// save the root
saveINode2Image(rootDir, out, false, referenceMap, counter);
// save the rest of the nodes
saveImage(rootDir, out, true, false, counter);
prog.endStep(Phase.SAVING_CHECKPOINT, step);
// Now that the step is finished, set counter equal to total to adjust
// for possible under-counting due to reference inodes.
prog.setCount(Phase.SAVING_CHECKPOINT, step, numINodes);
// save files under construction
// TODO: for HDFS-5428, since we cannot break the compatibility of