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From: Antonio Quartulli
To: davem@davemloft.net
Date: Wed, 10 Feb 2016 23:57:16 +0800
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Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org,
Antonio Quartulli ,
Marek Lindner
Subject: [B.A.T.M.A.N.] [PATCH 10/21] batman-adv: Convert batadv_nc_path to
kref
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From: Sven Eckelmann
batman-adv uses a self-written reference implementation which is just based
on atomic_t. This is less obvious when reading the code than kref and
therefore increases the change that the reference counting will be missed.
Signed-off-by: Sven Eckelmann
Signed-off-by: Marek Lindner
Signed-off-by: Antonio Quartulli
---
net/batman-adv/network-coding.c | 28 +++++++++++++++++++++-------
net/batman-adv/types.h | 2 +-
2 files changed, 22 insertions(+), 8 deletions(-)
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index 7a1216eeb4cf..371fc6bbf9d6 100644
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -233,14 +233,27 @@ static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node)
}
/**
- * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly
- * frees it
- * @nc_path: the nc node to free
+ * batadv_nc_path_release - release nc_path from lists and queue for free after
+ * rcu grace period
+ * @ref: kref pointer of the nc_path
+ */
+static void batadv_nc_path_release(struct kref *ref)
+{
+ struct batadv_nc_path *nc_path;
+
+ nc_path = container_of(ref, struct batadv_nc_path, refcount);
+
+ kfree_rcu(nc_path, rcu);
+}
+
+/**
+ * batadv_nc_path_free_ref - decrement the nc_path refcounter and possibly
+ * release it
+ * @nc_path: nc_path to be free'd
*/
static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path)
{
- if (atomic_dec_and_test(&nc_path->refcount))
- kfree_rcu(nc_path, rcu);
+ kref_put(&nc_path->refcount, batadv_nc_path_release);
}
/**
@@ -545,7 +558,7 @@ batadv_nc_hash_find(struct batadv_hashtable *hash,
if (!batadv_nc_hash_compare(&nc_path->hash_entry, data))
continue;
- if (!atomic_inc_not_zero(&nc_path->refcount))
+ if (!kref_get_unless_zero(&nc_path->refcount))
continue;
nc_path_tmp = nc_path;
@@ -972,7 +985,8 @@ static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,
/* Initialize nc_path */
INIT_LIST_HEAD(&nc_path->packet_list);
spin_lock_init(&nc_path->packet_list_lock);
- atomic_set(&nc_path->refcount, 2);
+ kref_init(&nc_path->refcount);
+ kref_get(&nc_path->refcount);
nc_path->last_valid = jiffies;
ether_addr_copy(nc_path->next_hop, dst);
ether_addr_copy(nc_path->prev_hop, src);
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 05421afb1d74..b3d9b5b566a2 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -1087,7 +1087,7 @@ struct batadv_nc_node {
struct batadv_nc_path {
struct hlist_node hash_entry;
struct rcu_head rcu;
- atomic_t refcount;
+ struct kref refcount;
struct list_head packet_list;
spinlock_t packet_list_lock; /* Protects packet_list */
u8 next_hop[ETH_ALEN];