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Phonet: convert devices list to RCU

Browse source 
Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Rémi Denis-Courmont 2009-11-18 10:08:26 -08:00 committed by David S. Miller
parent d90310243f
commit eeb74a9d45
3 changed files with 45 additions and 26 deletions
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2
include/net/phonet/pn_dev.h
View file

@ -25,7 +25,7 @@
struct phonet_device_list {
struct list_head list;
spinlock_t lock;
struct mutex lock;
};
struct phonet_device_list *phonet_device_list(struct net *net);

63
net/phonet/pn_dev.c
View file

@ -61,7 +61,8 @@ static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
pnd->netdev = dev;
bitmap_zero(pnd->addrs, 64);
list_add(&pnd->list, &pndevs->list);
BUG_ON(!mutex_is_locked(&pndevs->lock));
list_add_rcu(&pnd->list, &pndevs->list);
return pnd;
}
@ -70,6 +71,7 @@ static struct phonet_device *__phonet_get(struct net_device *dev)
struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
struct phonet_device *pnd;
BUG_ON(!mutex_is_locked(&pndevs->lock));
list_for_each_entry(pnd, &pndevs->list, list) {
if (pnd->netdev == dev)
return pnd;
@ -77,6 +79,18 @@ static struct phonet_device *__phonet_get(struct net_device *dev)
return NULL;
}
static struct phonet_device *__phonet_get_rcu(struct net_device *dev)
{
struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
struct phonet_device *pnd;
list_for_each_entry_rcu(pnd, &pndevs->list, list) {
if (pnd->netdev == dev)
return pnd;
}
return NULL;
}
static void phonet_device_destroy(struct net_device *dev)
{
struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
@ -84,11 +98,11 @@ static void phonet_device_destroy(struct net_device *dev)
ASSERT_RTNL();
spin_lock_bh(&pndevs->lock);
mutex_lock(&pndevs->lock);
pnd = __phonet_get(dev);
if (pnd)
list_del(&pnd->list);
spin_unlock_bh(&pndevs->lock);
list_del_rcu(&pnd->list);
mutex_unlock(&pndevs->lock);
if (pnd) {
u8 addr;
@ -106,8 +120,8 @@ struct net_device *phonet_device_get(struct net *net)
struct phonet_device *pnd;
struct net_device *dev = NULL;
spin_lock_bh(&pndevs->lock);
list_for_each_entry(pnd, &pndevs->list, list) {
rcu_read_lock();
list_for_each_entry_rcu(pnd, &pndevs->list, list) {
dev = pnd->netdev;
BUG_ON(!dev);
@ -118,7 +132,7 @@ struct net_device *phonet_device_get(struct net *net)
}
if (dev)
dev_hold(dev);
spin_unlock_bh(&pndevs->lock);
rcu_read_unlock();
return dev;
}
@ -128,7 +142,7 @@ int phonet_address_add(struct net_device *dev, u8 addr)
struct phonet_device *pnd;
int err = 0;
spin_lock_bh(&pndevs->lock);
mutex_lock(&pndevs->lock);
/* Find or create Phonet-specific device data */
pnd = __phonet_get(dev);
if (pnd == NULL)
@ -137,7 +151,7 @@ int phonet_address_add(struct net_device *dev, u8 addr)
err = -ENOMEM;
else if (test_and_set_bit(addr >> 2, pnd->addrs))
err = -EEXIST;
spin_unlock_bh(&pndevs->lock);
mutex_unlock(&pndevs->lock);
return err;
}
@ -147,27 +161,32 @@ int phonet_address_del(struct net_device *dev, u8 addr)
struct phonet_device *pnd;
int err = 0;
spin_lock_bh(&pndevs->lock);
mutex_lock(&pndevs->lock);
pnd = __phonet_get(dev);
if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs))
if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) {
err = -EADDRNOTAVAIL;
else if (bitmap_empty(pnd->addrs, 64)) {
list_del(&pnd->list);
pnd = NULL;
} else if (bitmap_empty(pnd->addrs, 64))
list_del_rcu(&pnd->list);
else
pnd = NULL;
mutex_unlock(&pndevs->lock);
if (pnd) {
synchronize_rcu();
kfree(pnd);
}
spin_unlock_bh(&pndevs->lock);
return err;
}
/* Gets a source address toward a destination, through a interface. */
u8 phonet_address_get(struct net_device *dev, u8 daddr)
{
struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
struct phonet_device *pnd;
u8 saddr;
spin_lock_bh(&pndevs->lock);
pnd = __phonet_get(dev);
rcu_read_lock();
pnd = __phonet_get_rcu(dev);
if (pnd) {
BUG_ON(bitmap_empty(pnd->addrs, 64));
@ -178,7 +197,7 @@ u8 phonet_address_get(struct net_device *dev, u8 daddr)
saddr = find_first_bit(pnd->addrs, 64) << 2;
} else
saddr = PN_NO_ADDR;
spin_unlock_bh(&pndevs->lock);
rcu_read_unlock();
if (saddr == PN_NO_ADDR) {
/* Fallback to another device */
@ -200,8 +219,8 @@ int phonet_address_lookup(struct net *net, u8 addr)
struct phonet_device *pnd;
int err = -EADDRNOTAVAIL;
spin_lock_bh(&pndevs->lock);
list_for_each_entry(pnd, &pndevs->list, list) {
rcu_read_lock();
list_for_each_entry_rcu(pnd, &pndevs->list, list) {
/* Don't allow unregistering devices! */
if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
((pnd->netdev->flags & IFF_UP)) != IFF_UP)
@ -213,7 +232,7 @@ int phonet_address_lookup(struct net *net, u8 addr)
}
}
found:
spin_unlock_bh(&pndevs->lock);
rcu_read_unlock();
return err;
}
@ -304,7 +323,7 @@ static int phonet_init_net(struct net *net)
}
INIT_LIST_HEAD(&pnn->pndevs.list);
spin_lock_init(&pnn->pndevs.lock);
mutex_init(&pnn->pndevs.lock);
mutex_init(&pnn->routes.lock);
net_assign_generic(net, phonet_net_id, pnn);
return 0;

6
net/phonet/pn_netlink.c
View file

@ -131,8 +131,8 @@ static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
int addr_idx = 0, addr_start_idx = cb->args[1];
pndevs = phonet_device_list(sock_net(skb->sk));
spin_lock_bh(&pndevs->lock);
list_for_each_entry(pnd, &pndevs->list, list) {
rcu_read_lock();
list_for_each_entry_rcu(pnd, &pndevs->list, list) {
u8 addr;
if (dev_idx > dev_start_idx)
@ -154,7 +154,7 @@ static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
}
out:
spin_unlock_bh(&pndevs->lock);
rcu_read_unlock();
cb->args[0] = dev_idx;
cb->args[1] = addr_idx;