From patchwork Wed May 29 17:43:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amir Goldstein X-Patchwork-Id: 10967511 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E6A5D18EC for ; Wed, 29 May 2019 17:44:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D802428917 for ; Wed, 29 May 2019 17:44:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D5EC328A48; Wed, 29 May 2019 17:44:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 72B8328A4E for ; Wed, 29 May 2019 17:44:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727275AbfE2Rnm (ORCPT ); Wed, 29 May 2019 13:43:42 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:35474 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726205AbfE2Rnl (ORCPT ); Wed, 29 May 2019 13:43:41 -0400 Received: by mail-wm1-f67.google.com with SMTP id w9so2181935wmi.0; Wed, 29 May 2019 10:43:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=scXNy7Kv0jk0u1cUOdecKgwqwG5sRFulap1lrncxuHo=; b=s+jtsDe6rXzCxWe4+vL2LKW99Wa6fSQ5fJFeqRL0+ypE7CjnvYTV/ENnJOM8O84F8G eyfHIA3Gs9BWZnUk8XBCWOztvFKUdmdjhcw1s3ScNe91pfBhIJsOS1aQlOESy/Pwt5OF EVjvnDjIC28XzmPo+yat+GOs+8DNr7Z14d8QMSGG4b2EhvxSbmF3nxvhufcpUGKZNQI6 z9S9gjH40vjNjVDZKU9XHMl5v0gwr1KE//A9kfqIVjMFaDS5VwLVM0fodQ5ww5jy/pYR W7vJqwP7TbUuchqruP6RapRhdhiAnIR+37GizTbBrR/0gripwtGAuk6jFyKc/qnfAY6k poiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=scXNy7Kv0jk0u1cUOdecKgwqwG5sRFulap1lrncxuHo=; b=krXca3yrL5g1NkBNso3nsqrQzGSv+GqYEf6t4w3hh2XQPRq+BhfGsRJf25O6BWgww3 w0LFC8q1J3DTefPeOuwxX616tNNcu6MAS3y7EemVFYQKn449HpbqavVXkY3+8bIhpOSG /Y4FplDT7vPUFmkjubMxTc3rwe05RcM0H1tMYG2KQc686yaea54jpH0/9epiAYV4KaV5 jvD1tAtWIM05GuZ8sNwUfKcqn28Y3iSt0jz1eH+h5qBtwfB6qBqxgxg09C72DMvBh0QK Z0lhoorjlX1JqrE+AW3XNwu/nDhueWE+Lk5pg0SflntvMXEp81Ru/JEQdzk2XZrzshNh 0UwQ== X-Gm-Message-State: APjAAAVO0K/Q8t0q/5RGMPmlJxy2E5qbk1RAHpP8wwLevTWhVsRLHj/l ABoF6Yl/3YNy8WM5ICQEW1Y= X-Google-Smtp-Source: APXvYqxhAE3qGe17aHRIuRoz8i3iWKXSr8e07GEpkjAf4PZNHDYajF6mhq35eVbjNKcCGa5E96iAoQ== X-Received: by 2002:a1c:9904:: with SMTP id b4mr7585111wme.1.1559151819895; Wed, 29 May 2019 10:43:39 -0700 (PDT) Received: from localhost.localdomain ([5.102.238.208]) by smtp.gmail.com with ESMTPSA id k125sm31702wmb.34.2019.05.29.10.43.38 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 29 May 2019 10:43:39 -0700 (PDT) From: Amir Goldstein To: "Darrick J . Wong" Cc: Dave Chinner , Christoph Hellwig , linux-xfs@vger.kernel.org, Olga Kornievskaia , Luis Henriques , Al Viro , linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, ceph-devel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org Subject: [PATCH v3 06/13] vfs: introduce file_modified() helper Date: Wed, 29 May 2019 20:43:10 +0300 Message-Id: <20190529174318.22424-7-amir73il@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190529174318.22424-1-amir73il@gmail.com> References: <20190529174318.22424-1-amir73il@gmail.com> Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The combination of file_remove_privs() and file_update_mtime() is quite common in filesystem ->write_iter() methods. Modelled after the helper file_accessed(), introduce file_modified() and use it from generic_remap_file_range_prep(). Note that the order of calling file_remove_privs() before file_update_mtime() in the helper was matched to the more common order by filesystems and not the current order in generic_remap_file_range_prep(). Signed-off-by: Amir Goldstein --- fs/inode.c | 20 ++++++++++++++++++++ fs/read_write.c | 21 +++------------------ include/linux/fs.h | 2 ++ 3 files changed, 25 insertions(+), 18 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index df6542ec3b88..2885f2f2c7a5 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1899,6 +1899,26 @@ int file_update_time(struct file *file) } EXPORT_SYMBOL(file_update_time); +/* Caller must hold the file's inode lock */ +int file_modified(struct file *file) +{ + int err; + + /* + * Clear the security bits if the process is not being run by root. + * This keeps people from modifying setuid and setgid binaries. + */ + err = file_remove_privs(file); + if (err) + return err; + + if (likely(file->f_mode & FMODE_NOCMTIME)) + return 0; + + return file_update_time(file); +} +EXPORT_SYMBOL(file_modified); + int inode_needs_sync(struct inode *inode) { if (IS_SYNC(inode)) diff --git a/fs/read_write.c b/fs/read_write.c index b0fb1176b628..cec7e7b1f693 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1980,25 +1980,10 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, return ret; /* If can't alter the file contents, we're done. */ - if (!(remap_flags & REMAP_FILE_DEDUP)) { - /* Update the timestamps, since we can alter file contents. */ - if (!(file_out->f_mode & FMODE_NOCMTIME)) { - ret = file_update_time(file_out); - if (ret) - return ret; - } + if (!(remap_flags & REMAP_FILE_DEDUP)) + ret = file_modified(file_out); - /* - * Clear the security bits if the process is not being run by - * root. This keeps people from modifying setuid and setgid - * binaries. - */ - ret = file_remove_privs(file_out); - if (ret) - return ret; - } - - return 0; + return ret; } EXPORT_SYMBOL(generic_remap_file_range_prep); diff --git a/include/linux/fs.h b/include/linux/fs.h index e4d382c4342a..79ffa2958bd8 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2177,6 +2177,8 @@ static inline void file_accessed(struct file *file) touch_atime(&file->f_path); } +extern int file_modified(struct file *file); + int sync_inode(struct inode *inode, struct writeback_control *wbc); int sync_inode_metadata(struct inode *inode, int wait);