Re: Proposal: restrict link(2)

Chris Adams (
Fri, 13 Dec 1996 13:41:10 -0600 (CST)

Steve VanDevender <> wrote:
>Harald Koenig writes:
>> * clobber other user's disk quoatas, disk usage and disk space accounting

>You have only a cursory understanding of how hard links work.

You don't understand what he is saying.

Say you and I have home directories on the same partition, I can create
hard links to files in your directory under my directory. Since I don't
own those files, they don't count against my quota. Since you own them,
they count against your quota. Now, there is no problem with that,
since the files exist under your directory where you expect them.

Now say you have to pay for disk space. You decide that you have too
much stuff, and delete the files that I have hardlinked. Guess what:
since they still exist, owned by you, under my directory (where you
can't delete them), they still count against your quota, and there is
nothing you can do about that.

So yes, Harald is correct, hard links screw up disk quotas, disk usage
and disk space accounting.

I just realized this the other day as I was planning out how to
implement disk quotas and disk usage billing on my system.

Chris Adams -
System Administrator - Renaissance Internet Services