go.mod: github.com/Microsoft/hcsshim v0.10.0-rc.7

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/AdaLogics/go-fuzz-headers v0.0.0-20230106234847-43070de90fa1
 	github.com/AdamKorcz/go-118-fuzz-build v0.0.0-20221215162035-5330a85ea652
 	github.com/Microsoft/go-winio v0.6.0
-	github.com/Microsoft/hcsshim v0.10.0-rc.5
+	github.com/Microsoft/hcsshim v0.10.0-rc.7
 	github.com/container-orchestrated-devices/container-device-interface v0.5.4
 	github.com/containerd/aufs v1.0.0
 	github.com/containerd/btrfs/v2 v2.0.0

go.sum

@@ -89,8 +89,8 @@ github.com/Microsoft/hcsshim v0.8.21/go.mod h1:+w2gRZ5ReXQhFOrvSQeNfhrYB/dg3oDwT
 github.com/Microsoft/hcsshim v0.8.23/go.mod h1:4zegtUJth7lAvFyc6cH2gGQ5B3OFQim01nnU2M8jKDg=
 github.com/Microsoft/hcsshim v0.9.2/go.mod h1:7pLA8lDk46WKDWlVsENo92gC0XFa8rbKfyFRBqxEbCc=
 github.com/Microsoft/hcsshim v0.9.4/go.mod h1:7pLA8lDk46WKDWlVsENo92gC0XFa8rbKfyFRBqxEbCc=
-github.com/Microsoft/hcsshim v0.10.0-rc.5 h1:JfkknPHBtfdC2Ezd+jpl8Kicw7UyhvUSzoy6xsqirwY=
-github.com/Microsoft/hcsshim v0.10.0-rc.5/go.mod h1:NNb9uh/cgA52AVhc9+Y7U+YyHQS9nHHA4STcAjdg2xk=
+github.com/Microsoft/hcsshim v0.10.0-rc.7 h1:HBytQPxcv8Oy4244zbQbe6hnOnx544eL5QPUqhJldz8=
+github.com/Microsoft/hcsshim v0.10.0-rc.7/go.mod h1:ILuwjA+kNW+MrN/w5un7n3mTqkwsFu4Bp05/okFUZlE=
 github.com/Microsoft/hcsshim/test v0.0.0-20201218223536-d3e5debf77da/go.mod h1:5hlzMzRKMLyo42nCZ9oml8AdTlq/0cvIaBv6tK1RehU=
 github.com/Microsoft/hcsshim/test v0.0.0-20210227013316-43a75bb4edd3/go.mod h1:mw7qgWloBUl75W/gVH3cQszUg1+gUITj7D6NY7ywVnY=
 github.com/NYTimes/gziphandler v0.0.0-20170623195520-56545f4a5d46/go.mod h1:3wb06e3pkSAbeQ52E9H9iFoQsEEwGN64994WTCIhntQ=

integration/client/go.mod

@@ -4,7 +4,7 @@ go 1.19
 
 require (
 	github.com/AdaLogics/go-fuzz-headers v0.0.0-20230106234847-43070de90fa1
-	github.com/Microsoft/hcsshim v0.10.0-rc.5
+	github.com/Microsoft/hcsshim v0.10.0-rc.7
 	github.com/Microsoft/hcsshim/test v0.0.0-20210408205431-da33ecd607e1
 	github.com/containerd/cgroups/v3 v3.0.0
 	github.com/containerd/containerd v1.7.0-beta.0 // see replace; the actual version of containerd is replaced with the code at the root of this repository

