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 %u", 78 block_group); 79 ext4_free_blks_set(sb, gdp, 0); 80 ext4_free_inodes_set(sb, gdp, 0); 81 ext4_itable_unused_set(sb, gdp, 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), sb->s_blocksize * 8, 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 = %u, inode_bitmap = %llu", 115 block_group, bitmap_blk); 116 return NULL; 117 } 118 if (bitmap_uptodate(bh)) 119 return bh; 120 121 lock_buffer(bh); 122 if (bitmap_uptodate(bh)) { 123 unlock_buffer(bh); 124 return bh; 125 } 126 spin_lock(sb_bgl_lock(EXT4_SB(sb), block_group)); 127 if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { 128 ext4_init_inode_bitmap(sb, bh, block_group, desc); 129 set_bitmap_uptodate(bh); 130 set_buffer_uptodate(bh); 131 spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group)); 132 unlock_buffer(bh); 133 return bh; 134 } 135 spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group)); 136 if (buffer_uptodate(bh)) { 137 /* 138 * if not uninit if bh is uptodate, 139 * bitmap is also uptodate 140 */ 141 set_bitmap_uptodate(bh); 142 unlock_buffer(bh); 143 return bh; 144 } 145 /* 146 * submit the buffer_head for read. We can 147 * safely mark the bitmap as uptodate now. 148 * We do it here so the bitmap uptodate bit 149 * get set with buffer lock held. 150 */ 151 set_bitmap_uptodate(bh); 152 if (bh_submit_read(bh) < 0) { 153 put_bh(bh); 154 ext4_error(sb, __func__, 155 "Cannot read inode bitmap - " 156 "block_group = %u, inode_bitmap = %llu", 157 block_group, bitmap_blk); 158 return NULL; 159 } 160 return bh; 161 } 162 163 /* 164 * NOTE! When we get the inode, we're the only people 165 * that have access to it, and as such there are no 166 * race conditions we have to worry about. The inode 167 * is not on the hash-lists, and it cannot be reached 168 * through the filesystem because the directory entry 169 * has been deleted earlier. 170 * 171 * HOWEVER: we must make sure that we get no aliases, 172 * which means that we have to call "clear_inode()" 173 * _before_ we mark the inode not in use in the inode 174 * bitmaps. Otherwise a newly created file might use 175 * the same inode number (not actually the same pointer 176 * though), and then we'd have two inodes sharing the 177 * same inode number and space on the harddisk. 178 */ 179 void ext4_free_inode(handle_t *handle, struct inode *inode) 180 { 181 struct super_block *sb = inode->i_sb; 182 int is_directory; 183 unsigned long ino; 184 struct buffer_head *bitmap_bh = NULL; 185 struct buffer_head *bh2; 186 ext4_group_t block_group; 187 unsigned long bit; 188 struct ext4_group_desc *gdp; 189 struct ext4_super_block *es; 190 struct ext4_sb_info *sbi; 191 int fatal = 0, err, count, cleared; 192 ext4_group_t flex_group; 193 194 if (atomic_read(&inode->i_count) > 1) { 195 printk(KERN_ERR "ext4_free_inode: inode has count=%d\n", 196 atomic_read(&inode->i_count)); 197 return; 198 } 199 if (inode->i_nlink) { 200 printk(KERN_ERR "ext4_free_inode: inode has nlink=%d\n", 201 inode->i_nlink); 202 return; 203 } 204 if (!sb) { 205 printk(KERN_ERR "ext4_free_inode: inode on " 206 "nonexistent device\n"); 207 return; 208 } 209 sbi = EXT4_SB(sb); 210 211 ino = inode->i_ino; 212 ext4_debug("freeing inode %lu\n", ino); 213 trace_mark(ext4_free_inode, 214 "dev %s ino %lu mode %d uid %lu gid %lu bocks %llu", 215 sb->s_id, inode->i_ino, inode->i_mode, 216 (unsigned long) inode->i_uid, (unsigned long) inode->i_gid, 217 (unsigned long long) inode->i_blocks); 218 219 /* 220 * Note: we must free any quota before locking the superblock, 221 * as writing the quota to disk may need the lock as well. 222 */ 223 DQUOT_INIT(inode); 224 ext4_xattr_delete_inode(handle, inode); 225 DQUOT_FREE_INODE(inode); 226 DQUOT_DROP(inode); 227 228 is_directory = S_ISDIR(inode->i_mode); 229 230 /* Do this BEFORE marking the inode not in use or returning