ovpn: disable BHs when updating device stats

ovpn updates dev->dstats from both process and softirq contexts. In
particular, TCP paths may run from socket callbacks, workqueues or
strparser work, while UDP receive and ovpn's ndo_start_xmit path may
update the same per-device dstats from BH context.

Add ovpn device drop-stat helpers that disable BHs around
dev_dstats_rx_dropped() and dev_dstats_tx_dropped(), and use them for
drop accounting.

The successful RX dev_dstats_rx_add() update is already covered by the
BH-disabled section around gro_cells_receive(). For the successful TCP
TX dev_dstats_tx_add() update, replace the existing preempt-disabled
section with a BH-disabled one.

Fixes: 11851cbd60ea ("ovpn: implement TCP transport")
Signed-off-by: Ralf Lici <ralf@mandelbit.com>
Signed-off-by: Antonio Quartulli <antonio@openvpn.net>

diff --git a/drivers/net/ovpn/io.c b/drivers/net/ovpn/io.c
index 22c555dd962ec73dc0b6270812edcb0399375580..a6b777a9c2d9a248bd00e9a1b89ea19cb2b367b3 100644 (file)
--- a/drivers/net/ovpn/io.c
+++ b/drivers/net/ovpn/io.c
@@ -201,7 +201,7 @@ void ovpn_decrypt_post(void *data, int ret)
        skb = NULL;
 drop:
        if (unlikely(skb))
-               dev_dstats_rx_dropped(peer->ovpn->dev);
+               ovpn_dev_dstats_rx_dropped(peer->ovpn->dev);
        kfree_skb(skb);
 drop_nocount:
        if (likely(peer))
@@ -225,7 +225,7 @@ void ovpn_recv(struct ovpn_peer *peer, struct sk_buff *skb)
                net_info_ratelimited("%s: no available key for peer %u, key-id: %u\n",
                                     netdev_name(peer->ovpn->dev), peer->id,
                                     key_id);
-               dev_dstats_rx_dropped(peer->ovpn->dev);
+               ovpn_dev_dstats_rx_dropped(peer->ovpn->dev);
                kfree_skb(skb);
                ovpn_peer_put(peer);
                return;
@@ -301,7 +301,7 @@ err_unlock:
        rcu_read_unlock();
 err:
        if (unlikely(skb))
-               dev_dstats_tx_dropped(peer->ovpn->dev);
+               ovpn_dev_dstats_tx_dropped(peer->ovpn->dev);
        if (likely(peer))
                ovpn_peer_put(peer);
        if (likely(ks))
@@ -343,7 +343,7 @@ static void ovpn_send(struct ovpn_priv *ovpn, struct sk_buff *skb,
         */
        skb_list_walk_safe(skb, curr, next) {
                if (unlikely(!ovpn_encrypt_one(peer, curr))) {
-                       dev_dstats_tx_dropped(ovpn->dev);
+                       ovpn_dev_dstats_tx_dropped(ovpn->dev);
                        kfree_skb(curr);
                }
        }
@@ -414,7 +414,7 @@ netdev_tx_t ovpn_net_xmit(struct sk_buff *skb, struct net_device *dev)
                if (unlikely(!curr)) {
                        net_err_ratelimited("%s: skb_share_check failed for payload packet\n",
                                            netdev_name(dev));
-                       dev_dstats_tx_dropped(ovpn->dev);
+                       ovpn_dev_dstats_tx_dropped(ovpn->dev);
                        continue;
                }
 
@@ -440,7 +440,7 @@ netdev_tx_t ovpn_net_xmit(struct sk_buff *skb, struct net_device *dev)
 drop:
        ovpn_peer_put(peer);
 drop_no_peer:
-       dev_dstats_tx_dropped(ovpn->dev);
+       ovpn_dev_dstats_tx_dropped(ovpn->dev);
        skb_tx_error(skb);
        kfree_skb_list(skb);
        return NETDEV_TX_OK;

diff --git a/drivers/net/ovpn/stats.h b/drivers/net/ovpn/stats.h
index 53433d8b6c33160845de2ae1ca38e85cf31950b7..3a45b97c00568e569a83a576aebecb5e7fa1e7ac 100644 (file)
--- a/drivers/net/ovpn/stats.h
+++ b/drivers/net/ovpn/stats.h
@@ -11,6 +11,8 @@
 #ifndef _NET_OVPN_OVPNSTATS_H_
 #define _NET_OVPN_OVPNSTATS_H_
 
