Merge branch 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup changes from Tejun Heo:
 "A lot of activities on cgroup side.  The big changes are focused on
  making cgroup hierarchy handling saner.

   - cgroup_rmdir() had peculiar semantics - it allowed cgroup
     destruction to be vetoed by individual controllers and tried to
     drain refcnt synchronously.  The vetoing never worked properly and
     caused good deal of contortions in cgroup.  memcg was the last
     reamining user.  Michal Hocko removed the usage and cgroup_rmdir()
     path has been simplified significantly.  This was done in a
     separate branch so that the memcg people can base further memcg
     changes on top.

   - The above allowed cleaning up cgroup lifecycle management and
     implementation of generic cgroup iterators which are used to
     improve hierarchy support.

   - cgroup_freezer updated to allow migration in and out of a frozen
     cgroup and handle hierarchy.  If a cgroup is frozen, all descendant
     cgroups are frozen.

   - netcls_cgroup and netprio_cgroup updated to handle hierarchy
     properly.

   - Various fixes and cleanups.

   - Two merge commits.  One to pull in memcg and rmdir cleanups (needed
     to build iterators).  The other pulled in cgroup/for-3.7-fixes for
     device_cgroup fixes so that further device_cgroup patches can be
     stacked on top."

Fixed up a trivial conflict in mm/memcontrol.c as per Tejun (due to
commit bea8c150a7 ("memcg: fix hotplugged memory zone oops") in master
touching code close to commit 2ef37d3fe4 ("memcg: Simplify
mem_cgroup_force_empty_list error handling") in for-3.8)

* 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (65 commits)
  cgroup: update Documentation/cgroups/00-INDEX
  cgroup_rm_file: don't delete the uncreated files
  cgroup: remove subsystem files when remounting cgroup
  cgroup: use cgroup_addrm_files() in cgroup_clear_directory()
  cgroup: warn about broken hierarchies only after css_online
  cgroup: list_del_init() on removed events
  cgroup: fix lockdep warning for event_control
  cgroup: move list add after list head initilization
  netprio_cgroup: allow nesting and inherit config on cgroup creation
  netprio_cgroup: implement netprio[_set]_prio() helpers
  netprio_cgroup: use cgroup->id instead of cgroup_netprio_state->prioidx
  netprio_cgroup: reimplement priomap expansion
  netprio_cgroup: shorten variable names in extend_netdev_table()
  netprio_cgroup: simplify write_priomap()
  netcls_cgroup: move config inheritance to ->css_online() and remove .broken_hierarchy marking
  cgroup: remove obsolete guarantee from cgroup_task_migrate.
  cgroup: add cgroup->id
  cgroup, cpuset: remove cgroup_subsys->post_clone()
  cgroup: s/CGRP_CLONE_CHILDREN/CGRP_CPUSET_CLONE_CHILDREN/
  cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free()
  ...

1 files changed, 16 insertions, 4 deletions

diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index b08d20c66c2e..19ecc8de9e6b 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -82,6 +82,8 @@ static int dev_exceptions_copy(struct list_head *dest, struct list_head *orig)
 {
 	struct dev_exception_item *ex, *tmp, *new;
 
+	lockdep_assert_held(&devcgroup_mutex);
+
 	list_for_each_entry(ex, orig, list) {
 		new = kmemdup(ex, sizeof(*ex), GFP_KERNEL);
 		if (!new)
@@ -107,6 +109,8 @@ static int dev_exception_add(struct dev_cgroup *dev_cgroup,
 {
 	struct dev_exception_item *excopy, *walk;
 
+	lockdep_assert_held(&devcgroup_mutex);
+
 	excopy = kmemdup(ex, sizeof(*ex), GFP_KERNEL);
 	if (!excopy)
 		return -ENOMEM;
@@ -137,6 +141,8 @@ static void dev_exception_rm(struct dev_cgroup *dev_cgroup,
 {
 	struct dev_exception_item *walk, *tmp;
 
+	lockdep_assert_held(&devcgroup_mutex);
+
 	list_for_each_entry_safe(walk, tmp, &dev_cgroup->exceptions, list) {
 		if (walk->type != ex->type)
 			continue;
@@ -163,6 +169,8 @@ static void dev_exception_clean(struct dev_cgroup *dev_cgroup)
 {
 	struct dev_exception_item *ex, *tmp;
 
+	lockdep_assert_held(&devcgroup_mutex);
+
 	list_for_each_entry_safe(ex, tmp, &dev_cgroup->exceptions, list) {
 		list_del_rcu(&ex->list);
 		kfree_rcu(ex, rcu);
@@ -172,7 +180,7 @@ static void dev_exception_clean(struct dev_cgroup *dev_cgroup)
 /*
  * called from kernel/cgroup.c with cgroup_lock() held.
  */
-static struct cgroup_subsys_state *devcgroup_create(struct cgroup *cgroup)
+static struct cgroup_subsys_state *devcgroup_css_alloc(struct cgroup *cgroup)
 {
 	struct dev_cgroup *dev_cgroup, *parent_dev_cgroup;
 	struct cgroup *parent_cgroup;
@@ -202,7 +210,7 @@ static struct cgroup_subsys_state *devcgroup_create(struct cgroup *cgroup)
 	return &dev_cgroup->css;
 }
 
-static void devcgroup_destroy(struct cgroup *cgroup)
+static void devcgroup_css_free(struct cgroup *cgroup)
 {
 	struct dev_cgroup *dev_cgroup;
 
@@ -298,6 +306,10 @@ static int may_access(struct dev_cgroup *dev_cgroup,
 	struct dev_exception_item *ex;
 	bool match = false;
 
+	rcu_lockdep_assert(rcu_read_lock_held() ||
+			   lockdep_is_held(&devcgroup_mutex),
+			   "device_cgroup::may_access() called without proper synchronization");
+
 	list_for_each_entry_rcu(ex, &dev_cgroup->exceptions, list) {
 		if ((refex->type & DEV_BLOCK) && !(ex->type & DEV_BLOCK))
 			continue;
@@ -552,8 +564,8 @@ static struct cftype dev_cgroup_files[] = {
 struct cgroup_subsys devices_subsys = {
 	.name = "devices",
 	.can_attach = devcgroup_can_attach,
-	.create = devcgroup_create,
-	.destroy = devcgroup_destroy,
+	.css_alloc = devcgroup_css_alloc,
+	.css_free = devcgroup_css_free,
 	.subsys_id = devices_subsys_id,
 	.base_cftypes = dev_cgroup_files,