Exercise fs freeze/unfreeze and mount/umount race, which could lead to
use-after-free oops.
This commit fixed the issue:
1494583 fix get_active_super()/umount() race
This test case is based on a script from Monakhov Dmitriy.
Signed-off-by: Eryu Guan <eguan@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Eryu Guan