smc_clnt_opts_area_hdr
offsetofend(struct smc_clnt_opts_area_hdr,
struct smc_clnt_opts_area_hdr hdr;
offsetofend(struct smc_clnt_opts_area_hdr, smcd_v2_ext_offset);
offsetof(struct smc_clnt_opts_area_hdr, smcd_v2_ext_offset) +