[pnfs] [PATCH 5/5] Fix byte order bug in xs_tcp_read_request

[Benny Halevy]

iyer at netapp.com wrote:
> From: Rahul Iyer <iyer at netapp.com>
> 
> Fixed a bug in xs_tcp_read_request. The call/reply flag is in network order and
> not in host order. It needs to be converted to host order before comparisons
> are made. The reason the earlier code worked is because the comparison was
> against RPC_CALL which is defined as 0 (ntohl(0) == 0)
> 
> Signed-off-by: Rahul Iyer <iyer at netapp.com>
> ---
>  net/sunrpc/xprtsock.c |   14 ++++++++------
>  1 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
> index 4d073f9..e48280e 100644
> --- a/net/sunrpc/xprtsock.c
> +++ b/net/sunrpc/xprtsock.c
> @@ -683,16 +683,18 @@ static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc
>  	struct xdr_buf *rcvbuf;
>  	size_t len;
>  	ssize_t r;
> -
> +	u32 calldir;
> +	
>  	/* Find and lock the request corresponding to this xid */
>  	spin_lock(&xprt->transport_lock);
> -	/* XXX Needs a #ifdef for v4.1
> -	 */
> -	if (xprt->tcp_calldir == RPC_CALL) {
> +	calldir = ntohl(xprt->tcp_calldir);
> +	if (calldir == RPC_CALL) {
>  		dprintk("Callback received on backchannel!\n");
>  		spin_unlock(&xprt->transport_lock);
>  
> -		/* Ignore callbacks for now */
> +		 /* We need to create an rpc_rqst for this to read in the

1. extra space character before "/*"
2. I think that according to the  kernel coding style, the text in multi-line comments
   should begin on the second line, not on the first, e.g.:
/*
 * line 1
 * ...
 * line N
 */

> +		 * callback request. Ignore the callback for now.
> +		 */
>  		return;
>  	}
>  	else {
> @@ -756,7 +758,7 @@ static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc
>  	}
>  
>  out:
> -	if (!(xprt->tcp_flags & XPRT_COPY_DATA))
> +	if (!(xprt->tcp_flags & XPRT_COPY_DATA) && (calldir == RPC_REPLY))
>  		xprt_complete_rqst(req->rq_task, xprt->tcp_copied);
>  	spin_unlock(&xprt->transport_lock);
>  	xs_tcp_check_recm(xprt);