← Back to team overview

kernel-packages team mailing list archive

[Bug 1246664] Re: "Buffer I/O error on device zram0, logical block 515067"


To damian-sawiicki: Do you see a zram-config.conf file under /etc/init ?
Another stupid question: did you precisely invoke "dpkg --purge zram-
config" ?

(When I realized I still had zram-config at work after uninstalling it,
I didn't think about "dpkg --purge" and just removed whatever "zram"
files I found in the system, especially /dev/zram0 and /dev/zram1 as the
machine has two cores, and eventually zram-config.conf if it was still
there, but I am not even sure it was still there).

To Luis Henriques: I installed the generic i386 kernel and headers in a
P4, and it has also been installed to a T60 where it was running with
many programs at same time and zram-config installed and at work. All
this lasted about 45 minutes and the session didn't fail, although some
swapping was occurring. No buffer I/O occurred.

Now I am being testing in the P4, zram-config reinstalled, your kernel
i386 generic installed, since about 15 minutes. Are running: Libreoffice
writer, Firefox, Software Center, PPA Software Center…

$ uname -a
Linux peluche 3.2.0-56-generic #86~lp1246664 SMP Mon Nov 4 11:21:05 UTC 2013 i686 i686 i386 GNU/Linux

$ cat /proc/swaps 
Filename				Type		Size	Used	Priority
/dev/zram0                              partition	772040	0	5
/dev/zram1                              partition	772040	0	5
/dev/sdb5                               partition	3174396	0	-1

Before meeting with the buffer I/O error I used to change the default
values for the size of the swap devices (lower the size to 1/4) and
setup the swappiness to 0, but for the test I do leave the default
values unchanged.

I will come back later to add information according to the results I
will get. Now I will start an additional heavy load by starting Ubuntu
Builder and build a custom ISO with your newer kernel and reinstall
zram-config to it. (At least to test the behavior while 'heavy duty' is
being done).

You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.

  "Buffer I/O error on device zram0, logical block 515067"

Status in “linux” package in Ubuntu:
  Fix Released
Status in “linux” source package in Precise:
  Fix Committed
Status in “linux” source package in Saucy:
  Fix Released

Bug description:
  SRU Justification:

  Commit 12a7ad3 "zram: avoid access beyond the zram device" introduced
  a regression where valid_io_request() checks if request end coincides
  with disksize (end equals bound).  It fails if we attempt to read
  beyond the bound.


  Several errors will be logged if, for example, zram-config is

  [ 14.666280] zram: module is from the staging directory, the quality is unknown, you have been warned.
  [ 14.667040] zram: Creating 1 devices ...
  [ 14.830355] Buffer I/O error on device zram0, logical block 62411
  [ 14.830375] Buffer I/O error on device zram0, logical block 62411
  [ 14.830598] Buffer I/O error on device zram0, logical block 62411
  [ 14.830621] Buffer I/O error on device zram0, logical block 62411
  [ 14.878597] Adding 249644k swap on /dev/zram0. Priority:5 extents:1 across:249644k SS


  Commit 75c7caf5a052ffd8db3312fa7864ee2d142890c4 "zram: allow request
  end to coincide with disksize" fixes the issue by correcting the test
  in valid_io_request() function.


  I was able to reproduce the issue by simply installing zram-config in
  a precise box.


  This is a duplicate of #1217189, but for some reason neither @oibaf
  nor me can reopen it. It is in "fix released" state, but the problem
  is at most partially solved. It seems that the bug no longer causes
  lockups (described in another bug: #1215513), but is still present (as
  I get error messages on boot screen and after $ dmesg | grep zram).

  If someone has enough privileges to reopen 1217189 for "linux
  (ubuntu)" (I don't know about raring, but no one complains, so it is
  probably ok), and remove this bug (maybe merging this message to the
  comments in 1217189), I would be really grateful.

  Ubuntu 12.04.3 LTS
  Kernel Linux 3.2.0-56-generic-pae (the problem was first observed in 53 and since 54 there are no lockups).
  AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
   **** List of PLAYBACK Hardware Devices ****
   card 0: Intel [HDA Intel], device 0: ALC268 Analog [ALC268 Analog]
     Subdevices: 1/1
     Subdevice #0: subdevice #0
  ApportVersion: 2.0.1-0ubuntu17.6
  Architecture: i386
   **** List of CAPTURE Hardware Devices ****
   card 0: Intel [HDA Intel], device 0: ALC268 Analog [ALC268 Analog]
     Subdevices: 1/1
     Subdevice #0: subdevice #0
   /dev/snd/controlC0:  damian     2771 F.... pulseaudio
   Card hw:0 'Intel'/'HDA Intel at 0xf8300000 irq 47'
     Mixer name	: 'Realtek ALC268'
     Components	: 'HDA:10ec0268,10280275,00100003'
     Controls      : 16
     Simple ctrls  : 9
  DistroRelease: Ubuntu 12.04
  MachineType: Dell Inc. Vostro1710
  MarkForUpload: True
  NonfreeKernelModules: nvidia wl
  Package: linux (not installed)

  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-56-generic-pae root=UUID=bfe81069-1c35-4ccc-a23a-33528ac81877 ro selinux=1 security=selinux quiet splash
  ProcVersionSignature: Ubuntu 3.2.0-56.86-generic-pae 3.2.51
   linux-restricted-modules-3.2.0-56-generic-pae N/A
   linux-backports-modules-3.2.0-56-generic-pae  N/A
   linux-firmware                                1.79.7
  StagingDrivers: zram
  Tags:  precise running-unity staging
  Uname: Linux 3.2.0-56-generic-pae i686
  UpgradeStatus: No upgrade log present (probably fresh install)
  UserGroups: adm cdrom dip lpadmin netdev plugdev sambashare sudo
  dmi.bios.date: 09/09/2008
  dmi.bios.vendor: Dell Inc.
  dmi.bios.version: A09
  dmi.board.name: 0X805C
  dmi.board.vendor: Dell Inc.
  dmi.chassis.type: 8
  dmi.chassis.vendor: Dell Inc.
  dmi.chassis.version: N/A
  dmi.modalias: dmi:bvnDellInc.:bvrA09:bd09/09/2008:svnDellInc.:pnVostro1710:pvrNull:rvnDellInc.:rn0X805C:rvr:cvnDellInc.:ct8:cvrN/A:
  dmi.product.name: Vostro1710
  dmi.product.version: Null
  dmi.sys.vendor: Dell Inc.

To manage notifications about this bug go to: