@@ -28,7 +28,7 @@ func copyOwnership(source, destination string) error {

 		return err

 	}

-	if err := os.Chown(destination, int(stat.Uid()), int(stat.Gid())); err != nil {

+	if err := os.Chown(destination, int(stat.UID()), int(stat.Gid())); err != nil {

 		return err

 	}

@@ -26,7 +26,7 @@ func setPlatformServerConfig(serverConfig *apiserver.Config, daemonCfg *daemon.C

 // file.

 func currentUserIsOwner(f string) bool {

 	if fileInfo, err := system.Stat(f); err == nil && fileInfo != nil {

-		if int(fileInfo.Uid()) == os.Getuid() {

+		if int(fileInfo.UID()) == os.Getuid() {

 			return true

 		}

 	}

@@ -76,11 +76,13 @@ packages=(

 	pkg/reexec

 	pkg/signal

 	pkg/sockets

+	pkg/stdcopy

 	pkg/streamformatter

 	pkg/stringid

 	pkg/stringutils

-	pkg/sysinfo

 	pkg/symlink

+	pkg/sysinfo

+	pkg/system

 	pkg/tailfile

 	pkg/tarsum

 	pkg/term

@@ -173,7 +173,7 @@ func Changes(layers []string, rw string) ([]Change, error) {

 type FileInfo struct {

 	parent     *FileInfo

 	name       string

-	stat       *system.Stat_t

+	stat       *system.StatT

 	children   map[string]*FileInfo

 	capability []byte

 	added      bool

@@ -8,10 +8,10 @@ import (

 	"github.com/docker/docker/pkg/system"

 )

-func statDifferent(oldStat *system.Stat_t, newStat *system.Stat_t) bool {

+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.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

@@ -4,7 +4,7 @@ import (

 	"github.com/docker/docker/pkg/system"

 )

-func statDifferent(oldStat *system.Stat_t, newStat *system.Stat_t) bool {

+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() ||

@@ -9,19 +9,24 @@ import (

 )

 const (

-	StdWriterPrefixLen = 8

-	StdWriterFdIndex   = 0

-	StdWriterSizeIndex = 4

+	stdWriterPrefixLen = 8

+	stdWriterFdIndex   = 0

+	stdWriterSizeIndex = 4

 )

-type StdType [StdWriterPrefixLen]byte

+// StdType prefixes type and length to standard stream.

+type StdType [stdWriterPrefixLen]byte

 var (

-	Stdin  StdType = StdType{0: 0}

-	Stdout StdType = StdType{0: 1}

-	Stderr StdType = StdType{0: 2}

+	// Stdin represents standard input stream type.

+	Stdin = StdType{0: 0}

+	// Stdout represents standard output stream type.

+	Stdout = StdType{0: 1}

+	// Stderr represents standard error steam type.

+	Stderr = StdType{0: 2}

 )

+// StdWriter is wrapper of io.Writer with extra customized info.

 type StdWriter struct {

 	io.Writer

 	prefix  StdType

@@ -36,10 +41,10 @@ func (w *StdWriter) Write(buf []byte) (n int, err error) {

 	binary.BigEndian.PutUint32(w.prefix[4:], uint32(len(buf)))

 	n1, err = w.Writer.Write(w.prefix[:])

 	if err != nil {

-		n = n1 - StdWriterPrefixLen

+		n = n1 - stdWriterPrefixLen

 	} else {

 		n2, err = w.Writer.Write(buf)

-		n = n1 + n2 - StdWriterPrefixLen

+		n = n1 + n2 - stdWriterPrefixLen

 	}

 	if n < 0 {

 		n = 0

@@ -61,7 +66,7 @@ func NewStdWriter(w io.Writer, t StdType) *StdWriter {

 	}

 }

-var ErrInvalidStdHeader = errors.New("Unrecognized input header")

+var errInvalidStdHeader = errors.New("Unrecognized input header")

 // StdCopy is a modified version of io.Copy.

 //

@@ -75,7 +80,7 @@ var ErrInvalidStdHeader = errors.New("Unrecognized input header")

 // `written` will hold the total number of bytes written to `dstout` and `dsterr`.

 func StdCopy(dstout, dsterr io.Writer, src io.Reader) (written int64, err error) {

 	var (

-		buf       = make([]byte, 32*1024+StdWriterPrefixLen+1)

+		buf       = make([]byte, 32*1024+stdWriterPrefixLen+1)

 		bufLen    = len(buf)

 		nr, nw    int

 		er, ew    error

@@ -85,12 +90,12 @@ func StdCopy(dstout, dsterr io.Writer, src io.Reader) (written int64, err error)

 	for {

 		// Make sure we have at least a full header

-		for nr < StdWriterPrefixLen {

+		for nr < stdWriterPrefixLen {

 			var nr2 int

 			nr2, er = src.Read(buf[nr:])

 			nr += nr2

 			if er == io.EOF {

-				if nr < StdWriterPrefixLen {

+				if nr < stdWriterPrefixLen {

 					logrus.Debugf("Corrupted prefix: %v", buf[:nr])

 					return written, nil

 				}

@@ -103,7 +108,7 @@ func StdCopy(dstout, dsterr io.Writer, src io.Reader) (written int64, err error)

 		}

 		// Check the first byte to know where to write

-		switch buf[StdWriterFdIndex] {

+		switch buf[stdWriterFdIndex] {

 		case 0:

 			fallthrough

 		case 1:

@@ -113,30 +118,30 @@ func StdCopy(dstout, dsterr io.Writer, src io.Reader) (written int64, err error)

 			// Write on stderr

 			out = dsterr

 		default:

-			logrus.Debugf("Error selecting output fd: (%d)", buf[StdWriterFdIndex])

-			return 0, ErrInvalidStdHeader

+			logrus.Debugf("Error selecting output fd: (%d)", buf[stdWriterFdIndex])

+			return 0, errInvalidStdHeader

 		}

 		// Retrieve the size of the frame

-		frameSize = int(binary.BigEndian.Uint32(buf[StdWriterSizeIndex : StdWriterSizeIndex+4]))

+		frameSize = int(binary.BigEndian.Uint32(buf[stdWriterSizeIndex : stdWriterSizeIndex+4]))

 		logrus.Debugf("framesize: %d", frameSize)

 		// Check if the buffer is big enough to read the frame.

 		// Extend it if necessary.

-		if frameSize+StdWriterPrefixLen > bufLen {

-			logrus.Debugf("Extending buffer cap by %d (was %d)", frameSize+StdWriterPrefixLen-bufLen+1, len(buf))

-			buf = append(buf, make([]byte, frameSize+StdWriterPrefixLen-bufLen+1)...)

+		if frameSize+stdWriterPrefixLen > bufLen {

+			logrus.Debugf("Extending buffer cap by %d (was %d)", frameSize+stdWriterPrefixLen-bufLen+1, len(buf))

+			buf = append(buf, make([]byte, frameSize+stdWriterPrefixLen-bufLen+1)...)

 			bufLen = len(buf)

 		}

 		// While the amount of bytes read is less than the size of the frame + header, we keep reading

-		for nr < frameSize+StdWriterPrefixLen {

+		for nr < frameSize+stdWriterPrefixLen {

 			var nr2 int

 			nr2, er = src.Read(buf[nr:])

 			nr += nr2

 			if er == io.EOF {

-				if nr < frameSize+StdWriterPrefixLen {

-					logrus.Debugf("Corrupted frame: %v", buf[StdWriterPrefixLen:nr])

+				if nr < frameSize+stdWriterPrefixLen {

+					logrus.Debugf("Corrupted frame: %v", buf[stdWriterPrefixLen:nr])

 					return written, nil

 				}

 				break

@@ -148,7 +153,7 @@ func StdCopy(dstout, dsterr io.Writer, src io.Reader) (written int64, err error)

 		}

 		// Write the retrieved frame (without header)

-		nw, ew = out.Write(buf[StdWriterPrefixLen : frameSize+StdWriterPrefixLen])

+		nw, ew = out.Write(buf[stdWriterPrefixLen : frameSize+stdWriterPrefixLen])

 		if ew != nil {

 			logrus.Debugf("Error writing frame: %s", ew)

 			return 0, ew

@@ -161,8 +166,8 @@ func StdCopy(dstout, dsterr io.Writer, src io.Reader) (written int64, err error)

 		written += int64(nw)

