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("%s could not allocate superblock\n",
  81                         __func__);
  82                 return 1;
  83         }
  84
  85         lseek(fd, 0, 0);
  86         if (read(fd, super, sizeof(*super)) != sizeof(*super)) {
  87         no_read:
  88                 if (devname)
  89                         pr_err("Cannot read partition table on %s\n",
  90                                 devname);
  91                 free(super);
  92                 return 1;
  93         }
  94
  95         if (super->magic != MBR_SIGNATURE_MAGIC ||
  96             super->parts[0].part_type != MBR_GPT_PARTITION_TYPE) {
  97         not_found:
  98                 if (devname)
  99                         pr_err("No partition table found on %s\n",
 100                                 devname);
 101                 free(super);
 102                 return 1;
 103         }
 104         /* Seem to have GPT, load the header */
 105         gpt_head = (struct GPT*)(super+1);
 106         if (read(fd, gpt_head, sizeof(*gpt_head)) != sizeof(*gpt_head))
 107                 goto no_read;
 108         if (gpt_head->magic != GPT_SIGNATURE_MAGIC)
 109                 goto not_found;
 110         if (__le32_to_cpu(gpt_head->part_cnt) >= 128)
 111                 goto not_found;
 112
 113         to_read = __le32_to_cpu(gpt_head->part_cnt) * sizeof(struct GPT_part_entry);
 114         to_read =  ((to_read+511)/512) * 512;
 115         if (read(fd, gpt_head+1, to_read) != to_read)
 116                 goto no_read;
 117
 118         st->sb = super;
 119
 120         if (st->ss == NULL) {
 121                 st->ss = &gpt;
 122                 st->minor_version = 0;
 123                 st->max_devs = 1;
 124                 st->info = NULL;
 125         }
 126         return 0;
 127 }
 128
 129 static int store_gpt(struct supertype *st, int fd)
 130 {
 131         /* FIXME should I save the boot loader */
 132         /* need to write two copies! */
 133         /* FIXME allow for blocks != 512 bytes
 134          *etc
 135          */
 136         struct MBR *super = st->sb;
 137         struct GPT *gpt;
 138         int to_write;
 139
 140         gpt = (struct GPT*)(super+1);
 141
 142         to_write = __le32_to_cpu(gpt->part_cnt) * sizeof(struct GPT_part_entry);
 143         to_write =  ((to_write+511)/512) * 512;
 144
 145         lseek(fd, 0, 0);
 146         if (write(fd, st->sb, to_write) != to_write)
 147                 return 4;
 148
 149         fsync(fd);
 150         ioctl(fd, BLKRRPART, 0);
 151         return 0;
 152 }
 153
 154 static void getinfo_gpt(struct supertype *st, struct mdinfo *info, char *map)
 155 {
 156         struct GPT *gpt = st->sb + 512;
 157         struct GPT_part_entry *gpe = st->sb + 1024;
 158         unsigned int i;
 159
 160         memset(&info->array, 0, sizeof(info->array));
 161         memset(&info->disk, 0, sizeof(info->disk));
 162         strcpy(info->text_version, "gpt");
 163         strcpy(info->name, "gpt");
 164         info->component_size = 0;
 165
 166         for (i = 0; i < __le32_to_cpu(gpt->part_cnt); i++) {
 167                 unsigned long long last =
 168                         (unsigned long long)__le64_to_cpu(gpe[i].ending_lba);
 169                 if (last > info->component_size)
 170                         info->component_size = last;
 171         }
 172 }
 173
 174 static struct supertype *match_metadata_desc(char *arg)
 175 {
 176         struct supertype *st = xmalloc(sizeof(*st));
 177
 178         if (!st)
 179                 return st;
 180         if (strcmp(arg, "gpt") != 0) {
 181                 free(st);
 182                 return NULL;
 183         }
 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                              unsigned long long data_offset,
 198                              char *subdev, unsigned long long *freesize,
 199                              int verbose)
 200 {
 201         pr_err("gpt metadata cannot be used this way\n");
 202         return 0;
 203 }
 204 #endif
 205
 206 struct superswitch gpt = {
 207 #ifndef MDASSEMBLE
 208         .examine_super = examine_gpt,
 209         .validate_geometry = validate_geometry,
 210 #endif
 211         .match_metadata_desc = match_metadata_desc,
 212         .load_super = load_gpt,
 213         .store_super = store_gpt,
 214         .getinfo_super = getinfo_gpt,
 215         .free_super = free_gpt,
 216         .name = "gpt",
 217 };