1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2014 Red Hat, Inc.
4 * Copyright (C) 2021 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
5 */
6
7 /*\
8 * [Description]
9 *
10 * Tests a private mount: private mount does not forward or receive
11 * propagation.
12 *
13 * [Algorithm]
14 *
15 * - Creates directories DIR_A, DIR_B and files DIR_A/"A", DIR_B/"B"
16 * - Unshares mount namespace and makes it private (so mounts/umounts have no
17 * effect on a real system)
18 * - Bind mounts directory DIR_A to DIR_A
19 * - Makes directory DIR_A private
20 * - Clones a new child process with CLONE_NEWNS flag
21 * - There are two test cases (where X is parent namespace and Y child
22 * namespace):
23 * 1. First test case
24 * .. X: bind mounts DIR_B to DIR_A
25 * .. Y: must see DIR_A/"A" and must not see DIR_A/"B"
26 * .. X: umounts DIR_A
27 * 2. Second test case
28 * .. Y: bind mounts DIR_B to DIR_A
29 * .. X: must see DIR_A/"A" and must not see DIR_A/"B"
30 * .. Y: umounts DIRA
31 */
32
33 #include <sys/wait.h>
34 #include <sys/mount.h>
35 #include "mountns.h"
36 #include "tst_test.h"
37
child_func(LTP_ATTRIBUTE_UNUSED void * arg)38 static int child_func(LTP_ATTRIBUTE_UNUSED void *arg)
39 {
40 TST_CHECKPOINT_WAIT(0);
41
42 if ((access(DIRA "/A", F_OK) != 0) || (access(DIRA "/B", F_OK) == 0))
43 tst_res(TFAIL, "private mount in parent failed");
44 else
45 tst_res(TPASS, "private mount in parent passed");
46
47 TST_CHECKPOINT_WAKE_AND_WAIT(0);
48
49 SAFE_MOUNT(DIRB, DIRA, "none", MS_BIND, NULL);
50
51 TST_CHECKPOINT_WAKE_AND_WAIT(0);
52
53 SAFE_UMOUNT(DIRA);
54
55 return 0;
56 }
57
run(void)58 static void run(void)
59 {
60 int ret;
61
62 SAFE_UNSHARE(CLONE_NEWNS);
63
64 /* makes sure parent mounts/umounts have no effect on a real system */
65 SAFE_MOUNT("none", "/", "none", MS_REC | MS_PRIVATE, NULL);
66
67 SAFE_MOUNT(DIRA, DIRA, "none", MS_BIND, NULL);
68
69 SAFE_MOUNT("none", DIRA, "none", MS_PRIVATE, NULL);
70
71 ret = ltp_clone_quick(CLONE_NEWNS | SIGCHLD, child_func, NULL);
72 if (ret < 0)
73 tst_brk(TBROK, "clone failed");
74
75 SAFE_MOUNT(DIRB, DIRA, "none", MS_BIND, NULL);
76
77 TST_CHECKPOINT_WAKE_AND_WAIT(0);
78
79 SAFE_UMOUNT(DIRA);
80
81 TST_CHECKPOINT_WAKE_AND_WAIT(0);
82
83 if ((access(DIRA "/A", F_OK) != 0) || (access(DIRA "/B", F_OK) == 0))
84 tst_res(TFAIL, "private mount in child failed");
85 else
86 tst_res(TPASS, "private mount in child passed");
87
88 TST_CHECKPOINT_WAKE(0);
89
90 SAFE_WAIT(NULL);
91
92 SAFE_UMOUNT(DIRA);
93 }
94
setup(void)95 static void setup(void)
96 {
97 check_newns();
98 create_folders();
99 }
100
cleanup(void)101 static void cleanup(void)
102 {
103 umount_folders();
104 }
105
106 static struct tst_test test = {
107 .setup = setup,
108 .cleanup = cleanup,
109 .test_all = run,
110 .needs_root = 1,
111 .needs_checkpoints = 1,
112 };
113