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 */ 51 static 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 */ 64 ext4_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 */ 78 void 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 */ 89 static 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 95 static 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 */ 113 static 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 */ 131 static 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 } 144 145 static 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_grpblk_t colour; 152 int depth; 153 154 if (path) { 155 struct ext4_extent *ex; 156 depth = path->p_depth; 157 158 /* try to predict block placement */ 159 ex = path[depth].p_ext; 160 if (ex) 161 return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block)); 162 163 /* it looks like index is empty; 164 * try to find starting block from index itself */ 165 if (path[depth].p_bh) 166 return path[depth].p_bh->b_blocknr; 167 } 168 169 /* OK. use inode's group */ 170 bg_start = (ei->i_block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) + 171 le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block); 172 colour = (current->pid % 16) * 173 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); 174 return bg_start + colour + block; 175 } 176 177 static ext4_fsblk_t 178 ext4_ext_new_block(handle_t *handle, struct inode *inode, 179 struct ext4_ext_path *path, 180 struct ext4_extent *ex, int *err) 181 { 182 ext4_fsblk_t goal, newblock; 183 184 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); 185 newblock = ext4_new_block(handle, inode, goal, err); 186 return newblock; 187 } 188 189 static int ext4_ext_space_block(struct inode *inode) 190 { 191 int size; 192 193 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 194 / sizeof(struct ext4_extent); 195 #ifdef AGGRESSIVE_TEST 196 if (size > 6) 197 size = 6; 198 #endif 199 return size; 200 } 201 202 static int ext4_ext_space_block_idx(struct inode *inode) 203 { 204 int size; 205 206 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 207 / sizeof(struct ext4_extent_idx); 208 #ifdef AGGRESSIVE_TEST 209 if (size > 5) 210 size = 5; 211 #endif 212 return size; 213 } 214 215 static int ext4_ext_space_root(struct inode *inode) 216 { 217 int size; 218 219 size = sizeof(EXT4_I(inode)->i_data); 220 size -= sizeof(struct ext4_extent_header); 221 size /= sizeof(struct ext4_extent); 222 #ifdef AGGRESSIVE_TEST 223 if (size > 3) 224 size = 3; 225 #endif 226 return size; 227 } 228 229 static int ext4_ext_space_root_idx(struct inode *inode) 230 { 231 int size; 232 233 size = sizeof(EXT4_I(inode)->i_data); 234 size -= sizeof(struct ext4_extent_header); 235 size /= sizeof(struct ext4_extent_idx); 236 #ifdef AGGRESSIVE_TEST 237 if (size > 4) 238 size = 4; 239 #endif 240 return size; 241 } 242 243 static int 244 ext4_ext_max_entries(struct inode *inode, int depth) 245 { 246 int max; 247 248 if (depth == ext_depth(inode)) { 249 if (depth == 0) 250 max = ext4_ext_space_root(inode); 251 else 252 max = ext4_ext_space_root_idx(inode); 253 } else { 254 if (depth == 0) 255 max = ext4_ext_space_block(inode); 256 else 257 max = ext4_ext_space_block_idx(inode); 258 } 259 260 return max; 261 } 262 263 static int __ext4_ext_check_header(const char *function, struct inode *inode, 264 struct ext4_extent_header *eh, 265 int depth) 266 { 267 const char *error_msg; 268 int max = 0; 269 270 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { 271 error_msg = "invalid magic"; 272 goto corrupted; 273 } 274 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { 275 error_msg = "unexpected eh_depth"; 276 goto corrupted; 277 } 278 if (unlikely(eh->eh_max == 0)) { 279 error_msg = "invalid eh_max"; 280 goto corrupted; 281 } 282 max = ext4_ext_max_entries(inode, depth); 283 if (unlikely(le16_to_cpu(eh->eh_max) > max)) { 284 error_msg = "too large eh_max"; 285 goto corrupted; 286 } 287 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { 288 error_msg = "invalid eh_entries"; 289 goto corrupted; 290 } 291 return 0; 292 293 corrupted: 294 ext4_error(inode->i_sb, function, 295 "bad header in inode #%lu: %s - magic %x, " 296 "entries %u, max %u(%u), depth %u(%u)", 297 inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic), 298 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), 299 max, le16_to_cpu(eh->eh_depth), depth); 300 301 return -EIO; 302 } 303 304 #define ext4_ext_check_header(inode, eh, depth) \ 305 __ext4_ext_check_header(__FUNCTION__, inode, eh, depth) 306 307 #ifdef EXT_DEBUG 308 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) 309 { 310 int k, l = path->p_depth; 311 312 ext_debug("path:"); 313 for (k = 0; k <= l; k++, path++) { 314 if (path->p_idx) { 315 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), 316 idx_pblock(path->p_idx)); 317 } else if (path->p_ext) { 318 ext_debug(" %d:%d:%llu ", 319 le32_to_cpu(path->p_ext->ee_block), 320 ext4_ext_get_actual_len(path->p_ext), 321 ext_pblock(path->p_ext)); 322 } else 323 ext_debug(" []"); 324 } 325 ext_debug("\n"); 326 } 327 328 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) 329 { 330 int depth = ext_depth(inode); 331 struct ext4_extent_header *eh; 332 struct ext4_extent *ex; 333 int i; 334 335 if (!path) 336 return; 337 338 eh = path[depth].p_hdr; 339 ex = EXT_FIRST_EXTENT(eh); 340 341 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { 342 ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block), 343 ext4_ext_get_actual_len(ex), ext_pblock(ex)); 344 } 345 ext_debug("\n"); 346 } 347 #else 348 #define ext4_ext_show_path(inode,path) 349 #define ext4_ext_show_leaf(inode,path) 350 #endif 351 352 static void ext4_ext_drop_refs(struct ext4_ext_path *path) 353 { 354 int depth = path->p_depth; 355 int i; 356 357 for (i = 0; i <= depth; i++, path++) 358 if (path->p_bh) { 359 brelse(path->p_bh); 360 path->p_bh = NULL; 361 } 362 } 363 364 /* 365 * ext4_ext_binsearch_idx: 366 * binary search for the closest index of the given block 367 * the header must be checked before calling this 368 */ 369 static void 370 ext4_ext_binsearch_idx(struct inode *inode, 371 struct ext4_ext_path *path, ext4_lblk_t block) 372 { 373 struct ext4_extent_header *eh = path->p_hdr; 374 struct ext4_extent_idx *r, *l, *m; 375 376 377 ext_debug("binsearch for %u(idx): ", block); 378 379 l = EXT_FIRST_INDEX(eh) + 1; 380 r = EXT_LAST_INDEX(eh); 381 while (l <= r) { 382 m = l + (r - l) / 2; 383 if (block < le32_to_cpu(m->ei_block)) 384 r = m - 1; 385 else 386 l = m + 1; 387 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), 388 m, le32_to_cpu(m->ei_block), 389 r, le32_to_cpu(r->ei_block)); 390 } 391 392 path->p_idx = l - 1; 393 ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block), 394 idx_pblock(path->p_idx)); 395 396 #ifdef CHECK_BINSEARCH 397 { 398 struct ext4_extent_idx *chix, *ix; 399 int k; 400 401 chix = ix = EXT_FIRST_INDEX(eh); 402 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { 403 if (k != 0 && 404 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { 405 printk("k=%d, ix=0x%p, first=0x%p\n", k, 406 ix, EXT_FIRST_INDEX(eh)); 407 printk("%u <= %u\n", 408 le32_to_cpu(ix->ei_block), 409 le32_to_cpu(ix[-1].ei_block)); 410 } 411 BUG_ON(k && le32_to_cpu(ix->ei_block) 412 <= le32_to_cpu(ix[-1].ei_block)); 413 if (block < le32_to_cpu(ix->ei_block)) 414 break; 415 chix = ix; 416 } 417 BUG_ON(chix != path->p_idx); 418 } 419 #endif 420 421 } 422 423 /* 424 * ext4_ext_binsearch: 425 * binary search for closest extent of the given block 426 * the header must be checked before calling this 427 */ 428 static void 429 ext4_ext_binsearch(struct inode *inode, 430 struct ext4_ext_path *path, ext4_lblk_t block) 431 { 432 struct ext4_extent_header *eh = path->p_hdr; 433 struct ext4_extent *r, *l, *m; 434 435 if (eh->eh_entries == 0) { 436 /* 437 * this leaf is empty: 438 * we get such a leaf in split/add case 439 */ 440 return; 441 } 442 443 ext_debug("binsearch for %u: ", block); 444 445 l = EXT_FIRST_EXTENT(eh) + 1; 446 r = EXT_LAST_EXTENT(eh); 447 448 while (l <= r) { 449 m = l + (r - l) / 2; 450 if (block < le32_to_cpu(m->ee_block)) 451 r = m - 1; 452 else 453 l = m + 1; 454 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), 455 m, le32_to_cpu(m->ee_block), 456 r, le32_to_cpu(r->ee_block)); 457 } 458 459 path->p_ext = l - 1; 460 ext_debug(" -> %d:%llu:%d ", 461 le32_to_cpu(path->p_ext->ee_block), 462 ext_pblock(path->p_ext), 463 ext4_ext_get_actual_len(path->p_ext)); 464 465 #ifdef CHECK_BINSEARCH 466 { 467 struct ext4_extent *chex, *ex; 468 int k; 469 470 chex = ex = EXT_FIRST_EXTENT(eh); 471 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { 472 BUG_ON(k && le32_to_cpu(ex->ee_block) 473 <= le32_to_cpu(ex[-1].ee_block)); 474 if (block < le32_to_cpu(ex->ee_block)) 475 break; 476 chex = ex; 477 } 478 BUG_ON(chex != path->p_ext); 479 } 480 #endif 481 482 } 483 484 int ext4_ext_tree_init(handle_t *handle, struct inode *inode) 485 { 486 struct ext4_extent_header *eh; 487 488 eh = ext_inode_hdr(inode); 489 eh->eh_depth = 0; 490 eh->eh_entries = 0; 491 eh->eh_magic = EXT4_EXT_MAGIC; 492 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode)); 493 ext4_mark_inode_dirty(handle, inode); 494 ext4_ext_invalidate_cache(inode); 495 return 0; 496 } 497 498 struct ext4_ext_path * 499 ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, 500 struct ext4_ext_path *path) 501 { 502 struct ext4_extent_header *eh; 503 struct buffer_head *bh; 504 short int depth, i, ppos = 0, alloc = 0; 505 506 eh = ext_inode_hdr(inode); 507 depth = ext_depth(inode); 508 if (ext4_ext_check_header(inode, eh, depth)) 509 return ERR_PTR(-EIO); 510 511 512 /* account possible depth increase */ 513 if (!path) { 514 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2), 515 GFP_NOFS); 516 if (!path) 517 return ERR_PTR(-ENOMEM); 518 alloc = 1; 519 } 520 path[0].p_hdr = eh; 521 522 i = depth; 523 /* walk through the tree */ 524 while (i) { 525 ext_debug("depth %d: num %d, max %d\n", 526 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); 527 528 ext4_ext_binsearch_idx(inode, path + ppos, block); 529 path[ppos].p_block = idx_pblock(path[ppos].p_idx); 530 path[ppos].p_depth = i; 531 path[ppos].p_ext = NULL; 532 533 bh = sb_bread(inode->i_sb, path[ppos].p_block); 534 if (!bh) 535 goto err; 536 537 eh = ext_block_hdr(bh); 538 ppos++; 539 BUG_ON(ppos > depth); 540 path[ppos].p_bh = bh; 541 path[ppos].p_hdr = eh; 542 i--; 543 544 if (ext4_ext_check_header(inode, eh, i)) 545 goto err; 546 } 547 548 path[ppos].p_depth = i; 549 path[ppos].p_hdr = eh; 550 path[ppos].p_ext = NULL; 551 path[ppos].p_idx = NULL; 552 553 /* find extent */ 554 ext4_ext_binsearch(inode, path + ppos, block); 555 556 ext4_ext_show_path(inode, path); 557 558 return path; 559 560 err: 561 ext4_ext_drop_refs(path); 562 if (alloc) 563 kfree(path); 564 return ERR_PTR(-EIO); 565 } 566 567 /* 568 * ext4_ext_insert_index: 569 * insert new index [@logical;@ptr] into the block at @curp; 570 * check where to insert: before @curp or after @curp 571 */ 572 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, 573 struct ext4_ext_path *curp, 574 int logical, ext4_fsblk_t ptr) 575 { 576 struct ext4_extent_idx *ix; 577 int len, err; 578 579 err = ext4_ext_get_access(handle, inode, curp); 580 if (err) 581 return err; 582 583 BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block)); 584 len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx; 585 if (logical > le32_to_cpu(curp->p_idx->ei_block)) { 586 /* insert after */ 587 if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) { 588 len = (len - 1) * sizeof(struct ext4_extent_idx); 589 len = len < 0 ? 0 : len; 590 ext_debug("insert new index %d after: %llu. " 591 "move %d from 0x%p to 0x%p\n", 592 logical, ptr, len, 593 (curp->p_idx + 1), (curp->p_idx + 2)); 594 memmove(curp->p_idx + 2, curp->p_idx + 1, len); 595 } 596 ix = curp->p_idx + 1; 597 } else { 598 /* insert before */ 599 len = len * sizeof(struct ext4_extent_idx); 600 len = len < 0 ? 0 : len; 601 ext_debug("insert new index %d before: %llu. " 602 "move %d from 0x%p to 0x%p\n", 603 logical, ptr, len, 604 curp->p_idx, (curp->p_idx + 1)); 605 memmove(curp->p_idx + 1, curp->p_idx, len); 606 ix = curp->p_idx; 607 } 608 609 ix->ei_block = cpu_to_le32(logical); 610 ext4_idx_store_pblock(ix, ptr); 611 curp->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(curp->p_hdr->eh_entries)+1); 612 613 BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries) 614 > le16_to_cpu(curp->p_hdr->eh_max)); 615 BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr)); 616 617 err = ext4_ext_dirty(handle, inode, curp); 618 ext4_std_error(inode->i_sb, err); 619 620 return err; 621 } 622 623 /* 624 * ext4_ext_split: 625 * inserts new subtree into the path, using free index entry 626 * at depth @at: 627 * - allocates all needed blocks (new leaf and all intermediate index blocks) 628 * - makes decision where to split 629 * - moves remaining extents and index entries (right to the split point) 630 * into the newly allocated blocks 631 * - initializes subtree 632 */ 633 static int ext4_ext_split(handle_t *handle, struct inode *inode, 634 struct ext4_ext_path *path, 635 struct ext4_extent *newext, int at) 636 { 637 struct buffer_head *bh = NULL; 638 int depth = ext_depth(inode); 639 struct ext4_extent_header *neh; 640 struct ext4_extent_idx *fidx; 641 struct ext4_extent *ex; 642 int i = at, k, m, a; 643 ext4_fsblk_t newblock, oldblock; 644 __le32 border; 645 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ 646 int err = 0; 647 648 /* make decision: where to split? */ 649 /* FIXME: now decision is simplest: at current extent */ 650 651 /* if current leaf will be split, then we should use 652 * border from split point */ 653 BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr)); 654 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { 655 border = path[depth].p_ext[1].ee_block; 656 ext_debug("leaf will be split." 657 " next leaf starts at %d\n", 658 le32_to_cpu(border)); 659 } else { 660 border = newext->ee_block; 661 ext_debug("leaf will be added." 662 " next leaf starts at %d\n", 663 le32_to_cpu(border)); 664 } 665 666 /* 667 * If error occurs, then we break processing 668 * and mark filesystem read-only. index won't 669 * be inserted and tree will be in consistent 670 * state. Next mount will repair buffers too. 671 */ 672 673 /* 674 * Get array to track all allocated blocks. 675 * We need this to handle errors and free blocks 676 * upon them. 677 */ 678 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); 679 if (!ablocks) 680 return -ENOMEM; 681 682 /* allocate all needed blocks */ 683 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); 684 for (a = 0; a < depth - at; a++) { 685 newblock = ext4_ext_new_block(handle, inode, path, newext, &err); 686 if (newblock == 0) 687 goto cleanup; 688 ablocks[a] = newblock; 689 } 690 691 /* initialize new leaf */ 692 newblock = ablocks[--a]; 693 BUG_ON(newblock == 0); 694 bh = sb_getblk(inode->i_sb, newblock); 695 if (!bh) { 696 err = -EIO; 697 goto cleanup; 698 } 699 lock_buffer(bh); 700 701 err = ext4_journal_get_create_access(handle, bh); 702 if (err) 703 goto cleanup; 704 705 neh = ext_block_hdr(bh); 706 neh->eh_entries = 0; 707 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); 708 neh->eh_magic = EXT4_EXT_MAGIC; 709 neh->eh_depth = 0; 710 ex = EXT_FIRST_EXTENT(neh); 711 712 /* move remainder of path[depth] to the new leaf */ 713 BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max); 714 /* start copy from next extent */ 715 /* TODO: we could do it by single memmove */ 716 m = 0; 717 path[depth].p_ext++; 718 while (path[depth].p_ext <= 719 EXT_MAX_EXTENT(path[depth].p_hdr)) { 720 ext_debug("move %d:%llu:%d in new leaf %llu\n", 721 le32_to_cpu(path[depth].p_ext->ee_block), 722 ext_pblock(path[depth].p_ext), 723 ext4_ext_get_actual_len(path[depth].p_ext), 724 newblock); 725 /*memmove(ex++, path[depth].p_ext++, 726 sizeof(struct ext4_extent)); 727 neh->eh_entries++;*/ 728 path[depth].p_ext++; 729 m++; 730 } 731 if (m) { 732 memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m); 733 neh->eh_entries = cpu_to_le16(le16_to_cpu(neh->eh_entries)+m); 734 } 735 736 set_buffer_uptodate(bh); 737 unlock_buffer(bh); 738 739 err = ext4_journal_dirty_metadata(handle, bh); 740 if (err) 741 goto cleanup; 742 brelse(bh); 743 bh = NULL; 744 745 /* correct old leaf */ 746 if (m) { 747 err = ext4_ext_get_access(handle, inode, path + depth); 748 if (err) 749 goto cleanup; 750 path[depth].p_hdr->eh_entries = 751 cpu_to_le16(le16_to_cpu(path[depth].p_hdr->eh_entries)-m); 752 err = ext4_ext_dirty(handle, inode, path + depth); 753 if (err) 754 goto cleanup; 755 756 } 757 758 /* create intermediate indexes */ 759 k = depth - at - 1; 760 BUG_ON(k < 0); 761 if (k) 762 ext_debug("create %d intermediate indices\n", k); 763 /* insert new index into current index block */ 764 /* current depth stored in i var */ 765 i = depth - 1; 766 while (k--) { 767 oldblock = newblock; 768 newblock = ablocks[--a]; 769 bh = sb_getblk(inode->i_sb, newblock); 770 if (!bh) { 771 err = -EIO; 772 goto cleanup; 773 } 774 lock_buffer(bh); 775 776 err = ext4_journal_get_create_access(handle, bh); 777 if (err) 778 goto cleanup; 779 780 neh = ext_block_hdr(bh); 781 neh->eh_entries = cpu_to_le16(1); 782 neh->eh_magic = EXT4_EXT_MAGIC; 783 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); 784 neh->eh_depth = cpu_to_le16(depth - i); 785 fidx = EXT_FIRST_INDEX(neh); 786 fidx->ei_block = border; 787 ext4_idx_store_pblock(fidx, oldblock); 788 789 ext_debug("int.index at %d (block %llu): %u -> %llu\n", 790 i, newblock, le32_to_cpu(border), oldblock); 791 /* copy indexes */ 792 m = 0; 793 path[i].p_idx++; 794 795 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, 796 EXT_MAX_INDEX(path[i].p_hdr)); 797 BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) != 798 EXT_LAST_INDEX(path[i].p_hdr)); 799 while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) { 800 ext_debug("%d: move %d:%llu in new index %llu\n", i, 801 le32_to_cpu(path[i].p_idx->ei_block), 802 idx_pblock(path[i].p_idx), 803 newblock); 804 /*memmove(++fidx, path[i].p_idx++, 805 sizeof(struct ext4_extent_idx)); 806 neh->eh_entries++; 807 BUG_ON(neh->eh_entries > neh->eh_max);*/ 808 path[i].p_idx++; 809 m++; 810 } 811 if (m) { 812 memmove(++fidx, path[i].p_idx - m, 813 sizeof(struct ext4_extent_idx) * m); 814 neh->eh_entries = 815 cpu_to_le16(le16_to_cpu(neh->eh_entries) + m); 816 } 817 set_buffer_uptodate(bh); 818 unlock_buffer(bh); 819 820 err = ext4_journal_dirty_metadata(handle, bh); 821 if (err) 822 goto cleanup; 823 brelse(bh); 824 bh = NULL; 825 826 /* correct old index */ 827 if (m) { 828 err = ext4_ext_get_access(handle, inode, path + i); 829 if (err) 830 goto cleanup; 831 path[i].p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path[i].p_hdr->eh_entries)-m); 832 err = ext4_ext_dirty(handle, inode, path + i); 833 if (err) 834 goto cleanup; 835 } 836 837 i--; 838 } 839 840 /* insert new index */ 841 err = ext4_ext_insert_index(handle, inode, path + at, 842 le32_to_cpu(border), newblock); 843 844 cleanup: 845 if (bh) { 846 if (buffer_locked(bh)) 847 unlock_buffer(bh); 848 brelse(bh); 849 } 850 851 if (err) { 852 /* free all allocated blocks in error case */ 853 for (i = 0; i < depth; i++) { 854 if (!ablocks[i]) 855 continue; 856 ext4_free_blocks(handle, inode, ablocks[i], 1, 1); 857 } 858 } 859 kfree(ablocks); 860 861 return err; 862 } 863 864 /* 865 * ext4_ext_grow_indepth: 866 * implements tree growing procedure: 867 * - allocates new block 868 * - moves top-level data (index block or leaf) into the new block 869 * - initializes new top-level, creating index that points to the 870 * just created block 871 */ 872 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, 873 struct ext4_ext_path *path, 874 struct ext4_extent *newext) 875 { 876 struct ext4_ext_path *curp = path; 877 struct ext4_extent_header *neh; 878 struct ext4_extent_idx *fidx; 879 struct buffer_head *bh; 880 ext4_fsblk_t newblock; 881 int err = 0; 882 883 newblock = ext4_ext_new_block(handle, inode, path, newext, &err); 884 if (newblock == 0) 885 return err; 886 887 bh = sb_getblk(inode->i_sb, newblock); 888 if (!bh) { 889 err = -EIO; 890 ext4_std_error(inode->i_sb, err); 891 return err; 892 } 893 lock_buffer(bh); 894 895 err = ext4_journal_get_create_access(handle, bh); 896 if (err) { 897 unlock_buffer(bh); 898 goto out; 899 } 900 901 /* move top-level index/leaf into new block */ 902 memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data)); 903 904 /* set size of new block */ 905 neh = ext_block_hdr(bh); 906 /* old root could have indexes or leaves 907 * so calculate e_max right way */ 908 if (ext_depth(inode)) 909 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); 910 else 911 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); 912 neh->eh_magic = EXT4_EXT_MAGIC; 913 set_buffer_uptodate(bh); 914 unlock_buffer(bh); 915 916 err = ext4_journal_dirty_metadata(handle, bh); 917 if (err) 918 goto out; 919 920 /* create index in new top-level index: num,max,pointer */ 921 err = ext4_ext_get_access(handle, inode, curp); 922 if (err) 923 goto out; 924 925 curp->p_hdr->eh_magic = EXT4_EXT_MAGIC; 926 curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode)); 927 curp->p_hdr->eh_entries = cpu_to_le16(1); 928 curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr); 929 930 if (path[0].p_hdr->eh_depth) 931 curp->p_idx->ei_block = 932 EXT_FIRST_INDEX(path[0].p_hdr)->ei_block; 933 else 934 curp->p_idx->ei_block = 935 EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block; 936 ext4_idx_store_pblock(curp->p_idx, newblock); 937 938 neh = ext_inode_hdr(inode); 939 fidx = EXT_FIRST_INDEX(neh); 940 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", 941 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), 942 le32_to_cpu(fidx->ei_block), idx_pblock(fidx)); 943 944 neh->eh_depth = cpu_to_le16(path->p_depth + 1); 945 err = ext4_ext_dirty(handle, inode, curp); 946 out: 947 brelse(bh); 948 949 return err; 950 } 951 952 /* 953 * ext4_ext_create_new_leaf: 954 * finds empty index and adds new leaf. 955 * if no free index is found, then it requests in-depth growing. 956 */ 957 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, 958 struct ext4_ext_path *path, 959 struct ext4_extent *newext) 960 { 961 struct ext4_ext_path *curp; 962 int depth, i, err = 0; 963 964 repeat: 965 i = depth = ext_depth(inode); 966 967 /* walk up to the tree and look for free index entry */ 968 curp = path + depth; 969 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { 970 i--; 971 curp--; 972 } 973 974 /* we use already allocated block for index block, 975 * so subsequent data blocks should be contiguous */ 976 if (EXT_HAS_FREE_INDEX(curp)) { 977 /* if we found index with free entry, then use that 978 * entry: create all needed subtree and add new leaf */ 979 err = ext4_ext_split(handle, inode, path, newext, i); 980 981 /* refill path */ 982 ext4_ext_drop_refs(path); 983 path = ext4_ext_find_extent(inode, 984 (ext4_lblk_t)le32_to_cpu(newext->ee_block), 985 path); 986 if (IS_ERR(path)) 987 err = PTR_ERR(path); 988 } else { 989 /* tree is full, time to grow in depth */ 990 err = ext4_ext_grow_indepth(handle, inode, path, newext); 991 if (err) 992 goto out; 993 994 /* refill path */ 995 ext4_ext_drop_refs(path); 996 path = ext4_ext_find_extent(inode, 997 (ext4_lblk_t)le32_to_cpu(newext->ee_block), 998 path); 999 if (IS_ERR(path)) { 1000 err = PTR_ERR(path); 1001 goto out; 1002 } 1003 1004 /* 1005 * only first (depth 0 -> 1) produces free space; 1006 * in all other cases we have to split the grown tree 1007 */ 1008 depth = ext_depth(inode); 1009 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { 1010 /* now we need to split */ 1011 goto repeat; 1012 } 1013 } 1014 1015 out: 1016 return err; 1017 } 1018 1019 /* 1020 * search the closest allocated block to the left for *logical 1021 * and returns it at @logical + it's physical address at @phys 1022 * if *logical is the smallest allocated block, the function 1023 * returns 0 at @phys 1024 * return value contains 0 (success) or error code 1025 */ 1026 int 1027 ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path, 1028 ext4_lblk_t *logical, ext4_fsblk_t *phys) 1029 { 1030 struct ext4_extent_idx *ix; 1031 struct ext4_extent *ex; 1032 int depth, ee_len; 1033 1034 BUG_ON(path == NULL); 1035 depth = path->p_depth; 1036 *phys = 0; 1037 1038 if (depth == 0 && path->p_ext == NULL) 1039 return 0; 1040 1041 /* usually extent in the path covers blocks smaller 1042 * then *logical, but it can be that extent is the 1043 * first one in the file */ 1044 1045 ex = path[depth].p_ext; 1046 ee_len = ext4_ext_get_actual_len(ex); 1047 if (*logical < le32_to_cpu(ex->ee_block)) { 1048 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex); 1049 while (--depth >= 0) { 1050 ix = path[depth].p_idx; 1051 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr)); 1052 } 1053 return 0; 1054 } 1055 1056 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len)); 1057 1058 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; 1059 *phys = ext_pblock(ex) + ee_len - 1; 1060 return 0; 1061 } 1062 1063 /* 1064 * search the closest allocated block to the right for *logical 1065 * and returns it at @logical + it's physical address at @phys 1066 * if *logical is the smallest allocated block, the function 1067 * returns 0 at @phys 1068 * return value contains 0 (success) or error code 1069 */ 1070 int 1071 ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, 1072 ext4_lblk_t *logical, ext4_fsblk_t *phys) 1073 { 1074 struct buffer_head *bh = NULL; 1075 struct ext4_extent_header *eh; 1076 struct ext4_extent_idx *ix; 1077 struct ext4_extent *ex; 1078 ext4_fsblk_t block; 1079 int depth, ee_len; 1080 1081 BUG_ON(path == NULL); 1082 depth = path->p_depth; 1083 *phys = 0; 1084 1085 if (depth == 0 && path->p_ext == NULL) 1086 return 0; 1087 1088 /* usually extent in the path covers blocks smaller 1089 * then *logical, but it can be that extent is the 1090 * first one in the file */ 1091 1092 ex = path[depth].p_ext; 1093 ee_len = ext4_ext_get_actual_len(ex); 1094 if (*logical < le32_to_cpu(ex->ee_block)) { 1095 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex); 1096 while (--depth >= 0) { 1097 ix = path[depth].p_idx; 1098 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr)); 1099 } 1100 *logical = le32_to_cpu(ex->ee_block); 1101 *phys = ext_pblock(ex); 1102 return 0; 1103 } 1104 1105 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len)); 1106 1107 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { 1108 /* next allocated block in this leaf */ 1109 ex++; 1110 *logical = le32_to_cpu(ex->ee_block); 1111 *phys = ext_pblock(ex); 1112 return 0; 1113 } 1114 1115 /* go up and search for index to the right */ 1116 while (--depth >= 0) { 1117 ix = path[depth].p_idx; 1118 if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) 1119 break; 1120 } 1121 1122 if (depth < 0) { 1123 /* we've gone up to the root and 1124 * found no index to the right */ 1125 return 0; 1126 } 1127 1128 /* we've found index to the right, let's 1129 * follow it and find the closest allocated 1130 * block to the right */ 1131 ix++; 1132 block = idx_pblock(ix); 1133 while (++depth < path->p_depth) { 1134 bh = sb_bread(inode->i_sb, block); 1135 if (bh == NULL) 1136 return -EIO; 1137 eh = ext_block_hdr(bh); 1138 if (ext4_ext_check_header(inode, eh, depth)) { 1139 put_bh(bh); 1140 return -EIO; 1141 } 1142 ix = EXT_FIRST_INDEX(eh); 1143 block = idx_pblock(ix); 1144 put_bh(bh); 1145 } 1146 1147 bh = sb_bread(inode->i_sb, block); 1148 if (bh == NULL) 1149 return -EIO; 1150 eh = ext_block_hdr(bh); 1151 if (ext4_ext_check_header(inode, eh, path->p_depth - depth)) { 1152 put_bh(bh); 1153 return -EIO; 1154 } 1155 ex = EXT_FIRST_EXTENT(eh); 1156 *logical = le32_to_cpu(ex->ee_block); 1157 *phys = ext_pblock(ex); 1158 put_bh(bh); 1159 return 0; 1160 1161 } 1162 1163 /* 1164 * ext4_ext_next_allocated_block: 1165 * returns allocated block in subsequent extent or EXT_MAX_BLOCK. 