layer/CreateRWLayerByGraphID: remove

This is an additon to commit 1fea38856a ("Remove v1.10 migrator")
aka PR #38265. Since that one, CreateRWLayerByGraphID() is not
used anywhere, so let's drop it.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

layer/migration.go

@@ -3,7 +3,6 @@ package layer // import "github.com/docker/docker/layer"
 import (
 	"compress/gzip"
 	"errors"
-	"fmt"
 	"io"
 	"os"
 
@@ -13,64 +12,6 @@ import (
 	"github.com/vbatts/tar-split/tar/storage"
 )
 
-// CreateRWLayerByGraphID creates a RWLayer in the layer store using
-// the provided name with the given graphID. To get the RWLayer
-// after migration the layer may be retrieved by the given name.
-func (ls *layerStore) CreateRWLayerByGraphID(name, graphID string, parent ChainID) (err error) {
-	ls.mountL.Lock()
-	m := ls.mounts[name]
-	ls.mountL.Unlock()
-	if m != nil {
-		if m.parent.chainID != parent {
-			return errors.New("name conflict, mismatched parent")
-		}
-		if m.mountID != graphID {
-			return errors.New("mount already exists")
-		}
-
-		return nil
-	}
-
-	if !ls.driver.Exists(graphID) {
-		return fmt.Errorf("graph ID does not exist: %q", graphID)
-	}
-
-	var p *roLayer
-	if string(parent) != "" {
-		p = ls.get(parent)
-		if p == nil {
-			return ErrLayerDoesNotExist
-		}
-
-		// Release parent chain if error
-		defer func() {
-			if err != nil {
-				ls.layerL.Lock()
-				ls.releaseLayer(p)
-				ls.layerL.Unlock()
-			}
-		}()
-	}
-
-	// TODO: Ensure graphID has correct parent
-
-	m = &mountedLayer{
-		name:       name,
-		parent:     p,
-		mountID:    graphID,
-		layerStore: ls,
-		references: map[RWLayer]*referencedRWLayer{},
-	}
-
-	// Check for existing init layer
-	initID := fmt.Sprintf("%s-init", graphID)
-	if ls.driver.Exists(initID) {
-		m.initID = initID
-	}
-
-	return ls.saveMount(m)
-}
-
 func (ls *layerStore) ChecksumForGraphID(id, parent, oldTarDataPath, newTarDataPath string) (diffID DiffID, size int64, err error) {
 	defer func() {
 		if err != nil {

layer/migration_test.go

@@ -3,7 +3,6 @@ package layer // import "github.com/docker/docker/layer"
 import (
 	"bytes"
 	"compress/gzip"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
@@ -12,7 +11,6 @@ import (
 	"testing"
 
 	"github.com/docker/docker/daemon/graphdriver"
-	"github.com/docker/docker/pkg/archive"
 	"github.com/docker/docker/pkg/stringid"
 	"github.com/vbatts/tar-split/tar/asm"
 	"github.com/vbatts/tar-split/tar/storage"
@@ -269,161 +267,3 @@ func TestLayerMigrationNoTarsplit(t *testing.T) {
 
