Re: [PATCH bpf-next v7 1/2] bpf: htab: Split htab_elem_lru and htab_elem_pcpu off of htab_elem

[bot+bpf-ci]

> diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
> index 53c99fe4f176..5db11a21ce98 100644
> --- a/kernel/bpf/hashtab.c
> +++ b/kernel/bpf/hashtab.c

[ ... ]

> @@ -828,8 +861,12 @@ static __always_inline void *__htab_lru_map_lookup_elem(struct bpf_map *map,
>  	struct htab_elem *l = __htab_map_lookup_elem(map, key);
>
>  	if (l) {
> -		if (mark)
> -			bpf_lru_node_set_ref(&l->lru_node);
> +		if (mark) {
> +			struct htab_elem_lru *l_lru =
> +				container_of(l, struct htab_elem_lru, elem);
> +
> +			bpf_lru_node_set_ref(&l_lru->lru_node);
> +		}
>  		return htab_elem_value(l, map->key_size);
>  	}
>

[ ... ]

> @@ -1310,16 +1349,19 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value,
>
>  static void htab_lru_push_free(struct bpf_htab *htab, struct htab_elem *elem)
>  {
> +	struct htab_elem_lru *l = container_of(elem, struct htab_elem_lru, elem);
> +
>  	check_and_cancel_fields(htab, elem);
>  	bpf_map_dec_elem_count(&htab->map);
> -	bpf_lru_push_free(&htab->lru, &elem->lru_node);
> +	bpf_lru_push_free(&htab->lru, &l->lru_node);
>  }
>

[ ... ]

> @@ -1500,15 +1543,18 @@ static long __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
>  		goto err;
>
>  	if (l_old) {
> -		bpf_lru_node_set_ref(&l_old->lru_node);
> +		struct htab_elem_lru *l_old_lru =
> +			container_of(l_old, struct htab_elem_lru, elem);
> +
> +		bpf_lru_node_set_ref(&l_old_lru->lru_node);
>
>  		/* per-cpu hash map can update value in-place */
>  		pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),

[ ... ]

> @@ -2505,7 +2551,10 @@ static void *htab_lru_percpu_map_lookup_elem(struct bpf_map *map, void *key)
>  	struct htab_elem *l = __htab_map_lookup_elem(map, key);
>
>  	if (l) {
> -		bpf_lru_node_set_ref(&l->lru_node);
> +		struct htab_elem_lru *l_lru =
> +			container_of(l, struct htab_elem_lru, elem);
> +
> +		bpf_lru_node_set_ref(&l_lru->lru_node);
>  		return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
>  	}
>
> @@ -2521,7 +2570,10 @@ static void *htab_lru_percpu_map_lookup_percpu_elem(struct bpf_map *map, void *k
>
>  	l = __htab_map_lookup_elem(map, key);
>  	if (l) {
> -		bpf_lru_node_set_ref(&l->lru_node);
> +		struct htab_elem_lru *l_lru =
> +			container_of(l, struct htab_elem_lru, elem);
> +
> +		bpf_lru_node_set_ref(&l_lru->lru_node);
>  		return per_cpu_ptr(htab_elem_get_ptr(l, map->key_size), cpu);
>  	}
>

This isn't a bug, but would a small helper keep these call sites to one
line, matching the pcpu accessors this patch adds? Each site now repeats
the same container_of(l, struct htab_elem_lru, elem) boilerplate followed
by bpf_lru_node_set_ref(). The patch adds htab_elem_get_ptr_to_pptr() and
htab_elem_set_ptr_to_pptr() for the pcpu variant, but open-codes the
container_of for the LRU variant at every site.


---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md

CI run summary: https://github.com/kernel-patches/bpf/actions/runs/36441357391