mm: vmscan: distinguish between memcg triggering reclaim and memcg being scanned

[linux-2.6.git] / net / core / dev_addr_lists.c

/*
 * net/core/dev_addr_lists.c - Functions for handling net device lists
 * Copyright (c) 2010 Jiri Pirko <jpirko@redhat.com>
 *
 * This file contains functions for working with unicast, multicast and device
 * addresses lists.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/export.h>
#include <linux/list.h>
#include <linux/proc_fs.h>

/*
 * General list handling functions
 */

static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
                            unsigned char *addr, int addr_len,
                            unsigned char addr_type, bool global)
{
        struct netdev_hw_addr *ha;
        int alloc_size;

        if (addr_len > MAX_ADDR_LEN)
                return -EINVAL;

        list_for_each_entry(ha, &list->list, list) {
                if (!memcmp(ha->addr, addr, addr_len) &&
                    ha->type == addr_type) {
                        if (global) {
                                /* check if addr is already used as global */
                                if (ha->global_use)
                                        return 0;
                                else
                                        ha->global_use = true;
                        }
                        ha->refcount++;
                        return 0;
                }
        }


        alloc_size = sizeof(*ha);
        if (alloc_size < L1_CACHE_BYTES)
                alloc_size = L1_CACHE_BYTES;
        ha = kmalloc(alloc_size, GFP_ATOMIC);
        if (!ha)
                return -ENOMEM;
        memcpy(ha->addr, addr, addr_len);
        ha->type = addr_type;
        ha->refcount = 1;
        ha->global_use = global;
        ha->synced = false;
        list_add_tail_rcu(&ha->list, &list->list);
        list->count++;
        return 0;
}

static int __hw_addr_add(struct netdev_hw_addr_list *list, unsigned char *addr,
                         int addr_len, unsigned char addr_type)
{
        return __hw_addr_add_ex(list, addr, addr_len, addr_type, false);
}

static int __hw_addr_del_ex(struct netdev_hw_addr_list *list,
                            unsigned char *addr, int addr_len,
                            unsigned char addr_type, bool global)
{
        struct netdev_hw_addr *ha;

        list_for_each_entry(ha, &list->list, list) {
                if (!memcmp(ha->addr, addr, addr_len) &&
                    (ha->type == addr_type || !addr_type)) {
                        if (global) {
                                if (!ha->global_use)
                                        break;
                                else
                                        ha->global_use = false;
                        }
                        if (--ha->refcount)
                                return 0;
                        list_del_rcu(&ha->list);
                        kfree_rcu(ha, rcu_head);
                        list->count--;
                        return 0;
                }
        }
        return -ENOENT;
}

static int __hw_addr_del(struct netdev_hw_addr_list *list, unsigned char *addr,
                         int addr_len, unsigned char addr_type)
{
        return __hw_addr_del_ex(list, addr, addr_len, addr_type, false);
}

int __hw_addr_add_multiple(struct netdev_hw_addr_list *to_list,
                           struct netdev_hw_addr_list *from_list,
                           int addr_len, unsigned char addr_type)
{
        int err;
        struct netdev_hw_addr *ha, *ha2;
        unsigned char type;

        list_for_each_entry(ha, &from_list->list, list) {
                type = addr_type ? addr_type : ha->type;
                err = __hw_addr_add(to_list, ha->addr, addr_len, type);
                if (err)
                        goto unroll;
        }
        return 0;

unroll:
        list_for_each_entry(ha2, &from_list->list, list) {
                if (ha2 == ha)
                        break;
                type = addr_type ? addr_type : ha2->type;
                __hw_addr_del(to_list, ha2->addr, addr_len, type);
        }
        return err;
}
EXPORT_SYMBOL(__hw_addr_add_multiple);

void __hw_addr_del_multiple(struct netdev_hw_addr_list *to_list,
                            struct netdev_hw_addr_list *from_list,
                            int addr_len, unsigned char addr_type)
{
        struct netdev_hw_addr *ha;
        unsigned char type;

        list_for_each_entry(ha, &from_list->list, list) {
                type = addr_type ? addr_type : ha->type;
                __hw_addr_del(to_list, ha->addr, addr_len, type);
        }
}
EXPORT_SYMBOL(__hw_addr_del_multiple);

