batman-adv: replace non-atomic mesh state with (READ|WRITE)_ONCE

The mesh state is only accessed as plain loads/stores and does not require
full atomic_t semantics. Convert to an enum and replace its users with
READ_ONCE()/WRITE_ONCE() to avoid load/store tearing.

Signed-off-by: Sven Eckelmann <sven@narfation.org>

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index df8e64588e1e73f848d194262af7717582122b3c..c436b77674a56ab52508a2076a28948eb629b59a 100644 (file)
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -1777,7 +1777,7 @@ static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work)
                                   delayed_work);
        bat_priv = netdev_priv(forw_packet->if_incoming->mesh_iface);
 
-       if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
+       if (READ_ONCE(bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
                dropped = true;
                goto out;
        }

diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c
index 0190fafcbed2d235491d36f4031c4ebe1bdfda63..d53485d17220e68627909a1d9f6f8e69bdf67e4e 100644 (file)
--- a/net/batman-adv/bat_v_elp.c
+++ b/net/batman-adv/bat_v_elp.c
@@ -307,7 +307,7 @@ static void batadv_v_elp_periodic_work(struct work_struct *work)
        hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
        bat_priv = netdev_priv(hard_iface->mesh_iface);
 
-       if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
+       if (READ_ONCE(bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
                goto out;
 
        /* we are in the process of shutting this interface down */

diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
index f4cd8cad97e0cd362627266e97f37d204f750146..b337bd8e58e7d9db5cd78a726a6154d29e1f53d5 100644 (file)
--- a/net/batman-adv/bat_v_ogm.c
+++ b/net/batman-adv/bat_v_ogm.c
@@ -279,7 +279,7 @@ static void batadv_v_ogm_send_meshif(struct batadv_priv *bat_priv)
 
        lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
 
-       if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
+       if (READ_ONCE(bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
                goto out;
 
        ogm_buff = &bat_priv->bat_v.ogm_buff;

diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index a5398c5df2632da677370b2336f7a81631638cbb..60d4f60066c80f5fd443ee62937ece9f881b69c1 100644 (file)
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -200,31 +200,31 @@ int batadv_mesh_init(struct net_device *mesh_iface)
 
        ret = batadv_originator_init(bat_priv);
        if (ret < 0) {
-               atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
+               WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
                goto err_orig;
        }
 
        ret = batadv_tt_init(bat_priv);
        if (ret < 0) {
-               atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
+               WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
                goto err_tt;
        }
 
        ret = batadv_v_mesh_init(bat_priv);
        if (ret < 0) {
-               atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
+               WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
                goto err_v;
        }
 
        ret = batadv_bla_init(bat_priv);
        if (ret < 0) {
-               atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
+               WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
                goto err_bla;
        }
 
        ret = batadv_dat_init(bat_priv);
        if (ret < 0) {
-               atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
+               WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
                goto err_dat;
        }
 
@@ -232,7 +232,7 @@ int batadv_mesh_init(struct net_device *mesh_iface)
        batadv_mcast_init(bat_priv);
 
        atomic_set(&bat_priv->gw.reselect, 0);
-       atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
+       WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_ACTIVE);
 
        return 0;
 
@@ -246,7 +246,7 @@ err_tt:
        batadv_originator_free(bat_priv);
 err_orig:
        batadv_purge_outstanding_packets(bat_priv, NULL);
-       atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
+       WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 
        return ret;
 }
@@ -259,7 +259,7 @@ void batadv_mesh_free(struct net_device *mesh_iface)
 {
        struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
 
-       atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
+       WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
 
        batadv_purge_outstanding_packets(bat_priv, NULL);
        batadv_tp_stop_all(bat_priv);
@@ -290,7 +290,7 @@ void batadv_mesh_free(struct net_device *mesh_iface)
        free_percpu(bat_priv->bat_counters);
        bat_priv->bat_counters = NULL;
 
-       atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
+       WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 }
 
 /**
@@ -454,7 +454,7 @@ int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 
        bat_priv = netdev_priv(hard_iface->mesh_iface);
 
