HDFS-6830. Revert accidental checkin

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1616884 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -479,9 +479,6 @@ Release 2.6.0 - UNRELEASED
     HDFS-6791. A block could remain under replicated if all of its replicas are on
     decommissioned nodes. (Ming Ma via jing9)
 
-    HDFS-6830. BlockInfo.addStorage fails when DN changes the storage for a
-    block replica. (Arpit Agarwal)
-
 Release 2.5.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfo.java

@@ -194,12 +194,24 @@ public class BlockInfo extends Block implements LightWeightGSet.LinkedElement {
    * Add a {@link DatanodeStorageInfo} location for a block
    */
   boolean addStorage(DatanodeStorageInfo storage) {
+    boolean added = true;
+    int idx = findDatanode(storage.getDatanodeDescriptor());
+    if(idx >= 0) {
+      if (getStorageInfo(idx) == storage) { // the storage is already there
+        return false;
+      } else {
+        // The block is on the DN but belongs to a different storage.
+        // Update our state.
+        removeStorage(getStorageInfo(idx));
+        added = false;      // Just updating storage. Return false.
+      }
+    }
     // find the last null node
     int lastNode = ensureCapacity(1);
     setStorageInfo(lastNode, storage);
     setNext(lastNode, null);
     setPrevious(lastNode, null);
-    return true;
+    return added;
   }
 
   /**
@@ -228,18 +240,16 @@ public class BlockInfo extends Block implements LightWeightGSet.LinkedElement {
    * Find specified DatanodeDescriptor.
    * @return index or -1 if not found.
    */
-  boolean findDatanode(DatanodeDescriptor dn) {
+  int findDatanode(DatanodeDescriptor dn) {
     int len = getCapacity();
     for(int idx = 0; idx < len; idx++) {
       DatanodeDescriptor cur = getDatanode(idx);
-      if(cur == dn) {
-        return true;
-      }
-      if(cur == null) {
+      if(cur == dn)
+        return idx;
+      if(cur == null)
         break;
-      }
     }
-    return false;
+    return -1;
   }
   /**
    * Find specified DatanodeStorageInfo.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -2065,7 +2065,7 @@ public class BlockManager {
     // Add replica if appropriate. If the replica was previously corrupt
     // but now okay, it might need to be updated.
     if (reportedState == ReplicaState.FINALIZED
-        && (!storedBlock.findDatanode(dn)
+        && (storedBlock.findDatanode(dn) < 0
         || corruptReplicas.isReplicaCorrupt(storedBlock, dn))) {
       toAdd.add(storedBlock);
     }
@@ -2246,7 +2246,7 @@ public class BlockManager {
         storageInfo, ucBlock.reportedBlock, ucBlock.reportedState);
 
     if (ucBlock.reportedState == ReplicaState.FINALIZED &&
-        !block.findDatanode(storageInfo.getDatanodeDescriptor())) {
+        block.findDatanode(storageInfo.getDatanodeDescriptor()) < 0) {
       addStoredBlock(block, storageInfo, null, true);
     }
   } 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeStorageInfo.java

@@ -208,28 +208,12 @@ public class DatanodeStorageInfo {
   }
 
   public boolean addBlock(BlockInfo b) {
-    // First check whether the block belongs to a different storage
-    // on the same DN.
-    boolean replaced = false;
-    DatanodeStorageInfo otherStorage =
-        b.findStorageInfo(getDatanodeDescriptor());
-
-    if (otherStorage != null) {
-      if (otherStorage != this) {
-        // The block belongs to a different storage. Remove it first.
-        otherStorage.removeBlock(b);
-        replaced = true;
-      } else {
-        // The block is already associated with this storage.
-        return false;
-      }
-    }
-
+    if(!b.addStorage(this))
+      return false;
     // add to the head of the data-node list
-    b.addStorage(this);
     blockList = b.listInsert(blockList, this);
     numBlocks++;
-    return !replaced;
+    return true;
   }
 
   boolean removeBlock(BlockInfo b) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockInfo.java

@@ -17,7 +17,6 @@
  */
 package org.apache.hadoop.hdfs.server.blockmanagement;
 
-import static org.hamcrest.core.Is.is;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
@@ -60,24 +59,17 @@ public class TestBlockInfo {
 
 
   @Test
-  public void testReplaceStorage() throws Exception {
+  public void testReplaceStorageIfDifferetnOneAlreadyExistedFromSameDataNode() throws Exception {
+    BlockInfo blockInfo = new BlockInfo(3);
 
-    // Create two dummy storages.
     final DatanodeStorageInfo storage1 = DFSTestUtil.createDatanodeStorageInfo("storageID1", "127.0.0.1");
     final DatanodeStorageInfo storage2 = new DatanodeStorageInfo(storage1.getDatanodeDescriptor(), new DatanodeStorage("storageID2"));
-    final int NUM_BLOCKS = 10;
-    BlockInfo[] blockInfos = new BlockInfo[NUM_BLOCKS];
 
-    // Create a few dummy blocks and add them to the first storage.
-    for (int i = 0; i < NUM_BLOCKS; ++i) {
-      blockInfos[i] = new BlockInfo(3);
-      storage1.addBlock(blockInfos[i]);
-    }
+    blockInfo.addStorage(storage1);
+    boolean added = blockInfo.addStorage(storage2);
 
-    // Try to move one of the blocks to a different storage.
-    boolean added = storage2.addBlock(blockInfos[NUM_BLOCKS/2]);
-    Assert.assertThat(added, is(false));
-    Assert.assertThat(blockInfos[NUM_BLOCKS/2].getStorageInfo(0), is(storage2));
+    Assert.assertFalse(added);
+    Assert.assertEquals(storage2, blockInfo.getStorageInfo(0));
   }
 
   @Test