netns: revert "netns: avoid disabling irq for netns id"

[cascardo/linux.git] / net / core / net_namespace.c

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 42bdda0..f61c0e0 100644 (file)
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -215,13 +215,14 @@ static void rtnl_net_notifyid(struct net *net, int cmd, int id);
  */
 int peernet2id_alloc(struct net *net, struct net *peer)
 {
+       unsigned long flags;
        bool alloc;
        int id;
 
-       spin_lock_bh(&net->nsid_lock);
+       spin_lock_irqsave(&net->nsid_lock, flags);
        alloc = atomic_read(&peer->count) == 0 ? false : true;
        id = __peernet2id_alloc(net, peer, &alloc);
-       spin_unlock_bh(&net->nsid_lock);
+       spin_unlock_irqrestore(&net->nsid_lock, flags);
        if (alloc && id >= 0)
                rtnl_net_notifyid(net, RTM_NEWNSID, id);
        return id;
@@ -230,11 +231,12 @@ int peernet2id_alloc(struct net *net, struct net *peer)
 /* This function returns, if assigned, the id of a peer netns. */
 int peernet2id(struct net *net, struct net *peer)
 {
+       unsigned long flags;
        int id;
 
-       spin_lock_bh(&net->nsid_lock);
+       spin_lock_irqsave(&net->nsid_lock, flags);
        id = __peernet2id(net, peer);
-       spin_unlock_bh(&net->nsid_lock);
+       spin_unlock_irqrestore(&net->nsid_lock, flags);
        return id;
 }
 EXPORT_SYMBOL(peernet2id);
@@ -249,17 +251,18 @@ bool peernet_has_id(struct net *net, struct net *peer)
 
 struct net *get_net_ns_by_id(struct net *net, int id)
 {
+       unsigned long flags;
        struct net *peer;
 
        if (id < 0)
                return NULL;
 
        rcu_read_lock();
-       spin_lock_bh(&net->nsid_lock);
+       spin_lock_irqsave(&net->nsid_lock, flags);
        peer = idr_find(&net->netns_ids, id);
        if (peer)
                get_net(peer);
-       spin_unlock_bh(&net->nsid_lock);
+       spin_unlock_irqrestore(&net->nsid_lock, flags);
        rcu_read_unlock();
 
        return peer;
@@ -309,6 +312,16 @@ out_undo:
 
 
 #ifdef CONFIG_NET_NS
+static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
+{
+       return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
+}
+
+static void dec_net_namespaces(struct ucounts *ucounts)
+{
+       dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
+}
+
 static struct kmem_cache *net_cachep;
 static struct workqueue_struct *netns_wq;
 
@@ -350,19 +363,27 @@ void net_drop_ns(void *p)
 struct net *copy_net_ns(unsigned long flags,
                        struct user_namespace *user_ns, struct net *old_net)
 {
+       struct ucounts *ucounts;
        struct net *net;
        int rv;
 
        if (!(flags & CLONE_NEWNET))
                return get_net(old_net);
 
+       ucounts = inc_net_namespaces(user_ns);
+       if (!ucounts)
+               return ERR_PTR(-ENOSPC);
+
        net = net_alloc();
-       if (!net)
+       if (!net) {
+               dec_net_namespaces(ucounts);
                return ERR_PTR(-ENOMEM);
+       }
 
        get_user_ns(user_ns);
 
        mutex_lock(&net_mutex);
+       net->ucounts = ucounts;
        rv = setup_net(net, user_ns);
        if (rv == 0) {
                rtnl_lock();
@@ -371,6 +392,7 @@ struct net *copy_net_ns(unsigned long flags,
        }
        mutex_unlock(&net_mutex);
        if (rv < 0) {
+               dec_net_namespaces(ucounts);
                put_user_ns(user_ns);
                net_drop_ns(net);
                return ERR_PTR(rv);
@@ -403,17 +425,17 @@ static void cleanup_net(struct work_struct *work)
                for_each_net(tmp) {
                        int id;
 
-                       spin_lock_bh(&tmp->nsid_lock);
+                       spin_lock_irq(&tmp->nsid_lock);
                        id = __peernet2id(tmp, net);
                        if (id >= 0)
                                idr_remove(&tmp->netns_ids, id);
-                       spin_unlock_bh(&tmp->nsid_lock);
+                       spin_unlock_irq(&tmp->nsid_lock);
                        if (id >= 0)
                                rtnl_net_notifyid(tmp, RTM_DELNSID, id);
                }
-               spin_lock_bh(&net->nsid_lock);
+               spin_lock_irq(&net->nsid_lock);
                idr_destroy(&net->netns_ids);
-               spin_unlock_bh(&net->nsid_lock);
+               spin_unlock_irq(&net->nsid_lock);
 
        }
        rtnl_unlock();
@@ -443,6 +465,7 @@ static void cleanup_net(struct work_struct *work)
        /* Finally it is safe to free my network namespace structure */
        list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
                list_del_init(&net->exit_list);
+               dec_net_namespaces(net->ucounts);
                put_user_ns(net->user_ns);
                net_drop_ns(net);
        }
@@ -541,6 +564,7 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
        struct net *net = sock_net(skb->sk);
        struct nlattr *tb[NETNSA_MAX + 1];
+       unsigned long flags;
        struct net *peer;
        int nsid, err;
 
@@ -561,15 +585,15 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
        if (IS_ERR(peer))
                return PTR_ERR(peer);
 
-       spin_lock_bh(&net->nsid_lock);
+       spin_lock_irqsave(&net->nsid_lock, flags);
        if (__peernet2id(net, peer) >= 0) {
-               spin_unlock_bh(&net->nsid_lock);
+               spin_unlock_irqrestore(&net->nsid_lock, flags);
                err = -EEXIST;
                goto out;
        }
 
        err = alloc_netid(net, peer, nsid);
-       spin_unlock_bh(&net->nsid_lock);
+       spin_unlock_irqrestore(&net->nsid_lock, flags);
        if (err >= 0) {
                rtnl_net_notifyid(net, RTM_NEWNSID, err);
                err = 0;
@@ -691,10 +715,11 @@ static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
                .idx = 0,
                .s_idx = cb->args[0],
        };
+       unsigned long flags;
 
-       spin_lock_bh(&net->nsid_lock);
+       spin_lock_irqsave(&net->nsid_lock, flags);
        idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
-       spin_unlock_bh(&net->nsid_lock);
+       spin_unlock_irqrestore(&net->nsid_lock, flags);
 
        cb->args[0] = net_cb.idx;
        return skb->len;
@@ -1004,11 +1029,17 @@ static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
        return 0;
 }
 
+static struct user_namespace *netns_owner(struct ns_common *ns)
+{
+       return to_net_ns(ns)->user_ns;
+}
+
 const struct proc_ns_operations netns_operations = {
        .name           = "net",
        .type           = CLONE_NEWNET,
        .get            = netns_get,
        .put            = netns_put,
        .install        = netns_install,
+       .owner          = netns_owner,
 };
 #endif