[HDFS-16787] Remove the redundant lock in DataSetLockManager#removeLock.

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.4.0
• Fix Version/s: 3.4.0
• Component/s: datanode
• Labels: pull-request-available
• Target Version/s: 3.4.0
• Hadoop Flags: Reviewed
• Assignee: ZanderXu
• Reporter: ZanderXu
• Created: 29/Sep/22 03:58
• Updated: 28/Jan/24 08:02
• Resolved: 10/Oct/22 12:06

Description

During patching the datanode fine-grained locking, found there is a redundant lock in DataSetLockManager#removeLock, and the code as bellow:

@Override
public void removeLock(LockLevel level, String... resources) {
  String lockName = generateLockName(level, resources);
  try (AutoCloseDataSetLock lock = writeLock(level, resources)) {
    // Here, this lock is redundant.
    lock.lock();
    lockMap.removeLock(lockName);
  }
} 

Issue Links

• relates to: HDFS-15382 Split one FsDatasetImpl lock to volume grain locks.
• links to: GitHub Pull Request #4948