Re: Named streams, Re: Cleaning up namei

[der Mouse <mouse%Rodents.Montreal.QC.CA@localhost>]

>> Mac OS used to have "complex" vnodes, which were files that had
>> named forks.  They acted like files, but you could do lookups on
>> them.  Mac OS no longer has them, so I consider them a dead
>> experiment. ;-)
> But there's no reason they should be prohibited by the VFS layer.

I spent the second half of 2002 writing impedance-matching glue code so
that a research project could be mounted as a filesystem.  It ended up
with something very similar: files were, well, files, but if you
treated one like a directory it worked like a directory, exposing some
of the internal data structures that were important to the underlying
research project but which didn't fit the Unix filesystem model any
better than MacOS named forks do.

I'm not sure whether this constitutes an argument NetBSD wants to pay
attention to, but, if they're still using anything like my code, there
is someone out there taking advantage of this capability right now.

In case it's not clear, I come down in favour of allowing filesystems
to do things like make lookups succeed in circumstances like these
where a traditional filesystem would throw ENOTDIR.  FWTMBW. :)

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