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 <linux/writeback.h> 14 #include <linux/pagevec.h> 15 #include "extent_map.h" 16 17 /* temporary define until extent_map moves out of btrfs */ 18 struct kmem_cache *btrfs_cache_create(const char *name, size_t size, 19 unsigned long extra_flags, 20 void (*ctor)(void *, struct kmem_cache *, 21 unsigned long)); 22 23 static struct kmem_cache *extent_map_cache; 24 static struct kmem_cache *extent_state_cache; 25 static struct kmem_cache *extent_buffer_cache; 26 27 static LIST_HEAD(buffers); 28 static LIST_HEAD(states); 29 30 static spinlock_t state_lock = SPIN_LOCK_UNLOCKED; 31 #define BUFFER_LRU_MAX 64 32 33 struct tree_entry { 34 u64 start; 35 u64 end; 36 int in_tree; 37 struct rb_node rb_node; 38 }; 39 40 struct extent_page_data { 41 struct bio *bio; 42 struct extent_map_tree *tree; 43 get_extent_t *get_extent; 44 }; 45 int __init extent_map_init(void) 46 { 47 extent_map_cache = btrfs_cache_create("extent_map", 48 sizeof(struct extent_map), 0, 49 NULL); 50 if (!extent_map_cache) 51 return -ENOMEM; 52 extent_state_cache = btrfs_cache_create("extent_state", 53 sizeof(struct extent_state), 0, 54 NULL); 55 if (!extent_state_cache) 56 goto free_map_cache; 57 extent_buffer_cache = btrfs_cache_create("extent_buffers", 58 sizeof(struct extent_buffer), 0, 59 NULL); 60 if (!extent_buffer_cache) 61 goto free_state_cache; 62 return 0; 63 64 free_state_cache: 65 kmem_cache_destroy(extent_state_cache); 66 free_map_cache: 67 kmem_cache_destroy(extent_map_cache); 68 return -ENOMEM; 69 } 70 71 void __exit extent_map_exit(void) 72 { 73 struct extent_state *state; 74 75 while (!list_empty(&states)) { 76 state = list_entry(states.next, struct extent_state, list); 77 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)); 78 list_del(&state->list); 79 kmem_cache_free(extent_state_cache, state); 80 81 } 82 83 if (extent_map_cache) 84 kmem_cache_destroy(extent_map_cache); 85 if (extent_state_cache) 86 kmem_cache_destroy(extent_state_cache); 87 if (extent_buffer_cache) 88 kmem_cache_destroy(extent_buffer_cache); 89 } 90 91 void extent_map_tree_init(struct extent_map_tree *tree, 92 struct address_space *mapping, gfp_t mask) 93 { 94 tree->map.rb_node = NULL; 95 tree->state.rb_node = NULL; 96 tree->ops = NULL; 97 rwlock_init(&tree->lock); 98 spin_lock_init(&tree->lru_lock); 99 tree->mapping = mapping; 100 INIT_LIST_HEAD(&tree->buffer_lru); 101 tree->lru_size = 0; 102 } 103 EXPORT_SYMBOL(extent_map_tree_init); 104 105 void extent_map_tree_empty_lru(struct extent_map_tree *tree) 106 { 107 struct extent_buffer *eb; 108 while(!list_empty(&tree->buffer_lru)) { 109 eb = list_entry(tree->buffer_lru.next, struct extent_buffer, 110 lru); 111 list_del_init(&eb->lru); 112 free_extent_buffer(eb); 113 } 114 } 115 EXPORT_SYMBOL(extent_map_tree_empty_lru); 116 117 struct extent_map *alloc_extent_map(gfp_t mask) 118 { 119 struct extent_map *em; 120 em = kmem_cache_alloc(extent_map_cache, mask); 121 if (!em || IS_ERR(em)) 122 return em; 123 em->in_tree = 0; 124 atomic_set(&em->refs, 1); 125 return em; 126 } 127 EXPORT_SYMBOL(alloc_extent_map); 128 129 void free_extent_map(struct extent_map *em) 130 { 131 if (!em) 132 return; 133 if (atomic_dec_and_test(&em->refs)) { 134 WARN_ON(em->in_tree); 135 kmem_cache_free(extent_map_cache, em); 136 } 137 } 138 EXPORT_SYMBOL(free_extent_map); 139 140 141 struct extent_state *alloc_extent_state(gfp_t mask) 142 { 143 struct extent_state *state; 144 unsigned long flags; 145 146 state = kmem_cache_alloc(extent_state_cache, mask); 147 if (!state || IS_ERR(state)) 148 return state; 149 state->state = 0; 150 state->in_tree = 0; 151 state->private = 0; 152 153 spin_lock_irqsave(&state_lock, flags); 154 list_add(&state->list, &states); 155 spin_unlock_irqrestore(&state_lock, flags); 156 157 atomic_set(&state->refs, 1); 158 init_waitqueue_head(&state->wq); 159 return state; 160 } 161 EXPORT_SYMBOL(alloc_extent_state); 162 163 void free_extent_state(struct extent_state *state) 164 { 165 unsigned long flags; 166 if (!state) 167 return; 168 if (atomic_dec_and_test(&state->refs)) { 169 WARN_ON(state->in_tree); 170 spin_lock_irqsave(&state_lock, flags); 171 list_del(&state->list); 172 spin_unlock_irqrestore(&state_lock, flags); 173 kmem_cache_free(extent_state_cache, state); 174 } 175 } 176 EXPORT_SYMBOL(free_extent_state); 177 178 static struct rb_node *tree_insert(struct rb_root *root, u64 offset, 179 struct rb_node *node) 180 { 181 struct rb_node ** p = &root->rb_node; 182 struct rb_node * parent = NULL; 183 struct tree_entry *entry; 184 185 while(*p) { 186 parent = *p; 187 entry = rb_entry(parent, struct tree_entry, rb_node); 188 189 if (offset < entry->start) 190 p = &(*p)->rb_left; 191 else if (offset > entry->end) 192 p = &(*p)->rb_right; 193 else 194 return parent; 195 } 196 197 entry = rb_entry(node, struct tree_entry, rb_node); 198 entry->in_tree = 1; 199 rb_link_node(node, parent, p); 200 rb_insert_color(node, root); 201 return NULL; 202 } 203 204 static struct rb_node *__tree_search(struct rb_root *root, u64 offset, 205 struct rb_node **prev_ret) 206 { 207 struct rb_node * n = root->rb_node; 208 struct rb_node *prev = NULL; 209 struct tree_entry *entry; 210 struct tree_entry *prev_entry = NULL; 211 212 while(n) { 213 entry = rb_entry(n, struct tree_entry, rb_node); 214 prev = n; 215 prev_entry = entry; 216 217 if (offset < entry->start) 218 n = n->rb_left; 219 else if (offset > entry->end) 220 n = n->rb_right; 221 else 222 return n; 223 } 224 if (!prev_ret) 225 return NULL; 226 while(prev && offset > prev_entry->end) { 227 prev = rb_next(prev); 228 prev_entry = rb_entry(prev, struct tree_entry, rb_node); 229 } 230 *prev_ret = prev; 231 return NULL; 232 } 233 234 static inline struct rb_node *tree_search(struct rb_root *root, u64 offset) 235 { 236 struct rb_node *prev; 237 struct rb_node *ret; 238 ret = __tree_search(root, offset, &prev); 239 if (!ret) 240 return prev; 241 return ret; 242 } 243 244 static int tree_delete(struct rb_root *root, u64 offset) 245 { 246 struct rb_node *node; 247 struct tree_entry *entry; 248 249 node = __tree_search(root, offset, NULL); 250 if (!node) 251 return -ENOENT; 252 entry = rb_entry(node, struct tree_entry, rb_node); 253 entry->in_tree = 0; 254 rb_erase(node, root); 255 return 0; 256 } 257 258 /* 259 * add_extent_mapping tries a simple backward merge with existing 260 * mappings. The extent_map struct passed in will be inserted into 261 * the tree directly (no copies made, just a reference taken). 262 */ 263 int add_extent_mapping(struct extent_map_tree *tree, 264 struct extent_map *em) 265 { 266 int ret = 0; 267 struct extent_map *prev = NULL; 268 struct rb_node *rb; 269 270 write_lock_irq(&tree->lock); 271 rb = tree_insert(&tree->map, em->end, &em->rb_node); 272 if (rb) { 273 prev = rb_entry(rb, struct extent_map, rb_node); 274 printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev->start, prev->end, em->start, em->end); 275 ret = -EEXIST; 276 goto out; 277 } 278 atomic_inc(&em->refs); 279 if (em->start != 0) { 280 rb = rb_prev(&em->rb_node); 281 if (rb) 282 prev = rb_entry(rb, struct extent_map, rb_node); 283 if (prev && prev->end + 1 == em->start && 284 ((em->block_start == EXTENT_MAP_HOLE && 285 prev->block_start == EXTENT_MAP_HOLE) || 286 (em->block_start == EXTENT_MAP_INLINE && 287 prev->block_start == EXTENT_MAP_INLINE) || 288 (em->block_start == EXTENT_MAP_DELALLOC && 289 prev->block_start == EXTENT_MAP_DELALLOC) || 290 (em->block_start < EXTENT_MAP_DELALLOC - 1 && 291 em->block_start == prev->block_end + 1))) { 292 em->start = prev->start; 293 em->block_start = prev->block_start; 294 rb_erase(&prev->rb_node, &tree->map); 295 prev->in_tree = 0; 296 free_extent_map(prev); 297 } 298 } 299 out: 300 write_unlock_irq(&tree->lock); 301 return ret; 302 } 303 EXPORT_SYMBOL(add_extent_mapping); 304 305 /* 306 * lookup_extent_mapping returns the first extent_map struct in the 307 * tree that intersects the [start, end] (inclusive) range. There may 308 * be additional objects in the tree that intersect, so check the object 309 * returned carefully to make sure you don't need additional lookups. 310 */ 311 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, 312 u64 start, u64 end) 313 { 314 struct extent_map *em; 315 struct rb_node *rb_node; 316 317 read_lock_irq(&tree->lock); 318 rb_node = tree_search(&tree->map, start); 319 if (!rb_node) { 320 em = NULL; 321 goto out; 322 } 323 if (IS_ERR(rb_node)) { 324 em = ERR_PTR(PTR_ERR(rb_node)); 325 goto out; 326 } 327 em = rb_entry(rb_node, struct extent_map, rb_node); 328 if (em->end < start || em->start > end) { 329 em = NULL; 330 goto out; 331 } 332 atomic_inc(&em->refs); 333 out: 334 read_unlock_irq(&tree->lock); 335 return em; 336 } 337 EXPORT_SYMBOL(lookup_extent_mapping); 338 339 /* 340 * removes an extent_map struct from the tree. No reference counts are 341 * dropped, and no checks are done to see if the range is in use 342 */ 343 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) 344 { 345 int ret; 346 347 write_lock_irq(&tree->lock); 348 ret = tree_delete(&tree->map, em->end); 349 write_unlock_irq(&tree->lock); 350 return ret; 351 } 352 EXPORT_SYMBOL(remove_extent_mapping); 353 354 /* 355 * utility function to look for merge candidates inside a given range. 356 * Any extents with matching state are merged together into a single 357 * extent in the tree. Extents with EXTENT_IO in their state field 358 * are not merged because the end_io handlers need to be able to do 359 * operations on them without sleeping (or doing allocations/splits). 