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/udf_fs.h>
  28 #include <linux/slab.h>
  29 #include <linux/buffer_head.h>
  30
  31 inline uint32_t udf_get_pblock(struct super_block *sb, uint32_t block,
  32                                uint16_t partition, uint32_t offset)
  33 {
  34         struct udf_sb_info *sbi = UDF_SB(sb);
  35         struct udf_part_map *map;
  36         if (partition >= sbi->s_partitions) {
  37                 udf_debug("block=%d, partition=%d, offset=%d: "
  38                           "invalid partition\n", block, partition, offset);
  39                 return 0xFFFFFFFF;
  40         }
  41         map = &sbi->s_partmaps[partition];
  42         if (map->s_partition_func)
  43                 return map->s_partition_func(sb, block, partition, offset);
  44         else
  45                 return map->s_partition_root + block + offset;
  46 }
  47
  48 uint32_t udf_get_pblock_virt15(struct super_block *sb, uint32_t block,
  49                                uint16_t partition, uint32_t offset)
  50 {
  51         struct buffer_head *bh = NULL;
  52         uint32_t newblock;
  53         uint32_t index;
  54         uint32_t loc;
  55         struct udf_sb_info *sbi = UDF_SB(sb);
  56         struct udf_part_map *map;
  57         struct udf_virtual_data *vdata;
  58         struct udf_inode_info *iinfo;
  59
  60         map = &sbi->s_partmaps[partition];
  61         vdata = &map->s_type_specific.s_virtual;
  62         index = (sb->s_blocksize - vdata->s_start_offset) / sizeof(uint32_t);
  63
  64         if (block > vdata->s_num_entries) {
  65                 udf_debug("Trying to access block beyond end of VAT "
  66                           "(%d max %d)\n", block, vdata->s_num_entries);
  67                 return 0xFFFFFFFF;
  68         }
  69
  70         if (block >= index) {
  71                 block -= index;
  72                 newblock = 1 + (block / (sb->s_blocksize / sizeof(uint32_t)));
  73                 index = block % (sb->s_blocksize / sizeof(uint32_t));
  74         } else {
  75                 newblock = 0;
  76                 index = vdata->s_start_offset / sizeof(uint32_t) + block;
  77         }
  78
  79         loc = udf_block_map(sbi->s_vat_inode, newblock);
  80
  81         bh = sb_bread(sb, loc);
  82         if (!bh) {
  83                 udf_debug("get_pblock(UDF_VIRTUAL_MAP:%p,%d,%d) VAT: %d[%d]\n",
  84                           sb, block, partition, loc, index);
  85                 return 0xFFFFFFFF;
  86         }
  87
  88         loc = le32_to_cpu(((__le32 *)bh->b_data)[index]);
  89
  90         brelse(bh);
  91
  92         iinfo = UDF_I(sbi->s_vat_inode);
  93         if (iinfo->i_location.partitionReferenceNum == partition) {
  94                 udf_debug("recursive call to udf_get_pblock!\n");
  95                 return 0xFFFFFFFF;
  96         }
  97
  98         return udf_get_pblock(sb, loc,
  99                               iinfo->i_location.partitionReferenceNum,
 100                               offset);
 101 }
 102
 103 inline uint32_t udf_get_pblock_virt20(struct super_block *sb, uint32_t block,
 104                                       uint16_t partition, uint32_t offset)
 105 {
 106         return udf_get_pblock_virt15(sb, block, partition, offset);
 107 }
 108
 109 uint32_t udf_get_pblock_spar15(struct super_block *sb, uint32_t block,
 110                                uint16_t partition, uint32_t offset)
 111 {
 112         int i;
 113         struct sparingTable *st = NULL;
 114         struct udf_sb_info *sbi = UDF_SB(sb);
 115         struct udf_part_map *map;
 116         uint32_t packet;
 117         struct udf_sparing_data *sdata;
 118
 119         map = &sbi->s_partmaps[partition];
 120         sdata = &map->s_type_specific.s_sparing;
 121         packet = (block + offset) & ~(sdata->s_packet_len - 1);
 122
 123         for (i = 0; i < 4; i++) {
 124                 if (sdata->s_spar_map[i] != NULL) {
 125                         st = (struct sparingTable *)
 126                                         sdata->s_spar_map[i]->b_data;
 127                         break;
 128                 }
 129         }
 130
 131         if (st) {
 132                 for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {
 133                         struct sparingEntry *entry = &st->mapEntry[i];
 134                         u32 origLoc = le32_to_cpu(entry->origLocation);
 135                         if (origLoc >= 0xFFFFFFF0)
 136                                 break;
 137                         else if (origLoc == packet)
 138                                 return le32_to_cpu(entry->mappedLocation) +
 139                                         ((block + offset) &
 140                                                 (sdata->s_packet_len - 1));
 141                         else if (origLoc > packet)
 142                                 break;
 143                 }
 144         }
 145
 146         return map->s_partition_root + block + offset;
 147 }
 148
 149 int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
 150 {
 151         struct udf_sparing_data *sdata;
 152         struct sparingTable *st = NULL;
 153         struct sparingEntry mapEntry;
 154         uint32_t packet;
 155         int i, j, k, l;
 156         struct udf_sb_info *sbi = UDF_SB(sb);
 157         u16 reallocationTableLen;
 158         struct buffer_head *bh;
 159
 160         for (i = 0; i < sbi->s_partitions; i++) {
 161                 struct udf_part_map *map = &sbi->s_partmaps[i];
 162                 if (old_block > map->s_partition_root &&
 163                     old_block < map->s_partition_root + map->s_partition_len) {
 164                         sdata = &map->s_type_specific.s_sparing;
