private static void truncateBlock(File blockFile, File metaFile, long oldlen, long newlen)
throws IOException {
if (newlen == oldlen) {
return;
}
if (newlen > oldlen) {
throw new IOException(
"Cannout truncate block to from oldlen (=" + oldlen + ") to newlen (=" + newlen + ")");
}
DataChecksum dcs = BlockMetadataHeader.readHeader(metaFile).getChecksum();
int checksumsize = dcs.getChecksumSize();
int bpc = dcs.getBytesPerChecksum();
long n = (newlen - 1) / bpc + 1;
long newmetalen = BlockMetadataHeader.getHeaderSize() + n * checksumsize;
long lastchunkoffset = (n - 1) * bpc;
int lastchunksize = (int) (newlen - lastchunkoffset);
byte[] b = new byte[Math.max(lastchunksize, checksumsize)];
RandomAccessFile blockRAF = new RandomAccessFile(blockFile, "rw");
try {
// truncate blockFile
blockRAF.setLength(newlen);
// read last chunk
blockRAF.seek(lastchunkoffset);
blockRAF.readFully(b, 0, lastchunksize);
} finally {
blockRAF.close();
}
// compute checksum
dcs.update(b, 0, lastchunksize);
dcs.writeValue(b, 0, false);
// update metaFile
RandomAccessFile metaRAF = new RandomAccessFile(metaFile, "rw");
try {
metaRAF.setLength(newmetalen);
metaRAF.seek(newmetalen - checksumsize);
metaRAF.write(b, 0, checksumsize);
} finally {
metaRAF.close();
}
}
public void testGetMetaData() throws IOException {
final SimulatedFSDataset fsdataset = getSimulatedFSDataset();
ExtendedBlock b = new ExtendedBlock(bpid, 1, 5, 0);
try {
assertTrue(fsdataset.getMetaDataInputStream(b) == null);
assertTrue("Expected an IO exception", false);
} catch (IOException e) {
// ok - as expected
}
addSomeBlocks(fsdataset); // Only need to add one but ....
b = new ExtendedBlock(bpid, 1, 0, 0);
InputStream metaInput = fsdataset.getMetaDataInputStream(b);
DataInputStream metaDataInput = new DataInputStream(metaInput);
short version = metaDataInput.readShort();
assertEquals(BlockMetadataHeader.VERSION, version);
DataChecksum checksum = DataChecksum.newDataChecksum(metaDataInput);
assertEquals(DataChecksum.CHECKSUM_NULL, checksum.getChecksumType());
assertEquals(0, checksum.getChecksumSize());
}
/**
* Find out the number of bytes in the block that match its crc.
*
* <p>This algorithm assumes that data corruption caused by unexpected datanode shutdown occurs
* only in the last crc chunk. So it checks only the last chunk.
*
* @param blockFile the block file
* @param genStamp generation stamp of the block
* @return the number of valid bytes
*/
private long validateIntegrityAndSetLength(File blockFile, long genStamp) {
DataInputStream checksumIn = null;
InputStream blockIn = null;
try {
final File metaFile = FsDatasetUtil.getMetaFile(blockFile, genStamp);
long blockFileLen = blockFile.length();
long metaFileLen = metaFile.length();
int crcHeaderLen = DataChecksum.getChecksumHeaderSize();
if (!blockFile.exists()
|| blockFileLen == 0
|| !metaFile.exists()
|| metaFileLen < crcHeaderLen) {
return 0;
}
checksumIn =
new DataInputStream(
new BufferedInputStream(
new FileInputStream(metaFile), HdfsConstants.IO_FILE_BUFFER_SIZE));
// read and handle the common header here. For now just a version
final DataChecksum checksum = BlockMetadataHeader.readDataChecksum(checksumIn, metaFile);
int bytesPerChecksum = checksum.getBytesPerChecksum();
int checksumSize = checksum.getChecksumSize();
long numChunks =
Math.min(
(blockFileLen + bytesPerChecksum - 1) / bytesPerChecksum,
(metaFileLen - crcHeaderLen) / checksumSize);
if (numChunks == 0) {
return 0;
}
IOUtils.skipFully(checksumIn, (numChunks - 1) * checksumSize);
blockIn = new FileInputStream(blockFile);
long lastChunkStartPos = (numChunks - 1) * bytesPerChecksum;
IOUtils.skipFully(blockIn, lastChunkStartPos);
int lastChunkSize = (int) Math.min(bytesPerChecksum, blockFileLen - lastChunkStartPos);
byte[] buf = new byte[lastChunkSize + checksumSize];
checksumIn.readFully(buf, lastChunkSize, checksumSize);
IOUtils.readFully(blockIn, buf, 0, lastChunkSize);
checksum.update(buf, 0, lastChunkSize);
long validFileLength;
if (checksum.compare(buf, lastChunkSize)) { // last chunk matches crc
validFileLength = lastChunkStartPos + lastChunkSize;
} else { // last chunck is corrupt
validFileLength = lastChunkStartPos;
}
// truncate if extra bytes are present without CRC
if (blockFile.length() > validFileLength) {
RandomAccessFile blockRAF = new RandomAccessFile(blockFile, "rw");
try {
// truncate blockFile
blockRAF.setLength(validFileLength);
} finally {
blockRAF.close();
}
}
return validFileLength;
} catch (IOException e) {
FsDatasetImpl.LOG.warn(e);
return 0;
} finally {
IOUtils.closeStream(checksumIn);
IOUtils.closeStream(blockIn);
}
}
BlockSender(
Block block,
long startOffset,
long length,
boolean corruptChecksumOk,
