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Commit de133464 authored by WANG Cong's avatar WANG Cong Committed by David S. Miller
Browse files

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: default avatarCong Wang <xiyou.wangcong@gmail.com>
Acked-by: default avatarNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4ab7f913

include/net/net_namespace.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

net/core/net_namespace.c

+16 −16
Original line number Diff line number Diff line
@@ -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;