From patchwork Wed Feb 10 15:57:13 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antonio Quartulli X-Patchwork-Id: 5020 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 95CE581C09 for ; Wed, 10 Feb 2016 17:00:17 +0100 (CET) From: Antonio Quartulli To: davem@davemloft.net Date: Wed, 10 Feb 2016 23:57:13 +0800 Message-Id: <1455119847-5862-8-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 07/21] batman-adv: Convert batadv_bla_backbone_gw 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 16:00:17 -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/bridge_loop_avoidance.c | 29 +++++++++++++++++++++++------ net/batman-adv/types.h | 2 +- 2 files changed, 24 insertions(+), 7 deletions(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 779160934844..41116e4c2e34 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -143,14 +144,29 @@ static int batadv_compare_claim(const struct hlist_node *node, } /** - * batadv_compare_backbone_gw - free backbone gw + * batadv_backbone_gw_release - release backbone gw from lists and queue for + * free after rcu grace period + * @ref: kref pointer of the backbone gw + */ +static void batadv_backbone_gw_release(struct kref *ref) +{ + struct batadv_bla_backbone_gw *backbone_gw; + + backbone_gw = container_of(ref, struct batadv_bla_backbone_gw, + refcount); + + kfree_rcu(backbone_gw, rcu); +} + +/** + * batadv_backbone_gw_free_ref - decrement the backbone gw refcounter and + * possibly release it * @backbone_gw: backbone gateway to be free'd */ static void batadv_backbone_gw_free_ref(struct batadv_bla_backbone_gw *backbone_gw) { - if (atomic_dec_and_test(&backbone_gw->refcount)) - kfree_rcu(backbone_gw, rcu); + kref_put(&backbone_gw->refcount, batadv_backbone_gw_release); } /** @@ -247,7 +263,7 @@ batadv_backbone_hash_find(struct batadv_priv *bat_priv, u8 *addr, &search_entry)) continue; - if (!atomic_inc_not_zero(&backbone_gw->refcount)) + if (!kref_get_unless_zero(&backbone_gw->refcount)) continue; backbone_gw_tmp = backbone_gw; @@ -448,7 +464,8 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, u8 *orig, ether_addr_copy(entry->orig, orig); /* one for the hash, one for returning */ - atomic_set(&entry->refcount, 2); + kref_init(&entry->refcount); + kref_get(&entry->refcount); hash_added = batadv_hash_add(bat_priv->bla.backbone_hash, batadv_compare_backbone_gw, @@ -664,7 +681,7 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv, batadv_backbone_gw_free_ref(claim->backbone_gw); } /* set (new) backbone gw */ - atomic_inc(&backbone_gw->refcount); + kref_get(&backbone_gw->refcount); claim->backbone_gw = backbone_gw; spin_lock_bh(&backbone_gw->crc_lock); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 868f6b592b7c..595f52400b1f 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -930,7 +930,7 @@ struct batadv_bla_backbone_gw { atomic_t request_sent; u16 crc; spinlock_t crc_lock; /* protects crc */ - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; };