Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uunet!mcsun!hp4nl!star.cs.vu.nl!leendert From: leendert@cs.vu.nl (Leendert van Doorn) Newsgroups: comp.unix.wizards Subject: Re: why can't you exportfs /dir and /dir/sub? Keywords: export exportfs mount NFS subdirectories Message-ID: <10241@star.cs.vu.nl> Date: 18 Jun 91 13:38:51 GMT References: <159281@pyramid.pyramid.com> <1991Jun18.044122.16327@thunder.mcrcim.mcgill.edu> <1991Jun18.115643.629@prl.dec.com> Sender: news@cs.vu.nl Lines: 26 boyd@prl.dec.com (Boyd Roberts) writes: #In article <1991Jun18.044122.16327@thunder.mcrcim.mcgill.edu>, mouse@thunder.mcrcim.mcgill.edu (der Mouse) writes: #> #> Well yes, that's the bug. The question is, why couldn't they fix it? #> # #I guess the bug-fix would violate the stateless protocol :-) Actually it wouldn't. It would only blur the functional division between the mount daemon and the NFS daemon. All the NFS daemon has to do is to enforce the restrictions set in the /etc/export file. It has to check every NFSPROC_LOOKUP operation on "..". This isn't as expensive as it appears: the root-vnodes of the exported file systems should be cached with a special flag, when a lookup is performed and the current vnode has this bit set it should perform the access check. But, as said before, this would break the functional division. Leendert -- Leendert van Doorn Vrije Universiteit / Dept. of Maths. & Comp. Sc. +31 20 5485301 Amoeba project / De Boelelaan 1081A 1081 HV Amsterdam / The Netherlands