func: static int qcow2_co_flush(BlockDriverState *bs)
  
  {
  
      BDRVQcowState *s = bs->opaque;
  
      int ret;
  
  
  
      qemu_co_mutex_lock(&s->lock);
  
      ret = qcow2_cache_flush(bs, s->l2_table_cache);
  
      if (ret < 0) {
  
  
          return ret;
  
      }
  
  
  
      ret = qcow2_cache_flush(bs, s->refcount_block_cache);
  
      if (ret < 0) {
  
  
          return ret;
  
      }
  
  
  
  
      return bdrv_co_flush(bs->file);
  
  }