1 files changed, 815 insertions, 0 deletions
diff --git a/vendor/github.com/Microsoft/hcsshim/internal/wclayer/legacy.go b/vendor/github.com/Microsoft/hcsshim/internal/wclayer/legacy.go
new file mode 100644
index 000000000..b8ea5d263
--- /dev/null
+++ b/vendor/github.com/Microsoft/hcsshim/internal/wclayer/legacy.go
@@ -0,0 +1,815 @@
+package wclayer
+
+import (
+	"bufio"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/hcsshim/internal/longpath"
+	"github.com/Microsoft/hcsshim/internal/safefile"
+)
+
+var errorIterationCanceled = errors.New("")
+
+var mutatedUtilityVMFiles = map[string]bool{
+	`EFI\Microsoft\Boot\BCD`:      true,
+	`EFI\Microsoft\Boot\BCD.LOG`:  true,
+	`EFI\Microsoft\Boot\BCD.LOG1`: true,
+	`EFI\Microsoft\Boot\BCD.LOG2`: true,
+}
+
+const (
+	filesPath          = `Files`
+	hivesPath          = `Hives`
+	utilityVMPath      = `UtilityVM`
+	utilityVMFilesPath = `UtilityVM\Files`
+)
+
+func openFileOrDir(path string, mode uint32, createDisposition uint32) (file *os.File, err error) {
+	return winio.OpenForBackup(path, mode, syscall.FILE_SHARE_READ, createDisposition)
+}
+
+func hasPathPrefix(p, prefix string) bool {
+	return strings.HasPrefix(p, prefix) && len(p) > len(prefix) && p[len(prefix)] == '\\'
+}
+
+type fileEntry struct {
+	path string
+	fi   os.FileInfo
+	err  error
+}
+
+type legacyLayerReader struct {
+	root         string
+	result       chan *fileEntry
+	proceed      chan bool
+	currentFile  *os.File
+	backupReader *winio.BackupFileReader
+}
+
+// newLegacyLayerReader returns a new LayerReader that can read the Windows
+// container layer transport format from disk.
+func newLegacyLayerReader(root string) *legacyLayerReader {
+	r := &legacyLayerReader{
+		root:    root,
+		result:  make(chan *fileEntry),
+		proceed: make(chan bool),
+	}
+	go r.walk()
+	return r
+}
+
+func readTombstones(path string) (map[string]([]string), error) {
+	tf, err := os.Open(filepath.Join(path, "tombstones.txt"))
+	if err != nil {
+		return nil, err
+	}
+	defer tf.Close()
+	s := bufio.NewScanner(tf)
+	if !s.Scan() || s.Text() != "\xef\xbb\xbfVersion 1.0" {
+		return nil, errors.New("Invalid tombstones file")
+	}
+
+	ts := make(map[string]([]string))
+	for s.Scan() {
+		t := filepath.Join(filesPath, s.Text()[1:]) // skip leading `\`
+		dir := filepath.Dir(t)
+		ts[dir] = append(ts[dir], t)
+	}
+	if err = s.Err(); err != nil {
+		return nil, err
+	}
+
+	return ts, nil
+}
+
+func (r *legacyLayerReader) walkUntilCancelled() error {
+	root, err := longpath.LongAbs(r.root)
+	if err != nil {
+		return err
+	}
+
+	r.root = root
+	ts, err := readTombstones(r.root)
+	if err != nil {
+		return err
+	}
+
+	err = filepath.Walk(r.root, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Indirect fix for https://github.com/moby/moby/issues/32838#issuecomment-343610048.
+		// Handle failure from what may be a golang bug in the conversion of
+		// UTF16 to UTF8 in files which are left in the recycle bin. Os.Lstat
+		// which is called by filepath.Walk will fail when a filename contains
+		// unicode characters. Skip the recycle bin regardless which is goodness.
+		if strings.EqualFold(path, filepath.Join(r.root, `Files\$Recycle.Bin`)) && info.IsDir() {
+			return filepath.SkipDir
+		}
+
+		if path == r.root || path == filepath.Join(r.root, "tombstones.txt") || strings.HasSuffix(path, ".$wcidirs$") {
+			return nil
+		}
+
+		r.result <- &fileEntry{path, info, nil}
+		if !<-r.proceed {
+			return errorIterationCanceled
+		}
+
+		// List all the tombstones.
