On 11/3/24 5:06 PM, Jens Axboe wrote:
> On 11/3/24 5:01 PM, Keith Busch wrote:
>> On Sun, Nov 03, 2024 at 04:53:27PM -0700, Jens Axboe wrote:
>>> On 11/3/24 4:47 PM, Andrew Marshall wrote:
>>>> I identified f4ce3b5d26ce149e77e6b8e8f2058aa80e5b034e as the likely
>>>> problematic commit simply by browsing git log. As indicated above;
>>>> reverting that atop 6.6.59 results in success. Since it is passing on
>>>> 6.11.6, I suspect there is some missing backport to 6.6.x, or some
>>>> other semantic merge conflict. Unfortunately I do not have a compact,
>>>> minimal reproducer, but can provide my large one (it is testing a
>>>> larger build process in a VM) if needed?there are some additional
>>>> details in the above-linked downstream bug report, though. I hope that
>>>> having identified the problematic commit is enough for someone with
>>>> more context to go off of. Happy to provide more information if
>>>> needed.
>>>
>>> Don't worry about not having a reproducer, having the backport commit
>>> pin pointed will do just fine. I'll take a look at this.
>>
>> I think stable is missing:
>>
>>   6b231248e97fc3 ("io_uring: consolidate overflow flushing")
> 
> I think you need to go back further than that, this one already
> unconditionally holds ->uring_lock around overflow flushing...

Took a look, it's this one:

commit 8d09a88ef9d3cb7d21d45c39b7b7c31298d23998
Author: Pavel Begunkov <asml.silence@gmail.com>
Date:   Wed Apr 10 02:26:54 2024 +0100

    io_uring: always lock __io_cqring_overflow_flush

Greg/stable, can you pick this one for 6.6-stable? It picks
cleanly.

For 6.1, which is the other stable of that age that has the backport,
the attached patch will do the trick.

With that, I believe it should be sorted. Hopefully that can make
6.6.60 and 6.1.116.

-- 
Jens Axboe