cgroup: notify ns_cgroup deprecated
The ns_cgroup will be removed very soon. Let's warn, for this version,
ns_cgroup is deprecated.
Make ns_cgroup and clone_children exclusive. If the clone_children is set
and the ns_cgroup is mounted, let's fail with EINVAL when the ns_cgroup
subsys is created (a printk will help the user to understand why the
creation fails).
Update the feature remove schedule file with the deprecated ns_cgroup.
Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index d2af87b..f3da8c0 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -526,6 +526,23 @@
----------------------------
+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 2a5dfec..2c98ad9 100644
--- a/kernel/ns_cgroup.c
+++ b/kernel/ns_cgroup.c
@@ -85,6 +85,14 @@
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)