From mboxrd@z Thu Jan 1 00:00:00 1970 From: YOSHIFUJI Hideaki Subject: [PATCH net-next (V4) 04/11] ndisc: Introduce __ipv6_neigh_lookup_noref(). Date: Fri, 18 Jan 2013 07:53:22 +0900 Message-ID: <50F880E2.4080303@linux-ipv6.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Cc: yoshfuji@linux-ipv6.org, xiyou.wangcong@gmail.com To: davem@davemloft.net, netdev@vger.kernel.org Return-path: Received: from 94.43.138.210.xn.2iij.net ([210.138.43.94]:44758 "EHLO mail.st-paulia.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754284Ab3AQWxX (ORCPT ); Thu, 17 Jan 2013 17:53:23 -0500 Sender: netdev-owner@vger.kernel.org List-ID: This function, which looks up neighbour entry for an IPv6 address without touching refcnt, will be used for patches to remove dependency on rt->n (neighbour entry in rt6_info). Signed-off-by: YOSHIFUJI Hideaki --- include/net/ndisc.h | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/include/net/ndisc.h b/include/net/ndisc.h index bbc938e..ec48f42 100644 --- a/include/net/ndisc.h +++ b/include/net/ndisc.h @@ -148,14 +148,13 @@ static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, _ (p32[3] * hash_rnd[3])); } -static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey) +static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey) { struct neigh_hash_table *nht; const u32 *p32 = pkey; struct neighbour *n; u32 hash_val; - rcu_read_lock_bh(); nht = rcu_dereference_bh(nd_tbl.nht); hash_val = ndisc_hashfn(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift); for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]); @@ -164,12 +163,21 @@ static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, cons u32 *n32 = (u32 *) n->primary_key; if (n->dev == dev && ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) | - (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0) { - if (!atomic_inc_not_zero(&n->refcnt)) - n = NULL; - break; - } + (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0) + return n; } + + return NULL; +} + +static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey) +{ + struct neighbour *n; + + rcu_read_lock_bh(); + n = __ipv6_neigh_lookup_noref(dev, pkey); + if (n && !atomic_inc_not_zero(&n->refcnt)) + n = NULL; rcu_read_unlock_bh(); return n; -- 1.7.9.5