From patchwork Wed Feb 10 15:57:17 2016
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
X-Patchwork-Submitter: Antonio Quartulli
X-Patchwork-Id: 5026
Return-Path:
Received-SPF: Permerror (SPF Permanent Error: Two or more type TXT spf
records found.) identity=mailfrom; client-ip=5.148.176.60;
helo=s2.neomailbox.net;
envelope-from=a@unstable.cc; receiver=b.a.t.m.a.n@lists.open-mesh.org
Authentication-Results: open-mesh.org; dmarc=none header.from=unstable.cc
Received: from s2.neomailbox.net (s2.neomailbox.net [5.148.176.60])
by open-mesh.org (Postfix) with ESMTPS id 65E0381D39
for ;
Wed, 10 Feb 2016 17:18:20 +0100 (CET)
From: Antonio Quartulli
To: davem@davemloft.net
Date: Wed, 10 Feb 2016 23:57:17 +0800
Message-Id: <1455119847-5862-12-git-send-email-a@unstable.cc>
In-Reply-To: <1455119847-5862-1-git-send-email-a@unstable.cc>
References: <1455119847-5862-1-git-send-email-a@unstable.cc>
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 11/21] batman-adv: Convert batadv_dat_entry
to kref
X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: The list for a Better Approach To Mobile Ad-hoc Networking
List-Unsubscribe: ,
List-Archive:
List-Post:
List-Help:
List-Subscribe: ,
X-List-Received-Date: Wed, 10 Feb 2016 16:18:20 -0000
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/distributed-arp-table.c | 27 +++++++++++++++++++++------
net/batman-adv/types.h | 2 +-
2 files changed, 22 insertions(+), 7 deletions(-)
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index 017fffe9a5b8..921e25255cab 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -30,6 +30,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -62,14 +63,27 @@ static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
}
/**
+ * batadv_dat_entry_release - release dat_entry from lists and queue for free
+ * after rcu grace period
+ * @ref: kref pointer of the dat_entry
+ */
+static void batadv_dat_entry_release(struct kref *ref)
+{
+ struct batadv_dat_entry *dat_entry;
+
+ dat_entry = container_of(ref, struct batadv_dat_entry, refcount);
+
+ kfree_rcu(dat_entry, rcu);
+}
+
+/**
* batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly
- * free it
- * @dat_entry: the entry to free
+ * release it
+ * @dat_entry: dat_entry to be free'd
*/
static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry)
{
- if (atomic_dec_and_test(&dat_entry->refcount))
- kfree_rcu(dat_entry, rcu);
+ kref_put(&dat_entry->refcount, batadv_dat_entry_release);
}
/**
@@ -281,7 +295,7 @@ batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
if (dat_entry->ip != ip)
continue;
- if (!atomic_inc_not_zero(&dat_entry->refcount))
+ if (!kref_get_unless_zero(&dat_entry->refcount))
continue;
dat_entry_tmp = dat_entry;
@@ -326,7 +340,8 @@ static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
dat_entry->vid = vid;
ether_addr_copy(dat_entry->mac_addr, mac_addr);
dat_entry->last_update = jiffies;
- atomic_set(&dat_entry->refcount, 2);
+ kref_init(&dat_entry->refcount);
+ kref_get(&dat_entry->refcount);
hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
batadv_hash_dat, dat_entry,
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index b3d9b5b566a2..9df8f39e4785 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -1230,7 +1230,7 @@ struct batadv_dat_entry {
unsigned short vid;
unsigned long last_update;
struct hlist_node hash_entry;
- atomic_t refcount;
+ struct kref refcount;
struct rcu_head rcu;
};