xprtrdma: Move unmap-safe logic to rpcrdma_marshal_req

Clean up. This logic is related to marshaling the request, and I'd
like to keep everything that touches req->rl_registered close
together, for CPU cache efficiency.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xprtrdma/rpc_rdma.c

@@ -821,6 +821,17 @@ rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst)
 		rtype = rpcrdma_areadch;
 	}
 
+	/* If this is a retransmit, discard previously registered
+	 * chunks. Very likely the connection has been replaced,
+	 * so these registrations are invalid and unusable.
+	 */
+	while (unlikely(!list_empty(&req->rl_registered))) {
+		struct rpcrdma_mw *mw;
+
+		mw = rpcrdma_pop_mw(&req->rl_registered);
+		rpcrdma_defer_mr_recovery(mw);
+	}
+
 	/* This implementation supports the following combinations
 	 * of chunk lists in one RPC-over-RDMA Call message:
 	 *

net/sunrpc/xprtrdma/transport.c

@@ -731,11 +731,6 @@ xprt_rdma_send_request(struct rpc_task *task)
 	if (!xprt_connected(xprt))
 		goto drop_connection;
 
-	/* On retransmit, remove any previously registered chunks */
-	if (unlikely(!list_empty(&req->rl_registered)))
-		r_xprt->rx_ia.ri_ops->ro_unmap_sync(r_xprt,
-						    &req->rl_registered);
-
 	rc = rpcrdma_marshal_req(r_xprt, rqst);
 	if (rc < 0)
 		goto failed_marshal;