func rsyncMigrationSink(live bool, container container, snapshots []container, conn *websocket.Conn) error {
	/* the first object is the actual container */
	if err := RsyncRecv(shared.AddSlash(container.Path()), conn); err != nil {
		return err
	}

	if len(snapshots) > 0 {
		err := os.MkdirAll(shared.VarPath(fmt.Sprintf("snapshots/%s", container.Name())), 0700)
		if err != nil {
			return err
		}
	}

	for _, snap := range snapshots {
		if err := RsyncRecv(shared.AddSlash(snap.Path()), conn); err != nil {
			return err
		}
	}

	if live {
		/* now receive the final sync */
		if err := RsyncRecv(shared.AddSlash(container.Path()), conn); err != nil {
			return err
		}
	}

	return nil
}

func rsyncMigrationSink(container container, snapshots []container, conn *websocket.Conn) error {
	/* the first object is the actual container */
	if err := RsyncRecv(shared.AddSlash(container.Path()), conn); err != nil {
		return err
	}

	for _, snap := range snapshots {
		if err := RsyncRecv(shared.AddSlash(snap.Path()), conn); err != nil {
			return err
		}
	}

	return nil
}

func (s rsyncStorageSourceDriver) SendWhileRunning(conn *websocket.Conn) error {
	for _, send := range s.snapshots {
		if err := send.StorageStart(); err != nil {
			return err
		}
		defer send.StorageStop()

		path := send.Path()
		if err := RsyncSend(shared.AddSlash(path), conn); err != nil {
			return err
		}
	}

	return RsyncSend(shared.AddSlash(s.container.Path()), conn)
}

func (s rsyncStorageSourceDriver) SendWhileRunning(conn *websocket.Conn, op *operation) error {
	for _, send := range s.snapshots {
		if err := send.StorageStart(); err != nil {
			return err
		}
		defer send.StorageStop()

		path := send.Path()
		wrapper := StorageProgressReader(op, "fs_progress", send.Name())
		if err := RsyncSend(shared.AddSlash(path), conn, wrapper); err != nil {
			return err
		}
	}

	wrapper := StorageProgressReader(op, "fs_progress", s.container.Name())
	return RsyncSend(shared.AddSlash(s.container.Path()), conn, wrapper)
}

func (s rsyncStorageSourceDriver) SendWhileRunning(conn *websocket.Conn) error {
	toSend := append([]container{s.container}, s.snapshots...)

	for _, send := range toSend {
		path := send.Path()
		if err := RsyncSend(shared.AddSlash(path), conn); err != nil {
			return err
		}
	}

	return nil
}

// rsyncCopy copies a directory using rsync (with the --devices option).
func (ss *storageShared) rsyncCopy(source string, dest string) (string, error) {
	if err := os.MkdirAll(dest, 0755); err != nil {
		return "", err
	}

	output, err := exec.Command(
		"rsync",
		"-a",
		"--devices",
		shared.AddSlash(source),
		dest).CombinedOutput()

	return string(output), err
}

// storageRsyncCopy copies a directory using rsync (with the --devices option).
func storageRsyncCopy(source string, dest string) (string, error) {
	if err := os.MkdirAll(dest, 0755); err != nil {
		return "", err
	}

	rsyncVerbosity := "-q"
	if *debug {
		rsyncVerbosity = "-vi"
	}

	output, err := exec.Command(
		"rsync",
		"-a",
		"-HAX",
		"--devices",
		"--delete",
		rsyncVerbosity,
		shared.AddSlash(source),
		dest).CombinedOutput()

	return string(output), err
}

//.........这里部分代码省略.........
	}

	myType := s.container.Storage().MigrationType()
	header := MigrationHeader{
		Fs:        &myType,
		Criu:      criuType,
		Idmap:     idmaps,
		Snapshots: snapshots,
	}

	if err := s.send(&header); err != nil {
		s.sendControl(err)
		return err
	}

	if fsErr != nil {
		s.sendControl(fsErr)
		return fsErr
	}

	if err := s.recv(&header); err != nil {
		s.sendControl(err)
		return err
	}

	// TODO: actually fall back on rsync.
	if *header.Fs != myType {
		err := fmt.Errorf("mismatched storage types not supported yet")
		s.sendControl(err)
		return err
	}

