net: Automatically allocate per namespace data.
To get the full benefit of batched network namespace cleanup netowrk
device deletion needs to be performed by the generic code. When
using register_pernet_gen_device and freeing the data in exit_net
it is impossible to delay allocation until after exit_net has called
as the device uninit methods are no longer safe.
To correct this, and to simplify working with per network namespace data
I have moved allocation and deletion of per network namespace data into
the network namespace core. The core now frees the data only after
all of the network namespace exit routines have run.
Now it is only required to set the new fields .id and .size
in the pernet_operations structure if you want network namespace
data to be managed for you automatically.
This makes the current register_pernet_gen_device and
register_pernet_gen_subsys routines unnecessary. For the moment
I have left them as compatibility wrappers in net_namespace.h
They will be removed once all of the users have been updated.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index a42caa2..9679ad2 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -43,13 +43,40 @@
}
}
+static int ops_init(const struct pernet_operations *ops, struct net *net)
+{
+ int err;
+ if (ops->id && ops->size) {
+ void *data = kzalloc(ops->size, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ err = net_assign_generic(net, *ops->id, data);
+ if (err) {
+ kfree(data);
+ return err;
+ }
+ }
+ if (ops->init)
+ return ops->init(net);
+ return 0;
+}
+
+static void ops_free(const struct pernet_operations *ops, struct net *net)
+{
+ if (ops->id && ops->size) {
+ int id = *ops->id;
+ kfree(net_generic(net, id));
+ }
+}
+
/*
* setup_net runs the initializers for the network namespace object.
*/
static __net_init int setup_net(struct net *net)
{
/* Must be called with net_mutex held */
- struct pernet_operations *ops;
+ const struct pernet_operations *ops, *saved_ops;
int error = 0;
atomic_set(&net->count, 1);
@@ -59,11 +86,9 @@
#endif
list_for_each_entry(ops, &pernet_list, list) {
- if (ops->init) {
- error = ops->init(net);
- if (error < 0)
- goto out_undo;
- }
+ error = ops_init(ops, net);
+ if (error < 0)
+ goto out_undo;
}
out:
return error;
@@ -72,6 +97,7 @@
/* Walk through the list backwards calling the exit functions
* for the pernet modules whose init functions did not fail.
*/
+ saved_ops = ops;
list_for_each_entry_continue_reverse(ops, &pernet_list, list) {
if (ops->exit)
ops->exit(net);
@@ -83,6 +109,9 @@
rtnl_unlock();
}
}
+ ops = saved_ops;
+ list_for_each_entry_continue_reverse(ops, &pernet_list, list)
+ ops_free(ops, net);
rcu_barrier();
goto out;
@@ -175,7 +204,7 @@
static void cleanup_net(struct work_struct *work)
{
- struct pernet_operations *ops;
+ const struct pernet_operations *ops;
struct net *net, *tmp;
LIST_HEAD(net_kill_list);
@@ -214,6 +243,13 @@
rtnl_unlock();
}
}
+ /* Free the net generic variables */
+ list_for_each_entry_reverse(ops, &pernet_list, list) {
+ if (ops->size && ops->id) {
+ list_for_each_entry(net, &net_kill_list, cleanup_list)
+ ops_free(ops, net);
+ }
+ }
mutex_unlock(&net_mutex);
@@ -309,16 +345,16 @@
pure_initcall(net_ns_init);
#ifdef CONFIG_NET_NS
-static int register_pernet_operations(struct list_head *list,
- struct pernet_operations *ops)
+static int __register_pernet_operations(struct list_head *list,
+ struct pernet_operations *ops)
{
struct net *net, *undo_net;
int error;
list_add_tail(&ops->list, list);
- if (ops->init) {
+ if (ops->init || (ops->id && ops->size)) {
for_each_net(net) {
- error = ops->init(net);
+ error = ops_init(ops, net);
if (error)
goto out_undo;
}
@@ -336,10 +372,18 @@
}
}
undone:
+ if (ops->size && ops->id) {
+ for_each_net(undo_net) {
+ if (net_eq(undo_net, net))
+ goto freed;
+ ops_free(ops, undo_net);
+ }
+ }
