ffs_flushfiles
int ffs_flushfiles(struct mount *, int, struct thread *);
if ((error = ffs_flushfiles(oldmnt, flags | early, td)) != 0)
ffs_flushfiles(mp, FORCECLOSE, td);
error = ffs_flushfiles(mp, flags, td);
error = ffs_flushfiles(mp, flags, td);