1 /* 2 * linux/fs/ext4/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@redhat.com), 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/time.h> 16 #include <linux/fs.h> 17 #include <linux/stat.h> 18 #include <linux/string.h> 19 #include <linux/quotaops.h> 20 #include <linux/buffer_head.h> 21 #include <linux/random.h> 22 #include <linux/bitops.h> 23 #include <linux/blkdev.h> 24 #include <asm/byteorder.h> 25 26 #include "ext4.h" 27 #include "ext4_jbd2.h" 28 #include "xattr.h" 29 #include "acl.h" 30 31 #include <trace/events/ext4.h> 32 33 /* 34 * ialloc.c contains the inodes allocation and deallocation routines 35 */ 36 37 /* 38 * The free inodes are managed by bitmaps. A file system contains several 39 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap 40 * block for inodes, N blocks for the inode table and data blocks. 41 * 42 * The file system contains group descriptors which are located after the 43 * super block. Each descriptor contains the number of the bitmap block and 44 * the free blocks count in the block. 45 */ 46 47 /* 48 * To avoid calling the atomic setbit hundreds or thousands of times, we only 49 * need to use it within a single byte (to ensure we get endianness right). 50 * We can use memset for the rest of the bitmap as there are no other users. 51 */ 52 void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap) 53 { 54 int i; 55 56 if (start_bit >= end_bit) 57 return; 58 59 ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit); 60 for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++) 61 ext4_set_bit(i, bitmap); 62 if (i < end_bit) 63 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3); 64 } 65 66 /* Initializes an uninitialized inode bitmap */ 67 static int ext4_init_inode_bitmap(struct super_block *sb, 68 struct buffer_head *bh, 69 ext4_group_t block_group, 70 struct ext4_group_desc *gdp) 71 { 72 struct ext4_group_info *grp; 73 struct ext4_sb_info *sbi = EXT4_SB(sb); 74 J_ASSERT_BH(bh, buffer_locked(bh)); 75 76 /* If checksum is bad mark all blocks and inodes use to prevent 77 * allocation, essentially implementing a per-group read-only flag. */ 78 if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { 79 ext4_error(sb, "Checksum bad for group %u", block_group); 80 grp = ext4_get_group_info(sb, block_group); 81 if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) 82 percpu_counter_sub(&sbi->s_freeclusters_counter, 83 grp->bb_free); 84 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state); 85 if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { 86 int count; 87 count = ext4_free_inodes_count(sb, gdp); 88 percpu_counter_sub(&sbi->s_freeinodes_counter, 89 count); 90 } 91 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state); 92 return -EFSBADCRC; 93 } 94 95 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8); 96 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8, 97 bh->b_data); 98 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh, 99 EXT4_INODES_PER_GROUP(sb) / 8); 100 ext4_group_desc_csum_set(sb, block_group, gdp); 101 102 return 0; 103 } 104 105 void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate) 106 { 107 if (uptodate) { 108 set_buffer_uptodate(bh); 109 set_bitmap_uptodate(bh); 110 } 111 unlock_buffer(bh); 112 put_bh(bh); 113 } 114 115 static int ext4_validate_inode_bitmap(struct super_block *sb, 116 struct ext4_group_desc *desc, 117 ext4_group_t block_group, 118 struct buffer_head *bh) 119 { 120 ext4_fsblk_t blk; 121 struct ext4_group_info *grp = ext4_get_group_info(sb, block_group); 122 struct ext4_sb_info *sbi = EXT4_SB(sb); 123 124 if (buffer_verified(bh)) 125 return 0; 126 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) 127 return -EFSCORRUPTED; 128 129 ext4_lock_group(sb, block_group); 130 blk = ext4_inode_bitmap(sb, desc); 131 if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh, 132 EXT4_INODES_PER_GROUP(sb) / 8)) { 133 ext4_unlock_group(sb, block_group); 134 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, " 135 "inode_bitmap = %llu", block_group, blk); 136 grp = ext4_get_group_info(sb, block_group); 137 if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { 138 int count; 139 count = ext4_free_inodes_count(sb, desc); 140 percpu_counter_sub(&sbi->s_freeinodes_counter, 141 count); 142 } 143 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state); 144 return -EFSBADCRC; 145 } 146 set_buffer_verified(bh); 147 ext4_unlock_group(sb, block_group); 148 return 0; 149 } 150 151 /* 152 * Read the inode allocation bitmap for a given block_group, reading 153 * into the specified slot in the superblock's bitmap cache. 