lib/ext2fs/blknum.c

   1 /*
   2  * blknum.c --- Functions to handle blk64_t and high/low 64-bit block
   3  * number.
   4  *
   5  * Copyright IBM Corporation, 2007
   6  * Author Jose R. Santos <jrs@us.ibm.com>
   7  *
   8  * %Begin-Header%
   9  * This file may be redistributed under the terms of the GNU Public
  10  * License.
  11  * %End-Header%
  12  */
  13
  14 #include "config.h"
  15 #include "ext2fs.h"
  16
  17 /*
  18  * Return the group # of a block
  19  */
  20 dgrp_t ext2fs_group_of_blk2(ext2_filsys fs, blk64_t blk)
  21 {
  22         return (blk - fs->super->s_first_data_block) /
  23                 fs->super->s_blocks_per_group;
  24 }
  25
  26 /*
  27  * Return the first block (inclusive) in a group
  28  */
  29 blk64_t ext2fs_group_first_block2(ext2_filsys fs, dgrp_t group)
  30 {
  31         return fs->super->s_first_data_block +
  32                 EXT2_GROUPS_TO_BLOCKS(fs->super, group);
  33 }
  34
  35 /*
  36  * Return the last block (inclusive) in a group
  37  */
  38 blk64_t ext2fs_group_last_block2(ext2_filsys fs, dgrp_t group)
  39 {
  40         return (group == fs->group_desc_count - 1 ?
  41                 ext2fs_blocks_count(fs->super) - 1 :
  42                 ext2fs_group_first_block2(fs, group) +
  43                         (fs->super->s_blocks_per_group - 1));
  44 }
  45
  46 /*
  47  * Return the number of blocks in a group
  48  */
  49 int ext2fs_group_blocks_count(ext2_filsys fs, dgrp_t group)
  50 {
  51         int num_blocks;
  52
  53         if (group == fs->group_desc_count - 1) {
  54                 num_blocks = (ext2fs_blocks_count(fs->super) -
  55                                 fs->super->s_first_data_block) %
  56                               fs->super->s_blocks_per_group;
  57                 if (!num_blocks)
  58                         num_blocks = fs->super->s_blocks_per_group;
  59         } else
  60                 num_blocks = fs->super->s_blocks_per_group;
  61
  62         return num_blocks;
  63 }
  64
  65 /*
  66  * Return the inode data block count
  67  */
  68 blk64_t ext2fs_inode_data_blocks2(ext2_filsys fs,
  69                                         struct ext2_inode *inode)
  70 {
  71         return (inode->i_blocks |
  72                 ((fs->super->s_feature_ro_compat &
  73                   EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ?
  74                  (__u64) inode->osd2.linux2.l_i_blocks_hi << 32 : 0)) -
  75                 (inode->i_file_acl ? fs->blocksize >> 9 : 0);
  76 }
  77
  78 /*
  79  * Return the inode i_blocks count
  80  */
  81 blk64_t ext2fs_inode_i_blocks(ext2_filsys fs,
  82                                         struct ext2_inode *inode)
  83 {
  84         return (inode->i_blocks |
  85                 ((fs->super->s_feature_ro_compat &
  86                   EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ?
  87                  (__u64)inode->osd2.linux2.l_i_blocks_hi << 32 : 0));
  88 }
  89
  90 /*
  91  * Return the fs block count
  92  */
  93 blk64_t ext2fs_blocks_count(struct ext2_super_block *super)
  94 {
  95         return super->s_blocks_count |
  96                 (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT ?
  97                 (__u64) super->s_blocks_count_hi << 32 : 0);
  98 }
  99
 100 /*
 101  * Set the fs block count
 102  */
 103 void ext2fs_blocks_count_set(struct ext2_super_block *super, blk64_t blk)
 104 {
 105         super->s_blocks_count = blk;
 106         if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 107                 super->s_blocks_count_hi = (__u64) blk >> 32;
 108 }
 109
 110 /*
 111  * Add to the current fs block count
 112  */
 113 void ext2fs_blocks_count_add(struct ext2_super_block *super, blk64_t blk)
 114 {
 115         blk64_t tmp;
 116         tmp = ext2fs_blocks_count(super) + blk;
 117         ext2fs_blocks_count_set(super, tmp);
 118 }
 119
 120 /*
 121  * Return the fs reserved block count
 122  */
 123 blk64_t ext2fs_r_blocks_count(struct ext2_super_block *super)
 124 {
 125         return super->s_r_blocks_count |
 126                 (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT ?
