Merge branch 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull more cgroup fixes from Tejun Heo:
"Three more patches to fix cgroup_freezer breakage due to the recent
cgroup internal locking changes - an operation cgroup_freezer was
using now requires sleepable context and cgroup_freezer was invoking
that while holding a spin lock. cgroup_freezer was using an overly
elaborate hierarchical locking scheme.
While it's possible to convert the hierarchical spinlocks directly to
mutexes, this patch simplifies the overall locking so that it uses a
global mutex. This has the added benefit of avoiding iterating
potentially huge number of tasks under a spinlock. While the patch is
on the larger side in the devel cycle, the changes made are mostly
straight-forward and the locking logic is a lot simpler afterwards"
* 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix rcu_read_lock() leak in update_if_frozen()
cgroup_freezer: replace freezer->lock with freezer_mutex
cgroup: introduce task_css_is_root()