	if s.live {
		if header.Criu == nil {
			err := fmt.Errorf("Got no CRIU socket type for live migration")
			s.sendControl(err)
			return err
		} else if *header.Criu != CRIUType_CRIU_RSYNC {
			err := fmt.Errorf("Formats other than criu rsync not understood")
			s.sendControl(err)
			return err
		}

		checkpointDir, err := ioutil.TempDir("", "lxd_checkpoint_")
		if err != nil {
			s.sendControl(err)
			return err
		}
		defer os.RemoveAll(checkpointDir)

		opts := lxc.CheckpointOptions{Stop: true, Directory: checkpointDir, Verbose: true}
		err = s.container.Checkpoint(opts)

		if err2 := CollectCRIULogFile(s.container, checkpointDir, "migration", "dump"); err2 != nil {
			shared.Debugf("Error collecting checkpoint log file %s", err)
		}

		if err != nil {
			log := GetCRIULogErrors(checkpointDir, "dump")

			err = fmt.Errorf("checkpoint failed:\n%s", log)
			s.sendControl(err)
			return err
		}

		/*
		 * We do the serially right now, but there's really no reason for us
		 * to; since we have separate websockets, we can do it in parallel if
		 * we wanted to. However, assuming we're network bound, there's really
		 * no reason to do these in parallel. In the future when we're using
		 * p.haul's protocol, it will make sense to do these in parallel.
		 */
		if err := RsyncSend(shared.AddSlash(checkpointDir), s.criuConn); err != nil {
			s.sendControl(err)
			return err
		}
	}

	for _, source := range sources {
		shared.Debugf("sending fs object %s", source.Name())
		if err := source.Send(s.fsConn); err != nil {
			s.sendControl(err)
			return err
		}
	}

	msg := MigrationControl{}
	if err := s.recv(&msg); err != nil {
		s.disconnect()
		return err
	}

	// TODO: should we add some config here about automatically restarting
	// the container migrate failure? What about the failures above?
	if !*msg.Success {
		return fmt.Errorf(*msg.Message)
	}

	return nil
}

//.........这里部分代码省略.........
						return fmt.Errorf("restore failed, failing CRIU")
					}
					return nil
				},
				nil,
				func(op *operation, r *http.Request, w http.ResponseWriter) error {
					secret := r.FormValue("secret")
					if secret == "" {
						return fmt.Errorf("missing secret")
					}

					if secret != actionScriptOpSecret {
						return os.ErrPermission
					}

					c, err := shared.WebsocketUpgrader.Upgrade(w, r, nil)
					if err != nil {
						return err
					}

					dumpDone <- true

					closeMsg := websocket.FormatCloseMessage(websocket.CloseNormalClosure, "")
					return c.WriteMessage(websocket.CloseMessage, closeMsg)
				},
			)
			if err != nil {
				os.RemoveAll(checkpointDir)
				return abort(err)
			}

			if err := writeActionScript(checkpointDir, actionScriptOp.url, actionScriptOpSecret); err != nil {
				os.RemoveAll(checkpointDir)
				return abort(err)
			}

			_, err = actionScriptOp.Run()
			if err != nil {
				os.RemoveAll(checkpointDir)
				return abort(err)
			}

			go func() {
				dumpSuccess <- s.container.Migrate(lxc.MIGRATE_DUMP, checkpointDir, "migration", true, true)
				os.RemoveAll(checkpointDir)
			}()

			select {
			/* the checkpoint failed, let's just abort */
			case err = <-dumpSuccess:
				return abort(err)
			/* the dump finished, let's continue on to the restore */
			case <-dumpDone:
				shared.LogDebugf("Dump finished, continuing with restore...")
			}
		} else {
			defer os.RemoveAll(checkpointDir)
			if err := s.container.Migrate(lxc.MIGRATE_DUMP, checkpointDir, "migration", true, false); err != nil {
				return abort(err)
			}
		}

