sys-utils/fallocate.c

   1 /*
   2  * fallocate - utility to use the fallocate system call
   3  *
   4  * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved.
   5  * Written by Eric Sandeen <sandeen@redhat.com>
   6  *            Karel Zak <kzak@redhat.com>
   7  *
   8  * cvtnum routine taken from xfsprogs,
   9  * Copyright (c) 2003-2005 Silicon Graphics, Inc.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License as
  13  * published by the Free Software Foundation.
  14  *
  15  * This program is distributed in the hope that it would be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  */
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <ctype.h>
  27 #include <errno.h>
  28 #include <fcntl.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <getopt.h>
  33 #include <err.h>
  34 #include <limits.h>
  35
  36 #ifndef HAVE_FALLOCATE
  37 # include <sys/syscall.h>
  38 #endif
  39
  40 #ifdef HAVE_LINUX_FALLOC_H
  41 # include <linux/falloc.h>      /* for FALLOC_FL_* flags */
  42 #else
  43 # define FALLOC_FL_KEEP_SIZE 1
  44 #endif
  45
  46 #include "nls.h"
  47 #include "strtosize.h"
  48
  49
  50 static void __attribute__((__noreturn__)) usage(FILE *out)
  51 {
  52         fprintf(out, _("Usage: %s [options] <filename>\n\nOptions:\n"),
  53                         program_invocation_short_name);
  54
  55         fprintf(out, _(
  56                 " -h, --help          this help\n"
  57                 " -n, --keep-size     don't modify the length of the file\n"
  58                 " -o, --offset <num>  offset of the allocation, in bytes\n"
  59                 " -l, --length <num>  length of the allocation, in bytes\n"));
  60
  61         fprintf(out, _("\nFor more information see fallocate(1).\n"));
  62
  63         exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
  64 }
  65
  66 static loff_t cvtnum(char *s)
  67 {
  68         uintmax_t x;
  69
  70         if (strtosize(s, &x))
  71                 return -1LL;
  72
  73         return x;
  74 }
  75
  76 int main(int argc, char **argv)
  77 {
  78         char    *fname;
  79         int     c;
  80         int     error;
  81         int     fd;
  82         int     mode = 0;
  83         loff_t  length = -2LL;
  84         loff_t  offset = 0;
  85
  86         struct option longopts[] = {
  87             { "help",      0, 0, 'h' },
  88             { "keep-size", 0, 0, 'n' },
  89             { "offset",    1, 0, 'o' },
  90             { "lenght",    1, 0, 'l' },
  91             { NULL,        0, 0, 0 }
  92         };
  93
  94         setlocale(LC_ALL, "");
  95         bindtextdomain(PACKAGE, LOCALEDIR);
  96         textdomain(PACKAGE);
  97
  98         while ((c = getopt_long(argc, argv, "hnl:o:", longopts, NULL)) != -1) {
  99                 switch(c) {
 100                 case 'h':
 101                         usage(stdout);
 102                         break;
 103                 case 'n':
 104                         mode |= FALLOC_FL_KEEP_SIZE;
 105                         break;
 106                 case 'l':
 107                         length = cvtnum(optarg);
 108                         break;
 109                 case 'o':
 110                         offset = cvtnum(optarg);
 111                         break;
 112                 default:
 113                         usage(stderr);
 114                         break;
 115                 }
 116         }
 117
 118         if (length == -2LL)
 119                 errx(EXIT_FAILURE, _("no length argument specified"));
 120         if (length <= 0)
 121                 errx(EXIT_FAILURE, _("invalid length value specified"));
 122         if (offset < 0)
 123                 errx(EXIT_FAILURE, _("invalid offset value specified"));
 124         if (optind == argc)
 125                 errx(EXIT_FAILURE, _("no filename specified."));
 126
 127         fname = argv[optind++];
 128
 129         if (optind != argc) {
 130                 warnx(_("unexpected number of arguments"));
 131                 usage(stderr);
 132         }
 133
 134         fd = open(fname, O_WRONLY|O_CREAT, 0644);
 135         if (fd < 0)
 136                 err(EXIT_FAILURE, _("%s: open failed"), fname);
 137
 138 #ifdef HAVE_FALLOCATE
 139         error = fallocate(fd, mode, offset, length);
 140 #else
 141         error = syscall(SYS_fallocate, fd, mode, offset, length);
 142 #endif
 143         /*
 144          * EOPNOTSUPP: The FALLOC_FL_KEEP_SIZE is unsupported
 145          * ENOSYS: The filesystem does not support sys_fallocate
 146          */
 147         if (error < 0) {
 148                 if ((mode & FALLOC_FL_KEEP_SIZE) && errno == EOPNOTSUPP)
 149                         errx(EXIT_FAILURE,
 150                                 _("keep size mode (-n option) unsupported"));
 151                 err(EXIT_FAILURE, _("%s: fallocate failed"), fname);
 152         }
 153
 154         close(fd);
 155         return EXIT_SUCCESS;
 156 }