From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54944 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752276AbeAQNmg (ORCPT ); Wed, 17 Jan 2018 08:42:36 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w0HDdbJ7098495 for ; Wed, 17 Jan 2018 08:42:35 -0500 Received: from e06smtp13.uk.ibm.com (e06smtp13.uk.ibm.com [195.75.94.109]) by mx0a-001b2d01.pphosted.com with ESMTP id 2fj6jc3abg-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 17 Jan 2018 08:42:35 -0500 Received: from localhost by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 17 Jan 2018 13:42:33 -0000 From: Chandan Rajendra To: Eric Biggers Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu Subject: Re: [RFC PATCH 0/8] Ext4 encryption support for blocksize < pagesize Date: Wed, 17 Jan 2018 19:13:49 +0530 In-Reply-To: <20180117021020.GA4477@zzz.localdomain> References: <20180112141129.27507-1-chandan@linux.vnet.ibm.com> <20180117021020.GA4477@zzz.localdomain> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Message-Id: <4752190.CyFFPQ5jaq@localhost.localdomain> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wednesday, January 17, 2018 7:40:20 AM IST Eric Biggers wrote: > Hi Chandan, > > On Fri, Jan 12, 2018 at 07:41:21PM +0530, Chandan Rajendra wrote: > > This patchset implements code to support encryption of Ext4 filesystem > > instances that have blocksize less than pagesize. The patchset has > > been tested on both ppc64 and x86_64 machines. > > > > This patchset changes the prototype of the function > > fscrypt_encrypt_page(). I will make the relevant changes to the rest > > of the filesystems (e.g. f2fs) and post them in the next version of > > the patchset. > > > > Chandan Rajendra (8): > > ext4: use EXT4_INODE_ENCRYPT flag to detect encrypted bio > > fs/buffer.c: make some functions non-static > > ext4: decrypt all contiguous blocks in a page > > ext4: decrypt all boundary blocks when doing buffered write > > ext4: decrypt the block that needs to be partially zeroed > > ext4: encrypt blocks whose size is less than page size > > ext4: decrypt blocks whose size is less than page size > > ext4: enable encryption for blocksize less than page size > > > > Thanks for working on this! We've wanted this for a while (both so that it > works on PowerPC with a 64K PAGE_SIZE, and so that people can't screw up their > 1K blocksize filesystems by enabling the 'encrypt' flag), but no one ever got > around to it. And it's not easy! > > First, just a few notes that didn't fit into my comments for the individual > patches. > > Updating fscrypt_zeroout_range() seems to have been missed. Currently it > assumes block_size == PAGE_SIZE so it will need to be updated too. > > The file Documentation/filesystems/fscrypt.rst will also need to be updated, at > least to remove the following sentence: "Currently, only the case where the > filesystem block size is equal to the system's page size (usually 4096 bytes) is > supported.". Thanks a lot for the review comments. I will make sure to take care of them in the next version of the patchset. > > Also, on future versions of this patchset can you please also Cc > linux-fscrypt@vger.kernel.org? > Sure, I will do that. -- chandan