From owner-svn-src-head@freebsd.org Thu Dec 10 15:10:51 2015 Return-Path: Delivered-To: svn-src-head@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 33D459D6E90; Thu, 10 Dec 2015 15:10:51 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from bigwig.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 16E7F1ED5; Thu, 10 Dec 2015 15:10:51 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from ralph.baldwin.cx (c-73-231-226-104.hsd1.ca.comcast.net [73.231.226.104]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 1ED54B986; Thu, 10 Dec 2015 10:10:50 -0500 (EST) From: John Baldwin To: "Andrey V. Elsukov" Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r292057 - in head/sys: boot/common geom/part Date: Thu, 10 Dec 2015 07:07:41 -0800 Message-ID: <3064443.9SoIZWyLLV@ralph.baldwin.cx> User-Agent: KMail/4.14.3 (FreeBSD/10.2-STABLE; KDE/4.14.3; amd64; ; ) In-Reply-To: <201512101035.tBAAZ7fj064953@repo.freebsd.org> References: <201512101035.tBAAZ7fj064953@repo.freebsd.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (bigwig.baldwin.cx); Thu, 10 Dec 2015 10:10:50 -0500 (EST) X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Dec 2015 15:10:51 -0000 On Thursday, December 10, 2015 10:35:07 AM Andrey V. Elsukov wrote: > Author: ae > Date: Thu Dec 10 10:35:07 2015 > New Revision: 292057 > URL: https://svnweb.freebsd.org/changeset/base/292057 > > Log: > Make detection of GPT a bit more reliable. > > When we are detecting a partition table and didn't find PMBR, try to > read backup GPT header from the last sector and if it is correct, > assume that we have GPT. One thing that your commit message did not make clear: Does this only detect as valid if no other partition scheme claims the disk? That is, if I overwrite a previously GPT-partitioned disk with a different scheme (e.g. MBR), will that disk now probe as GPT instead of the new scheme? If so, this is broken and needs to be reverted. If this somehow does a "low" priority probe and only kicks in if no other scheme claims the disk, then this is ok, but you should probably have said so in the commit message. -- John Baldwin