Repository: restic/restic (go)

Issue:
Inform about downloading index
When using restic on a "slow" connection, it takes a while to download the index form the remote repository, and during this time restic just sits there without saying anything, leaving the user in the dark unless they check and see that there is much active network traffic.

It would be nice if restic at least notified the user that it's working on downloading the index, and even better output a progress/percentage during that time to keep the user updated. Something along the lines of `Downloading index... 42%`.


Pull request:
Progress Bar when loading index files
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What does this PR change? What problem does it solve?
-----------------------------------------------------

Restic did not provide any feedback while loading index files. Now there is a progress bar for the index loading process.

Was the change previously discussed in an issue or on the forum?
----------------------------------------------------------------

Closes #229 

Checklist
---------

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Patch:
diff --git a/changelog/unreleased/pull-299 b/changelog/unreleased/pull-299
new file mode 100644
index 000000000..aae5c0e05
--- /dev/null
+++ b/changelog/unreleased/pull-299
@@ -0,0 +1,6 @@
+Enhancement: Show progress bar while loading the index
+
+Restic did not provide any feedback while loading index files. Now there is a progress bar for the index loading process. 
+
+https://github.com/restic/restic/issues/229
+https://github.com/restic/restic/pull/4419
diff --git a/cmd/restic/cmd_backup.go b/cmd/restic/cmd_backup.go
index 6b5706855..e476ae7b8 100644
--- a/cmd/restic/cmd_backup.go
+++ b/cmd/restic/cmd_backup.go
@@ -546,7 +546,10 @@ func runBackup(ctx context.Context, opts BackupOptions, gopts GlobalOptions, ter
 	if !gopts.JSON {
 		progressPrinter.V("load index files")
 	}
-	err = repo.LoadIndex(ctx)
+
+	bar := newIndexTerminalProgress(gopts.Quiet, gopts.JSON, term)
+
+	err = repo.LoadIndex(ctx, bar)
 	if err != nil {
 		return err
 	}
diff --git a/cmd/restic/cmd_cat.go b/cmd/restic/cmd_cat.go
index 97789d271..238614cd0 100644
--- a/cmd/restic/cmd_cat.go
+++ b/cmd/restic/cmd_cat.go
@@ -169,7 +169,8 @@ func runCat(ctx context.Context, gopts GlobalOptions, args []string) error {
 		return err
 
 	case "blob":
-		err = repo.LoadIndex(ctx)
+		bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+		err = repo.LoadIndex(ctx, bar)
 		if err != nil {
 			return err
 		}
@@ -197,7 +198,8 @@ func runCat(ctx context.Context, gopts GlobalOptions, args []string) error {
 			return errors.Fatalf("could not find snapshot: %v\n", err)
 		}
 
-		err = repo.LoadIndex(ctx)
+		bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+		err = repo.LoadIndex(ctx, bar)
 		if err != nil {
 			return err
 		}
diff --git a/cmd/restic/cmd_check.go b/cmd/restic/cmd_check.go
index 3c4c9daa9..5f03c446b 100644
--- a/cmd/restic/cmd_check.go
+++ b/cmd/restic/cmd_check.go
@@ -226,7 +226,8 @@ func runCheck(ctx context.Context, opts CheckOptions, gopts GlobalOptions, args
 	}
 
 	Verbosef("load indexes\n")
-	hints, errs := chkr.LoadIndex(ctx)
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	hints, errs := chkr.LoadIndex(ctx, bar)
 
 	errorsFound := false
 	suggestIndexRebuild := false
diff --git a/cmd/restic/cmd_copy.go b/cmd/restic/cmd_copy.go
index eaa0ef81a..f31c17adb 100644
--- a/cmd/restic/cmd_copy.go
+++ b/cmd/restic/cmd_copy.go
@@ -99,12 +99,13 @@ func runCopy(ctx context.Context, opts CopyOptions, gopts GlobalOptions, args []
 	}
 
 	debug.Log("Loading source index")
-	if err := srcRepo.LoadIndex(ctx); err != nil {
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	if err := srcRepo.LoadIndex(ctx, bar); err != nil {
 		return err
 	}
-
+	bar = newIndexProgress(gopts.Quiet, gopts.JSON)
 	debug.Log("Loading destination index")
-	if err := dstRepo.LoadIndex(ctx); err != nil {
+	if err := dstRepo.LoadIndex(ctx, bar); err != nil {
 		return err
 	}
 
