1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2017 Fujitsu Ltd.
4 * Author: Xiao Yang <[email protected]>
5 */
6
7 /*\
8 * [Description]
9 *
10 * This is a regression test for the race between getting an existing
11 * xattr and setting/removing a large xattr. This bug leads to that
12 * getxattr() fails to get an existing xattr and returns ENOATTR in xfs
13 * filesystem.
14 *
15 * This bug has been fixed in:
16 * 5a93790d4e2d ("xfs: remove racy hasattr check from attr ops")
17 */
18
19 #include "config.h"
20 #include <errno.h>
21 #include <sys/types.h>
22 #include <string.h>
23 #include <stdlib.h>
24 #include <signal.h>
25
26 #ifdef HAVE_SYS_XATTR_H
27 # include <sys/xattr.h>
28 #endif
29
30 #include "tst_test.h"
31
32 #ifdef HAVE_SYS_XATTR_H
33
34 #define MNTPOINT "mntpoint"
35 #define TEST_FILE MNTPOINT "/file"
36 #define TRUSTED_BIG "trusted.big"
37 #define TRUSTED_SMALL "trusted.small"
38
39 static volatile int end;
40 static char big_value[512];
41 static char small_value[32];
42
sigproc(int sig)43 static void sigproc(int sig)
44 {
45 end = sig;
46 }
47
loop_getxattr(void)48 static void loop_getxattr(void)
49 {
50 int res;
51
52 while (!end) {
53 res = getxattr(TEST_FILE, TRUSTED_SMALL, NULL, 0);
54 if (res == -1) {
55 if (errno == ENODATA) {
56 tst_res(TFAIL, "getxattr() failed to get an "
57 "existing attribute");
58 } else {
59 tst_res(TFAIL | TERRNO,
60 "getxattr() failed without ENOATTR");
61 }
62
63 exit(0);
64 }
65 }
66
67 tst_res(TPASS, "getxattr() succeeded to get an existing attribute");
68 exit(0);
69 }
70
verify_getxattr(void)71 static void verify_getxattr(void)
72 {
73 pid_t pid;
74 int n;
75
76 end = 0;
77
78 pid = SAFE_FORK();
79 if (!pid)
80 loop_getxattr();
81
82 for (n = 0; n < 99; n++) {
83 SAFE_SETXATTR(TEST_FILE, TRUSTED_BIG, big_value,
84 sizeof(big_value), XATTR_CREATE);
85 SAFE_REMOVEXATTR(TEST_FILE, TRUSTED_BIG);
86 }
87
88 kill(pid, SIGUSR1);
89 tst_reap_children();
90 }
91
setup(void)92 static void setup(void)
93 {
94 SAFE_SIGNAL(SIGUSR1, sigproc);
95
96 SAFE_TOUCH(TEST_FILE, 0644, NULL);
97
98 memset(big_value, 'a', sizeof(big_value));
99 memset(small_value, 'a', sizeof(small_value));
100
101 SAFE_SETXATTR(TEST_FILE, TRUSTED_SMALL, small_value,
102 sizeof(small_value), XATTR_CREATE);
103 }
104
105 static struct tst_test test = {
106 .needs_root = 1,
107 .mount_device = 1,
108 .dev_fs_type = "xfs",
109 .mntpoint = MNTPOINT,
110 .forks_child = 1,
111 .test_all = verify_getxattr,
112 .setup = setup,
113 .tags = (const struct tst_tag[]) {
114 {"linux-git", "5a93790d4e2d"},
115 {}
116 }
117 };
118
119 #else /* HAVE_SYS_XATTR_H */
120 TST_TEST_TCONF("<sys/xattr.h> does not exist.");
121 #endif
122