rpcrdma: Fix comments about reverse-direction operation

During the final stages of publication of RFC 8167, reviewers
requested that we use the term "reverse direction" rather than
"backwards direction". Update comments to reflect this preference.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xprtrdma/backchannel.c

@@ -2,7 +2,7 @@
 /*
  * Copyright (c) 2015-2020, Oracle and/or its affiliates.
  *
- * Support for backward direction RPCs on RPC/RDMA.
+ * Support for reverse-direction RPCs on RPC/RDMA.
  */
 
 #include <linux/sunrpc/xprt.h>
@@ -208,7 +208,7 @@ static struct rpc_rqst *rpcrdma_bc_rqst_get(struct rpcrdma_xprt *r_xprt)
 }
 
 /**
- * rpcrdma_bc_receive_call - Handle a backward direction call
+ * rpcrdma_bc_receive_call - Handle a reverse-direction Call
  * @r_xprt: transport receiving the call
  * @rep: receive buffer containing the call
  *

net/sunrpc/xprtrdma/rpc_rdma.c

@@ -1151,14 +1151,10 @@ rpcrdma_is_bcall(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep)
 	 */
 	p = xdr_inline_decode(xdr, 3 * sizeof(*p));
 	if (unlikely(!p))
-		goto out_short;
+		return true;
 
 	rpcrdma_bc_receive_call(r_xprt, rep);
 	return true;
-
-out_short:
-	pr_warn("RPC/RDMA short backward direction call\n");
-	return true;
 }
 #else	/* CONFIG_SUNRPC_BACKCHANNEL */
 {

net/sunrpc/xprtrdma/svc_rdma_backchannel.c

@@ -2,7 +2,7 @@
 /*
  * Copyright (c) 2015-2018 Oracle.  All rights reserved.
  *
- * Support for backward direction RPCs on RPC/RDMA (server-side).
+ * Support for reverse-direction RPCs on RPC/RDMA (server-side).
  */
 
 #include <linux/sunrpc/svc_rdma.h>
@@ -59,7 +59,7 @@ void svc_rdma_handle_bc_reply(struct svc_rqst *rqstp,
 	spin_unlock(&xprt->queue_lock);
 }
 
-/* Send a backwards direction RPC call.
+/* Send a reverse-direction RPC Call.
  *
  * Caller holds the connection's mutex and has already marshaled
  * the RPC/RDMA request.

net/sunrpc/xprtrdma/xprt_rdma.h

@@ -98,9 +98,9 @@ struct rpcrdma_ep {
 	atomic_t		re_completion_ids;
 };
 
-/* Pre-allocate extra Work Requests for handling backward receives
- * and sends. This is a fixed value because the Work Queues are
- * allocated when the forward channel is set up, long before the
+/* Pre-allocate extra Work Requests for handling reverse-direction
+ * Receives and Sends. This is a fixed value because the Work Queues
+ * are allocated when the forward channel is set up, long before the
  * backchannel is provisioned. This value is two times
  * NFS4_DEF_CB_SLOT_TABLE_SIZE.
  */