Jason Thorpe <thorpej@shagadelic.org> writes:

> On Oct 19, 2005, at 11:38 AM, Bill Studenmund wrote:
>
>> If you wanted to go the pseudo filename route, you could make a fake
>> directory in the root (hooking into VOP_LOOKUP(). For any lookup in
>> that
>> directory, you just do an unmapping of hex-dump-file-handle, and call
>> VFS_FHTOVP() on your mount point.
>
> FWIW... Mac OS X has something called "volfs" which is ... very much
> like this (some of the details are different, but it basically the
> same idea).  Carbon uses it to provide old Mac OS-style file access
> semantics.

They also got the permission check more or less right; that is, in the
exactly-one-parent case, lacking execute permission on any ancestor of
a file will prevent accessing it by number via volfs.

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