Multi-threads freeze/unfreeze maybe trigger some bugs, e.g: panic,
hang or data corruption etc. It does't check the return value of
freeze/unfreeze, but it tries to make sure fsstress won't run fails,
and no any other bugs happen.
[eguan: add comment on why we check _scratch_mount failure]
Signed-off-by: Zorro Lang <zlang@redhat.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
Zorro Lang