1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com 4 * Written by Alex Tomas <alex@clusterfs.com> 5 * 6 * Architecture independence: 7 * Copyright (c) 2005, Bull S.A. 8 * Written by Pierre Peiffer <pierre.peiffer@bull.net> 9 */ 10 11 /* 12 * Extents support for EXT4 13 * 14 * TODO: 15 * - ext4*_error() should be used in some situations 16 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate 17 * - smart tree reduction 18 */ 19 20 #include <linux/fs.h> 21 #include <linux/time.h> 22 #include <linux/jbd2.h> 23 #include <linux/highuid.h> 24 #include <linux/pagemap.h> 25 #include <linux/quotaops.h> 26 #include <linux/string.h> 27 #include <linux/slab.h> 28 #include <linux/uaccess.h> 29 #include <linux/fiemap.h> 30 #include <linux/backing-dev.h> 31 #include <linux/iomap.h> 32 #include "ext4_jbd2.h" 33 #include "ext4_extents.h" 34 #include "xattr.h" 35 36 #include <trace/events/ext4.h> 37 38 /* 39 * used by extent splitting. 40 */ 41 #define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \ 42 due to ENOSPC */ 43 #define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */ 44 #define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */ 45 46 #define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */ 47 #define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */ 48 49 static __le32 ext4_extent_block_csum(struct inode *inode, 50 struct ext4_extent_header *eh) 51 { 52 struct ext4_inode_info *ei = EXT4_I(inode); 53 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 54 __u32 csum; 55 56 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh, 57 EXT4_EXTENT_TAIL_OFFSET(eh)); 58 return cpu_to_le32(csum); 59 } 60 61 static int ext4_extent_block_csum_verify(struct inode *inode, 62 struct ext4_extent_header *eh) 63 { 64 struct ext4_extent_tail *et; 65 66 if (!ext4_has_metadata_csum(inode->i_sb)) 67 return 1; 68 69 et = find_ext4_extent_tail(eh); 70 if (et->et_checksum != ext4_extent_block_csum(inode, eh)) 71 return 0; 72 return 1; 73 } 74 75 static void ext4_extent_block_csum_set(struct inode *inode, 76 struct ext4_extent_header *eh) 77 { 78 struct ext4_extent_tail *et; 79 80 if (!ext4_has_metadata_csum(inode->i_sb)) 81 return; 82 83 et = find_ext4_extent_tail(eh); 84 et->et_checksum = ext4_extent_block_csum(inode, eh); 85 } 86 87 static int ext4_split_extent_at(handle_t *handle, 88 struct inode *inode, 89 struct ext4_ext_path **ppath, 90 ext4_lblk_t split, 91 int split_flag, 92 int flags); 93 94 static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped) 95 { 96 /* 97 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this 98 * moment, get_block can be called only for blocks inside i_size since 99 * page cache has been already dropped and writes are blocked by 100 * i_mutex. So we can safely drop the i_data_sem here. 101 */ 102 BUG_ON(EXT4_JOURNAL(inode) == NULL); 103 ext4_discard_preallocations(inode, 0); 104 up_write(&EXT4_I(inode)->i_data_sem); 105 *dropped = 1; 106 return 0; 107 } 108 109 /* 110 * Make sure 'handle' has at least 'check_cred' credits. If not, restart 111 * transaction with 'restart_cred' credits. The function drops i_data_sem 112 * when restarting transaction and gets it after transaction is restarted. 113 * 114 * The function returns 0 on success, 1 if transaction had to be restarted, 115 * and < 0 in case of fatal error. 116 */ 117 int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode, 118 int check_cred, int restart_cred, 119 int revoke_cred) 120 { 121 int ret; 122 int dropped = 0; 123 124 ret = ext4_journal_ensure_credits_fn(handle, check_cred, restart_cred, 125 revoke_cred, ext4_ext_trunc_restart_fn(inode, &dropped)); 126 if (dropped) 127 down_write(&EXT4_I(inode)->i_data_sem); 128 return ret; 129 } 130 131 /* 132 * could return: 133 * - EROFS 134 * - ENOMEM 135 */ 136 static int ext4_ext_get_access(handle_t *handle, struct inode *inode, 137 struct ext4_ext_path *path) 138 { 139 if (path->p_bh) { 140 /* path points to block */ 141 BUFFER_TRACE(path->p_bh, "get_write_access"); 142 return ext4_journal_get_write_access(handle, path->p_bh); 143 } 144 /* path points to leaf/index in inode body */ 145 /* we use in-core data, no need to protect them */ 146 return 0; 147 } 148 149 /* 150 * could return: 151 * - EROFS 152 * - ENOMEM 153 * - EIO 154 */ 155 static int __ext4_ext_dirty(const char *where, unsigned int line, 156 handle_t *handle, struct inode *inode, 157 struct ext4_ext_path *path) 158 { 159 int err; 160 161 WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem)); 162 if (path->p_bh) { 163 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh)); 164 /* path points to block */ 165 err = __ext4_handle_dirty_metadata(where, line, handle, 166 inode, path->p_bh); 167 } else { 168 /* path points to leaf/index in inode body */ 169 err = ext4_mark_inode_dirty(handle, inode); 170 } 171 return err; 172 } 173 174 #define ext4_ext_dirty(handle, inode, path) \ 175 __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path)) 176 177 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, 178 struct ext4_ext_path *path, 179 ext4_lblk_t block) 180 { 181 if (path) { 182 int depth = path->p_depth; 183 struct ext4_extent *ex; 184 185 /* 186 * Try to predict block placement assuming that we are 187 * filling in a file which will eventually be 188 * non-sparse --- i.e., in the case of libbfd writing 189 * an ELF object sections out-of-order but in a way 190 * the eventually results in a contiguous object or 191 * executable file, or some database extending a table 192 * space file. However, this is actually somewhat 193 * non-ideal if we are writing a sparse file such as 194 * qemu or KVM writing a raw image file that is going 195 * to stay fairly sparse, since it will end up 196 * fragmenting the file system's free space. Maybe we 197 * should have some hueristics or some way to allow 198 * userspace to pass a hint to file system, 199 * especially if the latter case turns out to be 200 * common. 201 */ 202 ex = path[depth].p_ext; 203 if (ex) { 204 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex); 205 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block); 206 207 if (block > ext_block) 208 return ext_pblk + (block - ext_block); 209 else 210 return ext_pblk - (ext_block - block); 211 } 212 213 /* it looks like index is empty; 214 * try to find starting block from index itself */ 215 if (path[depth].p_bh) 216 return path[depth].p_bh->b_blocknr; 217 } 218 219 /* OK. use inode's group */ 220 return ext4_inode_to_goal_block(inode); 221 } 222 223 /* 224 * Allocation for a meta data block 225 */ 226 static ext4_fsblk_t 227 ext4_ext_new_meta_block(handle_t *handle, struct inode *inode, 228 struct ext4_ext_path *path, 229 struct ext4_extent *ex, int *err, unsigned int flags) 230 { 231 ext4_fsblk_t goal, newblock; 232 233 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); 234 newblock = ext4_new_meta_blocks(handle, inode, goal, flags, 235 NULL, err); 236 return newblock; 237 } 238 239 static inline int ext4_ext_space_block(struct inode *inode, int check) 240 { 241 int size; 242 243 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 244 / sizeof(struct ext4_extent); 245 #ifdef AGGRESSIVE_TEST 246 if (!check && size > 6) 247 size = 6; 248 #endif 249 return size; 250 } 251 252 static inline int ext4_ext_space_block_idx(struct inode *inode, int check) 253 { 254 int size; 255 256 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 257 / sizeof(struct ext4_extent_idx); 258 #ifdef AGGRESSIVE_TEST 259 if (!check && size > 5) 260 size = 5; 261 #endif 262 return size; 263 } 264 265 static inline int ext4_ext_space_root(struct inode *inode, int check) 266 { 267 int size; 268 269 size = sizeof(EXT4_I(inode)->i_data); 270 size -= sizeof(struct ext4_extent_header); 271 size /= sizeof(struct ext4_extent); 272 #ifdef AGGRESSIVE_TEST 273 if (!check && size > 3) 274 size = 3; 275 #endif 276 return size; 277 } 278 279 static inline int ext4_ext_space_root_idx(struct inode *inode, int check) 280 { 281 int size; 282 283 size = sizeof(EXT4_I(inode)->i_data); 284 size -= sizeof(struct ext4_extent_header); 285 size /= sizeof(struct ext4_extent_idx); 286 #ifdef AGGRESSIVE_TEST 287 if (!check && size > 4) 288 size = 4; 289 #endif 290 return size; 291 } 292 293 static inline int 294 ext4_force_split_extent_at(handle_t *handle, struct inode *inode, 295 struct ext4_ext_path **ppath, ext4_lblk_t lblk, 296 int nofail) 297 { 298 struct ext4_ext_path *path = *ppath; 299 int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext); 300 int flags = EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO; 301 302 if (nofail) 303 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL | EXT4_EX_NOFAIL; 304 305 return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ? 306 EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0, 307 flags); 308 } 309 310 static int 311 ext4_ext_max_entries(struct inode *inode, int depth) 312 { 313 int max; 314 315 if (depth == ext_depth(inode)) { 316 if (depth == 0) 317 max = ext4_ext_space_root(inode, 1); 318 else 319 max = ext4_ext_space_root_idx(inode, 1); 320 } else { 321 if (depth == 0) 322 max = ext4_ext_space_block(inode, 1); 323 else 324 max = ext4_ext_space_block_idx(inode, 1); 325 } 326 327 return max; 328 } 329 330 static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) 331 { 332 ext4_fsblk_t block = ext4_ext_pblock(ext); 333 int len = ext4_ext_get_actual_len(ext); 334 ext4_lblk_t lblock = le32_to_cpu(ext->ee_block); 335 336 /* 337 * We allow neither: 338 * - zero length 339 * - overflow/wrap-around 340 */ 341 if (lblock + len <= lblock) 342 return 0; 343 return ext4_inode_block_valid(inode, block, len); 344 } 345 346 static int ext4_valid_extent_idx(struct inode *inode, 347 struct ext4_extent_idx *ext_idx) 348 { 349 ext4_fsblk_t block = ext4_idx_pblock(ext_idx); 350 351 return ext4_inode_block_valid(inode, block, 1); 352 } 353 354 static int ext4_valid_extent_entries(struct inode *inode, 355 struct ext4_extent_header *eh, 356 ext4_fsblk_t *pblk, int depth) 357 { 358 unsigned short entries; 359 if (eh->eh_entries == 0) 360 return 1; 361 362 entries = le16_to_cpu(eh->eh_entries); 363 364 if (depth == 0) { 365 /* leaf entries */ 366 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh); 367 ext4_lblk_t lblock = 0; 368 ext4_lblk_t prev = 0; 369 int len = 0; 370 while (entries) { 371 if (!ext4_valid_extent(inode, ext)) 372 return 0; 373 374 /* Check for overlapping extents */ 375 lblock = le32_to_cpu(ext->ee_block); 376 len = ext4_ext_get_actual_len(ext); 377 if ((lblock <= prev) && prev) { 378 *pblk = ext4_ext_pblock(ext); 379 return 0; 380 } 381 ext++; 382 entries--; 383 prev = lblock + len - 1; 384 } 385 } else { 386 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh); 387 while (entries) { 388 if (!ext4_valid_extent_idx(inode, ext_idx)) 389 return 0; 390 ext_idx++; 391 entries--; 392 } 393 } 394 return 1; 395 } 396 397 static int __ext4_ext_check(const char *function, unsigned int line, 398 struct inode *inode, struct ext4_extent_header *eh, 399 int depth, ext4_fsblk_t pblk) 400 { 401 const char *error_msg; 402 int max = 0, err = -EFSCORRUPTED; 403 404 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { 405 error_msg = "invalid magic"; 406 goto corrupted; 407 } 408 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { 409 error_msg = "unexpected eh_depth"; 410 goto corrupted; 411 } 412 if (unlikely(eh->eh_max == 0)) { 413 error_msg = "invalid eh_max"; 414 goto corrupted; 415 } 416 max = ext4_ext_max_entries(inode, depth); 417 if (unlikely(le16_to_cpu(eh->eh_max) > max)) { 418 error_msg = "too large eh_max"; 419 goto corrupted; 420 } 421 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { 422 error_msg = "invalid eh_entries"; 423 goto corrupted; 424 } 425 if (!ext4_valid_extent_entries(inode, eh, &pblk, depth)) { 426 error_msg = "invalid extent entries"; 427 goto corrupted; 428 } 429 if (unlikely(depth > 32)) { 430 error_msg = "too large eh_depth"; 431 goto corrupted; 432 } 433 /* Verify checksum on non-root extent tree nodes */ 434 if (ext_depth(inode) != depth && 435 !ext4_extent_block_csum_verify(inode, eh)) { 436 error_msg = "extent tree corrupted"; 437 err = -EFSBADCRC; 438 goto corrupted; 439 } 440 return 0; 441 442 corrupted: 443 ext4_error_inode_err(inode, function, line, 0, -err, 444 "pblk %llu bad header/extent: %s - magic %x, " 445 "entries %u, max %u(%u), depth %u(%u)", 446 (unsigned long long) pblk, error_msg, 447 le16_to_cpu(eh->eh_magic), 448 le16_to_cpu(eh->eh_entries), 449 le16_to_cpu(eh->eh_max), 450 max, le16_to_cpu(eh->eh_depth), depth); 451 return err; 452 } 453 454 #define ext4_ext_check(inode, eh, depth, pblk) \ 455 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk)) 456 457 int ext4_ext_check_inode(struct inode *inode) 458 { 459 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0); 460 } 461 462 static void ext4_cache_extents(struct inode *inode, 463 struct ext4_extent_header *eh) 464 { 465 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh); 466 ext4_lblk_t prev = 0; 467 int i; 468 469 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) { 470 unsigned int status = EXTENT_STATUS_WRITTEN; 471 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block); 472 int len = ext4_ext_get_actual_len(ex); 473 474 if (prev && (prev != lblk)) 475 ext4_es_cache_extent(inode, prev, lblk - prev, ~0, 476 EXTENT_STATUS_HOLE); 477 478 if (ext4_ext_is_unwritten(ex)) 479 status = EXTENT_STATUS_UNWRITTEN; 480 ext4_es_cache_extent(inode, lblk, len, 481 ext4_ext_pblock(ex), status); 482 prev = lblk + len; 483 } 484 } 485 486 static struct buffer_head * 487 __read_extent_tree_block(const char *function, unsigned int line, 488 struct inode *inode, ext4_fsblk_t pblk, int depth, 489 int flags) 490 { 491 struct buffer_head *bh; 492 int err; 493 gfp_t gfp_flags = __GFP_MOVABLE | GFP_NOFS; 494 495 if (flags & EXT4_EX_NOFAIL) 496 gfp_flags |= __GFP_NOFAIL; 497 498 bh = sb_getblk_gfp(inode->i_sb, pblk, gfp_flags); 499 if (unlikely(!bh)) 500 return ERR_PTR(-ENOMEM); 501 502 if (!bh_uptodate_or_lock(bh)) { 503 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_); 504 err = ext4_read_bh(bh, 0, NULL); 505 if (err < 0) 506 goto errout; 507 } 508 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE)) 509 return bh; 510 err = __ext4_ext_check(function, line, inode, 511 ext_block_hdr(bh), depth, pblk); 512 if (err) 513 goto errout; 514 set_buffer_verified(bh); 515 /* 516 * If this is a leaf block, cache all of its entries 517 */ 518 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) { 519 struct ext4_extent_header *eh = ext_block_hdr(bh); 520 ext4_cache_extents(inode, eh); 521 } 522 return bh; 523 errout: 524 put_bh(bh); 525 return ERR_PTR(err); 526 527 } 528 529 #define read_extent_tree_block(inode, pblk, depth, flags) \ 530 __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \ 531 (depth), (flags)) 532 533 /* 534 * This function is called to cache a file's extent information in the 535 * extent status tree 536 */ 537 int ext4_ext_precache(struct inode *inode) 538 { 539 struct ext4_inode_info *ei = EXT4_I(inode); 540 struct ext4_ext_path *path = NULL; 541 struct buffer_head *bh; 542 int i = 0, depth, ret = 0; 543 544 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) 545 return 0; /* not an extent-mapped inode */ 546 547 down_read(&ei->i_data_sem); 548 depth = ext_depth(inode); 549 550 /* Don't cache anything if there are no external extent blocks */ 551 if (!depth) { 552 up_read(&ei->i_data_sem); 553 return ret; 554 } 555 556 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path), 557 GFP_NOFS); 558 if (path == NULL) { 559 up_read(&ei->i_data_sem); 560 return -ENOMEM; 561 } 562 563 path[0].p_hdr = ext_inode_hdr(inode); 564 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0); 565 if (ret) 566 goto out; 567 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr); 568 while (i >= 0) { 569 /* 570 * If this is a leaf block or we've reached the end of 571 * the index block, go up 572 */ 573 if ((i == depth) || 574 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) { 575 brelse(path[i].p_bh); 576 path[i].p_bh = NULL; 577 i--; 578 continue; 579 } 580 bh = read_extent_tree_block(inode, 581 ext4_idx_pblock(path[i].p_idx++), 582 depth - i - 1, 583 EXT4_EX_FORCE_CACHE); 584 if (IS_ERR(bh)) { 585 ret = PTR_ERR(bh); 586 break; 587 } 588 i++; 589 path[i].p_bh = bh; 590 path[i].p_hdr = ext_block_hdr(bh); 591 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr); 592 } 593 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED); 594 out: 595 up_read(&ei->i_data_sem); 596 ext4_ext_drop_refs(path); 597 kfree(path); 598 return ret; 599 } 600 601 #ifdef EXT_DEBUG 602 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) 603 { 604 int k, l = path->p_depth; 605 606 ext_debug(inode, "path:"); 607 for (k = 0; k <= l; k++, path++) { 608 if (path->p_idx) { 609 ext_debug(inode, " %d->%llu", 610 le32_to_cpu(path->p_idx->ei_block), 611 ext4_idx_pblock(path->p_idx)); 612 } else if (path->p_ext) { 613 ext_debug(inode, " %d:[%d]%d:%llu ", 614 le32_to_cpu(path->p_ext->ee_block), 615 ext4_ext_is_unwritten(path->p_ext), 616 ext4_ext_get_actual_len(path->p_ext), 617 ext4_ext_pblock(path->p_ext)); 618 } else 619 ext_debug(inode, " []"); 620 } 621 ext_debug(inode, "\n"); 622 } 623 624 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) 625 { 626 int depth = ext_depth(inode); 627 struct ext4_extent_header *eh; 628 struct ext4_extent *ex; 629 int i; 630 631 if (!path) 632 return; 633 634 eh = path[depth].p_hdr; 635 ex = EXT_FIRST_EXTENT(eh); 636 637 ext_debug(inode, "Displaying leaf extents\n"); 638 639 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { 640 ext_debug(inode, "%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block), 641 ext4_ext_is_unwritten(ex), 642 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); 643 } 644 ext_debug(inode, "\n"); 645 } 646 647 static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path, 648 ext4_fsblk_t newblock, int level) 649 { 650 int depth = ext_depth(inode); 651 struct ext4_extent *ex; 652 653 if (depth != level) { 654 struct ext4_extent_idx *idx; 655 idx = path[level].p_idx; 656 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) { 657 ext_debug(inode, "%d: move %d:%llu in new index %llu\n", 658 level, le32_to_cpu(idx->ei_block), 659 ext4_idx_pblock(idx), newblock); 660 idx++; 661 } 662 663 return; 664 } 665 666 ex = path[depth].p_ext; 667 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) { 668 ext_debug(inode, "move %d:%llu:[%d]%d in new leaf %llu\n", 669 le32_to_cpu(ex->ee_block), 670 ext4_ext_pblock(ex), 671 ext4_ext_is_unwritten(ex), 672 ext4_ext_get_actual_len(ex), 673 newblock); 674 ex++; 675 } 676 } 677 678 #else 679 #define ext4_ext_show_path(inode, path) 680 #define ext4_ext_show_leaf(inode, path) 681 #define ext4_ext_show_move(inode, path, newblock, level) 682 #endif 683 684 void ext4_ext_drop_refs(struct ext4_ext_path *path) 685 { 686 int depth, i; 687 688 if (!path) 689 return; 690 depth = path->p_depth; 691 for (i = 0; i <= depth; i++, path++) { 692 brelse(path->p_bh); 693 path->p_bh = NULL; 694 } 695 } 696 697 /* 698 * ext4_ext_binsearch_idx: 699 * binary search for the closest index of the given block 700 * the header must be checked before calling this 701 */ 702 static void 703 ext4_ext_binsearch_idx(struct inode *inode, 704 struct ext4_ext_path *path, ext4_lblk_t block) 705 { 706 struct ext4_extent_header *eh = path->p_hdr; 707 struct ext4_extent_idx *r, *l, *m; 708 709 710 ext_debug(inode, "binsearch for %u(idx): ", block); 711 712 l = EXT_FIRST_INDEX(eh) + 1; 713 r = EXT_LAST_INDEX(eh); 714 while (l <= r) { 715 m = l + (r - l) / 2; 716 if (block < le32_to_cpu(m->ei_block)) 717 r = m - 1; 718 else 719 l = m + 1; 720 ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l, 721 le32_to_cpu(l->ei_block), m, le32_to_cpu(m->ei_block), 722 r, le32_to_cpu(r->ei_block)); 723 } 724 725 path->p_idx = l - 1; 726 ext_debug(inode, " -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block), 727 ext4_idx_pblock(path->p_idx)); 728 729 #ifdef CHECK_BINSEARCH 730 { 731 struct ext4_extent_idx *chix, *ix; 732 int k; 733 734 chix = ix = EXT_FIRST_INDEX(eh); 735 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { 736 if (k != 0 && le32_to_cpu(ix->ei_block) <= 737 le32_to_cpu(ix[-1].ei_block)) { 738 printk(KERN_DEBUG "k=%d, ix=0x%p, " 739 "first=0x%p\n", k, 740 ix, EXT_FIRST_INDEX(eh)); 741 printk(KERN_DEBUG "%u <= %u\n", 742 le32_to_cpu(ix->ei_block), 743 le32_to_cpu(ix[-1].ei_block)); 744 } 745 BUG_ON(k && le32_to_cpu(ix->ei_block) 746 <= le32_to_cpu(ix[-1].ei_block)); 747 if (block < le32_to_cpu(ix->ei_block)) 748 break; 749 chix = ix; 750 } 751 BUG_ON(chix != path->p_idx); 752 } 753 #endif 754 755 } 756 757 /* 758 * ext4_ext_binsearch: 759 * binary search for closest extent of the given block 760 * the header must be checked before calling this 761 */ 762 static void 763 ext4_ext_binsearch(struct inode *inode, 764 struct ext4_ext_path *path, ext4_lblk_t block) 765 { 766 struct ext4_extent_header *eh = path->p_hdr; 767 struct ext4_extent *r, *l, *m; 768 769 if (eh->eh_entries == 0) { 770 /* 771 * this leaf is empty: 772 * we get such a leaf in split/add case 773 */ 774 return; 775 } 776 777 ext_debug(inode, "binsearch for %u: ", block); 778 779 l = EXT_FIRST_EXTENT(eh) + 1; 780 r = EXT_LAST_EXTENT(eh); 781 782 while (l <= r) { 783 m = l + (r - l) / 2; 784 if (block < le32_to_cpu(m->ee_block)) 785 r = m - 1; 786 else 787 l = m + 1; 788 ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l, 789 le32_to_cpu(l->ee_block), m, le32_to_cpu(m->ee_block), 790 r, le32_to_cpu(r->ee_block)); 791 } 792 793 path->p_ext = l - 1; 794 ext_debug(inode, " -> %d:%llu:[%d]%d ", 795 le32_to_cpu(path->p_ext->ee_block), 796 ext4_ext_pblock(path->p_ext), 797 ext4_ext_is_unwritten(path->p_ext), 798 ext4_ext_get_actual_len(path->p_ext)); 799 800 #ifdef CHECK_BINSEARCH 801 { 802 struct ext4_extent *chex, *ex; 803 int k; 804 805 chex = ex = EXT_FIRST_EXTENT(eh); 806 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { 807 BUG_ON(k && le32_to_cpu(ex->ee_block) 808 <= le32_to_cpu(ex[-1].ee_block)); 809 if (block < le32_to_cpu(ex->ee_block)) 810 break; 811 chex = ex; 812 } 813 BUG_ON(chex != path->p_ext); 814 } 815 #endif 816 817 } 818 819 void ext4_ext_tree_init(handle_t *handle, struct inode *inode) 820 { 821 struct ext4_extent_header *eh; 822 823 eh = ext_inode_hdr(inode); 824 eh->eh_depth = 0; 825 eh->eh_entries = 0; 826 eh->eh_magic = EXT4_EXT_MAGIC; 827 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); 828 ext4_mark_inode_dirty(handle, inode); 829 } 830 831 struct ext4_ext_path * 832 ext4_find_extent(struct inode *inode, ext4_lblk_t block, 833 struct ext4_ext_path **orig_path, int flags) 834 { 835 struct ext4_extent_header *eh; 836 struct buffer_head *bh; 837 struct ext4_ext_path *path = orig_path ? *orig_path : NULL; 838 short int depth, i, ppos = 0; 839 int ret; 840 gfp_t gfp_flags = GFP_NOFS; 841 842 if (flags & EXT4_EX_NOFAIL) 843 gfp_flags |= __GFP_NOFAIL; 844 845 eh = ext_inode_hdr(inode); 846 depth = ext_depth(inode); 847 if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) { 848 EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d", 849 depth); 850 ret = -EFSCORRUPTED; 851 goto err; 852 } 853 854 if (path) { 855 ext4_ext_drop_refs(path); 856 if (depth > path[0].p_maxdepth) { 857 kfree(path); 858 *orig_path = path = NULL; 859 } 860 } 861 if (!path) { 862 /* account possible depth increase */ 863 path = kcalloc(depth + 2, sizeof(struct ext4_ext_path), 864 gfp_flags); 865 if (unlikely(!path)) 866 return ERR_PTR(-ENOMEM); 867 path[0].p_maxdepth = depth + 1; 868 } 869 path[0].p_hdr = eh; 870 path[0].p_bh = NULL; 871 872 i = depth; 873 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) 874 ext4_cache_extents(inode, eh); 875 /* walk through the tree */ 876 while (i) { 877 ext_debug(inode, "depth %d: num %d, max %d\n", 878 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); 879 880 ext4_ext_binsearch_idx(inode, path + ppos, block); 881 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx); 882 path[ppos].p_depth = i; 883 path[ppos].p_ext = NULL; 884 885 bh = read_extent_tree_block(inode, path[ppos].p_block, --i, 886 flags); 887 if (IS_ERR(bh)) { 888 ret = PTR_ERR(bh); 889 goto err; 890 } 891 892 eh = ext_block_hdr(bh); 893 ppos++; 894 path[ppos].p_bh = bh; 895 path[ppos].p_hdr = eh; 896 } 897 898 path[ppos].p_depth = i; 899 path[ppos].p_ext = NULL; 900 path[ppos].p_idx = NULL; 901 902 /* find extent */ 903 ext4_ext_binsearch(inode, path + ppos, block); 904 /* if not an empty leaf */ 905 if (path[ppos].p_ext) 906 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext); 907 908 ext4_ext_show_path(inode, path); 909 910 return path; 911 912 err: 913 ext4_ext_drop_refs(path); 914 kfree(path); 915 if (orig_path) 916 *orig_path = NULL; 917 return ERR_PTR(ret); 918 } 919 920 /* 921 * ext4_ext_insert_index: 922 * insert new index [@logical;@ptr] into the block at @curp; 923 * check where to insert: before @curp or after @curp 924 */ 925 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, 926 struct ext4_ext_path *curp, 927 int logical, ext4_fsblk_t ptr) 928 { 929 struct ext4_extent_idx *ix; 930 int len, err; 931 932 err = ext4_ext_get_access(handle, inode, curp); 933 if (err) 934 return err; 935 936 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) { 937 EXT4_ERROR_INODE(inode, 938 "logical %d == ei_block %d!", 939 logical, le32_to_cpu(curp->p_idx->ei_block)); 940 return -EFSCORRUPTED; 941 } 942 943 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) 944 >= le16_to_cpu(curp->p_hdr->eh_max))) { 945 EXT4_ERROR_INODE(inode, 946 "eh_entries %d >= eh_max %d!", 947 le16_to_cpu(curp->p_hdr->eh_entries), 948 le16_to_cpu(curp->p_hdr->eh_max)); 949 return -EFSCORRUPTED; 950 } 951 952 if (logical > le32_to_cpu(curp->p_idx->ei_block)) { 953 /* insert after */ 954 ext_debug(inode, "insert new index %d after: %llu\n", 955 logical, ptr); 956 ix = curp->p_idx + 1; 957 } else { 958 /* insert before */ 959 ext_debug(inode, "insert new index %d before: %llu\n", 960 logical, ptr); 961 ix = curp->p_idx; 962 } 963 964 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1; 965 BUG_ON(len < 0); 966 if (len > 0) { 967 ext_debug(inode, "insert new index %d: " 968 "move %d indices from 0x%p to 0x%p\n", 969 logical, len, ix, ix + 1); 970 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx)); 971 } 972 973 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) { 974 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!"); 975 return -EFSCORRUPTED; 976 } 977 978 ix->ei_block = cpu_to_le32(logical); 979 ext4_idx_store_pblock(ix, ptr); 980 le16_add_cpu(&curp->p_hdr->eh_entries, 1); 981 982 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) { 983 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!"); 984 return -EFSCORRUPTED; 985 } 986 987 err = ext4_ext_dirty(handle, inode, curp); 988 ext4_std_error(inode->i_sb, err); 989 990 return err; 991 } 992 993 /* 994 * ext4_ext_split: 995 * inserts new subtree into the path, using free index entry 996 * at depth @at: 997 * - allocates all needed blocks (new leaf and all intermediate index blocks) 998 * - makes decision where to split 999 * - moves remaining extents and index entries (right to the split point) 1000 * into the newly allocated blocks 1001 * - initializes subtree 1002 */ 1003 static int ext4_ext_split(handle_t *handle, struct inode *inode, 1004 unsigned int flags, 1005 struct ext4_ext_path *path, 1006 struct ext4_extent *newext, int at) 1007 { 1008 struct buffer_head *bh = NULL; 1009 int depth = ext_depth(inode); 1010 struct ext4_extent_header *neh; 1011 struct ext4_extent_idx *fidx; 1012 int i = at, k, m, a; 1013 ext4_fsblk_t newblock, oldblock; 1014 __le32 border; 1015 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ 1016 gfp_t gfp_flags = GFP_NOFS; 1017 int err = 0; 1018 size_t ext_size = 0; 1019 1020 if (flags & EXT4_EX_NOFAIL) 1021 gfp_flags |= __GFP_NOFAIL; 1022 1023 /* make decision: where to split? */ 1024 /* FIXME: now decision is simplest: at current extent */ 1025 1026 /* if current leaf will be split, then we should use 1027 * border from split point */ 1028 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) { 1029 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!"); 1030 return -EFSCORRUPTED; 1031 } 1032 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { 1033 border = path[depth].p_ext[1].ee_block; 1034 ext_debug(inode, "leaf will be split." 1035 " next leaf starts at %d\n", 1036 le32_to_cpu(border)); 1037 } else { 1038 border = newext->ee_block; 1039 ext_debug(inode, "leaf will be added." 1040 " next leaf starts at %d\n", 1041 le32_to_cpu(border)); 1042 } 1043 1044 /* 1045 * If error occurs, then we break processing 1046 * and mark filesystem read-only. index won't 1047 * be inserted and tree will be in consistent 1048 * state. Next mount will repair buffers too. 1049 */ 1050 1051 /* 1052 * Get array to track all allocated blocks. 1053 * We need this to handle errors and free blocks 1054 * upon them. 1055 */ 1056 ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), gfp_flags); 1057 if (!ablocks) 1058 return -ENOMEM; 1059 1060 /* allocate all needed blocks */ 1061 ext_debug(inode, "allocate %d blocks for indexes/leaf\n", depth - at); 1062 for (a = 0; a < depth - at; a++) { 1063 newblock = ext4_ext_new_meta_block(handle, inode, path, 1064 newext, &err, flags); 1065 if (newblock == 0) 1066 goto cleanup; 1067 ablocks[a] = newblock; 1068 } 1069 1070 /* initialize new leaf */ 1071 newblock = ablocks[--a]; 1072 if (unlikely(newblock == 0)) { 1073 EXT4_ERROR_INODE(inode, "newblock == 0!"); 1074 err = -EFSCORRUPTED; 1075 goto cleanup; 1076 } 1077 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS); 1078 if (unlikely(!bh)) { 1079 err = -ENOMEM; 1080 goto cleanup; 1081 } 1082 lock_buffer(bh); 1083 1084 err = ext4_journal_get_create_access(handle, bh); 1085 if (err) 1086 goto cleanup; 1087 1088 neh = ext_block_hdr(bh); 1089 neh->eh_entries = 0; 1090 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); 1091 neh->eh_magic = EXT4_EXT_MAGIC; 1092 neh->eh_depth = 0; 1093 1094 /* move remainder of path[depth] to the new leaf */ 1095 if (unlikely(path[depth].p_hdr->eh_entries != 1096 path[depth].p_hdr->eh_max)) { 1097 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!", 1098 path[depth].p_hdr->eh_entries, 1099 path[depth].p_hdr->eh_max); 1100 err = -EFSCORRUPTED; 1101 goto cleanup; 1102 } 1103 /* start copy from next extent */ 1104 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++; 1105 ext4_ext_show_move(inode, path, newblock, depth); 1106 if (m) { 1107 struct ext4_extent *ex; 1108 ex = EXT_FIRST_EXTENT(neh); 1109 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m); 1110 le16_add_cpu(&neh->eh_entries, m); 1111 } 1112 1113 /* zero out unused area in the extent block */ 1114 ext_size = sizeof(struct ext4_extent_header) + 1115 sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries); 1116 memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); 1117 ext4_extent_block_csum_set(inode, neh); 1118 set_buffer_uptodate(bh); 1119 unlock_buffer(bh); 1120 1121 err = ext4_handle_dirty_metadata(handle, inode, bh); 1122 if (err) 1123 goto cleanup; 1124 brelse(bh); 1125 bh = NULL; 1126 1127 /* correct old leaf */ 1128 if (m) { 1129 err = ext4_ext_get_access(handle, inode, path + depth); 1130 if (err) 1131 goto cleanup; 1132 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m); 1133 err = ext4_ext_dirty(handle, inode, path + depth); 1134 if (err) 1135 goto cleanup; 1136 1137 } 1138 1139 /* create intermediate indexes */ 1140 k = depth - at - 1; 1141 if (unlikely(k < 0)) { 1142 EXT4_ERROR_INODE(inode, "k %d < 0!", k); 1143 err = -EFSCORRUPTED; 1144 goto cleanup; 1145 } 1146 if (k) 1147 ext_debug(inode, "create %d intermediate indices\n", k); 1148 /* insert new index into current index block */ 1149 /* current depth stored in i var */ 1150 i = depth - 1; 1151 while (k--) { 1152 oldblock = newblock; 1153 newblock = ablocks[--a]; 1154 bh = sb_getblk(inode->i_sb, newblock); 1155 if (unlikely(!bh)) { 1156 err = -ENOMEM; 1157 goto cleanup; 1158 } 1159 lock_buffer(bh); 1160 1161 err = ext4_journal_get_create_access(handle, bh); 1162 if (err) 1163 goto cleanup; 1164 1165 neh = ext_block_hdr(bh); 1166 neh->eh_entries = cpu_to_le16(1); 1167 neh->eh_magic = EXT4_EXT_MAGIC; 1168 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); 1169 neh->eh_depth = cpu_to_le16(depth - i); 1170 fidx = EXT_FIRST_INDEX(neh); 1171 fidx->ei_block = border; 1172 ext4_idx_store_pblock(fidx, oldblock); 1173 1174 ext_debug(inode, "int.index at %d (block %llu): %u -> %llu\n", 1175 i, newblock, le32_to_cpu(border), oldblock); 1176 1177 /* move remainder of path[i] to the new index block */ 1178 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) != 1179 EXT_LAST_INDEX(path[i].p_hdr))) { 1180 EXT4_ERROR_INODE(inode, 1181 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!", 1182 le32_to_cpu(path[i].p_ext->ee_block)); 1183 err = -EFSCORRUPTED; 1184 goto cleanup; 1185 } 1186 /* start copy indexes */ 1187 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++; 1188 ext_debug(inode, "cur 0x%p, last 0x%p\n", path[i].p_idx, 1189 EXT_MAX_INDEX(path[i].p_hdr)); 1190 ext4_ext_show_move(inode, path, newblock, i); 1191 if (m) { 1192 memmove(++fidx, path[i].p_idx, 1193 sizeof(struct ext4_extent_idx) * m); 1194 le16_add_cpu(&neh->eh_entries, m); 1195 } 1196 /* zero out unused area in the extent block */ 1197 ext_size = sizeof(struct ext4_extent_header) + 1198 (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries)); 1199 memset(bh->b_data + ext_size, 0, 1200 inode->i_sb->s_blocksize - ext_size); 1201 ext4_extent_block_csum_set(inode, neh); 1202 set_buffer_uptodate(bh); 1203 unlock_buffer(bh); 1204 1205 err = ext4_handle_dirty_metadata(handle, inode, bh); 1206 if (err) 1207 goto cleanup; 1208 brelse(bh); 1209 bh = NULL; 1210 1211 /* correct old index */ 1212 if (m) { 1213 err = ext4_ext_get_access(handle, inode, path + i); 1214 if (err) 1215 goto cleanup; 1216 le16_add_cpu(&path[i].p_hdr->eh_entries, -m); 1217 err = ext4_ext_dirty(handle, inode, path + i); 1218 if (err) 1219 goto cleanup; 1220 } 1221 1222 i--; 1223 } 1224 1225 /* insert new index */ 1226 err = ext4_ext_insert_index(handle, inode, path + at, 1227 le32_to_cpu(border), newblock); 1228 1229 cleanup: 1230 if (bh) { 1231 if (buffer_locked(bh)) 1232 unlock_buffer(bh); 1233 brelse(bh); 1234 } 1235 1236 if (err) { 1237 /* free all allocated blocks in error case */ 1238 for (i = 0; i < depth; i++) { 1239 if (!ablocks[i]) 1240 continue; 1241 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1, 1242 EXT4_FREE_BLOCKS_METADATA); 1243 } 1244 } 1245 kfree(ablocks); 1246 1247 return err; 1248 } 1249 1250 /* 1251 * ext4_ext_grow_indepth: 1252 * implements tree growing procedure: 1253 * - allocates new block 1254 * - moves top-level data (index block or leaf) into the new block 1255 * - initializes new top-level, creating index that points to the 1256 * just created block 1257 */ 1258 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, 1259 unsigned int flags) 1260 { 1261 struct ext4_extent_header *neh; 1262 struct buffer_head *bh; 1263 ext4_fsblk_t newblock, goal = 0; 1264 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; 1265 int err = 0; 1266 size_t ext_size = 0; 1267 1268 /* Try to prepend new index to old one */ 1269 if (ext_depth(inode)) 1270 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode))); 1271 if (goal > le32_to_cpu(es->s_first_data_block)) { 1272 flags |= EXT4_MB_HINT_TRY_GOAL; 1273 goal--; 1274 } else 1275 goal = ext4_inode_to_goal_block(inode); 1276 newblock = ext4_new_meta_blocks(handle, inode, goal, flags, 1277 NULL, &err); 1278 if (newblock == 0) 1279 return err; 1280 1281 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS); 1282 if (unlikely(!bh)) 1283 return -ENOMEM; 1284 lock_buffer(bh); 1285 1286 err = ext4_journal_get_create_access(handle, bh); 1287 if (err) { 1288 unlock_buffer(bh); 1289 goto out; 1290 } 1291 1292 ext_size = sizeof(EXT4_I(inode)->i_data); 1293 /* move top-level index/leaf into new block */ 1294 memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size); 1295 /* zero out unused area in the extent block */ 1296 memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); 1297 1298 /* set size of new block */ 1299 neh = ext_block_hdr(bh); 1300 /* old root could have indexes or leaves 1301 * so calculate e_max right way */ 1302 if (ext_depth(inode)) 1303 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); 1304 else 1305 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); 1306 neh->eh_magic = EXT4_EXT_MAGIC; 1307 ext4_extent_block_csum_set(inode, neh); 1308 set_buffer_uptodate(bh); 1309 unlock_buffer(bh); 1310 1311 err = ext4_handle_dirty_metadata(handle, inode, bh); 1312 if (err) 1313 goto out; 1314 1315 /* Update top-level index: num,max,pointer */ 1316 neh = ext_inode_hdr(inode); 1317 neh->eh_entries = cpu_to_le16(1); 1318 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock); 1319 if (neh->eh_depth == 0) { 1320 /* Root extent block becomes index block */ 1321 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); 1322 EXT_FIRST_INDEX(neh)->ei_block = 1323 EXT_FIRST_EXTENT(neh)->ee_block; 1324 } 1325 ext_debug(inode, "new root: num %d(%d), lblock %d, ptr %llu\n", 1326 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), 1327 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), 1328 ext4_idx_pblock(EXT_FIRST_INDEX(neh))); 1329 1330 le16_add_cpu(&neh->eh_depth, 1); 1331 err = ext4_mark_inode_dirty(handle, inode); 1332 out: 1333 brelse(bh); 1334 1335 return err; 1336 } 1337 1338 /* 1339 * ext4_ext_create_new_leaf: 1340 * finds empty index and adds new leaf. 1341 * if no free index is found, then it requests in-depth growing. 1342 */ 1343 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, 1344 unsigned int mb_flags, 1345 unsigned int gb_flags, 1346 struct ext4_ext_path **ppath, 1347 struct ext4_extent *newext) 1348 { 1349 struct ext4_ext_path *path = *ppath; 1350 struct ext4_ext_path *curp; 1351 int depth, i, err = 0; 1352 1353 repeat: 1354 i = depth = ext_depth(inode); 1355 1356 /* walk up to the tree and look for free index entry */ 1357 curp = path + depth; 1358 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { 1359 i--; 1360 curp--; 1361 } 1362 1363 /* we use already allocated block for index block, 1364 * so subsequent data blocks should be contiguous */ 1365 if (EXT_HAS_FREE_INDEX(curp)) { 1366 /* if we found index with free entry, then use that 1367 * entry: create all needed subtree and add new leaf */ 1368 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i); 1369 if (err) 1370 goto out; 1371 1372 /* refill path */ 1373 path = ext4_find_extent(inode, 1374 (ext4_lblk_t)le32_to_cpu(newext->ee_block), 1375 ppath, gb_flags); 1376 if (IS_ERR(path)) 1377 err = PTR_ERR(path); 1378 } else { 1379 /* tree is full, time to grow in depth */ 1380 err = ext4_ext_grow_indepth(handle, inode, mb_flags); 1381 if (err) 1382 goto out; 1383 1384 /* refill path */ 1385 path = ext4_find_extent(inode, 1386 (ext4_lblk_t)le32_to_cpu(newext->ee_block), 1387 ppath, gb_flags); 1388 if (IS_ERR(path)) { 1389 err = PTR_ERR(path); 1390 goto out; 1391 } 1392 1393 /* 1394 * only first (depth 0 -> 1) produces free space; 1395 * in all other cases we have to split the grown tree 1396 */ 1397 depth = ext_depth(inode); 1398 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { 1399 /* now we need to split */ 1400 goto repeat; 1401 } 1402 } 1403 1404 out: 1405 return err; 1406 } 1407 1408 /* 1409 * search the closest allocated block to the left for *logical 1410 * and returns it at @logical + it's physical address at @phys 1411 * if *logical is the smallest allocated block, the function 1412 * returns 0 at @phys 1413 * return value contains 0 (success) or error code 1414 */ 1415 static int ext4_ext_search_left(struct inode *inode, 1416 struct ext4_ext_path *path, 1417 ext4_lblk_t *logical, ext4_fsblk_t *phys) 1418 { 1419 struct ext4_extent_idx *ix; 1420 struct ext4_extent *ex; 1421 int depth, ee_len; 1422 1423 if (unlikely(path == NULL)) { 1424 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); 1425 return -EFSCORRUPTED; 1426 } 1427 depth = path->p_depth; 1428 *phys = 0; 1429 1430 if (depth == 0 && path->p_ext == NULL) 1431 return 0; 1432 1433 /* usually extent in the path covers blocks smaller 1434 * then *logical, but it can be that extent is the 1435 * first one in the file */ 1436 1437 ex = path[depth].p_ext; 1438 ee_len = ext4_ext_get_actual_len(ex); 1439 if (*logical < le32_to_cpu(ex->ee_block)) { 1440 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { 1441 EXT4_ERROR_INODE(inode, 1442 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!", 1443 *logical, le32_to_cpu(ex->ee_block)); 1444 return -EFSCORRUPTED; 1445 } 1446 while (--depth >= 0) { 1447 ix = path[depth].p_idx; 1448 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { 1449 EXT4_ERROR_INODE(inode, 1450 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!", 1451 ix != NULL ? le32_to_cpu(ix->ei_block) : 0, 1452 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ? 1453 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0, 1454 depth); 1455 return -EFSCORRUPTED; 1456 } 1457 } 1458 return 0; 1459 } 1460 1461 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { 1462 EXT4_ERROR_INODE(inode, 1463 "logical %d < ee_block %d + ee_len %d!", 1464 *logical, le32_to_cpu(ex->ee_block), ee_len); 1465 return -EFSCORRUPTED; 1466 } 1467 1468 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; 1469 *phys = ext4_ext_pblock(ex) + ee_len - 1; 1470 return 0; 1471 } 1472 1473 /* 1474 * search the closest allocated block to the right for *logical 1475 * and returns it at @logical + it's physical address at @phys 1476 * if *logical is the largest allocated block, the function 1477 * returns 0 at @phys 1478 * return value contains 0 (success) or error code 1479 */ 1480 static int ext4_ext_search_right(struct inode *inode, 1481 struct ext4_ext_path *path, 1482 ext4_lblk_t *logical, ext4_fsblk_t *phys, 1483 struct ext4_extent **ret_ex) 1484 { 1485 struct buffer_head *bh = NULL; 1486 struct ext4_extent_header *eh; 1487 struct ext4_extent_idx *ix; 1488 struct ext4_extent *ex; 1489 ext4_fsblk_t block; 1490 int depth; /* Note, NOT eh_depth; depth from top of tree */ 1491 int ee_len; 1492 1493 if (unlikely(path == NULL)) { 1494 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); 1495 return -EFSCORRUPTED; 1496 } 1497 depth = path->p_depth; 1498 *phys = 0; 1499 1500 if (depth == 0 && path->p_ext == NULL) 1501 return 0; 1502 1503 /* usually extent in the path covers blocks smaller 1504 * then *logical, but it can be that extent is the 1505 * first one in the file */ 1506 1507 ex = path[depth].p_ext; 1508 ee_len = ext4_ext_get_actual_len(ex); 1509 if (*logical < le32_to_cpu(ex->ee_block)) { 1510 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { 1511 EXT4_ERROR_INODE(inode, 1512 "first_extent(path[%d].p_hdr) != ex", 1513 depth); 1514 return -EFSCORRUPTED; 1515 } 1516 while (--depth >= 0) { 1517 ix = path[depth].p_idx; 1518 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { 1519 EXT4_ERROR_INODE(inode, 1520 "ix != EXT_FIRST_INDEX *logical %d!", 1521 *logical); 1522 return -EFSCORRUPTED; 1523 } 1524 } 1525 goto found_extent; 1526 } 1527 1528 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { 1529 EXT4_ERROR_INODE(inode, 1530 "logical %d < ee_block %d + ee_len %d!", 1531 *logical, le32_to_cpu(ex->ee_block), ee_len); 1532 return -EFSCORRUPTED; 1533 } 1534 1535 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { 1536 /* next allocated block in this leaf */ 1537 ex++; 1538 goto found_extent; 1539 } 1540 1541 /* go up and search for index to the right */ 1542 while (--depth >= 0) { 1543 ix = path[depth].p_idx; 1544 if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) 1545 goto got_index; 1546 } 1547 1548 /* we've gone up to the root and found no index to the right */ 1549 return 0; 1550 1551 got_index: 1552 /* we've found index to the right, let's 1553 * follow it and find the closest allocated 1554 * block to the right */ 1555 ix++; 1556 block = ext4_idx_pblock(ix); 1557 while (++depth < path->p_depth) { 1558 /* subtract from p_depth to get proper eh_depth */ 1559 bh = read_extent_tree_block(inode, block, 1560 path->p_depth - depth, 0); 1561 if (IS_ERR(bh)) 1562 return PTR_ERR(bh); 1563 eh = ext_block_hdr(bh); 1564 ix = EXT_FIRST_INDEX(eh); 1565 block = ext4_idx_pblock(ix); 1566 put_bh(bh); 1567 } 1568 1569 bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0); 1570 if (IS_ERR(bh)) 1571 return PTR_ERR(bh); 1572 eh = ext_block_hdr(bh); 1573 ex = EXT_FIRST_EXTENT(eh); 1574 found_extent: 1575 *logical = le32_to_cpu(ex->ee_block); 1576 *phys = ext4_ext_pblock(ex); 1577 *ret_ex = ex; 1578 if (bh) 1579 put_bh(bh); 1580 return 0; 1581 } 1582 1583 /* 1584 * ext4_ext_next_allocated_block: 1585 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS. 1586 * NOTE: it considers block number from index entry as 1587 * allocated block. Thus, index entries have to be consistent 1588 * with leaves. 1589 */ 1590 ext4_lblk_t 1591 ext4_ext_next_allocated_block(struct ext4_ext_path *path) 1592 { 1593 int depth; 1594 1595 BUG_ON(path == NULL); 1596 depth = path->p_depth; 1597 1598 if (depth == 0 && path->p_ext == NULL) 1599 return EXT_MAX_BLOCKS; 1600 1601 while (depth >= 0) { 1602 struct ext4_ext_path *p = &path[depth]; 1603 1604 if (depth == path->p_depth) { 1605 /* leaf */ 1606 if (p->p_ext && p->p_ext != EXT_LAST_EXTENT(p->p_hdr)) 1607 return le32_to_cpu(p->p_ext[1].ee_block); 1608 } else { 1609 /* index */ 1610 if (p->p_idx != EXT_LAST_INDEX(p->p_hdr)) 1611 return le32_to_cpu(p->p_idx[1].ei_block); 1612 } 1613 depth--; 1614 } 1615 1616 return EXT_MAX_BLOCKS; 1617 } 1618 1619 /* 1620 * ext4_ext_next_leaf_block: 1621 * returns first allocated block from next leaf or EXT_MAX_BLOCKS 1622 */ 1623 static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path) 1624 { 1625 int depth; 1626 1627 BUG_ON(path == NULL); 1628 depth = path->p_depth; 1629 1630 /* zero-tree has no leaf blocks at all */ 1631 if (depth == 0) 1632 return EXT_MAX_BLOCKS; 1633 1634 /* go to index block */ 1635 depth--; 1636 1637 while (depth >= 0) { 1638 if (path[depth].p_idx != 1639 EXT_LAST_INDEX(path[depth].p_hdr)) 1640 return (ext4_lblk_t) 1641 le32_to_cpu(path[depth].p_idx[1].ei_block); 1642 depth--; 1643 } 1644 1645 return EXT_MAX_BLOCKS; 1646 } 1647 1648 /* 1649 * ext4_ext_correct_indexes: 1650 * if leaf gets modified and modified extent is first in the leaf, 1651 * then we have to correct all indexes above. 