integration/client/go.sum

@@ -408,8 +408,8 @@ github.com/Microsoft/go-winio v0.6.0/go.mod h1:cTAf44im0RAYeL23bpB+fzCyDH2MJiz2B
 github.com/Microsoft/hcsshim v0.8.15/go.mod h1:x38A4YbHbdxJtc0sF6oIz+RG0npwSCAvn69iY6URG00=
 github.com/Microsoft/hcsshim v0.9.4/go.mod h1:7pLA8lDk46WKDWlVsENo92gC0XFa8rbKfyFRBqxEbCc=
 github.com/Microsoft/hcsshim v0.9.6/go.mod h1:7pLA8lDk46WKDWlVsENo92gC0XFa8rbKfyFRBqxEbCc=
-github.com/Microsoft/hcsshim v0.10.0-rc.5 h1:JfkknPHBtfdC2Ezd+jpl8Kicw7UyhvUSzoy6xsqirwY=
-github.com/Microsoft/hcsshim v0.10.0-rc.5/go.mod h1:NNb9uh/cgA52AVhc9+Y7U+YyHQS9nHHA4STcAjdg2xk=
+github.com/Microsoft/hcsshim v0.10.0-rc.7 h1:HBytQPxcv8Oy4244zbQbe6hnOnx544eL5QPUqhJldz8=
+github.com/Microsoft/hcsshim v0.10.0-rc.7/go.mod h1:ILuwjA+kNW+MrN/w5un7n3mTqkwsFu4Bp05/okFUZlE=
 github.com/Microsoft/hcsshim/test v0.0.0-20210408205431-da33ecd607e1 h1:pVKfKyPkXna29XlGjxSr9J0A7vNucOUHZ/2ClcTWalw=
 github.com/Microsoft/hcsshim/test v0.0.0-20210408205431-da33ecd607e1/go.mod h1:Cmvnhlie15Ha2UYrJs9EhgSx76Bq9RV2FgfEiT78GhI=
 github.com/NYTimes/gziphandler v0.0.0-20170623195520-56545f4a5d46/go.mod h1:3wb06e3pkSAbeQ52E9H9iFoQsEEwGN64994WTCIhntQ=

vendor/github.com/Microsoft/hcsshim/ext4/dmverity/dmverity.go

@@ -99,8 +99,10 @@ func MerkleTree(r io.Reader) ([]byte, error) {
 			nextLevel.Write(h)
 		}
 
-		padding := bytes.Repeat([]byte{0}, blockSize-(nextLevel.Len()%blockSize))
-		nextLevel.Write(padding)
+		if nextLevel.Len()%blockSize != 0 {
+			padding := bytes.Repeat([]byte{0}, blockSize-(nextLevel.Len()%blockSize))
+			nextLevel.Write(padding)
+		}
 
 		layers = append(layers, nextLevel.Bytes())
 		currentLevel = bufio.NewReaderSize(nextLevel, MerkleTreeBufioSize)

vendor/github.com/Microsoft/hcsshim/ext4/tar2ext4/tar2ext4.go

@@ -249,6 +249,7 @@ func ConvertAndComputeRootDigest(r io.Reader) (string, error) {
 	defer func() {
 		_ = os.Remove(out.Name())
 	}()
+	defer out.Close()
 
