1/* 2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com 3 * Written by Alex Tomas <alex@clusterfs.com> 4 * 5 * Architecture independence: 6 * Copyright (c) 2005, Bull S.A. 7 * Written by Pierre Peiffer <pierre.peiffer@bull.net> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public Licens 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- 21 */ 22 23/* 24 * Extents support for EXT4 25 * 26 * TODO: 27 * - ext4*_error() should be used in some situations 28 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate 29 * - smart tree reduction 30 */ 31 32#include <linux/module.h> 33#include <linux/fs.h> 34#include <linux/time.h> 35#include <linux/jbd2.h> 36#include <linux/highuid.h> 37#include <linux/pagemap.h> 38#include <linux/quotaops.h> 39#include <linux/string.h> 40#include <linux/slab.h> 41#include <linux/falloc.h> 42#include <asm/uaccess.h> 43#include <linux/fiemap.h> 44#include "ext4_jbd2.h" 45#include "ext4_extents.h" 46 47 48/* 49 * ext_pblock: 50 * combine low and high parts of physical block number into ext4_fsblk_t 51 */ 52ext4_fsblk_t ext_pblock(struct ext4_extent *ex) 53{ 54 ext4_fsblk_t block; 55 56 block = le32_to_cpu(ex->ee_start_lo); 57 block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1; 58 return block; 59} 60 61/* 62 * idx_pblock: 63 * combine low and high parts of a leaf physical block number into ext4_fsblk_t 64 */ 65ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix) 66{ 67 ext4_fsblk_t block; 68 69 block = le32_to_cpu(ix->ei_leaf_lo); 70 block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1; 71 return block; 72} 73 74/* 75 * ext4_ext_store_pblock: 76 * stores a large physical block number into an extent struct, 77 * breaking it into parts 78 */ 79void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb) 80{ 81 ex->ee_start_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff)); 82 ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); 83} 84 85/* 86 * ext4_idx_store_pblock: 87 * stores a large physical block number into an index struct, 88 * breaking it into parts 89 */ 90static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb) 91{ 92 ix->ei_leaf_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff)); 93 ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); 94} 95 96static int ext4_ext_truncate_extend_restart(handle_t *handle, 97 struct inode *inode, 98 int needed) 99{ 100 int err; 101 102 if (!ext4_handle_valid(handle)) 103 return 0; 104 if (handle->h_buffer_credits > needed) 105 return 0; 106 err = ext4_journal_extend(handle, needed); 107 if (err <= 0) 108 return err; 109 err = ext4_truncate_restart_trans(handle, inode, needed); 110 if (err == 0) 111 err = -EAGAIN; 112 113 return err; 114} 115 116/* 117 * could return: 118 * - EROFS 119 * - ENOMEM 120 */ 121static int ext4_ext_get_access(handle_t *handle, struct inode *inode, 122 struct ext4_ext_path *path) 123{ 124 if (path->p_bh) { 125 /* path points to block */ 126 return ext4_journal_get_write_access(handle, path->p_bh); 127 } 128 /* path points to leaf/index in inode body */ 129 /* we use in-core data, no need to protect them */ 130 return 0; 131} 132 133/* 134 * could return: 135 * - EROFS 136 * - ENOMEM 137 * - EIO 138 */ 139static int ext4_ext_dirty(handle_t *handle, struct inode *inode, 140 struct ext4_ext_path *path) 141{ 142 int err; 143 if (path->p_bh) { 144 /* path points to block */ 145 err = ext4_handle_dirty_metadata(handle, inode, path->p_bh); 146 } else { 147 /* path points to leaf/index in inode body */ 148 err = ext4_mark_inode_dirty(handle, inode); 149 } 150 return err; 151} 152 153static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, 154 struct ext4_ext_path *path, 155 ext4_lblk_t block) 156{ 157 struct ext4_inode_info *ei = EXT4_I(inode); 158 ext4_fsblk_t bg_start; 159 ext4_fsblk_t last_block; 160 ext4_grpblk_t colour; 161 ext4_group_t block_group; 162 int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb)); 163 int depth; 164 165 if (path) { 166 struct ext4_extent *ex; 167 depth = path->p_depth; 168 169 /* try to predict block placement */ 170 ex = path[depth].p_ext; 171 if (ex) 172 return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block)); 173 174 /* it looks like index is empty; 175 * try to find starting block from index itself */ 176 if (path[depth].p_bh) 177 return path[depth].p_bh->b_blocknr; 178 } 179 180 /* OK. use inode's group */ 181 block_group = ei->i_block_group; 182 if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) { 183 /* 184 * If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 185 * block groups per flexgroup, reserve the first block 186 * group for directories and special files. Regular 187 * files will start at the second block group. This 188 * tends to speed up directory access and improves 189 * fsck times. 190 */ 191 block_group &= ~(flex_size-1); 192 if (S_ISREG(inode->i_mode)) 193 block_group++; 194 } 195 bg_start = ext4_group_first_block_no(inode->i_sb, block_group); 196 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1; 197 198 /* 199 * If we are doing delayed allocation, we don't need take 200 * colour into account. 201 */ 202 if (test_opt(inode->i_sb, DELALLOC)) 203 return bg_start; 204 205 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block) 206 colour = (current->pid % 16) * 207 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); 208 else 209 colour = (current->pid % 16) * ((last_block - bg_start) / 16); 210 return bg_start + colour + block; 211} 212 213/* 214 * Allocation for a meta data block 215 */ 216static ext4_fsblk_t 217ext4_ext_new_meta_block(handle_t *handle, struct inode *inode, 218 struct ext4_ext_path *path, 219 struct ext4_extent *ex, int *err) 220{ 221 ext4_fsblk_t goal, newblock; 222 223 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); 224 newblock = ext4_new_meta_blocks(handle, inode, goal, NULL, err); 225 return newblock; 226} 227 228static inline int ext4_ext_space_block(struct inode *inode, int check) 229{ 230 int size; 231 232 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 233 / sizeof(struct ext4_extent); 234 if (!check) { 235#ifdef AGGRESSIVE_TEST 236 if (size > 6) 237 size = 6; 238#endif 239 } 240 return size; 241} 242 243static inline int ext4_ext_space_block_idx(struct inode *inode, int check) 244{ 245 int size; 246 247 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 248 / sizeof(struct ext4_extent_idx); 249 if (!check) { 250#ifdef AGGRESSIVE_TEST 251 if (size > 5) 252 size = 5; 253#endif 254 } 255 return size; 256} 257 258static inline int ext4_ext_space_root(struct inode *inode, int check) 259{ 260 int size; 261 262 size = sizeof(EXT4_I(inode)->i_data); 263 size -= sizeof(struct ext4_extent_header); 264 size /= sizeof(struct ext4_extent); 265 if (!check) { 266#ifdef AGGRESSIVE_TEST 267 if (size > 3) 268 size = 3; 269#endif 270 } 271 return size; 272} 273 274static inline int ext4_ext_space_root_idx(struct inode *inode, int check) 275{ 276 int size; 277 278 size = sizeof(EXT4_I(inode)->i_data); 279 size -= sizeof(struct ext4_extent_header); 280 size /= sizeof(struct ext4_extent_idx); 281 if (!check) { 282#ifdef AGGRESSIVE_TEST 283 if (size > 4) 284 size = 4; 285#endif 286 } 287 return size; 288} 289 290/* 291 * Calculate the number of metadata blocks needed 292 * to allocate @blocks 293 * Worse case is one block per extent 294 */ 295int ext4_ext_calc_metadata_amount(struct inode *inode, sector_t lblock) 296{ 297 struct ext4_inode_info *ei = EXT4_I(inode); 298 int idxs, num = 0; 299 300 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 301 / sizeof(struct ext4_extent_idx)); 302 303 /* 304 * If the new delayed allocation block is contiguous with the 305 * previous da block, it can share index blocks with the 306 * previous block, so we only need to allocate a new index 307 * block every idxs leaf blocks. At ldxs**2 blocks, we need 308 * an additional index block, and at ldxs**3 blocks, yet 309 * another index blocks. 310 */ 311 if (ei->i_da_metadata_calc_len && 312 ei->i_da_metadata_calc_last_lblock+1 == lblock) { 313 if ((ei->i_da_metadata_calc_len % idxs) == 0) 314 num++; 315 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0) 316 num++; 317 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) { 318 num++; 319 ei->i_da_metadata_calc_len = 0; 320 } else 321 ei->i_da_metadata_calc_len++; 322 ei->i_da_metadata_calc_last_lblock++; 323 return num; 324 } 325 326 /* 327 * In the worst case we need a new set of index blocks at 328 * every level of the inode's extent tree. 329 */ 330 ei->i_da_metadata_calc_len = 1; 331 ei->i_da_metadata_calc_last_lblock = lblock; 332 return ext_depth(inode) + 1; 333} 334 335static int 336ext4_ext_max_entries(struct inode *inode, int depth) 337{ 338 int max; 339 340 if (depth == ext_depth(inode)) { 341 if (depth == 0) 342 max = ext4_ext_space_root(inode, 1); 343 else 344 max = ext4_ext_space_root_idx(inode, 1); 345 } else { 346 if (depth == 0) 347 max = ext4_ext_space_block(inode, 1); 348 else 349 max = ext4_ext_space_block_idx(inode, 1); 350 } 351 352 return max; 353} 354 355static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) 356{ 357 ext4_fsblk_t block = ext_pblock(ext); 358 int len = ext4_ext_get_actual_len(ext); 359 360 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); 361} 362 363static int ext4_valid_extent_idx(struct inode *inode, 364 struct ext4_extent_idx *ext_idx) 365{ 366 ext4_fsblk_t block = idx_pblock(ext_idx); 367 368 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1); 369} 370 371static int ext4_valid_extent_entries(struct inode *inode, 372 struct ext4_extent_header *eh, 373 int depth) 374{ 375 struct ext4_extent *ext; 376 struct ext4_extent_idx *ext_idx; 377 unsigned short entries; 378 if (eh->eh_entries == 0) 379 return 1; 380 381 entries = le16_to_cpu(eh->eh_entries); 382 383 if (depth == 0) { 384 /* leaf entries */ 385 ext = EXT_FIRST_EXTENT(eh); 386 while (entries) { 387 if (!ext4_valid_extent(inode, ext)) 388 return 0; 389 ext++; 390 entries--; 391 } 392 } else { 393 ext_idx = EXT_FIRST_INDEX(eh); 394 while (entries) { 395 if (!ext4_valid_extent_idx(inode, ext_idx)) 396 return 0; 397 ext_idx++; 398 entries--; 399 } 400 } 401 return 1; 402} 403 404static int __ext4_ext_check(const char *function, unsigned int line, 405 struct inode *inode, struct ext4_extent_header *eh, 406 int depth) 407{ 408 const char *error_msg; 409 int max = 0; 410 411 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { 412 error_msg = "invalid magic"; 413 goto corrupted; 414 } 415 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { 416 error_msg = "unexpected eh_depth"; 417 goto corrupted; 418 } 419 if (unlikely(eh->eh_max == 0)) { 420 error_msg = "invalid eh_max"; 421 goto corrupted; 422 } 423 max = ext4_ext_max_entries(inode, depth); 424 if (unlikely(le16_to_cpu(eh->eh_max) > max)) { 425 error_msg = "too large eh_max"; 426 goto corrupted; 427 } 428 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { 429 error_msg = "invalid eh_entries"; 430 goto corrupted; 431 } 432 if (!ext4_valid_extent_entries(inode, eh, depth)) { 433 error_msg = "invalid extent entries"; 434 goto corrupted; 435 } 436 return 0; 437 438corrupted: 439 ext4_error_inode(inode, function, line, 0, 440 "bad header/extent: %s - magic %x, " 441 "entries %u, max %u(%u), depth %u(%u)", 442 error_msg, le16_to_cpu(eh->eh_magic), 443 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), 444 max, le16_to_cpu(eh->eh_depth), depth); 445 446 return -EIO; 447} 448 449#define ext4_ext_check(inode, eh, depth) \ 450 __ext4_ext_check(__func__, __LINE__, inode, eh, depth) 451 452int ext4_ext_check_inode(struct inode *inode) 453{ 454 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode)); 455} 456 457#ifdef EXT_DEBUG 458static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) 459{ 460 int k, l = path->p_depth; 461 462 ext_debug("path:"); 463 for (k = 0; k <= l; k++, path++) { 464 if (path->p_idx) { 465 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), 466 idx_pblock(path->p_idx)); 467 } else if (path->p_ext) { 468 ext_debug(" %d:[%d]%d:%llu ", 469 le32_to_cpu(path->p_ext->ee_block), 470 ext4_ext_is_uninitialized(path->p_ext), 471 ext4_ext_get_actual_len(path->p_ext), 472 ext_pblock(path->p_ext)); 473 } else 474 ext_debug(" []"); 475 } 476 ext_debug("\n"); 477} 478 479static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) 480{ 481 int depth = ext_depth(inode); 482 struct ext4_extent_header *eh; 483 struct ext4_extent *ex; 484 int i; 485 486 if (!path) 487 return; 488 489 eh = path[depth].p_hdr; 490 ex = EXT_FIRST_EXTENT(eh); 491 492 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino); 493 494 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { 495 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block), 496 ext4_ext_is_uninitialized(ex), 497 ext4_ext_get_actual_len(ex), ext_pblock(ex)); 498 } 499 ext_debug("\n"); 500} 501#else 502#define ext4_ext_show_path(inode, path) 503#define ext4_ext_show_leaf(inode, path) 504#endif 505 506void ext4_ext_drop_refs(struct ext4_ext_path *path) 507{ 508 int depth = path->p_depth; 509 int i; 510 511 for (i = 0; i <= depth; i++, path++) 512 if (path->p_bh) { 513 brelse(path->p_bh); 514 path->p_bh = NULL; 515 } 516} 517 518/* 519 * ext4_ext_binsearch_idx: 520 * binary search for the closest index of the given block 521 * the header must be checked before calling this 522 */ 523static void 524ext4_ext_binsearch_idx(struct inode *inode, 525 struct ext4_ext_path *path, ext4_lblk_t block) 526{ 527 struct ext4_extent_header *eh = path->p_hdr; 528 struct ext4_extent_idx *r, *l, *m; 529 530 531 ext_debug("binsearch for %u(idx): ", block); 532 533 l = EXT_FIRST_INDEX(eh) + 1; 534 r = EXT_LAST_INDEX(eh); 535 while (l <= r) { 536 m = l + (r - l) / 2; 537 if (block < le32_to_cpu(m->ei_block)) 538 r = m - 1; 539 else 540 l = m + 1; 541 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), 542 m, le32_to_cpu(m->ei_block), 543 r, le32_to_cpu(r->ei_block)); 544 } 545 546 path->p_idx = l - 1; 547 ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block), 548 idx_pblock(path->p_idx)); 549 550#ifdef CHECK_BINSEARCH 551 { 552 struct ext4_extent_idx *chix, *ix; 553 int k; 554 555 chix = ix = EXT_FIRST_INDEX(eh); 556 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { 557 if (k != 0 && 558 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { 559 printk(KERN_DEBUG "k=%d, ix=0x%p, " 560 "first=0x%p\n", k, 561 ix, EXT_FIRST_INDEX(eh)); 562 printk(KERN_DEBUG "%u <= %u\n", 563 le32_to_cpu(ix->ei_block), 564 