| 1 | /* |
| 2 | * modified for Lites 1.1 |
| 3 | * |
| 4 | * Aug 1995, Godmar Back (gback@cs.utah.edu) |
| 5 | * University of Utah, Department of Computer Science |
| 6 | * |
| 7 | * $FreeBSD: src/sys/gnu/ext2fs/ext2_linux_balloc.c,v 1.11.2.3 2001/08/14 18:03:19 gallatin Exp $ |
| 8 | */ |
| 9 | /* |
| 10 | * linux/fs/ext2/balloc.c |
| 11 | * |
| 12 | * Copyright (C) 1992, 1993, 1994, 1995 |
| 13 | * Remy Card (card@masi.ibp.fr) |
| 14 | * Laboratoire MASI - Institut Blaise Pascal |
| 15 | * Universite Pierre et Marie Curie (Paris VI) |
| 16 | * |
| 17 | * Enhanced block allocation by Stephen Tweedie (sct@dcs.ed.ac.uk), 1993 |
| 18 | */ |
| 19 | |
| 20 | /* |
| 21 | * The free blocks are managed by bitmaps. A file system contains several |
| 22 | * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap |
| 23 | * block for inodes, N blocks for the inode table and data blocks. |
| 24 | * |
| 25 | * The file system contains group descriptors which are located after the |
| 26 | * super block. Each descriptor contains the number of the bitmap block and |
| 27 | * the free blocks count in the block. The descriptors are loaded in memory |
| 28 | * when a file system is mounted (see ext2_read_super). |
| 29 | */ |
| 30 | |
| 31 | #include <sys/param.h> |
| 32 | #include <sys/systm.h> |
| 33 | #include <sys/buf.h> |
| 34 | #include <sys/proc.h> |
| 35 | #include <sys/mount.h> |
| 36 | #include <sys/vnode.h> |
| 37 | |
| 38 | #include <ufs/ufs/quota.h> |
| 39 | #include <ufs/ufs/ufsmount.h> |
| 40 | #include <gnu/ext2fs/ext2_extern.h> |
| 41 | #include <gnu/ext2fs/ext2_fs.h> |
| 42 | #include <gnu/ext2fs/ext2_fs_sb.h> |
| 43 | #include <gnu/ext2fs/fs.h> |
| 44 | |
| 45 | #ifdef __i386__ |
| 46 | #include <gnu/ext2fs/i386-bitops.h> |
| 47 | #elif defined (__alpha__) |
| 48 | #include <gnu/ext2fs/alpha-bitops.h> |
| 49 | #else |
| 50 | #error Provide an bitops.h file, please ! |
| 51 | #endif |
| 52 | |
| 53 | #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) |
| 54 | |
| 55 | /* got rid of get_group_desc since it can already be found in |
| 56 | * ext2_linux_ialloc.c |
| 57 | */ |
| 58 | |
| 59 | static void read_block_bitmap (struct mount * mp, |
| 60 | unsigned int block_group, |
| 61 | unsigned long bitmap_nr) |
| 62 | { |
| 63 | struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs; |
| 64 | struct ext2_group_desc * gdp; |
| 65 | struct buffer_head * bh; |
| 66 | int error; |
| 67 | |
| 68 | gdp = get_group_desc (mp, block_group, NULL); |
| 69 | if ((error = bread (VFSTOUFS(mp)->um_devvp, |
| 70 | fsbtodb(sb, gdp->bg_block_bitmap),sb->s_blocksize, NOCRED, &bh)) != 0) |
| 71 | panic ( "read_block_bitmap: " |
| 72 | "Cannot read block bitmap - " |
| 73 | "block_group = %d, block_bitmap = %lu", |
| 74 | block_group, (unsigned long) gdp->bg_block_bitmap); |
| 75 | sb->s_block_bitmap_number[bitmap_nr] = block_group; |
| 76 | sb->s_block_bitmap[bitmap_nr] = bh; |
| 77 | LCK_BUF(bh) |
| 78 | } |
| 79 | |
| 80 | /* |
| 81 | * load_block_bitmap loads the block bitmap for a blocks group |
| 82 | * |
| 83 | * It maintains a cache for the last bitmaps loaded. This cache is managed |
