pid namespaces: helpers to obtain pid numbers

[~andy/linux] / kernel / pid.c

diff --git a/kernel/pid.c b/kernel/pid.c
index 8132a6ddfa10b18396fe07bf53325b44a7628d7d..6eb14841b7346cbbc4387f5e81ba1689375fdc3d 100644 (file)
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -376,6 +376,19 @@ struct pid *find_get_pid(pid_t nr)
        return pid;
 }
 
+pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns)
+{
+       struct upid *upid;
+       pid_t nr = 0;
+
+       if (pid && ns->level <= pid->level) {
+               upid = &pid->numbers[ns->level];
+               if (upid->ns == ns)
+                       nr = upid->nr;
+       }
+       return nr;
+}
+
 /*
  * Used by proc to find the first pid that is greater then or equal to nr.
  *