diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 2244f367671..e8fb2c589a8 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -374,6 +374,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-8726. Move protobuf files that define the client-sever protocols to
     hdfs-client. (wheat9)
 
+    HDFS-8751. Remove setBlocks API from INodeFile and misc code cleanup. (Zhe
+    Zhang via jing9)
+
   OPTIMIZATIONS
 
     HDFS-8026. Trace FSOutputSummer#writeChecksumChunks rather than
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirConcatOp.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirConcatOp.java
index 3f22f51e879..bb001304be9 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirConcatOp.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirConcatOp.java
@@ -228,7 +228,7 @@ class FSDirConcatOp {
     int count = 0;
     for (INodeFile nodeToRemove : srcList) {
       if(nodeToRemove != null) {
-        nodeToRemove.setBlocks(null);
+        nodeToRemove.clearBlocks();
         nodeToRemove.getParent().removeChild(nodeToRemove);
         fsd.getINodeMap().remove(nodeToRemove);
         count++;
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java
index 3e8c203a97c..a7d8964052d 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java
@@ -369,7 +369,7 @@ public class INodeFile extends INodeWithAdditionalFields
   }
 
   /** Set the replication factor of this file. */
-  public final void setFileReplication(short replication) {
+  private void setFileReplication(short replication) {
     header = HeaderFormat.REPLICATION.BITS.combine(replication, header);
   }
 
@@ -413,33 +413,35 @@ public class INodeFile extends INodeWithAdditionalFields
     setStoragePolicyID(storagePolicyId);
   }
 
-  @Override
+  @Override // INodeFileAttributes
   public long getHeaderLong() {
     return header;
   }
 
   /** @return the blocks of the file. */
-  @Override
+  @Override // BlockCollection
   public BlockInfo[] getBlocks() {
     return this.blocks;
   }
 
   /** @return blocks of the file corresponding to the snapshot. */
   public BlockInfo[] getBlocks(int snapshot) {
-    if(snapshot == CURRENT_STATE_ID || getDiffs() == null)
+    if(snapshot == CURRENT_STATE_ID || getDiffs() == null) {
       return getBlocks();
+    }
     FileDiff diff = getDiffs().getDiffById(snapshot);
-    BlockInfo[] snapshotBlocks =
-        diff == null ? getBlocks() : diff.getBlocks();
-    if(snapshotBlocks != null)
+    BlockInfo[] snapshotBlocks = diff == null ? getBlocks() : diff.getBlocks();
+    if (snapshotBlocks != null) {
       return snapshotBlocks;
+    }
     // Blocks are not in the current snapshot
     // Find next snapshot with blocks present or return current file blocks
     snapshotBlocks = getDiffs().findLaterSnapshotBlocks(snapshot);
     return (snapshotBlocks == null) ? getBlocks() : snapshotBlocks;
   }
 
-  void updateBlockCollection() {
+  /** Used during concat to update the BlockCollection for each block. */
+  private void updateBlockCollection() {
     if (blocks != null) {
       for(BlockInfo b : blocks) {
         b.setBlockCollection(this);
@@ -486,10 +488,15 @@ public class INodeFile extends INodeWithAdditionalFields
   }
 
   /** Set the blocks. */
-  public void setBlocks(BlockInfo[] blocks) {
+  private void setBlocks(BlockInfo[] blocks) {
     this.blocks = blocks;
   }
 
+  /** Clear all blocks of the file. */
+  public void clearBlocks() {
+    setBlocks(null);
+  }
+
   @Override
   public void cleanSubtree(ReclaimContext reclaimContext,
       final int snapshot, int priorSnapshotId) {
@@ -543,7 +550,7 @@ public class INodeFile extends INodeWithAdditionalFields
         blk.setBlockCollection(null);
       }
     }
-    setBlocks(null);
+    clearBlocks();
     if (getAclFeature() != null) {
       AclStorage.removeAclFeature(getAclFeature());
     }
@@ -783,16 +790,18 @@ public class INodeFile extends INodeWithAdditionalFields
   public long collectBlocksBeyondMax(final long max,
       final BlocksMapUpdateInfo collectedBlocks) {
     final BlockInfo[] oldBlocks = getBlocks();
-    if (oldBlocks == null)
+    if (oldBlocks == null) {
       return 0;
+    }
     // find the minimum n such that the size of the first n blocks > max
     int n = 0;
     long size = 0;
     for(; n < oldBlocks.length && max > size; n++) {
       size += oldBlocks[n].getNumBytes();
     }
-    if (n >= oldBlocks.length)
+    if (n >= oldBlocks.length) {
       return size;
+    }
 
     // starting from block n, the data is beyond max.
     // resize the array.
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestINodeFile.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestINodeFile.java
index 24203e98043..be9eaae3976 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestINodeFile.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestINodeFile.java
@@ -21,6 +21,7 @@ package org.apache.hadoop.hdfs.server.namenode;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.fail;
 
 import java.io.FileNotFoundException;
@@ -1102,4 +1103,12 @@ public class TestINodeFile {
     f1 = inf.getXAttrFeature();
     assertEquals(f1, null);
   }
+
+  @Test
+  public void testClearBlocks() {
+    INodeFile toBeCleared = createINodeFiles(1, "toBeCleared")[0];
+    assertEquals(1, toBeCleared.getBlocks().length);
+    toBeCleared.clearBlocks();
+    assertNull(toBeCleared.getBlocks());
+  }
 }