From patchwork Wed Feb 10 15:57:27 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antonio Quartulli X-Patchwork-Id: 5082 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 CDAAF81D44 for ; Wed, 10 Feb 2016 17:18:34 +0100 (CET) From: Antonio Quartulli To: davem@davemloft.net Date: Wed, 10 Feb 2016 23:57:27 +0800 Message-Id: <1455119847-5862-22-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 21/21] batman-adv: Convert batadv_tt_common_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 16:18:35 -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/translation-table.c | 64 +++++++++++++++++++++++++++++--------- net/batman-adv/types.h | 2 +- 2 files changed, 51 insertions(+), 15 deletions(-) diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 96b1571213bd..11882793f0a4 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -142,7 +142,7 @@ batadv_tt_hash_find(struct batadv_hashtable *hash, const u8 *addr, if (tt->vid != vid) continue; - if (!atomic_inc_not_zero(&tt->refcount)) + if (!kref_get_unless_zero(&tt->refcount)) continue; tt_tmp = tt; @@ -203,25 +203,59 @@ batadv_tt_global_hash_find(struct batadv_priv *bat_priv, const u8 *addr, return tt_global_entry; } -static void -batadv_tt_local_entry_free_ref(struct batadv_tt_local_entry *tt_local_entry) +/** + * batadv_tt_local_entry_release - release tt_local_entry from lists and queue + * for free after rcu grace period + * @ref: kref pointer of the nc_node + */ +static void batadv_tt_local_entry_release(struct kref *ref) { - if (atomic_dec_and_test(&tt_local_entry->common.refcount)) - kfree_rcu(tt_local_entry, common.rcu); + struct batadv_tt_local_entry *tt_local_entry; + + tt_local_entry = container_of(ref, struct batadv_tt_local_entry, + common.refcount); + + kfree_rcu(tt_local_entry, common.rcu); } /** - * batadv_tt_global_entry_free_ref - decrement the refcounter for a - * tt_global_entry and possibly free it - * @tt_global_entry: the object to free + * batadv_tt_local_entry_free_ref - decrement the tt_local_entry refcounter and + * possibly release it + * @tt_local_entry: tt_local_entry to be free'd + */ +static void +batadv_tt_local_entry_free_ref(struct batadv_tt_local_entry *tt_local_entry) +{ + kref_put(&tt_local_entry->common.refcount, + batadv_tt_local_entry_release); +} + +/** + * batadv_tt_global_entry_release - release tt_global_entry from lists and queue + * for free after rcu grace period + * @ref: kref pointer of the nc_node + */ +static void batadv_tt_global_entry_release(struct kref *ref) +{ + struct batadv_tt_global_entry *tt_global_entry; + + tt_global_entry = container_of(ref, struct batadv_tt_global_entry, + common.refcount); + + batadv_tt_global_del_orig_list(tt_global_entry); + kfree_rcu(tt_global_entry, common.rcu); +} + +/** + * batadv_tt_global_entry_free_ref - decrement the tt_global_entry refcounter + * and possibly release it + * @tt_global_entry: tt_global_entry to be free'd */ static void batadv_tt_global_entry_free_ref(struct batadv_tt_global_entry *tt_global_entry) { - if (atomic_dec_and_test(&tt_global_entry->common.refcount)) { - batadv_tt_global_del_orig_list(tt_global_entry); - kfree_rcu(tt_global_entry, common.rcu); - } + kref_put(&tt_global_entry->common.refcount, + batadv_tt_global_entry_release); } /** @@ -633,7 +667,8 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const u8 *addr, tt_local->common.vid = vid; if (batadv_is_wifi_netdev(in_dev)) tt_local->common.flags |= BATADV_TT_CLIENT_WIFI; - atomic_set(&tt_local->common.refcount, 2); + kref_init(&tt_local->common.refcount); + kref_get(&tt_local->common.refcount); tt_local->last_seen = jiffies; tt_local->common.added_at = tt_local->last_seen; @@ -1415,7 +1450,8 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv, */ if (flags & BATADV_TT_CLIENT_ROAM) tt_global_entry->roam_at = jiffies; - atomic_set(&common->refcount, 2); + kref_init(&common->refcount); + kref_get(&common->refcount); common->added_at = jiffies; INIT_HLIST_HEAD(&tt_global_entry->orig_list); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index aea82a121c02..612de23178e6 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -972,7 +972,7 @@ struct batadv_tt_common_entry { struct hlist_node hash_entry; u16 flags; unsigned long added_at; - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; };