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 46 int __init extent_map_init(void) 47 { 48 extent_map_cache = btrfs_cache_create("extent_map", 49 sizeof(struct extent_map), 0, 50 NULL); 51 if (!extent_map_cache) 52 return -ENOMEM; 53 extent_state_cache = btrfs_cache_create("extent_state", 54 sizeof(struct extent_state), 0, 55 NULL); 56 if (!extent_state_cache) 57 goto free_map_cache; 58 extent_buffer_cache = btrfs_cache_create("extent_buffers", 59 sizeof(struct extent_buffer), 0, 60 NULL); 61 if (!extent_buffer_cache) 62 goto free_state_cache; 63 return 0; 64 65 free_state_cache: 66 kmem_cache_destroy(extent_state_cache); 67 free_map_cache: 68 kmem_cache_destroy(extent_map_cache); 69 return -ENOMEM; 70 } 71 72 void extent_map_exit(void) 73 { 74 struct extent_state *state; 75 76 while (!list_empty(&states)) { 77 state = list_entry(states.next, struct extent_state, list); 78 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)); 79 list_del(&state->list); 80 kmem_cache_free(extent_state_cache, state); 81 82 } 83 84 if (extent_map_cache) 85 kmem_cache_destroy(extent_map_cache); 86 if (extent_state_cache) 87 kmem_cache_destroy(extent_state_cache); 88 if (extent_buffer_cache) 89 kmem_cache_destroy(extent_buffer_cache); 90 } 91 92 void extent_map_tree_init(struct extent_map_tree *tree, 93 struct address_space *mapping, gfp_t mask) 94 { 95 tree->map.rb_node = NULL; 96 tree->state.rb_node = NULL; 97 tree->ops = NULL; 98 tree->dirty_bytes = 0; 99 rwlock_init(&tree->lock); 100 spin_lock_init(&tree->lru_lock); 101 tree->mapping = mapping; 102 INIT_LIST_HEAD(&tree->buffer_lru); 103 tree->lru_size = 0; 104 } 105 EXPORT_SYMBOL(extent_map_tree_init); 106 107 void extent_map_tree_empty_lru(struct extent_map_tree *tree) 108 { 109 struct extent_buffer *eb; 110 while(!list_empty(&tree->buffer_lru)) { 111 eb = list_entry(tree->buffer_lru.next, struct extent_buffer, 112 lru); 113 list_del_init(&eb->lru); 114 free_extent_buffer(eb); 115 } 116 } 117 EXPORT_SYMBOL(extent_map_tree_empty_lru); 118 119 struct extent_map *alloc_extent_map(gfp_t mask) 120 { 121 struct extent_map *em; 122 em = kmem_cache_alloc(extent_map_cache, mask); 123 if (!em || IS_ERR(em)) 124 return em; 125 em->in_tree = 0; 126 atomic_set(&em->refs, 1); 127 return em; 128 } 129 EXPORT_SYMBOL(alloc_extent_map); 130 131 void free_extent_map(struct extent_map *em) 132 { 133 if (!em) 134 return; 135 if (atomic_dec_and_test(&em->refs)) { 136 WARN_ON(em->in_tree); 137 kmem_cache_free(extent_map_cache, em); 138 } 139 } 140 EXPORT_SYMBOL(free_extent_map); 141 142 143 struct extent_state *alloc_extent_state(gfp_t mask) 144 { 145 struct extent_state *state; 146 unsigned long flags; 147 148 state = kmem_cache_alloc(extent_state_cache, mask); 149 if (!state || IS_ERR(state)) 150 return state; 151 state->state = 0; 152 state->in_tree = 0; 153 state->private = 0; 154 155 spin_lock_irqsave(&state_lock, flags); 156 list_add(&state->list, &states); 157 spin_unlock_irqrestore(&state_lock, flags); 158 159 atomic_set(&state->refs, 1); 160 init_waitqueue_head(&state->wq); 161 return state; 162 } 163 EXPORT_SYMBOL(alloc_extent_state); 164 165 void free_extent_state(struct extent_state *state) 166 { 167 unsigned long flags; 168 if (!state) 169 return; 170 if (atomic_dec_and_test(&state->refs)) { 171 WARN_ON(state->in_tree); 172 spin_lock_irqsave(&state_lock, flags); 173 list_del(&state->list); 174 spin_unlock_irqrestore(&state_lock, flags); 175 kmem_cache_free(extent_state_cache, state); 176 } 177 } 178 EXPORT_SYMBOL(free_extent_state); 179 180 static struct rb_node *tree_insert(struct rb_root *root, u64 offset, 181 struct rb_node *node) 182 { 183 struct rb_node ** p = &root->rb_node; 184 struct rb_node * parent = NULL; 185 struct tree_entry *entry; 186 187 while(*p) { 188 parent = *p; 189 entry = rb_entry(parent, struct tree_entry, rb_node); 190 191 if (offset < entry->start) 192 p = &(*p)->rb_left; 193 else if (offset > entry->end) 194 p = &(*p)->rb_right; 195 else 196 return parent; 197 } 198 199 entry = rb_entry(node, struct tree_entry, rb_node); 200 entry->in_tree = 1; 201 rb_link_node(node, parent, p); 202 rb_insert_color(node, root); 203 return NULL; 204 } 205 206 static struct rb_node *__tree_search(struct rb_root *root, u64 offset, 207 struct rb_node **prev_ret) 208 { 209 struct rb_node * n = root->rb_node; 210 struct rb_node *prev = NULL; 211 struct tree_entry *entry; 212 struct tree_entry *prev_entry = NULL; 213 214 while(n) { 215 entry = rb_entry(n, struct tree_entry, rb_node); 216 prev = n; 217 prev_entry = entry; 218 219 if (offset < entry->start) 220 n = n->rb_left; 221 else if (offset > entry->end) 222 n = n->rb_right; 223 else 224 return n; 225 } 226 if (!prev_ret) 227 return NULL; 228 while(prev && offset > prev_entry->end) { 229 prev = rb_next(prev); 230 prev_entry = rb_entry(prev, struct tree_entry, rb_node); 231 } 232 *prev_ret = prev; 233 return NULL; 234 } 235 236 static inline struct rb_node *tree_search(struct rb_root *root, u64 offset) 237 { 238 struct rb_node *prev; 239 struct rb_node *ret; 240 ret = __tree_search(root, offset, &prev); 241 if (!ret) 242 return prev; 243 return ret; 244 } 245 246 static int tree_delete(struct rb_root *root, u64 offset) 247 { 248 struct rb_node *node; 249 struct tree_entry *entry; 250 251 node = __tree_search(root, offset, NULL); 252 if (!node) 253 return -ENOENT; 254 entry = rb_entry(node, struct tree_entry, rb_node); 255 entry->in_tree = 0; 256 rb_erase(node, root); 257 return 0; 258 } 259 260 /* 261 * add_extent_mapping tries a simple backward merge with existing 262 * mappings. The extent_map struct passed in will be inserted into 263 * the tree directly (no copies made, just a reference taken). 264 */ 265 int add_extent_mapping(struct extent_map_tree *tree, 266 struct extent_map *em) 267 { 268 int ret = 0; 269 struct extent_map *prev = NULL; 270 struct rb_node *rb; 271 272 write_lock_irq(&tree->lock); 273 rb = tree_insert(&tree->map, em->end, &em->rb_node); 274 if (rb) { 275 prev = rb_entry(rb, struct extent_map, rb_node); 276 printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev->start, prev->end, em->start, em->end); 277 ret = -EEXIST; 278 goto out; 279 } 280 atomic_inc(&em->refs); 281 if (em->start != 0) { 282 rb = rb_prev(&em->rb_node); 283 if (rb) 284 prev = rb_entry(rb, struct extent_map, rb_node); 285 if (prev && prev->end + 1 == em->start && 286 ((em->block_start == EXTENT_MAP_HOLE && 287 prev->block_start == EXTENT_MAP_HOLE) || 288 (em->block_start == EXTENT_MAP_INLINE && 289 prev->block_start == EXTENT_MAP_INLINE) || 290 (em->block_start == EXTENT_MAP_DELALLOC && 291 prev->block_start == EXTENT_MAP_DELALLOC) || 292 (em->block_start < EXTENT_MAP_DELALLOC - 1 && 293 em->block_start == prev->block_end + 1))) { 294 em->start = prev->start; 295 em->block_start = prev->block_start; 296 rb_erase(&prev->rb_node, &tree->map); 297 prev->in_tree = 0; 298 free_extent_map(prev); 299 } 300 } 301 out: 302 write_unlock_irq(&tree->lock); 303 return ret; 304 } 305 EXPORT_SYMBOL(add_extent_mapping); 306 307 /* 308 * lookup_extent_mapping returns the first extent_map struct in the 309 * tree that intersects the [start, end] (inclusive) range. There may 310 * be additional objects in the tree that intersect, so check the object 311 * returned carefully to make sure you don't need additional lookups. 312 */ 313 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, 314 u64 start, u64 end) 315 { 316 struct extent_map *em; 317 struct rb_node *rb_node; 318 319 read_lock_irq(&tree->lock); 320 rb_node = tree_search(&tree->map, start); 321 if (!rb_node) { 322 em = NULL; 323 goto out; 324 } 325 if (IS_ERR(rb_node)) { 326 em = ERR_PTR(PTR_ERR(rb_node)); 327 goto out; 328 } 329 em = rb_entry(rb_node, struct extent_map, rb_node); 330 if (em->end < start || em->start > end) { 331 em = NULL; 332 goto out; 333 } 334 atomic_inc(&em->refs); 335 out: 336 read_unlock_irq(&tree->lock); 337 return em; 338 } 339 EXPORT_SYMBOL(lookup_extent_mapping); 340 341 /* 342 * removes an extent_map struct from the tree. No reference counts are 343 * dropped, and no checks are done to see if the range is in use 344 */ 345 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) 346 { 347 int ret; 348 349 write_lock_irq(&tree->lock); 350 ret = tree_delete(&tree->map, em->end); 351 write_unlock_irq(&tree->lock); 352 return ret; 353 } 354 EXPORT_SYMBOL(remove_extent_mapping); 355 356 /* 357 * utility function to look for merge candidates inside a given range. 358 * Any extents with matching state are merged together into a single 359 * extent in the tree. Extents with EXTENT_IO in their state field 360 * are not merged because the end_io handlers need to be able to do 361 * operations on them without sleeping (or doing allocations/splits). 362 * 363 * This should be called with the tree lock held. 364 */ 365 static int merge_state(struct extent_map_tree *tree, 366 struct extent_state *state) 367 { 368 struct extent_state *other; 369 struct rb_node *other_node; 370 371 if (state->state & EXTENT_IOBITS) 372 return 0; 373 374 other_node = rb_prev(&state->rb_node); 375 if (other_node) { 376 other = rb_entry(other_node, struct extent_state, rb_node); 377 if (other->end == state->start - 1 && 378 other->state == state->state) { 379 state->start = other->start; 380 other->in_tree = 0; 381 rb_erase(&other->rb_node, &tree->state); 382 free_extent_state(other); 383 } 384 } 385 other_node = rb_next(&state->rb_node); 386 if (other_node) { 387 other = rb_entry(other_node, struct extent_state, rb_node); 388 if (other->start == state->end + 1 && 389 other->state == state->state) { 390 other->start = state->start; 391 state->in_tree = 0; 392 rb_erase(&state->rb_node, &tree->state); 393 free_extent_state(state); 394 } 395 } 396 return 0; 397 } 398 399 /* 400 * insert an extent_state struct into the tree. 'bits' are set on the 401 * struct before it is inserted. 402 * 403 * This may return -EEXIST if the extent is already there, in which case the 404 * state struct is freed. 405 * 406 * The tree lock is not taken internally. This is a utility function and 407 * probably isn't what you want to call (see set/clear_extent_bit). 