vendor: add missing deps and remove go get in .travis.yml

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

vendor/github.com/docker/docker/pkg/archive/archive_linux.go

@@ -0,0 +1,95 @@
+package archive
+
+import (
+	"archive/tar"
+	"os"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+func getWhiteoutConverter(format WhiteoutFormat) tarWhiteoutConverter {
+	if format == OverlayWhiteoutFormat {
+		return overlayWhiteoutConverter{}
+	}
+	return nil
+}
+
+type overlayWhiteoutConverter struct{}
+
+func (overlayWhiteoutConverter) ConvertWrite(hdr *tar.Header, path string, fi os.FileInfo) (wo *tar.Header, err error) {
+	// convert whiteouts to AUFS format
+	if fi.Mode()&os.ModeCharDevice != 0 && hdr.Devmajor == 0 && hdr.Devminor == 0 {
+		// we just rename the file and make it normal
+		dir, filename := filepath.Split(hdr.Name)
+		hdr.Name = filepath.Join(dir, WhiteoutPrefix+filename)
+		hdr.Mode = 0600
+		hdr.Typeflag = tar.TypeReg
+		hdr.Size = 0
+	}
+
+	if fi.Mode()&os.ModeDir != 0 {
+		// convert opaque dirs to AUFS format by writing an empty file with the prefix
+		opaque, err := system.Lgetxattr(path, "trusted.overlay.opaque")
+		if err != nil {
+			return nil, err
+		}
+		if len(opaque) == 1 && opaque[0] == 'y' {
+			if hdr.Xattrs != nil {
+				delete(hdr.Xattrs, "trusted.overlay.opaque")
+			}
+
+			// create a header for the whiteout file
+			// it should inherit some properties from the parent, but be a regular file
+			wo = &tar.Header{
+				Typeflag:   tar.TypeReg,
+				Mode:       hdr.Mode & int64(os.ModePerm),
+				Name:       filepath.Join(hdr.Name, WhiteoutOpaqueDir),
+				Size:       0,
+				Uid:        hdr.Uid,
+				Uname:      hdr.Uname,
+				Gid:        hdr.Gid,
+				Gname:      hdr.Gname,
+				AccessTime: hdr.AccessTime,
+				ChangeTime: hdr.ChangeTime,
+			}
+		}
+	}
+
+	return
+}
+
+func (overlayWhiteoutConverter) ConvertRead(hdr *tar.Header, path string) (bool, error) {
+	base := filepath.Base(path)
+	dir := filepath.Dir(path)
+
+	// if a directory is marked as opaque by the AUFS special file, we need to translate that to overlay
+	if base == WhiteoutOpaqueDir {
+		if err := syscall.Setxattr(dir, "trusted.overlay.opaque", []byte{'y'}, 0); err != nil {
+			return false, err
+		}
+
+		// don't write the file itself
+		return false, nil
+	}
+
+	// if a file was deleted and we are using overlay, we need to create a character device
+	if strings.HasPrefix(base, WhiteoutPrefix) {
+		originalBase := base[len(WhiteoutPrefix):]
+		originalPath := filepath.Join(dir, originalBase)
+
+		if err := syscall.Mknod(originalPath, syscall.S_IFCHR, 0); err != nil {
+			return false, err
+		}
+		if err := os.Chown(originalPath, hdr.Uid, hdr.Gid); err != nil {
+			return false, err
+		}
+
+		// don't write the file itself
+		return false, nil
+	}
+
+	return true, nil
+}

vendor/github.com/docker/docker/pkg/archive/archive_other.go

@@ -0,0 +1,7 @@
+// +build !linux
+
+package archive
+
+func getWhiteoutConverter(format WhiteoutFormat) tarWhiteoutConverter {
+	return nil
+}

vendor/github.com/docker/docker/pkg/archive/archive_unix.go

@@ -0,0 +1,118 @@
+// +build !windows
+
+package archive
+
+import (
+	"archive/tar"
+	"errors"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/docker/docker/pkg/system"
+	rsystem "github.com/opencontainers/runc/libcontainer/system"
+)
+
+// fixVolumePathPrefix does platform specific processing to ensure that if
+// the path being passed in is not in a volume path format, convert it to one.
+func fixVolumePathPrefix(srcPath string) string {
+	return srcPath
+}
+
+// getWalkRoot calculates the root path when performing a TarWithOptions.
+// We use a separate function as this is platform specific. On Linux, we
+// can't use filepath.Join(srcPath,include) because this will clean away
+// a trailing "." or "/" which may be important.
+func getWalkRoot(srcPath string, include string) string {
+	return srcPath + string(filepath.Separator) + include
+}
+
+// CanonicalTarNameForPath returns platform-specific filepath
+// to canonical posix-style path for tar archival. p is relative
+// path.
+func CanonicalTarNameForPath(p string) (string, error) {
+	return p, nil // already unix-style
+}
+
+// chmodTarEntry is used to adjust the file permissions used in tar header based
+// on the platform the archival is done.
+
+func chmodTarEntry(perm os.FileMode) os.FileMode {
+	return perm // noop for unix as golang APIs provide perm bits correctly
+}
+
+func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, stat interface{}) (inode uint64, err error) {
+	s, ok := stat.(*syscall.Stat_t)
+
+	if !ok {
+		err = errors.New("cannot convert stat value to syscall.Stat_t")
+		return
+	}
+
+	inode = uint64(s.Ino)
+
+	// Currently go does not fill in the major/minors
+	if s.Mode&syscall.S_IFBLK != 0 ||
+		s.Mode&syscall.S_IFCHR != 0 {
+		hdr.Devmajor = int64(major(uint64(s.Rdev)))
+		hdr.Devminor = int64(minor(uint64(s.Rdev)))
+	}
+
+	return
+}
+
+func getFileUIDGID(stat interface{}) (int, int, error) {
+	s, ok := stat.(*syscall.Stat_t)
+
+	if !ok {
+		return -1, -1, errors.New("cannot convert stat value to syscall.Stat_t")
+	}
+	return int(s.Uid), int(s.Gid), nil
+}
+
+func major(device uint64) uint64 {
+	return (device >> 8) & 0xfff
+}
+
+func minor(device uint64) uint64 {
+	return (device & 0xff) | ((device >> 12) & 0xfff00)
+}
+
+// handleTarTypeBlockCharFifo is an OS-specific helper function used by
+// createTarFile to handle the following types of header: Block; Char; Fifo
+func handleTarTypeBlockCharFifo(hdr *tar.Header, path string) error {
+	if rsystem.RunningInUserNS() {
+		// cannot create a device if running in user namespace
+		return nil
+	}
+
+	mode := uint32(hdr.Mode & 07777)
+	switch hdr.Typeflag {
+	case tar.TypeBlock:
+		mode |= syscall.S_IFBLK
+	case tar.TypeChar:
+		mode |= syscall.S_IFCHR
+	case tar.TypeFifo:
+		mode |= syscall.S_IFIFO
+	}
+
+	if err := system.Mknod(path, mode, int(system.Mkdev(hdr.Devmajor, hdr.Devminor))); err != nil {
+		return err
+	}
+	return nil
+}
+
+func handleLChmod(hdr *tar.Header, path string, hdrInfo os.FileInfo) error {
+	if hdr.Typeflag == tar.TypeLink {
+		if fi, err := os.Lstat(hdr.Linkname); err == nil && (fi.Mode()&os.ModeSymlink == 0) {
+			if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
+				return err
+			}
+		}
+	} else if hdr.Typeflag != tar.TypeSymlink {
+		if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
+			return err
+		}
+	}
+	return nil
+}

vendor/github.com/docker/docker/pkg/archive/archive_windows.go

@@ -0,0 +1,70 @@
+// +build windows
+
+package archive
+
+import (
+	"archive/tar"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/docker/docker/pkg/longpath"
+)
+
+// fixVolumePathPrefix does platform specific processing to ensure that if
+// the path being passed in is not in a volume path format, convert it to one.
+func fixVolumePathPrefix(srcPath string) string {
+	return longpath.AddPrefix(srcPath)
+}
+
+// getWalkRoot calculates the root path when performing a TarWithOptions.
+// We use a separate function as this is platform specific.
+func getWalkRoot(srcPath string, include string) string {
+	return filepath.Join(srcPath, include)
+}
+
+// CanonicalTarNameForPath returns platform-specific filepath
+// to canonical posix-style path for tar archival. p is relative
+// path.
+func CanonicalTarNameForPath(p string) (string, error) {
+	// windows: convert windows style relative path with backslashes
+	// into forward slashes. Since windows does not allow '/' or '\'
+	// in file names, it is mostly safe to replace however we must
+	// check just in case
+	if strings.Contains(p, "/") {
+		return "", fmt.Errorf("Windows path contains forward slash: %s", p)
+	}
+	return strings.Replace(p, string(os.PathSeparator), "/", -1), nil
+
+}
+
+// chmodTarEntry is used to adjust the file permissions used in tar header based
+// on the platform the archival is done.
+func chmodTarEntry(perm os.FileMode) os.FileMode {
+	perm &= 0755
+	// Add the x bit: make everything +x from windows
+	perm |= 0111
+
+	return perm
+}
+
+func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, stat interface{}) (inode uint64, err error) {
+	// do nothing. no notion of Rdev, Inode, Nlink in stat on Windows
+	return
+}
+
+// handleTarTypeBlockCharFifo is an OS-specific helper function used by
+// createTarFile to handle the following types of header: Block; Char; Fifo
+func handleTarTypeBlockCharFifo(hdr *tar.Header, path string) error {
+	return nil
+}
+
+func handleLChmod(hdr *tar.Header, path string, hdrInfo os.FileInfo) error {
+	return nil
+}
+
+func getFileUIDGID(stat interface{}) (int, int, error) {
+	// no notion of file ownership mapping yet on Windows
+	return 0, 0, nil
+}

vendor/github.com/docker/docker/pkg/archive/changes.go

@@ -0,0 +1,446 @@
+package archive
+
+import (
+	"archive/tar"
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/pkg/idtools"
+	"github.com/docker/docker/pkg/pools"
+	"github.com/docker/docker/pkg/system"
+)
+
+// ChangeType represents the change type.
+type ChangeType int
+
+const (
+	// ChangeModify represents the modify operation.
+	ChangeModify = iota
+	// ChangeAdd represents the add operation.
+	ChangeAdd
+	// ChangeDelete represents the delete operation.
+	ChangeDelete
+)
+
+func (c ChangeType) String() string {
+	switch c {
+	case ChangeModify:
+		return "C"
+	case ChangeAdd:
+		return "A"
+	case ChangeDelete:
+		return "D"
+	}
+	return ""
+}
+
+// Change represents a change, it wraps the change type and path.
+// It describes changes of the files in the path respect to the
+// parent layers. The change could be modify, add, delete.
+// This is used for layer diff.
+type Change struct {
+	Path string
+	Kind ChangeType
+}
+
+func (change *Change) String() string {
+	return fmt.Sprintf("%s %s", change.Kind, change.Path)
+}
+
+// for sort.Sort
+type changesByPath []Change
+
+func (c changesByPath) Less(i, j int) bool { return c[i].Path < c[j].Path }
+func (c changesByPath) Len() int           { return len(c) }
+func (c changesByPath) Swap(i, j int)      { c[j], c[i] = c[i], c[j] }
+
+// Gnu tar and the go tar writer don't have sub-second mtime
+// precision, which is problematic when we apply changes via tar
+// files, we handle this by comparing for exact times, *or* same
+// second count and either a or b having exactly 0 nanoseconds
+func sameFsTime(a, b time.Time) bool {
+	return a == b ||
+		(a.Unix() == b.Unix() &&
+			(a.Nanosecond() == 0 || b.Nanosecond() == 0))
+}
+
+func sameFsTimeSpec(a, b syscall.Timespec) bool {
+	return a.Sec == b.Sec &&
+		(a.Nsec == b.Nsec || a.Nsec == 0 || b.Nsec == 0)
+}
+
+// Changes walks the path rw and determines changes for the files in the path,
+// with respect to the parent layers
+func Changes(layers []string, rw string) ([]Change, error) {
+	return changes(layers, rw, aufsDeletedFile, aufsMetadataSkip)
+}
+
+func aufsMetadataSkip(path string) (skip bool, err error) {
+	skip, err = filepath.Match(string(os.PathSeparator)+WhiteoutMetaPrefix+"*", path)
+	if err != nil {
+		skip = true
+	}
+	return
+}
+
+func aufsDeletedFile(root, path string, fi os.FileInfo) (string, error) {
+	f := filepath.Base(path)
+
+	// If there is a whiteout, then the file was removed
+	if strings.HasPrefix(f, WhiteoutPrefix) {
+		originalFile := f[len(WhiteoutPrefix):]
+		return filepath.Join(filepath.Dir(path), originalFile), nil
+	}
+
+	return "", nil
+}
+
+type skipChange func(string) (bool, error)
+type deleteChange func(string, string, os.FileInfo) (string, error)
+
+func changes(layers []string, rw string, dc deleteChange, sc skipChange) ([]Change, error) {
+	var (
+		changes     []Change
+		changedDirs = make(map[string]struct{})
+	)
+
+	err := filepath.Walk(rw, func(path string, f os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Rebase path
+		path, err = filepath.Rel(rw, path)
+		if err != nil {
+			return err
+		}
+
+		// As this runs on the daemon side, file paths are OS specific.
+		path = filepath.Join(string(os.PathSeparator), path)
+
+		// Skip root
+		if path == string(os.PathSeparator) {
+			return nil
+		}
+
+		if sc != nil {
+			if skip, err := sc(path); skip {
+				return err
+			}
+		}
+
+		change := Change{
+			Path: path,
+		}
+
+		deletedFile, err := dc(rw, path, f)
+		if err != nil {
+			return err
+		}
+
+		// Find out what kind of modification happened
+		if deletedFile != "" {
+			change.Path = deletedFile
+			change.Kind = ChangeDelete
+		} else {
+			// Otherwise, the file was added
+			change.Kind = ChangeAdd
+
+			// ...Unless it already existed in a top layer, in which case, it's a modification
+			for _, layer := range layers {
+				stat, err := os.Stat(filepath.Join(layer, path))
+				if err != nil && !os.IsNotExist(err) {
+					return err
+				}
+				if err == nil {
+					// The file existed in the top layer, so that's a modification
+
+					// However, if it's a directory, maybe it wasn't actually modified.
+					// If you modify /foo/bar/baz, then /foo will be part of the changed files only because it's the parent of bar
+					if stat.IsDir() && f.IsDir() {
+						if f.Size() == stat.Size() && f.Mode() == stat.Mode() && sameFsTime(f.ModTime(), stat.ModTime()) {
+							// Both directories are the same, don't record the change
+							return nil
+						}
+					}
+					change.Kind = ChangeModify
+					break
+				}
+			}
+		}
+
+		// If /foo/bar/file.txt is modified, then /foo/bar must be part of the changed files.
+		// This block is here to ensure the change is recorded even if the
+		// modify time, mode and size of the parent directory in the rw and ro layers are all equal.
+		// Check https://github.com/docker/docker/pull/13590 for details.
+		if f.IsDir() {
+			changedDirs[path] = struct{}{}
+		}
+		if change.Kind == ChangeAdd || change.Kind == ChangeDelete {
+			parent := filepath.Dir(path)
+			if _, ok := changedDirs[parent]; !ok && parent != "/" {
+				changes = append(changes, Change{Path: parent, Kind: ChangeModify})
+				changedDirs[parent] = struct{}{}
+			}
+		}
+
+		// Record change
+		changes = append(changes, change)
+		return nil
+	})
+	if err != nil && !os.IsNotExist(err) {
+		return nil, err
+	}
+	return changes, nil
+}
+
+// FileInfo describes the information of a file.
+type FileInfo struct {
+	parent     *FileInfo
+	name       string
+	stat       *system.StatT
+	children   map[string]*FileInfo
+	capability []byte
+	added      bool
+}
+
+// LookUp looks up the file information of a file.
+func (info *FileInfo) LookUp(path string) *FileInfo {
+	// As this runs on the daemon side, file paths are OS specific.
+	parent := info
+	if path == string(os.PathSeparator) {
+		return info
+	}
+
+	pathElements := strings.Split(path, string(os.PathSeparator))
+	for _, elem := range pathElements {
+		if elem != "" {
+			child := parent.children[elem]
+			if child == nil {
+				return nil
+			}
+			parent = child
+		}
+	}
+	return parent
+}
+
+func (info *FileInfo) path() string {
+	if info.parent == nil {
+		// As this runs on the daemon side, file paths are OS specific.
+		return string(os.PathSeparator)
+	}
+	return filepath.Join(info.parent.path(), info.name)
+}
+
+func (info *FileInfo) addChanges(oldInfo *FileInfo, changes *[]Change) {
+
+	sizeAtEntry := len(*changes)
+
+	if oldInfo == nil {
+		// add
+		change := Change{
+			Path: info.path(),
+			Kind: ChangeAdd,
+		}
+		*changes = append(*changes, change)
+		info.added = true
+	}
+
+	// We make a copy so we can modify it to detect additions
+	// also, we only recurse on the old dir if the new info is a directory
+	// otherwise any previous delete/change is considered recursive
+	oldChildren := make(map[string]*FileInfo)
+	if oldInfo != nil && info.isDir() {
+		for k, v := range oldInfo.children {
+			oldChildren[k] = v
+		}
+	}
+
+	for name, newChild := range info.children {
+		oldChild, _ := oldChildren[name]
+		if oldChild != nil {
+			// change?
+			oldStat := oldChild.stat
+			newStat := newChild.stat
+			// Note: We can't compare inode or ctime or blocksize here, because these change
+			// when copying a file into a container. However, that is not generally a problem
+			// because any content change will change mtime, and any status change should
+			// be visible when actually comparing the stat fields. The only time this
+			// breaks down is if some code intentionally hides a change by setting
+			// back mtime
+			if statDifferent(oldStat, newStat) ||
+				bytes.Compare(oldChild.capability, newChild.capability) != 0 {
+				change := Change{
+					Path: newChild.path(),
+					Kind: ChangeModify,
+				}
+				*changes = append(*changes, change)
+				newChild.added = true
+			}
+
+			// Remove from copy so we can detect deletions
+			delete(oldChildren, name)
+		}
+
+		newChild.addChanges(oldChild, changes)
+	}
+	for _, oldChild := range oldChildren {
+		// delete
+		change := Change{
+			Path: oldChild.path(),
+			Kind: ChangeDelete,
+		}
+		*changes = append(*changes, change)
+	}
+
+	// If there were changes inside this directory, we need to add it, even if the directory
+	// itself wasn't changed. This is needed to properly save and restore filesystem permissions.
+	// As this runs on the daemon side, file paths are OS specific.
+	if len(*changes) > sizeAtEntry && info.isDir() && !info.added && info.path() != string(os.PathSeparator) {
+		change := Change{
+			Path: info.path(),
+			Kind: ChangeModify,
+		}
+		// Let's insert the directory entry before the recently added entries located inside this dir
+		*changes = append(*changes, change) // just to resize the slice, will be overwritten
+		copy((*changes)[sizeAtEntry+1:], (*changes)[sizeAtEntry:])
+		(*changes)[sizeAtEntry] = change
+	}
+
+}
+
+// Changes add changes to file information.
+func (info *FileInfo) Changes(oldInfo *FileInfo) []Change {
+	var changes []Change
+
+	info.addChanges(oldInfo, &changes)
+
+	return changes
+}
+
+func newRootFileInfo() *FileInfo {
+	// As this runs on the daemon side, file paths are OS specific.
+	root := &FileInfo{
+		name:     string(os.PathSeparator),
+		children: make(map[string]*FileInfo),
+	}
+	return root
+}
+
+// ChangesDirs compares two directories and generates an array of Change objects describing the changes.
+// If oldDir is "", then all files in newDir will be Add-Changes.
+func ChangesDirs(newDir, oldDir string) ([]Change, error) {
+	var (
+		oldRoot, newRoot *FileInfo
+	)
+	if oldDir == "" {
+		emptyDir, err := ioutil.TempDir("", "empty")
+		if err != nil {
+			return nil, err
+		}
+		defer os.Remove(emptyDir)
+		oldDir = emptyDir
+	}
+	oldRoot, newRoot, err := collectFileInfoForChanges(oldDir, newDir)
+	if err != nil {
+		return nil, err
+	}
+
+	return newRoot.Changes(oldRoot), nil
+}
+
+// ChangesSize calculates the size in bytes of the provided changes, based on newDir.
+func ChangesSize(newDir string, changes []Change) int64 {
+	var (
+		size int64
+		sf   = make(map[uint64]struct{})
+	)
+	for _, change := range changes {
+		if change.Kind == ChangeModify || change.Kind == ChangeAdd {
+			file := filepath.Join(newDir, change.Path)
+			fileInfo, err := os.Lstat(file)
+			if err != nil {
+				logrus.Errorf("Can not stat %q: %s", file, err)
+				continue
+			}
+
+			if fileInfo != nil && !fileInfo.IsDir() {
+				if hasHardlinks(fileInfo) {
+					inode := getIno(fileInfo)
+					if _, ok := sf[inode]; !ok {
+						size += fileInfo.Size()
+						sf[inode] = struct{}{}
+					}
+				} else {
+					size += fileInfo.Size()
+				}
+			}
+		}
+	}
+	return size
+}
+
+// ExportChanges produces an Archive from the provided changes, relative to dir.
+func ExportChanges(dir string, changes []Change, uidMaps, gidMaps []idtools.IDMap) (io.ReadCloser, error) {
+	reader, writer := io.Pipe()
+	go func() {
+		ta := &tarAppender{
+			TarWriter: tar.NewWriter(writer),
+			Buffer:    pools.BufioWriter32KPool.Get(nil),
+			SeenFiles: make(map[uint64]string),
+			UIDMaps:   uidMaps,
+			GIDMaps:   gidMaps,
+		}
+		// this buffer is needed for the duration of this piped stream
+		defer pools.BufioWriter32KPool.Put(ta.Buffer)
+
+		sort.Sort(changesByPath(changes))
+
+		// In general we log errors here but ignore them because
+		// during e.g. a diff operation the container can continue
+		// mutating the filesystem and we can see transient errors
+		// from this
+		for _, change := range changes {
+			if change.Kind == ChangeDelete {
+				whiteOutDir := filepath.Dir(change.Path)
+				whiteOutBase := filepath.Base(change.Path)
+				whiteOut := filepath.Join(whiteOutDir, WhiteoutPrefix+whiteOutBase)
+				timestamp := time.Now()
+				hdr := &tar.Header{
+					Name:       whiteOut[1:],
+					Size:       0,
+					ModTime:    timestamp,
+					AccessTime: timestamp,
+					ChangeTime: timestamp,
+				}
+				if err := ta.TarWriter.WriteHeader(hdr); err != nil {
+					logrus.Debugf("Can't write whiteout header: %s", err)
+				}
+			} else {
+				path := filepath.Join(dir, change.Path)
+				if err := ta.addTarFile(path, change.Path[1:]); err != nil {
+					logrus.Debugf("Can't add file %s to tar: %s", path, err)
+				}
+			}
+		}
+
+		// Make sure to check the error on Close.
+		if err := ta.TarWriter.Close(); err != nil {
+			logrus.Debugf("Can't close layer: %s", err)
+		}
+		if err := writer.Close(); err != nil {
+			logrus.Debugf("failed close Changes writer: %s", err)
+		}
+	}()
+	return reader, nil
+}

