Re: Re: For the condition "file->f_mode", when it failed, it should return EACCES rather than EBADF.

[majianpeng]

>On Sun, Feb 03 2013, majianpeng wrote:
>> Hi all,
>> 	When I wanted to do discard operations,but i set the  openflag was O_RDONLY,it returned a EBADF rather than EACCES or EPERM.
>> I searched the code and found:
>> >case BLKDISCARD:
>> >case BLKSECDISCARD: {
>> >		uint64_t range[2];
>> 
>> >		if (!(mode & FMODE_WRITE))
>> >			return -EBADF;
>> Initial i thought there was error.But i searched all code of kernel and found some places like this.
>> 
>> The description of EBADF is "Bad file numbe". There are some places where returned EBADF like,
>> >if (!f.file)
>> >		return -EBADF;
>> 
>> So i think for checking file->f_mode when failed, it should return EACCESS.
>
>But that would break the ABI at this point. I agree with you, though,
>EBADF is not the right error for this case.
>
>-- 
>Jens Axboe
>
Sorry, can you explain in detail? Why can it break the ABI ?

Thanks!
Jianpeng Ma韬{.n?????%?lzwm?b?Р骒r?zXЩ??{ay????j?f＂?????ア?⒎?:+v???????赙zZ+????"?!?O???v??m?鹈n?帼Y&—