154 * 155 * Return buffer_head of bitmap on success or NULL. 156 */ 157 static struct buffer_head * 158 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) 159 { 160 struct ext4_group_desc *desc; 161 struct buffer_head *bh = NULL; 162 ext4_fsblk_t bitmap_blk; 163 int err; 164 165 desc = ext4_get_group_desc(sb, block_group, NULL); 166 if (!desc) 167 return ERR_PTR(-EFSCORRUPTED); 168 169 bitmap_blk = ext4_inode_bitmap(sb, desc); 170 bh = sb_getblk(sb, bitmap_blk); 171 if (unlikely(!bh)) { 172 ext4_error(sb, "Cannot read inode bitmap - " 173 "block_group = %u, inode_bitmap = %llu", 174 block_group, bitmap_blk); 175 return ERR_PTR(-EIO); 176 } 177 if (bitmap_uptodate(bh)) 178 goto verify; 179 180 lock_buffer(bh); 181 if (bitmap_uptodate(bh)) { 182 unlock_buffer(bh); 183 goto verify; 184 } 185 186 ext4_lock_group(sb, block_group); 187 if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { 188 err = ext4_init_inode_bitmap(sb, bh, block_group, desc); 189 set_bitmap_uptodate(bh); 190 set_buffer_uptodate(bh); 191 set_buffer_verified(bh); 192 ext4_unlock_group(sb, block_group); 193 unlock_buffer(bh); 194 if (err) 195 goto out; 196 return bh; 197 } 198 ext4_unlock_group(sb, block_group); 199 200 if (buffer_uptodate(bh)) { 201 /* 202 * if not uninit if bh is uptodate, 203 * bitmap is also uptodate 204 */ 205 set_bitmap_uptodate(bh); 206 unlock_buffer(bh); 207 goto verify; 208 } 209 /* 210 * submit the buffer_head for reading 211 */ 212 trace_ext4_load_inode_bitmap(sb, block_group); 213 bh->b_end_io = ext4_end_bitmap_read; 214 get_bh(bh); 215 submit_bh(READ | REQ_META | REQ_PRIO, bh); 216 wait_on_buffer(bh); 217 if (!buffer_uptodate(bh)) { 218 put_bh(bh); 219 ext4_error(sb, "Cannot read inode bitmap - " 220 "block_group = %u, inode_bitmap = %llu", 221 block_group, bitmap_blk); 222 return ERR_PTR(-EIO); 223 } 224 225 verify: 226 err = ext4_validate_inode_bitmap(sb, desc, block_group, bh); 227 if (err) 228 goto out; 229 return bh; 230 out: 231 put_bh(bh); 232 return ERR_PTR(err); 233 } 234 235 /* 236 * NOTE! When we get the inode, we're the only people 237 * that have access to it, and as such there are no 238 * race conditions we have to worry about. The inode 239 * is not on the hash-lists, and it cannot be reached 240 * through the filesystem because the directory entry 241 * has been deleted earlier. 242 * 243 * HOWEVER: we must make sure that we get no aliases, 244 * which means that we have to call "clear_inode()" 245 * _before_ we mark the inode not in use in the inode 246 * bitmaps. Otherwise a newly created file might use 247 * the same inode number (not actually the same pointer 248 * though), and then we'd have two inodes sharing the 249 * same inode number and space on the harddisk. 250 */ 251 void ext4_free_inode(handle_t *handle, struct inode *inode) 252 { 253 struct super_block *sb = inode->i_sb; 254 int is_directory; 255 unsigned long ino; 256 struct buffer_head *bitmap_bh = NULL; 257 struct buffer_head *bh2; 258 ext4_group_t block_group; 259 unsigned long bit; 260 struct ext4_group_desc *gdp; 261 struct ext4_super_block *es; 262 struct ext4_sb_info *sbi; 263 int fatal = 0, err, count, cleared; 264 struct ext4_group_info *grp; 265 266 if (!sb) { 267 printk(KERN_ERR "EXT4-fs: %s:%d: inode on " 268 "nonexistent device\n", __func__, __LINE__); 269 return; 270 } 271 if (atomic_read(&inode->i_count) > 1) { 272 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d", 273 __func__, __LINE__, inode->i_ino, 274 atomic_read(&inode->i_count)); 275 return; 276 } 277 if (inode->i_nlink) { 278 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n", 279 __func__, __LINE__, inode->i_ino, inode->i_nlink); 280 return; 281 } 282 sbi = EXT4_SB(sb); 283 284 ino = inode->i_ino; 285 ext4_debug("freeing inode %lu\n", ino); 286 trace_ext4_free_inode(inode); 287 288 /* 289 * Note: we must free any quota before locking the superblock, 290 * as writing the quota to disk may need the lock as well. 291 */ 292 dquot_initialize(inode); 293 ext4_xattr_delete_inode(handle, inode); 294 dquot_free_inode(inode); 295 dquot_drop(inode); 296 297 is_directory = S_ISDIR(inode->i_mode); 298 299 /* Do this BEFORE marking the inode not in use or returning an error */ 300 ext4_clear_inode(inode); 301 302 es = EXT4_SB(sb)->s_es; 303 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { 304 ext4_error(sb, "reserved or nonexistent inode %lu", ino); 305 goto error_return; 306 } 307 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb); 308 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb); 309 bitmap_bh = ext4_read_inode_bitmap(sb, block_group); 310 /* Don't bother if the inode bitmap is corrupt. */ 311 grp = ext4_get_group_info(sb, block_group); 312 if (IS_ERR(bitmap_bh)) { 313 fatal = PTR_ERR(bitmap_bh); 314 bitmap_bh = NULL; 315 goto error_return; 316 } 317 if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) { 318 fatal = -EFSCORRUPTED; 319 goto error_return; 320 } 321 322 BUFFER_TRACE(bitmap_bh, "get_write_access"); 323 fatal = ext4_journal_get_write_access(handle, bitmap_bh); 324 if (fatal) 325 goto error_return; 326 327 fatal = -ESRCH; 328 gdp = ext4_get_group_desc(sb, block_group, &bh2); 329 if (gdp) { 330 BUFFER_TRACE(bh2, "get_write_access"); 331 fatal = ext4_journal_get_write_access(handle, bh2); 332 } 333 ext4_lock_group(sb, block_group); 334 cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data); 335 if (fatal || !cleared) { 336 ext4_unlock_group(sb, block_group); 337 goto out; 338 } 339 340 count = ext4_free_inodes_count(sb, gdp) + 1; 341 ext4_free_inodes_set(sb, gdp, count); 342 if (is_directory) { 343 count = ext4_used_dirs_count(sb, gdp) - 1; 344 ext4_used_dirs_set(sb, gdp, count); 345 percpu_counter_dec(&sbi->s_dirs_counter); 346 } 347 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh, 348 EXT4_INODES_PER_GROUP(sb) / 8); 349 ext4_group_desc_csum_set(sb, block_group, gdp); 350 