[Bug 1579609] Re: os-prober bug resulting in possible FS corruption

Tue Dec 6 16:21:14 UTC 2016

The patch has been modified as per IRC communication with cyphermox

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Title:
  os-prober bug resulting in possible FS corruption

Status in os-prober package in Ubuntu:
  In Progress
Status in os-prober source package in Xenial:
  In Progress

Bug description:
  [Impact]

  This bug generate some warnings in system log and in some cases it
  also might cause FS corruption as seen with a user using MySQL for his
  Openstack env.

  [Test Case]

  As of today, there is 3 reported way to reproduce the problem so far :

  #1

  Reboot system
  $ sudo update-grub
  then check the log again:
  $ journalctl -p err -b -k --no-pager

  #2
  Placing a VM under IO load (basically just ran dd if=/dev/vda of=/dev/null) and then ran update-grub on the hypervisor host.

  #3
  Simply run: os-prober, on an hypervisor some VM with LVM storage backend.

  [Regression Potential]

  none expected
  A test package has been tested by several users experiencing the issue, and positives feedbacks has been provided in all cases.

  [Other Info]

  Workaround:
  - Disable os-prober
  - Uninstall os-prober

  Debian bug:
  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=788062
  (Merged 648208 788062 806273 810121)

  Debian Patch:
  https://bugs.debian.org/cgi-bin/bugreport.cgi?att=1;bug=806273;filename=v2-0001-use-grub-mount-as-the-sole-source-of-partition-pr.patch;msg=30

  [Original Description]

  According to this it should be fixed
  https://bugs.launchpad.net/ubuntu/+source/os-
  prober/+bug/1374759/comments/32

  But on my system I intended to install on /dev/sdb1 and noticed these
  warning message in my system log.

  Steps to reproduce:

  1. reboot system
  2. $ sudo update-grub
  then check the log again:
  $ journalctl -p err -b -k --no-pager

  -- Logs begin at Sun 2016-05-08 10:47:49 CST, end at Mon 2016-05-09 11:42:04 CST. --
  May 08 10:47:50 X230 kernel: [drm:intel_set_pch_fifo_underrun_reporting [i915]] *ERROR* uncleared pch fifo underrun on pch transcoder A
  May 08 10:47:50 X230 kernel: [drm:intel_pch_fifo_underrun_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
  May 08 10:55:34 X230 kernel: EXT4-fs (sdb1): VFS: Can't find ext4 filesystem
  May 08 10:55:34 X230 kernel: EXT4-fs (sdb1): VFS: Can't find ext4 filesystem
  May 08 10:55:34 X230 kernel: EXT4-fs (sdb1): VFS: Can't find ext4 filesystem
  May 08 10:55:34 X230 kernel: FAT-fs (sdb1): invalid media value (0x7d)
  May 08 10:55:34 X230 kernel: squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on sdb1
  May 08 10:55:34 X230 kernel: FAT-fs (sdb1): invalid media value (0x7d)
  May 08 10:55:34 X230 kernel: qnx4: no qnx4 filesystem (no root dir).
  May 08 10:55:34 X230 kernel: ufs: You didn't specify the type of your ufs filesystem

                               mount -t ufs -o
  ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-
  cd|openstep ...

                               >>>WARNING<<< Wrong ufstype may corrupt your filesystem, default is ufstype=old
  May 08 10:55:34 X230 kernel: ufs: ufs_fill_super(): bad magic number
  May 08 10:55:34 X230 kernel: EXT4-fs (sdb4): VFS: Can't find ext4 filesystem
  May 08 10:55:34 X230 kernel: EXT4-fs (sdb4): VFS: Can't find ext4 filesystem
  May 08 10:55:34 X230 kernel: EXT4-fs (sdb4): VFS: Can't find ext4 filesystem
  May 08 10:55:34 X230 kernel: FAT-fs (sdb4): bogus number of reserved sectors
  May 08 10:55:34 X230 kernel: squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on sdb4
  May 08 10:55:34 X230 kernel: FAT-fs (sdb4): bogus number of reserved sectors
  May 08 10:55:34 X230 kernel: qnx4: no qnx4 filesystem (no root dir).
  May 08 10:55:34 X230 kernel: ufs: You didn't specify the type of your ufs filesystem

                               mount -t ufs -o
  ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-
  cd|openstep ...

                               >>>WARNING<<< Wrong ufstype may corrupt your filesystem, default is ufstype=old
  May 08 10:55:34 X230 kernel: ufs: ufs_fill_super(): bad magic number
  May 08 10:55:52 X230 kernel: EXT4-fs (sdb1): VFS: Can't find ext4 filesystem
  May 08 10:55:52 X230 kernel: EXT4-fs (sdb1): VFS: Can't find ext4 filesystem
  May 08 10:55:52 X230 kernel: EXT4-fs (sdb1): VFS: Can't find ext4 filesystem
  May 08 10:55:52 X230 kernel: FAT-fs (sdb1): invalid media value (0x7d)
  May 08 10:55:52 X230 kernel: squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on sdb1
  May 08 10:55:52 X230 kernel: FAT-fs (sdb1): invalid media value (0x7d)
  May 08 10:55:52 X230 kernel: qnx4: no qnx4 filesystem (no root dir).
  May 08 10:55:52 X230 kernel: ufs: You didn't specify the type of your ufs filesystem

                               mount -t ufs -o
  ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-
  cd|openstep ...

