Re: [PATCH 3/4] src/t_immutable: Allow setting flags on existing files

[Amir Goldstein <amir73il@gmail.com>]

On Mon, Jan 25, 2021 at 2:46 PM Eryu Guan <eguan@linux.alibaba.com> wrote:
>
> On Sun, Jan 24, 2021 at 05:32:15PM +0200, Amir Goldstein wrote:
> > On Sun, Jan 24, 2021 at 5:14 PM Eryu Guan <guan@eryu.me> wrote:
> > >
> [snap]
> > > >
> > > >       if (create) {
> > > >         ret = create_test_area(argv[argc-1]);
> > > > -       if (ret || !runtest) {
> > > > +       if (ret || allow_existing) {
> > >
> > > With this change, compiler warns about 'runtest' is set but not used,
> > > and 'allow_existing' now indicates '!runtest' implicitly, which seems
> > > subtle. I think it's better to keep 'runtest' as the indicator to
> > > actually run the test?
> > >
> >
> > Sure, I removed it by mistake.
>
> Then this is the only place that needs update. I can fix it on commit,
> no need to resend then.
>

Excellent.

Now, about that kernel deadlock mentioned in is commented out line in
test overlay/075. The fix for that is in overlayfs-next:

147ec02b8705 - ovl: avoid deadlock on directory ioctl

But I am not so happy about adding a test that crashes stable/old kernels.
If you like I can post another test that is "dangerous" just for the deadlock
but after the fix is merged to master and 5.10.y so at least people who tests
the latest kernels will not crash.

Let me know your preference.

Thanks,
Amir.