fs/udf/partition.c

   1 /*
   2  * partition.c
   3  *
   4  * PURPOSE
   5  *      Partition handling routines for the OSTA-UDF(tm) filesystem.
   6  *
   7  * COPYRIGHT
   8  *      This file is distributed under the terms of the GNU General Public
   9  *      License (GPL). Copies of the GPL can be obtained from:
  10  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
  11  *      Each contributing author retains all rights to their own work.
  12  *
  13  *  (C) 1998-2001 Ben Fennema
  14  *
  15  * HISTORY
  16  *
  17  * 12/06/98 blf  Created file.
  18  *
  19  */
  20
  21 #include "udfdecl.h"
  22 #include "udf_sb.h"
  23 #include "udf_i.h"
  24
  25 #include <linux/fs.h>
  26 #include <linux/string.h>
  27 #include <linux/slab.h>
  28 #include <linux/buffer_head.h>
  29
  30 inline uint32_t udf_get_pblock(struct super_block *sb, uint32_t block,
  31                                uint16_t partition, uint32_t offset)
  32 {
  33         struct udf_sb_info *sbi = UDF_SB(sb);
  34         struct udf_part_map *map;
  35         if (partition >= sbi->s_partitions) {
  36                 udf_debug("block=%d, partition=%d, offset=%d: "
  37                           "invalid partition\n", block, partition, offset);
  38                 return 0xFFFFFFFF;
  39         }
  40         map = &sbi->s_partmaps[partition];
  41         if (map->s_partition_func)
  42                 return map->s_partition_func(sb, block, partition, offset);
  43         else
  44                 return map->s_partition_root + block + offset;
  45 }
  46
  47 uint32_t udf_get_pblock_virt15(struct super_block *sb, uint32_t block,
  48                                uint16_t partition, uint32_t offset)
  49 {
  50         struct buffer_head *bh = NULL;
  51         uint32_t newblock;
  52         uint32_t index;
  53         uint32_t loc;
  54         struct udf_sb_info *sbi = UDF_SB(sb);
  55         struct udf_part_map *map;
  56         struct udf_virtual_data *vdata;
  57         struct udf_inode_info *iinfo;
  58
  59         map = &sbi->s_partmaps[partition];
  60         vdata = &map->s_type_specific.s_virtual;
  61         index = (sb->s_blocksize - vdata->s_start_offset) / sizeof(uint32_t);
  62
  63         if (block > vdata->s_num_entries) {
  64                 udf_debug("Trying to access block beyond end of VAT "
  65                           "(%d max %d)\n", block, vdata->s_num_entries);
  66                 return 0xFFFFFFFF;
  67         }
  68
  69         if (block >= index) {
  70                 block -= index;
  71                 newblock = 1 + (block / (sb->s_blocksize / sizeof(uint32_t)));
  72                 index = block % (sb->s_blocksize / sizeof(uint32_t));
  73         } else {
  74                 newblock = 0;
  75                 index = vdata->s_start_offset / sizeof(uint32_t) + block;
  76         }
  77
  78         loc = udf_block_map(sbi->s_vat_inode, newblock);
  79
  80         bh = sb_bread(sb, loc);
  81         if (!bh) {
  82                 udf_debug("get_pblock(UDF_VIRTUAL_MAP:%p,%d,%d) VAT: %d[%d]\n",
  83                           sb, block, partition, loc, index);
  84                 return 0xFFFFFFFF;
  85         }
  86
  87         loc = le32_to_cpu(((__le32 *)bh->b_data)[index]);
  88
  89         brelse(bh);
  90
  91         iinfo = UDF_I(sbi->s_vat_inode);
  92         if (iinfo->i_location.partitionReferenceNum == partition) {
  93                 udf_debug("recursive call to udf_get_pblock!\n");
  94                 return 0xFFFFFFFF;
  95         }
  96
  97         return udf_get_pblock(sb, loc,
  98                               iinfo->i_location.partitionReferenceNum,
  99                               offset);
 100 }
 101
 102 inline uint32_t udf_get_pblock_virt20(struct super_block *sb, uint32_t block,
 103                                       uint16_t partition, uint32_t offset)
 104 {
 105         return udf_get_pblock_virt15(sb, block, partition, offset);
 106 }
 107
 108 uint32_t udf_get_pblock_spar15(struct super_block *sb, uint32_t block,
 109                                uint16_t partition, uint32_t offset)
 110 {
 111         int i;
 112         struct sparingTable *st = NULL;
 113         struct udf_sb_info *sbi = UDF_SB(sb);
 114         struct udf_part_map *map;
 115         uint32_t packet;
 116         struct udf_sparing_data *sdata;
 117
 118         map = &sbi->s_partmaps[partition];
 119         sdata = &map->s_type_specific.s_sparing;
 120         packet = (block + offset) & ~(sdata->s_packet_len - 1);
 121
 122         for (i = 0; i < 4; i++) {
 123                 if (sdata->s_spar_map[i] != NULL) {
 124                         st = (struct sparingTable *)
 125                                         sdata->s_spar_map[i]->b_data;
 126                         break;
 127                 }
 128         }
 129
 130         if (st) {
 131                 for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {
 132                         struct sparingEntry *entry = &st->mapEntry[i];
 133                         u32 origLoc = le32_to_cpu(entry->origLocation);
 134                         if (origLoc >= 0xFFFFFFF0)
 135                                 break;
 136                         else if (origLoc == packet)
 137                                 return le32_to_cpu(entry->mappedLocation) +
 138                                         ((block + offset) &
 139                                                 (sdata->s_packet_len - 1));
 140                         else if (origLoc > packet)
 141                                 break;
 142                 }
 143         }
 144
 145         return map->s_partition_root + block + offset;
 146 }
 147
 148 int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
 149 {
 150         struct udf_sparing_data *sdata;
 151         struct sparingTable *st = NULL;
 152         struct sparingEntry mapEntry;
 153         uint32_t packet;
 154         int i, j, k, l;
 155         struct udf_sb_info *sbi = UDF_SB(sb);
 156         u16 reallocationTableLen;
 157         struct buffer_head *bh;
 158
 159         for (i = 0; i < sbi->s_partitions; i++) {
