[pnfs] [PATCH 1/1] nfs41: Skip past the RPC call direction

[Benny Halevy]

Ricardo, thanks for the patch (and the explanation)!
I'll apply it later today after testing the 2.6.26-based
tree.

Benny

On Jul. 15, 2008, 7:14 +0300, Ricardo Labiaga <ricardo.labiaga at netapp.com> wrote:
> From: Ricardo Labiaga <Ricardo.Labiaga at netapp.com>
> 
> xs_tcp_read_calldir() is now responsible for reading the RPC call
> direction and determining whether it is a reply or a callback request.
> The call to xdr_skb_read_bits() inside xs_tcp_read_calldir() moves the
> xdr_skb_reader offset past the RPC call direction (offset should be
> equal to 8).  Therefore xs_tcp_read_common() called from
> xs_tcp_ready_reply() should be copying the TCP buffer starting past the
> RPC call direction.  It is now necessary to read the RPC call direction
> earlier to determine whether to call the reply handler or the callback
> handler.
> 
> call_verify() should therefore skip past the XID and call/reply flag.
> 
> Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga at netapp.com>
> ---
>  net/sunrpc/clnt.c |   13 +++++++------
>  1 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
> index e9a19a9..087c177 100644
> --- a/net/sunrpc/clnt.c
> +++ b/net/sunrpc/clnt.c
> @@ -1415,13 +1415,14 @@ call_verify(struct rpc_task *task)
>  	}
>  	if ((len -= 3) < 0)
>  		goto out_overflow;
> -	p += 1;	/* skip XID */
>  
> -	if ((n = ntohl(*p++)) != RPC_REPLY) {
> -		dprintk("RPC: %5u %s: not an RPC reply: %x\n",
> -				task->tk_pid, __func__, n);
> -		/* goto out_garbage; */	/* FIXME: needed for nfs41, not sure why... */
> -	}
> +	/*
> +	 * Skip the XID and call direction.
> +	 * The underlying transport has read the XID and RPC call direction
> +	 * to determine this is an RPC reply.
> +	 */
> +	p += 2;
> +
>  	if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
>  		if (--len < 0)
>  			goto out_overflow;