[CRIU] [PATCH 2/2]v2 service: add support for check request

[Ruslan Kuprieiev]

On 19.11.2013 12:10, Pavel Emelyanov wrote:
> On 11/19/2013 03:44 PM, Ruslan Kuprieiev wrote:
>> On 19.11.2013 11:36, Pavel Emelyanov wrote:
>>> On 11/18/2013 06:25 PM, Ruslan Kuprieiev wrote:
>>>> Signed-off-by: Ruslan Kuprieiev <kupruser at gmail.com>
>>>> ---
>>>>    cr-service.c | 37 +++++++++++++++++++++++++++++++++++++
>>>>    1 file changed, 37 insertions(+)
>>>>
>>>> diff --git a/cr-service.c b/cr-service.c
>>>> index 65710fd..c337fce 100644
>>>> --- a/cr-service.c
>>>> +++ b/cr-service.c
>>>> @@ -217,6 +217,41 @@ exit:
>>>>    	return success ? 0 : 1;
>>>>    }
>>>>    
>>>> +/*
>>>> + * Only checks criu ability to work in this enviroment.
>>>> + */
>>>> +static int check_using_req(int sk, CriuOpts *req)
>>>> +{
>>>> +	bool success = false;
>>>> +	CriuResp msg = CRIU_RESP__INIT;
>>>> +	CriuCheckResp resp = CRIU_CHECK_RESP__INIT;
>>>> +
>>>> +	if (setup_opts_from_req(sk, req) == -1) {
>>>> +		pr_perror("Arguments treating fail");
>>>> +		goto exit;
>>>> +	}
>>>> +
>>>> +	if (cr_check() < 0) {
>>>> +		pr_perror("The kernel support isn't up-to-date");
>>>> +		goto exit;
>>>> +	}
>>>> +
>>>> +	resp.kernel = true;
>>> Always true argument is pointless.
>> But resp.kernel = false after init. If cr_check() does not fail, we set
>> resp.kernel to true, and if cr_check() does fail - resp.kernel = false.
> So we have two types of responses:
>
> * kernel = true,  success = true  for OK
> * kernel = false, success = false for not-OK
>
> Why is just success = <success-or-not> not enough?
Here is what we've got:

-- resp.success == false  -- options are wrong or something bad happened 
and check wasn't done

-- resp.success == true and resp.check.kernel == true -- check was done 
and kernel features are ok

-- resp.success == true and resp.check.kernel == false -- check was done 
and kernel features are not ok

And also we may easily add some more fields for more complete system 
state analysis.

>>>> +
>>>> +	success = true;
>>>> +exit:
>>>> +	msg.type = CRIU_REQ_TYPE__CHECK;
>>>> +	msg.success = success;
>>>> +	msg.check = &resp;
>>>> +
>>>> +	if (send_criu_msg(sk, &msg) == -1) {
>>>> +		pr_perror("Can't send response");
>>>> +		success = false;
>>>> +	}
>>>> +
>>>> +	return success ? 0 : 1;
>>>> +}
>>>> +
>>>>    static int cr_service_work(int sk)
>>>>    {
>>>>    	CriuReq *msg = 0;
>>>> @@ -233,6 +268,8 @@ static int cr_service_work(int sk)
>>>>    		return dump_using_req(sk, msg->opts);
>>>>    	case CRIU_REQ_TYPE__RESTORE:
>>>>    		return restore_using_req(sk, msg->opts);
>>>> +	case CRIU_REQ_TYPE__CHECK:
>>>> +		return check_using_req(sk, msg->opts);
>>>>    
>>>>    	default: {
>>>>    		CriuResp resp = CRIU_RESP__INIT;
>>>>
>> .
>>
>