1 #include <linux/bitops.h> 2 #include <linux/slab.h> 3 #include <linux/bio.h> 4 #include <linux/mm.h> 5 #include <linux/gfp.h> 6 #include <linux/pagemap.h> 7 #include <linux/page-flags.h> 8 #include <linux/module.h> 9 #include <linux/spinlock.h> 10 #include <linux/blkdev.h> 11 #include <linux/swap.h> 12 #include <linux/version.h> 13 #include <linux/writeback.h> 14 #include <linux/pagevec.h> 15 #include "extent_map.h" 16 17 /* temporary define until extent_map moves out of btrfs */ 18 struct kmem_cache *btrfs_cache_create(const char *name, size_t size, 19 unsigned long extra_flags, 20 void (*ctor)(void *, struct kmem_cache *, 21 unsigned long)); 22 23 static struct kmem_cache *extent_map_cache; 24 static struct kmem_cache *extent_state_cache; 25 static struct kmem_cache *extent_buffer_cache; 26 27 static LIST_HEAD(buffers); 28 static LIST_HEAD(states); 29 30 static spinlock_t state_lock = SPIN_LOCK_UNLOCKED; 31 #define BUFFER_LRU_MAX 64 32 33 struct tree_entry { 34 u64 start; 35 u64 end; 36 int in_tree; 37 struct rb_node rb_node; 38 }; 39 40 struct extent_page_data { 41 struct bio *bio; 42 struct extent_map_tree *tree; 43 get_extent_t *get_extent; 44 }; 45 46 int __init extent_map_init(void) 47 { 48 extent_map_cache = btrfs_cache_create("extent_map", 49 sizeof(struct extent_map), 0, 50 NULL); 51 if (!extent_map_cache) 52 return -ENOMEM; 53 extent_state_cache = btrfs_cache_create("extent_state", 54 sizeof(struct extent_state), 0, 55 NULL); 56 if (!extent_state_cache) 57 goto free_map_cache; 58 extent_buffer_cache = btrfs_cache_create("extent_buffers", 59 sizeof(struct extent_buffer), 0, 60 NULL); 61 if (!extent_buffer_cache) 62 goto free_state_cache; 63 return 0; 64 65 free_state_cache: 66 kmem_cache_destroy(extent_state_cache); 67 free_map_cache: 68 kmem_cache_destroy(extent_map_cache); 69 return -ENOMEM; 70 } 71 72 void extent_map_exit(void) 73 { 74 struct extent_state *state; 75 76 while (!list_empty(&states)) { 77 state = list_entry(states.next, struct extent_state, list); 78 printk("state leak: start %Lu end %Lu state %lu in tree %d refs %d\n", state->start, state->end, state->state, state->in_tree, atomic_read(&state->refs)); 79 list_del(&state->list); 80 kmem_cache_free(extent_state_cache, state); 81 82 } 83 84 if (extent_map_cache) 85 kmem_cache_destroy(extent_map_cache); 86 if (extent_state_cache) 87 kmem_cache_destroy(extent_state_cache); 88 if (extent_buffer_cache) 89 kmem_cache_destroy(extent_buffer_cache); 90 } 91 92 void extent_map_tree_init(struct extent_map_tree *tree, 93 struct address_space *mapping, gfp_t mask) 94 { 95 tree->map.rb_node = NULL; 96 tree->state.rb_node = NULL; 97 tree->ops = NULL; 98 tree->dirty_bytes = 0; 99 rwlock_init(&tree->lock); 100 spin_lock_init(&tree->lru_lock); 101 tree->mapping = mapping; 102 INIT_LIST_HEAD(&tree->buffer_lru); 103 tree->lru_size = 0; 104 } 105 EXPORT_SYMBOL(extent_map_tree_init); 106 107 void extent_map_tree_empty_lru(struct extent_map_tree *tree) 108 { 109 struct extent_buffer *eb; 110 while(!list_empty(&tree->buffer_lru)) { 111 eb = list_entry(tree->buffer_lru.next, struct extent_buffer, 112 lru); 113 list_del_init(&eb->lru); 114 free_extent_buffer(eb); 115 } 116 } 117 EXPORT_SYMBOL(extent_map_tree_empty_lru); 118 119 struct extent_map *alloc_extent_map(gfp_t