		/*
		 * We do the serially right now, but there's really no reason for us
		 * to; since we have separate websockets, we can do it in parallel if
		 * we wanted to. However, assuming we're network bound, there's really
		 * no reason to do these in parallel. In the future when we're using
		 * p.haul's protocol, it will make sense to do these in parallel.
		 */
		if err := RsyncSend(shared.AddSlash(checkpointDir), s.criuConn, nil); err != nil {
			return abort(err)
		}

		if err := driver.SendAfterCheckpoint(s.fsConn); err != nil {
			return abort(err)
		}
	}

	driver.Cleanup()

	msg := MigrationControl{}
	if err := s.recv(&msg); err != nil {
		s.disconnect()
		return err
	}

	if s.live {
		restoreSuccess <- *msg.Success
		err := <-dumpSuccess
		if err != nil {
			shared.LogErrorf("dump failed after successful restore?: %q", err)
		}
	}

	if !*msg.Success {
		return fmt.Errorf(*msg.Message)
	}

	return nil
}

func (s rsyncStorageSourceDriver) SendAfterCheckpoint(conn *websocket.Conn) error {
	/* resync anything that changed between our first send and the checkpoint */
	return RsyncSend(shared.AddSlash(s.container.Path()), conn)
}

func containerSnapRestore(d *Daemon, name string, snap string) error {
	// normalize snapshot name
	if !shared.IsSnapshot(snap) {
		snap = fmt.Sprintf("%s/%s", name, snap)
	}

	shared.Debugf("RESTORE => Restoring snapshot [%s] on container [%s]", snap, name)
	/*
	 * restore steps:
	 * 1. stop container if already running
	 * 2. overwrite existing config with snapshot config
	 * 3. copy snapshot rootfs to container
	 */
	wasRunning := false
	c, err := newLxdContainer(name, d)

	if err != nil {
		shared.Debugf("RESTORE => Error: newLxdContainer() failed for container", err)
		return err
	}

	// 1. stop container
	// TODO: stateful restore ?
	if c.c.Running() {
		wasRunning = true
		if err = c.Stop(); err != nil {
			shared.Debugf("RESTORE => Error: could not stop container", err)
			return err
		}
		shared.Debugf("RESTORE => Stopped container %s", name)
	}

	// 2, replace config

	// Make sure the source exists.
	source, err := newLxdContainer(snap, d)
	if err != nil {
		shared.Debugf("RESTORE => Error: newLxdContainer() failed for snapshot", err)
		return err
	}

	newConfig := containerConfigReq{}
	newConfig.Config = source.config
	newConfig.Profiles = source.profiles
	newConfig.Devices = source.devices

	tx, err := containerReplaceConfig(d, c, name, newConfig)
	if err != nil {
		shared.Debugf("RESTORE => err #4", err)
		return err
	}
	if err := txCommit(tx); err != nil {
		return err
	}

	// 3. copy rootfs
	// TODO: btrfs optimizations

	containerRootPath := shared.VarPath("lxc", name)

	if !shared.IsDir(path.Dir(containerRootPath)) {
		shared.Debugf("RESTORE => containerRoot [%s] directory does not exist", containerRootPath)
		return os.ErrNotExist
	}

	var snapshotRootFSPath string
	snapshotRootFSPath = shared.AddSlash(snapshotRootfsDir(c, strings.SplitN(snap, "/", 2)[1]))

	containerRootFSPath := shared.AddSlash(fmt.Sprintf("%s/%s", containerRootPath, "rootfs"))
	shared.Debugf("RESTORE => Copying %s to %s", snapshotRootFSPath, containerRootFSPath)

	rsyncVerbosity := "-q"
	if *debug {
		rsyncVerbosity = "-vi"
	}

	output, err := exec.Command("rsync", "-a", "-c", "-HAX", "--devices", "--delete", rsyncVerbosity, snapshotRootFSPath, containerRootFSPath).CombinedOutput()
	shared.Debugf("RESTORE => rsync output\n%s", output)

	if err == nil && !source.isPrivileged() {
		err = setUnprivUserAcl(c, containerRootPath)
		if err != nil {
			shared.Debugf("Error adding acl for container root: falling back to chmod\n")
			output, err := exec.Command("chmod", "+x", containerRootPath).CombinedOutput()
			if err != nil {
				shared.Debugf("Error chmoding the container root\n")
				shared.Debugf(string(output))
				return err
			}
		}
	} else {
		shared.Debugf("rsync failed:\n%s", output)
		return err
	}

	if wasRunning {
		c.Start()
	}

	return nil
//.........这里部分代码省略.........

