Merge branch 'next' into for-linus

1 files changed, 78 insertions, 19 deletions

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 3f860261c5ee..ea489db1bc23 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -8,6 +8,8 @@
 #include <linux/idr.h>
 #include <linux/rculist.h>
 #include <linux/nsproxy.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
@@ -27,14 +29,6 @@ EXPORT_SYMBOL(init_net);
 
 #define INITIAL_NET_GEN_PTRS    13 /* +1 for len +2 for rcu_head */
 
-static void net_generic_release(struct rcu_head *rcu)
-{
-        struct net_generic *ng;
-
-        ng = container_of(rcu, struct net_generic, rcu);
-        kfree(ng);
-}
-
 static int net_assign_generic(struct net *net, int id, void *data)
 {
         struct net_generic *ng, *old_ng;
@@ -68,7 +62,7 @@ static int net_assign_generic(struct net *net, int id, void *data)
         memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*));
 
         rcu_assign_pointer(net->gen, ng);
-        call_rcu(&old_ng->rcu, net_generic_release);
+        kfree_rcu(old_ng, rcu);
 assign:
         ng->ptr[id - 1] = data;
         return 0;
@@ -134,6 +128,7 @@ static __net_init int setup_net(struct net *net)
         LIST_HEAD(net_exit_list);
 
         atomic_set(&net->count, 1);
+        atomic_set(&net->passive, 1);
 
 #ifdef NETNS_REFCNT_DEBUG
         atomic_set(&net->use_count, 0);
@@ -216,11 +211,21 @@ static void net_free(struct net *net)
         kmem_cache_free(net_cachep, net);
 }
 
-static struct net *net_create(void)
+void net_drop_ns(void *p)
+{
+        struct net *ns = p;
+        if (ns && atomic_dec_and_test(&ns->passive))
+                net_free(ns);
+}
+
+struct net *copy_net_ns(unsigned long flags, struct net *old_net)
 {
         struct net *net;
         int rv;
 
+        if (!(flags & CLONE_NEWNET))
+                return get_net(old_net);
+
         net = net_alloc();
         if (!net)
                 return ERR_PTR(-ENOMEM);
@@ -233,19 +238,12 @@ static struct net *net_create(void)
         }
         mutex_unlock(&net_mutex);
         if (rv < 0) {
-                net_free(net);
+                net_drop_ns(net);
                 return ERR_PTR(rv);
         }
         return net;
 }
 
-struct net *copy_net_ns(unsigned long flags, struct net *old_net)
-{
-        if (!(flags & CLONE_NEWNET))
-                return get_net(old_net);
-        return net_create();
-}
-
 static DEFINE_SPINLOCK(cleanup_list_lock);
 static LIST_HEAD(cleanup_list);  /* Must hold cleanup_list_lock to touch */
 
@@ -296,7 +294,7 @@ 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);
-                net_free(net);
+                net_drop_ns(net);
         }
 }
 static DECLARE_WORK(net_cleanup_work, cleanup_net);
@@ -314,6 +312,26 @@ void __put_net(struct net *net)
 }
 EXPORT_SYMBOL_GPL(__put_net);
 
+struct net *get_net_ns_by_fd(int fd)
+{
+        struct proc_inode *ei;
+        struct file *file;
+        struct net *net;
+
+        file = proc_ns_fget(fd);
+        if (IS_ERR(file))
+                return ERR_CAST(file);
+
+        ei = PROC_I(file->f_dentry->d_inode);
+        if (ei->ns_ops == &netns_operations)
+                net = get_net(ei->ns);
+        else
+                net = ERR_PTR(-EINVAL);
+
+        fput(file);
+        return net;
+}
+
 #else
 struct net *copy_net_ns(unsigned long flags, struct net *old_net)
 {
@@ -321,6 +339,11 @@ struct net *copy_net_ns(unsigned long flags, struct net *old_net)
                 return ERR_PTR(-EINVAL);
         return old_net;
 }
+
+struct net *get_net_ns_by_fd(int fd)
+{
+        return ERR_PTR(-EINVAL);
+}
 #endif
 
 struct net *get_net_ns_by_pid(pid_t pid)
@@ -573,3 +596,39 @@ void unregister_pernet_device(struct pernet_operations *ops)
         mutex_unlock(&net_mutex);
 }
 EXPORT_SYMBOL_GPL(unregister_pernet_device);
+
+#ifdef CONFIG_NET_NS
+static void *netns_get(struct task_struct *task)
+{
+        struct net *net = NULL;
+        struct nsproxy *nsproxy;
+
+        rcu_read_lock();
+        nsproxy = task_nsproxy(task);
+        if (nsproxy)
+                net = get_net(nsproxy->net_ns);
+        rcu_read_unlock();
+
+        return net;
+}
+
+static void netns_put(void *ns)
+{
+        put_net(ns);
+}
+
+static int netns_install(struct nsproxy *nsproxy, void *ns)
+{
+        put_net(nsproxy->net_ns);
+        nsproxy->net_ns = get_net(ns);
+        return 0;
+}
+
+const struct proc_ns_operations netns_operations = {
+        .name           = "net",
+        .type           = CLONE_NEWNET,
+        .get            = netns_get,
+        .put            = netns_put,
+        .install        = netns_install,
+};
+#endif