diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index 6948ed3931..48623fb235 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -594,7 +594,7 @@ static int join_path_unified(const char *path, const char *suffix, char **fs) {
 }
 
 int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) {
-        int unified, r;
+        int r;
 
         assert(fs);
 
@@ -623,11 +623,7 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
         if (!cg_controller_is_valid(controller))
                 return -EINVAL;
 
-        unified = cg_all_unified();
-        if (unified < 0)
-                return unified;
-
-        if (unified > 0)
+        if (cg_all_unified())
                 r = join_path_unified(path, suffix, fs);
         else
                 r = join_path_legacy(controller, path, suffix, fs);
@@ -639,7 +635,6 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
 }
 
 static int controller_is_accessible(const char *controller) {
-        int unified;
 
         assert(controller);
 
@@ -651,10 +646,7 @@ static int controller_is_accessible(const char *controller) {
         if (!cg_controller_is_valid(controller))
                 return -EINVAL;
 
-        unified = cg_all_unified();
-        if (unified < 0)
-                return unified;
-        if (unified > 0) {
+        if (cg_all_unified()) {
                 /* We don't support named hierarchies if we are using
                  * the unified hierarchy. */
 
@@ -851,7 +843,7 @@ int cg_set_task_access(
                 gid_t gid) {
 
         _cleanup_free_ char *fs = NULL, *procs = NULL;
-        int r, unified;
+        int r;
 
         assert(path);
 
@@ -869,10 +861,7 @@ int cg_set_task_access(
         if (r < 0)
                 return r;
 
-        unified = cg_unified(controller);
-        if (unified < 0)
-                return unified;
-        if (unified)
+        if (cg_unified(controller))
                 return 0;
 
         /* Compatibility, Always keep values for "tasks" in sync with
@@ -925,7 +914,7 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
         char line[LINE_MAX];
         const char *fs;
         size_t cs = 0;
-        int unified;
+        bool unified;
 
         assert(path);
         assert(pid >= 0);
@@ -937,9 +926,7 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
                 controller = SYSTEMD_CGROUP_CONTROLLER;
 
         unified = cg_unified(controller);
-        if (unified < 0)
-                return unified;
-        if (unified == 0)
+        if (!unified)
                 cs = strlen(controller);
 
         fs = procfs_file_alloca(pid, "cgroup");
@@ -1001,14 +988,11 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
 int cg_install_release_agent(const char *controller, const char *agent) {
         _cleanup_free_ char *fs = NULL, *contents = NULL;
         const char *sc;
-        int r, unified;
+        int r;
 
         assert(agent);
 
-        unified = cg_unified(controller);
-        if (unified < 0)
-                return unified;
-        if (unified) /* doesn't apply to unified hierarchy */
+        if (cg_unified(controller)) /* doesn't apply to unified hierarchy */
                 return -EOPNOTSUPP;
 
         r = cg_get_path(controller, NULL, "release_agent", &fs);
@@ -1054,12 +1038,9 @@ int cg_install_release_agent(const char *controller, const char *agent) {
 
 int cg_uninstall_release_agent(const char *controller) {
         _cleanup_free_ char *fs = NULL;
-        int r, unified;
+        int r;
 
-        unified = cg_unified(controller);
-        if (unified < 0)
-                return unified;
-        if (unified) /* Doesn't apply to unified hierarchy */
+        if (cg_unified(controller)) /* Doesn't apply to unified hierarchy */
                 return -EOPNOTSUPP;
 
         r = cg_get_path(controller, NULL, "notify_on_release", &fs);
@@ -1104,7 +1085,7 @@ int cg_is_empty(const char *controller, const char *path) {
 }
 
 int cg_is_empty_recursive(const char *controller, const char *path) {
-        int unified, r;
+        int r;
 
         assert(path);
 
@@ -1112,11 +1093,7 @@ int cg_is_empty_recursive(const char *controller, const char *path) {
         if (controller && (isempty(path) || path_equal(path, "/")))
                 return false;
 
