zdtm: check read-only bind mounts

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

test/zdtm.sh

@@ -189,6 +189,7 @@ generate_test_list()
 		ns/static/session00
 		ns/static/session01
 		ns/static/tempfs
+		ns/static/mnt_ro_bind
 		ns/static/mount_paths
 		ns/static/bind-mount
 		static/utsname
@@ -328,9 +329,9 @@ chroot-file
 console
 vt
 rtc
-tempfs
 maps007
 tempfs
+mnt_ro_bind
 bind-mount
 mountpoints
 inotify_irmap

test/zdtm/live/static/Makefile

@@ -183,6 +183,7 @@ TST_DIR		=				\
 		overmount_fifo			\
 		overmount_sock			\
 		tempfs				\
+		mnt_ro_bind			\
 		mount_paths			\
 		bind-mount			\
 		inotify00			\

test/zdtm/live/static/mnt_ro_bind.c

+#include <stdbool.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <linux/limits.h>
+#include <errno.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc	= "Check read-only bind-mounts";
+const char *test_author	= "Andrew Vagin <avagin@openvz.org>";
+
+char *dirname;
+TEST_OPTION(dirname, string, "directory name", 1);
+
+#define TEST_WORD	"testtest"
+#define TEST_WORD2	"TESTTEST"
+
+int main(int argc, char **argv)
+{
+	int fd, ret = 1;
+	char rw_path[PATH_MAX], ro_path[PATH_MAX], rw_f[PATH_MAX], ro_f[PATH_MAX];
+
+	test_init(argc, argv);
+
+	snprintf(rw_path, sizeof(rw_path), "%s/rw", dirname);
+	snprintf(ro_path, sizeof(ro_path), "%s/ro", dirname);
+	snprintf(rw_f, sizeof(rw_f), "%s/rw/test", dirname);
+	snprintf(ro_f, sizeof(ro_f), "%s/ro/test", dirname);
+
+	mkdir(dirname, 0700);
+	if (mount("none", dirname, "tmpfs", 0, "") < 0) {
+		fail("Can't mount tmpfs");
+		return 1;
+	}
+	mkdir(rw_path, 0700);
+	mkdir(ro_path, 0700);
+
+	if (mount("zdtm_rw", rw_path, "tmpfs", 0, "") < 0) {
+		fail("Can't mount tmpfs");
+		return 1;
+	}
+
+	if (mount(rw_path, ro_path, NULL, MS_BIND, NULL) < 0) {
+		fail("Can't mount tmpfs");
+		return 1;
+	}
+
+	if (mount(NULL, ro_path, NULL, MS_BIND | MS_REMOUNT | MS_RDONLY, NULL) < 0) {
+		fail("Can't mount tmpfs");
+		return 1;
+	}
+
+	test_daemon();
+	test_waitsig();
+
+	fd = open(ro_f, O_CREAT | O_WRONLY, 0666);
+	if (fd != -1 || errno != EROFS) {
+		fail("%s is created", ro_f);
+		goto err;
+	}
+
+	fd = open(rw_f, O_CREAT | O_WRONLY, 0666);
+	if (fd < 0) {
+		fail("Unable to create %s", rw_f);
+		goto err;
+	}
+	close(fd);
+
+	fd = open(ro_f, O_RDONLY);
+	if (fd < 0) {
+		fail("Unable to create %s", rw_f);
+		goto err;
+	}
+
+	pass();
+	ret = 0;
+err:
+	umount2(dirname, MNT_DETACH);
+	rmdir(dirname);
+	return ret;
+}