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 ret = -EEXIST; 277 goto out; 278 } 279 atomic_inc(&em->refs); 280 if (em->start != 0) { 281 rb = rb_prev(&em->rb_node); 282 if (rb) 283 prev = rb_entry(rb, struct extent_map, rb_node); 284 if (prev && prev->end + 1 == em->start && 285 ((em->block_start == EXTENT_MAP_HOLE && 286 prev->block_start == EXTENT_MAP_HOLE) || 287 (em->block_start == EXTENT_MAP_INLINE && 288 prev->block_start == EXTENT_MAP_INLINE) || 289 (em->block_start == EXTENT_MAP_DELALLOC && 290 prev->block_start == EXTENT_MAP_DELALLOC) || 291 (em->block_start < EXTENT_MAP_DELALLOC - 1 && 292 em->block_start == prev->block_end + 1))) { 293 em->start = prev->start; 294 em->block_start = prev->block_start; 295 rb_erase(&prev->rb_node, &tree->map); 296 prev->in_tree = 0; 297 free_extent_map(prev); 298 } 299 } 300 out: 301 write_unlock_irq(&tree->lock); 302 return ret; 303 } 304 EXPORT_SYMBOL(add_extent_mapping); 305 306 /* 307 * lookup_extent_mapping returns the first extent_map struct in the 308 * tree that intersects the [start, end] (inclusive) range. There may 309 * be additional objects in the tree that intersect, so check the object 310 * returned carefully to make sure you don't need additional lookups. 311 */ 312 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, 313 u64 start, u64 end) 314 { 315 struct extent_map *em; 316 struct rb_node *rb_node; 317 318 read_lock_irq(&tree->lock); 319 rb_node = tree_search(&tree->map, start); 320 if (!rb_node) { 321 em = NULL; 322 goto out; 323 } 324 if (IS_ERR(rb_node)) { 325 em = ERR_PTR(PTR_ERR(rb_node)); 326 goto out; 327 } 328 em = rb_entry(rb_node, struct extent_map, rb_node); 329 if (em->end < start || em->start > end) { 330 em = NULL; 331 goto out; 332 } 333 atomic_inc(&em->refs); 334 out: 335 read_unlock_irq(&tree->lock); 336 return em; 337 } 338 EXPORT_SYMBOL(lookup_extent_mapping); 339 340 /* 341 * removes an extent_map struct from the tree. No reference counts are 342 * dropped, and no checks are done to see if the range is in use 343 */ 344 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) 345 { 346 int ret; 347 348 write_lock_irq(&tree->lock); 349 ret = tree_delete(&tree->map, em->end); 350 write_unlock_irq(&tree->lock); 351 return ret; 352 } 353 EXPORT_SYMBOL(remove_extent_mapping); 354 355 /* 356 * utility function to look for merge candidates inside a given range. 357 * Any extents with matching state are merged together into a single 358 * extent in the tree. Extents with EXTENT_IO in their state field 359 * are not merged because the end_io handlers need to be able to do 360 * operations on them without sleeping (or doing allocations/splits). 361 * 362 * This should be called with the tree lock held. 363 */ 364 static int merge_state(struct extent_map_tree *tree, 365 struct extent_state *state) 366 { 367 struct extent_state *other; 368 struct rb_node *other_node; 369 370 if (state->state & EXTENT_IOBITS) 371 return 0; 372 373 other_node = rb_prev(&state->rb_node); 374 if (other_node) { 375 other = rb_entry(other_node, struct extent_state, rb_node); 376 if (other->end == state->start - 1 && 377 other->state == state->state) { 378 state->start = other->start; 379 other->in_tree = 0; 380 rb_erase(&other->rb_node, &tree->state); 381 free_extent_state(other); 382 } 383 } 384 other_node = rb_next(&state->rb_node); 385 if (other_node) { 386 other = rb_entry(other_node, struct extent_state, rb_node); 387 if (other->start == state->end + 1 && 388 other->state == state->state) { 389 other->start = state->start; 390 state->in_tree = 0; 391 rb_erase(&state->rb_node, &tree->state); 392 free_extent_state(state); 393 } 394 } 395 return 0; 396 } 397 398 /* 399 * insert an extent_state struct into the tree. 'bits' are set on the 400 * struct before it is inserted. 401 * 402 * This may return -EEXIST if the extent is already there, in which case the 403 * state struct is freed. 404 * 405 * The tree lock is not taken internally. This is a utility function and 406 * probably isn't what you want to call (see set/clear_extent_bit). 407 */ 408 static int insert_state(struct extent_map_tree *tree, 409 struct extent_state *state, u64 start, u64 end, 410 int bits) 411 { 412 struct rb_node *node; 413 414 if (end < start) { 415 printk("end < start %Lu %Lu\n", end, start); 416 WARN_ON(1); 417 } 418 if (bits & EXTENT_DIRTY) 419 tree->dirty_bytes += end - start + 1; 420 state->state |= bits; 421 state->start = start; 422 state->end = end; 423 node = tree_insert(&tree->state, end, &state->rb_node); 424 if (node) { 425 struct extent_state *found; 426 found = rb_entry(node, struct extent_state, rb_node); 427 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end); 428 free_extent_state(state); 429 return -EEXIST; 430 } 431 merge_state(tree, state); 432 return 0; 433 } 434 435 /* 436 * split a given extent state struct in two, inserting the preallocated 437 * struct 'prealloc' as the newly created second half. 'split' indicates an 438 * offset inside 'orig' where it should be split. 439 * 440 * Before calling, 441 * the tree has 'orig' at [orig->start, orig->end]. After calling, there 442 * are two extent state structs in the tree: 443 * prealloc: [orig->start, split - 1] 444 * orig: [ split, orig->end ] 445 * 446 * The tree locks are not taken by this function. They need to be held 447 * by the caller. 448 */ 449 static int split_state(struct extent_map_tree *tree, struct extent_state *orig, 450 struct extent_state *prealloc, u64 split) 451 { 452 struct rb_node *node; 453 prealloc->start = orig->start; 454 prealloc->end = split - 1; 455 prealloc->state = orig->state; 456 orig->start = split; 457 458 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node); 459 if (node) { 460 struct extent_state *found; 461 found = rb_entry(node, struct extent_state, rb_node); 462 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end); 463 free_extent_state(prealloc); 464 return -EEXIST; 465 } 466 return 0; 467 } 468 469 /* 470 * utility function to clear some bits in an extent state struct. 471 * it will optionally wake up any one waiting on this state (wake == 1), or 472 * forcibly remove the state from the tree (delete == 1). 473 * 474 * If no bits are set on the state struct after clearing things, the 475 * struct is freed and removed from the tree 476 */ 477 static int clear_state_bit(struct extent_map_tree *tree, 478 struct extent_state *state, int bits, int wake, 479 int delete) 480 { 481 int ret = state->state & bits; 482 483 if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) { 484 u64 range = state->end - state->start + 1; 485 WARN_ON(range > tree->dirty_bytes); 486 tree->dirty_bytes -= range; 487 } 488 state->state &= ~bits; 489 if (wake) 490 wake_up(&state->wq); 491 if (delete || state->state == 0) { 492 if (state->in_tree) { 493 rb_erase(&state->rb_node, &tree->state); 494 state->in_tree = 0; 495 free_extent_state(state); 496 } else { 497 WARN_ON(1); 498 } 499 } else { 500 merge_state(tree, state); 501 } 502 return ret; 503 } 504 505 /* 506 * clear some bits on a range in the tree. This may require splitting 507 * or inserting elements in the tree, so the gfp mask is used to 508 * indicate which allocations or sleeping are allowed. 509 * 510 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove 511 * the given range from the tree regardless of state (ie for truncate). 512 * 513 * the range [start, end] is inclusive. 514 * 515 * This takes the tree lock, and returns < 0 on error, > 0 if any of the 516 * bits were already set, or zero if none of the bits were already set. 517 */ 518 int clear_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, 519 int bits, int wake, int delete, gfp_t mask) 520 { 521 struct extent_state *state; 522 struct extent_state *prealloc = NULL; 523 struct rb_node *node; 524 unsigned long flags; 525 int err; 526 int set = 0; 527 528 again: 529 if (!prealloc && (mask & __GFP_WAIT)) { 530 prealloc = alloc_extent_state(mask); 531 if (!prealloc) 532 return -ENOMEM; 533 } 534 535 write_lock_irqsave(&tree->lock, flags); 536 /* 537 * this search will find the extents that end after 538 * our range starts 539 */ 540 node = tree_search(&tree->state, start); 541 if (!node) 542 goto out; 543 state = rb_entry(node, struct extent_state, rb_node); 544 if (state->start > end) 545 goto out; 546 WARN_ON(state->end < start); 547 548 /* 549 * | ---- desired range ---- | 550 * | state | or 551 * | ------------- state -------------- | 552 * 553 * We need to split the extent we found, and may flip 554 * bits on second half. 555 * 556 * If the extent we found extends past our range, we 557 * just split and search again. It'll get split again 558 * the next time though. 559 * 560 * If the extent we found is inside our range, we clear 561 * the desired bit on it. 562 */ 563 564 if (state->start < start) { 565 err = split_state(tree, state, prealloc, start); 566 BUG_ON(err == -EEXIST); 567 prealloc = NULL; 568 if (err) 569 goto out; 570 if (state->end <= end) { 571 start = state->end + 1; 572 set |= clear_state_bit(tree, state, bits, 573 wake, delete); 574 } else { 575 start = state->start; 576 } 577 goto search_again; 578 } 579 /* 580 * | ---- desired range ---- | 581 * | state | 582 * We need to split the extent, and clear the bit 583 * on the first half 584 */ 585 if (state->start <= end && state->end > end) { 586 err = split_state(tree, state, prealloc, end + 1); 587 BUG_ON(err == -EEXIST); 588 589 if (wake) 590 wake_up(&state->wq); 591 set |= clear_state_bit(tree, prealloc, bits, 592 wake, delete); 593 prealloc = NULL; 594 goto out; 595 } 596 597 start = state->end + 1; 598 set |= clear_state_bit(tree, state, bits, wake, delete); 599 goto search_again; 600 601 out: 602 write_unlock_irqrestore(&tree->lock, flags); 603 if (prealloc) 604 free_extent_state(prealloc); 605 606 return set; 607 608 search_again: 609 if (start > end) 610 goto out; 611 write_unlock_irqrestore(&tree->lock, flags); 612 if (mask & __GFP_WAIT) 613 cond_resched(); 614 goto again; 615 } 616 EXPORT_SYMBOL(clear_extent_bit); 617 618 static int wait_on_state(struct extent_map_tree *tree, 619 struct extent_state *state) 620 { 621 DEFINE_WAIT(wait); 622 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); 623 read_unlock_irq(&tree->lock); 624 schedule(); 625 read_lock_irq(&tree->lock); 626 finish_wait(&state->wq, &wait); 627 return 0; 628 } 629 630 /* 631 * waits for one or more bits to clear on a range in the state tree. 632 * The range [start, end] is inclusive. 