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 *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 (found && state->start != cur_start) { 1058 goto out; 1059 } 1060 if (!(state->state & EXTENT_DELALLOC)) { 1061 goto out; 1062 } 1063 if (!found) { 1064 struct extent_state *prev_state; 1065 struct rb_node *prev_node = node; 1066 while(1) { 1067 prev_node = rb_prev(prev_node); 1068 if (!prev_node) 1069 break; 1070 prev_state = rb_entry(prev_node, 1071 struct extent_state, 1072 rb_node); 1073 if (!(prev_state->state & EXTENT_DELALLOC)) 1074 break; 1075 state = prev_state; 1076 node = prev_node; 1077 } 1078 } 1079 if (state->state & EXTENT_LOCKED) { 1080 DEFINE_WAIT(wait); 1081 atomic_inc(&state->refs); 1082 prepare_to_wait(&state->wq, &wait, 1083 TASK_UNINTERRUPTIBLE); 1084 write_unlock_irq(&tree->lock); 1085 schedule(); 1086 write_lock_irq(&tree->lock); 1087 finish_wait(&state->wq, &wait); 1088 free_extent_state(state); 1089 goto search_again; 1090 } 1091 state->state |= EXTENT_LOCKED; 1092 if (!found) 1093 *start = state->start; 1094 found++; 1095 *end = state->end; 1096 cur_start = state->end + 1; 1097 node = rb_next(node); 1098 if (!node) 1099 break; 1100 total_bytes += state->end - state->start + 1; 1101 if (total_bytes >= max_bytes) 1102 break; 1103 } 1104 out: 1105 write_unlock_irq(&tree->lock); 1106 return found; 1107 } 1108 1109 u64 count_range_bits(struct extent_map_tree *tree, 1110 u64 *start, u64 max_bytes, unsigned long bits) 1111 { 1112 struct rb_node *node; 1113 struct extent_state *state; 1114 u64 cur_start = *start; 1115 u64 total_bytes = 0; 1116 int found = 0; 1117 1118 write_lock_irq(&tree->lock); 1119 /* 1120 * this search will find all the extents that end after 1121 * our range starts. 1122 */ 1123 node = tree_search(&tree->state, cur_start); 1124 if (!node || IS_ERR(node)) { 1125 goto out; 1126 } 1127 1128 while(1) { 1129 state = rb_entry(node, struct extent_state, rb_node); 1130 if ((state->state & bits)) { 1131 total_bytes += state->end - state->start + 1; 1132 if (total_bytes >= max_bytes) 1133 break; 1134 if (!found) { 1135 *start = state->start; 1136 found = 1; 1137 } 1138 } 1139 node = rb_next(node); 1140 if (!node) 1141 break; 1142 } 1143 out: 1144 write_unlock_irq(&tree->lock); 1145 return total_bytes; 1146 } 1147 1148 /* 1149 * helper function to lock both pages and extents in the tree. 1150 * pages must be locked first. 1151 */ 1152 int lock_range(struct extent_map_tree *tree, u64 start, u64 end) 1153 { 1154 unsigned long index = start >> PAGE_CACHE_SHIFT; 1155 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1156 struct page *page; 1157 int err; 1158 1159 while (index <= end_index) { 1160 page = grab_cache_page(tree->mapping, index); 1161 if (!page) { 1162 err = -ENOMEM; 1163 goto failed; 1164 } 1165 if (IS_ERR(page)) { 1166 err = PTR_ERR(page); 1167 goto failed; 1168 } 1169 index++; 1170 } 1171 lock_extent(tree, start, end, GFP_NOFS); 1172 return 0; 1173 1174 failed: 1175 /* 1176 * we failed above in getting the page at 'index', so we undo here 1177 * up to but not including the page at 'index' 1178 */ 1179 end_index = index; 1180 index = start >> PAGE_CACHE_SHIFT; 1181 while (index < end_index) { 1182 page = find_get_page(tree->mapping, index); 1183 unlock_page(page); 1184 page_cache_release(page); 1185 index++; 1186 } 1187 return err; 1188 } 1189 EXPORT_SYMBOL(lock_range); 1190 1191 /* 1192 * helper function to unlock both pages and extents in the tree. 1193 */ 1194 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end) 1195 { 1196 unsigned long index = start >> PAGE_CACHE_SHIFT; 1197 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1198 struct page *page; 1199 1200 while (index <= end_index) { 1201 page = find_get_page(tree->mapping, index); 1202 unlock_page(page); 1203 page_cache_release(page); 1204 index++; 1205 } 1206 unlock_extent(tree, start, end, GFP_NOFS); 1207 return 0; 1208 } 1209 EXPORT_SYMBOL(unlock_range); 1210 1211 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private) 1212 { 1213 struct rb_node *node; 1214 struct extent_state *state; 1215 int ret = 0; 1216 1217 write_lock_irq(&tree->lock); 1218 /* 1219 * this search will find all the extents that end after 1220 * our range starts. 1221 */ 1222 node = tree_search(&tree->state, start); 1223 if (!node || IS_ERR(node)) { 1224 ret = -ENOENT; 1225 goto out; 1226 } 1227 state = rb_entry(node, struct extent_state, rb_node); 1228 if (state->start != start) { 1229 ret = -ENOENT; 1230 goto out; 1231 } 1232 state->private = private; 1233 out: 1234 write_unlock_irq(&tree->lock); 1235 return ret; 1236 } 1237 1238 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private) 1239 { 1240 struct rb_node *node; 1241 struct extent_state *state; 1242 int ret = 0; 1243 1244 read_lock_irq(&tree->lock); 1245 /* 1246 * this search will find all the extents that end after 1247 * our range starts. 1248 */ 1249 node = tree_search(&tree->state, start); 1250 if (!node || IS_ERR(node)) { 1251 ret = -ENOENT; 1252 goto out; 1253 } 1254 state = rb_entry(node, struct extent_state, rb_node); 1255 if (state->start != start) { 1256 ret = -ENOENT; 1257 goto out; 1258 } 1259 *private = state->private; 1260 out: 1261 read_unlock_irq(&tree->lock); 1262 return ret; 1263 } 1264 1265 /* 1266 * searches a range in the state tree for a given mask. 1267 * If 'filled' == 1, this returns 1 only if ever extent in the tree 1268 * has the bits set. Otherwise, 1 is returned if any bit in the 1269 * range is found set. 1270 */ 1271 int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end, 1272 int bits, int filled) 1273 { 1274 struct extent_state *state = NULL; 1275 struct rb_node *node; 1276 int bitset = 0; 1277 1278 read_lock_irq(&tree->lock); 1279 node = tree_search(&tree->state, start); 1280 while (node && start <= end) { 1281 state = rb_entry(node, struct extent_state, rb_node); 1282 1283 if (filled && state->start > start) { 1284 bitset = 0; 1285 break; 1286 } 1287 1288 if (state->start > end) 1289 break; 1290 1291 if (state->state & bits) { 1292 bitset = 1; 1293 if (!filled) 1294 break; 1295 } else if (filled) { 1296 bitset = 0; 1297 break; 1298 } 1299 start = state->end + 1; 1300 if (start > end) 1301 break; 1302 node = rb_next(node); 1303 } 1304 read_unlock_irq(&tree->lock); 1305 return bitset; 1306 } 1307 EXPORT_SYMBOL(test_range_bit); 1308 1309 /* 1310 * helper function to set a given page up to date if all the 1311 * extents in the tree for that page are up to date 1312 */ 1313 static int check_page_uptodate(struct extent_map_tree *tree, 1314 struct page *page) 1315 { 1316 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1317 u64 end = start + PAGE_CACHE_SIZE - 1; 1318 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1)) 1319 SetPageUptodate(page); 1320 