decnet: RCU conversion and get rid of dev_base_lock

While tracking dev_base_lock users, I found decnet used it in
dnet_select_source(), but for a wrong purpose:

Writers only hold RTNL, not dev_base_lock, so readers must use RCU if
they cannot use RTNL.

Adds an rcu_head in struct dn_ifaddr and handle proper RCU management.

Adds __rcu annotation in dn_route as well.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
index a085dbcf5c7f..602dade7e9a3 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -391,7 +391,7 @@ int dn_neigh_router_hello(struct sk_buff *skb)
                 write_lock(&neigh->lock);
 
                 neigh->used = jiffies;
-                dn_db = (struct dn_dev *)neigh->dev->dn_ptr;
+                dn_db = rcu_dereference(neigh->dev->dn_ptr);
 
                 if (!(neigh->nud_state & NUD_PERMANENT)) {
                         neigh->updated = jiffies;