From 6a1a3b9f686bb04820a232cc1657ef2c45670709 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Thu, 1 Nov 2007 00:44:50 -0700 Subject: [PATCH] [NET]: Hide the dead code in the net_namespace.c The namespace creation/destruction code is never called if the CONFIG_NET_NS is n, so it's OK to move it under appropriate ifdef. The copy_net_ns() in the "n" case checks for flags and returns -EINVAL when new net ns is requested. In a perfect world this stub must be in net_namespace.h, but this function need to know the CLONE_NEWNET value and thus requires sched.h. On the other hand this header is to be injected into almost every .c file in the networking code, and making all this code depend on the sched.h is a suicidal attempt. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller --- net/core/net_namespace.c | 131 ++++++++++++++++++++------------------- 1 file changed, 68 insertions(+), 63 deletions(-) diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 4e52921ade0..d5bf8b28bbf 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -22,65 +22,6 @@ static struct kmem_cache *net_cachep; struct net init_net; EXPORT_SYMBOL_GPL(init_net); -static struct net *net_alloc(void) -{ - return kmem_cache_zalloc(net_cachep, GFP_KERNEL); -} - -static void net_free(struct net *net) -{ - if (!net) - return; - - if (unlikely(atomic_read(&net->use_count) != 0)) { - printk(KERN_EMERG "network namespace not free! Usage: %d\n", - atomic_read(&net->use_count)); - return; - } - - kmem_cache_free(net_cachep, net); -} - -static void cleanup_net(struct work_struct *work) -{ - struct pernet_operations *ops; - struct net *net; - - net = container_of(work, struct net, work); - - mutex_lock(&net_mutex); - - /* Don't let anyone else find us. */ - rtnl_lock(); - list_del(&net->list); - rtnl_unlock(); - - /* Run all of the network namespace exit methods */ - list_for_each_entry_reverse(ops, &pernet_list, list) { - if (ops->exit) - ops->exit(net); - } - - mutex_unlock(&net_mutex); - - /* Ensure there are no outstanding rcu callbacks using this - * network namespace. - */ - rcu_barrier(); - - /* Finally it is safe to free my network namespace structure */ - net_free(net); -} - - -void __put_net(struct net *net) -{ - /* Cleanup the network namespace in process context */ - INIT_WORK(&net->work, cleanup_net); - schedule_work(&net->work); -} -EXPORT_SYMBOL_GPL(__put_net); - /* * setup_net runs the initializers for the network namespace object. */ @@ -117,6 +58,12 @@ out_undo: goto out; } +#ifdef CONFIG_NET_NS +static struct net *net_alloc(void) +{ + return kmem_cache_zalloc(net_cachep, GFP_KERNEL); +} + struct net *copy_net_ns(unsigned long flags, struct net *old_net) { struct net *new_net = NULL; @@ -127,10 +74,6 @@ struct net *copy_net_ns(unsigned long flags, struct net *old_net) if (!(flags & CLONE_NEWNET)) return old_net; -#ifndef CONFIG_NET_NS - return ERR_PTR(-EINVAL); -#endif - err = -ENOMEM; new_net = net_alloc(); if (!new_net) @@ -157,6 +100,68 @@ out: return new_net; } +static void net_free(struct net *net) +{ + if (!net) + return; + + if (unlikely(atomic_read(&net->use_count) != 0)) { + printk(KERN_EMERG "network namespace not free! Usage: %d\n", + atomic_read(&net->use_count)); + return; + } + + kmem_cache_free(net_cachep, net); +} + +static void cleanup_net(struct work_struct *work) +{ + struct pernet_operations *ops; + struct net *net; + + net = container_of(work, struct net, work); + + mutex_lock(&net_mutex); + + /* Don't let anyone else find us. */ + rtnl_lock(); + list_del(&net->list); + rtnl_unlock(); + + /* Run all of the network namespace exit methods */ + list_for_each_entry_reverse(ops, &pernet_list, list) { + if (ops->exit) + ops->exit(net); + } + + mutex_unlock(&net_mutex); + + /* Ensure there are no outstanding rcu callbacks using this + * network namespace. + */ + rcu_barrier(); + + /* Finally it is safe to free my network namespace structure */ + net_free(net); +} + +void __put_net(struct net *net) +{ + /* Cleanup the network namespace in process context */ + INIT_WORK(&net->work, cleanup_net); + schedule_work(&net->work); +} +EXPORT_SYMBOL_GPL(__put_net); + +#else +struct net *copy_net_ns(unsigned long flags, struct net *old_net) +{ + if (flags & CLONE_NEWNET) + return ERR_PTR(-EINVAL); + return old_net; +} +#endif + static int __init net_ns_init(void) { int err; -- 2.41.1