ext4_unlock_group(sb, block_group); 351 352 percpu_counter_inc(&sbi->s_freeinodes_counter); 353 if (sbi->s_log_groups_per_flex) { 354 ext4_group_t f = ext4_flex_group(sbi, block_group); 355 356 atomic_inc(&sbi->s_flex_groups[f].free_inodes); 357 if (is_directory) 358 atomic_dec(&sbi->s_flex_groups[f].used_dirs); 359 } 360 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata"); 361 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2); 362 out: 363 if (cleared) { 364 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata"); 365 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); 366 if (!fatal) 367 fatal = err; 368 } else { 369 ext4_error(sb, "bit already cleared for inode %lu", ino); 370 if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { 371 int count; 372 count = ext4_free_inodes_count(sb, gdp); 373 percpu_counter_sub(&sbi->s_freeinodes_counter, 374 count); 375 } 376 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state); 377 } 378 379 error_return: 380 brelse(bitmap_bh); 381 ext4_std_error(sb, fatal); 382 } 383 384 struct orlov_stats { 385 __u64 free_clusters; 386 __u32 free_inodes; 387 __u32 used_dirs; 388 }; 389 390 /* 391 * Helper function for Orlov's allocator; returns critical information 392 * for a particular block group or flex_bg. If flex_size is 1, then g 393 * is a block group number; otherwise it is flex_bg number. 394 */ 395 static void get_orlov_stats(struct super_block *sb, ext4_group_t g, 396 int flex_size, struct orlov_stats *stats) 397 { 398 struct ext4_group_desc *desc; 399 struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups; 400 401 if (flex_size > 1) { 402 stats->free_inodes = atomic_read(&flex_group[g].free_inodes); 403 stats->free_clusters = atomic64_read(&flex_group[g].free_clusters); 404 stats->used_dirs = atomic_read(&flex_group[g].used_dirs); 405 return; 406 } 407 408 desc = ext4_get_group_desc(sb, g, NULL); 409 if (desc) { 410 stats->free_inodes = ext4_free_inodes_count(sb, desc); 411 stats->free_clusters = ext4_free_group_clusters(sb, desc); 412 stats->used_dirs = ext4_used_dirs_count(sb, desc); 413 } else { 414 stats->free_inodes = 0; 415 stats->free_clusters = 0; 416 stats->used_dirs = 0; 417 } 418 } 419 420 /* 421 * Orlov's allocator for directories. 422 * 423 * We always try to spread first-level directories. 424 * 425 * If there are blockgroups with both free inodes and free blocks counts 426 * not worse than average we return one with smallest directory count. 427 * Otherwise we simply return a random group. 428 * 429 * For the rest rules look so: 430 * 431 * It's OK to put directory into a group unless 432 * it has too many directories already (max_dirs) or 433 * it has too few free inodes left (min_inodes) or 434 * it has too few free blocks left (min_blocks) or 435 * Parent's group is preferred, if it doesn't satisfy these 436 * conditions we search cyclically through the rest. If none 437 * of the groups look good we just look for a group with more 438 * free inodes than average (starting at parent's group). 439 */ 440 441 static int find_group_orlov(struct super_block *sb, struct inode *parent, 442 ext4_group_t *group, umode_t mode, 443 const struct qstr *qstr) 444 { 445 ext4_group_t parent_group = EXT4_I(parent)->i_block_group; 446 struct ext4_sb_info *sbi = EXT4_SB(sb); 447 ext4_group_t real_ngroups = ext4_get_groups_count(sb); 448 int inodes_per_group = EXT4_INODES_PER_GROUP(sb); 449 unsigned int freei, avefreei, grp_free; 450 ext4_fsblk_t freeb, avefreec; 451 unsigned int ndirs; 452 int max_dirs, min_inodes; 453 ext4_grpblk_t min_clusters; 454 ext4_group_t i, grp, g, ngroups; 455 struct ext4_group_desc *desc; 456 struct orlov_stats stats; 457 int flex_size = ext4_flex_bg_size(sbi); 458 struct dx_hash_info hinfo; 459 460 ngroups = real_ngroups; 461 if (flex_size > 1) { 462 ngroups = (real_ngroups + flex_size - 1) >> 463 sbi->s_log_groups_per_flex; 464 parent_group >>= sbi->s_log_groups_per_flex; 465 } 466 467 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter); 468 avefreei = freei / ngroups; 469 freeb = EXT4_C2B(sbi, 470 percpu_counter_read_positive(&sbi->s_freeclusters_counter)); 471 avefreec = freeb; 472 do_div(avefreec, ngroups); 473 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter); 474 475 if (S_ISDIR(mode) && 476 ((parent == d_inode(sb->s_root)) || 477 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) { 478 int best_ndir = inodes_per_group; 479 int ret = -1; 480 481 if (qstr) { 482 hinfo.hash_version = DX_HASH_HALF_MD4; 483 hinfo.seed = sbi->s_hash_seed; 484 ext4fs_dirhash(qstr->name, qstr->len, &hinfo); 485 grp = hinfo.hash; 486 } else 487 grp = prandom_u32(); 488 parent_group = (unsigned)grp % ngroups; 489 for (i = 0; i < ngroups; i++) { 490 g = (parent_group + i) % ngroups; 491 get_orlov_stats(sb, g, flex_size, &stats); 492 if (!stats.free_inodes) 493 continue; 494 if (stats.used_dirs >= best_ndir) 495 continue; 496 if (stats.free_inodes < avefreei) 497 continue; 498 if (stats.free_clusters < avefreec) 499 continue; 500 grp = g; 501 ret = 0; 502 best_ndir = stats.used_dirs; 503 } 504 if (ret) 505 goto fallback; 506 found_flex_bg: 507 if (flex_size == 1) { 508 *group = grp; 509 return 0; 510 } 511 512 /* 513 * We pack inodes at the beginning of the flexgroup's 514 * inode tables. Block allocation decisions will do 515 * something similar, although regular files will 516 * start at 2nd block group of the flexgroup. See 517 * ext4_ext_find_goal() and ext4_find_near(). 