@@ -6,7 +6,7 @@ type DeviceSet interface {

 	DeactivateDevice(hash string) error

 	RemoveDevice(hash string) error

 	MountDevice(hash, path string) error

-	UnmountDevice(hash, path string) error

+	UnmountDevice(hash, path string, deactivate bool) error

 	HasDevice(hash string) bool

 	HasInitializedDevice(hash string) bool

 	HasActivatedDevice(hash string) bool

@@ -13,6 +13,7 @@ import (

 	"strconv"

 	"strings"

 	"syscall"

+	"sync"

 )

 const (

@@ -36,6 +37,7 @@ type MetaData struct {

 type DeviceSetDM struct {

 	MetaData

+	sync.Mutex

 	initialized      bool

 	root             string

 	devicePrefix     string

@@ -77,74 +79,6 @@ func (devices *DeviceSetDM) getPoolDevName() string {

 	return getDevName(devices.getPoolName())

 }

-func (devices *DeviceSetDM) createTask(t TaskType, name string) (*Task, error) {

-	task := TaskCreate(t)

-	if task == nil {

-		return nil, fmt.Errorf("Can't create task of type %d", int(t))

-	}

-	if err := task.SetName(name); err != nil {

-		return nil, fmt.Errorf("Can't set task name %s", name)

-	}

-	return task, nil

-}

-

-func (devices *DeviceSetDM) getInfo(name string) (*Info, error) {

-	task, err := devices.createTask(DeviceInfo, name)

-	if task == nil {

-		return nil, err

-	}

-	if err := task.Run(); err != nil {

-		return nil, err

-	}

-	return task.GetInfo()

-}

-

-func (devices *DeviceSetDM) getStatus(name string) (uint64, uint64, string, string, error) {

-	task, err := devices.createTask(DeviceStatus, name)

-	if task == nil {

-		utils.Debugf("getStatus: Error createTask: %s", err)

-		return 0, 0, "", "", err

-	}

-	if err := task.Run(); err != nil {

-		utils.Debugf("getStatus: Error Run: %s", err)

-		return 0, 0, "", "", err

-	}

-

-	devinfo, err := task.GetInfo()

-	if err != nil {

-		utils.Debugf("getStatus: Error GetInfo: %s", err)

-		return 0, 0, "", "", err

-	}

-	if devinfo.Exists == 0 {

-		utils.Debugf("getStatus: Non existing device %s", name)

-		return 0, 0, "", "", fmt.Errorf("Non existing device %s", name)

-	}

-

-	_, start, length, target_type, params := task.GetNextTarget(0)

-	return start, length, target_type, params, nil

-}

-

-func (devices *DeviceSetDM) setTransactionId(oldId uint64, newId uint64) error {

-	task, err := devices.createTask(DeviceTargetMsg, devices.getPoolDevName())

-	if task == nil {

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-

-	if err := task.SetSector(0); err != nil {

-		return fmt.Errorf("Can't set sector")

-	}

-

-	if err := task.SetMessage(fmt.Sprintf("set_transaction_id %d %d", oldId, newId)); err != nil {

-		return fmt.Errorf("Can't set message")

-	}

-

-	if err := task.Run(); err != nil {

-		return fmt.Errorf("Error running setTransactionId")

-	}

-	return nil

-}

-

 func (devices *DeviceSetDM) hasImage(name string) bool {

 	dirname := devices.loopbackDir()

 	filename := path.Join(dirname, name)

@@ -178,194 +112,6 @@ func (devices *DeviceSetDM) ensureImage(name string, size int64) (string, error)

 	return filename, nil

 }

-func (devices *DeviceSetDM) createPool(dataFile *os.File, metadataFile *os.File) error {

-	utils.Debugf("Activating device-mapper pool %s", devices.getPoolName())

-	task, err := devices.createTask(DeviceCreate, devices.getPoolName())

-	if task == nil {

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-

-	size, err := GetBlockDeviceSize(dataFile)

-	if err != nil {

-		return fmt.Errorf("Can't get data size")

-	}

-

-	params := metadataFile.Name() + " " + dataFile.Name() + " 512 8192"

-	if err := task.AddTarget(0, size/512, "thin-pool", params); err != nil {

-		return fmt.Errorf("Can't add target")

