Re: [PATCH 06/38] svc: Add transport specific xpo_release function

["J. Bruce Fields" <bfields@fieldses.org>]

On Tue, Dec 11, 2007 at 05:32:06PM -0600, Tom Tucker wrote:
> 
> The svc_sock_release function releases pages allocated to a thread. For
> UDP, this also returns the receive skb to the stack.

The stack?  How about just "frees the receive skb"?

> For RDMA it will 
> post a receive WR and bump the client credit count. 
> 
> Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
> ---
> 
>  include/linux/sunrpc/svc.h      |    2 +-
>  include/linux/sunrpc/svc_xprt.h |    1 +
>  net/sunrpc/svcsock.c            |   17 +++++++++--------
>  3 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
> index 37f7448..cfb2652 100644
> --- a/include/linux/sunrpc/svc.h
> +++ b/include/linux/sunrpc/svc.h
> @@ -217,7 +217,7 @@ struct svc_rqst {
>  	struct auth_ops *	rq_authop;	/* authentication flavour */
>  	u32			rq_flavor;	/* pseudoflavor */
>  	struct svc_cred		rq_cred;	/* auth info */
> -	struct sk_buff *	rq_skbuff;	/* fast recv inet buffer */
> +	void *			rq_xprt_ctxt;	/* transport specific context ptr */
>  	struct svc_deferred_req*rq_deferred;	/* deferred request we are replaying */
>  
>  	struct xdr_buf		rq_arg;
> diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
> index 81daa39..e3bd7b1 100644
> --- a/include/linux/sunrpc/svc_xprt.h
> +++ b/include/linux/sunrpc/svc_xprt.h
> @@ -12,6 +12,7 @@
>  struct svc_xprt_ops {
>  	int		(*xpo_recvfrom)(struct svc_rqst *);
>  	int		(*xpo_sendto)(struct svc_rqst *);
> +	void		(*xpo_release_rqst)(struct svc_rqst *);
>  };
>  
>  struct svc_xprt_class {
> diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
> index 9c06b15..b24c084 100644
> --- a/net/sunrpc/svcsock.c
> +++ b/net/sunrpc/svcsock.c
> @@ -185,14 +185,13 @@ svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
>  /*
>   * Release an skbuff after use
>   */
> -static inline void
> -svc_release_skb(struct svc_rqst *rqstp)
> +static void svc_release_skb(struct svc_rqst *rqstp)
>  {
> -	struct sk_buff *skb = rqstp->rq_skbuff;
> +	struct sk_buff *skb = rqstp->rq_xprt_ctxt;
>  	struct svc_deferred_req *dr = rqstp->rq_deferred;
>  
>  	if (skb) {
> -		rqstp->rq_skbuff = NULL;
> +		rqstp->rq_xprt_ctxt = NULL;
>  
>  		dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
>  		skb_free_datagram(rqstp->rq_sock->sk_sk, skb);
> @@ -395,7 +394,7 @@ svc_sock_release(struct svc_rqst *rqstp)
>  {
>  	struct svc_sock	*svsk = rqstp->rq_sock;
>  
> -	svc_release_skb(rqstp);
> +	rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
>  
>  	svc_free_res_pages(rqstp);
>  	rqstp->rq_res.page_len = 0;
> @@ -867,7 +866,7 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
>  			skb_free_datagram(svsk->sk_sk, skb);
>  			return 0;
>  		}
> -		rqstp->rq_skbuff = skb;
> +		rqstp->rq_xprt_ctxt = skb;
>  	}
>  
>  	rqstp->rq_arg.page_base = 0;
> @@ -903,6 +902,7 @@ svc_udp_sendto(struct svc_rqst *rqstp)
>  static struct svc_xprt_ops svc_udp_ops = {
>  	.xpo_recvfrom = svc_udp_recvfrom,
>  	.xpo_sendto = svc_udp_sendto,
> +	.xpo_release_rqst = svc_release_skb,
>  };
>  
>  static struct svc_xprt_class svc_udp_class = {
> @@ -1291,7 +1291,7 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp)
>  		rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
>  	}
>  
> -	rqstp->rq_skbuff      = NULL;
> +	rqstp->rq_xprt_ctxt   = NULL;
>  	rqstp->rq_prot	      = IPPROTO_TCP;
>  
>  	/* Reset TCP read info */
> @@ -1357,6 +1357,7 @@ svc_tcp_sendto(struct svc_rqst *rqstp)
>  static struct svc_xprt_ops svc_tcp_ops = {
>  	.xpo_recvfrom = svc_tcp_recvfrom,
>  	.xpo_sendto = svc_tcp_sendto,
> +	.xpo_release_rqst = svc_release_skb,
>  };
>  
>  static struct svc_xprt_class svc_tcp_class = {
> @@ -1578,7 +1579,7 @@ svc_send(struct svc_rqst *rqstp)
>  	}
>  
>  	/* release the receive skb before sending the reply */
> -	svc_release_skb(rqstp);
> +	rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
>  
>  	/* calculate over-all length */
>  	xb = & rqstp->rq_res;