return 0; 1321 } 1322 1323 /* 1324 * helper function to unlock a page if all the extents in the tree 1325 * for that page are unlocked 1326 */ 1327 static int check_page_locked(struct extent_map_tree *tree, 1328 struct page *page) 1329 { 1330 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1331 u64 end = start + PAGE_CACHE_SIZE - 1; 1332 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0)) 1333 unlock_page(page); 1334 return 0; 1335 } 1336 1337 /* 1338 * helper function to end page writeback if all the extents 1339 * in the tree for that page are done with writeback 1340 */ 1341 static int check_page_writeback(struct extent_map_tree *tree, 1342 struct page *page) 1343 { 1344 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1345 u64 end = start + PAGE_CACHE_SIZE - 1; 1346 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0)) 1347 end_page_writeback(page); 1348 return 0; 1349 } 1350 1351 /* lots and lots of room for performance fixes in the end_bio funcs */ 1352 1353 /* 1354 * after a writepage IO is done, we need to: 1355 * clear the uptodate bits on error 1356 * clear the writeback bits in the extent tree for this IO 1357 * end_page_writeback if the page has no more pending IO 1358 * 1359 * Scheduling is not allowed, so the extent state tree is expected 1360 * to have one and only one object corresponding to this IO. 1361 */ 1362 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1363 static void end_bio_extent_writepage(struct bio *bio, int err) 1364 #else 1365 static int end_bio_extent_writepage(struct bio *bio, 1366 unsigned int bytes_done, int err) 1367 #endif 1368 { 1369 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1370 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1371 struct extent_map_tree *tree = bio->bi_private; 1372 u64 start; 1373 u64 end; 1374 int whole_page; 1375 1376 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1377 if (bio->bi_size) 1378 return 1; 1379 #endif 1380 1381 do { 1382 struct page *page = bvec->bv_page; 1383 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1384 bvec->bv_offset; 1385 end = start + bvec->bv_len - 1; 1386 1387 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1388 whole_page = 1; 1389 else 1390 whole_page = 0; 1391 1392 if (--bvec >= bio->bi_io_vec) 1393 prefetchw(&bvec->bv_page->flags); 1394 1395 if (!uptodate) { 1396 clear_extent_uptodate(tree, start, end, GFP_ATOMIC); 1397 ClearPageUptodate(page); 1398 SetPageError(page); 1399 } 1400 clear_extent_writeback(tree, start, end, GFP_ATOMIC); 1401 1402 if (whole_page) 1403 end_page_writeback(page); 1404 else 1405 check_page_writeback(tree, page); 1406 if (tree->ops && tree->ops->writepage_end_io_hook) 1407 tree->ops->writepage_end_io_hook(page, start, end); 1408 } while (bvec >= bio->bi_io_vec); 1409 1410 bio_put(bio); 1411 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1412 return 0; 1413 #endif 1414 } 1415 1416 /* 1417 * after a readpage IO is done, we need to: 1418 * clear the uptodate bits on error 1419 * set the uptodate bits if things worked 1420 * set the page up to date if all extents in the tree are uptodate 1421 * clear the lock bit in the extent tree 1422 * unlock the page if there are no other extents locked for it 1423 * 1424 * Scheduling is not allowed, so the extent state tree is expected 1425 * to have one and only one object corresponding to this IO. 1426 */ 1427 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1428 static void end_bio_extent_readpage(struct bio *bio, int err) 1429 #else 1430 static int end_bio_extent_readpage(struct bio *bio, 1431 unsigned int bytes_done, int err) 1432 #endif 1433 { 1434 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1435 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1436 struct extent_map_tree *tree = bio->bi_private; 1437 u64 start; 1438 u64 end; 1439 int whole_page; 1440 int ret; 1441 1442 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1443 if (bio->bi_size) 1444 return 1; 1445 #endif 1446 1447 do { 1448 struct page *page = bvec->bv_page; 1449 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1450 bvec->bv_offset; 1451 end = start + bvec->bv_len - 1; 1452 1453 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1454 whole_page = 1; 1455 else 1456 whole_page = 0; 1457 1458 if (--bvec >= bio->bi_io_vec) 1459 prefetchw(&bvec->bv_page->flags); 1460 1461 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { 1462 ret = tree->ops->readpage_end_io_hook(page, start, end); 1463 if (ret) 1464 uptodate = 0; 1465 } 1466 if (uptodate) { 1467 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1468 if (whole_page) 1469 SetPageUptodate(page); 1470 else 1471 check_page_uptodate(tree, page); 1472 } else { 1473 ClearPageUptodate(page); 1474 SetPageError(page); 1475 } 1476 1477 unlock_extent(tree, start, end, GFP_ATOMIC); 1478 1479 if (whole_page) 1480 unlock_page(page); 1481 else 1482 check_page_locked(tree, page); 1483 } while (bvec >= bio->bi_io_vec); 1484 1485 bio_put(bio); 1486 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1487 return 0; 1488 #endif 1489 } 1490 1491 /* 1492 * IO done from prepare_write is pretty simple, we just unlock 1493 * the structs in the extent tree when done, and set the uptodate bits 1494 * as appropriate. 1495 */ 1496 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1497 static void end_bio_extent_preparewrite(struct bio *bio, int err) 1498 #else 1499 static int end_bio_extent_preparewrite(struct bio *bio, 1500 unsigned int bytes_done, int err) 1501 #endif 1502 { 1503 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1504 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1505 struct extent_map_tree *tree = bio->bi_private; 1506 u64 start; 1507 u64 end; 1508 1509 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1510 if (bio->bi_size) 1511 return 1; 1512 #endif 1513 1514 do { 1515 struct page *page = bvec->bv_page; 1516 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1517 bvec->bv_offset; 1518 end = start + bvec->bv_len - 1; 1519 1520 if (--bvec >= bio->bi_io_vec) 1521 prefetchw(&bvec->bv_page->flags); 1522 1523 if (uptodate) { 1524 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1525 } else { 1526 ClearPageUptodate(page); 1527 SetPageError(page); 1528 } 1529 1530 unlock_extent(tree, start, end, GFP_ATOMIC); 1531 1532 } while (bvec >= bio->bi_io_vec); 1533 1534 bio_put(bio); 1535 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1536 return 0; 1537 #endif 1538 } 1539 1540 static struct bio * 1541 extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, 1542 gfp_t gfp_flags) 1543 { 1544 struct bio *bio; 1545 1546 bio = bio_alloc(gfp_flags, nr_vecs); 1547 1548 if (bio == NULL && (current->flags & PF_MEMALLOC)) { 1549 while (!bio && (nr_vecs /= 2)) 1550 bio = bio_alloc(gfp_flags, nr_vecs); 