extents.c revision 74d3487fc8aa58cec16dff7239dea1ca59bdab0e
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/ext4_jbd2.h> 36#include <linux/jbd2.h> 37#include <linux/highuid.h> 38#include <linux/pagemap.h> 39#include <linux/quotaops.h> 40#include <linux/string.h> 41#include <linux/slab.h> 42#include <linux/falloc.h> 43#include <linux/ext4_fs_extents.h> 44#include <asm/uaccess.h> 45 46 47/* 48 * ext_pblock: 49 * combine low and high parts of physical block number into ext4_fsblk_t 50 */ 51static ext4_fsblk_t ext_pblock(struct ext4_extent *ex) 52{ 53 ext4_fsblk_t block; 54 55 block = le32_to_cpu(ex->ee_start_lo); 56 block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1; 57 return block; 58} 59 60/* 61 * idx_pblock: 62 * combine low and high parts of a leaf physical block number into ext4_fsblk_t 63 */ 64ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix) 65{ 66 ext4_fsblk_t block; 67 68 block = le32_to_cpu(ix->ei_leaf_lo); 69 block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1; 70 return block; 71} 72 73/* 74 * ext4_ext_store_pblock: 75 * stores a large physical block number into an extent struct, 76 * breaking it into parts 77 */ 78void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb) 79{ 80 ex->ee_start_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff)); 81 ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); 82} 83 84/* 85 * ext4_idx_store_pblock: 86 * stores a large physical block number into an index struct, 87 * breaking it into parts 88 */ 89static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb) 90{ 91 ix->ei_leaf_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff)); 92 ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); 93} 94 95static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed) 96{ 97 int err; 98 99 if (handle->h_buffer_credits > needed) 100 return handle; 101 if (!ext4_journal_extend(handle, needed)) 102 return handle; 103 err = ext4_journal_restart(handle, needed); 104 105 return handle; 106} 107 108/* 109 * could return: 110 * - EROFS 111 * - ENOMEM 112 */ 113static int ext4_ext_get_access(handle_t *handle, struct inode *inode, 114 struct ext4_ext_path *path) 115{ 116 if (path->p_bh) { 117 /* path points to block */ 118 return ext4_journal_get_write_access(handle, path->p_bh); 119 } 120 /* path points to leaf/index in inode body */ 121 /* we use in-core data, no need to protect them */ 122 return 0; 123} 124 125/* 126 * could return: 127 * - EROFS 128 * - ENOMEM 129 * - EIO 130 */ 131static int ext4_ext_dirty(handle_t *handle, struct inode *inode, 132 struct ext4_ext_path *path) 133{ 134 int err; 135 if (path->p_bh) { 136 /* path points to block */ 137 err = ext4_journal_dirty_metadata(handle, path->p_bh); 138 } else { 139 /* path points to leaf/index in inode body */ 140 err = ext4_mark_inode_dirty(handle, inode); 141 } 142 return err; 143} 144 145static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, 146 struct ext4_ext_path *path, 147 ext4_lblk_t block) 148{ 149 struct ext4_inode_info *ei = EXT4_I(inode); 150 ext4_fsblk_t bg_start; 151 ext4_fsblk_t last_block; 152 ext4_grpblk_t colour; 153 int depth; 154 155 if (path) { 156 struct ext4_extent *ex; 157 depth = path->p_depth; 158 159 /* try to predict block placement */ 160 ex = path[depth].p_ext; 161 if (ex) 162 return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block)); 163 164 /* it looks like index is empty; 165 * try to find starting block from index itself */ 166 if (path[depth].p_bh) 167 return path[depth].p_bh->b_blocknr; 168 } 169 170 /* OK. use inode's group */ 171 bg_start = (ei->i_block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) + 172 le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block); 173 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1; 174 175 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block) 176 colour = (current->pid % 16) * 177 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); 178 else 179 colour = (current->pid % 16) * ((last_block - bg_start) / 16); 180 return bg_start + colour + block; 181} 182 183static ext4_fsblk_t 184ext4_ext_new_block(handle_t *handle, struct inode *inode, 185 struct ext4_ext_path *path, 186 struct ext4_extent *ex, int *err) 187{ 188 ext4_fsblk_t goal, newblock; 189 190 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); 191 newblock = ext4_new_block(handle, inode, goal, err); 192 return newblock; 193} 194 195static int ext4_ext_space_block(struct inode *inode) 196{ 197 int size; 198 199 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 200 / sizeof(struct ext4_extent); 201#ifdef AGGRESSIVE_TEST 202 if (size > 6) 203 size = 6; 204#endif 205 return size; 206} 207 208static int ext4_ext_space_block_idx(struct inode *inode) 209{ 210 int size; 211 212 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 213 / sizeof(struct ext4_extent_idx); 214#ifdef AGGRESSIVE_TEST 215 if (size > 5) 216 size = 5; 217#endif 218 return size; 219} 220 221static int ext4_ext_space_root(struct inode *inode) 222{ 223 int size; 224 225 size = sizeof(EXT4_I(inode)->i_data); 226 size -= sizeof(struct ext4_extent_header); 227 size /= sizeof(struct ext4_extent); 228#ifdef AGGRESSIVE_TEST 229 if (size > 3) 230 size = 3; 231#endif 232 return size; 233} 234 235static int ext4_ext_space_root_idx(struct inode *inode) 236{ 237 int size; 238 239 size = sizeof(EXT4_I(inode)->i_data); 240 size -= sizeof(struct ext4_extent_header); 241 size /= sizeof(struct ext4_extent_idx); 242#ifdef AGGRESSIVE_TEST 243 if (size > 4) 244 size = 4; 245#endif 246 return size; 247} 248 249static int 250ext4_ext_max_entries(struct inode *inode, int depth) 251{ 252 int max; 253 254 if (depth == ext_depth(inode)) { 255 if (depth == 0) 256 max = ext4_ext_space_root(inode); 257 else 258 max = ext4_ext_space_root_idx(inode); 259 } else { 260 if (depth == 0) 261 max = ext4_ext_space_block(inode); 262 else 263 max = ext4_ext_space_block_idx(inode); 264 } 265 266 return max; 267} 268 269static int __ext4_ext_check_header(const char *function, struct inode *inode, 270 struct ext4_extent_header *eh, 271 int depth) 272{ 273 const char *error_msg; 274 int max = 0; 275 276 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { 277 error_msg = "invalid magic"; 278 goto corrupted; 279 } 280 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { 281 error_msg = "unexpected eh_depth"; 282 goto corrupted; 283 } 284 if (unlikely(eh->eh_max == 0)) { 285 error_msg = "invalid eh_max"; 286 goto corrupted; 287 } 288 max = ext4_ext_max_entries(inode, depth); 289 if (unlikely(le16_to_cpu(eh->eh_max) > max)) { 290 error_msg = "too large eh_max"; 291 goto corrupted; 292 } 293 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { 294 error_msg = "invalid eh_entries"; 295 goto corrupted; 296 } 297 return 0; 298 299corrupted: 300 ext4_error(inode->i_sb, function, 301 "bad header in inode #%lu: %s - magic %x, " 302 "entries %u, max %u(%u), depth %u(%u)", 303 inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic), 304 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), 305 max, le16_to_cpu(eh->eh_depth), depth); 306 307 return -EIO; 308} 309 310#define ext4_ext_check_header(inode, eh, depth) \ 311 __ext4_ext_check_header(__FUNCTION__, inode, eh, depth) 312 313#ifdef EXT_DEBUG 314static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) 315{ 316 int k, l = path->p_depth; 317 318 ext_debug("path:"); 319 for (k = 0; k <= l; k++, path++) { 320 if (path->p_idx) { 321 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), 322 idx_pblock(path->p_idx)); 323 } else if (path->p_ext) { 324 ext_debug(" %d:%d:%llu ", 325 le32_to_cpu(path->p_ext->ee_block), 326 ext4_ext_get_actual_len(path->p_ext), 327 ext_pblock(path->p_ext)); 328 } else 329 ext_debug(" []"); 330 } 331 ext_debug("\n"); 332} 333 334static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) 335{ 336 int depth = ext_depth(inode); 337 struct ext4_extent_header *eh; 338 struct ext4_extent *ex; 339 int i; 340 341 if (!path) 342 return; 343 344 eh = path[depth].p_hdr; 345 ex = EXT_FIRST_EXTENT(eh); 346 347 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { 348 ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block), 349 ext4_ext_get_actual_len(ex), ext_pblock(ex)); 350 } 351 ext_debug("\n"); 352} 353#else 354#define ext4_ext_show_path(inode,path) 355#define ext4_ext_show_leaf(inode,path) 356#endif 357 358void ext4_ext_drop_refs(struct ext4_ext_path *path) 359{ 360 int depth = path->p_depth; 361 int i; 362 363 for (i = 0; i <= depth; i++, path++) 364 if (path->p_bh) { 365 brelse(path->p_bh); 366 path->p_bh = NULL; 367 } 368} 369 370/* 371 * ext4_ext_binsearch_idx: 372 * binary search for the closest index of the given block 373 * the header must be checked before calling this 374 */ 375static void 376ext4_ext_binsearch_idx(struct inode *inode, 377 struct ext4_ext_path *path, ext4_lblk_t block) 378{ 379 struct ext4_extent_header *eh = path->p_hdr; 380 struct ext4_extent_idx *r, *l, *m; 381 382 383 ext_debug("binsearch for %u(idx): ", block); 384 385 l = EXT_FIRST_INDEX(eh) + 1; 386 r = EXT_LAST_INDEX(eh); 387 while (l <= r) { 388 m = l + (r - l) / 2; 389 if (block < le32_to_cpu(m->ei_block)) 390 r = m - 1; 391 else 392 l = m + 1; 393 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), 394 m, le32_to_cpu(m->ei_block), 395 r, le32_to_cpu(r->ei_block)); 396 } 397 398 path->p_idx = l - 1; 399 ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block), 400 idx_pblock(path->p_idx)); 401 402#ifdef CHECK_BINSEARCH 403 { 404 struct ext4_extent_idx *chix, *ix; 405 int k; 406 407 chix = ix = EXT_FIRST_INDEX(eh); 408 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { 