Merge pull request #4644 from MichaelEischer/refactor-repair-packs

Refactor and test `repair packs`

internal/index/master_index.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/restic"
-	"github.com/restic/restic/internal/ui/progress"
 	"golang.org/x/sync/errgroup"
 )
 
@@ -267,23 +266,22 @@ func (mi *MasterIndex) MergeFinalIndexes() error {
 
 // Save saves all known indexes to index files, leaving out any
 // packs whose ID is contained in packBlacklist from finalized indexes.
-// The new index contains the IDs of all known indexes in the "supersedes"
-// field. The IDs are also returned in the IDSet obsolete.
-// After calling this function, you should remove the obsolete index files.
-func (mi *MasterIndex) Save(ctx context.Context, repo restic.SaverUnpacked, packBlacklist restic.IDSet, extraObsolete restic.IDs, p *progress.Counter) (obsolete restic.IDSet, err error) {
-	p.SetMax(uint64(len(mi.Packs(packBlacklist))))
+// It also removes the old index files and those listed in extraObsolete.
+func (mi *MasterIndex) Save(ctx context.Context, repo restic.Repository, excludePacks restic.IDSet, extraObsolete restic.IDs, opts restic.MasterIndexSaveOpts) error {
+	p := opts.SaveProgress
+	p.SetMax(uint64(len(mi.Packs(excludePacks))))
 
 	mi.idxMutex.Lock()
 	defer mi.idxMutex.Unlock()
 
-	debug.Log("start rebuilding index of %d indexes, pack blacklist: %v", len(mi.idx), packBlacklist)
+	debug.Log("start rebuilding index of %d indexes, excludePacks: %v", len(mi.idx), excludePacks)
 
 	newIndex := NewIndex()
-	obsolete = restic.NewIDSet()
+	obsolete := restic.NewIDSet()
 
 	// track spawned goroutines using wg, create a new context which is
 	// cancelled as soon as an error occurs.
-	wg, ctx := errgroup.WithContext(ctx)
+	wg, wgCtx := errgroup.WithContext(ctx)
 
 	ch := make(chan *Index)
 
@@ -310,21 +308,21 @@ func (mi *MasterIndex) Save(ctx context.Context, repo restic.SaverUnpacked, pack
 
 			debug.Log("adding index %d", i)
 
-			for pbs := range idx.EachByPack(ctx, packBlacklist) {
+			for pbs := range idx.EachByPack(wgCtx, excludePacks) {
 				newIndex.StorePack(pbs.PackID, pbs.Blobs)
 				p.Add(1)
 				if IndexFull(newIndex, mi.compress) {
 					select {
 					case ch <- newIndex:
-					case <-ctx.Done():
-						return ctx.Err()
+					case <-wgCtx.Done():
+						return wgCtx.Err()
 					}
 					newIndex = NewIndex()
 				}
 			}
 		}
 
-		err = newIndex.AddToSupersedes(extraObsolete...)
+		err := newIndex.AddToSupersedes(extraObsolete...)
 		if err != nil {
 			return err
 		}
@@ -332,7 +330,7 @@ func (mi *MasterIndex) Save(ctx context.Context, repo restic.SaverUnpacked, pack
 
 		select {
 		case ch <- newIndex:
-		case <-ctx.Done():
+		case <-wgCtx.Done():
 		}
 		return nil
 	})
@@ -341,7 +339,7 @@ func (mi *MasterIndex) Save(ctx context.Context, repo restic.SaverUnpacked, pack
 	worker := func() error {
 		for idx := range ch {
 			idx.Finalize()
-			if _, err := SaveIndex(ctx, repo, idx); err != nil {
+			if _, err := SaveIndex(wgCtx, repo, idx); err != nil {
 				return err
 			}
 		}
@@ -354,9 +352,27 @@ func (mi *MasterIndex) Save(ctx context.Context, repo restic.SaverUnpacked, pack
 	for i := 0; i < workerCount; i++ {
 		wg.Go(worker)
 	}
-	err = wg.Wait()
+	err := wg.Wait()
+	p.Done()
+	if err != nil {
+		return err
+	}
 
