android_kernel_motorola_sm6225/include/linux/nsproxy.h
Badari Pulavarty e3222c4ecc Merge sys_clone()/sys_unshare() nsproxy and namespace handling
sys_clone() and sys_unshare() both makes copies of nsproxy and its associated
namespaces.  But they have different code paths.

This patch merges all the nsproxy and its associated namespace copy/clone
handling (as much as possible).  Posted on container list earlier for
feedback.

- Create a new nsproxy and its associated namespaces and pass it back to
  caller to attach it to right process.

- Changed all copy_*_ns() routines to return a new copy of namespace
  instead of attaching it to task->nsproxy.

- Moved the CAP_SYS_ADMIN checks out of copy_*_ns() routines.

- Removed unnessary !ns checks from copy_*_ns() and added BUG_ON()
  just incase.

- Get rid of all individual unshare_*_ns() routines and make use of
  copy_*_ns() instead.

[akpm@osdl.org: cleanups, warning fix]
[clg@fr.ibm.com: remove dup_namespaces() declaration]
[serue@us.ibm.com: fix CONFIG_IPC_NS=n, clone(CLONE_NEWIPC) retval]
[akpm@linux-foundation.org: fix build with CONFIG_SYSVIPC=n]
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <containers@lists.osdl.org>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:00 -07:00

57 lines
1.4 KiB
C

#ifndef _LINUX_NSPROXY_H
#define _LINUX_NSPROXY_H
#include <linux/spinlock.h>
#include <linux/sched.h>
struct mnt_namespace;
struct uts_namespace;
struct ipc_namespace;
struct pid_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 ipc_namespace *ipc_ns;
struct mnt_namespace *mnt_ns;
struct pid_namespace *pid_ns;
};
extern struct nsproxy init_nsproxy;
int copy_namespaces(int flags, struct task_struct *tsk);
void get_task_namespaces(struct task_struct *tsk);
void free_nsproxy(struct nsproxy *ns);
int unshare_nsproxy_namespaces(unsigned long, struct nsproxy **,
struct fs_struct *);
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) {
task_lock(p);
p->nsproxy = NULL;
task_unlock(p);
put_nsproxy(ns);
}
}
#endif