1166 * NOTE: it considers block number from index entry as 1167 * allocated block. Thus, index entries have to be consistent 1168 * with leaves. 1169 */ 1170 static ext4_lblk_t 1171 ext4_ext_next_allocated_block(struct ext4_ext_path *path) 1172 { 1173 int depth; 1174 1175 BUG_ON(path == NULL); 1176 depth = path->p_depth; 1177 1178 if (depth == 0 && path->p_ext == NULL) 1179 return EXT_MAX_BLOCK; 1180 1181 while (depth >= 0) { 1182 if (depth == path->p_depth) { 1183 /* leaf */ 1184 if (path[depth].p_ext != 1185 EXT_LAST_EXTENT(path[depth].p_hdr)) 1186 return le32_to_cpu(path[depth].p_ext[1].ee_block); 1187 } else { 1188 /* index */ 1189 if (path[depth].p_idx != 1190 EXT_LAST_INDEX(path[depth].p_hdr)) 1191 return le32_to_cpu(path[depth].p_idx[1].ei_block); 1192 } 1193 depth--; 1194 } 1195 1196 return EXT_MAX_BLOCK; 1197 } 1198 1199 /* 1200 * ext4_ext_next_leaf_block: 1201 * returns first allocated block from next leaf or EXT_MAX_BLOCK 1202 */ 1203 static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode, 1204 struct ext4_ext_path *path) 1205 { 1206 int depth; 1207 1208 BUG_ON(path == NULL); 1209 depth = path->p_depth; 1210 1211 /* zero-tree has no leaf blocks at all */ 1212 if (depth == 0) 1213 return EXT_MAX_BLOCK; 1214 1215 /* go to index block */ 1216 depth--; 1217 1218 while (depth >= 0) { 1219 if (path[depth].p_idx != 1220 EXT_LAST_INDEX(path[depth].p_hdr)) 1221 return (ext4_lblk_t) 1222 le32_to_cpu(path[depth].p_idx[1].ei_block); 1223 depth--; 1224 } 1225 1226 return EXT_MAX_BLOCK; 1227 } 1228 1229 /* 1230 * ext4_ext_correct_indexes: 1231 * if leaf gets modified and modified extent is first in the leaf, 1232 * then we have to correct all indexes above. 1233 * TODO: do we need to correct tree in all cases? 1234 */ 1235 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, 1236 struct ext4_ext_path *path) 1237 { 1238 struct ext4_extent_header *eh; 1239 int depth = ext_depth(inode); 1240 struct ext4_extent *ex; 1241 __le32 border; 1242 int k, err = 0; 1243 1244 eh = path[depth].p_hdr; 1245 ex = path[depth].p_ext; 1246 BUG_ON(ex == NULL); 1247 BUG_ON(eh == NULL); 1248 1249 if (depth == 0) { 1250 /* there is no tree at all */ 1251 return 0; 1252 } 1253 1254 if (ex != EXT_FIRST_EXTENT(eh)) { 1255 /* we correct tree if first leaf got modified only */ 1256 return 0; 1257 } 1258 1259 /* 1260 * TODO: we need correction if border is smaller than current one 1261 */ 1262 k = depth - 1; 1263 border = path[depth].p_ext->ee_block; 1264 err = ext4_ext_get_access(handle, inode, path + k); 1265 if (err) 1266 return err; 1267 path[k].p_idx->ei_block = border; 1268 err = ext4_ext_dirty(handle, inode, path + k); 1269 if (err) 1270 return err; 1271 1272 while (k--) { 1273 /* change all left-side indexes */ 1274 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) 1275 break; 1276 err = ext4_ext_get_access(handle, inode, path + k); 1277 if (err) 1278 break; 1279 path[k].p_idx->ei_block = border; 1280 err = ext4_ext_dirty(handle, inode, path + k); 1281 if (err) 1282 break; 1283 } 1284 1285 return err; 1286 } 1287 1288 static int 1289 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, 1290 struct ext4_extent *ex2) 1291 { 1292 unsigned short ext1_ee_len, ext2_ee_len, max_len; 1293 1294 /* 1295 * Make sure that either both extents are uninitialized, or 1296 * both are _not_. 1297 */ 1298 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2)) 1299 return 0; 1300 1301 if (ext4_ext_is_uninitialized(ex1)) 1302 max_len = EXT_UNINIT_MAX_LEN; 1303 else 1304 max_len = EXT_INIT_MAX_LEN; 1305 1306 ext1_ee_len = ext4_ext_get_actual_len(ex1); 1307 ext2_ee_len = ext4_ext_get_actual_len(ex2); 1308 1309 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != 1310 le32_to_cpu(ex2->ee_block)) 1311 return 0; 1312 1313 /* 1314 * To allow future support for preallocated extents to be added 1315 * as an RO_COMPAT feature, refuse to merge to extents if 1316 * this can result in the top bit of ee_len being set. 1317 */ 1318 if (ext1_ee_len + ext2_ee_len > max_len) 1319 return 0; 1320 #ifdef AGGRESSIVE_TEST 1321 if (ext1_ee_len >= 4) 1322 return 0; 1323 #endif 1324 1325 if (ext_pblock(ex1) + ext1_ee_len == ext_pblock(ex2)) 1326 return 1; 1327 return 0; 1328 } 1329 1330 /* 1331 * This function tries to merge the "ex" extent to the next extent in the tree. 1332 * It always tries to merge towards right. If you want to merge towards 1333 * left, pass "ex - 1" as argument instead of "ex". 1334 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns 1335 * 1 if they got merged. 1336 */ 1337 int ext4_ext_try_to_merge(struct inode *inode, 1338 struct ext4_ext_path *path, 1339 struct ext4_extent *ex) 1340 { 1341 struct ext4_extent_header *eh; 1342 unsigned int depth, len; 1343 int merge_done = 0; 1344 int uninitialized = 0; 1345 1346 depth = ext_depth(inode); 1347 BUG_ON(path[depth].p_hdr == NULL); 1348 eh = path[depth].p_hdr; 1349 1350 while (ex < EXT_LAST_EXTENT(eh)) { 1351 if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) 1352 break; 1353 /* merge with next extent! */ 1354 if (ext4_ext_is_uninitialized(ex)) 1355 uninitialized = 1; 1356 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 1357 + ext4_ext_get_actual_len(ex + 1)); 1358 if (uninitialized) 1359 ext4_ext_mark_uninitialized(ex); 1360 1361 if (ex + 1 < EXT_LAST_EXTENT(eh)) { 1362 len = (EXT_LAST_EXTENT(eh) - ex - 1) 1363 * sizeof(struct ext4_extent); 1364 memmove(ex + 1, ex + 2, len); 1365 } 1366 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries) - 1); 1367 merge_done = 1; 1368 WARN_ON(eh->eh_entries == 0); 1369 if (!eh->eh_entries) 1370 ext4_error(inode->i_sb, "ext4_ext_try_to_merge", 1371 "inode#%lu, eh->eh_entries = 0!", inode->i_ino); 1372 } 1373 1374 return merge_done; 1375 } 1376 1377 /* 1378 * check if a portion of the "newext" extent overlaps with an 1379 * existing extent. 1380 * 1381 * If there is an overlap discovered, it updates the length of the newext 1382 * such that there will be no overlap, and then returns 1. 1383 * If there is no overlap found, it returns 0. 1384 */ 1385 unsigned int ext4_ext_check_overlap(struct inode *inode, 1386 struct ext4_extent *newext, 1387 struct ext4_ext_path *path) 1388 { 1389 ext4_lblk_t b1, b2; 1390 unsigned int depth, len1; 1391 unsigned int ret = 0; 1392 1393 b1 = le32_to_cpu(newext->ee_block); 1394 len1 = ext4_ext_get_actual_len(newext); 1395 depth = ext_depth(inode); 1396 if (!path[depth].p_ext) 1397 goto out; 1398 b2 = le32_to_cpu(path[depth].p_ext->ee_block); 1399 1400 /* 1401 * get the next allocated block if the extent in the path 1402 * is before the requested block(s) 1403 */ 1404 if (b2 < b1) { 1405 b2 = ext4_ext_next_allocated_block(path); 1406 if (b2 == EXT_MAX_BLOCK) 1407 goto out; 1408 } 1409 1410 /* check for wrap through zero on extent logical start block*/ 1411 if (b1 + len1 < b1) { 1412 len1 = EXT_MAX_BLOCK - b1; 1413 newext->ee_len = cpu_to_le16(len1); 1414 ret = 1; 1415 } 1416 1417 /* check for overlap */ 1418 if (b1 + len1 > b2) { 1419 newext->ee_len = cpu_to_le16(b2 - b1); 1420 ret = 1; 1421 } 1422 out: 1423 return ret; 1424 } 1425 1426 /* 1427 * ext4_ext_insert_extent: 1428 * tries to merge requsted extent into the existing extent or 1429 * inserts requested extent as new one into the tree, 1430 * creating new leaf in the no-space case. 1431 */ 1432 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, 1433 struct ext4_ext_path *path, 1434 struct ext4_extent *newext) 1435 { 1436 struct ext4_extent_header * eh; 1437 struct ext4_extent *ex, *fex; 1438 struct ext4_extent *nearex; /* nearest extent */ 1439 struct ext4_ext_path *npath = NULL; 1440 int depth, len, err; 1441 ext4_lblk_t next; 1442 unsigned uninitialized = 0; 1443 1444 BUG_ON(ext4_ext_get_actual_len(newext) == 0); 1445 depth = ext_depth(inode); 1446 ex = path[depth].p_ext; 1447 BUG_ON(path[depth].p_hdr == NULL); 1448 1449 /* try to insert block into found extent and return */ 1450 if (ex && ext4_can_extents_be_merged(inode, ex, newext)) { 1451 ext_debug("append %d block to %d:%d (from %llu)\n", 1452 ext4_ext_get_actual_len(newext), 1453 le32_to_cpu(ex->ee_block), 1454 ext4_ext_get_actual_len(ex), ext_pblock(ex)); 1455 err = ext4_ext_get_access(handle, inode, path + depth); 1456 if (err) 1457 return err; 1458 1459 /* 1460 * ext4_can_extents_be_merged should have checked that either 1461 * both extents are uninitialized, or both aren't. Thus we 1462 * need to check only one of them here. 1463 */ 1464 if (ext4_ext_is_uninitialized(ex)) 1465 uninitialized = 1; 1466 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 1467 + ext4_ext_get_actual_len(newext)); 1468 if (uninitialized) 1469 ext4_ext_mark_uninitialized(ex); 1470 eh = path[depth].p_hdr; 1471 nearex = ex; 1472 goto merge; 1473 } 1474 1475 repeat: 1476 depth = ext_depth(inode); 1477 eh = path[depth].p_hdr; 1478 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) 1479 goto has_space; 1480 1481 /* probably next leaf has space for us? */ 1482 fex = EXT_LAST_EXTENT(eh); 1483 next = ext4_ext_next_leaf_block(inode, path); 1484 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block) 1485 && next != EXT_MAX_BLOCK) { 1486 ext_debug("next leaf block - %d\n", next); 1487 BUG_ON(npath != NULL); 1488 npath = ext4_ext_find_extent(inode, next, NULL); 