1 files changed, 194 insertions, 0 deletions

diff --git a/test/zdtm/static/mnt_ext_collision.c b/test/zdtm/static/mnt_ext_collision.c
new file mode 100644
index 000000000..324a3484c
--- /dev/null
+++ b/test/zdtm/static/mnt_ext_collision.c
@@ -0,0 +1,194 @@
+#include <sched.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <linux/limits.h>
+
+#include "zdtmtst.h"
+#include "lock.h"
+
+const char *test_doc = "Check external mount mountpoint collide with different mount in nested mntns";
+const char *test_author = "Pavel Tikhomirov <ptikhomirov@virtuozzo.com>";
+
+char *dirname = "mnt_ext_collision.test";
+TEST_OPTION(dirname, string, "directory name", 1);
+
+char *source = "zdtm_ext_collision";
+char *source2 = "zdtm_ext_collision_2";
+
+enum {
+	TEST_INIT = 0,
+	TEST_CHILD,
+	TEST_CHECK,
+	TEST_EXIT,
+	EMERGENCY_ABORT,
+};
+
+futex_t *futex;
+
+#define BUF_SIZE 4096
+
+static int child(void)
+{
+	char dst[PATH_MAX], dst_file[PATH_MAX];
+	int fd;
+
+	if (unshare(CLONE_NEWNS)) {
+		pr_perror("unshare");
+		goto err;
+	}
+
+	/*
+	 * Umount external mount copy
+	 */
+	sprintf(dst, "/%s/dst", dirname);
+	if (umount(dst)) {
+		pr_perror("umount");
+		goto err;
+	}
+
+	/*
+	 * Mount tmpfs in its place
+	 */
+	if (mount(source2, dst, "tmpfs", 0, NULL)) {
+		pr_perror("mount tmpfs");
+		goto err;
+	}
+
+	sprintf(dst_file, "/%s/dst/file", dirname);
+	fd = open(dst_file, O_RDWR | O_CREAT | O_EXCL, 0666);
+	if (fd < 0) {
+		pr_perror("open");
+		goto err;
+	}
+	close(fd);
+
+	futex_set_and_wake(futex, TEST_CHILD);
+	futex_wait_while_lt(futex, TEST_CHECK);
+
+	if (access(dst_file, F_OK)) {
+		pr_perror("access");
+		goto err;
+	}
+
+	futex_set_and_wake(futex, TEST_EXIT);
+	return 0;
+err:
+	futex_set_and_wake(futex, EMERGENCY_ABORT);
+	return 1;
+}
+
+int main(int argc, char **argv)
+{
+	char *root, testdir[PATH_MAX];
+	char lckd[PATH_MAX], dst[PATH_MAX];
+	char *tmp = "/tmp/zdtm_ext_collision.tmp";
+	char *zdtm_newns = getenv("ZDTM_NEWNS");
+	int pid;
+
+	root = getenv("ZDTM_ROOT");
+	if (root == NULL) {
+		pr_perror("root");
+		return 1;
+	}
+
+	if (!zdtm_newns) {
+		pr_perror("ZDTM_NEWNS is not set");
+		return 1;
+	} else if (strcmp(zdtm_newns, "1")) {
+		goto test;
+	}
+
+	/* Prepare directories in test root */
+	sprintf(testdir, "%s/%s", root, dirname);
+	mkdir(testdir, 0755);
+
+	sprintf(lckd, "%s/%s/lckd", root, dirname);
+	mkdir(lckd, 0755);
+	sprintf(dst, "%s/%s/dst", root, dirname);
+	mkdir(dst, 0755);
+
+	/* Prepare mount in criu root */
+	mkdir(tmp, 0755);
+	if (mount(source, tmp, "tmpfs", 0, NULL)) {
+		pr_perror("mount tmpfs");
+		return 1;
+	}
+	if (mount(NULL, tmp, NULL, MS_PRIVATE, NULL)) {
+		pr_perror("make private");
+		return 1;
+	}
+
+	/*
+	 * Create temporary mntns, next mounts will not show up in criu mntns
+	 */
+	if (unshare(CLONE_NEWNS)) {
+		pr_perror("unshare");
+		return 1;
+	}
+
+	/*
+	 * Populate external mount to the tests mntns root
+	 * (in uns flavour this would become locked)
+	 */
+	if (mount(tmp, lckd, NULL, MS_BIND, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
+test:
+	test_init(argc, argv);
+
+	/*
+	 * Hack to create unlocked external mount without pivot_root+bind thing
+	 */
+	sprintf(lckd, "/%s/lckd", dirname);
+	sprintf(dst, "/%s/dst", dirname);
+	if (mount(lckd, dst, NULL, MS_BIND, NULL)) {
+		pr_perror("bind");
+		return 1;
+	}
+
+	/*
+	 * Setup futex for processes syncronization
+	 */
+	futex = mmap(NULL, sizeof(futex), PROT_WRITE | PROT_READ, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+	if (futex == MAP_FAILED) {
+		pr_perror("mmap");
+		return 1;
+	}
+	futex_init(futex);
+
+	/*
+	 * Fork child which would have nested mntns
+	 */
+	pid = fork();
+	if (pid < 0) {
+		pr_perror("fork");
+		return 1;
+	} else if (pid == 0) {
+		exit(child());
+	}
+
+	futex_wait_while_lt(futex, TEST_CHILD);
+	if (futex_get(futex) == EMERGENCY_ABORT) {
+		pr_err("Fail in child\n");
+		return 1;
+	}
+
+	test_daemon();
+	test_waitsig();
+
+	futex_set_and_wake(futex, TEST_CHECK);
+	futex_wait_while_lt(futex, TEST_EXIT);
+	if (futex_get(futex) == EMERGENCY_ABORT) {
+		fail("Fail in child on check stage");
+		return 1;
+	}
+
+	waitpid(pid, NULL, 0);
+	pass();
+	return 0;
+}