Commit fd103ffc authored by Amery Hung's avatar Amery Hung Committed by Martin KaFai Lau
Browse files

bpf: Convert bpf_selem_link_map to failable 



To prepare for changing bpf_local_storage_map_bucket::lock to rqspinlock,
convert bpf_selem_link_map() to failable. It still always succeeds and
returns 0 until the change happens. No functional change.

Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarAmery Hung <ameryhung@gmail.com>
Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20260205222916.1788211-4-ameryhung@gmail.com
parent 1b7e0cae

include/linux/bpf_local_storage.h

+3 −3
Original line number Diff line number Diff line
@@ -178,7 +178,7 @@ void bpf_selem_link_storage_nolock(struct bpf_local_storage *local_storage, 


void bpf_selem_unlink(struct bpf_local_storage_elem *selem, bool reuse_now);



void bpf_selem_link_map(struct bpf_local_storage_map *smap,

int bpf_selem_link_map(struct bpf_local_storage_map *smap,

		       struct bpf_local_storage *local_storage,

		       struct bpf_local_storage_elem *selem);

kernel/bpf/bpf_local_storage.c

+5 −3
Original line number Diff line number Diff line
@@ -365,7 +365,7 @@ static void bpf_selem_unlink_map_nolock(struct bpf_local_storage_elem *selem) 
	hlist_del_init_rcu(&selem->map_node);

}



void bpf_selem_link_map(struct bpf_local_storage_map *smap,

int bpf_selem_link_map(struct bpf_local_storage_map *smap,

		       struct bpf_local_storage *local_storage,

		       struct bpf_local_storage_elem *selem)

{
@@ -376,6 +376,8 @@ void bpf_selem_link_map(struct bpf_local_storage_map *smap, 
	raw_spin_lock_irqsave(&b->lock, flags);

	hlist_add_head_rcu(&selem->map_node, &b->list);

	raw_spin_unlock_irqrestore(&b->lock, flags);



	return 0;

}



static void bpf_selem_link_map_nolock(struct bpf_local_storage_map_bucket *b,

net/core/bpf_sk_storage.c

+8 −1
Original line number Diff line number Diff line
@@ -191,7 +191,14 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) 
		}



		if (new_sk_storage) {

			bpf_selem_link_map(smap, new_sk_storage, copy_selem);

			ret = bpf_selem_link_map(smap, new_sk_storage, copy_selem);

			if (ret) {

				bpf_selem_free(copy_selem, true);

				atomic_sub(smap->elem_size,

					   &newsk->sk_omem_alloc);

				bpf_map_put(map);

				goto out;

			}

			bpf_selem_link_storage_nolock(new_sk_storage, copy_selem);

		} else {

			ret = bpf_local_storage_alloc(newsk, smap, copy_selem, GFP_ATOMIC);