le32_to_cpu(ix[-1].ei_block)); 565 } 566 BUG_ON(k && le32_to_cpu(ix->ei_block) 567 <= le32_to_cpu(ix[-1].ei_block)); 568 if (block < le32_to_cpu(ix->ei_block)) 569 break; 570 chix = ix; 571 } 572 BUG_ON(chix != path->p_idx); 573 } 574#endif 575 576} 577 578/* 579 * ext4_ext_binsearch: 580 * binary search for closest extent of the given block 581 * the header must be checked before calling this 582 */ 583static void 584ext4_ext_binsearch(struct inode *inode, 585 struct ext4_ext_path *path, ext4_lblk_t block) 586{ 587 struct ext4_extent_header *eh = path->p_hdr; 588 struct ext4_extent *r, *l, *m; 589 590 if (eh->eh_entries == 0) { 591 /* 592 * this leaf is empty: 593 * we get such a leaf in split/add case 594 */ 595 return; 596 } 597 598 ext_debug("binsearch for %u: ", block); 599 600 l = EXT_FIRST_EXTENT(eh) + 1; 601 r = EXT_LAST_EXTENT(eh); 602 603 while (l <= r) { 604 m = l + (r - l) / 2; 605 if (block < le32_to_cpu(m->ee_block)) 606 r = m - 1; 607 else 608 l = m + 1; 609 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), 610 m, le32_to_cpu(m->ee_block), 611 r, le32_to_cpu(r->ee_block)); 612 } 613 614 path->p_ext = l - 1; 615 ext_debug(" -> %d:%llu:[%d]%d ", 616 le32_to_cpu(path->p_ext->ee_block), 617 ext_pblock(path->p_ext), 618 ext4_ext_is_uninitialized(path->p_ext), 619 ext4_ext_get_actual_len(path->p_ext)); 620 621#ifdef CHECK_BINSEARCH 622 { 623 struct ext4_extent *chex, *ex; 624 int k; 625 626 chex = ex = EXT_FIRST_EXTENT(eh); 627 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { 628 BUG_ON(k && le32_to_cpu(ex->ee_block) 629 <= le32_to_cpu(ex[-1].ee_block)); 630 if (block < le32_to_cpu(ex->ee_block)) 631 break; 632 chex = ex; 633 } 634 BUG_ON(chex != path->p_ext); 635 } 636#endif 637 638} 639 640int ext4_ext_tree_init(handle_t *handle, struct inode *inode) 641{ 642 struct ext4_extent_header *eh; 643 644 eh = ext_inode_hdr(inode); 645 eh->eh_depth = 0; 646 eh->eh_entries = 0; 647 eh->eh_magic = EXT4_EXT_MAGIC; 648 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); 649 ext4_mark_inode_dirty(handle, inode); 650 ext4_ext_invalidate_cache(inode); 651 return 0; 652} 653 654struct ext4_ext_path * 655ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, 656 struct ext4_ext_path *path) 657{ 658 struct ext4_extent_header *eh; 659 struct buffer_head *bh; 660 short int depth, i, ppos = 0, alloc = 0; 661 662 eh = ext_inode_hdr(inode); 663 depth = ext_depth(inode); 664 665 /* account possible depth increase */ 666 if (!path) { 667 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2), 668 GFP_NOFS); 669 if (!path) 670 return ERR_PTR(-ENOMEM); 671 alloc = 1; 672 } 673 path[0].p_hdr = eh; 674 path[0].p_bh = NULL; 675 676 i = depth; 677 /* walk through the tree */ 678 while (i) { 679 int need_to_validate = 0; 680 681 ext_debug("depth %d: num %d, max %d\n", 682 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); 683 684 ext4_ext_binsearch_idx(inode, path + ppos, block); 685 path[ppos].p_block = idx_pblock(path[ppos].p_idx); 686 path[ppos].p_depth = i; 687 path[ppos].p_ext = NULL; 688 689 bh = sb_getblk(inode->i_sb, path[ppos].p_block); 690 if (unlikely(!bh)) 691 goto err; 692 if (!bh_uptodate_or_lock(bh)) { 693 if (bh_submit_read(bh) < 0) { 694 put_bh(bh); 695 goto err; 696 } 697 /* validate the extent entries */ 698 need_to_validate = 1; 699 } 700 eh = ext_block_hdr(bh); 701 ppos++; 702 if (unlikely(ppos > depth)) { 703 put_bh(bh); 704 EXT4_ERROR_INODE(inode, 705 "ppos %d > depth %d", ppos, depth); 706 goto err; 707 } 708 path[ppos].p_bh = bh; 709 path[ppos].p_hdr = eh; 710 i--; 711 712 if (need_to_validate && ext4_ext_check(inode, eh, i)) 713 goto err; 714 } 715 716 path[ppos].p_depth = i; 717 path[ppos].p_ext = NULL; 718 path[ppos].p_idx = NULL; 719 720 /* find extent */ 721 ext4_ext_binsearch(inode, path + ppos, block); 722 /* if not an empty leaf */ 723 if (path[ppos].p_ext) 724 path[ppos].p_block = ext_pblock(path[ppos].p_ext); 725 726 ext4_ext_show_path(inode, path); 727 728 return path; 729 730err: 731 ext4_ext_drop_refs(path); 732 if (alloc) 733 kfree(path); 734 return ERR_PTR(-EIO); 735} 736 737/* 738 * ext4_ext_insert_index: 739 * insert new index [@logical;@ptr] into the block at @curp; 740 * check where to insert: before @curp or after @curp 741 */ 742int ext4_ext_insert_index(handle_t *handle, struct inode *inode, 743 struct ext4_ext_path *curp, 744 int logical, ext4_fsblk_t ptr) 745{ 746 struct ext4_extent_idx *ix; 747 int len, err; 748 749 err = ext4_ext_get_access(handle, inode, curp); 750 if (err) 751 return err; 752 753 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) { 754 EXT4_ERROR_INODE(inode, 755 "logical %d == ei_block %d!", 756 logical, le32_to_cpu(curp->p_idx->ei_block)); 757 return -EIO; 758 } 759 len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx; 760 if (logical > le32_to_cpu(curp->p_idx->ei_block)) { 761 /* insert after */ 762 if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) { 763 len = (len - 1) * sizeof(struct ext4_extent_idx); 764 len = len < 0 ? 0 : len; 765 ext_debug("insert new index %d after: %llu. " 766 "move %d from 0x%p to 0x%p\n", 767 logical, ptr, len, 768 (curp->p_idx + 1), (curp->p_idx + 2)); 769 memmove(curp->p_idx + 2, curp->p_idx + 1, len); 770 } 771 ix = curp->p_idx + 1; 772 } else { 773 /* insert before */ 774 len = len * sizeof(struct ext4_extent_idx); 775 len = len < 0 ? 0 : len; 776 ext_debug("insert new index %d before: %llu. " 777 "move %d from 0x%p to 0x%p\n", 778 logical, ptr, len, 779 curp->p_idx, (curp->p_idx + 1)); 780 memmove(curp->p_idx + 1, curp->p_idx, len); 781 ix = curp->p_idx; 782 } 783 784 ix->ei_block = cpu_to_le32(logical); 785 ext4_idx_store_pblock(ix, ptr); 786 le16_add_cpu(&curp->p_hdr->eh_entries, 1); 787 788 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) 789 > le16_to_cpu(curp->p_hdr->eh_max))) { 790 EXT4_ERROR_INODE(inode, 791 "logical %d == ei_block %d!", 792 logical, le32_to_cpu(curp->p_idx->ei_block)); 793 return -EIO; 794 } 795 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) { 796 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!"); 797 return -EIO; 798 } 799 800 err = ext4_ext_dirty(handle, inode, curp); 801 ext4_std_error(inode->i_sb, err); 802 803 return err; 804} 805 806/* 807 * ext4_ext_split: 808 * inserts new subtree into the path, using free index entry 809 * at depth @at: 810 * - allocates all needed blocks (new leaf and all intermediate index blocks) 811 * - makes decision where to split 812 * - moves remaining extents and index entries (right to the split point) 813 * into the newly allocated blocks 814 * - initializes subtree 815 */ 816static int ext4_ext_split(handle_t *handle, struct inode *inode, 817 struct ext4_ext_path *path, 818 struct ext4_extent *newext, int at) 819{ 820 struct buffer_head *bh = NULL; 821 int depth = ext_depth(inode); 822 struct ext4_extent_header *neh; 823 struct ext4_extent_idx *fidx; 824 struct ext4_extent *ex; 825 int i = at, k, m, a; 826 ext4_fsblk_t newblock, oldblock; 827 __le32 border; 828 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ 829 int err = 0; 830 831 /* make decision: where to split? */ 832 833 /* if current leaf will be split, then we should use 834 * border from split point */ 835 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) { 836 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!"); 837 return -EIO; 838 } 839 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { 840 border = path[depth].p_ext[1].ee_block; 841 ext_debug("leaf will be split." 842 " next leaf starts at %d\n", 843 le32_to_cpu(border)); 844 } else { 845 border = newext->ee_block; 846 ext_debug("leaf will be added." 847 " next leaf starts at %d\n", 848 le32_to_cpu(border)); 849 } 850 851 /* 852 * If error occurs, then we break processing 853 * and mark filesystem read-only. index won't 854 * be inserted and tree will be in consistent 855 * state. Next mount will repair buffers too. 856 */ 857 858 /* 859 * Get array to track all allocated blocks. 860 * We need this to handle errors and free blocks 861 * upon them. 862 */ 863 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); 864 if (!ablocks) 865 return -ENOMEM; 866 867 /* allocate all needed blocks */ 868 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); 869 for (a = 0; a < depth - at; a++) { 870 newblock = ext4_ext_new_meta_block(handle, inode, path, 871 newext, &err); 872 if (newblock == 0) 873 goto cleanup; 874 ablocks[a] = newblock; 875 } 876 877 /* initialize new leaf */ 878 newblock = ablocks[--a]; 879 if (unlikely(newblock == 0)) { 880 EXT4_ERROR_INODE(inode, "newblock == 0!"); 881 err = -EIO; 882 goto cleanup; 883 } 884 bh = sb_getblk(inode->i_sb, newblock); 885 if (!bh) { 886 err = -EIO; 887 goto cleanup; 888 } 889 lock_buffer(bh); 890 891 err = ext4_journal_get_create_access(handle, bh); 892 if (err) 893 goto cleanup; 894 895 neh = ext_block_hdr(bh); 896 neh->eh_entries = 0; 897 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); 898 neh->eh_magic = EXT4_EXT_MAGIC; 899 neh->eh_depth = 0; 900 ex = EXT_FIRST_EXTENT(neh); 901 902 /* move remainder of path[depth] to the new leaf */ 903 if (unlikely(path[depth].p_hdr->eh_entries != 904 path[depth].p_hdr->eh_max)) { 905 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!", 906 path[depth].p_hdr->eh_entries, 907 path[depth].p_hdr->eh_max); 908 err = -EIO; 909 goto cleanup; 910 } 911 /* start copy from next extent */ 912 /* TODO: we could do it by single memmove */ 913 m = 0; 914 path[depth].p_ext++; 915 while (path[depth].p_ext <= 916 EXT_MAX_EXTENT(path[depth].p_hdr)) { 917 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n", 918 le32_to_cpu(path[depth].p_ext->ee_block), 919 ext_pblock(path[depth].p_ext), 920 ext4_ext_is_uninitialized(path[depth].p_ext), 921 ext4_ext_get_actual_len(path[depth].p_ext), 922 newblock); 923 /*memmove(ex++, path[depth].p_ext++, 924 sizeof(struct ext4_extent)); 925 neh->eh_entries++;*/ 926 path[depth].p_ext++; 927 m++; 928 } 929 if (m) { 930 memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m); 931 le16_add_cpu(&neh->eh_entries, m); 932 } 933 934 set_buffer_uptodate(bh); 935 unlock_buffer(bh); 936 937 err = ext4_handle_dirty_metadata(handle, inode, bh); 938 if (err) 939 goto cleanup; 940 brelse(bh); 941 bh = NULL; 942 943 /* correct old leaf */ 944 if (m) { 945 err = ext4_ext_get_access(handle, inode, path + depth); 946 if (err) 947 goto cleanup; 948 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m); 949 err = ext4_ext_dirty(handle, inode, path + depth); 950 if (err) 951 goto cleanup; 952 953 } 954 955 /* create intermediate indexes */ 956 k = depth - at - 1; 957 if (unlikely(k < 0)) { 958 EXT4_ERROR_INODE(inode, "k %d < 0!", k); 959 err = -EIO; 960 goto cleanup; 961 } 962 if (k) 963 ext_debug("create %d intermediate indices\n", k); 964 /* insert new index into current index block */ 965 /* current depth stored in i var */ 966 i = depth - 1; 967 while (k--) { 968 oldblock = newblock; 969 newblock = ablocks[--a]; 970 bh = sb_getblk(inode->i_sb, newblock); 971 if (!bh) { 972 err = -EIO; 973 goto cleanup; 974 } 975 lock_buffer(bh); 976 977 err = ext4_journal_get_create_access(handle, bh); 978 if (err) 979 goto cleanup; 980 981 neh = ext_block_hdr(bh); 982 neh->eh_entries = cpu_to_le16(1); 983 neh->eh_magic = EXT4_EXT_MAGIC; 984 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); 985 neh->eh_depth = cpu_to_le16(depth - i); 986 fidx = EXT_FIRST_INDEX(neh); 987 fidx->ei_block = border; 988 ext4_idx_store_pblock(fidx, oldblock); 989 990 ext_debug("int.index at %d (block %llu): %u -> %llu\n", 991 i, newblock, le32_to_cpu(border), oldblock); 992 /* copy indexes */ 993 m = 0; 994 path[i].p_idx++; 995 996 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, 997 EXT_MAX_INDEX(path[i].p_hdr)); 998 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) != 999 EXT_LAST_INDEX(path[i].p_hdr))) { 1000 EXT4_ERROR_INODE(inode, 1001 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!", 1002 le32_to_cpu(path[i].p_ext->ee_block)); 1003 err = -EIO; 1004 goto cleanup; 1005 } 1006 while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) { 1007 ext_debug("%d: move %d:%llu in new index %llu\n", i, 1008 le32_to_cpu(path[i].p_idx->ei_block), 1009 idx_pblock(path[i].p_idx), 1010 newblock); 1011 /*memmove(++fidx, path[i].p_idx++, 1012 sizeof(struct ext4_extent_idx)); 1013 neh->eh_entries++; 1014 BUG_ON(neh->eh_entries > neh->eh_max);*/ 1015 path[i].p_idx++; 1016 m++; 1017 } 1018 if (m) { 1019 memmove(++fidx, path[i].p_idx - m, 1020 sizeof(struct ext4_extent_idx) * m); 1021 le16_add_cpu(&neh->eh_entries, m); 1022 } 1023 set_buffer_uptodate(bh); 1024 unlock_buffer(bh); 1025 1026 err = ext4_handle_dirty_metadata(handle, inode, bh); 1027 if (err) 1028 goto cleanup; 1029 brelse(bh); 1030 bh = NULL; 1031 1032 /* correct old index */ 1033 if (m) { 1034 err = ext4_ext_get_access(handle, inode, path + i); 1035 if (err) 1036 goto cleanup; 1037 le16_add_cpu(&path[i].p_hdr->eh_entries, -m); 1038 err = ext4_ext_dirty(handle, inode, path + i); 1039 if (err) 1040 goto cleanup; 1041 } 1042 1043 i--; 1044 } 1045 1046 /* insert new index */ 1047 err = ext4_ext_insert_index(handle, inode, path + at, 1048 le32_to_cpu(border), newblock); 1049 1050cleanup: 1051 if (bh) { 1052 if (buffer_locked(bh)) 1053 unlock_buffer(bh); 1054 brelse(bh); 1055 } 1056 1057 if (err) { 1058 /* free all allocated blocks in error case */ 1059 for (i = 0; i < depth; i++) { 1060 if (!ablocks[i]) 1061 continue; 1062 ext4_free_blocks(handle, inode, 0, ablocks[i], 1, 1063 EXT4_FREE_BLOCKS_METADATA); 1064 } 1065 } 1066 kfree(ablocks); 1067 1068 return err; 1069} 1070 1071/* 1072 * ext4_ext_grow_indepth: 1073 * implements tree growing procedure: 1074 * - allocates new block 1075 * - moves top-level data (index block or leaf) into the new block 1076 * - initializes new top-level, creating index that points to the 1077 * just created block 1078 */ 1079static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, 1080 struct ext4_ext_path *path, 1081 struct ext4_extent *newext) 1082{ 1083 struct ext4_ext_path *curp = path; 1084 struct ext4_extent_header *neh; 1085 struct buffer_head *bh; 1086 ext4_fsblk_t newblock; 1087 int err = 0; 1088 1089 newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err); 1090 if (newblock == 0) 1091 return err; 1092 1093 bh = sb_getblk(inode->i_sb, newblock); 1094 if (!bh) { 1095 err = -EIO; 1096 ext4_std_error(inode->i_sb, err); 1097 return err; 1098 } 1099 lock_buffer(bh); 1100 1101 err = ext4_journal_get_create_access(handle, bh); 1102 if (err) { 1103 unlock_buffer(bh); 1104 goto out; 1105 } 1106 1107 /* move top-level index/leaf into new block */ 1108 memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data)); 1109 1110 /* set size of new block */ 1111 neh = ext_block_hdr(bh); 1112 /* old root could have indexes or leaves 1113 * so calculate e_max right way */ 1114 if (ext_depth(inode)) 1115 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); 1116 else 1117 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); 1118 neh->eh_magic = EXT4_EXT_MAGIC; 1119 set_buffer_uptodate(bh); 1120 unlock_buffer(bh); 1121 1122 err = ext4_handle_dirty_metadata(handle, inode, bh); 1123 if (err) 1124 goto out; 1125 1126 /* create index in new top-level index: num,max,pointer */ 1127 err = ext4_ext_get_access(handle, inode, curp); 1128 if (err) 1129 goto out; 1130 1131 curp->p_hdr->eh_magic = EXT4_EXT_MAGIC; 1132 curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); 1133 curp->p_hdr->eh_entries = cpu_to_le16(1); 1134 curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr); 1135 1136 if (path[0].p_hdr->eh_depth) 1137 curp->p_idx->ei_block = 1138 EXT_FIRST_INDEX(path[0].p_hdr)->ei_block; 1139 else 1140 curp->p_idx->ei_block = 1141 EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block; 1142 ext4_idx_store_pblock(curp->p_idx, newblock); 1143 1144 neh = ext_inode_hdr(inode); 1145 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", 1146 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), 1147 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), 1148 idx_pblock(EXT_FIRST_INDEX(neh))); 1149 1150 neh->eh_depth = cpu_to_le16(path->p_depth + 1); 1151 err = ext4_ext_dirty(handle, inode, curp); 1152out: 1153 brelse(bh); 1154 1155 return err; 1156} 1157 1158/* 1159 * ext4_ext_create_new_leaf: 1160 * finds empty index and adds new leaf. 1161 * if no free index is found, then it requests in-depth growing. 