1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2014 Red Hat, Inc.
4 * Copyright (C) 2021 SUSE LLC Andrea Cervesato <[email protected]>
5 */
6
7 /*\
8 * [Description]
9 *
10 * Tests an unbindable mount: unbindable mount is an unbindable
11 * private mount.
12 *
13 * - Creates directories DIRA, DIRB and files DIRA/"A", DIRB/"B"
14 * - Unshares mount namespace and makes it private (so mounts/umounts have no
15 * effect on a real system)
16 * - Bind mounts directory DIRA to DIRA
17 * - Makes directory DIRA unbindable
18 * - Check if bind mount unbindable DIRA to DIRB fails as expected
19 */
20
21 #include <sys/wait.h>
22 #include <sys/mount.h>
23 #include "mountns.h"
24 #include "tst_test.h"
25 #include "lapi/sched.h"
26
run(void)27 static void run(void)
28 {
29 SAFE_UNSHARE(CLONE_NEWNS);
30
31 /* makes sure mounts/umounts have no effect on a real system */
32 SAFE_MOUNT("none", "/", "none", MS_REC | MS_PRIVATE, NULL);
33
34 SAFE_MOUNT(DIRA, DIRA, "none", MS_BIND, NULL);
35
36 SAFE_MOUNT("none", DIRA, "none", MS_UNBINDABLE, NULL);
37
38 if (mount(DIRA, DIRB, "none", MS_BIND, NULL) == -1) {
39 tst_res(TPASS, "unbindable mount passed");
40 } else {
41 SAFE_UMOUNT(DIRB);
42 tst_res(TFAIL, "unbindable mount faled");
43 }
44
45 SAFE_UMOUNT(DIRA);
46 }
47
setup(void)48 static void setup(void)
49 {
50 create_folders();
51 }
52
cleanup(void)53 static void cleanup(void)
54 {
55 umount_folders();
56 }
57
58 static struct tst_test test = {
59 .setup = setup,
60 .cleanup = cleanup,
61 .test_all = run,
62 .needs_root = 1,
63 .needs_tmpdir = 1,
64 .needs_kconfigs = (const char *[]) {
65 "CONFIG_USER_NS",
66 NULL,
67 },
68 };
69