Stop a stalled snapshot database read when restore or deep verify is interrupted (closes #356)

Restore and deep verify read the snapshot database straight from
storage rather than through FetchBlob, so the earlier fix for stalled
blob reads did not cover it. A database read stalled on a slow USB
stick or network share kept the operation from returning after Ctrl-C;
the process then exited at the shutdown timeout and left the decrypted
database in the temp directory.

Both reads now wrap the storage reader in the close-on-cancel reader
FetchBlob uses, so a cancel ends the stalled read and the temp
directory is removed. The interrupt test now stalls either a blob or
the snapshot database, for both commands.

Limitation: a read stuck in the kernel that closing cannot interrupt,
such as one on an unresponsive hard NFS mount, still cannot be stopped.

Model: opus-5-5

README.md

@@ -293,8 +293,8 @@ needed.
 **`snapshot list`**: Show every snapshot known to this host — the union
 of the local index and the backup destination store — with timestamps
 and three sizes per snapshot (compressed remote size; total
-uncompressed chunk size; size of the chunks that snapshot stored that
-were not stored before, recorded when its backup ran).
+uncompressed chunk size; size of chunks newly referenced by that
+snapshot).
 
 Listing the destination store does **not** require the age secret key,
 so it works in vaultik's intended configuration, where the backed-up
@@ -307,8 +307,8 @@ only the hash, so hostname and snapshot name exist solely in the local
 index and in the encrypted per-snapshot database. Snapshots found only
 on the destination store are therefore listed as
 `<remote only:<abbreviated remote key>>` and show `<remote only>` in
-the uncompressed and "new chunk" columns, which come only from the
-local index. Their timestamp and compressed size are real,
+the uncompressed and "new chunk" columns, which can only be computed
+from the local index. Their timestamp and compressed size are real,
 read from the manifest.
 
 Snapshots in the local index with no counterpart on the destination

docs/DATAMODEL.md

@@ -119,7 +119,6 @@ Tracks backup snapshots.
 - `completed_at` (INTEGER) - Completion timestamp (NULL if in progress)
 - `file_count` (INTEGER) - Number of files in snapshot
 - `chunk_count` (INTEGER) - Number of chunks this snapshot stored that were not stored before
-- `new_chunk_size` (INTEGER) - Total size of those chunks before compression; `snapshot list` shows it as NEW CHUNK SIZE
 - `blob_count` (INTEGER) - Number of blobs this snapshot created
 - `total_size` (INTEGER) - Total size of all files
 - `blob_size` (INTEGER) - Total compressed size of all referenced blobs

internal/database/schema/001.sql

@@ -86,7 +86,6 @@ CREATE TABLE IF NOT EXISTS snapshots (
     completed_at INTEGER,
     file_count INTEGER NOT NULL DEFAULT 0,
     chunk_count INTEGER NOT NULL DEFAULT 0,
-    new_chunk_size INTEGER NOT NULL DEFAULT 0,
     blob_count INTEGER NOT NULL DEFAULT 0,
     total_size INTEGER NOT NULL DEFAULT 0,
     blob_size INTEGER NOT NULL DEFAULT 0,

internal/database/snapshots.go

@@ -129,7 +129,6 @@ func (r *SnapshotRepository) UpdateExtendedStats(
 	compressionLevel int,
 	uploadBytes int64,
 	uploadDurationMs int64,
-	newChunkSize int64,
 ) error {
 	compressionRatio, err := r.extendedCompressionRatio(
 		ctx, tx, snapshotID, blobUncompressedSize,
@@ -144,19 +143,18 @@ func (r *SnapshotRepository) UpdateExtendedStats(
 		    compression_ratio = ?,
 		    compression_level = ?,
 		    upload_bytes = ?,
-		    upload_duration_ms = ?,
-		    new_chunk_size = ?
+		    upload_duration_ms = ?
 		WHERE id = ?
 	`
 
 	if tx != nil {
 		_, err = tx.ExecContext(ctx, query,
 			blobUncompressedSize, compressionRatio, compressionLevel,
-			uploadBytes, uploadDurationMs, newChunkSize, snapshotID)
+			uploadBytes, uploadDurationMs, snapshotID)
 	} else {
 		_, err = r.db.ExecWithLog(ctx, query,
 			blobUncompressedSize, compressionRatio, compressionLevel,
-			uploadBytes, uploadDurationMs, newChunkSize, snapshotID)
+			uploadBytes, uploadDurationMs, snapshotID)
 	}
 
 	if err != nil {
@@ -596,24 +594,45 @@ func (r *SnapshotRepository) GetSnapshotUncompressedChunkSize(
 	return totalSize, nil
 }
 
