[Ocfs2-devel] [PATCH] ocfs2: fix __ocfs2_cluster_lock() dead lock

[David Teigland]

On Wed, Jan 13, 2010 at 11:14:48AM -0800, Sunil Mushran wrote:
> Joel Becker wrote:
> >On Wed, Jan 13, 2010 at 11:20:49AM +0800, Wengang Wang wrote:
> >>before update_holders, the lock could be DCed(since no BUSY flag set by
> >>here).
> >>
> >>and even after update_holders, the lock could be DCed too.
> >>
> >>so that we get ocfs2_cluster_lock()(with holders increased) returned 
> >>sucessfully
> >>but actually we don't hold the dlm lock. --thus more than one node is
> >>considering that they have the (EX) lock.
> >
> >	You make a good point.  I don't like the solution you propose,
> >though.  Another flag that's almost the same?  Eww!  There's got to be a
> >better way.
> 
> I don't see how we can resolve this without another flag. It could
> be a mirror image of the PENDING flag. PENDING takes care of the gap
> between BUSY set and calling dlm_lock(). This flag has to take care
> of the gap between BUSY clear and inc_holders.
> 
> Am working on improving Wengang's patch.

I'm afraid I lost track of which patches I should be trying.  Is there
something that we expect should solve the known problems, even if it's not
a final version?
Dave