linux/kernel/nsproxy.c
Serge E. Hallyn ab516013ad [PATCH] namespaces: add nsproxy
This patch adds a nsproxy structure to the task struct.  Later patches will
move the fs namespace pointer into this structure, and introduce a new utsname
namespace into the nsproxy.

The vserver and openvz functionality, then, would be implemented in large part
by virtualizing/isolating more and more resources into namespaces, each
contained in the nsproxy.

[akpm@osdl.org: build fix]
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>
2006-10-02 07:57:20 -07:00

78 lines
1.5 KiB
C

/*
* Copyright (C) 2006 IBM Corporation
*
* Author: Serge Hallyn <serue@us.ibm.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*/
#include <linux/module.h>
#include <linux/version.h>
#include <linux/nsproxy.h>
static inline void get_nsproxy(struct nsproxy *ns)
{
atomic_inc(&ns->count);
}
void get_task_namespaces(struct task_struct *tsk)
{
struct nsproxy *ns = tsk->nsproxy;
if (ns) {
get_nsproxy(ns);
}
}
/*
* creates a copy of "orig" with refcount 1.
* This does not grab references to the contained namespaces,
* so that needs to be done by dup_namespaces.
*/
static inline struct nsproxy *clone_namespaces(struct nsproxy *orig)
{
struct nsproxy *ns;
ns = kmalloc(sizeof(struct nsproxy), GFP_KERNEL);
if (ns) {
memcpy(ns, orig, sizeof(struct nsproxy));
atomic_set(&ns->count, 1);
}
return ns;
}
/*
* copies the nsproxy, setting refcount to 1, and grabbing a
* reference to all contained namespaces. Called from
* sys_unshare()
*/
struct nsproxy *dup_namespaces(struct nsproxy *orig)
{
struct nsproxy *ns = clone_namespaces(orig);
return ns;
}
/*
* called from clone. This now handles copy for nsproxy and all
* namespaces therein.
*/
int copy_namespaces(int flags, struct task_struct *tsk)
{
struct nsproxy *old_ns = tsk->nsproxy;
if (!old_ns)
return 0;
get_nsproxy(old_ns);
return 0;
}
void free_nsproxy(struct nsproxy *ns)
{
kfree(ns);
}