Ensure opaque directory permissions respected

When converting an opaque directory always keep the original
directory tar entry to ensure directory is created with correct
permissions on restore.

Closes #27298

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
This commit is contained in:
Derek McGowan 2016-10-24 17:03:56 -07:00
parent 6756f1d160
commit 50841b16fe
No known key found for this signature in database
GPG key ID: F58C5D0A4405ACDB
3 changed files with 213 additions and 6 deletions

View file

@ -243,7 +243,7 @@ func (compression *Compression) Extension() string {
}
type tarWhiteoutConverter interface {
ConvertWrite(*tar.Header, string, os.FileInfo) error
ConvertWrite(*tar.Header, string, os.FileInfo) (*tar.Header, error)
ConvertRead(*tar.Header, string) (bool, error)
}
@ -350,9 +350,25 @@ func (ta *tarAppender) addTarFile(path, name string) error {
}
if ta.WhiteoutConverter != nil {
if err := ta.WhiteoutConverter.ConvertWrite(hdr, path, fi); err != nil {
wo, err := ta.WhiteoutConverter.ConvertWrite(hdr, path, fi)
if err != nil {
return err
}
// If a new whiteout file exists, write original hdr, then
// replace hdr with wo to be written after. Whiteouts should
// always be written after the original. Note the original
// hdr may have been updated to be a whiteout with returning
// a whiteout header
if wo != nil {
if err := ta.TarWriter.WriteHeader(hdr); err != nil {
return err
}
if hdr.Typeflag == tar.TypeReg && hdr.Size > 0 {
return fmt.Errorf("tar: cannot use whiteout for non-empty file")
}
hdr = wo
}
}
if err := ta.TarWriter.WriteHeader(hdr); err != nil {

View file

@ -19,7 +19,7 @@ func getWhiteoutConverter(format WhiteoutFormat) tarWhiteoutConverter {
type overlayWhiteoutConverter struct{}
func (overlayWhiteoutConverter) ConvertWrite(hdr *tar.Header, path string, fi os.FileInfo) error {
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
@ -34,12 +34,16 @@ func (overlayWhiteoutConverter) ConvertWrite(hdr *tar.Header, path string, fi os
// 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 err
return nil, err
}
if opaque != nil && 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
*hdr = tar.Header{
wo = &tar.Header{
Typeflag: tar.TypeReg,
Mode: hdr.Mode & int64(os.ModePerm),
Name: filepath.Join(hdr.Name, WhiteoutOpaqueDir),
@ -54,7 +58,7 @@ func (overlayWhiteoutConverter) ConvertWrite(hdr *tar.Header, path string, fi os
}
}
return nil
return
}
func (overlayWhiteoutConverter) ConvertRead(hdr *tar.Header, path string) (bool, error) {