633 * The tree lock is taken by this function 634 */ 635 int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits) 636 { 637 struct extent_state *state; 638 struct rb_node *node; 639 640 read_lock_irq(&tree->lock); 641 again: 642 while (1) { 643 /* 644 * this search will find all the extents that end after 645 * our range starts 646 */ 647 node = tree_search(&tree->state, start); 648 if (!node) 649 break; 650 651 state = rb_entry(node, struct extent_state, rb_node); 652 653 if (state->start > end) 654 goto out; 655 656 if (state->state & bits) { 657 start = state->start; 658 atomic_inc(&state->refs); 659 wait_on_state(tree, state); 660 free_extent_state(state); 661 goto again; 662 } 663 start = state->end + 1; 664 665 if (start > end) 666 break; 667 668 if (need_resched()) { 669 read_unlock_irq(&tree->lock); 670 cond_resched(); 671 read_lock_irq(&tree->lock); 672 } 673 } 674 out: 675 read_unlock_irq(&tree->lock); 676 return 0; 677 } 678 EXPORT_SYMBOL(wait_extent_bit); 679 680 static void set_state_bits(struct extent_map_tree *tree, 681 struct extent_state *state, 682 int bits) 683 { 684 if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) { 685 u64 range = state->end - state->start + 1; 686 tree->dirty_bytes += range; 687 } 688 state->state |= bits; 689 } 690 691 /* 692 * set some bits on a range in the tree. This may require allocations 693 * or sleeping, so the gfp mask is used to indicate what is allowed. 694 * 695 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the 696 * range already has the desired bits set. The start of the existing 697 * range is returned in failed_start in this case. 698 * 699 * [start, end] is inclusive 700 * This takes the tree lock. 701 */ 702 int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, 703 int exclusive, u64 *failed_start, gfp_t mask) 704 { 705 struct extent_state *state; 706 struct extent_state *prealloc = NULL; 707 struct rb_node *node; 708 unsigned long flags; 709 int err = 0; 710 int set; 711 u64 last_start; 712 u64 last_end; 713 again: 714 if (!prealloc && (mask & __GFP_WAIT)) { 715 prealloc = alloc_extent_state(mask); 716 if (!prealloc) 717 return -ENOMEM; 718 } 719 720 write_lock_irqsave(&tree->lock, flags); 721 /* 722 * this search will find all the extents that end after 723 * our range starts. 724 */ 725 node = tree_search(&tree->state, start); 726 if (!node) { 727 err = insert_state(tree, prealloc, start, end, bits); 728 prealloc = NULL; 729 BUG_ON(err == -EEXIST); 730 goto out; 731 } 732 733 state = rb_entry(node, struct extent_state, rb_node); 734 last_start = state->start; 735 last_end = state->end; 736 737 /* 738 * | ---- desired range ---- | 739 * | state | 740 * 741 * Just lock what we found and keep going 742 */ 743 if (state->start == start && state->end <= end) { 744 set = state->state & bits; 745 if (set && exclusive) { 746 *failed_start = state->start; 747 err = -EEXIST; 748 goto out; 749 } 750 set_state_bits(tree, state, bits); 751 start = state->end + 1; 752 merge_state(tree, state); 753 goto search_again; 754 } 755 756 /* 757 * | ---- desired range ---- | 758 * | state | 759 * or 760 * | ------------- state -------------- | 761 * 762 * We need to split the extent we found, and may flip bits on 763 * second half. 764 * 765 * If the extent we found extends past our 766 * range, we just split and search again. It'll get split 767 * again the next time though. 768 * 769 * If the extent we found is inside our range, we set the 770 * desired bit on it. 771 */ 772 if (state->start < start) { 773 set = state->state & bits; 774 if (exclusive && set) { 775 *failed_start = start; 776 err = -EEXIST; 777 goto out; 778 } 779 err = split_state(tree, state, prealloc, start); 780 BUG_ON(err == -EEXIST); 781 prealloc = NULL; 782 if (err) 783 goto out; 784 if (state->end <= end) { 785 set_state_bits(tree, state, bits); 786 start = state->end + 1; 787 merge_state(tree, state); 788 } else { 789 start = state->start; 790 } 791 goto search_again; 792 } 793 /* 794 * | ---- desired range ---- | 795 * | state | or | state | 796 * 797 * There's a hole, we need to insert something in it and 798 * ignore the extent we found. 799 */ 800 if (state->start > start) { 801 u64 this_end; 802 if (end < last_start) 803 this_end = end; 804 else 805 this_end = last_start -1; 806 err = insert_state(tree, prealloc, start, this_end, 807 bits); 808 prealloc = NULL; 809 BUG_ON(err == -EEXIST); 810 if (err) 811 goto out; 812 start = this_end + 1; 813 goto search_again; 814 } 815 /* 816 * | ---- desired range ---- | 817 * | state | 818 * We need to split the extent, and set the bit 819 * on the first half 820 */ 821 if (state->start <= end && state->end > end) { 822 set = state->state & bits; 823 if (exclusive && set) { 824 *failed_start = start; 825 err = -EEXIST; 826 goto out; 827 } 828 err = split_state(tree, state, prealloc, end + 1); 829 BUG_ON(err == -EEXIST); 830 831 set_state_bits(tree, prealloc, bits); 832 merge_state(tree, prealloc); 833 prealloc = NULL; 834 goto out; 835 } 836 837 goto search_again; 838 839 out: 840 write_unlock_irqrestore(&tree->lock, flags); 841 if (prealloc) 842 free_extent_state(prealloc); 843 844 return err; 845 846 search_again: 847 if (start > end) 848 goto out; 849 write_unlock_irqrestore(&tree->lock, flags); 850 if (mask & __GFP_WAIT) 851 cond_resched(); 852 goto again; 853 } 854 EXPORT_SYMBOL(set_extent_bit); 855 856 /* wrappers around set/clear extent bit */ 857 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 858 gfp_t mask) 859 { 860 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, 861 mask); 862 } 863 EXPORT_SYMBOL(set_extent_dirty); 864 865 int set_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 866 int bits, gfp_t mask) 867 { 868 return set_extent_bit(tree, start, end, bits, 0, NULL, 869 mask); 870 } 871 EXPORT_SYMBOL(set_extent_bits); 872 873 int clear_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 874 int bits, gfp_t mask) 875 { 876 return clear_extent_bit(tree, start, end, bits, 0, 0, mask); 877 } 878 EXPORT_SYMBOL(clear_extent_bits); 879 880 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end, 881 gfp_t mask) 882 { 883 return set_extent_bit(tree, start, end, 884 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL, 885 mask); 886 } 887 EXPORT_SYMBOL(set_extent_delalloc); 888 889 int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 890 gfp_t mask) 891 { 892 return clear_extent_bit(tree, start, end, 893 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask); 894 } 895 EXPORT_SYMBOL(clear_extent_dirty); 896 897 int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 898 gfp_t mask) 899 { 900 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, 901 mask); 902 } 903 EXPORT_SYMBOL(set_extent_new); 904 905 int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 906 gfp_t mask) 907 { 908 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask); 909 } 910 EXPORT_SYMBOL(clear_extent_new); 911 912 int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 913 gfp_t mask) 914 { 915 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL, 916 mask); 917 } 918 EXPORT_SYMBOL(set_extent_uptodate); 919 920 int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 921 gfp_t mask) 922 { 923 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask); 924 } 925 EXPORT_SYMBOL(clear_extent_uptodate); 926 927 int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 928 gfp_t mask) 929 { 930 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK, 931 0, NULL, mask); 932 } 933 EXPORT_SYMBOL(set_extent_writeback); 934 935 int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 936 gfp_t mask) 937 { 938 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask); 939 } 940 EXPORT_SYMBOL(clear_extent_writeback); 941 942 int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end) 943 { 944 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK); 945 } 946 EXPORT_SYMBOL(wait_on_extent_writeback); 947 948 /* 949 * locks a range in ascending order, waiting for any locked regions 950 * it hits on the way. [start,end] are inclusive, and this will sleep. 951 */ 952 int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask) 953 { 954 int err; 955 u64 failed_start; 956 while (1) { 957 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 958 &failed_start, mask); 959 if (err == -EEXIST && (mask & __GFP_WAIT)) { 960 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); 961 start = failed_start; 962 } else { 963 break; 964 } 965 WARN_ON(start > end); 966 } 967 return err; 968 } 969 EXPORT_SYMBOL(lock_extent); 970 971 int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, 972 gfp_t mask) 973 { 974 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask); 975 } 976 EXPORT_SYMBOL(unlock_extent); 977 978 /* 979 * helper function to set pages and extents in the tree dirty 980 */ 981 int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end) 982 { 983 unsigned long index = start >> PAGE_CACHE_SHIFT; 984 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 985 struct page *page; 986 987 while (index <= end_index) { 988 page = find_get_page(tree->mapping, index); 989 BUG_ON(!page); 990 __set_page_dirty_nobuffers(page); 991 page_cache_release(page); 992 index++; 993 } 994 set_extent_dirty(tree, start, end, GFP_NOFS); 995 return 0; 996 } 997 EXPORT_SYMBOL(set_range_dirty); 998 999 /* 1000 * helper function to set both pages and extents in the tree writeback 1001 */ 1002 int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end) 1003 { 1004 unsigned long index = start >> PAGE_CACHE_SHIFT; 1005 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1006 struct page *page; 1007 1008 while (index <= end_index) { 1009 page = find_get_page(tree->mapping, index); 1010 BUG_ON(!page); 1011 set_page_writeback(page); 1012 page_cache_release(page); 1013 index++; 1014 } 1015 set_extent_writeback(tree, start, end, GFP_NOFS); 1016 return 0; 1017 } 1018 EXPORT_SYMBOL(set_range_writeback); 1019 1020 int find_first_extent_bit(struct extent_map_tree *tree, u64 start, 1021 u64 *start_ret, u64 *end_ret, int bits) 1022 { 1023 struct rb_node *node; 1024 struct extent_state *state; 1025 int ret = 1; 1026 1027 read_lock_irq(&tree->lock); 1028 /* 1029 * this search will find all the extents that end after 1030 * our range starts. 