409 if (k != 0 && 410 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { 411 printk("k=%d, ix=0x%p, first=0x%p\n", k, 412 ix, EXT_FIRST_INDEX(eh)); 413 printk("%u <= %u\n", 414 le32_to_cpu(ix->ei_block), 415 le32_to_cpu(ix[-1].ei_block)); 416 } 417 BUG_ON(k && le32_to_cpu(ix->ei_block) 418 <= le32_to_cpu(ix[-1].ei_block)); 419 if (block < le32_to_cpu(ix->ei_block)) 420 break; 421 chix = ix; 422 } 423 BUG_ON(chix != path->p_idx); 424 } 425#endif 426 427} 428 429/* 430 * ext4_ext_binsearch: 431 * binary search for closest extent of the given block 432 * the header must be checked before calling this 433 */ 434static void 435ext4_ext_binsearch(struct inode *inode, 436 struct ext4_ext_path *path, ext4_lblk_t block) 437{ 438 struct ext4_extent_header *eh = path->p_hdr; 439 struct ext4_extent *r, *l, *m; 440 441 if (eh->eh_entries == 0) { 442 /* 443 * this leaf is empty: 444 * we get such a leaf in split/add case 445 */ 446 return; 447 } 448 449 ext_debug("binsearch for %u: ", block); 450 451 l = EXT_FIRST_EXTENT(eh) + 1; 452 r = EXT_LAST_EXTENT(eh); 453 454 while (l <= r) { 455 m = l + (r - l) / 2; 456 if (block < le32_to_cpu(m->ee_block)) 457 r = m - 1; 458 else 459 l = m + 1; 460 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), 461 m, le32_to_cpu(m->ee_block), 462 r, le32_to_cpu(r->ee_block)); 463 } 464 465 path->p_ext = l - 1; 466 ext_debug(" -> %d:%llu:%d ", 467 le32_to_cpu(path->p_ext->ee_block), 468 ext_pblock(path->p_ext), 469 ext4_ext_get_actual_len(path->p_ext)); 470 471#ifdef CHECK_BINSEARCH 472 { 473 struct ext4_extent *chex, *ex; 474 int k; 475 476 chex = ex = EXT_FIRST_EXTENT(eh); 477 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { 478 BUG_ON(k && le32_to_cpu(ex->ee_block) 479 <= le32_to_cpu(ex[-1].ee_block)); 480 if (block < le32_to_cpu(ex->ee_block)) 481 break; 482 chex = ex; 483 } 484 BUG_ON(chex != path->p_ext); 485 } 486#endif 487 488} 489 490int ext4_ext_tree_init(handle_t *handle, struct inode *inode) 491{ 492 struct ext4_extent_header *eh; 493 494 eh = ext_inode_hdr(inode); 495 eh->eh_depth = 0; 496 eh->eh_entries = 0; 497 eh->eh_magic = EXT4_EXT_MAGIC; 498 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode)); 499 ext4_mark_inode_dirty(handle, inode); 500 ext4_ext_invalidate_cache(inode); 501 return 0; 502} 503 504struct ext4_ext_path * 505ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, 506 struct ext4_ext_path *path) 507{ 508 struct ext4_extent_header *eh; 509 struct buffer_head *bh; 510 short int depth, i, ppos = 0, alloc = 0; 511 512 eh = ext_inode_hdr(inode); 513 depth = ext_depth(inode); 514 if (ext4_ext_check_header(inode, eh, depth)) 515 return ERR_PTR(-EIO); 516 517 518 /* account possible depth increase */ 519 if (!path) { 520 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2), 521 GFP_NOFS); 522 if (!path) 523 return ERR_PTR(-ENOMEM); 524 alloc = 1; 525 } 526 path[0].p_hdr = eh; 527 528 i = depth; 529 /* walk through the tree */ 530 while (i) { 531 ext_debug("depth %d: num %d, max %d\n", 532 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); 533 534 ext4_ext_binsearch_idx(inode, path + ppos, block); 535 path[ppos].p_block = idx_pblock(path[ppos].p_idx); 536 path[ppos].p_depth = i; 537 path[ppos].p_ext = NULL; 538 539 bh = sb_bread(inode->i_sb, path[ppos].p_block); 540 if (!bh) 541 goto err; 542 543 eh = ext_block_hdr(bh); 544 ppos++; 545 BUG_ON(ppos > depth); 546 path[ppos].p_bh = bh; 547 path[ppos].p_hdr = eh; 548 i--; 549 550 if (ext4_ext_check_header(inode, eh, i)) 551 goto err; 552 } 553 554 path[ppos].p_depth = i; 555 path[ppos].p_hdr = eh; 556 path[ppos].p_ext = NULL; 557 path[ppos].p_idx = NULL; 558 559 /* find extent */ 560 ext4_ext_binsearch(inode, path + ppos, block); 561 562 ext4_ext_show_path(inode, path); 563 564 return path; 565 566err: 567 ext4_ext_drop_refs(path); 568 if (alloc) 569 kfree(path); 570 return ERR_PTR(-EIO); 571} 572 573/* 574 * ext4_ext_insert_index: 575 * insert new index [@logical;@ptr] into the block at @curp; 576 * check where to insert: before @curp or after @curp 577 */ 578static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, 579 struct ext4_ext_path *curp, 580 int logical, ext4_fsblk_t ptr) 581{ 582 struct ext4_extent_idx *ix; 583 int len, err; 584 585 err = ext4_ext_get_access(handle, inode, curp); 586 if (err) 587 return err; 588 589 BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block)); 590 len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx; 591 if (logical > le32_to_cpu(curp->p_idx->ei_block)) { 592 /* insert after */ 593 if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) { 594 len = (len - 1) * sizeof(struct ext4_extent_idx); 595 len = len < 0 ? 0 : len; 596 ext_debug("insert new index %d after: %llu. " 597 "move %d from 0x%p to 0x%p\n", 598 logical, ptr, len, 599 (curp->p_idx + 1), (curp->p_idx + 2)); 600 memmove(curp->p_idx + 2, curp->p_idx + 1, len); 601 } 602 ix = curp->p_idx + 1; 603 } else { 604 /* insert before */ 605 len = len * sizeof(struct ext4_extent_idx); 606 len = len < 0 ? 0 : len; 607 ext_debug("insert new index %d before: %llu. " 608 "move %d from 0x%p to 0x%p\n", 609 logical, ptr, len, 610 curp->p_idx, (curp->p_idx + 1)); 611 memmove(curp->p_idx + 1, curp->p_idx, len); 612 ix = curp->p_idx; 613 } 614 615 ix->ei_block = cpu_to_le32(logical); 616 ext4_idx_store_pblock(ix, ptr); 617 curp->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(curp->p_hdr->eh_entries)+1); 618 619 BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries) 620 > le16_to_cpu(curp->p_hdr->eh_max)); 621 BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr)); 622 623 err = ext4_ext_dirty(handle, inode, curp); 624 ext4_std_error(inode->i_sb, err); 625 626 return err; 627} 628 629/* 630 * ext4_ext_split: 631 * inserts new subtree into the path, using free index entry 632 * at depth @at: 633 * - allocates all needed blocks (new leaf and all intermediate index blocks) 634 * - makes decision where to split 635 * - moves remaining extents and index entries (right to the split point) 636 * into the newly allocated blocks 637 * - initializes subtree 638 */ 639static int ext4_ext_split(handle_t *handle, struct inode *inode, 640 struct ext4_ext_path *path, 641 struct ext4_extent *newext, int at) 642{ 643 struct buffer_head *bh = NULL; 644 int depth = ext_depth(inode); 645 struct ext4_extent_header *neh; 646 struct ext4_extent_idx *fidx; 647 struct ext4_extent *ex; 648 int i = at, k, m, a; 649 ext4_fsblk_t newblock, oldblock; 650 __le32 border; 651 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ 652 int err = 0; 653 654 /* make decision: where to split? */ 655 /* FIXME: now decision is simplest: at current extent */ 656 657 /* if current leaf will be split, then we should use 658 * border from split point */ 659 BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr)); 660 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { 661 border = path[depth].p_ext[1].ee_block; 662 ext_debug("leaf will be split." 663 " next leaf starts at %d\n", 664 le32_to_cpu(border)); 665 } else { 666 border = newext->ee_block; 667 ext_debug("leaf will be added." 668 " next leaf starts at %d\n", 669 le32_to_cpu(border)); 670 } 671 672 /* 673 * If error occurs, then we break processing 674 * and mark filesystem read-only. index won't 675 * be inserted and tree will be in consistent 676 * state. Next mount will repair buffers too. 677 */ 678 679 /* 680 * Get array to track all allocated blocks. 681 * We need this to handle errors and free blocks 682 * upon them. 683 */ 684 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); 685 if (!ablocks) 686 return -ENOMEM; 687 688 /* allocate all needed blocks */ 689 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); 690 for (a = 0; a < depth - at; a++) { 691 newblock = ext4_ext_new_block(handle, inode, path, newext, &err); 692 if (newblock == 0) 693 goto cleanup; 694 ablocks[a] = newblock; 695 } 696 697 /* initialize new leaf */ 698 newblock = ablocks[--a]; 699 BUG_ON(newblock == 0); 700 bh = sb_getblk(inode->i_sb, newblock); 701 if (!bh) { 702 err = -EIO; 703 goto cleanup; 704 } 705 lock_buffer(bh); 706 707 err = ext4_journal_get_create_access(handle, bh); 708 if (err) 709 goto cleanup; 710 711 neh = ext_block_hdr(bh); 712 neh->eh_entries = 0; 713 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); 714 neh->eh_magic = EXT4_EXT_MAGIC; 715 neh->eh_depth = 0; 716 ex = EXT_FIRST_EXTENT(neh); 717 718 /* move remainder of path[depth] to the new leaf */ 719 BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max); 720 /* start copy from next extent */ 721 /* TODO: we could do it by single memmove */ 722 m = 0; 723 path[depth].p_ext++; 724 while (path[depth].p_ext <= 725 EXT_MAX_EXTENT(path[depth].p_hdr)) { 726 ext_debug("move %d:%llu:%d in new leaf %llu\n", 727 le32_to_cpu(path[depth].p_ext->ee_block), 728 ext_pblock(path[depth].p_ext), 729 ext4_ext_get_actual_len(path[depth].p_ext), 730 newblock); 731 /*memmove(ex++, path[depth].p_ext++, 732 sizeof(struct ext4_extent)); 733 neh->eh_entries++;*/ 734 path[depth].p_ext++; 735 m++; 736 } 737 if (m) { 738 memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m); 739 neh->eh_entries = cpu_to_le16(le16_to_cpu(neh->eh_entries)+m); 740 } 741 742 set_buffer_uptodate(bh); 743 unlock_buffer(bh); 744 745 err = ext4_journal_dirty_metadata(handle, bh); 746 if (err) 747 goto cleanup; 748 brelse(bh); 749 bh = NULL; 750 751 /* correct old leaf */ 752 if (m) { 753 err = ext4_ext_get_access(handle, inode, path + depth); 754 if (err) 755 goto cleanup; 756 path[depth].p_hdr->eh_entries = 757 cpu_to_le16(le16_to_cpu(path[depth].p_hdr->eh_entries)-m); 758 err = ext4_ext_dirty(handle, inode, path + depth); 759 if (err) 760 goto cleanup; 761 762 } 763 764 /* create intermediate indexes */ 765 k = depth - at - 1; 766 BUG_ON(k < 0); 767 if (k) 768 ext_debug("create %d intermediate indices\n", k); 769 /* insert new index into current index block */ 770 /* current depth stored in i var */ 771 i = depth - 1; 772 while (k--) { 773 oldblock = newblock; 774 newblock = ablocks[--a]; 775 bh = sb_getblk(inode->i_sb, newblock); 776 if (!bh) { 777 err = -EIO; 778 goto cleanup; 779 } 780 lock_buffer(bh); 781 782 err = ext4_journal_get_create_access(handle, bh); 783 if (err) 784 goto cleanup; 785 786 neh = ext_block_hdr(bh); 787 neh->eh_entries = cpu_to_le16(1); 788 neh->eh_magic = EXT4_EXT_MAGIC; 789 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); 790 neh->eh_depth = cpu_to_le16(depth - i); 791 fidx = EXT_FIRST_INDEX(neh); 792 fidx->ei_block = border; 793 ext4_idx_store_pblock(fidx, oldblock); 794 795 ext_debug("int.index at %d (block %llu): %u -> %llu\n", 796 i, newblock, le32_to_cpu(border), oldblock); 797 /* copy indexes */ 798 m = 0; 799 path[i].p_idx++; 800 801 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, 802 EXT_MAX_INDEX(path[i].p_hdr)); 803 BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) != 804 EXT_LAST_INDEX(path[i].p_hdr)); 805 while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) { 806 ext_debug("%d: move %d:%llu in new index %llu\n", i, 807 le32_to_cpu(path[i].p_idx->ei_block), 808 idx_pblock(path[i].p_idx), 809 newblock); 810 /*memmove(++fidx, path[i].p_idx++, 811 sizeof(struct ext4_extent_idx)); 812 neh->eh_entries++; 813 BUG_ON(neh->eh_entries > neh->eh_max);*/ 814 path[i].p_idx++; 815 m++; 816 } 817 if (m) { 818 memmove(++fidx, path[i].p_idx - m, 819 sizeof(struct ext4_extent_idx) * m); 820 neh->eh_entries = 821 cpu_to_le16(le16_to_cpu(neh->eh_entries) + m); 822 } 823 set_buffer_uptodate(bh); 824 unlock_buffer(bh); 825 826 err = ext4_journal_dirty_metadata(handle, bh); 827 if (err) 828 goto cleanup; 829 brelse(bh); 830 bh = NULL; 831 832 /* correct old index */ 833 if (m) { 834 err = ext4_ext_get_access(handle, inode, path + i); 835 if (err) 836 goto cleanup; 837 path[i].p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path[i].p_hdr->eh_entries)-m); 838 err = ext4_ext_dirty(handle, inode, path + i); 839 if (err) 840 goto cleanup; 841 } 842 843 i--; 844 } 845 846 /* insert new index */ 847 err = ext4_ext_insert_index(handle, inode, path + at, 848 le32_to_cpu(border), newblock); 849 850cleanup: 851 if (bh) { 852 if (buffer_locked(bh)) 853 unlock_buffer(bh); 854 brelse(bh); 855 } 856 857 if (err) { 858 /* free all allocated blocks in error case */ 859 for (i = 0; i < depth; i++) { 860 if (!ablocks[i]) 861 continue; 862 ext4_free_blocks(handle, inode, ablocks[i], 1, 1); 863 } 864 } 865 kfree(ablocks); 866 867 return err; 868} 869 870/* 871 * ext4_ext_grow_indepth: 872 * implements tree growing procedure: 873 * - allocates new block 874 * - moves top-level data (index block or leaf) into the new block 875 * - initializes new top-level, creating index that points to the 876 * just created block 877 */ 878static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, 879 struct ext4_ext_path *path, 880 struct ext4_extent *newext) 881{ 882 struct ext4_ext_path *curp = path; 883 struct ext4_extent_header *neh; 884 struct ext4_extent_idx *fidx; 885 struct buffer_head *bh; 886 ext4_fsblk_t newblock; 887 int err = 0; 888 889 newblock = ext4_ext_new_block(handle, inode, path, newext, &err); 890 if (newblock == 0) 891 return err; 892 893 bh = sb_getblk(inode->i_sb, newblock); 894 if (!bh) { 895 err = -EIO; 896 ext4_std_error(inode->i_sb, err); 897 return err; 898 } 899 lock_buffer(bh); 900 901 err = ext4_journal_get_create_access(handle, bh); 902 if (err) { 903 unlock_buffer(bh); 904 goto out; 905 } 906 907 /* move top-level index/leaf into new block */ 908 memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data)); 909 910 /* set size of new block */ 911 neh = ext_block_hdr(bh); 912 /* old root could have indexes or leaves 913 * so calculate e_max right way */ 914 if (ext_depth(inode)) 915 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); 916 else 917 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); 918 neh->eh_magic = EXT4_EXT_MAGIC; 919 set_buffer_uptodate(bh); 920 unlock_buffer(bh); 921 922 err = ext4_journal_dirty_metadata(handle, bh); 923 if (err) 924 goto out; 925 926 /* create index in new top-level index: num,max,pointer */ 927 err = ext4_ext_get_access(handle, inode, curp); 928 if (err) 929 goto out; 930 931 curp->p_hdr->eh_magic = EXT4_EXT_MAGIC; 932 curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode)); 933 curp->p_hdr->eh_entries = cpu_to_le16(1); 934 curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr); 935 936 if (path[0].p_hdr->eh_depth) 937 curp->p_idx->ei_block = 938 EXT_FIRST_INDEX(path[0].p_hdr)->ei_block; 939 else 940 curp->p_idx->ei_block = 941 EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block; 942 ext4_idx_store_pblock(curp->p_idx, newblock); 943 944 neh = ext_inode_hdr(inode); 945 fidx = EXT_FIRST_INDEX(neh); 946 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", 947 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), 948 le32_to_cpu(fidx->ei_block), idx_pblock(fidx)); 949 950 neh->eh_depth = cpu_to_le16(path->p_depth + 1); 951 err = ext4_ext_dirty(handle, inode, curp); 952out: 953 brelse(bh); 954 955 return err; 956} 957 958/* 959 * ext4_ext_create_new_leaf: 960 * finds empty index and adds new leaf. 961 * if no free index is found, then it requests in-depth growing. 962 */ 963static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, 964 struct ext4_ext_path *path, 965 struct ext4_extent *newext) 966{ 967 struct ext4_ext_path *curp; 968 int depth, i, err = 0; 969 970repeat: 971 i = depth = ext_depth(inode); 972 973 /* walk up to the tree and look for free index entry */ 974 curp = path + depth; 975 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { 976 i--; 977 curp--; 978 } 979 980 /* we use already allocated block for index block, 981 * so subsequent data blocks should be contiguous */ 982 if (EXT_HAS_FREE_INDEX(curp)) { 983 /* if we found index with free entry, then use that 984 * entry: create all needed subtree and add new leaf */ 985 err = ext4_ext_split(handle, inode, path, newext, i); 986 987 /* refill path */ 988 ext4_ext_drop_refs(path); 989 path = ext4_ext_find_extent(inode, 990 (ext4_lblk_t)le32_to_cpu(newext->ee_block), 991 path); 992 if (IS_ERR(path)) 993 err = PTR_ERR(path); 994 } else { 995 /* tree is full, time to grow in depth */ 996 err = ext4_ext_grow_indepth(handle, inode, path, newext); 997 if (err) 998 goto out; 999 1000 /* refill path */ 1001 ext4_ext_drop_refs(path); 1002 path = ext4_ext_find_extent(inode, 1003 (ext4_lblk_t)le32_to_cpu(newext->ee_block), 1004 path); 1005 if (IS_ERR(path)) { 1006 err = PTR_ERR(path); 1007 goto out; 1008 } 1009 1010 /* 1011 * only first (depth 0 -> 1) produces free space; 1012 * in all other cases we have to split the grown tree 1013 */ 1014 depth = ext_depth(inode); 1015 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { 1016 /* now we need to split */ 1017 goto repeat; 1018 } 1019 } 1020 1021out: 1022 return err; 1023} 1024 1025/* 1026 * search the closest allocated block to the left for *logical 1027 * and returns it at @logical + it's physical address at @phys 1028 * if *logical is the smallest allocated block, the function 1029 * returns 0 at @phys 1030 * return value contains 0 (success) or error code 1031 */ 1032int 1033ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path, 1034 ext4_lblk_t *logical, ext4_fsblk_t *phys) 1035{ 1036 struct ext4_extent_idx *ix; 1037 struct ext4_extent *ex; 1038 int depth, ee_len; 1039 1040 BUG_ON(path == NULL); 1041 depth = path->p_depth; 1042 *phys = 0; 1043 1044 if (depth == 0 && path->p_ext == NULL) 1045 return 0; 1046 1047 /* usually extent in the path covers blocks smaller 1048 * then *logical, but it can be that extent is the 1049 * first one in the file */ 1050 1051 ex = path[depth].p_ext; 1052 ee_len = ext4_ext_get_actual_len(ex); 1053 if (*logical < le32_to_cpu(ex->ee_block)) { 1054 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex); 1055 while (--depth >= 0) { 1056 ix = path[depth].p_idx; 1057 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr)); 1058 } 1059 return 0; 1060 } 1061 1062 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len)); 1063 1064 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; 1065 *phys = ext_pblock(ex) + ee_len - 1; 1066 return 0; 1067} 1068 1069/* 1070 * search the closest allocated block to the right for *logical 1071 * and returns it at @logical + it's physical address at @phys 1072 * if *logical is the smallest allocated block, the function 1073 * returns 0 at @phys 1074 * return value contains 0 (success) or error code 1075 */ 1076int 1077ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, 1078 ext4_lblk_t *logical, ext4_fsblk_t *phys) 1079{ 1080 struct buffer_head *bh = NULL; 1081 struct ext4_extent_header *eh; 1082 struct ext4_extent_idx *ix; 1083 struct ext4_extent *ex; 1084 ext4_fsblk_t block; 1085 int depth, ee_len; 1086 1087 BUG_ON(path == NULL); 1088 depth = path->p_depth; 1089 *phys = 0; 1090 1091 if (depth == 0 && path->p_ext == NULL) 1092 return 0; 1093 1094 /* usually extent in the path covers blocks smaller 1095 * then *logical, but it can be that extent is the 1096 * first one in the file */ 1097 1098 ex = path[depth].p_ext; 1099 ee_len = ext4_ext_get_actual_len(ex); 1100 if (*logical < le32_to_cpu(ex->ee_block)) { 1101 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex); 