diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index a4c8f9d9522e..884333b9fc76 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -535,6 +535,18 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, #endif bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root); + /* + * As blktrace relies on debugfs for its interface the debugfs directory + * is required, contrary to the usual mantra of not checking for debugfs + * files or directories. + */ + if (IS_ERR_OR_NULL(dir)) { + pr_warn("debugfs_dir not present for %s so skipping\n", + buts->name); + ret = -ENOENT; + goto err; + } + bt->dev = dev; atomic_set(&bt->dropped, 0); INIT_LIST_HEAD(&bt->running_list);