1031 */ 1032 node = tree_search(&tree->state, start); 1033 if (!node || IS_ERR(node)) { 1034 goto out; 1035 } 1036 1037 while(1) { 1038 state = rb_entry(node, struct extent_state, rb_node); 1039 if (state->end >= start && (state->state & bits)) { 1040 *start_ret = state->start; 1041 *end_ret = state->end; 1042 ret = 0; 1043 break; 1044 } 1045 node = rb_next(node); 1046 if (!node) 1047 break; 1048 } 1049 out: 1050 read_unlock_irq(&tree->lock); 1051 return ret; 1052 } 1053 EXPORT_SYMBOL(find_first_extent_bit); 1054 1055 u64 find_lock_delalloc_range(struct extent_map_tree *tree, 1056 u64 *start, u64 *end, u64 max_bytes) 1057 { 1058 struct rb_node *node; 1059 struct extent_state *state; 1060 u64 cur_start = *start; 1061 u64 found = 0; 1062 u64 total_bytes = 0; 1063 1064 write_lock_irq(&tree->lock); 1065 /* 1066 * this search will find all the extents that end after 1067 * our range starts. 1068 */ 1069 search_again: 1070 node = tree_search(&tree->state, cur_start); 1071 if (!node || IS_ERR(node)) { 1072 *end = (u64)-1; 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 if (!found) 1083 *end = state->end; 1084 goto out; 1085 } 1086 if (!found) { 1087 struct extent_state *prev_state; 1088 struct rb_node *prev_node = node; 1089 while(1) { 1090 prev_node = rb_prev(prev_node); 1091 if (!prev_node) 1092 break; 1093 prev_state = rb_entry(prev_node, 1094 struct extent_state, 1095 rb_node); 1096 if (!(prev_state->state & EXTENT_DELALLOC)) 1097 break; 1098 state = prev_state; 1099 node = prev_node; 1100 } 1101 } 1102 if (state->state & EXTENT_LOCKED) { 1103 DEFINE_WAIT(wait); 1104 atomic_inc(&state->refs); 1105 prepare_to_wait(&state->wq, &wait, 1106 TASK_UNINTERRUPTIBLE); 1107 write_unlock_irq(&tree->lock); 1108 schedule(); 1109 write_lock_irq(&tree->lock); 1110 finish_wait(&state->wq, &wait); 1111 free_extent_state(state); 1112 goto search_again; 1113 } 1114 state->state |= EXTENT_LOCKED; 1115 if (!found) 1116 *start = state->start; 1117 found++; 1118 *end = state->end; 1119 cur_start = state->end + 1; 1120 node = rb_next(node); 1121 if (!node) 1122 break; 1123 total_bytes += state->end - state->start + 1; 1124 if (total_bytes >= max_bytes) 1125 break; 1126 } 1127 out: 1128 write_unlock_irq(&tree->lock); 1129 return found; 1130 } 1131 1132 u64 count_range_bits(struct extent_map_tree *tree, 1133 u64 *start, u64 search_end, u64 max_bytes, 1134 unsigned long bits) 1135 { 1136 struct rb_node *node; 1137 struct extent_state *state; 1138 u64 cur_start = *start; 1139 u64 total_bytes = 0; 1140 int found = 0; 1141 1142 if (search_end <= cur_start) { 1143 printk("search_end %Lu start %Lu\n", search_end, cur_start); 1144 WARN_ON(1); 1145 return 0; 1146 } 1147 1148 write_lock_irq(&tree->lock); 1149 if (cur_start == 0 && bits == EXTENT_DIRTY) { 1150 total_bytes = tree->dirty_bytes; 1151 goto out; 1152 } 1153 /* 1154 * this search will find all the extents that end after 1155 * our range starts. 1156 */ 1157 node = tree_search(&tree->state, cur_start); 1158 if (!node || IS_ERR(node)) { 1159 goto out; 1160 } 1161 1162 while(1) { 1163 state = rb_entry(node, struct extent_state, rb_node); 1164 if (state->start > search_end) 1165 break; 1166 if (state->end >= cur_start && (state->state & bits)) { 1167 total_bytes += min(search_end, state->end) + 1 - 1168 max(cur_start, state->start); 1169 if (total_bytes >= max_bytes) 1170 break; 1171 if (!found) { 1172 *start = state->start; 1173 found = 1; 1174 } 1175 } 1176 node = rb_next(node); 1177 if (!node) 1178 break; 1179 } 1180 out: 1181 write_unlock_irq(&tree->lock); 1182 return total_bytes; 1183 } 1184 /* 1185 * helper function to lock both pages and extents in the tree. 1186 * pages must be locked first. 1187 */ 1188 int lock_range(struct extent_map_tree *tree, u64 start, u64 end) 1189 { 1190 unsigned long index = start >> PAGE_CACHE_SHIFT; 1191 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1192 struct page *page; 1193 int err; 1194 1195 while (index <= end_index) { 1196 page = grab_cache_page(tree->mapping, index); 1197 if (!page) { 1198 err = -ENOMEM; 1199 goto failed; 1200 } 1201 if (IS_ERR(page)) { 1202 err = PTR_ERR(page); 1203 goto failed; 1204 } 1205 index++; 1206 } 1207 lock_extent(tree, start, end, GFP_NOFS); 1208 return 0; 1209 1210 failed: 1211 /* 1212 * we failed above in getting the page at 'index', so we undo here 1213 * up to but not including the page at 'index' 1214 */ 1215 end_index = index; 1216 index = start >> PAGE_CACHE_SHIFT; 1217 while (index < end_index) { 1218 page = find_get_page(tree->mapping, index); 1219 unlock_page(page); 1220 page_cache_release(page); 1221 index++; 1222 } 1223 return err; 1224 } 1225 EXPORT_SYMBOL(lock_range); 1226 1227 /* 1228 * helper function to unlock both pages and extents in the tree. 1229 */ 1230 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end) 1231 { 1232 unsigned long index = start >> PAGE_CACHE_SHIFT; 1233 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1234 struct page *page; 1235 1236 while (index <= end_index) { 1237 page = find_get_page(tree->mapping, index); 1238 unlock_page(page); 1239 page_cache_release(page); 1240 index++; 1241 } 1242 unlock_extent(tree, start, end, GFP_NOFS); 1243 return 0; 1244 } 1245 EXPORT_SYMBOL(unlock_range); 1246 1247 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private) 1248 { 1249 struct rb_node *node; 1250 struct extent_state *state; 1251 int ret = 0; 1252 1253 write_lock_irq(&tree->lock); 1254 /* 1255 * this search will find all the extents that end after 1256 * our range starts. 1257 */ 1258 node = tree_search(&tree->state, start); 1259 if (!node || IS_ERR(node)) { 1260 ret = -ENOENT; 1261 goto out; 1262 } 1263 state = rb_entry(node, struct extent_state, rb_node); 1264 if (state->start != start) { 1265 ret = -ENOENT; 1266 goto out; 1267 } 1268 state->private = private; 1269 out: 1270 write_unlock_irq(&tree->lock); 1271 return ret; 1272 } 1273 1274 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private) 1275 { 1276 struct rb_node *node; 1277 struct extent_state *state; 1278 int ret = 0; 1279 1280 read_lock_irq(&tree->lock); 1281 /* 1282 * this search will find all the extents that end after 1283 * our range starts. 1284 */ 1285 node = tree_search(&tree->state, start); 1286 if (!node || IS_ERR(node)) { 1287 ret = -ENOENT; 1288 goto out; 1289 } 1290 state = rb_entry(node, struct extent_state, rb_node); 1291 if (state->start != start) { 1292 ret = -ENOENT; 1293 goto out; 1294 } 1295 *private = state->private; 1296 out: 1297 read_unlock_irq(&tree->lock); 1298 return ret; 1299 } 1300 1301 /* 1302 * searches a range in the state tree for a given mask. 1303 * If 'filled' == 1, this returns 1 only if ever extent in the tree 1304 * has the bits set. Otherwise, 1 is returned if any bit in the 1305 * range is found set. 1306 */ 1307 int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end, 1308 int bits, int filled) 1309 { 1310 struct extent_state *state = NULL; 1311 struct rb_node *node; 1312 int bitset = 0; 1313 1314 read_lock_irq(&tree->lock); 1315 node = tree_search(&tree->state, start); 1316 while (node && start <= end) { 1317 state = rb_entry(node, struct extent_state, rb_node); 1318 1319 if (filled && state->start > start) { 1320 bitset = 0; 1321 break; 1322 } 1323 1324 if (state->start > end) 1325 break; 1326 1327 if (state->state & bits) { 1328 bitset = 1; 1329 if (!filled) 1330 break; 1331 } else if (filled) { 1332 bitset = 0; 1333 break; 1334 } 1335 start = state->end + 1; 1336 if (start > end) 1337 break; 1338 node = rb_next(node); 1339 } 1340 read_unlock_irq(&tree->lock); 1341 return bitset; 1342 } 1343 EXPORT_SYMBOL(test_range_bit); 1344 1345 /* 1346 * helper function to set a given page up to date if all the 1347 * extents in the tree for that page are up to date 1348 */ 1349 static int check_page_uptodate(struct extent_map_tree *tree, 1350 struct page *page) 1351 { 1352 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1353 u64 end = start + PAGE_CACHE_SIZE - 1; 1354 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1)) 1355 SetPageUptodate(page); 1356 return 0; 1357 } 1358 1359 /* 1360 * helper function to unlock a page if all the extents in the tree 1361 * for that page are unlocked 1362 */ 1363 static int check_page_locked(struct extent_map_tree *tree, 1364 struct page *page) 1365 { 1366 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1367 u64 end = start + PAGE_CACHE_SIZE - 1; 1368 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0)) 1369 unlock_page(page); 1370 return 0; 1371 } 1372 1373 /* 1374 * helper function to end page writeback if all the extents 1375 * in the tree for that page are done with writeback 1376 */ 1377 static int check_page_writeback(struct extent_map_tree *tree, 1378 struct page *page) 1379 { 1380 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1381 u64 end = start + PAGE_CACHE_SIZE - 1; 1382 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0)) 1383 end_page_writeback(page); 1384 return 0; 1385 } 1386 1387 /* lots and lots of room for performance fixes in the end_bio funcs */ 1388 1389 /* 1390 * after a writepage IO is done, we need to: 1391 * clear the uptodate bits on error 1392 * clear the writeback bits in the extent tree for this IO 1393 * end_page_writeback if the page has no more pending IO 1394 * 1395 * Scheduling is not allowed, so the extent state tree is expected 1396 * to have one and only one object corresponding to this IO. 1397 */ 1398 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1399 static void end_bio_extent_writepage(struct bio *bio, int err) 1400 #else 1401 static int end_bio_extent_writepage(struct bio *bio, 1402 unsigned int bytes_done, int err) 1403 #endif 1404 { 1405 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1406 