[Cluster-devel] libdlm dlm_ls_lock_wait() doesn't.

[Joel Becker]

On Thu, Mar 20, 2008 at 09:39:02AM -0500, David Teigland wrote:
> On Wed, Mar 19, 2008 at 03:35:11PM -0700, Joel Becker wrote:
> > Folks,
> > 	Another problem I've run into with libdlm - call
> > dlm_ls_lock_wait() on a lock that another node holds, and it returns
> > instead of blocking.  This is not a trylock (LKF_NOQUEUE).  Trylocks
> > work as expected.  A blocking lock attempt does not block, it just
> > fails.  I haven't had the time to nail it yet, so if you get there
> > first, excellent.
> 
> I've tested both threaded and non-threaded dlm_ls_lock_wait() and they
> seem to work for me.  A mistake that I got hung up on for a while was that
> a non-threaded program must link against libdlm_lt, not libdlm.

	libo2dlm is not threaded, so we use libdlm_lt.  I'm getting
EAGAIN returned from dlm_ls_lock_wait() - and this is not a trylock.
I can reproduce with o2dlm_test.  I was about to give you the
instructions on doing so, but I realized it's not trivial - you need the
stack-user kernel modules and to install the tools.

Joel

-- 

"I have never let my schooling interfere with my education."
        - Mark Twain

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127