1162 */ 1163static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, 1164 struct ext4_ext_path *path, 1165 struct ext4_extent *newext) 1166{ 1167 struct ext4_ext_path *curp; 1168 int depth, i, err = 0; 1169 1170repeat: 1171 i = depth = ext_depth(inode); 1172 1173 /* walk up to the tree and look for free index entry */ 1174 curp = path + depth; 1175 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { 1176 i--; 1177 curp--; 1178 } 1179 1180 /* we use already allocated block for index block, 1181 * so subsequent data blocks should be contiguous */ 1182 if (EXT_HAS_FREE_INDEX(curp)) { 1183 /* if we found index with free entry, then use that 1184 * entry: create all needed subtree and add new leaf */ 1185 err = ext4_ext_split(handle, inode, path, newext, i); 1186 if (err) 1187 goto out; 1188 1189 /* refill path */ 1190 ext4_ext_drop_refs(path); 1191 path = ext4_ext_find_extent(inode, 1192 (ext4_lblk_t)le32_to_cpu(newext->ee_block), 1193 path); 1194 if (IS_ERR(path)) 1195 err = PTR_ERR(path); 1196 } else { 1197 /* tree is full, time to grow in depth */ 1198 err = ext4_ext_grow_indepth(handle, inode, path, newext); 1199 if (err) 1200 goto out; 1201 1202 /* refill path */ 1203 ext4_ext_drop_refs(path); 1204 path = ext4_ext_find_extent(inode, 1205 (ext4_lblk_t)le32_to_cpu(newext->ee_block), 1206 path); 1207 if (IS_ERR(path)) { 1208 err = PTR_ERR(path); 1209 goto out; 1210 } 1211 1212 /* 1213 * only first (depth 0 -> 1) produces free space; 1214 * in all other cases we have to split the grown tree 1215 */ 1216 depth = ext_depth(inode); 1217 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { 1218 /* now we need to split */ 1219 goto repeat; 1220 } 1221 } 1222 1223out: 1224 return err; 1225} 1226 1227/* 1228 * search the closest allocated block to the left for *logical 1229 * and returns it at @logical + it's physical address at @phys 1230 * if *logical is the smallest allocated block, the function 1231 * returns 0 at @phys 1232 * return value contains 0 (success) or error code 1233 */ 1234int 1235ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path, 1236 ext4_lblk_t *logical, ext4_fsblk_t *phys) 1237{ 1238 struct ext4_extent_idx *ix; 1239 struct ext4_extent *ex; 1240 int depth, ee_len; 1241 1242 if (unlikely(path == NULL)) { 1243 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); 1244 return -EIO; 1245 } 1246 depth = path->p_depth; 1247 *phys = 0; 1248 1249 if (depth == 0 && path->p_ext == NULL) 1250 return 0; 1251 1252 /* usually extent in the path covers blocks smaller 1253 * then *logical, but it can be that extent is the 1254 * first one in the file */ 1255 1256 ex = path[depth].p_ext; 1257 ee_len = ext4_ext_get_actual_len(ex); 1258 if (*logical < le32_to_cpu(ex->ee_block)) { 1259 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { 1260 EXT4_ERROR_INODE(inode, 1261 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!", 1262 *logical, le32_to_cpu(ex->ee_block)); 1263 return -EIO; 1264 } 1265 while (--depth >= 0) { 1266 ix = path[depth].p_idx; 1267 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { 1268 EXT4_ERROR_INODE(inode, 1269 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!", 1270 ix != NULL ? ix->ei_block : 0, 1271 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ? 1272 EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block : 0, 1273 depth); 1274 return -EIO; 1275 } 1276 } 1277 return 0; 1278 } 1279 1280 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { 1281 EXT4_ERROR_INODE(inode, 1282 "logical %d < ee_block %d + ee_len %d!", 1283 *logical, le32_to_cpu(ex->ee_block), ee_len); 1284 return -EIO; 1285 } 1286 1287 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; 1288 *phys = ext_pblock(ex) + ee_len - 1; 1289 return 0; 1290} 1291 1292/* 1293 * search the closest allocated block to the right for *logical 1294 * and returns it at @logical + it's physical address at @phys 1295 * if *logical is the smallest allocated block, the function 1296 * returns 0 at @phys 1297 * return value contains 0 (success) or error code 1298 */ 1299int 1300ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, 1301 ext4_lblk_t *logical, ext4_fsblk_t *phys) 1302{ 1303 struct buffer_head *bh = NULL; 1304 struct ext4_extent_header *eh; 1305 struct ext4_extent_idx *ix; 1306 struct ext4_extent *ex; 1307 ext4_fsblk_t block; 1308 int depth; /* Note, NOT eh_depth; depth from top of tree */ 1309 int ee_len; 1310 1311 if (unlikely(path == NULL)) { 1312 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); 1313 return -EIO; 1314 } 1315 depth = path->p_depth; 1316 *phys = 0; 1317 1318 if (depth == 0 && path->p_ext == NULL) 1319 return 0; 1320 1321 /* usually extent in the path covers blocks smaller 1322 * then *logical, but it can be that extent is the 1323 * first one in the file */ 1324 1325 ex = path[depth].p_ext; 1326 ee_len = ext4_ext_get_actual_len(ex); 1327 if (*logical < le32_to_cpu(ex->ee_block)) { 1328 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { 1329 EXT4_ERROR_INODE(inode, 1330 "first_extent(path[%d].p_hdr) != ex", 1331 depth); 1332 return -EIO; 1333 } 1334 while (--depth >= 0) { 1335 ix = path[depth].p_idx; 1336 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { 1337 EXT4_ERROR_INODE(inode, 1338 "ix != EXT_FIRST_INDEX *logical %d!", 1339 *logical); 1340 return -EIO; 1341 } 1342 } 1343 *logical = le32_to_cpu(ex->ee_block); 1344 *phys = ext_pblock(ex); 1345 return 0; 1346 } 1347 1348 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { 1349 EXT4_ERROR_INODE(inode, 1350 "logical %d < ee_block %d + ee_len %d!", 1351 *logical, le32_to_cpu(ex->ee_block), ee_len); 1352 return -EIO; 1353 } 1354 1355 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { 1356 /* next allocated block in this leaf */ 1357 ex++; 1358 *logical = le32_to_cpu(ex->ee_block); 1359 *phys = ext_pblock(ex); 1360 return 0; 1361 } 1362 1363 /* go up and search for index to the right */ 1364 while (--depth >= 0) { 1365 ix = path[depth].p_idx; 1366 if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) 1367 goto got_index; 1368 } 1369 1370 /* we've gone up to the root and found no index to the right */ 1371 return 0; 1372 1373got_index: 1374 /* we've found index to the right, let's 1375 * follow it and find the closest allocated 1376 * block to the right */ 1377 ix++; 1378 block = idx_pblock(ix); 1379 while (++depth < path->p_depth) { 1380 bh = sb_bread(inode->i_sb, block); 1381 if (bh == NULL) 1382 return -EIO; 1383 eh = ext_block_hdr(bh); 1384 /* subtract from p_depth to get proper eh_depth */ 1385 if (ext4_ext_check(inode, eh, path->p_depth - depth)) { 1386 put_bh(bh); 1387 return -EIO; 1388 } 1389 ix = EXT_FIRST_INDEX(eh); 1390 block = idx_pblock(ix); 1391 put_bh(bh); 1392 } 1393 1394 bh = sb_bread(inode->i_sb, block); 1395 if (bh == NULL) 1396 return -EIO; 1397 eh = ext_block_hdr(bh); 1398 if (ext4_ext_check(inode, eh, path->p_depth - depth)) { 1399 put_bh(bh); 1400 return -EIO; 1401 } 1402 ex = EXT_FIRST_EXTENT(eh); 1403 *logical = le32_to_cpu(ex->ee_block); 1404 *phys = ext_pblock(ex); 1405 put_bh(bh); 1406 return 0; 1407} 1408 1409/* 1410 * ext4_ext_next_allocated_block: 1411 * returns allocated block in subsequent extent or EXT_MAX_BLOCK. 1412 * NOTE: it considers block number from index entry as 1413 * allocated block. Thus, index entries have to be consistent 1414 * with leaves. 1415 */ 1416static ext4_lblk_t 1417ext4_ext_next_allocated_block(struct ext4_ext_path *path) 1418{ 1419 int depth; 1420 1421 BUG_ON(path == NULL); 1422 depth = path->p_depth; 1423 1424 if (depth == 0 && path->p_ext == NULL) 1425 return EXT_MAX_BLOCK; 1426 1427 while (depth >= 0) { 1428 if (depth == path->p_depth) { 1429 /* leaf */ 1430 if (path[depth].p_ext != 1431 EXT_LAST_EXTENT(path[depth].p_hdr)) 1432 return le32_to_cpu(path[depth].p_ext[1].ee_block); 1433 } else { 1434 /* index */ 1435 if (path[depth].p_idx != 1436 EXT_LAST_INDEX(path[depth].p_hdr)) 1437 return le32_to_cpu(path[depth].p_idx[1].ei_block); 1438 } 1439 depth--; 1440 } 1441 1442 return EXT_MAX_BLOCK; 1443} 1444 1445/* 1446 * ext4_ext_next_leaf_block: 1447 * returns first allocated block from next leaf or EXT_MAX_BLOCK 1448 */ 1449static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode, 1450 struct ext4_ext_path *path) 1451{ 1452 int depth; 1453 1454 BUG_ON(path == NULL); 1455 depth = path->p_depth; 1456 1457 /* zero-tree has no leaf blocks at all */ 1458 if (depth == 0) 1459 return EXT_MAX_BLOCK; 1460 1461 /* go to index block */ 1462 depth--; 1463 1464 while (depth >= 0) { 1465 if (path[depth].p_idx != 1466 EXT_LAST_INDEX(path[depth].p_hdr)) 1467 return (ext4_lblk_t) 1468 le32_to_cpu(path[depth].p_idx[1].ei_block); 1469 depth--; 1470 } 1471 1472 return EXT_MAX_BLOCK; 1473} 1474 1475/* 1476 * ext4_ext_correct_indexes: 1477 * if leaf gets modified and modified extent is first in the leaf, 1478 * then we have to correct all indexes above. 1479 * TODO: do we need to correct tree in all cases? 1480 */ 1481static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, 1482 struct ext4_ext_path *path) 1483{ 1484 struct ext4_extent_header *eh; 1485 int depth = ext_depth(inode); 1486 struct ext4_extent *ex; 1487 __le32 border; 1488 int k, err = 0; 1489 1490 eh = path[depth].p_hdr; 1491 ex = path[depth].p_ext; 1492 1493 if (unlikely(ex == NULL || eh == NULL)) { 1494 EXT4_ERROR_INODE(inode, 1495 "ex %p == NULL or eh %p == NULL", ex, eh); 1496 return -EIO; 1497 } 1498 1499 if (depth == 0) { 1500 /* there is no tree at all */ 1501 return 0; 1502 } 1503 1504 if (ex != EXT_FIRST_EXTENT(eh)) { 1505 /* we correct tree if first leaf got modified only */ 1506 return 0; 1507 } 1508 1509 /* 1510 * TODO: we need correction if border is smaller than current one 1511 */ 1512 k = depth - 1; 1513 border = path[depth].p_ext->ee_block; 1514 err = ext4_ext_get_access(handle, inode, path + k); 1515 if (err) 1516 return err; 1517 path[k].p_idx->ei_block = border; 1518 err = ext4_ext_dirty(handle, inode, path + k); 1519 if (err) 1520 return err; 1521 1522 while (k--) { 1523 /* change all left-side indexes */ 1524 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) 1525 break; 1526 err = ext4_ext_get_access(handle, inode, path + k); 1527 if (err) 1528 break; 1529 path[k].p_idx->ei_block = border; 1530 err = ext4_ext_dirty(handle, inode, path + k); 1531 if (err) 1532 break; 1533 } 1534 1535 return err; 1536} 1537 1538int 1539ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, 1540 struct ext4_extent *ex2) 1541{ 1542 unsigned short ext1_ee_len, ext2_ee_len, max_len; 1543 1544 /* 1545 * Make sure that either both extents are uninitialized, or 1546 * both are _not_. 1547 */ 1548 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2)) 1549 return 0; 1550 1551 if (ext4_ext_is_uninitialized(ex1)) 1552 max_len = EXT_UNINIT_MAX_LEN; 1553 else 1554 max_len = EXT_INIT_MAX_LEN; 1555 1556 ext1_ee_len = ext4_ext_get_actual_len(ex1); 1557 ext2_ee_len = ext4_ext_get_actual_len(ex2); 1558 1559 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != 1560 le32_to_cpu(ex2->ee_block)) 1561 return 0; 1562 1563 /* 1564 * To allow future support for preallocated extents to be added 1565 * as an RO_COMPAT feature, refuse to merge to extents if 1566 * this can result in the top bit of ee_len being set. 1567 */ 1568 if (ext1_ee_len + ext2_ee_len > max_len) 1569 return 0; 1570#ifdef AGGRESSIVE_TEST 1571 if (ext1_ee_len >= 4) 1572 return 0; 1573#endif 1574 1575 if (ext_pblock(ex1) + ext1_ee_len == ext_pblock(ex2)) 1576 return 1; 1577 return 0; 1578} 1579 1580/* 1581 * This function tries to merge the "ex" extent to the next extent in the tree. 1582 * It always tries to merge towards right. If you want to merge towards 1583 * left, pass "ex - 1" as argument instead of "ex". 1584 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns 1585 * 1 if they got merged. 1586 */ 1587int ext4_ext_try_to_merge(struct inode *inode, 1588 struct ext4_ext_path *path, 1589 struct ext4_extent *ex) 1590{ 1591 struct ext4_extent_header *eh; 1592 unsigned int depth, len; 1593 int merge_done = 0; 1594 int uninitialized = 0; 1595 1596 depth = ext_depth(inode); 1597 BUG_ON(path[depth].p_hdr == NULL); 1598 eh = path[depth].p_hdr; 1599 1600 while (ex < EXT_LAST_EXTENT(eh)) { 1601 if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) 1602 break; 1603 /* merge with next extent! */ 1604 if (ext4_ext_is_uninitialized(ex)) 1605 uninitialized = 1; 1606 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 1607 + ext4_ext_get_actual_len(ex + 1)); 1608 if (uninitialized) 1609 ext4_ext_mark_uninitialized(ex); 1610 1611 if (ex + 1 < EXT_LAST_EXTENT(eh)) { 1612 len = (EXT_LAST_EXTENT(eh) - ex - 1) 1613 * sizeof(struct ext4_extent); 1614 memmove(ex + 1, ex + 2, len); 1615 } 1616 le16_add_cpu(&eh->eh_entries, -1); 1617 merge_done = 1; 1618 WARN_ON(eh->eh_entries == 0); 1619 if (!eh->eh_entries) 1620 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!"); 1621 } 1622 1623 return merge_done; 1624} 1625 1626/* 1627 * check if a portion of the "newext" extent overlaps with an 1628 * existing extent. 