vendor/github.com/docker/docker/pkg/archive/changes_linux.go

@@ -0,0 +1,312 @@
+package archive
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"syscall"
+	"unsafe"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+// walker is used to implement collectFileInfoForChanges on linux. Where this
+// method in general returns the entire contents of two directory trees, we
+// optimize some FS calls out on linux. In particular, we take advantage of the
+// fact that getdents(2) returns the inode of each file in the directory being
+// walked, which, when walking two trees in parallel to generate a list of
+// changes, can be used to prune subtrees without ever having to lstat(2) them
+// directly. Eliminating stat calls in this way can save up to seconds on large
+// images.
+type walker struct {
+	dir1  string
+	dir2  string
+	root1 *FileInfo
+	root2 *FileInfo
+}
+
+// collectFileInfoForChanges returns a complete representation of the trees
+// rooted at dir1 and dir2, with one important exception: any subtree or
+// leaf where the inode and device numbers are an exact match between dir1
+// and dir2 will be pruned from the results. This method is *only* to be used
+// to generating a list of changes between the two directories, as it does not
+// reflect the full contents.
+func collectFileInfoForChanges(dir1, dir2 string) (*FileInfo, *FileInfo, error) {
+	w := &walker{
+		dir1:  dir1,
+		dir2:  dir2,
+		root1: newRootFileInfo(),
+		root2: newRootFileInfo(),
+	}
+
+	i1, err := os.Lstat(w.dir1)
+	if err != nil {
+		return nil, nil, err
+	}
+	i2, err := os.Lstat(w.dir2)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if err := w.walk("/", i1, i2); err != nil {
+		return nil, nil, err
+	}
+
+	return w.root1, w.root2, nil
+}
+
+// Given a FileInfo, its path info, and a reference to the root of the tree
+// being constructed, register this file with the tree.
+func walkchunk(path string, fi os.FileInfo, dir string, root *FileInfo) error {
+	if fi == nil {
+		return nil
+	}
+	parent := root.LookUp(filepath.Dir(path))
+	if parent == nil {
+		return fmt.Errorf("collectFileInfoForChanges: Unexpectedly no parent for %s", path)
+	}
+	info := &FileInfo{
+		name:     filepath.Base(path),
+		children: make(map[string]*FileInfo),
+		parent:   parent,
+	}
+	cpath := filepath.Join(dir, path)
+	stat, err := system.FromStatT(fi.Sys().(*syscall.Stat_t))
+	if err != nil {
+		return err
+	}
+	info.stat = stat
+	info.capability, _ = system.Lgetxattr(cpath, "security.capability") // lgetxattr(2): fs access
+	parent.children[info.name] = info
+	return nil
+}
+
+// Walk a subtree rooted at the same path in both trees being iterated. For
+// example, /docker/overlay/1234/a/b/c/d and /docker/overlay/8888/a/b/c/d
+func (w *walker) walk(path string, i1, i2 os.FileInfo) (err error) {
+	// Register these nodes with the return trees, unless we're still at the
+	// (already-created) roots:
+	if path != "/" {
+		if err := walkchunk(path, i1, w.dir1, w.root1); err != nil {
+			return err
+		}
+		if err := walkchunk(path, i2, w.dir2, w.root2); err != nil {
+			return err
+		}
+	}
+
+	is1Dir := i1 != nil && i1.IsDir()
+	is2Dir := i2 != nil && i2.IsDir()
+
+	sameDevice := false
+	if i1 != nil && i2 != nil {
+		si1 := i1.Sys().(*syscall.Stat_t)
+		si2 := i2.Sys().(*syscall.Stat_t)
+		if si1.Dev == si2.Dev {
+			sameDevice = true
+		}
+	}
+
+	// If these files are both non-existent, or leaves (non-dirs), we are done.
+	if !is1Dir && !is2Dir {
+		return nil
+	}
+
+	// Fetch the names of all the files contained in both directories being walked:
+	var names1, names2 []nameIno
+	if is1Dir {
+		names1, err = readdirnames(filepath.Join(w.dir1, path)) // getdents(2): fs access
+		if err != nil {
+			return err
+		}
+	}
+	if is2Dir {
+		names2, err = readdirnames(filepath.Join(w.dir2, path)) // getdents(2): fs access
+		if err != nil {
+			return err
+		}
+	}
+
+	// We have lists of the files contained in both parallel directories, sorted
+	// in the same order. Walk them in parallel, generating a unique merged list
+	// of all items present in either or both directories.
+	var names []string
+	ix1 := 0
+	ix2 := 0
+
+	for {
+		if ix1 >= len(names1) {
+			break
+		}
+		if ix2 >= len(names2) {
+			break
+		}
+
+		ni1 := names1[ix1]
+		ni2 := names2[ix2]
+
+		switch bytes.Compare([]byte(ni1.name), []byte(ni2.name)) {
+		case -1: // ni1 < ni2 -- advance ni1
+			// we will not encounter ni1 in names2
+			names = append(names, ni1.name)
+			ix1++
+		case 0: // ni1 == ni2
+			if ni1.ino != ni2.ino || !sameDevice {
+				names = append(names, ni1.name)
+			}
+			ix1++
+			ix2++
+		case 1: // ni1 > ni2 -- advance ni2
+			// we will not encounter ni2 in names1
+			names = append(names, ni2.name)
+			ix2++
+		}
+	}
+	for ix1 < len(names1) {
+		names = append(names, names1[ix1].name)
+		ix1++
+	}
+	for ix2 < len(names2) {
+		names = append(names, names2[ix2].name)
+		ix2++
+	}
+
+	// For each of the names present in either or both of the directories being
+	// iterated, stat the name under each root, and recurse the pair of them:
+	for _, name := range names {
+		fname := filepath.Join(path, name)
+		var cInfo1, cInfo2 os.FileInfo
+		if is1Dir {
+			cInfo1, err = os.Lstat(filepath.Join(w.dir1, fname)) // lstat(2): fs access
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+		}
+		if is2Dir {
+			cInfo2, err = os.Lstat(filepath.Join(w.dir2, fname)) // lstat(2): fs access
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+		}
+		if err = w.walk(fname, cInfo1, cInfo2); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// {name,inode} pairs used to support the early-pruning logic of the walker type
+type nameIno struct {
+	name string
+	ino  uint64
+}
+
+type nameInoSlice []nameIno
+
+func (s nameInoSlice) Len() int           { return len(s) }
+func (s nameInoSlice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s nameInoSlice) Less(i, j int) bool { return s[i].name < s[j].name }
+
+// readdirnames is a hacked-apart version of the Go stdlib code, exposing inode
+// numbers further up the stack when reading directory contents. Unlike
+// os.Readdirnames, which returns a list of filenames, this function returns a
+// list of {filename,inode} pairs.
+func readdirnames(dirname string) (names []nameIno, err error) {
+	var (
+		size = 100
+		buf  = make([]byte, 4096)
+		nbuf int
+		bufp int
+		nb   int
+	)
+
+	f, err := os.Open(dirname)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	names = make([]nameIno, 0, size) // Empty with room to grow.
+	for {
+		// Refill the buffer if necessary
+		if bufp >= nbuf {
+			bufp = 0
+			nbuf, err = syscall.ReadDirent(int(f.Fd()), buf) // getdents on linux
+			if nbuf < 0 {
+				nbuf = 0
+			}
+			if err != nil {
+				return nil, os.NewSyscallError("readdirent", err)
+			}
+			if nbuf <= 0 {
+				break // EOF
+			}
+		}
+
+		// Drain the buffer
+		nb, names = parseDirent(buf[bufp:nbuf], names)
+		bufp += nb
+	}
+
+	sl := nameInoSlice(names)
+	sort.Sort(sl)
+	return sl, nil
+}
+
+// parseDirent is a minor modification of syscall.ParseDirent (linux version)
+// which returns {name,inode} pairs instead of just names.
+func parseDirent(buf []byte, names []nameIno) (consumed int, newnames []nameIno) {
+	origlen := len(buf)
+	for len(buf) > 0 {
+		dirent := (*syscall.Dirent)(unsafe.Pointer(&buf[0]))
+		buf = buf[dirent.Reclen:]
+		if dirent.Ino == 0 { // File absent in directory.
+			continue
+		}
+		bytes := (*[10000]byte)(unsafe.Pointer(&dirent.Name[0]))
+		var name = string(bytes[0:clen(bytes[:])])
+		if name == "." || name == ".." { // Useless names
+			continue
+		}
+		names = append(names, nameIno{name, dirent.Ino})
+	}
+	return origlen - len(buf), names
+}
+
+func clen(n []byte) int {
+	for i := 0; i < len(n); i++ {
+		if n[i] == 0 {
+			return i
+		}
+	}
+	return len(n)
+}
+
+// OverlayChanges walks the path rw and determines changes for the files in the path,
+// with respect to the parent layers
+func OverlayChanges(layers []string, rw string) ([]Change, error) {
+	return changes(layers, rw, overlayDeletedFile, nil)
+}
+
+func overlayDeletedFile(root, path string, fi os.FileInfo) (string, error) {
+	if fi.Mode()&os.ModeCharDevice != 0 {
+		s := fi.Sys().(*syscall.Stat_t)
+		if major(uint64(s.Rdev)) == 0 && minor(uint64(s.Rdev)) == 0 {
+			return path, nil
+		}
+	}
+	if fi.Mode()&os.ModeDir != 0 {
+		opaque, err := system.Lgetxattr(filepath.Join(root, path), "trusted.overlay.opaque")
+		if err != nil {
+			return "", err
+		}
+		if len(opaque) == 1 && opaque[0] == 'y' {
+			return path, nil
+		}
+	}
+
+	return "", nil
+
+}

vendor/github.com/docker/docker/pkg/archive/changes_other.go

@@ -0,0 +1,97 @@
+// +build !linux
+
+package archive
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+func collectFileInfoForChanges(oldDir, newDir string) (*FileInfo, *FileInfo, error) {
+	var (
+		oldRoot, newRoot *FileInfo
+		err1, err2       error
+		errs             = make(chan error, 2)
+	)
+	go func() {
+		oldRoot, err1 = collectFileInfo(oldDir)
+		errs <- err1
+	}()
+	go func() {
+		newRoot, err2 = collectFileInfo(newDir)
+		errs <- err2
+	}()
+
+	// block until both routines have returned
+	for i := 0; i < 2; i++ {
+		if err := <-errs; err != nil {
+			return nil, nil, err
+		}
+	}
+
+	return oldRoot, newRoot, nil
+}
+
+func collectFileInfo(sourceDir string) (*FileInfo, error) {
+	root := newRootFileInfo()
+
+	err := filepath.Walk(sourceDir, func(path string, f os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Rebase path
+		relPath, err := filepath.Rel(sourceDir, path)
+		if err != nil {
+			return err
+		}
+
+		// As this runs on the daemon side, file paths are OS specific.
+		relPath = filepath.Join(string(os.PathSeparator), relPath)
+
+		// See https://github.com/golang/go/issues/9168 - bug in filepath.Join.
+		// Temporary workaround. If the returned path starts with two backslashes,
+		// trim it down to a single backslash. Only relevant on Windows.
+		if runtime.GOOS == "windows" {
+			if strings.HasPrefix(relPath, `\\`) {
+				relPath = relPath[1:]
+			}
+		}
+
+		if relPath == string(os.PathSeparator) {
+			return nil
+		}
+
+		parent := root.LookUp(filepath.Dir(relPath))
+		if parent == nil {
+			return fmt.Errorf("collectFileInfo: Unexpectedly no parent for %s", relPath)
+		}
+
+		info := &FileInfo{
+			name:     filepath.Base(relPath),
+			children: make(map[string]*FileInfo),
+			parent:   parent,
+		}
+
+		s, err := system.Lstat(path)
+		if err != nil {
+			return err
+		}
+		info.stat = s
+
+		info.capability, _ = system.Lgetxattr(path, "security.capability")
+
+		parent.children[info.name] = info
+
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return root, nil
+}

vendor/github.com/docker/docker/pkg/archive/changes_unix.go

@@ -0,0 +1,36 @@
+// +build !windows
+
+package archive
+
+import (
+	"os"
+	"syscall"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+func statDifferent(oldStat *system.StatT, newStat *system.StatT) bool {
+	// Don't look at size for dirs, its not a good measure of change
+	if oldStat.Mode() != newStat.Mode() ||
+		oldStat.UID() != newStat.UID() ||
+		oldStat.GID() != newStat.GID() ||
+		oldStat.Rdev() != newStat.Rdev() ||
+		// Don't look at size for dirs, its not a good measure of change
+		(oldStat.Mode()&syscall.S_IFDIR != syscall.S_IFDIR &&
+			(!sameFsTimeSpec(oldStat.Mtim(), newStat.Mtim()) || (oldStat.Size() != newStat.Size()))) {
+		return true
+	}
+	return false
+}
+
+func (info *FileInfo) isDir() bool {
+	return info.parent == nil || info.stat.Mode()&syscall.S_IFDIR != 0
+}
+
+func getIno(fi os.FileInfo) uint64 {
+	return uint64(fi.Sys().(*syscall.Stat_t).Ino)
+}
+
+func hasHardlinks(fi os.FileInfo) bool {
+	return fi.Sys().(*syscall.Stat_t).Nlink > 1
+}

vendor/github.com/docker/docker/pkg/archive/changes_windows.go

@@ -0,0 +1,30 @@
+package archive
+
+import (
+	"os"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+func statDifferent(oldStat *system.StatT, newStat *system.StatT) bool {
+
+	// Don't look at size for dirs, its not a good measure of change
+	if oldStat.ModTime() != newStat.ModTime() ||
+		oldStat.Mode() != newStat.Mode() ||
+		oldStat.Size() != newStat.Size() && !oldStat.IsDir() {
+		return true
+	}
+	return false
+}
+
+func (info *FileInfo) isDir() bool {
+	return info.parent == nil || info.stat.IsDir()
+}
+
+func getIno(fi os.FileInfo) (inode uint64) {
+	return
+}
+
+func hasHardlinks(fi os.FileInfo) bool {
+	return false
+}

vendor/github.com/docker/docker/pkg/archive/copy.go

@@ -0,0 +1,458 @@
+package archive
+
+import (
+	"archive/tar"
+	"errors"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/pkg/system"
+)
+
+// Errors used or returned by this file.
+var (
+	ErrNotDirectory      = errors.New("not a directory")
+	ErrDirNotExists      = errors.New("no such directory")
+	ErrCannotCopyDir     = errors.New("cannot copy directory")
+	ErrInvalidCopySource = errors.New("invalid copy source content")
+)
+
+// PreserveTrailingDotOrSeparator returns the given cleaned path (after
+// processing using any utility functions from the path or filepath stdlib
+// packages) and appends a trailing `/.` or `/` if its corresponding  original
+// path (from before being processed by utility functions from the path or
+// filepath stdlib packages) ends with a trailing `/.` or `/`. If the cleaned
+// path already ends in a `.` path segment, then another is not added. If the
+// clean path already ends in a path separator, then another is not added.
+func PreserveTrailingDotOrSeparator(cleanedPath, originalPath string) string {
+	// Ensure paths are in platform semantics
+	cleanedPath = normalizePath(cleanedPath)
+	originalPath = normalizePath(originalPath)
+
+	if !specifiesCurrentDir(cleanedPath) && specifiesCurrentDir(originalPath) {
+		if !hasTrailingPathSeparator(cleanedPath) {
+			// Add a separator if it doesn't already end with one (a cleaned
+			// path would only end in a separator if it is the root).
+			cleanedPath += string(filepath.Separator)
+		}
+		cleanedPath += "."
+	}
+
+	if !hasTrailingPathSeparator(cleanedPath) && hasTrailingPathSeparator(originalPath) {
+		cleanedPath += string(filepath.Separator)
+	}
+
+	return cleanedPath
+}
+
+// assertsDirectory returns whether the given path is
+// asserted to be a directory, i.e., the path ends with
+// a trailing '/' or `/.`, assuming a path separator of `/`.
+func assertsDirectory(path string) bool {
+	return hasTrailingPathSeparator(path) || specifiesCurrentDir(path)
+}
+
+// hasTrailingPathSeparator returns whether the given
+// path ends with the system's path separator character.
+func hasTrailingPathSeparator(path string) bool {
+	return len(path) > 0 && os.IsPathSeparator(path[len(path)-1])
+}
+
+// specifiesCurrentDir returns whether the given path specifies
+// a "current directory", i.e., the last path segment is `.`.
+func specifiesCurrentDir(path string) bool {
+	return filepath.Base(path) == "."
+}
+
+// SplitPathDirEntry splits the given path between its directory name and its
+// basename by first cleaning the path but preserves a trailing "." if the
+// original path specified the current directory.
+func SplitPathDirEntry(path string) (dir, base string) {
+	cleanedPath := filepath.Clean(normalizePath(path))
+
+	if specifiesCurrentDir(path) {
+		cleanedPath += string(filepath.Separator) + "."
+	}
+
+	return filepath.Dir(cleanedPath), filepath.Base(cleanedPath)
+}
+
+// TarResource archives the resource described by the given CopyInfo to a Tar
+// archive. A non-nil error is returned if sourcePath does not exist or is
+// asserted to be a directory but exists as another type of file.
+//
+// This function acts as a convenient wrapper around TarWithOptions, which
+// requires a directory as the source path. TarResource accepts either a
+// directory or a file path and correctly sets the Tar options.
+func TarResource(sourceInfo CopyInfo) (content io.ReadCloser, err error) {
+	return TarResourceRebase(sourceInfo.Path, sourceInfo.RebaseName)
+}
+
+// TarResourceRebase is like TarResource but renames the first path element of
+// items in the resulting tar archive to match the given rebaseName if not "".
+func TarResourceRebase(sourcePath, rebaseName string) (content io.ReadCloser, err error) {
+	sourcePath = normalizePath(sourcePath)
+	if _, err = os.Lstat(sourcePath); err != nil {
+		// Catches the case where the source does not exist or is not a
+		// directory if asserted to be a directory, as this also causes an
+		// error.
+		return
+	}
+
+	// Separate the source path between its directory and
+	// the entry in that directory which we are archiving.
+	sourceDir, sourceBase := SplitPathDirEntry(sourcePath)
+
+	filter := []string{sourceBase}
+
+	logrus.Debugf("copying %q from %q", sourceBase, sourceDir)
+
+	return TarWithOptions(sourceDir, &TarOptions{
+		Compression:      Uncompressed,
+		IncludeFiles:     filter,
+		IncludeSourceDir: true,
+		RebaseNames: map[string]string{
+			sourceBase: rebaseName,
+		},
+	})
+}
+
+// CopyInfo holds basic info about the source
+// or destination path of a copy operation.
+type CopyInfo struct {
+	Path       string
+	Exists     bool
+	IsDir      bool
+	RebaseName string
+}
+
+// CopyInfoSourcePath stats the given path to create a CopyInfo
+// struct representing that resource for the source of an archive copy
+// operation. The given path should be an absolute local path. A source path
+// has all symlinks evaluated that appear before the last path separator ("/"
+// on Unix). As it is to be a copy source, the path must exist.
+func CopyInfoSourcePath(path string, followLink bool) (CopyInfo, error) {
+	// normalize the file path and then evaluate the symbol link
+	// we will use the target file instead of the symbol link if
+	// followLink is set
+	path = normalizePath(path)
+
+	resolvedPath, rebaseName, err := ResolveHostSourcePath(path, followLink)
+	if err != nil {
+		return CopyInfo{}, err
+	}
+
+	stat, err := os.Lstat(resolvedPath)
+	if err != nil {
+		return CopyInfo{}, err
+	}
+
+	return CopyInfo{
+		Path:       resolvedPath,
+		Exists:     true,
+		IsDir:      stat.IsDir(),
+		RebaseName: rebaseName,
+	}, nil
+}
+
+// CopyInfoDestinationPath stats the given path to create a CopyInfo
+// struct representing that resource for the destination of an archive copy
+// operation. The given path should be an absolute local path.
+func CopyInfoDestinationPath(path string) (info CopyInfo, err error) {
+	maxSymlinkIter := 10 // filepath.EvalSymlinks uses 255, but 10 already seems like a lot.
+	path = normalizePath(path)
+	originalPath := path
+
+	stat, err := os.Lstat(path)
+
+	if err == nil && stat.Mode()&os.ModeSymlink == 0 {
+		// The path exists and is not a symlink.
+		return CopyInfo{
+			Path:   path,
+			Exists: true,
+			IsDir:  stat.IsDir(),
+		}, nil
+	}
+
+	// While the path is a symlink.
+	for n := 0; err == nil && stat.Mode()&os.ModeSymlink != 0; n++ {
+		if n > maxSymlinkIter {
+			// Don't follow symlinks more than this arbitrary number of times.
+			return CopyInfo{}, errors.New("too many symlinks in " + originalPath)
+		}
+
+		// The path is a symbolic link. We need to evaluate it so that the
+		// destination of the copy operation is the link target and not the
+		// link itself. This is notably different than CopyInfoSourcePath which
+		// only evaluates symlinks before the last appearing path separator.
+		// Also note that it is okay if the last path element is a broken
+		// symlink as the copy operation should create the target.
+		var linkTarget string
+
+		linkTarget, err = os.Readlink(path)
+		if err != nil {
+			return CopyInfo{}, err
+		}
+
+		if !system.IsAbs(linkTarget) {
+			// Join with the parent directory.
+			dstParent, _ := SplitPathDirEntry(path)
+			linkTarget = filepath.Join(dstParent, linkTarget)
+		}
+
+		path = linkTarget
+		stat, err = os.Lstat(path)
+	}
+
+	if err != nil {
+		// It's okay if the destination path doesn't exist. We can still
+		// continue the copy operation if the parent directory exists.
+		if !os.IsNotExist(err) {
+			return CopyInfo{}, err
+		}
+
+		// Ensure destination parent dir exists.
+		dstParent, _ := SplitPathDirEntry(path)
+
+		parentDirStat, err := os.Lstat(dstParent)
+		if err != nil {
+			return CopyInfo{}, err
+		}
+		if !parentDirStat.IsDir() {
+			return CopyInfo{}, ErrNotDirectory
+		}
+
+		return CopyInfo{Path: path}, nil
+	}
+
+	// The path exists after resolving symlinks.
+	return CopyInfo{
+		Path:   path,
+		Exists: true,
+		IsDir:  stat.IsDir(),
+	}, nil
+}
+
+// PrepareArchiveCopy prepares the given srcContent archive, which should
+// contain the archived resource described by srcInfo, to the destination
+// described by dstInfo. Returns the possibly modified content archive along
+// with the path to the destination directory which it should be extracted to.
+func PrepareArchiveCopy(srcContent io.Reader, srcInfo, dstInfo CopyInfo) (dstDir string, content io.ReadCloser, err error) {
+	// Ensure in platform semantics
+	srcInfo.Path = normalizePath(srcInfo.Path)
+	dstInfo.Path = normalizePath(dstInfo.Path)
+
+	// Separate the destination path between its directory and base
+	// components in case the source archive contents need to be rebased.
+	dstDir, dstBase := SplitPathDirEntry(dstInfo.Path)
+	_, srcBase := SplitPathDirEntry(srcInfo.Path)
+
+	switch {
+	case dstInfo.Exists && dstInfo.IsDir:
+		// The destination exists as a directory. No alteration
+		// to srcContent is needed as its contents can be
+		// simply extracted to the destination directory.
+		return dstInfo.Path, ioutil.NopCloser(srcContent), nil
+	case dstInfo.Exists && srcInfo.IsDir:
+		// The destination exists as some type of file and the source
+		// content is a directory. This is an error condition since
+		// you cannot copy a directory to an existing file location.
+		return "", nil, ErrCannotCopyDir
+	case dstInfo.Exists:
+		// The destination exists as some type of file and the source content
+		// is also a file. The source content entry will have to be renamed to
+		// have a basename which matches the destination path's basename.
+		if len(srcInfo.RebaseName) != 0 {
+			srcBase = srcInfo.RebaseName
+		}
+		return dstDir, RebaseArchiveEntries(srcContent, srcBase, dstBase), nil
+	case srcInfo.IsDir:
+		// The destination does not exist and the source content is an archive
+		// of a directory. The archive should be extracted to the parent of
+		// the destination path instead, and when it is, the directory that is
+		// created as a result should take the name of the destination path.
+		// The source content entries will have to be renamed to have a
+		// basename which matches the destination path's basename.
+		if len(srcInfo.RebaseName) != 0 {
+			srcBase = srcInfo.RebaseName
+		}
+		return dstDir, RebaseArchiveEntries(srcContent, srcBase, dstBase), nil
+	case assertsDirectory(dstInfo.Path):
+		// The destination does not exist and is asserted to be created as a
+		// directory, but the source content is not a directory. This is an
+		// error condition since you cannot create a directory from a file
+		// source.
+		return "", nil, ErrDirNotExists
+	default:
+		// The last remaining case is when the destination does not exist, is
+		// not asserted to be a directory, and the source content is not an
+		// archive of a directory. It this case, the destination file will need
+		// to be created when the archive is extracted and the source content
+		// entry will have to be renamed to have a basename which matches the
+		// destination path's basename.
+		if len(srcInfo.RebaseName) != 0 {
+			srcBase = srcInfo.RebaseName
+		}
+		return dstDir, RebaseArchiveEntries(srcContent, srcBase, dstBase), nil
+	}
+
+}
+
+// RebaseArchiveEntries rewrites the given srcContent archive replacing
+// an occurrence of oldBase with newBase at the beginning of entry names.
+func RebaseArchiveEntries(srcContent io.Reader, oldBase, newBase string) io.ReadCloser {
+	if oldBase == string(os.PathSeparator) {
+		// If oldBase specifies the root directory, use an empty string as
+		// oldBase instead so that newBase doesn't replace the path separator
+		// that all paths will start with.
+		oldBase = ""
+	}
+
+	rebased, w := io.Pipe()
+
+	go func() {
+		srcTar := tar.NewReader(srcContent)
+		rebasedTar := tar.NewWriter(w)
+
+		for {
+			hdr, err := srcTar.Next()
+			if err == io.EOF {
+				// Signals end of archive.
+				rebasedTar.Close()
+				w.Close()
+				return
+			}
+			if err != nil {
+				w.CloseWithError(err)
+				return
+			}
+
+			hdr.Name = strings.Replace(hdr.Name, oldBase, newBase, 1)
+
+			if err = rebasedTar.WriteHeader(hdr); err != nil {
+				w.CloseWithError(err)
+				return
+			}
+
+			if _, err = io.Copy(rebasedTar, srcTar); err != nil {
+				w.CloseWithError(err)
+				return
+			}
+		}
+	}()
+
+	return rebased
+}
+
+// CopyResource performs an archive copy from the given source path to the
+// given destination path. The source path MUST exist and the destination
+// path's parent directory must exist.
+func CopyResource(srcPath, dstPath string, followLink bool) error {
+	var (
+		srcInfo CopyInfo
+		err     error
+	)
+
+	// Ensure in platform semantics
+	srcPath = normalizePath(srcPath)
+	dstPath = normalizePath(dstPath)
+
+	// Clean the source and destination paths.
+	srcPath = PreserveTrailingDotOrSeparator(filepath.Clean(srcPath), srcPath)
+	dstPath = PreserveTrailingDotOrSeparator(filepath.Clean(dstPath), dstPath)
+
+	if srcInfo, err = CopyInfoSourcePath(srcPath, followLink); err != nil {
+		return err
+	}
+
+	content, err := TarResource(srcInfo)
+	if err != nil {
+		return err
+	}
+	defer content.Close()
+
+	return CopyTo(content, srcInfo, dstPath)
+}
+
+// CopyTo handles extracting the given content whose
+// entries should be sourced from srcInfo to dstPath.
+func CopyTo(content io.Reader, srcInfo CopyInfo, dstPath string) error {
+	// The destination path need not exist, but CopyInfoDestinationPath will
+	// ensure that at least the parent directory exists.
+	dstInfo, err := CopyInfoDestinationPath(normalizePath(dstPath))
+	if err != nil {
+		return err
+	}
+
+	dstDir, copyArchive, err := PrepareArchiveCopy(content, srcInfo, dstInfo)
+	if err != nil {
+		return err
+	}
+	defer copyArchive.Close()
+
+	options := &TarOptions{
+		NoLchown:             true,
+		NoOverwriteDirNonDir: true,
+	}
+
+	return Untar(copyArchive, dstDir, options)
+}
+
+// ResolveHostSourcePath decides real path need to be copied with parameters such as
+// whether to follow symbol link or not, if followLink is true, resolvedPath will return
+// link target of any symbol link file, else it will only resolve symlink of directory
+// but return symbol link file itself without resolving.
+func ResolveHostSourcePath(path string, followLink bool) (resolvedPath, rebaseName string, err error) {
+	if followLink {
+		resolvedPath, err = filepath.EvalSymlinks(path)
+		if err != nil {
+			return
+		}
+
+		resolvedPath, rebaseName = GetRebaseName(path, resolvedPath)
+	} else {
+		dirPath, basePath := filepath.Split(path)
+
+		// if not follow symbol link, then resolve symbol link of parent dir
+		var resolvedDirPath string
+		resolvedDirPath, err = filepath.EvalSymlinks(dirPath)
+		if err != nil {
+			return
+		}
+		// resolvedDirPath will have been cleaned (no trailing path separators) so
+		// we can manually join it with the base path element.
+		resolvedPath = resolvedDirPath + string(filepath.Separator) + basePath
+		if hasTrailingPathSeparator(path) && filepath.Base(path) != filepath.Base(resolvedPath) {
+			rebaseName = filepath.Base(path)
+		}
+	}
+	return resolvedPath, rebaseName, nil
+}
+
+// GetRebaseName normalizes and compares path and resolvedPath,
+// return completed resolved path and rebased file name
+func GetRebaseName(path, resolvedPath string) (string, string) {
+	// linkTarget will have been cleaned (no trailing path separators and dot) so
+	// we can manually join it with them
+	var rebaseName string
+	if specifiesCurrentDir(path) && !specifiesCurrentDir(resolvedPath) {
+		resolvedPath += string(filepath.Separator) + "."
+	}
+
+	if hasTrailingPathSeparator(path) && !hasTrailingPathSeparator(resolvedPath) {
+		resolvedPath += string(filepath.Separator)
+	}
+
+	if filepath.Base(path) != filepath.Base(resolvedPath) {
+		// In the case where the path had a trailing separator and a symlink
+		// evaluation has changed the last path component, we will need to
+		// rebase the name in the archive that is being copied to match the
+		// originally requested name.
+		rebaseName = filepath.Base(path)
+	}
+	return resolvedPath, rebaseName
+}