-	return obsolete, err
+	if opts.SkipDeletion {
+		return nil
+	}
+
+	p = nil
+	if opts.DeleteProgress != nil {
+		p = opts.DeleteProgress()
+	}
+	defer p.Done()
+	return restic.ParallelRemove(ctx, repo, obsolete, restic.IndexFile, func(id restic.ID, err error) error {
+		if opts.DeleteReport != nil {
+			opts.DeleteReport(id, err)
+		}
+		return err
+	}, p)
 }
 
 // SaveIndex saves an index in the repository.

internal/index/master_index_test.go

@@ -8,7 +8,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/checker"
 	"github.com/restic/restic/internal/crypto"
 	"github.com/restic/restic/internal/index"
@@ -363,20 +362,11 @@ func testIndexSave(t *testing.T, version uint) {
 		t.Fatal(err)
 	}
 
-	obsoletes, err := repo.Index().Save(context.TODO(), repo, nil, nil, nil)
+	err = repo.Index().Save(context.TODO(), repo, nil, nil, restic.MasterIndexSaveOpts{})
 	if err != nil {
 		t.Fatalf("unable to save new index: %v", err)
 	}
 
-	for id := range obsoletes {
-		t.Logf("remove index %v", id.Str())
-		h := backend.Handle{Type: restic.IndexFile, Name: id.String()}
-		err = repo.Backend().Remove(context.TODO(), h)
-		if err != nil {
-			t.Errorf("error removing index %v: %v", id, err)
-		}
-	}
-
 	checker := checker.New(repo, false)
 	err = checker.LoadSnapshots(context.TODO())
 	if err != nil {

internal/repository/repack_test.go

@@ -62,7 +62,7 @@ func createRandomBlobs(t testing.TB, repo restic.Repository, blobs int, pData fl
 	}
 }
 
-func createRandomWrongBlob(t testing.TB, repo restic.Repository) {
+func createRandomWrongBlob(t testing.TB, repo restic.Repository) restic.BlobHandle {
 	length := randomSize(10*1024, 1024*1024) // 10KiB to 1MiB of data
 	buf := make([]byte, length)
 	rand.Read(buf)
@@ -80,6 +80,7 @@ func createRandomWrongBlob(t testing.TB, repo restic.Repository) {
 	if err := repo.Flush(context.Background()); err != nil {
 		t.Fatalf("repo.Flush() returned error %v", err)
 	}
+	return restic.BlobHandle{ID: id, Type: restic.DataBlob}
 }
 
 // selectBlobs splits the list of all blobs randomly into two lists. A blob
@@ -173,39 +174,27 @@ func flush(t *testing.T, repo restic.Repository) {
 
 func rebuildIndex(t *testing.T, repo restic.Repository) {
 	err := repo.SetIndex(index.NewMasterIndex())
-	if err != nil {
-		t.Fatal(err)
-	}
+	rtest.OK(t, err)
 
 	packs := make(map[restic.ID]int64)
 	err = repo.List(context.TODO(), restic.PackFile, func(id restic.ID, size int64) error {
 		packs[id] = size
 		return nil
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
+	rtest.OK(t, err)
 
 	_, err = repo.(*repository.Repository).CreateIndexFromPacks(context.TODO(), packs, nil)
-	if err != nil {
-		t.Fatal(err)
-	}
+	rtest.OK(t, err)
 
+	var obsoleteIndexes restic.IDs
 	err = repo.List(context.TODO(), restic.IndexFile, func(id restic.ID, size int64) error {
-		h := backend.Handle{
-			Type: restic.IndexFile,
-			Name: id.String(),
-		}
-		return repo.Backend().Remove(context.TODO(), h)
+		obsoleteIndexes = append(obsoleteIndexes, id)
+		return nil
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
+	rtest.OK(t, err)
 
