sys-utils/fstrim.c

   1 /*
   2  * fstrim.c -- discard the part (or whole) of mounted filesystem.
   3  *
   4  * Copyright (C) 2010 Red Hat, Inc. All rights reserved.
   5  * Written by Lukas Czerner <lczerner@redhat.com>
   6  *            Karel Zak <kzak@redhat.com>
   7  *
   8  * This program is free software: you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation, either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  *
  21  *
  22  * This program uses FITRIM ioctl to discard parts or the whole filesystem
  23  * online (mounted). You can specify range (start and length) to be
  24  * discarded, or simply discard whole filesystem.
  25  */
  26
  27 #include <string.h>
  28 #include <unistd.h>
  29 #include <stdlib.h>
  30 #include <stdio.h>
  31 #include <stdint.h>
  32 #include <fcntl.h>
  33 #include <limits.h>
  34 #include <getopt.h>
  35 #include <error.h>
  36 #include <errno.h>
  37
  38 #include <sys/ioctl.h>
  39 #include <sys/stat.h>
  40 #include <linux/fs.h>
  41
  42 #include "nls.h"
  43 #include "strutils.h"
  44 #include "c.h"
  45
  46 #ifndef FITRIM
  47 struct fstrim_range {
  48         uint64_t start;
  49         uint64_t len;
  50         uint64_t minlen;
  51 };
  52 #define FITRIM          _IOWR('X', 121, struct fstrim_range)
  53 #endif
  54
  55 static void __attribute__((__noreturn__)) usage(FILE *out)
  56 {
  57         fprintf(out, _("Usage: %s [options] <mount point>\n\nOptions:\n"),
  58                         program_invocation_short_name);
  59
  60         fprintf(out, _(
  61                 " -h, --help          this help\n"
  62                 " -o, --offset <num>  offset in bytes to discard from\n"
  63                 " -l, --length <num>  length of bytes to discard from the offset\n"
  64                 " -m, --minimum <num> minimum extent length to discard\n"
  65                 " -v, --verbose       print number of discarded bytes\n"));
  66
  67         fprintf(out, _("\nFor more information see fstrim(1).\n"));
  68
  69         exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
  70 }
  71
  72 int main(int argc, char **argv)
  73 {
  74         char *path;
  75         int c, fd, verbose = 0;
  76         struct fstrim_range range;
  77         struct stat sb;
  78
  79         struct option longopts[] = {
  80             { "help",      0, 0, 'h' },
  81             { "offset",    1, 0, 'o' },
  82             { "length",    1, 0, 'l' },
  83             { "minimum",   1, 0, 'm' },
  84             { "verbose",   0, 0, 'v' },
  85             { NULL,        0, 0, 0 }
  86         };
  87
  88         setlocale(LC_ALL, "");
  89         bindtextdomain(PACKAGE, LOCALEDIR);
  90         textdomain(PACKAGE);
  91
  92         memset(&range, 0, sizeof(range));
  93         range.len = ULLONG_MAX;
  94
  95         while ((c = getopt_long(argc, argv, "ho:l:m:v", longopts, NULL)) != -1) {
  96                 switch(c) {
  97                 case 'h':
  98                         usage(stdout);
  99                         break;
 100                 case 'l':
 101                         if (strtosize(optarg, &range.len))
 102                                 errx(EXIT_FAILURE,
 103                                      _("failed to parse length: %s"), optarg);
 104                         break;
 105                 case 'o':
 106                         if (strtosize(optarg, &range.start))
 107                                 errx(EXIT_FAILURE,
 108                                      _("failed to parse offset: %s"), optarg);
 109                         break;
 110                 case 'm':
 111                         if (strtosize(optarg, &range.minlen))
 112                                 errx(EXIT_FAILURE,
 113                                      _("failed to parse minimal extend length: %s"),
 114                                      optarg);
 115                         break;
 116                 case 'v':
 117                         verbose = 1;
 118                         break;
 119                 default:
 120                         usage(stderr);
 121                         break;
 122                 }
 123         }
 124
 125         if (optind == argc)
 126                 errx(EXIT_FAILURE, _("no mountpoint specified."));
 127
 128         path = argv[optind++];
 129
 130         if (optind != argc) {
 131                 warnx(_("unexpected number of arguments"));
 132                 usage(stderr);
 133         }
 134
 135         if (stat(path, &sb) == -1)
 136                 err(EXIT_FAILURE, _("%s: stat failed"), path);
 137         if (!S_ISDIR(sb.st_mode))
 138                 errx(EXIT_FAILURE, _("%s: not a directory"), path);
 139
 140         fd = open(path, O_RDONLY);
 141         if (fd < 0)
 142                 err(EXIT_FAILURE, _("%s: open failed"), path);
 143
 144         if (ioctl(fd, FITRIM, &range)) {
 145                 int errsv = errno;
 146                 close(fd);
 147                 error(EXIT_FAILURE, errsv, _("%s: FITRIM ioctl failed"), path);
 148         }
 149         if (verbose)
 150                 printf(_("%s: %" PRIu64 " bytes was trimmed\n"),
 151                                                 path, range.len);
 152         close(fd);
 153         return EXIT_SUCCESS;
 154 }