-	}

-

-	var cookie uint32 = 0

-	if err := task.SetCookie(&cookie, 0); err != nil {

-		return fmt.Errorf("Can't set cookie")

-	}

-

-	if err := task.Run(); err != nil {

-		return fmt.Errorf("Error running DeviceCreate")

-	}

-

-	UdevWait(cookie)

-

-	return nil

-}

-

-func (devices *DeviceSetDM) suspendDevice(info *DevInfo) error {

-	task, err := devices.createTask(DeviceSuspend, info.Name())

-	if task == nil {

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-	if err := task.Run(); err != nil {

-		return fmt.Errorf("Error running DeviceSuspend")

-	}

-	return nil

-}

-

-func (devices *DeviceSetDM) resumeDevice(info *DevInfo) error {

-	task, err := devices.createTask(DeviceResume, info.Name())

-	if task == nil {

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-

-	var cookie uint32 = 0

-	if err := task.SetCookie(&cookie, 0); err != nil {

-		return fmt.Errorf("Can't set cookie")

-	}

-

-	if err := task.Run(); err != nil {

-		return fmt.Errorf("Error running DeviceSuspend")

-	}

-

-	UdevWait(cookie)

-

-	return nil

-}

-

-func (devices *DeviceSetDM) createDevice(deviceId int) error {

-	task, err := devices.createTask(DeviceTargetMsg, devices.getPoolDevName())

-	if task == nil {

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-

-	if err := task.SetSector(0); err != nil {

-		return fmt.Errorf("Can't set sector")

-	}

-

-	if err := task.SetMessage(fmt.Sprintf("create_thin %d", deviceId)); err != nil {

-		return fmt.Errorf("Can't set message")

-	}

-

-	if err := task.Run(); err != nil {

-		return fmt.Errorf("Error running createDevice")

-	}

-	return nil

-}

-

-func (devices *DeviceSetDM) createSnapDevice(deviceId int, baseInfo *DevInfo) error {

-	devinfo, _ := devices.getInfo(baseInfo.Name())

-	doSuspend := devinfo != nil && devinfo.Exists != 0

-

-	if doSuspend {

-		if err := devices.suspendDevice(baseInfo); err != nil {

-			utils.Debugf("\n--->Err: %s\n", err)

-			return err

-		}

-	}

-

-	task, err := devices.createTask(DeviceTargetMsg, devices.getPoolDevName())

-	if task == nil {

-		devices.resumeDevice(baseInfo)

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-

-	if err := task.SetSector(0); err != nil {

-		devices.resumeDevice(baseInfo)

-		return fmt.Errorf("Can't set sector")

-	}

-

-	if err := task.SetMessage(fmt.Sprintf("create_snap %d %d", deviceId, baseInfo.DeviceId)); err != nil {

-		devices.resumeDevice(baseInfo)

-		return fmt.Errorf("Can't set message")

-	}

-

-	if err := task.Run(); err != nil {

-		devices.resumeDevice(baseInfo)

-		return fmt.Errorf("Error running DeviceCreate")

-	}

-

-	if doSuspend {

-		if err := devices.resumeDevice(baseInfo); err != nil {

-			utils.Debugf("\n--->Err: %s\n", err)

-			return err

-		}

-	}

-

-	return nil

-}

-

-func (devices *DeviceSetDM) deleteDevice(deviceId int) error {

-	task, err := devices.createTask(DeviceTargetMsg, devices.getPoolDevName())

-	if task == nil {

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-

-	if err := task.SetSector(0); err != nil {

-		return fmt.Errorf("Can't set sector")

-	}

-

-	if err := task.SetMessage(fmt.Sprintf("delete %d", deviceId)); err != nil {

-		return fmt.Errorf("Can't set message")

-	}

-

-	if err := task.Run(); err != nil {

-		return fmt.Errorf("Error running deleteDevice")

-	}

-	return nil

-}

-

-func (devices *DeviceSetDM) removeDevice(name string) error {

-	task, err := devices.createTask(DeviceRemove, name)

-	if task == nil {

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-	if err = task.Run(); err != nil {

-		return fmt.Errorf("Error running removeDevice")

