P9_ZC_HDR_SZ
rsize, P9_ZC_HDR_SZ, "dqd",
0, wreq->len, P9_ZC_HDR_SZ, "dqd",
req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, P9_ZC_HDR_SZ, fmt, ap);
if (unlikely(req->rc.size > P9_ZC_HDR_SZ))
req->rc.size = P9_ZC_HDR_SZ;