Re: [PATCH 12/11 TESTSUITE] audit_testsuite: Add stress test for tree watches

From: Jan Kara <jack@suse.cz>
To: Paul Moore <paul@paul-moore.com>
Cc: Jan Kara <jack@suse.cz>,
	viro@zeniv.linux.org.uk, linux-audit@redhat.com,
	linux-fsdevel@vger.kernel.org, rgb@redhat.com,
	amir73il@gmail.com
Subject: Re: [PATCH 12/11 TESTSUITE] audit_testsuite: Add stress test for tree watches
Date: Mon, 15 Oct 2018 12:04:03 +0200	[thread overview]
Message-ID: <20181015100403.GA30927@quack2.suse.cz> (raw)
In-Reply-To: <166655f3fa8.2781.85c95baa4474aabc7814e68940a78392@paul-moore.com>

On Thu 11-10-18 19:03:53, Paul Moore wrote:
> On October 11, 2018 7:39:39 AM Jan Kara <jack@suse.cz> wrote:
> > On Wed 10-10-18 02:43:46, Paul Moore wrote:
> >> On Tue, Oct 9, 2018 at 3:40 AM Jan Kara <jack@suse.cz> wrote:
> >>> On Fri 05-10-18 17:06:22, Paul Moore wrote:
> >>>> On Tue, Sep 4, 2018 at 12:06 PM Jan Kara <jack@suse.cz> wrote:
> >>>>> Add stress test for stressing audit tree watches by adding and deleting
> >>>>> rules while events are generated and watched filesystems are mounted and
> >>>>> unmounted in parallel.
> >>>>>
> >>>>> Signed-off-by: Jan Kara <jack@suse.cz>
> >>>>> ---
> >>>>> tests/stress_tree/Makefile |   8 +++
> >>>>> tests/stress_tree/test     | 171 +++++++++++++++++++++++++++++++++++++++++++++
> >>>>> 2 files changed, 179 insertions(+)
> >>>>> create mode 100644 tests/stress_tree/Makefile
> >>>>> create mode 100755 tests/stress_tree/test
> >>>>
> >>>> No commentary on the test itself, other than perhaps it should live
> >>>> under test_manual/, but in running the tests in a loop today I am
> >>>> reliably able to panic my test kernel after ~30m or so.
> >>>
> >>> Interesting. How do you run the test?
> >>
> >> Nothing fancy, just a simple bash loop:
> >>
> >> # cd tests/stress_tree
> >> # while ./test; do /bin/true; done
> >
> > OK, I did succeed in reproducing some problems with my patches - once I was
> > able to trigger a livelock and following softlockup warning - this is
> > actually a problem introduced by my patches, and once a use after free
> > issue (not sure what that was since after I've added some debugging I
> > wasn't able to trigger it anymore). Anyway, I'll try more after fixing the
> > livelock. Do you want me to add fixes on top of my series or just fixup the
> > original series?
> 
> Since these are pretty serious bugs, and I try to avoid merging
> known-broken patches which will go up to Linus, why don't you go ahead
> and respin the patchset with the new fixes included.  You can also use
> the opportunity to squash in the rename patch and fix that mid-patchset
> compilation problem that I fixed up during the merge.

OK, I'm now testing a version with the softlockup fixed and some locking
around untag_chunk() simplified when I had to meddle with that anyway. I'll
see if I can hit further failures...

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR