1 /*
2 * fallocate - utility to use the fallocate system call
3 *
4 * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
5 * Written by Eric Sandeen <sandeen@redhat.com>
6 *
7 * cvtnum routine taken from xfsprogs,
8 * Copyright (c) 2003-2005 Silicon Graphics, Inc.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it would be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software Foundation,
21 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23
24 #define _LARGEFILE_SOURCE
25 #define _LARGEFILE64_SOURCE
26
27 #include <sys/stat.h>
28 #include <sys/syscall.h>
29 #include <sys/types.h>
30 #include <fcntl.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <unistd.h>
34 #include <ctype.h>
35
36 // #include <linux/falloc.h>
37 #define FALLOC_FL_KEEP_SIZE 0x01
38 #define FALLOC_FL_PUNCH_HOLE 0x02 /* de-allocates range */
39
usage(void)40 void usage(void)
41 {
42 printf("Usage: fallocate [-npt] [-o offset] -l length filename\n");
43 exit(EXIT_FAILURE);
44 }
45
46 #define EXABYTES(x) ((long long)(x) << 60)
47 #define PETABYTES(x) ((long long)(x) << 50)
48 #define TERABYTES(x) ((long long)(x) << 40)
49 #define GIGABYTES(x) ((long long)(x) << 30)
50 #define MEGABYTES(x) ((long long)(x) << 20)
51 #define KILOBYTES(x) ((long long)(x) << 10)
52
53 long long
cvtnum(char * s)54 cvtnum(char *s)
55 {
56 long long i;
57 char *sp;
58 int c;
59
60 i = strtoll(s, &sp, 0);
61 if (i == 0 && sp == s)
62 return -1LL;
63 if (*sp == '\0')
64 return i;
65 if (sp[1] != '\0')
66 return -1LL;
67
68 c = tolower(*sp);
69 switch (c) {
70 case 'k':
71 return KILOBYTES(i);
72 case 'm':
73 return MEGABYTES(i);
74 case 'g':
75 return GIGABYTES(i);
76 case 't':
77 return TERABYTES(i);
78 case 'p':
79 return PETABYTES(i);
80 case 'e':
81 return EXABYTES(i);
82 }
83
84 return -1LL;
85 }
86
main(int argc,char ** argv)87 int main(int argc, char **argv)
88 {
89 int fd;
90 char *fname;
91 int opt;
92 loff_t length = -2LL;
93 loff_t offset = 0;
94 int falloc_mode = 0;
95 int error;
96 int tflag = 0;
97
98 while ((opt = getopt(argc, argv, "npl:o:t")) != -1) {
99 switch(opt) {
100 case 'n':
101 /* do not change filesize */
102 falloc_mode = FALLOC_FL_KEEP_SIZE;
103 break;
104 case 'p':
105 /* punch mode */
106 falloc_mode = (FALLOC_FL_PUNCH_HOLE |
107 FALLOC_FL_KEEP_SIZE);
108 break;
109 case 'l':
110 length = cvtnum(optarg);
111 break;
112 case 'o':
113 offset = cvtnum(optarg);
114 break;
115 case 't':
116 tflag++;
117 break;
118 default:
119 usage();
120 }
121 }
122
123 if (length == -2LL) {
124 printf("Error: no length argument specified\n");
125 usage();
126 }
127
128 if (length <= 0) {
129 printf("Error: invalid length value specified\n");
130 usage();
131 }
132
133 if (offset < 0) {
134 printf("Error: invalid offset value specified\n");
135 usage();
136 }
137
138 if (tflag && (falloc_mode & FALLOC_FL_KEEP_SIZE)) {
139 printf("-n and -t options incompatible\n");
140 usage();
141 }
142
143 if (tflag && offset) {
144 printf("-n and -o options incompatible\n");
145 usage();
146 }
147
148 if (optind == argc) {
149 printf("Error: no filename specified\n");
150 usage();
151 }
152
153 fname = argv[optind++];
154
155 /* Should we create the file if it doesn't already exist? */
156 fd = open(fname, O_WRONLY|O_LARGEFILE);
157 if (fd < 0) {
158 perror("Error opening file");
159 exit(EXIT_FAILURE);
160 }
161
162 if (tflag)
163 error = ftruncate(fd, length);
164 else
165 error = syscall(SYS_fallocate, fd, falloc_mode, offset, length);
166
167 if (error < 0) {
168 perror("fallocate failed");
169 exit(EXIT_FAILURE);
170 }
171
172 close(fd);
173 return 0;
174 }
175