diff --git a/pom.xml b/pom.xml
index 7fe2f6af..6160cbdc 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>com.qcloud.cos</groupId>
     <artifactId>hadoop-cos</artifactId>
-    <version>8.1.3</version>
+    <version>8.1.4</version>
     <packaging>jar</packaging>
 
     <name>Apache Hadoop Tencent Cloud COS Support</name>
diff --git a/src/main/java/org/apache/hadoop/fs/CosNConfigKeys.java b/src/main/java/org/apache/hadoop/fs/CosNConfigKeys.java
index 127f40e6..8d4735a0 100644
--- a/src/main/java/org/apache/hadoop/fs/CosNConfigKeys.java
+++ b/src/main/java/org/apache/hadoop/fs/CosNConfigKeys.java
@@ -12,7 +12,7 @@
 @InterfaceStability.Unstable
 public class CosNConfigKeys extends CommonConfigurationKeys {
     public static final String USER_AGENT = "fs.cosn.user.agent";
-    public static final String DEFAULT_USER_AGENT = "cos-hadoop-plugin-v8.1.3";
+    public static final String DEFAULT_USER_AGENT = "cos-hadoop-plugin-v8.1.4";
 
     public static final String TENCENT_EMR_VERSION_KEY = "fs.emr.version";
 
diff --git a/src/main/java/org/apache/hadoop/fs/cosn/buffer/CosNByteBuffer.java b/src/main/java/org/apache/hadoop/fs/cosn/buffer/CosNByteBuffer.java
index 917852ea..a9d767c2 100644
--- a/src/main/java/org/apache/hadoop/fs/cosn/buffer/CosNByteBuffer.java
+++ b/src/main/java/org/apache/hadoop/fs/cosn/buffer/CosNByteBuffer.java
@@ -15,16 +15,19 @@ public abstract class CosNByteBuffer implements Closeable {
             LoggerFactory.getLogger(CosNByteBuffer.class);
 
     protected ByteBuffer byteBuffer;
-    private int lastWritePosition;
+    private int nextWritePosition;
 
     public CosNByteBuffer(ByteBuffer byteBuffer) {
         this.byteBuffer = byteBuffer;
-        this.lastWritePosition = this.byteBuffer.position();
+        this.nextWritePosition = this.byteBuffer.position();
     }
 
-    public CosNByteBuffer put(byte b) {
+    public CosNByteBuffer put(byte b) throws IOException {
+        if (this.byteBuffer.hasRemaining()) {
+            throw new IOException("There is no remaining in the buffer.");
+        }
         this.byteBuffer.put(b);
-        this.lastWritePosition = this.byteBuffer.position();
+        this.nextWritePosition = this.byteBuffer.position();
         return this;
     }
 
@@ -37,7 +40,7 @@ public CosNByteBuffer put(byte[] src, int offset, int length) throws IOException
         }
 
         this.byteBuffer.put(src, offset, length);
-        this.lastWritePosition = this.byteBuffer.position();
+        this.nextWritePosition = this.byteBuffer.position();
         return this;
     }
 
@@ -84,6 +87,7 @@ public CosNByteBuffer reset() {
 
     public CosNByteBuffer clear() {
         this.byteBuffer.clear();
+        this.nextWritePosition = 0;
         return this;
     }
 
@@ -98,13 +102,13 @@ public CosNByteBuffer rewind() {
     }
 
     public CosNByteBuffer flipRead() {
-        this.limit(this.lastWritePosition);
+        this.limit(this.nextWritePosition);
         this.position(0);
         return this;
     }
 
     public CosNByteBuffer flipWrite() {
-        this.position(this.lastWritePosition);
+        this.position(this.nextWritePosition);
         this.limit(this.byteBuffer.capacity());
         return this;
     }
@@ -129,6 +133,6 @@ public void close() throws IOException {
         this.byteBuffer.clear();
 
         this.byteBuffer = null;
-        this.lastWritePosition = -1;
+        this.nextWritePosition = -1;
     }
 }