请教：如果mmap的文件出现IO错误会怎样？？？

icebreaker7

有这么一个文件，通过read/write读写它会出现IO错误（errno为EIO，存储该文件的某些扇区确实已经损坏）。
如果以mmap的方式来操作这个文件，怎么样才能知道访问这个文件的过程中是否出现了IO错误？

我在网上搜索到了一个对该问题的回答：
Sakagami Hiroki wrote:
> Hi,
>
> When I open() a file on the disk and perform read() / write()
> operations on the descriptor, I can detect a physical disk
> I/O error by checking the return code and errno.

If O_SYNC has not been specified while opening the file, the return
code does not tell you if a physical error has occured.

> But when I mmap() a file on the disk and perform memcpy() on
> the mapped area, how do I know whether a disk error occurs?

You'll get a signal. Not sure which, probably SIGSEGV or SIGBUS.

难道现实真的像这位仁兄回复的这么悲惨吗？

chenbin200818

#include <sys/mman.h>

       void *mmap(void *addr, size_t length, int prot, int flags,
                  int fd, off_t offset);
       int munmap(void *addr, size_t length);

   有返回值 自己判断