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 <linux/version.h> 13 #include "extent_map.h" 14 15 /* temporary define until extent_map moves out of btrfs */ 16 struct kmem_cache *btrfs_cache_create(const char *name, size_t size, 17 unsigned long extra_flags, 18 void (*ctor)(void *, struct kmem_cache *, 19 unsigned long)); 20 21 static struct kmem_cache *extent_map_cache; 22 static struct kmem_cache *extent_state_cache; 23 static struct kmem_cache *extent_buffer_cache; 24 25 static LIST_HEAD(buffers); 26 static LIST_HEAD(states); 27 28 static spinlock_t state_lock = SPIN_LOCK_UNLOCKED; 29 #define BUFFER_LRU_MAX 64 30 31 struct tree_entry { 32 u64 start; 33 u64 end; 34 int in_tree; 35 struct rb_node rb_node; 36 }; 37 38 void __init extent_map_init(void) 39 { 40 extent_map_cache = btrfs_cache_create("extent_map", 41 sizeof(struct extent_map), 0, 42 NULL); 43 extent_state_cache = btrfs_cache_create("extent_state", 44 sizeof(struct extent_state), 0, 45 NULL); 46 extent_buffer_cache = btrfs_cache_create("extent_buffers", 47 sizeof(struct extent_buffer), 0, 48 NULL); 49 } 50 51 void __exit extent_map_exit(void) 52 { 53 struct extent_state *state; 54 55 while (!list_empty(&states)) { 56 state = list_entry(states.next, struct extent_state, list); 57 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)); 58 list_del(&state->list); 59 kmem_cache_free(extent_state_cache, state); 60 61 } 62 63 if (extent_map_cache) 64 kmem_cache_destroy(extent_map_cache); 65 if (extent_state_cache) 66 kmem_cache_destroy(extent_state_cache); 67 if (extent_buffer_cache) 68 kmem_cache_destroy(extent_buffer_cache); 69 } 70 71 void extent_map_tree_init(struct extent_map_tree *tree, 72 struct address_space *mapping, gfp_t mask) 73 { 74 tree->map.rb_node = NULL; 75 tree->state.rb_node = NULL; 76 tree->ops = NULL; 77 rwlock_init(&tree->lock); 78 spin_lock_init(&tree->lru_lock); 79 tree->mapping = mapping; 80 INIT_LIST_HEAD(&tree->buffer_lru); 81 tree->lru_size = 0; 82 } 83 EXPORT_SYMBOL(extent_map_tree_init); 84 85 void extent_map_tree_empty_lru(struct extent_map_tree *tree) 86 { 87 struct extent_buffer *eb; 88 while(!list_empty(&tree->buffer_lru)) { 89 eb = list_entry(tree->buffer_lru.next, struct extent_buffer, 90 lru); 91 list_del(&eb->lru); 92 free_extent_buffer(eb); 93 } 94 } 95 EXPORT_SYMBOL(extent_map_tree_empty_lru); 96 97 struct extent_map *alloc_extent_map(gfp_t mask) 98 { 99 struct extent_map *em; 100 em = kmem_cache_alloc(extent_map_cache, mask); 101 if (!em || IS_ERR(em)) 102 return em; 103 em->in_tree = 0; 104 atomic_set(&em->refs, 1); 105 return em; 106 } 107 EXPORT_SYMBOL(alloc_extent_map); 108 109 void free_extent_map(struct extent_map *em) 110 { 111 if (!em) 112 return; 113 if (atomic_dec_and_test(&em->refs)) { 114 WARN_ON(em->in_tree); 115 kmem_cache_free(extent_map_cache, em); 116 } 117 } 118 EXPORT_SYMBOL(free_extent_map); 119 120 121 struct extent_state *alloc_extent_state(gfp_t mask) 122 { 123 struct extent_state *state; 124 unsigned long flags; 125 126 state = kmem_cache_alloc(extent_state_cache, mask); 127 if (!state || IS_ERR(state)) 128 return state; 129 state->state = 0; 130 state->in_tree = 0; 131 state->private = 0; 132 133 spin_lock_irqsave(&state_lock, flags); 134 list_add(&state->list, &states); 135 spin_unlock_irqrestore(&state_lock, flags); 136 137 atomic_set(&state->refs, 1); 138 init_waitqueue_head(&state->wq); 139 return state; 140 } 141 EXPORT_SYMBOL(alloc_extent_state); 142 143 void free_extent_state(struct extent_state *state) 144 { 145 unsigned long flags; 146 if (!state) 147 return; 148 if (atomic_dec_and_test(&state->refs)) { 149 WARN_ON(state->in_tree); 150 spin_lock_irqsave(&state_lock, flags); 151 list_del(&state->list); 152 spin_unlock_irqrestore(&state_lock, flags); 153 kmem_cache_free(extent_state_cache, state); 154 } 155 } 156 EXPORT_SYMBOL(free_extent_state); 157 158 static struct rb_node *tree_insert(struct rb_root *root, u64 offset, 159 struct rb_node *node) 160 { 161 struct rb_node ** p = &root->rb_node; 162 struct rb_node * parent = NULL; 163 struct tree_entry *entry; 164 165 while(*p) { 166 parent = *p; 167 entry = rb_entry(parent, struct tree_entry, rb_node); 168 169 if (offset < entry->start) 170 p = &(*p)->rb_left; 171 else if (offset > entry->end) 172 p = &(*p)->rb_right; 173 else 174 return parent; 175 } 176 177 entry = rb_entry(node, struct tree_entry, rb_node); 178 entry->in_tree = 1; 179 rb_link_node(node, parent, p); 180 rb_insert_color(node, root); 181 return NULL; 182 } 183 184 static struct rb_node *__tree_search(struct rb_root *root, u64 offset, 185 struct rb_node **prev_ret) 186 { 187 struct rb_node * n = root->rb_node; 188 struct rb_node *prev = NULL; 189 struct tree_entry *entry; 190 struct tree_entry *prev_entry = NULL; 191 192 while(n) { 193 entry = rb_entry(n, struct tree_entry, rb_node); 194 prev = n; 195 prev_entry = entry; 196 197 if (offset < entry->start) 198 n = n->rb_left; 199 else if (offset > entry->end) 200 n = n->rb_right; 201 else 202 return n; 203 } 204 if (!prev_ret) 205 return NULL; 206 while(prev && offset > prev_entry->end) { 207 prev = rb_next(prev); 208 prev_entry = rb_entry(prev, struct tree_entry, rb_node); 209 } 210 *prev_ret = prev; 211 return NULL; 212 } 213 214 static inline struct rb_node *tree_search(struct rb_root *root, u64 offset) 215 { 216 struct rb_node *prev; 217 struct rb_node *ret; 218 ret = __tree_search(root, offset, &prev); 219 if (!ret) 220 return prev; 221 return ret; 222 } 223 224 static int tree_delete(struct rb_root *root, u64 offset) 225 { 226 struct rb_node *node; 227 struct tree_entry *entry; 228 229 node = __tree_search(root, offset, NULL); 230 if (!node) 231 return -ENOENT; 232 entry = rb_entry(node, struct tree_entry, rb_node); 233 entry->in_tree = 0; 234 rb_erase(node, root); 235 return 0; 236 } 237 238 /* 239 * add_extent_mapping tries a simple backward merge with existing 240 * mappings. The extent_map struct passed in will be inserted into 241 * the tree directly (no copies made, just a reference taken). 242 */ 243 int add_extent_mapping(struct extent_map_tree *tree, 244 struct extent_map *em) 245 { 246 int ret = 0; 247 struct extent_map *prev = NULL; 248 struct rb_node *rb; 249 250 write_lock_irq(&tree->lock); 251 rb = tree_insert(&tree->map, em->end, &em->rb_node); 252 if (rb) { 253 prev = rb_entry(rb, struct extent_map, rb_node); 254 printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev->start, prev->end, em->start, em->end); 255 ret = -EEXIST; 256 goto out; 257 } 258 atomic_inc(&em->refs); 259 if (em->start != 0) { 260 rb = rb_prev(&em->rb_node); 261 if (rb) 262 prev = rb_entry(rb, struct extent_map, rb_node); 263 if (prev && prev->end + 1 == em->start && 264 ((em->block_start == EXTENT_MAP_HOLE && 265 prev->block_start == EXTENT_MAP_HOLE) || 266 (em->block_start == EXTENT_MAP_INLINE && 267 prev->block_start == EXTENT_MAP_INLINE) || 268 (em->block_start == EXTENT_MAP_DELALLOC && 269 prev->block_start == EXTENT_MAP_DELALLOC) || 270 (em->block_start < EXTENT_MAP_DELALLOC - 1 && 271 em->block_start == prev->block_end + 1))) { 272 em->start = prev->start; 273 em->block_start = prev->block_start; 274 rb_erase(&prev->rb_node, &tree->map); 275 prev->in_tree = 0; 276 free_extent_map(prev); 277 } 278 } 279 out: 280 write_unlock_irq(&tree->lock); 281 return ret; 282 } 283 EXPORT_SYMBOL(add_extent_mapping); 284 285 /* 286 * lookup_extent_mapping returns the first extent_map struct in the 287 * tree that intersects the [start, end] (inclusive) range. There may 288 * be additional objects in the tree that intersect, so check the object 289 * returned carefully to make sure you don't need additional lookups. 290 */ 291 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, 292 u64 start, u64 end) 293 { 294 struct extent_map *em; 295 struct rb_node *rb_node; 296 297 read_lock_irq(&tree->lock); 298 rb_node = tree_search(&tree->map, start); 299 if (!rb_node) { 300 em = NULL; 301 goto out; 302 } 303 if (IS_ERR(rb_node)) { 304 em = ERR_PTR(PTR_ERR(rb_node)); 305 goto out; 306 } 307 em = rb_entry(rb_node, struct extent_map, rb_node); 308 if (em->end < start || em->start > end) { 309 em = NULL; 310 goto out; 311 } 312 atomic_inc(&em->refs); 313 out: 314 read_unlock_irq(&tree->lock); 315 return em; 316 } 317 EXPORT_SYMBOL(lookup_extent_mapping); 318 319 /* 320 * removes an extent_map struct from the tree. No reference counts are 321 * dropped, and no checks are done to see if the range is in use 322 */ 323 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) 324 { 325 int ret; 326 327 write_lock_irq(&tree->lock); 328 ret = tree_delete(&tree->map, em->end); 329 write_unlock_irq(&tree->lock); 330 return ret; 331 } 332 EXPORT_SYMBOL(remove_extent_mapping); 333 334 /* 335 * utility function to look for merge candidates inside a given range. 336 * Any extents with matching state are merged together into a single 337 * extent in the tree. Extents with EXTENT_IO in their state field 338 * are not merged because the end_io handlers need to be able to do 339 * operations on them without sleeping (or doing allocations/splits). 