From 9a575a92db3312a40cdf0b0406d88de88ad9741e Mon Sep 17 00:00:00 2001
From: Cedric Le Goater <clg@fr.ibm.com>
Date: Fri, 8 Dec 2006 02:37:59 -0800
Subject: [PATCH] to nsproxy

Add the pid namespace framework to the nsproxy object.  The copy of the pid
namespace only increases the refcount on the global pid namespace,
init_pid_ns, and unshare is not implemented.

There is no configuration option to activate or deactivate this feature
because this not relevant for the moment.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 include/linux/init_task.h     |  2 ++
 include/linux/nsproxy.h       |  2 ++
 include/linux/pid_namespace.h | 20 ++++++++++++++++++--
 3 files changed, 22 insertions(+), 2 deletions(-)

(limited to 'include')

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 90c5f9a0773..7272ff9ee77 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -7,6 +7,7 @@
 #include <linux/utsname.h>
 #include <linux/lockdep.h>
 #include <linux/ipc.h>
+#include <linux/pid_namespace.h>
 
 #define INIT_FDTABLE \
 {							\
@@ -73,6 +74,7 @@
 
 extern struct nsproxy init_nsproxy;
 #define INIT_NSPROXY(nsproxy) {						\
+	.pid_ns		= &init_pid_ns,					\
 	.count		= ATOMIC_INIT(1),				\
 	.nslock		= __SPIN_LOCK_UNLOCKED(nsproxy.nslock),		\
 	.id		= 0,						\
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
index 27f37c1ec1d..fdfb0e44912 100644
--- a/include/linux/nsproxy.h
+++ b/include/linux/nsproxy.h
@@ -7,6 +7,7 @@
 struct mnt_namespace;
 struct uts_namespace;
 struct ipc_namespace;
+struct pid_namespace;
 
 /*
  * A structure to contain pointers to all per-process
@@ -27,6 +28,7 @@ struct nsproxy {
 	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;
 
diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
index 54d79095e29..76e7c6b2cf3 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -5,6 +5,8 @@
 #include <linux/mm.h>
 #include <linux/threads.h>
 #include <linux/pid.h>
+#include <linux/nsproxy.h>
+#include <linux/kref.h>
 
 struct pidmap {
        atomic_t nr_free;
@@ -14,10 +16,24 @@ struct pidmap {
 #define PIDMAP_ENTRIES         ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8)
 
 struct pid_namespace {
-       struct pidmap pidmap[PIDMAP_ENTRIES];
-       int last_pid;
+	struct kref kref;
+	struct pidmap pidmap[PIDMAP_ENTRIES];
+	int last_pid;
 };
 
 extern struct pid_namespace init_pid_ns;
 
+static inline void get_pid_ns(struct pid_namespace *ns)
+{
+	kref_get(&ns->kref);
+}
+
+extern int copy_pid_ns(int flags, struct task_struct *tsk);
+extern void free_pid_ns(struct kref *kref);
+
+static inline void put_pid_ns(struct pid_namespace *ns)
+{
+	kref_put(&ns->kref, free_pid_ns);
+}
+
 #endif /* _LINUX_PID_NS_H */
-- 
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