On Mon, Jul 11, 2022 at 11:37:46AM +0800, Ian Kent wrote:
> +static int do_mount_in_use_check(struct mount *mnt, int cnt)
> +{
> + struct mount *topper;
> +
> + /* Is there exactly one mount on the child that covers
> + * it completely?
> + */
> + topper = find_topper(mnt);
> + if (topper) {
> + int topper_cnt = topper->mnt_mounts_cnt + 1;
> +
> + /* Open file or pwd within singular mount? */
> + if (do_refcount_check(topper, topper_cnt))
> + return 1;
Whatever the hell for? umount(2) will be able to slide the
underlying mount from under the topper, whatever the
refcount of topper might have been.
