[PATCH v14 01/10] iomap: stash iomap read ctx in the private field of iomap_iter

Gao Xiang hsiangkao at linux.alibaba.com
Sat Jan 10 22:55:12 AEDT 2026


Hi Darrick,

On 2026/1/10 02:14, Darrick J. Wong wrote:
> On Fri, Jan 09, 2026 at 10:28:47AM +0000, Hongbo Li wrote:
>> It's useful to get filesystem-specific information using the
>> existing private field in the @iomap_iter passed to iomap_{begin,end}
>> for advanced usage for iomap buffered reads, which is much like the
>> current iomap DIO.
>>
>> For example, EROFS needs it to:
>>
>>   - implement an efficient page cache sharing feature, since iomap
>>     needs to apply to anon inode page cache but we'd like to get the
>>     backing inode/fs instead, so filesystem-specific private data is
>>     needed to keep such information;
>>
>>   - pass in both struct page * and void * for inline data to avoid
>>     kmap_to_page() usage (which is bogus).
>>
>> Signed-off-by: Hongbo Li <lihongbo22 at huawei.com>
>> Reviewed-by: Gao Xiang <hsiangkao at linux.alibaba.com>
> 
> This looks like a dead simple patch to allow iomap pagecache users to
> set iomap_iter::private, so no objections here:
> 
> Reviewed-by: "Darrick J. Wong" <djwong at kernel.org>

Thanks for the review!

Thanks,
Gao Xiang

> 
> --D
> 


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