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("$FreeBSD$");
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 reiserfs_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)
53{
54	reiserfs_sb_t *fs;
55	u_int secsize;
56
57	secsize = cp->provider->sectorsize;
58
59	if ((offset % secsize) != 0)
60		return (NULL);
61
62	fs = (reiserfs_sb_t *)g_read_data(cp, offset, secsize, NULL);
63	if (fs == NULL)
64		return (NULL);
65
66	if (strncmp(fs->s_magic, REISERFS_SUPER_MAGIC,
67	    strlen(REISERFS_SUPER_MAGIC)) != 0) {
68		g_free(fs);
69		return (NULL);
70	}
71
72	return (fs);
73}
74
75static void
76g_label_reiserfs_taste(struct g_consumer *cp, char *label, size_t size)
77{
78	struct g_provider *pp;
79	reiserfs_sb_t *fs;
80
81	g_topology_assert_not();
82	pp = cp->provider;
83	label[0] = '\0';
84
85	/* Try old format */
86	fs = g_label_reiserfs_read_super(cp, REISERFS_OLD_DISK_OFFSET);
87	if (fs == NULL) {
88		/* Try new format */
89		fs = g_label_reiserfs_read_super(cp, REISERFS_NEW_DISK_OFFSET);
90	}
91	if (fs == NULL)
92		return;
93
94	/* Check version */
95	if (fs->s_version == 2) {
96		G_LABEL_DEBUG(1, "reiserfs file system detected on %s.",
97		    pp->name);
98	} else {
99		goto exit_free;
100	}
101
102	/* Check for volume label */
103	if (fs->s_volume_name[0] == '\0')
104		goto exit_free;
105
106	/* Terminate label */
107	fs->s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0';
108	strlcpy(label, fs->s_volume_name, size);
109
110exit_free:
111	g_free(fs);
112}
113
114struct g_label_desc g_label_reiserfs = {
115	.ld_taste = g_label_reiserfs_taste,
116	.ld_dir = "reiserfs",
117	.ld_enabled = 1
118};
119
120G_LABEL_INIT(reiserfs, g_label_reiserfs, "Create device nodes for REISERFS volumes");
121