+		if info.IsDir() {
+			relPath, err := filepath.Rel(r.root, path)
+			if err != nil {
+				return err
+			}
+			if dts, ok := ts[relPath]; ok {
+				for _, t := range dts {
+					r.result <- &fileEntry{filepath.Join(r.root, t), nil, nil}
+					if !<-r.proceed {
+						return errorIterationCanceled
+					}
+				}
+			}
+		}
+		return nil
+	})
+	if err == errorIterationCanceled {
+		return nil
+	}
+	if err == nil {
+		return io.EOF
+	}
+	return err
+}
+
+func (r *legacyLayerReader) walk() {
+	defer close(r.result)
+	if !<-r.proceed {
+		return
+	}
+
+	err := r.walkUntilCancelled()
+	if err != nil {
+		for {
+			r.result <- &fileEntry{err: err}
+			if !<-r.proceed {
+				return
+			}
+		}
+	}
+}
+
+func (r *legacyLayerReader) reset() {
+	if r.backupReader != nil {
+		r.backupReader.Close()
+		r.backupReader = nil
+	}
+	if r.currentFile != nil {
+		r.currentFile.Close()
+		r.currentFile = nil
+	}
+}
+
+func findBackupStreamSize(r io.Reader) (int64, error) {
+	br := winio.NewBackupStreamReader(r)
+	for {
+		hdr, err := br.Next()
+		if err != nil {
+			if err == io.EOF {
+				err = nil
+			}
+			return 0, err
+		}
+		if hdr.Id == winio.BackupData {
+			return hdr.Size, nil
+		}
+	}
+}
+
+func (r *legacyLayerReader) Next() (path string, size int64, fileInfo *winio.FileBasicInfo, err error) {
+	r.reset()
+	r.proceed <- true
+	fe := <-r.result
+	if fe == nil {
+		err = errors.New("LegacyLayerReader closed")
+		return
+	}
+	if fe.err != nil {
+		err = fe.err
+		return
+	}
+
+	path, err = filepath.Rel(r.root, fe.path)
+	if err != nil {
+		return
+	}
+
+	if fe.fi == nil {
+		// This is a tombstone. Return a nil fileInfo.
+		return
+	}
+
+	if fe.fi.IsDir() && hasPathPrefix(path, filesPath) {
+		fe.path += ".$wcidirs$"
+	}
+
+	f, err := openFileOrDir(fe.path, syscall.GENERIC_READ, syscall.OPEN_EXISTING)
+	if err != nil {
+		return
+	}
+	defer func() {
+		if f != nil {
+			f.Close()
+		}
+	}()
+
+	fileInfo, err = winio.GetFileBasicInfo(f)
+	if err != nil {
+		return
+	}
+
+	if !hasPathPrefix(path, filesPath) {
+		size = fe.fi.Size()
+		r.backupReader = winio.NewBackupFileReader(f, false)
+		if path == hivesPath || path == filesPath {
+			// The Hives directory has a non-deterministic file time because of the
+			// nature of the import process. Use the times from System_Delta.
+			var g *os.File
+			g, err = os.Open(filepath.Join(r.root, hivesPath, `System_Delta`))
+			if err != nil {
+				return
+			}
+			attr := fileInfo.FileAttributes
+			fileInfo, err = winio.GetFileBasicInfo(g)
+			g.Close()
+			if err != nil {
+				return
+			}
+			fileInfo.FileAttributes = attr
+		}
+
+		// The creation time and access time get reset for files outside of the Files path.
+		fileInfo.CreationTime = fileInfo.LastWriteTime
+		fileInfo.LastAccessTime = fileInfo.LastWriteTime
+
+	} else {
+		// The file attributes are written before the backup stream.
+		var attr uint32
+		err = binary.Read(f, binary.LittleEndian, &attr)
+		if err != nil {
+			return
+		}
+		fileInfo.FileAttributes = attr
+		beginning := int64(4)
+
+		// Find the accurate file size.
+		if !fe.fi.IsDir() {
+			size, err = findBackupStreamSize(f)
+			if err != nil {
+				err = &os.PathError{Op: "findBackupStreamSize", Path: fe.path, Err: err}
+				return
+			}
+		}
+
+		// Return back to the beginning of the backup stream.
