Re: [PATCH RFC 02/10] nfsd41: sunrpc: Added rpc server-side backchannel handling

[Trond Myklebust <Trond.Myklebust@netapp.com>]

On Mon, 2009-08-24 at 19:34 -0400, J. Bruce Fields wrote:
> On Thu, Aug 20, 2009 at 03:34:23AM +0300, Benny Halevy wrote:
> > From: Rahul Iyer <iyer@netapp.com>
> > 
> > Signed-off-by: Rahul Iyer <iyer@netapp.com>
> > Signed-off-by: Mike Sager <sager@netapp.com>
> > Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
> > Signed-off-by: Benny Halevy <bhalevy@panasas.com>
> > Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
> 
> This patch needs an ACK from Trond.
> 
> > 
> > When the call direction is a reply, copy the xid and call direction into the
> > req->rq_private_buf.head[0].iov_base otherwise rpc_verify_header returns
> > rpc_garbage.
> 
> Looks mostly OK, though blocking the client rpciod on the
> bc_send_request method may be a problem--rpciod normally tries not to
> sleep, and the other send_request methods look like they avoid it.

Agreed. Blocking on sending is unacceptable inside rpciod. Please either
use non-blocking I/O, or use a different thread context for this.


-- 
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@netapp.com
www.netapp.com