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Commit 15077228 authored by Nikolay Aleksandrov's avatar Nikolay Aleksandrov Committed by David S. Miller
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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: default avatarNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 78a646ce

drivers/net/bonding/bond_main.c

+51 −67
Original line number Diff line number Diff line
@@ -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;

}

drivers/net/bonding/bonding.h

+10 −0
Original line number Diff line number Diff line
@@ -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);