/** Turn the block identifier into a filename. */
public synchronized File getFile(Block b) {
DatanodeBlockInfo info = volumeMap.get(b);
if (info != null) {
return info.getFile();
}
return null;
}
/**
* Make a copy of the block if this block is linked to an existing snapshot. This ensures that
* modifying this block does not modify data in any existing snapshots.
*
* @param block Block
* @param numLinks Detach if the number of links exceed this value
* @throws IOException
* @return - true if the specified block was detached
*/
public boolean detachBlock(Block block, int numLinks) throws IOException {
DatanodeBlockInfo info = null;
synchronized (this) {
info = volumeMap.get(block);
}
return info.detachBlock(block, numLinks);
}
/** {@inheritDoc} */
public void validateBlockMetadata(Block b) throws IOException {
DatanodeBlockInfo info = volumeMap.get(b);
if (info == null) {
throw new IOException("Block " + b + " does not exist in volumeMap.");
}
FSVolume v = info.getVolume();
File tmp = v.getTmpFile(b);
File f = getFile(b);
if (f == null) {
f = tmp;
}
if (f == null) {
throw new IOException("Block " + b + " does not exist on disk.");
}
if (!f.exists()) {
throw new IOException("Block " + b + " block file " + f + " does not exist on disk.");
}
if (b.getNumBytes() != f.length()) {
throw new IOException(
"Block "
+ b
+ " length is "
+ b.getNumBytes()
+ " does not match block file length "
+ f.length());
}
File meta = getMetaFile(f, b);
if (meta == null) {
throw new IOException("Block " + b + " metafile does not exist.");
}
if (!meta.exists()) {
throw new IOException("Block " + b + " metafile " + meta + " does not exist on disk.");
}
if (meta.length() == 0) {
throw new IOException("Block " + b + " metafile " + meta + " is empty.");
}
long stamp = parseGenerationStamp(f, meta);
if (stamp != b.getGenerationStamp()) {
throw new IOException(
"Block "
+ b
+ " genstamp is "
+ b.getGenerationStamp()
+ " does not match meta file stamp "
+ stamp);
}
}
/** Returns handles to the block file and its metadata file */
public synchronized BlockInputStreams getTmpInputStreams(Block b, long blkOffset, long ckoff)
throws IOException {
DatanodeBlockInfo info = volumeMap.get(b);
if (info == null) {
throw new IOException("Block " + b + " does not exist in volumeMap.");
}
FSVolume v = info.getVolume();
File blockFile = v.getTmpFile(b);
RandomAccessFile blockInFile = new RandomAccessFile(blockFile, "r");
if (blkOffset > 0) {
blockInFile.seek(blkOffset);
}
File metaFile = getMetaFile(blockFile, b);
RandomAccessFile metaInFile = new RandomAccessFile(metaFile, "r");
if (ckoff > 0) {
metaInFile.seek(ckoff);
}
return new BlockInputStreams(
new FileInputStream(blockInFile.getFD()), new FileInputStream(metaInFile.getFD()));
}
/**
* We're informed that a block is no longer valid. We could lazily garbage-collect the block, but
* why bother? just get rid of it.
*/
public void invalidate(Block invalidBlks[]) throws IOException {
boolean error = false;
for (int i = 0; i < invalidBlks.length; i++) {
File f = null;
FSVolume v;
synchronized (this) {
f = getFile(invalidBlks[i]);
DatanodeBlockInfo dinfo = volumeMap.get(invalidBlks[i]);
if (dinfo == null) {
DataNode.LOG.warn(
"Unexpected error trying to delete block "
+ invalidBlks[i]
+ ". BlockInfo not found in volumeMap.");
error = true;
continue;
}
v = dinfo.getVolume();
if (f == null) {
DataNode.LOG.warn(
"Unexpected error trying to delete block "
+ invalidBlks[i]
+ ". Block not found in blockMap."
+ ((v == null) ? " " : " Block found in volumeMap."));
error = true;
continue;
}
if (v == null) {
DataNode.LOG.warn(
"Unexpected error trying to delete block "
+ invalidBlks[i]
+ ". No volume for this block."
+ " Block found in blockMap. "
+ f
+ ".");
error = true;
continue;
}
File parent = f.getParentFile();
if (parent == null) {
DataNode.LOG.warn(
"Unexpected error trying to delete block "
+ invalidBlks[i]
+ ". Parent not found for file "
+ f
+ ".");
error = true;
continue;
}
v.clearPath(parent);
volumeMap.remove(invalidBlks[i]);
}
File metaFile = getMetaFile(f, invalidBlks[i]);
long blockSize = f.length() + metaFile.length();
if (!f.delete() || (!metaFile.delete() && metaFile.exists())) {
DataNode.LOG.warn(
"Unexpected error trying to delete block " + invalidBlks[i] + " at file " + f);
error = true;
continue;
}
v.decDfsUsed(blockSize);
DataNode.LOG.info("Deleting block " + invalidBlks[i] + " file " + f);
if (f.exists()) {
//
// This is a temporary check especially for hadoop-1220.
// This will go away in the future.
//
DataNode.LOG.info("File " + f + " was deleted but still exists!");
}
}
if (error) {
throw new IOException("Error in deleting blocks.");
}
}