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/jbd2.h> 18 #include <linux/stat.h> 19 #include <linux/string.h> 20 #include <linux/quotaops.h> 21 #include <linux/buffer_head.h> 22 #include <linux/random.h> 23 #include <linux/bitops.h> 24 #include <linux/blkdev.h> 25 #include <asm/byteorder.h> 26 #include "ext4.h" 27 #include "ext4_jbd2.h" 28 #include "xattr.h" 29 #include "acl.h" 30 #include "group.h" 31 32 /* 33 * ialloc.c contains the inodes allocation and deallocation routines 34 */ 35 36 /* 37 * The free inodes are managed by bitmaps. A file system contains several 38 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap 39 * block for inodes, N blocks for the inode table and data blocks. 40 * 41 * The file system contains group descriptors which are located after the 42 * super block. Each descriptor contains the number of the bitmap block and 43 * the free blocks count in the block. 44 */ 45 46 /* 47 * To avoid calling the atomic setbit hundreds or thousands of times, we only 48 * need to use it within a single byte (to ensure we get endianness right). 49 * We can use memset for the rest of the bitmap as there are no other users. 50 */ 51 void mark_bitmap_end(int start_bit, int end_bit, char *bitmap) 52 { 53 int i; 54 55 if (start_bit >= end_bit) 56 return; 57 58 ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit); 59 for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++) 60 ext4_set_bit(i, bitmap); 61 if (i < end_bit) 62 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3); 63 } 64 65 /* Initializes an uninitialized inode bitmap */ 66 unsigned ext4_init_inode_bitmap(struct super_block *sb, struct buffer_head *bh, 67 ext4_group_t block_group, 68 struct ext4_group_desc *gdp) 69 { 70 struct ext4_sb_info *sbi = EXT4_SB(sb); 71 72 J_ASSERT_BH(bh, buffer_locked(bh)); 73 74 /* If checksum is bad mark all blocks and inodes use to prevent 75 * allocation, essentially implementing a per-group read-only flag. */ 76 if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) { 77 ext4_error(sb, __func__, "Checksum bad for group %lu\n", 78 block_group); 79 gdp->bg_free_blocks_count = 0; 80 gdp->bg_free_inodes_count = 0; 81 gdp->bg_itable_unused = 0; 82 memset(bh->b_data, 0xff, sb->s_blocksize); 83 return 0; 84 } 85 86 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8); 87 mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), EXT4_BLOCKS_PER_GROUP(sb), 88 bh->b_data); 89 90 return EXT4_INODES_PER_GROUP(sb); 91 } 92 93 /* 94 * Read the inode allocation bitmap for a given block_group, reading 95 * into the specified slot in the superblock's bitmap cache. 96 * 97 * Return buffer_head of bitmap on success or NULL. 98 */ 99 static struct buffer_head * 100 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) 101 { 102 struct ext4_group_desc *desc; 103 struct buffer_head *bh = NULL; 104 ext4_fsblk_t bitmap_blk; 105 106 desc = ext4_get_group_desc(sb, block_group, NULL); 107 if (!desc) 108 return NULL; 109 bitmap_blk = ext4_inode_bitmap(sb, desc); 110 bh = sb_getblk(sb, bitmap_blk); 111 if (unlikely(!bh)) { 112 ext4_error(sb, __func__, 113 "Cannot read inode bitmap - " 114 "block_group = %lu, inode_bitmap = %llu", 115 block_group, bitmap_blk); 116 return NULL; 117 } 118 if (buffer_uptodate(bh) && 119 !(desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) 120 return bh; 121 122 lock_buffer(bh); 123 spin_lock(sb_bgl_lock(EXT4_SB(sb), block_group)); 124 if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { 125 ext4_init_inode_bitmap(sb, bh, block_group, desc); 126 set_buffer_uptodate(bh); 127 unlock_buffer(bh); 128 spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group)); 129 return bh; 130 } 131 spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group)); 132 if (bh_submit_read(bh) < 0) { 133 put_bh(bh); 134 ext4_error(sb, __func__, 135 "Cannot read inode bitmap - " 136 "block_group = %lu, inode_bitmap = %llu", 137 block_group, bitmap_blk); 138 return NULL; 139 } 140 return bh; 141 } 142 143 /* 144 * NOTE! When we get the inode, we're the only people 145 * that have access to it, and as such there are no 146 * race conditions we have to worry about. The inode 147 * is not on the hash-lists, and it cannot be reached 148 * through the filesystem because the directory entry 149 * has been deleted earlier. 