518 */ 519 grp *= flex_size; 520 for (i = 0; i < flex_size; i++) { 521 if (grp+i >= real_ngroups) 522 break; 523 desc = ext4_get_group_desc(sb, grp+i, NULL); 524 if (desc && ext4_free_inodes_count(sb, desc)) { 525 *group = grp+i; 526 return 0; 527 } 528 } 529 goto fallback; 530 } 531 532 max_dirs = ndirs / ngroups + inodes_per_group / 16; 533 min_inodes = avefreei - inodes_per_group*flex_size / 4; 534 if (min_inodes < 1) 535 min_inodes = 1; 536 min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4; 537 538 /* 539 * Start looking in the flex group where we last allocated an 540 * inode for this parent directory 541 */ 542 if (EXT4_I(parent)->i_last_alloc_group != ~0) { 543 parent_group = EXT4_I(parent)->i_last_alloc_group; 544 if (flex_size > 1) 545 parent_group >>= sbi->s_log_groups_per_flex; 546 } 547 548 for (i = 0; i < ngroups; i++) { 549 grp = (parent_group + i) % ngroups; 550 get_orlov_stats(sb, grp, flex_size, &stats); 551 if (stats.used_dirs >= max_dirs) 552 continue; 553 if (stats.free_inodes < min_inodes) 554 continue; 555 if (stats.free_clusters < min_clusters) 556 continue; 557 goto found_flex_bg; 558 } 559 560 fallback: 561 ngroups = real_ngroups; 562 avefreei = freei / ngroups; 563 fallback_retry: 564 parent_group = EXT4_I(parent)->i_block_group; 565 for (i = 0; i < ngroups; i++) { 566 grp = (parent_group + i) % ngroups; 567 desc = ext4_get_group_desc(sb, grp, NULL); 568 if (desc) { 569 grp_free = ext4_free_inodes_count(sb, desc); 570 if (grp_free && grp_free >= avefreei) { 571 *group = grp; 572 return 0; 573 } 574 } 575 } 576 577 if (avefreei) { 578 /* 579 * The free-inodes counter is approximate, and for really small 580 * filesystems the above test can fail to find any blockgroups 581 */ 582 avefreei = 0; 583 goto fallback_retry; 584 } 585 586 return -1; 587 } 588 589 static int find_group_other(struct super_block *sb, struct inode *parent, 590 ext4_group_t *group, umode_t mode) 591 { 592 ext4_group_t parent_group = EXT4_I(parent)->i_block_group; 593 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb); 594 struct ext4_group_desc *desc; 595 int flex_size = ext4_flex_bg_size(EXT4_SB(sb)); 596 597 /* 598 * Try to place the inode is the same flex group as its 599 * parent. If we can't find space, use the Orlov algorithm to 600 * find another flex group, and store that information in the 601 * parent directory's inode information so that use that flex 602 * group for future allocations. 603 */ 604 if (flex_size > 1) { 605 int retry = 0; 606 607 try_again: 608 parent_group &= ~(flex_size-1); 609 last = parent_group + flex_size; 610 if (last > ngroups) 611 last = ngroups; 612 for (i = parent_group; i < last; i++) { 613 desc = ext4_get_group_desc(sb, i, NULL); 614 if (desc && ext4_free_inodes_count(sb, desc)) { 615 *group = i; 616 return 0; 617 } 618 } 619 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) { 620 retry = 1; 621 parent_group = EXT4_I(parent)->i_last_alloc_group; 622 goto try_again; 623 } 624 /* 625 * If this didn't work, use the Orlov search algorithm 626 * to find a new flex group; we pass in the mode to 627 * avoid the topdir algorithms. 628 */ 629 *group = parent_group + flex_size; 630 if (*group > ngroups) 631 *group = 0; 632 return find_group_orlov(sb, parent, group, mode, NULL); 633 } 634 635 /* 636 * Try to place the inode in its parent directory 637 */ 638 *group = parent_group; 639 desc = ext4_get_group_desc(sb, *group, NULL); 640 if (desc && ext4_free_inodes_count(sb, desc) && 641 ext4_free_group_clusters(sb, desc)) 642 return 0; 643 644 /* 645 * We're going to place this inode in a different blockgroup from its 646 * parent. We want to cause files in a common directory to all land in 647 * the same blockgroup. But we want files which are in a different 648 * directory which shares a blockgroup with our parent to land in a 649 * different blockgroup. 650 * 651 * So add our directory's i_ino into the starting point for the hash. 652 */ 653 *group = (*group + parent->i_ino) % ngroups; 654 655 /* 656 * Use a quadratic hash to find a group with a free inode and some free 657 * blocks. 658 */ 659 for (i = 1; i < ngroups; i <<= 1) { 660 *group += i; 661 if (*group >= ngroups) 662 *group -= ngroups; 663 desc = ext4_get_group_desc(sb, *group, NULL); 664 if (desc && ext4_free_inodes_count(sb, desc) && 665 ext4_free_group_clusters(sb, desc)) 666 return 0; 667 } 668 669 /* 670 * That failed: try linear search for a free inode, even if that group 671 * has no free blocks. 672 */ 673 *group = parent_group; 674 for (i = 0; i < ngroups; i++) { 675 if (++*group >= ngroups) 676 *group = 0; 677 desc = ext4_get_group_desc(sb, *group, NULL); 678 if (desc && ext4_free_inodes_count(sb, desc)) 679 return 0; 680 } 681 682 return -1; 683 } 684 685 /* 686 * In no journal mode, if an inode has recently been deleted, we want 687 * to avoid reusing it until we're reasonably sure the inode table 688 * block has been written back to disk. (Yes, these values are 689 * somewhat arbitrary...) 