Re: [PATCH v4 2/2] ovl: introduce new "uuid=off" option for inodes index feature

From: Miklos Szeredi
Date: Tue Oct 06 2020 - 11:13:41 EST


On Fri, Sep 25, 2020 at 10:35 AM Pavel Tikhomirov
<ptikhomirov@xxxxxxxxxxxxx> wrote:

> Note: In our (Virtuozzo) use case users inside a container can create
> "regular" overlayfs mounts without any "index=" option, but we still
> want to migrate this containers with CRIU so we set "index=on" as kernel
> default so that all the container overlayfs mounts get support of file
> handles automatically. With "uuid=off" we want the same thing (to be
> able to "copy" container with uuid change) - we would set kernel default
> so that all the container overlayfs mounts get "uuid=off" automatically.

I'm not sure I buy that argument for a kernel option. It should
rather be a "container" option in that case, but AFAIK the kernel
doesn't have a concept of a container. I think this needs to be
discussed on the relevant mailing lists.

As of now mainline kernel doesn't support unprivileged overlay mounts,
so I guess this is not an issue. Let's just merge this without the
kernel and the module options.

Thanks,
Miklos