1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2021 FUJITSU LIMITED. All rights reserved.
4 * Author: Dai Shili <daisl.fnst@fujitsu.com>
5 */
6
7 /*\
8 * [Description]
9 *
10 * Test the write() system call with O_APPEND.
11 *
12 * The full description of O_APPEND is in open(2) man-pages:
13 * The file is opened in append mode. Before each write(2), the
14 * file offset is positioned at the end of the file, as if with lseek(2).
15 * The modification of the file offset and the write operation are
16 * performed as a single atomic step.
17 *
18 * Writing 2k data to the file, close it and reopen it with O_APPEND.
19 * Verify that the file size is 3k and offset is moved to the end of the file.
20 */
21
22 #include <stdlib.h>
23 #include <inttypes.h>
24 #include "tst_test.h"
25 #include "tst_safe_prw.h"
26
27 #define K1 1024
28 #define K2 (K1 * 2)
29 #define K3 (K1 * 3)
30 #define DATA_FILE "write06_file"
31
32 static int fd = -1;
33 static char *write_buf[2];
34
verify_write(void)35 static void verify_write(void)
36 {
37 off_t off;
38 struct stat statbuf;
39
40 fd = SAFE_OPEN(DATA_FILE, O_RDWR | O_CREAT | O_TRUNC, 0666);
41 SAFE_WRITE(SAFE_WRITE_ALL, fd, write_buf[0], K2);
42 SAFE_CLOSE(fd);
43
44 fd = SAFE_OPEN(DATA_FILE, O_RDWR | O_APPEND);
45 SAFE_FSTAT(fd, &statbuf);
46 if (statbuf.st_size != K2)
47 tst_res(TFAIL, "file size is %ld != K2", statbuf.st_size);
48
49 off = SAFE_LSEEK(fd, K1, SEEK_SET);
50 if (off != K1)
51 tst_brk(TBROK, "Failed to seek to K1");
52
53 SAFE_WRITE(SAFE_WRITE_ALL, fd, write_buf[1], K1);
54
55 off = SAFE_LSEEK(fd, 0, SEEK_CUR);
56 if (off != K3)
57 tst_res(TFAIL, "Wrong offset after write %zu expected %u", off, K3);
58 else
59 tst_res(TPASS, "Offset is correct after write %zu", off);
60
61 SAFE_FSTAT(fd, &statbuf);
62 if (statbuf.st_size != K3)
63 tst_res(TFAIL, "Wrong file size after append %zu expected %u", statbuf.st_size, K3);
64 else
65 tst_res(TPASS, "Correct file size after append %u", K3);
66
67 SAFE_CLOSE(fd);
68 }
69
setup(void)70 static void setup(void)
71 {
72 memset(write_buf[0], 0, K2);
73 memset(write_buf[1], 1, K1);
74 }
75
cleanup(void)76 static void cleanup(void)
77 {
78 if (fd != -1)
79 SAFE_CLOSE(fd);
80
81 SAFE_UNLINK(DATA_FILE);
82 }
83
84 static struct tst_test test = {
85 .needs_tmpdir = 1,
86 .setup = setup,
87 .cleanup = cleanup,
88 .test_all = verify_write,
89 .bufs = (struct tst_buffers[]) {
90 {&write_buf[0], .size = K2},
91 {&write_buf[1], .size = K1},
92 {}
93 }
94 };
95