From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B76BCA9EA0 for ; Tue, 22 Oct 2019 13:37:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B6F421783 for ; Tue, 22 Oct 2019 13:37:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388435AbfJVNhc (ORCPT ); Tue, 22 Oct 2019 09:37:32 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:59244 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388388AbfJVNhc (ORCPT ); Tue, 22 Oct 2019 09:37:32 -0400 Received: from callcc.thunk.org (guestnat-104-133-0-98.corp.google.com [104.133.0.98] (may be forged)) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id x9MDbIXp024473 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 22 Oct 2019 09:37:19 -0400 Received: by callcc.thunk.org (Postfix, from userid 15806) id 52E2C420456; Tue, 22 Oct 2019 09:37:16 -0400 (EDT) Date: Tue, 22 Oct 2019 09:37:16 -0400 From: "Theodore Y. Ts'o" To: Eric Biggers Cc: linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, Satya Tangirala , Paul Crowley , Paul Lawrence , Jaegeuk Kim Subject: Re: [PATCH 2/3] ext4: add support for INLINE_CRYPT_OPTIMIZED encryption policies Message-ID: <20191022133716.GB23268@mit.edu> References: <20191021230355.23136-1-ebiggers@kernel.org> <20191021230355.23136-3-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191021230355.23136-3-ebiggers@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Oct 21, 2019 at 04:03:54PM -0700, Eric Biggers wrote: > From: Eric Biggers > > INLINE_CRYPT_OPTIMIZED encryption policies have special requirements > from the filesystem: > > - Inode numbers must never change, even if the filesystem is resized > - Inode numbers must be <= 32 bits > - File logical block numbers must be <= 32 bits You need to guarantee more than this; you also need to guarantee that the logical block number may not change. Fortunately, because the original per-file key scheme used a logical block tweak, we've prohibited this already, and we didn't relax this restriction for files encrpyted using DIRECT_KEY. So it's a requirement which we already meet, but we should document this requirement explicitly --- both here and also in Documentations/filesystems/fscrypt.rst. Otherwise, looks good. Feel free to add: Reviewed-by: Theodore Ts'o - Ted