From 949877915f56d89eab5c79705b94da0c82b707d4 Mon Sep 17 00:00:00 2001
From: Alexander Larsson <alexl@redhat.com>
Date: Fri, 14 Mar 2014 10:47:49 +0100
Subject: [PATCH] cgroups: Splity out Apply/Cleanup to separate file/interface

This leaves only the generic cgroup helper functions in cgroups.go and
will allow easy implementations of other cgroup managers.

This also wires up the call to Cleanup the cgroup which was missing
before.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
---
 nsinit/exec.go | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/nsinit/exec.go b/nsinit/exec.go
index 61286cc1..a44faafe 100644
--- a/nsinit/exec.go
+++ b/nsinit/exec.go
@@ -3,6 +3,7 @@
 package nsinit
 
 import (
+	"github.com/dotcloud/docker/pkg/cgroups"
 	"github.com/dotcloud/docker/pkg/libcontainer"
 	"github.com/dotcloud/docker/pkg/libcontainer/network"
 	"github.com/dotcloud/docker/pkg/system"
@@ -61,10 +62,15 @@ func (ns *linuxNs) Exec(container *libcontainer.Container, term Terminal, args [
 	// Do this before syncing with child so that no children
 	// can escape the cgroup
 	ns.logger.Println("setting cgroups")
-	if err := ns.SetupCgroups(container, command.Process.Pid); err != nil {
+	activeCgroup, err := ns.SetupCgroups(container, command.Process.Pid)
+	if err != nil {
 		command.Process.Kill()
 		return -1, err
 	}
+	if activeCgroup != nil {
+		defer activeCgroup.Cleanup()
+	}
+
 	ns.logger.Println("setting up network")
 	if err := ns.InitializeNetworking(container, command.Process.Pid, syncPipe); err != nil {
 		command.Process.Kill()
@@ -85,13 +91,11 @@ func (ns *linuxNs) Exec(container *libcontainer.Container, term Terminal, args [
 	return status, err
 }
 
-func (ns *linuxNs) SetupCgroups(container *libcontainer.Container, nspid int) error {
+func (ns *linuxNs) SetupCgroups(container *libcontainer.Container, nspid int) (cgroups.ActiveCgroup, error) {
 	if container.Cgroups != nil {
-		if err := container.Cgroups.Apply(nspid); err != nil {
-			return err
-		}
+		return container.Cgroups.Apply(nspid)
 	}
-	return nil
+	return nil, nil
 }
 
 func (ns *linuxNs) InitializeNetworking(container *libcontainer.Container, nspid int, pipe *SyncPipe) error {