fix bug

Author: hfutatzhanghb

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataSetLockManager.java

@@ -168,7 +168,7 @@ public AutoCloseDataSetLock readLock(LockLevel level, String... resources) {
       AutoCloseDataSetLock bpLock = getReadLock(LockLevel.BLOCK_POOl, resources[0]);
       AutoCloseDataSetLock volLock = getReadLock(LockLevel.VOLUME, resources[0], resources[1]);
       volLock.setParentLock(bpLock);
-      AutoCloseDataSetLock dirLock = getWriteLock(level, resources);
+      AutoCloseDataSetLock dirLock = getReadLock(level, resources);
       dirLock.setParentLock(volLock);
       if (openLockTrace) {
         LOG.debug("Sub lock " + resources[0] + resources[1] + resources[2] + " parent lock " +
@@ -195,7 +195,7 @@ public AutoCloseDataSetLock writeLock(LockLevel level, String... resources) {
       AutoCloseDataSetLock bpLock = getReadLock(LockLevel.BLOCK_POOl, resources[0]);
       AutoCloseDataSetLock volLock = getReadLock(LockLevel.VOLUME, resources[0], resources[1]);
       volLock.setParentLock(bpLock);
-      AutoCloseDataSetLock dirLock = getReadLock(level, resources);
+      AutoCloseDataSetLock dirLock = getWriteLock(level, resources);
       dirLock.setParentLock(volLock);
       if (openLockTrace) {
         LOG.debug("Sub lock " + resources[0] + resources[1] + resources[2] + " parent lock " +