-	}

-	return nil

-}

-

-func (devices *DeviceSetDM) activateDevice(info *DevInfo) error {

-	task, err := devices.createTask(DeviceCreate, info.Name())

-	if task == nil {

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-

-	params := fmt.Sprintf("%s %d", devices.getPoolDevName(), info.DeviceId)

-	if err := task.AddTarget(0, info.Size/512, "thin", params); err != nil {

-		return fmt.Errorf("Can't add target")

-	}

-

-	var cookie uint32 = 0

-	if err := task.SetCookie(&cookie, 0); err != nil {

-		return fmt.Errorf("Can't set cookie")

-	}

-

-	if err := task.Run(); err != nil {

-		return fmt.Errorf("Error running DeviceCreate")

-	}

-

-	UdevWait(cookie)

-

-	return nil

-}

-

 func (devices *DeviceSetDM) allocateDeviceId() int {

 	// TODO: Add smarter reuse of deleted devices

 	id := devices.nextFreeDevice

@@ -412,7 +158,7 @@ func (devices *DeviceSetDM) saveMetadata() error {

 	}

 	if devices.NewTransactionId != devices.TransactionId {

-		if err = devices.setTransactionId(devices.TransactionId, devices.NewTransactionId); err != nil {

+		if err = setTransactionId(devices.getPoolDevName(), devices.TransactionId, devices.NewTransactionId); err != nil {

 			utils.Debugf("\n--->Err: %s\n", err)

 			return err

 		}

@@ -448,11 +194,11 @@ func (devices *DeviceSetDM) activateDeviceIfNeeded(hash string) error {

 		return fmt.Errorf("Unknown device %s", hash)

 	}

-	if devinfo, _ := devices.getInfo(info.Name()); devinfo != nil && devinfo.Exists != 0 {

+	if devinfo, _ := getInfo(info.Name()); devinfo != nil && devinfo.Exists != 0 {

 		return nil

 	}

-	return devices.activateDevice(info)

+	return activateDevice(devices.getPoolDevName(), info.Name(), info.DeviceId, info.Size)

 }

 func (devices *DeviceSetDM) createFilesystem(info *DevInfo) error {

@@ -470,7 +216,7 @@ func (devices *DeviceSetDM) createFilesystem(info *DevInfo) error {

 }

 func (devices *DeviceSetDM) loadMetaData() error {

-	_, _, _, params, err := devices.getStatus(devices.getPoolName())

+	_, _, _, params, err := getStatus(devices.getPoolName())

 	if err != nil {

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

@@ -521,7 +267,7 @@ func (devices *DeviceSetDM) setupBaseImage() error {

 	if oldInfo != nil && !oldInfo.Initialized {

 		utils.Debugf("Removing uninitialized base image")

-		if err := devices.RemoveDevice(""); err != nil {

+		if err := devices.removeDevice(""); err != nil {

 			utils.Debugf("\n--->Err: %s\n", err)

 			return err

 		}

@@ -532,14 +278,14 @@ func (devices *DeviceSetDM) setupBaseImage() error {

 	id := devices.allocateDeviceId()

 	// Create initial device

-	if err := devices.createDevice(id); err != nil {

+	if err := createDevice(devices.getPoolDevName(), id); err != nil {

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

 	}

 	info, err := devices.registerDevice(id, "", defaultBaseFsSize)

 	if err != nil {

-		_ = devices.deleteDevice(id)

+		_ = deleteDevice(devices.getPoolDevName(), id)

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

 	}

@@ -582,7 +328,7 @@ func setCloseOnExec(name string) {

 }

 func (devices *DeviceSetDM) initDevmapper() error {

-	info, err := devices.getInfo(devices.getPoolName())

+	info, err := getInfo(devices.getPoolName())

 	if info == nil {

 		utils.Debugf("Error device getInfo: %s", err)

 		return err

@@ -636,7 +382,7 @@ func (devices *DeviceSetDM) initDevmapper() error {

 	}

 	defer metadataFile.Close()

-	if err := devices.createPool(dataFile, metadataFile); err != nil {

+	if err := createPool(devices.getPoolName(), dataFile, metadataFile); err != nil {

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

 	}

@@ -657,6 +403,9 @@ func (devices *DeviceSetDM) initDevmapper() error {

 }

 func (devices *DeviceSetDM) AddDevice(hash, baseHash string) error {

+	devices.Lock()

