in hbase-oss/src/main/java/org/apache/hadoop/hbase/oss/HBaseObjectStoreSemantics.java [421:430]
public FSDataOutputStream append(Path f) throws IOException {
AutoLock lock = sync.lockWrite(f);
try {
FSDataOutputStream stream = fs.append(f);
return new LockedFSDataOutputStream(stream, lock);
} catch (IOException e) {
lock.close();
throw(e);
}
}