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Assemble(): don't dup_super() before we need it.
[thirdparty/mdadm.git] / super-mbr.c
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1/*
2 * mdadm - manage Linux "md" devices aka RAID arrays.
3 *
4 * Copyright (C) 2010 Neil Brown <neilb@suse.de>
5 *
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 * Author: Neil Brown
22 * Email: <neil@brown.name>
23 *
24 */
25
26/*
27 * 'mbr' is a pseudo metadata type for devices which have a
28 * partition table in the Master Boot Record (mbr) also known
29 * as a dos partition table.
30 *
31 * Obviously arrays cannot be created or assembled for this type.
32 * It is used to allow a new bare device to have an partition table
33 * added so the member partitions can then be included in other
34 * arrays as relevant.
35 *
36 * The meaning operations are:
37 * examine_super, but not brief_examine_super or export_examine
38 * load_super
39 * store_super
40 */
41
42#include "mdadm.h"
43#include "part.h"
44
45static void free_mbr(struct supertype *st)
46{
47 free(st->sb);
48 st->sb = NULL;
49}
50
51#ifndef MDASSEMBLE
52
53static void examine_mbr(struct supertype *st, char *homehost)
54{
55 struct MBR *sb = st->sb;
56 int i;
57
58 printf(" MBR Magic : %04x\n", sb->magic);
59 for (i = 0; i < MBR_PARTITIONS; i++)
60 if (sb->parts[i].blocks_num)
61 printf("Partition[%d] : %12lu sectors at %12lu (type %02x)\n",
62 i,
63 (unsigned long)__le32_to_cpu(sb->parts[i].blocks_num),
64 (unsigned long)__le32_to_cpu(sb->parts[i].first_sect_lba),
65 sb->parts[i].part_type);
66
67}
68
69#endif /*MDASSEMBLE */
70
71static int load_super_mbr(struct supertype *st, int fd, char *devname)
72{
73 /* try to read an mbr
74 * Return
75 * 0 on success
76 * 1 cannot get record
77 * 2 record is meaningless
78 */
79 struct MBR *super;
80
81 free_mbr(st);
82
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83 if (posix_memalign((void**)&super, 512, 512) != 0) {
84 fprintf(stderr, Name ": %s could not allocate superblock\n",
85 __func__);
86 return 1;
87 }
88
89 ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
90
91 lseek(fd, 0, 0);
92 if (read(fd, super, sizeof(*super)) != sizeof(*super)) {
93 if (devname)
94 fprintf(stderr, Name ": Cannot read partition table on %s\n",
95 devname);
96 free(super);
97 return 1;
98 }
99
100 if (super->magic != MBR_SIGNATURE_MAGIC) {
101 if (devname)
102 fprintf(stderr, Name ": No partition table found on %s\n",
103 devname);
104 free(super);
105 return 1;
106 }
107
108 st->sb = super;
109
110 if (st->ss == NULL) {
111 st->ss = &mbr;
112 st->minor_version = 0;
113 st->max_devs = 1;
114 st->info = NULL;
115 }
116 return 0;
117}
118
119static int store_mbr(struct supertype *st, int fd)
120{
121 struct MBR *old, *super;
122
123 if (posix_memalign((void**)&old, 512, 512) != 0) {
124 fprintf(stderr, Name ": %s could not allocate superblock\n",
125 __func__);
126 return 1;
127 }
128
129 ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
130
131 lseek(fd, 0, 0);
132 if (read(fd, old, sizeof(*old)) != sizeof(*old)) {
133 free(old);
134 return 1;
135 }
136
137 super = st->sb;
138 memcpy(super->pad, old->pad, sizeof(super->pad));
139 free(old);
140 lseek(fd, 0, 0);
141 if (write(fd, super, sizeof(*super)) != sizeof(*super))
142 return 4;
143 fsync(fd);
144 ioctl(fd, BLKRRPART, 0);
145 return 0;
146}
147
a5d85af7 148static void getinfo_mbr(struct supertype *st, struct mdinfo *info, char *map)
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149{
150 struct MBR *sb = st->sb;
151 int i;
152
153 memset(&info->array, 0, sizeof(info->array));
154 memset(&info->disk, 0, sizeof(info->disk));
155 strcpy(info->text_version, "mbr");
156 strcpy(info->name, "mbr");
157 info->component_size = 0;
158
159 for (i = 0; i < MBR_PARTITIONS ; i++)
160 if (sb->parts[i].blocks_num) {
161 unsigned long last =
162 (unsigned long)__le32_to_cpu(sb->parts[i].blocks_num)
163 + (unsigned long)__le32_to_cpu(sb->parts[i].first_sect_lba);
164 if (last > info->component_size)
165 info->component_size = last;
166 }
167
168}
169
170static struct supertype *match_metadata_desc(char *arg)
171{
172 struct supertype *st = malloc(sizeof(*st));
173
174 if (!st)
175 return st;
176 if (strcmp(arg, "mbr") != 0)
177 return NULL;
178
179 st->ss = &mbr;
180 st->info = NULL;
181 st->minor_version = 0;
182 st->max_devs = 1;
183 st->sb = NULL;
184 return st;
185}
186
187#ifndef MDASSEMBLE
188static int validate_geometry(struct supertype *st, int level,
189 int layout, int raiddisks,
c21e737b 190 int *chunk, unsigned long long size,
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191 char *subdev, unsigned long long *freesize,
192 int verbose)
193{
194 fprintf(stderr, Name ": mbr metadata cannot be used this way\n");
195 return 0;
196}
197#endif
198
199struct superswitch mbr = {
200#ifndef MDASSEMBLE
201 .examine_super = examine_mbr,
0f22b998 202 .validate_geometry = validate_geometry,
71204a50 203#endif
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204 .match_metadata_desc = match_metadata_desc,
205 .load_super = load_super_mbr,
206 .store_super = store_mbr,
207 .getinfo_super = getinfo_mbr,
208 .free_super = free_mbr,
209 .name = "mbr",
210};