1551 } 1552 1553 if (bio) { 1554 bio->bi_bdev = bdev; 1555 bio->bi_sector = first_sector; 1556 } 1557 return bio; 1558 } 1559 1560 static int submit_one_bio(int rw, struct bio *bio) 1561 { 1562 int ret = 0; 1563 bio_get(bio); 1564 submit_bio(rw, bio); 1565 if (bio_flagged(bio, BIO_EOPNOTSUPP)) 1566 ret = -EOPNOTSUPP; 1567 bio_put(bio); 1568 return ret; 1569 } 1570 1571 static int submit_extent_page(int rw, struct extent_map_tree *tree, 1572 struct page *page, sector_t sector, 1573 size_t size, unsigned long offset, 1574 struct block_device *bdev, 1575 struct bio **bio_ret, 1576 unsigned long max_pages, 1577 bio_end_io_t end_io_func) 1578 { 1579 int ret = 0; 1580 struct bio *bio; 1581 int nr; 1582 1583 if (bio_ret && *bio_ret) { 1584 bio = *bio_ret; 1585 if (bio->bi_sector + (bio->bi_size >> 9) != sector || 1586 bio_add_page(bio, page, size, offset) < size) { 1587 ret = submit_one_bio(rw, bio); 1588 bio = NULL; 1589 } else { 1590 return 0; 1591 } 1592 } 1593 nr = min_t(int, max_pages, bio_get_nr_vecs(bdev)); 1594 bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH); 1595 if (!bio) { 1596 printk("failed to allocate bio nr %d\n", nr); 1597 } 1598 bio_add_page(bio, page, size, offset); 1599 bio->bi_end_io = end_io_func; 1600 bio->bi_private = tree; 1601 if (bio_ret) { 1602 *bio_ret = bio; 1603 } else { 1604 ret = submit_one_bio(rw, bio); 1605 } 1606 1607 return ret; 1608 } 1609 1610 void set_page_extent_mapped(struct page *page) 1611 { 1612 if (!PagePrivate(page)) { 1613 SetPagePrivate(page); 1614 WARN_ON(!page->mapping->a_ops->invalidatepage); 1615 set_page_private(page, EXTENT_PAGE_PRIVATE); 1616 page_cache_get(page); 1617 } 1618 } 1619 1620 /* 1621 * basic readpage implementation. Locked extent state structs are inserted 1622 * into the tree that are removed when the IO is done (by the end_io 1623 * handlers) 1624 */ 1625 static int __extent_read_full_page(struct extent_map_tree *tree, 1626 struct page *page, 1627 get_extent_t *get_extent, 1628 struct bio **bio) 1629 { 1630 struct inode *inode = page->mapping->host; 1631 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1632 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1633 u64 end; 1634 u64 cur = start; 1635 u64 extent_offset; 1636 u64 last_byte = i_size_read(inode); 1637 u64 block_start; 1638 u64 cur_end; 1639 sector_t sector; 1640 struct extent_map *em; 1641 struct block_device *bdev; 1642 int ret; 1643 int nr = 0; 1644 size_t page_offset = 0; 1645 size_t iosize; 1646 size_t blocksize = inode->i_sb->s_blocksize; 1647 1648 set_page_extent_mapped(page); 1649 1650 end = page_end; 1651 lock_extent(tree, start, end, GFP_NOFS); 1652 1653 while (cur <= end) { 1654 if (cur >= last_byte) { 1655 iosize = PAGE_CACHE_SIZE - page_offset; 1656 zero_user_page(page, page_offset, iosize, KM_USER0); 1657 set_extent_uptodate(tree, cur, cur + iosize - 1, 1658 GFP_NOFS); 1659 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1660 break; 1661 } 1662 em = get_extent(inode, page, page_offset, cur, end, 0); 1663 if (IS_ERR(em) || !em) { 1664 SetPageError(page); 1665 unlock_extent(tree, cur, end, GFP_NOFS); 1666 break; 1667 } 1668 1669 extent_offset = cur - em->start; 1670 BUG_ON(em->end < cur); 1671 BUG_ON(end < cur); 1672 1673 iosize = min(em->end - cur, end - cur) + 1; 1674 cur_end = min(em->end, end); 1675 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1676 sector = (em->block_start + extent_offset) >> 9; 1677 bdev = em->bdev; 1678 block_start = em->block_start; 1679 free_extent_map(em); 1680 em = NULL; 1681 1682 /* we've found a hole, just zero and go on */ 1683 if (block_start == EXTENT_MAP_HOLE) { 1684 zero_user_page(page, page_offset, iosize, KM_USER0); 1685 set_extent_uptodate(tree, cur, cur + iosize - 1, 1686 GFP_NOFS); 1687 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1688 cur = cur + iosize; 1689 page_offset += iosize; 1690 continue; 1691 } 1692 /* the get_extent function already copied into the page */ 1693 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { 1694 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1695 cur = cur + iosize; 1696 page_offset += iosize; 1697 continue; 1698 } 1699 1700 ret = 0; 1701 if (tree->ops && tree->ops->readpage_io_hook) { 1702 ret = tree->ops->readpage_io_hook(page, cur, 1703 cur + iosize - 1); 1704 } 1705 if (!ret) { 1706 unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1; 1707 nr -= page->index; 1708 ret = submit_extent_page(READ, tree, page, 1709 sector, iosize, page_offset, 1710 bdev, bio, nr, 1711 end_bio_extent_readpage); 1712 } 1713 if (ret) 1714 SetPageError(page); 1715 cur = cur + iosize; 1716 page_offset += iosize; 1717 nr++; 1718 } 1719 if (!nr) { 1720 if (!PageError(page)) 1721 SetPageUptodate(page); 1722 unlock_page(page); 1723 } 1724 return 0; 1725 } 1726 1727 int extent_read_full_page(struct extent_map_tree *tree, struct page *page, 1728 get_extent_t *get_extent) 1729 { 1730 struct bio *bio = NULL; 1731 int ret; 1732 1733 ret = __extent_read_full_page(tree, page, get_extent, &bio); 1734 if (bio) 1735 submit_one_bio(READ, bio); 1736 return ret; 1737 } 1738 EXPORT_SYMBOL(extent_read_full_page); 1739 1740 /* 1741 * the writepage semantics are similar to regular writepage. extent 1742 * records are inserted to lock ranges in the tree, and as dirty areas 1743 * are found, they are marked writeback. Then the lock bits are removed 1744 * and the end_io handler clears the writeback ranges 1745 */ 1746 static int __extent_writepage(struct page *page, struct writeback_control *wbc, 1747 void *data) 1748 { 1749 struct inode *inode = page->mapping->host; 1750 struct extent_page_data *epd = data; 1751 struct extent_map_tree *tree = epd->tree; 1752 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1753 u64 delalloc_start; 1754 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1755 u64 end; 1756 u64 cur = start; 1757 u64 extent_offset; 1758 u64 last_byte = i_size_read(inode); 1759 u64 block_start; 1760 u64 iosize; 1761 sector_t sector; 1762 struct extent_map *em; 1763 struct block_device *bdev; 1764 int ret; 1765 int nr = 0; 1766 size_t page_offset = 0; 1767 size_t blocksize; 1768 loff_t i_size = i_size_read(inode); 1769 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; 1770 u64 nr_delalloc; 1771 u64 delalloc_end; 1772 1773 WARN_ON(!PageLocked(page)); 1774 if (page->index > end_index) { 1775 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1776 unlock_page(page); 1777 return 0; 1778 } 1779 1780 if (page->index == end_index) { 1781 size_t offset = i_size & (PAGE_CACHE_SIZE - 1); 1782 zero_user_page(page, offset, 1783 PAGE_CACHE_SIZE - offset, KM_USER0); 1784 } 1785 1786 set_page_extent_mapped(page); 1787 1788 delalloc_start = start; 1789 delalloc_end = 0; 1790 while(delalloc_end < page_end) { 1791 nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start, 1792 &delalloc_end, 1793 128 * 1024 * 1024); 1794 if (nr_delalloc <= 0) 1795 break; 1796 tree->ops->fill_delalloc(inode, delalloc_start, 1797 delalloc_end); 1798 clear_extent_bit(tree, delalloc_start, 1799 delalloc_end, 1800 EXTENT_LOCKED | EXTENT_DELALLOC, 1801 1, 0, GFP_NOFS); 1802 delalloc_start = delalloc_end + 1; 1803 } 1804 lock_extent(tree, start, page_end, GFP_NOFS); 1805 1806 end = page_end; 1807 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1808 printk("found delalloc bits after lock_extent\n"); 1809 } 1810 1811 if (last_byte <= start) { 1812 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1813 goto done; 1814 } 1815 1816 set_extent_uptodate(tree, start, page_end, GFP_NOFS); 1817 blocksize = inode->i_sb->s_blocksize; 1818 1819 while (cur <= end) { 1820 if (cur >= last_byte) { 1821 clear_extent_dirty(tree, cur, page_end, GFP_NOFS); 1822 break; 1823 } 1824 em = epd->get_extent(inode, page, page_offset, cur, end, 1); 1825 if (IS_ERR(em) || !em) { 1826 SetPageError(page); 1827 break; 1828 } 1829 1830 extent_offset = cur - em->start; 1831 BUG_ON(em->end < cur); 1832 BUG_ON(end < cur); 1833 iosize = min(em->end - cur, end - cur) + 1; 1834 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1835 sector = (em->block_start + extent_offset) >> 9; 1836 bdev = em->bdev; 1837 block_start = em->block_start; 1838 free_extent_map(em); 1839 em = NULL; 1840 1841 if (block_start == EXTENT_MAP_HOLE || 1842 block_start == EXTENT_MAP_INLINE) { 1843 clear_extent_dirty(tree, cur, 1844 cur + iosize - 1, GFP_NOFS); 1845 cur = cur + iosize; 1846 page_offset += iosize; 1847 continue; 1848 } 1849 1850 /* leave this out until we have a page_mkwrite call */ 1851 if (0 && !test_range_bit(tree, cur, cur + iosize - 1, 1852 EXTENT_DIRTY, 0)) { 1853 cur = cur + iosize; 1854 page_offset += iosize; 1855 continue; 1856 } 1857 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); 1858 if (tree->ops && tree->ops->writepage_io_hook) { 1859 ret = tree->ops->writepage_io_hook(page, cur, 1860 cur + iosize - 1); 1861 } else { 1862 ret = 0; 1863 } 1864 if (ret) 1865 SetPageError(page); 1866 else { 1867 unsigned long max_nr = end_index + 1; 1868 set_range_writeback(tree, cur, cur + iosize - 1); 1869 if (!PageWriteback(page)) { 1870 printk("warning page %lu not writeback, " 1871 "cur %llu end %llu\n", page->index, 1872 (unsigned long long)cur, 1873 (unsigned long long)end); 1874 } 1875 1876 ret = submit_extent_page(WRITE, tree, page, sector, 1877 iosize, page_offset, bdev, 1878 &epd->bio, max_nr, 1879 end_bio_extent_writepage); 1880 if (ret) 1881 SetPageError(page); 1882 } 1883 cur = cur + iosize; 1884 page_offset += iosize; 1885 nr++; 1886 } 1887 done: 1888 if (nr == 0) { 1889 /* make sure the mapping tag for page dirty gets cleared */ 1890 set_page_writeback(page); 1891 end_page_writeback(page); 1892 } 1893 unlock_extent(tree, start, page_end, GFP_NOFS); 1894 unlock_page(page); 1895 return 0; 1896 } 1897 1898 int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 1899 get_extent_t *get_extent, 1900 struct writeback_control *wbc) 1901 { 1902 int ret; 1903 struct address_space *mapping = page->mapping; 1904 struct extent_page_data epd = { 1905 .bio = NULL, 1906 .tree = tree, 1907 .get_extent = get_extent, 1908 }; 1909 struct writeback_control wbc_writepages = { 1910 .bdi = wbc->bdi, 1911 .sync_mode = WB_SYNC_NONE, 1912 .older_than_this = NULL, 1913 .nr_to_write = 64, 1914 .range_start = page_offset(page) + PAGE_CACHE_SIZE, 1915 .range_end = (loff_t)-1, 1916 }; 1917 1918 1919 ret = __extent_writepage(page, wbc, &epd); 1920 1921 write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd); 1922 if (epd.bio) 1923 submit_one_bio(WRITE, epd.bio); 1924 return ret; 1925 } 1926 EXPORT_SYMBOL(extent_write_full_page); 1927 1928 int extent_writepages(struct extent_map_tree *tree, 1929 struct address_space *mapping, 1930 get_extent_t *get_extent, 1931 struct writeback_control *wbc) 1932 { 1933 int ret; 1934 struct extent_page_data epd = { 1935 .bio = NULL, 1936 .tree = tree, 1937 .get_extent = get_extent, 1938 }; 1939 1940 ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd); 1941 if (epd.bio) 1942 submit_one_bio(WRITE, epd.bio); 1943 return ret; 1944 } 1945 EXPORT_SYMBOL(extent_writepages); 1946 1947 int extent_readpages(struct extent_map_tree *tree, 1948 struct address_space *mapping, 1949 struct list_head *pages, unsigned nr_pages, 1950 get_extent_t get_extent) 1951 { 1952 struct bio *bio = NULL; 1953 unsigned page_idx; 1954 struct pagevec pvec; 1955 1956 pagevec_init(&pvec, 0); 1957 for (page_idx = 0; page_idx < nr_pages; page_idx++) { 1958 struct page *page = list_entry(pages->prev, struct page, lru); 1959 1960 prefetchw(&page->flags); 1961 list_del(&page->lru); 1962 /* 1963 * what we want to do here is call add_to_page_cache_lru, 1964 * but that isn't exported, so we reproduce it here 1965 */ 1966 if (!add_to_page_cache(page, mapping, 1967 page->index, GFP_KERNEL)) { 1968 1969 /* open coding of lru_cache_add, also not exported */ 1970 page_cache_get(page); 1971 if (!pagevec_add(&pvec, page)) 1972 __pagevec_lru_add(&pvec); 1973 __extent_read_full_page(tree, page, get_extent, &bio); 1974 } 1975 page_cache_release(page); 1976 } 1977 if (pagevec_count(&pvec)) 1978 __pagevec_lru_add(&pvec); 1979 BUG_ON(!list_empty(pages)); 1980 if (bio) 1981 submit_one_bio(READ, bio); 1982 return 0; 1983 } 1984 EXPORT_SYMBOL(extent_readpages); 1985 1986 /* 1987 * basic invalidatepage code, this waits on any locked or writeback 1988 * ranges corresponding to the page, and then deletes any extent state 1989 * records from the tree 1990 */ 1991 int extent_invalidatepage(struct extent_map_tree *tree, 1992 struct page *page, unsigned long offset) 1993 { 1994 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT); 1995 u64 end = start + PAGE_CACHE_SIZE - 1; 1996 size_t blocksize = page->mapping->host->i_sb->s_blocksize; 1997 1998 start += (offset + blocksize -1) & ~(blocksize - 1); 1999 if (start > end) 2000 return 0; 2001 2002 lock_extent(tree, start, end, GFP_NOFS); 2003 wait_on_extent_writeback(tree, start, end); 2004 clear_extent_bit(tree, start, end, 2005 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, 2006 1, 1, GFP_NOFS); 2007 return 0; 2008 } 2009 EXPORT_SYMBOL(extent_invalidatepage); 2010 2011 /* 2012 * simple commit_write call, set_range_dirty is used to mark both 2013 * the pages and the extent records as dirty 2014 */ 2015 int extent_commit_write(struct extent_map_tree *tree, 2016 struct inode *inode, struct page *page, 2017 unsigned from, unsigned to) 2018 { 2019 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; 2020 2021 set_page_extent_mapped(page); 2022 set_page_dirty(page); 2023 2024 if (pos > inode->i_size) { 2025 