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 "ext4_jbd2.h" 32 #include "ext4_extents.h" 33 #include "xattr.h" 34 35 #include <trace/events/ext4.h> 36 37 /* 38 * used by extent splitting. 39 */ 40 #define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \ 41 due to ENOSPC */ 42 #define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */ 43 #define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */ 44 45 #define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */ 46 #define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */ 47 48 static __le32 ext4_extent_block_csum(struct inode *inode, 49 struct ext4_extent_header *eh) 50 { 51 struct ext4_inode_info *ei = EXT4_I(inode); 52 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 53 __u32 csum; 54 55 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh, 56 EXT4_EXTENT_TAIL_OFFSET(eh)); 57 return cpu_to_le32(csum); 58 } 59 60 static int ext4_extent_block_csum_verify(struct inode *inode, 61 struct ext4_extent_header *eh) 62 { 63 struct ext4_extent_tail *et; 64 65 if (!ext4_has_metadata_csum(inode->i_sb)) 66 return 1; 67 68 et = find_ext4_extent_tail(eh); 69 if (et->et_checksum != ext4_extent_block_csum(inode, eh)) 70 return 0; 71 return 1; 72 } 73 74 static void ext4_extent_block_csum_set(struct inode *inode, 75 struct ext4_extent_header *eh) 76 { 77 struct ext4_extent_tail *et; 78 79 if (!ext4_has_metadata_csum(inode->i_sb)) 80 return; 81 82 et = find_ext4_extent_tail(eh); 83 et->et_checksum = ext4_extent_block_csum(inode, eh); 84 } 85 86 static int ext4_split_extent(handle_t *handle, 87 struct inode *inode, 88 struct ext4_ext_path **ppath, 89 struct ext4_map_blocks *map, 90 int split_flag, 91 int flags); 92 93 static int ext4_split_extent_at(handle_t *handle, 94 struct inode *inode, 95 struct ext4_ext_path **ppath, 96 ext4_lblk_t split, 97 int split_flag, 98 int flags); 99 100 static int ext4_find_delayed_extent(struct inode *inode, 101 struct extent_status *newes); 102 103 static int ext4_ext_truncate_extend_restart(handle_t *handle, 104 struct inode *inode, 105 int needed) 106 { 107 int err; 108 109 if (!ext4_handle_valid(handle)) 110 return 0; 111 if (handle->h_buffer_credits >= needed) 112 return 0; 113 /* 114 * If we need to extend the journal get a few extra blocks 115 * while we're at it for efficiency's sake. 116 */ 117 needed += 3; 118 err = ext4_journal_extend(handle, needed - handle->h_buffer_credits); 119 if (err <= 0) 120 return err; 121 err = ext4_truncate_restart_trans(handle, inode, needed); 122 if (err == 0) 123 err = -EAGAIN; 124 125 return err; 126 } 127 128 /* 129 * could return: 130 * - EROFS 131 * - ENOMEM 132 */ 133 static int ext4_ext_get_access(handle_t *handle, struct inode *inode, 134 struct ext4_ext_path *path) 135 { 136 if (path->p_bh) { 137 /* path points to block */ 138 BUFFER_TRACE(path->p_bh, "get_write_access"); 139 return ext4_journal_get_write_access(handle, path->p_bh); 140 } 141 /* path points to leaf/index in inode body */ 142 /* we use in-core data, no need to protect them */ 143 return 0; 144 } 145 146 /* 147 * could return: 148 * - EROFS 149 * - ENOMEM 150 * - EIO 151 */ 152 int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle, 153 struct inode *inode, struct ext4_ext_path *path) 154 { 155 int err; 156 157 WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem)); 158 if (path->p_bh) { 159 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh)); 160 /* path points to block */ 161 err = __ext4_handle_dirty_metadata(where, line, handle, 162 inode, path->p_bh); 163 } else { 164 /* path points to leaf/index in inode body */ 165 err = ext4_mark_inode_dirty(handle, inode); 166 } 167 return err; 168 } 169 170 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, 171 struct ext4_ext_path *path, 172 ext4_lblk_t block) 173 { 174 if (path) { 175 int depth = path->p_depth; 176 struct ext4_extent *ex; 177 178 /* 179 * Try to predict block placement assuming that we are 180 * filling in a file which will eventually be 181 * non-sparse --- i.e., in the case of libbfd writing 182 * an ELF object sections out-of-order but in a way 183 * the eventually results in a contiguous object or 184 * executable file, or some database extending a table 185 * space file. However, this is actually somewhat 186 * non-ideal if we are writing a sparse file such as 187 * qemu or KVM writing a raw image file that is going 188 * to stay fairly sparse, since it will end up 189 * fragmenting the file system's free space. Maybe we 190 * should have some hueristics or some way to allow 191 * userspace to pass a hint to file system, 192 * especially if the latter case turns out to be 193 * common. 194 */ 195 ex = path[depth].p_ext; 196 if (ex) { 197 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex); 198 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block); 199 200 if (block > ext_block) 201 return ext_pblk + (block - ext_block); 202 else 203 return ext_pblk - (ext_block - block); 204 } 205 206 /* it looks like index is empty; 207 * try to find starting block from index itself */ 208 if (path[depth].p_bh) 209 return path[depth].p_bh->b_blocknr; 210 } 211 212 /* OK. use inode's group */ 213 return ext4_inode_to_goal_block(inode); 214 } 215 216 /* 217 * Allocation for a meta data block 218 */ 219 static ext4_fsblk_t 220 ext4_ext_new_meta_block(handle_t *handle, struct inode *inode, 221 struct ext4_ext_path *path, 222 struct ext4_extent *ex, int *err, unsigned int flags) 223 { 224 ext4_fsblk_t goal, newblock; 225 226 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); 227 newblock = ext4_new_meta_blocks(handle, inode, goal, flags, 228 NULL, err); 229 return newblock; 230 } 231 232 static inline int ext4_ext_space_block(struct inode *inode, int check) 233 { 234 int size; 235 236 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 237 / sizeof(struct ext4_extent); 238 #ifdef AGGRESSIVE_TEST 239 if (!check && size > 6) 240 size = 6; 241 #endif 242 return size; 243 } 244 245 static inline int ext4_ext_space_block_idx(struct inode *inode, int check) 246 { 247 int size; 248 249 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 250 / sizeof(struct ext4_extent_idx); 251 #ifdef AGGRESSIVE_TEST 252 if (!check && size > 5) 253 size = 5; 254 #endif 255 return size; 256 } 257 258 static inline int ext4_ext_space_root(struct inode *inode, int check) 259 { 260 int size; 261 262 size = sizeof(EXT4_I(inode)->i_data); 263 size -= sizeof(struct ext4_extent_header); 264 size /= sizeof(struct ext4_extent); 265 #ifdef AGGRESSIVE_TEST 266 if (!check && size > 3) 267 size = 3; 268 #endif 269 return size; 270 } 271 272 static inline int ext4_ext_space_root_idx(struct inode *inode, int check) 273 { 274 int size; 275 276 size = sizeof(EXT4_I(inode)->i_data); 277 size -= sizeof(struct ext4_extent_header); 278 size /= sizeof(struct ext4_extent_idx); 279 #ifdef AGGRESSIVE_TEST 280 if (!check && size > 4) 281 size = 4; 282 #endif 283 return size; 284 } 285 286 static inline int 287 ext4_force_split_extent_at(handle_t *handle, struct inode *inode, 288 struct ext4_ext_path **ppath, ext4_lblk_t lblk, 289 int nofail) 290 { 291 struct ext4_ext_path *path = *ppath; 292 int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext); 293 294 return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ? 295 EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0, 296 EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO | 297 (nofail ? EXT4_GET_BLOCKS_METADATA_NOFAIL:0)); 298 } 299 300 /* 301 * Calculate the number of metadata blocks needed 302 * to allocate @blocks 303 * Worse case is one block per extent 304 */ 305 int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock) 306 { 307 struct ext4_inode_info *ei = EXT4_I(inode); 308 int idxs; 309 310 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) 311 / sizeof(struct ext4_extent_idx)); 312 313 /* 314 * If the new delayed allocation block is contiguous with the 315 * previous da block, it can share index blocks with the 316 * previous block, so we only need to allocate a new index 317 * block every idxs leaf blocks. At ldxs**2 blocks, we need 318 * an additional index block, and at ldxs**3 blocks, yet 319 * another index blocks. 320 */ 321 if (ei->i_da_metadata_calc_len && 322 ei->i_da_metadata_calc_last_lblock+1 == lblock) { 323 int num = 0; 324 325 if ((ei->i_da_metadata_calc_len % idxs) == 0) 326 num++; 327 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0) 328 num++; 329 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) { 330 num++; 331 ei->i_da_metadata_calc_len = 0; 332 } else 333 ei->i_da_metadata_calc_len++; 334 ei->i_da_metadata_calc_last_lblock++; 335 return num; 336 } 337 338 /* 339 * In the worst case we need a new set of index blocks at 340 * every level of the inode's extent tree. 341 */ 342 ei->i_da_metadata_calc_len = 1; 343 ei->i_da_metadata_calc_last_lblock = lblock; 344 return ext_depth(inode) + 1; 345 } 346 347 static int 348 ext4_ext_max_entries(struct inode *inode, int depth) 349 { 350 int max; 351 352 if (depth == ext_depth(inode)) { 353 if (depth == 0) 354 max = ext4_ext_space_root(inode, 1); 355 else 356 max = ext4_ext_space_root_idx(inode, 1); 357 } else { 358 if (depth == 0) 359 max = ext4_ext_space_block(inode, 1); 360 else 361 max = ext4_ext_space_block_idx(inode, 1); 362 } 363 364 return max; 365 } 366 367 static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) 368 { 369 ext4_fsblk_t block = ext4_ext_pblock(ext); 370 int len = ext4_ext_get_actual_len(ext); 371 ext4_lblk_t lblock = le32_to_cpu(ext->ee_block); 372 373 /* 374 * We allow neither: 375 * - zero length 376 * - overflow/wrap-around 377 */ 378 if (lblock + len <= lblock) 379 return 0; 380 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); 381 } 382 383 static int ext4_valid_extent_idx(struct inode *inode, 384 struct ext4_extent_idx *ext_idx) 385 { 386 ext4_fsblk_t block = ext4_idx_pblock(ext_idx); 387 388 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1); 389 } 390 391 static int ext4_valid_extent_entries(struct inode *inode, 392 struct ext4_extent_header *eh, 393 int depth) 394 { 395 unsigned short entries; 396 if (eh->eh_entries == 0) 397 return 1; 398 399 entries = le16_to_cpu(eh->eh_entries); 400 401 if (depth == 0) { 402 /* leaf entries */ 403 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh); 404 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; 405 ext4_fsblk_t pblock = 0; 406 ext4_lblk_t lblock = 0; 407 ext4_lblk_t prev = 0; 408 int len = 0; 409 while (entries) { 410 if (!ext4_valid_extent(inode, ext)) 411 return 0; 412 413 /* Check for overlapping extents */ 414 lblock = le32_to_cpu(ext->ee_block); 415 len = ext4_ext_get_actual_len(ext); 416 if ((lblock <= prev) && prev) { 417 pblock = ext4_ext_pblock(ext); 418 es->s_last_error_block = cpu_to_le64(pblock); 419 return 0; 420 } 421 ext++; 422 entries--; 423 prev = lblock + len - 1; 424 } 425 } else { 426 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh); 427 while (entries) { 428 if (!ext4_valid_extent_idx(inode, ext_idx)) 429 return 0; 430 ext_idx++; 431 entries--; 432 } 433 } 434 return 1; 435 } 436 437 static int __ext4_ext_check(const char *function, unsigned int line, 438 struct inode *inode, struct ext4_extent_header *eh, 439 int depth, ext4_fsblk_t pblk) 440 { 441 const char *error_msg; 442 int max = 0, err = -EFSCORRUPTED; 443 444 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { 445 error_msg = "invalid magic"; 446 goto corrupted; 447 } 448 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { 449 error_msg = "unexpected eh_depth"; 450 goto corrupted; 451 } 452 if (unlikely(eh->eh_max == 0)) { 453 error_msg = "invalid eh_max"; 454 goto corrupted; 455 } 456 max = ext4_ext_max_entries(inode, depth); 457 if (unlikely(le16_to_cpu(eh->eh_max) > max)) { 458 error_msg = "too large eh_max"; 459 goto corrupted; 460 } 461 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { 462 error_msg = "invalid eh_entries"; 463 goto corrupted; 464 } 465 if (!ext4_valid_extent_entries(inode, eh, depth)) { 466 error_msg = "invalid extent entries"; 467 goto corrupted; 468 } 469 if (unlikely(depth > 32)) { 470 error_msg = "too large eh_depth"; 471 goto corrupted; 472 } 473 /* Verify checksum on non-root extent tree nodes */ 474 if (ext_depth(inode) != depth && 475 !ext4_extent_block_csum_verify(inode, eh)) { 476 error_msg = "extent tree corrupted"; 477 err = -EFSBADCRC; 478 goto corrupted; 479 } 480 return 0; 481 482 corrupted: 483 ext4_error_inode(inode, function, line, 0, 484 "pblk %llu bad header/extent: %s - magic %x, " 485 "entries %u, max %u(%u), depth %u(%u)", 486 (unsigned long long) pblk, error_msg, 487 le16_to_cpu(eh->eh_magic), 488 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), 489 max, le16_to_cpu(eh->eh_depth), depth); 490 return err; 491 } 492 493 #define ext4_ext_check(inode, eh, depth, pblk) \ 494 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk)) 495 496 int ext4_ext_check_inode(struct inode *inode) 497 { 498 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0); 499 } 500 501 static struct buffer_head * 502 __read_extent_tree_block(const char *function, unsigned int line, 503 struct inode *inode, ext4_fsblk_t pblk, int depth, 504 int flags) 505 { 506 struct buffer_head *bh; 507 int err; 508 509 bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS); 510 if (unlikely(!bh)) 511 return ERR_PTR(-ENOMEM); 512 513 if (!bh_uptodate_or_lock(bh)) { 514 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_); 515 err = bh_submit_read(bh); 516 if (err < 0) 517 goto errout; 518 } 519 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE)) 520 return bh; 521 err = __ext4_ext_check(function, line, inode, 522 ext_block_hdr(bh), depth, pblk); 523 if (err) 524 goto errout; 525 set_buffer_verified(bh); 526 /* 527 * If this is a leaf block, cache all of its entries 528 */ 529 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) { 530 struct ext4_extent_header *eh = ext_block_hdr(bh); 531 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh); 532 ext4_lblk_t prev = 0; 533 int i; 534 535 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) { 536 unsigned int status = EXTENT_STATUS_WRITTEN; 537 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block); 538 int len = ext4_ext_get_actual_len(ex); 539 540 if (prev && (prev != lblk)) 541 ext4_es_cache_extent(inode, prev, 542 lblk - prev, ~0, 543 EXTENT_STATUS_HOLE); 544 545 if (ext4_ext_is_unwritten(ex)) 546 status = EXTENT_STATUS_UNWRITTEN; 547 ext4_es_cache_extent(inode, lblk, len, 548 ext4_ext_pblock(ex), status); 549 prev = lblk + len; 550 } 551 } 552 return bh; 553 errout: 554 put_bh(bh); 555 return ERR_PTR(err); 556 557 } 558 559 #define read_extent_tree_block(inode, pblk, depth, flags) \ 560 __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \ 561 (depth), (flags)) 562 563 /* 564 * This function is called to cache a file's extent information in the 565 * extent status tree 566 */ 567 int ext4_ext_precache(struct inode *inode) 568 { 569 struct ext4_inode_info *ei = EXT4_I(inode); 570 struct ext4_ext_path *path = NULL; 571 struct buffer_head *bh; 572 int i = 0, depth, ret = 0; 573 574 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) 575 return 0; /* not an extent-mapped inode */ 576 577 down_read(&ei->i_data_sem); 578 depth = ext_depth(inode); 579 580 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path), 581 GFP_NOFS); 582 if (path == NULL) { 583 up_read(&ei->i_data_sem); 584 return -ENOMEM; 585 } 586 587 /* Don't cache anything if there are no external extent blocks */ 588 if (depth == 0) 589 goto out; 590 path[0].p_hdr = ext_inode_hdr(inode); 591 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0); 592 if (ret) 593 goto out; 594 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr); 595 while (i >= 0) { 596 /* 597 * If this is a leaf block or we've reached the end of 598 * the index block, go up 599 */ 600 if ((i == depth) || 601 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) { 602 brelse(path[i].p_bh); 603 path[i].p_bh = NULL; 604 i--; 605 continue; 606 } 607 bh = read_extent_tree_block(inode, 608 ext4_idx_pblock(path[i].p_idx++), 609 depth - i - 1, 610 EXT4_EX_FORCE_CACHE); 611 if (IS_ERR(bh)) { 612 ret = PTR_ERR(bh); 613 break; 614 } 615 i++; 616 path[i].p_bh = bh; 617 path[i].p_hdr = ext_block_hdr(bh); 618 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr); 619 } 620 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED); 621 out: 622 up_read(&ei->i_data_sem); 623 ext4_ext_drop_refs(path); 624 kfree(path); 625 return ret; 626 } 627 628 #ifdef EXT_DEBUG 629 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) 630 { 631 int k, l = path->p_depth; 632 633 ext_debug("path:"); 634 for (k = 0; k <= l; k++, path++) { 635 if (path->p_idx) { 636 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), 637 ext4_idx_pblock(path->p_idx)); 638 } else if (path->p_ext) { 639 ext_debug(" %d:[%d]%d:%llu ", 640 le32_to_cpu(path->p_ext->ee_block), 641 ext4_ext_is_unwritten(path->p_ext), 642 ext4_ext_get_actual_len(path->p_ext), 643 ext4_ext_pblock(path->p_ext)); 644 } else 645 ext_debug(" []"); 646 } 647 ext_debug("\n"); 648 } 649 650 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) 651 { 652 int depth = ext_depth(inode); 653 struct ext4_extent_header *eh; 654 struct ext4_extent *ex; 655 int i; 656 657 if (!path) 658 return; 659 660 eh = path[depth].p_hdr; 661 ex = EXT_FIRST_EXTENT(eh); 662 663 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino); 664 665 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { 666 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block), 667 ext4_ext_is_unwritten(ex), 668 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); 669 } 670 ext_debug("\n"); 671 } 672 673 static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path, 674 ext4_fsblk_t newblock, int level) 675 { 676 int depth = ext_depth(inode); 677 struct ext4_extent *ex; 678 679 if (depth != level) { 680 struct ext4_extent_idx *idx; 681 idx = path[level].p_idx; 682 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) { 683 ext_debug("%d: move %d:%llu in new index %llu\n", level, 684 le32_to_cpu(idx->ei_block), 685 ext4_idx_pblock(idx), 686 newblock); 687 idx++; 688 } 689 690 return; 691 } 692 693 ex = path[depth].p_ext; 694 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) { 695 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n", 696 le32_to_cpu(ex->ee_block), 697 ext4_ext_pblock(ex), 698 ext4_ext_is_unwritten(ex), 699 ext4_ext_get_actual_len(ex), 700 newblock); 701 ex++; 702 } 703 } 704 705 #else 706 #define ext4_ext_show_path(inode, path) 707 #define ext4_ext_show_leaf(inode, path) 708 #define ext4_ext_show_move(inode, path, newblock, level) 709 #endif 710 711 void ext4_ext_drop_refs(struct ext4_ext_path *path) 712 { 713 int depth, i; 714 715 if (!path) 716 return; 717 depth = path->p_depth; 718 for (i = 0; i <= depth; i++, path++) 719 if (path->p_bh) { 720 brelse(path->p_bh); 721 path->p_bh = NULL; 722 } 723 } 724 725 /* 726 * ext4_ext_binsearch_idx: 727 * binary search for the closest index of the given block 728 * the header must be checked before calling this 729 */ 730 static void 731 ext4_ext_binsearch_idx(struct inode *inode, 732 struct ext4_ext_path *path, ext4_lblk_t block) 733 { 734 struct ext4_extent_header *eh = path->p_hdr; 735 struct ext4_extent_idx *r, *l, *m; 736 737 738 ext_debug("binsearch for %u(idx): ", block); 739 740 l = EXT_FIRST_INDEX(eh) + 1; 741 r = EXT_LAST_INDEX(eh); 742 while (l <= r) { 743 m = l + (r - l) / 2; 744 if (block < le32_to_cpu(m->ei_block)) 745 r = m - 1; 746 else 747 l = m + 1; 748 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), 749 m, le32_to_cpu(m->ei_block), 750 r, le32_to_cpu(r->ei_block)); 751 } 752 753 path->p_idx = l - 1; 754 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block), 755 ext4_idx_pblock(path->p_idx)); 756 757 #ifdef CHECK_BINSEARCH 758 { 759 struct ext4_extent_idx *chix, *ix; 760 int k; 761 762 chix = ix = EXT_FIRST_INDEX(eh); 763 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { 764 if (k != 0 && 765 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { 766 printk(KERN_DEBUG "k=%d, ix=0x%p, " 767 "first=0x%p\n", k, 768 ix, EXT_FIRST_INDEX(eh)); 769 printk(KERN_DEBUG "%u <= %u\n", 770 le32_to_cpu(ix->ei_block), 771 le32_to_cpu(ix[-1].ei_block)); 772 } 773 BUG_ON(k && le32_to_cpu(ix->ei_block) 774 <= le32_to_cpu(ix[-1].ei_block)); 775 if (block < le32_to_cpu(ix->ei_block)) 776 break; 777 chix = ix; 778 } 779 BUG_ON(chix != path->p_idx); 780 } 781 #endif 782 783 } 784 785 /* 786 * ext4_ext_binsearch: 787 * binary search for closest extent of the given block 788 * the header must be checked before calling this 789 */ 790 static void 791 ext4_ext_binsearch(struct inode *inode, 792 struct ext4_ext_path *path, ext4_lblk_t block) 793 { 794 struct ext4_extent_header *eh = path->p_hdr; 795 struct ext4_extent *r, *l, *m; 796 797 if (eh->eh_entries == 0) { 798 /* 799 * this leaf is empty: 800 * we get such a leaf in split/add case 801 */ 802 return; 803 } 804 805 ext_debug("binsearch for %u: ", block); 806 807 l = EXT_FIRST_EXTENT(eh) + 1; 808 r = EXT_LAST_EXTENT(eh); 809 810 while (l <= r) { 811 m = l + (r - l) / 2; 812 if (block < le32_to_cpu(m->ee_block)) 813 r = m - 1; 814 else 815 l = m + 1; 816 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), 817 m, le32_to_cpu(m->ee_block), 818 r, le32_to_cpu(r->ee_block)); 819 } 820 821 path->p_ext = l - 1; 822 ext_debug(" -> %d:%llu:[%d]%d ", 823 le32_to_cpu(path->p_ext->ee_block), 824 ext4_ext_pblock(path->p_ext), 825 ext4_ext_is_unwritten(path->p_ext), 826 ext4_ext_get_actual_len(path->p_ext)); 827 828 #ifdef CHECK_BINSEARCH 829 { 830 struct ext4_extent *chex, *ex; 831 int k; 832 833 chex = ex = EXT_FIRST_EXTENT(eh); 834 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { 835 BUG_ON(k && le32_to_cpu(ex->ee_block) 836 <= le32_to_cpu(ex[-1].ee_block)); 837 if (block < le32_to_cpu(ex->ee_block)) 838 break; 839 chex = ex; 840 } 841 BUG_ON(chex != path->p_ext); 842 } 843 #endif 844 845 } 846 847 int ext4_ext_tree_init(handle_t *handle, struct inode *inode) 848 { 849 struct ext4_extent_header *eh; 850 851 eh = ext_inode_hdr(inode); 852 eh->eh_depth = 0; 853 eh->eh_entries = 0; 854 eh->eh_magic = EXT4_EXT_MAGIC; 855 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); 856 ext4_mark_inode_dirty(handle, inode); 857 return 0; 858 } 859 860 struct ext4_ext_path * 861 ext4_find_extent(struct inode *inode, ext4_lblk_t block, 862 struct ext4_ext_path **orig_path, int flags) 863 { 864 struct ext4_extent_header *eh; 865 struct buffer_head *bh; 866 struct ext4_ext_path *path = orig_path ? *orig_path : NULL; 867 short int depth, i, ppos = 0; 868 int ret; 869 870 eh = ext_inode_hdr(inode); 871 depth = ext_depth(inode); 872 if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) { 873 EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d", 874 depth); 875 ret = -EFSCORRUPTED; 876 goto err; 877 } 878 879 if (path) { 880 ext4_ext_drop_refs(path); 881 if (depth > path[0].p_maxdepth) { 882 kfree(path); 883 *orig_path = path = NULL; 884 } 885 } 886 if (!path) { 887 /* account possible depth increase */ 888 path = kcalloc(depth + 2, sizeof(struct ext4_ext_path), 889 GFP_NOFS); 890 if (unlikely(!path)) 891 return ERR_PTR(-ENOMEM); 892 path[0].p_maxdepth = depth + 1; 893 } 894 path[0].p_hdr = eh; 895 path[0].p_bh = NULL; 896 897 i = depth; 898 /* walk through the tree */ 899 while (i) { 900 ext_debug("depth %d: num %d, max %d\n", 901 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); 902 903 ext4_ext_binsearch_idx(inode, path + ppos, block); 904 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx); 905 path[ppos].p_depth = i; 906 path[ppos].p_ext = NULL; 907 908 bh = read_extent_tree_block(inode, path[ppos].p_block, --i, 909 flags); 910 if (IS_ERR(bh)) { 911 ret = PTR_ERR(bh); 912 goto err; 913 } 914 915 eh = ext_block_hdr(bh); 916 ppos++; 917 path[ppos].p_bh = bh; 918 path[ppos].p_hdr = eh; 919 } 920 921 path[ppos].p_depth = i; 922 path[ppos].p_ext = NULL; 923 path[ppos].p_idx = NULL; 924 925 /* find extent */ 926 ext4_ext_binsearch(inode, path + ppos, block); 927 /* if not an empty leaf */ 928 if (path[ppos].p_ext) 929 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext); 930 931 ext4_ext_show_path(inode, path); 932 933 return path; 934 935 err: 936 ext4_ext_drop_refs(path); 937 kfree(path); 938 if (orig_path) 939 *orig_path = NULL; 940 return ERR_PTR(ret); 941 } 942 943 /* 944 * ext4_ext_insert_index: 945 * insert new index [@logical;@ptr] into the block at @curp; 946 * check where to insert: before @curp or after @curp 947 */ 948 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, 949 struct ext4_ext_path *curp, 950 int logical, ext4_fsblk_t ptr) 951 { 952 struct ext4_extent_idx *ix; 953 int len, err; 954 955 err = ext4_ext_get_access(handle, inode, curp); 956 if (err) 957 return err; 958 959 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) { 960 EXT4_ERROR_INODE(inode, 961 "logical %d == ei_block %d!", 962 logical, le32_to_cpu(curp->p_idx->ei_block)); 963 return -EFSCORRUPTED; 964 } 965 966 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) 967 >= le16_to_cpu(curp->p_hdr->eh_max))) { 968 EXT4_ERROR_INODE(inode, 969 "eh_entries %d >= eh_max %d!", 970 le16_to_cpu(curp->p_hdr->eh_entries), 971 le16_to_cpu(curp->p_hdr->eh_max)); 972 return -EFSCORRUPTED; 973 } 974 975 if (logical > le32_to_cpu(curp->p_idx->ei_block)) { 976 /* insert after */ 977 ext_debug("insert new index %d after: %llu\n", logical, ptr); 978 ix = curp->p_idx + 1; 979 } else { 980 /* insert before */ 981 ext_debug("insert new index %d before: %llu\n", logical, ptr); 982 ix = curp->p_idx; 983 } 984 985 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1; 986 BUG_ON(len < 0); 987 if (len > 0) { 988 ext_debug("insert new index %d: " 989 "move %d indices from 0x%p to 0x%p\n", 990 logical, len, ix, ix + 1); 991 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx)); 992 } 993 994 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) { 995 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!"); 996 return -EFSCORRUPTED; 997 } 998 999 ix->ei_block = cpu_to_le32(logical); 1000 ext4_idx_store_pblock(ix, ptr); 1001 le16_add_cpu(&curp->p_hdr->eh_entries, 1); 1002 1003 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) { 1004 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!"); 1005 return -EFSCORRUPTED; 1006 } 1007 1008 err = ext4_ext_dirty(handle, inode, curp); 1009 ext4_std_error(inode->i_sb, err); 1010 1011 return err; 1012 } 1013 1014 /* 1015 * ext4_ext_split: 1016 * inserts new subtree into the path, using free index entry 1017 * at depth @at: 1018 * - allocates all needed blocks (new leaf and all intermediate index blocks) 1019 * - makes decision where to split 1020 * - moves remaining extents and index entries (right to the split point) 1021 * into the newly allocated blocks 1022 * - initializes subtree 1023 */ 1024 static int ext4_ext_split(handle_t *handle, struct inode *inode, 1025 unsigned int flags, 1026 struct ext4_ext_path *path, 1027 struct ext4_extent *newext, int at) 1028 { 1029 struct buffer_head *bh = NULL; 1030 int depth = ext_depth(inode); 1031 struct ext4_extent_header *neh; 1032 struct ext4_extent_idx *fidx; 1033 int i = at, k, m, a; 1034 ext4_fsblk_t newblock, oldblock; 1035 __le32 border; 1036 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ 1037 int err = 0; 1038 size_t ext_size = 0; 1039 1040 /* make decision: where to split? */ 1041 /* FIXME: now decision is simplest: at current extent */ 1042 1043 /* if current leaf will be split, then we should use 1044 * border from split point */ 1045 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) { 1046 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!"); 1047 return -EFSCORRUPTED; 1048 } 1049 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { 1050 border = path[depth].p_ext[1].ee_block; 1051 ext_debug("leaf will be split." 1052 " next leaf starts at %d\n", 1053 le32_to_cpu(border)); 1054 } else { 1055 border = newext->ee_block; 1056 ext_debug("leaf will be added." 1057 " next leaf starts at %d\n", 1058 le32_to_cpu(border)); 1059 } 1060 1061 /* 1062 * If error occurs, then we break processing 1063 * and mark filesystem read-only. index won't 1064 * be inserted and tree will be in consistent 1065 * state. Next mount will repair buffers too. 1066 */ 1067 1068 /* 1069 * Get array to track all allocated blocks. 1070 * We need this to handle errors and free blocks 1071 * upon them. 1072 */ 1073 ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), GFP_NOFS); 1074 if (!ablocks) 1075 return -ENOMEM; 1076 1077 /* allocate all needed blocks */ 1078 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); 1079 for (a = 0; a < depth - at; a++) { 1080 newblock = ext4_ext_new_meta_block(handle, inode, path, 1081 newext, &err, flags); 1082 if (newblock == 0) 1083 goto cleanup; 1084 ablocks[a] = newblock; 1085 } 1086 1087 /* initialize new leaf */ 1088 newblock = ablocks[--a]; 1089 if (unlikely(newblock == 0)) { 1090 EXT4_ERROR_INODE(inode, "newblock == 0!"); 1091 err = -EFSCORRUPTED; 1092 goto cleanup; 1093 } 1094 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS); 1095 if (unlikely(!bh)) { 1096 err = -ENOMEM; 1097 goto cleanup; 1098 } 1099 lock_buffer(bh); 1100 1101 err = ext4_journal_get_create_access(handle, bh); 1102 if (err) 1103 goto cleanup; 1104 1105 neh = ext_block_hdr(bh); 1106 neh->eh_entries = 0; 1107 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); 1108 neh->eh_magic = EXT4_EXT_MAGIC; 1109 neh->eh_depth = 0; 1110 1111 /* move remainder of path[depth] to the new leaf */ 1112 if (unlikely(path[depth].p_hdr->eh_entries != 1113 path[depth].p_hdr->eh_max)) { 1114 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!", 1115 path[depth].p_hdr->eh_entries, 1116 path[depth].p_hdr->eh_max); 1117 err = -EFSCORRUPTED; 1118 goto cleanup; 1119 } 1120 /* start copy from next extent */ 1121 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++; 1122 ext4_ext_show_move(inode, path, newblock, depth); 1123 if (m) { 1124 struct ext4_extent *ex; 1125 ex = EXT_FIRST_EXTENT(neh); 1126 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m); 1127 le16_add_cpu(&neh->eh_entries, m); 1128 } 1129 1130 /* zero out unused area in the extent block */ 1131 ext_size = sizeof(struct ext4_extent_header) + 1132 sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries); 1133 memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); 1134 ext4_extent_block_csum_set(inode, neh); 1135 set_buffer_uptodate(bh); 1136 unlock_buffer(bh); 1137 1138 err = ext4_handle_dirty_metadata(handle, inode, bh); 1139 if (err) 1140 goto cleanup; 1141 brelse(bh); 1142 bh = NULL; 1143 1144 /* correct old leaf */ 1145 if (m) { 1146 err = ext4_ext_get_access(handle, inode, path + depth); 1147 if (err) 1148 goto cleanup; 1149 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m); 1150 err = ext4_ext_dirty(handle, inode, path + depth); 1151 if (err) 1152 goto cleanup; 1153 1154 } 1155 1156 /* create intermediate indexes */ 1157 k = depth - at - 1; 1158 if (unlikely(k < 0)) { 1159 EXT4_ERROR_INODE(inode, "k %d < 0!", k); 1160 err = -EFSCORRUPTED; 1161 goto cleanup; 1162 } 1163 if (k) 1164 ext_debug("create %d intermediate indices\n", k); 1165 /* insert new index into current index block */ 1166 /* current depth stored in i var */ 1167 i = depth - 1; 1168 while (k--) { 1169 oldblock = newblock; 1170 newblock = ablocks[--a]; 1171 bh = sb_getblk(inode->i_sb, newblock); 1172 if (unlikely(!bh)) { 1173 err = -ENOMEM; 1174 goto cleanup; 1175 } 1176 lock_buffer(bh); 1177 1178 err = ext4_journal_get_create_access(handle, bh); 1179 if (err) 1180 goto cleanup; 1181 1182 neh = ext_block_hdr(bh); 1183 neh->eh_entries = cpu_to_le16(1); 1184 neh->eh_magic = EXT4_EXT_MAGIC; 1185 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); 1186 neh->eh_depth = cpu_to_le16(depth - i); 1187 fidx = EXT_FIRST_INDEX(neh); 1188 fidx->ei_block = border; 1189 ext4_idx_store_pblock(fidx, oldblock); 1190 1191 ext_debug("int.index at %d (block %llu): %u -> %llu\n", 1192 i, newblock, le32_to_cpu(border), oldblock); 1193 1194 /* move remainder of path[i] to the new index block */ 1195 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) != 1196 EXT_LAST_INDEX(path[i].p_hdr))) { 1197 EXT4_ERROR_INODE(inode, 1198 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!", 1199 le32_to_cpu(path[i].p_ext->ee_block)); 1200 err = -EFSCORRUPTED; 1201 goto cleanup; 1202 } 1203 /* start copy indexes */ 1204 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++; 1205 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, 1206 EXT_MAX_INDEX(path[i].p_hdr)); 1207 ext4_ext_show_move(inode, path, newblock, i); 1208 if (m) { 1209 memmove(++fidx, path[i].p_idx, 1210 sizeof(struct ext4_extent_idx) * m); 1211 le16_add_cpu(&neh->eh_entries, m); 1212 } 1213 /* zero out unused area in the extent block */ 1214 ext_size = sizeof(struct ext4_extent_header) + 1215 (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries)); 1216 memset(bh->b_data + ext_size, 0, 1217 inode->i_sb->s_blocksize - ext_size); 1218 ext4_extent_block_csum_set(inode, neh); 1219 set_buffer_uptodate(bh); 1220 unlock_buffer(bh); 1221 1222 err = ext4_handle_dirty_metadata(handle, inode, bh); 1223 if (err) 1224 goto cleanup; 1225 brelse(bh); 1226 bh = NULL; 1227 1228 /* correct old index */ 1229 if (m) { 1230 err = ext4_ext_get_access(handle, inode, path + i); 1231 if (err) 1232 goto cleanup; 1233 le16_add_cpu(&path[i].p_hdr->eh_entries, -m); 1234 err = ext4_ext_dirty(handle, inode, path + i); 1235 if (err) 1236 goto cleanup; 1237 } 1238 1239 i--; 1240 } 1241 1242 /* insert new index */ 1243 err = ext4_ext_insert_index(handle, inode, path + at, 1244 le32_to_cpu(border), newblock); 1245 1246 cleanup: 1247 if (bh) { 1248 if (buffer_locked(bh)) 1249 unlock_buffer(bh); 1250 brelse(bh); 1251 } 1252 1253 if (err) { 1254 /* free all allocated blocks in error case */ 1255 for (i = 0; i < depth; i++) { 1256 if (!ablocks[i]) 1257 continue; 1258 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1, 1259 EXT4_FREE_BLOCKS_METADATA); 1260 } 1261 } 1262 kfree(ablocks); 1263 1264 return err; 1265 } 1266 1267 /* 1268 * ext4_ext_grow_indepth: 1269 * implements tree growing procedure: 1270 * - allocates new block 1271 * - moves top-level data (index block or leaf) into the new block 1272 * - initializes new top-level, creating index that points to the 1273 * just created block 1274 */ 1275 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, 1276 unsigned int flags) 1277 { 1278 struct ext4_extent_header *neh; 1279 struct buffer_head *bh; 1280 ext4_fsblk_t newblock, goal = 0; 1281 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; 1282 int err = 0; 1283 size_t ext_size = 0; 1284 1285 /* Try to prepend new index to old one */ 1286 if (ext_depth(inode)) 1287 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode))); 1288 if (goal > le32_to_cpu(es->s_first_data_block)) { 1289 flags |= EXT4_MB_HINT_TRY_GOAL; 1290 goal--; 1291 } else 1292 goal = ext4_inode_to_goal_block(inode); 1293 newblock = ext4_new_meta_blocks(handle, inode, goal, flags, 1294 NULL, &err); 1295 if (newblock == 0) 1296 return err; 1297 1298 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS); 1299 if (unlikely(!bh)) 1300 return -ENOMEM; 1301 lock_buffer(bh); 1302 1303 err = ext4_journal_get_create_access(handle, bh); 1304 if (err) { 1305 unlock_buffer(bh); 1306 goto out; 1307 } 1308 1309 ext_size = sizeof(EXT4_I(inode)->i_data); 1310 /* move top-level index/leaf into new block */ 1311 memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size); 1312 /* zero out unused area in the extent block */ 1313 memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); 1314 1315 /* set size of new block */ 1316 neh = ext_block_hdr(bh); 1317 /* old root could have indexes or leaves 1318 * so calculate e_max right way */ 1319 if (ext_depth(inode)) 1320 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); 1321 else 1322 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); 1323 neh->eh_magic = EXT4_EXT_MAGIC; 1324 ext4_extent_block_csum_set(inode, neh); 1325 set_buffer_uptodate(bh); 1326 unlock_buffer(bh); 1327 1328 err = ext4_handle_dirty_metadata(handle, inode, bh); 1329 if (err) 1330 goto out; 1331 1332 /* Update top-level index: num,max,pointer */ 1333 neh = ext_inode_hdr(inode); 1334 neh->eh_entries = cpu_to_le16(1); 1335 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock); 1336 if (neh->eh_depth == 0) { 1337 /* Root extent block becomes index block */ 1338 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); 1339 EXT_FIRST_INDEX(neh)->ei_block = 1340 EXT_FIRST_EXTENT(neh)->ee_block; 1341 } 1342 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", 1343 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), 1344 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), 1345 ext4_idx_pblock(EXT_FIRST_INDEX(neh))); 1346 1347 le16_add_cpu(&neh->eh_depth, 1); 1348 ext4_mark_inode_dirty(handle, inode); 1349 out: 1350 brelse(bh); 1351 1352 return err; 1353 } 1354 1355 /* 1356 * ext4_ext_create_new_leaf: 1357 * finds empty index and adds new leaf. 1358 * if no free index is found, then it requests in-depth growing. 1359 */ 1360 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, 1361 unsigned int mb_flags, 1362 unsigned int gb_flags, 1363 struct ext4_ext_path **ppath, 1364 struct ext4_extent *newext) 1365 { 1366 struct ext4_ext_path *path = *ppath; 1367 struct ext4_ext_path *curp; 1368 int depth, i, err = 0; 1369 1370 repeat: 1371 i = depth = ext_depth(inode); 1372 1373 /* walk up to the tree and look for free index entry */ 1374 curp = path + depth; 1375 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { 1376 i--; 1377 curp--; 1378 } 1379 1380 /* we use already allocated block for index block, 1381 * so subsequent data blocks should be contiguous */ 1382 if (EXT_HAS_FREE_INDEX(curp)) { 1383 /* if we found index with free entry, then use that 1384 * entry: create all needed subtree and add new leaf */ 1385 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i); 1386 if (err) 1387 goto out; 1388 1389 /* refill path */ 1390 path = ext4_find_extent(inode, 1391 (ext4_lblk_t)le32_to_cpu(newext->ee_block), 1392 ppath, gb_flags); 1393 if (IS_ERR(path)) 1394 err = PTR_ERR(path); 1395 } else { 1396 /* tree is full, time to grow in depth */ 1397 err = ext4_ext_grow_indepth(handle, inode, mb_flags); 1398 if (err) 1399 goto out; 1400 1401 /* refill path */ 1402 path = ext4_find_extent(inode, 1403 (ext4_lblk_t)le32_to_cpu(newext->ee_block), 1404 ppath, gb_flags); 1405 if (IS_ERR(path)) { 1406 err = PTR_ERR(path); 1407 goto out; 1408 } 1409 1410 /* 1411 * only first (depth 0 -> 1) produces free space; 1412 * in all other cases we have to split the grown tree 1413 */ 1414 depth = ext_depth(inode); 1415 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { 1416 /* now we need to split */ 1417 goto repeat; 1418 } 1419 } 1420 1421 out: 1422 return err; 1423 } 1424 1425 /* 1426 * search the closest allocated block to the left for *logical 1427 * and returns it at @logical + it's physical address at @phys 1428 * if *logical is the smallest allocated block, the function 1429 * returns 0 at @phys 1430 * return value contains 0 (success) or error code 1431 */ 1432 static int ext4_ext_search_left(struct inode *inode, 1433 struct ext4_ext_path *path, 1434 ext4_lblk_t *logical, ext4_fsblk_t *phys) 1435 { 1436 struct ext4_extent_idx *ix; 1437 struct ext4_extent *ex; 1438 int depth, ee_len; 1439 1440 if (unlikely(path == NULL)) { 1441 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); 1442 return -EFSCORRUPTED; 1443 } 1444 depth = path->p_depth; 1445 *phys = 0; 1446 1447 if (depth == 0 && path->p_ext == NULL) 1448 return 0; 1449 1450 /* usually extent in the path covers blocks smaller 1451 * then *logical, but it can be that extent is the 1452 * first one in the file */ 1453 1454 ex = path[depth].p_ext; 1455 ee_len = ext4_ext_get_actual_len(ex); 1456 if (*logical < le32_to_cpu(ex->ee_block)) { 1457 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { 1458 EXT4_ERROR_INODE(inode, 1459 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!", 1460 *logical, le32_to_cpu(ex->ee_block)); 1461 return -EFSCORRUPTED; 1462 } 1463 while (--depth >= 0) { 1464 ix = path[depth].p_idx; 1465 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { 1466 EXT4_ERROR_INODE(inode, 1467 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!", 1468 ix != NULL ? le32_to_cpu(ix->ei_block) : 0, 1469 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ? 1470 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0, 1471 depth); 1472 return -EFSCORRUPTED; 1473 } 1474 } 1475 return 0; 1476 } 1477 1478 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { 1479 EXT4_ERROR_INODE(inode, 1480 "logical %d < ee_block %d + ee_len %d!", 1481 *logical, le32_to_cpu(ex->ee_block), ee_len); 1482 return -EFSCORRUPTED; 1483 } 1484 1485 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; 1486 *phys = ext4_ext_pblock(ex) + ee_len - 1; 1487 return 0; 1488 } 1489 1490 /* 1491 * search the closest allocated block to the right for *logical 1492 * and returns it at @logical + it's physical address at @phys 1493 * if *logical is the largest allocated block, the function 1494 * returns 0 at @phys 1495 * return value contains 0 (success) or error code 1496 */ 1497 static int ext4_ext_search_right(struct inode *inode, 1498 struct ext4_ext_path *path, 1499 ext4_lblk_t *logical, ext4_fsblk_t *phys, 1500 struct ext4_extent **ret_ex) 1501 { 1502 struct buffer_head *bh = NULL; 1503 struct ext4_extent_header *eh; 1504 struct ext4_extent_idx *ix; 1505 struct ext4_extent *ex; 1506 ext4_fsblk_t block; 1507 int depth; /* Note, NOT eh_depth; depth from top of tree */ 1508 int ee_len; 1509 1510 if (unlikely(path == NULL)) { 1511 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); 1512 return -EFSCORRUPTED; 1513 } 1514 depth = path->p_depth; 1515 *phys = 0; 1516 1517 if (depth == 0 && path->p_ext == NULL) 1518 return 0; 1519 1520 /* usually extent in the path covers blocks smaller 1521 * then *logical, but it can be that extent is the 1522 * first one in the file */ 1523 1524 ex = path[depth].p_ext; 1525 ee_len = ext4_ext_get_actual_len(ex); 1526 if (*logical < le32_to_cpu(ex->ee_block)) { 1527 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { 1528 EXT4_ERROR_INODE(inode, 1529 "first_extent(path[%d].p_hdr) != ex", 1530 depth); 1531 return -EFSCORRUPTED; 1532 } 1533 while (--depth >= 0) { 1534 ix = path[depth].p_idx; 1535 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { 1536 EXT4_ERROR_INODE(inode, 1537 "ix != EXT_FIRST_INDEX *logical %d!", 1538 *logical); 1539 return -EFSCORRUPTED; 1540 } 1541 } 1542 goto found_extent; 1543 } 1544 1545 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { 1546 EXT4_ERROR_INODE(inode, 1547 "logical %d < ee_block %d + ee_len %d!", 1548 *logical, le32_to_cpu(ex->ee_block), ee_len); 1549 return -EFSCORRUPTED; 1550 } 1551 1552 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { 1553 /* next allocated block in this leaf */ 1554 ex++; 1555 goto found_extent; 1556 } 1557 1558 /* go up and search for index to the right */ 1559 while (--depth >= 0) { 1560 ix = path[depth].p_idx; 1561 if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) 1562 goto got_index; 1563 } 1564 1565 /* we've gone up to the root and found no index to the right */ 1566 return 0; 1567 1568 got_index: 1569 /* we've found index to the right, let's 1570 * follow it and find the closest allocated 1571 * block to the right */ 1572 ix++; 1573 block = ext4_idx_pblock(ix); 1574 while (++depth < path->p_depth) { 1575 /* subtract from p_depth to get proper eh_depth */ 1576 bh = read_extent_tree_block(inode, block, 1577 path->p_depth - depth, 0); 1578 if (IS_ERR(bh)) 1579 return PTR_ERR(bh); 1580 eh = ext_block_hdr(bh); 1581 ix = EXT_FIRST_INDEX(eh); 1582 block = ext4_idx_pblock(ix); 1583 put_bh(bh); 1584 } 1585 1586 bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0); 1587 if (IS_ERR(bh)) 1588 return PTR_ERR(bh); 1589 eh = ext_block_hdr(bh); 1590 ex = EXT_FIRST_EXTENT(eh); 1591 found_extent: 1592 *logical = le32_to_cpu(ex->ee_block); 1593 *phys = ext4_ext_pblock(ex); 1594 *ret_ex = ex; 1595 if (bh) 1596 put_bh(bh); 1597 return 0; 1598 } 1599 1600 /* 1601 * ext4_ext_next_allocated_block: 1602 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS. 1603 * NOTE: it considers block number from index entry as 1604 * allocated block. Thus, index entries have to be consistent 1605 * with leaves. 