sys-utils/fsfreeze.c

   1 /*
   2  * fsfreeze.c -- Filesystem freeze/unfreeze IO for Linux
   3  *
   4  * Copyright (C) 2010 Hajime Taira <htaira@redhat.com>
   5  *                    Masatake Yamato <yamato@redhat.com>
   6  *
   7  * This program is free software.  You can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation: either version 1 or
  10  * (at your option) any later version.
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <errno.h>
  16 #include <string.h>
  17 #include <fcntl.h>
  18 #include <linux/fs.h>
  19 #include <sys/ioctl.h>
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <getopt.h>
  23
  24 #include "c.h"
  25 #include "blkdev.h"
  26 #include "nls.h"
  27 #include "closestream.h"
  28 #include "optutils.h"
  29
  30 enum fs_operation {
  31         NOOP,
  32         FREEZE,
  33         UNFREEZE
  34 };
  35
  36 static void __attribute__((__noreturn__)) usage(void)
  37 {
  38         FILE *out = stdout;
  39         fputs(USAGE_HEADER, out);
  40         fprintf(out,
  41               _(" %s [options] <mountpoint>\n"), program_invocation_short_name);
  42
  43         fputs(USAGE_SEPARATOR, out);
  44         fputs(_("Suspend access to a filesystem.\n"), out);
  45
  46         fputs(USAGE_OPTIONS, out);
  47         fputs(_(" -f, --freeze      freeze the filesystem\n"), out);
  48         fputs(_(" -u, --unfreeze    unfreeze the filesystem\n"), out);
  49         fputs(USAGE_SEPARATOR, out);
  50         printf(USAGE_HELP_OPTIONS(19));
  51         printf(USAGE_MAN_TAIL("fsfreeze(8)"));
  52
  53         exit(EXIT_SUCCESS);
  54 }
  55
  56 int main(int argc, char **argv)
  57 {
  58         int fd = -1, c;
  59         int action = NOOP, rc = EXIT_FAILURE;
  60         char *path;
  61         struct stat sb;
  62
  63         static const struct option longopts[] = {
  64             { "help",      no_argument, NULL, 'h' },
  65             { "freeze",    no_argument, NULL, 'f' },
  66             { "unfreeze",  no_argument, NULL, 'u' },
  67             { "version",   no_argument, NULL, 'V' },
  68             { NULL, 0, NULL, 0 }
  69         };
  70
  71         static const ul_excl_t excl[] = {       /* rows and cols in ASCII order */
  72                 { 'f','u' },                    /* freeze, unfreeze */
  73                 { 0 }
  74         };
  75         int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
  76
  77         setlocale(LC_ALL, "");
  78         bindtextdomain(PACKAGE, LOCALEDIR);
  79         textdomain(PACKAGE);
  80         atexit(close_stdout);
  81
  82         while ((c = getopt_long(argc, argv, "hfuV", longopts, NULL)) != -1) {
  83
  84                 err_exclusive_options(c, longopts, excl, excl_st);
  85
  86                 switch(c) {
  87                 case 'f':
  88                         action = FREEZE;
  89                         break;
  90                 case 'u':
  91                         action = UNFREEZE;
  92                         break;
  93
  94                 case 'h':
  95                         usage();
  96                 case 'V':
  97                         print_version(EXIT_SUCCESS);
  98                 default:
  99                         errtryhelp(EXIT_FAILURE);
 100                 }
 101         }
 102
 103         if (action == NOOP)
 104                 errx(EXIT_FAILURE, _("neither --freeze or --unfreeze specified"));
 105         if (optind == argc)
 106                 errx(EXIT_FAILURE, _("no filename specified"));
 107         path = argv[optind++];
 108
 109         if (optind != argc) {
 110                 warnx(_("unexpected number of arguments"));
 111                 errtryhelp(EXIT_FAILURE);
 112         }
 113
 114         fd = open(path, O_RDONLY);
 115         if (fd < 0)
 116                 err(EXIT_FAILURE, _("cannot open %s"), path);
 117
 118         if (fstat(fd, &sb) == -1) {
 119                 warn(_("stat of %s failed"), path);
 120                 goto done;
 121         }
 122
 123         if (!S_ISDIR(sb.st_mode)) {
 124                 warnx(_("%s: is not a directory"), path);
 125                 goto done;
 126         }
 127
 128         switch (action) {
 129         case FREEZE:
 130                 if (ioctl(fd, FIFREEZE, 0)) {
 131                         warn(_("%s: freeze failed"), path);
 132                         goto done;
 133                 }
 134                 break;
 135         case UNFREEZE:
 136                 if (ioctl(fd, FITHAW, 0)) {
 137                         warn(_("%s: unfreeze failed"), path);
 138                         goto done;
 139                 }
 140                 break;
 141         default:
 142                 abort();
 143         }
 144
 145         rc = EXIT_SUCCESS;
 146 done:
 147         if (fd >= 0)
 148                 close(fd);
 149         return rc;
 150 }
 151