1102 while (--depth >= 0) { 1103 ix = path[depth].p_idx; 1104 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr)); 1105 } 1106 *logical = le32_to_cpu(ex->ee_block); 1107 *phys = ext_pblock(ex); 1108 return 0; 1109 } 1110 1111 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len)); 1112 1113 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { 1114 /* next allocated block in this leaf */ 1115 ex++; 1116 *logical = le32_to_cpu(ex->ee_block); 1117 *phys = ext_pblock(ex); 1118 return 0; 1119 } 1120 1121 /* go up and search for index to the right */ 1122 while (--depth >= 0) { 1123 ix = path[depth].p_idx; 1124 if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) 1125 break; 1126 } 1127 1128 if (depth < 0) { 1129 /* we've gone up to the root and 1130 * found no index to the right */ 1131 return 0; 1132 } 1133 1134 /* we've found index to the right, let's 1135 * follow it and find the closest allocated 1136 * block to the right */ 1137 ix++; 1138 block = idx_pblock(ix); 1139 while (++depth < path->p_depth) { 1140 bh = sb_bread(inode->i_sb, block); 1141 if (bh == NULL) 1142 return -EIO; 1143 eh = ext_block_hdr(bh); 1144 if (ext4_ext_check_header(inode, eh, depth)) { 1145 put_bh(bh); 1146 return -EIO; 1147 } 1148 ix = EXT_FIRST_INDEX(eh); 1149 block = idx_pblock(ix); 1150 put_bh(bh); 1151 } 1152 1153 bh = sb_bread(inode->i_sb, block); 1154 if (bh == NULL) 1155 return -EIO; 1156 eh = ext_block_hdr(bh); 1157 if (ext4_ext_check_header(inode, eh, path->p_depth - depth)) { 1158 put_bh(bh); 1159 return -EIO; 1160 } 1161 ex = EXT_FIRST_EXTENT(eh); 1162 *logical = le32_to_cpu(ex->ee_block); 1163 *phys = ext_pblock(ex); 1164 put_bh(bh); 1165 return 0; 1166 1167} 1168 1169/* 1170 * ext4_ext_next_allocated_block: 1171 * returns allocated block in subsequent extent or EXT_MAX_BLOCK. 1172 * NOTE: it considers block number from index entry as 1173 * allocated block. Thus, index entries have to be consistent 1174 * with leaves. 1175 */ 1176static ext4_lblk_t 1177ext4_ext_next_allocated_block(struct ext4_ext_path *path) 1178{ 1179 int depth; 1180 1181 BUG_ON(path == NULL); 1182 depth = path->p_depth; 1183 1184 if (depth == 0 && path->p_ext == NULL) 1185 return EXT_MAX_BLOCK; 1186 1187 while (depth >= 0) { 1188 if (depth == path->p_depth) { 1189 /* leaf */ 1190 if (path[depth].p_ext != 1191 EXT_LAST_EXTENT(path[depth].p_hdr)) 1192 return le32_to_cpu(path[depth].p_ext[1].ee_block); 1193 } else { 1194 /* index */ 1195 if (path[depth].p_idx != 1196 EXT_LAST_INDEX(path[depth].p_hdr)) 1197 return le32_to_cpu(path[depth].p_idx[1].ei_block); 1198 } 1199 depth--; 1200 } 1201 1202 return EXT_MAX_BLOCK; 1203} 1204 1205/* 1206 * ext4_ext_next_leaf_block: 1207 * returns first allocated block from next leaf or EXT_MAX_BLOCK 1208 */ 1209static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode, 1210 struct ext4_ext_path *path) 1211{ 1212 int depth; 1213 1214 BUG_ON(path == NULL); 1215 depth = path->p_depth; 1216 1217 /* zero-tree has no leaf blocks at all */ 1218 if (depth == 0) 1219 return EXT_MAX_BLOCK; 1220 1221 /* go to index block */ 1222 depth--; 1223 1224 while (depth >= 0) { 1225 if (path[depth].p_idx != 1226 EXT_LAST_INDEX(path[depth].p_hdr)) 1227 return (ext4_lblk_t) 1228 le32_to_cpu(path[depth].p_idx[1].ei_block); 1229 depth--; 1230 } 1231 1232 return EXT_MAX_BLOCK; 1233} 1234 1235/* 1236 * ext4_ext_correct_indexes: 1237 * if leaf gets modified and modified extent is first in the leaf, 1238 * then we have to correct all indexes above. 1239 * TODO: do we need to correct tree in all cases? 1240 */ 1241static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, 1242 struct ext4_ext_path *path) 1243{ 1244 struct ext4_extent_header *eh; 1245 int depth = ext_depth(inode); 1246 struct ext4_extent *ex; 1247 __le32 border; 1248 int k, err = 0; 1249 1250 eh = path[depth].p_hdr; 1251 ex = path[depth].p_ext; 1252 BUG_ON(ex == NULL); 1253 BUG_ON(eh == NULL); 1254 1255 if (depth == 0) { 1256 /* there is no tree at all */ 1257 return 0; 1258 } 1259 1260 if (ex != EXT_FIRST_EXTENT(eh)) { 1261 /* we correct tree if first leaf got modified only */ 1262 return 0; 1263 } 1264 1265 /* 1266 * TODO: we need correction if border is smaller than current one 1267 */ 1268 k = depth - 1; 1269 border = path[depth].p_ext->ee_block; 1270 err = ext4_ext_get_access(handle, inode, path + k); 1271 if (err) 1272 return err; 1273 path[k].p_idx->ei_block = border; 1274 err = ext4_ext_dirty(handle, inode, path + k); 1275 if (err) 1276 return err; 1277 1278 while (k--) { 1279 /* change all left-side indexes */ 1280 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) 1281 break; 1282 err = ext4_ext_get_access(handle, inode, path + k); 1283 if (err) 1284 break; 1285 path[k].p_idx->ei_block = border; 1286 err = ext4_ext_dirty(handle, inode, path + k); 1287 if (err) 1288 break; 1289 } 1290 1291 return err; 1292} 1293 1294static int 1295ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, 1296 struct ext4_extent *ex2) 1297{ 1298 unsigned short ext1_ee_len, ext2_ee_len, max_len; 1299 1300 /* 1301 * Make sure that either both extents are uninitialized, or 1302 * both are _not_. 1303 */ 1304 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2)) 1305 return 0; 1306 1307 if (ext4_ext_is_uninitialized(ex1)) 1308 max_len = EXT_UNINIT_MAX_LEN; 1309 else 1310 max_len = EXT_INIT_MAX_LEN; 1311 1312 ext1_ee_len = ext4_ext_get_actual_len(ex1); 1313 ext2_ee_len = ext4_ext_get_actual_len(ex2); 1314 1315 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != 1316 le32_to_cpu(ex2->ee_block)) 1317 return 0; 1318 1319 /* 1320 * To allow future support for preallocated extents to be added 1321 * as an RO_COMPAT feature, refuse to merge to extents if 1322 * this can result in the top bit of ee_len being set. 1323 */ 1324 if (ext1_ee_len + ext2_ee_len > max_len) 1325 return 0; 1326#ifdef AGGRESSIVE_TEST 1327 if (ext1_ee_len >= 4) 1328 return 0; 1329#endif 1330 1331 if (ext_pblock(ex1) + ext1_ee_len == ext_pblock(ex2)) 1332 return 1; 1333 return 0; 1334} 1335 1336/* 1337 * This function tries to merge the "ex" extent to the next extent in the tree. 1338 * It always tries to merge towards right. If you want to merge towards 1339 * left, pass "ex - 1" as argument instead of "ex". 1340 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns 1341 * 1 if they got merged. 1342 */ 1343int ext4_ext_try_to_merge(struct inode *inode, 1344 struct ext4_ext_path *path, 1345 struct ext4_extent *ex) 1346{ 1347 struct ext4_extent_header *eh; 1348 unsigned int depth, len; 1349 int merge_done = 0; 1350 int uninitialized = 0; 1351 1352 depth = ext_depth(inode); 1353 BUG_ON(path[depth].p_hdr == NULL); 1354 eh = path[depth].p_hdr; 1355 1356 while (ex < EXT_LAST_EXTENT(eh)) { 1357 if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) 1358 break; 1359 /* merge with next extent! */ 1360 if (ext4_ext_is_uninitialized(ex)) 1361 uninitialized = 1; 1362 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 1363 + ext4_ext_get_actual_len(ex + 1)); 1364 if (uninitialized) 1365 ext4_ext_mark_uninitialized(ex); 1366 1367 if (ex + 1 < EXT_LAST_EXTENT(eh)) { 1368 len = (EXT_LAST_EXTENT(eh) - ex - 1) 1369 * sizeof(struct ext4_extent); 1370 memmove(ex + 1, ex + 2, len); 1371 } 1372 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries) - 1); 1373 merge_done = 1; 1374 WARN_ON(eh->eh_entries == 0); 1375 if (!eh->eh_entries) 1376 ext4_error(inode->i_sb, "ext4_ext_try_to_merge", 1377 "inode#%lu, eh->eh_entries = 0!", inode->i_ino); 1378 } 1379 1380 return merge_done; 1381} 1382 1383/* 1384 * check if a portion of the "newext" extent overlaps with an 1385 * existing extent. 1386 * 1387 * If there is an overlap discovered, it updates the length of the newext 1388 * such that there will be no overlap, and then returns 1. 1389 * If there is no overlap found, it returns 0. 1390 */ 1391unsigned int ext4_ext_check_overlap(struct inode *inode, 1392 struct ext4_extent *newext, 1393 struct ext4_ext_path *path) 1394{ 1395 ext4_lblk_t b1, b2; 1396 unsigned int depth, len1; 1397 unsigned int ret = 0; 1398 1399 b1 = le32_to_cpu(newext->ee_block); 1400 len1 = ext4_ext_get_actual_len(newext); 1401 depth = ext_depth(inode); 1402 if (!path[depth].p_ext) 1403 goto out; 1404 b2 = le32_to_cpu(path[depth].p_ext->ee_block); 1405 1406 /* 1407 * get the next allocated block if the extent in the path 1408 * is before the requested block(s) 1409 */ 1410 if (b2 < b1) { 1411 b2 = ext4_ext_next_allocated_block(path); 1412 if (b2 == EXT_MAX_BLOCK) 1413 goto out; 1414 } 1415 1416 /* check for wrap through zero on extent logical start block*/ 1417 if (b1 + len1 < b1) { 1418 len1 = EXT_MAX_BLOCK - b1; 1419 newext->ee_len = cpu_to_le16(len1); 1420 ret = 1; 1421 } 1422 1423 /* check for overlap */ 1424 if (b1 + len1 > b2) { 1425 newext->ee_len = cpu_to_le16(b2 - b1); 1426 ret = 1; 1427 } 1428out: 1429 return ret; 1430} 1431 1432/* 1433 * ext4_ext_insert_extent: 1434 * tries to merge requsted extent into the existing extent or 1435 * inserts requested extent as new one into the tree, 1436 * creating new leaf in the no-space case. 1437 */ 1438int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, 1439 struct ext4_ext_path *path, 1440 struct ext4_extent *newext) 1441{ 1442 struct ext4_extent_header * eh; 1443 struct ext4_extent *ex, *fex; 1444 struct ext4_extent *nearex; /* nearest extent */ 1445 struct ext4_ext_path *npath = NULL; 1446 int depth, len, err; 1447 ext4_lblk_t next; 1448 unsigned uninitialized = 0; 1449 1450 BUG_ON(ext4_ext_get_actual_len(newext) == 0); 1451 depth = ext_depth(inode); 1452 ex = path[depth].p_ext; 1453 BUG_ON(path[depth].p_hdr == NULL); 1454 1455 /* try to insert block into found extent and return */ 1456 if (ex && ext4_can_extents_be_merged(inode, ex, newext)) { 1457 ext_debug("append %d block to %d:%d (from %llu)\n", 1458 ext4_ext_get_actual_len(newext), 1459 le32_to_cpu(ex->ee_block), 1460 ext4_ext_get_actual_len(ex), ext_pblock(ex)); 1461 err = ext4_ext_get_access(handle, inode, path + depth); 1462 if (err) 1463 return err; 1464 1465 /* 1466 * ext4_can_extents_be_merged should have checked that either 1467 * both extents are uninitialized, or both aren't. Thus we 1468 * need to check only one of them here. 1469 */ 1470 if (ext4_ext_is_uninitialized(ex)) 1471 uninitialized = 1; 1472 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 1473 + ext4_ext_get_actual_len(newext)); 1474 if (uninitialized) 1475 ext4_ext_mark_uninitialized(ex); 1476 eh = path[depth].p_hdr; 1477 nearex = ex; 1478 goto merge; 1479 } 1480 1481repeat: 1482 depth = ext_depth(inode); 1483 eh = path[depth].p_hdr; 1484 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) 1485 goto has_space; 1486 1487 /* probably next leaf has space for us? */ 1488 fex = EXT_LAST_EXTENT(eh); 1489 next = ext4_ext_next_leaf_block(inode, path); 1490 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block) 1491 && next != EXT_MAX_BLOCK) { 1492 ext_debug("next leaf block - %d\n", next); 1493 BUG_ON(npath != NULL); 1494 npath = ext4_ext_find_extent(inode, next, NULL); 1495 if (IS_ERR(npath)) 1496 return PTR_ERR(npath); 1497 BUG_ON(npath->p_depth != path->p_depth); 1498 eh = npath[depth].p_hdr; 1499 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { 1500 ext_debug("next leaf isnt full(%d)\n", 1501 le16_to_cpu(eh->eh_entries)); 1502 path = npath; 1503 goto repeat; 1504 } 1505 ext_debug("next leaf has no free space(%d,%d)\n", 1506 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); 1507 } 1508 1509 /* 1510 * There is no free space in the found leaf. 1511 * We're gonna add a new leaf in the tree. 1512 */ 1513 err = ext4_ext_create_new_leaf(handle, inode, path, newext); 1514 if (err) 1515 goto cleanup; 1516 depth = ext_depth(inode); 1517 eh = path[depth].p_hdr; 1518 1519has_space: 1520 nearex = path[depth].p_ext; 1521 1522 err = ext4_ext_get_access(handle, inode, path + depth); 1523 if (err) 1524 goto cleanup; 1525 1526 if (!nearex) { 1527 /* there is no extent in this leaf, create first one */ 1528 ext_debug("first extent in the leaf: %d:%llu:%d\n", 1529 le32_to_cpu(newext->ee_block), 1530 ext_pblock(newext), 1531 ext4_ext_get_actual_len(newext)); 1532 path[depth].p_ext = EXT_FIRST_EXTENT(eh); 1533 } else if (le32_to_cpu(newext->ee_block) 1534 > le32_to_cpu(nearex->ee_block)) { 1535/* BUG_ON(newext->ee_block == nearex->ee_block); */ 1536 if (nearex != EXT_LAST_EXTENT(eh)) { 1537 len = EXT_MAX_EXTENT(eh) - nearex; 1538 len = (len - 1) * sizeof(struct ext4_extent); 1539 len = len < 0 ? 0 : len; 1540 ext_debug("insert %d:%llu:%d after: nearest 0x%p, " 1541 "move %d from 0x%p to 0x%p\n", 1542 le32_to_cpu(newext->ee_block), 1543 ext_pblock(newext), 1544 ext4_ext_get_actual_len(newext), 1545 nearex, len, nearex + 1, nearex + 2); 1546 memmove(nearex + 2, nearex + 1, len); 1547 } 1548 path[depth].p_ext = nearex + 1; 1549 } else { 1550 BUG_ON(newext->ee_block == nearex->ee_block); 1551 len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent); 1552 len = len < 0 ? 0 : len; 1553 ext_debug("insert %d:%llu:%d before: nearest 0x%p, " 1554 "move %d from 0x%p to 0x%p\n", 1555 le32_to_cpu(newext->ee_block), 1556 ext_pblock(newext), 1557 ext4_ext_get_actual_len(newext), 1558 nearex, len, nearex + 1, nearex + 2); 1559 memmove(nearex + 1, nearex, len); 1560 path[depth].p_ext = nearex; 1561 } 1562 1563 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)+1); 1564 nearex = path[depth].p_ext; 1565 nearex->ee_block = newext->ee_block; 1566 ext4_ext_store_pblock(nearex, ext_pblock(newext)); 1567 nearex->ee_len = newext->ee_len; 1568 1569merge: 1570 /* try to merge extents to the right */ 1571 ext4_ext_try_to_merge(inode, path, nearex); 1572 1573 /* try to merge extents to the left */ 1574 1575 /* time to correct all indexes above */ 1576 err = ext4_ext_correct_indexes(handle, inode, path); 1577 if (err) 1578 goto cleanup; 1579 1580 err = ext4_ext_dirty(handle, inode, path + depth); 1581 1582cleanup: 1583 if (npath) { 1584 ext4_ext_drop_refs(npath); 1585 kfree(npath); 1586 } 1587 ext4_ext_tree_changed(inode); 1588 ext4_ext_invalidate_cache(inode); 1589 return err; 1590} 1591 1592static void 1593ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block, 1594 __u32 len, ext4_fsblk_t start, int type) 1595{ 1596 struct ext4_ext_cache *cex; 1597 BUG_ON(len == 0); 1598 cex = &EXT4_I(inode)->i_cached_extent; 1599 cex->ec_type = type; 1600 cex->ec_block = block; 1601 cex->ec_len = len; 1602 cex->ec_start = start; 1603} 1604 1605/* 1606 * ext4_ext_put_gap_in_cache: 1607 * calculate boundaries of the gap that the requested block fits into 1608 * and cache this gap 1609 */ 1610static void 1611ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, 1612 ext4_lblk_t block) 1613{ 1614 int depth = ext_depth(inode); 1615 unsigned long len; 1616 ext4_lblk_t lblock; 1617 struct ext4_extent *ex; 1618 1619 ex = path[depth].p_ext; 1620 if (ex == NULL) { 1621 /* there is no extent yet, so gap is [0;-] */ 1622 lblock = 0; 1623 len = EXT_MAX_BLOCK; 1624 ext_debug("cache gap(whole file):"); 1625 } else if (block < le32_to_cpu(ex->ee_block)) { 1626 lblock = block; 1627 len = le32_to_cpu(ex->ee_block) - block; 1628 ext_debug("cache gap(before): %u [%u:%u]", 1629 block, 1630 le32_to_cpu(ex->ee_block), 1631 ext4_ext_get_actual_len(ex)); 1632 } else if (block >= le32_to_cpu(ex->ee_block) 1633 + ext4_ext_get_actual_len(ex)) { 1634 ext4_lblk_t next; 1635 lblock = le32_to_cpu(ex->ee_block) 1636 + ext4_ext_get_actual_len(ex); 1637 1638 next = ext4_ext_next_allocated_block(path); 1639 ext_debug("cache gap(after): [%u:%u] %u", 1640 le32_to_cpu(ex->ee_block), 1641 ext4_ext_get_actual_len(ex), 1642 block); 1643 BUG_ON(next == lblock); 1644 len = next - lblock; 1645 } else { 1646 lblock = len = 0; 1647 BUG(); 1648 } 1649 1650 ext_debug(" -> %u:%lu\n", lblock, len); 1651 ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP); 1652} 1653 1654static int 1655ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, 1656 struct ext4_extent *ex) 1657{ 1658 struct ext4_ext_cache *cex; 1659 1660 cex = &EXT4_I(inode)->i_cached_extent; 1661 1662 /* has cache valid data? */ 1663 if (cex->ec_type == EXT4_EXT_CACHE_NO) 1664 return EXT4_EXT_CACHE_NO; 1665 1666 BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP && 1667 cex->ec_type != EXT4_EXT_CACHE_EXTENT); 1668 if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) { 1669 ex->ee_block = cpu_to_le32(cex->ec_block); 1670 ext4_ext_store_pblock(ex, cex->ec_start); 1671 ex->ee_len = cpu_to_le16(cex->ec_len); 1672 ext_debug("%u cached by %u:%u:%llu\n", 1673 block, 1674 cex->ec_block, cex->ec_len, cex->ec_start); 1675 return cex->ec_type; 1676 } 1677 1678 /* not in cache */ 1679 return EXT4_EXT_CACHE_NO; 1680} 1681 1682/* 1683 * ext4_ext_rm_idx: 1684 * removes index from the index block. 1685 * It's used in truncate case only, thus all requests are for 1686 * last index in the block only. 1687 */ 1688static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, 1689 struct ext4_ext_path *path) 1690{ 1691 struct buffer_head *bh; 1692 int err; 1693 ext4_fsblk_t leaf; 1694 1695 /* free index block */ 1696 path--; 1697 leaf = idx_pblock(path->p_idx); 1698 BUG_ON(path->p_hdr->eh_entries == 0); 1699 err = ext4_ext_get_access(handle, inode, path); 1700 if (err) 1701 return err; 1702 path->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path->p_hdr->eh_entries)-1); 1703 err = ext4_ext_dirty(handle, inode, path); 1704 if (err) 1705 return err; 1706 ext_debug("index is empty, remove it, free block %llu\n", leaf); 1707 bh = sb_find_get_block(inode->i_sb, leaf); 1708 ext4_forget(handle, 1, inode, bh, leaf); 1709 ext4_free_blocks(handle, inode, leaf, 1, 1); 1710 return err; 1711} 1712 1713/* 1714 * ext4_ext_calc_credits_for_insert: 1715 * This routine returns max. credits that the extent tree can consume. 1716 * It should be OK for low-performance paths like ->writepage() 1717 * To allow many writing processes to fit into a single transaction, 1718 * the caller should calculate credits under i_data_sem and 1719 * pass the actual path. 1720 */ 1721int ext4_ext_calc_credits_for_insert(struct inode *inode, 1722 struct ext4_ext_path *path) 1723{ 1724 int depth, needed; 1725 1726 if (path) { 1727 /* probably there is space in leaf? */ 1728 depth = ext_depth(inode); 1729 if (le16_to_cpu(path[depth].p_hdr->eh_entries) 1730 < le16_to_cpu(path[depth].p_hdr->eh_max)) 1731 return 1; 1732 } 1733 1734 /* 1735 * given 32-bit logical block (4294967296 blocks), max. tree 1736 * can be 4 levels in depth -- 4 * 340^4 == 53453440000. 1737 * Let's also add one more level for imbalance. 