func: static int qcow2_is_allocated(BlockDriverState *bs, int64_t sector_num,
  
                                int nb_sectors, int *pnum)
  
  {
  
      uint64_t cluster_offset;
  
      int ret;
  
  
  
      *pnum = nb_sectors;
  
      /* FIXME We can get errors here, but the bdrv_is_allocated interface can't
  
       * pass them on today */
  
      ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
  
      if (ret < 0) {
  
          *pnum = 0;
  
      }
  
  
  
      return (cluster_offset != 0);
  
  }
  