不知道从那个版本开始，Kernel/include/linux/fs.h有了修改
struct address_space_operations 内部定义有了变化
造成YAFFS2编译出错。
修改方法：
int (*write_end)(struct file *, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
int (*prepare_write)(struct file *, struct page *, unsigned, unsigned);
int (*commit_write)(struct file *, struct page *, unsigned, unsigned);
/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
增加以上红色部分
