bpf: Refactor some inode/task/sk storage functions for reuse
Refactor codes so that inode/task/sk storage implementation
can maximally share the same code. I also added some comments
in new function bpf_local_storage_unlink_nolock() to make
codes easy to understand. There is no functionality change.
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221026042845.672944-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index 94374d5..49884e7 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -48,10 +48,8 @@ static int bpf_sk_storage_del(struct sock *sk, struct bpf_map *map)
/* Called by __sk_destruct() & bpf_sk_storage_clone() */
void bpf_sk_storage_free(struct sock *sk)
{
- struct bpf_local_storage_elem *selem;
struct bpf_local_storage *sk_storage;
bool free_sk_storage = false;
- struct hlist_node *n;
rcu_read_lock();
sk_storage = rcu_dereference(sk->sk_bpf_storage);
@@ -60,24 +58,8 @@ void bpf_sk_storage_free(struct sock *sk)
return;
}
- /* Netiher the bpf_prog nor the bpf-map's syscall
- * could be modifying the sk_storage->list now.
- * Thus, no elem can be added-to or deleted-from the
- * sk_storage->list by the bpf_prog or by the bpf-map's syscall.
- *
- * It is racing with bpf_local_storage_map_free() alone
- * when unlinking elem from the sk_storage->list and
- * the map's bucket->list.
- */
raw_spin_lock_bh(&sk_storage->lock);
- hlist_for_each_entry_safe(selem, n, &sk_storage->list, snode) {
- /* Always unlink from map before unlinking from
- * sk_storage.
- */
- bpf_selem_unlink_map(selem);
- free_sk_storage = bpf_selem_unlink_storage_nolock(
- sk_storage, selem, true, false);
- }
+ free_sk_storage = bpf_local_storage_unlink_nolock(sk_storage);
raw_spin_unlock_bh(&sk_storage->lock);
rcu_read_unlock();
@@ -87,23 +69,12 @@ void bpf_sk_storage_free(struct sock *sk)
static void bpf_sk_storage_map_free(struct bpf_map *map)
{
- struct bpf_local_storage_map *smap;
-
- smap = (struct bpf_local_storage_map *)map;
- bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx);
- bpf_local_storage_map_free(smap, NULL);
+ bpf_local_storage_map_free(map, &sk_cache, NULL);
}
static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr)
{
- struct bpf_local_storage_map *smap;
-
- smap = bpf_local_storage_map_alloc(attr);
- if (IS_ERR(smap))
- return ERR_CAST(smap);
-
- smap->cache_idx = bpf_local_storage_cache_idx_get(&sk_cache);
- return &smap->map;
+ return bpf_local_storage_map_alloc(attr, &sk_cache);
}
static int notsupp_get_next_key(struct bpf_map *map, void *key,
