From patchwork Sat Jan 16 09:29:41 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Eckelmann X-Patchwork-Id: 4877 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=79.140.41.39; helo=v3-1039.vlinux.de; envelope-from=sven@narfation.org; receiver=b.a.t.m.a.n@lists.open-mesh.org Authentication-Results: open-mesh.org; dmarc=pass header.from=narfation.org Authentication-Results: open-mesh.org; dkim=pass reason="1024-bit key; unprotected key" header.d=narfation.org header.i=@narfation.org header.b=qh7GBM4R; dkim-adsp=pass; dkim-atps=neutral Received: from v3-1039.vlinux.de (narfation.org [79.140.41.39]) by open-mesh.org (Postfix) with ESMTPS id 2F33481B6E for ; Sat, 16 Jan 2016 10:30:04 +0100 (CET) Received: from sven-desktop.home.narfation.org (p200300C593C167FD0000000000002E16.dip0.t-ipconnect.de [IPv6:2003:c5:93c1:67fd::2e16]) by v3-1039.vlinux.de (Postfix) with ESMTPSA id AACEA1100E7; Sat, 16 Jan 2016 10:30:03 +0100 (CET) Authentication-Results: v3-1039.vlinux.de; dmarc=none header.from=narfation.org DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=narfation.org; s=20121; t=1452936603; bh=5FB9qkIimqilgS/s1QdnzcIjMgwHK00K4NZAuxk2kcM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qh7GBM4RcTz0Ypc8q8/zisu6fOtsPq90XzBWnY4MFeio0yZ93nKSBdplOruHU89x0 jnV9DI0czOtLrWB53LOu0jDs87RGIwGLm/QA0emcWT4G0mxeOWhlFp4PjriXQ2xRls 4UiHUh6gqaqau5itJSgnc2KGKu6KAxq5pUqqo+v8= From: Sven Eckelmann To: b.a.t.m.a.n@lists.open-mesh.org Date: Sat, 16 Jan 2016 10:29:41 +0100 Message-Id: <1452936598-28619-3-git-send-email-sven@narfation.org> X-Mailer: git-send-email 2.7.0.rc3 In-Reply-To: <1452936598-28619-1-git-send-email-sven@narfation.org> References: <1452936598-28619-1-git-send-email-sven@narfation.org> Subject: [B.A.T.M.A.N.] [PATCH v6 03/20] 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: Sat, 16 Jan 2016 09:30:04 -0000 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 --- v6: - removed patches which are now applied in the branch next - rebased remaining patches on the patch "batman-adv: Avoid recursive call_rcu for batadv_nc_node" which was modified by Marek while he applied the patches (this unfortunately made some of the remaining patches "hard" to apply) v5: - add hack which allows to compile against stable kernel like 3.2.44 which also added the kref_get_unless_zero function v4: - fix function names in commit messages - fix double whitespace in batadv_tt_orig_list_entry_release kerneldoc - add extra patch for batadv_claim_free_ref kerneldoc fix - change the phrase "free it" in all *_free_ref/*_put functions to "release it" v3: - update copyright year v2: - split patchset into fixes and kref migration to make it easier when the decision is made where each patch will be applied 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 5950974..1f3847c 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 ace7900..06c3888 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; };