kernel-packages team mailing list archive

[Joseph Salisbury <joseph.salisbury@xxxxxxxxxxxxx>]

Given the number of bugs that the Kernel Team receives during any
development cycle it is impossible for us to review them all. Therefore,
we occasionally resort to using automated bots to request further
testing. This is such a request.

We are approaching release and would like to confirm if this bug is
still present. Please test again with the latest development kernel and
indicate in the bug if this issue still exists or not.

You can update to the latest development kernel by simply running the
following commands in a terminal window:

    sudo apt-get update
    sudo apt-get dist-upgrade

If the bug still exists, change the bug status from Incomplete to
Confirmed. If the bug no longer exists, change the bug status from
Incomplete to Fix Released.

Thank you for your help, we really do appreciate it.


** Changed in: linux (Ubuntu)
       Status: Confirmed => Incomplete

** Tags added: kernel-request-3.11.0-7.14

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1202994

Title:
  EXT4 filesystem corruption with uninit_bg and error=continue

Status in “linux” package in Ubuntu:
  Incomplete

Bug description:
  There was a long and complicated sequence of activities involving
  mdadm, lvm, and specifically pvmove leading up to the point where the
  corruption was discovered, but I suspect most were irrelevant. AFAICT,
  the bug was triggered by the following simple operations:

  * the FS was unmounted & remounted -- thus, the journal was fresh and hadn't wrapped (which other reports appear to indicate would have prevented the bug showing up)
  * the FS options include uninit_bg AND error=continue
  * a bunch of files were then copied onto the FS -- this was the last write operation on the FS.

  Later, e2fsck indicated a bunch of problems, including corrupted group
  descriptors. Specifically, it fould that many blocks were now claimed
  by two files; in each case, one was an old file and one was one of
  those newly copied, and the contents matched the expected data for
  latter.

  So I think this starts with an instance of the miscalculation of
  checksums in uninit_bg blocks (fixed by Ted Ts'o last June), followed
  by the (invalid or uninitialised) bitmap being used anyway (because
  error=continue) and the blocks it appeared to show as free then being
  allocated to new files.

  Jul 15 18:01:03 redshift kernel: [ 9332.021245] EXT4-fs error (device dm-1): ext4_mb_generate_buddy:739: group 2968, 8105 clusters in bitmap, 0 in gd
  ...
  Jul 16 18:05:14 redshift kernel: [95982.560034] EXT4-fs (dm-1): error count: 1
  Jul 16 18:05:14 redshift kernel: [95982.560044] EXT4-fs (dm-1): initial error at 1373907663: ext4_mb_generate_buddy:739
  Jul 16 18:05:14 redshift kernel: [95982.560053] EXT4-fs (dm-1): last error at 1373907663: ext4_mb_generate_buddy:739
  ...
  Jul 16 20:53:19 redshift kernel: [106068.077526] EXT4-fs (dm-1): ext4_check_descriptors: Checksum for group 0 failed (47831!=4825)
  Jul 16 20:53:19 redshift kernel: [106068.077540] EXT4-fs (dm-1): ext4_check_descriptors: Checksum for group 1 failed (14670!=8882)

  I see that in an astonishing display of synchronicity, Darrick J Wong
  filed a patch at 17 Jul 2013 04:02  -- the very next day, or maybe
  even the same day, depending on timezone -- to prevent the knockon
  effects (see "[PATCH] ext4: Prevent massive fs corruption if verifying
  the block bitmap fails" at http://permalink.gmane.org/gmane.comp.file-
  systems.ext4/39535 ).

  But what puzzles me is that the initial triggering bug is still in
  this kernel (vmlinuz-3.2.0-49-generic), when according to this
  conversation https://bugzilla.kernel.org/show_bug.cgi?id=42723#c8 the
  fix was backported to 3.2.20? Is it possible that there is another way
  of getting the "ext4_mb_generate_buddy:739" error?

  I have kept an e2image dump of the corrupted FS in case it's of any
  use to EXT4 developers, but it's not attached, as even in QCOW2 format
  it's ~1Gb.

  ProblemType: Bug
  DistroRelease: Ubuntu 12.04
  Package: linux-image-3.2.0-49-generic 3.2.0-49.75
  ProcVersionSignature: Ubuntu 3.2.0-49.75-generic 3.2.46
  Uname: Linux 3.2.0-49-generic x86_64
  AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
  ApportVersion: 2.0.1-0ubuntu17.3
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC1:  dsg        7005 F.... pulseaudio
   /dev/snd/controlC0:  dsg        7005 F.... pulseaudio
  CRDA:
   country AW:
   	(2402 - 2482 @ 40), (N/A, 20)
   	(5170 - 5250 @ 40), (N/A, 20)
   	(5250 - 5330 @ 40), (N/A, 20), DFS
   	(5490 - 5710 @ 40), (N/A, 27), DFS
  Card0.Amixer.info:
   Card hw:0 'SB'/'HDA ATI SB at 0xfe024000 irq 16'
     Mixer name	: 'Realtek ALC892'
     Components	: 'HDA:10ec0892,1458a102,00100302'
     Controls      : 46
     Simple ctrls  : 21
  Card1.Amixer.info:
   Card hw:1 'HDMI'/'HDA ATI HDMI at 0xfdefc000 irq 19'
     Mixer name	: 'ATI RS690/780 HDMI'
     Components	: 'HDA:1002791a,00791a00,00100000'
     Controls      : 4
     Simple ctrls  : 1
  Card1.Amixer.values:
   Simple mixer control 'IEC958',0
     Capabilities: pswitch pswitch-joined penum
     Playback channels: Mono
     Mono: Playback [on]
  Date: Thu Jul 18 19:04:57 2013
  HibernationDevice: RESUME=UUID=2ab26064-3b90-475d-b3c2-51a70c2d990a
  InstallationMedia: Kubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120822.2)
  MachineType: Gigabyte Technology Co., Ltd. GA-890GPA-UD3H
  MarkForUpload: True
  ProcEnviron:
   LANGUAGE=en_GB
   TERM=xterm
   PATH=(custom, no user)
   LANG=en_GB.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 radeondrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.2.0-49-generic root=/dev/mapper/system-kubuntu ro quiet splash vt.handoff=7
  RelatedPackageVersions:
   linux-restricted-modules-3.2.0-49-generic N/A
   linux-backports-modules-3.2.0-49-generic  N/A
   linux-firmware                            1.79.4
  RfKill:
   0: phy0: Wireless LAN
   	Soft blocked: yes
   	Hard blocked: no
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 07/23/2010
  dmi.bios.vendor: Award Software International, Inc.
  dmi.bios.version: FD
  dmi.board.name: GA-890GPA-UD3H
  dmi.board.vendor: Gigabyte Technology Co., Ltd.
  dmi.board.version: x.x
  dmi.chassis.type: 3
  dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
  dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrFD:bd07/23/2010:svnGigabyteTechnologyCo.,Ltd.:pnGA-890GPA-UD3H:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnGA-890GPA-UD3H:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
  dmi.product.name: GA-890GPA-UD3H
  dmi.sys.vendor: Gigabyte Technology Co., Ltd.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1202994/+subscriptions