From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chandan Rajendra Subject: [RFC PATCH 07/10] fsverity: Add call back to determine readpage limit Date: Mon, 18 Feb 2019 15:34:30 +0530 Message-ID: <20190218100433.20048-8-chandan@linux.ibm.com> References: <20190218100433.20048-1-chandan@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1gvfn5-0000s2-87 for linux-f2fs-devel@lists.sourceforge.net; Mon, 18 Feb 2019 10:04:47 +0000 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]) by sfi-mx-4.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) id 1gvfmy-00EUQu-V9 for linux-f2fs-devel@lists.sourceforge.net; Mon, 18 Feb 2019 10:04:47 +0000 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1IA3trf060326 for ; Mon, 18 Feb 2019 05:04:35 -0500 Received: from e35.co.us.ibm.com (e35.co.us.ibm.com [32.97.110.153]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qqsn8u0gk-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 18 Feb 2019 05:04:35 -0500 Received: from localhost by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 18 Feb 2019 10:04:34 -0000 In-Reply-To: <20190218100433.20048-1-chandan@linux.ibm.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fscrypt@vger.kernel.org Cc: tytso@mit.edu, ebiggers@kernel.org, Chandan Rajendra , adilger.kernel@dilger.ca, jaegeuk@kernel.org Ext4 and F2FS store verity metadata beyond i_size. This commit adds a call back pointer to "struct fsverity_operations" which helps in determining the the real file size limit upto which data can be read from the file. This call back will be required in order to get do_mpage_readpage() to read files having verity metadata appended beyond i_size. Signed-off-by: Chandan Rajendra --- fs/ext4/super.c | 18 ++++++++++++++++++ include/linux/fsverity.h | 1 + 2 files changed, 19 insertions(+) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 2d7781ab6824..4493ddc357c6 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1428,6 +1428,23 @@ static struct page *ext4_read_verity_metadata_page(struct inode *inode, return read_mapping_page(inode->i_mapping, index, NULL); } +static loff_t ext4_readpage_limit(struct inode *inode) +{ +#ifdef CONFIG_FS_VERITY + if (IS_VERITY(inode)) { + if (inode->i_verity_info) + /* limit to end of metadata region */ + return fsverity_full_i_size(inode); + /* + * fsverity_info is currently being set up and no user reads are + * allowed yet. It's easiest to just not enforce a limit yet. + */ + return inode->i_sb->s_maxbytes; + } +#endif + return i_size_read(inode); +} + static bool ext4_verity_required(struct inode *inode, pgoff_t index) { if (index < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT)) @@ -1441,6 +1458,7 @@ static const struct fsverity_operations ext4_verityops = { .get_metadata_end = ext4_get_verity_metadata_end, .read_metadata_page = ext4_read_verity_metadata_page, .verity_required = ext4_verity_required, + .readpage_limit = ext4_readpage_limit, }; #endif /* CONFIG_FS_VERITY */ diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h index b83712d6c79a..fc8113acbbfe 100644 --- a/include/linux/fsverity.h +++ b/include/linux/fsverity.h @@ -19,6 +19,7 @@ struct fsverity_operations { int (*get_metadata_end)(struct inode *inode, loff_t *metadata_end_ret); struct page *(*read_metadata_page)(struct inode *inode, pgoff_t index); bool (*verity_required)(struct inode *inode, pgoff_t index); + loff_t (*readpage_limit)(struct inode *inode); }; #ifdef CONFIG_FS_VERITY -- 2.19.1