Re: [PATCH RESEND 0/5] block: validate direct I/O memory alignment

[Jens Axboe <axboe@kernel.dk>]

On 7/30/26 7:25 AM, Thorsten Leemhuis wrote:
> On 7/30/26 13:26, Christoph Hellwig wrote:
>> On Wed, Jul 29, 2026 at 02:03:07PM -0600, Keith Busch wrote:
>>>>> Hi Jens, have you had a chance to look at this one yet? This addresses
>>>>> previous issues with certain device mappers under direct io.
>>>>
>>>> I they look fine, but at this point we should toss them into 7.3. Yes
>>>> I know there are regressions around this, but from 6.1x days. And the
>>>> series doesn't apply to the current block-7.2 anyway.
>>>
>>> This series is kind of old at this point, but yes, it's not fixing a new
>>> regression either. I'm okay if this goes to the next window, and I will
>>> handle the stable follow-up.
>>
>> Honestly, I think that'a a reall bad idea.  This is a regression in 6.18,
>> and while it took a while for people to hit this with their a little
>> more complicated lvm/md setups, it has stopped real systems from being
>> used.  We need to fix this ASAP.
> Thx for this, as I had been thinking along the same lines already and
> was still considering if I wanted to speak up.
> 
> 6.18 still qualifies as recent in my book, but YMMV. And it's not like
> people "took forever to notice"[1], as they reported this for a while
> now -- and there were a few attempts to fix this; it just took us some
> time to see the full problem (@Keith: many thx for that and the fixes
> for them). And some of the linked reports are quite recent, so people
> really hit this.
> 
> Sure, as always there is the risk that this will cause other, bigger
> regressions. Maybe that's why it's one of those situations where the
> right approach is "submit this separately to Linus and let him decide",
> unless of course he speaks up here.

Sorry that's nonsense, because how is Linus going to make that call if
we can't. It's on us/me to make that call. We're not first-timers around
here, we've been around and know how to make the call that we can stand
by.

-- 
Jens Axboe