func (c *migrationSink) do() error {
	var err error
	c.controlConn, err = c.connectWithSecret(c.controlSecret)
	if err != nil {
		return err
	}
	defer c.disconnect()

	c.fsConn, err = c.connectWithSecret(c.fsSecret)
	if err != nil {
		c.sendControl(err)
		return err
	}

	if c.live {
		c.criuConn, err = c.connectWithSecret(c.criuSecret)
		if err != nil {
			c.sendControl(err)
			return err
		}
	}

	// For now, we just ignore whatever the server sends us. We only
	// support RSYNC, so that's what we respond with.
	header := MigrationHeader{}
	if err := c.recv(&header); err != nil {
		c.sendControl(err)
		return err
	}

	criuType := CRIUType_CRIU_RSYNC.Enum()
	if !c.live {
		criuType = nil
	}

	resp := MigrationHeader{Fs: MigrationFSType_RSYNC.Enum(), Criu: criuType}
	if err := c.send(&resp); err != nil {
		c.sendControl(err)
		return err
	}

	restore := make(chan error)
	go func(c *migrationSink) {
		imagesDir := ""
		srcIdmap := new(shared.IdmapSet)
		dstIdmap := c.IdmapSet

		if dstIdmap == nil {
			dstIdmap = new(shared.IdmapSet)
		}

		if c.live {
			var err error
			imagesDir, err = ioutil.TempDir("", "lxd_migration_")
			if err != nil {
				os.RemoveAll(imagesDir)
				c.sendControl(err)
				return
			}

			defer func() {
				err := CollectCRIULogFile(c.container, imagesDir, "migration", "restore")
				/*
				 * If the checkpoint fails, we won't have any log to collect,
				 * so don't warn about that.
				 */
				if err != nil && !os.IsNotExist(err) {
					shared.Debugf("Error collectiong migration log file %s", err)
				}

				os.RemoveAll(imagesDir)
			}()

			if err := RsyncRecv(shared.AddSlash(imagesDir), c.criuConn); err != nil {
				restore <- err
				os.RemoveAll(imagesDir)
				c.sendControl(err)
				return
			}

			/*
			 * For unprivileged containers we need to shift the
			 * perms on the images images so that they can be
			 * opened by the process after it is in its user
			 * namespace.
			 */
			if dstIdmap != nil {
				if err := dstIdmap.ShiftRootfs(imagesDir); err != nil {
					restore <- err
					os.RemoveAll(imagesDir)
					c.sendControl(err)
					return
				}
			}
		}

		fsDir := c.container.ConfigItem("lxc.rootfs")[0]
		if err := RsyncRecv(shared.AddSlash(fsDir), c.fsConn); err != nil {
			restore <- err
			c.sendControl(err)
//.........这里部分代码省略.........

func (s *migrationSourceWs) Do() shared.OperationResult {
	<-s.allConnected

	criuType := CRIUType_CRIU_RSYNC.Enum()
	if !s.live {
		criuType = nil
	}

	idmaps := make([]*IDMapType, 0)

	if s.idmapset != nil {
		for _, ctnIdmap := range s.idmapset.Idmap {
			idmap := IDMapType{
				Isuid:    proto.Bool(ctnIdmap.Isuid),
				Isgid:    proto.Bool(ctnIdmap.Isgid),
				Hostid:   proto.Int(ctnIdmap.Hostid),
				Nsid:     proto.Int(ctnIdmap.Nsid),
				Maprange: proto.Int(ctnIdmap.Maprange),
			}

			idmaps = append(idmaps, &idmap)
		}
	}

	header := MigrationHeader{
		Fs:    MigrationFSType_RSYNC.Enum(),
		Criu:  criuType,
		Idmap: idmaps,
	}

	if err := s.send(&header); err != nil {
		s.sendControl(err)
		return shared.OperationError(err)
	}

	if err := s.recv(&header); err != nil {
		s.sendControl(err)
		return shared.OperationError(err)
	}

