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 A78C4C433F5 for ; Fri, 10 Sep 2021 01:00:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F2136113E for ; Fri, 10 Sep 2021 01:00:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233903AbhIJBBk (ORCPT ); Thu, 9 Sep 2021 21:01:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:49092 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234580AbhIJAXn (ORCPT ); Thu, 9 Sep 2021 20:23:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B47AA6103E; Fri, 10 Sep 2021 00:22:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233353; bh=nfZcZfMndzPM5mHE2ZHlY1bfXb9A1B361MXkBXNqWIA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DLJVS/M/XBDpArMb+Xa7R4tPEezD9JfqKTJyfl2S9kKxXLd69+inb72Q7ry+KpdwE dmu3BZ9mON6ELcaD9wkx0m2UmzqNihM93q8Mc5U6UqQiTw68quBgpHrbHYvzE1CzrT f7TX156HD8w8znRspJ4gepIoU6zzI96F/3vKmaQcKIpLriTswm6oFD5uVb2dsepJR/ KA8NBn105ydsvTI3OPHYv33rTWGOGR4n+72tF6ttZkUQ1YXGNBnLDhxP8OWgq2CRb2 BhyZ7Bn9BpYCaURWiR0ad4jZCRm25f52xAfxbMVialtHOLLsJ7jOJD37LTsmlI4MKA NZWR6w9o/uSBg== 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 5.4 37/37] ocfs2: ocfs2_downconvert_lock failure results in deadlock Date: Thu, 9 Sep 2021 20:21:42 -0400 Message-Id: <20210910002143.175731-37-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910002143.175731-1-sashal@kernel.org> References: <20210910002143.175731-1-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 50a863fc1779..7b27379abe02 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -3906,6 +3907,17 @@ 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