diff --git a/internal/archiver/archiver.go b/internal/archiver/archiver.go
index 2597e4143..5a3fec108 100644
--- a/internal/archiver/archiver.go
+++ b/internal/archiver/archiver.go
@@ -216,10 +216,11 @@ func (arch *Archiver) SaveDir(ctx context.Context, snPath string, fi os.FileInfo
 		return FutureTree{}, err
 	}
 
-	names, err := readdirnames(arch.FS, dir)
+	names, err := readdirnames(arch.FS, dir, fs.O_NOFOLLOW)
 	if err != nil {
 		return FutureTree{}, err
 	}
+	sort.Strings(names)
 
 	nodes := make([]FutureNode, 0, len(names))
 
@@ -628,43 +629,9 @@ func (arch *Archiver) SaveTree(ctx context.Context, snPath string, atree *Tree,
 	return tree, nil
 }
 
-type fileInfoSlice []os.FileInfo
-
-func (fi fileInfoSlice) Len() int {
-	return len(fi)
-}
-
-func (fi fileInfoSlice) Swap(i, j int) {
-	fi[i], fi[j] = fi[j], fi[i]
-}
-
-func (fi fileInfoSlice) Less(i, j int) bool {
-	return fi[i].Name() < fi[j].Name()
-}
-
-func readdir(filesystem fs.FS, dir string) ([]os.FileInfo, error) {
-	f, err := filesystem.OpenFile(dir, fs.O_RDONLY|fs.O_NOFOLLOW, 0)
-	if err != nil {
-		return nil, errors.Wrap(err, "Open")
-	}
-
-	entries, err := f.Readdir(-1)
-	if err != nil {
-		_ = f.Close()
-		return nil, errors.Wrapf(err, "Readdir %v failed", dir)
-	}
-
-	err = f.Close()
-	if err != nil {
-		return nil, err
-	}
-
-	sort.Sort(fileInfoSlice(entries))
-	return entries, nil
-}
-
-func readdirnames(filesystem fs.FS, dir string) ([]string, error) {
-	f, err := filesystem.OpenFile(dir, fs.O_RDONLY|fs.O_NOFOLLOW, 0)
+// flags are passed to fs.OpenFile. O_RDONLY is implied.
+func readdirnames(filesystem fs.FS, dir string, flags int) ([]string, error) {
+	f, err := filesystem.OpenFile(dir, fs.O_RDONLY|flags, 0)
 	if err != nil {
 		return nil, errors.Wrap(err, "Open")
 	}
@@ -680,32 +647,32 @@ func readdirnames(filesystem fs.FS, dir string) ([]string, error) {
 		return nil, err
 	}
 
-	sort.Sort(sort.StringSlice(entries))
 	return entries, nil
 }
 
 // resolveRelativeTargets replaces targets that only contain relative
 // directories ("." or "../../") with the contents of the directory. Each
 // element of target is processed with fs.Clean().
-func resolveRelativeTargets(fs fs.FS, targets []string) ([]string, error) {
+func resolveRelativeTargets(filesys fs.FS, targets []string) ([]string, error) {
 	debug.Log("targets before resolving: %v", targets)
 	result := make([]string, 0, len(targets))
 	for _, target := range targets {
-		target = fs.Clean(target)
-		pc, _ := pathComponents(fs, target, false)
+		target = filesys.Clean(target)
+		pc, _ := pathComponents(filesys, target, false)
 		if len(pc) > 0 {
 			result = append(result, target)
 			continue
 		}
 
 		debug.Log("replacing %q with readdir(%q)", target, target)
-		entries, err := readdirnames(fs, target)
+		entries, err := readdirnames(filesys, target, fs.O_NOFOLLOW)
 		if err != nil {
 			return nil, err
 		}
+		sort.Strings(entries)
 
 		for _, name := range entries {
-			result = append(result, fs.Join(target, name))
+			result = append(result, filesys.Join(target, name))
 		}
 	}
 
@@ -754,7 +721,6 @@ func (arch *Archiver) runWorkers(ctx context.Context, t *tomb.Tomb) {
 	arch.blobSaver = NewBlobSaver(ctx, t, arch.Repo, arch.Options.SaveBlobConcurrency)
 
 	arch.fileSaver = NewFileSaver(ctx, t,
-		arch.FS,
 		arch.blobSaver.Save,
 		arch.Repo.Config().ChunkerPolynomial,
 		arch.Options.FileReadConcurrency, arch.Options.SaveBlobConcurrency)
diff --git a/internal/archiver/file_saver.go b/internal/archiver/file_saver.go
index 66defe358..c958e4e19 100644
--- a/internal/archiver/file_saver.go
+++ b/internal/archiver/file_saver.go
@@ -53,7 +53,6 @@ type SaveBlobFn func(context.Context, restic.BlobType, *Buffer) FutureBlob
 
 // FileSaver concurrently saves incoming files to the repo.
 type FileSaver struct {
-	fs           fs.FS
 	saveFilePool *BufferPool
 	saveBlob     SaveBlobFn
 