340 * 341 * This should be called with the tree lock held. 342 */ 343 static int merge_state(struct extent_map_tree *tree, 344 struct extent_state *state) 345 { 346 struct extent_state *other; 347 struct rb_node *other_node; 348 349 if (state->state & EXTENT_IOBITS) 350 return 0; 351 352 other_node = rb_prev(&state->rb_node); 353 if (other_node) { 354 other = rb_entry(other_node, struct extent_state, rb_node); 355 if (other->end == state->start - 1 && 356 other->state == state->state) { 357 state->start = other->start; 358 other->in_tree = 0; 359 rb_erase(&other->rb_node, &tree->state); 360 free_extent_state(other); 361 } 362 } 363 other_node = rb_next(&state->rb_node); 364 if (other_node) { 365 other = rb_entry(other_node, struct extent_state, rb_node); 366 if (other->start == state->end + 1 && 367 other->state == state->state) { 368 other->start = state->start; 369 state->in_tree = 0; 370 rb_erase(&state->rb_node, &tree->state); 371 free_extent_state(state); 372 } 373 } 374 return 0; 375 } 376 377 /* 378 * insert an extent_state struct into the tree. 'bits' are set on the 379 * struct before it is inserted. 380 * 381 * This may return -EEXIST if the extent is already there, in which case the 382 * state struct is freed. 383 * 384 * The tree lock is not taken internally. This is a utility function and 385 * probably isn't what you want to call (see set/clear_extent_bit). 386 */ 387 static int insert_state(struct extent_map_tree *tree, 388 struct extent_state *state, u64 start, u64 end, 389 int bits) 390 { 391 struct rb_node *node; 392 393 if (end < start) { 394 printk("end < start %Lu %Lu\n", end, start); 395 WARN_ON(1); 396 } 397 state->state |= bits; 398 state->start = start; 399 state->end = end; 400 node = tree_insert(&tree->state, end, &state->rb_node); 401 if (node) { 402 struct extent_state *found; 403 found = rb_entry(node, struct extent_state, rb_node); 404 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end); 405 free_extent_state(state); 406 return -EEXIST; 407 } 408 merge_state(tree, state); 409 return 0; 410 } 411 412 /* 413 * split a given extent state struct in two, inserting the preallocated 414 * struct 'prealloc' as the newly created second half. 'split' indicates an 415 * offset inside 'orig' where it should be split. 416 * 417 * Before calling, 418 * the tree has 'orig' at [orig->start, orig->end]. After calling, there 419 * are two extent state structs in the tree: 420 * prealloc: [orig->start, split - 1] 421 * orig: [ split, orig->end ] 422 * 423 * The tree locks are not taken by this function. They need to be held 424 * by the caller. 425 */ 426 static int split_state(struct extent_map_tree *tree, struct extent_state *orig, 427 struct extent_state *prealloc, u64 split) 428 { 429 struct rb_node *node; 430 prealloc->start = orig->start; 431 prealloc->end = split - 1; 432 prealloc->state = orig->state; 433 orig->start = split; 434 435 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node); 436 if (node) { 437 struct extent_state *found; 438 found = rb_entry(node, struct extent_state, rb_node); 439 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end); 440 free_extent_state(prealloc); 441 return -EEXIST; 442 } 443 return 0; 444 } 445 446 /* 447 * utility function to clear some bits in an extent state struct. 448 * it will optionally wake up any one waiting on this state (wake == 1), or 449 * forcibly remove the state from the tree (delete == 1). 450 * 451 * If no bits are set on the state struct after clearing things, the 452 * struct is freed and removed from the tree 453 */ 454 static int clear_state_bit(struct extent_map_tree *tree, 455 struct extent_state *state, int bits, int wake, 456 int delete) 457 { 458 int ret = state->state & bits; 459 state->state &= ~bits; 460 if (wake) 461 wake_up(&state->wq); 462 if (delete || state->state == 0) { 463 if (state->in_tree) { 464 rb_erase(&state->rb_node, &tree->state); 465 state->in_tree = 0; 466 free_extent_state(state); 467 } else { 468 WARN_ON(1); 469 } 470 } else { 471 merge_state(tree, state); 472 } 473 return ret; 474 } 475 476 /* 477 * clear some bits on a range in the tree. This may require splitting 478 * or inserting elements in the tree, so the gfp mask is used to 479 * indicate which allocations or sleeping are allowed. 480 * 481 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove 482 * the given range from the tree regardless of state (ie for truncate). 483 * 484 * the range [start, end] is inclusive. 485 * 486 * This takes the tree lock, and returns < 0 on error, > 0 if any of the 487 * bits were already set, or zero if none of the bits were already set. 488 */ 489 int clear_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, 490 int bits, int wake, int delete, gfp_t mask) 491 { 492 struct extent_state *state; 493 struct extent_state *prealloc = NULL; 494 struct rb_node *node; 495 unsigned long flags; 496 int err; 497 int set = 0; 498 499 again: 500 if (!prealloc && (mask & __GFP_WAIT)) { 501 prealloc = alloc_extent_state(mask); 502 if (!prealloc) 503 return -ENOMEM; 504 } 505 506 write_lock_irqsave(&tree->lock, flags); 507 /* 508 * this search will find the extents that end after 509 * our range starts 510 */ 511 node = tree_search(&tree->state, start); 512 if (!node) 513 goto out; 514 state = rb_entry(node, struct extent_state, rb_node); 515 if (state->start > end) 516 goto out; 517 WARN_ON(state->end < start); 518 519 /* 520 * | ---- desired range ---- | 521 * | state | or 522 * | ------------- state -------------- | 523 * 524 * We need to split the extent we found, and may flip 525 * bits on second half. 526 * 527 * If the extent we found extends past our range, we 528 * just split and search again. It'll get split again 529 * the next time though. 530 * 531 * If the extent we found is inside our range, we clear 532 * the desired bit on it. 533 */ 534 535 if (state->start < start) { 536 err = split_state(tree, state, prealloc, start); 537 BUG_ON(err == -EEXIST); 538 prealloc = NULL; 539 if (err) 540 goto out; 541 if (state->end <= end) { 542 start = state->end + 1; 543 set |= clear_state_bit(tree, state, bits, 544 wake, delete); 545 } else { 546 start = state->start; 547 } 548 goto search_again; 549 } 550 /* 551 * | ---- desired range ---- | 552 * | state | 553 * We need to split the extent, and clear the bit 554 * on the first half 555 */ 556 if (state->start <= end && state->end > end) { 557 err = split_state(tree, state, prealloc, end + 1); 558 BUG_ON(err == -EEXIST); 559 560 if (wake) 561 wake_up(&state->wq); 562 set |= clear_state_bit(tree, prealloc, bits, 563 wake, delete); 564 prealloc = NULL; 565 goto out; 566 } 567 568 start = state->end + 1; 569 set |= clear_state_bit(tree, state, bits, wake, delete); 570 goto search_again; 571 572 out: 573 write_unlock_irqrestore(&tree->lock, flags); 574 if (prealloc) 575 free_extent_state(prealloc); 576 577 return set; 578 579 search_again: 580 if (start > end) 581 goto out; 582 write_unlock_irqrestore(&tree->lock, flags); 583 if (mask & __GFP_WAIT) 584 cond_resched(); 585 goto again; 586 } 587 EXPORT_SYMBOL(clear_extent_bit); 588 589 static int wait_on_state(struct extent_map_tree *tree, 590 struct extent_state *state) 591 { 592 DEFINE_WAIT(wait); 593 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); 594 read_unlock_irq(&tree->lock); 595 schedule(); 596 read_lock_irq(&tree->lock); 597 finish_wait(&state->wq, &wait); 598 return 0; 599 } 600 601 /* 602 * waits for one or more bits to clear on a range in the state tree. 603 * The range [start, end] is inclusive. 604 * The tree lock is taken by this function 605 */ 606 int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits) 607 { 608 struct extent_state *state; 609 struct rb_node *node; 610 611 read_lock_irq(&tree->lock); 612 again: 613 while (1) { 614 /* 615 * this search will find all the extents that end after 616 * our range starts 617 */ 618 node = tree_search(&tree->state, start); 619 if (!node) 620 break; 621 622 state = rb_entry(node, struct extent_state, rb_node); 623 624 if (state->start > end) 625 goto out; 626 627 if (state->state & bits) { 628 start = state->start; 629 atomic_inc(&state->refs); 630 wait_on_state(tree, state); 631 free_extent_state(state); 632 goto again; 633 } 634 start = state->end + 1; 635 636 if (start > end) 637 break; 638 639 if (need_resched()) { 640 read_unlock_irq(&tree->lock); 641 cond_resched(); 642 read_lock_irq(&tree->lock); 643 } 644 } 645 out: 646 read_unlock_irq(&tree->lock); 647 return 0; 648 } 649 EXPORT_SYMBOL(wait_extent_bit); 650 651 /* 652 * set some bits on a range in the tree. This may require allocations 653 * or sleeping, so the gfp mask is used to indicate what is allowed. 654 * 655 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the 656 * range already has the desired bits set. The start of the existing 657 * range is returned in failed_start in this case. 658 * 659 * [start, end] is inclusive 660 * This takes the tree lock. 661 */ 662 int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, 663 int exclusive, u64 *failed_start, gfp_t mask) 664 { 665 struct extent_state *state; 666 struct extent_state *prealloc = NULL; 667 struct rb_node *node; 668 unsigned long flags; 669 int err = 0; 670 int set; 671 u64 last_start; 672 u64 last_end; 673 again: 674 if (!prealloc && (mask & __GFP_WAIT)) { 675 prealloc = alloc_extent_state(mask); 676 if (!prealloc) 677 return -ENOMEM; 678 } 679 680 write_lock_irqsave(&tree->lock, flags); 681 /* 682 * this search will find all the extents that end after 683 * our range starts. 