1652 * TODO: do we need to correct tree in all cases? 1653 */ 1654 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, 1655 struct ext4_ext_path *path) 1656 { 1657 struct ext4_extent_header *eh; 1658 int depth = ext_depth(inode); 1659 struct ext4_extent *ex; 1660 __le32 border; 1661 int k, err = 0; 1662 1663 eh = path[depth].p_hdr; 1664 ex = path[depth].p_ext; 1665 1666 if (unlikely(ex == NULL || eh == NULL)) { 1667 EXT4_ERROR_INODE(inode, 1668 "ex %p == NULL or eh %p == NULL", ex, eh); 1669 return -EFSCORRUPTED; 1670 } 1671 1672 if (depth == 0) { 1673 /* there is no tree at all */ 1674 return 0; 1675 } 1676 1677 if (ex != EXT_FIRST_EXTENT(eh)) { 1678 /* we correct tree if first leaf got modified only */ 1679 return 0; 1680 } 1681 1682 /* 1683 * TODO: we need correction if border is smaller than current one 1684 */ 1685 k = depth - 1; 1686 border = path[depth].p_ext->ee_block; 1687 err = ext4_ext_get_access(handle, inode, path + k); 1688 if (err) 1689 return err; 1690 path[k].p_idx->ei_block = border; 1691 err = ext4_ext_dirty(handle, inode, path + k); 1692 if (err) 1693 return err; 1694 1695 while (k--) { 1696 /* change all left-side indexes */ 1697 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) 1698 break; 1699 err = ext4_ext_get_access(handle, inode, path + k); 1700 if (err) 1701 break; 1702 path[k].p_idx->ei_block = border; 1703 err = ext4_ext_dirty(handle, inode, path + k); 1704 if (err) 1705 break; 1706 } 1707 1708 return err; 1709 } 1710 1711 static int ext4_can_extents_be_merged(struct inode *inode, 1712 struct ext4_extent *ex1, 1713 struct ext4_extent *ex2) 1714 { 1715 unsigned short ext1_ee_len, ext2_ee_len; 1716 1717 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2)) 1718 return 0; 1719 1720 ext1_ee_len = ext4_ext_get_actual_len(ex1); 1721 ext2_ee_len = ext4_ext_get_actual_len(ex2); 1722 1723 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != 1724 le32_to_cpu(ex2->ee_block)) 1725 return 0; 1726 1727 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN) 1728 return 0; 1729 1730 if (ext4_ext_is_unwritten(ex1) && 1731 ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN) 1732 return 0; 1733 #ifdef AGGRESSIVE_TEST 1734 if (ext1_ee_len >= 4) 1735 return 0; 1736 #endif 1737 1738 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2)) 1739 return 1; 1740 return 0; 1741 } 1742 1743 /* 1744 * This function tries to merge the "ex" extent to the next extent in the tree. 1745 * It always tries to merge towards right. If you want to merge towards 1746 * left, pass "ex - 1" as argument instead of "ex". 1747 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns 1748 * 1 if they got merged. 1749 */ 1750 static int ext4_ext_try_to_merge_right(struct inode *inode, 1751 struct ext4_ext_path *path, 1752 struct ext4_extent *ex) 1753 { 1754 struct ext4_extent_header *eh; 1755 unsigned int depth, len; 1756 int merge_done = 0, unwritten; 1757 1758 depth = ext_depth(inode); 1759 BUG_ON(path[depth].p_hdr == NULL); 1760 eh = path[depth].p_hdr; 1761 1762 while (ex < EXT_LAST_EXTENT(eh)) { 1763 if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) 1764 break; 1765 /* merge with next extent! */ 1766 unwritten = ext4_ext_is_unwritten(ex); 1767 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 1768 + ext4_ext_get_actual_len(ex + 1)); 1769 if (unwritten) 1770 ext4_ext_mark_unwritten(ex); 1771 1772 if (ex + 1 < EXT_LAST_EXTENT(eh)) { 1773 len = (EXT_LAST_EXTENT(eh) - ex - 1) 1774 * sizeof(struct ext4_extent); 1775 memmove(ex + 1, ex + 2, len); 1776 } 1777 le16_add_cpu(&eh->eh_entries, -1); 1778 merge_done = 1; 1779 WARN_ON(eh->eh_entries == 0); 1780 if (!eh->eh_entries) 1781 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!"); 1782 } 1783 1784 return merge_done; 1785 } 1786 1787 /* 1788 * This function does a very simple check to see if we can collapse 1789 * an extent tree with a single extent tree leaf block into the inode. 1790 */ 1791 static void ext4_ext_try_to_merge_up(handle_t *handle, 1792 struct inode *inode, 1793 struct ext4_ext_path *path) 1794 { 1795 size_t s; 1796 unsigned max_root = ext4_ext_space_root(inode, 0); 1797 ext4_fsblk_t blk; 1798 1799 if ((path[0].p_depth != 1) || 1800 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) || 1801 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root)) 1802 return; 1803 1804 /* 1805 * We need to modify the block allocation bitmap and the block 1806 * group descriptor to release the extent tree block. If we 1807 * can't get the journal credits, give up. 1808 */ 1809 if (ext4_journal_extend(handle, 2, 1810 ext4_free_metadata_revoke_credits(inode->i_sb, 1))) 1811 return; 1812 1813 /* 1814 * Copy the extent data up to the inode 1815 */ 1816 blk = ext4_idx_pblock(path[0].p_idx); 1817 s = le16_to_cpu(path[1].p_hdr->eh_entries) * 1818 sizeof(struct ext4_extent_idx); 1819 s += sizeof(struct ext4_extent_header); 1820 1821 path[1].p_maxdepth = path[0].p_maxdepth; 1822 memcpy(path[0].p_hdr, path[1].p_hdr, s); 1823 path[0].p_depth = 0; 1824 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) + 1825 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr)); 1826 path[0].p_hdr->eh_max = cpu_to_le16(max_root); 1827 1828 brelse(path[1].p_bh); 1829 ext4_free_blocks(handle, inode, NULL, blk, 1, 1830 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); 1831 } 1832 1833 /* 1834 * This function tries to merge the @ex extent to neighbours in the tree, then 1835 * tries to collapse the extent tree into the inode. 1836 */ 1837 static void ext4_ext_try_to_merge(handle_t *handle, 1838 struct inode *inode, 1839 struct ext4_ext_path *path, 1840 struct ext4_extent *ex) 1841 { 1842 struct ext4_extent_header *eh; 1843 unsigned int depth; 1844 int merge_done = 0; 1845 1846 depth = ext_depth(inode); 1847 BUG_ON(path[depth].p_hdr == NULL); 1848 eh = path[depth].p_hdr; 1849 1850 if (ex > EXT_FIRST_EXTENT(eh)) 1851 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1); 1852 1853 if (!merge_done) 1854 (void) ext4_ext_try_to_merge_right(inode, path, ex); 1855 1856 ext4_ext_try_to_merge_up(handle, inode, path); 1857 } 1858 1859 /* 1860 * check if a portion of the "newext" extent overlaps with an 1861 * existing extent. 1862 * 1863 * If there is an overlap discovered, it updates the length of the newext 1864 * such that there will be no overlap, and then returns 1. 1865 * If there is no overlap found, it returns 0. 1866 */ 1867 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi, 1868 struct inode *inode, 1869 struct ext4_extent *newext, 1870 struct ext4_ext_path *path) 1871 { 1872 ext4_lblk_t b1, b2; 1873 unsigned int depth, len1; 1874 unsigned int ret = 0; 1875 1876 b1 = le32_to_cpu(newext->ee_block); 1877 len1 = ext4_ext_get_actual_len(newext); 1878 depth = ext_depth(inode); 1879 if (!path[depth].p_ext) 1880 goto out; 1881 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block)); 1882 1883 /* 1884 * get the next allocated block if the extent in the path 1885 * is before the requested block(s) 1886 */ 1887 if (b2 < b1) { 1888 b2 = ext4_ext_next_allocated_block(path); 1889 if (b2 == EXT_MAX_BLOCKS) 1890 goto out; 1891 b2 = EXT4_LBLK_CMASK(sbi, b2); 1892 } 1893 1894 /* check for wrap through zero on extent logical start block*/ 1895 if (b1 + len1 < b1) { 1896 len1 = EXT_MAX_BLOCKS - b1; 1897 newext->ee_len = cpu_to_le16(len1); 1898 ret = 1; 1899 } 1900 1901 /* check for overlap */ 1902 if (b1 + len1 > b2) { 1903 newext->ee_len = cpu_to_le16(b2 - b1); 1904 ret = 1; 1905 } 1906 out: 1907 return ret; 1908 } 1909 1910 /* 1911 * ext4_ext_insert_extent: 1912 * tries to merge requested extent into the existing extent or 1913 * inserts requested extent as new one into the tree, 1914 * creating new leaf in the no-space case. 1915 */ 1916 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, 1917 struct ext4_ext_path **ppath, 1918 struct ext4_extent *newext, int gb_flags) 1919 { 1920 struct ext4_ext_path *path = *ppath; 1921 struct ext4_extent_header *eh; 1922 struct ext4_extent *ex, *fex; 1923 struct ext4_extent *nearex; /* nearest extent */ 1924 struct ext4_ext_path *npath = NULL; 1925 int depth, len, err; 1926 ext4_lblk_t next; 1927 int mb_flags = 0, unwritten; 1928 1929 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) 1930 mb_flags |= EXT4_MB_DELALLOC_RESERVED; 1931 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) { 1932 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0"); 1933 return -EFSCORRUPTED; 1934 } 1935 depth = ext_depth(inode); 1936 ex = path[depth].p_ext; 1937 eh = path[depth].p_hdr; 1938 if (unlikely(path[depth].p_hdr == NULL)) { 1939 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); 1940 return -EFSCORRUPTED; 1941 } 1942 1943 /* try to insert block into found extent and return */ 1944 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) { 1945 1946 /* 1947 * Try to see whether we should rather test the extent on 1948 * right from ex, or from the left of ex. This is because 1949 * ext4_find_extent() can return either extent on the 1950 * left, or on the right from the searched position. This 1951 * will make merging more effective. 1952 */ 1953 if (ex < EXT_LAST_EXTENT(eh) && 1954 (le32_to_cpu(ex->ee_block) + 1955 ext4_ext_get_actual_len(ex) < 1956 le32_to_cpu(newext->ee_block))) { 1957 ex += 1; 1958 goto prepend; 1959 } else if ((ex > EXT_FIRST_EXTENT(eh)) && 1960 (le32_to_cpu(newext->ee_block) + 1961 ext4_ext_get_actual_len(newext) < 1962 le32_to_cpu(ex->ee_block))) 1963 ex -= 1; 1964 1965 /* Try to append newex to the ex */ 1966 if (ext4_can_extents_be_merged(inode, ex, newext)) { 1967 ext_debug(inode, "append [%d]%d block to %u:[%d]%d" 1968 "(from %llu)\n", 1969 ext4_ext_is_unwritten(newext), 1970 ext4_ext_get_actual_len(newext), 1971 le32_to_cpu(ex->ee_block), 1972 ext4_ext_is_unwritten(ex), 1973 ext4_ext_get_actual_len(ex), 1974 ext4_ext_pblock(ex)); 1975 err = ext4_ext_get_access(handle, inode, 1976 path + depth); 1977 if (err) 1978 return err; 1979 unwritten = ext4_ext_is_unwritten(ex); 1980 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 1981 + ext4_ext_get_actual_len(newext)); 1982 if (unwritten) 1983 ext4_ext_mark_unwritten(ex); 1984 eh = path[depth].p_hdr; 1985 nearex = ex; 1986 goto merge; 1987 } 1988 1989 prepend: 1990 /* Try to prepend newex to the ex */ 1991 if (ext4_can_extents_be_merged(inode, newext, ex)) { 1992 ext_debug(inode, "prepend %u[%d]%d block to %u:[%d]%d" 1993 "(from %llu)\n", 1994 le32_to_cpu(newext->ee_block), 1995 ext4_ext_is_unwritten(newext), 1996 ext4_ext_get_actual_len(newext), 1997 le32_to_cpu(ex->ee_block), 1998 ext4_ext_is_unwritten(ex), 1999 ext4_ext_get_actual_len(ex), 2000 ext4_ext_pblock(ex)); 2001 err = ext4_ext_get_access(handle, inode, 2002 path + depth); 2003 if (err) 2004 return err; 2005 2006 unwritten = ext4_ext_is_unwritten(ex); 2007 ex->ee_block = newext->ee_block; 2008 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext)); 2009 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 2010 + ext4_ext_get_actual_len(newext)); 2011 if (unwritten) 2012 ext4_ext_mark_unwritten(ex); 2013 eh = path[depth].p_hdr; 2014 nearex = ex; 2015 goto merge; 2016 } 2017 } 2018 2019 depth = ext_depth(inode); 2020 eh = path[depth].p_hdr; 2021 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) 2022 goto has_space; 2023 2024 /* probably next leaf has space for us? */ 2025 fex = EXT_LAST_EXTENT(eh); 2026 next = EXT_MAX_BLOCKS; 2027 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)) 2028 next = ext4_ext_next_leaf_block(path); 2029 if (next != EXT_MAX_BLOCKS) { 2030 ext_debug(inode, "next leaf block - %u\n", next); 2031 BUG_ON(npath != NULL); 2032 npath = ext4_find_extent(inode, next, NULL, gb_flags); 2033 if (IS_ERR(npath)) 2034 return PTR_ERR(npath); 2035 BUG_ON(npath->p_depth != path->p_depth); 2036 eh = npath[depth].p_hdr; 2037 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { 2038 ext_debug(inode, "next leaf isn't full(%d)\n", 2039 le16_to_cpu(eh->eh_entries)); 2040 path = npath; 2041 goto has_space; 2042 } 2043 ext_debug(inode, "next leaf has no free space(%d,%d)\n", 2044 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); 2045 } 2046 2047 /* 2048 * There is no free space in the found leaf. 2049 * We're gonna add a new leaf in the tree. 2050 */ 2051 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) 2052 mb_flags |= EXT4_MB_USE_RESERVED; 2053 err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags, 2054 ppath, newext); 2055 if (err) 2056 goto cleanup; 2057 depth = ext_depth(inode); 2058 eh = path[depth].p_hdr; 2059 2060 has_space: 2061 nearex = path[depth].p_ext; 2062 2063 err = ext4_ext_get_access(handle, inode, path + depth); 2064 if (err) 2065 goto cleanup; 2066 2067 if (!nearex) { 2068 /* there is no extent in this leaf, create first one */ 2069 ext_debug(inode, "first extent in the leaf: %u:%llu:[%d]%d\n", 2070 le32_to_cpu(newext->ee_block), 2071 ext4_ext_pblock(newext), 2072 ext4_ext_is_unwritten(newext), 2073 ext4_ext_get_actual_len(newext)); 2074 nearex = EXT_FIRST_EXTENT(eh); 2075 } else { 2076 if (le32_to_cpu(newext->ee_block) 2077 > le32_to_cpu(nearex->ee_block)) { 2078 /* Insert after */ 2079 ext_debug(inode, "insert %u:%llu:[%d]%d before: " 2080 "nearest %p\n", 2081 le32_to_cpu(newext->ee_block), 2082 ext4_ext_pblock(newext), 2083 ext4_ext_is_unwritten(newext), 2084 ext4_ext_get_actual_len(newext), 2085 nearex); 2086 nearex++; 2087 } else { 2088 /* Insert before */ 2089 BUG_ON(newext->ee_block == nearex->ee_block); 2090 ext_debug(inode, "insert %u:%llu:[%d]%d after: " 2091 "nearest %p\n", 2092 le32_to_cpu(newext->ee_block), 2093 ext4_ext_pblock(newext), 2094 ext4_ext_is_unwritten(newext), 2095 ext4_ext_get_actual_len(newext), 2096 nearex); 2097 } 2098 len = EXT_LAST_EXTENT(eh) - nearex + 1; 2099 if (len > 0) { 2100 ext_debug(inode, "insert %u:%llu:[%d]%d: " 2101 "move %d extents from 0x%p to 0x%p\n", 2102 le32_to_cpu(newext->ee_block), 2103 ext4_ext_pblock(newext), 2104 ext4_ext_is_unwritten(newext), 2105 ext4_ext_get_actual_len(newext), 2106 len, nearex, nearex + 1); 2107 memmove(nearex + 1, nearex, 2108 len * sizeof(struct ext4_extent)); 2109 } 2110 } 2111 2112 le16_add_cpu(&eh->eh_entries, 1); 2113 path[depth].p_ext = nearex; 2114 nearex->ee_block = newext->ee_block; 2115 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext)); 2116 nearex->ee_len = newext->ee_len; 2117 2118 merge: 2119 /* try to merge extents */ 2120 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) 2121 ext4_ext_try_to_merge(handle, inode, path, nearex); 2122 2123 2124 /* time to correct all indexes above */ 2125 err = ext4_ext_correct_indexes(handle, inode, path); 2126 if (err) 2127 goto cleanup; 2128 2129 err = ext4_ext_dirty(handle, inode, path + path->p_depth); 2130 2131 cleanup: 2132 ext4_ext_drop_refs(npath); 2133 kfree(npath); 2134 return err; 2135 } 2136 2137 static int ext4_fill_es_cache_info(struct inode *inode, 2138 ext4_lblk_t block, ext4_lblk_t num, 2139 struct fiemap_extent_info *fieinfo) 2140 { 2141 ext4_lblk_t next, end = block + num - 1; 2142 struct extent_status es; 2143 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits; 2144 unsigned int flags; 2145 int err; 2146 2147 while (block <= end) { 2148 next = 0; 2149 flags = 0; 2150 if (!ext4_es_lookup_extent(inode, block, &next, &es)) 2151 break; 2152 if (ext4_es_is_unwritten(&es)) 2153 flags |= FIEMAP_EXTENT_UNWRITTEN; 2154 if (ext4_es_is_delayed(&es)) 2155 flags |= (FIEMAP_EXTENT_DELALLOC | 2156 FIEMAP_EXTENT_UNKNOWN); 2157 if (ext4_es_is_hole(&es)) 2158 flags |= EXT4_FIEMAP_EXTENT_HOLE; 2159 if (next == 0) 2160 flags |= FIEMAP_EXTENT_LAST; 2161 if (flags & (FIEMAP_EXTENT_DELALLOC| 2162 EXT4_FIEMAP_EXTENT_HOLE)) 2163 es.es_pblk = 0; 2164 else 2165 es.es_pblk = ext4_es_pblock(&es); 2166 err = fiemap_fill_next_extent(fieinfo, 2167 (__u64)es.es_lblk << blksize_bits, 2168 (__u64)es.es_pblk << blksize_bits, 2169 (__u64)es.es_len << blksize_bits, 2170 flags); 2171 if (next == 0) 2172 break; 2173 block = next; 2174 if (err < 0) 2175 return err; 2176 if (err == 1) 2177 return 0; 2178 } 2179 return 0; 2180 } 2181 2182 2183 /* 2184 * ext4_ext_determine_hole - determine hole around given block 2185 * @inode: inode we lookup in 2186 * @path: path in extent tree to @lblk 2187 * @lblk: pointer to logical block around which we want to determine hole 2188 * 2189 * Determine hole length (and start if easily possible) around given logical 2190 * block. We don't try too hard to find the beginning of the hole but @path 2191 * actually points to extent before @lblk, we provide it. 2192 * 2193 * The function returns the length of a hole starting at @lblk. We update @lblk 2194 * to the beginning of the hole if we managed to find it. 2195 */ 2196 static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode, 2197 struct ext4_ext_path *path, 2198 ext4_lblk_t *lblk) 2199 { 2200 int depth = ext_depth(inode); 2201 struct ext4_extent *ex; 2202 ext4_lblk_t len; 2203 2204 ex = path[depth].p_ext; 2205 if (ex == NULL) { 2206 /* there is no extent yet, so gap is [0;-] */ 2207 *lblk = 0; 2208 len = EXT_MAX_BLOCKS; 2209 } else if (*lblk < le32_to_cpu(ex->ee_block)) { 2210 len = le32_to_cpu(ex->ee_block) - *lblk; 2211 } else if (*lblk >= le32_to_cpu(ex->ee_block) 2212 + ext4_ext_get_actual_len(ex)) { 2213 ext4_lblk_t next; 2214 2215 *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); 2216 next = ext4_ext_next_allocated_block(path); 2217 BUG_ON(next == *lblk); 2218 len = next - *lblk; 2219 } else { 2220 BUG(); 2221 } 2222 return len; 2223 } 2224 2225 /* 2226 * ext4_ext_put_gap_in_cache: 2227 * calculate boundaries of the gap that the requested block fits into 2228 * and cache this gap 2229 */ 2230 static void 2231 ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start, 2232 ext4_lblk_t hole_len) 2233 { 2234 struct extent_status es; 2235 2236 ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start, 2237 hole_start + hole_len - 1, &es); 2238 if (es.es_len) { 2239 /* There's delayed extent containing lblock? */ 2240 if (es.es_lblk <= hole_start) 2241 return; 2242 hole_len = min(es.es_lblk - hole_start, hole_len); 2243 } 2244 ext_debug(inode, " -> %u:%u\n", hole_start, hole_len); 2245 ext4_es_insert_extent(inode, hole_start, hole_len, ~0, 2246 EXTENT_STATUS_HOLE); 2247 } 2248 2249 /* 2250 * ext4_ext_rm_idx: 2251 * removes index from the index block. 2252 */ 2253 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, 2254 struct ext4_ext_path *path, int depth) 2255 { 2256 int err; 2257 ext4_fsblk_t leaf; 2258 2259 /* free index block */ 2260 depth--; 2261 path = path + depth; 2262 leaf = ext4_idx_pblock(path->p_idx); 2263 if (unlikely(path->p_hdr->eh_entries == 0)) { 2264 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0"); 2265 return -EFSCORRUPTED; 2266 } 2267 err = ext4_ext_get_access(handle, inode, path); 2268 if (err) 2269 return err; 2270 2271 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) { 2272 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx; 2273 len *= sizeof(struct ext4_extent_idx); 2274 memmove(path->p_idx, path->p_idx + 1, len); 2275 } 2276 2277 le16_add_cpu(&path->p_hdr->eh_entries, -1); 2278 err = ext4_ext_dirty(handle, inode, path); 2279 if (err) 2280 return err; 2281 ext_debug(inode, "index is empty, remove it, free block %llu\n", leaf); 2282 trace_ext4_ext_rm_idx(inode, leaf); 2283 2284 ext4_free_blocks(handle, inode, NULL, leaf, 1, 2285 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); 2286 2287 while (--depth >= 0) { 2288 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr)) 2289 break; 2290 path--; 2291 err = ext4_ext_get_access(handle, inode, path); 2292 if (err) 2293 break; 2294 path->p_idx->ei_block = (path+1)->p_idx->ei_block; 2295 err = ext4_ext_dirty(handle, inode, path); 2296 if (err) 2297 break; 2298 } 2299 return err; 2300 } 2301 2302 /* 2303 * ext4_ext_calc_credits_for_single_extent: 2304 * This routine returns max. credits that needed to insert an extent 2305 * to the extent tree. 2306 * When pass the actual path, the caller should calculate credits 2307 * under i_data_sem. 2308 */ 2309 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks, 2310 struct ext4_ext_path *path) 2311 { 2312 if (path) { 2313 int depth = ext_depth(inode); 2314 int ret = 0; 2315 2316 /* probably there is space in leaf? */ 2317 if (le16_to_cpu(path[depth].p_hdr->eh_entries) 2318 < le16_to_cpu(path[depth].p_hdr->eh_max)) { 2319 2320 /* 2321 * There are some space in the leaf tree, no 2322 * need to account for leaf block credit 2323 * 2324 * bitmaps and block group descriptor blocks 2325 * and other metadata blocks still need to be 2326 * accounted. 2327 */ 2328 /* 1 bitmap, 1 block group descriptor */ 2329 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb); 2330 return ret; 2331 } 2332 } 2333 2334 return ext4_chunk_trans_blocks(inode, nrblocks); 2335 } 2336 2337 /* 2338 * How many index/leaf blocks need to change/allocate to add @extents extents? 2339 * 2340 * If we add a single extent, then in the worse case, each tree level 2341 * index/leaf need to be changed in case of the tree split. 2342 * 2343 * If more extents are inserted, they could cause the whole tree split more 2344 * than once, but this is really rare. 2345 */ 2346 int ext4_ext_index_trans_blocks(struct inode *inode, int extents) 2347 { 2348 int index; 2349 int depth; 2350 2351 /* If we are converting the inline data, only one is needed here. */ 2352 if (ext4_has_inline_data(inode)) 2353 return 1; 2354 2355 depth = ext_depth(inode); 2356 2357 if (extents <= 1) 2358 index = depth * 2; 2359 else 2360 index = depth * 3; 2361 2362 return index; 2363 } 2364 2365 static inline int get_default_free_blocks_flags(struct inode *inode) 2366 { 2367 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) || 2368 ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE)) 2369 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET; 2370 else if (ext4_should_journal_data(inode)) 2371 return EXT4_FREE_BLOCKS_FORGET; 2372 return 0; 2373 } 2374 2375 /* 2376 * ext4_rereserve_cluster - increment the reserved cluster count when 2377 * freeing a cluster with a pending reservation 2378 * 2379 * @inode - file containing the cluster 2380 * @lblk - logical block in cluster to be reserved 2381 * 2382 * Increments the reserved cluster count and adjusts quota in a bigalloc 2383 * file system when freeing a partial cluster containing at least one 2384 * delayed and unwritten block. A partial cluster meeting that 2385 * requirement will have a pending reservation. If so, the 2386 * RERESERVE_CLUSTER flag is used when calling ext4_free_blocks() to 2387 * defer reserved and allocated space accounting to a subsequent call 2388 * to this function. 