diff options
| -rw-r--r-- | include/net/sock.h | 6 | ||||
| -rw-r--r-- | net/core/sock.c | 29 | ||||
| -rw-r--r-- | net/ipv4/ip_output.c | 1 | ||||
| -rw-r--r-- | net/ipv6/ip6_output.c | 1 |
4 files changed, 30 insertions, 7 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index 4bb1ff9fd15b..010e14a93c92 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1217,9 +1217,13 @@ static inline int skb_copy_to_page(struct sock *sk, char __user *from, static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk) { - sock_hold(sk); skb->sk = sk; skb->destructor = sock_wfree; + /* + * We used to take a refcount on sk, but following operation + * is enough to guarantee sk_free() wont free this sock until + * all in-flight packets are completed + */ atomic_add(skb->truesize, &sk->sk_wmem_alloc); } diff --git a/net/core/sock.c b/net/core/sock.c index 04e35eb2e736..06e26b77ad9e 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1008,7 +1008,7 @@ struct sock *sk_alloc(struct net *net, int family, gfp_t priority, } EXPORT_SYMBOL(sk_alloc); -void sk_free(struct sock *sk) +static void __sk_free(struct sock *sk) { struct sk_filter *filter; @@ -1031,6 +1031,17 @@ void sk_free(struct sock *sk) put_net(sock_net(sk)); sk_prot_free(sk->sk_prot_creator, sk); } + +void sk_free(struct sock *sk) +{ + /* + * We substract one from sk_wmem_alloc and can know if + * some packets are still in some tx queue. + * If not null, sock_wfree() will call __sk_free(sk) later + */ + if (atomic_dec_and_test(&sk->sk_wmem_alloc)) + __sk_free(sk); +} EXPORT_SYMBOL(sk_free); /* @@ -1071,7 +1082,10 @@ struct sock *sk_clone(const struct sock *sk, const gfp_t priority) newsk->sk_backlog.head = newsk->sk_backlog.tail = NULL; atomic_set(&newsk->sk_rmem_alloc, 0); - atomic_set(&newsk->sk_wmem_alloc, 0); + /* + * sk_wmem_alloc set to one (see sk_free() and sock_wfree()) + */ + atomic_set(&newsk->sk_wmem_alloc, 1); atomic_set(&newsk->sk_omem_alloc, 0); skb_queue_head_init(&newsk->sk_receive_queue); skb_queue_head_init(&newsk->sk_write_queue); @@ -1175,12 +1189,18 @@ void __init sk_init(void) void sock_wfree(struct sk_buff *skb) { struct sock *sk = skb->sk; + int res; /* In case it might be waiting for more memory. */ - atomic_sub(skb->truesize, &sk->sk_wmem_alloc); + res = atomic_sub_return(skb->truesize, &sk->sk_wmem_alloc); if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) sk->sk_write_space(sk); - sock_put(sk); + /* + * if sk_wmem_alloc reached 0, we are last user and should + * free this sock, as sk_free() call could not do it. + */ + if (res == 0) + __sk_free(sk); } EXPORT_SYMBOL(sock_wfree); @@ -1819,6 +1839,7 @@ void sock_init_data(struct socket *sock, struct sock *sk) sk->sk_stamp = ktime_set(-1L, 0); atomic_set(&sk->sk_refcnt, 1); + atomic_set(&sk->sk_wmem_alloc, 1); atomic_set(&sk->sk_drops, 0); } EXPORT_SYMBOL(sock_init_data); diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 9248d2807ba6..247026282669 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -498,7 +498,6 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) BUG_ON(frag->sk); if (skb->sk) { - sock_hold(skb->sk); frag->sk = skb->sk; frag->destructor = sock_wfree; truesizes += frag->truesize; diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index db6c7224a862..7c76e3d18215 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -680,7 +680,6 @@ static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) BUG_ON(frag->sk); if (skb->sk) { - sock_hold(skb->sk); frag->sk = skb->sk; frag->destructor = sock_wfree; truesizes += frag->truesize; |