-        unified = cg_unified(controller);
-        if (unified < 0)
-                return unified;
-
-        if (unified > 0) {
+        if (cg_unified(controller)) {
                 _cleanup_free_ char *t = NULL;
 
                 /* On the unified hierarchy we can check empty state
@@ -1986,7 +1963,7 @@ int cg_get_keyed_attribute(const char *controller, const char *path, const char
 
 int cg_create_everywhere(CGroupMask supported, CGroupMask mask, const char *path) {
         CGroupController c;
-        int r, unified;
+        int r;
 
         /* This one will create a cgroup in our private tree, but also
          * duplicate it in the trees specified in mask, and remove it
@@ -1998,10 +1975,7 @@ int cg_create_everywhere(CGroupMask supported, CGroupMask mask, const char *path
                 return r;
 
         /* If we are in the unified hierarchy, we are done now */
-        unified = cg_all_unified();
-        if (unified < 0)
-                return unified;
-        if (unified > 0)
+        if (cg_all_unified())
                 return 0;
 
         /* Otherwise, do the same in the other hierarchies */
@@ -2022,16 +1996,13 @@ int cg_create_everywhere(CGroupMask supported, CGroupMask mask, const char *path
 
 int cg_attach_everywhere(CGroupMask supported, const char *path, pid_t pid, cg_migrate_callback_t path_callback, void *userdata) {
         CGroupController c;
-        int r, unified;
+        int r;
 
         r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, path, pid);
         if (r < 0)
                 return r;
 
-        unified = cg_all_unified();
-        if (unified < 0)
-                return unified;
-        if (unified > 0)
+        if (cg_all_unified())
                 return 0;
 
         for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
@@ -2072,7 +2043,7 @@ int cg_attach_many_everywhere(CGroupMask supported, const char *path, Set* pids,
 
 int cg_migrate_everywhere(CGroupMask supported, const char *from, const char *to, cg_migrate_callback_t to_callback, void *userdata) {
         CGroupController c;
-        int r = 0, unified;
+        int r = 0;
 
         if (!path_equal(from, to))  {
                 r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, from, SYSTEMD_CGROUP_CONTROLLER, to, CGROUP_REMOVE);
@@ -2080,10 +2051,7 @@ int cg_migrate_everywhere(CGroupMask supported, const char *from, const char *to
                         return r;
         }
 
-        unified = cg_all_unified();
-        if (unified < 0)
-                return unified;
-        if (unified > 0)
+        if (cg_all_unified())
                 return r;
 
         for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
@@ -2107,16 +2075,13 @@ int cg_migrate_everywhere(CGroupMask supported, const char *from, const char *to
 
 int cg_trim_everywhere(CGroupMask supported, const char *path, bool delete_root) {
         CGroupController c;
-        int r, unified;
+        int r;
 
         r = cg_trim(SYSTEMD_CGROUP_CONTROLLER, path, delete_root);
         if (r < 0)
                 return r;
 
-        unified = cg_all_unified();
-        if (unified < 0)
-                return unified;
-        if (unified > 0)
+        if (cg_all_unified())
                 return r;
 
         for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
@@ -2133,16 +2098,13 @@ int cg_trim_everywhere(CGroupMask supported, const char *path, bool delete_root)
 
 int cg_mask_supported(CGroupMask *ret) {
         CGroupMask mask = 0;
-        int r, unified;
+        int r;
 
         /* Determines the mask of supported cgroup controllers. Only
          * includes controllers we can make sense of and that are
          * actually accessible. */
 
-        unified = cg_all_unified();
-        if (unified < 0)
-                return unified;
-        if (unified > 0) {
+        if (cg_all_unified()) {
                 _cleanup_free_ char *root = NULL, *controllers = NULL, *path = NULL;
                 const char *c;
 
@@ -2291,13 +2253,9 @@ static int cg_update_unified(void) {
         return 0;
 }
 
-int cg_unified(const char *controller) {
+bool cg_unified(const char *controller) {
 
