OP_SEQUENCE
encode_op_hdr(xdr, OP_SEQUENCE, decode_sequence_maxsz, hdr);
status = decode_op_hdr(xdr, OP_SEQUENCE);
if (first_op->opnum == OP_SEQUENCE)
[OP_SEQUENCE] = {
[OP_SEQUENCE] = nfsd4_decode_sequence,
[OP_SEQUENCE] = nfsd4_encode_sequence,