bonding: convert to list API and replace bond's custom list

This patch aims to remove struct bonding's first_slave and struct
slave's next and prev pointers, and replace them with the standard Linux
list API. The old macros are converted to list API as well and some new
primitives are available now. The checks if there're slaves that used
slave_cnt have been replaced by the list_empty macro.
Also a few small style fixes, changing longest -> shortest line in local
variable declarations, leaving an empty line before return and removing
unnecessary brackets.
This is the first step to gradual RCU conversion.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 26 insertions, 16 deletions

diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index 390061d09693..7d46fa832c1f 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -143,10 +143,9 @@ static inline struct bonding *__get_bond_by_port(struct port *port)
  */
 static inline struct port *__get_first_port(struct bonding *bond)
 {
-	if (bond->slave_cnt == 0)
-		return NULL;
+	struct slave *first_slave = bond_first_slave(bond);
 
-	return &(SLAVE_AD_INFO(bond->first_slave).port);
+	return first_slave ? &(SLAVE_AD_INFO(first_slave).port) : NULL;
 }
 
 /**
@@ -159,13 +158,16 @@ static inline struct port *__get_first_port(struct bonding *bond)
 static inline struct port *__get_next_port(struct port *port)
 {
 	struct bonding *bond = __get_bond_by_port(port);
-	struct slave *slave = port->slave;
+	struct slave *slave = port->slave, *slave_next;
 
 	// If there's no bond for this port, or this is the last slave
-	if ((bond == NULL) || (slave->next == bond->first_slave))
+	if (bond == NULL)
+		return NULL;
+	slave_next = bond_next_slave(bond, slave);
+	if (!slave_next || bond_is_first_slave(bond, slave_next))
 		return NULL;
 
-	return &(SLAVE_AD_INFO(slave->next).port);
+	return &(SLAVE_AD_INFO(slave_next).port);
 }
 
 /**
@@ -178,12 +180,14 @@ static inline struct port *__get_next_port(struct port *port)
 static inline struct aggregator *__get_first_agg(struct port *port)
 {
 	struct bonding *bond = __get_bond_by_port(port);
+	struct slave *first_slave;
 
 	// If there's no bond for this port, or bond has no slaves
-	if ((bond == NULL) || (bond->slave_cnt == 0))
+	if (bond == NULL)
 		return NULL;
+	first_slave = bond_first_slave(bond);
 
-	return &(SLAVE_AD_INFO(bond->first_slave).aggregator);
+	return first_slave ? &(SLAVE_AD_INFO(first_slave).aggregator) : NULL;
 }
 
 /**
@@ -195,14 +199,17 @@ static inline struct aggregator *__get_first_agg(struct port *port)
  */
 static inline struct aggregator *__get_next_agg(struct aggregator *aggregator)
 {
-	struct slave *slave = aggregator->slave;
+	struct slave *slave = aggregator->slave, *slave_next;
 	struct bonding *bond = bond_get_bond_by_slave(slave);
 
 	// If there's no bond for this aggregator, or this is the last slave
-	if ((bond == NULL) || (slave->next == bond->first_slave))
+	if (bond == NULL)
+		return NULL;
+	slave_next = bond_next_slave(bond, slave);
+	if (!slave_next || bond_is_first_slave(bond, slave_next))
 		return NULL;
 
-	return &(SLAVE_AD_INFO(slave->next).aggregator);
+	return &(SLAVE_AD_INFO(slave_next).aggregator);
 }
 
 /*
@@ -2110,7 +2117,7 @@ void bond_3ad_state_machine_handler(struct work_struct *work)
 	read_lock(&bond->lock);
 
 	//check if there are any slaves
-	if (bond->slave_cnt == 0)
+	if (list_empty(&bond->slave_list))
 		goto re_arm;
 
 	// check if agg_select_timer timer after initialize is timed out
@@ -2336,8 +2343,12 @@ void bond_3ad_handle_link_change(struct slave *slave, char link)
 int bond_3ad_set_carrier(struct bonding *bond)
 {
 	struct aggregator *active;
+	struct slave *first_slave;
 
-	active = __get_active_agg(&(SLAVE_AD_INFO(bond->first_slave).aggregator));
+	first_slave = bond_first_slave(bond);
+	if (!first_slave)
+		return 0;
+	active = __get_active_agg(&(SLAVE_AD_INFO(first_slave).aggregator));
 	if (active) {
 		/* are enough slaves available to consider link up? */
 		if (active->num_of_ports < bond->params.min_links) {
@@ -2432,7 +2443,7 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
 
 	slave_agg_no = bond->xmit_hash_policy(skb, slaves_in_agg);
 
-	bond_for_each_slave(bond, slave, i) {
+	bond_for_each_slave(bond, slave) {
 		struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator;
 
 		if (agg && (agg->aggregator_identifier == agg_id)) {
@@ -2501,7 +2512,6 @@ int bond_3ad_lacpdu_recv(const struct sk_buff *skb, struct bonding *bond,
  */
 void bond_3ad_update_lacp_rate(struct bonding *bond)
 {
-	int i;
 	struct slave *slave;
 	struct port *port = NULL;
 	int lacp_fast;
@@ -2509,7 +2519,7 @@ void bond_3ad_update_lacp_rate(struct bonding *bond)
 	write_lock_bh(&bond->lock);
 	lacp_fast = bond->params.lacp_fast;
 
-	bond_for_each_slave(bond, slave, i) {
+	bond_for_each_slave(bond, slave) {
 		port = &(SLAVE_AD_INFO(slave).port);
 		if (port->slave == NULL)
 			continue;