 	assertMetadata(t, metadata, createMetadata(layer2a))
 }
-
-func TestMountMigration(t *testing.T) {
-	// TODO Windows: Figure out why this is failing (obvious - paths... needs porting)
-	if runtime.GOOS == "windows" {
-		t.Skip("Failing on Windows")
-	}
-	ls, _, cleanup := newTestStore(t)
-	defer cleanup()
-
-	baseFiles := []FileApplier{
-		newTestFile("/root/.bashrc", []byte("# Boring configuration"), 0644),
-		newTestFile("/etc/profile", []byte("# Base configuration"), 0644),
-	}
-	initFiles := []FileApplier{
-		newTestFile("/etc/hosts", []byte{}, 0644),
-		newTestFile("/etc/resolv.conf", []byte{}, 0644),
-	}
-	mountFiles := []FileApplier{
-		newTestFile("/etc/hosts", []byte("localhost 127.0.0.1"), 0644),
-		newTestFile("/root/.bashrc", []byte("# Updated configuration"), 0644),
-		newTestFile("/root/testfile1.txt", []byte("nothing valuable"), 0644),
-	}
-
-	initTar, err := tarFromFiles(initFiles...)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	mountTar, err := tarFromFiles(mountFiles...)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	graph := ls.(*layerStore).driver
-
-	layer1, err := createLayer(ls, "", initWithFiles(baseFiles...))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	graphID1 := layer1.(*referencedCacheLayer).cacheID
-
-	containerID := stringid.GenerateRandomID()
-	containerInit := fmt.Sprintf("%s-init", containerID)
-
-	if err := graph.Create(containerInit, graphID1, nil); err != nil {
-		t.Fatal(err)
-	}
-	if _, err := graph.ApplyDiff(containerInit, graphID1, bytes.NewReader(initTar)); err != nil {
-		t.Fatal(err)
-	}
-
-	if err := graph.Create(containerID, containerInit, nil); err != nil {
-		t.Fatal(err)
-	}
-	if _, err := graph.ApplyDiff(containerID, containerInit, bytes.NewReader(mountTar)); err != nil {
-		t.Fatal(err)
-	}
-
-	if err := ls.(*layerStore).CreateRWLayerByGraphID("migration-mount", containerID, layer1.ChainID()); err != nil {
-		t.Fatal(err)
-	}
-
-	rwLayer1, err := ls.GetRWLayer("migration-mount")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if _, err := rwLayer1.Mount(""); err != nil {
-		t.Fatal(err)
-	}
-
-	changes, err := rwLayer1.Changes()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if expected := 5; len(changes) != expected {
-		t.Logf("Changes %#v", changes)
-		t.Fatalf("Wrong number of changes %d, expected %d", len(changes), expected)
-	}
-
-	sortChanges(changes)
-
-	assertChange(t, changes[0], archive.Change{
-		Path: "/etc",
-		Kind: archive.ChangeModify,
-	})
-	assertChange(t, changes[1], archive.Change{
-		Path: "/etc/hosts",
-		Kind: archive.ChangeModify,
-	})
-	assertChange(t, changes[2], archive.Change{
-		Path: "/root",
-		Kind: archive.ChangeModify,
-	})
-	assertChange(t, changes[3], archive.Change{
-		Path: "/root/.bashrc",
-		Kind: archive.ChangeModify,
-	})
-	assertChange(t, changes[4], archive.Change{
-		Path: "/root/testfile1.txt",
-		Kind: archive.ChangeAdd,
-	})
-
-	if _, err := ls.CreateRWLayer("migration-mount", layer1.ChainID(), nil); err == nil {
-		t.Fatal("Expected error creating mount with same name")
-	} else if err != ErrMountNameConflict {
-		t.Fatal(err)
-	}
-
-	rwLayer2, err := ls.GetRWLayer("migration-mount")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if getMountLayer(rwLayer1) != getMountLayer(rwLayer2) {
-		t.Fatal("Expected same layer from get with same name as from migrate")
-	}
-
-	if _, err := rwLayer2.Mount(""); err != nil {
-		t.Fatal(err)
-	}
-
-	if _, err := rwLayer2.Mount(""); err != nil {
-		t.Fatal(err)
-	}
-
-	if metadata, err := ls.Release(layer1); err != nil {
-		t.Fatal(err)
-	} else if len(metadata) > 0 {
-		t.Fatalf("Expected no layers to be deleted, deleted %#v", metadata)
-	}
-
-	if err := rwLayer1.Unmount(); err != nil {
-		t.Fatal(err)
-	}
-
-	if _, err := ls.ReleaseRWLayer(rwLayer1); err != nil {
-		t.Fatal(err)
-	}
-
-	if err := rwLayer2.Unmount(); err != nil {
-		t.Fatal(err)
-	}
-	if err := rwLayer2.Unmount(); err != nil {
-		t.Fatal(err)
-	}
-	metadata, err := ls.ReleaseRWLayer(rwLayer2)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if len(metadata) == 0 {
-		t.Fatal("Expected base layer to be deleted when deleting mount")
-	}
-
-	assertMetadata(t, metadata, createMetadata(layer1))
-}