feat(store): correct corrupted files on write

store/file/ods.go

@@ -131,6 +131,27 @@ func writeAxisRoots(w io.Writer, roots *share.AxisRoots) error {
 	return nil
 }
 
+// ValidateODSSize checks if the file under given FS path has the expected size.
+func ValidateODSSize(path string, eds *rsmt2d.ExtendedDataSquare) error {
+	ods, err := OpenODS(path)
+	if err != nil {
+		return fmt.Errorf("opening file: %w", err)
+	}
+
+	shares := filledSharesAmount(eds)
+	shareSize := len(eds.GetCell(0, 0))
+	expectedSize := ods.hdr.OffsetWithRoots() + shares*shareSize
+
+	info, err := ods.fl.Stat()
+	if err != nil {
+		return fmt.Errorf("getting file info: %w", err)
+	}
+	if info.Size() != int64(expectedSize) {
+		return fmt.Errorf("file size mismatch: expected %d, got %d", expectedSize, info.Size())
+	}
+	return nil
+}
+
 // OpenODS opens an existing ODS file under given FS path.
 // It only reads the header with metadata. The other content
 // of the File is read lazily.
@@ -414,3 +435,18 @@ func readColHalf(r io.ReaderAt, colIdx int, hdr *headerV0, offset int) ([]share.
 	}
 	return shares, nil
 }
+
+// filledSharesAmount returns the amount of shares in the ODS that are not tail padding.
+func filledSharesAmount(eds *rsmt2d.ExtendedDataSquare) int {
+	var amount int
+	for i := range eds.Width() / 2 {
+		for j := range eds.Width() / 2 {
+			shr := eds.GetCell(i, j)
+			if share.GetNamespace(shr).Equals(share.TailPaddingNamespace) {
+				break
+			}
+			amount++
+		}
+	}
+	return amount
+}

store/file/ods_q4.go

@@ -61,6 +61,19 @@ func CreateODSQ4(
 	return nil
 }
 
+// ValidateODSQ4Size checks the size of the ODS and Q4 files under the given FS paths.
+func ValidateODSQ4Size(pathODS, pathQ4 string, eds *rsmt2d.ExtendedDataSquare) error {
+	err := ValidateODSSize(pathODS, eds)
+	if err != nil {
+		return fmt.Errorf("validating ODS file size: %w", err)
+	}
+	err = validateQ4Size(pathQ4, eds)
+	if err != nil {
+		return fmt.Errorf("validating Q4 file size: %w", err)
+	}
+	return nil
+}
+
 // ODSWithQ4 returns ODSQ4 instance over ODS. It opens Q4 file lazily under the given path.
 func ODSWithQ4(ods *ODS, pathQ4 string) *ODSQ4 {
 	return &ODSQ4{

store/file/ods_q4_test.go

@@ -2,6 +2,9 @@ package file
 
 import (
 	"context"
+	"fmt"
+	"io"
+	"os"
 	"strconv"
 	"testing"
 	"time"
@@ -39,6 +42,95 @@ func TestODSQ4File(t *testing.T) {
 	eds.TestStreamer(ctx, t, createODSQ4AccessorStreamer, ODSSize)
 }
 