408 */ 409 static int insert_state(struct extent_map_tree *tree, 410 struct extent_state *state, u64 start, u64 end, 411 int bits) 412 { 413 struct rb_node *node; 414 415 if (end < start) { 416 printk("end < start %Lu %Lu\n", end, start); 417 WARN_ON(1); 418 } 419 if (bits & EXTENT_DIRTY) 420 tree->dirty_bytes += end - start + 1; 421 state->state |= bits; 422 state->start = start; 423 state->end = end; 424 node = tree_insert(&tree->state, end, &state->rb_node); 425 if (node) { 426 struct extent_state *found; 427 found = rb_entry(node, struct extent_state, rb_node); 428 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end); 429 free_extent_state(state); 430 return -EEXIST; 431 } 432 merge_state(tree, state); 433 return 0; 434 } 435 436 /* 437 * split a given extent state struct in two, inserting the preallocated 438 * struct 'prealloc' as the newly created second half. 'split' indicates an 439 * offset inside 'orig' where it should be split. 440 * 441 * Before calling, 442 * the tree has 'orig' at [orig->start, orig->end]. After calling, there 443 * are two extent state structs in the tree: 444 * prealloc: [orig->start, split - 1] 445 * orig: [ split, orig->end ] 446 * 447 * The tree locks are not taken by this function. They need to be held 448 * by the caller. 449 */ 450 static int split_state(struct extent_map_tree *tree, struct extent_state *orig, 451 struct extent_state *prealloc, u64 split) 452 { 453 struct rb_node *node; 454 prealloc->start = orig->start; 455 prealloc->end = split - 1; 456 prealloc->state = orig->state; 457 orig->start = split; 458 459 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node); 460 if (node) { 461 struct extent_state *found; 462 found = rb_entry(node, struct extent_state, rb_node); 463 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end); 464 free_extent_state(prealloc); 465 return -EEXIST; 466 } 467 return 0; 468 } 469 470 /* 471 * utility function to clear some bits in an extent state struct. 472 * it will optionally wake up any one waiting on this state (wake == 1), or 473 * forcibly remove the state from the tree (delete == 1). 474 * 475 * If no bits are set on the state struct after clearing things, the 476 * struct is freed and removed from the tree 477 */ 478 static int clear_state_bit(struct extent_map_tree *tree, 479 struct extent_state *state, int bits, int wake, 480 int delete) 481 { 482 int ret = state->state & bits; 483 484 if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) { 485 u64 range = state->end - state->start + 1; 486 WARN_ON(range > tree->dirty_bytes); 487 tree->dirty_bytes -= range; 488 } 489 state->state &= ~bits; 490 if (wake) 491 wake_up(&state->wq); 492 if (delete || state->state == 0) { 493 if (state->in_tree) { 494 rb_erase(&state->rb_node, &tree->state); 495 state->in_tree = 0; 496 free_extent_state(state); 497 } else { 498 WARN_ON(1); 499 } 500 } else { 501 merge_state(tree, state); 502 } 503 return ret; 504 } 505 506 /* 507 * clear some bits on a range in the tree. This may require splitting 508 * or inserting elements in the tree, so the gfp mask is used to 509 * indicate which allocations or sleeping are allowed. 510 * 511 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove 512 * the given range from the tree regardless of state (ie for truncate). 513 * 514 * the range [start, end] is inclusive. 515 * 516 * This takes the tree lock, and returns < 0 on error, > 0 if any of the 517 * bits were already set, or zero if none of the bits were already set. 518 */ 519 int clear_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, 520 int bits, int wake, int delete, gfp_t mask) 521 { 522 struct extent_state *state; 523 struct extent_state *prealloc = NULL; 524 struct rb_node *node; 525 unsigned long flags; 526 int err; 527 int set = 0; 528 529 again: 530 if (!prealloc && (mask & __GFP_WAIT)) { 531 prealloc = alloc_extent_state(mask); 532 if (!prealloc) 533 return -ENOMEM; 534 } 535 536 write_lock_irqsave(&tree->lock, flags); 537 /* 538 * this search will find the extents that end after 539 * our range starts 540 */ 541 node = tree_search(&tree->state, start); 542 if (!node) 543 goto out; 544 state = rb_entry(node, struct extent_state, rb_node); 545 if (state->start > end) 546 goto out; 547 WARN_ON(state->end < start); 548 549 /* 550 * | ---- desired range ---- | 551 * | state | or 552 * | ------------- state -------------- | 553 * 554 * We need to split the extent we found, and may flip 555 * bits on second half. 556 * 557 * If the extent we found extends past our range, we 558 * just split and search again. It'll get split again 559 * the next time though. 560 * 561 * If the extent we found is inside our range, we clear 562 * the desired bit on it. 563 */ 564 565 if (state->start < start) { 566 err = split_state(tree, state, prealloc, start); 567 BUG_ON(err == -EEXIST); 568 prealloc = NULL; 569 if (err) 570 goto out; 571 if (state->end <= end) { 572 start = state->end + 1; 573 set |= clear_state_bit(tree, state, bits, 574 wake, delete); 575 } else { 576 start = state->start; 577 } 578 goto search_again; 579 } 580 /* 581 * | ---- desired range ---- | 582 * | state | 583 * We need to split the extent, and clear the bit 584 * on the first half 585 */ 586 if (state->start <= end && state->end > end) { 587 err = split_state(tree, state, prealloc, end + 1); 588 BUG_ON(err == -EEXIST); 589 590 if (wake) 591 wake_up(&state->wq); 592 set |= clear_state_bit(tree, prealloc, bits, 593 wake, delete); 594 prealloc = NULL; 595 goto out; 596 } 597 598 start = state->end + 1; 599 set |= clear_state_bit(tree, state, bits, wake, delete); 600 goto search_again; 601 602 out: 603 write_unlock_irqrestore(&tree->lock, flags); 604 if (prealloc) 605 free_extent_state(prealloc); 606 607 return set; 608 609 search_again: 610 if (start > end) 611 goto out; 612 write_unlock_irqrestore(&tree->lock, flags); 613 if (mask & __GFP_WAIT) 614 cond_resched(); 615 goto again; 616 } 617 EXPORT_SYMBOL(clear_extent_bit); 618 619 static int wait_on_state(struct extent_map_tree *tree, 620 struct extent_state *state) 621 { 622 DEFINE_WAIT(wait); 623 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); 624 read_unlock_irq(&tree->lock); 625 schedule(); 626 read_lock_irq(&tree->lock); 627 finish_wait(&state->wq, &wait); 628 return 0; 629 } 630 631 /* 632 * waits for one or more bits to clear on a range in the state tree. 633 * The range [start, end] is inclusive. 634 * The tree lock is taken by this function 635 */ 636 int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits) 637 { 638 struct extent_state *state; 639 struct rb_node *node; 640 641 read_lock_irq(&tree->lock); 642 again: 643 while (1) { 644 /* 645 * this search will find all the extents that end after 646 * our range starts 647 */ 648 node = tree_search(&tree->state, start); 649 if (!node) 650 break; 651 652 state = rb_entry(node, struct extent_state, rb_node); 653 654 if (state->start > end) 655 goto out; 656 657 if (state->state & bits) { 658 start = state->start; 659 atomic_inc(&state->refs); 660 wait_on_state(tree, state); 661 free_extent_state(state); 662 goto again; 663 } 664 start = state->end + 1; 665 666 if (start > end) 667 break; 668 669 if (need_resched()) { 670 read_unlock_irq(&tree->lock); 671 cond_resched(); 672 read_lock_irq(&tree->lock); 673 } 674 } 675 out: 676 read_unlock_irq(&tree->lock); 677 return 0; 678 } 679 EXPORT_SYMBOL(wait_extent_bit); 680 681 static void set_state_bits(struct extent_map_tree *tree, 682 struct extent_state *state, 683 int bits) 684 { 685 if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) { 686 u64 range = state->end - state->start + 1; 687 tree->dirty_bytes += range; 688 } 689 state->state |= bits; 690 } 691 692 /* 693 * set some bits on a range in the tree. This may require allocations 694 * or sleeping, so the gfp mask is used to indicate what is allowed. 695 * 696 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the 697 * range already has the desired bits set. The start of the existing 698 * range is returned in failed_start in this case. 699 * 700 * [start, end] is inclusive 701 * This takes the tree lock. 702 */ 703 int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, 704 int exclusive, u64 *failed_start, gfp_t mask) 705 { 706 struct extent_state *state; 707 struct extent_state *prealloc = NULL; 708 struct rb_node *node; 709 unsigned long flags; 710 int err = 0; 711 int set; 712 u64 last_start; 713 u64 last_end; 714 again: 715 if (!prealloc && (mask & __GFP_WAIT)) { 716 prealloc = alloc_extent_state(mask); 717 if (!prealloc) 718 return -ENOMEM; 719 } 720 721 write_lock_irqsave(&tree->lock, flags); 722 /* 723 * this search will find all the extents that end after 724 * our range starts. 725 */ 726 node = tree_search(&tree->state, start); 727 if (!node) { 728 err = insert_state(tree, prealloc, start, end, bits); 729 prealloc = NULL; 730 BUG_ON(err == -EEXIST); 731 goto out; 732 } 733 734 state = rb_entry(node, struct extent_state, rb_node); 735 last_start = state->start; 736 last_end = state->end; 737 738 /* 739 * | ---- desired range ---- | 740 * | state | 741 * 742 * Just lock what we found and keep going 743 */ 744 if (state->start == start && state->end <= end) { 745 set = state->state & bits; 746 if (set && exclusive) { 747 *failed_start = state->start; 748 err = -EEXIST; 749 goto out; 750 } 751 set_state_bits(tree, state, bits); 752 start = state->end + 1; 753 merge_state(tree, state); 754 goto search_again; 755 } 756 757 /* 758 * | ---- desired range ---- | 759 * | state | 760 * or 761 * | ------------- state -------------- | 762 * 763 * We need to split the extent we found, and may flip bits on 764 * second half. 765 * 766 * If the extent we found extends past our 767 * range, we just split and search again. It'll get split 768 * again the next time though. 769 * 770 * If the extent we found is inside our range, we set the 771 * desired bit on it. 772 */ 773 if (state->start < start) { 774 set = state->state & bits; 775 if (exclusive && set) { 776 *failed_start = start; 777 err = -EEXIST; 778 goto out; 779 } 780 err = split_state(tree, state, prealloc, start); 781 BUG_ON(err == -EEXIST); 782 prealloc = NULL; 783 if (err) 784 goto out; 785 if (state->end <= end) { 786 set_state_bits(tree, state, bits); 787 start = state->end + 1; 788 merge_state(tree, state); 789 } else { 790 start = state->start; 791 } 792 goto search_again; 793 } 794 /* 795 * | ---- desired range ---- | 796 * | state | or | state | 797 * 798 * There's a hole, we need to insert something in it and 799 * ignore the extent we found. 