RFC: erofs-utils:mkfs: add unprivileged container use-case support

[Gao Xiang]

Hi Naoto,

On Wed, Aug 10, 2022 at 02:59:42AM +0900, Naoto Yamaguchi wrote:
> Hi all.
> 
> I investigate each read only filesystem for linux at linux container
> use-case.  The erofs is most interesting filesystem.

First of all, many thanks for your interest! Yes, now EROFS is actively
developing for container use cases as well, and we're happy to
accept/maintain any useful features about this area!

> A each files of guest root filesystem need to shift uid/gid in case of
> unprivileged container to use uid/gid namespace.  I work adding
> uid/gid offsetting support to erofs-utils mkfs tool now.
> Will be this patch accept in upstream community?

Could you give more details about this? EROFS already supports idmapped
mount for container use cases since 5.19, so I guess uid/gid offsets
can be set by this?

I'm still somewhat new to container world, it would be helpful to drop
more hints of this ;)

Thanks,
Gao Xiang

> 
> Thanks,
> Naoto Yamaguchi,
> a member of Automotive Grade Linux Instrument Cluster EG.