func BuildContext(driver, root string) (*Context, error) {
	d, err := graphdriver.GetDriver(driver, root, nil, nil, nil)
	if err != nil {
		return nil, err
	}

	g, err := graph.NewGraph(filepath.Join(root, "graph"), d, nil, nil)
	if err != nil {
		return nil, err
	}

	config := &graph.TagStoreConfig{
		Graph:  g,
		Events: events.New(),
		Registry: registry.NewService(&registry.Options{
			Mirrors:            opts.NewListOpts(nil),
			InsecureRegistries: *opts.NewListOptsRef(&internalDockerEndpoints, nil),
		}),
	}
	store, err := graph.NewTagStore(filepath.Join(root, "repositories-"+d.String()), config)
	if err != nil {
		return nil, err
	}

	return NewContext(store, g, d), nil
}

// initDriver ...
func (g *GraphTool) InitDriver() error {
	var err error
	g.graphDriver, err = graphdriver.New(g.DockerRoot, make([]string, 0))
	if err != nil {
		return err
	}
	g.graphHandler, err = graph.NewGraph(g.DockerRoot+"/graph", g.graphDriver)
	if err != nil {
		return err
	}
	return nil
}

func initGraph(c *cli.Context) (*graph.Graph, graphdriver.Driver) {
	drv := initDriver(c)
	homedir := filepath.Join(c.GlobalString("home"), "graph")
	g, err := graph.NewGraph(homedir, drv, nil, nil)
	if err != nil {
		fmt.Printf("Failed to instantiate graph: %s\n", err)
		os.Exit(1)
	}
	if c.GlobalBool("debug") {
		fmt.Fprintf(os.Stderr, "[DEBUG] %d images.\n", len(g.Map()))
	}
	return g, drv
}

func tempGraph(t *testing.T) (*graph.Graph, graphdriver.Driver) {
	tmp, err := ioutil.TempDir("", "docker-graph-")
	if err != nil {
		t.Fatal(err)
	}
	driver, err := graphdriver.New(tmp, nil)
	if err != nil {
		t.Fatal(err)
	}
	graph, err := graph.NewGraph(tmp, driver)
	if err != nil {
		t.Fatal(err)
	}
	return graph, driver
}

func initGraph() (*graph.Graph, error) {
	graphdriver.Register("devicemapper", devmapper.Init)
	graphdriver.DefaultDriver = "devicemapper"

	// Load storage driver
	driver, err := graphdriver.New(root, graphOptions)
	if err != nil {
		log.Errorf("Load storage driver error: %v", err)
		return nil, err
	}
	log.Debugf("Using graph driver %s", driver)

	log.Debugf("Creating images graph")
	g, err := graph.NewGraph(path.Join(root, "graph"), driver)
	if err != nil {
		log.Errorf("Creating images graph error: %v", err)
		return nil, err
	}
	return g, nil
}

func NewDaemon(config *Config, registryService *registry.Service) (daemon *Daemon, err error) {
	setDefaultMtu(config)

	// Ensure we have compatible configuration options
	if err := checkConfigOptions(config); err != nil {
		return nil, err
	}

	// Do we have a disabled network?
	config.DisableBridge = isBridgeNetworkDisabled(config)

	// Verify the platform is supported as a daemon
	if runtime.GOOS != "linux" && runtime.GOOS != "windows" {
		return nil, ErrSystemNotSupported
	}

	// Validate platform-specific requirements
	if err := checkSystem(); err != nil {
		return nil, err
	}

	// set up SIGUSR1 handler on Unix-like systems, or a Win32 global event
	// on Windows to dump Go routine stacks
	setupDumpStackTrap()

	// 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 := system.MkdirAll(config.Root, 0700); err != nil {
		return nil, err
	}

	// 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)

	// 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

	// Ensure the graph driver is shutdown at a later point
	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)

	// Configure and validate the kernels security support
	if err := configureKernelSecuritySupport(config, d.driver.String()); err != nil {
		return nil, err
	}

	daemonRepo := filepath.Join(config.Root, "containers")

	if err := system.MkdirAll(daemonRepo, 0700); err != nil {
		return nil, err
	}

	// Migrate the container if it is aufs and aufs is enabled
	if err := migrateIfDownlevel(d.driver, config.Root); err != nil {
		return nil, err
	}

	logrus.Debug("Creating images graph")
	g, err := graph.NewGraph(filepath.Join(config.Root, "graph"), d.driver)
//.........这里部分代码省略.........

