diff --git a/fs/udf/super.c b/fs/udf/super.c
index d2ec9f3..441b892 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -135,6 +135,7 @@
 	ei->i_next_alloc_block = 0;
 	ei->i_next_alloc_goal = 0;
 	ei->i_strat4096 = 0;
+	init_rwsem(&ei->i_data_sem);
 
 	return &ei->vfs_inode;
 }