1489 if (IS_ERR(npath)) 1490 return PTR_ERR(npath); 1491 BUG_ON(npath->p_depth != path->p_depth); 1492 eh = npath[depth].p_hdr; 1493 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { 1494 ext_debug("next leaf isnt full(%d)\n", 1495 le16_to_cpu(eh->eh_entries)); 1496 path = npath; 1497 goto repeat; 1498 } 1499 ext_debug("next leaf has no free space(%d,%d)\n", 1500 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); 1501 } 1502 1503 /* 1504 * There is no free space in the found leaf. 1505 * We're gonna add a new leaf in the tree. 1506 */ 1507 err = ext4_ext_create_new_leaf(handle, inode, path, newext); 1508 if (err) 1509 goto cleanup; 1510 depth = ext_depth(inode); 1511 eh = path[depth].p_hdr; 1512 1513 has_space: 1514 nearex = path[depth].p_ext; 1515 1516 err = ext4_ext_get_access(handle, inode, path + depth); 1517 if (err) 1518 goto cleanup; 1519 1520 if (!nearex) { 1521 /* there is no extent in this leaf, create first one */ 1522 ext_debug("first extent in the leaf: %d:%llu:%d\n", 1523 le32_to_cpu(newext->ee_block), 1524 ext_pblock(newext), 1525 ext4_ext_get_actual_len(newext)); 1526 path[depth].p_ext = EXT_FIRST_EXTENT(eh); 1527 } else if (le32_to_cpu(newext->ee_block) 1528 > le32_to_cpu(nearex->ee_block)) { 1529 /* BUG_ON(newext->ee_block == nearex->ee_block); */ 1530 if (nearex != EXT_LAST_EXTENT(eh)) { 1531 len = EXT_MAX_EXTENT(eh) - nearex; 1532 len = (len - 1) * sizeof(struct ext4_extent); 1533 len = len < 0 ? 0 : len; 1534 ext_debug("insert %d:%llu:%d after: nearest 0x%p, " 1535 "move %d from 0x%p to 0x%p\n", 1536 le32_to_cpu(newext->ee_block), 1537 ext_pblock(newext), 1538 ext4_ext_get_actual_len(newext), 1539 nearex, len, nearex + 1, nearex + 2); 1540 memmove(nearex + 2, nearex + 1, len); 1541 } 1542 path[depth].p_ext = nearex + 1; 1543 } else { 1544 BUG_ON(newext->ee_block == nearex->ee_block); 1545 len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent); 1546 len = len < 0 ? 0 : len; 1547 ext_debug("insert %d:%llu:%d before: nearest 0x%p, " 1548 "move %d from 0x%p to 0x%p\n", 1549 le32_to_cpu(newext->ee_block), 1550 ext_pblock(newext), 1551 ext4_ext_get_actual_len(newext), 1552 nearex, len, nearex + 1, nearex + 2); 1553 memmove(nearex + 1, nearex, len); 1554 path[depth].p_ext = nearex; 1555 } 1556 1557 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)+1); 1558 nearex = path[depth].p_ext; 1559 nearex->ee_block = newext->ee_block; 1560 ext4_ext_store_pblock(nearex, ext_pblock(newext)); 1561 nearex->ee_len = newext->ee_len; 1562 1563 merge: 1564 /* try to merge extents to the right */ 1565 ext4_ext_try_to_merge(inode, path, nearex); 1566 1567 /* try to merge extents to the left */ 1568 1569 /* time to correct all indexes above */ 1570 err = ext4_ext_correct_indexes(handle, inode, path); 1571 if (err) 1572 goto cleanup; 1573 1574 err = ext4_ext_dirty(handle, inode, path + depth); 1575 1576 cleanup: 1577 if (npath) { 1578 ext4_ext_drop_refs(npath); 1579 kfree(npath); 1580 } 1581 ext4_ext_tree_changed(inode); 1582 ext4_ext_invalidate_cache(inode); 1583 return err; 1584 } 1585 1586 static void 1587 ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block, 1588 __u32 len, ext4_fsblk_t start, int type) 1589 { 1590 struct ext4_ext_cache *cex; 1591 BUG_ON(len == 0); 1592 cex = &EXT4_I(inode)->i_cached_extent; 1593 cex->ec_type = type; 1594 cex->ec_block = block; 1595 cex->ec_len = len; 1596 cex->ec_start = start; 1597 } 1598 1599 /* 1600 * ext4_ext_put_gap_in_cache: 1601 * calculate boundaries of the gap that the requested block fits into 1602 * and cache this gap 1603 */ 1604 static void 1605 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, 1606 ext4_lblk_t block) 1607 { 1608 int depth = ext_depth(inode); 1609 unsigned long len; 1610 ext4_lblk_t lblock; 1611 struct ext4_extent *ex; 1612 1613 ex = path[depth].p_ext; 1614 if (ex == NULL) { 1615 /* there is no extent yet, so gap is [0;-] */ 1616 lblock = 0; 1617 len = EXT_MAX_BLOCK; 1618 ext_debug("cache gap(whole file):"); 1619 } else if (block < le32_to_cpu(ex->ee_block)) { 1620 lblock = block; 1621 len = le32_to_cpu(ex->ee_block) - block; 1622 ext_debug("cache gap(before): %u [%u:%u]", 1623 block, 1624 le32_to_cpu(ex->ee_block), 1625 ext4_ext_get_actual_len(ex)); 1626 } else if (block >= le32_to_cpu(ex->ee_block) 1627 + ext4_ext_get_actual_len(ex)) { 1628 ext4_lblk_t next; 1629 lblock = le32_to_cpu(ex->ee_block) 1630 + ext4_ext_get_actual_len(ex); 1631 1632 next = ext4_ext_next_allocated_block(path); 1633 ext_debug("cache gap(after): [%u:%u] %u", 1634 le32_to_cpu(ex->ee_block), 1635 ext4_ext_get_actual_len(ex), 1636 block); 1637 BUG_ON(next == lblock); 1638 len = next - lblock; 1639 } else { 1640 lblock = len = 0; 1641 BUG(); 1642 } 1643 1644 ext_debug(" -> %u:%lu\n", lblock, len); 1645 ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP); 1646 } 1647 1648 static int 1649 ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, 1650 struct ext4_extent *ex) 1651 { 1652 struct ext4_ext_cache *cex; 1653 1654 cex = &EXT4_I(inode)->i_cached_extent; 1655 1656 /* has cache valid data? */ 1657 if (cex->ec_type == EXT4_EXT_CACHE_NO) 1658 return EXT4_EXT_CACHE_NO; 1659 1660 BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP && 1661 cex->ec_type != EXT4_EXT_CACHE_EXTENT); 1662 if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) { 1663 ex->ee_block = cpu_to_le32(cex->ec_block); 1664 ext4_ext_store_pblock(ex, cex->ec_start); 1665 ex->ee_len = cpu_to_le16(cex->ec_len); 1666 ext_debug("%u cached by %u:%u:%llu\n", 1667 block, 1668 cex->ec_block, cex->ec_len, cex->ec_start); 1669 return cex->ec_type; 1670 } 1671 1672 /* not in cache */ 1673 return EXT4_EXT_CACHE_NO; 1674 } 1675 1676 /* 1677 * ext4_ext_rm_idx: 1678 * removes index from the index block. 1679 * It's used in truncate case only, thus all requests are for 1680 * last index in the block only. 1681 */ 1682 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, 1683 struct ext4_ext_path *path) 1684 { 1685 struct buffer_head *bh; 1686 int err; 1687 ext4_fsblk_t leaf; 1688 1689 /* free index block */ 1690 path--; 1691 leaf = idx_pblock(path->p_idx); 1692 BUG_ON(path->p_hdr->eh_entries == 0); 1693 err = ext4_ext_get_access(handle, inode, path); 1694 if (err) 1695 return err; 1696 path->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path->p_hdr->eh_entries)-1); 1697 err = ext4_ext_dirty(handle, inode, path); 1698 if (err) 1699 return err; 1700 ext_debug("index is empty, remove it, free block %llu\n", leaf); 1701 bh = sb_find_get_block(inode->i_sb, leaf); 1702 ext4_forget(handle, 1, inode, bh, leaf); 1703 ext4_free_blocks(handle, inode, leaf, 1, 1); 1704 return err; 1705 } 1706 1707 /* 1708 * ext4_ext_calc_credits_for_insert: 1709 * This routine returns max. credits that the extent tree can consume. 1710 * It should be OK for low-performance paths like ->writepage() 1711 * To allow many writing processes to fit into a single transaction, 1712 * the caller should calculate credits under i_data_sem and 1713 * pass the actual path. 1714 */ 1715 int ext4_ext_calc_credits_for_insert(struct inode *inode, 1716 struct ext4_ext_path *path) 1717 { 1718 int depth, needed; 1719 1720 if (path) { 1721 /* probably there is space in leaf? */ 1722 depth = ext_depth(inode); 1723 if (le16_to_cpu(path[depth].p_hdr->eh_entries) 1724 < le16_to_cpu(path[depth].p_hdr->eh_max)) 1725 return 1; 1726 } 1727 1728 /* 1729 * given 32-bit logical block (4294967296 blocks), max. tree 1730 * can be 4 levels in depth -- 4 * 340^4 == 53453440000. 1731 * Let's also add one more level for imbalance. 1732 */ 1733 depth = 5; 1734 1735 /* allocation of new data block(s) */ 1736 needed = 2; 1737 1738 /* 1739 * tree can be full, so it would need to grow in depth: 1740 * we need one credit to modify old root, credits for 1741 * new root will be added in split accounting 1742 */ 1743 needed += 1; 1744 1745 /* 1746 * Index split can happen, we would need: 1747 * allocate intermediate indexes (bitmap + group) 1748 * + change two blocks at each level, but root (already included) 1749 */ 1750 needed += (depth * 2) + (depth * 2); 1751 1752 /* any allocation modifies superblock */ 1753 needed += 1; 1754 1755 return needed; 1756 } 1757 1758 static int ext4_remove_blocks(handle_t *handle, struct inode *inode, 1759 struct ext4_extent *ex, 1760 ext4_lblk_t from, ext4_lblk_t to) 1761 { 1762 struct buffer_head *bh; 1763 unsigned short ee_len = ext4_ext_get_actual_len(ex); 1764 int i, metadata = 0; 1765 1766 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) 1767 metadata = 1; 1768 #ifdef EXTENTS_STATS 1769 { 1770 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 1771 spin_lock(&sbi->s_ext_stats_lock); 1772 sbi->s_ext_blocks += ee_len; 1773 sbi->s_ext_extents++; 1774 if (ee_len < sbi->s_ext_min) 1775 sbi->s_ext_min = ee_len; 1776 if (ee_len > sbi->s_ext_max) 1777 sbi->s_ext_max = ee_len; 1778 if (ext_depth(inode) > sbi->s_depth_max) 1779 sbi->s_depth_max = ext_depth(inode); 1780 spin_unlock(&sbi->s_ext_stats_lock); 1781 } 1782 #endif 1783 if (from >= le32_to_cpu(ex->ee_block) 1784 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) { 1785 /* tail removal */ 1786 ext4_lblk_t num; 1787 ext4_fsblk_t start; 1788 1789 num = le32_to_cpu(ex->ee_block) + ee_len - from; 1790 start = ext_pblock(ex) + ee_len - num; 1791 ext_debug("free last %u blocks starting %llu\n", num, start); 1792 for (i = 0; i < num; i++) { 1793 bh = sb_find_get_block(inode->i_sb, start + i); 1794 ext4_forget(handle, 0, inode, bh, start + i); 1795 } 1796 ext4_free_blocks(handle, inode, start, num, metadata); 1797 } else if (from == le32_to_cpu(ex->ee_block) 1798 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) { 1799 printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n", 1800 from, to, le32_to_cpu(ex->ee_block), ee_len); 1801 } else { 1802 printk(KERN_INFO "strange request: removal(2) " 1803 "%u-%u from %u:%u\n", 1804 from, to, le32_to_cpu(ex->ee_block), ee_len); 1805 } 1806 return 0; 1807 } 1808 1809 static int 1810 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, 1811 struct ext4_ext_path *path, ext4_lblk_t start) 1812 { 1813 int err = 0, correct_index = 0; 1814 int depth = ext_depth(inode), credits; 1815 struct ext4_extent_header *eh; 1816 ext4_lblk_t a, b, block; 1817 unsigned num; 1818 ext4_lblk_t ex_ee_block; 1819 unsigned short ex_ee_len; 1820 unsigned uninitialized = 0; 1821 struct ext4_extent *ex; 1822 1823 /* the header must be checked already in ext4_ext_remove_space() */ 1824 ext_debug("truncate since %u in leaf\n", start); 1825 if (!path[depth].p_hdr) 1826 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); 1827 eh = path[depth].p_hdr; 1828 BUG_ON(eh == NULL); 1829 1830 /* find where to start removing */ 1831 ex = EXT_LAST_EXTENT(eh); 1832 1833 ex_ee_block = le32_to_cpu(ex->ee_block); 1834 if (ext4_ext_is_uninitialized(ex)) 1835 uninitialized = 1; 1836 ex_ee_len = ext4_ext_get_actual_len(ex); 1837 1838 while (ex >= EXT_FIRST_EXTENT(eh) && 1839 ex_ee_block + ex_ee_len > start) { 1840 ext_debug("remove ext %lu:%u\n", ex_ee_block, ex_ee_len); 1841 path[depth].p_ext = ex; 1842 1843 a = ex_ee_block > start ? ex_ee_block : start; 1844 b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ? 1845 ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK; 1846 1847 ext_debug(" border %u:%u\n", a, b); 1848 1849 if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { 1850 block = 0; 1851 num = 0; 1852 BUG(); 1853 } else if (a != ex_ee_block) { 1854 /* remove tail of the extent */ 1855 block = ex_ee_block; 1856 num = a - block; 1857 } else if (b != ex_ee_block + ex_ee_len - 1) { 1858 /* remove head of the extent */ 1859 block = a; 1860 num = b - a; 1861 /* there is no "make a hole" API yet */ 1862 BUG(); 1863 } else { 1864 /* remove whole extent: excellent! */ 1865 block = ex_ee_block; 1866 num = 0; 1867 BUG_ON(a != ex_ee_block); 1868 BUG_ON(b != ex_ee_block + ex_ee_len - 1); 1869 } 1870 1871 /* at present, extent can't cross block group: */ 1872 /* leaf + bitmap + group desc + sb + inode */ 1873 credits = 5; 1874 if (ex == EXT_FIRST_EXTENT(eh)) { 1875 correct_index = 1; 1876 credits += (ext_depth(inode)) + 1; 1877 } 1878 #ifdef CONFIG_QUOTA 1879 credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); 1880 #endif 1881 1882 handle = ext4_ext_journal_restart(handle, credits); 1883 if (IS_ERR(handle)) { 1884 err = PTR_ERR(handle); 1885 goto out; 1886 } 1887 1888 err = ext4_ext_get_access(handle, inode, path + depth); 1889 if (err) 1890 goto out; 1891 1892 err = ext4_remove_blocks(handle, inode, ex, a, b); 1893 if (err) 1894 goto out; 1895 1896 if (num == 0) { 1897 /* this extent is removed; mark slot entirely unused */ 1898 ext4_ext_store_pblock(ex, 0); 1899 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1); 1900 } 1901 1902 ex->ee_block = cpu_to_le32(block); 1903 ex->ee_len = cpu_to_le16(num); 1904 /* 1905 * Do not mark uninitialized if all the blocks in the 1906 * extent have been removed. 1907 */ 1908 if (uninitialized && num) 1909 ext4_ext_mark_uninitialized(ex); 1910 1911 err = ext4_ext_dirty(handle, inode, path + depth); 1912 if (err) 1913 goto out; 1914 1915 ext_debug("new extent: %u:%u:%llu\n", block, num, 1916 ext_pblock(ex)); 1917 ex--; 1918 ex_ee_block = le32_to_cpu(ex->ee_block); 1919 ex_ee_len = ext4_ext_get_actual_len(ex); 1920 } 1921 1922 if (correct_index && eh->eh_entries) 1923 err = ext4_ext_correct_indexes(handle, inode, path); 1924 1925 /* if this leaf is free, then we should 1926 * remove it from index block above */ 1927 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) 1928 err = ext4_ext_rm_idx(handle, inode, path + depth); 1929 1930 out: 1931 return err; 1932 } 1933 1934 /* 1935 * ext4_ext_more_to_rm: 1936 * returns 1 if current index has to be freed (even partial) 1937 */ 1938 static int 1939 ext4_ext_more_to_rm(struct ext4_ext_path *path) 1940 { 1941 BUG_ON(path->p_idx == NULL); 1942 1943 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) 1944 return 0; 1945 1946 /* 1947 * if truncate on deeper level happened, it wasn't partial, 1948 * so we have to consider current index for truncation 1949 */ 1950 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) 1951 return 0; 1952 return 1; 1953 } 1954 1955 static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) 1956 { 1957 struct super_block *sb = inode->i_sb; 1958 int depth = ext_depth(inode); 1959 struct ext4_ext_path *path; 1960 handle_t *handle; 1961 int i = 0, err = 0; 1962 1963 ext_debug("truncate since %u\n", start); 1964 1965 /* probably first extent we're gonna free will be last in block */ 1966 handle = ext4_journal_start(inode, depth + 1); 1967 if (IS_ERR(handle)) 1968 return PTR_ERR(handle); 1969 1970 ext4_ext_invalidate_cache(inode); 1971 1972 /* 1973 * We start scanning from right side, freeing all the blocks 1974 * after i_size and walking into the tree depth-wise. 1975 */ 1976 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL); 1977 if (path == NULL) { 1978 ext4_journal_stop(handle); 1979 return -ENOMEM; 1980 } 1981 path[0].p_hdr = ext_inode_hdr(inode); 1982 if (ext4_ext_check_header(inode, path[0].p_hdr, depth)) { 1983 err = -EIO; 1984 goto out; 1985 } 1986 path[0].p_depth = depth; 1987 1988 while (i >= 0 && err == 0) { 1989 if (i == depth) { 1990 /* this is leaf block */ 1991 err = ext4_ext_rm_leaf(handle, inode, path, start); 1992 /* root level has p_bh == NULL, brelse() eats this */ 1993 brelse(path[i].p_bh); 1994 path[i].p_bh = NULL; 1995 i--; 1996 continue; 1997 } 1998 1999 /* this is index block */ 2000 if (!path[i].p_hdr) { 2001 ext_debug("initialize header\n"); 2002 path[i].p_hdr = ext_block_hdr(path[i].p_bh); 2003 } 2004 2005 if (!path[i].p_idx) { 2006 /* this level hasn't been touched yet */ 2007 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); 2008 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; 2009 ext_debug("init index ptr: hdr 0x%p, num %d\n", 2010 path[i].p_hdr, 2011 le16_to_cpu(path[i].p_hdr->eh_entries)); 2012 } else { 2013 /* we were already here, see at next index */ 2014 path[i].p_idx--; 2015 } 2016 2017 ext_debug("level %d - index, first 0x%p, cur 0x%p\n", 2018 i, EXT_FIRST_INDEX(path[i].p_hdr), 2019 path[i].p_idx); 2020 if (ext4_ext_more_to_rm(path + i)) { 2021 struct buffer_head *bh; 2022 /* go to the next level */ 2023 ext_debug("move to level %d (block %llu)\n", 2024 i + 1, idx_pblock(path[i].p_idx)); 2025 memset(path + i + 1, 0, sizeof(*path)); 2026 bh = sb_bread(sb, idx_pblock(path[i].p_idx)); 2027 if (!bh) { 2028 /* should we reset i_size? */ 2029 err = -EIO; 2030 break; 2031 } 2032 if (WARN_ON(i + 1 > depth)) { 2033 err = -EIO; 2034 break; 2035 } 2036 if (ext4_ext_check_header(inode, ext_block_hdr(bh), 2037 depth - i - 1)) { 2038 err = -EIO; 2039 break; 2040 } 2041 path[i + 1].p_bh = bh; 2042 2043 /* save actual number of indexes since this 2044 * number is changed at the next iteration */ 2045 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); 2046 i++; 2047 } else { 2048 /* we finished processing this index, go up */ 2049 if (path[i].p_hdr->eh_entries == 0 && i > 0) { 2050 /* index is empty, remove it; 2051 * handle must be already prepared by the 2052 * truncatei_leaf() */ 2053 err = ext4_ext_rm_idx(handle, inode, path + i); 2054 } 2055 /* root level has p_bh == NULL, brelse() eats this */ 2056 brelse(path[i].p_bh); 2057 path[i].p_bh = NULL; 2058 i--; 2059 ext_debug("return to level %d\n", i); 2060 } 2061 } 2062 2063 /* TODO: flexible tree reduction should be here */ 2064 if (path->p_hdr->eh_entries == 0) { 2065 /* 2066 * truncate to zero freed all the tree, 2067 * so we need to correct eh_depth 2068 */ 2069 err = ext4_ext_get_access(handle, inode, path); 2070 if (err == 0) { 2071 ext_inode_hdr(inode)->eh_depth = 0; 2072 ext_inode_hdr(inode)->eh_max = 2073 cpu_to_le16(ext4_ext_space_root(inode)); 2074 err = ext4_ext_dirty(handle, inode, path); 2075 } 2076 } 2077 out: 2078 ext4_ext_tree_changed(inode); 2079 ext4_ext_drop_refs(path); 2080 kfree(path); 2081 ext4_journal_stop(handle); 2082 2083 return err; 2084 } 2085 2086 /* 2087 * called at mount time 2088 */ 2089 void ext4_ext_init(struct super_block *sb) 2090 { 2091 /* 2092 * possible initialization would be here 2093 */ 2094 2095 if (test_opt(sb, EXTENTS)) { 2096 printk("EXT4-fs: file extents enabled"); 2097 #ifdef AGGRESSIVE_TEST 2098 printk(", aggressive tests"); 2099 #endif 2100 #ifdef CHECK_BINSEARCH 2101 printk(", check binsearch"); 2102 #endif 2103 #ifdef EXTENTS_STATS 2104 printk(", stats"); 2105 #endif 2106 printk("\n"); 2107 #ifdef EXTENTS_STATS 2108 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); 2109 EXT4_SB(sb)->s_ext_min = 1 << 30; 2110 EXT4_SB(sb)->s_ext_max = 0; 2111 #endif 2112 } 2113 } 2114 2115 /* 2116 * called at umount time 2117 */ 2118 void ext4_ext_release(struct super_block *sb) 2119 { 2120 if (!test_opt(sb, EXTENTS)) 2121 return; 2122 2123 #ifdef EXTENTS_STATS 2124 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { 2125 struct ext4_sb_info *sbi = EXT4_SB(sb); 2126 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", 2127 sbi->s_ext_blocks, sbi->s_ext_extents, 2128 sbi->s_ext_blocks / sbi->s_ext_extents); 2129 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", 2130 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); 2131 } 2132 #endif 2133 } 2134 2135 /* 2136 * This function is called by ext4_ext_get_blocks() if someone tries to write 2137 * to an uninitialized extent. It may result in splitting the uninitialized 2138 * extent into multiple extents (upto three - one initialized and two 2139 * uninitialized). 