From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: util-linux-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:22300 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752357Ab2KEJpt (ORCPT ); Mon, 5 Nov 2012 04:45:49 -0500 Date: Mon, 5 Nov 2012 10:45:46 +0100 From: Karel Zak To: util-linux@vger.kernel.org, grawity@gmail.com Subject: Re: [bug] incorrect GPT entry validation? Message-ID: <20121105094546.GA365@x2.net.home> References: <20121103183511.GO482@rampage> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20121103183511.GO482@rampage> Sender: util-linux-owner@vger.kernel.org List-ID: On Sat, Nov 03, 2012 at 02:35:11PM -0400, Dave Reisner wrote: > Hi, > > A user reported problems with libblkid incorrectly reporting (or not > reporting) tags for some partitions on a GPT formatted disk. I was able > to reproduce it: > > - created a 10G disk on a VM > - initialized it with GPT (using gdisk), created 5 entries > - formatted each of them with ext4 > > blkid correctly reads the first 2 entries on the disk, but then starts > reporting corrupted GPT entries (seen via LIBBLKID_DEBUG=0xffff): > > https://dev.archlinux.org/~dreisner/blkid_bad.txt It would be nice to have the debug output. Please, send me begin of the device: # dd if=/dev/vdd of=img count=1 bs=1Mib # gzip -9 img > It's interesting to note that blkid will _always_ read 2 entries before > reporting corruption, i.e. Hmm... sounds like in-memory buffer corruption libblkid caches the data from the device). > # blkid -c /dev/null /dev/vdd{4,5,2} Are you able to reproduce the bug by "blkid -p -o udev" ? Karel -- Karel Zak http://karelzak.blogspot.com