-        int r;
-
-        r = cg_update_unified();
-        if (r < 0)
-                return r;
+        assert(cg_update_unified() >= 0);
 
         if (streq_ptr(controller, SYSTEMD_CGROUP_CONTROLLER))
                 return unified_cache >= CGROUP_UNIFIED_SYSTEMD;
@@ -2305,29 +2263,28 @@ int cg_unified(const char *controller) {
                 return unified_cache >= CGROUP_UNIFIED_ALL;
 }
 
-int cg_all_unified(void) {
+bool cg_all_unified(void) {
 
         return cg_unified(NULL);
 }
 
-void cg_unified_flush(void) {
+int cg_unified_flush(void) {
         unified_cache = CGROUP_UNIFIED_UNKNOWN;
+
+        return cg_update_unified();
 }
 
 int cg_enable_everywhere(CGroupMask supported, CGroupMask mask, const char *p) {
         _cleanup_free_ char *fs = NULL;
         CGroupController c;
-        int r, unified;
+        int r;
 
         assert(p);
 
         if (supported == 0)
                 return 0;
 
-        unified = cg_all_unified();
-        if (unified < 0)
-                return unified;
-        if (!unified) /* on the legacy hiearchy there's no joining of controllers defined */
+        if (!cg_all_unified()) /* on the legacy hiearchy there's no joining of controllers defined */
                 return 0;
 
         r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, p, "cgroup.subtree_control", &fs);
@@ -2359,14 +2316,13 @@ int cg_enable_everywhere(CGroupMask supported, CGroupMask mask, const char *p) {
 
 bool cg_is_unified_wanted(void) {
         static thread_local int wanted = -1;
-        int r, unified;
+        int r;
         bool b;
 
         /* If the hierarchy is already mounted, then follow whatever
          * was chosen for it. */
-        unified = cg_all_unified();
-        if (unified >= 0)
-                return unified;
+        if (cg_unified_flush() >= 0)
+                return cg_all_unified();
 
         /* Otherwise, let's see what the kernel command line has to
          * say. Since checking that is expensive, let's cache the
@@ -2387,7 +2343,7 @@ bool cg_is_legacy_wanted(void) {
 
 bool cg_is_unified_systemd_controller_wanted(void) {
         static thread_local int wanted = -1;
-        int r, unified;
+        int r;
         bool b;
 
         /* If the unified hierarchy is requested in full, no need to
@@ -2397,9 +2353,8 @@ bool cg_is_unified_systemd_controller_wanted(void) {
 
         /* If the hierarchy is already mounted, then follow whatever
          * was chosen for it. */
-        unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
-        if (unified >= 0)
-                return unified;
+        if (cg_unified_flush() >= 0)
+                return cg_unified(SYSTEMD_CGROUP_CONTROLLER);
 
         /* Otherwise, let's see what the kernel command line has to
          * say. Since checking that is expensive, let's cache the
diff --git a/src/basic/cgroup-util.h b/src/basic/cgroup-util.h
index 0aa27c4cd7..09dcc2b38e 100644
--- a/src/basic/cgroup-util.h
+++ b/src/basic/cgroup-util.h
@@ -240,9 +240,9 @@ int cg_kernel_controllers(Set *controllers);
 
 bool cg_ns_supported(void);
 
-int cg_all_unified(void);
-int cg_unified(const char *controller);
-void cg_unified_flush(void);
+bool cg_all_unified(void);
+bool cg_unified(const char *controller);
+int cg_unified_flush(void);
 
 bool cg_is_unified_wanted(void);
 bool cg_is_legacy_wanted(void);
diff --git a/src/cgls/cgls.c b/src/cgls/cgls.c
index 5574c14555..40db82f9ae 100644
--- a/src/cgls/cgls.c
+++ b/src/cgls/cgls.c
@@ -158,7 +158,7 @@ static int parse_argv(int argc, char *argv[]) {
 
 static void show_cg_info(const char *controller, const char *path) {
 
-        if (cg_all_unified() <= 0 && controller && !streq(controller, SYSTEMD_CGROUP_CONTROLLER))
+        if (!cg_all_unified() && controller && !streq(controller, SYSTEMD_CGROUP_CONTROLLER))
                 printf("Controller %s; ", controller);
 
         printf("Control group %s:\n", isempty(path) ? "/" : path);
diff --git a/src/cgtop/cgtop.c b/src/cgtop/cgtop.c
index 50ac6a58b0..45c050c9c3 100644
--- a/src/cgtop/cgtop.c
+++ b/src/cgtop/cgtop.c
@@ -214,7 +214,7 @@ static int process(
                 uint64_t new_usage;
                 nsec_t timestamp;
 