diff --git a/cmd/restic/cmd_debug.go b/cmd/restic/cmd_debug.go
index a54200c45..bf05c448d 100644
--- a/cmd/restic/cmd_debug.go
+++ b/cmd/restic/cmd_debug.go
@@ -134,7 +134,7 @@ func printPacks(ctx context.Context, repo *repository.Repository, wr io.Writer)
 }
 
 func dumpIndexes(ctx context.Context, repo restic.Repository, wr io.Writer) error {
-	return index.ForAllIndexes(ctx, repo, func(id restic.ID, idx *index.Index, oldFormat bool, err error) error {
+	return index.ForAllIndexes(ctx, repo.Backend(), repo, func(id restic.ID, idx *index.Index, oldFormat bool, err error) error {
 		Printf("index_id: %v\n", id)
 		if err != nil {
 			return err
@@ -469,7 +469,8 @@ func runDebugExamine(ctx context.Context, gopts GlobalOptions, args []string) er
 		}
 	}
 
-	err = repo.LoadIndex(ctx)
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	err = repo.LoadIndex(ctx, bar)
 	if err != nil {
 		return err
 	}
diff --git a/cmd/restic/cmd_diff.go b/cmd/restic/cmd_diff.go
index accd55db2..125904068 100644
--- a/cmd/restic/cmd_diff.go
+++ b/cmd/restic/cmd_diff.go
@@ -363,8 +363,8 @@ func runDiff(ctx context.Context, opts DiffOptions, gopts GlobalOptions, args []
 	if !gopts.JSON {
 		Verbosef("comparing snapshot %v to %v:\n\n", sn1.ID().Str(), sn2.ID().Str())
 	}
-
-	if err = repo.LoadIndex(ctx); err != nil {
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	if err = repo.LoadIndex(ctx, bar); err != nil {
 		return err
 	}
 
diff --git a/cmd/restic/cmd_dump.go b/cmd/restic/cmd_dump.go
index 325607017..8b9fa9624 100644
--- a/cmd/restic/cmd_dump.go
+++ b/cmd/restic/cmd_dump.go
@@ -152,7 +152,8 @@ func runDump(ctx context.Context, opts DumpOptions, gopts GlobalOptions, args []
 		return errors.Fatalf("failed to find snapshot: %v", err)
 	}
 
-	err = repo.LoadIndex(ctx)
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	err = repo.LoadIndex(ctx, bar)
 	if err != nil {
 		return err
 	}
diff --git a/cmd/restic/cmd_find.go b/cmd/restic/cmd_find.go
index 181d8595d..9c21cc9bb 100644
--- a/cmd/restic/cmd_find.go
+++ b/cmd/restic/cmd_find.go
@@ -589,8 +589,8 @@ func runFind(ctx context.Context, opts FindOptions, gopts GlobalOptions, args []
 	if err != nil {
 		return err
 	}
-
-	if err = repo.LoadIndex(ctx); err != nil {
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	if err = repo.LoadIndex(ctx, bar); err != nil {
 		return err
 	}
 
diff --git a/cmd/restic/cmd_list.go b/cmd/restic/cmd_list.go
index bd02cedc7..5974da9ac 100644
--- a/cmd/restic/cmd_list.go
+++ b/cmd/restic/cmd_list.go
@@ -63,7 +63,7 @@ func runList(ctx context.Context, cmd *cobra.Command, gopts GlobalOptions, args
 	case "locks":
 		t = restic.LockFile
 	case "blobs":
-		return index.ForAllIndexes(ctx, repo, func(id restic.ID, idx *index.Index, oldFormat bool, err error) error {
+		return index.ForAllIndexes(ctx, repo.Backend(), repo, func(id restic.ID, idx *index.Index, oldFormat bool, err error) error {
 			if err != nil {
 				return err
 			}
diff --git a/cmd/restic/cmd_ls.go b/cmd/restic/cmd_ls.go
index 256c9e002..a0c07a752 100644
--- a/cmd/restic/cmd_ls.go
+++ b/cmd/restic/cmd_ls.go
@@ -173,7 +173,8 @@ func runLs(ctx context.Context, opts LsOptions, gopts GlobalOptions, args []stri
 		return err
 	}
 
