1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2005 Stanislav Sedov
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 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36
37 #include <geom/geom.h>
38 #include <geom/geom_dbg.h>
39 #include <geom/label/g_label.h>
40
41 #define REISERFS_NEW_DISK_OFFSET 64 * 1024
42 #define REISERFS_OLD_DISK_OFFSET 8 * 1024
43 #define REISERFS_SUPER_MAGIC "ReIsEr"
44
45 typedef struct reiserfs_sb {
46 uint8_t fake1[52];
47 char s_magic[10];
48 uint8_t fake2[10];
49 uint16_t s_version;
50 uint8_t fake3[26];
51 char s_volume_name[16];
52 } reiserfs_sb_t;
53
54 static reiserfs_sb_t *
55 g_label_reiserfs_read_super(struct g_consumer *cp, off_t offset)
56 {
57 reiserfs_sb_t *fs;
58 u_int secsize;
59
60 secsize = cp->provider->sectorsize;
61
62 KASSERT(secsize != 0, ("Tasting a disk with 0 sectorsize"));
63 if (secsize < sizeof(*fs))
64 return (NULL);
65 if ((offset % secsize) != 0)
66 return (NULL);
67
68 fs = g_read_data(cp, offset, secsize, NULL);
69 if (fs == NULL)
70 return (NULL);
71
72 if (strncmp(fs->s_magic, REISERFS_SUPER_MAGIC,
73 strlen(REISERFS_SUPER_MAGIC)) != 0) {
74 g_free(fs);
75 return (NULL);
76 }
77
78 return (fs);
79 }
80
81 static void
82 g_label_reiserfs_taste(struct g_consumer *cp, char *label, size_t size)
83 {
84 struct g_provider *pp;
85 reiserfs_sb_t *fs;
86
87 g_topology_assert_not();
88 pp = cp->provider;
89 label[0] = '\0';
90
91 /* Try old format */
92 fs = g_label_reiserfs_read_super(cp, REISERFS_OLD_DISK_OFFSET);
93 if (fs == NULL) {
94 /* Try new format */
95 fs = g_label_reiserfs_read_super(cp, REISERFS_NEW_DISK_OFFSET);
96 }
97 if (fs == NULL)
98 return;
99
100 /* Check version */
101 if (fs->s_version == 2) {
102 G_LABEL_DEBUG(1, "reiserfs file system detected on %s.",
103 pp->name);
104 } else {
105 goto exit_free;
106 }
107
108 /* Check for volume label */
109 if (fs->s_volume_name[0] == '\0')
110 goto exit_free;
111
112 /* Terminate label */
113 fs->s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0';
114 strlcpy(label, fs->s_volume_name, size);
115
116 exit_free:
117 g_free(fs);
118 }
119
120 struct g_label_desc g_label_reiserfs = {
121 .ld_taste = g_label_reiserfs_taste,
122 .ld_dirprefix = "reiserfs/",
123 .ld_enabled = 1
124 };
125
126 G_LABEL_INIT(reiserfs, g_label_reiserfs, "Create device nodes for REISERFS volumes");
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