mounting 4k blocksize on e.g. 64k hosts

[Ian Kent]

On 7/12/24 15:25, Gao Xiang wrote:
> Hi Ian,
>
> On 2024/12/7 09:09, Ian Kent wrote:
>> On 7/12/24 04:21, Gao Xiang wrote:
>>>
>>>
>>> On 2024/12/7 04:10, Colin Walters wrote:
>>>> On Fri, Dec 6, 2024, at 2:46 PM, Gao Xiang wrote:
>>>>
>>>>> Did you try upstream kernels? It's already supported upstream
>>>>> since Linux 6.4.
>>>>
>>>> Sorry, my bad. (It should have occurred to me to check, but this 
>>>> one popped back up on my radar when I'm trying to do several other 
>>>> things at the same time).
>>>>
>>>> Anyways looks like the fix specifically was 
>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d3c4bdcc756e60b95365c66ff58844ce75d1c8f8 
>>>> ?
>>>
>>> Yes, although it has been supported for nearly two
>>> years, but there are still many dependencies
>>> against RHEL 9 kernel (5.14) codebase.
>>>
>>>>
>>>>> I think RHEL 9 is lacking of many features.
>>>>
>>>> Yes, but I'll try to argue for refresh for 9.6. Thanks!
>>>> (Just tried to cherry pick that one myself, some conflicts but 
>>>> looks tractable)
>>>
>>> Actually, the PR below has been delayed for
>>> months:
>>> https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/4123 
>>>
>>
>> Indeed, yes.
>>
>>
>> I deferred it because I thought back porting the idmap type changes 
>> that came after
>>
>> 5.14 was more important and the above MR was conflicting with them.
>>
>> That was a large change and was difficult to get merged but it's done 
>> now.
>
> Thanks for the reply!
>
> Yeah, I thought it seems to be delayed due to some
> other high priority stuffs, but keep the codebase
> in line with Linux v6.1 or v6.6 is helpful to
> container use cases since I'm mainly working on
> this area these years, such as:
>  - large folios for better read performance;
>  - subpage block support (>= 512-byte blocks);
>  - FSDAX for page cache sharing into VMs;
>  - advanced compression features;
>  - and more.

I understand but right now I just want to get that original merge 
request merged.


Although, now I'm back to it, and we have a request for something 
specific, it may

go further than 5.19. Equally, back porting feature requests will be 
much more straight

forward with our RHEL-9 erofs at 5.19 as a basis. We'll need to wait and 
see what time

we have available and what the magnitude of the changes are for the 
request. Whether

we have tests available for user space and kernel space is a factor as 
well because

everything we support needs QE test coverage if at all possible.


We also need to focus on the fact that RHEL-10 is in need of work on 
erofs and is a

priority atm. I need to spend time there too.


And I should add I have been trying to find time to get an autofs 
release out that needs

to be back ported to both RHEL-9 and RHEL-10 (and I'm running out of 
time!) and a tricky

kernel fix to the autofs module as well, and that's not all I have going on.


Point being, please understand it's not as simple as just doing a back 
port, there is due

process to follow which also takes time.


Ian