1 #include <linux/bitops.h> 2 #include <linux/slab.h> 3 #include <linux/bio.h> 4 #include <linux/mm.h> 5 #include <linux/gfp.h> 6 #include <linux/pagemap.h> 7 #include <linux/page-flags.h> 8 #include <linux/module.h> 9 #include <linux/spinlock.h> 10 #include <linux/blkdev.h> 11 #include <linux/swap.h> 12 #include <linux/version.h> 13 #include "extent_map.h" 14 15 /* temporary define until extent_map moves out of btrfs */ 16 struct kmem_cache *btrfs_cache_create(const char *name, size_t size, 17 unsigned long extra_flags, 18 void (*ctor)(void *, struct kmem_cache *, 19 unsigned long)); 20 21 static struct kmem_cache *extent_map_cache; 22 static struct kmem_cache *extent_state_cache; 23 static struct kmem_cache *extent_buffer_cache; 24 25 static LIST_HEAD(buffers); 26 static LIST_HEAD(states); 27 28 static spinlock_t state_lock = SPIN_LOCK_UNLOCKED; 29 #define BUFFER_LRU_MAX 64 30 31 struct tree_entry { 32 u64 start; 33 u64 end; 34 int in_tree; 35 struct rb_node rb_node; 36 }; 37 38 void __init extent_map_init(void) 39 { 40 extent_map_cache = btrfs_cache_create("extent_map", 41 sizeof(struct extent_map), 0, 42 NULL); 43 extent_state_cache = btrfs_cache_create("extent_state", 44 sizeof(struct extent_state), 0, 45 NULL); 46 extent_buffer_cache = btrfs_cache_create("extent_buffers", 47 sizeof(struct extent_buffer), 0, 48 NULL); 49 } 50 51 void __exit extent_map_exit(void) 52 { 53 struct extent_state *state; 54 55 while (!list_empty(&states)) { 56 state = list_entry(states.next, struct extent_state, list); 57 printk("state leak: start %Lu end %Lu state %lu in tree %d refs %d\n", state->start, state->end, state->state, state->in_tree, atomic_read(&state->refs)); 58 list_del(&state->list); 59 kmem_cache_free(extent_state_cache, state); 60 61 } 62 63 if (extent_map_cache) 64 kmem_cache_destroy(extent_map_cache); 65 if (extent_state_cache) 66 kmem_cache_destroy(extent_state_cache); 67 if (extent_buffer_cache) 68 kmem_cache_destroy(extent_buffer_cache); 69 } 70 71 void extent_map_tree_init(struct extent_map_tree *tree, 72 struct address_space *mapping, gfp_t mask) 73 { 74 tree->map.rb_node = NULL; 75 tree->state.rb_node = NULL; 76 tree->ops = NULL; 77 rwlock_init(&tree->lock); 78 spin_lock_init(&tree->lru_lock); 79 tree->mapping = mapping; 80 INIT_LIST_HEAD(&tree->buffer_lru); 81 tree->lru_size = 0; 82 } 83 EXPORT_SYMBOL(extent_map_tree_init); 84 85 void extent_map_tree_empty_lru(struct extent_map_tree *tree) 86 { 87 struct extent_buffer *eb; 88 while(!list_empty(&tree->buffer_lru)) { 89 eb = list_entry(tree->buffer_lru.next, struct extent_buffer, 90 lru); 91 list_del(&eb->lru); 92 free_extent_buffer(eb); 93 } 94 } 95 EXPORT_SYMBOL(extent_map_tree_empty_lru); 96 97 struct extent_map *alloc_extent_map(gfp_t mask) 98 { 99 struct extent_map *em; 100 em = kmem_cache_alloc(extent_map_cache, mask); 101 if (!em || IS_ERR(em)) 102 return em; 103 em->in_tree = 0; 104 atomic_set(&em->refs, 1); 105 return em; 106 } 107 EXPORT_SYMBOL(alloc_extent_map); 108 109 void free_extent_map(struct extent_map *em) 110 { 111 if (!em) 112 return; 113 if (atomic_dec_and_test(&em->refs)) { 114 WARN_ON(em->in_tree); 115 kmem_cache_free(extent_map_cache, em); 116 } 117 } 118 EXPORT_SYMBOL(free_extent_map); 119 120 121 struct extent_state *alloc_extent_state(gfp_t mask) 122 { 123 struct extent_state *state; 124 unsigned long flags; 125 126 state = kmem_cache_alloc(extent_state_cache, mask); 127 if (!state || IS_ERR(state)) 128 return state; 129 state->state = 0; 130 state->in_tree = 0; 131 state->private = 0; 132 133 spin_lock_irqsave(&state_lock, flags); 134 list_add(&state->list, &states); 135 spin_unlock_irqrestore(&state_lock, flags); 136 137 atomic_set(&state->refs, 1); 138 init_waitqueue_head(&state->wq); 139 return state; 140 } 141 EXPORT_SYMBOL(alloc_extent_state); 142 143 void free_extent_state(struct extent_state *state) 144 { 145 unsigned long flags; 146 if (!state) 147 return; 148 if (atomic_dec_and_test(&state->refs)) { 149 WARN_ON(state->in_tree); 150 spin_lock_irqsave(&state_lock, flags); 151 list_del(&state->list); 152 spin_unlock_irqrestore(&state_lock, flags); 153 kmem_cache_free(extent_state_cache, state); 154 } 155 } 156 EXPORT_SYMBOL(free_extent_state); 157 158 static struct rb_node *tree_insert(struct rb_root *root, u64 offset, 159 struct rb_node *node) 160 { 161 struct rb_node ** p = &root->rb_node; 162 struct rb_node * parent = NULL; 163 struct tree_entry *entry; 164 165 while(*p) { 166 parent = *p; 167 entry = rb_entry(parent, struct tree_entry, rb_node); 168 169 if (offset < entry->start) 170 p = &(*p)->rb_left; 171 else if (offset > entry->end) 172 p = &(*p)->rb_right; 173 else 174 return parent; 175 } 176 177 entry = rb_entry(node, struct tree_entry, rb_node); 178 entry->in_tree = 1; 179 rb_link_node(node, parent, p); 180 rb_insert_color(node, root); 181 return NULL; 182 } 183 184 static struct rb_node *__tree_search(struct rb_root *root, u64 offset, 185 struct rb_node **prev_ret) 186 { 187 struct rb_node * n = root->rb_node; 188 struct rb_node *prev = NULL; 189 struct tree_entry *entry; 190 struct tree_entry *prev_entry = NULL; 191 192 while(n) { 193 entry = rb_entry(n, struct tree_entry, rb_node); 194 prev = n; 195 prev_entry = entry; 196 197 if (offset < entry->start) 198 n = n->rb_left; 199 else if (offset > entry->end) 200 n = n->rb_right; 201 else 202 return n; 203 } 204 if (!prev_ret) 205 return NULL; 206 while(prev && offset > prev_entry->end) { 207 prev = rb_next(prev); 208 prev_entry = rb_entry(prev, struct tree_entry, rb_node); 209 } 210 *prev_ret = prev; 211 return NULL; 212 } 213 214 static inline struct rb_node *tree_search(struct rb_root *root, u64 offset) 215 { 216 struct rb_node *prev; 217 struct rb_node *ret; 218 ret = __tree_search(root, offset, &prev); 219 if (!ret) 220 return prev; 221 return ret; 222 } 223 224 static int tree_delete(struct rb_root *root, u64 offset) 225 { 226 struct rb_node *node; 227 struct tree_entry *entry; 228 229 node = __tree_search(root, offset, NULL); 230 if (!node) 231 return -ENOENT; 232 entry = rb_entry(node, struct tree_entry, rb_node); 233 entry->in_tree = 0; 234 rb_erase(node, root); 235 return 0; 236 } 237 238 /* 239 * add_extent_mapping tries a simple backward merge with existing 240 * mappings. The extent_map struct passed in will be inserted into 241 * the tree directly (no copies made, just a reference taken). 242 */ 243 int add_extent_mapping(struct extent_map_tree *tree, 244 struct extent_map *em) 245 { 246 int ret = 0; 247 struct extent_map *prev = NULL; 248 struct rb_node *rb; 249 250 write_lock_irq(&tree->lock); 251 rb = tree_insert(&tree->map, em->end, &em->rb_node); 252 if (rb) { 253 prev = rb_entry(rb, struct extent_map, rb_node); 254 printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev->start, prev->end, em->start, em->end); 255 ret = -EEXIST; 256 goto out; 257 } 258 atomic_inc(&em->refs); 259 if (em->start != 0) { 260 rb = rb_prev(&em->rb_node); 261 if (rb) 262 prev = rb_entry(rb, struct extent_map, rb_node); 263 if (prev && prev->end + 1 == em->start && 264 ((em->block_start == EXTENT_MAP_HOLE && 265 prev->block_start == EXTENT_MAP_HOLE) || 266 (em->block_start == prev->block_end + 1))) { 267 em->start = prev->start; 268 em->block_start = prev->block_start; 269 rb_erase(&prev->rb_node, &tree->map); 270 prev->in_tree = 0; 271 free_extent_map(prev); 272 } 273 } 274 out: 275 write_unlock_irq(&tree->lock); 276 return ret; 277 } 278 EXPORT_SYMBOL(add_extent_mapping); 279 280 /* 281 * lookup_extent_mapping returns the first extent_map struct in the 282 * tree that intersects the [start, end] (inclusive) range. There may 283 * be additional objects in the tree that intersect, so check the object 284 * returned carefully to make sure you don't need additional lookups. 285 */ 286 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, 287 u64 start, u64 end) 288 { 289 struct extent_map *em; 290 struct rb_node *rb_node; 291 292 read_lock_irq(&tree->lock); 293 rb_node = tree_search(&tree->map, start); 294 if (!rb_node) { 295 em = NULL; 296 goto out; 297 } 298 if (IS_ERR(rb_node)) { 299 em = ERR_PTR(PTR_ERR(rb_node)); 300 goto out; 301 } 302 em = rb_entry(rb_node, struct extent_map, rb_node); 303 if (em->end < start || em->start > end) { 304 em = NULL; 305 goto out; 306 } 307 atomic_inc(&em->refs); 308 out: 309 read_unlock_irq(&tree->lock); 310 return em; 311 } 312 EXPORT_SYMBOL(lookup_extent_mapping); 313 314 /* 315 * removes an extent_map struct from the tree. No reference counts are 316 * dropped, and no checks are done to see if the range is in use 317 */ 318 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) 319 { 320 int ret; 321 322 write_lock_irq(&tree->lock); 323 ret = tree_delete(&tree->map, em->end); 324 write_unlock_irq(&tree->lock); 325 return ret; 326 } 327 EXPORT_SYMBOL(remove_extent_mapping); 328 329 /* 330 * utility function to look for merge candidates inside a given range. 331 * Any extents with matching state are merged together into a single 332 * extent in the tree. Extents with EXTENT_IO in their state field 333 * are not merged because the end_io handlers need to be able to do 334 * operations on them without sleeping (or doing allocations/splits). 