-                if (cg_all_unified() > 0) {
+                if (cg_all_unified()) {
                         const char *keys[] = { "usage_usec", NULL };
                         _cleanup_free_ char *val = NULL;
 
@@ -274,7 +274,7 @@ static int process(
         } else if (streq(controller, "memory")) {
                 _cleanup_free_ char *p = NULL, *v = NULL;
 
-                if (cg_all_unified() <= 0)
+                if (!cg_all_unified())
                         r = cg_get_path(controller, path, "memory.usage_in_bytes", &p);
                 else
                         r = cg_get_path(controller, path, "memory.current", &p);
@@ -294,15 +294,14 @@ static int process(
                 if (g->memory > 0)
                         g->memory_valid = true;
 
-        } else if ((streq(controller, "io") && cg_all_unified() > 0) ||
-                   (streq(controller, "blkio") && cg_all_unified() <= 0)) {
+        } else if ((streq(controller, "io") && cg_all_unified()) ||
+                   (streq(controller, "blkio") && !cg_all_unified())) {
                 _cleanup_fclose_ FILE *f = NULL;
                 _cleanup_free_ char *p = NULL;
-                bool unified = cg_all_unified() > 0;
                 uint64_t wr = 0, rd = 0;
                 nsec_t timestamp;
 
-                r = cg_get_path(controller, path, unified ? "io.stat" : "blkio.io_service_bytes", &p);
+                r = cg_get_path(controller, path, cg_all_unified() ? "io.stat" : "blkio.io_service_bytes", &p);
                 if (r < 0)
                         return r;
 
@@ -325,7 +324,7 @@ static int process(
                         l += strcspn(l, WHITESPACE);
                         l += strspn(l, WHITESPACE);
 
-                        if (unified) {
+                        if (cg_all_unified()) {
                                 while (!isempty(l)) {
                                         if (sscanf(l, "rbytes=%" SCNu64, &k))
                                                 rd += k;
diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 5789e2aa82..17e0857729 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -678,7 +678,7 @@ static void cgroup_context_apply(Unit *u, CGroupMask mask, ManagerState state) {
                 bool has_weight = cgroup_context_has_cpu_weight(c);
                 bool has_shares = cgroup_context_has_cpu_shares(c);
 
-                if (cg_all_unified() > 0) {
+                if (cg_all_unified()) {
                         uint64_t weight;
 
                         if (has_weight)
@@ -858,7 +858,7 @@ static void cgroup_context_apply(Unit *u, CGroupMask mask, ManagerState state) {
         }
 
         if ((mask & CGROUP_MASK_MEMORY) && !is_root) {
-                if (cg_all_unified() > 0) {
+                if (cg_all_unified()) {
                         uint64_t max;
                         uint64_t swap_max = CGROUP_LIMIT_MAX;
 
@@ -1033,7 +1033,7 @@ CGroupMask unit_get_own_mask(Unit *u) {
                 e = unit_get_exec_context(u);
                 if (!e ||
                     exec_context_maintains_privileges(e) ||
-                    cg_all_unified() > 0)
+                    cg_all_unified())
                         return _CGROUP_MASK_ALL;
         }
 
@@ -1260,10 +1260,7 @@ int unit_watch_cgroup(Unit *u) {
                 return 0;
 
         /* Only applies to the unified hierarchy */
-        r = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
-        if (r < 0)
-                return log_unit_error_errno(u, r, "Failed detect whether the unified hierarchy is used: %m");
-        if (r == 0)
+        if (!cg_unified(SYSTEMD_CGROUP_CONTROLLER))
                 return 0;
 
