File: blkdiscard.c

package info (click to toggle)
util-linux 2.34-0.1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, sid
  • size: 46,508 kB
  • sloc: ansic: 129,594; sh: 15,590; yacc: 1,170; makefile: 397; xml: 369; python: 316; csh: 37; sed: 16; perl: 15
file content (253 lines) | stat: -rw-r--r-- 6,787 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
/*
 * 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);
	close_stdout_atexit();

	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 '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_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;
}