From 67647ed7a26eb1c8f910a0311adf17ef6933f774 Mon Sep 17 00:00:00 2001
From: Wei-Chiu Chuang <weichiu@cloudera.com>
Date: Wed, 23 Oct 2019 15:26:51 -0700
Subject: [PATCH] HDFS-14910. Rename Snapshot with Pre Descendants Fail With
 IllegalArgumentException. Contributed by Wei-Chiu Chuang.

Change-Id: I858b605eae4a9aaf481777488466307e9fb0d50c
---
 .../org/apache/hadoop/hdfs/server/namenode/INodeDirectory.java | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeDirectory.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeDirectory.java
index b592c3ff896d8..85d5a45344a9f 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeDirectory.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeDirectory.java
@@ -841,7 +841,8 @@ public void cleanSubtree(ReclaimContext reclaimContext, final int snapshotId,
       // If the inode has empty diff list and sf is not a
       // DirectorySnapshottableFeature, remove the feature to save heap.
       if (sf.getDiffs().isEmpty() &&
-          !(sf instanceof DirectorySnapshottableFeature)) {
+          !(sf instanceof DirectorySnapshottableFeature) &&
+          getDirectoryWithSnapshotFeature() != null) {
         this.removeFeature(sf);
       }
     } else {