+	defer devices.Unlock()

+

 	if err := devices.ensureInit(); err != nil {

 		utils.Debugf("Error init: %s\n", err)

 		return err

@@ -674,33 +423,28 @@ func (devices *DeviceSetDM) AddDevice(hash, baseHash string) error {

 	deviceId := devices.allocateDeviceId()

-	if err := devices.createSnapDevice(deviceId, baseInfo); err != nil {

+	if err := devices.createSnapDevice(devices.getPoolDevName(), deviceId, baseInfo.Name(), baseInfo.DeviceId); err != nil {

 		utils.Debugf("Error creating snap device: %s\n", err)

 		return err

 	}

 	if _, err := devices.registerDevice(deviceId, hash, baseInfo.Size); err != nil {

-		devices.deleteDevice(deviceId)

+		deleteDevice(devices.getPoolDevName(), deviceId)

 		utils.Debugf("Error registering device: %s\n", err)

 		return err

 	}

 	return nil

 }

-func (devices *DeviceSetDM) RemoveDevice(hash string) error {

-	if err := devices.ensureInit(); err != nil {

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-

+func (devices *DeviceSetDM) removeDevice(hash string) error {

 	info := devices.Devices[hash]

 	if info == nil {

 		return fmt.Errorf("hash %s doesn't exists", hash)

 	}

-	devinfo, _ := devices.getInfo(info.Name())

+	devinfo, _ := getInfo(info.Name())

 	if devinfo != nil && devinfo.Exists != 0 {

-		if err := devices.removeDevice(info.Name()); err != nil {

+		if err := removeDevice(info.Name()); err != nil {

 			utils.Debugf("Error removing device: %s\n", err)

 			return err

 		}

@@ -714,7 +458,7 @@ func (devices *DeviceSetDM) RemoveDevice(hash string) error {

 		}

 	}

-	if err := devices.deleteDevice(info.DeviceId); err != nil {

+	if err := deleteDevice(devices.getPoolDevName(), info.DeviceId); err != nil {

 		utils.Debugf("Error deleting device: %s\n", err)

 		return err

 	}

@@ -731,24 +475,32 @@ func (devices *DeviceSetDM) RemoveDevice(hash string) error {

 	return nil

 }

-func (devices *DeviceSetDM) DeactivateDevice(hash string) error {

+func (devices *DeviceSetDM) RemoveDevice(hash string) error {

+	devices.Lock()

+	defer devices.Unlock()

+

 	if err := devices.ensureInit(); err != nil {

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

 	}

+

+	return devices.removeDevice(hash)

+}

+

+func (devices *DeviceSetDM) deactivateDevice(hash string) error {

 	info := devices.Devices[hash]

 	if info == nil {

 		return fmt.Errorf("hash %s doesn't exists", hash)

 	}

-	devinfo, err := devices.getInfo(info.Name())

+	devinfo, err := getInfo(info.Name())

 	if err != nil {

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

 	}

 	if devinfo.Exists != 0 {

-		if err := devices.removeDevice(info.Name()); err != nil {

+		if err := removeDevice(info.Name()); err != nil {

 			utils.Debugf("\n--->Err: %s\n", err)

 			return err

 		}

@@ -757,7 +509,24 @@ func (devices *DeviceSetDM) DeactivateDevice(hash string) error {

 	return nil

 }

+func (devices *DeviceSetDM) DeactivateDevice(hash string) error {

+	devices.Lock()

+	defer devices.Unlock()

+

+	if err := devices.ensureInit(); err != nil {

+		utils.Debugf("\n--->Err: %s\n", err)

+		return err

+	}

+

+	utils.Debugf("DeactivateDevice %s", hash)

+	return devices.deactivateDevice(hash);

+}

+

+

 func (devices *DeviceSetDM) Shutdown() error {

+	devices.Lock()

+	defer devices.Unlock()

+

 	if !devices.initialized {

 		return nil

 	}

@@ -772,14 +541,14 @@ func (devices *DeviceSetDM) Shutdown() error {

 	}

 	for _, d := range devices.Devices {

-		if err := devices.DeactivateDevice(d.Hash); err != nil {

+		if err := devices.deactivateDevice(d.Hash); err != nil {

 			utils.Debugf("Shutdown deactivate %s , error: %s\n", d.Hash, err)