+		_, err = f.Seek(beginning, 0)
+		if err != nil {
+			return
+		}
+	}
+
+	r.currentFile = f
+	f = nil
+	return
+}
+
+func (r *legacyLayerReader) Read(b []byte) (int, error) {
+	if r.backupReader == nil {
+		if r.currentFile == nil {
+			return 0, io.EOF
+		}
+		return r.currentFile.Read(b)
+	}
+	return r.backupReader.Read(b)
+}
+
+func (r *legacyLayerReader) Seek(offset int64, whence int) (int64, error) {
+	if r.backupReader == nil {
+		if r.currentFile == nil {
+			return 0, errors.New("no current file")
+		}
+		return r.currentFile.Seek(offset, whence)
+	}
+	return 0, errors.New("seek not supported on this stream")
+}
+
+func (r *legacyLayerReader) Close() error {
+	r.proceed <- false
+	<-r.result
+	r.reset()
+	return nil
+}
+
+type pendingLink struct {
+	Path, Target string
+	TargetRoot   *os.File
+}
+
+type pendingDir struct {
+	Path string
+	Root *os.File
+}
+
+type legacyLayerWriter struct {
+	root            *os.File
+	destRoot        *os.File
+	parentRoots     []*os.File
+	currentFile     *os.File
+	bufWriter       *bufio.Writer
+	currentFileName string
+	currentFileRoot *os.File
+	backupWriter    *winio.BackupFileWriter
+	Tombstones      []string
+	HasUtilityVM    bool
+	uvmDi           []dirInfo
+	addedFiles      map[string]bool
+	PendingLinks    []pendingLink
+	pendingDirs     []pendingDir
+	currentIsDir    bool
+}
+
+// newLegacyLayerWriter returns a LayerWriter that can write the contaler layer
+// transport format to disk.
+func newLegacyLayerWriter(root string, parentRoots []string, destRoot string) (w *legacyLayerWriter, err error) {
+	w = &legacyLayerWriter{
+		addedFiles: make(map[string]bool),
+	}
+	defer func() {
+		if err != nil {
+			w.CloseRoots()
+			w = nil
+		}
+	}()
+	w.root, err = safefile.OpenRoot(root)
+	if err != nil {
+		return
+	}
+	w.destRoot, err = safefile.OpenRoot(destRoot)
+	if err != nil {
+		return
+	}
+	for _, r := range parentRoots {
+		f, err := safefile.OpenRoot(r)
+		if err != nil {
+			return w, err
+		}
+		w.parentRoots = append(w.parentRoots, f)
+	}
+	w.bufWriter = bufio.NewWriterSize(ioutil.Discard, 65536)
+	return
+}
+
+func (w *legacyLayerWriter) CloseRoots() {
+	if w.root != nil {
+		w.root.Close()
+		w.root = nil
+	}
+	if w.destRoot != nil {
+		w.destRoot.Close()
+		w.destRoot = nil
+	}
+	for i := range w.parentRoots {
+		w.parentRoots[i].Close()
+	}
+	w.parentRoots = nil
+}
+
+func (w *legacyLayerWriter) initUtilityVM() error {
+	if !w.HasUtilityVM {
+		err := safefile.MkdirRelative(utilityVMPath, w.destRoot)
+		if err != nil {
+			return err
+		}
+		// Server 2016 does not support multiple layers for the utility VM, so
+		// clone the utility VM from the parent layer into this layer. Use hard
+		// links to avoid unnecessary copying, since most of the files are
+		// immutable.
