Re: blktests failures with v5.19-rc1

Shinichiro Kawasaki
2022-07-20T02:30:43Z

On Jul 19, 2022 / 17:31, Bjorn Helgaas wrote:
> On Tue, Jul 19, 2022 at 04:50:36AM +0000, Shinichiro Kawasaki wrote:
> > On Jun 15, 2022 / 17:16, Keith Busch wrote:
> > > On Wed, Jun 15, 2022 at 02:47:27PM -0500, Bjorn Helgaas wrote:
> > > > On Tue, Jun 14, 2022 at 04:00:45AM +0000, Shinichiro Kawasaki wrote:
> > > > >
> > > > > Yeah, this WARN is confusing for us then it would be valuable to
> > > > > test by blktests not to repeat it. One point I wonder is: which test
> > > > > group the test case will it fall in? The nvme group could be the
> > > > > group to add, probably.
> > > > >
> > > > > Another point I wonder is other kernel test suite than blktests.
> > > > > Don't we have more appropriate test suite to check PCI device
> > > > > rescan/remove race ? Such a test sounds more like a PCI bus
> > > > > sub-system test than block/storage test.
> > > >
> > > > I'm not aware of such a test, but it would be nice to have one.
> > > >
> > > > Can you share your qemu config so I can reproduce this locally?
> > > >
> > > > Thanks for finding and reporting this!
> > >
> > > This ought to be reproducible with any pci device that can be
> > > removed. Since we initially observed with nvme, you can try with
> > > such a device. A quick way to get one appearing in qemu is to add
> > > parameters:
> > >
> > > -drive id=n,if=none,file=null-co://,format=raw \
> > > -device nvme,serial=foobar,drive=n
> >
> > Did you have chance to reproduce the WARN? Recently, it was reported
> > again [1] and getting attention.
>
> I have not paid any attention to this yet. From what I can tell, the
> problem was discovered by a test case (i.e., not reported by a
> real-world user), it is not a recent regression, we haven't identified
> a commit that introduced the problem, and we do not have a potential
> fix for it. Obviously it needs to be fixed and I'm not trying to
> minimize the problem; I just want to calibrate it against everything
> else.

Bjorn, thank you for sharing your view, which sounds reasonable for me.

--
Shin'ichiro Kawasaki