From: Eric Sandeen Subject: Re: [PATCH e2fsprogs] Add ZFS detection to libblkid Date: Sat, 04 Apr 2009 08:04:17 -0500 Message-ID: <49D75AD1.7060101@redhat.com> References: <1212171647.7508.46.camel@localhost> <49D6C844.5070604@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "Theodore Ts'o" , linux-ext4@vger.kernel.org, Andreas Dilger To: "Ricardo M. Correia" Return-path: Received: from mx2.redhat.com ([66.187.237.31]:43309 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751550AbZDDNEX (ORCPT ); Sat, 4 Apr 2009 09:04:23 -0400 In-Reply-To: <49D6C844.5070604@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Eric Sandeen wrote: > Ricardo M. Correia wrote: >> This patch adds ZFS filesystem detection to libblkid. >> >> It probes for VDEV_BOOT_MAGIC in the first 2 ZFS labels in big-endia= n >> and little-endian formats. >> Unfortunately the probe table doesn't support probing from the end o= f >> the device, otherwise we could also probe in the 3rd and 4th labels = (in >> case the first 2 labels were accidentally overwritten).. >> >> Eventually we would set the =EF=BB=BFUUID from the ZFS pool GUID and= the LABEL tag >> from the pool name, but that requires parsing an XDR encoding of the= pool >> configuration which is not trivial. >=20 > Hi Ricardo: >=20 > I've got a bug on fedora now where a partition w/ zfs on it is being > recognized as ext3. VDEV_BOOT_MAGIC isn't anywhere in the first 1M o= f > the device, though an old ext3 superblock is intact. :( >=20 > # hexdump -C sda2-first-1M | grep "0c b1 07 b0 f5 02 00 00" > # hexdump -C sda2-first-1M | grep "00 00 02 f5 b0 07 b1 0c" > # >=20 > (so a plea - can you guys change mkfs to zero old signatures? maybe > 256k at the front & end of the device in question?) >=20 > there is apparently an uberblock signature in it though: >=20 > # hexdump -C sda2-first-1M | grep "0c b1 ba 00" > 00015e30 30 e8 ff ff 85 c0 5b 75 48 8b 06 35 0c b1 ba 00 >=20 > does blkid need more work here, I guess? And from another report, another user's zfs partition: # hexdump -C first_400K | grep "0c b1 07 b0 f5 02 00 00" # hexdump -C first_400K | grep "00 00 02 f5 b0 07 b1 0c" # hexdump -C first_400K | grep "0c b1 ba 00" 00015e30 30 e8 ff ff 85 c0 5b 75 48 8b 06 35 0c b1 ba 00 Should we be looking for 0x00babloc at offset 00015e30? Thanks, -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html