From patchwork Wed Feb 10 15:57:11 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antonio Quartulli X-Patchwork-Id: 5051 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 55EC681D18 for ; Wed, 10 Feb 2016 17:00:13 +0100 (CET) From: Antonio Quartulli To: davem@davemloft.net Date: Wed, 10 Feb 2016 23:57:11 +0800 Message-Id: <1455119847-5862-6-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 05/21] batman-adv: Convert batadv_gw_node 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 16:00:13 -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/gateway_client.c | 40 +++++++++++++++++++++++++++++----------- net/batman-adv/types.h | 2 +- 2 files changed, 30 insertions(+), 12 deletions(-) diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index 5950974de7b1..1f3847c61db8 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -59,12 +60,29 @@ */ #define BATADV_DHCP_CHADDR_OFFSET 28 +/** + * batadv_gw_node_release - release gw_node from lists and queue for free after + * rcu grace period + * @ref: kref pointer of the gw_node + */ +static void batadv_gw_node_release(struct kref *ref) +{ + struct batadv_gw_node *gw_node; + + gw_node = container_of(ref, struct batadv_gw_node, refcount); + + batadv_orig_node_free_ref(gw_node->orig_node); + kfree_rcu(gw_node, rcu); +} + +/** + * batadv_gw_node_free_ref - decrement the gw_node refcounter and possibly + * release it + * @gw_node: gateway node to free + */ static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node) { - if (atomic_dec_and_test(&gw_node->refcount)) { - batadv_orig_node_free_ref(gw_node->orig_node); - kfree_rcu(gw_node, rcu); - } + kref_put(&gw_node->refcount, batadv_gw_node_release); } static struct batadv_gw_node * @@ -77,7 +95,7 @@ batadv_gw_get_selected_gw_node(struct batadv_priv *bat_priv) if (!gw_node) goto out; - if (!atomic_inc_not_zero(&gw_node->refcount)) + if (!kref_get_unless_zero(&gw_node->refcount)) gw_node = NULL; out: @@ -118,7 +136,7 @@ static void batadv_gw_select(struct batadv_priv *bat_priv, spin_lock_bh(&bat_priv->gw.list_lock); - if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount)) + if (new_gw_node && !kref_get_unless_zero(&new_gw_node->refcount)) new_gw_node = NULL; curr_gw_node = rcu_dereference_protected(bat_priv->gw.curr_gw, 1); @@ -170,7 +188,7 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv) if (!router_ifinfo) goto next; - if (!atomic_inc_not_zero(&gw_node->refcount)) + if (!kref_get_unless_zero(&gw_node->refcount)) goto next; tq_avg = router_ifinfo->bat_iv.tq_avg; @@ -188,7 +206,7 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv) if (curr_gw) batadv_gw_node_free_ref(curr_gw); curr_gw = gw_node; - atomic_inc(&curr_gw->refcount); + kref_get(&curr_gw->refcount); } break; @@ -203,7 +221,7 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv) if (curr_gw) batadv_gw_node_free_ref(curr_gw); curr_gw = gw_node; - atomic_inc(&curr_gw->refcount); + kref_get(&curr_gw->refcount); } break; } @@ -436,7 +454,7 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv, gw_node->orig_node = orig_node; gw_node->bandwidth_down = ntohl(gateway->bandwidth_down); gw_node->bandwidth_up = ntohl(gateway->bandwidth_up); - atomic_set(&gw_node->refcount, 1); + kref_init(&gw_node->refcount); spin_lock_bh(&bat_priv->gw.list_lock); hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list); @@ -469,7 +487,7 @@ batadv_gw_node_get(struct batadv_priv *bat_priv, if (gw_node_tmp->orig_node != orig_node) continue; - if (!atomic_inc_not_zero(&gw_node_tmp->refcount)) + if (!kref_get_unless_zero(&gw_node_tmp->refcount)) continue; gw_node = gw_node_tmp; diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index ace7900347d4..06c38881e382 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -342,7 +342,7 @@ struct batadv_gw_node { struct batadv_orig_node *orig_node; u32 bandwidth_down; u32 bandwidth_up; - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; };