kernel-ark/include/linux/ipc_namespace.h
Nadia Derbey 6546bc4279 ipc: re-enable msgmni automatic recomputing msgmni if set to negative
The enhancement as asked for by Yasunori: if msgmni is set to a negative
value, register it back into the ipcns notifier chain.

A new interface has been added to the notification mechanism:
notifier_chain_cond_register() registers a notifier block only if not already
registered.  With that new interface we avoid taking care of the states
changes in procfs.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Pierre Peiffer <pierre.peiffer@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:13 -07:00

102 lines
2.2 KiB
C

#ifndef __IPC_NAMESPACE_H__
#define __IPC_NAMESPACE_H__
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/rwsem.h>
#include <linux/notifier.h>
/*
* ipc namespace events
*/
#define IPCNS_MEMCHANGED 0x00000001 /* Notify lowmem size changed */
#define IPCNS_CREATED 0x00000002 /* Notify new ipc namespace created */
#define IPCNS_REMOVED 0x00000003 /* Notify ipc namespace removed */
#define IPCNS_CALLBACK_PRI 0
struct ipc_ids {
int in_use;
unsigned short seq;
unsigned short seq_max;
struct rw_semaphore rw_mutex;
struct idr ipcs_idr;
};
struct ipc_namespace {
struct kref kref;
struct ipc_ids ids[3];
int sem_ctls[4];
int used_sems;
int msg_ctlmax;
int msg_ctlmnb;
int msg_ctlmni;
atomic_t msg_bytes;
atomic_t msg_hdrs;
size_t shm_ctlmax;
size_t shm_ctlall;
int shm_ctlmni;
int shm_tot;
struct notifier_block ipcns_nb;
};
extern struct ipc_namespace init_ipc_ns;
extern atomic_t nr_ipc_ns;
#ifdef CONFIG_SYSVIPC
#define INIT_IPC_NS(ns) .ns = &init_ipc_ns,
extern int register_ipcns_notifier(struct ipc_namespace *);
extern int cond_register_ipcns_notifier(struct ipc_namespace *);
extern int unregister_ipcns_notifier(struct ipc_namespace *);
extern int ipcns_notify(unsigned long);
#else /* CONFIG_SYSVIPC */
#define INIT_IPC_NS(ns)
#endif /* CONFIG_SYSVIPC */
#if defined(CONFIG_SYSVIPC) && defined(CONFIG_IPC_NS)
extern void free_ipc_ns(struct kref *kref);
extern struct ipc_namespace *copy_ipcs(unsigned long flags,
struct ipc_namespace *ns);
extern void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
void (*free)(struct ipc_namespace *,
struct kern_ipc_perm *));
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
{
if (ns)
kref_get(&ns->kref);
return ns;
}
static inline void put_ipc_ns(struct ipc_namespace *ns)
{
kref_put(&ns->kref, free_ipc_ns);
}
#else
static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
struct ipc_namespace *ns)
{
if (flags & CLONE_NEWIPC)
return ERR_PTR(-EINVAL);
return ns;
}
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
{
return ns;
}
static inline void put_ipc_ns(struct ipc_namespace *ns)
{
}
#endif
#endif