geom_util.c revision 169299 
1/*-
2 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/lib/libgeom/geom_util.c 169299 2007-05-06 01:17:46Z pjd $");
29
30#include <sys/param.h>
31#include <sys/disk.h>
32#include <sys/stat.h>
33
34#include <stdio.h>
35#include <fcntl.h>
36#include <errno.h>
37#include <stdint.h>
38#include <unistd.h>
39#include <string.h>
40#include <stdlib.h>
41#include <paths.h>
42
43#include <libgeom.h>
44
45/*
46 * Open the given provider and at least check if this is a block device.
47 */
48int
49g_open(const char *name, int write)
50{
51	char path[MAXPATHLEN];
52	int fd;
53
54	if (name[0] == '/')
55		strlcpy(path, name, sizeof(path));
56	else
57		snprintf(path, sizeof(path), "%s%s", _PATH_DEV, name);
58
59	fd = open(path, write ? O_RDWR : O_RDONLY);
60	if (fd == -1)
61		return (-1);
62	/* Let try to get sectorsize, which will prove it is a GEOM provider. */
63	if (g_sectorsize(fd) == -1) {
64		close(fd);
65		errno = EFTYPE;
66		return (-1);
67	}
68	return (fd);
69}
70
71int
72g_close(int fd)
73{
74
75	return (close(fd));
76}
77
78static int
79g_ioctl_arg(int fd, unsigned long cmd, void *arg)
80{
81	int ret;
82
83	if (arg != NULL)
84		ret = ioctl(fd, cmd, arg);
85	else
86		ret = ioctl(fd, cmd);
87	return (ret >= 0 ? 0 : -1);
88}
89
90static int
91g_ioctl(int fd, unsigned long cmd)
92{
93
94	return (g_ioctl_arg(fd, cmd, NULL));
95}
96
97/*
98 * Return media size of the given provider.
99 */
100off_t
101g_mediasize(int fd)
102{
103	off_t mediasize;
104
105	if (g_ioctl_arg(fd, DIOCGMEDIASIZE, &mediasize) == -1)
106		mediasize = -1;
107	return (mediasize);
108}
109
110/*
111 * Return sector size of the given provider.
112 */
113ssize_t
114g_sectorsize(int fd)
115{
116	u_int sectorsize;
117
118	if (g_ioctl_arg(fd, DIOCGSECTORSIZE, &sectorsize) == -1)
119		return (-1);
120	return ((ssize_t)sectorsize);
121}
122
123/*
124 * Call BIO_FLUSH for the given provider.
125 */
126int
127g_flush(int fd)
128{
129
130	return (g_ioctl(fd, DIOCGFLUSH));
131}
132
133/*
134 * Call BIO_DELETE for the given range.
135 */
136int
137g_delete(int fd, off_t offset, off_t length)
138{
139	off_t arg[2];
140
141	arg[0] = offset;
142	arg[1] = length;
143	return (g_ioctl_arg(fd, DIOCGDELETE, arg));
144}
145
146/*
147 * Return ID of the given provider.
148 */
149int
150g_get_ident(int fd, char *ident, size_t size)
151{
152	char lident[DISK_IDENT_SIZE];
153
154	if (g_ioctl_arg(fd, DIOCGIDENT, lident) == -1)
155		return (-1);
156	if (lident[0] == '\0') {
157		errno = ENOENT;
158		return (-1);
159	}
160	if (strlcpy(ident, lident, size) >= size) {
161		errno = ENAMETOOLONG;
162		return (-1);
163	}
164	return (0);
165}
166
167/*
168 * Return name of the provider, which has the given ID.
169 */
170int
171g_get_name(const char *ident, char *name, size_t size)
172{
173	int fd;
174
175	fd = g_open_by_ident(ident, 0, name, size);
176	if (fd == -1)
177		return (-1);
178	g_close(fd);
179	return (0);
180}
181
182/*
183 * Find provider name by the given ID.
184 */
185int
186g_open_by_ident(const char *ident, int write, char *name, size_t size)
187{
188	char lident[DISK_IDENT_SIZE];
189	struct gmesh mesh;
190	struct gclass *mp;
191	struct ggeom *gp;
192	struct gprovider *pp;
193	int error, fd;
194
195	error = geom_gettree(&mesh);
196	if (error != 0) {
197		errno = error;
198		return (-1);
199	}
200
201	error = ENOENT;
202	fd = -1;
203
204	LIST_FOREACH(mp, &mesh.lg_class, lg_class) {
205		LIST_FOREACH(gp, &mp->lg_geom, lg_geom) {
206			LIST_FOREACH(pp, &gp->lg_provider, lg_provider) {
207				fd = g_open(pp->lg_name, write);
208				if (fd == -1)
209					continue;
210				if (g_get_ident(fd, lident,
211				    sizeof(lident)) == -1) {
212					g_close(fd);
213					continue;
214				}
215				if (strcmp(ident, lident) != 0) {
216					g_close(fd);
217					continue;
218				}
219				error = 0;
220				if (name != NULL && strlcpy(name, pp->lg_name,
221				    size) >= size) {
222					error = ENAMETOOLONG;
223					g_close(fd);
224				}
225				goto end;
226			}
227		}
228	}
229end:
230	geom_deletetree(&mesh);
231	if (error != 0) {
232		errno = error;
233		return (-1);
234	}
235	return (fd);
236}
237