 	options := []Option{
 		ConvertWhiteout,

vendor/github.com/Microsoft/hcsshim/internal/wclayer/baselayerreader.go

@@ -0,0 +1,216 @@
+package wclayer
+
+import (
+	"errors"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/hcsshim/internal/longpath"
+	"github.com/Microsoft/hcsshim/internal/oc"
+	"go.opencensus.io/trace"
+)
+
+type baseLayerReader struct {
+	s            *trace.Span
+	root         string
+	result       chan *fileEntry
+	proceed      chan bool
+	currentFile  *os.File
+	backupReader *winio.BackupFileReader
+}
+
+func newBaseLayerReader(root string, s *trace.Span) (r *baseLayerReader) {
+	r = &baseLayerReader{
+		s:       s,
+		root:    root,
+		result:  make(chan *fileEntry),
+		proceed: make(chan bool),
+	}
+	go r.walk()
+	return r
+}
+
+func (r *baseLayerReader) walkUntilCancelled() error {
+	root, err := longpath.LongAbs(r.root)
+	if err != nil {
+		return err
+	}
+
+	r.root = root
+
+	err = filepath.Walk(filepath.Join(r.root, filesPath), 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
+		}
+
+		r.result <- &fileEntry{path, info, nil}
+		if !<-r.proceed {
+			return errorIterationCanceled
+		}
+
+		return nil
+	})
+
+	if err == errorIterationCanceled {
+		return nil
+	}
+
+	if err != nil {
+		return err
+	}
+
+	utilityVMAbsPath := filepath.Join(r.root, utilityVMPath)
+	utilityVMFilesAbsPath := filepath.Join(r.root, utilityVMFilesPath)
+
+	// Ignore a UtilityVM without Files, that's not _really_ a UtiltyVM
+	if _, err = os.Lstat(utilityVMFilesAbsPath); err != nil {
+		if os.IsNotExist(err) {
+			return io.EOF
+		}
+		return err
+	}
+
+	err = filepath.Walk(utilityVMAbsPath, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if path != utilityVMAbsPath && path != utilityVMFilesAbsPath && !hasPathPrefix(path, utilityVMFilesAbsPath) {
+			if info.IsDir() {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+
+		r.result <- &fileEntry{path, info, nil}
+		if !<-r.proceed {
+			return errorIterationCanceled
+		}
+
+		return nil
+	})
+
+	if err == errorIterationCanceled {
+		return nil
+	}
+
+	if err != nil {
+		return err
+	}
+
+	return io.EOF
+}
+
+func (r *baseLayerReader) 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 *baseLayerReader) reset() {
+	if r.backupReader != nil {
+		r.backupReader.Close()
+		r.backupReader = nil
+	}
+	if r.currentFile != nil {
+		r.currentFile.Close()
+		r.currentFile = nil
+	}
+}
+
+func (r *baseLayerReader) Next() (path string, size int64, fileInfo *winio.FileBasicInfo, err error) {
+	r.reset()
+	r.proceed <- true
+	fe := <-r.result
+	if fe == nil {
+		err = errors.New("BaseLayerReader closed")
+		return
+	}
+	if fe.err != nil {
+		err = fe.err
+		return
+	}
+
+	path, err = filepath.Rel(r.root, fe.path)
+	if err != nil {
+		return
+	}
+
+	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
+	}
+
+	size = fe.fi.Size()
+	r.backupReader = winio.NewBackupFileReader(f, true)
+
+	r.currentFile = f
+	f = nil
+	return
+}
+
+func (r *baseLayerReader) LinkInfo() (uint32, *winio.FileIDInfo, error) {
+	fileStandardInfo, err := winio.GetFileStandardInfo(r.currentFile)
+	if err != nil {
+		return 0, nil, err
+	}
+	fileIDInfo, err := winio.GetFileID(r.currentFile)
+	if err != nil {
+		return 0, nil, err
+	}
+	return fileStandardInfo.NumberOfLinks, fileIDInfo, nil
+}
+
+func (r *baseLayerReader) Read(b []byte) (int, error) {
+	if r.backupReader == nil {
+		return 0, io.EOF
+	}
+	return r.backupReader.Read(b)
+}
+
+func (r *baseLayerReader) Close() (err error) {
+	defer r.s.End()
+	defer func() {
+		oc.SetSpanStatus(r.s, err)
+		close(r.proceed)
+	}()
+	r.proceed <- false
+	// The r.result channel will be closed once walk() returns
+	<-r.result
+	r.reset()
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/converttobaselayer.go

