checkAccess(out, true, block, blockToken,
Op.READ_BLOCK, BlockTokenSecretManager.AccessMode.READ);
// send the block
BlockSender blockSender = null;
DatanodeRegistration dnR =
datanode.getDNRegistrationForBP(block.getBlockPoolId());
final String clientTraceFmt =
clientName.length() > 0 && ClientTraceLog.isInfoEnabled()
? String.format(DN_CLIENTTRACE_FORMAT, localAddress, remoteAddress,
"%d", "HDFS_READ", clientName, "%d",
dnR.getDatanodeUuid(), block, "%d")
: dnR + " Served block " + block + " to " +
remoteAddress;
updateCurrentThreadName("Sending block " + block);
try {