From owner-svn-src-all@freebsd.org Mon Aug 22 08:22:50 2016 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id E7A8ABB85C7; Mon, 22 Aug 2016 08:22:50 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citapm.icyb.net.ua (citapm.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 693EB1F03; Mon, 22 Aug 2016 08:22:49 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citapm.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id LAA27617; Mon, 22 Aug 2016 11:22:47 +0300 (EEST) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1bbkVL-000PI7-3H; Mon, 22 Aug 2016 11:22:47 +0300 Subject: Re: svn commit: r303630 - in head/sys: boot/zfs cddl/boot/zfs To: Allan Jude , src-committers@FreeBSD.org, svn-src-all@FreeBSD.org, svn-src-head@FreeBSD.org, Toomas Soome References: <201608011937.u71JbhGD055117@repo.freebsd.org> From: Andriy Gapon Message-ID: <893dc513-69b4-ae9e-e3d3-2d2d02d04348@FreeBSD.org> Date: Mon, 22 Aug 2016 11:21:45 +0300 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <201608011937.u71JbhGD055117@repo.freebsd.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Aug 2016 08:22:51 -0000 On 01/08/2016 22:37, Allan Jude wrote: > Author: allanjude > Date: Mon Aug 1 19:37:43 2016 > New Revision: 303630 > URL: https://svnweb.freebsd.org/changeset/base/303630 > > Log: > Make boot code and loader check for unsupported ZFS feature flags > > OpenZFS uses feature flags instead of a zpool version number to track > features since the split from Oracle. In addition to avoiding confusion > on ZFS vs OpenZFS version numbers, this also allows features to be added > to different operating systems that use OpenZFS in different order. > > The previous zfs boot code (gptzfsboot) and loader (zfsloader) blindly > tries to read the pool, and if failed provided only a vague error message. > > With this change, both the boot code and loader check the MOS features > list in the ZFS label and compare it against the list of features that > the loader supports. If any unsupported feature is active, the pool is > not considered as a candidate for booting, and a helpful diagnostic > message is printed to the screen. Features that are merely enabled via > zpool upgrade, but not in use, do not block booting from the pool. > > Submitted by: Toomas Soome > Reviewed by: delphij, mav > Relnotes: yes > Differential Revision: https://reviews.freebsd.org/D6857 It is really great to get a helpful diagnostic message when an unsupported feature is seen. Thank you for that! But I would prefer that the check is done on a filesystem level, not on a pool level. That is, I would like to be able to enable features that are not supported by ZFS boot chain on a boot pool as long as I do not enable such features on a boot filesystem. E.g., the large blocks support could be one of such features. And, as I've said in another email, I really do not think that we should strive to support all possible (non-essential) ZFS features in the ZFS boot chain. -- Andriy Gapon