328 lines
8.4 KiB
C
328 lines
8.4 KiB
C
/*
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* blkdiscard.c -- discard the part (or whole) of the block device.
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*
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* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
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* Written by Lukas Czerner <lczerner@redhat.com>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* This program uses BLKDISCARD ioctl to discard part or the whole block
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* device if the device supports it. You can specify range (start and
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* length) to be discarded, or simply discard the whole device.
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*/
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#include <string.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <stdint.h>
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#include <fcntl.h>
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#include <limits.h>
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#include <getopt.h>
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#include <time.h>
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#include <sys/ioctl.h>
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#include <sys/stat.h>
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#include <sys/time.h>
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#include <linux/fs.h>
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#ifdef HAVE_LIBBLKID
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# include <blkid.h>
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#endif
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#include "nls.h"
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#include "strutils.h"
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#include "c.h"
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#include "closestream.h"
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#include "monotonic.h"
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#ifndef BLKDISCARD
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# define BLKDISCARD _IO(0x12,119)
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#endif
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#ifndef BLKSECDISCARD
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# define BLKSECDISCARD _IO(0x12,125)
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#endif
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#ifndef BLKZEROOUT
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# define BLKZEROOUT _IO(0x12,127)
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#endif
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enum {
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ACT_DISCARD = 0, /* default */
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ACT_ZEROOUT,
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ACT_SECURE
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};
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static void print_stats(int act, char *path, uint64_t stats[])
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{
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switch (act) {
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case ACT_ZEROOUT:
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printf(_("%s: Zero-filled %" PRIu64 " bytes from the offset %" PRIu64"\n"), \
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path, stats[1], stats[0]);
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break;
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case ACT_SECURE:
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case ACT_DISCARD:
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printf(_("%s: Discarded %" PRIu64 " bytes from the offset %" PRIu64"\n"), \
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path, stats[1], stats[0]);
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break;
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}
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}
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static void __attribute__((__noreturn__)) usage(void)
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{
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FILE *out = stdout;
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fputs(USAGE_HEADER, out);
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fprintf(out,
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_(" %s [options] <device>\n"), program_invocation_short_name);
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fputs(USAGE_SEPARATOR, out);
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fputs(_("Discard the content of sectors on a device.\n"), out);
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fputs(USAGE_OPTIONS, out);
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fputs(_(" -f, --force disable all checking\n"), out);
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fputs(_(" -o, --offset <num> offset in bytes to discard from\n"), out);
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fputs(_(" -l, --length <num> length of bytes to discard from the offset\n"), out);
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fputs(_(" -p, --step <num> size of the discard iterations within the offset\n"), out);
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fputs(_(" -s, --secure perform secure discard\n"), out);
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fputs(_(" -z, --zeroout zero-fill rather than discard\n"), out);
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fputs(_(" -v, --verbose print aligned length and offset\n"), out);
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fputs(USAGE_SEPARATOR, out);
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printf(USAGE_HELP_OPTIONS(21));
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fputs(USAGE_ARGUMENTS, out);
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printf(USAGE_ARG_SIZE(_("<num>")));
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printf(USAGE_MAN_TAIL("blkdiscard(8)"));
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exit(EXIT_SUCCESS);
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}
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#ifdef HAVE_LIBBLKID
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/*
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* Check existing signature on the open fd
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* Returns 0 signature found
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* 1 no signature
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* <0 error
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*/
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static int probe_device(int fd, char *path)
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{
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const char *type;
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blkid_probe pr = NULL;
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int ret = -1;
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pr = blkid_new_probe();
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if (!pr || blkid_probe_set_device(pr, fd, 0, 0))
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return ret;
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blkid_probe_enable_superblocks(pr, TRUE);
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blkid_probe_enable_partitions(pr, TRUE);
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ret = blkid_do_fullprobe(pr);
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if (ret)
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goto out;
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if (!blkid_probe_lookup_value(pr, "TYPE", &type, NULL)) {
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warnx("%s contains existing file system (%s).",path ,type);
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} else if (!blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL)) {
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warnx("%s contains existing partition (%s).",path ,type);
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} else {
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warnx("%s contains existing signature.", path);
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}
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out:
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blkid_free_probe(pr);
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return ret;
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}
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#endif /* HAVE_LIBBLKID */
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int main(int argc, char **argv)
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{
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char *path;
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int c, fd, verbose = 0, secsize, force = 0;
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uint64_t end, blksize, step, range[2], stats[2];
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struct stat sb;
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struct timeval now = { 0 }, last = { 0 };
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int act = ACT_DISCARD;
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static const struct option longopts[] = {
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{ "help", no_argument, NULL, 'h' },
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{ "version", no_argument, NULL, 'V' },
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{ "offset", required_argument, NULL, 'o' },
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{ "force", no_argument, NULL, 'f' },
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{ "length", required_argument, NULL, 'l' },
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{ "step", required_argument, NULL, 'p' },
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{ "secure", no_argument, NULL, 's' },
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{ "verbose", no_argument, NULL, 'v' },
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{ "zeroout", no_argument, NULL, 'z' },
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{ NULL, 0, NULL, 0 }
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};
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setlocale(LC_ALL, "");
