2 files changed, 25 insertions, 0 deletions

diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index d2af87ba96e1..f3da8c0a3af2 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -526,6 +526,23 @@ Who:	FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
 
 ----------------------------
 
+What:   namespace cgroup (ns_cgroup)
+When:   2.6.38
+Why:    The ns_cgroup leads to some problems:
+        * cgroup creation is out-of-control
+        * cgroup name can conflict when pids are looping
+        * it is not possible to have a single process handling
+        a lot of namespaces without falling in a exponential creation time
+        * we may want to create a namespace without creating a cgroup
+
+        The ns_cgroup is replaced by a compatibility flag 'clone_children',
+        where a newly created cgroup will copy the parent cgroup values.
+        The userspace has to manually create a cgroup and add a task to
+        the 'tasks' file.
+Who:    Daniel Lezcano <daniel.lezcano@free.fr>
+
+----------------------------
+
 What:   iwlwifi disable_hw_scan module parameters
 When:   2.6.40
 Why:    Hareware scan is the prefer method for iwlwifi devices for
diff --git a/kernel/ns_cgroup.c b/kernel/ns_cgroup.c
index 2a5dfec8efe0..2c98ad94ba0e 100644
--- a/kernel/ns_cgroup.c
+++ b/kernel/ns_cgroup.c
@@ -85,6 +85,14 @@ static struct cgroup_subsys_state *ns_create(struct cgroup_subsys *ss,
                 return ERR_PTR(-EPERM);
         if (!cgroup_is_descendant(cgroup, current))
                 return ERR_PTR(-EPERM);
+        if (test_bit(CGRP_CLONE_CHILDREN, &cgroup->flags)) {
+                printk("ns_cgroup can't be created with parent "
+                       "'clone_children' set.\n");
+                return ERR_PTR(-EINVAL);
+        }
+
+        printk_once("ns_cgroup deprecated: consider using the "
+                    "'clone_children' flag without the ns_cgroup.\n");
 
         ns_cgroup = kzalloc(sizeof(*ns_cgroup), GFP_KERNEL);
         if (!ns_cgroup)