[systemd-devel] Failure to remount / ro (Was: Re: [PATCH 2/4] Adding unmount functions to be used in shutdown)

[Michael Biebl]

Together with fidencio I tracked down the bug which caused / *not* to
be remounted ro on shutdown.

The relevant code is in src/umount.c

2010/10/7  <fidencio at profusion.mobi>:
> +int umount_all(void) {
> +        int r;
> +        LIST_HEAD(MountPoint, mp_list_head);
> +
> +        LIST_HEAD_INIT(MountPoint, mp_list_head);
> +
> +        r = mount_points_list_get(&mp_list_head);
> +        if (r < 0)
> +                goto end;
> +
> +        r = mount_points_list_umount(&mp_list_head);
> +        if (r <= 0)
> +                goto end;

r is the number of mount points which failed to be unmounted.
We always skip / in mount_points_list_umount though,
I.e. if there is no failed unmount attempt, we will never try to remount / ro.

Maybe we should just call mount_points_list_remount_read_only unconditionally.
or increment the failed counter in mount_points_list_umount if we skip "/"



+static int mount_points_list_umount(MountPoint **mount_point_list_head) {
+        MountPoint *mp, *mp_next;
+        int failed = 0;
+
+        LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mount_point_list_head) {
+                if (streq(mp->path, "/"))
+                        continue;
                          ^ add failed++ to make sure / is remounted-ro?

-- 
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?