vendor/github.com/docker/docker/pkg/archive/copy_unix.go

@@ -0,0 +1,11 @@
+// +build !windows
+
+package archive
+
+import (
+	"path/filepath"
+)
+
+func normalizePath(path string) string {
+	return filepath.ToSlash(path)
+}

vendor/github.com/docker/docker/pkg/archive/copy_windows.go

@@ -0,0 +1,9 @@
+package archive
+
+import (
+	"path/filepath"
+)
+
+func normalizePath(path string) string {
+	return filepath.FromSlash(path)
+}

vendor/github.com/docker/docker/pkg/archive/diff.go

@@ -0,0 +1,279 @@
+package archive
+
+import (
+	"archive/tar"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/pkg/idtools"
+	"github.com/docker/docker/pkg/pools"
+	"github.com/docker/docker/pkg/system"
+)
+
+// UnpackLayer unpack `layer` to a `dest`. The stream `layer` can be
+// compressed or uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func UnpackLayer(dest string, layer io.Reader, options *TarOptions) (size int64, err error) {
+	tr := tar.NewReader(layer)
+	trBuf := pools.BufioReader32KPool.Get(tr)
+	defer pools.BufioReader32KPool.Put(trBuf)
+
+	var dirs []*tar.Header
+	unpackedPaths := make(map[string]struct{})
+
+	if options == nil {
+		options = &TarOptions{}
+	}
+	if options.ExcludePatterns == nil {
+		options.ExcludePatterns = []string{}
+	}
+	remappedRootUID, remappedRootGID, err := idtools.GetRootUIDGID(options.UIDMaps, options.GIDMaps)
+	if err != nil {
+		return 0, err
+	}
+
+	aufsTempdir := ""
+	aufsHardlinks := make(map[string]*tar.Header)
+
+	if options == nil {
+		options = &TarOptions{}
+	}
+	// Iterate through the files in the archive.
+	for {
+		hdr, err := tr.Next()
+		if err == io.EOF {
+			// end of tar archive
+			break
+		}
+		if err != nil {
+			return 0, err
+		}
+
+		size += hdr.Size
+
+		// Normalize name, for safety and for a simple is-root check
+		hdr.Name = filepath.Clean(hdr.Name)
+
+		// Windows does not support filenames with colons in them. Ignore
+		// these files. This is not a problem though (although it might
+		// appear that it is). Let's suppose a client is running docker pull.
+		// The daemon it points to is Windows. Would it make sense for the
+		// client to be doing a docker pull Ubuntu for example (which has files
+		// with colons in the name under /usr/share/man/man3)? No, absolutely
+		// not as it would really only make sense that they were pulling a
+		// Windows image. However, for development, it is necessary to be able
+		// to pull Linux images which are in the repository.
+		//
+		// TODO Windows. Once the registry is aware of what images are Windows-
+		// specific or Linux-specific, this warning should be changed to an error
+		// to cater for the situation where someone does manage to upload a Linux
+		// image but have it tagged as Windows inadvertently.
+		if runtime.GOOS == "windows" {
+			if strings.Contains(hdr.Name, ":") {
+				logrus.Warnf("Windows: Ignoring %s (is this a Linux image?)", hdr.Name)
+				continue
+			}
+		}
+
+		// Note as these operations are platform specific, so must the slash be.
+		if !strings.HasSuffix(hdr.Name, string(os.PathSeparator)) {
+			// Not the root directory, ensure that the parent directory exists.
+			// This happened in some tests where an image had a tarfile without any
+			// parent directories.
+			parent := filepath.Dir(hdr.Name)
+			parentPath := filepath.Join(dest, parent)
+
+			if _, err := os.Lstat(parentPath); err != nil && os.IsNotExist(err) {
+				err = system.MkdirAll(parentPath, 0600)
+				if err != nil {
+					return 0, err
+				}
+			}
+		}
+
+		// Skip AUFS metadata dirs
+		if strings.HasPrefix(hdr.Name, WhiteoutMetaPrefix) {
+			// Regular files inside /.wh..wh.plnk can be used as hardlink targets
+			// We don't want this directory, but we need the files in them so that
+			// such hardlinks can be resolved.
+			if strings.HasPrefix(hdr.Name, WhiteoutLinkDir) && hdr.Typeflag == tar.TypeReg {
+				basename := filepath.Base(hdr.Name)
+				aufsHardlinks[basename] = hdr
+				if aufsTempdir == "" {
+					if aufsTempdir, err = ioutil.TempDir("", "dockerplnk"); err != nil {
+						return 0, err
+					}
+					defer os.RemoveAll(aufsTempdir)
+				}
+				if err := createTarFile(filepath.Join(aufsTempdir, basename), dest, hdr, tr, true, nil, options.InUserNS); err != nil {
+					return 0, err
+				}
+			}
+
+			if hdr.Name != WhiteoutOpaqueDir {
+				continue
+			}
+		}
+		path := filepath.Join(dest, hdr.Name)
+		rel, err := filepath.Rel(dest, path)
+		if err != nil {
+			return 0, err
+		}
+
+		// Note as these operations are platform specific, so must the slash be.
+		if strings.HasPrefix(rel, ".."+string(os.PathSeparator)) {
+			return 0, breakoutError(fmt.Errorf("%q is outside of %q", hdr.Name, dest))
+		}
+		base := filepath.Base(path)
+
+		if strings.HasPrefix(base, WhiteoutPrefix) {
+			dir := filepath.Dir(path)
+			if base == WhiteoutOpaqueDir {
+				_, err := os.Lstat(dir)
+				if err != nil {
+					return 0, err
+				}
+				err = filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+					if err != nil {
+						if os.IsNotExist(err) {
+							err = nil // parent was deleted
+						}
+						return err
+					}
+					if path == dir {
+						return nil
+					}
+					if _, exists := unpackedPaths[path]; !exists {
+						err := os.RemoveAll(path)
+						return err
+					}
+					return nil
+				})
+				if err != nil {
+					return 0, err
+				}
+			} else {
+				originalBase := base[len(WhiteoutPrefix):]
+				originalPath := filepath.Join(dir, originalBase)
+				if err := os.RemoveAll(originalPath); err != nil {
+					return 0, err
+				}
+			}
+		} else {
+			// If path exits we almost always just want to remove and replace it.
+			// The only exception is when it is a directory *and* the file from
+			// the layer is also a directory. Then we want to merge them (i.e.
+			// just apply the metadata from the layer).
+			if fi, err := os.Lstat(path); err == nil {
+				if !(fi.IsDir() && hdr.Typeflag == tar.TypeDir) {
+					if err := os.RemoveAll(path); err != nil {
+						return 0, err
+					}
+				}
+			}
+
+			trBuf.Reset(tr)
+			srcData := io.Reader(trBuf)
+			srcHdr := hdr
+
+			// Hard links into /.wh..wh.plnk don't work, as we don't extract that directory, so
+			// we manually retarget these into the temporary files we extracted them into
+			if hdr.Typeflag == tar.TypeLink && strings.HasPrefix(filepath.Clean(hdr.Linkname), WhiteoutLinkDir) {
+				linkBasename := filepath.Base(hdr.Linkname)
+				srcHdr = aufsHardlinks[linkBasename]
+				if srcHdr == nil {
+					return 0, fmt.Errorf("Invalid aufs hardlink")
+				}
+				tmpFile, err := os.Open(filepath.Join(aufsTempdir, linkBasename))
+				if err != nil {
+					return 0, err
+				}
+				defer tmpFile.Close()
+				srcData = tmpFile
+			}
+
+			// if the options contain a uid & gid maps, convert header uid/gid
+			// entries using the maps such that lchown sets the proper mapped
+			// uid/gid after writing the file. We only perform this mapping if
+			// the file isn't already owned by the remapped root UID or GID, as
+			// that specific uid/gid has no mapping from container -> host, and
+			// those files already have the proper ownership for inside the
+			// container.
+			if srcHdr.Uid != remappedRootUID {
+				xUID, err := idtools.ToHost(srcHdr.Uid, options.UIDMaps)
+				if err != nil {
+					return 0, err
+				}
+				srcHdr.Uid = xUID
+			}
+			if srcHdr.Gid != remappedRootGID {
+				xGID, err := idtools.ToHost(srcHdr.Gid, options.GIDMaps)
+				if err != nil {
+					return 0, err
+				}
+				srcHdr.Gid = xGID
+			}
+			if err := createTarFile(path, dest, srcHdr, srcData, true, nil, options.InUserNS); err != nil {
+				return 0, err
+			}
+
+			// Directory mtimes must be handled at the end to avoid further
+			// file creation in them to modify the directory mtime
+			if hdr.Typeflag == tar.TypeDir {
+				dirs = append(dirs, hdr)
+			}
+			unpackedPaths[path] = struct{}{}
+		}
+	}
+
+	for _, hdr := range dirs {
+		path := filepath.Join(dest, hdr.Name)
+		if err := system.Chtimes(path, hdr.AccessTime, hdr.ModTime); err != nil {
+			return 0, err
+		}
+	}
+
+	return size, nil
+}
+
+// ApplyLayer parses a diff in the standard layer format from `layer`,
+// and applies it to the directory `dest`. The stream `layer` can be
+// compressed or uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func ApplyLayer(dest string, layer io.Reader) (int64, error) {
+	return applyLayerHandler(dest, layer, &TarOptions{}, true)
+}
+
+// ApplyUncompressedLayer parses a diff in the standard layer format from
+// `layer`, and applies it to the directory `dest`. The stream `layer`
+// can only be uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func ApplyUncompressedLayer(dest string, layer io.Reader, options *TarOptions) (int64, error) {
+	return applyLayerHandler(dest, layer, options, false)
+}
+
+// do the bulk load of ApplyLayer, but allow for not calling DecompressStream
+func applyLayerHandler(dest string, layer io.Reader, options *TarOptions, decompress bool) (int64, error) {
+	dest = filepath.Clean(dest)
+
+	// We need to be able to set any perms
+	oldmask, err := system.Umask(0)
+	if err != nil {
+		return 0, err
+	}
+	defer system.Umask(oldmask) // ignore err, ErrNotSupportedPlatform
+
+	if decompress {
+		layer, err = DecompressStream(layer)
+		if err != nil {
+			return 0, err
+		}
+	}
+	return UnpackLayer(dest, layer, options)
+}

vendor/github.com/docker/docker/pkg/archive/example_changes.go

@@ -0,0 +1,97 @@
+// +build ignore
+
+// Simple tool to create an archive stream from an old and new directory
+//
+// By default it will stream the comparison of two temporary directories with junk files
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/pkg/archive"
+)
+
+var (
+	flDebug  = flag.Bool("D", false, "debugging output")
+	flNewDir = flag.String("newdir", "", "")
+	flOldDir = flag.String("olddir", "", "")
+	log      = logrus.New()
+)
+
+func main() {
+	flag.Usage = func() {
+		fmt.Println("Produce a tar from comparing two directory paths. By default a demo tar is created of around 200 files (including hardlinks)")
+		fmt.Printf("%s [OPTIONS]\n", os.Args[0])
+		flag.PrintDefaults()
+	}
+	flag.Parse()
+	log.Out = os.Stderr
+	if (len(os.Getenv("DEBUG")) > 0) || *flDebug {
+		logrus.SetLevel(logrus.DebugLevel)
+	}
+	var newDir, oldDir string
+
+	if len(*flNewDir) == 0 {
+		var err error
+		newDir, err = ioutil.TempDir("", "docker-test-newDir")
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer os.RemoveAll(newDir)
+		if _, err := prepareUntarSourceDirectory(100, newDir, true); err != nil {
+			log.Fatal(err)
+		}
+	} else {
+		newDir = *flNewDir
+	}
+
+	if len(*flOldDir) == 0 {
+		oldDir, err := ioutil.TempDir("", "docker-test-oldDir")
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer os.RemoveAll(oldDir)
+	} else {
+		oldDir = *flOldDir
+	}
+
+	changes, err := archive.ChangesDirs(newDir, oldDir)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	a, err := archive.ExportChanges(newDir, changes)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer a.Close()
+
+	i, err := io.Copy(os.Stdout, a)
+	if err != nil && err != io.EOF {
+		log.Fatal(err)
+	}
+	fmt.Fprintf(os.Stderr, "wrote archive of %d bytes", i)
+}
+
+func prepareUntarSourceDirectory(numberOfFiles int, targetPath string, makeLinks bool) (int, error) {
+	fileData := []byte("fooo")
+	for n := 0; n < numberOfFiles; n++ {
+		fileName := fmt.Sprintf("file-%d", n)
+		if err := ioutil.WriteFile(path.Join(targetPath, fileName), fileData, 0700); err != nil {
+			return 0, err
+		}
+		if makeLinks {
+			if err := os.Link(path.Join(targetPath, fileName), path.Join(targetPath, fileName+"-link")); err != nil {
+				return 0, err
+			}
+		}
+	}
+	totalSize := numberOfFiles * len(fileData)
+	return totalSize, nil
+}

vendor/github.com/docker/docker/pkg/archive/time_linux.go

@@ -0,0 +1,16 @@
+package archive
+
+import (
+	"syscall"
+	"time"
+)
+
+func timeToTimespec(time time.Time) (ts syscall.Timespec) {
+	if time.IsZero() {
+		// Return UTIME_OMIT special value
+		ts.Sec = 0
+		ts.Nsec = ((1 << 30) - 2)
+		return
+	}
+	return syscall.NsecToTimespec(time.UnixNano())
+}

vendor/github.com/docker/docker/pkg/archive/time_unsupported.go

@@ -0,0 +1,16 @@
+// +build !linux
+
+package archive
+
+import (
+	"syscall"
+	"time"
+)
+
+func timeToTimespec(time time.Time) (ts syscall.Timespec) {
+	nsec := int64(0)
+	if !time.IsZero() {
+		nsec = time.UnixNano()
+	}
+	return syscall.NsecToTimespec(nsec)
+}

vendor/github.com/docker/docker/pkg/archive/whiteouts.go

@@ -0,0 +1,23 @@
+package archive
+
+// Whiteouts are files with a special meaning for the layered filesystem.
+// Docker uses AUFS whiteout files inside exported archives. In other
+// filesystems these files are generated/handled on tar creation/extraction.
+
+// WhiteoutPrefix prefix means file is a whiteout. If this is followed by a
+// filename this means that file has been removed from the base layer.
+const WhiteoutPrefix = ".wh."
+
+// WhiteoutMetaPrefix prefix means whiteout has a special meaning and is not
+// for removing an actual file. Normally these files are excluded from exported
+// archives.
+const WhiteoutMetaPrefix = WhiteoutPrefix + WhiteoutPrefix
+
+// WhiteoutLinkDir is a directory AUFS uses for storing hardlink links to other
+// layers. Normally these should not go into exported archives and all changed
+// hardlinks should be copied to the top layer.
+const WhiteoutLinkDir = WhiteoutMetaPrefix + "plnk"
+
+// WhiteoutOpaqueDir file means directory has been made opaque - meaning
+// readdir calls to this directory do not follow to lower layers.
+const WhiteoutOpaqueDir = WhiteoutMetaPrefix + ".opq"