335 * 336 * This should be called with the tree lock held. 337 */ 338 static int merge_state(struct extent_map_tree *tree, 339 struct extent_state *state) 340 { 341 struct extent_state *other; 342 struct rb_node *other_node; 343 344 if (state->state & EXTENT_IOBITS) 345 return 0; 346 347 other_node = rb_prev(&state->rb_node); 348 if (other_node) { 349 other = rb_entry(other_node, struct extent_state, rb_node); 350 if (other->end == state->start - 1 && 351 other->state == state->state) { 352 state->start = other->start; 353 other->in_tree = 0; 354 rb_erase(&other->rb_node, &tree->state); 355 free_extent_state(other); 356 } 357 } 358 other_node = rb_next(&state->rb_node); 359 if (other_node) { 360 other = rb_entry(other_node, struct extent_state, rb_node); 361 if (other->start == state->end + 1 && 362 other->state == state->state) { 363 other->start = state->start; 364 state->in_tree = 0; 365 rb_erase(&state->rb_node, &tree->state); 366 free_extent_state(state); 367 } 368 } 369 return 0; 370 } 371 372 /* 373 * insert an extent_state struct into the tree. 'bits' are set on the 374 * struct before it is inserted. 375 * 376 * This may return -EEXIST if the extent is already there, in which case the 377 * state struct is freed. 378 * 379 * The tree lock is not taken internally. This is a utility function and 380 * probably isn't what you want to call (see set/clear_extent_bit). 381 */ 382 static int insert_state(struct extent_map_tree *tree, 383 struct extent_state *state, u64 start, u64 end, 384 int bits) 385 { 386 struct rb_node *node; 387 388 if (end < start) { 389 printk("end < start %Lu %Lu\n", end, start); 390 WARN_ON(1); 391 } 392 state->state |= bits; 393 state->start = start; 394 state->end = end; 395 node = tree_insert(&tree->state, end, &state->rb_node); 396 if (node) { 397 struct extent_state *found; 398 found = rb_entry(node, struct extent_state, rb_node); 399 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end); 400 free_extent_state(state); 401 return -EEXIST; 402 } 403 merge_state(tree, state); 404 return 0; 405 } 406 407 /* 408 * split a given extent state struct in two, inserting the preallocated 409 * struct 'prealloc' as the newly created second half. 'split' indicates an 410 * offset inside 'orig' where it should be split. 411 * 412 * Before calling, 413 * the tree has 'orig' at [orig->start, orig->end]. After calling, there 414 * are two extent state structs in the tree: 415 * prealloc: [orig->start, split - 1] 416 * orig: [ split, orig->end ] 417 * 418 * The tree locks are not taken by this function. They need to be held 419 * by the caller. 420 */ 421 static int split_state(struct extent_map_tree *tree, struct extent_state *orig, 422 struct extent_state *prealloc, u64 split) 423 { 424 struct rb_node *node; 425 prealloc->start = orig->start; 426 prealloc->end = split - 1; 427 prealloc->state = orig->state; 428 orig->start = split; 429 430 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node); 431 if (node) { 432 struct extent_state *found; 433 found = rb_entry(node, struct extent_state, rb_node); 434 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end); 435 free_extent_state(prealloc); 436 return -EEXIST; 437 } 438 return 0; 439 } 440 441 /* 442 * utility function to clear some bits in an extent state struct. 443 * it will optionally wake up any one waiting on this state (wake == 1), or 444 * forcibly remove the state from the tree (delete == 1). 445 * 446 * If no bits are set on the state struct after clearing things, the 447 * struct is freed and removed from the tree 448 */ 449 static int clear_state_bit(struct extent_map_tree *tree, 450 struct extent_state *state, int bits, int wake, 451 int delete) 452 { 453 int ret = state->state & bits; 454 state->state &= ~bits; 455 if (wake) 456 wake_up(&state->wq); 457 if (delete || state->state == 0) { 458 if (state->in_tree) { 459 rb_erase(&state->rb_node, &tree->state); 460 state->in_tree = 0; 461 free_extent_state(state); 462 } else { 463 WARN_ON(1); 464 } 465 } else { 466 merge_state(tree, state); 467 } 468 return ret; 469 } 470 471 /* 472 * clear some bits on a range in the tree. This may require splitting 473 * or inserting elements in the tree, so the gfp mask is used to 474 * indicate which allocations or sleeping are allowed. 475 * 476 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove 477 * the given range from the tree regardless of state (ie for truncate). 478 * 479 * the range [start, end] is inclusive. 480 * 481 * This takes the tree lock, and returns < 0 on error, > 0 if any of the 482 * bits were already set, or zero if none of the bits were already set. 483 */ 484 int clear_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, 485 int bits, int wake, int delete, gfp_t mask) 486 { 487 struct extent_state *state; 488 struct extent_state *prealloc = NULL; 489 struct rb_node *node; 490 unsigned long flags; 491 int err; 492 int set = 0; 493 494 again: 495 if (!prealloc && (mask & __GFP_WAIT)) { 496 prealloc = alloc_extent_state(mask); 497 if (!prealloc) 498 return -ENOMEM; 499 } 500 501 write_lock_irqsave(&tree->lock, flags); 502 /* 503 * this search will find the extents that end after 504 * our range starts 505 */ 506 node = tree_search(&tree->state, start); 507 if (!node) 508 goto out; 509 state = rb_entry(node, struct extent_state, rb_node); 510 if (state->start > end) 511 goto out; 512 WARN_ON(state->end < start); 513 514 /* 515 * | ---- desired range ---- | 516 * | state | or 517 * | ------------- state -------------- | 518 * 519 * We need to split the extent we found, and may flip 520 * bits on second half. 521 * 522 * If the extent we found extends past our range, we 523 * just split and search again. It'll get split again 524 * the next time though. 525 * 526 * If the extent we found is inside our range, we clear 527 * the desired bit on it. 528 */ 529 530 if (state->start < start) { 531 err = split_state(tree, state, prealloc, start); 532 BUG_ON(err == -EEXIST); 533 prealloc = NULL; 534 if (err) 535 goto out; 536 if (state->end <= end) { 537 start = state->end + 1; 538 set |= clear_state_bit(tree, state, bits, 539 wake, delete); 540 } else { 541 start = state->start; 542 } 543 goto search_again; 544 } 545 /* 546 * | ---- desired range ---- | 547 * | state | 548 * We need to split the extent, and clear the bit 549 * on the first half 550 */ 551 if (state->start <= end && state->end > end) { 552 err = split_state(tree, state, prealloc, end + 1); 553 BUG_ON(err == -EEXIST); 554 555 if (wake) 556 wake_up(&state->wq); 557 set |= clear_state_bit(tree, prealloc, bits, 558 wake, delete); 559 prealloc = NULL; 560 goto out; 561 } 562 563 start = state->end + 1; 564 set |= clear_state_bit(tree, state, bits, wake, delete); 565 goto search_again; 566 567 out: 568 write_unlock_irqrestore(&tree->lock, flags); 569 if (prealloc) 570 free_extent_state(prealloc); 571 572 return set; 573 574 search_again: 575 if (start > end) 576 goto out; 577 write_unlock_irqrestore(&tree->lock, flags); 578 if (mask & __GFP_WAIT) 579 cond_resched(); 580 goto again; 581 } 582 EXPORT_SYMBOL(clear_extent_bit); 583 584 static int wait_on_state(struct extent_map_tree *tree, 585 struct extent_state *state) 586 { 587 DEFINE_WAIT(wait); 588 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); 589 read_unlock_irq(&tree->lock); 590 schedule(); 591 read_lock_irq(&tree->lock); 592 finish_wait(&state->wq, &wait); 593 return 0; 594 } 595 596 /* 597 * waits for one or more bits to clear on a range in the state tree. 598 * The range [start, end] is inclusive. 599 * The tree lock is taken by this function 600 */ 601 int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits) 602 { 603 struct extent_state *state; 604 struct rb_node *node; 605 606 read_lock_irq(&tree->lock); 607 again: 608 while (1) { 609 /* 610 * this search will find all the extents that end after 611 * our range starts 612 */ 613 node = tree_search(&tree->state, start); 614 if (!node) 615 break; 616 617 state = rb_entry(node, struct extent_state, rb_node); 618 619 if (state->start > end) 620 goto out; 621 622 if (state->state & bits) { 623 start = state->start; 624 atomic_inc(&state->refs); 625 wait_on_state(tree, state); 626 free_extent_state(state); 627 goto again; 628 } 629 start = state->end + 1; 630 631 if (start > end) 632 break; 633 634 if (need_resched()) { 635 read_unlock_irq(&tree->lock); 636 cond_resched(); 637 read_lock_irq(&tree->lock); 638 } 639 } 640 out: 641 read_unlock_irq(&tree->lock); 642 return 0; 643 } 644 EXPORT_SYMBOL(wait_extent_bit); 645 646 /* 647 * set some bits on a range in the tree. This may require allocations 648 * or sleeping, so the gfp mask is used to indicate what is allowed. 649 * 650 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the 651 * range already has the desired bits set. The start of the existing 652 * range is returned in failed_start in this case. 653 * 654 * [start, end] is inclusive 655 * This takes the tree lock. 656 */ 657 int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, 658 int exclusive, u64 *failed_start, gfp_t mask) 659 { 660 struct extent_state *state; 661 struct extent_state *prealloc = NULL; 662 struct rb_node *node; 663 unsigned long flags; 664 int err = 0; 665 int set; 666 u64 last_start; 667 u64 last_end; 668 again: 669 if (!prealloc && (mask & __GFP_WAIT)) { 670 prealloc = alloc_extent_state(mask); 671 if (!prealloc) 672 return -ENOMEM; 673 } 674 675 write_lock_irqsave(&tree->lock, flags); 676 /* 677 * this search will find all the extents that end after 678 * our range starts. 