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

[Christoph Hellwig]

On Thu, Mar 20, 2025 at 09:49:44AM +0000, John Garry wrote:
>>> offset_fsb does not change, and logically cmap.br_startoff == end_fsb
>>> already, right?
>>
>> Afte unlocking and relocking the ilock the extent layout could have
>> changed.
>
> ok, understood. Maybe a comment will help understanding that.

Sure.  As said this was just intended as draft code.  Maybe factoring
out a helper or two would also be useful, although I couldn't think
of a really obvious one.