fs: remove os.FileInfo from fs.ExtendedFileInfo

Only the `Sys()` value from os.FileInfo is kept as field `sys` to
support Windows. The os.FileInfo removal ensures that for values like
`ModTime` that existed in both data structures there's no more confusion
which value is actually used.

internal/fs/fs_local_test.go

@@ -84,7 +84,7 @@ func checkMetadata(t *testing.T, f File, path string, follow bool, nodeType rest
 		fi2, err = os.Lstat(path)
 	}
 	rtest.OK(t, err)
-	assertFIEqual(t, fi2, fi.FileInfo)
+	assertFIEqual(t, fi2, fi)
 
 	node, err := f.ToNode(false)
 	rtest.OK(t, err)
@@ -94,13 +94,12 @@ func checkMetadata(t *testing.T, f File, path string, follow bool, nodeType rest
 	rtest.Equals(t, nodeType, node.Type, "node Type")
 }
 
-func assertFIEqual(t *testing.T, want os.FileInfo, got os.FileInfo) {
+func assertFIEqual(t *testing.T, want os.FileInfo, got *ExtendedFileInfo) {
 	t.Helper()
-	rtest.Equals(t, want.Name(), got.Name(), "Name")
-	rtest.Equals(t, want.IsDir(), got.IsDir(), "IsDir")
-	rtest.Equals(t, want.ModTime(), got.ModTime(), "ModTime")
-	rtest.Equals(t, want.Mode(), got.Mode(), "Mode")
-	rtest.Equals(t, want.Size(), got.Size(), "Size")
+	rtest.Equals(t, want.Name(), got.Name, "Name")
+	rtest.Equals(t, want.ModTime(), got.ModTime, "ModTime")
+	rtest.Equals(t, want.Mode(), got.Mode, "Mode")
+	rtest.Equals(t, want.Size(), got.Size, "Size")
 }
 
 func TestFSLocalRead(t *testing.T) {
@@ -206,7 +205,7 @@ func TestFSLocalTypeChange(t *testing.T) {
 
 	fi, err := f.Stat()
 	rtest.OK(t, err)
-	if !fi.IsDir() {
+	if !fi.Mode.IsDir() {
 		// a file handle based implementation should still reference the file
 		checkMetadata(t, f, pathNew, false, restic.NodeTypeFile)
 

internal/fs/fs_local_vss_test.go

@@ -325,7 +325,7 @@ func TestVSSFS(t *testing.T) {
 
 	lstatFi, err := localVss.Lstat(tempfile)
 	rtest.OK(t, err)
-	rtest.Equals(t, origFi.Mode(), lstatFi.Mode())
+	rtest.Equals(t, origFi.Mode, lstatFi.Mode)
 
 	f, err := localVss.OpenFile(tempfile, os.O_RDONLY, false)
 	rtest.OK(t, err)
@@ -335,7 +335,7 @@ func TestVSSFS(t *testing.T) {
 
 	node, err := f.ToNode(false)
 	rtest.OK(t, err)
-	rtest.Equals(t, node.Mode, lstatFi.Mode())
+	rtest.Equals(t, node.Mode, lstatFi.Mode)
 
 	rtest.OK(t, f.Close())
 }

internal/fs/fs_reader.go

@@ -43,12 +43,10 @@ func (fs *Reader) VolumeName(_ string) string {
 
 func (fs *Reader) fi() *ExtendedFileInfo {
 	return &ExtendedFileInfo{
-		FileInfo: fakeFileInfo{
-			name:    fs.Name,
-			size:    fs.Size,
-			mode:    fs.Mode,
-			modtime: fs.ModTime,
-		},
+		Name:    fs.Name,
+		Mode:    fs.Mode,
+		ModTime: fs.ModTime,
+		Size:    fs.Size,
 	}
 }
 
@@ -71,7 +69,7 @@ func (fs *Reader) OpenFile(name string, flag int, _ bool) (f File, err error) {
 		return f, nil
 	case "/", ".":
 		f = fakeDir{
-			entries: []string{fs.fi().Name()},
+			entries: []string{fs.fi().Name},
 		}
 		return f, nil
 	}
@@ -85,13 +83,12 @@ func (fs *Reader) OpenFile(name string, flag int, _ bool) (f File, err error) {
 // If there is an error, it will be of type *os.PathError.
 func (fs *Reader) Lstat(name string) (*ExtendedFileInfo, error) {
 	getDirInfo := func(name string) *ExtendedFileInfo {
-		fi := fakeFileInfo{
-			name:    fs.Base(name),
-			size:    0,
-			mode:    os.ModeDir | 0755,
-			modtime: time.Now(),
+		return &ExtendedFileInfo{
+			Name:    fs.Base(name),
+			Size:    0,
+			Mode:    os.ModeDir | 0755,
+			ModTime: time.Now(),
 		}
-		return &ExtendedFileInfo{FileInfo: fi}
 	}
 