679 */ 680 node = tree_search(&tree->state, start); 681 if (!node) { 682 err = insert_state(tree, prealloc, start, end, bits); 683 prealloc = NULL; 684 BUG_ON(err == -EEXIST); 685 goto out; 686 } 687 688 state = rb_entry(node, struct extent_state, rb_node); 689 last_start = state->start; 690 last_end = state->end; 691 692 /* 693 * | ---- desired range ---- | 694 * | state | 695 * 696 * Just lock what we found and keep going 697 */ 698 if (state->start == start && state->end <= end) { 699 set = state->state & bits; 700 if (set && exclusive) { 701 *failed_start = state->start; 702 err = -EEXIST; 703 goto out; 704 } 705 state->state |= bits; 706 start = state->end + 1; 707 merge_state(tree, state); 708 goto search_again; 709 } 710 711 /* 712 * | ---- desired range ---- | 713 * | state | 714 * or 715 * | ------------- state -------------- | 716 * 717 * We need to split the extent we found, and may flip bits on 718 * second half. 719 * 720 * If the extent we found extends past our 721 * range, we just split and search again. It'll get split 722 * again the next time though. 723 * 724 * If the extent we found is inside our range, we set the 725 * desired bit on it. 726 */ 727 if (state->start < start) { 728 set = state->state & bits; 729 if (exclusive && set) { 730 *failed_start = start; 731 err = -EEXIST; 732 goto out; 733 } 734 err = split_state(tree, state, prealloc, start); 735 BUG_ON(err == -EEXIST); 736 prealloc = NULL; 737 if (err) 738 goto out; 739 if (state->end <= end) { 740 state->state |= bits; 741 start = state->end + 1; 742 merge_state(tree, state); 743 } else { 744 start = state->start; 745 } 746 goto search_again; 747 } 748 /* 749 * | ---- desired range ---- | 750 * | state | or | state | 751 * 752 * There's a hole, we need to insert something in it and 753 * ignore the extent we found. 754 */ 755 if (state->start > start) { 756 u64 this_end; 757 if (end < last_start) 758 this_end = end; 759 else 760 this_end = last_start -1; 761 err = insert_state(tree, prealloc, start, this_end, 762 bits); 763 prealloc = NULL; 764 BUG_ON(err == -EEXIST); 765 if (err) 766 goto out; 767 start = this_end + 1; 768 goto search_again; 769 } 770 /* 771 * | ---- desired range ---- | 772 * | state | 773 * We need to split the extent, and set the bit 774 * on the first half 775 */ 776 if (state->start <= end && state->end > end) { 777 set = state->state & bits; 778 if (exclusive && set) { 779 *failed_start = start; 780 err = -EEXIST; 781 goto out; 782 } 783 err = split_state(tree, state, prealloc, end + 1); 784 BUG_ON(err == -EEXIST); 785 786 prealloc->state |= bits; 787 merge_state(tree, prealloc); 788 prealloc = NULL; 789 goto out; 790 } 791 792 goto search_again; 793 794 out: 795 write_unlock_irqrestore(&tree->lock, flags); 796 if (prealloc) 797 free_extent_state(prealloc); 798 799 return err; 800 801 search_again: 802 if (start > end) 803 goto out; 804 write_unlock_irqrestore(&tree->lock, flags); 805 if (mask & __GFP_WAIT) 806 cond_resched(); 807 goto again; 808 } 809 EXPORT_SYMBOL(set_extent_bit); 810 811 /* wrappers around set/clear extent bit */ 812 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 813 gfp_t mask) 814 { 815 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, 816 mask); 817 } 818 EXPORT_SYMBOL(set_extent_dirty); 819 820 int set_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 821 int bits, gfp_t mask) 822 { 823 return set_extent_bit(tree, start, end, bits, 0, NULL, 824 mask); 825 } 826 EXPORT_SYMBOL(set_extent_bits); 827 828 int clear_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 829 int bits, gfp_t mask) 830 { 831 return clear_extent_bit(tree, start, end, bits, 0, 0, mask); 832 } 833 EXPORT_SYMBOL(clear_extent_bits); 834 835 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end, 836 gfp_t mask) 837 { 838 return set_extent_bit(tree, start, end, 839 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL, 840 mask); 841 } 842 EXPORT_SYMBOL(set_extent_delalloc); 843 844 int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 845 gfp_t mask) 846 { 847 return clear_extent_bit(tree, start, end, 848 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask); 849 } 850 EXPORT_SYMBOL(clear_extent_dirty); 851 852 int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 853 gfp_t mask) 854 { 855 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, 856 mask); 857 } 858 EXPORT_SYMBOL(set_extent_new); 859 860 int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 861 gfp_t mask) 862 { 863 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask); 864 } 865 EXPORT_SYMBOL(clear_extent_new); 866 867 int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 868 gfp_t mask) 869 { 870 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL, 871 mask); 872 } 873 EXPORT_SYMBOL(set_extent_uptodate); 874 875 int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 876 gfp_t mask) 877 { 878 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask); 879 } 880 EXPORT_SYMBOL(clear_extent_uptodate); 881 882 int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 883 gfp_t mask) 884 { 885 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK, 886 0, NULL, mask); 887 } 888 EXPORT_SYMBOL(set_extent_writeback); 889 890 int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 891 gfp_t mask) 892 { 893 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask); 894 } 895 EXPORT_SYMBOL(clear_extent_writeback); 896 897 int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end) 898 { 899 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK); 900 } 901 EXPORT_SYMBOL(wait_on_extent_writeback); 902 903 /* 904 * locks a range in ascending order, waiting for any locked regions 905 * it hits on the way. [start,end] are inclusive, and this will sleep. 906 */ 907 int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask) 908 { 909 int err; 910 u64 failed_start; 911 while (1) { 912 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 913 &failed_start, mask); 914 if (err == -EEXIST && (mask & __GFP_WAIT)) { 915 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); 916 start = failed_start; 917 } else { 918 break; 919 } 920 WARN_ON(start > end); 921 } 922 return err; 923 } 924 EXPORT_SYMBOL(lock_extent); 925 926 int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, 927 gfp_t mask) 928 { 929 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask); 930 } 931 EXPORT_SYMBOL(unlock_extent); 932 933 /* 934 * helper function to set pages and extents in the tree dirty 935 */ 936 int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end) 937 { 938 unsigned long index = start >> PAGE_CACHE_SHIFT; 939 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 940 struct page *page; 941 942 while (index <= end_index) { 943 page = find_get_page(tree->mapping, index); 944 BUG_ON(!page); 945 __set_page_dirty_nobuffers(page); 946 page_cache_release(page); 947 index++; 948 } 949 set_extent_dirty(tree, start, end, GFP_NOFS); 950 return 0; 951 } 952 EXPORT_SYMBOL(set_range_dirty); 953 954 /* 955 * helper function to set both pages and extents in the tree writeback 956 */ 957 int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end) 958 { 959 unsigned long index = start >> PAGE_CACHE_SHIFT; 960 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 961 struct page *page; 962 963 while (index <= end_index) { 964 page = find_get_page(tree->mapping, index); 965 BUG_ON(!page); 966 set_page_writeback(page); 967 page_cache_release(page); 968 index++; 969 } 970 set_extent_writeback(tree, start, end, GFP_NOFS); 971 return 0; 972 } 973 EXPORT_SYMBOL(set_range_writeback); 974 975 int find_first_extent_bit(struct extent_map_tree *tree, u64 start, 976 u64 *start_ret, u64 *end_ret, int bits) 977 { 978 struct rb_node *node; 979 struct extent_state *state; 980 int ret = 1; 981 982 read_lock_irq(&tree->lock); 983 /* 984 * this search will find all the extents that end after 985 * our range starts. 986 */ 987 node = tree_search(&tree->state, start); 988 if (!node || IS_ERR(node)) { 989 goto out; 990 } 991 992 while(1) { 993 state = rb_entry(node, struct extent_state, rb_node); 994 if (state->end >= start && (state->state & bits)) { 995 *start_ret = state->start; 996 *end_ret = state->end; 997 ret = 0; 998 break; 999 } 1000 node = rb_next(node); 1001 if (!node) 1002 break; 1003 } 1004 out: 1005 read_unlock_irq(&tree->lock); 1006 return ret; 1007 } 1008 EXPORT_SYMBOL(find_first_extent_bit); 1009 1010 u64 find_lock_delalloc_range(struct extent_map_tree *tree, 1011 u64 start, u64 lock_start, u64 *end, u64 max_bytes) 1012 { 1013 struct rb_node *node; 1014 struct extent_state *state; 1015 u64 cur_start = start; 1016 u64 found = 0; 1017 u64 total_bytes = 0; 1018 1019 write_lock_irq(&tree->lock); 1020 /* 1021 * this search will find all the extents that end after 1022 * our range starts. 1023 */ 1024 search_again: 1025 node = tree_search(&tree->state, cur_start); 1026 if (!node || IS_ERR(node)) { 1027 goto out; 1028 } 1029 1030 while(1) { 1031 state = rb_entry(node, struct extent_state, rb_node); 1032 if (state->start != cur_start) { 1033 goto out; 1034 } 1035 if (!(state->state & EXTENT_DELALLOC)) { 1036 goto out; 1037 } 1038 if (state->start >= lock_start) { 1039 if (state->state & EXTENT_LOCKED) { 1040 DEFINE_WAIT(wait); 1041 atomic_inc(&state->refs); 1042 write_unlock_irq(&tree->lock); 1043 schedule(); 1044 write_lock_irq(&tree->lock); 1045 finish_wait(&state->wq, &wait); 1046 free_extent_state(state); 1047 goto search_again; 1048 } 1049 state->state |= EXTENT_LOCKED; 1050 } 1051 found++; 1052 *end = state->end; 1053 cur_start = state->end + 1; 1054 node = rb_next(node); 1055 if (!node) 1056 break; 1057 total_bytes = state->end - state->start + 1; 1058 if (total_bytes >= max_bytes) 1059 break; 1060 } 1061 out: 1062 write_unlock_irq(&tree->lock); 1063 return found; 1064 } 1065 1066 /* 1067 * helper function to lock both pages and extents in the tree. 1068 * pages must be locked first. 