public static BackupInfo loadBackupInfo(Path backupRootPath, String backupId, FileSystem fs)
    throws IOException {
    Path backupPath = new Path(backupRootPath, backupId);

    RemoteIterator<LocatedFileStatus> it = fs.listFiles(backupPath, true);
    while (it.hasNext()) {
      LocatedFileStatus lfs = it.next();
      if (lfs.getPath().getName().equals(BackupManifest.MANIFEST_FILE_NAME)) {
        // Load BackupManifest
        BackupManifest manifest = new BackupManifest(fs, lfs.getPath().getParent());
        BackupInfo info = manifest.toBackupInfo();
        return info;
      }
    }
    return null;
  }
Given the backup root dir and the backup id, return the log file location for an incremental
backup.
@param backupRootDir backup root directory
@param backupId      backup id
@return logBackupDir: ".../user/biadmin/backup1/WALs/backup_1396650096738"
hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/util/BackupUtils.java