an error */ 231 clear_inode(inode); 232 233 es = EXT4_SB(sb)->s_es; 234 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { 235 ext4_error(sb, "ext4_free_inode", 236 "reserved or nonexistent inode %lu", ino); 237 goto error_return; 238 } 239 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb); 240 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb); 241 bitmap_bh = ext4_read_inode_bitmap(sb, block_group); 242 if (!bitmap_bh) 243 goto error_return; 244 245 BUFFER_TRACE(bitmap_bh, "get_write_access"); 246 fatal = ext4_journal_get_write_access(handle, bitmap_bh); 247 if (fatal) 248 goto error_return; 249 250 /* Ok, now we can actually update the inode bitmaps.. */ 251 spin_lock(sb_bgl_lock(sbi, block_group)); 252 cleared = ext4_clear_bit(bit, bitmap_bh->b_data); 253 spin_unlock(sb_bgl_lock(sbi, block_group)); 254 if (!cleared) 255 ext4_error(sb, "ext4_free_inode", 256 "bit already cleared for inode %lu", ino); 257 else { 258 gdp = ext4_get_group_desc(sb, block_group, &bh2); 259 260 BUFFER_TRACE(bh2, "get_write_access"); 261 fatal = ext4_journal_get_write_access(handle, bh2); 262 if (fatal) goto error_return; 263 264 if (gdp) { 265 spin_lock(sb_bgl_lock(sbi, block_group)); 266 count = ext4_free_inodes_count(sb, gdp) + 1; 267 ext4_free_inodes_set(sb, gdp, count); 268 if (is_directory) { 269 count = ext4_used_dirs_count(sb, gdp) - 1; 270 ext4_used_dirs_set(sb, gdp, count); 271 } 272 gdp->bg_checksum = ext4_group_desc_csum(sbi, 273 block_group, gdp); 274 spin_unlock(sb_bgl_lock(sbi, block_group)); 275 percpu_counter_inc(&sbi->s_freeinodes_counter); 276 if (is_directory) 277 percpu_counter_dec(&sbi->s_dirs_counter); 278 279 if (sbi->s_log_groups_per_flex) { 280 flex_group = ext4_flex_group(sbi, block_group); 281 spin_lock(sb_bgl_lock(sbi, flex_group)); 282 sbi->s_flex_groups[flex_group].free_inodes++; 283 spin_unlock(sb_bgl_lock(sbi, flex_group)); 284 } 285 } 286 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata"); 287 err = ext4_handle_dirty_metadata(handle, NULL, bh2); 288 if (!fatal) fatal = err; 289 } 290 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata"); 291 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); 292 if (!fatal) 293 fatal = err; 294 sb->s_dirt = 1; 295 error_return: 296 brelse(bitmap_bh); 297 ext4_std_error(sb, fatal); 298 } 299 300 /* 301 * There are two policies for allocating an inode. If the new inode is 302 * a directory, then a forward search is made for a block group with both 303 * free space and a low directory-to-inode ratio; if that fails, then of 304 * the groups with above-average free space, that group with the fewest 305 * directories already is chosen. 306 * 307 * For other inodes, search forward from the parent directory\'s block 308 * group to find a free inode. 309 */ 310 static int find_group_dir(struct super_block *sb, struct inode *parent, 311 ext4_group_t *best_group) 312 { 313 ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count; 314 unsigned int freei, avefreei; 315 struct ext4_group_desc *desc, *best_desc = NULL; 316 ext4_group_t group; 317 int ret = -1; 318 319 freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter); 320 avefreei = freei / ngroups; 321 322 for (group = 0; group < ngroups; group++) { 323 desc = ext4_get_group_desc(sb, group, NULL); 324 if (!desc || !ext4_free_inodes_count(sb, desc)) 325 continue; 326 if (ext4_free_inodes_count(sb, desc) < avefreei) 327 continue; 328 if (!best_desc || 329 (ext4_free_blks_count(sb, desc) > 330 ext4_free_blks_count(sb, best_desc))) { 331 *best_group = group; 332 best_desc = desc; 333 ret = 0; 334 } 335 } 336 return ret; 337 } 338 339 #define free_block_ratio 10 340 341 static int find_group_flex(struct super_block *sb, struct inode *parent, 342 ext4_group_t *best_group) 343 { 344 struct ext4_sb_info *sbi = EXT4_SB(sb); 345 struct ext4_group_desc *desc; 346 struct buffer_head *bh; 347 struct flex_groups *flex_group = sbi->s_flex_groups; 348 ext4_group_t parent_group = EXT4_I(parent)->i_block_group; 349 ext4_group_t parent_fbg_group = ext4_flex_group(sbi, parent_group); 350 ext4_group_t ngroups = sbi->s_groups_count; 351 int flex_size = ext4_flex_bg_size(sbi); 352 ext4_group_t best_flex = parent_fbg_group; 353 int blocks_per_flex = sbi->s_blocks_per_group * flex_size; 354 int flexbg_free_blocks; 355 int flex_freeb_ratio; 356 ext4_group_t n_fbg_groups; 357 ext4_group_t i; 358 359 n_fbg_groups = (sbi->s_groups_count + flex_size - 1) >> 360 sbi->s_log_groups_per_flex; 361 362 find_close_to_parent: 363 flexbg_free_blocks = flex_group[best_flex].free_blocks; 364 flex_freeb_ratio = flexbg_free_blocks * 100 / blocks_per_flex; 365 if (flex_group[best_flex].free_inodes && 366 flex_freeb_ratio > free_block_ratio) 367 goto found_flexbg; 368 369 if (best_flex && best_flex == parent_fbg_group) { 370 best_flex--; 371 goto find_close_to_parent; 372 } 373 374 for (i = 0; i < n_fbg_groups; i++) { 375 if (i == parent_fbg_group || i == parent_fbg_group - 1) 376 continue; 377 378 flexbg_free_blocks = flex_group[i].free_blocks; 379 flex_freeb_ratio = flexbg_free_blocks * 100 / blocks_per_flex; 380 381 if (flex_freeb_ratio > free_block_ratio && 382 flex_group[i].free_inodes) { 383 best_flex = i; 384 goto found_flexbg; 385 } 386 387 if (flex_group[best_flex].free_inodes == 0 || 388 (flex_group[i].free_blocks > 389 flex_group[best_flex].free_blocks && 390 flex_group[i].free_inodes)) 391 best_flex = i; 392 } 393 394 if (!flex_group[best_flex].free_inodes || 395 !flex_group[best_flex].free_blocks) 396 return -1; 397 398 found_flexbg: 399 for (i = best_flex * flex_size; i < ngroups && 400 i < (best_flex + 1) * flex_size; i++) { 401 desc = ext4_get_group_desc(sb, i, &bh); 402 if (ext4_free_inodes_count(sb, desc)) { 403 *best_group = i; 404 goto out; 405 } 406 } 407 408 return -1; 409 out: 410 return 0; 411 } 412 413 /* 414 * Orlov's allocator for directories. 415 * 416 * We always try to spread first-level directories. 417 * 418 * If there are blockgroups with both free inodes and free blocks counts 419 * not worse than average we return one with smallest directory count. 420 * Otherwise we simply return a random group. 421 * 422 * For the rest rules look so: 423 * 424 * It's OK to put directory into a group unless 425 * it has too many directories already (max_dirs) or 426 * it has too few free inodes left (min_inodes) or 427 * it has too few free blocks left (min_blocks) or 428 * it's already running too large debt (max_debt). 429 * Parent's group is preferred, if it doesn't satisfy these 430 * conditions we search cyclically through the rest. If none 431 * of the groups look good we just look for a group with more 432 * free inodes than average (starting at parent's group). 433 * 434 * Debt is incremented each time we allocate a directory and decremented 435 * when we allocate an inode, within 0--255. 436 */ 437 438 #define INODE_COST 64 439 #define BLOCK_COST 256 440 441 static int find_group_orlov(struct super_block *sb, struct inode *parent, 442 ext4_group_t *group) 443 { 444 ext4_group_t parent_group = EXT4_I(parent)->i_block_group; 445 struct ext4_sb_info *sbi = EXT4_SB(sb); 446 struct ext4_super_block *es = sbi->s_es; 447 ext4_group_t ngroups = sbi->s_groups_count; 448 int inodes_per_group = EXT4_INODES_PER_GROUP(sb); 449 unsigned int freei, avefreei; 450 ext4_fsblk_t freeb, avefreeb; 451 ext4_fsblk_t blocks_per_dir; 452 unsigned int ndirs; 453 int max_debt, max_dirs, min_inodes; 454 ext4_grpblk_t min_blocks; 455 ext4_group_t i; 456 struct ext4_group_desc *desc; 457 458 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter); 459 avefreei = freei / ngroups; 460 freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter); 461 avefreeb = freeb; 462 do_div(avefreeb, ngroups); 463 