if algo != HighwayHash256S {
		return size
	}
	return ceilFrac(size, shardSize)*int64(algo.New().Size()) + size
}

// bitrotVerify a single stream of data.
func bitrotVerify(r io.Reader, wantSize, partSize int64, algo BitrotAlgorithm, want []byte, shardSize int64) error {
	if algo != HighwayHash256S {
		h := algo.New()

	// Check if VerifyFile reports the incorrect file length (the correct length is `size+1`)
	if err := storage.storage.bitrotVerify(context.Background(), pathJoin(path, volName, fileName), size, algo, hashBytes, 0); err == nil {
		t.Fatal("expected to fail bitrot check")
	}

	// Check if bitrot fails
	if err := storage.storage.bitrotVerify(context.Background(), pathJoin(path, volName, fileName), size+1, algo, hashBytes, 0); err == nil {

			continue
		}

		// Always check data, if we got it.
		if (len(meta.Data) > 0 || meta.Size == 0) && len(meta.Parts) > 0 {
			checksumInfo := meta.Erasure.GetChecksumInfo(meta.Parts[0].Number)
			verifyErr := bitrotVerify(bytes.NewReader(meta.Data),
				int64(len(meta.Data)),
				meta.Erasure.ShardFileSize(meta.Size),
				checksumInfo.Algorithm,
				checksumInfo.Hash, meta.Erasure.ShardSize())

	}

	// Remove parent dir of the source file if empty
	parentDir := pathutil.Dir(srcFilePath)
	s.deleteFile(srcVolumeDir, parentDir, false, false)

	return nil
}

func (s *xlStorage) bitrotVerify(ctx context.Context, partPath string, partSize int64, algo BitrotAlgorithm, sum []byte, shardSize int64) error {
	// Open the file for reading.
	file, err := OpenFile(partPath, readMode, 0o666)
	if err != nil {