1606 */ 1607 ext4_lblk_t 1608 ext4_ext_next_allocated_block(struct ext4_ext_path *path) 1609 { 1610 int depth; 1611 1612 BUG_ON(path == NULL); 1613 depth = path->p_depth; 1614 1615 if (depth == 0 && path->p_ext == NULL) 1616 return EXT_MAX_BLOCKS; 1617 1618 while (depth >= 0) { 1619 if (depth == path->p_depth) { 1620 /* leaf */ 1621 if (path[depth].p_ext && 1622 path[depth].p_ext != 1623 EXT_LAST_EXTENT(path[depth].p_hdr)) 1624 return le32_to_cpu(path[depth].p_ext[1].ee_block); 1625 } else { 1626 /* index */ 1627 if (path[depth].p_idx != 1628 EXT_LAST_INDEX(path[depth].p_hdr)) 1629 return le32_to_cpu(path[depth].p_idx[1].ei_block); 1630 } 1631 depth--; 1632 } 1633 1634 return EXT_MAX_BLOCKS; 1635 } 1636 1637 /* 1638 * ext4_ext_next_leaf_block: 1639 * returns first allocated block from next leaf or EXT_MAX_BLOCKS 1640 */ 1641 static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path) 1642 { 1643 int depth; 1644 1645 BUG_ON(path == NULL); 1646 depth = path->p_depth; 1647 1648 /* zero-tree has no leaf blocks at all */ 1649 if (depth == 0) 1650 return EXT_MAX_BLOCKS; 1651 1652 /* go to index block */ 1653 depth--; 1654 1655 while (depth >= 0) { 1656 if (path[depth].p_idx != 1657 EXT_LAST_INDEX(path[depth].p_hdr)) 1658 return (ext4_lblk_t) 1659 le32_to_cpu(path[depth].p_idx[1].ei_block); 1660 depth--; 1661 } 1662 1663 return EXT_MAX_BLOCKS; 1664 } 1665 1666 /* 1667 * ext4_ext_correct_indexes: 1668 * if leaf gets modified and modified extent is first in the leaf, 1669 * then we have to correct all indexes above. 1670 * TODO: do we need to correct tree in all cases? 1671 */ 1672 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, 1673 struct ext4_ext_path *path) 1674 { 1675 struct ext4_extent_header *eh; 1676 int depth = ext_depth(inode); 1677 struct ext4_extent *ex; 1678 __le32 border; 1679 int k, err = 0; 1680 1681 eh = path[depth].p_hdr; 1682 ex = path[depth].p_ext; 1683 1684 if (unlikely(ex == NULL || eh == NULL)) { 1685 EXT4_ERROR_INODE(inode, 1686 "ex %p == NULL or eh %p == NULL", ex, eh); 1687 return -EFSCORRUPTED; 1688 } 1689 1690 if (depth == 0) { 1691 /* there is no tree at all */ 1692 return 0; 1693 } 1694 1695 if (ex != EXT_FIRST_EXTENT(eh)) { 1696 /* we correct tree if first leaf got modified only */ 1697 return 0; 1698 } 1699 1700 /* 1701 * TODO: we need correction if border is smaller than current one 1702 */ 1703 k = depth - 1; 1704 border = path[depth].p_ext->ee_block; 1705 err = ext4_ext_get_access(handle, inode, path + k); 1706 if (err) 1707 return err; 1708 path[k].p_idx->ei_block = border; 1709 err = ext4_ext_dirty(handle, inode, path + k); 1710 if (err) 1711 return err; 1712 1713 while (k--) { 1714 /* change all left-side indexes */ 1715 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) 1716 break; 1717 err = ext4_ext_get_access(handle, inode, path + k); 1718 if (err) 1719 break; 1720 path[k].p_idx->ei_block = border; 1721 err = ext4_ext_dirty(handle, inode, path + k); 1722 if (err) 1723 break; 1724 } 1725 1726 return err; 1727 } 1728 1729 int 1730 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, 1731 struct ext4_extent *ex2) 1732 { 1733 unsigned short ext1_ee_len, ext2_ee_len; 1734 1735 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2)) 1736 return 0; 1737 1738 ext1_ee_len = ext4_ext_get_actual_len(ex1); 1739 ext2_ee_len = ext4_ext_get_actual_len(ex2); 1740 1741 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != 1742 le32_to_cpu(ex2->ee_block)) 1743 return 0; 1744 1745 /* 1746 * To allow future support for preallocated extents to be added 1747 * as an RO_COMPAT feature, refuse to merge to extents if 1748 * this can result in the top bit of ee_len being set. 1749 */ 1750 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN) 1751 return 0; 1752 /* 1753 * The check for IO to unwritten extent is somewhat racy as we 1754 * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after 1755 * dropping i_data_sem. But reserved blocks should save us in that 1756 * case. 1757 */ 1758 if (ext4_ext_is_unwritten(ex1) && 1759 (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) || 1760 atomic_read(&EXT4_I(inode)->i_unwritten) || 1761 (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN))) 1762 return 0; 1763 #ifdef AGGRESSIVE_TEST 1764 if (ext1_ee_len >= 4) 1765 return 0; 1766 #endif 1767 1768 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2)) 1769 return 1; 1770 return 0; 1771 } 1772 1773 /* 1774 * This function tries to merge the "ex" extent to the next extent in the tree. 1775 * It always tries to merge towards right. If you want to merge towards 1776 * left, pass "ex - 1" as argument instead of "ex". 1777 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns 1778 * 1 if they got merged. 1779 */ 1780 static int ext4_ext_try_to_merge_right(struct inode *inode, 1781 struct ext4_ext_path *path, 1782 struct ext4_extent *ex) 1783 { 1784 struct ext4_extent_header *eh; 1785 unsigned int depth, len; 1786 int merge_done = 0, unwritten; 1787 1788 depth = ext_depth(inode); 1789 BUG_ON(path[depth].p_hdr == NULL); 1790 eh = path[depth].p_hdr; 1791 1792 while (ex < EXT_LAST_EXTENT(eh)) { 1793 if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) 1794 break; 1795 /* merge with next extent! */ 1796 unwritten = ext4_ext_is_unwritten(ex); 1797 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 1798 + ext4_ext_get_actual_len(ex + 1)); 1799 if (unwritten) 1800 ext4_ext_mark_unwritten(ex); 1801 1802 if (ex + 1 < EXT_LAST_EXTENT(eh)) { 1803 len = (EXT_LAST_EXTENT(eh) - ex - 1) 1804 * sizeof(struct ext4_extent); 1805 memmove(ex + 1, ex + 2, len); 1806 } 1807 le16_add_cpu(&eh->eh_entries, -1); 1808 merge_done = 1; 1809 WARN_ON(eh->eh_entries == 0); 1810 if (!eh->eh_entries) 1811 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!"); 1812 } 1813 1814 return merge_done; 1815 } 1816 1817 /* 1818 * This function does a very simple check to see if we can collapse 1819 * an extent tree with a single extent tree leaf block into the inode. 1820 */ 1821 static void ext4_ext_try_to_merge_up(handle_t *handle, 1822 struct inode *inode, 1823 struct ext4_ext_path *path) 1824 { 1825 size_t s; 1826 unsigned max_root = ext4_ext_space_root(inode, 0); 1827 ext4_fsblk_t blk; 1828 1829 if ((path[0].p_depth != 1) || 1830 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) || 1831 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root)) 1832 return; 1833 1834 /* 1835 * We need to modify the block allocation bitmap and the block 1836 * group descriptor to release the extent tree block. If we 1837 * can't get the journal credits, give up. 1838 */ 1839 if (ext4_journal_extend(handle, 2)) 1840 return; 1841 1842 /* 1843 * Copy the extent data up to the inode 1844 */ 1845 blk = ext4_idx_pblock(path[0].p_idx); 1846 s = le16_to_cpu(path[1].p_hdr->eh_entries) * 1847 sizeof(struct ext4_extent_idx); 1848 s += sizeof(struct ext4_extent_header); 1849 1850 path[1].p_maxdepth = path[0].p_maxdepth; 1851 memcpy(path[0].p_hdr, path[1].p_hdr, s); 1852 path[0].p_depth = 0; 1853 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) + 1854 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr)); 1855 path[0].p_hdr->eh_max = cpu_to_le16(max_root); 1856 1857 brelse(path[1].p_bh); 1858 ext4_free_blocks(handle, inode, NULL, blk, 1, 1859 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); 1860 } 1861 1862 /* 1863 * This function tries to merge the @ex extent to neighbours in the tree. 1864 * return 1 if merge left else 0. 1865 */ 1866 static void ext4_ext_try_to_merge(handle_t *handle, 1867 struct inode *inode, 1868 struct ext4_ext_path *path, 1869 struct ext4_extent *ex) { 1870 struct ext4_extent_header *eh; 1871 unsigned int depth; 1872 int merge_done = 0; 1873 1874 depth = ext_depth(inode); 1875 BUG_ON(path[depth].p_hdr == NULL); 1876 eh = path[depth].p_hdr; 1877 1878 if (ex > EXT_FIRST_EXTENT(eh)) 1879 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1); 1880 1881 if (!merge_done) 1882 (void) ext4_ext_try_to_merge_right(inode, path, ex); 1883 1884 ext4_ext_try_to_merge_up(handle, inode, path); 1885 } 1886 1887 /* 1888 * check if a portion of the "newext" extent overlaps with an 1889 * existing extent. 1890 * 1891 * If there is an overlap discovered, it updates the length of the newext 1892 * such that there will be no overlap, and then returns 1. 1893 * If there is no overlap found, it returns 0. 1894 */ 1895 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi, 1896 struct inode *inode, 1897 struct ext4_extent *newext, 1898 struct ext4_ext_path *path) 1899 { 1900 ext4_lblk_t b1, b2; 1901 unsigned int depth, len1; 1902 unsigned int ret = 0; 1903 1904 b1 = le32_to_cpu(newext->ee_block); 1905 len1 = ext4_ext_get_actual_len(newext); 1906 depth = ext_depth(inode); 1907 if (!path[depth].p_ext) 1908 goto out; 1909 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block)); 1910 1911 /* 1912 * get the next allocated block if the extent in the path 1913 * is before the requested block(s) 1914 */ 1915 if (b2 < b1) { 1916 b2 = ext4_ext_next_allocated_block(path); 1917 if (b2 == EXT_MAX_BLOCKS) 1918 goto out; 1919 b2 = EXT4_LBLK_CMASK(sbi, b2); 1920 } 1921 1922 /* check for wrap through zero on extent logical start block*/ 1923 if (b1 + len1 < b1) { 1924 len1 = EXT_MAX_BLOCKS - b1; 1925 newext->ee_len = cpu_to_le16(len1); 1926 ret = 1; 1927 } 1928 1929 /* check for overlap */ 1930 if (b1 + len1 > b2) { 1931 newext->ee_len = cpu_to_le16(b2 - b1); 1932 ret = 1; 1933 } 1934 out: 1935 return ret; 1936 } 1937 1938 /* 1939 * ext4_ext_insert_extent: 1940 * tries to merge requsted extent into the existing extent or 1941 * inserts requested extent as new one into the tree, 1942 * creating new leaf in the no-space case. 1943 */ 1944 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, 1945 struct ext4_ext_path **ppath, 1946 struct ext4_extent *newext, int gb_flags) 1947 { 1948 struct ext4_ext_path *path = *ppath; 1949 struct ext4_extent_header *eh; 1950 struct ext4_extent *ex, *fex; 1951 struct ext4_extent *nearex; /* nearest extent */ 1952 struct ext4_ext_path *npath = NULL; 1953 int depth, len, err; 1954 ext4_lblk_t next; 1955 int mb_flags = 0, unwritten; 1956 1957 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) 1958 mb_flags |= EXT4_MB_DELALLOC_RESERVED; 1959 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) { 1960 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0"); 1961 return -EFSCORRUPTED; 1962 } 1963 depth = ext_depth(inode); 1964 ex = path[depth].p_ext; 1965 eh = path[depth].p_hdr; 1966 if (unlikely(path[depth].p_hdr == NULL)) { 1967 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); 1968 return -EFSCORRUPTED; 1969 } 1970 1971 /* try to insert block into found extent and return */ 1972 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) { 1973 1974 /* 1975 * Try to see whether we should rather test the extent on 1976 * right from ex, or from the left of ex. This is because 1977 * ext4_find_extent() can return either extent on the 1978 * left, or on the right from the searched position. This 1979 * will make merging more effective. 1980 */ 1981 if (ex < EXT_LAST_EXTENT(eh) && 1982 (le32_to_cpu(ex->ee_block) + 1983 ext4_ext_get_actual_len(ex) < 1984 le32_to_cpu(newext->ee_block))) { 1985 ex += 1; 1986 goto prepend; 1987 } else if ((ex > EXT_FIRST_EXTENT(eh)) && 1988 (le32_to_cpu(newext->ee_block) + 1989 ext4_ext_get_actual_len(newext) < 1990 le32_to_cpu(ex->ee_block))) 1991 ex -= 1; 1992 1993 /* Try to append newex to the ex */ 1994 if (ext4_can_extents_be_merged(inode, ex, newext)) { 1995 ext_debug("append [%d]%d block to %u:[%d]%d" 1996 "(from %llu)\n", 1997 ext4_ext_is_unwritten(newext), 1998 ext4_ext_get_actual_len(newext), 1999 le32_to_cpu(ex->ee_block), 2000 ext4_ext_is_unwritten(ex), 2001 ext4_ext_get_actual_len(ex), 2002 ext4_ext_pblock(ex)); 2003 err = ext4_ext_get_access(handle, inode, 2004 path + depth); 2005 if (err) 2006 return err; 2007 unwritten = ext4_ext_is_unwritten(ex); 2008 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 2009 + ext4_ext_get_actual_len(newext)); 2010 if (unwritten) 2011 ext4_ext_mark_unwritten(ex); 2012 eh = path[depth].p_hdr; 2013 nearex = ex; 2014 goto merge; 2015 } 2016 2017 prepend: 2018 /* Try to prepend newex to the ex */ 2019 if (ext4_can_extents_be_merged(inode, newext, ex)) { 2020 ext_debug("prepend %u[%d]%d block to %u:[%d]%d" 2021 "(from %llu)\n", 2022 le32_to_cpu(newext->ee_block), 2023 ext4_ext_is_unwritten(newext), 2024 ext4_ext_get_actual_len(newext), 2025 le32_to_cpu(ex->ee_block), 2026 ext4_ext_is_unwritten(ex), 2027 ext4_ext_get_actual_len(ex), 2028 ext4_ext_pblock(ex)); 2029 err = ext4_ext_get_access(handle, inode, 2030 path + depth); 2031 if (err) 2032 return err; 2033 2034 unwritten = ext4_ext_is_unwritten(ex); 2035 ex->ee_block = newext->ee_block; 2036 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext)); 2037 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) 2038 + ext4_ext_get_actual_len(newext)); 2039 if (unwritten) 2040 ext4_ext_mark_unwritten(ex); 2041 eh = path[depth].p_hdr; 2042 nearex = ex; 2043 goto merge; 2044 } 2045 } 2046 2047 depth = ext_depth(inode); 2048 eh = path[depth].p_hdr; 2049 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) 2050 goto has_space; 2051 2052 /* probably next leaf has space for us? */ 2053 fex = EXT_LAST_EXTENT(eh); 2054 next = EXT_MAX_BLOCKS; 2055 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)) 2056 next = ext4_ext_next_leaf_block(path); 2057 if (next != EXT_MAX_BLOCKS) { 2058 ext_debug("next leaf block - %u\n", next); 2059 BUG_ON(npath != NULL); 2060 npath = ext4_find_extent(inode, next, NULL, 0); 2061 if (IS_ERR(npath)) 2062 return PTR_ERR(npath); 2063 BUG_ON(npath->p_depth != path->p_depth); 2064 eh = npath[depth].p_hdr; 2065 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { 2066 ext_debug("next leaf isn't full(%d)\n", 2067 le16_to_cpu(eh->eh_entries)); 2068 path = npath; 2069 goto has_space; 2070 } 2071 ext_debug("next leaf has no free space(%d,%d)\n", 2072 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); 2073 } 2074 2075 /* 2076 * There is no free space in the found leaf. 2077 * We're gonna add a new leaf in the tree. 2078 */ 2079 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) 2080 mb_flags |= EXT4_MB_USE_RESERVED; 2081 err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags, 2082 ppath, newext); 2083 if (err) 2084 goto cleanup; 2085 depth = ext_depth(inode); 2086 eh = path[depth].p_hdr; 2087 2088 has_space: 2089 nearex = path[depth].p_ext; 2090 2091 err = ext4_ext_get_access(handle, inode, path + depth); 2092 if (err) 2093 goto cleanup; 2094 2095 if (!nearex) { 2096 /* there is no extent in this leaf, create first one */ 2097 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n", 2098 le32_to_cpu(newext->ee_block), 2099 ext4_ext_pblock(newext), 2100 ext4_ext_is_unwritten(newext), 2101 ext4_ext_get_actual_len(newext)); 2102 nearex = EXT_FIRST_EXTENT(eh); 2103 } else { 2104 if (le32_to_cpu(newext->ee_block) 2105 > le32_to_cpu(nearex->ee_block)) { 2106 /* Insert after */ 2107 ext_debug("insert %u:%llu:[%d]%d before: " 2108 "nearest %p\n", 2109 le32_to_cpu(newext->ee_block), 2110 ext4_ext_pblock(newext), 2111 ext4_ext_is_unwritten(newext), 2112 ext4_ext_get_actual_len(newext), 2113 nearex); 2114 nearex++; 2115 } else { 2116 /* Insert before */ 2117 BUG_ON(newext->ee_block == nearex->ee_block); 2118 ext_debug("insert %u:%llu:[%d]%d after: " 2119 "nearest %p\n", 2120 le32_to_cpu(newext->ee_block), 2121 ext4_ext_pblock(newext), 2122 ext4_ext_is_unwritten(newext), 2123 ext4_ext_get_actual_len(newext), 2124 nearex); 2125 } 2126 len = EXT_LAST_EXTENT(eh) - nearex + 1; 2127 if (len > 0) { 2128 ext_debug("insert %u:%llu:[%d]%d: " 2129 "move %d extents from 0x%p to 0x%p\n", 2130 le32_to_cpu(newext->ee_block), 2131 ext4_ext_pblock(newext), 2132 ext4_ext_is_unwritten(newext), 2133 ext4_ext_get_actual_len(newext), 2134 len, nearex, nearex + 1); 2135 memmove(nearex + 1, nearex, 2136 len * sizeof(struct ext4_extent)); 2137 } 2138 } 2139 2140 le16_add_cpu(&eh->eh_entries, 1); 2141 path[depth].p_ext = nearex; 2142 nearex->ee_block = newext->ee_block; 2143 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext)); 2144 nearex->ee_len = newext->ee_len; 2145 2146 merge: 2147 /* try to merge extents */ 2148 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) 2149 ext4_ext_try_to_merge(handle, inode, path, nearex); 2150 2151 2152 /* time to correct all indexes above */ 2153 err = ext4_ext_correct_indexes(handle, inode, path); 2154 if (err) 2155 goto cleanup; 2156 2157 err = ext4_ext_dirty(handle, inode, path + path->p_depth); 2158 2159 cleanup: 2160 ext4_ext_drop_refs(npath); 2161 kfree(npath); 2162 return err; 2163 } 2164 2165 static int ext4_fill_fiemap_extents(struct inode *inode, 2166 ext4_lblk_t block, ext4_lblk_t num, 2167 struct fiemap_extent_info *fieinfo) 2168 { 2169 struct ext4_ext_path *path = NULL; 2170 struct ext4_extent *ex; 2171 struct extent_status es; 2172 ext4_lblk_t next, next_del, start = 0, end = 0; 2173 ext4_lblk_t last = block + num; 2174 int exists, depth = 0, err = 0; 2175 unsigned int flags = 0; 2176 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits; 2177 2178 while (block < last && block != EXT_MAX_BLOCKS) { 2179 num = last - block; 2180 /* find extent for this block */ 2181 down_read(&EXT4_I(inode)->i_data_sem); 2182 2183 path = ext4_find_extent(inode, block, &path, 0); 2184 if (IS_ERR(path)) { 2185 up_read(&EXT4_I(inode)->i_data_sem); 2186 err = PTR_ERR(path); 2187 path = NULL; 2188 break; 2189 } 2190 2191 depth = ext_depth(inode); 2192 if (unlikely(path[depth].p_hdr == NULL)) { 2193 up_read(&EXT4_I(inode)->i_data_sem); 2194 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); 2195 err = -EFSCORRUPTED; 2196 break; 2197 } 2198 ex = path[depth].p_ext; 2199 next = ext4_ext_next_allocated_block(path); 2200 2201 flags = 0; 2202 exists = 0; 2203 if (!ex) { 2204 /* there is no extent yet, so try to allocate 2205 * all requested space */ 2206 start = block; 2207 end = block + num; 2208 } else if (le32_to_cpu(ex->ee_block) > block) { 2209 /* need to allocate space before found extent */ 2210 start = block; 2211 end = le32_to_cpu(ex->ee_block); 2212 if (block + num < end) 2213 end = block + num; 2214 } else if (block >= le32_to_cpu(ex->ee_block) 2215 + ext4_ext_get_actual_len(ex)) { 2216 /* need to allocate space after found extent */ 2217 start = block; 2218 end = block + num; 2219 if (end >= next) 2220 end = next; 2221 } else if (block >= le32_to_cpu(ex->ee_block)) { 2222 /* 2223 * some part of requested space is covered 2224 * by found extent 2225 */ 2226 start = block; 2227 end = le32_to_cpu(ex->ee_block) 2228 + ext4_ext_get_actual_len(ex); 2229 if (block + num < end) 2230 end = block + num; 2231 exists = 1; 2232 } else { 2233 BUG(); 2234 } 2235 BUG_ON(end <= start); 2236 2237 if (!exists) { 2238 es.es_lblk = start; 2239 es.es_len = end - start; 2240 es.es_pblk = 0; 2241 } else { 2242 es.es_lblk = le32_to_cpu(ex->ee_block); 2243 es.es_len = ext4_ext_get_actual_len(ex); 2244 es.es_pblk = ext4_ext_pblock(ex); 2245 if (ext4_ext_is_unwritten(ex)) 2246 flags |= FIEMAP_EXTENT_UNWRITTEN; 2247 } 2248 2249 /* 2250 * Find delayed extent and update es accordingly. We call 2251 * it even in !exists case to find out whether es is the 2252 * last existing extent or not. 2253 */ 2254 next_del = ext4_find_delayed_extent(inode, &es); 2255 if (!exists && next_del) { 2256 exists = 1; 2257 flags |= (FIEMAP_EXTENT_DELALLOC | 2258 FIEMAP_EXTENT_UNKNOWN); 2259 } 2260 up_read(&EXT4_I(inode)->i_data_sem); 2261 2262 if (unlikely(es.es_len == 0)) { 2263 EXT4_ERROR_INODE(inode, "es.es_len == 0"); 2264 err = -EFSCORRUPTED; 2265 break; 2266 } 2267 2268 /* 2269 * This is possible iff next == next_del == EXT_MAX_BLOCKS. 2270 * we need to check next == EXT_MAX_BLOCKS because it is 2271 * possible that an extent is with unwritten and delayed 2272 * status due to when an extent is delayed allocated and 2273 * is allocated by fallocate status tree will track both of 2274 * them in a extent. 2275 * 2276 * So we could return a unwritten and delayed extent, and 2277 * its block is equal to 'next'. 2278 */ 2279 if (next == next_del && next == EXT_MAX_BLOCKS) { 2280 flags |= FIEMAP_EXTENT_LAST; 2281 if (unlikely(next_del != EXT_MAX_BLOCKS || 2282 next != EXT_MAX_BLOCKS)) { 2283 EXT4_ERROR_INODE(inode, 2284 "next extent == %u, next " 2285 "delalloc extent = %u", 2286 next, next_del); 2287 err = -EFSCORRUPTED; 2288 break; 2289 } 2290 } 2291 2292 if (exists) { 2293 err = fiemap_fill_next_extent(fieinfo, 2294 (__u64)es.es_lblk << blksize_bits, 2295 (__u64)es.es_pblk << blksize_bits, 2296 (__u64)es.es_len << blksize_bits, 2297 flags); 2298 if (err < 0) 2299 break; 2300 if (err == 1) { 2301 err = 0; 2302 break; 2303 } 2304 } 2305 2306 block = es.es_lblk + es.es_len; 2307 } 2308 2309 ext4_ext_drop_refs(path); 2310 kfree(path); 2311 return err; 2312 } 2313 2314 /* 2315 * ext4_ext_determine_hole - determine hole around given block 2316 * @inode: inode we lookup in 2317 * @path: path in extent tree to @lblk 2318 * @lblk: pointer to logical block around which we want to determine hole 2319 * 2320 * Determine hole length (and start if easily possible) around given logical 2321 * block. We don't try too hard to find the beginning of the hole but @path 2322 * actually points to extent before @lblk, we provide it. 2323 * 2324 * The function returns the length of a hole starting at @lblk. We update @lblk 2325 * to the beginning of the hole if we managed to find it. 2326 */ 2327 static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode, 2328 struct ext4_ext_path *path, 2329 ext4_lblk_t *lblk) 2330 { 2331 int depth = ext_depth(inode); 2332 struct ext4_extent *ex; 2333 ext4_lblk_t len; 2334 2335 ex = path[depth].p_ext; 2336 if (ex == NULL) { 2337 /* there is no extent yet, so gap is [0;-] */ 2338 *lblk = 0; 2339 len = EXT_MAX_BLOCKS; 2340 } else if (*lblk < le32_to_cpu(ex->ee_block)) { 2341 len = le32_to_cpu(ex->ee_block) - *lblk; 2342 } else if (*lblk >= le32_to_cpu(ex->ee_block) 2343 + ext4_ext_get_actual_len(ex)) { 2344 ext4_lblk_t next; 2345 2346 *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); 2347 next = ext4_ext_next_allocated_block(path); 2348 BUG_ON(next == *lblk); 2349 len = next - *lblk; 2350 } else { 2351 BUG(); 2352 } 2353 return len; 2354 } 2355 2356 /* 2357 * ext4_ext_put_gap_in_cache: 2358 * calculate boundaries of the gap that the requested block fits into 2359 * and cache this gap 2360 */ 2361 static void 2362 ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start, 2363 ext4_lblk_t hole_len) 2364 { 2365 struct extent_status es; 2366 2367 ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start, 2368 hole_start + hole_len - 1, &es); 2369 if (es.es_len) { 2370 /* There's delayed extent containing lblock? */ 2371 if (es.es_lblk <= hole_start) 2372 return; 2373 hole_len = min(es.es_lblk - hole_start, hole_len); 2374 } 2375 ext_debug(" -> %u:%u\n", hole_start, hole_len); 2376 ext4_es_insert_extent(inode, hole_start, hole_len, ~0, 2377 EXTENT_STATUS_HOLE); 2378 } 2379 2380 /* 2381 * ext4_ext_rm_idx: 2382 * removes index from the index block. 