[deliverable/linux.git] / include / linux / nsproxy.h

#ifndef _LINUX_NSPROXY_H
#define _LINUX_NSPROXY_H

#include <linux/spinlock.h>
#include <linux/sched.h>

struct namespace;
struct uts_namespace;

/*
 * A structure to contain pointers to all per-process
 * namespaces - fs (mount), uts, network, sysvipc, etc.
 *
 * 'count' is the number of tasks holding a reference.
 * The count for each namespace, then, will be the number
 * of nsproxies pointing to it, not the number of tasks.
 *
 * The nsproxy is shared by tasks which share all namespaces.
 * As soon as a single namespace is cloned or unshared, the
 * nsproxy is copied.
 */
struct nsproxy {
	atomic_t count;
	spinlock_t nslock;
	struct uts_namespace *uts_ns;
	struct namespace *namespace;
};
extern struct nsproxy init_nsproxy;

struct nsproxy *dup_namespaces(struct nsproxy *orig);
int copy_namespaces(int flags, struct task_struct *tsk);
void get_task_namespaces(struct task_struct *tsk);
void free_nsproxy(struct nsproxy *ns);

static inline void put_nsproxy(struct nsproxy *ns)
{
	if (atomic_dec_and_test(&ns->count)) {
		free_nsproxy(ns);
	}
}

static inline void exit_task_namespaces(struct task_struct *p)
{
	struct nsproxy *ns = p->nsproxy;
	if (ns) {
		put_nsproxy(ns);
		p->nsproxy = NULL;
	}
}
#endif
Commit	Line	Data
ab516013 SH	1	#ifndef _LINUX_NSPROXY_H
	2	#define _LINUX_NSPROXY_H
	3
	4	#include <linux/spinlock.h>
	5	#include <linux/sched.h>
	6
1651e14e	7	struct namespace;
4865ecf1	8	struct uts_namespace;
1651e14e	9
ab516013 SH	10	/*
	11	* A structure to contain pointers to all per-process
	12	* namespaces - fs (mount), uts, network, sysvipc, etc.
	13	*
	14	* 'count' is the number of tasks holding a reference.
	15	* The count for each namespace, then, will be the number
	16	* of nsproxies pointing to it, not the number of tasks.
	17	*
	18	* The nsproxy is shared by tasks which share all namespaces.
	19	* As soon as a single namespace is cloned or unshared, the
	20	* nsproxy is copied.
	21	*/
	22	struct nsproxy {
	23	atomic_t count;
	24	spinlock_t nslock;
4865ecf1	25	struct uts_namespace *uts_ns;
1651e14e	26	struct namespace *namespace;
ab516013 SH	27	};
	28	extern struct nsproxy init_nsproxy;
	29
	30	struct nsproxy dup_namespaces(struct nsproxy orig);
	31	int copy_namespaces(int flags, struct task_struct *tsk);
	32	void get_task_namespaces(struct task_struct *tsk);
	33	void free_nsproxy(struct nsproxy *ns);
	34
	35	static inline void put_nsproxy(struct nsproxy *ns)
	36	{
	37	if (atomic_dec_and_test(&ns->count)) {
	38	free_nsproxy(ns);
	39	}
	40	}
	41
	42	static inline void exit_task_namespaces(struct task_struct *p)
	43	{
	44	struct nsproxy *ns = p->nsproxy;
	45	if (ns) {
	46	put_nsproxy(ns);
	47	p->nsproxy = NULL;
	48	}
	49	}
	50	#endif