Re: [PATCH 3/3] p9auth: add p9auth driver

[ron minnich <rminnich@gmail.com>]

On Fri, Apr 23, 2010 at 8:36 PM, Serge E. Hallyn <serue@us.ibm.com> wrote:

> An fs actually seems overkill for two write-only files for
> process-related information.  Would these actually be candidates
> for new /proc files?
>
>        /proc/grantcred - replaces /dev/caphash, for privileged
>                tasks to tell the kernel about new setuid
>                capabilities
>        /proc/self/usecred - replaces /dev/capuse for unprivileged
>                tasks to make use of a setuid capability

An fs is fine.

To relate this to Plan 9, where it all began, might be useful. There's
no equivalent in Plan 9 to Linux/Unix devices of the major/minor
number etc. variety. In-kernel drivers and out-of-kernel servers both
end up providing the services (i.e. file name spaces) that we see in a
Linux file system. So the Plan 9 driver for the capability device
really does match closely in function and interface to a Linux
kernel-based file system.

Hence, making devcap a file system is entirely appropriate, because it
best fits the way it works in Plan 9: a kernel driver that provides
two files.

It's pretty easy to write a Linux VFS anyway, so it makes sense from
that point of view.

Eric, that was a great suggestion.

ron