fix unified cgroups v2 setup

The cgroups v2 setup required the rc_cgroups_controllers variable
to be set to the list of controllers to enable regardless of whether the
mode was hybrid or unified.

This makes sense for hybrid mode since the controllers can't be in both
the cgroups v1 and v2 hierarchies, but for unified mode we should enable
all controllers that are configured in the kernel.

etc/rc.conf

@@ -198,10 +198,9 @@ rc_tty_number=12
 # "unified" mounts cgroups version 2 on /sys/fs/cgroup
 #rc_cgroup_mode="hybrid"
 
-# This is a list of controllers which should be enabled for cgroups version 2.
-# If hybrid mode is being used, controllers listed here will not be
-# available for cgroups version 1.
-# This is a global setting.
+# This is a list of controllers which should be enabled for cgroups version 2
+# when hybrid mode is being used.
+# Controllers listed here will not be available for cgroups version 1.
 #rc_cgroup_controllers=""
 
 # This variable contains the cgroups version 2 settings for your services.

init.d/cgroups.in

@@ -83,14 +83,22 @@ cgroup2_controllers()
 	local active cgroup_path x y
 	cgroup_path="$(cgroup2_find_path)"
 	[ -z "${cgroup_path}" ] && return 0
-	[ -e "${cgroup_path}/cgroup.controllers" ] &&
+	[ ! -e "${cgroup_path}/cgroup.controllers" ] && return 0
+	[ ! -e "${cgroup_path}/cgroup.subtree_control" ]&& return 0
 	read -r active < "${cgroup_path}/cgroup.controllers"
-	for x in ${rc_cgroup_controllers}; do
-		for y in ${active}; do
-		[ "$x" = "$y" ] &&
-			[ -e "${cgroup_path}/cgroup.subtree_control" ]&&
+	for x in ${active}; do
+	case "$rc_cgroup_mode" in
+		unified)
 			echo "+${x}"  > "${cgroup_path}/cgroup.subtree_control"
-		done
+			;;
+		hybrid)
+			for y in ${rc_cgroup_controllers}; do
+				if [ "$x" = "$y" ]; then
+					echo "+${x}"  > "${cgroup_path}/cgroup.subtree_control"
+				fi
+			done
+			;;
+		esac
 	done
 	return 0
 }