> From: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Sent: Wednesday, October 26, 2022 2:12 AM
> +/*
> + * This iterator travels over spans in an interval tree. It does not return
> + * nodes but classifies each span as either a hole, where no nodes intersect,
> or
> + * a used, which is fully covered by nodes. Each iteration step toggles
> between
> + * hole and used until the entire range is covered. The returned spans
> always
> + * fully cover the requested range.
> + *
> + * The iterator is greedy, it always returns the largest hole or used possible,
> + * consolidating all consecutive nodes.
> + *
> + * Only is_hole, start_hole/used and last_hole/used are part of the external
> + * interface.
slightly better readability if moving this sentence into the structure as
the break line
> +void interval_tree_span_iter_advance(struct interval_tree_span_iter *iter,
> + struct rb_root_cached *itree,
> + unsigned long new_index)
> +{
> + if (iter->is_hole == -1)
> + return;
> +
> + iter->first_index = new_index;
> + if (new_index == iter->last_index) {
> + iter->is_hole = -1;
> + return;
> + }
> +
> + /* Rely on the union aliasing hole/used */
> + if (iter->start_hole <= new_index && new_index <= iter->last_hole) {
"<=" to "<"
> + iter->start_hole = new_index;
> + return;
> + }
> + if (new_index == iter->last_hole + 1)
> + interval_tree_span_iter_next(iter);
> + else
> + interval_tree_span_iter_first(iter, itree, new_index,
> + iter->last_index);
> +}
> +EXPORT_SYMBOL_GPL(interval_tree_span_iter_advance);
> +#endif
Apart from those,
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
