Add ext2 superblock, document file system
diff --git a/include/kernel/dri/fs/ext2/ext2.h b/include/kernel/dri/fs/ext2/ext2.h
index a94fb77..1adf51c 100644
--- a/include/kernel/dri/fs/ext2/ext2.h
+++ b/include/kernel/dri/fs/ext2/ext2.h
@@ -78,4 +78,5 @@
 	EXT2_OS_OTHER_BSD,
 };
 
+struct ext2_superblock ext2_read_superblock();
 void ext2_mount(struct fs_node *where);