From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [patch net-next] team: do not use -ENOENT
Date: Thu, 17 Jan 2013 15:42:40 -0500 (EST)
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From: Jiri Pirko <jiri@resnulli.us>
Date: Thu, 17 Jan 2013 21:33:47 +0100

>>> @@ -2320,7 +2320,7 @@ static int team_nl_cmd_options_set(struct sk_buff *skb, struct genl_info *info)
>>>  			list_add(&opt_inst->tmp_list, &opt_inst_list);
>>>  		}
>>>  		if (!opt_found) {
>>> -			err = -ENOENT;
>>> +			err = -EINVAL;
>>>  			goto team_put;
>>>  		}
>>>  	}


> I'm not really sure. But in this case, I do not think that is a problem.
> 
> 1) I'm most probably the only one (libteam) who is using this api and
> libteam does not mind about what err code is returned in these cases.
> 
> 2) In this case, it is only about different number. And one number or
> another, it does not imply userspace to behave differently. In other words,
> userspace should not take different actions in case for example -ENOENT
> or -ENODEV is returned.

I agree with this analysis.

But for the team_nl_cmd_options_set() case, I would strongly advise
that you use some error code more descriptive than -EINVAL.  In fact
the existing -ENOENT I feel is better, because it tells the caller
what kind of problem there was.

Even if you don't like the fact that -ENOENT is oriented towards file
existence, it does convey a ton more information than -EINVAL does.