	__releases(dentry->d_lock)
{
	struct inode *inode = dentry->d_inode;
	struct dentry *parent = NULL;

	if (inode && unlikely(!spin_trylock(&inode->i_lock)))
		goto failed;

	if (!IS_ROOT(dentry)) {
		parent = dentry->d_parent;
		if (unlikely(!spin_trylock(&parent->d_lock))) {
			if (inode)
				spin_unlock(&inode->i_lock);
			goto failed;
		}
	}

	__dentry_kill(dentry);
	return parent;

failed:
	spin_unlock(&dentry->d_lock);
	cpu_relax();
	return dentry; /* try again with same dentry */
}
	__releases(dentry->d_lock)
{
	struct inode *inode = dentry->d_inode;
	struct dentry *parent = NULL;

	if (inode && unlikely(!spin_trylock(&inode->i_lock)))
		goto failed;

	if (!IS_ROOT(dentry)) {
		parent = dentry->d_parent;
		if (unlikely(!spin_trylock(&parent->d_lock))) {
			if (inode)
				spin_unlock(&inode->i_lock);
			goto failed;
		}
	}

	__dentry_kill(dentry);
	return parent;

failed:
	spin_unlock(&dentry->d_lock);
	cpu_relax();
	return dentry;  
}