1 /* 2 * Copyright (C) 2007 Oracle. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 19 #include <linux/fs.h> 20 #include <linux/pagemap.h> 21 #include <linux/highmem.h> 22 #include <linux/time.h> 23 #include <linux/init.h> 24 #include <linux/string.h> 25 #include <linux/backing-dev.h> 26 #include <linux/mpage.h> 27 #include <linux/falloc.h> 28 #include <linux/swap.h> 29 #include <linux/writeback.h> 30 #include <linux/compat.h> 31 #include <linux/slab.h> 32 #include <linux/btrfs.h> 33 #include <linux/uio.h> 34 #include "ctree.h" 35 #include "disk-io.h" 36 #include "transaction.h" 37 #include "btrfs_inode.h" 38 #include "print-tree.h" 39 #include "tree-log.h" 40 #include "locking.h" 41 #include "volumes.h" 42 #include "qgroup.h" 43 #include "compression.h" 44 45 static struct kmem_cache *btrfs_inode_defrag_cachep; 46 /* 47 * when auto defrag is enabled we 48 * queue up these defrag structs to remember which 49 * inodes need defragging passes 50 */ 51 struct inode_defrag { 52 struct rb_node rb_node; 53 /* objectid */ 54 u64 ino; 55 /* 56 * transid where the defrag was added, we search for 57 * extents newer than this 58 */ 59 u64 transid; 60 61 /* root objectid */ 62 u64 root; 63 64 /* last offset we were able to defrag */ 65 u64 last_offset; 66 67 /* if we've wrapped around back to zero once already */ 68 int cycled; 69 }; 70 71 static int __compare_inode_defrag(struct inode_defrag *defrag1, 72 struct inode_defrag *defrag2) 73 { 74 if (defrag1->root > defrag2->root) 75 return 1; 76 else if (defrag1->root < defrag2->root) 77 return -1; 78 else if (defrag1->ino > defrag2->ino) 79 return 1; 80 else if (defrag1->ino < defrag2->ino) 81 return -1; 82 else 83 return 0; 84 } 85 86 /* pop a record for an inode into the defrag tree. The lock 87 * must be held already 88 * 89 * If you're inserting a record for an older transid than an 90 * existing record, the transid already in the tree is lowered 91 * 92 * If an existing record is found the defrag item you 93 * pass in is freed 94 */ 95 static int __btrfs_add_inode_defrag(struct inode *inode, 96 struct inode_defrag *defrag) 97 { 98 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 99 struct inode_defrag *entry; 100 struct rb_node **p; 101 struct rb_node *parent = NULL; 102 int ret; 103 104 p = &fs_info->defrag_inodes.rb_node; 105 while (*p) { 106 parent = *p; 107 entry = rb_entry(parent, struct inode_defrag, rb_node); 108 109 ret = __compare_inode_defrag(defrag, entry); 110 if (ret < 0) 111 p = &parent->rb_left; 112 else if (ret > 0) 113 p = &parent->rb_right; 114 else { 115 /* if we're reinserting an entry for 116 * an old defrag run, make sure to 117 * lower the transid of our existing record 118 */ 119 if (defrag->transid < entry->transid) 120 entry->transid = defrag->transid; 121 if (defrag->last_offset > entry->last_offset) 122 entry->last_offset = defrag->last_offset; 123 return -EEXIST; 124 } 125 } 126 set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags); 127 rb_link_node(&defrag->rb_node, parent, p); 128 rb_insert_color(&defrag->rb_node, &fs_info->defrag_inodes); 129 return 0; 130 } 131 132 static inline int __need_auto_defrag(struct btrfs_fs_info *fs_info) 133 { 134 if (!btrfs_test_opt(fs_info, AUTO_DEFRAG)) 135 return 0; 136 137 if (btrfs_fs_closing(fs_info)) 138 return 0; 139 140 return 1; 141 } 142 143 /* 144 * insert a defrag record for this inode if auto defrag is 145 * enabled 146 */ 147 int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans, 148 struct inode *inode) 149 { 150 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 151 struct btrfs_root *root = BTRFS_I(inode)->root; 152 struct inode_defrag *defrag; 153 u64 transid; 154 int ret; 155 156 if (!__need_auto_defrag(fs_info)) 157 return 0; 158 159 if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) 160 return 0; 161 162 if (trans) 163 transid = trans->transid; 164 else 165 transid = BTRFS_I(inode)->root->last_trans; 166 167 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS); 168 if (!defrag) 169 return -ENOMEM; 170 171 defrag->ino = btrfs_ino(inode); 172 defrag->transid = transid; 173 defrag->root = root->root_key.objectid; 174 175 spin_lock(&fs_info->defrag_inodes_lock); 176 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) { 177 /* 178 * If we set IN_DEFRAG flag and evict the inode from memory, 179 * and then re-read this inode, this new inode doesn't have 180 * IN_DEFRAG flag. At the case, we may find the existed defrag. 181 */ 182 ret = __btrfs_add_inode_defrag(inode, defrag); 183 if (ret) 184 kmem_cache_free(btrfs_inode_defrag_cachep, defrag); 185 } else { 186 kmem_cache_free(btrfs_inode_defrag_cachep, defrag); 187 } 188 spin_unlock(&fs_info->defrag_inodes_lock); 189 return 0; 190 } 191 192 /* 193 * Requeue the defrag object. If there is a defrag object that points to 194 * the same inode in the tree, we will merge them together (by 195 * __btrfs_add_inode_defrag()) and free the one that we want to requeue. 196 */ 197 static void btrfs_requeue_inode_defrag(struct inode *inode, 198 struct inode_defrag *defrag) 199 { 200 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 201 int ret; 202 203 if (!__need_auto_defrag(fs_info)) 204 goto out; 205 206 /* 207 * Here we don't check the IN_DEFRAG flag, because we need merge 208 * them together. 209 */ 210 spin_lock(&fs_info->defrag_inodes_lock); 211 ret = __btrfs_add_inode_defrag(inode, defrag); 212 spin_unlock(&fs_info->defrag_inodes_lock); 213 if (ret) 214 goto out; 215 return; 216 out: 217 kmem_cache_free(btrfs_inode_defrag_cachep, defrag); 218 } 219 220 /* 221 * pick the defragable inode that we want, if it doesn't exist, we will get 222 * the next one. 223 */ 224 static struct inode_defrag * 225 btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino) 226 { 227 struct inode_defrag *entry = NULL; 228 struct inode_defrag tmp; 229 struct rb_node *p; 230 struct rb_node *parent = NULL; 231 int ret; 232 233 tmp.ino = ino; 234 tmp.root = root; 235 236 spin_lock(&fs_info->defrag_inodes_lock); 237 p = fs_info->defrag_inodes.rb_node; 238 while (p) { 239 parent = p; 240 entry = rb_entry(parent, struct inode_defrag, rb_node); 241 242 ret = __compare_inode_defrag(&tmp, entry); 243 if (ret < 0) 244 p = parent->rb_left; 245 else if (ret > 0) 246 p = parent->rb_right; 247 else 248 goto out; 249 } 250 251 if (parent && __compare_inode_defrag(&tmp, entry) > 0) { 252 parent = rb_next(parent); 253 if (parent) 254 entry = rb_entry(parent, struct inode_defrag, rb_node); 255 else 256 entry = NULL; 257 } 258 out: 259 if (entry) 260 rb_erase(parent, &fs_info->defrag_inodes); 261 spin_unlock(&fs_info->defrag_inodes_lock); 262 return entry; 263 } 264 265 void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info) 266 { 267 struct inode_defrag *defrag; 268 struct rb_node *node; 269 270 spin_lock(&fs_info->defrag_inodes_lock); 271 node = rb_first(&fs_info->defrag_inodes); 272 while (node) { 273 rb_erase(node, &fs_info->defrag_inodes); 274 defrag = rb_entry(node, struct inode_defrag, rb_node); 275 kmem_cache_free(btrfs_inode_defrag_cachep, defrag); 276 277 cond_resched_lock(&fs_info->defrag_inodes_lock); 278 279 node = rb_first(&fs_info->defrag_inodes); 280 } 281 spin_unlock(&fs_info->defrag_inodes_lock); 282 } 283 284 #define BTRFS_DEFRAG_BATCH 1024 285 286 static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info, 287 struct inode_defrag *defrag) 288 { 289 struct btrfs_root *inode_root; 290 struct inode *inode; 291 struct btrfs_key key; 292 struct btrfs_ioctl_defrag_range_args range; 293 int num_defrag; 294 int index; 295 int ret; 296 297 /* get the inode */ 298 key.objectid = defrag->root; 299 key.type = BTRFS_ROOT_ITEM_KEY; 300 key.offset = (u64)-1; 301 302 index = srcu_read_lock(&fs_info->subvol_srcu); 303 304 inode_root = btrfs_read_fs_root_no_name(fs_info, &key); 305 if (IS_ERR(inode_root)) { 306 ret = PTR_ERR(inode_root); 307 goto cleanup; 308 } 309 310 key.objectid = defrag->ino; 311 key.type = BTRFS_INODE_ITEM_KEY; 312 key.offset = 0; 313 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL); 314 if (IS_ERR(inode)) { 315 ret = PTR_ERR(inode); 316 goto cleanup; 317 } 318 srcu_read_unlock(&fs_info->subvol_srcu, index); 319 320 /* do a chunk of defrag */ 321 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags); 322 memset(&range, 0, sizeof(range)); 323 range.len = (u64)-1; 324 range.start = defrag->last_offset; 325 326 sb_start_write(fs_info->sb); 327 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid, 328 BTRFS_DEFRAG_BATCH); 329 sb_end_write(fs_info->sb); 330 /* 331 * if we filled the whole defrag batch, there 332 * must be more work to do. Queue this defrag 333 * again 334 */ 335 if (num_defrag == BTRFS_DEFRAG_BATCH) { 336 defrag->last_offset = range.start; 337 btrfs_requeue_inode_defrag(inode, defrag); 338 } else if (defrag->last_offset && !defrag->cycled) { 339 /* 340 * we didn't fill our defrag batch, but 341 * we didn't start at zero. Make sure we loop 342 * around to the start of the file. 343 */ 344 defrag->last_offset = 0; 345 defrag->cycled = 1; 346 btrfs_requeue_inode_defrag(inode, defrag); 347 } else { 348 kmem_cache_free(btrfs_inode_defrag_cachep, defrag); 349 } 350 351 iput(inode); 352 return 0; 353 cleanup: 354 srcu_read_unlock(&fs_info->subvol_srcu, index); 355 kmem_cache_free(btrfs_inode_defrag_cachep, defrag); 356 return ret; 357 } 358 359 /* 360 * run through the list of inodes in the FS that need 361 * defragging 362 */ 363 int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info) 364 { 365 struct inode_defrag *defrag; 366 u64 first_ino = 0; 367 u64 root_objectid = 0; 368 369 atomic_inc(&fs_info->defrag_running); 370 while (1) { 371 /* Pause the auto defragger. */ 372 if (test_bit(BTRFS_FS_STATE_REMOUNTING, 373 &fs_info->fs_state)) 374 break; 375 376 if (!__need_auto_defrag(fs_info)) 377 break; 378 379 /* find an inode to defrag */ 380 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid, 381 first_ino); 382 if (!defrag) { 383 if (root_objectid || first_ino) { 384 root_objectid = 0; 385 first_ino = 0; 386 continue; 387 } else { 388 break; 389 } 390 } 391 392 first_ino = defrag->ino + 1; 393 root_objectid = defrag->root; 394 395 __btrfs_run_defrag_inode(fs_info, defrag); 396 } 397 atomic_dec(&fs_info->defrag_running); 398 399 /* 400 * during unmount, we use the transaction_wait queue to 401 * wait for the defragger to stop 402 */ 403 wake_up(&fs_info->transaction_wait); 404 return 0; 405 } 406 407 /* simple helper to fault in pages and copy. This should go away 408 * and be replaced with calls into generic code. 409 */ 410 static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes, 411 struct page **prepared_pages, 412 struct iov_iter *i) 413 { 414 size_t copied = 0; 415 size_t total_copied = 0; 416 int pg = 0; 417 int offset = pos & (PAGE_SIZE - 1); 418 419 while (write_bytes > 0) { 420 size_t count = min_t(size_t, 421 PAGE_SIZE - offset, write_bytes); 422 struct page *page = prepared_pages[pg]; 423 /* 424 * Copy data from userspace to the current page 425 */ 426 copied = iov_iter_copy_from_user_atomic(page, i, offset, count); 427 428 /* Flush processor's dcache for this page */ 429 flush_dcache_page(page); 430 431 /* 432 * if we get a partial write, we can end up with 433 * partially up to date pages. These add 434 * a lot of complexity, so make sure they don't 435 * happen by forcing this copy to be retried. 