core: make unit_has_mask_realized() consider controller enable state

unit_has_mask_realized() determines whether the specified unit has its cgroups
set up properly given the desired target_mask; however, on the unified
hierarchy, controllers need to be enabled explicitly for children and the mask
of enabled controllers can deviate from target_mask.  Only considering
target_mask in unit_has_mask_realized() can lead to false positives and
skipping enabling the requested controllers.

This patch adds unit->cgroup_enabled_mask to track which controllers are
enabled and updates unit_has_mask_realized() to also consider enable_mask.

Signed-off-by: Tejun Heo <htejun@fb.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/core/unit.h b/src/core/unit.h
index 5909652976..78f950c051 100644
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -186,6 +186,7 @@ struct Unit {
         /* Counterparts in the cgroup filesystem */
         char *cgroup_path;
         CGroupMask cgroup_realized_mask;
+        CGroupMask cgroup_enabled_mask;
         CGroupMask cgroup_subtree_mask;
         CGroupMask cgroup_members_mask;
         int cgroup_inotify_wd;