device_cgroup uses RCU safe ->exceptions list which is write-protected
by devcgroup_mutex and has had some issues using locking correctly.
Add lockdep asserts to utility functions so that future errors can be
easily detected.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NSerge E. Hallyn <serge.hallyn@ubuntu.com>
Cc: Aristeu Rozanski <aris@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>