| 84 | * with a LRU algorithm. |
| 85 | * |
| 86 | * Notes: |
| 87 | * 1/ There is one cache per mounted file system. |
| 88 | * 2/ If the file system contains less than EXT2_MAX_GROUP_LOADED groups, |
| 89 | * this function reads the bitmap without maintaining a LRU cache. |
| 90 | */ |
| 91 | static int load__block_bitmap (struct mount * mp, |
| 92 | unsigned int block_group) |
| 93 | { |
| 94 | int i, j; |
| 95 | struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs; |
| 96 | unsigned long block_bitmap_number; |
| 97 | struct buffer_head * block_bitmap; |
| 98 | |
| 99 | if (block_group >= sb->s_groups_count) |
| 100 | panic ( "load_block_bitmap: " |
| 101 | "block_group >= groups_count - " |
| 102 | "block_group = %d, groups_count = %lu", |
| 103 | block_group, sb->s_groups_count); |
| 104 | |
| 105 | if (sb->s_groups_count <= EXT2_MAX_GROUP_LOADED) { |
| 106 | if (sb->s_block_bitmap[block_group]) { |
| 107 | if (sb->s_block_bitmap_number[block_group] != |
| 108 | block_group) |
| 109 | panic ( "load_block_bitmap: " |
| 110 | "block_group != block_bitmap_number"); |
| 111 | else |
| 112 | return block_group; |
| 113 | } else { |
| 114 | read_block_bitmap (mp, block_group, block_group); |
| 115 | return block_group; |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | for (i = 0; i < sb->s_loaded_block_bitmaps && |
| 120 | sb->s_block_bitmap_number[i] != block_group; i++) |
| 121 | ; |
| 122 | if (i < sb->s_loaded_block_bitmaps && |
| 123 | sb->s_block_bitmap_number[i] == block_group) { |
| 124 | block_bitmap_number = sb->s_block_bitmap_number[i]; |
| 125 | block_bitmap = sb->s_block_bitmap[i]; |
| 126 | for (j = i; j > 0; j--) { |
| 127 | sb->s_block_bitmap_number[j] = |
| 128 | sb->s_block_bitmap_number[j - 1]; |
| 129 | sb->s_block_bitmap[j] = |
| 130 | sb->s_block_bitmap[j - 1]; |
| 131 | } |
| 132 | sb->s_block_bitmap_number[0] = block_bitmap_number; |
| 133 | sb->s_block_bitmap[0] = block_bitmap; |
| 134 | } else { |
| 135 | if (sb->s_loaded_block_bitmaps < EXT2_MAX_GROUP_LOADED) |
| 136 | sb->s_loaded_block_bitmaps++; |
| 137 | else |
| 138 | ULCK_BUF(sb->s_block_bitmap[EXT2_MAX_GROUP_LOADED - 1]) |
| 139 | |
| 140 | for (j = sb->s_loaded_block_bitmaps - 1; j > 0; j--) { |
| 141 | sb->s_block_bitmap_number[j] = |
| 142 | sb->s_block_bitmap_number[j - 1]; |
| 143 | sb->s_block_bitmap[j] = |
| 144 | sb->s_block_bitmap[j - 1]; |
| 145 | } |
| 146 | read_block_bitmap (mp, block_group, 0); |
| 147 | } |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | static __inline int load_block_bitmap (struct mount * mp, |
| 152 | unsigned int block_group) |
| 153 | { |
| 154 | struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs; |
| 155 | if (sb->s_loaded_block_bitmaps > 0 && |
| 156 | sb->s_block_bitmap_number[0] == block_group) |
| 157 | return 0; |
| 158 | |
| 159 | if (sb->s_groups_count <= EXT2_MAX_GROUP_LOADED && |
| 160 | sb->s_block_bitmap_number[block_group] == block_group && |
| 161 | sb->s_block_bitmap[block_group]) |
| 162 | return block_group; |
| 163 | |
| 164 | return load__block_bitmap (mp, block_group); |
| 165 | } |
| 166 | |