2389 */ 2390 static void ext4_rereserve_cluster(struct inode *inode, ext4_lblk_t lblk) 2391 { 2392 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2393 struct ext4_inode_info *ei = EXT4_I(inode); 2394 2395 dquot_reclaim_block(inode, EXT4_C2B(sbi, 1)); 2396 2397 spin_lock(&ei->i_block_reservation_lock); 2398 ei->i_reserved_data_blocks++; 2399 percpu_counter_add(&sbi->s_dirtyclusters_counter, 1); 2400 spin_unlock(&ei->i_block_reservation_lock); 2401 2402 percpu_counter_add(&sbi->s_freeclusters_counter, 1); 2403 ext4_remove_pending(inode, lblk); 2404 } 2405 2406 static int ext4_remove_blocks(handle_t *handle, struct inode *inode, 2407 struct ext4_extent *ex, 2408 struct partial_cluster *partial, 2409 ext4_lblk_t from, ext4_lblk_t to) 2410 { 2411 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2412 unsigned short ee_len = ext4_ext_get_actual_len(ex); 2413 ext4_fsblk_t last_pblk, pblk; 2414 ext4_lblk_t num; 2415 int flags; 2416 2417 /* only extent tail removal is allowed */ 2418 if (from < le32_to_cpu(ex->ee_block) || 2419 to != le32_to_cpu(ex->ee_block) + ee_len - 1) { 2420 ext4_error(sbi->s_sb, 2421 "strange request: removal(2) %u-%u from %u:%u", 2422 from, to, le32_to_cpu(ex->ee_block), ee_len); 2423 return 0; 2424 } 2425 2426 #ifdef EXTENTS_STATS 2427 spin_lock(&sbi->s_ext_stats_lock); 2428 sbi->s_ext_blocks += ee_len; 2429 sbi->s_ext_extents++; 2430 if (ee_len < sbi->s_ext_min) 2431 sbi->s_ext_min = ee_len; 2432 if (ee_len > sbi->s_ext_max) 2433 sbi->s_ext_max = ee_len; 2434 if (ext_depth(inode) > sbi->s_depth_max) 2435 sbi->s_depth_max = ext_depth(inode); 2436 spin_unlock(&sbi->s_ext_stats_lock); 2437 #endif 2438 2439 trace_ext4_remove_blocks(inode, ex, from, to, partial); 2440 2441 /* 2442 * if we have a partial cluster, and it's different from the 2443 * cluster of the last block in the extent, we free it 2444 */ 2445 last_pblk = ext4_ext_pblock(ex) + ee_len - 1; 2446 2447 if (partial->state != initial && 2448 partial->pclu != EXT4_B2C(sbi, last_pblk)) { 2449 if (partial->state == tofree) { 2450 flags = get_default_free_blocks_flags(inode); 2451 if (ext4_is_pending(inode, partial->lblk)) 2452 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; 2453 ext4_free_blocks(handle, inode, NULL, 2454 EXT4_C2B(sbi, partial->pclu), 2455 sbi->s_cluster_ratio, flags); 2456 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) 2457 ext4_rereserve_cluster(inode, partial->lblk); 2458 } 2459 partial->state = initial; 2460 } 2461 2462 num = le32_to_cpu(ex->ee_block) + ee_len - from; 2463 pblk = ext4_ext_pblock(ex) + ee_len - num; 2464 2465 /* 2466 * We free the partial cluster at the end of the extent (if any), 2467 * unless the cluster is used by another extent (partial_cluster 2468 * state is nofree). If a partial cluster exists here, it must be 2469 * shared with the last block in the extent. 2470 */ 2471 flags = get_default_free_blocks_flags(inode); 2472 2473 /* partial, left end cluster aligned, right end unaligned */ 2474 if ((EXT4_LBLK_COFF(sbi, to) != sbi->s_cluster_ratio - 1) && 2475 (EXT4_LBLK_CMASK(sbi, to) >= from) && 2476 (partial->state != nofree)) { 2477 if (ext4_is_pending(inode, to)) 2478 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; 2479 ext4_free_blocks(handle, inode, NULL, 2480 EXT4_PBLK_CMASK(sbi, last_pblk), 2481 sbi->s_cluster_ratio, flags); 2482 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) 2483 ext4_rereserve_cluster(inode, to); 2484 partial->state = initial; 2485 flags = get_default_free_blocks_flags(inode); 2486 } 2487 2488 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER; 2489 2490 /* 2491 * For bigalloc file systems, we never free a partial cluster 2492 * at the beginning of the extent. Instead, we check to see if we 2493 * need to free it on a subsequent call to ext4_remove_blocks, 2494 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space. 2495 */ 2496 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER; 2497 ext4_free_blocks(handle, inode, NULL, pblk, num, flags); 2498 2499 /* reset the partial cluster if we've freed past it */ 2500 if (partial->state != initial && partial->pclu != EXT4_B2C(sbi, pblk)) 2501 partial->state = initial; 2502 2503 /* 2504 * If we've freed the entire extent but the beginning is not left 2505 * cluster aligned and is not marked as ineligible for freeing we 2506 * record the partial cluster at the beginning of the extent. It 2507 * wasn't freed by the preceding ext4_free_blocks() call, and we 2508 * need to look farther to the left to determine if it's to be freed 2509 * (not shared with another extent). Else, reset the partial 2510 * cluster - we're either done freeing or the beginning of the 2511 * extent is left cluster aligned. 2512 */ 2513 if (EXT4_LBLK_COFF(sbi, from) && num == ee_len) { 2514 if (partial->state == initial) { 2515 partial->pclu = EXT4_B2C(sbi, pblk); 2516 partial->lblk = from; 2517 partial->state = tofree; 2518 } 2519 } else { 2520 partial->state = initial; 2521 } 2522 2523 return 0; 2524 } 2525 2526 /* 2527 * ext4_ext_rm_leaf() Removes the extents associated with the 2528 * blocks appearing between "start" and "end". Both "start" 2529 * and "end" must appear in the same extent or EIO is returned. 2530 * 2531 * @handle: The journal handle 2532 * @inode: The files inode 2533 * @path: The path to the leaf 2534 * @partial_cluster: The cluster which we'll have to free if all extents 2535 * has been released from it. However, if this value is 2536 * negative, it's a cluster just to the right of the 2537 * punched region and it must not be freed. 2538 * @start: The first block to remove 2539 * @end: The last block to remove 2540 */ 2541 static int 2542 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, 2543 struct ext4_ext_path *path, 2544 struct partial_cluster *partial, 2545 ext4_lblk_t start, ext4_lblk_t end) 2546 { 2547 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2548 int err = 0, correct_index = 0; 2549 int depth = ext_depth(inode), credits, revoke_credits; 2550 struct ext4_extent_header *eh; 2551 ext4_lblk_t a, b; 2552 unsigned num; 2553 ext4_lblk_t ex_ee_block; 2554 unsigned short ex_ee_len; 2555 unsigned unwritten = 0; 2556 struct ext4_extent *ex; 2557 ext4_fsblk_t pblk; 2558 2559 /* the header must be checked already in ext4_ext_remove_space() */ 2560 ext_debug(inode, "truncate since %u in leaf to %u\n", start, end); 2561 if (!path[depth].p_hdr) 2562 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); 2563 eh = path[depth].p_hdr; 2564 if (unlikely(path[depth].p_hdr == NULL)) { 2565 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); 2566 return -EFSCORRUPTED; 2567 } 2568 /* find where to start removing */ 2569 ex = path[depth].p_ext; 2570 if (!ex) 2571 ex = EXT_LAST_EXTENT(eh); 2572 2573 ex_ee_block = le32_to_cpu(ex->ee_block); 2574 ex_ee_len = ext4_ext_get_actual_len(ex); 2575 2576 trace_ext4_ext_rm_leaf(inode, start, ex, partial); 2577 2578 while (ex >= EXT_FIRST_EXTENT(eh) && 2579 ex_ee_block + ex_ee_len > start) { 2580 2581 if (ext4_ext_is_unwritten(ex)) 2582 unwritten = 1; 2583 else 2584 unwritten = 0; 2585 2586 ext_debug(inode, "remove ext %u:[%d]%d\n", ex_ee_block, 2587 unwritten, ex_ee_len); 2588 path[depth].p_ext = ex; 2589 2590 a = ex_ee_block > start ? ex_ee_block : start; 2591 b = ex_ee_block+ex_ee_len - 1 < end ? 2592 ex_ee_block+ex_ee_len - 1 : end; 2593 2594 ext_debug(inode, " border %u:%u\n", a, b); 2595 2596 /* If this extent is beyond the end of the hole, skip it */ 2597 if (end < ex_ee_block) { 2598 /* 2599 * We're going to skip this extent and move to another, 2600 * so note that its first cluster is in use to avoid 2601 * freeing it when removing blocks. Eventually, the 2602 * right edge of the truncated/punched region will 2603 * be just to the left. 2604 */ 2605 if (sbi->s_cluster_ratio > 1) { 2606 pblk = ext4_ext_pblock(ex); 2607 partial->pclu = EXT4_B2C(sbi, pblk); 2608 partial->state = nofree; 2609 } 2610 ex--; 2611 ex_ee_block = le32_to_cpu(ex->ee_block); 2612 ex_ee_len = ext4_ext_get_actual_len(ex); 2613 continue; 2614 } else if (b != ex_ee_block + ex_ee_len - 1) { 2615 EXT4_ERROR_INODE(inode, 2616 "can not handle truncate %u:%u " 2617 "on extent %u:%u", 2618 start, end, ex_ee_block, 2619 ex_ee_block + ex_ee_len - 1); 2620 err = -EFSCORRUPTED; 2621 goto out; 2622 } else if (a != ex_ee_block) { 2623 /* remove tail of the extent */ 2624 num = a - ex_ee_block; 2625 } else { 2626 /* remove whole extent: excellent! */ 2627 num = 0; 2628 } 2629 /* 2630 * 3 for leaf, sb, and inode plus 2 (bmap and group 2631 * descriptor) for each block group; assume two block 2632 * groups plus ex_ee_len/blocks_per_block_group for 2633 * the worst case 2634 */ 2635 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb)); 2636 if (ex == EXT_FIRST_EXTENT(eh)) { 2637 correct_index = 1; 2638 credits += (ext_depth(inode)) + 1; 2639 } 2640 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb); 2641 /* 2642 * We may end up freeing some index blocks and data from the 2643 * punched range. Note that partial clusters are accounted for 2644 * by ext4_free_data_revoke_credits(). 2645 */ 2646 revoke_credits = 2647 ext4_free_metadata_revoke_credits(inode->i_sb, 2648 ext_depth(inode)) + 2649 ext4_free_data_revoke_credits(inode, b - a + 1); 2650 2651 err = ext4_datasem_ensure_credits(handle, inode, credits, 2652 credits, revoke_credits); 2653 if (err) { 2654 if (err > 0) 2655 err = -EAGAIN; 2656 goto out; 2657 } 2658 2659 err = ext4_ext_get_access(handle, inode, path + depth); 2660 if (err) 2661 goto out; 2662 2663 err = ext4_remove_blocks(handle, inode, ex, partial, a, b); 2664 if (err) 2665 goto out; 2666 2667 if (num == 0) 2668 /* this extent is removed; mark slot entirely unused */ 2669 ext4_ext_store_pblock(ex, 0); 2670 2671 ex->ee_len = cpu_to_le16(num); 2672 /* 2673 * Do not mark unwritten if all the blocks in the 2674 * extent have been removed. 2675 */ 2676 if (unwritten && num) 2677 ext4_ext_mark_unwritten(ex); 2678 /* 2679 * If the extent was completely released, 2680 * we need to remove it from the leaf 2681 */ 2682 if (num == 0) { 2683 if (end != EXT_MAX_BLOCKS - 1) { 2684 /* 2685 * For hole punching, we need to scoot all the 2686 * extents up when an extent is removed so that 2687 * we dont have blank extents in the middle 2688 */ 2689 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) * 2690 sizeof(struct ext4_extent)); 2691 2692 /* Now get rid of the one at the end */ 2693 memset(EXT_LAST_EXTENT(eh), 0, 2694 sizeof(struct ext4_extent)); 2695 } 2696 le16_add_cpu(&eh->eh_entries, -1); 2697 } 2698 2699 err = ext4_ext_dirty(handle, inode, path + depth); 2700 if (err) 2701 goto out; 2702 2703 ext_debug(inode, "new extent: %u:%u:%llu\n", ex_ee_block, num, 2704 ext4_ext_pblock(ex)); 2705 ex--; 2706 ex_ee_block = le32_to_cpu(ex->ee_block); 2707 ex_ee_len = ext4_ext_get_actual_len(ex); 2708 } 2709 2710 if (correct_index && eh->eh_entries) 2711 err = ext4_ext_correct_indexes(handle, inode, path); 2712 2713 /* 2714 * If there's a partial cluster and at least one extent remains in 2715 * the leaf, free the partial cluster if it isn't shared with the 2716 * current extent. If it is shared with the current extent 2717 * we reset the partial cluster because we've reached the start of the 2718 * truncated/punched region and we're done removing blocks. 2719 */ 2720 if (partial->state == tofree && ex >= EXT_FIRST_EXTENT(eh)) { 2721 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1; 2722 if (partial->pclu != EXT4_B2C(sbi, pblk)) { 2723 int flags = get_default_free_blocks_flags(inode); 2724 2725 if (ext4_is_pending(inode, partial->lblk)) 2726 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; 2727 ext4_free_blocks(handle, inode, NULL, 2728 EXT4_C2B(sbi, partial->pclu), 2729 sbi->s_cluster_ratio, flags); 2730 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) 2731 ext4_rereserve_cluster(inode, partial->lblk); 2732 } 2733 partial->state = initial; 2734 } 2735 2736 /* if this leaf is free, then we should 2737 * remove it from index block above */ 2738 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) 2739 err = ext4_ext_rm_idx(handle, inode, path, depth); 2740 2741 out: 2742 return err; 2743 } 2744 2745 /* 2746 * ext4_ext_more_to_rm: 2747 * returns 1 if current index has to be freed (even partial) 2748 */ 2749 static int 2750 ext4_ext_more_to_rm(struct ext4_ext_path *path) 2751 { 2752 BUG_ON(path->p_idx == NULL); 2753 2754 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) 2755 return 0; 2756 2757 /* 2758 * if truncate on deeper level happened, it wasn't partial, 2759 * so we have to consider current index for truncation 2760 */ 2761 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) 2762 return 0; 2763 return 1; 2764 } 2765 2766 int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, 2767 ext4_lblk_t end) 2768 { 2769 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2770 int depth = ext_depth(inode); 2771 struct ext4_ext_path *path = NULL; 2772 struct partial_cluster partial; 2773 handle_t *handle; 2774 int i = 0, err = 0; 2775 2776 partial.pclu = 0; 2777 partial.lblk = 0; 2778 partial.state = initial; 2779 2780 ext_debug(inode, "truncate since %u to %u\n", start, end); 2781 2782 /* probably first extent we're gonna free will be last in block */ 2783 handle = ext4_journal_start_with_revoke(inode, EXT4_HT_TRUNCATE, 2784 depth + 1, 2785 ext4_free_metadata_revoke_credits(inode->i_sb, depth)); 2786 if (IS_ERR(handle)) 2787 return PTR_ERR(handle); 2788 2789 again: 2790 trace_ext4_ext_remove_space(inode, start, end, depth); 2791 2792 /* 2793 * Check if we are removing extents inside the extent tree. If that 2794 * is the case, we are going to punch a hole inside the extent tree 2795 * so we have to check whether we need to split the extent covering 2796 * the last block to remove so we can easily remove the part of it 2797 * in ext4_ext_rm_leaf(). 2798 */ 2799 if (end < EXT_MAX_BLOCKS - 1) { 2800 struct ext4_extent *ex; 2801 ext4_lblk_t ee_block, ex_end, lblk; 2802 ext4_fsblk_t pblk; 2803 2804 /* find extent for or closest extent to this block */ 2805 path = ext4_find_extent(inode, end, NULL, 2806 EXT4_EX_NOCACHE | EXT4_EX_NOFAIL); 2807 if (IS_ERR(path)) { 2808 ext4_journal_stop(handle); 2809 return PTR_ERR(path); 2810 } 2811 depth = ext_depth(inode); 2812 /* Leaf not may not exist only if inode has no blocks at all */ 2813 ex = path[depth].p_ext; 2814 if (!ex) { 2815 if (depth) { 2816 EXT4_ERROR_INODE(inode, 2817 "path[%d].p_hdr == NULL", 2818 depth); 2819 err = -EFSCORRUPTED; 2820 } 2821 goto out; 2822 } 2823 2824 ee_block = le32_to_cpu(ex->ee_block); 2825 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1; 2826 2827 /* 2828 * See if the last block is inside the extent, if so split 2829 * the extent at 'end' block so we can easily remove the 2830 * tail of the first part of the split extent in 2831 * ext4_ext_rm_leaf(). 2832 */ 2833 if (end >= ee_block && end < ex_end) { 2834 2835 /* 2836 * If we're going to split the extent, note that 2837 * the cluster containing the block after 'end' is 2838 * in use to avoid freeing it when removing blocks. 2839 */ 2840 if (sbi->s_cluster_ratio > 1) { 2841 pblk = ext4_ext_pblock(ex) + end - ee_block + 1; 2842 partial.pclu = EXT4_B2C(sbi, pblk); 2843 partial.state = nofree; 2844 } 2845 2846 /* 2847 * Split the extent in two so that 'end' is the last 2848 * block in the first new extent. Also we should not 2849 * fail removing space due to ENOSPC so try to use 2850 * reserved block if that happens. 2851 */ 2852 err = ext4_force_split_extent_at(handle, inode, &path, 2853 end + 1, 1); 2854 if (err < 0) 2855 goto out; 2856 2857 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end && 2858 partial.state == initial) { 2859 /* 2860 * If we're punching, there's an extent to the right. 2861 * If the partial cluster hasn't been set, set it to 2862 * that extent's first cluster and its state to nofree 2863 * so it won't be freed should it contain blocks to be 2864 * removed. If it's already set (tofree/nofree), we're 2865 * retrying and keep the original partial cluster info 2866 * so a cluster marked tofree as a result of earlier 2867 * extent removal is not lost. 2868 */ 2869 lblk = ex_end + 1; 2870 err = ext4_ext_search_right(inode, path, &lblk, &pblk, 2871 &ex); 2872 if (err) 2873 goto out; 2874 if (pblk) { 2875 partial.pclu = EXT4_B2C(sbi, pblk); 2876 partial.state = nofree; 2877 } 2878 } 2879 } 2880 /* 2881 * We start scanning from right side, freeing all the blocks 2882 * after i_size and walking into the tree depth-wise. 2883 */ 2884 depth = ext_depth(inode); 2885 if (path) { 2886 int k = i = depth; 2887 while (--k > 0) 2888 path[k].p_block = 2889 le16_to_cpu(path[k].p_hdr->eh_entries)+1; 2890 } else { 2891 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path), 2892 GFP_NOFS | __GFP_NOFAIL); 2893 if (path == NULL) { 2894 ext4_journal_stop(handle); 2895 return -ENOMEM; 2896 } 2897 path[0].p_maxdepth = path[0].p_depth = depth; 2898 path[0].p_hdr = ext_inode_hdr(inode); 2899 i = 0; 2900 2901 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) { 2902 err = -EFSCORRUPTED; 2903 goto out; 2904 } 2905 } 2906 err = 0; 2907 2908 while (i >= 0 && err == 0) { 2909 if (i == depth) { 2910 /* this is leaf block */ 2911 err = ext4_ext_rm_leaf(handle, inode, path, 2912 &partial, start, end); 2913 /* root level has p_bh == NULL, brelse() eats this */ 2914 brelse(path[i].p_bh); 2915 path[i].p_bh = NULL; 2916 i--; 2917 continue; 2918 } 2919 2920 /* this is index block */ 2921 if (!path[i].p_hdr) { 2922 ext_debug(inode, "initialize header\n"); 2923 path[i].p_hdr = ext_block_hdr(path[i].p_bh); 2924 } 2925 2926 if (!path[i].p_idx) { 2927 /* this level hasn't been touched yet */ 2928 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); 2929 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; 2930 ext_debug(inode, "init index ptr: hdr 0x%p, num %d\n", 2931 path[i].p_hdr, 2932 le16_to_cpu(path[i].p_hdr->eh_entries)); 2933 } else { 2934 /* we were already here, see at next index */ 2935 path[i].p_idx--; 2936 } 2937 2938 ext_debug(inode, "level %d - index, first 0x%p, cur 0x%p\n", 2939 i, EXT_FIRST_INDEX(path[i].p_hdr), 2940 path[i].p_idx); 2941 if (ext4_ext_more_to_rm(path + i)) { 2942 struct buffer_head *bh; 2943 /* go to the next level */ 2944 ext_debug(inode, "move to level %d (block %llu)\n", 2945 i + 1, ext4_idx_pblock(path[i].p_idx)); 2946 memset(path + i + 1, 0, sizeof(*path)); 2947 bh = read_extent_tree_block(inode, 2948 ext4_idx_pblock(path[i].p_idx), depth - i - 1, 2949 EXT4_EX_NOCACHE); 2950 if (IS_ERR(bh)) { 2951 /* should we reset i_size? */ 2952 err = PTR_ERR(bh); 2953 break; 2954 } 2955 /* Yield here to deal with large extent trees. 2956 * Should be a no-op if we did IO above. */ 2957 cond_resched(); 2958 if (WARN_ON(i + 1 > depth)) { 2959 err = -EFSCORRUPTED; 2960 break; 2961 } 2962 path[i + 1].p_bh = bh; 2963 2964 /* save actual number of indexes since this 2965 * number is changed at the next iteration */ 2966 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); 2967 i++; 2968 } else { 2969 /* we finished processing this index, go up */ 2970 if (path[i].p_hdr->eh_entries == 0 && i > 0) { 2971 /* index is empty, remove it; 2972 * handle must be already prepared by the 2973 * truncatei_leaf() */ 2974 err = ext4_ext_rm_idx(handle, inode, path, i); 2975 } 2976 /* root level has p_bh == NULL, brelse() eats this */ 2977 brelse(path[i].p_bh); 2978 path[i].p_bh = NULL; 2979 i--; 2980 ext_debug(inode, "return to level %d\n", i); 2981 } 2982 } 2983 2984 trace_ext4_ext_remove_space_done(inode, start, end, depth, &partial, 2985 path->p_hdr->eh_entries); 2986 2987 /* 2988 * if there's a partial cluster and we have removed the first extent 2989 * in the file, then we also free the partial cluster, if any 2990 */ 2991 if (partial.state == tofree && err == 0) { 2992 int flags = get_default_free_blocks_flags(inode); 2993 2994 if (ext4_is_pending(inode, partial.lblk)) 2995 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; 2996 ext4_free_blocks(handle, inode, NULL, 2997 EXT4_C2B(sbi, partial.pclu), 2998 sbi->s_cluster_ratio, flags); 2999 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) 3000 ext4_rereserve_cluster(inode, partial.lblk); 3001 partial.state = initial; 3002 } 3003 3004 /* TODO: flexible tree reduction should be here */ 3005 if (path->p_hdr->eh_entries == 0) { 3006 /* 3007 * truncate to zero freed all the tree, 3008 * so we need to correct eh_depth 3009 */ 3010 err = ext4_ext_get_access(handle, inode, path); 3011 if (err == 0) { 3012 ext_inode_hdr(inode)->eh_depth = 0; 3013 ext_inode_hdr(inode)->eh_max = 3014 cpu_to_le16(ext4_ext_space_root(inode, 0)); 3015 err = ext4_ext_dirty(handle, inode, path); 3016 } 3017 } 3018 out: 3019 ext4_ext_drop_refs(path); 3020 kfree(path); 3021 path = NULL; 3022 if (err == -EAGAIN) 3023 goto again; 3024 ext4_journal_stop(handle); 3025 3026 return err; 3027 } 3028 3029 /* 3030 * called at mount time 3031 */ 3032 void ext4_ext_init(struct super_block *sb) 3033 { 3034 /* 3035 * possible initialization would be here 3036 */ 3037 3038 if (ext4_has_feature_extents(sb)) { 3039 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS) 3040 printk(KERN_INFO "EXT4-fs: file extents enabled" 3041 #ifdef AGGRESSIVE_TEST 3042 ", aggressive tests" 3043 #endif 3044 #ifdef CHECK_BINSEARCH 3045 ", check binsearch" 3046 #endif 3047 #ifdef EXTENTS_STATS 3048 ", stats" 3049 #endif 3050 "\n"); 3051 #endif 3052 #ifdef EXTENTS_STATS 3053 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); 3054 EXT4_SB(sb)->s_ext_min = 1 << 30; 3055 EXT4_SB(sb)->s_ext_max = 0; 3056 #endif 3057 } 3058 } 3059 3060 /* 3061 * called at umount time 3062 */ 3063 void ext4_ext_release(struct super_block *sb) 3064 { 3065 if (!ext4_has_feature_extents(sb)) 3066 return; 3067 3068 #ifdef EXTENTS_STATS 3069 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { 3070 struct ext4_sb_info *sbi = EXT4_SB(sb); 3071 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", 3072 sbi->s_ext_blocks, sbi->s_ext_extents, 3073 sbi->s_ext_blocks / sbi->s_ext_extents); 3074 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", 3075 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); 3076 } 3077 #endif 3078 } 3079 3080 static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex) 3081 { 3082 ext4_lblk_t ee_block; 3083 ext4_fsblk_t ee_pblock; 3084 unsigned int ee_len; 3085 3086 ee_block = le32_to_cpu(ex->ee_block); 3087 ee_len = ext4_ext_get_actual_len(ex); 3088 ee_pblock = ext4_ext_pblock(ex); 3089 3090 if (ee_len == 0) 3091 return 0; 3092 3093 return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock, 3094 EXTENT_STATUS_WRITTEN); 3095 } 3096 3097 /* FIXME!! we need to try to merge to left or right after zero-out */ 3098 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) 3099 { 3100 ext4_fsblk_t ee_pblock; 3101 unsigned int ee_len; 3102 3103 ee_len = ext4_ext_get_actual_len(ex); 3104 ee_pblock = ext4_ext_pblock(ex); 3105 return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock, 3106 ee_len); 3107 } 3108 3109 /* 3110 * ext4_split_extent_at() splits an extent at given block. 3111 * 3112 * @handle: the journal handle 3113 * @inode: the file inode 3114 * @path: the path to the extent 3115 * @split: the logical block where the extent is splitted. 