690 */ 691 #define RECENTCY_MIN 5 692 #define RECENTCY_DIRTY 30 693 694 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino) 695 { 696 struct ext4_group_desc *gdp; 697 struct ext4_inode *raw_inode; 698 struct buffer_head *bh; 699 unsigned long dtime, now; 700 int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block; 701 int offset, ret = 0, recentcy = RECENTCY_MIN; 702 703 gdp = ext4_get_group_desc(sb, group, NULL); 704 if (unlikely(!gdp)) 705 return 0; 706 707 bh = sb_getblk(sb, ext4_inode_table(sb, gdp) + 708 (ino / inodes_per_block)); 709 if (unlikely(!bh) || !buffer_uptodate(bh)) 710 /* 711 * If the block is not in the buffer cache, then it 712 * must have been written out. 713 */ 714 goto out; 715 716 offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb); 717 raw_inode = (struct ext4_inode *) (bh->b_data + offset); 718 dtime = le32_to_cpu(raw_inode->i_dtime); 719 now = get_seconds(); 720 if (buffer_dirty(bh)) 721 recentcy += RECENTCY_DIRTY; 722 723 if (dtime && (dtime < now) && (now < dtime + recentcy)) 724 ret = 1; 725 out: 726 brelse(bh); 727 return ret; 728 } 729 730 /* 731 * There are two policies for allocating an inode. If the new inode is 732 * a directory, then a forward search is made for a block group with both 733 * free space and a low directory-to-inode ratio; if that fails, then of 734 * the groups with above-average free space, that group with the fewest 735 * directories already is chosen. 736 * 737 * For other inodes, search forward from the parent directory's block 738 * group to find a free inode. 739 */ 740 struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir, 741 umode_t mode, const struct qstr *qstr, 742 __u32 goal, uid_t *owner, int handle_type, 743 unsigned int line_no, int nblocks) 744 { 745 struct super_block *sb; 746 struct buffer_head *inode_bitmap_bh = NULL; 747 struct buffer_head *group_desc_bh; 748 ext4_group_t ngroups, group = 0; 749 unsigned long ino = 0; 750 struct inode *inode; 751 struct ext4_group_desc *gdp = NULL; 752 struct ext4_inode_info *ei; 753 struct ext4_sb_info *sbi; 754 int ret2, err; 755 struct inode *ret; 756 ext4_group_t i; 757 ext4_group_t flex_group; 758 struct ext4_group_info *grp; 759 int encrypt = 0; 760 761 /* Cannot create files in a deleted directory */ 762 if (!dir || !dir->i_nlink) 763 return ERR_PTR(-EPERM); 764 765 if ((ext4_encrypted_inode(dir) || 766 DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) && 767 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { 768 err = ext4_get_encryption_info(dir); 769 if (err) 770 return ERR_PTR(err); 771 if (ext4_encryption_info(dir) == NULL) 772 return ERR_PTR(-EPERM); 773 if (!handle) 774 nblocks += EXT4_DATA_TRANS_BLOCKS(dir->i_sb); 775 encrypt = 1; 776 } 777 778 sb = dir->i_sb; 779 ngroups = ext4_get_groups_count(sb); 780 trace_ext4_request_inode(dir, mode); 781 inode = new_inode(sb); 782 if (!inode) 783 return ERR_PTR(-ENOMEM); 784 ei = EXT4_I(inode); 785 sbi = EXT4_SB(sb); 786 787 /* 788 * Initalize owners and quota early so that we don't have to account 789 * for quota initialization worst case in standard inode creating 790 * transaction 791 */ 792 if (owner) { 793 inode->i_mode = mode; 794 i_uid_write(inode, owner[0]); 795 i_gid_write(inode, owner[1]); 796 } else if (test_opt(sb, GRPID)) { 797 inode->i_mode = mode; 798 inode->i_uid = current_fsuid(); 799 inode->i_gid = dir->i_gid; 800 } else 801 inode_init_owner(inode, dir, mode); 802 err = dquot_initialize(inode); 803 if (err) 804 goto out; 805 806 if (!goal) 807 goal = sbi->s_inode_goal; 808 809 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) { 810 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb); 811 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb); 812 ret2 = 0; 813 goto got_group; 814 } 815 816 if (S_ISDIR(mode)) 817 ret2 = find_group_orlov(sb, dir, &group, mode, qstr); 818 else 819 ret2 = find_group_other(sb, dir, &group, mode); 820 821 got_group: 822 EXT4_I(dir)->i_last_alloc_group = group; 823 err = -ENOSPC; 824 if (ret2 == -1) 825 goto out; 826 827 /* 828 * Normally we will only go through one pass of this loop, 829 * unless we get unlucky and it turns out the group we selected 830 * had its last inode grabbed by someone else. 831 */ 832 for (i = 0; i < ngroups; i++, ino = 0) { 833 err = -EIO; 834 835 gdp = ext4_get_group_desc(sb, group, &group_desc_bh); 836 if (!gdp) 837 goto out; 838 839 /* 840 * Check free inodes count before loading bitmap. 841 */ 842 if (ext4_free_inodes_count(sb, gdp) == 0) { 843 if (++group == ngroups) 844 group = 0; 845 continue; 846 } 847 848 grp = ext4_get_group_info(sb, group); 849 /* Skip groups with already-known suspicious inode tables */ 850 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { 851 if (++group == ngroups) 852 group = 0; 853 continue; 854 } 855 856 brelse(inode_bitmap_bh); 857 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group); 858 /* Skip groups with suspicious inode tables */ 859 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) || 860 IS_ERR(inode_bitmap_bh)) { 861 inode_bitmap_bh = NULL; 862 if (++group == ngroups) 863 group = 0; 864 continue; 865 } 866 867 repeat_in_this_group: 868 ino = ext4_find_next_zero_bit((unsigned long *) 869 inode_bitmap_bh->b_data, 870 EXT4_INODES_PER_GROUP(sb), ino); 871 if (ino >= EXT4_INODES_PER_GROUP(sb)) 