func wireVolumeCreator(logger lager.Logger, graphRoot string) *rootfs_provider.CakeOrdinator {
	logger = logger.Session("volume-creator", lager.Data{"graphRoot": graphRoot})
	runner := &logging.Runner{CommandRunner: linux_command_runner.New(), Logger: logger}

	if err := os.MkdirAll(graphRoot, 0755); err != nil {
		logger.Fatal("failed-to-create-graph-directory", err)
	}

	dockerGraphDriver, err := graphdriver.New(graphRoot, nil)
	if err != nil {
		logger.Fatal("failed-to-construct-graph-driver", err)
	}

	backingStoresPath := filepath.Join(graphRoot, "backing_stores")
	if err := os.MkdirAll(backingStoresPath, 0660); err != nil {
		logger.Fatal("failed-to-mkdir-backing-stores", err)
	}

	graphRetrier := &retrier.Retrier{
		Timeout:         100 * time.Second,
		PollingInterval: 500 * time.Millisecond,
		Clock:           clock.NewClock(),
	}

	quotaedGraphDriver := &quotaed_aufs.QuotaedDriver{
		GraphDriver: dockerGraphDriver,
		Unmount:     quotaed_aufs.Unmount,
		BackingStoreMgr: &quotaed_aufs.BackingStore{
			RootPath: backingStoresPath,
			Logger:   logger.Session("backing-store-mgr"),
		},
		LoopMounter: &quotaed_aufs.Loop{
			Retrier: graphRetrier,
			Logger:  logger.Session("loop-mounter"),
		},
		Retrier:  graphRetrier,
		RootPath: graphRoot,
		Logger:   logger.Session("quotaed-driver"),
	}

	dockerGraph, err := graph.NewGraph(graphRoot, quotaedGraphDriver)
	if err != nil {
		logger.Fatal("failed-to-construct-graph", err)
	}

	var cake layercake.Cake = &layercake.Docker{
		Graph:  dockerGraph,
		Driver: quotaedGraphDriver,
	}

	if cake.DriverName() == "aufs" {
		cake = &layercake.AufsCake{
			Cake:      cake,
			Runner:    runner,
			GraphRoot: graphRoot,
		}
	}

	repoFetcher := &repository_fetcher.CompositeFetcher{
		LocalFetcher: &repository_fetcher.Local{
			Cake:              cake,
			DefaultRootFSPath: *rootFSPath,
			IDProvider:        repository_fetcher.LayerIDProvider{},
		},
	}

	maxId := sysinfo.Min(sysinfo.MustGetMaxValidUID(), sysinfo.MustGetMaxValidGID())
	mappingList := rootfs_provider.MappingList{
		{
			FromID: 0,
			ToID:   maxId,
			Size:   1,
		},
		{
			FromID: 1,
			ToID:   1,
			Size:   maxId - 1,
		},
	}

	rootFSNamespacer := &rootfs_provider.UidNamespacer{
		Logger: logger,
		Translator: rootfs_provider.NewUidTranslator(
			mappingList, // uid
			mappingList, // gid
		),
	}

	layerCreator := rootfs_provider.NewLayerCreator(
		cake, rootfs_provider.SimpleVolumeCreator{}, rootFSNamespacer)

	cakeOrdinator := rootfs_provider.NewCakeOrdinator(
		cake, repoFetcher, layerCreator, nil, logger.Session("cake-ordinator"),
	)
	return cakeOrdinator
}

func NewDaemonFromDirectory(config *Config, eng *engine.Engine) (*Daemon, error) {
	if config.Mtu == 0 {
		config.Mtu = getDefaultNetworkMtu()
	}
	// Check for mutually incompatible config options
	if config.BridgeIface != "" && config.BridgeIP != "" {
		return nil, fmt.Errorf("You specified -b & --bip, mutually exclusive options. Please specify only one.")
	}
	if !config.EnableIptables && !config.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.EnableIptables && config.EnableIpMasq {
		config.EnableIpMasq = false
	}
	config.DisableNetwork = config.BridgeIface == disableNetworkBridge