                               >>>WARNING<<< Wrong ufstype may corrupt your filesystem, default is ufstype=old
  May 08 10:55:52 X230 kernel: ufs: ufs_fill_super(): bad magic number
  May 08 10:55:52 X230 kernel: EXT4-fs (sdb4): VFS: Can't find ext4 filesystem
  May 08 10:55:52 X230 kernel: EXT4-fs (sdb4): VFS: Can't find ext4 filesystem
  May 08 10:55:52 X230 kernel: EXT4-fs (sdb4): VFS: Can't find ext4 filesystem
  May 08 10:55:52 X230 kernel: FAT-fs (sdb4): bogus number of reserved sectors
  May 08 10:55:52 X230 kernel: squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on sdb4
  May 08 10:55:52 X230 kernel: FAT-fs (sdb4): bogus number of reserved sectors
  May 08 10:55:52 X230 kernel: qnx4: no qnx4 filesystem (no root dir).
  May 08 10:55:52 X230 kernel: ufs: You didn't specify the type of your ufs filesystem

                               mount -t ufs -o
  ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-
  cd|openstep ...

                               >>>WARNING<<< Wrong ufstype may corrupt your filesystem, default is ufstype=old
  May 08 10:55:52 X230 kernel: ufs: ufs_fill_super(): bad magic number
  May 08 10:55:59 X230 kernel: EXT4-fs (sdb1): VFS: Can't find ext4 filesystem
  May 08 10:55:59 X230 kernel: EXT4-fs (sdb1): VFS: Can't find ext4 filesystem
  May 08 10:55:59 X230 kernel: EXT4-fs (sdb1): VFS: Can't find ext4 filesystem
  May 08 10:55:59 X230 kernel: FAT-fs (sdb1): invalid media value (0x7d)
  May 08 10:55:59 X230 kernel: squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on sdb1
  May 08 10:55:59 X230 kernel: FAT-fs (sdb1): invalid media value (0x7d)
  May 08 10:55:59 X230 kernel: qnx4: no qnx4 filesystem (no root dir).
  May 08 10:55:59 X230 kernel: ufs: You didn't specify the type of your ufs filesystem

                               mount -t ufs -o
  ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-
  cd|openstep ...

                               >>>WARNING<<< Wrong ufstype may corrupt your filesystem, default is ufstype=old
  May 08 10:55:59 X230 kernel: ufs: ufs_fill_super(): bad magic number
  May 08 10:55:59 X230 kernel: EXT4-fs (sdb4): VFS: Can't find ext4 filesystem
  May 08 10:55:59 X230 kernel: EXT4-fs (sdb4): VFS: Can't find ext4 filesystem
  May 08 10:55:59 X230 kernel: EXT4-fs (sdb4): VFS: Can't find ext4 filesystem
  May 08 10:55:59 X230 kernel: FAT-fs (sdb4): bogus number of reserved sectors
  May 08 10:55:59 X230 kernel: squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on sdb4
  May 08 10:55:59 X230 kernel: FAT-fs (sdb4): bogus number of reserved sectors
  May 08 10:55:59 X230 kernel: qnx4: no qnx4 filesystem (no root dir).
  May 08 10:55:59 X230 kernel: ufs: You didn't specify the type of your ufs filesystem

                               mount -t ufs -o
  ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-
  cd|openstep ...

                               >>>WARNING<<< Wrong ufstype may corrupt your filesystem, default is ufstype=old
  May 08 10:55:59 X230 kernel: ufs: ufs_fill_super(): bad magic number
  May 08 21:16:00 X230 kernel: ACPI: \_SB_.PCI0.LPC_.EC__.BAT1: Unable to dock!

  ProblemType: Bug
  DistroRelease: Ubuntu 16.04
  Package: os-prober 1.70ubuntu3
  ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6
  Uname: Linux 4.4.0-21-generic x86_64
  ApportVersion: 2.20.1-0ubuntu2
  Architecture: amd64
  CurrentDesktop: Unity
  Date: Mon May  9 11:42:57 2016
  Dependencies:
   gcc-6-base 6.0.1-0ubuntu1
   libc6 2.23-0ubuntu3
   libgcc1 1:6.0.1-0ubuntu1
  InstallationDate: Installed on 2016-05-03 (5 days ago)
  InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
  SourcePackage: os-prober
  UpgradeStatus: No upgrade log present (probably fresh install)

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