436 * 437 * The rest of the btrfs_file_write code will fall 438 * back to page at a time copies after we return 0. 439 */ 440 if (!PageUptodate(page) && copied < count) 441 copied = 0; 442 443 iov_iter_advance(i, copied); 444 write_bytes -= copied; 445 total_copied += copied; 446 447 /* Return to btrfs_file_write_iter to fault page */ 448 if (unlikely(copied == 0)) 449 break; 450 451 if (copied < PAGE_SIZE - offset) { 452 offset += copied; 453 } else { 454 pg++; 455 offset = 0; 456 } 457 } 458 return total_copied; 459 } 460 461 /* 462 * unlocks pages after btrfs_file_write is done with them 463 */ 464 static void btrfs_drop_pages(struct page **pages, size_t num_pages) 465 { 466 size_t i; 467 for (i = 0; i < num_pages; i++) { 468 /* page checked is some magic around finding pages that 469 * have been modified without going through btrfs_set_page_dirty 470 * clear it here. There should be no need to mark the pages 471 * accessed as prepare_pages should have marked them accessed 472 * in prepare_pages via find_or_create_page() 473 */ 474 ClearPageChecked(pages[i]); 475 unlock_page(pages[i]); 476 put_page(pages[i]); 477 } 478 } 479 480 /* 481 * after copy_from_user, pages need to be dirtied and we need to make 482 * sure holes are created between the current EOF and the start of 483 * any next extents (if required). 484 * 485 * this also makes the decision about creating an inline extent vs 486 * doing real data extents, marking pages dirty and delalloc as required. 487 */ 488 int btrfs_dirty_pages(struct inode *inode, struct page **pages, 489 size_t num_pages, loff_t pos, size_t write_bytes, 490 struct extent_state **cached) 491 { 492 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 493 int err = 0; 494 int i; 495 u64 num_bytes; 496 u64 start_pos; 497 u64 end_of_last_block; 498 u64 end_pos = pos + write_bytes; 499 loff_t isize = i_size_read(inode); 500 501 start_pos = pos & ~((u64) fs_info->sectorsize - 1); 502 num_bytes = round_up(write_bytes + pos - start_pos, 503 fs_info->sectorsize); 504 505 end_of_last_block = start_pos + num_bytes - 1; 506 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block, 507 cached, 0); 508 if (err) 509 return err; 510 511 for (i = 0; i < num_pages; i++) { 512 struct page *p = pages[i]; 513 SetPageUptodate(p); 514 ClearPageChecked(p); 515 set_page_dirty(p); 516 } 517 518 /* 519 * we've only changed i_size in ram, and we haven't updated 520 * the disk i_size. There is no need to log the inode 521 * at this time. 522 */ 523 if (end_pos > isize) 524 i_size_write(inode, end_pos); 525 return 0; 526 } 527 528 /* 529 * this drops all the extents in the cache that intersect the range 530 * [start, end]. Existing extents are split as required. 531 */ 532 void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, 533 int skip_pinned) 534 { 535 struct extent_map *em; 536 struct extent_map *split = NULL; 537 struct extent_map *split2 = NULL; 538 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 539 u64 len = end - start + 1; 540 u64 gen; 541 int ret; 542 int testend = 1; 543 unsigned long flags; 544 int compressed = 0; 545 bool modified; 546 547 WARN_ON(end < start); 548 if (end == (u64)-1) { 549 len = (u64)-1; 550 testend = 0; 551 } 552 while (1) { 553 int no_splits = 0; 554 555 modified = false; 556 if (!split) 557 split = alloc_extent_map(); 558 if (!split2) 559 split2 = alloc_extent_map(); 560 if (!split || !split2) 561 no_splits = 1; 562 563 write_lock(&em_tree->lock); 564 em = lookup_extent_mapping(em_tree, start, len); 565 if (!em) { 566 write_unlock(&em_tree->lock); 567 break; 568 } 569 flags = em->flags; 570 gen = em->generation; 571 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) { 572 if (testend && em->start + em->len >= start + len) { 573 free_extent_map(em); 574 write_unlock(&em_tree->lock); 575 break; 576 } 577 start = em->start + em->len; 578 if (testend) 579 len = start + len - (em->start + em->len); 580 free_extent_map(em); 581 write_unlock(&em_tree->lock); 582 continue; 583 } 584 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 585 clear_bit(EXTENT_FLAG_PINNED, &em->flags); 586 clear_bit(EXTENT_FLAG_LOGGING, &flags); 587 modified = !list_empty(&em->list); 588 if (no_splits) 589 goto next; 590 591 if (em->start < start) { 592 split->start = em->start; 593 split->len = start - em->start; 594 595 if (em->block_start < EXTENT_MAP_LAST_BYTE) { 596 split->orig_start = em->orig_start; 597 split->block_start = em->block_start; 598 599 if (compressed) 600 split->block_len = em->block_len; 601 else 602 split->block_len = split->len; 603 split->orig_block_len = max(split->block_len, 604 em->orig_block_len); 605 split->ram_bytes = em->ram_bytes; 606 } else { 607 split->orig_start = split->start; 608 split->block_len = 0; 609 split->block_start = em->block_start; 610 split->orig_block_len = 0; 611 split->ram_bytes = split->len; 612 } 613 614 split->generation = gen; 615 split->bdev = em->bdev; 616 split->flags = flags; 617 split->compress_type = em->compress_type; 618 replace_extent_mapping(em_tree, em, split, modified); 619 free_extent_map(split); 620 split = split2; 621 split2 = NULL; 622 } 623 if (testend && em->start + em->len > start + len) { 624 u64 diff = start + len - em->start; 625 626 split->start = start + len; 627 split->len = em->start + em->len - (start + len); 628 split->bdev = em->bdev; 629 split->flags = flags; 630 split->compress_type = em->compress_type; 631 split->generation = gen; 632 633 if (em->block_start < EXTENT_MAP_LAST_BYTE) { 634 split->orig_block_len = max(em->block_len, 635 em->orig_block_len); 636 637 split->ram_bytes = em->ram_bytes; 638 if (compressed) { 639 split->block_len = em->block_len; 640 split->block_start = em->block_start; 641 split->orig_start = em->orig_start; 642 } else { 643 split->block_len = split->len; 644 split->block_start = em->block_start 645 + diff; 646 split->orig_start = em->orig_start; 647 } 648 } else { 649 split->ram_bytes = split->len; 650 split->orig_start = split->start; 651 split->block_len = 0; 652 split->block_start = em->block_start; 653 split->orig_block_len = 0; 654 } 655 656 if (extent_map_in_tree(em)) { 657 replace_extent_mapping(em_tree, em, split, 658 modified); 659 } else { 660 ret = add_extent_mapping(em_tree, split, 661 modified); 662 ASSERT(ret == 0); /* Logic error */ 663 } 664 free_extent_map(split); 665 split = NULL; 666 } 667 next: 668 if (extent_map_in_tree(em)) 669 remove_extent_mapping(em_tree, em); 670 write_unlock(&em_tree->lock); 671 672 /* once for us */ 673 free_extent_map(em); 674 /* once for the tree*/ 675 free_extent_map(em); 676 } 677 if (split) 678 free_extent_map(split); 679 if (split2) 680 free_extent_map(split2); 681 } 682 683 /* 684 * this is very complex, but the basic idea is to drop all extents 685 * in the range start - end. hint_block is filled in with a block number 686 * that would be a good hint to the block allocator for this file. 687 * 688 * If an extent intersects the range but is not entirely inside the range 689 * it is either truncated or split. Anything entirely inside the range 690 * is deleted from the tree. 691 */ 692 int __btrfs_drop_extents(struct btrfs_trans_handle *trans, 693 struct btrfs_root *root, struct inode *inode, 694 struct btrfs_path *path, u64 start, u64 end, 695 u64 *drop_end, int drop_cache, 696 int replace_extent, 697 u32 extent_item_size, 698 int *key_inserted) 699 { 700 struct btrfs_fs_info *fs_info = root->fs_info; 701 struct extent_buffer *leaf; 702 struct btrfs_file_extent_item *fi; 703 struct btrfs_key key; 704 struct btrfs_key new_key; 705 u64 ino = btrfs_ino(inode); 706 u64 search_start = start; 707 u64 disk_bytenr = 0; 708 u64 num_bytes = 0; 709 u64 extent_offset = 0; 710 u64 extent_end = 0; 711 u64 last_end = start; 712 int del_nr = 0; 713 int del_slot = 0; 714 int extent_type; 715 int recow; 716 int ret; 717 int modify_tree = -1; 718 int update_refs; 719 int found = 0; 720 int leafs_visited = 0; 721 722 if (drop_cache) 723 btrfs_drop_extent_cache(inode, start, end - 1, 0); 724 725 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent) 726 modify_tree = 0; 727 728 update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || 729 root == fs_info->tree_root); 730 while (1) { 731 recow = 0; 732 ret = btrfs_lookup_file_extent(trans, root, path, ino, 733 search_start, modify_tree); 734 if (ret < 0) 735 break; 736 if (ret > 0 && path->slots[0] > 0 && search_start == start) { 737 leaf = path->nodes[0]; 738 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1); 739 if (key.objectid == ino && 740 key.type == BTRFS_EXTENT_DATA_KEY) 741 path->slots[0]--; 742 } 743 ret = 0; 744 leafs_visited++; 745 next_slot: 746 leaf = path->nodes[0]; 747 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 748 BUG_ON(del_nr > 0); 749 ret = btrfs_next_leaf(root, path); 750 if (ret < 0) 751 break; 752 if (ret > 0) { 753 ret = 0; 754 break; 755 } 756 leafs_visited++; 757 leaf = path->nodes[0]; 758 recow = 1; 759 } 760 761 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 762 763 if (key.objectid > ino) 764 break; 765 if (WARN_ON_ONCE(key.objectid < ino) || 766 key.type < BTRFS_EXTENT_DATA_KEY) { 767 ASSERT(del_nr == 0); 768 path->slots[0]++; 769 goto next_slot; 770 } 771 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end) 772 break; 773 774 fi = btrfs_item_ptr(leaf, path->slots[0], 775 struct btrfs_file_extent_item); 776 extent_type = btrfs_file_extent_type(leaf, fi); 777 778 if (extent_type == BTRFS_FILE_EXTENT_REG || 779 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 780 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 781 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); 782 extent_offset = btrfs_file_extent_offset(leaf, fi); 783 extent_end = key.offset + 784 btrfs_file_extent_num_bytes(leaf, fi); 785 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 786 extent_end = key.offset + 787 btrfs_file_extent_inline_len(leaf, 788 path->slots[0], fi); 789 } else { 790 /* can't happen */ 791 BUG(); 792 } 793 794 /* 795 * Don't skip extent items representing 0 byte lengths. They 796 * used to be created (bug) if while punching holes we hit 797 * -ENOSPC condition. So if we find one here, just ensure we 798 * delete it, otherwise we would insert a new file extent item 799 * with the same key (offset) as that 0 bytes length file 800 * extent item in the call to setup_items_for_insert() later 801 * in this function. 