	if *header.Fs != MigrationFSType_RSYNC {
		err := fmt.Errorf("Formats other than rsync not understood")
		s.sendControl(err)
		return shared.OperationError(err)
	}

	if s.live {
		if header.Criu == nil {
			err := fmt.Errorf("Got no CRIU socket type for live migration")
			s.sendControl(err)
			return shared.OperationError(err)
		} else if *header.Criu != CRIUType_CRIU_RSYNC {
			err := fmt.Errorf("Formats other than criu rsync not understood")
			s.sendControl(err)
			return shared.OperationError(err)
		}

		checkpointDir, err := ioutil.TempDir("", "lxd_migration_")
		if err != nil {
			s.sendControl(err)
			return shared.OperationError(err)
		}
		defer os.RemoveAll(checkpointDir)

		opts := lxc.CheckpointOptions{Stop: true, Directory: checkpointDir, Verbose: true}
		err = s.container.Checkpoint(opts)

		if err2 := CollectCRIULogFile(s.container, checkpointDir, "migration", "dump"); err2 != nil {
			shared.Debugf("Error collecting checkpoint log file %s", err)
		}

		if err != nil {
			log := GetCRIULogErrors(checkpointDir, "dump")

			err = fmt.Errorf("checkpoint failed:\n%s", log)
			s.sendControl(err)
			return shared.OperationError(err)
		}

		/*
		 * We do the serially right now, but there's really no reason for us
		 * to; since we have separate websockets, we can do it in parallel if
		 * we wanted to. However, assuming we're network bound, there's really
		 * no reason to do these in parallel. In the future when we're using
		 * p.haul's protocol, it will make sense to do these in parallel.
		 */
		if err := RsyncSend(shared.AddSlash(checkpointDir), s.criuConn); err != nil {
			s.sendControl(err)
			return shared.OperationError(err)
		}
	}

	fsDir := s.container.ConfigItem("lxc.rootfs")[0]
	if err := RsyncSend(shared.AddSlash(fsDir), s.fsConn); err != nil {
		s.sendControl(err)
		return shared.OperationError(err)
	}

	msg := MigrationControl{}
	if err := s.recv(&msg); err != nil {
//.........这里部分代码省略.........

func containerSnapshotsPost(d *Daemon, r *http.Request) Response {
	name := mux.Vars(r)["name"]

	/*
	 * snapshot is a three step operation:
	 * 1. choose a new name
	 * 2. copy the database info over
	 * 3. copy over the rootfs
	 */
	c, err := newLxdContainer(name, d)
	if err != nil {
		return SmartError(err)
	}

	raw := shared.Jmap{}
	if err := json.NewDecoder(r.Body).Decode(&raw); err != nil {
		return BadRequest(err)
	}

	snapshotName, err := raw.GetString("name")
	if err != nil || snapshotName == "" {
		// come up with a name
		i := nextSnapshot(d, name)
		snapshotName = fmt.Sprintf("snap%d", i)
	}

	stateful, err := raw.GetBool("stateful")
	if err != nil {
		return BadRequest(err)
	}

	fullName := fmt.Sprintf("%s/%s", name, snapshotName)
	snapDir := snapshotDir(c, snapshotName)
	if shared.PathExists(snapDir) {
		shared.Log.Error(
			"Snapshot exists on disk",
			log.Ctx{
				"name": fullName,
				"path": snapDir})
		return Conflict
	}

	err = os.MkdirAll(snapDir, 0700)
	if err != nil {
		return InternalError(err)
	}

	snapshot := func() error {

		StateDir := snapshotStateDir(c, snapshotName)
		err = os.MkdirAll(StateDir, 0700)
		if err != nil {
			os.RemoveAll(snapDir)
			return err
		}

		if stateful {
			// TODO - shouldn't we freeze for the duration of rootfs snapshot below?
			if !c.c.Running() {
				os.RemoveAll(snapDir)
				return fmt.Errorf("Container not running\n")
			}
			opts := lxc.CheckpointOptions{Directory: StateDir, Stop: true, Verbose: true}
			if err := c.c.Checkpoint(opts); err != nil {
				os.RemoveAll(snapDir)
				return err
			}
		}

