diff options
Diffstat (limited to 'sys-utils/blkdiscard.c')
| -rw-r--r-- | sys-utils/blkdiscard.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/sys-utils/blkdiscard.c b/sys-utils/blkdiscard.c new file mode 100644 index 0000000..c19b67b --- /dev/null +++ b/sys-utils/blkdiscard.c @@ -0,0 +1,254 @@ +/* + * 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" +#include "monotonic.h" + +#ifndef BLKDISCARD +# define BLKDISCARD _IO(0x12,119) +#endif + +#ifndef BLKSECDISCARD +# define BLKSECDISCARD _IO(0x12,125) +#endif + +#ifndef BLKZEROOUT +# define BLKZEROOUT _IO(0x12,127) +#endif + +enum { + ACT_DISCARD = 0, /* default */ + ACT_ZEROOUT, + ACT_SECURE +}; + +static void print_stats(int act, char *path, uint64_t stats[]) +{ + switch (act) { + case ACT_ZEROOUT: + printf(_("%s: Zero-filled %" PRIu64 " bytes from the offset %" PRIu64"\n"), \ + path, stats[1], stats[0]); + break; + case ACT_SECURE: + case ACT_DISCARD: + printf(_("%s: Discarded %" PRIu64 " bytes from the offset %" PRIu64"\n"), \ + path, stats[1], stats[0]); + break; + } +} + +static void __attribute__((__noreturn__)) usage(void) +{ + FILE *out = stdout; + fputs(USAGE_HEADER, out); + fprintf(out, + _(" %s [options] <device>\n"), program_invocation_short_name); + + fputs(USAGE_SEPARATOR, out); + fputs(_("Discard the content of sectors on a device.\n"), out); + + fputs(USAGE_OPTIONS, out); + fputs(_(" -o, --offset <num> offset in bytes to discard from\n"), out); + fputs(_(" -l, --length <num> length of bytes to discard from the offset\n"), out); + fputs(_(" -p, --step <num> size of the discard iterations within the offset\n"), out); + fputs(_(" -s, --secure perform secure discard\n"), out); + fputs(_(" -z, --zeroout zero-fill rather than discard\n"), out); + fputs(_(" -v, --verbose print aligned length and offset\n"), out); + + fputs(USAGE_SEPARATOR, out); + printf(USAGE_HELP_OPTIONS(21)); + + printf(USAGE_MAN_TAIL("blkdiscard(8)")); + exit(EXIT_SUCCESS); +} + + +int main(int argc, char **argv) +{ + char *path; + int c, fd, verbose = 0, secsize; + uint64_t end, blksize, step, range[2], stats[2]; + struct stat sb; + struct timeval now, last; + int act = ACT_DISCARD; + + static const struct option longopts[] = { + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, 'V' }, + { "offset", required_argument, NULL, 'o' }, + { "length", required_argument, NULL, 'l' }, + { "step", required_argument, NULL, 'p' }, + { "secure", no_argument, NULL, 's' }, + { "verbose", no_argument, NULL, 'v' }, + { "zeroout", no_argument, NULL, 'z' }, + { NULL, 0, NULL, 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:z", longopts, NULL)) != -1) { + switch(c) { + case 'h': + usage(); + 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': + act = ACT_SECURE; + break; + case 'v': + verbose = 1; + break; + case 'z': + act = ACT_ZEROOUT; + break; + default: + errtryhelp(EXIT_FAILURE); + } + } + + if (optind == argc) + errx(EXIT_FAILURE, _("no device specified")); + + path = argv[optind++]; + + if (optind != argc) { + warnx(_("unexpected number of arguments")); + errtryhelp(EXIT_FAILURE); + } + + fd = open(path, O_WRONLY); + if (fd < 0) + err(EXIT_FAILURE, _("cannot open %s"), path); + + if (fstat(fd, &sb) == -1) + err(EXIT_FAILURE, _("stat of %s failed"), 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; + gettime_monotonic(&last); + + for (/* nothing */; range[0] < end; range[0] += range[1]) { + if (range[0] + range[1] > end) + range[1] = end - range[0]; + + switch (act) { + case ACT_ZEROOUT: + if (ioctl(fd, BLKZEROOUT, &range)) + err(EXIT_FAILURE, _("%s: BLKZEROOUT ioctl failed"), path); + break; + case ACT_SECURE: + if (ioctl(fd, BLKSECDISCARD, &range)) + err(EXIT_FAILURE, _("%s: BLKSECDISCARD ioctl failed"), path); + break; + case ACT_DISCARD: + if (ioctl(fd, BLKDISCARD, &range)) + err(EXIT_FAILURE, _("%s: BLKDISCARD ioctl failed"), path); + break; + } + + stats[1] += range[1]; + + /* reporting progress at most once per second */ + if (verbose && step) { + gettime_monotonic(&now); + if (now.tv_sec > last.tv_sec && + (now.tv_usec >= last.tv_usec || now.tv_sec > last.tv_sec + 1)) { + print_stats(act, path, stats); + stats[0] += stats[1], stats[1] = 0; + last = now; + } + } + } + + if (verbose && stats[1]) + print_stats(act, path, stats); + + close(fd); + return EXIT_SUCCESS; +} |