-	_, err = repo.Index().Save(context.TODO(), repo, restic.NewIDSet(), nil, nil)
-	if err != nil {
-		t.Fatal(err)
-	}
+	err = repo.Index().Save(context.TODO(), repo, restic.NewIDSet(), obsoleteIndexes, restic.MasterIndexSaveOpts{})
+	rtest.OK(t, err)
 }
 
 func reloadIndex(t *testing.T, repo restic.Repository) {

internal/repository/repair_pack.go

@@ -0,0 +1,88 @@
+package repository
+
+import (
+	"context"
+	"errors"
+	"io"
+
+	"github.com/restic/restic/internal/restic"
+	"github.com/restic/restic/internal/ui/progress"
+	"golang.org/x/sync/errgroup"
+)
+
+func RepairPacks(ctx context.Context, repo restic.Repository, ids restic.IDSet, printer progress.Printer) error {
+	wg, wgCtx := errgroup.WithContext(ctx)
+	repo.StartPackUploader(wgCtx, wg)
+
+	printer.P("salvaging intact data from specified pack files")
+	bar := printer.NewCounter("pack files")
+	bar.SetMax(uint64(len(ids)))
+	defer bar.Done()
+
+	wg.Go(func() error {
+		// examine all data the indexes have for the pack file
+		for b := range repo.Index().ListPacks(wgCtx, ids) {
+			blobs := b.Blobs
+			if len(blobs) == 0 {
+				printer.E("no blobs found for pack %v", b.PackID)
+				bar.Add(1)
+				continue
+			}
+
+			err := repo.LoadBlobsFromPack(wgCtx, b.PackID, blobs, func(blob restic.BlobHandle, buf []byte, err error) error {
+				if err != nil {
+					// Fallback path
+					buf, err = repo.LoadBlob(wgCtx, blob.Type, blob.ID, nil)
+					if err != nil {
+						printer.E("failed to load blob %v: %v", blob.ID, err)
+						return nil
+					}
+				}
+				id, _, _, err := repo.SaveBlob(wgCtx, blob.Type, buf, restic.ID{}, true)
+				if !id.Equal(blob.ID) {
+					panic("pack id mismatch during upload")
+				}
+				return err
+			})
+			// ignore truncated file parts
+			if err != nil && !errors.Is(err, io.ErrUnexpectedEOF) {
+				return err
+			}
+			bar.Add(1)
+		}
+		return repo.Flush(wgCtx)
+	})
+
+	err := wg.Wait()
+	bar.Done()
+	if err != nil {
+		return err
+	}
+
+	// remove salvaged packs from index
+	printer.P("rebuilding index")
+
+	bar = printer.NewCounter("packs processed")
+	err = repo.Index().Save(ctx, repo, ids, nil, restic.MasterIndexSaveOpts{
+		SaveProgress: bar,
+		DeleteProgress: func() *progress.Counter {
+			return printer.NewCounter("old indexes deleted")
+		},
+		DeleteReport: func(id restic.ID, err error) {
+			printer.VV("removed index %v", id.String())
+		},
+	})
+
+	if err != nil {
+		return err
+	}
+
+	// cleanup
+	printer.P("removing salvaged pack files")
+	// if we fail to delete the damaged pack files, then prune will remove them later on
+	bar = printer.NewCounter("files deleted")
+	_ = restic.ParallelRemove(ctx, repo, ids, restic.PackFile, nil, bar)
+	bar.Done()
+
+	return nil
+}