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter); 464 465 if ((parent == sb->s_root->d_inode) || 466 (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) { 467 int best_ndir = inodes_per_group; 468 ext4_group_t grp; 469 int ret = -1; 470 471 get_random_bytes(&grp, sizeof(grp)); 472 parent_group = (unsigned)grp % ngroups; 473 for (i = 0; i < ngroups; i++) { 474 grp = (parent_group + i) % ngroups; 475 desc = ext4_get_group_desc(sb, grp, NULL); 476 if (!desc || !ext4_free_inodes_count(sb, desc)) 477 continue; 478 if (ext4_used_dirs_count(sb, desc) >= best_ndir) 479 continue; 480 if (ext4_free_inodes_count(sb, desc) < avefreei) 481 continue; 482 if (ext4_free_blks_count(sb, desc) < avefreeb) 483 continue; 484 *group = grp; 485 ret = 0; 486 best_ndir = ext4_used_dirs_count(sb, desc); 487 } 488 if (ret == 0) 489 return ret; 490 goto fallback; 491 } 492 493 blocks_per_dir = ext4_blocks_count(es) - freeb; 494 do_div(blocks_per_dir, ndirs); 495 496 max_dirs = ndirs / ngroups + inodes_per_group / 16; 497 min_inodes = avefreei - inodes_per_group / 4; 498 min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb) / 4; 499 500 max_debt = EXT4_BLOCKS_PER_GROUP(sb); 501 max_debt /= max_t(int, blocks_per_dir, BLOCK_COST); 502 if (max_debt * INODE_COST > inodes_per_group) 503 max_debt = inodes_per_group / INODE_COST; 504 if (max_debt > 255) 505 max_debt = 255; 506 if (max_debt == 0) 507 max_debt = 1; 508 509 for (i = 0; i < ngroups; i++) { 510 *group = (parent_group + i) % ngroups; 511 desc = ext4_get_group_desc(sb, *group, NULL); 512 if (!desc || !ext4_free_inodes_count(sb, desc)) 513 continue; 514 if (ext4_used_dirs_count(sb, desc) >= max_dirs) 515 continue; 516 if (ext4_free_inodes_count(sb, desc) < min_inodes) 517 continue; 518 if (ext4_free_blks_count(sb, desc) < min_blocks) 519 continue; 520 return 0; 521 } 522 523 fallback: 524 for (i = 0; i < ngroups; i++) { 525 *group = (parent_group + i) % ngroups; 526 desc = ext4_get_group_desc(sb, *group, NULL); 527 if (desc && ext4_free_inodes_count(sb, desc) && 528 ext4_free_inodes_count(sb, desc) >= avefreei) 529 return 0; 530 } 531 532 if (avefreei) { 533 /* 534 * The free-inodes counter is approximate, and for really small 535 * filesystems the above test can fail to find any blockgroups 536 */ 537 avefreei = 0; 538 goto fallback; 539 } 540 541 return -1; 542 } 543 544 static int find_group_other(struct super_block *sb, struct inode *parent, 545 ext4_group_t *group) 546 { 547 ext4_group_t parent_group = EXT4_I(parent)->i_block_group; 548 ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count; 549 struct ext4_group_desc *desc; 550 ext4_group_t i; 551 552 /* 553 * Try to place the inode in its parent directory 554 */ 555 *group = parent_group; 556 desc = ext4_get_group_desc(sb, *group, NULL); 557 if (desc && ext4_free_inodes_count(sb, desc) && 558 ext4_free_blks_count(sb, desc)) 559 return 0; 560 561 /* 562 * We're going to place this inode in a different blockgroup from its 563 * parent. We want to cause files in a common directory to all land in 564 * the same blockgroup. But we want files which are in a different 565 * directory which shares a blockgroup with our parent to land in a 566 * different blockgroup. 567 * 568 * So add our directory's i_ino into the starting point for the hash. 569 */ 570 *group = (*group + parent->i_ino) % ngroups; 571 572 /* 573 * Use a quadratic hash to find a group with a free inode and some free 574 * blocks. 575 */ 576 for (i = 1; i < ngroups; i <<= 1) { 577 *group += i; 578 if (*group >= ngroups) 579 *group -= ngroups; 580 desc = ext4_get_group_desc(sb, *group, NULL); 581 if (desc && ext4_free_inodes_count(sb, desc) && 582 ext4_free_blks_count(sb, desc)) 583 return 0; 584 } 585 586 /* 587 * That failed: try linear search for a free inode, even if that group 588 * has no free blocks. 