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1407 struct extent_map_tree *tree = bio->bi_private; 1408 u64 start; 1409 u64 end; 1410 int whole_page; 1411 1412 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1413 if (bio->bi_size) 1414 return 1; 1415 #endif 1416 1417 do { 1418 struct page *page = bvec->bv_page; 1419 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1420 bvec->bv_offset; 1421 end = start + bvec->bv_len - 1; 1422 1423 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1424 whole_page = 1; 1425 else 1426 whole_page = 0; 1427 1428 if (--bvec >= bio->bi_io_vec) 1429 prefetchw(&bvec->bv_page->flags); 1430 1431 if (!uptodate) { 1432 clear_extent_uptodate(tree, start, end, GFP_ATOMIC); 1433 ClearPageUptodate(page); 1434 SetPageError(page); 1435 } 1436 clear_extent_writeback(tree, start, end, GFP_ATOMIC); 1437 1438 if (whole_page) 1439 end_page_writeback(page); 1440 else 1441 check_page_writeback(tree, page); 1442 if (tree->ops && tree->ops->writepage_end_io_hook) 1443 tree->ops->writepage_end_io_hook(page, start, end); 1444 } while (bvec >= bio->bi_io_vec); 1445 1446 bio_put(bio); 1447 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1448 return 0; 1449 #endif 1450 } 1451 1452 /* 1453 * after a readpage IO is done, we need to: 1454 * clear the uptodate bits on error 1455 * set the uptodate bits if things worked 1456 * set the page up to date if all extents in the tree are uptodate 1457 * clear the lock bit in the extent tree 1458 * unlock the page if there are no other extents locked for it 1459 * 1460 * Scheduling is not allowed, so the extent state tree is expected 1461 * to have one and only one object corresponding to this IO. 1462 */ 1463 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1464 static void end_bio_extent_readpage(struct bio *bio, int err) 1465 #else 1466 static int end_bio_extent_readpage(struct bio *bio, 1467 unsigned int bytes_done, int err) 1468 #endif 1469 { 1470 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1471 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1472 struct extent_map_tree *tree = bio->bi_private; 1473 u64 start; 1474 u64 end; 1475 int whole_page; 1476 int ret; 1477 1478 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1479 if (bio->bi_size) 1480 return 1; 1481 #endif 1482 1483 do { 1484 struct page *page = bvec->bv_page; 1485 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1486 bvec->bv_offset; 1487 end = start + bvec->bv_len - 1; 1488 1489 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1490 whole_page = 1; 1491 else 1492 whole_page = 0; 1493 1494 if (--bvec >= bio->bi_io_vec) 1495 prefetchw(&bvec->bv_page->flags); 1496 1497 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { 1498 ret = tree->ops->readpage_end_io_hook(page, start, end); 1499 if (ret) 1500 uptodate = 0; 1501 } 1502 if (uptodate) { 1503 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1504 if (whole_page) 1505 SetPageUptodate(page); 1506 else 1507 check_page_uptodate(tree, page); 1508 } else { 1509 ClearPageUptodate(page); 1510 SetPageError(page); 1511 } 1512 1513 unlock_extent(tree, start, end, GFP_ATOMIC); 1514 1515 if (whole_page) 1516 unlock_page(page); 1517 else 1518 check_page_locked(tree, page); 1519 } while (bvec >= bio->bi_io_vec); 1520 1521 bio_put(bio); 1522 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1523 return 0; 1524 #endif 1525 } 1526 1527 /* 1528 * IO done from prepare_write is pretty simple, we just unlock 1529 * the structs in the extent tree when done, and set the uptodate bits 1530 * as appropriate. 1531 */ 1532 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1533 static void end_bio_extent_preparewrite(struct bio *bio, int err) 1534 #else 1535 static int end_bio_extent_preparewrite(struct bio *bio, 1536 unsigned int bytes_done, int err) 1537 #endif 1538 { 1539 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1540 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1541 struct extent_map_tree *tree = bio->bi_private; 1542 u64 start; 1543 u64 end; 1544 1545 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1546 if (bio->bi_size) 1547 return 1; 1548 #endif 1549 1550 do { 1551 struct page *page = bvec->bv_page; 1552 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1553 bvec->bv_offset; 1554 end = start + bvec->bv_len - 1; 1555 1556 if (--bvec >= bio->bi_io_vec) 1557 prefetchw(&bvec->bv_page->flags); 1558 1559 if (uptodate) { 1560 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1561 } else { 1562 ClearPageUptodate(page); 1563 SetPageError(page); 1564 } 1565 1566 unlock_extent(tree, start, end, GFP_ATOMIC); 1567 1568 } while (bvec >= bio->bi_io_vec); 1569 1570 bio_put(bio); 1571 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1572 return 0; 1573 #endif 1574 } 1575 1576 static struct bio * 1577 extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, 1578 gfp_t gfp_flags) 1579 { 1580 struct bio *bio; 1581 1582 bio = bio_alloc(gfp_flags, nr_vecs); 1583 1584 if (bio == NULL && (current->flags & PF_MEMALLOC)) { 1585 while (!bio && (nr_vecs /= 2)) 1586 bio = bio_alloc(gfp_flags, nr_vecs); 1587 } 1588 1589 if (bio) { 1590 bio->bi_bdev = bdev; 1591 bio->bi_sector = first_sector; 1592 } 1593 return bio; 1594 } 1595 1596 static int submit_one_bio(int rw, struct bio *bio) 1597 { 1598 u64 maxsector; 1599 int ret = 0; 1600 1601 bio_get(bio); 1602 1603 maxsector = bio->bi_bdev->bd_inode->i_size >> 9; 1604 if (maxsector < bio->bi_sector) { 1605 printk("sector too large max %Lu got %llu\n", maxsector, 1606 (unsigned long long)bio->bi_sector); 1607 WARN_ON(1); 1608 } 1609 1610 submit_bio(rw, bio); 1611 if (bio_flagged(bio, BIO_EOPNOTSUPP)) 1612 ret = -EOPNOTSUPP; 1613 bio_put(bio); 1614 return ret; 1615 } 1616 1617 static int submit_extent_page(int rw, struct extent_map_tree *tree, 1618 struct page *page, sector_t sector, 1619 size_t size, unsigned long offset, 1620 struct block_device *bdev, 1621 struct bio **bio_ret, 1622 unsigned long max_pages, 1623 bio_end_io_t end_io_func) 1624 { 1625 int ret = 0; 1626 struct bio *bio; 1627 int nr; 1628 1629 if (bio_ret && *bio_ret) { 1630 bio = *bio_ret; 1631 if (bio->bi_sector + (bio->bi_size >> 9) != sector || 1632 bio_add_page(bio, page, size, offset) < size) { 1633 ret = submit_one_bio(rw, bio); 1634 bio = NULL; 1635 } else { 1636 return 0; 1637 } 1638 } 1639 nr = min_t(int, max_pages, bio_get_nr_vecs(bdev)); 1640 bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH); 1641 if (!bio) { 1642 printk("failed to allocate bio nr %d\n", nr); 1643 } 1644 bio_add_page(bio, page, size, offset); 1645 bio->bi_end_io = end_io_func; 1646 bio->bi_private = tree; 1647 if (bio_ret) { 1648 *bio_ret = bio; 1649 } else { 1650 ret = submit_one_bio(rw, bio); 1651 } 1652 1653 return ret; 1654 } 1655 1656 void set_page_extent_mapped(struct page *page) 1657 { 1658 if (!PagePrivate(page)) { 1659 SetPagePrivate(page); 1660 WARN_ON(!page->mapping->a_ops->invalidatepage); 1661 set_page_private(page, EXTENT_PAGE_PRIVATE); 1662 page_cache_get(page); 1663 } 1664 } 1665 1666 void set_page_extent_head(struct page *page, unsigned long len) 1667 { 1668 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2); 1669 } 1670 1671 /* 1672 * basic readpage implementation. Locked extent state structs are inserted 1673 * into the tree that are removed when the IO is done (by the end_io 1674 * handlers) 1675 */ 1676 static int __extent_read_full_page(struct extent_map_tree *tree, 1677 struct page *page, 1678 get_extent_t *get_extent, 1679 struct bio **bio) 1680 { 1681 struct inode *inode = page->mapping->host; 1682 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1683 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1684 u64 end; 1685 u64 cur = start; 1686 u64 extent_offset; 1687 u64 last_byte = i_size_read(inode); 1688 u64 block_start; 1689 u64 cur_end; 1690 sector_t sector; 1691 struct extent_map *em; 1692 struct block_device *bdev; 1693 int ret; 1694 int nr = 0; 1695 size_t page_offset = 0; 1696 size_t iosize; 1697 size_t blocksize = inode->i_sb->s_blocksize; 1698 1699 set_page_extent_mapped(page); 1700 1701 end = page_end; 1702 lock_extent(tree, start, end, GFP_NOFS); 1703 1704 while (cur <= end) { 1705 if (cur >= last_byte) { 1706 char *userpage; 1707 iosize = PAGE_CACHE_SIZE - page_offset; 1708 userpage = kmap_atomic(page, KM_USER0); 1709 memset(userpage + page_offset, 0, iosize); 1710 flush_dcache_page(page); 1711 kunmap_atomic(userpage, KM_USER0); 1712 set_extent_uptodate(tree, cur, cur + iosize - 1, 1713 GFP_NOFS); 1714 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1715 break; 1716 } 1717 em = get_extent(inode, page, page_offset, cur, end, 0); 1718 if (IS_ERR(em) || !em) { 1719 SetPageError(page); 1720 unlock_extent(tree, cur, end, GFP_NOFS); 1721 break; 1722 } 1723 1724 extent_offset = cur - em->start; 1725 BUG_ON(em->end < cur); 1726 BUG_ON(end < cur); 1727 1728 iosize = min(em->end - cur, end - cur) + 1; 1729 cur_end = min(em->end, end); 1730 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1731 sector = (em->block_start + extent_offset) >> 9; 1732 bdev = em->bdev; 1733 block_start = em->block_start; 1734 free_extent_map(em); 1735 em = NULL; 1736 1737 /* we've found a hole, just zero and go on */ 1738 if (block_start == EXTENT_MAP_HOLE) { 1739 char *userpage; 1740 userpage = kmap_atomic(page, KM_USER0); 1741 memset(userpage + page_offset, 0, iosize); 1742 flush_dcache_page(page); 1743 kunmap_atomic(userpage, KM_USER0); 1744 1745 set_extent_uptodate(tree, cur, cur + iosize - 1, 1746 GFP_NOFS); 1747 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1748 cur = cur + iosize; 1749 page_offset += iosize; 1750 continue; 1751 } 1752 /* the get_extent function already copied into the page */ 1753 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { 1754 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1755 cur = cur + iosize; 1756 page_offset += iosize; 1757 continue; 1758 } 1759 1760 ret = 0; 1761 if (tree->ops && tree->ops->readpage_io_hook) { 1762 ret = tree->ops->readpage_io_hook(page, cur, 1763 cur + iosize - 1); 1764 } 1765 if (!ret) { 1766 unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1; 1767 nr -= page->index; 1768 ret = submit_extent_page(READ, tree, page, 