[9front] Re: Design principles for Plan 9 file systems?

[Anthony Martin <ality@pbrane.org>]

Joël Franusic <joel@franusic.com> once said:
> Ultimately, I'd like to come up with a set of guidelines or principles
> to follow when writing a file server such that a Plan 9 veteran could
> mount the provided file system and quickly understand how it works.

The 9P protocol gives you a uniform API for interacting with a
resource: open, read, write, close. How you represent a specific
resource depends on what the resource is or does. There are
some clear patterns that most file systems use to model their
resources:

- single control file

- multiple control files

- control file and data file

- filter

- multiplexer

- protocol converter

It's not a coincidence that all of them have roots in signal
processing and telecom work. Bell Labs was part of the
phone company after all.

Study Sandy Fraser's work if you seek enlightenment.

As for what goes into the control files, it's usually simple
messages akin to writing registers on a device or setting
up a call on a switch. Deviation from this is unusual.

Cheers,
  Anthony