internal/repository/repair_pack_test.go

@@ -0,0 +1,130 @@
+package repository_test
+
+import (
+	"context"
+	"math/rand"
+	"testing"
+	"time"
+
+	"github.com/restic/restic/internal/backend"
+	"github.com/restic/restic/internal/index"
+	"github.com/restic/restic/internal/repository"
+	"github.com/restic/restic/internal/restic"
+	"github.com/restic/restic/internal/test"
+	rtest "github.com/restic/restic/internal/test"
+	"github.com/restic/restic/internal/ui/progress"
+)
+
+func listBlobs(repo restic.Repository) restic.BlobSet {
+	blobs := restic.NewBlobSet()
+	repo.Index().Each(context.TODO(), func(pb restic.PackedBlob) {
+		blobs.Insert(pb.BlobHandle)
+	})
+	return blobs
+}
+
+func replaceFile(t *testing.T, repo restic.Repository, h backend.Handle, damage func([]byte) []byte) {
+	buf, err := backend.LoadAll(context.TODO(), nil, repo.Backend(), h)
+	test.OK(t, err)
+	buf = damage(buf)
+	test.OK(t, repo.Backend().Remove(context.TODO(), h))
+	test.OK(t, repo.Backend().Save(context.TODO(), h, backend.NewByteReader(buf, repo.Backend().Hasher())))
+}
+
+func TestRepairBrokenPack(t *testing.T) {
+	repository.TestAllVersions(t, testRepairBrokenPack)
+}
+
+func testRepairBrokenPack(t *testing.T, version uint) {
+	tests := []struct {
+		name   string
+		damage func(repo restic.Repository, packsBefore restic.IDSet) (restic.IDSet, restic.BlobSet)
+	}{
+		{
+			"valid pack",
+			func(repo restic.Repository, packsBefore restic.IDSet) (restic.IDSet, restic.BlobSet) {
+				return packsBefore, restic.NewBlobSet()
+			},
+		},
+		{
+			"broken pack",
+			func(repo restic.Repository, packsBefore restic.IDSet) (restic.IDSet, restic.BlobSet) {
+				wrongBlob := createRandomWrongBlob(t, repo)
+				damagedPacks := findPacksForBlobs(t, repo, restic.NewBlobSet(wrongBlob))
+				return damagedPacks, restic.NewBlobSet(wrongBlob)
+			},
+		},
+		{
+			"partially broken pack",
+			func(repo restic.Repository, packsBefore restic.IDSet) (restic.IDSet, restic.BlobSet) {
+				// damage one of the pack files
+				damagedID := packsBefore.List()[0]
+				replaceFile(t, repo, backend.Handle{Type: backend.PackFile, Name: damagedID.String()},
+					func(buf []byte) []byte {
+						buf[0] ^= 0xff
+						return buf
+					})
+
+				// find blob that starts at offset 0
+				var damagedBlob restic.BlobHandle
+				for blobs := range repo.Index().ListPacks(context.TODO(), restic.NewIDSet(damagedID)) {
+					for _, blob := range blobs.Blobs {
+						if blob.Offset == 0 {
+							damagedBlob = blob.BlobHandle
+						}
+					}
+				}
+
+				return restic.NewIDSet(damagedID), restic.NewBlobSet(damagedBlob)
+			},
+		}, {
+			"truncated pack",
+			func(repo restic.Repository, packsBefore restic.IDSet) (restic.IDSet, restic.BlobSet) {
+				// damage one of the pack files
+				damagedID := packsBefore.List()[0]
+				replaceFile(t, repo, backend.Handle{Type: backend.PackFile, Name: damagedID.String()},
+					func(buf []byte) []byte {
+						buf = buf[0:10]
+						return buf
+					})
+
+				// all blobs in the file are broken
+				damagedBlobs := restic.NewBlobSet()
+				for blobs := range repo.Index().ListPacks(context.TODO(), restic.NewIDSet(damagedID)) {
+					for _, blob := range blobs.Blobs {
+						damagedBlobs.Insert(blob.BlobHandle)
+					}
+				}
+				return restic.NewIDSet(damagedID), damagedBlobs
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			repo := repository.TestRepositoryWithVersion(t, version)
+
+			seed := time.Now().UnixNano()
+			rand.Seed(seed)
+			t.Logf("rand seed is %v", seed)
+
+			createRandomBlobs(t, repo, 5, 0.7)
+			packsBefore := listPacks(t, repo)
+			blobsBefore := listBlobs(repo)
+
+			toRepair, damagedBlobs := test.damage(repo, packsBefore)
+
+			rtest.OK(t, repository.RepairPacks(context.TODO(), repo, toRepair, &progress.NoopPrinter{}))
+			// reload index
+			rtest.OK(t, repo.SetIndex(index.NewMasterIndex()))
+			rtest.OK(t, repo.LoadIndex(context.TODO(), nil))
+
+			packsAfter := listPacks(t, repo)
+			blobsAfter := listBlobs(repo)
+
+			rtest.Assert(t, len(packsAfter.Intersect(toRepair)) == 0, "some damaged packs were not removed")
+			rtest.Assert(t, len(packsBefore.Sub(toRepair).Sub(packsAfter)) == 0, "not-damaged packs were removed")
+			rtest.Assert(t, blobsBefore.Sub(damagedBlobs).Equals(blobsAfter), "diverging blob lists")
+		})
+	}
+}

