Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!samsung!spool.mu.edu!munnari.oz.au!djh
From: djh@cs.mu.oz.au (David Hornsby)
Newsgroups: comp.protocols.appletalk
Subject: Re: System 7.0 AppleShare and Aufs problem
Message-ID: <7374@munnari.oz.au>
Date: 16 Apr 91 15:33:15 GMT
References: <9104121604.AA04153@aquarium.ecn.purdue.edu>
Organization: Comp Sci, Melbourne Uni, Australia
Lines: 24

moyman@ECN.PURDUE.EDU (Mike Moya) writes:
> There is a definite problem with System 7.0 and Aufs (Rutgers 2.0 version).

This is also a problem with System 7.0 (at least to beta 4) and CAP 6.0.
It is due to a couple of things:
	
	1. AppleShare now creates an invisible folder on the AppleShare
	server called "Network Trash Folder". When you try to delete
	something by dropping it in the Trash Can, the AppleShare code
	tries to byte-range-lock a zero-length file that it has open
	READ-ONLY. The file is called "Trash Can Usage Map".

	2. CAP uses UNIX lockf(2) for byte-range-locking. The restriction
	is that the file must also be open for writing. I used to believe
	that no-one would ever even consider trying to byte-range lock
	a read-only file (although it's legal in AFP). I was wrong!

	3. The Mac-end recovery from the lock failure consists of retrying
	the lock, seemingly ad infinitum (I timed out).

I have a gross patch for CAP (any flavour) that lets it work with System 7.0.
Hopefully something more elegant will be possible soon ...

 - David.