vendor/github.com/docker/docker/pkg/archive/wrap.go

@@ -0,0 +1,59 @@
+package archive
+
+import (
+	"archive/tar"
+	"bytes"
+	"io"
+)
+
+// Generate generates a new archive from the content provided
+// as input.
+//
+// `files` is a sequence of path/content pairs. A new file is
+// added to the archive for each pair.
+// If the last pair is incomplete, the file is created with an
+// empty content. For example:
+//
+// Generate("foo.txt", "hello world", "emptyfile")
+//
+// The above call will return an archive with 2 files:
+//  * ./foo.txt with content "hello world"
+//  * ./empty with empty content
+//
+// FIXME: stream content instead of buffering
+// FIXME: specify permissions and other archive metadata
+func Generate(input ...string) (io.Reader, error) {
+	files := parseStringPairs(input...)
+	buf := new(bytes.Buffer)
+	tw := tar.NewWriter(buf)
+	for _, file := range files {
+		name, content := file[0], file[1]
+		hdr := &tar.Header{
+			Name: name,
+			Size: int64(len(content)),
+		}
+		if err := tw.WriteHeader(hdr); err != nil {
+			return nil, err
+		}
+		if _, err := tw.Write([]byte(content)); err != nil {
+			return nil, err
+		}
+	}
+	if err := tw.Close(); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}
+
+func parseStringPairs(input ...string) (output [][2]string) {
+	output = make([][2]string, 0, len(input)/2+1)
+	for i := 0; i < len(input); i += 2 {
+		var pair [2]string
+		pair[0] = input[i]
+		if i+1 < len(input) {
+			pair[1] = input[i+1]
+		}
+		output = append(output, pair)
+	}
+	return
+}

vendor/github.com/docker/docker/pkg/fileutils/fileutils.go

@@ -0,0 +1,283 @@
+package fileutils
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"text/scanner"
+
+	"github.com/Sirupsen/logrus"
+)
+
+// exclusion returns true if the specified pattern is an exclusion
+func exclusion(pattern string) bool {
+	return pattern[0] == '!'
+}
+
+// empty returns true if the specified pattern is empty
+func empty(pattern string) bool {
+	return pattern == ""
+}
+
+// CleanPatterns takes a slice of patterns returns a new
+// slice of patterns cleaned with filepath.Clean, stripped
+// of any empty patterns and lets the caller know whether the
+// slice contains any exception patterns (prefixed with !).
+func CleanPatterns(patterns []string) ([]string, [][]string, bool, error) {
+	// Loop over exclusion patterns and:
+	// 1. Clean them up.
+	// 2. Indicate whether we are dealing with any exception rules.
+	// 3. Error if we see a single exclusion marker on its own (!).
+	cleanedPatterns := []string{}
+	patternDirs := [][]string{}
+	exceptions := false
+	for _, pattern := range patterns {
+		// Eliminate leading and trailing whitespace.
+		pattern = strings.TrimSpace(pattern)
+		if empty(pattern) {
+			continue
+		}
+		if exclusion(pattern) {
+			if len(pattern) == 1 {
+				return nil, nil, false, errors.New("Illegal exclusion pattern: !")
+			}
+			exceptions = true
+		}
+		pattern = filepath.Clean(pattern)
+		cleanedPatterns = append(cleanedPatterns, pattern)
+		if exclusion(pattern) {
+			pattern = pattern[1:]
+		}
+		patternDirs = append(patternDirs, strings.Split(pattern, string(os.PathSeparator)))
+	}
+
+	return cleanedPatterns, patternDirs, exceptions, nil
+}
+
+// Matches returns true if file matches any of the patterns
+// and isn't excluded by any of the subsequent patterns.
+func Matches(file string, patterns []string) (bool, error) {
+	file = filepath.Clean(file)
+
+	if file == "." {
+		// Don't let them exclude everything, kind of silly.
+		return false, nil
+	}
+
+	patterns, patDirs, _, err := CleanPatterns(patterns)
+	if err != nil {
+		return false, err
+	}
+
+	return OptimizedMatches(file, patterns, patDirs)
+}
+
+// OptimizedMatches is basically the same as fileutils.Matches() but optimized for archive.go.
+// It will assume that the inputs have been preprocessed and therefore the function
+// doesn't need to do as much error checking and clean-up. This was done to avoid
+// repeating these steps on each file being checked during the archive process.
+// The more generic fileutils.Matches() can't make these assumptions.
+func OptimizedMatches(file string, patterns []string, patDirs [][]string) (bool, error) {
+	matched := false
+	file = filepath.FromSlash(file)
+	parentPath := filepath.Dir(file)
+	parentPathDirs := strings.Split(parentPath, string(os.PathSeparator))
+
+	for i, pattern := range patterns {
+		negative := false
+
+		if exclusion(pattern) {
+			negative = true
+			pattern = pattern[1:]
+		}
+
+		match, err := regexpMatch(pattern, file)
+		if err != nil {
+			return false, fmt.Errorf("Error in pattern (%s): %s", pattern, err)
+		}
+
+		if !match && parentPath != "." {
+			// Check to see if the pattern matches one of our parent dirs.
+			if len(patDirs[i]) <= len(parentPathDirs) {
+				match, _ = regexpMatch(strings.Join(patDirs[i], string(os.PathSeparator)),
+					strings.Join(parentPathDirs[:len(patDirs[i])], string(os.PathSeparator)))
+			}
+		}
+
+		if match {
+			matched = !negative
+		}
+	}
+
+	if matched {
+		logrus.Debugf("Skipping excluded path: %s", file)
+	}
+
+	return matched, nil
+}
+
+// regexpMatch tries to match the logic of filepath.Match but
+// does so using regexp logic. We do this so that we can expand the
+// wildcard set to include other things, like "**" to mean any number
+// of directories.  This means that we should be backwards compatible
+// with filepath.Match(). We'll end up supporting more stuff, due to
+// the fact that we're using regexp, but that's ok - it does no harm.
+//
+// As per the comment in golangs filepath.Match, on Windows, escaping
+// is disabled. Instead, '\\' is treated as path separator.
+func regexpMatch(pattern, path string) (bool, error) {
+	regStr := "^"
+
+	// Do some syntax checking on the pattern.
+	// filepath's Match() has some really weird rules that are inconsistent
+	// so instead of trying to dup their logic, just call Match() for its
+	// error state and if there is an error in the pattern return it.
+	// If this becomes an issue we can remove this since its really only
+	// needed in the error (syntax) case - which isn't really critical.
+	if _, err := filepath.Match(pattern, path); err != nil {
+		return false, err
+	}
+
+	// Go through the pattern and convert it to a regexp.
+	// We use a scanner so we can support utf-8 chars.
+	var scan scanner.Scanner
+	scan.Init(strings.NewReader(pattern))
+
+	sl := string(os.PathSeparator)
+	escSL := sl
+	if sl == `\` {
+		escSL += `\`
+	}
+
+	for scan.Peek() != scanner.EOF {
+		ch := scan.Next()
+
+		if ch == '*' {
+			if scan.Peek() == '*' {
+				// is some flavor of "**"
+				scan.Next()
+
+				if scan.Peek() == scanner.EOF {
+					// is "**EOF" - to align with .gitignore just accept all
+					regStr += ".*"
+				} else {
+					// is "**"
+					regStr += "((.*" + escSL + ")|([^" + escSL + "]*))"
+				}
+
+				// Treat **/ as ** so eat the "/"
+				if string(scan.Peek()) == sl {
+					scan.Next()
+				}
+			} else {
+				// is "*" so map it to anything but "/"
+				regStr += "[^" + escSL + "]*"
+			}
+		} else if ch == '?' {
+			// "?" is any char except "/"
+			regStr += "[^" + escSL + "]"
+		} else if ch == '.' || ch == '$' {
+			// Escape some regexp special chars that have no meaning
+			// in golang's filepath.Match
+			regStr += `\` + string(ch)
+		} else if ch == '\\' {
+			// escape next char. Note that a trailing \ in the pattern
+			// will be left alone (but need to escape it)
+			if sl == `\` {
+				// On windows map "\" to "\\", meaning an escaped backslash,
+				// and then just continue because filepath.Match on
+				// Windows doesn't allow escaping at all
+				regStr += escSL
+				continue
+			}
+			if scan.Peek() != scanner.EOF {
+				regStr += `\` + string(scan.Next())
+			} else {
+				regStr += `\`
+			}
+		} else {
+			regStr += string(ch)
+		}
+	}
+
+	regStr += "$"
+
+	res, err := regexp.MatchString(regStr, path)
+
+	// Map regexp's error to filepath's so no one knows we're not using filepath
+	if err != nil {
+		err = filepath.ErrBadPattern
+	}
+
+	return res, err
+}
+
+// CopyFile copies from src to dst until either EOF is reached
+// on src or an error occurs. It verifies src exists and removes
+// the dst if it exists.
+func CopyFile(src, dst string) (int64, error) {
+	cleanSrc := filepath.Clean(src)
+	cleanDst := filepath.Clean(dst)
+	if cleanSrc == cleanDst {
+		return 0, nil
+	}
+	sf, err := os.Open(cleanSrc)
+	if err != nil {
+		return 0, err
+	}
+	defer sf.Close()
+	if err := os.Remove(cleanDst); err != nil && !os.IsNotExist(err) {
+		return 0, err
+	}
+	df, err := os.Create(cleanDst)
+	if err != nil {
+		return 0, err
+	}
+	defer df.Close()
+	return io.Copy(df, sf)
+}
+
+// ReadSymlinkedDirectory returns the target directory of a symlink.
+// The target of the symbolic link may not be a file.
+func ReadSymlinkedDirectory(path string) (string, error) {
+	var realPath string
+	var err error
+	if realPath, err = filepath.Abs(path); err != nil {
+		return "", fmt.Errorf("unable to get absolute path for %s: %s", path, err)
+	}
+	if realPath, err = filepath.EvalSymlinks(realPath); err != nil {
+		return "", fmt.Errorf("failed to canonicalise path for %s: %s", path, err)
+	}
+	realPathInfo, err := os.Stat(realPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to stat target '%s' of '%s': %s", realPath, path, err)
+	}
+	if !realPathInfo.Mode().IsDir() {
+		return "", fmt.Errorf("canonical path points to a file '%s'", realPath)
+	}
+	return realPath, nil
+}
+
+// CreateIfNotExists creates a file or a directory only if it does not already exist.
+func CreateIfNotExists(path string, isDir bool) error {
+	if _, err := os.Stat(path); err != nil {
+		if os.IsNotExist(err) {
+			if isDir {
+				return os.MkdirAll(path, 0755)
+			}
+			if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+				return err
+			}
+			f, err := os.OpenFile(path, os.O_CREATE, 0755)
+			if err != nil {
+				return err
+			}
+			f.Close()
+		}
+	}
+	return nil
+}

vendor/github.com/docker/docker/pkg/fileutils/fileutils_darwin.go

@@ -0,0 +1,27 @@
+package fileutils
+
+import (
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+)
+
+// GetTotalUsedFds returns the number of used File Descriptors by
+// executing `lsof -p PID`
+func GetTotalUsedFds() int {
+	pid := os.Getpid()
+
+	cmd := exec.Command("lsof", "-p", strconv.Itoa(pid))
+
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return -1
+	}
+
+	outputStr := strings.TrimSpace(string(output))
+
+	fds := strings.Split(outputStr, "\n")
+
+	return len(fds) - 1
+}

vendor/github.com/docker/docker/pkg/fileutils/fileutils_solaris.go

@@ -0,0 +1,7 @@
+package fileutils
+
+// GetTotalUsedFds Returns the number of used File Descriptors.
+// On Solaris these limits are per process and not systemwide
+func GetTotalUsedFds() int {
+	return -1
+}

vendor/github.com/docker/docker/pkg/fileutils/fileutils_unix.go

@@ -0,0 +1,22 @@
+// +build linux freebsd
+
+package fileutils
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"github.com/Sirupsen/logrus"
+)
+
+// GetTotalUsedFds Returns the number of used File Descriptors by
+// reading it via /proc filesystem.
+func GetTotalUsedFds() int {
+	if fds, err := ioutil.ReadDir(fmt.Sprintf("/proc/%d/fd", os.Getpid())); err != nil {
+		logrus.Errorf("Error opening /proc/%d/fd: %s", os.Getpid(), err)
+	} else {
+		return len(fds)
+	}
+	return -1
+}

vendor/github.com/docker/docker/pkg/fileutils/fileutils_windows.go

@@ -0,0 +1,7 @@
+package fileutils
+
+// GetTotalUsedFds Returns the number of used File Descriptors. Not supported
+// on Windows.
+func GetTotalUsedFds() int {
+	return -1
+}

vendor/github.com/docker/docker/pkg/idtools/idtools.go

@@ -0,0 +1,197 @@
+package idtools
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// IDMap contains a single entry for user namespace range remapping. An array
+// of IDMap entries represents the structure that will be provided to the Linux
+// kernel for creating a user namespace.
+type IDMap struct {
+	ContainerID int `json:"container_id"`
+	HostID      int `json:"host_id"`
+	Size        int `json:"size"`
+}
+
+type subIDRange struct {
+	Start  int
+	Length int
+}
+
+type ranges []subIDRange
+
+func (e ranges) Len() int           { return len(e) }
+func (e ranges) Swap(i, j int)      { e[i], e[j] = e[j], e[i] }
+func (e ranges) Less(i, j int) bool { return e[i].Start < e[j].Start }
+
+const (
+	subuidFileName string = "/etc/subuid"
+	subgidFileName string = "/etc/subgid"
+)
+
+// MkdirAllAs creates a directory (include any along the path) and then modifies
+// ownership to the requested uid/gid.  If the directory already exists, this
+// function will still change ownership to the requested uid/gid pair.
+func MkdirAllAs(path string, mode os.FileMode, ownerUID, ownerGID int) error {
+	return mkdirAs(path, mode, ownerUID, ownerGID, true, true)
+}
+
+// MkdirAllNewAs creates a directory (include any along the path) and then modifies
+// ownership ONLY of newly created directories to the requested uid/gid. If the
+// directories along the path exist, no change of ownership will be performed
+func MkdirAllNewAs(path string, mode os.FileMode, ownerUID, ownerGID int) error {
+	return mkdirAs(path, mode, ownerUID, ownerGID, true, false)
+}
+
+// MkdirAs creates a directory and then modifies ownership to the requested uid/gid.
+// If the directory already exists, this function still changes ownership
+func MkdirAs(path string, mode os.FileMode, ownerUID, ownerGID int) error {
+	return mkdirAs(path, mode, ownerUID, ownerGID, false, true)
+}
+
+// GetRootUIDGID retrieves the remapped root uid/gid pair from the set of maps.
+// If the maps are empty, then the root uid/gid will default to "real" 0/0
+func GetRootUIDGID(uidMap, gidMap []IDMap) (int, int, error) {
+	var uid, gid int
+
+	if uidMap != nil {
+		xUID, err := ToHost(0, uidMap)
+		if err != nil {
+			return -1, -1, err
+		}
+		uid = xUID
+	}
+	if gidMap != nil {
+		xGID, err := ToHost(0, gidMap)
+		if err != nil {
+			return -1, -1, err
+		}
+		gid = xGID
+	}
+	return uid, gid, nil
+}
+
+// ToContainer takes an id mapping, and uses it to translate a
+// host ID to the remapped ID. If no map is provided, then the translation
+// assumes a 1-to-1 mapping and returns the passed in id
+func ToContainer(hostID int, idMap []IDMap) (int, error) {
+	if idMap == nil {
+		return hostID, nil
+	}
+	for _, m := range idMap {
+		if (hostID >= m.HostID) && (hostID <= (m.HostID + m.Size - 1)) {
+			contID := m.ContainerID + (hostID - m.HostID)
+			return contID, nil
+		}
+	}
+	return -1, fmt.Errorf("Host ID %d cannot be mapped to a container ID", hostID)
+}
+
+// ToHost takes an id mapping and a remapped ID, and translates the
+// ID to the mapped host ID. If no map is provided, then the translation
+// assumes a 1-to-1 mapping and returns the passed in id #
+func ToHost(contID int, idMap []IDMap) (int, error) {
+	if idMap == nil {
+		return contID, nil
+	}
+	for _, m := range idMap {
+		if (contID >= m.ContainerID) && (contID <= (m.ContainerID + m.Size - 1)) {
+			hostID := m.HostID + (contID - m.ContainerID)
+			return hostID, nil
+		}
+	}
+	return -1, fmt.Errorf("Container ID %d cannot be mapped to a host ID", contID)
+}
+
+// CreateIDMappings takes a requested user and group name and
+// using the data from /etc/sub{uid,gid} ranges, creates the
+// proper uid and gid remapping ranges for that user/group pair
+func CreateIDMappings(username, groupname string) ([]IDMap, []IDMap, error) {
+	subuidRanges, err := parseSubuid(username)
+	if err != nil {
+		return nil, nil, err
+	}
+	subgidRanges, err := parseSubgid(groupname)
+	if err != nil {
+		return nil, nil, err
+	}
+	if len(subuidRanges) == 0 {
+		return nil, nil, fmt.Errorf("No subuid ranges found for user %q", username)
+	}
+	if len(subgidRanges) == 0 {
+		return nil, nil, fmt.Errorf("No subgid ranges found for group %q", groupname)
+	}
+
+	return createIDMap(subuidRanges), createIDMap(subgidRanges), nil
+}
+
+func createIDMap(subidRanges ranges) []IDMap {
+	idMap := []IDMap{}
+
+	// sort the ranges by lowest ID first
+	sort.Sort(subidRanges)
+	containerID := 0
+	for _, idrange := range subidRanges {
+		idMap = append(idMap, IDMap{
+			ContainerID: containerID,
+			HostID:      idrange.Start,
+			Size:        idrange.Length,
+		})
+		containerID = containerID + idrange.Length
+	}
+	return idMap
+}
+
+func parseSubuid(username string) (ranges, error) {
+	return parseSubidFile(subuidFileName, username)
+}
+
+func parseSubgid(username string) (ranges, error) {
+	return parseSubidFile(subgidFileName, username)
+}
+
+// parseSubidFile will read the appropriate file (/etc/subuid or /etc/subgid)
+// and return all found ranges for a specified username. If the special value
+// "ALL" is supplied for username, then all ranges in the file will be returned
+func parseSubidFile(path, username string) (ranges, error) {
+	var rangeList ranges
+
+	subidFile, err := os.Open(path)
+	if err != nil {
+		return rangeList, err
+	}
+	defer subidFile.Close()
+
+	s := bufio.NewScanner(subidFile)
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			return rangeList, err
+		}
+
+		text := strings.TrimSpace(s.Text())
+		if text == "" || strings.HasPrefix(text, "#") {
+			continue
+		}
+		parts := strings.Split(text, ":")
+		if len(parts) != 3 {
+			return rangeList, fmt.Errorf("Cannot parse subuid/gid information: Format not correct for %s file", path)
+		}
+		if parts[0] == username || username == "ALL" {
+			startid, err := strconv.Atoi(parts[1])
+			if err != nil {
+				return rangeList, fmt.Errorf("String to int conversion failed during subuid/gid parsing of %s: %v", path, err)
+			}
+			length, err := strconv.Atoi(parts[2])
+			if err != nil {
+				return rangeList, fmt.Errorf("String to int conversion failed during subuid/gid parsing of %s: %v", path, err)
+			}
+			rangeList = append(rangeList, subIDRange{startid, length})
+		}
+	}
+	return rangeList, nil
+}

vendor/github.com/docker/docker/pkg/idtools/idtools_unix.go

@@ -0,0 +1,207 @@
+// +build !windows
+
+package idtools
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"github.com/docker/docker/pkg/system"
+	"github.com/opencontainers/runc/libcontainer/user"
+)
+
+var (
+	entOnce   sync.Once
+	getentCmd string
+)
+
+func mkdirAs(path string, mode os.FileMode, ownerUID, ownerGID int, mkAll, chownExisting bool) error {
+	// make an array containing the original path asked for, plus (for mkAll == true)
+	// all path components leading up to the complete path that don't exist before we MkdirAll
+	// so that we can chown all of them properly at the end.  If chownExisting is false, we won't
+	// chown the full directory path if it exists
+	var paths []string
+	if _, err := os.Stat(path); err != nil && os.IsNotExist(err) {
+		paths = []string{path}
+	} else if err == nil && chownExisting {
+		if err := os.Chown(path, ownerUID, ownerGID); err != nil {
+			return err
+		}
+		// short-circuit--we were called with an existing directory and chown was requested
+		return nil
+	} else if err == nil {
+		// nothing to do; directory path fully exists already and chown was NOT requested
+		return nil
+	}
+
+	if mkAll {
+		// walk back to "/" looking for directories which do not exist
+		// and add them to the paths array for chown after creation
+		dirPath := path
+		for {
+			dirPath = filepath.Dir(dirPath)
+			if dirPath == "/" {
+				break
+			}
+			if _, err := os.Stat(dirPath); err != nil && os.IsNotExist(err) {
+				paths = append(paths, dirPath)
+			}
+		}
+		if err := system.MkdirAll(path, mode); err != nil && !os.IsExist(err) {
+			return err
+		}
+	} else {
+		if err := os.Mkdir(path, mode); err != nil && !os.IsExist(err) {
+			return err
+		}
+	}
+	// even if it existed, we will chown the requested path + any subpaths that
+	// didn't exist when we called MkdirAll
+	for _, pathComponent := range paths {
+		if err := os.Chown(pathComponent, ownerUID, ownerGID); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// CanAccess takes a valid (existing) directory and a uid, gid pair and determines
+// if that uid, gid pair has access (execute bit) to the directory
+func CanAccess(path string, uid, gid int) bool {
+	statInfo, err := system.Stat(path)
+	if err != nil {
+		return false
+	}
+	fileMode := os.FileMode(statInfo.Mode())
+	permBits := fileMode.Perm()
+	return accessible(statInfo.UID() == uint32(uid),
+		statInfo.GID() == uint32(gid), permBits)
+}
+
+func accessible(isOwner, isGroup bool, perms os.FileMode) bool {
+	if isOwner && (perms&0100 == 0100) {
+		return true
+	}
+	if isGroup && (perms&0010 == 0010) {
+		return true
+	}
+	if perms&0001 == 0001 {
+		return true
+	}
+	return false
+}
+
+// LookupUser uses traditional local system files lookup (from libcontainer/user) on a username,
+// followed by a call to `getent` for supporting host configured non-files passwd and group dbs
+func LookupUser(username string) (user.User, error) {
+	// first try a local system files lookup using existing capabilities
+	usr, err := user.LookupUser(username)
+	if err == nil {
+		return usr, nil
+	}
+	// local files lookup failed; attempt to call `getent` to query configured passwd dbs
+	usr, err = getentUser(fmt.Sprintf("%s %s", "passwd", username))
+	if err != nil {
+		return user.User{}, err
+	}
+	return usr, nil
+}
+
+// LookupUID uses traditional local system files lookup (from libcontainer/user) on a uid,
+// followed by a call to `getent` for supporting host configured non-files passwd and group dbs
+func LookupUID(uid int) (user.User, error) {
+	// first try a local system files lookup using existing capabilities
+	usr, err := user.LookupUid(uid)
+	if err == nil {
+		return usr, nil
+	}
+	// local files lookup failed; attempt to call `getent` to query configured passwd dbs
+	return getentUser(fmt.Sprintf("%s %d", "passwd", uid))
+}
+
+func getentUser(args string) (user.User, error) {
+	reader, err := callGetent(args)
+	if err != nil {
+		return user.User{}, err
+	}
+	users, err := user.ParsePasswd(reader)
+	if err != nil {
+		return user.User{}, err
+	}
+	if len(users) == 0 {
+		return user.User{}, fmt.Errorf("getent failed to find passwd entry for %q", strings.Split(args, " ")[1])
+	}
+	return users[0], nil
+}
+
+// LookupGroup uses traditional local system files lookup (from libcontainer/user) on a group name,
+// followed by a call to `getent` for supporting host configured non-files passwd and group dbs
+func LookupGroup(groupname string) (user.Group, error) {
+	// first try a local system files lookup using existing capabilities
+	group, err := user.LookupGroup(groupname)
+	if err == nil {
+		return group, nil
+	}
+	// local files lookup failed; attempt to call `getent` to query configured group dbs
+	return getentGroup(fmt.Sprintf("%s %s", "group", groupname))
+}
+
+// LookupGID uses traditional local system files lookup (from libcontainer/user) on a group ID,
+// followed by a call to `getent` for supporting host configured non-files passwd and group dbs
+func LookupGID(gid int) (user.Group, error) {
+	// first try a local system files lookup using existing capabilities
+	group, err := user.LookupGid(gid)
+	if err == nil {
+		return group, nil
+	}
+	// local files lookup failed; attempt to call `getent` to query configured group dbs
+	return getentGroup(fmt.Sprintf("%s %d", "group", gid))
+}
+
+func getentGroup(args string) (user.Group, error) {
+	reader, err := callGetent(args)
+	if err != nil {
+		return user.Group{}, err
+	}
+	groups, err := user.ParseGroup(reader)
+	if err != nil {
+		return user.Group{}, err
+	}
+	if len(groups) == 0 {
+		return user.Group{}, fmt.Errorf("getent failed to find groups entry for %q", strings.Split(args, " ")[1])
+	}
+	return groups[0], nil
+}
+
+func callGetent(args string) (io.Reader, error) {
+	entOnce.Do(func() { getentCmd, _ = resolveBinary("getent") })
+	// if no `getent` command on host, can't do anything else
+	if getentCmd == "" {
+		return nil, fmt.Errorf("")
+	}
+	out, err := execCmd(getentCmd, args)
+	if err != nil {
+		exitCode, errC := system.GetExitCode(err)
+		if errC != nil {
+			return nil, err
+		}
+		switch exitCode {
+		case 1:
+			return nil, fmt.Errorf("getent reported invalid parameters/database unknown")
+		case 2:
+			terms := strings.Split(args, " ")
+			return nil, fmt.Errorf("getent unable to find entry %q in %s database", terms[1], terms[0])
+		case 3:
+			return nil, fmt.Errorf("getent database doesn't support enumeration")
+		default:
+			return nil, err
+		}
+
+	}
+	return bytes.NewReader(out), nil
+}

