Date: Tue, 5 Aug 2003 01:34:25 +0200
From: Stephan von Krawczynski <skraw@ithnet.com>
To: Jesse Pollard <jesse@cats-chateau.net>
Cc: aia21@cam.ac.uk, aebr@win.tue.nl, linux-kernel@vger.kernel.org
Subject: Re: FS: hardlinks on directories
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On Mon, 4 Aug 2003 16:16:39 -0500
Jesse Pollard <jesse@cats-chateau.net> wrote:

> > > You ask for examples of applications?  There are millions!  Anything that
> > > walks the directory tree for a start, e.g. ls -R, find, locatedb, medusa,
> > > du, any type of search and/or indexing engine, chown -R, cp -R, scp
> > > -R, chmod -R, etc...
> >
> > There is a flaw in this argument. If I am told that mount --bind does just
> > about what I want to have as a feature then these applictions must have the
> > same problems already (if I mount braindead). So an implementation in fs
> > cannot do any _additional_ damage to these applications, or not?
> 
> Mount -bind only modifies the transient memory storage of a directory. It 
> doesn't change the filesystem. Each bind occupies memory, and on a reboot, 
> the bind is gone.

What kind of an argument is this? What difference can you see between a
transient loop and a permanent loop for the applications? Exactly zero I guess.
In my environments nil boots ought to happen. 
This is the reason why I would in fact be satisfied with mount -bind if only I
could export it via nfs...

> > My saying is not "I want to have hardlinks for creating a big mess of loops
> > inside my filesystems". Your view simply drops the fact that there are more
> > possibilities to create and use hardlinks without any loops...
> 
> been there done that, is is a "big mess of loops".
> 
> And you can't prevent the loops either, without scanning the entire graph, or
> keeping a graph location reference embeded with the file.

Or marking the links as type links somehow.

> Which then breaks "mv" for renaming directories... It would then have to
> scan the entire graph again to locate a possble creation of a loop, and 
> regenerate the graph location for every file.

There should be no difference if only a hardlink is simply marked as such by
any kind of marker you possibly can think of.

Regards,
Stephan
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