Re: [PATCH v5 01/10] iomap: factor out iomap length helper

Darrick J. Wong
2025-02-05T18:49:37Z

On Wed, Feb 05, 2025 at 08:58:12AM -0500, Brian Foster wrote:
> In preparation to support more granular iomap iter advancing, factor
> the pos/len values as parameters to length calculation.
>
> Signed-off-by: Brian Foster <bfoster@redhat.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Looks ok,
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
> include/linux/iomap.h | 23 +++++++++++++++++++----
> 1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 75bf54e76f3b..f5ca71ac2fa2 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -231,18 +231,33 @@ struct iomap_iter {
> int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops);
>
> /**
> - * iomap_length - length of the current iomap iteration
> + * iomap_length_trim - trimmed length of the current iomap iteration
> * @iter: iteration structure
> + * @pos: File position to trim from.
> + * @len: Length of the mapping to trim to.
> *
> - * Returns the length that the operation applies to for the current iteration.
> + * Returns a trimmed length that the operation applies to for the current
> + * iteration.
> */
> -static inline u64 iomap_length(const struct iomap_iter *iter)
> +static inline u64 iomap_length_trim(const struct iomap_iter *iter, loff_t pos,
> + u64 len)
> {
> u64 end = iter->iomap.offset + iter->iomap.length;
>
> if (iter->srcmap.type != IOMAP_HOLE)
> end = min(end, iter->srcmap.offset + iter->srcmap.length);
> - return min(iter->len, end - iter->pos);
> + return min(len, end - pos);
> +}
> +
> +/**
> + * iomap_length - length of the current iomap iteration
> + * @iter: iteration structure
> + *
> + * Returns the length that the operation applies to for the current iteration.
> + */
> +static inline u64 iomap_length(const struct iomap_iter *iter)
> +{
> + return iomap_length_trim(iter, iter->pos, iter->len);
> }
>
> /**
> --
> 2.48.1
>
>