vendor/github.com/docker/docker/pkg/idtools/idtools_windows.go

@@ -0,0 +1,25 @@
+// +build windows
+
+package idtools
+
+import (
+	"os"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+// Platforms such as Windows do not support the UID/GID concept. So make this
+// just a wrapper around system.MkdirAll.
+func mkdirAs(path string, mode os.FileMode, ownerUID, ownerGID int, mkAll, chownExisting bool) error {
+	if err := system.MkdirAll(path, mode); err != nil && !os.IsExist(err) {
+		return err
+	}
+	return nil
+}
+
+// CanAccess takes a valid (existing) directory and a uid, gid pair and determines
+// if that uid, gid pair has access (execute bit) to the directory
+// Windows does not require/support this function, so always return true
+func CanAccess(path string, uid, gid int) bool {
+	return true
+}

vendor/github.com/docker/docker/pkg/idtools/usergroupadd_linux.go

@@ -0,0 +1,164 @@
+package idtools
+
+import (
+	"fmt"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+// add a user and/or group to Linux /etc/passwd, /etc/group using standard
+// Linux distribution commands:
+// adduser --system --shell /bin/false --disabled-login --disabled-password --no-create-home --group <username>
+// useradd -r -s /bin/false <username>
+
+var (
+	once        sync.Once
+	userCommand string
+
+	cmdTemplates = map[string]string{
+		"adduser": "--system --shell /bin/false --no-create-home --disabled-login --disabled-password --group %s",
+		"useradd": "-r -s /bin/false %s",
+		"usermod": "-%s %d-%d %s",
+	}
+
+	idOutRegexp = regexp.MustCompile(`uid=([0-9]+).*gid=([0-9]+)`)
+	// default length for a UID/GID subordinate range
+	defaultRangeLen   = 65536
+	defaultRangeStart = 100000
+	userMod           = "usermod"
+)
+
+// AddNamespaceRangesUser takes a username and uses the standard system
+// utility to create a system user/group pair used to hold the
+// /etc/sub{uid,gid} ranges which will be used for user namespace
+// mapping ranges in containers.
+func AddNamespaceRangesUser(name string) (int, int, error) {
+	if err := addUser(name); err != nil {
+		return -1, -1, fmt.Errorf("Error adding user %q: %v", name, err)
+	}
+
+	// Query the system for the created uid and gid pair
+	out, err := execCmd("id", name)
+	if err != nil {
+		return -1, -1, fmt.Errorf("Error trying to find uid/gid for new user %q: %v", name, err)
+	}
+	matches := idOutRegexp.FindStringSubmatch(strings.TrimSpace(string(out)))
+	if len(matches) != 3 {
+		return -1, -1, fmt.Errorf("Can't find uid, gid from `id` output: %q", string(out))
+	}
+	uid, err := strconv.Atoi(matches[1])
+	if err != nil {
+		return -1, -1, fmt.Errorf("Can't convert found uid (%s) to int: %v", matches[1], err)
+	}
+	gid, err := strconv.Atoi(matches[2])
+	if err != nil {
+		return -1, -1, fmt.Errorf("Can't convert found gid (%s) to int: %v", matches[2], err)
+	}
+
+	// Now we need to create the subuid/subgid ranges for our new user/group (system users
+	// do not get auto-created ranges in subuid/subgid)
+
+	if err := createSubordinateRanges(name); err != nil {
+		return -1, -1, fmt.Errorf("Couldn't create subordinate ID ranges: %v", err)
+	}
+	return uid, gid, nil
+}
+
+func addUser(userName string) error {
+	once.Do(func() {
+		// set up which commands are used for adding users/groups dependent on distro
+		if _, err := resolveBinary("adduser"); err == nil {
+			userCommand = "adduser"
+		} else if _, err := resolveBinary("useradd"); err == nil {
+			userCommand = "useradd"
+		}
+	})
+	if userCommand == "" {
+		return fmt.Errorf("Cannot add user; no useradd/adduser binary found")
+	}
+	args := fmt.Sprintf(cmdTemplates[userCommand], userName)
+	out, err := execCmd(userCommand, args)
+	if err != nil {
+		return fmt.Errorf("Failed to add user with error: %v; output: %q", err, string(out))
+	}
+	return nil
+}
+
+func createSubordinateRanges(name string) error {
+
+	// first, we should verify that ranges weren't automatically created
+	// by the distro tooling
+	ranges, err := parseSubuid(name)
+	if err != nil {
+		return fmt.Errorf("Error while looking for subuid ranges for user %q: %v", name, err)
+	}
+	if len(ranges) == 0 {
+		// no UID ranges; let's create one
+		startID, err := findNextUIDRange()
+		if err != nil {
+			return fmt.Errorf("Can't find available subuid range: %v", err)
+		}
+		out, err := execCmd(userMod, fmt.Sprintf(cmdTemplates[userMod], "v", startID, startID+defaultRangeLen-1, name))
+		if err != nil {
+			return fmt.Errorf("Unable to add subuid range to user: %q; output: %s, err: %v", name, out, err)
+		}
+	}
+
+	ranges, err = parseSubgid(name)
+	if err != nil {
+		return fmt.Errorf("Error while looking for subgid ranges for user %q: %v", name, err)
+	}
+	if len(ranges) == 0 {
+		// no GID ranges; let's create one
+		startID, err := findNextGIDRange()
+		if err != nil {
+			return fmt.Errorf("Can't find available subgid range: %v", err)
+		}
+		out, err := execCmd(userMod, fmt.Sprintf(cmdTemplates[userMod], "w", startID, startID+defaultRangeLen-1, name))
+		if err != nil {
+			return fmt.Errorf("Unable to add subgid range to user: %q; output: %s, err: %v", name, out, err)
+		}
+	}
+	return nil
+}
+
+func findNextUIDRange() (int, error) {
+	ranges, err := parseSubuid("ALL")
+	if err != nil {
+		return -1, fmt.Errorf("Couldn't parse all ranges in /etc/subuid file: %v", err)
+	}
+	sort.Sort(ranges)
+	return findNextRangeStart(ranges)
+}
+
+func findNextGIDRange() (int, error) {
+	ranges, err := parseSubgid("ALL")
+	if err != nil {
+		return -1, fmt.Errorf("Couldn't parse all ranges in /etc/subgid file: %v", err)
+	}
+	sort.Sort(ranges)
+	return findNextRangeStart(ranges)
+}
+
+func findNextRangeStart(rangeList ranges) (int, error) {
+	startID := defaultRangeStart
+	for _, arange := range rangeList {
+		if wouldOverlap(arange, startID) {
+			startID = arange.Start + arange.Length
+		}
+	}
+	return startID, nil
+}
+
+func wouldOverlap(arange subIDRange, ID int) bool {
+	low := ID
+	high := ID + defaultRangeLen
+	if (low >= arange.Start && low <= arange.Start+arange.Length) ||
+		(high <= arange.Start+arange.Length && high >= arange.Start) {
+		return true
+	}
+	return false
+}

vendor/github.com/docker/docker/pkg/idtools/usergroupadd_unsupported.go

@@ -0,0 +1,12 @@
+// +build !linux
+
+package idtools
+
+import "fmt"
+
+// AddNamespaceRangesUser takes a name and finds an unused uid, gid pair
+// and calls the appropriate helper function to add the group and then
+// the user to the group in /etc/group and /etc/passwd respectively.
+func AddNamespaceRangesUser(name string) (int, int, error) {
+	return -1, -1, fmt.Errorf("No support for adding users or groups on this OS")
+}

vendor/github.com/docker/docker/pkg/idtools/utils_unix.go

@@ -0,0 +1,32 @@
+// +build !windows
+
+package idtools
+
+import (
+	"fmt"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+func resolveBinary(binname string) (string, error) {
+	binaryPath, err := exec.LookPath(binname)
+	if err != nil {
+		return "", err
+	}
+	resolvedPath, err := filepath.EvalSymlinks(binaryPath)
+	if err != nil {
+		return "", err
+	}
+	//only return no error if the final resolved binary basename
+	//matches what was searched for
+	if filepath.Base(resolvedPath) == binname {
+		return resolvedPath, nil
+	}
+	return "", fmt.Errorf("Binary %q does not resolve to a binary of that name in $PATH (%q)", binname, resolvedPath)
+}
+
+func execCmd(cmd, args string) ([]byte, error) {
+	execCmd := exec.Command(cmd, strings.Split(args, " ")...)
+	return execCmd.CombinedOutput()
+}

vendor/github.com/docker/docker/pkg/ioutils/buffer.go

@@ -0,0 +1,51 @@
+package ioutils
+
+import (
+	"errors"
+	"io"
+)
+
+var errBufferFull = errors.New("buffer is full")
+
+type fixedBuffer struct {
+	buf      []byte
+	pos      int
+	lastRead int
+}
+
+func (b *fixedBuffer) Write(p []byte) (int, error) {
+	n := copy(b.buf[b.pos:cap(b.buf)], p)
+	b.pos += n
+
+	if n < len(p) {
+		if b.pos == cap(b.buf) {
+			return n, errBufferFull
+		}
+		return n, io.ErrShortWrite
+	}
+	return n, nil
+}
+
+func (b *fixedBuffer) Read(p []byte) (int, error) {
+	n := copy(p, b.buf[b.lastRead:b.pos])
+	b.lastRead += n
+	return n, nil
+}
+
+func (b *fixedBuffer) Len() int {
+	return b.pos - b.lastRead
+}
+
+func (b *fixedBuffer) Cap() int {
+	return cap(b.buf)
+}
+
+func (b *fixedBuffer) Reset() {
+	b.pos = 0
+	b.lastRead = 0
+	b.buf = b.buf[:0]
+}
+
+func (b *fixedBuffer) String() string {
+	return string(b.buf[b.lastRead:b.pos])
+}

vendor/github.com/docker/docker/pkg/ioutils/bytespipe.go

@@ -0,0 +1,186 @@
+package ioutils
+
+import (
+	"errors"
+	"io"
+	"sync"
+)
+
+// maxCap is the highest capacity to use in byte slices that buffer data.
+const maxCap = 1e6
+
+// minCap is the lowest capacity to use in byte slices that buffer data
+const minCap = 64
+
+// blockThreshold is the minimum number of bytes in the buffer which will cause
+// a write to BytesPipe to block when allocating a new slice.
+const blockThreshold = 1e6
+
+var (
+	// ErrClosed is returned when Write is called on a closed BytesPipe.
+	ErrClosed = errors.New("write to closed BytesPipe")
+
+	bufPools     = make(map[int]*sync.Pool)
+	bufPoolsLock sync.Mutex
+)
+
+// BytesPipe is io.ReadWriteCloser which works similarly to pipe(queue).
+// All written data may be read at most once. Also, BytesPipe allocates
+// and releases new byte slices to adjust to current needs, so the buffer
+// won't be overgrown after peak loads.
+type BytesPipe struct {
+	mu       sync.Mutex
+	wait     *sync.Cond
+	buf      []*fixedBuffer
+	bufLen   int
+	closeErr error // error to return from next Read. set to nil if not closed.
+}
+
+// NewBytesPipe creates new BytesPipe, initialized by specified slice.
+// If buf is nil, then it will be initialized with slice which cap is 64.
+// buf will be adjusted in a way that len(buf) == 0, cap(buf) == cap(buf).
+func NewBytesPipe() *BytesPipe {
+	bp := &BytesPipe{}
+	bp.buf = append(bp.buf, getBuffer(minCap))
+	bp.wait = sync.NewCond(&bp.mu)
+	return bp
+}
+
+// Write writes p to BytesPipe.
+// It can allocate new []byte slices in a process of writing.
+func (bp *BytesPipe) Write(p []byte) (int, error) {
+	bp.mu.Lock()
+
+	written := 0
+loop0:
+	for {
+		if bp.closeErr != nil {
+			bp.mu.Unlock()
+			return written, ErrClosed
+		}
+
+		if len(bp.buf) == 0 {
+			bp.buf = append(bp.buf, getBuffer(64))
+		}
+		// get the last buffer
+		b := bp.buf[len(bp.buf)-1]
+
+		n, err := b.Write(p)
+		written += n
+		bp.bufLen += n
+
+		// errBufferFull is an error we expect to get if the buffer is full
+		if err != nil && err != errBufferFull {
+			bp.wait.Broadcast()
+			bp.mu.Unlock()
+			return written, err
+		}
+
+		// if there was enough room to write all then break
+		if len(p) == n {
+			break
+		}
+
+		// more data: write to the next slice
+		p = p[n:]
+
+		// make sure the buffer doesn't grow too big from this write
+		for bp.bufLen >= blockThreshold {
+			bp.wait.Wait()
+			if bp.closeErr != nil {
+				continue loop0
+			}
+		}
+
+		// add new byte slice to the buffers slice and continue writing
+		nextCap := b.Cap() * 2
+		if nextCap > maxCap {
+			nextCap = maxCap
+		}
+		bp.buf = append(bp.buf, getBuffer(nextCap))
+	}
+	bp.wait.Broadcast()
+	bp.mu.Unlock()
+	return written, nil
+}
+
+// CloseWithError causes further reads from a BytesPipe to return immediately.
+func (bp *BytesPipe) CloseWithError(err error) error {
+	bp.mu.Lock()
+	if err != nil {
+		bp.closeErr = err
+	} else {
+		bp.closeErr = io.EOF
+	}
+	bp.wait.Broadcast()
+	bp.mu.Unlock()
+	return nil
+}
+
+// Close causes further reads from a BytesPipe to return immediately.
+func (bp *BytesPipe) Close() error {
+	return bp.CloseWithError(nil)
+}
+
+// Read reads bytes from BytesPipe.
+// Data could be read only once.
+func (bp *BytesPipe) Read(p []byte) (n int, err error) {
+	bp.mu.Lock()
+	if bp.bufLen == 0 {
+		if bp.closeErr != nil {
+			bp.mu.Unlock()
+			return 0, bp.closeErr
+		}
+		bp.wait.Wait()
+		if bp.bufLen == 0 && bp.closeErr != nil {
+			err := bp.closeErr
+			bp.mu.Unlock()
+			return 0, err
+		}
+	}
+
+	for bp.bufLen > 0 {
+		b := bp.buf[0]
+		read, _ := b.Read(p) // ignore error since fixedBuffer doesn't really return an error
+		n += read
+		bp.bufLen -= read
+
+		if b.Len() == 0 {
+			// it's empty so return it to the pool and move to the next one
+			returnBuffer(b)
+			bp.buf[0] = nil
+			bp.buf = bp.buf[1:]
+		}
+
+		if len(p) == read {
+			break
+		}
+
+		p = p[read:]
+	}
+
+	bp.wait.Broadcast()
+	bp.mu.Unlock()
+	return
+}
+
+func returnBuffer(b *fixedBuffer) {
+	b.Reset()
+	bufPoolsLock.Lock()
+	pool := bufPools[b.Cap()]
+	bufPoolsLock.Unlock()
+	if pool != nil {
+		pool.Put(b)
+	}
+}
+
+func getBuffer(size int) *fixedBuffer {
+	bufPoolsLock.Lock()
+	pool, ok := bufPools[size]
+	if !ok {
+		pool = &sync.Pool{New: func() interface{} { return &fixedBuffer{buf: make([]byte, 0, size)} }}
+		bufPools[size] = pool
+	}
+	bufPoolsLock.Unlock()
+	return pool.Get().(*fixedBuffer)
+}

vendor/github.com/docker/docker/pkg/ioutils/fmt.go

@@ -0,0 +1,22 @@
+package ioutils
+
+import (
+	"fmt"
+	"io"
+)
+
+// FprintfIfNotEmpty prints the string value if it's not empty
+func FprintfIfNotEmpty(w io.Writer, format, value string) (int, error) {
+	if value != "" {
+		return fmt.Fprintf(w, format, value)
+	}
+	return 0, nil
+}
+
+// FprintfIfTrue prints the boolean value if it's true
+func FprintfIfTrue(w io.Writer, format string, ok bool) (int, error) {
+	if ok {
+		return fmt.Fprintf(w, format, ok)
+	}
+	return 0, nil
+}

vendor/github.com/docker/docker/pkg/ioutils/fswriters.go

@@ -0,0 +1,162 @@
+package ioutils
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+)
+
+// NewAtomicFileWriter returns WriteCloser so that writing to it writes to a
+// temporary file and closing it atomically changes the temporary file to
+// destination path. Writing and closing concurrently is not allowed.
+func NewAtomicFileWriter(filename string, perm os.FileMode) (io.WriteCloser, error) {
+	f, err := ioutil.TempFile(filepath.Dir(filename), ".tmp-"+filepath.Base(filename))
+	if err != nil {
+		return nil, err
+	}
+
+	abspath, err := filepath.Abs(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &atomicFileWriter{
+		f:    f,
+		fn:   abspath,
+		perm: perm,
+	}, nil
+}
+
+// AtomicWriteFile atomically writes data to a file named by filename.
+func AtomicWriteFile(filename string, data []byte, perm os.FileMode) error {
+	f, err := NewAtomicFileWriter(filename, perm)
+	if err != nil {
+		return err
+	}
+	n, err := f.Write(data)
+	if err == nil && n < len(data) {
+		err = io.ErrShortWrite
+		f.(*atomicFileWriter).writeErr = err
+	}
+	if err1 := f.Close(); err == nil {
+		err = err1
+	}
+	return err
+}
+
+type atomicFileWriter struct {
+	f        *os.File
+	fn       string
+	writeErr error
+	perm     os.FileMode
+}
+
+func (w *atomicFileWriter) Write(dt []byte) (int, error) {
+	n, err := w.f.Write(dt)
+	if err != nil {
+		w.writeErr = err
+	}
+	return n, err
+}
+
+func (w *atomicFileWriter) Close() (retErr error) {
+	defer func() {
+		if retErr != nil || w.writeErr != nil {
+			os.Remove(w.f.Name())
+		}
+	}()
+	if err := w.f.Sync(); err != nil {
+		w.f.Close()
+		return err
+	}
+	if err := w.f.Close(); err != nil {
+		return err
+	}
+	if err := os.Chmod(w.f.Name(), w.perm); err != nil {
+		return err
+	}
+	if w.writeErr == nil {
+		return os.Rename(w.f.Name(), w.fn)
+	}
+	return nil
+}
+
+// AtomicWriteSet is used to atomically write a set
+// of files and ensure they are visible at the same time.
+// Must be committed to a new directory.
+type AtomicWriteSet struct {
+	root string
+}
+
+// NewAtomicWriteSet creates a new atomic write set to
+// atomically create a set of files. The given directory
+// is used as the base directory for storing files before
+// commit. If no temporary directory is given the system
+// default is used.
+func NewAtomicWriteSet(tmpDir string) (*AtomicWriteSet, error) {
+	td, err := ioutil.TempDir(tmpDir, "write-set-")
+	if err != nil {
+		return nil, err
+	}
+
+	return &AtomicWriteSet{
+		root: td,
+	}, nil
+}
+
+// WriteFile writes a file to the set, guaranteeing the file
+// has been synced.
+func (ws *AtomicWriteSet) WriteFile(filename string, data []byte, perm os.FileMode) error {
+	f, err := ws.FileWriter(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
+	if err != nil {
+		return err
+	}
+	n, err := f.Write(data)
+	if err == nil && n < len(data) {
+		err = io.ErrShortWrite
+	}
+	if err1 := f.Close(); err == nil {
+		err = err1
+	}
+	return err
+}
+
+type syncFileCloser struct {
+	*os.File
+}
+
+func (w syncFileCloser) Close() error {
+	err := w.File.Sync()
+	if err1 := w.File.Close(); err == nil {
+		err = err1
+	}
+	return err
+}
+
+// FileWriter opens a file writer inside the set. The file
+// should be synced and closed before calling commit.
+func (ws *AtomicWriteSet) FileWriter(name string, flag int, perm os.FileMode) (io.WriteCloser, error) {
+	f, err := os.OpenFile(filepath.Join(ws.root, name), flag, perm)
+	if err != nil {
+		return nil, err
+	}
+	return syncFileCloser{f}, nil
+}
+
+// Cancel cancels the set and removes all temporary data
+// created in the set.
+func (ws *AtomicWriteSet) Cancel() error {
+	return os.RemoveAll(ws.root)
+}
+
+// Commit moves all created files to the target directory. The
+// target directory must not exist and the parent of the target
+// directory must exist.
+func (ws *AtomicWriteSet) Commit(target string) error {
+	return os.Rename(ws.root, target)
+}
+
+// String returns the location the set is writing to.
+func (ws *AtomicWriteSet) String() string {
+	return ws.root
+}

