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authorAl Viro <viro@zeniv.linux.org.uk>2011-06-08 21:13:01 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2011-06-12 17:45:41 -0400
commita685e08987d1edf1995b76511d4c98ea0e905377 (patch)
tree1d42593e2bc320f8d93b98851b2df0fd432e3859 /include/net
parentdde194a64bb5c3fd05d965775dc92e8a4920a53a (diff)
Delay struct net freeing while there's a sysfs instance refering to it
* new refcount in struct net, controlling actual freeing of the memory * new method in kobj_ns_type_operations (->drop_ns()) * ->current_ns() semantics change - it's supposed to be followed by corresponding ->drop_ns(). For struct net in case of CONFIG_NET_NS it bumps the new refcount; net_drop_ns() decrements it and calls net_free() if the last reference has been dropped. Method renamed to ->grab_current_ns(). * old net_free() callers call net_drop_ns() instead. * sysfs_exit_ns() is gone, along with a large part of callchain leading to it; now that the references stored in ->ns[...] stay valid we do not need to hunt them down and replace them with NULL. That fixes problems in sysfs_lookup() and sysfs_readdir(), along with getting rid of sb->s_instances abuse. Note that struct net *shutdown* logics has not changed - net_cleanup() is called exactly when it used to be called. The only thing postponed by having a sysfs instance refering to that struct net is actual freeing of memory occupied by struct net. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/net')
-rw-r--r--include/net/net_namespace.h10
1 files changed, 9 insertions, 1 deletions
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 2bf9ed9ef26b..aef430d779bd 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -35,8 +35,11 @@ struct netns_ipvs;
#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
struct net {
+ atomic_t passive; /* To decided when the network
+ * namespace should be freed.
+ */
atomic_t count; /* To decided when the network
- * namespace should be freed.
+ * namespace should be shut down.
*/
#ifdef NETNS_REFCNT_DEBUG
atomic_t use_count; /* To track references we
@@ -154,6 +157,9 @@ int net_eq(const struct net *net1, const struct net *net2)
{
return net1 == net2;
}
+
+extern void net_drop_ns(void *);
+
#else
static inline struct net *get_net(struct net *net)
@@ -175,6 +181,8 @@ int net_eq(const struct net *net1, const struct net *net2)
{
return 1;
}
+
+#define net_drop_ns NULL
#endif