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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 6B756CA9ECF for ; Thu, 31 Oct 2019 16:46:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D26C20873 for ; Thu, 31 Oct 2019 16:46:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728718AbfJaQqO (ORCPT ); Thu, 31 Oct 2019 12:46:14 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:35407 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728714AbfJaQqO (ORCPT ); Thu, 31 Oct 2019 12:46:14 -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 x9VGjo7m016231 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 31 Oct 2019 12:45:51 -0400 Received: by callcc.thunk.org (Postfix, from userid 15806) id 6335E420456; Thu, 31 Oct 2019 12:45:50 -0400 (EDT) Date: Thu, 31 Oct 2019 12:45:50 -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, Douglas Anderson , Gwendal Grignou , Ryo Hashimoto , groeck@chromium.org, apronin@chromium.org, sukhomlinov@google.com, Chao Yu Subject: Re: [PATCH v2] Revert "ext4 crypto: fix to check feature status before get policy" Message-ID: <20191031164550.GF16197@mit.edu> References: <20191030215138.224671-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191030215138.224671-1-ebiggers@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org On Wed, Oct 30, 2019 at 02:51:38PM -0700, Eric Biggers wrote: > From: Douglas Anderson > > This reverts commit 0642ea2409f3 ("ext4 crypto: fix to check feature > status before get policy"). > > The commit made a clear and documented ABI change that is not backward > compatible. There exists userspace code [1][2] that relied on the old > behavior and is now broken. > > While we could entertain the idea of updating the userspace code to > handle the ABI change, it's my understanding that in general ABI > changes that break userspace are frowned upon (to put it nicely). The rule is that if someone complains, we have to revert. Douglas's email counts as a complaint, so we should revert. That being said, if ChromeOS (userspace) changes to using /sys/fs/ext4/features/encryption to determine whether or not the kernel supports encryption, then we can in the future change the error code to make things consistent with f2fs. This looks good, I'll pull it into ext4 git tree. - Ted