1 files changed, 29 insertions, 42 deletions

diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
index ff1df40f0d26..c676ed0efb5a 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
@@ -12,7 +12,17 @@
 
 #undef SVCRDMA_BACKCHANNEL_DEBUG
 
-int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, struct rpcrdma_msg *rmsgp,
+/**
+ * svc_rdma_handle_bc_reply - Process incoming backchannel reply
+ * @xprt: controlling backchannel transport
+ * @rdma_resp: pointer to incoming transport header
+ * @rcvbuf: XDR buffer into which to decode the reply
+ *
+ * Returns:
+ *	%0 if @rcvbuf is filled in, xprt_complete_rqst called,
+ *	%-EAGAIN if server should call ->recvfrom again.
+ */
+int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, __be32 *rdma_resp,
 			     struct xdr_buf *rcvbuf)
 {
 	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
@@ -27,13 +37,13 @@ int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, struct rpcrdma_msg *rmsgp,
 
 	p = (__be32 *)src->iov_base;
 	len = src->iov_len;
-	xid = rmsgp->rm_xid;
+	xid = *rdma_resp;
 
 #ifdef SVCRDMA_BACKCHANNEL_DEBUG
 	pr_info("%s: xid=%08x, length=%zu\n",
 		__func__, be32_to_cpu(xid), len);
 	pr_info("%s: RPC/RDMA: %*ph\n",
-		__func__, (int)RPCRDMA_HDRLEN_MIN, rmsgp);
+		__func__, (int)RPCRDMA_HDRLEN_MIN, rdma_resp);
 	pr_info("%s:      RPC: %*ph\n",
 		__func__, (int)len, p);
 #endif
@@ -53,7 +63,7 @@ int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, struct rpcrdma_msg *rmsgp,
 		goto out_unlock;
 	memcpy(dst->iov_base, p, len);
 
-	credits = be32_to_cpu(rmsgp->rm_credit);
+	credits = be32_to_cpup(rdma_resp + 2);
 	if (credits == 0)
 		credits = 1;	/* don't deadlock */
 	else if (credits > r_xprt->rx_buf.rb_bc_max_requests)
@@ -90,9 +100,9 @@ out_notfound:
  * Caller holds the connection's mutex and has already marshaled
  * the RPC/RDMA request.
  *
- * This is similar to svc_rdma_reply, but takes an rpc_rqst
- * instead, does not support chunks, and avoids blocking memory
- * allocation.
+ * This is similar to svc_rdma_send_reply_msg, but takes a struct
+ * rpc_rqst instead, does not support chunks, and avoids blocking
+ * memory allocation.
  *
  * XXX: There is still an opportunity to block in svc_rdma_send()
  * if there are no SQ entries to post the Send. This may occur if
@@ -101,59 +111,36 @@ out_notfound:
 static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma,
 			      struct rpc_rqst *rqst)
 {
-	struct xdr_buf *sndbuf = &rqst->rq_snd_buf;
 	struct svc_rdma_op_ctxt *ctxt;
-	struct svc_rdma_req_map *vec;
-	struct ib_send_wr send_wr;
 	int ret;
 
-	vec = svc_rdma_get_req_map(rdma);
-	ret = svc_rdma_map_xdr(rdma, sndbuf, vec, false);
-	if (ret)
+	ctxt = svc_rdma_get_context(rdma);
+
+	/* rpcrdma_bc_send_request builds the transport header and
+	 * the backchannel RPC message in the same buffer. Thus only
+	 * one SGE is needed to send both.
+	 */
+	ret = svc_rdma_map_reply_hdr(rdma, ctxt, rqst->rq_buffer,
+				     rqst->rq_snd_buf.len);
+	if (ret < 0)
 		goto out_err;
 
 	ret = svc_rdma_repost_recv(rdma, GFP_NOIO);
 	if (ret)
 		goto out_err;
 
-	ctxt = svc_rdma_get_context(rdma);
-	ctxt->pages[0] = virt_to_page(rqst->rq_buffer);
-	ctxt->count = 1;
-
-	ctxt->direction = DMA_TO_DEVICE;
-	ctxt->sge[0].lkey = rdma->sc_pd->local_dma_lkey;
-	ctxt->sge[0].length = sndbuf->len;
-	ctxt->sge[0].addr =
-	    ib_dma_map_page(rdma->sc_cm_id->device, ctxt->pages[0], 0,
-			    sndbuf->len, DMA_TO_DEVICE);
-	if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr)) {
-		ret = -EIO;
-		goto out_unmap;
-	}
-	svc_rdma_count_mappings(rdma, ctxt);
-
-	memset(&send_wr, 0, sizeof(send_wr));
-	ctxt->cqe.done = svc_rdma_wc_send;
-	send_wr.wr_cqe = &ctxt->cqe;
-	send_wr.sg_list = ctxt->sge;
-	send_wr.num_sge = 1;
-	send_wr.opcode = IB_WR_SEND;
-	send_wr.send_flags = IB_SEND_SIGNALED;
-
-	ret = svc_rdma_send(rdma, &send_wr);
-	if (ret) {
-		ret = -EIO;
+	ret = svc_rdma_post_send_wr(rdma, ctxt, 1, 0);
+	if (ret)
 		goto out_unmap;
-	}
 
 out_err:
-	svc_rdma_put_req_map(rdma, vec);
 	dprintk("svcrdma: %s returns %d\n", __func__, ret);
 	return ret;
 
 out_unmap:
 	svc_rdma_unmap_dma(ctxt);
 	svc_rdma_put_context(ctxt, 1);
+	ret = -EIO;
 	goto out_err;
 }