/*
* blkdiscard.c -- discard the part (or whole) of the block device.
*
* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
* Written by Lukas Czerner <lczerner@redhat.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* This program uses BLKDISCARD ioctl to discard part or the whole block
* device if the device supports it. You can specify range (start and
* length) to be discarded, or simply discard the whole device.
*/
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <fcntl.h>
#include <limits.h>
#include <getopt.h>
#include <time.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <linux/fs.h>
#include "nls.h"
#include "strutils.h"
#include "c.h"
#include "closestream.h"
#ifndef BLKDISCARD
#define BLKDISCARD _IO(0x12,119)
#endif
#ifndef BLKSECDISCARD
#define BLKSECDISCARD _IO(0x12,125)
#endif
#define print_stats(path, stats) \
printf(_("%s: Discarded %" PRIu64 " bytes from the " \
"offset %" PRIu64"\n"), path, stats[1], stats[0]);
static void __attribute__((__noreturn__)) usage(FILE *out)
{
fputs(USAGE_HEADER, out);
fprintf(out,
_(" %s [options] <device>\n"), program_invocation_short_name);
fputs(USAGE_OPTIONS, out);
fputs(_(" -o, --offset <num> offset in bytes to discard from\n"
" -l, --length <num> length of bytes to discard from the offset\n"
" -p, --step <num> size of the discard iterations within the offset\n"
" -s, --secure perform secure discard\n"
" -v, --verbose print aligned length and offset\n"),
out);
fputs(USAGE_SEPARATOR, out);
fputs(USAGE_HELP, out);
fputs(USAGE_VERSION, out);
fprintf(out, USAGE_MAN_TAIL("blkdiscard(8)"));
exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}
int main(int argc, char **argv)
{
char *path;
int c, fd, verbose = 0, secure = 0, secsize;
uint64_t end, blksize, step, range[2], stats[2];
struct stat sb;
struct timespec now, last;
static const struct option longopts[] = {
{ "help", 0, 0, 'h' },
{ "version", 0, 0, 'V' },
{ "offset", 1, 0, 'o' },
{ "length", 1, 0, 'l' },
{ "step", 1, 0, 'p' },
{ "secure", 0, 0, 's' },
{ "verbose", 0, 0, 'v' },
{ NULL, 0, 0, 0 }
};
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
atexit(close_stdout);
range[0] = 0;
range[1] = ULLONG_MAX;
step = 0;
while ((c = getopt_long(argc, argv, "hVsvo:l:p:", longopts, NULL)) != -1) {
switch(c) {
case 'h':
usage(stdout);
break;
case 'V':
printf(UTIL_LINUX_VERSION);
return EXIT_SUCCESS;
case 'l':
range[1] = strtosize_or_err(optarg,
_("failed to parse length"));
break;
case 'o':
range[0] = strtosize_or_err(optarg,
_("failed to parse offset"));
break;
case 'p':
step = strtosize_or_err(optarg,
_("failed to parse step"));
break;
case 's':
secure = 1;
break;
case 'v':
verbose = 1;
break;
default:
usage(stderr);
break;
}
}
if (optind == argc)
errx(EXIT_FAILURE, _("no device specified"));
path = argv[optind++];
if (optind != argc) {
warnx(_("unexpected number of arguments"));
usage(stderr);
}
fd = open(path, O_WRONLY);
if (fd < 0)
err(EXIT_FAILURE, _("cannot open %s"), path);
if (fstat(fd, &sb) == -1)
err(EXIT_FAILURE, _("stat failed %s"), path);
if (!S_ISBLK(sb.st_mode))
errx(EXIT_FAILURE, _("%s: not a block device"), path);
if (ioctl(fd, BLKGETSIZE64, &blksize))
err(EXIT_FAILURE, _("%s: BLKGETSIZE64 ioctl failed"), path);
if (ioctl(fd, BLKSSZGET, &secsize))
err(EXIT_FAILURE, _("%s: BLKSSZGET ioctl failed"), path);
/* check offset alignment to the sector size */
if (range[0] % secsize)
errx(EXIT_FAILURE, _("%s: offset %" PRIu64 " is not aligned "
"to sector size %i"), path, range[0], secsize);
/* is the range end behind the end of the device ?*/
if (range[0] > blksize)
errx(EXIT_FAILURE, _("%s: offset is greater than device size"), path);
end = range[0] + range[1];
if (end < range[0] || end > blksize)
end = blksize;
range[1] = (step > 0) ? step : end - range[0];
/* check length alignment to the sector size */
if (range[1] % secsize)
errx(EXIT_FAILURE, _("%s: length %" PRIu64 " is not aligned "
"to sector size %i"), path, range[1], secsize);
stats[0] = range[0], stats[1] = 0;
clock_gettime(CLOCK_MONOTONIC, &last);
for (range[0] = range[0]; range[0] < end; range[0] += range[1]) {
if (range[0] + range[1] > end)
range[1] = end - range[0];
if (secure) {
if (ioctl(fd, BLKSECDISCARD, &range))
err(EXIT_FAILURE, _("%s: BLKSECDISCARD ioctl failed"), path);
} else {
if (ioctl(fd, BLKDISCARD, &range))
err(EXIT_FAILURE, _("%s: BLKDISCARD ioctl failed"), path);
}
/* reporting progress */
if (verbose && step) {
clock_gettime(CLOCK_MONOTONIC, &now);
if (last.tv_sec < now.tv_sec) {
print_stats(path, stats);
stats[0] = range[0], stats[1] = 0;
last = now;
}
}
stats[1] += range[1];
}
if (verbose)
print_stats(path, stats);
close(fd);
return EXIT_SUCCESS;
}
