ipv6: drop useless rcu_read_lock() in anycast

These code is now protected by rtnl lock, rcu read lock
is useless now.

Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 16 insertions, 20 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ae721f53739e..ee38b948d9a0 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2083,8 +2083,8 @@ void __dev_remove_pack(struct packet_type *pt);
 void dev_add_offload(struct packet_offload *po);
 void dev_remove_offload(struct packet_offload *po);
 
-struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short flags,
-                                        unsigned short mask);
+struct net_device *__dev_get_by_flags(struct net *net, unsigned short flags,
+                                      unsigned short mask);
 struct net_device *dev_get_by_name(struct net *net, const char *name);
 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name);
 struct net_device *__dev_get_by_name(struct net *net, const char *name);
diff --git a/net/core/dev.c b/net/core/dev.c
index b3d6dbc0c696..e916ba8caccf 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -897,23 +897,25 @@ struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
 EXPORT_SYMBOL(dev_getfirstbyhwtype);
 
 /**
- *      dev_get_by_flags_rcu - find any device with given flags
+ *      __dev_get_by_flags - find any device with given flags
  *      @net: the applicable net namespace
  *      @if_flags: IFF_* values
  *      @mask: bitmask of bits in if_flags to check
  *
  *      Search for any interface with the given flags. Returns NULL if a device
  *      is not found or a pointer to the device. Must be called inside
- *      rcu_read_lock(), and result refcount is unchanged.
+ *      rtnl_lock(), and result refcount is unchanged.
  */
 
-struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
-                                    unsigned short mask)
+struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
+                                      unsigned short mask)
 {
         struct net_device *dev, *ret;
 
+        ASSERT_RTNL();
+
         ret = NULL;
-        for_each_netdev_rcu(net, dev) {
+        for_each_netdev(net, dev) {
                 if (((dev->flags ^ if_flags) & mask) == 0) {
                         ret = dev;
                         break;
@@ -921,7 +923,7 @@ struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags
         }
         return ret;
 }
-EXPORT_SYMBOL(dev_get_by_flags_rcu);
+EXPORT_SYMBOL(__dev_get_by_flags);
 
 /**
  *      dev_valid_name - check if name is okay for network device
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index ff2de7d9d8e6..3b0429bc6b5a 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -78,7 +78,6 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
         pac->acl_addr = *addr;
 
         rtnl_lock();
-        rcu_read_lock();
         if (ifindex == 0) {
                 struct rt6_info *rt;
 
@@ -91,11 +90,11 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
                         goto error;
                 } else {
                         /* router, no matching interface: just pick one */
-                        dev = dev_get_by_flags_rcu(net, IFF_UP,
-                                                   IFF_UP | IFF_LOOPBACK);
+                        dev = __dev_get_by_flags(net, IFF_UP,
+                                                 IFF_UP | IFF_LOOPBACK);
                 }
         } else
-                dev = dev_get_by_index_rcu(net, ifindex);
+                dev = __dev_get_by_index(net, ifindex);
 
         if (dev == NULL) {
                 err = -ENODEV;
@@ -137,7 +136,6 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
         }
 
 error:
-        rcu_read_unlock();
         rtnl_unlock();
         if (pac)
                 sock_kfree_s(sk, pac, sizeof(*pac));
@@ -174,11 +172,9 @@ int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
         spin_unlock_bh(&ipv6_sk_ac_lock);
 
         rtnl_lock();
-        rcu_read_lock();
-        dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
+        dev = __dev_get_by_index(net, pac->acl_ifindex);
         if (dev)
                 ipv6_dev_ac_dec(dev, &pac->acl_addr);
-        rcu_read_unlock();
         rtnl_unlock();
 
         sock_kfree_s(sk, pac, sizeof(*pac));
@@ -203,12 +199,11 @@ void ipv6_sock_ac_close(struct sock *sk)
 
         prev_index = 0;
         rtnl_lock();
-        rcu_read_lock();
         while (pac) {
                 struct ipv6_ac_socklist *next = pac->acl_next;
 
                 if (pac->acl_ifindex != prev_index) {
-                        dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
+                        dev = __dev_get_by_index(net, pac->acl_ifindex);
                         prev_index = pac->acl_ifindex;
                 }
                 if (dev)
@@ -216,7 +211,6 @@ void ipv6_sock_ac_close(struct sock *sk)
                 sock_kfree_s(sk, pac, sizeof(*pac));
                 pac = next;
         }
-        rcu_read_unlock();
         rtnl_unlock();
 }
 
@@ -341,7 +335,7 @@ int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr)
         return 0;
 }
 
-/* called with rcu_read_lock() */
+/* called with rtnl_lock() */
 static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
 {
         struct inet6_dev *idev = __in6_dev_get(dev);