2383 */ 2384 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, 2385 struct ext4_ext_path *path, int depth) 2386 { 2387 int err; 2388 ext4_fsblk_t leaf; 2389 2390 /* free index block */ 2391 depth--; 2392 path = path + depth; 2393 leaf = ext4_idx_pblock(path->p_idx); 2394 if (unlikely(path->p_hdr->eh_entries == 0)) { 2395 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0"); 2396 return -EFSCORRUPTED; 2397 } 2398 err = ext4_ext_get_access(handle, inode, path); 2399 if (err) 2400 return err; 2401 2402 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) { 2403 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx; 2404 len *= sizeof(struct ext4_extent_idx); 2405 memmove(path->p_idx, path->p_idx + 1, len); 2406 } 2407 2408 le16_add_cpu(&path->p_hdr->eh_entries, -1); 2409 err = ext4_ext_dirty(handle, inode, path); 2410 if (err) 2411 return err; 2412 ext_debug("index is empty, remove it, free block %llu\n", leaf); 2413 trace_ext4_ext_rm_idx(inode, leaf); 2414 2415 ext4_free_blocks(handle, inode, NULL, leaf, 1, 2416 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); 2417 2418 while (--depth >= 0) { 2419 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr)) 2420 break; 2421 path--; 2422 err = ext4_ext_get_access(handle, inode, path); 2423 if (err) 2424 break; 2425 path->p_idx->ei_block = (path+1)->p_idx->ei_block; 2426 err = ext4_ext_dirty(handle, inode, path); 2427 if (err) 2428 break; 2429 } 2430 return err; 2431 } 2432 2433 /* 2434 * ext4_ext_calc_credits_for_single_extent: 2435 * This routine returns max. credits that needed to insert an extent 2436 * to the extent tree. 2437 * When pass the actual path, the caller should calculate credits 2438 * under i_data_sem. 2439 */ 2440 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks, 2441 struct ext4_ext_path *path) 2442 { 2443 if (path) { 2444 int depth = ext_depth(inode); 2445 int ret = 0; 2446 2447 /* probably there is space in leaf? */ 2448 if (le16_to_cpu(path[depth].p_hdr->eh_entries) 2449 < le16_to_cpu(path[depth].p_hdr->eh_max)) { 2450 2451 /* 2452 * There are some space in the leaf tree, no 2453 * need to account for leaf block credit 2454 * 2455 * bitmaps and block group descriptor blocks 2456 * and other metadata blocks still need to be 2457 * accounted. 2458 */ 2459 /* 1 bitmap, 1 block group descriptor */ 2460 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb); 2461 return ret; 2462 } 2463 } 2464 2465 return ext4_chunk_trans_blocks(inode, nrblocks); 2466 } 2467 2468 /* 2469 * How many index/leaf blocks need to change/allocate to add @extents extents? 2470 * 2471 * If we add a single extent, then in the worse case, each tree level 2472 * index/leaf need to be changed in case of the tree split. 2473 * 2474 * If more extents are inserted, they could cause the whole tree split more 2475 * than once, but this is really rare. 2476 */ 2477 int ext4_ext_index_trans_blocks(struct inode *inode, int extents) 2478 { 2479 int index; 2480 int depth; 2481 2482 /* If we are converting the inline data, only one is needed here. */ 2483 if (ext4_has_inline_data(inode)) 2484 return 1; 2485 2486 depth = ext_depth(inode); 2487 2488 if (extents <= 1) 2489 index = depth * 2; 2490 else 2491 index = depth * 3; 2492 2493 return index; 2494 } 2495 2496 static inline int get_default_free_blocks_flags(struct inode *inode) 2497 { 2498 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) || 2499 ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE)) 2500 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET; 2501 else if (ext4_should_journal_data(inode)) 2502 return EXT4_FREE_BLOCKS_FORGET; 2503 return 0; 2504 } 2505 2506 /* 2507 * ext4_rereserve_cluster - increment the reserved cluster count when 2508 * freeing a cluster with a pending reservation 2509 * 2510 * @inode - file containing the cluster 2511 * @lblk - logical block in cluster to be reserved 2512 * 2513 * Increments the reserved cluster count and adjusts quota in a bigalloc 2514 * file system when freeing a partial cluster containing at least one 2515 * delayed and unwritten block. A partial cluster meeting that 2516 * requirement will have a pending reservation. If so, the 2517 * RERESERVE_CLUSTER flag is used when calling ext4_free_blocks() to 2518 * defer reserved and allocated space accounting to a subsequent call 2519 * to this function. 2520 */ 2521 static void ext4_rereserve_cluster(struct inode *inode, ext4_lblk_t lblk) 2522 { 2523 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2524 struct ext4_inode_info *ei = EXT4_I(inode); 2525 2526 dquot_reclaim_block(inode, EXT4_C2B(sbi, 1)); 2527 2528 spin_lock(&ei->i_block_reservation_lock); 2529 ei->i_reserved_data_blocks++; 2530 percpu_counter_add(&sbi->s_dirtyclusters_counter, 1); 2531 spin_unlock(&ei->i_block_reservation_lock); 2532 2533 percpu_counter_add(&sbi->s_freeclusters_counter, 1); 2534 ext4_remove_pending(inode, lblk); 2535 } 2536 2537 static int ext4_remove_blocks(handle_t *handle, struct inode *inode, 2538 struct ext4_extent *ex, 2539 struct partial_cluster *partial, 2540 ext4_lblk_t from, ext4_lblk_t to) 2541 { 2542 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2543 unsigned short ee_len = ext4_ext_get_actual_len(ex); 2544 ext4_fsblk_t last_pblk, pblk; 2545 ext4_lblk_t num; 2546 int flags; 2547 2548 /* only extent tail removal is allowed */ 2549 if (from < le32_to_cpu(ex->ee_block) || 2550 to != le32_to_cpu(ex->ee_block) + ee_len - 1) { 2551 ext4_error(sbi->s_sb, 2552 "strange request: removal(2) %u-%u from %u:%u", 2553 from, to, le32_to_cpu(ex->ee_block), ee_len); 2554 return 0; 2555 } 2556 2557 #ifdef EXTENTS_STATS 2558 spin_lock(&sbi->s_ext_stats_lock); 2559 sbi->s_ext_blocks += ee_len; 2560 sbi->s_ext_extents++; 2561 if (ee_len < sbi->s_ext_min) 2562 sbi->s_ext_min = ee_len; 2563 if (ee_len > sbi->s_ext_max) 2564 sbi->s_ext_max = ee_len; 2565 if (ext_depth(inode) > sbi->s_depth_max) 2566 sbi->s_depth_max = ext_depth(inode); 2567 spin_unlock(&sbi->s_ext_stats_lock); 2568 #endif 2569 2570 trace_ext4_remove_blocks(inode, ex, from, to, partial); 2571 2572 /* 2573 * if we have a partial cluster, and it's different from the 2574 * cluster of the last block in the extent, we free it 2575 */ 2576 last_pblk = ext4_ext_pblock(ex) + ee_len - 1; 2577 2578 if (partial->state != initial && 2579 partial->pclu != EXT4_B2C(sbi, last_pblk)) { 2580 if (partial->state == tofree) { 2581 flags = get_default_free_blocks_flags(inode); 2582 if (ext4_is_pending(inode, partial->lblk)) 2583 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; 2584 ext4_free_blocks(handle, inode, NULL, 2585 EXT4_C2B(sbi, partial->pclu), 2586 sbi->s_cluster_ratio, flags); 2587 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) 2588 ext4_rereserve_cluster(inode, partial->lblk); 2589 } 2590 partial->state = initial; 2591 } 2592 2593 num = le32_to_cpu(ex->ee_block) + ee_len - from; 2594 pblk = ext4_ext_pblock(ex) + ee_len - num; 2595 2596 /* 2597 * We free the partial cluster at the end of the extent (if any), 2598 * unless the cluster is used by another extent (partial_cluster 2599 * state is nofree). If a partial cluster exists here, it must be 2600 * shared with the last block in the extent. 2601 */ 2602 flags = get_default_free_blocks_flags(inode); 2603 2604 /* partial, left end cluster aligned, right end unaligned */ 2605 if ((EXT4_LBLK_COFF(sbi, to) != sbi->s_cluster_ratio - 1) && 2606 (EXT4_LBLK_CMASK(sbi, to) >= from) && 2607 (partial->state != nofree)) { 2608 if (ext4_is_pending(inode, to)) 2609 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; 2610 ext4_free_blocks(handle, inode, NULL, 2611 EXT4_PBLK_CMASK(sbi, last_pblk), 2612 sbi->s_cluster_ratio, flags); 2613 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) 2614 ext4_rereserve_cluster(inode, to); 2615 partial->state = initial; 2616 flags = get_default_free_blocks_flags(inode); 2617 } 2618 2619 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER; 2620 2621 /* 2622 * For bigalloc file systems, we never free a partial cluster 2623 * at the beginning of the extent. Instead, we check to see if we 2624 * need to free it on a subsequent call to ext4_remove_blocks, 2625 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space. 2626 */ 2627 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER; 2628 ext4_free_blocks(handle, inode, NULL, pblk, num, flags); 2629 2630 /* reset the partial cluster if we've freed past it */ 2631 if (partial->state != initial && partial->pclu != EXT4_B2C(sbi, pblk)) 2632 partial->state = initial; 2633 2634 /* 2635 * If we've freed the entire extent but the beginning is not left 2636 * cluster aligned and is not marked as ineligible for freeing we 2637 * record the partial cluster at the beginning of the extent. It 2638 * wasn't freed by the preceding ext4_free_blocks() call, and we 2639 * need to look farther to the left to determine if it's to be freed 2640 * (not shared with another extent). Else, reset the partial 2641 * cluster - we're either done freeing or the beginning of the 2642 * extent is left cluster aligned. 2643 */ 2644 if (EXT4_LBLK_COFF(sbi, from) && num == ee_len) { 2645 if (partial->state == initial) { 2646 partial->pclu = EXT4_B2C(sbi, pblk); 2647 partial->lblk = from; 2648 partial->state = tofree; 2649 } 2650 } else { 2651 partial->state = initial; 2652 } 2653 2654 return 0; 2655 } 2656 2657 /* 2658 * ext4_ext_rm_leaf() Removes the extents associated with the 2659 * blocks appearing between "start" and "end". Both "start" 2660 * and "end" must appear in the same extent or EIO is returned. 2661 * 2662 * @handle: The journal handle 2663 * @inode: The files inode 2664 * @path: The path to the leaf 2665 * @partial_cluster: The cluster which we'll have to free if all extents 2666 * has been released from it. However, if this value is 2667 * negative, it's a cluster just to the right of the 2668 * punched region and it must not be freed. 2669 * @start: The first block to remove 2670 * @end: The last block to remove 2671 */ 2672 static int 2673 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, 2674 struct ext4_ext_path *path, 2675 struct partial_cluster *partial, 2676 ext4_lblk_t start, ext4_lblk_t end) 2677 { 2678 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2679 int err = 0, correct_index = 0; 2680 int depth = ext_depth(inode), credits; 2681 struct ext4_extent_header *eh; 2682 ext4_lblk_t a, b; 2683 unsigned num; 2684 ext4_lblk_t ex_ee_block; 2685 unsigned short ex_ee_len; 2686 unsigned unwritten = 0; 2687 struct ext4_extent *ex; 2688 ext4_fsblk_t pblk; 2689 2690 /* the header must be checked already in ext4_ext_remove_space() */ 2691 ext_debug("truncate since %u in leaf to %u\n", start, end); 2692 if (!path[depth].p_hdr) 2693 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); 2694 eh = path[depth].p_hdr; 2695 if (unlikely(path[depth].p_hdr == NULL)) { 2696 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); 2697 return -EFSCORRUPTED; 2698 } 2699 /* find where to start removing */ 2700 ex = path[depth].p_ext; 2701 if (!ex) 2702 ex = EXT_LAST_EXTENT(eh); 2703 2704 ex_ee_block = le32_to_cpu(ex->ee_block); 2705 ex_ee_len = ext4_ext_get_actual_len(ex); 2706 2707 trace_ext4_ext_rm_leaf(inode, start, ex, partial); 2708 2709 while (ex >= EXT_FIRST_EXTENT(eh) && 2710 ex_ee_block + ex_ee_len > start) { 2711 2712 if (ext4_ext_is_unwritten(ex)) 2713 unwritten = 1; 2714 else 2715 unwritten = 0; 2716 2717 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block, 2718 unwritten, ex_ee_len); 2719 path[depth].p_ext = ex; 2720 2721 a = ex_ee_block > start ? ex_ee_block : start; 2722 b = ex_ee_block+ex_ee_len - 1 < end ? 2723 ex_ee_block+ex_ee_len - 1 : end; 2724 2725 ext_debug(" border %u:%u\n", a, b); 2726 2727 /* If this extent is beyond the end of the hole, skip it */ 2728 if (end < ex_ee_block) { 2729 /* 2730 * We're going to skip this extent and move to another, 2731 * so note that its first cluster is in use to avoid 2732 * freeing it when removing blocks. Eventually, the 2733 * right edge of the truncated/punched region will 2734 * be just to the left. 2735 */ 2736 if (sbi->s_cluster_ratio > 1) { 2737 pblk = ext4_ext_pblock(ex); 2738 partial->pclu = EXT4_B2C(sbi, pblk); 2739 partial->state = nofree; 2740 } 2741 ex--; 2742 ex_ee_block = le32_to_cpu(ex->ee_block); 2743 ex_ee_len = ext4_ext_get_actual_len(ex); 2744 continue; 2745 } else if (b != ex_ee_block + ex_ee_len - 1) { 2746 EXT4_ERROR_INODE(inode, 2747 "can not handle truncate %u:%u " 2748 "on extent %u:%u", 2749 start, end, ex_ee_block, 2750 ex_ee_block + ex_ee_len - 1); 2751 err = -EFSCORRUPTED; 2752 goto out; 2753 } else if (a != ex_ee_block) { 2754 /* remove tail of the extent */ 2755 num = a - ex_ee_block; 2756 } else { 2757 /* remove whole extent: excellent! */ 2758 num = 0; 2759 } 2760 /* 2761 * 3 for leaf, sb, and inode plus 2 (bmap and group 2762 * descriptor) for each block group; assume two block 2763 * groups plus ex_ee_len/blocks_per_block_group for 2764 * the worst case 2765 */ 2766 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb)); 2767 if (ex == EXT_FIRST_EXTENT(eh)) { 2768 correct_index = 1; 2769 credits += (ext_depth(inode)) + 1; 2770 } 2771 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb); 2772 2773 err = ext4_ext_truncate_extend_restart(handle, inode, credits); 2774 if (err) 2775 goto out; 2776 2777 err = ext4_ext_get_access(handle, inode, path + depth); 2778 if (err) 2779 goto out; 2780 2781 err = ext4_remove_blocks(handle, inode, ex, partial, a, b); 2782 if (err) 2783 goto out; 2784 2785 if (num == 0) 2786 /* this extent is removed; mark slot entirely unused */ 2787 ext4_ext_store_pblock(ex, 0); 2788 2789 ex->ee_len = cpu_to_le16(num); 2790 /* 2791 * Do not mark unwritten if all the blocks in the 2792 * extent have been removed. 2793 */ 2794 if (unwritten && num) 2795 ext4_ext_mark_unwritten(ex); 2796 /* 2797 * If the extent was completely released, 2798 * we need to remove it from the leaf 2799 */ 2800 if (num == 0) { 2801 if (end != EXT_MAX_BLOCKS - 1) { 2802 /* 2803 * For hole punching, we need to scoot all the 2804 * extents up when an extent is removed so that 2805 * we dont have blank extents in the middle 2806 */ 2807 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) * 2808 sizeof(struct ext4_extent)); 2809 2810 /* Now get rid of the one at the end */ 2811 memset(EXT_LAST_EXTENT(eh), 0, 2812 sizeof(struct ext4_extent)); 2813 } 2814 le16_add_cpu(&eh->eh_entries, -1); 2815 } 2816 2817 err = ext4_ext_dirty(handle, inode, path + depth); 2818 if (err) 2819 goto out; 2820 2821 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num, 2822 ext4_ext_pblock(ex)); 2823 ex--; 2824 ex_ee_block = le32_to_cpu(ex->ee_block); 2825 ex_ee_len = ext4_ext_get_actual_len(ex); 2826 } 2827 2828 if (correct_index && eh->eh_entries) 2829 err = ext4_ext_correct_indexes(handle, inode, path); 2830 2831 /* 2832 * If there's a partial cluster and at least one extent remains in 2833 * the leaf, free the partial cluster if it isn't shared with the 2834 * current extent. If it is shared with the current extent 2835 * we reset the partial cluster because we've reached the start of the 2836 * truncated/punched region and we're done removing blocks. 2837 */ 2838 if (partial->state == tofree && ex >= EXT_FIRST_EXTENT(eh)) { 2839 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1; 2840 if (partial->pclu != EXT4_B2C(sbi, pblk)) { 2841 int flags = get_default_free_blocks_flags(inode); 2842 2843 if (ext4_is_pending(inode, partial->lblk)) 2844 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; 2845 ext4_free_blocks(handle, inode, NULL, 2846 EXT4_C2B(sbi, partial->pclu), 2847 sbi->s_cluster_ratio, flags); 2848 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) 2849 ext4_rereserve_cluster(inode, partial->lblk); 2850 } 2851 partial->state = initial; 2852 } 2853 2854 /* if this leaf is free, then we should 2855 * remove it from index block above */ 2856 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) 2857 err = ext4_ext_rm_idx(handle, inode, path, depth); 2858 2859 out: 2860 return err; 2861 } 2862 2863 /* 2864 * ext4_ext_more_to_rm: 2865 * returns 1 if current index has to be freed (even partial) 2866 */ 2867 static int 2868 ext4_ext_more_to_rm(struct ext4_ext_path *path) 2869 { 2870 BUG_ON(path->p_idx == NULL); 2871 2872 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) 2873 return 0; 2874 2875 /* 2876 * if truncate on deeper level happened, it wasn't partial, 2877 * so we have to consider current index for truncation 2878 */ 2879 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) 2880 return 0; 2881 return 1; 2882 } 2883 2884 int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, 2885 ext4_lblk_t end) 2886 { 2887 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2888 int depth = ext_depth(inode); 2889 struct ext4_ext_path *path = NULL; 2890 struct partial_cluster partial; 2891 handle_t *handle; 2892 int i = 0, err = 0; 2893 2894 partial.pclu = 0; 2895 partial.lblk = 0; 2896 partial.state = initial; 2897 2898 ext_debug("truncate since %u to %u\n", start, end); 2899 2900 /* probably first extent we're gonna free will be last in block */ 2901 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1); 2902 if (IS_ERR(handle)) 2903 return PTR_ERR(handle); 2904 2905 again: 2906 trace_ext4_ext_remove_space(inode, start, end, depth); 2907 2908 /* 2909 * Check if we are removing extents inside the extent tree. If that 2910 * is the case, we are going to punch a hole inside the extent tree 2911 * so we have to check whether we need to split the extent covering 2912 * the last block to remove so we can easily remove the part of it 2913 * in ext4_ext_rm_leaf(). 2914 */ 2915 if (end < EXT_MAX_BLOCKS - 1) { 2916 struct ext4_extent *ex; 2917 ext4_lblk_t ee_block, ex_end, lblk; 2918 ext4_fsblk_t pblk; 2919 2920 /* find extent for or closest extent to this block */ 2921 path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE); 2922 if (IS_ERR(path)) { 2923 ext4_journal_stop(handle); 2924 return PTR_ERR(path); 2925 } 2926 depth = ext_depth(inode); 2927 /* Leaf not may not exist only if inode has no blocks at all */ 2928 ex = path[depth].p_ext; 2929 if (!ex) { 2930 if (depth) { 2931 EXT4_ERROR_INODE(inode, 2932 "path[%d].p_hdr == NULL", 2933 depth); 2934 err = -EFSCORRUPTED; 2935 } 2936 goto out; 2937 } 2938 2939 ee_block = le32_to_cpu(ex->ee_block); 2940 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1; 2941 2942 /* 2943 * See if the last block is inside the extent, if so split 2944 * the extent at 'end' block so we can easily remove the 2945 * tail of the first part of the split extent in 2946 * ext4_ext_rm_leaf(). 2947 */ 2948 if (end >= ee_block && end < ex_end) { 2949 2950 /* 2951 * If we're going to split the extent, note that 2952 * the cluster containing the block after 'end' is 2953 * in use to avoid freeing it when removing blocks. 2954 */ 2955 if (sbi->s_cluster_ratio > 1) { 2956 pblk = ext4_ext_pblock(ex) + end - ee_block + 2; 2957 partial.pclu = EXT4_B2C(sbi, pblk); 2958 partial.state = nofree; 2959 } 2960 2961 /* 2962 * Split the extent in two so that 'end' is the last 2963 * block in the first new extent. Also we should not 2964 * fail removing space due to ENOSPC so try to use 2965 * reserved block if that happens. 2966 */ 2967 err = ext4_force_split_extent_at(handle, inode, &path, 2968 end + 1, 1); 2969 if (err < 0) 2970 goto out; 2971 2972 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end && 2973 partial.state == initial) { 2974 /* 2975 * If we're punching, there's an extent to the right. 2976 * If the partial cluster hasn't been set, set it to 2977 * that extent's first cluster and its state to nofree 2978 * so it won't be freed should it contain blocks to be 2979 * removed. If it's already set (tofree/nofree), we're 2980 * retrying and keep the original partial cluster info 2981 * so a cluster marked tofree as a result of earlier 2982 * extent removal is not lost. 2983 */ 2984 lblk = ex_end + 1; 2985 err = ext4_ext_search_right(inode, path, &lblk, &pblk, 2986 &ex); 2987 if (err) 2988 goto out; 2989 if (pblk) { 2990 partial.pclu = EXT4_B2C(sbi, pblk); 2991 partial.state = nofree; 2992 } 2993 } 2994 } 2995 /* 2996 * We start scanning from right side, freeing all the blocks 2997 * after i_size and walking into the tree depth-wise. 2998 */ 2999 depth = ext_depth(inode); 3000 if (path) { 3001 int k = i = depth; 3002 while (--k > 0) 3003 path[k].p_block = 3004 le16_to_cpu(path[k].p_hdr->eh_entries)+1; 3005 } else { 3006 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path), 3007 GFP_NOFS); 3008 if (path == NULL) { 3009 ext4_journal_stop(handle); 3010 return -ENOMEM; 3011 } 3012 path[0].p_maxdepth = path[0].p_depth = depth; 3013 path[0].p_hdr = ext_inode_hdr(inode); 3014 i = 0; 3015 3016 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) { 3017 err = -EFSCORRUPTED; 3018 goto out; 3019 } 3020 } 3021 err = 0; 3022 3023 while (i >= 0 && err == 0) { 3024 if (i == depth) { 3025 /* this is leaf block */ 3026 err = ext4_ext_rm_leaf(handle, inode, path, 3027 &partial, start, end); 3028 /* root level has p_bh == NULL, brelse() eats this */ 3029 brelse(path[i].p_bh); 3030 path[i].p_bh = NULL; 3031 i--; 3032 continue; 3033 } 3034 3035 /* this is index block */ 3036 if (!path[i].p_hdr) { 3037 ext_debug("initialize header\n"); 3038 path[i].p_hdr = ext_block_hdr(path[i].p_bh); 3039 } 3040 3041 if (!path[i].p_idx) { 3042 /* this level hasn't been touched yet */ 3043 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); 3044 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; 3045 ext_debug("init index ptr: hdr 0x%p, num %d\n", 3046 path[i].p_hdr, 3047 le16_to_cpu(path[i].p_hdr->eh_entries)); 3048 } else { 3049 /* we were already here, see at next index */ 3050 path[i].p_idx--; 3051 } 3052 3053 ext_debug("level %d - index, first 0x%p, cur 0x%p\n", 3054 i, EXT_FIRST_INDEX(path[i].p_hdr), 3055 path[i].p_idx); 3056 if (ext4_ext_more_to_rm(path + i)) { 3057 struct buffer_head *bh; 3058 /* go to the next level */ 3059 ext_debug("move to level %d (block %llu)\n", 3060 i + 1, ext4_idx_pblock(path[i].p_idx)); 3061 memset(path + i + 1, 0, sizeof(*path)); 3062 bh = read_extent_tree_block(inode, 3063 ext4_idx_pblock(path[i].p_idx), depth - i - 1, 3064 EXT4_EX_NOCACHE); 3065 if (IS_ERR(bh)) { 3066 /* should we reset i_size? */ 3067 err = PTR_ERR(bh); 3068 break; 3069 } 3070 /* Yield here to deal with large extent trees. 