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 331FEC433FE for ; Fri, 10 Sep 2021 01:02:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 146AB610C7 for ; Fri, 10 Sep 2021 01:02:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235897AbhIJBDp (ORCPT ); Thu, 9 Sep 2021 21:03:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:49518 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234796AbhIJAYV (ORCPT ); Thu, 9 Sep 2021 20:24:21 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2051B6103E; Fri, 10 Sep 2021 00:23:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233388; bh=eNoERcqlwCN9kgjrVWZd4Q2Bfh3fgrljFvP8FgbdA+I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ayJaYxupXvx/avQKrAYTTjHITHT5MjWWivyXoEtwH49UuJ/PkoxDxfoVH+s6swPcK 0IKMqlbtxgFX7wRci6AoBZ0nOOpPxNopgQi+kJHNTekxr8AMOTi6/hvpI8CUJxgpND RrGNtgU29Ue3w5UwMxlKxVusLvA/D2g+FCgDMOWipjusnyGCr7oO/750BDoZNcjVXr s4OJfv5s+O8d79bJQaxbtCLJ9gpm7MX3eTznXTx3qUFd1TSKLLO4Y749WVIZ6Xqz7Q 2GjnM6GgrtUzYXNfU+fdXR3y+64TfIlV1liafSeOOcSAAICfUX9jS/Nl/EpDbm8lzP xD1UWbObS9ajQ== 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 4.19 25/25] ocfs2: ocfs2_downconvert_lock failure results in deadlock Date: Thu, 9 Sep 2021 20:22:33 -0400 Message-Id: <20210910002234.176125-25-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910002234.176125-1-sashal@kernel.org> References: <20210910002234.176125-1-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 8149fb6f1f0d..496d16376764 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -3880,6 +3881,17 @@ 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