bonding: Convert more locks to _bh, acquire rtnl, for new locking

Convert more lock acquisitions to _bh flavor to avoid deadlock
with workqueue activity and add acquisition of RTNL in appropriate places.
Affects ALB mode, as well as core bonding functions and sysfs.

Signed-off-by: Andy Gospodarek <[e-mail]>
Signed-off-by: Jay Vosburgh <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/net/bonding/bond_alb.c

···
 
 static inline void _lock_tx_hashtbl(struct bonding *bond)
 {
-	spin_lock(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
+	spin_lock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
 }
 
 static inline void _unlock_tx_hashtbl(struct bonding *bond)
 {
-	spin_unlock(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
+	spin_unlock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
 }
 
 /* Caller must hold tx_hashtbl lock */
···
 /*********************** rlb specific functions ***************************/
 static inline void _lock_rx_hashtbl(struct bonding *bond)
 {
-	spin_lock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
+	spin_lock_bh(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
 }
 
 static inline void _unlock_rx_hashtbl(struct bonding *bond)
 {
-	spin_unlock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
+	spin_unlock_bh(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
 }
 
 /* when an ARP REPLY is received from a client update its info
···
 
 	_unlock_rx_hashtbl(bond);
 
-	write_lock(&bond->curr_slave_lock);
+	write_lock_bh(&bond->curr_slave_lock);
 
 	if (slave != bond->curr_active_slave) {
 		rlb_teach_disabled_mac_on_primary(bond, slave->dev->dev_addr);
 	}
 
-	write_unlock(&bond->curr_slave_lock);
+	write_unlock_bh(&bond->curr_slave_lock);
 }
 
 static void rlb_update_client(struct rlb_client_info *client_info)
···
 	/* caller must hold the bond lock for write since the mac addresses
 	 * are compared and may be swapped.
 	 */
-	write_lock_bh(&bond->lock);
+	read_lock(&bond->lock);
 
 	res = alb_handle_addr_collision_on_attach(bond, slave);
 
-	write_unlock_bh(&bond->lock);
+	read_unlock(&bond->lock);
 
 	if (res) {
 		return res;

drivers/net/bonding/bond_main.c

···
 */
 void bond_destroy(struct bonding *bond)
 {
+	unregister_netdevice(bond->dev);
 	bond_deinit(bond->dev);
 	bond_destroy_sysfs_entry(bond);
-	unregister_netdevice(bond->dev);
 }
 
 /*
···
 	info->bond_mode = bond->params.mode;
 	info->miimon = bond->params.miimon;
 
-	read_lock_bh(&bond->lock);
+	read_lock(&bond->lock);
 	info->num_slaves = bond->slave_cnt;
-	read_unlock_bh(&bond->lock);
+	read_unlock(&bond->lock);
 
 	return 0;
 }
···
 		return -ENODEV;
 	}
 
-	read_lock_bh(&bond->lock);
+	read_lock(&bond->lock);
 
 	bond_for_each_slave(bond, slave, i) {
 		if (i == (int)info->slave_id) {
···
 		}
 	}
 
-	read_unlock_bh(&bond->lock);
+	read_unlock(&bond->lock);
 
 	if (found) {
 		strcpy(info->slave_name, slave->dev->name);
···
 
 	/* make sure the bond won't be taken away */
 	read_lock(&dev_base_lock);
-	read_lock_bh(&bond->lock);
+	read_lock(&bond->lock);
 
 	if (*pos == 0) {
 		return SEQ_START_TOKEN;
···
 {
 	struct bonding *bond = seq->private;
 
-	read_unlock_bh(&bond->lock);
+	read_unlock(&bond->lock);
 	read_unlock(&dev_base_lock);
 }
 
···
 		if (mii->reg_num == 1) {
 			struct bonding *bond = bond_dev->priv;
 			mii->val_out = 0;
-			read_lock_bh(&bond->lock);
+			read_lock(&bond->lock);
 			read_lock(&bond->curr_slave_lock);
 			if (netif_carrier_ok(bond->dev)) {
 				mii->val_out = BMSR_LSTATUS;
 			}
 			read_unlock(&bond->curr_slave_lock);
-			read_unlock_bh(&bond->lock);
+			read_unlock(&bond->lock);
 		}
 
 		return 0;
···
 		bond_mc_list_destroy(bond);
 		/* Release the bonded slaves */
 		bond_release_all(bond_dev);
-		bond_deinit(bond_dev);
 		unregister_netdevice(bond_dev);
+		bond_deinit(bond_dev);
 	}
 
 #ifdef CONFIG_PROC_FS

drivers/net/bonding/bond_sysfs.c

···
 	int i, res = 0;
 	struct bonding *bond = to_bond(d);
 
-	read_lock_bh(&bond->lock);
+	read_lock(&bond->lock);
 	bond_for_each_slave(bond, slave, i) {
 		if (res > (PAGE_SIZE - IFNAMSIZ)) {
 			/* not enough space for another interface name */
···
 		}
 		res += sprintf(buf + res, "%s ", slave->dev->name);
 	}
-	read_unlock_bh(&bond->lock);
+	read_unlock(&bond->lock);
 	res += sprintf(buf + res, "\n");
 	res++;
 	return res;
···
 
 		/* Got a slave name in ifname.  Is it already in the list? */
 		found = 0;
-		read_lock_bh(&bond->lock);
+		read_lock(&bond->lock);
 		bond_for_each_slave(bond, slave, i)
 			if (strnicmp(slave->dev->name, ifname, IFNAMSIZ) == 0) {
 				printk(KERN_ERR DRV_NAME
 				       ": %s: Interface %s is already enslaved!\n",
 				       bond->dev->name, ifname);
 				ret = -EPERM;
-				read_unlock_bh(&bond->lock);
+				read_unlock(&bond->lock);
 				goto out;
 			}
 
-		read_unlock_bh(&bond->lock);
+		read_unlock(&bond->lock);
 		printk(KERN_INFO DRV_NAME ": %s: Adding slave %s.\n",
 		       bond->dev->name, ifname);
 		dev = dev_get_by_name(&init_net, ifname);
···
 	}
 out:
 	write_unlock_bh(&bond->lock);
+
+	rtnl_unlock();
+
 	return count;
 }
 static DEVICE_ATTR(primary, S_IRUGO | S_IWUSR, bonding_show_primary, bonding_store_primary);
···
 	struct bonding *bond = to_bond(d);
 	int count;
 
+	rtnl_lock();
 
 	read_lock(&bond->curr_slave_lock);
 	curr = bond->curr_active_slave;
···
 	}
 out:
 	write_unlock_bh(&bond->lock);
+	rtnl_unlock();
+
 	return count;
 
 }