sys-utils/blkdiscard.c

   1 /*
   2  * blkdiscard.c -- discard the part (or whole) of the block device.
   3  *
   4  * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
   5  * Written by Lukas Czerner <lczerner@redhat.com>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  *
  20  * This program uses BLKDISCARD ioctl to discard part or the whole block
  21  * device if the device supports it. You can specify range (start and
  22  * length) to be discarded, or simply discard the whole device.
  23  */
  24
  25
  26 #include <string.h>
  27 #include <unistd.h>
  28 #include <stdlib.h>
  29 #include <stdio.h>
  30 #include <stdint.h>
  31 #include <fcntl.h>
  32 #include <limits.h>
  33 #include <getopt.h>
  34 #include <time.h>
  35
  36 #include <sys/ioctl.h>
  37 #include <sys/stat.h>
  38 #include <sys/time.h>
  39 #include <linux/fs.h>
  40
  41 #include "nls.h"
  42 #include "strutils.h"
  43 #include "c.h"
  44 #include "closestream.h"
  45 #include "monotonic.h"
  46
  47 #ifndef BLKDISCARD
  48 # define BLKDISCARD     _IO(0x12,119)
  49 #endif
  50
  51 #ifndef BLKSECDISCARD
  52 # define BLKSECDISCARD  _IO(0x12,125)
  53 #endif
  54
  55 #ifndef BLKZEROOUT
  56 # define BLKZEROOUT     _IO(0x12,127)
  57 #endif
  58
  59 enum {
  60         ACT_DISCARD = 0,        /* default */
  61         ACT_ZEROOUT,
  62         ACT_SECURE
  63 };
  64
  65 static void print_stats(int act, char *path, uint64_t stats[])
  66 {
  67         switch (act) {
  68         case ACT_ZEROOUT:
  69                 printf(_("%s: Zero-filled %" PRIu64 " bytes from the offset %" PRIu64"\n"), \
  70                         path, stats[1], stats[0]);
  71                 break;
  72         case ACT_SECURE:
  73         case ACT_DISCARD:
  74                 printf(_("%s: Discarded %" PRIu64 " bytes from the offset %" PRIu64"\n"), \
  75                         path, stats[1], stats[0]);
  76                 break;
  77         }
  78 }
  79
  80 static void __attribute__((__noreturn__)) usage(void)
  81 {
  82         FILE *out = stdout;
  83         fputs(USAGE_HEADER, out);
  84         fprintf(out,
  85               _(" %s [options] <device>\n"), program_invocation_short_name);
  86
  87         fputs(USAGE_SEPARATOR, out);
  88         fputs(_("Discard the content of sectors on a device.\n"), out);
  89
  90         fputs(USAGE_OPTIONS, out);
  91         fputs(_(" -f, --force         disable all checking\n"), out);
  92         fputs(_(" -o, --offset <num>  offset in bytes to discard from\n"), out);
  93         fputs(_(" -l, --length <num>  length of bytes to discard from the offset\n"), out);
  94         fputs(_(" -p, --step <num>    size of the discard iterations within the offset\n"), out);
  95         fputs(_(" -s, --secure        perform secure discard\n"), out);
  96         fputs(_(" -z, --zeroout       zero-fill rather than discard\n"), out);
  97         fputs(_(" -v, --verbose       print aligned length and offset\n"), out);
  98
  99         fputs(USAGE_SEPARATOR, out);
 100         printf(USAGE_HELP_OPTIONS(21));
 101
 102         printf(USAGE_MAN_TAIL("blkdiscard(8)"));
 103         exit(EXIT_SUCCESS);
 104 }
 105
 106
 107 int main(int argc, char **argv)
 108 {
 109         char *path;
 110         int c, fd, verbose = 0, secsize, force = 0;
 111         uint64_t end, blksize, step, range[2], stats[2];
 112         struct stat sb;
 113         struct timeval now, last;
 114         int act = ACT_DISCARD;
 115
 116         static const struct option longopts[] = {
 117             { "help",      no_argument,       NULL, 'h' },
 118             { "version",   no_argument,       NULL, 'V' },
 119             { "offset",    required_argument, NULL, 'o' },
 120             { "force",     no_argument,       NULL, 'f' },
 121             { "length",    required_argument, NULL, 'l' },
 122             { "step",      required_argument, NULL, 'p' },
 123             { "secure",    no_argument,       NULL, 's' },
 124             { "verbose",   no_argument,       NULL, 'v' },
 125             { "zeroout",   no_argument,       NULL, 'z' },
 126             { NULL, 0, NULL, 0 }
 127         };
 128
 129         setlocale(LC_ALL, "");
 130         bindtextdomain(PACKAGE, LOCALEDIR);
 131         textdomain(PACKAGE);
 132         close_stdout_atexit();
 133
 134         range[0] = 0;
 135         range[1] = ULLONG_MAX;
 136         step = 0;
 137
 138         while ((c = getopt_long(argc, argv, "hfVsvo:l:p:z", longopts, NULL)) != -1) {
 139                 switch(c) {
 140                 case 'f':
 141                         force = 1;
 142                         break;
 143                 case 'l':
 144                         range[1] = strtosize_or_err(optarg,
 145                                         _("failed to parse length"));
