cgroups: check for empty cgroups on freeze/unfreeze

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index 6953817b3b8dbf973e68cd3f2b2b952977d61667..59098ca3fb4e88adf30f20c2cfee6df0ba859a1c 100644 (file)
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -2003,6 +2003,9 @@ __cgfsng_ops static bool cgfsng_freeze(struct cgroup_ops *ops)
        __do_fclose FILE *f = NULL;
        struct hierarchy *h;
 
+       if (!ops->hierarchies)
+               return true;
+
        if (ops->cgroup_layout != CGROUP_LAYOUT_UNIFIED) {
                h = get_hierarchy(ops, "freezer");
                if (!h)
@@ -2054,6 +2057,9 @@ __cgfsng_ops static bool cgfsng_unfreeze(struct cgroup_ops *ops)
        __do_free char *fullpath = NULL;
        struct hierarchy *h;
 
+       if (!ops->hierarchies)
+               return true;
+
        if (ops->cgroup_layout != CGROUP_LAYOUT_UNIFIED) {
                h = get_hierarchy(ops, "freezer");
                if (!h)