int __hw_addr_sync(struct netdev_hw_addr_list *to_list,
                   struct netdev_hw_addr_list *from_list,
                   int addr_len)
{
        int err = 0;
        struct netdev_hw_addr *ha, *tmp;

        list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
                if (!ha->synced) {
                        err = __hw_addr_add(to_list, ha->addr,
                                            addr_len, ha->type);
                        if (err)
                                break;
                        ha->synced = true;
                        ha->refcount++;
                } else if (ha->refcount == 1) {
                        __hw_addr_del(to_list, ha->addr, addr_len, ha->type);
                        __hw_addr_del(from_list, ha->addr, addr_len, ha->type);
                }
        }
        return err;
}
EXPORT_SYMBOL(__hw_addr_sync);

void __hw_addr_unsync(struct netdev_hw_addr_list *to_list,
                      struct netdev_hw_addr_list *from_list,
                      int addr_len)
{
        struct netdev_hw_addr *ha, *tmp;

        list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
                if (ha->synced) {
                        __hw_addr_del(to_list, ha->addr,
                                      addr_len, ha->type);
                        ha->synced = false;
                        __hw_addr_del(from_list, ha->addr,
                                      addr_len, ha->type);
                }
        }
}
EXPORT_SYMBOL(__hw_addr_unsync);

void __hw_addr_flush(struct netdev_hw_addr_list *list)
{
        struct netdev_hw_addr *ha, *tmp;

        list_for_each_entry_safe(ha, tmp, &list->list, list) {
                list_del_rcu(&ha->list);
                kfree_rcu(ha, rcu_head);
        }
        list->count = 0;
}
EXPORT_SYMBOL(__hw_addr_flush);

void __hw_addr_init(struct netdev_hw_addr_list *list)
{
        INIT_LIST_HEAD(&list->list);
        list->count = 0;
}
EXPORT_SYMBOL(__hw_addr_init);

/*
 * Device addresses handling functions
 */

/**
 *      dev_addr_flush - Flush device address list
 *      @dev: device
 *
 *      Flush device address list and reset ->dev_addr.
 *
 *      The caller must hold the rtnl_mutex.
 */
void dev_addr_flush(struct net_device *dev)
{
        /* rtnl_mutex must be held here */

        __hw_addr_flush(&dev->dev_addrs);
        dev->dev_addr = NULL;
}
EXPORT_SYMBOL(dev_addr_flush);

/**
 *      dev_addr_init - Init device address list
 *      @dev: device
 *
 *      Init device address list and create the first element,
 *      used by ->dev_addr.
 *
 *      The caller must hold the rtnl_mutex.
 */
int dev_addr_init(struct net_device *dev)
{
        unsigned char addr[MAX_ADDR_LEN];
        struct netdev_hw_addr *ha;
        int err;

        /* rtnl_mutex must be held here */

        __hw_addr_init(&dev->dev_addrs);
        memset(addr, 0, sizeof(addr));
        err = __hw_addr_add(&dev->dev_addrs, addr, sizeof(addr),
                            NETDEV_HW_ADDR_T_LAN);
        if (!err) {
                /*
                 * Get the first (previously created) address from the list
                 * and set dev_addr pointer to this location.
                 */
                ha = list_first_entry(&dev->dev_addrs.list,
                                      struct netdev_hw_addr, list);
                dev->dev_addr = ha->addr;
        }
        return err;
}
EXPORT_SYMBOL(dev_addr_init);

/**
 *      dev_addr_add - Add a device address
 *      @dev: device
 *      @addr: address to add
 *      @addr_type: address type
 *
 *      Add a device address to the device or increase the reference count if
 *      it already exists.
 *
 *      The caller must hold the rtnl_mutex.
 */
int dev_addr_add(struct net_device *dev, unsigned char *addr,
                 unsigned char addr_type)
{
        int err;

        ASSERT_RTNL();

        err = __hw_addr_add(&dev->dev_addrs, addr, dev->addr_len, addr_type);
        if (!err)
                call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
        return err;
}
EXPORT_SYMBOL(dev_addr_add);