 127                 (__u64) super->s_r_blocks_count_hi << 32 : 0);
 128 }
 129
 130 /*
 131  * Set the fs reserved block count
 132  */
 133 void ext2fs_r_blocks_count_set(struct ext2_super_block *super, blk64_t blk)
 134 {
 135         super->s_r_blocks_count = blk;
 136         if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 137                 super->s_r_blocks_count_hi = (__u64) blk >> 32;
 138 }
 139
 140 /*
 141  * Add to the current reserved fs block count
 142  */
 143 void ext2fs_r_blocks_count_add(struct ext2_super_block *super, blk64_t blk)
 144 {
 145         blk64_t tmp;
 146         tmp = ext2fs_r_blocks_count(super) + blk;
 147         ext2fs_r_blocks_count_set(super, tmp);
 148 }
 149
 150 /*
 151  * Return the fs free block count
 152  */
 153 blk64_t ext2fs_free_blocks_count(struct ext2_super_block *super)
 154 {
 155         return super->s_free_blocks_count |
 156                 (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT ?
 157                 (__u64) super->s_free_blocks_hi << 32 : 0);
 158 }
 159
 160 /*
 161  * Set the fs free block count
 162  */
 163 void ext2fs_free_blocks_count_set(struct ext2_super_block *super, blk64_t blk)
 164 {
 165         super->s_free_blocks_count = blk;
 166         if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 167                 super->s_free_blocks_hi = (__u64) blk >> 32;
 168 }
 169
 170 /*
 171  * Add to the current free fs block count
 172  */
 173 void ext2fs_free_blocks_count_add(struct ext2_super_block *super, blk64_t blk)
 174 {
 175         blk64_t tmp;
 176         tmp = ext2fs_free_blocks_count(super) + blk;
 177         ext2fs_free_blocks_count_set(super, tmp);
 178 }
 179
 180 /*
 181  * Get a pointer to a block group descriptor.  We need the explicit
 182  * pointer to the group desc for code that swaps block group
 183  * descriptors before writing them out, as it wants to make a copy and
 184  * do the swap there.
 185  */
 186 struct ext2_group_desc *ext2fs_group_desc(ext2_filsys fs,
 187                                           struct opaque_ext2_group_desc *gdp,
 188                                           dgrp_t group)
 189 {
 190         return (struct ext2_group_desc *)((char *)gdp +
 191                                           group * EXT2_DESC_SIZE(fs->super));
 192 }
 193
 194 /* Do the same but as an ext4 group desc for internal use here */
 195 static struct ext4_group_desc *ext4fs_group_desc(ext2_filsys fs,
 196                                           struct opaque_ext2_group_desc *gdp,
 197                                           dgrp_t group)
 198 {
 199         return (struct ext4_group_desc *)ext2fs_group_desc(fs, gdp, group);
 200 }
 201
 202 /*
 203  * Return the block bitmap checksum of a group
 204  */
 205 __u32 ext2fs_block_bitmap_checksum(ext2_filsys fs, dgrp_t group)
 206 {
 207         struct ext4_group_desc *gdp;
 208         __u32 csum;
 209
 210         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 211         csum = gdp->bg_block_bitmap_csum_lo;
 212         if (fs->super->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION)
 213                 csum |= ((__u32)gdp->bg_block_bitmap_csum_hi << 16);
 214         return csum;
 215 }
 216
 217 /*
 218  * Return the block bitmap block of a group
 219  */
 220 blk64_t ext2fs_block_bitmap_loc(ext2_filsys fs, dgrp_t group)
 221 {
 222         struct ext4_group_desc *gdp;
 223
 224         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 225         return gdp->bg_block_bitmap |
 226                 (fs->super->s_feature_incompat
 227                  & EXT4_FEATURE_INCOMPAT_64BIT ?
 228                  (__u64)gdp->bg_block_bitmap_hi << 32 : 0);
 229 }
 230
 231 /*
 232  * Set the block bitmap block of a group
 233  */
 234 void ext2fs_block_bitmap_loc_set(ext2_filsys fs, dgrp_t group, blk64_t blk)
 235 {
 236         struct ext4_group_desc *gdp;
 237
 238         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 239         gdp->bg_block_bitmap = blk;
 240         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 241                 gdp->bg_block_bitmap_hi = (__u64) blk >> 32;
 242 }
 243
 244 /*
 245  * Return the inode bitmap checksum of a group
 246  */
 247 __u32 ext2fs_inode_bitmap_checksum(ext2_filsys fs, dgrp_t group)
 248 {
 249         struct ext4_group_desc *gdp;
 250         __u32 csum;
 251
 252         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 253         csum = gdp->bg_inode_bitmap_csum_lo;
 254         if (fs->super->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
 255                 csum |= ((__u32)gdp->bg_inode_bitmap_csum_hi << 16);
 256         return csum;
 257 }
 258
 259 /*
 260  * Return the inode bitmap block of a group
 261  */
 262 blk64_t ext2fs_inode_bitmap_loc(ext2_filsys fs, dgrp_t group)
 263 {
 264         struct ext4_group_desc *gdp;
 265
 266         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 267         return gdp->bg_inode_bitmap |
 268                 (fs->super->s_feature_incompat
 269                  & EXT4_FEATURE_INCOMPAT_64BIT ?