-// GetSnapshotNewChunkSize returns the total plaintext size of the chunks the
-// snapshot's backup stored that were not stored before, as the backup
-// recorded it. It is not derived from the snapshot's files: a file's row is
-// shared by every snapshot that lists it and is rewritten when the file
-// changes, so it shows only the file's latest chunks.
+// GetSnapshotNewChunkSize returns the sum of plaintext sizes of chunks that are
+// referenced by this snapshot but not by any earlier completed snapshot known to
+// the local database. The result is the marginal uncompressed data this snapshot
+// added to the dedup pool — i.e., the delta from prior snapshots.
 func (r *SnapshotRepository) GetSnapshotNewChunkSize(
 	ctx context.Context, snapshotID string,
 ) (int64, error) {
-	query := `SELECT new_chunk_size FROM snapshots WHERE id = ?`
+	query := `
+		WITH this_snap_chunks AS (
+			SELECT DISTINCT fc.chunk_hash
+			FROM snapshot_files sf
+			JOIN file_chunks fc ON sf.file_id = fc.file_id
+			WHERE sf.snapshot_id = ?
+		),
+		prior_chunks AS (
+			SELECT DISTINCT fc.chunk_hash
+			FROM snapshots s
+			JOIN snapshot_files sf ON sf.snapshot_id = s.id
+			JOIN file_chunks fc ON fc.file_id = sf.file_id
+			WHERE s.completed_at IS NOT NULL
+			  AND s.id != ?
+			  AND s.started_at < (SELECT started_at FROM snapshots WHERE id = ?)
+		)
+		SELECT COALESCE(SUM(c.size), 0)
+		FROM chunks c
+		JOIN this_snap_chunks t ON c.chunk_hash = t.chunk_hash
+		WHERE c.chunk_hash NOT IN (SELECT chunk_hash FROM prior_chunks)
+	`
 
-	var newChunkSize int64
+	var totalSize int64
 
-	err := r.db.conn.QueryRowContext(ctx, query, snapshotID).Scan(&newChunkSize)
+	err := r.db.conn.QueryRowContext(
+		ctx, query, snapshotID, snapshotID, snapshotID,
+	).Scan(&totalSize)
 	if err != nil {
 		return 0, fmt.Errorf("querying new chunk size: %w", err)
 	}
 
-	return newChunkSize, nil
+	return totalSize, nil
 }
 
 // GetIncompleteSnapshots returns all snapshots that haven't been completed

internal/snapshot/scanner.go

@@ -135,9 +135,7 @@ type ScannerConfig struct {
 // are counted per file: BytesScanned is the size of the new and changed
 // files, BytesSkipped that of the unchanged ones. FilesFailed counts the
 // new and changed files that phase 2 could not store; FilesScanned
-// includes them and BytesScanned does not. ChunksCreated counts the
-// chunks that were not already stored, and NewChunkSize is their total
-// size.
+// includes them and BytesScanned does not.
 type ScanResult struct {
 	FilesScanned   int
 	FilesSkipped   int
@@ -147,7 +145,6 @@ type ScanResult struct {
 	BytesSkipped   int64
 	BytesDeleted   int64
 	ChunksCreated  int
-	NewChunkSize   int64
 	BlobsCreated   int
 	BlobsUploaded  int
 	BytesUploaded  int64
@@ -1869,12 +1866,11 @@ func (s *Scanner) processFileStreaming(
 	return nil
 }
 
-// updateChunkStats counts a chunk that was not already stored, and its
-// size. The scan result's file counts, BytesScanned and BytesSkipped are
-// not touched here: the scan phase counts each file once.
+// updateChunkStats counts a chunk that was not already stored. The scan
+// result's file counts, BytesScanned and BytesSkipped are not touched
+// here: the scan phase counts each file once.
 func (s *Scanner) updateChunkStats(chunkSize int64, result *ScanResult) {
 	result.ChunksCreated++
-	result.NewChunkSize += chunkSize
 
 	if s.progress != nil {
 		s.progress.GetStats().ChunksCreated.Add(1)

internal/snapshot/snapshot.go

@@ -199,7 +199,6 @@ func (sm *SnapshotManager) UpdateSnapshotStatsExtended(
 			stats.CompressionLevel,
 			stats.BytesUploaded,
 			stats.UploadDurationMs,
-			stats.NewChunkSize,
 		)
 	})
 }
@@ -907,7 +906,6 @@ type ExtendedBackupStats struct {
 	BlobUncompressedSize int64 // Total uncompressed size of all referenced blobs
 	CompressionLevel     int   // Compression level used for this snapshot
 	UploadDurationMs     int64 // Total milliseconds spent uploading to S3
-	NewChunkSize         int64 // Total size of the chunks counted in ChunksCreated
 }
 