| 167 | void ext2_free_blocks (struct mount * mp, unsigned long block, |
| 168 | unsigned long count) |
| 169 | { |
| 170 | struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs; |
| 171 | struct buffer_head * bh; |
| 172 | struct buffer_head * bh2; |
| 173 | unsigned long block_group; |
| 174 | unsigned long bit; |
| 175 | unsigned long i; |
| 176 | int bitmap_nr; |
| 177 | struct ext2_group_desc * gdp; |
| 178 | struct ext2_super_block * es = sb->s_es; |
| 179 | |
| 180 | if (!sb) { |
| 181 | printf ("ext2_free_blocks: nonexistent device"); |
| 182 | return; |
| 183 | } |
| 184 | lock_super (VFSTOUFS(mp)->um_devvp); |
| 185 | if (block < es->s_first_data_block || |
| 186 | (block + count) > es->s_blocks_count) { |
| 187 | printf ( "ext2_free_blocks: " |
| 188 | "Freeing blocks not in datazone - " |
| 189 | "block = %lu, count = %lu", block, count); |
| 190 | unlock_super (VFSTOUFS(mp)->um_devvp); |
| 191 | return; |
| 192 | } |
| 193 | |
| 194 | ext2_debug ("freeing blocks %lu to %lu\n", block, block+count-1); |
| 195 | |
| 196 | block_group = (block - es->s_first_data_block) / |
| 197 | EXT2_BLOCKS_PER_GROUP(sb); |
| 198 | bit = (block - es->s_first_data_block) % EXT2_BLOCKS_PER_GROUP(sb); |
| 199 | if (bit + count > EXT2_BLOCKS_PER_GROUP(sb)) |
| 200 | panic ( "ext2_free_blocks: " |
| 201 | "Freeing blocks across group boundary - " |
| 202 | "Block = %lu, count = %lu", |
| 203 | block, count); |
| 204 | bitmap_nr = load_block_bitmap (mp, block_group); |
| 205 | bh = sb->s_block_bitmap[bitmap_nr]; |
| 206 | gdp = get_group_desc (mp, block_group, &bh2); |
| 207 | |
| 208 | if (/* test_opt (sb, CHECK_STRICT) && assume always strict ! */ |
| 209 | (in_range (gdp->bg_block_bitmap, block, count) || |
| 210 | in_range (gdp->bg_inode_bitmap, block, count) || |
| 211 | in_range (block, gdp->bg_inode_table, |
| 212 | sb->s_itb_per_group) || |
| 213 | in_range (block + count - 1, gdp->bg_inode_table, |
| 214 | sb->s_itb_per_group))) |
| 215 | panic ( "ext2_free_blocks: " |
| 216 | "Freeing blocks in system zones - " |
| 217 | "Block = %lu, count = %lu", |
| 218 | block, count); |
| 219 | |
| 220 | for (i = 0; i < count; i++) { |
| 221 | if (!clear_bit (bit + i, bh->b_data)) |
| 222 | printf ("ext2_free_blocks: " |
| 223 | "bit already cleared for block %lu", |
| 224 | block); |
| 225 | else { |
| 226 | gdp->bg_free_blocks_count++; |
| 227 | es->s_free_blocks_count++; |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | mark_buffer_dirty(bh2); |
| 232 | mark_buffer_dirty(bh); |
| 233 | /**** |
| 234 | if (sb->s_flags & MS_SYNCHRONOUS) { |
| 235 | ll_rw_block (WRITE, 1, &bh); |
| 236 | wait_on_buffer (bh); |
| 237 | } |
| 238 | ****/ |
| 239 | sb->s_dirt = 1; |
| 240 | unlock_super (VFSTOUFS(mp)->um_devvp); |
| 241 | return; |
| 242 | } |
| 243 | |
| 244 | /* |
| 245 | * ext2_new_block uses a goal block to assist allocation. If the goal is |
| 246 | * free, or there is a free block within 32 blocks of the goal, that block |
| 247 | * is allocated. Otherwise a forward search is made for a free block; within |
| 248 | * each block group the search first looks for an entire free byte in the block |
