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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 #ifndef _LARGEFILE_SOURCE
25 #define _LARGEFILE_SOURCE
26 #endif
27 #ifndef _LARGEFILE64_SOURCE
28 #define _LARGEFILE64_SOURCE
29 #endif
30
31 #include <sys/stat.h>
32 #include <sys/syscall.h>
33 #include <sys/types.h>
34 #include <fcntl.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <unistd.h>
38 #include <ctype.h>
39
40 // #include <linux/falloc.h>
41 #define FALLOC_FL_KEEP_SIZE 0x01
42 #define FALLOC_FL_PUNCH_HOLE 0x02 /* de-allocates range */
43 #define FALLOC_FL_COLLAPSE_RANGE 0x08
44 #define FALLOC_FL_ZERO_RANGE 0x10
45
usage(void)46 void usage(void)
47 {
48 printf("Usage: fallocate [-npt] [-o offset] -l length filename\n");
49 exit(EXIT_FAILURE);
50 }
51
52 #define EXABYTES(x) ((long long)(x) << 60)
53 #define PETABYTES(x) ((long long)(x) << 50)
54 #define TERABYTES(x) ((long long)(x) << 40)
55 #define GIGABYTES(x) ((long long)(x) << 30)
56 #define MEGABYTES(x) ((long long)(x) << 20)
57 #define KILOBYTES(x) ((long long)(x) << 10)
58
59 long long
cvtnum(char * s)60 cvtnum(char *s)
61 {
62 long long i;
63 char *sp;
64 int c;
65
66 i = strtoll(s, &sp, 0);
67 if (i == 0 && sp == s)
68 return -1LL;
69 if (*sp == '\0')
70 return i;
71 if (sp[1] != '\0')
72 return -1LL;
73
74 c = tolower(*sp);
75 switch (c) {
76 case 'k':
77 return KILOBYTES(i);
78 case 'm':
79 return MEGABYTES(i);
80 case 'g':
81 return GIGABYTES(i);
82 case 't':
83 return TERABYTES(i);
84 case 'p':
85 return PETABYTES(i);
86 case 'e':
87 return EXABYTES(i);
88 }
89
90 return -1LL;
91 }
92
main(int argc,char ** argv)93 int main(int argc, char **argv)
94 {
95 int fd;
96 char *fname;
97 int opt;
98 loff_t length = -2LL;
99 loff_t offset = 0;
100 int falloc_mode = 0;
101 int error;
102 int tflag = 0;
103
104 while ((opt = getopt(argc, argv, "npl:o:tzc")) != -1) {
105 switch(opt) {
106 case 'n':
107 /* do not change filesize */
108 falloc_mode = FALLOC_FL_KEEP_SIZE;
109 break;
110 case 'p':
111 /* punch mode */
112 falloc_mode = (FALLOC_FL_PUNCH_HOLE |
113 FALLOC_FL_KEEP_SIZE);
114 break;
115 case 'c':
116 /* collapse range mode */
117 falloc_mode = (FALLOC_FL_COLLAPSE_RANGE |
118 FALLOC_FL_KEEP_SIZE);
119 break;
120 case 'z':
121 /* zero range mode */
122 falloc_mode = (FALLOC_FL_ZERO_RANGE |
123 FALLOC_FL_KEEP_SIZE);
124 break;
125 case 'l':
126 length = cvtnum(optarg);
127 break;
128 case 'o':
129 offset = cvtnum(optarg);
130 break;
131 case 't':
132 tflag++;
133 break;
134 default:
135 usage();
136 }
137 }
138
139 if (length == -2LL) {
140 printf("Error: no length argument specified\n");
141 usage();
142 }
143
144 if (length <= 0) {
145 printf("Error: invalid length value specified\n");
146 usage();
147 }
148
149 if (offset < 0) {
150 printf("Error: invalid offset value specified\n");
151 usage();
152 }
153
154 if (tflag && (falloc_mode & FALLOC_FL_KEEP_SIZE)) {
155 printf("-n and -t options incompatible\n");
156 usage();
157 }
158
159 if (tflag && offset) {
160 printf("-n and -o options incompatible\n");
161 usage();
162 }
163
164 if (optind == argc) {
165 printf("Error: no filename specified\n");
166 usage();
167 }
168
169 fname = argv[optind++];
170
171 /* Should we create the file if it doesn't already exist? */
172 fd = open(fname, O_WRONLY|O_LARGEFILE);
173 if (fd < 0) {
174 perror("Error opening file");
175 exit(EXIT_FAILURE);
176 }
177
178 if (tflag)
179 error = ftruncate(fd, length);
180 else
181 error = syscall(SYS_fallocate, fd, falloc_mode, offset, length);
182
183 if (error < 0) {
184 perror("fallocate failed");
185 exit(EXIT_FAILURE);
186 }
187
188 close(fd);
189 return 0;
190 }
191