 // deleteOtherSnapshots deletes all snapshots except the current one

internal/vaultik/new_chunk_size_test.go

@@ -1,133 +0,0 @@
-package vaultik_test
-
-import (
-	"bytes"
-	"context"
-	"maps"
-	"path/filepath"
-	"testing"
-
-	"github.com/spf13/afero"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"sneak.berlin/go/vaultik/internal/chunker"
-	"sneak.berlin/go/vaultik/internal/database"
-	"sneak.berlin/go/vaultik/internal/log"
-	"sneak.berlin/go/vaultik/internal/storage"
-	"sneak.berlin/go/vaultik/internal/vaultik"
-)
-
-// TestNewChunkSizeOfChangedFileStaysFixed covers
-// https://git.eeqj.de/sneak/vaultik/issues/311. A backup whose only change
-// is a modified file lists the size of the chunks that change added as its
-// NEW CHUNK SIZE, and a later backup that changes the file again leaves
-// every earlier snapshot's figure as it was. The file's row in the local
-// index is shared by all three snapshots and rewritten by each backup.
-func TestNewChunkSizeOfChangedFileStaysFixed(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	fs := afero.NewOsFs()
-	tempDir := t.TempDir()
-	dataDir := filepath.Join(tempDir, "src")
-	dbPath := filepath.Join(tempDir, "index.sqlite")
-	changedPath := filepath.Join(dataDir, "changed.bin")
-
-	ctx := context.Background()
-	files := writeFaultSourceTree(t, fs, dataDir)
-	cfg := changedFileConfig(dataDir, dbPath)
-
-	appendRandomBytes(t, fs, files, changedPath, appendedFileSize)
-
-	store, err := storage.NewFileStorer(filepath.Join(tempDir, "remote"))
-	require.NoError(t, err)
-
-	db, err := database.New(ctx, dbPath)
-	require.NoError(t, err)
-	t.Cleanup(func() { _ = db.Close() })
-
-	repos := database.NewRepositories(db)
-	v := newBackupVaultik(ctx, cfg, store, repos, db, fs)
-
-	require.NoError(t, backUp(v, "first"))
-
-	firstFiles := maps.Clone(files)
-	firstID := localSnapshotID(ctx, t, repos, "first")
-
-	appendRandomBytes(t, fs, files, changedPath, faultChunkSize)
-	require.NoError(t, backUp(v, "second"))
-
-	secondID := localSnapshotID(ctx, t, repos, "second")
-	secondAdded := sizeOfNewChunks(t, files, firstFiles)
-	require.Positive(t, secondAdded)
-	assert.Equal(t, secondAdded, listedNewChunkSizes(t, v)[secondID],
-		"the second snapshot must count the chunks the change added")
-
-	appendRandomBytes(t, fs, files, changedPath, faultChunkSize)
-	require.NoError(t, backUp(v, "third"))
-
-	sizes := listedNewChunkSizes(t, v)
-	assert.Equal(t, sizeOfNewChunks(t, firstFiles, nil), sizes[firstID],
-		"a later backup must not change the first snapshot's figure")
-	assert.Equal(t, secondAdded, sizes[secondID],
-		"a later backup must not change the second snapshot's figure")
-}
-
-// sizeOfNewChunks returns the total size of the distinct chunks of the
-// files in after that no file in before has, cut the way the backup cuts
-// them.
-func sizeOfNewChunks(t *testing.T, after, before map[string][]byte) int64 {
-	t.Helper()
-
-	known := make(map[string]bool)
-	for _, chunk := range chunksOf(t, before) {
-		known[chunk.Hash] = true
-	}
-
-	var total int64
-
-	for _, chunk := range chunksOf(t, after) {
-		if !known[chunk.Hash] {
-			known[chunk.Hash] = true
-			total += chunk.Size
-		}
-	}
-
-	return total
-}
-
-// chunksOf returns the chunks of every file in files.
-func chunksOf(t *testing.T, files map[string][]byte) []chunker.Chunk {
-	t.Helper()
-
-	c := chunker.NewChunker(faultChunkSize)
-
-	var all []chunker.Chunk
-
-	for _, content := range files {
-		chunks, err := c.ChunkReader(bytes.NewReader(content))
-		require.NoError(t, err)
-
-		all = append(all, chunks...)
-	}
-
-	return all
-}
-
-// listedNewChunkSizes runs `snapshot list --json` and returns each listed
-// snapshot's new_chunk_size by snapshot ID.
-func listedNewChunkSizes(t *testing.T, v *vaultik.Vaultik) map[string]int64 {
-	t.Helper()
-
-	var out bytes.Buffer
-
-	v.Stdout = &out
-	require.NoError(t, v.ListSnapshots(true))
-
-	sizes := make(map[string]int64)
-	for _, row := range decodeListJSON(t, out.String()) {
-		sizes[row.ID] = row.NewChunkSize
-	}
-
-	return sizes
-}

