Snap for 7963886 from 43752295 to sc-v2-release

    int num_ops = 0;

    int total_blocks_merged = 0;

    // This memcpy is important as metadata_buffer_ will be an unaligned address and will fault

    // on 32-bit systems

    std::unique_ptr<uint8_t[]> metadata_buffer =

            std::make_unique<uint8_t[]>(snapuserd_->GetBufferMetadataSize());

    memcpy(metadata_buffer.get(), metadata_buffer_, snapuserd_->GetBufferMetadataSize());

    while (true) {

        struct ScratchMetadata* bm = reinterpret_cast<struct ScratchMetadata*>(

                (char*)metadata_buffer_ + metadata_offset);

                (char*)metadata_buffer.get() + metadata_offset);

        // Done reading metadata

        if (bm->new_block == 0 && bm->file_offset == 0) {