code: func lazyChown(p string, uid, gid int, stat *system.StatT) error {
  	if stat == nil {
  		var err error
  		stat, err = system.Stat(p)
  		if err != nil {
  			return err
  		}
  	}
  	if stat.UID() == uint32(uid) && stat.GID() == uint32(gid) {
  		return nil
  	}
  	return os.Chown(p, uid, gid)
  }
docs: // lazyChown performs a chown only if the uid/gid don't match what's requested
  // Normally a Chown is a no-op if uid/gid match, but in some cases this can still cause an error, e.g. if the
  // dir is on an NFS share, so don't call chown unless we absolutely must.