-	if err = repo.LoadIndex(ctx); err != nil {
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	if err = repo.LoadIndex(ctx, bar); err != nil {
 		return err
 	}
 
diff --git a/cmd/restic/cmd_mount.go b/cmd/restic/cmd_mount.go
index ec3662d5c..04c072daf 100644
--- a/cmd/restic/cmd_mount.go
+++ b/cmd/restic/cmd_mount.go
@@ -130,7 +130,8 @@ func runMount(ctx context.Context, opts MountOptions, gopts GlobalOptions, args
 		}
 	}
 
-	err = repo.LoadIndex(ctx)
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	err = repo.LoadIndex(ctx, bar)
 	if err != nil {
 		return err
 	}
diff --git a/cmd/restic/cmd_prune.go b/cmd/restic/cmd_prune.go
index e4c2c7b29..638a0de5e 100644
--- a/cmd/restic/cmd_prune.go
+++ b/cmd/restic/cmd_prune.go
@@ -187,7 +187,8 @@ func runPruneWithRepo(ctx context.Context, opts PruneOptions, gopts GlobalOption
 
 	Verbosef("loading indexes...\n")
 	// loading the index before the snapshots is ok, as we use an exclusive lock here
-	err := repo.LoadIndex(ctx)
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	err := repo.LoadIndex(ctx, bar)
 	if err != nil {
 		return err
 	}
diff --git a/cmd/restic/cmd_recover.go b/cmd/restic/cmd_recover.go
index 85dcc23d7..63084dd5f 100644
--- a/cmd/restic/cmd_recover.go
+++ b/cmd/restic/cmd_recover.go
@@ -58,7 +58,8 @@ func runRecover(ctx context.Context, gopts GlobalOptions) error {
 	}
 
 	Verbosef("load index files\n")
-	if err = repo.LoadIndex(ctx); err != nil {
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	if err = repo.LoadIndex(ctx, bar); err != nil {
 		return err
 	}
 
@@ -73,7 +74,7 @@ func runRecover(ctx context.Context, gopts GlobalOptions) error {
 	})
 
 	Verbosef("load %d trees\n", len(trees))
-	bar := newProgressMax(!gopts.Quiet, uint64(len(trees)), "trees loaded")
+	bar = newProgressMax(!gopts.Quiet, uint64(len(trees)), "trees loaded")
 	for id := range trees {
 		tree, err := restic.LoadTree(ctx, repo, id)
 		if err != nil {
diff --git a/cmd/restic/cmd_repair_index.go b/cmd/restic/cmd_repair_index.go
index b1905836a..622c77801 100644
--- a/cmd/restic/cmd_repair_index.go
+++ b/cmd/restic/cmd_repair_index.go
@@ -88,7 +88,7 @@ func rebuildIndex(ctx context.Context, opts RepairIndexOptions, gopts GlobalOpti
 	} else {
 		Verbosef("loading indexes...\n")
 		mi := index.NewMasterIndex()
-		err := index.ForAllIndexes(ctx, repo, func(id restic.ID, idx *index.Index, oldFormat bool, err error) error {
+		err := index.ForAllIndexes(ctx, repo.Backend(), repo, func(id restic.ID, idx *index.Index, oldFormat bool, err error) error {
 			if err != nil {
 				Warnf("removing invalid index %v: %v\n", id, err)
 				obsoleteIndexes = append(obsoleteIndexes, id)
diff --git a/cmd/restic/cmd_repair_snapshots.go b/cmd/restic/cmd_repair_snapshots.go
index 03736795c..720523762 100644
--- a/cmd/restic/cmd_repair_snapshots.go
+++ b/cmd/restic/cmd_repair_snapshots.go
@@ -89,7 +89,8 @@ func runRepairSnapshots(ctx context.Context, gopts GlobalOptions, opts RepairOpt
 		return err
 	}
 
-	if err := repo.LoadIndex(ctx); err != nil {
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	if err := repo.LoadIndex(ctx, bar); err != nil {
 		return err
 	}
 
diff --git a/cmd/restic/cmd_restore.go b/cmd/restic/cmd_restore.go
index 9bce90a26..494c6b86a 100644
--- a/cmd/restic/cmd_restore.go
+++ b/cmd/restic/cmd_restore.go
@@ -173,7 +173,8 @@ func runRestore(ctx context.Context, opts RestoreOptions, gopts GlobalOptions,
 		return errors.Fatalf("failed to find snapshot: %v", err)
 	}
 