1629 * 1630 * If there is an overlap discovered, it updates the length of the newext 1631 * such that there will be no overlap, and then returns 1. 1632 * If there is no overlap found, it returns 0. 1633 */ 1634unsigned int ext4_ext_check_overlap(struct inode *inode, 1635 struct ext4_extent *newext, 1636 struct ext4_ext_path *path) 1637{ 1638 ext4_lblk_t b1, b2; 1639 unsigned int depth, len1; 1640 unsigned int ret = 0; 1641 1642 b1 = le32_to_cpu(newext->ee_block); 1643 len1 = ext4_ext_get_actual_len(newext); 1644 depth = ext_depth(inode); 1645 if (!path[depth].p_ext) 1646 goto out; 1647 b2 = le32_to_cpu(path[depth].p_ext->ee_block); 1648 1649 /* 1650 * get the next allocated block if the extent in the path 1651 * is before the requested block(s) 1652 */ 1653 if (b2 < b1) { 1654 b2 = ext4_ext_next_allocated_block(path); 1655 if (b2 == EXT_MAX_BLOCK) 1656 goto out; 1657 } 1658 1659 /* check for wrap through zero on extent logical start block*/ 1660 if (b1 + len1 < b1) { 1661 len1 = EXT_MAX_BLOCK - b1; 1662 newext->ee_len = cpu_to_le16(len1); 1663 ret = 1; 1664 } 1665 1666 /* check for overlap */ 1667 if (b1 + len1 > b2) { 1668 newext->ee_len = cpu_to_le16(b2 - b1); 1669 ret = 1; 1670 } 1671out: 1672 return ret; 1673} 1674 1675/* 1676 * ext4_ext_insert_extent: 1677 * tries to merge requsted extent into the existing extent or 1678 * inserts requested extent as new one into the tree, 1679 * creating new leaf in the no-space case. 1680 */ 1681int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, 1682 struct ext4_ext_path *path, 1683 struct ext4_extent *newext, int flag) 1684{ 1685 struct ext4_extent_header *eh; 1686 struct ext4_extent *ex, *fex; 1687 struct ext4_extent *nearex; /* nearest extent */ 1688 struct ext4_ext_path *npath = NULL; 1689 int depth, len, err; 1690 ext4_lblk_t next; 1691 unsigned uninitialized = 0; 1692 1693 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) { 1694 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0"); 1695 return -EIO; 1696 } 1697 depth = ext_depth(inode); 1698 ex = path[depth].p_ext; 1699 if (unlikely(path[depth].p_hdr == NULL)) { 1700 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); 1701 return -EIO; 1702 } 1703 1704 /* try to insert block into found extent and return */ 1705 if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO) 1706 && ext4_can_extents_be_merged(inode, ex, newext)) { 1707 ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n", 1708 ext4_ext_is_uninitialized(newext), 1709 ext4_ext_get_actual_len(newext), 1710 le32_to_cpu(ex->ee_block), 1711 ext4_ext_is_uninitialized(ex), 1712 ext4_ext_get_actual_len(ex), ext_pblock(ex)); 1713 err = ext4_ext_get_access(handle, inode, path + depth); 1714 if (err) 1715 return err; 1716 1717 /* 1718 * ext4_can_extents_be_merged should have checked that either 1719 * both extents are uninitialized, or both aren't. Thus we 1720 * need to check only one of them here. 1721 */ 1722 if (ext4_ext_is_uninitialized(ex)) 1723 uninitialized = 1; 1724 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 1725 + ext4_ext_get_actual_len(newext)); 1726 if (uninitialized) 1727 ext4_ext_mark_uninitialized(ex); 1728 eh = path[depth].p_hdr; 1729 nearex = ex; 1730 goto merge; 1731 } 1732 1733repeat: 1734 depth = ext_depth(inode); 1735 eh = path[depth].p_hdr; 1736 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) 1737 goto has_space; 1738 1739 /* probably next leaf has space for us? */ 1740 fex = EXT_LAST_EXTENT(eh); 1741 next = ext4_ext_next_leaf_block(inode, path); 1742 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block) 1743 && next != EXT_MAX_BLOCK) { 1744 ext_debug("next leaf block - %d\n", next); 1745 BUG_ON(npath != NULL); 1746 npath = ext4_ext_find_extent(inode, next, NULL); 1747 if (IS_ERR(npath)) 1748 return PTR_ERR(npath); 1749 BUG_ON(npath->p_depth != path->p_depth); 1750 eh = npath[depth].p_hdr; 1751 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { 1752 ext_debug("next leaf isnt full(%d)\n", 1753 le16_to_cpu(eh->eh_entries)); 1754 path = npath; 1755 goto repeat; 1756 } 1757 ext_debug("next leaf has no free space(%d,%d)\n", 1758 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); 1759 } 1760 1761 /* 1762 * There is no free space in the found leaf. 1763 * We're gonna add a new leaf in the tree. 1764 */ 1765 err = ext4_ext_create_new_leaf(handle, inode, path, newext); 1766 if (err) 1767 goto cleanup; 1768 depth = ext_depth(inode); 1769 eh = path[depth].p_hdr; 1770 1771has_space: 1772 nearex = path[depth].p_ext; 1773 1774 err = ext4_ext_get_access(handle, inode, path + depth); 1775 if (err) 1776 goto cleanup; 1777 1778 if (!nearex) { 1779 /* there is no extent in this leaf, create first one */ 1780 ext_debug("first extent in the leaf: %d:%llu:[%d]%d\n", 1781 le32_to_cpu(newext->ee_block), 1782 ext_pblock(newext), 1783 ext4_ext_is_uninitialized(newext), 1784 ext4_ext_get_actual_len(newext)); 1785 path[depth].p_ext = EXT_FIRST_EXTENT(eh); 1786 } else if (le32_to_cpu(newext->ee_block) 1787 > le32_to_cpu(nearex->ee_block)) { 1788/* BUG_ON(newext->ee_block == nearex->ee_block); */ 1789 if (nearex != EXT_LAST_EXTENT(eh)) { 1790 len = EXT_MAX_EXTENT(eh) - nearex; 1791 len = (len - 1) * sizeof(struct ext4_extent); 1792 len = len < 0 ? 0 : len; 1793 ext_debug("insert %d:%llu:[%d]%d after: nearest 0x%p, " 1794 "move %d from 0x%p to 0x%p\n", 1795 le32_to_cpu(newext->ee_block), 1796 ext_pblock(newext), 1797 ext4_ext_is_uninitialized(newext), 1798 ext4_ext_get_actual_len(newext), 1799 nearex, len, nearex + 1, nearex + 2); 1800 memmove(nearex + 2, nearex + 1, len); 1801 } 1802 path[depth].p_ext = nearex + 1; 1803 } else { 1804 BUG_ON(newext->ee_block == nearex->ee_block); 1805 len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent); 1806 len = len < 0 ? 0 : len; 1807 ext_debug("insert %d:%llu:[%d]%d before: nearest 0x%p, " 1808 "move %d from 0x%p to 0x%p\n", 1809 le32_to_cpu(newext->ee_block), 1810 ext_pblock(newext), 1811 ext4_ext_is_uninitialized(newext), 1812 ext4_ext_get_actual_len(newext), 1813 nearex, len, nearex + 1, nearex + 2); 1814 memmove(nearex + 1, nearex, len); 1815 path[depth].p_ext = nearex; 1816 } 1817 1818 le16_add_cpu(&eh->eh_entries, 1); 1819 nearex = path[depth].p_ext; 1820 nearex->ee_block = newext->ee_block; 1821 ext4_ext_store_pblock(nearex, ext_pblock(newext)); 1822 nearex->ee_len = newext->ee_len; 1823 1824merge: 1825 /* try to merge extents to the right */ 1826 if (!(flag & EXT4_GET_BLOCKS_PRE_IO)) 1827 ext4_ext_try_to_merge(inode, path, nearex); 1828 1829 /* try to merge extents to the left */ 1830 1831 /* time to correct all indexes above */ 1832 err = ext4_ext_correct_indexes(handle, inode, path); 1833 if (err) 1834 goto cleanup; 1835 1836 err = ext4_ext_dirty(handle, inode, path + depth); 1837 1838cleanup: 1839 if (npath) { 1840 ext4_ext_drop_refs(npath); 1841 kfree(npath); 1842 } 1843 ext4_ext_invalidate_cache(inode); 1844 return err; 1845} 1846 1847int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block, 1848 ext4_lblk_t num, ext_prepare_callback func, 1849 void *cbdata) 1850{ 1851 struct ext4_ext_path *path = NULL; 1852 struct ext4_ext_cache cbex; 1853 struct ext4_extent *ex; 1854 ext4_lblk_t next, start = 0, end = 0; 1855 ext4_lblk_t last = block + num; 1856 int depth, exists, err = 0; 1857 1858 BUG_ON(func == NULL); 1859 BUG_ON(inode == NULL); 1860 1861 while (block < last && block != EXT_MAX_BLOCK) { 1862 num = last - block; 1863 /* find extent for this block */ 1864 down_read(&EXT4_I(inode)->i_data_sem); 1865 path = ext4_ext_find_extent(inode, block, path); 1866 up_read(&EXT4_I(inode)->i_data_sem); 1867 if (IS_ERR(path)) { 1868 err = PTR_ERR(path); 1869 path = NULL; 1870 break; 1871 } 1872 1873 depth = ext_depth(inode); 1874 if (unlikely(path[depth].p_hdr == NULL)) { 1875 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); 1876 err = -EIO; 1877 break; 1878 } 1879 ex = path[depth].p_ext; 1880 next = ext4_ext_next_allocated_block(path); 1881 1882 exists = 0; 1883 if (!ex) { 1884 /* there is no extent yet, so try to allocate 1885 * all requested space */ 1886 start = block; 1887 end = block + num; 1888 } else if (le32_to_cpu(ex->ee_block) > block) { 1889 /* need to allocate space before found extent */ 1890 start = block; 1891 end = le32_to_cpu(ex->ee_block); 1892 if (block + num < end) 1893 end = block + num; 1894 } else if (block >= le32_to_cpu(ex->ee_block) 1895 + ext4_ext_get_actual_len(ex)) { 1896 /* need to allocate space after found extent */ 1897 start = block; 1898 end = block + num; 1899 if (end >= next) 1900 end = next; 1901 } else if (block >= le32_to_cpu(ex->ee_block)) { 1902 /* 1903 * some part of requested space is covered 1904 * by found extent 1905 */ 1906 start = block; 1907 end = le32_to_cpu(ex->ee_block) 1908 + ext4_ext_get_actual_len(ex); 1909 if (block + num < end) 1910 end = block + num; 1911 exists = 1; 1912 } else { 1913 BUG(); 1914 } 1915 BUG_ON(end <= start); 1916 1917 if (!exists) { 1918 cbex.ec_block = start; 1919 cbex.ec_len = end - start; 1920 cbex.ec_start = 0; 1921 cbex.ec_type = EXT4_EXT_CACHE_GAP; 1922 } else { 1923 cbex.ec_block = le32_to_cpu(ex->ee_block); 1924 cbex.ec_len = ext4_ext_get_actual_len(ex); 1925 cbex.ec_start = ext_pblock(ex); 1926 cbex.ec_type = EXT4_EXT_CACHE_EXTENT; 1927 } 1928 1929 if (unlikely(cbex.ec_len == 0)) { 1930 EXT4_ERROR_INODE(inode, "cbex.ec_len == 0"); 1931 err = -EIO; 1932 break; 1933 } 1934 err = func(inode, path, &cbex, ex, cbdata); 1935 ext4_ext_drop_refs(path); 1936 1937 if (err < 0) 1938 break; 1939 1940 if (err == EXT_REPEAT) 1941 continue; 1942 else if (err == EXT_BREAK) { 1943 err = 0; 1944 break; 1945 } 1946 1947 if (ext_depth(inode) != depth) { 1948 /* depth was changed. we have to realloc path */ 1949 kfree(path); 1950 path = NULL; 1951 } 1952 1953 block = cbex.ec_block + cbex.ec_len; 1954 } 1955 1956 if (path) { 1957 ext4_ext_drop_refs(path); 1958 kfree(path); 1959 } 1960 1961 return err; 1962} 1963 1964static void 1965ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block, 1966 __u32 len, ext4_fsblk_t start, int type) 1967{ 1968 struct ext4_ext_cache *cex; 1969 BUG_ON(len == 0); 1970 spin_lock(&EXT4_I(inode)->i_block_reservation_lock); 1971 cex = &EXT4_I(inode)->i_cached_extent; 1972 cex->ec_type = type; 1973 cex->ec_block = block; 1974 cex->ec_len = len; 1975 cex->ec_start = start; 1976 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); 1977} 1978 1979/* 1980 * ext4_ext_put_gap_in_cache: 1981 * calculate boundaries of the gap that the requested block fits into 1982 * and cache this gap 1983 */ 1984static void 1985ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, 1986 ext4_lblk_t block) 1987{ 1988 int depth = ext_depth(inode); 1989 unsigned long len; 1990 ext4_lblk_t lblock; 1991 struct ext4_extent *ex; 1992 1993 ex = path[depth].p_ext; 1994 if (ex == NULL) { 1995 /* there is no extent yet, so gap is [0;-] */ 1996 lblock = 0; 1997 len = EXT_MAX_BLOCK; 1998 ext_debug("cache gap(whole file):"); 1999 } else if (block < le32_to_cpu(ex->ee_block)) { 2000 lblock = block; 2001 len = le32_to_cpu(ex->ee_block) - block; 2002 ext_debug("cache gap(before): %u [%u:%u]", 2003 block, 2004 le32_to_cpu(ex->ee_block), 2005 ext4_ext_get_actual_len(ex)); 2006 } else if (block >= le32_to_cpu(ex->ee_block) 2007 + ext4_ext_get_actual_len(ex)) { 2008 ext4_lblk_t next; 2009 lblock = le32_to_cpu(ex->ee_block) 2010 + ext4_ext_get_actual_len(ex); 2011 2012 next = ext4_ext_next_allocated_block(path); 2013 ext_debug("cache gap(after): [%u:%u] %u", 2014 le32_to_cpu(ex->ee_block), 2015 ext4_ext_get_actual_len(ex), 2016 block); 2017 BUG_ON(next == lblock); 2018 len = next - lblock; 2019 } else { 2020 lblock = len = 0; 2021 BUG(); 2022 } 2023 2024 ext_debug(" -> %u:%lu\n", lblock, len); 2025 ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP); 2026} 2027 2028static int 2029ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, 2030 struct ext4_extent *ex) 2031{ 2032 struct ext4_ext_cache *cex; 2033 int ret = EXT4_EXT_CACHE_NO; 2034 2035 /* 2036 * We borrow i_block_reservation_lock to protect i_cached_extent 2037 */ 2038 spin_lock(&EXT4_I(inode)->i_block_reservation_lock); 2039 cex = &EXT4_I(inode)->i_cached_extent; 2040 2041 /* has cache valid data? */ 2042 if (cex->ec_type == EXT4_EXT_CACHE_NO) 2043 goto errout; 2044 2045 BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP && 2046 cex->ec_type != EXT4_EXT_CACHE_EXTENT); 2047 if (in_range(block, cex->ec_block, cex->ec_len)) { 2048 ex->ee_block = cpu_to_le32(cex->ec_block); 2049 ext4_ext_store_pblock(ex, cex->ec_start); 2050 ex->ee_len = cpu_to_le16(cex->ec_len); 2051 ext_debug("%u cached by %u:%u:%llu\n", 2052 block, 2053 cex->ec_block, cex->ec_len, cex->ec_start); 2054 ret = cex->ec_type; 2055 } 2056errout: 2057 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); 2058 return ret; 2059} 2060 2061/* 2062 * ext4_ext_rm_idx: 2063 * removes index from the index block. 2064 * It's used in truncate case only, thus all requests are for 2065 * last index in the block only. 2066 */ 2067static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, 2068 struct ext4_ext_path *path) 2069{ 2070 int err; 2071 ext4_fsblk_t leaf; 2072 2073 /* free index block */ 2074 path--; 2075 leaf = idx_pblock(path->p_idx); 2076 if (unlikely(path->p_hdr->eh_entries == 0)) { 2077 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0"); 2078 return -EIO; 2079 } 2080 err = ext4_ext_get_access(handle, inode, path); 2081 if (err) 2082 return err; 2083 le16_add_cpu(&path->p_hdr->eh_entries, -1); 2084 err = ext4_ext_dirty(handle, inode, path); 2085 if (err) 2086 return err; 2087 ext_debug("index is empty, remove it, free block %llu\n", leaf); 2088 ext4_free_blocks(handle, inode, 0, leaf, 1, 2089 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); 2090 return err; 2091} 2092 2093/* 2094 * ext4_ext_calc_credits_for_single_extent: 2095 * This routine returns max. credits that needed to insert an extent 2096 * to the extent tree. 2097 * When pass the actual path, the caller should calculate credits 2098 * under i_data_sem. 2099 */ 2100int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks, 2101 struct ext4_ext_path *path) 2102{ 2103 if (path) { 2104 int depth = ext_depth(inode); 2105 int ret = 0; 2106 2107 /* probably there is space in leaf? */ 2108 if (le16_to_cpu(path[depth].p_hdr->eh_entries) 2109 < le16_to_cpu(path[depth].p_hdr->eh_max)) { 2110 2111 /* 2112 * There are some space in the leaf tree, no 2113 * need to account for leaf block credit 2114 * 2115 * bitmaps and block group descriptor blocks 2116 * and other metadat blocks still need to be 2117 * accounted. 