         /* Don't watch the root slice, it's pointless. */
@@ -1683,7 +1680,7 @@ int unit_watch_all_pids(Unit *u) {
         if (!u->cgroup_path)
                 return -ENOENT;
 
-        if (cg_unified(SYSTEMD_CGROUP_CONTROLLER) > 0) /* On unified we can use proper notifications */
+        if (cg_unified(SYSTEMD_CGROUP_CONTROLLER)) /* On unified we can use proper notifications */
                 return 0;
 
         return unit_watch_pids_in_path(u, u->cgroup_path);
@@ -1756,7 +1753,7 @@ static int on_cgroup_inotify_event(sd_event_source *s, int fd, uint32_t revents,
 int manager_setup_cgroup(Manager *m) {
         _cleanup_free_ char *path = NULL;
         CGroupController c;
-        int r, all_unified, systemd_unified;
+        int r;
         char *e;
 
         assert(m);
@@ -1793,16 +1790,13 @@ int manager_setup_cgroup(Manager *m) {
         if (r < 0)
                 return log_error_errno(r, "Cannot find cgroup mount point: %m");
 
-        all_unified = cg_all_unified();
-        systemd_unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
+        r = cg_unified_flush();
+        if (r < 0)
+                return log_error_errno(r, "Couldn't determine if we are running in the unified hierarchy: %m");
 
-        if (all_unified < 0 || systemd_unified < 0)
-                return log_error_errno(all_unified < 0 ? all_unified : systemd_unified,
-                                       "Couldn't determine if we are running in the unified hierarchy: %m");
-
-        if (all_unified > 0)
+        if (cg_all_unified())
                 log_debug("Unified cgroup hierarchy is located at %s.", path);
-        else if (systemd_unified > 0)
+        else if (cg_unified(SYSTEMD_CGROUP_CONTROLLER))
                 log_debug("Unified cgroup hierarchy is located at %s. Controllers are on legacy hierarchies.", path);
         else
                 log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER ". File system hierarchy is at %s.", path);
@@ -1811,7 +1805,7 @@ int manager_setup_cgroup(Manager *m) {
                 const char *scope_path;
 
                 /* 3. Install agent */
-                if (systemd_unified) {
+                if (cg_unified(SYSTEMD_CGROUP_CONTROLLER)) {
 
                         /* In the unified hierarchy we can get
                          * cgroup empty notifications via inotify. */
@@ -1871,7 +1865,7 @@ int manager_setup_cgroup(Manager *m) {
                         return log_error_errno(errno, "Failed to open pin file: %m");
 
                 /* 6.  Always enable hierarchical support if it exists... */
-                if (!all_unified)
+                if (!cg_all_unified())
                         (void) cg_set_attribute("memory", "/", "memory.use_hierarchy", "1");
         }
 
@@ -1997,7 +1991,7 @@ int unit_get_memory_current(Unit *u, uint64_t *ret) {
         if ((u->cgroup_realized_mask & CGROUP_MASK_MEMORY) == 0)
                 return -ENODATA;
 
-        if (cg_all_unified() <= 0)
+        if (!cg_all_unified())
                 r = cg_get_attribute("memory", u->cgroup_path, "memory.usage_in_bytes", &v);
         else
                 r = cg_get_attribute("memory", u->cgroup_path, "memory.current", &v);
@@ -2042,7 +2036,7 @@ static int unit_get_cpu_usage_raw(Unit *u, nsec_t *ret) {
         if (!u->cgroup_path)
                 return -ENODATA;
 
-        if (cg_all_unified() > 0) {
+        if (cg_all_unified()) {
                 const char *keys[] = { "usage_usec", NULL };
                 _cleanup_free_ char *val = NULL;
                 uint64_t us;
diff --git a/src/core/manager.c b/src/core/manager.c
index b509adfc64..b2cd352a0c 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -775,7 +775,7 @@ static int manager_setup_cgroups_agent(Manager *m) {
         if (!MANAGER_IS_SYSTEM(m))
                 return 0;
 