internal/vaultik/restore.go

@@ -309,22 +309,11 @@ func (v *Vaultik) restoreAllFiles(
 		return nil, err
 	}
 
-	plan, unplanned, err := newRestorePlan(
-		v.ctx, repos, files, chunkToBlobMap, blobIDToHash)
+	plan, err := newRestorePlan(v.ctx, repos, files, chunkToBlobMap, blobIDToHash)
 	if err != nil {
 		return nil, fmt.Errorf("building restore plan: %w", err)
 	}
 
-	// Ranging over files rather than the map reports them in a stable order.
-	for _, file := range files {
-		if planErr, ok := unplanned[file.ID]; ok {
-			err = v.handleRestoreFileError(plan, opts, result, file, file.ID, planErr)
-			if err != nil {
-				return nil, err
-			}
-		}
-	}
-
 	filesByID, totalBytesExpected := indexRestoreFiles(files)
 
 	v.UI.Beginf("Restoring %s files (%s) to %s.",
@@ -702,6 +691,8 @@ func (v *Vaultik) downloadSnapshotDB(
 		return nil, "", fmt.Errorf("downloading %s: %w", dbKey, err)
 	}
 
+	reader = newCloseOnCancelReader(v.ctx, reader)
+
 	defer func() { _ = reader.Close() }()
 
 	// Decrypt and decompress straight from the storage stream, then stream

internal/vaultik/restore_interrupt_test.go

@@ -207,30 +207,37 @@ func TestRestoreSkipErrorsCancelDuringBlobDownload(t *testing.T) {
 		"the cancel was reported as a failed file")
 }
 
-// stallingBlobStorer wraps a Storer so that every blob download hands
-// over the first half of the blob and then stalls, ignoring the context,
-// as a file:// blob on a hung USB stick or network share does. Only
-// closing the returned reader ends the stall.
-type stallingBlobStorer struct {
+// stallingStorer wraps a Storer so that each download of a key chosen by
+// stalls hands over the first half of the object and then stalls,
+// ignoring the context, as a file:// read on a hung USB stick or network
+// share does. Only closing the returned reader ends the stall.
+type stallingStorer struct {
 	storage.Storer
 
+	stalls  func(key string) bool
 	once    sync.Once
 	stalled chan struct{}
 }
 
-func newStallingBlobStorer(inner storage.Storer) *stallingBlobStorer {
-	return &stallingBlobStorer{Storer: inner, stalled: make(chan struct{})}
+func newStallingStorer(
+	inner storage.Storer, stalls func(key string) bool,
+) *stallingStorer {
+	return &stallingStorer{
+		Storer:  inner,
+		stalls:  stalls,
+		stalled: make(chan struct{}),
+	}
 }
 
-func (s *stallingBlobStorer) Get(
+func (s *stallingStorer) Get(
 	ctx context.Context, key string,
 ) (io.ReadCloser, error) {
 	rc, err := s.Storer.Get(ctx, key)
-	if err != nil || !strings.HasPrefix(key, "blobs/") {
+	if err != nil || !s.stalls(key) {
 		return rc, err
 	}
 
-	blob, err := io.ReadAll(rc)
+	object, err := io.ReadAll(rc)
 	_ = rc.Close()
 
 	if err != nil {
@@ -242,7 +249,7 @@ func (s *stallingBlobStorer) Get(
 	pr, pw := io.Pipe()
 
 	go func() {
-		_, _ = pw.Write(blob[:len(blob)/2])
+		_, _ = pw.Write(object[:len(object)/2])
 
 		s.once.Do(func() { close(s.stalled) })
 	}()
@@ -250,17 +257,26 @@ func (s *stallingBlobStorer) Get(
 	return pr, nil
 }
 
-// TestInterruptDuringStalledBlobReadCleansTempDir stops a restore and a
-// deep verify while a blob read is stalled on a source that ignores the
-// context. Stopping must end that read, so the operation unwinds and
-// removes its decrypted scratch files well within the shutdown timeout
-// (issue #325).
+// TestInterruptDuringStalledReadCleansTempDir stops a restore and a deep
+// verify while a read of a blob or of the snapshot database is stalled
+// on a source that ignores the context. Stopping must end that read, so
+// the operation unwinds and removes its decrypted scratch files well
+// within the shutdown timeout (issues #325 and #356).
 //
 // Not parallel: it points TMPDIR at a private directory (via t.Setenv)
 // so it can assert on exactly the scratch files the operation created.
-func TestInterruptDuringStalledBlobReadCleansTempDir(t *testing.T) {
+func TestInterruptDuringStalledReadCleansTempDir(t *testing.T) {
 	log.Initialize(log.Config{})
 