1069 */ 1070 int lock_range(struct extent_map_tree *tree, u64 start, u64 end) 1071 { 1072 unsigned long index = start >> PAGE_CACHE_SHIFT; 1073 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1074 struct page *page; 1075 int err; 1076 1077 while (index <= end_index) { 1078 page = grab_cache_page(tree->mapping, index); 1079 if (!page) { 1080 err = -ENOMEM; 1081 goto failed; 1082 } 1083 if (IS_ERR(page)) { 1084 err = PTR_ERR(page); 1085 goto failed; 1086 } 1087 index++; 1088 } 1089 lock_extent(tree, start, end, GFP_NOFS); 1090 return 0; 1091 1092 failed: 1093 /* 1094 * we failed above in getting the page at 'index', so we undo here 1095 * up to but not including the page at 'index' 1096 */ 1097 end_index = index; 1098 index = start >> PAGE_CACHE_SHIFT; 1099 while (index < end_index) { 1100 page = find_get_page(tree->mapping, index); 1101 unlock_page(page); 1102 page_cache_release(page); 1103 index++; 1104 } 1105 return err; 1106 } 1107 EXPORT_SYMBOL(lock_range); 1108 1109 /* 1110 * helper function to unlock both pages and extents in the tree. 1111 */ 1112 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end) 1113 { 1114 unsigned long index = start >> PAGE_CACHE_SHIFT; 1115 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1116 struct page *page; 1117 1118 while (index <= end_index) { 1119 page = find_get_page(tree->mapping, index); 1120 unlock_page(page); 1121 page_cache_release(page); 1122 index++; 1123 } 1124 unlock_extent(tree, start, end, GFP_NOFS); 1125 return 0; 1126 } 1127 EXPORT_SYMBOL(unlock_range); 1128 1129 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private) 1130 { 1131 struct rb_node *node; 1132 struct extent_state *state; 1133 int ret = 0; 1134 1135 write_lock_irq(&tree->lock); 1136 /* 1137 * this search will find all the extents that end after 1138 * our range starts. 1139 */ 1140 node = tree_search(&tree->state, start); 1141 if (!node || IS_ERR(node)) { 1142 ret = -ENOENT; 1143 goto out; 1144 } 1145 state = rb_entry(node, struct extent_state, rb_node); 1146 if (state->start != start) { 1147 ret = -ENOENT; 1148 goto out; 1149 } 1150 state->private = private; 1151 out: 1152 write_unlock_irq(&tree->lock); 1153 return ret; 1154 } 1155 1156 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private) 1157 { 1158 struct rb_node *node; 1159 struct extent_state *state; 1160 int ret = 0; 1161 1162 read_lock_irq(&tree->lock); 1163 /* 1164 * this search will find all the extents that end after 1165 * our range starts. 1166 */ 1167 node = tree_search(&tree->state, start); 1168 if (!node || IS_ERR(node)) { 1169 ret = -ENOENT; 1170 goto out; 1171 } 1172 state = rb_entry(node, struct extent_state, rb_node); 1173 if (state->start != start) { 1174 ret = -ENOENT; 1175 goto out; 1176 } 1177 *private = state->private; 1178 out: 1179 read_unlock_irq(&tree->lock); 1180 return ret; 1181 } 1182 1183 /* 1184 * searches a range in the state tree for a given mask. 1185 * If 'filled' == 1, this returns 1 only if ever extent in the tree 1186 * has the bits set. Otherwise, 1 is returned if any bit in the 1187 * range is found set. 1188 */ 1189 int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end, 1190 int bits, int filled) 1191 { 1192 struct extent_state *state = NULL; 1193 struct rb_node *node; 1194 int bitset = 0; 1195 1196 read_lock_irq(&tree->lock); 1197 node = tree_search(&tree->state, start); 1198 while (node && start <= end) { 1199 state = rb_entry(node, struct extent_state, rb_node); 1200 if (state->start > end) 1201 break; 1202 1203 if (filled && state->start > start) { 1204 bitset = 0; 1205 break; 1206 } 1207 if (state->state & bits) { 1208 bitset = 1; 1209 if (!filled) 1210 break; 1211 } else if (filled) { 1212 bitset = 0; 1213 break; 1214 } 1215 start = state->end + 1; 1216 if (start > end) 1217 break; 1218 node = rb_next(node); 1219 } 1220 read_unlock_irq(&tree->lock); 1221 return bitset; 1222 } 1223 EXPORT_SYMBOL(test_range_bit); 1224 1225 /* 1226 * helper function to set a given page up to date if all the 1227 * extents in the tree for that page are up to date 1228 */ 1229 static int check_page_uptodate(struct extent_map_tree *tree, 1230 struct page *page) 1231 { 1232 u64 start = page->index << PAGE_CACHE_SHIFT; 1233 u64 end = start + PAGE_CACHE_SIZE - 1; 1234 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1)) 1235 SetPageUptodate(page); 1236 return 0; 1237 } 1238 1239 /* 1240 * helper function to unlock a page if all the extents in the tree 1241 * for that page are unlocked 1242 */ 1243 static int check_page_locked(struct extent_map_tree *tree, 1244 struct page *page) 1245 { 1246 u64 start = page->index << PAGE_CACHE_SHIFT; 1247 u64 end = start + PAGE_CACHE_SIZE - 1; 1248 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0)) 1249 unlock_page(page); 1250 return 0; 1251 } 1252 1253 /* 1254 * helper function to end page writeback if all the extents 1255 * in the tree for that page are done with writeback 1256 */ 1257 static int check_page_writeback(struct extent_map_tree *tree, 1258 struct page *page) 1259 { 1260 u64 start = page->index << PAGE_CACHE_SHIFT; 1261 u64 end = start + PAGE_CACHE_SIZE - 1; 1262 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0)) 1263 end_page_writeback(page); 1264 return 0; 1265 } 1266 1267 /* lots and lots of room for performance fixes in the end_bio funcs */ 1268 1269 /* 1270 * after a writepage IO is done, we need to: 1271 * clear the uptodate bits on error 1272 * clear the writeback bits in the extent tree for this IO 1273 * end_page_writeback if the page has no more pending IO 1274 * 1275 * Scheduling is not allowed, so the extent state tree is expected 1276 * to have one and only one object corresponding to this IO. 1277 */ 1278 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1279 static void end_bio_extent_writepage(struct bio *bio, int err) 1280 #else 1281 static int end_bio_extent_writepage(struct bio *bio, 1282 unsigned int bytes_done, int err) 1283 #endif 1284 { 1285 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1286 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1287 struct extent_map_tree *tree = bio->bi_private; 1288 u64 start; 1289 u64 end; 1290 int whole_page; 1291 1292 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1293 if (bio->bi_size) 1294 return 1; 1295 #endif 1296 1297 do { 1298 struct page *page = bvec->bv_page; 1299 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset; 1300 end = start + bvec->bv_len - 1; 1301 1302 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1303 whole_page = 1; 1304 else 1305 whole_page = 0; 1306 1307 if (--bvec >= bio->bi_io_vec) 1308 prefetchw(&bvec->bv_page->flags); 1309 1310 if (!uptodate) { 1311 clear_extent_uptodate(tree, start, end, GFP_ATOMIC); 1312 ClearPageUptodate(page); 1313 SetPageError(page); 1314 } 1315 clear_extent_writeback(tree, start, end, GFP_ATOMIC); 1316 1317 if (whole_page) 1318 end_page_writeback(page); 1319 else 1320 check_page_writeback(tree, page); 1321 if (tree->ops && tree->ops->writepage_end_io_hook) 1322 tree->ops->writepage_end_io_hook(page, start, end); 1323 } while (bvec >= bio->bi_io_vec); 1324 1325 bio_put(bio); 1326 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1327 return 0; 1328 #endif 1329 } 1330 1331 /* 1332 * after a readpage IO is done, we need to: 1333 * clear the uptodate bits on error 1334 * set the uptodate bits if things worked 1335 * set the page up to date if all extents in the tree are uptodate 1336 * clear the lock bit in the extent tree 1337 * unlock the page if there are no other extents locked for it 1338 * 1339 * Scheduling is not allowed, so the extent state tree is expected 1340 * to have one and only one object corresponding to this IO. 1341 */ 1342 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1343 static void end_bio_extent_readpage(struct bio *bio, int err) 1344 #else 1345 static int end_bio_extent_readpage(struct bio *bio, 1346 unsigned int bytes_done, int err) 1347 #endif 1348 { 1349 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1350 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1351 struct extent_map_tree *tree = bio->bi_private; 1352 u64 start; 1353 u64 end; 1354 int whole_page; 1355 int ret; 1356 1357 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1358 if (bio->bi_size) 1359 return 1; 1360 #endif 1361 1362 do { 1363 struct page *page = bvec->bv_page; 1364 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset; 1365 end = start + bvec->bv_len - 1; 1366 1367 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1368 whole_page = 1; 1369 else 1370 whole_page = 0; 1371 1372 if (--bvec >= bio->bi_io_vec) 1373 prefetchw(&bvec->bv_page->flags); 1374 1375 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { 1376 ret = tree->ops->readpage_end_io_hook(page, start, end); 1377 if (ret) 1378 uptodate = 0; 1379 } 1380 if (uptodate) { 1381 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1382 if (whole_page) 1383 SetPageUptodate(page); 1384 else 1385 check_page_uptodate(tree, page); 1386 } else { 1387 ClearPageUptodate(page); 1388 SetPageError(page); 1389 } 1390 1391 unlock_extent(tree, start, end, GFP_ATOMIC); 1392 1393 if (whole_page) 1394 unlock_page(page); 1395 else 1396 check_page_locked(tree, page); 1397 } while (bvec >= bio->bi_io_vec); 1398 1399 bio_put(bio); 1400 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1401 return 0; 1402 #endif 1403 } 1404 1405 /* 1406 * IO done from prepare_write is pretty simple, we just unlock 1407 * the structs in the extent tree when done, and set the uptodate bits 1408 * as appropriate. 