code: public static int posix_fallocate(int fd, long offset, long len) throws IOException {
  
          int result = Delegate.posix_fallocate(fd, offset, len);
  
          if(result != 0) {
              logger.warn(errno.strerror(result));
          }
  
          return result;
  
      }
docs: <b>posix documentation</b>
  
  <p>
  The function posix_fallocate() ensures that disk space is allocated for
  the file referred to by the descriptor fd for the bytes in the range
  starting at offset and continuing for len bytes. After a successful call
  to posix_fallocate(), subsequent writes to bytes in the specified range
  are guaranteed not to fail because of lack of disk space.
  
  <p>
  If the size of the file is less than offset+len, then the file is
  increased to this size; otherwise the file size is left unchanged.
  
  <p>
  Return Value
  
  <p>
  posix_fallocate() returns zero on success, or an error number on failure.
  Note that errno is not set.
  
  <b>java documentation</b>
  
  We do not return -1 if we fail but instead throw an IOException
  
  @throws IOException if this call fails.