3071 * Should be a no-op if we did IO above. */ 3072 cond_resched(); 3073 if (WARN_ON(i + 1 > depth)) { 3074 err = -EFSCORRUPTED; 3075 break; 3076 } 3077 path[i + 1].p_bh = bh; 3078 3079 /* save actual number of indexes since this 3080 * number is changed at the next iteration */ 3081 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); 3082 i++; 3083 } else { 3084 /* we finished processing this index, go up */ 3085 if (path[i].p_hdr->eh_entries == 0 && i > 0) { 3086 /* index is empty, remove it; 3087 * handle must be already prepared by the 3088 * truncatei_leaf() */ 3089 err = ext4_ext_rm_idx(handle, inode, path, i); 3090 } 3091 /* root level has p_bh == NULL, brelse() eats this */ 3092 brelse(path[i].p_bh); 3093 path[i].p_bh = NULL; 3094 i--; 3095 ext_debug("return to level %d\n", i); 3096 } 3097 } 3098 3099 trace_ext4_ext_remove_space_done(inode, start, end, depth, &partial, 3100 path->p_hdr->eh_entries); 3101 3102 /* 3103 * if there's a partial cluster and we have removed the first extent 3104 * in the file, then we also free the partial cluster, if any 3105 */ 3106 if (partial.state == tofree && err == 0) { 3107 int flags = get_default_free_blocks_flags(inode); 3108 3109 if (ext4_is_pending(inode, partial.lblk)) 3110 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; 3111 ext4_free_blocks(handle, inode, NULL, 3112 EXT4_C2B(sbi, partial.pclu), 3113 sbi->s_cluster_ratio, flags); 3114 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) 3115 ext4_rereserve_cluster(inode, partial.lblk); 3116 partial.state = initial; 3117 } 3118 3119 /* TODO: flexible tree reduction should be here */ 3120 if (path->p_hdr->eh_entries == 0) { 3121 /* 3122 * truncate to zero freed all the tree, 3123 * so we need to correct eh_depth 3124 */ 3125 err = ext4_ext_get_access(handle, inode, path); 3126 if (err == 0) { 3127 ext_inode_hdr(inode)->eh_depth = 0; 3128 ext_inode_hdr(inode)->eh_max = 3129 cpu_to_le16(ext4_ext_space_root(inode, 0)); 3130 err = ext4_ext_dirty(handle, inode, path); 3131 } 3132 } 3133 out: 3134 ext4_ext_drop_refs(path); 3135 kfree(path); 3136 path = NULL; 3137 if (err == -EAGAIN) 3138 goto again; 3139 ext4_journal_stop(handle); 3140 3141 return err; 3142 } 3143 3144 /* 3145 * called at mount time 3146 */ 3147 void ext4_ext_init(struct super_block *sb) 3148 { 3149 /* 3150 * possible initialization would be here 3151 */ 3152 3153 if (ext4_has_feature_extents(sb)) { 3154 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS) 3155 printk(KERN_INFO "EXT4-fs: file extents enabled" 3156 #ifdef AGGRESSIVE_TEST 3157 ", aggressive tests" 3158 #endif 3159 #ifdef CHECK_BINSEARCH 3160 ", check binsearch" 3161 #endif 3162 #ifdef EXTENTS_STATS 3163 ", stats" 3164 #endif 3165 "\n"); 3166 #endif 3167 #ifdef EXTENTS_STATS 3168 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); 3169 EXT4_SB(sb)->s_ext_min = 1 << 30; 3170 EXT4_SB(sb)->s_ext_max = 0; 3171 #endif 3172 } 3173 } 3174 3175 /* 3176 * called at umount time 3177 */ 3178 void ext4_ext_release(struct super_block *sb) 3179 { 3180 if (!ext4_has_feature_extents(sb)) 3181 return; 3182 3183 #ifdef EXTENTS_STATS 3184 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { 3185 struct ext4_sb_info *sbi = EXT4_SB(sb); 3186 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", 3187 sbi->s_ext_blocks, sbi->s_ext_extents, 3188 sbi->s_ext_blocks / sbi->s_ext_extents); 3189 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", 3190 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); 3191 } 3192 #endif 3193 } 3194 3195 static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex) 3196 { 3197 ext4_lblk_t ee_block; 3198 ext4_fsblk_t ee_pblock; 3199 unsigned int ee_len; 3200 3201 ee_block = le32_to_cpu(ex->ee_block); 3202 ee_len = ext4_ext_get_actual_len(ex); 3203 ee_pblock = ext4_ext_pblock(ex); 3204 3205 if (ee_len == 0) 3206 return 0; 3207 3208 return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock, 3209 EXTENT_STATUS_WRITTEN); 3210 } 3211 3212 /* FIXME!! we need to try to merge to left or right after zero-out */ 3213 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) 3214 { 3215 ext4_fsblk_t ee_pblock; 3216 unsigned int ee_len; 3217 3218 ee_len = ext4_ext_get_actual_len(ex); 3219 ee_pblock = ext4_ext_pblock(ex); 3220 return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock, 3221 ee_len); 3222 } 3223 3224 /* 3225 * ext4_split_extent_at() splits an extent at given block. 3226 * 3227 * @handle: the journal handle 3228 * @inode: the file inode 3229 * @path: the path to the extent 3230 * @split: the logical block where the extent is splitted. 3231 * @split_flags: indicates if the extent could be zeroout if split fails, and 3232 * the states(init or unwritten) of new extents. 3233 * @flags: flags used to insert new extent to extent tree. 3234 * 3235 * 3236 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states 3237 * of which are deterimined by split_flag. 3238 * 3239 * There are two cases: 3240 * a> the extent are splitted into two extent. 3241 * b> split is not needed, and just mark the extent. 3242 * 3243 * return 0 on success. 3244 */ 3245 static int ext4_split_extent_at(handle_t *handle, 3246 struct inode *inode, 3247 struct ext4_ext_path **ppath, 3248 ext4_lblk_t split, 3249 int split_flag, 3250 int flags) 3251 { 3252 struct ext4_ext_path *path = *ppath; 3253 ext4_fsblk_t newblock; 3254 ext4_lblk_t ee_block; 3255 struct ext4_extent *ex, newex, orig_ex, zero_ex; 3256 struct ext4_extent *ex2 = NULL; 3257 unsigned int ee_len, depth; 3258 int err = 0; 3259 3260 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) == 3261 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)); 3262 3263 ext_debug("ext4_split_extents_at: inode %lu, logical" 3264 "block %llu\n", inode->i_ino, (unsigned long long)split); 3265 3266 ext4_ext_show_leaf(inode, path); 3267 3268 depth = ext_depth(inode); 3269 ex = path[depth].p_ext; 3270 ee_block = le32_to_cpu(ex->ee_block); 3271 ee_len = ext4_ext_get_actual_len(ex); 3272 newblock = split - ee_block + ext4_ext_pblock(ex); 3273 3274 BUG_ON(split < ee_block || split >= (ee_block + ee_len)); 3275 BUG_ON(!ext4_ext_is_unwritten(ex) && 3276 split_flag & (EXT4_EXT_MAY_ZEROOUT | 3277 EXT4_EXT_MARK_UNWRIT1 | 3278 EXT4_EXT_MARK_UNWRIT2)); 3279 3280 err = ext4_ext_get_access(handle, inode, path + depth); 3281 if (err) 3282 goto out; 3283 3284 if (split == ee_block) { 3285 /* 3286 * case b: block @split is the block that the extent begins with 3287 * then we just change the state of the extent, and splitting 3288 * is not needed. 3289 */ 3290 if (split_flag & EXT4_EXT_MARK_UNWRIT2) 3291 ext4_ext_mark_unwritten(ex); 3292 else 3293 ext4_ext_mark_initialized(ex); 3294 3295 if (!(flags & EXT4_GET_BLOCKS_PRE_IO)) 3296 ext4_ext_try_to_merge(handle, inode, path, ex); 3297 3298 err = ext4_ext_dirty(handle, inode, path + path->p_depth); 3299 goto out; 3300 } 3301 3302 /* case a */ 3303 memcpy(&orig_ex, ex, sizeof(orig_ex)); 3304 ex->ee_len = cpu_to_le16(split - ee_block); 3305 if (split_flag & EXT4_EXT_MARK_UNWRIT1) 3306 ext4_ext_mark_unwritten(ex); 3307 3308 /* 3309 * path may lead to new leaf, not to original leaf any more 3310 * after ext4_ext_insert_extent() returns, 3311 */ 3312 err = ext4_ext_dirty(handle, inode, path + depth); 3313 if (err) 3314 goto fix_extent_len; 3315 3316 ex2 = &newex; 3317 ex2->ee_block = cpu_to_le32(split); 3318 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block)); 3319 ext4_ext_store_pblock(ex2, newblock); 3320 if (split_flag & EXT4_EXT_MARK_UNWRIT2) 3321 ext4_ext_mark_unwritten(ex2); 3322 3323 err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags); 3324 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) { 3325 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) { 3326 if (split_flag & EXT4_EXT_DATA_VALID1) { 3327 err = ext4_ext_zeroout(inode, ex2); 3328 zero_ex.ee_block = ex2->ee_block; 3329 zero_ex.ee_len = cpu_to_le16( 3330 ext4_ext_get_actual_len(ex2)); 3331 ext4_ext_store_pblock(&zero_ex, 3332 ext4_ext_pblock(ex2)); 3333 } else { 3334 err = ext4_ext_zeroout(inode, ex); 3335 zero_ex.ee_block = ex->ee_block; 3336 zero_ex.ee_len = cpu_to_le16( 3337 ext4_ext_get_actual_len(ex)); 3338 ext4_ext_store_pblock(&zero_ex, 3339 ext4_ext_pblock(ex)); 3340 } 3341 } else { 3342 err = ext4_ext_zeroout(inode, &orig_ex); 3343 zero_ex.ee_block = orig_ex.ee_block; 3344 zero_ex.ee_len = cpu_to_le16( 3345 ext4_ext_get_actual_len(&orig_ex)); 3346 ext4_ext_store_pblock(&zero_ex, 3347 ext4_ext_pblock(&orig_ex)); 3348 } 3349 3350 if (err) 3351 goto fix_extent_len; 3352 /* update the extent length and mark as initialized */ 3353 ex->ee_len = cpu_to_le16(ee_len); 3354 ext4_ext_try_to_merge(handle, inode, path, ex); 3355 err = ext4_ext_dirty(handle, inode, path + path->p_depth); 3356 if (err) 3357 goto fix_extent_len; 3358 3359 /* update extent status tree */ 3360 err = ext4_zeroout_es(inode, &zero_ex); 3361 3362 goto out; 3363 } else if (err) 3364 goto fix_extent_len; 3365 3366 out: 3367 ext4_ext_show_leaf(inode, path); 3368 return err; 3369 3370 fix_extent_len: 3371 ex->ee_len = orig_ex.ee_len; 3372 ext4_ext_dirty(handle, inode, path + path->p_depth); 3373 return err; 3374 } 3375 3376 /* 3377 * ext4_split_extents() splits an extent and mark extent which is covered 3378 * by @map as split_flags indicates 3379 * 3380 * It may result in splitting the extent into multiple extents (up to three) 3381 * There are three possibilities: 3382 * a> There is no split required 3383 * b> Splits in two extents: Split is happening at either end of the extent 3384 * c> Splits in three extents: Somone is splitting in middle of the extent 3385 * 3386 */ 3387 static int ext4_split_extent(handle_t *handle, 3388 struct inode *inode, 3389 struct ext4_ext_path **ppath, 3390 struct ext4_map_blocks *map, 3391 int split_flag, 3392 int flags) 3393 { 3394 struct ext4_ext_path *path = *ppath; 3395 ext4_lblk_t ee_block; 3396 struct ext4_extent *ex; 3397 unsigned int ee_len, depth; 3398 int err = 0; 3399 int unwritten; 3400 int split_flag1, flags1; 3401 int allocated = map->m_len; 3402 3403 depth = ext_depth(inode); 3404 ex = path[depth].p_ext; 3405 ee_block = le32_to_cpu(ex->ee_block); 3406 ee_len = ext4_ext_get_actual_len(ex); 3407 unwritten = ext4_ext_is_unwritten(ex); 3408 3409 if (map->m_lblk + map->m_len < ee_block + ee_len) { 3410 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT; 3411 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO; 3412 if (unwritten) 3413 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 | 3414 EXT4_EXT_MARK_UNWRIT2; 3415 if (split_flag & EXT4_EXT_DATA_VALID2) 3416 split_flag1 |= EXT4_EXT_DATA_VALID1; 3417 err = ext4_split_extent_at(handle, inode, ppath, 3418 map->m_lblk + map->m_len, split_flag1, flags1); 3419 if (err) 3420 goto out; 3421 } else { 3422 allocated = ee_len - (map->m_lblk - ee_block); 3423 } 3424 /* 3425 * Update path is required because previous ext4_split_extent_at() may 3426 * result in split of original leaf or extent zeroout. 3427 */ 3428 path = ext4_find_extent(inode, map->m_lblk, ppath, 0); 3429 if (IS_ERR(path)) 3430 return PTR_ERR(path); 3431 depth = ext_depth(inode); 3432 ex = path[depth].p_ext; 3433 if (!ex) { 3434 EXT4_ERROR_INODE(inode, "unexpected hole at %lu", 3435 (unsigned long) map->m_lblk); 3436 return -EFSCORRUPTED; 3437 } 3438 unwritten = ext4_ext_is_unwritten(ex); 3439 split_flag1 = 0; 3440 3441 if (map->m_lblk >= ee_block) { 3442 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2; 3443 if (unwritten) { 3444 split_flag1 |= EXT4_EXT_MARK_UNWRIT1; 3445 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT | 3446 EXT4_EXT_MARK_UNWRIT2); 3447 } 3448 err = ext4_split_extent_at(handle, inode, ppath, 3449 map->m_lblk, split_flag1, flags); 3450 if (err) 3451 goto out; 3452 } 3453 3454 ext4_ext_show_leaf(inode, path); 3455 out: 3456 return err ? err : allocated; 3457 } 3458 3459 /* 3460 * This function is called by ext4_ext_map_blocks() if someone tries to write 3461 * to an unwritten extent. It may result in splitting the unwritten 3462 * extent into multiple extents (up to three - one initialized and two 3463 * unwritten). 3464 * There are three possibilities: 3465 * a> There is no split required: Entire extent should be initialized 3466 * b> Splits in two extents: Write is happening at either end of the extent 3467 * c> Splits in three extents: Somone is writing in middle of the extent 3468 * 3469 * Pre-conditions: 3470 * - The extent pointed to by 'path' is unwritten. 3471 * - The extent pointed to by 'path' contains a superset 3472 * of the logical span [map->m_lblk, map->m_lblk + map->m_len). 3473 * 3474 * Post-conditions on success: 3475 * - the returned value is the number of blocks beyond map->l_lblk 3476 * that are allocated and initialized. 3477 * It is guaranteed to be >= map->m_len. 3478 */ 3479 static int ext4_ext_convert_to_initialized(handle_t *handle, 3480 struct inode *inode, 3481 struct ext4_map_blocks *map, 3482 struct ext4_ext_path **ppath, 3483 int flags) 3484 { 3485 struct ext4_ext_path *path = *ppath; 3486 struct ext4_sb_info *sbi; 3487 struct ext4_extent_header *eh; 3488 struct ext4_map_blocks split_map; 3489 struct ext4_extent zero_ex1, zero_ex2; 3490 struct ext4_extent *ex, *abut_ex; 3491 ext4_lblk_t ee_block, eof_block; 3492 unsigned int ee_len, depth, map_len = map->m_len; 3493 int allocated = 0, max_zeroout = 0; 3494 int err = 0; 3495 int split_flag = EXT4_EXT_DATA_VALID2; 3496 3497 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical" 3498 "block %llu, max_blocks %u\n", inode->i_ino, 3499 (unsigned long long)map->m_lblk, map_len); 3500 3501 sbi = EXT4_SB(inode->i_sb); 3502 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> 3503 inode->i_sb->s_blocksize_bits; 3504 if (eof_block < map->m_lblk + map_len) 3505 eof_block = map->m_lblk + map_len; 3506 3507 depth = ext_depth(inode); 3508 eh = path[depth].p_hdr; 3509 ex = path[depth].p_ext; 3510 ee_block = le32_to_cpu(ex->ee_block); 3511 ee_len = ext4_ext_get_actual_len(ex); 3512 zero_ex1.ee_len = 0; 3513 zero_ex2.ee_len = 0; 3514 3515 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex); 3516 3517 /* Pre-conditions */ 3518 BUG_ON(!ext4_ext_is_unwritten(ex)); 3519 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len)); 3520 3521 /* 3522 * Attempt to transfer newly initialized blocks from the currently 3523 * unwritten extent to its neighbor. This is much cheaper 3524 * than an insertion followed by a merge as those involve costly 3525 * memmove() calls. Transferring to the left is the common case in 3526 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE) 3527 * followed by append writes. 3528 * 3529 * Limitations of the current logic: 3530 * - L1: we do not deal with writes covering the whole extent. 3531 * This would require removing the extent if the transfer 3532 * is possible. 3533 * - L2: we only attempt to merge with an extent stored in the 3534 * same extent tree node. 3535 */ 3536 if ((map->m_lblk == ee_block) && 3537 /* See if we can merge left */ 3538 (map_len < ee_len) && /*L1*/ 3539 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/ 3540 ext4_lblk_t prev_lblk; 3541 ext4_fsblk_t prev_pblk, ee_pblk; 3542 unsigned int prev_len; 3543 3544 abut_ex = ex - 1; 3545 prev_lblk = le32_to_cpu(abut_ex->ee_block); 3546 prev_len = ext4_ext_get_actual_len(abut_ex); 3547 prev_pblk = ext4_ext_pblock(abut_ex); 3548 ee_pblk = ext4_ext_pblock(ex); 3549 3550 /* 3551 * A transfer of blocks from 'ex' to 'abut_ex' is allowed 3552 * upon those conditions: 3553 * - C1: abut_ex is initialized, 3554 * - C2: abut_ex is logically abutting ex, 3555 * - C3: abut_ex is physically abutting ex, 3556 * - C4: abut_ex can receive the additional blocks without 3557 * overflowing the (initialized) length limit. 3558 */ 3559 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/ 3560 ((prev_lblk + prev_len) == ee_block) && /*C2*/ 3561 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/ 3562 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/ 3563 err = ext4_ext_get_access(handle, inode, path + depth); 3564 if (err) 3565 goto out; 3566 3567 trace_ext4_ext_convert_to_initialized_fastpath(inode, 3568 map, ex, abut_ex); 3569 3570 /* Shift the start of ex by 'map_len' blocks */ 3571 ex->ee_block = cpu_to_le32(ee_block + map_len); 3572 ext4_ext_store_pblock(ex, ee_pblk + map_len); 3573 ex->ee_len = cpu_to_le16(ee_len - map_len); 3574 ext4_ext_mark_unwritten(ex); /* Restore the flag */ 3575 3576 /* Extend abut_ex by 'map_len' blocks */ 3577 abut_ex->ee_len = cpu_to_le16(prev_len + map_len); 3578 3579 /* Result: number of initialized blocks past m_lblk */ 3580 allocated = map_len; 3581 } 3582 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) && 3583 (map_len < ee_len) && /*L1*/ 3584 ex < EXT_LAST_EXTENT(eh)) { /*L2*/ 3585 /* See if we can merge right */ 3586 ext4_lblk_t next_lblk; 3587 ext4_fsblk_t next_pblk, ee_pblk; 3588 unsigned int next_len; 3589 3590 abut_ex = ex + 1; 3591 next_lblk = le32_to_cpu(abut_ex->ee_block); 3592 next_len = ext4_ext_get_actual_len(abut_ex); 3593 next_pblk = ext4_ext_pblock(abut_ex); 3594 ee_pblk = ext4_ext_pblock(ex); 3595 3596 /* 3597 * A transfer of blocks from 'ex' to 'abut_ex' is allowed 3598 * upon those conditions: 3599 * - C1: abut_ex is initialized, 3600 * - C2: abut_ex is logically abutting ex, 3601 * - C3: abut_ex is physically abutting ex, 3602 * - C4: abut_ex can receive the additional blocks without 3603 * overflowing the (initialized) length limit. 3604 */ 3605 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/ 3606 ((map->m_lblk + map_len) == next_lblk) && /*C2*/ 3607 ((ee_pblk + ee_len) == next_pblk) && /*C3*/ 3608 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/ 3609 err = ext4_ext_get_access(handle, inode, path + depth); 3610 if (err) 3611 goto out; 3612 3613 trace_ext4_ext_convert_to_initialized_fastpath(inode, 3614 map, ex, abut_ex); 3615 3616 /* Shift the start of abut_ex by 'map_len' blocks */ 3617 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len); 3618 ext4_ext_store_pblock(abut_ex, next_pblk - map_len); 3619 ex->ee_len = cpu_to_le16(ee_len - map_len); 3620 ext4_ext_mark_unwritten(ex); /* Restore the flag */ 3621 3622 /* Extend abut_ex by 'map_len' blocks */ 3623 abut_ex->ee_len = cpu_to_le16(next_len + map_len); 3624 3625 /* Result: number of initialized blocks past m_lblk */ 3626 allocated = map_len; 3627 } 3628 } 3629 if (allocated) { 3630 /* Mark the block containing both extents as dirty */ 3631 ext4_ext_dirty(handle, inode, path + depth); 3632 3633 /* Update path to point to the right extent */ 3634 path[depth].p_ext = abut_ex; 3635 goto out; 3636 } else 3637 allocated = ee_len - (map->m_lblk - ee_block); 3638 3639 WARN_ON(map->m_lblk < ee_block); 3640 /* 3641 * It is safe to convert extent to initialized via explicit 3642 * zeroout only if extent is fully inside i_size or new_size. 3643 */ 3644 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; 3645 3646 if (EXT4_EXT_MAY_ZEROOUT & split_flag) 3647 max_zeroout = sbi->s_extent_max_zeroout_kb >> 3648 (inode->i_sb->s_blocksize_bits - 10); 3649 3650 if (IS_ENCRYPTED(inode)) 3651 max_zeroout = 0; 3652 3653 /* 3654 * five cases: 3655 * 1. split the extent into three extents. 3656 * 2. split the extent into two extents, zeroout the head of the first 3657 * extent. 3658 * 3. split the extent into two extents, zeroout the tail of the second 3659 * extent. 3660 * 4. split the extent into two extents with out zeroout. 3661 * 5. no splitting needed, just possibly zeroout the head and / or the 3662 * tail of the extent. 3663 */ 3664 split_map.m_lblk = map->m_lblk; 3665 split_map.m_len = map->m_len; 3666 3667 if (max_zeroout && (allocated > split_map.m_len)) { 3668 if (allocated <= max_zeroout) { 3669 /* case 3 or 5 */ 3670 zero_ex1.ee_block = 3671 cpu_to_le32(split_map.m_lblk + 3672 split_map.m_len); 3673 zero_ex1.ee_len = 3674 cpu_to_le16(allocated - split_map.m_len); 3675 ext4_ext_store_pblock(&zero_ex1, 3676 ext4_ext_pblock(ex) + split_map.m_lblk + 3677 split_map.m_len - ee_block); 3678 err = ext4_ext_zeroout(inode, &zero_ex1); 3679 if (err) 3680 goto out; 3681 split_map.m_len = allocated; 3682 } 3683 if (split_map.m_lblk - ee_block + split_map.m_len < 3684 max_zeroout) { 3685 /* case 2 or 5 */ 3686 if (split_map.m_lblk != ee_block) { 3687 zero_ex2.ee_block = ex->ee_block; 3688 zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk - 3689 ee_block); 3690 ext4_ext_store_pblock(&zero_ex2, 3691 ext4_ext_pblock(ex)); 3692 err = ext4_ext_zeroout(inode, &zero_ex2); 3693 if (err) 3694 goto out; 3695 } 3696 3697 split_map.m_len += split_map.m_lblk - ee_block; 3698 split_map.m_lblk = ee_block; 3699 allocated = map->m_len; 3700 } 3701 } 3702 3703 err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag, 3704 flags); 3705 if (err > 0) 3706 err = 0; 3707 out: 3708 /* If we have gotten a failure, don't zero out status tree */ 3709 if (!err) { 3710 err = ext4_zeroout_es(inode, &zero_ex1); 3711 if (!err) 3712 err = ext4_zeroout_es(inode, &zero_ex2); 3713 } 3714 return err ? err : allocated; 3715 } 3716 3717 /* 3718 * This function is called by ext4_ext_map_blocks() from 3719 * ext4_get_blocks_dio_write() when DIO to write 3720 * to an unwritten extent. 3721 * 3722 * Writing to an unwritten extent may result in splitting the unwritten 3723 * extent into multiple initialized/unwritten extents (up to three) 3724 * There are three possibilities: 3725 * a> There is no split required: Entire extent should be unwritten 3726 * b> Splits in two extents: Write is happening at either end of the extent 3727 * c> Splits in three extents: Somone is writing in middle of the extent 3728 * 3729 * This works the same way in the case of initialized -> unwritten conversion. 3730 * 3731 * One of more index blocks maybe needed if the extent tree grow after 3732 * the unwritten extent split. To prevent ENOSPC occur at the IO 3733 * complete, we need to split the unwritten extent before DIO submit 3734 * the IO. The unwritten extent called at this time will be split 3735 * into three unwritten extent(at most). After IO complete, the part 3736 * being filled will be convert to initialized by the end_io callback function 3737 * via ext4_convert_unwritten_extents(). 3738 * 3739 * Returns the size of unwritten extent to be written on success. 3740 */ 3741 static int ext4_split_convert_extents(handle_t *handle, 3742 struct inode *inode, 3743 struct ext4_map_blocks *map, 3744 struct ext4_ext_path **ppath, 3745 int flags) 3746 { 3747 struct ext4_ext_path *path = *ppath; 3748 ext4_lblk_t eof_block; 3749 ext4_lblk_t ee_block; 3750 struct ext4_extent *ex; 3751 unsigned int ee_len; 3752 int split_flag = 0, depth; 3753 3754 ext_debug("%s: inode %lu, logical block %llu, max_blocks %u\n", 3755 __func__, inode->i_ino, 3756 (unsigned long long)map->m_lblk, map->m_len); 3757 3758 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> 3759 inode->i_sb->s_blocksize_bits; 3760 if (eof_block < map->m_lblk + map->m_len) 3761 eof_block = map->m_lblk + map->m_len; 3762 /* 3763 * It is safe to convert extent to initialized via explicit 3764 * zeroout only if extent is fully insde i_size or new_size. 3765 */ 3766 depth = ext_depth(inode); 3767 ex = path[depth].p_ext; 3768 ee_block = le32_to_cpu(ex->ee_block); 3769 ee_len = ext4_ext_get_actual_len(ex); 3770 3771 /* Convert to unwritten */ 3772 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) { 3773 split_flag |= EXT4_EXT_DATA_VALID1; 3774 /* Convert to initialized */ 3775 } else if (flags & EXT4_GET_BLOCKS_CONVERT) { 3776 split_flag |= ee_block + ee_len <= eof_block ? 