[PATCH] cgroups: not to iterate other namespace process inside container

[gowrishankar <gomuthuk-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>]

Once tasks are populated from system namespace inside cgroup, container 
replaces
other namespace task with 0 while listing tasks, inside container. 
Though this is expected behaviour
from container end, there is no use of showing unwanted 0s.
In below patch, we check if a process is in same namespace before 
loading into pid array.

Signed-off-by: Gowrishankar M <gowrishankar.m-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
Index: linux-2.6.28-rc3/kernel/cgroup.c
===================================================================
--- linux-2.6.28-rc3.orig/kernel/cgroup.c    2008-12-07 
13:23:19.000000000 -0500
+++ linux-2.6.28-rc3/kernel/cgroup.c    2008-12-07 13:24:28.000000000 -0500
@@ -2011,14 +2011,15 @@
  */
 static int pid_array_load(pid_t *pidarray, int npids, struct cgroup *cgrp)
 {
-    int n = 0;
+    int n = 0, ret;
     struct cgroup_iter it;
     struct task_struct *tsk;
     cgroup_iter_start(cgrp, &it);
     while ((tsk = cgroup_iter_next(cgrp, &it))) {
         if (unlikely(n == npids))
             break;
-        pidarray[n++] = task_pid_vnr(tsk);
+        if ((ret = task_pid_vnr(tsk)) > 0)
+            pidarray[n++] = ret;
     }
     cgroup_iter_end(cgrp, &it);
     return n;