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* NFSv4.1 callback service and UDP
@ 2010-12-16 16:19 William A. (Andy) Adamson
  2010-12-16 17:24 ` J. Bruce Fields
  0 siblings, 1 reply; 3+ messages in thread
From: William A. (Andy) Adamson @ 2010-12-16 16:19 UTC (permalink / raw)
  To: J. Bruce Fields; +Cc: Trond Myklebust, NFS list

Hi Bruce

I note that the current NFSv4.1 back channel supports UDP. Why? Should
we continue with UDP support?

Thanks

-->Andy

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: NFSv4.1 callback service and UDP
  2010-12-16 16:19 NFSv4.1 callback service and UDP William A. (Andy) Adamson
@ 2010-12-16 17:24 ` J. Bruce Fields
  2010-12-17 11:21   ` J. Bruce Fields
  0 siblings, 1 reply; 3+ messages in thread
From: J. Bruce Fields @ 2010-12-16 17:24 UTC (permalink / raw)
  To: William A. (Andy) Adamson; +Cc: Trond Myklebust, NFS list

On Thu, Dec 16, 2010 at 11:19:50AM -0500, William A. (Andy) Adamson wrote:
> I note that the current NFSv4.1 back channel supports UDP. Why? Should
> we continue with UDP support?

Have you tested it?

Looks to me like in that case setup_callback_client() will pass
rpc_create() a UDP svc_xprt while requesting protocol
XPRT_TRANSPORT_BC_TCP.  Looking down through the code I'm not sure
what's going to happen.  I doubt it's good....

So, agreed, making sure we error out in the UDP case (if we don't
already) would be a good idea.

--b.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: NFSv4.1 callback service and UDP
  2010-12-16 17:24 ` J. Bruce Fields
@ 2010-12-17 11:21   ` J. Bruce Fields
  0 siblings, 0 replies; 3+ messages in thread
From: J. Bruce Fields @ 2010-12-17 11:21 UTC (permalink / raw)
  To: William A. (Andy) Adamson; +Cc: Trond Myklebust, NFS list

On Thu, Dec 16, 2010 at 12:24:47PM -0500, J. Bruce Fields wrote:
> On Thu, Dec 16, 2010 at 11:19:50AM -0500, William A. (Andy) Adamson wrote:
> > I note that the current NFSv4.1 back channel supports UDP. Why? Should
> > we continue with UDP support?
> 
> Have you tested it?
> 
> Looks to me like in that case setup_callback_client() will pass
> rpc_create() a UDP svc_xprt while requesting protocol
> XPRT_TRANSPORT_BC_TCP.  Looking down through the code I'm not sure
> what's going to happen.  I doubt it's good....

Uh, I realize I'm talking about the NFS server (callback rpc client)
here and you were talking about the NFS client (callback rpc server)?

In any case, no, I don't think there's any reason to support a UDP
backchannel on client or server side.

It would be interesting to test the current code and see what it
actually does in this case.

--b.

> 
> So, agreed, making sure we error out in the UDP case (if we don't
> already) would be a good idea.
> 
> --b.

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2010-12-17 11:21 UTC | newest]

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