zdtm: check unshared descriptors for one end of a pipe

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm/live/static/Makefile

@@ -39,6 +39,7 @@ TST_NOFILE	=				\
 		ptrace_sig			\
 		pipe00				\
 		pipe01				\
+		pipe02				\
 		pthread00			\
 		pthread01			\
 		vdso00				\

test/zdtm/live/static/pipe02.c

+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <linux/limits.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc	= "Create two unshared descriptor for the one end of a pipe";
+const char *test_author	= "Andrey Vagin <avagin@parallels.com>";
+
+int main(int argc, char ** argv)
+{
+	int p[2], fd;
+	int ret;
+	char path[PATH_MAX];
+	int flags;
+
+	test_init(argc, argv);
+
+	ret = pipe(p);
+	if (ret)
+		return 1;
+
+	snprintf(path, sizeof(path), "/proc/self/fd/%d", p[0]);
+
+	fd = open(path, O_RDONLY);
+	if (fd == -1) {
+		err("open");
+		return 1;
+	};
+
+	if (fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK) == -1) {
+		err("fcntl");
+		return 1;
+	}
+
+	test_daemon();
+
+	test_waitsig();
+
+	flags = fcntl(fd, F_GETFL, 0);
+	if ((flags & O_NONBLOCK) == 0) {
+		fail("O_NONBLOCK are not restored for %d", fd);
+		return 1;
+	}
+
+	flags = fcntl(p[0], F_GETFL, 0);
+	if ((flags & O_NONBLOCK) != 0) {
+		fail("Unexpected O_NONBLOCK on %d", p[0]);
+		return 1;
+	}
+
+	pass();
+
+	return 0;
+}