eventfs: Use eventfs_remove_events_dir()

The update to removing the eventfs_file changed the way the events top
level directory was handled. Instead of returning a dentry, it now returns
the eventfs_inode. In this changed, the removing of the events top level
directory is not much different than removing any of the other
directories. Because of this, the removal just called eventfs_remove_dir()
instead of eventfs_remove_events_dir().

Although eventfs_remove_dir() does the clean up, it misses out on the
dget() of the ei->dentry done in eventfs_create_events_dir(). It makes
more sense to match eventfs_create_events_dir() with a specific function
eventfs_remove_events_dir() and this specific function can then perform
the dput() to the dentry that had the dget() when it was created.

Fixes: 5790b1f ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310051743.y9EobbUr-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Author: rostedt

fs/tracefs/event_inode.c

@@ -901,22 +901,17 @@ void eventfs_remove_dir(struct eventfs_inode *ei)
 }
 
 /**
- * eventfs_remove_events_dir - remove eventfs dir or file from list
- * @dentry: events's dentry to be removed.
+ * eventfs_remove_events_dir - remove the top level eventfs directory
+ * @ei: the event_inode returned by eventfs_create_events_dir().
  *
- * This function remove events main directory
+ * This function removes the events main directory
  */
-void eventfs_remove_events_dir(struct dentry *dentry)
+void eventfs_remove_events_dir(struct eventfs_inode *ei)
 {
-	struct tracefs_inode *ti;
-
-	if (!dentry || !dentry->d_inode)
-		return;
+	struct dentry *dentry = ei->dentry;
 
-	ti = get_tracefs(dentry->d_inode);
-	if (!ti || !(ti->flags & TRACEFS_EVENT_INODE))
-		return;
+	eventfs_remove_dir(ei);
 
-	d_invalidate(dentry);
+	/* Matches the dget() from eventfs_create_events_dir() */
 	dput(dentry);
 }

include/linux/tracefs.h

@@ -41,6 +41,7 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode
 					 const struct eventfs_entry *entries,
 					 int size, void *data);
 
+void eventfs_remove_events_dir(struct eventfs_inode *ei);
 void eventfs_remove_dir(struct eventfs_inode *ei);
 
 struct dentry *tracefs_create_file(const char *name, umode_t mode,

kernel/trace/trace_events.c

@@ -3872,7 +3872,7 @@ int event_trace_del_tracer(struct trace_array *tr)
 
 	down_write(&trace_event_sem);
 	__trace_remove_event_dirs(tr);
-	eventfs_remove_dir(tr->event_dir);
+	eventfs_remove_events_dir(tr->event_dir);
 	up_write(&trace_event_sem);
 
 	tr->event_dir = NULL;