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DDF: compare_super_ddf: merge local info of other superblock
[thirdparty/mdadm.git] / super-mbr.c
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
45 static void free_mbr(struct supertype *st)
46 {
47 free(st->sb);
48 st->sb = NULL;
49 }
50
51 #ifndef MDASSEMBLE
52
53 static 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
71 static 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
83 if (posix_memalign((void**)&super, 512, 512) != 0) {
84 pr_err("%s could not allocate superblock\n",
85 __func__);
86 return 1;
87 }
88
89 lseek(fd, 0, 0);
90 if (read(fd, super, sizeof(*super)) != sizeof(*super)) {
91 if (devname)
92 pr_err("Cannot read partition table on %s\n",
93 devname);
94 free(super);
95 return 1;
96 }
97
98 if (super->magic != MBR_SIGNATURE_MAGIC) {
99 if (devname)
100 pr_err("No partition table found on %s\n",
101 devname);
102 free(super);
103 return 1;
104 }
105
106 st->sb = super;
107
108 if (st->ss == NULL) {
109 st->ss = &mbr;
110 st->minor_version = 0;
111 st->max_devs = 1;
112 st->info = NULL;
113 }
114 return 0;
115 }
116
117 static int store_mbr(struct supertype *st, int fd)
118 {
119 struct MBR *old, *super;
120
121 if (posix_memalign((void**)&old, 512, 512) != 0) {
122 pr_err("%s could not allocate superblock\n",
123 __func__);
124 return 1;
125 }
126
127 lseek(fd, 0, 0);
128 if (read(fd, old, sizeof(*old)) != sizeof(*old)) {
129 free(old);
130 return 1;
131 }
132
133 super = st->sb;
134 memcpy(super->pad, old->pad, sizeof(super->pad));
135 free(old);
136 lseek(fd, 0, 0);
137 if (write(fd, super, sizeof(*super)) != sizeof(*super))
138 return 4;
139 fsync(fd);
140 ioctl(fd, BLKRRPART, 0);
141 return 0;
142 }
143
144 static void getinfo_mbr(struct supertype *st, struct mdinfo *info, char *map)
145 {
146 struct MBR *sb = st->sb;
147 int i;
148
149 memset(&info->array, 0, sizeof(info->array));
150 memset(&info->disk, 0, sizeof(info->disk));
151 strcpy(info->text_version, "mbr");
152 strcpy(info->name, "mbr");
153 info->component_size = 0;
154
155 for (i = 0; i < MBR_PARTITIONS ; i++)
156 if (sb->parts[i].blocks_num) {
157 unsigned long last =
158 (unsigned long)__le32_to_cpu(sb->parts[i].blocks_num)
159 + (unsigned long)__le32_to_cpu(sb->parts[i].first_sect_lba);
160 if (last > info->component_size)
161 info->component_size = last;
162 }
163
164 }
165
166 static struct supertype *match_metadata_desc(char *arg)
167 {
168 struct supertype *st;
169
170 if (strcmp(arg, "mbr") != 0)
171 return NULL;
172
173 st = xmalloc(sizeof(*st));
174 st->ss = &mbr;
175 st->info = NULL;
176 st->minor_version = 0;
177 st->max_devs = 1;
178 st->sb = NULL;
179 return st;
180 }
181
182 #ifndef MDASSEMBLE
183 static int validate_geometry(struct supertype *st, int level,
184 int layout, int raiddisks,
185 int *chunk, unsigned long long size,
186 unsigned long long data_offset,
187 char *subdev, unsigned long long *freesize,
188 int verbose)
189 {
190 pr_err("mbr metadata cannot be used this way\n");
191 return 0;
192 }
193 #endif
194
195 struct superswitch mbr = {
196 #ifndef MDASSEMBLE
197 .examine_super = examine_mbr,
198 .validate_geometry = validate_geometry,
199 #endif
200 .match_metadata_desc = match_metadata_desc,
201 .load_super = load_super_mbr,
202 .store_super = store_mbr,
203 .getinfo_super = getinfo_mbr,
204 .free_super = free_mbr,
205 .name = "mbr",
206 };