 		}

 	}

 	pool := devices.getPoolDevName()

-	if devinfo, err := devices.getInfo(pool); err == nil && devinfo.Exists != 0 {

-		if err := devices.removeDevice(pool); err != nil {

+	if devinfo, err := getInfo(pool); err == nil && devinfo.Exists != 0 {

+		if err := removeDevice(pool); err != nil {

 			utils.Debugf("Shutdown deactivate %s , error: %s\n", pool, err)

 		}

 	}

@@ -788,6 +557,9 @@ func (devices *DeviceSetDM) Shutdown() error {

 }

 func (devices *DeviceSetDM) MountDevice(hash, path string) error {

+	devices.Lock()

+	defer devices.Unlock()

+

 	if err := devices.ensureInit(); err != nil {

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

@@ -815,7 +587,10 @@ func (devices *DeviceSetDM) MountDevice(hash, path string) error {

 	return nil

 }

-func (devices *DeviceSetDM) UnmountDevice(hash, path string) error {

+func (devices *DeviceSetDM) UnmountDevice(hash, path string, deactivate bool) error {

+	devices.Lock()

+	defer devices.Unlock()

+

 	if err := syscall.Unmount(path, 0); err != nil {

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

@@ -827,10 +602,17 @@ func (devices *DeviceSetDM) UnmountDevice(hash, path string) error {

 		delete(devices.activeMounts, path)

 	}

+	if deactivate {

+		devices.deactivateDevice(hash)

+	}

+

 	return nil

 }

 func (devices *DeviceSetDM) HasDevice(hash string) bool {

+	devices.Lock()

+	defer devices.Unlock()

+

 	if err := devices.ensureInit(); err != nil {

 		return false

 	}

@@ -838,6 +620,9 @@ func (devices *DeviceSetDM) HasDevice(hash string) bool {

 }

 func (devices *DeviceSetDM) HasInitializedDevice(hash string) bool {

+	devices.Lock()

+	defer devices.Unlock()

+

 	if err := devices.ensureInit(); err != nil {

 		return false

 	}

@@ -847,6 +632,9 @@ func (devices *DeviceSetDM) HasInitializedDevice(hash string) bool {

 }

 func (devices *DeviceSetDM) HasActivatedDevice(hash string) bool {

+	devices.Lock()

+	defer devices.Unlock()

+

 	if err := devices.ensureInit(); err != nil {

 		return false

 	}

@@ -855,11 +643,14 @@ func (devices *DeviceSetDM) HasActivatedDevice(hash string) bool {

 	if info == nil {

 		return false

 	}

-	devinfo, _ := devices.getInfo(info.Name())

+	devinfo, _ := getInfo(info.Name())

 	return devinfo != nil && devinfo.Exists != 0

 }

 func (devices *DeviceSetDM) SetInitialized(hash string) error {

+	devices.Lock()

+	defer devices.Unlock()

+

 	if err := devices.ensureInit(); err != nil {

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

@@ -14,6 +14,10 @@ package devmapper

 #include <linux/fs.h>

 #include <errno.h>

+#ifndef LOOP_CTL_GET_FREE

+#define LOOP_CTL_GET_FREE       0x4C82

+#endif

+

 char*			attach_loop_device(const char *filename, int *loop_fd_out)

 {

   struct loop_info64	loopinfo = {0};

@@ -56,19 +60,18 @@ char*			attach_loop_device(const char *filename, int *loop_fd_out)

     loop_fd = open(buf, O_RDWR);

     if (loop_fd < 0 && errno == ENOENT) {

       close(fd);

-      perror("open");

       fprintf (stderr, "no available loopback device!");

       return NULL;

     } else if (loop_fd < 0)

       continue;

     if (ioctl (loop_fd, LOOP_SET_FD, (void *)(size_t)fd) < 0) {

-      perror("ioctl");

+      int errsv = errno;

       close(loop_fd);

       loop_fd = -1;

-      if (errno != EBUSY) {

+      if (errsv != EBUSY) {

         close (fd);

-        fprintf (stderr, "cannot set up loopback device %s", buf);