-	err = repo.LoadIndex(ctx)
+	bar := newIndexTerminalProgress(gopts.Quiet, gopts.JSON, term)
+	err = repo.LoadIndex(ctx, bar)
 	if err != nil {
 		return err
 	}
diff --git a/cmd/restic/cmd_rewrite.go b/cmd/restic/cmd_rewrite.go
index c08797c48..9d9ab5d5d 100644
--- a/cmd/restic/cmd_rewrite.go
+++ b/cmd/restic/cmd_rewrite.go
@@ -212,7 +212,8 @@ func runRewrite(ctx context.Context, opts RewriteOptions, gopts GlobalOptions, a
 		return err
 	}
 
-	if err = repo.LoadIndex(ctx); err != nil {
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	if err = repo.LoadIndex(ctx, bar); err != nil {
 		return err
 	}
 
diff --git a/cmd/restic/cmd_stats.go b/cmd/restic/cmd_stats.go
index a7ecd438f..f16b59d3c 100644
--- a/cmd/restic/cmd_stats.go
+++ b/cmd/restic/cmd_stats.go
@@ -98,8 +98,8 @@ func runStats(ctx context.Context, opts StatsOptions, gopts GlobalOptions, args
 	if err != nil {
 		return err
 	}
-
-	if err = repo.LoadIndex(ctx); err != nil {
+	bar := newIndexProgress(gopts.Quiet, gopts.JSON)
+	if err = repo.LoadIndex(ctx, bar); err != nil {
 		return err
 	}
 
diff --git a/cmd/restic/progress.go b/cmd/restic/progress.go
index 4b6025a54..fe4f654d0 100644
--- a/cmd/restic/progress.go
+++ b/cmd/restic/progress.go
@@ -29,13 +29,12 @@ func calculateProgressInterval(show bool, json bool) time.Duration {
 	return interval
 }
 
-// newProgressMax returns a progress.Counter that prints to stdout.
-func newProgressMax(show bool, max uint64, description string) *progress.Counter {
+// newTerminalProgressMax returns a progress.Counter that prints to stdout or terminal if provided.
+func newGenericProgressMax(show bool, max uint64, description string, print func(status string)) *progress.Counter {
 	if !show {
 		return nil
 	}
 	interval := calculateProgressInterval(show, false)
-	canUpdateStatus := stdoutCanUpdateStatus()
 
 	return progress.NewCounter(interval, max, func(v uint64, max uint64, d time.Duration, final bool) {
 		var status string
@@ -47,14 +46,28 @@ func newProgressMax(show bool, max uint64, description string) *progress.Counter
 				ui.FormatDuration(d), ui.FormatPercent(v, max), v, max, description)
 		}
 
-		printProgress(status, canUpdateStatus)
+		print(status)
 		if final {
 			fmt.Print("\n")
 		}
 	})
 }
 
-func printProgress(status string, canUpdateStatus bool) {
+func newTerminalProgressMax(show bool, max uint64, description string, term *termstatus.Terminal) *progress.Counter {
+	return newGenericProgressMax(show, max, description, func(status string) {
+		term.SetStatus([]string{status})
+	})
+}
+
+// newProgressMax calls newTerminalProgress without a terminal (print to stdout)
+func newProgressMax(show bool, max uint64, description string) *progress.Counter {
+	return newGenericProgressMax(show, max, description, printProgress)
+}
+
+func printProgress(status string) {
+
+	canUpdateStatus := stdoutCanUpdateStatus()
+
 	w := stdoutTerminalWidth()
 	if w > 0 {
 		if w < 3 {
@@ -83,3 +96,11 @@ func printProgress(status string, canUpdateStatus bool) {
 
 	_, _ = os.Stdout.Write([]byte(clear + status + carriageControl))
 }
+
+func newIndexProgress(quiet bool, json bool) *progress.Counter {
+	return newProgressMax(!quiet && !json, 0, "index files loaded")
+}
+
+func newIndexTerminalProgress(quiet bool, json bool, term *termstatus.Terminal) *progress.Counter {
+	return newTerminalProgressMax(!quiet && !json, 0, "index files loaded", term)
+}
diff --git a/internal/checker/checker.go b/internal/checker/checker.go
index b2512969e..a5bb43731 100644
--- a/internal/checker/checker.go
+++ b/internal/checker/checker.go
@@ -113,13 +113,42 @@ func computePackTypes(ctx context.Context, idx restic.MasterIndex) map[restic.ID
 }
 
