1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2020 FUJITSU LIMITED. All rights reserved.
4 * Copyright (c) Linux Test Project, 2022
5 * Author: Yang Xu <[email protected]>
6 */
7
8 /*\
9 * [Description]
10 *
11 * Tests ioctl() on loopdevice with LO_FLAGS_READ_ONLY (similar as losetup -r) and
12 * LOOP_CHANGE_FD flags.
13 *
14 * For LOOP_CHANGE_FD, this operation is possible only if the loop device
15 * is read-only and the new backing store is the same size and type as the
16 * old backing store.
17 *
18 * When using LOOP_CONFIGURE ioctl(), it can set LO_FLAGS_READ_ONLY
19 * flag even though backing file with write mode.
20 */
21
22 #include <stdio.h>
23 #include <unistd.h>
24 #include <string.h>
25 #include <stdlib.h>
26 #include "lapi/loop.h"
27 #include "tst_test.h"
28
29 static int file_fd, file_change_fd, file_fd_invalid;
30 static char backing_path[1024], backing_file_path[1024], backing_file_change_path[1024];
31 static int attach_flag, dev_fd, loop_configure_sup = 1;
32 static char loop_ro_path[1024], dev_path[1024];
33 static struct loop_config loopconfig;
34
35 static struct tcase {
36 int mode;
37 int ioctl;
38 char *message;
39 } tcases[] = {
40 {O_RDONLY, LOOP_SET_FD, "Using LOOP_SET_FD to setup loopdevice"},
41 {O_RDWR, LOOP_CONFIGURE, "Using LOOP_CONFIGURE with read_only flag"},
42 };
43
verify_ioctl_loop(unsigned int n)44 static void verify_ioctl_loop(unsigned int n)
45 {
46 struct tcase *tc = &tcases[n];
47 struct loop_info loopinfoget;
48
49 if (tc->ioctl == LOOP_CONFIGURE && !loop_configure_sup) {
50 tst_res(TCONF, "LOOP_CONFIGURE ioctl not supported");
51 return;
52 }
53
54 tst_res(TINFO, "%s", tc->message);
55 file_fd = SAFE_OPEN("test.img", tc->mode);
56
57 if (tc->ioctl == LOOP_SET_FD) {
58 SAFE_IOCTL(dev_fd, LOOP_SET_FD, file_fd);
59 } else {
60 loopconfig.fd = file_fd;
61 SAFE_IOCTL(dev_fd, LOOP_CONFIGURE, &loopconfig);
62 }
63 attach_flag = 1;
64
65 TST_ASSERT_INT(loop_ro_path, 1);
66 TST_ASSERT_STR(backing_path, backing_file_path);
67
68 memset(&loopinfoget, 0, sizeof(loopinfoget));
69
70 SAFE_IOCTL(dev_fd, LOOP_GET_STATUS, &loopinfoget);
71
72 if (loopinfoget.lo_flags & ~LO_FLAGS_READ_ONLY)
73 tst_res(TFAIL, "lo_flags has unexpected %d flag", loopinfoget.lo_flags);
74 else
75 tst_res(TPASS, "lo_flags only has default LO_FLAGS_READ_ONLY flag");
76
77 TEST(write(dev_fd, "xx", 2));
78 if (TST_RET != -1)
79 tst_res(TFAIL, "write succeed unexpectedly");
80 else
81 tst_res(TPASS | TTERRNO, "Can not write data in RO mode");
82
83 TEST(ioctl(dev_fd, LOOP_CHANGE_FD, file_change_fd));
84 if (TST_RET) {
85 tst_res(TFAIL | TTERRNO, "LOOP_CHANGE_FD failed");
86 } else {
87 tst_res(TPASS, "LOOP_CHANGE_FD succeeded");
88 TST_ASSERT_INT(loop_ro_path, 1);
89 TST_ASSERT_STR(backing_path, backing_file_change_path);
90 }
91
92 TEST(ioctl(dev_fd, LOOP_CHANGE_FD, file_fd_invalid));
93 if (TST_RET) {
94 if (TST_ERR == EINVAL)
95 tst_res(TPASS | TTERRNO, "LOOP_CHANGE_FD failed as expected");
96 else
97 tst_res(TFAIL | TTERRNO, "LOOP_CHANGE_FD failed expected EINVAL got");
98 } else {
99 tst_res(TFAIL, "LOOP_CHANGE_FD succeeded");
100 }
101
102 SAFE_CLOSE(file_fd);
103 tst_detach_device_by_fd(dev_path, dev_fd);
104 dev_fd = SAFE_OPEN(dev_path, O_RDWR);
105 attach_flag = 0;
106 }
107
setup(void)108 static void setup(void)
109 {
110 int dev_num;
111 int ret;
112
113 char *tmpdir = tst_get_tmpdir();
114 dev_num = tst_find_free_loopdev(dev_path, sizeof(dev_path));
115 if (dev_num < 0)
116 tst_brk(TBROK, "Failed to find free loop device");
117
118 tst_fill_file("test.img", 0, 1024, 10);
119 tst_fill_file("test1.img", 0, 1024, 10);
120 tst_fill_file("test2.img", 0, 2048, 20);
121
122 sprintf(backing_path, "/sys/block/loop%d/loop/backing_file", dev_num);
123 sprintf(backing_file_path, "%s/test.img", tmpdir);
124 sprintf(backing_file_change_path, "%s/test1.img", tmpdir);
125 sprintf(loop_ro_path, "/sys/block/loop%d/ro", dev_num);
126
127 free(tmpdir);
128
129 file_change_fd = SAFE_OPEN("test1.img", O_RDWR);
130 file_fd_invalid = SAFE_OPEN("test2.img", O_RDWR);
131
132 dev_fd = SAFE_OPEN(dev_path, O_RDWR);
133 loopconfig.fd = -1;
134 ret = ioctl(dev_fd, LOOP_CONFIGURE, &loopconfig);
135
136 if (ret && errno != EBADF) {
137 tst_res(TINFO | TERRNO, "LOOP_CONFIGURE is not supported");
138 loop_configure_sup = 0;
139 }
140 loopconfig.info.lo_flags = LO_FLAGS_READ_ONLY;
141 }
142
cleanup(void)143 static void cleanup(void)
144 {
145 if (dev_fd > 0)
146 SAFE_CLOSE(dev_fd);
147 if (file_fd > 0)
148 SAFE_CLOSE(file_fd);
149 if (file_change_fd > 0)
150 SAFE_CLOSE(file_change_fd);
151 if (file_fd_invalid > 0)
152 SAFE_CLOSE(file_fd_invalid);
153 if (attach_flag)
154 tst_detach_device(dev_path);
155 }
156
157 static struct tst_test test = {
158 .setup = setup,
159 .cleanup = cleanup,
160 .tcnt = ARRAY_SIZE(tcases),
161 .test = verify_ioctl_loop,
162 .needs_root = 1,
163 .needs_tmpdir = 1,
164 .needs_drivers = (const char *const []) {
165 "loop",
166 NULL
167 }
168 };
169