1 #include <linux/bitops.h> 2 #include <linux/slab.h> 3 #include <linux/bio.h> 4 #include <linux/mm.h> 5 #include <linux/gfp.h> 6 #include <linux/pagemap.h> 7 #include <linux/page-flags.h> 8 #include <linux/module.h> 9 #include <linux/spinlock.h> 10 #include <linux/blkdev.h> 11 #include <linux/swap.h> 12 #include "extent_map.h" 13 14 /* temporary define until extent_map moves out of btrfs */ 15 struct kmem_cache *btrfs_cache_create(const char *name, size_t size, 16 unsigned long extra_flags, 17 void (*ctor)(void *, struct kmem_cache *, 18 unsigned long)); 19 20 static struct kmem_cache *extent_map_cache; 21 static struct kmem_cache *extent_state_cache; 22 static struct kmem_cache *extent_buffer_cache; 23 24 static LIST_HEAD(buffers); 25 static LIST_HEAD(states); 26 27 static spinlock_t state_lock = SPIN_LOCK_UNLOCKED; 28 #define BUFFER_LRU_MAX 64 29 30 struct tree_entry { 31 u64 start; 32 u64 end; 33 int in_tree; 34 struct rb_node rb_node; 35 }; 36 37 void __init extent_map_init(void) 38 { 39 extent_map_cache = btrfs_cache_create("extent_map", 40 sizeof(struct extent_map), 0, 41 NULL); 42 extent_state_cache = btrfs_cache_create("extent_state", 43 sizeof(struct extent_state), 0, 44 NULL); 45 extent_buffer_cache = btrfs_cache_create("extent_buffers", 46 sizeof(struct extent_buffer), 0, 47 NULL); 48 } 49 50 void __exit extent_map_exit(void) 51 { 52 struct extent_state *state; 53 54 while (!list_empty(&states)) { 55 state = list_entry(states.next, struct extent_state, list); 56 printk("state leak: start %Lu end %Lu state %lu in tree %d refs %d\n", state->start, state->end, state->state, state->in_tree, atomic_read(&state->refs)); 57 list_del(&state->list); 58 kmem_cache_free(extent_state_cache, state); 59 60 } 61 62 if (extent_map_cache) 63 kmem_cache_destroy(extent_map_cache); 64 if (extent_state_cache) 65 kmem_cache_destroy(extent_state_cache); 66 if (extent_buffer_cache) 67 kmem_cache_destroy(extent_buffer_cache); 68 } 69 70 void extent_map_tree_init(struct extent_map_tree *tree, 71 struct address_space *mapping, gfp_t mask) 72 { 73 tree->map.rb_node = NULL; 74 tree->state.rb_node = NULL; 75 tree->ops = NULL; 76 rwlock_init(&tree->lock); 77 spin_lock_init(&tree->lru_lock); 78 tree->mapping = mapping; 79 INIT_LIST_HEAD(&tree->buffer_lru); 80 tree->lru_size = 0; 81 } 82 EXPORT_SYMBOL(extent_map_tree_init); 83 84 void extent_map_tree_empty_lru(struct extent_map_tree *tree) 85 { 86 struct extent_buffer *eb; 87 while(!list_empty(&tree->buffer_lru)) { 88 eb = list_entry(tree->buffer_lru.next, struct extent_buffer, 89 lru); 90 list_del(&eb->lru); 91 free_extent_buffer(eb); 92 } 93 } 94 EXPORT_SYMBOL(extent_map_tree_empty_lru); 95 96 struct extent_map *alloc_extent_map(gfp_t mask) 97 { 98 struct extent_map *em; 99 em = kmem_cache_alloc(extent_map_cache, mask); 100 if (!em || IS_ERR(em)) 101 return em; 102 em->in_tree = 0; 103 atomic_set(&em->refs, 1); 104 return em; 105 } 106 EXPORT_SYMBOL(alloc_extent_map); 107 108 void free_extent_map(struct extent_map *em) 109 { 110 if (!em) 111 return; 112 if (atomic_dec_and_test(&em->refs)) { 113 WARN_ON(em->in_tree); 114 kmem_cache_free(extent_map_cache, em); 115 } 116 } 117 EXPORT_SYMBOL(free_extent_map); 118 119 120 struct extent_state *alloc_extent_state(gfp_t mask) 121 { 122 struct extent_state *state; 123 unsigned long flags; 124 125 state = kmem_cache_alloc(extent_state_cache, mask); 126 if (!state || IS_ERR(state)) 127 return state; 128 state->state = 0; 129 state->in_tree = 0; 130 state->private = 0; 131 132 spin_lock_irqsave(&state_lock, flags); 133 list_add(&state->list, &states); 134 spin_unlock_irqrestore(&state_lock, flags); 135 136 atomic_set(&state->refs, 1); 137 init_waitqueue_head(&state->wq); 138 return state; 139 } 140 EXPORT_SYMBOL(alloc_extent_state); 141 142 void free_extent_state(struct extent_state *state) 143 { 144 unsigned long flags; 145 if (!state) 146 return; 147 if (atomic_dec_and_test(&state->refs)) { 148 WARN_ON(state->in_tree); 149 spin_lock_irqsave(&state_lock, flags); 150 list_del(&state->list); 151 spin_unlock_irqrestore(&state_lock, flags); 152 kmem_cache_free(extent_state_cache, state); 153 } 154 } 155 EXPORT_SYMBOL(free_extent_state); 156 157 static struct rb_node *tree_insert(struct rb_root *root, u64 offset, 158 struct rb_node *node) 159 { 160 struct rb_node ** p = &root->rb_node; 161 struct rb_node * parent = NULL; 162 struct tree_entry *entry; 163 164 while(*p) { 165 parent = *p; 166 entry = rb_entry(parent, struct tree_entry, rb_node); 167 168 if (offset < entry->start) 169 p = &(*p)->rb_left; 170 else if (offset > entry->end) 171 p = &(*p)->rb_right; 172 else 173 return parent; 174 } 175 176 entry = rb_entry(node, struct tree_entry, rb_node); 177 entry->in_tree = 1; 178 rb_link_node(node, parent, p); 179 rb_insert_color(node, root); 180 return NULL; 181 } 182 183 static struct rb_node *__tree_search(struct rb_root *root, u64 offset, 184 struct rb_node **prev_ret) 185 { 186 struct rb_node * n = root->rb_node; 187 struct rb_node *prev = NULL; 188 struct tree_entry *entry; 189 struct tree_entry *prev_entry = NULL; 190 191 while(n) { 192 entry = rb_entry(n, struct tree_entry, rb_node); 193 prev = n; 194 prev_entry = entry; 195 196 if (offset < entry->start) 197 n = n->rb_left; 198 else if (offset > entry->end) 199 n = n->rb_right; 200 else 201 return n; 202 } 203 if (!prev_ret) 204 return NULL; 205 while(prev && offset > prev_entry->end) { 206 prev = rb_next(prev); 207 prev_entry = rb_entry(prev, struct tree_entry, rb_node); 208 } 209 *prev_ret = prev; 210 return NULL; 211 } 212 213 static inline struct rb_node *tree_search(struct rb_root *root, u64 offset) 214 { 215 struct rb_node *prev; 216 struct rb_node *ret; 217 ret = __tree_search(root, offset, &prev); 218 if (!ret) 219 return prev; 220 return ret; 221 } 222 223 static int tree_delete(struct rb_root *root, u64 offset) 224 { 225 struct rb_node *node; 226 struct tree_entry *entry; 227 228 node = __tree_search(root, offset, NULL); 229 if (!node) 230 return -ENOENT; 231 entry = rb_entry(node, struct tree_entry, rb_node); 232 entry->in_tree = 0; 233 rb_erase(node, root); 234 return 0; 235 } 236 237 /* 238 * add_extent_mapping tries a simple backward merge with existing 239 * mappings. The extent_map struct passed in will be inserted into 240 * the tree directly (no copies made, just a reference taken). 241 */ 242 int add_extent_mapping(struct extent_map_tree *tree, 243 struct extent_map *em) 244 { 245 int ret = 0; 246 struct extent_map *prev = NULL; 247 struct rb_node *rb; 248 249 write_lock_irq(&tree->lock); 250 rb = tree_insert(&tree->map, em->end, &em->rb_node); 251 if (rb) { 252 prev = rb_entry(rb, struct extent_map, rb_node); 253 printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev->start, prev->end, em->start, em->end); 254 ret = -EEXIST; 255 goto out; 256 } 257 atomic_inc(&em->refs); 258 if (em->start != 0) { 259 rb = rb_prev(&em->rb_node); 260 if (rb) 261 prev = rb_entry(rb, struct extent_map, rb_node); 262 if (prev && prev->end + 1 == em->start && 263 ((em->block_start == EXTENT_MAP_HOLE && 264 prev->block_start == EXTENT_MAP_HOLE) || 265 (em->block_start == prev->block_end + 1))) { 266 em->start = prev->start; 267 em->block_start = prev->block_start; 268 rb_erase(&prev->rb_node, &tree->map); 269 prev->in_tree = 0; 270 free_extent_map(prev); 271 } 272 } 273 out: 274 write_unlock_irq(&tree->lock); 275 return ret; 276 } 277 EXPORT_SYMBOL(add_extent_mapping); 278 279 /* 280 * lookup_extent_mapping returns the first extent_map struct in the 281 * tree that intersects the [start, end] (inclusive) range. There may 282 * be additional objects in the tree that intersect, so check the object 283 * returned carefully to make sure you don't need additional lookups. 284 */ 285 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, 286 u64 start, u64 end) 287 { 288 struct extent_map *em; 289 struct rb_node *rb_node; 290 291 read_lock_irq(&tree->lock); 292 rb_node = tree_search(&tree->map, start); 293 if (!rb_node) { 294 em = NULL; 295 goto out; 296 } 297 if (IS_ERR(rb_node)) { 298 em = ERR_PTR(PTR_ERR(rb_node)); 299 goto out; 300 } 301 em = rb_entry(rb_node, struct extent_map, rb_node); 302 if (em->end < start || em->start > end) { 303 em = NULL; 304 goto out; 305 } 306 atomic_inc(&em->refs); 307 out: 308 read_unlock_irq(&tree->lock); 309 return em; 310 } 311 EXPORT_SYMBOL(lookup_extent_mapping); 312 313 /* 314 * removes an extent_map struct from the tree. No reference counts are 315 * dropped, and no checks are done to see if the range is in use 316 */ 317 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) 318 { 319 int ret; 320 321 write_lock_irq(&tree->lock); 322 ret = tree_delete(&tree->map, em->end); 323 write_unlock_irq(&tree->lock); 324 return ret; 325 } 326 EXPORT_SYMBOL(remove_extent_mapping); 327 328 /* 329 * utility function to look for merge candidates inside a given range. 330 * Any extents with matching state are merged together into a single 331 * extent in the tree. Extents with EXTENT_IO in their state field 332 * are not merged because the end_io handlers need to be able to do 333 * operations on them without sleeping (or doing allocations/splits). 