360 * 361 * This should be called with the tree lock held. 362 */ 363 static int merge_state(struct extent_map_tree *tree, 364 struct extent_state *state) 365 { 366 struct extent_state *other; 367 struct rb_node *other_node; 368 369 if (state->state & EXTENT_IOBITS) 370 return 0; 371 372 other_node = rb_prev(&state->rb_node); 373 if (other_node) { 374 other = rb_entry(other_node, struct extent_state, rb_node); 375 if (other->end == state->start - 1 && 376 other->state == state->state) { 377 state->start = other->start; 378 other->in_tree = 0; 379 rb_erase(&other->rb_node, &tree->state); 380 free_extent_state(other); 381 } 382 } 383 other_node = rb_next(&state->rb_node); 384 if (other_node) { 385 other = rb_entry(other_node, struct extent_state, rb_node); 386 if (other->start == state->end + 1 && 387 other->state == state->state) { 388 other->start = state->start; 389 state->in_tree = 0; 390 rb_erase(&state->rb_node, &tree->state); 391 free_extent_state(state); 392 } 393 } 394 return 0; 395 } 396 397 /* 398 * insert an extent_state struct into the tree. 'bits' are set on the 399 * struct before it is inserted. 400 * 401 * This may return -EEXIST if the extent is already there, in which case the 402 * state struct is freed. 403 * 404 * The tree lock is not taken internally. This is a utility function and 405 * probably isn't what you want to call (see set/clear_extent_bit). 406 */ 407 static int insert_state(struct extent_map_tree *tree, 408 struct extent_state *state, u64 start, u64 end, 409 int bits) 410 { 411 struct rb_node *node; 412 413 if (end < start) { 414 printk("end < start %Lu %Lu\n", end, start); 415 WARN_ON(1); 416 } 417 state->state |= bits; 418 state->start = start; 419 state->end = end; 420 node = tree_insert(&tree->state, end, &state->rb_node); 421 if (node) { 422 struct extent_state *found; 423 found = rb_entry(node, struct extent_state, rb_node); 424 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end); 425 free_extent_state(state); 426 return -EEXIST; 427 } 428 merge_state(tree, state); 429 return 0; 430 } 431 432 /* 433 * split a given extent state struct in two, inserting the preallocated 434 * struct 'prealloc' as the newly created second half. 'split' indicates an 435 * offset inside 'orig' where it should be split. 436 * 437 * Before calling, 438 * the tree has 'orig' at [orig->start, orig->end]. After calling, there 439 * are two extent state structs in the tree: 440 * prealloc: [orig->start, split - 1] 441 * orig: [ split, orig->end ] 442 * 443 * The tree locks are not taken by this function. They need to be held 444 * by the caller. 445 */ 446 static int split_state(struct extent_map_tree *tree, struct extent_state *orig, 447 struct extent_state *prealloc, u64 split) 448 { 449 struct rb_node *node; 450 prealloc->start = orig->start; 451 prealloc->end = split - 1; 452 prealloc->state = orig->state; 453 orig->start = split; 454 455 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node); 456 if (node) { 457 struct extent_state *found; 458 found = rb_entry(node, struct extent_state, rb_node); 459 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end); 460 free_extent_state(prealloc); 461 return -EEXIST; 462 } 463 return 0; 464 } 465 466 /* 467 * utility function to clear some bits in an extent state struct. 468 * it will optionally wake up any one waiting on this state (wake == 1), or 469 * forcibly remove the state from the tree (delete == 1). 470 * 471 * If no bits are set on the state struct after clearing things, the 472 * struct is freed and removed from the tree 473 */ 474 static int clear_state_bit(struct extent_map_tree *tree, 475 struct extent_state *state, int bits, int wake, 476 int delete) 477 { 478 int ret = state->state & bits; 479 state->state &= ~bits; 480 if (wake) 481 wake_up(&state->wq); 482 if (delete || state->state == 0) { 483 if (state->in_tree) { 484 rb_erase(&state->rb_node, &tree->state); 485 state->in_tree = 0; 486 free_extent_state(state); 487 } else { 488 WARN_ON(1); 489 } 490 } else { 491 merge_state(tree, state); 492 } 493 return ret; 494 } 495 496 /* 497 * clear some bits on a range in the tree. This may require splitting 498 * or inserting elements in the tree, so the gfp mask is used to 499 * indicate which allocations or sleeping are allowed. 500 * 501 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove 502 * the given range from the tree regardless of state (ie for truncate). 503 * 504 * the range [start, end] is inclusive. 505 * 506 * This takes the tree lock, and returns < 0 on error, > 0 if any of the 507 * bits were already set, or zero if none of the bits were already set. 508 */ 509 int clear_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, 510 int bits, int wake, int delete, gfp_t mask) 511 { 512 struct extent_state *state; 513 struct extent_state *prealloc = NULL; 514 struct rb_node *node; 515 unsigned long flags; 516 int err; 517 int set = 0; 518 519 again: 520 if (!prealloc && (mask & __GFP_WAIT)) { 521 prealloc = alloc_extent_state(mask); 522 if (!prealloc) 523 return -ENOMEM; 524 } 525 526 write_lock_irqsave(&tree->lock, flags); 527 /* 528 * this search will find the extents that end after 529 * our range starts 530 */ 531 node = tree_search(&tree->state, start); 532 if (!node) 533 goto out; 534 state = rb_entry(node, struct extent_state, rb_node); 535 if (state->start > end) 536 goto out; 537 WARN_ON(state->end < start); 538 539 /* 540 * | ---- desired range ---- | 541 * | state | or 542 * | ------------- state -------------- | 543 * 544 * We need to split the extent we found, and may flip 545 * bits on second half. 546 * 547 * If the extent we found extends past our range, we 548 * just split and search again. It'll get split again 549 * the next time though. 550 * 551 * If the extent we found is inside our range, we clear 552 * the desired bit on it. 553 */ 554 555 if (state->start < start) { 556 err = split_state(tree, state, prealloc, start); 557 BUG_ON(err == -EEXIST); 558 prealloc = NULL; 559 if (err) 560 goto out; 561 if (state->end <= end) { 562 start = state->end + 1; 563 set |= clear_state_bit(tree, state, bits, 564 wake, delete); 565 } else { 566 start = state->start; 567 } 568 goto search_again; 569 } 570 /* 571 * | ---- desired range ---- | 572 * | state | 573 * We need to split the extent, and clear the bit 574 * on the first half 575 */ 576 if (state->start <= end && state->end > end) { 577 err = split_state(tree, state, prealloc, end + 1); 578 BUG_ON(err == -EEXIST); 579 580 if (wake) 581 wake_up(&state->wq); 582 set |= clear_state_bit(tree, prealloc, bits, 583 wake, delete); 584 prealloc = NULL; 585 goto out; 586 } 587 588 start = state->end + 1; 589 set |= clear_state_bit(tree, state, bits, wake, delete); 590 goto search_again; 591 592 out: 593 write_unlock_irqrestore(&tree->lock, flags); 594 if (prealloc) 595 free_extent_state(prealloc); 596 597 return set; 598 599 search_again: 600 if (start > end) 601 goto out; 602 write_unlock_irqrestore(&tree->lock, flags); 603 if (mask & __GFP_WAIT) 604 cond_resched(); 605 goto again; 606 } 607 EXPORT_SYMBOL(clear_extent_bit); 608 609 static int wait_on_state(struct extent_map_tree *tree, 610 struct extent_state *state) 611 { 612 DEFINE_WAIT(wait); 613 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); 614 read_unlock_irq(&tree->lock); 615 schedule(); 616 read_lock_irq(&tree->lock); 617 finish_wait(&state->wq, &wait); 618 return 0; 619 } 620 621 /* 622 * waits for one or more bits to clear on a range in the state tree. 623 * The range [start, end] is inclusive. 624 * The tree lock is taken by this function 625 */ 626 int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits) 627 { 628 struct extent_state *state; 629 struct rb_node *node; 630 631 read_lock_irq(&tree->lock); 632 again: 633 while (1) { 634 /* 635 * this search will find all the extents that end after 636 * our range starts 637 */ 638 node = tree_search(&tree->state, start); 639 if (!node) 640 break; 641 642 state = rb_entry(node, struct extent_state, rb_node); 643 644 if (state->start > end) 645 goto out; 646 647 if (state->state & bits) { 648 start = state->start; 649 atomic_inc(&state->refs); 650 wait_on_state(tree, state); 651 free_extent_state(state); 652 goto again; 653 } 654 start = state->end + 1; 655 656 if (start > end) 657 break; 658 659 if (need_resched()) { 660 read_unlock_irq(&tree->lock); 661 cond_resched(); 662 read_lock_irq(&tree->lock); 663 } 664 } 665 out: 666 read_unlock_irq(&tree->lock); 667 return 0; 668 } 669 EXPORT_SYMBOL(wait_extent_bit); 670 671 /* 672 * set some bits on a range in the tree. This may require allocations 673 * or sleeping, so the gfp mask is used to indicate what is allowed. 674 * 675 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the 676 * range already has the desired bits set. The start of the existing 677 * range is returned in failed_start in this case. 678 * 679 * [start, end] is inclusive 680 * This takes the tree lock. 681 */ 682 int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, 683 int exclusive, u64 *failed_start, gfp_t mask) 684 { 685 struct extent_state *state; 686 struct extent_state *prealloc = NULL; 687 struct rb_node *node; 688 unsigned long flags; 689 int err = 0; 690 int set; 691 u64 last_start; 692 u64 last_end; 693 again: 694 if (!prealloc && (mask & __GFP_WAIT)) { 695 prealloc = alloc_extent_state(mask); 696 if (!prealloc) 697 return -ENOMEM; 698 } 699 700 write_lock_irqsave(&tree->lock, flags); 701 /* 702 * this search will find all the extents that end after 703 * our range starts. 704 */ 705 node = tree_search(&tree->state, start); 706 if (!node) { 707 err = insert_state(tree, prealloc, start, end, bits); 708 prealloc = NULL; 709 BUG_ON(err == -EEXIST); 710 goto out; 711 } 712 713 state = rb_entry(node, struct extent_state, rb_node); 714 last_start = state->start; 715 last_end = state->end; 716 717 /* 718 * | ---- desired range ---- | 719 * | state | 720 * 721 * Just lock what we found and keep going 722 */ 723 if (state->start == start && state->end <= end) { 724 set = state->state & bits; 725 if (set && exclusive) { 726 *failed_start = state->start; 727 err = -EEXIST; 728 goto out; 729 } 730 state->state |= bits; 731 start = state->end + 1; 732 merge_state(tree, state); 733 goto search_again; 734 } 735 736 /* 737 * | ---- desired range ---- | 738 * | state | 739 * or 740 * | ------------- state -------------- | 741 * 742 * We need to split the extent we found, and may flip bits on 743 * second half. 744 * 745 * If the extent we found extends past our 746 * range, we just split and search again. It'll get split 747 * again the next time though. 