684 */ 685 node = tree_search(&tree->state, start); 686 if (!node) { 687 err = insert_state(tree, prealloc, start, end, bits); 688 prealloc = NULL; 689 BUG_ON(err == -EEXIST); 690 goto out; 691 } 692 693 state = rb_entry(node, struct extent_state, rb_node); 694 last_start = state->start; 695 last_end = state->end; 696 697 /* 698 * | ---- desired range ---- | 699 * | state | 700 * 701 * Just lock what we found and keep going 702 */ 703 if (state->start == start && state->end <= end) { 704 set = state->state & bits; 705 if (set && exclusive) { 706 *failed_start = state->start; 707 err = -EEXIST; 708 goto out; 709 } 710 state->state |= bits; 711 start = state->end + 1; 712 merge_state(tree, state); 713 goto search_again; 714 } 715 716 /* 717 * | ---- desired range ---- | 718 * | state | 719 * or 720 * | ------------- state -------------- | 721 * 722 * We need to split the extent we found, and may flip bits on 723 * second half. 724 * 725 * If the extent we found extends past our 726 * range, we just split and search again. It'll get split 727 * again the next time though. 728 * 729 * If the extent we found is inside our range, we set the 730 * desired bit on it. 731 */ 732 if (state->start < start) { 733 set = state->state & bits; 734 if (exclusive && set) { 735 *failed_start = start; 736 err = -EEXIST; 737 goto out; 738 } 739 err = split_state(tree, state, prealloc, start); 740 BUG_ON(err == -EEXIST); 741 prealloc = NULL; 742 if (err) 743 goto out; 744 if (state->end <= end) { 745 state->state |= bits; 746 start = state->end + 1; 747 merge_state(tree, state); 748 } else { 749 start = state->start; 750 } 751 goto search_again; 752 } 753 /* 754 * | ---- desired range ---- | 755 * | state | or | state | 756 * 757 * There's a hole, we need to insert something in it and 758 * ignore the extent we found. 759 */ 760 if (state->start > start) { 761 u64 this_end; 762 if (end < last_start) 763 this_end = end; 764 else 765 this_end = last_start -1; 766 err = insert_state(tree, prealloc, start, this_end, 767 bits); 768 prealloc = NULL; 769 BUG_ON(err == -EEXIST); 770 if (err) 771 goto out; 772 start = this_end + 1; 773 goto search_again; 774 } 775 /* 776 * | ---- desired range ---- | 777 * | state | 778 * We need to split the extent, and set the bit 779 * on the first half 780 */ 781 if (state->start <= end && state->end > end) { 782 set = state->state & bits; 783 if (exclusive && set) { 784 *failed_start = start; 785 err = -EEXIST; 786 goto out; 787 } 788 err = split_state(tree, state, prealloc, end + 1); 789 BUG_ON(err == -EEXIST); 790 791 prealloc->state |= bits; 792 merge_state(tree, prealloc); 793 prealloc = NULL; 794 goto out; 795 } 796 797 goto search_again; 798 799 out: 800 write_unlock_irqrestore(&tree->lock, flags); 801 if (prealloc) 802 free_extent_state(prealloc); 803 804 return err; 805 806 search_again: 807 if (start > end) 808 goto out; 809 write_unlock_irqrestore(&tree->lock, flags); 810 if (mask & __GFP_WAIT) 811 cond_resched(); 812 goto again; 813 } 814 EXPORT_SYMBOL(set_extent_bit); 815 816 /* wrappers around set/clear extent bit */ 817 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 818 gfp_t mask) 819 { 820 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, 821 mask); 822 } 823 EXPORT_SYMBOL(set_extent_dirty); 824 825 int set_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 826 int bits, gfp_t mask) 827 { 828 return set_extent_bit(tree, start, end, bits, 0, NULL, 829 mask); 830 } 831 EXPORT_SYMBOL(set_extent_bits); 832 833 int clear_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 834 int bits, gfp_t mask) 835 { 836 return clear_extent_bit(tree, start, end, bits, 0, 0, mask); 837 } 838 EXPORT_SYMBOL(clear_extent_bits); 839 840 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end, 841 gfp_t mask) 842 { 843 return set_extent_bit(tree, start, end, 844 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL, 845 mask); 846 } 847 EXPORT_SYMBOL(set_extent_delalloc); 848 849 int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 850 gfp_t mask) 851 { 852 return clear_extent_bit(tree, start, end, 853 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask); 854 } 855 EXPORT_SYMBOL(clear_extent_dirty); 856 857 int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 858 gfp_t mask) 859 { 860 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, 861 mask); 862 } 863 EXPORT_SYMBOL(set_extent_new); 864 865 int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 866 gfp_t mask) 867 { 868 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask); 869 } 870 EXPORT_SYMBOL(clear_extent_new); 871 872 int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 873 gfp_t mask) 874 { 875 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL, 876 mask); 877 } 878 EXPORT_SYMBOL(set_extent_uptodate); 879 880 int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 881 gfp_t mask) 882 { 883 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask); 884 } 885 EXPORT_SYMBOL(clear_extent_uptodate); 886 887 int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 888 gfp_t mask) 889 { 890 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK, 891 0, NULL, mask); 892 } 893 EXPORT_SYMBOL(set_extent_writeback); 894 895 int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 896 gfp_t mask) 897 { 898 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask); 899 } 900 EXPORT_SYMBOL(clear_extent_writeback); 901 902 int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end) 903 { 904 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK); 905 } 906 EXPORT_SYMBOL(wait_on_extent_writeback); 907 908 /* 909 * locks a range in ascending order, waiting for any locked regions 910 * it hits on the way. [start,end] are inclusive, and this will sleep. 911 */ 912 int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask) 913 { 914 int err; 915 u64 failed_start; 916 while (1) { 917 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 918 &failed_start, mask); 919 if (err == -EEXIST && (mask & __GFP_WAIT)) { 920 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); 921 start = failed_start; 922 } else { 923 break; 924 } 925 WARN_ON(start > end); 926 } 927 return err; 928 } 929 EXPORT_SYMBOL(lock_extent); 930 931 int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, 932 gfp_t mask) 933 { 934 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask); 935 } 936 EXPORT_SYMBOL(unlock_extent); 937 938 /* 939 * helper function to set pages and extents in the tree dirty 940 */ 941 int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end) 942 { 943 unsigned long index = start >> PAGE_CACHE_SHIFT; 944 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 945 struct page *page; 946 947 while (index <= end_index) { 948 page = find_get_page(tree->mapping, index); 949 BUG_ON(!page); 950 __set_page_dirty_nobuffers(page); 951 page_cache_release(page); 952 index++; 953 } 954 set_extent_dirty(tree, start, end, GFP_NOFS); 955 return 0; 956 } 957 EXPORT_SYMBOL(set_range_dirty); 958 959 /* 960 * helper function to set both pages and extents in the tree writeback 961 */ 962 int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end) 963 { 964 unsigned long index = start >> PAGE_CACHE_SHIFT; 965 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 966 struct page *page; 967 968 while (index <= end_index) { 969 page = find_get_page(tree->mapping, index); 970 BUG_ON(!page); 971 set_page_writeback(page); 972 page_cache_release(page); 973 index++; 974 } 975 set_extent_writeback(tree, start, end, GFP_NOFS); 976 return 0; 977 } 978 EXPORT_SYMBOL(set_range_writeback); 979 980 int find_first_extent_bit(struct extent_map_tree *tree, u64 start, 981 u64 *start_ret, u64 *end_ret, int bits) 982 { 983 struct rb_node *node; 984 struct extent_state *state; 985 int ret = 1; 986 987 read_lock_irq(&tree->lock); 988 /* 989 * this search will find all the extents that end after 990 * our range starts. 991 */ 992 node = tree_search(&tree->state, start); 993 if (!node || IS_ERR(node)) { 994 goto out; 995 } 996 997 while(1) { 998 state = rb_entry(node, struct extent_state, rb_node); 999 if (state->end >= start && (state->state & bits)) { 1000 *start_ret = state->start; 1001 *end_ret = state->end; 1002 ret = 0; 1003 break; 1004 } 1005 node = rb_next(node); 1006 if (!node) 1007 break; 1008 } 1009 out: 1010 read_unlock_irq(&tree->lock); 1011 return ret; 1012 } 1013 EXPORT_SYMBOL(find_first_extent_bit); 1014 1015 u64 find_lock_delalloc_range(struct extent_map_tree *tree, 1016 u64 start, u64 lock_start, u64 *end, u64 max_bytes) 1017 { 1018 struct rb_node *node; 1019 struct extent_state *state; 1020 u64 cur_start = start; 1021 u64 found = 0; 1022 u64 total_bytes = 0; 1023 1024 write_lock_irq(&tree->lock); 1025 /* 1026 * this search will find all the extents that end after 1027 * our range starts. 1028 */ 1029 search_again: 1030 node = tree_search(&tree->state, cur_start); 1031 if (!node || IS_ERR(node)) { 1032 goto out; 1033 } 1034 1035 while(1) { 1036 state = rb_entry(node, struct extent_state, rb_node); 1037 if (state->start != cur_start) { 1038 goto out; 1039 } 1040 if (!(state->state & EXTENT_DELALLOC)) { 1041 goto out; 1042 } 1043 if (state->start >= lock_start) { 1044 if (state->state & EXTENT_LOCKED) { 1045 DEFINE_WAIT(wait); 1046 atomic_inc(&state->refs); 1047 prepare_to_wait(&state->wq, &wait, 1048 TASK_UNINTERRUPTIBLE); 1049 write_unlock_irq(&tree->lock); 1050 schedule(); 1051 write_lock_irq(&tree->lock); 1052 finish_wait(&state->wq, &wait); 1053 free_extent_state(state); 1054 goto search_again; 1055 } 1056 state->state |= EXTENT_LOCKED; 1057 } 1058 found++; 1059 *end = state->end; 1060 cur_start = state->end + 1; 1061 node = rb_next(node); 1062 if (!node) 1063 break; 1064 total_bytes += state->end - state->start + 1; 1065 if (total_bytes >= max_bytes) 1066 break; 1067 } 1068 out: 1069 write_unlock_irq(&tree->lock); 1070 return found; 1071 } 1072 1073 /* 1074 * helper function to lock both pages and extents in the tree. 1075 * pages must be locked first. 