rootfs: remove unused functions

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

rootfs/init.go

@@ -1,99 +0,0 @@
-package rootfs
-
-import (
-	"context"
-	"fmt"
-	"io/ioutil"
-	"os"
-
-	"github.com/containerd/containerd/log"
-	"github.com/containerd/containerd/mount"
-	"github.com/containerd/containerd/snapshot"
-	digest "github.com/opencontainers/go-digest"
-	"github.com/pkg/errors"
-)
-
-var (
-	initializers = map[string]initializerFunc{}
-)
-
-type initializerFunc func(string) error
-
-type Mounter interface {
-	Mount(target string, mounts ...mount.Mount) error
-	Unmount(target string) error
-}
-
-func InitRootFS(ctx context.Context, name string, parent digest.Digest, readonly bool, snapshotter snapshot.Snapshotter, mounter Mounter) ([]mount.Mount, error) {
-	_, err := snapshotter.Stat(ctx, name)
-	if err == nil {
-		return nil, errors.Errorf("rootfs already exists")
-	}
-	// TODO: ensure not exist error once added to snapshot package
-
-	parentS := parent.String()
-
-	initName := defaultInitializer
-	initFn := initializers[initName]
-	if initFn != nil {
-		parentS, err = createInitLayer(ctx, parentS, initName, initFn, snapshotter, mounter)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	if readonly {
-		return snapshotter.View(ctx, name, parentS)
-	}
-
-	return snapshotter.Prepare(ctx, name, parentS)
-}
-
-func createInitLayer(ctx context.Context, parent, initName string, initFn func(string) error, snapshotter snapshot.Snapshotter, mounter Mounter) (string, error) {
-	initS := fmt.Sprintf("%s %s", parent, initName)
-	if _, err := snapshotter.Stat(ctx, initS); err == nil {
-		return initS, nil
-	}
-	// TODO: ensure not exist error once added to snapshot package
-
-	// Create tempdir
-	td, err := ioutil.TempDir("", "create-init-")
-	if err != nil {
-		return "", err
-	}
-	defer os.RemoveAll(td)
-
-	mounts, err := snapshotter.Prepare(ctx, td, parent)
-	if err != nil {
-		return "", err
-	}
-	defer func() {
-		if err != nil {
-			// TODO: once implemented uncomment
-			//if rerr := snapshotter.Remove(ctx, td); rerr != nil {
-			//	log.G(ctx).Errorf("Failed to remove snapshot %s: %v", td, merr)
-			//}
-		}
-	}()
-
-	if err = mounter.Mount(td, mounts...); err != nil {
-		return "", err
-	}
-
-	if err = initFn(td); err != nil {
-		if merr := mounter.Unmount(td); merr != nil {
-			log.G(ctx).Errorf("Failed to unmount %s: %v", td, merr)
-		}
-		return "", err
-	}
-
-	if err = mounter.Unmount(td); err != nil {
-		return "", err
-	}
-
-	if err := snapshotter.Commit(ctx, initS, td); err != nil {
-		return "", err
-	}
-
-	return initS, nil
-}