tracing: Add rmdir to remove multibuffer instances
Add a method to the hijacked dentry descriptor of the
"instances" directory to allow for rmdir to remove an
instance of a multibuffer.
Example:
cd /debug/tracing/instances
mkdir hello
ls
hello/
rmdir hello
ls
Like the mkdir method, the i_mutex is dropped for the instances
directory. The instances directory is created at boot up and can
not be renamed or removed. The trace_types_lock mutex is used to
synchronize adding and removing of instances.
I've run several stress tests with different threads trying to
create and delete directories of the same name, and it has stood
up fine.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 883fe0b..b825ea2 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1001,6 +1001,7 @@
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;