 		// Move the rest of the buffer to the beginning

-		copy(buf, buf[frameSize+StdWriterPrefixLen:])

+		copy(buf, buf[frameSize+stdWriterPrefixLen:])

 		// Move the index

-		nr -= frameSize + StdWriterPrefixLen

+		nr -= frameSize + stdWriterPrefixLen

 	}

 }

@@ -5,5 +5,6 @@ import (

 )

 var (

+	// ErrNotSupportedPlatform means the platform is not supported.

 	ErrNotSupportedPlatform = errors.New("platform and architecture is not supported")

 )

@@ -8,11 +8,6 @@ import (

 	"unsafe"

 )

-const (

-	EVENT_ALL_ACCESS    = 0x1F0003

-	EVENT_MODIFY_STATUS = 0x0002

-)

-

 var (

 	procCreateEvent = modkernel32.NewProc("CreateEventW")

 	procOpenEvent   = modkernel32.NewProc("OpenEventW")

@@ -21,13 +16,14 @@ var (

 	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 = 0

+	var _p1 uint32

 	if manualReset {

 		_p1 = 1

 	}

-	var _p2 uint32 = 0

+	var _p2 uint32

 	if initialState {

 		_p2 = 1

 	}

@@ -40,9 +36,10 @@ func CreateEvent(eventAttributes *syscall.SecurityAttributes, manualReset bool,

 	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 = 0

+	var _p1 uint32

 	if inheritHandle {

 		_p1 = 1

 	}

@@ -55,14 +52,17 @@ func OpenEvent(desiredAccess uint32, inheritHandle bool, name string) (handle sy

 	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)

 }

@@ -6,6 +6,8 @@ import (

 	"os"

 )

+// 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)

 }

@@ -7,10 +7,10 @@ import (

 )

 // Lstat takes a path to a file and returns

-// a system.Stat_t type pertaining to that file.

+// a system.StatT type pertaining to that file.

 //

 // Throws an error if the file does not exist

-func Lstat(path string) (*Stat_t, error) {

+func Lstat(path string) (*StatT, error) {

 	s := &syscall.Stat_t{}

 	if err := syscall.Lstat(path, s); err != nil {

 		return nil, err

@@ -6,21 +6,17 @@ import (

 	"os"

 )

-// Some explanation for my own sanity, and hopefully maintainers in the

-// future.

-//

 // 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) (*Stat_t, error) {

+func Lstat(path string) (*StatT, error) {

 	fi, err := os.Lstat(path)

 	if err != nil {

 		return nil, err

 	}

-	return &Stat_t{

+	return &StatT{

 		name:    fi.Name(),

 		size:    fi.Size(),

 		mode:    fi.Mode(),

@@ -2,7 +2,6 @@ package system

 import (

 	"bufio"

-	"errors"

 	"io"

 	"os"

 	"strconv"

@@ -11,10 +10,6 @@ import (

 	"github.com/docker/docker/pkg/units"

 )

-var (

-	ErrMalformed = errors.New("malformed file")

-)

-

 // ReadMemInfo retrieves memory statistics of the host system and returns a

 //  MemInfo type.

 func ReadMemInfo() (*MemInfo, error) {

@@ -2,6 +2,7 @@

 package system

+// ReadMemInfo is not supported on platforms other than linux and windows.

 func ReadMemInfo() (*MemInfo, error) {

 	return nil, ErrNotSupportedPlatform

 }

@@ -7,14 +7,16 @@ import (

 )

 // Mknod creates a filesystem node (file, device special file or named pipe) named path

-// with attributes specified by mode and dev

+// 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

+// 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))

 }

@@ -2,10 +2,12 @@

 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.")

 }

@@ -6,9 +6,9 @@ import (

 	"syscall"

 )

-// Stat_t type contains status of a file. It contains metadata

-// like permission, owner, group, size, etc about a file

-type Stat_t struct {

+// 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

@@ -17,30 +17,37 @@ type Stat_t struct {

 	mtim syscall.Timespec

 }

-func (s Stat_t) Mode() uint32 {

+// Mode returns file's permission mode.