 	switch name {
@@ -164,7 +161,7 @@ func newReaderFile(rd io.ReadCloser, fi *ExtendedFileInfo, allowEmptyFile bool)
 		AllowEmptyFile: allowEmptyFile,
 		fakeFile: fakeFile{
 			fi:   fi,
-			name: fi.Name(),
+			name: fi.Name,
 		},
 	}
 }
@@ -233,7 +230,7 @@ func (f fakeFile) Stat() (*ExtendedFileInfo, error) {
 }
 
 func (f fakeFile) ToNode(_ bool) (*restic.Node, error) {
-	node := buildBasicNode(f.name, f.fi.FileInfo)
+	node := buildBasicNode(f.name, f.fi)
 
 	// fill minimal info with current values for uid, gid
 	node.UID = uint32(os.Getuid())
@@ -256,38 +253,6 @@ func (d fakeDir) Readdirnames(n int) ([]string, error) {
 	return slices.Clone(d.entries), nil
 }
 
-// fakeFileInfo implements the bare minimum of os.FileInfo.
-type fakeFileInfo struct {
-	name    string
-	size    int64
-	mode    os.FileMode
-	modtime time.Time
-}
-
-func (fi fakeFileInfo) Name() string {
-	return fi.name
-}
-
-func (fi fakeFileInfo) Size() int64 {
-	return fi.size
-}
-
-func (fi fakeFileInfo) Mode() os.FileMode {
-	return fi.mode
-}
-
-func (fi fakeFileInfo) ModTime() time.Time {
-	return fi.modtime
-}
-
-func (fi fakeFileInfo) IsDir() bool {
-	return fi.mode&os.ModeDir > 0
-}
-
-func (fi fakeFileInfo) Sys() interface{} {
-	return nil
-}
-
 func pathError(op, name string, err error) *os.PathError {
 	return &os.PathError{Op: op, Path: name, Err: err}
 }

internal/fs/fs_reader_test.go

@@ -61,24 +61,24 @@ func verifyDirectoryContents(t testing.TB, fs FS, dir string, want []string) {
 }
 
 func checkFileInfo(t testing.TB, fi *ExtendedFileInfo, filename string, modtime time.Time, mode os.FileMode, isdir bool) {
-	if fi.IsDir() != isdir {
-		t.Errorf("IsDir returned %t, want %t", fi.IsDir(), isdir)
+	if fi.Mode.IsDir() != isdir {
+		t.Errorf("IsDir returned %t, want %t", fi.Mode.IsDir(), isdir)
 	}
 
-	if fi.Mode() != mode {
-		t.Errorf("Mode() returned wrong value, want 0%o, got 0%o", mode, fi.Mode())
+	if fi.Mode != mode {
+		t.Errorf("Mode has wrong value, want 0%o, got 0%o", mode, fi.Mode)
 	}
 
-	if !modtime.Equal(time.Time{}) && !fi.FileInfo.ModTime().Equal(modtime) {
-		t.Errorf("ModTime() returned wrong value, want %v, got %v", modtime, fi.FileInfo.ModTime())
+	if !modtime.Equal(time.Time{}) && !fi.ModTime.Equal(modtime) {
+		t.Errorf("ModTime has wrong value, want %v, got %v", modtime, fi.ModTime)
 	}
 
-	if path.Base(fi.Name()) != fi.Name() {
-		t.Errorf("Name() returned is not base, want %q, got %q", path.Base(fi.Name()), fi.Name())
+	if path.Base(fi.Name) != fi.Name {
+		t.Errorf("Name is not base, want %q, got %q", path.Base(fi.Name), fi.Name)
 	}
 