 // LoadIndex loads all index files.
-func (c *Checker) LoadIndex(ctx context.Context) (hints []error, errs []error) {
+func (c *Checker) LoadIndex(ctx context.Context, p *progress.Counter) (hints []error, errs []error) {
 	debug.Log("Start")
 
+	indexList, err := backend.MemorizeList(ctx, c.repo.Backend(), restic.IndexFile)
+	if err != nil {
+		// abort if an error occurs while listing the indexes
+		return hints, append(errs, err)
+	}
+
+	if p != nil {
+		var numIndexFiles uint64
+		err := indexList.List(ctx, restic.IndexFile, func(fi restic.FileInfo) error {
+			_, err := restic.ParseID(fi.Name)
+			if err != nil {
+				debug.Log("unable to parse %v as an ID", fi.Name)
+				return nil
+			}
+
+			numIndexFiles++
+			return nil
+		})
+		if err != nil {
+			return hints, append(errs, err)
+		}
+		p.SetMax(numIndexFiles)
+		defer p.Done()
+	}
+
 	packToIndex := make(map[restic.ID]restic.IDSet)
-	err := index.ForAllIndexes(ctx, c.repo, func(id restic.ID, index *index.Index, oldFormat bool, err error) error {
+	err = index.ForAllIndexes(ctx, indexList, c.repo, func(id restic.ID, index *index.Index, oldFormat bool, err error) error {
 		debug.Log("process index %v, err %v", id, err)
 
+		if p != nil {
+			p.Add(1)
+		}
+
 		if oldFormat {
 			debug.Log("index %v has old format", id)
 			hints = append(hints, &ErrOldIndexFormat{id})
diff --git a/internal/fuse/snapshots_dirstruct.go b/internal/fuse/snapshots_dirstruct.go
index 3080d4de8..a3cd11b14 100644
--- a/internal/fuse/snapshots_dirstruct.go
+++ b/internal/fuse/snapshots_dirstruct.go
@@ -328,7 +328,7 @@ func (d *SnapshotsDirStructure) updateSnapshots(ctx context.Context) error {
 		return nil
 	}
 
-	err = d.root.repo.LoadIndex(ctx)
+	err = d.root.repo.LoadIndex(ctx, nil)
 	if err != nil {
 		return err
 	}
diff --git a/internal/index/index_parallel.go b/internal/index/index_parallel.go
index e7e46e88a..d505d756e 100644
--- a/internal/index/index_parallel.go
+++ b/internal/index/index_parallel.go
@@ -11,7 +11,7 @@ import (
 // ForAllIndexes loads all index files in parallel and calls the given callback.
 // It is guaranteed that the function is not run concurrently. If the callback
 // returns an error, this function is cancelled and also returns that error.
-func ForAllIndexes(ctx context.Context, repo restic.Repository,
+func ForAllIndexes(ctx context.Context, lister restic.Lister, repo restic.Repository,
 	fn func(id restic.ID, index *Index, oldFormat bool, err error) error) error {
 
 	// decoding an index can take quite some time such that this can be both CPU- or IO-bound
@@ -19,7 +19,7 @@ func ForAllIndexes(ctx context.Context, repo restic.Repository,
 	workerCount := repo.Connections() + uint(runtime.GOMAXPROCS(0))
 
 	var m sync.Mutex
-	return restic.ParallelList(ctx, repo.Backend(), restic.IndexFile, workerCount, func(ctx context.Context, id restic.ID, size int64) error {
+	return restic.ParallelList(ctx, lister, restic.IndexFile, workerCount, func(ctx context.Context, id restic.ID, size int64) error {
 		var err error
 		var idx *Index
 		oldFormat := false
diff --git a/internal/repository/repository.go b/internal/repository/repository.go
index 653c1f774..8ec3c598e 100644
--- a/internal/repository/repository.go
+++ b/internal/repository/repository.go
@@ -581,15 +581,41 @@ func (r *Repository) SetIndex(i restic.MasterIndex) error {
 }
 
