Method RestoreSubcontainer

runsc/boot/controller.go:808–895

(args *StartArgs, _ *struct{})

}

func (cm *containerManager) RestoreSubcontainer(args *StartArgs, _ *struct{}) (retErr error) {
	log.Debugf("containerManager.RestoreSubcontainer, cid: %s, args: %+v", args.CID, args)
	cm.l.mu.Lock()
	state := cm.l.state
	cm.l.mu.Unlock()
	if state != restoringUnstarted {
		return fmt.Errorf("sandbox is not being restored, cannot restore subcontainer: state=%s", state)
	}
	defer func() {
		if retErr != nil {
			cm.onRestoreFailed(fmt.Errorf("RestoreSubcontainer failed: %w", retErr))
		}
	}()

	// Validate arguments.
	if args.Spec == nil {
		return errors.New("start arguments missing spec")
	}
	if args.Conf == nil {
		return errors.New("start arguments missing config")
	}
	if args.CID == "" {
		return errors.New("start argument missing container ID")
	}
	expectedFDs := 1 // At least one FD for the root filesystem.
	expectedFDs += args.NumGoferFilestoreFDs
	if args.IsDevIoFilePresent {
		expectedFDs++
	}
	if !args.Spec.Process.Terminal {
		expectedFDs += 3
	}
	if args.IsRootfsUpperTarFilePresent {
		return errors.New("rootfs upper tar file is not supported during restore")
	}
	if len(args.Files) < expectedFDs {
		return fmt.Errorf("restore arguments must contain at least %d FDs, but only got %d", expectedFDs, len(args.Files))
	}

	// All validation passed, logs the spec for debugging.
	specutils.LogSpecDebug(args.Spec, args.Conf.OCISeccomp)

	goferFiles := args.Files
	var stdios []*fd.FD
	if !args.Spec.Process.Terminal {
		// When not using a terminal, stdios come as the first 3 files in the
		// payload.
		var err error
		stdios, err = fd.NewFromFiles(goferFiles[:3])
		if err != nil {
			return fmt.Errorf("error dup'ing stdio files: %w", err)
		}
		goferFiles = goferFiles[3:]
	}

	var goferFilestoreFDs []*fd.FD
	for i := 0; i < args.NumGoferFilestoreFDs; i++ {
		overlayFilestoreFD, err := fd.NewFromFile(goferFiles[i])