 146                         break;
 147                 case 'o':
 148                         range[0] = strtosize_or_err(optarg,
 149                                         _("failed to parse offset"));
 150                         break;
 151                 case 'p':
 152                         step = strtosize_or_err(optarg,
 153                                         _("failed to parse step"));
 154                         break;
 155                 case 's':
 156                         act = ACT_SECURE;
 157                         break;
 158                 case 'v':
 159                         verbose = 1;
 160                         break;
 161                 case 'z':
 162                         act = ACT_ZEROOUT;
 163                         break;
 164
 165                 case 'h':
 166                         usage();
 167                 case 'V':
 168                         print_version(EXIT_SUCCESS);
 169                 default:
 170                         errtryhelp(EXIT_FAILURE);
 171                 }
 172         }
 173
 174         if (optind == argc)
 175                 errx(EXIT_FAILURE, _("no device specified"));
 176
 177         path = argv[optind++];
 178
 179         if (optind != argc) {
 180                 warnx(_("unexpected number of arguments"));
 181                 errtryhelp(EXIT_FAILURE);
 182         }
 183
 184         fd = open(path, O_WRONLY | (force ? 0 : O_EXCL));
 185         if (fd < 0)
 186                 err(EXIT_FAILURE, _("cannot open %s"), path);
 187
 188         if (fstat(fd, &sb) == -1)
 189                 err(EXIT_FAILURE, _("stat of %s failed"), path);
 190         if (!S_ISBLK(sb.st_mode))
 191                 errx(EXIT_FAILURE, _("%s: not a block device"), path);
 192
 193         if (ioctl(fd, BLKGETSIZE64, &blksize))
 194                 err(EXIT_FAILURE, _("%s: BLKGETSIZE64 ioctl failed"), path);
 195         if (ioctl(fd, BLKSSZGET, &secsize))
 196                 err(EXIT_FAILURE, _("%s: BLKSSZGET ioctl failed"), path);
 197
 198         /* check offset alignment to the sector size */
 199         if (range[0] % secsize)
 200                 errx(EXIT_FAILURE, _("%s: offset %" PRIu64 " is not aligned "
 201                          "to sector size %i"), path, range[0], secsize);
 202
 203         /* is the range end behind the end of the device ?*/
 204         if (range[0] > blksize)
 205                 errx(EXIT_FAILURE, _("%s: offset is greater than device size"), path);
 206         end = range[0] + range[1];
 207         if (end < range[0] || end > blksize)
 208                 end = blksize;
 209
 210         range[1] = (step > 0) ? step : end - range[0];
 211
 212         /* check length alignment to the sector size */
 213         if (range[1] % secsize)
 214                 errx(EXIT_FAILURE, _("%s: length %" PRIu64 " is not aligned "
 215                          "to sector size %i"), path, range[1], secsize);
 216
 217         stats[0] = range[0], stats[1] = 0;
 218         gettime_monotonic(&last);
 219
 220         for (/* nothing */; range[0] < end; range[0] += range[1]) {
 221                 if (range[0] + range[1] > end)
 222                         range[1] = end - range[0];
 223
 224                 switch (act) {
 225                 case ACT_ZEROOUT:
 226                         if (ioctl(fd, BLKZEROOUT, &range))
 227                                  err(EXIT_FAILURE, _("%s: BLKZEROOUT ioctl failed"), path);
 228                         break;
 229                 case ACT_SECURE:
 230                         if (ioctl(fd, BLKSECDISCARD, &range))
 231                                 err(EXIT_FAILURE, _("%s: BLKSECDISCARD ioctl failed"), path);
 232                         break;
 233                 case ACT_DISCARD:
 234                         if (ioctl(fd, BLKDISCARD, &range))
 235                                 err(EXIT_FAILURE, _("%s: BLKDISCARD ioctl failed"), path);
 236                         break;
 237                 }
 238
 239                 stats[1] += range[1];
 240
 241                 /* reporting progress at most once per second */
 242                 if (verbose && step) {
 243                         gettime_monotonic(&now);
 244                         if (now.tv_sec > last.tv_sec &&
 245                             (now.tv_usec >= last.tv_usec || now.tv_sec > last.tv_sec + 1)) {
 246                                 print_stats(act, path, stats);
 247                                 stats[0] += stats[1], stats[1] = 0;
 248                                 last = now;
 249                         }
 250                 }
 251         }
 252
 253         if (verbose && stats[1])
 254                 print_stats(act, path, stats);
 255
 256         close(fd);
 257         return EXIT_SUCCESS;
 258 }