netns: make nsid_lock per net

The spinlock is used to protect netns_ids which is per net,
so there is no need to use a global spinlock.

Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
WANG Cong 2015-05-15 14:47:32 -07:00 committed by David S. Miller
parent 4ab7f91381
commit de133464c9
2 changed files with 17 additions and 16 deletions

View file

@ -58,6 +58,7 @@ struct net {
struct list_head exit_list; /* Use only net_mutex */
struct user_namespace *user_ns; /* Owning user namespace */
spinlock_t nsid_lock;
struct idr netns_ids;
struct ns_common ns;

View file

@ -28,7 +28,6 @@
static LIST_HEAD(pernet_list);
static struct list_head *first_device = &pernet_list;
DEFINE_MUTEX(net_mutex);
static DEFINE_SPINLOCK(nsid_lock);
LIST_HEAD(net_namespace_list);
EXPORT_SYMBOL_GPL(net_namespace_list);
@ -218,10 +217,10 @@ int peernet2id_alloc(struct net *net, struct net *peer)
bool alloc;
int id;
spin_lock_irqsave(&nsid_lock, flags);
spin_lock_irqsave(&net->nsid_lock, flags);
alloc = atomic_read(&peer->count) == 0 ? false : true;
id = __peernet2id_alloc(net, peer, &alloc);
spin_unlock_irqrestore(&nsid_lock, flags);
spin_unlock_irqrestore(&net->nsid_lock, flags);
if (alloc && id >= 0)
rtnl_net_notifyid(net, RTM_NEWNSID, id);
return id;
@ -234,9 +233,9 @@ int peernet2id(struct net *net, struct net *peer)
unsigned long flags;
int id;
spin_lock_irqsave(&nsid_lock, flags);
spin_lock_irqsave(&net->nsid_lock, flags);
id = __peernet2id(net, peer);
spin_unlock_irqrestore(&nsid_lock, flags);
spin_unlock_irqrestore(&net->nsid_lock, flags);
return id;
}
@ -257,11 +256,11 @@ struct net *get_net_ns_by_id(struct net *net, int id)
return NULL;
rcu_read_lock();
spin_lock_irqsave(&nsid_lock, flags);
spin_lock_irqsave(&net->nsid_lock, flags);
peer = idr_find(&net->netns_ids, id);
if (peer)
get_net(peer);
spin_unlock_irqrestore(&nsid_lock, flags);
spin_unlock_irqrestore(&net->nsid_lock, flags);
rcu_read_unlock();
return peer;
@ -282,6 +281,7 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
net->dev_base_seq = 1;
net->user_ns = user_ns;
idr_init(&net->netns_ids);
spin_lock_init(&net->nsid_lock);
list_for_each_entry(ops, &pernet_list, list) {
error = ops_init(ops, net);
@ -404,17 +404,17 @@ static void cleanup_net(struct work_struct *work)
for_each_net(tmp) {
int id;
spin_lock_irq(&nsid_lock);
spin_lock_irq(&tmp->nsid_lock);
id = __peernet2id(tmp, net);
if (id >= 0)
idr_remove(&tmp->netns_ids, id);
spin_unlock_irq(&nsid_lock);
spin_unlock_irq(&tmp->nsid_lock);
if (id >= 0)
rtnl_net_notifyid(tmp, RTM_DELNSID, id);
}
spin_lock_irq(&nsid_lock);
spin_lock_irq(&net->nsid_lock);
idr_destroy(&net->netns_ids);
spin_unlock_irq(&nsid_lock);
spin_unlock_irq(&net->nsid_lock);
}
rtnl_unlock();
@ -563,15 +563,15 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
if (IS_ERR(peer))
return PTR_ERR(peer);
spin_lock_irqsave(&nsid_lock, flags);
spin_lock_irqsave(&net->nsid_lock, flags);
if (__peernet2id(net, peer) >= 0) {
spin_unlock_irqrestore(&nsid_lock, flags);
spin_unlock_irqrestore(&net->nsid_lock, flags);
err = -EEXIST;
goto out;
}
err = alloc_netid(net, peer, nsid);
spin_unlock_irqrestore(&nsid_lock, flags);
spin_unlock_irqrestore(&net->nsid_lock, flags);
if (err >= 0) {
rtnl_net_notifyid(net, RTM_NEWNSID, err);
err = 0;
@ -695,9 +695,9 @@ static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
};
unsigned long flags;
spin_lock_irqsave(&nsid_lock, flags);
spin_lock_irqsave(&net->nsid_lock, flags);
idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
spin_unlock_irqrestore(&nsid_lock, flags);
spin_unlock_irqrestore(&net->nsid_lock, flags);
cb->args[0] = net_cb.idx;
return skb->len;