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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 time_namespace
*time_ns
;
39 struct time_namespace
*time_ns_for_children
;
40 struct cgroup_namespace
*cgroup_ns
;
42 extern struct nsproxy init_nsproxy
;
45 * the namespaces access rules are:
47 * 1. only current task is allowed to change tsk->nsproxy pointer or
48 * any pointer on the nsproxy itself. Current must hold the task_lock
49 * when changing tsk->nsproxy.
51 * 2. when accessing (i.e. reading) current task's namespaces - no
52 * precautions should be taken - just dereference the pointers
54 * 3. the access to other task namespaces is performed like this
56 * nsproxy = task->nsproxy;
57 * if (nsproxy != NULL) {
59 * * work with the namespaces here
60 * * e.g. get the reference on one of them
63 * * NULL task->nsproxy means that this task is
64 * * almost dead (zombie)
70 int copy_namespaces(unsigned long flags
, struct task_struct
*tsk
);
71 void exit_task_namespaces(struct task_struct
*tsk
);
72 void switch_task_namespaces(struct task_struct
*tsk
, struct nsproxy
*new);
73 void free_nsproxy(struct nsproxy
*ns
);
74 int unshare_nsproxy_namespaces(unsigned long, struct nsproxy
**,
75 struct cred
*, struct fs_struct
*);
76 int __init
nsproxy_cache_init(void);
78 static inline void put_nsproxy(struct nsproxy
*ns
)
80 if (atomic_dec_and_test(&ns
->count
)) {
85 static inline void get_nsproxy(struct nsproxy
*ns
)
87 atomic_inc(&ns
->count
);