/**
* save all the snapshot diff to fsimage
*/
public void serializeSnapshotDiffSection(OutputStream out)
throws IOException {
INodeMap inodesMap = fsn.getFSDirectory().getINodeMap();
final List<INodeReference> refList = parent.getSaverContext()
.getRefList();
int i = 0;
Iterator<INodeWithAdditionalFields> iter = inodesMap.getMapIterator();
while (iter.hasNext()) {
INodeWithAdditionalFields inode = iter.next();
if (inode.isFile()) {
serializeFileDiffList(inode.asFile(), out);
} else if (inode.isDirectory()) {