net: bonding: factor out rlock(bond->lock) in xmit path

Pull read_lock(&bond->lock) and BOND_IS_OK() to bond_start_xmit() from
mode-dependent xmit functions.

netif_running() is always true in hard_start_xmit.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 35 insertions, 60 deletions

diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index d4160f87e910..c7537abca4f2 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -2403,14 +2403,6 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
         struct ad_info ad_info;
         int res = 1;
 
-        /* make sure that the slaves list will
-         * not change during tx
-         */
-        read_lock(&bond->lock);
-
-        if (!BOND_IS_OK(bond))
-                goto out;
-
         if (bond_3ad_get_active_agg_info(bond, &ad_info)) {
                 pr_debug("%s: Error: bond_3ad_get_active_agg_info failed\n",
                          dev->name);
@@ -2464,7 +2456,7 @@ out:
                 /* no suitable interface, frame not sent */
                 dev_kfree_skb(skb);
         }
-        read_unlock(&bond->lock);
+
         return NETDEV_TX_OK;
 }
 
diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 3b7b0409406f..8f2d2e7c70e5 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -1225,16 +1225,10 @@ int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
         skb_reset_mac_header(skb);
         eth_data = eth_hdr(skb);
 
-        /* make sure that the curr_active_slave and the slaves list do
-         * not change during tx
+        /* make sure that the curr_active_slave do not change during tx
          */
-        read_lock(&bond->lock);
         read_lock(&bond->curr_slave_lock);
 
-        if (!BOND_IS_OK(bond)) {
-                goto out;
-        }
-
         switch (ntohs(skb->protocol)) {
         case ETH_P_IP: {
                 const struct iphdr *iph = ip_hdr(skb);
@@ -1334,13 +1328,12 @@ int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
                 }
         }
 
-out:
         if (res) {
                 /* no suitable interface, frame not sent */
                 dev_kfree_skb(skb);
         }
         read_unlock(&bond->curr_slave_lock);
-        read_unlock(&bond->lock);
+
         return NETDEV_TX_OK;
 }
 
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 9a5feaf4bab9..6312db1f7838 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -4004,10 +4004,6 @@ static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *bond_dev
         int i, slave_no, res = 1;
         struct iphdr *iph = ip_hdr(skb);
 
-        read_lock(&bond->lock);
-
-        if (!BOND_IS_OK(bond))
-                goto out;
         /*
          * Start with the curr_active_slave that joined the bond as the
          * default for sending IGMP traffic.  For failover purposes one
@@ -4054,7 +4050,7 @@ out:
                 /* no suitable interface, frame not sent */
                 dev_kfree_skb(skb);
         }
-        read_unlock(&bond->lock);
+
         return NETDEV_TX_OK;
 }
 
@@ -4068,24 +4064,18 @@ static int bond_xmit_activebackup(struct sk_buff *skb, struct net_device *bond_d
         struct bonding *bond = netdev_priv(bond_dev);
         int res = 1;
 
-        read_lock(&bond->lock);
         read_lock(&bond->curr_slave_lock);
 
-        if (!BOND_IS_OK(bond))
-                goto out;
+        if (bond->curr_active_slave)
+                res = bond_dev_queue_xmit(bond, skb,
+                        bond->curr_active_slave->dev);
 
-        if (!bond->curr_active_slave)
-                goto out;
-
-        res = bond_dev_queue_xmit(bond, skb, bond->curr_active_slave->dev);
-
-out:
         if (res)
                 /* no suitable interface, frame not sent */
                 dev_kfree_skb(skb);
 
         read_unlock(&bond->curr_slave_lock);
-        read_unlock(&bond->lock);
+
         return NETDEV_TX_OK;
 }
 
@@ -4102,11 +4092,6 @@ static int bond_xmit_xor(struct sk_buff *skb, struct net_device *bond_dev)
         int i;
         int res = 1;
 
-        read_lock(&bond->lock);
-
-        if (!BOND_IS_OK(bond))
-                goto out;
-
         slave_no = bond->xmit_hash_policy(skb, bond->slave_cnt);
 
         bond_for_each_slave(bond, slave, i) {
@@ -4126,12 +4111,11 @@ static int bond_xmit_xor(struct sk_buff *skb, struct net_device *bond_dev)
                 }
         }
 
-out:
         if (res) {
                 /* no suitable interface, frame not sent */
                 dev_kfree_skb(skb);
         }
-        read_unlock(&bond->lock);
+
         return NETDEV_TX_OK;
 }
 
@@ -4146,11 +4130,6 @@ static int bond_xmit_broadcast(struct sk_buff *skb, struct net_device *bond_dev)
         int i;
         int res = 1;
 
-        read_lock(&bond->lock);
-
-        if (!BOND_IS_OK(bond))
-                goto out;
-
         read_lock(&bond->curr_slave_lock);
         start_at = bond->curr_active_slave;
         read_unlock(&bond->curr_slave_lock);
@@ -4189,7 +4168,6 @@ out:
                 dev_kfree_skb(skb);
 
         /* frame sent to all suitable interfaces */
-        read_unlock(&bond->lock);
         return NETDEV_TX_OK;
 }
 
@@ -4221,10 +4199,8 @@ static inline int bond_slave_override(struct bonding *bond,
         struct slave *slave = NULL;
         struct slave *check_slave;
 
-        read_lock(&bond->lock);
-
-        if (!BOND_IS_OK(bond) || !skb->queue_mapping)
-                goto out;
+        if (!skb->queue_mapping)
+                return 1;
 
         /* Find out if any slaves have the same mapping as this skb. */
         bond_for_each_slave(bond, check_slave, i) {
@@ -4240,8 +4216,6 @@ static inline int bond_slave_override(struct bonding *bond,
                 res = bond_dev_queue_xmit(bond, skb, slave->dev);
         }
 
-out:
-        read_unlock(&bond->lock);
         return res;
 }
 
@@ -4263,17 +4237,10 @@ static u16 bond_select_queue(struct net_device *dev, struct sk_buff *skb)
         return txq;
 }
 
-static netdev_tx_t bond_start_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t __bond_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct bonding *bond = netdev_priv(dev);
 
-        /*
-         * If we risk deadlock from transmitting this in the
-         * netpoll path, tell netpoll to queue the frame for later tx
-         */
-        if (is_netpoll_tx_blocked(dev))
-                return NETDEV_TX_BUSY;
-
         if (TX_QUEUE_OVERRIDE(bond->params.mode)) {
                 if (!bond_slave_override(bond, skb))
                         return NETDEV_TX_OK;
@@ -4303,6 +4270,29 @@ static netdev_tx_t bond_start_xmit(struct sk_buff *skb, struct net_device *dev)
         }
 }
 
+static netdev_tx_t bond_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+        struct bonding *bond = netdev_priv(dev);
+        netdev_tx_t ret = NETDEV_TX_OK;
+
+        /*
+         * If we risk deadlock from transmitting this in the
+         * netpoll path, tell netpoll to queue the frame for later tx
+         */
+        if (is_netpoll_tx_blocked(dev))
+                return NETDEV_TX_BUSY;
+
+        read_lock(&bond->lock);
+
+        if (bond->slave_cnt)
+                ret = __bond_start_xmit(skb, dev);
+        else
+                dev_kfree_skb(skb);
+
+        read_unlock(&bond->lock);
+
+        return ret;
+}
 
 /*
  * set bond mode specific net device operations