800 */ 801 if (state->start > start) { 802 u64 this_end; 803 if (end < last_start) 804 this_end = end; 805 else 806 this_end = last_start -1; 807 err = insert_state(tree, prealloc, start, this_end, 808 bits); 809 prealloc = NULL; 810 BUG_ON(err == -EEXIST); 811 if (err) 812 goto out; 813 start = this_end + 1; 814 goto search_again; 815 } 816 /* 817 * | ---- desired range ---- | 818 * | state | 819 * We need to split the extent, and set the bit 820 * on the first half 821 */ 822 if (state->start <= end && state->end > end) { 823 set = state->state & bits; 824 if (exclusive && set) { 825 *failed_start = start; 826 err = -EEXIST; 827 goto out; 828 } 829 err = split_state(tree, state, prealloc, end + 1); 830 BUG_ON(err == -EEXIST); 831 832 set_state_bits(tree, prealloc, bits); 833 merge_state(tree, prealloc); 834 prealloc = NULL; 835 goto out; 836 } 837 838 goto search_again; 839 840 out: 841 write_unlock_irqrestore(&tree->lock, flags); 842 if (prealloc) 843 free_extent_state(prealloc); 844 845 return err; 846 847 search_again: 848 if (start > end) 849 goto out; 850 write_unlock_irqrestore(&tree->lock, flags); 851 if (mask & __GFP_WAIT) 852 cond_resched(); 853 goto again; 854 } 855 EXPORT_SYMBOL(set_extent_bit); 856 857 /* wrappers around set/clear extent bit */ 858 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 859 gfp_t mask) 860 { 861 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, 862 mask); 863 } 864 EXPORT_SYMBOL(set_extent_dirty); 865 866 int set_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 867 int bits, gfp_t mask) 868 { 869 return set_extent_bit(tree, start, end, bits, 0, NULL, 870 mask); 871 } 872 EXPORT_SYMBOL(set_extent_bits); 873 874 int clear_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 875 int bits, gfp_t mask) 876 { 877 return clear_extent_bit(tree, start, end, bits, 0, 0, mask); 878 } 879 EXPORT_SYMBOL(clear_extent_bits); 880 881 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end, 882 gfp_t mask) 883 { 884 return set_extent_bit(tree, start, end, 885 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL, 886 mask); 887 } 888 EXPORT_SYMBOL(set_extent_delalloc); 889 890 int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 891 gfp_t mask) 892 { 893 return clear_extent_bit(tree, start, end, 894 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask); 895 } 896 EXPORT_SYMBOL(clear_extent_dirty); 897 898 int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 899 gfp_t mask) 900 { 901 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, 902 mask); 903 } 904 EXPORT_SYMBOL(set_extent_new); 905 906 int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 907 gfp_t mask) 908 { 909 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask); 910 } 911 EXPORT_SYMBOL(clear_extent_new); 912 913 int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 914 gfp_t mask) 915 { 916 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL, 917 mask); 918 } 919 EXPORT_SYMBOL(set_extent_uptodate); 920 921 int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 922 gfp_t mask) 923 { 924 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask); 925 } 926 EXPORT_SYMBOL(clear_extent_uptodate); 927 928 int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 929 gfp_t mask) 930 { 931 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK, 932 0, NULL, mask); 933 } 934 EXPORT_SYMBOL(set_extent_writeback); 935 936 int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 937 gfp_t mask) 938 { 939 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask); 940 } 941 EXPORT_SYMBOL(clear_extent_writeback); 942 943 int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end) 944 { 945 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK); 946 } 947 EXPORT_SYMBOL(wait_on_extent_writeback); 948 949 /* 950 * locks a range in ascending order, waiting for any locked regions 951 * it hits on the way. [start,end] are inclusive, and this will sleep. 952 */ 953 int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask) 954 { 955 int err; 956 u64 failed_start; 957 while (1) { 958 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 959 &failed_start, mask); 960 if (err == -EEXIST && (mask & __GFP_WAIT)) { 961 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); 962 start = failed_start; 963 } else { 964 break; 965 } 966 WARN_ON(start > end); 967 } 968 return err; 969 } 970 EXPORT_SYMBOL(lock_extent); 971 972 int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, 973 gfp_t mask) 974 { 975 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask); 976 } 977 EXPORT_SYMBOL(unlock_extent); 978 979 /* 980 * helper function to set pages and extents in the tree dirty 981 */ 982 int set_range_dirty(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_dirty_nobuffers(page); 992 page_cache_release(page); 993 index++; 994 } 995 set_extent_dirty(tree, start, end, GFP_NOFS); 996 return 0; 997 } 998 EXPORT_SYMBOL(set_range_dirty); 999 1000 /* 1001 * helper function to set both pages and extents in the tree writeback 1002 */ 1003 int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end) 1004 { 1005 unsigned long index = start >> PAGE_CACHE_SHIFT; 1006 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1007 struct page *page; 1008 1009 while (index <= end_index) { 1010 page = find_get_page(tree->mapping, index); 1011 BUG_ON(!page); 1012 set_page_writeback(page); 1013 page_cache_release(page); 1014 index++; 1015 } 1016 set_extent_writeback(tree, start, end, GFP_NOFS); 1017 return 0; 1018 } 1019 EXPORT_SYMBOL(set_range_writeback); 1020 1021 int find_first_extent_bit(struct extent_map_tree *tree, u64 start, 1022 u64 *start_ret, u64 *end_ret, int bits) 1023 { 1024 struct rb_node *node; 1025 struct extent_state *state; 1026 int ret = 1; 1027 1028 read_lock_irq(&tree->lock); 1029 /* 1030 * this search will find all the extents that end after 1031 * our range starts. 1032 */ 1033 node = tree_search(&tree->state, start); 1034 if (!node || IS_ERR(node)) { 1035 goto out; 1036 } 1037 1038 while(1) { 1039 state = rb_entry(node, struct extent_state, rb_node); 1040 if (state->end >= start && (state->state & bits)) { 1041 *start_ret = state->start; 1042 *end_ret = state->end; 1043 ret = 0; 1044 break; 1045 } 1046 node = rb_next(node); 1047 if (!node) 1048 break; 1049 } 1050 out: 1051 read_unlock_irq(&tree->lock); 1052 return ret; 1053 } 1054 EXPORT_SYMBOL(find_first_extent_bit); 1055 1056 u64 find_lock_delalloc_range(struct extent_map_tree *tree, 1057 u64 *start, u64 *end, u64 max_bytes) 1058 { 1059 struct rb_node *node; 1060 struct extent_state *state; 1061 u64 cur_start = *start; 1062 u64 found = 0; 1063 u64 total_bytes = 0; 1064 1065 write_lock_irq(&tree->lock); 1066 /* 1067 * this search will find all the extents that end after 1068 * our range starts. 1069 */ 1070 search_again: 1071 node = tree_search(&tree->state, cur_start); 1072 if (!node || IS_ERR(node)) { 1073 goto out; 1074 } 1075 1076 while(1) { 1077 state = rb_entry(node, struct extent_state, rb_node); 1078 if (found && state->start != cur_start) { 1079 goto out; 1080 } 1081 if (!(state->state & EXTENT_DELALLOC)) { 1082 goto out; 1083 } 1084 if (!found) { 1085 struct extent_state *prev_state; 1086 struct rb_node *prev_node = node; 1087 while(1) { 1088 prev_node = rb_prev(prev_node); 1089 if (!prev_node) 1090 break; 1091 prev_state = rb_entry(prev_node, 1092 struct extent_state, 1093 rb_node); 1094 if (!(prev_state->state & EXTENT_DELALLOC)) 1095 break; 1096 state = prev_state; 1097 node = prev_node; 1098 } 1099 } 1100 if (state->state & EXTENT_LOCKED) { 1101 DEFINE_WAIT(wait); 1102 atomic_inc(&state->refs); 1103 prepare_to_wait(&state->wq, &wait, 1104 TASK_UNINTERRUPTIBLE); 1105 write_unlock_irq(&tree->lock); 1106 schedule(); 1107 write_lock_irq(&tree->lock); 1108 finish_wait(&state->wq, &wait); 1109 free_extent_state(state); 1110 goto search_again; 1111 } 1112 state->state |= EXTENT_LOCKED; 1113 if (!found) 1114 *start = state->start; 1115 found++; 1116 *end = state->end; 1117 cur_start = state->end + 1; 1118 node = rb_next(node); 1119 if (!node) 1120 break; 1121 total_bytes += state->end - state->start + 1; 1122 if (total_bytes >= max_bytes) 1123 break; 1124 } 1125 out: 1126 write_unlock_irq(&tree->lock); 1127 return found; 1128 } 1129 1130 u64 count_range_bits(struct extent_map_tree *tree, 1131 u64 *start, u64 max_bytes, unsigned long bits) 1132 { 1133 struct rb_node *node; 1134 struct extent_state *state; 1135 u64 cur_start = *start; 1136 u64 total_bytes = 0; 1137 int found = 0; 1138 1139 write_lock_irq(&tree->lock); 1140 if (bits == EXTENT_DIRTY) { 1141 *start = 0; 1142 total_bytes = tree->dirty_bytes; 1143 goto out; 1144 } 1145 /* 1146 * this search will find all the extents that end after 1147 * our range starts. 1148 */ 1149 node = tree_search(&tree->state, cur_start); 1150 if (!node || IS_ERR(node)) { 1151 goto out; 1152 } 1153 1154 while(1) { 1155 state = rb_entry(node, struct extent_state, rb_node); 1156 if ((state->state & bits)) { 1157 total_bytes += state->end - state->start + 1; 1158 if (total_bytes >= max_bytes) 1159 break; 1160 if (!found) { 1161 *start = state->start; 1162 found = 1; 1163 } 1164 } 1165 node = rb_next(node); 1166 if (!node) 1167 break; 1168 } 1169 out: 1170 write_unlock_irq(&tree->lock); 1171 return total_bytes; 1172 } 1173 1174 /* 1175 * helper function to lock both pages and extents in the tree. 1176 * pages must be locked first. 