svn commit: r308155 - in head/sys: amd64/conf cam cam/scsi conf dev/mps geom geom/part kern sys vm

[Conrad Meyer]

Hi Alan,

On Tue, Apr 18, 2017 at 12:02 PM, Alan Somers <asomers at freebsd.org> wrote:
> This change is causing panics when I try to create a zpool on an SSD.
>
> ... (reordered slightly)
>
> The
> offending line is the biotrack call in scsi_da.c at line 4172; bp is
> apparently null.  Could you please review this change and ensure that
> biotrack is appropriately guarded?

If it is valid for bp to be NULL in that path, then of course a NULL
guard needs to be added.

I'm a little confused on why or if it is valid for bp to be NULL in
that path.  You are the only one who has reported this since October
of last year.  Is it possible some other issue is now resulting in a
NULL bp?

> The SSD is obviously having problems; it fails UNMAP commands with
> ILLEGAL REQUEST, and then fails WRITE SAME with a timeout.

Well, that could definitely explain a weird error case.  Still,
shouldn't the CCB keep the bp associated through CCB completion?

Thanks,
Conrad