+	stalledReads := map[string]func(key string) bool{
+		"blob": func(key string) bool {
+			return strings.HasPrefix(key, "blobs/")
+		},
+		"snapshot database": func(key string) bool {
+			return strings.HasSuffix(key, "/db.zst.age")
+		},
+	}
+
 	operations := map[string]func(v *Vaultik, snapshotID, targetDir string) error{
 		"restore": func(v *Vaultik, snapshotID, targetDir string) error {
 			return v.Restore(&RestoreOptions{
@@ -273,52 +289,58 @@ func TestInterruptDuringStalledBlobReadCleansTempDir(t *testing.T) {
 		},
 	}
 
-	for name, op := range operations {
-		t.Run(name, func(t *testing.T) {
-			fs := afero.NewOsFs()
-			root := t.TempDir()
+	for readName, stalls := range stalledReads {
+		for opName, op := range operations {
+			t.Run(readName+" read during "+opName, func(t *testing.T) {
+				fs := afero.NewOsFs()
+				root := t.TempDir()
 
-			// Random content, so the blob stays large enough to stall
-			// part-way through its compressed, encrypted body.
-			cfg, storer, snapshotID, _ := backupOneFile(context.Background(),
-				t, fs, root, "a.bin", randomBytes(t, 256*1024), 0o644)
+				// Random content, so the blob stays large enough to stall
+				// part-way through its compressed, encrypted body.
+				cfg, storer, snapshotID, _ := backupOneFile(context.Background(),
+					t, fs, root, "a.bin", randomBytes(t, 256*1024), 0o644)
 
-			scratch := filepath.Join(root, "scratch")
-			require.NoError(t, fs.MkdirAll(scratch, 0o755))
-			t.Setenv("TMPDIR", scratch)
+				scratch := filepath.Join(root, "scratch")
+				require.NoError(t, fs.MkdirAll(scratch, 0o755))
+				t.Setenv("TMPDIR", scratch)
 
-			stalling := newStallingBlobStorer(storer)
+				stalling := newStallingStorer(storer, stalls)
 
-			ctx, cancel := context.WithCancel(context.Background())
-			defer cancel()
+				ctx, cancel := context.WithCancel(context.Background())
+				defer cancel()
 
-			v := newRestoreVaultik(ctx, cfg, stalling, fs)
-			v.cancel = cancel
+				v := newRestoreVaultik(ctx, cfg, stalling, fs)
+				v.cancel = cancel
 
-			var opErr error
+				var opErr error
 
-			stop := v.StartOperation(func() {
-				opErr = op(v, snapshotID, filepath.Join(root, "restored"))
+				stop := v.StartOperation(func() {
+					opErr = op(v, snapshotID, filepath.Join(root, "restored"))
+				})
+
+				select {
+				case <-stalling.stalled:
+				case <-time.After(30 * time.Second):
+					t.Fatal("the operation never reached the stalled read")
+				}
+
+				// The snapshot database's temp directory is created just
+				// after its read starts, so it can appear after the stall.
+				require.Eventually(t, func() bool {
+					return len(scratchEntries(t, scratch)) > 0
+				}, 10*time.Second, 10*time.Millisecond,
+					"expected decrypted scratch files to exist mid-read")
+
+				stopCtx, stopCancel := context.WithTimeout(
+					context.Background(), 10*time.Second)
+				defer stopCancel()
+
+				require.True(t, stop(stopCtx),
+					"stop timed out; the stalled read was not interrupted")
+				require.ErrorIs(t, opErr, context.Canceled)
+				require.Empty(t, scratchEntries(t, scratch),
+					"decrypted scratch files remained after the interrupt")
 			})
-
-			select {
-			case <-stalling.stalled:
-			case <-time.After(30 * time.Second):
-				t.Fatal("the operation never reached a blob read")
-			}
-
-			require.NotEmpty(t, scratchEntries(t, scratch),
-				"expected decrypted scratch files to exist mid-read")
-
-			stopCtx, stopCancel := context.WithTimeout(
-				context.Background(), 10*time.Second)
-			defer stopCancel()
-
-			require.True(t, stop(stopCtx),
-				"stop timed out; the stalled blob read was not interrupted")
-			require.ErrorIs(t, opErr, context.Canceled)
-			require.Empty(t, scratchEntries(t, scratch),
-				"decrypted scratch files remained after the interrupt")
-		})
+		}
 	}
 }

internal/vaultik/restore_malformed_db_test.go

@@ -61,8 +61,8 @@ func craftedFile(
 }
 
 // TestRestoreShortChunkHashInNoBlob proves a file whose short chunk hash
-// has no blob_chunks row is left out of the restore plan with an error,
-// and fails the chunk write with an error.
+// has no blob_chunks row fails restore planning and the chunk write with
+// an error.
 func TestRestoreShortChunkHashInNoBlob(t *testing.T) {
 	t.Parallel()
 
