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Subject: [PATCH RFC 11/12] xprtrdma: Refactor chunk encoding
From:   Chuck Lever <chuck.lever@oracle.com>
To:     linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org
Date:   Tue, 28 May 2019 14:21:48 -0400
Message-ID: <20190528182148.19012.78763.stgit@manet.1015granger.net>
In-Reply-To: <20190528181018.19012.61210.stgit@manet.1015granger.net>
References: <20190528181018.19012.61210.stgit@manet.1015granger.net>
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Clean up.

Move the "not present" case into the individual chunk encoders. This
improves code organization and readability.

The reason for the original organization was to optimize for the
case where there there are no chunks. The optimization turned out to
be inconsequential.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/xprtrdma/rpc_rdma.c |   36 ++++++++++++++++--------------------
 1 file changed, 16 insertions(+), 20 deletions(-)

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 6de90d4..310614f 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -366,6 +366,9 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
 	unsigned int pos;
 	int nsegs;
 
+	if (rtype == rpcrdma_noch)
+		goto done;
+
 	pos = rqst->rq_snd_buf.head[0].iov_len;
 	if (rtype == rpcrdma_areadch)
 		pos = 0;
@@ -389,7 +392,8 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
 		nsegs -= mr->mr_nents;
 	} while (nsegs);
 
-	return 0;
+done:
+	return encode_item_not_present(xdr);
 }
 
 /* Register and XDR encode the Write list. Supports encoding a list
@@ -417,6 +421,9 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
 	int nsegs, nchunks;
 	__be32 *segcount;
 
+	if (wtype != rpcrdma_writech)
+		goto done;
+
 	seg = req->rl_segments;
 	nsegs = rpcrdma_convert_iovs(r_xprt, &rqst->rq_rcv_buf,
 				     rqst->rq_rcv_buf.head[0].iov_len,
@@ -451,7 +458,8 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
 	/* Update count of segments in this Write chunk */
 	*segcount = cpu_to_be32(nchunks);
 
-	return 0;
+done:
+	return encode_item_not_present(xdr);
 }
 
 /* Register and XDR encode the Reply chunk. Supports encoding an array
@@ -476,6 +484,9 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
 	int nsegs, nchunks;
 	__be32 *segcount;
 
+	if (wtype != rpcrdma_replych)
+		return encode_item_not_present(xdr);
+
 	seg = req->rl_segments;
 	nsegs = rpcrdma_convert_iovs(r_xprt, &rqst->rq_rcv_buf, 0, wtype, seg);
 	if (nsegs < 0)
@@ -859,28 +870,13 @@ static bool rpcrdma_prepare_msg_sges(struct rpcrdma_xprt *r_xprt,
 	 * send a Call message with a Position Zero Read chunk and a
 	 * regular Read chunk at the same time.
 	 */
-	if (rtype != rpcrdma_noch) {
-		ret = rpcrdma_encode_read_list(r_xprt, req, rqst, rtype);
-		if (ret)
-			goto out_err;
-	}
-	ret = encode_item_not_present(xdr);
+	ret = rpcrdma_encode_read_list(r_xprt, req, rqst, rtype);
 	if (ret)
 		goto out_err;
-
-	if (wtype == rpcrdma_writech) {
-		ret = rpcrdma_encode_write_list(r_xprt, req, rqst, wtype);
-		if (ret)
-			goto out_err;
-	}
-	ret = encode_item_not_present(xdr);
+	ret = rpcrdma_encode_write_list(r_xprt, req, rqst, wtype);
 	if (ret)
 		goto out_err;
-
-	if (wtype != rpcrdma_replych)
-		ret = encode_item_not_present(xdr);
-	else
-		ret = rpcrdma_encode_reply_chunk(r_xprt, req, rqst, wtype);
+	ret = rpcrdma_encode_reply_chunk(r_xprt, req, rqst, wtype);
 	if (ret)
 		goto out_err;