code: public AlluxioURI reverseResolve(AlluxioURI ufsUri) {
      AlluxioURI returnVal = null;
      for (Map.Entry<String, MountInfo> mountInfoEntry : getMountTable().entrySet()) {
        try {
          if (mountInfoEntry.getValue().getUfsUri().isAncestorOf(ufsUri)) {
            returnVal = reverseResolve(mountInfoEntry.getValue().getAlluxioUri(),
                mountInfoEntry.getValue().getUfsUri(), ufsUri);
          }
        } catch (InvalidPathException | RuntimeException e) {
          LOG.info(Throwables.getStackTraceAsString(e));
          // expected when ufsUri does not belong to this particular mountPoint
        }
        if (returnVal != null) {
          return returnVal;
        }
      }
      return null;
    }
docs: REsolves the given Ufs path. If the given UFs path is mounted in Alluxio space, it returns
  the associated Alluxio path.
  @param ufsUri an Ufs path URI
  @return an Alluxio path URI