1076 */ 1077 int lock_range(struct extent_map_tree *tree, u64 start, u64 end) 1078 { 1079 unsigned long index = start >> PAGE_CACHE_SHIFT; 1080 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1081 struct page *page; 1082 int err; 1083 1084 while (index <= end_index) { 1085 page = grab_cache_page(tree->mapping, index); 1086 if (!page) { 1087 err = -ENOMEM; 1088 goto failed; 1089 } 1090 if (IS_ERR(page)) { 1091 err = PTR_ERR(page); 1092 goto failed; 1093 } 1094 index++; 1095 } 1096 lock_extent(tree, start, end, GFP_NOFS); 1097 return 0; 1098 1099 failed: 1100 /* 1101 * we failed above in getting the page at 'index', so we undo here 1102 * up to but not including the page at 'index' 1103 */ 1104 end_index = index; 1105 index = start >> PAGE_CACHE_SHIFT; 1106 while (index < end_index) { 1107 page = find_get_page(tree->mapping, index); 1108 unlock_page(page); 1109 page_cache_release(page); 1110 index++; 1111 } 1112 return err; 1113 } 1114 EXPORT_SYMBOL(lock_range); 1115 1116 /* 1117 * helper function to unlock both pages and extents in the tree. 1118 */ 1119 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end) 1120 { 1121 unsigned long index = start >> PAGE_CACHE_SHIFT; 1122 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1123 struct page *page; 1124 1125 while (index <= end_index) { 1126 page = find_get_page(tree->mapping, index); 1127 unlock_page(page); 1128 page_cache_release(page); 1129 index++; 1130 } 1131 unlock_extent(tree, start, end, GFP_NOFS); 1132 return 0; 1133 } 1134 EXPORT_SYMBOL(unlock_range); 1135 1136 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private) 1137 { 1138 struct rb_node *node; 1139 struct extent_state *state; 1140 int ret = 0; 1141 1142 write_lock_irq(&tree->lock); 1143 /* 1144 * this search will find all the extents that end after 1145 * our range starts. 1146 */ 1147 node = tree_search(&tree->state, start); 1148 if (!node || IS_ERR(node)) { 1149 ret = -ENOENT; 1150 goto out; 1151 } 1152 state = rb_entry(node, struct extent_state, rb_node); 1153 if (state->start != start) { 1154 ret = -ENOENT; 1155 goto out; 1156 } 1157 state->private = private; 1158 out: 1159 write_unlock_irq(&tree->lock); 1160 return ret; 1161 } 1162 1163 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private) 1164 { 1165 struct rb_node *node; 1166 struct extent_state *state; 1167 int ret = 0; 1168 1169 read_lock_irq(&tree->lock); 1170 /* 1171 * this search will find all the extents that end after 1172 * our range starts. 1173 */ 1174 node = tree_search(&tree->state, start); 1175 if (!node || IS_ERR(node)) { 1176 ret = -ENOENT; 1177 goto out; 1178 } 1179 state = rb_entry(node, struct extent_state, rb_node); 1180 if (state->start != start) { 1181 ret = -ENOENT; 1182 goto out; 1183 } 1184 *private = state->private; 1185 out: 1186 read_unlock_irq(&tree->lock); 1187 return ret; 1188 } 1189 1190 /* 1191 * searches a range in the state tree for a given mask. 1192 * If 'filled' == 1, this returns 1 only if ever extent in the tree 1193 * has the bits set. Otherwise, 1 is returned if any bit in the 1194 * range is found set. 1195 */ 1196 int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end, 1197 int bits, int filled) 1198 { 1199 struct extent_state *state = NULL; 1200 struct rb_node *node; 1201 int bitset = 0; 1202 1203 read_lock_irq(&tree->lock); 1204 node = tree_search(&tree->state, start); 1205 while (node && start <= end) { 1206 state = rb_entry(node, struct extent_state, rb_node); 1207 if (state->start > end) 1208 break; 1209 1210 if (filled && state->start > start) { 1211 bitset = 0; 1212 break; 1213 } 1214 if (state->state & bits) { 1215 bitset = 1; 1216 if (!filled) 1217 break; 1218 } else if (filled) { 1219 bitset = 0; 1220 break; 1221 } 1222 start = state->end + 1; 1223 if (start > end) 1224 break; 1225 node = rb_next(node); 1226 } 1227 read_unlock_irq(&tree->lock); 1228 return bitset; 1229 } 1230 EXPORT_SYMBOL(test_range_bit); 1231 1232 /* 1233 * helper function to set a given page up to date if all the 1234 * extents in the tree for that page are up to date 1235 */ 1236 static int check_page_uptodate(struct extent_map_tree *tree, 1237 struct page *page) 1238 { 1239 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1240 u64 end = start + PAGE_CACHE_SIZE - 1; 1241 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1)) 1242 SetPageUptodate(page); 1243 return 0; 1244 } 1245 1246 /* 1247 * helper function to unlock a page if all the extents in the tree 1248 * for that page are unlocked 1249 */ 1250 static int check_page_locked(struct extent_map_tree *tree, 1251 struct page *page) 1252 { 1253 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1254 u64 end = start + PAGE_CACHE_SIZE - 1; 1255 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0)) 1256 unlock_page(page); 1257 return 0; 1258 } 1259 1260 /* 1261 * helper function to end page writeback if all the extents 1262 * in the tree for that page are done with writeback 1263 */ 1264 static int check_page_writeback(struct extent_map_tree *tree, 1265 struct page *page) 1266 { 1267 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1268 u64 end = start + PAGE_CACHE_SIZE - 1; 1269 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0)) 1270 end_page_writeback(page); 1271 return 0; 1272 } 1273 1274 /* lots and lots of room for performance fixes in the end_bio funcs */ 1275 1276 /* 1277 * after a writepage IO is done, we need to: 1278 * clear the uptodate bits on error 1279 * clear the writeback bits in the extent tree for this IO 1280 * end_page_writeback if the page has no more pending IO 1281 * 1282 * Scheduling is not allowed, so the extent state tree is expected 1283 * to have one and only one object corresponding to this IO. 1284 */ 1285 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1286 static void end_bio_extent_writepage(struct bio *bio, int err) 1287 #else 1288 static int end_bio_extent_writepage(struct bio *bio, 1289 unsigned int bytes_done, int err) 1290 #endif 1291 { 1292 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1293 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1294 struct extent_map_tree *tree = bio->bi_private; 1295 u64 start; 1296 u64 end; 1297 int whole_page; 1298 1299 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1300 if (bio->bi_size) 1301 return 1; 1302 #endif 1303 1304 do { 1305 struct page *page = bvec->bv_page; 1306 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1307 bvec->bv_offset; 1308 end = start + bvec->bv_len - 1; 1309 1310 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1311 whole_page = 1; 1312 else 1313 whole_page = 0; 1314 1315 if (--bvec >= bio->bi_io_vec) 1316 prefetchw(&bvec->bv_page->flags); 1317 1318 if (!uptodate) { 1319 clear_extent_uptodate(tree, start, end, GFP_ATOMIC); 1320 ClearPageUptodate(page); 1321 SetPageError(page); 1322 } 1323 clear_extent_writeback(tree, start, end, GFP_ATOMIC); 1324 1325 if (whole_page) 1326 end_page_writeback(page); 1327 else 1328 check_page_writeback(tree, page); 1329 if (tree->ops && tree->ops->writepage_end_io_hook) 1330 tree->ops->writepage_end_io_hook(page, start, end); 1331 } while (bvec >= bio->bi_io_vec); 1332 1333 bio_put(bio); 1334 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1335 return 0; 1336 #endif 1337 } 1338 1339 /* 1340 * after a readpage IO is done, we need to: 1341 * clear the uptodate bits on error 1342 * set the uptodate bits if things worked 1343 * set the page up to date if all extents in the tree are uptodate 1344 * clear the lock bit in the extent tree 1345 * unlock the page if there are no other extents locked for it 1346 * 1347 * Scheduling is not allowed, so the extent state tree is expected 1348 * to have one and only one object corresponding to this IO. 1349 */ 1350 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1351 static void end_bio_extent_readpage(struct bio *bio, int err) 1352 #else 1353 static int end_bio_extent_readpage(struct bio *bio, 1354 unsigned int bytes_done, int err) 1355 #endif 1356 { 1357 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1358 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1359 struct extent_map_tree *tree = bio->bi_private; 1360 u64 start; 1361 u64 end; 1362 int whole_page; 1363 int ret; 1364 1365 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1366 if (bio->bi_size) 1367 return 1; 1368 #endif 1369 1370 do { 1371 struct page *page = bvec->bv_page; 1372 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1373 bvec->bv_offset; 1374 end = start + bvec->bv_len - 1; 1375 1376 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1377 whole_page = 1; 1378 else 1379 whole_page = 0; 1380 1381 if (--bvec >= bio->bi_io_vec) 1382 prefetchw(&bvec->bv_page->flags); 1383 1384 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { 1385 ret = tree->ops->readpage_end_io_hook(page, start, end); 1386 if (ret) 1387 uptodate = 0; 1388 } 1389 if (uptodate) { 1390 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1391 if (whole_page) 1392 SetPageUptodate(page); 1393 else 1394 check_page_uptodate(tree, page); 1395 } else { 1396 ClearPageUptodate(page); 1397 SetPageError(page); 1398 } 1399 1400 unlock_extent(tree, start, end, GFP_ATOMIC); 1401 1402 if (whole_page) 1403 unlock_page(page); 1404 else 1405 check_page_locked(tree, page); 1406 } while (bvec >= bio->bi_io_vec); 1407 1408 bio_put(bio); 1409 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1410 return 0; 1411 #endif 1412 } 1413 1414 /* 1415 * IO done from prepare_write is pretty simple, we just unlock 1416 * the structs in the extent tree when done, and set the uptodate bits 1417 * as appropriate. 