+func (s StatT) Mode() uint32 {

 	return s.mode

 }

-func (s Stat_t) Uid() uint32 {

+// UID returns file's user id of owner.

+func (s StatT) UID() uint32 {

 	return s.uid

 }

-func (s Stat_t) Gid() uint32 {

+// Gid returns file's group id of owner.

+func (s StatT) Gid() uint32 {

 	return s.gid

 }

-func (s Stat_t) Rdev() uint64 {

+// Rdev returns file's device ID (if it's special file).

+func (s StatT) Rdev() uint64 {

 	return s.rdev

 }

-func (s Stat_t) Size() int64 {

+// Size returns file's size.

+func (s StatT) Size() int64 {

 	return s.size

 }

-func (s Stat_t) Mtim() syscall.Timespec {

+// Mtim returns file's last modification time.

+func (s StatT) Mtim() syscall.Timespec {

 	return s.mtim

 }

-func (s Stat_t) GetLastModification() syscall.Timespec {

+// GetLastModification returns file's last modification time.

+func (s StatT) GetLastModification() syscall.Timespec {

 	return s.Mtim()

 }

@@ -5,8 +5,8 @@ import (

 )

 // fromStatT converts a syscall.Stat_t type to a system.Stat_t type

-func fromStatT(s *syscall.Stat_t) (*Stat_t, error) {

-	return &Stat_t{size: s.Size,

+func fromStatT(s *syscall.Stat_t) (*StatT, error) {

+	return &StatT{size: s.Size,

 		mode: uint32(s.Mode),

 		uid:  s.Uid,

 		gid:  s.Gid,

@@ -18,7 +18,7 @@ func fromStatT(s *syscall.Stat_t) (*Stat_t, error) {

 // a system.Stat_t type pertaining to that file.

 //

 // Throws an error if the file does not exist

-func Stat(path string) (*Stat_t, error) {

+func Stat(path string) (*StatT, error) {

 	s := &syscall.Stat_t{}

 	if err := syscall.Stat(path, s); err != nil {

 		return nil, err

@@ -5,8 +5,8 @@ import (

 )

 // fromStatT converts a syscall.Stat_t type to a system.Stat_t type

-func fromStatT(s *syscall.Stat_t) (*Stat_t, error) {

-	return &Stat_t{size: s.Size,

+func fromStatT(s *syscall.Stat_t) (*StatT, error) {

+	return &StatT{size: s.Size,

 		mode: s.Mode,

 		uid:  s.Uid,

 		gid:  s.Gid,

@@ -14,17 +14,17 @@ func fromStatT(s *syscall.Stat_t) (*Stat_t, error) {

 		mtim: s.Mtim}, nil

 }

-// FromStatT exists only on linux, and loads a system.Stat_t from a

+// FromStatT exists only on linux, and loads a system.StatT from a

 // syscal.Stat_t.

-func FromStatT(s *syscall.Stat_t) (*Stat_t, error) {

+func FromStatT(s *syscall.Stat_t) (*StatT, error) {

 	return fromStatT(s)

 }

 // Stat takes a path to a file and returns

-// a system.Stat_t type pertaining to that file.

+// a system.StatT type pertaining to that file.

 //

 // Throws an error if the file does not exist

-func Stat(path string) (*Stat_t, error) {

+func Stat(path string) (*StatT, error) {

 	s := &syscall.Stat_t{}

 	if err := syscall.Stat(path, s); err != nil {

 		return nil, err

@@ -22,7 +22,7 @@ func TestFromStatT(t *testing.T) {

 	if stat.Mode != s.Mode() {

 		t.Fatal("got invalid mode")

 	}

-	if stat.Uid != s.Uid() {

+	if stat.Uid != s.UID() {

 		t.Fatal("got invalid uid")

 	}

 	if stat.Gid != s.Gid() {

@@ -6,9 +6,9 @@ import (

 	"syscall"

 )

-// fromStatT creates a system.Stat_t type from a syscall.Stat_t type

-func fromStatT(s *syscall.Stat_t) (*Stat_t, error) {

-	return &Stat_t{size: s.Size,

+// 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,

@@ -7,7 +7,9 @@ import (

 	"time"

 )

-type Stat_t struct {

+// 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

@@ -15,22 +17,27 @@ type Stat_t struct {

 	isDir   bool

 }

-func (s Stat_t) Name() string {

+// Name returns file's name.