 160                 struct udf_part_map *map = &sbi->s_partmaps[i];
 161                 if (old_block > map->s_partition_root &&
 162                     old_block < map->s_partition_root + map->s_partition_len) {
 163                         sdata = &map->s_type_specific.s_sparing;
 164                         packet = (old_block - map->s_partition_root) &
 165                                                 ~(sdata->s_packet_len - 1);
 166
 167                         for (j = 0; j < 4; j++)
 168                                 if (sdata->s_spar_map[j] != NULL) {
 169                                         st = (struct sparingTable *)
 170                                                 sdata->s_spar_map[j]->b_data;
 171                                         break;
 172                                 }
 173
 174                         if (!st)
 175                                 return 1;
 176
 177                         reallocationTableLen =
 178                                         le16_to_cpu(st->reallocationTableLen);
 179                         for (k = 0; k < reallocationTableLen; k++) {
 180                                 struct sparingEntry *entry = &st->mapEntry[k];
 181                                 u32 origLoc = le32_to_cpu(entry->origLocation);
 182
 183                                 if (origLoc == 0xFFFFFFFF) {
 184                                         for (; j < 4; j++) {
 185                                                 int len;
 186                                                 bh = sdata->s_spar_map[j];
 187                                                 if (!bh)
 188                                                         continue;
 189
 190                                                 st = (struct sparingTable *)
 191                                                                 bh->b_data;
 192                                                 entry->origLocation =
 193                                                         cpu_to_le32(packet);
 194                                                 len =
 195                                                   sizeof(struct sparingTable) +
 196                                                   reallocationTableLen *
 197                                                   sizeof(struct sparingEntry);
 198                                                 udf_update_tag((char *)st, len);
 199                                                 mark_buffer_dirty(bh);
 200                                         }
 201                                         *new_block = le32_to_cpu(
 202                                                         entry->mappedLocation) +
 203                                                      ((old_block -
 204                                                         map->s_partition_root) &
 205                                                      (sdata->s_packet_len - 1));
 206                                         return 0;
 207                                 } else if (origLoc == packet) {
 208                                         *new_block = le32_to_cpu(
 209                                                         entry->mappedLocation) +
 210                                                      ((old_block -
 211                                                         map->s_partition_root) &
 212                                                      (sdata->s_packet_len - 1));
 213                                         return 0;
 214                                 } else if (origLoc > packet)
 215                                         break;
 216                         }
 217
 218                         for (l = k; l < reallocationTableLen; l++) {
 219                                 struct sparingEntry *entry = &st->mapEntry[l];
 220                                 u32 origLoc = le32_to_cpu(entry->origLocation);
 221
 222                                 if (origLoc != 0xFFFFFFFF)
 223                                         continue;
 224
 225                                 for (; j < 4; j++) {
 226                                         bh = sdata->s_spar_map[j];
 227                                         if (!bh)
 228                                                 continue;
 229
 230                                         st = (struct sparingTable *)bh->b_data;
 231                                         mapEntry = st->mapEntry[l];
 232                                         mapEntry.origLocation =
 233                                                         cpu_to_le32(packet);
 234                                         memmove(&st->mapEntry[k + 1],
 235                                                 &st->mapEntry[k],
 236                                                 (l - k) *
 237                                                 sizeof(struct sparingEntry));
 238                                         st->mapEntry[k] = mapEntry;
 239                                         udf_update_tag((char *)st,
 240                                                 sizeof(struct sparingTable) +
 241                                                 reallocationTableLen *
 242                                                 sizeof(struct sparingEntry));
 243                                         mark_buffer_dirty(bh);
 244                                 }
 245                                 *new_block =
 246                                         le32_to_cpu(
 247                                               st->mapEntry[k].mappedLocation) +
 248                                         ((old_block - map->s_partition_root) &
 249                                          (sdata->s_packet_len - 1));
 250                                 return 0;
 251                         }
 252
 253                         return 1;
 254                 } /* if old_block */
 255         }
 256
 257         if (i == sbi->s_partitions) {
 258                 /* outside of partitions */
 259                 /* for now, fail =) */
 260                 return 1;
 261         }
 262
 263         return 0;
 264 }