@@ -77,11 +77,9 @@ func TestRestoreShortChunkHashInNoBlob(t *testing.T) {
 	chunkToBlobMap, err := v.buildChunkToBlobMap(ctx, repos)
 	require.NoError(t, err)
 
-	plan, unplanned, err := newRestorePlan(ctx, repos, []*database.File{file},
+	_, err = newRestorePlan(ctx, repos, []*database.File{file},
 		chunkToBlobMap, map[string]string{})
-	require.NoError(t, err)
-	require.ErrorIs(t, unplanned[file.ID], errPlanChunkMissing)
-	require.False(t, plan.hasPending())
+	require.ErrorIs(t, err, errPlanChunkMissing)
 
 	fileChunks, err := repos.FileChunks.GetByFileID(ctx, file.ID)
 	require.NoError(t, err)

internal/vaultik/restore_plan.go

@@ -41,25 +41,20 @@ type restorePlan struct {
 
 // newRestorePlan builds the file→blob index for the given files. Files
 // whose chunks reference no blobs (symlinks, directories) start in the
-// ready queue immediately. A file with a chunk that no blob holds cannot
-// be restored: it is left out of the plan and returned, by ID, with the
-// reason.
+// ready queue immediately.
 func newRestorePlan(
 	ctx context.Context,
 	repos *database.Repositories,
 	files []*database.File,
 	chunkToBlobMap map[string]*database.BlobChunk,
 	blobIDToHash map[string]string,
-) (*restorePlan, map[types.FileID]error, error) {
+) (*restorePlan, error) {
 	p := &restorePlan{
 		fileBlobs: make(map[types.FileID]map[string]struct{}, len(files)),
 		blobFiles: make(map[string]map[types.FileID]struct{}),
 		ready:     make([]types.FileID, 0, len(files)),
 		cached:    make(map[string]struct{}),
 	}
-	unplanned := make(map[types.FileID]error)
-
-nextFile:
 	for _, f := range files {
 		if f.IsSymlink() || f.Mode&uint32(os.ModeDir) != 0 {
 			// No chunks to fetch — restore can run immediately.
@@ -71,7 +66,7 @@ nextFile:
 
 		fileChunks, err := repos.FileChunks.GetByFileID(ctx, f.ID)
 		if err != nil {
-			return nil, nil, fmt.Errorf("planning %s: %w", f.Path, err)
+			return nil, fmt.Errorf("planning %s: %w", f.Path, err)
 		}
 
 		blobs := make(map[string]struct{})
@@ -79,18 +74,14 @@ nextFile:
 		for _, fc := range fileChunks {
 			bc, ok := chunkToBlobMap[fc.ChunkHash.String()]
 			if !ok {
-				unplanned[f.ID] = fmt.Errorf("%w: %s",
-					errPlanChunkMissing, shortHash(fc.ChunkHash.String()))
-
-				continue nextFile
+				return nil, fmt.Errorf("planning %s: %w: %s",
+					f.Path, errPlanChunkMissing, shortHash(fc.ChunkHash.String()))
 			}
 
 			hash, ok := blobIDToHash[bc.BlobID.String()]
 			if !ok {
-				unplanned[f.ID] = fmt.Errorf("%w: %s",
-					errPlanBlobIDMissing, bc.BlobID)
-
-				continue nextFile
+				return nil, fmt.Errorf("planning %s: %w: %s",
+					f.Path, errPlanBlobIDMissing, bc.BlobID)
 			}
 
 			blobs[hash] = struct{}{}
@@ -112,7 +103,7 @@ nextFile:
 		}
 	}
 
-	return p, unplanned, nil
+	return p, nil
 }
 
 // markBlobCached records that the named blob is now resident in the

internal/vaultik/restore_skip_errors_test.go

@@ -28,8 +28,7 @@ const (
 )
 
