From: Ying Xue <ying.xue@windriver.com>
Date: Wed, 15 Jan 2014 02:23:41 +0000 (+0800)
Subject: vxlan: use __dev_get_by_index instead of dev_get_by_index to find interface
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=737639493032afec87fc9e8809f80878f74bd465;p=linux-beck.git

vxlan: use __dev_get_by_index instead of dev_get_by_index to find interface

The following call chains indicate that vxlan_fdb_parse() is
under rtnl_lock protection. So if we use __dev_get_by_index()
instead of dev_get_by_index() to find interface handler in it,
this would help us avoid to change interface reference counter.

rtnetlink_rcv()
  rtnl_lock()
  netlink_rcv_skb()
    rtnl_fdb_add()
      vxlan_fdb_add()
        vxlan_fdb_parse()
  rtnl_unlock()

rtnetlink_rcv()
  rtnl_lock()
  netlink_rcv_skb()
    rtnl_fdb_del()
      vxlan_fdb_del()
        vxlan_fdb_parse()
  rtnl_unlock()

Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 481f85d604a4..8c40802e7dd9 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -741,10 +741,9 @@ static int vxlan_fdb_parse(struct nlattr *tb[], struct vxlan_dev *vxlan,
 		if (nla_len(tb[NDA_IFINDEX]) != sizeof(u32))
 			return -EINVAL;
 		*ifindex = nla_get_u32(tb[NDA_IFINDEX]);
-		tdev = dev_get_by_index(net, *ifindex);
+		tdev = __dev_get_by_index(net, *ifindex);
 		if (!tdev)
 			return -EADDRNOTAVAIL;
-		dev_put(tdev);
 	} else {
 		*ifindex = 0;
 	}