net: Add support for batching network namespace cleanups
- Add exit_list to struct net to support building lists of network
namespaces to cleanup.
- Add exit_batch to pernet_operations to allow running operations only
once during a network namespace exit. Instead of once per network
namespace.
- Factor opt ops_exit_list and ops_exit_free so the logic with cleanup
up a network namespace does not need to be duplicated.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 24a8c55..f307e13 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -43,6 +43,7 @@
#endif
struct list_head list; /* list of network namespaces */
struct list_head cleanup_list; /* namespaces on death row */
+ struct list_head exit_list; /* Use only net_mutex */
struct proc_dir_entry *proc_net;
struct proc_dir_entry *proc_net_stat;
@@ -236,6 +237,7 @@
struct list_head list;
int (*init)(struct net *net);
void (*exit)(struct net *net);
+ void (*exit_batch)(struct list_head *net_exit_list);
int *id;
size_t size;
};
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 9679ad2..6c7f6e0 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -70,6 +70,36 @@
}
}
+static void ops_exit_list(const struct pernet_operations *ops,
+ struct list_head *net_exit_list)
+{
+ struct net *net;
+ if (ops->exit) {
+ list_for_each_entry(net, net_exit_list, exit_list)
+ ops->exit(net);
+ }
+ if (&ops->list == first_device) {
+ LIST_HEAD(dev_kill_list);
+ rtnl_lock();
+ list_for_each_entry(net, net_exit_list, exit_list)
+ unregister_netdevices(net, &dev_kill_list);
+ unregister_netdevice_many(&dev_kill_list);
+ rtnl_unlock();
+ }
+ if (ops->exit_batch)
+ ops->exit_batch(net_exit_list);
+}
+
+static void ops_free_list(const struct pernet_operations *ops,
+ struct list_head *net_exit_list)
+{
+ struct net *net;
+ if (ops->size && ops->id) {
+ list_for_each_entry(net, net_exit_list, exit_list)
+ ops_free(ops, net);
+ }
+}
+
/*
* setup_net runs the initializers for the network namespace object.
*/
@@ -78,6 +108,7 @@
/* Must be called with net_mutex held */
const struct pernet_operations *ops, *saved_ops;
int error = 0;
+ LIST_HEAD(net_exit_list);
atomic_set(&net->count, 1);
@@ -97,21 +128,14 @@
/* Walk through the list backwards calling the exit functions
* for the pernet modules whose init functions did not fail.
*/
+ list_add(&net->exit_list, &net_exit_list);
saved_ops = ops;
- list_for_each_entry_continue_reverse(ops, &pernet_list, list) {
- if (ops->exit)
- ops->exit(net);
- if (&ops->list == first_device) {
- LIST_HEAD(dev_kill_list);
- rtnl_lock();
- unregister_netdevices(net, &dev_kill_list);
- unregister_netdevice_many(&dev_kill_list);
- rtnl_unlock();
- }
- }
+ list_for_each_entry_continue_reverse(ops, &pernet_list, list)
+ ops_exit_list(ops, &net_exit_list);
+
ops = saved_ops;
list_for_each_entry_continue_reverse(ops, &pernet_list, list)
- ops_free(ops, net);
+ ops_free_list(ops, &net_exit_list);
rcu_barrier();
goto out;
@@ -207,6 +231,7 @@
const struct pernet_operations *ops;
struct net *net, *tmp;
LIST_HEAD(net_kill_list);
+ LIST_HEAD(net_exit_list);
/* Atomically snapshot the list of namespaces to cleanup */
spin_lock_irq(&cleanup_list_lock);
@@ -217,8 +242,10 @@
/* Don't let anyone else find us. */
rtnl_lock();
- list_for_each_entry(net, &net_kill_list, cleanup_list)
+ list_for_each_entry(net, &net_kill_list, cleanup_list) {
list_del_rcu(&net->list);
+ list_add_tail(&net->exit_list, &net_exit_list);
+ }
rtnl_unlock();
/*
@@ -229,27 +256,12 @@
synchronize_rcu();
/* Run all of the network namespace exit methods */
- list_for_each_entry_reverse(ops, &pernet_list, list) {
- if (ops->exit) {
- list_for_each_entry(net, &net_kill_list, cleanup_list)
- ops->exit(net);
- }
- if (&ops->list == first_device) {
- LIST_HEAD(dev_kill_list);
- rtnl_lock();
- list_for_each_entry(net, &net_kill_list, cleanup_list)
- unregister_netdevices(net, &dev_kill_list);
- unregister_netdevice_many(&dev_kill_list);
- rtnl_unlock();
- }
- }
+ list_for_each_entry_reverse(ops, &pernet_list, list)
+ ops_exit_list(ops, &net_exit_list);
+
/* 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);
- }
- }
+ list_for_each_entry_reverse(ops, &pernet_list, list)
+ ops_free_list(ops, &net_exit_list);
mutex_unlock(&net_mutex);
@@ -259,8 +271,8 @@
rcu_barrier();
/* Finally it is safe to free my network namespace structure */
- list_for_each_entry_safe(net, tmp, &net_kill_list, cleanup_list) {
- list_del_init(&net->cleanup_list);
+ list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
+ list_del_init(&net->exit_list);
net_free(net);
}
}
@@ -348,8 +360,9 @@
static int __register_pernet_operations(struct list_head *list,
struct pernet_operations *ops)
{
- struct net *net, *undo_net;
+ struct net *net;
int error;
+ LIST_HEAD(net_exit_list);
list_add_tail(&ops->list, list);
if (ops->init || (ops->id && ops->size)) {
@@ -357,6 +370,7 @@
error = ops_init(ops, net);
if (error)
goto out_undo;
+ list_add_tail(&net->exit_list, &net_exit_list);
}
}
return 0;
@@ -364,36 +378,21 @@
out_undo:
/* If I have an error cleanup all namespaces I initialized */
list_del(&ops->list);
- if (ops->exit) {
- for_each_net(undo_net) {
- if (net_eq(undo_net, net))
- goto undone;
- ops->exit(undo_net);
- }
- }
-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:
+ ops_exit_list(ops, &net_exit_list);
+ ops_free_list(ops, &net_exit_list);
return error;
}
static void __unregister_pernet_operations(struct pernet_operations *ops)
{
struct net *net;
+ LIST_HEAD(net_exit_list);
list_del(&ops->list);
- if (ops->exit)
- for_each_net(net)
- ops->exit(net);
- if (ops->id && ops->size)
- for_each_net(net)
- ops_free(ops, net);
+ for_each_net(net)
+ list_add_tail(&net->exit_list, &net_exit_list);
+ ops_exit_list(ops, &net_exit_list);
+ ops_free_list(ops, &net_exit_list);
}
#else
@@ -411,9 +410,10 @@
static void __unregister_pernet_operations(struct pernet_operations *ops)
{
- if (ops->exit)
- ops->exit(&init_net);
- ops_free(ops, &init_net);
+ LIST_HEAD(net_exit_list);
+ list_add(&init_net.exit_list, &net_exit_list);
+ ops_exit_list(ops, &net_exit_list);
+ ops_free_list(ops, &net_exit_list);
}
#endif /* CONFIG_NET_NS */