[PATCH] namespaces: utsname: implement utsname namespaces
This patch defines the uts namespace and some manipulators.
Adds the uts namespace to task_struct, and initializes a
system-wide init namespace.
It leaves a #define for system_utsname so sysctl will compile.
This define will be removed in a separate patch.
[akpm@osdl.org: build fix, cleanup]
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>
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 4865348..e08531e 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -4,6 +4,7 @@
#include <linux/file.h>
#include <linux/rcupdate.h>
#include <linux/irqflags.h>
+#include <linux/utsname.h>
#include <linux/lockdep.h>
#define INIT_FDTABLE \
@@ -72,6 +73,7 @@
#define INIT_NSPROXY(nsproxy) { \
.count = ATOMIC_INIT(1), \
.nslock = SPIN_LOCK_UNLOCKED, \
+ .uts_ns = &init_uts_ns, \
.namespace = NULL, \
}
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
index 7ebe666..9c2e0ad 100644
--- a/include/linux/nsproxy.h
+++ b/include/linux/nsproxy.h
@@ -5,6 +5,7 @@
#include <linux/sched.h>
struct namespace;
+struct uts_namespace;
/*
* A structure to contain pointers to all per-process
@@ -21,6 +22,7 @@
struct nsproxy {
atomic_t count;
spinlock_t nslock;
+ struct uts_namespace *uts_ns;
struct namespace *namespace;
};
extern struct nsproxy init_nsproxy;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 670b89a..46d6f5b 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -753,6 +753,7 @@
struct audit_context; /* See audit.c */
struct mempolicy;
struct pipe_inode_info;
+struct uts_namespace;
enum sleep_type {
SLEEP_NORMAL,
diff --git a/include/linux/utsname.h b/include/linux/utsname.h
index 77e97a5..afa54e1 100644
--- a/include/linux/utsname.h
+++ b/include/linux/utsname.h
@@ -1,6 +1,11 @@
#ifndef _LINUX_UTSNAME_H
#define _LINUX_UTSNAME_H
+#include <linux/sched.h>
+#include <linux/kref.h>
+#include <linux/nsproxy.h>
+#include <asm/atomic.h>
+
#define __OLD_UTS_LEN 8
struct oldold_utsname {
@@ -30,17 +35,46 @@
char domainname[65];
};
-extern struct new_utsname system_utsname;
+struct uts_namespace {
+ struct kref kref;
+ struct new_utsname name;
+};
+extern struct uts_namespace init_uts_ns;
+
+static inline void get_uts_ns(struct uts_namespace *ns)
+{
+ kref_get(&ns->kref);
+}
+
+#ifdef CONFIG_UTS_NS
+extern int copy_utsname(int flags, struct task_struct *tsk);
+extern void free_uts_ns(struct kref *kref);
+
+static inline void put_uts_ns(struct uts_namespace *ns)
+{
+ kref_put(&ns->kref, free_uts_ns);
+}
+#else
+static inline int copy_utsname(int flags, struct task_struct *tsk)
+{
+ return 0;
+}
+static inline void put_uts_ns(struct uts_namespace *ns)
+{
+}
+#endif
static inline struct new_utsname *utsname(void)
{
- return &system_utsname;
+ return ¤t->nsproxy->uts_ns->name;
}
static inline struct new_utsname *init_utsname(void)
{
- return &system_utsname;
+ return &init_uts_ns.name;
}
+#define system_utsname init_uts_ns.name
+
extern struct rw_semaphore uts_sem;
#endif