public static void report(List<File> failedFiles) {
    if (failedFiles.isEmpty()) {
      logger.info("Check finished. There is no damaged file");
    } else {
      logger.error("There are {} failed files. They are {}", failedFiles.size(), failedFiles);
    }
  }
check the root wal dir and find the damaged files

@return a list of damaged files.
@throws WALException if the root wal dir does not exist.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/tools/WalChecker.java