Re: DoS with POSIX file locks?

J. Bruce Fields
2006-03-20T20:36:00Z

On Mon, Mar 20, 2006 at 05:41:30PM +0100, Miklos Szeredi wrote:
> > > Things look fairly straightforward if the accounting is done in
> > > files_struct instead of task_struct. At least for POSIX locks. I
> > > haven't looked at flocks or leases yet.
> >
> > I was thinking that would work, yes. It might not be worth worrying
> > about accounting for leases/flocks since each process can only have one
> > of those per open file anyway.
>
> Here's a minimally tested patch. The only tricky part is when the
> unlock splits an existing lock in two.
>
> Also the limit checking is sloppy when the lock is split, and in that
> case allows the counter to go one above the limit.

Do you need to handle blocks as well as applied locks?

--b.