[PATCH] blk-cgroup: provide stubs for blkcg_get_fc_appid()

[Hannes Reinecke <hare@suse.de>]

Provide stubs for blkcg_set_fc_appid() and  blkcg_get_fc_appid() to allow
for compilation with cgroups disabled.

Fixes: db05628435aa ("blk-cgroup: move blkcg_{get,set}_fc_appid out of line")
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 include/linux/blk-cgroup.h | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 9f40dbc65f82..4756f4d2b8e7 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -33,6 +33,9 @@ void blkcg_unpin_online(struct cgroup_subsys_state *blkcg_css);
 struct list_head *blkcg_get_cgwb_list(struct cgroup_subsys_state *css);
 struct cgroup_subsys_state *bio_blkcg_css(struct bio *bio);
 
+int blkcg_set_fc_appid(char *app_id, u64 cgrp_id, size_t app_id_len);
+char *blkcg_get_fc_appid(struct bio *bio);
+
 #else	/* CONFIG_BLK_CGROUP */
 
 #define blkcg_root_css	((struct cgroup_subsys_state *)ERR_PTR(-EINVAL))
@@ -44,9 +47,15 @@ static inline struct cgroup_subsys_state *bio_blkcg_css(struct bio *bio)
 {
 	return NULL;
 }
+static inline int blkcg_set_fc_appid(char *app_id, u64 cgrp_id,
+				     size_t app_id_len)
+{
+	return -EINVAL;
+}
+static inline char *blkcg_get_fc_appid(struct bio *bio)
+{
+	return NULL;
+}
 #endif	/* CONFIG_BLK_CGROUP */
 
-int blkcg_set_fc_appid(char *app_id, u64 cgrp_id, size_t app_id_len);
-char *blkcg_get_fc_appid(struct bio *bio);
-
 #endif	/* _BLK_CGROUP_H */
-- 
2.29.2