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 'h':
  88                         usage();
  89                         break;
  90                 case 'f':
  91                         action = FREEZE;
  92                         break;
  93                 case 'u':
  94                         action = UNFREEZE;
  95                         break;
  96                 case 'V':
  97                         printf(UTIL_LINUX_VERSION);
  98                         exit(EXIT_SUCCESS);
  99                 default:
 100                         errtryhelp(EXIT_FAILURE);
 101                 }
 102         }
 103
 104         if (action == NOOP)
 105                 errx(EXIT_FAILURE, _("neither --freeze or --unfreeze specified"));
 106         if (optind == argc)
 107                 errx(EXIT_FAILURE, _("no filename specified"));
 108         path = argv[optind++];
 109
 110         if (optind != argc) {
 111                 warnx(_("unexpected number of arguments"));
 112                 errtryhelp(EXIT_FAILURE);
 113         }
 114
 115         fd = open(path, O_RDONLY);
 116         if (fd < 0)
 117                 err(EXIT_FAILURE, _("cannot open %s"), path);
 118
 119         if (fstat(fd, &sb) == -1) {
 120                 warn(_("stat of %s failed"), path);
 121                 goto done;
 122         }
 123
 124         if (!S_ISDIR(sb.st_mode)) {
 125                 warnx(_("%s: is not a directory"), path);
 126                 goto done;
 127         }
 128
 129         switch (action) {
 130         case FREEZE:
 131                 if (ioctl(fd, FIFREEZE, 0)) {
 132                         warn(_("%s: freeze failed"), path);
 133                         goto done;
 134                 }
 135                 break;
 136         case UNFREEZE:
 137                 if (ioctl(fd, FITHAW, 0)) {
 138                         warn(_("%s: unfreeze failed"), path);
 139                         goto done;
 140                 }
 141                 break;
 142         default:
 143                 abort();
 144         }
 145
 146         rc = EXIT_SUCCESS;
 147 done:
 148         if (fd >= 0)
 149                 close(fd);
 150         return rc;
 151 }
 152