1177 */ 1178 int lock_range(struct extent_map_tree *tree, u64 start, u64 end) 1179 { 1180 unsigned long index = start >> PAGE_CACHE_SHIFT; 1181 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1182 struct page *page; 1183 int err; 1184 1185 while (index <= end_index) { 1186 page = grab_cache_page(tree->mapping, index); 1187 if (!page) { 1188 err = -ENOMEM; 1189 goto failed; 1190 } 1191 if (IS_ERR(page)) { 1192 err = PTR_ERR(page); 1193 goto failed; 1194 } 1195 index++; 1196 } 1197 lock_extent(tree, start, end, GFP_NOFS); 1198 return 0; 1199 1200 failed: 1201 /* 1202 * we failed above in getting the page at 'index', so we undo here 1203 * up to but not including the page at 'index' 1204 */ 1205 end_index = index; 1206 index = start >> PAGE_CACHE_SHIFT; 1207 while (index < end_index) { 1208 page = find_get_page(tree->mapping, index); 1209 unlock_page(page); 1210 page_cache_release(page); 1211 index++; 1212 } 1213 return err; 1214 } 1215 EXPORT_SYMBOL(lock_range); 1216 1217 /* 1218 * helper function to unlock both pages and extents in the tree. 1219 */ 1220 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end) 1221 { 1222 unsigned long index = start >> PAGE_CACHE_SHIFT; 1223 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1224 struct page *page; 1225 1226 while (index <= end_index) { 1227 page = find_get_page(tree->mapping, index); 1228 unlock_page(page); 1229 page_cache_release(page); 1230 index++; 1231 } 1232 unlock_extent(tree, start, end, GFP_NOFS); 1233 return 0; 1234 } 1235 EXPORT_SYMBOL(unlock_range); 1236 1237 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private) 1238 { 1239 struct rb_node *node; 1240 struct extent_state *state; 1241 int ret = 0; 1242 1243 write_lock_irq(&tree->lock); 1244 /* 1245 * this search will find all the extents that end after 1246 * our range starts. 1247 */ 1248 node = tree_search(&tree->state, start); 1249 if (!node || IS_ERR(node)) { 1250 ret = -ENOENT; 1251 goto out; 1252 } 1253 state = rb_entry(node, struct extent_state, rb_node); 1254 if (state->start != start) { 1255 ret = -ENOENT; 1256 goto out; 1257 } 1258 state->private = private; 1259 out: 1260 write_unlock_irq(&tree->lock); 1261 return ret; 1262 } 1263 1264 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private) 1265 { 1266 struct rb_node *node; 1267 struct extent_state *state; 1268 int ret = 0; 1269 1270 read_lock_irq(&tree->lock); 1271 /* 1272 * this search will find all the extents that end after 1273 * our range starts. 1274 */ 1275 node = tree_search(&tree->state, start); 1276 if (!node || IS_ERR(node)) { 1277 ret = -ENOENT; 1278 goto out; 1279 } 1280 state = rb_entry(node, struct extent_state, rb_node); 1281 if (state->start != start) { 1282 ret = -ENOENT; 1283 goto out; 1284 } 1285 *private = state->private; 1286 out: 1287 read_unlock_irq(&tree->lock); 1288 return ret; 1289 } 1290 1291 /* 1292 * searches a range in the state tree for a given mask. 1293 * If 'filled' == 1, this returns 1 only if ever extent in the tree 1294 * has the bits set. Otherwise, 1 is returned if any bit in the 1295 * range is found set. 1296 */ 1297 int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end, 1298 int bits, int filled) 1299 { 1300 struct extent_state *state = NULL; 1301 struct rb_node *node; 1302 int bitset = 0; 1303 1304 read_lock_irq(&tree->lock); 1305 node = tree_search(&tree->state, start); 1306 while (node && start <= end) { 1307 state = rb_entry(node, struct extent_state, rb_node); 1308 1309 if (filled && state->start > start) { 1310 bitset = 0; 1311 break; 1312 } 1313 1314 if (state->start > end) 1315 break; 1316 1317 if (state->state & bits) { 1318 bitset = 1; 1319 if (!filled) 1320 break; 1321 } else if (filled) { 1322 bitset = 0; 1323 break; 1324 } 1325 start = state->end + 1; 1326 if (start > end) 1327 break; 1328 node = rb_next(node); 1329 } 1330 read_unlock_irq(&tree->lock); 1331 return bitset; 1332 } 1333 EXPORT_SYMBOL(test_range_bit); 1334 1335 /* 1336 * helper function to set a given page up to date if all the 1337 * extents in the tree for that page are up to date 1338 */ 1339 static int check_page_uptodate(struct extent_map_tree *tree, 1340 struct page *page) 1341 { 1342 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1343 u64 end = start + PAGE_CACHE_SIZE - 1; 1344 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1)) 1345 SetPageUptodate(page); 1346 return 0; 1347 } 1348 1349 /* 1350 * helper function to unlock a page if all the extents in the tree 1351 * for that page are unlocked 1352 */ 1353 static int check_page_locked(struct extent_map_tree *tree, 1354 struct page *page) 1355 { 1356 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1357 u64 end = start + PAGE_CACHE_SIZE - 1; 1358 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0)) 1359 unlock_page(page); 1360 return 0; 1361 } 1362 1363 /* 1364 * helper function to end page writeback if all the extents 1365 * in the tree for that page are done with writeback 1366 */ 1367 static int check_page_writeback(struct extent_map_tree *tree, 1368 struct page *page) 1369 { 1370 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1371 u64 end = start + PAGE_CACHE_SIZE - 1; 1372 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0)) 1373 end_page_writeback(page); 1374 return 0; 1375 } 1376 1377 /* lots and lots of room for performance fixes in the end_bio funcs */ 1378 1379 /* 1380 * after a writepage IO is done, we need to: 1381 * clear the uptodate bits on error 1382 * clear the writeback bits in the extent tree for this IO 1383 * end_page_writeback if the page has no more pending IO 1384 * 1385 * Scheduling is not allowed, so the extent state tree is expected 1386 * to have one and only one object corresponding to this IO. 1387 */ 1388 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1389 static void end_bio_extent_writepage(struct bio *bio, int err) 1390 #else 1391 static int end_bio_extent_writepage(struct bio *bio, 1392 unsigned int bytes_done, int err) 1393 #endif 1394 { 1395 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1396 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1397 struct extent_map_tree *tree = bio->bi_private; 1398 u64 start; 1399 u64 end; 1400 int whole_page; 1401 1402 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1403 if (bio->bi_size) 1404 return 1; 1405 #endif 1406 1407 do { 1408 struct page *page = bvec->bv_page; 1409 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1410 bvec->bv_offset; 1411 end = start + bvec->bv_len - 1; 1412 1413 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1414 whole_page = 1; 1415 else 1416 whole_page = 0; 1417 1418 if (--bvec >= bio->bi_io_vec) 1419 prefetchw(&bvec->bv_page->flags); 1420 1421 if (!uptodate) { 1422 clear_extent_uptodate(tree, start, end, GFP_ATOMIC); 1423 ClearPageUptodate(page); 1424 SetPageError(page); 1425 } 1426 clear_extent_writeback(tree, start, end, GFP_ATOMIC); 1427 1428 if (whole_page) 1429 end_page_writeback(page); 1430 else 1431 check_page_writeback(tree, page); 1432 if (tree->ops && tree->ops->writepage_end_io_hook) 1433 tree->ops->writepage_end_io_hook(page, start, end); 1434 } while (bvec >= bio->bi_io_vec); 1435 1436 bio_put(bio); 1437 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1438 return 0; 1439 #endif 1440 } 1441 1442 /* 1443 * after a readpage IO is done, we need to: 1444 * clear the uptodate bits on error 1445 * set the uptodate bits if things worked 1446 * set the page up to date if all extents in the tree are uptodate 1447 * clear the lock bit in the extent tree 1448 * unlock the page if there are no other extents locked for it 1449 * 1450 * Scheduling is not allowed, so the extent state tree is expected 1451 * to have one and only one object corresponding to this IO. 1452 */ 1453 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1454 static void end_bio_extent_readpage(struct bio *bio, int err) 1455 #else 1456 static int end_bio_extent_readpage(struct bio *bio, 1457 unsigned int bytes_done, int err) 1458 #endif 1459 { 1460 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1461 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1462 struct extent_map_tree *tree = bio->bi_private; 1463 u64 start; 1464 u64 end; 1465 int whole_page; 1466 int ret; 1467 1468 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1469 if (bio->bi_size) 1470 return 1; 1471 #endif 1472 1473 do { 1474 struct page *page = bvec->bv_page; 1475 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1476 bvec->bv_offset; 1477 end = start + bvec->bv_len - 1; 1478 1479 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1480 whole_page = 1; 1481 else 1482 whole_page = 0; 1483 1484 if (--bvec >= bio->bi_io_vec) 1485 prefetchw(&bvec->bv_page->flags); 1486 1487 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { 1488 ret = tree->ops->readpage_end_io_hook(page, start, end); 1489 if (ret) 1490 uptodate = 0; 1491 } 1492 if (uptodate) { 1493 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1494 if (whole_page) 1495 SetPageUptodate(page); 1496 else 1497 check_page_uptodate(tree, page); 1498 } else { 1499 ClearPageUptodate(page); 1500 SetPageError(page); 1501 } 1502 1503 unlock_extent(tree, start, end, GFP_ATOMIC); 1504 1505 if (whole_page) 1506 unlock_page(page); 1507 else 1508 check_page_locked(tree, page); 1509 } while (bvec >= bio->bi_io_vec); 1510 1511 bio_put(bio); 1512 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1513 return 0; 1514 #endif 1515 } 1516 1517 /* 1518 * IO done from prepare_write is pretty simple, we just unlock 1519 * the structs in the extent tree when done, and set the uptodate bits 1520 * as appropriate. 