1418 */ 1419 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1420 static void end_bio_extent_preparewrite(struct bio *bio, int err) 1421 #else 1422 static int end_bio_extent_preparewrite(struct bio *bio, 1423 unsigned int bytes_done, int err) 1424 #endif 1425 { 1426 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1427 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1428 struct extent_map_tree *tree = bio->bi_private; 1429 u64 start; 1430 u64 end; 1431 1432 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1433 if (bio->bi_size) 1434 return 1; 1435 #endif 1436 1437 do { 1438 struct page *page = bvec->bv_page; 1439 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1440 bvec->bv_offset; 1441 end = start + bvec->bv_len - 1; 1442 1443 if (--bvec >= bio->bi_io_vec) 1444 prefetchw(&bvec->bv_page->flags); 1445 1446 if (uptodate) { 1447 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1448 } else { 1449 ClearPageUptodate(page); 1450 SetPageError(page); 1451 } 1452 1453 unlock_extent(tree, start, end, GFP_ATOMIC); 1454 1455 } while (bvec >= bio->bi_io_vec); 1456 1457 bio_put(bio); 1458 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1459 return 0; 1460 #endif 1461 } 1462 1463 static int submit_extent_page(int rw, struct extent_map_tree *tree, 1464 struct page *page, sector_t sector, 1465 size_t size, unsigned long offset, 1466 struct block_device *bdev, 1467 bio_end_io_t end_io_func) 1468 { 1469 struct bio *bio; 1470 int ret = 0; 1471 1472 bio = bio_alloc(GFP_NOIO, 1); 1473 1474 bio->bi_sector = sector; 1475 bio->bi_bdev = bdev; 1476 bio->bi_io_vec[0].bv_page = page; 1477 bio->bi_io_vec[0].bv_len = size; 1478 bio->bi_io_vec[0].bv_offset = offset; 1479 1480 bio->bi_vcnt = 1; 1481 bio->bi_idx = 0; 1482 bio->bi_size = size; 1483 1484 bio->bi_end_io = end_io_func; 1485 bio->bi_private = tree; 1486 1487 bio_get(bio); 1488 submit_bio(rw, bio); 1489 1490 if (bio_flagged(bio, BIO_EOPNOTSUPP)) 1491 ret = -EOPNOTSUPP; 1492 1493 bio_put(bio); 1494 return ret; 1495 } 1496 1497 void set_page_extent_mapped(struct page *page) 1498 { 1499 if (!PagePrivate(page)) { 1500 SetPagePrivate(page); 1501 WARN_ON(!page->mapping->a_ops->invalidatepage); 1502 set_page_private(page, EXTENT_PAGE_PRIVATE); 1503 page_cache_get(page); 1504 } 1505 } 1506 1507 /* 1508 * basic readpage implementation. Locked extent state structs are inserted 1509 * into the tree that are removed when the IO is done (by the end_io 1510 * handlers) 1511 */ 1512 int extent_read_full_page(struct extent_map_tree *tree, struct page *page, 1513 get_extent_t *get_extent) 1514 { 1515 struct inode *inode = page->mapping->host; 1516 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1517 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1518 u64 end; 1519 u64 cur = start; 1520 u64 extent_offset; 1521 u64 last_byte = i_size_read(inode); 1522 u64 block_start; 1523 u64 cur_end; 1524 sector_t sector; 1525 struct extent_map *em; 1526 struct block_device *bdev; 1527 int ret; 1528 int nr = 0; 1529 size_t page_offset = 0; 1530 size_t iosize; 1531 size_t blocksize = inode->i_sb->s_blocksize; 1532 1533 set_page_extent_mapped(page); 1534 1535 end = page_end; 1536 lock_extent(tree, start, end, GFP_NOFS); 1537 1538 while (cur <= end) { 1539 if (cur >= last_byte) { 1540 iosize = PAGE_CACHE_SIZE - page_offset; 1541 zero_user_page(page, page_offset, iosize, KM_USER0); 1542 set_extent_uptodate(tree, cur, cur + iosize - 1, 1543 GFP_NOFS); 1544 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1545 break; 1546 } 1547 em = get_extent(inode, page, page_offset, cur, end, 0); 1548 if (IS_ERR(em) || !em) { 1549 SetPageError(page); 1550 unlock_extent(tree, cur, end, GFP_NOFS); 1551 break; 1552 } 1553 1554 extent_offset = cur - em->start; 1555 BUG_ON(em->end < cur); 1556 BUG_ON(end < cur); 1557 1558 iosize = min(em->end - cur, end - cur) + 1; 1559 cur_end = min(em->end, end); 1560 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1561 sector = (em->block_start + extent_offset) >> 9; 1562 bdev = em->bdev; 1563 block_start = em->block_start; 1564 free_extent_map(em); 1565 em = NULL; 1566 1567 /* we've found a hole, just zero and go on */ 1568 if (block_start == EXTENT_MAP_HOLE) { 1569 zero_user_page(page, page_offset, iosize, KM_USER0); 1570 set_extent_uptodate(tree, cur, cur + iosize - 1, 1571 GFP_NOFS); 1572 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1573 cur = cur + iosize; 1574 page_offset += iosize; 1575 continue; 1576 } 1577 /* the get_extent function already copied into the page */ 1578 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { 1579 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1580 cur = cur + iosize; 1581 page_offset += iosize; 1582 continue; 1583 } 1584 1585 ret = 0; 1586 if (tree->ops && tree->ops->readpage_io_hook) { 1587 ret = tree->ops->readpage_io_hook(page, cur, 1588 cur + iosize - 1); 1589 } 1590 if (!ret) { 1591 ret = submit_extent_page(READ, tree, page, 1592 sector, iosize, page_offset, 1593 bdev, end_bio_extent_readpage); 1594 } 1595 if (ret) 1596 SetPageError(page); 1597 cur = cur + iosize; 1598 page_offset += iosize; 1599 nr++; 1600 } 1601 if (!nr) { 1602 if (!PageError(page)) 1603 SetPageUptodate(page); 1604 unlock_page(page); 1605 } 1606 return 0; 1607 } 1608 EXPORT_SYMBOL(extent_read_full_page); 1609 1610 /* 1611 * the writepage semantics are similar to regular writepage. extent 1612 * records are inserted to lock ranges in the tree, and as dirty areas 1613 * are found, they are marked writeback. Then the lock bits are removed 1614 * and the end_io handler clears the writeback ranges 1615 */ 1616 int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 1617 get_extent_t *get_extent, 1618 struct writeback_control *wbc) 1619 { 1620 struct inode *inode = page->mapping->host; 1621 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1622 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1623 u64 end; 1624 u64 cur = start; 1625 u64 extent_offset; 1626 u64 last_byte = i_size_read(inode); 1627 u64 block_start; 1628 u64 iosize; 1629 sector_t sector; 1630 struct extent_map *em; 1631 struct block_device *bdev; 1632 int ret; 1633 int nr = 0; 1634 size_t page_offset = 0; 1635 size_t blocksize; 1636 loff_t i_size = i_size_read(inode); 1637 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; 1638 u64 nr_delalloc; 1639 u64 delalloc_end; 1640 1641 WARN_ON(!PageLocked(page)); 1642 if (page->index > end_index) { 1643 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1644 unlock_page(page); 1645 return 0; 1646 } 1647 1648 if (page->index == end_index) { 1649 size_t offset = i_size & (PAGE_CACHE_SIZE - 1); 1650 zero_user_page(page, offset, 1651 PAGE_CACHE_SIZE - offset, KM_USER0); 1652 } 1653 1654 set_page_extent_mapped(page); 1655 1656 lock_extent(tree, start, page_end, GFP_NOFS); 1657 nr_delalloc = find_lock_delalloc_range(tree, start, page_end + 1, 1658 &delalloc_end, 1659 128 * 1024 * 1024); 1660 if (nr_delalloc) { 1661 tree->ops->fill_delalloc(inode, start, delalloc_end); 1662 if (delalloc_end >= page_end + 1) { 1663 clear_extent_bit(tree, page_end + 1, delalloc_end, 1664 EXTENT_LOCKED | EXTENT_DELALLOC, 1665 1, 0, GFP_NOFS); 1666 } 1667 clear_extent_bit(tree, start, page_end, EXTENT_DELALLOC, 1668 0, 0, GFP_NOFS); 1669 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1670 printk("found delalloc bits after clear extent_bit\n"); 1671 } 1672 } else if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1673 printk("found delalloc bits after find_delalloc_range returns 0\n"); 1674 } 1675 1676 end = page_end; 1677 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1678 printk("found delalloc bits after lock_extent\n"); 1679 } 1680 1681 if (last_byte <= start) { 1682 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1683 goto done; 1684 } 1685 1686 set_extent_uptodate(tree, start, page_end, GFP_NOFS); 1687 blocksize = inode->i_sb->s_blocksize; 1688 1689 while (cur <= end) { 1690 if (cur >= last_byte) { 1691 clear_extent_dirty(tree, cur, page_end, GFP_NOFS); 1692 break; 1693 } 1694 em = get_extent(inode, page, page_offset, cur, end, 1); 1695 if (IS_ERR(em) || !em) { 1696 SetPageError(page); 1697 break; 1698 } 1699 1700 extent_offset = cur - em->start; 1701 BUG_ON(em->end < cur); 1702 BUG_ON(end < cur); 1703 iosize = min(em->end - cur, end - cur) + 1; 1704 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1705 sector = (em->block_start + extent_offset) >> 9; 1706 bdev = em->bdev; 1707 block_start = em->block_start; 1708 free_extent_map(em); 1709 em = NULL; 1710 1711 if (block_start == EXTENT_MAP_HOLE || 1712 block_start == EXTENT_MAP_INLINE) { 1713 clear_extent_dirty(tree, cur, 1714 cur + iosize - 1, GFP_NOFS); 1715 cur = cur + iosize; 1716 page_offset += iosize; 1717 continue; 1718 } 1719 1720 /* leave this out until we have a page_mkwrite call */ 1721 if (0 && !test_range_bit(tree, cur, cur + iosize - 1, 1722 EXTENT_DIRTY, 0)) { 1723 cur = cur + iosize; 1724 page_offset += iosize; 1725 continue; 1726 } 1727 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); 1728 if (tree->ops && tree->ops->writepage_io_hook) { 1729 ret = tree->ops->writepage_io_hook(page, cur, 1730 cur + iosize - 1); 1731 } else { 1732 ret = 0; 1733 } 1734 if (ret) 1735 SetPageError(page); 1736 else { 1737 