public FSDataInputStream open(final FileSystem fs) throws IOException {
    return new FSDataInputStream(new FileLinkInputStream(fs, this));
  }
Open the FileLink for read.
<p>
It uses a wrapper of FSDataInputStream that is agnostic to the location of the file, even if
the file switches between locations.
@param fs {@link FileSystem} on which to open the FileLink
@return InputStream for reading the file link.
@throws IOException on unexpected error.
hbase-server/src/main/java/org/apache/hadoop/hbase/io/FileLink.java