802 */ 803 if (extent_end == key.offset && extent_end >= search_start) { 804 last_end = extent_end; 805 goto delete_extent_item; 806 } 807 808 if (extent_end <= search_start) { 809 path->slots[0]++; 810 goto next_slot; 811 } 812 813 found = 1; 814 search_start = max(key.offset, start); 815 if (recow || !modify_tree) { 816 modify_tree = -1; 817 btrfs_release_path(path); 818 continue; 819 } 820 821 /* 822 * | - range to drop - | 823 * | -------- extent -------- | 824 */ 825 if (start > key.offset && end < extent_end) { 826 BUG_ON(del_nr > 0); 827 if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 828 ret = -EOPNOTSUPP; 829 break; 830 } 831 832 memcpy(&new_key, &key, sizeof(new_key)); 833 new_key.offset = start; 834 ret = btrfs_duplicate_item(trans, root, path, 835 &new_key); 836 if (ret == -EAGAIN) { 837 btrfs_release_path(path); 838 continue; 839 } 840 if (ret < 0) 841 break; 842 843 leaf = path->nodes[0]; 844 fi = btrfs_item_ptr(leaf, path->slots[0] - 1, 845 struct btrfs_file_extent_item); 846 btrfs_set_file_extent_num_bytes(leaf, fi, 847 start - key.offset); 848 849 fi = btrfs_item_ptr(leaf, path->slots[0], 850 struct btrfs_file_extent_item); 851 852 extent_offset += start - key.offset; 853 btrfs_set_file_extent_offset(leaf, fi, extent_offset); 854 btrfs_set_file_extent_num_bytes(leaf, fi, 855 extent_end - start); 856 btrfs_mark_buffer_dirty(leaf); 857 858 if (update_refs && disk_bytenr > 0) { 859 ret = btrfs_inc_extent_ref(trans, fs_info, 860 disk_bytenr, num_bytes, 0, 861 root->root_key.objectid, 862 new_key.objectid, 863 start - extent_offset); 864 BUG_ON(ret); /* -ENOMEM */ 865 } 866 key.offset = start; 867 } 868 /* 869 * From here on out we will have actually dropped something, so 870 * last_end can be updated. 871 */ 872 last_end = extent_end; 873 874 /* 875 * | ---- range to drop ----- | 876 * | -------- extent -------- | 877 */ 878 if (start <= key.offset && end < extent_end) { 879 if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 880 ret = -EOPNOTSUPP; 881 break; 882 } 883 884 memcpy(&new_key, &key, sizeof(new_key)); 885 new_key.offset = end; 886 btrfs_set_item_key_safe(fs_info, path, &new_key); 887 888 extent_offset += end - key.offset; 889 btrfs_set_file_extent_offset(leaf, fi, extent_offset); 890 btrfs_set_file_extent_num_bytes(leaf, fi, 891 extent_end - end); 892 btrfs_mark_buffer_dirty(leaf); 893 if (update_refs && disk_bytenr > 0) 894 inode_sub_bytes(inode, end - key.offset); 895 break; 896 } 897 898 search_start = extent_end; 899 /* 900 * | ---- range to drop ----- | 901 * | -------- extent -------- | 902 */ 903 if (start > key.offset && end >= extent_end) { 904 BUG_ON(del_nr > 0); 905 if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 906 ret = -EOPNOTSUPP; 907 break; 908 } 909 910 btrfs_set_file_extent_num_bytes(leaf, fi, 911 start - key.offset); 912 btrfs_mark_buffer_dirty(leaf); 913 if (update_refs && disk_bytenr > 0) 914 inode_sub_bytes(inode, extent_end - start); 915 if (end == extent_end) 916 break; 917 918 path->slots[0]++; 919 goto next_slot; 920 } 921 922 /* 923 * | ---- range to drop ----- | 924 * | ------ extent ------ | 925 */ 926 if (start <= key.offset && end >= extent_end) { 927 delete_extent_item: 928 if (del_nr == 0) { 929 del_slot = path->slots[0]; 930 del_nr = 1; 931 } else { 932 BUG_ON(del_slot + del_nr != path->slots[0]); 933 del_nr++; 934 } 935 936 if (update_refs && 937 extent_type == BTRFS_FILE_EXTENT_INLINE) { 938 inode_sub_bytes(inode, 939 extent_end - key.offset); 940 extent_end = ALIGN(extent_end, 941 fs_info->sectorsize); 942 } else if (update_refs && disk_bytenr > 0) { 943 ret = btrfs_free_extent(trans, fs_info, 944 disk_bytenr, num_bytes, 0, 945 root->root_key.objectid, 946 key.objectid, key.offset - 947 extent_offset); 948 BUG_ON(ret); /* -ENOMEM */ 949 inode_sub_bytes(inode, 950 extent_end - key.offset); 951 } 952 953 if (end == extent_end) 954 break; 955 956 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) { 957 path->slots[0]++; 958 goto next_slot; 959 } 960 961 ret = btrfs_del_items(trans, root, path, del_slot, 962 del_nr); 963 if (ret) { 964 btrfs_abort_transaction(trans, ret); 965 break; 966 } 967 968 del_nr = 0; 969 del_slot = 0; 970 971 btrfs_release_path(path); 972 continue; 973 } 974 975 BUG_ON(1); 976 } 977 978 if (!ret && del_nr > 0) { 979 /* 980 * Set path->slots[0] to first slot, so that after the delete 981 * if items are move off from our leaf to its immediate left or 982 * right neighbor leafs, we end up with a correct and adjusted 983 * path->slots[0] for our insertion (if replace_extent != 0). 984 */ 985 path->slots[0] = del_slot; 986 ret = btrfs_del_items(trans, root, path, del_slot, del_nr); 987 if (ret) 988 btrfs_abort_transaction(trans, ret); 989 } 990 991 leaf = path->nodes[0]; 992 /* 993 * If btrfs_del_items() was called, it might have deleted a leaf, in 994 * which case it unlocked our path, so check path->locks[0] matches a 995 * write lock. 996 */ 997 if (!ret && replace_extent && leafs_visited == 1 && 998 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING || 999 path->locks[0] == BTRFS_WRITE_LOCK) && 1000 btrfs_leaf_free_space(fs_info, leaf) >= 1001 sizeof(struct btrfs_item) + extent_item_size) { 1002 1003 key.objectid = ino; 1004 key.type = BTRFS_EXTENT_DATA_KEY; 1005 key.offset = start; 1006 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) { 1007 struct btrfs_key slot_key; 1008 1009 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]); 1010 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0) 1011 path->slots[0]++; 1012 } 1013 setup_items_for_insert(root, path, &key, 1014 &extent_item_size, 1015 extent_item_size, 1016 sizeof(struct btrfs_item) + 1017 extent_item_size, 1); 1018 *key_inserted = 1; 1019 } 1020 1021 if (!replace_extent || !(*key_inserted)) 1022 btrfs_release_path(path); 1023 if (drop_end) 1024 *drop_end = found ? min(end, last_end) : end; 1025 return ret; 1026 } 1027 1028 int btrfs_drop_extents(struct btrfs_trans_handle *trans, 1029 struct btrfs_root *root, struct inode *inode, u64 start, 1030 u64 end, int drop_cache) 1031 { 1032 struct btrfs_path *path; 1033 int ret; 1034 1035 path = btrfs_alloc_path(); 1036 if (!path) 1037 return -ENOMEM; 1038 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL, 1039 drop_cache, 0, 0, NULL); 1040 btrfs_free_path(path); 1041 return ret; 1042 } 1043 1044 static int extent_mergeable(struct extent_buffer *leaf, int slot, 1045 u64 objectid, u64 bytenr, u64 orig_offset, 1046 u64 *start, u64 *end) 1047 { 1048 struct btrfs_file_extent_item *fi; 1049 struct btrfs_key key; 1050 u64 extent_end; 1051 1052 if (slot < 0 || slot >= btrfs_header_nritems(leaf)) 1053 return 0; 1054 1055 btrfs_item_key_to_cpu(leaf, &key, slot); 1056 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY) 1057 return 0; 1058 1059 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 1060 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG || 1061 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr || 1062 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset || 1063 btrfs_file_extent_compression(leaf, fi) || 1064 btrfs_file_extent_encryption(leaf, fi) || 1065 btrfs_file_extent_other_encoding(leaf, fi)) 1066 return 0; 1067 1068 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); 1069 if ((*start && *start != key.offset) || (*end && *end != extent_end)) 1070 return 0; 1071 1072 *start = key.offset; 1073 *end = extent_end; 1074 return 1; 1075 } 1076 1077 /* 1078 * Mark extent in the range start - end as written. 1079 * 1080 * This changes extent type from 'pre-allocated' to 'regular'. If only 1081 * part of extent is marked as written, the extent will be split into 1082 * two or three. 1083 */ 1084 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans, 1085 struct inode *inode, u64 start, u64 end) 1086 { 1087 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1088 struct btrfs_root *root = BTRFS_I(inode)->root; 1089 struct extent_buffer *leaf; 1090 struct btrfs_path *path; 1091 struct btrfs_file_extent_item *fi; 1092 struct btrfs_key key; 1093 struct btrfs_key new_key; 1094 u64 bytenr; 1095 u64 num_bytes; 1096 u64 extent_end; 1097 u64 orig_offset; 1098 u64 other_start; 1099 u64 other_end; 1100 u64 split; 1101 int del_nr = 0; 1102 int del_slot = 0; 1103 int recow; 1104 int ret; 1105 u64 ino = btrfs_ino(inode); 1106 1107 path = btrfs_alloc_path(); 1108 if (!path) 1109 return -ENOMEM; 1110 again: 1111 recow = 0; 1112 split = start; 1113 key.objectid = ino; 1114 key.type = BTRFS_EXTENT_DATA_KEY; 1115 key.offset = split; 1116 1117 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 1118 if (ret < 0) 1119 goto out; 1120 if (ret > 0 && path->slots[0] > 0) 1121 path->slots[0]--; 1122 1123 leaf = path->nodes[0]; 1124 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 1125 if (key.objectid != ino || 1126 key.type != BTRFS_EXTENT_DATA_KEY) { 1127 ret = -EINVAL; 1128 btrfs_abort_transaction(trans, ret); 1129 goto out; 1130 } 1131 fi = btrfs_item_ptr(leaf, path->slots[0], 1132 struct btrfs_file_extent_item); 1133 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) { 1134 ret = -EINVAL; 1135 btrfs_abort_transaction(trans, ret); 1136 goto out; 1137 } 1138 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); 1139 if (key.offset > start || extent_end < end) { 1140 ret = -EINVAL; 1141 btrfs_abort_transaction(trans, ret); 1142 goto out; 1143 } 1144 1145 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 1146 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); 1147 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi); 1148 memcpy(&new_key, &key, sizeof(new_key)); 1149 1150 if (start == key.offset && end < extent_end) { 1151 other_start = 0; 1152 other_end = start; 1153 if (extent_mergeable(leaf, path->slots[0] - 1, 1154 ino, bytenr, orig_offset, 1155 &other_start, &other_end)) { 1156 new_key.offset = end; 1157 btrfs_set_item_key_safe(fs_info, path, &new_key); 1158 fi = btrfs_item_ptr(leaf, path->slots[0], 1159 struct btrfs_file_extent_item); 1160 btrfs_set_file_extent_generation(leaf, fi, 1161 trans->transid); 1162 btrfs_set_file_extent_num_bytes(leaf, fi, 1163 extent_end - end); 1164 btrfs_set_file_extent_offset(leaf, fi, 1165 end - orig_offset); 1166 fi = btrfs_item_ptr(leaf, path->slots[0] - 1, 1167 struct btrfs_file_extent_item); 1168 btrfs_set_file_extent_generation(leaf, fi, 1169 trans->transid); 1170 btrfs_set_file_extent_num_bytes(leaf, fi, 1171 end - other_start); 1172 btrfs_mark_buffer_dirty(leaf); 1173 goto out; 1174 } 1175 } 1176 1177 if (start > key.offset && end == extent_end) { 1178 other_start = end; 1179 other_end = 0; 1180 if (extent_mergeable(leaf, path->slots[0] + 1, 1181 ino, bytenr, orig_offset, 1182 &other_start, &other_end)) { 1183 fi = btrfs_item_ptr(leaf, path->slots[0], 1184 struct btrfs_file_extent_item); 1185 btrfs_set_file_extent_num_bytes(leaf, fi, 1186 start - key.offset); 1187 btrfs_set_file_extent_generation(leaf, fi, 1188 trans->transid); 1189 path->slots[0]++; 1190 new_key.offset = start; 1191 btrfs_set_item_key_safe(fs_info, path, &new_key); 1192 1193 fi = btrfs_item_ptr(leaf, path->slots[0], 1194 struct btrfs_file_extent_item); 1195 btrfs_set_file_extent_generation(leaf, fi, 1196 trans->transid); 1197 btrfs_set_file_extent_num_bytes(leaf, fi, 1198 other_end - start); 1199 btrfs_set_file_extent_offset(leaf, fi, 1200 start - orig_offset); 1201 btrfs_mark_buffer_dirty(leaf); 1202 goto out; 1203 } 1204 } 1205 1206 while (start > key.offset || end < extent_end) { 1207 if (key.offset == start) 1208 split = end; 1209 1210 new_key.offset = split; 1211 ret = btrfs_duplicate_item(trans, root, path, &new_key); 1212 if (ret == -EAGAIN) { 1213 btrfs_release_path(path); 1214 goto again; 1215 } 1216 if (ret < 0) { 1217 btrfs_abort_transaction(trans, ret); 1218 goto out; 1219 } 1220 1221 leaf = path->nodes[0]; 1222 fi = btrfs_item_ptr(leaf, path->slots[0] - 1, 1223 struct btrfs_file_extent_item); 1224 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 1225 btrfs_set_file_extent_num_bytes(leaf, fi, 1226 split - key.offset); 1227 1228 fi = btrfs_item_ptr(leaf, path->slots[0], 1229 struct btrfs_file_extent_item); 1230 1231 