DockerCLI/vendor/github.com/Microsoft/hcsshim/baselayer.go

172 lines
3.5 KiB
Go

package hcsshim
import (
"errors"
"os"
"path/filepath"
"syscall"
"github.com/Microsoft/go-winio"
)
type baseLayerWriter struct {
root *os.File
f *os.File
bw *winio.BackupFileWriter
err error
hasUtilityVM bool
dirInfo []dirInfo
}
type dirInfo struct {
path string
fileInfo winio.FileBasicInfo
}
// reapplyDirectoryTimes reapplies directory modification, creation, etc. times
// after processing of the directory tree has completed. The times are expected
// to be ordered such that parent directories come before child directories.
func reapplyDirectoryTimes(root *os.File, dis []dirInfo) error {
for i := range dis {
di := &dis[len(dis)-i-1] // reverse order: process child directories first
f, err := openRelative(di.path, root, syscall.GENERIC_READ|syscall.GENERIC_WRITE, syscall.FILE_SHARE_READ, _FILE_OPEN, _FILE_DIRECTORY_FILE)
if err != nil {
return err
}
err = winio.SetFileBasicInfo(f, &di.fileInfo)
f.Close()
if err != nil {
return err
}
}
return nil
}
func (w *baseLayerWriter) closeCurrentFile() error {
if w.f != nil {
err := w.bw.Close()
err2 := w.f.Close()
w.f = nil
w.bw = nil
if err != nil {
return err
}
if err2 != nil {
return err2
}
}
return nil
}
func (w *baseLayerWriter) Add(name string, fileInfo *winio.FileBasicInfo) (err error) {
defer func() {
if err != nil {
w.err = err
}
}()
err = w.closeCurrentFile()
if err != nil {
return err
}
if filepath.ToSlash(name) == `UtilityVM/Files` {
w.hasUtilityVM = true
}
var f *os.File
defer func() {
if f != nil {
f.Close()
}
}()
extraFlags := uint32(0)
if fileInfo.FileAttributes&syscall.FILE_ATTRIBUTE_DIRECTORY != 0 {
extraFlags |= _FILE_DIRECTORY_FILE
if fileInfo.FileAttributes&syscall.FILE_ATTRIBUTE_REPARSE_POINT == 0 {
w.dirInfo = append(w.dirInfo, dirInfo{name, *fileInfo})
}
}
mode := uint32(syscall.GENERIC_READ | syscall.GENERIC_WRITE | winio.WRITE_DAC | winio.WRITE_OWNER | winio.ACCESS_SYSTEM_SECURITY)
f, err = openRelative(name, w.root, mode, syscall.FILE_SHARE_READ, _FILE_CREATE, extraFlags)
if err != nil {
return makeError(err, "Failed to openRelative", name)
}
err = winio.SetFileBasicInfo(f, fileInfo)
if err != nil {
return makeError(err, "Failed to SetFileBasicInfo", name)
}
w.f = f
w.bw = winio.NewBackupFileWriter(f, true)
f = nil
return nil
}
func (w *baseLayerWriter) AddLink(name string, target string) (err error) {
defer func() {
if err != nil {
w.err = err
}
}()
err = w.closeCurrentFile()
if err != nil {
return err
}
return linkRelative(target, w.root, name, w.root)
}
func (w *baseLayerWriter) Remove(name string) error {
return errors.New("base layer cannot have tombstones")
}
func (w *baseLayerWriter) Write(b []byte) (int, error) {
n, err := w.bw.Write(b)
if err != nil {
w.err = err
}
return n, err
}
func (w *baseLayerWriter) Close() error {
defer func() {
w.root.Close()
w.root = nil
}()
err := w.closeCurrentFile()
if err != nil {
return err
}
if w.err == nil {
// Restore the file times of all the directories, since they may have
// been modified by creating child directories.
err = reapplyDirectoryTimes(w.root, w.dirInfo)
if err != nil {
return err
}
err = ProcessBaseLayer(w.root.Name())
if err != nil {
return err
}
if w.hasUtilityVM {
err := ensureNotReparsePointRelative("UtilityVM", w.root)
if err != nil {
return err
}
err = ProcessUtilityVMImage(filepath.Join(w.root.Name(), "UtilityVM"))
if err != nil {
return err
}
}
}
return w.err
}