svcrdma: Add a "parsed chunk list" data structure

This simple data structure binds the location of each data payload
inside of an RPC message to the chunk that will be used to push it
to or pull it from the client.

There are several benefits to this small additional overhead:

 * It enables support for more than one chunk in incoming Read and
   Write lists.

 * It translates the version-specific on-the-wire format into a
   generic in-memory structure, enabling support for multiple
   versions of the RPC/RDMA transport protocol.

 * It enables the server to re-organize a chunk list if it needs to
   adjust where Read chunk data lands in server memory without
   altering the contents of the XDR-encoded Receive buffer.

Construction of these lists is done while sanity checking each
incoming RPC/RDMA header. Subsequent patches will make use of the
generated data structures.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index f5a3c852bb90..a89d4209fe2a 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -47,6 +47,8 @@
 #include <linux/sunrpc/svcsock.h>
 #include <linux/sunrpc/rpc_rdma.h>
 #include <linux/sunrpc/rpc_rdma_cid.h>
+#include <linux/sunrpc/svc_rdma_pcl.h>
+
 #include <rdma/ib_verbs.h>
 #include <rdma/rdma_cm.h>
 
@@ -142,8 +144,18 @@ struct svc_rdma_recv_ctxt {
 	unsigned int		rc_page_count;
 	unsigned int		rc_hdr_count;
 	u32			rc_inv_rkey;
+
+	struct svc_rdma_pcl	rc_call_pcl;
+
+	struct svc_rdma_pcl	rc_read_pcl;
+
 	__be32			*rc_write_list;
+	struct svc_rdma_chunk	*rc_cur_result_payload;
+	struct svc_rdma_pcl	rc_write_pcl;
+
 	__be32			*rc_reply_chunk;
+	struct svc_rdma_pcl	rc_reply_pcl;
+
 	unsigned int		rc_read_payload_offset;
 	unsigned int		rc_read_payload_length;
 	struct page		*rc_pages[RPCSVC_MAXPAGES];