bcache: move closure debug file into debug directory

In current code closure debug file is outside of debug directory
and when unloading module there is lack of removing operation
for closure debug file, so it will cause creating error when trying
to reload  module.

This patch move closure debug file into "bcache" debug direcory
so that the file can get deleted properly.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/bcache/closure.c

@@ -157,7 +157,7 @@ void closure_debug_destroy(struct closure *cl)
 }
 EXPORT_SYMBOL(closure_debug_destroy);
 
-static struct dentry *debug;
+static struct dentry *closure_debug;
 
 static int debug_seq_show(struct seq_file *f, void *data)
 {
@@ -199,11 +199,12 @@ static const struct file_operations debug_ops = {
 	.release	= single_release
 };
 
-void __init closure_debug_init(void)
+int __init closure_debug_init(void)
 {
-	debug = debugfs_create_file("closures", 0400, NULL, NULL, &debug_ops);
+	closure_debug = debugfs_create_file("closures",
+				0400, bcache_debug, NULL, &debug_ops);
+	return IS_ERR_OR_NULL(closure_debug);
 }
-
 #endif
 
 MODULE_AUTHOR("Kent Overstreet <koverstreet@google.com>");

drivers/md/bcache/closure.h

@@ -105,6 +105,7 @@
 struct closure;
 struct closure_syncer;
 typedef void (closure_fn) (struct closure *);
+extern struct dentry *bcache_debug;
 
 struct closure_waitlist {
 	struct llist_head	list;
@@ -185,13 +186,13 @@ static inline void closure_sync(struct closure *cl)
 
 #ifdef CONFIG_BCACHE_CLOSURES_DEBUG
 
-void closure_debug_init(void);
+int closure_debug_init(void);
 void closure_debug_create(struct closure *cl);
 void closure_debug_destroy(struct closure *cl);
 
 #else
 
-static inline void closure_debug_init(void) {}
+static inline int closure_debug_init(void) { return 0; }
 static inline void closure_debug_create(struct closure *cl) {}
 static inline void closure_debug_destroy(struct closure *cl) {}
 

drivers/md/bcache/debug.c

@@ -17,7 +17,7 @@
 #include <linux/random.h>
 #include <linux/seq_file.h>
 
-static struct dentry *debug;
+struct dentry *bcache_debug;
 
 #ifdef CONFIG_BCACHE_DEBUG
 
@@ -232,11 +232,11 @@ static const struct file_operations cache_set_debug_ops = {
 
 void bch_debug_init_cache_set(struct cache_set *c)
 {
-	if (!IS_ERR_OR_NULL(debug)) {
+	if (!IS_ERR_OR_NULL(bcache_debug)) {
 		char name[50];
 		snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);
 
-		c->debug = debugfs_create_file(name, 0400, debug, c,
+		c->debug = debugfs_create_file(name, 0400, bcache_debug, c,
 					       &cache_set_debug_ops);
 	}
 }
@@ -245,13 +245,13 @@ void bch_debug_init_cache_set(struct cache_set *c)
 
 void bch_debug_exit(void)
 {
-	if (!IS_ERR_OR_NULL(debug))
-		debugfs_remove_recursive(debug);
+	if (!IS_ERR_OR_NULL(bcache_debug))
+		debugfs_remove_recursive(bcache_debug);
 }
 
 int __init bch_debug_init(struct kobject *kobj)
 {
-	debug = debugfs_create_dir("bcache", NULL);
+	bcache_debug = debugfs_create_dir("bcache", NULL);
 
-	return IS_ERR_OR_NULL(debug);
+	return IS_ERR_OR_NULL(bcache_debug);
 }

drivers/md/bcache/super.c

@@ -2224,7 +2224,6 @@ static int __init bcache_init(void)
 	mutex_init(&bch_register_lock);
 	init_waitqueue_head(&unregister_wait);
 	register_reboot_notifier(&reboot);
-	closure_debug_init();
 
 	bcache_major = register_blkdev(0, "bcache");
 	if (bcache_major < 0) {
@@ -2236,7 +2235,7 @@ static int __init bcache_init(void)
 	if (!(bcache_wq = alloc_workqueue("bcache", WQ_MEM_RECLAIM, 0)) ||
 	    !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) ||
 	    bch_request_init() ||
-	    bch_debug_init(bcache_kobj) ||
+	    bch_debug_init(bcache_kobj) || closure_debug_init() ||
 	    sysfs_create_files(bcache_kobj, files))
 		goto err;