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