diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/dst.h | 33 | ||||
| -rw-r--r-- | include/net/sock.h | 2 |
2 files changed, 34 insertions, 1 deletions
diff --git a/include/net/dst.h b/include/net/dst.h index 0fb99a26e973..182b812d45e1 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -312,6 +312,39 @@ static inline void skb_dst_force(struct sk_buff *skb) } } +/** + * dst_hold_safe - Take a reference on a dst if possible + * @dst: pointer to dst entry + * + * This helper returns false if it could not safely + * take a reference on a dst. + */ +static inline bool dst_hold_safe(struct dst_entry *dst) +{ + if (dst->flags & DST_NOCACHE) + return atomic_inc_not_zero(&dst->__refcnt); + dst_hold(dst); + return true; +} + +/** + * skb_dst_force_safe - makes sure skb dst is refcounted + * @skb: buffer + * + * If dst is not yet refcounted and not destroyed, grab a ref on it. + */ +static inline void skb_dst_force_safe(struct sk_buff *skb) +{ + if (skb_dst_is_noref(skb)) { + struct dst_entry *dst = skb_dst(skb); + + if (!dst_hold_safe(dst)) + dst = NULL; + + skb->_skb_refdst = (unsigned long)dst; + } +} + /** * __skb_tunnel_rx - prepare skb for rx reinsert diff --git a/include/net/sock.h b/include/net/sock.h index f58132440d62..4c4b21c00828 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -799,7 +799,7 @@ void sk_stream_write_space(struct sock *sk); static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) { /* dont let skb dst not refcounted, we are going to leave rcu lock */ - skb_dst_force(skb); + skb_dst_force_safe(skb); if (!sk->sk_backlog.tail) sk->sk_backlog.head = skb; |