/**
* Load one storage directory. Recover from previous transitions if required.
*
* @param datanode datanode instance
* @param nsInfo namespace information
* @param dataDir the root path of the storage directory
* @param startOpt startup option
* @return the StorageDirectory successfully loaded.
* @throws IOException
*/
private StorageDirectory loadStorageDirectory(
DataNode datanode, NamespaceInfo nsInfo, File dataDir, StartupOption startOpt)
throws IOException {
StorageDirectory sd = new StorageDirectory(dataDir, null, true);
try {
StorageState curState = sd.analyzeStorage(startOpt, this);
// sd is locked but not opened
switch (curState) {
case NORMAL:
break;
case NON_EXISTENT:
LOG.info("Block pool storage directory " + dataDir + " does not exist");
throw new IOException("Storage directory " + dataDir + " does not exist");
case NOT_FORMATTED: // format
LOG.info(
"Block pool storage directory "
+ dataDir
+ " is not formatted for "
+ nsInfo.getBlockPoolID());
LOG.info("Formatting ...");
format(sd, nsInfo);
break;
default: // recovery part is common
sd.doRecover(curState);
}
// 2. Do transitions
// Each storage directory is treated individually.
// During startup some of them can upgrade or roll back
// while others could be up-to-date for the regular startup.
doTransition(datanode, sd, nsInfo, startOpt);
if (getCTime() != nsInfo.getCTime()) {
throw new IOException("Data-node and name-node CTimes must be the same.");
}
// 3. Update successfully loaded storage.
setServiceLayoutVersion(getServiceLayoutVersion());
writeProperties(sd);
return sd;
} catch (IOException ioe) {
sd.unlock();
throw ioe;
}
}