748 * 749 * If the extent we found is inside our range, we set the 750 * desired bit on it. 751 */ 752 if (state->start < start) { 753 set = state->state & bits; 754 if (exclusive && set) { 755 *failed_start = start; 756 err = -EEXIST; 757 goto out; 758 } 759 err = split_state(tree, state, prealloc, start); 760 BUG_ON(err == -EEXIST); 761 prealloc = NULL; 762 if (err) 763 goto out; 764 if (state->end <= end) { 765 state->state |= bits; 766 start = state->end + 1; 767 merge_state(tree, state); 768 } else { 769 start = state->start; 770 } 771 goto search_again; 772 } 773 /* 774 * | ---- desired range ---- | 775 * | state | or | state | 776 * 777 * There's a hole, we need to insert something in it and 778 * ignore the extent we found. 779 */ 780 if (state->start > start) { 781 u64 this_end; 782 if (end < last_start) 783 this_end = end; 784 else 785 this_end = last_start -1; 786 err = insert_state(tree, prealloc, start, this_end, 787 bits); 788 prealloc = NULL; 789 BUG_ON(err == -EEXIST); 790 if (err) 791 goto out; 792 start = this_end + 1; 793 goto search_again; 794 } 795 /* 796 * | ---- desired range ---- | 797 * | state | 798 * We need to split the extent, and set the bit 799 * on the first half 800 */ 801 if (state->start <= end && state->end > end) { 802 set = state->state & bits; 803 if (exclusive && set) { 804 *failed_start = start; 805 err = -EEXIST; 806 goto out; 807 } 808 err = split_state(tree, state, prealloc, end + 1); 809 BUG_ON(err == -EEXIST); 810 811 prealloc->state |= bits; 812 merge_state(tree, prealloc); 813 prealloc = NULL; 814 goto out; 815 } 816 817 goto search_again; 818 819 out: 820 write_unlock_irqrestore(&tree->lock, flags); 821 if (prealloc) 822 free_extent_state(prealloc); 823 824 return err; 825 826 search_again: 827 if (start > end) 828 goto out; 829 write_unlock_irqrestore(&tree->lock, flags); 830 if (mask & __GFP_WAIT) 831 cond_resched(); 832 goto again; 833 } 834 EXPORT_SYMBOL(set_extent_bit); 835 836 /* wrappers around set/clear extent bit */ 837 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 838 gfp_t mask) 839 { 840 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, 841 mask); 842 } 843 EXPORT_SYMBOL(set_extent_dirty); 844 845 int set_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 846 int bits, gfp_t mask) 847 { 848 return set_extent_bit(tree, start, end, bits, 0, NULL, 849 mask); 850 } 851 EXPORT_SYMBOL(set_extent_bits); 852 853 int clear_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 854 int bits, gfp_t mask) 855 { 856 return clear_extent_bit(tree, start, end, bits, 0, 0, mask); 857 } 858 EXPORT_SYMBOL(clear_extent_bits); 859 860 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end, 861 gfp_t mask) 862 { 863 return set_extent_bit(tree, start, end, 864 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL, 865 mask); 866 } 867 EXPORT_SYMBOL(set_extent_delalloc); 868 869 int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 870 gfp_t mask) 871 { 872 return clear_extent_bit(tree, start, end, 873 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask); 874 } 875 EXPORT_SYMBOL(clear_extent_dirty); 876 877 int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 878 gfp_t mask) 879 { 880 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, 881 mask); 882 } 883 EXPORT_SYMBOL(set_extent_new); 884 885 int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 886 gfp_t mask) 887 { 888 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask); 889 } 890 EXPORT_SYMBOL(clear_extent_new); 891 892 int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 893 gfp_t mask) 894 { 895 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL, 896 mask); 897 } 898 EXPORT_SYMBOL(set_extent_uptodate); 899 900 int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 901 gfp_t mask) 902 { 903 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask); 904 } 905 EXPORT_SYMBOL(clear_extent_uptodate); 906 907 int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 908 gfp_t mask) 909 { 910 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK, 911 0, NULL, mask); 912 } 913 EXPORT_SYMBOL(set_extent_writeback); 914 915 int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 916 gfp_t mask) 917 { 918 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask); 919 } 920 EXPORT_SYMBOL(clear_extent_writeback); 921 922 int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end) 923 { 924 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK); 925 } 926 EXPORT_SYMBOL(wait_on_extent_writeback); 927 928 /* 929 * locks a range in ascending order, waiting for any locked regions 930 * it hits on the way. [start,end] are inclusive, and this will sleep. 931 */ 932 int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask) 933 { 934 int err; 935 u64 failed_start; 936 while (1) { 937 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 938 &failed_start, mask); 939 if (err == -EEXIST && (mask & __GFP_WAIT)) { 940 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); 941 start = failed_start; 942 } else { 943 break; 944 } 945 WARN_ON(start > end); 946 } 947 return err; 948 } 949 EXPORT_SYMBOL(lock_extent); 950 951 int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, 952 gfp_t mask) 953 { 954 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask); 955 } 956 EXPORT_SYMBOL(unlock_extent); 957 958 /* 959 * helper function to set pages and extents in the tree dirty 960 */ 961 int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end) 962 { 963 unsigned long index = start >> PAGE_CACHE_SHIFT; 964 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 965 struct page *page; 966 967 while (index <= end_index) { 968 page = find_get_page(tree->mapping, index); 969 BUG_ON(!page); 970 __set_page_dirty_nobuffers(page); 971 page_cache_release(page); 972 index++; 973 } 974 set_extent_dirty(tree, start, end, GFP_NOFS); 975 return 0; 976 } 977 EXPORT_SYMBOL(set_range_dirty); 978 979 /* 980 * helper function to set both pages and extents in the tree writeback 981 */ 982 int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end) 983 { 984 unsigned long index = start >> PAGE_CACHE_SHIFT; 985 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 986 struct page *page; 987 988 while (index <= end_index) { 989 page = find_get_page(tree->mapping, index); 990 BUG_ON(!page); 991 set_page_writeback(page); 992 page_cache_release(page); 993 index++; 994 } 995 set_extent_writeback(tree, start, end, GFP_NOFS); 996 return 0; 997 } 998 EXPORT_SYMBOL(set_range_writeback); 999 1000 int find_first_extent_bit(struct extent_map_tree *tree, u64 start, 1001 u64 *start_ret, u64 *end_ret, int bits) 1002 { 1003 struct rb_node *node; 1004 struct extent_state *state; 1005 int ret = 1; 1006 1007 read_lock_irq(&tree->lock); 1008 /* 1009 * this search will find all the extents that end after 1010 * our range starts. 1011 */ 1012 node = tree_search(&tree->state, start); 1013 if (!node || IS_ERR(node)) { 1014 goto out; 1015 } 1016 1017 while(1) { 1018 state = rb_entry(node, struct extent_state, rb_node); 1019 if (state->end >= start && (state->state & bits)) { 1020 *start_ret = state->start; 1021 *end_ret = state->end; 1022 ret = 0; 1023 break; 1024 } 1025 node = rb_next(node); 1026 if (!node) 1027 break; 1028 } 1029 out: 1030 read_unlock_irq(&tree->lock); 1031 return ret; 1032 } 1033 EXPORT_SYMBOL(find_first_extent_bit); 1034 1035 u64 find_lock_delalloc_range(struct extent_map_tree *tree, 1036 u64 start, u64 lock_start, u64 *end, u64 max_bytes) 1037 { 1038 struct rb_node *node; 1039 struct extent_state *state; 1040 u64 cur_start = start; 1041 u64 found = 0; 1042 u64 total_bytes = 0; 1043 1044 write_lock_irq(&tree->lock); 1045 /* 1046 * this search will find all the extents that end after 1047 * our range starts. 1048 */ 1049 search_again: 1050 node = tree_search(&tree->state, cur_start); 1051 if (!node || IS_ERR(node)) { 1052 goto out; 1053 } 1054 1055 while(1) { 1056 state = rb_entry(node, struct extent_state, rb_node); 1057 if (state->start != cur_start) { 1058 goto out; 1059 } 1060 if (!(state->state & EXTENT_DELALLOC)) { 1061 goto out; 1062 } 1063 if (state->start >= lock_start) { 1064 if (state->state & EXTENT_LOCKED) { 1065 DEFINE_WAIT(wait); 1066 atomic_inc(&state->refs); 1067 prepare_to_wait(&state->wq, &wait, 1068 TASK_UNINTERRUPTIBLE); 1069 write_unlock_irq(&tree->lock); 1070 schedule(); 1071 write_lock_irq(&tree->lock); 1072 finish_wait(&state->wq, &wait); 1073 free_extent_state(state); 1074 goto search_again; 1075 } 1076 state->state |= EXTENT_LOCKED; 1077 } 1078 found++; 1079 *end = state->end; 1080 cur_start = state->end + 1; 1081 node = rb_next(node); 1082 if (!node) 1083 break; 1084 total_bytes += state->end - state->start + 1; 1085 if (total_bytes >= max_bytes) 1086 break; 1087 } 1088 out: 1089 write_unlock_irq(&tree->lock); 1090 return found; 1091 } 1092 1093 /* 1094 * helper function to lock both pages and extents in the tree. 1095 * pages must be locked first. 1096 */ 1097 int lock_range(struct extent_map_tree *tree, u64 start, u64 end) 1098 { 1099 unsigned long index = start >> PAGE_CACHE_SHIFT; 1100 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1101 struct page *page; 1102 int err; 1103 1104 while (index <= end_index) { 1105 page = grab_cache_page(tree->mapping, index); 1106 if (!page) { 1107 err = -ENOMEM; 1108 goto failed; 1109 } 1110 if (IS_ERR(page)) { 1111 err = PTR_ERR(page); 1112 goto failed; 1113 } 1114 index++; 1115 } 1116 lock_extent(tree, start, end, GFP_NOFS); 1117 return 0; 1118 1119 failed: 1120 /* 1121 * we failed above in getting the page at 'index', so we undo here 1122 * up to but not including the page at 'index' 1123 */ 1124 end_index = index; 1125 index = start >> PAGE_CACHE_SHIFT; 1126 while (index < end_index) { 1127 page = find_get_page(tree->mapping, index); 1128 unlock_page(page); 1129 page_cache_release(page); 1130 index++; 1131 } 1132 return err; 1133 } 1134 EXPORT_SYMBOL(lock_range); 1135 1136 /* 1137 * helper function to unlock both pages and extents in the tree. 1138 */ 1139 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end) 1140 { 1141 unsigned long index = start >> PAGE_CACHE_SHIFT; 1142 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1143 struct page *page; 1144 1145 while (index <= end_index) { 1146 page = find_get_page(tree->mapping, index); 1147 unlock_page(page); 1148 page_cache_release(page); 1149 index++; 1150 } 1151 unlock_extent(tree, start, end, GFP_NOFS); 1152 return 0; 1153 } 1154 EXPORT_SYMBOL(unlock_range); 1155 1156 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private) 1157 { 1158 struct rb_node *node; 1159 struct extent_state *state; 1160 int ret = 0; 1161 1162 write_lock_irq(&tree->lock); 1163 /* 1164 * this search will find all the extents that end after 1165 * our range starts. 