Re: st_nlink of directory nodes in shadowfs

[Moritz Schulte]

tb@becket.net (Thomas Bushnell, BSG) writes:

> Oh, well you only need that once.
>
> My thought has always been that an efficient shadow directory would
> scan the underlying directories once on startup, and after that
> would maintain correct information through the change-notification
> mechanism.

Now, that is a completely different approach then the one I used. My
version doesn't remember anything about the states of the underlying
filesystems. Virtual directory nodes are created and freed on the fly
during a lookup. These nodes hold ports to the according underlying
directories, from which that virtual directory should represent the
union. Example: settrans /shadow shadowfs /a /b /c; /a /b and /c
contain the directory 'foo'. If the user looks up the directory
/shadow/foo, the looked up node has ports to /a/foo, /b/foo and
/c/foo.

Implementing that you how suggested would be more or less a rewrite..

        moritz
-- 
Moritz Schulte <moritz@chaosdorf.de> http://www.chaosdorf.de/moritz/
"In short: just say NO TO DRUGS, and maybe you won't end up like
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