1 /* 2 * linux/fs/ext2/ialloc.c 3 * 4 * Copyright (C) 1992, 1993, 1994, 1995 5 * Remy Card (card@masi.ibp.fr) 6 * Laboratoire MASI - Institut Blaise Pascal 7 * Universite Pierre et Marie Curie (Paris VI) 8 * 9 * BSD ufs-inspired inode and directory allocation by 10 * Stephen Tweedie (sct@dcs.ed.ac.uk), 1993 11 * Big-endian to little-endian byte-swapping/bitmaps by 12 * David S. Miller (davem@caip.rutgers.edu), 1995 13 */ 14 15 #include <linux/quotaops.h> 16 #include <linux/sched.h> 17 #include <linux/backing-dev.h> 18 #include <linux/buffer_head.h> 19 #include <linux/random.h> 20 #include "ext2.h" 21 #include "xattr.h" 22 #include "acl.h" 23 24 /* 25 * ialloc.c contains the inodes allocation and deallocation routines 26 */ 27 28 /* 29 * The free inodes are managed by bitmaps. A file system contains several 30 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap 31 * block for inodes, N blocks for the inode table and data blocks. 32 * 33 * The file system contains group descriptors which are located after the 34 * super block. Each descriptor contains the number of the bitmap block and 35 * the free blocks count in the block. 36 */ 37 38 39 /* 40 * Read the inode allocation bitmap for a given block_group, reading 41 * into the specified slot in the superblock's bitmap cache. 42 * 43 * Return buffer_head of bitmap on success or NULL. 44 */ 45 static struct buffer_head * 46 read_inode_bitmap(struct super_block * sb, unsigned long block_group) 47 { 48 struct ext2_group_desc *desc; 49 struct buffer_head *bh = NULL; 50 51 desc = ext2_get_group_desc(sb, block_group, NULL); 52 if (!desc) 53 goto error_out; 54 55 bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap)); 56 if (!bh) 57 ext2_error(sb, "read_inode_bitmap", 58 "Cannot read inode bitmap - " 59 "block_group = %lu, inode_bitmap = %u", 60 block_group, le32_to_cpu(desc->bg_inode_bitmap)); 61 error_out: 62 return bh; 63 } 64 65 static void ext2_release_inode(struct super_block *sb, int group, int dir) 66 { 67 struct ext2_group_desc * desc; 68 struct buffer_head *bh; 69 70 desc = ext2_get_group_desc(sb, group, &bh); 71 if (!desc) { 72 ext2_error(sb, "ext2_release_inode", 73 "can't get descriptor for group %d", group); 74 return; 75 } 76 77 spin_lock(sb_bgl_lock(EXT2_SB(sb), group)); 78 desc->bg_free_inodes_count = 79 cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) + 1); 80 if (dir) 81 desc->bg_used_dirs_count = 82 cpu_to_le16(le16_to_cpu(desc->bg_used_dirs_count) - 1); 83 spin_unlock(sb_bgl_lock(EXT2_SB(sb), group)); 84 if (dir) 85 percpu_counter_dec(&EXT2_SB(sb)->s_dirs_counter); 86 sb->s_dirt = 1; 87 mark_buffer_dirty(bh); 88 } 89 90 /* 91 * NOTE! When we get the inode, we're the only people 92 * that have access to it, and as such there are no 93 * race conditions we have to worry about. The inode 94 * is not on the hash-lists, and it cannot be reached 95 * through the filesystem because the directory entry 96 * has been deleted earlier. 97 * 98 * HOWEVER: we must make sure that we get no aliases, 99 * which means that we have to call "clear_inode()" 100 * _before_ we mark the inode not in use in the inode 101 * bitmaps. Otherwise a newly created file might use 102 * the same inode number (not actually the same pointer 103 * though), and then we'd have two inodes sharing the 104 * same inode number and space on the harddisk. 