+#include <linux/netdevice.h>
+
 /* one stat */
 struct ovpn_peer_stat {
        atomic64_t bytes;
@@ -44,4 +46,18 @@ static inline void ovpn_peer_stats_increment_tx(struct ovpn_peer_stats *stats,
        ovpn_peer_stats_increment(&stats->tx, n);
 }
 
+static inline void ovpn_dev_dstats_tx_dropped(struct net_device *dev)
+{
+       local_bh_disable();
+       dev_dstats_tx_dropped(dev);
+       local_bh_enable();
+}
+
+static inline void ovpn_dev_dstats_rx_dropped(struct net_device *dev)
+{
+       local_bh_disable();
+       dev_dstats_rx_dropped(dev);
+       local_bh_enable();
+}
+
 #endif /* _NET_OVPN_OVPNSTATS_H_ */

diff --git a/drivers/net/ovpn/tcp.c b/drivers/net/ovpn/tcp.c
index 82809b016f0a84c6222cee0cdd06f78f3bddb289..433bd07a4f1be9ab39ac8d82ca5ae58e71464857 100644 (file)
--- a/drivers/net/ovpn/tcp.c
+++ b/drivers/net/ovpn/tcp.c
@@ -152,7 +152,7 @@ err:
        if (WARN_ON(!ovpn_peer_hold(peer)))
                goto err_nopeer;
        schedule_work(&peer->tcp.defer_del_work);
-       dev_dstats_rx_dropped(peer->ovpn->dev);
+       ovpn_dev_dstats_rx_dropped(peer->ovpn->dev);
 err_nopeer:
        kfree_skb(skb);
 }
@@ -298,9 +298,9 @@ static void ovpn_tcp_send_sock(struct ovpn_peer *peer, struct sock *sk)
        } while (peer->tcp.out_msg.len > 0);
 
        if (!peer->tcp.out_msg.len) {
-               preempt_disable();
+               local_bh_disable();
                dev_dstats_tx_add(peer->ovpn->dev, skb->len);
-               preempt_enable();
+               local_bh_enable();
        }
 
        kfree_skb(peer->tcp.out_msg.skb);
@@ -331,7 +331,7 @@ static void ovpn_tcp_send_sock_skb(struct ovpn_peer *peer, struct sock *sk,
                ovpn_tcp_send_sock(peer, sk);
 
        if (peer->tcp.out_msg.skb) {
-               dev_dstats_tx_dropped(peer->ovpn->dev);
+               ovpn_dev_dstats_tx_dropped(peer->ovpn->dev);
                kfree_skb(skb);
                return;
        }
@@ -353,7 +353,7 @@ void ovpn_tcp_send_skb(struct ovpn_peer *peer, struct sock *sk,
        if (sock_owned_by_user(sk)) {
                if (skb_queue_len(&peer->tcp.out_queue) >=
                    READ_ONCE(net_hotdata.max_backlog)) {
-                       dev_dstats_tx_dropped(peer->ovpn->dev);
+                       ovpn_dev_dstats_tx_dropped(peer->ovpn->dev);
                        kfree_skb(skb);
                        goto unlock;
                }

diff --git a/drivers/net/ovpn/udp.c b/drivers/net/ovpn/udp.c
index 059e896b4a2fdabe2ae5dc33adb059d841cc7b21..8811aa9eedeba2f6dd46a0ee9fa8b9390ff1259b 100644 (file)
--- a/drivers/net/ovpn/udp.c
+++ b/drivers/net/ovpn/udp.c
@@ -125,7 +125,7 @@ static int ovpn_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
        return 0;
 
 drop:
-       dev_dstats_rx_dropped(ovpn->dev);
+       ovpn_dev_dstats_rx_dropped(ovpn->dev);
 drop_noovpn:
        kfree_skb(skb);
        return 0;