NFSD: Shrink size of struct nfsd4_copy_notify

struct nfsd4_copy_notify is part of struct nfsd4_op, which resides
in an 8-element array.

sizeof(struct nfsd4_op):
Before: /* size: 2208, cachelines: 35, members: 5 */
After:  /* size: 1696, cachelines: 27, members: 5 */
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4proc.c

@@ -1953,9 +1953,9 @@ nfsd4_copy_notify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	/* For now, only return one server address in cpn_src, the
 	 * address used by the client to connect to this server.
 	 */
-	cn->cpn_src.nl4_type = NL4_NETADDR;
+	cn->cpn_src->nl4_type = NL4_NETADDR;
 	status = nfsd4_set_netaddr((struct sockaddr *)&rqstp->rq_daddr,
-				 &cn->cpn_src.u.nl4_addr);
+				 &cn->cpn_src->u.nl4_addr);
 	WARN_ON_ONCE(status);
 	if (status) {
 		nfs4_put_cpntf_state(nn, cps);

fs/nfsd/nfs4xdr.c

@@ -1952,10 +1952,17 @@ nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
 {
 	__be32 status;
 
+	cn->cpn_src = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_src));
+	if (cn->cpn_src == NULL)
+		return nfserr_jukebox;
+	cn->cpn_dst = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_dst));
+	if (cn->cpn_dst == NULL)
+		return nfserr_jukebox;
+
 	status = nfsd4_decode_stateid4(argp, &cn->cpn_src_stateid);
 	if (status)
 		return status;
-	return nfsd4_decode_nl4_server(argp, &cn->cpn_dst);
+	return nfsd4_decode_nl4_server(argp, cn->cpn_dst);
 }
 
 static __be32
@@ -4898,7 +4905,8 @@ nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
 
 	*p++ = cpu_to_be32(1);
 
-	return nfsd42_encode_nl4_server(resp, &cn->cpn_src);
+	nfserr = nfsd42_encode_nl4_server(resp, cn->cpn_src);
+	return nfserr;
 }
 
 static __be32

fs/nfsd/xdr4.h

@@ -595,13 +595,13 @@ struct nfsd4_offload_status {
 struct nfsd4_copy_notify {
 	/* request */
 	stateid_t		cpn_src_stateid;
-	struct nl4_server	cpn_dst;
+	struct nl4_server	*cpn_dst;
 
 	/* response */
 	stateid_t		cpn_cnr_stateid;
 	u64			cpn_sec;
 	u32			cpn_nsec;
-	struct nl4_server	cpn_src;
+	struct nl4_server	*cpn_src;
 };
 
 struct nfsd4_op {