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 #define _GNU_SOURCE
29
30 #include <stdlib.h>
31 #include <sys/types.h>
32 #include <signal.h>
33 #include <fcntl.h>
34 #include <stdio.h>
35 #include <unistd.h>
36 #include <memory.h>
37 #include <string.h>
38 #include <limits.h>
39
40 #define NUM_CHILDREN 8
41
check_zero(unsigned char * buf,int size)42 char *check_zero(unsigned char *buf, int size)
43 {
44 unsigned char *p;
45
46 p = buf;
47
48 while (size > 0) {
49 if (*buf != 0) {
50 fprintf(stderr,
51 "non zero buffer at buf[%d] => 0x%02x,%02x,%02x,%02x\n",
52 buf - p, (unsigned int)buf[0],
53 size > 1 ? (unsigned int)buf[1] : 0,
54 size > 2 ? (unsigned int)buf[2] : 0,
55 size > 3 ? (unsigned int)buf[3] : 0);
56 fprintf(stderr, "buf %p, p %p\n", buf, p);
57 return buf;
58 }
59 buf++;
60 size--;
61 }
62 return 0; /* all zeros */
63 }
64
dio_read(char * filename)65 int dio_read(char *filename)
66 {
67 int fd;
68 int r;
69 void *bufptr;
70
71 if (posix_memalign(&bufptr, 4096, 64 * 1024)) {
72 perror("cannot malloc aligned memory");
73 return -1;
74 }
75
76 while ((fd = open(filename, O_DIRECT | O_RDONLY)) < 0) {
77 }
78 fprintf(stderr, "dio_truncate: child reading file\n");
79 while (1) {
80 off_t offset;
81 char *bufoff;
82
83 /* read the file, checking for zeros */
84 offset = lseek(fd, SEEK_SET, 0);
85 do {
86 r = read(fd, bufptr, 64 * 1024);
87 if (r > 0) {
88 if ((bufoff = check_zero(bufptr, r))) {
89 fprintf(stderr,
90 "non-zero read at offset %p\n",
91 offset + bufoff);
92 exit(1);
93 }
94 offset += r;
95 }
96 } while (r > 0);
97 }
98 return 0;
99 }
100
dio_append(char * filename,int fill)101 void dio_append(char *filename, int fill)
102 {
103 int fd;
104 void *bufptr;
105 int i;
106 int w;
107
108 fd = open(filename, O_DIRECT | O_WRONLY | O_CREAT, 0666);
109
110 if (fd < 0) {
111 perror("cannot create file");
112 return;
113 }
114
115 if (posix_memalign(&bufptr, 4096, 64 * 1024)) {
116 perror("cannot malloc aligned memory");
117 return;
118 }
119
120 memset(bufptr, fill, 64 * 1024);
121
122 for (i = 0; i < 1000; i++) {
123 if ((w = write(fd, bufptr, 64 * 1024)) != 64 * 1024) {
124 fprintf(stderr, "write %d returned %d\n", i, w);
125 }
126 }
127 close(fd);
128 }
129
main(int argc,char ** argv)130 int main(int argc, char **argv)
131 {
132 char filename[PATH_MAX];
133 int pid[NUM_CHILDREN];
134 int num_children = 1;
135 int i;
136
137 snprintf(filename, sizeof(filename), "%s/aiodio/file",
138 getenv("TMP") ? getenv("TMP") : "/tmp");
139
140 for (i = 0; i < num_children; i++) {
141 if ((pid[i] = fork()) == 0) {
142 /* child */
143 return dio_read(filename);
144 } else if (pid[i] < 0) {
145 /* error */
146 perror("fork error");
147 break;
148 } else {
149 /* Parent */
150 continue;
151 }
152 }
153
154 /*
155 * Parent creates a zero file using DIO.
156 * Truncates it to zero
157 * Create another file with '0xaa'
158 */
159 for (i = 0; i < 100; i++) {
160 dio_append(filename, 0);
161 truncate(filename, 0);
162 dio_append("junkfile", 0xaa);
163 truncate("junkfile", 0);
164 }
165
166 for (i = 0; i < num_children; i++) {
167 kill(pid[i], SIGTERM);
168 }
169
170 return 0;
171 }
172