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