1521 */ 1522 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1523 static void end_bio_extent_preparewrite(struct bio *bio, int err) 1524 #else 1525 static int end_bio_extent_preparewrite(struct bio *bio, 1526 unsigned int bytes_done, int err) 1527 #endif 1528 { 1529 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1530 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1531 struct extent_map_tree *tree = bio->bi_private; 1532 u64 start; 1533 u64 end; 1534 1535 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1536 if (bio->bi_size) 1537 return 1; 1538 #endif 1539 1540 do { 1541 struct page *page = bvec->bv_page; 1542 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1543 bvec->bv_offset; 1544 end = start + bvec->bv_len - 1; 1545 1546 if (--bvec >= bio->bi_io_vec) 1547 prefetchw(&bvec->bv_page->flags); 1548 1549 if (uptodate) { 1550 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1551 } else { 1552 ClearPageUptodate(page); 1553 SetPageError(page); 1554 } 1555 1556 unlock_extent(tree, start, end, GFP_ATOMIC); 1557 1558 } while (bvec >= bio->bi_io_vec); 1559 1560 bio_put(bio); 1561 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1562 return 0; 1563 #endif 1564 } 1565 1566 static struct bio * 1567 extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, 1568 gfp_t gfp_flags) 1569 { 1570 struct bio *bio; 1571 1572 bio = bio_alloc(gfp_flags, nr_vecs); 1573 1574 if (bio == NULL && (current->flags & PF_MEMALLOC)) { 1575 while (!bio && (nr_vecs /= 2)) 1576 bio = bio_alloc(gfp_flags, nr_vecs); 1577 } 1578 1579 if (bio) { 1580 bio->bi_bdev = bdev; 1581 bio->bi_sector = first_sector; 1582 } 1583 return bio; 1584 } 1585 1586 static int submit_one_bio(int rw, struct bio *bio) 1587 { 1588 int ret = 0; 1589 bio_get(bio); 1590 submit_bio(rw, bio); 1591 if (bio_flagged(bio, BIO_EOPNOTSUPP)) 1592 ret = -EOPNOTSUPP; 1593 bio_put(bio); 1594 return ret; 1595 } 1596 1597 static int submit_extent_page(int rw, struct extent_map_tree *tree, 1598 struct page *page, sector_t sector, 1599 size_t size, unsigned long offset, 1600 struct block_device *bdev, 1601 struct bio **bio_ret, 1602 unsigned long max_pages, 1603 bio_end_io_t end_io_func) 1604 { 1605 int ret = 0; 1606 struct bio *bio; 1607 int nr; 1608 1609 if (bio_ret && *bio_ret) { 1610 bio = *bio_ret; 1611 if (bio->bi_sector + (bio->bi_size >> 9) != sector || 1612 bio_add_page(bio, page, size, offset) < size) { 1613 ret = submit_one_bio(rw, bio); 1614 bio = NULL; 1615 } else { 1616 return 0; 1617 } 1618 } 1619 nr = min_t(int, max_pages, bio_get_nr_vecs(bdev)); 1620 bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH); 1621 if (!bio) { 1622 printk("failed to allocate bio nr %d\n", nr); 1623 } 1624 bio_add_page(bio, page, size, offset); 1625 bio->bi_end_io = end_io_func; 1626 bio->bi_private = tree; 1627 if (bio_ret) { 1628 *bio_ret = bio; 1629 } else { 1630 ret = submit_one_bio(rw, bio); 1631 } 1632 1633 return ret; 1634 } 1635 1636 void set_page_extent_mapped(struct page *page) 1637 { 1638 if (!PagePrivate(page)) { 1639 SetPagePrivate(page); 1640 WARN_ON(!page->mapping->a_ops->invalidatepage); 1641 set_page_private(page, EXTENT_PAGE_PRIVATE); 1642 page_cache_get(page); 1643 } 1644 } 1645 1646 /* 1647 * basic readpage implementation. Locked extent state structs are inserted 1648 * into the tree that are removed when the IO is done (by the end_io 1649 * handlers) 1650 */ 1651 static int __extent_read_full_page(struct extent_map_tree *tree, 1652 struct page *page, 1653 get_extent_t *get_extent, 1654 struct bio **bio) 1655 { 1656 struct inode *inode = page->mapping->host; 1657 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1658 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1659 u64 end; 1660 u64 cur = start; 1661 u64 extent_offset; 1662 u64 last_byte = i_size_read(inode); 1663 u64 block_start; 1664 u64 cur_end; 1665 sector_t sector; 1666 struct extent_map *em; 1667 struct block_device *bdev; 1668 int ret; 1669 int nr = 0; 1670 size_t page_offset = 0; 1671 size_t iosize; 1672 size_t blocksize = inode->i_sb->s_blocksize; 1673 1674 set_page_extent_mapped(page); 1675 1676 end = page_end; 1677 lock_extent(tree, start, end, GFP_NOFS); 1678 1679 while (cur <= end) { 1680 if (cur >= last_byte) { 1681 iosize = PAGE_CACHE_SIZE - page_offset; 1682 zero_user_page(page, page_offset, iosize, KM_USER0); 1683 set_extent_uptodate(tree, cur, cur + iosize - 1, 1684 GFP_NOFS); 1685 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1686 break; 1687 } 1688 em = get_extent(inode, page, page_offset, cur, end, 0); 1689 if (IS_ERR(em) || !em) { 1690 SetPageError(page); 1691 unlock_extent(tree, cur, end, GFP_NOFS); 1692 break; 1693 } 1694 1695 extent_offset = cur - em->start; 1696 BUG_ON(em->end < cur); 1697 BUG_ON(end < cur); 1698 1699 iosize = min(em->end - cur, end - cur) + 1; 1700 cur_end = min(em->end, end); 1701 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1702 sector = (em->block_start + extent_offset) >> 9; 1703 bdev = em->bdev; 1704 block_start = em->block_start; 1705 free_extent_map(em); 1706 em = NULL; 1707 1708 /* we've found a hole, just zero and go on */ 1709 if (block_start == EXTENT_MAP_HOLE) { 1710 zero_user_page(page, page_offset, iosize, KM_USER0); 1711 set_extent_uptodate(tree, cur, cur + iosize - 1, 1712 GFP_NOFS); 1713 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1714 cur = cur + iosize; 1715 page_offset += iosize; 1716 continue; 1717 } 1718 /* the get_extent function already copied into the page */ 1719 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { 1720 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1721 cur = cur + iosize; 1722 page_offset += iosize; 1723 continue; 1724 } 1725 1726 ret = 0; 1727 if (tree->ops && tree->ops->readpage_io_hook) { 1728 ret = tree->ops->readpage_io_hook(page, cur, 1729 cur + iosize - 1); 1730 } 1731 if (!ret) { 1732 unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1; 1733 nr -= page->index; 1734 ret = submit_extent_page(READ, tree, page, 1735 sector, iosize, page_offset, 1736 bdev, bio, nr, 1737 end_bio_extent_readpage); 1738 } 1739 if (ret) 1740 SetPageError(page); 1741 cur = cur + iosize; 1742 page_offset += iosize; 1743 nr++; 1744 } 1745 if (!nr) { 1746 if (!PageError(page)) 1747 SetPageUptodate(page); 1748 unlock_page(page); 1749 } 1750 return 0; 1751 } 1752 1753 int extent_read_full_page(struct extent_map_tree *tree, struct page *page, 1754 get_extent_t *get_extent) 1755 { 1756 struct bio *bio = NULL; 1757 int ret; 1758 1759 ret = __extent_read_full_page(tree, page, get_extent, &bio); 1760 if (bio) 1761 submit_one_bio(READ, bio); 1762 return ret; 1763 } 1764 EXPORT_SYMBOL(extent_read_full_page); 1765 1766 /* 1767 * the writepage semantics are similar to regular writepage. extent 1768 * records are inserted to lock ranges in the tree, and as dirty areas 1769 * are found, they are marked writeback. Then the lock bits are removed 1770 * and the end_io handler clears the writeback ranges 1771 */ 1772 static int __extent_writepage(struct page *page, struct writeback_control *wbc, 1773 void *data) 1774 { 1775 struct inode *inode = page->mapping->host; 1776 struct extent_page_data *epd = data; 1777 struct extent_map_tree *tree = epd->tree; 1778 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1779 u64 delalloc_start; 1780 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1781 u64 end; 1782 u64 cur = start; 1783 u64 extent_offset; 1784 u64 last_byte = i_size_read(inode); 1785 u64 block_start; 1786 u64 iosize; 1787 sector_t sector; 1788 struct extent_map *em; 1789 struct block_device *bdev; 1790 int ret; 1791 int nr = 0; 1792 size_t page_offset = 0; 1793 size_t blocksize; 1794 loff_t i_size = i_size_read(inode); 1795 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; 1796 u64 nr_delalloc; 1797 u64 delalloc_end; 1798 1799 WARN_ON(!PageLocked(page)); 1800 if (page->index > end_index) { 1801 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1802 unlock_page(page); 1803 return 0; 1804 } 1805 1806 if (page->index == end_index) { 1807 size_t offset = i_size & (PAGE_CACHE_SIZE - 1); 1808 zero_user_page(page, offset, 1809 PAGE_CACHE_SIZE - offset, KM_USER0); 1810 } 1811 1812 set_page_extent_mapped(page); 1813 1814 delalloc_start = start; 1815 delalloc_end = 0; 1816 while(delalloc_end < page_end) { 1817 nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start, 1818 &delalloc_end, 1819 128 * 1024 * 1024); 1820 if (nr_delalloc <= 0) 1821 break; 1822 tree->ops->fill_delalloc(inode, delalloc_start, 1823 delalloc_end); 1824 clear_extent_bit(tree, delalloc_start, 1825 delalloc_end, 1826 EXTENT_LOCKED | EXTENT_DELALLOC, 1827 1, 0, GFP_NOFS); 1828 delalloc_start = delalloc_end + 1; 1829 } 1830 lock_extent(tree, start, page_end, GFP_NOFS); 1831 1832 end = page_end; 1833 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1834 printk("found delalloc bits after lock_extent\n"); 1835 } 1836 1837 if (last_byte <= start) { 1838 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1839 goto done; 1840 } 1841 1842 set_extent_uptodate(tree, start, page_end, GFP_NOFS); 1843 blocksize = inode->i_sb->s_blocksize; 1844 1845 while (cur <= end) { 1846 if (cur >= last_byte) { 1847 clear_extent_dirty(tree, cur, page_end, GFP_NOFS); 1848 break; 1849 } 1850 em = epd->get_extent(inode, page, page_offset, cur, end, 1); 1851 if (IS_ERR(em) || !em) { 1852 SetPageError(page); 1853 break; 1854 } 1855 1856 extent_offset = cur - em->start; 1857 BUG_ON(em->end < cur); 1858 BUG_ON(end < cur); 1859 iosize = min(em->end - cur, end - cur) + 1; 1860 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1861 sector = (em->block_start + extent_offset) >> 9; 1862 bdev = em->bdev; 1863 block_start = em->block_start; 1864 free_extent_map(em); 1865 em = NULL; 1866 1867 if (block_start == EXTENT_MAP_HOLE || 1868 block_start == EXTENT_MAP_INLINE) { 1869 clear_extent_dirty(tree, cur, 1870 cur + iosize - 1, GFP_NOFS); 1871 cur = cur + iosize; 1872 page_offset += iosize; 1873 continue; 1874 } 1875 1876 /* leave this out until we have a page_mkwrite call */ 1877 if (0 && !test_range_bit(tree, cur, cur + iosize - 1, 1878 EXTENT_DIRTY, 0)) { 1879 cur = cur + iosize; 1880 page_offset += iosize; 1881 continue; 1882 } 1883 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); 1884 if (tree->ops && tree->ops->writepage_io_hook) { 1885 ret = tree->ops->writepage_io_hook(page, cur, 1886 cur + iosize - 1); 1887 } else { 1888 ret = 0; 1889 } 1890 if (ret) 1891 SetPageError(page); 1892 else { 1893 unsigned long max_nr = end_index + 1; 1894 set_range_writeback(tree, cur, cur + iosize - 1); 1895 if (!PageWriteback(page)) { 1896 printk("warning page %lu not writeback, " 1897 "cur %llu end %llu\n", page->index, 1898 (unsigned long long)cur, 1899 (unsigned long long)end); 1900 } 1901 1902 ret = submit_extent_page(WRITE, tree, page, sector, 1903 iosize, page_offset, bdev, 1904 &epd->bio, max_nr, 1905 end_bio_extent_writepage); 1906 if (ret) 1907 SetPageError(page); 1908 } 1909 cur = cur + iosize; 1910 page_offset += iosize; 1911 nr++; 1912 } 1913 done: 1914 if (nr == 0) { 1915 /* make sure the mapping tag for page dirty gets cleared */ 1916 set_page_writeback(page); 1917 end_page_writeback(page); 1918 } 1919 unlock_extent(tree, start, page_end, GFP_NOFS); 1920 unlock_page(page); 1921 return 0; 1922 } 1923 1924 int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 1925 get_extent_t *get_extent, 1926 struct writeback_control *wbc) 1927 { 1928 int ret; 1929 struct address_space *mapping = page->mapping; 1930 struct extent_page_data epd = { 1931 .bio = NULL, 1932 .tree = tree, 1933 .get_extent = get_extent, 1934 }; 1935 struct writeback_control wbc_writepages = { 1936 .bdi = wbc->bdi, 1937 .sync_mode = WB_SYNC_NONE, 