1769 sector, iosize, page_offset, 1770 bdev, bio, nr, 1771 end_bio_extent_readpage); 1772 } 1773 if (ret) 1774 SetPageError(page); 1775 cur = cur + iosize; 1776 page_offset += iosize; 1777 nr++; 1778 } 1779 if (!nr) { 1780 if (!PageError(page)) 1781 SetPageUptodate(page); 1782 unlock_page(page); 1783 } 1784 return 0; 1785 } 1786 1787 int extent_read_full_page(struct extent_map_tree *tree, struct page *page, 1788 get_extent_t *get_extent) 1789 { 1790 struct bio *bio = NULL; 1791 int ret; 1792 1793 ret = __extent_read_full_page(tree, page, get_extent, &bio); 1794 if (bio) 1795 submit_one_bio(READ, bio); 1796 return ret; 1797 } 1798 EXPORT_SYMBOL(extent_read_full_page); 1799 1800 /* 1801 * the writepage semantics are similar to regular writepage. extent 1802 * records are inserted to lock ranges in the tree, and as dirty areas 1803 * are found, they are marked writeback. Then the lock bits are removed 1804 * and the end_io handler clears the writeback ranges 1805 */ 1806 static int __extent_writepage(struct page *page, struct writeback_control *wbc, 1807 void *data) 1808 { 1809 struct inode *inode = page->mapping->host; 1810 struct extent_page_data *epd = data; 1811 struct extent_map_tree *tree = epd->tree; 1812 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1813 u64 delalloc_start; 1814 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1815 u64 end; 1816 u64 cur = start; 1817 u64 extent_offset; 1818 u64 last_byte = i_size_read(inode); 1819 u64 block_start; 1820 u64 iosize; 1821 sector_t sector; 1822 struct extent_map *em; 1823 struct block_device *bdev; 1824 int ret; 1825 int nr = 0; 1826 size_t page_offset = 0; 1827 size_t blocksize; 1828 loff_t i_size = i_size_read(inode); 1829 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; 1830 u64 nr_delalloc; 1831 u64 delalloc_end; 1832 1833 WARN_ON(!PageLocked(page)); 1834 if (page->index > end_index) { 1835 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1836 unlock_page(page); 1837 return 0; 1838 } 1839 1840 if (page->index == end_index) { 1841 char *userpage; 1842 1843 size_t offset = i_size & (PAGE_CACHE_SIZE - 1); 1844 1845 userpage = kmap_atomic(page, KM_USER0); 1846 memset(userpage + offset, 0, PAGE_CACHE_SIZE - offset); 1847 flush_dcache_page(page); 1848 kunmap_atomic(userpage, KM_USER0); 1849 } 1850 1851 set_page_extent_mapped(page); 1852 1853 delalloc_start = start; 1854 delalloc_end = 0; 1855 while(delalloc_end < page_end) { 1856 nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start, 1857 &delalloc_end, 1858 128 * 1024 * 1024); 1859 if (nr_delalloc == 0) { 1860 delalloc_start = delalloc_end + 1; 1861 continue; 1862 } 1863 tree->ops->fill_delalloc(inode, delalloc_start, 1864 delalloc_end); 1865 clear_extent_bit(tree, delalloc_start, 1866 delalloc_end, 1867 EXTENT_LOCKED | EXTENT_DELALLOC, 1868 1, 0, GFP_NOFS); 1869 delalloc_start = delalloc_end + 1; 1870 } 1871 lock_extent(tree, start, page_end, GFP_NOFS); 1872 1873 end = page_end; 1874 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1875 printk("found delalloc bits after lock_extent\n"); 1876 } 1877 1878 if (last_byte <= start) { 1879 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1880 goto done; 1881 } 1882 1883 set_extent_uptodate(tree, start, page_end, GFP_NOFS); 1884 blocksize = inode->i_sb->s_blocksize; 1885 1886 while (cur <= end) { 1887 if (cur >= last_byte) { 1888 clear_extent_dirty(tree, cur, page_end, GFP_NOFS); 1889 break; 1890 } 1891 em = epd->get_extent(inode, page, page_offset, cur, end, 1); 1892 if (IS_ERR(em) || !em) { 1893 SetPageError(page); 1894 break; 1895 } 1896 1897 extent_offset = cur - em->start; 1898 BUG_ON(em->end < cur); 1899 BUG_ON(end < cur); 1900 iosize = min(em->end - cur, end - cur) + 1; 1901 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1902 sector = (em->block_start + extent_offset) >> 9; 1903 bdev = em->bdev; 1904 block_start = em->block_start; 1905 free_extent_map(em); 1906 em = NULL; 1907 1908 if (block_start == EXTENT_MAP_HOLE || 1909 block_start == EXTENT_MAP_INLINE) { 1910 clear_extent_dirty(tree, cur, 1911 cur + iosize - 1, GFP_NOFS); 1912 cur = cur + iosize; 1913 page_offset += iosize; 1914 continue; 1915 } 1916 1917 /* leave this out until we have a page_mkwrite call */ 1918 if (0 && !test_range_bit(tree, cur, cur + iosize - 1, 1919 EXTENT_DIRTY, 0)) { 1920 cur = cur + iosize; 1921 page_offset += iosize; 1922 continue; 1923 } 1924 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); 1925 if (tree->ops && tree->ops->writepage_io_hook) { 1926 ret = tree->ops->writepage_io_hook(page, cur, 1927 cur + iosize - 1); 1928 } else { 1929 ret = 0; 1930 } 1931 if (ret) 1932 SetPageError(page); 1933 else { 1934 unsigned long max_nr = end_index + 1; 1935 set_range_writeback(tree, cur, cur + iosize - 1); 1936 if (!PageWriteback(page)) { 1937 printk("warning page %lu not writeback, " 1938 "cur %llu end %llu\n", page->index, 1939 (unsigned long long)cur, 1940 (unsigned long long)end); 1941 } 1942 1943 ret = submit_extent_page(WRITE, tree, page, sector, 1944 iosize, page_offset, bdev, 1945 &epd->bio, max_nr, 1946 end_bio_extent_writepage); 1947 if (ret) 1948 SetPageError(page); 1949 } 1950 cur = cur + iosize; 1951 page_offset += iosize; 1952 nr++; 1953 } 1954 done: 1955 if (nr == 0) { 1956 /* make sure the mapping tag for page dirty gets cleared */ 1957 set_page_writeback(page); 1958 end_page_writeback(page); 1959 } 1960 unlock_extent(tree, start, page_end, GFP_NOFS); 1961 unlock_page(page); 1962 return 0; 1963 } 1964 1965 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18) 1966 1967 /* Taken directly from 2.6.23 for 2.6.18 back port */ 1968 typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, 1969 void *data); 1970 1971 /** 1972 * write_cache_pages - walk the list of dirty pages of the given address space 1973 * and write all of them. 1974 * @mapping: address space structure to write 1975 * @wbc: subtract the number of written pages from *@wbc->nr_to_write 1976 * @writepage: function called for each page 1977 * @data: data passed to writepage function 1978 * 1979 * If a page is already under I/O, write_cache_pages() skips it, even 1980 * if it's dirty. This is desirable behaviour for memory-cleaning writeback, 1981 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync() 1982 * and msync() need to guarantee that all the data which was dirty at the time 1983 * the call was made get new I/O started against them. If wbc->sync_mode is 1984 * WB_SYNC_ALL then we were called for data integrity and we must wait for 1985 * existing IO to complete. 1986 */ 1987 static int write_cache_pages(struct address_space *mapping, 1988 struct writeback_control *wbc, writepage_t writepage, 1989 void *data) 1990 { 1991 struct backing_dev_info *bdi = mapping->backing_dev_info; 1992 int ret = 0; 1993 int done = 0; 1994 struct pagevec pvec; 1995 int nr_pages; 1996 pgoff_t index; 1997 pgoff_t end; /* Inclusive */ 1998 int scanned = 0; 1999 int range_whole = 0; 2000 2001 if (wbc->nonblocking && bdi_write_congested(bdi)) { 2002 wbc->encountered_congestion = 1; 2003 return 0; 2004 } 2005 2006 pagevec_init(&pvec, 0); 2007 if (wbc->range_cyclic) { 2008 index = mapping->writeback_index; /* Start from prev offset */ 2009 end = -1; 2010 } else { 2011 index = wbc->range_start >> PAGE_CACHE_SHIFT; 2012 end = wbc->range_end >> PAGE_CACHE_SHIFT; 2013 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) 2014 range_whole = 1; 2015 scanned = 1; 2016 } 2017 retry: 2018 while (!done && (index <= end) && 2019 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, 2020 PAGECACHE_TAG_DIRTY, 2021 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { 2022 unsigned i; 2023 2024 scanned = 1; 2025 for (i = 0; i < nr_pages; i++) { 2026 struct page *page = pvec.pages[i]; 2027 2028 /* 2029 * At this point we hold neither mapping->tree_lock nor 2030 * lock on the page itself: the page may be truncated or 2031 * invalidated (changing page->mapping to NULL), or even 2032 * swizzled back from swapper_space to tmpfs file 2033 * mapping 2034 */ 2035 lock_page(page); 2036 2037 if (unlikely(page->mapping != mapping)) { 2038 unlock_page(page); 2039 continue; 2040 } 2041 2042 if (!wbc->range_cyclic && page->index > end) { 2043 done = 1; 2044 unlock_page(page); 2045 continue; 2046 } 2047 2048 if (wbc->sync_mode != WB_SYNC_NONE) 2049 wait_on_page_writeback(page); 2050 2051 if (PageWriteback(page) || 2052 !clear_page_dirty_for_io(page)) { 2053 unlock_page(page); 2054 continue; 2055 } 2056 2057 ret = (*writepage)(page, wbc, data); 2058 2059 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) { 2060 unlock_page(page); 2061 ret = 0; 2062 } 2063 if (ret || (--(wbc->nr_to_write) <= 0)) 2064 done = 1; 2065 if (wbc->nonblocking && bdi_write_congested(bdi)) { 2066 wbc->encountered_congestion = 1; 2067 done = 1; 2068 } 2069 } 2070 pagevec_release(&pvec); 2071 cond_resched(); 2072 } 2073 if (!scanned && !done) { 2074 /* 2075 * We hit the last page and there is more work to be done: wrap 2076 * back to the start of the file 2077 */ 2078 scanned = 1; 2079 index = 0; 2080 goto retry; 2081 } 2082 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) 2083 mapping->writeback_index = index; 2084 return ret; 2085 } 2086 #endif 2087 2088 int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 2089 get_extent_t *get_extent, 2090 struct writeback_control *wbc) 2091 { 2092 int ret; 2093 struct address_space *mapping = page->mapping; 2094 struct extent_page_data epd = { 2095 .bio = NULL, 2096 .tree = tree, 2097 .get_extent = get_extent, 2098 }; 2099 struct writeback_control wbc_writepages = { 2100 .bdi = wbc->bdi, 2101 .sync_mode = WB_SYNC_NONE, 2102 .older_than_this = NULL, 2103 .nr_to_write = 64, 2104 .range_start = page_offset(page) + PAGE_CACHE_SIZE, 2105 .range_end = (loff_t)-1, 2106 }; 2107 2108 2109 ret = __extent_writepage(page, wbc, &epd); 2110 2111 write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd); 2112 if (epd.bio) { 2113 submit_one_bio(WRITE, epd.bio); 2114 } 2115 return ret; 2116 } 2117 EXPORT_SYMBOL(extent_write_full_page); 2118 2119 2120 int extent_writepages(struct extent_map_tree *tree, 2121 struct address_space *mapping, 2122 get_extent_t *get_extent, 2123 