cgroup: Implicit unit_invalidate_cgroup_members_masks

Merge members mask invalidation into
unit_add_siblings_to_cgroup_realize_queue, this way unit_realize_cgroup
needn't be called with members mask invalidation.

We have to retain the members mask invalidation in unit_load -- although
active units would have cgroups (re)realized (unit_load queues for
realization), the realization would happen with potentially stale mask.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 84512963a4..c159310748 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -2319,6 +2319,8 @@ void unit_add_siblings_to_cgroup_realize_queue(Unit *u) {
 
         /* This adds the path from the specified unit to root slice to the queue and siblings at each level.
          * The unit itself is excluded (assuming it's handled separately).
+         * The function must invalidate cgroup_members_mask of all ancestors in order to calculate up to date
+         * masks.
          *
          * Propagation of realization "side-ways" (i.e. towards siblings) is relevant on cgroup-v1 where
          * scheduling becomes very weird if two units that own processes reside in the same slice, but one is
@@ -2333,6 +2335,9 @@ void unit_add_siblings_to_cgroup_realize_queue(Unit *u) {
                 Unit *m;
                 void *v;
 
+                /* Children of slice likely changed when we're called */
+                slice->cgroup_members_mask_valid = false;
+
                 HASHMAP_FOREACH_KEY(v, m, slice->dependencies[UNIT_BEFORE], i) {
                         /* Skip units that have a dependency on the slice but aren't actually in it. */
                         if (UNIT_DEREF(m->slice) != slice)