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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 59166C433F5 for ; Fri, 10 Sep 2021 07:53:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2DEAB611C2 for ; Fri, 10 Sep 2021 07:53:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231583AbhIJHyb (ORCPT ); Fri, 10 Sep 2021 03:54:31 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:9027 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231502AbhIJHya (ORCPT ); Fri, 10 Sep 2021 03:54:30 -0400 Received: from dggeme752-chm.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4H5SlD5Jb0zVr3y; Fri, 10 Sep 2021 15:52:24 +0800 (CST) Received: from huawei.com (10.175.127.227) by dggeme752-chm.china.huawei.com (10.3.19.98) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Fri, 10 Sep 2021 15:53:18 +0800 From: Zhang Yi To: CC: , , , , Subject: [PATCH] ext4: recheck buffer uptodate bit under buffer lock Date: Fri, 10 Sep 2021 16:03:16 +0800 Message-ID: <20210910080316.70421-1-yi.zhang@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggeme752-chm.china.huawei.com (10.3.19.98) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Commit 8e33fadf945a ("ext4: remove an unnecessary if statement in __ext4_get_inode_loc()") forget to recheck buffer's uptodate bit again under buffer lock, which may overwrite the buffer if someone else have already brought it uptodate and changed it. Fixes: 8e33fadf945a ("ext4: remove an unnecessary if statement in __ext4_get_inode_loc()") Signed-off-by: Zhang Yi --- fs/ext4/inode.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index d18852d6029c..236adc647eb0 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4340,6 +4340,12 @@ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino, goto has_buffer; lock_buffer(bh); + if (ext4_buffer_uptodate(bh)) { + /* Someone brought it uptodate while we waited */ + unlock_buffer(bh); + goto has_buffer; + } + /* * If we have all information of the inode in memory and this * is the only valid inode in the block, we need not read the -- 2.31.1