	// Claim the pidfile first, to avoid any and all unexpected race conditions.
	// Some of the init doesn't need a pidfile lock - but let's not try to be smart.
	if config.Pidfile != "" {
		if err := utils.CreatePidFile(config.Pidfile); err != nil {
			return nil, err
		}
		eng.OnShutdown(func() {
			// Always release the pidfile last, just in case
			utils.RemovePidFile(config.Pidfile)
		})
	}

	// 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 := checkKernelAndArch(); err != nil {
		return nil, err
	}

	// set up the TempDir to use a canonical path
	tmp, err := utils.TempDir(config.Root)
	if err != nil {
		return nil, fmt.Errorf("Unable to get the TempDir under %s: %s", config.Root, err)
	}
	realTmp, err := utils.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)
	if !config.EnableSelinuxSupport {
		selinuxSetDisabled()
	}

	// 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 = utils.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, err
	}
	log.Debugf("Using graph driver %s", driver)

	// As Docker on btrfs and SELinux are incompatible at present, error on both being enabled
	if selinuxEnabled() && config.EnableSelinuxSupport && driver.String() == "btrfs" {
		return nil, fmt.Errorf("SELinux is not supported with the BTRFS graph driver!")
	}

	daemonRepo := path.Join(config.Root, "containers")

	if err := os.MkdirAll(daemonRepo, 0700); err != nil && !os.IsExist(err) {
		return nil, err
	}

	// Migrate the container if it is aufs and aufs is enabled
	if err = migrateIfAufs(driver, config.Root); err != nil {
		return nil, err
	}

	log.Debugf("Creating images graph")
	g, err := graph.NewGraph(path.Join(config.Root, "graph"), driver)
	if err != nil {
		return nil, err
	}
//.........这里部分代码省略.........

func NewDaemonFromDirectory(config *daemonconfig.Config, eng *engine.Engine) (*Daemon, error) {
	if runtime.GOOS != "linux" {
		log.Fatalf("The Docker daemon is only supported on linux")
	}
	if os.Geteuid() != 0 {
		log.Fatalf("The Docker daemon needs to be run as root")
	}
	if err := checkKernelAndArch(); err != nil {
		log.Fatal(err)
	}

	// set up the TempDir to use a canonical path
	tmp, err := utils.TempDir(config.Root)
	if err != nil {
		log.Fatalf("Unable to get the TempDir under %s: %s", config.Root, err)
	}
	realTmp, err := utils.ReadSymlinkedDirectory(tmp)
	if err != nil {
		log.Fatalf("Unable to get the full path to the TempDir (%s): %s", tmp, err)
	}
	os.Setenv("TMPDIR", realTmp)
	if !config.EnableSelinuxSupport {
		selinuxSetDisabled()
	}

	// 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 = utils.ReadSymlinkedDirectory(config.Root)
		if err != nil {
			log.Fatalf("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, err
	}
	utils.Debugf("Using graph driver %s", driver)

	// As Docker on btrfs and SELinux are incompatible at present, error on both being enabled
	if config.EnableSelinuxSupport && driver.String() == "btrfs" {
		return nil, fmt.Errorf("SELinux is not supported with the BTRFS graph driver!")
	}

	daemonRepo := path.Join(config.Root, "containers")

	if err := os.MkdirAll(daemonRepo, 0700); err != nil && !os.IsExist(err) {
		return nil, err
	}

	// Migrate the container if it is aufs and aufs is enabled
	if err = migrateIfAufs(driver, config.Root); err != nil {
		return nil, err
	}

	utils.Debugf("Creating images graph")
	g, err := graph.NewGraph(path.Join(config.Root, "graph"), driver)
	if err != nil {
		return nil, err
	}

