Re: bcachefs page fault oops after device evacuate/remove and unmount

[Kent Overstreet]

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.