ns: add NS_COMMON_INIT()

Add an initializer that can be used for the ns common initialization for
static namespace such as most init namespaces.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/87ecqhy2y5.ffs@tglx
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h
index f5b68b8abb5433fe78b5a2e29cbd3fbd3dcc5c97..3a72c3f81eca421a16a0b6bacc398a96f905e0c0 100644 (file)
--- a/include/linux/ns_common.h
+++ b/include/linux/ns_common.h
@@ -119,6 +119,16 @@ void __ns_common_free(struct ns_common *ns);
                struct user_namespace *:   CLONE_NEWUSER,   \
                struct uts_namespace *:    CLONE_NEWUTS)
 
+#define NS_COMMON_INIT(nsname, refs)                                                   \
+{                                                                                      \
+       .ns_type                = ns_common_type(&nsname),                              \
+       .ns_id                  = 0,                                                    \
+       .inum                   = ns_init_inum(&nsname),                                \
+       .ops                    = to_ns_operations(&nsname),                            \
+       .stashed                = NULL,                                                 \
+       .__ns_ref               = REFCOUNT_INIT(refs),                                  \
+}
+
 #define ns_common_init(__ns)                     \
        __ns_common_init(to_ns_common(__ns),     \
                         ns_common_type(__ns),   \