 // missingBlobBackup is a snapshot of single-chunk files spread over two
-// blobs, with one of those blobs lost: deleted from the store, or missing
-// from the snapshot metadata.
+// blobs, with one of those blobs deleted from the store.
 type missingBlobBackup struct {
 	fs         afero.Fs
 	cfg        *config.Config
@@ -38,39 +37,20 @@ type missingBlobBackup struct {
 	restoreDir string
 	// files holds the original content by source path.
 	files map[string][]byte
-	// lost holds the source paths whose chunk is in the lost blob.
+	// lost holds the source paths whose chunk is in the deleted blob.
 	lost map[string]bool
 }
 
 // TestRestoreSkipErrorsSkipsFilesOfMissingBlob restores with SkipErrors
-// after one blob of a two-blob snapshot was deleted from the store.
+// after one blob of a two-blob snapshot was deleted. Every file stored in
+// that blob must be reported as failed and left absent, every other file
+// must be restored intact, and Restore must still return an error.
 func TestRestoreSkipErrorsSkipsFilesOfMissingBlob(t *testing.T) {
 	log.Initialize(log.Config{})
 	t.Parallel()
 
 	ctx := context.Background()
-	assertRestoreSkipsLostFiles(ctx, t, backupThenDeleteOneBlob(ctx, t))
-}
-
-// TestRestoreSkipErrorsSkipsFilesWithChunkInNoBlob restores with
-// SkipErrors a snapshot whose metadata lists chunks that no blob holds, as
-// earlier backup defects left behind.
-func TestRestoreSkipErrorsSkipsFilesWithChunkInNoBlob(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	ctx := context.Background()
-	assertRestoreSkipsLostFiles(ctx, t, backupThenDropOneBlobFromMetadata(ctx, t))
-}
-
-// assertRestoreSkipsLostFiles restores backup with SkipErrors. Every file
-// stored in the lost blob must be reported as failed and left absent,
-// every other file must be restored intact, and Restore must still return
-// an error.
-func assertRestoreSkipsLostFiles(
-	ctx context.Context, t *testing.T, backup *missingBlobBackup,
-) {
-	t.Helper()
+	backup := backupThenDeleteOneBlob(ctx, t)
 
 	var out bytes.Buffer
 
@@ -92,14 +72,14 @@ func assertRestoreSkipsLostFiles(
 
 		if backup.lost[path] {
 			assert.Containsf(t, out.String(), path,
-				"%s needs the lost blob and must be reported", path)
+				"%s needs the deleted blob and must be reported", path)
 			assert.NoFileExists(t, restored)
 
 			continue
 		}
 
 		got, err := afero.ReadFile(backup.fs, restored)
-		require.NoErrorf(t, err, "%s does not need the lost blob", path)
+		require.NoErrorf(t, err, "%s does not need the deleted blob", path)
 		assert.Equalf(t, content, got, "%s restored with wrong content", path)
 	}
 }
@@ -123,30 +103,6 @@ func TestRestoreMissingBlobAbortsWithoutSkipErrors(t *testing.T) {
 	require.ErrorIs(t, err, storage.ErrNotFound)
 }
 
-// TestRestoreChunkInNoBlobAbortsWithoutSkipErrors checks that a chunk held
-// by no blob still ends the restore, before any file is written, when
-// SkipErrors is not set.
-func TestRestoreChunkInNoBlobAbortsWithoutSkipErrors(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	ctx := context.Background()
-	backup := backupThenDropOneBlobFromMetadata(ctx, t)
-
-	v := newReaderVaultik(ctx, backup.cfg, backup.storer, nil, backup.fs)
-
-	err := v.Restore(&vaultik.RestoreOptions{
-		SnapshotID: backup.snapshotID,
-		TargetDir:  backup.restoreDir,
-	})
-
-	require.ErrorContains(t, err, "chunk missing from blob map")
-
-	for path := range backup.files {
-		assert.NoFileExists(t, filepath.Join(backup.restoreDir, path))
-	}
-}
-
 // backupThenDeleteOneBlob backs up missingBlobFileCount single-chunk
 // files, then deletes from the store the blob holding the first of them.
 func backupThenDeleteOneBlob(
@@ -154,54 +110,6 @@ func backupThenDeleteOneBlob(
 ) *missingBlobBackup {
 	t.Helper()
 
