Add remove method to subsystems

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

cgroups/fs/apply_raw.go

@@ -25,6 +25,7 @@ var (
 
 type subsystem interface {
 	Set(*data) error
+	Remove(*data) error
 }
 
 type data struct {
@@ -94,24 +95,8 @@ func (raw *data) join(subsystem string) (string, error) {
 }
 
 func (raw *data) Cleanup() error {
-	get := func(subsystem string) string {
-		path, _ := raw.path(subsystem)
-		return path
-	}
-
-	for _, path := range []string{
-		get("memory"),
-		get("devices"),
-		get("cpu"),
-		get("cpuset"),
-		get("cpuacct"),
-		get("blkio"),
-		get("perf_event"),
-		get("freezer"),
-	} {
-		if path != "" {
-			os.RemoveAll(path)
-		}
+	for _, sys := range subsystems {
+		sys.Remove(raw)
 	}
 	return nil
 }
@@ -119,3 +104,13 @@ func (raw *data) Cleanup() error {
 func writeFile(dir, file, data string) error {
 	return ioutil.WriteFile(filepath.Join(dir, file), []byte(data), 0700)
 }
+
+func removePath(p string, err error) error {
+	if err != nil {
+		return err
+	}
+	if p != "" {
+		return os.RemoveAll(p)
+	}
+	return nil
+}

cgroups/fs/blkio.go

@@ -14,3 +14,7 @@ func (s *blkioGroup) Set(d *data) error {
 	}
 	return nil
 }
+
+func (s *blkioGroup) Remove(d *data) error {
+	return removePath(d.path("blkio"))
+}

cgroups/fs/cpu.go

@@ -21,3 +21,7 @@ func (s *cpuGroup) Set(d *data) error {
 	}
 	return nil
 }
+
+func (s *cpuGroup) Remove(d *data) error {
+	return removePath(d.path("cpu"))
+}

cgroups/fs/cpuacct.go

@@ -14,3 +14,7 @@ func (s *cpuacctGroup) Set(d *data) error {
 	}
 	return nil
 }
+
+func (s *cpuacctGroup) Remove(d *data) error {
+	return removePath(d.path("cpuacct"))
+}

cgroups/fs/cpuset.go

@@ -26,3 +26,7 @@ func (s *cpusetGroup) Set(d *data) error {
 	}
 	return nil
 }
+
+func (s *cpusetGroup) Remove(d *data) error {
+	return removePath(d.path("cpuset"))
+}

cgroups/fs/devices.go

@@ -59,3 +59,7 @@ func (s *devicesGroup) Set(d *data) error {
 	}
 	return nil
 }
+
+func (s *devicesGroup) Remove(d *data) error {
+	return removePath(d.path("devices"))
+}

cgroups/fs/freezer.go

@@ -14,3 +14,7 @@ func (s *freezerGroup) Set(d *data) error {
 	}
 	return nil
 }
+
+func (s *freezerGroup) Remove(d *data) error {
+	return removePath(d.path("freezer"))
+}

cgroups/fs/memory.go

@@ -39,3 +39,7 @@ func (s *memoryGroup) Set(d *data) error {
 	}
 	return nil
 }
+
+func (s *memoryGroup) Remove(d *data) error {
+	return removePath(d.path("memory"))
+}

cgroups/fs/perf_event.go

@@ -14,3 +14,7 @@ func (s *perfEventGroup) Set(d *data) error {
 	}
 	return nil
 }
+
+func (s *perfEventGroup) Remove(d *data) error {
+	return removePath(d.path("perf_event"))
+}