2140 * There are three possibilities: 2141 * a> There is no split required: Entire extent should be initialized 2142 * b> Splits in two extents: Write is happening at either end of the extent 2143 * c> Splits in three extents: Somone is writing in middle of the extent 2144 */ 2145 static int ext4_ext_convert_to_initialized(handle_t *handle, 2146 struct inode *inode, 2147 struct ext4_ext_path *path, 2148 ext4_lblk_t iblock, 2149 unsigned long max_blocks) 2150 { 2151 struct ext4_extent *ex, newex; 2152 struct ext4_extent *ex1 = NULL; 2153 struct ext4_extent *ex2 = NULL; 2154 struct ext4_extent *ex3 = NULL; 2155 struct ext4_extent_header *eh; 2156 ext4_lblk_t ee_block; 2157 unsigned int allocated, ee_len, depth; 2158 ext4_fsblk_t newblock; 2159 int err = 0; 2160 int ret = 0; 2161 2162 depth = ext_depth(inode); 2163 eh = path[depth].p_hdr; 2164 ex = path[depth].p_ext; 2165 ee_block = le32_to_cpu(ex->ee_block); 2166 ee_len = ext4_ext_get_actual_len(ex); 2167 allocated = ee_len - (iblock - ee_block); 2168 newblock = iblock - ee_block + ext_pblock(ex); 2169 ex2 = ex; 2170 2171 /* ex1: ee_block to iblock - 1 : uninitialized */ 2172 if (iblock > ee_block) { 2173 ex1 = ex; 2174 ex1->ee_len = cpu_to_le16(iblock - ee_block); 2175 ext4_ext_mark_uninitialized(ex1); 2176 ex2 = &newex; 2177 } 2178 /* 2179 * for sanity, update the length of the ex2 extent before 2180 * we insert ex3, if ex1 is NULL. This is to avoid temporary 2181 * overlap of blocks. 2182 */ 2183 if (!ex1 && allocated > max_blocks) 2184 ex2->ee_len = cpu_to_le16(max_blocks); 2185 /* ex3: to ee_block + ee_len : uninitialised */ 2186 if (allocated > max_blocks) { 2187 unsigned int newdepth; 2188 ex3 = &newex; 2189 ex3->ee_block = cpu_to_le32(iblock + max_blocks); 2190 ext4_ext_store_pblock(ex3, newblock + max_blocks); 2191 ex3->ee_len = cpu_to_le16(allocated - max_blocks); 2192 ext4_ext_mark_uninitialized(ex3); 2193 err = ext4_ext_insert_extent(handle, inode, path, ex3); 2194 if (err) 2195 goto out; 2196 /* 2197 * The depth, and hence eh & ex might change 2198 * as part of the insert above. 2199 */ 2200 newdepth = ext_depth(inode); 2201 if (newdepth != depth) { 2202 depth = newdepth; 2203 path = ext4_ext_find_extent(inode, iblock, NULL); 2204 if (IS_ERR(path)) { 2205 err = PTR_ERR(path); 2206 path = NULL; 2207 goto out; 2208 } 2209 eh = path[depth].p_hdr; 2210 ex = path[depth].p_ext; 2211 if (ex2 != &newex) 2212 ex2 = ex; 2213 } 2214 allocated = max_blocks; 2215 } 2216 /* 2217 * If there was a change of depth as part of the 2218 * insertion of ex3 above, we need to update the length 2219 * of the ex1 extent again here 2220 */ 2221 if (ex1 && ex1 != ex) { 2222 ex1 = ex; 2223 ex1->ee_len = cpu_to_le16(iblock - ee_block); 2224 ext4_ext_mark_uninitialized(ex1); 2225 ex2 = &newex; 2226 } 2227 /* ex2: iblock to iblock + maxblocks-1 : initialised */ 2228 ex2->ee_block = cpu_to_le32(iblock); 2229 ext4_ext_store_pblock(ex2, newblock); 2230 ex2->ee_len = cpu_to_le16(allocated); 2231 if (ex2 != ex) 2232 goto insert; 2233 err = ext4_ext_get_access(handle, inode, path + depth); 2234 if (err) 2235 goto out; 2236 /* 2237 * New (initialized) extent starts from the first block 2238 * in the current extent. i.e., ex2 == ex 2239 * We have to see if it can be merged with the extent 2240 * on the left. 2241 */ 2242 if (ex2 > EXT_FIRST_EXTENT(eh)) { 2243 /* 2244 * To merge left, pass "ex2 - 1" to try_to_merge(), 2245 * since it merges towards right _only_. 2246 */ 2247 ret = ext4_ext_try_to_merge(inode, path, ex2 - 1); 2248 if (ret) { 2249 err = ext4_ext_correct_indexes(handle, inode, path); 2250 if (err) 2251 goto out; 2252 depth = ext_depth(inode); 2253 ex2--; 2254 } 2255 } 2256 /* 2257 * Try to Merge towards right. This might be required 2258 * only when the whole extent is being written to. 2259 * i.e. ex2 == ex and ex3 == NULL. 2260 */ 2261 if (!ex3) { 2262 ret = ext4_ext_try_to_merge(inode, path, ex2); 2263 if (ret) { 2264 err = ext4_ext_correct_indexes(handle, inode, path); 2265 if (err) 2266 goto out; 2267 } 2268 } 2269 /* Mark modified extent as dirty */ 2270 err = ext4_ext_dirty(handle, inode, path + depth); 2271 goto out; 2272 insert: 2273 err = ext4_ext_insert_extent(handle, inode, path, &newex); 2274 out: 2275 return err ? err : allocated; 2276 } 2277 2278 /* 2279 * Need to be called with 2280 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block 2281 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) 2282 */ 2283 int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, 2284 ext4_lblk_t iblock, 2285 unsigned long max_blocks, struct buffer_head *bh_result, 2286 int create, int extend_disksize) 2287 { 2288 struct ext4_ext_path *path = NULL; 2289 struct ext4_extent_header *eh; 2290 struct ext4_extent newex, *ex; 2291 ext4_fsblk_t goal, newblock; 2292 int err = 0, depth, ret; 2293 unsigned long allocated = 0; 2294 struct ext4_allocation_request ar; 2295 2296 __clear_bit(BH_New, &bh_result->b_state); 2297 ext_debug("blocks %u/%lu requested for inode %u\n", 2298 iblock, max_blocks, inode->i_ino); 2299 2300 /* check in cache */ 2301 goal = ext4_ext_in_cache(inode, iblock, &newex); 2302 if (goal) { 2303 if (goal == EXT4_EXT_CACHE_GAP) { 2304 if (!create) { 2305 /* 2306 * block isn't allocated yet and 2307 * user doesn't want to allocate it 2308 */ 2309 goto out2; 2310 } 2311 /* we should allocate requested block */ 2312 } else if (goal == EXT4_EXT_CACHE_EXTENT) { 2313 /* block is already allocated */ 2314 newblock = iblock 2315 - le32_to_cpu(newex.ee_block) 2316 + ext_pblock(&newex); 2317 /* number of remaining blocks in the extent */ 2318 allocated = ext4_ext_get_actual_len(&newex) - 2319 (iblock - le32_to_cpu(newex.ee_block)); 2320 goto out; 2321 } else { 2322 BUG(); 2323 } 2324 } 2325 2326 /* find extent for this block */ 2327 path = ext4_ext_find_extent(inode, iblock, NULL); 2328 if (IS_ERR(path)) { 2329 err = PTR_ERR(path); 2330 path = NULL; 2331 goto out2; 2332 } 2333 2334 depth = ext_depth(inode); 2335 2336 /* 2337 * consistent leaf must not be empty; 2338 * this situation is possible, though, _during_ tree modification; 2339 * this is why assert can't be put in ext4_ext_find_extent() 2340 */ 2341 BUG_ON(path[depth].p_ext == NULL && depth != 0); 2342 eh = path[depth].p_hdr; 2343 2344 ex = path[depth].p_ext; 2345 if (ex) { 2346 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); 2347 ext4_fsblk_t ee_start = ext_pblock(ex); 2348 unsigned short ee_len; 2349 2350 /* 2351 * Uninitialized extents are treated as holes, except that 2352 * we split out initialized portions during a write. 2353 */ 2354 ee_len = ext4_ext_get_actual_len(ex); 2355 /* if found extent covers block, simply return it */ 2356 if (iblock >= ee_block && iblock < ee_block + ee_len) { 2357 newblock = iblock - ee_block + ee_start; 2358 /* number of remaining blocks in the extent */ 2359 allocated = ee_len - (iblock - ee_block); 2360 ext_debug("%u fit into %lu:%d -> %llu\n", iblock, 2361 ee_block, ee_len, newblock); 2362 2363 /* Do not put uninitialized extent in the cache */ 2364 if (!ext4_ext_is_uninitialized(ex)) { 2365 ext4_ext_put_in_cache(inode, ee_block, 2366 ee_len, ee_start, 2367 EXT4_EXT_CACHE_EXTENT); 2368 goto out; 2369 } 2370 if (create == EXT4_CREATE_UNINITIALIZED_EXT) 2371 goto out; 2372 if (!create) 2373 goto out2; 2374 2375 ret = ext4_ext_convert_to_initialized(handle, inode, 2376 path, iblock, 2377 max_blocks); 2378 if (ret <= 0) { 2379 err = ret; 2380 goto out2; 2381 } else 2382 allocated = ret; 2383 goto outnew; 2384 } 2385 } 2386 2387 /* 2388 * requested block isn't allocated yet; 2389 * we couldn't try to create block if create flag is zero 2390 */ 2391 if (!create) { 2392 /* 2393 * put just found gap into cache to speed up 2394 * subsequent requests 2395 */ 2396 ext4_ext_put_gap_in_cache(inode, path, iblock); 2397 goto out2; 2398 } 2399 /* 2400 * Okay, we need to do block allocation. Lazily initialize the block 2401 * allocation info here if necessary. 