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* Rootfs dir is created during container creation not during bundle
  creation
* Add support for v2
* UnmountAll is a no-op when the path to unmount (i.e. the rootfs dir)
  does not exist or is invalid

Co-authored-by: Danail Branekov <danailster@gmail.com>
Signed-off-by: Georgi Sabev <georgethebeatle@gmail.com>

runtime/v1/linux/bundle.go

@@ -65,9 +65,6 @@ func newBundle(id, path, workDir string, spec []byte) (b *bundle, err error) {
 			os.RemoveAll(workDir)
 		}
 	}()
-	if err := os.Mkdir(filepath.Join(path, "rootfs"), 0711); err != nil {
-		return nil, err
-	}
 	err = ioutil.WriteFile(filepath.Join(path, configFilename), spec, 0666)
 	return &bundle{
 		id:      id,

runtime/v1/linux/proc/init.go

@@ -304,12 +304,10 @@ func (p *Init) delete(ctx context.Context) error {
 		}
 		p.io.Close()
 	}
-	if p.Rootfs != "" {
-		if err2 := mount.UnmountAll(p.Rootfs, 0); err2 != nil {
-			log.G(ctx).WithError(err2).Warn("failed to cleanup rootfs mount")
-			if err == nil {
-				err = errors.Wrap(err2, "failed rootfs umount")
-			}
+	if err2 := mount.UnmountAll(p.Rootfs, 0); err2 != nil {
+		log.G(ctx).WithError(err2).Warn("failed to cleanup rootfs mount")
+		if err == nil {
+			err = errors.Wrap(err2, "failed rootfs umount")
 		}
 	}
 	return err

runtime/v1/shim/service.go

@@ -124,6 +124,14 @@ func (s *Service) Create(ctx context.Context, r *shimapi.CreateTaskRequest) (_ *
 		})
 	}
 
+	rootfs := ""
+	if len(mounts) > 0 {
+		rootfs = filepath.Join(r.Bundle, "rootfs")
+		if err := os.Mkdir(rootfs, 0711); err != nil {
+			return nil, err
+		}
+	}
+
 	config := &proc.CreateConfig{
 		ID:               r.ID,
 		Bundle:           r.Bundle,
@@ -137,14 +145,13 @@ func (s *Service) Create(ctx context.Context, r *shimapi.CreateTaskRequest) (_ *
 		ParentCheckpoint: r.ParentCheckpoint,
 		Options:          r.Options,
 	}
-	rootfs := filepath.Join(r.Bundle, "rootfs")
-	defer func(rootfs string) {
+	defer func() {
 		if err != nil {
 			if err2 := mount.UnmountAll(rootfs, 0); err2 != nil {
 				log.G(ctx).WithError(err2).Warn("Failed to cleanup rootfs mount")
 			}
 		}
-	}(rootfs)
+	}()
 	for _, rm := range mounts {
 		m := &mount.Mount{
 			Type:    rm.Type,
@@ -159,10 +166,6 @@ func (s *Service) Create(ctx context.Context, r *shimapi.CreateTaskRequest) (_ *
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
-	if len(mounts) == 0 {
-		rootfs = ""
-	}
-
 	process, err := newInit(
 		ctx,
 		s.config.Path,