[RFC,PATCH 0/4] Dynamic Pseudo Root

[Steve Dickson]

Brent Callaghan wrote:
> This seems like a very complicated way to implement a pseudo root.
I'm sure my works make sound more complicated that it is... :-\

The mapping approach is pretty simple. Basically create mount
point for all the exports, which in turn, enables the kernel
mount crossover code to do the right thing when the mount point 
is accessed. I guess its the overhead to make that happen is 
where all the complicity comes in... 

> 
> Why not implement it the same way as Solaris does it ?
> 
> When a Solaris NFSv4 server gets a PUTROOTFH it returns the client
> the real filehandle for the real system root.  In fact, all  
> filesystems that
> may provide a path to a real export are automatically exported, albeit
> with some simple restrictions:
So can I assume that Solaris does pump all the exports to a table
in the kernel?

> 	
> 	o LOOKUPs succeed only for path components that lead to
> 	   exported filesystems.
> 
> 	o READDIR shows only path components that lead to exported
> 	   filesystems.
With the mapping approach, the LOOKUPS and READDIRS automagically 
return the correct components because only the exported components
exist in the root. Meaning no changes (i.e. checks) are needed
in the actual server code. 

> 
> The pseudo filesystem is the same as the real filesystem, with
> some restrictions.
Does Solaris have some type of mechanism that allows the pseudo 
filesystem something other than the real root?

> 
> The code to implement this was pretty straightforward.
Being straightforward.... is *always* a good thing... :-)


steved.