struct writeback_control *wbc) 2124 { 2125 int ret = 0; 2126 struct extent_page_data epd = { 2127 .bio = NULL, 2128 .tree = tree, 2129 .get_extent = get_extent, 2130 }; 2131 2132 ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd); 2133 if (epd.bio) { 2134 submit_one_bio(WRITE, epd.bio); 2135 } 2136 return ret; 2137 } 2138 EXPORT_SYMBOL(extent_writepages); 2139 2140 int extent_readpages(struct extent_map_tree *tree, 2141 struct address_space *mapping, 2142 struct list_head *pages, unsigned nr_pages, 2143 get_extent_t get_extent) 2144 { 2145 struct bio *bio = NULL; 2146 unsigned page_idx; 2147 struct pagevec pvec; 2148 2149 pagevec_init(&pvec, 0); 2150 for (page_idx = 0; page_idx < nr_pages; page_idx++) { 2151 struct page *page = list_entry(pages->prev, struct page, lru); 2152 2153 prefetchw(&page->flags); 2154 list_del(&page->lru); 2155 /* 2156 * what we want to do here is call add_to_page_cache_lru, 2157 * but that isn't exported, so we reproduce it here 2158 */ 2159 if (!add_to_page_cache(page, mapping, 2160 page->index, GFP_KERNEL)) { 2161 2162 /* open coding of lru_cache_add, also not exported */ 2163 page_cache_get(page); 2164 if (!pagevec_add(&pvec, page)) 2165 __pagevec_lru_add(&pvec); 2166 __extent_read_full_page(tree, page, get_extent, &bio); 2167 } 2168 page_cache_release(page); 2169 } 2170 if (pagevec_count(&pvec)) 2171 __pagevec_lru_add(&pvec); 2172 BUG_ON(!list_empty(pages)); 2173 if (bio) 2174 submit_one_bio(READ, bio); 2175 return 0; 2176 } 2177 EXPORT_SYMBOL(extent_readpages); 2178 2179 /* 2180 * basic invalidatepage code, this waits on any locked or writeback 2181 * ranges corresponding to the page, and then deletes any extent state 2182 * records from the tree 2183 */ 2184 int extent_invalidatepage(struct extent_map_tree *tree, 2185 struct page *page, unsigned long offset) 2186 { 2187 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT); 2188 u64 end = start + PAGE_CACHE_SIZE - 1; 2189 size_t blocksize = page->mapping->host->i_sb->s_blocksize; 2190 2191 start += (offset + blocksize -1) & ~(blocksize - 1); 2192 if (start > end) 2193 return 0; 2194 2195 lock_extent(tree, start, end, GFP_NOFS); 2196 wait_on_extent_writeback(tree, start, end); 2197 clear_extent_bit(tree, start, end, 2198 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, 2199 1, 1, GFP_NOFS); 2200 return 0; 2201 } 2202 EXPORT_SYMBOL(extent_invalidatepage); 2203 2204 /* 2205 * simple commit_write call, set_range_dirty is used to mark both 2206 * the pages and the extent records as dirty 2207 */ 2208 int extent_commit_write(struct extent_map_tree *tree, 2209 struct inode *inode, struct page *page, 2210 unsigned from, unsigned to) 2211 { 2212 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; 2213 2214 set_page_extent_mapped(page); 2215 set_page_dirty(page); 2216 2217 if (pos > inode->i_size) { 2218 i_size_write(inode, pos); 2219 mark_inode_dirty(inode); 2220 } 2221 return 0; 2222 } 2223 EXPORT_SYMBOL(extent_commit_write); 2224 2225 int extent_prepare_write(struct extent_map_tree *tree, 2226 struct inode *inode, struct page *page, 2227 unsigned from, unsigned to, get_extent_t *get_extent) 2228 { 2229 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 2230 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 2231 u64 block_start; 2232 u64 orig_block_start; 2233 u64 block_end; 2234 u64 cur_end; 2235 struct extent_map *em; 2236 unsigned blocksize = 1 << inode->i_blkbits; 2237 size_t page_offset = 0; 2238 size_t block_off_start; 2239 size_t block_off_end; 2240 int err = 0; 2241 int iocount = 0; 2242 int ret = 0; 2243 int isnew; 2244 2245 set_page_extent_mapped(page); 2246 2247 block_start = (page_start + from) & ~((u64)blocksize - 1); 2248 block_end = (page_start + to - 1) | (blocksize - 1); 2249 orig_block_start = block_start; 2250 2251 lock_extent(tree, page_start, page_end, GFP_NOFS); 2252 while(block_start <= block_end) { 2253 em = get_extent(inode, page, page_offset, block_start, 2254 block_end, 1); 2255 if (IS_ERR(em) || !em) { 2256 goto err; 2257 } 2258 cur_end = min(block_end, em->end); 2259 block_off_start = block_start & (PAGE_CACHE_SIZE - 1); 2260 block_off_end = block_off_start + blocksize; 2261 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); 2262 2263 if (!PageUptodate(page) && isnew && 2264 (block_off_end > to || block_off_start < from)) { 2265 void *kaddr; 2266 2267 kaddr = kmap_atomic(page, KM_USER0); 2268 if (block_off_end > to) 2269 memset(kaddr + to, 0, block_off_end - to); 2270 if (block_off_start < from) 2271 memset(kaddr + block_off_start, 0, 2272 from - block_off_start); 2273 flush_dcache_page(page); 2274 kunmap_atomic(kaddr, KM_USER0); 2275 } 2276 if ((em->block_start != EXTENT_MAP_HOLE && 2277 em->block_start != EXTENT_MAP_INLINE) && 2278 !isnew && !PageUptodate(page) && 2279 (block_off_end > to || block_off_start < from) && 2280 !test_range_bit(tree, block_start, cur_end, 2281 EXTENT_UPTODATE, 1)) { 2282 u64 sector; 2283 u64 extent_offset = block_start - em->start; 2284 size_t iosize; 2285 sector = (em->block_start + extent_offset) >> 9; 2286 iosize = (cur_end - block_start + blocksize) & 2287 ~((u64)blocksize - 1); 2288 /* 2289 * we've already got the extent locked, but we 2290 * need to split the state such that our end_bio 2291 * handler can clear the lock. 2292 */ 2293 set_extent_bit(tree, block_start, 2294 block_start + iosize - 1, 2295 EXTENT_LOCKED, 0, NULL, GFP_NOFS); 2296 ret = submit_extent_page(READ, tree, page, 2297 sector, iosize, page_offset, em->bdev, 2298 NULL, 1, 2299 end_bio_extent_preparewrite); 2300 iocount++; 2301 block_start = block_start + iosize; 2302 } else { 2303 set_extent_uptodate(tree, block_start, cur_end, 2304 GFP_NOFS); 2305 unlock_extent(tree, block_start, cur_end, GFP_NOFS); 2306 block_start = cur_end + 1; 2307 } 2308 page_offset = block_start & (PAGE_CACHE_SIZE - 1); 2309 free_extent_map(em); 2310 } 2311 if (iocount) { 2312 wait_extent_bit(tree, orig_block_start, 2313 block_end, EXTENT_LOCKED); 2314 } 2315 check_page_uptodate(tree, page); 2316 err: 2317 /* FIXME, zero out newly allocated blocks on error */ 2318 return err; 2319 } 2320 EXPORT_SYMBOL(extent_prepare_write); 2321 2322 /* 2323 * a helper for releasepage. As long as there are no locked extents 2324 * in the range corresponding to the page, both state records and extent 2325 * map records are removed 2326 */ 2327 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) 2328 { 2329 struct extent_map *em; 2330 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 2331 u64 end = start + PAGE_CACHE_SIZE - 1; 2332 u64 orig_start = start; 2333 int ret = 1; 2334 2335 while (start <= end) { 2336 em = lookup_extent_mapping(tree, start, end); 2337 if (!em || IS_ERR(em)) 2338 break; 2339 if (!test_range_bit(tree, em->start, em->end, 2340 EXTENT_LOCKED, 0)) { 2341 remove_extent_mapping(tree, em); 2342 /* once for the rb tree */ 2343 free_extent_map(em); 2344 } 2345 start = em->end + 1; 2346 /* once for us */ 2347 free_extent_map(em); 2348 } 2349 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) 2350 ret = 0; 2351 else 2352 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, 2353 1, 1, GFP_NOFS); 2354 return ret; 2355 } 2356 EXPORT_SYMBOL(try_release_extent_mapping); 2357 2358 sector_t extent_bmap(struct address_space *mapping, sector_t iblock, 2359 get_extent_t *get_extent) 2360 { 2361 struct inode *inode = mapping->host; 2362 u64 start = iblock << inode->i_blkbits; 2363 u64 end = start + (1 << inode->i_blkbits) - 1; 2364 sector_t sector = 0; 2365 struct extent_map *em; 2366 2367 em = get_extent(inode, NULL, 0, start, end, 0); 2368 if (!em || IS_ERR(em)) 2369 return 0; 2370 2371 if (em->block_start == EXTENT_MAP_INLINE || 2372 em->block_start == EXTENT_MAP_HOLE) 2373 goto out; 2374 2375 sector = (em->block_start + start - em->start) >> inode->i_blkbits; 2376 out: 2377 free_extent_map(em); 2378 return sector; 2379 } 2380 2381 static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb) 2382 { 2383 if (list_empty(&eb->lru)) { 2384 extent_buffer_get(eb); 2385 list_add(&eb->lru, &tree->buffer_lru); 2386 tree->lru_size++; 2387 if (tree->lru_size >= BUFFER_LRU_MAX) { 2388 struct extent_buffer *rm; 2389 rm = list_entry(tree->buffer_lru.prev, 2390 struct extent_buffer, lru); 2391 tree->lru_size--; 2392 list_del_init(&rm->lru); 2393 free_extent_buffer(rm); 2394 } 2395 } else 2396 list_move(&eb->lru, &tree->buffer_lru); 2397 return 0; 2398 } 2399 static struct extent_buffer *find_lru(struct extent_map_tree *tree, 2400 u64 start, unsigned long len) 2401 { 2402 struct list_head *lru = &tree->buffer_lru; 2403 struct list_head *cur = lru->next; 2404 struct extent_buffer *eb; 2405 2406 if (list_empty(lru)) 2407 return NULL; 2408 2409 do { 2410 eb = list_entry(cur, struct extent_buffer, lru); 2411 if (eb->start == start && eb->len == len) { 2412 extent_buffer_get(eb); 2413 return eb; 2414 } 2415 cur = cur->next; 2416 } while (cur != lru); 2417 return NULL; 2418 } 2419 2420 static inline unsigned long num_extent_pages(u64 start, u64 len) 2421 { 2422 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - 2423 (start >> PAGE_CACHE_SHIFT); 2424 } 2425 2426 static inline struct page *extent_buffer_page(struct extent_buffer *eb, 2427 unsigned long i) 2428 { 2429 struct page *p; 2430 struct address_space *mapping; 2431 2432 if (i == 0) 2433 return eb->first_page; 2434 i += eb->start >> PAGE_CACHE_SHIFT; 2435 mapping = eb->first_page->mapping; 2436 read_lock_irq(&mapping->tree_lock); 2437 p = radix_tree_lookup(&mapping->page_tree, i); 2438 read_unlock_irq(&mapping->tree_lock); 2439 return p; 2440 } 2441 2442 static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, 2443 u64 start, 2444 unsigned long len, 2445 gfp_t mask) 2446 { 2447 struct extent_buffer *eb = NULL; 2448 2449 spin_lock(&tree->lru_lock); 2450 eb = find_lru(tree, start, len); 2451 spin_unlock(&tree->lru_lock); 2452 if (eb) { 2453 return eb; 2454 } 2455 2456 eb = kmem_cache_zalloc(extent_buffer_cache, mask); 2457 INIT_LIST_HEAD(&eb->lru); 2458 eb->start = start; 2459 eb->len = len; 2460 atomic_set(&eb->refs, 1); 2461 2462 return eb; 2463 } 2464 2465 static void __free_extent_buffer(struct extent_buffer *eb) 2466 { 2467 