3912,6 +3913,17 @@ static int ocfs2_unblock_lock(struct ocfs2_super *osb, spin_unlock_irqrestore(&lockres->l_lock, flags); ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb, gen); + /* The dlm lock convert is being cancelled in background, + * ocfs2_cancel_convert() is asynchronous in fs/dlm, + * requeue it, try again later. + */ + if (ret == -EBUSY) { + ctl->requeue = 1; + mlog(ML_BASTS, "lockres %s, ReQ: Downconvert busy\n", + lockres->l_name); + ret = 0; + msleep(20); + } leave: if (ret) -- 2.30.2