NFS4_MAXTAGLEN
WARN_ON_ONCE(hdr->taglen > NFS4_MAXTAGLEN);
#define compound_encode_hdr_maxsz (3 + (NFS4_MAXTAGLEN >> 2))
#define compound_decode_hdr_maxsz (3 + (NFS4_MAXTAGLEN >> 2))
#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))