[PATCH v4 1/7] block: Introduce blk_mq_debugfs_init()

[Bart Van Assche <bvanassche@acm.org>]

Move the code for creating the block layer debugfs root directory into
blk-mq-debugfs.c. This patch prepares for adding more debugfs
initialization code by introducing the function blk_mq_debugfs_init().

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 block/blk-core.c       | 3 ++-
 block/blk-mq-debugfs.c | 5 +++++
 block/blk-mq-debugfs.h | 6 ++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index ccf9a7683a3c..0dacc2df9588 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -45,6 +45,7 @@
 #include <trace/events/block.h>
 
 #include "blk.h"
+#include "blk-mq-debugfs.h"
 #include "blk-mq-sched.h"
 #include "blk-pm.h"
 #include "blk-cgroup.h"
@@ -1202,7 +1203,7 @@ int __init blk_dev_init(void)
 	blk_requestq_cachep = kmem_cache_create("request_queue",
 			sizeof(struct request_queue), 0, SLAB_PANIC, NULL);
 
-	blk_debugfs_root = debugfs_create_dir("block", NULL);
+	blk_mq_debugfs_init();
 
 	return 0;
 }
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index bd942341b638..60d1de0ce624 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -874,3 +874,8 @@ void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
 	debugfs_remove_recursive(hctx->sched_debugfs_dir);
 	hctx->sched_debugfs_dir = NULL;
 }
+
+void blk_mq_debugfs_init(void)
+{
+	blk_debugfs_root = debugfs_create_dir("block", NULL);
+}
diff --git a/block/blk-mq-debugfs.h b/block/blk-mq-debugfs.h
index 9c7d4b6117d4..7942119051f5 100644
--- a/block/blk-mq-debugfs.h
+++ b/block/blk-mq-debugfs.h
@@ -17,6 +17,8 @@ struct blk_mq_debugfs_attr {
 	const struct seq_operations *seq_ops;
 };
 
+void blk_mq_debugfs_init(void);
+
 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq);
 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v);
 
@@ -36,6 +38,10 @@ void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);
 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos);
 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos);
 #else
+static inline void blk_mq_debugfs_init(void)
+{
+}
+
 static inline void blk_mq_debugfs_register(struct request_queue *q)
 {
 }