872 goto next_group; 873 if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) { 874 ext4_error(sb, "reserved inode found cleared - " 875 "inode=%lu", ino + 1); 876 continue; 877 } 878 if ((EXT4_SB(sb)->s_journal == NULL) && 879 recently_deleted(sb, group, ino)) { 880 ino++; 881 goto next_inode; 882 } 883 if (!handle) { 884 BUG_ON(nblocks <= 0); 885 handle = __ext4_journal_start_sb(dir->i_sb, line_no, 886 handle_type, nblocks, 887 0); 888 if (IS_ERR(handle)) { 889 err = PTR_ERR(handle); 890 ext4_std_error(sb, err); 891 goto out; 892 } 893 } 894 BUFFER_TRACE(inode_bitmap_bh, "get_write_access"); 895 err = ext4_journal_get_write_access(handle, inode_bitmap_bh); 896 if (err) { 897 ext4_std_error(sb, err); 898 goto out; 899 } 900 ext4_lock_group(sb, group); 901 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data); 902 ext4_unlock_group(sb, group); 903 ino++; /* the inode bitmap is zero-based */ 904 if (!ret2) 905 goto got; /* we grabbed the inode! */ 906 next_inode: 907 if (ino < EXT4_INODES_PER_GROUP(sb)) 908 goto repeat_in_this_group; 909 next_group: 910 if (++group == ngroups) 911 group = 0; 912 } 913 err = -ENOSPC; 914 goto out; 915 916 got: 917 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata"); 918 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh); 919 if (err) { 920 ext4_std_error(sb, err); 921 goto out; 922 } 923 924 BUFFER_TRACE(group_desc_bh, "get_write_access"); 925 err = ext4_journal_get_write_access(handle, group_desc_bh); 926 if (err) { 927 ext4_std_error(sb, err); 928 goto out; 929 } 930 931 /* We may have to initialize the block bitmap if it isn't already */ 932 if (ext4_has_group_desc_csum(sb) && 933 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { 934 struct buffer_head *block_bitmap_bh; 935 936 block_bitmap_bh = ext4_read_block_bitmap(sb, group); 937 if (IS_ERR(block_bitmap_bh)) { 938 err = PTR_ERR(block_bitmap_bh); 939 goto out; 940 } 941 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access"); 942 err = ext4_journal_get_write_access(handle, block_bitmap_bh); 943 if (err) { 944 brelse(block_bitmap_bh); 945 ext4_std_error(sb, err); 946 goto out; 947 } 948 949 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap"); 950 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh); 951 952 /* recheck and clear flag under lock if we still need to */ 953 ext4_lock_group(sb, group); 954 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { 955 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); 956 ext4_free_group_clusters_set(sb, gdp, 957 ext4_free_clusters_after_init(sb, group, gdp)); 958 ext4_block_bitmap_csum_set(sb, group, gdp, 959 block_bitmap_bh); 960 ext4_group_desc_csum_set(sb, group, gdp); 961 } 962 ext4_unlock_group(sb, group); 963 brelse(block_bitmap_bh); 964 965 if (err) { 966 ext4_std_error(sb, err); 967 goto out; 968 } 969 } 970 971 /* Update the relevant bg descriptor fields */ 972 if (ext4_has_group_desc_csum(sb)) { 973 int free; 974 struct ext4_group_info *grp = ext4_get_group_info(sb, group); 975 976 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */ 977 ext4_lock_group(sb, group); /* while we modify the bg desc */ 978 free = EXT4_INODES_PER_GROUP(sb) - 979 ext4_itable_unused_count(sb, gdp); 980 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { 981 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT); 982 free = 0; 983 } 984 /* 985 * Check the relative inode number against the last used 986 * relative inode number in this group. if it is greater 987 * we need to update the bg_itable_unused count 988 */ 989 if (ino > free) 990 ext4_itable_unused_set(sb, gdp, 991 (EXT4_INODES_PER_GROUP(sb) - ino)); 992 up_read(&grp->alloc_sem); 993 } else { 994 ext4_lock_group(sb, group); 995 } 996 997 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1); 998 if (S_ISDIR(mode)) { 999 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1); 1000 if (sbi->s_log_groups_per_flex) { 1001 ext4_group_t f = ext4_flex_group(sbi, group); 1002 1003 atomic_inc(&sbi->s_flex_groups[f].used_dirs); 1004 } 1005 } 1006 if (ext4_has_group_desc_csum(sb)) { 1007 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh, 1008 EXT4_INODES_PER_GROUP(sb) / 8); 1009 ext4_group_desc_csum_set(sb, group, gdp); 1010 } 1011 ext4_unlock_group(sb, group); 1012 1013 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata"); 1014 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh); 1015 if (err) { 1016 ext4_std_error(sb, err); 1017 goto out; 1018 } 1019 1020 percpu_counter_dec(&sbi->s_freeinodes_counter); 1021 if (S_ISDIR(mode)) 1022 percpu_counter_inc(&sbi->s_dirs_counter); 1023 1024 if (sbi->s_log_groups_per_flex) { 1025 flex_group = ext4_flex_group(sbi, group); 1026 atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes); 1027 } 1028 1029 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb); 1030 /* This is the optimal IO size (for stat), not the fs block size */ 1031 inode->i_blocks = 0; 1032 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime = 1033 ext4_current_time(inode); 1034 1035 memset(ei->i_data, 0, sizeof(ei->i_data)); 1036 ei->i_dir_start_lookup = 0; 1037 ei->i_disksize = 0; 1038 1039 /* Don't inherit extent flag from directory, amongst others. */ 1040 ei->i_flags = 1041 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED); 1042 ei->i_file_acl = 0; 1043 ei->i_dtime = 0; 1044 ei->i_block_group = group; 1045 ei->i_last_alloc_group = ~0; 1046 1047 ext4_set_inode_flags(inode); 1048 if (IS_DIRSYNC(inode)) 1049 ext4_handle_sync(handle); 1050 if (insert_inode_locked(inode) < 0) { 1051 /* 1052 * Likely a bitmap corruption causing inode to be allocated 1053 * twice. 