internal/repository/repository_test.go

@@ -28,10 +28,19 @@ var testSizes = []int{5, 23, 2<<18 + 23, 1 << 20}
 var rnd = rand.New(rand.NewSource(time.Now().UnixNano()))
 
 func TestSave(t *testing.T) {
-	repository.TestAllVersions(t, testSave)
+	repository.TestAllVersions(t, testSavePassID)
+	repository.TestAllVersions(t, testSaveCalculateID)
 }
 
-func testSave(t *testing.T, version uint) {
+func testSavePassID(t *testing.T, version uint) {
+	testSave(t, version, false)
+}
+
+func testSaveCalculateID(t *testing.T, version uint) {
+	testSave(t, version, true)
+}
+
+func testSave(t *testing.T, version uint, calculateID bool) {
 	repo := repository.TestRepositoryWithVersion(t, version)
 
 	for _, size := range testSizes {
@@ -45,51 +54,14 @@ func testSave(t *testing.T, version uint) {
 		repo.StartPackUploader(context.TODO(), &wg)
 
 		// save
-		sid, _, _, err := repo.SaveBlob(context.TODO(), restic.DataBlob, data, restic.ID{}, false)
+		inputID := restic.ID{}
+		if !calculateID {
+			inputID = id
+		}
+		sid, _, _, err := repo.SaveBlob(context.TODO(), restic.DataBlob, data, inputID, false)
 		rtest.OK(t, err)
-
 		rtest.Equals(t, id, sid)
 
-		rtest.OK(t, repo.Flush(context.Background()))
-		// rtest.OK(t, repo.SaveIndex())
-
-		// read back
-		buf, err := repo.LoadBlob(context.TODO(), restic.DataBlob, id, nil)
-		rtest.OK(t, err)
-		rtest.Equals(t, size, len(buf))
-
-		rtest.Assert(t, len(buf) == len(data),
-			"number of bytes read back does not match: expected %d, got %d",
-			len(data), len(buf))
-
-		rtest.Assert(t, bytes.Equal(buf, data),
-			"data does not match: expected %02x, got %02x",
-			data, buf)
-	}
-}
-
-func TestSaveFrom(t *testing.T) {
-	repository.TestAllVersions(t, testSaveFrom)
-}
-
-func testSaveFrom(t *testing.T, version uint) {
-	repo := repository.TestRepositoryWithVersion(t, version)
-
-	for _, size := range testSizes {
-		data := make([]byte, size)
-		_, err := io.ReadFull(rnd, data)
-		rtest.OK(t, err)
-
-		id := restic.Hash(data)
-
-		var wg errgroup.Group
-		repo.StartPackUploader(context.TODO(), &wg)
-
-		// save
-		id2, _, _, err := repo.SaveBlob(context.TODO(), restic.DataBlob, data, id, false)
-		rtest.OK(t, err)
-		rtest.Equals(t, id, id2)
-
 		rtest.OK(t, repo.Flush(context.Background()))
 