vendor/github.com/docker/docker/pkg/ioutils/multireader.go

@@ -0,0 +1,223 @@
+package ioutils
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+)
+
+type pos struct {
+	idx    int
+	offset int64
+}
+
+type multiReadSeeker struct {
+	readers []io.ReadSeeker
+	pos     *pos
+	posIdx  map[io.ReadSeeker]int
+}
+
+func (r *multiReadSeeker) Seek(offset int64, whence int) (int64, error) {
+	var tmpOffset int64
+	switch whence {
+	case os.SEEK_SET:
+		for i, rdr := range r.readers {
+			// get size of the current reader
+			s, err := rdr.Seek(0, os.SEEK_END)
+			if err != nil {
+				return -1, err
+			}
+
+			if offset > tmpOffset+s {
+				if i == len(r.readers)-1 {
+					rdrOffset := s + (offset - tmpOffset)
+					if _, err := rdr.Seek(rdrOffset, os.SEEK_SET); err != nil {
+						return -1, err
+					}
+					r.pos = &pos{i, rdrOffset}
+					return offset, nil
+				}
+
+				tmpOffset += s
+				continue
+			}
+
+			rdrOffset := offset - tmpOffset
+			idx := i
+
+			rdr.Seek(rdrOffset, os.SEEK_SET)
+			// make sure all following readers are at 0
+			for _, rdr := range r.readers[i+1:] {
+				rdr.Seek(0, os.SEEK_SET)
+			}
+
+			if rdrOffset == s && i != len(r.readers)-1 {
+				idx++
+				rdrOffset = 0
+			}
+			r.pos = &pos{idx, rdrOffset}
+			return offset, nil
+		}
+	case os.SEEK_END:
+		for _, rdr := range r.readers {
+			s, err := rdr.Seek(0, os.SEEK_END)
+			if err != nil {
+				return -1, err
+			}
+			tmpOffset += s
+		}
+		r.Seek(tmpOffset+offset, os.SEEK_SET)
+		return tmpOffset + offset, nil
+	case os.SEEK_CUR:
+		if r.pos == nil {
+			return r.Seek(offset, os.SEEK_SET)
+		}
+		// Just return the current offset
+		if offset == 0 {
+			return r.getCurOffset()
+		}
+
+		curOffset, err := r.getCurOffset()
+		if err != nil {
+			return -1, err
+		}
+		rdr, rdrOffset, err := r.getReaderForOffset(curOffset + offset)
+		if err != nil {
+			return -1, err
+		}
+
+		r.pos = &pos{r.posIdx[rdr], rdrOffset}
+		return curOffset + offset, nil
+	default:
+		return -1, fmt.Errorf("Invalid whence: %d", whence)
+	}
+
+	return -1, fmt.Errorf("Error seeking for whence: %d, offset: %d", whence, offset)
+}
+
+func (r *multiReadSeeker) getReaderForOffset(offset int64) (io.ReadSeeker, int64, error) {
+
+	var offsetTo int64
+
+	for _, rdr := range r.readers {
+		size, err := getReadSeekerSize(rdr)
+		if err != nil {
+			return nil, -1, err
+		}
+		if offsetTo+size > offset {
+			return rdr, offset - offsetTo, nil
+		}
+		if rdr == r.readers[len(r.readers)-1] {
+			return rdr, offsetTo + offset, nil
+		}
+		offsetTo += size
+	}
+
+	return nil, 0, nil
+}
+
+func (r *multiReadSeeker) getCurOffset() (int64, error) {
+	var totalSize int64
+	for _, rdr := range r.readers[:r.pos.idx+1] {
+		if r.posIdx[rdr] == r.pos.idx {
+			totalSize += r.pos.offset
+			break
+		}
+
+		size, err := getReadSeekerSize(rdr)
+		if err != nil {
+			return -1, fmt.Errorf("error getting seeker size: %v", err)
+		}
+		totalSize += size
+	}
+	return totalSize, nil
+}
+
+func (r *multiReadSeeker) getOffsetToReader(rdr io.ReadSeeker) (int64, error) {
+	var offset int64
+	for _, r := range r.readers {
+		if r == rdr {
+			break
+		}
+
+		size, err := getReadSeekerSize(rdr)
+		if err != nil {
+			return -1, err
+		}
+		offset += size
+	}
+	return offset, nil
+}
+
+func (r *multiReadSeeker) Read(b []byte) (int, error) {
+	if r.pos == nil {
+		r.pos = &pos{0, 0}
+	}
+
+	bLen := int64(len(b))
+	buf := bytes.NewBuffer(nil)
+	var rdr io.ReadSeeker
+
+	for _, rdr = range r.readers[r.pos.idx:] {
+		readBytes, err := io.CopyN(buf, rdr, bLen)
+		if err != nil && err != io.EOF {
+			return -1, err
+		}
+		bLen -= readBytes
+
+		if bLen == 0 {
+			break
+		}
+	}
+
+	rdrPos, err := rdr.Seek(0, os.SEEK_CUR)
+	if err != nil {
+		return -1, err
+	}
+	r.pos = &pos{r.posIdx[rdr], rdrPos}
+	return buf.Read(b)
+}
+
+func getReadSeekerSize(rdr io.ReadSeeker) (int64, error) {
+	// save the current position
+	pos, err := rdr.Seek(0, os.SEEK_CUR)
+	if err != nil {
+		return -1, err
+	}
+
+	// get the size
+	size, err := rdr.Seek(0, os.SEEK_END)
+	if err != nil {
+		return -1, err
+	}
+
+	// reset the position
+	if _, err := rdr.Seek(pos, os.SEEK_SET); err != nil {
+		return -1, err
+	}
+	return size, nil
+}
+
+// MultiReadSeeker returns a ReadSeeker that's the logical concatenation of the provided
+// input readseekers. After calling this method the initial position is set to the
+// beginning of the first ReadSeeker. At the end of a ReadSeeker, Read always advances
+// to the beginning of the next ReadSeeker and returns EOF at the end of the last ReadSeeker.
+// Seek can be used over the sum of lengths of all readseekers.
+//
+// When a MultiReadSeeker is used, no Read and Seek operations should be made on
+// its ReadSeeker components. Also, users should make no assumption on the state
+// of individual readseekers while the MultiReadSeeker is used.
+func MultiReadSeeker(readers ...io.ReadSeeker) io.ReadSeeker {
+	if len(readers) == 1 {
+		return readers[0]
+	}
+	idx := make(map[io.ReadSeeker]int)
+	for i, rdr := range readers {
+		idx[rdr] = i
+	}
+	return &multiReadSeeker{
+		readers: readers,
+		posIdx:  idx,
+	}
+}

vendor/github.com/docker/docker/pkg/ioutils/readers.go

@@ -0,0 +1,154 @@
+package ioutils
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"io"
+
+	"golang.org/x/net/context"
+)
+
+type readCloserWrapper struct {
+	io.Reader
+	closer func() error
+}
+
+func (r *readCloserWrapper) Close() error {
+	return r.closer()
+}
+
+// NewReadCloserWrapper returns a new io.ReadCloser.
+func NewReadCloserWrapper(r io.Reader, closer func() error) io.ReadCloser {
+	return &readCloserWrapper{
+		Reader: r,
+		closer: closer,
+	}
+}
+
+type readerErrWrapper struct {
+	reader io.Reader
+	closer func()
+}
+
+func (r *readerErrWrapper) Read(p []byte) (int, error) {
+	n, err := r.reader.Read(p)
+	if err != nil {
+		r.closer()
+	}
+	return n, err
+}
+
+// NewReaderErrWrapper returns a new io.Reader.
+func NewReaderErrWrapper(r io.Reader, closer func()) io.Reader {
+	return &readerErrWrapper{
+		reader: r,
+		closer: closer,
+	}
+}
+
+// HashData returns the sha256 sum of src.
+func HashData(src io.Reader) (string, error) {
+	h := sha256.New()
+	if _, err := io.Copy(h, src); err != nil {
+		return "", err
+	}
+	return "sha256:" + hex.EncodeToString(h.Sum(nil)), nil
+}
+
+// OnEOFReader wraps an io.ReadCloser and a function
+// the function will run at the end of file or close the file.
+type OnEOFReader struct {
+	Rc io.ReadCloser
+	Fn func()
+}
+
+func (r *OnEOFReader) Read(p []byte) (n int, err error) {
+	n, err = r.Rc.Read(p)
+	if err == io.EOF {
+		r.runFunc()
+	}
+	return
+}
+
+// Close closes the file and run the function.
+func (r *OnEOFReader) Close() error {
+	err := r.Rc.Close()
+	r.runFunc()
+	return err
+}
+
+func (r *OnEOFReader) runFunc() {
+	if fn := r.Fn; fn != nil {
+		fn()
+		r.Fn = nil
+	}
+}
+
+// cancelReadCloser wraps an io.ReadCloser with a context for cancelling read
+// operations.
+type cancelReadCloser struct {
+	cancel func()
+	pR     *io.PipeReader // Stream to read from
+	pW     *io.PipeWriter
+}
+
+// NewCancelReadCloser creates a wrapper that closes the ReadCloser when the
+// context is cancelled. The returned io.ReadCloser must be closed when it is
+// no longer needed.
+func NewCancelReadCloser(ctx context.Context, in io.ReadCloser) io.ReadCloser {
+	pR, pW := io.Pipe()
+
+	// Create a context used to signal when the pipe is closed
+	doneCtx, cancel := context.WithCancel(context.Background())
+
+	p := &cancelReadCloser{
+		cancel: cancel,
+		pR:     pR,
+		pW:     pW,
+	}
+
+	go func() {
+		_, err := io.Copy(pW, in)
+		select {
+		case <-ctx.Done():
+			// If the context was closed, p.closeWithError
+			// was already called. Calling it again would
+			// change the error that Read returns.
+		default:
+			p.closeWithError(err)
+		}
+		in.Close()
+	}()
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				p.closeWithError(ctx.Err())
+			case <-doneCtx.Done():
+				return
+			}
+		}
+	}()
+
+	return p
+}
+
+// Read wraps the Read method of the pipe that provides data from the wrapped
+// ReadCloser.
+func (p *cancelReadCloser) Read(buf []byte) (n int, err error) {
+	return p.pR.Read(buf)
+}
+
+// closeWithError closes the wrapper and its underlying reader. It will
+// cause future calls to Read to return err.
+func (p *cancelReadCloser) closeWithError(err error) {
+	p.pW.CloseWithError(err)
+	p.cancel()
+}
+
+// Close closes the wrapper its underlying reader. It will cause
+// future calls to Read to return io.EOF.
+func (p *cancelReadCloser) Close() error {
+	p.closeWithError(io.EOF)
+	return nil
+}

vendor/github.com/docker/docker/pkg/ioutils/temp_unix.go

@@ -0,0 +1,10 @@
+// +build !windows
+
+package ioutils
+
+import "io/ioutil"
+
+// TempDir on Unix systems is equivalent to ioutil.TempDir.
+func TempDir(dir, prefix string) (string, error) {
+	return ioutil.TempDir(dir, prefix)
+}

vendor/github.com/docker/docker/pkg/ioutils/temp_windows.go

@@ -0,0 +1,18 @@
+// +build windows
+
+package ioutils
+
+import (
+	"io/ioutil"
+
+	"github.com/docker/docker/pkg/longpath"
+)
+
+// TempDir is the equivalent of ioutil.TempDir, except that the result is in Windows longpath format.
+func TempDir(dir, prefix string) (string, error) {
+	tempDir, err := ioutil.TempDir(dir, prefix)
+	if err != nil {
+		return "", err
+	}
+	return longpath.AddPrefix(tempDir), nil
+}

vendor/github.com/docker/docker/pkg/ioutils/writeflusher.go

@@ -0,0 +1,92 @@
+package ioutils
+
+import (
+	"io"
+	"sync"
+)
+
+// WriteFlusher wraps the Write and Flush operation ensuring that every write
+// is a flush. In addition, the Close method can be called to intercept
+// Read/Write calls if the targets lifecycle has already ended.
+type WriteFlusher struct {
+	w           io.Writer
+	flusher     flusher
+	flushed     chan struct{}
+	flushedOnce sync.Once
+	closed      chan struct{}
+	closeLock   sync.Mutex
+}
+
+type flusher interface {
+	Flush()
+}
+
+var errWriteFlusherClosed = io.EOF
+
+func (wf *WriteFlusher) Write(b []byte) (n int, err error) {
+	select {
+	case <-wf.closed:
+		return 0, errWriteFlusherClosed
+	default:
+	}
+
+	n, err = wf.w.Write(b)
+	wf.Flush() // every write is a flush.
+	return n, err
+}
+
+// Flush the stream immediately.
+func (wf *WriteFlusher) Flush() {
+	select {
+	case <-wf.closed:
+		return
+	default:
+	}
+
+	wf.flushedOnce.Do(func() {
+		close(wf.flushed)
+	})
+	wf.flusher.Flush()
+}
+
+// Flushed returns the state of flushed.
+// If it's flushed, return true, or else it return false.
+func (wf *WriteFlusher) Flushed() bool {
+	// BUG(stevvooe): Remove this method. Its use is inherently racy. Seems to
+	// be used to detect whether or a response code has been issued or not.
+	// Another hook should be used instead.
+	var flushed bool
+	select {
+	case <-wf.flushed:
+		flushed = true
+	default:
+	}
+	return flushed
+}
+
+// Close closes the write flusher, disallowing any further writes to the
+// target. After the flusher is closed, all calls to write or flush will
+// result in an error.
+func (wf *WriteFlusher) Close() error {
+	wf.closeLock.Lock()
+	defer wf.closeLock.Unlock()
+
+	select {
+	case <-wf.closed:
+		return errWriteFlusherClosed
+	default:
+		close(wf.closed)
+	}
+	return nil
+}
+
+// NewWriteFlusher returns a new WriteFlusher.
+func NewWriteFlusher(w io.Writer) *WriteFlusher {
+	var fl flusher
+	if f, ok := w.(flusher); ok {
+		fl = f
+	} else {
+		fl = &NopFlusher{}
+	}
+	return &WriteFlusher{w: w, flusher: fl, closed: make(chan struct{}), flushed: make(chan struct{})}
+}

vendor/github.com/docker/docker/pkg/ioutils/writers.go

@@ -0,0 +1,66 @@
+package ioutils
+
+import "io"
+
+// NopWriter represents a type which write operation is nop.
+type NopWriter struct{}
+
+func (*NopWriter) Write(buf []byte) (int, error) {
+	return len(buf), nil
+}
+
+type nopWriteCloser struct {
+	io.Writer
+}
+
+func (w *nopWriteCloser) Close() error { return nil }
+
+// NopWriteCloser returns a nopWriteCloser.
+func NopWriteCloser(w io.Writer) io.WriteCloser {
+	return &nopWriteCloser{w}
+}
+
+// NopFlusher represents a type which flush operation is nop.
+type NopFlusher struct{}
+
+// Flush is a nop operation.
+func (f *NopFlusher) Flush() {}
+
+type writeCloserWrapper struct {
+	io.Writer
+	closer func() error
+}
+
+func (r *writeCloserWrapper) Close() error {
+	return r.closer()
+}
+
+// NewWriteCloserWrapper returns a new io.WriteCloser.
+func NewWriteCloserWrapper(r io.Writer, closer func() error) io.WriteCloser {
+	return &writeCloserWrapper{
+		Writer: r,
+		closer: closer,
+	}
+}
+
+// WriteCounter wraps a concrete io.Writer and hold a count of the number
+// of bytes written to the writer during a "session".
+// This can be convenient when write return is masked
+// (e.g., json.Encoder.Encode())
+type WriteCounter struct {
+	Count  int64
+	Writer io.Writer
+}
+
+// NewWriteCounter returns a new WriteCounter.
+func NewWriteCounter(w io.Writer) *WriteCounter {
+	return &WriteCounter{
+		Writer: w,
+	}
+}
+
+func (wc *WriteCounter) Write(p []byte) (count int, err error) {
+	count, err = wc.Writer.Write(p)
+	wc.Count += int64(count)
+	return
+}

vendor/github.com/docker/docker/pkg/longpath/longpath.go

@@ -0,0 +1,26 @@
+// longpath introduces some constants and helper functions for handling long paths
+// in Windows, which are expected to be prepended with `\\?\` and followed by either
+// a drive letter, a UNC server\share, or a volume identifier.
+
+package longpath
+
+import (
+	"strings"
+)
+
+// Prefix is the longpath prefix for Windows file paths.
+const Prefix = `\\?\`
+
+// AddPrefix will add the Windows long path prefix to the path provided if
+// it does not already have it.
+func AddPrefix(path string) string {
+	if !strings.HasPrefix(path, Prefix) {
+		if strings.HasPrefix(path, `\\`) {
+			// This is a UNC path, so we need to add 'UNC' to the path as well.
+			path = Prefix + `UNC` + path[1:]
+		} else {
+			path = Prefix + path
+		}
+	}
+	return path
+}

vendor/github.com/docker/docker/pkg/pools/pools.go

@@ -0,0 +1,116 @@
+// Package pools provides a collection of pools which provide various
+// data types with buffers. These can be used to lower the number of
+// memory allocations and reuse buffers.
+//
+// New pools should be added to this package to allow them to be
+// shared across packages.
+//
+// Utility functions which operate on pools should be added to this
+// package to allow them to be reused.
+package pools
+
+import (
+	"bufio"
+	"io"
+	"sync"
+
+	"github.com/docker/docker/pkg/ioutils"
+)
+
+var (
+	// BufioReader32KPool is a pool which returns bufio.Reader with a 32K buffer.
+	BufioReader32KPool = newBufioReaderPoolWithSize(buffer32K)
+	// BufioWriter32KPool is a pool which returns bufio.Writer with a 32K buffer.
+	BufioWriter32KPool = newBufioWriterPoolWithSize(buffer32K)
+)
+
+const buffer32K = 32 * 1024
+
+// BufioReaderPool is a bufio reader that uses sync.Pool.
+type BufioReaderPool struct {
+	pool sync.Pool
+}
+
+// newBufioReaderPoolWithSize is unexported because new pools should be
+// added here to be shared where required.
+func newBufioReaderPoolWithSize(size int) *BufioReaderPool {
+	return &BufioReaderPool{
+		pool: sync.Pool{
+			New: func() interface{} { return bufio.NewReaderSize(nil, size) },
+		},
+	}
+}
+
+// Get returns a bufio.Reader which reads from r. The buffer size is that of the pool.
+func (bufPool *BufioReaderPool) Get(r io.Reader) *bufio.Reader {
+	buf := bufPool.pool.Get().(*bufio.Reader)
+	buf.Reset(r)
+	return buf
+}
+
+// Put puts the bufio.Reader back into the pool.
+func (bufPool *BufioReaderPool) Put(b *bufio.Reader) {
+	b.Reset(nil)
+	bufPool.pool.Put(b)
+}
+
+// Copy is a convenience wrapper which uses a buffer to avoid allocation in io.Copy.
+func Copy(dst io.Writer, src io.Reader) (written int64, err error) {
+	buf := BufioReader32KPool.Get(src)
+	written, err = io.Copy(dst, buf)
+	BufioReader32KPool.Put(buf)
+	return
+}
+
+// NewReadCloserWrapper returns a wrapper which puts the bufio.Reader back
+// into the pool and closes the reader if it's an io.ReadCloser.
+func (bufPool *BufioReaderPool) NewReadCloserWrapper(buf *bufio.Reader, r io.Reader) io.ReadCloser {
+	return ioutils.NewReadCloserWrapper(r, func() error {
+		if readCloser, ok := r.(io.ReadCloser); ok {
+			readCloser.Close()
+		}
+		bufPool.Put(buf)
+		return nil
+	})
+}
+
+// BufioWriterPool is a bufio writer that uses sync.Pool.
+type BufioWriterPool struct {
+	pool sync.Pool
+}
+
+// newBufioWriterPoolWithSize is unexported because new pools should be
+// added here to be shared where required.
+func newBufioWriterPoolWithSize(size int) *BufioWriterPool {
+	return &BufioWriterPool{
+		pool: sync.Pool{
+			New: func() interface{} { return bufio.NewWriterSize(nil, size) },
+		},
+	}
+}
+
+// Get returns a bufio.Writer which writes to w. The buffer size is that of the pool.
+func (bufPool *BufioWriterPool) Get(w io.Writer) *bufio.Writer {
+	buf := bufPool.pool.Get().(*bufio.Writer)
+	buf.Reset(w)
+	return buf
+}
+
+// Put puts the bufio.Writer back into the pool.
+func (bufPool *BufioWriterPool) Put(b *bufio.Writer) {
+	b.Reset(nil)
+	bufPool.pool.Put(b)
+}
+
+// NewWriteCloserWrapper returns a wrapper which puts the bufio.Writer back
+// into the pool and closes the writer if it's an io.Writecloser.
+func (bufPool *BufioWriterPool) NewWriteCloserWrapper(buf *bufio.Writer, w io.Writer) io.WriteCloser {
+	return ioutils.NewWriteCloserWrapper(w, func() error {
+		buf.Flush()
+		if writeCloser, ok := w.(io.WriteCloser); ok {
+			writeCloser.Close()
+		}
+		bufPool.Put(buf)
+		return nil
+	})
+}

vendor/github.com/docker/docker/pkg/promise/promise.go

@@ -0,0 +1,11 @@
+package promise
+
+// Go is a basic promise implementation: it wraps calls a function in a goroutine,
+// and returns a channel which will later return the function's return value.
+func Go(f func() error) chan error {
+	ch := make(chan error, 1)
+	go func() {
+		ch <- f()
+	}()
+	return ch
+}

vendor/github.com/docker/docker/pkg/system/chtimes.go

@@ -0,0 +1,52 @@
+package system
+
+import (
+	"os"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+var (
+	maxTime time.Time
+)
+
+func init() {
+	if unsafe.Sizeof(syscall.Timespec{}.Nsec) == 8 {
+		// This is a 64 bit timespec
+		// os.Chtimes limits time to the following
+		maxTime = time.Unix(0, 1<<63-1)
+	} else {
+		// This is a 32 bit timespec
+		maxTime = time.Unix(1<<31-1, 0)
+	}
+}
+
+// Chtimes changes the access time and modified time of a file at the given path
+func Chtimes(name string, atime time.Time, mtime time.Time) error {
+	unixMinTime := time.Unix(0, 0)
+	unixMaxTime := maxTime
+
+	// If the modified time is prior to the Unix Epoch, or after the
+	// end of Unix Time, os.Chtimes has undefined behavior
+	// default to Unix Epoch in this case, just in case
+
+	if atime.Before(unixMinTime) || atime.After(unixMaxTime) {
+		atime = unixMinTime
+	}
+
+	if mtime.Before(unixMinTime) || mtime.After(unixMaxTime) {
+		mtime = unixMinTime
+	}
+
+	if err := os.Chtimes(name, atime, mtime); err != nil {
+		return err
+	}
+
+	// Take platform specific action for setting create time.
+	if err := setCTime(name, mtime); err != nil {
+		return err
+	}
+
+	return nil
+}

vendor/github.com/docker/docker/pkg/system/chtimes_unix.go

@@ -0,0 +1,14 @@
+// +build !windows
+
+package system
+
+import (
+	"time"
+)
+
+//setCTime will set the create time on a file. On Unix, the create
+//time is updated as a side effect of setting the modified time, so
+//no action is required.
+func setCTime(path string, ctime time.Time) error {
+	return nil
+}

