Re: [PATCH] io/attr.c: Disallow specifying both -D and -R options for chattr command

[Xiao Yang <yangx.jy@cn.fujitsu.com>]

On 2020/7/24 6:15, Eric Sandeen wrote:
> On 7/22/20 11:39 PM, Xiao Yang wrote:
>> On 2020/7/23 14:08, Christoph Hellwig wrote:
>>> On Thu, Jul 23, 2020 at 01:27:23PM +0800, Xiao Yang wrote:
>>>> -D and -R options are mutually exclusive actually but chattr command
>>>> doesn't check it so that always applies -D option when both of them
>>>> are specified.  For example:
>>> Looks good,
>>>
>>> Reviewed-by: Christoph Hellwig<hch@lst.de>
>> Hi,
>>
>> Ah,  I have a question after sending the patch:
>> Other commands(e.g. cowextsize) including the same options seem to avoid the issue by accepting the last option, as below:
>> --------------------------------------------------------
>> io/cowextsize.c
>> 141         while ((c = getopt(argc, argv, "DR")) != EOF) {
>> 142                 switch (c) {
>> 143                 case 'D':
>> 144                         recurse_all = 0;
>> 145                         recurse_dir = 1;
>> 146                         break;
>> 147                 case 'R':
>> 148                         recurse_all = 1;
>> 149                         recurse_dir = 0;
>> 150                         break;
> Yep, I meant to look at this but hadn't gotten to it yet.  These should all
> be consistent, and I tend to agree with Dave that explicitly conflicting
> incompatible options and erroring out is better than silently accepting
> the last one specified.
>
> And indeed help specifies that they are exclusive:
>
>          cowextsize_cmd.args = _("[-D | -R] [cowextsize]");
>
> It'd be great if you want to send a V2 that makes the behavior (and
> documentation) of any/all commands that accept [-D | -R] consistent.
Hi Eric, Dave

Thanks for your suggestions.
I will send v2 patch to make the behavior consistent.

Thanks,
Xiao Yang
> Thanks,
> -Eric
>
>
> .
>