bpf: hash: use atomic count

Preparing for removing global per-hashtable lock, so
the counter need to be defined as aotmic_t first.

Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
tom.leiming@gmail.com 2015-12-29 22:40:25 +08:00 committed by David S. Miller
parent 26a4d063b1
commit 6591f1e666

View file

@ -18,7 +18,7 @@ struct bpf_htab {
struct bpf_map map;
struct hlist_head *buckets;
raw_spinlock_t lock;
u32 count; /* number of elements in this hashtable */
atomic_t count; /* number of elements in this hashtable */
u32 n_buckets; /* number of hash buckets */
u32 elem_size; /* size of each element in bytes */
};
@ -106,7 +106,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
INIT_HLIST_HEAD(&htab->buckets[i]);
raw_spin_lock_init(&htab->lock);
htab->count = 0;
atomic_set(&htab->count, 0);
return &htab->map;
@ -256,7 +256,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
l_old = lookup_elem_raw(head, l_new->hash, key, key_size);
if (!l_old && unlikely(htab->count >= map->max_entries)) {
if (!l_old && unlikely(atomic_read(&htab->count) >= map->max_entries)) {
/* if elem with this 'key' doesn't exist and we've reached
* max_entries limit, fail insertion of new elem
*/
@ -284,7 +284,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
hlist_del_rcu(&l_old->hash_node);
kfree_rcu(l_old, rcu);
} else {
htab->count++;
atomic_inc(&htab->count);
}
raw_spin_unlock_irqrestore(&htab->lock, flags);
@ -319,7 +319,7 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key)
if (l) {
hlist_del_rcu(&l->hash_node);
htab->count--;
atomic_dec(&htab->count);
kfree_rcu(l, rcu);
ret = 0;
}
@ -339,7 +339,7 @@ static void delete_all_elements(struct bpf_htab *htab)
hlist_for_each_entry_safe(l, n, head, hash_node) {
hlist_del_rcu(&l->hash_node);
htab->count--;
atomic_dec(&htab->count);
kfree(l);
}
}