Add gpt pseudo-metadata
[thirdparty/mdadm.git] / super-gpt.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 * 'gpt' is a pseudo metadata type for devices which have a
28 * GPT partition table.
29 *
30 * Obviously arrays cannot be created or assembled for this type.
31 * It is used to allow a new bare device to have an partition table
32 * added so the member partitions can then be included in other
33 * arrays as relevant.
34 *
35 * The meaning operations are:
36 * examine_super, but not brief_examine_super or export_examine
37 * load_super
38 * store_super
39 */
40
41 #include "mdadm.h"
42 #include "part.h"
43
44 static void free_gpt(struct supertype *st)
45 {
46 free(st->sb);
47 st->sb = NULL;
48 }
49
50 #ifndef MDASSEMBLE
51 static void examine_gpt(struct supertype *st, char *homehost)
52 {
53 struct GPT *gpt = st->sb + 512;
54 struct GPT_part_entry *gpe = st->sb + 1024;
55 unsigned int i;
56
57 printf(" GPT Magic : %llx\n", (unsigned long long)__le64_to_cpu(gpt->magic));
58 printf(" GPT Revision : %ld\n", (long)__le32_to_cpu(gpt->revision));
59 for (i = 0; i < __le32_to_cpu(gpt->part_cnt); i++) {
60 printf(" Partition[%02d] : %12llu sectors at %12llu\n",
61 i,
62 (unsigned long long)__le64_to_cpu(gpe[i].starting_lba),
63 (unsigned long long)__le64_to_cpu(gpe[i].ending_lba)-
64 (unsigned long long)__le64_to_cpu(gpe[i].starting_lba)
65 +1
66 );
67 }
68 }
69 #endif /* MDASSEMBLE */
70
71 static int load_gpt(struct supertype *st, int fd, char *devname)
72 {
73 struct MBR *super;
74 struct GPT *gpt_head;
75 int to_read;
76
77 free_gpt(st);
78
79 if (st->subarray[0])
80 return 1;
81
82 if (posix_memalign((void**)&super, 512, 32*512) != 0) {
83 fprintf(stderr, Name ": %s could not allocate superblock\n",
84 __func__);
85 return 1;
86 }
87
88 ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
89
90 lseek(fd, 0, 0);
91 if (read(fd, super, sizeof(*super)) != sizeof(*super)) {
92 no_read:
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 super->parts[0].part_type != MBR_GPT_PARTITION_TYPE) {
102 not_found:
103 if (devname)
104 fprintf(stderr, Name ": No partition table found on %s\n",
105 devname);
106 free(super);
107 return 1;
108 }
109 /* Seem to have GPT, load the header */
110 gpt_head = (struct GPT*)(super+1);
111 if (read(fd, gpt_head, sizeof(*gpt_head)) != sizeof(*gpt_head))
112 goto no_read;
113 if (gpt_head->magic != GPT_SIGNATURE_MAGIC)
114 goto not_found;
115 if (__le32_to_cpu(gpt_head->part_cnt) >= 128)
116 goto not_found;
117
118 to_read = __le32_to_cpu(gpt_head->part_cnt) * sizeof(struct GPT_part_entry);
119 to_read = ((to_read+511)/512) * 512;
120 if (read(fd, gpt_head+1, to_read) != to_read)
121 goto no_read;
122
123 st->sb = super;
124
125 if (st->ss == NULL) {
126 st->ss = &gpt;
127 st->minor_version = 0;
128 st->max_devs = 1;
129 st->info = NULL;
130 }
131 return 0;
132 }
133
134 static int store_gpt(struct supertype *st, int fd)
135 {
136 /* FIXME should I save the boot loader */
137 /* need to write two copies! */
138 /* FIXME allow for blocks != 512 bytes
139 *etc
140 */
141 struct MBR *super = st->sb;
142 struct GPT *gpt;
143 int to_write;
144
145 gpt = (struct GPT*)(super+1);
146
147 to_write = __le32_to_cpu(gpt->part_cnt) * sizeof(struct GPT_part_entry);
148 to_write = ((to_write+511)/512) * 512;
149
150 lseek(fd, 0, 0);
151 if (write(fd, st->sb, to_write) != to_write)
152 return 4;
153
154 fsync(fd);
155 ioctl(fd, BLKRRPART, 0);
156 return 0;
157 }
158
159 static void getinfo_gpt(struct supertype *st, struct mdinfo *info)
160 {
161 struct GPT *gpt = st->sb + 512;
162 struct GPT_part_entry *gpe = st->sb + 1024;
163 unsigned int i;
164
165 memset(&info->array, 0, sizeof(info->array));
166 memset(&info->disk, 0, sizeof(info->disk));
167 strcpy(info->text_version, "gpt");
168 strcpy(info->name, "gpt");
169 info->component_size = 0;
170
171 for (i = 0; i < __le32_to_cpu(gpt->part_cnt); i++) {
172 unsigned long long last =
173 (unsigned long long)__le64_to_cpu(gpe[i].ending_lba);
174 if (last > info->component_size)
175 info->component_size = last;
176 }
177 }
178
179 static struct supertype *match_metadata_desc(char *arg)
180 {
181 struct supertype *st = malloc(sizeof(*st));
182
183 if (!st)
184 return st;
185 if (strcmp(arg, "gpt") != 0)
186 return NULL;
187
188 st->ss = &gpt;
189 st->info = NULL;
190 st->minor_version = 0;
191 st->max_devs = 1;
192 st->sb = NULL;
193 return st;
194 }
195
196 #ifndef MDASSEMBLE
197 static int validate_geometry(struct supertype *st, int level,
198 int layout, int raiddisks,
199 int chunk, unsigned long long size,
200 char *subdev, unsigned long long *freesize,
201 int verbose)
202 {
203 fprintf(stderr, Name ": gpt metadata cannot be used this way\n");
204 return 0;
205 }
206 #endif
207
208 struct superswitch gpt = {
209 #ifndef MDASSEMBLE
210 .examine_super = examine_gpt,
211 #endif
212 .validate_geometry = validate_geometry,
213 .match_metadata_desc = match_metadata_desc,
214 .load_super = load_gpt,
215 .store_super = store_gpt,
216 .getinfo_super = getinfo_gpt,
217 .free_super = free_gpt,
218 .name = "gpt",
219 };