i_size_write(inode, pos); 2026 mark_inode_dirty(inode); 2027 } 2028 return 0; 2029 } 2030 EXPORT_SYMBOL(extent_commit_write); 2031 2032 int extent_prepare_write(struct extent_map_tree *tree, 2033 struct inode *inode, struct page *page, 2034 unsigned from, unsigned to, get_extent_t *get_extent) 2035 { 2036 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 2037 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 2038 u64 block_start; 2039 u64 orig_block_start; 2040 u64 block_end; 2041 u64 cur_end; 2042 struct extent_map *em; 2043 unsigned blocksize = 1 << inode->i_blkbits; 2044 size_t page_offset = 0; 2045 size_t block_off_start; 2046 size_t block_off_end; 2047 int err = 0; 2048 int iocount = 0; 2049 int ret = 0; 2050 int isnew; 2051 2052 set_page_extent_mapped(page); 2053 2054 block_start = (page_start + from) & ~((u64)blocksize - 1); 2055 block_end = (page_start + to - 1) | (blocksize - 1); 2056 orig_block_start = block_start; 2057 2058 lock_extent(tree, page_start, page_end, GFP_NOFS); 2059 while(block_start <= block_end) { 2060 em = get_extent(inode, page, page_offset, block_start, 2061 block_end, 1); 2062 if (IS_ERR(em) || !em) { 2063 goto err; 2064 } 2065 cur_end = min(block_end, em->end); 2066 block_off_start = block_start & (PAGE_CACHE_SIZE - 1); 2067 block_off_end = block_off_start + blocksize; 2068 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); 2069 2070 if (!PageUptodate(page) && isnew && 2071 (block_off_end > to || block_off_start < from)) { 2072 void *kaddr; 2073 2074 kaddr = kmap_atomic(page, KM_USER0); 2075 if (block_off_end > to) 2076 memset(kaddr + to, 0, block_off_end - to); 2077 if (block_off_start < from) 2078 memset(kaddr + block_off_start, 0, 2079 from - block_off_start); 2080 flush_dcache_page(page); 2081 kunmap_atomic(kaddr, KM_USER0); 2082 } 2083 if (!isnew && !PageUptodate(page) && 2084 (block_off_end > to || block_off_start < from) && 2085 !test_range_bit(tree, block_start, cur_end, 2086 EXTENT_UPTODATE, 1)) { 2087 u64 sector; 2088 u64 extent_offset = block_start - em->start; 2089 size_t iosize; 2090 sector = (em->block_start + extent_offset) >> 9; 2091 iosize = (cur_end - block_start + blocksize - 1) & 2092 ~((u64)blocksize - 1); 2093 /* 2094 * we've already got the extent locked, but we 2095 * need to split the state such that our end_bio 2096 * handler can clear the lock. 2097 */ 2098 set_extent_bit(tree, block_start, 2099 block_start + iosize - 1, 2100 EXTENT_LOCKED, 0, NULL, GFP_NOFS); 2101 ret = submit_extent_page(READ, tree, page, 2102 sector, iosize, page_offset, em->bdev, 2103 NULL, 1, 2104 end_bio_extent_preparewrite); 2105 iocount++; 2106 block_start = block_start + iosize; 2107 } else { 2108 set_extent_uptodate(tree, block_start, cur_end, 2109 GFP_NOFS); 2110 unlock_extent(tree, block_start, cur_end, GFP_NOFS); 2111 block_start = cur_end + 1; 2112 } 2113 page_offset = block_start & (PAGE_CACHE_SIZE - 1); 2114 free_extent_map(em); 2115 } 2116 if (iocount) { 2117 wait_extent_bit(tree, orig_block_start, 2118 block_end, EXTENT_LOCKED); 2119 } 2120 check_page_uptodate(tree, page); 2121 err: 2122 /* FIXME, zero out newly allocated blocks on error */ 2123 return err; 2124 } 2125 EXPORT_SYMBOL(extent_prepare_write); 2126 2127 /* 2128 * a helper for releasepage. As long as there are no locked extents 2129 * in the range corresponding to the page, both state records and extent 2130 * map records are removed 2131 */ 2132 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) 2133 { 2134 struct extent_map *em; 2135 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 2136 u64 end = start + PAGE_CACHE_SIZE - 1; 2137 u64 orig_start = start; 2138 int ret = 1; 2139 2140 while (start <= end) { 2141 em = lookup_extent_mapping(tree, start, end); 2142 if (!em || IS_ERR(em)) 2143 break; 2144 if (!test_range_bit(tree, em->start, em->end, 2145 EXTENT_LOCKED, 0)) { 2146 remove_extent_mapping(tree, em); 2147 /* once for the rb tree */ 2148 free_extent_map(em); 2149 } 2150 start = em->end + 1; 2151 /* once for us */ 2152 free_extent_map(em); 2153 } 2154 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) 2155 ret = 0; 2156 else 2157 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, 2158 1, 1, GFP_NOFS); 2159 return ret; 2160 } 2161 EXPORT_SYMBOL(try_release_extent_mapping); 2162 2163 sector_t extent_bmap(struct address_space *mapping, sector_t iblock, 2164 get_extent_t *get_extent) 2165 { 2166 struct inode *inode = mapping->host; 2167 u64 start = iblock << inode->i_blkbits; 2168 u64 end = start + (1 << inode->i_blkbits) - 1; 2169 sector_t sector = 0; 2170 struct extent_map *em; 2171 2172 em = get_extent(inode, NULL, 0, start, end, 0); 2173 if (!em || IS_ERR(em)) 2174 return 0; 2175 2176 if (em->block_start == EXTENT_MAP_INLINE || 2177 em->block_start == EXTENT_MAP_HOLE) 2178 goto out; 2179 2180 sector = (em->block_start + start - em->start) >> inode->i_blkbits; 2181 out: 2182 free_extent_map(em); 2183 return sector; 2184 } 2185 2186 static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb) 2187 { 2188 if (list_empty(&eb->lru)) { 2189 extent_buffer_get(eb); 2190 list_add(&eb->lru, &tree->buffer_lru); 2191 tree->lru_size++; 2192 if (tree->lru_size >= BUFFER_LRU_MAX) { 2193 struct extent_buffer *rm; 2194 rm = list_entry(tree->buffer_lru.prev, 2195 struct extent_buffer, lru); 2196 tree->lru_size--; 2197 list_del_init(&rm->lru); 2198 free_extent_buffer(rm); 2199 } 2200 } else 2201 list_move(&eb->lru, &tree->buffer_lru); 2202 return 0; 2203 } 2204 static struct extent_buffer *find_lru(struct extent_map_tree *tree, 2205 u64 start, unsigned long len) 2206 { 2207 struct list_head *lru = &tree->buffer_lru; 2208 struct list_head *cur = lru->next; 2209 struct extent_buffer *eb; 2210 2211 if (list_empty(lru)) 2212 return NULL; 2213 2214 do { 2215 eb = list_entry(cur, struct extent_buffer, lru); 2216 if (eb->start == start && eb->len == len) { 2217 extent_buffer_get(eb); 2218 return eb; 2219 } 2220 cur = cur->next; 2221 } while (cur != lru); 2222 return NULL; 2223 } 2224 2225 static inline unsigned long num_extent_pages(u64 start, u64 len) 2226 { 2227 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - 2228 (start >> PAGE_CACHE_SHIFT); 2229 } 2230 2231 static inline struct page *extent_buffer_page(struct extent_buffer *eb, 2232 unsigned long i) 2233 { 2234 struct page *p; 2235 struct address_space *mapping; 2236 2237 if (i == 0) 2238 return eb->first_page; 2239 i += eb->start >> PAGE_CACHE_SHIFT; 2240 mapping = eb->first_page->mapping; 2241 read_lock_irq(&mapping->tree_lock); 2242 p = radix_tree_lookup(&mapping->page_tree, i); 2243 read_unlock_irq(&mapping->tree_lock); 2244 return p; 2245 } 2246 2247 static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, 2248 u64 start, 2249 unsigned long len, 2250 gfp_t mask) 2251 { 2252 struct extent_buffer *eb = NULL; 2253 2254 spin_lock(&tree->lru_lock); 2255 eb = find_lru(tree, start, len); 2256 spin_unlock(&tree->lru_lock); 2257 if (eb) { 2258 return eb; 2259 } 2260 2261 eb = kmem_cache_zalloc(extent_buffer_cache, mask); 2262 INIT_LIST_HEAD(&eb->lru); 2263 eb->start = start; 2264 eb->len = len; 2265 atomic_set(&eb->refs, 1); 2266 2267 return eb; 2268 } 2269 2270 static void __free_extent_buffer(struct extent_buffer *eb) 2271 { 2272 kmem_cache_free(extent_buffer_cache, eb); 2273 } 2274 2275 struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 2276 u64 start, unsigned long len, 2277 struct page *page0, 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 if (page0) { 2296 eb->first_page = page0; 2297 i = 1; 2298 index++; 2299 page_cache_get(page0); 2300 mark_page_accessed(page0); 2301 set_page_extent_mapped(page0); 2302 WARN_ON(!PageUptodate(page0)); 2303 set_page_private(page0, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2304 len << 2); 2305 } else { 2306 i = 0; 2307 } 2308 for (; i < num_pages; i++, index++) { 2309 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM); 2310 if (!p) { 2311 WARN_ON(1); 2312 goto fail; 2313 } 2314 set_page_extent_mapped(p); 2315 mark_page_accessed(p); 2316 if (i == 0) { 2317 eb->first_page = p; 2318 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2319 len << 2); 2320 } else { 2321 set_page_private(p, EXTENT_PAGE_PRIVATE); 2322 } 2323 if (!PageUptodate(p)) 2324 uptodate = 0; 2325 unlock_page(p); 2326 } 2327 if (uptodate) 2328 eb->flags |= EXTENT_UPTODATE; 2329 eb->flags |= EXTENT_BUFFER_FILLED; 2330 2331 lru_add: 2332 spin_lock(&tree->lru_lock); 2333 add_lru(tree, eb); 2334 spin_unlock(&tree->lru_lock); 2335 return eb; 2336 2337 fail: 2338 spin_lock(&tree->lru_lock); 2339 list_del_init(&eb->lru); 2340 spin_unlock(&tree->lru_lock); 2341 if (!atomic_dec_and_test(&eb->refs)) 2342 return NULL; 2343 for (index = 1; index < i; index++) { 2344 page_cache_release(extent_buffer_page(eb, index)); 2345 } 2346 if (i > 0) 2347 page_cache_release(extent_buffer_page(eb, 0)); 2348 __free_extent_buffer(eb); 2349 return NULL; 2350 } 2351 EXPORT_SYMBOL(alloc_extent_buffer); 2352 2353 struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 2354 u64 start, unsigned long len, 2355 gfp_t mask) 2356 { 2357 unsigned long num_pages = num_extent_pages(start, len); 2358 unsigned long i; 2359 unsigned long index = start >> PAGE_CACHE_SHIFT; 2360 struct extent_buffer *eb; 2361 struct page *p; 2362 struct address_space *mapping = tree->mapping; 2363 int uptodate = 1; 2364 2365 eb = __alloc_extent_buffer(tree, start, len, mask); 2366 if (!eb || IS_ERR(eb)) 2367 return NULL; 2368 2369 if (eb->flags & EXTENT_BUFFER_FILLED) 2370 goto lru_add; 2371 2372 for (i = 0; i < num_pages; i++, index++) { 2373 p = find_lock_page(mapping, index); 2374 if (!p) { 2375 goto fail; 2376 } 2377 set_page_extent_mapped(p); 2378 mark_page_accessed(p); 2379 2380 if (i == 0) { 2381 eb->first_page = p; 2382 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2383 len << 2); 2384 } else { 2385 set_page_private(p, EXTENT_PAGE_PRIVATE); 2386 } 2387 2388 if (!PageUptodate(p)) 2389 uptodate = 0; 2390 unlock_page(p); 2391 } 2392 if (uptodate) 2393 eb->flags |= EXTENT_UPTODATE; 2394 eb->flags |= EXTENT_BUFFER_FILLED; 2395 2396 lru_add: 2397 spin_lock(&tree->lru_lock); 2398 add_lru(tree, eb); 2399 spin_unlock(&tree->lru_lock); 2400 return eb; 2401 fail: 2402 spin_lock(&tree->lru_lock); 2403 list_del_init(&eb->lru); 2404 spin_unlock(&tree->lru_lock); 2405 if (!atomic_dec_and_test(&eb->refs)) 2406 return NULL; 2407 for (index = 1; index < i; index++) { 2408 page_cache_release(extent_buffer_page(eb, index)); 2409 } 2410 if (i > 0) 2411 page_cache_release(extent_buffer_page(eb, 0)); 2412 __free_extent_buffer(eb); 2413 return NULL; 2414 } 2415 EXPORT_SYMBOL(find_extent_buffer); 2416 2417 void free_extent_buffer(struct extent_buffer *eb) 2418 { 2419 unsigned long i; 2420 unsigned long num_pages; 2421 2422 if (!eb) 2423 return; 2424 2425 if (!atomic_dec_and_test(&eb->refs)) 2426 return; 2427 2428 WARN_ON(!list_empty(&eb->lru)); 2429 num_pages = num_extent_pages(eb->start, eb->len); 2430 2431 for (i = 1; i < num_pages; i++) { 2432 page_cache_release(extent_buffer_page(eb, i)); 2433 } 2434 page_cache_release(extent_buffer_page(eb, 0)); 2435 __free_extent_buffer(eb); 2436 } 2437 EXPORT_SYMBOL(free_extent_buffer); 2438 2439 int clear_extent_buffer_dirty(struct extent_map_tree *tree, 2440 struct extent_buffer *eb) 2441 { 2442 int set; 2443 unsigned long i; 2444 unsigned long num_pages; 2445 struct page *page; 2446 2447 u64 start = eb->start; 2448 u64 end = start + eb->len - 1; 2449 2450 set = clear_extent_dirty(tree, start, end, GFP_NOFS); 2451 num_pages = num_extent_pages(eb->start, eb->len); 2452 2453 for (i = 0; i < num_pages; i++) { 2454 page = extent_buffer_page(eb, i); 2455 lock_page(page); 2456 /* 2457 * if we're on the last page or the first page and the 2458 * block isn't aligned on a page boundary, do extra checks 2459 * to make sure we don't clean page that is partially dirty 2460 */ 2461 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2462 ((i == num_pages - 1) && 2463 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2464 start = (u64)page->index << PAGE_CACHE_SHIFT; 2465 end = start + PAGE_CACHE_SIZE - 1; 2466 if (test_range_bit(tree, start, end, 2467 EXTENT_DIRTY, 0)) { 2468 unlock_page(page); 2469 continue; 2470 } 2471 } 2472 clear_page_dirty_for_io(page); 2473 write_lock_irq(&page->mapping->tree_lock); 2474 if (!PageDirty(page)) { 2475 radix_tree_tag_clear(&page->mapping->page_tree, 2476 page_index(page), 2477 PAGECACHE_TAG_DIRTY); 2478 } 2479 write_unlock_irq(&page->mapping->tree_lock); 2480 unlock_page(page); 2481 } 2482 return 0; 2483 } 2484 EXPORT_SYMBOL(clear_extent_buffer_dirty); 2485 2486 int wait_on_extent_buffer_writeback(struct extent_map_tree *tree, 2487 struct extent_buffer *eb) 2488 { 2489 return wait_on_extent_writeback(tree, eb->start, 2490 eb->start + eb->len - 1); 2491 } 2492 EXPORT_SYMBOL(wait_on_extent_buffer_writeback); 2493 2494 int set_extent_buffer_dirty(struct extent_map_tree *tree, 2495 struct extent_buffer *eb) 2496 { 2497 unsigned long i; 2498 unsigned long num_pages; 2499 2500 num_pages = num_extent_pages(eb->start, eb->len); 2501 for (i = 0; i < num_pages; i++) { 2502 struct page *page = extent_buffer_page(eb, i); 2503 /* writepage may need to do something special for the 2504 * first page, we have to make sure page->private is 2505 * properly set. releasepage may drop page->private 2506 * on us if the page isn't already dirty. 