334 * 335 * This should be called with the tree lock held. 336 */ 337 static int merge_state(struct extent_map_tree *tree, 338 struct extent_state *state) 339 { 340 struct extent_state *other; 341 struct rb_node *other_node; 342 343 if (state->state & EXTENT_IOBITS) 344 return 0; 345 346 other_node = rb_prev(&state->rb_node); 347 if (other_node) { 348 other = rb_entry(other_node, struct extent_state, rb_node); 349 if (other->end == state->start - 1 && 350 other->state == state->state) { 351 state->start = other->start; 352 other->in_tree = 0; 353 rb_erase(&other->rb_node, &tree->state); 354 free_extent_state(other); 355 } 356 } 357 other_node = rb_next(&state->rb_node); 358 if (other_node) { 359 other = rb_entry(other_node, struct extent_state, rb_node); 360 if (other->start == state->end + 1 && 361 other->state == state->state) { 362 other->start = state->start; 363 state->in_tree = 0; 364 rb_erase(&state->rb_node, &tree->state); 365 free_extent_state(state); 366 } 367 } 368 return 0; 369 } 370 371 /* 372 * insert an extent_state struct into the tree. 'bits' are set on the 373 * struct before it is inserted. 374 * 375 * This may return -EEXIST if the extent is already there, in which case the 376 * state struct is freed. 377 * 378 * The tree lock is not taken internally. This is a utility function and 379 * probably isn't what you want to call (see set/clear_extent_bit). 380 */ 381 static int insert_state(struct extent_map_tree *tree, 382 struct extent_state *state, u64 start, u64 end, 383 int bits) 384 { 385 struct rb_node *node; 386 387 if (end < start) { 388 printk("end < start %Lu %Lu\n", end, start); 389 WARN_ON(1); 390 } 391 state->state |= bits; 392 state->start = start; 393 state->end = end; 394 node = tree_insert(&tree->state, end, &state->rb_node); 395 if (node) { 396 struct extent_state *found; 397 found = rb_entry(node, struct extent_state, rb_node); 398 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end); 399 free_extent_state(state); 400 return -EEXIST; 401 } 402 merge_state(tree, state); 403 return 0; 404 } 405 406 /* 407 * split a given extent state struct in two, inserting the preallocated 408 * struct 'prealloc' as the newly created second half. 'split' indicates an 409 * offset inside 'orig' where it should be split. 410 * 411 * Before calling, 412 * the tree has 'orig' at [orig->start, orig->end]. After calling, there 413 * are two extent state structs in the tree: 414 * prealloc: [orig->start, split - 1] 415 * orig: [ split, orig->end ] 416 * 417 * The tree locks are not taken by this function. They need to be held 418 * by the caller. 419 */ 420 static int split_state(struct extent_map_tree *tree, struct extent_state *orig, 421 struct extent_state *prealloc, u64 split) 422 { 423 struct rb_node *node; 424 prealloc->start = orig->start; 425 prealloc->end = split - 1; 426 prealloc->state = orig->state; 427 orig->start = split; 428 429 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node); 430 if (node) { 431 struct extent_state *found; 432 found = rb_entry(node, struct extent_state, rb_node); 433 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end); 434 free_extent_state(prealloc); 435 return -EEXIST; 436 } 437 return 0; 438 } 439 440 /* 441 * utility function to clear some bits in an extent state struct. 442 * it will optionally wake up any one waiting on this state (wake == 1), or 443 * forcibly remove the state from the tree (delete == 1). 444 * 445 * If no bits are set on the state struct after clearing things, the 446 * struct is freed and removed from the tree 447 */ 448 static int clear_state_bit(struct extent_map_tree *tree, 449 struct extent_state *state, int bits, int wake, 450 int delete) 451 { 452 int ret = state->state & bits; 453 state->state &= ~bits; 454 if (wake) 455 wake_up(&state->wq); 456 if (delete || state->state == 0) { 457 if (state->in_tree) { 458 rb_erase(&state->rb_node, &tree->state); 459 state->in_tree = 0; 460 free_extent_state(state); 461 } else { 462 WARN_ON(1); 463 } 464 } else { 465 merge_state(tree, state); 466 } 467 return ret; 468 } 469 470 /* 471 * clear some bits on a range in the tree. This may require splitting 472 * or inserting elements in the tree, so the gfp mask is used to 473 * indicate which allocations or sleeping are allowed. 474 * 475 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove 476 * the given range from the tree regardless of state (ie for truncate). 477 * 478 * the range [start, end] is inclusive. 479 * 480 * This takes the tree lock, and returns < 0 on error, > 0 if any of the 481 * bits were already set, or zero if none of the bits were already set. 482 */ 483 int clear_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, 484 int bits, int wake, int delete, gfp_t mask) 485 { 486 struct extent_state *state; 487 struct extent_state *prealloc = NULL; 488 struct rb_node *node; 489 unsigned long flags; 490 int err; 491 int set = 0; 492 493 again: 494 if (!prealloc && (mask & __GFP_WAIT)) { 495 prealloc = alloc_extent_state(mask); 496 if (!prealloc) 497 return -ENOMEM; 498 } 499 500 write_lock_irqsave(&tree->lock, flags); 501 /* 502 * this search will find the extents that end after 503 * our range starts 504 */ 505 node = tree_search(&tree->state, start); 506 if (!node) 507 goto out; 508 state = rb_entry(node, struct extent_state, rb_node); 509 if (state->start > end) 510 goto out; 511 WARN_ON(state->end < start); 512 513 /* 514 * | ---- desired range ---- | 515 * | state | or 516 * | ------------- state -------------- | 517 * 518 * We need to split the extent we found, and may flip 519 * bits on second half. 520 * 521 * If the extent we found extends past our range, we 522 * just split and search again. It'll get split again 523 * the next time though. 524 * 525 * If the extent we found is inside our range, we clear 526 * the desired bit on it. 527 */ 528 529 if (state->start < start) { 530 err = split_state(tree, state, prealloc, start); 531 BUG_ON(err == -EEXIST); 532 prealloc = NULL; 533 if (err) 534 goto out; 535 if (state->end <= end) { 536 start = state->end + 1; 537 set |= clear_state_bit(tree, state, bits, 538 wake, delete); 539 } else { 540 start = state->start; 541 } 542 goto search_again; 543 } 544 /* 545 * | ---- desired range ---- | 546 * | state | 547 * We need to split the extent, and clear the bit 548 * on the first half 549 */ 550 if (state->start <= end && state->end > end) { 551 err = split_state(tree, state, prealloc, end + 1); 552 BUG_ON(err == -EEXIST); 553 554 if (wake) 555 wake_up(&state->wq); 556 set |= clear_state_bit(tree, prealloc, bits, 557 wake, delete); 558 prealloc = NULL; 559 goto out; 560 } 561 562 start = state->end + 1; 563 set |= clear_state_bit(tree, state, bits, wake, delete); 564 goto search_again; 565 566 out: 567 write_unlock_irqrestore(&tree->lock, flags); 568 if (prealloc) 569 free_extent_state(prealloc); 570 571 return set; 572 573 search_again: 574 if (start > end) 575 goto out; 576 write_unlock_irqrestore(&tree->lock, flags); 577 if (mask & __GFP_WAIT) 578 cond_resched(); 579 goto again; 580 } 581 EXPORT_SYMBOL(clear_extent_bit); 582 583 static int wait_on_state(struct extent_map_tree *tree, 584 struct extent_state *state) 585 { 586 DEFINE_WAIT(wait); 587 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); 588 read_unlock_irq(&tree->lock); 589 schedule(); 590 read_lock_irq(&tree->lock); 591 finish_wait(&state->wq, &wait); 592 return 0; 593 } 594 595 /* 596 * waits for one or more bits to clear on a range in the state tree. 597 * The range [start, end] is inclusive. 598 * The tree lock is taken by this function 599 */ 600 int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits) 601 { 602 struct extent_state *state; 603 struct rb_node *node; 604 605 read_lock_irq(&tree->lock); 606 again: 607 while (1) { 608 /* 609 * this search will find all the extents that end after 610 * our range starts 611 */ 612 node = tree_search(&tree->state, start); 613 if (!node) 614 break; 615 616 state = rb_entry(node, struct extent_state, rb_node); 617 618 if (state->start > end) 619 goto out; 620 621 if (state->state & bits) { 622 start = state->start; 623 atomic_inc(&state->refs); 624 wait_on_state(tree, state); 625 free_extent_state(state); 626 goto again; 627 } 628 start = state->end + 1; 629 630 if (start > end) 631 break; 632 633 if (need_resched()) { 634 read_unlock_irq(&tree->lock); 635 cond_resched(); 636 read_lock_irq(&tree->lock); 637 } 638 } 639 out: 640 read_unlock_irq(&tree->lock); 641 return 0; 642 } 643 EXPORT_SYMBOL(wait_extent_bit); 644 645 /* 646 * set some bits on a range in the tree. This may require allocations 647 * or sleeping, so the gfp mask is used to indicate what is allowed. 648 * 649 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the 650 * range already has the desired bits set. The start of the existing 651 * range is returned in failed_start in this case. 652 * 653 * [start, end] is inclusive 654 * This takes the tree lock. 655 */ 656 int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, 657 int exclusive, u64 *failed_start, gfp_t mask) 658 { 659 struct extent_state *state; 660 struct extent_state *prealloc = NULL; 661 struct rb_node *node; 662 unsigned long flags; 663 int err = 0; 664 int set; 665 u64 last_start; 666 u64 last_end; 667 again: 668 if (!prealloc && (mask & __GFP_WAIT)) { 669 prealloc = alloc_extent_state(mask); 670 if (!prealloc) 671 return -ENOMEM; 672 } 673 674 write_lock_irqsave(&tree->lock, flags); 675 /* 676 * this search will find all the extents that end after 677 * our range starts. 