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authorSteven Rostedt <srostedt@redhat.com>2012-08-07 16:14:16 -0400
committerSteven Rostedt <rostedt@goodmis.org>2013-03-15 00:34:45 -0400
commit0c8916c34203734d3b05953ebace52d7c2969f16 (patch)
treef975bab6327e974b9f6a274b2e104b6ddd692f0c /kernel/trace/trace_events.c
parent277ba04461c2746cf935353474c0961161951b68 (diff)
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>
Diffstat (limited to 'kernel/trace/trace_events.c')
-rw-r--r--kernel/trace/trace_events.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 58a61302a733..06d6bc275221 100644
--- a/kernel/trace/trace_events.c
+++ b/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();