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
38static void
39seek_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
49static void
50seek_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
60int
61main(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