678 */ 679 node = tree_search(&tree->state, start); 680 if (!node) { 681 err = insert_state(tree, prealloc, start, end, bits); 682 prealloc = NULL; 683 BUG_ON(err == -EEXIST); 684 goto out; 685 } 686 687 state = rb_entry(node, struct extent_state, rb_node); 688 last_start = state->start; 689 last_end = state->end; 690 691 /* 692 * | ---- desired range ---- | 693 * | state | 694 * 695 * Just lock what we found and keep going 696 */ 697 if (state->start == start && state->end <= end) { 698 set = state->state & bits; 699 if (set && exclusive) { 700 *failed_start = state->start; 701 err = -EEXIST; 702 goto out; 703 } 704 state->state |= bits; 705 start = state->end + 1; 706 merge_state(tree, state); 707 goto search_again; 708 } 709 710 /* 711 * | ---- desired range ---- | 712 * | state | 713 * or 714 * | ------------- state -------------- | 715 * 716 * We need to split the extent we found, and may flip bits on 717 * second half. 718 * 719 * If the extent we found extends past our 720 * range, we just split and search again. It'll get split 721 * again the next time though. 722 * 723 * If the extent we found is inside our range, we set the 724 * desired bit on it. 725 */ 726 if (state->start < start) { 727 set = state->state & bits; 728 if (exclusive && set) { 729 *failed_start = start; 730 err = -EEXIST; 731 goto out; 732 } 733 err = split_state(tree, state, prealloc, start); 734 BUG_ON(err == -EEXIST); 735 prealloc = NULL; 736 if (err) 737 goto out; 738 if (state->end <= end) { 739 state->state |= bits; 740 start = state->end + 1; 741 merge_state(tree, state); 742 } else { 743 start = state->start; 744 } 745 goto search_again; 746 } 747 /* 748 * | ---- desired range ---- | 749 * | state | or | state | 750 * 751 * There's a hole, we need to insert something in it and 752 * ignore the extent we found. 753 */ 754 if (state->start > start) { 755 u64 this_end; 756 if (end < last_start) 757 this_end = end; 758 else 759 this_end = last_start -1; 760 err = insert_state(tree, prealloc, start, this_end, 761 bits); 762 prealloc = NULL; 763 BUG_ON(err == -EEXIST); 764 if (err) 765 goto out; 766 start = this_end + 1; 767 goto search_again; 768 } 769 /* 770 * | ---- desired range ---- | 771 * | state | 772 * We need to split the extent, and set the bit 773 * on the first half 774 */ 775 if (state->start <= end && state->end > end) { 776 set = state->state & bits; 777 if (exclusive && set) { 778 *failed_start = start; 779 err = -EEXIST; 780 goto out; 781 } 782 err = split_state(tree, state, prealloc, end + 1); 783 BUG_ON(err == -EEXIST); 784 785 prealloc->state |= bits; 786 merge_state(tree, prealloc); 787 prealloc = NULL; 788 goto out; 789 } 790 791 goto search_again; 792 793 out: 794 write_unlock_irqrestore(&tree->lock, flags); 795 if (prealloc) 796 free_extent_state(prealloc); 797 798 return err; 799 800 search_again: 801 if (start > end) 802 goto out; 803 write_unlock_irqrestore(&tree->lock, flags); 804 if (mask & __GFP_WAIT) 805 cond_resched(); 806 goto again; 807 } 808 EXPORT_SYMBOL(set_extent_bit); 809 810 /* wrappers around set/clear extent bit */ 811 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 812 gfp_t mask) 813 { 814 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, 815 mask); 816 } 817 EXPORT_SYMBOL(set_extent_dirty); 818 819 int set_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 820 int bits, gfp_t mask) 821 { 822 return set_extent_bit(tree, start, end, bits, 0, NULL, 823 mask); 824 } 825 EXPORT_SYMBOL(set_extent_bits); 826 827 int clear_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 828 int bits, gfp_t mask) 829 { 830 return clear_extent_bit(tree, start, end, bits, 0, 0, mask); 831 } 832 EXPORT_SYMBOL(clear_extent_bits); 833 834 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end, 835 gfp_t mask) 836 { 837 return set_extent_bit(tree, start, end, 838 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL, 839 mask); 840 } 841 EXPORT_SYMBOL(set_extent_delalloc); 842 843 int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 844 gfp_t mask) 845 { 846 return clear_extent_bit(tree, start, end, 847 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask); 848 } 849 EXPORT_SYMBOL(clear_extent_dirty); 850 851 int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 852 gfp_t mask) 853 { 854 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, 855 mask); 856 } 857 EXPORT_SYMBOL(set_extent_new); 858 859 int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 860 gfp_t mask) 861 { 862 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask); 863 } 864 EXPORT_SYMBOL(clear_extent_new); 865 866 int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 867 gfp_t mask) 868 { 869 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL, 870 mask); 871 } 872 EXPORT_SYMBOL(set_extent_uptodate); 873 874 int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 875 gfp_t mask) 876 { 877 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask); 878 } 879 EXPORT_SYMBOL(clear_extent_uptodate); 880 881 int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 882 gfp_t mask) 883 { 884 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK, 885 0, NULL, mask); 886 } 887 EXPORT_SYMBOL(set_extent_writeback); 888 889 int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 890 gfp_t mask) 891 { 892 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask); 893 } 894 EXPORT_SYMBOL(clear_extent_writeback); 895 896 int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end) 897 { 898 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK); 899 } 900 EXPORT_SYMBOL(wait_on_extent_writeback); 901 902 /* 903 * locks a range in ascending order, waiting for any locked regions 904 * it hits on the way. [start,end] are inclusive, and this will sleep. 905 */ 906 int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask) 907 { 908 int err; 909 u64 failed_start; 910 while (1) { 911 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 912 &failed_start, mask); 913 if (err == -EEXIST && (mask & __GFP_WAIT)) { 914 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); 915 start = failed_start; 916 } else { 917 break; 918 } 919 WARN_ON(start > end); 920 } 921 return err; 922 } 923 EXPORT_SYMBOL(lock_extent); 924 925 int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, 926 gfp_t mask) 927 { 928 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask); 929 } 930 EXPORT_SYMBOL(unlock_extent); 931 932 /* 933 * helper function to set pages and extents in the tree dirty 934 */ 935 int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end) 936 { 937 unsigned long index = start >> PAGE_CACHE_SHIFT; 938 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 939 struct page *page; 940 941 while (index <= end_index) { 942 page = find_get_page(tree->mapping, index); 943 BUG_ON(!page); 944 __set_page_dirty_nobuffers(page); 945 page_cache_release(page); 946 index++; 947 } 948 set_extent_dirty(tree, start, end, GFP_NOFS); 949 return 0; 950 } 951 EXPORT_SYMBOL(set_range_dirty); 952 953 /* 954 * helper function to set both pages and extents in the tree writeback 955 */ 956 int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end) 957 { 958 unsigned long index = start >> PAGE_CACHE_SHIFT; 959 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 960 struct page *page; 961 962 while (index <= end_index) { 963 page = find_get_page(tree->mapping, index); 964 BUG_ON(!page); 965 set_page_writeback(page); 966 page_cache_release(page); 967 index++; 968 } 969 set_extent_writeback(tree, start, end, GFP_NOFS); 970 return 0; 971 } 972 EXPORT_SYMBOL(set_range_writeback); 973 974 int find_first_extent_bit(struct extent_map_tree *tree, u64 start, 975 u64 *start_ret, u64 *end_ret, int bits) 976 { 977 struct rb_node *node; 978 struct extent_state *state; 979 int ret = 1; 980 981 read_lock_irq(&tree->lock); 982 /* 983 * this search will find all the extents that end after 984 * our range starts. 985 */ 986 node = tree_search(&tree->state, start); 987 if (!node || IS_ERR(node)) { 988 goto out; 989 } 990 991 while(1) { 992 state = rb_entry(node, struct extent_state, rb_node); 993 if (state->end >= start && (state->state & bits)) { 994 *start_ret = state->start; 995 *end_ret = state->end; 996 ret = 0; 997 break; 998 } 999 node = rb_next(node); 1000 if (!node) 1001 break; 1002 } 1003 out: 1004 read_unlock_irq(&tree->lock); 1005 return ret; 1006 } 1007 EXPORT_SYMBOL(find_first_extent_bit); 1008 1009 u64 find_lock_delalloc_range(struct extent_map_tree *tree, 1010 u64 start, u64 lock_start, u64 *end, u64 max_bytes) 1011 { 1012 struct rb_node *node; 1013 struct extent_state *state; 1014 u64 cur_start = start; 1015 u64 found = 0; 1016 u64 total_bytes = 0; 1017 1018 write_lock_irq(&tree->lock); 1019 /* 1020 * this search will find all the extents that end after 1021 * our range starts. 1022 */ 1023 search_again: 1024 node = tree_search(&tree->state, cur_start); 1025 if (!node || IS_ERR(node)) { 1026 goto out; 1027 } 1028 1029 while(1) { 1030 state = rb_entry(node, struct extent_state, rb_node); 1031 if (state->start != cur_start) { 1032 goto out; 1033 } 1034 if (!