[PATCH][net-next] net/ipv6: compute anycast address hash only if dev is null

[Li RongQing]

avoid to compute the hash value if dev is not null, since
hash value is not used

Signed-off-by: Li RongQing <lirongq...@baidu.com>
---
 net/ipv6/anycast.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 94999058e110..a20e344486cb 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -433,15 +433,16 @@ static bool ipv6_chk_acast_dev(struct net_device *dev, 
const struct in6_addr *ad
 bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
                         const struct in6_addr *addr)
 {
-       unsigned int hash = inet6_acaddr_hash(net, addr);
        struct net_device *nh_dev;
        struct ifacaddr6 *aca;
        bool found = false;
+       unsigned int hash;
 
        rcu_read_lock();
        if (dev)
                found = ipv6_chk_acast_dev(dev, addr);
-       else
+       else {
+               hash = inet6_acaddr_hash(net, addr);
                hlist_for_each_entry_rcu(aca, &inet6_acaddr_lst[hash],
                                         aca_addr_lst) {
                        nh_dev = fib6_info_nh_dev(aca->aca_rt);
@@ -452,6 +453,7 @@ bool ipv6_chk_acast_addr(struct net *net, struct net_device 
*dev,
                                break;
                        }
                }
+       }
        rcu_read_unlock();
        return found;
 }
-- 
2.16.2