150 * 151 * HOWEVER: we must make sure that we get no aliases, 152 * which means that we have to call "clear_inode()" 153 * _before_ we mark the inode not in use in the inode 154 * bitmaps. Otherwise a newly created file might use 155 * the same inode number (not actually the same pointer 156 * though), and then we'd have two inodes sharing the 157 * same inode number and space on the harddisk. 158 */ 159 void ext4_free_inode(handle_t *handle, struct inode *inode) 160 { 161 struct super_block *sb = inode->i_sb; 162 int is_directory; 163 unsigned long ino; 164 struct buffer_head *bitmap_bh = NULL; 165 struct buffer_head *bh2; 166 ext4_group_t block_group; 167 unsigned long bit; 168 struct ext4_group_desc *gdp; 169 struct ext4_super_block *es; 170 struct ext4_sb_info *sbi; 171 int fatal = 0, err; 172 ext4_group_t flex_group; 173 174 if (atomic_read(&inode->i_count) > 1) { 175 printk(KERN_ERR "ext4_free_inode: inode has count=%d\n", 176 atomic_read(&inode->i_count)); 177 return; 178 } 179 if (inode->i_nlink) { 180 printk(KERN_ERR "ext4_free_inode: inode has nlink=%d\n", 181 inode->i_nlink); 182 return; 183 } 184 if (!sb) { 185 printk(KERN_ERR "ext4_free_inode: inode on " 186 "nonexistent device\n"); 187 return; 188 } 189 sbi = EXT4_SB(sb); 190 191 ino = inode->i_ino; 192 ext4_debug("freeing inode %lu\n", ino); 193 194 /* 195 * Note: we must free any quota before locking the superblock, 196 * as writing the quota to disk may need the lock as well. 197 */ 198 DQUOT_INIT(inode); 199 ext4_xattr_delete_inode(handle, inode); 200 DQUOT_FREE_INODE(inode); 201 DQUOT_DROP(inode); 202 203 is_directory = S_ISDIR(inode->i_mode); 204 205 /* Do this BEFORE marking the inode not in use or returning an error */ 206 clear_inode(inode); 207 208 es = EXT4_SB(sb)->s_es; 209 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { 210 ext4_error(sb, "ext4_free_inode", 211 "reserved or nonexistent inode %lu", ino); 212 goto error_return; 213 } 214 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb); 215 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb); 216 bitmap_bh = ext4_read_inode_bitmap(sb, block_group); 217 if (!bitmap_bh) 218 goto error_return; 219 220 BUFFER_TRACE(bitmap_bh, "get_write_access"); 221 fatal = ext4_journal_get_write_access(handle, bitmap_bh); 222 if (fatal) 223 goto error_return; 224 225 /* Ok, now we can actually update the inode bitmaps.. */ 226 if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group), 227 bit, bitmap_bh->b_data)) 228 ext4_error(sb, "ext4_free_inode", 229 "bit already cleared for inode %lu", ino); 230 else { 231 gdp = ext4_get_group_desc(sb, block_group, &bh2); 232 233 BUFFER_TRACE(bh2, "get_write_access"); 234 fatal = ext4_journal_get_write_access(handle, bh2); 235 if (fatal) goto error_return; 236 237 if (gdp) { 238 spin_lock(sb_bgl_lock(sbi, block_group)); 239 le16_add_cpu(&gdp->bg_free_inodes_count, 1); 240 if (is_directory) 241 le16_add_cpu(&gdp->bg_used_dirs_count, -1); 242 gdp->bg_checksum = ext4_group_desc_csum(sbi, 243 block_group, gdp); 244 spin_unlock(sb_bgl_lock(sbi, block_group)); 245 percpu_counter_inc(&sbi->s_freeinodes_counter); 246 if (is_directory) 247 percpu_counter_dec(&sbi->s_dirs_counter); 248 249 if (sbi->s_log_groups_per_flex) { 250 flex_group = ext4_flex_group(sbi, block_group); 251 spin_lock(sb_bgl_lock(sbi, flex_group)); 252 sbi->s_flex_groups[flex_group].free_inodes++; 253 spin_unlock(sb_bgl_lock(sbi, flex_group)); 254 } 255 } 256 BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata"); 