core: find the closest parent slice that has a specfic cgroup controller enabled when enabling/disabling cgroup controllers for units

2 files changed, 15 insertions, 4 deletions

diff --git a/src/shared/cgroup-util.c b/src/shared/cgroup-util.c
index 9692a07f56..1aa81c2cd1 100644
--- a/src/shared/cgroup-util.c
+++ b/src/shared/cgroup-util.c
@@ -1668,7 +1668,7 @@ int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path,
         return r;
 }
 
-int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to) {
+int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to, cg_migrate_callback_t to_callback, void *userdata) {
         CGroupControllerMask bit = 1;
         const char *n;
         int r;
@@ -1680,8 +1680,17 @@ int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, cons
         }
 
         NULSTR_FOREACH(n, mask_names) {
-                if (supported & bit)
-                        cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, n, to, false, false);
+                if (supported & bit) {
+                        const char *p = NULL;
+
+                        if (to_callback)
+                                p = to_callback(bit, userdata);
+
+                        if (!p)
+                                p = to;
+
+                        cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, n, p, false, false);
+                }
 
                 bit <<= 1;
         }
diff --git a/src/shared/cgroup-util.h b/src/shared/cgroup-util.h
index 743d902e2d..aca4e44c46 100644
--- a/src/shared/cgroup-util.h
+++ b/src/shared/cgroup-util.h
@@ -122,10 +122,12 @@ bool cg_controller_is_valid(const char *p, bool allow_named);
 
 int cg_slice_to_path(const char *unit, char **ret);
 
+typedef const char* (*cg_migrate_callback_t)(CGroupControllerMask mask, void *userdata);
+
 int cg_create_everywhere(CGroupControllerMask supported, CGroupControllerMask mask, const char *path);
 int cg_attach_everywhere(CGroupControllerMask supported, const char *path, pid_t pid);
 int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path, Set* pids);
-int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to);
+int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to, cg_migrate_callback_t callback, void *userdata);
 int cg_trim_everywhere(CGroupControllerMask supported, const char *path, bool delete_root);
 
 CGroupControllerMask cg_mask_supported(void);