| 249 | * bitmap, and then for any free bit if that fails. |
| 250 | */ |
| 251 | int ext2_new_block (struct mount * mp, unsigned long goal, |
| 252 | u_int32_t * prealloc_count, |
| 253 | u_int32_t * prealloc_block) |
| 254 | { |
| 255 | struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs; |
| 256 | struct buffer_head * bh; |
| 257 | struct buffer_head * bh2; |
| 258 | char * p, * r; |
| 259 | int i, j, k, tmp; |
| 260 | int bitmap_nr; |
| 261 | struct ext2_group_desc * gdp; |
| 262 | struct ext2_super_block * es = sb->s_es; |
| 263 | |
| 264 | #ifdef EXT2FS_DEBUG |
| 265 | static int goal_hits = 0, goal_attempts = 0; |
| 266 | #endif |
| 267 | if (!sb) { |
| 268 | printf ("ext2_new_block: nonexistent device"); |
| 269 | return 0; |
| 270 | } |
| 271 | lock_super (VFSTOUFS(mp)->um_devvp); |
| 272 | |
| 273 | ext2_debug ("goal=%lu.\n", goal); |
| 274 | |
| 275 | repeat: |
| 276 | /* |
| 277 | * First, test whether the goal block is free. |
| 278 | */ |
| 279 | if (goal < es->s_first_data_block || goal >= es->s_blocks_count) |
| 280 | goal = es->s_first_data_block; |
| 281 | i = (goal - es->s_first_data_block) / EXT2_BLOCKS_PER_GROUP(sb); |
| 282 | gdp = get_group_desc (mp, i, &bh2); |
| 283 | if (gdp->bg_free_blocks_count > 0) { |
| 284 | j = ((goal - es->s_first_data_block) % EXT2_BLOCKS_PER_GROUP(sb)); |
| 285 | #ifdef EXT2FS_DEBUG |
| 286 | if (j) |
| 287 | goal_attempts++; |
| 288 | #endif |
| 289 | bitmap_nr = load_block_bitmap (mp, i); |
| 290 | bh = sb->s_block_bitmap[bitmap_nr]; |
| 291 | |
| 292 | ext2_debug ("goal is at %d:%d.\n", i, j); |
| 293 | |
| 294 | if (!test_bit(j, bh->b_data)) { |
| 295 | #ifdef EXT2FS_DEBUG |
| 296 | goal_hits++; |
| 297 | ext2_debug ("goal bit allocated.\n"); |
| 298 | #endif |
| 299 | goto got_block; |
| 300 | } |
| 301 | if (j) { |
| 302 | /* |
| 303 | * The goal was occupied; search forward for a free |
| 304 | * block within the next XX blocks. |
| 305 | * |
| 306 | * end_goal is more or less random, but it has to be |
| 307 | * less than EXT2_BLOCKS_PER_GROUP. Aligning up to the |
| 308 | * next 64-bit boundary is simple.. |
| 309 | */ |
| 310 | int end_goal = (j + 63) & ~63; |
| 311 | j = find_next_zero_bit(bh->b_data, end_goal, j); |
| 312 | if (j < end_goal) |
| 313 | goto got_block; |
| 314 | } |
| 315 | |
| 316 | ext2_debug ("Bit not found near goal\n"); |
| 317 | |
| 318 | /* |
| 319 | * There has been no free block found in the near vicinity |
| 320 | * of the goal: do a search forward through the block groups, |
| 321 | * searching in each group first for an entire free byte in |
| 322 | * the bitmap and then for any free bit. |
| 323 | * |
| 324 | * Search first in the remainder of the current group; then, |
| 325 | * cyclicly search through the rest of the groups. |
| 326 | */ |
| 327 | p = ((char *) bh->b_data) + (j >> 3); |
| 328 | r = memscan(p, 0, (EXT2_BLOCKS_PER_GROUP(sb) - j + 7) >> 3); |
| 329 | k = (r - ((char *) bh->b_data)) << 3; |
| 330 | if (k < EXT2_BLOCKS_PER_GROUP(sb)) { |
| 331 | j = k; |
| 332 | goto search_back; |
| 333 | } |
| 334 | k = find_next_zero_bit ((unsigned long *) bh->b_data, |
| 335 | EXT2_BLOCKS_PER_GROUP(sb), |