vendor/github.com/docker/docker/pkg/system/chtimes_windows.go

@@ -0,0 +1,27 @@
+// +build windows
+
+package system
+
+import (
+	"syscall"
+	"time"
+)
+
+//setCTime will set the create time on a file. On Windows, this requires
+//calling SetFileTime and explicitly including the create time.
+func setCTime(path string, ctime time.Time) error {
+	ctimespec := syscall.NsecToTimespec(ctime.UnixNano())
+	pathp, e := syscall.UTF16PtrFromString(path)
+	if e != nil {
+		return e
+	}
+	h, e := syscall.CreateFile(pathp,
+		syscall.FILE_WRITE_ATTRIBUTES, syscall.FILE_SHARE_WRITE, nil,
+		syscall.OPEN_EXISTING, syscall.FILE_FLAG_BACKUP_SEMANTICS, 0)
+	if e != nil {
+		return e
+	}
+	defer syscall.Close(h)
+	c := syscall.NsecToFiletime(syscall.TimespecToNsec(ctimespec))
+	return syscall.SetFileTime(h, &c, nil, nil)
+}

vendor/github.com/docker/docker/pkg/system/errors.go

@@ -0,0 +1,10 @@
+package system
+
+import (
+	"errors"
+)
+
+var (
+	// ErrNotSupportedPlatform means the platform is not supported.
+	ErrNotSupportedPlatform = errors.New("platform and architecture is not supported")
+)

vendor/github.com/docker/docker/pkg/system/events_windows.go

@@ -0,0 +1,85 @@
+package system
+
+// This file implements syscalls for Win32 events which are not implemented
+// in golang.
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var (
+	procCreateEvent = modkernel32.NewProc("CreateEventW")
+	procOpenEvent   = modkernel32.NewProc("OpenEventW")
+	procSetEvent    = modkernel32.NewProc("SetEvent")
+	procResetEvent  = modkernel32.NewProc("ResetEvent")
+	procPulseEvent  = modkernel32.NewProc("PulseEvent")
+)
+
+// CreateEvent implements win32 CreateEventW func in golang. It will create an event object.
+func CreateEvent(eventAttributes *syscall.SecurityAttributes, manualReset bool, initialState bool, name string) (handle syscall.Handle, err error) {
+	namep, _ := syscall.UTF16PtrFromString(name)
+	var _p1 uint32
+	if manualReset {
+		_p1 = 1
+	}
+	var _p2 uint32
+	if initialState {
+		_p2 = 1
+	}
+	r0, _, e1 := procCreateEvent.Call(uintptr(unsafe.Pointer(eventAttributes)), uintptr(_p1), uintptr(_p2), uintptr(unsafe.Pointer(namep)))
+	use(unsafe.Pointer(namep))
+	handle = syscall.Handle(r0)
+	if handle == syscall.InvalidHandle {
+		err = e1
+	}
+	return
+}
+
+// OpenEvent implements win32 OpenEventW func in golang. It opens an event object.
+func OpenEvent(desiredAccess uint32, inheritHandle bool, name string) (handle syscall.Handle, err error) {
+	namep, _ := syscall.UTF16PtrFromString(name)
+	var _p1 uint32
+	if inheritHandle {
+		_p1 = 1
+	}
+	r0, _, e1 := procOpenEvent.Call(uintptr(desiredAccess), uintptr(_p1), uintptr(unsafe.Pointer(namep)))
+	use(unsafe.Pointer(namep))
+	handle = syscall.Handle(r0)
+	if handle == syscall.InvalidHandle {
+		err = e1
+	}
+	return
+}
+
+// SetEvent implements win32 SetEvent func in golang.
+func SetEvent(handle syscall.Handle) (err error) {
+	return setResetPulse(handle, procSetEvent)
+}
+
+// ResetEvent implements win32 ResetEvent func in golang.
+func ResetEvent(handle syscall.Handle) (err error) {
+	return setResetPulse(handle, procResetEvent)
+}
+
+// PulseEvent implements win32 PulseEvent func in golang.
+func PulseEvent(handle syscall.Handle) (err error) {
+	return setResetPulse(handle, procPulseEvent)
+}
+
+func setResetPulse(handle syscall.Handle, proc *windows.LazyProc) (err error) {
+	r0, _, _ := proc.Call(uintptr(handle))
+	if r0 != 0 {
+		err = syscall.Errno(r0)
+	}
+	return
+}
+
+var temp unsafe.Pointer
+
+// use ensures a variable is kept alive without the GC freeing while still needed
+func use(p unsafe.Pointer) {
+	temp = p
+}

vendor/github.com/docker/docker/pkg/system/exitcode.go

@@ -0,0 +1,33 @@
+package system
+
+import (
+	"fmt"
+	"os/exec"
+	"syscall"
+)
+
+// GetExitCode returns the ExitStatus of the specified error if its type is
+// exec.ExitError, returns 0 and an error otherwise.
+func GetExitCode(err error) (int, error) {
+	exitCode := 0
+	if exiterr, ok := err.(*exec.ExitError); ok {
+		if procExit, ok := exiterr.Sys().(syscall.WaitStatus); ok {
+			return procExit.ExitStatus(), nil
+		}
+	}
+	return exitCode, fmt.Errorf("failed to get exit code")
+}
+
+// ProcessExitCode process the specified error and returns the exit status code
+// if the error was of type exec.ExitError, returns nothing otherwise.
+func ProcessExitCode(err error) (exitCode int) {
+	if err != nil {
+		var exiterr error
+		if exitCode, exiterr = GetExitCode(err); exiterr != nil {
+			// TODO: Fix this so we check the error's text.
+			// we've failed to retrieve exit code, so we set it to 127
+			exitCode = 127
+		}
+	}
+	return
+}

vendor/github.com/docker/docker/pkg/system/filesys.go

@@ -0,0 +1,54 @@
+// +build !windows
+
+package system
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// MkdirAllWithACL is a wrapper for MkdirAll that creates a directory
+// ACL'd for Builtin Administrators and Local System.
+func MkdirAllWithACL(path string, perm os.FileMode) error {
+	return MkdirAll(path, perm)
+}
+
+// MkdirAll creates a directory named path along with any necessary parents,
+// with permission specified by attribute perm for all dir created.
+func MkdirAll(path string, perm os.FileMode) error {
+	return os.MkdirAll(path, perm)
+}
+
+// IsAbs is a platform-specific wrapper for filepath.IsAbs.
+func IsAbs(path string) bool {
+	return filepath.IsAbs(path)
+}
+
+// The functions below here are wrappers for the equivalents in the os package.
+// They are passthrough on Unix platforms, and only relevant on Windows.
+
+// CreateSequential creates the named file with mode 0666 (before umask), truncating
+// it if it already exists. If successful, methods on the returned
+// File can be used for I/O; the associated file descriptor has mode
+// O_RDWR.
+// If there is an error, it will be of type *PathError.
+func CreateSequential(name string) (*os.File, error) {
+	return os.Create(name)
+}
+
+// OpenSequential opens the named file for reading. If successful, methods on
+// the returned file can be used for reading; the associated file
+// descriptor has mode O_RDONLY.
+// If there is an error, it will be of type *PathError.
+func OpenSequential(name string) (*os.File, error) {
+	return os.Open(name)
+}
+
+// OpenFileSequential is the generalized open call; most users will use Open
+// or Create instead. It opens the named file with specified flag
+// (O_RDONLY etc.) and perm, (0666 etc.) if applicable. If successful,
+// methods on the returned File can be used for I/O.
+// If there is an error, it will be of type *PathError.
+func OpenFileSequential(name string, flag int, perm os.FileMode) (*os.File, error) {
+	return os.OpenFile(name, flag, perm)
+}

vendor/github.com/docker/docker/pkg/system/filesys_windows.go

@@ -0,0 +1,236 @@
+// +build windows
+
+package system
+
+import (
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"syscall"
+	"unsafe"
+
+	winio "github.com/Microsoft/go-winio"
+)
+
+// MkdirAllWithACL is a wrapper for MkdirAll that creates a directory
+// ACL'd for Builtin Administrators and Local System.
+func MkdirAllWithACL(path string, perm os.FileMode) error {
+	return mkdirall(path, true)
+}
+
+// MkdirAll implementation that is volume path aware for Windows.
+func MkdirAll(path string, _ os.FileMode) error {
+	return mkdirall(path, false)
+}
+
+// mkdirall is a custom version of os.MkdirAll modified for use on Windows
+// so that it is both volume path aware, and can create a directory with
+// a DACL.
+func mkdirall(path string, adminAndLocalSystem bool) error {
+	if re := regexp.MustCompile(`^\\\\\?\\Volume{[a-z0-9-]+}$`); re.MatchString(path) {
+		return nil
+	}
+
+	// The rest of this method is largely copied from os.MkdirAll and should be kept
+	// as-is to ensure compatibility.
+
+	// Fast path: if we can tell whether path is a directory or file, stop with success or error.
+	dir, err := os.Stat(path)
+	if err == nil {
+		if dir.IsDir() {
+			return nil
+		}
+		return &os.PathError{
+			Op:   "mkdir",
+			Path: path,
+			Err:  syscall.ENOTDIR,
+		}
+	}
+
+	// Slow path: make sure parent exists and then call Mkdir for path.
+	i := len(path)
+	for i > 0 && os.IsPathSeparator(path[i-1]) { // Skip trailing path separator.
+		i--
+	}
+
+	j := i
+	for j > 0 && !os.IsPathSeparator(path[j-1]) { // Scan backward over element.
+		j--
+	}
+
+	if j > 1 {
+		// Create parent
+		err = mkdirall(path[0:j-1], false)
+		if err != nil {
+			return err
+		}
+	}
+
+	// Parent now exists; invoke os.Mkdir or mkdirWithACL and use its result.
+	if adminAndLocalSystem {
+		err = mkdirWithACL(path)
+	} else {
+		err = os.Mkdir(path, 0)
+	}
+
+	if err != nil {
+		// Handle arguments like "foo/." by
+		// double-checking that directory doesn't exist.
+		dir, err1 := os.Lstat(path)
+		if err1 == nil && dir.IsDir() {
+			return nil
+		}
+		return err
+	}
+	return nil
+}
+
+// mkdirWithACL creates a new directory. If there is an error, it will be of
+// type *PathError. .
+//
+// This is a modified and combined version of os.Mkdir and syscall.Mkdir
+// in golang to cater for creating a directory am ACL permitting full
+// access, with inheritance, to any subfolder/file for Built-in Administrators
+// and Local System.
+func mkdirWithACL(name string) error {
+	sa := syscall.SecurityAttributes{Length: 0}
+	sddl := "D:P(A;OICI;GA;;;BA)(A;OICI;GA;;;SY)"
+	sd, err := winio.SddlToSecurityDescriptor(sddl)
+	if err != nil {
+		return &os.PathError{Op: "mkdir", Path: name, Err: err}
+	}
+	sa.Length = uint32(unsafe.Sizeof(sa))
+	sa.InheritHandle = 1
+	sa.SecurityDescriptor = uintptr(unsafe.Pointer(&sd[0]))
+
+	namep, err := syscall.UTF16PtrFromString(name)
+	if err != nil {
+		return &os.PathError{Op: "mkdir", Path: name, Err: err}
+	}
+
+	e := syscall.CreateDirectory(namep, &sa)
+	if e != nil {
+		return &os.PathError{Op: "mkdir", Path: name, Err: e}
+	}
+	return nil
+}
+
+// IsAbs is a platform-specific wrapper for filepath.IsAbs. On Windows,
+// golang filepath.IsAbs does not consider a path \windows\system32 as absolute
+// as it doesn't start with a drive-letter/colon combination. However, in
+// docker we need to verify things such as WORKDIR /windows/system32 in
+// a Dockerfile (which gets translated to \windows\system32 when being processed
+// by the daemon. This SHOULD be treated as absolute from a docker processing
+// perspective.
+func IsAbs(path string) bool {
+	if !filepath.IsAbs(path) {
+		if !strings.HasPrefix(path, string(os.PathSeparator)) {
+			return false
+		}
+	}
+	return true
+}
+
+// The origin of the functions below here are the golang OS and syscall packages,
+// slightly modified to only cope with files, not directories due to the
+// specific use case.
+//
+// The alteration is to allow a file on Windows to be opened with
+// FILE_FLAG_SEQUENTIAL_SCAN (particular for docker load), to avoid eating
+// the standby list, particularly when accessing large files such as layer.tar.
+
+// CreateSequential creates the named file with mode 0666 (before umask), truncating
+// it if it already exists. If successful, methods on the returned
+// File can be used for I/O; the associated file descriptor has mode
+// O_RDWR.
+// If there is an error, it will be of type *PathError.
+func CreateSequential(name string) (*os.File, error) {
+	return OpenFileSequential(name, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0)
+}
+
+// OpenSequential opens the named file for reading. If successful, methods on
+// the returned file can be used for reading; the associated file
+// descriptor has mode O_RDONLY.
+// If there is an error, it will be of type *PathError.
+func OpenSequential(name string) (*os.File, error) {
+	return OpenFileSequential(name, os.O_RDONLY, 0)
+}
+
+// OpenFileSequential is the generalized open call; most users will use Open
+// or Create instead.
+// If there is an error, it will be of type *PathError.
+func OpenFileSequential(name string, flag int, _ os.FileMode) (*os.File, error) {
+	if name == "" {
+		return nil, &os.PathError{Op: "open", Path: name, Err: syscall.ENOENT}
+	}
+	r, errf := syscallOpenFileSequential(name, flag, 0)
+	if errf == nil {
+		return r, nil
+	}
+	return nil, &os.PathError{Op: "open", Path: name, Err: errf}
+}
+
+func syscallOpenFileSequential(name string, flag int, _ os.FileMode) (file *os.File, err error) {
+	r, e := syscallOpenSequential(name, flag|syscall.O_CLOEXEC, 0)
+	if e != nil {
+		return nil, e
+	}
+	return os.NewFile(uintptr(r), name), nil
+}
+
+func makeInheritSa() *syscall.SecurityAttributes {
+	var sa syscall.SecurityAttributes
+	sa.Length = uint32(unsafe.Sizeof(sa))
+	sa.InheritHandle = 1
+	return &sa
+}
+
+func syscallOpenSequential(path string, mode int, _ uint32) (fd syscall.Handle, err error) {
+	if len(path) == 0 {
+		return syscall.InvalidHandle, syscall.ERROR_FILE_NOT_FOUND
+	}
+	pathp, err := syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return syscall.InvalidHandle, err
+	}
+	var access uint32
+	switch mode & (syscall.O_RDONLY | syscall.O_WRONLY | syscall.O_RDWR) {
+	case syscall.O_RDONLY:
+		access = syscall.GENERIC_READ
+	case syscall.O_WRONLY:
+		access = syscall.GENERIC_WRITE
+	case syscall.O_RDWR:
+		access = syscall.GENERIC_READ | syscall.GENERIC_WRITE
+	}
+	if mode&syscall.O_CREAT != 0 {
+		access |= syscall.GENERIC_WRITE
+	}
+	if mode&syscall.O_APPEND != 0 {
+		access &^= syscall.GENERIC_WRITE
+		access |= syscall.FILE_APPEND_DATA
+	}
+	sharemode := uint32(syscall.FILE_SHARE_READ | syscall.FILE_SHARE_WRITE)
+	var sa *syscall.SecurityAttributes
+	if mode&syscall.O_CLOEXEC == 0 {
+		sa = makeInheritSa()
+	}
+	var createmode uint32
+	switch {
+	case mode&(syscall.O_CREAT|syscall.O_EXCL) == (syscall.O_CREAT | syscall.O_EXCL):
+		createmode = syscall.CREATE_NEW
+	case mode&(syscall.O_CREAT|syscall.O_TRUNC) == (syscall.O_CREAT | syscall.O_TRUNC):
+		createmode = syscall.CREATE_ALWAYS
+	case mode&syscall.O_CREAT == syscall.O_CREAT:
+		createmode = syscall.OPEN_ALWAYS
+	case mode&syscall.O_TRUNC == syscall.O_TRUNC:
+		createmode = syscall.TRUNCATE_EXISTING
+	default:
+		createmode = syscall.OPEN_EXISTING
+	}
+	// Use FILE_FLAG_SEQUENTIAL_SCAN rather than FILE_ATTRIBUTE_NORMAL as implemented in golang.
+	//https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858(v=vs.85).aspx
+	const fileFlagSequentialScan = 0x08000000 // FILE_FLAG_SEQUENTIAL_SCAN
+	h, e := syscall.CreateFile(pathp, access, sharemode, sa, createmode, fileFlagSequentialScan, 0)
+	return h, e
+}

vendor/github.com/docker/docker/pkg/system/lstat.go

@@ -0,0 +1,19 @@
+// +build !windows
+
+package system
+
+import (
+	"syscall"
+)
+
+// Lstat takes a path to a file and returns
+// a system.StatT type pertaining to that file.
+//
+// Throws an error if the file does not exist
+func Lstat(path string) (*StatT, error) {
+	s := &syscall.Stat_t{}
+	if err := syscall.Lstat(path, s); err != nil {
+		return nil, err
+	}
+	return fromStatT(s)
+}

vendor/github.com/docker/docker/pkg/system/lstat_windows.go

@@ -0,0 +1,25 @@
+// +build windows
+
+package system
+
+import (
+	"os"
+)
+
+// Lstat calls os.Lstat to get a fileinfo interface back.
+// This is then copied into our own locally defined structure.
+// Note the Linux version uses fromStatT to do the copy back,
+// but that not strictly necessary when already in an OS specific module.
+func Lstat(path string) (*StatT, error) {
+	fi, err := os.Lstat(path)
+	if err != nil {
+		return nil, err
+	}
+
+	return &StatT{
+		name:    fi.Name(),
+		size:    fi.Size(),
+		mode:    fi.Mode(),
+		modTime: fi.ModTime(),
+		isDir:   fi.IsDir()}, nil
+}

vendor/github.com/docker/docker/pkg/system/meminfo.go

@@ -0,0 +1,17 @@
+package system
+
+// MemInfo contains memory statistics of the host system.
+type MemInfo struct {
+	// Total usable RAM (i.e. physical RAM minus a few reserved bits and the
+	// kernel binary code).
+	MemTotal int64
+
+	// Amount of free memory.
+	MemFree int64
+
+	// Total amount of swap space available.
+	SwapTotal int64
+
+	// Amount of swap space that is currently unused.
+	SwapFree int64
+}

vendor/github.com/docker/docker/pkg/system/meminfo_linux.go

@@ -0,0 +1,65 @@
+package system
+
+import (
+	"bufio"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/docker/go-units"
+)
+
+// ReadMemInfo retrieves memory statistics of the host system and returns a
+// MemInfo type.
+func ReadMemInfo() (*MemInfo, error) {
+	file, err := os.Open("/proc/meminfo")
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	return parseMemInfo(file)
+}
+
+// parseMemInfo parses the /proc/meminfo file into
+// a MemInfo object given an io.Reader to the file.
+// Throws error if there are problems reading from the file
+func parseMemInfo(reader io.Reader) (*MemInfo, error) {
+	meminfo := &MemInfo{}
+	scanner := bufio.NewScanner(reader)
+	for scanner.Scan() {
+		// Expected format: ["MemTotal:", "1234", "kB"]
+		parts := strings.Fields(scanner.Text())
+
+		// Sanity checks: Skip malformed entries.
+		if len(parts) < 3 || parts[2] != "kB" {
+			continue
+		}
+
+		// Convert to bytes.
+		size, err := strconv.Atoi(parts[1])
+		if err != nil {
+			continue
+		}
+		bytes := int64(size) * units.KiB
+
+		switch parts[0] {
+		case "MemTotal:":
+			meminfo.MemTotal = bytes
+		case "MemFree:":
+			meminfo.MemFree = bytes
+		case "SwapTotal:":
+			meminfo.SwapTotal = bytes
+		case "SwapFree:":
+			meminfo.SwapFree = bytes
+		}
+
+	}
+
+	// Handle errors that may have occurred during the reading of the file.
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return meminfo, nil
+}

vendor/github.com/docker/docker/pkg/system/meminfo_solaris.go

@@ -0,0 +1,128 @@
+// +build solaris,cgo
+
+package system
+
+import (
+	"fmt"
+	"unsafe"
+)
+
+// #cgo LDFLAGS: -lkstat
+// #include <unistd.h>
+// #include <stdlib.h>
+// #include <stdio.h>
+// #include <kstat.h>
+// #include <sys/swap.h>
+// #include <sys/param.h>
+// struct swaptable *allocSwaptable(int num) {
+//	struct swaptable *st;
+//	struct swapent *swapent;
+// 	st = (struct swaptable *)malloc(num * sizeof(swapent_t) + sizeof (int));
+//	swapent = st->swt_ent;
+//	for (int i = 0; i < num; i++,swapent++) {
+//		swapent->ste_path = (char *)malloc(MAXPATHLEN * sizeof (char));
+//	}
+//	st->swt_n = num;
+//	return st;
+//}
+// void freeSwaptable (struct swaptable *st) {
+//	struct swapent *swapent = st->swt_ent;
+//	for (int i = 0; i < st->swt_n; i++,swapent++) {
+//		free(swapent->ste_path);
+//	}
+//	free(st);
+// }
+// swapent_t getSwapEnt(swapent_t *ent, int i) {
+//	return ent[i];
+// }
+// int64_t getPpKernel() {
+//	int64_t pp_kernel = 0;
+//	kstat_ctl_t *ksc;
+//	kstat_t *ks;
+//	kstat_named_t *knp;
+//	kid_t kid;
+//
+//	if ((ksc = kstat_open()) == NULL) {
+//		return -1;
+//	}
+//	if ((ks = kstat_lookup(ksc, "unix", 0, "system_pages")) == NULL) {
+//		return -1;
+//	}
+//	if (((kid = kstat_read(ksc, ks, NULL)) == -1) ||
+//	    ((knp = kstat_data_lookup(ks, "pp_kernel")) == NULL)) {
+//		return -1;
+//	}
+//	switch (knp->data_type) {
+//	case KSTAT_DATA_UINT64:
+//		pp_kernel = knp->value.ui64;
+//		break;
+//	case KSTAT_DATA_UINT32:
+//		pp_kernel = knp->value.ui32;
+//		break;
+//	}
+//	pp_kernel *= sysconf(_SC_PAGESIZE);
+//	return (pp_kernel > 0 ? pp_kernel : -1);
+// }
+import "C"
+
+// Get the system memory info using sysconf same as prtconf
+func getTotalMem() int64 {
+	pagesize := C.sysconf(C._SC_PAGESIZE)
+	npages := C.sysconf(C._SC_PHYS_PAGES)
+	return int64(pagesize * npages)
+}
+
+func getFreeMem() int64 {
+	pagesize := C.sysconf(C._SC_PAGESIZE)
+	npages := C.sysconf(C._SC_AVPHYS_PAGES)
+	return int64(pagesize * npages)
+}
+
+// ReadMemInfo retrieves memory statistics of the host system and returns a
+//  MemInfo type.
+func ReadMemInfo() (*MemInfo, error) {
+
+	ppKernel := C.getPpKernel()
+	MemTotal := getTotalMem()
+	MemFree := getFreeMem()
+	SwapTotal, SwapFree, err := getSysSwap()
+
+	if ppKernel < 0 || MemTotal < 0 || MemFree < 0 || SwapTotal < 0 ||
+		SwapFree < 0 {
+		return nil, fmt.Errorf("error getting system memory info %v\n", err)
+	}
+
+	meminfo := &MemInfo{}
+	// Total memory is total physical memory less than memory locked by kernel
+	meminfo.MemTotal = MemTotal - int64(ppKernel)
+	meminfo.MemFree = MemFree
+	meminfo.SwapTotal = SwapTotal
+	meminfo.SwapFree = SwapFree
+
+	return meminfo, nil
+}
+
+func getSysSwap() (int64, int64, error) {
+	var tSwap int64
+	var fSwap int64
+	var diskblksPerPage int64
+	num, err := C.swapctl(C.SC_GETNSWP, nil)
+	if err != nil {
+		return -1, -1, err
+	}
+	st := C.allocSwaptable(num)
+	_, err = C.swapctl(C.SC_LIST, unsafe.Pointer(st))
+	if err != nil {
+		C.freeSwaptable(st)
+		return -1, -1, err
+	}
+
+	diskblksPerPage = int64(C.sysconf(C._SC_PAGESIZE) >> C.DEV_BSHIFT)
+	for i := 0; i < int(num); i++ {
+		swapent := C.getSwapEnt(&st.swt_ent[0], C.int(i))
+		tSwap += int64(swapent.ste_pages) * diskblksPerPage
+		fSwap += int64(swapent.ste_free) * diskblksPerPage
+	}
+	C.freeSwaptable(st)
+	return tSwap, fSwap, nil
+}