3777 EXT4_EXT_MAY_ZEROOUT : 0; 3778 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2); 3779 } 3780 flags |= EXT4_GET_BLOCKS_PRE_IO; 3781 return ext4_split_extent(handle, inode, ppath, map, split_flag, flags); 3782 } 3783 3784 static int ext4_convert_unwritten_extents_endio(handle_t *handle, 3785 struct inode *inode, 3786 struct ext4_map_blocks *map, 3787 struct ext4_ext_path **ppath) 3788 { 3789 struct ext4_ext_path *path = *ppath; 3790 struct ext4_extent *ex; 3791 ext4_lblk_t ee_block; 3792 unsigned int ee_len; 3793 int depth; 3794 int err = 0; 3795 3796 depth = ext_depth(inode); 3797 ex = path[depth].p_ext; 3798 ee_block = le32_to_cpu(ex->ee_block); 3799 ee_len = ext4_ext_get_actual_len(ex); 3800 3801 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical" 3802 "block %llu, max_blocks %u\n", inode->i_ino, 3803 (unsigned long long)ee_block, ee_len); 3804 3805 /* If extent is larger than requested it is a clear sign that we still 3806 * have some extent state machine issues left. So extent_split is still 3807 * required. 3808 * TODO: Once all related issues will be fixed this situation should be 3809 * illegal. 3810 */ 3811 if (ee_block != map->m_lblk || ee_len > map->m_len) { 3812 #ifdef EXT4_DEBUG 3813 ext4_warning("Inode (%ld) finished: extent logical block %llu," 3814 " len %u; IO logical block %llu, len %u", 3815 inode->i_ino, (unsigned long long)ee_block, ee_len, 3816 (unsigned long long)map->m_lblk, map->m_len); 3817 #endif 3818 err = ext4_split_convert_extents(handle, inode, map, ppath, 3819 EXT4_GET_BLOCKS_CONVERT); 3820 if (err < 0) 3821 return err; 3822 path = ext4_find_extent(inode, map->m_lblk, ppath, 0); 3823 if (IS_ERR(path)) 3824 return PTR_ERR(path); 3825 depth = ext_depth(inode); 3826 ex = path[depth].p_ext; 3827 } 3828 3829 err = ext4_ext_get_access(handle, inode, path + depth); 3830 if (err) 3831 goto out; 3832 /* first mark the extent as initialized */ 3833 ext4_ext_mark_initialized(ex); 3834 3835 /* note: ext4_ext_correct_indexes() isn't needed here because 3836 * borders are not changed 3837 */ 3838 ext4_ext_try_to_merge(handle, inode, path, ex); 3839 3840 /* Mark modified extent as dirty */ 3841 err = ext4_ext_dirty(handle, inode, path + path->p_depth); 3842 out: 3843 ext4_ext_show_leaf(inode, path); 3844 return err; 3845 } 3846 3847 /* 3848 * Handle EOFBLOCKS_FL flag, clearing it if necessary 3849 */ 3850 static int check_eofblocks_fl(handle_t *handle, struct inode *inode, 3851 ext4_lblk_t lblk, 3852 struct ext4_ext_path *path, 3853 unsigned int len) 3854 { 3855 int i, depth; 3856 struct ext4_extent_header *eh; 3857 struct ext4_extent *last_ex; 3858 3859 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)) 3860 return 0; 3861 3862 depth = ext_depth(inode); 3863 eh = path[depth].p_hdr; 3864 3865 /* 3866 * We're going to remove EOFBLOCKS_FL entirely in future so we 3867 * do not care for this case anymore. Simply remove the flag 3868 * if there are no extents. 3869 */ 3870 if (unlikely(!eh->eh_entries)) 3871 goto out; 3872 last_ex = EXT_LAST_EXTENT(eh); 3873 /* 3874 * We should clear the EOFBLOCKS_FL flag if we are writing the 3875 * last block in the last extent in the file. We test this by 3876 * first checking to see if the caller to 3877 * ext4_ext_get_blocks() was interested in the last block (or 3878 * a block beyond the last block) in the current extent. If 3879 * this turns out to be false, we can bail out from this 3880 * function immediately. 3881 */ 3882 if (lblk + len < le32_to_cpu(last_ex->ee_block) + 3883 ext4_ext_get_actual_len(last_ex)) 3884 return 0; 3885 /* 3886 * If the caller does appear to be planning to write at or 3887 * beyond the end of the current extent, we then test to see 3888 * if the current extent is the last extent in the file, by 3889 * checking to make sure it was reached via the rightmost node 3890 * at each level of the tree. 3891 */ 3892 for (i = depth-1; i >= 0; i--) 3893 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr)) 3894 return 0; 3895 out: 3896 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); 3897 return ext4_mark_inode_dirty(handle, inode); 3898 } 3899 3900 static int 3901 convert_initialized_extent(handle_t *handle, struct inode *inode, 3902 struct ext4_map_blocks *map, 3903 struct ext4_ext_path **ppath, 3904 unsigned int allocated) 3905 { 3906 struct ext4_ext_path *path = *ppath; 3907 struct ext4_extent *ex; 3908 ext4_lblk_t ee_block; 3909 unsigned int ee_len; 3910 int depth; 3911 int err = 0; 3912 3913 /* 3914 * Make sure that the extent is no bigger than we support with 3915 * unwritten extent 3916 */ 3917 if (map->m_len > EXT_UNWRITTEN_MAX_LEN) 3918 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2; 3919 3920 depth = ext_depth(inode); 3921 ex = path[depth].p_ext; 3922 ee_block = le32_to_cpu(ex->ee_block); 3923 ee_len = ext4_ext_get_actual_len(ex); 3924 3925 ext_debug("%s: inode %lu, logical" 3926 "block %llu, max_blocks %u\n", __func__, inode->i_ino, 3927 (unsigned long long)ee_block, ee_len); 3928 3929 if (ee_block != map->m_lblk || ee_len > map->m_len) { 3930 err = ext4_split_convert_extents(handle, inode, map, ppath, 3931 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN); 3932 if (err < 0) 3933 return err; 3934 path = ext4_find_extent(inode, map->m_lblk, ppath, 0); 3935 if (IS_ERR(path)) 3936 return PTR_ERR(path); 3937 depth = ext_depth(inode); 3938 ex = path[depth].p_ext; 3939 if (!ex) { 3940 EXT4_ERROR_INODE(inode, "unexpected hole at %lu", 3941 (unsigned long) map->m_lblk); 3942 return -EFSCORRUPTED; 3943 } 3944 } 3945 3946 err = ext4_ext_get_access(handle, inode, path + depth); 3947 if (err) 3948 return err; 3949 /* first mark the extent as unwritten */ 3950 ext4_ext_mark_unwritten(ex); 3951 3952 /* note: ext4_ext_correct_indexes() isn't needed here because 3953 * borders are not changed 3954 */ 3955 ext4_ext_try_to_merge(handle, inode, path, ex); 3956 3957 /* Mark modified extent as dirty */ 3958 err = ext4_ext_dirty(handle, inode, path + path->p_depth); 3959 if (err) 3960 return err; 3961 ext4_ext_show_leaf(inode, path); 3962 3963 ext4_update_inode_fsync_trans(handle, inode, 1); 3964 err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len); 3965 if (err) 3966 return err; 3967 map->m_flags |= EXT4_MAP_UNWRITTEN; 3968 if (allocated > map->m_len) 3969 allocated = map->m_len; 3970 map->m_len = allocated; 3971 return allocated; 3972 } 3973 3974 static int 3975 ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, 3976 struct ext4_map_blocks *map, 3977 struct ext4_ext_path **ppath, int flags, 3978 unsigned int allocated, ext4_fsblk_t newblock) 3979 { 3980 struct ext4_ext_path *path = *ppath; 3981 int ret = 0; 3982 int err = 0; 3983 3984 ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical " 3985 "block %llu, max_blocks %u, flags %x, allocated %u\n", 3986 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len, 3987 flags, allocated); 3988 ext4_ext_show_leaf(inode, path); 3989 3990 /* 3991 * When writing into unwritten space, we should not fail to 3992 * allocate metadata blocks for the new extent block if needed. 3993 */ 3994 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL; 3995 3996 trace_ext4_ext_handle_unwritten_extents(inode, map, flags, 3997 allocated, newblock); 3998 3999 /* get_block() before submit the IO, split the extent */ 4000 if (flags & EXT4_GET_BLOCKS_PRE_IO) { 4001 ret = ext4_split_convert_extents(handle, inode, map, ppath, 4002 flags | EXT4_GET_BLOCKS_CONVERT); 4003 if (ret <= 0) 4004 goto out; 4005 map->m_flags |= EXT4_MAP_UNWRITTEN; 4006 goto out; 4007 } 4008 /* IO end_io complete, convert the filled extent to written */ 4009 if (flags & EXT4_GET_BLOCKS_CONVERT) { 4010 if (flags & EXT4_GET_BLOCKS_ZERO) { 4011 if (allocated > map->m_len) 4012 allocated = map->m_len; 4013 err = ext4_issue_zeroout(inode, map->m_lblk, newblock, 4014 allocated); 4015 if (err < 0) 4016 goto out2; 4017 } 4018 ret = ext4_convert_unwritten_extents_endio(handle, inode, map, 4019 ppath); 4020 if (ret >= 0) { 4021 ext4_update_inode_fsync_trans(handle, inode, 1); 4022 err = check_eofblocks_fl(handle, inode, map->m_lblk, 4023 path, map->m_len); 4024 } else 4025 err = ret; 4026 map->m_flags |= EXT4_MAP_MAPPED; 4027 map->m_pblk = newblock; 4028 if (allocated > map->m_len) 4029 allocated = map->m_len; 4030 map->m_len = allocated; 4031 goto out2; 4032 } 4033 /* buffered IO case */ 4034 /* 4035 * repeat fallocate creation request 4036 * we already have an unwritten extent 4037 */ 4038 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) { 4039 map->m_flags |= EXT4_MAP_UNWRITTEN; 4040 goto map_out; 4041 } 4042 4043 /* buffered READ or buffered write_begin() lookup */ 4044 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { 4045 /* 4046 * We have blocks reserved already. We 4047 * return allocated blocks so that delalloc 4048 * won't do block reservation for us. But 4049 * the buffer head will be unmapped so that 4050 * a read from the block returns 0s. 4051 */ 4052 map->m_flags |= EXT4_MAP_UNWRITTEN; 4053 goto out1; 4054 } 4055 4056 /* buffered write, writepage time, convert*/ 4057 ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags); 4058 if (ret >= 0) 4059 ext4_update_inode_fsync_trans(handle, inode, 1); 4060 out: 4061 if (ret <= 0) { 4062 err = ret; 4063 goto out2; 4064 } else 4065 allocated = ret; 4066 map->m_flags |= EXT4_MAP_NEW; 4067 if (allocated > map->m_len) 4068 allocated = map->m_len; 4069 map->m_len = allocated; 4070 4071 map_out: 4072 map->m_flags |= EXT4_MAP_MAPPED; 4073 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) { 4074 err = check_eofblocks_fl(handle, inode, map->m_lblk, path, 4075 map->m_len); 4076 if (err < 0) 4077 goto out2; 4078 } 4079 out1: 4080 if (allocated > map->m_len) 4081 allocated = map->m_len; 4082 ext4_ext_show_leaf(inode, path); 4083 map->m_pblk = newblock; 4084 map->m_len = allocated; 4085 out2: 4086 return err ? err : allocated; 4087 } 4088 4089 /* 4090 * get_implied_cluster_alloc - check to see if the requested 4091 * allocation (in the map structure) overlaps with a cluster already 4092 * allocated in an extent. 4093 * @sb The filesystem superblock structure 4094 * @map The requested lblk->pblk mapping 4095 * @ex The extent structure which might contain an implied 4096 * cluster allocation 4097 * 4098 * This function is called by ext4_ext_map_blocks() after we failed to 4099 * find blocks that were already in the inode's extent tree. Hence, 4100 * we know that the beginning of the requested region cannot overlap 4101 * the extent from the inode's extent tree. There are three cases we 4102 * want to catch. The first is this case: 4103 * 4104 * |--- cluster # N--| 4105 * |--- extent ---| |---- requested region ---| 4106 * |==========| 4107 * 4108 * The second case that we need to test for is this one: 4109 * 4110 * |--------- cluster # N ----------------| 4111 * |--- requested region --| |------- extent ----| 4112 * |=======================| 4113 * 4114 * The third case is when the requested region lies between two extents 4115 * within the same cluster: 4116 * |------------- cluster # N-------------| 4117 * |----- ex -----| |---- ex_right ----| 4118 * |------ requested region ------| 4119 * |================| 4120 * 4121 * In each of the above cases, we need to set the map->m_pblk and 4122 * map->m_len so it corresponds to the return the extent labelled as 4123 * "|====|" from cluster #N, since it is already in use for data in 4124 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to 4125 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated 4126 * as a new "allocated" block region. Otherwise, we will return 0 and 4127 * ext4_ext_map_blocks() will then allocate one or more new clusters 4128 * by calling ext4_mb_new_blocks(). 4129 */ 4130 static int get_implied_cluster_alloc(struct super_block *sb, 4131 struct ext4_map_blocks *map, 4132 struct ext4_extent *ex, 4133 struct ext4_ext_path *path) 4134 { 4135 struct ext4_sb_info *sbi = EXT4_SB(sb); 4136 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk); 4137 ext4_lblk_t ex_cluster_start, ex_cluster_end; 4138 ext4_lblk_t rr_cluster_start; 4139 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); 4140 ext4_fsblk_t ee_start = ext4_ext_pblock(ex); 4141 unsigned short ee_len = ext4_ext_get_actual_len(ex); 4142 4143 /* The extent passed in that we are trying to match */ 4144 ex_cluster_start = EXT4_B2C(sbi, ee_block); 4145 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1); 4146 4147 /* The requested region passed into ext4_map_blocks() */ 4148 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk); 4149 4150 if ((rr_cluster_start == ex_cluster_end) || 4151 (rr_cluster_start == ex_cluster_start)) { 4152 if (rr_cluster_start == ex_cluster_end) 4153 ee_start += ee_len - 1; 4154 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset; 4155 map->m_len = min(map->m_len, 4156 (unsigned) sbi->s_cluster_ratio - c_offset); 4157 /* 4158 * Check for and handle this case: 4159 * 4160 * |--------- cluster # N-------------| 4161 * |------- extent ----| 4162 * |--- requested region ---| 4163 * |===========| 4164 */ 4165 4166 if (map->m_lblk < ee_block) 4167 map->m_len = min(map->m_len, ee_block - map->m_lblk); 4168 4169 /* 4170 * Check for the case where there is already another allocated 4171 * block to the right of 'ex' but before the end of the cluster. 4172 * 4173 * |------------- cluster # N-------------| 4174 * |----- ex -----| |---- ex_right ----| 4175 * |------ requested region ------| 4176 * |================| 4177 */ 4178 if (map->m_lblk > ee_block) { 4179 ext4_lblk_t next = ext4_ext_next_allocated_block(path); 4180 map->m_len = min(map->m_len, next - map->m_lblk); 4181 } 4182 4183 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1); 4184 return 1; 4185 } 4186 4187 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0); 4188 return 0; 4189 } 4190 4191 4192 /* 4193 * Block allocation/map/preallocation routine for extents based files 4194 * 4195 * 4196 * Need to be called with 4197 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block 4198 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) 4199 * 4200 * return > 0, number of of blocks already mapped/allocated 4201 * if create == 0 and these are pre-allocated blocks 4202 * buffer head is unmapped 4203 * otherwise blocks are mapped 4204 * 4205 * return = 0, if plain look up failed (blocks have not been allocated) 4206 * buffer head is unmapped 4207 * 4208 * return < 0, error case. 4209 */ 4210 int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, 4211 struct ext4_map_blocks *map, int flags) 4212 { 4213 struct ext4_ext_path *path = NULL; 4214 struct ext4_extent newex, *ex, *ex2; 4215 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 4216 ext4_fsblk_t newblock = 0; 4217 int free_on_err = 0, err = 0, depth, ret; 4218 unsigned int allocated = 0, offset = 0; 4219 unsigned int allocated_clusters = 0; 4220 struct ext4_allocation_request ar; 4221 ext4_lblk_t cluster_offset; 4222 bool map_from_cluster = false; 4223 4224 ext_debug("blocks %u/%u requested for inode %lu\n", 4225 map->m_lblk, map->m_len, inode->i_ino); 4226 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); 4227 4228 /* find extent for this block */ 4229 path = ext4_find_extent(inode, map->m_lblk, NULL, 0); 4230 if (IS_ERR(path)) { 4231 err = PTR_ERR(path); 4232 path = NULL; 4233 goto out2; 4234 } 4235 4236 depth = ext_depth(inode); 4237 4238 /* 4239 * consistent leaf must not be empty; 4240 * this situation is possible, though, _during_ tree modification; 4241 * this is why assert can't be put in ext4_find_extent() 4242 */ 4243 if (unlikely(path[depth].p_ext == NULL && depth != 0)) { 4244 EXT4_ERROR_INODE(inode, "bad extent address " 4245 "lblock: %lu, depth: %d pblock %lld", 4246 (unsigned long) map->m_lblk, depth, 4247 path[depth].p_block); 4248 err = -EFSCORRUPTED; 4249 goto out2; 4250 } 4251 4252 ex = path[depth].p_ext; 4253 if (ex) { 4254 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); 4255 ext4_fsblk_t ee_start = ext4_ext_pblock(ex); 4256 unsigned short ee_len; 4257 4258 4259 /* 4260 * unwritten extents are treated as holes, except that 4261 * we split out initialized portions during a write. 4262 */ 4263 ee_len = ext4_ext_get_actual_len(ex); 4264 4265 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len); 4266 4267 /* if found extent covers block, simply return it */ 4268 if (in_range(map->m_lblk, ee_block, ee_len)) { 4269 newblock = map->m_lblk - ee_block + ee_start; 4270 /* number of remaining blocks in the extent */ 4271 allocated = ee_len - (map->m_lblk - ee_block); 4272 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk, 4273 ee_block, ee_len, newblock); 4274 4275 /* 4276 * If the extent is initialized check whether the 4277 * caller wants to convert it to unwritten. 4278 */ 4279 if ((!ext4_ext_is_unwritten(ex)) && 4280 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) { 4281 allocated = convert_initialized_extent( 4282 handle, inode, map, &path, 4283 allocated); 4284 goto out2; 4285 } else if (!ext4_ext_is_unwritten(ex)) 4286 goto out; 4287 4288 ret = ext4_ext_handle_unwritten_extents( 4289 handle, inode, map, &path, flags, 4290 allocated, newblock); 4291 if (ret < 0) 4292 err = ret; 4293 else 4294 allocated = ret; 4295 goto out2; 4296 } 4297 } 4298 4299 /* 4300 * requested block isn't allocated yet; 4301 * we couldn't try to create block if create flag is zero 4302 */ 4303 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { 4304 ext4_lblk_t hole_start, hole_len; 4305 4306 hole_start = map->m_lblk; 4307 hole_len = ext4_ext_determine_hole(inode, path, &hole_start); 4308 /* 4309 * put just found gap into cache to speed up 4310 * subsequent requests 4311 */ 4312 ext4_ext_put_gap_in_cache(inode, hole_start, hole_len); 4313 4314 /* Update hole_len to reflect hole size after map->m_lblk */ 4315 if (hole_start != map->m_lblk) 4316 hole_len -= map->m_lblk - hole_start; 4317 map->m_pblk = 0; 4318 map->m_len = min_t(unsigned int, map->m_len, hole_len); 4319 4320 goto out2; 4321 } 4322 4323 /* 4324 * Okay, we need to do block allocation. 4325 */ 4326 newex.ee_block = cpu_to_le32(map->m_lblk); 4327 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk); 4328 4329 /* 4330 * If we are doing bigalloc, check to see if the extent returned 4331 * by ext4_find_extent() implies a cluster we can use. 4332 */ 4333 if (cluster_offset && ex && 4334 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) { 4335 ar.len = allocated = map->m_len; 4336 newblock = map->m_pblk; 4337 map_from_cluster = true; 4338 goto got_allocated_blocks; 4339 } 4340 4341 /* find neighbour allocated blocks */ 4342 ar.lleft = map->m_lblk; 4343 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); 4344 if (err) 4345 goto out2; 4346 ar.lright = map->m_lblk; 4347 ex2 = NULL; 4348 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2); 4349 if (err) 4350 goto out2; 4351 4352 /* Check if the extent after searching to the right implies a 4353 * cluster we can use. */ 4354 if ((sbi->s_cluster_ratio > 1) && ex2 && 4355 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) { 4356 ar.len = allocated = map->m_len; 4357 newblock = map->m_pblk; 4358 map_from_cluster = true; 4359 goto got_allocated_blocks; 4360 } 4361 4362 /* 4363 * See if request is beyond maximum number of blocks we can have in 4364 * a single extent. For an initialized extent this limit is 4365 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is 4366 * EXT_UNWRITTEN_MAX_LEN. 4367 */ 4368 if (map->m_len > EXT_INIT_MAX_LEN && 4369 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT)) 4370 map->m_len = EXT_INIT_MAX_LEN; 4371 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN && 4372 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT)) 4373 map->m_len = EXT_UNWRITTEN_MAX_LEN; 4374 4375 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */ 4376 newex.ee_len = cpu_to_le16(map->m_len); 4377 err = ext4_ext_check_overlap(sbi, inode, &newex, path); 4378 if (err) 4379 allocated = ext4_ext_get_actual_len(&newex); 4380 else 4381 allocated = map->m_len; 4382 4383 /* allocate new block */ 4384 ar.inode = inode; 4385 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk); 4386 ar.logical = map->m_lblk; 4387 /* 4388 * We calculate the offset from the beginning of the cluster 4389 * for the logical block number, since when we allocate a 4390 * physical cluster, the physical block should start at the 4391 * same offset from the beginning of the cluster. This is 4392 * needed so that future calls to get_implied_cluster_alloc() 4393 * work correctly. 4394 */ 4395 offset = EXT4_LBLK_COFF(sbi, map->m_lblk); 4396 ar.len = EXT4_NUM_B2C(sbi, offset+allocated); 4397 ar.goal -= offset; 4398 ar.logical -= offset; 4399 if (S_ISREG(inode->i_mode)) 4400 ar.flags = EXT4_MB_HINT_DATA; 4401 else 4402 /* disable in-core preallocation for non-regular files */ 4403 ar.flags = 0; 4404 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE) 4405 ar.flags |= EXT4_MB_HINT_NOPREALLOC; 4406 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) 4407 ar.flags |= EXT4_MB_DELALLOC_RESERVED; 4408 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) 4409 ar.flags |= EXT4_MB_USE_RESERVED; 4410 newblock = ext4_mb_new_blocks(handle, &ar, &err); 4411 if (!newblock) 4412 goto out2; 4413 ext_debug("allocate new block: goal %llu, found %llu/%u\n", 4414 ar.goal, newblock, allocated); 4415 free_on_err = 1; 4416 allocated_clusters = ar.len; 4417 ar.len = EXT4_C2B(sbi, ar.len) - offset; 4418 if (ar.len > allocated) 4419 ar.len = allocated; 4420 4421 got_allocated_blocks: 4422 /* try to insert new extent into found leaf and return */ 4423 ext4_ext_store_pblock(&newex, newblock + offset); 4424 newex.ee_len = cpu_to_le16(ar.len); 4425 /* Mark unwritten */ 4426 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){ 4427 ext4_ext_mark_unwritten(&newex); 4428 map->m_flags |= EXT4_MAP_UNWRITTEN; 4429 } 4430 4431 err = 0; 4432 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) 4433 err = check_eofblocks_fl(handle, inode, map->m_lblk, 4434 path, ar.len); 4435 if (!err) 4436 err = ext4_ext_insert_extent(handle, inode, &path, 4437 &newex, flags); 4438 4439 if (err && free_on_err) { 4440 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ? 