+freed:
return error;
}
-static void unregister_pernet_operations(struct pernet_operations *ops)
+static void __unregister_pernet_operations(struct pernet_operations *ops)
{
struct net *net;
@@ -347,26 +391,65 @@
if (ops->exit)
for_each_net(net)
ops->exit(net);
+ if (ops->id && ops->size)
+ for_each_net(net)
+ ops_free(ops, net);
}
#else
+static int __register_pernet_operations(struct list_head *list,
+ struct pernet_operations *ops)
+{
+ int err = 0;
+ err = ops_init(ops, &init_net);
+ if (err)
+ ops_free(ops, &init_net);
+ return err;
+
+}
+
+static void __unregister_pernet_operations(struct pernet_operations *ops)
+{
+ if (ops->exit)
+ ops->exit(&init_net);
+ ops_free(ops, &init_net);
+}
+
+#endif /* CONFIG_NET_NS */
+
+static DEFINE_IDA(net_generic_ids);
+
static int register_pernet_operations(struct list_head *list,
struct pernet_operations *ops)
{
- if (ops->init == NULL)
- return 0;
- return ops->init(&init_net);
+ int error;
+
+ if (ops->id) {
+again:
+ error = ida_get_new_above(&net_generic_ids, 1, ops->id);
+ if (error < 0) {
+ if (error == -EAGAIN) {
+ ida_pre_get(&net_generic_ids, GFP_KERNEL);
+ goto again;
+ }
+ return error;
+ }
+ }
+ error = __register_pernet_operations(list, ops);
+ if (error && ops->id)
+ ida_remove(&net_generic_ids, *ops->id);
+
+ return error;
}
static void unregister_pernet_operations(struct pernet_operations *ops)
{
- if (ops->exit)
- ops->exit(&init_net);
+
+ __unregister_pernet_operations(ops);
+ if (ops->id)
+ ida_remove(&net_generic_ids, *ops->id);
}
-#endif
-
-static DEFINE_IDA(net_generic_ids);
/**
* register_pernet_subsys - register a network namespace subsystem
@@ -414,38 +497,6 @@
}
EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
-int register_pernet_gen_subsys(int *id, struct pernet_operations *ops)
-{
- int rv;
-
- mutex_lock(&net_mutex);
-again:
- rv = ida_get_new_above(&net_generic_ids, 1, id);
- if (rv < 0) {
- if (rv == -EAGAIN) {
- ida_pre_get(&net_generic_ids, GFP_KERNEL);
- goto again;
- }
- goto out;
- }
- rv = register_pernet_operations(first_device, ops);
- if (rv < 0)
- ida_remove(&net_generic_ids, *id);
-out:
- mutex_unlock(&net_mutex);
- return rv;
-}
-EXPORT_SYMBOL_GPL(register_pernet_gen_subsys);
-
-void unregister_pernet_gen_subsys(int id, struct pernet_operations *ops)
-{
- mutex_lock(&net_mutex);
- unregister_pernet_operations(ops);
- ida_remove(&net_generic_ids, id);
- mutex_unlock(&net_mutex);
-}
-EXPORT_SYMBOL_GPL(unregister_pernet_gen_subsys);
-
/**
* register_pernet_device - register a network namespace device
* @ops: pernet operations structure for the subsystem
@@ -477,30 +528,6 @@
}
EXPORT_SYMBOL_GPL(register_pernet_device);
-int register_pernet_gen_device(int *id, struct pernet_operations *ops)
-{
- int error;
- mutex_lock(&net_mutex);
-again:
- error = ida_get_new_above(&net_generic_ids, 1, id);
- if (error) {
- if (error == -EAGAIN) {
- ida_pre_get(&net_generic_ids, GFP_KERNEL);
- goto again;
- }
- goto out;
- }
- error = register_pernet_operations(&pernet_list, ops);
- if (error)
- ida_remove(&net_generic_ids, *id);
- else if (first_device == &pernet_list)
- first_device = &ops->list;
-out:
- mutex_unlock(&net_mutex);
- return error;
-}
-EXPORT_SYMBOL_GPL(register_pernet_gen_device);
-
/**
* unregister_pernet_device - unregister a network namespace netdevice
* @ops: pernet operations structure to manipulate
@@ -520,17 +547,6 @@
}
EXPORT_SYMBOL_GPL(unregister_pernet_device);
-void unregister_pernet_gen_device(int id, struct pernet_operations *ops)
-{
- mutex_lock(&net_mutex);
- if (&ops->list == first_device)
- first_device = first_device->next;
- unregister_pernet_operations(ops);
- ida_remove(&net_generic_ids, id);
- mutex_unlock(&net_mutex);
-}
-EXPORT_SYMBOL_GPL(unregister_pernet_gen_device);
-
static void net_generic_release(struct rcu_head *rcu)
{
struct net_generic *ng;