Merge branch 'for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup changes from Tejun Heo:

 - Waiman made the debug controller work and a lot more useful on
   cgroup2

 - There were a couple issues with cgroup subtree delegation. The
   documentation on delegating to a non-root user was missing some part
   and cgroup namespace support wasn't factoring in delegation at all.
   The documentation is updated and the now there is a mount option to
   make cgroup namespace fit for delegation

* 'for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: implement "nsdelegate" mount option
  cgroup: restructure cgroup_procs_write_permission()
  cgroup: "cgroup.subtree_control" should be writeable by delegatee
  cgroup: fix lockdep warning in debug controller
  cgroup: refactor cgroup_masks_read() in the debug controller
  cgroup: make debug an implicit controller on cgroup2
  cgroup: Make debug cgroup support v2 and thread mode
  cgroup: Make Kconfig prompt of debug cgroup more accurate
  cgroup: Move debug cgroup to its own file
  cgroup: Keep accurate count of tasks in each css_set

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index ec47101cb1bf..09f4c7df1478 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -67,12 +67,21 @@ enum {
 enum {
 	CGRP_ROOT_NOPREFIX	= (1 << 1), /* mounted subsystems have no named prefix */
 	CGRP_ROOT_XATTR		= (1 << 2), /* supports extended attributes */
+
+	/*
+	 * Consider namespaces as delegation boundaries.  If this flag is
+	 * set, controller specific interface files in a namespace root
+	 * aren't writeable from inside the namespace.
+	 */
+	CGRP_ROOT_NS_DELEGATE	= (1 << 3),
 };
 
 /* cftype->flags */
 enum {
 	CFTYPE_ONLY_ON_ROOT	= (1 << 0),	/* only create on root cgrp */
 	CFTYPE_NOT_ON_ROOT	= (1 << 1),	/* don't create on root cgrp */
+	CFTYPE_NS_DELEGATABLE	= (1 << 2),	/* writeable beyond delegation boundaries */
+
 	CFTYPE_NO_PREFIX	= (1 << 3),	/* (DON'T USE FOR NEW FILES) no subsys prefix */
 	CFTYPE_WORLD_WRITABLE	= (1 << 4),	/* (DON'T USE FOR NEW FILES) S_IWUGO */
 
@@ -166,6 +175,9 @@ struct css_set {
 	/* the default cgroup associated with this css_set */
 	struct cgroup *dfl_cgrp;
 
+	/* internal task count, protected by css_set_lock */
+	int nr_tasks;
+
 	/*
 	 * Lists running through all tasks using this cgroup group.
 	 * mg_tasks lists tasks which belong to this cset but are in the