1054 */ 1055 err = -EIO; 1056 ext4_error(sb, "failed to insert inode %lu: doubly allocated?", 1057 inode->i_ino); 1058 goto out; 1059 } 1060 spin_lock(&sbi->s_next_gen_lock); 1061 inode->i_generation = sbi->s_next_generation++; 1062 spin_unlock(&sbi->s_next_gen_lock); 1063 1064 /* Precompute checksum seed for inode metadata */ 1065 if (ext4_has_metadata_csum(sb)) { 1066 __u32 csum; 1067 __le32 inum = cpu_to_le32(inode->i_ino); 1068 __le32 gen = cpu_to_le32(inode->i_generation); 1069 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum, 1070 sizeof(inum)); 1071 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen, 1072 sizeof(gen)); 1073 } 1074 1075 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */ 1076 ext4_set_inode_state(inode, EXT4_STATE_NEW); 1077 1078 ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize; 1079 ei->i_inline_off = 0; 1080 if (ext4_has_feature_inline_data(sb)) 1081 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); 1082 ret = inode; 1083 err = dquot_alloc_inode(inode); 1084 if (err) 1085 goto fail_drop; 1086 1087 err = ext4_init_acl(handle, inode, dir); 1088 if (err) 1089 goto fail_free_drop; 1090 1091 err = ext4_init_security(handle, inode, dir, qstr); 1092 if (err) 1093 goto fail_free_drop; 1094 1095 if (ext4_has_feature_extents(sb)) { 1096 /* set extent flag only for directory, file and normal symlink*/ 1097 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) { 1098 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS); 1099 ext4_ext_tree_init(handle, inode); 1100 } 1101 } 1102 1103 if (ext4_handle_valid(handle)) { 1104 ei->i_sync_tid = handle->h_transaction->t_tid; 1105 ei->i_datasync_tid = handle->h_transaction->t_tid; 1106 } 1107 1108 if (encrypt) { 1109 err = ext4_inherit_context(dir, inode); 1110 if (err) 1111 goto fail_free_drop; 1112 } 1113 1114 err = ext4_mark_inode_dirty(handle, inode); 1115 if (err) { 1116 ext4_std_error(sb, err); 1117 goto fail_free_drop; 1118 } 1119 1120 ext4_debug("allocating inode %lu\n", inode->i_ino); 1121 trace_ext4_allocate_inode(inode, dir, mode); 1122 brelse(inode_bitmap_bh); 1123 return ret; 1124 1125 fail_free_drop: 1126 dquot_free_inode(inode); 1127 fail_drop: 1128 clear_nlink(inode); 1129 unlock_new_inode(inode); 1130 out: 1131 dquot_drop(inode); 1132 inode->i_flags |= S_NOQUOTA; 1133 iput(inode); 1134 brelse(inode_bitmap_bh); 1135 return ERR_PTR(err); 1136 } 1137 1138 /* Verify that we are loading a valid orphan from disk */ 1139 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino) 1140 { 1141 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count); 1142 ext4_group_t block_group; 1143 int bit; 1144 struct buffer_head *bitmap_bh; 1145 struct inode *inode = NULL; 1146 long err = -EIO; 1147 1148 /* Error cases - e2fsck has already cleaned up for us */ 1149 if (ino > max_ino) { 1150 ext4_warning(sb, "bad orphan ino %lu! e2fsck was run?", ino); 1151 err = -EFSCORRUPTED; 1152 goto error; 1153 } 1154 1155 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb); 1156 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb); 1157 bitmap_bh = ext4_read_inode_bitmap(sb, block_group); 1158 if (IS_ERR(bitmap_bh)) { 1159 err = PTR_ERR(bitmap_bh); 1160 ext4_warning(sb, "inode bitmap error %ld for orphan %lu", 1161 ino, err); 1162 goto error; 1163 } 1164 1165 /* Having the inode bit set should be a 100% indicator that this 1166 * is a valid orphan (no e2fsck run on fs). Orphans also include 1167 * inodes that were being truncated, so we can't check i_nlink==0. 1168 */ 1169 if (!ext4_test_bit(bit, bitmap_bh->b_data)) 1170 goto bad_orphan; 1171 1172 inode = ext4_iget(sb, ino); 1173 if (IS_ERR(inode)) 1174 goto iget_failed; 1175 1176 /* 1177 * If the orphans has i_nlinks > 0 then it should be able to be 1178 * truncated, otherwise it won't be removed from the orphan list 1179 * during processing and an infinite loop will result. 1180 */ 1181 if (inode->i_nlink && !ext4_can_truncate(inode)) 1182 goto bad_orphan; 1183 1184 if (NEXT_ORPHAN(inode) > max_ino) 1185 goto bad_orphan; 1186 brelse(bitmap_bh); 1187 return inode; 1188 1189 iget_failed: 1190 err = PTR_ERR(inode); 1191 inode = NULL; 1192 bad_orphan: 1193 ext4_warning(sb, "bad orphan inode %lu! e2fsck was run?", ino); 1194 printk(KERN_WARNING "ext4_test_bit(bit=%d, block=%llu) = %d\n", 1195 bit, (unsigned long long)bitmap_bh->b_blocknr, 1196 ext4_test_bit(bit, bitmap_bh->b_data)); 1197 printk(KERN_WARNING "inode=%p\n", inode); 1198 if (inode) { 1199 printk(KERN_WARNING "is_bad_inode(inode)=%d\n", 1200 is_bad_inode(inode)); 1201 printk(KERN_WARNING "NEXT_ORPHAN(inode)=%u\n", 1202 NEXT_ORPHAN(inode)); 1203 printk(KERN_WARNING "max_ino=%lu\n", max_ino); 1204 printk(KERN_WARNING "i_nlink=%u\n", inode->i_nlink); 1205 /* Avoid freeing blocks if we got a bad deleted inode */ 1206 if (inode->i_nlink == 0) 1207 inode->i_blocks = 0; 1208 iput(inode); 1209 } 1210 brelse(bitmap_bh); 1211 