589 */ 590 *group = parent_group; 591 for (i = 0; i < ngroups; i++) { 592 if (++*group >= ngroups) 593 *group = 0; 594 desc = ext4_get_group_desc(sb, *group, NULL); 595 if (desc && ext4_free_inodes_count(sb, desc)) 596 return 0; 597 } 598 599 return -1; 600 } 601 602 /* 603 * claim the inode from the inode bitmap. If the group 604 * is uninit we need to take the groups's sb_bgl_lock 605 * and clear the uninit flag. The inode bitmap update 606 * and group desc uninit flag clear should be done 607 * after holding sb_bgl_lock so that ext4_read_inode_bitmap 608 * doesn't race with the ext4_claim_inode 609 */ 610 static int ext4_claim_inode(struct super_block *sb, 611 struct buffer_head *inode_bitmap_bh, 612 unsigned long ino, ext4_group_t group, int mode) 613 { 614 int free = 0, retval = 0, count; 615 struct ext4_sb_info *sbi = EXT4_SB(sb); 616 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL); 617 618 spin_lock(sb_bgl_lock(sbi, group)); 619 if (ext4_set_bit(ino, inode_bitmap_bh->b_data)) { 620 /* not a free inode */ 621 retval = 1; 622 goto err_ret; 623 } 624 ino++; 625 if ((group == 0 && ino < EXT4_FIRST_INO(sb)) || 626 ino > EXT4_INODES_PER_GROUP(sb)) { 627 spin_unlock(sb_bgl_lock(sbi, group)); 628 ext4_error(sb, __func__, 629 "reserved inode or inode > inodes count - " 630 "block_group = %u, inode=%lu", group, 631 ino + group * EXT4_INODES_PER_GROUP(sb)); 632 return 1; 633 } 634 /* If we didn't allocate from within the initialized part of the inode 635 * table then we need to initialize up to this inode. */ 636 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { 637 638 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { 639 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT); 640 /* When marking the block group with 641 * ~EXT4_BG_INODE_UNINIT we don't want to depend 642 * on the value of bg_itable_unused even though 643 * mke2fs could have initialized the same for us. 644 * Instead we calculated the value below 645 */ 646 647 free = 0; 648 } else { 649 free = EXT4_INODES_PER_GROUP(sb) - 650 ext4_itable_unused_count(sb, gdp); 651 } 652 653 /* 654 * Check the relative inode number against the last used 655 * relative inode number in this group. if it is greater 656 * we need to update the bg_itable_unused count 657 * 658 */ 659 if (ino > free) 660 ext4_itable_unused_set(sb, gdp, 661 (EXT4_INODES_PER_GROUP(sb) - ino)); 662 } 663 count = ext4_free_inodes_count(sb, gdp) - 1; 664 ext4_free_inodes_set(sb, gdp, count); 665 if (S_ISDIR(mode)) { 666 count = ext4_used_dirs_count(sb, gdp) + 1; 667 ext4_used_dirs_set(sb, gdp, count); 668 } 669 gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp); 670 err_ret: 671 spin_unlock(sb_bgl_lock(sbi, group)); 672 return retval; 673 } 674 675 /* 676 * There are two policies for allocating an inode. If the new inode is 677 * a directory, then a forward search is made for a block group with both 678 * free space and a low directory-to-inode ratio; if that fails, then of 679 * the groups with above-average free space, that group with the fewest 680 * directories already is chosen. 681 * 682 * For other inodes, search forward from the parent directory's block 683 * group to find a free inode. 684 */ 685 struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode) 686 { 687 struct super_block *sb; 688 struct buffer_head *inode_bitmap_bh = NULL; 689 struct buffer_head *group_desc_bh; 690 ext4_group_t group = 0; 691 unsigned long ino = 0; 692 struct inode *inode; 693 struct ext4_group_desc *gdp = NULL; 694 struct ext4_super_block *es; 695 struct ext4_inode_info *ei; 696 struct ext4_sb_info *sbi; 697 int ret2, err = 0; 698 struct inode *ret; 699 ext4_group_t i; 700 int free = 0; 701 ext4_group_t flex_group; 702 703 /* Cannot create files in a deleted directory */ 704 if (!dir || !dir->i_nlink) 705 return ERR_PTR(-EPERM); 706 707 sb = dir->i_sb; 708 trace_mark(ext4_request_inode, "dev %s dir %lu mode %d", sb->s_id, 709 dir->i_ino, mode); 710 inode = new_inode(sb); 711 if (!inode) 712 return ERR_PTR(-ENOMEM); 713 ei = EXT4_I(inode); 714 715 sbi = EXT4_SB(sb); 716 es = sbi->s_es; 717 718 if (sbi->s_log_groups_per_flex) { 719 ret2 = find_group_flex(sb, dir, &group); 720 if (ret2 == -1) { 721 ret2 = find_group_other(sb, dir, &group); 722 if (ret2 == 0 && printk_ratelimit()) 723 printk(KERN_NOTICE "ext4: find_group_flex " 724 "failed, fallback succeeded dir %lu\n", 725 dir->i_ino); 726 } 727 goto got_group; 728 } 729 730 if (S_ISDIR(mode)) { 731 if (test_opt(sb, OLDALLOC)) 732 ret2 = find_group_dir(sb, dir, &group); 733 else 734 ret2 = find_group_orlov(sb, dir, &group); 735 } else 736 ret2 = find_group_other(sb, dir, &group); 737 738 got_group: 739 err = -ENOSPC; 740 if (ret2 == -1) 741 goto out; 742 743 for (i = 0; i < sbi->s_groups_count; i++) { 744 err = -EIO; 745 746 gdp = ext4_get_group_desc(sb, group, &group_desc_bh); 747 if (!gdp) 748 goto fail; 749 750 brelse(inode_bitmap_bh); 751 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group); 752 if (!inode_bitmap_bh) 753 goto fail; 754 755 ino = 0; 756 757 repeat_in_this_group: 758 ino = ext4_find_next_zero_bit((unsigned long *) 759 inode_bitmap_bh->b_data, 760 EXT4_INODES_PER_GROUP(sb), ino); 761 762 if (ino < EXT4_INODES_PER_GROUP(sb)) { 763 764 BUFFER_TRACE(inode_bitmap_bh, "get_write_access"); 765 err = ext4_journal_get_write_access(handle, 766 inode_bitmap_bh); 767 if (err) 768 goto fail; 769 770 BUFFER_TRACE(group_desc_bh, "get_write_access"); 771 err = ext4_journal_get_write_access(handle, 772 group_desc_bh); 773 if (err) 774 goto fail; 775 if (!ext4_claim_inode(sb, inode_bitmap_bh, 776 ino, group, mode)) { 777 /* we won it */ 778 BUFFER_TRACE(inode_bitmap_bh, 779 "call ext4_handle_dirty_metadata"); 780 err = ext4_handle_dirty_metadata(handle, 781 inode, 782 inode_bitmap_bh); 783 if (err) 784 goto fail; 785 /* zero bit is inode number 1*/ 786 ino++; 787 goto got; 788 } 789 /* we lost it */ 790 ext4_handle_release_buffer(handle, inode_bitmap_bh); 791 ext4_handle_release_buffer(handle, group_desc_bh); 792 793 if (++ino < EXT4_INODES_PER_GROUP(sb)) 794 goto repeat_in_this_group; 795 } 796 797 /* 798 * This case is possible in concurrent environment. It is very 799 * rare. We cannot repeat the find_group_xxx() call because 800 * that will simply return the same blockgroup, because the 801 * group descriptor metadata has not yet been updated. 802 * So we just go onto the next blockgroup. 803 */ 804 if (++group == sbi->s_groups_count) 805 group = 0; 806 } 807 err = -ENOSPC; 808 goto out; 809 810 got: 811 /* We may have to initialize the block bitmap if it isn't already */ 812 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) && 813 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { 814 struct buffer_head *block_bitmap_bh; 815 816 block_bitmap_bh = ext4_read_block_bitmap(sb, group); 817 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access"); 818 err = ext4_journal_get_write_access(handle, block_bitmap_bh); 819 if (err) { 820 brelse(block_bitmap_bh); 821 goto fail; 822 } 823 824 free = 0; 825 spin_lock(sb_bgl_lock(sbi, group)); 826 /* recheck and clear flag under lock if we still need to */ 827 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { 828 free = ext4_free_blocks_after_init(sb, group, gdp); 829 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); 830 ext4_free_blks_set(sb, gdp, free); 831 gdp->bg_checksum = ext4_group_desc_csum(sbi, group, 832 gdp); 833 } 834 spin_unlock(sb_bgl_lock(sbi, group)); 835 836 /* Don't need to dirty bitmap block if we didn't change it */ 837 if (free) { 838 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap"); 839 err = ext4_handle_dirty_metadata(handle, 840 NULL, block_bitmap_bh); 841 } 842 843 brelse(block_bitmap_bh); 844 if (err) 845 goto fail; 846 } 847 