Re: [PATCH v9 01/10] iomap: stash iomap read ctx in the private field of iomap_iter

[Gao Xiang <hsiangkao@linux.alibaba.com>]

On 2025/11/19 17:12, Christoph Hellwig wrote:
> On Wed, Nov 19, 2025 at 02:17:07PM +0800, Gao Xiang wrote:
>> Hongbo didn't Cc you on this thread (I think he just added
>> recipients according to MAINTAINERS), but I know you played
>> a key role in iomap development, so I think you should be
>> in the loop about the iomap change too.
>>
>> Could you give some comments (maybe review) on this patch
>> if possible?  My own opinion is that if the first two
>> patches can be applied in the next cycle (6.19) (I understand
>> it will be too late for the whole feature into 6.19) , it
>> would be very helpful to us so at least the vfs iomap branch
>> won't be coupled anymore if the first two patch can be landed
>> in advance.
> 
> The patch itself looks fine.  But as Darrick said we really need
> to get our house in order for the iomap branch so that it actually
> works this close to the merge window.

Sigh.. I'm sorry to hear about that.

Anyway, personally I think patch 1 makes no change to iomap logic
(so I think it definitely does no harm to iomap stability), but
opens a chance for iomap users to control iter->private and pass
fs-specific contexts from iomap_begin to end (and patch 2 uses
this to get rid of kmap_to_page()). So honestly I'm eager to get
patches 1 and 2 merged.

However, it's really up to the iomap maintainers. Yet, if delayed
to the next development cycle, it might still need to resolve
cross-branch conflicts, and it could still causes some churn,
anyway...

Thanks,
Gao Xiang