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; };