Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!uunet!auspex!guy
From: guy@auspex.UUCP (Guy Harris)
Newsgroups: comp.unix.wizards
Subject: Re: Making rm undoable
Message-ID: <1301@auspex.UUCP>
Date: 27 Mar 89 00:20:39 GMT
References: <6805@phoenix.Princeton.EDU> <7360@phoenix.Princeton.EDU> <10113@bloom-beacon.MIT.EDU>
Reply-To: guy@auspex.UUCP (Guy Harris)
Distribution: usa
Organization: Auspex Systems, Santa Clara
Lines: 23

>Keeping a file open also does nothing under NFS -- there's no state,
>so the NFS server doesn't realize that the file is open and it will go
>away.  I hear that the next version of NFS supplies the capability to
>do file locking, but I don't know if this includes keeping track of
>busy files.

I'm not sure what you mean by "the next version of NFS".  The *current*
version of the ONC/NFS source as distributed by Sun includes a network
service to perform byte-span locking (which subsumes file locking) over
the network; said service is different from the file access service that
NFS refers to in the strict sense.  I think the previous version of the
ONC/NFS source had it as well. 

The next version of the NFS *protocol* doesn't include support for
byte-span locking; that's still left up to a separate service and
protocol.

Since the locking is a separate service, and since it's accessed on
typical UNIX implementations only through the "fcntl" system call
(POSIX/SVID-style), neither Version 2 (the current version of the
protocol) nor Version 3 (the next version of the protocol) of the NFS
service keeps track of files that a client has open, so no, this doesn't
include keeping track of busy files.