Re: [PATCH v2 16/20] efivarfs: Return an error if we fail to read a variable

[Lingzhu Xiang <lxiang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On 11/02/2012 04:53 PM, Matt Fleming wrote:
> Instead of always returning 0 in efivarfs_file_read(), even when we
> fail to successfully read the variable, convert the EFI status to
> something meaningful and return that to the caller. This way the user
> will have some hint as to why the read failed.
> ...
>
> +	case EFI_NOT_FOUND:
> +		err = -ENOENT;

This will be ambiguous for userspace. Is it file not being found by
efivarfs or by firmware?

Actually I've been confused during testing like this:

# ll test-12341234-1234-1234-1234-123412341234
ls: cannot access test-12341234-1234-1234-1234-123412341234: No such 
file or directory
# echo -en "\0\0\0\0a" >test-12341234-1234-1234-1234-123412341234
-bash: echo: write error: No such file or directory
# ll test-12341234-1234-1234-1234-123412341234
-rw-r--r--. 1 root root 0 Dec 21 06:19 
test-12341234-1234-1234-1234-123412341234


--
Lingzhu Xiang