tests: add a test for --cgroup-root

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm.sh

@@ -173,6 +173,7 @@ static/netns-nf
 static/netns
 static/cgroup00
 static/cgroup01
+static/cgroup02
 ns/static/clean_mntns
 "
 
@@ -218,6 +219,7 @@ mountpoints
 inotify_irmap
 cgroup00
 cgroup01
+cgroup02
 clean_mntns
 deleted_dev
 mntns_open

test/zdtm/live/static/Makefile

@@ -165,6 +165,7 @@ TST_DIR		=				\
 		cgroup00			\
 		rmdir_open			\
 		cgroup01			\
+		cgroup02			\
 		mntns_open			\
 		mntns_link_remap		\
 		mntns_link_ghost		\

test/zdtm/live/static/cgroup02.c

+#include <unistd.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/mount.h>
+#include "zdtmtst.h"
+
+const char *test_doc	= "Check that empty cgroups are preserved";
+const char *test_author	= "Tycho Andersen <tycho.andersen@canonical.com>";
+
+char *dirname;
+TEST_OPTION(dirname, string, "cgroup directory name", 1);
+static const char *cgname = "zdtmtst";
+static const char *subname = "oldroot";
+static const char *cgname2 = "defaultroot";
+
+int mount_and_add(const char *controller, const char *path)
+{
+	char aux[1024], paux[1024], subdir[1024];
+	int cgfd, l;
+
+	if (mkdir(dirname, 0700) < 0 && errno != EEXIST) {
+		err("Can't make dir");
+		return -1;
+	}
+
+	sprintf(subdir, "%s/%s", dirname, controller);
+	if (mkdir(subdir, 0700) < 0) {
+		err("Can't make dir");
+		return -1;
+	}
+
+	sprintf(aux, "none,name=%s", controller);
+	if (mount("none", subdir, "cgroup", 0, aux)) {
+		err("Can't mount cgroups");
+		goto err_rd;
+	}
+
+	sprintf(paux, "%s/%s", subdir, path);
+	mkdir(paux, 0600);
+
+	l = sprintf(aux, "%d", getpid());
+	sprintf(paux, "%s/%s/tasks", subdir, path);
+
+	cgfd = open(paux, O_WRONLY);
+	if (cgfd < 0) {
+		err("Can't open tasks");
+		goto err_rs;
+	}
+
+	l = write(cgfd, aux, l);
+	close(cgfd);
+
+	if (l < 0) {
+		err("Can't move self to subcg");
+		goto err_rs;
+	}
+
+	return 0;
+err_rs:
+	umount(dirname);
+err_rd:
+	rmdir(dirname);
+	return -1;
+}
+
+bool test_exists(char *mountinfo_line, char *path)
+{
+	char aux[1024], paux[1024];
+	struct stat st;
+
+	sscanf(mountinfo_line, "%*d %*d %*d:%*d %*s %s", aux);
+	test_msg("found cgroup at %s\n", aux);
+
+	sprintf(paux, "%s/%s", aux, path);
+	if (stat(paux, &st)) {
+		return false;
+	}
+
+	if (!S_ISDIR(st.st_mode)) {
+		return false;
+	}
+
+	return true;
+}
+
+int main(int argc, char **argv)
+{
+	FILE *cgf;
+	bool found_zdtmtstroot = false, found_newroot = false;
+	char paux[1024];
+	int ret = -1;
+
+	test_init(argc, argv);
+
+	if (mount_and_add(cgname, subname))
+		goto out;
+	if (mount_and_add(cgname2, subname)) {
+		sprintf(paux, "%s/%s", dirname, cgname);
+		umount(paux);
+		rmdir(paux);
+		goto out;
+	}
+
+	test_daemon();
+	test_waitsig();
+
+	cgf = fopen("/proc/self/mountinfo", "r");
+	if (cgf == NULL) {
+		fail("No mountinfo file");
+		goto out_umount;
+	}
+
+	while (fgets(paux, sizeof(paux), cgf)) {
+		char *s;
+
+		s = strstr(paux, cgname);
+		if (s && test_exists(paux, "zdtmtstroot")) {
+			found_zdtmtstroot = true;
+		}
+
+		s = strstr(paux, cgname2);
+		if (s && test_exists(paux, "newroot")) {
+			found_newroot = true;
+		}
+	}
+
+	if (!found_zdtmtstroot) {
+		fail("oldroot not rewritten to zdtmtstroot!\n");
+		goto out_close;
+	}
+
+	if (!found_newroot) {
+		fail("oldroot not rewritten to newroot!\n");
+		goto out_close;
+	}
+
+	pass();
+	ret = 0;
+
+
+out_close:
+	fclose(cgf);
+out_umount:
+	sprintf(paux, "%s/%s", dirname, cgname);
+	umount(paux);
+	rmdir(paux);
+
+	sprintf(paux, "%s/%s", dirname, cgname2);
+	umount(paux);
+	rmdir(paux);
+out:
+	return ret;
+}

test/zdtm/live/static/cgroup02.hook

+#!/bin/bash
+
+set -e
+
+rmroots() {
+	echo "Cleaning $tname"
+
+	set +e
+	rmdir "$tname/oldroot"
+	rmdir "$tname/newroot"
+	rmdir "$tname/zdtmtstroot"
+	set -e
+
+	echo "Left there is:"
+	ls "$tname"
+	umount "$tname"
+	rmdir "$tname"
+}
+
+tname=$(mktemp -d cgclean.XXXXXX)
+mount -t cgroup none $tname -o "none,name=zdtmtst"
+rmroots
+
+tname=$(mktemp -d cgclean.XXXXXX)
+mount -t cgroup none $tname -o "none,name=defaultroot"
+rmroots
+

test/zdtm/live/static/cgroup02.opts

+--manage-cgroups --cgroup-root /newroot --cgroup-root name=zdtmtst:/zdtmtstroot