	// We don't want to use a complex driver like aufs or devmapper
	// for volumes, just a plain filesystem
	volumesDriver, err := graphdriver.GetDriver("vfs", config.Root, config.GraphOptions)
	if err != nil {
		return nil, err
	}
	utils.Debugf("Creating volumes graph")
	volumes, err := graph.NewGraph(path.Join(config.Root, "volumes"), volumesDriver)
	if err != nil {
		return nil, err
	}
	utils.Debugf("Creating repository list")
	repositories, err := graph.NewTagStore(path.Join(config.Root, "repositories-"+driver.String()), g)
	if err != nil {
		return nil, fmt.Errorf("Couldn't create Tag store: %s", err)
	}

	if !config.DisableNetwork {
		job := eng.Job("init_networkdriver")

		job.SetenvBool("EnableIptables", config.EnableIptables)
		job.SetenvBool("InterContainerCommunication", config.InterContainerCommunication)
		job.SetenvBool("EnableIpForward", config.EnableIpForward)
		job.Setenv("BridgeIface", config.BridgeIface)
		job.Setenv("BridgeIP", config.BridgeIP)
		job.Setenv("DefaultBindingIP", config.DefaultIp.String())

//.........这里部分代码省略.........

//.........这里部分代码省略.........
	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")

	if err := os.MkdirAll(daemonRepo, 0700); err != nil && !os.IsExist(err) {
		return nil, err
	}

	// Migrate the container if it is aufs and aufs is enabled
	if err := migrateIfAufs(d.driver, config.Root); err != nil {
		return nil, err
	}

	logrus.Debug("Creating images graph")
	g, err := graph.NewGraph(path.Join(config.Root, "graph"), d.driver)
	if err != nil {
		return nil, err
	}

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

	trustKey, err := api.LoadOrCreateTrustKey(config.TrustKeyPath)
	if err != nil {
		return nil, err
	}

	trustDir := path.Join(config.Root, "trust")
	if err := os.MkdirAll(trustDir, 0700); err != nil && !os.IsExist(err) {
		return nil, err
	}
	trustService, err := trust.NewTrustStore(trustDir)
	if err != nil {
		return nil, fmt.Errorf("could not create trust store: %s", err)
	}

	eventsService := events.New()
	logrus.Debug("Creating repository list")
	tagCfg := &graph.TagStoreConfig{
		Graph:    g,
		Key:      trustKey,
		Registry: registryService,
		Events:   eventsService,
		Trust:    trustService,

func (cmd *GuardianCommand) wireVolumeCreator(logger lager.Logger, graphRoot string, insecureRegistries, persistentImages []string) gardener.VolumeCreator {
	if graphRoot == "" {
		return gardener.NoopVolumeCreator{}
	}

	if cmd.Bin.ImagePlugin.Path() != "" {
		defaultRootFS, err := url.Parse(cmd.Containers.DefaultRootFSDir.Path())
		if err != nil {
			logger.Fatal("failed-to-parse-default-rootfs", err)
		}
		return imageplugin.New(cmd.Bin.ImagePlugin.Path(), linux_command_runner.New(), defaultRootFS, idMappings)
	}

	logger = logger.Session("volume-creator", lager.Data{"graphRoot": graphRoot})
	runner := &logging.Runner{CommandRunner: linux_command_runner.New(), Logger: logger}

	if err := os.MkdirAll(graphRoot, 0755); err != nil {
		logger.Fatal("failed-to-create-graph-directory", err)
	}

	dockerGraphDriver, err := graphdriver.New(graphRoot, nil)
	if err != nil {
		logger.Fatal("failed-to-construct-graph-driver", err)
	}

	backingStoresPath := filepath.Join(graphRoot, "backing_stores")
	if err := os.MkdirAll(backingStoresPath, 0660); err != nil {
		logger.Fatal("failed-to-mkdir-backing-stores", err)
	}

	quotaedGraphDriver := &quotaed_aufs.QuotaedDriver{
		GraphDriver: dockerGraphDriver,
		Unmount:     quotaed_aufs.Unmount,
		BackingStoreMgr: &quotaed_aufs.BackingStore{
			RootPath: backingStoresPath,
			Logger:   logger.Session("backing-store-mgr"),
		},
		LoopMounter: &quotaed_aufs.Loop{
			Retrier: retrier.New(retrier.ConstantBackoff(200, 500*time.Millisecond), nil),
			Logger:  logger.Session("loop-mounter"),
		},
		Retrier:  retrier.New(retrier.ConstantBackoff(200, 500*time.Millisecond), nil),
		RootPath: graphRoot,
		Logger:   logger.Session("quotaed-driver"),
	}

