kernel lockups unmounting ext4 lvm2 snapshots
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Linux |
Invalid
|
Unknown
|
|||
linux (Ubuntu) |
Triaged
|
High
|
Unassigned | ||
Lucid |
Triaged
|
High
|
Unassigned |
Bug Description
I have experienced IO lock-ups when unmounting lvm2 snapshots partitions containing ext4. All IO, sound, etc will hang, though alt-sysrq remains responsive (I can do alt-sysrq-b and it reboots, e.g.).
This problem is intermittent, unfortunately, but I see it most often when I have performing a package build via sbuild in an LVM based snapshot schroot.
Steps to reproduce (probably not the minimal test case...):
Terminal 1:
- create an MD device across two physical drives
- sudo -s
- vgcreate testvg /dev/md0
- lvcreate -L10G -n testlv testvg
- mkfs.ext4 /dev/testvg/testlv
- mkdir /mnt/test
- mount /dev/testvg/testlv /mnt/test
- apt-get install ubuntu-dev-tools
- while :; do cp -a /usr /mnt/test; sleep 1; rm -rf /mnt/test/usr; done
Then in Terminal 2:
- mk-sbuild --vg=VG karmic
- cd /tmp
- dget https:/
- while :; do sbuild -d karmic dpkg*.dsc"; done &
- while :; do sbuild -d karmic dpkg*.dsc"; done
ProblemType: Bug
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.21.
AplayDevices:
**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: ALC268 Analog [ALC268 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
Card hw:0 'Intel'/'HDA Intel at 0xe0420000 irq 22'
Mixer name : 'Realtek ALC268'
Components : 'HDA:10ec0268,
Controls : 17
Simple ctrls : 11
Date: Wed Mar 10 15:28:56 2010
DistroRelease: Ubuntu 10.04
HibernationDevice: RESUME=/dev/md1
Package: linux-image-
ProcCmdLine: BOOT_IMAGE=
ProcEnviron:
LANGUAGE=en_US:en
PATH=(custom, user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcVersionSign
Regression: Yes
RelatedPackageV
Reproducible: Yes
RfKill:
SourcePackage: linux
TestedUpstream: No
Uname: Linux 2.6.32-16-generic x86_64
WpaSupplicantLog:
dmi.bios.date: 09/22/2008
dmi.bios.vendor: Intel Corp.
dmi.bios.version: JOQ3510J.
dmi.board.
dmi.board.name: DQ35JO
dmi.board.vendor: Intel Corporation
dmi.board.version: AAD82085-800
dmi.chassis.type: 3
dmi.modalias: dmi:bvnIntelCor
description: | updated |
Changed in linux: | |
status: | Unknown → Invalid |
Changed in linux (Ubuntu Lucid): | |
importance: | Low → High |
Sometimes I'll survive a lock up if I just wait long enough. I see my load hit 1 solid for a long time, and I see in ps output:
$ ps auwwx | grep " D "
root 7143 0.0 0.0 0 0 ? D 15:51 0:00 [kdmflush]
root 7146 0.1 0.0 0 0 ? D 15:51 0:00 [kcopyd]
root 7239 0.0 0.0 0 0 ? D 15:51 0:00 [jbd2/dm-33-8]
root 7518 0.0 0.0 0 0 ? D 15:52 0:00 [flush-252:33]