3116 * @split_flags: indicates if the extent could be zeroout if split fails, and 3117 * the states(init or unwritten) of new extents. 3118 * @flags: flags used to insert new extent to extent tree. 3119 * 3120 * 3121 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states 3122 * of which are determined by split_flag. 3123 * 3124 * There are two cases: 3125 * a> the extent are splitted into two extent. 3126 * b> split is not needed, and just mark the extent. 3127 * 3128 * return 0 on success. 3129 */ 3130 static int ext4_split_extent_at(handle_t *handle, 3131 struct inode *inode, 3132 struct ext4_ext_path **ppath, 3133 ext4_lblk_t split, 3134 int split_flag, 3135 int flags) 3136 { 3137 struct ext4_ext_path *path = *ppath; 3138 ext4_fsblk_t newblock; 3139 ext4_lblk_t ee_block; 3140 struct ext4_extent *ex, newex, orig_ex, zero_ex; 3141 struct ext4_extent *ex2 = NULL; 3142 unsigned int ee_len, depth; 3143 int err = 0; 3144 3145 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) == 3146 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)); 3147 3148 ext_debug(inode, "logical block %llu\n", (unsigned long long)split); 3149 3150 ext4_ext_show_leaf(inode, path); 3151 3152 depth = ext_depth(inode); 3153 ex = path[depth].p_ext; 3154 ee_block = le32_to_cpu(ex->ee_block); 3155 ee_len = ext4_ext_get_actual_len(ex); 3156 newblock = split - ee_block + ext4_ext_pblock(ex); 3157 3158 BUG_ON(split < ee_block || split >= (ee_block + ee_len)); 3159 BUG_ON(!ext4_ext_is_unwritten(ex) && 3160 split_flag & (EXT4_EXT_MAY_ZEROOUT | 3161 EXT4_EXT_MARK_UNWRIT1 | 3162 EXT4_EXT_MARK_UNWRIT2)); 3163 3164 err = ext4_ext_get_access(handle, inode, path + depth); 3165 if (err) 3166 goto out; 3167 3168 if (split == ee_block) { 3169 /* 3170 * case b: block @split is the block that the extent begins with 3171 * then we just change the state of the extent, and splitting 3172 * is not needed. 3173 */ 3174 if (split_flag & EXT4_EXT_MARK_UNWRIT2) 3175 ext4_ext_mark_unwritten(ex); 3176 else 3177 ext4_ext_mark_initialized(ex); 3178 3179 if (!(flags & EXT4_GET_BLOCKS_PRE_IO)) 3180 ext4_ext_try_to_merge(handle, inode, path, ex); 3181 3182 err = ext4_ext_dirty(handle, inode, path + path->p_depth); 3183 goto out; 3184 } 3185 3186 /* case a */ 3187 memcpy(&orig_ex, ex, sizeof(orig_ex)); 3188 ex->ee_len = cpu_to_le16(split - ee_block); 3189 if (split_flag & EXT4_EXT_MARK_UNWRIT1) 3190 ext4_ext_mark_unwritten(ex); 3191 3192 /* 3193 * path may lead to new leaf, not to original leaf any more 3194 * after ext4_ext_insert_extent() returns, 3195 */ 3196 err = ext4_ext_dirty(handle, inode, path + depth); 3197 if (err) 3198 goto fix_extent_len; 3199 3200 ex2 = &newex; 3201 ex2->ee_block = cpu_to_le32(split); 3202 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block)); 3203 ext4_ext_store_pblock(ex2, newblock); 3204 if (split_flag & EXT4_EXT_MARK_UNWRIT2) 3205 ext4_ext_mark_unwritten(ex2); 3206 3207 err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags); 3208 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) { 3209 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) { 3210 if (split_flag & EXT4_EXT_DATA_VALID1) { 3211 err = ext4_ext_zeroout(inode, ex2); 3212 zero_ex.ee_block = ex2->ee_block; 3213 zero_ex.ee_len = cpu_to_le16( 3214 ext4_ext_get_actual_len(ex2)); 3215 ext4_ext_store_pblock(&zero_ex, 3216 ext4_ext_pblock(ex2)); 3217 } else { 3218 err = ext4_ext_zeroout(inode, ex); 3219 zero_ex.ee_block = ex->ee_block; 3220 zero_ex.ee_len = cpu_to_le16( 3221 ext4_ext_get_actual_len(ex)); 3222 ext4_ext_store_pblock(&zero_ex, 3223 ext4_ext_pblock(ex)); 3224 } 3225 } else { 3226 err = ext4_ext_zeroout(inode, &orig_ex); 3227 zero_ex.ee_block = orig_ex.ee_block; 3228 zero_ex.ee_len = cpu_to_le16( 3229 ext4_ext_get_actual_len(&orig_ex)); 3230 ext4_ext_store_pblock(&zero_ex, 3231 ext4_ext_pblock(&orig_ex)); 3232 } 3233 3234 if (err) 3235 goto fix_extent_len; 3236 /* update the extent length and mark as initialized */ 3237 ex->ee_len = cpu_to_le16(ee_len); 3238 ext4_ext_try_to_merge(handle, inode, path, ex); 3239 err = ext4_ext_dirty(handle, inode, path + path->p_depth); 3240 if (err) 3241 goto fix_extent_len; 3242 3243 /* update extent status tree */ 3244 err = ext4_zeroout_es(inode, &zero_ex); 3245 3246 goto out; 3247 } else if (err) 3248 goto fix_extent_len; 3249 3250 out: 3251 ext4_ext_show_leaf(inode, path); 3252 return err; 3253 3254 fix_extent_len: 3255 ex->ee_len = orig_ex.ee_len; 3256 /* 3257 * Ignore ext4_ext_dirty return value since we are already in error path 3258 * and err is a non-zero error code. 3259 */ 3260 ext4_ext_dirty(handle, inode, path + path->p_depth); 3261 return err; 3262 } 3263 3264 /* 3265 * ext4_split_extents() splits an extent and mark extent which is covered 3266 * by @map as split_flags indicates 3267 * 3268 * It may result in splitting the extent into multiple extents (up to three) 3269 * There are three possibilities: 3270 * a> There is no split required 3271 * b> Splits in two extents: Split is happening at either end of the extent 3272 * c> Splits in three extents: Somone is splitting in middle of the extent 3273 * 3274 */ 3275 static int ext4_split_extent(handle_t *handle, 3276 struct inode *inode, 3277 struct ext4_ext_path **ppath, 3278 struct ext4_map_blocks *map, 3279 int split_flag, 3280 int flags) 3281 { 3282 struct ext4_ext_path *path = *ppath; 3283 ext4_lblk_t ee_block; 3284 struct ext4_extent *ex; 3285 unsigned int ee_len, depth; 3286 int err = 0; 3287 int unwritten; 3288 int split_flag1, flags1; 3289 int allocated = map->m_len; 3290 3291 depth = ext_depth(inode); 3292 ex = path[depth].p_ext; 3293 ee_block = le32_to_cpu(ex->ee_block); 3294 ee_len = ext4_ext_get_actual_len(ex); 3295 unwritten = ext4_ext_is_unwritten(ex); 3296 3297 if (map->m_lblk + map->m_len < ee_block + ee_len) { 3298 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT; 3299 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO; 3300 if (unwritten) 3301 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 | 3302 EXT4_EXT_MARK_UNWRIT2; 3303 if (split_flag & EXT4_EXT_DATA_VALID2) 3304 split_flag1 |= EXT4_EXT_DATA_VALID1; 3305 err = ext4_split_extent_at(handle, inode, ppath, 3306 map->m_lblk + map->m_len, split_flag1, flags1); 3307 if (err) 3308 goto out; 3309 } else { 3310 allocated = ee_len - (map->m_lblk - ee_block); 3311 } 3312 /* 3313 * Update path is required because previous ext4_split_extent_at() may 3314 * result in split of original leaf or extent zeroout. 3315 */ 3316 path = ext4_find_extent(inode, map->m_lblk, ppath, flags); 3317 if (IS_ERR(path)) 3318 return PTR_ERR(path); 3319 depth = ext_depth(inode); 3320 ex = path[depth].p_ext; 3321 if (!ex) { 3322 EXT4_ERROR_INODE(inode, "unexpected hole at %lu", 3323 (unsigned long) map->m_lblk); 3324 return -EFSCORRUPTED; 3325 } 3326 unwritten = ext4_ext_is_unwritten(ex); 3327 split_flag1 = 0; 3328 3329 if (map->m_lblk >= ee_block) { 3330 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2; 3331 if (unwritten) { 3332 split_flag1 |= EXT4_EXT_MARK_UNWRIT1; 3333 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT | 3334 EXT4_EXT_MARK_UNWRIT2); 3335 } 3336 err = ext4_split_extent_at(handle, inode, ppath, 3337 map->m_lblk, split_flag1, flags); 3338 if (err) 3339 goto out; 3340 } 3341 3342 ext4_ext_show_leaf(inode, path); 3343 out: 3344 return err ? err : allocated; 3345 } 3346 3347 /* 3348 * This function is called by ext4_ext_map_blocks() if someone tries to write 3349 * to an unwritten extent. It may result in splitting the unwritten 3350 * extent into multiple extents (up to three - one initialized and two 3351 * unwritten). 3352 * There are three possibilities: 3353 * a> There is no split required: Entire extent should be initialized 3354 * b> Splits in two extents: Write is happening at either end of the extent 3355 * c> Splits in three extents: Somone is writing in middle of the extent 3356 * 3357 * Pre-conditions: 3358 * - The extent pointed to by 'path' is unwritten. 3359 * - The extent pointed to by 'path' contains a superset 3360 * of the logical span [map->m_lblk, map->m_lblk + map->m_len). 3361 * 3362 * Post-conditions on success: 3363 * - the returned value is the number of blocks beyond map->l_lblk 3364 * that are allocated and initialized. 3365 * It is guaranteed to be >= map->m_len. 3366 */ 3367 static int ext4_ext_convert_to_initialized(handle_t *handle, 3368 struct inode *inode, 3369 struct ext4_map_blocks *map, 3370 struct ext4_ext_path **ppath, 3371 int flags) 3372 { 3373 struct ext4_ext_path *path = *ppath; 3374 struct ext4_sb_info *sbi; 3375 struct ext4_extent_header *eh; 3376 struct ext4_map_blocks split_map; 3377 struct ext4_extent zero_ex1, zero_ex2; 3378 struct ext4_extent *ex, *abut_ex; 3379 ext4_lblk_t ee_block, eof_block; 3380 unsigned int ee_len, depth, map_len = map->m_len; 3381 int allocated = 0, max_zeroout = 0; 3382 int err = 0; 3383 int split_flag = EXT4_EXT_DATA_VALID2; 3384 3385 ext_debug(inode, "logical block %llu, max_blocks %u\n", 3386 (unsigned long long)map->m_lblk, map_len); 3387 3388 sbi = EXT4_SB(inode->i_sb); 3389 eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1) 3390 >> inode->i_sb->s_blocksize_bits; 3391 if (eof_block < map->m_lblk + map_len) 3392 eof_block = map->m_lblk + map_len; 3393 3394 depth = ext_depth(inode); 3395 eh = path[depth].p_hdr; 3396 ex = path[depth].p_ext; 3397 ee_block = le32_to_cpu(ex->ee_block); 3398 ee_len = ext4_ext_get_actual_len(ex); 3399 zero_ex1.ee_len = 0; 3400 zero_ex2.ee_len = 0; 3401 3402 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex); 3403 3404 /* Pre-conditions */ 3405 BUG_ON(!ext4_ext_is_unwritten(ex)); 3406 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len)); 3407 3408 /* 3409 * Attempt to transfer newly initialized blocks from the currently 3410 * unwritten extent to its neighbor. This is much cheaper 3411 * than an insertion followed by a merge as those involve costly 3412 * memmove() calls. Transferring to the left is the common case in 3413 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE) 3414 * followed by append writes. 3415 * 3416 * Limitations of the current logic: 3417 * - L1: we do not deal with writes covering the whole extent. 3418 * This would require removing the extent if the transfer 3419 * is possible. 3420 * - L2: we only attempt to merge with an extent stored in the 3421 * same extent tree node. 3422 */ 3423 if ((map->m_lblk == ee_block) && 3424 /* See if we can merge left */ 3425 (map_len < ee_len) && /*L1*/ 3426 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/ 3427 ext4_lblk_t prev_lblk; 3428 ext4_fsblk_t prev_pblk, ee_pblk; 3429 unsigned int prev_len; 3430 3431 abut_ex = ex - 1; 3432 prev_lblk = le32_to_cpu(abut_ex->ee_block); 3433 prev_len = ext4_ext_get_actual_len(abut_ex); 3434 prev_pblk = ext4_ext_pblock(abut_ex); 3435 ee_pblk = ext4_ext_pblock(ex); 3436 3437 /* 3438 * A transfer of blocks from 'ex' to 'abut_ex' is allowed 3439 * upon those conditions: 3440 * - C1: abut_ex is initialized, 3441 * - C2: abut_ex is logically abutting ex, 3442 * - C3: abut_ex is physically abutting ex, 3443 * - C4: abut_ex can receive the additional blocks without 3444 * overflowing the (initialized) length limit. 3445 */ 3446 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/ 3447 ((prev_lblk + prev_len) == ee_block) && /*C2*/ 3448 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/ 3449 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/ 3450 err = ext4_ext_get_access(handle, inode, path + depth); 3451 if (err) 3452 goto out; 3453 3454 trace_ext4_ext_convert_to_initialized_fastpath(inode, 3455 map, ex, abut_ex); 3456 3457 /* Shift the start of ex by 'map_len' blocks */ 3458 ex->ee_block = cpu_to_le32(ee_block + map_len); 3459 ext4_ext_store_pblock(ex, ee_pblk + map_len); 3460 ex->ee_len = cpu_to_le16(ee_len - map_len); 3461 ext4_ext_mark_unwritten(ex); /* Restore the flag */ 3462 3463 /* Extend abut_ex by 'map_len' blocks */ 3464 abut_ex->ee_len = cpu_to_le16(prev_len + map_len); 3465 3466 /* Result: number of initialized blocks past m_lblk */ 3467 allocated = map_len; 3468 } 3469 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) && 3470 (map_len < ee_len) && /*L1*/ 3471 ex < EXT_LAST_EXTENT(eh)) { /*L2*/ 3472 /* See if we can merge right */ 3473 ext4_lblk_t next_lblk; 3474 ext4_fsblk_t next_pblk, ee_pblk; 3475 unsigned int next_len; 3476 3477 abut_ex = ex + 1; 3478 next_lblk = le32_to_cpu(abut_ex->ee_block); 3479 next_len = ext4_ext_get_actual_len(abut_ex); 3480 next_pblk = ext4_ext_pblock(abut_ex); 3481 ee_pblk = ext4_ext_pblock(ex); 3482 3483 /* 3484 * A transfer of blocks from 'ex' to 'abut_ex' is allowed 3485 * upon those conditions: 3486 * - C1: abut_ex is initialized, 3487 * - C2: abut_ex is logically abutting ex, 3488 * - C3: abut_ex is physically abutting ex, 3489 * - C4: abut_ex can receive the additional blocks without 3490 * overflowing the (initialized) length limit. 3491 */ 3492 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/ 3493 ((map->m_lblk + map_len) == next_lblk) && /*C2*/ 3494 ((ee_pblk + ee_len) == next_pblk) && /*C3*/ 3495 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/ 3496 err = ext4_ext_get_access(handle, inode, path + depth); 3497 if (err) 3498 goto out; 3499 3500 trace_ext4_ext_convert_to_initialized_fastpath(inode, 3501 map, ex, abut_ex); 3502 3503 /* Shift the start of abut_ex by 'map_len' blocks */ 3504 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len); 3505 ext4_ext_store_pblock(abut_ex, next_pblk - map_len); 3506 ex->ee_len = cpu_to_le16(ee_len - map_len); 3507 ext4_ext_mark_unwritten(ex); /* Restore the flag */ 3508 3509 /* Extend abut_ex by 'map_len' blocks */ 3510 abut_ex->ee_len = cpu_to_le16(next_len + map_len); 3511 3512 /* Result: number of initialized blocks past m_lblk */ 3513 allocated = map_len; 3514 } 3515 } 3516 if (allocated) { 3517 /* Mark the block containing both extents as dirty */ 3518 err = ext4_ext_dirty(handle, inode, path + depth); 3519 3520 /* Update path to point to the right extent */ 3521 path[depth].p_ext = abut_ex; 3522 goto out; 3523 } else 3524 allocated = ee_len - (map->m_lblk - ee_block); 3525 3526 WARN_ON(map->m_lblk < ee_block); 3527 /* 3528 * It is safe to convert extent to initialized via explicit 3529 * zeroout only if extent is fully inside i_size or new_size. 3530 */ 3531 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; 3532 3533 if (EXT4_EXT_MAY_ZEROOUT & split_flag) 3534 max_zeroout = sbi->s_extent_max_zeroout_kb >> 3535 (inode->i_sb->s_blocksize_bits - 10); 3536 3537 /* 3538 * five cases: 3539 * 1. split the extent into three extents. 3540 * 2. split the extent into two extents, zeroout the head of the first 3541 * extent. 3542 * 3. split the extent into two extents, zeroout the tail of the second 3543 * extent. 3544 * 4. split the extent into two extents with out zeroout. 3545 * 5. no splitting needed, just possibly zeroout the head and / or the 3546 * tail of the extent. 3547 */ 3548 split_map.m_lblk = map->m_lblk; 3549 split_map.m_len = map->m_len; 3550 3551 if (max_zeroout && (allocated > split_map.m_len)) { 3552 if (allocated <= max_zeroout) { 3553 /* case 3 or 5 */ 3554 zero_ex1.ee_block = 3555 cpu_to_le32(split_map.m_lblk + 3556 split_map.m_len); 3557 zero_ex1.ee_len = 3558 cpu_to_le16(allocated - split_map.m_len); 3559 ext4_ext_store_pblock(&zero_ex1, 3560 ext4_ext_pblock(ex) + split_map.m_lblk + 3561 split_map.m_len - ee_block); 3562 err = ext4_ext_zeroout(inode, &zero_ex1); 3563 if (err) 3564 goto out; 3565 split_map.m_len = allocated; 3566 } 3567 if (split_map.m_lblk - ee_block + split_map.m_len < 3568 max_zeroout) { 3569 /* case 2 or 5 */ 3570 if (split_map.m_lblk != ee_block) { 3571 zero_ex2.ee_block = ex->ee_block; 3572 zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk - 3573 ee_block); 3574 ext4_ext_store_pblock(&zero_ex2, 3575 ext4_ext_pblock(ex)); 3576 err = ext4_ext_zeroout(inode, &zero_ex2); 3577 if (err) 3578 goto out; 3579 } 3580 3581 split_map.m_len += split_map.m_lblk - ee_block; 3582 split_map.m_lblk = ee_block; 3583 allocated = map->m_len; 3584 } 3585 } 3586 3587 err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag, 3588 flags); 3589 if (err > 0) 3590 err = 0; 3591 out: 3592 /* If we have gotten a failure, don't zero out status tree */ 3593 if (!err) { 3594 err = ext4_zeroout_es(inode, &zero_ex1); 3595 if (!err) 3596 err = ext4_zeroout_es(inode, &zero_ex2); 3597 } 3598 return err ? err : allocated; 3599 } 3600 3601 /* 3602 * This function is called by ext4_ext_map_blocks() from 3603 * ext4_get_blocks_dio_write() when DIO to write 3604 * to an unwritten extent. 3605 * 3606 * Writing to an unwritten extent may result in splitting the unwritten 3607 * extent into multiple initialized/unwritten extents (up to three) 3608 * There are three possibilities: 3609 * a> There is no split required: Entire extent should be unwritten 3610 * b> Splits in two extents: Write is happening at either end of the extent 3611 * c> Splits in three extents: Somone is writing in middle of the extent 3612 * 3613 * This works the same way in the case of initialized -> unwritten conversion. 3614 * 3615 * One of more index blocks maybe needed if the extent tree grow after 3616 * the unwritten extent split. To prevent ENOSPC occur at the IO 3617 * complete, we need to split the unwritten extent before DIO submit 3618 * the IO. The unwritten extent called at this time will be split 3619 * into three unwritten extent(at most). After IO complete, the part 3620 * being filled will be convert to initialized by the end_io callback function 3621 * via ext4_convert_unwritten_extents(). 3622 * 3623 * Returns the size of unwritten extent to be written on success. 3624 */ 3625 static int ext4_split_convert_extents(handle_t *handle, 3626 struct inode *inode, 3627 struct ext4_map_blocks *map, 3628 struct ext4_ext_path **ppath, 3629 int flags) 3630 { 3631 struct ext4_ext_path *path = *ppath; 3632 ext4_lblk_t eof_block; 3633 ext4_lblk_t ee_block; 3634 struct ext4_extent *ex; 3635 unsigned int ee_len; 3636 int split_flag = 0, depth; 3637 3638 ext_debug(inode, "logical block %llu, max_blocks %u\n", 3639 (unsigned long long)map->m_lblk, map->m_len); 3640 3641 eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1) 3642 >> inode->i_sb->s_blocksize_bits; 3643 if (eof_block < map->m_lblk + map->m_len) 3644 eof_block = map->m_lblk + map->m_len; 3645 /* 3646 * It is safe to convert extent to initialized via explicit 3647 * zeroout only if extent is fully inside i_size or new_size. 3648 */ 3649 depth = ext_depth(inode); 3650 ex = path[depth].p_ext; 3651 ee_block = le32_to_cpu(ex->ee_block); 3652 ee_len = ext4_ext_get_actual_len(ex); 3653 3654 /* Convert to unwritten */ 3655 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) { 3656 split_flag |= EXT4_EXT_DATA_VALID1; 3657 /* Convert to initialized */ 3658 } else if (flags & EXT4_GET_BLOCKS_CONVERT) { 3659 split_flag |= ee_block + ee_len <= eof_block ? 3660 EXT4_EXT_MAY_ZEROOUT : 0; 3661 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2); 3662 } 3663 flags |= EXT4_GET_BLOCKS_PRE_IO; 3664 return ext4_split_extent(handle, inode, ppath, map, split_flag, flags); 3665 } 3666 3667 static int ext4_convert_unwritten_extents_endio(handle_t *handle, 3668 struct inode *inode, 3669 struct ext4_map_blocks *map, 3670 struct ext4_ext_path **ppath) 3671 { 3672 struct ext4_ext_path *path = *ppath; 3673 struct ext4_extent *ex; 3674 ext4_lblk_t ee_block; 3675 unsigned int ee_len; 3676 int depth; 3677 int err = 0; 3678 3679 depth = ext_depth(inode); 3680 ex = path[depth].p_ext; 3681 ee_block = le32_to_cpu(ex->ee_block); 3682 ee_len = ext4_ext_get_actual_len(ex); 3683 3684 ext_debug(inode, "logical block %llu, max_blocks %u\n", 3685 (unsigned long long)ee_block, ee_len); 3686 3687 /* If extent is larger than requested it is a clear sign that we still 3688 * have some extent state machine issues left. So extent_split is still 3689 * required. 3690 * TODO: Once all related issues will be fixed this situation should be 3691 * illegal. 3692 */ 3693 if (ee_block != map->m_lblk || ee_len > map->m_len) { 3694 #ifdef CONFIG_EXT4_DEBUG 3695 ext4_warning(inode->i_sb, "Inode (%ld) finished: extent logical block %llu," 3696 " len %u; IO logical block %llu, len %u", 3697 inode->i_ino, (unsigned long long)ee_block, ee_len, 3698 (unsigned long long)map->m_lblk, map->m_len); 3699 #endif 3700 err = ext4_split_convert_extents(handle, inode, map, ppath, 3701 EXT4_GET_BLOCKS_CONVERT); 3702 if (err < 0) 3703 return err; 3704 path = ext4_find_extent(inode, map->m_lblk, ppath, 0); 3705 if (IS_ERR(path)) 3706 return PTR_ERR(path); 3707 depth = ext_depth(inode); 3708 ex = path[depth].p_ext; 3709 } 3710 3711 err = ext4_ext_get_access(handle, inode, path + depth); 3712 if (err) 3713 goto out; 3714 /* first mark the extent as initialized */ 3715 ext4_ext_mark_initialized(ex); 3716 3717 /* note: ext4_ext_correct_indexes() isn't needed here because 3718 * borders are not changed 3719 */ 3720 ext4_ext_try_to_merge(handle, inode, path, ex); 3721 3722 /* Mark modified extent as dirty */ 3723 err = ext4_ext_dirty(handle, inode, path + path->p_depth); 3724 out: 3725 ext4_ext_show_leaf(inode, path); 3726 ext4_fc_track_range(inode, ee_block, ee_block + ee_len - 1); 3727 return err; 3728 } 3729 3730 static int 3731 convert_initialized_extent(handle_t *handle, struct inode *inode, 3732 struct ext4_map_blocks *map, 3733 struct ext4_ext_path **ppath, 3734 unsigned int *allocated) 3735 { 3736 struct ext4_ext_path *path = *ppath; 3737 struct ext4_extent *ex; 3738 ext4_lblk_t ee_block; 3739 unsigned int ee_len; 3740 int depth; 3741 int err = 0; 3742 3743 /* 3744 * Make sure that the extent is no bigger than we support with 3745 * unwritten extent 3746 */ 3747 if (map->m_len > EXT_UNWRITTEN_MAX_LEN) 3748 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2; 3749 3750 depth = ext_depth(inode); 3751 ex = path[depth].p_ext; 3752 ee_block = le32_to_cpu(ex->ee_block); 3753 ee_len = ext4_ext_get_actual_len(ex); 3754 3755 ext_debug(inode, "logical block %llu, max_blocks %u\n", 3756 (unsigned long long)ee_block, ee_len); 3757 3758 if (ee_block != map->m_lblk || ee_len > map->m_len) { 3759 err = ext4_split_convert_extents(handle, inode, map, ppath, 3760 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN); 3761 if (err < 0) 3762 return err; 3763 path = ext4_find_extent(inode, map->m_lblk, ppath, 0); 3764 if (IS_ERR(path)) 3765 return PTR_ERR(path); 3766 depth = ext_depth(inode); 3767 ex = path[depth].p_ext; 3768 if (!ex) { 3769 EXT4_ERROR_INODE(inode, "unexpected hole at %lu", 3770 (unsigned long) map->m_lblk); 3771 return -EFSCORRUPTED; 3772 } 3773 } 3774 3775 err = ext4_ext_get_access(handle, inode, path + depth); 3776 if (err) 3777 return err; 3778 /* first mark the extent as unwritten */ 3779 ext4_ext_mark_unwritten(ex); 3780 3781 /* note: ext4_ext_correct_indexes() isn't needed here because 3782 * borders are not changed 3783 */ 3784 ext4_ext_try_to_merge(handle, inode, path, ex); 3785 3786 /* Mark modified extent as dirty */ 3787 err = ext4_ext_dirty(handle, inode, path + path->p_depth); 3788 if (err) 3789 return err; 3790 ext4_ext_show_leaf(inode, path); 3791 3792 ext4_update_inode_fsync_trans(handle, inode, 1); 3793 3794 map->m_flags |= EXT4_MAP_UNWRITTEN; 3795 if (*allocated > map->m_len) 3796 *allocated = map->m_len; 3797 map->m_len = *allocated; 3798 ext4_fc_track_range(inode, ee_block, ee_block + ee_len - 1); 3799 return 0; 3800 } 3801 3802 static int 3803 ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, 3804 struct ext4_map_blocks *map, 3805 struct ext4_ext_path **ppath, int flags, 3806 unsigned int allocated, ext4_fsblk_t newblock) 3807 { 3808 struct ext4_ext_path __maybe_unused *path = *ppath; 3809 int ret = 0; 3810 int err = 0; 3811 3812 ext_debug(inode, "logical block %llu, max_blocks %u, flags 0x%x, allocated %u\n", 3813 (unsigned long long)map->m_lblk, map->m_len, flags, 3814 allocated); 3815 ext4_ext_show_leaf(inode, path); 3816 3817 /* 3818 * When writing into unwritten space, we should not fail to 3819 * allocate metadata blocks for the new extent block if needed. 