1166 */ 1167 node = tree_search(&tree->state, start); 1168 if (!node || IS_ERR(node)) { 1169 ret = -ENOENT; 1170 goto out; 1171 } 1172 state = rb_entry(node, struct extent_state, rb_node); 1173 if (state->start != start) { 1174 ret = -ENOENT; 1175 goto out; 1176 } 1177 state->private = private; 1178 out: 1179 write_unlock_irq(&tree->lock); 1180 return ret; 1181 } 1182 1183 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private) 1184 { 1185 struct rb_node *node; 1186 struct extent_state *state; 1187 int ret = 0; 1188 1189 read_lock_irq(&tree->lock); 1190 /* 1191 * this search will find all the extents that end after 1192 * our range starts. 1193 */ 1194 node = tree_search(&tree->state, start); 1195 if (!node || IS_ERR(node)) { 1196 ret = -ENOENT; 1197 goto out; 1198 } 1199 state = rb_entry(node, struct extent_state, rb_node); 1200 if (state->start != start) { 1201 ret = -ENOENT; 1202 goto out; 1203 } 1204 *private = state->private; 1205 out: 1206 read_unlock_irq(&tree->lock); 1207 return ret; 1208 } 1209 1210 /* 1211 * searches a range in the state tree for a given mask. 1212 * If 'filled' == 1, this returns 1 only if ever extent in the tree 1213 * has the bits set. Otherwise, 1 is returned if any bit in the 1214 * range is found set. 1215 */ 1216 int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end, 1217 int bits, int filled) 1218 { 1219 struct extent_state *state = NULL; 1220 struct rb_node *node; 1221 int bitset = 0; 1222 1223 read_lock_irq(&tree->lock); 1224 node = tree_search(&tree->state, start); 1225 while (node && start <= end) { 1226 state = rb_entry(node, struct extent_state, rb_node); 1227 1228 if (filled && state->start > start) { 1229 bitset = 0; 1230 break; 1231 } 1232 1233 if (state->start > end) 1234 break; 1235 1236 if (state->state & bits) { 1237 bitset = 1; 1238 if (!filled) 1239 break; 1240 } else if (filled) { 1241 bitset = 0; 1242 break; 1243 } 1244 start = state->end + 1; 1245 if (start > end) 1246 break; 1247 node = rb_next(node); 1248 } 1249 read_unlock_irq(&tree->lock); 1250 return bitset; 1251 } 1252 EXPORT_SYMBOL(test_range_bit); 1253 1254 /* 1255 * helper function to set a given page up to date if all the 1256 * extents in the tree for that page are up to date 1257 */ 1258 static int check_page_uptodate(struct extent_map_tree *tree, 1259 struct page *page) 1260 { 1261 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1262 u64 end = start + PAGE_CACHE_SIZE - 1; 1263 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1)) 1264 SetPageUptodate(page); 1265 return 0; 1266 } 1267 1268 /* 1269 * helper function to unlock a page if all the extents in the tree 1270 * for that page are unlocked 1271 */ 1272 static int check_page_locked(struct extent_map_tree *tree, 1273 struct page *page) 1274 { 1275 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1276 u64 end = start + PAGE_CACHE_SIZE - 1; 1277 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0)) 1278 unlock_page(page); 1279 return 0; 1280 } 1281 1282 /* 1283 * helper function to end page writeback if all the extents 1284 * in the tree for that page are done with writeback 1285 */ 1286 static int check_page_writeback(struct extent_map_tree *tree, 1287 struct page *page) 1288 { 1289 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1290 u64 end = start + PAGE_CACHE_SIZE - 1; 1291 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0)) 1292 end_page_writeback(page); 1293 return 0; 1294 } 1295 1296 /* lots and lots of room for performance fixes in the end_bio funcs */ 1297 1298 /* 1299 * after a writepage IO is done, we need to: 1300 * clear the uptodate bits on error 1301 * clear the writeback bits in the extent tree for this IO 1302 * end_page_writeback if the page has no more pending IO 1303 * 1304 * Scheduling is not allowed, so the extent state tree is expected 1305 * to have one and only one object corresponding to this IO. 1306 */ 1307 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1308 static void end_bio_extent_writepage(struct bio *bio, int err) 1309 #else 1310 static int end_bio_extent_writepage(struct bio *bio, 1311 unsigned int bytes_done, int err) 1312 #endif 1313 { 1314 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1315 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1316 struct extent_map_tree *tree = bio->bi_private; 1317 u64 start; 1318 u64 end; 1319 int whole_page; 1320 1321 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1322 if (bio->bi_size) 1323 return 1; 1324 #endif 1325 1326 do { 1327 struct page *page = bvec->bv_page; 1328 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1329 bvec->bv_offset; 1330 end = start + bvec->bv_len - 1; 1331 1332 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1333 whole_page = 1; 1334 else 1335 whole_page = 0; 1336 1337 if (--bvec >= bio->bi_io_vec) 1338 prefetchw(&bvec->bv_page->flags); 1339 1340 if (!uptodate) { 1341 clear_extent_uptodate(tree, start, end, GFP_ATOMIC); 1342 ClearPageUptodate(page); 1343 SetPageError(page); 1344 } 1345 clear_extent_writeback(tree, start, end, GFP_ATOMIC); 1346 1347 if (whole_page) 1348 end_page_writeback(page); 1349 else 1350 check_page_writeback(tree, page); 1351 if (tree->ops && tree->ops->writepage_end_io_hook) 1352 tree->ops->writepage_end_io_hook(page, start, end); 1353 } while (bvec >= bio->bi_io_vec); 1354 1355 bio_put(bio); 1356 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1357 return 0; 1358 #endif 1359 } 1360 1361 /* 1362 * after a readpage IO is done, we need to: 1363 * clear the uptodate bits on error 1364 * set the uptodate bits if things worked 1365 * set the page up to date if all extents in the tree are uptodate 1366 * clear the lock bit in the extent tree 1367 * unlock the page if there are no other extents locked for it 1368 * 1369 * Scheduling is not allowed, so the extent state tree is expected 1370 * to have one and only one object corresponding to this IO. 1371 */ 1372 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1373 static void end_bio_extent_readpage(struct bio *bio, int err) 1374 #else 1375 static int end_bio_extent_readpage(struct bio *bio, 1376 unsigned int bytes_done, int err) 1377 #endif 1378 { 1379 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1380 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1381 struct extent_map_tree *tree = bio->bi_private; 1382 u64 start; 1383 u64 end; 1384 int whole_page; 1385 int ret; 1386 1387 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1388 if (bio->bi_size) 1389 return 1; 1390 #endif 1391 1392 do { 1393 struct page *page = bvec->bv_page; 1394 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1395 bvec->bv_offset; 1396 end = start + bvec->bv_len - 1; 1397 1398 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1399 whole_page = 1; 1400 else 1401 whole_page = 0; 1402 1403 if (--bvec >= bio->bi_io_vec) 1404 prefetchw(&bvec->bv_page->flags); 1405 1406 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { 1407 ret = tree->ops->readpage_end_io_hook(page, start, end); 1408 if (ret) 1409 uptodate = 0; 1410 } 1411 if (uptodate) { 1412 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1413 if (whole_page) 1414 SetPageUptodate(page); 1415 else 1416 check_page_uptodate(tree, page); 1417 } else { 1418 ClearPageUptodate(page); 1419 SetPageError(page); 1420 } 1421 1422 unlock_extent(tree, start, end, GFP_ATOMIC); 1423 1424 if (whole_page) 1425 unlock_page(page); 1426 else 1427 check_page_locked(tree, page); 1428 } while (bvec >= bio->bi_io_vec); 1429 1430 bio_put(bio); 1431 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1432 return 0; 1433 #endif 1434 } 1435 1436 /* 1437 * IO done from prepare_write is pretty simple, we just unlock 1438 * the structs in the extent tree when done, and set the uptodate bits 1439 * as appropriate. 1440 */ 1441 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1442 static void end_bio_extent_preparewrite(struct bio *bio, int err) 1443 #else 1444 static int end_bio_extent_preparewrite(struct bio *bio, 1445 unsigned int bytes_done, int err) 1446 #endif 1447 { 1448 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1449 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1450 struct extent_map_tree *tree = bio->bi_private; 1451 u64 start; 1452 u64 end; 1453 1454 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1455 if (bio->bi_size) 1456 return 1; 1457 #endif 1458 1459 do { 1460 struct page *page = bvec->bv_page; 1461 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1462 bvec->bv_offset; 1463 end = start + bvec->bv_len - 1; 1464 1465 if (--bvec >= bio->bi_io_vec) 1466 prefetchw(&bvec->bv_page->flags); 1467 1468 if (uptodate) { 1469 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1470 } else { 1471 ClearPageUptodate(page); 1472 SetPageError(page); 1473 } 1474 1475 unlock_extent(tree, start, end, GFP_ATOMIC); 1476 1477 } while (bvec >= bio->bi_io_vec); 1478 1479 bio_put(bio); 1480 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1481 return 0; 1482 #endif 1483 } 1484 1485 static struct bio * 1486 extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, 1487 gfp_t gfp_flags) 1488 { 1489 struct bio *bio; 1490 1491 bio = bio_alloc(gfp_flags, nr_vecs); 1492 1493 if (bio == NULL && (current->flags & PF_MEMALLOC)) { 1494 while (!bio && (nr_vecs /= 2)) 1495 bio = bio_alloc(gfp_flags, nr_vecs); 