HDFS-16274. Improve error msg for FSNamesystem#startFileInt (apache#3554)

* HDFS-16274. Improve log for FSNamesystem#startFileInt

* fix failed unit test

Author: tomscut

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

@@ -2722,11 +2722,10 @@ private HdfsFileStatus startFileInt(String src,
       iip = FSDirWriteFileOp.resolvePathForStartFile(
           dir, pc, src, flag, createParent);
 
-
       if (blockSize < minBlockSize) {
-        throw new IOException("Specified block size is less than configured" +
-            " minimum value (" + DFSConfigKeys.DFS_NAMENODE_MIN_BLOCK_SIZE_KEY
-            + "): " + blockSize + " < " + minBlockSize);
+        throw new IOException("Specified block size " + blockSize +
+            " is less than configured minimum value " +
+            DFSConfigKeys.DFS_NAMENODE_MIN_BLOCK_SIZE_KEY + "=" + minBlockSize);
       }
 
       if (shouldReplicate) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFileLimit.java

@@ -210,8 +210,9 @@ public void testMinBlockSizeLimit() throws Exception {
         assert false : "Expected IOException after creating a file with small" +
             " blocks ";
       } catch (IOException e) {
-        GenericTestUtils.assertExceptionContains("Specified block size is less",
-            e);
+        GenericTestUtils.assertExceptionContains(
+            "is less than configured minimum value " +
+                "dfs.namenode.fs-limits.min-block-size=", e);
       }
     } finally {
       cluster.shutdown();