[PATCH 5/6] tracing: Introduce remove_event_file_dir()

[Oleg Nesterov <oleg@redhat.com>]

Preparation for the next patch. Extract the common code from
remove_event_from_tracers() and __trace_remove_event_dirs()
into the new helper, remove_event_file_dir().

The patch looks more complicated than it actually is, it also
moves remove_subsystem() up to avoid the forward declaration.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 kernel/trace/trace_events.c |   66 +++++++++++++++++++++----------------------
 1 files changed, 32 insertions(+), 34 deletions(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 4b43111..3ae037c 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -409,11 +409,31 @@ static void put_system(struct ftrace_subsystem_dir *dir)
 	mutex_unlock(&event_mutex);
 }
 
+static void remove_subsystem(struct ftrace_subsystem_dir *dir)
+{
+	if (!dir)
+		return;
+
+	if (!--dir->nr_events) {
+		debugfs_remove_recursive(dir->entry);
+		list_del(&dir->list);
+		__put_system_dir(dir);
+	}
+}
+
 static void *event_file_data(struct file *filp)
 {
 	return ACCESS_ONCE(file_inode(filp)->i_private);
 }
 
+static void remove_event_file_dir(struct ftrace_event_file *file)
+{
+	list_del(&file->list);
+	debugfs_remove_recursive(file->dir);
+	remove_subsystem(file->system);
+	kmem_cache_free(file_cachep, file);
+}
+
 /*
  * Open and update trace_array ref count.
  * Must have the current trace_array passed to it.
@@ -1542,40 +1562,22 @@ event_create_dir(struct dentry *parent,
 	return 0;
 }
 
-static void remove_subsystem(struct ftrace_subsystem_dir *dir)
-{
-	if (!dir)
-		return;
-
-	if (!--dir->nr_events) {
-		debugfs_remove_recursive(dir->entry);
-		list_del(&dir->list);
-		__put_system_dir(dir);
-	}
-}
-
 static void remove_event_from_tracers(struct ftrace_event_call *call)
 {
 	struct ftrace_event_file *file;
 	struct trace_array *tr;
 
 	do_for_each_event_file_safe(tr, file) {
-
-		if (file->event_call != call)
-			continue;
-
-		list_del(&file->list);
-		debugfs_remove_recursive(file->dir);
-		remove_subsystem(file->system);
-		kmem_cache_free(file_cachep, file);
-
-		/*
-		 * The do_for_each_event_file_safe() is
-		 * a double loop. After finding the call for this
-		 * trace_array, we use break to jump to the next
-		 * trace_array.
-		 */
-		break;
+		if (file->event_call == call) {
+			remove_event_file_dir(file);
+			/*
+			 * The do_for_each_event_file_safe() is
+			 * a double loop. After finding the call for this
+			 * trace_array, we use break to jump to the next
+			 * trace_array.
+			 */
+			break;
+		}
 	} while_for_each_event_file();
 }
 
@@ -2298,12 +2300,8 @@ __trace_remove_event_dirs(struct trace_array *tr)
 {
 	struct ftrace_event_file *file, *next;
 
-	list_for_each_entry_safe(file, next, &tr->events, list) {
-		list_del(&file->list);
-		debugfs_remove_recursive(file->dir);
-		remove_subsystem(file->system);
-		kmem_cache_free(file_cachep, file);
-	}
+	list_for_each_entry_safe(file, next, &tr->events, list)
+		remove_event_file_dir(file);
 }
 
 static void
-- 
1.5.5.1