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 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 = UDF_I(sbi->s_vat_inode);
  58
  59         map = &sbi->s_partmaps[partition];
  60         vdata = &map->s_type_specific.s_virtual;
  61
  62         if (block > vdata->s_num_entries) {
  63                 udf_debug("Trying to access block beyond end of VAT "
  64                           "(%d max %d)\n", block, vdata->s_num_entries);
  65                 return 0xFFFFFFFF;
  66         }
  67
  68         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
  69                 loc = le32_to_cpu(((__le32 *)(iinfo->i_ext.i_data +
  70                         vdata->s_start_offset))[block]);
  71                 goto translate;
  72         }
  73         index = (sb->s_blocksize - vdata->s_start_offset) / sizeof(uint32_t);
  74         if (block >= index) {
  75                 block -= index;
  76                 newblock = 1 + (block / (sb->s_blocksize / sizeof(uint32_t)));
  77                 index = block % (sb->s_blocksize / sizeof(uint32_t));
  78         } else {
  79                 newblock = 0;
  80                 index = vdata->s_start_offset / sizeof(uint32_t) + block;
  81         }
  82
  83         loc = udf_block_map(sbi->s_vat_inode, newblock);
  84
  85         bh = sb_bread(sb, loc);
  86         if (!bh) {
  87                 udf_debug("get_pblock(UDF_VIRTUAL_MAP:%p,%d,%d) VAT: %d[%d]\n",
  88                           sb, block, partition, loc, index);
  89                 return 0xFFFFFFFF;
  90         }
  91
  92         loc = le32_to_cpu(((__le32 *)bh->b_data)[index]);
  93
  94         brelse(bh);
  95
  96 translate:
  97         if (iinfo->i_location.partitionReferenceNum == partition) {
  98                 udf_debug("recursive call to udf_get_pblock!\n");
  99                 return 0xFFFFFFFF;
 100         }
 101
 102         return udf_get_pblock(sb, loc,
 103                               iinfo->i_location.partitionReferenceNum,
 104                               offset);
 105 }
 106
 107 inline uint32_t udf_get_pblock_virt20(struct super_block *sb, uint32_t block,
 108                                       uint16_t partition, uint32_t offset)
 109 {
 110         return udf_get_pblock_virt15(sb, block, partition, offset);
 111 }
 112
 113 uint32_t udf_get_pblock_spar15(struct super_block *sb, uint32_t block,
 114                                uint16_t partition, uint32_t offset)
 115 {
 116         int i;
 117         struct sparingTable *st = NULL;
 118         struct udf_sb_info *sbi = UDF_SB(sb);
 119         struct udf_part_map *map;
 120         uint32_t packet;
 121         struct udf_sparing_data *sdata;
 122
 123         map = &sbi->s_partmaps[partition];
 124         sdata = &map->s_type_specific.s_sparing;
 125         packet = (block + offset) & ~(sdata->s_packet_len - 1);
 126
 127         for (i = 0; i < 4; i++) {
 128                 if (sdata->s_spar_map[i] != NULL) {
 129                         st = (struct sparingTable *)
 130                                         sdata->s_spar_map[i]->b_data;
 131                         break;
 132                 }
 133         }
 134
 135         if (st) {
 136                 for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {
 137                         struct sparingEntry *entry = &st->mapEntry[i];
 138                         u32 origLoc = le32_to_cpu(entry->origLocation);
 139                         if (origLoc >= 0xFFFFFFF0)
 140                                 break;
 141                         else if (origLoc == packet)
 142                                 return le32_to_cpu(entry->mappedLocation) +
 143                                         ((block + offset) &
 144                                                 (sdata->s_packet_len - 1));
 145                         else if (origLoc > packet)
 146                                 break;
 147                 }
 148         }
 149
 150         return map->s_partition_root + block + offset;
 151 }
 152
 153 int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
 154 {
 155         struct udf_sparing_data *sdata;
 156         struct sparingTable *st = NULL;
 157         struct sparingEntry mapEntry;
 158         uint32_t packet;
 159         int i, j, k, l;
 160         struct udf_sb_info *sbi = UDF_SB(sb);
 161         u16 reallocationTableLen;
 162         struct buffer_head *bh;
 163
 164         for (i = 0; i < sbi->s_partitions; i++) {
 165                 struct udf_part_map *map = &sbi->s_partmaps[i];
 166                 if (old_block > map->s_partition_root &&
 167                     old_block < map->s_partition_root + map->s_partition_len) {
 168                         sdata = &map->s_type_specific.s_sparing;
 169                         packet = (old_block - map->s_partition_root) &
 170                                                 ~(sdata->s_packet_len - 1);
 171
 172                         for (j = 0; j < 4; j++)
 173                                 if (sdata->s_spar_map[j] != NULL) {
 174                                         st = (struct sparingTable *)
 175                                                 sdata->s_spar_map[j]->b_data;
 176                                         break;
 177                                 }
 178
 179                         if (!st)
 180                                 return 1;
 181
 182                         reallocationTableLen =
 183                                         le16_to_cpu(st->reallocationTableLen);
 184                         for (k = 0; k < reallocationTableLen; k++) {
 185                                 struct sparingEntry *entry = &st->mapEntry[k];
 186                                 u32 origLoc = le32_to_cpu(entry->origLocation);
 187
 188                                 if (origLoc == 0xFFFFFFFF) {
 189                                         for (; j < 4; j++) {
 190                                                 int len;
 191                                                 bh = sdata->s_spar_map[j];
 192                                                 if (!bh)
 193                                                         continue;
 194
 195                                                 st = (struct sparingTable *)
 196                                                                 bh->b_data;
 197                                                 entry->origLocation =