+func (s StatT) Name() string {

 	return s.name

 }

-func (s Stat_t) Size() int64 {

+// Size returns file's size.

+func (s StatT) Size() int64 {

 	return s.size

 }

-func (s Stat_t) Mode() os.FileMode {

+// Mode returns file's permission mode.

+func (s StatT) Mode() os.FileMode {

 	return s.mode

 }

-func (s Stat_t) ModTime() time.Time {

+// ModTime returns file's last modification time.

+func (s StatT) ModTime() time.Time {

 	return s.modTime

 }

-func (s Stat_t) IsDir() bool {

+// IsDir returns whether file is actually a directory.

+func (s StatT) IsDir() bool {

 	return s.isDir

 }

@@ -6,6 +6,8 @@ import (

 	"syscall"

 )

+// Umask sets current process's file mode creation mask to newmask

+// and return oldmask.

 func Umask(newmask int) (oldmask int, err error) {

 	return syscall.Umask(newmask), nil

 }

@@ -2,6 +2,7 @@

 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

@@ -2,10 +2,13 @@ package system

 import "syscall"

+// LUtimesNano is not supported by darwin platform.

 func LUtimesNano(path string, ts []syscall.Timespec) error {

 	return ErrNotSupportedPlatform

 }

+// UtimesNano is used to change access and modification time of path.

+// it can't be used for symbol link file.

 func UtimesNano(path string, ts []syscall.Timespec) error {

 	return syscall.UtimesNano(path, ts)

 }

@@ -5,6 +5,8 @@ import (

 	"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)

@@ -19,6 +21,8 @@ func LUtimesNano(path string, ts []syscall.Timespec) error {

 	return nil

 }

+// UtimesNano is used to change access and modification time of the specified path.

+// It can't be used for symbol link file.

 func UtimesNano(path string, ts []syscall.Timespec) error {

 	return syscall.UtimesNano(path, ts)

 }

@@ -5,10 +5,12 @@ import (

 	"unsafe"

 )

+// LUtimesNano is used to change access and modification time of the speficied 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

-	AT_FDCWD := -100

-	AT_SYMLINK_NOFOLLOW := 0x100

+	atFdCwd := -100

+	atSymLinkNoFollow := 0x100

 	var _path *byte

 	_path, err := syscall.BytePtrFromString(path)

@@ -16,13 +18,15 @@ func LUtimesNano(path string, ts []syscall.Timespec) error {

 		return err

 	}

-	if _, _, err := syscall.Syscall6(syscall.SYS_UTIMENSAT, uintptr(AT_FDCWD), uintptr(unsafe.Pointer(_path)), uintptr(unsafe.Pointer(&ts[0])), uintptr(AT_SYMLINK_NOFOLLOW), 0, 0); err != 0 && err != syscall.ENOSYS {

+	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

 }

+// UtimesNano is used to change access and modification time of the specified path.

+// It can't be used for symbol link file.

 func UtimesNano(path string, ts []syscall.Timespec) error {

 	return syscall.UtimesNano(path, ts)

 }

@@ -4,10 +4,12 @@ package system

 import "syscall"

+// LUtimesNano is not supported on platforms other than linux, freebsd and darwin.

 func LUtimesNano(path string, ts []syscall.Timespec) error {

 	return ErrNotSupportedPlatform

 }

+// UtimesNano is not supported on platforms other than linux, freebsd and darwin.

 func UtimesNano(path string, ts []syscall.Timespec) error {

 	return ErrNotSupportedPlatform

 }

@@ -5,7 +5,9 @@ import (

 	"unsafe"

 )

-// Returns a nil slice and nil error if the xattr is not set

+// 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 {

@@ -36,6 +38,8 @@ func Lgetxattr(path string, attr string) ([]byte, error) {

 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 {

@@ -2,10 +2,12 @@

 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

 }