mps(4) blocks panic-reboot

[Stephen Mcconnell]

> -----Original Message-----
> From: Harry Schmalzbauer [mailto:freebsd at omnilan.de]
> Sent: Thursday, June 01, 2017 12:03 PM
> To: Stephen Mcconnell
> Cc: freebsd-scsi at freebsd.org; Scott Long
> Subject: Re: mps(4) blocks panic-reboot
>
> Bezüglich Stephen Mcconnell's Nachricht vom 01.06.2017 19:36 (localtime):
> > Can you try the attached patch and let me know how it goes? I didn't
> > test it, but since you know how, it might be easier this way. This was
> > diff'd from the latest mps files in stable/11, which I recently updated
> > (today).
>
> Thanks a lot, I noticed the highly appreciated MFC!
> Things are cooking... There were sysdecode userland changes, so I need to
> buidl
> world also, before my rollout system provides the update for this
> machine – will
> be ready in an hour.
>
> Since I have expert's attention, I'd like to ask a another mps(4) related
> question:
>
> I had unionfs deadlocks.  (I'm aware of the broken status of unionfs, and
> since
> I'm not able to fix it myself at the moment, I already replaced it with
> nullfs
> where possible, true for the following event)
>
> Since this machine has a memory-disk as rootfs (and 5 SSDs via mps(4) for
> bootpool and a separate syspool, where /var e.g. lives), I guess the
> deadlock is
> responsible for simultanious disappearance of all mps(4) attached drives.
>
> Is that plausable? (meaning, does the mps(4) driver depend on filesystem
> subsystem?)
>
> Or do you have any idea what else could lead to disapearance of all drives
> simultaniously? Other ata drives, via on-board ahci (C203) were not
> affected!
> UNfortunately, I haven't been able to record any kernel messages when that
> happened (3 times as far as I remember, no occurence since abandoning
> unionfs
> yet)

This doesn't seem like an mps driver problem to me, but maybe someone else
here can help more than I can. I can't think of anything that might be
causing your drives to disappear. It would help if you could get some kernel
logs when this happens.

>
> Thanks,
>
> -harry