zdtm: add ability to create an external tasks

It will be used for checking tcp connections, external unix sockets, etc
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm.sh

@@ -231,10 +231,18 @@ EOF
 		diff_fds $ddump/dump.fd $ddump/dump.fd.after || return 1
 		killall -CONT $tname
 	else
-		while :; do
-			killall -9 $tname &> /dev/null || break
-			echo Waiting...
-			sleep 0.1
+		# Wait while tasks are dying, otherwise PIDs would be busy.
+		for i in $ddump/core-*.img; do
+			local pid
+
+			[ -n "$PIDNS" ] && break;
+
+			pid=`expr "$i" : '.*/core-\([0-9]*\).img'`
+			while :; do
+				kill -0 $pid &> /dev/null || break;
+				echo Waiting the process $pid
+				sleep 0.1
+			done
 		done
 
 		echo Restore $PID

test/zdtm/lib/test.c

@@ -89,10 +89,15 @@ static void redir_stdfds()
 		close(nullfd);
 }
 
-void test_init(int argc, char **argv)
+void test_ext_init(int argc, char **argv)
 {
-	extern void parseargs(int, char **);
+	parseargs(argc, argv);
+	if (test_log_init(outfile, ".external"))
+		exit(1);
+}
 
+void test_init(int argc, char **argv)
+{
 	pid_t pid;
 	static FILE *pidf;
 	char *val;

test/zdtm/lib/zdtmtst.h

@@ -4,6 +4,7 @@
 #include <sys/types.h>
 
 /* set up test */
+extern void test_ext_init(int argc, char **argv);
 extern void test_init(int argc, char **argv);
 extern void test_init_ns(int argc, char **argv, unsigned long clone_flags, int (*fn)(int , char **));
 
@@ -62,6 +63,7 @@ extern void __push_opt(struct long_opt *opt);
 #define __param_check(name, p, type) \
 	static inline type *__check_##name(void) { return(p); }
 
+extern void parseargs(int, char **);
 extern int parse_opt_bool(char *param, void *arg);
 #define param_check_bool(name, p) __param_check(name, p, int)
 extern int parse_opt_int(char *param, void *arg);