void cleanupDaughterRegion(final RegionInfo regionInfo) throws IOException {
    Path regionDir = new Path(this.tableDir, regionInfo.getEncodedName());
    if (this.fs.exists(regionDir) && !deleteDir(regionDir)) {
      throw new IOException("Failed delete of " + regionDir);
    }
  }
Remove daughter region
@param regionInfo daughter {@link RegionInfo}
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionFileSystem.java