2118 */ 2119 /* 1 bitmap, 1 block group descriptor */ 2120 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb); 2121 return ret; 2122 } 2123 } 2124 2125 return ext4_chunk_trans_blocks(inode, nrblocks); 2126} 2127 2128/* 2129 * How many index/leaf blocks need to change/allocate to modify nrblocks? 2130 * 2131 * if nrblocks are fit in a single extent (chunk flag is 1), then 2132 * in the worse case, each tree level index/leaf need to be changed 2133 * if the tree split due to insert a new extent, then the old tree 2134 * index/leaf need to be updated too 2135 * 2136 * If the nrblocks are discontiguous, they could cause 2137 * the whole tree split more than once, but this is really rare. 2138 */ 2139int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk) 2140{ 2141 int index; 2142 int depth = ext_depth(inode); 2143 2144 if (chunk) 2145 index = depth * 2; 2146 else 2147 index = depth * 3; 2148 2149 return index; 2150} 2151 2152static int ext4_remove_blocks(handle_t *handle, struct inode *inode, 2153 struct ext4_extent *ex, 2154 ext4_lblk_t from, ext4_lblk_t to) 2155{ 2156 unsigned short ee_len = ext4_ext_get_actual_len(ex); 2157 int flags = EXT4_FREE_BLOCKS_FORGET; 2158 2159 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) 2160 flags |= EXT4_FREE_BLOCKS_METADATA; 2161#ifdef EXTENTS_STATS 2162 { 2163 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2164 spin_lock(&sbi->s_ext_stats_lock); 2165 sbi->s_ext_blocks += ee_len; 2166 sbi->s_ext_extents++; 2167 if (ee_len < sbi->s_ext_min) 2168 sbi->s_ext_min = ee_len; 2169 if (ee_len > sbi->s_ext_max) 2170 sbi->s_ext_max = ee_len; 2171 if (ext_depth(inode) > sbi->s_depth_max) 2172 sbi->s_depth_max = ext_depth(inode); 2173 spin_unlock(&sbi->s_ext_stats_lock); 2174 } 2175#endif 2176 if (from >= le32_to_cpu(ex->ee_block) 2177 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) { 2178 /* tail removal */ 2179 ext4_lblk_t num; 2180 ext4_fsblk_t start; 2181 2182 num = le32_to_cpu(ex->ee_block) + ee_len - from; 2183 start = ext_pblock(ex) + ee_len - num; 2184 ext_debug("free last %u blocks starting %llu\n", num, start); 2185 ext4_free_blocks(handle, inode, 0, start, num, flags); 2186 } else if (from == le32_to_cpu(ex->ee_block) 2187 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) { 2188 printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n", 2189 from, to, le32_to_cpu(ex->ee_block), ee_len); 2190 } else { 2191 printk(KERN_INFO "strange request: removal(2) " 2192 "%u-%u from %u:%u\n", 2193 from, to, le32_to_cpu(ex->ee_block), ee_len); 2194 } 2195 return 0; 2196} 2197 2198static int 2199ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, 2200 struct ext4_ext_path *path, ext4_lblk_t start) 2201{ 2202 int err = 0, correct_index = 0; 2203 int depth = ext_depth(inode), credits; 2204 struct ext4_extent_header *eh; 2205 ext4_lblk_t a, b, block; 2206 unsigned num; 2207 ext4_lblk_t ex_ee_block; 2208 unsigned short ex_ee_len; 2209 unsigned uninitialized = 0; 2210 struct ext4_extent *ex; 2211 2212 /* the header must be checked already in ext4_ext_remove_space() */ 2213 ext_debug("truncate since %u in leaf\n", start); 2214 if (!path[depth].p_hdr) 2215 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); 2216 eh = path[depth].p_hdr; 2217 if (unlikely(path[depth].p_hdr == NULL)) { 2218 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); 2219 return -EIO; 2220 } 2221 /* find where to start removing */ 2222 ex = EXT_LAST_EXTENT(eh); 2223 2224 ex_ee_block = le32_to_cpu(ex->ee_block); 2225 ex_ee_len = ext4_ext_get_actual_len(ex); 2226 2227 while (ex >= EXT_FIRST_EXTENT(eh) && 2228 ex_ee_block + ex_ee_len > start) { 2229 2230 if (ext4_ext_is_uninitialized(ex)) 2231 uninitialized = 1; 2232 else 2233 uninitialized = 0; 2234 2235 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block, 2236 uninitialized, ex_ee_len); 2237 path[depth].p_ext = ex; 2238 2239 a = ex_ee_block > start ? ex_ee_block : start; 2240 b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ? 2241 ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK; 2242 2243 ext_debug(" border %u:%u\n", a, b); 2244 2245 if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { 2246 block = 0; 2247 num = 0; 2248 BUG(); 2249 } else if (a != ex_ee_block) { 2250 /* remove tail of the extent */ 2251 block = ex_ee_block; 2252 num = a - block; 2253 } else if (b != ex_ee_block + ex_ee_len - 1) { 2254 /* remove head of the extent */ 2255 block = a; 2256 num = b - a; 2257 /* there is no "make a hole" API yet */ 2258 BUG(); 2259 } else { 2260 /* remove whole extent: excellent! */ 2261 block = ex_ee_block; 2262 num = 0; 2263 BUG_ON(a != ex_ee_block); 2264 BUG_ON(b != ex_ee_block + ex_ee_len - 1); 2265 } 2266 2267 /* 2268 * 3 for leaf, sb, and inode plus 2 (bmap and group 2269 * descriptor) for each block group; assume two block 2270 * groups plus ex_ee_len/blocks_per_block_group for 2271 * the worst case 2272 */ 2273 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb)); 2274 if (ex == EXT_FIRST_EXTENT(eh)) { 2275 correct_index = 1; 2276 credits += (ext_depth(inode)) + 1; 2277 } 2278 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb); 2279 2280 err = ext4_ext_truncate_extend_restart(handle, inode, credits); 2281 if (err) 2282 goto out; 2283 2284 err = ext4_ext_get_access(handle, inode, path + depth); 2285 if (err) 2286 goto out; 2287 2288 err = ext4_remove_blocks(handle, inode, ex, a, b); 2289 if (err) 2290 goto out; 2291 2292 if (num == 0) { 2293 /* this extent is removed; mark slot entirely unused */ 2294 ext4_ext_store_pblock(ex, 0); 2295 le16_add_cpu(&eh->eh_entries, -1); 2296 } 2297 2298 ex->ee_block = cpu_to_le32(block); 2299 ex->ee_len = cpu_to_le16(num); 2300 /* 2301 * Do not mark uninitialized if all the blocks in the 2302 * extent have been removed. 2303 */ 2304 if (uninitialized && num) 2305 ext4_ext_mark_uninitialized(ex); 2306 2307 err = ext4_ext_dirty(handle, inode, path + depth); 2308 if (err) 2309 goto out; 2310 2311 ext_debug("new extent: %u:%u:%llu\n", block, num, 2312 ext_pblock(ex)); 2313 ex--; 2314 ex_ee_block = le32_to_cpu(ex->ee_block); 2315 ex_ee_len = ext4_ext_get_actual_len(ex); 2316 } 2317 2318 if (correct_index && eh->eh_entries) 2319 err = ext4_ext_correct_indexes(handle, inode, path); 2320 2321 /* if this leaf is free, then we should 2322 * remove it from index block above */ 2323 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) 2324 err = ext4_ext_rm_idx(handle, inode, path + depth); 2325 2326out: 2327 return err; 2328} 2329 2330/* 2331 * ext4_ext_more_to_rm: 2332 * returns 1 if current index has to be freed (even partial) 2333 */ 2334static int 2335ext4_ext_more_to_rm(struct ext4_ext_path *path) 2336{ 2337 BUG_ON(path->p_idx == NULL); 2338 2339 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) 2340 return 0; 2341 2342 /* 2343 * if truncate on deeper level happened, it wasn't partial, 2344 * so we have to consider current index for truncation 2345 */ 2346 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) 2347 return 0; 2348 return 1; 2349} 2350 2351static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) 2352{ 2353 struct super_block *sb = inode->i_sb; 2354 int depth = ext_depth(inode); 2355 struct ext4_ext_path *path; 2356 handle_t *handle; 2357 int i, err; 2358 2359 ext_debug("truncate since %u\n", start); 2360 2361 /* probably first extent we're gonna free will be last in block */ 2362 handle = ext4_journal_start(inode, depth + 1); 2363 if (IS_ERR(handle)) 2364 return PTR_ERR(handle); 2365 2366again: 2367 ext4_ext_invalidate_cache(inode); 2368 2369 /* 2370 * We start scanning from right side, freeing all the blocks 2371 * after i_size and walking into the tree depth-wise. 2372 */ 2373 depth = ext_depth(inode); 2374 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS); 2375 if (path == NULL) { 2376 ext4_journal_stop(handle); 2377 return -ENOMEM; 2378 } 2379 path[0].p_depth = depth; 2380 path[0].p_hdr = ext_inode_hdr(inode); 2381 if (ext4_ext_check(inode, path[0].p_hdr, depth)) { 2382 err = -EIO; 2383 goto out; 2384 } 2385 i = err = 0; 2386 2387 while (i >= 0 && err == 0) { 2388 if (i == depth) { 2389 /* this is leaf block */ 2390 err = ext4_ext_rm_leaf(handle, inode, path, start); 2391 /* root level has p_bh == NULL, brelse() eats this */ 2392 brelse(path[i].p_bh); 2393 path[i].p_bh = NULL; 2394 i--; 2395 continue; 2396 } 2397 2398 /* this is index block */ 2399 if (!path[i].p_hdr) { 2400 ext_debug("initialize header\n"); 2401 path[i].p_hdr = ext_block_hdr(path[i].p_bh); 2402 } 2403 2404 if (!path[i].p_idx) { 2405 /* this level hasn't been touched yet */ 2406 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); 2407 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; 2408 ext_debug("init index ptr: hdr 0x%p, num %d\n", 2409 path[i].p_hdr, 2410 le16_to_cpu(path[i].p_hdr->eh_entries)); 2411 } else { 2412 /* we were already here, see at next index */ 2413 path[i].p_idx--; 2414 } 2415 2416 ext_debug("level %d - index, first 0x%p, cur 0x%p\n", 2417 i, EXT_FIRST_INDEX(path[i].p_hdr), 2418 path[i].p_idx); 2419 if (ext4_ext_more_to_rm(path + i)) { 2420 struct buffer_head *bh; 2421 /* go to the next level */ 2422 ext_debug("move to level %d (block %llu)\n", 2423 i + 1, idx_pblock(path[i].p_idx)); 2424 memset(path + i + 1, 0, sizeof(*path)); 2425 bh = sb_bread(sb, idx_pblock(path[i].p_idx)); 2426 if (!bh) { 2427 /* should we reset i_size? */ 2428 err = -EIO; 2429 break; 2430 } 2431 if (WARN_ON(i + 1 > depth)) { 2432 err = -EIO; 2433 break; 2434 } 2435 if (ext4_ext_check(inode, ext_block_hdr(bh), 2436 depth - i - 1)) { 2437 err = -EIO; 2438 break; 2439 } 2440 path[i + 1].p_bh = bh; 2441 2442 /* save actual number of indexes since this 2443 * number is changed at the next iteration */ 2444 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); 2445 i++; 2446 } else { 2447 /* we finished processing this index, go up */ 2448 if (path[i].p_hdr->eh_entries == 0 && i > 0) { 2449 /* index is empty, remove it; 2450 * handle must be already prepared by the 2451 * truncatei_leaf() */ 2452 err = ext4_ext_rm_idx(handle, inode, path + i); 2453 } 2454 /* root level has p_bh == NULL, brelse() eats this */ 2455 brelse(path[i].p_bh); 2456 path[i].p_bh = NULL; 2457 i--; 2458 ext_debug("return to level %d\n", i); 2459 } 2460 } 2461 2462 /* TODO: flexible tree reduction should be here */ 2463 if (path->p_hdr->eh_entries == 0) { 2464 /* 2465 * truncate to zero freed all the tree, 2466 * so we need to correct eh_depth 2467 */ 2468 err = ext4_ext_get_access(handle, inode, path); 2469 if (err == 0) { 2470 ext_inode_hdr(inode)->eh_depth = 0; 2471 ext_inode_hdr(inode)->eh_max = 2472 cpu_to_le16(ext4_ext_space_root(inode, 0)); 2473 err = ext4_ext_dirty(handle, inode, path); 2474 } 2475 } 2476out: 2477 ext4_ext_drop_refs(path); 2478 kfree(path); 2479 if (err == -EAGAIN) 2480 goto again; 2481 ext4_journal_stop(handle); 2482 2483 return err; 2484} 2485 2486/* 2487 * called at mount time 2488 */ 2489void ext4_ext_init(struct super_block *sb) 2490{ 2491 /* 2492 * possible initialization would be here 2493 */ 2494 2495 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) { 2496#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS) 2497 printk(KERN_INFO "EXT4-fs: file extents enabled"); 2498#ifdef AGGRESSIVE_TEST 2499 printk(", aggressive tests"); 2500#endif 2501#ifdef CHECK_BINSEARCH 2502 printk(", check binsearch"); 2503#endif 2504#ifdef EXTENTS_STATS 2505 printk(", stats"); 2506#endif 2507 printk("\n"); 2508#endif 2509#ifdef EXTENTS_STATS 2510 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); 2511 EXT4_SB(sb)->s_ext_min = 1 << 30; 2512 EXT4_SB(sb)->s_ext_max = 0; 2513#endif 2514 } 2515} 2516 2517/* 2518 * called at umount time 2519 */ 2520void ext4_ext_release(struct super_block *sb) 2521{ 2522 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) 2523 return; 2524 2525#ifdef EXTENTS_STATS 2526 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { 2527 struct ext4_sb_info *sbi = EXT4_SB(sb); 2528 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", 2529 sbi->s_ext_blocks, sbi->s_ext_extents, 2530 sbi->s_ext_blocks / sbi->s_ext_extents); 2531 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", 2532 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); 2533 } 2534#endif 2535} 2536 2537static void bi_complete(struct bio *bio, int error) 2538{ 2539 complete((struct completion *)bio->bi_private); 2540} 2541 2542static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) 2543{ 2544 int ret; 2545 struct bio *bio; 2546 int blkbits, blocksize; 2547 sector_t ee_pblock; 2548 struct completion event; 2549 unsigned int ee_len, len, done, offset; 2550 2551 2552 blkbits = inode->i_blkbits; 2553 blocksize = inode->i_sb->s_blocksize; 2554 ee_len = ext4_ext_get_actual_len(ex); 2555 ee_pblock = ext_pblock(ex); 2556 2557 /* convert ee_pblock to 512 byte sectors */ 2558 ee_pblock = ee_pblock << (blkbits - 9); 2559 2560 while (ee_len > 0) { 2561 2562 if (ee_len > BIO_MAX_PAGES) 2563 len = BIO_MAX_PAGES; 2564 else 2565 len = ee_len; 2566 2567 bio = bio_alloc(GFP_NOIO, len); 2568 if (!bio) 2569 return -ENOMEM; 2570 2571 bio->bi_sector = ee_pblock; 2572 bio->bi_bdev = inode->i_sb->s_bdev; 2573 2574 done = 0; 2575 offset = 0; 2576 while (done < len) { 2577 ret = bio_add_page(bio, ZERO_PAGE(0), 2578 blocksize, offset); 2579 if (ret != blocksize) { 2580 /* 2581 * We can't add any more pages because of 2582 * hardware limitations. Start a new bio. 2583 */ 2584 break; 2585 } 2586 done++; 2587 offset += blocksize; 2588 if (offset >= PAGE_CACHE_SIZE) 2589 offset = 0; 2590 } 2591 2592 init_completion(&event); 2593 bio->bi_private = &event; 2594 bio->bi_end_io = bi_complete; 2595 submit_bio(WRITE, bio); 2596 wait_for_completion(&event); 2597 2598 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) { 2599 bio_put(bio); 2600 return -EIO; 2601 } 2602 bio_put(bio); 2603 ee_len -= done; 2604 ee_pblock += done << (blkbits - 9); 2605 } 2606 return 0; 2607} 2608 2609#define EXT4_EXT_ZERO_LEN 7 2610/* 2611 * This function is called by ext4_ext_map_blocks() if someone tries to write 2612 * to an uninitialized extent. It may result in splitting the uninitialized 2613 * extent into multiple extents (upto three - one initialized and two 2614 * uninitialized). 