| 336 | j); |
| 337 | if (k < EXT2_BLOCKS_PER_GROUP(sb)) { |
| 338 | j = k; |
| 339 | goto got_block; |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | ext2_debug ("Bit not found in block group %d.\n", i); |
| 344 | |
| 345 | /* |
| 346 | * Now search the rest of the groups. We assume that |
| 347 | * i and gdp correctly point to the last group visited. |
| 348 | */ |
| 349 | for (k = 0; k < sb->s_groups_count; k++) { |
| 350 | i++; |
| 351 | if (i >= sb->s_groups_count) |
| 352 | i = 0; |
| 353 | gdp = get_group_desc (mp, i, &bh2); |
| 354 | if (gdp->bg_free_blocks_count > 0) |
| 355 | break; |
| 356 | } |
| 357 | if (k >= sb->s_groups_count) { |
| 358 | unlock_super (VFSTOUFS(mp)->um_devvp); |
| 359 | return 0; |
| 360 | } |
| 361 | bitmap_nr = load_block_bitmap (mp, i); |
| 362 | bh = sb->s_block_bitmap[bitmap_nr]; |
| 363 | r = memscan(bh->b_data, 0, EXT2_BLOCKS_PER_GROUP(sb) >> 3); |
| 364 | j = (r - bh->b_data) << 3; |
| 365 | |
| 366 | if (j < EXT2_BLOCKS_PER_GROUP(sb)) |
| 367 | goto search_back; |
| 368 | else |
| 369 | j = find_first_zero_bit ((unsigned long *) bh->b_data, |
| 370 | EXT2_BLOCKS_PER_GROUP(sb)); |
| 371 | if (j >= EXT2_BLOCKS_PER_GROUP(sb)) { |
| 372 | printf ( "ext2_new_block: " |
| 373 | "Free blocks count corrupted for block group %d", i); |
| 374 | unlock_super (VFSTOUFS(mp)->um_devvp); |
| 375 | return 0; |
| 376 | } |
| 377 | |
| 378 | search_back: |
| 379 | /* |
| 380 | * We have succeeded in finding a free byte in the block |
| 381 | * bitmap. Now search backwards up to 7 bits to find the |
| 382 | * start of this group of free blocks. |
| 383 | */ |
| 384 | for (k = 0; k < 7 && j > 0 && !test_bit (j - 1, bh->b_data); k++, j--); |
| 385 | |
| 386 | got_block: |
| 387 | |
| 388 | ext2_debug ("using block group %d(%d)\n", i, gdp->bg_free_blocks_count); |
| 389 | |
| 390 | tmp = j + i * EXT2_BLOCKS_PER_GROUP(sb) + es->s_first_data_block; |
| 391 | |
| 392 | if (/* test_opt (sb, CHECK_STRICT) && we are always strict. */ |
| 393 | (tmp == gdp->bg_block_bitmap || |
| 394 | tmp == gdp->bg_inode_bitmap || |
| 395 | in_range (tmp, gdp->bg_inode_table, sb->s_itb_per_group))) |
| 396 | panic ( "ext2_new_block: " |
| 397 | "Allocating block in system zone - " |
| 398 | "%dth block = %u in group %u", j, tmp, i); |
| 399 | |
| 400 | if (set_bit (j, bh->b_data)) { |
| 401 | printf ( "ext2_new_block: " |
| 402 | "bit already set for block %d", j); |
| 403 | goto repeat; |
| 404 | } |
| 405 | |
| 406 | ext2_debug ("found bit %d\n", j); |
| 407 | |
| 408 | /* |
| 409 | * Do block preallocation now if required. |
| 410 | */ |
| 411 | #ifdef EXT2_PREALLOCATE |
| 412 | if (prealloc_block) { |
| 413 | *prealloc_count = 0; |
| 414 | *prealloc_block = tmp + 1; |
| 415 | for (k = 1; |
| 416 | k < 8 && (j + k) < EXT2_BLOCKS_PER_GROUP(sb); k++) { |
| 417 | if (set_bit (j + k, bh->b_data)) |
| 418 | break; |
| 419 | (*prealloc_count)++; |
| 420 | } |
| 421 | gdp->bg_free_blocks_count -= *prealloc_count; |
| 422 | es->s_free_blocks_count -= *prealloc_count; |
| 423 | ext2_debug ("Preallocated a further %lu bits.\n", |
| 424 | *prealloc_count); |
| 425 | } |
| 426 | #endif |
| 427 | |
