From patchwork Sat Jan 16 09:29:49 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Eckelmann X-Patchwork-Id: 4987 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=L4PjJm88; 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 6785F81B76 for ; Sat, 16 Jan 2016 10:30:10 +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 9BC511100E7; Sat, 16 Jan 2016 10:30:09 +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=1452936609; bh=VrNzysYTjvycYN8hOI7xLdYD9nsS+DKTqpmhhaM5n50=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L4PjJm886QZ6b57AlHPfB0Cyuna2wbaNyZfs7pUMKHPp6Ki1DuSgyJG4c7F6E559R nSwQnhqxr8OSmrIyEQPPVf9mtzV6rfq8vIdkdFU8OGivmWdm0n4pUt9m1kl1DLXKK1 2QmQ8gFTrp4/rMRT4b8GWhuXy4OwxpFhw5TxRsyw= From: Sven Eckelmann To: b.a.t.m.a.n@lists.open-mesh.org Date: Sat, 16 Jan 2016 10:29:49 +0100 Message-Id: <1452936598-28619-11-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 11/20] batman-adv: Convert batadv_tvlv_handler 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 09:30:11 -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/main.c | 24 ++++++++++++++++++------ net/batman-adv/types.h | 2 +- 2 files changed, 19 insertions(+), 7 deletions(-) diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index 4b6c258..568c550 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -625,15 +625,27 @@ __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr) } /** - * batadv_tvlv_handler_free_ref - decrement the tvlv handler refcounter and - * possibly free it + * batadv_tvlv_handler_release - release tvlv handler from lists and queue for + * free after rcu grace period + * @ref: kref pointer of the tvlv + */ +static void batadv_tvlv_handler_release(struct kref *ref) +{ + struct batadv_tvlv_handler *tvlv_handler; + + tvlv_handler = container_of(ref, struct batadv_tvlv_handler, refcount); + kfree_rcu(tvlv_handler, rcu); +} + +/** + * batadv_tvlv_handler_free_ref - decrement the tvlv container refcounter and + * possibly release it * @tvlv_handler: the tvlv handler to free */ static void batadv_tvlv_handler_free_ref(struct batadv_tvlv_handler *tvlv_handler) { - if (atomic_dec_and_test(&tvlv_handler->refcount)) - kfree_rcu(tvlv_handler, rcu); + kref_put(&tvlv_handler->refcount, batadv_tvlv_handler_release); } /** @@ -659,7 +671,7 @@ static struct batadv_tvlv_handler if (tvlv_handler_tmp->version != version) continue; - if (!atomic_inc_not_zero(&tvlv_handler_tmp->refcount)) + if (!kref_get_unless_zero(&tvlv_handler_tmp->refcount)) continue; tvlv_handler = tvlv_handler_tmp; @@ -1112,7 +1124,7 @@ void batadv_tvlv_handler_register(struct batadv_priv *bat_priv, tvlv_handler->type = type; tvlv_handler->version = version; tvlv_handler->flags = flags; - atomic_set(&tvlv_handler->refcount, 1); + kref_init(&tvlv_handler->refcount); INIT_HLIST_NODE(&tvlv_handler->list); spin_lock_bh(&bat_priv->tvlv.handler_list_lock); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index c55925b..f89dd97 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1293,7 +1293,7 @@ struct batadv_tvlv_handler { u8 type; u8 version; u8 flags; - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; };