Don't cache exec and mounter in RBD volume plugin

pkg/volume/rbd/attacher.go

@@ -27,6 +27,7 @@ import (
 	"k8s.io/kubernetes/pkg/util/mount"
 	"k8s.io/kubernetes/pkg/volume"
 	volutil "k8s.io/kubernetes/pkg/volume/util"
+	"k8s.io/kubernetes/pkg/volume/util/volumehelper"
 )
 
 // NewAttacher implements AttachableVolumePlugin.NewAttacher.
@@ -38,6 +39,7 @@ func (plugin *rbdPlugin) newAttacherInternal(manager diskManager) (volume.Attach
 	return &rbdAttacher{
 		plugin:  plugin,
 		manager: manager,
+		mounter: volumehelper.NewSafeFormatAndMountFromHost(plugin.GetPluginName(), plugin.host),
 	}, nil
 }
 
@@ -50,6 +52,7 @@ func (plugin *rbdPlugin) newDetacherInternal(manager diskManager) (volume.Detach
 	return &rbdDetacher{
 		plugin:  plugin,
 		manager: manager,
+		mounter: volumehelper.NewSafeFormatAndMountFromHost(plugin.GetPluginName(), plugin.host),
 	}, nil
 }
 
@@ -62,6 +65,7 @@ func (plugin *rbdPlugin) GetDeviceMountRefs(deviceMountPath string) ([]string, e
 // rbdAttacher implements volume.Attacher interface.
 type rbdAttacher struct {
 	plugin  *rbdPlugin
+	mounter *mount.SafeFormatAndMount
 	manager diskManager
 }
 
@@ -124,7 +128,7 @@ func (attacher *rbdAttacher) GetDeviceMountPath(spec *volume.Spec) (string, erro
 // This method is idempotent, callers are responsible for retrying on failure.
 func (attacher *rbdAttacher) MountDevice(spec *volume.Spec, devicePath string, deviceMountPath string) error {
 	glog.V(4).Infof("rbd: mouting device %s to %s", devicePath, deviceMountPath)
-	notMnt, err := attacher.plugin.mounter.IsLikelyNotMountPoint(deviceMountPath)
+	notMnt, err := attacher.mounter.IsLikelyNotMountPoint(deviceMountPath)
 	if err != nil {
 		if os.IsNotExist(err) {
 			if err := os.MkdirAll(deviceMountPath, 0750); err != nil {
@@ -151,7 +155,7 @@ func (attacher *rbdAttacher) MountDevice(spec *volume.Spec, devicePath string, d
 		options = append(options, "ro")
 	}
 	mountOptions := volume.MountOptionFromSpec(spec, options...)
-	err = attacher.plugin.mounter.FormatAndMount(devicePath, deviceMountPath, fstype, mountOptions)
+	err = attacher.mounter.FormatAndMount(devicePath, deviceMountPath, fstype, mountOptions)
 	if err != nil {
 		os.Remove(deviceMountPath)
 		return fmt.Errorf("rbd: failed to mount device %s at %s (fstype: %s), error %v", devicePath, deviceMountPath, fstype, err)
@@ -164,6 +168,7 @@ func (attacher *rbdAttacher) MountDevice(spec *volume.Spec, devicePath string, d
 type rbdDetacher struct {
 	plugin  *rbdPlugin
 	manager diskManager
+	mounter *mount.SafeFormatAndMount
 }
 
 var _ volume.Detacher = &rbdDetacher{}
@@ -185,7 +190,7 @@ func (detacher *rbdDetacher) UnmountDevice(deviceMountPath string) error {
 		glog.Warningf("Warning: Unmount skipped because path does not exist: %v", deviceMountPath)
 		return nil
 	}
-	devicePath, cnt, err := mount.GetDeviceNameFromMount(detacher.plugin.mounter, deviceMountPath)
+	devicePath, cnt, err := mount.GetDeviceNameFromMount(detacher.mounter, deviceMountPath)
 	if err != nil {
 		return err
 	}
@@ -195,7 +200,7 @@ func (detacher *rbdDetacher) UnmountDevice(deviceMountPath string) error {
 	if cnt == 1 {
 		// Unmount the device from the device mount point.
 		glog.V(4).Infof("rbd: unmouting device mountpoint %s", deviceMountPath)
-		if err = detacher.plugin.mounter.Unmount(deviceMountPath); err != nil {
+		if err = detacher.mounter.Unmount(deviceMountPath); err != nil {
 			return err
 		}
 		glog.V(3).Infof("rbd: successfully umount device mountpath %s", deviceMountPath)

pkg/volume/rbd/rbd.go

@@ -41,14 +41,12 @@ var (
 
 // This is the primary entrypoint for volume plugins.
 func ProbeVolumePlugins() []volume.VolumePlugin {
-	return []volume.VolumePlugin{&rbdPlugin{nil, nil, nil}}
+	return []volume.VolumePlugin{&rbdPlugin{}}
 }
 
 // rbdPlugin implements Volume.VolumePlugin.
 type rbdPlugin struct {
-	host    volume.VolumeHost
-	exec    mount.Exec
-	mounter *mount.SafeFormatAndMount
+	host volume.VolumeHost
 }
 
 var _ volume.VolumePlugin = &rbdPlugin{}
@@ -74,8 +72,6 @@ func getPath(uid types.UID, volName string, host volume.VolumeHost) string {
 
 func (plugin *rbdPlugin) Init(host volume.VolumeHost) error {
 	plugin.host = host
-	plugin.exec = host.GetExec(plugin.GetPluginName())
-	plugin.mounter = volumehelper.NewSafeFormatAndMountFromHost(plugin.GetPluginName(), plugin.host)
 	return nil
 }
 
@@ -505,8 +501,8 @@ func newRBD(podUID types.UID, volName string, image string, pool string, readOnl
 		Pool:            pool,
 		ReadOnly:        readOnly,
 		plugin:          plugin,
-		mounter:         plugin.mounter,
-		exec:            plugin.exec,
+		mounter:         volumehelper.NewSafeFormatAndMountFromHost(plugin.GetPluginName(), plugin.host),
+		exec:            plugin.host.GetExec(plugin.GetPluginName()),
 		manager:         manager,
 		MetricsProvider: volume.NewMetricsStatFS(getPath(podUID, volName, plugin.host)),
 	}

pkg/volume/rbd/rbd_util.go

@@ -297,7 +297,8 @@ func (util *RBDUtil) DetachDisk(plugin *rbdPlugin, deviceMountPath string, devic
 	var err error
 	if len(device) > 0 {
 		// rbd unmap
-		_, err = plugin.exec.Run("rbd", "unmap", device)
+		exec := plugin.host.GetExec(plugin.GetPluginName())
+		_, err = exec.Run("rbd", "unmap", device)
 		if err != nil {
 			return rbdErrors(err, fmt.Errorf("rbd: failed to unmap device %s:Error: %v", device, err))
 		}