 270                  (__u64) gdp->bg_inode_bitmap_hi << 32 : 0);
 271 }
 272
 273 /*
 274  * Set the inode bitmap block of a group
 275  */
 276 void ext2fs_inode_bitmap_loc_set(ext2_filsys fs, dgrp_t group, blk64_t blk)
 277 {
 278         struct ext4_group_desc *gdp;
 279
 280         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 281         gdp->bg_inode_bitmap = blk;
 282         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 283                 gdp->bg_inode_bitmap_hi = (__u64) blk >> 32;
 284 }
 285
 286 /*
 287  * Return the inode table block of a group
 288  */
 289 blk64_t ext2fs_inode_table_loc(ext2_filsys fs, dgrp_t group)
 290 {
 291         struct ext4_group_desc *gdp;
 292
 293         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 294         return gdp->bg_inode_table |
 295                 (fs->super->s_feature_incompat
 296                  & EXT4_FEATURE_INCOMPAT_64BIT ?
 297                  (__u64) gdp->bg_inode_table_hi << 32 : 0);
 298 }
 299
 300 /*
 301  * Set the inode table block of a group
 302  */
 303 void ext2fs_inode_table_loc_set(ext2_filsys fs, dgrp_t group, blk64_t blk)
 304 {
 305         struct ext4_group_desc *gdp;
 306
 307         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 308         gdp->bg_inode_table = blk;
 309         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 310                 gdp->bg_inode_table_hi = (__u64) blk >> 32;
 311 }
 312
 313 /*
 314  * Return the free blocks count of a group
 315  */
 316 __u32 ext2fs_bg_free_blocks_count(ext2_filsys fs, dgrp_t group)
 317 {
 318         struct ext4_group_desc *gdp;
 319
 320         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 321         return gdp->bg_free_blocks_count |
 322                 (fs->super->s_feature_incompat
 323                  & EXT4_FEATURE_INCOMPAT_64BIT ?
 324                  (__u32) gdp->bg_free_blocks_count_hi << 16 : 0);
 325 }
 326
 327 /*
 328  * Set the free blocks count of a group
 329  */
 330 void ext2fs_bg_free_blocks_count_set(ext2_filsys fs, dgrp_t group, __u32 n)
 331 {
 332         struct ext4_group_desc *gdp;
 333
 334         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 335         gdp->bg_free_blocks_count = n;
 336
 337         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 338                 gdp->bg_free_blocks_count_hi = (__u32) n >> 16;
 339 }
 340
 341 /*
 342  * Return the free inodes count of a group
 343  */
 344 __u32 ext2fs_bg_free_inodes_count(ext2_filsys fs, dgrp_t group)
 345 {
 346         struct ext4_group_desc *gdp;
 347
 348         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 349         return gdp->bg_free_inodes_count |
 350                 (fs->super->s_feature_incompat
 351                  & EXT4_FEATURE_INCOMPAT_64BIT ?
 352                  (__u32) gdp->bg_free_inodes_count_hi << 16 : 0);
 353 }
 354
 355 /*
 356  * Set the free inodes count of a group
 357  */
 358 void ext2fs_bg_free_inodes_count_set(ext2_filsys fs, dgrp_t group, __u32 n)
 359 {
 360         struct ext4_group_desc *gdp;
 361
 362         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 363         gdp->bg_free_inodes_count = n;
 364         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 365                 gdp->bg_free_inodes_count_hi = (__u32) n >> 16;
 366 }
 367
 368 /*
 369  * Return the used dirs count of a group
 370  */
 371 __u32 ext2fs_bg_used_dirs_count(ext2_filsys fs, dgrp_t group)
 372 {
 373         struct ext4_group_desc *gdp;
 374
 375         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 376         return gdp->bg_used_dirs_count |
 377                 (fs->super->s_feature_incompat
 378                  & EXT4_FEATURE_INCOMPAT_64BIT ?