4441 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0; 4442 /* free data blocks we just allocated */ 4443 /* not a good idea to call discard here directly, 4444 * but otherwise we'd need to call it every free() */ 4445 ext4_discard_preallocations(inode); 4446 ext4_free_blocks(handle, inode, NULL, newblock, 4447 EXT4_C2B(sbi, allocated_clusters), fb_flags); 4448 goto out2; 4449 } 4450 4451 /* previous routine could use block we allocated */ 4452 newblock = ext4_ext_pblock(&newex); 4453 allocated = ext4_ext_get_actual_len(&newex); 4454 if (allocated > map->m_len) 4455 allocated = map->m_len; 4456 map->m_flags |= EXT4_MAP_NEW; 4457 4458 /* 4459 * Reduce the reserved cluster count to reflect successful deferred 4460 * allocation of delayed allocated clusters or direct allocation of 4461 * clusters discovered to be delayed allocated. Once allocated, a 4462 * cluster is not included in the reserved count. 4463 */ 4464 if (test_opt(inode->i_sb, DELALLOC) && !map_from_cluster) { 4465 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { 4466 /* 4467 * When allocating delayed allocated clusters, simply 4468 * reduce the reserved cluster count and claim quota 4469 */ 4470 ext4_da_update_reserve_space(inode, allocated_clusters, 4471 1); 4472 } else { 4473 ext4_lblk_t lblk, len; 4474 unsigned int n; 4475 4476 /* 4477 * When allocating non-delayed allocated clusters 4478 * (from fallocate, filemap, DIO, or clusters 4479 * allocated when delalloc has been disabled by 4480 * ext4_nonda_switch), reduce the reserved cluster 4481 * count by the number of allocated clusters that 4482 * have previously been delayed allocated. Quota 4483 * has been claimed by ext4_mb_new_blocks() above, 4484 * so release the quota reservations made for any 4485 * previously delayed allocated clusters. 4486 */ 4487 lblk = EXT4_LBLK_CMASK(sbi, map->m_lblk); 4488 len = allocated_clusters << sbi->s_cluster_bits; 4489 n = ext4_es_delayed_clu(inode, lblk, len); 4490 if (n > 0) 4491 ext4_da_update_reserve_space(inode, (int) n, 0); 4492 } 4493 } 4494 4495 /* 4496 * Cache the extent and update transaction to commit on fdatasync only 4497 * when it is _not_ an unwritten extent. 4498 */ 4499 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0) 4500 ext4_update_inode_fsync_trans(handle, inode, 1); 4501 else 4502 ext4_update_inode_fsync_trans(handle, inode, 0); 4503 out: 4504 if (allocated > map->m_len) 4505 allocated = map->m_len; 4506 ext4_ext_show_leaf(inode, path); 4507 map->m_flags |= EXT4_MAP_MAPPED; 4508 map->m_pblk = newblock; 4509 map->m_len = allocated; 4510 out2: 4511 ext4_ext_drop_refs(path); 4512 kfree(path); 4513 4514 trace_ext4_ext_map_blocks_exit(inode, flags, map, 4515 err ? err : allocated); 4516 return err ? err : allocated; 4517 } 4518 4519 int ext4_ext_truncate(handle_t *handle, struct inode *inode) 4520 { 4521 struct super_block *sb = inode->i_sb; 4522 ext4_lblk_t last_block; 4523 int err = 0; 4524 4525 /* 4526 * TODO: optimization is possible here. 4527 * Probably we need not scan at all, 4528 * because page truncation is enough. 4529 */ 4530 4531 /* we have to know where to truncate from in crash case */ 4532 EXT4_I(inode)->i_disksize = inode->i_size; 4533 err = ext4_mark_inode_dirty(handle, inode); 4534 if (err) 4535 return err; 4536 4537 last_block = (inode->i_size + sb->s_blocksize - 1) 4538 >> EXT4_BLOCK_SIZE_BITS(sb); 4539 retry: 4540 err = ext4_es_remove_extent(inode, last_block, 4541 EXT_MAX_BLOCKS - last_block); 4542 if (err == -ENOMEM) { 4543 cond_resched(); 4544 congestion_wait(BLK_RW_ASYNC, HZ/50); 4545 goto retry; 4546 } 4547 if (err) 4548 return err; 4549 return ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1); 4550 } 4551 4552 static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset, 4553 ext4_lblk_t len, loff_t new_size, 4554 int flags) 4555 { 4556 struct inode *inode = file_inode(file); 4557 handle_t *handle; 4558 int ret = 0; 4559 int ret2 = 0; 4560 int retries = 0; 4561 int depth = 0; 4562 struct ext4_map_blocks map; 4563 unsigned int credits; 4564 loff_t epos; 4565 4566 BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)); 4567 map.m_lblk = offset; 4568 map.m_len = len; 4569 /* 4570 * Don't normalize the request if it can fit in one extent so 4571 * that it doesn't get unnecessarily split into multiple 4572 * extents. 4573 */ 4574 if (len <= EXT_UNWRITTEN_MAX_LEN) 4575 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE; 4576 4577 /* 4578 * credits to insert 1 extent into extent tree 4579 */ 4580 credits = ext4_chunk_trans_blocks(inode, len); 4581 depth = ext_depth(inode); 4582 4583 retry: 4584 while (ret >= 0 && len) { 4585 /* 4586 * Recalculate credits when extent tree depth changes. 4587 */ 4588 if (depth != ext_depth(inode)) { 4589 credits = ext4_chunk_trans_blocks(inode, len); 4590 depth = ext_depth(inode); 4591 } 4592 4593 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, 4594 credits); 4595 if (IS_ERR(handle)) { 4596 ret = PTR_ERR(handle); 4597 break; 4598 } 4599 ret = ext4_map_blocks(handle, inode, &map, flags); 4600 if (ret <= 0) { 4601 ext4_debug("inode #%lu: block %u: len %u: " 4602 "ext4_ext_map_blocks returned %d", 4603 inode->i_ino, map.m_lblk, 4604 map.m_len, ret); 4605 ext4_mark_inode_dirty(handle, inode); 4606 ret2 = ext4_journal_stop(handle); 4607 break; 4608 } 4609 map.m_lblk += ret; 4610 map.m_len = len = len - ret; 4611 epos = (loff_t)map.m_lblk << inode->i_blkbits; 4612 inode->i_ctime = current_time(inode); 4613 if (new_size) { 4614 if (epos > new_size) 4615 epos = new_size; 4616 if (ext4_update_inode_size(inode, epos) & 0x1) 4617 inode->i_mtime = inode->i_ctime; 4618 } else { 4619 if (epos > inode->i_size) 4620 ext4_set_inode_flag(inode, 4621 EXT4_INODE_EOFBLOCKS); 4622 } 4623 ext4_mark_inode_dirty(handle, inode); 4624 ext4_update_inode_fsync_trans(handle, inode, 1); 4625 ret2 = ext4_journal_stop(handle); 4626 if (ret2) 4627 break; 4628 } 4629 if (ret == -ENOSPC && 4630 ext4_should_retry_alloc(inode->i_sb, &retries)) { 4631 ret = 0; 4632 goto retry; 4633 } 4634 4635 return ret > 0 ? ret2 : ret; 4636 } 4637 4638 static long ext4_zero_range(struct file *file, loff_t offset, 4639 loff_t len, int mode) 4640 { 4641 struct inode *inode = file_inode(file); 4642 handle_t *handle = NULL; 4643 unsigned int max_blocks; 4644 loff_t new_size = 0; 4645 int ret = 0; 4646 int flags; 4647 int credits; 4648 int partial_begin, partial_end; 4649 loff_t start, end; 4650 ext4_lblk_t lblk; 4651 unsigned int blkbits = inode->i_blkbits; 4652 4653 trace_ext4_zero_range(inode, offset, len, mode); 4654 4655 if (!S_ISREG(inode->i_mode)) 4656 return -EINVAL; 4657 4658 /* Call ext4_force_commit to flush all data in case of data=journal. */ 4659 if (ext4_should_journal_data(inode)) { 4660 ret = ext4_force_commit(inode->i_sb); 4661 if (ret) 4662 return ret; 4663 } 4664 4665 /* 4666 * Round up offset. This is not fallocate, we neet to zero out 4667 * blocks, so convert interior block aligned part of the range to 4668 * unwritten and possibly manually zero out unaligned parts of the 4669 * range. 4670 */ 4671 start = round_up(offset, 1 << blkbits); 4672 end = round_down((offset + len), 1 << blkbits); 4673 4674 if (start < offset || end > offset + len) 4675 return -EINVAL; 4676 partial_begin = offset & ((1 << blkbits) - 1); 4677 partial_end = (offset + len) & ((1 << blkbits) - 1); 4678 4679 lblk = start >> blkbits; 4680 max_blocks = (end >> blkbits); 4681 if (max_blocks < lblk) 4682 max_blocks = 0; 4683 else 4684 max_blocks -= lblk; 4685 4686 inode_lock(inode); 4687 4688 /* 4689 * Indirect files do not support unwritten extnets 4690 */ 4691 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { 4692 ret = -EOPNOTSUPP; 4693 goto out_mutex; 4694 } 4695 4696 if (!(mode & FALLOC_FL_KEEP_SIZE) && 4697 (offset + len > i_size_read(inode) || 4698 offset + len > EXT4_I(inode)->i_disksize)) { 4699 new_size = offset + len; 4700 ret = inode_newsize_ok(inode, new_size); 4701 if (ret) 4702 goto out_mutex; 4703 } 4704 4705 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT; 4706 if (mode & FALLOC_FL_KEEP_SIZE) 4707 flags |= EXT4_GET_BLOCKS_KEEP_SIZE; 4708 4709 /* Wait all existing dio workers, newcomers will block on i_mutex */ 4710 inode_dio_wait(inode); 4711 4712 /* Preallocate the range including the unaligned edges */ 4713 if (partial_begin || partial_end) { 4714 ret = ext4_alloc_file_blocks(file, 4715 round_down(offset, 1 << blkbits) >> blkbits, 4716 (round_up((offset + len), 1 << blkbits) - 4717 round_down(offset, 1 << blkbits)) >> blkbits, 4718 new_size, flags); 4719 if (ret) 4720 goto out_mutex; 4721 4722 } 4723 4724 /* Zero range excluding the unaligned edges */ 4725 if (max_blocks > 0) { 4726 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN | 4727 EXT4_EX_NOCACHE); 4728 4729 /* 4730 * Prevent page faults from reinstantiating pages we have 4731 * released from page cache. 4732 */ 4733 down_write(&EXT4_I(inode)->i_mmap_sem); 4734 4735 ret = ext4_break_layouts(inode); 4736 if (ret) { 4737 up_write(&EXT4_I(inode)->i_mmap_sem); 4738 goto out_mutex; 4739 } 4740 4741 ret = ext4_update_disksize_before_punch(inode, offset, len); 4742 if (ret) { 4743 up_write(&EXT4_I(inode)->i_mmap_sem); 4744 goto out_mutex; 4745 } 4746 /* Now release the pages and zero block aligned part of pages */ 4747 truncate_pagecache_range(inode, start, end - 1); 4748 inode->i_mtime = inode->i_ctime = current_time(inode); 4749 4750 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, 4751 flags); 4752 up_write(&EXT4_I(inode)->i_mmap_sem); 4753 if (ret) 4754 goto out_mutex; 4755 } 4756 if (!partial_begin && !partial_end) 4757 goto out_mutex; 4758 4759 /* 4760 * In worst case we have to writeout two nonadjacent unwritten 4761 * blocks and update the inode 4762 */ 4763 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1; 4764 if (ext4_should_journal_data(inode)) 4765 credits += 2; 4766 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits); 4767 if (IS_ERR(handle)) { 4768 ret = PTR_ERR(handle); 4769 ext4_std_error(inode->i_sb, ret); 4770 goto out_mutex; 4771 } 4772 4773 inode->i_mtime = inode->i_ctime = current_time(inode); 4774 if (new_size) { 4775 ext4_update_inode_size(inode, new_size); 4776 } else { 4777 /* 4778 * Mark that we allocate beyond EOF so the subsequent truncate 4779 * can proceed even if the new size is the same as i_size. 4780 */ 4781 if ((offset + len) > i_size_read(inode)) 4782 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS); 4783 } 4784 ext4_mark_inode_dirty(handle, inode); 4785 4786 /* Zero out partial block at the edges of the range */ 4787 ret = ext4_zero_partial_blocks(handle, inode, offset, len); 4788 if (ret >= 0) 4789 ext4_update_inode_fsync_trans(handle, inode, 1); 4790 4791 if (file->f_flags & O_SYNC) 4792 ext4_handle_sync(handle); 4793 4794 ext4_journal_stop(handle); 4795 out_mutex: 4796 inode_unlock(inode); 4797 return ret; 4798 } 4799 4800 /* 4801 * preallocate space for a file. This implements ext4's fallocate file 4802 * operation, which gets called from sys_fallocate system call. 4803 * For block-mapped files, posix_fallocate should fall back to the method 4804 * of writing zeroes to the required new blocks (the same behavior which is 4805 * expected for file systems which do not support fallocate() system call). 4806 */ 4807 long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) 4808 { 4809 struct inode *inode = file_inode(file); 4810 loff_t new_size = 0; 4811 unsigned int max_blocks; 4812 int ret = 0; 4813 int flags; 4814 ext4_lblk_t lblk; 4815 unsigned int blkbits = inode->i_blkbits; 4816 4817 /* 4818 * Encrypted inodes can't handle collapse range or insert 4819 * range since we would need to re-encrypt blocks with a 4820 * different IV or XTS tweak (which are based on the logical 4821 * block number). 4822 * 4823 * XXX It's not clear why zero range isn't working, but we'll 4824 * leave it disabled for encrypted inodes for now. This is a 4825 * bug we should fix.... 4826 */ 4827 if (IS_ENCRYPTED(inode) && 4828 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE | 4829 FALLOC_FL_ZERO_RANGE))) 4830 return -EOPNOTSUPP; 4831 4832 /* Return error if mode is not supported */ 4833 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | 4834 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | 4835 FALLOC_FL_INSERT_RANGE)) 4836 return -EOPNOTSUPP; 4837 4838 if (mode & FALLOC_FL_PUNCH_HOLE) 4839 return ext4_punch_hole(inode, offset, len); 4840 4841 ret = ext4_convert_inline_data(inode); 4842 if (ret) 4843 return ret; 4844 4845 if (mode & FALLOC_FL_COLLAPSE_RANGE) 4846 return ext4_collapse_range(inode, offset, len); 4847 4848 if (mode & FALLOC_FL_INSERT_RANGE) 4849 return ext4_insert_range(inode, offset, len); 4850 4851 if (mode & FALLOC_FL_ZERO_RANGE) 4852 return ext4_zero_range(file, offset, len, mode); 4853 4854 trace_ext4_fallocate_enter(inode, offset, len, mode); 4855 lblk = offset >> blkbits; 4856 4857 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits); 4858 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT; 4859 if (mode & FALLOC_FL_KEEP_SIZE) 4860 flags |= EXT4_GET_BLOCKS_KEEP_SIZE; 4861 4862 inode_lock(inode); 4863 4864 /* 4865 * We only support preallocation for extent-based files only 4866 */ 4867 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { 4868 ret = -EOPNOTSUPP; 4869 goto out; 4870 } 4871 4872 if (!(mode & FALLOC_FL_KEEP_SIZE) && 4873 (offset + len > i_size_read(inode) || 4874 offset + len > EXT4_I(inode)->i_disksize)) { 4875 new_size = offset + len; 4876 ret = inode_newsize_ok(inode, new_size); 4877 if (ret) 4878 goto out; 4879 } 4880 4881 /* Wait all existing dio workers, newcomers will block on i_mutex */ 4882 inode_dio_wait(inode); 4883 4884 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags); 4885 if (ret) 4886 goto out; 4887 4888 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) { 4889 ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal, 4890 EXT4_I(inode)->i_sync_tid); 4891 } 4892 out: 4893 inode_unlock(inode); 4894 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); 4895 return ret; 4896 } 4897 4898 /* 4899 * This function convert a range of blocks to written extents 4900 * The caller of this function will pass the start offset and the size. 4901 * all unwritten extents within this range will be converted to 4902 * written extents. 4903 * 4904 * This function is called from the direct IO end io call back 4905 * function, to convert the fallocated extents after IO is completed. 4906 * Returns 0 on success. 4907 */ 4908 int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode, 4909 loff_t offset, ssize_t len) 4910 { 4911 unsigned int max_blocks; 4912 int ret = 0; 4913 int ret2 = 0; 4914 struct ext4_map_blocks map; 4915 unsigned int credits, blkbits = inode->i_blkbits; 4916 4917 map.m_lblk = offset >> blkbits; 4918 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits); 4919 4920 /* 4921 * This is somewhat ugly but the idea is clear: When transaction is 4922 * reserved, everything goes into it. Otherwise we rather start several 4923 * smaller transactions for conversion of each extent separately. 4924 */ 4925 if (handle) { 4926 handle = ext4_journal_start_reserved(handle, 4927 EXT4_HT_EXT_CONVERT); 4928 if (IS_ERR(handle)) 4929 return PTR_ERR(handle); 4930 credits = 0; 4931 } else { 4932 /* 4933 * credits to insert 1 extent into extent tree 4934 */ 4935 credits = ext4_chunk_trans_blocks(inode, max_blocks); 4936 } 4937 while (ret >= 0 && ret < max_blocks) { 4938 map.m_lblk += ret; 4939 map.m_len = (max_blocks -= ret); 4940 if (credits) { 4941 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, 4942 credits); 4943 if (IS_ERR(handle)) { 4944 ret = PTR_ERR(handle); 4945 break; 4946 } 4947 } 4948 ret = ext4_map_blocks(handle, inode, &map, 4949 EXT4_GET_BLOCKS_IO_CONVERT_EXT); 4950 if (ret <= 0) 4951 ext4_warning(inode->i_sb, 4952 "inode #%lu: block %u: len %u: " 4953 "ext4_ext_map_blocks returned %d", 4954 inode->i_ino, map.m_lblk, 4955 map.m_len, ret); 4956 ext4_mark_inode_dirty(handle, inode); 4957 if (credits) 4958 ret2 = ext4_journal_stop(handle); 4959 if (ret <= 0 || ret2) 4960 break; 4961 } 4962 if (!credits) 4963 ret2 = ext4_journal_stop(handle); 4964 return ret > 0 ? ret2 : ret; 4965 } 4966 4967 /* 4968 * If newes is not existing extent (newes->ec_pblk equals zero) find 4969 * delayed extent at start of newes and update newes accordingly and 4970 * return start of the next delayed extent. 4971 * 4972 * If newes is existing extent (newes->ec_pblk is not equal zero) 4973 * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed 4974 * extent found. Leave newes unmodified. 4975 */ 4976 static int ext4_find_delayed_extent(struct inode *inode, 4977 struct extent_status *newes) 4978 { 4979 struct extent_status es; 4980 ext4_lblk_t block, next_del; 4981 4982 if (newes->es_pblk == 0) { 4983 ext4_es_find_extent_range(inode, &ext4_es_is_delayed, 4984 newes->es_lblk, 4985 newes->es_lblk + newes->es_len - 1, 4986 &es); 4987 4988 /* 4989 * No extent in extent-tree contains block @newes->es_pblk, 4990 * then the block may stay in 1)a hole or 2)delayed-extent. 4991 */ 4992 if (es.es_len == 0) 4993 /* A hole found. */ 4994 return 0; 4995 4996 if (es.es_lblk > newes->es_lblk) { 4997 /* A hole found. */ 4998 newes->es_len = min(es.es_lblk - newes->es_lblk, 4999 newes->es_len); 5000 return 0; 5001 } 5002 5003 newes->es_len = es.es_lblk + es.es_len - newes->es_lblk; 5004 } 5005 5006 block = newes->es_lblk + newes->es_len; 5007 ext4_es_find_extent_range(inode, &ext4_es_is_delayed, block, 5008 EXT_MAX_BLOCKS, &es); 5009 if (es.es_len == 0) 5010 next_del = EXT_MAX_BLOCKS; 5011 else 5012 next_del = es.es_lblk; 5013 5014 return next_del; 5015 } 5016 /* fiemap flags we can handle specified here */ 5017 #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR) 5018 5019 static int ext4_xattr_fiemap(struct inode *inode, 5020 struct fiemap_extent_info *fieinfo) 5021 { 5022 __u64 physical = 0; 5023 __u64 length; 5024 __u32 flags = FIEMAP_EXTENT_LAST; 5025 int blockbits = inode->i_sb->s_blocksize_bits; 5026 int error = 0; 5027 5028 /* in-inode? */ 5029 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 5030 struct ext4_iloc iloc; 5031 int offset; /* offset of xattr in inode */ 5032 5033 error = ext4_get_inode_loc(inode, &iloc); 5034 if (error) 5035 return error; 5036 physical = (__u64)iloc.bh->b_blocknr << blockbits; 5037 offset = EXT4_GOOD_OLD_INODE_SIZE + 5038 EXT4_I(inode)->i_extra_isize; 5039 physical += offset; 5040 length = EXT4_SB(inode->i_sb)->s_inode_size - offset; 5041 flags |= FIEMAP_EXTENT_DATA_INLINE; 5042 brelse(iloc.bh); 5043 } else { /* external block */ 5044 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits; 5045 length = inode->i_sb->s_blocksize; 5046 } 5047 5048 if (physical) 5049 error = fiemap_fill_next_extent(fieinfo, 0, physical, 5050 length, flags); 5051 return (error < 0 ? error : 0); 5052 } 5053 5054 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 5055 __u64 start, __u64 len) 5056 { 5057 ext4_lblk_t start_blk; 5058 int error = 0; 5059 5060 if (ext4_has_inline_data(inode)) { 5061 int has_inline = 1; 5062 5063 error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline, 5064 start, len); 5065 5066 if (has_inline) 5067 return error; 5068 } 5069 5070 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) { 5071 error = ext4_ext_precache(inode); 5072 if (error) 5073 return error; 5074 } 5075 5076 /* fallback to generic here if not in extents fmt */ 5077 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 5078 return generic_block_fiemap(inode, fieinfo, start, len, 5079 ext4_get_block); 5080 5081 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS)) 5082 return -EBADR; 5083 5084 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { 5085 error = ext4_xattr_fiemap(inode, fieinfo); 5086 } else { 5087 ext4_lblk_t len_blks; 5088 __u64 last_blk; 5089 5090 start_blk = start >> inode->i_sb->s_blocksize_bits; 5091 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits; 5092 if (last_blk >= EXT_MAX_BLOCKS) 5093 last_blk = EXT_MAX_BLOCKS-1; 5094 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1; 5095 5096 /* 5097 * Walk the extent tree gathering extent information 5098 * and pushing extents back to the user. 5099 */ 5100 error = ext4_fill_fiemap_extents(inode, start_blk, 5101 len_blks, fieinfo); 5102 } 5103 return error; 5104 } 5105 5106 /* 5107 * ext4_access_path: 5108 * Function to access the path buffer for marking it dirty. 5109 * It also checks if there are sufficient credits left in the journal handle 5110 * to update path. 5111 */ 5112 static int 5113 ext4_access_path(handle_t *handle, struct inode *inode, 5114 struct ext4_ext_path *path) 5115 { 5116 int credits, err; 5117 5118 if (!ext4_handle_valid(handle)) 5119 return 0; 5120 5121 /* 5122 * Check if need to extend journal credits 5123 * 3 for leaf, sb, and inode plus 2 (bmap and group 5124 * descriptor) for each block group; assume two block 5125 * groups 5126 */ 5127 if (handle->h_buffer_credits < 7) { 5128 credits = ext4_writepage_trans_blocks(inode); 5129 err = ext4_ext_truncate_extend_restart(handle, inode, credits); 5130 /* EAGAIN is success */ 5131 if (err && err != -EAGAIN) 5132 return err; 5133 } 5134 5135 err = ext4_ext_get_access(handle, inode, path); 5136 return err; 5137 } 5138 5139 /* 5140 * ext4_ext_shift_path_extents: 5141 * Shift the extents of a path structure lying between path[depth].p_ext 5142 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells 5143 * if it is right shift or left shift operation. 