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(_(" -o, --offset <num>  offset in bytes to discard from\n"), out);
  92         fputs(_(" -l, --length <num>  length of bytes to discard from the offset\n"), out);
  93         fputs(_(" -p, --step <num>    size of the discard iterations within the offset\n"), out);
  94         fputs(_(" -s, --secure        perform secure discard\n"), out);
  95         fputs(_(" -z, --zeroout       zero-fill rather than discard\n"), out);
  96         fputs(_(" -v, --verbose       print aligned length and offset\n"), out);
  97
  98         fputs(USAGE_SEPARATOR, out);
  99         printf(USAGE_HELP_OPTIONS(21));
 100
 101         printf(USAGE_MAN_TAIL("blkdiscard(8)"));
 102         exit(EXIT_SUCCESS);
 103 }
 104
 105
 106 int main(int argc, char **argv)
 107 {
 108         char *path;
 109         int c, fd, verbose = 0, secsize;
 110         uint64_t end, blksize, step, range[2], stats[2];
 111         struct stat sb;
 112         struct timeval now, last;
 113         int act = ACT_DISCARD;
 114
 115         static const struct option longopts[] = {
 116             { "help",      no_argument,       NULL, 'h' },
 117             { "version",   no_argument,       NULL, 'V' },
 118             { "offset",    required_argument, NULL, 'o' },
 119             { "length",    required_argument, NULL, 'l' },
 120             { "step",      required_argument, NULL, 'p' },
 121             { "secure",    no_argument,       NULL, 's' },
 122             { "verbose",   no_argument,       NULL, 'v' },
 123             { "zeroout",   no_argument,       NULL, 'z' },
 124             { NULL, 0, NULL, 0 }
 125         };
 126
 127         setlocale(LC_ALL, "");
 128         bindtextdomain(PACKAGE, LOCALEDIR);
 129         textdomain(PACKAGE);
 130         close_stdout_atexit();
 131
 132         range[0] = 0;
 133         range[1] = ULLONG_MAX;
 134         step = 0;
 135
 136         while ((c = getopt_long(argc, argv, "hVsvo:l:p:z", longopts, NULL)) != -1) {
 137                 switch(c) {
 138                 case 'l':
 139                         range[1] = strtosize_or_err(optarg,
 140                                         _("failed to parse length"));
 141                         break;
 142                 case 'o':
 143                         range[0] = strtosize_or_err(optarg,
 144                                         _("failed to parse offset"));
 145                         break;
 146                 case 'p':
 147                         step = strtosize_or_err(optarg,
 148                                         _("failed to parse step"));
 149                         break;
 150                 case 's':
 151                         act = ACT_SECURE;
 152                         break;
 153                 case 'v':
 154                         verbose = 1;
 155                         break;
 156                 case 'z':
 157                         act = ACT_ZEROOUT;
 158                         break;
 159
 160                 case 'h':
 161                         usage();
 162                 case 'V':
 163                         print_version(EXIT_SUCCESS);
 164                 default:
 165                         errtryhelp(EXIT_FAILURE);
 166                 }
 167         }
 168
 169         if (optind == argc)
 170                 errx(EXIT_FAILURE, _("no device specified"));
 171
 172         path = argv[optind++];
 173
 174         if (optind != argc) {
 175                 warnx(_("unexpected number of arguments"));
 176                 errtryhelp(EXIT_FAILURE);
 177         }
 178
 179         fd = open(path, O_WRONLY);
 180         if (fd < 0)
 181                 err(EXIT_FAILURE, _("cannot open %s"), path);
 182
 183         if (fstat(fd, &sb) == -1)
 184                 err(EXIT_FAILURE, _("stat of %s failed"), path);
 185         if (!S_ISBLK(sb.st_mode))
 186                 errx(EXIT_FAILURE, _("%s: not a block device"), path);
 187
 188         if (ioctl(fd, BLKGETSIZE64, &blksize))
 189                 err(EXIT_FAILURE, _("%s: BLKGETSIZE64 ioctl failed"), path);
 190         if (ioctl(fd, BLKSSZGET, &secsize))
 191                 err(EXIT_FAILURE, _("%s: BLKSSZGET ioctl failed"), path);
 192
 193         /* check offset alignment to the sector size */
 194         if (range[0] % secsize)
 195                 errx(EXIT_FAILURE, _("%s: offset %" PRIu64 " is not aligned "
 196                          "to sector size %i"), path, range[0], secsize);
 197
 198         /* is the range end behind the end of the device ?*/
 199         if (range[0] > blksize)
 200                 errx(EXIT_FAILURE, _("%s: offset is greater than device size"), path);
 201         end = range[0] + range[1];
 202         if (end < range[0] || end > blksize)
 203                 end = blksize;
 204
 205         range[1] = (step > 0) ? step : end - range[0];
 206
 207         /* check length alignment to the sector size */
 208         if (range[1] % secsize)
 209                 errx(EXIT_FAILURE, _("%s: length %" PRIu64 " is not aligned "
 210                          "to sector size %i"), path, range[1], secsize);
 211
 212         stats[0] = range[0], stats[1] = 0;
 213         gettime_monotonic(&last);
 214
 215         for (/* nothing */; range[0] < end; range[0] += range[1]) {
 216                 if (range[0] + range[1] > end)
 217                         range[1] = end - range[0];
 218
 219                 switch (act) {
 220                 case ACT_ZEROOUT:
 221                         if (ioctl(fd, BLKZEROOUT, &range))
 222                                  err(EXIT_FAILURE, _("%s: BLKZEROOUT ioctl failed"), path);
 223                         break;
 224                 case ACT_SECURE:
 225                         if (ioctl(fd, BLKSECDISCARD, &range))
 226                                 err(EXIT_FAILURE, _("%s: BLKSECDISCARD ioctl failed"), path);
 227                         break;
 228                 case ACT_DISCARD:
 229                         if (ioctl(fd, BLKDISCARD, &range))
 230                                 err(EXIT_FAILURE, _("%s: BLKDISCARD ioctl failed"), path);
 231                         break;
 232                 }
 233
 234                 stats[1] += range[1];
 235
 236                 /* reporting progress at most once per second */
 237                 if (verbose && step) {
 238                         gettime_monotonic(&now);
 239                         if (now.tv_sec > last.tv_sec &&
 240                             (now.tv_usec >= last.tv_usec || now.tv_sec > last.tv_sec + 1)) {
 241                                 print_stats(act, path, stats);
 242                                 stats[0] += stats[1], stats[1] = 0;
 243                                 last = now;
 244                         }
 245                 }
 246         }
 247
 248         if (verbose && stats[1])
 249                 print_stats(act, path, stats);
 250
 251         close(fd);
 252         return EXIT_SUCCESS;
 253 }