  __u32 get_global_seq(__u32 old=0) {
    ceph_spin_lock(&global_seq_lock);
    if (old > global_seq)
      global_seq = old;
    __u32 ret = ++global_seq;
    ceph_spin_unlock(&global_seq_lock);
    return ret;
  }
  __u32 get_global_seq(__u32 old=0) {
    ceph_spin_lock(&global_seq_lock);
    if (old > global_seq)
      global_seq = old;
    __u32 ret = ++global_seq;
    ceph_spin_unlock(&global_seq_lock);
    return ret;
  }