		/* Create the db info */
		args := containerLXDArgs{
			Ctype:        cTypeSnapshot,
			Config:       c.config,
			Profiles:     c.profiles,
			Ephemeral:    c.ephemeral,
			BaseImage:    c.config["volatile.baseImage"],
			Architecture: c.architecture,
		}

		_, err := dbContainerCreate(d.db, fullName, args)
		if err != nil {
			os.RemoveAll(snapDir)
			return err
		}

		/* Create the directory and rootfs, set perms */
		/* Copy the rootfs */
		oldPath := shared.AddSlash(shared.VarPath("containers", name, "rootfs"))
		newPath := snapshotRootfsDir(c, snapshotName)
		err = exec.Command("rsync", "-a", "--devices", oldPath, newPath).Run()
		if err != nil {
			os.RemoveAll(snapDir)
			dbContainerSnapshotRemove(d.db, name, snapshotName)
		}
		return err
	}

	return AsyncResponse(shared.OperationWrap(snapshot), nil)
}

//.........这里部分代码省略.........
		s.sendControl(err)
		return err
	}

	if fsErr != nil {
		s.sendControl(fsErr)
		return fsErr
	}

	if err := s.recv(&header); err != nil {
		s.sendControl(err)
		return err
	}

	if *header.Fs != myType {
		myType = MigrationFSType_RSYNC
		header.Fs = &myType

		driver, _ = rsyncMigrationSource(s.container)
	}

	defer driver.Cleanup()

	if err := driver.SendWhileRunning(s.fsConn); err != nil {
		s.sendControl(err)
		return err
	}

	if s.live {
		if header.Criu == nil {
			err := fmt.Errorf("Got no CRIU socket type for live migration")
			s.sendControl(err)
			return err
		} else if *header.Criu != CRIUType_CRIU_RSYNC {
			err := fmt.Errorf("Formats other than criu rsync not understood")
			s.sendControl(err)
			return err
		}

		checkpointDir, err := ioutil.TempDir("", "lxd_checkpoint_")
		if err != nil {
			s.sendControl(err)
			return err
		}
		defer os.RemoveAll(checkpointDir)

		opts := lxc.CheckpointOptions{Stop: true, Directory: checkpointDir, Verbose: true}
		err = s.container.Checkpoint(opts)

		if err2 := CollectCRIULogFile(s.container, checkpointDir, "migration", "dump"); err2 != nil {
			shared.Debugf("Error collecting checkpoint log file %s", err)
		}

		if err != nil {
			log, err2 := GetCRIULogErrors(checkpointDir, "dump")

			/* couldn't find the CRIU log file which means we
			 * didn't even get that far; give back the liblxc
			 * error. */
			if err2 != nil {
				log = err.Error()
			}

			err = fmt.Errorf("checkpoint failed:\n%s", log)
			s.sendControl(err)
			return err
		}

		/*
		 * We do the serially right now, but there's really no reason for us
		 * to; since we have separate websockets, we can do it in parallel if
		 * we wanted to. However, assuming we're network bound, there's really
		 * no reason to do these in parallel. In the future when we're using
		 * p.haul's protocol, it will make sense to do these in parallel.
		 */
		if err := RsyncSend(shared.AddSlash(checkpointDir), s.criuConn); err != nil {
			s.sendControl(err)
			return err
		}

		if err := driver.SendAfterCheckpoint(s.fsConn); err != nil {
			s.sendControl(err)
			return err
		}
	}

	msg := MigrationControl{}
	if err := s.recv(&msg); err != nil {
		s.disconnect()
		return err
	}

	// TODO: should we add some config here about automatically restarting
	// the container migrate failure? What about the failures above?
	if !*msg.Success {
		return fmt.Errorf(*msg.Message)
	}

	return nil
}

func (s *rsyncStorageSource) Send(conn *websocket.Conn) error {
	path := s.container.Path()
	return RsyncSend(shared.AddSlash(path), conn)
}

func TestRsyncSendRecv(t *testing.T) {
	source, err := ioutil.TempDir("", "lxd_test_source_")
	if err != nil {
		t.Error(err)
		return
	}
	defer os.RemoveAll(source)

	sink, err := ioutil.TempDir("", "lxd_test_sink_")
	if err != nil {
		t.Error(err)
		return
	}
	defer os.RemoveAll(sink)