105 */ 106 void ext2_free_inode (struct inode * inode) 107 { 108 struct super_block * sb = inode->i_sb; 109 int is_directory; 110 unsigned long ino; 111 struct buffer_head *bitmap_bh = NULL; 112 unsigned long block_group; 113 unsigned long bit; 114 struct ext2_super_block * es; 115 116 ino = inode->i_ino; 117 ext2_debug ("freeing inode %lu\n", ino); 118 119 /* 120 * Note: we must free any quota before locking the superblock, 121 * as writing the quota to disk may need the lock as well. 122 */ 123 if (!is_bad_inode(inode)) { 124 /* Quota is already initialized in iput() */ 125 ext2_xattr_delete_inode(inode); 126 DQUOT_FREE_INODE(inode); 127 DQUOT_DROP(inode); 128 } 129 130 es = EXT2_SB(sb)->s_es; 131 is_directory = S_ISDIR(inode->i_mode); 132 133 /* Do this BEFORE marking the inode not in use or returning an error */ 134 clear_inode (inode); 135 136 if (ino < EXT2_FIRST_INO(sb) || 137 ino > le32_to_cpu(es->s_inodes_count)) { 138 ext2_error (sb, "ext2_free_inode", 139 "reserved or nonexistent inode %lu", ino); 140 goto error_return; 141 } 142 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 143 bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb); 144 brelse(bitmap_bh); 145 bitmap_bh = read_inode_bitmap(sb, block_group); 146 if (!bitmap_bh) 147 goto error_return; 148 149 /* Ok, now we can actually update the inode bitmaps.. */ 150 if (!ext2_clear_bit_atomic(sb_bgl_lock(EXT2_SB(sb), block_group), 151 bit, (void *) bitmap_bh->b_data)) 152 ext2_error (sb, "ext2_free_inode", 153 "bit already cleared for inode %lu", ino); 154 else 155 ext2_release_inode(sb, block_group, is_directory); 156 mark_buffer_dirty(bitmap_bh); 157 if (sb->s_flags & MS_SYNCHRONOUS) 158 sync_dirty_buffer(bitmap_bh); 159 error_return: 160 brelse(bitmap_bh); 161 } 162 163 /* 164 * We perform asynchronous prereading of the new inode's inode block when 165 * we create the inode, in the expectation that the inode will be written 166 * back soon. There are two reasons: 167 * 168 * - When creating a large number of files, the async prereads will be 169 * nicely merged into large reads 170 * - When writing out a large number of inodes, we don't need to keep on 171 * stalling the writes while we read the inode block. 172 * 173 * FIXME: ext2_get_group_desc() needs to be simplified. 174 */ 175 static void ext2_preread_inode(struct inode *inode) 176 { 177 unsigned long block_group; 178 unsigned long offset; 179 unsigned long block; 180 struct ext2_group_desc * gdp; 181 struct backing_dev_info *bdi; 182 183 bdi = inode->i_mapping->backing_dev_info; 184 if (bdi_read_congested(bdi)) 185 return; 186 if (bdi_write_congested(bdi)) 187 return; 188 189 block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 190 gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL); 191 if (gdp == NULL) 192 return; 193 194 /* 195 * Figure out the offset within the block group inode table 196 */ 197 offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) * 198 EXT2_INODE_SIZE(inode->i_sb); 199 block = le32_to_cpu(gdp->bg_inode_table) + 200 (offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb)); 201 sb_breadahead(inode->i_sb, block); 202 } 203 204 /* 205 * There are two policies for allocating an inode. If the new inode is 206 * a directory, then a forward search is made for a block group with both 207 * free space and a low directory-to-inode ratio; if that fails, then of 208 * the groups with above-average free space, that group with the fewest 209 * directories already is chosen. 