257 err = ext4_journal_dirty_metadata(handle, bh2); 258 if (!fatal) fatal = err; 259 } 260 BUFFER_TRACE(bitmap_bh, "call ext4_journal_dirty_metadata"); 261 err = ext4_journal_dirty_metadata(handle, bitmap_bh); 262 if (!fatal) 263 fatal = err; 264 sb->s_dirt = 1; 265 error_return: 266 brelse(bitmap_bh); 267 ext4_std_error(sb, fatal); 268 } 269 270 /* 271 * There are two policies for allocating an inode. If the new inode is 272 * a directory, then a forward search is made for a block group with both 273 * free space and a low directory-to-inode ratio; if that fails, then of 274 * the groups with above-average free space, that group with the fewest 275 * directories already is chosen. 276 * 277 * For other inodes, search forward from the parent directory\'s block 278 * group to find a free inode. 279 */ 280 static int find_group_dir(struct super_block *sb, struct inode *parent, 281 ext4_group_t *best_group) 282 { 283 ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count; 284 unsigned int freei, avefreei; 285 struct ext4_group_desc *desc, *best_desc = NULL; 286 ext4_group_t group; 287 int ret = -1; 288 289 freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter); 290 avefreei = freei / ngroups; 291 292 for (group = 0; group < ngroups; group++) { 293 desc = ext4_get_group_desc(sb, group, NULL); 294 if (!desc || !desc->bg_free_inodes_count) 295 continue; 296 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei) 297 continue; 298 if (!best_desc || 299 (le16_to_cpu(desc->bg_free_blocks_count) > 300 le16_to_cpu(best_desc->bg_free_blocks_count))) { 301 *best_group = group; 302 best_desc = desc; 303 ret = 0; 304 } 305 } 306 return ret; 307 } 308 309 #define free_block_ratio 10 310 311 static int find_group_flex(struct super_block *sb, struct inode *parent, 312 ext4_group_t *best_group) 313 { 314 struct ext4_sb_info *sbi = EXT4_SB(sb); 315 struct ext4_group_desc *desc; 316 struct buffer_head *bh; 317 struct flex_groups *flex_group = sbi->s_flex_groups; 318 ext4_group_t parent_group = EXT4_I(parent)->i_block_group; 319 ext4_group_t parent_fbg_group = ext4_flex_group(sbi, parent_group); 320 ext4_group_t ngroups = sbi->s_groups_count; 321 int flex_size = ext4_flex_bg_size(sbi); 322 ext4_group_t best_flex = parent_fbg_group; 323 int blocks_per_flex = sbi->s_blocks_per_group * flex_size; 324 int flexbg_free_blocks; 325 int flex_freeb_ratio; 326 ext4_group_t n_fbg_groups; 327 ext4_group_t i; 328 329 n_fbg_groups = (sbi->s_groups_count + flex_size - 1) >> 330 sbi->s_log_groups_per_flex; 331 332 find_close_to_parent: 333 flexbg_free_blocks = flex_group[best_flex].free_blocks; 334 flex_freeb_ratio = flexbg_free_blocks * 100 / blocks_per_flex; 335 if (flex_group[best_flex].free_inodes && 336 flex_freeb_ratio > free_block_ratio) 337 goto found_flexbg; 338 339 if (best_flex && best_flex == parent_fbg_group) { 340 best_flex--; 341 goto find_close_to_parent; 342 } 343 344 for (i = 0; i < n_fbg_groups; i++) { 345 if (i == parent_fbg_group || i == parent_fbg_group - 1) 346 continue; 347 348 flexbg_free_blocks = flex_group[i].free_blocks; 349 flex_freeb_ratio = flexbg_free_blocks * 100 / blocks_per_flex; 350 351 if (flex_freeb_ratio > free_block_ratio && 352 flex_group[i].free_inodes) { 353 best_flex = i; 354 goto found_flexbg; 355 } 356 357 if (flex_group[best_flex].free_inodes == 0 || 358 (flex_group[i].free_blocks > 359 flex_group[best_flex].free_blocks && 360 flex_group[i].free_inodes)) 361 best_flex = i; 362 } 363 364 if (!flex_group[best_flex].free_inodes || 365 !flex_group[best_flex].free_blocks) 366 return -1; 367 368 found_flexbg: 369 for (i = best_flex * flex_size; i < ngroups && 370 i < (best_flex + 1) * flex_size; i++) { 371 desc = ext4_get_group_desc(sb, i, &bh); 372 if (le16_to_cpu(desc->bg_free_inodes_count)) { 373 *best_group = i; 374 goto out; 375 } 376 } 377 378 return -1; 379 out: 380 return 0; 381 } 382 383 /* 384 * Orlov's allocator for directories. 