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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - include/linux/nsproxy.h
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_NSPROXY_H
3 #define _LINUX_NSPROXY_H
5 #include <linux/spinlock.h>
6 #include <linux/sched.h>
12 struct cgroup_namespace
;
16 * A structure to contain pointers to all per-process
17 * namespaces - fs (mount), uts, network, sysvipc, etc.
19 * The pid namespace is an exception -- it's accessed using
20 * task_active_pid_ns. The pid namespace here is the
21 * namespace that children will use.
23 * 'count' is the number of tasks holding a reference.
24 * The count for each namespace, then, will be the number
25 * of nsproxies pointing to it, not the number of tasks.
27 * The nsproxy is shared by tasks which share all namespaces.
28 * As soon as a single namespace is cloned or unshared, the
33 struct uts_namespace
*uts_ns
;
34 struct ipc_namespace
*ipc_ns
;
35 struct mnt_namespace
*mnt_ns
;
36 struct pid_namespace
*pid_ns_for_children
;
38 struct cgroup_namespace
*cgroup_ns
;
40 extern struct nsproxy init_nsproxy
;
43 * the namespaces access rules are:
45 * 1. only current task is allowed to change tsk->nsproxy pointer or
46 * any pointer on the nsproxy itself. Current must hold the task_lock
47 * when changing tsk->nsproxy.
49 * 2. when accessing (i.e. reading) current task's namespaces - no
50 * precautions should be taken - just dereference the pointers
52 * 3. the access to other task namespaces is performed like this
54 * nsproxy = task->nsproxy;
55 * if (nsproxy != NULL) {
57 * * work with the namespaces here
58 * * e.g. get the reference on one of them
61 * * NULL task->nsproxy means that this task is
62 * * almost dead (zombie)
68 int copy_namespaces(unsigned long flags
, struct task_struct
*tsk
);
69 void exit_task_namespaces(struct task_struct
*tsk
);
70 void switch_task_namespaces(struct task_struct
*tsk
, struct nsproxy
*new);
71 void free_nsproxy(struct nsproxy
*ns
);
72 int unshare_nsproxy_namespaces(unsigned long, struct nsproxy
**,
73 struct cred
*, struct fs_struct
*);
74 int __init
nsproxy_cache_init(void);
76 static inline void put_nsproxy(struct nsproxy
*ns
)
78 if (atomic_dec_and_test(&ns
->count
)) {
83 static inline void get_nsproxy(struct nsproxy
*ns
)
85 atomic_inc(&ns
->count
);