Addressed review comments.

Author: bshashikant

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

@@ -24,7 +24,6 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 
 import org.apache.hadoop.fs.PathIsNotDirectoryException;
 import org.apache.hadoop.fs.permission.FsAction;
@@ -894,7 +893,7 @@ public boolean metadataEquals(INodeDirectoryAttributes other) {
     return other != null && getQuotaCounts().equals(other.getQuotaCounts())
         && getPermissionLong() == other.getPermissionLong()
         && getAclFeature() == other.getAclFeature()
-        && Objects.equals(getXAttrFeature(), other.getXAttrFeature());
+        && getXAttrFeature() == other.getXAttrFeature();
   }
 
 

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

@@ -24,7 +24,6 @@
 
 import org.apache.hadoop.thirdparty.com.google.common.base.Preconditions;
 
-import java.util.Objects;
 
 /**
  * The attributes of an inode.
@@ -63,7 +62,7 @@ public boolean metadataEquals(INodeDirectoryAttributes other) {
       return other != null && getQuotaCounts().equals(other.getQuotaCounts())
           && getPermissionLong() == other.getPermissionLong()
           && getAclFeature() == other.getAclFeature()
-          && Objects.equals(getXAttrFeature(), other.getXAttrFeature());
+          && getXAttrFeature() == other.getXAttrFeature();
     }
   }
 

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

@@ -24,11 +24,14 @@
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.Date;
+import java.util.Objects;
+
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.server.namenode.AclFeature;
+import org.apache.hadoop.hdfs.server.namenode.INodeDirectoryAttributes;
 import org.apache.hadoop.hdfs.server.namenode.ContentSummaryComputationContext;
 import org.apache.hadoop.hdfs.server.namenode.DirectoryWithQuotaFeature;
 import org.apache.hadoop.hdfs.server.namenode.FSImageFormat;
@@ -196,6 +199,18 @@ public ContentSummaryComputationContext computeContentSummary(
       return computeDirectoryContentSummary(summary, snapshotId);
     }
 
+    @Override
+    public boolean metadataEquals(INodeDirectoryAttributes other) {
+      return other != null && getQuotaCounts().equals(other.getQuotaCounts())
+          && getPermissionLong() == other.getPermissionLong()
+          // Acl feature maintains a reference counted map, thereby
+          // every snapshot copy should point to the same Acl object unless
+          // there is no change in acl values.
+          // Reference equals is hence intentional here.
+          && getAclFeature() == other.getAclFeature()
+          && Objects.equals(getXAttrFeature(), other.getXAttrFeature());
+    }
+
     @Override
     public String getFullPathName() {
       return getSnapshotPath(getParent().getFullPathName(), getLocalName());