Return to BSD News archive
Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!howland.erols.net!EU.net!usenet2.news.uk.psi.net!uknet!usenet1.news.uk.psi.net!uknet!dispatch.news.demon.net!demon!awfulhak.demon.co.uk!awfulhak.demon.co.uk!awfulhak.demon.co.uk!not-for-mail
From: brian@anorak.coverform.lan (Brian Somers)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: dummy question
Date: 22 Oct 1996 11:37:37 +0100
Organization: Coverform Ltd.
Lines: 34
Sender: brian@awfulhak.demon.co.uk
Message-ID: <54i85h$1tb@anorak.coverform.lan>
References: <53mfdu$1iv@wa4phy.async.com> <543o1d$pe0@newsbr.eunet.fr>
<546jmr$1ks@anorak.coverform.lan> <5495rd$c8@uriah.heep.sax.de>
Reply-To: brian@awfulhak.demon.co.uk
NNTP-Posting-Host: anorak.coverform.lan
X-NNTP-Posting-Host: awfulhak.demon.co.uk
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Newsreader: knews 0.9.8
In article <5495rd$c8@uriah.heep.sax.de>,
j@uriah.heep.sax.de (J Wunsch) writes:
: brian@anorak.coverform.lan (Brian Somers) wrote:
:
>> This sounds like the "ln -f" option on Sequent Dynix boxes. It allows
>> you to hard-link directory entries ;)
:
: FreeBSD did have it until very recently, too. It was undocumented and
: called -F there. It's still available in 2.1.5R, but no longer in
: 2.2-current (after a fairly long debate). By the same time, the
: syscall-level support for hardlinking and unlinking directories has
: also been killed. (Btw., the counterpart unlink(8) was missing all
: the time before. You gotta write it yourself if you have accidentally
: used ln -F. It's a six-liner only, however.)
The nasty bit about -f on Sequent was that after linking another name
to the directory entry, you ended up with a directory node that has
3 links. I couldn't find *anything* that would remove it - except clri.
unlink only does directories w/ a link count of 2 (on Sequent anyway) !
The problem is that unlink must have a special "I'm a directory" case
where it's allowed to free an inode with a 2 count if it's an empty
directory (only . & ..). The Sequent unlink didn't have any logic
that said "if the link count > 2, decrement it and remove the entry
from the parent directory file. It probably figured that a link count
greater than 2 implies that there are subdirectories - therefore unlink
fails :(
--
Brian <brian@awfulhak.demon.co.uk>
<http://www.awfulhak.demon.co.uk/>
Don't _EVER_ lose your sense of humour....
.