2615 * There are three possibilities: 2616 * a> There is no split required: Entire extent should be initialized 2617 * b> Splits in two extents: Write is happening at either end of the extent 2618 * c> Splits in three extents: Somone is writing in middle of the extent 2619 */ 2620static int ext4_ext_convert_to_initialized(handle_t *handle, 2621 struct inode *inode, 2622 struct ext4_map_blocks *map, 2623 struct ext4_ext_path *path) 2624{ 2625 struct ext4_extent *ex, newex, orig_ex; 2626 struct ext4_extent *ex1 = NULL; 2627 struct ext4_extent *ex2 = NULL; 2628 struct ext4_extent *ex3 = NULL; 2629 struct ext4_extent_header *eh; 2630 ext4_lblk_t ee_block, eof_block; 2631 unsigned int allocated, ee_len, depth; 2632 ext4_fsblk_t newblock; 2633 int err = 0; 2634 int ret = 0; 2635 int may_zeroout; 2636 2637 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical" 2638 "block %llu, max_blocks %u\n", inode->i_ino, 2639 (unsigned long long)map->m_lblk, map->m_len); 2640 2641 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> 2642 inode->i_sb->s_blocksize_bits; 2643 if (eof_block < map->m_lblk + map->m_len) 2644 eof_block = map->m_lblk + map->m_len; 2645 2646 depth = ext_depth(inode); 2647 eh = path[depth].p_hdr; 2648 ex = path[depth].p_ext; 2649 ee_block = le32_to_cpu(ex->ee_block); 2650 ee_len = ext4_ext_get_actual_len(ex); 2651 allocated = ee_len - (map->m_lblk - ee_block); 2652 newblock = map->m_lblk - ee_block + ext_pblock(ex); 2653 2654 ex2 = ex; 2655 orig_ex.ee_block = ex->ee_block; 2656 orig_ex.ee_len = cpu_to_le16(ee_len); 2657 ext4_ext_store_pblock(&orig_ex, ext_pblock(ex)); 2658 2659 /* 2660 * It is safe to convert extent to initialized via explicit 2661 * zeroout only if extent is fully insde i_size or new_size. 2662 */ 2663 may_zeroout = ee_block + ee_len <= eof_block; 2664 2665 err = ext4_ext_get_access(handle, inode, path + depth); 2666 if (err) 2667 goto out; 2668 /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */ 2669 if (ee_len <= 2*EXT4_EXT_ZERO_LEN && may_zeroout) { 2670 err = ext4_ext_zeroout(inode, &orig_ex); 2671 if (err) 2672 goto fix_extent_len; 2673 /* update the extent length and mark as initialized */ 2674 ex->ee_block = orig_ex.ee_block; 2675 ex->ee_len = orig_ex.ee_len; 2676 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); 2677 ext4_ext_dirty(handle, inode, path + depth); 2678 /* zeroed the full extent */ 2679 return allocated; 2680 } 2681 2682 /* ex1: ee_block to map->m_lblk - 1 : uninitialized */ 2683 if (map->m_lblk > ee_block) { 2684 ex1 = ex; 2685 ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block); 2686 ext4_ext_mark_uninitialized(ex1); 2687 ex2 = &newex; 2688 } 2689 /* 2690 * for sanity, update the length of the ex2 extent before 2691 * we insert ex3, if ex1 is NULL. This is to avoid temporary 2692 * overlap of blocks. 2693 */ 2694 if (!ex1 && allocated > map->m_len) 2695 ex2->ee_len = cpu_to_le16(map->m_len); 2696 /* ex3: to ee_block + ee_len : uninitialised */ 2697 if (allocated > map->m_len) { 2698 unsigned int newdepth; 2699 /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */ 2700 if (allocated <= EXT4_EXT_ZERO_LEN && may_zeroout) { 2701 /* 2702 * map->m_lblk == ee_block is handled by the zerouout 2703 * at the beginning. 2704 * Mark first half uninitialized. 2705 * Mark second half initialized and zero out the 2706 * initialized extent 2707 */ 2708 ex->ee_block = orig_ex.ee_block; 2709 ex->ee_len = cpu_to_le16(ee_len - allocated); 2710 ext4_ext_mark_uninitialized(ex); 2711 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); 2712 ext4_ext_dirty(handle, inode, path + depth); 2713 2714 ex3 = &newex; 2715 ex3->ee_block = cpu_to_le32(map->m_lblk); 2716 ext4_ext_store_pblock(ex3, newblock); 2717 ex3->ee_len = cpu_to_le16(allocated); 2718 err = ext4_ext_insert_extent(handle, inode, path, 2719 ex3, 0); 2720 if (err == -ENOSPC) { 2721 err = ext4_ext_zeroout(inode, &orig_ex); 2722 if (err) 2723 goto fix_extent_len; 2724 ex->ee_block = orig_ex.ee_block; 2725 ex->ee_len = orig_ex.ee_len; 2726 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); 2727 ext4_ext_dirty(handle, inode, path + depth); 2728 /* blocks available from map->m_lblk */ 2729 return allocated; 2730 2731 } else if (err) 2732 goto fix_extent_len; 2733 2734 /* 2735 * We need to zero out the second half because 2736 * an fallocate request can update file size and 2737 * converting the second half to initialized extent 2738 * implies that we can leak some junk data to user 2739 * space. 2740 */ 2741 err = ext4_ext_zeroout(inode, ex3); 2742 if (err) { 2743 /* 2744 * We should actually mark the 2745 * second half as uninit and return error 2746 * Insert would have changed the extent 2747 */ 2748 depth = ext_depth(inode); 2749 ext4_ext_drop_refs(path); 2750 path = ext4_ext_find_extent(inode, map->m_lblk, 2751 path); 2752 if (IS_ERR(path)) { 2753 err = PTR_ERR(path); 2754 return err; 2755 } 2756 /* get the second half extent details */ 2757 ex = path[depth].p_ext; 2758 err = ext4_ext_get_access(handle, inode, 2759 path + depth); 2760 if (err) 2761 return err; 2762 ext4_ext_mark_uninitialized(ex); 2763 ext4_ext_dirty(handle, inode, path + depth); 2764 return err; 2765 } 2766 2767 /* zeroed the second half */ 2768 return allocated; 2769 } 2770 ex3 = &newex; 2771 ex3->ee_block = cpu_to_le32(map->m_lblk + map->m_len); 2772 ext4_ext_store_pblock(ex3, newblock + map->m_len); 2773 ex3->ee_len = cpu_to_le16(allocated - map->m_len); 2774 ext4_ext_mark_uninitialized(ex3); 2775 err = ext4_ext_insert_extent(handle, inode, path, ex3, 0); 2776 if (err == -ENOSPC && may_zeroout) { 2777 err = ext4_ext_zeroout(inode, &orig_ex); 2778 if (err) 2779 goto fix_extent_len; 2780 /* update the extent length and mark as initialized */ 2781 ex->ee_block = orig_ex.ee_block; 2782 ex->ee_len = orig_ex.ee_len; 2783 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); 2784 ext4_ext_dirty(handle, inode, path + depth); 2785 /* zeroed the full extent */ 2786 /* blocks available from map->m_lblk */ 2787 return allocated; 2788 2789 } else if (err) 2790 goto fix_extent_len; 2791 /* 2792 * The depth, and hence eh & ex might change 2793 * as part of the insert above. 2794 */ 2795 newdepth = ext_depth(inode); 2796 /* 2797 * update the extent length after successful insert of the 2798 * split extent 2799 */ 2800 ee_len -= ext4_ext_get_actual_len(ex3); 2801 orig_ex.ee_len = cpu_to_le16(ee_len); 2802 may_zeroout = ee_block + ee_len <= eof_block; 2803 2804 depth = newdepth; 2805 ext4_ext_drop_refs(path); 2806 path = ext4_ext_find_extent(inode, map->m_lblk, path); 2807 if (IS_ERR(path)) { 2808 err = PTR_ERR(path); 2809 goto out; 2810 } 2811 eh = path[depth].p_hdr; 2812 ex = path[depth].p_ext; 2813 if (ex2 != &newex) 2814 ex2 = ex; 2815 2816 err = ext4_ext_get_access(handle, inode, path + depth); 2817 if (err) 2818 goto out; 2819 2820 allocated = map->m_len; 2821 2822 /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying 2823 * to insert a extent in the middle zerout directly 2824 * otherwise give the extent a chance to merge to left 2825 */ 2826 if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN && 2827 map->m_lblk != ee_block && may_zeroout) { 2828 err = ext4_ext_zeroout(inode, &orig_ex); 2829 if (err) 2830 goto fix_extent_len; 2831 /* update the extent length and mark as initialized */ 2832 ex->ee_block = orig_ex.ee_block; 2833 ex->ee_len = orig_ex.ee_len; 2834 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); 2835 ext4_ext_dirty(handle, inode, path + depth); 2836 /* zero out the first half */ 2837 /* blocks available from map->m_lblk */ 2838 return allocated; 2839 } 2840 } 2841 /* 2842 * If there was a change of depth as part of the 2843 * insertion of ex3 above, we need to update the length 2844 * of the ex1 extent again here 2845 */ 2846 if (ex1 && ex1 != ex) { 2847 ex1 = ex; 2848 ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block); 2849 ext4_ext_mark_uninitialized(ex1); 2850 ex2 = &newex; 2851 } 2852 /* ex2: map->m_lblk to map->m_lblk + maxblocks-1 : initialised */ 2853 ex2->ee_block = cpu_to_le32(map->m_lblk); 2854 ext4_ext_store_pblock(ex2, newblock); 2855 ex2->ee_len = cpu_to_le16(allocated); 2856 if (ex2 != ex) 2857 goto insert; 2858 /* 2859 * New (initialized) extent starts from the first block 2860 * in the current extent. i.e., ex2 == ex 2861 * We have to see if it can be merged with the extent 2862 * on the left. 2863 */ 2864 if (ex2 > EXT_FIRST_EXTENT(eh)) { 2865 /* 2866 * To merge left, pass "ex2 - 1" to try_to_merge(), 2867 * since it merges towards right _only_. 2868 */ 2869 ret = ext4_ext_try_to_merge(inode, path, ex2 - 1); 2870 if (ret) { 2871 err = ext4_ext_correct_indexes(handle, inode, path); 2872 if (err) 2873 goto out; 2874 depth = ext_depth(inode); 2875 ex2--; 2876 } 2877 } 2878 /* 2879 * Try to Merge towards right. This might be required 2880 * only when the whole extent is being written to. 2881 * i.e. ex2 == ex and ex3 == NULL. 2882 */ 2883 if (!ex3) { 2884 ret = ext4_ext_try_to_merge(inode, path, ex2); 2885 if (ret) { 2886 err = ext4_ext_correct_indexes(handle, inode, path); 2887 if (err) 2888 goto out; 2889 } 2890 } 2891 /* Mark modified extent as dirty */ 2892 err = ext4_ext_dirty(handle, inode, path + depth); 2893 goto out; 2894insert: 2895 err = ext4_ext_insert_extent(handle, inode, path, &newex, 0); 2896 if (err == -ENOSPC && may_zeroout) { 2897 err = ext4_ext_zeroout(inode, &orig_ex); 2898 if (err) 2899 goto fix_extent_len; 2900 /* update the extent length and mark as initialized */ 2901 ex->ee_block = orig_ex.ee_block; 2902 ex->ee_len = orig_ex.ee_len; 2903 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); 2904 ext4_ext_dirty(handle, inode, path + depth); 2905 /* zero out the first half */ 2906 return allocated; 2907 } else if (err) 2908 goto fix_extent_len; 2909out: 2910 ext4_ext_show_leaf(inode, path); 2911 return err ? err : allocated; 2912 2913fix_extent_len: 2914 ex->ee_block = orig_ex.ee_block; 2915 ex->ee_len = orig_ex.ee_len; 2916 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); 2917 ext4_ext_mark_uninitialized(ex); 2918 ext4_ext_dirty(handle, inode, path + depth); 2919 return err; 2920} 2921 2922/* 2923 * This function is called by ext4_ext_map_blocks() from 2924 * ext4_get_blocks_dio_write() when DIO to write 2925 * to an uninitialized extent. 2926 * 2927 * Writing to an uninitized extent may result in splitting the uninitialized 2928 * extent into multiple /intialized unintialized extents (up to three) 2929 * There are three possibilities: 2930 * a> There is no split required: Entire extent should be uninitialized 2931 * b> Splits in two extents: Write is happening at either end of the extent 2932 * c> Splits in three extents: Somone is writing in middle of the extent 2933 * 2934 * One of more index blocks maybe needed if the extent tree grow after 2935 * the unintialized extent split. To prevent ENOSPC occur at the IO 2936 * complete, we need to split the uninitialized extent before DIO submit 2937 * the IO. The uninitialized extent called at this time will be split 2938 * into three uninitialized extent(at most). After IO complete, the part 2939 * being filled will be convert to initialized by the end_io callback function 2940 * via ext4_convert_unwritten_extents(). 2941 * 2942 * Returns the size of uninitialized extent to be written on success. 2943 */ 2944static int ext4_split_unwritten_extents(handle_t *handle, 2945 struct inode *inode, 2946 struct ext4_map_blocks *map, 2947 struct ext4_ext_path *path, 2948 int flags) 2949{ 2950 struct ext4_extent *ex, newex, orig_ex; 2951 struct ext4_extent *ex1 = NULL; 2952 struct ext4_extent *ex2 = NULL; 2953 struct ext4_extent *ex3 = NULL; 2954 ext4_lblk_t ee_block, eof_block; 2955 unsigned int allocated, ee_len, depth; 2956 ext4_fsblk_t newblock; 2957 int err = 0; 2958 int may_zeroout; 2959 2960 ext_debug("ext4_split_unwritten_extents: inode %lu, logical" 2961 "block %llu, max_blocks %u\n", inode->i_ino, 2962 (unsigned long long)map->m_lblk, map->m_len); 2963 2964 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> 2965 inode->i_sb->s_blocksize_bits; 2966 if (eof_block < map->m_lblk + map->m_len) 2967 eof_block = map->m_lblk + map->m_len; 2968 2969 depth = ext_depth(inode); 2970 ex = path[depth].p_ext; 2971 ee_block = le32_to_cpu(ex->ee_block); 2972 ee_len = ext4_ext_get_actual_len(ex); 2973 allocated = ee_len - (map->m_lblk - ee_block); 2974 newblock = map->m_lblk - ee_block + ext_pblock(ex); 2975 2976 ex2 = ex; 2977 orig_ex.ee_block = ex->ee_block; 2978 orig_ex.ee_len = cpu_to_le16(ee_len); 2979 ext4_ext_store_pblock(&orig_ex, ext_pblock(ex)); 2980 2981 /* 2982 * It is safe to convert extent to initialized via explicit 2983 * zeroout only if extent is fully insde i_size or new_size. 2984 */ 2985 may_zeroout = ee_block + ee_len <= eof_block; 2986 2987 /* 2988 * If the uninitialized extent begins at the same logical 2989 * block where the write begins, and the write completely 2990 * covers the extent, then we don't need to split it. 2991 */ 2992 if ((map->m_lblk == ee_block) && (allocated <= map->m_len)) 2993 return allocated; 2994 2995 err = ext4_ext_get_access(handle, inode, path + depth); 2996 if (err) 2997 goto out; 2998 /* ex1: ee_block to map->m_lblk - 1 : uninitialized */ 2999 if (map->m_lblk > ee_block) { 3000 ex1 = ex; 3001 ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block); 3002 ext4_ext_mark_uninitialized(ex1); 3003 ex2 = &newex; 3004 } 3005 /* 3006 * for sanity, update the length of the ex2 extent before 3007 * we insert ex3, if ex1 is NULL. This is to avoid temporary 3008 * overlap of blocks. 3009 */ 3010 if (!ex1 && allocated > map->m_len) 3011 ex2->ee_len = cpu_to_le16(map->m_len); 3012 /* ex3: to ee_block + ee_len : uninitialised */ 3013 if (allocated > map->m_len) { 3014 unsigned int newdepth; 3015 ex3 = &newex; 3016 ex3->ee_block = cpu_to_le32(map->m_lblk + map->m_len); 3017 ext4_ext_store_pblock(ex3, newblock + map->m_len); 3018 ex3->ee_len = cpu_to_le16(allocated - map->m_len); 3019 ext4_ext_mark_uninitialized(ex3); 3020 err = ext4_ext_insert_extent(handle, inode, path, ex3, flags); 3021 if (err == -ENOSPC && may_zeroout) { 3022 err = ext4_ext_zeroout(inode, &orig_ex); 3023 if (err) 3024 goto fix_extent_len; 3025 /* update the extent length and mark as initialized */ 3026 ex->ee_block = orig_ex.ee_block; 3027 ex->ee_len = orig_ex.ee_len; 3028 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); 3029 ext4_ext_dirty(handle, inode, path + depth); 3030 /* zeroed the full extent */ 3031 /* blocks available from map->m_lblk */ 3032 return allocated; 3033 3034 } else if (err) 3035 goto fix_extent_len; 3036 /* 3037 * The depth, and hence eh & ex might change 3038 * as part of the insert above. 