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Serge E. Hallynab516012006-10-02 02:18:06 -07001#ifndef _LINUX_NSPROXY_H
2#define _LINUX_NSPROXY_H
3
4#include <linux/spinlock.h>
5#include <linux/sched.h>
6
Kirill Korotaev6b3286e2006-12-08 02:37:56 -08007struct mnt_namespace;
Serge E. Hallyn4865ecf2006-10-02 02:18:14 -07008struct uts_namespace;
Kirill Korotaev25b21cb2006-10-02 02:18:19 -07009struct ipc_namespace;
Cedric Le Goater9a575a92006-12-08 02:37:59 -080010struct pid_namespace;
Serge E. Hallyn1651e142006-10-02 02:18:08 -070011
Serge E. Hallynab516012006-10-02 02:18:06 -070012/*
13 * A structure to contain pointers to all per-process
14 * namespaces - fs (mount), uts, network, sysvipc, etc.
15 *
16 * 'count' is the number of tasks holding a reference.
17 * The count for each namespace, then, will be the number
18 * of nsproxies pointing to it, not the number of tasks.
19 *
20 * The nsproxy is shared by tasks which share all namespaces.
21 * As soon as a single namespace is cloned or unshared, the
22 * nsproxy is copied.
23 */
24struct nsproxy {
25 atomic_t count;
26 spinlock_t nslock;
Serge E. Hallyn4865ecf2006-10-02 02:18:14 -070027 struct uts_namespace *uts_ns;
Kirill Korotaev25b21cb2006-10-02 02:18:19 -070028 struct ipc_namespace *ipc_ns;
Kirill Korotaev6b3286e2006-12-08 02:37:56 -080029 struct mnt_namespace *mnt_ns;
Cedric Le Goater9a575a92006-12-08 02:37:59 -080030 struct pid_namespace *pid_ns;
Serge E. Hallynab516012006-10-02 02:18:06 -070031};
32extern struct nsproxy init_nsproxy;
33
34struct nsproxy *dup_namespaces(struct nsproxy *orig);
35int copy_namespaces(int flags, struct task_struct *tsk);
36void get_task_namespaces(struct task_struct *tsk);
37void free_nsproxy(struct nsproxy *ns);
38
Linus Torvalds444f3782007-01-30 13:35:18 -080039static inline void put_nsproxy(struct nsproxy *ns)
Serge E. Hallynab516012006-10-02 02:18:06 -070040{
Linus Torvalds444f3782007-01-30 13:35:18 -080041 if (atomic_dec_and_test(&ns->count)) {
Serge E. Hallynab516012006-10-02 02:18:06 -070042 free_nsproxy(ns);
Linus Torvalds444f3782007-01-30 13:35:18 -080043 }
Serge E. Hallynab516012006-10-02 02:18:06 -070044}
45
Linus Torvalds444f3782007-01-30 13:35:18 -080046static inline void exit_task_namespaces(struct task_struct *p)
Serge E. Hallynab516012006-10-02 02:18:06 -070047{
Linus Torvalds444f3782007-01-30 13:35:18 -080048 struct nsproxy *ns = p->nsproxy;
49 if (ns) {
50 task_lock(p);
51 p->nsproxy = NULL;
52 task_unlock(p);
53 put_nsproxy(ns);
54 }
Serge E. Hallynab516012006-10-02 02:18:06 -070055}
56#endif