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 1232 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset); 1233 btrfs_set_file_extent_num_bytes(leaf, fi, 1234 extent_end - split); 1235 btrfs_mark_buffer_dirty(leaf); 1236 1237 ret = btrfs_inc_extent_ref(trans, fs_info, bytenr, num_bytes, 1238 0, root->root_key.objectid, 1239 ino, orig_offset); 1240 if (ret) { 1241 btrfs_abort_transaction(trans, ret); 1242 goto out; 1243 } 1244 1245 if (split == start) { 1246 key.offset = start; 1247 } else { 1248 if (start != key.offset) { 1249 ret = -EINVAL; 1250 btrfs_abort_transaction(trans, ret); 1251 goto out; 1252 } 1253 path->slots[0]--; 1254 extent_end = end; 1255 } 1256 recow = 1; 1257 } 1258 1259 other_start = end; 1260 other_end = 0; 1261 if (extent_mergeable(leaf, path->slots[0] + 1, 1262 ino, bytenr, orig_offset, 1263 &other_start, &other_end)) { 1264 if (recow) { 1265 btrfs_release_path(path); 1266 goto again; 1267 } 1268 extent_end = other_end; 1269 del_slot = path->slots[0] + 1; 1270 del_nr++; 1271 ret = btrfs_free_extent(trans, fs_info, bytenr, num_bytes, 1272 0, root->root_key.objectid, 1273 ino, orig_offset); 1274 if (ret) { 1275 btrfs_abort_transaction(trans, ret); 1276 goto out; 1277 } 1278 } 1279 other_start = 0; 1280 other_end = start; 1281 if (extent_mergeable(leaf, path->slots[0] - 1, 1282 ino, bytenr, orig_offset, 1283 &other_start, &other_end)) { 1284 if (recow) { 1285 btrfs_release_path(path); 1286 goto again; 1287 } 1288 key.offset = other_start; 1289 del_slot = path->slots[0]; 1290 del_nr++; 1291 ret = btrfs_free_extent(trans, fs_info, bytenr, num_bytes, 1292 0, root->root_key.objectid, 1293 ino, orig_offset); 1294 if (ret) { 1295 btrfs_abort_transaction(trans, ret); 1296 goto out; 1297 } 1298 } 1299 if (del_nr == 0) { 1300 fi = btrfs_item_ptr(leaf, path->slots[0], 1301 struct btrfs_file_extent_item); 1302 btrfs_set_file_extent_type(leaf, fi, 1303 BTRFS_FILE_EXTENT_REG); 1304 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 1305 btrfs_mark_buffer_dirty(leaf); 1306 } else { 1307 fi = btrfs_item_ptr(leaf, del_slot - 1, 1308 struct btrfs_file_extent_item); 1309 btrfs_set_file_extent_type(leaf, fi, 1310 BTRFS_FILE_EXTENT_REG); 1311 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 1312 btrfs_set_file_extent_num_bytes(leaf, fi, 1313 extent_end - key.offset); 1314 btrfs_mark_buffer_dirty(leaf); 1315 1316 ret = btrfs_del_items(trans, root, path, del_slot, del_nr); 1317 if (ret < 0) { 1318 btrfs_abort_transaction(trans, ret); 1319 goto out; 1320 } 1321 } 1322 out: 1323 btrfs_free_path(path); 1324 return 0; 1325 } 1326 1327 /* 1328 * on error we return an unlocked page and the error value 1329 * on success we return a locked page and 0 1330 */ 1331 static int prepare_uptodate_page(struct inode *inode, 1332 struct page *page, u64 pos, 1333 bool force_uptodate) 1334 { 1335 int ret = 0; 1336 1337 if (((pos & (PAGE_SIZE - 1)) || force_uptodate) && 1338 !PageUptodate(page)) { 1339 ret = btrfs_readpage(NULL, page); 1340 if (ret) 1341 return ret; 1342 lock_page(page); 1343 if (!PageUptodate(page)) { 1344 unlock_page(page); 1345 return -EIO; 1346 } 1347 if (page->mapping != inode->i_mapping) { 1348 unlock_page(page); 1349 return -EAGAIN; 1350 } 1351 } 1352 return 0; 1353 } 1354 1355 /* 1356 * this just gets pages into the page cache and locks them down. 1357 */ 1358 static noinline int prepare_pages(struct inode *inode, struct page **pages, 1359 size_t num_pages, loff_t pos, 1360 size_t write_bytes, bool force_uptodate) 1361 { 1362 int i; 1363 unsigned long index = pos >> PAGE_SHIFT; 1364 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); 1365 int err = 0; 1366 int faili; 1367 1368 for (i = 0; i < num_pages; i++) { 1369 again: 1370 pages[i] = find_or_create_page(inode->i_mapping, index + i, 1371 mask | __GFP_WRITE); 1372 if (!pages[i]) { 1373 faili = i - 1; 1374 err = -ENOMEM; 1375 goto fail; 1376 } 1377 1378 if (i == 0) 1379 err = prepare_uptodate_page(inode, pages[i], pos, 1380 force_uptodate); 1381 if (!err && i == num_pages - 1) 1382 err = prepare_uptodate_page(inode, pages[i], 1383 pos + write_bytes, false); 1384 if (err) { 1385 put_page(pages[i]); 1386 if (err == -EAGAIN) { 1387 err = 0; 1388 goto again; 1389 } 1390 faili = i - 1; 1391 goto fail; 1392 } 1393 wait_on_page_writeback(pages[i]); 1394 } 1395 1396 return 0; 1397 fail: 1398 while (faili >= 0) { 1399 unlock_page(pages[faili]); 1400 put_page(pages[faili]); 1401 faili--; 1402 } 1403 return err; 1404 1405 } 1406 1407 /* 1408 * This function locks the extent and properly waits for data=ordered extents 1409 * to finish before allowing the pages to be modified if need. 1410 * 1411 * The return value: 1412 * 1 - the extent is locked 1413 * 0 - the extent is not locked, and everything is OK 1414 * -EAGAIN - need re-prepare the pages 1415 * the other < 0 number - Something wrong happens 1416 */ 1417 static noinline int 1418 lock_and_cleanup_extent_if_need(struct inode *inode, struct page **pages, 1419 size_t num_pages, loff_t pos, 1420 size_t write_bytes, 1421 u64 *lockstart, u64 *lockend, 1422 struct extent_state **cached_state) 1423 { 1424 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1425 u64 start_pos; 1426 u64 last_pos; 1427 int i; 1428 int ret = 0; 1429 1430 start_pos = round_down(pos, fs_info->sectorsize); 1431 last_pos = start_pos 1432 + round_up(pos + write_bytes - start_pos, 1433 fs_info->sectorsize) - 1; 1434 1435 if (start_pos < inode->i_size) { 1436 struct btrfs_ordered_extent *ordered; 1437 lock_extent_bits(&BTRFS_I(inode)->io_tree, 1438 start_pos, last_pos, cached_state); 1439 ordered = btrfs_lookup_ordered_range(inode, start_pos, 1440 last_pos - start_pos + 1); 1441 if (ordered && 1442 ordered->file_offset + ordered->len > start_pos && 1443 ordered->file_offset <= last_pos) { 1444 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 1445 start_pos, last_pos, 1446 cached_state, GFP_NOFS); 1447 for (i = 0; i < num_pages; i++) { 1448 unlock_page(pages[i]); 1449 put_page(pages[i]); 1450 } 1451 btrfs_start_ordered_extent(inode, ordered, 1); 1452 btrfs_put_ordered_extent(ordered); 1453 return -EAGAIN; 1454 } 1455 if (ordered) 1456 btrfs_put_ordered_extent(ordered); 1457 1458 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos, 1459 last_pos, EXTENT_DIRTY | EXTENT_DELALLOC | 1460 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1461 0, 0, cached_state, GFP_NOFS); 1462 *lockstart = start_pos; 1463 *lockend = last_pos; 1464 ret = 1; 1465 } 1466 1467 for (i = 0; i < num_pages; i++) { 1468 if (clear_page_dirty_for_io(pages[i])) 1469 account_page_redirty(pages[i]); 1470 set_page_extent_mapped(pages[i]); 1471 WARN_ON(!PageLocked(pages[i])); 1472 } 1473 1474 return ret; 1475 } 1476 1477 static noinline int check_can_nocow(struct inode *inode, loff_t pos, 1478 size_t *write_bytes) 1479 { 1480 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1481 struct btrfs_root *root = BTRFS_I(inode)->root; 1482 struct btrfs_ordered_extent *ordered; 1483 u64 lockstart, lockend; 1484 u64 num_bytes; 1485 int ret; 1486 1487 ret = btrfs_start_write_no_snapshoting(root); 1488 if (!ret) 1489 return -ENOSPC; 1490 1491 lockstart = round_down(pos, fs_info->sectorsize); 1492 lockend = round_up(pos + *write_bytes, 1493 fs_info->sectorsize) - 1; 1494 1495 while (1) { 1496 lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend); 1497 ordered = btrfs_lookup_ordered_range(inode, lockstart, 1498 lockend - lockstart + 1); 1499 if (!ordered) { 1500 break; 1501 } 1502 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend); 1503 btrfs_start_ordered_extent(inode, ordered, 1); 1504 btrfs_put_ordered_extent(ordered); 1505 } 1506 1507 num_bytes = lockend - lockstart + 1; 1508 ret = can_nocow_extent(inode, lockstart, &num_bytes, NULL, NULL, NULL); 1509 if (ret <= 0) { 1510 ret = 0; 1511 btrfs_end_write_no_snapshoting(root); 1512 } else { 1513 *write_bytes = min_t(size_t, *write_bytes , 1514 num_bytes - pos + lockstart); 1515 } 1516 1517 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend); 1518 1519 return ret; 1520 } 1521 1522 static noinline ssize_t __btrfs_buffered_write(struct file *file, 1523 struct iov_iter *i, 1524 loff_t pos) 1525 { 1526 struct inode *inode = file_inode(file); 1527 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1528 struct btrfs_root *root = BTRFS_I(inode)->root; 1529 struct page **pages = NULL; 1530 struct extent_state *cached_state = NULL; 1531 u64 release_bytes = 0; 1532 u64 lockstart; 1533 u64 lockend; 1534 size_t num_written = 0; 1535 int nrptrs; 1536 int ret = 0; 1537 bool only_release_metadata = false; 1538 bool force_page_uptodate = false; 1539 bool need_unlock; 1540 1541 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE), 1542 PAGE_SIZE / (sizeof(struct page *))); 1543 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied); 1544 nrptrs = max(nrptrs, 8); 1545 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL); 1546 if (!pages) 1547 return -ENOMEM; 1548 1549 while (iov_iter_count(i) > 0) { 1550 size_t offset = pos & (PAGE_SIZE - 1); 1551 size_t sector_offset; 1552 size_t write_bytes = min(iov_iter_count(i), 1553 nrptrs * (size_t)PAGE_SIZE - 1554 offset); 1555 size_t num_pages = DIV_ROUND_UP(write_bytes + offset, 1556 PAGE_SIZE); 1557 size_t reserve_bytes; 1558 size_t dirty_pages; 1559 size_t copied; 1560 size_t dirty_sectors; 1561 size_t num_sectors; 1562 1563 WARN_ON(num_pages > nrptrs); 1564 1565 /* 1566 * Fault pages before locking them in prepare_pages 1567 * to avoid recursive lock 1568 */ 1569 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) { 1570 ret = -EFAULT; 1571 break; 1572 } 1573 1574 sector_offset = pos & (fs_info->sectorsize - 1); 1575 reserve_bytes = round_up(write_bytes + sector_offset, 1576 fs_info->sectorsize); 1577 1578 ret = btrfs_check_data_free_space(inode, pos, write_bytes); 1579 if (ret < 0) { 1580 if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | 1581 BTRFS_INODE_PREALLOC)) && 1582 check_can_nocow(inode, pos, &write_bytes) > 0) { 1583 /* 1584 * For nodata cow case, no need to reserve 1585 * data space. 