bonding: factor out slave id tx code and simplify xmit paths
I factored out the tx xmit code which relies on slave id in
bond_xmit_slave_id. It is global because later it can be used also in
3ad mode xmit. Unnecessary obvious comments are removed. Active-backup
mode is simplified because bond_dev_queue_xmit always consumes the skb.
bond_xmit_xor becomes one line because of bond_xmit_slave_id.
bond_for_each_slave_from is not used in bond_xmit_slave_id because later
when RCU is used we can avoid important race condition by using standard
rculist routines.
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index aa9da00..5eee95c 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -3795,12 +3795,50 @@
return res;
}
+/**
+ * bond_xmit_slave_id - transmit skb through slave with slave_id
+ * @bond: bonding device that is transmitting
+ * @skb: buffer to transmit
+ * @slave_id: slave id up to slave_cnt-1 through which to transmit
+ *
+ * This function tries to transmit through slave with slave_id but in case
+ * it fails, it tries to find the first available slave for transmission.
+ * The skb is consumed in all cases, thus the function is void.
+ */
+void bond_xmit_slave_id(struct bonding *bond, struct sk_buff *skb, int slave_id)
+{
+ struct slave *slave;
+ int i = slave_id;
+
+ /* Here we start from the slave with slave_id */
+ bond_for_each_slave(bond, slave) {
+ if (--i < 0) {
+ if (slave_can_tx(slave)) {
+ bond_dev_queue_xmit(bond, skb, slave->dev);
+ return;
+ }
+ }
+ }
+
+ /* Here we start from the first slave up to slave_id */
+ i = slave_id;
+ bond_for_each_slave(bond, slave) {
+ if (--i < 0)
+ break;
+ if (slave_can_tx(slave)) {
+ bond_dev_queue_xmit(bond, skb, slave->dev);
+ return;
+ }
+ }
+ /* no slave that can tx has been found */
+ kfree_skb(skb);
+}
+
static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *bond_dev)
{
struct bonding *bond = netdev_priv(bond_dev);
- struct slave *slave, *start_at;
- int i, slave_no, res = 1;
struct iphdr *iph = ip_hdr(skb);
+ struct slave *slave;
/*
* Start with the curr_active_slave that joined the bond as the
@@ -3809,46 +3847,20 @@
* send the join/membership reports. The curr_active_slave found
* will send all of this type of traffic.
*/
- if ((iph->protocol == IPPROTO_IGMP) &&
- (skb->protocol == htons(ETH_P_IP))) {
+ if (iph->protocol == IPPROTO_IGMP && skb->protocol == htons(ETH_P_IP)) {
slave = bond->curr_active_slave;
- if (!slave)
- goto out;
+ if (slave && slave_can_tx(slave))
+ bond_dev_queue_xmit(bond, skb, slave->dev);
+ else
+ bond_xmit_slave_id(bond, skb, 0);
} else {
- /*
- * Concurrent TX may collide on rr_tx_counter; we accept
- * that as being rare enough not to justify using an
- * atomic op here.
- */
- slave_no = bond->rr_tx_counter++ % bond->slave_cnt;
-
- bond_for_each_slave(bond, slave) {
- slave_no--;
- if (slave_no < 0)
- break;
- }
- }
-
- start_at = slave;
- bond_for_each_slave_from(bond, slave, i, start_at) {
- if (IS_UP(slave->dev) &&
- (slave->link == BOND_LINK_UP) &&
- bond_is_active_slave(slave)) {
- res = bond_dev_queue_xmit(bond, skb, slave->dev);
- break;
- }
- }
-
-out:
- if (res) {
- /* no suitable interface, frame not sent */
- kfree_skb(skb);
+ bond_xmit_slave_id(bond, skb,
+ bond->rr_tx_counter++ % bond->slave_cnt);
}
return NETDEV_TX_OK;
}
-
/*
* in active-backup mode, we know that bond->curr_active_slave is always valid if
* the bond has a usable interface.
@@ -3857,14 +3869,11 @@
{
struct bonding *bond = netdev_priv(bond_dev);
struct slave *slave;
- int res = 1;
slave = bond->curr_active_slave;
if (slave)
- res = bond_dev_queue_xmit(bond, skb, slave->dev);
-
- if (res)
- /* no suitable interface, frame not sent */
+ bond_dev_queue_xmit(bond, skb, slave->dev);
+ else
kfree_skb(skb);
return NETDEV_TX_OK;
@@ -3878,34 +3887,9 @@
static int bond_xmit_xor(struct sk_buff *skb, struct net_device *bond_dev)
{
struct bonding *bond = netdev_priv(bond_dev);
- struct slave *slave, *start_at;
- int slave_no;
- int i;
- int res = 1;
- slave_no = bond->xmit_hash_policy(skb, bond->slave_cnt);
-
- bond_for_each_slave(bond, slave) {
- slave_no--;
- if (slave_no < 0)
- break;
- }
-
- start_at = slave;
-
- bond_for_each_slave_from(bond, slave, i, start_at) {
- if (IS_UP(slave->dev) &&
- (slave->link == BOND_LINK_UP) &&
- bond_is_active_slave(slave)) {
- res = bond_dev_queue_xmit(bond, skb, slave->dev);
- break;
- }
- }
-
- if (res) {
- /* no suitable interface, frame not sent */
- kfree_skb(skb);
- }
+ bond_xmit_slave_id(bond, skb,
+ bond->xmit_hash_policy(skb, bond->slave_cnt));
return NETDEV_TX_OK;
}
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index cfd9b49..0995974 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -426,10 +426,20 @@
return addr;
}
+static inline bool slave_can_tx(struct slave *slave)
+{
+ if (IS_UP(slave->dev) && slave->link == BOND_LINK_UP &&
+ bond_is_active_slave(slave))
+ return true;
+ else
+ return false;
+}
+
struct bond_net;
struct vlan_entry *bond_next_vlan(struct bonding *bond, struct vlan_entry *curr);
int bond_dev_queue_xmit(struct bonding *bond, struct sk_buff *skb, struct net_device *slave_dev);
+void bond_xmit_slave_id(struct bonding *bond, struct sk_buff *skb, int slave_id);
int bond_create(struct net *net, const char *name);
int bond_create_sysfs(struct bond_net *net);
void bond_destroy_sysfs(struct bond_net *net);