	dockerGraph, err := graph.NewGraph(graphRoot, quotaedGraphDriver)
	if err != nil {
		logger.Fatal("failed-to-construct-graph", err)
	}

	var cake layercake.Cake = &layercake.Docker{
		Graph:  dockerGraph,
		Driver: quotaedGraphDriver,
	}

	if cake.DriverName() == "aufs" {
		cake = &layercake.AufsCake{
			Cake:      cake,
			Runner:    runner,
			GraphRoot: graphRoot,
		}
	}

	repoFetcher := repository_fetcher.Retryable{
		RepositoryFetcher: &repository_fetcher.CompositeFetcher{
			LocalFetcher: &repository_fetcher.Local{
				Cake:              cake,
				DefaultRootFSPath: cmd.Containers.DefaultRootFSDir.Path(),
				IDProvider:        repository_fetcher.LayerIDProvider{},
			},
			RemoteFetcher: repository_fetcher.NewRemote(
				logger,
				cmd.Docker.Registry,
				cake,
				distclient.NewDialer(insecureRegistries),
				repository_fetcher.VerifyFunc(repository_fetcher.Verify),
			),
		},
		Logger: logger,
	}

	rootFSNamespacer := &rootfs_provider.UidNamespacer{
		Translator: rootfs_provider.NewUidTranslator(
			idMappings, // uid
			idMappings, // gid
		),
	}

	retainer := cleaner.NewRetainer()
	ovenCleaner := cleaner.NewOvenCleaner(retainer,
		cleaner.NewThreshold(int64(cmd.Graph.CleanupThresholdInMegabytes)*1024*1024),
	)

	imageRetainer := &repository_fetcher.ImageRetainer{
		GraphRetainer:             retainer,
		DirectoryRootfsIDProvider: repository_fetcher.LayerIDProvider{},
		DockerImageIDFetcher:      repoFetcher,

		NamespaceCacheKey: rootFSNamespacer.CacheKey(),
//.........这里部分代码省略.........

//.........这里部分代码省略.........
	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)

	// Configure and validate the kernels security support
	if err := configureKernelSecuritySupport(config, d.driver.String()); err != nil {
		return nil, err
	}

	daemonRepo := filepath.Join(config.Root, "containers")

	if err := idtools.MkdirAllAs(daemonRepo, 0700, rootUID, rootGID); err != nil && !os.IsExist(err) {
		return nil, err
	}

	// Migrate the container if it is aufs and aufs is enabled
	if err := migrateIfDownlevel(d.driver, config.Root); err != nil {
		return nil, err
	}

	logrus.Debug("Creating images graph")
	g, err := graph.NewGraph(filepath.Join(config.Root, "graph"), d.driver, uidMaps, gidMaps)
	if err != nil {
		return nil, err
	}

	// Configure the volumes driver
	volStore, err := configureVolumes(config, rootUID, rootGID)
	if err != nil {
		return nil, err
	}

	trustKey, err := api.LoadOrCreateTrustKey(config.TrustKeyPath)
	if err != nil {
		return nil, err
	}

	trustDir := filepath.Join(config.Root, "trust")

	if err := system.MkdirAll(trustDir, 0700); err != nil {
		return nil, err
	}

	eventsService := events.New()
	logrus.Debug("Creating repository list")
	tagCfg := &graph.TagStoreConfig{
		Graph:    g,
		Key:      trustKey,
		Registry: registryService,
		Events:   eventsService,
	}
	repositories, err := graph.NewTagStore(filepath.Join(config.Root, "repositories-"+d.driver.String()), tagCfg)
	if err != nil {
		return nil, fmt.Errorf("Couldn't create Tag store repositories-%s: %s", d.driver.String(), err)

func NewDaemon(config *Config, registryService *registry.Service) (daemon *Daemon, err error) {
	uidMaps, gidMaps, err := setupRemappedRoot(config)
	if err != nil {
		return nil, err
	}
	rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
	if err != nil {
		return nil, err
	}

	// 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)
		}
	}

	if err = setupDaemonRoot(config, realRoot, rootUID, rootGID); err != nil {
		return nil, err
	}

	// set up the tmpDir to use a canonical path
	tmp, err := tempDir(config.Root, rootUID, rootGID)
	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)

