code: private static void trySyncFileRange(int fd, long offset, long nbytes, int flags)
    {
      if (!initialized || !syncFileRangePossible || fd < 0) {
        return;
      }
      try {
        int ret_code = sync_file_range(fd, offset, nbytes, flags);
        if (ret_code != 0) {
          log.warn("failed on syncing fd [%d], offset [%d], bytes [%d], ret_code [%d], errno [%d]",
              fd, offset, nbytes, ret_code, Native.getLastError());
          return;
        }
      }
      catch (UnsupportedOperationException uoe) {
        log.warn(uoe, "sync_file_range is not supported");
        syncFileRangePossible = false;
      }
      catch (UnsatisfiedLinkError nle) {
        log.warn(nle, "sync_file_range failed on fd [%d], offset [%d], bytes [%d]", fd, offset, nbytes);
        syncFileRangePossible = false;
      }
      catch (Exception e) {
        log.warn(e, "Unknown exception: sync_file_range failed on fd [%d], offset [%d], bytes [%d]",
            fd, offset, nbytes);
        syncFileRangePossible = false;
      }
    }
docs: Sync part of an open file to the file system.
  
  @param fd      The file descriptor of the source file.
  @param offset  The offset within the file.
  @param nbytes  The number of bytes to be synced.
  @param flags   Signal how to synchronize