From 784c3b6430dbfe6ff89cd6d997ae369a473323b0 Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Wed, 7 Jan 2009 18:08:46 -0800
Subject: [PATCH] --- yaml --- r: 127616 b: refs/heads/master c:
 f9fb860f67b9542cd78d1558dec7058092b57d8e h: refs/heads/master v: v3

---
 [refs]                    |  2 +-
 trunk/include/linux/pid.h | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index a6097074992a..60b1a042e918 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6af866af34a96fed24a55979a78b6f73bd4e8e87
+refs/heads/master: f9fb860f67b9542cd78d1558dec7058092b57d8e
diff --git a/trunk/include/linux/pid.h b/trunk/include/linux/pid.h
index bb206c56d1f0..49f1c2f66e95 100644
--- a/trunk/include/linux/pid.h
+++ b/trunk/include/linux/pid.h
@@ -122,6 +122,24 @@ int next_pidmap(struct pid_namespace *pid_ns, int last);
 extern struct pid *alloc_pid(struct pid_namespace *ns);
 extern void free_pid(struct pid *pid);
 
+/*
+ * ns_of_pid() returns the pid namespace in which the specified pid was
+ * allocated.
+ *
+ * NOTE:
+ * 	ns_of_pid() is expected to be called for a process (task) that has
+ * 	an attached 'struct pid' (see attach_pid(), detach_pid()) i.e @pid
+ * 	is expected to be non-NULL. If @pid is NULL, caller should handle
+ * 	the resulting NULL pid-ns.
+ */
+static inline struct pid_namespace *ns_of_pid(struct pid *pid)
+{
+	struct pid_namespace *ns = NULL;
+	if (pid)
+		ns = pid->numbers[pid->level].ns;
+	return ns;
+}
+
 /*
  * the helpers to get the pid's id seen from different namespaces
  *