1586 */ 1587 only_release_metadata = true; 1588 /* 1589 * our prealloc extent may be smaller than 1590 * write_bytes, so scale down. 1591 */ 1592 num_pages = DIV_ROUND_UP(write_bytes + offset, 1593 PAGE_SIZE); 1594 reserve_bytes = round_up(write_bytes + 1595 sector_offset, 1596 fs_info->sectorsize); 1597 } else { 1598 break; 1599 } 1600 } 1601 1602 ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes); 1603 if (ret) { 1604 if (!only_release_metadata) 1605 btrfs_free_reserved_data_space(inode, pos, 1606 write_bytes); 1607 else 1608 btrfs_end_write_no_snapshoting(root); 1609 break; 1610 } 1611 1612 release_bytes = reserve_bytes; 1613 need_unlock = false; 1614 again: 1615 /* 1616 * This is going to setup the pages array with the number of 1617 * pages we want, so we don't really need to worry about the 1618 * contents of pages from loop to loop 1619 */ 1620 ret = prepare_pages(inode, pages, num_pages, 1621 pos, write_bytes, 1622 force_page_uptodate); 1623 if (ret) 1624 break; 1625 1626 ret = lock_and_cleanup_extent_if_need(inode, pages, num_pages, 1627 pos, write_bytes, &lockstart, 1628 &lockend, &cached_state); 1629 if (ret < 0) { 1630 if (ret == -EAGAIN) 1631 goto again; 1632 break; 1633 } else if (ret > 0) { 1634 need_unlock = true; 1635 ret = 0; 1636 } 1637 1638 copied = btrfs_copy_from_user(pos, write_bytes, pages, i); 1639 1640 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes); 1641 dirty_sectors = round_up(copied + sector_offset, 1642 fs_info->sectorsize); 1643 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors); 1644 1645 /* 1646 * if we have trouble faulting in the pages, fall 1647 * back to one page at a time 1648 */ 1649 if (copied < write_bytes) 1650 nrptrs = 1; 1651 1652 if (copied == 0) { 1653 force_page_uptodate = true; 1654 dirty_sectors = 0; 1655 dirty_pages = 0; 1656 } else { 1657 force_page_uptodate = false; 1658 dirty_pages = DIV_ROUND_UP(copied + offset, 1659 PAGE_SIZE); 1660 } 1661 1662 /* 1663 * If we had a short copy we need to release the excess delaloc 1664 * bytes we reserved. We need to increment outstanding_extents 1665 * because btrfs_delalloc_release_space and 1666 * btrfs_delalloc_release_metadata will decrement it, but 1667 * we still have an outstanding extent for the chunk we actually 1668 * managed to copy. 1669 */ 1670 if (num_sectors > dirty_sectors) { 1671 /* release everything except the sectors we dirtied */ 1672 release_bytes -= dirty_sectors << 1673 fs_info->sb->s_blocksize_bits; 1674 if (copied > 0) { 1675 spin_lock(&BTRFS_I(inode)->lock); 1676 BTRFS_I(inode)->outstanding_extents++; 1677 spin_unlock(&BTRFS_I(inode)->lock); 1678 } 1679 if (only_release_metadata) { 1680 btrfs_delalloc_release_metadata(inode, 1681 release_bytes); 1682 } else { 1683 u64 __pos; 1684 1685 __pos = round_down(pos, 1686 fs_info->sectorsize) + 1687 (dirty_pages << PAGE_SHIFT); 1688 btrfs_delalloc_release_space(inode, __pos, 1689 release_bytes); 1690 } 1691 } 1692 1693 release_bytes = round_up(copied + sector_offset, 1694 fs_info->sectorsize); 1695 1696 if (copied > 0) 1697 ret = btrfs_dirty_pages(inode, pages, dirty_pages, 1698 pos, copied, NULL); 1699 if (need_unlock) 1700 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 1701 lockstart, lockend, &cached_state, 1702 GFP_NOFS); 1703 if (ret) { 1704 btrfs_drop_pages(pages, num_pages); 1705 break; 1706 } 1707 1708 release_bytes = 0; 1709 if (only_release_metadata) 1710 btrfs_end_write_no_snapshoting(root); 1711 1712 if (only_release_metadata && copied > 0) { 1713 lockstart = round_down(pos, 1714 fs_info->sectorsize); 1715 lockend = round_up(pos + copied, 1716 fs_info->sectorsize) - 1; 1717 1718 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 1719 lockend, EXTENT_NORESERVE, NULL, 1720 NULL, GFP_NOFS); 1721 only_release_metadata = false; 1722 } 1723 1724 btrfs_drop_pages(pages, num_pages); 1725 1726 cond_resched(); 1727 1728 balance_dirty_pages_ratelimited(inode->i_mapping); 1729 if (dirty_pages < (fs_info->nodesize >> PAGE_SHIFT) + 1) 1730 btrfs_btree_balance_dirty(fs_info); 1731 1732 pos += copied; 1733 num_written += copied; 1734 } 1735 1736 kfree(pages); 1737 1738 if (release_bytes) { 1739 if (only_release_metadata) { 1740 btrfs_end_write_no_snapshoting(root); 1741 btrfs_delalloc_release_metadata(inode, release_bytes); 1742 } else { 1743 btrfs_delalloc_release_space(inode, 1744 round_down(pos, fs_info->sectorsize), 1745 release_bytes); 1746 } 1747 } 1748 1749 return num_written ? num_written : ret; 1750 } 1751 1752 static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) 1753 { 1754 struct file *file = iocb->ki_filp; 1755 struct inode *inode = file_inode(file); 1756 loff_t pos = iocb->ki_pos; 1757 ssize_t written; 1758 ssize_t written_buffered; 1759 loff_t endbyte; 1760 int err; 1761 1762 written = generic_file_direct_write(iocb, from); 1763 1764 if (written < 0 || !iov_iter_count(from)) 1765 return written; 1766 1767 pos += written; 1768 written_buffered = __btrfs_buffered_write(file, from, pos); 1769 if (written_buffered < 0) { 1770 err = written_buffered; 1771 goto out; 1772 } 1773 /* 1774 * Ensure all data is persisted. We want the next direct IO read to be 1775 * able to read what was just written. 1776 */ 1777 endbyte = pos + written_buffered - 1; 1778 err = btrfs_fdatawrite_range(inode, pos, endbyte); 1779 if (err) 1780 goto out; 1781 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte); 1782 if (err) 1783 goto out; 1784 written += written_buffered; 1785 iocb->ki_pos = pos + written_buffered; 1786 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT, 1787 endbyte >> PAGE_SHIFT); 1788 out: 1789 return written ? written : err; 1790 } 1791 1792 static void update_time_for_write(struct inode *inode) 1793 { 1794 struct timespec now; 1795 1796 if (IS_NOCMTIME(inode)) 1797 return; 1798 1799 now = current_time(inode); 1800 if (!timespec_equal(&inode->i_mtime, &now)) 1801 inode->i_mtime = now; 1802 1803 if (!timespec_equal(&inode->i_ctime, &now)) 1804 inode->i_ctime = now; 1805 1806 if (IS_I_VERSION(inode)) 1807 inode_inc_iversion(inode); 1808 } 1809 1810 static ssize_t btrfs_file_write_iter(struct kiocb *iocb, 1811 struct iov_iter *from) 1812 { 1813 struct file *file = iocb->ki_filp; 1814 struct inode *inode = file_inode(file); 1815 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1816 struct btrfs_root *root = BTRFS_I(inode)->root; 1817 u64 start_pos; 1818 u64 end_pos; 1819 ssize_t num_written = 0; 1820 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host); 1821 ssize_t err; 1822 loff_t pos; 1823 size_t count; 1824 loff_t oldsize; 1825 int clean_page = 0; 1826 1827 inode_lock(inode); 1828 err = generic_write_checks(iocb, from); 1829 if (err <= 0) { 1830 inode_unlock(inode); 1831 return err; 1832 } 1833 1834 current->backing_dev_info = inode_to_bdi(inode); 1835 err = file_remove_privs(file); 1836 if (err) { 1837 inode_unlock(inode); 1838 goto out; 1839 } 1840 1841 /* 1842 * If BTRFS flips readonly due to some impossible error 1843 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR), 1844 * although we have opened a file as writable, we have 1845 * to stop this write operation to ensure FS consistency. 1846 */ 1847 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { 1848 inode_unlock(inode); 1849 err = -EROFS; 1850 goto out; 1851 } 1852 1853 /* 1854 * We reserve space for updating the inode when we reserve space for the 1855 * extent we are going to write, so we will enospc out there. We don't 1856 * need to start yet another transaction to update the inode as we will 1857 * update the inode when we finish writing whatever data we write. 1858 */ 1859 update_time_for_write(inode); 1860 1861 pos = iocb->ki_pos; 1862 count = iov_iter_count(from); 1863 start_pos = round_down(pos, fs_info->sectorsize); 1864 oldsize = i_size_read(inode); 1865 if (start_pos > oldsize) { 1866 /* Expand hole size to cover write data, preventing empty gap */ 1867 end_pos = round_up(pos + count, 1868 fs_info->sectorsize); 1869 err = btrfs_cont_expand(inode, oldsize, end_pos); 1870 if (err) { 1871 inode_unlock(inode); 1872 goto out; 1873 } 1874 if (start_pos > round_up(oldsize, fs_info->sectorsize)) 1875 clean_page = 1; 1876 } 1877 1878 if (sync) 1879 atomic_inc(&BTRFS_I(inode)->sync_writers); 1880 1881 if (iocb->ki_flags & IOCB_DIRECT) { 1882 num_written = __btrfs_direct_write(iocb, from); 1883 } else { 1884 num_written = __btrfs_buffered_write(file, from, pos); 1885 if (num_written > 0) 1886 iocb->ki_pos = pos + num_written; 1887 if (clean_page) 1888 pagecache_isize_extended(inode, oldsize, 1889 i_size_read(inode)); 1890 } 1891 1892 inode_unlock(inode); 1893 1894 /* 1895 * We also have to set last_sub_trans to the current log transid, 1896 * otherwise subsequent syncs to a file that's been synced in this 1897 * transaction will appear to have already occurred. 1898 */ 1899 spin_lock(&BTRFS_I(inode)->lock); 1900 BTRFS_I(inode)->last_sub_trans = root->log_transid; 1901 spin_unlock(&BTRFS_I(inode)->lock); 1902 if (num_written > 0) 1903 num_written = generic_write_sync(iocb, num_written); 1904 1905 if (sync) 1906 atomic_dec(&BTRFS_I(inode)->sync_writers); 1907 out: 1908 current->backing_dev_info = NULL; 1909 return num_written ? num_written : err; 1910 } 1911 1912 int btrfs_release_file(struct inode *inode, struct file *filp) 1913 { 1914 if (filp->private_data) 1915 btrfs_ioctl_trans_end(filp); 1916 /* 1917 * ordered_data_close is set by settattr when we are about to truncate 1918 * a file from a non-zero size to a zero size. This tries to 1919 * flush down new bytes that may have been written if the 1920 * application were using truncate to replace a file in place. 1921 */ 1922 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 1923 &BTRFS_I(inode)->runtime_flags)) 1924 filemap_flush(inode->i_mapping); 1925 return 0; 1926 } 1927 1928 static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end) 1929 { 1930 int ret; 1931 1932 atomic_inc(&BTRFS_I(inode)->sync_writers); 1933 ret = btrfs_fdatawrite_range(inode, start, end); 1934 atomic_dec(&BTRFS_I(inode)->sync_writers); 1935 1936 return ret; 1937 } 1938 1939 /* 1940 * fsync call for both files and directories. This logs the inode into 1941 * the tree log instead of forcing full commits whenever possible. 1942 * 1943 * It needs to call filemap_fdatawait so that all ordered extent updates are 1944 * in the metadata btree are up to date for copying to the log. 1945 * 1946 * It drops the inode mutex before doing the tree log commit. This is an 1947 * important optimization for directories because holding the mutex prevents 1948 * new operations on the dir while we write to disk. 1949 */ 1950 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) 1951 { 1952 struct dentry *dentry = file_dentry(file); 1953 struct inode *inode = d_inode(dentry); 1954 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 1955 struct btrfs_root *root = BTRFS_I(inode)->root; 1956 struct btrfs_trans_handle *trans; 1957 struct btrfs_log_ctx ctx; 1958 int ret = 0; 1959 bool full_sync = 0; 1960 u64 len; 1961 1962 /* 1963 * The range length can be represented by u64, we have to do the typecasts 1964 * to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync() 1965 */ 1966 len = (u64)end - (u64)start + 1; 1967 trace_btrfs_sync_file(file, datasync); 1968 1969 /* 1970 * We write the dirty pages in the range and wait until they complete 1971 * out of the ->i_mutex. If so, we can flush the dirty pages by 1972 * multi-task, and make the performance up. See 1973 * btrfs_wait_ordered_range for an explanation of the ASYNC check. 1974 */ 1975 ret = start_ordered_ops(inode, start, end); 1976 if (ret) 1977 return ret; 1978 1979 inode_lock(inode); 1980 atomic_inc(&root->log_batch); 1981 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 1982 &BTRFS_I(inode)->runtime_flags); 1983 /* 1984 * We might have have had more pages made dirty after calling 1985 * start_ordered_ops and before acquiring the inode's i_mutex. 1986 */ 1987 if (full_sync) { 1988 /* 1989 * For a full sync, we need to make sure any ordered operations 1990 * start and finish before we start logging the inode, so that 1991 * all extents are persisted and the respective file extent 1992 * items are in the fs/subvol btree. 1993 */ 1994 ret = btrfs_wait_ordered_range(inode, start, len); 1995 } else { 1996 /* 1997 * Start any new ordered operations before starting to log the 1998 * inode. We will wait for them to finish in btrfs_sync_log(). 