[bug report] blktests nvme/022 lead kernel WARNING and NULL pointer

[Yi Zhang]

On Sat, May 1, 2021 at 8:55 AM Sagi Grimberg <sagi at grimberg.me> wrote:
>
>
> > Hello
> > Recently CKI reproduced this WARNING and NULL pointer with
> > linux-block/for-next on aarch64, seems it's one regression, I will try
> > if I can bisect the culprit.
> >
> > blktests: nvme/022 (test NVMe reset command on NVMeOF file-backed ns)
> >
> > [ 1879.759978] run blktests nvme/022 at 2021-04-30 12:30:36
> > [ 1879.804283] nvmet: adding nsid 1 to subsystem blktests-subsystem-1
> > [ 1879.819087] nvmet: creating controller 1 for subsystem
> > blktests-subsystem-1 for NQN
> > nqn.2014-08.org.nvmexpress:uuid:0da758a0-4d84-4133-82dd-9801235b55cd.
> > [ 1879.833081] nvmet: unhandled identify cns 6 on qid 0
> > [ 1879.838079] nvme nvme0: creating 128 I/O queues.
> > [ 1879.852353] nvme nvme0: new ctrl: "blktests-subsystem-1"
> > [ 1880.879731] nvme nvme0: resetting controller
> > [ 1889.940458] nvmet: ctrl 1 keep-alive timer (5 seconds) expired!
> > [ 1889.946377] nvmet: ctrl 1 fatal error occurred!
> > [ 1889.950928] nvme nvme0: Removing ctrl: NQN "blktests-subsystem-1"
>
> It appears that we are somehow now expire the kato after/during a reset
> sequence and then seem to race reset and remove...
>
> bisection will help definitely.
>
Hi Sagi

Bisect shows bellow commits was the first bad commit.

commit a70b81bd4d9d2d6c05cfe6ef2a10bccc2e04357a (refs/bisect/bad)
Author: Hannes Reinecke <hare at suse.de>
Date:   Fri Apr 16 13:46:20 2021 +0200

    nvme: sanitize KATO setting

Thanks
Yi