kmem_cache_free(extent_buffer_cache, eb); 2468 } 2469 2470 struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 2471 u64 start, unsigned long len, 2472 struct page *page0, 2473 gfp_t mask) 2474 { 2475 unsigned long num_pages = num_extent_pages(start, len); 2476 unsigned long i; 2477 unsigned long index = start >> PAGE_CACHE_SHIFT; 2478 struct extent_buffer *eb; 2479 struct page *p; 2480 struct address_space *mapping = tree->mapping; 2481 int uptodate = 1; 2482 2483 eb = __alloc_extent_buffer(tree, start, len, mask); 2484 if (!eb || IS_ERR(eb)) 2485 return NULL; 2486 2487 if (eb->flags & EXTENT_BUFFER_FILLED) 2488 goto lru_add; 2489 2490 if (page0) { 2491 eb->first_page = page0; 2492 i = 1; 2493 index++; 2494 page_cache_get(page0); 2495 mark_page_accessed(page0); 2496 set_page_extent_mapped(page0); 2497 WARN_ON(!PageUptodate(page0)); 2498 set_page_extent_head(page0, len); 2499 } else { 2500 i = 0; 2501 } 2502 for (; i < num_pages; i++, index++) { 2503 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM); 2504 if (!p) { 2505 WARN_ON(1); 2506 goto fail; 2507 } 2508 set_page_extent_mapped(p); 2509 mark_page_accessed(p); 2510 if (i == 0) { 2511 eb->first_page = p; 2512 set_page_extent_head(p, len); 2513 } else { 2514 set_page_private(p, EXTENT_PAGE_PRIVATE); 2515 } 2516 if (!PageUptodate(p)) 2517 uptodate = 0; 2518 unlock_page(p); 2519 } 2520 if (uptodate) 2521 eb->flags |= EXTENT_UPTODATE; 2522 eb->flags |= EXTENT_BUFFER_FILLED; 2523 2524 lru_add: 2525 spin_lock(&tree->lru_lock); 2526 add_lru(tree, eb); 2527 spin_unlock(&tree->lru_lock); 2528 return eb; 2529 2530 fail: 2531 spin_lock(&tree->lru_lock); 2532 list_del_init(&eb->lru); 2533 spin_unlock(&tree->lru_lock); 2534 if (!atomic_dec_and_test(&eb->refs)) 2535 return NULL; 2536 for (index = 1; index < i; index++) { 2537 page_cache_release(extent_buffer_page(eb, index)); 2538 } 2539 if (i > 0) 2540 page_cache_release(extent_buffer_page(eb, 0)); 2541 __free_extent_buffer(eb); 2542 return NULL; 2543 } 2544 EXPORT_SYMBOL(alloc_extent_buffer); 2545 2546 struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 2547 u64 start, unsigned long len, 2548 gfp_t mask) 2549 { 2550 unsigned long num_pages = num_extent_pages(start, len); 2551 unsigned long i; 2552 unsigned long index = start >> PAGE_CACHE_SHIFT; 2553 struct extent_buffer *eb; 2554 struct page *p; 2555 struct address_space *mapping = tree->mapping; 2556 int uptodate = 1; 2557 2558 eb = __alloc_extent_buffer(tree, start, len, mask); 2559 if (!eb || IS_ERR(eb)) 2560 return NULL; 2561 2562 if (eb->flags & EXTENT_BUFFER_FILLED) 2563 goto lru_add; 2564 2565 for (i = 0; i < num_pages; i++, index++) { 2566 p = find_lock_page(mapping, index); 2567 if (!p) { 2568 goto fail; 2569 } 2570 set_page_extent_mapped(p); 2571 mark_page_accessed(p); 2572 2573 if (i == 0) { 2574 eb->first_page = p; 2575 set_page_extent_head(p, len); 2576 } else { 2577 set_page_private(p, EXTENT_PAGE_PRIVATE); 2578 } 2579 2580 if (!PageUptodate(p)) 2581 uptodate = 0; 2582 unlock_page(p); 2583 } 2584 if (uptodate) 2585 eb->flags |= EXTENT_UPTODATE; 2586 eb->flags |= EXTENT_BUFFER_FILLED; 2587 2588 lru_add: 2589 spin_lock(&tree->lru_lock); 2590 add_lru(tree, eb); 2591 spin_unlock(&tree->lru_lock); 2592 return eb; 2593 fail: 2594 spin_lock(&tree->lru_lock); 2595 list_del_init(&eb->lru); 2596 spin_unlock(&tree->lru_lock); 2597 if (!atomic_dec_and_test(&eb->refs)) 2598 return NULL; 2599 for (index = 1; index < i; index++) { 2600 page_cache_release(extent_buffer_page(eb, index)); 2601 } 2602 if (i > 0) 2603 page_cache_release(extent_buffer_page(eb, 0)); 2604 __free_extent_buffer(eb); 2605 return NULL; 2606 } 2607 EXPORT_SYMBOL(find_extent_buffer); 2608 2609 void free_extent_buffer(struct extent_buffer *eb) 2610 { 2611 unsigned long i; 2612 unsigned long num_pages; 2613 2614 if (!eb) 2615 return; 2616 2617 if (!atomic_dec_and_test(&eb->refs)) 2618 return; 2619 2620 WARN_ON(!list_empty(&eb->lru)); 2621 num_pages = num_extent_pages(eb->start, eb->len); 2622 2623 for (i = 1; i < num_pages; i++) { 2624 page_cache_release(extent_buffer_page(eb, i)); 2625 } 2626 page_cache_release(extent_buffer_page(eb, 0)); 2627 __free_extent_buffer(eb); 2628 } 2629 EXPORT_SYMBOL(free_extent_buffer); 2630 2631 int clear_extent_buffer_dirty(struct extent_map_tree *tree, 2632 struct extent_buffer *eb) 2633 { 2634 int set; 2635 unsigned long i; 2636 unsigned long num_pages; 2637 struct page *page; 2638 2639 u64 start = eb->start; 2640 u64 end = start + eb->len - 1; 2641 2642 set = clear_extent_dirty(tree, start, end, GFP_NOFS); 2643 num_pages = num_extent_pages(eb->start, eb->len); 2644 2645 for (i = 0; i < num_pages; i++) { 2646 page = extent_buffer_page(eb, i); 2647 lock_page(page); 2648 if (i == 0) 2649 set_page_extent_head(page, eb->len); 2650 else 2651 set_page_private(page, EXTENT_PAGE_PRIVATE); 2652 2653 /* 2654 * if we're on the last page or the first page and the 2655 * block isn't aligned on a page boundary, do extra checks 2656 * to make sure we don't clean page that is partially dirty 2657 */ 2658 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2659 ((i == num_pages - 1) && 2660 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2661 start = (u64)page->index << PAGE_CACHE_SHIFT; 2662 end = start + PAGE_CACHE_SIZE - 1; 2663 if (test_range_bit(tree, start, end, 2664 EXTENT_DIRTY, 0)) { 2665 unlock_page(page); 2666 continue; 2667 } 2668 } 2669 clear_page_dirty_for_io(page); 2670 write_lock_irq(&page->mapping->tree_lock); 2671 if (!PageDirty(page)) { 2672 radix_tree_tag_clear(&page->mapping->page_tree, 2673 page_index(page), 2674 PAGECACHE_TAG_DIRTY); 2675 } 2676 write_unlock_irq(&page->mapping->tree_lock); 2677 unlock_page(page); 2678 } 2679 return 0; 2680 } 2681 EXPORT_SYMBOL(clear_extent_buffer_dirty); 2682 2683 int wait_on_extent_buffer_writeback(struct extent_map_tree *tree, 2684 struct extent_buffer *eb) 2685 { 2686 return wait_on_extent_writeback(tree, eb->start, 2687 eb->start + eb->len - 1); 2688 } 2689 EXPORT_SYMBOL(wait_on_extent_buffer_writeback); 2690 2691 int set_extent_buffer_dirty(struct extent_map_tree *tree, 2692 struct extent_buffer *eb) 2693 { 2694 unsigned long i; 2695 unsigned long num_pages; 2696 2697 num_pages = num_extent_pages(eb->start, eb->len); 2698 for (i = 0; i < num_pages; i++) { 2699 struct page *page = extent_buffer_page(eb, i); 2700 /* writepage may need to do something special for the 2701 * first page, we have to make sure page->private is 2702 * properly set. releasepage may drop page->private 2703 * on us if the page isn't already dirty. 2704 */ 2705 if (i == 0) { 2706 lock_page(page); 2707 set_page_extent_head(page, eb->len); 2708 } else if (PagePrivate(page) && 2709 page->private != EXTENT_PAGE_PRIVATE) { 2710 lock_page(page); 2711 set_page_extent_mapped(page); 2712 unlock_page(page); 2713 } 2714 __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); 2715 if (i == 0) 2716 unlock_page(page); 2717 } 2718 return set_extent_dirty(tree, eb->start, 2719 eb->start + eb->len - 1, GFP_NOFS); 2720 } 2721 EXPORT_SYMBOL(set_extent_buffer_dirty); 2722 2723 int set_extent_buffer_uptodate(struct extent_map_tree *tree, 2724 struct extent_buffer *eb) 2725 { 2726 unsigned long i; 2727 struct page *page; 2728 unsigned long num_pages; 2729 2730 num_pages = num_extent_pages(eb->start, eb->len); 2731 2732 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, 2733 GFP_NOFS); 2734 for (i = 0; i < num_pages; i++) { 2735 page = extent_buffer_page(eb, i); 2736 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2737 ((i == num_pages - 1) && 2738 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2739 check_page_uptodate(tree, page); 2740 continue; 2741 } 2742 SetPageUptodate(page); 2743 } 2744 return 0; 2745 } 2746 EXPORT_SYMBOL(set_extent_buffer_uptodate); 2747 2748 int extent_buffer_uptodate(struct extent_map_tree *tree, 2749 struct extent_buffer *eb) 2750 { 2751 if (eb->flags & EXTENT_UPTODATE) 2752 return 1; 2753 return test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2754 EXTENT_UPTODATE, 1); 2755 } 2756 EXPORT_SYMBOL(extent_buffer_uptodate); 2757 2758 int read_extent_buffer_pages(struct extent_map_tree *tree, 2759 struct extent_buffer *eb, 2760 u64 start, 2761 int wait) 2762 { 2763 unsigned long i; 2764 unsigned long start_i; 2765 struct page *page; 2766 int err; 2767 int ret = 0; 2768 unsigned long num_pages; 2769 2770 if (eb->flags & EXTENT_UPTODATE) 2771 return 0; 2772 2773 if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2774 EXTENT_UPTODATE, 1)) { 2775 return 0; 2776 } 2777 2778 if (start) { 2779 WARN_ON(start < eb->start); 2780 start_i = (start >> PAGE_CACHE_SHIFT) - 2781 (eb->start >> PAGE_CACHE_SHIFT); 2782 } else { 2783 start_i = 0; 2784 } 2785 2786 num_pages = num_extent_pages(eb->start, eb->len); 2787 for (i = start_i; i < num_pages; i++) { 2788 page = extent_buffer_page(eb, i); 2789 if (PageUptodate(page)) { 2790 continue; 2791 } 2792 if (!wait) { 2793 if (TestSetPageLocked(page)) { 2794 continue; 2795 } 2796 } else { 2797 lock_page(page); 2798 } 2799 if (!PageUptodate(page)) { 2800 err = page->mapping->a_ops->readpage(NULL, page); 2801 if (err) { 2802 ret = err; 2803 } 2804 } else { 2805 unlock_page(page); 2806 } 2807 } 2808 2809 if (ret || !wait) { 2810 return ret; 2811 } 2812 2813 for (i = start_i; i < num_pages; i++) { 2814 page = extent_buffer_page(eb, i); 2815 wait_on_page_locked(page); 2816 if (!PageUptodate(page)) { 2817 ret = -EIO; 2818 } 2819 } 2820 if (!ret) 2821 eb->flags |= EXTENT_UPTODATE; 2822 return ret; 2823 } 2824 EXPORT_SYMBOL(read_extent_buffer_pages); 2825 2826 void read_extent_buffer(struct extent_buffer *eb, void *dstv, 2827 unsigned long start, 2828 unsigned long len) 2829 { 2830 size_t cur; 2831 size_t offset; 2832 struct page *page; 2833 char *kaddr; 2834 char *dst = (char *)dstv; 2835 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2836 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2837 unsigned long num_pages = num_extent_pages(eb->start, eb->len); 2838 2839 WARN_ON(start > eb->len); 2840 WARN_ON(start + len > eb->start + eb->len); 2841 2842 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2843 2844 while(len > 0) { 2845 page = extent_buffer_page(eb, i); 