2402 */ 2403 if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info)) 2404 ext4_init_block_alloc_info(inode); 2405 2406 /* find neighbour allocated blocks */ 2407 ar.lleft = iblock; 2408 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); 2409 if (err) 2410 goto out2; 2411 ar.lright = iblock; 2412 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright); 2413 if (err) 2414 goto out2; 2415 2416 /* 2417 * See if request is beyond maximum number of blocks we can have in 2418 * a single extent. For an initialized extent this limit is 2419 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is 2420 * EXT_UNINIT_MAX_LEN. 2421 */ 2422 if (max_blocks > EXT_INIT_MAX_LEN && 2423 create != EXT4_CREATE_UNINITIALIZED_EXT) 2424 max_blocks = EXT_INIT_MAX_LEN; 2425 else if (max_blocks > EXT_UNINIT_MAX_LEN && 2426 create == EXT4_CREATE_UNINITIALIZED_EXT) 2427 max_blocks = EXT_UNINIT_MAX_LEN; 2428 2429 /* Check if we can really insert (iblock)::(iblock+max_blocks) extent */ 2430 newex.ee_block = cpu_to_le32(iblock); 2431 newex.ee_len = cpu_to_le16(max_blocks); 2432 err = ext4_ext_check_overlap(inode, &newex, path); 2433 if (err) 2434 allocated = ext4_ext_get_actual_len(&newex); 2435 else 2436 allocated = max_blocks; 2437 2438 /* allocate new block */ 2439 ar.inode = inode; 2440 ar.goal = ext4_ext_find_goal(inode, path, iblock); 2441 ar.logical = iblock; 2442 ar.len = allocated; 2443 if (S_ISREG(inode->i_mode)) 2444 ar.flags = EXT4_MB_HINT_DATA; 2445 else 2446 /* disable in-core preallocation for non-regular files */ 2447 ar.flags = 0; 2448 newblock = ext4_mb_new_blocks(handle, &ar, &err); 2449 if (!newblock) 2450 goto out2; 2451 ext_debug("allocate new block: goal %llu, found %llu/%lu\n", 2452 goal, newblock, allocated); 2453 2454 /* try to insert new extent into found leaf and return */ 2455 ext4_ext_store_pblock(&newex, newblock); 2456 newex.ee_len = cpu_to_le16(ar.len); 2457 if (create == EXT4_CREATE_UNINITIALIZED_EXT) /* Mark uninitialized */ 2458 ext4_ext_mark_uninitialized(&newex); 2459 err = ext4_ext_insert_extent(handle, inode, path, &newex); 2460 if (err) { 2461 /* free data blocks we just allocated */ 2462 /* not a good idea to call discard here directly, 2463 * but otherwise we'd need to call it every free() */ 2464 ext4_mb_discard_inode_preallocations(inode); 2465 ext4_free_blocks(handle, inode, ext_pblock(&newex), 2466 ext4_ext_get_actual_len(&newex), 0); 2467 goto out2; 2468 } 2469 2470 if (extend_disksize && inode->i_size > EXT4_I(inode)->i_disksize) 2471 EXT4_I(inode)->i_disksize = inode->i_size; 2472 2473 /* previous routine could use block we allocated */ 2474 newblock = ext_pblock(&newex); 2475 allocated = ext4_ext_get_actual_len(&newex); 2476 outnew: 2477 __set_bit(BH_New, &bh_result->b_state); 2478 2479 /* Cache only when it is _not_ an uninitialized extent */ 2480 if (create != EXT4_CREATE_UNINITIALIZED_EXT) 2481 ext4_ext_put_in_cache(inode, iblock, allocated, newblock, 2482 EXT4_EXT_CACHE_EXTENT); 2483 out: 2484 if (allocated > max_blocks) 2485 allocated = max_blocks; 2486 ext4_ext_show_leaf(inode, path); 2487 __set_bit(BH_Mapped, &bh_result->b_state); 2488 bh_result->b_bdev = inode->i_sb->s_bdev; 2489 bh_result->b_blocknr = newblock; 2490 out2: 2491 if (path) { 2492 ext4_ext_drop_refs(path); 2493 kfree(path); 2494 } 2495 return err ? err : allocated; 2496 } 2497 2498 void ext4_ext_truncate(struct inode * inode, struct page *page) 2499 { 2500 struct address_space *mapping = inode->i_mapping; 2501 struct super_block *sb = inode->i_sb; 2502 ext4_lblk_t last_block; 2503 handle_t *handle; 2504 int err = 0; 2505 2506 /* 2507 * probably first extent we're gonna free will be last in block 2508 */ 2509 err = ext4_writepage_trans_blocks(inode) + 3; 2510 handle = ext4_journal_start(inode, err); 2511 if (IS_ERR(handle)) { 2512 if (page) { 2513 clear_highpage(page); 2514 flush_dcache_page(page); 2515 unlock_page(page); 2516 page_cache_release(page); 2517 } 2518 return; 2519 } 2520 2521 if (page) 2522 ext4_block_truncate_page(handle, page, mapping, inode->i_size); 2523 2524 down_write(&EXT4_I(inode)->i_data_sem); 2525 ext4_ext_invalidate_cache(inode); 2526 2527 ext4_mb_discard_inode_preallocations(inode); 2528 2529 /* 2530 * TODO: optimization is possible here. 2531 * Probably we need not scan at all, 2532 * because page truncation is enough. 2533 */ 2534 if (ext4_orphan_add(handle, inode)) 2535 goto out_stop; 2536 2537 /* we have to know where to truncate from in crash case */ 2538 EXT4_I(inode)->i_disksize = inode->i_size; 2539 ext4_mark_inode_dirty(handle, inode); 2540 2541 last_block = (inode->i_size + sb->s_blocksize - 1) 2542 >> EXT4_BLOCK_SIZE_BITS(sb); 2543 err = ext4_ext_remove_space(inode, last_block); 2544 2545 /* In a multi-transaction truncate, we only make the final 2546 * transaction synchronous. 2547 */ 2548 if (IS_SYNC(inode)) 2549 handle->h_sync = 1; 2550 2551 out_stop: 2552 /* 2553 * If this was a simple ftruncate() and the file will remain alive, 2554 * then we need to clear up the orphan record which we created above. 2555 * However, if this was a real unlink then we were called by 2556 * ext4_delete_inode(), and we allow that function to clean up the 2557 * orphan info for us. 2558 */ 2559 if (inode->i_nlink) 2560 ext4_orphan_del(handle, inode); 2561 2562 up_write(&EXT4_I(inode)->i_data_sem); 2563 ext4_journal_stop(handle); 2564 } 2565 2566 /* 2567 * ext4_ext_writepage_trans_blocks: 2568 * calculate max number of blocks we could modify 2569 * in order to allocate new block for an inode 2570 */ 2571 int ext4_ext_writepage_trans_blocks(struct inode *inode, int num) 2572 { 2573 int needed; 2574 2575 needed = ext4_ext_calc_credits_for_insert(inode, NULL); 2576 2577 /* caller wants to allocate num blocks, but note it includes sb */ 2578 needed = needed * num - (num - 1); 2579 2580 #ifdef CONFIG_QUOTA 2581 needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); 2582 #endif 2583 2584 return needed; 2585 } 2586 2587 /* 2588 * preallocate space for a file. This implements ext4's fallocate inode 2589 * operation, which gets called from sys_fallocate system call. 2590 * For block-mapped files, posix_fallocate should fall back to the method 2591 * of writing zeroes to the required new blocks (the same behavior which is 2592 * expected for file systems which do not support fallocate() system call). 2593 */ 2594 long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len) 2595 { 2596 handle_t *handle; 2597 ext4_lblk_t block; 2598 unsigned long max_blocks; 2599 ext4_fsblk_t nblocks = 0; 2600 int ret = 0; 2601 int ret2 = 0; 2602 int retries = 0; 2603 struct buffer_head map_bh; 2604 unsigned int credits, blkbits = inode->i_blkbits; 2605 2606 /* 2607 * currently supporting (pre)allocate mode for extent-based 2608 * files _only_ 2609 */ 2610 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) 2611 return -EOPNOTSUPP; 2612 2613 /* preallocation to directories is currently not supported */ 2614 if (S_ISDIR(inode->i_mode)) 2615 return -ENODEV; 2616 2617 block = offset >> blkbits; 2618 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) 2619 - block; 2620 2621 /* 2622 * credits to insert 1 extent into extent tree + buffers to be able to 2623 * modify 1 super block, 1 block bitmap and 1 group descriptor. 2624 */ 2625 credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3; 2626 down_write((&EXT4_I(inode)->i_data_sem)); 2627 retry: 2628 while (ret >= 0 && ret < max_blocks) { 2629 block = block + ret; 2630 max_blocks = max_blocks - ret; 2631 handle = ext4_journal_start(inode, credits); 2632 if (IS_ERR(handle)) { 2633 ret = PTR_ERR(handle); 2634 break; 2635 } 2636 2637 ret = ext4_ext_get_blocks(handle, inode, block, 2638 max_blocks, &map_bh, 2639 EXT4_CREATE_UNINITIALIZED_EXT, 0); 2640 WARN_ON(ret <= 0); 2641 if (ret <= 0) { 2642 ext4_error(inode->i_sb, "ext4_fallocate", 2643 "ext4_ext_get_blocks returned error: " 2644 "inode#%lu, block=%u, max_blocks=%lu", 2645 inode->i_ino, block, max_blocks); 2646 ret = -EIO; 2647 ext4_mark_inode_dirty(handle, inode); 2648 ret2 = ext4_journal_stop(handle); 2649 break; 2650 } 2651 if (ret > 0) { 2652 /* check wrap through sign-bit/zero here */ 2653 if ((block + ret) < 0 || (block + ret) < block) { 2654 ret = -EIO; 2655 ext4_mark_inode_dirty(handle, inode); 2656 ret2 = ext4_journal_stop(handle); 2657 break; 2658 } 2659 if (buffer_new(&map_bh) && ((block + ret) > 2660 (EXT4_BLOCK_ALIGN(i_size_read(inode), blkbits) 2661 >> blkbits))) 2662 nblocks = nblocks + ret; 2663 } 2664 2665 /* Update ctime if new blocks get allocated */ 2666 if (nblocks) { 2667 struct timespec now; 2668 2669 now = current_fs_time(inode->i_sb); 2670 if (!timespec_equal(&inode->i_ctime, &now)) 2671 inode->i_ctime = now; 2672 } 2673 2674 ext4_mark_inode_dirty(handle, inode); 2675 ret2 = ext4_journal_stop(handle); 2676 if (ret2) 2677 break; 2678 } 2679 2680 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) 2681 goto retry; 2682 2683 up_write((&EXT4_I(inode)->i_data_sem)); 2684 /* 2685 * Time to update the file size. 2686 * Update only when preallocation was requested beyond the file size. 2687 */ 2688 if (!(mode & FALLOC_FL_KEEP_SIZE) && 2689 (offset + len) > i_size_read(inode)) { 2690 if (ret > 0) { 2691 /* 2692 * if no error, we assume preallocation succeeded 2693 * completely 2694 */ 2695 mutex_lock(&inode->i_mutex); 2696 i_size_write(inode, offset + len); 2697 EXT4_I(inode)->i_disksize = i_size_read(inode); 2698 mutex_unlock(&inode->i_mutex); 2699 } else if (ret < 0 && nblocks) { 2700 /* Handle partial allocation scenario */ 2701 loff_t newsize; 2702 2703 mutex_lock(&inode->i_mutex); 2704 newsize = (nblocks << blkbits) + i_size_read(inode); 2705 i_size_write(inode, EXT4_BLOCK_ALIGN(newsize, blkbits)); 2706 EXT4_I(inode)->i_disksize = i_size_read(inode); 2707 mutex_unlock(&inode->i_mutex); 2708 } 2709 } 2710 2711 return ret > 0 ? ret2 : ret; 2712 } 2713