-        if (cg_unified(SYSTEMD_CGROUP_CONTROLLER) > 0) /* We don't need this anymore on the unified hierarchy */
+        if (cg_unified(SYSTEMD_CGROUP_CONTROLLER)) /* We don't need this anymore on the unified hierarchy */
                 return 0;
 
         if (m->cgroups_agent_fd < 0) {
diff --git a/src/core/scope.c b/src/core/scope.c
index 9540fb67d9..5e068a76d1 100644
--- a/src/core/scope.c
+++ b/src/core/scope.c
@@ -475,7 +475,7 @@ static void scope_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 
         /* If the PID set is empty now, then let's finish this off
            (On unified we use proper notifications) */
-        if (cg_unified(SYSTEMD_CGROUP_CONTROLLER) <= 0 && set_isempty(u->pids))
+        if (!cg_unified(SYSTEMD_CGROUP_CONTROLLER) && set_isempty(u->pids))
                 scope_notify_cgroup_empty_event(u);
 }
 
diff --git a/src/core/service.c b/src/core/service.c
index 54074ff7bc..0c2eb18f38 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -2938,7 +2938,7 @@ static void service_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 
         /* If the PID set is empty now, then let's finish this off
            (On unified we use proper notifications) */
-        if (cg_unified(SYSTEMD_CGROUP_CONTROLLER) <= 0 && set_isempty(u->pids))
+        if (!cg_unified(SYSTEMD_CGROUP_CONTROLLER) && set_isempty(u->pids))
                 service_notify_cgroup_empty_event(u);
 }
 
diff --git a/src/core/unit.c b/src/core/unit.c
index bb05d2abfb..685df6f00d 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -3897,8 +3897,8 @@ int unit_kill_context(
                          * there we get proper events. Hence rely on
                          * them.*/
 
-                        if  (cg_unified(SYSTEMD_CGROUP_CONTROLLER) > 0 ||
-                             (detect_container() == 0 && !unit_cgroup_delegate(u)))
+                        if (cg_unified(SYSTEMD_CGROUP_CONTROLLER) ||
+                            (detect_container() == 0 && !unit_cgroup_delegate(u)))
                                 wait_for_exit = true;
 
                         if (send_sighup) {
diff --git a/src/libsystemd/sd-bus/test-bus-creds.c b/src/libsystemd/sd-bus/test-bus-creds.c
index 6fdcfa4128..64bd76a576 100644
--- a/src/libsystemd/sd-bus/test-bus-creds.c
+++ b/src/libsystemd/sd-bus/test-bus-creds.c
@@ -31,7 +31,7 @@ int main(int argc, char *argv[]) {
         log_parse_environment();
         log_open();
 
-        if (cg_all_unified() == -ENOMEDIUM) {
+        if (cg_unified_flush() == -ENOMEDIUM) {
                 log_info("Skipping test: /sys/fs/cgroup/ not available");
                 return EXIT_TEST_SKIP;
         }
diff --git a/src/nspawn/nspawn-cgroup.c b/src/nspawn/nspawn-cgroup.c
index 5274767b96..4678a7e349 100644
--- a/src/nspawn/nspawn-cgroup.c
+++ b/src/nspawn/nspawn-cgroup.c
@@ -78,13 +78,9 @@ int sync_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t arg_uid_shift)
         char tree[] = "/tmp/unifiedXXXXXX", pid_string[DECIMAL_STR_MAX(pid) + 1];
         bool undo_mount = false;
         const char *fn;
-        int unified, r;
+        int r;
 
-        unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
-        if (unified < 0)
-                return log_error_errno(unified, "Failed to determine whether the unified hierarchy is used: %m");
-
-        if ((unified > 0) == (unified_requested >= CGROUP_UNIFIED_SYSTEMD))
+        if (cg_unified(SYSTEMD_CGROUP_CONTROLLER) == (unified_requested >= CGROUP_UNIFIED_SYSTEMD))
                 return 0;
 
         /* When the host uses the legacy cgroup setup, but the
@@ -100,7 +96,7 @@ int sync_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t arg_uid_shift)
         if (!mkdtemp(tree))
                 return log_error_errno(errno, "Failed to generate temporary mount point for unified hierarchy: %m");
 
