From 15077228cab68e5e8c3cbf26a7f6ebacfac4c829 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Thu, 1 Aug 2013 16:54:50 +0200 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- drivers/net/bonding/bond_main.c | 118 ++++++++++++++------------------ drivers/net/bonding/bonding.h | 10 +++ 2 files changed, 61 insertions(+), 67 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index aa9da006fa68..5eee95c3b172 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3795,12 +3795,50 @@ unwind: 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 @@ static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *bond_dev * 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 @@ static int bond_xmit_activebackup(struct sk_buff *skb, struct net_device *bond_d { 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_activebackup(struct sk_buff *skb, struct net_device *bond_d 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 cfd9b493f5b0..0995974c71ac 100644 --- a/drivers/net/bonding/bonding.h +++ b/drivers/net/bonding/bonding.h @@ -426,10 +426,20 @@ static inline __be32 bond_confirm_addr(struct net_device *dev, __be32 dst, __be3 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); -- 2.30.2