3820 */ 3821 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL; 3822 3823 trace_ext4_ext_handle_unwritten_extents(inode, map, flags, 3824 allocated, newblock); 3825 3826 /* get_block() before submitting IO, split the extent */ 3827 if (flags & EXT4_GET_BLOCKS_PRE_IO) { 3828 ret = ext4_split_convert_extents(handle, inode, map, ppath, 3829 flags | EXT4_GET_BLOCKS_CONVERT); 3830 if (ret < 0) { 3831 err = ret; 3832 goto out2; 3833 } 3834 /* 3835 * shouldn't get a 0 return when splitting an extent unless 3836 * m_len is 0 (bug) or extent has been corrupted 3837 */ 3838 if (unlikely(ret == 0)) { 3839 EXT4_ERROR_INODE(inode, 3840 "unexpected ret == 0, m_len = %u", 3841 map->m_len); 3842 err = -EFSCORRUPTED; 3843 goto out2; 3844 } 3845 map->m_flags |= EXT4_MAP_UNWRITTEN; 3846 goto out; 3847 } 3848 /* IO end_io complete, convert the filled extent to written */ 3849 if (flags & EXT4_GET_BLOCKS_CONVERT) { 3850 err = ext4_convert_unwritten_extents_endio(handle, inode, map, 3851 ppath); 3852 if (err < 0) 3853 goto out2; 3854 ext4_update_inode_fsync_trans(handle, inode, 1); 3855 goto map_out; 3856 } 3857 /* buffered IO cases */ 3858 /* 3859 * repeat fallocate creation request 3860 * we already have an unwritten extent 3861 */ 3862 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) { 3863 map->m_flags |= EXT4_MAP_UNWRITTEN; 3864 goto map_out; 3865 } 3866 3867 /* buffered READ or buffered write_begin() lookup */ 3868 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { 3869 /* 3870 * We have blocks reserved already. We 3871 * return allocated blocks so that delalloc 3872 * won't do block reservation for us. But 3873 * the buffer head will be unmapped so that 3874 * a read from the block returns 0s. 3875 */ 3876 map->m_flags |= EXT4_MAP_UNWRITTEN; 3877 goto out1; 3878 } 3879 3880 /* 3881 * Default case when (flags & EXT4_GET_BLOCKS_CREATE) == 1. 3882 * For buffered writes, at writepage time, etc. Convert a 3883 * discovered unwritten extent to written. 3884 */ 3885 ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags); 3886 if (ret < 0) { 3887 err = ret; 3888 goto out2; 3889 } 3890 ext4_update_inode_fsync_trans(handle, inode, 1); 3891 /* 3892 * shouldn't get a 0 return when converting an unwritten extent 3893 * unless m_len is 0 (bug) or extent has been corrupted 3894 */ 3895 if (unlikely(ret == 0)) { 3896 EXT4_ERROR_INODE(inode, "unexpected ret == 0, m_len = %u", 3897 map->m_len); 3898 err = -EFSCORRUPTED; 3899 goto out2; 3900 } 3901 3902 out: 3903 allocated = ret; 3904 map->m_flags |= EXT4_MAP_NEW; 3905 map_out: 3906 map->m_flags |= EXT4_MAP_MAPPED; 3907 out1: 3908 map->m_pblk = newblock; 3909 if (allocated > map->m_len) 3910 allocated = map->m_len; 3911 map->m_len = allocated; 3912 ext4_ext_show_leaf(inode, path); 3913 out2: 3914 return err ? err : allocated; 3915 } 3916 3917 /* 3918 * get_implied_cluster_alloc - check to see if the requested 3919 * allocation (in the map structure) overlaps with a cluster already 3920 * allocated in an extent. 3921 * @sb The filesystem superblock structure 3922 * @map The requested lblk->pblk mapping 3923 * @ex The extent structure which might contain an implied 3924 * cluster allocation 3925 * 3926 * This function is called by ext4_ext_map_blocks() after we failed to 3927 * find blocks that were already in the inode's extent tree. Hence, 3928 * we know that the beginning of the requested region cannot overlap 3929 * the extent from the inode's extent tree. There are three cases we 3930 * want to catch. The first is this case: 3931 * 3932 * |--- cluster # N--| 3933 * |--- extent ---| |---- requested region ---| 3934 * |==========| 3935 * 3936 * The second case that we need to test for is this one: 3937 * 3938 * |--------- cluster # N ----------------| 3939 * |--- requested region --| |------- extent ----| 3940 * |=======================| 3941 * 3942 * The third case is when the requested region lies between two extents 3943 * within the same cluster: 3944 * |------------- cluster # N-------------| 3945 * |----- ex -----| |---- ex_right ----| 3946 * |------ requested region ------| 3947 * |================| 3948 * 3949 * In each of the above cases, we need to set the map->m_pblk and 3950 * map->m_len so it corresponds to the return the extent labelled as 3951 * "|====|" from cluster #N, since it is already in use for data in 3952 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to 3953 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated 3954 * as a new "allocated" block region. Otherwise, we will return 0 and 3955 * ext4_ext_map_blocks() will then allocate one or more new clusters 3956 * by calling ext4_mb_new_blocks(). 3957 */ 3958 static int get_implied_cluster_alloc(struct super_block *sb, 3959 struct ext4_map_blocks *map, 3960 struct ext4_extent *ex, 3961 struct ext4_ext_path *path) 3962 { 3963 struct ext4_sb_info *sbi = EXT4_SB(sb); 3964 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk); 3965 ext4_lblk_t ex_cluster_start, ex_cluster_end; 3966 ext4_lblk_t rr_cluster_start; 3967 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); 3968 ext4_fsblk_t ee_start = ext4_ext_pblock(ex); 3969 unsigned short ee_len = ext4_ext_get_actual_len(ex); 3970 3971 /* The extent passed in that we are trying to match */ 3972 ex_cluster_start = EXT4_B2C(sbi, ee_block); 3973 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1); 3974 3975 /* The requested region passed into ext4_map_blocks() */ 3976 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk); 3977 3978 if ((rr_cluster_start == ex_cluster_end) || 3979 (rr_cluster_start == ex_cluster_start)) { 3980 if (rr_cluster_start == ex_cluster_end) 3981 ee_start += ee_len - 1; 3982 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset; 3983 map->m_len = min(map->m_len, 3984 (unsigned) sbi->s_cluster_ratio - c_offset); 3985 /* 3986 * Check for and handle this case: 3987 * 3988 * |--------- cluster # N-------------| 3989 * |------- extent ----| 3990 * |--- requested region ---| 3991 * |===========| 3992 */ 3993 3994 if (map->m_lblk < ee_block) 3995 map->m_len = min(map->m_len, ee_block - map->m_lblk); 3996 3997 /* 3998 * Check for the case where there is already another allocated 3999 * block to the right of 'ex' but before the end of the cluster. 4000 * 4001 * |------------- cluster # N-------------| 4002 * |----- ex -----| |---- ex_right ----| 4003 * |------ requested region ------| 4004 * |================| 4005 */ 4006 if (map->m_lblk > ee_block) { 4007 ext4_lblk_t next = ext4_ext_next_allocated_block(path); 4008 map->m_len = min(map->m_len, next - map->m_lblk); 4009 } 4010 4011 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1); 4012 return 1; 4013 } 4014 4015 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0); 4016 return 0; 4017 } 4018 4019 4020 /* 4021 * Block allocation/map/preallocation routine for extents based files 4022 * 4023 * 4024 * Need to be called with 4025 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block 4026 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) 4027 * 4028 * return > 0, number of blocks already mapped/allocated 4029 * if create == 0 and these are pre-allocated blocks 4030 * buffer head is unmapped 4031 * otherwise blocks are mapped 4032 * 4033 * return = 0, if plain look up failed (blocks have not been allocated) 4034 * buffer head is unmapped 4035 * 4036 * return < 0, error case. 4037 */ 4038 int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, 4039 struct ext4_map_blocks *map, int flags) 4040 { 4041 struct ext4_ext_path *path = NULL; 4042 struct ext4_extent newex, *ex, *ex2; 4043 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 4044 ext4_fsblk_t newblock = 0, pblk; 4045 int err = 0, depth, ret; 4046 unsigned int allocated = 0, offset = 0; 4047 unsigned int allocated_clusters = 0; 4048 struct ext4_allocation_request ar; 4049 ext4_lblk_t cluster_offset; 4050 4051 ext_debug(inode, "blocks %u/%u requested\n", map->m_lblk, map->m_len); 4052 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); 4053 4054 /* find extent for this block */ 4055 path = ext4_find_extent(inode, map->m_lblk, NULL, 0); 4056 if (IS_ERR(path)) { 4057 err = PTR_ERR(path); 4058 path = NULL; 4059 goto out; 4060 } 4061 4062 depth = ext_depth(inode); 4063 4064 /* 4065 * consistent leaf must not be empty; 4066 * this situation is possible, though, _during_ tree modification; 4067 * this is why assert can't be put in ext4_find_extent() 4068 */ 4069 if (unlikely(path[depth].p_ext == NULL && depth != 0)) { 4070 EXT4_ERROR_INODE(inode, "bad extent address " 4071 "lblock: %lu, depth: %d pblock %lld", 4072 (unsigned long) map->m_lblk, depth, 4073 path[depth].p_block); 4074 err = -EFSCORRUPTED; 4075 goto out; 4076 } 4077 4078 ex = path[depth].p_ext; 4079 if (ex) { 4080 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); 4081 ext4_fsblk_t ee_start = ext4_ext_pblock(ex); 4082 unsigned short ee_len; 4083 4084 4085 /* 4086 * unwritten extents are treated as holes, except that 4087 * we split out initialized portions during a write. 4088 */ 4089 ee_len = ext4_ext_get_actual_len(ex); 4090 4091 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len); 4092 4093 /* if found extent covers block, simply return it */ 4094 if (in_range(map->m_lblk, ee_block, ee_len)) { 4095 newblock = map->m_lblk - ee_block + ee_start; 4096 /* number of remaining blocks in the extent */ 4097 allocated = ee_len - (map->m_lblk - ee_block); 4098 ext_debug(inode, "%u fit into %u:%d -> %llu\n", 4099 map->m_lblk, ee_block, ee_len, newblock); 4100 4101 /* 4102 * If the extent is initialized check whether the 4103 * caller wants to convert it to unwritten. 4104 */ 4105 if ((!ext4_ext_is_unwritten(ex)) && 4106 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) { 4107 err = convert_initialized_extent(handle, 4108 inode, map, &path, &allocated); 4109 goto out; 4110 } else if (!ext4_ext_is_unwritten(ex)) { 4111 map->m_flags |= EXT4_MAP_MAPPED; 4112 map->m_pblk = newblock; 4113 if (allocated > map->m_len) 4114 allocated = map->m_len; 4115 map->m_len = allocated; 4116 ext4_ext_show_leaf(inode, path); 4117 goto out; 4118 } 4119 4120 ret = ext4_ext_handle_unwritten_extents( 4121 handle, inode, map, &path, flags, 4122 allocated, newblock); 4123 if (ret < 0) 4124 err = ret; 4125 else 4126 allocated = ret; 4127 goto out; 4128 } 4129 } 4130 4131 /* 4132 * requested block isn't allocated yet; 4133 * we couldn't try to create block if create flag is zero 4134 */ 4135 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { 4136 ext4_lblk_t hole_start, hole_len; 4137 4138 hole_start = map->m_lblk; 4139 hole_len = ext4_ext_determine_hole(inode, path, &hole_start); 4140 /* 4141 * put just found gap into cache to speed up 4142 * subsequent requests 4143 */ 4144 ext4_ext_put_gap_in_cache(inode, hole_start, hole_len); 4145 4146 /* Update hole_len to reflect hole size after map->m_lblk */ 4147 if (hole_start != map->m_lblk) 4148 hole_len -= map->m_lblk - hole_start; 4149 map->m_pblk = 0; 4150 map->m_len = min_t(unsigned int, map->m_len, hole_len); 4151 4152 goto out; 4153 } 4154 4155 /* 4156 * Okay, we need to do block allocation. 4157 */ 4158 newex.ee_block = cpu_to_le32(map->m_lblk); 4159 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk); 4160 4161 /* 4162 * If we are doing bigalloc, check to see if the extent returned 4163 * by ext4_find_extent() implies a cluster we can use. 4164 */ 4165 if (cluster_offset && ex && 4166 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) { 4167 ar.len = allocated = map->m_len; 4168 newblock = map->m_pblk; 4169 goto got_allocated_blocks; 4170 } 4171 4172 /* find neighbour allocated blocks */ 4173 ar.lleft = map->m_lblk; 4174 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); 4175 if (err) 4176 goto out; 4177 ar.lright = map->m_lblk; 4178 ex2 = NULL; 4179 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2); 4180 if (err) 4181 goto out; 4182 4183 /* Check if the extent after searching to the right implies a 4184 * cluster we can use. */ 4185 if ((sbi->s_cluster_ratio > 1) && ex2 && 4186 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) { 4187 ar.len = allocated = map->m_len; 4188 newblock = map->m_pblk; 4189 goto got_allocated_blocks; 4190 } 4191 4192 /* 4193 * See if request is beyond maximum number of blocks we can have in 4194 * a single extent. For an initialized extent this limit is 4195 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is 4196 * EXT_UNWRITTEN_MAX_LEN. 4197 */ 4198 if (map->m_len > EXT_INIT_MAX_LEN && 4199 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT)) 4200 map->m_len = EXT_INIT_MAX_LEN; 4201 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN && 4202 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT)) 4203 map->m_len = EXT_UNWRITTEN_MAX_LEN; 4204 4205 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */ 4206 newex.ee_len = cpu_to_le16(map->m_len); 4207 err = ext4_ext_check_overlap(sbi, inode, &newex, path); 4208 if (err) 4209 allocated = ext4_ext_get_actual_len(&newex); 4210 else 4211 allocated = map->m_len; 4212 4213 /* allocate new block */ 4214 ar.inode = inode; 4215 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk); 4216 ar.logical = map->m_lblk; 4217 /* 4218 * We calculate the offset from the beginning of the cluster 4219 * for the logical block number, since when we allocate a 4220 * physical cluster, the physical block should start at the 4221 * same offset from the beginning of the cluster. This is 4222 * needed so that future calls to get_implied_cluster_alloc() 4223 * work correctly. 4224 */ 4225 offset = EXT4_LBLK_COFF(sbi, map->m_lblk); 4226 ar.len = EXT4_NUM_B2C(sbi, offset+allocated); 4227 ar.goal -= offset; 4228 ar.logical -= offset; 4229 if (S_ISREG(inode->i_mode)) 4230 ar.flags = EXT4_MB_HINT_DATA; 4231 else 4232 /* disable in-core preallocation for non-regular files */ 4233 ar.flags = 0; 4234 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE) 4235 ar.flags |= EXT4_MB_HINT_NOPREALLOC; 4236 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) 4237 ar.flags |= EXT4_MB_DELALLOC_RESERVED; 4238 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) 4239 ar.flags |= EXT4_MB_USE_RESERVED; 4240 newblock = ext4_mb_new_blocks(handle, &ar, &err); 4241 if (!newblock) 4242 goto out; 4243 allocated_clusters = ar.len; 4244 ar.len = EXT4_C2B(sbi, ar.len) - offset; 4245 ext_debug(inode, "allocate new block: goal %llu, found %llu/%u, requested %u\n", 4246 ar.goal, newblock, ar.len, allocated); 4247 if (ar.len > allocated) 4248 ar.len = allocated; 4249 4250 got_allocated_blocks: 4251 /* try to insert new extent into found leaf and return */ 4252 pblk = newblock + offset; 4253 ext4_ext_store_pblock(&newex, pblk); 4254 newex.ee_len = cpu_to_le16(ar.len); 4255 /* Mark unwritten */ 4256 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) { 4257 ext4_ext_mark_unwritten(&newex); 4258 map->m_flags |= EXT4_MAP_UNWRITTEN; 4259 } 4260 4261 err = ext4_ext_insert_extent(handle, inode, &path, &newex, flags); 4262 if (err) { 4263 if (allocated_clusters) { 4264 int fb_flags = 0; 4265 4266 /* 4267 * free data blocks we just allocated. 4268 * not a good idea to call discard here directly, 4269 * but otherwise we'd need to call it every free(). 4270 */ 4271 ext4_discard_preallocations(inode, 0); 4272 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) 4273 fb_flags = EXT4_FREE_BLOCKS_NO_QUOT_UPDATE; 4274 ext4_free_blocks(handle, inode, NULL, newblock, 4275 EXT4_C2B(sbi, allocated_clusters), 4276 fb_flags); 4277 } 4278 goto out; 4279 } 4280 4281 /* 4282 * Reduce the reserved cluster count to reflect successful deferred 4283 * allocation of delayed allocated clusters or direct allocation of 4284 * clusters discovered to be delayed allocated. Once allocated, a 4285 * cluster is not included in the reserved count. 4286 */ 4287 if (test_opt(inode->i_sb, DELALLOC) && allocated_clusters) { 4288 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { 4289 /* 4290 * When allocating delayed allocated clusters, simply 4291 * reduce the reserved cluster count and claim quota 4292 */ 4293 ext4_da_update_reserve_space(inode, allocated_clusters, 4294 1); 4295 } else { 4296 ext4_lblk_t lblk, len; 4297 unsigned int n; 4298 4299 /* 4300 * When allocating non-delayed allocated clusters 4301 * (from fallocate, filemap, DIO, or clusters 4302 * allocated when delalloc has been disabled by 4303 * ext4_nonda_switch), reduce the reserved cluster 4304 * count by the number of allocated clusters that 4305 * have previously been delayed allocated. Quota 4306 * has been claimed by ext4_mb_new_blocks() above, 4307 * so release the quota reservations made for any 4308 * previously delayed allocated clusters. 4309 */ 4310 lblk = EXT4_LBLK_CMASK(sbi, map->m_lblk); 4311 len = allocated_clusters << sbi->s_cluster_bits; 4312 n = ext4_es_delayed_clu(inode, lblk, len); 4313 if (n > 0) 4314 ext4_da_update_reserve_space(inode, (int) n, 0); 4315 } 4316 } 4317 4318 /* 4319 * Cache the extent and update transaction to commit on fdatasync only 4320 * when it is _not_ an unwritten extent. 4321 */ 4322 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0) 4323 ext4_update_inode_fsync_trans(handle, inode, 1); 4324 else 4325 ext4_update_inode_fsync_trans(handle, inode, 0); 4326 4327 map->m_flags |= (EXT4_MAP_NEW | EXT4_MAP_MAPPED); 4328 map->m_pblk = pblk; 4329 map->m_len = ar.len; 4330 allocated = map->m_len; 4331 ext4_ext_show_leaf(inode, path); 4332 ext4_fc_track_range(inode, map->m_lblk, map->m_lblk + map->m_len - 1); 4333 out: 4334 ext4_ext_drop_refs(path); 4335 kfree(path); 4336 4337 trace_ext4_ext_map_blocks_exit(inode, flags, map, 4338 err ? err : allocated); 4339 return err ? err : allocated; 4340 } 4341 4342 int ext4_ext_truncate(handle_t *handle, struct inode *inode) 4343 { 4344 struct super_block *sb = inode->i_sb; 4345 ext4_lblk_t last_block; 4346 int err = 0; 4347 4348 /* 4349 * TODO: optimization is possible here. 4350 * Probably we need not scan at all, 4351 * because page truncation is enough. 4352 */ 4353 4354 /* we have to know where to truncate from in crash case */ 4355 EXT4_I(inode)->i_disksize = inode->i_size; 4356 err = ext4_mark_inode_dirty(handle, inode); 4357 if (err) 4358 return err; 4359 4360 last_block = (inode->i_size + sb->s_blocksize - 1) 4361 >> EXT4_BLOCK_SIZE_BITS(sb); 4362 retry: 4363 err = ext4_es_remove_extent(inode, last_block, 4364 EXT_MAX_BLOCKS - last_block); 4365 if (err == -ENOMEM) { 4366 cond_resched(); 4367 congestion_wait(BLK_RW_ASYNC, HZ/50); 4368 goto retry; 4369 } 4370 if (err) 4371 return err; 4372 retry_remove_space: 4373 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1); 4374 if (err == -ENOMEM) { 4375 cond_resched(); 4376 congestion_wait(BLK_RW_ASYNC, HZ/50); 4377 goto retry_remove_space; 4378 } 4379 return err; 4380 } 4381 4382 static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset, 4383 ext4_lblk_t len, loff_t new_size, 4384 int flags) 4385 { 4386 struct inode *inode = file_inode(file); 4387 handle_t *handle; 4388 int ret = 0; 4389 int ret2 = 0, ret3 = 0; 4390 int retries = 0; 4391 int depth = 0; 4392 struct ext4_map_blocks map; 4393 unsigned int credits; 4394 loff_t epos; 4395 4396 BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)); 4397 map.m_lblk = offset; 4398 map.m_len = len; 4399 /* 4400 * Don't normalize the request if it can fit in one extent so 4401 * that it doesn't get unnecessarily split into multiple 4402 * extents. 4403 */ 4404 if (len <= EXT_UNWRITTEN_MAX_LEN) 4405 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE; 4406 4407 /* 4408 * credits to insert 1 extent into extent tree 4409 */ 4410 credits = ext4_chunk_trans_blocks(inode, len); 4411 depth = ext_depth(inode); 4412 4413 retry: 4414 while (ret >= 0 && len) { 4415 /* 4416 * Recalculate credits when extent tree depth changes. 4417 */ 4418 if (depth != ext_depth(inode)) { 4419 credits = ext4_chunk_trans_blocks(inode, len); 4420 depth = ext_depth(inode); 4421 } 4422 4423 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, 4424 credits); 4425 if (IS_ERR(handle)) { 4426 ret = PTR_ERR(handle); 4427 break; 4428 } 4429 ret = ext4_map_blocks(handle, inode, &map, flags); 4430 if (ret <= 0) { 4431 ext4_debug("inode #%lu: block %u: len %u: " 4432 "ext4_ext_map_blocks returned %d", 4433 inode->i_ino, map.m_lblk, 4434 map.m_len, ret); 4435 ext4_mark_inode_dirty(handle, inode); 4436 ret2 = ext4_journal_stop(handle); 4437 break; 4438 } 4439 map.m_lblk += ret; 4440 map.m_len = len = len - ret; 4441 epos = (loff_t)map.m_lblk << inode->i_blkbits; 4442 inode->i_ctime = current_time(inode); 4443 if (new_size) { 4444 if (epos > new_size) 4445 epos = new_size; 4446 if (ext4_update_inode_size(inode, epos) & 0x1) 4447 inode->i_mtime = inode->i_ctime; 4448 } 4449 ret2 = ext4_mark_inode_dirty(handle, inode); 4450 ext4_update_inode_fsync_trans(handle, inode, 1); 4451 ret3 = ext4_journal_stop(handle); 4452 ret2 = ret3 ? ret3 : ret2; 4453 if (unlikely(ret2)) 4454 break; 4455 } 4456 if (ret == -ENOSPC && 4457 ext4_should_retry_alloc(inode->i_sb, &retries)) { 4458 ret = 0; 4459 goto retry; 4460 } 4461 4462 return ret > 0 ? ret2 : ret; 4463 } 4464 4465 static int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len); 4466 4467 static int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len); 4468 4469 static long ext4_zero_range(struct file *file, loff_t offset, 4470 loff_t len, int mode) 4471 { 4472 struct inode *inode = file_inode(file); 4473 handle_t *handle = NULL; 4474 unsigned int max_blocks; 4475 loff_t new_size = 0; 4476 int ret = 0; 4477 int flags; 4478 int credits; 4479 int partial_begin, partial_end; 4480 loff_t start, end; 4481 ext4_lblk_t lblk; 4482 unsigned int blkbits = inode->i_blkbits; 4483 4484 trace_ext4_zero_range(inode, offset, len, mode); 4485 4486 /* Call ext4_force_commit to flush all data in case of data=journal. */ 4487 if (ext4_should_journal_data(inode)) { 4488 ret = ext4_force_commit(inode->i_sb); 4489 if (ret) 4490 return ret; 4491 } 4492 4493 /* 4494 * Round up offset. This is not fallocate, we need to zero out 4495 * blocks, so convert interior block aligned part of the range to 4496 * unwritten and possibly manually zero out unaligned parts of the 4497 * range. 