1651e14e28
This moves the mount namespace into the nsproxy. The mount namespace count now refers to the number of nsproxies point to it, rather than the number of tasks. As a result, the unshare_namespace() function in kernel/fork.c no longer checks whether it is being shared. Signed-off-by: Serge Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Andrey Savochkin <saw@sw.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
49 lines
1.1 KiB
C
49 lines
1.1 KiB
C
#ifndef _LINUX_NSPROXY_H
|
|
#define _LINUX_NSPROXY_H
|
|
|
|
#include <linux/spinlock.h>
|
|
#include <linux/sched.h>
|
|
|
|
struct 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 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
|