From d70dd1a2df60fc85fdb42b105be81249baa38fc1 Mon Sep 17 00:00:00 2001
From: Hairong Kuang <hairong@apache.org>
Date: Tue, 11 Aug 2009 16:26:55 +0000
Subject: [PATCH] HADOOP-6177. FSInputChecker.getPos() would return position
 greater than the file size. Contributed by Hong Tang.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@803190 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                            |  9 ++++++---
 src/java/org/apache/hadoop/fs/FSInputChecker.java      |  1 +
 .../org/apache/hadoop/fs/TestChecksumFileSystem.java   | 10 +++++++---
 .../core/org/apache/hadoop/fs/TestLocalFileSystem.java |  5 +++--
 4 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index cbf1c79985..d02eaacda3 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -502,6 +502,9 @@ Trunk (unreleased changes)
 
     HADOOP-5638. More improvement on block placement performance. (hairong)
 
+    HADOOP-6180. NameNode slowed down when many files with same filename
+    were moved to Trash. (Boris Shkolnik via hairong)
+
   BUG FIXES
     
     HADOOP-5379. CBZip2InputStream to throw IOException on data crc error.
@@ -908,6 +911,9 @@ Trunk (unreleased changes)
     HADOOP-6124. Fix javac warning detection in test-patch.sh.  (Giridharan
     Kesavan via szetszwo)
 
+    HADOOP-6177. FSInputChecker.getPos() would return position greater 
+    than the file size. (Hong Tang via hairong)
+
 Release 0.20.1 - Unreleased
 
   INCOMPATIBLE CHANGES
@@ -4466,9 +4472,6 @@ Release 0.17.0 - 2008-05-18
     exponentially increasing number of records (up to 10,000
     records/log). (Zheng Shao via omalley)
  
-    HADOOP-6180. NameNode slowed down when many files with same filename
-    were moved to Trash. (Boris Shkolnik via hairong)
-
   BUG FIXES
 
     HADOOP-2195. '-mkdir' behaviour is now closer to Linux shell in case of
diff --git a/src/java/org/apache/hadoop/fs/FSInputChecker.java b/src/java/org/apache/hadoop/fs/FSInputChecker.java
index 1d8e03ff93..a0db285a03 100644
--- a/src/java/org/apache/hadoop/fs/FSInputChecker.java
+++ b/src/java/org/apache/hadoop/fs/FSInputChecker.java
@@ -174,6 +174,7 @@ private void fill(  ) throws IOException {
     assert(pos>=count);
     // fill internal buffer
     count = readChecksumChunk(buf, 0, buf.length);
+    if (count < 0) count = 0;
   }
   
   /*
diff --git a/src/test/core/org/apache/hadoop/fs/TestChecksumFileSystem.java b/src/test/core/org/apache/hadoop/fs/TestChecksumFileSystem.java
index c55fc3ae41..f60912010f 100644
--- a/src/test/core/org/apache/hadoop/fs/TestChecksumFileSystem.java
+++ b/src/test/core/org/apache/hadoop/fs/TestChecksumFileSystem.java
@@ -53,7 +53,11 @@ public void testVerifyChecksum() throws Exception {
     fout = localFs.create(testPath11);
     fout.write("testing you".getBytes());
     fout.close();
-    
+
+    TestLocalFileSystem.readFile(localFs, testPath, 128);
+    TestLocalFileSystem.readFile(localFs, testPath, 512);
+    TestLocalFileSystem.readFile(localFs, testPath, 1024);
+
     localFs.delete(localFs.getChecksumFile(testPath), true);
     assertTrue("checksum deleted", !localFs.exists(localFs.getChecksumFile(testPath)));
     
@@ -64,7 +68,7 @@ public void testVerifyChecksum() throws Exception {
     
     boolean errorRead = false;
     try {
-      TestLocalFileSystem.readFile(localFs, testPath);
+      TestLocalFileSystem.readFile(localFs, testPath, 1024);
     }catch(ChecksumException ie) {
       errorRead = true;
     }
@@ -72,7 +76,7 @@ public void testVerifyChecksum() throws Exception {
     
     //now setting verify false, the read should succeed
     localFs.setVerifyChecksum(false);
-    String str = TestLocalFileSystem.readFile(localFs, testPath);
+    String str = TestLocalFileSystem.readFile(localFs, testPath, 1024);
     assertTrue("read", "testing".equals(str));
     
   }
diff --git a/src/test/core/org/apache/hadoop/fs/TestLocalFileSystem.java b/src/test/core/org/apache/hadoop/fs/TestLocalFileSystem.java
index b244b9b5df..819c44d569 100644
--- a/src/test/core/org/apache/hadoop/fs/TestLocalFileSystem.java
+++ b/src/test/core/org/apache/hadoop/fs/TestLocalFileSystem.java
@@ -35,13 +35,14 @@ static void writeFile(FileSystem fs, Path name) throws IOException {
     stm.close();
   }
   
-  static String readFile(FileSystem fs, Path name) throws IOException {
-    byte[] b = new byte[1024];
+  static String readFile(FileSystem fs, Path name, int buflen) throws IOException {
+    byte[] b = new byte[buflen];
     int offset = 0;
     FSDataInputStream in = fs.open(name);
     for(int remaining, n;
         (remaining = b.length - offset) > 0 && (n = in.read(b, offset, remaining)) != -1;
         offset += n); 
+    assertEquals(offset, Math.min(b.length, in.getPos()));
     in.close();
 
     String s = new String(b, 0, offset);