2507 */ 2508 if (i == 0) { 2509 lock_page(page); 2510 set_page_private(page, 2511 EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2512 eb->len << 2); 2513 } 2514 __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); 2515 if (i == 0) 2516 unlock_page(page); 2517 } 2518 return set_extent_dirty(tree, eb->start, 2519 eb->start + eb->len - 1, GFP_NOFS); 2520 } 2521 EXPORT_SYMBOL(set_extent_buffer_dirty); 2522 2523 int set_extent_buffer_uptodate(struct extent_map_tree *tree, 2524 struct extent_buffer *eb) 2525 { 2526 unsigned long i; 2527 struct page *page; 2528 unsigned long num_pages; 2529 2530 num_pages = num_extent_pages(eb->start, eb->len); 2531 2532 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, 2533 GFP_NOFS); 2534 for (i = 0; i < num_pages; i++) { 2535 page = extent_buffer_page(eb, i); 2536 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2537 ((i == num_pages - 1) && 2538 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2539 check_page_uptodate(tree, page); 2540 continue; 2541 } 2542 SetPageUptodate(page); 2543 } 2544 return 0; 2545 } 2546 EXPORT_SYMBOL(set_extent_buffer_uptodate); 2547 2548 int extent_buffer_uptodate(struct extent_map_tree *tree, 2549 struct extent_buffer *eb) 2550 { 2551 if (eb->flags & EXTENT_UPTODATE) 2552 return 1; 2553 return test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2554 EXTENT_UPTODATE, 1); 2555 } 2556 EXPORT_SYMBOL(extent_buffer_uptodate); 2557 2558 int read_extent_buffer_pages(struct extent_map_tree *tree, 2559 struct extent_buffer *eb, 2560 u64 start, 2561 int wait) 2562 { 2563 unsigned long i; 2564 unsigned long start_i; 2565 struct page *page; 2566 int err; 2567 int ret = 0; 2568 unsigned long num_pages; 2569 2570 if (eb->flags & EXTENT_UPTODATE) 2571 return 0; 2572 2573 if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2574 EXTENT_UPTODATE, 1)) { 2575 return 0; 2576 } 2577 2578 if (start) { 2579 WARN_ON(start < eb->start); 2580 start_i = (start >> PAGE_CACHE_SHIFT) - 2581 (eb->start >> PAGE_CACHE_SHIFT); 2582 } else { 2583 start_i = 0; 2584 } 2585 2586 num_pages = num_extent_pages(eb->start, eb->len); 2587 for (i = start_i; i < num_pages; i++) { 2588 page = extent_buffer_page(eb, i); 2589 if (PageUptodate(page)) { 2590 continue; 2591 } 2592 if (!wait) { 2593 if (TestSetPageLocked(page)) { 2594 continue; 2595 } 2596 } else { 2597 lock_page(page); 2598 } 2599 if (!PageUptodate(page)) { 2600 err = page->mapping->a_ops->readpage(NULL, page); 2601 if (err) { 2602 ret = err; 2603 } 2604 } else { 2605 unlock_page(page); 2606 } 2607 } 2608 2609 if (ret || !wait) { 2610 return ret; 2611 } 2612 2613 for (i = start_i; i < num_pages; i++) { 2614 page = extent_buffer_page(eb, i); 2615 wait_on_page_locked(page); 2616 if (!PageUptodate(page)) { 2617 ret = -EIO; 2618 } 2619 } 2620 if (!ret) 2621 eb->flags |= EXTENT_UPTODATE; 2622 return ret; 2623 } 2624 EXPORT_SYMBOL(read_extent_buffer_pages); 2625 2626 void read_extent_buffer(struct extent_buffer *eb, void *dstv, 2627 unsigned long start, 2628 unsigned long len) 2629 { 2630 size_t cur; 2631 size_t offset; 2632 struct page *page; 2633 char *kaddr; 2634 char *dst = (char *)dstv; 2635 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2636 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2637 unsigned long num_pages = num_extent_pages(eb->start, eb->len); 2638 2639 WARN_ON(start > eb->len); 2640 WARN_ON(start + len > eb->start + eb->len); 2641 2642 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2643 2644 while(len > 0) { 2645 page = extent_buffer_page(eb, i); 2646 if (!PageUptodate(page)) { 2647 printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); 2648 WARN_ON(1); 2649 } 2650 WARN_ON(!PageUptodate(page)); 2651 2652 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2653 kaddr = kmap_atomic(page, KM_USER1); 2654 memcpy(dst, kaddr + offset, cur); 2655 kunmap_atomic(kaddr, KM_USER1); 2656 2657 dst += cur; 2658 len -= cur; 2659 offset = 0; 2660 i++; 2661 } 2662 } 2663 EXPORT_SYMBOL(read_extent_buffer); 2664 2665 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, 2666 unsigned long min_len, char **token, char **map, 2667 unsigned long *map_start, 2668 unsigned long *map_len, int km) 2669 { 2670 size_t offset = start & (PAGE_CACHE_SIZE - 1); 2671 char *kaddr; 2672 struct page *p; 2673 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2674 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2675 unsigned long end_i = (start_offset + start + min_len - 1) >> 2676 PAGE_CACHE_SHIFT; 2677 2678 if (i != end_i) 2679 return -EINVAL; 2680 2681 if (i == 0) { 2682 offset = start_offset; 2683 *map_start = 0; 2684 } else { 2685 offset = 0; 2686 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset; 2687 } 2688 if (start + min_len > eb->len) { 2689 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); 2690 WARN_ON(1); 2691 } 2692 2693 p = extent_buffer_page(eb, i); 2694 WARN_ON(!PageUptodate(p)); 2695 kaddr = kmap_atomic(p, km); 2696 *token = kaddr; 2697 *map = kaddr + offset; 2698 *map_len = PAGE_CACHE_SIZE - offset; 2699 return 0; 2700 } 2701 EXPORT_SYMBOL(map_private_extent_buffer); 2702 2703 int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 2704 unsigned long min_len, 2705 char **token, char **map, 2706 unsigned long *map_start, 2707 unsigned long *map_len, int km) 2708 { 2709 int err; 2710 int save = 0; 2711 if (eb->map_token) { 2712 unmap_extent_buffer(eb, eb->map_token, km); 2713 eb->map_token = NULL; 2714 save = 1; 2715 } 2716 err = map_private_extent_buffer(eb, start, min_len, token, map, 2717 map_start, map_len, km); 2718 if (!err && save) { 2719 eb->map_token = *token; 2720 eb->kaddr = *map; 2721 eb->map_start = *map_start; 2722 eb->map_len = *map_len; 2723 } 2724 return err; 2725 } 2726 EXPORT_SYMBOL(map_extent_buffer); 2727 2728 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) 2729 { 2730 kunmap_atomic(token, km); 2731 } 2732 EXPORT_SYMBOL(unmap_extent_buffer); 2733 2734 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 2735 unsigned long start, 2736 unsigned long len) 2737 { 2738 size_t cur; 2739 size_t offset; 2740 struct page *page; 2741 char *kaddr; 2742 char *ptr = (char *)ptrv; 2743 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2744 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2745 int ret = 0; 2746 2747 WARN_ON(start > eb->len); 2748 WARN_ON(start + len > eb->start + eb->len); 2749 2750 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2751 2752 while(len > 0) { 2753 page = extent_buffer_page(eb, i); 2754 WARN_ON(!PageUptodate(page)); 2755 2756 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2757 2758 kaddr = kmap_atomic(page, KM_USER0); 2759 ret = memcmp(ptr, kaddr + offset, cur); 2760 kunmap_atomic(kaddr, KM_USER0); 2761 if (ret) 2762 break; 2763 2764 ptr += cur; 2765 len -= cur; 2766 offset = 0; 2767 i++; 2768 } 2769 return ret; 2770 } 2771 EXPORT_SYMBOL(memcmp_extent_buffer); 2772 2773 void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 