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 794FDC433F5 for ; Fri, 10 Sep 2021 01:05:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CE01610C9 for ; Fri, 10 Sep 2021 01:05:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245496AbhIJBE5 (ORCPT ); Thu, 9 Sep 2021 21:04:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:49854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234851AbhIJAYr (ORCPT ); Thu, 9 Sep 2021 20:24:47 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CA01F610A3; Fri, 10 Sep 2021 00:23:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233417; bh=KWyYM3tCYWDLvluZhhcI7+TlsnbbqbsPDGuezDLKUME=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EDJigrKSLGdksdLOAO8r9yroSFFFyavdJiZ/co6BwKW181GZENFDWIfNEvS7vhtjD w+wBEo0O1Qe5bpfSvD1TqJHntkMoxy0HBhMLUSk5Pey8b5A7mlDGnZ8Rfsuu5IrGim TiCtdjVV7pHtahXh/xA1PuZ9Qw6elVmHnfQ/dF47cGMulbMcGAxvoJpz8H/EB9Gx9s zbFyoufxIwPifCCU5euPrKUuM9/RzEbNDSjLcZ3RDzqGeR3gCdCtp0/1xL0iJH92vf MQkMeezMTzBO3mdBUCExaJWQabMy2M/BP2ljSP2vw5eZwFjdg83W59xnUCQ3lAm0Yf XxA2gK5bRL4Ug== 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 4.14 19/19] ocfs2: ocfs2_downconvert_lock failure results in deadlock Date: Thu, 9 Sep 2021 20:23:09 -0400 Message-Id: <20210910002309.176412-19-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910002309.176412-1-sashal@kernel.org> References: <20210910002309.176412-1-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: linux-kernel@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 e961015fb484..ab4fad6893ab 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -3678,6 +3679,17 @@ 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