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata"); 848 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh); 849 if (err) 850 goto fail; 851 852 percpu_counter_dec(&sbi->s_freeinodes_counter); 853 if (S_ISDIR(mode)) 854 percpu_counter_inc(&sbi->s_dirs_counter); 855 sb->s_dirt = 1; 856 857 if (sbi->s_log_groups_per_flex) { 858 flex_group = ext4_flex_group(sbi, group); 859 spin_lock(sb_bgl_lock(sbi, flex_group)); 860 sbi->s_flex_groups[flex_group].free_inodes--; 861 spin_unlock(sb_bgl_lock(sbi, flex_group)); 862 } 863 864 inode->i_uid = current_fsuid(); 865 if (test_opt(sb, GRPID)) 866 inode->i_gid = dir->i_gid; 867 else if (dir->i_mode & S_ISGID) { 868 inode->i_gid = dir->i_gid; 869 if (S_ISDIR(mode)) 870 mode |= S_ISGID; 871 } else 872 inode->i_gid = current_fsgid(); 873 inode->i_mode = mode; 874 875 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb); 876 /* This is the optimal IO size (for stat), not the fs block size */ 877 inode->i_blocks = 0; 878 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime = 879 ext4_current_time(inode); 880 881 memset(ei->i_data, 0, sizeof(ei->i_data)); 882 ei->i_dir_start_lookup = 0; 883 ei->i_disksize = 0; 884 885 /* 886 * Don't inherit extent flag from directory. We set extent flag on 887 * newly created directory and file only if -o extent mount option is 888 * specified 889 */ 890 ei->i_flags = EXT4_I(dir)->i_flags & ~(EXT4_INDEX_FL|EXT4_EXTENTS_FL); 891 if (S_ISLNK(mode)) 892 ei->i_flags &= ~(EXT4_IMMUTABLE_FL|EXT4_APPEND_FL); 893 /* dirsync only applies to directories */ 894 if (!S_ISDIR(mode)) 895 ei->i_flags &= ~EXT4_DIRSYNC_FL; 896 ei->i_file_acl = 0; 897 ei->i_dtime = 0; 898 ei->i_block_group = group; 899 900 ext4_set_inode_flags(inode); 901 if (IS_DIRSYNC(inode)) 902 ext4_handle_sync(handle); 903 if (insert_inode_locked(inode) < 0) { 904 err = -EINVAL; 905 goto fail_drop; 906 } 907 spin_lock(&sbi->s_next_gen_lock); 908 inode->i_generation = sbi->s_next_generation++; 909 spin_unlock(&sbi->s_next_gen_lock); 910 911 ei->i_state = EXT4_STATE_NEW; 912 913 ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize; 914 915 ret = inode; 916 if (DQUOT_ALLOC_INODE(inode)) { 917 err = -EDQUOT; 918 goto fail_drop; 919 } 920 921 err = ext4_init_acl(handle, inode, dir); 922 if (err) 923 goto fail_free_drop; 924 925 err = ext4_init_security(handle, inode, dir); 926 if (err) 927 goto fail_free_drop; 928 929 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) { 930 /* set extent flag only for directory, file and normal symlink*/ 931 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) { 932 EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL; 933 ext4_ext_tree_init(handle, inode); 934 } 935 } 936 937 err = ext4_mark_inode_dirty(handle, inode); 938 if (err) { 939 ext4_std_error(sb, err); 940 goto fail_free_drop; 941 } 942 943 ext4_debug("allocating inode %lu\n", inode->i_ino); 944 trace_mark(ext4_allocate_inode, "dev %s ino %lu dir %lu mode %d", 945 sb->s_id, inode->i_ino, dir->i_ino, mode); 946 goto really_out; 947 fail: 948 ext4_std_error(sb, err); 949 out: 950 iput(inode); 951 ret = ERR_PTR(err); 952 really_out: 953 brelse(inode_bitmap_bh); 954 return ret; 955 956 fail_free_drop: 957 DQUOT_FREE_INODE(inode); 958 959 fail_drop: 960 DQUOT_DROP(inode); 961 inode->i_flags |= S_NOQUOTA; 962 inode->i_nlink = 0; 963 unlock_new_inode(inode); 964 iput(inode); 965 brelse(inode_bitmap_bh); 966 return ERR_PTR(err); 967 } 968 969 /* Verify that we are loading a valid orphan from disk */ 970 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino) 971 { 972 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count); 973 ext4_group_t block_group; 974 int bit; 975 struct buffer_head *bitmap_bh; 976 struct inode *inode = NULL; 977 long err = -EIO; 978 979 /* Error cases - e2fsck has already cleaned up for us */ 980 if (ino > max_ino) { 981 ext4_warning(sb, __func__, 982 "bad orphan ino %lu! e2fsck was run?", ino); 983 goto error; 984 } 985 986 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb); 987 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb); 988 bitmap_bh = ext4_read_inode_bitmap(sb, block_group); 989 if (!bitmap_bh) { 990 ext4_warning(sb, __func__, 991 "inode bitmap error for orphan %lu", ino); 992 goto error; 993 } 994 995 /* Having the inode bit set should be a 100% indicator that this 996 * is a valid orphan (no e2fsck run on fs). Orphans also include 997 * inodes that were being truncated, so we can't check i_nlink==0. 998 */ 999 if (!ext4_test_bit(bit, bitmap_bh->b_data)) 1000 goto bad_orphan; 1001 1002 inode = ext4_iget(sb, ino); 1003 if (IS_ERR(inode)) 1004 goto iget_failed; 1005 1006 /* 1007 * If the orphans has i_nlinks > 0 then it should be able to be 1008 * truncated, otherwise it won't be removed from the orphan list 1009 * during processing and an infinite loop will result. 1010 */ 1011 if (inode->i_nlink && !ext4_can_truncate(inode)) 1012 goto bad_orphan; 1013 1014 if (NEXT_ORPHAN(inode) > max_ino) 1015 goto bad_orphan; 1016 brelse(bitmap_bh); 1017 return inode; 1018 1019 iget_failed: 1020 err = PTR_ERR(inode); 1021 inode = NULL; 1022 bad_orphan: 1023 ext4_warning(sb, __func__, 1024 "bad orphan inode %lu! e2fsck was run?", ino); 1025 printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n", 1026 bit, (unsigned long long)bitmap_bh->b_blocknr, 1027 ext4_test_bit(bit, bitmap_bh->b_data)); 1028 printk(KERN_NOTICE "inode=%p\n", inode); 1029 if (inode) { 1030 printk(KERN_NOTICE "is_bad_inode(inode)=%d\n", 1031 is_bad_inode(inode)); 1032 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n", 1033 NEXT_ORPHAN(inode)); 1034 printk(KERN_NOTICE "max_ino=%lu\n", max_ino); 1035 printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink); 1036 /* Avoid freeing blocks if we got a bad deleted inode */ 1037 if (inode->i_nlink == 0) 1038 inode->i_blocks = 0; 1039 iput(inode); 1040 } 1041 brelse(bitmap_bh); 1042 error: 1043 return ERR_PTR(err); 1044 } 1045 1046 unsigned long ext4_count_free_inodes(struct super_block *sb) 1047 { 1048 unsigned long desc_count; 1049 struct ext4_group_desc *gdp; 1050 ext4_group_t i; 1051 #ifdef EXT4FS_DEBUG 1052 struct ext4_super_block *es; 1053 unsigned long bitmap_count, x; 1054 struct buffer_head *bitmap_bh = NULL; 1055 1056 es = EXT4_SB(sb)->s_es; 1057 desc_count = 0; 1058 bitmap_count = 0; 1059 gdp = NULL; 1060 for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) { 1061 gdp = ext4_get_group_desc(sb, i, NULL); 1062 if (!gdp) 1063 continue; 1064 desc_count += ext4_free_inodes_count(sb, gdp); 1065 brelse(bitmap_bh); 1066 bitmap_bh = ext4_read_inode_bitmap(sb, i); 1067 if (!bitmap_bh) 1068 continue; 1069 1070 x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8); 1071 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n", 1072 i, ext4_free_inodes_count(sb, gdp), x); 1073 bitmap_count += x; 1074 } 1075 brelse(bitmap_bh); 1076 printk(KERN_DEBUG "ext4_count_free_inodes: " 1077 "stored = %u, computed = %lu, %lu\n", 1078 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count); 1079 return desc_count; 1080 #else 1081 desc_count = 0; 1082 for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) { 1083 gdp = ext4_get_group_desc(sb, i, NULL); 1084 if (!gdp) 1085 continue; 1086 desc_count += ext4_free_inodes_count(sb, gdp); 1087 cond_resched(); 1088 } 1089 return desc_count; 1090 #endif 1091 } 1092 1093 /* Called at mount-time, super-block is locked */ 1094 unsigned long ext4_count_dirs(struct super_block * sb) 1095 { 1096 unsigned long count = 0; 1097 ext4_group_t i; 1098 1099 for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) { 1100 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL); 1101 if (!gdp) 1102 continue; 1103 count += ext4_used_dirs_count(sb, gdp); 1104 } 1105 return count; 1106 } 1107