Re: [PATCH v6 10/13] xfs: iomap COW-based atomic write support

John Garry
2025-03-17T14:57:12Z

On 17/03/2025 14:20, Ritesh Harjani (IBM) wrote:
>> And, as mentioned earlier, it is ok to use REQ_ATOMIC method on an
>> unwritten extent.
>>
>>> I am guessing this is kept intentional?
>>>
>> Yes
> Thanks, John for addressing the queries. It would be helpful to include
> this information in the commit message as well then right? Otherwise
> IMO, the original commit message looks incomplete.

ok, fine. I am just worried that these commit messages become too wordy.
But, if people want this info, then I can provide it.

>
> Maybe we can add this too?
> =========================
> This patch adds CoW based atomic write support which will be used as a
> SW fallback in following scenarios:
>
> - All append write scenarios.
> - Any new writes on the region containing holes.

but only for > 1x block.

if we must be able to alloc at least a block :)

> - Writes to any misaligned regions
> - Writes to discontiguous extents.

ok, fine

>
>
> <original commit msg snip>
> =========================
> In cases of an atomic write covering misaligned or discontiguous disk
> blocks, we will use a CoW-based method to issue the atomic write.

sure

Thanks,
John