GFS2: fatal: invalid metadata block after gfs2_grow
    
    This patch adds an fsync(fd) to the bsync function of libgfs2.
    The gfs2_grow program was writing out its buffers, then
    modifying the rindex, signaling the kernel code to read in the
    new rgrp information.  The problem was caused by a timing window
    whereby the gfs2 kernel code read in the new blocks before they
    landed on disk from those write requests.
    
    rhbz#546683