Re: [PATCH v2] initramfs: Support unpacking directly to tmpfs

Hi, Rob and Emily. All problems mentioned in this thread are solved!!!
Let me explain.

Rob Landley <[email protected]>:
> Your mount tree in a container does NOT start empty.

We got [1], which allows us to create new empty mount namespace.

Well, not quite empty. Assuming that we also have [2] and we passed
"nullfs_rootfs" in kernel command line, then open_tree(OPEN_TREE_NAMESPACE)
will create new mount
namespace, which will contain (in usual case) exactly two mounts: nullfs
and whatever we passed to open_tree call.

I. e. [1] solves "create new empty mount namespace" problem.

And [2] introduces nullfs you mentioned.

These patches are already in next, but not yet in mainline. So you have
some time to try to raise some concerns. If you have some concerns,
raise them in [1] and [2].

> despite the openat() family being in posix-2008 we sadly don't appear to have a
> mountat()...". I dunno. That's design work to properly fix the issue.

We do have mountat. It is called fsopen+fsconfig+fsmount+move_mount.
By the way, we very recently got them documented:
https://manpages.debian.org/unstable/manpages-dev/fsopen.2.en.html .


[1] https://lore.kernel.org/all/[email protected]/
[2] https://lore.kernel.org/all/[email protected]/

-- 
Askar Safin