leverage pseudofs for autofs?

[Alfred Perlstein]

fs & DES,

I'm looking at reimplementing autofs.

I've had my eye on psuedofs as a base for autofs since it seems
like I can override most of the methods.

At a glance what has me wondering is that there seems to be some
code in the pseudofs base that checks for processes and traverses
allproc.  For instance "pfs_readdir()" implies some sort of tie
between the number of dir entries and the reading of the directory,
obviously for autofs this would be different.

I do not need this in autofs and can probably get around this by
overloading those vnops entries in my filesystem switch.

The basic requirements of autofs are:

1) In-memory filesystem.
2) if a lookup is done for a non-existant dir
   entry then block the process.  (unless it's
   "special" ie. the actual automounter).
3) for readdir, do some magic to send requests
   back to userspace to "fill in" a dynamic listing.
   basically, vop_readdir will optionally dispatch
   back to userland for this.

I'd like to reduce code duplication.  Pseudofs looks
like a great starting point. 

Am I missing some tightly coupled issue that makes this a non-starter?

Would you be open to adding hooks if autofs needs them?

Should I be looking elsewhere or just starting from scratch?

thank you!
-- 
- Alfred Perlstein
.- AMA, VMOA #5191, 03 vmax, 92 gs500, 85 ch250, 07 zx10
.- FreeBSD committer