extern struct buffer_head *qnx4_bread(struct inode *, int, int);
-extern struct inode_operations qnx4_file_inode_operations;
-extern struct inode_operations qnx4_dir_inode_operations;
+extern const struct inode_operations qnx4_file_inode_operations;
+extern const struct inode_operations qnx4_dir_inode_operations;
extern const struct file_operations qnx4_file_operations;
extern const struct file_operations qnx4_dir_operations;
extern int qnx4_is_free(struct super_block *sb, long block);