(state->state & EXTENT_DELALLOC)) { 1035 goto out; 1036 } 1037 if (state->start >= lock_start) { 1038 if (state->state & EXTENT_LOCKED) { 1039 DEFINE_WAIT(wait); 1040 atomic_inc(&state->refs); 1041 write_unlock_irq(&tree->lock); 1042 schedule(); 1043 write_lock_irq(&tree->lock); 1044 finish_wait(&state->wq, &wait); 1045 free_extent_state(state); 1046 goto search_again; 1047 } 1048 state->state |= EXTENT_LOCKED; 1049 } 1050 found++; 1051 *end = state->end; 1052 cur_start = state->end + 1; 1053 node = rb_next(node); 1054 if (!node) 1055 break; 1056 total_bytes = state->end - state->start + 1; 1057 if (total_bytes >= max_bytes) 1058 break; 1059 } 1060 out: 1061 write_unlock_irq(&tree->lock); 1062 return found; 1063 } 1064 1065 /* 1066 * helper function to lock both pages and extents in the tree. 1067 * pages must be locked first. 1068 */ 1069 int lock_range(struct extent_map_tree *tree, u64 start, u64 end) 1070 { 1071 unsigned long index = start >> PAGE_CACHE_SHIFT; 1072 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1073 struct page *page; 1074 int err; 1075 1076 while (index <= end_index) { 1077 page = grab_cache_page(tree->mapping, index); 1078 if (!page) { 1079 err = -ENOMEM; 1080 goto failed; 1081 } 1082 if (IS_ERR(page)) { 1083 err = PTR_ERR(page); 1084 goto failed; 1085 } 1086 index++; 1087 } 1088 lock_extent(tree, start, end, GFP_NOFS); 1089 return 0; 1090 1091 failed: 1092 /* 1093 * we failed above in getting the page at 'index', so we undo here 1094 * up to but not including the page at 'index' 1095 */ 1096 end_index = index; 1097 index = start >> PAGE_CACHE_SHIFT; 1098 while (index < end_index) { 1099 page = find_get_page(tree->mapping, index); 1100 unlock_page(page); 1101 page_cache_release(page); 1102 index++; 1103 } 1104 return err; 1105 } 1106 EXPORT_SYMBOL(lock_range); 1107 1108 /* 1109 * helper function to unlock both pages and extents in the tree. 1110 */ 1111 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end) 1112 { 1113 unsigned long index = start >> PAGE_CACHE_SHIFT; 1114 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1115 struct page *page; 1116 1117 while (index <= end_index) { 1118 page = find_get_page(tree->mapping, index); 1119 unlock_page(page); 1120 page_cache_release(page); 1121 index++; 1122 } 1123 unlock_extent(tree, start, end, GFP_NOFS); 1124 return 0; 1125 } 1126 EXPORT_SYMBOL(unlock_range); 1127 1128 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private) 1129 { 1130 struct rb_node *node; 1131 struct extent_state *state; 1132 int ret = 0; 1133 1134 write_lock_irq(&tree->lock); 1135 /* 1136 * this search will find all the extents that end after 1137 * our range starts. 1138 */ 1139 node = tree_search(&tree->state, start); 1140 if (!node || IS_ERR(node)) { 1141 ret = -ENOENT; 1142 goto out; 1143 } 1144 state = rb_entry(node, struct extent_state, rb_node); 1145 if (state->start != start) { 1146 ret = -ENOENT; 1147 goto out; 1148 } 1149 state->private = private; 1150 out: 1151 write_unlock_irq(&tree->lock); 1152 return ret; 1153 } 1154 1155 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private) 1156 { 1157 struct rb_node *node; 1158 struct extent_state *state; 1159 int ret = 0; 1160 1161 read_lock_irq(&tree->lock); 1162 /* 1163 * this search will find all the extents that end after 1164 * our range starts. 1165 */ 1166 node = tree_search(&tree->state, start); 1167 if (!node || IS_ERR(node)) { 1168 ret = -ENOENT; 1169 goto out; 1170 } 1171 state = rb_entry(node, struct extent_state, rb_node); 1172 if (state->start != start) { 1173 ret = -ENOENT; 1174 goto out; 1175 } 1176 *private = state->private; 1177 out: 1178 read_unlock_irq(&tree->lock); 1179 return ret; 1180 } 1181 1182 /* 1183 * searches a range in the state tree for a given mask. 1184 * If 'filled' == 1, this returns 1 only if ever extent in the tree 1185 * has the bits set. Otherwise, 1 is returned if any bit in the 1186 * range is found set. 1187 */ 1188 int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end, 1189 int bits, int filled) 1190 { 1191 struct extent_state *state = NULL; 1192 struct rb_node *node; 1193 int bitset = 0; 1194 1195 read_lock_irq(&tree->lock); 1196 node = tree_search(&tree->state, start); 1197 while (node && start <= end) { 1198 state = rb_entry(node, struct extent_state, rb_node); 1199 if (state->start > end) 1200 break; 1201 1202 if (filled && state->start > start) { 1203 bitset = 0; 1204 break; 1205 } 1206 if (state->state & bits) { 1207 bitset = 1; 1208 if (!filled) 1209 break; 1210 } else if (filled) { 1211 bitset = 0; 1212 break; 1213 } 1214 start = state->end + 1; 1215 if (start > end) 1216 break; 1217 node = rb_next(node); 1218 } 1219 read_unlock_irq(&tree->lock); 1220 return bitset; 1221 } 1222 EXPORT_SYMBOL(test_range_bit); 1223 1224 /* 1225 * helper function to set a given page up to date if all the 1226 * extents in the tree for that page are up to date 1227 */ 1228 static int check_page_uptodate(struct extent_map_tree *tree, 1229 struct page *page) 1230 { 1231 u64 start = page->index << PAGE_CACHE_SHIFT; 1232 u64 end = start + PAGE_CACHE_SIZE - 1; 1233 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1)) 1234 SetPageUptodate(page); 1235 return 0; 1236 } 1237 1238 /* 1239 * helper function to unlock a page if all the extents in the tree 1240 * for that page are unlocked 1241 */ 1242 static int check_page_locked(struct extent_map_tree *tree, 1243 struct page *page) 1244 { 1245 u64 start = page->index << PAGE_CACHE_SHIFT; 1246 u64 end = start + PAGE_CACHE_SIZE - 1; 1247 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0)) 1248 unlock_page(page); 1249 return 0; 1250 } 1251 1252 /* 1253 * helper function to end page writeback if all the extents 1254 * in the tree for that page are done with writeback 1255 */ 1256 static int check_page_writeback(struct extent_map_tree *tree, 1257 struct page *page) 1258 { 1259 u64 start = page->index << PAGE_CACHE_SHIFT; 1260 u64 end = start + PAGE_CACHE_SIZE - 1; 1261 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0)) 1262 end_page_writeback(page); 1263 return 0; 1264 } 1265 1266 /* lots and lots of room for performance fixes in the end_bio funcs */ 1267 1268 /* 1269 * after a writepage IO is done, we need to: 1270 * clear the uptodate bits on error 1271 * clear the writeback bits in the extent tree for this IO 1272 * end_page_writeback if the page has no more pending IO 1273 * 1274 * Scheduling is not allowed, so the extent state tree is expected 1275 * to have one and only one object corresponding to this IO. 1276 */ 1277 static int end_bio_extent_writepage(struct bio *bio, 1278 unsigned int bytes_done, int err) 1279 { 1280 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1281 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1282 struct extent_map_tree *tree = bio->bi_private; 1283 u64 start; 1284 u64 end; 1285 int whole_page; 1286 1287 if (bio->bi_size) 1288 return 1; 1289 1290 do { 1291 struct page *page = bvec->bv_page; 1292 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset; 1293 end = start + bvec->bv_len - 1; 1294 1295 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1296 whole_page = 1; 1297 else 1298 whole_page = 0; 1299 1300 if (--bvec >= bio->bi_io_vec) 1301 prefetchw(&bvec->bv_page->flags); 1302 1303 if (!uptodate) { 1304 clear_extent_uptodate(tree, start, end, GFP_ATOMIC); 1305 ClearPageUptodate(page); 1306 SetPageError(page); 1307 } 1308 clear_extent_writeback(tree, start, end, GFP_ATOMIC); 1309 1310 if (whole_page) 1311 end_page_writeback(page); 1312 else 1313 check_page_writeback(tree, page); 1314 if (tree->ops && tree->ops->writepage_end_io_hook) 1315 tree->ops->writepage_end_io_hook(page, start, end); 1316 } while (bvec >= bio->bi_io_vec); 1317 1318 bio_put(bio); 1319 return 0; 1320 } 1321 1322 /* 1323 * after a readpage IO is done, we need to: 1324 * clear the uptodate bits on error 1325 * set the uptodate bits if things worked 1326 * set the page up to date if all extents in the tree are uptodate 1327 * clear the lock bit in the extent tree 1328 * unlock the page if there are no other extents locked for it 1329 * 1330 * Scheduling is not allowed, so the extent state tree is expected 1331 * to have one and only one object corresponding to this IO. 1332 */ 1333 static int end_bio_extent_readpage(struct bio *bio, 1334 unsigned int bytes_done, int err) 1335 { 1336 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1337 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1338 struct extent_map_tree *tree = bio->bi_private; 1339 u64 start; 1340 u64 end; 1341 int whole_page; 1342 int ret; 1343 1344 if (bio->bi_size) 1345 return 1; 1346 1347 do { 1348 struct page *page = bvec->bv_page; 1349 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset; 1350 end = start + bvec->bv_len - 1; 1351 1352 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1353 whole_page = 1; 1354 else 1355 whole_page = 0; 1356 1357 if (--bvec >= bio->bi_io_vec) 1358 prefetchw(&bvec->bv_page->flags); 1359 1360 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { 1361 ret = tree->ops->readpage_end_io_hook(page, start, end); 1362 if (ret) 1363 uptodate = 0; 1364 } 1365 if (uptodate) { 1366 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1367 if (whole_page) 1368 SetPageUptodate(page); 1369 else 1370 check_page_uptodate(tree, page); 1371 } else { 1372 ClearPageUptodate(page); 1373 SetPageError(page); 1374 } 1375 1376 unlock_extent(tree, start, end, GFP_ATOMIC); 1377 1378 if (whole_page) 1379 unlock_page(page); 1380 else 1381 check_page_locked(tree, page); 1382 } while (bvec >= bio->bi_io_vec); 1383 1384 bio_put(bio); 1385 return 0; 1386 } 1387 1388 /* 1389 * IO done from prepare_write is pretty simple, we just unlock 1390 * the structs in the extent tree when done, and set the uptodate bits 1391 * as appropriate. 