From patchwork Mon Nov 15 11:00:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jubin Zhong X-Patchwork-Id: 12619315 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02C6FC433EF for ; Mon, 15 Nov 2021 11:01:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CDEEC615A4 for ; Mon, 15 Nov 2021 11:01:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237875AbhKOLDw (ORCPT ); Mon, 15 Nov 2021 06:03:52 -0500 Received: from szxga03-in.huawei.com ([45.249.212.189]:27207 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237850AbhKOLDW (ORCPT ); Mon, 15 Nov 2021 06:03:22 -0500 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Ht5ll5Ws5z8vQv; Mon, 15 Nov 2021 18:58:43 +0800 (CST) Received: from dggpemm500007.china.huawei.com (7.185.36.183) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 15 Nov 2021 19:00:23 +0800 Received: from use12-sp2.huawei.com (10.67.189.20) by dggpemm500007.china.huawei.com (7.185.36.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 15 Nov 2021 19:00:23 +0800 From: Jubin Zhong To: CC: , , , Subject: [PATCH] fs: Fix truncate never updates m/ctime Date: Mon, 15 Nov 2021 19:00:18 +0800 Message-ID: <1636974018-31285-1-git-send-email-zhongjubin@huawei.com> X-Mailer: git-send-email 1.8.5.6 MIME-Version: 1.0 X-Originating-IP: [10.67.189.20] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500007.china.huawei.com (7.185.36.183) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: zhongjubin Syscall truncate() never updates m/ctime even if the file size is changed. However, this is incorrect according to man file: truncate (2): If the size changed, then the st_ctime and st_mtime fields (respectively, time of last status change and time of last modification; see stat(2)) for the file are updated, and the set-user-ID and set-group-ID mode bits may be cleared. Check file size before do_truncate() to fix this. Signed-off-by: zhongjubin --- fs/open.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/open.c b/fs/open.c index f732fb94600c..02404b759c2e 100644 --- a/fs/open.c +++ b/fs/open.c @@ -106,8 +106,11 @@ long vfs_truncate(const struct path *path, loff_t length) goto put_write_and_out; error = security_path_truncate(path); - if (!error) - error = do_truncate(mnt_userns, path->dentry, length, 0, NULL); + if (error) + goto put_write_and_out; + + if (i_size_read(inode) != length) + error = do_truncate(mnt_userns, path->dentry, length, ATTR_MTIME | ATTR_CTIME, NULL); put_write_and_out: put_write_access(inode);