// We allow rollback to a state, which is either consistent with
// the namespace state or can be further upgraded to it.
if (!(prevInfo.getLayoutVersion() >= FSConstants.LAYOUT_VERSION
&& prevInfo.getCTime() <= nsInfo.getCTime())) // cannot rollback
throw new InconsistentFSStateException(prevSD.getRoot(),
"Cannot rollback to a newer state.\nDatanode previous state: LV = "
+ prevInfo.getLayoutVersion() + " CTime = " + prevInfo.getCTime()
+ " is newer than the namespace state: LV = "
+ nsInfo.getLayoutVersion() + " CTime = " + nsInfo.getCTime());
LOG.info("Rolling back storage directory " + sd.getRoot()