1392 */ 1393 static int end_bio_extent_preparewrite(struct bio *bio, 1394 unsigned int bytes_done, int err) 1395 { 1396 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1397 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1398 struct extent_map_tree *tree = bio->bi_private; 1399 u64 start; 1400 u64 end; 1401 1402 if (bio->bi_size) 1403 return 1; 1404 1405 do { 1406 struct page *page = bvec->bv_page; 1407 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset; 1408 end = start + bvec->bv_len - 1; 1409 1410 if (--bvec >= bio->bi_io_vec) 1411 prefetchw(&bvec->bv_page->flags); 1412 1413 if (uptodate) { 1414 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1415 } else { 1416 ClearPageUptodate(page); 1417 SetPageError(page); 1418 } 1419 1420 unlock_extent(tree, start, end, GFP_ATOMIC); 1421 1422 } while (bvec >= bio->bi_io_vec); 1423 1424 bio_put(bio); 1425 return 0; 1426 } 1427 1428 static int submit_extent_page(int rw, struct extent_map_tree *tree, 1429 struct page *page, sector_t sector, 1430 size_t size, unsigned long offset, 1431 struct block_device *bdev, 1432 bio_end_io_t end_io_func) 1433 { 1434 struct bio *bio; 1435 int ret = 0; 1436 1437 bio = bio_alloc(GFP_NOIO, 1); 1438 1439 bio->bi_sector = sector; 1440 bio->bi_bdev = bdev; 1441 bio->bi_io_vec[0].bv_page = page; 1442 bio->bi_io_vec[0].bv_len = size; 1443 bio->bi_io_vec[0].bv_offset = offset; 1444 1445 bio->bi_vcnt = 1; 1446 bio->bi_idx = 0; 1447 bio->bi_size = size; 1448 1449 bio->bi_end_io = end_io_func; 1450 bio->bi_private = tree; 1451 1452 bio_get(bio); 1453 submit_bio(rw, bio); 1454 1455 if (bio_flagged(bio, BIO_EOPNOTSUPP)) 1456 ret = -EOPNOTSUPP; 1457 1458 bio_put(bio); 1459 return ret; 1460 } 1461 1462 void set_page_extent_mapped(struct page *page) 1463 { 1464 if (!PagePrivate(page)) { 1465 SetPagePrivate(page); 1466 WARN_ON(!page->mapping->a_ops->invalidatepage); 1467 set_page_private(page, EXTENT_PAGE_PRIVATE); 1468 page_cache_get(page); 1469 } 1470 } 1471 1472 /* 1473 * basic readpage implementation. Locked extent state structs are inserted 1474 * into the tree that are removed when the IO is done (by the end_io 1475 * handlers) 1476 */ 1477 int extent_read_full_page(struct extent_map_tree *tree, struct page *page, 1478 get_extent_t *get_extent) 1479 { 1480 struct inode *inode = page->mapping->host; 1481 u64 start = page->index << PAGE_CACHE_SHIFT; 1482 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1483 u64 end; 1484 u64 cur = start; 1485 u64 extent_offset; 1486 u64 last_byte = i_size_read(inode); 1487 u64 block_start; 1488 u64 cur_end; 1489 sector_t sector; 1490 struct extent_map *em; 1491 struct block_device *bdev; 1492 int ret; 1493 int nr = 0; 1494 size_t page_offset = 0; 1495 size_t iosize; 1496 size_t blocksize = inode->i_sb->s_blocksize; 1497 1498 set_page_extent_mapped(page); 1499 1500 end = page_end; 1501 lock_extent(tree, start, end, GFP_NOFS); 1502 1503 while (cur <= end) { 1504 if (cur >= last_byte) { 1505 iosize = PAGE_CACHE_SIZE - page_offset; 1506 zero_user_page(page, page_offset, iosize, KM_USER0); 1507 set_extent_uptodate(tree, cur, cur + iosize - 1, 1508 GFP_NOFS); 1509 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1510 break; 1511 } 1512 em = get_extent(inode, page, page_offset, cur, end, 0); 1513 if (IS_ERR(em) || !em) { 1514 SetPageError(page); 1515 unlock_extent(tree, cur, end, GFP_NOFS); 1516 break; 1517 } 1518 1519 extent_offset = cur - em->start; 1520 BUG_ON(em->end < cur); 1521 BUG_ON(end < cur); 1522 1523 iosize = min(em->end - cur, end - cur) + 1; 1524 cur_end = min(em->end, end); 1525 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1526 sector = (em->block_start + extent_offset) >> 9; 1527 bdev = em->bdev; 1528 block_start = em->block_start; 1529 free_extent_map(em); 1530 em = NULL; 1531 1532 /* we've found a hole, just zero and go on */ 1533 if (block_start == EXTENT_MAP_HOLE) { 1534 zero_user_page(page, page_offset, iosize, KM_USER0); 1535 set_extent_uptodate(tree, cur, cur + iosize - 1, 1536 GFP_NOFS); 1537 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1538 cur = cur + iosize; 1539 page_offset += iosize; 1540 continue; 1541 } 1542 /* the get_extent function already copied into the page */ 1543 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { 1544 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1545 cur = cur + iosize; 1546 page_offset += iosize; 1547 continue; 1548 } 1549 1550 ret = 0; 1551 if (tree->ops && tree->ops->readpage_io_hook) { 1552 ret = tree->ops->readpage_io_hook(page, cur, 1553 cur + iosize - 1); 1554 } 1555 if (!ret) { 1556 ret = submit_extent_page(READ, tree, page, 1557 sector, iosize, page_offset, 1558 bdev, end_bio_extent_readpage); 1559 } 1560 if (ret) 1561 SetPageError(page); 1562 cur = cur + iosize; 1563 page_offset += iosize; 1564 nr++; 1565 } 1566 if (!nr) { 1567 if (!PageError(page)) 1568 SetPageUptodate(page); 1569 unlock_page(page); 1570 } 1571 return 0; 1572 } 1573 EXPORT_SYMBOL(extent_read_full_page); 1574 1575 /* 1576 * the writepage semantics are similar to regular writepage. extent 1577 * records are inserted to lock ranges in the tree, and as dirty areas 1578 * are found, they are marked writeback. Then the lock bits are removed 1579 * and the end_io handler clears the writeback ranges 1580 */ 1581 int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 1582 get_extent_t *get_extent, 1583 struct writeback_control *wbc) 1584 { 1585 struct inode *inode = page->mapping->host; 1586 u64 start = page->index << PAGE_CACHE_SHIFT; 1587 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1588 u64 end; 1589 u64 cur = start; 1590 u64 extent_offset; 1591 u64 last_byte = i_size_read(inode); 1592 u64 block_start; 1593 sector_t sector; 1594 struct extent_map *em; 1595 struct block_device *bdev; 1596 int ret; 1597 int nr = 0; 1598 size_t page_offset = 0; 1599 size_t iosize; 1600 size_t blocksize; 1601 loff_t i_size = i_size_read(inode); 1602 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; 1603 u64 nr_delalloc; 1604 u64 delalloc_end; 1605 1606 WARN_ON(!PageLocked(page)); 1607 if (page->index > end_index) { 1608 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1609 unlock_page(page); 1610 return 0; 1611 } 1612 1613 if (page->index == end_index) { 1614 size_t offset = i_size & (PAGE_CACHE_SIZE - 1); 1615 zero_user_page(page, offset, 1616 PAGE_CACHE_SIZE - offset, KM_USER0); 1617 } 1618 1619 set_page_extent_mapped(page); 1620 1621 lock_extent(tree, start, page_end, GFP_NOFS); 1622 nr_delalloc = find_lock_delalloc_range(tree, start, page_end + 1, 1623 &delalloc_end, 1624 128 * 1024 * 1024); 1625 if (nr_delalloc) { 1626 tree->ops->fill_delalloc(inode, start, delalloc_end); 1627 if (delalloc_end >= page_end + 1) { 1628 clear_extent_bit(tree, page_end + 1, delalloc_end, 1629 EXTENT_LOCKED | EXTENT_DELALLOC, 1630 1, 0, GFP_NOFS); 1631 } 1632 clear_extent_bit(tree, start, page_end, EXTENT_DELALLOC, 1633 0, 0, GFP_NOFS); 1634 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1635 printk("found delalloc bits after clear extent_bit\n"); 1636 } 1637 } else if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1638 printk("found delalloc bits after find_delalloc_range returns 0\n"); 1639 } 1640 1641 end = page_end; 1642 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1643 printk("found delalloc bits after lock_extent\n"); 1644 } 1645 1646 if (last_byte <= start) { 1647 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1648 goto done; 1649 } 1650 1651 set_extent_uptodate(tree, start, page_end, GFP_NOFS); 1652 blocksize = inode->i_sb->s_blocksize; 1653 1654 while (cur <= end) { 1655 if (cur >= last_byte) { 1656 clear_extent_dirty(tree, cur, page_end, GFP_NOFS); 1657 break; 1658 } 1659 em = get_extent(inode, page, page_offset, cur, end, 0); 1660 if (IS_ERR(em) || !em) { 1661 SetPageError(page); 1662 break; 1663 } 1664 1665 extent_offset = cur - em->start; 1666 BUG_ON(em->end < cur); 1667 BUG_ON(end < cur); 1668 iosize = min(em->end - cur, end - cur) + 1; 1669 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1670 sector = (em->block_start + extent_offset) >> 9; 1671 bdev = em->bdev; 1672 block_start = em->block_start; 1673 free_extent_map(em); 1674 em = NULL; 1675 1676 if (block_start == EXTENT_MAP_HOLE || 1677 block_start == EXTENT_MAP_INLINE) { 1678 clear_extent_dirty(tree, cur, 1679 cur + iosize - 1, GFP_NOFS); 1680 cur = cur + iosize; 1681 page_offset += iosize; 1682 continue; 1683 } 1684 1685 /* leave this out until we have a page_mkwrite call */ 1686 if (0 && !test_range_bit(tree, cur, cur + iosize - 1, 1687 EXTENT_DIRTY, 0)) { 1688 cur = cur + iosize; 1689 page_offset += iosize; 1690 continue; 1691 } 1692 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); 1693 if (tree->ops && tree->ops->writepage_io_hook) { 1694 ret = tree->ops->writepage_io_hook(page, cur, 1695 cur + iosize - 1); 1696 } else { 1697 ret = 0; 1698 } 1699 if (ret) 1700 SetPageError(page); 1701 else { 1702 set_range_writeback(tree, cur, cur + iosize - 1); 1703 ret = submit_extent_page(WRITE, tree, page, sector, 1704 iosize, page_offset, bdev, 1705 end_bio_extent_writepage); 1706 if (ret) 1707 SetPageError(page); 1708 } 1709 cur = cur + iosize; 1710 page_offset += iosize; 1711 nr++; 1712 } 1713 done: 1714 unlock_extent(tree, start, page_end, GFP_NOFS); 1715 unlock_page(page); 1716 return 0; 1717 } 1718 EXPORT_SYMBOL(extent_write_full_page); 