newunionfs: implement Readdir

newunionfs/unionfs.go

@@ -37,6 +37,29 @@ type unionFSNode struct {
 
 const delDir = "DELETIONS"
 
+func (r *unionFSRoot) allMarkers(result map[string]struct{}) syscall.Errno {
+	dir := filepath.Join(r.roots[0], delDir)
+
+	ds, errno := nodefs.NewLoopbackDirStream(dir)
+	if errno != 0 {
+		return errno
+	}
+
+	defer ds.Close()
+	for ds.HasNext() {
+		e, errno := ds.Next()
+		if errno != 0 {
+			return errno
+		}
+		if e.Mode != syscall.S_IFREG {
+			continue
+		}
+		result[e.Name] = struct{}{}
+	}
+
+	return 0
+}
+
 func (r *unionFSRoot) rmMarker(name string) syscall.Errno {
 	err := syscall.Unlink(r.markerPath(name))
 	if err != nil {
@@ -297,6 +320,54 @@ func (n *unionFSNode) Readlink(ctx context.Context) ([]byte, syscall.Errno) {
 	return buf[:count], 0
 }
 
+var _ = (nodefs.Readdirer)((*unionFSNode)(nil))
+
+func (n *unionFSNode) Readdir(ctx context.Context) (nodefs.DirStream, syscall.Errno) {
+	root := n.root()
+
+	markers := map[string]struct{}{}
+	// ignore error: assume no markers
+	root.allMarkers(markers)
+
+	dir := n.Path(nil)
+
+	names := map[string]uint32{}
+	for i := range root.roots {
+		// deepest root first.
+		readRoot(root.roots[len(root.roots)-i-1], dir, names)
+	}
+
+	result := make([]fuse.DirEntry, 0, len(names))
+	for nm, mode := range names {
+		marker := filePathHash(filepath.Join(dir, nm))
+		if _, ok := markers[marker]; ok {
+			continue
+		}
+		result = append(result, fuse.DirEntry{
+			Name: nm,
+			Mode: mode,
+		})
+	}
+
+	return nodefs.NewListDirStream(result), 0
+}
+
+func readRoot(root string, dir string, result map[string]uint32) {
+	ds, errno := nodefs.NewLoopbackDirStream(filepath.Join(root, dir))
+	if errno != 0 {
+		return
+	}
+	defer ds.Close()
+	for ds.HasNext() {
+		e, errno := ds.Next()
+		if errno != 0 {
+			return
+		}
+
+		result[e.Name] = e.Mode
+	}
+}
+
 // getBranch returns the root where we can find the given file. It
 // will check the deletion markers in roots[0].
 func (n *unionFSNode) getBranch(st *syscall.Stat_t) (string, int) {

newunionfs/unionfs_test.go

@@ -9,6 +9,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"reflect"
 	"syscall"
 	"testing"
 
@@ -196,6 +197,41 @@ func TestDeleteRevert(t *testing.T) {
 	}
 }
 
+func TestReaddir(t *testing.T) {
+	tc := newTestCase(t, true)
+	defer tc.Clean()
+
+	if err := ioutil.WriteFile(tc.ro+"/dir/file2", nil, 0644); err != nil {
+		t.Fatalf("WriteFile: %v", err)
+	}
+	if err := os.Mkdir(tc.rw+"/dir", 0755); err != nil {
+		t.Fatalf("Mkdir: %v", err)
+	}
+	if err := ioutil.WriteFile(tc.rw+"/dir/file3", nil, 0644); err != nil {
+		t.Fatalf("WriteFile: %v", err)
+	}
+	if err := os.Remove(tc.mnt + "/dir/ro-file"); err != nil {
+		t.Fatalf("Remove: %v", err)
+	}
+
+	res, err := ioutil.ReadDir(tc.mnt + "/dir")
+	if err != nil {
+		t.Fatalf("ReadDir: %v", err)
+	}
+
+	got := map[string]bool{}
+	want := map[string]bool{
+		"file2": true,
+		"file3": true,
+	}
+	for _, fi := range res {
+		got[fi.Name()] = true
+	}
+	if !reflect.DeepEqual(want, got) {
+		t.Errorf("got %v want %v", got, want)
+	}
+}
+
 func TestPosix(t *testing.T) {
 	cases := []string{
 		"SymlinkReadlink",
@@ -207,7 +243,7 @@ func TestPosix(t *testing.T) {
 		//		"NlinkZero",
 		"ParallelFileOpen",
 		//		"Link",
-		//		"ReadDir",
+		"ReadDir",
 	}
 
 	for _, nm := range cases {