385 * 386 * We always try to spread first-level directories. 387 * 388 * If there are blockgroups with both free inodes and free blocks counts 389 * not worse than average we return one with smallest directory count. 390 * Otherwise we simply return a random group. 391 * 392 * For the rest rules look so: 393 * 394 * It's OK to put directory into a group unless 395 * it has too many directories already (max_dirs) or 396 * it has too few free inodes left (min_inodes) or 397 * it has too few free blocks left (min_blocks) or 398 * it's already running too large debt (max_debt). 399 * Parent's group is preferred, if it doesn't satisfy these 400 * conditions we search cyclically through the rest. If none 401 * of the groups look good we just look for a group with more 402 * free inodes than average (starting at parent's group). 403 * 404 * Debt is incremented each time we allocate a directory and decremented 405 * when we allocate an inode, within 0--255. 406 */ 407 408 #define INODE_COST 64 409 #define BLOCK_COST 256 410 411 static int find_group_orlov(struct super_block *sb, struct inode *parent, 412 ext4_group_t *group) 413 { 414 ext4_group_t parent_group = EXT4_I(parent)->i_block_group; 415 struct ext4_sb_info *sbi = EXT4_SB(sb); 416 struct ext4_super_block *es = sbi->s_es; 417 ext4_group_t ngroups = sbi->s_groups_count; 418 int inodes_per_group = EXT4_INODES_PER_GROUP(sb); 419 unsigned int freei, avefreei; 420 ext4_fsblk_t freeb, avefreeb; 421 ext4_fsblk_t blocks_per_dir; 422 unsigned int ndirs; 423 int max_debt, max_dirs, min_inodes; 424 ext4_grpblk_t min_blocks; 425 ext4_group_t i; 426 struct ext4_group_desc *desc; 427 428 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter); 429 avefreei = freei / ngroups; 430 freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter); 431 avefreeb = freeb; 432 do_div(avefreeb, ngroups); 433 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter); 434 435 if ((parent == sb->s_root->d_inode) || 436 (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) { 437 int best_ndir = inodes_per_group; 438 ext4_group_t grp; 439 int ret = -1; 440 441 get_random_bytes(&grp, sizeof(grp)); 442 parent_group = (unsigned)grp % ngroups; 443 for (i = 0; i < ngroups; i++) { 444 grp = (parent_group + i) % ngroups; 445 desc = ext4_get_group_desc(sb, grp, NULL); 446 if (!desc || !desc->bg_free_inodes_count) 447 continue; 448 if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir) 449 continue; 450 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei) 451 continue; 452 if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb) 453 continue; 454 *group = grp; 455 ret = 0; 456 best_ndir = le16_to_cpu(desc->bg_used_dirs_count); 457 } 458 if (ret == 0) 459 return ret; 460 goto fallback; 461 } 462 463 blocks_per_dir = ext4_blocks_count(es) - freeb; 464 do_div(blocks_per_dir, ndirs); 465 466 max_dirs = ndirs / ngroups + inodes_per_group / 16; 467 min_inodes = avefreei - inodes_per_group / 4; 468 min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb) / 4; 469 470 max_debt = EXT4_BLOCKS_PER_GROUP(sb); 471 max_debt /= max_t(int, blocks_per_dir, BLOCK_COST); 472 if (max_debt * INODE_COST > inodes_per_group) 473 max_debt = inodes_per_group / INODE_COST; 474 if (max_debt > 255) 475 max_debt = 255; 476 if (max_debt == 0) 477 max_debt = 1; 478 479 for (i = 0; i < ngroups; i++) { 480 *group = (parent_group + i) % ngroups; 481 desc = ext4_get_group_desc(sb, *group, NULL); 482 if (!desc || !desc->bg_free_inodes_count) 483 continue; 484 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs) 485 continue; 486 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes) 487 continue; 488 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks) 489 continue; 490 return 0; 491 } 492 493 fallback: 494 for (i = 0; i < ngroups; i++) { 495 *group = (parent_group + i) % ngroups; 496 desc = ext4_get_group_desc(sb, *group, NULL); 497 if (desc && desc->bg_free_inodes_count && 498 le16_to_cpu(desc->bg_free_inodes_count) >= avefreei) 499 return 0; 500 } 501 502 if (avefreei) { 503 /* 504 * The free-inodes counter is approximate, and for really small 505 * filesystems the above test can fail to find any blockgroups 506 */ 507 avefreei = 0; 508 goto fallback; 509 } 510 511 return -1; 512 } 513 514 static int find_group_other(struct super_block *sb, struct inode *parent, 515 ext4_group_t *group) 516 { 517 ext4_group_t parent_group = EXT4_I(parent)->i_block_group; 518 ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count; 519 struct ext4_group_desc *desc; 520 ext4_group_t i; 521 522 /* 523 * Try to place the inode in its parent directory 524 */ 525 *group = parent_group; 526 desc = ext4_get_group_desc(sb, *group, NULL); 527 if (desc && le16_to_cpu(desc->bg_free_inodes_count) && 528 le16_to_cpu(desc->bg_free_blocks_count)) 529 return 0; 530 531 /* 532 * We're going to place this inode in a different blockgroup from its 533 * parent. We want to cause files in a common directory to all land in 534 * the same blockgroup. But we want files which are in a different 535 * directory which shares a blockgroup with our parent to land in a 536 * different blockgroup. 537 * 538 * So add our directory's i_ino into the starting point for the hash. 539 */ 540 *group = (*group + parent->i_ino) % ngroups; 541 542 /* 543 * Use a quadratic hash to find a group with a free inode and some free 544 * blocks. 545 */ 546 for (i = 1; i < ngroups; i <<= 1) { 547 *group += i; 548 if (*group >= ngroups) 549 *group -= ngroups; 550 desc = ext4_get_group_desc(sb, *group, NULL); 551 if (desc && le16_to_cpu(desc->bg_free_inodes_count) && 552 le16_to_cpu(desc->bg_free_blocks_count)) 553 return 0; 554 } 555 556 /* 557 * That failed: try linear search for a free inode, even if that group 558 * has no free blocks. 559 */ 560 *group = parent_group; 561 for (i = 0; i < ngroups; i++) { 562 if (++*group >= ngroups) 563 *group = 0; 564 desc = ext4_get_group_desc(sb, *group, NULL); 565 if (desc && le16_to_cpu(desc->bg_free_inodes_count)) 566 return 0; 567 } 568 569 return -1; 570 } 571 572 /* 573 * There are two policies for allocating an inode. If the new inode is 574 * a directory, then a forward search is made for a block group with both 575 * free space and a low directory-to-inode ratio; if that fails, then of 576 * the groups with above-average free space, that group with the fewest 577 * directories already is chosen. 578 * 579 * For other inodes, search forward from the parent directory's block 580 * group to find a free inode. 581 */ 582 struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode) 583 { 584 struct super_block *sb; 585 struct buffer_head *bitmap_bh = NULL; 586 struct buffer_head *bh2; 587 ext4_group_t group = 0; 588 unsigned long ino = 0; 589 struct inode *inode; 590 struct ext4_group_desc *gdp = NULL; 591 struct ext4_super_block *es; 592 struct ext4_inode_info *ei; 593 struct ext4_sb_info *sbi; 594 int ret2, err = 0; 595 struct inode *ret; 596 ext4_group_t i; 597 int free = 0; 598 ext4_group_t flex_group; 599 600 /* Cannot create files in a deleted directory */ 601 if (!dir || !dir->i_nlink) 602 return ERR_PTR(-EPERM); 603 604 sb = dir->i_sb; 605 inode = new_inode(sb); 606 if (!inode) 607 return ERR_PTR(-ENOMEM); 608 ei = EXT4_I(inode); 609 610 sbi = EXT4_SB(sb); 611 es = sbi->s_es; 612 613 if (sbi->s_log_groups_per_flex) { 614 ret2 = find_group_flex(sb, dir, &group); 615 goto got_group; 616 } 617 618 if (S_ISDIR(mode)) { 619 if (test_opt(sb, OLDALLOC)) 620 ret2 = find_group_dir(sb, dir, &group); 621 else 622 ret2 = find_group_orlov(sb, dir, &group); 623 } else 624 ret2 = find_group_other(sb, dir, &group); 625 626 got_group: 627 err = -ENOSPC; 628 if (ret2 == -1) 629 goto out; 630 631 for (i = 0; i < sbi->s_groups_count; i++) { 632 err = -EIO; 633 634 gdp = ext4_get_group_desc(sb, group, &bh2); 635 if (!gdp) 636 goto fail; 637 638 brelse(bitmap_bh); 639 bitmap_bh = ext4_read_inode_bitmap(sb, group); 640 if (!bitmap_bh) 641 goto fail; 642 643 ino = 0; 644 645 repeat_in_this_group: 646 ino = ext4_find_next_zero_bit((unsigned long *) 647 bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb), ino); 648 if (ino < EXT4_INODES_PER_GROUP(sb)) { 649 650 BUFFER_TRACE(bitmap_bh, "get_write_access"); 651 err = ext4_journal_get_write_access(handle, bitmap_bh); 652 if (err) 653 goto fail; 654 655 if (!ext4_set_bit_atomic(sb_bgl_lock(sbi, group), 656 ino, bitmap_bh->b_data)) { 657 /* we won it */ 658 BUFFER_TRACE(bitmap_bh, 659 "call ext4_journal_dirty_metadata"); 660 err = ext4_journal_dirty_metadata(handle, 661 bitmap_bh); 662 if (err) 663 goto fail; 664 goto got; 665 } 666 /* we lost it */ 667 jbd2_journal_release_buffer(handle, bitmap_bh); 668 669 if (++ino < EXT4_INODES_PER_GROUP(sb)) 670 goto repeat_in_this_group; 671 } 672 673 /* 674 * This case is possible in concurrent environment. It is very 675 * rare. We cannot repeat the find_group_xxx() call because 676 * that will simply return the same blockgroup, because the 677 * group descriptor metadata has not yet been updated. 678 * So we just go onto the next blockgroup. 679 */ 680 if (++group == sbi->s_groups_count) 681 group = 0; 682 } 683 err = -ENOSPC; 684 goto out; 685 686 got: 687 ino++; 688 if ((group == 0 && ino < EXT4_FIRST_INO(sb)) || 689 ino > EXT4_INODES_PER_GROUP(sb)) { 690 ext4_error(sb, __func__, 691 "reserved inode or inode > inodes count - " 692 "block_group = %lu, inode=%lu", group, 693 ino + group * EXT4_INODES_PER_GROUP(sb)); 694 err = -EIO; 695 goto fail; 696 } 697 698 BUFFER_TRACE(bh2, "get_write_access"); 699 err = ext4_journal_get_write_access(handle, bh2); 700 if (err) goto fail; 701 702 /* We may have to initialize the block bitmap if it isn't already */ 703 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) && 704 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { 705 struct buffer_head *block_bh = ext4_read_block_bitmap(sb, group); 706 707 BUFFER_TRACE(block_bh, "get block bitmap access"); 708 err = ext4_journal_get_write_access(handle, block_bh); 709 if (err) { 710 brelse(block_bh); 711 goto fail; 712 } 713 714 free = 0; 715 spin_lock(sb_bgl_lock(sbi, group)); 716 /* recheck and clear flag under lock if we still need to */ 717 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { 718 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); 719 free = ext4_free_blocks_after_init(sb, group, gdp); 720 gdp->bg_free_blocks_count = cpu_to_le16(free); 721 } 722 spin_unlock(sb_bgl_lock(sbi, group)); 723 724 /* Don't need to dirty bitmap block if we didn't change it */ 725 if (free) { 726 BUFFER_TRACE(block_bh, "dirty block bitmap"); 727 err = ext4_journal_dirty_metadata(handle, block_bh); 728 } 729 730 brelse(block_bh); 731 if (err) 732 goto fail; 733 } 734 735 spin_lock(sb_bgl_lock(sbi, group)); 736 /* If we didn't allocate from within the initialized part of the inode 737 * table then we need to initialize up to this inode. */ 738 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { 739 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { 740 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT); 741 742 /* When marking the block group with 743 * ~EXT4_BG_INODE_UNINIT we don't want to depend 744 * on the value of bg_itable_unused even though 745 * mke2fs could have initialized the same for us. 746 * Instead we calculated the value below 747 */ 748 749 free = 0; 750 } else { 751 free = EXT4_INODES_PER_GROUP(sb) - 752 le16_to_cpu(gdp->bg_itable_unused); 753 } 754 755 /* 756 * Check the relative inode number against the last used 757 * relative inode number in this group. if it is greater 758 * we need to update the bg_itable_unused count 759 * 760 */ 761 if (ino > free) 762 gdp->bg_itable_unused = 763 cpu_to_le16(EXT4_INODES_PER_GROUP(sb) - ino); 764 } 765 766 le16_add_cpu(&gdp->bg_free_inodes_count, -1); 767 if (S_ISDIR(mode)) { 768 le16_add_cpu(&gdp->bg_used_dirs_count, 1); 769 } 770 gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp); 771 spin_unlock(sb_bgl_lock(sbi, group)); 772 BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata"); 773 err = ext4_journal_dirty_metadata(handle, bh2); 774 if (err) goto fail; 775 776 percpu_counter_dec(&sbi->s_freeinodes_counter); 777 if (S_ISDIR(mode)) 778 percpu_counter_inc(&sbi->s_dirs_counter); 779 sb->s_dirt = 1; 780 781 if (sbi->s_log_groups_per_flex) { 782 flex_group = ext4_flex_group(sbi, group); 783 spin_lock(sb_bgl_lock(sbi, flex_group)); 784 sbi->s_flex_groups[flex_group].free_inodes--; 785 spin_unlock(sb_bgl_lock(sbi, flex_group)); 786 } 787 788 inode->i_uid = current->fsuid; 789 if (test_opt(sb, GRPID)) 790 inode->i_gid = dir->i_gid; 791 else if (dir->i_mode & S_ISGID) { 792 inode->i_gid = dir->i_gid; 793 if (S_ISDIR(mode)) 794 mode |= S_ISGID; 795 } else 796 inode->i_gid = current->fsgid; 797 inode->i_mode = mode; 798 799 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb); 800 /* This is the optimal IO size (for stat), not the fs block size */ 801 inode->i_blocks = 0; 802 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime = 803 ext4_current_time(inode); 804 805 memset(ei->i_data, 0, sizeof(ei->i_data)); 806 ei->i_dir_start_lookup = 0; 807 ei->i_disksize = 0; 808 809 /* 810 * Don't inherit extent flag from directory. We set extent flag on 811 * newly created directory and file only if -o extent mount option is 812 * specified 813 */ 814 ei->i_flags = EXT4_I(dir)->i_flags & ~(EXT4_INDEX_FL|EXT4_EXTENTS_FL); 815 if (S_ISLNK(mode)) 816 ei->i_flags &= ~(EXT4_IMMUTABLE_FL|EXT4_APPEND_FL); 817 /* dirsync only applies to directories */ 818 if (!S_ISDIR(mode)) 819 ei->i_flags &= ~EXT4_DIRSYNC_FL; 820 ei->i_file_acl = 0; 821 ei->i_dtime = 0; 822 ei->i_block_group = group; 823 824 ext4_set_inode_flags(inode); 825 if (IS_DIRSYNC(inode)) 826 handle->h_sync = 1; 827 insert_inode_hash(inode); 828 spin_lock(&sbi->s_next_gen_lock); 829 inode->i_generation = sbi->s_next_generation++; 830 spin_unlock(&sbi->s_next_gen_lock); 831 832 ei->i_state = EXT4_STATE_NEW; 833 834 ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize; 835 836 ret = inode; 837 if (DQUOT_ALLOC_INODE(inode)) { 838 err = -EDQUOT; 839 goto fail_drop; 840 } 841 842 err = ext4_init_acl(handle, inode, dir); 843 if (err) 844 goto fail_free_drop; 845 846 err = ext4_init_security(handle, inode, dir); 847 if (err) 848 goto fail_free_drop; 849 850 if (test_opt(sb, EXTENTS)) { 851 /* set extent flag only for directory, file and normal symlink*/ 852 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) { 853 EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL; 854 ext4_ext_tree_init(handle, inode); 855 } 856 } 857 858 err = ext4_mark_inode_dirty(handle, inode); 859 if (err) { 860 ext4_std_error(sb, err); 861 goto fail_free_drop; 862 } 863 864 ext4_debug("allocating inode %lu\n", inode->i_ino); 865 goto really_out; 866 fail: 867 ext4_std_error(sb, err); 868 out: 869 iput(inode); 870 ret = ERR_PTR(err); 871 really_out: 872 brelse(bitmap_bh); 873 return ret; 874 875 fail_free_drop: 876 DQUOT_FREE_INODE(inode); 877 878 fail_drop: 879 DQUOT_DROP(inode); 880 inode->i_flags |= S_NOQUOTA; 881 inode->i_nlink = 0; 882 iput(inode); 883 brelse(bitmap_bh); 884 return ERR_PTR(err); 885 } 886 887 /* Verify that we are loading a valid orphan from disk */ 888 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino) 889 { 890 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count); 891 ext4_group_t block_group; 892 int bit; 893 struct buffer_head *bitmap_bh; 894 struct inode *inode = NULL; 895 long err = -EIO; 896 897 /* Error cases - e2fsck has already cleaned