fix update quota

Author: huangzhaobo99

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java

@@ -1409,12 +1409,15 @@ public INodesInPath addLastINode(INodesInPath existing, INode inode, FsPermissio
     boolean isRename = (inode.getParent() != null);
     final boolean added = parent.addChild(inode, true,
         existing.getLatestSnapshotId());
-    if (!added && updateQuota) {
-      QuotaCounts counts = quotaCount.orElseGet(() -> inode.
-          computeQuotaUsage(getBlockStoragePolicySuite(),
-          parent.getStoragePolicyID(), false,
-          Snapshot.CURRENT_STATE_ID));
-      updateCountNoQuotaCheck(existing, pos, counts.negation());
+    if (!added) {
+      // When adding INode fails, if 'updateQuota' is true, rollback quotaUsage.
+      if (updateQuota) {
+        QuotaCounts counts = quotaCount.orElseGet(() -> inode.
+            computeQuotaUsage(getBlockStoragePolicySuite(),
+            parent.getStoragePolicyID(), false,
+            Snapshot.CURRENT_STATE_ID));
+        updateCountNoQuotaCheck(existing, pos, counts.negation()); 
+      }
       return null;
     } else {
       if (!isRename) {