From owner-svn-src-head@freebsd.org Thu Dec 10 17:39:04 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 602D59D7927; Thu, 10 Dec 2015 17:39:04 +0000 (UTC) (envelope-from ae@FreeBSD.org) Received: from mx2.freebsd.org (mx2.freebsd.org [IPv6:2001:1900:2254:206a::19:2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mx2.freebsd.org", Issuer "Gandi Standard SSL CA 2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4F2171E0D; Thu, 10 Dec 2015 17:39:04 +0000 (UTC) (envelope-from ae@FreeBSD.org) Received: from butcher-nb.yandex.net (freefall.freebsd.org [IPv6:2001:1900:2254:206c::16:87]) by mx2.freebsd.org (Postfix) with ESMTP id 289186B48F; Thu, 10 Dec 2015 17:39:01 +0000 (UTC) (envelope-from ae@FreeBSD.org) Subject: Re: svn commit: r292057 - in head/sys: boot/common geom/part To: John Baldwin References: <201512101035.tBAAZ7fj064953@repo.freebsd.org> <3064443.9SoIZWyLLV@ralph.baldwin.cx> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org From: "Andrey V. Elsukov" Message-ID: <5669B8A1.5000306@FreeBSD.org> Date: Thu, 10 Dec 2015 20:38:41 +0300 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <3064443.9SoIZWyLLV@ralph.baldwin.cx> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="2OgRfbmmlkI60TT3n5USCoSBI37a9hwFu" 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 17:39:04 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --2OgRfbmmlkI60TT3n5USCoSBI37a9hwFu Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 10.12.15 18:07, John Baldwin wrote: > 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. >> =20 >> 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. >=20 > One thing that your commit message did not make clear: >=20 > 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 th= is > somehow does a "low" priority probe and only kicks in if no other schem= e > claims the disk, then this is ok, but you should probably have said so = in > the commit message. Hi, GEOM_PART uses different priorities between schemes when does probing. In your case MBR will have greater priority and MBR will be detected in result. As it worked before. This change only affects the case, when there is no MBR signature at all, but we have valid backup GPT header. --=20 WBR, Andrey V. Elsukov --2OgRfbmmlkI60TT3n5USCoSBI37a9hwFu Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJWabihAAoJEAHF6gQQyKF6ESYH/Rpkk9bzVeL5/HhEKhOR9Ko+ WxQRo3wDxOHORZxuRMq2tOeigHFsWr0XLniFio9J42VUSqBXR18Drx+3+eWelTHJ ICLnR5cLwpJNPlErkdsesZCgRZe4QIsbo+0luNs62wLORuHtvPUl4nEi9TvuhQUT w3R16ShTMuQ9D5CuIdFdAAx/TyCnCIzt37NZt8sVrfb6JH5lNQk3yTPqwJ128p2L XieIl+EgWx10XdfRykgKumIa1XzHzkkgeELr2FGp2qrHJLFEvERZiFlkzCK55qx/ rsNEbRyCYmxHegcu3rLH/DijdvD7BykyuVGLWLqn7xXjc1fg53Rto7J++aas18k= =kX3A -----END PGP SIGNATURE----- --2OgRfbmmlkI60TT3n5USCoSBI37a9hwFu--