1496 } 1497 1498 if (bio) { 1499 bio->bi_bdev = bdev; 1500 bio->bi_sector = first_sector; 1501 } 1502 return bio; 1503 } 1504 1505 static int submit_one_bio(int rw, struct bio *bio) 1506 { 1507 int ret = 0; 1508 bio_get(bio); 1509 submit_bio(rw, bio); 1510 if (bio_flagged(bio, BIO_EOPNOTSUPP)) 1511 ret = -EOPNOTSUPP; 1512 bio_put(bio); 1513 return ret; 1514 } 1515 1516 static int submit_extent_page(int rw, struct extent_map_tree *tree, 1517 struct page *page, sector_t sector, 1518 size_t size, unsigned long offset, 1519 struct block_device *bdev, 1520 struct bio **bio_ret, 1521 unsigned long max_pages, 1522 bio_end_io_t end_io_func) 1523 { 1524 int ret = 0; 1525 struct bio *bio; 1526 int nr; 1527 1528 if (bio_ret && *bio_ret) { 1529 bio = *bio_ret; 1530 if (bio->bi_sector + (bio->bi_size >> 9) != sector || 1531 bio_add_page(bio, page, size, offset) < size) { 1532 ret = submit_one_bio(rw, bio); 1533 bio = NULL; 1534 } else { 1535 return 0; 1536 } 1537 } 1538 nr = min_t(int, max_pages, bio_get_nr_vecs(bdev)); 1539 bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH); 1540 if (!bio) { 1541 printk("failed to allocate bio nr %d\n", nr); 1542 } 1543 bio_add_page(bio, page, size, offset); 1544 bio->bi_end_io = end_io_func; 1545 bio->bi_private = tree; 1546 if (bio_ret) { 1547 *bio_ret = bio; 1548 } else { 1549 ret = submit_one_bio(rw, bio); 1550 } 1551 1552 return ret; 1553 } 1554 1555 void set_page_extent_mapped(struct page *page) 1556 { 1557 if (!PagePrivate(page)) { 1558 SetPagePrivate(page); 1559 WARN_ON(!page->mapping->a_ops->invalidatepage); 1560 set_page_private(page, EXTENT_PAGE_PRIVATE); 1561 page_cache_get(page); 1562 } 1563 } 1564 1565 /* 1566 * basic readpage implementation. Locked extent state structs are inserted 1567 * into the tree that are removed when the IO is done (by the end_io 1568 * handlers) 1569 */ 1570 static int __extent_read_full_page(struct extent_map_tree *tree, 1571 struct page *page, 1572 get_extent_t *get_extent, 1573 struct bio **bio) 1574 { 1575 struct inode *inode = page->mapping->host; 1576 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1577 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1578 u64 end; 1579 u64 cur = start; 1580 u64 extent_offset; 1581 u64 last_byte = i_size_read(inode); 1582 u64 block_start; 1583 u64 cur_end; 1584 sector_t sector; 1585 struct extent_map *em; 1586 struct block_device *bdev; 1587 int ret; 1588 int nr = 0; 1589 size_t page_offset = 0; 1590 size_t iosize; 1591 size_t blocksize = inode->i_sb->s_blocksize; 1592 1593 set_page_extent_mapped(page); 1594 1595 end = page_end; 1596 lock_extent(tree, start, end, GFP_NOFS); 1597 1598 while (cur <= end) { 1599 if (cur >= last_byte) { 1600 iosize = PAGE_CACHE_SIZE - page_offset; 1601 zero_user_page(page, page_offset, iosize, KM_USER0); 1602 set_extent_uptodate(tree, cur, cur + iosize - 1, 1603 GFP_NOFS); 1604 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1605 break; 1606 } 1607 em = get_extent(inode, page, page_offset, cur, end, 0); 1608 if (IS_ERR(em) || !em) { 1609 SetPageError(page); 1610 unlock_extent(tree, cur, end, GFP_NOFS); 1611 break; 1612 } 1613 1614 extent_offset = cur - em->start; 1615 BUG_ON(em->end < cur); 1616 BUG_ON(end < cur); 1617 1618 iosize = min(em->end - cur, end - cur) + 1; 1619 cur_end = min(em->end, end); 1620 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1621 sector = (em->block_start + extent_offset) >> 9; 1622 bdev = em->bdev; 1623 block_start = em->block_start; 1624 free_extent_map(em); 1625 em = NULL; 1626 1627 /* we've found a hole, just zero and go on */ 1628 if (block_start == EXTENT_MAP_HOLE) { 1629 zero_user_page(page, page_offset, iosize, KM_USER0); 1630 set_extent_uptodate(tree, cur, cur + iosize - 1, 1631 GFP_NOFS); 1632 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1633 cur = cur + iosize; 1634 page_offset += iosize; 1635 continue; 1636 } 1637 /* the get_extent function already copied into the page */ 1638 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { 1639 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1640 cur = cur + iosize; 1641 page_offset += iosize; 1642 continue; 1643 } 1644 1645 ret = 0; 1646 if (tree->ops && tree->ops->readpage_io_hook) { 1647 ret = tree->ops->readpage_io_hook(page, cur, 1648 cur + iosize - 1); 1649 } 1650 if (!ret) { 1651 unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1; 1652 nr -= page->index; 1653 ret = submit_extent_page(READ, tree, page, 1654 sector, iosize, page_offset, 1655 bdev, bio, nr, 1656 end_bio_extent_readpage); 1657 } 1658 if (ret) 1659 SetPageError(page); 1660 cur = cur + iosize; 1661 page_offset += iosize; 1662 nr++; 1663 } 1664 if (!nr) { 1665 if (!PageError(page)) 1666 SetPageUptodate(page); 1667 unlock_page(page); 1668 } 1669 return 0; 1670 } 1671 1672 int extent_read_full_page(struct extent_map_tree *tree, struct page *page, 1673 get_extent_t *get_extent) 1674 { 1675 struct bio *bio = NULL; 1676 int ret; 1677 1678 ret = __extent_read_full_page(tree, page, get_extent, &bio); 1679 if (bio) 1680 submit_one_bio(READ, bio); 1681 return ret; 1682 } 1683 EXPORT_SYMBOL(extent_read_full_page); 1684 1685 /* 1686 * the writepage semantics are similar to regular writepage. extent 1687 * records are inserted to lock ranges in the tree, and as dirty areas 1688 * are found, they are marked writeback. Then the lock bits are removed 1689 * and the end_io handler clears the writeback ranges 1690 */ 1691 static int __extent_writepage(struct page *page, struct writeback_control *wbc, 1692 void *data) 1693 { 1694 struct inode *inode = page->mapping->host; 1695 struct extent_page_data *epd = data; 1696 struct extent_map_tree *tree = epd->tree; 1697 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1698 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1699 u64 end; 1700 u64 cur = start; 1701 u64 extent_offset; 1702 u64 last_byte = i_size_read(inode); 1703 u64 block_start; 1704 u64 iosize; 1705 sector_t sector; 1706 struct extent_map *em; 1707 struct block_device *bdev; 1708 int ret; 1709 int nr = 0; 1710 size_t page_offset = 0; 1711 size_t blocksize; 1712 loff_t i_size = i_size_read(inode); 1713 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; 1714 u64 nr_delalloc; 1715 u64 delalloc_end; 1716 1717 WARN_ON(!PageLocked(page)); 1718 if (page->index > end_index) { 1719 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1720 unlock_page(page); 1721 return 0; 1722 } 1723 1724 if (page->index == end_index) { 1725 size_t offset = i_size & (PAGE_CACHE_SIZE - 1); 1726 zero_user_page(page, offset, 1727 PAGE_CACHE_SIZE - offset, KM_USER0); 1728 } 1729 1730 set_page_extent_mapped(page); 1731 1732 lock_extent(tree, start, page_end, GFP_NOFS); 1733 nr_delalloc = find_lock_delalloc_range(tree, start, page_end + 1, 1734 &delalloc_end, 1735 128 * 1024 * 1024); 1736 if (nr_delalloc) { 1737 tree->ops->fill_delalloc(inode, start, delalloc_end); 1738 if (delalloc_end >= page_end + 1) { 1739 clear_extent_bit(tree, page_end + 1, delalloc_end, 1740 EXTENT_LOCKED | EXTENT_DELALLOC, 1741 1, 0, GFP_NOFS); 1742 } 1743 clear_extent_bit(tree, start, page_end, EXTENT_DELALLOC, 1744 0, 0, GFP_NOFS); 1745 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1746 printk("found delalloc bits after clear extent_bit\n"); 1747 } 1748 } else if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1749 printk("found delalloc bits after find_delalloc_range returns 0\n"); 1750 } 1751 1752 end = page_end; 1753 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1754 printk("found delalloc bits after lock_extent\n"); 1755 } 1756 1757 if (last_byte <= start) { 1758 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1759 goto done; 1760 } 1761 1762 set_extent_uptodate(tree, start, page_end, GFP_NOFS); 1763 blocksize = inode->i_sb->s_blocksize; 1764 1765 while (cur <= end) { 1766 if (cur >= last_byte) { 1767 clear_extent_dirty(tree, cur, page_end, GFP_NOFS); 1768 break; 1769 } 1770 em = epd->get_extent(inode, page, page_offset, cur, end, 1); 1771 if (IS_ERR(em) || !em) { 1772 SetPageError(page); 1773 break; 1774 } 1775 1776 extent_offset = cur - em->start; 1777 BUG_ON(em->end < cur); 1778 BUG_ON(end < cur); 1779 iosize = min(em->end - cur, end - cur) + 1; 1780 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1781 sector = (em->block_start + extent_offset) >> 9; 1782 bdev = em->bdev; 1783 block_start = em->block_start; 1784 free_extent_map(em); 1785 em = NULL; 1786 1787 if (block_start == EXTENT_MAP_HOLE || 1788 block_start == EXTENT_MAP_INLINE) { 1789 clear_extent_dirty(tree, cur, 1790 cur + iosize - 1, GFP_NOFS); 1791 cur = cur + iosize; 1792 page_offset += iosize; 1793 continue; 1794 } 1795 1796 /* leave this out until we have a page_mkwrite call */ 1797 if (0 && !test_range_bit(tree, cur, cur + iosize - 1, 1798 EXTENT_DIRTY, 0)) { 1799 cur = cur + iosize; 1800 page_offset += iosize; 1801 continue; 1802 } 1803 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); 1804 if (tree->ops && tree->ops->writepage_io_hook) { 1805 ret = tree->ops->writepage_io_hook(page, cur, 1806 cur + iosize - 1); 1807 } else { 1808 ret = 0; 1809 } 1810 if (ret) 1811 SetPageError(page); 1812 else { 1813 unsigned long nr = end_index + 1; 1814 set_range_writeback(tree, cur, cur + iosize - 1); 1815 1816 ret = submit_extent_page(WRITE, tree, page, sector, 1817 iosize, page_offset, bdev, 1818 &epd->bio, nr, 1819 end_bio_extent_writepage); 1820 if (ret) 1821 SetPageError(page); 1822 } 1823 cur = cur + iosize; 1824 page_offset += iosize; 1825 nr++; 1826 } 1827 done: 1828 unlock_extent(tree, start, page_end, GFP_NOFS); 1829 unlock_page(page); 1830 return 0; 1831 } 1832 1833 int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 1834 get_extent_t *get_extent, 1835 struct writeback_control *wbc) 1836 { 1837 int ret; 1838 struct extent_page_data epd = { 1839 .bio = NULL, 1840 .tree = tree, 1841 .get_extent = get_extent, 1842 }; 1843 1844 ret = __extent_writepage(page, wbc, &epd); 1845 if (epd.bio) 1846 submit_one_bio(WRITE, epd.bio); 1847 return ret; 1848 } 1849 EXPORT_SYMBOL(extent_write_full_page); 1850 1851 int