net_sem is some undefined area name, so it will be better
to make the area more defined.
Rename it to pernet_ops_rwsem for better readability and
better intelligibility.
Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com>
---
include/linux/rtnetlink.h | 2 +-
include/net/net_namespace.h | 12 +++++++-----
net/core/net_namespace.c | 40 ++++++++++++++++++++--------------------
net/core/rtnetlink.c | 4 ++--
4 files changed, 30 insertions(+), 28 deletions(-)
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 562a175c35a9..c7d1e4689325 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -36,7 +36,7 @@ extern int rtnl_is_locked(void);
extern int rtnl_lock_killable(void);
extern wait_queue_head_t netdev_unregistering_wq;
-extern struct rw_semaphore net_sem;
+extern struct rw_semaphore pernet_ops_rwsem;
#ifdef CONFIG_PROVE_LOCKING
extern bool lockdep_rtnl_is_held(void);
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 37bcf8382b61..922e8b6fb422 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -60,9 +60,10 @@ struct net {
struct list_head list; /* list of network namespaces */
struct list_head exit_list; /* To linked to call pernet exit
- * methods on dead net (net_sem
- * read locked), or to
unregister
- * pernet ops (net_sem wr
locked).
+ * methods on dead net (
+ * pernet_ops_rwsem read
locked),
+ * or to unregister pernet ops
+ * (pernet_ops_rwsem write
locked).
*/
struct llist_node cleanup_list; /* namespaces on death row */
@@ -95,8 +96,9 @@ struct net {
/* core fib_rules */
struct list_head rules_ops;
- struct list_head fib_notifier_ops; /* protected by net_sem */
-
+ struct list_head fib_notifier_ops; /* Populated by
+ * register_pernet_subsys()
+ */
struct net_device *loopback_dev; /* The loopback */
struct netns_core core;
struct netns_mib mib;
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index eef17ad29dea..9e8ee4640451 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -41,10 +41,10 @@ EXPORT_SYMBOL(init_net);
static bool init_net_initialized;
/*
- * net_sem: protects: pernet_list, net_generic_ids,
+ * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
* init_net_initialized and first_device pointer.
*/
-DECLARE_RWSEM(net_sem);
+DECLARE_RWSEM(pernet_ops_rwsem);
#define MIN_PERNET_OPS_ID \
((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
@@ -72,7 +72,7 @@ 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;
@@ -289,7 +289,7 @@ 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);
@@ -422,13 +422,13 @@ struct net *copy_net_ns(unsigned long flags,
net->ucounts = ucounts;
get_user_ns(user_ns);
- rv = down_read_killable(&net_sem);
+ rv = down_read_killable(&pernet_ops_rwsem);
if (rv < 0)
goto put_userns;
rv = setup_net(net, user_ns);
- up_read(&net_sem);
+ up_read(&pernet_ops_rwsem);
if (rv < 0) {
put_userns:
@@ -480,7 +480,7 @@ static void cleanup_net(struct work_struct *work)
/* Atomically snapshot the list of namespaces to cleanup */
net_kill_list = llist_del_all(&cleanup_list);
- down_read(&net_sem);
+ down_read(&pernet_ops_rwsem);
/* Don't let anyone else find us. */
rtnl_lock();
@@ -519,7 +519,7 @@ static void cleanup_net(struct work_struct *work)
list_for_each_entry_reverse(ops, &pernet_list, list)
ops_free_list(ops, &net_exit_list);
- up_read(&net_sem);
+ up_read(&pernet_ops_rwsem);
/* Ensure there are no outstanding rcu callbacks using this
* network namespace.
@@ -546,8 +546,8 @@ static void cleanup_net(struct work_struct *work)
*/
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);
@@ -869,12 +869,12 @@ 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);
@@ -1013,9 +1013,9 @@ 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);
@@ -1031,9 +1031,9 @@ 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);
@@ -1059,11 +1059,11 @@ 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);
@@ -1079,11 +1079,11 @@ 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);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 31438b63d4b4..73011a60434c 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -460,11 +460,11 @@ static void rtnl_lock_unregistering_all(void)
void rtnl_link_unregister(struct rtnl_link_ops *ops)
{
/* Close the race with cleanup_net() */
- down_write(&net_sem);
+ down_write(&pernet_ops_rwsem);
rtnl_lock_unregistering_all();
__rtnl_link_unregister(ops);
rtnl_unlock();
- up_write(&net_sem);
+ up_write(&pernet_ops_rwsem);
}
EXPORT_SYMBOL_GPL(rtnl_link_unregister);