1999 * 2000 * Right before acquiring the inode's mutex, we might have new 2001 * writes dirtying pages, which won't immediately start the 2002 * respective ordered operations - that is done through the 2003 * fill_delalloc callbacks invoked from the writepage and 2004 * writepages address space operations. So make sure we start 2005 * all ordered operations before starting to log our inode. Not 2006 * doing this means that while logging the inode, writeback 2007 * could start and invoke writepage/writepages, which would call 2008 * the fill_delalloc callbacks (cow_file_range, 2009 * submit_compressed_extents). These callbacks add first an 2010 * extent map to the modified list of extents and then create 2011 * the respective ordered operation, which means in 2012 * tree-log.c:btrfs_log_inode() we might capture all existing 2013 * ordered operations (with btrfs_get_logged_extents()) before 2014 * the fill_delalloc callback adds its ordered operation, and by 2015 * the time we visit the modified list of extent maps (with 2016 * btrfs_log_changed_extents()), we see and process the extent 2017 * map they created. We then use the extent map to construct a 2018 * file extent item for logging without waiting for the 2019 * respective ordered operation to finish - this file extent 2020 * item points to a disk location that might not have yet been 2021 * written to, containing random data - so after a crash a log 2022 * replay will make our inode have file extent items that point 2023 * to disk locations containing invalid data, as we returned 2024 * success to userspace without waiting for the respective 2025 * ordered operation to finish, because it wasn't captured by 2026 * btrfs_get_logged_extents(). 2027 */ 2028 ret = start_ordered_ops(inode, start, end); 2029 } 2030 if (ret) { 2031 inode_unlock(inode); 2032 goto out; 2033 } 2034 atomic_inc(&root->log_batch); 2035 2036 /* 2037 * If the last transaction that changed this file was before the current 2038 * transaction and we have the full sync flag set in our inode, we can 2039 * bail out now without any syncing. 2040 * 2041 * Note that we can't bail out if the full sync flag isn't set. This is 2042 * because when the full sync flag is set we start all ordered extents 2043 * and wait for them to fully complete - when they complete they update 2044 * the inode's last_trans field through: 2045 * 2046 * btrfs_finish_ordered_io() -> 2047 * btrfs_update_inode_fallback() -> 2048 * btrfs_update_inode() -> 2049 * btrfs_set_inode_last_trans() 2050 * 2051 * So we are sure that last_trans is up to date and can do this check to 2052 * bail out safely. For the fast path, when the full sync flag is not 2053 * set in our inode, we can not do it because we start only our ordered 2054 * extents and don't wait for them to complete (that is when 2055 * btrfs_finish_ordered_io runs), so here at this point their last_trans 2056 * value might be less than or equals to fs_info->last_trans_committed, 2057 * and setting a speculative last_trans for an inode when a buffered 2058 * write is made (such as fs_info->generation + 1 for example) would not 2059 * be reliable since after setting the value and before fsync is called 2060 * any number of transactions can start and commit (transaction kthread 2061 * commits the current transaction periodically), and a transaction 2062 * commit does not start nor waits for ordered extents to complete. 2063 */ 2064 smp_mb(); 2065 if (btrfs_inode_in_log(inode, fs_info->generation) || 2066 (full_sync && BTRFS_I(inode)->last_trans <= 2067 fs_info->last_trans_committed) || 2068 (!btrfs_have_ordered_extents_in_range(inode, start, len) && 2069 BTRFS_I(inode)->last_trans 2070 <= fs_info->last_trans_committed)) { 2071 /* 2072 * We've had everything committed since the last time we were 2073 * modified so clear this flag in case it was set for whatever 2074 * reason, it's no longer relevant. 2075 */ 2076 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 2077 &BTRFS_I(inode)->runtime_flags); 2078 /* 2079 * An ordered extent might have started before and completed 2080 * already with io errors, in which case the inode was not 2081 * updated and we end up here. So check the inode's mapping 2082 * flags for any errors that might have happened while doing 2083 * writeback of file data. 2084 */ 2085 ret = filemap_check_errors(inode->i_mapping); 2086 inode_unlock(inode); 2087 goto out; 2088 } 2089 2090 /* 2091 * ok we haven't committed the transaction yet, lets do a commit 2092 */ 2093 if (file->private_data) 2094 btrfs_ioctl_trans_end(file); 2095 2096 /* 2097 * We use start here because we will need to wait on the IO to complete 2098 * in btrfs_sync_log, which could require joining a transaction (for 2099 * example checking cross references in the nocow path). If we use join 2100 * here we could get into a situation where we're waiting on IO to 2101 * happen that is blocked on a transaction trying to commit. With start 2102 * we inc the extwriter counter, so we wait for all extwriters to exit 2103 * before we start blocking join'ers. This comment is to keep somebody 2104 * from thinking they are super smart and changing this to 2105 * btrfs_join_transaction *cough*Josef*cough*. 2106 */ 2107 trans = btrfs_start_transaction(root, 0); 2108 if (IS_ERR(trans)) { 2109 ret = PTR_ERR(trans); 2110 inode_unlock(inode); 2111 goto out; 2112 } 2113 trans->sync = true; 2114 2115 btrfs_init_log_ctx(&ctx, inode); 2116 2117 ret = btrfs_log_dentry_safe(trans, root, dentry, start, end, &ctx); 2118 if (ret < 0) { 2119 /* Fallthrough and commit/free transaction. */ 2120 ret = 1; 2121 } 2122 2123 /* we've logged all the items and now have a consistent 2124 * version of the file in the log. It is possible that 2125 * someone will come in and modify the file, but that's 2126 * fine because the log is consistent on disk, and we 2127 * have references to all of the file's extents 2128 * 2129 * It is possible that someone will come in and log the 2130 * file again, but that will end up using the synchronization 2131 * inside btrfs_sync_log to keep things safe. 2132 */ 2133 inode_unlock(inode); 2134 2135 /* 2136 * If any of the ordered extents had an error, just return it to user 2137 * space, so that the application knows some writes didn't succeed and 2138 * can take proper action (retry for e.g.). Blindly committing the 2139 * transaction in this case, would fool userspace that everything was 2140 * successful. And we also want to make sure our log doesn't contain 2141 * file extent items pointing to extents that weren't fully written to - 2142 * just like in the non fast fsync path, where we check for the ordered 2143 * operation's error flag before writing to the log tree and return -EIO 2144 * if any of them had this flag set (btrfs_wait_ordered_range) - 2145 * therefore we need to check for errors in the ordered operations, 2146 * which are indicated by ctx.io_err. 2147 */ 2148 if (ctx.io_err) { 2149 btrfs_end_transaction(trans); 2150 ret = ctx.io_err; 2151 goto out; 2152 } 2153 2154 if (ret != BTRFS_NO_LOG_SYNC) { 2155 if (!ret) { 2156 ret = btrfs_sync_log(trans, root, &ctx); 2157 if (!ret) { 2158 ret = btrfs_end_transaction(trans); 2159 goto out; 2160 } 2161 } 2162 if (!full_sync) { 2163 ret = btrfs_wait_ordered_range(inode, start, len); 2164 if (ret) { 2165 btrfs_end_transaction(trans); 2166 goto out; 2167 } 2168 } 2169 ret = btrfs_commit_transaction(trans); 2170 } else { 2171 ret = btrfs_end_transaction(trans); 2172 } 2173 out: 2174 return ret > 0 ? -EIO : ret; 2175 } 2176 2177 static const struct vm_operations_struct btrfs_file_vm_ops = { 2178 .fault = filemap_fault, 2179 .map_pages = filemap_map_pages, 2180 .page_mkwrite = btrfs_page_mkwrite, 2181 }; 2182 2183 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) 2184 { 2185 struct address_space *mapping = filp->f_mapping; 2186 2187 if (!mapping->a_ops->readpage) 2188 return -ENOEXEC; 2189 2190 file_accessed(filp); 2191 vma->vm_ops = &btrfs_file_vm_ops; 2192 2193 return 0; 2194 } 2195 2196 static int hole_mergeable(struct inode *inode, struct extent_buffer *leaf, 2197 int slot, u64 start, u64 end) 2198 { 2199 struct btrfs_file_extent_item *fi; 2200 struct btrfs_key key; 2201 2202 if (slot < 0 || slot >= btrfs_header_nritems(leaf)) 2203 return 0; 2204 2205 btrfs_item_key_to_cpu(leaf, &key, slot); 2206 if (key.objectid != btrfs_ino(inode) || 2207 key.type != BTRFS_EXTENT_DATA_KEY) 2208 return 0; 2209 2210 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 2211 2212 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) 2213 return 0; 2214 2215 if (btrfs_file_extent_disk_bytenr(leaf, fi)) 2216 return 0; 2217 2218 if (key.offset == end) 2219 return 1; 2220 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start) 2221 return 1; 2222 return 0; 2223 } 2224 2225 static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode, 2226 struct btrfs_path *path, u64 offset, u64 end) 2227 { 2228 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 2229 struct btrfs_root *root = BTRFS_I(inode)->root; 2230 struct extent_buffer *leaf; 2231 struct btrfs_file_extent_item *fi; 2232 struct extent_map *hole_em; 2233 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 2234 struct btrfs_key key; 2235 int ret; 2236 2237 if (btrfs_fs_incompat(fs_info, NO_HOLES)) 2238 goto out; 2239 2240 key.objectid = btrfs_ino(inode); 2241 key.type = BTRFS_EXTENT_DATA_KEY; 2242 key.offset = offset; 2243 2244 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 2245 if (ret <= 0) { 2246 /* 2247 * We should have dropped this offset, so if we find it then 2248 * something has gone horribly wrong. 2249 */ 2250 if (ret == 0) 2251 ret = -EINVAL; 2252 return ret; 2253 } 2254 2255 leaf = path->nodes[0]; 2256 if (hole_mergeable(inode, leaf, path->slots[0]-1, offset, end)) { 2257 u64 num_bytes; 2258 2259 path->slots[0]--; 2260 fi = btrfs_item_ptr(leaf, path->slots[0], 2261 struct btrfs_file_extent_item); 2262 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + 2263 end - offset; 2264 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); 2265 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); 2266 btrfs_set_file_extent_offset(leaf, fi, 0); 2267 btrfs_mark_buffer_dirty(leaf); 2268 goto out; 2269 } 2270 2271 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) { 2272 u64 num_bytes; 2273 2274 key.offset = offset; 2275 btrfs_set_item_key_safe(fs_info, path, &key); 2276 fi = btrfs_item_ptr(leaf, path->slots[0], 2277 struct btrfs_file_extent_item); 2278 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end - 2279 offset; 2280 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); 2281 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); 2282 btrfs_set_file_extent_offset(leaf, fi, 0); 2283 btrfs_mark_buffer_dirty(leaf); 2284 goto out; 2285 } 2286 btrfs_release_path(path); 2287 2288 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset, 2289 0, 0, end - offset, 0, end - offset, 2290 0, 0, 0); 2291 if (ret) 2292 return ret; 2293 2294 out: 2295 btrfs_release_path(path); 2296 2297 hole_em = alloc_extent_map(); 2298 if (!hole_em) { 2299 btrfs_drop_extent_cache(inode, offset, end - 1, 0); 2300 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 2301 &BTRFS_I(inode)->runtime_flags); 2302 } else { 2303 hole_em->start = offset; 2304 hole_em->len = end - offset; 2305 hole_em->ram_bytes = hole_em->len; 2306 hole_em->orig_start = offset; 2307 2308 hole_em->block_start = EXTENT_MAP_HOLE; 2309 hole_em->block_len = 0; 2310 hole_em->orig_block_len = 0; 2311 hole_em->bdev = fs_info->fs_devices->latest_bdev; 2312 hole_em->compress_type = BTRFS_COMPRESS_NONE; 2313 hole_em->generation = trans->transid; 2314 2315 do { 2316 btrfs_drop_extent_cache(inode, offset, end - 1, 0); 2317 write_lock(&em_tree->lock); 2318 ret = add_extent_mapping(em_tree, hole_em, 1); 2319 write_unlock(&em_tree->lock); 2320 } while (ret == -EEXIST); 2321 free_extent_map(hole_em); 2322 if (ret) 2323 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 2324 &BTRFS_I(inode)->runtime_flags); 2325 } 2326 2327 return 0; 2328 } 2329 2330 /* 2331 * Find a hole extent on given inode and change start/len to the end of hole 2332 * extent.