@@ -69,7 +68,7 @@ type FileSaver struct {
 
 // NewFileSaver returns a new file saver. A worker pool with fileWorkers is
 // started, it is stopped when ctx is cancelled.
-func NewFileSaver(ctx context.Context, t *tomb.Tomb, fs fs.FS, save SaveBlobFn, pol chunker.Pol, fileWorkers, blobWorkers uint) *FileSaver {
+func NewFileSaver(ctx context.Context, t *tomb.Tomb, save SaveBlobFn, pol chunker.Pol, fileWorkers, blobWorkers uint) *FileSaver {
 	ch := make(chan saveFileJob)
 
 	debug.Log("new file saver with %v file workers and %v blob workers", fileWorkers, blobWorkers)
@@ -77,7 +76,6 @@ func NewFileSaver(ctx context.Context, t *tomb.Tomb, fs fs.FS, save SaveBlobFn,
 	poolSize := fileWorkers + blobWorkers
 
 	s := &FileSaver{
-		fs:           fs,
 		saveBlob:     save,
 		saveFilePool: NewBufferPool(ctx, int(poolSize), chunker.MaxSize),
 		pol:          pol,
diff --git a/internal/archiver/file_saver_test.go b/internal/archiver/file_saver_test.go
index c8cf58735..88e62fd57 100644
--- a/internal/archiver/file_saver_test.go
+++ b/internal/archiver/file_saver_test.go
@@ -30,7 +30,7 @@ func createTestFiles(t testing.TB, num int) (files []string, cleanup func()) {
 	return files, cleanup
 }
 
-func startFileSaver(ctx context.Context, t testing.TB, fs fs.FS) (*FileSaver, *tomb.Tomb) {
+func startFileSaver(ctx context.Context, t testing.TB) (*FileSaver, *tomb.Tomb) {
 	var tmb tomb.Tomb
 
 	saveBlob := func(ctx context.Context, tpe restic.BlobType, buf *Buffer) FutureBlob {
@@ -45,7 +45,7 @@ func startFileSaver(ctx context.Context, t testing.TB, fs fs.FS) (*FileSaver, *t
 		t.Fatal(err)
 	}
 
-	s := NewFileSaver(ctx, &tmb, fs, saveBlob, pol, workers, workers)
+	s := NewFileSaver(ctx, &tmb, saveBlob, pol, workers, workers)
 	s.NodeFromFileInfo = restic.NodeFromFileInfo
 
 	return s, &tmb
@@ -62,7 +62,7 @@ func TestFileSaver(t *testing.T) {
 	completeFn := func(*restic.Node, ItemStats) {}
 
 	testFs := fs.Local{}
-	s, tmb := startFileSaver(ctx, t, testFs)
+	s, tmb := startFileSaver(ctx, t)
 
 	var results []FutureFile
 
diff --git a/internal/archiver/scanner.go b/internal/archiver/scanner.go
index bd789893c..71634015b 100644
--- a/internal/archiver/scanner.go
+++ b/internal/archiver/scanner.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"os"
 	"path/filepath"
+	"sort"
 
 	"github.com/restic/restic/internal/fs"
 )
@@ -86,10 +87,11 @@ func (s *Scanner) scan(ctx context.Context, stats ScanStats, target string) (Sca
 		stats.Files++
 		stats.Bytes += uint64(fi.Size())
 	case fi.Mode().IsDir():
-		names, err := readdirnames(s.FS, target)
+		names, err := readdirnames(s.FS, target, fs.O_NOFOLLOW)
 		if err != nil {
 			return stats, s.Error(target, fi, err)
 		}
+		sort.Strings(names)
 
 		for _, name := range names {
 			stats, err = s.scan(ctx, stats, filepath.Join(target, name))
diff --git a/internal/archiver/tree.go b/internal/archiver/tree.go
index 0c8a21539..04c0a8e33 100644
--- a/internal/archiver/tree.go
+++ b/internal/archiver/tree.go
@@ -214,7 +214,7 @@ func unrollTree(f fs.FS, t *Tree) error {
 	// nodes, add the contents of Path to the nodes.
 	if t.Path != "" && len(t.Nodes) > 0 {
 		debug.Log("resolve path %v", t.Path)
-		entries, err := fs.ReadDirNames(f, t.Path)
+		entries, err := readdirnames(f, t.Path, 0)
 		if err != nil {
 			return err
 		}
diff --git a/internal/archiver/tree_test.go b/internal/archiver/tree_test.go
index 5d460bb37..00d0b6b82 100644
--- a/internal/archiver/tree_test.go
+++ b/internal/archiver/tree_test.go
@@ -1,6 +1,7 @@
 package archiver
 
 import (
+	"fmt"
 	"path/filepath"
 	"runtime"
 	"testing"
@@ -10,6 +11,9 @@ import (
 	restictest "github.com/restic/restic/internal/test"
 )
 
+// debug.Log requires Tree.String.
+var _ fmt.Stringer = Tree{}
+
 func TestPathComponents(t *testing.T) {
 	var tests = []struct {
 		p       string
diff --git a/internal/fs/fs_helpers.go b/internal/fs/fs_helpers.go
deleted file mode 100644
index 6b269f763..000000000
--- a/internal/fs/fs_helpers.go
+++ /dev/null
@@ -1,45 +0,0 @@
-package fs
-
-import "os"
-
-// ReadDir reads the directory named by dirname within fs and returns a list of
-// directory entries.
-func ReadDir(fs FS, dirname string) ([]os.FileInfo, error) {
-	f, err := fs.Open(dirname)
-	if err != nil {
-		return nil, err
-	}
-
-	entries, err := f.Readdir(-1)
-	if err != nil {
-		return nil, err
-	}
-
-	err = f.Close()
-	if err != nil {
-		return nil, err
-	}
-
-	return entries, nil
-}
-
-// ReadDirNames reads the directory named by dirname within fs and returns a
-// list of entry names.
-func ReadDirNames(fs FS, dirname string) ([]string, error) {
-	f, err := fs.Open(dirname)
-	if err != nil {
-		return nil, err
-	}
-
-	entries, err := f.Readdirnames(-1)
-	if err != nil {
-		return nil, err
-	}
-
-	err = f.Close()
-	if err != nil {
-		return nil, err
-	}
-
-	return entries, nil
-}