[PATCH v8 1/9] iomap: stash iomap read ctx in the private field of iomap_iter
Gao Xiang
hsiangkao at linux.alibaba.com
Sun Nov 16 22:54:43 AEDT 2025
On 2025/11/14 17:55, 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>
LGTM, and I think the case 2) is useful even without
the main feature:
Reviewed-by: Gao Xiang <hsiangkao at linux.alibaba.com>
Thanks,
Gao Xiang
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