1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2004 Daniel McNeil <daniel@osdl.org>
4 * 2004 Open Source Development Lab
5 * 2004 Marty Ridgeway <mridge@us.ibm.com>
6 * Copyright (C) 2021 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
7 */
8
9 /*\
10 * [Description]
11 *
12 * Appends zeroed data to a file using O_DIRECT while a child processes are
13 * doing buffered reads after seeking to the end of the file and checks if the
14 * buffer reads always see zero.
15 */
16
17 #define _GNU_SOURCE
18
19 #include "tst_test.h"
20 #include "common.h"
21
22 static int *run_child;
23
24 static char *str_numchildren;
25 static char *str_writesize;
26 static char *str_appends;
27
28 static int numchildren;
29 static long long writesize;
30 static int appends;
31
setup(void)32 static void setup(void)
33 {
34 numchildren = 16;
35 writesize = 64 * 1024;
36 appends = 1000;
37
38 if (tst_parse_int(str_numchildren, &numchildren, 1, INT_MAX))
39 tst_brk(TBROK, "Invalid number of children '%s'", str_numchildren);
40
41 if (tst_parse_filesize(str_writesize, &writesize, 1, LLONG_MAX))
42 tst_brk(TBROK, "Invalid write file size '%s'", str_writesize);
43
44 if (tst_parse_int(str_appends, &appends, 1, INT_MAX))
45 tst_brk(TBROK, "Invalid number of appends '%s'", str_appends);
46
47 run_child = SAFE_MMAP(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
48 }
49
cleanup(void)50 static void cleanup(void)
51 {
52 SAFE_MUNMAP(run_child, sizeof(int));
53 }
54
run(void)55 static void run(void)
56 {
57 char *filename = "dio_append";
58 int status;
59 int i;
60
61 *run_child = 1;
62
63 for (i = 0; i < numchildren; i++) {
64 if (!SAFE_FORK()) {
65 io_read_eof(filename, run_child);
66 return;
67 }
68 }
69
70 tst_res(TINFO, "Parent append to file");
71
72 io_append(filename, 0, O_DIRECT | O_WRONLY | O_CREAT, writesize, appends);
73
74 if (SAFE_WAITPID(-1, &status, WNOHANG))
75 tst_res(TFAIL, "Non zero bytes read");
76 else
77 tst_res(TPASS, "All bytes read were zeroed");
78
79 *run_child = 0;
80
81 SAFE_UNLINK(filename);
82 }
83
84 static struct tst_test test = {
85 .test_all = run,
86 .setup = setup,
87 .cleanup = cleanup,
88 .needs_tmpdir = 1,
89 .forks_child = 1,
90 .options = (struct tst_option[]) {
91 {"n:", &str_numchildren, "Number of processes (default 16)"},
92 {"w:", &str_writesize, "Write size for each append (default 64K)"},
93 {"c:", &str_appends, "Number of appends (default 1000)"},
94 {}
95 },
96 .skip_filesystems = (const char *[]) {
97 "tmpfs",
98 NULL
99 },
100 };
101