3039 */ 3040 newdepth = ext_depth(inode); 3041 /* 3042 * update the extent length after successful insert of the 3043 * split extent 3044 */ 3045 ee_len -= ext4_ext_get_actual_len(ex3); 3046 orig_ex.ee_len = cpu_to_le16(ee_len); 3047 may_zeroout = ee_block + ee_len <= eof_block; 3048 3049 depth = newdepth; 3050 ext4_ext_drop_refs(path); 3051 path = ext4_ext_find_extent(inode, map->m_lblk, path); 3052 if (IS_ERR(path)) { 3053 err = PTR_ERR(path); 3054 goto out; 3055 } 3056 ex = path[depth].p_ext; 3057 if (ex2 != &newex) 3058 ex2 = ex; 3059 3060 err = ext4_ext_get_access(handle, inode, path + depth); 3061 if (err) 3062 goto out; 3063 3064 allocated = map->m_len; 3065 } 3066 /* 3067 * If there was a change of depth as part of the 3068 * insertion of ex3 above, we need to update the length 3069 * of the ex1 extent again here 3070 */ 3071 if (ex1 && ex1 != ex) { 3072 ex1 = ex; 3073 ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block); 3074 ext4_ext_mark_uninitialized(ex1); 3075 ex2 = &newex; 3076 } 3077 /* 3078 * ex2: map->m_lblk to map->m_lblk + map->m_len-1 : to be written 3079 * using direct I/O, uninitialised still. 3080 */ 3081 ex2->ee_block = cpu_to_le32(map->m_lblk); 3082 ext4_ext_store_pblock(ex2, newblock); 3083 ex2->ee_len = cpu_to_le16(allocated); 3084 ext4_ext_mark_uninitialized(ex2); 3085 if (ex2 != ex) 3086 goto insert; 3087 /* Mark modified extent as dirty */ 3088 err = ext4_ext_dirty(handle, inode, path + depth); 3089 ext_debug("out here\n"); 3090 goto out; 3091insert: 3092 err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); 3093 if (err == -ENOSPC && may_zeroout) { 3094 err = ext4_ext_zeroout(inode, &orig_ex); 3095 if (err) 3096 goto fix_extent_len; 3097 /* update the extent length and mark as initialized */ 3098 ex->ee_block = orig_ex.ee_block; 3099 ex->ee_len = orig_ex.ee_len; 3100 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); 3101 ext4_ext_dirty(handle, inode, path + depth); 3102 /* zero out the first half */ 3103 return allocated; 3104 } else if (err) 3105 goto fix_extent_len; 3106out: 3107 ext4_ext_show_leaf(inode, path); 3108 return err ? err : allocated; 3109 3110fix_extent_len: 3111 ex->ee_block = orig_ex.ee_block; 3112 ex->ee_len = orig_ex.ee_len; 3113 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); 3114 ext4_ext_mark_uninitialized(ex); 3115 ext4_ext_dirty(handle, inode, path + depth); 3116 return err; 3117} 3118static int ext4_convert_unwritten_extents_endio(handle_t *handle, 3119 struct inode *inode, 3120 struct ext4_ext_path *path) 3121{ 3122 struct ext4_extent *ex; 3123 struct ext4_extent_header *eh; 3124 int depth; 3125 int err = 0; 3126 int ret = 0; 3127 3128 depth = ext_depth(inode); 3129 eh = path[depth].p_hdr; 3130 ex = path[depth].p_ext; 3131 3132 err = ext4_ext_get_access(handle, inode, path + depth); 3133 if (err) 3134 goto out; 3135 /* first mark the extent as initialized */ 3136 ext4_ext_mark_initialized(ex); 3137 3138 /* 3139 * We have to see if it can be merged with the extent 3140 * on the left. 3141 */ 3142 if (ex > EXT_FIRST_EXTENT(eh)) { 3143 /* 3144 * To merge left, pass "ex - 1" to try_to_merge(), 3145 * since it merges towards right _only_. 3146 */ 3147 ret = ext4_ext_try_to_merge(inode, path, ex - 1); 3148 if (ret) { 3149 err = ext4_ext_correct_indexes(handle, inode, path); 3150 if (err) 3151 goto out; 3152 depth = ext_depth(inode); 3153 ex--; 3154 } 3155 } 3156 /* 3157 * Try to Merge towards right. 3158 */ 3159 ret = ext4_ext_try_to_merge(inode, path, ex); 3160 if (ret) { 3161 err = ext4_ext_correct_indexes(handle, inode, path); 3162 if (err) 3163 goto out; 3164 depth = ext_depth(inode); 3165 } 3166 /* Mark modified extent as dirty */ 3167 err = ext4_ext_dirty(handle, inode, path + depth); 3168out: 3169 ext4_ext_show_leaf(inode, path); 3170 return err; 3171} 3172 3173static void unmap_underlying_metadata_blocks(struct block_device *bdev, 3174 sector_t block, int count) 3175{ 3176 int i; 3177 for (i = 0; i < count; i++) 3178 unmap_underlying_metadata(bdev, block + i); 3179} 3180 3181static int 3182ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode, 3183 struct ext4_map_blocks *map, 3184 struct ext4_ext_path *path, int flags, 3185 unsigned int allocated, ext4_fsblk_t newblock) 3186{ 3187 int ret = 0; 3188 int err = 0; 3189 ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio; 3190 3191 ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical" 3192 "block %llu, max_blocks %u, flags %d, allocated %u", 3193 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len, 3194 flags, allocated); 3195 ext4_ext_show_leaf(inode, path); 3196 3197 /* get_block() before submit the IO, split the extent */ 3198 if ((flags & EXT4_GET_BLOCKS_PRE_IO)) { 3199 ret = ext4_split_unwritten_extents(handle, inode, map, 3200 path, flags); 3201 /* 3202 * Flag the inode(non aio case) or end_io struct (aio case) 3203 * that this IO needs to convertion to written when IO is 3204 * completed 3205 */ 3206 if (io) 3207 io->flag = EXT4_IO_UNWRITTEN; 3208 else 3209 ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); 3210 if (ext4_should_dioread_nolock(inode)) 3211 map->m_flags |= EXT4_MAP_UNINIT; 3212 goto out; 3213 } 3214 /* IO end_io complete, convert the filled extent to written */ 3215 if ((flags & EXT4_GET_BLOCKS_CONVERT)) { 3216 ret = ext4_convert_unwritten_extents_endio(handle, inode, 3217 path); 3218 if (ret >= 0) 3219 ext4_update_inode_fsync_trans(handle, inode, 1); 3220 goto out2; 3221 } 3222 /* buffered IO case */ 3223 /* 3224 * repeat fallocate creation request 3225 * we already have an unwritten extent 3226 */ 3227 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) 3228 goto map_out; 3229 3230 /* buffered READ or buffered write_begin() lookup */ 3231 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { 3232 /* 3233 * We have blocks reserved already. We 3234 * return allocated blocks so that delalloc 3235 * won't do block reservation for us. But 3236 * the buffer head will be unmapped so that 3237 * a read from the block returns 0s. 3238 */ 3239 map->m_flags |= EXT4_MAP_UNWRITTEN; 3240 goto out1; 3241 } 3242 3243 /* buffered write, writepage time, convert*/ 3244 ret = ext4_ext_convert_to_initialized(handle, inode, map, path); 3245 if (ret >= 0) 3246 ext4_update_inode_fsync_trans(handle, inode, 1); 3247out: 3248 if (ret <= 0) { 3249 err = ret; 3250 goto out2; 3251 } else 3252 allocated = ret; 3253 map->m_flags |= EXT4_MAP_NEW; 3254 /* 3255 * if we allocated more blocks than requested 3256 * we need to make sure we unmap the extra block 3257 * allocated. The actual needed block will get 3258 * unmapped later when we find the buffer_head marked 3259 * new. 3260 */ 3261 if (allocated > map->m_len) { 3262 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev, 3263 newblock + map->m_len, 3264 allocated - map->m_len); 3265 allocated = map->m_len; 3266 } 3267 3268 /* 3269 * If we have done fallocate with the offset that is already 3270 * delayed allocated, we would have block reservation 3271 * and quota reservation done in the delayed write path. 3272 * But fallocate would have already updated quota and block 3273 * count for this offset. So cancel these reservation 3274 */ 3275 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) 3276 ext4_da_update_reserve_space(inode, allocated, 0); 3277 3278map_out: 3279 map->m_flags |= EXT4_MAP_MAPPED; 3280out1: 3281 if (allocated > map->m_len) 3282 allocated = map->m_len; 3283 ext4_ext_show_leaf(inode, path); 3284 map->m_pblk = newblock; 3285 map->m_len = allocated; 3286out2: 3287 if (path) { 3288 ext4_ext_drop_refs(path); 3289 kfree(path); 3290 } 3291 return err ? err : allocated; 3292} 3293/* 3294 * Block allocation/map/preallocation routine for extents based files 3295 * 3296 * 3297 * Need to be called with 3298 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block 3299 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) 3300 * 3301 * return > 0, number of of blocks already mapped/allocated 3302 * if create == 0 and these are pre-allocated blocks 3303 * buffer head is unmapped 3304 * otherwise blocks are mapped 3305 * 3306 * return = 0, if plain look up failed (blocks have not been allocated) 3307 * buffer head is unmapped 3308 * 3309 * return < 0, error case. 3310 */ 3311int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, 3312 struct ext4_map_blocks *map, int flags) 3313{ 3314 struct ext4_ext_path *path = NULL; 3315 struct ext4_extent_header *eh; 3316 struct ext4_extent newex, *ex, *last_ex; 3317 ext4_fsblk_t newblock; 3318 int i, err = 0, depth, ret, cache_type; 3319 unsigned int allocated = 0; 3320 struct ext4_allocation_request ar; 3321 ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio; 3322 3323 ext_debug("blocks %u/%u requested for inode %lu\n", 3324 map->m_lblk, map->m_len, inode->i_ino); 3325 3326 /* check in cache */ 3327 cache_type = ext4_ext_in_cache(inode, map->m_lblk, &newex); 3328 if (cache_type) { 3329 if (cache_type == EXT4_EXT_CACHE_GAP) { 3330 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { 3331 /* 3332 * block isn't allocated yet and 3333 * user doesn't want to allocate it 3334 */ 3335 goto out2; 3336 } 3337 /* we should allocate requested block */ 3338 } else if (cache_type == EXT4_EXT_CACHE_EXTENT) { 3339 /* block is already allocated */ 3340 newblock = map->m_lblk 3341 - le32_to_cpu(newex.ee_block) 3342 + ext_pblock(&newex); 3343 /* number of remaining blocks in the extent */ 3344 allocated = ext4_ext_get_actual_len(&newex) - 3345 (map->m_lblk - le32_to_cpu(newex.ee_block)); 3346 goto out; 3347 } else { 3348 BUG(); 3349 } 3350 } 3351 3352 /* find extent for this block */ 3353 path = ext4_ext_find_extent(inode, map->m_lblk, NULL); 3354 if (IS_ERR(path)) { 3355 err = PTR_ERR(path); 3356 path = NULL; 3357 goto out2; 3358 } 3359 3360 depth = ext_depth(inode); 3361 3362 /* 3363 * consistent leaf must not be empty; 3364 * this situation is possible, though, _during_ tree modification; 3365 * this is why assert can't be put in ext4_ext_find_extent() 3366 */ 3367 if (unlikely(path[depth].p_ext == NULL && depth != 0)) { 3368 EXT4_ERROR_INODE(inode, "bad extent address " 3369 "lblock: %lu, depth: %d pblock %lld", 3370 (unsigned long) map->m_lblk, depth, 3371 path[depth].p_block); 3372 err = -EIO; 3373 goto out2; 3374 } 3375 eh = path[depth].p_hdr; 3376 3377 ex = path[depth].p_ext; 3378 if (ex) { 3379 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); 3380 ext4_fsblk_t ee_start = ext_pblock(ex); 3381 unsigned short ee_len; 3382 3383 /* 3384 * Uninitialized extents are treated as holes, except that 3385 * we split out initialized portions during a write. 3386 */ 3387 ee_len = ext4_ext_get_actual_len(ex); 3388 /* if found extent covers block, simply return it */ 3389 if (in_range(map->m_lblk, ee_block, ee_len)) { 3390 newblock = map->m_lblk - ee_block + ee_start; 3391 /* number of remaining blocks in the extent */ 3392 allocated = ee_len - (map->m_lblk - ee_block); 3393 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk, 3394 ee_block, ee_len, newblock); 3395 3396 /* Do not put uninitialized extent in the cache */ 3397 if (!ext4_ext_is_uninitialized(ex)) { 3398 ext4_ext_put_in_cache(inode, ee_block, 3399 ee_len, ee_start, 3400 EXT4_EXT_CACHE_EXTENT); 3401 goto out; 3402 } 3403 ret = ext4_ext_handle_uninitialized_extents(handle, 3404 inode, map, path, flags, allocated, 3405 newblock); 3406 return ret; 3407 } 3408 } 3409 3410 /* 3411 * requested block isn't allocated yet; 3412 * we couldn't try to create block if create flag is zero 3413 */ 3414 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { 3415 /* 3416 * put just found gap into cache to speed up 3417 * subsequent requests 3418 */ 3419 ext4_ext_put_gap_in_cache(inode, path, map->m_lblk); 3420 goto out2; 3421 } 3422 /* 3423 * Okay, we need to do block allocation. 3424 */ 3425 3426 /* find neighbour allocated blocks */ 3427 ar.lleft = map->m_lblk; 3428 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); 3429 if (err) 3430 goto out2; 3431 ar.lright = map->m_lblk; 3432 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright); 3433 if (err) 3434 goto out2; 3435 3436 /* 3437 * See if request is beyond maximum number of blocks we can have in 3438 * a single extent. For an initialized extent this limit is 3439 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is 3440 * EXT_UNINIT_MAX_LEN. 3441 */ 3442 if (map->m_len > EXT_INIT_MAX_LEN && 3443 !(flags & EXT4_GET_BLOCKS_UNINIT_EXT)) 3444 map->m_len = EXT_INIT_MAX_LEN; 3445 else if (map->m_len > EXT_UNINIT_MAX_LEN && 3446 (flags & EXT4_GET_BLOCKS_UNINIT_EXT)) 3447 map->m_len = EXT_UNINIT_MAX_LEN; 3448 3449 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */ 3450 newex.ee_block = cpu_to_le32(map->m_lblk); 3451 newex.ee_len = cpu_to_le16(map->m_len); 3452 err = ext4_ext_check_overlap(inode, &newex, path); 3453 if (err) 3454 allocated = ext4_ext_get_actual_len(&newex); 3455 else 3456 allocated = map->m_len; 3457 3458 /* allocate new block */ 3459 ar.inode = inode; 3460 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk); 3461 ar.logical = map->m_lblk; 3462 ar.len = allocated; 3463 if (S_ISREG(inode->i_mode)) 3464 ar.flags = EXT4_MB_HINT_DATA; 3465 else 3466 /* disable in-core preallocation for non-regular files */ 3467 ar.flags = 0; 3468 newblock = ext4_mb_new_blocks(handle, &ar, &err); 3469 if (!newblock) 3470 goto out2; 3471 ext_debug("allocate new block: goal %llu, found %llu/%u\n", 3472 ar.goal, newblock, allocated); 3473 3474 /* try to insert new extent into found leaf and return */ 3475 ext4_ext_store_pblock(&newex, newblock); 3476 newex.ee_len = cpu_to_le16(ar.len); 3477 /* Mark uninitialized */ 3478 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){ 3479 ext4_ext_mark_uninitialized(&newex); 3480 /* 3481 * io_end structure was created for every IO write to an 3482 * uninitialized extent. To avoid unecessary conversion, 3483 * here we flag the IO that really needs the conversion. 