-extern struct address_space_operations jfs_aops;
-extern struct inode_operations jfs_dir_inode_operations;
-extern struct file_operations jfs_dir_operations;
-extern struct inode_operations jfs_file_inode_operations;
-extern struct file_operations jfs_file_operations;
-extern struct inode_operations jfs_symlink_inode_operations;
+extern const struct address_space_operations jfs_aops;
+extern const struct inode_operations jfs_dir_inode_operations;
+extern const struct file_operations jfs_dir_operations;
+extern const struct inode_operations jfs_file_inode_operations;
+extern const struct file_operations jfs_file_operations;
+extern const struct inode_operations jfs_symlink_inode_operations;