	// Load storage driver
	driver, err := graphdriver.New(config.Root, config.GraphOptions, uidMaps, gidMaps)
	if err != nil {
		return nil, fmt.Errorf("error initializing graphdriver: %v", err)
	}
	glog.V(1).Infof("Using graph driver %s", driver)

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

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

	daemonRepo := path.Join(config.Root, "containers")

	if err := os.MkdirAll(daemonRepo, 0700); err != nil && !os.IsExist(err) {
		glog.Error(err.Error())
		return nil, err
	}

	glog.Info("Creating images graph")
	g, err := graph.NewGraph(filepath.Join(config.Root, "graph"), d.driver, uidMaps, gidMaps)
	if err != nil {
		glog.Error(err.Error())
		return nil, err
	}

	// Configure the volumes driver
	volStore, err := configureVolumes(config, rootUID, rootGID)
	if err != nil {
		return nil, err
	}

	trustKey, err := api.LoadOrCreateTrustKey(config.TrustKeyPath)
	if err != nil {
		glog.Error(err.Error())
		return nil, err
	}

	trustDir := path.Join(config.Root, "trust")
	if err := os.MkdirAll(trustDir, 0700); err != nil && !os.IsExist(err) {
		glog.Error(err.Error())
		return nil, err
	}

	eventsService := events.New()
	glog.Info("Creating repository list")
	tagCfg := &graph.TagStoreConfig{
		Graph:    g,
		Key:      trustKey,
		Registry: registryService,
		Events:   eventsService,
	}
	repositories, err := graph.NewTagStore(path.Join(config.Root, "repositories-"+d.driver.String()), tagCfg)
	if err != nil {
		glog.Error(err.Error())
		return nil, fmt.Errorf("Couldn't create Tag store: %s", err)
	}

//.........这里部分代码省略.........

//.........这里部分代码省略.........

	dockerGraphDriver, err := selectGraphDriver(logger, *graphDriverName, *graphRoot)
	if err != nil {
		logger.Fatal("failed-to-construct-graph-driver", err)
	}

	backingStoresPath := filepath.Join(*graphRoot, "backing_stores")
	if err := os.MkdirAll(backingStoresPath, 0660); err != nil {
		logger.Fatal("failed-to-mkdir-backing-stores", err)
	}

	quotaedGraphDriver := &quotaed_aufs.QuotaedDriver{
		GraphDriver: dockerGraphDriver,
		Unmount:     quotaed_aufs.Unmount,
		BackingStoreMgr: &quotaed_aufs.BackingStore{
			RootPath: backingStoresPath,
			Logger:   logger.Session("backing-store-mgr"),
		},
		LoopMounter: &quotaed_aufs.Loop{
			Retrier: retrier.New(retrier.ConstantBackoff(200, 500*time.Millisecond), nil),
			Logger:  logger.Session("loop-mounter"),
		},
		Retrier:  retrier.New(retrier.ConstantBackoff(200, 500*time.Millisecond), nil),
		RootPath: *graphRoot,
		Logger:   logger.Session("quotaed-driver"),
	}

	metricsProvider := metrics.NewMetrics(logger, backingStoresPath, *depotPath)

	if dbgAddr := cf_debug_server.DebugAddress(flag.CommandLine); dbgAddr != "" {
		metrics.StartDebugServer(dbgAddr, reconfigurableSink, metricsProvider)
	}

	dockerGraph, err := graph.NewGraph(*graphRoot, quotaedGraphDriver)
	if err != nil {
		logger.Fatal("failed-to-construct-graph", err)
	}

	var cake layercake.Cake = &layercake.Docker{
		Graph:  dockerGraph,
		Driver: quotaedGraphDriver,
	}

	if cake.DriverName() == "aufs" {
		cake = &layercake.AufsCake{
			Cake:      cake,
			Runner:    runner,
			GraphRoot: *graphRoot,
		}
	}

	repo := container_repository.New()
	retainer := cleaner.NewRetainer()

	repoFetcher := &repository_fetcher.Retryable{
		RepositoryFetcher: &repository_fetcher.CompositeFetcher{
			LocalFetcher: &repository_fetcher.Local{
				Cake:              cake,
				DefaultRootFSPath: *rootFSPath,
				IDProvider:        repository_fetcher.LayerIDProvider{},
			},
			RemoteFetcher: repository_fetcher.NewRemote(
				logger,
				*dockerRegistry,
				cake,
				distclient.NewDialer(insecureRegistries.List),

		root   string
		driver graphdriver.Driver
		cake   *layercake.Docker
	)

