func (daemon *Daemon) mountVolumes(container *Container) error {
	mounts, err := daemon.setupMounts(container)
	if err != nil {
		return err
	}

	for _, m := range mounts {
		dest, err := container.GetResourcePath(m.Destination)
		if err != nil {
			return err
		}

		var stat os.FileInfo
		stat, err = os.Stat(m.Source)
		if err != nil {
			return err
		}
		if err = fileutils.CreateIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}

		opts := "rbind,ro"
		if m.Writable {
			opts = "rbind,rw"
		}

		if err := mount.Mount(m.Source, dest, "bind", opts); err != nil {
			return err
		}
	}

	return nil
}

func bindMount(bindDir string, rootDir string, readonly bool) error {
	var srcDir, destDir string

	d := strings.SplitN(bindDir, ":", 2)
	if len(d) < 2 {
		srcDir = d[0]
	} else {
		srcDir, destDir = d[0], d[1]
	}
	if destDir == "" {
		destDir = srcDir
	}

	ok, err := osutil.IsDirEmpty(srcDir)
	if err != nil {
		return err
	}
	if ok {
		if _, err := os.Create(fp.Join(srcDir, ".droot.keep")); err != nil {
			return errwrap.Wrapf(err, "Failed to create .droot.keep: {{err}}")
		}
	}

	containerDir := fp.Join(rootDir, destDir)

	if err := fileutils.CreateIfNotExists(containerDir, true); err != nil { // mkdir -p
		return errwrap.Wrapff(err, "Failed to create directory: %s: {{err}}", containerDir)
	}

	ok, err = osutil.IsDirEmpty(containerDir)
	if err != nil {
		return err
	}
	if ok {
		log.Debug("bind mount", bindDir, "to", containerDir)
		if err := mount.Mount(srcDir, containerDir, "none", "bind,rw"); err != nil {
			return errwrap.Wrapff(err, "Failed to bind mount %s: {{err}}", containerDir)
		}

		if readonly {
			log.Debug("robind mount", bindDir, "to", containerDir)
			if err := mount.Mount(srcDir, containerDir, "none", "remount,ro,bind"); err != nil {
				return errwrap.Wrapff(err, "Failed to robind mount %s: {{err}}", containerDir)
			}
		}
	}

	return nil
}

// Atomic deploy by symlink
// 1. rsync maindir => backupdir
// 2. mv -T backuplink destdir
// 3. rsync srcdir => maindir
// 4. mv -T mainlink destdir
func DeployWithSymlink(srcDir, destDir string) error {
	mainLink := destDir + ".drootmain"
	backupLink := destDir + ".drootbackup"
	mainDir := destDir + ".d/main"
	backupDir := destDir + ".d/backup"

	for _, dir := range []string{mainDir, backupDir} {
		if err := fileutils.CreateIfNotExists(dir, true); err != nil { // mkdir -p
			return fmt.Errorf("Failed to create directory %s: %s", dir, err)
		}
	}

	// Return error if the working directory that droot internally uses exists
	for _, link := range []string{mainLink, backupLink, destDir} {
		if !osutil.IsSymlink(link) && (osutil.ExistsFile(link) || osutil.ExistsDir(link)) {
			return fmt.Errorf("%s already exists. Please use another directory as --dest option or delete %s", link, link)
		}
	}

	if err := osutil.Symlink(mainDir, mainLink); err != nil {
		return fmt.Errorf("Failed to create symlink %s: %s", mainLink, err)
	}
	if err := osutil.Symlink(backupDir, backupLink); err != nil {
		return fmt.Errorf("Failed to create symlink %s: %s", backupLink, err)
	}

	log.Info("-->", "Syncing", "from", mainDir, "to", backupDir)
	if err := Rsync(mainDir, backupDir); err != nil {
		return fmt.Errorf("Failed to rsync: %s", err)
	}

	log.Info("-->", "Renaming", "from", backupLink, "to", destDir)
	if err := os.Rename(backupLink, destDir); err != nil {
		return fmt.Errorf("Failed to rename %s: %s", destDir, err)
	}

