From patchwork Fri Jun 28 18:34:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 11023185 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 01838112C for ; Fri, 28 Jun 2019 18:35:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C24DF28346 for ; Fri, 28 Jun 2019 18:35:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B5C5E2846C; Fri, 28 Jun 2019 18:35:35 +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=-5.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from aserp2120.oracle.com (aserp2120.oracle.com [141.146.126.78]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 3AD5928346 for ; Fri, 28 Jun 2019 18:35:35 +0000 (UTC) Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5SIYLoj027892; Fri, 28 Jun 2019 18:35:10 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : date : message-id : in-reply-to : references : mime-version : cc : subject : list-id : list-unsubscribe : list-archive : list-post : list-help : list-subscribe : content-type : content-transfer-encoding : sender; s=corp-2018-07-02; bh=IzffXaVhodc+ZwZLvJP69Qva32V8jc2x4zVxENHM5eU=; b=eAj00YJusZ+Bw7uS0aITAQgQt+IA3RqPjx0Z1wFZR8liPT8khSVgHYbZ+hYBa1DNcoNp DEf0M7BNwXTvyvlgRlQOMAXRye8F2jtG2fSFFdkxTOQeJgU+5WQIICnVzMbqZtGrRhKe Dn0TShX89fK4q+mprnBg191ss3kNFN+HnnCC+sgO2oTvR2J8nwBbkOPKdrLkM+damVQy 1NZwO93fIw/TDzF6gZuTLHIwtoN8gm8FXRMehsZLHUF7OkyTraKQ/nFaynXAO1iwz3d8 xBkRJYsw+qvAH7qs5mYK2fdakXFW5aZ7QJjylRxPxCIV118OQX5LW9zo/WCconvSsmc5 IQ== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by aserp2120.oracle.com with ESMTP id 2t9c9q72sp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 28 Jun 2019 18:35:10 +0000 Received: from oss.oracle.com (oss-old-reserved.oracle.com [137.254.22.2]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x5SIZ9Sl025734 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 28 Jun 2019 18:35:09 GMT Received: from localhost ([127.0.0.1] helo=lb-oss.oracle.com) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1hgviH-0003YI-5T; Fri, 28 Jun 2019 11:35:09 -0700 Received: from userp3020.oracle.com ([156.151.31.79]) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1hgvi5-0003Tb-0J for ocfs2-devel@oss.oracle.com; Fri, 28 Jun 2019 11:34:57 -0700 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5SIXemZ001136 for ; Fri, 28 Jun 2019 18:34:56 GMT Authentication-Results: aserp3010.oracle.com; spf=pass smtp.mailfrom=darrick.wong@oracle.com; dmarc=pass header.from=oracle.com Received: from pps.reinject (localhost [127.0.0.1]) by userp3020.oracle.com with ESMTP id 2tat7e3gaa-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Fri, 28 Jun 2019 18:34:56 +0000 Received: from userp3020.oracle.com (userp3020.oracle.com [127.0.0.1]) by pps.reinject (8.16.0.27/8.16.0.27) with SMTP id x5SIYuM7003117 for ; Fri, 28 Jun 2019 18:34:56 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3020.oracle.com with ESMTP id 2tat7e3ga7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 28 Jun 2019 18:34:56 +0000 Received: from abhmp0002.oracle.com (abhmp0002.oracle.com [141.146.116.8]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x5SIYsCq029052; Fri, 28 Jun 2019 18:34:54 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 28 Jun 2019 11:34:54 -0700 From: "Darrick J. Wong" To: matthew.garrett@nebula.com, yuchao0@huawei.com, tytso@mit.edu, darrick.wong@oracle.com, ard.biesheuvel@linaro.org, josef@toxicpanda.com, hch@infradead.org, clm@fb.com, adilger.kernel@dilger.ca, viro@zeniv.linux.org.uk, jack@suse.com, dsterba@suse.com, jaegeuk@kernel.org, jk@ozlabs.org Date: Fri, 28 Jun 2019 11:34:51 -0700 Message-ID: <156174689192.1557469.17945809794748607270.stgit@magnolia> In-Reply-To: <156174687561.1557469.7505651950825460767.stgit@magnolia> References: <156174687561.1557469.7505651950825460767.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Cc: linux-efi@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, reiserfs-devel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-mtd@lists.infradead.org, ocfs2-devel@oss.oracle.com, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, devel@lists.orangefs.org Subject: [Ocfs2-devel] [PATCH 2/4] vfs: flush and wait for io when setting the immutable flag via SETFLAGS X-BeenThere: ocfs2-devel@oss.oracle.com X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: ocfs2-devel-bounces@oss.oracle.com Errors-To: ocfs2-devel-bounces@oss.oracle.com X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9302 signatures=668688 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906280210 X-Virus-Scanned: ClamAV using ClamSMTP From: Darrick J. Wong When we're using FS_IOC_SETFLAGS to set the immutable flag on a file, we need to ensure that userspace can't continue to write the file after the file becomes immutable. To make that happen, we have to flush all the dirty pagecache pages to disk to ensure that we can fail a page fault on a mmap'd region, wait for pending directio to complete, and hope the caller locked out any new writes by holding the inode lock. Signed-off-by: Darrick J. Wong --- fs/inode.c | 21 +++++++++++++++++++-- include/linux/fs.h | 11 +++++++++++ 2 files changed, 30 insertions(+), 2 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index f08711b34341..65a412af3ffb 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2193,7 +2193,8 @@ EXPORT_SYMBOL(current_time); /* * Generic function to check FS_IOC_SETFLAGS values and reject any invalid - * configurations. + * configurations. Once we're done, prepare the inode for whatever changes + * are coming down the pipeline. * * Note: the caller should be holding i_mutex, or else be sure that they have * exclusive access to the inode structure. @@ -2201,6 +2202,8 @@ EXPORT_SYMBOL(current_time); int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, unsigned int flags) { + int ret; + /* * The IMMUTABLE and APPEND_ONLY flags can only be changed by * the relevant capability. @@ -2211,7 +2214,21 @@ int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, !capable(CAP_LINUX_IMMUTABLE)) return -EPERM; - return 0; + /* + * Now that we're done checking the new flags, flush all pending IO and + * dirty mappings before setting S_IMMUTABLE on an inode via + * FS_IOC_SETFLAGS. If the flush fails we'll clear the flag before + * returning error. + */ + if (!S_ISREG(inode->i_mode) || IS_IMMUTABLE(inode) || + !(flags & FS_IMMUTABLE_FL)) + return 0; + + inode_set_flags(inode, S_IMMUTABLE, S_IMMUTABLE); + ret = inode_drain_writes(inode); + if (ret) + inode_set_flags(inode, 0, S_IMMUTABLE); + return ret; } EXPORT_SYMBOL(vfs_ioc_setflags_prepare); diff --git a/include/linux/fs.h b/include/linux/fs.h index 91482ab4556a..0efe749de577 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3567,4 +3567,15 @@ static inline void simple_fill_fsxattr(struct fsxattr *fa, __u32 xflags) fa->fsx_xflags = xflags; } +/* + * Flush file data before changing attributes. Caller must hold any locks + * required to prevent further writes to this file until we're done setting + * flags. + */ +static inline int inode_drain_writes(struct inode *inode) +{ + inode_dio_wait(inode); + return filemap_write_and_wait(inode->i_mapping); +} + #endif /* _LINUX_FS_H */