mask) 120 { 121 struct extent_map *em; 122 em = kmem_cache_alloc(extent_map_cache, mask); 123 if (!em || IS_ERR(em)) 124 return em; 125 em->in_tree = 0; 126 atomic_set(&em->refs, 1); 127 return em; 128 } 129 EXPORT_SYMBOL(alloc_extent_map); 130 131 void free_extent_map(struct extent_map *em) 132 { 133 if (!em) 134 return; 135 if (atomic_dec_and_test(&em->refs)) { 136 WARN_ON(em->in_tree); 137 kmem_cache_free(extent_map_cache, em); 138 } 139 } 140 EXPORT_SYMBOL(free_extent_map); 141 142 143 struct extent_state *alloc_extent_state(gfp_t mask) 144 { 145 struct extent_state *state; 146 unsigned long flags; 147 148 state = kmem_cache_alloc(extent_state_cache, mask); 149 if (!state || IS_ERR(state)) 150 return state; 151 state->state = 0; 152 state->in_tree = 0; 153 state->private = 0; 154 155 spin_lock_irqsave(&state_lock, flags); 156 list_add(&state->list, &states); 157 spin_unlock_irqrestore(&state_lock, flags); 158 159 atomic_set(&state->refs, 1); 160 init_waitqueue_head(&state->wq); 161 return state; 162 } 163 EXPORT_SYMBOL(alloc_extent_state); 164 165 void free_extent_state(struct extent_state *state) 166 { 167 unsigned long flags; 168 if (!state) 169 return; 170 if (atomic_dec_and_test(&state->refs)) { 171 WARN_ON(state->in_tree); 172 spin_lock_irqsave(&state_lock, flags); 173 list_del(&state->list); 174 spin_unlock_irqrestore(&state_lock, flags); 175 kmem_cache_free(extent_state_cache, state); 176 } 177 } 178 EXPORT_SYMBOL(free_extent_state); 179 180 static struct rb_node *tree_insert(struct rb_root *root, u64 offset, 181 struct rb_node *node) 182 { 183 struct rb_node ** p = &root->rb_node; 184 struct rb_node * parent = NULL; 185 struct tree_entry *entry; 186 187 while(*p) { 188 parent = *p; 189 entry = rb_entry(parent, struct tree_entry, rb_node); 190 191 if (offset < entry->start) 192 p = &(*p)->rb_left; 193 else if (offset > entry->end) 194 p = &(*p)->rb_right; 195 else 196 return parent; 197 } 198 199 entry = rb_entry(node, struct tree_entry, rb_node); 200 entry->in_tree = 1; 201 rb_link_node(node, parent, p); 202 rb_insert_color(node, root); 203 return NULL; 204 } 205 206 static struct rb_node *__tree_search(struct rb_root *root, u64 offset, 207 struct rb_node **prev_ret) 208 { 209 struct rb_node * n = root->rb_node; 210 struct rb_node *prev = NULL; 211 struct tree_entry *entry; 212 struct tree_entry *prev_entry = NULL; 213 214 while(n) { 215 entry = rb_entry(n, struct tree_entry, rb_node); 216 prev = n; 217 prev_entry = entry; 218 219 if (offset < entry->start) 220 n = n->rb_left; 221 else if (offset > entry->end) 222 n = n->rb_right; 223 else 224 return n; 225 } 226 if (!prev_ret) 227 return NULL; 228 while(prev && offset > prev_entry->end) { 229 prev = rb_next(prev); 230 prev_entry = rb_entry(prev, struct tree_entry, rb_node); 231 } 232 *prev_ret = prev; 233 return NULL; 234 } 235 236 static inline struct rb_node *tree_search(struct rb_root *root, u64 offset) 237 { 238 struct rb_node *prev; 239 struct rb_node *ret; 240 ret = __tree_search(root, offset, &prev); 241 if (!ret) 242 return prev; 243 return ret; 244 } 245 246 static int tree_delete(struct rb_root *root, u64 offset) 247 { 248 struct rb_node *node; 249 struct tree_entry *entry; 250 251 node = __tree_search(root, offset, NULL); 252 if (!node) 253 return -ENOENT; 254 entry = rb_entry(node, struct tree_entry, rb_node); 255 entry->in_tree = 0; 256 rb_erase(node, root); 257 return 0; 258 } 259 260 /* 261 * add_extent_mapping tries a simple backward merge with existing 262 * mappings. The extent_map struct passed in will be inserted into 263 * the tree directly (no copies made, just a reference taken). 