5144 */ 5145 static int 5146 ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift, 5147 struct inode *inode, handle_t *handle, 5148 enum SHIFT_DIRECTION SHIFT) 5149 { 5150 int depth, err = 0; 5151 struct ext4_extent *ex_start, *ex_last; 5152 bool update = 0; 5153 depth = path->p_depth; 5154 5155 while (depth >= 0) { 5156 if (depth == path->p_depth) { 5157 ex_start = path[depth].p_ext; 5158 if (!ex_start) 5159 return -EFSCORRUPTED; 5160 5161 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr); 5162 5163 err = ext4_access_path(handle, inode, path + depth); 5164 if (err) 5165 goto out; 5166 5167 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) 5168 update = 1; 5169 5170 while (ex_start <= ex_last) { 5171 if (SHIFT == SHIFT_LEFT) { 5172 le32_add_cpu(&ex_start->ee_block, 5173 -shift); 5174 /* Try to merge to the left. */ 5175 if ((ex_start > 5176 EXT_FIRST_EXTENT(path[depth].p_hdr)) 5177 && 5178 ext4_ext_try_to_merge_right(inode, 5179 path, ex_start - 1)) 5180 ex_last--; 5181 else 5182 ex_start++; 5183 } else { 5184 le32_add_cpu(&ex_last->ee_block, shift); 5185 ext4_ext_try_to_merge_right(inode, path, 5186 ex_last); 5187 ex_last--; 5188 } 5189 } 5190 err = ext4_ext_dirty(handle, inode, path + depth); 5191 if (err) 5192 goto out; 5193 5194 if (--depth < 0 || !update) 5195 break; 5196 } 5197 5198 /* Update index too */ 5199 err = ext4_access_path(handle, inode, path + depth); 5200 if (err) 5201 goto out; 5202 5203 if (SHIFT == SHIFT_LEFT) 5204 le32_add_cpu(&path[depth].p_idx->ei_block, -shift); 5205 else 5206 le32_add_cpu(&path[depth].p_idx->ei_block, shift); 5207 err = ext4_ext_dirty(handle, inode, path + depth); 5208 if (err) 5209 goto out; 5210 5211 /* we are done if current index is not a starting index */ 5212 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr)) 5213 break; 5214 5215 depth--; 5216 } 5217 5218 out: 5219 return err; 5220 } 5221 5222 /* 5223 * ext4_ext_shift_extents: 5224 * All the extents which lies in the range from @start to the last allocated 5225 * block for the @inode are shifted either towards left or right (depending 5226 * upon @SHIFT) by @shift blocks. 5227 * On success, 0 is returned, error otherwise. 5228 */ 5229 static int 5230 ext4_ext_shift_extents(struct inode *inode, handle_t *handle, 5231 ext4_lblk_t start, ext4_lblk_t shift, 5232 enum SHIFT_DIRECTION SHIFT) 5233 { 5234 struct ext4_ext_path *path; 5235 int ret = 0, depth; 5236 struct ext4_extent *extent; 5237 ext4_lblk_t stop, *iterator, ex_start, ex_end; 5238 5239 /* Let path point to the last extent */ 5240 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 5241 EXT4_EX_NOCACHE); 5242 if (IS_ERR(path)) 5243 return PTR_ERR(path); 5244 5245 depth = path->p_depth; 5246 extent = path[depth].p_ext; 5247 if (!extent) 5248 goto out; 5249 5250 stop = le32_to_cpu(extent->ee_block); 5251 5252 /* 5253 * For left shifts, make sure the hole on the left is big enough to 5254 * accommodate the shift. For right shifts, make sure the last extent 5255 * won't be shifted beyond EXT_MAX_BLOCKS. 5256 */ 5257 if (SHIFT == SHIFT_LEFT) { 5258 path = ext4_find_extent(inode, start - 1, &path, 5259 EXT4_EX_NOCACHE); 5260 if (IS_ERR(path)) 5261 return PTR_ERR(path); 5262 depth = path->p_depth; 5263 extent = path[depth].p_ext; 5264 if (extent) { 5265 ex_start = le32_to_cpu(extent->ee_block); 5266 ex_end = le32_to_cpu(extent->ee_block) + 5267 ext4_ext_get_actual_len(extent); 5268 } else { 5269 ex_start = 0; 5270 ex_end = 0; 5271 } 5272 5273 if ((start == ex_start && shift > ex_start) || 5274 (shift > start - ex_end)) { 5275 ret = -EINVAL; 5276 goto out; 5277 } 5278 } else { 5279 if (shift > EXT_MAX_BLOCKS - 5280 (stop + ext4_ext_get_actual_len(extent))) { 5281 ret = -EINVAL; 5282 goto out; 5283 } 5284 } 5285 5286 /* 5287 * In case of left shift, iterator points to start and it is increased 5288 * till we reach stop. In case of right shift, iterator points to stop 5289 * and it is decreased till we reach start. 5290 */ 5291 if (SHIFT == SHIFT_LEFT) 5292 iterator = &start; 5293 else 5294 iterator = &stop; 5295 5296 /* 5297 * Its safe to start updating extents. Start and stop are unsigned, so 5298 * in case of right shift if extent with 0 block is reached, iterator 5299 * becomes NULL to indicate the end of the loop. 5300 */ 5301 while (iterator && start <= stop) { 5302 path = ext4_find_extent(inode, *iterator, &path, 5303 EXT4_EX_NOCACHE); 5304 if (IS_ERR(path)) 5305 return PTR_ERR(path); 5306 depth = path->p_depth; 5307 extent = path[depth].p_ext; 5308 if (!extent) { 5309 EXT4_ERROR_INODE(inode, "unexpected hole at %lu", 5310 (unsigned long) *iterator); 5311 return -EFSCORRUPTED; 5312 } 5313 if (SHIFT == SHIFT_LEFT && *iterator > 5314 le32_to_cpu(extent->ee_block)) { 5315 /* Hole, move to the next extent */ 5316 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) { 5317 path[depth].p_ext++; 5318 } else { 5319 *iterator = ext4_ext_next_allocated_block(path); 5320 continue; 5321 } 5322 } 5323 5324 if (SHIFT == SHIFT_LEFT) { 5325 extent = EXT_LAST_EXTENT(path[depth].p_hdr); 5326 *iterator = le32_to_cpu(extent->ee_block) + 5327 ext4_ext_get_actual_len(extent); 5328 } else { 5329 extent = EXT_FIRST_EXTENT(path[depth].p_hdr); 5330 if (le32_to_cpu(extent->ee_block) > 0) 5331 *iterator = le32_to_cpu(extent->ee_block) - 1; 5332 else 5333 /* Beginning is reached, end of the loop */ 5334 iterator = NULL; 5335 /* Update path extent in case we need to stop */ 5336 while (le32_to_cpu(extent->ee_block) < start) 5337 extent++; 5338 path[depth].p_ext = extent; 5339 } 5340 ret = ext4_ext_shift_path_extents(path, shift, inode, 5341 handle, SHIFT); 5342 if (ret) 5343 break; 5344 } 5345 out: 5346 ext4_ext_drop_refs(path); 5347 kfree(path); 5348 return ret; 5349 } 5350 5351 /* 5352 * ext4_collapse_range: 5353 * This implements the fallocate's collapse range functionality for ext4 5354 * Returns: 0 and non-zero on error. 5355 */ 5356 int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) 5357 { 5358 struct super_block *sb = inode->i_sb; 5359 ext4_lblk_t punch_start, punch_stop; 5360 handle_t *handle; 5361 unsigned int credits; 5362 loff_t new_size, ioffset; 5363 int ret; 5364 5365 /* 5366 * We need to test this early because xfstests assumes that a 5367 * collapse range of (0, 1) will return EOPNOTSUPP if the file 5368 * system does not support collapse range. 5369 */ 5370 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) 5371 return -EOPNOTSUPP; 5372 5373 /* Collapse range works only on fs block size aligned offsets. */ 5374 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) || 5375 len & (EXT4_CLUSTER_SIZE(sb) - 1)) 5376 return -EINVAL; 5377 5378 if (!S_ISREG(inode->i_mode)) 5379 return -EINVAL; 5380 5381 trace_ext4_collapse_range(inode, offset, len); 5382 5383 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb); 5384 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb); 5385 5386 /* Call ext4_force_commit to flush all data in case of data=journal. */ 5387 if (ext4_should_journal_data(inode)) { 5388 ret = ext4_force_commit(inode->i_sb); 5389 if (ret) 5390 return ret; 5391 } 5392 5393 inode_lock(inode); 5394 /* 5395 * There is no need to overlap collapse range with EOF, in which case 5396 * it is effectively a truncate operation 5397 */ 5398 if (offset + len >= i_size_read(inode)) { 5399 ret = -EINVAL; 5400 goto out_mutex; 5401 } 5402 5403 /* Currently just for extent based files */ 5404 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { 5405 ret = -EOPNOTSUPP; 5406 goto out_mutex; 5407 } 5408 5409 /* Wait for existing dio to complete */ 5410 inode_dio_wait(inode); 5411 5412 /* 5413 * Prevent page faults from reinstantiating pages we have released from 5414 * page cache. 5415 */ 5416 down_write(&EXT4_I(inode)->i_mmap_sem); 5417 5418 ret = ext4_break_layouts(inode); 5419 if (ret) 5420 goto out_mmap; 5421 5422 /* 5423 * Need to round down offset to be aligned with page size boundary 5424 * for page size > block size. 5425 */ 5426 ioffset = round_down(offset, PAGE_SIZE); 5427 /* 5428 * Write tail of the last page before removed range since it will get 5429 * removed from the page cache below. 5430 */ 5431 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, offset); 5432 if (ret) 5433 goto out_mmap; 5434 /* 5435 * Write data that will be shifted to preserve them when discarding 5436 * page cache below. We are also protected from pages becoming dirty 5437 * by i_mmap_sem. 5438 */ 5439 ret = filemap_write_and_wait_range(inode->i_mapping, offset + len, 5440 LLONG_MAX); 5441 if (ret) 5442 goto out_mmap; 5443 truncate_pagecache(inode, ioffset); 5444 5445 credits = ext4_writepage_trans_blocks(inode); 5446 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); 5447 if (IS_ERR(handle)) { 5448 ret = PTR_ERR(handle); 5449 goto out_mmap; 5450 } 5451 5452 down_write(&EXT4_I(inode)->i_data_sem); 5453 ext4_discard_preallocations(inode); 5454 5455 ret = ext4_es_remove_extent(inode, punch_start, 5456 EXT_MAX_BLOCKS - punch_start); 5457 if (ret) { 5458 up_write(&EXT4_I(inode)->i_data_sem); 5459 goto out_stop; 5460 } 5461 5462 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1); 5463 if (ret) { 5464 up_write(&EXT4_I(inode)->i_data_sem); 5465 goto out_stop; 5466 } 5467 ext4_discard_preallocations(inode); 5468 5469 ret = ext4_ext_shift_extents(inode, handle, punch_stop, 5470 punch_stop - punch_start, SHIFT_LEFT); 5471 if (ret) { 5472 up_write(&EXT4_I(inode)->i_data_sem); 5473 goto out_stop; 5474 } 5475 5476 new_size = i_size_read(inode) - len; 5477 i_size_write(inode, new_size); 5478 EXT4_I(inode)->i_disksize = new_size; 5479 5480 up_write(&EXT4_I(inode)->i_data_sem); 5481 if (IS_SYNC(inode)) 5482 ext4_handle_sync(handle); 5483 inode->i_mtime = inode->i_ctime = current_time(inode); 5484 ext4_mark_inode_dirty(handle, inode); 5485 ext4_update_inode_fsync_trans(handle, inode, 1); 5486 5487 out_stop: 5488 ext4_journal_stop(handle); 5489 out_mmap: 5490 up_write(&EXT4_I(inode)->i_mmap_sem); 5491 out_mutex: 5492 inode_unlock(inode); 5493 return ret; 5494 } 5495 5496 /* 5497 * ext4_insert_range: 5498 * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate. 5499 * The data blocks starting from @offset to the EOF are shifted by @len 5500 * towards right to create a hole in the @inode. Inode size is increased 5501 * by len bytes. 5502 * Returns 0 on success, error otherwise. 5503 */ 5504 int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len) 5505 { 5506 struct super_block *sb = inode->i_sb; 5507 handle_t *handle; 5508 struct ext4_ext_path *path; 5509 struct ext4_extent *extent; 5510 ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0; 5511 unsigned int credits, ee_len; 5512 int ret = 0, depth, split_flag = 0; 5513 loff_t ioffset; 5514 5515 /* 5516 * We need to test this early because xfstests assumes that an 5517 * insert range of (0, 1) will return EOPNOTSUPP if the file 5518 * system does not support insert range. 5519 */ 5520 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) 5521 return -EOPNOTSUPP; 5522 5523 /* Insert range works only on fs block size aligned offsets. */ 5524 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) || 5525 len & (EXT4_CLUSTER_SIZE(sb) - 1)) 5526 return -EINVAL; 5527 5528 if (!S_ISREG(inode->i_mode)) 5529 return -EOPNOTSUPP; 5530 5531 trace_ext4_insert_range(inode, offset, len); 5532 5533 offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb); 5534 len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb); 5535 5536 /* Call ext4_force_commit to flush all data in case of data=journal */ 5537 if (ext4_should_journal_data(inode)) { 5538 ret = ext4_force_commit(inode->i_sb); 5539 if (ret) 5540 return ret; 5541 } 5542 5543 inode_lock(inode); 5544 /* Currently just for extent based files */ 5545 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { 5546 ret = -EOPNOTSUPP; 5547 goto out_mutex; 5548 } 5549 5550 /* Check for wrap through zero */ 5551 if (inode->i_size + len > inode->i_sb->s_maxbytes) { 5552 ret = -EFBIG; 5553 goto out_mutex; 5554 } 5555 5556 /* Offset should be less than i_size */ 5557 if (offset >= i_size_read(inode)) { 5558 ret = -EINVAL; 5559 goto out_mutex; 5560 } 5561 5562 /* Wait for existing dio to complete */ 5563 inode_dio_wait(inode); 5564 5565 /* 5566 * Prevent page faults from reinstantiating pages we have released from 5567 * page cache. 5568 */ 5569 down_write(&EXT4_I(inode)->i_mmap_sem); 5570 5571 ret = ext4_break_layouts(inode); 5572 if (ret) 5573 goto out_mmap; 5574 5575 /* 5576 * Need to round down to align start offset to page size boundary 5577 * for page size > block size. 5578 */ 5579 ioffset = round_down(offset, PAGE_SIZE); 5580 /* Write out all dirty pages */ 5581 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, 5582 LLONG_MAX); 5583 if (ret) 5584 goto out_mmap; 5585 truncate_pagecache(inode, ioffset); 5586 5587 credits = ext4_writepage_trans_blocks(inode); 5588 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); 5589 if (IS_ERR(handle)) { 5590 ret = PTR_ERR(handle); 5591 goto out_mmap; 5592 } 5593 5594 /* Expand file to avoid data loss if there is error while shifting */ 5595 inode->i_size += len; 5596 EXT4_I(inode)->i_disksize += len; 5597 inode->i_mtime = inode->i_ctime = current_time(inode); 5598 ret = ext4_mark_inode_dirty(handle, inode); 5599 if (ret) 5600 goto out_stop; 5601 5602 down_write(&EXT4_I(inode)->i_data_sem); 5603 ext4_discard_preallocations(inode); 5604 5605 path = ext4_find_extent(inode, offset_lblk, NULL, 0); 5606 if (IS_ERR(path)) { 5607 up_write(&EXT4_I(inode)->i_data_sem); 5608 goto out_stop; 5609 } 5610 5611 depth = ext_depth(inode); 5612 extent = path[depth].p_ext; 5613 if (extent) { 5614 ee_start_lblk = le32_to_cpu(extent->ee_block); 5615 ee_len = ext4_ext_get_actual_len(extent); 5616 5617 /* 5618 * If offset_lblk is not the starting block of extent, split 5619 * the extent @offset_lblk 5620 */ 5621 if ((offset_lblk > ee_start_lblk) && 5622 (offset_lblk < (ee_start_lblk + ee_len))) { 5623 if (ext4_ext_is_unwritten(extent)) 5624 split_flag = EXT4_EXT_MARK_UNWRIT1 | 5625 EXT4_EXT_MARK_UNWRIT2; 5626 ret = ext4_split_extent_at(handle, inode, &path, 5627 offset_lblk, split_flag, 5628 EXT4_EX_NOCACHE | 5629 EXT4_GET_BLOCKS_PRE_IO | 5630 EXT4_GET_BLOCKS_METADATA_NOFAIL); 5631 } 5632 5633 ext4_ext_drop_refs(path); 5634 kfree(path); 5635 if (ret < 0) { 5636 up_write(&EXT4_I(inode)->i_data_sem); 5637 goto out_stop; 5638 } 5639 } else { 5640 ext4_ext_drop_refs(path); 5641 kfree(path); 5642 } 5643 5644 ret = ext4_es_remove_extent(inode, offset_lblk, 5645 EXT_MAX_BLOCKS - offset_lblk); 5646 if (ret) { 5647 up_write(&EXT4_I(inode)->i_data_sem); 5648 goto out_stop; 5649 } 5650 5651 /* 5652 * if offset_lblk lies in a hole which is at start of file, use 5653 * ee_start_lblk to shift extents 5654 */ 5655 ret = ext4_ext_shift_extents(inode, handle, 5656 ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk, 5657 len_lblk, SHIFT_RIGHT); 5658 5659 up_write(&EXT4_I(inode)->i_data_sem); 5660 if (IS_SYNC(inode)) 5661 ext4_handle_sync(handle); 5662 if (ret >= 0) 5663 ext4_update_inode_fsync_trans(handle, inode, 1); 5664 5665 out_stop: 5666 ext4_journal_stop(handle); 5667 out_mmap: 5668 up_write(&EXT4_I(inode)->i_mmap_sem); 5669 out_mutex: 5670 inode_unlock(inode); 5671 return ret; 5672 } 5673 5674 /** 5675 * ext4_swap_extents - Swap extents between two inodes 5676 * 5677 * @inode1: First inode 5678 * @inode2: Second inode 5679 * @lblk1: Start block for first inode 5680 * @lblk2: Start block for second inode 5681 * @count: Number of blocks to swap 5682 * @unwritten: Mark second inode's extents as unwritten after swap 5683 * @erp: Pointer to save error value 5684 * 5685 * This helper routine does exactly what is promise "swap extents". All other 5686 * stuff such as page-cache locking consistency, bh mapping consistency or 5687 * extent's data copying must be performed by caller. 5688 * Locking: 5689 * i_mutex is held for both inodes 5690 * i_data_sem is locked for write for both inodes 5691 * Assumptions: 5692 * All pages from requested range are locked for both inodes 5693 */ 5694 int 5695 ext4_swap_extents(handle_t *handle, struct inode *inode1, 5696 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2, 5697 ext4_lblk_t count, int unwritten, int *erp) 5698 { 5699 struct ext4_ext_path *path1 = NULL; 5700 struct ext4_ext_path *path2 = NULL; 5701 int replaced_count = 0; 5702 5703 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem)); 5704 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem)); 5705 BUG_ON(!inode_is_locked(inode1)); 5706 BUG_ON(!inode_is_locked(inode2)); 5707 5708 *erp = ext4_es_remove_extent(inode1, lblk1, count); 5709 if (unlikely(*erp)) 5710 return 0; 5711 *erp = ext4_es_remove_extent(inode2, lblk2, count); 5712 if (unlikely(*erp)) 5713 return 0; 5714 5715 while (count) { 5716 struct ext4_extent *ex1, *ex2, tmp_ex; 5717 ext4_lblk_t e1_blk, e2_blk; 5718 int e1_len, e2_len, len; 5719 int split = 0; 5720 5721 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE); 5722 if (IS_ERR(path1)) { 5723 *erp = PTR_ERR(path1); 5724 path1 = NULL; 5725 finish: 5726 count = 0; 5727 goto repeat; 5728 } 5729 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE); 5730 if (IS_ERR(path2)) { 5731 *erp = PTR_ERR(path2); 5732 path2 = NULL; 5733 goto finish; 5734 } 5735 ex1 = path1[path1->p_depth].p_ext; 5736 ex2 = path2[path2->p_depth].p_ext; 5737 /* Do we have somthing to swap ? */ 5738 if (unlikely(!ex2 || !ex1)) 5739 goto finish; 5740 5741 e1_blk = le32_to_cpu(ex1->ee_block); 5742 e2_blk = le32_to_cpu(ex2->ee_block); 5743 e1_len = ext4_ext_get_actual_len(ex1); 5744 e2_len = ext4_ext_get_actual_len(ex2); 5745 5746 /* Hole handling */ 5747 if (!in_range(lblk1, e1_blk, e1_len) || 5748 !in_range(lblk2, e2_blk, e2_len)) { 5749 ext4_lblk_t next1, next2; 5750 5751 /* if hole after extent, then go to next extent */ 5752 next1 = ext4_ext_next_allocated_block(path1); 5753 next2 = ext4_ext_next_allocated_block(path2); 5754 /* If hole before extent, then shift to that extent */ 5755 if (e1_blk > lblk1) 5756 next1 = e1_blk; 5757 if (e2_blk > lblk2) 5758 next2 = e2_blk; 5759 /* Do we have something to swap */ 5760 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS) 5761 goto finish; 5762 /* Move to the rightest boundary */ 5763 len = next1 - lblk1; 5764 if (len < next2 - lblk2) 5765 len = next2 - lblk2; 5766 if (len > count) 5767 len = count; 5768 lblk1 += len; 5769 lblk2 += len; 5770 count -= len; 5771 goto repeat; 5772 } 5773 5774 /* Prepare left boundary */ 5775 if (e1_blk < lblk1) { 5776 split = 1; 5777 *erp = ext4_force_split_extent_at(handle, inode1, 5778 &path1, lblk1, 0); 5779 if (unlikely(*erp)) 5780 goto finish; 5781 } 5782 if (e2_blk < lblk2) { 5783 split = 1; 5784 *erp = ext4_force_split_extent_at(handle, inode2, 5785 &path2, lblk2, 0); 5786 if (unlikely(*erp)) 5787 goto finish; 5788 } 5789 /* ext4_split_extent_at() may result in leaf extent split, 5790 * path must to be revalidated. */ 5791 if (split) 5792 goto repeat; 5793 5794 /* Prepare right boundary */ 5795 len = count; 5796 if (len > e1_blk + e1_len - lblk1) 5797 len = e1_blk + e1_len - lblk1; 5798 if (len > e2_blk + e2_len - lblk2) 5799 len = e2_blk + e2_len - lblk2; 5800 5801 if (len != e1_len) { 5802 split = 1; 5803 *erp = ext4_force_split_extent_at(handle, inode1, 5804 &path1, lblk1 + len, 0); 5805 if (unlikely(*erp)) 5806 goto finish; 5807 } 5808 if (len != e2_len) { 5809 split = 1; 5810 *erp = ext4_force_split_extent_at(handle, inode2, 5811 &path2, lblk2 + len, 0); 5812 if (*erp) 5813 goto finish; 5814 } 5815 /* ext4_split_extent_at() may result in leaf extent split, 5816 * path must to be revalidated. */ 5817 if (split) 5818 goto repeat; 5819 5820 BUG_ON(e2_len != e1_len); 5821 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth); 5822 if (unlikely(*erp)) 5823 goto finish; 5824 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth); 5825 if (unlikely(*erp)) 5826 goto finish; 5827 5828 /* Both extents are fully inside boundaries. Swap it now */ 5829 tmp_ex = *ex1; 5830 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2)); 5831 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex)); 5832 ex1->ee_len = cpu_to_le16(e2_len); 5833 ex2->ee_len = cpu_to_le16(e1_len); 5834 if (unwritten) 5835 ext4_ext_mark_unwritten(ex2); 5836 if (ext4_ext_is_unwritten(&tmp_ex)) 5837 ext4_ext_mark_unwritten(ex1); 5838 5839 ext4_ext_try_to_merge(handle, inode2, path2, ex2); 5840 ext4_ext_try_to_merge(handle, inode1, path1, ex1); 5841 *erp = ext4_ext_dirty(handle, inode2, path2 + 5842 path2->p_depth); 5843 if (unlikely(*erp)) 5844 goto finish; 5845 *erp = ext4_ext_dirty(handle, inode1, path1 + 5846 path1->p_depth); 5847 /* 5848 * Looks scarry ah..? second inode already points to new blocks, 5849 * and it was successfully dirtied. But luckily error may happen 5850 * only due to journal error, so full transaction will be 5851 * aborted anyway. 5852 */ 5853 if (unlikely(*erp)) 5854 goto finish; 5855 lblk1 += len; 5856 lblk2 += len; 5857 replaced_count += len; 5858 count -= len; 5859 5860 repeat: 5861 ext4_ext_drop_refs(path1); 5862 kfree(path1); 5863 ext4_ext_drop_refs(path2); 5864 kfree(path2); 5865 path1 = path2 = NULL; 5866 } 5867 return replaced_count; 5868 } 5869 5870 /* 5871 * ext4_clu_mapped - determine whether any block in a logical cluster has 5872 * been mapped to a physical cluster 5873 * 5874 * @inode - file containing the logical cluster 5875 * @lclu - logical cluster of interest 5876 * 5877 * Returns 1 if any block in the logical cluster is mapped, signifying 5878 * that a physical cluster has been allocated for it. Otherwise, 5879 * returns 0. Can also return negative error codes. Derived from 5880 * ext4_ext_map_blocks(). 5881 */ 5882 int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu) 5883 { 5884 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 5885 struct ext4_ext_path *path; 5886 int depth, mapped = 0, err = 0; 5887 struct ext4_extent *extent; 5888 ext4_lblk_t first_lblk, first_lclu, last_lclu; 5889 5890 /* search for the extent closest to the first block in the cluster */ 5891 path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0); 5892 if (IS_ERR(path)) { 5893 err = PTR_ERR(path); 5894 path = NULL; 5895 goto out; 5896 } 5897 5898 depth = ext_depth(inode); 5899 5900 /* 5901 * A consistent leaf must not be empty. This situation is possible, 5902 * though, _during_ tree modification, and it's why an assert can't 5903 * be put in ext4_find_extent(). 5904 */ 5905 if (unlikely(path[depth].p_ext == NULL && depth != 0)) { 5906 EXT4_ERROR_INODE(inode, 5907 "bad extent address - lblock: %lu, depth: %d, pblock: %lld", 5908 (unsigned long) EXT4_C2B(sbi, lclu), 5909 depth, path[depth].p_block); 5910 err = -EFSCORRUPTED; 5911 goto out; 5912 } 5913 5914 extent = path[depth].p_ext; 5915 5916 /* can't be mapped if the extent tree is empty */ 5917 if (extent == NULL) 5918 goto out; 5919 5920 first_lblk = le32_to_cpu(extent->ee_block); 5921 first_lclu = EXT4_B2C(sbi, first_lblk); 5922 5923 /* 5924 * Three possible outcomes at this point - found extent spanning 5925 * the target cluster, to the left of the target cluster, or to the 5926 * right of the target cluster. The first two cases are handled here. 5927 * The last case indicates the target cluster is not mapped. 5928 */ 5929 if (lclu >= first_lclu) { 5930 last_lclu = EXT4_B2C(sbi, first_lblk + 5931 ext4_ext_get_actual_len(extent) - 1); 5932 if (lclu <= last_lclu) { 5933 mapped = 1; 5934 } else { 5935 first_lblk = ext4_ext_next_allocated_block(path); 5936 first_lclu = EXT4_B2C(sbi, first_lblk); 5937 if (lclu == first_lclu) 5938 mapped = 1; 5939 } 5940 } 5941 5942 out: 5943 ext4_ext_drop_refs(path); 5944 kfree(path); 5945 5946 return err ? err : mapped; 5947 } 5948