kernel panic attempting to unmount device with errors

[James Hunt]

/var/log/kern.log shows:

Aug 28 17:32:20 faire kernel: [37077.847109] EXT4-fs (sde1): warning: maximal mount count reached, running e2fsck is recommended
Aug 28 17:32:20 faire kernel: [37077.848127] EXT4-fs (sde1): recovery complete
Aug 28 17:32:20 faire kernel: [37077.848915] EXT4-fs (sde1): mounted filesystem with ordered data mode. Opts: (null)
Aug 28 17:37:17 faire kernel: [37374.626258] EXT4-fs (sdd1): error count since last fsck: 8
Aug 28 17:37:17 faire kernel: [37374.626262] EXT4-fs (sdd1): initial error at time 1389635241: ext4_mb_generate_buddy:756
Aug 28 17:37:17 faire kernel: [37374.626264] EXT4-fs (sdd1): last error at time 1391881607: ext4_mb_generate_buddy:756
Aug 28 19:03:10 faire kernel: [ 0.000000] Initializing cgroup subsys cpuset
Aug 28 19:03:10 faire kernel: [ 0.000000] Initializing cgroup subsys cpu
Aug 28 19:03:10 faire kernel: [ 0.000000] Initializing cgroup subsys cpuacct
Aug 28 19:03:10 faire kernel: [ 0.000000] Linux version 3.16.0-10-generic (buildd@aatxe) (gcc version 4.9.1 (Ubuntu/Linaro 4.9.1-8ubuntu1) ) #15-Ubuntu SMP Thu Aug 21 16:26:44 UTC 2014 (Ubuntu 3.16.0-10.15-generic 3.16.1)
Aug 28 19:03:10 faire kernel: [ 0.000000] Command line: BOOT_IMAGE=/vmlinuz-3.16.0-10-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=7
Aug 28 19:03:10 faire kernel: [ 0.000000] KERNEL supported cpus:

It seems that I have a USB stick which has errors. When I attempted to unmount it, my system froze and had to be alt-sysreq s-u-b'd.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: linux-image-generic 3.16.0.10.11
ProcVersionSignature: Ubuntu 3.16.0-10.15-generic 3.16.1
Uname: Linux 3.16.0-10-generic x86_64
ApportVersion: 2.14.6-0ubuntu2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: james 3770 F.... pulseaudio
 /dev/snd/controlC0: james 3770 F.... pulseaudio
CurrentDesktop: Unity
Date: Thu Aug 28 19:07:46 2014
HibernationDevice: RESUME=UUID=db600bbe-faca-41f4-9338-c3e8e227599a
InstallationDate: Installed on 2014-04-11 (138 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Daily amd64 (20140409)
MachineType: LENOVO 20AQCTO1WW
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.16.0-10-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.16.0-10-generic N/A
 linux-backports-modules-3.16.0-10-generic N/A
 linux-firmware 1.132
SourcePackage: linux
UpgradeStatus: Upgraded to utopic on 2014-05-08 (112 days ago)
dmi.bios.date: 02/10/2014
dmi.bios.vendor: LENOVO
dmi.bios.version: GJET71WW (2.21 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20AQCTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: 0B98405 STD
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrGJET71WW(2.21):bd02/10/2014:svnLENOVO:pn20AQCTO1WW:pvrThinkPadT440s:rvnLENOVO:rn20AQCTO1WW:rvr0B98405STD:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 20AQCTO1WW
dmi.product.version: ThinkPad T440s
dmi.sys.vendor: LENOVO

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Can you reproduce the panic? If so, can you see if it also happens with prior kernels and if it's new in 3.16?

Also, it might be a good test to see if this happens with the latest mainline kernel:
http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.17-rc2-utopic/

[Brad Figg (brad-figg)]

This change was made by a bot.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]