1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Copyright (c) Matthew Wilcox for Hewlett Packard 2003
3 * Author: Matthew Wilcox
4 *
5 * Test Description:
6 *  This test verifies that flock locks held on one fd conflict with flock
7 *  locks held on a different fd.
8 *
9 * Test Steps:
10 *  The process opens two file descriptors on the same file.  It acquires
11 *  an exclusive flock on the first descriptor, checks that attempting to
12 *  acquire an flock on the second descriptor fails.  Then it removes the
13 *  first descriptor's lock and attempts to acquire an exclusive lock on
14 *  the second descriptor.
15 */
16
17#include <errno.h>
18#include <sys/file.h>
19
20#include "tst_test.h"
21
22static void verify_flock(void)
23{
24	int fd1, fd2;
25
26	fd1 = SAFE_OPEN("testfile", O_RDWR);
27	TEST(flock(fd1, LOCK_EX | LOCK_NB));
28	if (TST_RET != 0)
29		tst_res(TFAIL | TTERRNO, "First attempt to flock() failed");
30	else
31		tst_res(TPASS, "First attempt to flock() passed");
32
33	fd2 = SAFE_OPEN("testfile", O_RDWR);
34	TEST(flock(fd2, LOCK_EX | LOCK_NB));
35	if (TST_RET == -1)
36		tst_res(TPASS | TTERRNO, "Second attempt to flock() denied");
37	else
38		tst_res(TFAIL, "Second attempt to flock() succeeded!");
39
40	TEST(flock(fd1, LOCK_UN));
41	if (TST_RET != 0)
42		tst_res(TFAIL | TTERRNO, "Failed to unlock fd1");
43	else
44		tst_res(TPASS, "Unlocked fd1");
45
46	TEST(flock(fd2, LOCK_EX | LOCK_NB));
47	if (TST_RET != 0)
48		tst_res(TFAIL | TTERRNO, "Third attempt to flock() denied!");
49	else
50		tst_res(TPASS, "Third attempt to flock() succeeded");
51
52	SAFE_CLOSE(fd1);
53	SAFE_CLOSE(fd2);
54}
55
56static void setup(void)
57{
58	int fd;
59
60	fd = SAFE_OPEN("testfile", O_CREAT | O_TRUNC | O_RDWR, 0666);
61	SAFE_CLOSE(fd);
62}
63
64static struct tst_test test = {
65	.test_all = verify_flock,
66	.needs_tmpdir = 1,
67	.setup = setup,
68};
69