blktrace: annotate required lock on do_blk_trace_setup()

Ensure it is clear which lock is required on do_blk_trace_setup(). Suggested-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
sparknack · Jun 24, 2020 · a67549c · a67549c
1 parent e8c7d14
commit a67549c
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
@@ -483,6 +483,8 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 	struct dentry *dir = NULL;
 	int ret;
 
+	lockdep_assert_held(&q->blk_trace_mutex);
+
 	if (!buts->buf_size || !buts->buf_nr)
 		return -EINVAL;