	BeforeEach(func() {
		var err error

		root, err = ioutil.TempDir("", "cakeroot")
		Expect(err).NotTo(HaveOccurred())

		Expect(syscall.Mount("tmpfs", root, "tmpfs", 0, "")).To(Succeed())
		driver, err := graphdriver.GetDriver("vfs", root, nil)
		Expect(err).NotTo(HaveOccurred())

		graph, err := graph.NewGraph(root, driver)
		Expect(err).NotTo(HaveOccurred())

		cake = &layercake.Docker{
			Graph:  graph,
			Driver: driver,
		}
	})

	AfterEach(func() {
		Expect(syscall.Unmount(root, 0)).To(Succeed())
		Expect(os.RemoveAll(root)).To(Succeed())
	})

	Describe("Register", func() {
		Context("after registering a layer", func() {

func main() {
	if reexec.Init() {
		return
	}

	cf_debug_server.AddFlags(flag.CommandLine)
	cf_lager.AddFlags(flag.CommandLine)
	flag.Parse()

	runtime.GOMAXPROCS(runtime.NumCPU())

	logger, reconfigurableSink := cf_lager.New("garden-linux")
	if dbgAddr := cf_debug_server.DebugAddress(flag.CommandLine); dbgAddr != "" {
		debug.Run(dbgAddr, reconfigurableSink)
	}

	initializeDropsonde(logger)

	if *binPath == "" {
		missing("-bin")
	}

	if *depotPath == "" {
		missing("-depot")
	}

	if len(*tag) > 2 {
		println("-tag parameter must be less than 3 characters long")
		println()
		flag.Usage()
		return
	}

	_, dynamicRange, err := net.ParseCIDR(*networkPool)
	if err != nil {
		logger.Fatal("failed-to-parse-network-pool", err)
	}

	subnetPool, err := subnets.NewSubnets(dynamicRange)
	if err != nil {
		logger.Fatal("failed-to-create-subnet-pool", err)
	}

	// TODO: use /proc/sys/net/ipv4/ip_local_port_range by default (end + 1)
	portPool, err := port_pool.New(uint32(*portPoolStart), uint32(*portPoolSize))
	if err != nil {
		logger.Fatal("invalid pool range", err)
	}

	useKernelLogging := true
	switch *iptablesLogMethod {
	case "nflog":
		useKernelLogging = false
	case "kernel":
		/* noop */
	default:
		println("-iptablesLogMethod value not recognized")
		println()
		flag.Usage()
		return
	}

	config := sysconfig.NewConfig(*tag, *allowHostAccess)

	runner := sysconfig.NewRunner(config, linux_command_runner.New())

	if err := os.MkdirAll(*graphRoot, 0755); err != nil {
		logger.Fatal("failed-to-create-graph-directory", err)
	}

	dockerGraphDriver, err := graphdriver.New(*graphRoot, nil)
	if err != nil {
		logger.Fatal("failed-to-construct-graph-driver", err)
	}

	dockerGraph, err := graph.NewGraph(*graphRoot, dockerGraphDriver)
	if err != nil {
		logger.Fatal("failed-to-construct-graph", err)
	}

	graphMountPoint := mountPoint(logger, *graphRoot)

	var cake layercake.Cake = &layercake.Docker{
		Graph:  dockerGraph,
		Driver: dockerGraphDriver,
	}

	if cake.DriverName() == "btrfs" {
		cake = &layercake.BtrfsCleaningCake{
			Cake:            cake,
			Runner:          runner,
			BtrfsMountPoint: graphMountPoint,
			RemoveAll:       os.RemoveAll,
			Logger:          logger.Session("btrfs-cleanup"),
		}
	}

	retainer := layercake.NewRetainer()
	cake = &layercake.OvenCleaner{
		Cake:     cake,
//.........这里部分代码省略.........