1 /*
2  * Copyright (c) 2004 Daniel McNeil <daniel@osdl.org>
3  *               2004 Open Source Development Lab
4  *   This program is free software;  you can redistribute it and/or modify
5  *   it under the terms of the GNU General Public License as published by
6  *   the Free Software Foundation; either version 2 of the License, or
7  *   (at your option) any later version.
8  *
9  *   This program is distributed in the hope that it will be useful,
10  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
12  *   the GNU General Public License for more details.
13  *
14  *   You should have received a copy of the GNU General Public License
15  *   along with this program;  if not, write to the Free Software
16  *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  *
18  * Module: .c
19  * Change History:
20  *
21  * 2/2004  Marty Ridgeway (mridge@us.ibm.com) Changes to adapt to LTP
22  *
23 */
24 
25 #define _GNU_SOURCE
26 
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <sys/types.h>
30 #include <signal.h>
31 #include <fcntl.h>
32 #include <unistd.h>
33 
34 #include <libaio.h>
35 
36 #define NUM_CHILDREN 8
37 
check_zero(unsigned char * buf,int size)38 char *check_zero(unsigned char *buf, int size)
39 {
40 	unsigned char *p;
41 
42 	p = buf;
43 
44 	while (size > 0) {
45 		if (*buf != 0) {
46 			fprintf(stderr,
47 				"non zero buffer at buf[%d] => 0x%02x,%02x,%02x,%02x\n",
48 				buf - p, (unsigned int)buf[0],
49 				size > 1 ? (unsigned int)buf[1] : 0,
50 				size > 2 ? (unsigned int)buf[2] : 0,
51 				size > 3 ? (unsigned int)buf[3] : 0);
52 			fprintf(stderr, "buf %p, p %p\n", buf, p);
53 			return buf;
54 		}
55 		buf++;
56 		size--;
57 	}
58 	return 0;		/* all zeros */
59 }
60 
read_eof(char * filename)61 int read_eof(char *filename)
62 {
63 	int fd;
64 	int i;
65 	int r;
66 	char buf[4096];
67 
68 	while ((fd = open(filename, O_RDONLY)) < 0) {
69 		sleep(1);	/* wait for file to be created */
70 	}
71 
72 	for (i = 0; i < 1000000; i++) {
73 		off_t offset;
74 		char *bufoff;
75 
76 		offset = lseek(fd, SEEK_END, 0);
77 		r = read(fd, buf, 4096);
78 		if (r > 0) {
79 			if ((bufoff = check_zero(buf, r))) {
80 				fprintf(stderr, "non-zero read at offset %p\n",
81 					offset + bufoff);
82 				exit(1);
83 			}
84 		}
85 	}
86 	return 0;
87 }
88 
89 #define NUM_AIO 16
90 #define AIO_SIZE 64*1024
91 
92 /*
93  * append to the end of a file using AIO DIRECT.
94  */
aiodio_append(char * filename)95 void aiodio_append(char *filename)
96 {
97 	int fd;
98 	void *bufptr;
99 	int i;
100 	int w;
101 	struct iocb iocb_array[NUM_AIO];
102 	struct iocb *iocbs[NUM_AIO];
103 	off_t offset = 0;
104 	io_context_t myctx;
105 	struct io_event event;
106 	struct timespec timeout;
107 
108 	fd = open(filename, O_DIRECT | O_WRONLY | O_CREAT, 0666);
109 	if (fd < 0) {
110 		perror("cannot create file");
111 		return;
112 	}
113 
114 	memset(&myctx, 0, sizeof(myctx));
115 	io_queue_init(NUM_AIO, &myctx);
116 
117 	for (i = 0; i < NUM_AIO; i++) {
118 		if (posix_memalign(&bufptr, 4096, AIO_SIZE)) {
119 			perror("cannot malloc aligned memory");
120 			return;
121 		}
122 		memset(bufptr, 0, AIO_SIZE);
123 		io_prep_pwrite(&iocb_array[i], fd, bufptr, AIO_SIZE, offset);
124 		iocbs[i] = &iocb_array[i];
125 		offset += AIO_SIZE;
126 	}
127 
128 	/*
129 	 * Start the 1st NUM_AIO requests
130 	 */
131 	if ((w = io_submit(myctx, NUM_AIO, iocbs)) < 0) {
132 		fprintf(stderr, "io_submit write returned %d\n", w);
133 	}
134 
135 	/*
136 	 * As AIO requests finish, keep issuing more AIOs.
137 	 */
138 	for (; i < 1000; i++) {
139 		int n = 0;
140 		struct iocb *iocbp;
141 
142 		n = io_getevents(myctx, 1, 1, &event, &timeout);
143 		if (n > 0) {
144 			iocbp = (struct iocb *)event.obj;
145 
146 			if (n > 0) {
147 				io_prep_pwrite(iocbp, fd, iocbp->u.c.buf,
148 					       AIO_SIZE, offset);
149 				offset += AIO_SIZE;
150 				if ((w = io_submit(myctx, 1, &iocbp)) < 0) {
151 					fprintf(stderr,
152 						"write %d returned %d\n", i, w);
153 				}
154 			}
155 		}
156 	}
157 }
158 
main(int argc,char ** argv)159 int main(int argc, char **argv)
160 {
161 	int pid[NUM_CHILDREN];
162 	int num_children = 1;
163 	int i;
164 	char *filename = argv[1];
165 
166 	printf("Starting aio/dio append test...\n");
167 
168 	for (i = 0; i < num_children; i++) {
169 		if ((pid[i] = fork()) == 0) {
170 			/* child */
171 			return read_eof(filename);
172 		} else if (pid[i] < 0) {
173 			/* error */
174 			perror("fork error");
175 			break;
176 		} else {
177 			/* Parent */
178 			continue;
179 		}
180 	}
181 
182 	/*
183 	 * Parent appends to end of file using direct i/o
184 	 */
185 
186 	aiodio_append(filename);
187 
188 	for (i = 0; i < num_children; i++) {
189 		kill(pid[i], SIGTERM);
190 	}
191 
192 	return 0;
193 }
194