4498 */ 4499 start = round_up(offset, 1 << blkbits); 4500 end = round_down((offset + len), 1 << blkbits); 4501 4502 if (start < offset || end > offset + len) 4503 return -EINVAL; 4504 partial_begin = offset & ((1 << blkbits) - 1); 4505 partial_end = (offset + len) & ((1 << blkbits) - 1); 4506 4507 lblk = start >> blkbits; 4508 max_blocks = (end >> blkbits); 4509 if (max_blocks < lblk) 4510 max_blocks = 0; 4511 else 4512 max_blocks -= lblk; 4513 4514 inode_lock(inode); 4515 4516 /* 4517 * Indirect files do not support unwritten extents 4518 */ 4519 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { 4520 ret = -EOPNOTSUPP; 4521 goto out_mutex; 4522 } 4523 4524 if (!(mode & FALLOC_FL_KEEP_SIZE) && 4525 (offset + len > inode->i_size || 4526 offset + len > EXT4_I(inode)->i_disksize)) { 4527 new_size = offset + len; 4528 ret = inode_newsize_ok(inode, new_size); 4529 if (ret) 4530 goto out_mutex; 4531 } 4532 4533 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT; 4534 4535 /* Wait all existing dio workers, newcomers will block on i_mutex */ 4536 inode_dio_wait(inode); 4537 4538 /* Preallocate the range including the unaligned edges */ 4539 if (partial_begin || partial_end) { 4540 ret = ext4_alloc_file_blocks(file, 4541 round_down(offset, 1 << blkbits) >> blkbits, 4542 (round_up((offset + len), 1 << blkbits) - 4543 round_down(offset, 1 << blkbits)) >> blkbits, 4544 new_size, flags); 4545 if (ret) 4546 goto out_mutex; 4547 4548 } 4549 4550 /* Zero range excluding the unaligned edges */ 4551 if (max_blocks > 0) { 4552 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN | 4553 EXT4_EX_NOCACHE); 4554 4555 /* 4556 * Prevent page faults from reinstantiating pages we have 4557 * released from page cache. 4558 */ 4559 down_write(&EXT4_I(inode)->i_mmap_sem); 4560 4561 ret = ext4_break_layouts(inode); 4562 if (ret) { 4563 up_write(&EXT4_I(inode)->i_mmap_sem); 4564 goto out_mutex; 4565 } 4566 4567 ret = ext4_update_disksize_before_punch(inode, offset, len); 4568 if (ret) { 4569 up_write(&EXT4_I(inode)->i_mmap_sem); 4570 goto out_mutex; 4571 } 4572 /* Now release the pages and zero block aligned part of pages */ 4573 truncate_pagecache_range(inode, start, end - 1); 4574 inode->i_mtime = inode->i_ctime = current_time(inode); 4575 4576 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, 4577 flags); 4578 up_write(&EXT4_I(inode)->i_mmap_sem); 4579 if (ret) 4580 goto out_mutex; 4581 } 4582 if (!partial_begin && !partial_end) 4583 goto out_mutex; 4584 4585 /* 4586 * In worst case we have to writeout two nonadjacent unwritten 4587 * blocks and update the inode 4588 */ 4589 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1; 4590 if (ext4_should_journal_data(inode)) 4591 credits += 2; 4592 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits); 4593 if (IS_ERR(handle)) { 4594 ret = PTR_ERR(handle); 4595 ext4_std_error(inode->i_sb, ret); 4596 goto out_mutex; 4597 } 4598 4599 inode->i_mtime = inode->i_ctime = current_time(inode); 4600 if (new_size) 4601 ext4_update_inode_size(inode, new_size); 4602 ret = ext4_mark_inode_dirty(handle, inode); 4603 if (unlikely(ret)) 4604 goto out_handle; 4605 ext4_fc_track_range(inode, offset >> inode->i_sb->s_blocksize_bits, 4606 (offset + len - 1) >> inode->i_sb->s_blocksize_bits); 4607 /* Zero out partial block at the edges of the range */ 4608 ret = ext4_zero_partial_blocks(handle, inode, offset, len); 4609 if (ret >= 0) 4610 ext4_update_inode_fsync_trans(handle, inode, 1); 4611 4612 if (file->f_flags & O_SYNC) 4613 ext4_handle_sync(handle); 4614 4615 out_handle: 4616 ext4_journal_stop(handle); 4617 out_mutex: 4618 inode_unlock(inode); 4619 return ret; 4620 } 4621 4622 /* 4623 * preallocate space for a file. This implements ext4's fallocate file 4624 * operation, which gets called from sys_fallocate system call. 4625 * For block-mapped files, posix_fallocate should fall back to the method 4626 * of writing zeroes to the required new blocks (the same behavior which is 4627 * expected for file systems which do not support fallocate() system call). 4628 */ 4629 long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) 4630 { 4631 struct inode *inode = file_inode(file); 4632 loff_t new_size = 0; 4633 unsigned int max_blocks; 4634 int ret = 0; 4635 int flags; 4636 ext4_lblk_t lblk; 4637 unsigned int blkbits = inode->i_blkbits; 4638 4639 /* 4640 * Encrypted inodes can't handle collapse range or insert 4641 * range since we would need to re-encrypt blocks with a 4642 * different IV or XTS tweak (which are based on the logical 4643 * block number). 4644 */ 4645 if (IS_ENCRYPTED(inode) && 4646 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE))) 4647 return -EOPNOTSUPP; 4648 4649 /* Return error if mode is not supported */ 4650 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | 4651 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | 4652 FALLOC_FL_INSERT_RANGE)) 4653 return -EOPNOTSUPP; 4654 ext4_fc_track_range(inode, offset >> blkbits, 4655 (offset + len - 1) >> blkbits); 4656 4657 ext4_fc_start_update(inode); 4658 4659 if (mode & FALLOC_FL_PUNCH_HOLE) { 4660 ret = ext4_punch_hole(inode, offset, len); 4661 goto exit; 4662 } 4663 4664 ret = ext4_convert_inline_data(inode); 4665 if (ret) 4666 goto exit; 4667 4668 if (mode & FALLOC_FL_COLLAPSE_RANGE) { 4669 ret = ext4_collapse_range(inode, offset, len); 4670 goto exit; 4671 } 4672 4673 if (mode & FALLOC_FL_INSERT_RANGE) { 4674 ret = ext4_insert_range(inode, offset, len); 4675 goto exit; 4676 } 4677 4678 if (mode & FALLOC_FL_ZERO_RANGE) { 4679 ret = ext4_zero_range(file, offset, len, mode); 4680 goto exit; 4681 } 4682 trace_ext4_fallocate_enter(inode, offset, len, mode); 4683 lblk = offset >> blkbits; 4684 4685 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits); 4686 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT; 4687 4688 inode_lock(inode); 4689 4690 /* 4691 * We only support preallocation for extent-based files only 4692 */ 4693 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { 4694 ret = -EOPNOTSUPP; 4695 goto out; 4696 } 4697 4698 if (!(mode & FALLOC_FL_KEEP_SIZE) && 4699 (offset + len > inode->i_size || 4700 offset + len > EXT4_I(inode)->i_disksize)) { 4701 new_size = offset + len; 4702 ret = inode_newsize_ok(inode, new_size); 4703 if (ret) 4704 goto out; 4705 } 4706 4707 /* Wait all existing dio workers, newcomers will block on i_mutex */ 4708 inode_dio_wait(inode); 4709 4710 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags); 4711 if (ret) 4712 goto out; 4713 4714 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) { 4715 ret = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal, 4716 EXT4_I(inode)->i_sync_tid); 4717 } 4718 out: 4719 inode_unlock(inode); 4720 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); 4721 exit: 4722 ext4_fc_stop_update(inode); 4723 return ret; 4724 } 4725 4726 /* 4727 * This function convert a range of blocks to written extents 4728 * The caller of this function will pass the start offset and the size. 4729 * all unwritten extents within this range will be converted to 4730 * written extents. 4731 * 4732 * This function is called from the direct IO end io call back 4733 * function, to convert the fallocated extents after IO is completed. 4734 * Returns 0 on success. 4735 */ 4736 int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode, 4737 loff_t offset, ssize_t len) 4738 { 4739 unsigned int max_blocks; 4740 int ret = 0, ret2 = 0, ret3 = 0; 4741 struct ext4_map_blocks map; 4742 unsigned int blkbits = inode->i_blkbits; 4743 unsigned int credits = 0; 4744 4745 map.m_lblk = offset >> blkbits; 4746 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits); 4747 4748 if (!handle) { 4749 /* 4750 * credits to insert 1 extent into extent tree 4751 */ 4752 credits = ext4_chunk_trans_blocks(inode, max_blocks); 4753 } 4754 while (ret >= 0 && ret < max_blocks) { 4755 map.m_lblk += ret; 4756 map.m_len = (max_blocks -= ret); 4757 if (credits) { 4758 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, 4759 credits); 4760 if (IS_ERR(handle)) { 4761 ret = PTR_ERR(handle); 4762 break; 4763 } 4764 } 4765 ret = ext4_map_blocks(handle, inode, &map, 4766 EXT4_GET_BLOCKS_IO_CONVERT_EXT); 4767 if (ret <= 0) 4768 ext4_warning(inode->i_sb, 4769 "inode #%lu: block %u: len %u: " 4770 "ext4_ext_map_blocks returned %d", 4771 inode->i_ino, map.m_lblk, 4772 map.m_len, ret); 4773 ret2 = ext4_mark_inode_dirty(handle, inode); 4774 if (credits) { 4775 ret3 = ext4_journal_stop(handle); 4776 if (unlikely(ret3)) 4777 ret2 = ret3; 4778 } 4779 4780 if (ret <= 0 || ret2) 4781 break; 4782 } 4783 return ret > 0 ? ret2 : ret; 4784 } 4785 4786 int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end) 4787 { 4788 int ret = 0, err = 0; 4789 struct ext4_io_end_vec *io_end_vec; 4790 4791 /* 4792 * This is somewhat ugly but the idea is clear: When transaction is 4793 * reserved, everything goes into it. Otherwise we rather start several 4794 * smaller transactions for conversion of each extent separately. 4795 */ 4796 if (handle) { 4797 handle = ext4_journal_start_reserved(handle, 4798 EXT4_HT_EXT_CONVERT); 4799 if (IS_ERR(handle)) 4800 return PTR_ERR(handle); 4801 } 4802 4803 list_for_each_entry(io_end_vec, &io_end->list_vec, list) { 4804 ret = ext4_convert_unwritten_extents(handle, io_end->inode, 4805 io_end_vec->offset, 4806 io_end_vec->size); 4807 if (ret) 4808 break; 4809 } 4810 4811 if (handle) 4812 err = ext4_journal_stop(handle); 4813 4814 return ret < 0 ? ret : err; 4815 } 4816 4817 static int ext4_iomap_xattr_fiemap(struct inode *inode, struct iomap *iomap) 4818 { 4819 __u64 physical = 0; 4820 __u64 length = 0; 4821 int blockbits = inode->i_sb->s_blocksize_bits; 4822 int error = 0; 4823 u16 iomap_type; 4824 4825 /* in-inode? */ 4826 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 4827 struct ext4_iloc iloc; 4828 int offset; /* offset of xattr in inode */ 4829 4830 error = ext4_get_inode_loc(inode, &iloc); 4831 if (error) 4832 return error; 4833 physical = (__u64)iloc.bh->b_blocknr << blockbits; 4834 offset = EXT4_GOOD_OLD_INODE_SIZE + 4835 EXT4_I(inode)->i_extra_isize; 4836 physical += offset; 4837 length = EXT4_SB(inode->i_sb)->s_inode_size - offset; 4838 brelse(iloc.bh); 4839 iomap_type = IOMAP_INLINE; 4840 } else if (EXT4_I(inode)->i_file_acl) { /* external block */ 4841 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits; 4842 length = inode->i_sb->s_blocksize; 4843 iomap_type = IOMAP_MAPPED; 4844 } else { 4845 /* no in-inode or external block for xattr, so return -ENOENT */ 4846 error = -ENOENT; 4847 goto out; 4848 } 4849 4850 iomap->addr = physical; 4851 iomap->offset = 0; 4852 iomap->length = length; 4853 iomap->type = iomap_type; 4854 iomap->flags = 0; 4855 out: 4856 return error; 4857 } 4858 4859 static int ext4_iomap_xattr_begin(struct inode *inode, loff_t offset, 4860 loff_t length, unsigned flags, 4861 struct iomap *iomap, struct iomap *srcmap) 4862 { 4863 int error; 4864 4865 error = ext4_iomap_xattr_fiemap(inode, iomap); 4866 if (error == 0 && (offset >= iomap->length)) 4867 error = -ENOENT; 4868 return error; 4869 } 4870 4871 static const struct iomap_ops ext4_iomap_xattr_ops = { 4872 .iomap_begin = ext4_iomap_xattr_begin, 4873 }; 4874 4875 static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len) 4876 { 4877 u64 maxbytes; 4878 4879 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) 4880 maxbytes = inode->i_sb->s_maxbytes; 4881 else 4882 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes; 4883 4884 if (*len == 0) 4885 return -EINVAL; 4886 if (start > maxbytes) 4887 return -EFBIG; 4888 4889 /* 4890 * Shrink request scope to what the fs can actually handle. 4891 */ 4892 if (*len > maxbytes || (maxbytes - *len) < start) 4893 *len = maxbytes - start; 4894 return 0; 4895 } 4896 4897 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 4898 u64 start, u64 len) 4899 { 4900 int error = 0; 4901 4902 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) { 4903 error = ext4_ext_precache(inode); 4904 if (error) 4905 return error; 4906 fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE; 4907 } 4908 4909 /* 4910 * For bitmap files the maximum size limit could be smaller than 4911 * s_maxbytes, so check len here manually instead of just relying on the 4912 * generic check. 4913 */ 4914 error = ext4_fiemap_check_ranges(inode, start, &len); 4915 if (error) 4916 return error; 4917 4918 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { 4919 fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR; 4920 return iomap_fiemap(inode, fieinfo, start, len, 4921 &ext4_iomap_xattr_ops); 4922 } 4923 4924 return iomap_fiemap(inode, fieinfo, start, len, &ext4_iomap_report_ops); 4925 } 4926 4927 int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo, 4928 __u64 start, __u64 len) 4929 { 4930 ext4_lblk_t start_blk, len_blks; 4931 __u64 last_blk; 4932 int error = 0; 4933 4934 if (ext4_has_inline_data(inode)) { 4935 int has_inline; 4936 4937 down_read(&EXT4_I(inode)->xattr_sem); 4938 has_inline = ext4_has_inline_data(inode); 4939 up_read(&EXT4_I(inode)->xattr_sem); 4940 if (has_inline) 4941 return 0; 4942 } 4943 4944 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) { 4945 error = ext4_ext_precache(inode); 4946 if (error) 4947 return error; 4948 fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE; 4949 } 4950 4951 error = fiemap_prep(inode, fieinfo, start, &len, 0); 4952 if (error) 4953 return error; 4954 4955 error = ext4_fiemap_check_ranges(inode, start, &len); 4956 if (error) 4957 return error; 4958 4959 start_blk = start >> inode->i_sb->s_blocksize_bits; 4960 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits; 4961 if (last_blk >= EXT_MAX_BLOCKS) 4962 last_blk = EXT_MAX_BLOCKS-1; 4963 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1; 4964 4965 /* 4966 * Walk the extent tree gathering extent information 4967 * and pushing extents back to the user. 4968 */ 4969 return ext4_fill_es_cache_info(inode, start_blk, len_blks, fieinfo); 4970 } 4971 4972 /* 4973 * ext4_access_path: 4974 * Function to access the path buffer for marking it dirty. 4975 * It also checks if there are sufficient credits left in the journal handle 4976 * to update path. 4977 */ 4978 static int 4979 ext4_access_path(handle_t *handle, struct inode *inode, 4980 struct ext4_ext_path *path) 4981 { 4982 int credits, err; 4983 4984 if (!ext4_handle_valid(handle)) 4985 return 0; 4986 4987 /* 4988 * Check if need to extend journal credits 4989 * 3 for leaf, sb, and inode plus 2 (bmap and group 4990 * descriptor) for each block group; assume two block 4991 * groups 4992 */ 4993 credits = ext4_writepage_trans_blocks(inode); 4994 err = ext4_datasem_ensure_credits(handle, inode, 7, credits, 0); 4995 if (err < 0) 4996 return err; 4997 4998 err = ext4_ext_get_access(handle, inode, path); 4999 return err; 5000 } 5001 5002 /* 5003 * ext4_ext_shift_path_extents: 5004 * Shift the extents of a path structure lying between path[depth].p_ext 5005 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells 5006 * if it is right shift or left shift operation. 5007 */ 5008 static int 5009 ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift, 5010 struct inode *inode, handle_t *handle, 5011 enum SHIFT_DIRECTION SHIFT) 5012 { 5013 int depth, err = 0; 5014 struct ext4_extent *ex_start, *ex_last; 5015 bool update = false; 5016 depth = path->p_depth; 5017 5018 while (depth >= 0) { 5019 if (depth == path->p_depth) { 5020 ex_start = path[depth].p_ext; 5021 if (!ex_start) 5022 return -EFSCORRUPTED; 5023 5024 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr); 5025 5026 err = ext4_access_path(handle, inode, path + depth); 5027 if (err) 5028 goto out; 5029 5030 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) 5031 update = true; 5032 5033 while (ex_start <= ex_last) { 5034 if (SHIFT == SHIFT_LEFT) { 5035 le32_add_cpu(&ex_start->ee_block, 5036 -shift); 5037 /* Try to merge to the left. */ 5038 if ((ex_start > 5039 EXT_FIRST_EXTENT(path[depth].p_hdr)) 5040 && 5041 ext4_ext_try_to_merge_right(inode, 5042 path, ex_start - 1)) 5043 ex_last--; 5044 else 5045 ex_start++; 5046 } else { 5047 le32_add_cpu(&ex_last->ee_block, shift); 5048 ext4_ext_try_to_merge_right(inode, path, 5049 ex_last); 5050 ex_last--; 5051 } 5052 } 5053 err = ext4_ext_dirty(handle, inode, path + depth); 5054 if (err) 5055 goto out; 5056 5057 if (--depth < 0 || !update) 5058 break; 5059 } 5060 5061 /* Update index too */ 5062 err = ext4_access_path(handle, inode, path + depth); 5063 if (err) 5064 goto out; 5065 5066 if (SHIFT == SHIFT_LEFT) 5067 le32_add_cpu(&path[depth].p_idx->ei_block, -shift); 5068 else 5069 le32_add_cpu(&path[depth].p_idx->ei_block, shift); 5070 err = ext4_ext_dirty(handle, inode, path + depth); 5071 if (err) 5072 goto out; 5073 5074 /* we are done if current index is not a starting index */ 5075 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr)) 5076 break; 5077 5078 depth--; 5079 } 5080 5081 out: 5082 return err; 5083 } 5084 5085 /* 5086 * ext4_ext_shift_extents: 5087 * All the extents which lies in the range from @start to the last allocated 5088 * block for the @inode are shifted either towards left or right (depending 5089 * upon @SHIFT) by @shift blocks. 5090 * On success, 0 is returned, error otherwise. 5091 */ 5092 static int 5093 ext4_ext_shift_extents(struct inode *inode, handle_t *handle, 5094 ext4_lblk_t start, ext4_lblk_t shift, 5095 enum SHIFT_DIRECTION SHIFT) 5096 { 5097 struct ext4_ext_path *path; 5098 int ret = 0, depth; 5099 struct ext4_extent *extent; 5100 ext4_lblk_t stop, *iterator, ex_start, ex_end; 5101 5102 /* Let path point to the last extent */ 5103 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 5104 EXT4_EX_NOCACHE); 5105 if (IS_ERR(path)) 5106 return PTR_ERR(path); 5107 5108 depth = path->p_depth; 5109 extent = path[depth].p_ext; 5110 if (!extent) 5111 goto out; 5112 5113 stop = le32_to_cpu(extent->ee_block); 5114 5115 /* 5116 * For left shifts, make sure the hole on the left is big enough to 5117 * accommodate the shift. For right shifts, make sure the last extent 5118 * won't be shifted beyond EXT_MAX_BLOCKS. 5119 */ 5120 if (SHIFT == SHIFT_LEFT) { 5121 path = ext4_find_extent(inode, start - 1, &path, 5122 EXT4_EX_NOCACHE); 5123 if (IS_ERR(path)) 5124 return PTR_ERR(path); 5125 depth = path->p_depth; 5126 extent = path[depth].p_ext; 5127 if (extent) { 5128 ex_start = le32_to_cpu(extent->ee_block); 5129 ex_end = le32_to_cpu(extent->ee_block) + 5130 ext4_ext_get_actual_len(extent); 5131 } else { 5132 ex_start = 0; 5133 ex_end = 0; 5134 } 5135 5136 if ((start == ex_start && shift > ex_start) || 5137 (shift > start - ex_end)) { 5138 ret = -EINVAL; 5139 goto out; 5140 } 5141 } else { 5142 if (shift > EXT_MAX_BLOCKS - 5143 (stop + ext4_ext_get_actual_len(extent))) { 5144 ret = -EINVAL; 5145 goto out; 5146 } 5147 } 5148 5149 /* 5150 * In case of left shift, iterator points to start and it is increased 5151 * till we reach stop. In case of right shift, iterator points to stop 5152 * and it is decreased till we reach start. 5153 */ 5154 if (SHIFT == SHIFT_LEFT) 5155 iterator = &start; 5156 else 5157 iterator = &stop; 5158 5159 /* 5160 * Its safe to start updating extents. Start and stop are unsigned, so 5161 * in case of right shift if extent with 0 block is reached, iterator 5162 * becomes NULL to indicate the end of the loop. 5163 */ 5164 while (iterator && start <= stop) { 5165 path = ext4_find_extent(inode, *iterator, &path, 5166 EXT4_EX_NOCACHE); 5167 if (IS_ERR(path)) 5168 return PTR_ERR(path); 5169 depth = path->p_depth; 5170 extent = path[depth].p_ext; 5171 if (!extent) { 5172 EXT4_ERROR_INODE(inode, "unexpected hole at %lu", 5173 (unsigned long) *iterator); 5174 return -EFSCORRUPTED; 5175 } 5176 if (SHIFT == SHIFT_LEFT && *iterator > 5177 le32_to_cpu(extent->ee_block)) { 5178 /* Hole, move to the next extent */ 5179 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) { 5180 path[depth].p_ext++; 5181 } else { 5182 *iterator = ext4_ext_next_allocated_block(path); 5183 continue; 5184 } 5185 } 5186 5187 if (SHIFT == SHIFT_LEFT) { 5188 extent = EXT_LAST_EXTENT(path[depth].p_hdr); 5189 *iterator = le32_to_cpu(extent->ee_block) + 5190 ext4_ext_get_actual_len(extent); 5191 } else { 5192 extent = EXT_FIRST_EXTENT(path[depth].p_hdr); 5193 if (le32_to_cpu(extent->ee_block) > 0) 5194 *iterator = le32_to_cpu(extent->ee_block) - 1; 5195 else 5196 /* Beginning is reached, end of the loop */ 5197 iterator = NULL; 5198 /* Update path extent in case we need to stop */ 5199 while (le32_to_cpu(extent->ee_block) < start) 5200 extent++; 5201 path[depth].p_ext = extent; 5202 } 5203 ret = ext4_ext_shift_path_extents(path, shift, inode, 5204 handle, SHIFT); 5205 if (ret) 5206 break; 5207 } 5208 out: 5209 ext4_ext_drop_refs(path); 5210 kfree(path); 5211 return ret; 5212 } 5213 5214 /* 5215 * ext4_collapse_range: 5216 * This implements the fallocate's collapse range functionality for ext4 5217 * Returns: 0 and non-zero on error. 5218 */ 5219 static int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) 5220 { 5221 struct super_block *sb = inode->i_sb; 5222 ext4_lblk_t punch_start, punch_stop; 5223 handle_t *handle; 5224 unsigned int credits; 5225 loff_t new_size, ioffset; 5226 int ret; 5227 5228 /* 5229 * We need to test this early because xfstests assumes that a 5230 * collapse range of (0, 1) will return EOPNOTSUPP if the file 5231 * system does not support collapse range. 5232 */ 5233 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) 5234 return -EOPNOTSUPP; 5235 5236 /* Collapse range works only on fs cluster size aligned regions. */ 5237 if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) 5238 return -EINVAL; 5239 5240 trace_ext4_collapse_range(inode, offset, len); 5241 5242 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb); 5243 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb); 5244 5245 /* Call ext4_force_commit to flush all data in case of data=journal. */ 5246 if (ext4_should_journal_data(inode)) { 5247 ret = ext4_force_commit(inode->i_sb); 5248 if (ret) 5249 return ret; 5250 } 5251 5252 inode_lock(inode); 5253 /* 5254 * There is no need to overlap collapse range with EOF, in which case 5255 * it is effectively a truncate operation 5256 */ 5257 if (offset + len >= inode->i_size) { 5258 ret = -EINVAL; 5259 goto out_mutex; 5260 } 5261 5262 /* Currently just for extent based files */ 5263 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { 5264 ret = -EOPNOTSUPP; 5265 goto out_mutex; 5266 } 5267 5268 /* Wait for existing dio to complete */ 5269 inode_dio_wait(inode); 5270 5271 /* 5272 * Prevent page faults from reinstantiating pages we have released from 5273 * page cache. 5274 */ 5275 down_write(&EXT4_I(inode)->i_mmap_sem); 5276 5277 ret = ext4_break_layouts(inode); 5278 if (ret) 5279 goto out_mmap; 5280 5281 /* 5282 * Need to round down offset to be aligned with page size boundary 5283 * for page size > block size. 5284 */ 5285 ioffset = round_down(offset, PAGE_SIZE); 5286 /* 5287 * Write tail of the last page before removed range since it will get 5288 * removed from the page cache below. 