diff options
| -rw-r--r-- | include/linux/skbuff.h | 14 | ||||
| -rw-r--r-- | net/unix/af_unix.c | 11 |
2 files changed, 22 insertions, 3 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 3d13a4b717e9..ca8806b69388 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1822,6 +1822,18 @@ static inline __u32 skb_queue_len(const struct sk_buff_head *list_) } /** + * skb_queue_len_lockless - get queue length + * @list_: list to measure + * + * Return the length of an &sk_buff queue. + * This variant can be used in lockless contexts. + */ +static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_) +{ + return READ_ONCE(list_->qlen); +} + +/** * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head * @list: queue to initialize * @@ -2026,7 +2038,7 @@ static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) { struct sk_buff *next, *prev; - list->qlen--; + WRITE_ONCE(list->qlen, list->qlen - 1); next = skb->next; prev = skb->prev; skb->next = skb->prev = NULL; diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 321af97c7bbe..62c12cb5763e 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -189,11 +189,17 @@ static inline int unix_may_send(struct sock *sk, struct sock *osk) return unix_peer(osk) == NULL || unix_our_peer(sk, osk); } -static inline int unix_recvq_full(struct sock const *sk) +static inline int unix_recvq_full(const struct sock *sk) { return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; } +static inline int unix_recvq_full_lockless(const struct sock *sk) +{ + return skb_queue_len_lockless(&sk->sk_receive_queue) > + READ_ONCE(sk->sk_max_ack_backlog); +} + struct sock *unix_peer_get(struct sock *s) { struct sock *peer; @@ -1758,7 +1764,8 @@ restart_locked: * - unix_peer(sk) == sk by time of get but disconnected before lock */ if (other != sk && - unlikely(unix_peer(other) != sk && unix_recvq_full(other))) { + unlikely(unix_peer(other) != sk && + unix_recvq_full_lockless(other))) { if (timeo) { timeo = unix_wait_for_peer(other, timeo); |