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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 6AE5EC83000 for ; Tue, 28 Apr 2020 13:14:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50388206A1 for ; Tue, 28 Apr 2020 13:14:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726946AbgD1NOu (ORCPT ); Tue, 28 Apr 2020 09:14:50 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:53036 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726764AbgD1NOt (ORCPT ); Tue, 28 Apr 2020 09:14:49 -0400 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id E60FA5E7908F185C8AFE; Tue, 28 Apr 2020 21:14:47 +0800 (CST) Received: from huawei.com (10.175.105.27) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.487.0; Tue, 28 Apr 2020 21:14:37 +0800 From: Wu Bo To: , , CC: , , , , Subject: [PATCH V2] fs/ceph:fix double unlock in handle_cap_export() Date: Tue, 28 Apr 2020 21:13:42 +0800 Message-ID: <1588079622-423774-1-git-send-email-wubo40@huawei.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.105.27] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org if the ceph_mdsc_open_export_target_session() return fails, should add a lock to avoid twice unlocking. Because the lock will be released at the retry or out_unlock tag. -- v1 -> v2: add spin_lock(&ci->i_ceph_lock) before goto out_unlock tag. Signed-off-by: Wu Bo --- fs/ceph/caps.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 185db76..414c0e2 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -3731,22 +3731,25 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex, /* open target session */ tsession = ceph_mdsc_open_export_target_session(mdsc, target); - if (!IS_ERR(tsession)) { - if (mds > target) { - mutex_lock(&session->s_mutex); - mutex_lock_nested(&tsession->s_mutex, - SINGLE_DEPTH_NESTING); - } else { - mutex_lock(&tsession->s_mutex); - mutex_lock_nested(&session->s_mutex, - SINGLE_DEPTH_NESTING); - } - new_cap = ceph_get_cap(mdsc, NULL); - } else { + if (IS_ERR(tsession)) { WARN_ON(1); tsession = NULL; target = -1; + mutex_lock(&session->s_mutex); + spin_lock(&ci->i_ceph_lock); + goto out_unlock; + } + + if (mds > target) { + mutex_lock(&session->s_mutex); + mutex_lock_nested(&tsession->s_mutex, + SINGLE_DEPTH_NESTING); + } else { + mutex_lock(&tsession->s_mutex); + mutex_lock_nested(&session->s_mutex, + SINGLE_DEPTH_NESTING); } + new_cap = ceph_get_cap(mdsc, NULL); goto retry; out_unlock: -- 1.8.3.1