NFSD: Add a Call equivalent to the NFSD_TRACE_PROC_RES macros

Introduce tracing helpers that can be used before the procedure
status code is known. These macros are similar to the
SVC_RQST_ENDPOINT helpers, but they can be modified to include
NFS-specific fields if that is needed later.

Reviewed-by: Jeff Layton <[e-mail]>
Signed-off-by: Chuck Lever <[e-mail]>

fs/nfsd/trace.h

···
 #include "nfsfh.h"
 #include "xdr4.h"
 
+#define NFSD_TRACE_PROC_CALL_FIELDS(r) \
+		__field(unsigned int, netns_ino) \
+		__field(u32, xid) \
+		__sockaddr(server, (r)->rq_xprt->xpt_locallen) \
+		__sockaddr(client, (r)->rq_xprt->xpt_remotelen)
+
+#define NFSD_TRACE_PROC_CALL_ASSIGNMENTS(r) \
+		do { \
+			struct svc_xprt *xprt = (r)->rq_xprt; \
+			__entry->netns_ino = SVC_NET(r)->ns.inum; \
+			__entry->xid = be32_to_cpu((r)->rq_xid); \
+			__assign_sockaddr(server, &xprt->xpt_local, \
+					  xprt->xpt_locallen); \
+			__assign_sockaddr(client, &xprt->xpt_remote, \
+					  xprt->xpt_remotelen); \
+		} while (0)
+
 #define NFSD_TRACE_PROC_RES_FIELDS(r) \
 		__field(unsigned int, netns_ino) \
 		__field(u32, xid) \