zfs-dkms: support Linux 6.5

[Andrea Righi]

[Impact]

zfs-dkms fails to build with the latest 6.5 kernel in Mantic:

configure: error:
 *** None of the expected "bops->release()" interfaces were detected.
 *** This may be because your kernel version is newer than what is
 *** supported, or you are using a patched custom kernel with
 *** incompatible modifications.
 ***
 *** ZFS Version: zfs-2.2.0~rc1-0ubuntu2
 *** Compatible Kernels: 3.10 - 6.3

[Test case]

 $ sudo apt install zfs-dkms

[Fix]

Upstream zfs can now be compiled with kernel 6.5, cherry pick the minimum subset of patches to support the new kernel ABI.

[Regression potential]

We may experience filesystem regressions or potentially kernel crashes with kernels >= 6.5.

ProblemType: Bug
DistroRelease: Ubuntu 23.10
Package: zfs-dkms 2.2.0~rc1-0ubuntu2
ProcVersionSignature: User Name 6.5.0-4.4-generic 6.5.0-rc6
Uname: Linux 6.5.0-4-generic x86_64
ApportVersion: 2.27.0-0ubuntu2
Architecture: amd64
CasperMD5CheckResult: unknown
CloudArchitecture: x86_64
CloudBuildName: server
CloudID: nocloud
CloudName: unknown
CloudPlatform: nocloud
CloudSerial: 20230801
CloudSubPlatform: config-disk (/dev/vdb)
Date: Wed Aug 16 07:45:37 2023
PackageArchitecture: all
ProcEnviron:
 LANG=C.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/bash
 TERM=xterm-256color
 XDG_RUNTIME_DIR=<set>
SourcePackage: zfs-linux
UpgradeStatus: No upgrade log present (probably fresh install)

[Andrea Righi (arighi)]

debdiff in attach allows to build zfs-dkms with Linux 6.5.

[Andrea Righi (arighi)]

With the attached debdiff I can build the module, but when it's build using dkms zfs.ko is failing to load with the following error:

$ sudo modprobe zfs
modprobe: ERROR: could not insert 'zfs': Cannot allocate memory

I suspect dkms is doing something odd when building the module, because the same exact code built doing a plain ./configure and make can be loaded correctly.

[Paul (pgjensen)]

This doesn't affect me on mantic with the latest packages/kernel from mantic updates ppa.