From patchwork Tue May 22 16:01:10 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chandan Rajendra X-Patchwork-Id: 918414 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-ext4-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.vnet.ibm.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40r0jh18XHz9s1d for ; Wed, 23 May 2018 02:00:40 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751929AbeEVQAh (ORCPT ); Tue, 22 May 2018 12:00:37 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:53264 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751872AbeEVQAd (ORCPT ); Tue, 22 May 2018 12:00:33 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w4MFxQ9x078020 for ; Tue, 22 May 2018 12:00:31 -0400 Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) by mx0b-001b2d01.pphosted.com with ESMTP id 2j4kwqgnwx-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 22 May 2018 12:00:31 -0400 Received: from localhost by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 22 May 2018 10:00:27 -0600 Received: from b03ledav003.gho.boulder.ibm.com (b03ledav003.gho.boulder.ibm.com [9.17.130.234]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w4MG0QpM12648898; Tue, 22 May 2018 09:00:26 -0700 Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 54ACA6A048; Tue, 22 May 2018 10:00:26 -0600 (MDT) Received: from localhost.localdomain.com (unknown [9.85.71.81]) by b03ledav003.gho.boulder.ibm.com (Postfix) with ESMTP id C9C8C6A03C; Tue, 22 May 2018 10:00:23 -0600 (MDT) From: Chandan Rajendra To: linux-fscrypt@vger.kernel.org Cc: Chandan Rajendra , ebiggers3@gmail.com, tytso@mit.edu, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [RFC PATCH V3 12/12] ext4: Enable encryption for blocksize less than page size Date: Tue, 22 May 2018 21:31:10 +0530 X-Mailer: git-send-email 2.9.5 In-Reply-To: <20180522160110.1161-1-chandan@linux.vnet.ibm.com> References: <20180522160110.1161-1-chandan@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18052216-0008-0000-0000-000009D5437A X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009066; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000261; SDB=6.01036073; UDB=6.00529991; IPR=6.00815201; MB=3.00021242; MTD=3.00000008; XFM=3.00000015; UTC=2018-05-22 16:00:29 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18052216-0009-0000-0000-000047660EED Message-Id: <20180522160110.1161-13-chandan@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-05-22_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1805220177 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Now that we have all the code to support encryption for block size less than page size scenario, this commit removes the conditional check in filesystem mount code. The commit also changes the support statement in Documentation/filesystems/fscrypt.rst to reflect the fact that encryption of filesystems with blocksize less than page size now works. Signed-off-by: Chandan Rajendra --- Documentation/filesystems/fscrypt.rst | 14 +++++++------- fs/ext4/super.c | 7 ------- 2 files changed, 7 insertions(+), 14 deletions(-) diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index cfbc18f..6f0827c 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -202,13 +202,13 @@ modes are not currently supported because of the difficulty of dealing with ciphertext expansion. For file contents, each filesystem block is encrypted independently. -Currently, only the case where the filesystem block size is equal to -the system's page size (usually 4096 bytes) is supported. With the -XTS mode of operation (recommended), the logical block number within -the file is used as the IV. With the CBC mode of operation (not -recommended), ESSIV is used; specifically, the IV for CBC is the -logical block number encrypted with AES-256, where the AES-256 key is -the SHA-256 hash of the inode's data encryption key. +Starting from Linux kernel 4.18, encryption of filesystems with block +size less than system's page size is supported. With the XTS mode of +operation (recommended), the logical block number within the file is +used as the IV. With the CBC mode of operation (not recommended), +ESSIV is used; specifically, the IV for CBC is the logical block +number encrypted with AES-256, where the AES-256 key is the SHA-256 +hash of the inode's data encryption key. For filenames, the full filename is encrypted at once. Because of the requirements to retain support for efficient directory lookups and diff --git a/fs/ext4/super.c b/fs/ext4/super.c index c40dda6..ebfbeea 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4161,13 +4161,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } } - if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) && - (blocksize != PAGE_SIZE)) { - ext4_msg(sb, KERN_ERR, - "Unsupported blocksize for fs encryption"); - goto failed_mount_wq; - } - if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) && !ext4_has_feature_encrypt(sb)) { ext4_set_feature_encrypt(sb);