nspawn: check env var first, detect second

If we are going to use the env var to override the detection result
anyway, there is not point in doing the detection, especially that
it can fail.

1 files changed, 7 insertions, 7 deletions

diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index a08377b3a3..4ce0e2e0c1 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -320,13 +320,6 @@ static int detect_unified_cgroup_hierarchy(void) {
         const char *e;
         int r, all_unified, systemd_unified;
 
-        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");
-
         /* Allow the user to control whether the unified hierarchy is used */
         e = getenv("UNIFIED_CGROUP_HIERARCHY");
         if (e) {
@@ -341,6 +334,13 @@ static int detect_unified_cgroup_hierarchy(void) {
                 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)
                 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;