2774 unsigned long start, unsigned long len) 2775 { 2776 size_t cur; 2777 size_t offset; 2778 struct page *page; 2779 char *kaddr; 2780 char *src = (char *)srcv; 2781 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2782 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2783 2784 WARN_ON(start > eb->len); 2785 WARN_ON(start + len > eb->start + eb->len); 2786 2787 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2788 2789 while(len > 0) { 2790 page = extent_buffer_page(eb, i); 2791 WARN_ON(!PageUptodate(page)); 2792 2793 cur = min(len, PAGE_CACHE_SIZE - offset); 2794 kaddr = kmap_atomic(page, KM_USER1); 2795 memcpy(kaddr + offset, src, cur); 2796 kunmap_atomic(kaddr, KM_USER1); 2797 2798 src += cur; 2799 len -= cur; 2800 offset = 0; 2801 i++; 2802 } 2803 } 2804 EXPORT_SYMBOL(write_extent_buffer); 2805 2806 void memset_extent_buffer(struct extent_buffer *eb, char c, 2807 unsigned long start, unsigned long len) 2808 { 2809 size_t cur; 2810 size_t offset; 2811 struct page *page; 2812 char *kaddr; 2813 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2814 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2815 2816 WARN_ON(start > eb->len); 2817 WARN_ON(start + len > eb->start + eb->len); 2818 2819 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2820 2821 while(len > 0) { 2822 page = extent_buffer_page(eb, i); 2823 WARN_ON(!PageUptodate(page)); 2824 2825 cur = min(len, PAGE_CACHE_SIZE - offset); 2826 kaddr = kmap_atomic(page, KM_USER0); 2827 memset(kaddr + offset, c, cur); 2828 kunmap_atomic(kaddr, KM_USER0); 2829 2830 len -= cur; 2831 offset = 0; 2832 i++; 2833 } 2834 } 2835 EXPORT_SYMBOL(memset_extent_buffer); 2836 2837 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 2838 unsigned long dst_offset, unsigned long src_offset, 2839 unsigned long len) 2840 { 2841 u64 dst_len = dst->len; 2842 size_t cur; 2843 size_t offset; 2844 struct page *page; 2845 char *kaddr; 2846 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2847 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2848 2849 WARN_ON(src->len != dst_len); 2850 2851 offset = (start_offset + dst_offset) & 2852 ((unsigned long)PAGE_CACHE_SIZE - 1); 2853 2854 while(len > 0) { 2855 page = extent_buffer_page(dst, i); 2856 WARN_ON(!PageUptodate(page)); 2857 2858 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset)); 2859 2860 kaddr = kmap_atomic(page, KM_USER0); 2861 read_extent_buffer(src, kaddr + offset, src_offset, cur); 2862 kunmap_atomic(kaddr, KM_USER0); 2863 2864 src_offset += cur; 2865 len -= cur; 2866 offset = 0; 2867 i++; 2868 } 2869 } 2870 EXPORT_SYMBOL(copy_extent_buffer); 2871 2872 static void move_pages(struct page *dst_page, struct page *src_page, 2873 unsigned long dst_off, unsigned long src_off, 2874 unsigned long len) 2875 { 2876 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2877 if (dst_page == src_page) { 2878 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len); 2879 } else { 2880 char *src_kaddr = kmap_atomic(src_page, KM_USER1); 2881 char *p = dst_kaddr + dst_off + len; 2882 char *s = src_kaddr + src_off + len; 2883 2884 while (len--) 2885 *--p = *--s; 2886 2887 kunmap_atomic(src_kaddr, KM_USER1); 2888 } 2889 kunmap_atomic(dst_kaddr, KM_USER0); 2890 } 2891 2892 static void copy_pages(struct page *dst_page, struct page *src_page, 2893 unsigned long dst_off, unsigned long src_off, 2894 unsigned long len) 2895 { 2896 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2897 char *src_kaddr; 2898 2899 if (dst_page != src_page) 2900 src_kaddr = kmap_atomic(src_page, KM_USER1); 2901 else 2902 src_kaddr = dst_kaddr; 2903 2904 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); 2905 kunmap_atomic(dst_kaddr, KM_USER0); 2906 if (dst_page != src_page) 2907 kunmap_atomic(src_kaddr, KM_USER1); 2908 } 2909 2910 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2911 unsigned long src_offset, unsigned long len) 2912 { 2913 size_t cur; 2914 size_t dst_off_in_page; 2915 size_t src_off_in_page; 2916 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2917 unsigned long dst_i; 2918 unsigned long src_i; 2919 2920 if (src_offset + len > dst->len) { 2921 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2922 src_offset, len, dst->len); 2923 BUG_ON(1); 2924 } 2925 if (dst_offset + len > dst->len) { 2926 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2927 dst_offset, len, dst->len); 2928 BUG_ON(1); 2929 } 2930 2931 while(len > 0) { 2932 dst_off_in_page = (start_offset + dst_offset) & 2933 ((unsigned long)PAGE_CACHE_SIZE - 1); 2934 src_off_in_page = (start_offset + src_offset) & 2935 ((unsigned long)PAGE_CACHE_SIZE - 1); 2936 2937 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2938 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT; 2939 2940 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - 2941 src_off_in_page)); 2942 cur = min_t(unsigned long, cur, 2943 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page)); 2944 2945 copy_pages(extent_buffer_page(dst, dst_i), 2946 extent_buffer_page(dst, src_i), 2947 dst_off_in_page, src_off_in_page, cur); 2948 2949 src_offset += cur; 2950 dst_offset += cur; 2951 len -= cur; 2952 } 2953 } 2954 EXPORT_SYMBOL(memcpy_extent_buffer); 2955 2956 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2957 unsigned long src_offset, unsigned long len) 2958 { 2959 size_t cur; 2960 size_t dst_off_in_page; 2961 size_t src_off_in_page; 2962 unsigned long dst_end = dst_offset + len - 1; 2963 unsigned long src_end = src_offset + len - 1; 2964 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2965 unsigned long dst_i; 2966 unsigned long src_i; 2967 2968 if (src_offset + len > dst->len) { 2969 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2970 src_offset, len, dst->len); 2971 BUG_ON(1); 2972 } 2973 if (dst_offset + len > dst->len) { 2974 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2975 dst_offset, len, dst->len); 2976 BUG_ON(1); 2977 } 2978 if (dst_offset < src_offset) { 2979 memcpy_extent_buffer(dst, dst_offset, src_offset, len); 2980 return; 2981 } 2982 while(len > 0) { 2983 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT; 2984 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT; 2985 2986 dst_off_in_page = (start_offset + dst_end) & 2987 ((unsigned long)PAGE_CACHE_SIZE - 1); 2988 src_off_in_page = (start_offset + src_end) & 2989 ((unsigned long)PAGE_CACHE_SIZE - 1); 2990 2991 cur = min_t(unsigned long, len, src_off_in_page + 1); 2992 cur = min(cur, dst_off_in_page + 1); 2993 move_pages(extent_buffer_page(dst, dst_i), 2994 extent_buffer_page(dst, src_i), 2995 dst_off_in_page - cur + 1, 2996 src_off_in_page - cur + 1, cur); 2997 2998 dst_end -= cur; 2999 src_end -= cur; 3000 len -= cur; 3001 } 3002 } 3003 EXPORT_SYMBOL(memmove_extent_buffer); 3004