extern struct rw_semaphore sysfs_rename_sem;
extern struct super_block * sysfs_sb;
-extern struct file_operations sysfs_dir_operations;
-extern struct file_operations sysfs_file_operations;
-extern struct file_operations bin_fops;
+extern const struct file_operations sysfs_dir_operations;
+extern const struct file_operations sysfs_file_operations;
+extern const struct file_operations bin_fops;
extern struct inode_operations sysfs_dir_inode_operations;
extern struct inode_operations sysfs_symlink_inode_operations;