Merge pull request #22775 from Microsoft/jjh/removewindowsdiff

Windows: Remove windowsdiff graph driver

daemon/graphdriver/driver_windows.go

@@ -4,8 +4,6 @@ var (
 	// Slice of drivers that should be used in order
 	priority = []string{
 		"windowsfilter",
-		"windowsdiff",
-		"vfs",
 	}
 )
 

daemon/graphdriver/windows/windows.go

@@ -26,7 +26,6 @@ import (
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/daemon/graphdriver"
 	"github.com/docker/docker/pkg/archive"
-	"github.com/docker/docker/pkg/chrootarchive"
 	"github.com/docker/docker/pkg/idtools"
 	"github.com/docker/docker/pkg/ioutils"
 	"github.com/docker/docker/pkg/longpath"
@@ -35,28 +34,21 @@ import (
 	"github.com/vbatts/tar-split/tar/storage"
 )
 
+// filterDriver is an HCSShim driver type for the Windows Filter driver.
+const filterDriver = 1
+
 // init registers the windows graph drivers to the register.
 func init() {
 	graphdriver.Register("windowsfilter", InitFilter)
-	graphdriver.Register("windowsdiff", InitDiff)
 	reexec.Register("docker-windows-write-layer", writeLayer)
 }
 
-const (
-	// diffDriver is an hcsshim driver type
-	diffDriver = iota
-	// filterDriver is an hcsshim driver type
-	filterDriver
-)
-
 // Driver represents a windows graph driver.
 type Driver struct {
 	// info stores the shim driver information
 	info hcsshim.DriverInfo
 }
 
-var _ graphdriver.DiffGetterDriver = &Driver{}
-
 func isTP5OrOlder() bool {
 	return system.GetOSVersion().Build <= 14300
 }
@@ -73,28 +65,9 @@ func InitFilter(home string, options []string, uidMaps, gidMaps []idtools.IDMap)
 	return d, nil
 }
 
-// InitDiff returns a new Windows differencing disk driver.
-func InitDiff(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
-	logrus.Debugf("WindowsGraphDriver InitDiff at %s", home)
-	d := &Driver{
-		info: hcsshim.DriverInfo{
-			HomeDir: home,
-			Flavour: diffDriver,
-		},
-	}
-	return d, nil
-}
-
 // String returns the string representation of a driver.
 func (d *Driver) String() string {
-	switch d.info.Flavour {
+	return "Windows filter storage driver"
-	case diffDriver:
-		return "windowsdiff"
-	case filterDriver:
-		return "windowsfilter"
-	default:
-		return "Unknown driver flavour"
-	}
 }
 
 // Status returns the status of the driver.
@@ -390,20 +363,6 @@ func (d *Driver) Changes(id, parent string) ([]archive.Change, error) {
 // new layer in bytes.
 // The layer should not be mounted when calling this function
 func (d *Driver) ApplyDiff(id, parent string, diff archive.Reader) (int64, error) {
-	if d.info.Flavour == diffDriver {
-		start := time.Now().UTC()
-		logrus.Debugf("WindowsGraphDriver ApplyDiff: Start untar layer")
-		destination := d.dir(id)
-		destination = filepath.Dir(destination)
-		size, err := chrootarchive.ApplyUncompressedLayer(destination, diff, nil)
-		if err != nil {
-			return 0, err
-		}
-		logrus.Debugf("WindowsGraphDriver ApplyDiff: Untar time: %vs", time.Now().UTC().Sub(start).Seconds())
-
-		return size, nil
-	}
-
 	var layerChain []string
 	if parent != "" {
 		rPId, err := d.resolveID(parent)