3484 * For non asycn direct IO case, flag the inode state 3485 * that we need to perform convertion when IO is done. 3486 */ 3487 if ((flags & EXT4_GET_BLOCKS_PRE_IO)) { 3488 if (io) 3489 io->flag = EXT4_IO_UNWRITTEN; 3490 else 3491 ext4_set_inode_state(inode, 3492 EXT4_STATE_DIO_UNWRITTEN); 3493 } 3494 if (ext4_should_dioread_nolock(inode)) 3495 map->m_flags |= EXT4_MAP_UNINIT; 3496 } 3497 3498 if (unlikely(ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))) { 3499 if (unlikely(!eh->eh_entries)) { 3500 EXT4_ERROR_INODE(inode, 3501 "eh->eh_entries == 0 and " 3502 "EOFBLOCKS_FL set"); 3503 err = -EIO; 3504 goto out2; 3505 } 3506 last_ex = EXT_LAST_EXTENT(eh); 3507 /* 3508 * If the current leaf block was reached by looking at 3509 * the last index block all the way down the tree, and 3510 * we are extending the inode beyond the last extent 3511 * in the current leaf block, then clear the 3512 * EOFBLOCKS_FL flag. 3513 */ 3514 for (i = depth-1; i >= 0; i--) { 3515 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr)) 3516 break; 3517 } 3518 if ((i < 0) && 3519 (map->m_lblk + ar.len > le32_to_cpu(last_ex->ee_block) + 3520 ext4_ext_get_actual_len(last_ex))) 3521 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); 3522 } 3523 err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); 3524 if (err) { 3525 /* free data blocks we just allocated */ 3526 /* not a good idea to call discard here directly, 3527 * but otherwise we'd need to call it every free() */ 3528 ext4_discard_preallocations(inode); 3529 ext4_free_blocks(handle, inode, 0, ext_pblock(&newex), 3530 ext4_ext_get_actual_len(&newex), 0); 3531 goto out2; 3532 } 3533 3534 /* previous routine could use block we allocated */ 3535 newblock = ext_pblock(&newex); 3536 allocated = ext4_ext_get_actual_len(&newex); 3537 if (allocated > map->m_len) 3538 allocated = map->m_len; 3539 map->m_flags |= EXT4_MAP_NEW; 3540 3541 /* 3542 * Update reserved blocks/metadata blocks after successful 3543 * block allocation which had been deferred till now. 3544 */ 3545 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) 3546 ext4_da_update_reserve_space(inode, allocated, 1); 3547 3548 /* 3549 * Cache the extent and update transaction to commit on fdatasync only 3550 * when it is _not_ an uninitialized extent. 3551 */ 3552 if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) { 3553 ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock, 3554 EXT4_EXT_CACHE_EXTENT); 3555 ext4_update_inode_fsync_trans(handle, inode, 1); 3556 } else 3557 ext4_update_inode_fsync_trans(handle, inode, 0); 3558out: 3559 if (allocated > map->m_len) 3560 allocated = map->m_len; 3561 ext4_ext_show_leaf(inode, path); 3562 map->m_flags |= EXT4_MAP_MAPPED; 3563 map->m_pblk = newblock; 3564 map->m_len = allocated; 3565out2: 3566 if (path) { 3567 ext4_ext_drop_refs(path); 3568 kfree(path); 3569 } 3570 return err ? err : allocated; 3571} 3572 3573void ext4_ext_truncate(struct inode *inode) 3574{ 3575 struct address_space *mapping = inode->i_mapping; 3576 struct super_block *sb = inode->i_sb; 3577 ext4_lblk_t last_block; 3578 handle_t *handle; 3579 int err = 0; 3580 3581 /* 3582 * probably first extent we're gonna free will be last in block 3583 */ 3584 err = ext4_writepage_trans_blocks(inode); 3585 handle = ext4_journal_start(inode, err); 3586 if (IS_ERR(handle)) 3587 return; 3588 3589 if (inode->i_size & (sb->s_blocksize - 1)) 3590 ext4_block_truncate_page(handle, mapping, inode->i_size); 3591 3592 if (ext4_orphan_add(handle, inode)) 3593 goto out_stop; 3594 3595 down_write(&EXT4_I(inode)->i_data_sem); 3596 ext4_ext_invalidate_cache(inode); 3597 3598 ext4_discard_preallocations(inode); 3599 3600 /* 3601 * TODO: optimization is possible here. 3602 * Probably we need not scan at all, 3603 * because page truncation is enough. 3604 */ 3605 3606 /* we have to know where to truncate from in crash case */ 3607 EXT4_I(inode)->i_disksize = inode->i_size; 3608 ext4_mark_inode_dirty(handle, inode); 3609 3610 last_block = (inode->i_size + sb->s_blocksize - 1) 3611 >> EXT4_BLOCK_SIZE_BITS(sb); 3612 err = ext4_ext_remove_space(inode, last_block); 3613 3614 /* In a multi-transaction truncate, we only make the final 3615 * transaction synchronous. 3616 */ 3617 if (IS_SYNC(inode)) 3618 ext4_handle_sync(handle); 3619 3620out_stop: 3621 up_write(&EXT4_I(inode)->i_data_sem); 3622 /* 3623 * If this was a simple ftruncate() and the file will remain alive, 3624 * then we need to clear up the orphan record which we created above. 3625 * However, if this was a real unlink then we were called by 3626 * ext4_delete_inode(), and we allow that function to clean up the 3627 * orphan info for us. 3628 */ 3629 if (inode->i_nlink) 3630 ext4_orphan_del(handle, inode); 3631 3632 inode->i_mtime = inode->i_ctime = ext4_current_time(inode); 3633 ext4_mark_inode_dirty(handle, inode); 3634 ext4_journal_stop(handle); 3635} 3636 3637static void ext4_falloc_update_inode(struct inode *inode, 3638 int mode, loff_t new_size, int update_ctime) 3639{ 3640 struct timespec now; 3641 3642 if (update_ctime) { 3643 now = current_fs_time(inode->i_sb); 3644 if (!timespec_equal(&inode->i_ctime, &now)) 3645 inode->i_ctime = now; 3646 } 3647 /* 3648 * Update only when preallocation was requested beyond 3649 * the file size. 3650 */ 3651 if (!(mode & FALLOC_FL_KEEP_SIZE)) { 3652 if (new_size > i_size_read(inode)) 3653 i_size_write(inode, new_size); 3654 if (new_size > EXT4_I(inode)->i_disksize) 3655 ext4_update_i_disksize(inode, new_size); 3656 } else { 3657 /* 3658 * Mark that we allocate beyond EOF so the subsequent truncate 3659 * can proceed even if the new size is the same as i_size. 3660 */ 3661 if (new_size > i_size_read(inode)) 3662 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS); 3663 } 3664 3665} 3666 3667/* 3668 * preallocate space for a file. This implements ext4's fallocate inode 3669 * operation, which gets called from sys_fallocate system call. 3670 * For block-mapped files, posix_fallocate should fall back to the method 3671 * of writing zeroes to the required new blocks (the same behavior which is 3672 * expected for file systems which do not support fallocate() system call). 3673 */ 3674long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len) 3675{ 3676 handle_t *handle; 3677 loff_t new_size; 3678 unsigned int max_blocks; 3679 int ret = 0; 3680 int ret2 = 0; 3681 int retries = 0; 3682 struct ext4_map_blocks map; 3683 unsigned int credits, blkbits = inode->i_blkbits; 3684 3685 /* 3686 * currently supporting (pre)allocate mode for extent-based 3687 * files _only_ 3688 */ 3689 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 3690 return -EOPNOTSUPP; 3691 3692 /* preallocation to directories is currently not supported */ 3693 if (S_ISDIR(inode->i_mode)) 3694 return -ENODEV; 3695 3696 map.m_lblk = offset >> blkbits; 3697 /* 3698 * We can't just convert len to max_blocks because 3699 * If blocksize = 4096 offset = 3072 and len = 2048 3700 */ 3701 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) 3702 - map.m_lblk; 3703 /* 3704 * credits to insert 1 extent into extent tree 3705 */ 3706 credits = ext4_chunk_trans_blocks(inode, max_blocks); 3707 mutex_lock(&inode->i_mutex); 3708 ret = inode_newsize_ok(inode, (len + offset)); 3709 if (ret) { 3710 mutex_unlock(&inode->i_mutex); 3711 return ret; 3712 } 3713retry: 3714 while (ret >= 0 && ret < max_blocks) { 3715 map.m_lblk = map.m_lblk + ret; 3716 map.m_len = max_blocks = max_blocks - ret; 3717 handle = ext4_journal_start(inode, credits); 3718 if (IS_ERR(handle)) { 3719 ret = PTR_ERR(handle); 3720 break; 3721 } 3722 ret = ext4_map_blocks(handle, inode, &map, 3723 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT); 3724 if (ret <= 0) { 3725#ifdef EXT4FS_DEBUG 3726 WARN_ON(ret <= 0); 3727 printk(KERN_ERR "%s: ext4_ext_map_blocks " 3728 "returned error inode#%lu, block=%u, " 3729 "max_blocks=%u", __func__, 3730 inode->i_ino, block, max_blocks); 3731#endif 3732 ext4_mark_inode_dirty(handle, inode); 3733 ret2 = ext4_journal_stop(handle); 3734 break; 3735 } 3736 if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len, 3737 blkbits) >> blkbits)) 3738 new_size = offset + len; 3739 else 3740 new_size = (map.m_lblk + ret) << blkbits; 3741 3742 ext4_falloc_update_inode(inode, mode, new_size, 3743 (map.m_flags & EXT4_MAP_NEW)); 3744 ext4_mark_inode_dirty(handle, inode); 3745 ret2 = ext4_journal_stop(handle); 3746 if (ret2) 3747 break; 3748 } 3749 if (ret == -ENOSPC && 3750 ext4_should_retry_alloc(inode->i_sb, &retries)) { 3751 ret = 0; 3752 goto retry; 3753 } 3754 mutex_unlock(&inode->i_mutex); 3755 return ret > 0 ? ret2 : ret; 3756} 3757 3758/* 3759 * This function convert a range of blocks to written extents 3760 * The caller of this function will pass the start offset and the size. 3761 * all unwritten extents within this range will be converted to 3762 * written extents. 3763 * 3764 * This function is called from the direct IO end io call back 3765 * function, to convert the fallocated extents after IO is completed. 3766 * Returns 0 on success. 3767 */ 3768int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, 3769 ssize_t len) 3770{ 3771 handle_t *handle; 3772 unsigned int max_blocks; 3773 int ret = 0; 3774 int ret2 = 0; 3775 struct ext4_map_blocks map; 3776 unsigned int credits, blkbits = inode->i_blkbits; 3777 3778 map.m_lblk = offset >> blkbits; 3779 /* 3780 * We can't just convert len to max_blocks because 3781 * If blocksize = 4096 offset = 3072 and len = 2048 3782 */ 3783 max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) - 3784 map.m_lblk); 3785 /* 3786 * credits to insert 1 extent into extent tree 3787 */ 3788 credits = ext4_chunk_trans_blocks(inode, max_blocks); 3789 while (ret >= 0 && ret < max_blocks) { 3790 map.m_lblk += ret; 3791 map.m_len = (max_blocks -= ret); 3792 handle = ext4_journal_start(inode, credits); 3793 if (IS_ERR(handle)) { 3794 ret = PTR_ERR(handle); 3795 break; 3796 } 3797 ret = ext4_map_blocks(handle, inode, &map, 3798 EXT4_GET_BLOCKS_IO_CONVERT_EXT); 3799 if (ret <= 0) { 3800 WARN_ON(ret <= 0); 3801 printk(KERN_ERR "%s: ext4_ext_map_blocks " 3802 "returned error inode#%lu, block=%u, " 3803 "max_blocks=%u", __func__, 3804 inode->i_ino, map.m_lblk, map.m_len); 3805 } 3806 ext4_mark_inode_dirty(handle, inode); 3807 ret2 = ext4_journal_stop(handle); 3808 if (ret <= 0 || ret2 ) 3809 break; 3810 } 3811 return ret > 0 ? ret2 : ret; 3812} 3813/* 3814 * Callback function called for each extent to gather FIEMAP information. 3815 */ 3816static int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path, 3817 struct ext4_ext_cache *newex, struct ext4_extent *ex, 3818 void *data) 3819{ 3820 struct fiemap_extent_info *fieinfo = data; 3821 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits; 3822 __u64 logical; 3823 __u64 physical; 3824 __u64 length; 3825 __u32 flags = 0; 3826 int error; 3827 3828 logical = (__u64)newex->ec_block << blksize_bits; 3829 3830 if (newex->ec_type == EXT4_EXT_CACHE_GAP) { 3831 pgoff_t offset; 3832 struct page *page; 3833 struct buffer_head *bh = NULL; 3834 3835 offset = logical >> PAGE_SHIFT; 3836 page = find_get_page(inode->i_mapping, offset); 3837 if (!page || !page_has_buffers(page)) 3838 return EXT_CONTINUE; 3839 3840 bh = page_buffers(page); 3841 3842 if (!bh) 3843 return EXT_CONTINUE; 3844 3845 if (buffer_delay(bh)) { 3846 flags |= FIEMAP_EXTENT_DELALLOC; 3847 page_cache_release(page); 3848 } else { 3849 page_cache_release(page); 3850 return EXT_CONTINUE; 3851 } 3852 } 3853 3854 physical = (__u64)newex->ec_start << blksize_bits; 3855 length = (__u64)newex->ec_len << blksize_bits; 3856 3857 if (ex && ext4_ext_is_uninitialized(ex)) 3858 flags |= FIEMAP_EXTENT_UNWRITTEN; 3859 3860 if (ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK || 3861 newex->ec_block + newex->ec_len - 1 == EXT_MAX_BLOCK) { 3862 loff_t size = i_size_read(inode); 3863 loff_t bs = EXT4_BLOCK_SIZE(inode->i_sb); 3864 3865 flags |= FIEMAP_EXTENT_LAST; 3866 if ((flags & FIEMAP_EXTENT_DELALLOC) && 3867 logical+length > size) 3868 length = (size - logical + bs - 1) & ~(bs-1); 3869 } 3870 3871 error = fiemap_fill_next_extent(fieinfo, logical, physical, 3872 length, flags); 3873 if (error < 0) 3874 return error; 3875 if (error == 1) 3876 return EXT_BREAK; 3877 3878 return EXT_CONTINUE; 3879} 3880 3881/* fiemap flags we can handle specified here */ 3882#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR) 3883 3884static int ext4_xattr_fiemap(struct inode *inode, 3885 struct fiemap_extent_info *fieinfo) 3886{ 3887 __u64 physical = 0; 3888 __u64 length; 3889 __u32 flags = FIEMAP_EXTENT_LAST; 3890 int blockbits = inode->i_sb->s_blocksize_bits; 3891 int error = 0; 3892 3893 /* in-inode? */ 3894 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 3895 struct ext4_iloc iloc; 3896 int offset; /* offset of xattr in inode */ 3897 3898 error = ext4_get_inode_loc(inode, &iloc); 3899 if (error) 3900 return error; 3901 physical = iloc.bh->b_blocknr << blockbits; 3902 offset = EXT4_GOOD_OLD_INODE_SIZE + 3903 EXT4_I(inode)->i_extra_isize; 3904 physical += offset; 3905 length = EXT4_SB(inode->i_sb)->s_inode_size - offset; 3906 flags |= FIEMAP_EXTENT_DATA_INLINE; 3907 brelse(iloc.bh); 3908 } else { /* external block */ 3909 physical = EXT4_I(inode)->i_file_acl << blockbits; 3910 length = inode->i_sb->s_blocksize; 3911 } 3912 3913 if (physical) 3914 error = fiemap_fill_next_extent(fieinfo, 0, physical, 3915 length, flags); 3916 return (error < 0 ? error : 0); 3917} 3918 3919int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 3920 __u64 start, __u64 len) 3921{ 3922 ext4_lblk_t start_blk; 3923 int error = 0; 3924 3925 /* fallback to generic here if not in extents fmt */ 3926 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 3927 return generic_block_fiemap(inode, fieinfo, start, len, 3928 ext4_get_block); 3929 3930 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS)) 3931 return -EBADR; 3932 3933 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { 3934 error = ext4_xattr_fiemap(inode, fieinfo); 3935 } else { 3936 ext4_lblk_t len_blks; 3937 __u64 last_blk; 3938 3939 start_blk = start >> inode->i_sb->s_blocksize_bits; 3940 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits; 3941 if (last_blk >= EXT_MAX_BLOCK) 3942 last_blk = EXT_MAX_BLOCK-1; 3943 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1; 3944 3945 /* 3946 * Walk the extent tree gathering extent information. 3947 * ext4_ext_fiemap_cb will push extents back to user. 3948 */ 3949 error = ext4_ext_walk_space(inode, start_blk, len_blks, 3950 ext4_ext_fiemap_cb, fieinfo); 3951 } 3952 3953 return error; 3954} 3955