zdtm: add a new test to check ghost files in a non-root mntns

Signed-off-by: Andrew Vagin <avagin@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

test/zdtm/static/Makefile

@@ -224,6 +224,7 @@ TST_DIR		=				\
 		unlink_fstat04			\
 		mntns_open			\
 		mntns_link_remap		\
+		mntns_ghost			\
 		mntns_link_ghost		\
 		mntns_shared_bind		\
 		mntns_shared_bind02		\

test/zdtm/static/mntns_ghost.c

+#define _GNU_SOURCE
+#include <stdbool.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sched.h>
+#include <sys/wait.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <sys/mount.h>
+#include <dirent.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc	= "Check ghost and link-remap files in a few mntns";
+const char *test_author	= "Andrew Vagin <avagin@parallels.com>";
+
+char *dirname;
+TEST_OPTION(dirname, string, "directory name", 1);
+
+
+int main(int argc, char **argv)
+{
+	task_waiter_t lock;
+	pid_t pid = -1;
+	int status = 1;
+
+	task_waiter_init(&lock);
+	test_init(argc, argv);
+
+	pid = fork();
+	if (pid < 0) {
+		pr_perror("fork");
+		return 1;
+	}
+
+	if (pid == 0) {
+		int fd;
+		DIR *d;
+		struct dirent *de;
+
+		if (unshare(CLONE_NEWNS)) {
+			pr_perror("unshare");
+			return 1;
+		}
+		if (mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL)) {
+			pr_perror("mount");
+			return 1;
+		}
+
+		if (mkdir(dirname, 0600) < 0) {
+			pr_perror("mkdir");
+			return 1;
+		}
+
+		if (mount(dirname, dirname, NULL, MS_BIND, NULL)) {
+			pr_perror("mount");
+			return 1;
+		}
+		if (chdir(dirname))
+			return 1;
+
+		fd = open("test.ghost", O_CREAT | O_WRONLY, 0600);
+		if (fd < 0) {
+			pr_perror("open");
+			return 1;
+		}
+
+		if (unlink("test.ghost")) {
+			pr_perror("unlink");
+			return 1;
+		}
+
+		task_waiter_complete(&lock, 1);
+		test_waitsig();
+
+		if (close(fd)) {
+			pr_perror("close");
+			return 1;
+		}
+		d = opendir(".");
+		if (d == NULL) {
+			pr_perror("opendir");
+			return 1;
+		}
+		while ((de = readdir(d)) != NULL) {
+			if (!strcmp(de->d_name, "."))
+				continue;
+			if (!strcmp(de->d_name, ".."))
+				continue;
+			pr_err("%s\n", de->d_name);
+		}
+		closedir(d);
+
+		return 0;
+	}
+
+	task_waiter_wait4(&lock, 1);
+	test_daemon();
+	test_waitsig();
+
+
+	kill(pid, SIGTERM);
+	wait(&status);
+	if (status) {
+		fail("Test died");
+		return 1;
+	}
+	pass();
+
+	return 0;
+}

test/zdtm/static/mntns_ghost.desc

+{'flavor': 'ns', 'flags': 'suid', 'feature': 'mnt_id', 'opts': '--link-remap'}