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, 4096, 32*512) != 0) {
  80                 pr_err("could not allocate superblock\n");
  81                 return 1;
  82         }
  83
  84         lseek(fd, 0, 0);
  85         if (read(fd, super, sizeof(*super)) != sizeof(*super)) {
  86         no_read:
  87                 if (devname)
  88                         pr_err("Cannot read partition table on %s\n",
  89                                 devname);
  90                 free(super);
  91                 return 1;
  92         }
  93
  94         if (super->magic != MBR_SIGNATURE_MAGIC ||
  95             super->parts[0].part_type != MBR_GPT_PARTITION_TYPE) {
  96         not_found:
  97                 if (devname)
  98                         pr_err("No partition table found on %s\n",
  99                                 devname);
 100                 free(super);
 101                 return 1;
 102         }
 103         /* Seem to have GPT, load the header */
 104         gpt_head = (struct GPT*)(super+1);
 105         if (read(fd, gpt_head, sizeof(*gpt_head)) != sizeof(*gpt_head))
 106                 goto no_read;
 107         if (gpt_head->magic != GPT_SIGNATURE_MAGIC)
 108                 goto not_found;
 109         if (__le32_to_cpu(gpt_head->part_cnt) >= 128)
 110                 goto not_found;
 111
 112         to_read = __le32_to_cpu(gpt_head->part_cnt) * sizeof(struct GPT_part_entry);
 113         to_read =  ((to_read+511)/512) * 512;
 114         if (read(fd, gpt_head+1, to_read) != to_read)
 115                 goto no_read;
 116
 117         st->sb = super;
 118
 119         if (st->ss == NULL) {
 120                 st->ss = &gpt;
 121                 st->minor_version = 0;
 122                 st->max_devs = 1;
 123                 st->info = NULL;
 124         }
 125         return 0;
 126 }
 127
 128 static int store_gpt(struct supertype *st, int fd)
 129 {
 130         /* FIXME should I save the boot loader */
 131         /* need to write two copies! */
 132         /* FIXME allow for blocks != 512 bytes
 133          *etc
 134          */
 135         struct MBR *super = st->sb;
 136         struct GPT *gpt;
 137         int to_write;
 138
 139         gpt = (struct GPT*)(super+1);
 140
 141         to_write = __le32_to_cpu(gpt->part_cnt) * sizeof(struct GPT_part_entry);
 142         to_write =  ((to_write+511)/512) * 512;
 143
 144         lseek(fd, 0, 0);
 145         if (write(fd, st->sb, to_write) != to_write)
 146                 return 4;
 147
 148         fsync(fd);
 149         ioctl(fd, BLKRRPART, 0);
 150         return 0;
 151 }
 152
 153 static void getinfo_gpt(struct supertype *st, struct mdinfo *info, char *map)
 154 {
 155         struct GPT *gpt = st->sb + 512;
 156         struct GPT_part_entry *gpe = st->sb + 1024;
 157         unsigned int i;
 158
 159         memset(&info->array, 0, sizeof(info->array));
 160         memset(&info->disk, 0, sizeof(info->disk));
 161         strcpy(info->text_version, "gpt");
 162         strcpy(info->name, "gpt");
 163         info->component_size = 0;
 164
 165         for (i = 0; i < __le32_to_cpu(gpt->part_cnt); i++) {
 166                 unsigned long long last =
 167                         (unsigned long long)__le64_to_cpu(gpe[i].ending_lba);
 168                 if (last > info->component_size)
 169                         info->component_size = last;
 170         }
 171 }
 172
 173 static struct supertype *match_metadata_desc(char *arg)
 174 {
 175         struct supertype *st = xmalloc(sizeof(*st));
 176
 177         if (!st)
 178                 return st;
 179         if (strcmp(arg, "gpt") != 0) {
 180                 free(st);
 181                 return NULL;
 182         }
 183
 184         st->ss = &gpt;
 185         st->info = NULL;
 186         st->minor_version = 0;
 187         st->max_devs = 1;
 188         st->sb = NULL;
 189         return st;
 190 }
 191
 192 #ifndef MDASSEMBLE
 193 static int validate_geometry(struct supertype *st, int level,
 194                              int layout, int raiddisks,
 195                              int *chunk, unsigned long long size,
 196                              unsigned long long data_offset,
 197                              char *subdev, unsigned long long *freesize,
 198                              int verbose)
 199 {
 200         pr_err("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 };