nnpfs/xfs tutorial

[Tomas Olsson]

Kristaps Johnson <kristaps at gradient-enterprises.com> writes:
> This project, I think, is somewhat OT to arla-drinkers so I'll keep any
> additional releases local to the web site (unless requested otherwise, of
> course!).
> 
Well, arla-drinkers is the place to discuss nnpfs, so nnpfs documentation
is on-topic. And since nnpfs is meant to be generic, any other daemons that
use it are good to know about when we change things. Anything nnpfs or arla
related is welcome.

> Pending issues are (1) the pioctl interface and (2) ADVLOCK.
>
ADVLOCK isn't used, so you can probably forget about it.  It will probably
be removed unless we're told that people do want it there.

Also, passing the result of fhget to nnpfs in INSTALLDATA is optional. The
path is mandatory (in some cases fh's don't work).

> What does NNPFS mean?
>
Nothing really.  We needed a new name and went for a nice name that is
unlikely to clash with other filesystems. And it fits in our current naming
theme.

Feel free to make up a good interpretation. Some possible building blocks
are "new" "neutral" "normalized" "geNeric" "proxy" "portable" "file"
"system".

/t