code: INodeDirectory addToParent( byte[] src,
                                INodeDirectory parentINode,
                                INode newNode,
                                boolean propagateModTime,
                                int childIndex) {
      // NOTE: This does not update space counts for parents
      // add new node to the parent
      INodeDirectory newParent = null;
      writeLock();
      try {
        try {
          newParent = rootDir.addToParent(src, newNode, parentINode,
                                              false, propagateModTime, childIndex);
          cacheName(newNode);
        } catch (FileNotFoundException e) {
          return null;
        }
        if(newParent == null)
          return null;
        if(!newNode.isDirectory()) {
          // Add block->file mapping
          INodeFile newF = (INodeFile)newNode;
          BlockInfo[] blocks = newF.getBlocks();
          for (int i = 0; i < blocks.length; i++) {
            newF.setBlock(i, getFSNamesystem().blocksMap.addINodeForLoading(blocks[i], newF));
          }
        }
      } finally {
        writeUnlock();
      }
      return newParent;
    }
docs: Add node to parent node when loading the image.