rec_hdr_fmt_size
strlen(rec_hdr_str) + rec_hdr_fmt_size * control->ras_num_recs;
u8 data[rec_hdr_fmt_size + 1];
s = s / rec_hdr_fmt_size;
r = r % rec_hdr_fmt_size;
data_len = min_t(size_t, rec_hdr_fmt_size - r, size);