[RFC 1/3] block: move main block debugfs initialization to its own file

From: Luis Chamberlain <mcgrof@kernel.org>
To: axboe@kernel.dk, viro@zeniv.linux.org.uk,
	gregkh@linuxfoundation.org, rostedt@goodmis.org,
	mingo@redhat.com, jack@suse.cz, ming.lei@redhat.com,
	nstange@suse.de
Cc: mhocko@suse.com, linux-block@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Luis Chamberlain <mcgrof@kernel.org>,
	Bart Van Assche <bvanassche@acm.org>,
	Omar Sandoval <osandov@fb.com>, Hannes Reinecke <hare@suse.com>,
	Michal Hocko <mhocko@kernel.org>
Subject: [RFC 1/3] block: move main block debugfs initialization to its own file
Date: Thu,  2 Apr 2020 00:00:00 +0000	[thread overview]
Message-ID: <20200402000002.7442-2-mcgrof@kernel.org> (raw)
In-Reply-To: <20200402000002.7442-1-mcgrof@kernel.org>

Single and multiqeueue block devices share some debugfs code. By
moving this into its own file it makes it easier to expand and audit
this shared code.

This patch contains no functional changes.

Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 block/Makefile      |  1 +
 block/blk-core.c    |  9 +--------
 block/blk-debugfs.c | 15 +++++++++++++++
 block/blk.h         |  7 +++++++
 4 files changed, 24 insertions(+), 8 deletions(-)
 create mode 100644 block/blk-debugfs.c

diff --git a/block/Makefile b/block/Makefile
index 206b96e9387f..1d3ab20505d8 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-sysfs.o \
 			blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \
 			genhd.o ioprio.o badblocks.o partitions/ blk-rq-qos.o
 
+obj-$(CONFIG_DEBUG_FS)		+= blk-debugfs.o
 obj-$(CONFIG_BOUNCE)		+= bounce.o
 obj-$(CONFIG_BLK_SCSI_REQUEST)	+= scsi_ioctl.o
 obj-$(CONFIG_BLK_DEV_BSG)	+= bsg.o
diff --git a/block/blk-core.c b/block/blk-core.c
index 7e4a1da0715e..5aaae7a1b338 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -48,10 +48,6 @@
 #include "blk-pm.h"
 #include "blk-rq-qos.h"
 
-#ifdef CONFIG_DEBUG_FS
-struct dentry *blk_debugfs_root;
-#endif
-
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
@@ -1796,10 +1792,7 @@ int __init blk_dev_init(void)
 
 	blk_requestq_cachep = kmem_cache_create("request_queue",
 			sizeof(struct request_queue), 0, SLAB_PANIC, NULL);
-
-#ifdef CONFIG_DEBUG_FS
-	blk_debugfs_root = debugfs_create_dir("block", NULL);
-#endif
+	blk_debugfs_register();
 
 	return 0;
 }
diff --git a/block/blk-debugfs.c b/block/blk-debugfs.c
new file mode 100644
index 000000000000..634dea4b1507
--- /dev/null
+++ b/block/blk-debugfs.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Shared debugfs mq / non-mq functionality
+ */
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/debugfs.h>
+
+struct dentry *blk_debugfs_root;
+
+void blk_debugfs_register(void)
+{
+	blk_debugfs_root = debugfs_create_dir("block", NULL);
+}
diff --git a/block/blk.h b/block/blk.h
index 0a94ec68af32..86a66b614f08 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -487,5 +487,12 @@ struct request_queue *__blk_alloc_queue(int node_id);
 int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
 		struct page *page, unsigned int len, unsigned int offset,
 		bool *same_page);
+#ifdef CONFIG_DEBUG_FS
+void blk_debugfs_register(void);
+#else
+static inline void blk_debugfs_register(void)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
 
 #endif /* BLK_INTERNAL_H */
-- 
2.25.1

