From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from frost.carfax.org.uk ([85.119.82.111]:37809 "EHLO frost.carfax.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752518AbaIBMNw (ORCPT ); Tue, 2 Sep 2014 08:13:52 -0400 Date: Tue, 2 Sep 2014 13:13:49 +0100 From: Hugo Mills To: Holger =?iso-8859-1?Q?Hoffst=E4tte?= Cc: linux-btrfs@vger.kernel.org Subject: Re: Btrfs-progs-3.16: fs metadata is both single and dup? Message-ID: <20140902121349.GF18897@carfax.org.uk> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="YkJPYEFdoxh/AXLE" In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-ID: --YkJPYEFdoxh/AXLE Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Sep 02, 2014 at 12:05:33PM +0000, Holger Hoffst=E4tte wrote: >=20 > I updated to progs-3.16 and noticed during testing: >=20 > root>losetup=20 > NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE > /dev/loop0 0 0 0 0 /tmp/img >=20 > root>mkfs.btrfs -f /dev/loop0 > Btrfs v3.16 > See http://btrfs.wiki.kernel.org for more information. >=20 > Performing full device TRIM (8.00GiB) ... > Turning ON incompat feature 'extref': increased hardlink limit per file= =20 > to 65536 > fs created label (null) on /dev/loop0 > nodesize 16384 leafsize 16384 sectorsize 4096 size 8.00GiB > root>mkdir /tmp/btrfs > root>mount /dev/loop0 /tmp/btrfs=20 >=20 > All fine until here.. >=20 > root>btrfs filesystem df /tmp/btrfs=20 > Data, single: total=3D8.00MiB, used=3D64.00KiB > System, DUP: total=3D8.00MiB, used=3D16.00KiB > System, single: total=3D4.00MiB, used=3D0.00 > Metadata, DUP: total=3D409.56MiB, used=3D112.00KiB > Metadata, single: total=3D8.00MiB, used=3D0.00 Note that the "single" chunks are empty, and will remain so. [snip] > So where does the confusing initial display come from? I'm running this= =20 > against a (very patched) 3.14.17, but don't remember ever seeing this=20 > with btrfs-progs-3.14.2. Your memory is faulty, I'm afraid. It's always done that -- at least since I started using btrfs, several years ago. I believe it comes from mkfs creating a trivial basic filesystem (with the single profiles), and then setting enough flags on it that the kernel can bootstrap it with the desired chunks in it -- but I may be wrong about that. Hugo. --=20 =3D=3D=3D Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk= =3D=3D=3D PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- Normaliser unix c'est comme pasteuriser le Camembert --- =20 --YkJPYEFdoxh/AXLE Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIVAwUBVAW0fFheFHXiqx3kAQItwA//bp8CRj+9sZeCCb33a3DIHffoPZrYRs5q huE9KrJaUFAfiHTpnBEGLWqwLTLVDTs5voK5b5p9jwiWouC9d991vkbnf7zqJAv+ XGs4gUzsjivzpC+BqjnIGlLPB4Z/N//Bc60CKpc+mEEDdePZojJQDgm1VPp1PCN+ ZwQaAw5VSet2fhkT0IS0Lf+DyaOvHHbPDWUTCR6SEBpP9me1NzUU4stOXjuE6UhL Ob8wUA6YrOtrWideX/T1bGr6EvQwyTYZFAUvNBtt6d6gQKTJFYerTzV7q392tBBC sU3CpEYd3nmaheMDFUg/b11fGCralE7xXM6VzQt7jg3V1JSi7m9d0Hq/cO/OPpQh szDY2eq8tg1jAFsS4RPLzb0GG7nKDlBn+97QRquFfFokgtucEVgniAG5v9/um18Q dKvHlyUx0H3YWMZO6QZAeFCZCkGBRfRgkpn4FcY64hlqTxkhM7Bis9cTLwUMFQ56 oOe/gZwMs4vWhbcEWwlRwVTcXtK7aRewKyW4aIWza5yFutFeYXRaI3XG3XIPgU4W 5/z2VAiIERmaSar+8ju+LNMpGEhZeHLLIJPMH6lqu9JSYOYyUYJQZpbltQ1hSRKY 7xpvzVqpUExiEZOoLrGXBUnGRnbRtVEF7/dBSJljX2MOmbEKr6dFTN4aNPtUyvx+ k/UgX5/uYss= =mfIA -----END PGP SIGNATURE----- --YkJPYEFdoxh/AXLE--