---

yaml
---
r: 364910
b: refs/heads/master
c: 0c8916c
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 277ba04461c2746cf935353474c0961161951b68
+refs/heads/master: 0c8916c34203734d3b05953ebace52d7c2969f16

trunk/kernel/trace/trace.c

@@ -5192,6 +5192,42 @@ static int new_instance_create(const char *name)
 
 }
 
+static int instance_delete(const char *name)
+{
+	struct trace_array *tr;
+	int found = 0;
+	int ret;
+
+	mutex_lock(&trace_types_lock);
+
+	ret = -ENODEV;
+	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+		if (tr->name && strcmp(tr->name, name) == 0) {
+			found = 1;
+			break;
+		}
+	}
+	if (!found)
+		goto out_unlock;
+
+	list_del(&tr->list);
+
+	event_trace_del_tracer(tr);
+	debugfs_remove_recursive(tr->dir);
+	free_percpu(tr->data);
+	ring_buffer_free(tr->buffer);
+
+	kfree(tr->name);
+	kfree(tr);
+
+	ret = 0;
+
+ out_unlock:
+	mutex_unlock(&trace_types_lock);
+
+	return ret;
+}
+
 static int instance_mkdir (struct inode *inode, struct dentry *dentry, umode_t mode)
 {
 	struct dentry *parent;
@@ -5219,9 +5255,41 @@ static int instance_mkdir (struct inode *inode, struct dentry *dentry, umode_t m
 	return ret;
 }
 
+static int instance_rmdir(struct inode *inode, struct dentry *dentry)
+{
+	struct dentry *parent;
+	int ret;
+
+	/* Paranoid: Make sure the parent is the "instances" directory */
+	parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
+	if (WARN_ON_ONCE(parent != trace_instance_dir))
+		return -ENOENT;
+
+	/* The caller did a dget() on dentry */
+	mutex_unlock(&dentry->d_inode->i_mutex);
+
+	/*
+	 * The inode mutex is locked, but debugfs_create_dir() will also
+	 * take the mutex. As the instances directory can not be destroyed
+	 * or changed in any other way, it is safe to unlock it, and
+	 * let the dentry try. If two users try to make the same dir at
+	 * the same time, then the instance_delete() will determine the
+	 * winner.
+	 */
+	mutex_unlock(&inode->i_mutex);
+
+	ret = instance_delete(dentry->d_iname);
+
+	mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
+	mutex_lock(&dentry->d_inode->i_mutex);
+
+	return ret;
+}
+
 static const struct inode_operations instance_dir_inode_operations = {
 	.lookup		= simple_lookup,
 	.mkdir		= instance_mkdir,
+	.rmdir		= instance_rmdir,
 };
 
 static __init void create_trace_instances(struct dentry *d_tracer)

trunk/kernel/trace/trace.h

@@ -1001,6 +1001,7 @@ filter_check_discard(struct ftrace_event_call *call, void *rec,
 
 extern void trace_event_enable_cmd_record(bool enable);
 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
+extern int event_trace_del_tracer(struct trace_array *tr);
 
 extern struct mutex event_mutex;
 extern struct list_head ftrace_events;

trunk/kernel/trace/trace_events.c

@@ -1709,6 +1709,20 @@ __trace_add_event_dirs(struct trace_array *tr)
 	}
 }
 
+/* Remove the event directory structure for a trace directory. */
+static void
+__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);
+		kfree(file);
+	}
+}
+
 static void
 __add_event_to_tracers(struct ftrace_event_call *call,
 		       struct ftrace_module_file_ops *file_ops)
@@ -1793,6 +1807,25 @@ int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
 	return 0;
 }
 
+int event_trace_del_tracer(struct trace_array *tr)
+{
+	/* Disable any running events */
+	__ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
+
+	mutex_lock(&event_mutex);
+
+	down_write(&trace_event_mutex);
+	__trace_remove_event_dirs(tr);
+	debugfs_remove_recursive(tr->event_dir);
+	up_write(&trace_event_mutex);
+
+	tr->event_dir = NULL;
+
+	mutex_unlock(&event_mutex);
+
+	return 0;
+}
+
 static __init int event_trace_enable(void)
 {
 	struct trace_array *tr = top_trace_array();