1409 */ 1410 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1411 static void end_bio_extent_preparewrite(struct bio *bio, int err) 1412 #else 1413 static int end_bio_extent_preparewrite(struct bio *bio, 1414 unsigned int bytes_done, int err) 1415 #endif 1416 { 1417 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1418 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1419 struct extent_map_tree *tree = bio->bi_private; 1420 u64 start; 1421 u64 end; 1422 1423 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1424 if (bio->bi_size) 1425 return 1; 1426 #endif 1427 1428 do { 1429 struct page *page = bvec->bv_page; 1430 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset; 1431 end = start + bvec->bv_len - 1; 1432 1433 if (--bvec >= bio->bi_io_vec) 1434 prefetchw(&bvec->bv_page->flags); 1435 1436 if (uptodate) { 1437 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1438 } else { 1439 ClearPageUptodate(page); 1440 SetPageError(page); 1441 } 1442 1443 unlock_extent(tree, start, end, GFP_ATOMIC); 1444 1445 } while (bvec >= bio->bi_io_vec); 1446 1447 bio_put(bio); 1448 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1449 return 0; 1450 #endif 1451 } 1452 1453 static int submit_extent_page(int rw, struct extent_map_tree *tree, 1454 struct page *page, sector_t sector, 1455 size_t size, unsigned long offset, 1456 struct block_device *bdev, 1457 bio_end_io_t end_io_func) 1458 { 1459 struct bio *bio; 1460 int ret = 0; 1461 1462 bio = bio_alloc(GFP_NOIO, 1); 1463 1464 bio->bi_sector = sector; 1465 bio->bi_bdev = bdev; 1466 bio->bi_io_vec[0].bv_page = page; 1467 bio->bi_io_vec[0].bv_len = size; 1468 bio->bi_io_vec[0].bv_offset = offset; 1469 1470 bio->bi_vcnt = 1; 1471 bio->bi_idx = 0; 1472 bio->bi_size = size; 1473 1474 bio->bi_end_io = end_io_func; 1475 bio->bi_private = tree; 1476 1477 bio_get(bio); 1478 submit_bio(rw, bio); 1479 1480 if (bio_flagged(bio, BIO_EOPNOTSUPP)) 1481 ret = -EOPNOTSUPP; 1482 1483 bio_put(bio); 1484 return ret; 1485 } 1486 1487 void set_page_extent_mapped(struct page *page) 1488 { 1489 if (!PagePrivate(page)) { 1490 SetPagePrivate(page); 1491 WARN_ON(!page->mapping->a_ops->invalidatepage); 1492 set_page_private(page, EXTENT_PAGE_PRIVATE); 1493 page_cache_get(page); 1494 } 1495 } 1496 1497 /* 1498 * basic readpage implementation. Locked extent state structs are inserted 1499 * into the tree that are removed when the IO is done (by the end_io 1500 * handlers) 1501 */ 1502 int extent_read_full_page(struct extent_map_tree *tree, struct page *page, 1503 get_extent_t *get_extent) 1504 { 1505 struct inode *inode = page->mapping->host; 1506 u64 start = page->index << PAGE_CACHE_SHIFT; 1507 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1508 u64 end; 1509 u64 cur = start; 1510 u64 extent_offset; 1511 u64 last_byte = i_size_read(inode); 1512 u64 block_start; 1513 u64 cur_end; 1514 sector_t sector; 1515 struct extent_map *em; 1516 struct block_device *bdev; 1517 int ret; 1518 int nr = 0; 1519 size_t page_offset = 0; 1520 size_t iosize; 1521 size_t blocksize = inode->i_sb->s_blocksize; 1522 1523 set_page_extent_mapped(page); 1524 1525 end = page_end; 1526 lock_extent(tree, start, end, GFP_NOFS); 1527 1528 while (cur <= end) { 1529 if (cur >= last_byte) { 1530 iosize = PAGE_CACHE_SIZE - page_offset; 1531 zero_user_page(page, page_offset, iosize, KM_USER0); 1532 set_extent_uptodate(tree, cur, cur + iosize - 1, 1533 GFP_NOFS); 1534 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1535 break; 1536 } 1537 em = get_extent(inode, page, page_offset, cur, end, 0); 1538 if (IS_ERR(em) || !em) { 1539 SetPageError(page); 1540 unlock_extent(tree, cur, end, GFP_NOFS); 1541 break; 1542 } 1543 1544 extent_offset = cur - em->start; 1545 BUG_ON(em->end < cur); 1546 BUG_ON(end < cur); 1547 1548 iosize = min(em->end - cur, end - cur) + 1; 1549 cur_end = min(em->end, end); 1550 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1551 sector = (em->block_start + extent_offset) >> 9; 1552 bdev = em->bdev; 1553 block_start = em->block_start; 1554 free_extent_map(em); 1555 em = NULL; 1556 1557 /* we've found a hole, just zero and go on */ 1558 if (block_start == EXTENT_MAP_HOLE) { 1559 zero_user_page(page, page_offset, iosize, KM_USER0); 1560 set_extent_uptodate(tree, cur, cur + iosize - 1, 1561 GFP_NOFS); 1562 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1563 cur = cur + iosize; 1564 page_offset += iosize; 1565 continue; 1566 } 1567 /* the get_extent function already copied into the page */ 1568 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { 1569 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1570 cur = cur + iosize; 1571 page_offset += iosize; 1572 continue; 1573 } 1574 1575 ret = 0; 1576 if (tree->ops && tree->ops->readpage_io_hook) { 1577 ret = tree->ops->readpage_io_hook(page, cur, 1578 cur + iosize - 1); 1579 } 1580 if (!ret) { 1581 ret = submit_extent_page(READ, tree, page, 1582 sector, iosize, page_offset, 1583 bdev, end_bio_extent_readpage); 1584 } 1585 if (ret) 1586 SetPageError(page); 1587 cur = cur + iosize; 1588 page_offset += iosize; 1589 nr++; 1590 } 1591 if (!nr) { 1592 if (!PageError(page)) 1593 SetPageUptodate(page); 1594 unlock_page(page); 1595 } 1596 return 0; 1597 } 1598 EXPORT_SYMBOL(extent_read_full_page); 1599 1600 /* 1601 * the writepage semantics are similar to regular writepage. extent 1602 * records are inserted to lock ranges in the tree, and as dirty areas 1603 * are found, they are marked writeback. Then the lock bits are removed 1604 * and the end_io handler clears the writeback ranges 1605 */ 1606 int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 1607 get_extent_t *get_extent, 1608 struct writeback_control *wbc) 1609 { 1610 struct inode *inode = page->mapping->host; 1611 u64 start = page->index << PAGE_CACHE_SHIFT; 1612 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1613 u64 end; 1614 u64 cur = start; 1615 u64 extent_offset; 1616 u64 last_byte = i_size_read(inode); 1617 u64 block_start; 1618 sector_t sector; 1619 struct extent_map *em; 1620 struct block_device *bdev; 1621 int ret; 1622 int nr = 0; 1623 size_t page_offset = 0; 1624 size_t iosize; 1625 size_t blocksize; 1626 loff_t i_size = i_size_read(inode); 1627 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; 1628 u64 nr_delalloc; 1629 u64 delalloc_end; 1630 1631 WARN_ON(!PageLocked(page)); 1632 if (page->index > end_index) { 1633 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1634 unlock_page(page); 1635 return 0; 1636 } 1637 1638 if (page->index == end_index) { 1639 size_t offset = i_size & (PAGE_CACHE_SIZE - 1); 1640 zero_user_page(page, offset, 1641 PAGE_CACHE_SIZE - offset, KM_USER0); 1642 } 1643 1644 set_page_extent_mapped(page); 1645 1646 lock_extent(tree, start, page_end, GFP_NOFS); 1647 nr_delalloc = find_lock_delalloc_range(tree, start, page_end + 1, 1648 &delalloc_end, 1649 128 * 1024 * 1024); 1650 if (nr_delalloc) { 1651 tree->ops->fill_delalloc(inode, start, delalloc_end); 1652 if (delalloc_end >= page_end + 1) { 1653 clear_extent_bit(tree, page_end + 1, delalloc_end, 1654 EXTENT_LOCKED | EXTENT_DELALLOC, 1655 1, 0, GFP_NOFS); 1656 } 1657 clear_extent_bit(tree, start, page_end, EXTENT_DELALLOC, 1658 0, 0, GFP_NOFS); 1659 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1660 printk("found delalloc bits after clear extent_bit\n"); 1661 } 1662 } else if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1663 printk("found delalloc bits after find_delalloc_range returns 0\n"); 1664 } 1665 1666 end = page_end; 1667 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1668 printk("found delalloc bits after lock_extent\n"); 1669 } 1670 1671 if (last_byte <= start) { 1672 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1673 goto done; 1674 } 1675 1676 set_extent_uptodate(tree, start, page_end, GFP_NOFS); 1677 blocksize = inode->i_sb->s_blocksize; 1678 1679 while (cur <= end) { 1680 if (cur >= last_byte) { 1681 clear_extent_dirty(tree, cur, page_end, GFP_NOFS); 1682 break; 1683 } 1684 em = get_extent(inode, page, page_offset, cur, end, 0); 1685 if (IS_ERR(em) || !em) { 1686 SetPageError(page); 1687 break; 1688 } 1689 1690 extent_offset = cur - em->start; 1691 BUG_ON(em->end < cur); 1692 BUG_ON(end < cur); 1693 iosize = min(em->end - cur, end - cur) + 1; 1694 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1695 sector = (em->block_start + extent_offset) >> 9; 1696 bdev = em->bdev; 1697 block_start = em->block_start; 1698 free_extent_map(em); 1699 em = NULL; 1700 1701 if (block_start == EXTENT_MAP_HOLE || 1702 block_start == EXTENT_MAP_INLINE) { 1703 clear_extent_dirty(tree, cur, 1704 cur + iosize - 1, GFP_NOFS); 1705 cur = cur + iosize; 1706 page_offset += iosize; 1707 continue; 1708 } 1709 1710 /* leave this out until we have a page_mkwrite call */ 1711 if (0 && !test_range_bit(tree, cur, cur + iosize - 1, 1712 EXTENT_DIRTY, 0)) { 1713 cur = cur + iosize; 1714 page_offset += iosize; 1715 continue; 1716 } 1717 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); 1718 if (tree->ops && tree->ops->writepage_io_hook) { 1719 ret = tree->ops->writepage_io_hook(page, cur, 1720 cur + iosize - 1); 1721 } else { 1722 ret = 0; 1723 } 1724 if (ret) 1725 SetPageError(page); 1726 else { 1727 