boolean chunkOffsetOK,
boolean verifyChecksum,
DataNode datanode,
String clientTraceFmt)
throws IOException {
try {
this.block = block;
synchronized (datanode.data) {
this.replica = datanode.data.getReplica(block.getBlockId());
if (replica == null) {
throw new ReplicaNotFoundException(block);
}
this.replicaVisibleLength = replica.getVisibleLength();
}
long minEndOffset = startOffset + length;
// if this is a write in progress
ChunkChecksum chunkChecksum = null;
if (replica instanceof ReplicaBeingWritten) {
for (int i = 0; i < 30 && replica.getBytesOnDisk() < minEndOffset; i++) {
try {
Thread.sleep(100);
} catch (InterruptedException ie) {
throw new IOException(ie);
}
}
long currentBytesOnDisk = replica.getBytesOnDisk();
if (currentBytesOnDisk < minEndOffset) {
throw new IOException(
String.format(
"need %d bytes, but only %d bytes available", minEndOffset, currentBytesOnDisk));
}
ReplicaInPipeline rip = (ReplicaInPipeline) replica;
chunkChecksum = rip.getLastChecksumAndDataLen();
}
if (replica.getGenerationStamp() < block.getGenerationStamp()) {
throw new IOException(
"replica.getGenerationStamp() < block.getGenerationStamp(), block="
+ block
+ ", replica="
+ replica);
}
if (replicaVisibleLength < 0) {
throw new IOException(
"The replica is not readable, block=" + block + ", replica=" + replica);
}
if (DataNode.LOG.isDebugEnabled()) {
DataNode.LOG.debug("block=" + block + ", replica=" + replica);
}
this.chunkOffsetOK = chunkOffsetOK;
this.corruptChecksumOk = corruptChecksumOk;
this.verifyChecksum = verifyChecksum;
// transferToFully() fails on 32 bit platforms for block sizes >= 2GB,
// use normal transfer in those cases
this.transferToAllowed =
datanode.transferToAllowed && (!is32Bit || length < (long) Integer.MAX_VALUE);
this.clientTraceFmt = clientTraceFmt;
if (!corruptChecksumOk || datanode.data.metaFileExists(block)) {
checksumIn =
new DataInputStream(
new BufferedInputStream(datanode.data.getMetaDataInputStream(block), BUFFER_SIZE));
// read and handle the common header here. For now just a version
BlockMetadataHeader header = BlockMetadataHeader.readHeader(checksumIn);
short version = header.getVersion();
if (version != FSDataset.METADATA_VERSION) {
LOG.warn(
"Wrong version (" + version + ") for metadata file for " + block + " ignoring ...");
}
checksum = header.getChecksum();
} else {
LOG.warn("Could not find metadata file for " + block);
// This only decides the buffer size. Use BUFFER_SIZE?
checksum = DataChecksum.newDataChecksum(DataChecksum.CHECKSUM_NULL, 16 * 1024);
}
/* If bytesPerChecksum is very large, then the metadata file
* is mostly corrupted. For now just truncate bytesPerchecksum to
* blockLength.
*/
bytesPerChecksum = checksum.getBytesPerChecksum();
if (bytesPerChecksum > 10 * 1024 * 1024 && bytesPerChecksum > replicaVisibleLength) {
checksum =
DataChecksum.newDataChecksum(
checksum.getChecksumType(), Math.max((int) replicaVisibleLength, 10 * 1024 * 1024));
bytesPerChecksum = checksum.getBytesPerChecksum();
}
checksumSize = checksum.getChecksumSize();
if (length < 0) {
length = replicaVisibleLength;
}
// end is either last byte on disk or the length for which we have a
// checksum
if (chunkChecksum != null) {
endOffset = chunkChecksum.getDataLength();
} else {
endOffset = replica.getBytesOnDisk();
}
if (startOffset < 0 || startOffset > endOffset || (length + startOffset) > endOffset) {
String msg =
" Offset "
+ startOffset
+ " and length "
+ length
+ " don't match block "
+ block
+ " ( blockLen "
+ endOffset
+ " )";
LOG.warn(datanode.dnRegistration + ":sendBlock() : " + msg);
throw new IOException(msg);
}
offset = (startOffset - (startOffset % bytesPerChecksum));
if (length >= 0) {
// Make sure endOffset points to end of a checksumed chunk.
long tmpLen = startOffset + length;
if (tmpLen % bytesPerChecksum != 0) {
tmpLen += (bytesPerChecksum - tmpLen % bytesPerChecksum);
}
if (tmpLen < endOffset) {
// will use on-disk checksum here since the end is a stable chunk
endOffset = tmpLen;
} else if (chunkChecksum != null) {
// in last chunk which is changing. flag that we need to use in-memory
// checksum
this.lastChunkChecksum = chunkChecksum;
}
}
// seek to the right offsets
if (offset > 0) {
long checksumSkip = (offset / bytesPerChecksum) * checksumSize;
// note blockInStream is seeked when created below
if (checksumSkip > 0) {
// Should we use seek() for checksum file as well?
IOUtils.skipFully(checksumIn, checksumSkip);
}
}
seqno = 0;
if (DataNode.LOG.isDebugEnabled()) {
DataNode.LOG.debug("replica=" + replica);
}
blockIn = datanode.data.getBlockInputStream(block, offset); // seek to offset
} catch (IOException ioe) {
IOUtils.closeStream(this);
IOUtils.closeStream(blockIn);
throw ioe;
}
}
