code: public void logSetQuota(String src, long nsQuota, long dsQuota) {
      SetQuotaOp op = SetQuotaOp.getInstance();
      op.set(src, nsQuota, dsQuota);
      logEdit(op);
    }
docs: Add set namespace quota record to edit log
  
  @param src the string representation of the path to a directory
  @param quota the directory size limit