View file

@ -0,0 +1,187 @@
package archive
import (
"io/ioutil"
"os"
"path/filepath"
"syscall"
"testing"
"github.com/docker/docker/pkg/system"
)
// setupOverlayTestDir creates files in a directory with overlay whiteouts
// Tree layout
// .
// ├── d1 # opaque, 0700
// │   └── f1 # empty file, 0600
// ├── d2 # opaque, 0750
// │   └── f1 # empty file, 0660
// └── d3 # 0700
// └── f1 # whiteout, 0644
func setupOverlayTestDir(t *testing.T, src string) {
// Create opaque directory containing single file and permission 0700
if err := os.Mkdir(filepath.Join(src, "d1"), 0700); err != nil {
t.Fatal(err)
}
if err := system.Lsetxattr(filepath.Join(src, "d1"), "trusted.overlay.opaque", []byte("y"), 0); err != nil {
t.Fatal(err)
}
if err := ioutil.WriteFile(filepath.Join(src, "d1", "f1"), []byte{}, 0600); err != nil {
t.Fatal(err)
}
// Create another opaque directory containing single file but with permission 0750
if err := os.Mkdir(filepath.Join(src, "d2"), 0750); err != nil {
t.Fatal(err)
}
if err := system.Lsetxattr(filepath.Join(src, "d2"), "trusted.overlay.opaque", []byte("y"), 0); err != nil {
t.Fatal(err)
}
if err := ioutil.WriteFile(filepath.Join(src, "d2", "f1"), []byte{}, 0660); err != nil {
t.Fatal(err)
}
// Create regular directory with deleted file
if err := os.Mkdir(filepath.Join(src, "d3"), 0700); err != nil {
t.Fatal(err)
}
if err := system.Mknod(filepath.Join(src, "d3", "f1"), syscall.S_IFCHR, 0); err != nil {
t.Fatal(err)
}
}
func checkOpaqueness(t *testing.T, path string, opaque string) {
xattrOpaque, err := system.Lgetxattr(path, "trusted.overlay.opaque")
if err != nil {
t.Fatal(err)
}
if string(xattrOpaque) != opaque {
t.Fatalf("Unexpected opaque value: %q, expected %q", string(xattrOpaque), opaque)
}
}
func checkOverlayWhiteout(t *testing.T, path string) {
stat, err := os.Stat(path)
if err != nil {
t.Fatal(err)
}
statT, ok := stat.Sys().(*syscall.Stat_t)
if !ok {
t.Fatalf("Unexpected type: %t, expected *syscall.Stat_t", stat.Sys())
}
if statT.Rdev != 0 {
t.Fatalf("Non-zero device number for whiteout")
}
}
func checkFileMode(t *testing.T, path string, perm os.FileMode) {
stat, err := os.Stat(path)
if err != nil {
t.Fatal(err)
}
if stat.Mode() != perm {
t.Fatalf("Unexpected file mode for %s: %o, expected %o", path, stat.Mode(), perm)
}
}
func TestOverlayTarUntar(t *testing.T) {
oldmask, err := system.Umask(0)
if err != nil {
t.Fatal(err)
}
defer system.Umask(oldmask)
src, err := ioutil.TempDir("", "docker-test-overlay-tar-src")
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(src)
setupOverlayTestDir(t, src)
dst, err := ioutil.TempDir("", "docker-test-overlay-tar-dst")
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(dst)
options := &TarOptions{
Compression: Uncompressed,
WhiteoutFormat: OverlayWhiteoutFormat,
}
archive, err := TarWithOptions(src, options)
if err != nil {
t.Fatal(err)
}
defer archive.Close()
if err := Untar(archive, dst, options); err != nil {
t.Fatal(err)
}
checkFileMode(t, filepath.Join(dst, "d1"), 0700|os.ModeDir)
checkFileMode(t, filepath.Join(dst, "d2"), 0750|os.ModeDir)
checkFileMode(t, filepath.Join(dst, "d3"), 0700|os.ModeDir)
checkFileMode(t, filepath.Join(dst, "d1", "f1"), 0600)
checkFileMode(t, filepath.Join(dst, "d2", "f1"), 0660)
checkFileMode(t, filepath.Join(dst, "d3", "f1"), os.ModeCharDevice|os.ModeDevice)
checkOpaqueness(t, filepath.Join(dst, "d1"), "y")
checkOpaqueness(t, filepath.Join(dst, "d2"), "y")
checkOpaqueness(t, filepath.Join(dst, "d3"), "")
checkOverlayWhiteout(t, filepath.Join(dst, "d3", "f1"))
}
func TestOverlayTarAUFSUntar(t *testing.T) {
oldmask, err := system.Umask(0)
if err != nil {
t.Fatal(err)
}
defer system.Umask(oldmask)
src, err := ioutil.TempDir("", "docker-test-overlay-tar-src")
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(src)
setupOverlayTestDir(t, src)
dst, err := ioutil.TempDir("", "docker-test-overlay-tar-dst")
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(dst)
archive, err := TarWithOptions(src, &TarOptions{
Compression: Uncompressed,
WhiteoutFormat: OverlayWhiteoutFormat,
})
if err != nil {
t.Fatal(err)
}
defer archive.Close()
if err := Untar(archive, dst, &TarOptions{
Compression: Uncompressed,
WhiteoutFormat: AUFSWhiteoutFormat,
}); err != nil {
t.Fatal(err)
}
checkFileMode(t, filepath.Join(dst, "d1"), 0700|os.ModeDir)
checkFileMode(t, filepath.Join(dst, "d1", WhiteoutOpaqueDir), 0700)
checkFileMode(t, filepath.Join(dst, "d2"), 0750|os.ModeDir)
checkFileMode(t, filepath.Join(dst, "d2", WhiteoutOpaqueDir), 0750)
checkFileMode(t, filepath.Join(dst, "d3"), 0700|os.ModeDir)
checkFileMode(t, filepath.Join(dst, "d1", "f1"), 0600)
checkFileMode(t, filepath.Join(dst, "d2", "f1"), 0660)
checkFileMode(t, filepath.Join(dst, "d3", WhiteoutPrefix+"f1"), 0600)
}