blkcg: mark existing cftypes as legacy

blkcg is about to grow interface for the unified hierarchy.  Add
legacy to existing cftypes.

* blkcg_policy->cftypes -> blkcg_policy->legacy_cftypes
* blk-cgroup.c:blkcg_files -> blkcg_legacy_files
* cfq-iosched.c:cfq_blkcg_files -> cfq_blkcg_legacy_files
* blk-throttle.c:throtl_files -> throtl_legacy_files

Pure renames.  No functional change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

block/blk-cgroup.c

@@ -847,7 +847,7 @@ void blkg_conf_finish(struct blkg_conf_ctx *ctx)
 }
 EXPORT_SYMBOL_GPL(blkg_conf_finish);
 
-struct cftype blkcg_files[] = {
+struct cftype blkcg_legacy_files[] = {
 	{
 		.name = "reset_stats",
 		.write_u64 = blkcg_reset_stats,
@@ -1094,7 +1094,7 @@ struct cgroup_subsys io_cgrp_subsys = {
 	.css_offline = blkcg_css_offline,
 	.css_free = blkcg_css_free,
 	.can_attach = blkcg_can_attach,
-	.legacy_cftypes = blkcg_files,
+	.legacy_cftypes = blkcg_legacy_files,
 	.legacy_name = "blkio",
 #ifdef CONFIG_MEMCG
 	/*
@@ -1266,9 +1266,9 @@ int blkcg_policy_register(struct blkcg_policy *pol)
 	mutex_unlock(&blkcg_pol_mutex);
 
 	/* everything is in place, add intf files for the new policy */
-	if (pol->cftypes)
+	if (pol->legacy_cftypes)
 		WARN_ON(cgroup_add_legacy_cftypes(&io_cgrp_subsys,
-						  pol->cftypes));
+						  pol->legacy_cftypes));
 	mutex_unlock(&blkcg_pol_register_mutex);
 	return 0;
 
@@ -1305,8 +1305,8 @@ void blkcg_policy_unregister(struct blkcg_policy *pol)
 		goto out_unlock;
 
 	/* kill the intf files first */
-	if (pol->cftypes)
-		cgroup_rm_cftypes(pol->cftypes);
+	if (pol->legacy_cftypes)
+		cgroup_rm_cftypes(pol->legacy_cftypes);
 
 	/* remove cpds and unregister */
 	mutex_lock(&blkcg_pol_mutex);

block/blk-throttle.c

@@ -1217,7 +1217,7 @@ static ssize_t tg_set_conf_uint(struct kernfs_open_file *of,
 	return tg_set_conf(of, buf, nbytes, off, false);
 }
 
-static struct cftype throtl_files[] = {
+static struct cftype throtl_legacy_files[] = {
 	{
 		.name = "throttle.read_bps_device",
 		.private = offsetof(struct throtl_grp, bps[READ]),
@@ -1263,7 +1263,7 @@ static void throtl_shutdown_wq(struct request_queue *q)
 }
 
 static struct blkcg_policy blkcg_policy_throtl = {
-	.cftypes		= throtl_files,
+	.legacy_cftypes		= throtl_legacy_files,
 
 	.pd_alloc_fn		= throtl_pd_alloc,
 	.pd_init_fn		= throtl_pd_init,

block/cfq-iosched.c

@@ -1944,7 +1944,7 @@ static int cfqg_print_avg_queue_size(struct seq_file *sf, void *v)
 }
 #endif	/* CONFIG_DEBUG_BLK_CGROUP */
 
-static struct cftype cfq_blkcg_files[] = {
+static struct cftype cfq_blkcg_legacy_files[] = {
 	/* on root, weight is mapped to leaf_weight */
 	{
 		.name = "weight_device",
@@ -4654,7 +4654,7 @@ static struct elevator_type iosched_cfq = {
 
 #ifdef CONFIG_CFQ_GROUP_IOSCHED
 static struct blkcg_policy blkcg_policy_cfq = {
-	.cftypes		= cfq_blkcg_files,
+	.legacy_cftypes		= cfq_blkcg_legacy_files,
 
 	.cpd_alloc_fn		= cfq_cpd_alloc,
 	.cpd_init_fn		= cfq_cpd_init,

include/linux/blk-cgroup.h

@@ -148,7 +148,7 @@ typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd);
 struct blkcg_policy {
 	int				plid;
 	/* cgroup files for the policy */
-	struct cftype			*cftypes;
+	struct cftype			*legacy_cftypes;
 
 	/* operations */
 	blkcg_pol_alloc_cpd_fn		*cpd_alloc_fn;