1719 1720 /* 1721 * basic invalidatepage code, this waits on any locked or writeback 1722 * ranges corresponding to the page, and then deletes any extent state 1723 * records from the tree 1724 */ 1725 int extent_invalidatepage(struct extent_map_tree *tree, 1726 struct page *page, unsigned long offset) 1727 { 1728 u64 start = (page->index << PAGE_CACHE_SHIFT); 1729 u64 end = start + PAGE_CACHE_SIZE - 1; 1730 size_t blocksize = page->mapping->host->i_sb->s_blocksize; 1731 1732 start += (offset + blocksize -1) & ~(blocksize - 1); 1733 if (start > end) 1734 return 0; 1735 1736 lock_extent(tree, start, end, GFP_NOFS); 1737 wait_on_extent_writeback(tree, start, end); 1738 clear_extent_bit(tree, start, end, 1739 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, 1740 1, 1, GFP_NOFS); 1741 return 0; 1742 } 1743 EXPORT_SYMBOL(extent_invalidatepage); 1744 1745 /* 1746 * simple commit_write call, set_range_dirty is used to mark both 1747 * the pages and the extent records as dirty 1748 */ 1749 int extent_commit_write(struct extent_map_tree *tree, 1750 struct inode *inode, struct page *page, 1751 unsigned from, unsigned to) 1752 { 1753 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; 1754 1755 set_page_extent_mapped(page); 1756 set_page_dirty(page); 1757 1758 if (pos > inode->i_size) { 1759 i_size_write(inode, pos); 1760 mark_inode_dirty(inode); 1761 } 1762 return 0; 1763 } 1764 EXPORT_SYMBOL(extent_commit_write); 1765 1766 int extent_prepare_write(struct extent_map_tree *tree, 1767 struct inode *inode, struct page *page, 1768 unsigned from, unsigned to, get_extent_t *get_extent) 1769 { 1770 u64 page_start = page->index << PAGE_CACHE_SHIFT; 1771 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 1772 u64 block_start; 1773 u64 orig_block_start; 1774 u64 block_end; 1775 u64 cur_end; 1776 struct extent_map *em; 1777 unsigned blocksize = 1 << inode->i_blkbits; 1778 size_t page_offset = 0; 1779 size_t block_off_start; 1780 size_t block_off_end; 1781 int err = 0; 1782 int iocount = 0; 1783 int ret = 0; 1784 int isnew; 1785 1786 set_page_extent_mapped(page); 1787 1788 block_start = (page_start + from) & ~((u64)blocksize - 1); 1789 block_end = (page_start + to - 1) | (blocksize - 1); 1790 orig_block_start = block_start; 1791 1792 lock_extent(tree, page_start, page_end, GFP_NOFS); 1793 while(block_start <= block_end) { 1794 em = get_extent(inode, page, page_offset, block_start, 1795 block_end, 1); 1796 if (IS_ERR(em) || !em) { 1797 goto err; 1798 } 1799 cur_end = min(block_end, em->end); 1800 block_off_start = block_start & (PAGE_CACHE_SIZE - 1); 1801 block_off_end = block_off_start + blocksize; 1802 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); 1803 1804 if (!PageUptodate(page) && isnew && 1805 (block_off_end > to || block_off_start < from)) { 1806 void *kaddr; 1807 1808 kaddr = kmap_atomic(page, KM_USER0); 1809 if (block_off_end > to) 1810 memset(kaddr + to, 0, block_off_end - to); 1811 if (block_off_start < from) 1812 memset(kaddr + block_off_start, 0, 1813 from - block_off_start); 1814 flush_dcache_page(page); 1815 kunmap_atomic(kaddr, KM_USER0); 1816 } 1817 if (!isnew && !PageUptodate(page) && 1818 (block_off_end > to || block_off_start < from) && 1819 !test_range_bit(tree, block_start, cur_end, 1820 EXTENT_UPTODATE, 1)) { 1821 u64 sector; 1822 u64 extent_offset = block_start - em->start; 1823 size_t iosize; 1824 sector = (em->block_start + extent_offset) >> 9; 1825 iosize = (cur_end - block_start + blocksize - 1) & 1826 ~((u64)blocksize - 1); 1827 /* 1828 * we've already got the extent locked, but we 1829 * need to split the state such that our end_bio 1830 * handler can clear the lock. 1831 */ 1832 set_extent_bit(tree, block_start, 1833 block_start + iosize - 1, 1834 EXTENT_LOCKED, 0, NULL, GFP_NOFS); 1835 ret = submit_extent_page(READ, tree, page, 1836 sector, iosize, page_offset, em->bdev, 1837 end_bio_extent_preparewrite); 1838 iocount++; 1839 block_start = block_start + iosize; 1840 } else { 1841 set_extent_uptodate(tree, block_start, cur_end, 1842 GFP_NOFS); 1843 unlock_extent(tree, block_start, cur_end, GFP_NOFS); 1844 block_start = cur_end + 1; 1845 } 1846 page_offset = block_start & (PAGE_CACHE_SIZE - 1); 1847 free_extent_map(em); 1848 } 1849 if (iocount) { 1850 wait_extent_bit(tree, orig_block_start, 1851 block_end, EXTENT_LOCKED); 1852 } 1853 check_page_uptodate(tree, page); 1854 err: 1855 /* FIXME, zero out newly allocated blocks on error */ 1856 return err; 1857 } 1858 EXPORT_SYMBOL(extent_prepare_write); 1859 1860 /* 1861 * a helper for releasepage. As long as there are no locked extents 1862 * in the range corresponding to the page, both state records and extent 1863 * map records are removed 1864 */ 1865 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) 1866 { 1867 struct extent_map *em; 1868 u64 start = page->index << PAGE_CACHE_SHIFT; 1869 u64 end = start + PAGE_CACHE_SIZE - 1; 1870 u64 orig_start = start; 1871 int ret = 1; 1872 1873 while (start <= end) { 1874 em = lookup_extent_mapping(tree, start, end); 1875 if (!em || IS_ERR(em)) 1876 break; 1877 if (!test_range_bit(tree, em->start, em->end, 1878 EXTENT_LOCKED, 0)) { 1879 remove_extent_mapping(tree, em); 1880 /* once for the rb tree */ 1881 free_extent_map(em); 1882 } 1883 start = em->end + 1; 1884 /* once for us */ 1885 free_extent_map(em); 1886 } 1887 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) 1888 ret = 0; 1889 else 1890 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, 1891 1, 1, GFP_NOFS); 1892 return ret; 1893 } 1894 EXPORT_SYMBOL(try_release_extent_mapping); 1895 1896 sector_t extent_bmap(struct address_space *mapping, sector_t iblock, 1897 get_extent_t *get_extent) 1898 { 1899 struct inode *inode = mapping->host; 1900 u64 start = iblock << inode->i_blkbits; 1901 u64 end = start + (1 << inode->i_blkbits) - 1; 1902 struct extent_map *em; 1903 1904 em = get_extent(inode, NULL, 0, start, end, 0); 1905 if (!em || IS_ERR(em)) 1906 return 0; 1907 1908 if (em->block_start == EXTENT_MAP_INLINE || 1909 em->block_start == EXTENT_MAP_HOLE) 1910 return 0; 1911 1912 return (em->block_start + start - em->start) >> inode->i_blkbits; 1913 } 1914 1915 static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb) 1916 { 1917 if (list_empty(&eb->lru)) { 1918 extent_buffer_get(eb); 1919 list_add(&eb->lru, &tree->buffer_lru); 1920 tree->lru_size++; 1921 if (tree->lru_size >= BUFFER_LRU_MAX) { 1922 struct extent_buffer *rm; 1923 rm = list_entry(tree->buffer_lru.prev, 1924 struct extent_buffer, lru); 1925 tree->lru_size--; 1926 list_del(&rm->lru); 1927 free_extent_buffer(rm); 1928 } 1929 } else 1930 list_move(&eb->lru, &tree->buffer_lru); 1931 return 0; 1932 } 1933 static struct extent_buffer *find_lru(struct extent_map_tree *tree, 1934 u64 start, unsigned long len) 1935 { 1936 struct list_head *lru = &tree->buffer_lru; 1937 struct list_head *cur = lru->next; 1938 struct extent_buffer *eb; 1939 1940 if (list_empty(lru)) 1941 return NULL; 1942 1943 do { 1944 eb = list_entry(cur, struct extent_buffer, lru); 1945 if (eb->start == start && eb->len == len) { 1946 extent_buffer_get(eb); 1947 return eb; 1948 } 1949 cur = cur->next; 1950 } while (cur != lru); 1951 return NULL; 1952 } 1953 1954 static inline unsigned long num_extent_pages(u64 start, u64 len) 1955 { 1956 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - 1957 (start >> PAGE_CACHE_SHIFT); 1958 } 1959 1960 static inline struct page *extent_buffer_page(struct extent_buffer *eb, 1961 unsigned long i) 1962 { 1963 struct page *p; 1964 1965 if (i == 0) 1966 return eb->first_page; 1967 i += eb->start >> PAGE_CACHE_SHIFT; 1968 p = find_get_page(eb->first_page->mapping, i); 1969 page_cache_release(p); 1970 return p; 1971 } 1972 1973 static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, 1974 u64 start, 1975 unsigned long len, 1976 gfp_t mask) 1977 { 1978 struct extent_buffer *eb = NULL; 1979 1980 spin_lock(&tree->lru_lock); 1981 eb = find_lru(tree, start, len); 1982 if (eb) { 1983 goto lru_add; 1984 } 1985 spin_unlock(&tree->lru_lock); 1986 1987 if (eb) { 1988 memset(eb, 0, sizeof(*eb)); 1989 } else { 1990 eb = kmem_cache_zalloc(extent_buffer_cache, mask); 1991 } 1992 INIT_LIST_HEAD(&eb->lru); 1993 eb->start = start; 1994 eb->len = len; 1995 atomic_set(&eb->refs, 1); 1996 1997 spin_lock(&tree->lru_lock); 1998 lru_add: 1999 add_lru(tree, eb); 2000 spin_unlock(&tree->lru_lock); 2001 return eb; 2002 } 2003 2004 static void __free_extent_buffer(struct extent_buffer *eb) 2005 { 2006 kmem_cache_free(extent_buffer_cache, eb); 2007 } 2008 2009 struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 2010 u64 start, unsigned long len, 2011 struct page *page0, 2012 gfp_t mask) 2013 { 2014 unsigned long num_pages = num_extent_pages(start, len); 2015 unsigned long i; 2016 unsigned long index = start >> PAGE_CACHE_SHIFT; 2017 struct extent_buffer *eb; 2018 struct page *p; 2019 struct address_space *mapping = tree->mapping; 2020 int uptodate = 0; 2021 2022 eb = __alloc_extent_buffer(tree, start, len, mask); 2023 if (!eb || IS_ERR(eb)) 2024 return NULL; 2025 2026 if (eb->flags & EXTENT_BUFFER_FILLED) 2027 return eb; 2028 2029 if (page0) { 2030 eb->first_page = page0; 2031 i = 1; 2032 index++; 2033 page_cache_get(page0); 2034 mark_page_accessed(page0); 2035 set_page_extent_mapped(page0); 2036 set_page_private(page0, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2037 len << 2); 2038 } else { 2039 i = 0; 2040 } 2041 for (; i < num_pages; i++, index++) { 2042 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM); 2043 if (!p) { 2044 WARN_ON(1); 2045 /* make sure the free only frees the pages we've 2046 * grabbed a reference on 2047 */ 2048 eb->len = i << PAGE_CACHE_SHIFT; 2049 eb->start &= ~((u64)PAGE_CACHE_SIZE - 1); 2050 goto fail; 2051 } 2052 set_page_extent_mapped(p); 2053 mark_page_accessed(p); 2054 if (i == 0) { 2055 eb->first_page = p; 2056 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2057 len << 2); 2058 } else { 2059 set_page_private(p, EXTENT_PAGE_PRIVATE); 2060 } 2061 if (!PageUptodate(p)) 2062 uptodate = 0; 2063 unlock_page(p); 2064 } 2065 if (uptodate) 2066 eb->flags |= EXTENT_UPTODATE; 2067 eb->flags |= EXTENT_BUFFER_FILLED; 2068 return eb; 2069 fail: 2070 free_extent_buffer(eb); 2071 return NULL; 2072 } 2073 EXPORT_SYMBOL(alloc_extent_buffer); 2074 2075 struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 2076 u64 start, unsigned long len, 2077 gfp_t mask) 2078 { 2079 unsigned long num_pages = num_extent_pages(start, len); 2080 unsigned long i; unsigned long index = start >> PAGE_CACHE_SHIFT; 2081 struct extent_buffer *eb; 2082 struct page *p; 2083 struct address_space *mapping = tree->mapping; 2084 int uptodate = 1; 2085 2086 eb = __alloc_extent_buffer(tree, start, len, mask); 2087 if (!eb || IS_ERR(eb)) 2088 return NULL; 2089 2090 if (eb->flags & EXTENT_BUFFER_FILLED) 2091 return eb; 2092 2093 for (i = 0; i < num_pages; i++, index++) { 2094 p = find_lock_page(mapping, index); 2095 if (!p) { 2096 /* make sure the free only frees the pages we've 2097 * grabbed a reference on 2098 */ 2099 eb->len = i << PAGE_CACHE_SHIFT; 2100 eb->start &= ~((u64)PAGE_CACHE_SIZE - 1); 2101 goto fail; 2102 } 2103 set_page_extent_mapped(p); 2104 mark_page_accessed(p); 2105 2106 if (i == 0) { 2107 eb->first_page = p; 2108 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2109 len << 2); 2110 } else { 2111 set_page_private(p, EXTENT_PAGE_PRIVATE); 2112 } 2113 2114 if (!PageUptodate(p)) 2115 uptodate = 0; 2116 unlock_page(p); 2117 } 2118 if (uptodate) 2119 eb->flags |= EXTENT_UPTODATE; 2120 eb->flags |= EXTENT_BUFFER_FILLED; 2121 return eb; 2122 fail: 2123 free_extent_buffer(eb); 2124 return NULL; 2125 } 2126 EXPORT_SYMBOL(find_extent_buffer); 2127 2128 void free_extent_buffer(struct extent_buffer *eb) 2129 { 2130 unsigned long i; 2131 unsigned long num_pages; 2132 2133 if (!eb) 2134 return; 2135 2136 if (!atomic_dec_and_test(&eb->refs)) 2137 return; 2138 2139 num_pages = num_extent_pages(eb->start, eb->len); 2140 2141 for (i = 0; i < num_pages; i++) { 2142 page_cache_release(extent_buffer_page(eb, i)); 2143 } 2144 __free_extent_buffer(eb); 2145 } 2146 EXPORT_SYMBOL(free_extent_buffer); 2147 2148 int clear_extent_buffer_dirty(struct extent_map_tree *tree, 2149 struct extent_buffer *eb) 2150 { 2151 int set; 2152 unsigned long i; 2153 unsigned long num_pages; 2154 struct page *page; 2155 2156 u64 start = eb->start; 2157 u64 end = start + eb->len - 1; 2158 2159 set = clear_extent_dirty(tree, start, end, GFP_NOFS); 2160 num_pages = num_extent_pages(eb->start, eb->len); 2161 2162 for (i = 0; i < num_pages; i++) { 2163 page = extent_buffer_page(eb, i); 2164 lock_page(page); 2165 /* 2166 * if we're on the last page or the first page and the 2167 * block isn't aligned on a page boundary, do extra checks 2168 * to make sure we don't clean page that is partially dirty 2169 */ 2170 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2171 ((i == num_pages - 1) && 2172 ((eb->start + eb->len - 1) & (PAGE_CACHE_SIZE - 1)))) { 2173 start = page->index << PAGE_CACHE_SHIFT; 2174 end = start + PAGE_CACHE_SIZE - 1; 2175 if (test_range_bit(tree, start, end, 2176 EXTENT_DIRTY, 0)) { 2177 unlock_page(page); 2178 continue; 2179 } 2180 } 2181 clear_page_dirty_for_io(page); 2182 unlock_page(page); 2183 } 2184 return 0; 2185 } 2186 EXPORT_SYMBOL(clear_extent_buffer_dirty); 2187 2188 int wait_on_extent_buffer_writeback(struct extent_map_tree *tree, 2189 struct extent_buffer *eb) 2190 { 2191 return wait_on_extent_writeback(tree, eb->start, 2192 eb->start + eb->len - 1); 2193 } 2194 EXPORT_SYMBOL(wait_on_extent_buffer_writeback); 2195 2196 int set_extent_buffer_dirty(struct extent_map_tree *tree, 2197 struct extent_buffer *eb) 2198 { 2199 unsigned long i; 2200 unsigned long num_pages; 2201 2202 num_pages = num_extent_pages(eb->start, eb->len); 2203 for (i = 0; i < num_pages; i++) { 2204 struct page *page = extent_buffer_page(eb, i); 2205 /* writepage may need to do something special for the 2206 * first page, we have to make sure page->private is 2207 * properly set. releasepage may drop page->private 2208 * on us if the page isn't already dirty. 2209 */ 2210 if (i == 0) { 2211 lock_page(page); 2212 set_page_private(page, 2213 EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2214 eb->len << 2); 2215 } 2216 __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); 2217 if (i == 0) 2218 unlock_page(page); 2219 } 2220 return set_extent_dirty(tree, eb->start, 2221 eb->start + eb->len - 1, GFP_NOFS); 2222 } 2223 EXPORT_SYMBOL(set_extent_buffer_dirty); 2224 2225 int set_extent_buffer_uptodate(struct extent_map_tree *tree, 2226 struct extent_buffer *eb) 2227 { 2228 unsigned long i; 2229 struct page *page; 2230 unsigned long num_pages; 2231 2232 num_pages = num_extent_pages(eb->start, eb->len); 2233 2234 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, 2235 GFP_NOFS); 2236 for (i = 0; i < num_pages; i++) { 2237 page = extent_buffer_page(eb, i); 2238 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2239 ((i == num_pages - 1) && 2240 ((eb->start + eb->len - 1) & (PAGE_CACHE_SIZE - 1)))) { 2241 check_page_uptodate(tree, page); 2242 continue; 2243 } 2244 SetPageUptodate(page); 2245 } 2246 return 0; 2247 } 2248 EXPORT_SYMBOL(set_extent_buffer_uptodate); 2249 2250 int extent_buffer_uptodate(struct extent_map_tree *tree, 2251 struct extent_buffer *eb) 2252 { 2253 if (eb->flags & EXTENT_UPTODATE) 2254 return 1; 2255 return test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2256 EXTENT_UPTODATE, 1); 2257 } 2258 EXPORT_SYMBOL(extent_buffer_uptodate); 2259 2260 int read_extent_buffer_pages(struct extent_map_tree *tree, 2261 struct extent_buffer *eb, 2262 u64 start, 2263 int wait) 2264 { 2265 unsigned long i; 2266 unsigned long start_i; 2267 struct page *page; 2268 int err; 2269 int ret = 0; 2270 unsigned long num_pages; 2271 2272 if (eb->flags & EXTENT_UPTODATE) 2273 return 0; 2274 2275 if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2276 EXTENT_UPTODATE, 1)) { 2277 return 0; 2278 } 2279 if (start) { 2280 WARN_ON(start < eb->start); 2281 start_i = (start >> PAGE_CACHE_SHIFT) - 2282 (eb->start >> PAGE_CACHE_SHIFT); 2283 } else { 2284 start_i = 0; 2285 } 2286 2287 num_pages = num_extent_pages(eb->start, eb->len); 2288 for (i = start_i; i < num_pages; i++) { 2289 page = extent_buffer_page(eb, i); 2290 if (PageUptodate(page)) { 2291 continue; 2292 } 2293 if (!wait) { 2294 if (TestSetPageLocked(page)) { 2295 continue; 2296 } 2297 } else { 2298 lock_page(page); 2299 } 2300 if (!PageUptodate(page)) { 2301 err = page->mapping->a_ops->readpage(NULL, page); 2302 if (err) { 2303 ret = err; 2304 } 2305 } else { 2306 unlock_page(page); 2307 } 2308 } 2309 2310 if (ret || !wait) { 2311 return ret; 2312 } 2313 2314 for (i = start_i; i < num_pages; i++) { 2315 page = extent_buffer_page(eb, i); 2316 wait_on_page_locked(page); 2317 if (!PageUptodate(page)) { 2318 ret = -EIO; 2319 } 2320 } 2321 if (!ret) 2322 eb->flags |= EXTENT_UPTODATE; 2323 return ret; 2324 } 2325 EXPORT_SYMBOL(read_extent_buffer_pages); 2326 2327 void read_extent_buffer(struct extent_buffer *eb, void *dstv, 2328 unsigned long start, 2329 unsigned long len) 2330 { 2331 size_t cur; 2332 size_t offset; 2333 struct page *page; 2334 char *kaddr; 2335 char *dst = (char *)dstv; 2336 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2337 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2338 unsigned long num_pages = num_extent_pages(eb->start, eb->len); 2339 2340 WARN_ON(start > eb->len); 2341 WARN_ON(start + len > eb->start + eb->len); 2342 2343 offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1); 2344 if (i == 0) 2345 offset += start_offset; 2346 2347 while(len > 0) { 2348 page = extent_buffer_page(eb, i); 2349 if (!PageUptodate(page)) { 2350 printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); 2351 WARN_ON(1); 2352 } 2353 WARN_ON(!PageUptodate(page)); 2354 2355 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2356 kaddr = kmap_atomic(page, KM_USER0); 2357 memcpy(dst, kaddr + offset, cur); 2358 kunmap_atomic(kaddr, KM_USER0); 2359 2360 dst += cur; 2361 len -= cur; 2362 offset = 0; 2363 i++; 2364 } 2365 } 2366 EXPORT_SYMBOL(read_extent_buffer); 2367 2368 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, 2369 unsigned long min_len, char **token, char **map, 2370 unsigned long *map_start, 2371 unsigned long *map_len, int km) 2372 { 2373 size_t offset = start & (PAGE_CACHE_SIZE - 1); 2374 char *kaddr; 2375 struct page *p; 2376 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2377 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2378 unsigned long end_i = (start_offset + start + min_len) >> 2379 PAGE_CACHE_SHIFT; 2380 2381 if (i != end_i) 2382 return -EINVAL; 2383 2384 if (i == 0) { 2385 offset = start_offset; 2386 *map_start = 0; 