Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1#ifndef _LINUX_NSPROXY_H
2#define _LINUX_NSPROXY_H
3
4#include <linux/spinlock.h>
5#include <linux/sched.h>
6
7struct mnt_namespace;
8struct uts_namespace;
9struct ipc_namespace;
10struct pid_namespace;
11
12/*
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;
27 struct uts_namespace *uts_ns;
28 struct ipc_namespace *ipc_ns;
29 struct mnt_namespace *mnt_ns;
30 struct pid_namespace *pid_ns;
31};
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
39static inline void put_nsproxy(struct nsproxy *ns)
40{
41 if (atomic_dec_and_test(&ns->count)) {
42 free_nsproxy(ns);
43 }
44}
45
46static inline void exit_task_namespaces(struct task_struct *p)
47{
48 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 }
55}
56#endif