Commit af185d8c authored by Eric Dumazet's avatar Eric Dumazet Committed by Paolo Abeni
Browse files

raw: complete rcu conversion 



raw_diag_dump() can use rcu_read_lock() instead of read_lock()

Now the hashinfo lock is only used from process context,
in write mode only, we can convert it to a spinlock,
and we do not need to block BH anymore.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220620100509.3493504-1-eric.dumazet@gmail.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent f9aefd6b

include/net/raw.h

+2 −2
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ int raw_rcv(struct sock *, struct sk_buff *); 
#define RAW_HTABLE_SIZE	MAX_INET_PROTOS



struct raw_hashinfo {

	rwlock_t lock;

	spinlock_t lock;

	struct hlist_nulls_head ht[RAW_HTABLE_SIZE];

};
@@ -40,7 +40,7 @@ static inline void raw_hashinfo_init(struct raw_hashinfo *hashinfo) 
{

	int i;



	rwlock_init(&hashinfo->lock);

	spin_lock_init(&hashinfo->lock);

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

		INIT_HLIST_NULLS_HEAD(&hashinfo->ht[i], i);

}

net/ipv4/raw.c

+4 −4
Original line number Diff line number Diff line
@@ -95,10 +95,10 @@ int raw_hash_sk(struct sock *sk) 


	hlist = &h->ht[inet_sk(sk)->inet_num & (RAW_HTABLE_SIZE - 1)];



	write_lock_bh(&h->lock);

	spin_lock(&h->lock);

	__sk_nulls_add_node_rcu(sk, hlist);

	sock_set_flag(sk, SOCK_RCU_FREE);

	write_unlock_bh(&h->lock);

	spin_unlock(&h->lock);

	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);



	return 0;
@@ -109,10 +109,10 @@ void raw_unhash_sk(struct sock *sk) 
{

	struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;



	write_lock_bh(&h->lock);

	spin_lock(&h->lock);

	if (__sk_nulls_del_node_init_rcu(sk))

		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);

	write_unlock_bh(&h->lock);

	spin_unlock(&h->lock);

}

EXPORT_SYMBOL_GPL(raw_unhash_sk);

net/ipv4/raw_diag.c

+2 −2
Original line number Diff line number Diff line
@@ -156,7 +156,7 @@ static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 
	s_slot = cb->args[0];

	num = s_num = cb->args[1];



	read_lock(&hashinfo->lock);

	rcu_read_lock();

	for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {

		num = 0;
@@ -184,7 +184,7 @@ static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 
	}



out_unlock:

	read_unlock(&hashinfo->lock);

	rcu_read_unlock();



	cb->args[0] = slot;

	cb->args[1] = num;