NFS: SETCLIENTID XDR buffer sizes are incorrect

Use the correct calculation of the maximum size of a clientaddr4
when encoding and decoding SETCLIENTID operations. clientaddr4 is
defined in section 2.2.10 of RFC3530bis-31.

The usage in encode_setclientid_maxsz is missing the 4-byte length
in both strings, but is otherwise correct. decode_setclientid_maxsz
simply asks for a page of receive buffer space, which is
unnecessarily large (more than 4KB).

Note that a SETCLIENTID reply is either clientid+verifier, or
clientaddr4, depending on the returned NFS status. It doesn't
hurt to allocate enough space for both.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs4xdr.c

@@ -141,13 +141,15 @@ static int nfs4_stat_to_errno(int);
 				XDR_QUADLEN(NFS4_VERIFIER_SIZE) + \
 				XDR_QUADLEN(NFS4_SETCLIENTID_NAMELEN) + \
 				1 /* sc_prog */ + \
-				XDR_QUADLEN(RPCBIND_MAXNETIDLEN) + \
-				XDR_QUADLEN(RPCBIND_MAXUADDRLEN) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN) + \
 				1) /* sc_cb_ident */
 #define decode_setclientid_maxsz \
 				(op_decode_hdr_maxsz + \
-				2 + \
-				1024) /* large value for CLID_INUSE */
+				2 /* clientid */ + \
+				XDR_QUADLEN(NFS4_VERIFIER_SIZE) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
 #define encode_setclientid_confirm_maxsz \
 				(op_encode_hdr_maxsz + \
 				3 + (NFS4_VERIFIER_SIZE >> 2))