[PATCH v6 02/10] ref_tracker: add a top level debugfs directory for ref_tracker

[Jeff Layton <jlayton@kernel.org>]

Add a new "ref_tracker" directory in debugfs. Each individual refcount
tracker can register files under there to display info about
currently-held references.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 lib/ref_tracker.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c
index de71439e12a3bab6456910986fa611dfbdd97980..a66cde325920780cfe7529ea9d827d0ee943318d 100644
--- a/lib/ref_tracker.c
+++ b/lib/ref_tracker.c
@@ -12,6 +12,8 @@
 #define REF_TRACKER_STACK_ENTRIES 16
 #define STACK_BUF_SIZE 1024
 
+static struct dentry *ref_tracker_debug_dir = (struct dentry *)-ENOENT;
+
 struct ref_tracker {
 	struct list_head	head;   /* anchor into dir->list or dir->quarantine */
 	bool			dead;
@@ -273,3 +275,17 @@ int ref_tracker_free(struct ref_tracker_dir *dir,
 	return 0;
 }
 EXPORT_SYMBOL_GPL(ref_tracker_free);
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+
+static int __init ref_tracker_debugfs_init(void)
+{
+	ref_tracker_debug_dir = debugfs_create_dir("ref_tracker", NULL);
+	if (IS_ERR(ref_tracker_debug_dir))
+		pr_warn("ref_tracker: unable to create debugfs ref_tracker directory: %pe\n",
+			ref_tracker_debug_dir);
+	return 0;
+}
+late_initcall(ref_tracker_debugfs_init);
+#endif /* CONFIG_DEBUG_FS */

-- 
2.49.0