cgroup: make cgroup_subsys->base_cftypes use cgroup_add_cftypes()

Currently, cgroup_subsys->base_cftypes registration is different from
dynamic cftypes registartion.  Instead of going through
cgroup_add_cftypes(), cgroup_init_subsys() invokes
cgroup_init_cftsets() which makes use of cgroup_subsys->base_cftset
which doesn't involve dynamic allocation.

While avoiding dynamic allocation is somewhat nice, having two
separate paths for cftypes registration is nasty, especially as we're
planning to add more operations during cftypes registration.

This patch drops cgroup_init_cftsets() and cgroup_subsys->base_cftset
and registers base_cftypes using cgroup_add_cftypes().  This is done
as a separate step in cgroup_init() instead of a part of
cgroup_init_subsys().  This is because cgroup_init_subsys() can be
called very early during boot when kmalloc() isn't available yet.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 1ba4fc08f776..c4350a82320b 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -604,9 +604,8 @@ struct cgroup_subsys {
 	/* list of cftype_sets */
 	struct list_head cftsets;
 
-	/* base cftypes, automatically [de]registered with subsys itself */
+	/* base cftypes, automatically registered with subsys itself */
 	struct cftype *base_cftypes;
-	struct cftype_set base_cftset;
 };
 
 #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;