From dbfc4fb7d578d4f224faa6b60deb40804dfdc1b1 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Sat, 6 Dec 2014 19:19:42 +0100 Subject: dst: no need to take reference on DST_NOCACHE dsts Since commit f8864972126899 ("ipv4: fix dst race in sk_dst_get()") DST_NOCACHE dst_entries get freed by RCU. So there is no need to get a reference on them when we are in rcu protected sections. Cc: Eric Dumazet Cc: Julian Anastasov Signed-off-by: Hannes Frederic Sowa Reviewed-by: Julian Anastasov Signed-off-by: David S. Miller --- net/core/dst.c | 24 ------------------------ 1 file changed, 24 deletions(-) (limited to 'net/core/dst.c') diff --git a/net/core/dst.c b/net/core/dst.c index a028409ee438..e956ce6d1378 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -327,30 +327,6 @@ void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old) } EXPORT_SYMBOL(__dst_destroy_metrics_generic); -/** - * __skb_dst_set_noref - sets skb dst, without a reference - * @skb: buffer - * @dst: dst entry - * @force: if force is set, use noref version even for DST_NOCACHE entries - * - * Sets skb dst, assuming a reference was not taken on dst - * skb_dst_drop() should not dst_release() this dst - */ -void __skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst, bool force) -{ - WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); - /* If dst not in cache, we must take a reference, because - * dst_release() will destroy dst as soon as its refcount becomes zero - */ - if (unlikely((dst->flags & DST_NOCACHE) && !force)) { - dst_hold(dst); - skb_dst_set(skb, dst); - } else { - skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF; - } -} -EXPORT_SYMBOL(__skb_dst_set_noref); - /* Dirty hack. We did it in 2.2 (in __dst_free), * we have _very_ good reasons not to repeat * this mistake in 2.3, but we have no choice -- cgit v1.2.3