diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 984637a625..0a82d20ccf 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -873,6 +873,9 @@ Release 2.5.0 - UNRELEASED
     HDFS-6312. WebHdfs HA failover is broken on secure clusters. 
     (daryn via tucu)
 
+    HDFS-6618. FSNamesystem#delete drops the FSN lock between removing INodes
+    from the tree and deleting them from the inode map (kihwal via cmccabe)
+
 Release 2.4.1 - 2014-06-23 
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
index 0901f54b24..4604a9a3df 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
@@ -654,7 +654,7 @@ boolean unprotectedRenameTo(String src, String dst, long timestamp,
                 dstIIP.getLatestSnapshotId(), collectedBlocks, removedINodes,
                 true).get(Quota.NAMESPACE);
             getFSNamesystem().removePathAndBlocks(src, collectedBlocks,
-                removedINodes);
+                removedINodes, false);
           }
         }
 
@@ -1190,7 +1190,7 @@ void unprotectedDelete(String src, long mtime) throws UnresolvedLinkException,
 
     if (filesRemoved >= 0) {
       getFSNamesystem().removePathAndBlocks(src, collectedBlocks, 
-          removedINodes);
+          removedINodes, false);
     }
   }
   
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
index 944d45b175..1d015b09bb 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
@@ -3525,7 +3525,7 @@ private boolean deleteInternal(String src, boolean recursive,
       getEditLog().logDelete(src, mtime, logRetryCache);
       incrDeletedFileCount(filesRemoved);
       // Blocks/INodes will be handled later
-      removePathAndBlocks(src, null, null);
+      removePathAndBlocks(src, null, removedINodes, true);
       ret = true;
     } finally {
       writeUnlock();
@@ -3534,13 +3534,6 @@ private boolean deleteInternal(String src, boolean recursive,
     removeBlocks(collectedBlocks); // Incremental deletion of blocks
     collectedBlocks.clear();
 
-    dir.writeLock();
-    try {
-      dir.removeFromInodeMap(removedINodes);
-    } finally {
-      dir.writeUnlock();
-    }
-    removedINodes.clear();
     if (NameNode.stateChangeLog.isDebugEnabled()) {
       NameNode.stateChangeLog.debug("DIR* Namesystem.delete: "
         + src +" is removed");
@@ -3578,14 +3571,24 @@ void removeBlocks(BlocksMapUpdateInfo blocks) {
    * @param blocks Containing the list of blocks to be deleted from blocksMap
    * @param removedINodes Containing the list of inodes to be removed from 
    *                      inodesMap
+   * @param acquireINodeMapLock Whether to acquire the lock for inode removal
    */
   void removePathAndBlocks(String src, BlocksMapUpdateInfo blocks,
-      List<INode> removedINodes) {
+      List<INode> removedINodes, final boolean acquireINodeMapLock) {
     assert hasWriteLock();
     leaseManager.removeLeaseWithPrefixPath(src);
     // remove inodes from inodesMap
     if (removedINodes != null) {
-      dir.removeFromInodeMap(removedINodes);
+      if (acquireINodeMapLock) {
+        dir.writeLock();
+      }
+      try {
+        dir.removeFromInodeMap(removedINodes);
+      } finally {
+        if (acquireINodeMapLock) {
+          dir.writeUnlock();
+        }
+      }
       removedINodes.clear();
     }
     if (blocks == null) {