+		err = cloneTree(w.parentRoots[0], w.destRoot, utilityVMFilesPath, mutatedUtilityVMFiles)
+		if err != nil {
+			return fmt.Errorf("cloning the parent utility VM image failed: %s", err)
+		}
+		w.HasUtilityVM = true
+	}
+	return nil
+}
+
+func (w *legacyLayerWriter) reset() error {
+	err := w.bufWriter.Flush()
+	if err != nil {
+		return err
+	}
+	w.bufWriter.Reset(ioutil.Discard)
+	if w.currentIsDir {
+		r := w.currentFile
+		br := winio.NewBackupStreamReader(r)
+		// Seek to the beginning of the backup stream, skipping the fileattrs
+		if _, err := r.Seek(4, io.SeekStart); err != nil {
+			return err
+		}
+
+		for {
+			bhdr, err := br.Next()
+			if err == io.EOF {
+				// end of backupstream data
+				break
+			}
+			if err != nil {
+				return err
+			}
+			switch bhdr.Id {
+			case winio.BackupReparseData:
+				// The current file is a `.$wcidirs$` metadata file that
+				// describes a directory reparse point. Delete the placeholder
+				// directory to prevent future files being added into the
+				// destination of the reparse point during the ImportLayer call
+				if err := safefile.RemoveRelative(w.currentFileName, w.currentFileRoot); err != nil {
+					return err
+				}
+				w.pendingDirs = append(w.pendingDirs, pendingDir{Path: w.currentFileName, Root: w.currentFileRoot})
+			default:
+				// ignore all other stream types, as we only care about directory reparse points
+			}
+		}
+		w.currentIsDir = false
+	}
+	if w.backupWriter != nil {
+		w.backupWriter.Close()
+		w.backupWriter = nil
+	}
+	if w.currentFile != nil {
+		w.currentFile.Close()
+		w.currentFile = nil
+		w.currentFileName = ""
+		w.currentFileRoot = nil
+	}
+	return nil
+}
+
+// copyFileWithMetadata copies a file using the backup/restore APIs in order to preserve metadata
+func copyFileWithMetadata(srcRoot, destRoot *os.File, subPath string, isDir bool) (fileInfo *winio.FileBasicInfo, err error) {
+	src, err := safefile.OpenRelative(
+		subPath,
+		srcRoot,
+		syscall.GENERIC_READ|winio.ACCESS_SYSTEM_SECURITY,
+		syscall.FILE_SHARE_READ,
+		safefile.FILE_OPEN,
+		safefile.FILE_OPEN_REPARSE_POINT)
+	if err != nil {
+		return nil, err
+	}
+	defer src.Close()
+	srcr := winio.NewBackupFileReader(src, true)
+	defer srcr.Close()
+
+	fileInfo, err = winio.GetFileBasicInfo(src)
+	if err != nil {
+		return nil, err
+	}
+
+	extraFlags := uint32(0)
+	if isDir {
+		extraFlags |= safefile.FILE_DIRECTORY_FILE
+	}
+	dest, err := safefile.OpenRelative(
+		subPath,
+		destRoot,
+		syscall.GENERIC_READ|syscall.GENERIC_WRITE|winio.WRITE_DAC|winio.WRITE_OWNER|winio.ACCESS_SYSTEM_SECURITY,
+		syscall.FILE_SHARE_READ,
+		safefile.FILE_CREATE,
+		extraFlags)
+	if err != nil {
+		return nil, err
+	}
+	defer dest.Close()
+
+	err = winio.SetFileBasicInfo(dest, fileInfo)
+	if err != nil {
+		return nil, err
+	}
+
+	destw := winio.NewBackupFileWriter(dest, true)
+	defer func() {
+		cerr := destw.Close()
+		if err == nil {
+			err = cerr
+		}
+	}()
+
+	_, err = io.Copy(destw, srcr)
+	if err != nil {
+		return nil, err
+	}
+
+	return fileInfo, nil
+}
+
+// cloneTree clones a directory tree using hard links. It skips hard links for
+// the file names in the provided map and just copies those files.
+func cloneTree(srcRoot *os.File, destRoot *os.File, subPath string, mutatedFiles map[string]bool) error {
+	var di []dirInfo
+	err := safefile.EnsureNotReparsePointRelative(subPath, srcRoot)
+	if err != nil {
+		return err
+	}
+	err = filepath.Walk(filepath.Join(srcRoot.Name(), subPath), func(srcFilePath string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		relPath, err := filepath.Rel(srcRoot.Name(), srcFilePath)
+		if err != nil {
+			return err
+		}
+
+		fileAttributes := info.Sys().(*syscall.Win32FileAttributeData).FileAttributes
+		// Directories, reparse points, and files that will be mutated during
+		// utility VM import must be copied. All other files can be hard linked.
+		isReparsePoint := fileAttributes&syscall.FILE_ATTRIBUTE_REPARSE_POINT != 0
+		// In go1.9, FileInfo.IsDir() returns false if the directory is also a symlink.
