Revert "net: net_namespace: Optimize the code"
This reverts commit 37fdbeb0e293747f53eb4c575b3bcf525b76968e which is
commit 41467d2ff4dfe1837cbb0f45e2088e6e787580c6 upstream.
It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.
Bug: 161946584
Change-Id: If449b818cb2b6a551d723ab75281f449e3ea78b7
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 505a727..b950a5f 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -101,7 +101,7 @@ static int net_assign_generic(struct net *net, unsigned int id, void *data)
}
ng = net_alloc_generic();
- if (!ng)
+ if (ng == NULL)
return -ENOMEM;
/*
@@ -158,6 +158,13 @@ static int ops_init(const struct pernet_operations *ops, struct net *net)
return err;
}
+static void ops_free(const struct pernet_operations *ops, struct net *net)
+{
+ if (ops->id && ops->size) {
+ kfree(net_generic(net, *ops->id));
+ }
+}
+
static void ops_pre_exit_list(const struct pernet_operations *ops,
struct list_head *net_exit_list)
{
@@ -189,7 +196,7 @@ static void ops_free_list(const struct pernet_operations *ops,
struct net *net;
if (ops->size && ops->id) {
list_for_each_entry(net, net_exit_list, exit_list)
- kfree(net_generic(net, *ops->id));
+ ops_free(ops, net);
}
}
@@ -438,18 +445,15 @@ static struct net *net_alloc(void)
static void net_free(struct net *net)
{
- if (refcount_dec_and_test(&net->passive)) {
- kfree(rcu_access_pointer(net->gen));
- kmem_cache_free(net_cachep, net);
- }
+ kfree(rcu_access_pointer(net->gen));
+ kmem_cache_free(net_cachep, net);
}
void net_drop_ns(void *p)
{
- struct net *net = (struct net *)p;
-
- if (net)
- net_free(net);
+ struct net *ns = p;
+ if (ns && refcount_dec_and_test(&ns->passive))
+ net_free(ns);
}
struct net *copy_net_ns(unsigned long flags,
@@ -489,7 +493,7 @@ struct net *copy_net_ns(unsigned long flags,
key_remove_domain(net->key_domain);
#endif
put_user_ns(user_ns);
- net_free(net);
+ net_drop_ns(net);
dec_ucounts:
dec_net_namespaces(ucounts);
return ERR_PTR(rv);
@@ -623,7 +627,7 @@ static void cleanup_net(struct work_struct *work)
key_remove_domain(net->key_domain);
#endif
put_user_ns(net->user_ns);
- net_free(net);
+ net_drop_ns(net);
}
}
@@ -1143,14 +1147,6 @@ static int __init net_ns_init(void)
pure_initcall(net_ns_init);
-static void free_exit_list(struct pernet_operations *ops, struct list_head *net_exit_list)
-{
- ops_pre_exit_list(ops, net_exit_list);
- synchronize_rcu();
- ops_exit_list(ops, net_exit_list);
- ops_free_list(ops, net_exit_list);
-}
-
#ifdef CONFIG_NET_NS
static int __register_pernet_operations(struct list_head *list,
struct pernet_operations *ops)
@@ -1176,7 +1172,10 @@ static int __register_pernet_operations(struct list_head *list,
out_undo:
/* If I have an error cleanup all namespaces I initialized */
list_del(&ops->list);
- free_exit_list(ops, &net_exit_list);
+ ops_pre_exit_list(ops, &net_exit_list);
+ synchronize_rcu();
+ ops_exit_list(ops, &net_exit_list);
+ ops_free_list(ops, &net_exit_list);
return error;
}
@@ -1189,8 +1188,10 @@ static void __unregister_pernet_operations(struct pernet_operations *ops)
/* See comment in __register_pernet_operations() */
for_each_net(net)
list_add_tail(&net->exit_list, &net_exit_list);
-
- free_exit_list(ops, &net_exit_list);
+ ops_pre_exit_list(ops, &net_exit_list);
+ synchronize_rcu();
+ ops_exit_list(ops, &net_exit_list);
+ ops_free_list(ops, &net_exit_list);
}
#else
@@ -1213,7 +1214,10 @@ static void __unregister_pernet_operations(struct pernet_operations *ops)
} else {
LIST_HEAD(net_exit_list);
list_add(&init_net.exit_list, &net_exit_list);
- free_exit_list(ops, &net_exit_list);
+ ops_pre_exit_list(ops, &net_exit_list);
+ synchronize_rcu();
+ ops_exit_list(ops, &net_exit_list);
+ ops_free_list(ops, &net_exit_list);
}
}