210 * 211 * For other inodes, search forward from the parent directory\'s block 212 * group to find a free inode. 213 */ 214 static int find_group_dir(struct super_block *sb, struct inode *parent) 215 { 216 int ngroups = EXT2_SB(sb)->s_groups_count; 217 int avefreei = ext2_count_free_inodes(sb) / ngroups; 218 struct ext2_group_desc *desc, *best_desc = NULL; 219 int group, best_group = -1; 220 221 for (group = 0; group < ngroups; group++) { 222 desc = ext2_get_group_desc (sb, group, NULL); 223 if (!desc || !desc->bg_free_inodes_count) 224 continue; 225 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei) 226 continue; 227 if (!best_desc || 228 (le16_to_cpu(desc->bg_free_blocks_count) > 229 le16_to_cpu(best_desc->bg_free_blocks_count))) { 230 best_group = group; 231 best_desc = desc; 232 } 233 } 234 if (!best_desc) 235 return -1; 236 237 return best_group; 238 } 239 240 /* 241 * Orlov's allocator for directories. 242 * 243 * We always try to spread first-level directories. 244 * 245 * If there are blockgroups with both free inodes and free blocks counts 246 * not worse than average we return one with smallest directory count. 247 * Otherwise we simply return a random group. 248 * 249 * For the rest rules look so: 250 * 251 * It's OK to put directory into a group unless 252 * it has too many directories already (max_dirs) or 253 * it has too few free inodes left (min_inodes) or 254 * it has too few free blocks left (min_blocks) or 255 * it's already running too large debt (max_debt). 256 * Parent's group is prefered, if it doesn't satisfy these 257 * conditions we search cyclically through the rest. If none 258 * of the groups look good we just look for a group with more 259 * free inodes than average (starting at parent's group). 260 * 261 * Debt is incremented each time we allocate a directory and decremented 262 * when we allocate an inode, within 0--255. 263 */ 264 265 #define INODE_COST 64 266 #define BLOCK_COST 256 267 268 static int find_group_orlov(struct super_block *sb, struct inode *parent) 269 { 270 int parent_group = EXT2_I(parent)->i_block_group; 271 struct ext2_sb_info *sbi = EXT2_SB(sb); 272 struct ext2_super_block *es = sbi->s_es; 273 int ngroups = sbi->s_groups_count; 274 int inodes_per_group = EXT2_INODES_PER_GROUP(sb); 275 int freei; 276 int avefreei; 277 int free_blocks; 278 int avefreeb; 279 int blocks_per_dir; 280 int ndirs; 281 int max_debt, max_dirs, min_blocks, min_inodes; 282 int group = -1, i; 283 struct ext2_group_desc *desc; 284 285 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter); 286 avefreei = freei / ngroups; 287 free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); 288 avefreeb = free_blocks / ngroups; 289 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter); 290 291 if ((parent == sb->s_root->d_inode) || 292 (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) { 293 struct ext2_group_desc *best_desc = NULL; 294 int best_ndir = inodes_per_group; 295 int best_group = -1; 296 297 get_random_bytes(&group, sizeof(group)); 298 parent_group = (unsigned)group % ngroups; 299 for (i = 0; i < ngroups; i++) { 300 group = (parent_group + i) % ngroups; 301 desc = ext2_get_group_desc (sb, group, NULL); 302 if (!desc || !desc->bg_free_inodes_count) 303 continue; 304 if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir) 305 continue; 306 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei) 307 continue; 308 if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb) 