+func TestValidateODSQ4FileSize(t *testing.T) {
+	edses := []struct {
+		name string
+		eds  *rsmt2d.ExtendedDataSquare
+	}{
+		{
+			name: "no padding",
+			eds:  edstest.RandEDS(t, 8),
+		},
+		{
+			name: "with padding",
+			eds:  edstest.RandEDSWithTailPadding(t, 8, 11),
+		},
+		{
+			name: "empty", eds: share.EmptyEDS(),
+		},
+	}
+
+	tests := []struct {
+		name       string
+		createFile func(pathODS, pathQ4 string, roots *share.AxisRoots, eds *rsmt2d.ExtendedDataSquare) error
+		valid      bool
+	}{
+		{
+			name:       "valid",
+			createFile: CreateODSQ4,
+			valid:      true,
+		},
+		{
+			name: "shorter q4",
+			createFile: func(pathODS, pathQ4 string, roots *share.AxisRoots, eds *rsmt2d.ExtendedDataSquare) error {
+				err := CreateODSQ4(pathODS, pathQ4, roots, eds)
+				if err != nil {
+					return err
+				}
+				file, err := os.OpenFile(pathQ4, os.O_RDWR, 0)
+				if err != nil {
+					return err
+				}
+				defer file.Close()
+				info, err := file.Stat()
+				if err != nil {
+					return err
+				}
+				return file.Truncate(info.Size() - 1)
+			},
+			valid: false,
+		},
+		{
+			name: "longer q4",
+			createFile: func(pathODS, pathQ4 string, roots *share.AxisRoots, eds *rsmt2d.ExtendedDataSquare) error {
+				err := CreateODSQ4(pathODS, pathQ4, roots, eds)
+				if err != nil {
+					return err
+				}
+				file, err := os.OpenFile(pathQ4, os.O_RDWR, 0)
+				if err != nil {
+					return err
+				}
+				defer file.Close()
+				// append 1 byte to the file
+				_, err = file.Seek(0, io.SeekEnd)
+				if err != nil {
+					return err
+				}
+				_, err = file.Write([]byte{0})
+				return err
+			},
+			valid: false,
+		},
+	}
+
+	for _, tt := range tests {
+		for _, eds := range edses {
+			t.Run(fmt.Sprintf("%s/%s", tt.name, eds.name), func(t *testing.T) {
+				pathODS := t.TempDir() + tt.name + eds.name
+				pathQ4 := pathODS + ".q4"
+				roots, err := share.NewAxisRoots(eds.eds)
+				require.NoError(t, err)
+				err = tt.createFile(pathODS, pathQ4, roots, eds.eds)
+				require.NoError(t, err)
+
+				err = ValidateODSQ4Size(pathODS, pathQ4, eds.eds)
+				require.Equal(t, tt.valid, err == nil)
+			})
+		}
+	}
+}
+
 // BenchmarkAxisFromODSQ4File/Size:32/ProofType:row/squareHalf:0-16         	  354836	      3345 ns/op
 // BenchmarkAxisFromODSQ4File/Size:32/ProofType:row/squareHalf:1-16         	  339547	      3187 ns/op
 // BenchmarkAxisFromODSQ4File/Size:32/ProofType:col/squareHalf:0-16         	   69364	     16440 ns/op

store/file/ods_test.go

@@ -2,6 +2,9 @@ package file
 
 import (
 	"context"
+	"fmt"
+	"io"
+	"os"
 	"strconv"
 	"testing"
 	"time"
@@ -61,6 +64,94 @@ func TestODSFile(t *testing.T) {
 	eds.TestStreamer(ctx, t, createODSAccessorStreamer, ODSSize)
 }
 
+func TestValidateODSSize(t *testing.T) {
+	edses := []struct {
+		name string
+		eds  *rsmt2d.ExtendedDataSquare
+	}{
+		{
+			name: "no padding",
+			eds:  edstest.RandEDS(t, 8),
+		},
+		{
+			name: "with padding",
+			eds:  edstest.RandEDSWithTailPadding(t, 8, 11),
+		},
+		{
+			name: "empty", eds: share.EmptyEDS(),
+		},
+	}
+
+	tests := []struct {
+		name       string
+		createFile func(path string, roots *share.AxisRoots, eds *rsmt2d.ExtendedDataSquare) error
+		valid      bool
+	}{
+		{
+			name:       "valid",
+			createFile: CreateODS,
+			valid:      true,
+		},
+		{
+			name: "shorter",
+			createFile: func(path string, roots *share.AxisRoots, eds *rsmt2d.ExtendedDataSquare) error {
+				err := CreateODS(path, roots, eds)
+				if err != nil {
+					return err
+				}
+				file, err := os.OpenFile(path, os.O_RDWR, 0)
+				if err != nil {
+					return err
+				}
+				defer file.Close()
+				info, err := file.Stat()
+				if err != nil {
+					return err
+				}
+				return file.Truncate(info.Size() - 1)
+			},
+			valid: false,
+		},
+		{
+			name: "longer",
+			createFile: func(path string, roots *share.AxisRoots, eds *rsmt2d.ExtendedDataSquare) error {
+				err := CreateODS(path, roots, eds)
+				if err != nil {
+					return err
+				}
+				file, err := os.OpenFile(path, os.O_RDWR, 0)
+				if err != nil {
+					return err
+				}
+				defer file.Close()
+				// append 1 byte to the file
+				_, err = file.Seek(0, io.SeekEnd)
+				if err != nil {
+					return err
+				}
+				_, err = file.Write([]byte{0})
+				return err
+			},
+			valid: false,
+		},
+	}
+
+	for _, tt := range tests {
+		for _, eds := range edses {
+			t.Run(fmt.Sprintf("%s/%s", tt.name, eds.name), func(t *testing.T) {
+				path := t.TempDir() + tt.name + eds.name
+				roots, err := share.NewAxisRoots(eds.eds)
+				require.NoError(t, err)
+				err = tt.createFile(path, roots, eds.eds)
+				require.NoError(t, err)
+
+				err = ValidateODSSize(path, eds.eds)
+				require.Equal(t, tt.valid, err == nil)
+			})
+		}
+	}
+}
+
 // BenchmarkAxisFromODSFile/Size:32/ProofType:row/squareHalf:0-16         	  382011	      3104 ns/op
 // BenchmarkAxisFromODSFile/Size:32/ProofType:row/squareHalf:1-16         	    9320	    122408 ns/op
 // BenchmarkAxisFromODSFile/Size:32/ProofType:col/squareHalf:0-16         	 4408911	       266.5 ns/op

store/file/q4.go

@@ -71,6 +71,27 @@ func writeQ4(w io.Writer, eds *rsmt2d.ExtendedDataSquare) error {
 	return nil
 }
 
