func configureVolumes(config *Config) error {
	volumesDriver, err := local.New(config.Root)
	if err != nil {
		return err
	}
	volumedrivers.Register(volumesDriver, volumesDriver.Name())
	return nil
}

func configureVolumes(config *Config) (*volumeStore, error) {
	volumesDriver, err := local.New(config.Root)
	if err != nil {
		return nil, err
	}
	volumedrivers.Register(volumesDriver, volumesDriver.Name())
	return newVolumeStore(volumesDriver.List()), nil
}

func configureVolumes(config *Config, rootUID, rootGID int) (*store.VolumeStore, error) {
	volumesDriver, err := local.New(config.Root, rootUID, rootGID)
	if err != nil {
		return nil, err
	}

	volumedrivers.Register(volumesDriver, volumesDriver.Name())
	return store.New(config.Root)
}

func (daemon *Daemon) configureVolumes(rootUID, rootGID int) (*store.VolumeStore, error) {
	volumesDriver, err := local.New(daemon.configStore.Root, rootUID, rootGID)
	if err != nil {
		return nil, err
	}

	if !volumedrivers.Register(volumesDriver, volumesDriver.Name()) {
		return nil, fmt.Errorf("local volume driver could not be registered")
	}
	return store.New(daemon.configStore.Root)
}

func configureVolumes(config *Config) (*store.VolumeStore, error) {
	volumesDriver, err := local.New(config.Root)
	if err != nil {
		return nil, err
	}

	volumedrivers.Register(volumesDriver, volumesDriver.Name())
	s := store.New()
	s.AddAll(volumesDriver.List())

	return s, nil
}

func initDaemonForVolumesTest(tmp string) (*Daemon, error) {
	daemon := &Daemon{
		repository: tmp,
		root:       tmp,
	}

	volumesDriver, err := local.New(tmp)
	if err != nil {
		return nil, err
	}
	volumedrivers.Register(volumesDriver, volumesDriver.Name())

	return daemon, nil
}

func initDaemonWithVolumeStore(tmp string) (*Daemon, error) {
	daemon := &Daemon{
		repository: tmp,
		root:       tmp,
		volumes:    store.New(),
	}

	volumesDriver, err := local.New(tmp, 0, 0)
	if err != nil {
		return nil, err
	}
	volumedrivers.Register(volumesDriver, volumesDriver.Name())

	return daemon, nil
}

func TestGetVolumeDefaultDriver(t *testing.T) {
	tmp, err := ioutil.TempDir("", "volume-test-")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmp)

	l, err := local.New(tmp)
	if err != nil {
		t.Fatal(err)
	}
	volumedrivers.Register(l, volume.DefaultDriverName)
	d, err := getVolumeDriver("missing")
	if err != nil {
		t.Fatal(err)
	}

	if d.Name() != volume.DefaultDriverName {
		t.Fatalf("Expected local driver, was %s\n", d.Name)
	}
}

func NewDaemon(config *Config, registryService *registry.Service) (daemon *Daemon, err error) {
	// Check for mutually incompatible config options
	if config.Bridge.Iface != "" && config.Bridge.IP != "" {
		return nil, fmt.Errorf("You specified -b & --bip, mutually exclusive options. Please specify only one.")
	}
	setDefaultMtu(config)

	if !config.Bridge.EnableIPTables && !config.Bridge.InterContainerCommunication {
		return nil, fmt.Errorf("You specified --iptables=false with --icc=false. ICC uses iptables to function. Please set --icc or --iptables to true.")
	}
	if !config.Bridge.EnableIPTables && config.Bridge.EnableIPMasq {
		config.Bridge.EnableIPMasq = false
	}
	config.DisableNetwork = config.Bridge.Iface == disableNetworkBridge

	// Check that the system is supported and we have sufficient privileges
	if runtime.GOOS != "linux" {
		return nil, fmt.Errorf("The Docker daemon is only supported on linux")
	}
	if os.Geteuid() != 0 {
		return nil, fmt.Errorf("The Docker daemon needs to be run as root")
	}
	if err := checkKernel(); err != nil {
		return nil, err
	}

	// set up SIGUSR1 handler to dump Go routine stacks
	setupSigusr1Trap()

	// set up the tmpDir to use a canonical path
	tmp, err := tempDir(config.Root)
	if err != nil {
		return nil, fmt.Errorf("Unable to get the TempDir under %s: %s", config.Root, err)
	}
	realTmp, err := fileutils.ReadSymlinkedDirectory(tmp)
	if err != nil {
		return nil, fmt.Errorf("Unable to get the full path to the TempDir (%s): %s", tmp, err)
	}
	os.Setenv("TMPDIR", realTmp)

