Implement rename folder function in dir Inode interface (#2191)

* local changes

* add rename folder method in dir.go

* fix format

* add comment

* add new unit test

* small fix

* small fix

* compare with not found error

* trigger e2e tests

* review comment

internal/fs/inode/base_dir.go

@@ -242,3 +242,8 @@ func (d *baseDirInode) ShouldInvalidateKernelListCache(ttl time.Duration) bool {
 	// for baseDirInode.
 	return true
 }
+
+func (d *baseDirInode) RenameFolder(ctx context.Context, folderName string, destinationFolderId string) (op *gcs.Folder, err error) {
+	err = fuse.ENOSYS
+	return
+}

internal/fs/inode/dir.go

@@ -64,6 +64,9 @@ type DirInode interface {
 	// true.
 	LookUpChild(ctx context.Context, name string) (*Core, error)
 
+	// Rename the directiory/folder.
+	RenameFolder(ctx context.Context, folderName string, destinationFolderId string) (*gcs.Folder, error)
+
 	// Read the children objects of this dir, recursively. The result count
 	// is capped at the given limit. Internal caches are not refreshed from this
 	// call.
@@ -939,3 +942,18 @@ func (d *dirInode) ShouldInvalidateKernelListCache(ttl time.Duration) bool {
 	cachedDuration := d.cacheClock.Now().Sub(d.prevDirListingTimeStamp)
 	return cachedDuration >= ttl
 }
+
+func (d *dirInode) RenameFolder(ctx context.Context, folderName string, destinationFolderName string) (*gcs.Folder, error) {
+	folder, err := d.bucket.RenameFolder(ctx, folderName, destinationFolderName)
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: Cache updates won't be necessary once type cache usage is removed from HNS.
+	// Remove old entry from type cache.
+	d.cache.Erase(folderName)
+	// Add new renamed folder in type cache.
+	d.cache.Insert(d.cacheClock.Now(), destinationFolderName, metadata.ExplicitDirType)
+
+	return folder, nil
+}

internal/fs/inode/dir_test.go

@@ -1565,3 +1565,46 @@ func (t *DirTest) TestShouldReturnNilWhenGCSFolderNotFound() {
 	AssertEq(nil, err)
 	AssertEq(nil, result)
 }
+
+func (t *DirTest) TestRenameFolderWithGivenName() {
+	const (
+		dirName       = "qux"
+		renameDirName = "rename"
+	)
+	folderName := path.Join(dirInodeName, dirName) + "/"
+	renameFolderName := path.Join(dirInodeName, renameDirName) + "/"
+	// Create the original folder.
+	_, err := t.bucket.CreateFolder(t.ctx, folderName)
+	AssertEq(nil, err)
+
+	// Attempt to rename the folder.
+	f, err := t.in.RenameFolder(t.ctx, folderName, renameFolderName)
+
+	AssertEq(nil, err)
+	// Verify the original folder no longer exists.
+	_, err = t.bucket.GetFolder(t.ctx, folderName)
+	var notFoundErr *gcs.NotFoundError
+	ExpectTrue(errors.As(err, &notFoundErr))
+	// Verify the renamed folder exists.
+	_, err = t.bucket.GetFolder(t.ctx, renameFolderName)
+	AssertEq(nil, err)
+	AssertEq(renameFolderName, f.Name)
+}
+
+func (t *DirTest) TestRenameFolderWithNonExistentSourceFolder() {
+	const (
+		dirName       = "qux"
+		renameDirName = "rename"
+	)
+	folderName := path.Join(dirInodeName, dirName) + "/"
+	renameFolderName := path.Join(dirInodeName, renameDirName) + "/"
+
+	// Attempt to rename the folder.
+	_, err := t.in.RenameFolder(t.ctx, folderName, renameFolderName)
+
+	var notFoundErr *gcs.NotFoundError
+	ExpectTrue(errors.As(err, &notFoundErr))
+	// Verify the renamed folder does not exist.
+	_, err = t.bucket.GetFolder(t.ctx, renameFolderName)
+	ExpectTrue(errors.As(err, &notFoundErr))
+}

internal/storage/fake/bucket.go

@@ -25,6 +25,7 @@ import (
 	"io"
 	"sort"
 	"strings"
+	"time"
 	"unicode/utf8"
 
 	"github.com/googlecloudplatform/gcsfuse/v2/internal/storage/gcs"
@@ -976,11 +977,11 @@ func (b *bucket) CreateFolder(ctx context.Context, folderName string) (*gcs.Fold
 	return &fo, nil
 }
 
-func (b *bucket) RenameFolder(ctx context.Context, folderName string, destinationFolderId string) (o *gcs.Folder, err error) {
+func (b *bucket) RenameFolder(ctx context.Context, folderName string, destinationFolderId string) (*gcs.Folder, error) {
 	// Check that the destination name is legal.
-	err = checkName(destinationFolderId)
+	err := checkName(destinationFolderId)
 	if err != nil {
-		return
+		return nil, err
 	}
 
 	// Does the folder exist?
@@ -989,7 +990,7 @@ func (b *bucket) RenameFolder(ctx context.Context, folderName string, destinatio
 		err = &gcs.NotFoundError{
 			Err: fmt.Errorf("Object %q not found", folderName),
 		}
-		return
+		return nil, err
 	}
 
 	dst := b.folders[srcIndex]
@@ -1004,14 +1005,18 @@ func (b *bucket) RenameFolder(ctx context.Context, folderName string, destinatio
 		sort.Sort(b.folders)
 	}
 
+	folder := &gcs.Folder{
+		Name:           destinationFolderId,
+		MetaGeneration: 1,
+		UpdateTime:     time.Now()}
+
 	// Delete the src folder?
 	index := b.folders.find(folderName)
 	if index == len(b.folders) {
-		return
+		return folder, nil
 	}
-
-	// Remove the folder.
+	// Remove the src folder?
 	b.folders = append(b.folders[:index], b.folders[index+1:]...)
 
-	return
+	return folder, nil
 }