vendor/github.com/docker/docker/pkg/system/meminfo_unsupported.go

@@ -0,0 +1,8 @@
+// +build !linux,!windows,!solaris
+
+package system
+
+// ReadMemInfo is not supported on platforms other than linux and windows.
+func ReadMemInfo() (*MemInfo, error) {
+	return nil, ErrNotSupportedPlatform
+}

vendor/github.com/docker/docker/pkg/system/meminfo_windows.go

@@ -0,0 +1,45 @@
+package system
+
+import (
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var (
+	modkernel32 = windows.NewLazySystemDLL("kernel32.dll")
+
+	procGlobalMemoryStatusEx = modkernel32.NewProc("GlobalMemoryStatusEx")
+)
+
+// https://msdn.microsoft.com/en-us/library/windows/desktop/aa366589(v=vs.85).aspx
+// https://msdn.microsoft.com/en-us/library/windows/desktop/aa366770(v=vs.85).aspx
+type memorystatusex struct {
+	dwLength                uint32
+	dwMemoryLoad            uint32
+	ullTotalPhys            uint64
+	ullAvailPhys            uint64
+	ullTotalPageFile        uint64
+	ullAvailPageFile        uint64
+	ullTotalVirtual         uint64
+	ullAvailVirtual         uint64
+	ullAvailExtendedVirtual uint64
+}
+
+// ReadMemInfo retrieves memory statistics of the host system and returns a
+//  MemInfo type.
+func ReadMemInfo() (*MemInfo, error) {
+	msi := &memorystatusex{
+		dwLength: 64,
+	}
+	r1, _, _ := procGlobalMemoryStatusEx.Call(uintptr(unsafe.Pointer(msi)))
+	if r1 == 0 {
+		return &MemInfo{}, nil
+	}
+	return &MemInfo{
+		MemTotal:  int64(msi.ullTotalPhys),
+		MemFree:   int64(msi.ullAvailPhys),
+		SwapTotal: int64(msi.ullTotalPageFile),
+		SwapFree:  int64(msi.ullAvailPageFile),
+	}, nil
+}

vendor/github.com/docker/docker/pkg/system/mknod.go

@@ -0,0 +1,22 @@
+// +build !windows
+
+package system
+
+import (
+	"syscall"
+)
+
+// Mknod creates a filesystem node (file, device special file or named pipe) named path
+// with attributes specified by mode and dev.
+func Mknod(path string, mode uint32, dev int) error {
+	return syscall.Mknod(path, mode, dev)
+}
+
+// Mkdev is used to build the value of linux devices (in /dev/) which specifies major
+// and minor number of the newly created device special file.
+// Linux device nodes are a bit weird due to backwards compat with 16 bit device nodes.
+// They are, from low to high: the lower 8 bits of the minor, then 12 bits of the major,
+// then the top 12 bits of the minor.
+func Mkdev(major int64, minor int64) uint32 {
+	return uint32(((minor & 0xfff00) << 12) | ((major & 0xfff) << 8) | (minor & 0xff))
+}

vendor/github.com/docker/docker/pkg/system/mknod_windows.go

@@ -0,0 +1,13 @@
+// +build windows
+
+package system
+
+// Mknod is not implemented on Windows.
+func Mknod(path string, mode uint32, dev int) error {
+	return ErrNotSupportedPlatform
+}
+
+// Mkdev is not implemented on Windows.
+func Mkdev(major int64, minor int64) uint32 {
+	panic("Mkdev not implemented on Windows.")
+}

vendor/github.com/docker/docker/pkg/system/path_unix.go

@@ -0,0 +1,14 @@
+// +build !windows
+
+package system
+
+// DefaultPathEnv is unix style list of directories to search for
+// executables. Each directory is separated from the next by a colon
+// ':' character .
+const DefaultPathEnv = "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+
+// CheckSystemDriveAndRemoveDriveLetter verifies that a path, if it includes a drive letter,
+// is the system drive. This is a no-op on Linux.
+func CheckSystemDriveAndRemoveDriveLetter(path string) (string, error) {
+	return path, nil
+}

vendor/github.com/docker/docker/pkg/system/path_windows.go

@@ -0,0 +1,37 @@
+// +build windows
+
+package system
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+)
+
+// DefaultPathEnv is deliberately empty on Windows as the default path will be set by
+// the container. Docker has no context of what the default path should be.
+const DefaultPathEnv = ""
+
+// CheckSystemDriveAndRemoveDriveLetter verifies and manipulates a Windows path.
+// This is used, for example, when validating a user provided path in docker cp.
+// If a drive letter is supplied, it must be the system drive. The drive letter
+// is always removed. Also, it translates it to OS semantics (IOW / to \). We
+// need the path in this syntax so that it can ultimately be contatenated with
+// a Windows long-path which doesn't support drive-letters. Examples:
+// C:			--> Fail
+// C:\			--> \
+// a			--> a
+// /a			--> \a
+// d:\			--> Fail
+func CheckSystemDriveAndRemoveDriveLetter(path string) (string, error) {
+	if len(path) == 2 && string(path[1]) == ":" {
+		return "", fmt.Errorf("No relative path specified in %q", path)
+	}
+	if !filepath.IsAbs(path) || len(path) < 2 {
+		return filepath.FromSlash(path), nil
+	}
+	if string(path[1]) == ":" && !strings.EqualFold(string(path[0]), "c") {
+		return "", fmt.Errorf("The specified path is not on the system drive (C:)")
+	}
+	return filepath.FromSlash(path[2:]), nil
+}

vendor/github.com/docker/docker/pkg/system/stat.go

@@ -0,0 +1,53 @@
+// +build !windows
+
+package system
+
+import (
+	"syscall"
+)
+
+// StatT type contains status of a file. It contains metadata
+// like permission, owner, group, size, etc about a file.
+type StatT struct {
+	mode uint32
+	uid  uint32
+	gid  uint32
+	rdev uint64
+	size int64
+	mtim syscall.Timespec
+}
+
+// Mode returns file's permission mode.
+func (s StatT) Mode() uint32 {
+	return s.mode
+}
+
+// UID returns file's user id of owner.
+func (s StatT) UID() uint32 {
+	return s.uid
+}
+
+// GID returns file's group id of owner.
+func (s StatT) GID() uint32 {
+	return s.gid
+}
+
+// Rdev returns file's device ID (if it's special file).
+func (s StatT) Rdev() uint64 {
+	return s.rdev
+}
+
+// Size returns file's size.
+func (s StatT) Size() int64 {
+	return s.size
+}
+
+// Mtim returns file's last modification time.
+func (s StatT) Mtim() syscall.Timespec {
+	return s.mtim
+}
+
+// GetLastModification returns file's last modification time.
+func (s StatT) GetLastModification() syscall.Timespec {
+	return s.Mtim()
+}

vendor/github.com/docker/docker/pkg/system/stat_darwin.go

@@ -0,0 +1,32 @@
+package system
+
+import (
+	"syscall"
+)
+
+// fromStatT creates a system.StatT type from a syscall.Stat_t type
+func fromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return &StatT{size: s.Size,
+		mode: uint32(s.Mode),
+		uid:  s.Uid,
+		gid:  s.Gid,
+		rdev: uint64(s.Rdev),
+		mtim: s.Mtimespec}, nil
+}
+
+// FromStatT loads a system.StatT from a syscall.Stat_t.
+func FromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return fromStatT(s)
+}
+
+// Stat takes a path to a file and returns
+// a system.StatT type pertaining to that file.
+//
+// Throws an error if the file does not exist
+func Stat(path string) (*StatT, error) {
+	s := &syscall.Stat_t{}
+	if err := syscall.Stat(path, s); err != nil {
+		return nil, err
+	}
+	return fromStatT(s)
+}

vendor/github.com/docker/docker/pkg/system/stat_freebsd.go

@@ -0,0 +1,27 @@
+package system
+
+import (
+	"syscall"
+)
+
+// fromStatT converts a syscall.Stat_t type to a system.Stat_t type
+func fromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return &StatT{size: s.Size,
+		mode: uint32(s.Mode),
+		uid:  s.Uid,
+		gid:  s.Gid,
+		rdev: uint64(s.Rdev),
+		mtim: s.Mtimespec}, nil
+}
+
+// Stat takes a path to a file and returns
+// a system.Stat_t type pertaining to that file.
+//
+// Throws an error if the file does not exist
+func Stat(path string) (*StatT, error) {
+	s := &syscall.Stat_t{}
+	if err := syscall.Stat(path, s); err != nil {
+		return nil, err
+	}
+	return fromStatT(s)
+}

vendor/github.com/docker/docker/pkg/system/stat_linux.go

@@ -0,0 +1,33 @@
+package system
+
+import (
+	"syscall"
+)
+
+// fromStatT converts a syscall.Stat_t type to a system.Stat_t type
+func fromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return &StatT{size: s.Size,
+		mode: s.Mode,
+		uid:  s.Uid,
+		gid:  s.Gid,
+		rdev: s.Rdev,
+		mtim: s.Mtim}, nil
+}
+
+// FromStatT exists only on linux, and loads a system.StatT from a
+// syscal.Stat_t.
+func FromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return fromStatT(s)
+}
+
+// Stat takes a path to a file and returns
+// a system.StatT type pertaining to that file.
+//
+// Throws an error if the file does not exist
+func Stat(path string) (*StatT, error) {
+	s := &syscall.Stat_t{}
+	if err := syscall.Stat(path, s); err != nil {
+		return nil, err
+	}
+	return fromStatT(s)
+}

vendor/github.com/docker/docker/pkg/system/stat_openbsd.go

@@ -0,0 +1,15 @@
+package system
+
+import (
+	"syscall"
+)
+
+// fromStatT creates a system.StatT type from a syscall.Stat_t type
+func fromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return &StatT{size: s.Size,
+		mode: uint32(s.Mode),
+		uid:  s.Uid,
+		gid:  s.Gid,
+		rdev: uint64(s.Rdev),
+		mtim: s.Mtim}, nil
+}

vendor/github.com/docker/docker/pkg/system/stat_solaris.go

@@ -0,0 +1,34 @@
+// +build solaris
+
+package system
+
+import (
+	"syscall"
+)
+
+// fromStatT creates a system.StatT type from a syscall.Stat_t type
+func fromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return &StatT{size: s.Size,
+		mode: uint32(s.Mode),
+		uid:  s.Uid,
+		gid:  s.Gid,
+		rdev: uint64(s.Rdev),
+		mtim: s.Mtim}, nil
+}
+
+// FromStatT loads a system.StatT from a syscal.Stat_t.
+func FromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return fromStatT(s)
+}
+
+// Stat takes a path to a file and returns
+// a system.StatT type pertaining to that file.
+//
+// Throws an error if the file does not exist
+func Stat(path string) (*StatT, error) {
+	s := &syscall.Stat_t{}
+	if err := syscall.Stat(path, s); err != nil {
+		return nil, err
+	}
+	return fromStatT(s)
+}

vendor/github.com/docker/docker/pkg/system/stat_unsupported.go

@@ -0,0 +1,17 @@
+// +build !linux,!windows,!freebsd,!solaris,!openbsd,!darwin
+
+package system
+
+import (
+	"syscall"
+)
+
+// fromStatT creates a system.StatT type from a syscall.Stat_t type
+func fromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return &StatT{size: s.Size,
+		mode: uint32(s.Mode),
+		uid:  s.Uid,
+		gid:  s.Gid,
+		rdev: uint64(s.Rdev),
+		mtim: s.Mtimespec}, nil
+}

vendor/github.com/docker/docker/pkg/system/stat_windows.go

@@ -0,0 +1,43 @@
+// +build windows
+
+package system
+
+import (
+	"os"
+	"time"
+)
+
+// StatT type contains status of a file. It contains metadata
+// like name, permission, size, etc about a file.
+type StatT struct {
+	name    string
+	size    int64
+	mode    os.FileMode
+	modTime time.Time
+	isDir   bool
+}
+
+// Name returns file's name.
+func (s StatT) Name() string {
+	return s.name
+}
+
+// Size returns file's size.
+func (s StatT) Size() int64 {
+	return s.size
+}
+
+// Mode returns file's permission mode.
+func (s StatT) Mode() os.FileMode {
+	return s.mode
+}
+
+// ModTime returns file's last modification time.
+func (s StatT) ModTime() time.Time {
+	return s.modTime
+}
+
+// IsDir returns whether file is actually a directory.
+func (s StatT) IsDir() bool {
+	return s.isDir
+}

vendor/github.com/docker/docker/pkg/system/syscall_unix.go

@@ -0,0 +1,17 @@
+// +build linux freebsd
+
+package system
+
+import "syscall"
+
+// Unmount is a platform-specific helper function to call
+// the unmount syscall.
+func Unmount(dest string) error {
+	return syscall.Unmount(dest, 0)
+}
+
+// CommandLineToArgv should not be used on Unix.
+// It simply returns commandLine in the only element in the returned array.
+func CommandLineToArgv(commandLine string) ([]string, error) {
+	return []string{commandLine}, nil
+}

vendor/github.com/docker/docker/pkg/system/syscall_windows.go

@@ -0,0 +1,105 @@
+package system
+
+import (
+	"syscall"
+	"unsafe"
+
+	"github.com/Sirupsen/logrus"
+)
+
+var (
+	ntuserApiset      = syscall.NewLazyDLL("ext-ms-win-ntuser-window-l1-1-0")
+	procGetVersionExW = modkernel32.NewProc("GetVersionExW")
+)
+
+// OSVersion is a wrapper for Windows version information
+// https://msdn.microsoft.com/en-us/library/windows/desktop/ms724439(v=vs.85).aspx
+type OSVersion struct {
+	Version      uint32
+	MajorVersion uint8
+	MinorVersion uint8
+	Build        uint16
+}
+
+// https://msdn.microsoft.com/en-us/library/windows/desktop/ms724833(v=vs.85).aspx
+type osVersionInfoEx struct {
+	OSVersionInfoSize uint32
+	MajorVersion      uint32
+	MinorVersion      uint32
+	BuildNumber       uint32
+	PlatformID        uint32
+	CSDVersion        [128]uint16
+	ServicePackMajor  uint16
+	ServicePackMinor  uint16
+	SuiteMask         uint16
+	ProductType       byte
+	Reserve           byte
+}
+
+// GetOSVersion gets the operating system version on Windows. Note that
+// docker.exe must be manifested to get the correct version information.
+func GetOSVersion() OSVersion {
+	var err error
+	osv := OSVersion{}
+	osv.Version, err = syscall.GetVersion()
+	if err != nil {
+		// GetVersion never fails.
+		panic(err)
+	}
+	osv.MajorVersion = uint8(osv.Version & 0xFF)
+	osv.MinorVersion = uint8(osv.Version >> 8 & 0xFF)
+	osv.Build = uint16(osv.Version >> 16)
+	return osv
+}
+
+// IsWindowsClient returns true if the SKU is client
+// @engine maintainers - this function should not be removed or modified as it
+// is used to enforce licensing restrictions on Windows.
+func IsWindowsClient() bool {
+	osviex := &osVersionInfoEx{OSVersionInfoSize: 284}
+	r1, _, err := procGetVersionExW.Call(uintptr(unsafe.Pointer(osviex)))
+	if r1 == 0 {
+		logrus.Warnf("GetVersionExW failed - assuming server SKU: %v", err)
+		return false
+	}
+	const verNTWorkstation = 0x00000001
+	return osviex.ProductType == verNTWorkstation
+}
+
+// Unmount is a platform-specific helper function to call
+// the unmount syscall. Not supported on Windows
+func Unmount(dest string) error {
+	return nil
+}
+
+// CommandLineToArgv wraps the Windows syscall to turn a commandline into an argument array.
+func CommandLineToArgv(commandLine string) ([]string, error) {
+	var argc int32
+
+	argsPtr, err := syscall.UTF16PtrFromString(commandLine)
+	if err != nil {
+		return nil, err
+	}
+
+	argv, err := syscall.CommandLineToArgv(argsPtr, &argc)
+	if err != nil {
+		return nil, err
+	}
+	defer syscall.LocalFree(syscall.Handle(uintptr(unsafe.Pointer(argv))))
+
+	newArgs := make([]string, argc)
+	for i, v := range (*argv)[:argc] {
+		newArgs[i] = string(syscall.UTF16ToString((*v)[:]))
+	}
+
+	return newArgs, nil
+}
+
+// HasWin32KSupport determines whether containers that depend on win32k can
+// run on this machine. Win32k is the driver used to implement windowing.
+func HasWin32KSupport() bool {
+	// For now, check for ntuser API support on the host. In the future, a host
+	// may support win32k in containers even if the host does not support ntuser
+	// APIs.
+	return ntuserApiset.Load() == nil
+}

vendor/github.com/docker/docker/pkg/system/umask.go

@@ -0,0 +1,13 @@
+// +build !windows
+
+package system
+
+import (
+	"syscall"
+)
+
+// Umask sets current process's file mode creation mask to newmask
+// and returns oldmask.
+func Umask(newmask int) (oldmask int, err error) {
+	return syscall.Umask(newmask), nil
+}

vendor/github.com/docker/docker/pkg/system/umask_windows.go

@@ -0,0 +1,9 @@
+// +build windows
+
+package system
+
+// Umask is not supported on the windows platform.
+func Umask(newmask int) (oldmask int, err error) {
+	// should not be called on cli code path
+	return 0, ErrNotSupportedPlatform
+}

vendor/github.com/docker/docker/pkg/system/utimes_freebsd.go

@@ -0,0 +1,22 @@
+package system
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+// LUtimesNano is used to change access and modification time of the specified path.
+// It's used for symbol link file because syscall.UtimesNano doesn't support a NOFOLLOW flag atm.
+func LUtimesNano(path string, ts []syscall.Timespec) error {
+	var _path *byte
+	_path, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return err
+	}
+
+	if _, _, err := syscall.Syscall(syscall.SYS_LUTIMES, uintptr(unsafe.Pointer(_path)), uintptr(unsafe.Pointer(&ts[0])), 0); err != 0 && err != syscall.ENOSYS {
+		return err
+	}
+
+	return nil
+}

vendor/github.com/docker/docker/pkg/system/utimes_linux.go

@@ -0,0 +1,26 @@
+package system
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+// LUtimesNano is used to change access and modification time of the specified path.
+// It's used for symbol link file because syscall.UtimesNano doesn't support a NOFOLLOW flag atm.
+func LUtimesNano(path string, ts []syscall.Timespec) error {
+	// These are not currently available in syscall
+	atFdCwd := -100
+	atSymLinkNoFollow := 0x100
+
+	var _path *byte
+	_path, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return err
+	}
+
+	if _, _, err := syscall.Syscall6(syscall.SYS_UTIMENSAT, uintptr(atFdCwd), uintptr(unsafe.Pointer(_path)), uintptr(unsafe.Pointer(&ts[0])), uintptr(atSymLinkNoFollow), 0, 0); err != 0 && err != syscall.ENOSYS {
+		return err
+	}
+
+	return nil
+}

vendor/github.com/docker/docker/pkg/system/utimes_unsupported.go

@@ -0,0 +1,10 @@
+// +build !linux,!freebsd
+
+package system
+
+import "syscall"
+
+// LUtimesNano is only supported on linux and freebsd.
+func LUtimesNano(path string, ts []syscall.Timespec) error {
+	return ErrNotSupportedPlatform
+}

vendor/github.com/docker/docker/pkg/system/xattrs_linux.go

@@ -0,0 +1,63 @@
+package system
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+// Lgetxattr retrieves the value of the extended attribute identified by attr
+// and associated with the given path in the file system.
+// It will returns a nil slice and nil error if the xattr is not set.
+func Lgetxattr(path string, attr string) ([]byte, error) {
+	pathBytes, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return nil, err
+	}
+	attrBytes, err := syscall.BytePtrFromString(attr)
+	if err != nil {
+		return nil, err
+	}
+
+	dest := make([]byte, 128)
+	destBytes := unsafe.Pointer(&dest[0])
+	sz, _, errno := syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(destBytes), uintptr(len(dest)), 0, 0)
+	if errno == syscall.ENODATA {
+		return nil, nil
+	}
+	if errno == syscall.ERANGE {
+		dest = make([]byte, sz)
+		destBytes := unsafe.Pointer(&dest[0])
+		sz, _, errno = syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(destBytes), uintptr(len(dest)), 0, 0)
+	}
+	if errno != 0 {
+		return nil, errno
+	}
+
+	return dest[:sz], nil
+}
+
+var _zero uintptr
+
+// Lsetxattr sets the value of the extended attribute identified by attr
+// and associated with the given path in the file system.
+func Lsetxattr(path string, attr string, data []byte, flags int) error {
+	pathBytes, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return err
+	}
+	attrBytes, err := syscall.BytePtrFromString(attr)
+	if err != nil {
+		return err
+	}
+	var dataBytes unsafe.Pointer
+	if len(data) > 0 {
+		dataBytes = unsafe.Pointer(&data[0])
+	} else {
+		dataBytes = unsafe.Pointer(&_zero)
+	}
+	_, _, errno := syscall.Syscall6(syscall.SYS_LSETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(dataBytes), uintptr(len(data)), uintptr(flags), 0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}

vendor/github.com/docker/docker/pkg/system/xattrs_unsupported.go

@@ -0,0 +1,13 @@
+// +build !linux
+
+package system
+
+// Lgetxattr is not supported on platforms other than linux.
+func Lgetxattr(path string, attr string) ([]byte, error) {
+	return nil, ErrNotSupportedPlatform
+}
+
+// Lsetxattr is not supported on platforms other than linux.
+func Lsetxattr(path string, attr string, data []byte, flags int) error {
+	return ErrNotSupportedPlatform
+}