	/* now, write something to rsync over */
	f, err := os.Create(path.Join(source, "foo"))
	if err != nil {
		t.Error(err)
		return
	}
	f.Write([]byte(helloWorld))
	f.Close()

	send, sendConn, _, err := rsyncSendSetup(shared.AddSlash(source))
	if err != nil {
		t.Error(err)
		return
	}

	recv := rsyncRecvCmd(sink)

	recvOut, err := recv.StdoutPipe()
	if err != nil {
		t.Error(err)
		return
	}

	recvIn, err := recv.StdinPipe()
	if err != nil {
		t.Error(err)
		return
	}

	if err := recv.Start(); err != nil {
		t.Error(err)
		return
	}

	go func() {
		defer sendConn.Close()
		if _, err := io.Copy(sendConn, recvOut); err != nil {
			t.Error(err)
		}

		if err := recv.Wait(); err != nil {
			t.Error(err)
		}

	}()

	/*
	 * We close the socket in the above gofunc, but go tells us
	 * https://github.com/golang/go/issues/4373 that this is an error
	 * because we were reading from a socket that was closed. Thus, we
	 * ignore it
	 */
	io.Copy(recvIn, sendConn)

	if err := send.Wait(); err != nil {
		t.Error(err)
		return
	}

	f, err = os.Open(path.Join(sink, "foo"))
	if err != nil {
		t.Error(err)
		return
	}
	defer f.Close()

	buf, err := ioutil.ReadAll(f)
	if err != nil {
		t.Error(err)
		return
	}

	if string(buf) != helloWorld {
		t.Errorf("expected %s got %s", helloWorld, buf)
		return
	}
}

func rsyncMigrationSink(live bool, container container, snapshots []*Snapshot, conn *websocket.Conn, srcIdmap *shared.IdmapSet, op *operation) error {
	isDirBackend := container.Storage().GetStorageType() == storageTypeDir

	if isDirBackend {
		if len(snapshots) > 0 {
			err := os.MkdirAll(shared.VarPath(fmt.Sprintf("snapshots/%s", container.Name())), 0700)
			if err != nil {
				return err
			}
		}
		for _, snap := range snapshots {
			args := snapshotProtobufToContainerArgs(container.Name(), snap)
			s, err := containerCreateEmptySnapshot(container.Daemon(), args)
			if err != nil {
				return err
			}

			wrapper := StorageProgressWriter(op, "fs_progress", s.Name())
			if err := RsyncRecv(shared.AddSlash(s.Path()), conn, wrapper); err != nil {
				return err
			}

			if err := ShiftIfNecessary(container, srcIdmap); err != nil {
				return err
			}
		}

		wrapper := StorageProgressWriter(op, "fs_progress", container.Name())
		if err := RsyncRecv(shared.AddSlash(container.Path()), conn, wrapper); err != nil {
			return err
		}
	} else {
		if err := container.StorageStart(); err != nil {
			return err
		}
		defer container.StorageStop()

		for _, snap := range snapshots {
			args := snapshotProtobufToContainerArgs(container.Name(), snap)
			wrapper := StorageProgressWriter(op, "fs_progress", snap.GetName())
			if err := RsyncRecv(shared.AddSlash(container.Path()), conn, wrapper); err != nil {
				return err
			}

			if err := ShiftIfNecessary(container, srcIdmap); err != nil {
				return err
			}

			_, err := containerCreateAsSnapshot(container.Daemon(), args, container)
			if err != nil {
				return err
			}
		}

		wrapper := StorageProgressWriter(op, "fs_progress", container.Name())
		if err := RsyncRecv(shared.AddSlash(container.Path()), conn, wrapper); err != nil {
			return err
		}
	}

	if live {
		/* now receive the final sync */
		wrapper := StorageProgressWriter(op, "fs_progress", container.Name())
		if err := RsyncRecv(shared.AddSlash(container.Path()), conn, wrapper); err != nil {
			return err
		}
	}

	if err := ShiftIfNecessary(container, srcIdmap); err != nil {
		return err
	}

	return nil
}

//.........这里部分代码省略.........
				fsTransfer <- err
				return
			}

			if err := ShiftIfNecessary(c.container, srcIdmap); err != nil {
				fsTransfer <- err
				return
			}