extent_writepages(struct extent_map_tree *tree, 1852 struct address_space *mapping, 1853 get_extent_t *get_extent, 1854 struct writeback_control *wbc) 1855 { 1856 int ret; 1857 struct extent_page_data epd = { 1858 .bio = NULL, 1859 .tree = tree, 1860 .get_extent = get_extent, 1861 }; 1862 1863 ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd); 1864 if (epd.bio) 1865 submit_one_bio(WRITE, epd.bio); 1866 return ret; 1867 } 1868 EXPORT_SYMBOL(extent_writepages); 1869 1870 int extent_readpages(struct extent_map_tree *tree, 1871 struct address_space *mapping, 1872 struct list_head *pages, unsigned nr_pages, 1873 get_extent_t get_extent) 1874 { 1875 struct bio *bio = NULL; 1876 unsigned page_idx; 1877 struct pagevec pvec; 1878 1879 pagevec_init(&pvec, 0); 1880 for (page_idx = 0; page_idx < nr_pages; page_idx++) { 1881 struct page *page = list_entry(pages->prev, struct page, lru); 1882 1883 prefetchw(&page->flags); 1884 list_del(&page->lru); 1885 /* 1886 * what we want to do here is call add_to_page_cache_lru, 1887 * but that isn't exported, so we reproduce it here 1888 */ 1889 if (!add_to_page_cache(page, mapping, 1890 page->index, GFP_KERNEL)) { 1891 1892 /* open coding of lru_cache_add, also not exported */ 1893 page_cache_get(page); 1894 if (!pagevec_add(&pvec, page)) 1895 __pagevec_lru_add(&pvec); 1896 __extent_read_full_page(tree, page, get_extent, &bio); 1897 } 1898 page_cache_release(page); 1899 } 1900 if (pagevec_count(&pvec)) 1901 __pagevec_lru_add(&pvec); 1902 BUG_ON(!list_empty(pages)); 1903 if (bio) 1904 submit_one_bio(READ, bio); 1905 return 0; 1906 } 1907 EXPORT_SYMBOL(extent_readpages); 1908 1909 /* 1910 * basic invalidatepage code, this waits on any locked or writeback 1911 * ranges corresponding to the page, and then deletes any extent state 1912 * records from the tree 1913 */ 1914 int extent_invalidatepage(struct extent_map_tree *tree, 1915 struct page *page, unsigned long offset) 1916 { 1917 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT); 1918 u64 end = start + PAGE_CACHE_SIZE - 1; 1919 size_t blocksize = page->mapping->host->i_sb->s_blocksize; 1920 1921 start += (offset + blocksize -1) & ~(blocksize - 1); 1922 if (start > end) 1923 return 0; 1924 1925 lock_extent(tree, start, end, GFP_NOFS); 1926 wait_on_extent_writeback(tree, start, end); 1927 clear_extent_bit(tree, start, end, 1928 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, 1929 1, 1, GFP_NOFS); 1930 return 0; 1931 } 1932 EXPORT_SYMBOL(extent_invalidatepage); 1933 1934 /* 1935 * simple commit_write call, set_range_dirty is used to mark both 1936 * the pages and the extent records as dirty 1937 */ 1938 int extent_commit_write(struct extent_map_tree *tree, 1939 struct inode *inode, struct page *page, 1940 unsigned from, unsigned to) 1941 { 1942 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; 1943 1944 set_page_extent_mapped(page); 1945 set_page_dirty(page); 1946 1947 if (pos > inode->i_size) { 1948 i_size_write(inode, pos); 1949 mark_inode_dirty(inode); 1950 } 1951 return 0; 1952 } 1953 EXPORT_SYMBOL(extent_commit_write); 1954 1955 int extent_prepare_write(struct extent_map_tree *tree, 1956 struct inode *inode, struct page *page, 1957 unsigned from, unsigned to, get_extent_t *get_extent) 1958 { 1959 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 1960 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 1961 u64 block_start; 1962 u64 orig_block_start; 1963 u64 block_end; 1964 u64 cur_end; 1965 struct extent_map *em; 1966 unsigned blocksize = 1 << inode->i_blkbits; 1967 size_t page_offset = 0; 1968 size_t block_off_start; 1969 size_t block_off_end; 1970 int err = 0; 1971 int iocount = 0; 1972 int ret = 0; 1973 int isnew; 1974 1975 set_page_extent_mapped(page); 1976 1977 block_start = (page_start + from) & ~((u64)blocksize - 1); 1978 block_end = (page_start + to - 1) | (blocksize - 1); 1979 orig_block_start = block_start; 1980 1981 lock_extent(tree, page_start, page_end, GFP_NOFS); 1982 while(block_start <= block_end) { 1983 em = get_extent(inode, page, page_offset, block_start, 1984 block_end, 1); 1985 if (IS_ERR(em) || !em) { 1986 goto err; 1987 } 1988 cur_end = min(block_end, em->end); 1989 block_off_start = block_start & (PAGE_CACHE_SIZE - 1); 1990 block_off_end = block_off_start + blocksize; 1991 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); 1992 1993 if (!PageUptodate(page) && isnew && 1994 (block_off_end > to || block_off_start < from)) { 1995 void *kaddr; 1996 1997 kaddr = kmap_atomic(page, KM_USER0); 1998 if (block_off_end > to) 1999 memset(kaddr + to, 0, block_off_end - to); 2000 if (block_off_start < from) 2001 memset(kaddr + block_off_start, 0, 2002 from - block_off_start); 2003 flush_dcache_page(page); 2004 kunmap_atomic(kaddr, KM_USER0); 2005 } 2006 if (!isnew && !PageUptodate(page) && 2007 (block_off_end > to || block_off_start < from) && 2008 !test_range_bit(tree, block_start, cur_end, 2009 EXTENT_UPTODATE, 1)) { 2010 u64 sector; 2011 u64 extent_offset = block_start - em->start; 2012 size_t iosize; 2013 sector = (em->block_start + extent_offset) >> 9; 2014 iosize = (cur_end - block_start + blocksize - 1) & 2015 ~((u64)blocksize - 1); 2016 /* 2017 * we've already got the extent locked, but we 2018 * need to split the state such that our end_bio 2019 * handler can clear the lock. 2020 */ 2021 set_extent_bit(tree, block_start, 2022 block_start + iosize - 1, 2023 EXTENT_LOCKED, 0, NULL, GFP_NOFS); 2024 ret = submit_extent_page(READ, tree, page, 2025 sector, iosize, page_offset, em->bdev, 2026 NULL, 1, 2027 end_bio_extent_preparewrite); 2028 iocount++; 2029 block_start = block_start + iosize; 2030 } else { 2031 set_extent_uptodate(tree, block_start, cur_end, 2032 GFP_NOFS); 2033 unlock_extent(tree, block_start, cur_end, GFP_NOFS); 2034 block_start = cur_end + 1; 2035 } 2036 page_offset = block_start & (PAGE_CACHE_SIZE - 1); 2037 free_extent_map(em); 2038 } 2039 if (iocount) { 2040 wait_extent_bit(tree, orig_block_start, 2041 block_end, EXTENT_LOCKED); 2042 } 2043 check_page_uptodate(tree, page); 2044 err: 2045 /* FIXME, zero out newly allocated blocks on error */ 2046 return err; 2047 } 2048 EXPORT_SYMBOL(extent_prepare_write); 2049 2050 /* 2051 * a helper for releasepage. As long as there are no locked extents 2052 * in the range corresponding to the page, both state records and extent 2053 * map records are removed 2054 */ 2055 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) 2056 { 2057 struct extent_map *em; 2058 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 2059 u64 end = start + PAGE_CACHE_SIZE - 1; 2060 u64 orig_start = start; 2061 int ret = 1; 2062 2063 while (start <= end) { 2064 em = lookup_extent_mapping(tree, start, end); 2065 if (!em || IS_ERR(em)) 2066 break; 2067 if (!test_range_bit(tree, em->start, em->end, 2068 EXTENT_LOCKED, 0)) { 2069 remove_extent_mapping(tree, em); 2070 /* once for the rb tree */ 2071 free_extent_map(em); 2072 } 2073 start = em->end + 1; 2074 /* once for us */ 2075 free_extent_map(em); 2076 } 2077 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) 2078 ret = 0; 2079 else 2080 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, 2081 1, 1, GFP_NOFS); 2082 return ret; 2083 } 2084 EXPORT_SYMBOL(try_release_extent_mapping); 2085 2086 sector_t extent_bmap(struct address_space *mapping, sector_t iblock, 2087 get_extent_t *get_extent) 2088 { 2089 struct inode *inode = mapping->host; 2090 u64 start = iblock << inode->i_blkbits; 2091 u64 end = start + (1 << inode->i_blkbits) - 1; 2092 sector_t sector = 0; 2093 struct extent_map *em; 2094 2095 em = get_extent(inode, NULL, 0, start, end, 0); 2096 if (!em || IS_ERR(em)) 2097 return 0; 2098 2099 if (em->block_start == EXTENT_MAP_INLINE || 2100 em->block_start == EXTENT_MAP_HOLE) 2101 goto out; 2102 2103 sector = (em->block_start + start - em->start) >> inode->i_blkbits; 2104 out: 2105 free_extent_map(em); 2106 return sector; 2107 } 2108 2109 static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb) 2110 { 2111 if (list_empty(&eb->lru)) { 2112 extent_buffer_get(eb); 2113 list_add(&eb->lru, &tree->buffer_lru); 2114 tree->lru_size++; 2115 if (tree->lru_size >= BUFFER_LRU_MAX) { 2116 struct extent_buffer *rm; 2117 rm = list_entry(tree->buffer_lru.prev, 2118 struct extent_buffer, lru); 2119 tree->lru_size--; 2120 list_del_init(&rm->lru); 2121 free_extent_buffer(rm); 2122 } 2123 } else 2124 list_move(&eb->lru, &tree->buffer_lru); 2125 return 0; 2126 } 2127 static struct extent_buffer *find_lru(struct extent_map_tree *tree, 2128 u64 start, unsigned long len) 2129 { 2130 struct list_head *lru = &tree->buffer_lru; 2131 struct list_head *cur = lru->next; 2132 struct extent_buffer *eb; 2133 2134 if (list_empty(lru)) 2135 return NULL; 2136 2137 do { 2138 eb = list_entry(cur, struct extent_buffer, lru); 2139 if (eb->start == start && eb->len == len) { 2140 extent_buffer_get(eb); 2141 return eb; 2142 } 2143 cur = cur->next; 2144 } while (cur != lru); 2145 return NULL; 2146 } 2147 2148 static inline unsigned long num_extent_pages(u64 start, u64 len) 2149 { 2150 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - 2151 (start >> PAGE_CACHE_SHIFT); 2152 } 2153 2154 static inline struct page *extent_buffer_page(struct extent_buffer *eb, 2155 unsigned long i) 2156 { 2157 struct page *p; 2158 struct address_space *mapping; 2159 2160 if (i == 0) 2161 return eb->first_page; 2162 i += eb->start >> PAGE_CACHE_SHIFT; 2163 mapping = eb->first_page->mapping; 2164 read_lock_irq(&mapping->tree_lock); 2165 p = radix_tree_lookup(&mapping->page_tree, i); 2166 read_unlock_irq(&mapping->tree_lock); 2167 return p; 2168 } 2169 2170 static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, 2171 u64 start, 2172 unsigned long len, 2173 gfp_t mask) 2174 { 2175 struct extent_buffer *eb = NULL; 2176 2177 spin_lock(&tree->lru_lock); 2178 eb = find_lru(tree, start, len); 2179 spin_unlock(&tree->lru_lock); 2180 if (eb) { 2181 return eb; 2182 } 2183 2184 eb = kmem_cache_zalloc(extent_buffer_cache, mask); 2185 INIT_LIST_HEAD(&eb->lru); 2186 eb->start = start; 2187 eb->len = len; 2188 atomic_set(&eb->refs, 