Re: [PATCH] ext4: flag as supporting buffered async reads

From: Jens Axboe
Date: Wed Aug 26 2020 - 21:54:33 EST


On 8/25/20 8:18 AM, Jens Axboe wrote:
> On 8/24/20 4:56 AM, Jens Axboe wrote:
>> On 8/22/20 9:48 AM, Jens Axboe wrote:
>>> On 8/22/20 8:33 AM, Theodore Y. Ts'o wrote:
>>>> On Fri, Aug 21, 2020 at 03:26:35PM -0600, Jens Axboe wrote:
>>>>>>>> Resending this one, as I've been carrying it privately since May. The
>>>>>>>> necessary bits are now upstream (and XFS/btrfs equiv changes as well),
>>>>>>>> please consider this one for 5.9. Thanks!
>>>>>>>
>>>>>>> The necessary commit only hit upstream as of 5.9-rc1, unless I'm
>>>>>>> missing something? It's on my queue to send to Linus once I get my
>>>>>>> (late) ext4 primary pull request for 5.9.
>>>>>>
>>>>>> Right, it went in at the start of the merge window for 5.9. Thanks Ted!
>>>>>
>>>>> Didn't see it in the queue that just sent in, is it still queued up?
>>>>
>>>> It wasn't in the queue which I queued up because that was based on
>>>> 5.8-rc4. Linus was a bit grumpy (fairly so) because it was late, and
>>>> that's totally on me.
>>>>
>>>> He has said that he's going to start ignoring pull requests that
>>>> aren't fixes only if this becomes a pattern, so while I can send him
>>>> another pull request which will just have that one change, there are
>>>> no guarantees he's going to take it at this late date.
>>>>
>>>> Sorry, when you sent me the commit saying that the changes that were
>>>> needed were already upstream on August 3rd, I thought that meant that
>>>> they were aready in Linus's tree. I should have checked and noticed
>>>> that that in fact "ext4: flag as supporting buffered async reads"
>>>> wasn't compiling against Linus's upstream tree, so I didn't realize
>>>> this needed to be handled as a special case during the merge window.
>>>
>>> Well to be honest, this kind of sucks. I've been posting it since May,
>>> and the ideal approach would have been to just ack it and I could have
>>> carried it in my tree. That's what we did for btrfs and XFS, both of
>>> which have it.
>>>
>>> The required patches *were* upstreamed on August 3rd, which is why I
>>> mentioned that. But yes, not in 5.8 or earlier, of course.
>>>
>>> So I suggest that you either include it for the next pull request for
>>> Linus, or that I put it in with your ack. Either is fine with me. I'd
>>> consider this a "dropping the ball" kind of thing, it's not like the
>>> patch hasn't been in linux-next or hasn't been ready for months. This
>>> isn't some "oh I wrote this feature after the merge window" event. It'd
>>> be a real shame to ship 5.9 and ext4 not have support for the more
>>> efficient async buffered reads, imho, especially since the two other
>>> major local file systems already have it.
>>>
>>> Let me know what you think.
>>
>> Ted, can you make a call on this, please? It's now post -rc2. Let's
>> get this settled and included, one way or another.
>
> Daily ping on this one...

And again. Ted, not sure how to make any progress with this, to be
honest, it's like pounding sand.

--
Jens Axboe