1738 */ 1739 depth = 5; 1740 1741 /* allocation of new data block(s) */ 1742 needed = 2; 1743 1744 /* 1745 * tree can be full, so it would need to grow in depth: 1746 * we need one credit to modify old root, credits for 1747 * new root will be added in split accounting 1748 */ 1749 needed += 1; 1750 1751 /* 1752 * Index split can happen, we would need: 1753 * allocate intermediate indexes (bitmap + group) 1754 * + change two blocks at each level, but root (already included) 1755 */ 1756 needed += (depth * 2) + (depth * 2); 1757 1758 /* any allocation modifies superblock */ 1759 needed += 1; 1760 1761 return needed; 1762} 1763 1764static int ext4_remove_blocks(handle_t *handle, struct inode *inode, 1765 struct ext4_extent *ex, 1766 ext4_lblk_t from, ext4_lblk_t to) 1767{ 1768 struct buffer_head *bh; 1769 unsigned short ee_len = ext4_ext_get_actual_len(ex); 1770 int i, metadata = 0; 1771 1772 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) 1773 metadata = 1; 1774#ifdef EXTENTS_STATS 1775 { 1776 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 1777 spin_lock(&sbi->s_ext_stats_lock); 1778 sbi->s_ext_blocks += ee_len; 1779 sbi->s_ext_extents++; 1780 if (ee_len < sbi->s_ext_min) 1781 sbi->s_ext_min = ee_len; 1782 if (ee_len > sbi->s_ext_max) 1783 sbi->s_ext_max = ee_len; 1784 if (ext_depth(inode) > sbi->s_depth_max) 1785 sbi->s_depth_max = ext_depth(inode); 1786 spin_unlock(&sbi->s_ext_stats_lock); 1787 } 1788#endif 1789 if (from >= le32_to_cpu(ex->ee_block) 1790 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) { 1791 /* tail removal */ 1792 ext4_lblk_t num; 1793 ext4_fsblk_t start; 1794 1795 num = le32_to_cpu(ex->ee_block) + ee_len - from; 1796 start = ext_pblock(ex) + ee_len - num; 1797 ext_debug("free last %u blocks starting %llu\n", num, start); 1798 for (i = 0; i < num; i++) { 1799 bh = sb_find_get_block(inode->i_sb, start + i); 1800 ext4_forget(handle, 0, inode, bh, start + i); 1801 } 1802 ext4_free_blocks(handle, inode, start, num, metadata); 1803 } else if (from == le32_to_cpu(ex->ee_block) 1804 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) { 1805 printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n", 1806 from, to, le32_to_cpu(ex->ee_block), ee_len); 1807 } else { 1808 printk(KERN_INFO "strange request: removal(2) " 1809 "%u-%u from %u:%u\n", 1810 from, to, le32_to_cpu(ex->ee_block), ee_len); 1811 } 1812 return 0; 1813} 1814 1815static int 1816ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, 1817 struct ext4_ext_path *path, ext4_lblk_t start) 1818{ 1819 int err = 0, correct_index = 0; 1820 int depth = ext_depth(inode), credits; 1821 struct ext4_extent_header *eh; 1822 ext4_lblk_t a, b, block; 1823 unsigned num; 1824 ext4_lblk_t ex_ee_block; 1825 unsigned short ex_ee_len; 1826 unsigned uninitialized = 0; 1827 struct ext4_extent *ex; 1828 1829 /* the header must be checked already in ext4_ext_remove_space() */ 1830 ext_debug("truncate since %u in leaf\n", start); 1831 if (!path[depth].p_hdr) 1832 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); 1833 eh = path[depth].p_hdr; 1834 BUG_ON(eh == NULL); 1835 1836 /* find where to start removing */ 1837 ex = EXT_LAST_EXTENT(eh); 1838 1839 ex_ee_block = le32_to_cpu(ex->ee_block); 1840 if (ext4_ext_is_uninitialized(ex)) 1841 uninitialized = 1; 1842 ex_ee_len = ext4_ext_get_actual_len(ex); 1843 1844 while (ex >= EXT_FIRST_EXTENT(eh) && 1845 ex_ee_block + ex_ee_len > start) { 1846 ext_debug("remove ext %lu:%u\n", ex_ee_block, ex_ee_len); 1847 path[depth].p_ext = ex; 1848 1849 a = ex_ee_block > start ? ex_ee_block : start; 1850 b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ? 1851 ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK; 1852 1853 ext_debug(" border %u:%u\n", a, b); 1854 1855 if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { 1856 block = 0; 1857 num = 0; 1858 BUG(); 1859 } else if (a != ex_ee_block) { 1860 /* remove tail of the extent */ 1861 block = ex_ee_block; 1862 num = a - block; 1863 } else if (b != ex_ee_block + ex_ee_len - 1) { 1864 /* remove head of the extent */ 1865 block = a; 1866 num = b - a; 1867 /* there is no "make a hole" API yet */ 1868 BUG(); 1869 } else { 1870 /* remove whole extent: excellent! */ 1871 block = ex_ee_block; 1872 num = 0; 1873 BUG_ON(a != ex_ee_block); 1874 BUG_ON(b != ex_ee_block + ex_ee_len - 1); 1875 } 1876 1877 /* at present, extent can't cross block group: */ 1878 /* leaf + bitmap + group desc + sb + inode */ 1879 credits = 5; 1880 if (ex == EXT_FIRST_EXTENT(eh)) { 1881 correct_index = 1; 1882 credits += (ext_depth(inode)) + 1; 1883 } 1884#ifdef CONFIG_QUOTA 1885 credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); 1886#endif 1887 1888 handle = ext4_ext_journal_restart(handle, credits); 1889 if (IS_ERR(handle)) { 1890 err = PTR_ERR(handle); 1891 goto out; 1892 } 1893 1894 err = ext4_ext_get_access(handle, inode, path + depth); 1895 if (err) 1896 goto out; 1897 1898 err = ext4_remove_blocks(handle, inode, ex, a, b); 1899 if (err) 1900 goto out; 1901 1902 if (num == 0) { 1903 /* this extent is removed; mark slot entirely unused */ 1904 ext4_ext_store_pblock(ex, 0); 1905 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1); 1906 } 1907 1908 ex->ee_block = cpu_to_le32(block); 1909 ex->ee_len = cpu_to_le16(num); 1910 /* 1911 * Do not mark uninitialized if all the blocks in the 1912 * extent have been removed. 1913 */ 1914 if (uninitialized && num) 1915 ext4_ext_mark_uninitialized(ex); 1916 1917 err = ext4_ext_dirty(handle, inode, path + depth); 1918 if (err) 1919 goto out; 1920 1921 ext_debug("new extent: %u:%u:%llu\n", block, num, 1922 ext_pblock(ex)); 1923 ex--; 1924 ex_ee_block = le32_to_cpu(ex->ee_block); 1925 ex_ee_len = ext4_ext_get_actual_len(ex); 1926 } 1927 1928 if (correct_index && eh->eh_entries) 1929 err = ext4_ext_correct_indexes(handle, inode, path); 1930 1931 /* if this leaf is free, then we should 1932 * remove it from index block above */ 1933 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) 1934 err = ext4_ext_rm_idx(handle, inode, path + depth); 1935 1936out: 1937 return err; 1938} 1939 1940/* 1941 * ext4_ext_more_to_rm: 1942 * returns 1 if current index has to be freed (even partial) 1943 */ 1944static int 1945ext4_ext_more_to_rm(struct ext4_ext_path *path) 1946{ 1947 BUG_ON(path->p_idx == NULL); 1948 1949 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) 1950 return 0; 1951 1952 /* 1953 * if truncate on deeper level happened, it wasn't partial, 1954 * so we have to consider current index for truncation 1955 */ 1956 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) 1957 return 0; 1958 return 1; 1959} 1960 1961static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) 1962{ 1963 struct super_block *sb = inode->i_sb; 1964 int depth = ext_depth(inode); 1965 struct ext4_ext_path *path; 1966 handle_t *handle; 1967 int i = 0, err = 0; 1968 1969 ext_debug("truncate since %u\n", start); 1970 1971 /* probably first extent we're gonna free will be last in block */ 1972 handle = ext4_journal_start(inode, depth + 1); 1973 if (IS_ERR(handle)) 1974 return PTR_ERR(handle); 1975 1976 ext4_ext_invalidate_cache(inode); 1977 1978 /* 1979 * We start scanning from right side, freeing all the blocks 1980 * after i_size and walking into the tree depth-wise. 1981 */ 1982 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL); 1983 if (path == NULL) { 1984 ext4_journal_stop(handle); 1985 return -ENOMEM; 1986 } 1987 path[0].p_hdr = ext_inode_hdr(inode); 1988 if (ext4_ext_check_header(inode, path[0].p_hdr, depth)) { 1989 err = -EIO; 1990 goto out; 1991 } 1992 path[0].p_depth = depth; 1993 1994 while (i >= 0 && err == 0) { 1995 if (i == depth) { 1996 /* this is leaf block */ 1997 err = ext4_ext_rm_leaf(handle, inode, path, start); 1998 /* root level has p_bh == NULL, brelse() eats this */ 1999 brelse(path[i].p_bh); 2000 path[i].p_bh = NULL; 2001 i--; 2002 continue; 2003 } 2004 2005 /* this is index block */ 2006 if (!path[i].p_hdr) { 2007 ext_debug("initialize header\n"); 2008 path[i].p_hdr = ext_block_hdr(path[i].p_bh); 2009 } 2010 2011 if (!path[i].p_idx) { 2012 /* this level hasn't been touched yet */ 2013 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); 2014 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; 2015 ext_debug("init index ptr: hdr 0x%p, num %d\n", 2016 path[i].p_hdr, 2017 le16_to_cpu(path[i].p_hdr->eh_entries)); 2018 } else { 2019 /* we were already here, see at next index */ 2020 path[i].p_idx--; 2021 } 2022 2023 ext_debug("level %d - index, first 0x%p, cur 0x%p\n", 2024 i, EXT_FIRST_INDEX(path[i].p_hdr), 2025 path[i].p_idx); 2026 if (ext4_ext_more_to_rm(path + i)) { 2027 struct buffer_head *bh; 2028 /* go to the next level */ 2029 ext_debug("move to level %d (block %llu)\n", 2030 i + 1, idx_pblock(path[i].p_idx)); 2031 memset(path + i + 1, 0, sizeof(*path)); 2032 bh = sb_bread(sb, idx_pblock(path[i].p_idx)); 2033 if (!bh) { 2034 /* should we reset i_size? */ 2035 err = -EIO; 2036 break; 2037 } 2038 if (WARN_ON(i + 1 > depth)) { 2039 err = -EIO; 2040 break; 2041 } 2042 if (ext4_ext_check_header(inode, ext_block_hdr(bh), 2043 depth - i - 1)) { 2044 err = -EIO; 2045 break; 2046 } 2047 path[i + 1].p_bh = bh; 2048 2049 /* save actual number of indexes since this 2050 * number is changed at the next iteration */ 2051 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); 2052 i++; 2053 } else { 2054 /* we finished processing this index, go up */ 2055 if (path[i].p_hdr->eh_entries == 0 && i > 0) { 2056 /* index is empty, remove it; 2057 * handle must be already prepared by the 2058 * truncatei_leaf() */ 2059 err = ext4_ext_rm_idx(handle, inode, path + i); 2060 } 2061 /* root level has p_bh == NULL, brelse() eats this */ 2062 brelse(path[i].p_bh); 2063 path[i].p_bh = NULL; 2064 i--; 2065 ext_debug("return to level %d\n", i); 2066 } 2067 } 2068 2069 /* TODO: flexible tree reduction should be here */ 2070 if (path->p_hdr->eh_entries == 0) { 2071 /* 2072 * truncate to zero freed all the tree, 2073 * so we need to correct eh_depth 2074 */ 2075 err = ext4_ext_get_access(handle, inode, path); 2076 if (err == 0) { 2077 ext_inode_hdr(inode)->eh_depth = 0; 2078 ext_inode_hdr(inode)->eh_max = 2079 cpu_to_le16(ext4_ext_space_root(inode)); 2080 err = ext4_ext_dirty(handle, inode, path); 2081 } 2082 } 2083out: 2084 ext4_ext_tree_changed(inode); 2085 ext4_ext_drop_refs(path); 2086 kfree(path); 