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Commit 5d1e4468 authored by Denis V. Lunev's avatar Denis V. Lunev Committed by David S. Miller
Browse files

[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: default avatarDenis V. Lunev <den@openvz.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 554eb277

include/net/net_namespace.h

+24 −16
Original line number Diff line number Diff line
@@ -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)

net/core/net_namespace.c

+4 −0
Original line number Diff line number Diff line
@@ -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);

}