fsnotify: add pr_debug throughout

It can be hard to debug fsnotify since there are so few printks.  Use
pr_debug to allow for dynamic debugging.

Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index b35faaf..e6dde25 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -87,6 +87,8 @@
 		return;
 
 	if (atomic_dec_and_test(&event->refcnt)) {
+		pr_debug("%s: event=%p\n", __func__, event);
+
 		if (event->data_type == FSNOTIFY_EVENT_PATH)
 			path_put(&event->path);
 
@@ -146,6 +148,8 @@
 	struct list_head *list = &group->notification_list;
 	int rc = 0;
 
+	pr_debug("%s: group=%p event=%p priv=%p\n", __func__, group, event, priv);
+
 	/*
 	 * There is one fsnotify_event_holder embedded inside each fsnotify_event.
 	 * Check if we expect to be able to use that holder.  If not alloc a new
@@ -222,6 +226,8 @@
 
 	BUG_ON(!mutex_is_locked(&group->notification_mutex));
 
+	pr_debug("%s: group=%p\n", __func__, group);
+
 	holder = list_first_entry(&group->notification_list, struct fsnotify_event_holder, event_list);
 
 	event = holder->event;
@@ -307,6 +313,8 @@
 		SPINLOCK_NEW,
 	};
 
+	pr_debug("%s: old_event=%p new_event=%p\n", __func__, old_event, new_event);
+
 	/*
 	 * if the new_event's embedded holder is in use someone
 	 * screwed up and didn't give us a clean new event.
@@ -340,6 +348,8 @@
 	if (!event)
 		return NULL;
 
+	pr_debug("%s: old_event=%p new_event=%p\n", __func__, old_event, event);
+
 	memcpy(event, old_event, sizeof(*event));
 	initialize_event(event);
 
@@ -379,6 +389,9 @@
 	if (!event)
 		return NULL;
 
+	pr_debug("%s: event=%p to_tell=%p mask=%x data=%p data_type=%d\n",
+		 __func__, event, to_tell, mask, data, data_type);
+
 	initialize_event(event);
 
 	if (name) {