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authorDenis V. Lunev <den@openvz.org>2008-04-16 01:58:04 -0700
committerDavid S. Miller <davem@davemloft.net>2008-04-16 01:58:04 -0700
commit5d1e4468a7705db7c1415a65fd16f07113afc1b2 (patch)
tree41d34aa3f0e3b8cc0453973d8ce9e03303264080
parent554eb27782d4bb79e0a286a08ecafb81f758058c (diff)
[NETNS]: Make netns refconting debug like a socket one.
Make release_net/hold_net noop for performance-hungry people. This is a debug staff and should be used in the debug mode only. Add check for net != NULL in hold/release calls. This will be required later on. [ Added minor simplifications suggested by Brian Haley. -DaveM ] Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/net_namespace.h40
-rw-r--r--net/core/net_namespace.c4
2 files changed, 28 insertions, 16 deletions
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index f880b0f9f10..aa540e6be50 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -26,9 +26,11 @@ struct net {
atomic_t count; /* To decided when the network
* namespace should be freed.
*/
+#ifdef NETNS_REFCNT_DEBUG
atomic_t use_count; /* To track references we
* destroy on demand
*/
+#endif
struct list_head list; /* list of network namespaces */
struct work_struct work; /* work struct for freeing */
@@ -117,17 +119,6 @@ static inline void put_net(struct net *net)
__put_net(net);
}
-static inline struct net *hold_net(struct net *net)
-{
- atomic_inc(&net->use_count);
- return net;
-}
-
-static inline void release_net(struct net *net)
-{
- atomic_dec(&net->use_count);
-}
-
static inline
int net_eq(const struct net *net1, const struct net *net2)
{
@@ -143,27 +134,44 @@ static inline void put_net(struct net *net)
{
}
+static inline struct net *maybe_get_net(struct net *net)
+{
+ return net;
+}
+
+static inline
+int net_eq(const struct net *net1, const struct net *net2)
+{
+ return 1;
+}
+#endif
+
+
+#ifdef NETNS_REFCNT_DEBUG
static inline struct net *hold_net(struct net *net)
{
+ if (net)
+ atomic_inc(&net->use_count);
return net;
}
static inline void release_net(struct net *net)
{
+ if (net)
+ atomic_dec(&net->use_count);
}
-
-static inline struct net *maybe_get_net(struct net *net)
+#else
+static inline struct net *hold_net(struct net *net)
{
return net;
}
-static inline
-int net_eq(const struct net *net1, const struct net *net2)
+static inline void release_net(struct net *net)
{
- return 1;
}
#endif
+
#define for_each_net(VAR) \
list_for_each_entry(VAR, &net_namespace_list, list)
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 763674e1e59..72b4c184dd8 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -35,7 +35,9 @@ static __net_init int setup_net(struct net *net)
struct net_generic *ng;
atomic_set(&net->count, 1);
+#ifdef NETNS_REFCNT_DEBUG
atomic_set(&net->use_count, 0);
+#endif
error = -ENOMEM;
ng = kzalloc(sizeof(struct net_generic) +
@@ -86,11 +88,13 @@ static void net_free(struct net *net)
if (!net)
return;
+#ifdef NETNS_REFCNT_DEBUG
if (unlikely(atomic_read(&net->use_count) != 0)) {
printk(KERN_EMERG "network namespace not free! Usage: %d\n",
atomic_read(&net->use_count));
return;
}
+#endif
kmem_cache_free(net_cachep, net);
}