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-rw-r--r--net/core/net_namespace.c77
1 files changed, 23 insertions, 54 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 95ba2c53bd9a..b5796d17a302 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -40,12 +40,13 @@ struct net init_net = {
EXPORT_SYMBOL(init_net);
static bool init_net_initialized;
-static unsigned nr_sync_pernet_ops;
/*
- * net_sem: protects: pernet_list, net_generic_ids, nr_sync_pernet_ops,
+ * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
* init_net_initialized and first_device pointer.
+ * This is internal net namespace object. Please, don't use it
+ * outside.
*/
-DECLARE_RWSEM(net_sem);
+DECLARE_RWSEM(pernet_ops_rwsem);
#define MIN_PERNET_OPS_ID \
((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
@@ -73,7 +74,7 @@ static int net_assign_generic(struct net *net, unsigned int id, void *data)
BUG_ON(id < MIN_PERNET_OPS_ID);
old_ng = rcu_dereference_protected(net->gen,
- lockdep_is_held(&net_sem));
+ lockdep_is_held(&pernet_ops_rwsem));
if (old_ng->s.len > id) {
old_ng->ptr[id] = data;
return 0;
@@ -290,7 +291,7 @@ struct net *get_net_ns_by_id(struct net *net, int id)
*/
static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
{
- /* Must be called with net_sem held */
+ /* Must be called with pernet_ops_rwsem held */
const struct pernet_operations *ops, *saved_ops;
int error = 0;
LIST_HEAD(net_exit_list);
@@ -339,7 +340,6 @@ static int __net_init net_defaults_init_net(struct net *net)
static struct pernet_operations net_defaults_ops = {
.init = net_defaults_init_net,
- .async = true,
};
static __init int net_defaults_init(void)
@@ -406,7 +406,6 @@ struct net *copy_net_ns(unsigned long flags,
{
struct ucounts *ucounts;
struct net *net;
- unsigned write;
int rv;
if (!(flags & CLONE_NEWNET))
@@ -424,25 +423,14 @@ struct net *copy_net_ns(unsigned long flags,
refcount_set(&net->passive, 1);
net->ucounts = ucounts;
get_user_ns(user_ns);
-again:
- write = READ_ONCE(nr_sync_pernet_ops);
- if (write)
- rv = down_write_killable(&net_sem);
- else
- rv = down_read_killable(&net_sem);
+
+ rv = down_read_killable(&pernet_ops_rwsem);
if (rv < 0)
goto put_userns;
- if (!write && unlikely(READ_ONCE(nr_sync_pernet_ops))) {
- up_read(&net_sem);
- goto again;
- }
rv = setup_net(net, user_ns);
- if (write)
- up_write(&net_sem);
- else
- up_read(&net_sem);
+ up_read(&pernet_ops_rwsem);
if (rv < 0) {
put_userns:
@@ -490,21 +478,11 @@ static void cleanup_net(struct work_struct *work)
struct net *net, *tmp, *last;
struct llist_node *net_kill_list;
LIST_HEAD(net_exit_list);
- unsigned write;
/* Atomically snapshot the list of namespaces to cleanup */
net_kill_list = llist_del_all(&cleanup_list);
-again:
- write = READ_ONCE(nr_sync_pernet_ops);
- if (write)
- down_write(&net_sem);
- else
- down_read(&net_sem);
- if (!write && unlikely(READ_ONCE(nr_sync_pernet_ops))) {
- up_read(&net_sem);
- goto again;
- }
+ down_read(&pernet_ops_rwsem);
/* Don't let anyone else find us. */
rtnl_lock();
@@ -543,10 +521,7 @@ again:
list_for_each_entry_reverse(ops, &pernet_list, list)
ops_free_list(ops, &net_exit_list);
- if (write)
- up_write(&net_sem);
- else
- up_read(&net_sem);
+ up_read(&pernet_ops_rwsem);
/* Ensure there are no outstanding rcu callbacks using this
* network namespace.
@@ -573,8 +548,8 @@ again:
*/
void net_ns_barrier(void)
{
- down_write(&net_sem);
- up_write(&net_sem);
+ down_write(&pernet_ops_rwsem);
+ up_write(&pernet_ops_rwsem);
}
EXPORT_SYMBOL(net_ns_barrier);
@@ -654,7 +629,6 @@ static __net_exit void net_ns_net_exit(struct net *net)
static struct pernet_operations __net_initdata net_ns_ops = {
.init = net_ns_net_init,
.exit = net_ns_net_exit,
- .async = true,
};
static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
@@ -897,12 +871,12 @@ static int __init net_ns_init(void)
rcu_assign_pointer(init_net.gen, ng);
- down_write(&net_sem);
+ down_write(&pernet_ops_rwsem);
if (setup_net(&init_net, &init_user_ns))
panic("Could not setup the initial network namespace");
init_net_initialized = true;
- up_write(&net_sem);
+ up_write(&pernet_ops_rwsem);
register_pernet_subsys(&net_ns_ops);
@@ -1006,9 +980,6 @@ again:
rcu_barrier();
if (ops->id)
ida_remove(&net_generic_ids, *ops->id);
- } else if (!ops->async) {
- pr_info_once("Pernet operations %ps are sync.\n", ops);
- nr_sync_pernet_ops++;
}
return error;
@@ -1016,8 +987,6 @@ again:
static void unregister_pernet_operations(struct pernet_operations *ops)
{
- if (!ops->async)
- BUG_ON(nr_sync_pernet_ops-- == 0);
__unregister_pernet_operations(ops);
rcu_barrier();
if (ops->id)
@@ -1046,9 +1015,9 @@ static void unregister_pernet_operations(struct pernet_operations *ops)
int register_pernet_subsys(struct pernet_operations *ops)
{
int error;
- down_write(&net_sem);
+ down_write(&pernet_ops_rwsem);
error = register_pernet_operations(first_device, ops);
- up_write(&net_sem);
+ up_write(&pernet_ops_rwsem);
return error;
}
EXPORT_SYMBOL_GPL(register_pernet_subsys);
@@ -1064,9 +1033,9 @@ EXPORT_SYMBOL_GPL(register_pernet_subsys);
*/
void unregister_pernet_subsys(struct pernet_operations *ops)
{
- down_write(&net_sem);
+ down_write(&pernet_ops_rwsem);
unregister_pernet_operations(ops);
- up_write(&net_sem);
+ up_write(&pernet_ops_rwsem);
}
EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
@@ -1092,11 +1061,11 @@ EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
int register_pernet_device(struct pernet_operations *ops)
{
int error;
- down_write(&net_sem);
+ down_write(&pernet_ops_rwsem);
error = register_pernet_operations(&pernet_list, ops);
if (!error && (first_device == &pernet_list))
first_device = &ops->list;
- up_write(&net_sem);
+ up_write(&pernet_ops_rwsem);
return error;
}
EXPORT_SYMBOL_GPL(register_pernet_device);
@@ -1112,11 +1081,11 @@ EXPORT_SYMBOL_GPL(register_pernet_device);
*/
void unregister_pernet_device(struct pernet_operations *ops)
{
- down_write(&net_sem);
+ down_write(&pernet_ops_rwsem);
if (&ops->list == first_device)
first_device = first_device->next;
unregister_pernet_operations(ops);
- up_write(&net_sem);
+ up_write(&pernet_ops_rwsem);
}
EXPORT_SYMBOL_GPL(unregister_pernet_device);
generated by cgit v1.2.3 (git 2.46.0) at 2025-04-25 17:05:25 +0000