HDFS-10991. Export hdfsTruncateFile symbol in libhdfs. Contributed by Surendra Singh Lilhore.

(cherry picked from commit dacd3ec66b111be24131957c986f0c748cf9ea26)
(cherry picked from commit 67f0319db667ed724a3c19cc2ab745ef661fc5f8)

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

@@ -148,6 +148,9 @@ Release 2.7.4 - UNRELEASED
     recovery may abort downstream applications.
     (Wei-Chiu Chuang)
 
+    HDFS-10991. Export hdfsTruncateFile symbol in libhdfs.
+    (Surendra Singh Lilhore via wang)
+
 Release 2.7.3 - 2016-08-25
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs/hdfs.h

@@ -408,6 +408,7 @@ extern  "C" {
      *         complete before proceeding with further file updates.
      *         -1 on error.
      */
+    LIBHDFS_EXTERNAL
     int hdfsTruncateFile(hdfsFS fs, const char* path, tOffset newlength);
 
     /**