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slave_cnt have been replaced by the list_empty macro.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, 21 insertions, 22 deletions

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index ae02c19..0702e91 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -209,12 +209,12 @@ void bond_destroy_slave_symlinks(struct net_device *master,
 static ssize_t bonding_show_slaves(struct device *d,
 				   struct device_attribute *attr, char *buf)
 {
-	struct slave *slave;
-	int i, res = 0;
 	struct bonding *bond = to_bond(d);
+	struct slave *slave;
+	int res = 0;
 
 	read_lock(&bond->lock);
-	bond_for_each_slave(bond, slave, i) {
+	bond_for_each_slave(bond, slave) {
 		if (res > (PAGE_SIZE - IFNAMSIZ)) {
 			/* not enough space for another interface name */
 			if ((PAGE_SIZE - res) > 10)
@@ -227,6 +227,7 @@ static ssize_t bonding_show_slaves(struct device *d,
 	read_unlock(&bond->lock);
 	if (res)
 		buf[res-1] = '\n'; /* eat the leftover space */
+
 	return res;
 }
 
@@ -325,7 +326,7 @@ static ssize_t bonding_store_mode(struct device *d,
 		goto out;
 	}
 
-	if (bond->slave_cnt > 0) {
+	if (!list_empty(&bond->slave_list)) {
 		pr_err("unable to update mode of %s because it has slaves.\n",
 			bond->dev->name);
 		ret = -EPERM;
@@ -507,7 +508,7 @@ static ssize_t bonding_store_fail_over_mac(struct device *d,
 	if (!rtnl_trylock())
 		return restart_syscall();
 
-	if (bond->slave_cnt != 0) {
+	if (!list_empty(&bond->slave_list)) {
 		pr_err("%s: Can't alter fail_over_mac with slaves in bond.\n",
 		       bond->dev->name);
 		ret = -EPERM;
@@ -668,7 +669,7 @@ static ssize_t bonding_store_arp_targets(struct device *d,
 			 &newtarget);
 		/* not to race with bond_arp_rcv */
 		write_lock_bh(&bond->lock);
-		bond_for_each_slave(bond, slave, i)
+		bond_for_each_slave(bond, slave)
 			slave->target_last_arp_rx[ind] = jiffies;
 		targets[ind] = newtarget;
 		write_unlock_bh(&bond->lock);
@@ -694,7 +695,7 @@ static ssize_t bonding_store_arp_targets(struct device *d,
 			&newtarget);
 
 		write_lock_bh(&bond->lock);
-		bond_for_each_slave(bond, slave, i) {
+		bond_for_each_slave(bond, slave) {
 			targets_rx = slave->target_last_arp_rx;
 			j = ind;
 			for (; (j < BOND_MAX_ARP_TARGETS-1) && targets[j+1]; j++)
@@ -1085,10 +1086,9 @@ static ssize_t bonding_store_primary(struct device *d,
 				     struct device_attribute *attr,
 				     const char *buf, size_t count)
 {
-	int i;
-	struct slave *slave;
 	struct bonding *bond = to_bond(d);
 	char ifname[IFNAMSIZ];
+	struct slave *slave;
 
 	if (!rtnl_trylock())
 		return restart_syscall();
@@ -1114,7 +1114,7 @@ static ssize_t bonding_store_primary(struct device *d,
 		goto out;
 	}
 
-	bond_for_each_slave(bond, slave, i) {
+	bond_for_each_slave(bond, slave) {
 		if (strncmp(slave->dev->name, ifname, IFNAMSIZ) == 0) {
 			pr_info("%s: Setting %s as primary slave.\n",
 				bond->dev->name, slave->dev->name);
@@ -1260,16 +1260,14 @@ static ssize_t bonding_store_active_slave(struct device *d,
 					  struct device_attribute *attr,
 					  const char *buf, size_t count)
 {
-	int i;
-	struct slave *slave;
-	struct slave *old_active = NULL;
-	struct slave *new_active = NULL;
+	struct slave *slave, *old_active, *new_active;
 	struct bonding *bond = to_bond(d);
 	char ifname[IFNAMSIZ];
 
 	if (!rtnl_trylock())
 		return restart_syscall();
 
+	old_active = new_active = NULL;
 	block_netpoll_tx();
 	read_lock(&bond->lock);
 	write_lock_bh(&bond->curr_slave_lock);
@@ -1291,7 +1289,7 @@ static ssize_t bonding_store_active_slave(struct device *d,
 		goto out;
 	}
 
-	bond_for_each_slave(bond, slave, i) {
+	bond_for_each_slave(bond, slave) {
 		if (strncmp(slave->dev->name, ifname, IFNAMSIZ) == 0) {
 			old_active = bond->curr_active_slave;
 			new_active = slave;
@@ -1475,15 +1473,15 @@ static ssize_t bonding_show_queue_id(struct device *d,
 				     struct device_attribute *attr,
 				     char *buf)
 {
-	struct slave *slave;
-	int i, res = 0;
 	struct bonding *bond = to_bond(d);
+	struct slave *slave;
+	int res = 0;
 
 	if (!rtnl_trylock())
 		return restart_syscall();
 
 	read_lock(&bond->lock);
-	bond_for_each_slave(bond, slave, i) {
+	bond_for_each_slave(bond, slave) {
 		if (res > (PAGE_SIZE - IFNAMSIZ - 6)) {
 			/* not enough space for another interface_name:queue_id pair */
 			if ((PAGE_SIZE - res) > 10)
@@ -1498,6 +1496,7 @@ static ssize_t bonding_show_queue_id(struct device *d,
 	if (res)
 		buf[res-1] = '\n'; /* eat the leftover space */
 	rtnl_unlock();
+
 	return res;
 }
 
@@ -1512,7 +1511,7 @@ static ssize_t bonding_store_queue_id(struct device *d,
 	struct slave *slave, *update_slave;
 	struct bonding *bond = to_bond(d);
 	u16 qid;
-	int i, ret = count;
+	int ret = count;
 	char *delim;
 	struct net_device *sdev = NULL;
 
@@ -1547,7 +1546,7 @@ static ssize_t bonding_store_queue_id(struct device *d,
 
 	/* Search for thes slave and check for duplicate qids */
 	update_slave = NULL;
-	bond_for_each_slave(bond, slave, i) {
+	bond_for_each_slave(bond, slave) {
 		if (sdev == slave->dev)
 			/*
 			 * We don't need to check the matching
@@ -1599,8 +1598,8 @@ static ssize_t bonding_store_slaves_active(struct device *d,
 					   struct device_attribute *attr,
 					   const char *buf, size_t count)
 {
-	int i, new_value, ret = count;
 	struct bonding *bond = to_bond(d);
+	int new_value, ret = count;
 	struct slave *slave;
 
 	if (sscanf(buf, "%d", &new_value) != 1) {
@@ -1623,7 +1622,7 @@ static ssize_t bonding_store_slaves_active(struct device *d,
 	}
 
 	read_lock(&bond->lock);
-	bond_for_each_slave(bond, slave, i) {
+	bond_for_each_slave(bond, slave) {
 		if (!bond_is_active_slave(slave)) {
 			if (new_value)
 				slave->inactive = 0;