1 struct dentry *
  2 d_lookup(struct dentry * parent,
  3          struct qstr * name)
  4 {
  5   struct dentry * dentry = NULL;
  6   unsigned long seq;
  7 
  8   do {
  9     seq = read_seqbegin(&rename_lock);
 10     dentry = __d_lookup(parent, name);
 11     if (dentry)
 12       break;
 13   } while (read_seqretry(&rename_lock, seq));
 14   return dentry;
 15 }