struct lock_req {
       string req_filename = 1;
       struct[lock] req_lock = 2;
}

struct lock_rep {
       int result = 1;
       int64 rangestart = 2;
}

struct lock {
       int locktype = 1; /* LT_SHAREMODE or LT_BRL (brl means UNIX byterange lock) */
       optional int sharemode = 2;
       optional int brl_type = 3;
       optional int64 brl_offset = 4;
       optional int64 brl_length = 5;
}