309 continue; 310 best_group = group; 311 best_ndir = le16_to_cpu(desc->bg_used_dirs_count); 312 best_desc = desc; 313 } 314 if (best_group >= 0) { 315 desc = best_desc; 316 group = best_group; 317 goto found; 318 } 319 goto fallback; 320 } 321 322 if (ndirs == 0) 323 ndirs = 1; /* percpu_counters are approximate... */ 324 325 blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs; 326 327 max_dirs = ndirs / ngroups + inodes_per_group / 16; 328 min_inodes = avefreei - inodes_per_group / 4; 329 min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4; 330 331 max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST); 332 if (max_debt * INODE_COST > inodes_per_group) 333 max_debt = inodes_per_group / INODE_COST; 334 if (max_debt > 255) 335 max_debt = 255; 336 if (max_debt == 0) 337 max_debt = 1; 338 339 for (i = 0; i < ngroups; i++) { 340 group = (parent_group + i) % ngroups; 341 desc = ext2_get_group_desc (sb, group, NULL); 342 if (!desc || !desc->bg_free_inodes_count) 343 continue; 344 if (sbi->s_debts[group] >= max_debt) 345 continue; 346 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs) 347 continue; 348 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes) 349 continue; 350 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks) 351 continue; 352 goto found; 353 } 354 355 fallback: 356 for (i = 0; i < ngroups; i++) { 357 group = (parent_group + i) % ngroups; 358 desc = ext2_get_group_desc (sb, group, NULL); 359 if (!desc || !desc->bg_free_inodes_count) 360 continue; 361 if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei) 362 goto found; 363 } 364 365 if (avefreei) { 366 /* 367 * The free-inodes counter is approximate, and for really small 368 * filesystems the above test can fail to find any blockgroups 369 */ 370 avefreei = 0; 371 goto fallback; 372 } 373 374 return -1; 375 376 found: 377 return group; 378 } 379 380 static int find_group_other(struct super_block *sb, struct inode *parent) 381 { 382 int parent_group = EXT2_I(parent)->i_block_group; 383 int ngroups = EXT2_SB(sb)->s_groups_count; 384 struct ext2_group_desc *desc; 385 int group, i; 386 387 /* 388 * Try to place the inode in its parent directory 389 */ 390 group = parent_group; 391 desc = ext2_get_group_desc (sb, group, NULL); 392 if (desc && le16_to_cpu(desc->bg_free_inodes_count) && 393 le16_to_cpu(desc->bg_free_blocks_count)) 394 goto found; 395 396 /* 397 * We're going to place this inode in a different blockgroup from its 398 * parent. We want to cause files in a common directory to all land in 399 * the same blockgroup. But we want files which are in a different 400 * directory which shares a blockgroup with our parent to land in a 401 * different blockgroup. 402 * 403 * So add our directory's i_ino into the starting point for the hash. 404 */ 405 group = (group + parent->i_ino) % ngroups; 406 407 /* 408 * Use a quadratic hash to find a group with a free inode and some 409 * free blocks. 410 */ 411 for (i = 1; i < ngroups; i <<= 1) { 412 group += i; 413 if (group >= ngroups) 414 group -= ngroups; 415 desc = ext2_get_group_desc (sb, group, NULL); 416 if (desc && le16_to_cpu(desc->bg_free_inodes_count) && 417 le16_to_cpu(desc->bg_free_blocks_count)) 418 goto found; 419 } 420 421 /* 422 * That failed: try linear search for a free inode, even if that group 423 * has no free blocks. 