2387 } else { 2388 offset = 0; 2389 *map_start = (i << PAGE_CACHE_SHIFT) - start_offset; 2390 } 2391 if (start + min_len >= eb->len) { 2392 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); 2393 WARN_ON(1); 2394 } 2395 2396 p = extent_buffer_page(eb, i); 2397 WARN_ON(!PageUptodate(p)); 2398 kaddr = kmap_atomic(p, km); 2399 *token = kaddr; 2400 *map = kaddr + offset; 2401 *map_len = PAGE_CACHE_SIZE - offset; 2402 return 0; 2403 } 2404 EXPORT_SYMBOL(map_private_extent_buffer); 2405 2406 int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 2407 unsigned long min_len, 2408 char **token, char **map, 2409 unsigned long *map_start, 2410 unsigned long *map_len, int km) 2411 { 2412 int err; 2413 int save = 0; 2414 if (eb->map_token) { 2415 unmap_extent_buffer(eb, eb->map_token, km); 2416 eb->map_token = NULL; 2417 save = 1; 2418 } 2419 err = map_private_extent_buffer(eb, start, min_len, token, map, 2420 map_start, map_len, km); 2421 if (!err && save) { 2422 eb->map_token = *token; 2423 eb->kaddr = *map; 2424 eb->map_start = *map_start; 2425 eb->map_len = *map_len; 2426 } 2427 return err; 2428 } 2429 EXPORT_SYMBOL(map_extent_buffer); 2430 2431 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) 2432 { 2433 kunmap_atomic(token, km); 2434 } 2435 EXPORT_SYMBOL(unmap_extent_buffer); 2436 2437 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 2438 unsigned long start, 2439 unsigned long len) 2440 { 2441 size_t cur; 2442 size_t offset; 2443 struct page *page; 2444 char *kaddr; 2445 char *ptr = (char *)ptrv; 2446 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2447 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2448 int ret = 0; 2449 2450 WARN_ON(start > eb->len); 2451 WARN_ON(start + len > eb->start + eb->len); 2452 2453 offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1); 2454 if (i == 0) 2455 offset += start_offset; 2456 2457 while(len > 0) { 2458 page = extent_buffer_page(eb, i); 2459 WARN_ON(!PageUptodate(page)); 2460 2461 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2462 2463 kaddr = kmap_atomic(page, KM_USER0); 2464 ret = memcmp(ptr, kaddr + offset, cur); 2465 kunmap_atomic(kaddr, KM_USER0); 2466 if (ret) 2467 break; 2468 2469 ptr += cur; 2470 len -= cur; 2471 offset = 0; 2472 i++; 2473 } 2474 return ret; 2475 } 2476 EXPORT_SYMBOL(memcmp_extent_buffer); 2477 2478 void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 2479 unsigned long start, unsigned long len) 2480 { 2481 size_t cur; 2482 size_t offset; 2483 struct page *page; 2484 char *kaddr; 2485 char *src = (char *)srcv; 2486 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2487 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2488 2489 WARN_ON(start > eb->len); 2490 WARN_ON(start + len > eb->start + eb->len); 2491 2492 offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1); 2493 if (i == 0) 2494 offset += start_offset; 2495 2496 while(len > 0) { 2497 page = extent_buffer_page(eb, i); 2498 WARN_ON(!PageUptodate(page)); 2499 2500 cur = min(len, PAGE_CACHE_SIZE - offset); 2501 kaddr = kmap_atomic(page, KM_USER0); 2502 memcpy(kaddr + offset, src, cur); 2503 kunmap_atomic(kaddr, KM_USER0); 2504 2505 src += cur; 2506 len -= cur; 2507 offset = 0; 2508 i++; 2509 } 2510 } 2511 EXPORT_SYMBOL(write_extent_buffer); 2512 2513 void memset_extent_buffer(struct extent_buffer *eb, char c, 2514 unsigned long start, unsigned long len) 2515 { 2516 size_t cur; 2517 size_t offset; 2518 struct page *page; 2519 char *kaddr; 2520 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2521 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2522 2523 WARN_ON(start > eb->len); 2524 WARN_ON(start + len > eb->start + eb->len); 2525 2526 offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1); 2527 if (i == 0) 2528 offset += start_offset; 2529 2530 while(len > 0) { 2531 page = extent_buffer_page(eb, i); 2532 WARN_ON(!PageUptodate(page)); 2533 2534 cur = min(len, PAGE_CACHE_SIZE - offset); 2535 kaddr = kmap_atomic(page, KM_USER0); 2536 memset(kaddr + offset, c, cur); 2537 kunmap_atomic(kaddr, KM_USER0); 2538 2539 len -= cur; 2540 offset = 0; 2541 i++; 2542 } 2543 } 2544 EXPORT_SYMBOL(memset_extent_buffer); 2545 2546 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 2547 unsigned long dst_offset, unsigned long src_offset, 2548 unsigned long len) 2549 { 2550 u64 dst_len = dst->len; 2551 size_t cur; 2552 size_t offset; 2553 struct page *page; 2554 char *kaddr; 2555 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2556 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2557 2558 WARN_ON(src->len != dst_len); 2559 2560 offset = dst_offset & ((unsigned long)PAGE_CACHE_SIZE - 1); 2561 if (i == 0) 2562 offset += start_offset; 2563 2564 while(len > 0) { 2565 page = extent_buffer_page(dst, i); 2566 WARN_ON(!PageUptodate(page)); 2567 2568 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset)); 2569 2570 kaddr = kmap_atomic(page, KM_USER1); 2571 read_extent_buffer(src, kaddr + offset, src_offset, cur); 2572 kunmap_atomic(kaddr, KM_USER1); 2573 2574 src_offset += cur; 2575 len -= cur; 2576 offset = 0; 2577 i++; 2578 } 2579 } 2580 EXPORT_SYMBOL(copy_extent_buffer); 2581 2582 static void move_pages(struct page *dst_page, struct page *src_page, 2583 unsigned long dst_off, unsigned long src_off, 2584 unsigned long len) 2585 { 2586 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2587 if (dst_page == src_page) { 2588 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len); 2589 } else { 2590 char *src_kaddr = kmap_atomic(src_page, KM_USER1); 2591 char *p = dst_kaddr + dst_off + len; 2592 char *s = src_kaddr + src_off + len; 2593 2594 while (len--) 2595 *--p = *--s; 2596 2597 kunmap_atomic(src_kaddr, KM_USER1); 2598 } 2599 kunmap_atomic(dst_kaddr, KM_USER0); 2600 } 2601 2602 static void copy_pages(struct page *dst_page, struct page *src_page, 2603 unsigned long dst_off, unsigned long src_off, 2604 unsigned long len) 2605 { 2606 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2607 char *src_kaddr; 2608 2609 if (dst_page != src_page) 2610 src_kaddr = kmap_atomic(src_page, KM_USER1); 2611 else 2612 src_kaddr = dst_kaddr; 2613 2614 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); 2615 kunmap_atomic(dst_kaddr, KM_USER0); 2616 if (dst_page != src_page) 2617 kunmap_atomic(src_kaddr, KM_USER1); 2618 } 2619 2620 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2621 unsigned long src_offset, unsigned long len) 2622 { 2623 size_t cur; 2624 size_t dst_off_in_page; 2625 size_t src_off_in_page; 2626 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2627 unsigned long dst_i; 2628 unsigned long src_i; 2629 2630 if (src_offset + len > dst->len) { 2631 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2632 src_offset, len, dst->len); 2633 BUG_ON(1); 2634 } 2635 if (dst_offset + len > dst->len) { 2636 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2637 dst_offset, len, dst->len); 2638 BUG_ON(1); 2639 } 2640 2641 while(len > 0) { 2642 dst_off_in_page = dst_offset & 2643 ((unsigned long)PAGE_CACHE_SIZE - 1); 2644 src_off_in_page = src_offset & 2645 ((unsigned long)PAGE_CACHE_SIZE - 1); 2646 2647 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2648 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT; 2649 2650 if (src_i == 0) 2651 src_off_in_page += start_offset; 2652 if (dst_i == 0) 2653 dst_off_in_page += start_offset; 2654 2655 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - 2656 src_off_in_page)); 2657 cur = min(cur, (unsigned long)(PAGE_CACHE_SIZE - 2658 dst_off_in_page)); 2659 2660 copy_pages(extent_buffer_page(dst, dst_i), 2661 extent_buffer_page(dst, src_i), 2662 dst_off_in_page, src_off_in_page, cur); 2663 2664 src_offset += cur; 2665 dst_offset += cur; 2666 len -= cur; 2667 } 2668 } 2669 EXPORT_SYMBOL(memcpy_extent_buffer); 2670 2671 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2672 unsigned long src_offset, unsigned long len) 2673 { 2674 size_t cur; 2675 size_t dst_off_in_page; 2676 size_t src_off_in_page; 2677 unsigned long dst_end = dst_offset + len - 1; 2678 unsigned long src_end = src_offset + len - 1; 2679 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2680 unsigned long dst_i; 2681 unsigned long src_i; 2682 2683 if (src_offset + len > dst->len) { 2684 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2685 src_offset, len, dst->len); 2686 BUG_ON(1); 2687 } 2688 if (dst_offset + len > dst->len) { 2689 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2690 dst_offset, len, dst->len); 2691 BUG_ON(1); 2692 } 2693 if (dst_offset < src_offset) { 2694 memcpy_extent_buffer(dst, dst_offset, src_offset, len); 2695 return; 2696 } 2697 while(len > 0) { 2698 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT; 2699 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT; 2700 2701 dst_off_in_page = dst_end & 2702 ((unsigned long)PAGE_CACHE_SIZE - 1); 2703 src_off_in_page = src_end & 2704 ((unsigned long)PAGE_CACHE_SIZE - 1); 2705 if (src_i == 0) 2706 src_off_in_page += start_offset; 2707 if (dst_i == 0) 2708 dst_off_in_page += start_offset; 2709 2710 cur = min(len, src_off_in_page + 1); 2711 cur = min(cur, dst_off_in_page + 1); 2712 move_pages(extent_buffer_page(dst, dst_i), 2713 extent_buffer_page(dst, src_i), 2714 dst_off_in_page - cur + 1, 2715 src_off_in_page - cur + 1, cur); 2716 2717 dst_end -= cur; 2718 src_end -= cur; 2719 len -= cur; 2720 } 2721 } 2722 EXPORT_SYMBOL(memmove_extent_buffer); 2723