(hole/vacuum extent whose em->start <= start && 2333 * em->start + em->len > start) 2334 * When a hole extent is found, return 1 and modify start/len. 2335 */ 2336 static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len) 2337 { 2338 struct extent_map *em; 2339 int ret = 0; 2340 2341 em = btrfs_get_extent(inode, NULL, 0, *start, *len, 0); 2342 if (IS_ERR_OR_NULL(em)) { 2343 if (!em) 2344 ret = -ENOMEM; 2345 else 2346 ret = PTR_ERR(em); 2347 return ret; 2348 } 2349 2350 /* Hole or vacuum extent(only exists in no-hole mode) */ 2351 if (em->block_start == EXTENT_MAP_HOLE) { 2352 ret = 1; 2353 *len = em->start + em->len > *start + *len ? 2354 0 : *start + *len - em->start - em->len; 2355 *start = em->start + em->len; 2356 } 2357 free_extent_map(em); 2358 return ret; 2359 } 2360 2361 static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len) 2362 { 2363 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 2364 struct btrfs_root *root = BTRFS_I(inode)->root; 2365 struct extent_state *cached_state = NULL; 2366 struct btrfs_path *path; 2367 struct btrfs_block_rsv *rsv; 2368 struct btrfs_trans_handle *trans; 2369 u64 lockstart; 2370 u64 lockend; 2371 u64 tail_start; 2372 u64 tail_len; 2373 u64 orig_start = offset; 2374 u64 cur_offset; 2375 u64 min_size = btrfs_calc_trans_metadata_size(fs_info, 1); 2376 u64 drop_end; 2377 int ret = 0; 2378 int err = 0; 2379 unsigned int rsv_count; 2380 bool same_block; 2381 bool no_holes = btrfs_fs_incompat(fs_info, NO_HOLES); 2382 u64 ino_size; 2383 bool truncated_block = false; 2384 bool updated_inode = false; 2385 2386 ret = btrfs_wait_ordered_range(inode, offset, len); 2387 if (ret) 2388 return ret; 2389 2390 inode_lock(inode); 2391 ino_size = round_up(inode->i_size, fs_info->sectorsize); 2392 ret = find_first_non_hole(inode, &offset, &len); 2393 if (ret < 0) 2394 goto out_only_mutex; 2395 if (ret && !len) { 2396 /* Already in a large hole */ 2397 ret = 0; 2398 goto out_only_mutex; 2399 } 2400 2401 lockstart = round_up(offset, btrfs_inode_sectorsize(inode)); 2402 lockend = round_down(offset + len, 2403 btrfs_inode_sectorsize(inode)) - 1; 2404 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset)) 2405 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)); 2406 /* 2407 * We needn't truncate any block which is beyond the end of the file 2408 * because we are sure there is no data there. 2409 */ 2410 /* 2411 * Only do this if we are in the same block and we aren't doing the 2412 * entire block. 2413 */ 2414 if (same_block && len < fs_info->sectorsize) { 2415 if (offset < ino_size) { 2416 truncated_block = true; 2417 ret = btrfs_truncate_block(inode, offset, len, 0); 2418 } else { 2419 ret = 0; 2420 } 2421 goto out_only_mutex; 2422 } 2423 2424 /* zero back part of the first block */ 2425 if (offset < ino_size) { 2426 truncated_block = true; 2427 ret = btrfs_truncate_block(inode, offset, 0, 0); 2428 if (ret) { 2429 inode_unlock(inode); 2430 return ret; 2431 } 2432 } 2433 2434 /* Check the aligned pages after the first unaligned page, 2435 * if offset != orig_start, which means the first unaligned page 2436 * including several following pages are already in holes, 2437 * the extra check can be skipped */ 2438 if (offset == orig_start) { 2439 /* after truncate page, check hole again */ 2440 len = offset + len - lockstart; 2441 offset = lockstart; 2442 ret = find_first_non_hole(inode, &offset, &len); 2443 if (ret < 0) 2444 goto out_only_mutex; 2445 if (ret && !len) { 2446 ret = 0; 2447 goto out_only_mutex; 2448 } 2449 lockstart = offset; 2450 } 2451 2452 /* Check the tail unaligned part is in a hole */ 2453 tail_start = lockend + 1; 2454 tail_len = offset + len - tail_start; 2455 if (tail_len) { 2456 ret = find_first_non_hole(inode, &tail_start, &tail_len); 2457 if (unlikely(ret < 0)) 2458 goto out_only_mutex; 2459 if (!ret) { 2460 /* zero the front end of the last page */ 2461 if (tail_start + tail_len < ino_size) { 2462 truncated_block = true; 2463 ret = btrfs_truncate_block(inode, 2464 tail_start + tail_len, 2465 0, 1); 2466 if (ret) 2467 goto out_only_mutex; 2468 } 2469 } 2470 } 2471 2472 if (lockend < lockstart) { 2473 ret = 0; 2474 goto out_only_mutex; 2475 } 2476 2477 while (1) { 2478 struct btrfs_ordered_extent *ordered; 2479 2480 truncate_pagecache_range(inode, lockstart, lockend); 2481 2482 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 2483 &cached_state); 2484 ordered = btrfs_lookup_first_ordered_extent(inode, lockend); 2485 2486 /* 2487 * We need to make sure we have no ordered extents in this range 2488 * and nobody raced in and read a page in this range, if we did 2489 * we need to try again. 2490 */ 2491 if ((!ordered || 2492 (ordered->file_offset + ordered->len <= lockstart || 2493 ordered->file_offset > lockend)) && 2494 !btrfs_page_exists_in_range(inode, lockstart, lockend)) { 2495 if (ordered) 2496 btrfs_put_ordered_extent(ordered); 2497 break; 2498 } 2499 if (ordered) 2500 btrfs_put_ordered_extent(ordered); 2501 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, 2502 lockend, &cached_state, GFP_NOFS); 2503 ret = btrfs_wait_ordered_range(inode, lockstart, 2504 lockend - lockstart + 1); 2505 if (ret) { 2506 inode_unlock(inode); 2507 return ret; 2508 } 2509 } 2510 2511 path = btrfs_alloc_path(); 2512 if (!path) { 2513 ret = -ENOMEM; 2514 goto out; 2515 } 2516 2517 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP); 2518 if (!rsv) { 2519 ret = -ENOMEM; 2520 goto out_free; 2521 } 2522 rsv->size = btrfs_calc_trans_metadata_size(fs_info, 1); 2523 rsv->failfast = 1; 2524 2525 /* 2526 * 1 - update the inode 2527 * 1 - removing the extents in the range 2528 * 1 - adding the hole extent if no_holes isn't set 2529 */ 2530 rsv_count = no_holes ? 2 : 3; 2531 trans = btrfs_start_transaction(root, rsv_count); 2532 if (IS_ERR(trans)) { 2533 err = PTR_ERR(trans); 2534 goto out_free; 2535 } 2536 2537 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv, 2538 min_size, 0); 2539 BUG_ON(ret); 2540 trans->block_rsv = rsv; 2541 2542 cur_offset = lockstart; 2543 len = lockend - cur_offset; 2544 while (cur_offset < lockend) { 2545 ret = __btrfs_drop_extents(trans, root, inode, path, 2546 cur_offset, lockend + 1, 2547 &drop_end, 1, 0, 0, NULL); 2548 if (ret != -ENOSPC) 2549 break; 2550 2551 trans->block_rsv = &fs_info->trans_block_rsv; 2552 2553 if (cur_offset < drop_end && cur_offset < ino_size) { 2554 ret = fill_holes(trans, inode, path, cur_offset, 2555 drop_end); 2556 if (ret) { 2557 /* 2558 * If we failed then we didn't insert our hole 2559 * entries for the area we dropped, so now the 2560 * fs is corrupted, so we must abort the 2561 * transaction. 2562 */ 2563 btrfs_abort_transaction(trans, ret); 2564 err = ret; 2565 break; 2566 } 2567 } 2568 2569 cur_offset = drop_end; 2570 2571 ret = btrfs_update_inode(trans, root, inode); 2572 if (ret) { 2573 err = ret; 2574 break; 2575 } 2576 2577 btrfs_end_transaction(trans); 2578 btrfs_btree_balance_dirty(fs_info); 2579 2580 trans = btrfs_start_transaction(root, rsv_count); 2581 if (IS_ERR(trans)) { 2582 ret = PTR_ERR(trans); 2583 trans = NULL; 2584 break; 2585 } 2586 2587 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, 2588 rsv, min_size, 0); 2589 BUG_ON(ret); /* shouldn't happen */ 2590 trans->block_rsv = rsv; 2591 2592 ret = find_first_non_hole(inode, &cur_offset, &len); 2593 if (unlikely(ret < 0)) 2594 break; 2595 if (ret && !len) { 2596 ret = 0; 2597 break; 2598 } 2599 } 2600 2601 if (ret) { 2602 err = ret; 2603 goto out_trans; 2604 } 2605 2606 trans->block_rsv = &fs_info->trans_block_rsv; 2607 /* 2608 * If we are using the NO_HOLES feature we might have had already an 2609 * hole that overlaps a part of the region [lockstart, lockend] and 2610 * ends at (or beyond) lockend. Since we have no file extent items to 2611 * represent holes, drop_end can be less than lockend and so we must 2612 * make sure we have an extent map representing the existing hole (the 2613 * call to __btrfs_drop_extents() might have dropped the existing extent 2614 * map representing the existing hole), otherwise the fast fsync path 2615 * will not record the existence of the hole region 2616 * [existing_hole_start, lockend]. 2617 */ 2618 if (drop_end <= lockend) 2619 drop_end = lockend + 1; 2620 /* 2621 * Don't insert file hole extent item if it's for a range beyond eof 2622 * (because it's useless) or if it represents a 0 bytes range (when 2623 * cur_offset == drop_end). 2624 */ 2625 if (cur_offset < ino_size && cur_offset < drop_end) { 2626 ret = fill_holes(trans, inode, path, cur_offset, drop_end); 2627 if (ret) { 2628 /* Same comment as above. */ 2629 btrfs_abort_transaction(trans, ret); 2630 err = ret; 2631 goto out_trans; 2632 } 2633 } 2634 2635 out_trans: 2636 if (!trans) 2637 goto out_free; 2638 2639 inode_inc_iversion(inode); 2640 inode->i_mtime = inode->i_ctime = current_time(inode); 2641 2642 trans->block_rsv = &fs_info->trans_block_rsv; 2643 ret = btrfs_update_inode(trans, root, inode); 2644 updated_inode = true; 2645 btrfs_end_transaction(trans); 2646 btrfs_btree_balance_dirty(fs_info); 2647 out_free: 2648 btrfs_free_path(path); 2649 btrfs_free_block_rsv(fs_info, rsv); 2650 out: 2651 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, 2652 &cached_state, GFP_NOFS); 2653 out_only_mutex: 2654 if (!updated_inode && truncated_block && !ret && !err) { 2655 /* 2656 * If we only end up zeroing part of a page, we still need to 2657 * update the inode item, so that all the time fields are 2658 * updated as well as the necessary btrfs inode in memory fields 2659 * for detecting, at fsync time, if the inode isn't yet in the 2660 * log tree or it's there but not up to date. 2661 */ 2662 trans = btrfs_start_transaction(root, 1); 2663 if (IS_ERR(trans)) { 2664 err = PTR_ERR(trans); 2665 } else { 2666 err = btrfs_update_inode(trans, root, inode); 2667 ret = btrfs_end_transaction(trans); 2668 } 2669 } 2670 inode_unlock(inode); 2671 if (ret && !err) 2672 err = ret; 2673 return err; 2674 } 2675 2676 /* Helper structure to record which range is already reserved */ 2677 struct falloc_range { 2678 struct list_head list; 2679 u64 start; 2680 u64 len; 2681 }; 2682 2683 /* 2684 * Helper function to add falloc range 2685 * 2686 * Caller should have locked the larger range of extent containing 2687 * [start, len) 2688 */ 2689 static int add_falloc_range(struct list_head *head, u64 start, u64 len) 2690 { 2691 struct falloc_range *prev = NULL; 2692 struct falloc_range *range = NULL; 2693 2694 if (list_empty(head)) 2695 goto insert; 2696 2697 /* 2698 * As fallocate iterate by bytenr order, we only need to check 2699 * the last range. 