Linux 6.10 compatibility on s390x

[Harry-Chen]

This issue tracks the compatibility with Linux 6.10 on IBM s390x arch. The main problem originates from the GPL only symbol vm_layout added in Linux 6.10-rc 1 2 (and some following commits), which would cause the following error:

  CC [M]  /home/ubuntu/zfs/module/os/linux/zfs/zvol_os.o
  LD [M]  /home/ubuntu/zfs/module/zfs.o
  MODPOST /home/ubuntu/zfs/module/Module.symvers
ERROR: modpost: GPL-incompatible module zfs.ko uses GPL-only symbol 'vm_layout'
make[5]: *** [scripts/Makefile.modpost:145: /home/ubuntu/zfs/module/Module.symvers] Error 1
make[4]: *** [/usr/src/linux-headers-6.10.0-13-generic/Makefile:1891: modpost] Error 2

The original comment is made by @piso77 in https://github.com/openzfs/zfs/pull/16250#issuecomment-2202351855

This problem is also reported downstream in Ubuntu: https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/2071774

TL;DR: kernel s390 arch maintainer Vasily Gorbik has proposed a patch to change vm_layout to non-GPL-only. It will land in Linux 6.11 and (hopefully) 6.10 stable.

[tonyhutter]

@Harry-Chen thank you for the info! Looks like s390 ZFS users may want to skip the 6.10 kernel until the fix lands.

[tjaalton]

this is in 6.10.3

[Harry-Chen]

@piso77 Would you have another try on 6.10.3?

[tjaalton]

builds fine with 6.11rc at least https://autopkgtest.ubuntu.com/packages/z/zfs-linux/oracular/s390x