private void closeMetaTableRegions(final boolean abort) {
    HRegion meta = null;
    this.onlineRegionsLock.writeLock().lock();
    try {
      for (Map.Entry<String, HRegion> e : onlineRegions.entrySet()) {
        RegionInfo hri = e.getValue().getRegionInfo();
        if (hri.isMetaRegion()) {
          meta = e.getValue();
        }
        if (meta != null) {
          break;
        }
      }
    } finally {
      this.onlineRegionsLock.writeLock().unlock();
    }
    if (meta != null) {
      closeRegionIgnoreErrors(meta.getRegionInfo(), abort);
    }
  }
Close meta region if we carry it
@param abort Whether we're running an abort.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java