 379                  (__u32) gdp->bg_used_dirs_count_hi << 16 : 0);
 380 }
 381
 382 /*
 383  * Set the used dirs count of a group
 384  */
 385 void ext2fs_bg_used_dirs_count_set(ext2_filsys fs, dgrp_t group, __u32 n)
 386 {
 387         struct ext4_group_desc *gdp;
 388
 389         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 390         gdp->bg_used_dirs_count = n;
 391         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 392                 gdp->bg_used_dirs_count_hi = (__u32) n >> 16;
 393 }
 394
 395 /*
 396  * Return the unused inodes count of a group
 397  */
 398 __u32 ext2fs_bg_itable_unused(ext2_filsys fs, dgrp_t group)
 399 {
 400         struct ext4_group_desc *gdp;
 401
 402         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 403         return gdp->bg_itable_unused |
 404                 (fs->super->s_feature_incompat
 405                  & EXT4_FEATURE_INCOMPAT_64BIT ?
 406                  (__u32) gdp->bg_itable_unused_hi << 16 : 0);
 407 }
 408
 409 /*
 410  * Set the unused inodes count of a group
 411  */
 412 void ext2fs_bg_itable_unused_set(ext2_filsys fs, dgrp_t group, __u32 n)
 413 {
 414         struct ext4_group_desc *gdp;
 415
 416         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 417         gdp->bg_itable_unused = n;
 418         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 419                 gdp->bg_itable_unused_hi = (__u32) n >> 16;
 420 }
 421
 422 /*
 423  * Get the flags for this block group
 424  */
 425 __u16 ext2fs_bg_flags(ext2_filsys fs, dgrp_t group)
 426 {
 427         struct ext4_group_desc *gdp;
 428
 429         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 430         return gdp->bg_flags;
 431 }
 432
 433 /*
 434  * Zero out the flags for this block group
 435  */
 436 void ext2fs_bg_flags_zap(ext2_filsys fs, dgrp_t group)
 437 {
 438         struct ext4_group_desc *gdp;
 439
 440         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 441         gdp->bg_flags = 0;
 442         return;
 443 }
 444
 445 /*
 446  * Get the value of a particular flag for this block group
 447  */
 448 int ext2fs_bg_flags_test(ext2_filsys fs, dgrp_t group, __u16 bg_flag)
 449 {
 450         struct ext4_group_desc *gdp;
 451
 452         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 453         return gdp->bg_flags & bg_flag;
 454 }
 455
 456 /*
 457  * Set a flag or set of flags for this block group
 458  */
 459 void ext2fs_bg_flags_set(ext2_filsys fs, dgrp_t group, __u16 bg_flags)
 460 {
 461         struct ext4_group_desc *gdp;
 462
 463         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 464         gdp->bg_flags |= bg_flags;
 465         return;
 466 }
 467
 468 /*
 469  * Clear a flag or set of flags for this block group
 470  */
 471 void ext2fs_bg_flags_clear(ext2_filsys fs, dgrp_t group, __u16 bg_flags)
 472 {
 473         struct ext4_group_desc *gdp;
 474
 475         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 476         gdp->bg_flags &= ~bg_flags;
 477         return;
 478 }
 479
 480 /*
 481  * Get the checksum for this block group
 482  */
 483 __u16 ext2fs_bg_checksum(ext2_filsys fs, dgrp_t group)
 484 {
 485         struct ext4_group_desc *gdp;
 486
 487         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 488         return gdp->bg_checksum;
 489 }
 490
 491 /*
 492  * Set the checksum for this block group to a previously calculated value
 493  */
 494 void ext2fs_bg_checksum_set(ext2_filsys fs, dgrp_t group, __u16 checksum)
 495 {
 496         struct ext4_group_desc *gdp;
 497
 498         gdp = ext4fs_group_desc(fs, fs->group_desc, group);
 499         gdp->bg_checksum = checksum;
 500         return;
 501 }
 502
 503 /*
 504  * Get the acl block of a file
 505  */
 506 blk64_t ext2fs_file_acl_block(ext2_filsys fs, const struct ext2_inode *inode)
 507 {
 508         blk64_t blk = inode->i_file_acl;
 509
 510         if (fs && fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 511                 blk |= ((__u64) inode->osd2.linux2.l_i_file_acl_high) << 32;
 512         return blk;
 513 }
 514
 515 /*
 516  * Set the acl block of a file
 517  */
 518 void ext2fs_file_acl_block_set(ext2_filsys fs, struct ext2_inode *inode,
 519                                blk64_t blk)
 520 {
 521         inode->i_file_acl = blk;
 522         if (fs && fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 523                 inode->osd2.linux2.l_i_file_acl_high = (__u64) blk >> 32;
 524 }
 525