sg_req_info_t
sg_req_info_t *rinfo;
#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||