features in samba 3.alpha (VFS)

[Michael H Buselli]

David Collier-Brown said:

> > You could go the full pam-like interface, but I don't see how it helps
> > much - the ability to be 'sufficient' implies the module signling back
> > things that never change - why not just keep them in the code?
> > (Specifing that an SQL module must pass-though its ops to another module
> > doesn't make sense, and specifing the virus scanner as the final module
> > doesn't either).
> 
> 	That was one of the ussues: ordering the VFS
> 	components in a necessary and sufficient relationship.
> 	We disn't have a way to express such constraints,
> 	so the user would "just have to know" what order
> 	to stack them in.

> 
> 	Hmmn: if we added a hook for a set of annotations,
> 	we might be able to 
> 	1) deliver a simple user-must-order version now
> 	2) experiment with different ordering constraints
> 	   for later rollout

I don't think you want to go with auto-ordering on any first release of
this stuff.  That's like trying to build the castle when you've been
asked to build a moat around a hill.  The version 2 VFS modules probably
can't do that as they are, but they are perfectly capable of being
stacked if the user knows what he's doing.

Besides, most users using VFS modules either know what they're doing or
shouldn't be using VFS modules.

> 	How about an ordered list of
> 		vfs = <binary> <constraint> [options]
> 	where 
> 		binary is a path to a .so
> 		constraints are To Be Defined, except
> 			for the null constraint, "-"
> 		options are specific to the binary

I like it, but I think using the constraint option right now is getting
too far ahead of the game.

> 	where the "optional" doesn't get evaluated by the
> 	current vfs loader, so it's really a note to the
> 	human.

I wouldn't even bother putting the constraint field in right now.  It
would just confuse people that expect it to change the behaviour of
Samba.

--
Michael H. Buselli
Senior Network Systems Specialist            Abbott Laboratories
Email: busellim at pprd.abbott.com              D472/AP9A-L20
Phone: 847-935-4624                          100 Abbott Park Road
Fax: 847-935-0142                            Abbott Park, IL  60064-3500