+        fprintf (stderr, "cannot set up loopback device %s: %s", buf, strerror(errsv));

         return NULL;

       }

       continue;

@@ -388,3 +391,255 @@ func RemoveDevice(name string) error {

 func free(p *C.char) {

 	C.free(unsafe.Pointer(p))

 }

+

+func createPool(poolName string, dataFile *os.File, metadataFile *os.File) error {

+	task, err := createTask(DeviceCreate, poolName)

+	if task == nil {

+		return err

+	}

+

+	size, err := GetBlockDeviceSize(dataFile)

+	if err != nil {

+		return fmt.Errorf("Can't get data size")

+	}

+

+	params := metadataFile.Name() + " " + dataFile.Name() + " 512 8192"

+	if err := task.AddTarget(0, size/512, "thin-pool", params); err != nil {

+		return fmt.Errorf("Can't add target")

+	}

+

+	var cookie uint32 = 0

+	if err := task.SetCookie(&cookie, 0); err != nil {

+		return fmt.Errorf("Can't set cookie")

+	}

+

+	if err := task.Run(); err != nil {

+		return fmt.Errorf("Error running DeviceCreate")

+	}

+

+	UdevWait(cookie)

+

+	return nil

+}

+

+func createTask(t TaskType, name string) (*Task, error) {

+	task := TaskCreate(t)

+	if task == nil {

+		return nil, fmt.Errorf("Can't create task of type %d", int(t))

+	}

+	if err := task.SetName(name); err != nil {

+		return nil, fmt.Errorf("Can't set task name %s", name)

+	}

+	return task, nil

+}

+

+func getInfo(name string) (*Info, error) {

+	task, err := createTask(DeviceInfo, name)

+	if task == nil {

+		return nil, err

+	}

+	if err := task.Run(); err != nil {

+		return nil, err

+	}

+	return task.GetInfo()

+}

+

+func getStatus(name string) (uint64, uint64, string, string, error) {

+	task, err := createTask(DeviceStatus, name)

+	if task == nil {

+		utils.Debugf("getStatus: Error createTask: %s", err)

+		return 0, 0, "", "", err

+	}

+	if err := task.Run(); err != nil {

+		utils.Debugf("getStatus: Error Run: %s", err)

+		return 0, 0, "", "", err

+	}

+

+	devinfo, err := task.GetInfo()

+	if err != nil {

+		utils.Debugf("getStatus: Error GetInfo: %s", err)

+		return 0, 0, "", "", err

+	}

+	if devinfo.Exists == 0 {

+		utils.Debugf("getStatus: Non existing device %s", name)

+		return 0, 0, "", "", fmt.Errorf("Non existing device %s", name)

+	}

+

+	_, start, length, target_type, params := task.GetNextTarget(0)

+	return start, length, target_type, params, nil

+}

+

+func setTransactionId(poolName string, oldId uint64, newId uint64) error {

+	task, err := createTask(DeviceTargetMsg, poolName)

+	if task == nil {

+		return err

+	}

+

+	if err := task.SetSector(0); err != nil {

+		return fmt.Errorf("Can't set sector")

+	}

+

+	if err := task.SetMessage(fmt.Sprintf("set_transaction_id %d %d", oldId, newId)); err != nil {

+		return fmt.Errorf("Can't set message")

+	}

+

+	if err := task.Run(); err != nil {

+		return fmt.Errorf("Error running setTransactionId")

+	}

+	return nil

+}

+

+func suspendDevice(name string) error {

+	task, err := createTask(DeviceSuspend, name)

+	if task == nil {

+		return err

+	}

+	if err := task.Run(); err != nil {

+		return fmt.Errorf("Error running DeviceSuspend")

+	}

+	return nil

+}

+

+func resumeDevice(name string) error {

+	task, err := createTask(DeviceResume, name)

+	if task == nil {

+		return err

+	}

+

+	var cookie uint32 = 0

+	if err := task.SetCookie(&cookie, 0); err != nil {

+		return fmt.Errorf("Can't set cookie")

+	}

+

+	if err := task.Run(); err != nil {

+		return fmt.Errorf("Error running DeviceSuspend")

+	}

+

+	UdevWait(cookie)