1); 2189 2190 return eb; 2191 } 2192 2193 static void __free_extent_buffer(struct extent_buffer *eb) 2194 { 2195 kmem_cache_free(extent_buffer_cache, eb); 2196 } 2197 2198 struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 2199 u64 start, unsigned long len, 2200 struct page *page0, 2201 gfp_t mask) 2202 { 2203 unsigned long num_pages = num_extent_pages(start, len); 2204 unsigned long i; 2205 unsigned long index = start >> PAGE_CACHE_SHIFT; 2206 struct extent_buffer *eb; 2207 struct page *p; 2208 struct address_space *mapping = tree->mapping; 2209 int uptodate = 1; 2210 2211 eb = __alloc_extent_buffer(tree, start, len, mask); 2212 if (!eb || IS_ERR(eb)) 2213 return NULL; 2214 2215 if (eb->flags & EXTENT_BUFFER_FILLED) 2216 goto lru_add; 2217 2218 if (page0) { 2219 eb->first_page = page0; 2220 i = 1; 2221 index++; 2222 page_cache_get(page0); 2223 mark_page_accessed(page0); 2224 set_page_extent_mapped(page0); 2225 WARN_ON(!PageUptodate(page0)); 2226 set_page_private(page0, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2227 len << 2); 2228 } else { 2229 i = 0; 2230 } 2231 for (; i < num_pages; i++, index++) { 2232 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM); 2233 if (!p) { 2234 WARN_ON(1); 2235 goto fail; 2236 } 2237 set_page_extent_mapped(p); 2238 mark_page_accessed(p); 2239 if (i == 0) { 2240 eb->first_page = p; 2241 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2242 len << 2); 2243 } else { 2244 set_page_private(p, EXTENT_PAGE_PRIVATE); 2245 } 2246 if (!PageUptodate(p)) 2247 uptodate = 0; 2248 unlock_page(p); 2249 } 2250 if (uptodate) 2251 eb->flags |= EXTENT_UPTODATE; 2252 eb->flags |= EXTENT_BUFFER_FILLED; 2253 2254 lru_add: 2255 spin_lock(&tree->lru_lock); 2256 add_lru(tree, eb); 2257 spin_unlock(&tree->lru_lock); 2258 return eb; 2259 2260 fail: 2261 spin_lock(&tree->lru_lock); 2262 list_del_init(&eb->lru); 2263 spin_unlock(&tree->lru_lock); 2264 if (!atomic_dec_and_test(&eb->refs)) 2265 return NULL; 2266 for (index = 1; index < i; index++) { 2267 page_cache_release(extent_buffer_page(eb, index)); 2268 } 2269 if (i > 0) 2270 page_cache_release(extent_buffer_page(eb, 0)); 2271 __free_extent_buffer(eb); 2272 return NULL; 2273 } 2274 EXPORT_SYMBOL(alloc_extent_buffer); 2275 2276 struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 2277 u64 start, unsigned long len, 2278 gfp_t mask) 2279 { 2280 unsigned long num_pages = num_extent_pages(start, len); 2281 unsigned long i; 2282 unsigned long index = start >> PAGE_CACHE_SHIFT; 2283 struct extent_buffer *eb; 2284 struct page *p; 2285 struct address_space *mapping = tree->mapping; 2286 int uptodate = 1; 2287 2288 eb = __alloc_extent_buffer(tree, start, len, mask); 2289 if (!eb || IS_ERR(eb)) 2290 return NULL; 2291 2292 if (eb->flags & EXTENT_BUFFER_FILLED) 2293 goto lru_add; 2294 2295 for (i = 0; i < num_pages; i++, index++) { 2296 p = find_lock_page(mapping, index); 2297 if (!p) { 2298 goto fail; 2299 } 2300 set_page_extent_mapped(p); 2301 mark_page_accessed(p); 2302 2303 if (i == 0) { 2304 eb->first_page = p; 2305 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2306 len << 2); 2307 } else { 2308 set_page_private(p, EXTENT_PAGE_PRIVATE); 2309 } 2310 2311 if (!PageUptodate(p)) 2312 uptodate = 0; 2313 unlock_page(p); 2314 } 2315 if (uptodate) 2316 eb->flags |= EXTENT_UPTODATE; 2317 eb->flags |= EXTENT_BUFFER_FILLED; 2318 2319 lru_add: 2320 spin_lock(&tree->lru_lock); 2321 add_lru(tree, eb); 2322 spin_unlock(&tree->lru_lock); 2323 return eb; 2324 fail: 2325 spin_lock(&tree->lru_lock); 2326 list_del_init(&eb->lru); 2327 spin_unlock(&tree->lru_lock); 2328 if (!atomic_dec_and_test(&eb->refs)) 2329 return NULL; 2330 for (index = 1; index < i; index++) { 2331 page_cache_release(extent_buffer_page(eb, index)); 2332 } 2333 if (i > 0) 2334 page_cache_release(extent_buffer_page(eb, 0)); 2335 __free_extent_buffer(eb); 2336 return NULL; 2337 } 2338 EXPORT_SYMBOL(find_extent_buffer); 2339 2340 void free_extent_buffer(struct extent_buffer *eb) 2341 { 2342 unsigned long i; 2343 unsigned long num_pages; 2344 2345 if (!eb) 2346 return; 2347 2348 if (!atomic_dec_and_test(&eb->refs)) 2349 return; 2350 2351 WARN_ON(!list_empty(&eb->lru)); 2352 num_pages = num_extent_pages(eb->start, eb->len); 2353 2354 for (i = 1; i < num_pages; i++) { 2355 page_cache_release(extent_buffer_page(eb, i)); 2356 } 2357 page_cache_release(extent_buffer_page(eb, 0)); 2358 __free_extent_buffer(eb); 2359 } 2360 EXPORT_SYMBOL(free_extent_buffer); 2361 2362 int clear_extent_buffer_dirty(struct extent_map_tree *tree, 2363 struct extent_buffer *eb) 2364 { 2365 int set; 2366 unsigned long i; 2367 unsigned long num_pages; 2368 struct page *page; 2369 2370 u64 start = eb->start; 2371 u64 end = start + eb->len - 1; 2372 2373 set = clear_extent_dirty(tree, start, end, GFP_NOFS); 2374 num_pages = num_extent_pages(eb->start, eb->len); 2375 2376 for (i = 0; i < num_pages; i++) { 2377 page = extent_buffer_page(eb, i); 2378 lock_page(page); 2379 /* 2380 * if we're on the last page or the first page and the 2381 * block isn't aligned on a page boundary, do extra checks 2382 * to make sure we don't clean page that is partially dirty 2383 */ 2384 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2385 ((i == num_pages - 1) && 2386 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2387 start = (u64)page->index << PAGE_CACHE_SHIFT; 2388 end = start + PAGE_CACHE_SIZE - 1; 2389 if (test_range_bit(tree, start, end, 2390 EXTENT_DIRTY, 0)) { 2391 unlock_page(page); 2392 continue; 2393 } 2394 } 2395 clear_page_dirty_for_io(page); 2396 unlock_page(page); 2397 } 2398 return 0; 2399 } 2400 EXPORT_SYMBOL(clear_extent_buffer_dirty); 2401 2402 int wait_on_extent_buffer_writeback(struct extent_map_tree *tree, 2403 struct extent_buffer *eb) 2404 { 2405 return wait_on_extent_writeback(tree, eb->start, 2406 eb->start + eb->len - 1); 2407 } 2408 EXPORT_SYMBOL(wait_on_extent_buffer_writeback); 2409 2410 int set_extent_buffer_dirty(struct extent_map_tree *tree, 2411 struct extent_buffer *eb) 2412 { 2413 unsigned long i; 2414 unsigned long num_pages; 2415 2416 num_pages = num_extent_pages(eb->start, eb->len); 2417 for (i = 0; i < num_pages; i++) { 2418 struct page *page = extent_buffer_page(eb, i); 2419 /* writepage may need to do something special for the 2420 * first page, we have to make sure page->private is 2421 * properly set. releasepage may drop page->private 2422 * on us if the page isn't already dirty. 2423 */ 2424 if (i == 0) { 2425 lock_page(page); 2426 set_page_private(page, 2427 EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2428 eb->len << 2); 2429 } 2430 __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); 2431 if (i == 0) 2432 unlock_page(page); 2433 } 2434 return set_extent_dirty(tree, eb->start, 2435 eb->start + eb->len - 1, GFP_NOFS); 2436 } 2437 EXPORT_SYMBOL(set_extent_buffer_dirty); 2438 2439 int set_extent_buffer_uptodate(struct extent_map_tree *tree, 2440 struct extent_buffer *eb) 2441 { 2442 unsigned long i; 2443 struct page *page; 2444 unsigned long num_pages; 2445 2446 num_pages = num_extent_pages(eb->start, eb->len); 2447 2448 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, 2449 GFP_NOFS); 2450 for (i = 0; i < num_pages; i++) { 2451 page = extent_buffer_page(eb, i); 2452 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2453 ((i == num_pages - 1) && 2454 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2455 check_page_uptodate(tree, page); 2456 continue; 2457 } 2458 SetPageUptodate(page); 2459 } 2460 return 0; 2461 } 2462 EXPORT_SYMBOL(set_extent_buffer_uptodate); 2463 2464 int extent_buffer_uptodate(struct extent_map_tree *tree, 2465 struct extent_buffer *eb) 2466 { 2467 if (eb->flags & EXTENT_UPTODATE) 2468 return 1; 2469 return test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2470 EXTENT_UPTODATE, 1); 2471 } 2472 EXPORT_SYMBOL(extent_buffer_uptodate); 2473 2474 int read_extent_buffer_pages(struct extent_map_tree *tree, 2475 struct extent_buffer *eb, 2476 u64 start, 2477 int wait) 2478 { 2479 unsigned long i; 2480 unsigned long start_i; 2481 struct page *page; 2482 int err; 2483 int ret = 0; 2484 unsigned long num_pages; 2485 2486 if (eb->flags & EXTENT_UPTODATE) 2487 return 0; 2488 2489 if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2490 EXTENT_UPTODATE, 1)) { 2491 return 0; 2492 } 2493 2494 if (start) { 2495 WARN_ON(start < eb->start); 2496 start_i = (start >> PAGE_CACHE_SHIFT) - 2497 (eb->start >> PAGE_CACHE_SHIFT); 2498 } else { 2499 start_i = 0; 2500 } 2501 2502 num_pages = num_extent_pages(eb->start, eb->len); 2503 for (i = start_i; i < num_pages; i++) { 2504 page = extent_buffer_page(eb, i); 2505 if (PageUptodate(page)) { 2506 continue; 2507 } 2508 if (!wait) { 2509 if (TestSetPageLocked(page)) { 2510 continue; 2511 } 2512 } else { 2513 lock_page(page); 2514 } 2515 if (!PageUptodate(page)) { 2516 err = page->mapping->a_ops->readpage(NULL, page); 2517 if (err) { 2518 ret = err; 2519 } 2520 } else { 2521 unlock_page(page); 2522 } 2523 } 2524 2525 if (ret || !wait) { 2526 return ret; 2527 } 2528 2529 for (i = start_i; i < num_pages; i++) { 2530 page = extent_buffer_page(eb, i); 2531 wait_on_page_locked(page); 2532 if (!PageUptodate(page)) { 2533 ret = -EIO; 2534 } 2535 } 2536 if (!ret) 2537 eb->flags |= EXTENT_UPTODATE; 2538 return ret; 2539 } 2540 EXPORT_SYMBOL(read_extent_buffer_pages); 2541 2542 void read_extent_buffer(struct extent_buffer *eb, void *dstv, 2543 unsigned long start, 2544 unsigned long len) 2545 { 2546 size_t cur; 2547 size_t offset; 2548 struct page *page; 2549 char *kaddr; 2550 char *dst = (char *)dstv; 2551 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2552 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2553 unsigned long num_pages = num_extent_pages(eb->start, eb->len); 2554 2555 WARN_ON(start > eb->len); 2556 WARN_ON(start + len > eb->start + eb->len); 2557 2558 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2559 2560 while(len > 0) { 2561 page = extent_buffer_page(eb, i); 2562 if (!PageUptodate(page)) { 2563 printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); 