	log.Info("-->", "Syncing", "from", srcDir, "to", mainDir)
	if err := Rsync(srcDir, mainDir); err != nil {
		return fmt.Errorf("Failed to rsync: %s", err)
	}

	log.Info("-->", "Renaming", "from", mainLink, "to", destDir)
	if err := os.Rename(mainLink, destDir); err != nil {
		return fmt.Errorf("Failed to rename %s: %s", destDir, err)
	}

	return nil
}

func (daemon *Daemon) mountVolumes(container *container.Container) error {
	mounts, err := daemon.setupMounts(container)
	if err != nil {
		return err
	}

	for _, m := range mounts {
		dest, err := container.GetResourcePath(m.Destination)
		if err != nil {
			return err
		}

		var stat os.FileInfo
		stat, err = os.Stat(m.Source)
		if err != nil {
			return err
		}
		if err = fileutils.CreateIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}

		opts := "rbind,ro"
		if m.Writable {
			opts = "rbind,rw"
		}

		if err := mount.Mount(m.Source, dest, bindMountType, opts); err != nil {
			return err
		}

		// mountVolumes() seems to be called for temporary mounts
		// outside the container. Soon these will be unmounted with
		// lazy unmount option and given we have mounted the rbind,
		// all the submounts will propagate if these are shared. If
		// daemon is running in host namespace and has / as shared
		// then these unmounts will propagate and unmount original
		// mount as well. So make all these mounts rprivate.
		// Do not use propagation property of volume as that should
		// apply only when mounting happen inside the container.
		if err := mount.MakeRPrivate(dest); err != nil {
			return err
		}
	}

	return nil
}

func (m *Mounter) BindMount(hostDir, containerDir string) error {
	containerDir = fp.Join(m.rootDir, containerDir)

	if ok := osutil.IsDirEmpty(hostDir); ok {
		if _, err := os.Create(fp.Join(hostDir, ".droot.keep")); err != nil {
			return err
		}
	}

	if err := fileutils.CreateIfNotExists(containerDir, true); err != nil { // mkdir -p
		return err
	}

	if err := osutil.MountIfNotMounted(hostDir, containerDir, "none", "bind,rw"); err != nil {
		return err
	}

	return nil
}

func (container *Container) Copy(resource string) (io.ReadCloser, error) {
	container.Lock()
	defer container.Unlock()
	var err error
	if err := container.Mount(); err != nil {
		return nil, err
	}
	defer func() {
		if err != nil {
			// unmount any volumes
			container.UnmountVolumes(true)
			// unmount the container's rootfs
			container.Unmount()
		}
	}()
	mounts, err := container.setupMounts()
	if err != nil {
		return nil, err
	}
	for _, m := range mounts {
		var dest string
		dest, err = container.GetResourcePath(m.Destination)
		if err != nil {
			return nil, err
		}
		var stat os.FileInfo
		stat, err = os.Stat(m.Source)
		if err != nil {
			return nil, err
		}
		if err = fileutils.CreateIfNotExists(dest, stat.IsDir()); err != nil {
			return nil, err
		}
		if err = mount.Mount(m.Source, dest, "bind", "rbind,ro"); err != nil {
			return nil, err
		}
	}
	basePath, err := container.GetResourcePath(resource)
	if err != nil {
		return nil, err
	}
	stat, err := os.Stat(basePath)
	if err != nil {
		return nil, err
	}
	var filter []string
	if !stat.IsDir() {
		d, f := filepath.Split(basePath)
		basePath = d
		filter = []string{f}
	} else {
		filter = []string{filepath.Base(basePath)}
		basePath = filepath.Dir(basePath)
	}
	archive, err := archive.TarWithOptions(basePath, &archive.TarOptions{
		Compression:  archive.Uncompressed,
		IncludeFiles: filter,
	})
	if err != nil {
		return nil, err
	}
	reader := ioutils.NewReadCloserWrapper(archive, func() error {
		err := archive.Close()
		container.UnmountVolumes(true)
		container.Unmount()
		return err
	})
	container.LogEvent("copy")
	return reader, nil
}