svn merge -c 1492941 from trunk for HDFS-4845. FSNamesystem.deleteInternal should acquire write-lock before changing the inode map.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1492961 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -350,6 +350,8 @@ Release 2.1.0-beta - UNRELEASED
     HDFS-3163. TestHDFSCLI.testAll fails if the user name is not all lowercase.
     (Brandon Li via atm)
 
+    HDFS-4845. FSNamesystem.deleteInternal should acquire write-lock before
+    changing the inode map.  (Arpit Agarwal via szetszwo)
 
   BREAKDOWN OF HDFS-347 SUBTASKS AND RELATED JIRAS
 

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

@@ -2916,7 +2916,12 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     getEditLog().logSync(); 
     removeBlocks(collectedBlocks); // Incremental deletion of blocks
     collectedBlocks.clear();
-    dir.removeFromInodeMap(removedINodes);
+    dir.writeLock();
+    try {
+      dir.removeFromInodeMap(removedINodes);
+    } finally {
+      dir.writeUnlock();
+    }
     removedINodes.clear();
     if (NameNode.stateChangeLog.isDebugEnabled()) {
       NameNode.stateChangeLog.debug("DIR* Namesystem.delete: "