xref: /freebsd/usr.sbin/trim/trim.c (revision 6829dae12bb055451fa467da4589c43bd03b1e64)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2019 Eugene Grosbein <eugen@FreeBSD.org>.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  */
29 
30 #include <sys/disk.h>
31 #include <sys/ioctl.h>
32 #include <sys/stat.h>
33 
34 #include <err.h>
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <libutil.h>
38 #include <limits.h>
39 #include <paths.h>
40 #include <stdbool.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <sysexits.h>
44 #include <unistd.h>
45 
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 static off_t	getsize(const char *path);
50 static int	opendev(const char *path, int flags);
51 static int	trim(const char *path, off_t offset, off_t length, bool dryrun, bool verbose);
52 static void	usage(const char *name);
53 
54 int
55 main(int argc, char **argv)
56 {
57 	off_t offset, length;
58 	uint64_t usz;
59 	int ch, error;
60 	bool dryrun, verbose;
61 	char *fname, *name;
62 
63 	error = 0;
64 	length = offset = 0;
65 	name = argv[0];
66 	dryrun = verbose = true;
67 
68 	while ((ch = getopt(argc, argv, "Nfl:o:qr:v")) != -1)
69 		switch (ch) {
70 		case 'N':
71 			dryrun = true;
72 			verbose = true;
73 			break;
74 		case 'f':
75 			dryrun = false;
76 			break;
77 		case 'l':
78 		case 'o':
79 			if (expand_number(optarg, &usz) == -1 ||
80 					(off_t)usz < 0 || (usz == 0 && ch == 'l'))
81 				errx(EX_USAGE,
82 					"invalid %s of the region: %s",
83 					ch == 'o' ? "offset" : "length",
84 					optarg);
85 			if (ch == 'o')
86 				offset = (off_t)usz;
87 			else
88 				length = (off_t)usz;
89 			break;
90 		case 'q':
91 			verbose = false;
92 			break;
93 		case 'r':
94 			if ((length = getsize(optarg)) == 0)
95 				errx(EX_USAGE,
96 					"invalid zero length reference file"
97 					" for the region: %s", optarg);
98 			break;
99 		case 'v':
100 			verbose = true;
101 			break;
102 		default:
103 			usage(name);
104 			/* NOTREACHED */
105 		}
106 
107 	argv += optind;
108 	argc -= optind;
109 
110 	if (argc < 1)
111 		usage(name);
112 
113 	while ((fname = *argv++) != NULL)
114 		if (trim(fname, offset, length, dryrun, verbose) < 0)
115 			error++;
116 
117 	return (error ? EXIT_FAILURE : EXIT_SUCCESS);
118 }
119 
120 static int
121 opendev(const char *path, int flags)
122 {
123 	int fd;
124 	char *tstr;
125 
126 	if ((fd = open(path, flags)) < 0) {
127 		if (errno == ENOENT && path[0] != '/') {
128 			if (asprintf(&tstr, "%s%s", _PATH_DEV, path) < 0)
129 				errx(EX_OSERR, "no memory");
130 			fd = open(tstr, flags);
131 			free(tstr);
132 		}
133 	}
134 
135 	if (fd < 0)
136 		err(EX_NOINPUT, "open failed: %s", path);
137 
138 	return (fd);
139 }
140 
141 static off_t
142 getsize(const char *path)
143 {
144 	struct stat sb;
145 	off_t mediasize;
146 	int fd;
147 
148 	fd = opendev(path, O_RDONLY | O_DIRECT);
149 
150 	if (fstat(fd, &sb) < 0)
151 		err(EX_IOERR, "fstat failed: %s", path);
152 
153 	if (S_ISREG(sb.st_mode) || S_ISDIR(sb.st_mode)) {
154 		close(fd);
155 		return (sb.st_size);
156 	}
157 
158 	if (!S_ISCHR(sb.st_mode) && !S_ISBLK(sb.st_mode))
159 		errx(EX_DATAERR,
160 			"invalid type of the file "
161 			"(not regular, directory nor special device): %s",
162 			path);
163 
164 	if (ioctl(fd, DIOCGMEDIASIZE, &mediasize) < 0)
165 		err(EX_UNAVAILABLE,
166 			"ioctl(DIOCGMEDIASIZE) failed, probably not a disk: "
167 			"%s", path);
168 
169 	close(fd);
170 	return (mediasize);
171 }
172 
173 static int
174 trim(const char *path, off_t offset, off_t length, bool dryrun, bool verbose)
175 {
176 	off_t arg[2];
177 	int error, fd;
178 
179 	if (length == 0)
180 		length = getsize(path);
181 
182 	if (verbose)
183 		printf("trim %s offset %ju length %ju\n",
184 		    path, (uintmax_t)offset, (uintmax_t)length);
185 
186 	if (dryrun) {
187 		printf("dry run: add -f to actually perform the operation\n");
188 		return (0);
189 	}
190 
191 	fd = opendev(path, O_WRONLY | O_DIRECT);
192 	arg[0] = offset;
193 	arg[1] = length;
194 
195 	error = ioctl(fd, DIOCGDELETE, arg);
196 	if (error < 0)
197 		warn("ioctl(DIOCGDELETE) failed: %s", path);
198 
199 	close(fd);
200 	return (error);
201 }
202 
203 static void
204 usage(const char *name)
205 {
206 	(void)fprintf(stderr,
207 	    "usage: %s [-[lo] offset[K|k|M|m|G|g|T|t]] [-r rfile] [-Nfqv] device ...\n",
208 	    name);
209 	exit(EX_USAGE);
210 }
211