Commit 41b3caa7 authored by Gilad Naaman's avatar Gilad Naaman Committed by Jakub Kicinski
Browse files

neighbour: Add hlist_node to struct neighbour 



Add a doubly-linked node to neighbours, so that they
can be deleted without iterating the entire bucket they're in.

Signed-off-by: default avatarGilad Naaman <gnaaman@drivenets.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241107160444.2913124-2-gnaaman@drivenets.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5e5be503

include/net/neighbour.h

+2 −0
Original line number Diff line number Diff line
@@ -136,6 +136,7 @@ struct neigh_statistics { 


struct neighbour {

	struct neighbour __rcu	*next;

	struct hlist_node	hash;

	struct neigh_table	*tbl;

	struct neigh_parms	*parms;

	unsigned long		confirmed;
@@ -191,6 +192,7 @@ struct pneigh_entry { 


struct neigh_hash_table {

	struct neighbour __rcu	**hash_buckets;

	struct hlist_head	*hash_heads;

	unsigned int		hash_shift;

	__u32			hash_rnd[NEIGH_NUM_HASH_RND];

	struct rcu_head		rcu;

net/core/neighbour.c

+19 −1
Original line number Diff line number Diff line
@@ -216,6 +216,7 @@ static bool neigh_del(struct neighbour *n, struct neighbour __rcu **np, 
		neigh = rcu_dereference_protected(n->next,

						  lockdep_is_held(&tbl->lock));

		rcu_assign_pointer(*np, neigh);

		hlist_del_rcu(&n->hash);

		neigh_mark_dead(n);

		retval = true;

	}
@@ -402,6 +403,7 @@ static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev, 
			rcu_assign_pointer(*np,

				   rcu_dereference_protected(n->next,

						lockdep_is_held(&tbl->lock)));

			hlist_del_rcu(&n->hash);

			write_lock(&n->lock);

			neigh_del_timer(n);

			neigh_mark_dead(n);
@@ -529,20 +531,30 @@ static void neigh_get_hash_rnd(u32 *x) 


static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift)

{

	size_t hash_heads_size = (1 << shift) * sizeof(struct hlist_head);

	size_t size = (1 << shift) * sizeof(struct neighbour *);

	struct neigh_hash_table *ret;

	struct neighbour __rcu **buckets;

	struct hlist_head *hash_heads;

	struct neigh_hash_table *ret;

	int i;



	ret = kmalloc(sizeof(*ret), GFP_ATOMIC);

	if (!ret)

		return NULL;



	buckets = kvzalloc(size, GFP_ATOMIC);

	if (!buckets) {

		kfree(ret);

		return NULL;

	}

	hash_heads = kvzalloc(hash_heads_size, GFP_ATOMIC);

	if (!hash_heads) {

		kvfree(buckets);

		kfree(ret);

		return NULL;

	}

	ret->hash_buckets = buckets;

	ret->hash_heads = hash_heads;

	ret->hash_shift = shift;

	for (i = 0; i < NEIGH_NUM_HASH_RND; i++)

		neigh_get_hash_rnd(&ret->hash_rnd[i]);
@@ -556,6 +568,7 @@ static void neigh_hash_free_rcu(struct rcu_head *head) 
						    rcu);



	kvfree(nht->hash_buckets);

	kvfree(nht->hash_heads);

	kfree(nht);

}
@@ -592,6 +605,8 @@ static struct neigh_hash_table *neigh_hash_grow(struct neigh_table *tbl, 
						new_nht->hash_buckets[hash],

						lockdep_is_held(&tbl->lock)));

			rcu_assign_pointer(new_nht->hash_buckets[hash], n);

			hlist_del_rcu(&n->hash);

			hlist_add_head_rcu(&n->hash, &new_nht->hash_heads[hash]);

		}

	}
@@ -702,6 +717,7 @@ ___neigh_create(struct neigh_table *tbl, const void *pkey, 
			   rcu_dereference_protected(nht->hash_buckets[hash_val],

						     lockdep_is_held(&tbl->lock)));

	rcu_assign_pointer(nht->hash_buckets[hash_val], n);

	hlist_add_head_rcu(&n->hash, &nht->hash_heads[hash_val]);

	write_unlock_bh(&tbl->lock);

	neigh_dbg(2, "neigh %p is created\n", n);

	rc = n;
@@ -987,6 +1003,7 @@ static void neigh_periodic_work(struct work_struct *work) 
				rcu_assign_pointer(*np,

					rcu_dereference_protected(n->next,

						lockdep_is_held(&tbl->lock)));

				hlist_del_rcu(&n->hash);

				neigh_mark_dead(n);

				write_unlock(&n->lock);

				neigh_cleanup_and_release(n);
@@ -3116,6 +3133,7 @@ void __neigh_for_each_release(struct neigh_table *tbl, 
				rcu_assign_pointer(*np,

					rcu_dereference_protected(n->next,

						lockdep_is_held(&tbl->lock)));

				hlist_del_rcu(&n->hash);

				neigh_mark_dead(n);

			} else

				np = &n->next;