-       if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
+       if (READ_ONCE(bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
                goto err_free;
 
        /* discard frames on not active interfaces */

diff --git a/net/batman-adv/mesh-interface.c b/net/batman-adv/mesh-interface.c
index 58cbb4f8a5abdf05aca8e2599bbd46e88fceb65b..7497f307c10db807753381f40a8d0f366df22d22 100644 (file)
--- a/net/batman-adv/mesh-interface.c
+++ b/net/batman-adv/mesh-interface.c
@@ -125,7 +125,7 @@ static int batadv_interface_set_mac_addr(struct net_device *dev, void *p)
        eth_hw_addr_set(dev, addr->sa_data);
 
        /* only modify transtable if it has been initialized before */
-       if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
+       if (READ_ONCE(bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
                return 0;
 
        rcu_read_lock();
@@ -192,7 +192,7 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb,
        int network_offset = ETH_HLEN;
        __be16 proto;
 
-       if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
+       if (READ_ONCE(bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
                goto dropped;
 
        /* reset control block to avoid left overs from previous users */
@@ -783,7 +783,7 @@ static int batadv_meshif_init_late(struct net_device *dev)
        atomic_set(&bat_priv->bcast_queue_left, BATADV_BCAST_QUEUE_LEN);
        atomic_set(&bat_priv->batman_queue_left, BATADV_BATMAN_QUEUE_LEN);
 
-       atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
+       WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_INACTIVE);
        atomic_set(&bat_priv->bcast_seqno, 1);
        atomic_set(&bat_priv->tt.vn, 0);
        atomic_set(&bat_priv->tt.ogm_append_cnt, 0);

diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index 62ae98eef81e25a6eee9a4015dc7f6b00d339bda..c7e86c83242a27284b456b7eb737b447651ad38a 100644 (file)
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -1047,7 +1047,7 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
                                   delayed_work);
        bat_priv = netdev_priv(forw_packet->if_incoming->mesh_iface);
 
-       if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
+       if (READ_ONCE(bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
                dropped = true;
                goto out;
        }

diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c
index 0fc4ca78e84ebee217e3b4371f7b53288c3743b2..aefe757277b203031f3325ff112476e148cbfa09 100644 (file)
--- a/net/batman-adv/tp_meter.c
+++ b/net/batman-adv/tp_meter.c
@@ -999,7 +999,7 @@ void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst,
 
        /* look for an already existing test towards this node */
        spin_lock_bh(&bat_priv->tp_list_lock);
-       if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) {
+       if (READ_ONCE(bat_priv->mesh_state) != BATADV_MESH_ACTIVE) {
                spin_unlock_bh(&bat_priv->tp_list_lock);
                batadv_tp_batctl_error_notify(BATADV_TP_REASON_DST_UNREACHABLE,
                                              dst, bat_priv, session_cookie);
@@ -1387,7 +1387,7 @@ batadv_tp_init_recv(struct batadv_priv *bat_priv,
        struct batadv_tp_vars *tp_vars = NULL;
 
        spin_lock_bh(&bat_priv->tp_list_lock);
-       if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
+       if (READ_ONCE(bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
                goto out_unlock;
 
        tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig,
@@ -1518,7 +1518,7 @@ void batadv_tp_meter_recv(struct batadv_priv *bat_priv, struct sk_buff *skb)
 {
        struct batadv_icmp_tp_packet *icmp;
 
-       if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
+       if (READ_ONCE(bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
                goto out;
 
        icmp = (struct batadv_icmp_tp_packet *)skb->data;

diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index cf01a670d8250a5306cbe81f19b091898252814c..58375c0a643b86534f0bcec4d2dbb1bad93dc22c 100644 (file)
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -1504,7 +1504,7 @@ struct batadv_priv {
         * @mesh_state: current status of the mesh
         *  (inactive/active/deactivating)
         */
-       atomic_t mesh_state;
+       enum batadv_mesh_state mesh_state;
 
        /** @mesh_iface: net device which holds this struct as private data */
        struct net_device *mesh_iface;