1938 .older_than_this = NULL, 1939 .nr_to_write = 64, 1940 .range_start = page_offset(page) + PAGE_CACHE_SIZE, 1941 .range_end = (loff_t)-1, 1942 }; 1943 1944 1945 ret = __extent_writepage(page, wbc, &epd); 1946 1947 write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd); 1948 if (epd.bio) 1949 submit_one_bio(WRITE, epd.bio); 1950 return ret; 1951 } 1952 EXPORT_SYMBOL(extent_write_full_page); 1953 1954 int extent_writepages(struct extent_map_tree *tree, 1955 struct address_space *mapping, 1956 get_extent_t *get_extent, 1957 struct writeback_control *wbc) 1958 { 1959 int ret; 1960 struct extent_page_data epd = { 1961 .bio = NULL, 1962 .tree = tree, 1963 .get_extent = get_extent, 1964 }; 1965 1966 ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd); 1967 if (epd.bio) 1968 submit_one_bio(WRITE, epd.bio); 1969 return ret; 1970 } 1971 EXPORT_SYMBOL(extent_writepages); 1972 1973 int extent_readpages(struct extent_map_tree *tree, 1974 struct address_space *mapping, 1975 struct list_head *pages, unsigned nr_pages, 1976 get_extent_t get_extent) 1977 { 1978 struct bio *bio = NULL; 1979 unsigned page_idx; 1980 struct pagevec pvec; 1981 1982 pagevec_init(&pvec, 0); 1983 for (page_idx = 0; page_idx < nr_pages; page_idx++) { 1984 struct page *page = list_entry(pages->prev, struct page, lru); 1985 1986 prefetchw(&page->flags); 1987 list_del(&page->lru); 1988 /* 1989 * what we want to do here is call add_to_page_cache_lru, 1990 * but that isn't exported, so we reproduce it here 1991 */ 1992 if (!add_to_page_cache(page, mapping, 1993 page->index, GFP_KERNEL)) { 1994 1995 /* open coding of lru_cache_add, also not exported */ 1996 page_cache_get(page); 1997 if (!pagevec_add(&pvec, page)) 1998 __pagevec_lru_add(&pvec); 1999 __extent_read_full_page(tree, page, get_extent, &bio); 2000 } 2001 page_cache_release(page); 2002 } 2003 if (pagevec_count(&pvec)) 2004 __pagevec_lru_add(&pvec); 2005 BUG_ON(!list_empty(pages)); 2006 if (bio) 2007 submit_one_bio(READ, bio); 2008 return 0; 2009 } 2010 EXPORT_SYMBOL(extent_readpages); 2011 2012 /* 2013 * basic invalidatepage code, this waits on any locked or writeback 2014 * ranges corresponding to the page, and then deletes any extent state 2015 * records from the tree 2016 */ 2017 int extent_invalidatepage(struct extent_map_tree *tree, 2018 struct page *page, unsigned long offset) 2019 { 2020 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT); 2021 u64 end = start + PAGE_CACHE_SIZE - 1; 2022 size_t blocksize = page->mapping->host->i_sb->s_blocksize; 2023 2024 start += (offset + blocksize -1) & ~(blocksize - 1); 2025 if (start > end) 2026 return 0; 2027 2028 lock_extent(tree, start, end, GFP_NOFS); 2029 wait_on_extent_writeback(tree, start, end); 2030 clear_extent_bit(tree, start, end, 2031 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, 2032 1, 1, GFP_NOFS); 2033 return 0; 2034 } 2035 EXPORT_SYMBOL(extent_invalidatepage); 2036 2037 /* 2038 * simple commit_write call, set_range_dirty is used to mark both 2039 * the pages and the extent records as dirty 2040 */ 2041 int extent_commit_write(struct extent_map_tree *tree, 2042 struct inode *inode, struct page *page, 2043 unsigned from, unsigned to) 2044 { 2045 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; 2046 2047 set_page_extent_mapped(page); 2048 set_page_dirty(page); 2049 2050 if (pos > inode->i_size) { 2051 i_size_write(inode, pos); 2052 mark_inode_dirty(inode); 2053 } 2054 return 0; 2055 } 2056 EXPORT_SYMBOL(extent_commit_write); 2057 2058 int extent_prepare_write(struct extent_map_tree *tree, 2059 struct inode *inode, struct page *page, 2060 unsigned from, unsigned to, get_extent_t *get_extent) 2061 { 2062 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 2063 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 2064 u64 block_start; 2065 u64 orig_block_start; 2066 u64 block_end; 2067 u64 cur_end; 2068 struct extent_map *em; 2069 unsigned blocksize = 1 << inode->i_blkbits; 2070 size_t page_offset = 0; 2071 size_t block_off_start; 2072 size_t block_off_end; 2073 int err = 0; 2074 int iocount = 0; 2075 int ret = 0; 2076 int isnew; 2077 2078 set_page_extent_mapped(page); 2079 2080 block_start = (page_start + from) & ~((u64)blocksize - 1); 2081 block_end = (page_start + to - 1) | (blocksize - 1); 2082 orig_block_start = block_start; 2083 2084 lock_extent(tree, page_start, page_end, GFP_NOFS); 2085 while(block_start <= block_end) { 2086 em = get_extent(inode, page, page_offset, block_start, 2087 block_end, 1); 2088 if (IS_ERR(em) || !em) { 2089 goto err; 2090 } 2091 cur_end = min(block_end, em->end); 2092 block_off_start = block_start & (PAGE_CACHE_SIZE - 1); 2093 block_off_end = block_off_start + blocksize; 2094 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); 2095 2096 if (!PageUptodate(page) && isnew && 2097 (block_off_end > to || block_off_start < from)) { 2098 void *kaddr; 2099 2100 kaddr = kmap_atomic(page, KM_USER0); 2101 if (block_off_end > to) 2102 memset(kaddr + to, 0, block_off_end - to); 2103 if (block_off_start < from) 2104 memset(kaddr + block_off_start, 0, 2105 from - block_off_start); 2106 flush_dcache_page(page); 2107 kunmap_atomic(kaddr, KM_USER0); 2108 } 2109 if (!isnew && !PageUptodate(page) && 2110 (block_off_end > to || block_off_start < from) && 2111 !test_range_bit(tree, block_start, cur_end, 2112 EXTENT_UPTODATE, 1)) { 2113 u64 sector; 2114 u64 extent_offset = block_start - em->start; 2115 size_t iosize; 2116 sector = (em->block_start + extent_offset) >> 9; 2117 iosize = (cur_end - block_start + blocksize - 1) & 2118 ~((u64)blocksize - 1); 2119 /* 2120 * we've already got the extent locked, but we 2121 * need to split the state such that our end_bio 2122 * handler can clear the lock. 2123 */ 2124 set_extent_bit(tree, block_start, 2125 block_start + iosize - 1, 2126 EXTENT_LOCKED, 0, NULL, GFP_NOFS); 2127 ret = submit_extent_page(READ, tree, page, 2128 sector, iosize, page_offset, em->bdev, 2129 NULL, 1, 2130 end_bio_extent_preparewrite); 2131 iocount++; 2132 block_start = block_start + iosize; 2133 } else { 2134 set_extent_uptodate(tree, block_start, cur_end, 2135 GFP_NOFS); 2136 unlock_extent(tree, block_start, cur_end, GFP_NOFS); 2137 block_start = cur_end + 1; 2138 } 2139 page_offset = block_start & (PAGE_CACHE_SIZE - 1); 2140 free_extent_map(em); 2141 } 2142 if (iocount) { 2143 wait_extent_bit(tree, orig_block_start, 2144 block_end, EXTENT_LOCKED); 2145 } 2146 check_page_uptodate(tree, page); 2147 err: 2148 /* FIXME, zero out newly allocated blocks on error */ 2149 return err; 2150 } 2151 EXPORT_SYMBOL(extent_prepare_write); 2152 2153 /* 2154 * a helper for releasepage. As long as there are no locked extents 2155 * in the range corresponding to the page, both state records and extent 2156 * map records are removed 2157 */ 2158 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) 2159 { 2160 struct extent_map *em; 2161 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 2162 u64 end = start + PAGE_CACHE_SIZE - 1; 2163 u64 orig_start = start; 2164 int ret = 1; 2165 2166 while (start <= end) { 2167 em = lookup_extent_mapping(tree, start, end); 2168 if (!em || IS_ERR(em)) 2169 break; 2170 if (!test_range_bit(tree, em->start, em->end, 2171 EXTENT_LOCKED, 0)) { 2172 remove_extent_mapping(tree, em); 2173 /* once for the rb tree */ 2174 free_extent_map(em); 2175 } 2176 start = em->end + 1; 2177 /* once for us */ 2178 free_extent_map(em); 2179 } 2180 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) 2181 ret = 0; 2182 else 2183 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, 2184 1, 1, GFP_NOFS); 2185 return ret; 2186 } 2187 EXPORT_SYMBOL(try_release_extent_mapping); 2188 2189 sector_t extent_bmap(struct address_space *mapping, sector_t iblock, 2190 get_extent_t *get_extent) 2191 { 2192 struct inode *inode = mapping->host; 2193 u64 start = iblock << inode->i_blkbits; 2194 u64 end = start + (1 << inode->i_blkbits) - 1; 2195 sector_t sector = 0; 2196 struct extent_map *em; 2197 2198 em = get_extent(inode, NULL, 0, start, end, 0); 2199 if (!em || IS_ERR(em)) 2200 return 0; 2201 2202 if (em->block_start == EXTENT_MAP_INLINE || 2203 em->block_start == EXTENT_MAP_HOLE) 2204 goto out; 2205 2206 sector = (em->block_start + start - em->start) >> inode->i_blkbits; 2207 out: 2208 free_extent_map(em); 2209 return sector; 2210 } 2211 2212 static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb) 2213 { 2214 if (list_empty(&eb->lru)) { 2215 extent_buffer_get(eb); 2216 list_add(&eb->lru, &tree->buffer_lru); 2217 tree->lru_size++; 2218 if (tree->lru_size >= BUFFER_LRU_MAX) { 2219 struct extent_buffer *rm; 2220 rm = list_entry(tree->buffer_lru.prev, 2221 struct extent_buffer, lru); 2222 tree->lru_size--; 2223 list_del_init(&rm->lru); 2224 free_extent_buffer(rm); 2225 } 2226 } else 2227 list_move(&eb->lru, &tree->buffer_lru); 2228 return 0; 2229 } 2230 static struct extent_buffer *find_lru(struct extent_map_tree *tree, 2231 u64 start, unsigned long len) 2232 { 2233 struct list_head *lru = &tree->buffer_lru; 2234 struct list_head *cur = lru->next; 2235 struct extent_buffer *eb; 2236 2237 if (list_empty(lru)) 2238 return NULL; 2239 2240 do { 2241 eb = list_entry(cur, struct extent_buffer, lru); 2242 if (eb->start == start && eb->len == len) { 2243 extent_buffer_get(eb); 2244 return eb; 2245 } 2246 cur = cur->next; 2247 } while (cur != lru); 2248 return NULL; 2249 } 2250 2251 static inline unsigned long num_extent_pages(u64 start, u64 len) 2252 { 2253 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - 2254 (start >> PAGE_CACHE_SHIFT); 2255 } 2256 2257 static inline struct page *extent_buffer_page(struct extent_buffer *eb, 2258 unsigned long i) 2259 { 2260 struct page *p; 2261 struct address_space *mapping; 2262 2263 if (i == 0) 2264 return eb->first_page; 2265 i += eb->start >> PAGE_CACHE_SHIFT; 2266 mapping = eb->first_page->mapping; 2267 read_lock_irq(&mapping->tree_lock); 2268 p = radix_tree_lookup(&mapping->page_tree, i); 2269 read_unlock_irq(&mapping->tree_lock); 2270 return p; 2271 } 2272 2273 static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, 2274 u64 start, 2275 unsigned long len, 2276 gfp_t mask) 2277 { 2278 struct extent_buffer *eb = NULL; 2279 2280 spin_lock(&tree->lru_lock); 2281 eb = find_lru(tree, start, len); 2282 spin_unlock(&tree->lru_lock); 