Re: Error mounting FC8 NFS server with 2.6.31-rc3 NFSv4 client.

From: Trond Myklebust
Date: Wed Jul 22 2009 - 16:20:28 EST


On Wed, 2009-07-22 at 15:49 -0400, Andy Adamson wrote:
> On Jul 21, 2009, at 5:17 PM, Trond Myklebust wrote:
> > Note that there is a bug remaining inside nfs4_init_session(): we
> > shouldn't be copying the rsize/wsize into the nfs_client if the latter
> > was already initialised.
>
> The rsize/wsize is copied into the session prior to the create_session
> call (triggered by the state management code you moved), and is used
> for session negotiation. At this point the nfs_client cl_cons_state is
> set to NFS_CS_SESSION_INITING (see nfs4_alloc_session), so the
> nfs_client is not initialized. The cl_cons_state is set to
> NFS_CS_READY after a successful create_session call.

The call to nfs4_init_session() is in nfs4_create_server(). It can be
called several times _after_ the nfs_client has been initialised when
you mount more than one partition from the same NFS server.

If that is the case, and if you use different rsize/wsize values on
those different mounts, then you will end up clobbering the values of
fc_attrs.max_rqst_sz, and fc_attrs.max_resp_sz, having set them to the
wsize/rsize that was set by the very last mount call.

AFAICS, what you _should_ be doing in nfs4_init_session, is something
like

if (clp->cl_session->fc_attrs.max_rqst_sz < server->wsize)
clp->cl_session->fc_attrs.max_rqst_sz = server->wsize;

Trond

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/