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author | Russell King | 2008-04-19 18:17:34 +0200 |
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committer | Russell King | 2008-04-19 18:17:34 +0200 |
commit | cf816ecb533ab96b883dfdc0db174598b5b5c4d2 (patch) | |
tree | 1b7705db288ae2917105e624b01fdf81e0882bf1 /include/net/netns/generic.h | |
parent | Merge branch 'omap2-upstream' into devel (diff) | |
parent | [ARM] Remove leds-tosa.c (diff) | |
download | kernel-qcow2-linux-cf816ecb533ab96b883dfdc0db174598b5b5c4d2.tar.gz kernel-qcow2-linux-cf816ecb533ab96b883dfdc0db174598b5b5c4d2.tar.xz kernel-qcow2-linux-cf816ecb533ab96b883dfdc0db174598b5b5c4d2.zip |
Merge branch 'merge-fixes' into devel
Diffstat (limited to 'include/net/netns/generic.h')
-rw-r--r-- | include/net/netns/generic.h | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/include/net/netns/generic.h b/include/net/netns/generic.h new file mode 100644 index 000000000000..0c04fd2a700b --- /dev/null +++ b/include/net/netns/generic.h @@ -0,0 +1,49 @@ +/* + * generic net pointers + */ + +#ifndef __NET_GENERIC_H__ +#define __NET_GENERIC_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. register the ops with register_pernet_gen_device to get the id + * of your private pointer; + * 2. call net_assign_generic() to put the private data on the struct + * net (most preferably this should be done in the ->init callback + * of the ops registered); + * 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(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(); + + return ptr; +} + +extern int net_assign_generic(struct net *net, int id, void *data); +#endif |