5289 */ 5290 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, offset); 5291 if (ret) 5292 goto out_mmap; 5293 /* 5294 * Write data that will be shifted to preserve them when discarding 5295 * page cache below. We are also protected from pages becoming dirty 5296 * by i_mmap_sem. 5297 */ 5298 ret = filemap_write_and_wait_range(inode->i_mapping, offset + len, 5299 LLONG_MAX); 5300 if (ret) 5301 goto out_mmap; 5302 truncate_pagecache(inode, ioffset); 5303 5304 credits = ext4_writepage_trans_blocks(inode); 5305 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); 5306 if (IS_ERR(handle)) { 5307 ret = PTR_ERR(handle); 5308 goto out_mmap; 5309 } 5310 ext4_fc_start_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE); 5311 5312 down_write(&EXT4_I(inode)->i_data_sem); 5313 ext4_discard_preallocations(inode, 0); 5314 5315 ret = ext4_es_remove_extent(inode, punch_start, 5316 EXT_MAX_BLOCKS - punch_start); 5317 if (ret) { 5318 up_write(&EXT4_I(inode)->i_data_sem); 5319 goto out_stop; 5320 } 5321 5322 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1); 5323 if (ret) { 5324 up_write(&EXT4_I(inode)->i_data_sem); 5325 goto out_stop; 5326 } 5327 ext4_discard_preallocations(inode, 0); 5328 5329 ret = ext4_ext_shift_extents(inode, handle, punch_stop, 5330 punch_stop - punch_start, SHIFT_LEFT); 5331 if (ret) { 5332 up_write(&EXT4_I(inode)->i_data_sem); 5333 goto out_stop; 5334 } 5335 5336 new_size = inode->i_size - len; 5337 i_size_write(inode, new_size); 5338 EXT4_I(inode)->i_disksize = new_size; 5339 5340 up_write(&EXT4_I(inode)->i_data_sem); 5341 if (IS_SYNC(inode)) 5342 ext4_handle_sync(handle); 5343 inode->i_mtime = inode->i_ctime = current_time(inode); 5344 ret = ext4_mark_inode_dirty(handle, inode); 5345 ext4_update_inode_fsync_trans(handle, inode, 1); 5346 5347 out_stop: 5348 ext4_journal_stop(handle); 5349 ext4_fc_stop_ineligible(sb); 5350 out_mmap: 5351 up_write(&EXT4_I(inode)->i_mmap_sem); 5352 out_mutex: 5353 inode_unlock(inode); 5354 return ret; 5355 } 5356 5357 /* 5358 * ext4_insert_range: 5359 * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate. 5360 * The data blocks starting from @offset to the EOF are shifted by @len 5361 * towards right to create a hole in the @inode. Inode size is increased 5362 * by len bytes. 5363 * Returns 0 on success, error otherwise. 5364 */ 5365 static int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len) 5366 { 5367 struct super_block *sb = inode->i_sb; 5368 handle_t *handle; 5369 struct ext4_ext_path *path; 5370 struct ext4_extent *extent; 5371 ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0; 5372 unsigned int credits, ee_len; 5373 int ret = 0, depth, split_flag = 0; 5374 loff_t ioffset; 5375 5376 /* 5377 * We need to test this early because xfstests assumes that an 5378 * insert range of (0, 1) will return EOPNOTSUPP if the file 5379 * system does not support insert range. 5380 */ 5381 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) 5382 return -EOPNOTSUPP; 5383 5384 /* Insert range works only on fs cluster size aligned regions. */ 5385 if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) 5386 return -EINVAL; 5387 5388 trace_ext4_insert_range(inode, offset, len); 5389 5390 offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb); 5391 len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb); 5392 5393 /* Call ext4_force_commit to flush all data in case of data=journal */ 5394 if (ext4_should_journal_data(inode)) { 5395 ret = ext4_force_commit(inode->i_sb); 5396 if (ret) 5397 return ret; 5398 } 5399 5400 inode_lock(inode); 5401 /* Currently just for extent based files */ 5402 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { 5403 ret = -EOPNOTSUPP; 5404 goto out_mutex; 5405 } 5406 5407 /* Check whether the maximum file size would be exceeded */ 5408 if (len > inode->i_sb->s_maxbytes - inode->i_size) { 5409 ret = -EFBIG; 5410 goto out_mutex; 5411 } 5412 5413 /* Offset must be less than i_size */ 5414 if (offset >= inode->i_size) { 5415 ret = -EINVAL; 5416 goto out_mutex; 5417 } 5418 5419 /* Wait for existing dio to complete */ 5420 inode_dio_wait(inode); 5421 5422 /* 5423 * Prevent page faults from reinstantiating pages we have released from 5424 * page cache. 5425 */ 5426 down_write(&EXT4_I(inode)->i_mmap_sem); 5427 5428 ret = ext4_break_layouts(inode); 5429 if (ret) 5430 goto out_mmap; 5431 5432 /* 5433 * Need to round down to align start offset to page size boundary 5434 * for page size > block size. 5435 */ 5436 ioffset = round_down(offset, PAGE_SIZE); 5437 /* Write out all dirty pages */ 5438 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, 5439 LLONG_MAX); 5440 if (ret) 5441 goto out_mmap; 5442 truncate_pagecache(inode, ioffset); 5443 5444 credits = ext4_writepage_trans_blocks(inode); 5445 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); 5446 if (IS_ERR(handle)) { 5447 ret = PTR_ERR(handle); 5448 goto out_mmap; 5449 } 5450 ext4_fc_start_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE); 5451 5452 /* Expand file to avoid data loss if there is error while shifting */ 5453 inode->i_size += len; 5454 EXT4_I(inode)->i_disksize += len; 5455 inode->i_mtime = inode->i_ctime = current_time(inode); 5456 ret = ext4_mark_inode_dirty(handle, inode); 5457 if (ret) 5458 goto out_stop; 5459 5460 down_write(&EXT4_I(inode)->i_data_sem); 5461 ext4_discard_preallocations(inode, 0); 5462 5463 path = ext4_find_extent(inode, offset_lblk, NULL, 0); 5464 if (IS_ERR(path)) { 5465 up_write(&EXT4_I(inode)->i_data_sem); 5466 goto out_stop; 5467 } 5468 5469 depth = ext_depth(inode); 5470 extent = path[depth].p_ext; 5471 if (extent) { 5472 ee_start_lblk = le32_to_cpu(extent->ee_block); 5473 ee_len = ext4_ext_get_actual_len(extent); 5474 5475 /* 5476 * If offset_lblk is not the starting block of extent, split 5477 * the extent @offset_lblk 5478 */ 5479 if ((offset_lblk > ee_start_lblk) && 5480 (offset_lblk < (ee_start_lblk + ee_len))) { 5481 if (ext4_ext_is_unwritten(extent)) 5482 split_flag = EXT4_EXT_MARK_UNWRIT1 | 5483 EXT4_EXT_MARK_UNWRIT2; 5484 ret = ext4_split_extent_at(handle, inode, &path, 5485 offset_lblk, split_flag, 5486 EXT4_EX_NOCACHE | 5487 EXT4_GET_BLOCKS_PRE_IO | 5488 EXT4_GET_BLOCKS_METADATA_NOFAIL); 5489 } 5490 5491 ext4_ext_drop_refs(path); 5492 kfree(path); 5493 if (ret < 0) { 5494 up_write(&EXT4_I(inode)->i_data_sem); 5495 goto out_stop; 5496 } 5497 } else { 5498 ext4_ext_drop_refs(path); 5499 kfree(path); 5500 } 5501 5502 ret = ext4_es_remove_extent(inode, offset_lblk, 5503 EXT_MAX_BLOCKS - offset_lblk); 5504 if (ret) { 5505 up_write(&EXT4_I(inode)->i_data_sem); 5506 goto out_stop; 5507 } 5508 5509 /* 5510 * if offset_lblk lies in a hole which is at start of file, use 5511 * ee_start_lblk to shift extents 5512 */ 5513 ret = ext4_ext_shift_extents(inode, handle, 5514 ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk, 5515 len_lblk, SHIFT_RIGHT); 5516 5517 up_write(&EXT4_I(inode)->i_data_sem); 5518 if (IS_SYNC(inode)) 5519 ext4_handle_sync(handle); 5520 if (ret >= 0) 5521 ext4_update_inode_fsync_trans(handle, inode, 1); 5522 5523 out_stop: 5524 ext4_journal_stop(handle); 5525 ext4_fc_stop_ineligible(sb); 5526 out_mmap: 5527 up_write(&EXT4_I(inode)->i_mmap_sem); 5528 out_mutex: 5529 inode_unlock(inode); 5530 return ret; 5531 } 5532 5533 /** 5534 * ext4_swap_extents() - Swap extents between two inodes 5535 * @handle: handle for this transaction 5536 * @inode1: First inode 5537 * @inode2: Second inode 5538 * @lblk1: Start block for first inode 5539 * @lblk2: Start block for second inode 5540 * @count: Number of blocks to swap 5541 * @unwritten: Mark second inode's extents as unwritten after swap 5542 * @erp: Pointer to save error value 5543 * 5544 * This helper routine does exactly what is promise "swap extents". All other 5545 * stuff such as page-cache locking consistency, bh mapping consistency or 5546 * extent's data copying must be performed by caller. 5547 * Locking: 5548 * i_mutex is held for both inodes 5549 * i_data_sem is locked for write for both inodes 5550 * Assumptions: 5551 * All pages from requested range are locked for both inodes 5552 */ 5553 int 5554 ext4_swap_extents(handle_t *handle, struct inode *inode1, 5555 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2, 5556 ext4_lblk_t count, int unwritten, int *erp) 5557 { 5558 struct ext4_ext_path *path1 = NULL; 5559 struct ext4_ext_path *path2 = NULL; 5560 int replaced_count = 0; 5561 5562 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem)); 5563 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem)); 5564 BUG_ON(!inode_is_locked(inode1)); 5565 BUG_ON(!inode_is_locked(inode2)); 5566 5567 *erp = ext4_es_remove_extent(inode1, lblk1, count); 5568 if (unlikely(*erp)) 5569 return 0; 5570 *erp = ext4_es_remove_extent(inode2, lblk2, count); 5571 if (unlikely(*erp)) 5572 return 0; 5573 5574 while (count) { 5575 struct ext4_extent *ex1, *ex2, tmp_ex; 5576 ext4_lblk_t e1_blk, e2_blk; 5577 int e1_len, e2_len, len; 5578 int split = 0; 5579 5580 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE); 5581 if (IS_ERR(path1)) { 5582 *erp = PTR_ERR(path1); 5583 path1 = NULL; 5584 finish: 5585 count = 0; 5586 goto repeat; 5587 } 5588 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE); 5589 if (IS_ERR(path2)) { 5590 *erp = PTR_ERR(path2); 5591 path2 = NULL; 5592 goto finish; 5593 } 5594 ex1 = path1[path1->p_depth].p_ext; 5595 ex2 = path2[path2->p_depth].p_ext; 5596 /* Do we have something to swap ? */ 5597 if (unlikely(!ex2 || !ex1)) 5598 goto finish; 5599 5600 e1_blk = le32_to_cpu(ex1->ee_block); 5601 e2_blk = le32_to_cpu(ex2->ee_block); 5602 e1_len = ext4_ext_get_actual_len(ex1); 5603 e2_len = ext4_ext_get_actual_len(ex2); 5604 5605 /* Hole handling */ 5606 if (!in_range(lblk1, e1_blk, e1_len) || 5607 !in_range(lblk2, e2_blk, e2_len)) { 5608 ext4_lblk_t next1, next2; 5609 5610 /* if hole after extent, then go to next extent */ 5611 next1 = ext4_ext_next_allocated_block(path1); 5612 next2 = ext4_ext_next_allocated_block(path2); 5613 /* If hole before extent, then shift to that extent */ 5614 if (e1_blk > lblk1) 5615 next1 = e1_blk; 5616 if (e2_blk > lblk2) 5617 next2 = e2_blk; 5618 /* Do we have something to swap */ 5619 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS) 5620 goto finish; 5621 /* Move to the rightest boundary */ 5622 len = next1 - lblk1; 5623 if (len < next2 - lblk2) 5624 len = next2 - lblk2; 5625 if (len > count) 5626 len = count; 5627 lblk1 += len; 5628 lblk2 += len; 5629 count -= len; 5630 goto repeat; 5631 } 5632 5633 /* Prepare left boundary */ 5634 if (e1_blk < lblk1) { 5635 split = 1; 5636 *erp = ext4_force_split_extent_at(handle, inode1, 5637 &path1, lblk1, 0); 5638 if (unlikely(*erp)) 5639 goto finish; 5640 } 5641 if (e2_blk < lblk2) { 5642 split = 1; 5643 *erp = ext4_force_split_extent_at(handle, inode2, 5644 &path2, lblk2, 0); 5645 if (unlikely(*erp)) 5646 goto finish; 5647 } 5648 /* ext4_split_extent_at() may result in leaf extent split, 5649 * path must to be revalidated. */ 5650 if (split) 5651 goto repeat; 5652 5653 /* Prepare right boundary */ 5654 len = count; 5655 if (len > e1_blk + e1_len - lblk1) 5656 len = e1_blk + e1_len - lblk1; 5657 if (len > e2_blk + e2_len - lblk2) 5658 len = e2_blk + e2_len - lblk2; 5659 5660 if (len != e1_len) { 5661 split = 1; 5662 *erp = ext4_force_split_extent_at(handle, inode1, 5663 &path1, lblk1 + len, 0); 5664 if (unlikely(*erp)) 5665 goto finish; 5666 } 5667 if (len != e2_len) { 5668 split = 1; 5669 *erp = ext4_force_split_extent_at(handle, inode2, 5670 &path2, lblk2 + len, 0); 5671 if (*erp) 5672 goto finish; 5673 } 5674 /* ext4_split_extent_at() may result in leaf extent split, 5675 * path must to be revalidated. */ 5676 if (split) 5677 goto repeat; 5678 5679 BUG_ON(e2_len != e1_len); 5680 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth); 5681 if (unlikely(*erp)) 5682 goto finish; 5683 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth); 5684 if (unlikely(*erp)) 5685 goto finish; 5686 5687 /* Both extents are fully inside boundaries. Swap it now */ 5688 tmp_ex = *ex1; 5689 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2)); 5690 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex)); 5691 ex1->ee_len = cpu_to_le16(e2_len); 5692 ex2->ee_len = cpu_to_le16(e1_len); 5693 if (unwritten) 5694 ext4_ext_mark_unwritten(ex2); 5695 if (ext4_ext_is_unwritten(&tmp_ex)) 5696 ext4_ext_mark_unwritten(ex1); 5697 5698 ext4_ext_try_to_merge(handle, inode2, path2, ex2); 5699 ext4_ext_try_to_merge(handle, inode1, path1, ex1); 5700 *erp = ext4_ext_dirty(handle, inode2, path2 + 5701 path2->p_depth); 5702 if (unlikely(*erp)) 5703 goto finish; 5704 *erp = ext4_ext_dirty(handle, inode1, path1 + 5705 path1->p_depth); 5706 /* 5707 * Looks scarry ah..? second inode already points to new blocks, 5708 * and it was successfully dirtied. But luckily error may happen 5709 * only due to journal error, so full transaction will be 5710 * aborted anyway. 5711 */ 5712 if (unlikely(*erp)) 5713 goto finish; 5714 lblk1 += len; 5715 lblk2 += len; 5716 replaced_count += len; 5717 count -= len; 5718 5719 repeat: 5720 ext4_ext_drop_refs(path1); 5721 kfree(path1); 5722 ext4_ext_drop_refs(path2); 5723 kfree(path2); 5724 path1 = path2 = NULL; 5725 } 5726 return replaced_count; 5727 } 5728 5729 /* 5730 * ext4_clu_mapped - determine whether any block in a logical cluster has 5731 * been mapped to a physical cluster 5732 * 5733 * @inode - file containing the logical cluster 5734 * @lclu - logical cluster of interest 5735 * 5736 * Returns 1 if any block in the logical cluster is mapped, signifying 5737 * that a physical cluster has been allocated for it. Otherwise, 5738 * returns 0. Can also return negative error codes. Derived from 5739 * ext4_ext_map_blocks(). 5740 */ 5741 int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu) 5742 { 5743 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 5744 struct ext4_ext_path *path; 5745 int depth, mapped = 0, err = 0; 5746 struct ext4_extent *extent; 5747 ext4_lblk_t first_lblk, first_lclu, last_lclu; 5748 5749 /* search for the extent closest to the first block in the cluster */ 5750 path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0); 5751 if (IS_ERR(path)) { 5752 err = PTR_ERR(path); 5753 path = NULL; 5754 goto out; 5755 } 5756 5757 depth = ext_depth(inode); 5758 5759 /* 5760 * A consistent leaf must not be empty. This situation is possible, 5761 * though, _during_ tree modification, and it's why an assert can't 5762 * be put in ext4_find_extent(). 5763 */ 5764 if (unlikely(path[depth].p_ext == NULL && depth != 0)) { 5765 EXT4_ERROR_INODE(inode, 5766 "bad extent address - lblock: %lu, depth: %d, pblock: %lld", 5767 (unsigned long) EXT4_C2B(sbi, lclu), 5768 depth, path[depth].p_block); 5769 err = -EFSCORRUPTED; 5770 goto out; 5771 } 5772 5773 extent = path[depth].p_ext; 5774 5775 /* can't be mapped if the extent tree is empty */ 5776 if (extent == NULL) 5777 goto out; 5778 5779 first_lblk = le32_to_cpu(extent->ee_block); 5780 first_lclu = EXT4_B2C(sbi, first_lblk); 5781 5782 /* 5783 * Three possible outcomes at this point - found extent spanning 5784 * the target cluster, to the left of the target cluster, or to the 5785 * right of the target cluster. The first two cases are handled here. 5786 * The last case indicates the target cluster is not mapped. 5787 */ 5788 if (lclu >= first_lclu) { 5789 last_lclu = EXT4_B2C(sbi, first_lblk + 5790 ext4_ext_get_actual_len(extent) - 1); 5791 if (lclu <= last_lclu) { 5792 mapped = 1; 5793 } else { 5794 first_lblk = ext4_ext_next_allocated_block(path); 5795 first_lclu = EXT4_B2C(sbi, first_lblk); 5796 if (lclu == first_lclu) 5797 mapped = 1; 5798 } 5799 } 5800 5801 out: 5802 ext4_ext_drop_refs(path); 5803 kfree(path); 5804 5805 return err ? err : mapped; 5806 } 5807 5808 /* 5809 * Updates physical block address and unwritten status of extent 5810 * starting at lblk start and of len. If such an extent doesn't exist, 5811 * this function splits the extent tree appropriately to create an 5812 * extent like this. This function is called in the fast commit 5813 * replay path. Returns 0 on success and error on failure. 5814 */ 5815 int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start, 5816 int len, int unwritten, ext4_fsblk_t pblk) 5817 { 5818 struct ext4_ext_path *path = NULL, *ppath; 5819 struct ext4_extent *ex; 5820 int ret; 5821 5822 path = ext4_find_extent(inode, start, NULL, 0); 5823 if (!path) 5824 return -EINVAL; 5825 ex = path[path->p_depth].p_ext; 5826 if (!ex) { 5827 ret = -EFSCORRUPTED; 5828 goto out; 5829 } 5830 5831 if (le32_to_cpu(ex->ee_block) != start || 5832 ext4_ext_get_actual_len(ex) != len) { 5833 /* We need to split this extent to match our extent first */ 5834 ppath = path; 5835 down_write(&EXT4_I(inode)->i_data_sem); 5836 ret = ext4_force_split_extent_at(NULL, inode, &ppath, start, 1); 5837 up_write(&EXT4_I(inode)->i_data_sem); 5838 if (ret) 5839 goto out; 5840 kfree(path); 5841 path = ext4_find_extent(inode, start, NULL, 0); 5842 if (IS_ERR(path)) 5843 return -1; 5844 ppath = path; 5845 ex = path[path->p_depth].p_ext; 5846 WARN_ON(le32_to_cpu(ex->ee_block) != start); 5847 if (ext4_ext_get_actual_len(ex) != len) { 5848 down_write(&EXT4_I(inode)->i_data_sem); 5849 ret = ext4_force_split_extent_at(NULL, inode, &ppath, 5850 start + len, 1); 5851 up_write(&EXT4_I(inode)->i_data_sem); 5852 if (ret) 5853 goto out; 5854 kfree(path); 5855 path = ext4_find_extent(inode, start, NULL, 0); 5856 if (IS_ERR(path)) 5857 return -EINVAL; 5858 ex = path[path->p_depth].p_ext; 5859 } 5860 } 5861 if (unwritten) 5862 ext4_ext_mark_unwritten(ex); 5863 else 5864 ext4_ext_mark_initialized(ex); 5865 ext4_ext_store_pblock(ex, pblk); 5866 down_write(&EXT4_I(inode)->i_data_sem); 5867 ret = ext4_ext_dirty(NULL, inode, &path[path->p_depth]); 5868 up_write(&EXT4_I(inode)->i_data_sem); 5869 out: 5870 ext4_ext_drop_refs(path); 5871 kfree(path); 5872 ext4_mark_inode_dirty(NULL, inode); 5873 return ret; 5874 } 5875 5876 /* Try to shrink the extent tree */ 5877 void ext4_ext_replay_shrink_inode(struct inode *inode, ext4_lblk_t end) 5878 { 5879 struct ext4_ext_path *path = NULL; 5880 struct ext4_extent *ex; 5881 ext4_lblk_t old_cur, cur = 0; 5882 5883 while (cur < end) { 5884 path = ext4_find_extent(inode, cur, NULL, 0); 5885 if (IS_ERR(path)) 5886 return; 5887 ex = path[path->p_depth].p_ext; 5888 if (!ex) { 5889 ext4_ext_drop_refs(path); 5890 kfree(path); 5891 ext4_mark_inode_dirty(NULL, inode); 5892 return; 5893 } 5894 old_cur = cur; 5895 cur = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); 5896 if (cur <= old_cur) 5897 cur = old_cur + 1; 5898 ext4_ext_try_to_merge(NULL, inode, path, ex); 5899 down_write(&EXT4_I(inode)->i_data_sem); 5900 ext4_ext_dirty(NULL, inode, &path[path->p_depth]); 5901 up_write(&EXT4_I(inode)->i_data_sem); 5902 ext4_mark_inode_dirty(NULL, inode); 5903 ext4_ext_drop_refs(path); 5904 kfree(path); 5905 } 5906 } 5907 5908 /* Check if *cur is a hole and if it is, skip it */ 5909 static void skip_hole(struct inode *inode, ext4_lblk_t *cur) 5910 { 5911 int ret; 5912 struct ext4_map_blocks map; 5913 5914 map.m_lblk = *cur; 5915 map.m_len = ((inode->i_size) >> inode->i_sb->s_blocksize_bits) - *cur; 5916 5917 ret = ext4_map_blocks(NULL, inode, &map, 0); 5918 if (ret != 0) 5919 return; 5920 *cur = *cur + map.m_len; 5921 } 5922 5923 /* Count number of blocks used by this inode and update i_blocks */ 5924 int ext4_ext_replay_set_iblocks(struct inode *inode) 5925 { 5926 struct ext4_ext_path *path = NULL, *path2 = NULL; 5927 struct ext4_extent *ex; 5928 ext4_lblk_t cur = 0, end; 5929 int numblks = 0, i, ret = 0; 5930 ext4_fsblk_t cmp1, cmp2; 5931 struct ext4_map_blocks map; 5932 5933 /* Determin the size of the file first */ 5934 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 5935 EXT4_EX_NOCACHE); 5936 if (IS_ERR(path)) 5937 return PTR_ERR(path); 5938 ex = path[path->p_depth].p_ext; 5939 if (!ex) { 5940 ext4_ext_drop_refs(path); 5941 kfree(path); 5942 goto out; 5943 } 5944 end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); 5945 ext4_ext_drop_refs(path); 5946 kfree(path); 5947 5948 /* Count the number of data blocks */ 5949 cur = 0; 5950 while (cur < end) { 5951 map.m_lblk = cur; 5952 map.m_len = end - cur; 5953 ret = ext4_map_blocks(NULL, inode, &map, 0); 5954 if (ret < 0) 5955 break; 5956 if (ret > 0) 5957 numblks += ret; 5958 cur = cur + map.m_len; 5959 } 5960 5961 /* 5962 * Count the number of extent tree blocks. We do it by looking up 5963 * two successive extents and determining the difference between 5964 * their paths. When path is different for 2 successive extents 5965 * we compare the blocks in the path at each level and increment 5966 * iblocks by total number of differences found. 5967 */ 5968 cur = 0; 5969 skip_hole(inode, &cur); 5970 path = ext4_find_extent(inode, cur, NULL, 0); 5971 if (IS_ERR(path)) 5972 goto out; 5973 numblks += path->p_depth; 5974 ext4_ext_drop_refs(path); 5975 kfree(path); 5976 while (cur < end) { 5977 path = ext4_find_extent(inode, cur, NULL, 0); 5978 if (IS_ERR(path)) 5979 break; 5980 ex = path[path->p_depth].p_ext; 5981 if (!ex) { 5982 ext4_ext_drop_refs(path); 5983 kfree(path); 5984 return 0; 5985 } 5986 cur = max(cur + 1, le32_to_cpu(ex->ee_block) + 5987 ext4_ext_get_actual_len(ex)); 5988 skip_hole(inode, &cur); 5989 5990 path2 = ext4_find_extent(inode, cur, NULL, 0); 5991 if (IS_ERR(path2)) { 5992 ext4_ext_drop_refs(path); 5993 kfree(path); 5994 break; 5995 } 5996 ex = path2[path2->p_depth].p_ext; 5997 for (i = 0; i <= max(path->p_depth, path2->p_depth); i++) { 5998 cmp1 = cmp2 = 0; 5999 if (i <= path->p_depth) 6000 cmp1 = path[i].p_bh ? 6001 path[i].p_bh->b_blocknr : 0; 6002 if (i <= path2->p_depth) 6003 cmp2 = path2[i].p_bh ? 6004 path2[i].p_bh->b_blocknr : 0; 6005 if (cmp1 != cmp2 && cmp2 != 0) 6006 numblks++; 6007 } 6008 ext4_ext_drop_refs(path); 6009 ext4_ext_drop_refs(path2); 6010 kfree(path); 6011 kfree(path2); 6012 } 6013 6014 out: 6015 inode->i_blocks = numblks << (inode->i_sb->s_blocksize_bits - 9); 6016 ext4_mark_inode_dirty(NULL, inode); 6017 return 0; 6018 } 6019 6020 int ext4_ext_clear_bb(struct inode *inode) 6021 { 6022 struct ext4_ext_path *path = NULL; 6023 struct ext4_extent *ex; 6024 ext4_lblk_t cur = 0, end; 6025 int j, ret = 0; 6026 struct ext4_map_blocks map; 6027 6028 /* Determin the size of the file first */ 6029 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 6030 EXT4_EX_NOCACHE); 6031 if (IS_ERR(path)) 6032 return PTR_ERR(path); 6033 ex = path[path->p_depth].p_ext; 6034 if (!ex) { 6035 ext4_ext_drop_refs(path); 6036 kfree(path); 6037 return 0; 6038 } 6039 end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); 6040 ext4_ext_drop_refs(path); 6041 kfree(path); 6042 6043 cur = 0; 6044 while (cur < end) { 6045 map.m_lblk = cur; 6046 map.m_len = end - cur; 6047 ret = ext4_map_blocks(NULL, inode, &map, 0); 6048 if (ret < 0) 6049 break; 6050 if (ret > 0) { 6051 path = ext4_find_extent(inode, map.m_lblk, NULL, 0); 6052 if (!IS_ERR_OR_NULL(path)) { 6053 for (j = 0; j < path->p_depth; j++) { 6054 6055 ext4_mb_mark_bb(inode->i_sb, 6056 path[j].p_block, 1, 0); 6057 } 6058 ext4_ext_drop_refs(path); 6059 kfree(path); 6060 } 6061 ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, 0); 6062 } 6063 cur = cur + map.m_len; 6064 } 6065 6066 return 0; 6067 } 6068