			fsTransfer <- nil
		}()

		if c.live {
			var err error
			imagesDir, err = ioutil.TempDir("", "lxd_restore_")
			if err != nil {
				os.RemoveAll(imagesDir)
				return
			}

			defer func() {
				err := CollectCRIULogFile(c.container, imagesDir, "migration", "restore")
				/*
				 * If the checkpoint fails, we won't have any log to collect,
				 * so don't warn about that.
				 */
				if err != nil && !os.IsNotExist(err) {
					shared.Debugf("Error collectiong migration log file %s", err)
				}

				os.RemoveAll(imagesDir)
			}()

			if err := RsyncRecv(shared.AddSlash(imagesDir), c.criuConn); err != nil {
				restore <- err
				return
			}

			/*
			 * For unprivileged containers we need to shift the
			 * perms on the images images so that they can be
			 * opened by the process after it is in its user
			 * namespace.
			 */
			if !c.container.IsPrivileged() {
				if err := c.container.IdmapSet().ShiftRootfs(imagesDir); err != nil {
					restore <- err
					return
				}
			}
		}

		err := <-fsTransfer
		if err != nil {
			restore <- err
			return
		}

		if c.live {
			err := c.container.StartFromMigration(imagesDir)
			if err != nil {
				log, err2 := GetCRIULogErrors(imagesDir, "restore")
				/* restore failed before CRIU was invoked, give
				 * back the liblxc error */
				if err2 != nil {
					log = err.Error()

func (c *migrationSink) do() error {
	var err error
	c.controlConn, err = c.connectWithSecret(c.controlSecret)
	if err != nil {
		return err
	}
	defer c.disconnect()

	c.fsConn, err = c.connectWithSecret(c.fsSecret)
	if err != nil {
		c.sendControl(err)
		return err
	}

	if c.live {
		c.criuConn, err = c.connectWithSecret(c.criuSecret)
		if err != nil {
			c.sendControl(err)
			return err
		}
	}

	// For now, we just ignore whatever the server sends us. We only
	// support RSYNC, so that's what we respond with.
	header := MigrationHeader{}
	if err := c.recv(&header); err != nil {
		c.sendControl(err)
		return err
	}

	criuType := CRIUType_CRIU_RSYNC.Enum()
	if !c.live {
		criuType = nil
	}

	resp := MigrationHeader{Fs: MigrationFSType_RSYNC.Enum(), Criu: criuType}
	if err := c.send(&resp); err != nil {
		c.sendControl(err)
		return err
	}

	restore := make(chan error)
	go func(c *migrationSink) {
		imagesDir := ""
		if c.live {
			var err error
			imagesDir, err = ioutil.TempDir("", "lxd_migration_")
			if err != nil {
				os.RemoveAll(imagesDir)
				c.sendControl(err)
				return
			}

			defer func() {
				err := collectMigrationLogFile(c.container, imagesDir, "restore")
				/*
				 * If the checkpoint fails, we won't have any log to collect,
				 * so don't warn about that.
				 */
				if err != nil && !os.IsNotExist(err) {
					shared.Debugf("error collectiong migration log file %s", err)
				}

				os.RemoveAll(imagesDir)
			}()

			if err := RsyncRecv(shared.AddSlash(imagesDir), c.criuConn); err != nil {
				restore <- err
				os.RemoveAll(imagesDir)
				c.sendControl(err)
				return
			}
		}

		fsDir := c.container.ConfigItem("lxc.rootfs")[0]
		if err := RsyncRecv(shared.AddSlash(fsDir), c.fsConn); err != nil {
			restore <- err
			c.sendControl(err)
			return
		}

		if c.IdmapSet != nil {
			if err := c.IdmapSet.ShiftRootfs(shared.VarPath("containers", c.container.Name())); err != nil {
				restore <- err
				c.sendControl(err)
				return
			}
		}

		if c.live {
			f, err := ioutil.TempFile("", "lxd_lxc_migrateconfig_")
			if err != nil {
				restore <- err
				return
			}

			if err = f.Chmod(0600); err != nil {
				f.Close()
				os.Remove(f.Name())
				return
//.........这里部分代码省略.........