1
2 /*
3 * Copyright (c) 2004 Daniel McNeil <daniel@osdl.org>
4 * 2004 Open Source Development Lab
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Module: .c
20 */
21
22 /*
23 * Change History:
24 *
25 * 2/2004 Marty Ridgeway (mridge@us.ibm.com) Changes to adapt to LTP
26 *
27 */
28 /*
29 * dio_append - append zeroed data to a file using O_DIRECT while
30 * a 2nd process is doing buffered reads and check if the buffer
31 * reads always see zero.
32 */
33 #define _GNU_SOURCE
34
35 #include <stdlib.h>
36 #include <sys/types.h>
37 #include <signal.h>
38 #include <errno.h>
39 #include <fcntl.h>
40 #include <stdio.h>
41 #include <unistd.h>
42 #include <memory.h>
43 #include <limits.h>
44
45 #include "test.h"
46 #define NUM_CHILDREN 8
47
48 #include "common_checkzero.h"
49
read_eof(char * filename)50 int read_eof(char *filename)
51 {
52 int fd;
53 int i;
54 int r;
55 char buf[4096];
56
57 while ((fd = open(filename, O_RDONLY)) < 0) {
58 sleep(1); /* wait for file to be created */
59 }
60
61 for (i = 0; i < 1000000; i++) {
62 off_t offset;
63 char *bufoff;
64
65 offset = lseek(fd, SEEK_END, 0);
66 r = read(fd, buf, 4096);
67 if (r > 0) {
68 if ((bufoff = check_zero(buf, r))) {
69 fprintf(stderr, "non-zero read at offset %p\n",
70 offset + bufoff);
71 exit(1);
72 }
73 }
74 }
75 return 0;
76 }
77
dio_append(char * filename)78 void dio_append(char *filename)
79 {
80 int fd;
81 void *bufptr;
82 int i;
83 int w;
84
85 fd = open(filename, O_DIRECT | O_WRONLY | O_CREAT, 0666);
86
87 if (fd < 0) {
88 perror("cannot create file");
89 return;
90 }
91
92 TEST(posix_memalign(&bufptr, 4096, 64 * 1024));
93 if (TEST_RETURN) {
94 tst_resm(TBROK | TRERRNO, "cannot malloc aligned memory");
95 close(fd);
96 return;
97 }
98
99 memset(bufptr, 0, 64 * 1024);
100 for (i = 0; i < 1000; i++) {
101 if ((w = write(fd, bufptr, 64 * 1024)) != 64 * 1024) {
102 fprintf(stderr, "write %d returned %d\n", i, w);
103 }
104 }
105 }
106
main(int argc,char ** argv)107 int main(int argc, char **argv)
108 {
109 char filename[PATH_MAX];
110 int pid[NUM_CHILDREN];
111 int num_children = 1;
112 int i;
113
114 snprintf(filename, sizeof(filename), "%s/aiodio/file",
115 getenv("TMP") ? getenv("TMP") : "/tmp");
116
117 printf("Begin dio_append test...\n");
118
119 for (i = 0; i < num_children; i++) {
120 if ((pid[i] = fork()) == 0) {
121 /* child */
122 return read_eof(filename);
123 } else if (pid[i] < 0) {
124 /* error */
125 perror("fork error");
126 break;
127 } else {
128 /* Parent */
129 continue;
130 }
131 }
132
133 /*
134 * Parent appends to end of file using direct i/o
135 */
136
137 dio_append(filename);
138
139 for (i = 0; i < num_children; i++) {
140 kill(pid[i], SIGTERM);
141 }
142 return 0;
143 }
144