ACK: [SRU][Noble/mantic/jammy][PATCH 0/1] Include erofs in linux-modules instead of linux-modules-extra

[Daan De Meyer]

Hi Roxana,

I was wondering if this patch will be applied to linux-azure as well.
If not, how can I propose this change to be applied to linux-azure as
well?

The use case is running systemd-nspawn containers with erofs
filesystems on Github Actions in systemd's CI.

Cheers,

Daan

On Wed, 28 Feb 2024 at 11:01, Roxana Nicolescu
<roxana.nicolescu at canonical.com> wrote:
>
>
> On 23/02/2024 14:25, Daan De Meyer wrote:
> > Buglink: https://bugs.launchpad.net/bugs/2054809
> >
> > SRU Justification:
> >
> > [Impact]
> >
> > The erofs.ko module (CONFIG_EROFS) is currently shipped in linux-modules-extra. This makes it
> > hard to pull in via the linux-virtual package, it can only come from the linux-generic one that
> > also pulls in the firmware and everything else needed for baremetal, and that serves no purpose
> > in a qemu VM. This stops VMs using these kernels from using the erofs filesystem. Erofs is a modern
> > alternative to squashfs that supports more features such as ACLs. The following LPC presentation
> > has more details on erofs and its advantages over squashfs: https://youtu.be/jt-hp_LtSBc.
> >
> > A user launching a VM using the linux-virtual kernel image is not able to mount erofs filesystems due
> > to the lack of this kconfig. We make extensive use of erofs in systemd's upstream CI, which is running
> > on Github Actions.
> >
> > [Fix]
> >
> > Please consider moving this module to linux-modules.
> >
> > These are already enabled in the 'main' kernel config, and in other distros. In Debian/Archlinux/Fedora
> > it is a (core) module that is built by default.
> >
> > To verify this works, it is sufficient to create an erofs filesystem with mkfs.erofs and verify that it
> > can be mounted:
> >
> > $ mkdir sources
> > $ echo abcde > sources/file
> > $ mkfs.erofs erofs sources
> > $ mount erofs mnt --mkdir
> > $ ls mnt
> > file
> >
> > Without this module installed and loaded, the mount will fail. Once enabled, it will succeed.
> >
> > [Test Plan]
> >
> > 1. pull built linux-modules packages for architectures with do_extras_package
> >     set to true;
> > 2. extract the deb and check if erofs kernel module file exists:
> >
> >     $ dpkg-deb -R linux-modules-*.deb .
> >     $ find . -name erofs.ko\*
> >
> > [Regression Potential]
> >
> > Moving a module from a less-common to a more-common package should not have any negative side effects.
> > The main effect will be a little more disk space used by the more common package, whether the module
> > is in use or not. There will also be more functionality available in the default installation, which
> > means a slightly increased surface and possibility of new bugs in case it gets used.
> >
> > Daan De Meyer (1):
> >    Include erofs in linux-modules instead of linux-modules-extra
> >
> >   debian.master/control.d/generic.inclusion-list | 1 +
> >   1 file changed, 1 insertion(+)
> >
> Will include this to mantic and jammy.
>
> Acked-by: Roxana Nicolescu <roxana.nicolescu at canonical.com>