 198                                                         cpu_to_le32(packet);
 199                                                 len =
 200                                                   sizeof(struct sparingTable) +
 201                                                   reallocationTableLen *
 202                                                   sizeof(struct sparingEntry);
 203                                                 udf_update_tag((char *)st, len);
 204                                                 mark_buffer_dirty(bh);
 205                                         }
 206                                         *new_block = le32_to_cpu(
 207                                                         entry->mappedLocation) +
 208                                                      ((old_block -
 209                                                         map->s_partition_root) &
 210                                                      (sdata->s_packet_len - 1));
 211                                         return 0;
 212                                 } else if (origLoc == packet) {
 213                                         *new_block = le32_to_cpu(
 214                                                         entry->mappedLocation) +
 215                                                      ((old_block -
 216                                                         map->s_partition_root) &
 217                                                      (sdata->s_packet_len - 1));
 218                                         return 0;
 219                                 } else if (origLoc > packet)
 220                                         break;
 221                         }
 222
 223                         for (l = k; l < reallocationTableLen; l++) {
 224                                 struct sparingEntry *entry = &st->mapEntry[l];
 225                                 u32 origLoc = le32_to_cpu(entry->origLocation);
 226
 227                                 if (origLoc != 0xFFFFFFFF)
 228                                         continue;
 229
 230                                 for (; j < 4; j++) {
 231                                         bh = sdata->s_spar_map[j];
 232                                         if (!bh)
 233                                                 continue;
 234
 235                                         st = (struct sparingTable *)bh->b_data;
 236                                         mapEntry = st->mapEntry[l];
 237                                         mapEntry.origLocation =
 238                                                         cpu_to_le32(packet);
 239                                         memmove(&st->mapEntry[k + 1],
 240                                                 &st->mapEntry[k],
 241                                                 (l - k) *
 242                                                 sizeof(struct sparingEntry));
 243                                         st->mapEntry[k] = mapEntry;
 244                                         udf_update_tag((char *)st,
 245                                                 sizeof(struct sparingTable) +
 246                                                 reallocationTableLen *
 247                                                 sizeof(struct sparingEntry));
 248                                         mark_buffer_dirty(bh);
 249                                 }
 250                                 *new_block =
 251                                         le32_to_cpu(
 252                                               st->mapEntry[k].mappedLocation) +
 253                                         ((old_block - map->s_partition_root) &
 254                                          (sdata->s_packet_len - 1));
 255                                 return 0;
 256                         }
 257
 258                         return 1;
 259                 } /* if old_block */
 260         }
 261
 262         if (i == sbi->s_partitions) {
 263                 /* outside of partitions */
 264                 /* for now, fail =) */
 265                 return 1;
 266         }
 267
 268         return 0;
 269 }
 270
 271 static uint32_t udf_try_read_meta(struct inode *inode, uint32_t block,
 272                                         uint16_t partition, uint32_t offset)
 273 {
 274         struct super_block *sb = inode->i_sb;
 275         struct udf_part_map *map;
 276         struct kernel_lb_addr eloc;
 277         uint32_t elen;
 278         sector_t ext_offset;
 279         struct extent_position epos = {};
 280         uint32_t phyblock;
 281
 282         if (inode_bmap(inode, block, &epos, &eloc, &elen, &ext_offset) !=
 283                                                 (EXT_RECORDED_ALLOCATED >> 30))
 284                 phyblock = 0xFFFFFFFF;
 285         else {
 286                 map = &UDF_SB(sb)->s_partmaps[partition];
 287                 /* map to sparable/physical partition desc */
 288                 phyblock = udf_get_pblock(sb, eloc.logicalBlockNum,
 289                         map->s_partition_num, ext_offset + offset);
 290         }
 291
 292         brelse(epos.bh);
 293         return phyblock;
 294 }
 295
 296 uint32_t udf_get_pblock_meta25(struct super_block *sb, uint32_t block,
 297                                 uint16_t partition, uint32_t offset)
 298 {
 299         struct udf_sb_info *sbi = UDF_SB(sb);
 300         struct udf_part_map *map;
 301         struct udf_meta_data *mdata;
 302         uint32_t retblk;
 303         struct inode *inode;
 304
 305         udf_debug("READING from METADATA\n");
 306
 307         map = &sbi->s_partmaps[partition];
 308         mdata = &map->s_type_specific.s_metadata;
 309         inode = mdata->s_metadata_fe ? : mdata->s_mirror_fe;
 310
 311         /* We shouldn't mount such media... */
 312         BUG_ON(!inode);
 313         retblk = udf_try_read_meta(inode, block, partition, offset);
 314         if (retblk == 0xFFFFFFFF) {
 315                 udf_warning(sb, __func__, "error reading from METADATA, "
 316                         "trying to read from MIRROR");
 317                 inode = mdata->s_mirror_fe;
 318                 if (!inode)
 319                         return 0xFFFFFFFF;
 320                 retblk = udf_try_read_meta(inode, block, partition, offset);
 321         }
 322
 323         return retblk;
 324 }