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 (posix_memalign((void**)&super, 512, 32*512) != 0) {
  80                 fprintf(stderr, Name ": %s could not allocate superblock\n",
  81                         __func__);
  82                 return 1;
  83         }
  84
  85         ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
  86
  87         lseek(fd, 0, 0);
  88         if (read(fd, super, sizeof(*super)) != sizeof(*super)) {
  89         no_read:
  90                 if (devname)
  91                         fprintf(stderr, Name ": Cannot read partition table on %s\n",
  92                                 devname);
  93                 free(super);
  94                 return 1;
  95         }
  96
  97         if (super->magic != MBR_SIGNATURE_MAGIC ||
  98             super->parts[0].part_type != MBR_GPT_PARTITION_TYPE) {
  99         not_found:
 100                 if (devname)
 101                         fprintf(stderr, Name ": No partition table found on %s\n",
 102                                 devname);
 103                 free(super);
 104                 return 1;
 105         }
 106         /* Seem to have GPT, load the header */
 107         gpt_head = (struct GPT*)(super+1);
 108         if (read(fd, gpt_head, sizeof(*gpt_head)) != sizeof(*gpt_head))
 109                 goto no_read;
 110         if (gpt_head->magic != GPT_SIGNATURE_MAGIC)
 111                 goto not_found;
 112         if (__le32_to_cpu(gpt_head->part_cnt) >= 128)
 113                 goto not_found;
 114
 115         to_read = __le32_to_cpu(gpt_head->part_cnt) * sizeof(struct GPT_part_entry);
 116         to_read =  ((to_read+511)/512) * 512;
 117         if (read(fd, gpt_head+1, to_read) != to_read)
 118                 goto no_read;
 119
 120         st->sb = super;
 121
 122         if (st->ss == NULL) {
 123                 st->ss = &gpt;
 124                 st->minor_version = 0;
 125                 st->max_devs = 1;
 126                 st->info = NULL;
 127         }
 128         return 0;
 129 }
 130
 131 static int store_gpt(struct supertype *st, int fd)
 132 {
 133         /* FIXME should I save the boot loader */
 134         /* need to write two copies! */
 135         /* FIXME allow for blocks != 512 bytes
 136          *etc
 137          */
 138         struct MBR *super = st->sb;
 139         struct GPT *gpt;
 140         int to_write;
 141
 142         gpt = (struct GPT*)(super+1);
 143
 144         to_write = __le32_to_cpu(gpt->part_cnt) * sizeof(struct GPT_part_entry);
 145         to_write =  ((to_write+511)/512) * 512;
 146
 147         lseek(fd, 0, 0);
 148         if (write(fd, st->sb, to_write) != to_write)
 149                 return 4;
 150
 151         fsync(fd);
 152         ioctl(fd, BLKRRPART, 0);
 153         return 0;
 154 }
 155
 156 static void getinfo_gpt(struct supertype *st, struct mdinfo *info, char *map)
 157 {
 158         struct GPT *gpt = st->sb + 512;
 159         struct GPT_part_entry *gpe = st->sb + 1024;
 160         unsigned int i;
 161
 162         memset(&info->array, 0, sizeof(info->array));
 163         memset(&info->disk, 0, sizeof(info->disk));
 164         strcpy(info->text_version, "gpt");
 165         strcpy(info->name, "gpt");
 166         info->component_size = 0;
 167
 168         for (i = 0; i < __le32_to_cpu(gpt->part_cnt); i++) {
 169                 unsigned long long last =
 170                         (unsigned long long)__le64_to_cpu(gpe[i].ending_lba);
 171                 if (last > info->component_size)
 172                         info->component_size = last;
 173         }
 174 }
 175
 176 static struct supertype *match_metadata_desc(char *arg)
 177 {
 178         struct supertype *st = malloc(sizeof(*st));
 179
 180         if (!st)
 181                 return st;
 182         if (strcmp(arg, "gpt") != 0)
 183                 return NULL;
 184
 185         st->ss = &gpt;
 186         st->info = NULL;
 187         st->minor_version = 0;
 188         st->max_devs = 1;
 189         st->sb = NULL;
 190         return st;
 191 }
 192
 193 #ifndef MDASSEMBLE
 194 static int validate_geometry(struct supertype *st, int level,
 195                              int layout, int raiddisks,
 196                              int chunk, unsigned long long size,
 197                              char *subdev, unsigned long long *freesize,
 198                              int verbose)
 199 {
 200         fprintf(stderr, Name ": gpt metadata cannot be used this way\n");
 201         return 0;
 202 }
 203 #endif
 204
 205 struct superswitch gpt = {
 206 #ifndef MDASSEMBLE
 207         .examine_super = examine_gpt,
 208         .validate_geometry = validate_geometry,
 209 #endif
 210         .match_metadata_desc = match_metadata_desc,
 211         .load_super = load_gpt,
 212         .store_super = store_gpt,
 213         .getinfo_super = getinfo_gpt,
 214         .free_super = free_gpt,
 215         .name = "gpt",
 216 };