[Linux-cluster] GFS
Gradimir Starovic
gradimir at veritas.com
Fri Oct 29 09:13:18 UTC 2004
> > I thought GFS had its gfs_lock file operation, but must say
> my knowledge
> > of GFS is not great. The problem is, how can fcntl locking
> be cluster-wide,
> > for nfs on a cluster, if it's done only locally and the
> cluster fs is
> > not even told about that.
>
> That may have been misleading -- I know very little about nfs's fcntl
> locking and I may not understand your question either. GFS
> does have a
> gfs_lock file operation which makes flock/fcntl locks
> cluster-wide when
> requested through flock() or fcntl() on gfs directly.
>
> However, if the lock is requested on an nfs file (where nfs
> is above gfs),
> that request isn't passed on to gfs AFAIK. This means two nfs servers
> sharing one gfs file system have independent
> (not-cluster-wide) views of
> the locks. So, I think the answer to your question is, fcntl
> locking is
> not cluster wide when it's through nfs.
>
That's what I thought, sorry if my prev mail wasn't clear. I've seen
some versions of nfs code, eg Suse based on 2.6.5, do call f_op->lock().
Don't know the reason this isn't done in 2.6.9, it would be good to have
it working cluster-wide when accessed over nfs as well.
cheers
gradimir
> --
> Dave Teigland <teigland at redhat.com>
>
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