xprtrdma: Remove BOUNCEBUFFERS memory registration mode

Clean up: This memory registration mode is slow and was never
meant for use in production environments. Remove it to reduce
implementation complexity.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xprtrdma/rpc_rdma.c

@@ -77,9 +77,6 @@ static const char transfertypes[][12] = {
  * Prepare the passed-in xdr_buf into representation as RPC/RDMA chunk
  * elements. Segments are then coalesced when registered, if possible
  * within the selected memreg mode.
- *
- * Note, this routine is never called if the connection's memory
- * registration strategy is 0 (bounce buffers).
  */
 
 static int
@@ -439,14 +436,6 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 		wtype = rpcrdma_noch;
 	BUG_ON(rtype != rpcrdma_noch && wtype != rpcrdma_noch);
 
-	if (r_xprt->rx_ia.ri_memreg_strategy == RPCRDMA_BOUNCEBUFFERS &&
-	    (rtype != rpcrdma_noch || wtype != rpcrdma_noch)) {
-		/* forced to "pure inline"? */
-		dprintk("RPC:       %s: too much data (%d/%d) for inline\n",
-			__func__, rqst->rq_rcv_buf.len, rqst->rq_snd_buf.len);
-		return -1;
-	}
-
 	hdrlen = 28; /*sizeof *headerp;*/
 	padlen = 0;
 

net/sunrpc/xprtrdma/transport.c

@@ -503,18 +503,6 @@ xprt_rdma_allocate(struct rpc_task *task, size_t size)
 		 * If the allocation or registration fails, the RPC framework
 		 * will (doggedly) retry.
 		 */
-		if (rpcx_to_rdmax(xprt)->rx_ia.ri_memreg_strategy ==
-				RPCRDMA_BOUNCEBUFFERS) {
-			/* forced to "pure inline" */
-			dprintk("RPC:       %s: too much data (%zd) for inline "
-					"(r/w max %d/%d)\n", __func__, size,
-					rpcx_to_rdmad(xprt).inline_rsize,
-					rpcx_to_rdmad(xprt).inline_wsize);
-			size = req->rl_size;
-			rpc_exit(task, -EIO);		/* fail the operation */
-			rpcx_to_rdmax(xprt)->rx_stats.failed_marshal_count++;
-			goto out;
-		}
 		if (task->tk_flags & RPC_TASK_SWAPPER)
 			nreq = kmalloc(sizeof *req + size, GFP_ATOMIC);
 		else
@@ -543,7 +531,6 @@ xprt_rdma_allocate(struct rpc_task *task, size_t size)
 		req = nreq;
 	}
 	dprintk("RPC:       %s: size %zd, request 0x%p\n", __func__, size, req);
-out:
 	req->rl_connect_cookie = 0;	/* our reserved value */
 	return req->rl_xdr_buf;
 

net/sunrpc/xprtrdma/verbs.c

@@ -557,7 +557,6 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 	 * adapter.
 	 */
 	switch (memreg) {
-	case RPCRDMA_BOUNCEBUFFERS:
 	case RPCRDMA_REGISTER:
 	case RPCRDMA_FRMR:
 		break;
@@ -778,9 +777,7 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 
 	/* Client offers RDMA Read but does not initiate */
 	ep->rep_remote_cma.initiator_depth = 0;
-	if (ia->ri_memreg_strategy == RPCRDMA_BOUNCEBUFFERS)
+	if (devattr.max_qp_rd_atom > 32)	/* arbitrary but <= 255 */
-		ep->rep_remote_cma.responder_resources = 0;
-	else if (devattr.max_qp_rd_atom > 32)	/* arbitrary but <= 255 */
 		ep->rep_remote_cma.responder_resources = 32;
 	else
 		ep->rep_remote_cma.responder_resources = devattr.max_qp_rd_atom;