set_range_writeback(tree, cur, cur + iosize - 1); 1738 ret = submit_extent_page(WRITE, tree, page, sector, 1739 iosize, page_offset, bdev, 1740 end_bio_extent_writepage); 1741 if (ret) 1742 SetPageError(page); 1743 } 1744 cur = cur + iosize; 1745 page_offset += iosize; 1746 nr++; 1747 } 1748 done: 1749 unlock_extent(tree, start, page_end, GFP_NOFS); 1750 unlock_page(page); 1751 return 0; 1752 } 1753 EXPORT_SYMBOL(extent_write_full_page); 1754 1755 /* 1756 * basic invalidatepage code, this waits on any locked or writeback 1757 * ranges corresponding to the page, and then deletes any extent state 1758 * records from the tree 1759 */ 1760 int extent_invalidatepage(struct extent_map_tree *tree, 1761 struct page *page, unsigned long offset) 1762 { 1763 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT); 1764 u64 end = start + PAGE_CACHE_SIZE - 1; 1765 size_t blocksize = page->mapping->host->i_sb->s_blocksize; 1766 1767 start += (offset + blocksize -1) & ~(blocksize - 1); 1768 if (start > end) 1769 return 0; 1770 1771 lock_extent(tree, start, end, GFP_NOFS); 1772 wait_on_extent_writeback(tree, start, end); 1773 clear_extent_bit(tree, start, end, 1774 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, 1775 1, 1, GFP_NOFS); 1776 return 0; 1777 } 1778 EXPORT_SYMBOL(extent_invalidatepage); 1779 1780 /* 1781 * simple commit_write call, set_range_dirty is used to mark both 1782 * the pages and the extent records as dirty 1783 */ 1784 int extent_commit_write(struct extent_map_tree *tree, 1785 struct inode *inode, struct page *page, 1786 unsigned from, unsigned to) 1787 { 1788 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; 1789 1790 set_page_extent_mapped(page); 1791 set_page_dirty(page); 1792 1793 if (pos > inode->i_size) { 1794 i_size_write(inode, pos); 1795 mark_inode_dirty(inode); 1796 } 1797 return 0; 1798 } 1799 EXPORT_SYMBOL(extent_commit_write); 1800 1801 int extent_prepare_write(struct extent_map_tree *tree, 1802 struct inode *inode, struct page *page, 1803 unsigned from, unsigned to, get_extent_t *get_extent) 1804 { 1805 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 1806 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 1807 u64 block_start; 1808 u64 orig_block_start; 1809 u64 block_end; 1810 u64 cur_end; 1811 struct extent_map *em; 1812 unsigned blocksize = 1 << inode->i_blkbits; 1813 size_t page_offset = 0; 1814 size_t block_off_start; 1815 size_t block_off_end; 1816 int err = 0; 1817 int iocount = 0; 1818 int ret = 0; 1819 int isnew; 1820 1821 set_page_extent_mapped(page); 1822 1823 block_start = (page_start + from) & ~((u64)blocksize - 1); 1824 block_end = (page_start + to - 1) | (blocksize - 1); 1825 orig_block_start = block_start; 1826 1827 lock_extent(tree, page_start, page_end, GFP_NOFS); 1828 while(block_start <= block_end) { 1829 em = get_extent(inode, page, page_offset, block_start, 1830 block_end, 1); 1831 if (IS_ERR(em) || !em) { 1832 goto err; 1833 } 1834 cur_end = min(block_end, em->end); 1835 block_off_start = block_start & (PAGE_CACHE_SIZE - 1); 1836 block_off_end = block_off_start + blocksize; 1837 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); 1838 1839 if (!PageUptodate(page) && isnew && 1840 (block_off_end > to || block_off_start < from)) { 1841 void *kaddr; 1842 1843 kaddr = kmap_atomic(page, KM_USER0); 1844 if (block_off_end > to) 1845 memset(kaddr + to, 0, block_off_end - to); 1846 if (block_off_start < from) 1847 memset(kaddr + block_off_start, 0, 1848 from - block_off_start); 1849 flush_dcache_page(page); 1850 kunmap_atomic(kaddr, KM_USER0); 1851 } 1852 if (!isnew && !PageUptodate(page) && 1853 (block_off_end > to || block_off_start < from) && 1854 !test_range_bit(tree, block_start, cur_end, 1855 EXTENT_UPTODATE, 1)) { 1856 u64 sector; 1857 u64 extent_offset = block_start - em->start; 1858 size_t iosize; 1859 sector = (em->block_start + extent_offset) >> 9; 1860 iosize = (cur_end - block_start + blocksize - 1) & 1861 ~((u64)blocksize - 1); 1862 /* 1863 * we've already got the extent locked, but we 1864 * need to split the state such that our end_bio 1865 * handler can clear the lock. 1866 */ 1867 set_extent_bit(tree, block_start, 1868 block_start + iosize - 1, 1869 EXTENT_LOCKED, 0, NULL, GFP_NOFS); 1870 ret = submit_extent_page(READ, tree, page, 1871 sector, iosize, page_offset, em->bdev, 1872 end_bio_extent_preparewrite); 1873 iocount++; 1874 block_start = block_start + iosize; 1875 } else { 1876 set_extent_uptodate(tree, block_start, cur_end, 1877 GFP_NOFS); 1878 unlock_extent(tree, block_start, cur_end, GFP_NOFS); 1879 block_start = cur_end + 1; 1880 } 1881 page_offset = block_start & (PAGE_CACHE_SIZE - 1); 1882 free_extent_map(em); 1883 } 1884 if (iocount) { 1885 wait_extent_bit(tree, orig_block_start, 1886 block_end, EXTENT_LOCKED); 1887 } 1888 check_page_uptodate(tree, page); 1889 err: 1890 /* FIXME, zero out newly allocated blocks on error */ 1891 return err; 1892 } 1893 EXPORT_SYMBOL(extent_prepare_write); 1894 1895 /* 1896 * a helper for releasepage. As long as there are no locked extents 1897 * in the range corresponding to the page, both state records and extent 1898 * map records are removed 1899 */ 1900 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) 1901 { 1902 struct extent_map *em; 1903 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1904 u64 end = start + PAGE_CACHE_SIZE - 1; 1905 u64 orig_start = start; 1906 int ret = 1; 1907 1908 while (start <= end) { 1909 em = lookup_extent_mapping(tree, start, end); 1910 if (!em || IS_ERR(em)) 1911 break; 1912 if (!test_range_bit(tree, em->start, em->end, 1913 EXTENT_LOCKED, 0)) { 1914 remove_extent_mapping(tree, em); 1915 /* once for the rb tree */ 1916 free_extent_map(em); 1917 } 1918 start = em->end + 1; 1919 /* once for us */ 1920 free_extent_map(em); 1921 } 1922 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) 1923 ret = 0; 1924 else 1925 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, 1926 1, 1, GFP_NOFS); 1927 return ret; 1928 } 1929 EXPORT_SYMBOL(try_release_extent_mapping); 1930 1931 sector_t extent_bmap(struct address_space *mapping, sector_t iblock, 1932 get_extent_t *get_extent) 1933 { 1934 struct inode *inode = mapping->host; 1935 u64 start = iblock << inode->i_blkbits; 1936 u64 end = start + (1 << inode->i_blkbits) - 1; 1937 sector_t sector = 0; 1938 struct extent_map *em; 1939 1940 em = get_extent(inode, NULL, 0, start, end, 0); 1941 if (!em || IS_ERR(em)) 1942 return 0; 1943 1944 if (em->block_start == EXTENT_MAP_INLINE || 1945 em->block_start == EXTENT_MAP_HOLE) 1946 goto out; 1947 1948 sector = (em->block_start + start - em->start) >> inode->i_blkbits; 1949 out: 1950 free_extent_map(em); 1951 return sector; 1952 } 1953 1954 static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb) 1955 { 1956 if (list_empty(&eb->lru)) { 1957 extent_buffer_get(eb); 1958 list_add(&eb->lru, &tree->buffer_lru); 1959 tree->lru_size++; 1960 if (tree->lru_size >= BUFFER_LRU_MAX) { 1961 struct extent_buffer *rm; 1962 rm = list_entry(tree->buffer_lru.prev, 1963 struct extent_buffer, lru); 1964 tree->lru_size--; 1965 list_del(&rm->lru); 1966 free_extent_buffer(rm); 1967 } 1968 } else 1969 list_move(&eb->lru, &tree->buffer_lru); 1970 return 0; 1971 } 1972 static struct extent_buffer *find_lru(struct extent_map_tree *tree, 1973 u64 start, unsigned long len) 1974 { 1975 struct list_head *lru = &tree->buffer_lru; 1976 struct list_head *cur = lru->next; 1977 struct extent_buffer *eb; 1978 1979 if (list_empty(lru)) 1980 return NULL; 1981 1982 do { 1983 eb = list_entry(cur, struct extent_buffer, lru); 1984 if (eb->start == start && eb->len == len) { 1985 extent_buffer_get(eb); 1986 return eb; 1987 } 1988 cur = cur->next; 1989 } while (cur != lru); 1990 return NULL; 1991 } 1992 1993 static inline unsigned long num_extent_pages(u64 start, u64 len) 1994 { 1995 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - 1996 (start >> PAGE_CACHE_SHIFT); 1997 } 1998 1999 static inline struct page *extent_buffer_page(struct extent_buffer *eb, 2000 unsigned long i) 2001 { 2002 struct page *p; 2003 struct address_space *mapping; 2004 2005 if (i == 0) 2006 return eb->first_page; 2007 i += eb->start >> PAGE_CACHE_SHIFT; 2008 mapping = eb->first_page->mapping; 2009 read_lock_irq(&mapping->tree_lock); 2010 p = radix_tree_lookup(&mapping->page_tree, i); 2011 read_unlock_irq(&mapping->tree_lock); 2012 return p; 2013 } 2014 2015 static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, 2016 u64 start, 2017 unsigned long len, 2018 gfp_t mask) 2019 { 2020 struct extent_buffer *eb = NULL; 2021 2022 spin_lock(&tree->lru_lock); 2023 eb = find_lru(tree, start, len); 2024 if (eb) { 2025 goto lru_add; 2026 } 2027 spin_unlock(&tree->lru_lock); 2028 2029 if (eb) { 2030 memset(eb, 0, sizeof(*eb)); 2031 } else { 2032 eb = kmem_cache_zalloc(extent_buffer_cache, mask); 2033 } 2034 INIT_LIST_HEAD(&eb->lru); 2035 eb->start = start; 2036 eb->len = len; 2037 atomic_set(&eb->refs, 1); 2038 2039 spin_lock(&tree->lru_lock); 2040 lru_add: 2041 add_lru(tree, eb); 2042 spin_unlock(&tree->lru_lock); 2043 return eb; 2044 } 2045 2046 static void __free_extent_buffer(struct extent_buffer *eb) 2047 { 2048 kmem_cache_free(extent_buffer_cache, eb); 2049 } 2050 2051 struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 2052 u64 start, unsigned long len, 2053 struct page *page0, 2054 gfp_t mask) 2055 { 2056 unsigned long num_pages = num_extent_pages(start, len); 2057 unsigned long i; 2058 unsigned long index = start >> PAGE_CACHE_SHIFT; 2059 