+func validateQ4Size(path string, eds *rsmt2d.ExtendedDataSquare) error {
+	f, err := os.Open(path)
+	if err != nil {
+		return fmt.Errorf("opening file: %w", err)
+	}
+	defer f.Close()
+
+	odsSize := int(eds.Width() / 2)
+	shareSize := len(eds.GetCell(0, 0))
+	expectedSize := shareSize * odsSize * odsSize
+
+	info, err := f.Stat()
+	if err != nil {
+		return fmt.Errorf("getting file info: %w", err)
+	}
+	if info.Size() != int64(expectedSize) {
+		return fmt.Errorf("file size mismatch: expected %d, got %d", expectedSize, info.Size())
+	}
+	return nil
+}
+
 // openQ4 opens an existing Q4 file under given FS path.
 func openQ4(path string, hdr *headerV0) (*q4, error) {
 	f, err := os.Open(path)

store/store.go

@@ -181,6 +181,14 @@ func (s *Store) createODSQ4File(
 		)
 	}
 
+	// if file already exists, check if it's corrupted
+	if errors.Is(err, os.ErrExist) {
+		err = s.validateAndRecoverODSQ4(square, roots, height, pathODS, pathQ4)
+		if err != nil {
+			return false, err
+		}
+	}
+
 	// create hard link with height as name
 	err = s.linkHeight(roots.Hash(), height)
 	// if both file and link exist, we consider it as success
@@ -198,6 +206,29 @@ func (s *Store) createODSQ4File(
 	return false, nil
 }
 
+func (s *Store) validateAndRecoverODSQ4(
+	square *rsmt2d.ExtendedDataSquare,
+	roots *share.AxisRoots,
+	height uint64,
+	pathODS, pathQ4 string,
+) error {
+	// Validate the size of the file to ensure it's not corrupted
+	err := file.ValidateODSQ4Size(pathODS, pathQ4, square)
+	if err == nil {
+		return nil
+	}
+	log.Warnf("ODSQ4 file with height %d is corrupted, recovering", height)
+	err = s.removeODSQ4(height, roots.Hash())
+	if err != nil {
+		return fmt.Errorf("removing corrupted ODSQ4 file: %w", err)
+	}
+	err = file.CreateODSQ4(pathODS, pathQ4, roots, square)
+	if err != nil {
+		return fmt.Errorf("recreating ODSQ4 file: %w", err)
+	}
+	return nil
+}
+
 func (s *Store) createODSFile(
 	square *rsmt2d.ExtendedDataSquare,
 	roots *share.AxisRoots,
@@ -214,6 +245,15 @@ func (s *Store) createODSFile(
 		)
 	}
 
+	// if file already exists, check if it's corrupted
+	if errors.Is(err, os.ErrExist) {
+		// Validate the size of the file to ensure it's not corrupted
+		err = s.validateAndRecoverODS(square, roots, height, pathODS)
+		if err != nil {
+			return false, err
+		}
+	}
+
 	// create hard link with height as name
 	err = s.linkHeight(roots.Hash(), height)
 	// if both file and link exist, we consider it as success
@@ -231,6 +271,29 @@ func (s *Store) createODSFile(
 	return false, nil
 }
 
+func (s *Store) validateAndRecoverODS(
+	square *rsmt2d.ExtendedDataSquare,
+	roots *share.AxisRoots,
+	height uint64,
+	pathODS string,
+) error {
+	// Validate the size of the file to ensure it's not corrupted
+	err := file.ValidateODSSize(pathODS, square)
+	if err == nil {
+		return nil
+	}
+	log.Warnf("ODS file with height %d is corrupted, recovering", height)
+	err = s.removeODS(height, roots.Hash())
+	if err != nil {
+		return fmt.Errorf("removing corrupted ODS file: %w", err)
+	}
+	err = file.CreateODS(pathODS, roots, square)
+	if err != nil {
+		return fmt.Errorf("recreating ODS file: %w", err)
+	}
+	return nil
+}
+
 func (s *Store) linkHeight(datahash share.DataHash, height uint64) error {
 	linktoOds := s.heightToPath(height, odsFileExt)
 	if datahash.IsEmptyEDS() {