 // LoadIndex loads all index files from the backend in parallel and stores them
-// in the master index. The first error that occurred is returned.
-func (r *Repository) LoadIndex(ctx context.Context) error {
+func (r *Repository) LoadIndex(ctx context.Context, p *progress.Counter) error {
 	debug.Log("Loading index")
 
-	err := index.ForAllIndexes(ctx, r, func(id restic.ID, idx *index.Index, oldFormat bool, err error) error {
+	indexList, err := backend.MemorizeList(ctx, r.Backend(), restic.IndexFile)
+	if err != nil {
+		return err
+	}
+
+	if p != nil {
+		var numIndexFiles uint64
+		err := indexList.List(ctx, restic.IndexFile, func(fi restic.FileInfo) error {
+			_, err := restic.ParseID(fi.Name)
+			if err != nil {
+				debug.Log("unable to parse %v as an ID", fi.Name)
+				return nil
+			}
+
+			numIndexFiles++
+			return nil
+		})
+		if err != nil {
+			return err
+		}
+		p.SetMax(numIndexFiles)
+		defer p.Done()
+	}
+
+	err = index.ForAllIndexes(ctx, indexList, r, func(id restic.ID, idx *index.Index, oldFormat bool, err error) error {
 		if err != nil {
 			return err
 		}
 		r.idx.Insert(idx)
+		if p != nil {
+			p.Add(1)
+		}
 		return nil
 	})
 
diff --git a/internal/restic/repository.go b/internal/restic/repository.go
index 6990200e4..a651f9906 100644
--- a/internal/restic/repository.go
+++ b/internal/restic/repository.go
@@ -24,7 +24,7 @@ type Repository interface {
 	Key() *crypto.Key
 
 	Index() MasterIndex
-	LoadIndex(context.Context) error
+	LoadIndex(context.Context, *progress.Counter) error
 	SetIndex(MasterIndex) error
 	LookupBlobSize(ID, BlobType) (uint, bool)
 


Test patch:
diff --git a/cmd/restic/cmd_backup_integration_test.go b/cmd/restic/cmd_backup_integration_test.go
index fb7bef633..76c227e3d 100644
--- a/cmd/restic/cmd_backup_integration_test.go
+++ b/cmd/restic/cmd_backup_integration_test.go
@@ -252,7 +252,7 @@ func TestBackupTreeLoadError(t *testing.T) {
 
 	r, err := OpenRepository(context.TODO(), env.gopts)
 	rtest.OK(t, err)
-	rtest.OK(t, r.LoadIndex(context.TODO()))
+	rtest.OK(t, r.LoadIndex(context.TODO(), nil))
 	treePacks := restic.NewIDSet()
 	r.Index().Each(context.TODO(), func(pb restic.PackedBlob) {
 		if pb.Type == restic.TreeBlob {
diff --git a/cmd/restic/integration_helpers_test.go b/cmd/restic/integration_helpers_test.go
index b7cb5b333..2afdbb938 100644
--- a/cmd/restic/integration_helpers_test.go
+++ b/cmd/restic/integration_helpers_test.go
@@ -258,7 +258,7 @@ func removePacksExcept(gopts GlobalOptions, t testing.TB, keep restic.IDSet, rem
 	rtest.OK(t, err)
 
 	// Get all tree packs
-	rtest.OK(t, r.LoadIndex(context.TODO()))
+	rtest.OK(t, r.LoadIndex(context.TODO(), nil))
 
 	treePacks := restic.NewIDSet()
 	r.Index().Each(context.TODO(), func(pb restic.PackedBlob) {
diff --git a/internal/checker/checker_test.go b/internal/checker/checker_test.go
index 6405ecfbd..ee7e2867c 100644
--- a/internal/checker/checker_test.go
+++ b/internal/checker/checker_test.go
@@ -77,7 +77,7 @@ func TestCheckRepo(t *testing.T) {
 	repo := repository.TestOpenLocal(t, repodir)
 
 	chkr := checker.New(repo, false)
-	hints, errs := chkr.LoadIndex(context.TODO())
+	hints, errs := chkr.LoadIndex(context.TODO(), nil)
 	if len(errs) > 0 {
 		t.Fatalf("expected no errors, got %v: %v", len(errs), errs)
 	}
@@ -103,7 +103,7 @@ func TestMissingPack(t *testing.T) {
 	test.OK(t, repo.Backend().Remove(context.TODO(), packHandle))
 