2846 if (!PageUptodate(page)) { 2847 printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); 2848 WARN_ON(1); 2849 } 2850 WARN_ON(!PageUptodate(page)); 2851 2852 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2853 kaddr = kmap_atomic(page, KM_USER1); 2854 memcpy(dst, kaddr + offset, cur); 2855 kunmap_atomic(kaddr, KM_USER1); 2856 2857 dst += cur; 2858 len -= cur; 2859 offset = 0; 2860 i++; 2861 } 2862 } 2863 EXPORT_SYMBOL(read_extent_buffer); 2864 2865 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, 2866 unsigned long min_len, char **token, char **map, 2867 unsigned long *map_start, 2868 unsigned long *map_len, int km) 2869 { 2870 size_t offset = start & (PAGE_CACHE_SIZE - 1); 2871 char *kaddr; 2872 struct page *p; 2873 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2874 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2875 unsigned long end_i = (start_offset + start + min_len - 1) >> 2876 PAGE_CACHE_SHIFT; 2877 2878 if (i != end_i) 2879 return -EINVAL; 2880 2881 if (i == 0) { 2882 offset = start_offset; 2883 *map_start = 0; 2884 } else { 2885 offset = 0; 2886 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset; 2887 } 2888 if (start + min_len > eb->len) { 2889 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); 2890 WARN_ON(1); 2891 } 2892 2893 p = extent_buffer_page(eb, i); 2894 WARN_ON(!PageUptodate(p)); 2895 kaddr = kmap_atomic(p, km); 2896 *token = kaddr; 2897 *map = kaddr + offset; 2898 *map_len = PAGE_CACHE_SIZE - offset; 2899 return 0; 2900 } 2901 EXPORT_SYMBOL(map_private_extent_buffer); 2902 2903 int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 2904 unsigned long min_len, 2905 char **token, char **map, 2906 unsigned long *map_start, 2907 unsigned long *map_len, int km) 2908 { 2909 int err; 2910 int save = 0; 2911 if (eb->map_token) { 2912 unmap_extent_buffer(eb, eb->map_token, km); 2913 eb->map_token = NULL; 2914 save = 1; 2915 } 2916 err = map_private_extent_buffer(eb, start, min_len, token, map, 2917 map_start, map_len, km); 2918 if (!err && save) { 2919 eb->map_token = *token; 2920 eb->kaddr = *map; 2921 eb->map_start = *map_start; 2922 eb->map_len = *map_len; 2923 } 2924 return err; 2925 } 2926 EXPORT_SYMBOL(map_extent_buffer); 2927 2928 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) 2929 { 2930 kunmap_atomic(token, km); 2931 } 2932 EXPORT_SYMBOL(unmap_extent_buffer); 2933 2934 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 2935 unsigned long start, 2936 unsigned long len) 2937 { 2938 size_t cur; 2939 size_t offset; 2940 struct page *page; 2941 char *kaddr; 2942 char *ptr = (char *)ptrv; 2943 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2944 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2945 int ret = 0; 2946 2947 WARN_ON(start > eb->len); 2948 WARN_ON(start + len > eb->start + eb->len); 2949 2950 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2951 2952 while(len > 0) { 2953 page = extent_buffer_page(eb, i); 2954 WARN_ON(!PageUptodate(page)); 2955 2956 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2957 2958 kaddr = kmap_atomic(page, KM_USER0); 2959 ret = memcmp(ptr, kaddr + offset, cur); 2960 kunmap_atomic(kaddr, KM_USER0); 2961 if (ret) 2962 break; 2963 2964 ptr += cur; 2965 len -= cur; 2966 offset = 0; 2967 i++; 2968 } 2969 return ret; 2970 } 2971 EXPORT_SYMBOL(memcmp_extent_buffer); 2972 2973 void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 2974 unsigned long start, unsigned long len) 2975 { 2976 size_t cur; 2977 size_t offset; 2978 struct page *page; 2979 char *kaddr; 2980 char *src = (char *)srcv; 2981 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2982 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2983 2984 WARN_ON(start > eb->len); 2985 WARN_ON(start + len > eb->start + eb->len); 2986 2987 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2988 2989 while(len > 0) { 2990 page = extent_buffer_page(eb, i); 2991 WARN_ON(!PageUptodate(page)); 2992 2993 cur = min(len, PAGE_CACHE_SIZE - offset); 2994 kaddr = kmap_atomic(page, KM_USER1); 2995 memcpy(kaddr + offset, src, cur); 2996 kunmap_atomic(kaddr, KM_USER1); 2997 2998 src += cur; 2999 len -= cur; 3000 offset = 0; 3001 i++; 3002 } 3003 } 3004 EXPORT_SYMBOL(write_extent_buffer); 3005 3006 void memset_extent_buffer(struct extent_buffer *eb, char c, 3007 unsigned long start, unsigned long len) 3008 { 3009 size_t cur; 3010 size_t offset; 3011 struct page *page; 3012 char *kaddr; 3013 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 3014 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 3015 3016 WARN_ON(start > eb->len); 3017 WARN_ON(start + len > eb->start + eb->len); 3018 3019 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 3020 3021 while(len > 0) { 3022 page = extent_buffer_page(eb, i); 3023 WARN_ON(!PageUptodate(page)); 3024 3025 cur = min(len, PAGE_CACHE_SIZE - offset); 3026 kaddr = kmap_atomic(page, KM_USER0); 3027 memset(kaddr + offset, c, cur); 3028 kunmap_atomic(kaddr, KM_USER0); 3029 3030 len -= cur; 3031 offset = 0; 3032 i++; 3033 } 3034 } 3035 EXPORT_SYMBOL(memset_extent_buffer); 3036 3037 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 3038 unsigned long dst_offset, unsigned long src_offset, 3039 unsigned long len) 3040 { 3041 u64 dst_len = dst->len; 3042 size_t cur; 3043 size_t offset; 3044 struct page *page; 3045 char *kaddr; 3046 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 3047 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 3048 3049 WARN_ON(src->len != dst_len); 3050 3051 offset = (start_offset + dst_offset) & 3052 ((unsigned long)PAGE_CACHE_SIZE - 1); 3053 3054 while(len > 0) { 3055 page = extent_buffer_page(dst, i); 3056 WARN_ON(!PageUptodate(page)); 3057 3058 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset)); 3059 3060 kaddr = kmap_atomic(page, KM_USER0); 3061 read_extent_buffer(src, kaddr + offset, src_offset, cur); 3062 kunmap_atomic(kaddr, KM_USER0); 3063 3064 src_offset += cur; 3065 len -= cur; 3066 offset = 0; 3067 i++; 3068 } 3069 } 3070 EXPORT_SYMBOL(copy_extent_buffer); 3071 3072 static void move_pages(struct page *dst_page, struct page *src_page, 3073 unsigned long dst_off, unsigned long src_off, 3074 unsigned long len) 3075 { 3076 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 3077 if (dst_page == src_page) { 3078 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len); 3079 } else { 3080 char *src_kaddr = kmap_atomic(src_page, KM_USER1); 3081 char *p = dst_kaddr + dst_off + len; 3082 char *s = src_kaddr + src_off + len; 3083 3084 while (len--) 3085 *--p = *--s; 3086 3087 kunmap_atomic(src_kaddr, KM_USER1); 3088 } 3089 kunmap_atomic(dst_kaddr, KM_USER0); 3090 } 3091 3092 static void copy_pages(struct page *dst_page, struct page *src_page, 3093 unsigned long dst_off, unsigned long src_off, 3094 unsigned long len) 3095 { 3096 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 3097 char *src_kaddr; 3098 3099 if (dst_page != src_page) 3100 src_kaddr = kmap_atomic(src_page, KM_USER1); 3101 else 3102 src_kaddr = dst_kaddr; 3103 3104 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); 3105 kunmap_atomic(dst_kaddr, KM_USER0); 3106 if (dst_page != src_page) 3107 kunmap_atomic(src_kaddr, KM_USER1); 3108 } 3109 3110 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 3111 unsigned long src_offset, unsigned long len) 3112 { 3113 size_t cur; 3114 size_t dst_off_in_page; 3115 size_t src_off_in_page; 3116 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 3117 unsigned long dst_i; 3118 unsigned long src_i; 3119 3120 if (src_offset + len > dst->len) { 3121 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 3122 src_offset, len, dst->len); 3123 BUG_ON(1); 3124 } 3125 if (dst_offset + len > dst->len) { 3126 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 3127 dst_offset, len, dst->len); 3128 BUG_ON(1); 3129 } 3130 3131 while(len > 0) { 3132 dst_off_in_page = (start_offset + dst_offset) & 3133 ((unsigned long)PAGE_CACHE_SIZE - 1); 3134 src_off_in_page = (start_offset + src_offset) & 3135 ((unsigned long)PAGE_CACHE_SIZE - 1); 3136 3137 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 3138 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT; 3139 3140 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - 3141 src_off_in_page)); 3142 cur = min_t(unsigned long, cur, 3143 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page)); 3144 3145 copy_pages(extent_buffer_page(dst, dst_i), 3146 extent_buffer_page(dst, src_i), 3147 dst_off_in_page, src_off_in_page, cur); 3148 3149 src_offset += cur; 3150 dst_offset += cur; 3151 len -= cur; 3152 } 3153 } 3154 EXPORT_SYMBOL(memcpy_extent_buffer); 3155 3156 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 3157 unsigned long src_offset, unsigned long len) 3158 { 3159 size_t cur; 3160 size_t dst_off_in_page; 3161 size_t src_off_in_page; 3162 unsigned long dst_end = dst_offset + len - 1; 3163 unsigned long src_end = src_offset + len - 1; 3164 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 3165 unsigned long dst_i; 3166 unsigned long src_i; 3167 3168 if (src_offset + len > dst->len) { 3169 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 3170 src_offset, len, dst->len); 3171 BUG_ON(1); 3172 } 3173 if (dst_offset + len > dst->len) { 3174 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 3175 dst_offset, len, dst->len); 3176 BUG_ON(1); 3177 } 3178 if (dst_offset < src_offset) { 3179 memcpy_extent_buffer(dst, dst_offset, src_offset, len); 3180 return; 3181 } 3182 while(len > 0) { 3183 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT; 3184 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT; 3185 3186 dst_off_in_page = (start_offset + dst_end) & 3187 ((unsigned long)PAGE_CACHE_SIZE - 1); 3188 src_off_in_page = (start_offset + src_end) & 3189 ((unsigned long)PAGE_CACHE_SIZE - 1); 3190 3191 cur = min_t(unsigned long, len, src_off_in_page + 1); 3192 cur = min(cur, dst_off_in_page + 1); 3193 move_pages(extent_buffer_page(dst, dst_i), 3194 extent_buffer_page(dst, src_i), 3195 dst_off_in_page - cur + 1, 3196 src_off_in_page - cur + 1, cur); 3197 3198 dst_end -= cur; 3199 src_end -= cur; 3200 len -= cur; 3201 } 3202 } 3203 EXPORT_SYMBOL(memmove_extent_buffer); 3204