| 428 | j = tmp; |
| 429 | |
| 430 | mark_buffer_dirty(bh); |
| 431 | /**** |
| 432 | if (sb->s_flags & MS_SYNCHRONOUS) { |
| 433 | ll_rw_block (WRITE, 1, &bh); |
| 434 | wait_on_buffer (bh); |
| 435 | } |
| 436 | ****/ |
| 437 | if (j >= es->s_blocks_count) { |
| 438 | printf ( "ext2_new_block: " |
| 439 | "block >= blocks count - " |
| 440 | "block_group = %d, block=%d", i, j); |
| 441 | unlock_super (VFSTOUFS(mp)->um_devvp); |
| 442 | return 0; |
| 443 | } |
| 444 | |
| 445 | ext2_debug ("allocating block %d. " |
| 446 | "Goal hits %d of %d.\n", j, goal_hits, goal_attempts); |
| 447 | |
| 448 | gdp->bg_free_blocks_count--; |
| 449 | mark_buffer_dirty(bh2); |
| 450 | es->s_free_blocks_count--; |
| 451 | sb->s_dirt = 1; |
| 452 | unlock_super (VFSTOUFS(mp)->um_devvp); |
| 453 | return j; |
| 454 | } |
| 455 | |
| 456 | #ifdef unused |
| 457 | static unsigned long ext2_count_free_blocks (struct mount * mp) |
| 458 | { |
| 459 | struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs; |
| 460 | #ifdef EXT2FS_DEBUG |
| 461 | struct ext2_super_block * es; |
| 462 | unsigned long desc_count, bitmap_count, x; |
| 463 | int bitmap_nr; |
| 464 | struct ext2_group_desc * gdp; |
| 465 | int i; |
| 466 | |
| 467 | lock_super (VFSTOUFS(mp)->um_devvp); |
| 468 | es = sb->s_es; |
| 469 | desc_count = 0; |
| 470 | bitmap_count = 0; |
| 471 | gdp = NULL; |
| 472 | for (i = 0; i < sb->s_groups_count; i++) { |
| 473 | gdp = get_group_desc (mp, i, NULL); |
| 474 | desc_count += gdp->bg_free_blocks_count; |
| 475 | bitmap_nr = load_block_bitmap (mp, i); |
| 476 | x = ext2_count_free (sb->s_block_bitmap[bitmap_nr], |
| 477 | sb->s_blocksize); |
| 478 | ext2_debug ("group %d: stored = %d, counted = %lu\n", |
| 479 | i, gdp->bg_free_blocks_count, x); |
| 480 | bitmap_count += x; |
| 481 | } |
| 482 | ext2_debug( "stored = %lu, computed = %lu, %lu\n", |
| 483 | es->s_free_blocks_count, desc_count, bitmap_count); |
| 484 | unlock_super (VFSTOUFS(mp)->um_devvp); |
| 485 | return bitmap_count; |
| 486 | #else |
| 487 | return sb->s_es->s_free_blocks_count; |
| 488 | #endif |
| 489 | } |
| 490 | #endif /* unused */ |
| 491 | |
| 492 | static __inline int block_in_use (unsigned long block, |
| 493 | struct ext2_sb_info * sb, |
| 494 | unsigned char * map) |
| 495 | { |
| 496 | return test_bit ((block - sb->s_es->s_first_data_block) % |
| 497 | EXT2_BLOCKS_PER_GROUP(sb), map); |
| 498 | } |
| 499 | |
| 500 | static int test_root(int a, int b) |
| 501 | { |
| 502 | if (a == 0) |
| 503 | return 1; |
| 504 | while (1) { |
| 505 | if (a == 1) |
| 506 | return 1; |
| 507 | if (a % b) |
| 508 | return 0; |
| 509 | a = a / b; |
| 510 | } |
| 511 | } |
| 512 | |
| 513 | int ext2_group_sparse(int group) |
| 514 | { |
| 515 | return (test_root(group, 3) || test_root(group, 5) || |
| 516 | test_root(group, 7)); |
| 517 | } |
| 518 | |
| 519 | #ifdef unused |
| 520 | static void ext2_check_blocks_bitmap (struct mount * mp) |
| 521 | { |
| 522 | struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs; |
| 523 | struct buffer_head * bh; |
| 524 | struct ext2_super_block * es; |
| 525 | unsigned long desc_count, bitmap_count, x; |
