root/include/linux/ipc_namespace.h

INCLUDED FROM

DEFINITIONS

1. get_ipc_ns
2. put_ipc_ns
3. copy_ipcs
4. get_ipc_ns
5. put_ipc_ns

#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;
        int             auto_msgmni;

        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 void 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