@@ -0,0 +1,158 @@
+package wclayer
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/Microsoft/hcsshim/internal/longpath"
+	"github.com/Microsoft/hcsshim/internal/oc"
+	"github.com/Microsoft/hcsshim/internal/safefile"
+	"github.com/Microsoft/hcsshim/internal/winapi"
+	"github.com/pkg/errors"
+	"go.opencensus.io/trace"
+	"golang.org/x/sys/windows"
+)
+
+var hiveNames = []string{"DEFAULT", "SAM", "SECURITY", "SOFTWARE", "SYSTEM"}
+
+// Ensure the given file exists as an ordinary file, and create a minimal hive file if not.
+func ensureHive(path string, root *os.File) (err error) {
+	_, err = safefile.LstatRelative(path, root)
+	if err != nil && !os.IsNotExist(err) {
+		return fmt.Errorf("accessing %s: %w", path, err)
+	}
+
+	version := windows.RtlGetVersion()
+	if version == nil {
+		return fmt.Errorf("failed to get OS version")
+	}
+
+	var fullPath string
+	fullPath, err = longpath.LongAbs(filepath.Join(root.Name(), path))
+	if err != nil {
+		return fmt.Errorf("getting path: %w", err)
+	}
+
+	var key syscall.Handle
+	err = winapi.ORCreateHive(&key)
+	if err != nil {
+		return fmt.Errorf("creating hive: %w", err)
+	}
+
+	defer func() {
+		closeErr := winapi.ORCloseHive(key)
+		if closeErr != nil && err == nil {
+			err = fmt.Errorf("closing hive key: %w", closeErr)
+		}
+	}()
+
+	err = winapi.ORSaveHive(key, fullPath, version.MajorVersion, version.MinorVersion)
+	if err != nil {
+		return fmt.Errorf("saving hive: %w", err)
+	}
+
+	return nil
+}
+
+func ensureBaseLayer(root *os.File) (hasUtilityVM bool, err error) {
+	// The base layer registry hives will be copied from here
+	const hiveSourcePath = "Files\\Windows\\System32\\config"
+	if err = safefile.MkdirAllRelative(hiveSourcePath, root); err != nil {
+		return
+	}
+
+	for _, hiveName := range hiveNames {
+		hivePath := filepath.Join(hiveSourcePath, hiveName)
+		if err = ensureHive(hivePath, root); err != nil {
+			return
+		}
+	}
+
+	stat, err := safefile.LstatRelative(utilityVMFilesPath, root)
+
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+
+	if err != nil {
+		return
+	}
+
+	if !stat.Mode().IsDir() {
+		fullPath := filepath.Join(root.Name(), utilityVMFilesPath)
+		return false, errors.Errorf("%s has unexpected file mode %s", fullPath, stat.Mode().String())
+	}
+
+	const bcdRelativePath = "EFI\\Microsoft\\Boot\\BCD"
+
+	// Just check that this exists as a regular file. If it exists but is not a valid registry hive,
+	// ProcessUtilityVMImage will complain:
+	// "The registry could not read in, or write out, or flush, one of the files that contain the system's image of the registry."
+	bcdPath := filepath.Join(utilityVMFilesPath, bcdRelativePath)
+
+	stat, err = safefile.LstatRelative(bcdPath, root)
+	if err != nil {
+		return false, errors.Wrapf(err, "UtilityVM must contain '%s'", bcdRelativePath)
+	}
+
+	if !stat.Mode().IsRegular() {
+		fullPath := filepath.Join(root.Name(), bcdPath)
+		return false, errors.Errorf("%s has unexpected file mode %s", fullPath, stat.Mode().String())
+	}
+
+	return true, nil
+}
+
+func convertToBaseLayer(ctx context.Context, root *os.File) error {
+	hasUtilityVM, err := ensureBaseLayer(root)
+
+	if err != nil {
+		return err
+	}
+
+	if err := ProcessBaseLayer(ctx, root.Name()); err != nil {
+		return err
+	}
+
+	if !hasUtilityVM {
+		return nil
+	}
+
+	err = safefile.EnsureNotReparsePointRelative(utilityVMPath, root)
+	if err != nil {
+		return err
+	}
+
+	utilityVMPath := filepath.Join(root.Name(), utilityVMPath)
+	return ProcessUtilityVMImage(ctx, utilityVMPath)
+}
+
+// ConvertToBaseLayer processes a candidate base layer, i.e. a directory
+// containing the desired file content under Files/, and optionally the
+// desired file content for a UtilityVM under UtilityVM/Files/
+func ConvertToBaseLayer(ctx context.Context, path string) (err error) {
+	title := "hcsshim::ConvertToBaseLayer"
+	ctx, span := trace.StartSpan(ctx, title)
+	defer span.End()
+	defer func() { oc.SetSpanStatus(span, err) }()
+	span.AddAttributes(trace.StringAttribute("path", path))
+
+	root, err := safefile.OpenRoot(path)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	defer func() {
+		if err2 := root.Close(); err == nil && err2 != nil {
+			err = hcserror.New(err2, title+" - failed", "")
+		}
+	}()
+
+	if err = convertToBaseLayer(ctx, root); err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/exportlayer.go

@@ -45,6 +45,8 @@ func ExportLayer(ctx context.Context, path string, exportFolderPath string, pare
 type LayerReader interface {
 	// Next advances to the next file and returns the name, size, and file info
 	Next() (string, int64, *winio.FileBasicInfo, error)
+	// LinkInfo returns the number of links and the file identifier for the current file.
+	LinkInfo() (uint32, *winio.FileIDInfo, error)
 	// Read reads data from the current file, in the format of a Win32 backup stream, and
 	// returns the number of bytes read.
 	Read(b []byte) (int, error)
@@ -67,6 +69,11 @@ func NewLayerReader(ctx context.Context, path string, parentLayerPaths []string)
 		trace.StringAttribute("path", path),
 		trace.StringAttribute("parentLayerPaths", strings.Join(parentLayerPaths, ", ")))
 
