1 files changed, 5 insertions, 1 deletions

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index ee7a8bb8b1e8..95f89faca73e 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -426,11 +426,15 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 
         ret = -ENOENT;
 
+        mutex_lock(&blk_tree_mutex);
         if (!blk_tree_root) {
                 blk_tree_root = debugfs_create_dir("block", NULL);
-                if (!blk_tree_root)
+                if (!blk_tree_root) {
+                        mutex_unlock(&blk_tree_mutex);
                         goto err;
+                }
         }
+        mutex_unlock(&blk_tree_mutex);
 
         dir = debugfs_create_dir(buts->name, blk_tree_root);