2283 if (eb) { 2284 return eb; 2285 } 2286 2287 eb = kmem_cache_zalloc(extent_buffer_cache, mask); 2288 INIT_LIST_HEAD(&eb->lru); 2289 eb->start = start; 2290 eb->len = len; 2291 atomic_set(&eb->refs, 1); 2292 2293 return eb; 2294 } 2295 2296 static void __free_extent_buffer(struct extent_buffer *eb) 2297 { 2298 kmem_cache_free(extent_buffer_cache, eb); 2299 } 2300 2301 struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 2302 u64 start, unsigned long len, 2303 struct page *page0, 2304 gfp_t mask) 2305 { 2306 unsigned long num_pages = num_extent_pages(start, len); 2307 unsigned long i; 2308 unsigned long index = start >> PAGE_CACHE_SHIFT; 2309 struct extent_buffer *eb; 2310 struct page *p; 2311 struct address_space *mapping = tree->mapping; 2312 int uptodate = 1; 2313 2314 eb = __alloc_extent_buffer(tree, start, len, mask); 2315 if (!eb || IS_ERR(eb)) 2316 return NULL; 2317 2318 if (eb->flags & EXTENT_BUFFER_FILLED) 2319 goto lru_add; 2320 2321 if (page0) { 2322 eb->first_page = page0; 2323 i = 1; 2324 index++; 2325 page_cache_get(page0); 2326 mark_page_accessed(page0); 2327 set_page_extent_mapped(page0); 2328 WARN_ON(!PageUptodate(page0)); 2329 set_page_private(page0, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2330 len << 2); 2331 } else { 2332 i = 0; 2333 } 2334 for (; i < num_pages; i++, index++) { 2335 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM); 2336 if (!p) { 2337 WARN_ON(1); 2338 goto fail; 2339 } 2340 set_page_extent_mapped(p); 2341 mark_page_accessed(p); 2342 if (i == 0) { 2343 eb->first_page = p; 2344 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2345 len << 2); 2346 } else { 2347 set_page_private(p, EXTENT_PAGE_PRIVATE); 2348 } 2349 if (!PageUptodate(p)) 2350 uptodate = 0; 2351 unlock_page(p); 2352 } 2353 if (uptodate) 2354 eb->flags |= EXTENT_UPTODATE; 2355 eb->flags |= EXTENT_BUFFER_FILLED; 2356 2357 lru_add: 2358 spin_lock(&tree->lru_lock); 2359 add_lru(tree, eb); 2360 spin_unlock(&tree->lru_lock); 2361 return eb; 2362 2363 fail: 2364 spin_lock(&tree->lru_lock); 2365 list_del_init(&eb->lru); 2366 spin_unlock(&tree->lru_lock); 2367 if (!atomic_dec_and_test(&eb->refs)) 2368 return NULL; 2369 for (index = 1; index < i; index++) { 2370 page_cache_release(extent_buffer_page(eb, index)); 2371 } 2372 if (i > 0) 2373 page_cache_release(extent_buffer_page(eb, 0)); 2374 __free_extent_buffer(eb); 2375 return NULL; 2376 } 2377 EXPORT_SYMBOL(alloc_extent_buffer); 2378 2379 struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 2380 u64 start, unsigned long len, 2381 gfp_t mask) 2382 { 2383 unsigned long num_pages = num_extent_pages(start, len); 2384 unsigned long i; 2385 unsigned long index = start >> PAGE_CACHE_SHIFT; 2386 struct extent_buffer *eb; 2387 struct page *p; 2388 struct address_space *mapping = tree->mapping; 2389 int uptodate = 1; 2390 2391 eb = __alloc_extent_buffer(tree, start, len, mask); 2392 if (!eb || IS_ERR(eb)) 2393 return NULL; 2394 2395 if (eb->flags & EXTENT_BUFFER_FILLED) 2396 goto lru_add; 2397 2398 for (i = 0; i < num_pages; i++, index++) { 2399 p = find_lock_page(mapping, index); 2400 if (!p) { 2401 goto fail; 2402 } 2403 set_page_extent_mapped(p); 2404 mark_page_accessed(p); 2405 2406 if (i == 0) { 2407 eb->first_page = p; 2408 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2409 len << 2); 2410 } else { 2411 set_page_private(p, EXTENT_PAGE_PRIVATE); 2412 } 2413 2414 if (!PageUptodate(p)) 2415 uptodate = 0; 2416 unlock_page(p); 2417 } 2418 if (uptodate) 2419 eb->flags |= EXTENT_UPTODATE; 2420 eb->flags |= EXTENT_BUFFER_FILLED; 2421 2422 lru_add: 2423 spin_lock(&tree->lru_lock); 2424 add_lru(tree, eb); 2425 spin_unlock(&tree->lru_lock); 2426 return eb; 2427 fail: 2428 spin_lock(&tree->lru_lock); 2429 list_del_init(&eb->lru); 2430 spin_unlock(&tree->lru_lock); 2431 if (!atomic_dec_and_test(&eb->refs)) 2432 return NULL; 2433 for (index = 1; index < i; index++) { 2434 page_cache_release(extent_buffer_page(eb, index)); 2435 } 2436 if (i > 0) 2437 page_cache_release(extent_buffer_page(eb, 0)); 2438 __free_extent_buffer(eb); 2439 return NULL; 2440 } 2441 EXPORT_SYMBOL(find_extent_buffer); 2442 2443 void free_extent_buffer(struct extent_buffer *eb) 2444 { 2445 unsigned long i; 2446 unsigned long num_pages; 2447 2448 if (!eb) 2449 return; 2450 2451 if (!atomic_dec_and_test(&eb->refs)) 2452 return; 2453 2454 WARN_ON(!list_empty(&eb->lru)); 2455 num_pages = num_extent_pages(eb->start, eb->len); 2456 2457 for (i = 1; i < num_pages; i++) { 2458 page_cache_release(extent_buffer_page(eb, i)); 2459 } 2460 page_cache_release(extent_buffer_page(eb, 0)); 2461 __free_extent_buffer(eb); 2462 } 2463 EXPORT_SYMBOL(free_extent_buffer); 2464 2465 int clear_extent_buffer_dirty(struct extent_map_tree *tree, 2466 struct extent_buffer *eb) 2467 { 2468 int set; 2469 unsigned long i; 2470 unsigned long num_pages; 2471 struct page *page; 2472 2473 u64 start = eb->start; 2474 u64 end = start + eb->len - 1; 2475 2476 set = clear_extent_dirty(tree, start, end, GFP_NOFS); 2477 num_pages = num_extent_pages(eb->start, eb->len); 2478 2479 for (i = 0; i < num_pages; i++) { 2480 page = extent_buffer_page(eb, i); 2481 lock_page(page); 2482 /* 2483 * if we're on the last page or the first page and the 2484 * block isn't aligned on a page boundary, do extra checks 2485 * to make sure we don't clean page that is partially dirty 2486 */ 2487 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2488 ((i == num_pages - 1) && 2489 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2490 start = (u64)page->index << PAGE_CACHE_SHIFT; 2491 end = start + PAGE_CACHE_SIZE - 1; 2492 if (test_range_bit(tree, start, end, 2493 EXTENT_DIRTY, 0)) { 2494 unlock_page(page); 2495 continue; 2496 } 2497 } 2498 clear_page_dirty_for_io(page); 2499 write_lock_irq(&page->mapping->tree_lock); 2500 if (!PageDirty(page)) { 2501 radix_tree_tag_clear(&page->mapping->page_tree, 2502 page_index(page), 2503 PAGECACHE_TAG_DIRTY); 2504 } 2505 write_unlock_irq(&page->mapping->tree_lock); 2506 unlock_page(page); 2507 } 2508 return 0; 2509 } 2510 EXPORT_SYMBOL(clear_extent_buffer_dirty); 2511 2512 int wait_on_extent_buffer_writeback(struct extent_map_tree *tree, 2513 struct extent_buffer *eb) 2514 { 2515 return wait_on_extent_writeback(tree, eb->start, 2516 eb->start + eb->len - 1); 2517 } 2518 EXPORT_SYMBOL(wait_on_extent_buffer_writeback); 2519 2520 int set_extent_buffer_dirty(struct extent_map_tree *tree, 2521 struct extent_buffer *eb) 2522 { 2523 unsigned long i; 2524 unsigned long num_pages; 2525 2526 num_pages = num_extent_pages(eb->start, eb->len); 2527 for (i = 0; i < num_pages; i++) { 2528 struct page *page = extent_buffer_page(eb, i); 2529 /* writepage may need to do something special for the 2530 * first page, we have to make sure page->private is 2531 * properly set. releasepage may drop page->private 2532 * on us if the page isn't already dirty. 2533 */ 2534 if (i == 0) { 2535 lock_page(page); 2536 set_page_private(page, 2537 EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2538 eb->len << 2); 2539 } 2540 __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); 2541 if (i == 0) 2542 unlock_page(page); 2543 } 2544 return set_extent_dirty(tree, eb->start, 2545 eb->start + eb->len - 1, GFP_NOFS); 2546 } 2547 EXPORT_SYMBOL(set_extent_buffer_dirty); 2548 2549 int set_extent_buffer_uptodate(struct extent_map_tree *tree, 2550 struct extent_buffer *eb) 2551 { 2552 unsigned long i; 2553 struct page *page; 2554 unsigned long num_pages; 2555 2556 num_pages = num_extent_pages(eb->start, eb->len); 2557 2558 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, 2559 GFP_NOFS); 2560 for (i = 0; i < num_pages; i++) { 2561 page = extent_buffer_page(eb, i); 2562 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2563 ((i == num_pages - 1) && 2564 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2565 check_page_uptodate(tree, page); 2566 continue; 2567 } 2568 SetPageUptodate(page); 2569 } 2570 return 0; 2571 } 2572 EXPORT_SYMBOL(set_extent_buffer_uptodate); 2573 2574 int extent_buffer_uptodate(struct extent_map_tree *tree, 2575 struct extent_buffer *eb) 2576 { 2577 if (eb->flags & EXTENT_UPTODATE) 2578 return 1; 2579 return test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2580 EXTENT_UPTODATE, 1); 2581 } 2582 EXPORT_SYMBOL(extent_buffer_uptodate); 2583 2584 int read_extent_buffer_pages(struct extent_map_tree *tree, 2585 struct extent_buffer *eb, 2586 u64 start, 2587 int wait) 2588 { 2589 unsigned long i; 2590 unsigned long start_i; 2591 struct page *page; 2592 int err; 2593 int ret = 0; 2594 unsigned long num_pages; 2595 2596 if (eb->flags & EXTENT_UPTODATE) 2597 return 0; 2598 2599 if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2600 EXTENT_UPTODATE, 1)) { 2601 return 0; 2602 } 2603 2604 if (start) { 2605 WARN_ON(start < eb->start); 2606 start_i = (start >> PAGE_CACHE_SHIFT) - 2607 (eb->start >> PAGE_CACHE_SHIFT); 2608 } else { 2609 start_i = 0; 2610 } 2611 2612 num_pages = num_extent_pages(eb->start, eb->len); 2613 for (i = start_i; i < num_pages; i++) { 2614 page = extent_buffer_page(eb, i); 2615 if (PageUptodate(page)) { 2616 continue; 2617 } 2618 if (!wait) { 2619 if (TestSetPageLocked(page)) { 2620 continue; 2621 } 2622 } else { 2623 lock_page(page); 2624 } 2625 if (!PageUptodate(page)) { 2626 err = page->mapping->a_ops->readpage(NULL, page); 2627 if (err) { 2628 ret = err; 2629 } 2630 } else { 2631 unlock_page(page); 2632 } 2633 } 2634 2635 if (ret || !wait) { 2636 return ret; 2637 } 2638 2639 for (i = start_i; i < num_pages; i++) { 2640 page = extent_buffer_page(eb, i); 2641 wait_on_page_locked(page); 2642 if (!PageUptodate(page)) { 2643 ret = -EIO; 2644 } 2645 } 2646 if (!ret) 2647 eb->flags |= EXTENT_UPTODATE; 2648 return ret; 2649 } 2650 EXPORT_SYMBOL(read_extent_buffer_pages); 2651 2652 void read_extent_buffer(struct extent_buffer *eb, void *dstv, 2653 unsigned long start, 2654 unsigned long len) 2655 { 2656 size_t cur; 2657 size_t offset; 2658 struct page *page; 2659 char *kaddr; 2660 char *dst = (char *)dstv; 2661 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2662 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2663 unsigned long num_pages = num_extent_pages(eb->start, eb->len); 2664 2665 WARN_ON(start > eb->len); 2666 WARN_ON(start + len > eb->start + eb->len); 