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bindtextdomain(PACKAGE, LOCALEDIR);
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textdomain(PACKAGE);
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close_stdout_atexit();
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range[0] = 0;
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range[1] = ULLONG_MAX;
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step = 0;
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while ((c = getopt_long(argc, argv, "hfVsvo:l:p:z", longopts, NULL)) != -1) {
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switch(c) {
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case 'f':
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force = 1;
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break;
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case 'l':
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range[1] = strtosize_or_err(optarg,
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_("failed to parse length"));
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break;
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case 'o':
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range[0] = strtosize_or_err(optarg,
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_("failed to parse offset"));
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break;
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case 'p':
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step = strtosize_or_err(optarg,
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_("failed to parse step"));
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break;
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case 's':
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act = ACT_SECURE;
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break;
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case 'v':
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verbose = 1;
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break;
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case 'z':
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act = ACT_ZEROOUT;
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break;
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case 'h':
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usage();
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case 'V':
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print_version(EXIT_SUCCESS);
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default:
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errtryhelp(EXIT_FAILURE);
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}
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}
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if (optind == argc)
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errx(EXIT_FAILURE, _("no device specified"));
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path = argv[optind++];
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if (optind != argc) {
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warnx(_("unexpected number of arguments"));
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errtryhelp(EXIT_FAILURE);
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}
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fd = open(path, O_RDWR | (force ? 0 : O_EXCL));
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if (fd < 0)
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err(EXIT_FAILURE, _("cannot open %s"), path);
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if (fstat(fd, &sb) == -1)
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err(EXIT_FAILURE, _("stat of %s failed"), path);
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if (!S_ISBLK(sb.st_mode))
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errx(EXIT_FAILURE, _("%s: not a block device"), path);
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if (ioctl(fd, BLKGETSIZE64, &blksize))
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err(EXIT_FAILURE, _("%s: BLKGETSIZE64 ioctl failed"), path);
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if (ioctl(fd, BLKSSZGET, &secsize))
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err(EXIT_FAILURE, _("%s: BLKSSZGET ioctl failed"), path);
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/* check offset alignment to the sector size */
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if (range[0] % secsize)
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errx(EXIT_FAILURE, _("%s: offset %" PRIu64 " is not aligned "
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"to sector size %i"), path, range[0], secsize);
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/* is the range end behind the end of the device ?*/
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if (range[0] > blksize)
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errx(EXIT_FAILURE, _("%s: offset is greater than device size"), path);
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end = range[0] + range[1];
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if (end < range[0] || end > blksize)
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end = blksize;
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range[1] = (step > 0) ? step : end - range[0];
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/* check length alignment to the sector size */
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if (range[1] % secsize)
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errx(EXIT_FAILURE, _("%s: length %" PRIu64 " is not aligned "
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"to sector size %i"), path, range[1], secsize);
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#ifdef HAVE_LIBBLKID
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if (force)
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warnx(_("Operation forced, data will be lost!"));
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else {
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/* Check for existing signatures on the device */
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switch(probe_device(fd, path)) {
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case 0: /* signature detected */
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/*
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* Only require force in interactive mode to avoid
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* breaking existing scripts
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*/
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if (isatty(STDIN_FILENO)) {
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errx(EXIT_FAILURE,
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_("This is destructive operation, data will " \
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"be lost! Use the -f option to override."));
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}
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break;
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case 1: /* no signature */
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break;
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default: /* error */
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err(EXIT_FAILURE, _("failed to probe the device"));
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break;
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}
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}
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#endif /* HAVE_LIBBLKID */
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stats[0] = range[0], stats[1] = 0;
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gettime_monotonic(&last);
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for (/* nothing */; range[0] < end; range[0] += range[1]) {
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if (range[0] + range[1] > end)
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range[1] = end - range[0];
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switch (act) {
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case ACT_ZEROOUT:
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if (ioctl(fd, BLKZEROOUT, &range))
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err(EXIT_FAILURE, _("%s: BLKZEROOUT ioctl failed"), path);
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break;
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case ACT_SECURE:
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if (ioctl(fd, BLKSECDISCARD, &range))
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err(EXIT_FAILURE, _("%s: BLKSECDISCARD ioctl failed"), path);
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break;
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case ACT_DISCARD:
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if (ioctl(fd, BLKDISCARD, &range))
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err(EXIT_FAILURE, _("%s: BLKDISCARD ioctl failed"), path);
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break;
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}
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stats[1] += range[1];
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/* reporting progress at most once per second */
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if (verbose && step) {
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gettime_monotonic(&now);
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if (now.tv_sec > last.tv_sec &&
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(now.tv_usec >= last.tv_usec || now.tv_sec > last.tv_sec + 1)) {
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print_stats(act, path, stats);
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stats[0] += stats[1], stats[1] = 0;
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last = now;
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}
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}
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}
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if (verbose && stats[1])
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print_stats(act, path, stats);
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close(fd);
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return EXIT_SUCCESS;
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}
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