Re: [Patch] tools/libxc: Correct read_exact() error messages

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 08/01/14 14:20, Ian Campbell wrote:
> On Tue, 2014-01-07 at 10:04 +0000, Andrew Cooper wrote:
>> The errors have been incorrectly identifying their function since c/s
>> 861aef6e1558bebad8fc60c1c723f0706fd3ed87 which did a lot of error handling
>> cleanup.
>>
>> Use __func__ to ensure the name remains correct in the future.
>>
>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
>> CC: Ian Campbell <Ian.Campbell@citrix.com>
>> CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
> A simple string change seems harmless from a release PoV, so on that
> front 
> Release-Acked-by: Ian Campbell.
>
> For the actual change though, most uses of ERROR in this function just
> have a descriptive error without the function name. If we are going to
> change it then I'm not convinced "rdexact failed..." is as useful as
> something like "Failed to read exactly %d bytes (select returned...)".
> Other thoughts?
>
> (that said, I'm still somewhat inclined to just bung this one in...)
>
> Ian.

When triaging problems after-the-fact from logfiles along, a lack of
file/line/function references is often makes debugging harder than it
should be.

In the specific case I encountered, the error as was sufficed for
working out what had gone wrong (an -EIO).

I would possibly throw it straight in now, with a note that there needs
to be some consistency applied to the error reporting in this and other
areas of libxc.

~Andrew