System hangs up or make filesystem read-only

[Yves Maurischat]

With kernel 4.15.0-151 the system very often (up to several times an hour) hangs up completely and doesn't react to input of any kind. It then has to be restarted the hard way (i.e. by prssing the power button for several seconds).

At other times a message is displayed, saying that the file system is read-only, nothing can be saved to the hard disk anymore (i.e. no files written by applications like QtCreator).

These problems haven't been observed after booting kernel 4.15.0-147.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-151-generic 4.15.0-151.157
ProcVersionSignature: Ubuntu 4.15.0-151.157-generic 4.15.18
Uname: Linux 4.15.0-151-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.24
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: ymau 3910 F.... pulseaudio
 /dev/snd/controlC1: ymau 3910 F.... pulseaudio
 /dev/snd/controlC3: ymau 3910 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Tue Jul 27 07:57:48 2021
MachineType: LENOVO 20AN00E3GE
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-151-generic root=UUID=61548d74-4a1e-4042-a755-9d9879c39a93 ro splash quiet vt.handoff=1
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-151-generic N/A
 linux-backports-modules-4.15.0-151-generic N/A
 linux-firmware 1.173.20
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/20/2020
dmi.bios.vendor: LENOVO
dmi.bios.version: GLETA1WW (2.55 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20AN00E3GE
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40705 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrGLETA1WW(2.55):bd04/20/2020:svnLENOVO:pn20AN00E3GE:pvrThinkPadT440p:rvnLENOVO:rn20AN00E3GE:rvrSDK0J40705WIN:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.family: ThinkPad T440p
dmi.product.name: 20AN00E3GE
dmi.product.version: ThinkPad T440p
dmi.sys.vendor: LENOVO

[Chris Guiver (guiverc)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

You state "It then has to be restarted the hard way (i.e. by prssing the power button for several seconds)"

So does this mean even SysRq commands direct to the kernel don't work to allow a safe reboot, shutdown? (if you don't recall the keys, a quick search on a phone for "magic sysrq" will find https://en.wikipedia.org/wiki/Magic_SysRq_key which is pretty good to find the common REISUB statekeystrokes).

(Not being able to use SysRq to direct kernel directly shows the kernel is a very bad state. I read a RO file-system sometimes in your description, so I'd also check the health of your hardware & explore the logs and the messages before your "the file system is read-only" mentioned issue.)

You can also find help with your problem in the support forum of your local Ubuntu community http://loco.ubuntu.com/ or asking at https://askubuntu.com or https://ubuntuforums.org, or for more support options please look at https://discourse.ubuntu.com/t/community-support/709

[Yves Maurischat (aetherrauschen)]

I didn't try the SysRq commands, as I didn't know about them. My impression was, that everything just stopped working, nothing except the hard reset seemed to cause any reaction, hardware or otherwise.

The syslog didn't show anything unusual either. I compared several versions of the syslog after different freezes and didn't find any similarities in the last 5 minutes before it stopped working.

A co-worker using Ubuntu 18.04. and kernel 4.15.0-151 also reported problems with freezes, that didn't occur in 4.15.0-147, but he didnt have the RO filesystem problem.

I will check whether the SysRq commands work the next freeze.

[Yves Maurischat (aetherrauschen)]

Update:
- SysRq commands keep working
- Memtest86 and Disks -> SMART Data & Self Test didn't show any problems with memory or SSD

So I assume it's a problem that originates in kernel 4.15.0-151, as 147 doesn't show any of the problems and nothing else has changed between booting 151 vs. booting 147.

[Stefan Bader (smb)]

This seems to be another Thinkpad/laptop showing issues (see bug 1938013). I would be duplicating this bug against the one which has the investigation ongoing.