Re: blktests failures with v5.19-rc1

[Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>]

On Jun 16, 2022 / 07:13, Yi Zhang wrote:
> On Thu, Jun 16, 2022 at 6:01 AM Chaitanya Kulkarni
> <chaitanyak@nvidia.com> wrote:
> >
> > On 6/15/22 12:47, Bjorn Helgaas wrote:
> > > On Tue, Jun 14, 2022 at 04:00:45AM +0000, Shinichiro Kawasaki wrote:
> > >> On Jun 14, 2022 / 02:38, Chaitanya Kulkarni wrote:
> > >>> Shinichiro,

[snip]

> > >>> I think it is worth adding a testcase to blktests to make sure
> > >>> these future releases will test this.
> > >>
> > >> 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.
> > >>
> >
> > since this issue been discovered with nvme rescan and revmoe,
> > it should be added to the nvme category.
> 
> We already have nvme/032 which tests nvme rescan/reset/remove and the
> issue was reported by running this one, do we still need one more?

That is a point. Current nvme/032 checks nvme pci adapter rescan/reset/remove
during I/O to catch problems in nvme driver and block layer, but actually it
can catch the problem in pci sub-system also. I think Chaitanya's motivation
for the new test case is to distinguish those two.

If we have the new test case, its code will be similar and duplicated as
nvme/032 code. To avoid such duplication, it would be good to improve nvme/032
to have two steps. The 1st step checks that nvme pci adapter rescan/reset/remove
without I/O causes no kernel WARN (or any other unexpected kernel messages). Any
issue found in this step is reported as a pci sub-system issue. The 2nd step
checks nvme pci adapter rescan/reset/remove during I/O, as the current nvme/032
does. With this, we don't need the new test case, but still we can distinguish
the problems in nvme/block sub-system and pci sub-system.

> > >> 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 don't think so we could have caught it long time back,
> > but we clearly did not.

I see, then it looks that blktests is the test suite to test it.

-- 
Shin'ichiro Kawasaki