Re: [PATCH 0/6 v7] overlay filesystem - request for inclusion

[Miklos Szeredi]

On Tue, 22 Mar 2011, Linus Torvalds wrote:
> On Tue, Mar 22, 2011 at 11:39 AM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
> >
> > Locking analysis would be really nice; AFAICS, it violates locking order
> > when called from e.g. ->setattr()

Locking order is always:

-> overlayfs locks
   -> upper fs locks
   -> lower fs locks

So it's really pretty simple and easy to validate.

> >  and its protection against renames is
> > nowhere near enough. ÂI might be missing something subtle, but...

Protection is exactly as for userspace callers.  AFAICT.

> Miklos - have you tried using this with lockdep (together with the
> same filesystems mounted natively too)? I'd expect that that should
> show any bad lock usage..

Ah, lockdep.  I have tried, but there seems to be always something
that triggers it at boot time on my laptop, which makes it useless.  I
could find some other machine to test this on, though.

Thanks,
Miklos
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