[CRIU] Re: [PATCH cr 04/10] restore: add interface for creating helper tasks (v2)

[Pavel Emelyanov]

> @@ -341,8 +341,28 @@ err:
>  
>  static int restore_one_alive_task(int pid)
>  {
> +	struct pstree_item *pi;
>  	pr_info("Restoring resources\n");
>  
> +	list_for_each_entry(pi, &me->children, list) {
> +		int status, ret;
> +
> +		if (pi->state != TASK_HELPER)
> +			continue;
> +
> +		ret = waitpid(pi->pid, &status, 0);
> +		if (ret == -1) {
> +			pr_err("waitpid(%d) failed\n", pi->pid);
> +			return -1;
> +		}
> +
> +		if (!WIFEXITED(status) || WEXITSTATUS(status)) {
> +			pr_err("%d exited with non-zero code (%d,%d)", pi->pid,
> +				WEXITSTATUS(status), WTERMSIG(status));
> +			return -1;
> +		}
> +	}

Plz put this into a helper fn with a comment about why we do it.

> +
>  	if (prepare_fds(me))
>  		return -1;
>  

> @@ -557,6 +587,16 @@ err:
>  
>  static void sigchld_handler(int signal, siginfo_t *siginfo, void *data)
>  {
> +	struct pstree_item *pi;
> +
> +	if (me)
> +		list_for_each_entry(pi, &me->children, list) {
> +			if (pi->state != TASK_HELPER)
> +				continue;
> +			if (pi->pid == siginfo->si_pid)
> +				return;
> +		}

Same here -- move to a helper with a comment.

> +
>  	if (siginfo->si_code & CLD_EXITED)
>  		pr_err("%d exited, status=%d\n",
>  			siginfo->si_pid, siginfo->si_status);
> @@ -704,7 +744,7 @@ static int restore_root_task(struct pstree_item *init, struct cr_options *opts)
>  		return -1;
>  	}
>  
> -	act.sa_flags |= SA_NOCLDWAIT | SA_NOCLDSTOP | SA_SIGINFO | SA_RESTART;
> +	act.sa_flags |= SA_NOCLDSTOP | SA_SIGINFO | SA_RESTART;

Plz, explain this hunk.

>  	act.sa_sigaction = sigchld_handler;
>  	ret = sigaction(SIGCHLD, &act, &old_act);
>  	if (ret < 0) {