anycast: Some RCU conversions

- dev_get_by_flags() changed to dev_get_by_flags_rcu()

- ipv6_sock_ac_join() dont touch dev & idev refcounts
- ipv6_sock_ac_drop() dont touch dev & idev refcounts
- ipv6_sock_ac_close() dont touch dev & idev refcounts
- ipv6_dev_ac_dec() dount touch idev refcount
- ipv6_chk_acast_addr() dont touch idev refcount

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 9 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index c8d127718ff1..6f330cee79a6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -803,35 +803,31 @@ struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
 EXPORT_SYMBOL(dev_getfirstbyhwtype);
 
 /**
- *      dev_get_by_flags - find any device with given flags
+ *      dev_get_by_flags_rcu - 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. The device returned has
- *      had a reference added and the pointer is safe until the user calls
- *      dev_put to indicate they have finished with it.
+ *      is not found or a pointer to the device. Must be called inside
+ *      rcu_read_lock(), and result refcount is unchanged.
  */
 
-struct net_device *dev_get_by_flags(struct net *net, unsigned short if_flags,
+struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
                                     unsigned short mask)
 {
         struct net_device *dev, *ret;
 
         ret = NULL;
-        rcu_read_lock();
         for_each_netdev_rcu(net, dev) {
                 if (((dev->flags ^ if_flags) & mask) == 0) {
-                        dev_hold(dev);
                         ret = dev;
                         break;
                 }
         }
-        rcu_read_unlock();
         return ret;
 }
-EXPORT_SYMBOL(dev_get_by_flags);
+EXPORT_SYMBOL(dev_get_by_flags_rcu);
 
 /**
  *      dev_valid_name - check if name is okay for network device