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 http://www.opensolaris.org/os/licensing.
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 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * Copyright (c) 2012 by Delphix. All rights reserved.
29  */
30 
31 #include "file_common.h"
32 #include <sys/types.h>
33 #include <unistd.h>
34 #include <fcntl.h>
35 #include <string.h>
36 #include <linux/falloc.h>
37 
38 /*
39  * Create a file with assigned size and then free the specified
40  * section of the file
41  */
42 
43 static void usage(char *progname);
44 
45 static void
46 usage(char *progname)
47 {
48 	(void) fprintf(stderr,
49 	    "usage: %s [-l filesize] [-s start-offset]"
50 	    "[-n section-len] filename\n", progname);
51 	exit(1);
52 }
53 
54 int
55 main(int argc, char *argv[])
56 {
57 	char *filename = NULL;
58 	char *buf = NULL;
59 	size_t filesize = 0;
60 	off_t start_off = 0;
61 	off_t off_len = 0;
62 	int  fd, ch;
63 	mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
64 
65 	while ((ch = getopt(argc, argv, "l:s:n:")) != EOF) {
66 		switch (ch) {
67 		case 'l':
68 			filesize = atoll(optarg);
69 			break;
70 		case 's':
71 			start_off = atoll(optarg);
72 			break;
73 		case 'n':
74 			off_len = atoll(optarg);
75 			break;
76 		default:
77 			usage(argv[0]);
78 			break;
79 		}
80 	}
81 
82 	if (optind == argc - 1)
83 		filename = argv[optind];
84 	else
85 		usage(argv[0]);
86 
87 	if ((fd = open(filename, O_RDWR | O_CREAT | O_TRUNC, mode)) < 0) {
88 		perror("open");
89 		return (1);
90 	}
91 
92 	buf = (char *)calloc(1, filesize);
93 	if (buf == NULL) {
94 		perror("write");
95 		close(fd);
96 		return (1);
97 	}
98 	memset(buf, 'c', filesize);
99 
100 	if (write(fd, buf, filesize) < filesize) {
101 		free(buf);
102 		perror("write");
103 		close(fd);
104 		return (1);
105 	}
106 
107 	free(buf);
108 
109 #if defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE)
110 	if (fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
111 	    start_off, off_len) < 0) {
112 		perror("fallocate");
113 		close(fd);
114 		return (1);
115 	}
116 #else /* !(defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE)) */
117 	{
118 		perror("FALLOC_FL_PUNCH_HOLE unsupported");
119 		close(fd);
120 		return (1);
121 	}
122 #endif /* defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE) */
123 	close(fd);
124 	return (0);
125 }
126