Function apply

core/diff/apply/apply_linux.go:34–73

(ctx context.Context, mounts []mount.Mount, r io.Reader, sync bool)

)

func apply(ctx context.Context, mounts []mount.Mount, r io.Reader, sync bool) (retErr error) {
	switch {
	case len(mounts) == 1 && mounts[0].Type == "overlay":
		// OverlayConvertWhiteout (mknod c 0 0) doesn't work in userns.
		// https://github.com/containerd/containerd/issues/3762
		if userns.RunningInUserNS() {
			break
		}
		path, parents, err := getOverlayPath(mounts[0].Options)
		if err != nil {
			if errdefs.IsInvalidArgument(err) {
				break
			}
			return err
		}
		opts := []archive.ApplyOpt{
			archive.WithConvertWhiteout(archive.OverlayConvertWhiteout),
		}
		if len(parents) > 0 {
			opts = append(opts, archive.WithParents(parents))
		}
		_, err = archive.Apply(ctx, path, r, opts...)
		if err == nil && sync {
			err = doSyncFs(path)
		}
		return err
	case sync && len(mounts) == 1 && mounts[0].Type == "bind":
		defer func() {
			if retErr != nil {
				return
			}

			retErr = doSyncFs(mounts[0].Source)
		}()
	}
	return mount.WithTempMount(ctx, mounts, func(root string) error {
		_, err := archive.Apply(ctx, root, r)
		return err
	})
}

func getOverlayPath(options []string) (upper string, lower []string, err error) {
	const upperdirPrefix = "upperdir="