@@ -100,6 +100,25 @@ Here is the list of supported options:

     ``docker -d --storage-opt dm.mountopt=nodiscard``

+ *  `dm.thinpooldev`

+

+    Specifies a custom blockdevice to use for the thin pool.

+

+    If using a block device for device mapper storage, ideally lvm2

+    would be used to create/manage the thin-pool volume that is then

+    handed to docker to exclusively create/manage the thin and thin

+    snapshot volumes needed for it's containers.  Managing the thin-pool

+    outside of docker makes for the most feature-rich method of having

+    docker utilize device mapper thin provisioning as the backing

+    storage for docker's containers.  lvm2-based thin-pool management

+    feature highlights include: automatic or interactive thin-pool

+    resize support, dynamically change thin-pool features, automatic

+    thinp metadata checking when lvm2 activates the thin-pool, etc.

+

+    Example use:

+

+    ``docker -d --storage-opt dm.thinpooldev=/dev/mapper/thin-pool``

+

  *  `dm.datadev`

     Specifies a custom blockdevice to use for data for the thin pool.

@@ -84,6 +84,7 @@ type DeviceSet struct {

 	metadataDevice       string

 	doBlkDiscard         bool

 	thinpBlockSize       uint32

+	thinPoolDevice       string

 }

 type DiskUsage struct {

@@ -150,7 +151,10 @@ func (devices *DeviceSet) oldMetadataFile() string {

 }

 func (devices *DeviceSet) getPoolName() string {

-	return devices.devicePrefix + "-pool"

+	if devices.thinPoolDevice == "" {

+		return devices.devicePrefix + "-pool"

+	}

+	return devices.thinPoolDevice

 }

 func (devices *DeviceSet) getPoolDevName() string {

@@ -411,7 +415,22 @@ func (devices *DeviceSet) setupBaseImage() error {

 		}

 	}

-	log.Debugf("Initializing base device-manager snapshot")

+	if devices.thinPoolDevice != "" && oldInfo == nil {

+		_, transactionId, dataUsed, _, _, _, err := devices.poolStatus()

+		if err != nil {

+			return err

+		}

+		if dataUsed != 0 {

+			return fmt.Errorf("Unable to take ownership of thin-pool (%s) that already has used data blocks",

+				devices.thinPoolDevice)

+		}

+		if transactionId != 0 {

+			return fmt.Errorf("Unable to take ownership of thin-pool (%s) with non-zero transaction Id",

+				devices.thinPoolDevice)

+		}

+	}

+

+	log.Debugf("Initializing base device-mapper thin volume")

 	id := devices.NextDeviceId

@@ -430,7 +449,7 @@ func (devices *DeviceSet) setupBaseImage() error {

 		return err

 	}

-	log.Debugf("Creating filesystem on base device-manager snapshot")

+	log.Debugf("Creating filesystem on base device-mapper thin volume")

 	if err = devices.activateDeviceIfNeeded(info); err != nil {

 		return err

@@ -605,7 +624,7 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error {

 	devices.devicePrefix = fmt.Sprintf("docker-%d:%d-%d", major(sysSt.Dev), minor(sysSt.Dev), sysSt.Ino)

 	log.Debugf("Generated prefix: %s", devices.devicePrefix)

-	// Check for the existence of the device <prefix>-pool

+	// Check for the existence of the thin-pool device

 	log.Debugf("Checking for existence of the pool '%s'", devices.getPoolName())

 	info, err := devicemapper.GetInfo(devices.getPoolName())

 	if info == nil {

@@ -624,7 +643,7 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error {

 	createdLoopback := false

 	// If the pool doesn't exist, create it

-	if info.Exists == 0 {

+	if info.Exists == 0 && devices.thinPoolDevice == "" {

 		log.Debugf("Pool doesn't exist. Creating it.")

 		var (

@@ -988,8 +1007,10 @@ func (devices *DeviceSet) Shutdown() error {

 	}

 	devices.Lock()

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

-		log.Debugf("Shutdown deactivate pool , error: %s", err)

+	if devices.thinPoolDevice == "" {

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

+			log.Debugf("Shutdown deactivate pool , error: %s", err)

+		}

 	}

 	devices.saveDeviceSetMetaData()

@@ -1275,6 +1296,8 @@ func NewDeviceSet(root string, doInit bool, options []string) (*DeviceSet, error

 			devices.metadataDevice = val

 		case "dm.datadev":

 			devices.dataDevice = val

+		case "dm.thinpooldev":

+			devices.thinPoolDevice = strings.TrimPrefix(val, "/dev/mapper/")

 		case "dm.blkdiscard":

 			foundBlkDiscard = true

 			devices.doBlkDiscard, err = strconv.ParseBool(val)

@@ -1294,7 +1317,7 @@ func NewDeviceSet(root string, doInit bool, options []string) (*DeviceSet, error

 	}

 	// By default, don't do blk discard hack on raw devices, its rarely useful and is expensive

-	if !foundBlkDiscard && devices.dataDevice != "" {

+	if !foundBlkDiscard && (devices.dataDevice != "" || devices.thinPoolDevice != "") {

 		devices.doBlkDiscard = false

 	}

@@ -384,7 +384,8 @@ func CreatePool(poolName string, dataFile, metadataFile *os.File, poolBlockSize

 	}

 	var cookie uint = 0

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

+	var flags uint16 = DmUdevDisableSubsystemRulesFlag | DmUdevDisableDiskRulesFlag | DmUdevDisableOtherRulesFlag

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

 		return fmt.Errorf("Can't set cookie %s", err)

 	}

 	defer UdevWait(cookie)

@@ -82,6 +82,12 @@ const (

 	LoNameSize       = C.LO_NAME_SIZE

 )

+const (

+	DmUdevDisableSubsystemRulesFlag = C.DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG

+	DmUdevDisableDiskRulesFlag      = C.DM_UDEV_DISABLE_DISK_RULES_FLAG

+	DmUdevDisableOtherRulesFlag     = C.DM_UDEV_DISABLE_OTHER_RULES_FLAG

+)

+

 var (

 	DmGetLibraryVersion    = dmGetLibraryVersionFct

 	DmGetNextTarget        = dmGetNextTargetFct