Arch Linux

_Map_

Member

Registered: 2024-05-18

Posts: 2

[SOLVED] Unable to use idmapping in incus with linux 6.9

Hi,

Since I updated my kernel to 6.9.1, I can't start any incus instance that use the id mapping capability of the kernel, I have this message :

Error: Failed to setup device mount "docker": idmapping abilities are required but aren't supported on system

Where "docker" is a disk mount defined like this :

devices:
  docker:
    path: /docker
    type: disk
    source: /dev/mapper/mydisk
    raw.mount.options: rw,relatime,ssd,space_cache=v2,subvolid=258,subvol=/docker
    shift: true

I already confirmed that downgrading the kernel to  6.8.9 does fix the issue, but now after some search in the kernel release note and in a bunch of documentation I'm a bit lost as how I can investigate more/ fix the issue.
The only diff that I could find in the system journal is this line :

LSM: initializing lsm=capability,landlock,lockdown,yama,bpf

Which in 6.8.9 has one other entry :

LSM: initializing lsm=capability,landlock,lockdown,yama,bpf,integrity

Any help / troubleshooting step is welcome.

Last edited by _Map_ (2024-05-20 08:43:18)

loqs

Member

Registered: 2014-03-06

Posts: 18,815

Re: [SOLVED] Unable to use idmapping in incus with linux 6.9

Have you considered bisecting the linux kernel between 6.8 and 6.9? You can find 6.9 in the ALA to verify the issue is between 6.8 and 6.9 not 6.9 and 6.9.1.  The only possibly related commit I spotted was https://github.com/torvalds/linux/commi … fc16e6ebd5.

_Map_

Member

Registered: 2024-05-18

Posts: 2

Re: [SOLVED] Unable to use idmapping in incus with linux 6.9

I didn't know there was a tool directly in git for that thank you, and you're right it's this commit that introduced the regression.

I'll report it in the proper channels, thank you.