+

+	return nil

+}

+

+func createDevice(poolName string, deviceId int) error {

+	task, err := createTask(DeviceTargetMsg, poolName)

+	if task == nil {

+		return err

+	}

+

+	if err := task.SetSector(0); err != nil {

+		return fmt.Errorf("Can't set sector")

+	}

+

+	if err := task.SetMessage(fmt.Sprintf("create_thin %d", deviceId)); err != nil {

+		return fmt.Errorf("Can't set message")

+	}

+

+	if err := task.Run(); err != nil {

+		return fmt.Errorf("Error running createDevice")

+	}

+	return nil

+}

+

+func deleteDevice(poolName string, deviceId int) error {

+	task, err := createTask(DeviceTargetMsg, poolName)

+	if task == nil {

+		return err

+	}

+

+	if err := task.SetSector(0); err != nil {

+		return fmt.Errorf("Can't set sector")

+	}

+

+	if err := task.SetMessage(fmt.Sprintf("delete %d", deviceId)); err != nil {

+		return fmt.Errorf("Can't set message")

+	}

+

+	if err := task.Run(); err != nil {

+		return fmt.Errorf("Error running deleteDevice")

+	}

+	return nil

+}

+

+func removeDevice(name string) error {

+	task, err := createTask(DeviceRemove, name)

+	if task == nil {

+		return err

+	}

+	if err = task.Run(); err != nil {

+		return fmt.Errorf("Error running removeDevice")

+	}

+	return nil

+}

+

+func activateDevice(poolName string, name string, deviceId int, size uint64) error {

+	task, err := createTask(DeviceCreate, name)

+	if task == nil {

+		return err

+	}

+

+	params := fmt.Sprintf("%s %d", poolName, deviceId)

+	if err := task.AddTarget(0, size/512, "thin", params); err != nil {

+		return fmt.Errorf("Can't add target")

+	}

+

+	var cookie uint32 = 0

+	if err := task.SetCookie(&cookie, 0); err != nil {

+		return fmt.Errorf("Can't set cookie")

+	}

+

+	if err := task.Run(); err != nil {

+		return fmt.Errorf("Error running DeviceCreate")

+	}

+

+	UdevWait(cookie)

+

+	return nil

+}

+

+func (devices *DeviceSetDM) createSnapDevice(poolName string, deviceId int, baseName string, baseDeviceId int) error {

+	devinfo, _ := getInfo(baseName)

+	doSuspend := devinfo != nil && devinfo.Exists != 0

+

+	if doSuspend {

+		if err := suspendDevice(baseName); err != nil {

+			return err

+		}

+	}

+

+	task, err := createTask(DeviceTargetMsg, poolName)

+	if task == nil {

+		if doSuspend {

+			resumeDevice(baseName)

+		}

+		return err

+	}

+

+	if err := task.SetSector(0); err != nil {

+		if doSuspend {

+			resumeDevice(baseName)

+		}

+		return fmt.Errorf("Can't set sector")

+	}

+

+	if err := task.SetMessage(fmt.Sprintf("create_snap %d %d", deviceId, baseDeviceId)); err != nil {

+		if doSuspend {

+			resumeDevice(baseName)

+		}

+		return fmt.Errorf("Can't set message")

+	}

+

+	if err := task.Run(); err != nil {

+		if doSuspend {

+			resumeDevice(baseName)

+		}

+		return fmt.Errorf("Error running DeviceCreate")

+	}

+

+	if doSuspend {

+		if err := resumeDevice(baseName); err != nil {

+			return err

+		}

+	}

+

+	return nil

+}

@@ -391,14 +391,14 @@ func (image *Image) ensureImageDevice(devices DeviceSet) error {

 	if err := ioutil.WriteFile(path.Join(mountDir, ".docker-id"), []byte(image.ID), 0600); err != nil {

 		utils.Debugf("Error writing file: %s", err)

-		devices.UnmountDevice(image.ID, mountDir)

+		devices.UnmountDevice(image.ID, mountDir, true)

 		devices.RemoveDevice(image.ID)

 		return err

 	}

 	if err = image.applyLayer(layerPath(root), mountDir); err != nil {

 		utils.Debugf("Error applying layer: %s", err)

-		devices.UnmountDevice(image.ID, mountDir)