Merge "Corrupt the PersistentDataBlock payload explicitly in factory reset" am: af5c516b

import libcore.io.IoUtils;

import java.io.DataInputStream;

import java.io.DataOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.RandomAccessFile;

import java.nio.ByteBuffer;

        try {

            FileChannel channel = getBlockOutputChannel();

            ByteBuffer buf = ByteBuffer.allocate(DIGEST_SIZE_BYTES + HEADER_SIZE);

            int header_size = DIGEST_SIZE_BYTES + HEADER_SIZE;

            ByteBuffer buf = ByteBuffer.allocate(header_size);

            buf.put(new byte[DIGEST_SIZE_BYTES]);

            buf.putInt(PARTITION_TYPE_MARKER);

            buf.putInt(0);

            channel.write(buf);

            // corrupt the payload explicitly

            int payload_size = (int) getBlockDeviceSize() - header_size;

            buf = ByteBuffer.allocate(payload_size);

            channel.write(buf);

            channel.force(true);

        } catch (IOException e) {

            Slog.e(TAG, "failed to format block", e);