diff --git a/servers/src/main/java/tachyon/worker/block/BlockLockManager.java b/servers/src/main/java/tachyon/worker/block/BlockLockManager.java
index 84d98326a203..d76065af56b9 100644
--- a/servers/src/main/java/tachyon/worker/block/BlockLockManager.java
+++ b/servers/src/main/java/tachyon/worker/block/BlockLockManager.java
@@ -66,6 +66,12 @@ public BlockLockManager(BlockMetadataManager metaManager) {
     }
   }
 
+  /**
+   * Get index of the lock that will be used to lock the block
+   * 
+   * @param blockId the id of the block
+   * @return hash index of the lock
+   */
   public static int blockHashIndex(long blockId) {
     return Math.abs(HASH_FUNC.hashLong(blockId).asInt()) % NUM_LOCKS;
   }
diff --git a/servers/src/main/java/tachyon/worker/block/BlockStoreMeta.java b/servers/src/main/java/tachyon/worker/block/BlockStoreMeta.java
index d9b908a462d1..68075f9074ea 100644
--- a/servers/src/main/java/tachyon/worker/block/BlockStoreMeta.java
+++ b/servers/src/main/java/tachyon/worker/block/BlockStoreMeta.java
@@ -83,7 +83,7 @@ public Map<Long, String> getDirPaths() {
 
   public int getNumberOfBlocks() {
     int numberOfBlocks = 0;
-    for (List blockIds : mBlockIdsOnDirs.values()) {
+    for (List<Long> blockIds : mBlockIdsOnDirs.values()) {
       numberOfBlocks += blockIds.size();
     }
     return numberOfBlocks;