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         fputs(USAGE_HELP, out);
  51         fputs(USAGE_VERSION, out);
  52         fprintf(out, USAGE_MAN_TAIL("fsfreeze(8)"));
  53
  54         exit(EXIT_SUCCESS);
  55 }
  56
  57 int main(int argc, char **argv)
  58 {
  59         int fd = -1, c;
  60         int action = NOOP, rc = EXIT_FAILURE;
  61         char *path;
  62         struct stat sb;
  63
  64         static const struct option longopts[] = {
  65             { "help",      no_argument, NULL, 'h' },
  66             { "freeze",    no_argument, NULL, 'f' },
  67             { "unfreeze",  no_argument, NULL, 'u' },
  68             { "version",   no_argument, NULL, 'V' },
  69             { NULL, 0, NULL, 0 }
  70         };
  71
  72         static const ul_excl_t excl[] = {       /* rows and cols in ASCII order */
  73                 { 'f','u' },                    /* freeze, unfreeze */
  74                 { 0 }
  75         };
  76         int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
  77
  78         setlocale(LC_ALL, "");
  79         bindtextdomain(PACKAGE, LOCALEDIR);
  80         textdomain(PACKAGE);
  81         atexit(close_stdout);
  82
  83         while ((c = getopt_long(argc, argv, "hfuV", longopts, NULL)) != -1) {
  84
  85                 err_exclusive_options(c, longopts, excl, excl_st);
  86
  87                 switch(c) {
  88                 case 'h':
  89                         usage();
  90                         break;
  91                 case 'f':
  92                         action = FREEZE;
  93                         break;
  94                 case 'u':
  95                         action = UNFREEZE;
  96                         break;
  97                 case 'V':
  98                         printf(UTIL_LINUX_VERSION);
  99                         exit(EXIT_SUCCESS);
 100                 default:
 101                         errtryhelp(EXIT_FAILURE);
 102                 }
 103         }
 104
 105         if (action == NOOP)
 106                 errx(EXIT_FAILURE, _("neither --freeze or --unfreeze specified"));
 107         if (optind == argc)
 108                 errx(EXIT_FAILURE, _("no filename specified"));
 109         path = argv[optind++];
 110
 111         if (optind != argc) {
 112                 warnx(_("unexpected number of arguments"));
 113                 errtryhelp(EXIT_FAILURE);
 114         }
 115
 116         fd = open(path, O_RDONLY);
 117         if (fd < 0)
 118                 err(EXIT_FAILURE, _("cannot open %s"), path);
 119
 120         if (fstat(fd, &sb) == -1) {
 121                 warn(_("stat of %s failed"), path);
 122                 goto done;
 123         }
 124
 125         if (!S_ISDIR(sb.st_mode)) {
 126                 warnx(_("%s: is not a directory"), path);
 127                 goto done;
 128         }
 129
 130         switch (action) {
 131         case FREEZE:
 132                 if (ioctl(fd, FIFREEZE, 0)) {
 133                         warn(_("%s: freeze failed"), path);
 134                         goto done;
 135                 }
 136                 break;
 137         case UNFREEZE:
 138                 if (ioctl(fd, FITHAW, 0)) {
 139                         warn(_("%s: unfreeze failed"), path);
 140                         goto done;
 141                 }
 142                 break;
 143         default:
 144                 abort();
 145         }
 146
 147         rc = EXIT_SUCCESS;
 148 done:
 149         if (fd >= 0)
 150                 close(fd);
 151         return rc;
 152 }
 153