[PATCH] IPC namespace - utils

This patch adds basic IPC namespace functionality to
IPC utils:
- init_ipc_ns
- copy/clone/unshare/free IPC ns
- /proc preparations

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 20 insertions, 1 deletions

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index ceecf69dfa39..33c5daacc743 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -6,6 +6,7 @@
 #include <linux/irqflags.h>
 #include <linux/utsname.h>
 #include <linux/lockdep.h>
+#include <linux/ipc.h>
 
 #define INIT_FDTABLE \
 {                                                       \
@@ -74,8 +75,8 @@ extern struct nsproxy init_nsproxy;
         .count          = ATOMIC_INIT(1),                               \
         .nslock         = SPIN_LOCK_UNLOCKED,                           \
         .uts_ns         = &init_uts_ns,                                 \
-        .ipc_ns         = &init_ipc_ns,                                 \
         .namespace      = NULL,                                         \
+        INIT_IPC_NS(ipc_ns)                                             \
 }
 
 #define INIT_SIGHAND(sighand) {                                         \
diff --git a/include/linux/ipc.h b/include/linux/ipc.h
index 36027b10f283..d9e2b3f36c35 100644
--- a/include/linux/ipc.h
+++ b/include/linux/ipc.h
@@ -88,20 +88,38 @@ struct ipc_namespace {
 };
 
 extern struct ipc_namespace init_ipc_ns;
+
+#ifdef CONFIG_SYSVIPC
+#define INIT_IPC_NS(ns)         .ns             = &init_ipc_ns,
+#else
+#define INIT_IPC_NS(ns)
+#endif
+
+#ifdef CONFIG_IPC_NS
 extern void free_ipc_ns(struct kref *kref);
 extern int copy_ipcs(unsigned long flags, struct task_struct *tsk);
 extern int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns);
+#else
+static inline int copy_ipcs(unsigned long flags, struct task_struct *tsk)
+{
+        return 0;
+}
+#endif
 
 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 {
+#ifdef CONFIG_IPC_NS
         if (ns)
                 kref_get(&ns->kref);
+#endif
         return ns;
 }
 
 static inline void put_ipc_ns(struct ipc_namespace *ns)
 {
+#ifdef CONFIG_IPC_NS
         kref_put(&ns->kref, free_ipc_ns);
+#endif
 }
 
 #endif /* __KERNEL__ */