1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) Linux Test Project, 2021
4 * Copyright (c) International Business Machines Corp., 2002
5 * ported from SPIE, section2/filesuite/pread_pwrite.c, by Airong Zhang
6 */
7
8 /*\
9 * [Description]
10 *
11 * Test the pwrite() system call with O_APPEND.
12 *
13 * Writing 2k data to the file, close it and reopen it with O_APPEND.
14 *
15 * POSIX requires that opening a file with the O_APPEND flag should have no effect on the
16 * location at which pwrite() writes data. However, on Linux, if a file is opened with
17 * O_APPEND, pwrite() appends data to the end of the file, regardless of the value of offset.
18 */
19
20 #include <stdlib.h>
21 #include <inttypes.h>
22 #include "tst_test.h"
23 #include "tst_safe_prw.h"
24
25 #define K1 1024
26 #define K2 (K1 * 2)
27 #define K3 (K1 * 3)
28 #define DATA_FILE "pwrite04_file"
29
30 static int fd = -1;
31 static char *write_buf[2];
32
l_seek(int fdesc,off_t offset,int whence,off_t checkoff)33 static void l_seek(int fdesc, off_t offset, int whence, off_t checkoff)
34 {
35 off_t offloc;
36
37 offloc = SAFE_LSEEK(fdesc, offset, whence);
38 if (offloc != checkoff) {
39 tst_res(TFAIL, "%" PRId64 " = lseek(%d, %" PRId64 ", %d) != %" PRId64,
40 (int64_t)offloc, fdesc, (int64_t)offset, whence, (int64_t)checkoff);
41 }
42 }
43
verify_pwrite(void)44 static void verify_pwrite(void)
45 {
46 struct stat statbuf;
47
48 fd = SAFE_OPEN(DATA_FILE, O_RDWR | O_CREAT | O_TRUNC, 0666);
49 SAFE_PWRITE(1, fd, write_buf[0], K2, 0);
50 SAFE_CLOSE(fd);
51
52 fd = SAFE_OPEN(DATA_FILE, O_RDWR | O_APPEND, 0666);
53 SAFE_FSTAT(fd, &statbuf);
54 if (statbuf.st_size != K2)
55 tst_res(TFAIL, "file size is %ld != K2", statbuf.st_size);
56
57 /* Appends data to the end of the file regardless of offset. */
58 l_seek(fd, K1, SEEK_SET, K1);
59 SAFE_PWRITE(1, fd, write_buf[1], K1, 0);
60 l_seek(fd, 0, SEEK_CUR, K1);
61 SAFE_FSTAT(fd, &statbuf);
62 if (statbuf.st_size != K3)
63 tst_res(TFAIL, "file size is %ld != K3", statbuf.st_size);
64
65 tst_res(TPASS, "O_APPEND test passed.");
66 SAFE_CLOSE(fd);
67 }
68
setup(void)69 static void setup(void)
70 {
71 write_buf[0] = SAFE_MALLOC(K2);
72 memset(write_buf[0], 0, K2);
73 write_buf[1] = SAFE_MALLOC(K1);
74 memset(write_buf[0], 1, K1);
75 }
76
cleanup(void)77 static void cleanup(void)
78 {
79 free(write_buf[0]);
80 free(write_buf[1]);
81
82 if (fd > -1)
83 SAFE_CLOSE(fd);
84
85 SAFE_UNLINK(DATA_FILE);
86 }
87
88 static struct tst_test test = {
89 .needs_tmpdir = 1,
90 .setup = setup,
91 .cleanup = cleanup,
92 .test_all = verify_pwrite,
93 };
94