code: public LocatedBlocks getBlockLocations(String src, INode inode, long offset, long length,
                                           boolean doAccessTime, BlockMetaInfoType type)
      throws IOException {
      if (offset < 0) {
        throw new IOException("Negative offset is not supported. File: " + src);
      }
      if (length < 0) {
        throw new IOException("Negative length is not supported. File: " + src);
      }
      final LocatedBlocks ret = getBlockLocationsInternal(src, inode,
        offset, length, Integer.MAX_VALUE, doAccessTime, type);
      if (auditLog.isInfoEnabled()) {
        logAuditEvent(getCurrentUGI(),
          Server.getRemoteIp(),
          "open", src, null, null);
      }
      return ret;
    }
docs: Get block locations within the specified range.
  
  @see ClientProtocol#getBlockLocations(String, long, long)