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From:   Daniel J Blueman <daniel@quora.org>
Date:   Thu, 30 Nov 2023 21:58:42 -0500
Message-ID: <CAMVG2stS=W4d+XxxHzLb+31Dn7pnqjTE25pDwLSv_14rcqsc-g@mail.gmail.com>
Subject: Re: bcachefs page fault oops after device evacuate/remove and unmount
To:     Kent Overstreet <kent.overstreet@linux.dev>
Cc:     Linux Kernel <linux-kernel@vger.kernel.org>,
        linux-bcachefs@vger.kernel.org
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On Thu, 30 Nov 2023 at 20:50, Kent Overstreet <kent.overstreet@linux.dev> wrote:
>
> On Thu, Nov 30, 2023 at 08:47:33PM -0500, Daniel J Blueman wrote:
> > Hi Kent et al,
> >
> > On upstream bcachefs (master @ evilpiepirate.org/git/bcachefs.git) SHA
> > f8a1ba26, I was able to develop a minimal reproducer [1] for a page
> > not present oops I can provoke [2]. It appears we need further
> > synchronisation during unmount.
> >
> > Let me know when there is a patch I can test, or for debug.
>
> There was a device removal that was just fixed, I've already sent the
> pull request to Linus but in the meantime try this branch:
>
> https://evilpiepirate.org/git/bcachefs.git/log/?h=bcachefs-for-upstream
>
> If you still hit it, I'll turn your reproducer into a ktest test and
> hunt it down.

This did reproduce on the second cycle on bcachefs-for-upstream SHA
415e5107b0dc; let me know if you can't trigger it and I'll make some
adjustments.

Thanks,
  Dan
-- 
Daniel J Blueman