xprtrdma: Replace rpcrdma_rep::rr_buffer with rr_rxprt

Clean up: Instead of carrying a pointer to the buffer pool and
the rpc_xprt, carry a pointer to the controlling rpcrdma_xprt.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Tested-By: Devesh Sharma <devesh.sharma@avagotech.com>
Reviewed-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xprtrdma/rpc_rdma.c

@@ -732,8 +732,8 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
 	struct rpcrdma_msg *headerp;
 	struct rpcrdma_req *req;
 	struct rpc_rqst *rqst;
-	struct rpc_xprt *xprt = rep->rr_xprt;
-	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
+	struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 	__be32 *iptr;
 	int rdmalen, status;
 	unsigned long cwnd;

net/sunrpc/xprtrdma/transport.c

@@ -617,12 +617,9 @@ xprt_rdma_send_request(struct rpc_task *task)
 
 	if (req->rl_reply == NULL) 		/* e.g. reconnection */
 		rpcrdma_recv_buffer_get(req);
-
-	if (req->rl_reply) {
+	/* rpcrdma_recv_buffer_get may have set rl_reply, so check again */
+	if (req->rl_reply)
 		req->rl_reply->rr_func = rpcrdma_reply_handler;
-		/* this need only be done once, but... */
-		req->rl_reply->rr_xprt = xprt;
-	}
 
 	/* Must suppress retransmit to maintain credits */
 	if (req->rl_connect_cookie == xprt->connect_cookie)

net/sunrpc/xprtrdma/verbs.c

@@ -278,6 +278,7 @@ rpcrdma_recvcq_process_wc(struct ib_wc *wc, struct list_head *sched_list)
 {
 	struct rpcrdma_rep *rep =
 			(struct rpcrdma_rep *)(unsigned long)wc->wr_id;
+	struct rpcrdma_ia *ia;
 
 	/* WARNING: Only wr_id and status are reliable at this point */
 	if (wc->status != IB_WC_SUCCESS)
@@ -290,8 +291,9 @@ rpcrdma_recvcq_process_wc(struct ib_wc *wc, struct list_head *sched_list)
 	dprintk("RPC:       %s: rep %p opcode 'recv', length %u: success\n",
 		__func__, rep, wc->byte_len);
 
+	ia = &rep->rr_rxprt->rx_ia;
 	rep->rr_len = wc->byte_len;
-	ib_dma_sync_single_for_cpu(rdmab_to_ia(rep->rr_buffer)->ri_id->device,
+	ib_dma_sync_single_for_cpu(ia->ri_id->device,
 				   rdmab_addr(rep->rr_rdmabuf),
 				   rep->rr_len, DMA_FROM_DEVICE);
 	prefetch(rdmab_to_msg(rep->rr_rdmabuf));
@@ -1053,7 +1055,7 @@ rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
 		goto out_free;
 	}
 
-	rep->rr_buffer = &r_xprt->rx_buf;
+	rep->rr_rxprt = r_xprt;
 	return rep;
 
 out_free:
@@ -1423,7 +1425,7 @@ rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
 void
 rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
 {
-	struct rpcrdma_buffer *buffers = rep->rr_buffer;
+	struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
 	unsigned long flags;
 
 	rep->rr_func = NULL;

net/sunrpc/xprtrdma/xprt_rdma.h

@@ -173,8 +173,7 @@ struct rpcrdma_buffer;
 
 struct rpcrdma_rep {
 	unsigned int		rr_len;
-	struct rpcrdma_buffer	*rr_buffer;
-	struct rpc_xprt		*rr_xprt;
+	struct rpcrdma_xprt	*rr_rxprt;
 	void			(*rr_func)(struct rpcrdma_rep *);
 	struct list_head	rr_list;
 	struct rpcrdma_regbuf	*rr_rdmabuf;