[net-next,02/26] net: add RCU variant to search for netdev_adjacent link

Submitted by Veaceslav Falico on Sept. 9, 2013, 8:16 p.m.

Details

Message ID 1378757804-3159-3-git-send-email-vfalico@redhat.com
State Changes Requested
Delegated to: David Miller
Headers show

Commit Message

Veaceslav Falico Sept. 9, 2013, 8:16 p.m.
Currently we have only the RTNL flavour, however we can traverse it while
holding only RCU, so add the RCU search. Add only one function that will be
used further, other functions can be added easily afterwards, if anyone
would need them.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
---
 net/core/dev.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

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diff --git a/net/core/dev.c b/net/core/dev.c
index 8832711..749ec0b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4380,6 +4380,33 @@  struct netdev_adjacent {
 	struct rcu_head rcu;
 };
 
+static struct netdev_adjacent *__netdev_find_adj_rcu(struct net_device *dev,
+						     struct net_device *adj_dev,
+						     bool upper, bool neighbour)
+{
+	struct netdev_adjacent *adj;
+	struct list_head *adj_list;
+
+	if (neighbour)
+		adj_list = upper ? &dev->adj_list.upper :
+				   &dev->adj_list.lower;
+	else
+		adj_list = upper ? &dev->all_adj_list.upper :
+				   &dev->all_adj_list.lower;
+
+	list_for_each_entry_rcu(adj, adj_list, list) {
+		if (adj->dev == adj_dev)
+			return adj;
+	}
+	return NULL;
+}
+
+static struct netdev_adjacent *__netdev_lower_find_rcu(struct net_device *dev,
+							struct net_device *ldev)
+{
+	return __netdev_find_adj_rcu(dev, ldev, false, true);
+}
+
 static struct netdev_adjacent *__netdev_find_adj(struct net_device *dev,
 						 struct net_device *adj_dev,
 						 bool upper, bool neighbour)