/**
 *      dev_addr_del - Release a device address.
 *      @dev: device
 *      @addr: address to delete
 *      @addr_type: address type
 *
 *      Release reference to a device address and remove it from the device
 *      if the reference count drops to zero.
 *
 *      The caller must hold the rtnl_mutex.
 */
int dev_addr_del(struct net_device *dev, unsigned char *addr,
                 unsigned char addr_type)
{
        int err;
        struct netdev_hw_addr *ha;

        ASSERT_RTNL();

        /*
         * We can not remove the first address from the list because
         * dev->dev_addr points to that.
         */
        ha = list_first_entry(&dev->dev_addrs.list,
                              struct netdev_hw_addr, list);
        if (ha->addr == dev->dev_addr && ha->refcount == 1)
                return -ENOENT;

        err = __hw_addr_del(&dev->dev_addrs, addr, dev->addr_len,
                            addr_type);
        if (!err)
                call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
        return err;
}
EXPORT_SYMBOL(dev_addr_del);

/**
 *      dev_addr_add_multiple - Add device addresses from another device
 *      @to_dev: device to which addresses will be added
 *      @from_dev: device from which addresses will be added
 *      @addr_type: address type - 0 means type will be used from from_dev
 *
 *      Add device addresses of the one device to another.
 **
 *      The caller must hold the rtnl_mutex.
 */
int dev_addr_add_multiple(struct net_device *to_dev,
                          struct net_device *from_dev,
                          unsigned char addr_type)
{
        int err;

        ASSERT_RTNL();

        if (from_dev->addr_len != to_dev->addr_len)
                return -EINVAL;
        err = __hw_addr_add_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
                                     to_dev->addr_len, addr_type);
        if (!err)
                call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
        return err;
}
EXPORT_SYMBOL(dev_addr_add_multiple);

/**
 *      dev_addr_del_multiple - Delete device addresses by another device
 *      @to_dev: device where the addresses will be deleted
 *      @from_dev: device supplying the addresses to be deleted
 *      @addr_type: address type - 0 means type will be used from from_dev
 *
 *      Deletes addresses in to device by the list of addresses in from device.
 *
 *      The caller must hold the rtnl_mutex.
 */
int dev_addr_del_multiple(struct net_device *to_dev,
                          struct net_device *from_dev,
                          unsigned char addr_type)
{
        ASSERT_RTNL();

        if (from_dev->addr_len != to_dev->addr_len)
                return -EINVAL;
        __hw_addr_del_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
                               to_dev->addr_len, addr_type);
        call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
        return 0;
}
EXPORT_SYMBOL(dev_addr_del_multiple);

/*
 * Unicast list handling functions
 */

/**
 *      dev_uc_add - Add a secondary unicast address
 *      @dev: device
 *      @addr: address to add
 *
 *      Add a secondary unicast address to the device or increase
 *      the reference count if it already exists.
 */
int dev_uc_add(struct net_device *dev, unsigned char *addr)
{
        int err;

        netif_addr_lock_bh(dev);
        err = __hw_addr_add(&dev->uc, addr, dev->addr_len,
                            NETDEV_HW_ADDR_T_UNICAST);
        if (!err)
                __dev_set_rx_mode(dev);
        netif_addr_unlock_bh(dev);
        return err;
}
EXPORT_SYMBOL(dev_uc_add);

/**
 *      dev_uc_del - Release secondary unicast address.
 *      @dev: device
 *      @addr: address to delete
 *
 *      Release reference to a secondary unicast address and remove it
 *      from the device if the reference count drops to zero.
 */
int dev_uc_del(struct net_device *dev, unsigned char *addr)
{
        int err;

        netif_addr_lock_bh(dev);
        err = __hw_addr_del(&dev->uc, addr, dev->addr_len,
                            NETDEV_HW_ADDR_T_UNICAST);
        if (!err)
                __dev_set_rx_mode(dev);
        netif_addr_unlock_bh(dev);
        return err;
}
EXPORT_SYMBOL(dev_uc_del);