struct extent_buffer *eb; 2060 struct page *p; 2061 struct address_space *mapping = tree->mapping; 2062 int uptodate = 1; 2063 2064 eb = __alloc_extent_buffer(tree, start, len, mask); 2065 if (!eb || IS_ERR(eb)) 2066 return NULL; 2067 2068 if (eb->flags & EXTENT_BUFFER_FILLED) 2069 return eb; 2070 2071 if (page0) { 2072 eb->first_page = page0; 2073 i = 1; 2074 index++; 2075 page_cache_get(page0); 2076 mark_page_accessed(page0); 2077 set_page_extent_mapped(page0); 2078 set_page_private(page0, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2079 len << 2); 2080 } else { 2081 i = 0; 2082 } 2083 for (; i < num_pages; i++, index++) { 2084 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM); 2085 if (!p) { 2086 WARN_ON(1); 2087 /* make sure the free only frees the pages we've 2088 * grabbed a reference on 2089 */ 2090 eb->len = i << PAGE_CACHE_SHIFT; 2091 eb->start &= ~((u64)PAGE_CACHE_SIZE - 1); 2092 goto fail; 2093 } 2094 set_page_extent_mapped(p); 2095 mark_page_accessed(p); 2096 if (i == 0) { 2097 eb->first_page = p; 2098 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2099 len << 2); 2100 } else { 2101 set_page_private(p, EXTENT_PAGE_PRIVATE); 2102 } 2103 if (!PageUptodate(p)) 2104 uptodate = 0; 2105 unlock_page(p); 2106 } 2107 if (uptodate) 2108 eb->flags |= EXTENT_UPTODATE; 2109 eb->flags |= EXTENT_BUFFER_FILLED; 2110 return eb; 2111 fail: 2112 free_extent_buffer(eb); 2113 return NULL; 2114 } 2115 EXPORT_SYMBOL(alloc_extent_buffer); 2116 2117 struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 2118 u64 start, unsigned long len, 2119 gfp_t mask) 2120 { 2121 unsigned long num_pages = num_extent_pages(start, len); 2122 unsigned long i; unsigned long index = start >> PAGE_CACHE_SHIFT; 2123 struct extent_buffer *eb; 2124 struct page *p; 2125 struct address_space *mapping = tree->mapping; 2126 int uptodate = 1; 2127 2128 eb = __alloc_extent_buffer(tree, start, len, mask); 2129 if (!eb || IS_ERR(eb)) 2130 return NULL; 2131 2132 if (eb->flags & EXTENT_BUFFER_FILLED) 2133 return eb; 2134 2135 for (i = 0; i < num_pages; i++, index++) { 2136 p = find_lock_page(mapping, index); 2137 if (!p) { 2138 /* make sure the free only frees the pages we've 2139 * grabbed a reference on 2140 */ 2141 eb->len = i << PAGE_CACHE_SHIFT; 2142 eb->start &= ~((u64)PAGE_CACHE_SIZE - 1); 2143 goto fail; 2144 } 2145 set_page_extent_mapped(p); 2146 mark_page_accessed(p); 2147 2148 if (i == 0) { 2149 eb->first_page = p; 2150 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2151 len << 2); 2152 } else { 2153 set_page_private(p, EXTENT_PAGE_PRIVATE); 2154 } 2155 2156 if (!PageUptodate(p)) 2157 uptodate = 0; 2158 unlock_page(p); 2159 } 2160 if (uptodate) 2161 eb->flags |= EXTENT_UPTODATE; 2162 eb->flags |= EXTENT_BUFFER_FILLED; 2163 return eb; 2164 fail: 2165 free_extent_buffer(eb); 2166 return NULL; 2167 } 2168 EXPORT_SYMBOL(find_extent_buffer); 2169 2170 void free_extent_buffer(struct extent_buffer *eb) 2171 { 2172 unsigned long i; 2173 unsigned long num_pages; 2174 2175 if (!eb) 2176 return; 2177 2178 if (!atomic_dec_and_test(&eb->refs)) 2179 return; 2180 2181 num_pages = num_extent_pages(eb->start, eb->len); 2182 2183 for (i = 0; i < num_pages; i++) { 2184 page_cache_release(extent_buffer_page(eb, i)); 2185 } 2186 __free_extent_buffer(eb); 2187 } 2188 EXPORT_SYMBOL(free_extent_buffer); 2189 2190 int clear_extent_buffer_dirty(struct extent_map_tree *tree, 2191 struct extent_buffer *eb) 2192 { 2193 int set; 2194 unsigned long i; 2195 unsigned long num_pages; 2196 struct page *page; 2197 2198 u64 start = eb->start; 2199 u64 end = start + eb->len - 1; 2200 2201 set = clear_extent_dirty(tree, start, end, GFP_NOFS); 2202 num_pages = num_extent_pages(eb->start, eb->len); 2203 2204 for (i = 0; i < num_pages; i++) { 2205 page = extent_buffer_page(eb, i); 2206 lock_page(page); 2207 /* 2208 * if we're on the last page or the first page and the 2209 * block isn't aligned on a page boundary, do extra checks 2210 * to make sure we don't clean page that is partially dirty 2211 */ 2212 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2213 ((i == num_pages - 1) && 2214 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2215 start = (u64)page->index << PAGE_CACHE_SHIFT; 2216 end = start + PAGE_CACHE_SIZE - 1; 2217 if (test_range_bit(tree, start, end, 2218 EXTENT_DIRTY, 0)) { 2219 unlock_page(page); 2220 continue; 2221 } 2222 } 2223 clear_page_dirty_for_io(page); 2224 unlock_page(page); 2225 } 2226 return 0; 2227 } 2228 EXPORT_SYMBOL(clear_extent_buffer_dirty); 2229 2230 int wait_on_extent_buffer_writeback(struct extent_map_tree *tree, 2231 struct extent_buffer *eb) 2232 { 2233 return wait_on_extent_writeback(tree, eb->start, 2234 eb->start + eb->len - 1); 2235 } 2236 EXPORT_SYMBOL(wait_on_extent_buffer_writeback); 2237 2238 int set_extent_buffer_dirty(struct extent_map_tree *tree, 2239 struct extent_buffer *eb) 2240 { 2241 unsigned long i; 2242 unsigned long num_pages; 2243 2244 num_pages = num_extent_pages(eb->start, eb->len); 2245 for (i = 0; i < num_pages; i++) { 2246 struct page *page = extent_buffer_page(eb, i); 2247 /* writepage may need to do something special for the 2248 * first page, we have to make sure page->private is 2249 * properly set. releasepage may drop page->private 2250 * on us if the page isn't already dirty. 2251 */ 2252 if (i == 0) { 2253 lock_page(page); 2254 set_page_private(page, 2255 EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2256 eb->len << 2); 2257 } 2258 __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); 2259 if (i == 0) 2260 unlock_page(page); 2261 } 2262 return set_extent_dirty(tree, eb->start, 2263 eb->start + eb->len - 1, GFP_NOFS); 2264 } 2265 EXPORT_SYMBOL(set_extent_buffer_dirty); 2266 2267 int set_extent_buffer_uptodate(struct extent_map_tree *tree, 2268 struct extent_buffer *eb) 2269 { 2270 unsigned long i; 2271 struct page *page; 2272 unsigned long num_pages; 2273 2274 num_pages = num_extent_pages(eb->start, eb->len); 2275 2276 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, 2277 GFP_NOFS); 2278 for (i = 0; i < num_pages; i++) { 2279 page = extent_buffer_page(eb, i); 2280 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2281 ((i == num_pages - 1) && 2282 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2283 check_page_uptodate(tree, page); 2284 continue; 2285 } 2286 SetPageUptodate(page); 2287 } 2288 return 0; 2289 } 2290 EXPORT_SYMBOL(set_extent_buffer_uptodate); 2291 2292 int extent_buffer_uptodate(struct extent_map_tree *tree, 2293 struct extent_buffer *eb) 2294 { 2295 if (eb->flags & EXTENT_UPTODATE) 2296 return 1; 2297 return test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2298 EXTENT_UPTODATE, 1); 2299 } 2300 EXPORT_SYMBOL(extent_buffer_uptodate); 2301 2302 int read_extent_buffer_pages(struct extent_map_tree *tree, 2303 struct extent_buffer *eb, 2304 u64 start, 2305 int wait) 2306 { 2307 unsigned long i; 2308 unsigned long start_i; 2309 struct page *page; 2310 int err; 2311 int ret = 0; 2312 unsigned long num_pages; 2313 2314 if (eb->flags & EXTENT_UPTODATE) 2315 return 0; 2316 2317 if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2318 EXTENT_UPTODATE, 1)) { 2319 return 0; 2320 } 2321 if (start) { 2322 WARN_ON(start < eb->start); 2323 start_i = (start >> PAGE_CACHE_SHIFT) - 2324 (eb->start >> PAGE_CACHE_SHIFT); 2325 } else { 2326 start_i = 0; 2327 } 2328 2329 num_pages = num_extent_pages(eb->start, eb->len); 2330 for (i = start_i; i < num_pages; i++) { 2331 page = extent_buffer_page(eb, i); 2332 if (PageUptodate(page)) { 2333 continue; 2334 } 2335 if (!wait) { 2336 if (TestSetPageLocked(page)) { 2337 continue; 2338 } 2339 } else { 2340 lock_page(page); 2341 } 2342 if (!PageUptodate(page)) { 2343 err = page->mapping->a_ops->readpage(NULL, page); 2344 if (err) { 2345 ret = err; 2346 } 2347 } else { 2348 unlock_page(page); 2349 } 2350 } 2351 2352 if (ret || !wait) { 2353 return ret; 2354 } 2355 2356 for (i = start_i; i < num_pages; i++) { 2357 page = extent_buffer_page(eb, i); 2358 wait_on_page_locked(page); 2359 if (!PageUptodate(page)) { 2360 ret = -EIO; 2361 } 2362 } 2363 if (!ret) 2364 eb->flags |= EXTENT_UPTODATE; 2365 return ret; 2366 } 2367 EXPORT_SYMBOL(read_extent_buffer_pages); 2368 2369 void read_extent_buffer(struct extent_buffer *eb, void *dstv, 2370 unsigned long start, 2371 unsigned long len) 2372 { 2373 size_t cur; 2374 size_t offset; 2375 struct page *page; 2376 char *kaddr; 2377 char *dst = (char *)dstv; 2378 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2379 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2380 unsigned long num_pages = num_extent_pages(eb->start, eb->len); 2381 2382 WARN_ON(start > eb->len); 2383 WARN_ON(start + len > eb->start + eb->len); 2384 2385 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2386 2387 while(len > 0) { 2388 page = extent_buffer_page(eb, i); 2389 if (!PageUptodate(page)) { 2390 printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); 2391 WARN_ON(1); 2392 } 2393 WARN_ON(!PageUptodate(page)); 2394 2395 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2396 kaddr = kmap_atomic(page, KM_USER1); 2397 memcpy(dst, kaddr + offset, cur); 2398 kunmap_atomic(kaddr, KM_USER1); 2399 2400 dst += cur; 2401 len -= cur; 2402 offset = 0; 2403 i++; 2404 } 2405 } 2406 EXPORT_SYMBOL(read_extent_buffer); 2407 2408 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, 2409 unsigned long min_len, char **token, char **map, 2410 unsigned long *map_start, 2411 unsigned long *map_len, int km) 2412 { 2413 