summaryrefslogtreecommitdiffstats
path: root/sys-utils/blkdiscard.c
diff options
context:
space:
mode:
Diffstat (limited to 'sys-utils/blkdiscard.c')
-rw-r--r--sys-utils/blkdiscard.c327
1 files changed, 327 insertions, 0 deletions
diff --git a/sys-utils/blkdiscard.c b/sys-utils/blkdiscard.c
new file mode 100644
index 0000000..38240e8
--- /dev/null
+++ b/sys-utils/blkdiscard.c
@@ -0,0 +1,327 @@
+/*
+ * 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>
+
+#ifdef HAVE_LIBBLKID
+# include <blkid.h>
+#endif
+
+#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(_(" -f, --force disable all checking\n"), 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));
+
+ fputs(USAGE_ARGUMENTS, out);
+ printf(USAGE_ARG_SIZE(_("<num>")));
+
+ printf(USAGE_MAN_TAIL("blkdiscard(8)"));
+ exit(EXIT_SUCCESS);
+}
+
+#ifdef HAVE_LIBBLKID
+/*
+ * Check existing signature on the open fd
+ * Returns 0 signature found
+ * 1 no signature
+ * <0 error
+ */
+static int probe_device(int fd, char *path)
+{
+ const char *type;
+ blkid_probe pr = NULL;
+ int ret = -1;
+
+ pr = blkid_new_probe();
+ if (!pr || blkid_probe_set_device(pr, fd, 0, 0))
+ return ret;
+
+ blkid_probe_enable_superblocks(pr, TRUE);
+ blkid_probe_enable_partitions(pr, TRUE);
+
+ ret = blkid_do_fullprobe(pr);
+ if (ret)
+ goto out;
+
+ if (!blkid_probe_lookup_value(pr, "TYPE", &type, NULL)) {
+ warnx("%s contains existing file system (%s).",path ,type);
+ } else if (!blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL)) {
+ warnx("%s contains existing partition (%s).",path ,type);
+ } else {
+ warnx("%s contains existing signature.", path);
+ }
+
+out:
+ blkid_free_probe(pr);
+ return ret;
+}
+#endif /* HAVE_LIBBLKID */
+
+int main(int argc, char **argv)
+{
+ char *path;
+ int c, fd, verbose = 0, secsize, force = 0;
+ uint64_t end, blksize, step, range[2], stats[2];
+ struct stat sb;
+ struct timeval now = { 0 }, last = { 0 };
+ int act = ACT_DISCARD;
+
+ static const struct option longopts[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, 'V' },
+ { "offset", required_argument, NULL, 'o' },
+ { "force", no_argument, NULL, 'f' },
+ { "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);
+ close_stdout_atexit();
+
+ range[0] = 0;
+ range[1] = ULLONG_MAX;
+ step = 0;
+
+ while ((c = getopt_long(argc, argv, "hfVsvo:l:p:z", longopts, NULL)) != -1) {
+ switch(c) {
+ case 'f':
+ force = 1;
+ break;
+ 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;
+
+ case 'h':
+ usage();
+ case 'V':
+ print_version(EXIT_SUCCESS);
+ 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_RDWR | (force ? 0 : O_EXCL));
+ 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);
+#ifdef HAVE_LIBBLKID
+ if (force)
+ warnx(_("Operation forced, data will be lost!"));
+ else {
+ /* Check for existing signatures on the device */
+ switch(probe_device(fd, path)) {
+ case 0: /* signature detected */
+ /*
+ * Only require force in interactive mode to avoid
+ * breaking existing scripts
+ */
+ if (isatty(STDIN_FILENO)) {
+ errx(EXIT_FAILURE,
+ _("This is destructive operation, data will " \
+ "be lost! Use the -f option to override."));
+ }
+ break;
+ case 1: /* no signature */
+ break;
+ default: /* error */
+ err(EXIT_FAILURE, _("failed to probe the device"));
+ break;
+ }
+ }
+#endif /* HAVE_LIBBLKID */
+
+ 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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-21 15:05:16 +0000