set_range_writeback(tree, cur, cur + iosize - 1); 1728 ret = submit_extent_page(WRITE, tree, page, sector, 1729 iosize, page_offset, bdev, 1730 end_bio_extent_writepage); 1731 if (ret) 1732 SetPageError(page); 1733 } 1734 cur = cur + iosize; 1735 page_offset += iosize; 1736 nr++; 1737 } 1738 done: 1739 unlock_extent(tree, start, page_end, GFP_NOFS); 1740 unlock_page(page); 1741 return 0; 1742 } 1743 EXPORT_SYMBOL(extent_write_full_page); 1744 1745 /* 1746 * basic invalidatepage code, this waits on any locked or writeback 1747 * ranges corresponding to the page, and then deletes any extent state 1748 * records from the tree 1749 */ 1750 int extent_invalidatepage(struct extent_map_tree *tree, 1751 struct page *page, unsigned long offset) 1752 { 1753 u64 start = (page->index << PAGE_CACHE_SHIFT); 1754 u64 end = start + PAGE_CACHE_SIZE - 1; 1755 size_t blocksize = page->mapping->host->i_sb->s_blocksize; 1756 1757 start += (offset + blocksize -1) & ~(blocksize - 1); 1758 if (start > end) 1759 return 0; 1760 1761 lock_extent(tree, start, end, GFP_NOFS); 1762 wait_on_extent_writeback(tree, start, end); 1763 clear_extent_bit(tree, start, end, 1764 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, 1765 1, 1, GFP_NOFS); 1766 return 0; 1767 } 1768 EXPORT_SYMBOL(extent_invalidatepage); 1769 1770 /* 1771 * simple commit_write call, set_range_dirty is used to mark both 1772 * the pages and the extent records as dirty 1773 */ 1774 int extent_commit_write(struct extent_map_tree *tree, 1775 struct inode *inode, struct page *page, 1776 unsigned from, unsigned to) 1777 { 1778 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; 1779 1780 set_page_extent_mapped(page); 1781 set_page_dirty(page); 1782 1783 if (pos > inode->i_size) { 1784 i_size_write(inode, pos); 1785 mark_inode_dirty(inode); 1786 } 1787 return 0; 1788 } 1789 EXPORT_SYMBOL(extent_commit_write); 1790 1791 int extent_prepare_write(struct extent_map_tree *tree, 1792 struct inode *inode, struct page *page, 1793 unsigned from, unsigned to, get_extent_t *get_extent) 1794 { 1795 u64 page_start = page->index << PAGE_CACHE_SHIFT; 1796 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 1797 u64 block_start; 1798 u64 orig_block_start; 1799 u64 block_end; 1800 u64 cur_end; 1801 struct extent_map *em; 1802 unsigned blocksize = 1 << inode->i_blkbits; 1803 size_t page_offset = 0; 1804 size_t block_off_start; 1805 size_t block_off_end; 1806 int err = 0; 1807 int iocount = 0; 1808 int ret = 0; 1809 int isnew; 1810 1811 set_page_extent_mapped(page); 1812 1813 block_start = (page_start + from) & ~((u64)blocksize - 1); 1814 block_end = (page_start + to - 1) | (blocksize - 1); 1815 orig_block_start = block_start; 1816 1817 lock_extent(tree, page_start, page_end, GFP_NOFS); 1818 while(block_start <= block_end) { 1819 em = get_extent(inode, page, page_offset, block_start, 1820 block_end, 1); 1821 if (IS_ERR(em) || !em) { 1822 goto err; 1823 } 1824 cur_end = min(block_end, em->end); 1825 block_off_start = block_start & (PAGE_CACHE_SIZE - 1); 1826 block_off_end = block_off_start + blocksize; 1827 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); 1828 1829 if (!PageUptodate(page) && isnew && 1830 (block_off_end > to || block_off_start < from)) { 1831 void *kaddr; 1832 1833 kaddr = kmap_atomic(page, KM_USER0); 1834 if (block_off_end > to) 1835 memset(kaddr + to, 0, block_off_end - to); 1836 if (block_off_start < from) 1837 memset(kaddr + block_off_start, 0, 1838 from - block_off_start); 1839 flush_dcache_page(page); 1840 kunmap_atomic(kaddr, KM_USER0); 1841 } 1842 if (!isnew && !PageUptodate(page) && 1843 (block_off_end > to || block_off_start < from) && 1844 !test_range_bit(tree, block_start, cur_end, 1845 EXTENT_UPTODATE, 1)) { 1846 u64 sector; 1847 u64 extent_offset = block_start - em->start; 1848 size_t iosize; 1849 sector = (em->block_start + extent_offset) >> 9; 1850 iosize = (cur_end - block_start + blocksize - 1) & 1851 ~((u64)blocksize - 1); 1852 /* 1853 * we've already got the extent locked, but we 1854 * need to split the state such that our end_bio 1855 * handler can clear the lock. 1856 */ 1857 set_extent_bit(tree, block_start, 1858 block_start + iosize - 1, 1859 EXTENT_LOCKED, 0, NULL, GFP_NOFS); 1860 ret = submit_extent_page(READ, tree, page, 1861 sector, iosize, page_offset, em->bdev, 1862 end_bio_extent_preparewrite); 1863 iocount++; 1864 block_start = block_start + iosize; 1865 } else { 1866 set_extent_uptodate(tree, block_start, cur_end, 1867 GFP_NOFS); 1868 unlock_extent(tree, block_start, cur_end, GFP_NOFS); 1869 block_start = cur_end + 1; 1870 } 1871 page_offset = block_start & (PAGE_CACHE_SIZE - 1); 1872 free_extent_map(em); 1873 } 1874 if (iocount) { 1875 wait_extent_bit(tree, orig_block_start, 1876 block_end, EXTENT_LOCKED); 1877 } 1878 check_page_uptodate(tree, page); 1879 err: 1880 /* FIXME, zero out newly allocated blocks on error */ 1881 return err; 1882 } 1883 EXPORT_SYMBOL(extent_prepare_write); 1884 1885 /* 1886 * a helper for releasepage. As long as there are no locked extents 1887 * in the range corresponding to the page, both state records and extent 1888 * map records are removed 1889 */ 1890 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) 1891 { 1892 struct extent_map *em; 1893 u64 start = page->index << PAGE_CACHE_SHIFT; 1894 u64 end = start + PAGE_CACHE_SIZE - 1; 1895 u64 orig_start = start; 1896 int ret = 1; 1897 1898 while (start <= end) { 1899 em = lookup_extent_mapping(tree, start, end); 1900 if (!em || IS_ERR(em)) 1901 break; 1902 if (!test_range_bit(tree, em->start, em->end, 1903 EXTENT_LOCKED, 0)) { 1904 remove_extent_mapping(tree, em); 1905 /* once for the rb tree */ 1906 free_extent_map(em); 1907 } 1908 start = em->end + 1; 1909 /* once for us */ 1910 free_extent_map(em); 1911 } 1912 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) 1913 ret = 0; 1914 else 1915 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, 1916 1, 1, GFP_NOFS); 1917 return ret; 1918 } 1919 EXPORT_SYMBOL(try_release_extent_mapping); 1920 1921 sector_t extent_bmap(struct address_space *mapping, sector_t iblock, 1922 get_extent_t *get_extent) 1923 { 1924 struct inode *inode = mapping->host; 1925 u64 start = iblock << inode->i_blkbits; 1926 u64 end = start + (1 << inode->i_blkbits) - 1; 1927 sector_t sector = 0; 1928 struct extent_map *em; 1929 1930 em = get_extent(inode, NULL, 0, start, end, 0); 1931 if (!em || IS_ERR(em)) 1932 return 0; 1933 1934 if (em->block_start == EXTENT_MAP_INLINE || 1935 em->block_start == EXTENT_MAP_HOLE) 1936 goto out; 1937 1938 sector = (em->block_start + start - em->start) >> inode->i_blkbits; 1939 out: 1940 free_extent_map(em); 1941 return sector; 1942 } 1943 1944 static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb) 1945 { 1946 if (list_empty(&eb->lru)) { 1947 extent_buffer_get(eb); 1948 list_add(&eb->lru, &tree->buffer_lru); 1949 tree->lru_size++; 1950 if (tree->lru_size >= BUFFER_LRU_MAX) { 1951 struct extent_buffer *rm; 1952 rm = list_entry(tree->buffer_lru.prev, 1953 struct extent_buffer, lru); 1954 tree->lru_size--; 1955 list_del(&rm->lru); 1956 free_extent_buffer(rm); 1957 } 1958 } else 1959 list_move(&eb->lru, &tree->buffer_lru); 1960 return 0; 1961 } 1962 static struct extent_buffer *find_lru(struct extent_map_tree *tree, 1963 u64 start, unsigned long len) 1964 { 1965 struct list_head *lru = &tree->buffer_lru; 1966 struct list_head *cur = lru->next; 1967 struct extent_buffer *eb; 1968 1969 if (list_empty(lru)) 1970 return NULL; 1971 1972 do { 1973 eb = list_entry(cur, struct extent_buffer, lru); 1974 if (eb->start == start && eb->len == len) { 1975 extent_buffer_get(eb); 1976 return eb; 1977 } 1978 cur = cur->next; 1979 } while (cur != lru); 1980 return NULL; 1981 } 1982 1983 static inline unsigned long num_extent_pages(u64 start, u64 len) 1984 { 1985 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - 1986 (start >> PAGE_CACHE_SHIFT); 1987 } 1988 1989 static inline struct page *extent_buffer_page(struct extent_buffer *eb, 1990 unsigned long i) 1991 { 1992 struct page *p; 1993 struct address_space *mapping; 1994 1995 if (i == 0) 1996 return eb->first_page; 1997 i += eb->start >> PAGE_CACHE_SHIFT; 1998 mapping = eb->first_page->mapping; 1999 read_lock_irq(&mapping->tree_lock); 2000 p = radix_tree_lookup(&mapping->page_tree, i); 2001 read_unlock_irq(&mapping->tree_lock); 2002 return p; 2003 } 2004 2005 static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, 2006 u64 start, 2007 unsigned long len, 2008 gfp_t mask) 2009 { 2010 struct extent_buffer *eb = NULL; 2011 2012 spin_lock(&tree->lru_lock); 2013 eb = find_lru(tree, start, len); 2014 if (eb) { 2015 goto lru_add; 2016 } 2017 spin_unlock(&tree->lru_lock); 2018 2019 if (eb) { 2020 memset(eb, 0, sizeof(*eb)); 2021 } else { 2022 eb = kmem_cache_zalloc(extent_buffer_cache, mask); 2023 } 2024 INIT_LIST_HEAD(&eb->lru); 2025 eb->start = start; 2026 eb->len = len; 2027 atomic_set(&eb->refs, 1); 2028 2029 spin_lock(&tree->lru_lock); 2030 lru_add: 2031 add_lru(tree, eb); 2032 spin_unlock(&tree->lru_lock); 2033 return eb; 2034 } 2035 2036 static void __free_extent_buffer(struct extent_buffer *eb) 2037 { 2038 kmem_cache_free(extent_buffer_cache, eb); 2039 } 2040 2041 struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 2042 u64 start, unsigned long len, 2043 struct page *page0, 2044 gfp_t mask) 2045 { 2046 unsigned long num_pages = num_extent_pages(start, len); 2047 unsigned long i; 2048 unsigned long index = start >> PAGE_CACHE_SHIFT; 2049 struct extent_buffer *eb; 2050 struct page *p; 2051 struct address_space *mapping = tree->mapping; 2052 int uptodate = 1; 2053 2054 eb = __alloc_extent_buffer(tree, start, len, mask); 2055 if (!eb || IS_ERR(eb)) 2056 return NULL; 2057 2058 if (eb->flags & EXTENT_BUFFER_FILLED) 2059 return eb; 2060 2061 if (page0) { 2062 eb->first_page = page0; 2063 i = 1; 2064 index++; 2065 page_cache_get(page0); 2066 mark_page_accessed(page0); 2067 set_page_extent_mapped(page0); 2068 set_page_private(page0, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2069 len << 2); 2070 } else { 2071 i = 0; 2072 } 2073 for (; i < num_pages; i++, index++) { 2074 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM); 2075 if (!p) { 2076 WARN_ON(1); 2077 /* make sure the free only frees the pages we've 2078 * grabbed a reference on 2079 */ 2080 eb->len = i << PAGE_CACHE_SHIFT; 2081 eb->start &= ~((u64)PAGE_CACHE_SIZE - 1); 2082 goto fail; 2083 } 2084 set_page_extent_mapped(p); 2085 mark_page_accessed(p); 2086 if (i == 0) { 2087 eb->first_page = p; 2088 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2089 len << 2); 2090 } else { 2091 set_page_private(p, EXTENT_PAGE_PRIVATE); 2092 } 2093 if (!PageUptodate(p)) 2094 uptodate = 0; 2095 unlock_page(p); 2096 } 2097 if (uptodate) 2098 eb->flags |= EXTENT_UPTODATE; 2099 eb->flags |= EXTENT_BUFFER_FILLED; 2100 return eb; 2101 fail: 2102 free_extent_buffer(eb); 2103 return NULL; 2104 } 2105 EXPORT_SYMBOL(alloc_extent_buffer); 2106 2107 struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 2108 u64 start, unsigned long len, 2109 gfp_t mask) 2110 { 2111 unsigned long num_pages = num_extent_pages(start, len); 2112 unsigned long i; unsigned long index = start >> PAGE_CACHE_SHIFT; 2113 struct extent_buffer *eb; 2114 struct page *p; 2115 struct address_space *mapping = tree->mapping; 2116 int uptodate = 1; 2117 2118 eb = __alloc_extent_buffer(tree, start, len, mask); 2119 if (!eb || IS_ERR(eb)) 2120 return NULL; 2121 2122 if (eb->flags & EXTENT_BUFFER_FILLED) 2123 return eb; 2124 2125 for (i = 0; i < num_pages; i++, index++) { 2126 p = find_lock_page(mapping, index); 2127 if (!p) { 2128 /* make sure the free only frees the pages we've 2129 * grabbed a reference on 2130 */ 2131 eb->len = i << PAGE_CACHE_SHIFT; 2132 eb->start &= ~((u64)PAGE_CACHE_SIZE - 1); 2133 goto fail; 2134 } 2135 set_page_extent_mapped(p); 2136 mark_page_accessed(p); 2137 2138 if (i == 0) { 2139 eb->first_page = p; 2140 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2141 len << 2); 2142 } else { 2143 set_page_private(p, EXTENT_PAGE_PRIVATE); 2144 } 2145 2146 if (!PageUptodate(p)) 2147 uptodate = 0; 2148 unlock_page(p); 2149 } 2150 if (uptodate) 2151 eb->flags |= EXTENT_UPTODATE; 2152 eb->flags |= EXTENT_BUFFER_FILLED; 2153 return eb; 2154 fail: 2155 free_extent_buffer(eb); 2156 return NULL; 2157 } 2158 EXPORT_SYMBOL(find_extent_buffer); 2159 2160 void free_extent_buffer(struct extent_buffer *eb) 2161 { 2162 unsigned long i; 2163 unsigned long num_pages; 2164 2165 if (!eb) 2166 return; 2167 2168 if (!atomic_dec_and_test(&eb->refs)) 2169 return; 2170 2171 num_pages = num_extent_pages(eb->start, eb->len); 2172 2173 for (i = 0; i < num_pages; i++) { 2174 page_cache_release(extent_buffer_page(eb, i)); 2175 } 2176 __free_extent_buffer(eb); 2177 } 2178 EXPORT_SYMBOL(free_extent_buffer); 2179 2180 int clear_extent_buffer_dirty(struct extent_map_tree *tree, 2181 struct extent_buffer *eb) 2182 { 2183 int set; 2184 unsigned long i; 2185 unsigned long num_pages; 2186 struct page *page; 2187 2188 u64 start = eb->start; 2189 u64 end = start + eb->len - 1; 2190 2191 set = clear_extent_dirty(tree, start, end, GFP_NOFS); 2192 num_pages = num_extent_pages(eb->start, eb->len); 2193 2194 for (i = 0; i < num_pages; i++) { 2195 page = extent_buffer_page(eb, i); 2196 lock_page(page); 2197 /* 2198 * if we're on the last page or the first page and the 2199 * block isn't aligned on a page boundary, do extra checks 2200 * to make sure we don't clean page that is partially dirty 2201 */ 2202 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2203 ((i == num_pages - 1) && 2204 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2205 start = page->index << PAGE_CACHE_SHIFT; 2206 end = start + PAGE_CACHE_SIZE - 1; 2207 if (test_range_bit(tree, start, end, 2208 EXTENT_DIRTY, 0)) { 2209 unlock_page(page); 2210 continue; 2211 } 2212 } 2213 clear_page_dirty_for_io(page); 2214 unlock_page(page); 2215 } 2216 return 0; 2217 } 2218 EXPORT_SYMBOL(clear_extent_buffer_dirty); 2219 2220 int wait_on_extent_buffer_writeback(struct extent_map_tree *tree, 2221 struct extent_buffer *eb) 2222 { 2223 return wait_on_extent_writeback(tree, eb->start, 2224 eb->start + eb->len - 1); 2225 } 2226 EXPORT_SYMBOL(wait_on_extent_buffer_writeback); 2227 2228 int set_extent_buffer_dirty(struct extent_map_tree *tree, 2229 struct extent_buffer *eb) 2230 { 2231 unsigned long i; 2232 unsigned long num_pages; 2233 2234 num_pages = num_extent_pages(eb->start, eb->len); 2235 for (i = 0; i < num_pages; i++) { 2236 struct page *page = extent_buffer_page(eb, i); 2237 /* writepage may need to do something special for the 2238 * first page, we have to make sure page->private is 2239 * properly set. releasepage may drop page->private 2240 * on us if the page isn't already dirty. 2241 */ 2242 if (i == 0) { 2243 lock_page(page); 2244 set_page_private(page, 2245 EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2246 eb->len << 2); 2247 } 2248 __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); 2249 if (i == 0) 2250 unlock_page(page); 2251 } 2252 return set_extent_dirty(tree, eb->start, 2253 eb->start + eb->len - 1, GFP_NOFS); 2254 } 2255 EXPORT_SYMBOL(set_extent_buffer_dirty); 2256 2257 int set_extent_buffer_uptodate(struct extent_map_tree *tree, 2258 struct extent_buffer *eb) 2259 { 2260 unsigned long i; 2261 struct page *page; 2262 unsigned long num_pages; 2263 2264 num_pages = num_extent_pages(eb->start, eb->len); 2265 2266 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, 2267 GFP_NOFS); 2268 for (i = 0; i < num_pages; i++) { 2269 page = extent_buffer_page(eb, i); 2270 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2271 ((i == num_pages - 1) && 2272 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2273 check_page_uptodate(tree, page); 2274 continue; 2275 } 2276 SetPageUptodate(page); 2277 } 2278 return 0; 2279 } 2280 EXPORT_SYMBOL(set_extent_buffer_uptodate); 2281 2282 int extent_buffer_uptodate(struct extent_map_tree *tree, 2283 struct extent_buffer *eb) 2284 { 2285 if (eb->flags & EXTENT_UPTODATE) 2286 return 1; 2287 return test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2288 EXTENT_UPTODATE, 1); 2289 } 2290 EXPORT_SYMBOL(extent_buffer_uptodate); 2291 2292 int read_extent_buffer_pages(struct extent_map_tree *tree, 2293 struct extent_buffer *eb, 2294 u64 start, 2295 int wait) 2296 { 2297 unsigned long i; 2298 unsigned long start_i; 2299 struct page *page; 2300 int err; 2301 int ret = 0; 2302 unsigned long num_pages; 2303 2304 if (eb->flags & EXTENT_UPTODATE) 2305 return 0; 2306 2307 if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2308 EXTENT_UPTODATE, 1)) { 2309 return 0; 2310 } 2311 if (start) { 2312 WARN_ON(start < eb->start); 2313 start_i = (start >> PAGE_CACHE_SHIFT) - 2314 (eb->start >> PAGE_CACHE_SHIFT); 2315 } else { 2316 start_i = 0; 2317 } 2318 2319 num_pages = num_extent_pages(eb->start, eb->len); 2320 for (i = start_i; i < num_pages; i++) { 2321 page = extent_buffer_page(eb, i); 2322 if (PageUptodate(page)) { 2323 continue; 2324 } 2325 if (!wait) { 2326 if (TestSetPageLocked(page)) { 2327 continue; 2328 } 2329 } else { 2330 lock_page(page); 2331 } 2332 if (!PageUptodate(page)) { 2333 err = page->mapping->a_ops->readpage(NULL, page); 2334 if (err) { 2335 ret = err; 2336 } 2337 } else { 2338 unlock_page(page); 2339 } 2340 } 2341 2342 if (ret || !wait) { 2343 return ret; 2344 } 2345 2346 for (i = start_i; i < num_pages; i++) { 2347 page = extent_buffer_page(eb, i); 2348 wait_on_page_locked(page); 2349 if (!PageUptodate(page)) { 2350 ret = -EIO; 2351 } 2352 } 2353 if (!ret) 2354 eb->flags |= EXTENT_UPTODATE; 2355 return ret; 2356 } 2357 EXPORT_SYMBOL(read_extent_buffer_pages); 2358 2359 void read_extent_buffer(struct extent_buffer *eb, void *dstv, 2360 unsigned long start, 2361 unsigned long len) 2362 { 2363 size_t cur; 2364 size_t offset; 2365 struct page *page; 2366 char *kaddr; 2367 char *dst = (char *)dstv; 2368 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2369 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2370 unsigned long num_pages = num_extent_pages(eb->start, eb->len); 2371 2372 WARN_ON(start > eb->len); 2373 WARN_ON(start + len > eb->start + eb->len); 2374 2375 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2376 2377 while(len > 0) { 2378 page = extent_buffer_page(eb, i); 2379 if (!PageUptodate(page)) { 2380 printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); 2381 WARN_ON(1); 2382 } 2383 WARN_ON(!PageUptodate(page)); 2384 2385 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2386 kaddr = kmap_atomic(page, KM_USER1); 2387 memcpy(dst, kaddr + offset, cur); 2388 kunmap_atomic(kaddr, KM_USER1); 2389 2390 dst += cur; 2391 len -= cur; 2392 offset = 0; 2393 i++; 2394 } 2395 } 2396 EXPORT_SYMBOL(read_extent_buffer); 2397 2398 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, 2399 unsigned long min_len, char **token, char **map, 2400 unsigned long *map_start, 2401 unsigned long *map_len, int km) 2402 { 2403 size_t offset = start & (PAGE_CACHE_SIZE - 1); 2404 char *kaddr; 2405 struct page *p; 2406 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2407 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2408 unsigned long end_i = (start_offset + start + min_len - 1) >> 2409 PAGE_CACHE_SHIFT; 2410 2411 if (i != end_i) 2412 return -EINVAL; 2413 2414 if (i == 0) { 2415 offset = start_offset; 2416 *map_start = 0; 2417 } else { 2418 offset = 0; 2419 *map_start = (i << PAGE_CACHE_SHIFT) - start_offset; 2420 } 2421 if (start + min_len > eb->len) { 2422 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); 2423 WARN_ON(1); 2424 } 2425 2426 p = extent_buffer_page(eb, i); 2427 WARN_ON(!PageUptodate(p)); 2428 kaddr = kmap_atomic(p, km); 2429 *token = kaddr; 2430 *map = kaddr + offset; 2431 *map_len = PAGE_CACHE_SIZE - offset; 2432 return 0; 2433 } 2434 EXPORT_SYMBOL(map_private_extent_buffer); 2435 2436 int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 2437 unsigned long min_len, 2438 char **token, char **map, 2439 unsigned long *map_start, 2440 unsigned long *map_len, int km) 2441 { 2442 int err; 2443 int save = 0; 2444 if (eb->map_token) { 2445 unmap_extent_buffer(eb, eb->map_token, km); 2446 eb->map_token = NULL; 2447 save = 1; 2448 } 2449 err = map_private_extent_buffer(eb, start, min_len, token, map, 2450 map_start, map_len, km); 2451 if (!err && save) { 2452 eb->map_token = *token; 2453 eb->kaddr = *map; 2454 eb->map_start = *map_start; 2455 eb->map_len = *map_len; 2456 } 2457 return err; 2458 } 2459 EXPORT_SYMBOL(map_extent_buffer); 2460 2461 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) 2462 { 2463 kunmap_atomic(token, km); 2464 } 2465 EXPORT_SYMBOL(unmap_extent_buffer); 2466 2467 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 2468 unsigned long start, 2469 unsigned long len) 2470 { 2471 size_t cur; 2472 size_t offset; 2473 struct page *page; 2474 char *kaddr; 2475 char *ptr = (char *)ptrv; 2476 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2477 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2478 int ret = 0; 2479 2480 WARN_ON(start > eb->len); 2481 WARN_ON(start + len > eb->start + eb->len); 2482 2483 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2484 2485 while(len > 0) { 2486 page = extent_buffer_page(eb, i); 2487 WARN_ON(!PageUptodate(page)); 2488 2489 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2490 2491 kaddr = kmap_atomic(page, KM_USER0); 2492 ret = memcmp(ptr, kaddr + offset, cur); 2493 kunmap_atomic(kaddr, KM_USER0); 2494 if (ret) 2495 break; 2496 2497 ptr += cur; 2498 len -= cur; 2499 offset = 0; 2500 i++; 2501 } 2502 return ret; 2503 } 2504 EXPORT_SYMBOL(memcmp_extent_buffer); 2505 2506 void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 2507 unsigned long start, unsigned long len) 2508 { 2509 size_t cur; 2510 size_t offset; 2511 struct page *page; 2512 char *kaddr; 2513 char *src = (char *)srcv; 2514 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2515 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2516 2517 WARN_ON(start > eb->len); 2518 WARN_ON(start + len > eb->start + eb->len); 2519 2520 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2521 2522 while(len > 0) { 2523 page = extent_buffer_page(eb, i); 2524 WARN_ON(!PageUptodate(page)); 2525 2526 cur = min(len, PAGE_CACHE_SIZE - offset); 2527 kaddr = kmap_atomic(page, KM_USER1); 2528 memcpy(kaddr + offset, src, cur); 2529 kunmap_atomic(kaddr, KM_USER1); 2530 2531 src += cur; 2532 len -= cur; 2533 offset = 0; 2534 i++; 2535 } 2536 } 2537 EXPORT_SYMBOL(write_extent_buffer); 2538 2539 void memset_extent_buffer(struct extent_buffer *eb, char c, 2540 unsigned long start, unsigned long len) 2541 { 2542 size_t cur; 2543 size_t offset; 2544 struct page *page; 2545 char *kaddr; 2546 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2547 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2548 2549 WARN_ON(start > eb->len); 2550 WARN_ON(start + len > eb->start + eb->len); 2551 2552 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2553 2554 while(len > 0) { 2555 page = extent_buffer_page(eb, i); 2556 WARN_ON(!PageUptodate(page)); 2557 2558 cur = min(len, PAGE_CACHE_SIZE - offset); 2559 kaddr = kmap_atomic(page, KM_USER0); 2560 memset(kaddr + offset, c, cur); 2561 kunmap_atomic(kaddr, KM_USER0); 2562 2563 len -= cur; 2564 offset = 0; 2565 i++; 2566 } 2567 } 2568 EXPORT_SYMBOL(memset_extent_buffer); 2569 2570 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 2571 unsigned long dst_offset, unsigned long src_offset, 2572 unsigned long len) 2573 { 2574 u64 dst_len = dst->len; 2575 size_t cur; 2576 size_t offset; 2577 struct page *page; 2578 char *kaddr; 2579 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2580 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2581 2582 WARN_ON(src->len != dst_len); 2583 2584 offset = (start_offset + dst_offset) & 2585 ((unsigned long)PAGE_CACHE_SIZE - 1); 2586 2587 while(len > 0) { 2588 page = extent_buffer_page(dst, i); 2589 WARN_ON(!PageUptodate(page)); 2590 2591 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset)); 2592 2593 kaddr = kmap_atomic(page, KM_USER0); 2594 read_extent_buffer(src, kaddr + offset, src_offset, cur); 2595 kunmap_atomic(kaddr, KM_USER0); 2596 2597 src_offset += cur; 2598 len -= cur; 2599 offset = 0; 2600 i++; 2601 } 2602 } 2603 EXPORT_SYMBOL(copy_extent_buffer); 2604 2605 static void move_pages(struct page *dst_page, struct page *src_page, 2606 unsigned long dst_off, unsigned long src_off, 2607 unsigned long len) 2608 { 2609 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2610 if (dst_page == src_page) { 2611 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len); 2612 } else { 2613 char *src_kaddr = kmap_atomic(src_page, KM_USER1); 2614 char *p = dst_kaddr + dst_off + len; 2615 char *s = src_kaddr + src_off + len; 2616 2617 while (len--) 2618 *--p = *--s; 2619 2620 kunmap_atomic(src_kaddr, KM_USER1); 2621 } 2622 kunmap_atomic(dst_kaddr, KM_USER0); 2623 } 2624 2625 static void copy_pages(struct page *dst_page, struct page *src_page, 2626 unsigned long dst_off, unsigned long src_off, 2627 unsigned long len) 2628 { 2629 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 2630 char *src_kaddr; 2631 2632 if (dst_page != src_page) 2633 src_kaddr = kmap_atomic(src_page, KM_USER1); 2634 else 2635 src_kaddr = dst_kaddr; 2636 2637 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); 2638 kunmap_atomic(dst_kaddr, KM_USER0); 2639 if (dst_page != src_page) 2640 kunmap_atomic(src_kaddr, KM_USER1); 2641 } 2642 2643 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2644 unsigned long src_offset, unsigned long len) 2645 { 2646 size_t cur; 2647 size_t dst_off_in_page; 2648 size_t src_off_in_page; 2649 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2650 unsigned long dst_i; 2651 unsigned long src_i; 2652 2653 if (src_offset + len > dst->len) { 2654 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2655 src_offset, len, dst->len); 2656 BUG_ON(1); 2657 } 2658 if (dst_offset + len > dst->len) { 2659 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2660 dst_offset, len, dst->len); 2661 BUG_ON(1); 2662 } 2663 2664 while(len > 0) { 2665 dst_off_in_page = (start_offset + dst_offset) & 2666 ((unsigned long)PAGE_CACHE_SIZE - 1); 2667 src_off_in_page = (start_offset + src_offset) & 2668 ((unsigned long)PAGE_CACHE_SIZE - 1); 2669 2670 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 2671 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT; 2672 2673 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - 2674 src_off_in_page)); 2675 cur = min_t(unsigned long, cur, 2676 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page)); 2677 2678 copy_pages(extent_buffer_page(dst, dst_i), 2679 extent_buffer_page(dst, src_i), 2680 dst_off_in_page, src_off_in_page, cur); 2681 2682 src_offset += cur; 2683 dst_offset += cur; 2684 len -= cur; 2685 } 2686 } 2687 EXPORT_SYMBOL(memcpy_extent_buffer); 2688 2689 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 2690 unsigned long src_offset, unsigned long len) 2691 { 2692 size_t cur; 2693 size_t dst_off_in_page; 2694 size_t src_off_in_page; 2695 unsigned long dst_end = dst_offset + len - 1; 2696 unsigned long src_end = src_offset + len - 1; 2697 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 2698 unsigned long dst_i; 2699 unsigned long src_i; 2700 2701 if (src_offset + len > dst->len) { 2702 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 2703 src_offset, len, dst->len); 2704 BUG_ON(1); 2705 } 2706 if (dst_offset + len > dst->len) { 2707 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 2708 dst_offset, len, dst->len); 2709 BUG_ON(1); 2710 } 2711 if (dst_offset < src_offset) { 2712 memcpy_extent_buffer(dst, dst_offset, src_offset, len); 2713 return; 2714 } 2715 while(len > 0) { 2716 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT; 2717 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT; 2718 2719 dst_off_in_page = (start_offset + dst_end) & 2720 ((unsigned long)PAGE_CACHE_SIZE - 1); 2721 src_off_in_page = (start_offset + src_end) & 2722 ((unsigned long)PAGE_CACHE_SIZE - 1); 2723 2724 cur = min_t(unsigned long, len, src_off_in_page + 1); 2725 cur = min(cur, dst_off_in_page + 1); 2726 move_pages(extent_buffer_page(dst, dst_i), 2727 extent_buffer_page(dst, src_i), 2728 dst_off_in_page - cur + 1, 2729 src_off_in_page - cur + 1, cur); 2730 2731 dst_end -= cur; 2732 src_end -= cur; 2733 len -= cur; 2734 } 2735 } 2736 EXPORT_SYMBOL(memmove_extent_buffer); 2737