up for us */ 898 if (ino > max_ino) { 899 ext4_warning(sb, __func__, 900 "bad orphan ino %lu! e2fsck was run?", ino); 901 goto error; 902 } 903 904 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb); 905 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb); 906 bitmap_bh = ext4_read_inode_bitmap(sb, block_group); 907 if (!bitmap_bh) { 908 ext4_warning(sb, __func__, 909 "inode bitmap error for orphan %lu", ino); 910 goto error; 911 } 912 913 /* Having the inode bit set should be a 100% indicator that this 914 * is a valid orphan (no e2fsck run on fs). Orphans also include 915 * inodes that were being truncated, so we can't check i_nlink==0. 916 */ 917 if (!ext4_test_bit(bit, bitmap_bh->b_data)) 918 goto bad_orphan; 919 920 inode = ext4_iget(sb, ino); 921 if (IS_ERR(inode)) 922 goto iget_failed; 923 924 /* 925 * If the orphans has i_nlinks > 0 then it should be able to be 926 * truncated, otherwise it won't be removed from the orphan list 927 * during processing and an infinite loop will result. 928 */ 929 if (inode->i_nlink && !ext4_can_truncate(inode)) 930 goto bad_orphan; 931 932 if (NEXT_ORPHAN(inode) > max_ino) 933 goto bad_orphan; 934 brelse(bitmap_bh); 935 return inode; 936 937 iget_failed: 938 err = PTR_ERR(inode); 939 inode = NULL; 940 bad_orphan: 941 ext4_warning(sb, __func__, 942 "bad orphan inode %lu! e2fsck was run?", ino); 943 printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n", 944 bit, (unsigned long long)bitmap_bh->b_blocknr, 945 ext4_test_bit(bit, bitmap_bh->b_data)); 946 printk(KERN_NOTICE "inode=%p\n", inode); 947 if (inode) { 948 printk(KERN_NOTICE "is_bad_inode(inode)=%d\n", 949 is_bad_inode(inode)); 950 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n", 951 NEXT_ORPHAN(inode)); 952 printk(KERN_NOTICE "max_ino=%lu\n", max_ino); 953 printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink); 954 /* Avoid freeing blocks if we got a bad deleted inode */ 955 if (inode->i_nlink == 0) 956 inode->i_blocks = 0; 957 iput(inode); 958 } 959 brelse(bitmap_bh); 960 error: 961 return ERR_PTR(err); 962 } 963 964 unsigned long ext4_count_free_inodes(struct super_block *sb) 965 { 966 unsigned long desc_count; 967 struct ext4_group_desc *gdp; 968 ext4_group_t i; 969 #ifdef EXT4FS_DEBUG 970 struct ext4_super_block *es; 971 unsigned long bitmap_count, x; 972 struct buffer_head *bitmap_bh = NULL; 973 974 es = EXT4_SB(sb)->s_es; 975 desc_count = 0; 976 bitmap_count = 0; 977 gdp = NULL; 978 for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) { 979 gdp = ext4_get_group_desc(sb, i, NULL); 980 if (!gdp) 981 continue; 982 desc_count += le16_to_cpu(gdp->bg_free_inodes_count); 983 brelse(bitmap_bh); 984 bitmap_bh = ext4_read_inode_bitmap(sb, i); 985 if (!bitmap_bh) 986 continue; 987 988 x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8); 989 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n", 990 i, le16_to_cpu(gdp->bg_free_inodes_count), x); 991 bitmap_count += x; 992 } 993 brelse(bitmap_bh); 994 printk(KERN_DEBUG "ext4_count_free_inodes: " 995 "stored = %u, computed = %lu, %lu\n", 996 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count); 997 return desc_count; 998 #else 999 desc_count = 0; 1000 for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) { 1001 gdp = ext4_get_group_desc(sb, i, NULL); 1002 if (!gdp) 1003 continue; 1004 desc_count += le16_to_cpu(gdp->bg_free_inodes_count); 1005 cond_resched(); 1006 } 1007 return desc_count; 1008 #endif 1009 } 1010 1011 /* Called at mount-time, super-block is locked */ 1012 unsigned long ext4_count_dirs(struct super_block * sb) 1013 { 1014 unsigned long count = 0; 1015 ext4_group_t i; 1016 1017 for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) { 1018 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL); 1019 if (!gdp) 1020 continue; 1021 count += le16_to_cpu(gdp->bg_used_dirs_count); 1022 } 1023 return count; 1024 } 1025 1026