 	chkr := checker.New(repo, false)
-	hints, errs := chkr.LoadIndex(context.TODO())
+	hints, errs := chkr.LoadIndex(context.TODO(), nil)
 	if len(errs) > 0 {
 		t.Fatalf("expected no errors, got %v: %v", len(errs), errs)
 	}
@@ -136,7 +136,7 @@ func TestUnreferencedPack(t *testing.T) {
 	test.OK(t, repo.Backend().Remove(context.TODO(), indexHandle))
 
 	chkr := checker.New(repo, false)
-	hints, errs := chkr.LoadIndex(context.TODO())
+	hints, errs := chkr.LoadIndex(context.TODO(), nil)
 	if len(errs) > 0 {
 		t.Fatalf("expected no errors, got %v: %v", len(errs), errs)
 	}
@@ -178,7 +178,7 @@ func TestUnreferencedBlobs(t *testing.T) {
 	sort.Sort(unusedBlobsBySnapshot)
 
 	chkr := checker.New(repo, true)
-	hints, errs := chkr.LoadIndex(context.TODO())
+	hints, errs := chkr.LoadIndex(context.TODO(), nil)
 	if len(errs) > 0 {
 		t.Fatalf("expected no errors, got %v: %v", len(errs), errs)
 	}
@@ -258,7 +258,7 @@ func TestModifiedIndex(t *testing.T) {
 	}
 
 	chkr := checker.New(repo, false)
-	hints, errs := chkr.LoadIndex(context.TODO())
+	hints, errs := chkr.LoadIndex(context.TODO(), nil)
 	if len(errs) == 0 {
 		t.Fatalf("expected errors not found")
 	}
@@ -279,7 +279,7 @@ func TestDuplicatePacksInIndex(t *testing.T) {
 	repo := repository.TestOpenLocal(t, repodir)
 
 	chkr := checker.New(repo, false)
-	hints, errs := chkr.LoadIndex(context.TODO())
+	hints, errs := chkr.LoadIndex(context.TODO(), nil)
 	if len(hints) == 0 {
 		t.Fatalf("did not get expected checker hints for duplicate packs in indexes")
 	}
@@ -347,7 +347,7 @@ func TestCheckerModifiedData(t *testing.T) {
 
 	chkr := checker.New(checkRepo, false)
 
-	hints, errs := chkr.LoadIndex(context.TODO())
+	hints, errs := chkr.LoadIndex(context.TODO(), nil)
 	if len(errs) > 0 {
 		t.Fatalf("expected no errors, got %v: %v", len(errs), errs)
 	}
@@ -408,7 +408,7 @@ func TestCheckerNoDuplicateTreeDecodes(t *testing.T) {
 	}
 
 	chkr := checker.New(checkRepo, false)
-	hints, errs := chkr.LoadIndex(context.TODO())
+	hints, errs := chkr.LoadIndex(context.TODO(), nil)
 	if len(errs) > 0 {
 		t.Fatalf("expected no errors, got %v: %v", len(errs), errs)
 	}
@@ -524,7 +524,7 @@ func TestCheckerBlobTypeConfusion(t *testing.T) {
 		delayRepo.Unblock()
 	}()
 
-	hints, errs := chkr.LoadIndex(ctx)
+	hints, errs := chkr.LoadIndex(ctx, nil)
 	if len(errs) > 0 {
 		t.Fatalf("expected no errors, got %v: %v", len(errs), errs)
 	}
@@ -553,7 +553,7 @@ func loadBenchRepository(t *testing.B) (*checker.Checker, restic.Repository, fun
 	repo := repository.TestOpenLocal(t, repodir)
 
 	chkr := checker.New(repo, false)
-	hints, errs := chkr.LoadIndex(context.TODO())
+	hints, errs := chkr.LoadIndex(context.TODO(), nil)
 	if len(errs) > 0 {
 		defer cleanup()
 		t.Fatalf("expected no errors, got %v: %v", len(errs), errs)
diff --git a/internal/checker/testing.go b/internal/checker/testing.go
index 0668406d8..fe1679393 100644
--- a/internal/checker/testing.go
+++ b/internal/checker/testing.go
@@ -11,7 +11,7 @@ import (
 func TestCheckRepo(t testing.TB, repo restic.Repository) {
 	chkr := New(repo, true)
 