2700 */ 2701 prev = list_entry(head->prev, struct falloc_range, list); 2702 if (prev->start + prev->len == start) { 2703 prev->len += len; 2704 return 0; 2705 } 2706 insert: 2707 range = kmalloc(sizeof(*range), GFP_KERNEL); 2708 if (!range) 2709 return -ENOMEM; 2710 range->start = start; 2711 range->len = len; 2712 list_add_tail(&range->list, head); 2713 return 0; 2714 } 2715 2716 static long btrfs_fallocate(struct file *file, int mode, 2717 loff_t offset, loff_t len) 2718 { 2719 struct inode *inode = file_inode(file); 2720 struct extent_state *cached_state = NULL; 2721 struct falloc_range *range; 2722 struct falloc_range *tmp; 2723 struct list_head reserve_list; 2724 u64 cur_offset; 2725 u64 last_byte; 2726 u64 alloc_start; 2727 u64 alloc_end; 2728 u64 alloc_hint = 0; 2729 u64 locked_end; 2730 u64 actual_end = 0; 2731 struct extent_map *em; 2732 int blocksize = btrfs_inode_sectorsize(inode); 2733 int ret; 2734 2735 alloc_start = round_down(offset, blocksize); 2736 alloc_end = round_up(offset + len, blocksize); 2737 cur_offset = alloc_start; 2738 2739 /* Make sure we aren't being give some crap mode */ 2740 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) 2741 return -EOPNOTSUPP; 2742 2743 if (mode & FALLOC_FL_PUNCH_HOLE) 2744 return btrfs_punch_hole(inode, offset, len); 2745 2746 /* 2747 * Only trigger disk allocation, don't trigger qgroup reserve 2748 * 2749 * For qgroup space, it will be checked later. 2750 */ 2751 ret = btrfs_alloc_data_chunk_ondemand(inode, alloc_end - alloc_start); 2752 if (ret < 0) 2753 return ret; 2754 2755 inode_lock(inode); 2756 2757 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) { 2758 ret = inode_newsize_ok(inode, offset + len); 2759 if (ret) 2760 goto out; 2761 } 2762 2763 /* 2764 * TODO: Move these two operations after we have checked 2765 * accurate reserved space, or fallocate can still fail but 2766 * with page truncated or size expanded. 2767 * 2768 * But that's a minor problem and won't do much harm BTW. 2769 */ 2770 if (alloc_start > inode->i_size) { 2771 ret = btrfs_cont_expand(inode, i_size_read(inode), 2772 alloc_start); 2773 if (ret) 2774 goto out; 2775 } else if (offset + len > inode->i_size) { 2776 /* 2777 * If we are fallocating from the end of the file onward we 2778 * need to zero out the end of the block if i_size lands in the 2779 * middle of a block. 2780 */ 2781 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0); 2782 if (ret) 2783 goto out; 2784 } 2785 2786 /* 2787 * wait for ordered IO before we have any locks. We'll loop again 2788 * below with the locks held. 2789 */ 2790 ret = btrfs_wait_ordered_range(inode, alloc_start, 2791 alloc_end - alloc_start); 2792 if (ret) 2793 goto out; 2794 2795 locked_end = alloc_end - 1; 2796 while (1) { 2797 struct btrfs_ordered_extent *ordered; 2798 2799 /* the extent lock is ordered inside the running 2800 * transaction 2801 */ 2802 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start, 2803 locked_end, &cached_state); 2804 ordered = btrfs_lookup_first_ordered_extent(inode, 2805 alloc_end - 1); 2806 if (ordered && 2807 ordered->file_offset + ordered->len > alloc_start && 2808 ordered->file_offset < alloc_end) { 2809 btrfs_put_ordered_extent(ordered); 2810 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 2811 alloc_start, locked_end, 2812 &cached_state, GFP_KERNEL); 2813 /* 2814 * we can't wait on the range with the transaction 2815 * running or with the extent lock held 2816 */ 2817 ret = btrfs_wait_ordered_range(inode, alloc_start, 2818 alloc_end - alloc_start); 2819 if (ret) 2820 goto out; 2821 } else { 2822 if (ordered) 2823 btrfs_put_ordered_extent(ordered); 2824 break; 2825 } 2826 } 2827 2828 /* First, check if we exceed the qgroup limit */ 2829 INIT_LIST_HEAD(&reserve_list); 2830 while (1) { 2831 em = btrfs_get_extent(inode, NULL, 0, cur_offset, 2832 alloc_end - cur_offset, 0); 2833 if (IS_ERR_OR_NULL(em)) { 2834 if (!em) 2835 ret = -ENOMEM; 2836 else 2837 ret = PTR_ERR(em); 2838 break; 2839 } 2840 last_byte = min(extent_map_end(em), alloc_end); 2841 actual_end = min_t(u64, extent_map_end(em), offset + len); 2842 last_byte = ALIGN(last_byte, blocksize); 2843 if (em->block_start == EXTENT_MAP_HOLE || 2844 (cur_offset >= inode->i_size && 2845 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { 2846 ret = add_falloc_range(&reserve_list, cur_offset, 2847 last_byte - cur_offset); 2848 if (ret < 0) { 2849 free_extent_map(em); 2850 break; 2851 } 2852 ret = btrfs_qgroup_reserve_data(inode, cur_offset, 2853 last_byte - cur_offset); 2854 if (ret < 0) 2855 break; 2856 } else { 2857 /* 2858 * Do not need to reserve unwritten extent for this 2859 * range, free reserved data space first, otherwise 2860 * it'll result in false ENOSPC error. 2861 */ 2862 btrfs_free_reserved_data_space(inode, cur_offset, 2863 last_byte - cur_offset); 2864 } 2865 free_extent_map(em); 2866 cur_offset = last_byte; 2867 if (cur_offset >= alloc_end) 2868 break; 2869 } 2870 2871 /* 2872 * If ret is still 0, means we're OK to fallocate. 2873 * Or just cleanup the list and exit. 2874 */ 2875 list_for_each_entry_safe(range, tmp, &reserve_list, list) { 2876 if (!ret) 2877 ret = btrfs_prealloc_file_range(inode, mode, 2878 range->start, 2879 range->len, 1 << inode->i_blkbits, 2880 offset + len, &alloc_hint); 2881 else 2882 btrfs_free_reserved_data_space(inode, range->start, 2883 range->len); 2884 list_del(&range->list); 2885 kfree(range); 2886 } 2887 if (ret < 0) 2888 goto out_unlock; 2889 2890 if (actual_end > inode->i_size && 2891 !(mode & FALLOC_FL_KEEP_SIZE)) { 2892 struct btrfs_trans_handle *trans; 2893 struct btrfs_root *root = BTRFS_I(inode)->root; 2894 2895 /* 2896 * We didn't need to allocate any more space, but we 2897 * still extended the size of the file so we need to 2898 * update i_size and the inode item. 2899 */ 2900 trans = btrfs_start_transaction(root, 1); 2901 if (IS_ERR(trans)) { 2902 ret = PTR_ERR(trans); 2903 } else { 2904 inode->i_ctime = current_time(inode); 2905 i_size_write(inode, actual_end); 2906 btrfs_ordered_update_i_size(inode, actual_end, NULL); 2907 ret = btrfs_update_inode(trans, root, inode); 2908 if (ret) 2909 btrfs_end_transaction(trans); 2910 else 2911 ret = btrfs_end_transaction(trans); 2912 } 2913 } 2914 out_unlock: 2915 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end, 2916 &cached_state, GFP_KERNEL); 2917 out: 2918 inode_unlock(inode); 2919 /* Let go of our reservation. */ 2920 if (ret != 0) 2921 btrfs_free_reserved_data_space(inode, alloc_start, 2922 alloc_end - cur_offset); 2923 return ret; 2924 } 2925 2926 static int find_desired_extent(struct inode *inode, loff_t *offset, int whence) 2927 { 2928 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 2929 struct extent_map *em = NULL; 2930 struct extent_state *cached_state = NULL; 2931 u64 lockstart; 2932 u64 lockend; 2933 u64 start; 2934 u64 len; 2935 int ret = 0; 2936 2937 if (inode->i_size == 0) 2938 return -ENXIO; 2939 2940 /* 2941 * *offset can be negative, in this case we start finding DATA/HOLE from 2942 * the very start of the file. 2943 */ 2944 start = max_t(loff_t, 0, *offset); 2945 2946 lockstart = round_down(start, fs_info->sectorsize); 2947 lockend = round_up(i_size_read(inode), 2948 fs_info->sectorsize); 2949 if (lockend <= lockstart) 2950 lockend = lockstart + fs_info->sectorsize; 2951 lockend--; 2952 len = lockend - lockstart + 1; 2953 2954 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 2955 &cached_state); 2956 2957 while (start < inode->i_size) { 2958 em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0); 2959 if (IS_ERR(em)) { 2960 ret = PTR_ERR(em); 2961 em = NULL; 2962 break; 2963 } 2964 2965 if (whence == SEEK_HOLE && 2966 (em->block_start == EXTENT_MAP_HOLE || 2967 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) 2968 break; 2969 else if (whence == SEEK_DATA && 2970 (em->block_start != EXTENT_MAP_HOLE && 2971 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) 2972 break; 2973 2974 start = em->start + em->len; 2975 free_extent_map(em); 2976 em = NULL; 2977 cond_resched(); 2978 } 2979 free_extent_map(em); 2980 if (!ret) { 2981 if (whence == SEEK_DATA && start >= inode->i_size) 2982 ret = -ENXIO; 2983 else 2984 *offset = min_t(loff_t, start, inode->i_size); 2985 } 2986 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, 2987 &cached_state, GFP_NOFS); 2988 return ret; 2989 } 2990 2991 static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence) 2992 { 2993 struct inode *inode = file->f_mapping->host; 2994 int ret; 2995 2996 inode_lock(inode); 2997 switch (whence) { 2998 case SEEK_END: 2999 case SEEK_CUR: 3000 offset = generic_file_llseek(file, offset, whence); 3001 goto out; 3002 case SEEK_DATA: 3003 case SEEK_HOLE: 3004 if (offset >= i_size_read(inode)) { 3005 inode_unlock(inode); 3006 return -ENXIO; 3007 } 3008 3009 ret = find_desired_extent(inode, &offset, whence); 3010 if (ret) { 3011 inode_unlock(inode); 3012 return ret; 3013 } 3014 } 3015 3016 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes); 3017 out: 3018 inode_unlock(inode); 3019 return offset; 3020 } 3021 3022 const struct file_operations btrfs_file_operations = { 3023 .llseek = btrfs_file_llseek, 3024 .read_iter = generic_file_read_iter, 3025 .splice_read = generic_file_splice_read, 3026 .write_iter = btrfs_file_write_iter, 3027 .mmap = btrfs_file_mmap, 3028 .open = generic_file_open, 3029 .release = btrfs_release_file, 3030 .fsync = btrfs_sync_file, 3031 .fallocate = btrfs_fallocate, 3032 .unlocked_ioctl = btrfs_ioctl, 3033 #ifdef CONFIG_COMPAT 3034 .compat_ioctl = btrfs_compat_ioctl, 3035 #endif 3036 .clone_file_range = btrfs_clone_file_range, 3037 .dedupe_file_range = btrfs_dedupe_file_range, 3038 }; 3039 3040 void btrfs_auto_defrag_exit(void) 3041 { 3042 kmem_cache_destroy(btrfs_inode_defrag_cachep); 3043 } 3044 3045 int btrfs_auto_defrag_init(void) 3046 { 3047 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag", 3048 sizeof(struct inode_defrag), 0, 3049 SLAB_MEM_SPREAD, 3050 NULL); 3051 if (!btrfs_inode_defrag_cachep) 3052 return -ENOMEM; 3053 3054 return 0; 3055 } 3056 3057 int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end) 3058 { 3059 int ret; 3060 3061 /* 3062 * So with compression we will find and lock a dirty page and clear the 3063 * first one as dirty, setup an async extent, and immediately return 3064 * with the entire range locked but with nobody actually marked with 3065 * writeback. So we can't just filemap_write_and_wait_range() and 3066 * expect it to work since it will just kick off a thread to do the 3067 * actual work. So we need to call filemap_fdatawrite_range _again_ 3068 * since it will wait on the page lock, which won't be unlocked until 3069 * after the pages have been marked as writeback and so we're good to go 3070 * from there. We have to do this otherwise we'll miss the ordered 3071 * extents and that results in badness. Please Josef, do not think you 3072 * know better and pull this out at some point in the future, it is 3073 * right and you are wrong. 3074 */ 3075 ret = filemap_fdatawrite_range(inode->i_mapping, start, end); 3076 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 3077 &BTRFS_I(inode)->runtime_flags)) 3078 ret = filemap_fdatawrite_range(inode->i_mapping, start, end); 3079 3080 return ret; 3081 } 3082