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 C6840C28B23 for ; Fri, 10 Sep 2021 00:45:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8BB661108 for ; Fri, 10 Sep 2021 00:45:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242292AbhIJAqr (ORCPT ); Thu, 9 Sep 2021 20:46:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:48440 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231563AbhIJAWu (ORCPT ); Thu, 9 Sep 2021 20:22:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id F0FD1604DC; Fri, 10 Sep 2021 00:21:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233300; bh=dp4wSqm3sfSb+t/V4j7I6BKE9+blk1saDdAg4tgNn8s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LSu/hrg1JDh6HyW2SCZbEp2yUivX34j73KmKBsLs8K2BtBO2uXm4PeDBhGJPOFjVw A3/jNP8IOTaD3kI2aLefUdhmG3/+1hmD7OJOQFPzr9OUZYyhiaMSS+B/WjumVakxEX +LC9Sn4Mvvx5GA61sdtLigH0Amcsowjt51gbG9zmwD0+7BpriFKQ4n6dlzVpstpcE2 fxnnhGkyPQjeQRpAzRbyl2lzu48YRMqXmaBHIskc+L9POns3gzuo15xrLrr0p3saPS UtHagFr0CIQqjrccegm+qF6K0HywHv510kY+zoNE+X0XW/9dDwj/Miwi/Kp8hMLqKc g/RxXPA2ujS7g== 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 5.10 52/53] ocfs2: ocfs2_downconvert_lock failure results in deadlock Date: Thu, 9 Sep 2021 20:20:27 -0400 Message-Id: <20210910002028.175174-52-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910002028.175174-1-sashal@kernel.org> References: <20210910002028.175174-1-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 8e3a369086db..01cf5211b5c8 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