/**
 *      dev_uc_sync - Synchronize device's unicast list to another device
 *      @to: destination device
 *      @from: source device
 *
 *      Add newly added addresses to the destination device and release
 *      addresses that have no users left. The source device must be
 *      locked by netif_addr_lock_bh.
 *
 *      This function is intended to be called from the dev->set_rx_mode
 *      function of layered software devices.
 */
int dev_uc_sync(struct net_device *to, struct net_device *from)
{
        int err = 0;

        if (to->addr_len != from->addr_len)
                return -EINVAL;

        netif_addr_lock_nested(to);
        err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
        if (!err)
                __dev_set_rx_mode(to);
        netif_addr_unlock(to);
        return err;
}
EXPORT_SYMBOL(dev_uc_sync);

/**
 *      dev_uc_unsync - Remove synchronized addresses from the destination device
 *      @to: destination device
 *      @from: source device
 *
 *      Remove all addresses that were added to the destination device by
 *      dev_uc_sync(). This function is intended to be called from the
 *      dev->stop function of layered software devices.
 */
void dev_uc_unsync(struct net_device *to, struct net_device *from)
{
        if (to->addr_len != from->addr_len)
                return;

        netif_addr_lock_bh(from);
        netif_addr_lock_nested(to);
        __hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
        __dev_set_rx_mode(to);
        netif_addr_unlock(to);
        netif_addr_unlock_bh(from);
}
EXPORT_SYMBOL(dev_uc_unsync);

/**
 *      dev_uc_flush - Flush unicast addresses
 *      @dev: device
 *
 *      Flush unicast addresses.
 */
void dev_uc_flush(struct net_device *dev)
{
        netif_addr_lock_bh(dev);
        __hw_addr_flush(&dev->uc);
        netif_addr_unlock_bh(dev);
}
EXPORT_SYMBOL(dev_uc_flush);

/**
 *      dev_uc_flush - Init unicast address list
 *      @dev: device
 *
 *      Init unicast address list.
 */
void dev_uc_init(struct net_device *dev)
{
        __hw_addr_init(&dev->uc);
}
EXPORT_SYMBOL(dev_uc_init);

/*
 * Multicast list handling functions
 */

static int __dev_mc_add(struct net_device *dev, unsigned char *addr,
                        bool global)
{
        int err;

        netif_addr_lock_bh(dev);
        err = __hw_addr_add_ex(&dev->mc, addr, dev->addr_len,
                               NETDEV_HW_ADDR_T_MULTICAST, global);
        if (!err)
                __dev_set_rx_mode(dev);
        netif_addr_unlock_bh(dev);
        return err;
}
/**
 *      dev_mc_add - Add a multicast address
 *      @dev: device
 *      @addr: address to add
 *
 *      Add a multicast address to the device or increase
 *      the reference count if it already exists.
 */
int dev_mc_add(struct net_device *dev, unsigned char *addr)
{
        return __dev_mc_add(dev, addr, false);
}
EXPORT_SYMBOL(dev_mc_add);

/**
 *      dev_mc_add_global - Add a global multicast address
 *      @dev: device
 *      @addr: address to add
 *
 *      Add a global multicast address to the device.
 */
int dev_mc_add_global(struct net_device *dev, unsigned char *addr)
{
        return __dev_mc_add(dev, addr, true);
}
EXPORT_SYMBOL(dev_mc_add_global);

static int __dev_mc_del(struct net_device *dev, unsigned char *addr,
                        bool global)
{
        int err;

        netif_addr_lock_bh(dev);
        err = __hw_addr_del_ex(&dev->mc, addr, dev->addr_len,
                               NETDEV_HW_ADDR_T_MULTICAST, global);
        if (!err)
                __dev_set_rx_mode(dev);
        netif_addr_unlock_bh(dev);
        return err;
}

/**
 *      dev_mc_del - Delete a multicast address.
 *      @dev: device
 *      @addr: address to delete
 *
 *      Release reference to a multicast address and remove it
 *      from the device if the reference count drops to zero.
 */
int dev_mc_del(struct net_device *dev, unsigned char *addr)
{
        return __dev_mc_del(dev, addr, false);
}
EXPORT_SYMBOL(dev_mc_del);

/**
 *      dev_mc_del_global - Delete a global multicast address.
 *      @dev: device
 *      @addr: address to delete
 *
 *      Release reference to a multicast address and remove it
 *      from the device if the reference count drops to zero.
 */
int dev_mc_del_global(struct net_device *dev, unsigned char *addr)
{
        return __dev_mc_del(dev, addr, true);
}
EXPORT_SYMBOL(dev_mc_del_global);