+		// See: https://github.com/golang/go/commit/1989921aef60c83e6f9127a8448fb5ede10e9acc
+		// Fixes the problem by checking syscall.FILE_ATTRIBUTE_DIRECTORY directly
+		isDir := fileAttributes&syscall.FILE_ATTRIBUTE_DIRECTORY != 0
+
+		if isDir || isReparsePoint || mutatedFiles[relPath] {
+			fi, err := copyFileWithMetadata(srcRoot, destRoot, relPath, isDir)
+			if err != nil {
+				return err
+			}
+			if isDir && !isReparsePoint {
+				di = append(di, dirInfo{path: relPath, fileInfo: *fi})
+			}
+		} else {
+			err = safefile.LinkRelative(relPath, srcRoot, relPath, destRoot)
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	return reapplyDirectoryTimes(destRoot, di)
+}
+
+func (w *legacyLayerWriter) Add(name string, fileInfo *winio.FileBasicInfo) error {
+	if err := w.reset(); err != nil {
+		return err
+	}
+
+	if name == utilityVMPath {
+		return w.initUtilityVM()
+	}
+
+	name = filepath.Clean(name)
+	if hasPathPrefix(name, utilityVMPath) {
+		if !w.HasUtilityVM {
+			return errors.New("missing UtilityVM directory")
+		}
+		if !hasPathPrefix(name, utilityVMFilesPath) && name != utilityVMFilesPath {
+			return errors.New("invalid UtilityVM layer")
+		}
+		createDisposition := uint32(safefile.FILE_OPEN)
+		if (fileInfo.FileAttributes & syscall.FILE_ATTRIBUTE_DIRECTORY) != 0 {
+			st, err := safefile.LstatRelative(name, w.destRoot)
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+			if st != nil {
+				// Delete the existing file/directory if it is not the same type as this directory.
+				existingAttr := st.Sys().(*syscall.Win32FileAttributeData).FileAttributes
+				if (uint32(fileInfo.FileAttributes)^existingAttr)&(syscall.FILE_ATTRIBUTE_DIRECTORY|syscall.FILE_ATTRIBUTE_REPARSE_POINT) != 0 {
+					if err = safefile.RemoveAllRelative(name, w.destRoot); err != nil {
+						return err
+					}
+					st = nil
+				}
+			}
+			if st == nil {
+				if err = safefile.MkdirRelative(name, w.destRoot); err != nil {
+					return err
+				}
+			}
+			if fileInfo.FileAttributes&syscall.FILE_ATTRIBUTE_REPARSE_POINT == 0 {
+				w.uvmDi = append(w.uvmDi, dirInfo{path: name, fileInfo: *fileInfo})
+			}
+		} else {
+			// Overwrite any existing hard link.
+			err := safefile.RemoveRelative(name, w.destRoot)
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+			createDisposition = safefile.FILE_CREATE
+		}
+
+		f, err := safefile.OpenRelative(
+			name,
+			w.destRoot,
+			syscall.GENERIC_READ|syscall.GENERIC_WRITE|winio.WRITE_DAC|winio.WRITE_OWNER|winio.ACCESS_SYSTEM_SECURITY,
+			syscall.FILE_SHARE_READ,
+			createDisposition,
+			safefile.FILE_OPEN_REPARSE_POINT,
+		)
+		if err != nil {
+			return err
+		}
+		defer func() {
+			if f != nil {
+				f.Close()
+				safefile.RemoveRelative(name, w.destRoot)
+			}
+		}()
+
+		err = winio.SetFileBasicInfo(f, fileInfo)
+		if err != nil {
+			return err
+		}
+
+		w.backupWriter = winio.NewBackupFileWriter(f, true)
+		w.bufWriter.Reset(w.backupWriter)
+		w.currentFile = f
+		w.currentFileName = name
+		w.currentFileRoot = w.destRoot
+		w.addedFiles[name] = true
+		f = nil
+		return nil
+	}
+
+	fname := name
+	if (fileInfo.FileAttributes & syscall.FILE_ATTRIBUTE_DIRECTORY) != 0 {
+		err := safefile.MkdirRelative(name, w.root)
+		if err != nil {
+			return err
+		}
+		fname += ".$wcidirs$"
+		w.currentIsDir = true
+	}
+
+	f, err := safefile.OpenRelative(fname, w.root, syscall.GENERIC_READ|syscall.GENERIC_WRITE, syscall.FILE_SHARE_READ, safefile.FILE_CREATE, 0)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if f != nil {
+			f.Close()
+			safefile.RemoveRelative(fname, w.root)
+		}
+	}()
+
+	strippedFi := *fileInfo
+	strippedFi.FileAttributes = 0
+	err = winio.SetFileBasicInfo(f, &strippedFi)
+	if err != nil {
+		return err
+	}
+
+	if hasPathPrefix(name, hivesPath) {
+		w.backupWriter = winio.NewBackupFileWriter(f, false)
+		w.bufWriter.Reset(w.backupWriter)
+	} else {
+		w.bufWriter.Reset(f)
+		// The file attributes are written before the stream.