2087 ext4_journal_stop(handle); 2088 2089 return err; 2090} 2091 2092/* 2093 * called at mount time 2094 */ 2095void ext4_ext_init(struct super_block *sb) 2096{ 2097 /* 2098 * possible initialization would be here 2099 */ 2100 2101 if (test_opt(sb, EXTENTS)) { 2102 printk("EXT4-fs: file extents enabled"); 2103#ifdef AGGRESSIVE_TEST 2104 printk(", aggressive tests"); 2105#endif 2106#ifdef CHECK_BINSEARCH 2107 printk(", check binsearch"); 2108#endif 2109#ifdef EXTENTS_STATS 2110 printk(", stats"); 2111#endif 2112 printk("\n"); 2113#ifdef EXTENTS_STATS 2114 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); 2115 EXT4_SB(sb)->s_ext_min = 1 << 30; 2116 EXT4_SB(sb)->s_ext_max = 0; 2117#endif 2118 } 2119} 2120 2121/* 2122 * called at umount time 2123 */ 2124void ext4_ext_release(struct super_block *sb) 2125{ 2126 if (!test_opt(sb, EXTENTS)) 2127 return; 2128 2129#ifdef EXTENTS_STATS 2130 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { 2131 struct ext4_sb_info *sbi = EXT4_SB(sb); 2132 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", 2133 sbi->s_ext_blocks, sbi->s_ext_extents, 2134 sbi->s_ext_blocks / sbi->s_ext_extents); 2135 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", 2136 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); 2137 } 2138#endif 2139} 2140 2141/* 2142 * This function is called by ext4_ext_get_blocks() if someone tries to write 2143 * to an uninitialized extent. It may result in splitting the uninitialized 2144 * extent into multiple extents (upto three - one initialized and two 2145 * uninitialized). 2146 * There are three possibilities: 2147 * a> There is no split required: Entire extent should be initialized 2148 * b> Splits in two extents: Write is happening at either end of the extent 2149 * c> Splits in three extents: Somone is writing in middle of the extent 2150 */ 2151static int ext4_ext_convert_to_initialized(handle_t *handle, 2152 struct inode *inode, 2153 struct ext4_ext_path *path, 2154 ext4_lblk_t iblock, 2155 unsigned long max_blocks) 2156{ 2157 struct ext4_extent *ex, newex; 2158 struct ext4_extent *ex1 = NULL; 2159 struct ext4_extent *ex2 = NULL; 2160 struct ext4_extent *ex3 = NULL; 2161 struct ext4_extent_header *eh; 2162 ext4_lblk_t ee_block; 2163 unsigned int allocated, ee_len, depth; 2164 ext4_fsblk_t newblock; 2165 int err = 0; 2166 int ret = 0; 2167 2168 depth = ext_depth(inode); 2169 eh = path[depth].p_hdr; 2170 ex = path[depth].p_ext; 2171 ee_block = le32_to_cpu(ex->ee_block); 2172 ee_len = ext4_ext_get_actual_len(ex); 2173 allocated = ee_len - (iblock - ee_block); 2174 newblock = iblock - ee_block + ext_pblock(ex); 2175 ex2 = ex; 2176 2177 err = ext4_ext_get_access(handle, inode, path + depth); 2178 if (err) 2179 goto out; 2180 2181 /* ex1: ee_block to iblock - 1 : uninitialized */ 2182 if (iblock > ee_block) { 2183 ex1 = ex; 2184 ex1->ee_len = cpu_to_le16(iblock - ee_block); 2185 ext4_ext_mark_uninitialized(ex1); 2186 ex2 = &newex; 2187 } 2188 /* 2189 * for sanity, update the length of the ex2 extent before 2190 * we insert ex3, if ex1 is NULL. This is to avoid temporary 2191 * overlap of blocks. 2192 */ 2193 if (!ex1 && allocated > max_blocks) 2194 ex2->ee_len = cpu_to_le16(max_blocks); 2195 /* ex3: to ee_block + ee_len : uninitialised */ 2196 if (allocated > max_blocks) { 2197 unsigned int newdepth; 2198 ex3 = &newex; 2199 ex3->ee_block = cpu_to_le32(iblock + max_blocks); 2200 ext4_ext_store_pblock(ex3, newblock + max_blocks); 2201 ex3->ee_len = cpu_to_le16(allocated - max_blocks); 2202 ext4_ext_mark_uninitialized(ex3); 2203 err = ext4_ext_insert_extent(handle, inode, path, ex3); 2204 if (err) 2205 goto out; 2206 /* 2207 * The depth, and hence eh & ex might change 2208 * as part of the insert above. 2209 */ 2210 newdepth = ext_depth(inode); 2211 if (newdepth != depth) { 2212 depth = newdepth; 2213 ext4_ext_drop_refs(path); 2214 path = ext4_ext_find_extent(inode, iblock, path); 2215 if (IS_ERR(path)) { 2216 err = PTR_ERR(path); 2217 goto out; 2218 } 2219 eh = path[depth].p_hdr; 2220 ex = path[depth].p_ext; 2221 if (ex2 != &newex) 2222 ex2 = ex; 2223 2224 err = ext4_ext_get_access(handle, inode, path + depth); 2225 if (err) 2226 goto out; 2227 } 2228 allocated = max_blocks; 2229 } 2230 /* 2231 * If there was a change of depth as part of the 2232 * insertion of ex3 above, we need to update the length 2233 * of the ex1 extent again here 2234 */ 2235 if (ex1 && ex1 != ex) { 2236 ex1 = ex; 2237 ex1->ee_len = cpu_to_le16(iblock - ee_block); 2238 ext4_ext_mark_uninitialized(ex1); 2239 ex2 = &newex; 2240 } 2241 /* ex2: iblock to iblock + maxblocks-1 : initialised */ 2242 ex2->ee_block = cpu_to_le32(iblock); 2243 ext4_ext_store_pblock(ex2, newblock); 2244 ex2->ee_len = cpu_to_le16(allocated); 2245 if (ex2 != ex) 2246 goto insert; 2247 /* 2248 * New (initialized) extent starts from the first block 2249 * in the current extent. i.e., ex2 == ex 2250 * We have to see if it can be merged with the extent 2251 * on the left. 2252 */ 2253 if (ex2 > EXT_FIRST_EXTENT(eh)) { 2254 /* 2255 * To merge left, pass "ex2 - 1" to try_to_merge(), 2256 * since it merges towards right _only_. 2257 */ 2258 ret = ext4_ext_try_to_merge(inode, path, ex2 - 1); 2259 if (ret) { 2260 err = ext4_ext_correct_indexes(handle, inode, path); 2261 if (err) 2262 goto out; 2263 depth = ext_depth(inode); 2264 ex2--; 2265 } 2266 } 2267 /* 2268 * Try to Merge towards right. This might be required 2269 * only when the whole extent is being written to. 2270 * i.e. ex2 == ex and ex3 == NULL. 2271 */ 2272 if (!ex3) { 2273 ret = ext4_ext_try_to_merge(inode, path, ex2); 2274 if (ret) { 2275 err = ext4_ext_correct_indexes(handle, inode, path); 2276 if (err) 2277 goto out; 2278 } 2279 } 2280 /* Mark modified extent as dirty */ 2281 err = ext4_ext_dirty(handle, inode, path + depth); 2282 goto out; 2283insert: 2284 err = ext4_ext_insert_extent(handle, inode, path, &newex); 2285out: 2286 return err ? err : allocated; 2287} 2288 2289/* 2290 * Need to be called with 2291 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block 2292 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) 2293 */ 2294int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, 2295 ext4_lblk_t iblock, 2296 unsigned long max_blocks, struct buffer_head *bh_result, 2297 int create, int extend_disksize) 2298{ 2299 struct ext4_ext_path *path = NULL; 2300 struct ext4_extent_header *eh; 2301 struct ext4_extent newex, *ex; 2302 ext4_fsblk_t goal, newblock; 2303 int err = 0, depth, ret; 2304 unsigned long allocated = 0; 2305 struct ext4_allocation_request ar; 2306 2307 __clear_bit(BH_New, &bh_result->b_state); 2308 ext_debug("blocks %u/%lu requested for inode %u\n", 2309 iblock, max_blocks, inode->i_ino); 2310 2311 /* check in cache */ 2312 goal = ext4_ext_in_cache(inode, iblock, &newex); 2313 if (goal) { 2314 if (goal == EXT4_EXT_CACHE_GAP) { 2315 if (!create) { 2316 /* 2317 * block isn't allocated yet and 2318 * user doesn't want to allocate it 2319 */ 2320 goto out2; 2321 } 2322 /* we should allocate requested block */ 2323 } else if (goal == EXT4_EXT_CACHE_EXTENT) { 2324 /* block is already allocated */ 2325 newblock = iblock 2326 - le32_to_cpu(newex.ee_block) 2327 + ext_pblock(&newex); 2328 /* number of remaining blocks in the extent */ 2329 allocated = ext4_ext_get_actual_len(&newex) - 2330 (iblock - le32_to_cpu(newex.ee_block)); 2331 goto out; 2332 } else { 2333 BUG(); 2334 } 2335 } 2336 2337 /* find extent for this block */ 2338 path = ext4_ext_find_extent(inode, iblock, NULL); 2339 if (IS_ERR(path)) { 2340 err = PTR_ERR(path); 2341 path = NULL; 2342 goto out2; 2343 } 2344 2345 depth = ext_depth(inode); 2346 2347 /* 2348 * consistent leaf must not be empty; 2349 * this situation is possible, though, _during_ tree modification; 2350 * this is why assert can't be put in ext4_ext_find_extent() 2351 */ 2352 BUG_ON(path[depth].p_ext == NULL && depth != 0); 2353 eh = path[depth].p_hdr; 2354 2355 ex = path[depth].p_ext; 2356 if (ex) { 2357 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); 2358 ext4_fsblk_t ee_start = ext_pblock(ex); 2359 unsigned short ee_len; 2360 2361 /* 2362 * Uninitialized extents are treated as holes, except that 2363 * we split out initialized portions during a write. 2364 */ 2365 ee_len = ext4_ext_get_actual_len(ex); 2366 /* if found extent covers block, simply return it */ 2367 if (iblock >= ee_block && iblock < ee_block + ee_len) { 2368 newblock = iblock - ee_block + ee_start; 2369 /* number of remaining blocks in the extent */ 2370 allocated = ee_len - (iblock - ee_block); 2371 ext_debug("%u fit into %lu:%d -> %llu\n", iblock, 2372 ee_block, ee_len, newblock); 2373 2374 /* Do not put uninitialized extent in the cache */ 2375 if (!ext4_ext_is_uninitialized(ex)) { 2376 ext4_ext_put_in_cache(inode, ee_block, 2377 ee_len, ee_start, 2378 EXT4_EXT_CACHE_EXTENT); 2379 goto out; 2380 } 2381 if (create == EXT4_CREATE_UNINITIALIZED_EXT) 2382 goto out; 2383 if (!create) 2384 goto out2; 2385 2386 ret = ext4_ext_convert_to_initialized(handle, inode, 2387 path, iblock, 2388 max_blocks); 2389 if (ret <= 0) { 2390 err = ret; 2391 goto out2; 2392 } else 2393 allocated = ret; 2394 goto outnew; 2395 } 2396 } 2397 2398 /* 2399 * requested block isn't allocated yet; 2400 * we couldn't try to create block if create flag is zero 2401 */ 2402 if (!create) { 2403 /* 2404 * put just found gap into cache to speed up 2405 * subsequent requests 2406 */ 2407 ext4_ext_put_gap_in_cache(inode, path, iblock); 2408 goto out2; 2409 } 2410 /* 2411 * Okay, we need to do block allocation. Lazily initialize the block 2412 * allocation info here if necessary. 