-	if fi.Name() != path.Base(filename) {
-		t.Errorf("Name() returned wrong value, want %q, got %q", path.Base(filename), fi.Name())
+	if fi.Name != path.Base(filename) {
+		t.Errorf("Name has wrong value, want %q, got %q", path.Base(filename), fi.Name)
 	}
 }
 

internal/fs/node.go

@@ -16,7 +16,7 @@ import (
 // nodeFromFileInfo returns a new node from the given path and FileInfo. It
 // returns the first error that is encountered, together with a node.
 func nodeFromFileInfo(path string, fi *ExtendedFileInfo, ignoreXattrListError bool) (*restic.Node, error) {
-	node := buildBasicNode(path, fi.FileInfo)
+	node := buildBasicNode(path, fi)
 
 	if err := nodeFillExtendedStat(node, path, fi); err != nil {
 		return node, err
@@ -27,18 +27,18 @@ func nodeFromFileInfo(path string, fi *ExtendedFileInfo, ignoreXattrListError bo
 	return node, err
 }
 
-func buildBasicNode(path string, fi os.FileInfo) *restic.Node {
+func buildBasicNode(path string, fi *ExtendedFileInfo) *restic.Node {
 	mask := os.ModePerm | os.ModeType | os.ModeSetuid | os.ModeSetgid | os.ModeSticky
 	node := &restic.Node{
 		Path:    path,
-		Name:    fi.Name(),
-		Mode:    fi.Mode() & mask,
-		ModTime: fi.ModTime(),
+		Name:    fi.Name,
+		Mode:    fi.Mode & mask,
+		ModTime: fi.ModTime,
 	}
 
-	node.Type = nodeTypeFromFileInfo(fi.Mode())
+	node.Type = nodeTypeFromFileInfo(fi.Mode)
 	if node.Type == restic.NodeTypeFile {
-		node.Size = uint64(fi.Size())
+		node.Size = uint64(fi.Size)
 	}
 	return node
 }

internal/fs/node_windows.go

@@ -361,7 +361,7 @@ func nodeFillGenericAttributes(node *restic.Node, path string, stat *ExtendedFil
 		}
 	}
 
-	winFI := stat.Sys().(*syscall.Win32FileAttributeData)
+	winFI := stat.sys.(*syscall.Win32FileAttributeData)
 
 	// Add Windows attributes
 	node.GenericAttributes, err = restic.WindowsAttrsToGenericAttributes(restic.WindowsAttributes{

internal/fs/stat.go

@@ -8,7 +8,8 @@ import (
 // ExtendedFileInfo is an extended stat_t, filled with attributes that are
 // supported by most operating systems. The original FileInfo is embedded.
 type ExtendedFileInfo struct {
-	os.FileInfo
+	Name string
+	Mode os.FileMode
 
 	DeviceID  uint64 // ID of device containing the file
 	Inode     uint64 // Inode number
@@ -23,6 +24,9 @@ type ExtendedFileInfo struct {
 	AccessTime time.Time // last access time stamp
 	ModTime    time.Time // last (content) modification time stamp
 	ChangeTime time.Time // last status change time stamp
+
+	// nolint:unused // only used on Windows
+	sys any // Value returned by os.FileInfo.Sys()
 }
 
 // ExtendedStat returns an ExtendedFileInfo constructed from the os.FileInfo.

internal/fs/stat_bsd.go

@@ -14,7 +14,9 @@ func extendedStat(fi os.FileInfo) *ExtendedFileInfo {
 	s := fi.Sys().(*syscall.Stat_t)
 
 	return &ExtendedFileInfo{
-		FileInfo:  fi,
+		Name: fi.Name(),
+		Mode: fi.Mode(),
+
 		DeviceID:  uint64(s.Dev),
 		Inode:     uint64(s.Ino),
 		Links:     uint64(s.Nlink),

internal/fs/stat_unix.go

@@ -14,7 +14,9 @@ func extendedStat(fi os.FileInfo) *ExtendedFileInfo {
 	s := fi.Sys().(*syscall.Stat_t)
 
 	return &ExtendedFileInfo{
-		FileInfo:  fi,
+		Name: fi.Name(),
+		Mode: fi.Mode(),
+
 		DeviceID:  uint64(s.Dev),
 		Inode:     s.Ino,
 		Links:     uint64(s.Nlink),

internal/fs/stat_windows.go

@@ -18,8 +18,11 @@ func extendedStat(fi os.FileInfo) *ExtendedFileInfo {
 	}
 
 	extFI := ExtendedFileInfo{
-		FileInfo: fi,
-		Size:     int64(s.FileSizeLow) | (int64(s.FileSizeHigh) << 32),
+		Name: fi.Name(),
+		Mode: fi.Mode(),
+
+		Size: int64(s.FileSizeLow) | (int64(s.FileSizeHigh) << 32),
+		sys:  fi.Sys(),
 	}
 
 	atime := syscall.NsecToTimespec(s.LastAccessTime.Nanoseconds())