Re: [PATCH v5 03/10] iomap: refactor iomap_iter() length check and tracepoint

Darrick J. Wong
2025-02-05T18:50:22Z

On Wed, Feb 05, 2025 at 08:58:14AM -0500, Brian Foster wrote:
> iomap_iter() checks iomap.length to skip individual code blocks not
> appropriate for the initial case where there is no mapping in the
> iter. To prepare for upcoming changes, refactor the code to jump
> straight to the ->iomap_begin() handler in the initial case and move
> the tracepoint to the top of the function so it always executes.
>
> 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

> ---
> fs/iomap/iter.c | 19 +++++++++++--------
> 1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/fs/iomap/iter.c b/fs/iomap/iter.c
> index 731ea7267f27..a2ae99fe6431 100644
> --- a/fs/iomap/iter.c
> +++ b/fs/iomap/iter.c
> @@ -73,7 +73,12 @@ int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops)
> {
> int ret;
>
> - if (iter->iomap.length && ops->iomap_end) {
> + trace_iomap_iter(iter, ops, _RET_IP_);
> +
> + if (!iter->iomap.length)
> + goto begin;
> +
> + if (ops->iomap_end) {
> ret = ops->iomap_end(iter->inode, iter->pos, iomap_length(iter),
> iter->processed > 0 ? iter->processed : 0,
> iter->flags, &iter->iomap);
> @@ -82,14 +87,12 @@ int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops)
> }
>
> /* advance and clear state from the previous iteration */
> - trace_iomap_iter(iter, ops, _RET_IP_);
> - if (iter->iomap.length) {
> - ret = iomap_iter_advance(iter, iter->processed);
> - iomap_iter_reset_iomap(iter);
> - if (ret <= 0)
> - return ret;
> - }
> + ret = iomap_iter_advance(iter, iter->processed);
> + iomap_iter_reset_iomap(iter);
> + if (ret <= 0)
> + return ret;
>
> +begin:
> ret = ops->iomap_begin(iter->inode, iter->pos, iter->len, iter->flags,
> &iter->iomap, &iter->srcmap);
> if (ret < 0)
> --
> 2.48.1
>
>