424 */ 425 group = parent_group; 426 for (i = 0; i < ngroups; i++) { 427 if (++group >= ngroups) 428 group = 0; 429 desc = ext2_get_group_desc (sb, group, NULL); 430 if (desc && le16_to_cpu(desc->bg_free_inodes_count)) 431 goto found; 432 } 433 434 return -1; 435 436 found: 437 return group; 438 } 439 440 struct inode *ext2_new_inode(struct inode *dir, int mode) 441 { 442 struct super_block *sb; 443 struct buffer_head *bitmap_bh = NULL; 444 struct buffer_head *bh2; 445 int group, i; 446 ino_t ino = 0; 447 struct inode * inode; 448 struct ext2_group_desc *gdp; 449 struct ext2_super_block *es; 450 struct ext2_inode_info *ei; 451 struct ext2_sb_info *sbi; 452 int err; 453 454 sb = dir->i_sb; 455 inode = new_inode(sb); 456 if (!inode) 457 return ERR_PTR(-ENOMEM); 458 459 ei = EXT2_I(inode); 460 sbi = EXT2_SB(sb); 461 es = sbi->s_es; 462 if (S_ISDIR(mode)) { 463 if (test_opt(sb, OLDALLOC)) 464 group = find_group_dir(sb, dir); 465 else 466 group = find_group_orlov(sb, dir); 467 } else 468 group = find_group_other(sb, dir); 469 470 if (group == -1) { 471 err = -ENOSPC; 472 goto fail; 473 } 474 475 for (i = 0; i < sbi->s_groups_count; i++) { 476 gdp = ext2_get_group_desc(sb, group, &bh2); 477 brelse(bitmap_bh); 478 bitmap_bh = read_inode_bitmap(sb, group); 479 if (!bitmap_bh) { 480 err = -EIO; 481 goto fail; 482 } 483 ino = 0; 484 485 repeat_in_this_group: 486 ino = ext2_find_next_zero_bit((unsigned long *)bitmap_bh->b_data, 487 EXT2_INODES_PER_GROUP(sb), ino); 488 if (ino >= EXT2_INODES_PER_GROUP(sb)) { 489 /* 490 * Rare race: find_group_xx() decided that there were 491 * free inodes in this group, but by the time we tried 492 * to allocate one, they're all gone. This can also 493 * occur because the counters which find_group_orlov() 494 * uses are approximate. So just go and search the 495 * next block group. 496 */ 497 if (++group == sbi->s_groups_count) 498 group = 0; 499 continue; 500 } 501 if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group), 502 ino, bitmap_bh->b_data)) { 503 /* we lost this inode */ 504 if (++ino >= EXT2_INODES_PER_GROUP(sb)) { 505 /* this group is exhausted, try next group */ 506 if (++group == sbi->s_groups_count) 507 group = 0; 508 continue; 509 } 510 /* try to find free inode in the same group */ 511 goto repeat_in_this_group; 512 } 513 goto got; 514 } 515 516 /* 517 * Scanned all blockgroups. 518 */ 519 err = -ENOSPC; 520 goto fail; 521 got: 522 mark_buffer_dirty(bitmap_bh); 523 if (sb->s_flags & MS_SYNCHRONOUS) 524 sync_dirty_buffer(bitmap_bh); 525 brelse(bitmap_bh); 526 527 ino += group * EXT2_INODES_PER_GROUP(sb) + 1; 528 if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { 529 ext2_error (sb, "ext2_new_inode", 530 "reserved inode or inode > inodes count - " 531 "block_group = %d,inode=%lu", group, 532 (unsigned long) ino); 533 err = -EIO; 534 goto fail; 535 } 536 537 percpu_counter_add(&sbi->s_freeinodes_counter, -1); 538 if (S_ISDIR(mode)) 539 percpu_counter_inc(&sbi->s_dirs_counter); 540 541 spin_lock(sb_bgl_lock(sbi, group)); 542 gdp->bg_free_inodes_count = 543 cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1); 544 if (S_ISDIR(mode)) { 545 if (sbi->s_debts[group] < 255) 546 sbi->s_debts[group]++; 547 gdp->bg_used_dirs_count = 548 cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1); 549 } else { 550 if (sbi->s_debts[group]) 551 sbi->s_debts[group]--; 552 } 553 spin_unlock(sb_bgl_lock(sbi, group)); 554 555 sb->s_dirt = 1; 556 mark_buffer_dirty(bh2); 557 inode->i_uid = current->fsuid; 558 if (test_opt (sb, GRPID)) 559 inode->i_gid = dir->i_gid; 560 else if (dir->i_mode & S_ISGID) { 561 inode->i_gid = dir->i_gid; 562 if (S_ISDIR(mode)) 563 mode |= S_ISGID; 564 } else 565 inode->i_gid = current->fsgid; 566 inode->i_mode = mode; 567 568 inode->i_ino = ino; 569 inode->i_blocks = 0; 570 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; 571 memset(ei->i_data, 0, sizeof(ei->i_data)); 572 ei->i_flags = EXT2_I(dir)->i_flags & ~EXT2_BTREE_FL; 573 if (S_ISLNK(mode)) 574 ei->i_flags &= ~(EXT2_IMMUTABLE_FL|EXT2_APPEND_FL); 575 /* dirsync is only applied to directories */ 576 if (!S_ISDIR(mode)) 577 ei->i_flags &= ~EXT2_DIRSYNC_FL; 578 ei->i_faddr = 0; 579 ei->i_frag_no = 0; 580 ei->i_frag_size = 0; 581 ei->i_file_acl = 0; 582 ei->i_dir_acl = 0; 583 ei->i_dtime = 0; 584 ei->i_block_alloc_info = NULL; 585 ei->i_block_group = group; 586 ei->i_dir_start_lookup = 0; 587 ei->i_state = EXT2_STATE_NEW; 588 ext2_set_inode_flags(inode); 589 spin_lock(&sbi->s_next_gen_lock); 590 inode->i_generation = sbi->s_next_generation++; 591 spin_unlock(&sbi->s_next_gen_lock); 592 insert_inode_hash(inode); 593 594 if (DQUOT_ALLOC_INODE(inode)) { 595 err = -EDQUOT; 596 goto fail_drop; 597 } 598 599 err = ext2_init_acl(inode, dir); 600 if (err) 601 goto fail_free_drop; 602 603 err = ext2_init_security(inode,dir); 604 if (err) 605 goto fail_free_drop; 606 607 mark_inode_dirty(inode); 608 ext2_debug("allocating inode %lu\n", inode->i_ino); 609 ext2_preread_inode(inode); 610 return inode; 611 612 fail_free_drop: 613 DQUOT_FREE_INODE(inode); 614 615 fail_drop: 616 DQUOT_DROP(inode); 617 inode->i_flags |= S_NOQUOTA; 618 inode->i_nlink = 0; 619 iput(inode); 620 return ERR_PTR(err); 621 622 fail: 623 make_bad_inode(inode); 624 iput(inode); 625 return ERR_PTR(err); 626 } 627 628 unsigned long ext2_count_free_inodes (struct super_block * sb) 629 { 630 struct ext2_group_desc *desc; 631 unsigned long desc_count = 0; 632 int i; 633 634 #ifdef EXT2FS_DEBUG 635 struct ext2_super_block *es; 636 unsigned long bitmap_count = 0; 637 struct buffer_head *bitmap_bh = NULL; 638 639 es = EXT2_SB(sb)->s_es; 640 for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { 641 unsigned x; 642 643 desc = ext2_get_group_desc (sb, i, NULL); 644 if (!desc) 645 continue; 646 desc_count += le16_to_cpu(desc->bg_free_inodes_count); 647 brelse(bitmap_bh); 648 bitmap_bh = read_inode_bitmap(sb, i); 649 if (!bitmap_bh) 650 continue; 651 652 x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8); 653 printk("group %d: stored = %d, counted = %u\n", 654 i, le16_to_cpu(desc->bg_free_inodes_count), x); 655 bitmap_count += x; 656 } 657 brelse(bitmap_bh); 658 printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n", 659 percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter), 660 desc_count, bitmap_count); 661 return desc_count; 662 #else 663 for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { 664 desc = ext2_get_group_desc (sb, i, NULL); 665 if (!desc) 666 continue; 667 desc_count += le16_to_cpu(desc->bg_free_inodes_count); 668 } 669 return desc_count; 670 #endif 671 } 672 673 /* Called at mount-time, super-block is locked */ 674 unsigned long ext2_count_dirs (struct super_block * sb) 675 { 676 unsigned long count = 0; 677 int i; 678 679 for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { 680 struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL); 681 if (!gdp) 682 continue; 683 count += le16_to_cpu(gdp->bg_used_dirs_count); 684 } 685 return count; 686 } 687 688