[NFS] [Cluster-devel] [PATCH 0/4 Revised] NLM - lock failover

[Neil Brown]

On Friday April 27, jlayton at poochiereds.net wrote:
> On Fri, Apr 27, 2007 at 04:00:13PM +1000, Neil Brown wrote:
> > 
> > So if you need that, then I think it really must be implemented by
> > something a lot like
> >    echo -n /path/name > /proc/fs/nfs/nlm_unlock_filesystem
> > 
> > This is something that we could possible teach "fuser -k" about - so
> > it can effectively 'kill' that part of lockd that is accessing a given
> > filesystem.  It is useful to failover, but definitely useful beyond
> > failover.
> 
> Just a note that I posted a patch ~ a year ago that did precisely that. The
> interface was a little bit different. I had userspace echoing in a dev_t
> number, but it wouldn't be too hard to change it to use a pathname instead.
> 
> Subject was:
> 
>     [PATCH] lockd: add procfs control to cue lockd to release all locks on a device   
> 
> ...if anyone is interested in having me resurrect it.
> 
> -- Jeff

http://lkml.org/lkml/2006/4/10/240

Looks like no-one ever replied.
I probably didn't see it:  things on linux-kernel that don't have
'nfs' or 'raid' (or a few related strings) in the subject have at best
an even chance of me seeing them.  I've just added 'lockd' to the list
of important strings :-)

I would rather a path name, and would rather it came through the
'nfsd' filesystem, but those are fairly trivial changes.

nlm_traverse_files has changed a bit since then, but it should be
easier to unlock based on filesystem with the current code
(especially if we made the first arg a void*..).

NeilBrown