One of the first changes merged for the upcoming 7.0 release was <a
href="https://lwn.net/ml/all/20260112-work-immutable-rootfs-v2-0-88dd1c34a204@kernel.org/">nullfs</a>,
an empty filesystem that cannot actually contain any files. One might
logically wonder why the kernel would need such a thing. It turns out,
though, that there are places where a null filesystem can come in handy.
For 7.0, nullfs will be used to make life a bit easier for <tt>init</tt>
programs; future releases will likely use nullfs to increase the isolation
of kernel threads from the init process.