-	backup, db, lostBlob := backupSingleChunkFiles(ctx, t)
-	require.NoError(t, db.Close())
-
-	require.NoError(t, backup.storer.Delete(ctx, fmt.Sprintf(
-		"blobs/%s/%s/%s", lostBlob[:2], lostBlob[2:4], lostBlob)))
-
-	return backup
-}
-
-// backupThenDropOneBlobFromMetadata backs up missingBlobFileCount
-// single-chunk files, then removes the blob holding the first of them from
-// the snapshot and exports the snapshot metadata again. The exported
-// metadata then lists chunks that no blob holds.
-func backupThenDropOneBlobFromMetadata(
-	ctx context.Context, t *testing.T,
-) *missingBlobBackup {
-	t.Helper()
-
-	backup, db, lostBlob := backupSingleChunkFiles(ctx, t)
-
-	// The uploads row refers to the blob row, so it would keep the export
-	// from deleting it.
-	for _, query := range []string{
-		"DELETE FROM snapshot_blobs WHERE blob_hash = ?",
-		"DELETE FROM uploads WHERE blob_hash = ?",
-	} {
-		_, err := db.Conn().ExecContext(ctx, query, lostBlob)
-		require.NoError(t, err)
-	}
-
-	sm := newFaultSnapshotManager(
-		backup.fs, backup.storer, backup.cfg, database.NewRepositories(db))
-	require.NoError(t,
-		sm.ExportSnapshotMetadata(ctx, db.Path(), backup.snapshotID))
-	require.NoError(t, db.Close())
-
-	return backup
-}
-
-// backupSingleChunkFiles backs up missingBlobFileCount single-chunk files.
-// It returns the backup, with lost naming the files stored in the same
-// blob as the first of them, the still open local index, and the hash of
-// that blob.
-func backupSingleChunkFiles(
-	ctx context.Context, t *testing.T,
-) (*missingBlobBackup, *database.DB, string) {
-	t.Helper()
-
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
@@ -235,11 +143,16 @@ func backupSingleChunkFiles(
 		blobOfFile[path] = blobHashOfSingleChunkFile(ctx, t, repos, path)
 	}
 
-	lostBlob := blobOfFile[filepath.Join(dataDir, "file-00.bin")]
+	require.NoError(t, db.Close())
+
+	deleted := blobOfFile[filepath.Join(dataDir, "file-00.bin")]
+	require.NoError(t, storer.Delete(ctx, fmt.Sprintf(
+		"blobs/%s/%s/%s", deleted[:2], deleted[2:4], deleted)))
+
 	lost := make(map[string]bool)
 
 	for path, hash := range blobOfFile {
-		if hash == lostBlob {
+		if hash == deleted {
 			lost[path] = true
 		}
 	}
@@ -255,7 +168,7 @@ func backupSingleChunkFiles(
 		restoreDir: filepath.Join(tempDir, "restored"),
 		files:      files,
 		lost:       lost,
-	}, db, lostBlob
+	}
 }
 
 // blobHashOfSingleChunkFile returns the hash of the blob holding the one

internal/vaultik/snapshot.go

@@ -209,7 +209,6 @@ type snapshotStats struct {
 	totalFiles         int
 	totalBytes         int64
 	totalChunks        int
-	newChunkSize       int64
 	totalBlobs         int
 	totalBytesSkipped  int64
 	totalFilesSkipped  int
@@ -342,7 +341,6 @@ func (v *Vaultik) scanAllDirectories(
 		stats.totalFiles += result.FilesScanned
 		stats.totalBytes += result.BytesScanned
 		stats.totalChunks += result.ChunksCreated
-		stats.newChunkSize += result.NewChunkSize
 		stats.totalBlobs += result.BlobsCreated
 		stats.totalFilesSkipped += result.FilesSkipped
 		stats.totalFilesFailed += result.FilesFailed
@@ -405,7 +403,6 @@ func (v *Vaultik) finalizeSnapshotMetadata(
 		BlobUncompressedSize: stats.blobUncompressedSize,
 		CompressionLevel:     v.Config.CompressionLevel,
 		UploadDurationMs:     stats.uploadDuration.Milliseconds(),
-		NewChunkSize:         stats.newChunkSize,
 	}
 
 	err = v.SnapshotManager.UpdateSnapshotStatsExtended(v.ctx, snapshotID, extStats)

internal/vaultik/snapshot_list_test.go

@@ -487,7 +487,6 @@ type listJSONRow struct {
 	RemoteKey      string `json:"remote_key"`
 	Timestamp      string `json:"timestamp"`
 	CompressedSize int64  `json:"compressed_size"`
-	NewChunkSize   int64  `json:"new_chunk_size"`
 	LocallyTracked bool   `json:"locally_tracked"`
 	RemotePresent  *bool  `json:"remote_present"`
 }

internal/vaultik/verify.go

@@ -246,6 +246,8 @@ func (v *Vaultik) downloadVerifiedSnapshotDB(
 			fmt.Errorf("failed to download database: %w", err))
 	}
 
+	dbReader = newCloseOnCancelReader(v.ctx, dbReader)
+
 	defer func() { _ = dbReader.Close() }()
 
 	tdb, err := v.decryptAndLoadDatabase(dbReader, identities)