2413 */ 2414 if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info)) 2415 ext4_init_block_alloc_info(inode); 2416 2417 /* find neighbour allocated blocks */ 2418 ar.lleft = iblock; 2419 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); 2420 if (err) 2421 goto out2; 2422 ar.lright = iblock; 2423 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright); 2424 if (err) 2425 goto out2; 2426 2427 /* 2428 * See if request is beyond maximum number of blocks we can have in 2429 * a single extent. For an initialized extent this limit is 2430 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is 2431 * EXT_UNINIT_MAX_LEN. 2432 */ 2433 if (max_blocks > EXT_INIT_MAX_LEN && 2434 create != EXT4_CREATE_UNINITIALIZED_EXT) 2435 max_blocks = EXT_INIT_MAX_LEN; 2436 else if (max_blocks > EXT_UNINIT_MAX_LEN && 2437 create == EXT4_CREATE_UNINITIALIZED_EXT) 2438 max_blocks = EXT_UNINIT_MAX_LEN; 2439 2440 /* Check if we can really insert (iblock)::(iblock+max_blocks) extent */ 2441 newex.ee_block = cpu_to_le32(iblock); 2442 newex.ee_len = cpu_to_le16(max_blocks); 2443 err = ext4_ext_check_overlap(inode, &newex, path); 2444 if (err) 2445 allocated = ext4_ext_get_actual_len(&newex); 2446 else 2447 allocated = max_blocks; 2448 2449 /* allocate new block */ 2450 ar.inode = inode; 2451 ar.goal = ext4_ext_find_goal(inode, path, iblock); 2452 ar.logical = iblock; 2453 ar.len = allocated; 2454 if (S_ISREG(inode->i_mode)) 2455 ar.flags = EXT4_MB_HINT_DATA; 2456 else 2457 /* disable in-core preallocation for non-regular files */ 2458 ar.flags = 0; 2459 newblock = ext4_mb_new_blocks(handle, &ar, &err); 2460 if (!newblock) 2461 goto out2; 2462 ext_debug("allocate new block: goal %llu, found %llu/%lu\n", 2463 goal, newblock, allocated); 2464 2465 /* try to insert new extent into found leaf and return */ 2466 ext4_ext_store_pblock(&newex, newblock); 2467 newex.ee_len = cpu_to_le16(ar.len); 2468 if (create == EXT4_CREATE_UNINITIALIZED_EXT) /* Mark uninitialized */ 2469 ext4_ext_mark_uninitialized(&newex); 2470 err = ext4_ext_insert_extent(handle, inode, path, &newex); 2471 if (err) { 2472 /* free data blocks we just allocated */ 2473 /* not a good idea to call discard here directly, 2474 * but otherwise we'd need to call it every free() */ 2475 ext4_mb_discard_inode_preallocations(inode); 2476 ext4_free_blocks(handle, inode, ext_pblock(&newex), 2477 ext4_ext_get_actual_len(&newex), 0); 2478 goto out2; 2479 } 2480 2481 if (extend_disksize && inode->i_size > EXT4_I(inode)->i_disksize) 2482 EXT4_I(inode)->i_disksize = inode->i_size; 2483 2484 /* previous routine could use block we allocated */ 2485 newblock = ext_pblock(&newex); 2486 allocated = ext4_ext_get_actual_len(&newex); 2487outnew: 2488 __set_bit(BH_New, &bh_result->b_state); 2489 2490 /* Cache only when it is _not_ an uninitialized extent */ 2491 if (create != EXT4_CREATE_UNINITIALIZED_EXT) 2492 ext4_ext_put_in_cache(inode, iblock, allocated, newblock, 2493 EXT4_EXT_CACHE_EXTENT); 2494out: 2495 if (allocated > max_blocks) 2496 allocated = max_blocks; 2497 ext4_ext_show_leaf(inode, path); 2498 __set_bit(BH_Mapped, &bh_result->b_state); 2499 bh_result->b_bdev = inode->i_sb->s_bdev; 2500 bh_result->b_blocknr = newblock; 2501out2: 2502 if (path) { 2503 ext4_ext_drop_refs(path); 2504 kfree(path); 2505 } 2506 return err ? err : allocated; 2507} 2508 2509void ext4_ext_truncate(struct inode * inode, struct page *page) 2510{ 2511 struct address_space *mapping = inode->i_mapping; 2512 struct super_block *sb = inode->i_sb; 2513 ext4_lblk_t last_block; 2514 handle_t *handle; 2515 int err = 0; 2516 2517 /* 2518 * probably first extent we're gonna free will be last in block 2519 */ 2520 err = ext4_writepage_trans_blocks(inode) + 3; 2521 handle = ext4_journal_start(inode, err); 2522 if (IS_ERR(handle)) { 2523 if (page) { 2524 clear_highpage(page); 2525 flush_dcache_page(page); 2526 unlock_page(page); 2527 page_cache_release(page); 2528 } 2529 return; 2530 } 2531 2532 if (page) 2533 ext4_block_truncate_page(handle, page, mapping, inode->i_size); 2534 2535 down_write(&EXT4_I(inode)->i_data_sem); 2536 ext4_ext_invalidate_cache(inode); 2537 2538 ext4_mb_discard_inode_preallocations(inode); 2539 2540 /* 2541 * TODO: optimization is possible here. 2542 * Probably we need not scan at all, 2543 * because page truncation is enough. 2544 */ 2545 if (ext4_orphan_add(handle, inode)) 2546 goto out_stop; 2547 2548 /* we have to know where to truncate from in crash case */ 2549 EXT4_I(inode)->i_disksize = inode->i_size; 2550 ext4_mark_inode_dirty(handle, inode); 2551 2552 last_block = (inode->i_size + sb->s_blocksize - 1) 2553 >> EXT4_BLOCK_SIZE_BITS(sb); 2554 err = ext4_ext_remove_space(inode, last_block); 2555 2556 /* In a multi-transaction truncate, we only make the final 2557 * transaction synchronous. 2558 */ 2559 if (IS_SYNC(inode)) 2560 handle->h_sync = 1; 2561 2562out_stop: 2563 /* 2564 * If this was a simple ftruncate() and the file will remain alive, 2565 * then we need to clear up the orphan record which we created above. 2566 * However, if this was a real unlink then we were called by 2567 * ext4_delete_inode(), and we allow that function to clean up the 2568 * orphan info for us. 2569 */ 2570 if (inode->i_nlink) 2571 ext4_orphan_del(handle, inode); 2572 2573 up_write(&EXT4_I(inode)->i_data_sem); 2574 ext4_journal_stop(handle); 2575} 2576 2577/* 2578 * ext4_ext_writepage_trans_blocks: 2579 * calculate max number of blocks we could modify 2580 * in order to allocate new block for an inode 2581 */ 2582int ext4_ext_writepage_trans_blocks(struct inode *inode, int num) 2583{ 2584 int needed; 2585 2586 needed = ext4_ext_calc_credits_for_insert(inode, NULL); 2587 2588 /* caller wants to allocate num blocks, but note it includes sb */ 2589 needed = needed * num - (num - 1); 2590 2591#ifdef CONFIG_QUOTA 2592 needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); 2593#endif 2594 2595 return needed; 2596} 2597 2598/* 2599 * preallocate space for a file. This implements ext4's fallocate inode 2600 * operation, which gets called from sys_fallocate system call. 2601 * For block-mapped files, posix_fallocate should fall back to the method 2602 * of writing zeroes to the required new blocks (the same behavior which is 2603 * expected for file systems which do not support fallocate() system call). 2604 */ 2605long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len) 2606{ 2607 handle_t *handle; 2608 ext4_lblk_t block; 2609 unsigned long max_blocks; 2610 ext4_fsblk_t nblocks = 0; 2611 int ret = 0; 2612 int ret2 = 0; 2613 int retries = 0; 2614 struct buffer_head map_bh; 2615 unsigned int credits, blkbits = inode->i_blkbits; 2616 2617 /* 2618 * currently supporting (pre)allocate mode for extent-based 2619 * files _only_ 2620 */ 2621 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) 2622 return -EOPNOTSUPP; 2623 2624 /* preallocation to directories is currently not supported */ 2625 if (S_ISDIR(inode->i_mode)) 2626 return -ENODEV; 2627 2628 block = offset >> blkbits; 2629 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) 2630 - block; 2631 2632 /* 2633 * credits to insert 1 extent into extent tree + buffers to be able to 2634 * modify 1 super block, 1 block bitmap and 1 group descriptor. 2635 */ 2636 credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3; 2637 mutex_lock(&inode->i_mutex); 2638retry: 2639 while (ret >= 0 && ret < max_blocks) { 2640 block = block + ret; 2641 max_blocks = max_blocks - ret; 2642 handle = ext4_journal_start(inode, credits); 2643 if (IS_ERR(handle)) { 2644 ret = PTR_ERR(handle); 2645 break; 2646 } 2647 2648 ret = ext4_get_blocks_wrap(handle, inode, block, 2649 max_blocks, &map_bh, 2650 EXT4_CREATE_UNINITIALIZED_EXT, 0); 2651 WARN_ON(ret <= 0); 2652 if (ret <= 0) { 2653 ext4_error(inode->i_sb, "ext4_fallocate", 2654 "ext4_ext_get_blocks returned error: " 2655 "inode#%lu, block=%u, max_blocks=%lu", 2656 inode->i_ino, block, max_blocks); 2657 ret = -EIO; 2658 ext4_mark_inode_dirty(handle, inode); 2659 ret2 = ext4_journal_stop(handle); 2660 break; 2661 } 2662 if (ret > 0) { 2663 /* check wrap through sign-bit/zero here */ 2664 if ((block + ret) < 0 || (block + ret) < block) { 2665 ret = -EIO; 2666 ext4_mark_inode_dirty(handle, inode); 2667 ret2 = ext4_journal_stop(handle); 2668 break; 2669 } 2670 if (buffer_new(&map_bh) && ((block + ret) > 2671 (EXT4_BLOCK_ALIGN(i_size_read(inode), blkbits) 2672 >> blkbits))) 2673 nblocks = nblocks + ret; 2674 } 2675 2676 /* Update ctime if new blocks get allocated */ 2677 if (nblocks) { 2678 struct timespec now; 2679 2680 now = current_fs_time(inode->i_sb); 2681 if (!timespec_equal(&inode->i_ctime, &now)) 2682 inode->i_ctime = now; 2683 } 2684 2685 ext4_mark_inode_dirty(handle, inode); 2686 ret2 = ext4_journal_stop(handle); 2687 if (ret2) 2688 break; 2689 } 2690 2691 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) 2692 goto retry; 2693 2694 /* 2695 * Time to update the file size. 2696 * Update only when preallocation was requested beyond the file size. 2697 */ 2698 if (!(mode & FALLOC_FL_KEEP_SIZE) && 2699 (offset + len) > i_size_read(inode)) { 2700 if (ret > 0) { 2701 /* 2702 * if no error, we assume preallocation succeeded 2703 * completely 2704 */ 2705 i_size_write(inode, offset + len); 2706 EXT4_I(inode)->i_disksize = i_size_read(inode); 2707 } else if (ret < 0 && nblocks) { 2708 /* Handle partial allocation scenario */ 2709 loff_t newsize; 2710 2711 newsize = (nblocks << blkbits) + i_size_read(inode); 2712 i_size_write(inode, EXT4_BLOCK_ALIGN(newsize, blkbits)); 2713 EXT4_I(inode)->i_disksize = i_size_read(inode); 2714 } 2715 } 2716 2717 mutex_unlock(&inode->i_mutex); 2718 return ret > 0 ? ret2 : ret; 2719} 2720