+	if len(parentLayerPaths) == 0 {
+		// This is a base layer. It gets exported differently.
+		return newBaseLayerReader(path, span), nil
+	}
+
 	exportPath, err := os.MkdirTemp("", "hcs")
 	if err != nil {
 		return nil, err

vendor/github.com/Microsoft/hcsshim/internal/wclayer/legacy.go

@@ -294,6 +294,18 @@ func (r *legacyLayerReader) Next() (path string, size int64, fileInfo *winio.Fil
 	return
 }
 
+func (r *legacyLayerReader) LinkInfo() (uint32, *winio.FileIDInfo, error) {
+	fileStandardInfo, err := winio.GetFileStandardInfo(r.currentFile)
+	if err != nil {
+		return 0, nil, err
+	}
+	fileIDInfo, err := winio.GetFileID(r.currentFile)
+	if err != nil {
+		return 0, nil, err
+	}
+	return fileStandardInfo.NumberOfLinks, fileIDInfo, nil
+}
+
 func (r *legacyLayerReader) Read(b []byte) (int, error) {
 	if r.backupReader == nil {
 		if r.currentFile == nil {

vendor/github.com/Microsoft/hcsshim/internal/winapi/ofreg.go

@@ -0,0 +1,5 @@
+package winapi
+
+//sys ORCreateHive(key *syscall.Handle) (regerrno error) = offreg.ORCreateHive
+//sys ORSaveHive(key syscall.Handle, file string, OsMajorVersion uint32, OsMinorVersion uint32) (regerrno error) = offreg.ORSaveHive
+//sys ORCloseHive(key syscall.Handle) (regerrno error) = offreg.ORCloseHive

vendor/github.com/Microsoft/hcsshim/internal/winapi/zsyscall_windows.go

@@ -47,6 +47,7 @@ var (
 	modkernel32   = windows.NewLazySystemDLL("kernel32.dll")
 	modnetapi32   = windows.NewLazySystemDLL("netapi32.dll")
 	modntdll      = windows.NewLazySystemDLL("ntdll.dll")
+	modoffreg     = windows.NewLazySystemDLL("offreg.dll")
 
 	procLogonUserW                             = modadvapi32.NewProc("LogonUserW")
 	procBfSetupFilter                          = modbindfltapi.NewProc("BfSetupFilter")
@@ -82,6 +83,9 @@ var (
 	procNtQuerySystemInformation               = modntdll.NewProc("NtQuerySystemInformation")
 	procNtSetInformationFile                   = modntdll.NewProc("NtSetInformationFile")
 	procRtlNtStatusToDosError                  = modntdll.NewProc("RtlNtStatusToDosError")
+	procORCloseHive                            = modoffreg.NewProc("ORCloseHive")
+	procORCreateHive                           = modoffreg.NewProc("ORCreateHive")
+	procORSaveHive                             = modoffreg.NewProc("ORSaveHive")
 )
 
 func LogonUser(username *uint16, domain *uint16, password *uint16, logonType uint32, logonProvider uint32, token *windows.Token) (err error) {
@@ -376,3 +380,36 @@ func RtlNtStatusToDosError(status uint32) (winerr error) {
 	}
 	return
 }
+
+func ORCloseHive(key syscall.Handle) (regerrno error) {
+	r0, _, _ := syscall.Syscall(procORCloseHive.Addr(), 1, uintptr(key), 0, 0)
+	if r0 != 0 {
+		regerrno = syscall.Errno(r0)
+	}
+	return
+}
+
+func ORCreateHive(key *syscall.Handle) (regerrno error) {
+	r0, _, _ := syscall.Syscall(procORCreateHive.Addr(), 1, uintptr(unsafe.Pointer(key)), 0, 0)
+	if r0 != 0 {
+		regerrno = syscall.Errno(r0)
+	}
+	return
+}
+
+func ORSaveHive(key syscall.Handle, file string, OsMajorVersion uint32, OsMinorVersion uint32) (regerrno error) {
+	var _p0 *uint16
+	_p0, regerrno = syscall.UTF16PtrFromString(file)
+	if regerrno != nil {
+		return
+	}
+	return _ORSaveHive(key, _p0, OsMajorVersion, OsMinorVersion)
+}
+
+func _ORSaveHive(key syscall.Handle, file *uint16, OsMajorVersion uint32, OsMinorVersion uint32) (regerrno error) {
+	r0, _, _ := syscall.Syscall6(procORSaveHive.Addr(), 4, uintptr(key), uintptr(unsafe.Pointer(file)), uintptr(OsMajorVersion), uintptr(OsMinorVersion), 0, 0)
+	if r0 != 0 {
+		regerrno = syscall.Errno(r0)
+	}
+	return
+}