size_t offset = start & (PAGE_CACHE_SIZE - 1); 2414 char *kaddr; 2415 struct page *p; 2416 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2417 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2418 unsigned long end_i = (start_offset + start + min_len - 1) >> 2419 PAGE_CACHE_SHIFT; 2420 2421 if (i != end_i) 2422 return -EINVAL; 2423 2424 if (i == 0) { 2425 offset = start_offset; 2426 *map_start = 0; 2427 } else { 2428 offset = 0; 2429 *map_start = (i << PAGE_CACHE_SHIFT) - start_offset; 2430 } 2431 if (start + min_len > eb->len) { 2432 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); 2433 WARN_ON(1); 2434 } 2435 2436 p = extent_buffer_page(eb, i); 2437 WARN_ON(!PageUptodate(p)); 2438 kaddr = kmap_atomic(p, km); 2439 *token = kaddr; 2440 *map = kaddr + offset; 2441 *map_len = PAGE_CACHE_SIZE - offset; 2442 return 0; 2443 } 2444 EXPORT_SYMBOL(map_private_extent_buffer); 2445 2446 int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 2447 unsigned long min_len, 2448 char **token, char **map, 2449 unsigned long *map_start, 2450 unsigned long *map_len, int km) 2451 { 2452 int err; 2453 int save = 0; 2454 if (eb->map_token) { 2455 unmap_extent_buffer(eb, eb->map_token, km); 2456 eb->map_token = NULL; 2457 save = 1; 2458 } 2459 err = map_private_extent_buffer(eb, start, min_len, token, map, 2460 map_start, map_len, km); 2461 if (!err && save) { 2462 eb->map_token = *token; 2463 eb->kaddr = *map; 2464 eb->map_start = *map_start; 2465 eb->map_len = *map_len; 2466 } 2467 return err; 2468 } 2469 EXPORT_SYMBOL(map_extent_buffer); 2470 2471 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) 2472 { 2473 kunmap_atomic(token, km); 2474 } 2475 EXPORT_SYMBOL(unmap_extent_buffer); 2476 2477 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 2478 unsigned long start, 2479 unsigned long len) 2480 { 2481 size_t cur; 2482 size_t offset; 2483 struct page *page; 2484 char *kaddr; 2485 char *ptr = (char *)ptrv; 2486 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2487 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2488 int ret = 0; 2489 2490 WARN_ON(start > eb->len); 2491 WARN_ON(start + len > eb->start + eb->len); 2492 2493 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2494 2495 while(len > 0) { 2496 page = extent_buffer_page(eb, i); 2497 WARN_ON(!PageUptodate(page)); 2498 2499 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2500 2501 kaddr = kmap_atomic(page, KM_USER0); 2502 ret = memcmp(ptr, kaddr + offset, cur); 2503 kunmap_atomic(kaddr, KM_USER0); 2504 if (ret) 2505 break; 2506 2507 ptr += cur; 2508 len -= cur; 2509 offset = 0; 2510 i++; 2511 } 2512 return ret; 2513 } 2514 EXPORT_SYMBOL(memcmp_extent_buffer); 2515 2516 void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 2517 unsigned long start, unsigned long len) 2518 { 2519 size_t cur; 2520 size_t offset; 2521 struct page *page; 2522 char *kaddr; 2523 char *src = (char *)srcv; 2524 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2525 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2526 2527 WARN_ON(start > eb->len); 2528 WARN_ON(start + len > eb->start + eb->len); 2529 2530 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2531 2532 while(len > 0) { 2533 page = extent_buffer_page(eb, i); 2534 WARN_ON(!PageUptodate(page)); 2535 2536 cur = min(len, PAGE_CACHE_SIZE - offset); 2537 kaddr = kmap_atomic(page, KM_USER1); 2538 memcpy(kaddr + offset, src, cur); 2539 kunmap_atomic(kaddr, KM_USER1); 2540 2541 src += cur; 2542 len -= cur; 2543 offset = 0; 2544 i++; 2545 } 2546 } 2547 EXPORT_SYMBOL(write_extent_buffer); 2548 2549 void memset_extent_buffer(struct extent_buffer *eb, char c, 2550 unsigned long start, unsigned long len) 2551 { 2552 size_t cur; 2553 size_t offset; 2554 struct page *page; 2555 char *kaddr; 2556 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2557 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2558 2559 WARN_ON(start > eb->len); 2560 WARN_ON(start + len > eb->start + eb->len); 2561 2562 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2563 2564 while(len > 0) { 2565 page = extent_buffer_page(eb, i); 2566 WARN_ON(!PageUptodate(page)); 2567 2568 cur = min(len, PAGE_CACHE_SIZE - offset); 2569 kaddr = kmap_atomic(page, KM_USER0); 2570 memset(kaddr + offset, c, cur); 2571 kunmap_atomic(kaddr, KM_USER0); 2572 2573 len -= cur; 2574 offset = 0; 2575 i++; 2576 } 2577 } 2578 EXPORT_SYMBOL(memset_extent_buffer); 2579 2580 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 2581 unsigned long dst_offset, unsigned long src_offset, 2582 unsigned long len) 2583 { 2584 u64 dst_len = dst->len; 2585 size_t cur; 2586 size_t offset; 2587 struct page *page; 2588 char *kaddr; 2589 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2590 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2591 2592 WARN_ON(src->len != dst_len); 2593 2594 offset = (start_offset + dst_offset) & 2595 ((unsigned long)PAGE_CACHE_SIZE - 1); 2596 2597 while(len > 0) { 2598 page = extent_buffer_page(dst, i); 2599 WARN_ON(!PageUptodate(page)); 2600 2601 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset)); 2602 2603 kaddr = kmap_atomic(page, KM_USER0); 2604 read_extent_buffer(src, kaddr + offset, src_offset, cur); 2605 kunmap_atomic(kaddr, KM_USER0); 2606 2607 src_offset += cur; 2608 len -= cur; 2609 offset = 0; 2610 i++; 2611 } 2612 } 2613 EXPORT_SYMBOL(copy_extent_buffer); 2614 2615 static void move_pages(struct page *dst_page, struct page *src_page, 2616 unsigned long dst_off, unsigned long src_off, 2617 unsigned long len) 2618 { 2619 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2620 if (dst_page == src_page) { 2621 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len); 2622 } else { 2623 char *src_kaddr = kmap_atomic(src_page, KM_USER1); 2624 char *p = dst_kaddr + dst_off + len; 2625 char *s = src_kaddr + src_off + len; 2626 2627 while (len--) 2628 *--p = *--s; 2629 2630 kunmap_atomic(src_kaddr, KM_USER1); 2631 } 2632 kunmap_atomic(dst_kaddr, KM_USER0); 2633 } 2634 2635 static void copy_pages(struct page *dst_page, struct page *src_page, 2636 unsigned long dst_off, unsigned long src_off, 2637 unsigned long len) 2638 { 2639 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2640 char *src_kaddr; 2641 2642 if (dst_page != src_page) 2643 src_kaddr = kmap_atomic(src_page, KM_USER1); 2644 else 2645 src_kaddr = dst_kaddr; 2646 2647 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); 2648 kunmap_atomic(dst_kaddr, KM_USER0); 2649 if (dst_page != src_page) 2650 kunmap_atomic(src_kaddr, KM_USER1); 2651 } 2652 2653 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2654 unsigned long src_offset, unsigned long len) 2655 { 2656 size_t cur; 2657 size_t dst_off_in_page; 2658 size_t src_off_in_page; 2659 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2660 unsigned long dst_i; 2661 unsigned long src_i; 2662 2663 if (src_offset + len > dst->len) { 2664 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2665 src_offset, len, dst->len); 2666 BUG_ON(1); 2667 } 2668 if (dst_offset + len > dst->len) { 2669 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2670 dst_offset, len, dst->len); 2671 BUG_ON(1); 2672 } 2673 2674 while(len > 0) { 2675 dst_off_in_page = (start_offset + dst_offset) & 2676 ((unsigned long)PAGE_CACHE_SIZE - 1); 2677 src_off_in_page = (start_offset + src_offset) & 2678 ((unsigned long)PAGE_CACHE_SIZE - 1); 2679 2680 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2681 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT; 2682 2683 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - 2684 src_off_in_page)); 2685 cur = min_t(unsigned long, cur, 2686 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page)); 2687 2688 copy_pages(extent_buffer_page(dst, dst_i), 2689 extent_buffer_page(dst, src_i), 2690 dst_off_in_page, src_off_in_page, cur); 2691 2692 src_offset += cur; 2693 dst_offset += cur; 2694 len -= cur; 2695 } 2696 } 2697 EXPORT_SYMBOL(memcpy_extent_buffer); 2698 2699 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2700 unsigned long src_offset, unsigned long len) 2701 { 2702 size_t cur; 2703 size_t dst_off_in_page; 2704 size_t src_off_in_page; 2705 unsigned long dst_end = dst_offset + len - 1; 2706 unsigned long src_end = src_offset + len - 1; 2707 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2708 unsigned long dst_i; 2709 unsigned long src_i; 2710 2711 if (src_offset + len > dst->len) { 2712 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2713 src_offset, len, dst->len); 2714 BUG_ON(1); 2715 } 2716 if (dst_offset + len > dst->len) { 2717 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2718 dst_offset, len, dst->len); 2719 BUG_ON(1); 2720 } 2721 if (dst_offset < src_offset) { 2722 memcpy_extent_buffer(dst, dst_offset, src_offset, len); 2723 return; 2724 } 2725 while(len > 0) { 2726 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT; 2727 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT; 2728 2729 dst_off_in_page = (start_offset + dst_end) & 2730 ((unsigned long)PAGE_CACHE_SIZE - 1); 2731 src_off_in_page = (start_offset + src_end) & 2732 ((unsigned long)PAGE_CACHE_SIZE - 1); 2733 2734 cur = min_t(unsigned long, len, src_off_in_page + 1); 2735 cur = min(cur, dst_off_in_page + 1); 2736 move_pages(extent_buffer_page(dst, dst_i), 2737 extent_buffer_page(dst, src_i), 2738 dst_off_in_page - cur + 1, 2739 src_off_in_page - cur + 1, cur); 2740 2741 dst_end -= cur; 2742 src_end -= cur; 2743 len -= cur; 2744 } 2745 } 2746 EXPORT_SYMBOL(memmove_extent_buffer); 2747