netdev - [PATCH 15/20] batman-adv: Place kref_get for nc

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Message-Id: <20160822135620.15337-16-sw@simonwunderlich.de>
Date:   Mon, 22 Aug 2016 15:56:15 +0200
From:   Simon Wunderlich <sw@...onwunderlich.de>
To:     davem@...emloft.net
Cc:     netdev@...r.kernel.org, b.a.t.m.a.n@...ts.open-mesh.org,
        Sven Eckelmann <sven@...fation.org>,
        Marek Lindner <mareklindner@...mailbox.ch>,
        Simon Wunderlich <sw@...onwunderlich.de>
Subject: [PATCH 15/20] batman-adv: Place kref_get for nc_node near use

From: Sven Eckelmann <sven@...fation.org>

It is hard to understand why the refcnt is increased when it isn't done
near the actual place the new reference is used. So using kref_get right
before the place which requires the reference and in the same function
helps to avoid accidental problems caused by incorrect reference counting.

Signed-off-by: Sven Eckelmann <sven@...fation.org>
Signed-off-by: Marek Lindner <mareklindner@...mailbox.ch>
Signed-off-by: Simon Wunderlich <sw@...onwunderlich.de>
---
 net/batman-adv/network-coding.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index 3814cfb..4f4cfe5 100644
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -859,7 +859,6 @@ batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
 	/* Initialize nc_node */
 	INIT_LIST_HEAD(&nc_node->list);
 	kref_init(&nc_node->refcount);
-	kref_get(&nc_node->refcount);
 	ether_addr_copy(nc_node->addr, orig_node->orig);
 	kref_get(&orig_neigh_node->refcount);
 	nc_node->orig_node = orig_neigh_node;
@@ -878,6 +877,7 @@ batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
 
 	/* Add nc_node to orig_node */
 	spin_lock_bh(lock);
+	kref_get(&nc_node->refcount);
 	list_add_tail_rcu(&nc_node->list, list);
 	spin_unlock_bh(lock);
 
-- 
2.9.3