int vfs_whiteout(struct inode *dir, struct dentry *dentry)
{
	int error = may_create(dir, dentry);
	if (error)
		return error;

	if (!dir->i_op->mknod)
		return -EPERM;

	return dir->i_op->mknod(dir, dentry,
				S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV);
}