error: 1212 return ERR_PTR(err); 1213 } 1214 1215 unsigned long ext4_count_free_inodes(struct super_block *sb) 1216 { 1217 unsigned long desc_count; 1218 struct ext4_group_desc *gdp; 1219 ext4_group_t i, ngroups = ext4_get_groups_count(sb); 1220 #ifdef EXT4FS_DEBUG 1221 struct ext4_super_block *es; 1222 unsigned long bitmap_count, x; 1223 struct buffer_head *bitmap_bh = NULL; 1224 1225 es = EXT4_SB(sb)->s_es; 1226 desc_count = 0; 1227 bitmap_count = 0; 1228 gdp = NULL; 1229 for (i = 0; i < ngroups; i++) { 1230 gdp = ext4_get_group_desc(sb, i, NULL); 1231 if (!gdp) 1232 continue; 1233 desc_count += ext4_free_inodes_count(sb, gdp); 1234 brelse(bitmap_bh); 1235 bitmap_bh = ext4_read_inode_bitmap(sb, i); 1236 if (IS_ERR(bitmap_bh)) { 1237 bitmap_bh = NULL; 1238 continue; 1239 } 1240 1241 x = ext4_count_free(bitmap_bh->b_data, 1242 EXT4_INODES_PER_GROUP(sb) / 8); 1243 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n", 1244 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x); 1245 bitmap_count += x; 1246 } 1247 brelse(bitmap_bh); 1248 printk(KERN_DEBUG "ext4_count_free_inodes: " 1249 "stored = %u, computed = %lu, %lu\n", 1250 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count); 1251 return desc_count; 1252 #else 1253 desc_count = 0; 1254 for (i = 0; i < ngroups; i++) { 1255 gdp = ext4_get_group_desc(sb, i, NULL); 1256 if (!gdp) 1257 continue; 1258 desc_count += ext4_free_inodes_count(sb, gdp); 1259 cond_resched(); 1260 } 1261 return desc_count; 1262 #endif 1263 } 1264 1265 /* Called at mount-time, super-block is locked */ 1266 unsigned long ext4_count_dirs(struct super_block * sb) 1267 { 1268 unsigned long count = 0; 1269 ext4_group_t i, ngroups = ext4_get_groups_count(sb); 1270 1271 for (i = 0; i < ngroups; i++) { 1272 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL); 1273 if (!gdp) 1274 continue; 1275 count += ext4_used_dirs_count(sb, gdp); 1276 } 1277 return count; 1278 } 1279 1280 /* 1281 * Zeroes not yet zeroed inode table - just write zeroes through the whole 1282 * inode table. Must be called without any spinlock held. The only place 1283 * where it is called from on active part of filesystem is ext4lazyinit 1284 * thread, so we do not need any special locks, however we have to prevent 1285 * inode allocation from the current group, so we take alloc_sem lock, to 1286 * block ext4_new_inode() until we are finished. 1287 */ 1288 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group, 1289 int barrier) 1290 { 1291 struct ext4_group_info *grp = ext4_get_group_info(sb, group); 1292 struct ext4_sb_info *sbi = EXT4_SB(sb); 1293 struct ext4_group_desc *gdp = NULL; 1294 struct buffer_head *group_desc_bh; 1295 handle_t *handle; 1296 ext4_fsblk_t blk; 1297 int num, ret = 0, used_blks = 0; 1298 1299 /* This should not happen, but just to be sure check this */ 1300 if (sb->s_flags & MS_RDONLY) { 1301 ret = 1; 1302 goto out; 1303 } 1304 1305 gdp = ext4_get_group_desc(sb, group, &group_desc_bh); 1306 if (!gdp) 1307 goto out; 1308 1309 /* 1310 * We do not need to lock this, because we are the only one 1311 * handling this flag. 1312 */ 1313 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)) 1314 goto out; 1315 1316 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1); 1317 if (IS_ERR(handle)) { 1318 ret = PTR_ERR(handle); 1319 goto out; 1320 } 1321 1322 down_write(&grp->alloc_sem); 1323 /* 1324 * If inode bitmap was already initialized there may be some 1325 * used inodes so we need to skip blocks with used inodes in 1326 * inode table. 1327 */ 1328 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) 1329 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) - 1330 ext4_itable_unused_count(sb, gdp)), 1331 sbi->s_inodes_per_block); 1332 1333 if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) { 1334 ext4_error(sb, "Something is wrong with group %u: " 1335 "used itable blocks: %d; " 1336 "itable unused count: %u", 1337 group, used_blks, 1338 ext4_itable_unused_count(sb, gdp)); 1339 ret = 1; 1340 goto err_out; 1341 } 1342 1343 blk = ext4_inode_table(sb, gdp) + used_blks; 1344 num = sbi->s_itb_per_group - used_blks; 1345 1346 BUFFER_TRACE(group_desc_bh, "get_write_access"); 1347 ret = ext4_journal_get_write_access(handle, 1348 group_desc_bh); 1349 if (ret) 1350 goto err_out; 1351 1352 /* 1353 * Skip zeroout if the inode table is full. But we set the ZEROED 1354 * flag anyway, because obviously, when it is full it does not need 1355 * further zeroing. 1356 */ 1357 if (unlikely(num == 0)) 1358 goto skip_zeroout; 1359 1360 ext4_debug("going to zero out inode table in group %d\n", 1361 group); 1362 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS); 1363 if (ret < 0) 1364 goto err_out; 1365 if (barrier) 1366 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL); 1367 1368 skip_zeroout: 1369 ext4_lock_group(sb, group); 1370 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED); 1371 ext4_group_desc_csum_set(sb, group, gdp); 1372 ext4_unlock_group(sb, group); 1373 1374 BUFFER_TRACE(group_desc_bh, 1375 "call ext4_handle_dirty_metadata"); 1376 ret = ext4_handle_dirty_metadata(handle, NULL, 1377 group_desc_bh); 1378 1379 err_out: 1380 up_write(&grp->alloc_sem); 1381 ext4_journal_stop(handle); 1382 out: 1383 return ret; 1384 } 1385