[PATCH net-next 7/7] rtnetlink: rtnl_have_link_slave_info doesn't need rtnl

[Florian Westphal]

it can be switched to rcu.
rtnl_link_slave_info_fill on the other hand does need it,
at least for now.  Add ASSERT_RTNL annotation as a reminder.

Signed-off-by: Florian Westphal <f...@strlen.de>
---
 net/core/rtnetlink.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 7af9774aec40..9fd48b437d64 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -524,11 +524,15 @@ static size_t rtnl_link_get_af_size(const struct 
net_device *dev,
 static bool rtnl_have_link_slave_info(const struct net_device *dev)
 {
        struct net_device *master_dev;
+       bool ret = false;
 
-       master_dev = netdev_master_upper_dev_get((struct net_device *) dev);
+       rcu_read_lock();
+
+       master_dev = netdev_master_upper_dev_get_rcu((struct net_device *) dev);
        if (master_dev && master_dev->rtnl_link_ops)
-               return true;
-       return false;
+               ret = true;
+       rcu_read_unlock();
+       return ret;
 }
 
 static int rtnl_link_slave_info_fill(struct sk_buff *skb,
@@ -539,6 +543,8 @@ static int rtnl_link_slave_info_fill(struct sk_buff *skb,
        struct nlattr *slave_data;
        int err;
 
+       ASSERT_RTNL();
+
        master_dev = netdev_master_upper_dev_get((struct net_device *) dev);
        if (!master_dev)
                return 0;
@@ -570,6 +576,8 @@ static int rtnl_link_info_fill(struct sk_buff *skb,
        struct nlattr *data;
        int err;
 
+       ASSERT_RTNL();
+
        if (!ops)
                return 0;
        if (nla_put_string(skb, IFLA_INFO_KIND, ops->kind) < 0)
@@ -600,6 +608,8 @@ static int rtnl_link_fill(struct sk_buff *skb, const struct 
net_device *dev)
        struct nlattr *linkinfo;
        int err = -EMSGSIZE;
 
+       ASSERT_RTNL();
+
        linkinfo = nla_nest_start(skb, IFLA_LINKINFO);
        if (linkinfo == NULL)
                goto out;
-- 
2.13.5