From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net ([212.227.17.20]:49227 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751728AbaJ0BY3 (ORCPT ); Sun, 26 Oct 2014 21:24:29 -0400 Received: from marcec.fritz.box ([93.181.44.4]) by mail.gmx.com (mrgmx103) with ESMTPSA (Nemesis) id 0LvlWS-1Y9ztv1TZM-017Y12 for ; Mon, 27 Oct 2014 02:24:27 +0100 Date: Mon, 27 Oct 2014 02:24:15 +0100 From: Marc Joliet To: linux-btrfs@vger.kernel.org Subject: Re: Poll: time to switch skinny-metadata on by default? Message-ID: <20141027022415.14940745@marcec.fritz.box> In-Reply-To: References: <20141016113337.GC22943@twin.jikos.cz> <20141020163403.GW22943@twin.jikos.cz> <20141025142458.5d96970b@marcec> <64867638-EADF-4258-ACD7-BC33014B3DA9@colorremedies.com> Reply-To: linux-btrfs@vger.kernel.org MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/52l8thtaJDpcwiXFXF9gq9X"; protocol="application/pgp-signature" Sender: linux-btrfs-owner@vger.kernel.org List-ID: --Sig_/52l8thtaJDpcwiXFXF9gq9X Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Am Sat, 25 Oct 2014 14:35:33 -0600 schrieb Chris Murphy : >=20 > On Oct 25, 2014, at 2:33 PM, Chris Murphy wrote: >=20 > >=20 > > On Oct 25, 2014, at 6:24 AM, Marc Joliet wrote: > >>=20 > >> First of all: does grub2 support booting from a btrfs file system with > >> skinny-metadata, or is it irrelevant? > >=20 > > Seems plausible if older kernels don't understand skinny-metadata, that= GRUB2 won't either. So I just tested it with grub2-2.02-0.8.fc21 and it wo= rks. I'm surprised, actually. >=20 > I don't understand the nature of the incompatibility with older kernels. = Can they not mount a Btrfs volume even as ro? If so then I'd expect GRUB to= have a problem, so I'm going to guess that maybe a 3.9 or older kernel cou= ld ro mount a Btrfs volume with skinny extents and the incompatibility is w= riting. That sounds plausible, though I hope for a definitive answer. (FWIW, I originally asked because I couldn't find any commits to grub2 related to sk= inny metadata; the updates to the btrfs driver were fairly sparse.) --=20 Marc Joliet -- "People who think they know everything really annoy those of us who know we don't" - Bjarne Stroustrup --Sig_/52l8thtaJDpcwiXFXF9gq9X Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBAgAGBQJUTZ7JAAoJEL/Q5oYsiHj0rH0P/13HSDQzEYRCkWWEyxaeQT3a hUvM3gTiP8T0qHcYWJZgZgwTKDHk3W0xU9tXiV7VjnkU7mTFbpyRhT9ORv2Aa+tx QMsBJT05iKRU7ErjxFsu3jF3Wegn7engem87IaPsEOhm5T/VrtozVfx2cGVCMaw5 tjr3QEYU97vLhwMf+FsMvVRA2r5xbehPsUwv5q3y/EAMVGYGnwmoMQqt06Pwd33f hKxbqij/E/bi2at3m0QOIMiiO0gYsbx97nWeHHioH1XonNjjCUILnOPWcfTVwFPL VihhpS82BAD6PDQaoTOVNFhelgK2EJOvZXzEL/lZy4WLhEeGqQqFhppz32llFpZ1 GPaZbpcJ9nEoMjP+weTga8pBDymaac+tgIBL8wkCuFWIh58DpaHYuxdBjVahWtIx pxISo0jvzZKS5ImZQO3Ml3Jy1I4W87pB5+pRCY364qCz1QlCO1xr442zI8C3oCBY fy3wtGhlO1KT58RDrNBr0UQ2sTKfLyqaNQXrOwg2mDbshN8EwwJvFyqNTX3Rsws9 7dAcVtn1xJagnKLHae3dCchFqPSIXGJDHYNCDzLlXvp5LV9UxsPbugv209g+wwoC H716u278rMHET2hMpbX6mHe25RrnA7VCT2aGGRNbHQkGeGKM78uqEyw13K7uh7c8 Z9SGjE4ACpAyBZaR3Qx1 =faEf -----END PGP SIGNATURE----- --Sig_/52l8thtaJDpcwiXFXF9gq9X--