 		// read back

internal/restic/parallel.go

@@ -3,7 +3,9 @@ package restic
 import (
 	"context"
 
+	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/debug"
+	"github.com/restic/restic/internal/ui/progress"
 	"golang.org/x/sync/errgroup"
 )
 
@@ -50,3 +52,43 @@ func ParallelList(ctx context.Context, r Lister, t FileType, parallelism uint, f
 
 	return wg.Wait()
 }
+
+// ParallelRemove deletes the given fileList of fileType in parallel
+// if callback returns an error, then it will abort.
+func ParallelRemove(ctx context.Context, repo Repository, fileList IDSet, fileType FileType, report func(id ID, err error) error, bar *progress.Counter) error {
+	fileChan := make(chan ID)
+	wg, ctx := errgroup.WithContext(ctx)
+	wg.Go(func() error {
+		defer close(fileChan)
+		for id := range fileList {
+			select {
+			case fileChan <- id:
+			case <-ctx.Done():
+				return ctx.Err()
+			}
+		}
+		return nil
+	})
+
+	bar.SetMax(uint64(len(fileList)))
+
+	// deleting files is IO-bound
+	workerCount := repo.Connections()
+	for i := 0; i < int(workerCount); i++ {
+		wg.Go(func() error {
+			for id := range fileChan {
+				h := backend.Handle{Type: fileType, Name: id.String()}
+				err := repo.Backend().Remove(ctx, h)
+				if report != nil {
+					err = report(id, err)
+				}
+				if err != nil {
+					return err
+				}
+				bar.Add(1)
+			}
+			return nil
+		})
+	}
+	return wg.Wait()
+}

internal/restic/repository.go

@@ -89,6 +89,13 @@ type PackBlobs struct {
 	Blobs  []Blob
 }
 
+type MasterIndexSaveOpts struct {
+	SaveProgress   *progress.Counter
+	DeleteProgress func() *progress.Counter
+	DeleteReport   func(id ID, err error)
+	SkipDeletion   bool
+}
+
 // MasterIndex keeps track of the blobs are stored within files.
 type MasterIndex interface {
 	Has(BlobHandle) bool
@@ -99,7 +106,7 @@ type MasterIndex interface {
 	Each(ctx context.Context, fn func(PackedBlob))
 	ListPacks(ctx context.Context, packs IDSet) <-chan PackBlobs
 
-	Save(ctx context.Context, repo SaverUnpacked, packBlacklist IDSet, extraObsolete IDs, p *progress.Counter) (obsolete IDSet, err error)
+	Save(ctx context.Context, repo Repository, excludePacks IDSet, extraObsolete IDs, opts MasterIndexSaveOpts) error
 }
 
 // Lister allows listing files in a backend.

internal/ui/progress/printer.go

@@ -0,0 +1,30 @@
+package progress
+
+// A Printer can can return a new counter or print messages
+// at different log levels.
+// It must be safe to call its methods from concurrent goroutines.
+type Printer interface {
+	NewCounter(description string) *Counter
+
+	E(msg string, args ...interface{})
+	P(msg string, args ...interface{})
+	V(msg string, args ...interface{})
+	VV(msg string, args ...interface{})
+}
+
+// NoopPrinter discards all messages
+type NoopPrinter struct{}
+
+var _ Printer = (*NoopPrinter)(nil)
+
+func (*NoopPrinter) NewCounter(_ string) *Counter {
+	return nil
+}
+
+func (*NoopPrinter) E(_ string, _ ...interface{}) {}
+
+func (*NoopPrinter) P(_ string, _ ...interface{}) {}
+
+func (*NoopPrinter) V(_ string, _ ...interface{}) {}
+
+func (*NoopPrinter) VV(_ string, _ ...interface{}) {}