zdtm/mnt_ext_auto: add different bind-mounts of external mount

Before dump:

438 437 0:51 /mtest /zdtm/static/mnt_ext_manual.test rw,relatime - tmpfs zdtm_auto_ext_mnt rw
439 437 0:51 /mtest /zdtm/static/mnt_ext_manual_private_shared_bind.test rw,relatime shared:144 - tmpfs zdtm_auto_ext_mnt rw
440 437 0:51 /mtest /zdtm/static/mnt_ext_manual_bind.test rw,relatime shared:144 - tmpfs zdtm_auto_ext_mnt rw
441 437 0:51 /mtest /zdtm/static/mnt_ext_manual_slave_shared_bind.test rw,relatime shared:145 master:144 - tmpfs zdtm_auto_ext_mnt rw
442 437 0:51 /mtest /zdtm/static/mnt_ext_manual_slave_bind.test rw,relatime master:145 - tmpfs zdtm_auto_ext_mnt rw

>From log: mount mnt_ext_manual_slave_bind is restored as slave of
mnt_ext_manual_slave_shared_bind, which is restored as slave of
mnt_ext_manual_private_shared_bind, which is restored as shared of
mnt_ext_manual_bind, which is restored as private bind of external,
that is exactly the same way mnt_is_external() looks for external.

v2: fix test to cover all cases in mnt_is_external()
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

test/zdtm/static/mnt_ext_auto.c

@@ -16,9 +16,17 @@ const char *test_author	= "Andrew Vagin <avagin@gmail.com>";
 
 #ifdef ZDTM_EXTMAP_MANUAL
 char *dirname = "mnt_ext_manual.test";
+char *dirname_private_shared_bind = "mnt_ext_manual_private_shared_bind.test";
+char *dirname_bind = "mnt_ext_manual_bind.test";
+char *dirname_slave_shared_bind = "mnt_ext_manual_slave_shared_bind.test";
+char *dirname_slave_bind = "mnt_ext_manual_slave_bind.test";
 #define DDIR	"mtest"
 #else
 char *dirname = "mnt_ext_auto.test";
+char *dirname_private_shared_bind = "mnt_ext_auto_private_shared_bind.test";
+char *dirname_bind = "mnt_ext_auto_bind.test";
+char *dirname_slave_shared_bind = "mnt_ext_auto_slave_shared_bind.test";
+char *dirname_slave_bind = "mnt_ext_auto_slave_bind.test";
 #define DDIR	"atest"
 #endif
 TEST_OPTION(dirname, string, "directory name", 1);
@@ -26,8 +34,10 @@ TEST_OPTION(dirname, string, "directory name", 1);
 int main(int argc, char ** argv)
 {
 	char src[PATH_MAX], dst[PATH_MAX], *root;
+	char dst_bind[PATH_MAX], dst_private_shared_bind[PATH_MAX],
+		dst_slave_shared_bind[PATH_MAX], dst_slave_bind[PATH_MAX];
 	char *dname = "/tmp/zdtm_ext_auto.XXXXXX";
-	struct stat sta, stb;
+	struct stat sta, stb, bsta, bstb, ssbsta, sbsta, ssbstb, sbstb, psbsta, psbstb;
 	char* zdtm_newns = getenv("ZDTM_NEWNS");
 
 	root = getenv("ZDTM_ROOT");
@@ -37,6 +47,10 @@ int main(int argc, char ** argv)
 	}
 
 	sprintf(dst, "%s/%s", get_current_dir_name(), dirname);
+	sprintf(dst_private_shared_bind, "%s/%s", get_current_dir_name(), dirname_private_shared_bind);
+	sprintf(dst_bind, "%s/%s", get_current_dir_name(), dirname_bind);
+	sprintf(dst_slave_shared_bind, "%s/%s", get_current_dir_name(), dirname_slave_shared_bind);
+	sprintf(dst_slave_bind, "%s/%s", get_current_dir_name(), dirname_slave_bind);
 
 	if (!zdtm_newns) {
 		pr_perror("ZDTM_NEWNS is not set");
@@ -59,6 +73,46 @@ int main(int argc, char ** argv)
 		pr_perror("bind");
 		return 1;
 	}
+	mkdir(dst_private_shared_bind, 755);
+	if (mount(dst, dst_private_shared_bind, NULL, MS_BIND, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
+	if (mount("none", dst_private_shared_bind, NULL, MS_PRIVATE, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
+	if (mount("none", dst_private_shared_bind, NULL, MS_SHARED, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
+	mkdir(dst_bind, 755);
+	if (mount(dst_private_shared_bind, dst_bind, NULL, MS_BIND, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
+	mkdir(dst_slave_shared_bind, 755);
+	if (mount(dst_bind, dst_slave_shared_bind, NULL, MS_BIND, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
+	if (mount("none", dst_slave_shared_bind, NULL, MS_SLAVE, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
+	if (mount("none", dst_slave_shared_bind, NULL, MS_SHARED, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
+	mkdir(dst_slave_bind, 755);
+	if (mount(dst_slave_shared_bind, dst_slave_bind, NULL, MS_BIND, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
+	if (mount("none", dst_slave_bind, NULL, MS_SLAVE, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
 test:
 	test_init(argc, argv);
 
@@ -67,18 +121,76 @@ test:
 		sleep(100);
 		return 1;
 	}
+	if (stat(dirname_private_shared_bind, &psbstb)) {
+		pr_perror("stat");
+		sleep(100);
+		return 1;
+	}
+	if (stat(dirname_bind, &bstb)) {
+		pr_perror("stat");
+		sleep(100);
+		return 1;
+	}
+	if (stat(dirname_slave_shared_bind, &ssbstb)) {
+		pr_perror("stat");
+		sleep(100);
+		return 1;
+	}
+	if (stat(dirname_slave_bind, &sbstb)) {
+		pr_perror("stat");
+		sleep(100);
+		return 1;
+	}
 
 	test_daemon();
 	test_waitsig();
 
 	if (stat(dirname, &sta)) {
 		pr_perror("stat");
+		sleep(100);
+		return 1;
+	}
+	if (stat(dirname_private_shared_bind, &psbsta)) {
+		pr_perror("stat");
+		sleep(100);
+		return 1;
+	}
+	if (stat(dirname_bind, &bsta)) {
+		pr_perror("stat");
+		sleep(100);
+		return 1;
+	}
+	if (stat(dirname_slave_shared_bind, &ssbsta)) {
+		pr_perror("stat");
+		sleep(100);
+		return 1;
+	}
+	if (stat(dirname_slave_bind, &sbsta)) {
+		pr_perror("stat");
+		sleep(100);
 		return 1;
 	}
+
 	if (sta.st_dev != stb.st_dev) {
 		fail();
 		return 1;
 	}
+	if (psbsta.st_dev != psbstb.st_dev) {
+		fail();
+		return 1;
+	}
+	if (bsta.st_dev != bstb.st_dev) {
+		fail();
+		return 1;
+	}
+	if (ssbsta.st_dev != ssbstb.st_dev) {
+		fail();
+		return 1;
+	}
+	if (sbsta.st_dev != sbstb.st_dev) {
+		fail();
+		return 1;
+	}
 
 	pass();