-        if (unified)
+        if (cg_unified(SYSTEMD_CGROUP_CONTROLLER))
                 r = mount_verbose(LOG_ERR, "cgroup", tree, "cgroup",
                                   MS_NOSUID|MS_NOEXEC|MS_NODEV, "none,name=systemd,xattr");
         else
@@ -142,7 +138,7 @@ finish:
 int create_subcgroup(pid_t pid, CGroupUnified unified_requested) {
         _cleanup_free_ char *cgroup = NULL;
         const char *child;
-        int unified, r;
+        int r;
         CGroupMask supported;
 
         /* In the unified hierarchy inner nodes may only contain
@@ -154,10 +150,7 @@ int create_subcgroup(pid_t pid, CGroupUnified unified_requested) {
         if (unified_requested == CGROUP_UNIFIED_NONE)
                 return 0;
 
-        unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
-        if (unified < 0)
-                return log_error_errno(unified, "Failed to determine whether the unified hierarchy is used: %m");
-        if (unified == 0)
+        if (!cg_unified(SYSTEMD_CGROUP_CONTROLLER))
                 return 0;
 
         r = cg_mask_supported(&supported);
diff --git a/src/nspawn/nspawn-mount.c b/src/nspawn/nspawn-mount.c
index 4b2838b752..1493ef6aad 100644
--- a/src/nspawn/nspawn-mount.c
+++ b/src/nspawn/nspawn-mount.c
@@ -994,7 +994,7 @@ static int mount_legacy_cgns_supported(
                         return r;
         }
 
-        if (cg_all_unified() > 0)
+        if (cg_all_unified())
                 goto skip_controllers;
 
         controllers = set_new(&string_hash_ops);
@@ -1091,7 +1091,7 @@ static int mount_legacy_cgns_unsupported(
                         return r;
         }
 
-        if (cg_all_unified() > 0)
+        if (cg_all_unified())
                 goto skip_controllers;
 
         controllers = set_new(&string_hash_ops);
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index f5956bcb15..75b6728688 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -316,7 +316,7 @@ static int custom_mount_check_all(void) {
 
 static int detect_unified_cgroup_hierarchy(const char *directory) {
         const char *e;
-        int r, all_unified, systemd_unified;
+        int r;
 
         /* Allow the user to control whether the unified hierarchy is used */
         e = getenv("UNIFIED_CGROUP_HIERARCHY");
@@ -332,15 +332,8 @@ static int detect_unified_cgroup_hierarchy(const char *directory) {
                 return 0;
         }
 
-        all_unified = cg_all_unified();
-        systemd_unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
-
-        if (all_unified < 0 || systemd_unified < 0)
-                return log_error_errno(all_unified < 0 ? all_unified : systemd_unified,
-                                       "Failed to determine whether the unified cgroups hierarchy is used: %m");
-
         /* Otherwise inherit the default from the host system */
-        if (all_unified > 0) {
+        if (cg_all_unified()) {
                 /* Unified cgroup hierarchy support was added in 230. Unfortunately the detection
                  * routine only detects 231, so we'll have a false negative here for 230. */
                 r = systemd_installation_has_version(directory, 230);
@@ -350,7 +343,7 @@ static int detect_unified_cgroup_hierarchy(const char *directory) {
                         arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
                 else
                         arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
-        } else if (systemd_unified > 0) {
+        } else if (cg_unified(SYSTEMD_CGROUP_CONTROLLER)) {
                 /* Mixed cgroup hierarchy support was added in 232 */
                 r = systemd_installation_has_version(directory, 232);
                 if (r < 0)
@@ -3533,7 +3526,10 @@ int main(int argc, char *argv[]) {
 
         log_parse_environment();
         log_open();
-        cg_unified_flush();
+
+        r = cg_unified_flush();
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine whether the unified cgroups hierarchy is used: %m");
 
         /* Make sure rename_process() in the stub init process can work */
         saved_argv = argv;