1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or https://opensource.org/licenses/CDDL-1.0.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright (c) 2021 by Lawrence Livermore National Security, LLC.
24 */
25
26 #include <unistd.h>
27 #include <fcntl.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <sys/mman.h>
32 #include <sys/sysmacros.h>
33 #include <errno.h>
34 #ifdef __linux__
35 #include <linux/fs.h>
36 #endif
37
38 static void
seek_data(int fd,off_t offset,off_t expected)39 seek_data(int fd, off_t offset, off_t expected)
40 {
41 off_t data_offset = lseek(fd, offset, SEEK_DATA);
42 if (data_offset != expected) {
43 fprintf(stderr, "lseek(fd, %d, SEEK_DATA) = %d (expected %d)\n",
44 (int)offset, (int)data_offset, (int)expected);
45 exit(2);
46 }
47 }
48
49 static void
seek_hole(int fd,off_t offset,off_t expected)50 seek_hole(int fd, off_t offset, off_t expected)
51 {
52 off_t hole_offset = lseek(fd, offset, SEEK_HOLE);
53 if (hole_offset != expected) {
54 fprintf(stderr, "lseek(fd, %d, SEEK_HOLE) = %d (expected %d)\n",
55 (int)offset, (int)hole_offset, (int)expected);
56 exit(2);
57 }
58 }
59
60 int
main(int argc,char ** argv)61 main(int argc, char **argv)
62 {
63 char *execname = argv[0];
64 char *file_path = argv[1];
65 char *buf = NULL;
66 int err;
67
68 if (argc != 4) {
69 (void) printf("usage: %s <file name> <file size> "
70 "<block size>\n", argv[0]);
71 exit(1);
72 }
73
74 int fd = open(file_path, O_RDWR | O_CREAT, 0666);
75 if (fd == -1) {
76 (void) fprintf(stderr, "%s: %s: ", execname, file_path);
77 perror("open");
78 exit(2);
79 }
80
81 off_t file_size = atoi(argv[2]);
82 off_t block_size = atoi(argv[3]);
83
84 if (block_size * 2 > file_size) {
85 (void) fprintf(stderr, "file size must be at least "
86 "double the block size\n");
87 exit(2);
88 }
89
90 err = ftruncate(fd, file_size);
91 if (err == -1) {
92 perror("ftruncate");
93 exit(2);
94 }
95
96 if ((buf = mmap(NULL, file_size, PROT_READ | PROT_WRITE,
97 MAP_SHARED, fd, 0)) == MAP_FAILED) {
98 perror("mmap");
99 exit(2);
100 }
101
102 /* Verify the file is sparse and reports no data. */
103 seek_data(fd, 0, -1);
104
105 /* Verify the file is reported as a hole. */
106 seek_hole(fd, 0, 0);
107
108 /* Verify search beyond end of file is an error. */
109 seek_data(fd, 2 * file_size, -1);
110 seek_hole(fd, 2 * file_size, -1);
111
112 /* Dirty the first byte. */
113 memset(buf, 'a', 1);
114 seek_data(fd, 0, 0);
115 seek_data(fd, block_size, -1);
116 seek_hole(fd, 0, block_size);
117 seek_hole(fd, block_size, block_size);
118
119 /* Dirty the first half of the file. */
120 memset(buf, 'b', file_size / 2);
121 seek_data(fd, 0, 0);
122 seek_data(fd, block_size, block_size);
123 seek_hole(fd, 0, P2ROUNDUP(file_size / 2, block_size));
124 seek_hole(fd, block_size, P2ROUNDUP(file_size / 2, block_size));
125
126 /* Dirty the whole file. */
127 memset(buf, 'c', file_size);
128 seek_data(fd, 0, 0);
129 seek_data(fd, file_size * 3 / 4,
130 P2ROUNDUP(file_size * 3 / 4, block_size));
131 seek_hole(fd, 0, file_size);
132 seek_hole(fd, file_size / 2, file_size);
133
134 /* Punch a hole (required compression be enabled). */
135 memset(buf + block_size, 0, block_size);
136 seek_data(fd, 0, 0);
137 seek_data(fd, block_size, 2 * block_size);
138 seek_hole(fd, 0, block_size);
139 seek_hole(fd, block_size, block_size);
140 seek_hole(fd, 2 * block_size, file_size);
141
142 err = munmap(buf, file_size);
143 if (err == -1) {
144 perror("munmap");
145 exit(2);
146 }
147
148 close(fd);
149
150 return (0);
151 }
152