+		err = binary.Write(w.bufWriter, binary.LittleEndian, uint32(fileInfo.FileAttributes))
+		if err != nil {
+			w.bufWriter.Reset(ioutil.Discard)
+			return err
+		}
+	}
+
+	w.currentFile = f
+	w.currentFileName = name
+	w.currentFileRoot = w.root
+	w.addedFiles[name] = true
+	f = nil
+	return nil
+}
+
+func (w *legacyLayerWriter) AddLink(name string, target string) error {
+	if err := w.reset(); err != nil {
+		return err
+	}
+
+	target = filepath.Clean(target)
+	var roots []*os.File
+	if hasPathPrefix(target, filesPath) {
+		// Look for cross-layer hard link targets in the parent layers, since
+		// nothing is in the destination path yet.
+		roots = w.parentRoots
+	} else if hasPathPrefix(target, utilityVMFilesPath) {
+		// Since the utility VM is fully cloned into the destination path
+		// already, look for cross-layer hard link targets directly in the
+		// destination path.
+		roots = []*os.File{w.destRoot}
+	}
+
+	if roots == nil || (!hasPathPrefix(name, filesPath) && !hasPathPrefix(name, utilityVMFilesPath)) {
+		return errors.New("invalid hard link in layer")
+	}
+
+	// Find to try the target of the link in a previously added file. If that
+	// fails, search in parent layers.
+	var selectedRoot *os.File
+	if _, ok := w.addedFiles[target]; ok {
+		selectedRoot = w.destRoot
+	} else {
+		for _, r := range roots {
+			if _, err := safefile.LstatRelative(target, r); err != nil {
+				if !os.IsNotExist(err) {
+					return err
+				}
+			} else {
+				selectedRoot = r
+				break
+			}
+		}
+		if selectedRoot == nil {
+			return fmt.Errorf("failed to find link target for '%s' -> '%s'", name, target)
+		}
+	}
+
+	// The link can't be written until after the ImportLayer call.
+	w.PendingLinks = append(w.PendingLinks, pendingLink{
+		Path:       name,
+		Target:     target,
+		TargetRoot: selectedRoot,
+	})
+	w.addedFiles[name] = true
+	return nil
+}
+
+func (w *legacyLayerWriter) Remove(name string) error {
+	name = filepath.Clean(name)
+	if hasPathPrefix(name, filesPath) {
+		w.Tombstones = append(w.Tombstones, name)
+	} else if hasPathPrefix(name, utilityVMFilesPath) {
+		err := w.initUtilityVM()
+		if err != nil {
+			return err
+		}
+		// Make sure the path exists; os.RemoveAll will not fail if the file is
+		// already gone, and this needs to be a fatal error for diagnostics
+		// purposes.
+		if _, err := safefile.LstatRelative(name, w.destRoot); err != nil {
+			return err
+		}
+		err = safefile.RemoveAllRelative(name, w.destRoot)
+		if err != nil {
+			return err
+		}
+	} else {
+		return fmt.Errorf("invalid tombstone %s", name)
+	}
+
+	return nil
+}
+
+func (w *legacyLayerWriter) Write(b []byte) (int, error) {
+	if w.backupWriter == nil && w.currentFile == nil {
+		return 0, errors.New("closed")
+	}
+	return w.bufWriter.Write(b)
+}
+
+func (w *legacyLayerWriter) Close() error {
+	if err := w.reset(); err != nil {
+		return err
+	}
+	if err := safefile.RemoveRelative("tombstones.txt", w.root); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	for _, pd := range w.pendingDirs {
+		err := safefile.MkdirRelative(pd.Path, pd.Root)
+		if err != nil {
+			return err
+		}
+	}
+	if w.HasUtilityVM {
+		err := reapplyDirectoryTimes(w.destRoot, w.uvmDi)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}