g_label_reiserfs.c revision 148978 
1/*-
2 * Copyright (c) 2005 Stanislav Sedov
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 AUTHOR 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 AUTHOR 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/sys/geom/label/g_label_reiserfs.c 148978 2005-08-12 00:27:45Z pjd $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/malloc.h>
34
35#include <geom/geom.h>
36#include <geom/label/g_label.h>
37
38#define REISERFS_NEW_DISK_OFFSET 64 * 1024
39#define REISERFS_OLD_DISK_OFFSET 8 * 1024
40#define REISERFS_SUPER_MAGIC	"ReIsEr"
41
42typedef struct resiserfs_sb {
43	uint8_t		fake1[52];
44	char		s_magic[10];
45	uint8_t		fake2[10];
46	uint16_t	s_version;
47	uint8_t		fake3[26];
48	char		s_volume_name[16];
49} reiserfs_sb_t;
50
51static reiserfs_sb_t *
52g_label_reiserfs_read_super(struct g_consumer *cp, off_t offset, off_t len)
53{
54	reiserfs_sb_t *fs;
55
56	fs = (reiserfs_sb_t *)g_read_data(cp, offset, len, NULL);
57	if (fs == NULL)
58		return (NULL);
59
60	if (strncmp(fs->s_magic, REISERFS_SUPER_MAGIC,
61	    strlen(REISERFS_SUPER_MAGIC)) != 0) {
62		g_free(fs);
63		return (NULL);
64	}
65
66	return (fs);
67}
68
69static void
70g_label_reiserfs_taste(struct g_consumer *cp, char *label, size_t size)
71{
72	struct g_provider *pp;
73	reiserfs_sb_t *fs;
74
75	g_topology_assert_not();
76	pp = cp->provider;
77	label[0] = '\0';
78
79	/* Try old format */
80	fs = g_label_reiserfs_read_super(cp, REISERFS_OLD_DISK_OFFSET,
81	    pp->sectorsize);
82	if (fs == NULL) {
83		/* Try new format */
84		fs = g_label_reiserfs_read_super(cp, REISERFS_NEW_DISK_OFFSET,
85		    pp->sectorsize);
86	}
87	if (fs == NULL)
88		return;
89
90	/* Check version */
91	if (fs->s_version == 2) {
92		G_LABEL_DEBUG(1, "reiserfs file system detected on %s.",
93		    pp->name);
94	} else {
95		goto exit_free;
96	}
97
98	/* Check for volume label */
99	if (fs->s_volume_name[0] == '\0')
100		goto exit_free;
101
102	/* Terminate label */
103	fs->s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0';
104	strlcpy(label, fs->s_volume_name, size);
105
106exit_free:
107	g_free(fs);
108}
109
110const struct g_label_desc g_label_reiserfs = {
111	.ld_taste = g_label_reiserfs_taste,
112	.ld_dir = "reiserfs"
113};
114