	// get the canonical path to the Docker root directory
	var realRoot string
	if _, err := os.Stat(config.Root); err != nil && os.IsNotExist(err) {
		realRoot = config.Root
	} else {
		realRoot, err = fileutils.ReadSymlinkedDirectory(config.Root)
		if err != nil {
			return nil, fmt.Errorf("Unable to get the full path to root (%s): %s", config.Root, err)
		}
	}
	config.Root = realRoot
	// Create the root directory if it doesn't exists
	if err := os.MkdirAll(config.Root, 0700); err != nil && !os.IsExist(err) {
		return nil, err
	}

	// Set the default driver
	graphdriver.DefaultDriver = config.GraphDriver

	// Load storage driver
	driver, err := graphdriver.New(config.Root, config.GraphOptions)
	if err != nil {
		return nil, fmt.Errorf("error initializing graphdriver: %v", err)
	}
	logrus.Debugf("Using graph driver %s", driver)

	d := &Daemon{}
	d.driver = driver

	defer func() {
		if err != nil {
			if err := d.Shutdown(); err != nil {
				logrus.Error(err)
			}
		}
	}()

	// Verify logging driver type
	if config.LogConfig.Type != "none" {
		if _, err := logger.GetLogDriver(config.LogConfig.Type); err != nil {
			return nil, fmt.Errorf("error finding the logging driver: %v", err)
		}
	}
	logrus.Debugf("Using default logging driver %s", config.LogConfig.Type)

	if config.EnableSelinuxSupport {
		if selinuxEnabled() {
			// As Docker on btrfs and SELinux are incompatible at present, error on both being enabled
			if d.driver.String() == "btrfs" {
				return nil, fmt.Errorf("SELinux is not supported with the BTRFS graph driver")
			}
			logrus.Debug("SELinux enabled successfully")
		} else {
			logrus.Warn("Docker could not enable SELinux on the host system")
		}
	} else {
		selinuxSetDisabled()
	}

	daemonRepo := path.Join(config.Root, "containers")
//.........这里部分代码省略.........

func TestMigratePre17Volumes(t *testing.T) {
	rootDir, err := ioutil.TempDir("", "test-daemon-volumes")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(rootDir)

	volumeRoot := filepath.Join(rootDir, "volumes")
	err = os.MkdirAll(volumeRoot, 0755)
	if err != nil {
		t.Fatal(err)
	}

	containerRoot := filepath.Join(rootDir, "containers")
	cid := "1234"
	err = os.MkdirAll(filepath.Join(containerRoot, cid), 0755)

	vid := "5678"
	vfsPath := filepath.Join(rootDir, "vfs", "dir", vid)
	err = os.MkdirAll(vfsPath, 0755)
	if err != nil {
		t.Fatal(err)
	}

	config := []byte(`
		{
			"ID": "` + cid + `",
			"Volumes": {
				"/foo": "` + vfsPath + `",
				"/bar": "/foo",
				"/quux": "/quux"
			},
			"VolumesRW": {
				"/foo": true,
				"/bar": true,
				"/quux": false
			}
		}
	`)

	volStore, err := store.New(volumeRoot)
	if err != nil {
		t.Fatal(err)
	}
	drv, err := local.New(volumeRoot, 0, 0)
	if err != nil {
		t.Fatal(err)
	}
	volumedrivers.Register(drv, volume.DefaultDriverName)

	daemon := &Daemon{root: rootDir, repository: containerRoot, volumes: volStore}
	err = ioutil.WriteFile(filepath.Join(containerRoot, cid, "config.v2.json"), config, 600)
	if err != nil {
		t.Fatal(err)
	}
	c, err := daemon.load(cid)
	if err != nil {
		t.Fatal(err)
	}
	if err := daemon.verifyVolumesInfo(c); err != nil {
		t.Fatal(err)
	}

	expected := map[string]volume.MountPoint{
		"/foo":  {Destination: "/foo", RW: true, Name: vid},
		"/bar":  {Source: "/foo", Destination: "/bar", RW: true},
		"/quux": {Source: "/quux", Destination: "/quux", RW: false},
	}
	for id, mp := range c.MountPoints {
		x, exists := expected[id]
		if !exists {
			t.Fatal("volume not migrated")
		}
		if mp.Source != x.Source || mp.Destination != x.Destination || mp.RW != x.RW || mp.Name != x.Name {
			t.Fatalf("got unexpected mountpoint, expected: %+v, got: %+v", x, mp)
		}
	}
}