 165                         packet = (old_block - map->s_partition_root) &
 166                                                 ~(sdata->s_packet_len - 1);
 167
 168                         for (j = 0; j < 4; j++)
 169                                 if (sdata->s_spar_map[j] != NULL) {
 170                                         st = (struct sparingTable *)
 171                                                 sdata->s_spar_map[j]->b_data;
 172                                         break;
 173                                 }
 174
 175                         if (!st)
 176                                 return 1;
 177
 178                         reallocationTableLen =
 179                                         le16_to_cpu(st->reallocationTableLen);
 180                         for (k = 0; k < reallocationTableLen; k++) {
 181                                 struct sparingEntry *entry = &st->mapEntry[k];
 182                                 u32 origLoc = le32_to_cpu(entry->origLocation);
 183
 184                                 if (origLoc == 0xFFFFFFFF) {
 185                                         for (; j < 4; j++) {
 186                                                 int len;
 187                                                 bh = sdata->s_spar_map[j];
 188                                                 if (!bh)
 189                                                         continue;
 190
 191                                                 st = (struct sparingTable *)
 192                                                                 bh->b_data;
 193                                                 entry->origLocation =
 194                                                         cpu_to_le32(packet);
 195                                                 len =
 196                                                   sizeof(struct sparingTable) +
 197                                                   reallocationTableLen *
 198                                                   sizeof(struct sparingEntry);
 199                                                 udf_update_tag((char *)st, len);
 200                                                 mark_buffer_dirty(bh);
 201                                         }
 202                                         *new_block = le32_to_cpu(
 203                                                         entry->mappedLocation) +
 204                                                      ((old_block -
 205                                                         map->s_partition_root) &
 206                                                      (sdata->s_packet_len - 1));
 207                                         return 0;
 208                                 } else if (origLoc == packet) {
 209                                         *new_block = le32_to_cpu(
 210                                                         entry->mappedLocation) +
 211                                                      ((old_block -
 212                                                         map->s_partition_root) &
 213                                                      (sdata->s_packet_len - 1));
 214                                         return 0;
 215                                 } else if (origLoc > packet)
 216                                         break;
 217                         }
 218
 219                         for (l = k; l < reallocationTableLen; l++) {
 220                                 struct sparingEntry *entry = &st->mapEntry[l];
 221                                 u32 origLoc = le32_to_cpu(entry->origLocation);
 222
 223                                 if (origLoc != 0xFFFFFFFF)
 224                                         continue;
 225
 226                                 for (; j < 4; j++) {
 227                                         bh = sdata->s_spar_map[j];
 228                                         if (!bh)
 229                                                 continue;
 230
 231                                         st = (struct sparingTable *)bh->b_data;
 232                                         mapEntry = st->mapEntry[l];
 233                                         mapEntry.origLocation =
 234                                                         cpu_to_le32(packet);
 235                                         memmove(&st->mapEntry[k + 1],
 236                                                 &st->mapEntry[k],
 237                                                 (l - k) *
 238                                                 sizeof(struct sparingEntry));
 239                                         st->mapEntry[k] = mapEntry;
 240                                         udf_update_tag((char *)st,
 241                                                 sizeof(struct sparingTable) +
 242                                                 reallocationTableLen *
 243                                                 sizeof(struct sparingEntry));
 244                                         mark_buffer_dirty(bh);
 245                                 }
 246                                 *new_block =
 247                                         le32_to_cpu(
 248                                               st->mapEntry[k].mappedLocation) +
 249                                         ((old_block - map->s_partition_root) &
 250                                          (sdata->s_packet_len - 1));
 251                                 return 0;
 252                         }
 253
 254                         return 1;
 255                 } /* if old_block */
 256         }
 257
 258         if (i == sbi->s_partitions) {
 259                 /* outside of partitions */
 260                 /* for now, fail =) */
 261                 return 1;
 262         }
 263
 264         return 0;
 265 }