/**
 *      dev_mc_sync - Synchronize device's unicast list to another device
 *      @to: destination device
 *      @from: source device
 *
 *      Add newly added addresses to the destination device and release
 *      addresses that have no users left. The source device must be
 *      locked by netif_addr_lock_bh.
 *
 *      This function is intended to be called from the ndo_set_rx_mode
 *      function of layered software devices.
 */
int dev_mc_sync(struct net_device *to, struct net_device *from)
{
        int err = 0;

        if (to->addr_len != from->addr_len)
                return -EINVAL;

        netif_addr_lock_nested(to);
        err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
        if (!err)
                __dev_set_rx_mode(to);
        netif_addr_unlock(to);
        return err;
}
EXPORT_SYMBOL(dev_mc_sync);

/**
 *      dev_mc_unsync - Remove synchronized addresses from the destination device
 *      @to: destination device
 *      @from: source device
 *
 *      Remove all addresses that were added to the destination device by
 *      dev_mc_sync(). This function is intended to be called from the
 *      dev->stop function of layered software devices.
 */
void dev_mc_unsync(struct net_device *to, struct net_device *from)
{
        if (to->addr_len != from->addr_len)
                return;

        netif_addr_lock_bh(from);
        netif_addr_lock_nested(to);
        __hw_addr_unsync(&to->mc, &from->mc, to->addr_len);
        __dev_set_rx_mode(to);
        netif_addr_unlock(to);
        netif_addr_unlock_bh(from);
}
EXPORT_SYMBOL(dev_mc_unsync);

/**
 *      dev_mc_flush - Flush multicast addresses
 *      @dev: device
 *
 *      Flush multicast addresses.
 */
void dev_mc_flush(struct net_device *dev)
{
        netif_addr_lock_bh(dev);
        __hw_addr_flush(&dev->mc);
        netif_addr_unlock_bh(dev);
}
EXPORT_SYMBOL(dev_mc_flush);

/**
 *      dev_mc_flush - Init multicast address list
 *      @dev: device
 *
 *      Init multicast address list.
 */
void dev_mc_init(struct net_device *dev)
{
        __hw_addr_init(&dev->mc);
}
EXPORT_SYMBOL(dev_mc_init);

#ifdef CONFIG_PROC_FS
#include <linux/seq_file.h>

static int dev_mc_seq_show(struct seq_file *seq, void *v)
{
        struct netdev_hw_addr *ha;
        struct net_device *dev = v;

        if (v == SEQ_START_TOKEN)
                return 0;

        netif_addr_lock_bh(dev);
        netdev_for_each_mc_addr(ha, dev) {
                int i;

                seq_printf(seq, "%-4d %-15s %-5d %-5d ", dev->ifindex,
                           dev->name, ha->refcount, ha->global_use);

                for (i = 0; i < dev->addr_len; i++)
                        seq_printf(seq, "%02x", ha->addr[i]);

                seq_putc(seq, '\n');
        }
        netif_addr_unlock_bh(dev);
        return 0;
}

static const struct seq_operations dev_mc_seq_ops = {
        .start = dev_seq_start,
        .next  = dev_seq_next,
        .stop  = dev_seq_stop,
        .show  = dev_mc_seq_show,
};

static int dev_mc_seq_open(struct inode *inode, struct file *file)
{
        return dev_seq_open_ops(inode, file, &dev_mc_seq_ops);
}

static const struct file_operations dev_mc_seq_fops = {
        .owner   = THIS_MODULE,
        .open    = dev_mc_seq_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
        .release = seq_release_net,
};

#endif

static int __net_init dev_mc_net_init(struct net *net)
{
        if (!proc_net_fops_create(net, "dev_mcast", 0, &dev_mc_seq_fops))
                return -ENOMEM;
        return 0;
}

static void __net_exit dev_mc_net_exit(struct net *net)
{
        proc_net_remove(net, "dev_mcast");
}

static struct pernet_operations __net_initdata dev_mc_net_ops = {
        .init = dev_mc_net_init,
        .exit = dev_mc_net_exit,
};

void __init dev_mcast_init(void)
{
        register_pernet_subsys(&dev_mc_net_ops);
}