[$] Retrieving mount and filesystem information in user space

In something of a follow-on from the mount-operation monitoring session the
previous day, Christian Brauner led another discussion about providing user
space with a mechanism to get current mount information on day two of the
2023 Linux Storage, Filesystem,
Memory-Management and BPF Summit. The session also continued on from
one at last year's
summit—and likely others before that.
There are two separate proposals for ways to retrieve this kind of
information, one from Miklos Szeredi and another from David Howells, both
of whom were present this year; Brauner's intent was to try to reach some
kind of agreement on the way forward in the session.