2564 WARN_ON(1); 2565 } 2566 WARN_ON(!PageUptodate(page)); 2567 2568 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2569 kaddr = kmap_atomic(page, KM_USER1); 2570 memcpy(dst, kaddr + offset, cur); 2571 kunmap_atomic(kaddr, KM_USER1); 2572 2573 dst += cur; 2574 len -= cur; 2575 offset = 0; 2576 i++; 2577 } 2578 } 2579 EXPORT_SYMBOL(read_extent_buffer); 2580 2581 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, 2582 unsigned long min_len, char **token, char **map, 2583 unsigned long *map_start, 2584 unsigned long *map_len, int km) 2585 { 2586 size_t offset = start & (PAGE_CACHE_SIZE - 1); 2587 char *kaddr; 2588 struct page *p; 2589 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2590 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2591 unsigned long end_i = (start_offset + start + min_len - 1) >> 2592 PAGE_CACHE_SHIFT; 2593 2594 if (i != end_i) 2595 return -EINVAL; 2596 2597 if (i == 0) { 2598 offset = start_offset; 2599 *map_start = 0; 2600 } else { 2601 offset = 0; 2602 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset; 2603 } 2604 if (start + min_len > eb->len) { 2605 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); 2606 WARN_ON(1); 2607 } 2608 2609 p = extent_buffer_page(eb, i); 2610 WARN_ON(!PageUptodate(p)); 2611 kaddr = kmap_atomic(p, km); 2612 *token = kaddr; 2613 *map = kaddr + offset; 2614 *map_len = PAGE_CACHE_SIZE - offset; 2615 return 0; 2616 } 2617 EXPORT_SYMBOL(map_private_extent_buffer); 2618 2619 int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 2620 unsigned long min_len, 2621 char **token, char **map, 2622 unsigned long *map_start, 2623 unsigned long *map_len, int km) 2624 { 2625 int err; 2626 int save = 0; 2627 if (eb->map_token) { 2628 unmap_extent_buffer(eb, eb->map_token, km); 2629 eb->map_token = NULL; 2630 save = 1; 2631 } 2632 err = map_private_extent_buffer(eb, start, min_len, token, map, 2633 map_start, map_len, km); 2634 if (!err && save) { 2635 eb->map_token = *token; 2636 eb->kaddr = *map; 2637 eb->map_start = *map_start; 2638 eb->map_len = *map_len; 2639 } 2640 return err; 2641 } 2642 EXPORT_SYMBOL(map_extent_buffer); 2643 2644 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) 2645 { 2646 kunmap_atomic(token, km); 2647 } 2648 EXPORT_SYMBOL(unmap_extent_buffer); 2649 2650 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 2651 unsigned long start, 2652 unsigned long len) 2653 { 2654 size_t cur; 2655 size_t offset; 2656 struct page *page; 2657 char *kaddr; 2658 char *ptr = (char *)ptrv; 2659 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2660 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2661 int ret = 0; 2662 2663 WARN_ON(start > eb->len); 2664 WARN_ON(start + len > eb->start + eb->len); 2665 2666 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2667 2668 while(len > 0) { 2669 page = extent_buffer_page(eb, i); 2670 WARN_ON(!PageUptodate(page)); 2671 2672 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2673 2674 kaddr = kmap_atomic(page, KM_USER0); 2675 ret = memcmp(ptr, kaddr + offset, cur); 2676 kunmap_atomic(kaddr, KM_USER0); 2677 if (ret) 2678 break; 2679 2680 ptr += cur; 2681 len -= cur; 2682 offset = 0; 2683 i++; 2684 } 2685 return ret; 2686 } 2687 EXPORT_SYMBOL(memcmp_extent_buffer); 2688 2689 void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 2690 unsigned long start, unsigned long len) 2691 { 2692 size_t cur; 2693 size_t offset; 2694 struct page *page; 2695 char *kaddr; 2696 char *src = (char *)srcv; 2697 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2698 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2699 2700 WARN_ON(start > eb->len); 2701 WARN_ON(start + len > eb->start + eb->len); 2702 2703 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2704 2705 while(len > 0) { 2706 page = extent_buffer_page(eb, i); 2707 WARN_ON(!PageUptodate(page)); 2708 2709 cur = min(len, PAGE_CACHE_SIZE - offset); 2710 kaddr = kmap_atomic(page, KM_USER1); 2711 memcpy(kaddr + offset, src, cur); 2712 kunmap_atomic(kaddr, KM_USER1); 2713 2714 src += cur; 2715 len -= cur; 2716 offset = 0; 2717 i++; 2718 } 2719 } 2720 EXPORT_SYMBOL(write_extent_buffer); 2721 2722 void memset_extent_buffer(struct extent_buffer *eb, char c, 2723 unsigned long start, unsigned long len) 2724 { 2725 size_t cur; 2726 size_t offset; 2727 struct page *page; 2728 char *kaddr; 2729 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2730 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2731 2732 WARN_ON(start > eb->len); 2733 WARN_ON(start + len > eb->start + eb->len); 2734 2735 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2736 2737 while(len > 0) { 2738 page = extent_buffer_page(eb, i); 2739 WARN_ON(!PageUptodate(page)); 2740 2741 cur = min(len, PAGE_CACHE_SIZE - offset); 2742 kaddr = kmap_atomic(page, KM_USER0); 2743 memset(kaddr + offset, c, cur); 2744 kunmap_atomic(kaddr, KM_USER0); 2745 2746 len -= cur; 2747 offset = 0; 2748 i++; 2749 } 2750 } 2751 EXPORT_SYMBOL(memset_extent_buffer); 2752 2753 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 2754 unsigned long dst_offset, unsigned long src_offset, 2755 unsigned long len) 2756 { 2757 u64 dst_len = dst->len; 2758 size_t cur; 2759 size_t offset; 2760 struct page *page; 2761 char *kaddr; 2762 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2763 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2764 2765 WARN_ON(src->len != dst_len); 2766 2767 offset = (start_offset + dst_offset) & 2768 ((unsigned long)PAGE_CACHE_SIZE - 1); 2769 2770 while(len > 0) { 2771 page = extent_buffer_page(dst, i); 2772 WARN_ON(!PageUptodate(page)); 2773 2774 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset)); 2775 2776 kaddr = kmap_atomic(page, KM_USER0); 2777 read_extent_buffer(src, kaddr + offset, src_offset, cur); 2778 kunmap_atomic(kaddr, KM_USER0); 2779 2780 src_offset += cur; 2781 len -= cur; 2782 offset = 0; 2783 i++; 2784 } 2785 } 2786 EXPORT_SYMBOL(copy_extent_buffer); 2787 2788 static void move_pages(struct page *dst_page, struct page *src_page, 2789 unsigned long dst_off, unsigned long src_off, 2790 unsigned long len) 2791 { 2792 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2793 if (dst_page == src_page) { 2794 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len); 2795 } else { 2796 char *src_kaddr = kmap_atomic(src_page, KM_USER1); 2797 char *p = dst_kaddr + dst_off + len; 2798 char *s = src_kaddr + src_off + len; 2799 2800 while (len--) 2801 *--p = *--s; 2802 2803 kunmap_atomic(src_kaddr, KM_USER1); 2804 } 2805 kunmap_atomic(dst_kaddr, KM_USER0); 2806 } 2807 2808 static void copy_pages(struct page *dst_page, struct page *src_page, 2809 unsigned long dst_off, unsigned long src_off, 2810 unsigned long len) 2811 { 2812 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2813 char *src_kaddr; 2814 2815 if (dst_page != src_page) 2816 src_kaddr = kmap_atomic(src_page, KM_USER1); 2817 else 2818 src_kaddr = dst_kaddr; 2819 2820 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); 2821 kunmap_atomic(dst_kaddr, KM_USER0); 2822 if (dst_page != src_page) 2823 kunmap_atomic(src_kaddr, KM_USER1); 2824 } 2825 2826 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2827 unsigned long src_offset, unsigned long len) 2828 { 2829 size_t cur; 2830 size_t dst_off_in_page; 2831 size_t src_off_in_page; 2832 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2833 unsigned long dst_i; 2834 unsigned long src_i; 2835 2836 if (src_offset + len > dst->len) { 2837 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2838 src_offset, len, dst->len); 2839 BUG_ON(1); 2840 } 2841 if (dst_offset + len > dst->len) { 2842 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2843 dst_offset, len, dst->len); 2844 BUG_ON(1); 2845 } 2846 2847 while(len > 0) { 2848 dst_off_in_page = (start_offset + dst_offset) & 2849 ((unsigned long)PAGE_CACHE_SIZE - 1); 2850 src_off_in_page = (start_offset + src_offset) & 2851 ((unsigned long)PAGE_CACHE_SIZE - 1); 2852 2853 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2854 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT; 2855 2856 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - 2857 src_off_in_page)); 2858 cur = min_t(unsigned long, cur, 2859 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page)); 2860 2861 copy_pages(extent_buffer_page(dst, dst_i), 2862 extent_buffer_page(dst, src_i), 2863 dst_off_in_page, src_off_in_page, cur); 2864 2865 src_offset += cur; 2866 dst_offset += cur; 2867 len -= cur; 2868 } 2869 } 2870 EXPORT_SYMBOL(memcpy_extent_buffer); 2871 2872 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2873 unsigned long src_offset, unsigned long len) 2874 { 2875 size_t cur; 2876 size_t dst_off_in_page; 2877 size_t src_off_in_page; 2878 unsigned long dst_end = dst_offset + len - 1; 2879 unsigned long src_end = src_offset + len - 1; 2880 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2881 unsigned long dst_i; 2882 unsigned long src_i; 2883 2884 if (src_offset + len > dst->len) { 2885 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2886 src_offset, len, dst->len); 2887 BUG_ON(1); 2888 } 2889 if (dst_offset + len > dst->len) { 2890 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2891 dst_offset, len, dst->len); 2892 BUG_ON(1); 2893 } 2894 if (dst_offset < src_offset) { 2895 memcpy_extent_buffer(dst, dst_offset, src_offset, len); 2896 return; 2897 } 2898 while(len > 0) { 2899 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT; 2900 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT; 2901 2902 dst_off_in_page = (start_offset + dst_end) & 2903 ((unsigned long)PAGE_CACHE_SIZE - 1); 2904 src_off_in_page = (start_offset + src_end) & 2905 ((unsigned long)PAGE_CACHE_SIZE - 1); 2906 2907 cur = min_t(unsigned long, len, src_off_in_page + 1); 2908 cur = min(cur, dst_off_in_page + 1); 2909 move_pages(extent_buffer_page(dst, dst_i), 2910 extent_buffer_page(dst, src_i), 2911 dst_off_in_page - cur + 1, 2912 src_off_in_page - cur + 1, cur); 2913 2914 dst_end -= cur; 2915 src_end -= cur; 2916 len -= cur; 2917 } 2918 } 2919 EXPORT_SYMBOL(memmove_extent_buffer); 2920