| 526 | unsigned long desc_blocks; |
| 527 | int bitmap_nr; |
| 528 | struct ext2_group_desc * gdp; |
| 529 | int i, j; |
| 530 | |
| 531 | lock_super (VFSTOUFS(mp)->um_devvp); |
| 532 | es = sb->s_es; |
| 533 | desc_count = 0; |
| 534 | bitmap_count = 0; |
| 535 | gdp = NULL; |
| 536 | desc_blocks = (sb->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / |
| 537 | EXT2_DESC_PER_BLOCK(sb); |
| 538 | for (i = 0; i < sb->s_groups_count; i++) { |
| 539 | gdp = get_group_desc (mp, i, NULL); |
| 540 | desc_count += gdp->bg_free_blocks_count; |
| 541 | bitmap_nr = load_block_bitmap (mp, i); |
| 542 | bh = sb->s_block_bitmap[bitmap_nr]; |
| 543 | |
| 544 | if (!(es->s_feature_ro_compat & |
| 545 | EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER) || |
| 546 | ext2_group_sparse(i)) { |
| 547 | if (!test_bit (0, bh->b_data)) |
| 548 | printf ("ext2_check_blocks_bitmap: " |
| 549 | "Superblock in group %d " |
| 550 | "is marked free", i); |
| 551 | |
| 552 | for (j = 0; j < desc_blocks; j++) |
| 553 | if (!test_bit (j + 1, bh->b_data)) |
| 554 | printf ("ext2_check_blocks_bitmap: " |
| 555 | "Descriptor block #%d in group " |
| 556 | "%d is marked free", j, i); |
| 557 | } |
| 558 | |
| 559 | if (!block_in_use (gdp->bg_block_bitmap, sb, bh->b_data)) |
| 560 | printf ("ext2_check_blocks_bitmap: " |
| 561 | "Block bitmap for group %d is marked free", |
| 562 | i); |
| 563 | |
| 564 | if (!block_in_use (gdp->bg_inode_bitmap, sb, bh->b_data)) |
| 565 | printf ("ext2_check_blocks_bitmap: " |
| 566 | "Inode bitmap for group %d is marked free", |
| 567 | i); |
| 568 | |
| 569 | for (j = 0; j < sb->s_itb_per_group; j++) |
| 570 | if (!block_in_use (gdp->bg_inode_table + j, sb, bh->b_data)) |
| 571 | printf ("ext2_check_blocks_bitmap: " |
| 572 | "Block #%d of the inode table in " |
| 573 | "group %d is marked free", j, i); |
| 574 | |
| 575 | x = ext2_count_free (bh, sb->s_blocksize); |
| 576 | if (gdp->bg_free_blocks_count != x) |
| 577 | printf ("ext2_check_blocks_bitmap: " |
| 578 | "Wrong free blocks count for group %d, " |
| 579 | "stored = %d, counted = %lu", i, |
| 580 | gdp->bg_free_blocks_count, x); |
| 581 | bitmap_count += x; |
| 582 | } |
| 583 | if (es->s_free_blocks_count != bitmap_count) |
| 584 | printf ("ext2_check_blocks_bitmap: " |
| 585 | "Wrong free blocks count in super block, " |
| 586 | "stored = %lu, counted = %lu", |
| 587 | (unsigned long) es->s_free_blocks_count, bitmap_count); |
| 588 | unlock_super (VFSTOUFS(mp)->um_devvp); |
| 589 | } |
| 590 | #endif /* unused */ |
| 591 | |
| 592 | /* |
| 593 | * this function is taken from |
| 594 | * linux/fs/ext2/bitmap.c |
| 595 | */ |
| 596 | |
| 597 | static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0}; |
| 598 | |
| 599 | unsigned long ext2_count_free (struct buffer_head * map, unsigned int numchars) |
| 600 | { |
| 601 | unsigned int i; |
| 602 | unsigned long sum = 0; |
| 603 | |
| 604 | if (!map) |
| 605 | return (0); |
| 606 | for (i = 0; i < numchars; i++) |
| 607 | sum += nibblemap[map->b_data[i] & 0xf] + |
| 608 | nibblemap[(map->b_data[i] >> 4) & 0xf]; |
| 609 | return (sum); |
| 610 | } |