vendor/github.com/Microsoft/hcsshim/layer.go

@@ -70,6 +70,9 @@ func ProcessUtilityVMImage(path string) error {
 func UnprepareLayer(info DriverInfo, layerId string) error {
 	return wclayer.UnprepareLayer(context.Background(), layerPath(&info, layerId))
 }
+func ConvertToBaseLayer(path string) error {
+	return wclayer.ConvertToBaseLayer(context.Background(), path)
+}
 
 type DriverInfo struct {
 	Flavour int

vendor/github.com/Microsoft/hcsshim/osversion/osversion_windows.go

@@ -1,5 +1,3 @@
-//go:build windows
-
 package osversion
 
 import (
@@ -47,6 +45,15 @@ func Build() uint16 {
 	return Get().Build
 }
 
-func (osv OSVersion) ToString() string {
+// String returns the OSVersion formatted as a string. It implements the
+// [fmt.Stringer] interface.
+func (osv OSVersion) String() string {
 	return fmt.Sprintf("%d.%d.%d", osv.MajorVersion, osv.MinorVersion, osv.Build)
 }
+
+// ToString returns the OSVersion formatted as a string.
+//
+// Deprecated: use [OSVersion.String].
+func (osv OSVersion) ToString() string {
+	return osv.String()
+}

vendor/github.com/Microsoft/hcsshim/pkg/ociwclayer/export.go

@@ -51,6 +51,8 @@ func ExportLayerToTar(ctx context.Context, w io.Writer, path string, parentLayer
 }
 
 func writeTarFromLayer(ctx context.Context, r wclayer.LayerReader, w io.Writer) error {
+	linkRecords := make(map[[16]byte]string)
+
 	t := tar.NewWriter(w)
 	for {
 		select {
@@ -76,6 +78,27 @@ func writeTarFromLayer(ctx context.Context, r wclayer.LayerReader, w io.Writer)
 				return err
 			}
 		} else {
+			numberOfLinks, fileIDInfo, err := r.LinkInfo()
+			if err != nil {
+				return err
+			}
+			if numberOfLinks > 1 {
+				if linkName, ok := linkRecords[fileIDInfo.FileID]; ok {
+					// We've seen this file before, by another name, so put a hardlink in the tar stream.
+					hdr := backuptar.BasicInfoHeader(name, 0, fileInfo)
+					hdr.Mode = 0644
+					hdr.Typeflag = tar.TypeLink
+					hdr.Linkname = linkName
+					if err := t.WriteHeader(hdr); err != nil {
+						return err
+					}
+					continue
+				}
+
+				// All subsequent names for this file will be hard-linked to this name
+				linkRecords[fileIDInfo.FileID] = filepath.ToSlash(name)
+			}
+
 			err = backuptar.WriteTarFileFromBackupStream(t, r, name, size, fileInfo)
 			if err != nil {
 				return err

vendor/modules.txt

@@ -16,7 +16,7 @@ github.com/Microsoft/go-winio/pkg/guid
 github.com/Microsoft/go-winio/pkg/security
 github.com/Microsoft/go-winio/tools/mkwinsyscall
 github.com/Microsoft/go-winio/vhd
-# github.com/Microsoft/hcsshim v0.10.0-rc.5
+# github.com/Microsoft/hcsshim v0.10.0-rc.7
 ## explicit; go 1.18
 github.com/Microsoft/hcsshim
 github.com/Microsoft/hcsshim/cmd/containerd-shim-runhcs-v1/options