backup: test that deviceID is only stored for hardlinks

internal/archiver/archiver_unix_test.go

@@ -6,6 +6,12 @@ package archiver
 import (
 	"os"
 	"syscall"
+	"testing"
+
+	"github.com/restic/restic/internal/feature"
+	"github.com/restic/restic/internal/fs"
+	"github.com/restic/restic/internal/restic"
+	restictest "github.com/restic/restic/internal/test"
 )
 
 type wrappedFileInfo struct {
@@ -39,3 +45,45 @@ func wrapFileInfo(fi os.FileInfo) os.FileInfo {
 
 	return res
 }
+
+func statAndSnapshot(t *testing.T, repo restic.Repository, name string) (*restic.Node, *restic.Node) {
+	fi := lstat(t, name)
+	want, err := restic.NodeFromFileInfo(name, fi)
+	restictest.OK(t, err)
+
+	_, node := snapshot(t, repo, fs.Local{}, nil, name)
+	return want, node
+}
+
+func TestHardlinkMetadata(t *testing.T) {
+	defer feature.TestSetFlag(t, feature.Flag, feature.DeviceIDForHardlinks, true)()
+
+	files := TestDir{
+		"testfile": TestFile{
+			Content: "foo bar test file",
+		},
+		"linktarget": TestFile{
+			Content: "test file",
+		},
+		"testlink": TestHardlink{
+			Target: "./linktarget",
+		},
+		"testdir": TestDir{},
+	}
+
+	tempdir, repo := prepareTempdirRepoSrc(t, files)
+
+	back := restictest.Chdir(t, tempdir)
+	defer back()
+
+	want, node := statAndSnapshot(t, repo, "testlink")
+	restictest.Assert(t, node.DeviceID == want.DeviceID, "device id mismatch expected %v got %v", want.DeviceID, node.DeviceID)
+	restictest.Assert(t, node.Links == want.Links, "link count mismatch expected %v got %v", want.Links, node.Links)
+	restictest.Assert(t, node.Inode == want.Inode, "inode mismatch expected %v got %v", want.Inode, node.Inode)
+
+	_, node = statAndSnapshot(t, repo, "testfile")
+	restictest.Assert(t, node.DeviceID == 0, "device id mismatch for testfile expected %v got %v", 0, node.DeviceID)
+
+	_, node = statAndSnapshot(t, repo, "testdir")
+	restictest.Assert(t, node.DeviceID == 0, "device id mismatch for testdir expected %v got %v", 0, node.DeviceID)
+}

internal/archiver/testing.go

@@ -6,6 +6,7 @@ import (
 	"path"
 	"path/filepath"
 	"runtime"
+	"sort"
 	"strings"
 	"testing"
 	"time"
@@ -63,11 +64,29 @@ func (s TestSymlink) String() string {
 	return "<Symlink>"
 }
 
+// TestHardlink describes a hardlink created for a test.
+type TestHardlink struct {
+	Target string
+}
+
+func (s TestHardlink) String() string {
+	return "<Hardlink>"
+}
+
 // TestCreateFiles creates a directory structure described by dir at target,
 // which must already exist. On Windows, symlinks aren't created.
 func TestCreateFiles(t testing.TB, target string, dir TestDir) {
 	t.Helper()
-	for name, item := range dir {
+
+	// ensure a stable order such that it can be guaranteed that a hardlink target already exists
+	var names []string
+	for name := range dir {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+
+	for _, name := range names {
+		item := dir[name]
 		targetPath := filepath.Join(target, name)
 
 		switch it := item.(type) {
@@ -81,6 +100,11 @@ func TestCreateFiles(t testing.TB, target string, dir TestDir) {
 			if err != nil {
 				t.Fatal(err)
 			}
+		case TestHardlink:
+			err := fs.Link(filepath.Join(target, filepath.FromSlash(it.Target)), targetPath)
+			if err != nil {
+				t.Fatal(err)
+			}
 		case TestDir:
 			err := fs.Mkdir(targetPath, 0755)
 			if err != nil {