2667 2668 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2669 2670 while(len > 0) { 2671 page = extent_buffer_page(eb, i); 2672 if (!PageUptodate(page)) { 2673 printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); 2674 WARN_ON(1); 2675 } 2676 WARN_ON(!PageUptodate(page)); 2677 2678 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2679 kaddr = kmap_atomic(page, KM_USER1); 2680 memcpy(dst, kaddr + offset, cur); 2681 kunmap_atomic(kaddr, KM_USER1); 2682 2683 dst += cur; 2684 len -= cur; 2685 offset = 0; 2686 i++; 2687 } 2688 } 2689 EXPORT_SYMBOL(read_extent_buffer); 2690 2691 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, 2692 unsigned long min_len, char **token, char **map, 2693 unsigned long *map_start, 2694 unsigned long *map_len, int km) 2695 { 2696 size_t offset = start & (PAGE_CACHE_SIZE - 1); 2697 char *kaddr; 2698 struct page *p; 2699 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2700 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2701 unsigned long end_i = (start_offset + start + min_len - 1) >> 2702 PAGE_CACHE_SHIFT; 2703 2704 if (i != end_i) 2705 return -EINVAL; 2706 2707 if (i == 0) { 2708 offset = start_offset; 2709 *map_start = 0; 2710 } else { 2711 offset = 0; 2712 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset; 2713 } 2714 if (start + min_len > eb->len) { 2715 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); 2716 WARN_ON(1); 2717 } 2718 2719 p = extent_buffer_page(eb, i); 2720 WARN_ON(!PageUptodate(p)); 2721 kaddr = kmap_atomic(p, km); 2722 *token = kaddr; 2723 *map = kaddr + offset; 2724 *map_len = PAGE_CACHE_SIZE - offset; 2725 return 0; 2726 } 2727 EXPORT_SYMBOL(map_private_extent_buffer); 2728 2729 int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 2730 unsigned long min_len, 2731 char **token, char **map, 2732 unsigned long *map_start, 2733 unsigned long *map_len, int km) 2734 { 2735 int err; 2736 int save = 0; 2737 if (eb->map_token) { 2738 unmap_extent_buffer(eb, eb->map_token, km); 2739 eb->map_token = NULL; 2740 save = 1; 2741 } 2742 err = map_private_extent_buffer(eb, start, min_len, token, map, 2743 map_start, map_len, km); 2744 if (!err && save) { 2745 eb->map_token = *token; 2746 eb->kaddr = *map; 2747 eb->map_start = *map_start; 2748 eb->map_len = *map_len; 2749 } 2750 return err; 2751 } 2752 EXPORT_SYMBOL(map_extent_buffer); 2753 2754 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) 2755 { 2756 kunmap_atomic(token, km); 2757 } 2758 EXPORT_SYMBOL(unmap_extent_buffer); 2759 2760 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 2761 unsigned long start, 2762 unsigned long len) 2763 { 2764 size_t cur; 2765 size_t offset; 2766 struct page *page; 2767 char *kaddr; 2768 char *ptr = (char *)ptrv; 2769 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2770 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2771 int ret = 0; 2772 2773 WARN_ON(start > eb->len); 2774 WARN_ON(start + len > eb->start + eb->len); 2775 2776 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2777 2778 while(len > 0) { 2779 page = extent_buffer_page(eb, i); 2780 WARN_ON(!PageUptodate(page)); 2781 2782 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2783 2784 kaddr = kmap_atomic(page, KM_USER0); 2785 ret = memcmp(ptr, kaddr + offset, cur); 2786 kunmap_atomic(kaddr, KM_USER0); 2787 if (ret) 2788 break; 2789 2790 ptr += cur; 2791 len -= cur; 2792 offset = 0; 2793 i++; 2794 } 2795 return ret; 2796 } 2797 EXPORT_SYMBOL(memcmp_extent_buffer); 2798 2799 void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 2800 unsigned long start, unsigned long len) 2801 { 2802 size_t cur; 2803 size_t offset; 2804 struct page *page; 2805 char *kaddr; 2806 char *src = (char *)srcv; 2807 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2808 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2809 2810 WARN_ON(start > eb->len); 2811 WARN_ON(start + len > eb->start + eb->len); 2812 2813 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2814 2815 while(len > 0) { 2816 page = extent_buffer_page(eb, i); 2817 WARN_ON(!PageUptodate(page)); 2818 2819 cur = min(len, PAGE_CACHE_SIZE - offset); 2820 kaddr = kmap_atomic(page, KM_USER1); 2821 memcpy(kaddr + offset, src, cur); 2822 kunmap_atomic(kaddr, KM_USER1); 2823 2824 src += cur; 2825 len -= cur; 2826 offset = 0; 2827 i++; 2828 } 2829 } 2830 EXPORT_SYMBOL(write_extent_buffer); 2831 2832 void memset_extent_buffer(struct extent_buffer *eb, char c, 2833 unsigned long start, unsigned long len) 2834 { 2835 size_t cur; 2836 size_t offset; 2837 struct page *page; 2838 char *kaddr; 2839 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2840 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2841 2842 WARN_ON(start > eb->len); 2843 WARN_ON(start + len > eb->start + eb->len); 2844 2845 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2846 2847 while(len > 0) { 2848 page = extent_buffer_page(eb, i); 2849 WARN_ON(!PageUptodate(page)); 2850 2851 cur = min(len, PAGE_CACHE_SIZE - offset); 2852 kaddr = kmap_atomic(page, KM_USER0); 2853 memset(kaddr + offset, c, cur); 2854 kunmap_atomic(kaddr, KM_USER0); 2855 2856 len -= cur; 2857 offset = 0; 2858 i++; 2859 } 2860 } 2861 EXPORT_SYMBOL(memset_extent_buffer); 2862 2863 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 2864 unsigned long dst_offset, unsigned long src_offset, 2865 unsigned long len) 2866 { 2867 u64 dst_len = dst->len; 2868 size_t cur; 2869 size_t offset; 2870 struct page *page; 2871 char *kaddr; 2872 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2873 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2874 2875 WARN_ON(src->len != dst_len); 2876 2877 offset = (start_offset + dst_offset) & 2878 ((unsigned long)PAGE_CACHE_SIZE - 1); 2879 2880 while(len > 0) { 2881 page = extent_buffer_page(dst, i); 2882 WARN_ON(!PageUptodate(page)); 2883 2884 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset)); 2885 2886 kaddr = kmap_atomic(page, KM_USER0); 2887 read_extent_buffer(src, kaddr + offset, src_offset, cur); 2888 kunmap_atomic(kaddr, KM_USER0); 2889 2890 src_offset += cur; 2891 len -= cur; 2892 offset = 0; 2893 i++; 2894 } 2895 } 2896 EXPORT_SYMBOL(copy_extent_buffer); 2897 2898 static void move_pages(struct page *dst_page, struct page *src_page, 2899 unsigned long dst_off, unsigned long src_off, 2900 unsigned long len) 2901 { 2902 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2903 if (dst_page == src_page) { 2904 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len); 2905 } else { 2906 char *src_kaddr = kmap_atomic(src_page, KM_USER1); 2907 char *p = dst_kaddr + dst_off + len; 2908 char *s = src_kaddr + src_off + len; 2909 2910 while (len--) 2911 *--p = *--s; 2912 2913 kunmap_atomic(src_kaddr, KM_USER1); 2914 } 2915 kunmap_atomic(dst_kaddr, KM_USER0); 2916 } 2917 2918 static void copy_pages(struct page *dst_page, struct page *src_page, 2919 unsigned long dst_off, unsigned long src_off, 2920 unsigned long len) 2921 { 2922 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2923 char *src_kaddr; 2924 2925 if (dst_page != src_page) 2926 src_kaddr = kmap_atomic(src_page, KM_USER1); 2927 else 2928 src_kaddr = dst_kaddr; 2929 2930 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); 2931 kunmap_atomic(dst_kaddr, KM_USER0); 2932 if (dst_page != src_page) 2933 kunmap_atomic(src_kaddr, KM_USER1); 2934 } 2935 2936 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2937 unsigned long src_offset, unsigned long len) 2938 { 2939 size_t cur; 2940 size_t dst_off_in_page; 2941 size_t src_off_in_page; 2942 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2943 unsigned long dst_i; 2944 unsigned long src_i; 2945 2946 if (src_offset + len > dst->len) { 2947 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2948 src_offset, len, dst->len); 2949 BUG_ON(1); 2950 } 2951 if (dst_offset + len > dst->len) { 2952 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2953 dst_offset, len, dst->len); 2954 BUG_ON(1); 2955 } 2956 2957 while(len > 0) { 2958 dst_off_in_page = (start_offset + dst_offset) & 2959 ((unsigned long)PAGE_CACHE_SIZE - 1); 2960 src_off_in_page = (start_offset + src_offset) & 2961 ((unsigned long)PAGE_CACHE_SIZE - 1); 2962 2963 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2964 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT; 2965 2966 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - 2967 src_off_in_page)); 2968 cur = min_t(unsigned long, cur, 2969 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page)); 2970 2971 copy_pages(extent_buffer_page(dst, dst_i), 2972 extent_buffer_page(dst, src_i), 2973 dst_off_in_page, src_off_in_page, cur); 2974 2975 src_offset += cur; 2976 dst_offset += cur; 2977 len -= cur; 2978 } 2979 } 2980 EXPORT_SYMBOL(memcpy_extent_buffer); 2981 2982 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2983 unsigned long src_offset, unsigned long len) 2984 { 2985 size_t cur; 2986 size_t dst_off_in_page; 2987 size_t src_off_in_page; 2988 unsigned long dst_end = dst_offset + len - 1; 2989 unsigned long src_end = src_offset + len - 1; 2990 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2991 unsigned long dst_i; 2992 unsigned long src_i; 2993 2994 if (src_offset + len > dst->len) { 2995 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2996 src_offset, len, dst->len); 2997 BUG_ON(1); 2998 } 2999 if (dst_offset + len > dst->len) { 3000 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 3001 dst_offset, len, dst->len); 3002 BUG_ON(1); 3003 } 3004 if (dst_offset < src_offset) { 3005 memcpy_extent_buffer(dst, dst_offset, src_offset, len); 3006 return; 3007 } 3008 while(len > 0) { 3009 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT; 3010 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT; 3011 3012 dst_off_in_page = (start_offset + dst_end) & 3013 ((unsigned long)PAGE_CACHE_SIZE - 1); 3014 src_off_in_page = (start_offset + src_end) & 3015 ((unsigned long)PAGE_CACHE_SIZE - 1); 3016 3017 cur = min_t(unsigned long, len, src_off_in_page + 1); 3018 cur = min(cur, dst_off_in_page + 1); 3019 move_pages(extent_buffer_page(dst, dst_i), 3020 extent_buffer_page(dst, src_i), 3021 dst_off_in_page - cur + 1, 3022 src_off_in_page - cur + 1, cur); 3023 3024 dst_end -= cur; 3025 src_end -= cur; 3026 len -= cur; 3027 } 3028 } 3029 EXPORT_SYMBOL(memmove_extent_buffer); 3030