1 files changed, 23 insertions, 1 deletions

diff --git a/include/linux/pid.h b/include/linux/pid.h
index 67470ade3212..c5fee61bfb4f 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -114,11 +114,33 @@ extern struct pid *find_ge_pid(int nr);
 extern struct pid *alloc_pid(struct pid_namespace *ns);
 extern void FASTCALL(free_pid(struct pid *pid));
 
+/*
+ * the helpers to get the pid's id seen from different namespaces
+ *
+ * pid_nr()    : global id, i.e. the id seen from the init namespace;
+ * pid_vnr()   : virtual id, i.e. the id seen from the namespace this pid
+ *               belongs to. this only makes sence when called in the
+ *               context of the task that belongs to the same namespace;
+ * pid_nr_ns() : id seen from the ns specified.
+ *
+ * see also task_xid_nr() etc in include/linux/sched.h
+ */
+
 static inline pid_t pid_nr(struct pid *pid)
 {
         pid_t nr = 0;
         if (pid)
-                nr = pid->nr;
+                nr = pid->numbers[0].nr;
+        return nr;
+}
+
+pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns);
+
+static inline pid_t pid_vnr(struct pid *pid)
+{
+        pid_t nr = 0;
+        if (pid)
+                nr = pid->numbers[pid->level].nr;
         return nr;
 }