-	hints, errs := chkr.LoadIndex(context.TODO())
+	hints, errs := chkr.LoadIndex(context.TODO(), nil)
 	if len(errs) != 0 {
 		t.Fatalf("errors loading index: %v", errs)
 	}
diff --git a/internal/index/index_parallel_test.go b/internal/index/index_parallel_test.go
index 760374510..86be46473 100644
--- a/internal/index/index_parallel_test.go
+++ b/internal/index/index_parallel_test.go
@@ -29,7 +29,7 @@ func TestRepositoryForAllIndexes(t *testing.T) {
 	// check that all expected indexes are loaded without errors
 	indexIDs := restic.NewIDSet()
 	var indexErr error
-	rtest.OK(t, index.ForAllIndexes(context.TODO(), repo, func(id restic.ID, index *index.Index, oldFormat bool, err error) error {
+	rtest.OK(t, index.ForAllIndexes(context.TODO(), repo.Backend(), repo, func(id restic.ID, index *index.Index, oldFormat bool, err error) error {
 		if err != nil {
 			indexErr = err
 		}
@@ -42,7 +42,7 @@ func TestRepositoryForAllIndexes(t *testing.T) {
 	// must failed with the returned error
 	iterErr := errors.New("error to pass upwards")
 
-	err := index.ForAllIndexes(context.TODO(), repo, func(id restic.ID, index *index.Index, oldFormat bool, err error) error {
+	err := index.ForAllIndexes(context.TODO(), repo.Backend(), repo, func(id restic.ID, index *index.Index, oldFormat bool, err error) error {
 		return iterErr
 	})
 
diff --git a/internal/index/master_index_test.go b/internal/index/master_index_test.go
index 5260a11a0..bf8ec3f41 100644
--- a/internal/index/master_index_test.go
+++ b/internal/index/master_index_test.go
@@ -357,7 +357,7 @@ func TestIndexSave(t *testing.T) {
 func testIndexSave(t *testing.T, version uint) {
 	repo := createFilledRepo(t, 3, version)
 
-	err := repo.LoadIndex(context.TODO())
+	err := repo.LoadIndex(context.TODO(), nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -382,7 +382,7 @@ func testIndexSave(t *testing.T, version uint) {
 		t.Error(err)
 	}
 
-	hints, errs := checker.LoadIndex(context.TODO())
+	hints, errs := checker.LoadIndex(context.TODO(), nil)
 	for _, h := range hints {
 		t.Logf("hint: %v\n", h)
 	}
diff --git a/internal/repository/repack_test.go b/internal/repository/repack_test.go
index bb31eba77..c8570a9d4 100644
--- a/internal/repository/repack_test.go
+++ b/internal/repository/repack_test.go
@@ -213,7 +213,7 @@ func reloadIndex(t *testing.T, repo restic.Repository) {
 		t.Fatal(err)
 	}
 
-	if err := repo.LoadIndex(context.TODO()); err != nil {
+	if err := repo.LoadIndex(context.TODO(), nil); err != nil {
 		t.Fatalf("error loading new index: %v", err)
 	}
 }
diff --git a/internal/repository/repository_test.go b/internal/repository/repository_test.go
index f26bf46f2..d362b0b5e 100644
--- a/internal/repository/repository_test.go
+++ b/internal/repository/repository_test.go
@@ -255,7 +255,7 @@ func TestRepositoryLoadIndex(t *testing.T) {
 	defer cleanup()
 
 	repo := repository.TestOpenLocal(t, repodir)
-	rtest.OK(t, repo.LoadIndex(context.TODO()))
+	rtest.OK(t, repo.LoadIndex(context.TODO(), nil))
 }
 
 // loadIndex loads the index id from backend and returns it.
@@ -324,7 +324,7 @@ func TestRepositoryLoadUnpackedRetryBroken(t *testing.T) {
 	err = repo.SearchKey(context.TODO(), rtest.TestPassword, 10, "")
 	rtest.OK(t, err)
 
-	rtest.OK(t, repo.LoadIndex(context.TODO()))
+	rtest.OK(t, repo.LoadIndex(context.TODO(), nil))
 }
 
 func BenchmarkLoadIndex(b *testing.B) {