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linux-next/include/net/netns/generic.h
Paul Gortmaker 187f1882b5 BUG: headers with BUG/BUG_ON etc. need linux/bug.h
If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
other BUG variant in a static inline (i.e. not in a #define) then
that header really should be including <linux/bug.h> and not just
expecting it to be implicitly present.

We can make this change risk-free, since if the files using these
headers didn't have exposure to linux/bug.h already, they would have
been causing compile failures/warnings.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-03-04 17:54:34 -05:00

49 lines
1.1 KiB
C

/*
* generic net pointers
*/
#ifndef __NET_GENERIC_H__
#define __NET_GENERIC_H__
#include <linux/bug.h>
#include <linux/rcupdate.h>
/*
* Generic net pointers are to be used by modules to put some private
* stuff on the struct net without explicit struct net modification
*
* The rules are simple:
* 1. set pernet_operations->id. After register_pernet_device you
* will have the id of your private pointer.
* 2. set pernet_operations->size to have the code allocate and free
* a private structure pointed to from struct net.
* 3. do not change this pointer while the net is alive;
* 4. do not try to have any private reference on the net_generic object.
*
* After accomplishing all of the above, the private pointer can be
* accessed with the net_generic() call.
*/
struct net_generic {
unsigned int len;
struct rcu_head rcu;
void *ptr[0];
};
static inline void *net_generic(const struct net *net, int id)
{
struct net_generic *ng;
void *ptr;
rcu_read_lock();
ng = rcu_dereference(net->gen);
BUG_ON(id == 0 || id > ng->len);
ptr = ng->ptr[id - 1];
rcu_read_unlock();
BUG_ON(!ptr);
return ptr;
}
#endif