264 */ 265 int add_extent_mapping(struct extent_map_tree *tree, 266 struct extent_map *em) 267 { 268 int ret = 0; 269 struct extent_map *prev = NULL; 270 struct rb_node *rb; 271 272 write_lock_irq(&tree->lock); 273 rb = tree_insert(&tree->map, em->end, &em->rb_node); 274 if (rb) { 275 prev = rb_entry(rb, struct extent_map, rb_node); 276 printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev->start, prev->end, em->start, em->end); 277 ret = -EEXIST; 278 goto out; 279 } 280 atomic_inc(&em->refs); 281 if (em->start != 0) { 282 rb = rb_prev(&em->rb_node); 283 if (rb) 284 prev = rb_entry(rb, struct extent_map, rb_node); 285 if (prev && prev->end + 1 == em->start && 286 ((em->block_start == EXTENT_MAP_HOLE && 287 prev->block_start == EXTENT_MAP_HOLE) || 288 (em->block_start == EXTENT_MAP_INLINE && 289 prev->block_start == EXTENT_MAP_INLINE) || 290 (em->block_start == EXTENT_MAP_DELALLOC && 291 prev->block_start == EXTENT_MAP_DELALLOC) || 292 (em->block_start < EXTENT_MAP_DELALLOC - 1 && 293 em->block_start == prev->block_end + 1))) { 294 em->start = prev->start; 295 em->block_start = prev->block_start; 296 rb_erase(&prev->rb_node, &tree->map); 297 prev->in_tree = 0; 298 free_extent_map(prev); 299 } 300 } 301 out: 302 write_unlock_irq(&tree->lock); 303 return ret; 304 } 305 EXPORT_SYMBOL(add_extent_mapping); 306 307 /* 308 * lookup_extent_mapping returns the first extent_map struct in the 309 * tree that intersects the [start, end] (inclusive) range. There may 310 * be additional objects in the tree that intersect, so check the object 311 * returned carefully to make sure you don't need additional lookups. 312 */ 313 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, 314 u64 start, u64 end) 315 { 316 struct extent_map *em; 317 struct rb_node *rb_node; 318 319 read_lock_irq(&tree->lock); 320 rb_node = tree_search(&tree->map, start); 321 if (!rb_node) { 322 em = NULL; 323 goto out; 324 } 325 if (IS_ERR(rb_node)) { 326 em = ERR_PTR(PTR_ERR(rb_node)); 327 goto out; 328 } 329 em = rb_entry(rb_node, struct extent_map, rb_node); 330 if (em->end < start || em->start > end) { 331 em = NULL; 332 goto out; 333 } 334 atomic_inc(&em->refs); 335 out: 336 read_unlock_irq(&tree->lock); 337 return em; 338 } 339 EXPORT_SYMBOL(lookup_extent_mapping); 340 341 /* 342 * removes an extent_map struct from the tree. No reference counts are 343 * dropped, and no checks are done to see if the range is in use 344 */ 345 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) 346 { 347 int ret; 348 349 write_lock_irq(&tree->lock); 350 ret = tree_delete(&tree->map, em->end); 351 write_unlock_irq(&tree->lock); 352 return ret; 353 } 354 EXPORT_SYMBOL(remove_extent_mapping); 355 356 /* 357 * utility function to look for merge candidates inside a given range. 358 * Any extents with matching state are merged together into a single 359 * extent in the tree. Extents with EXTENT_IO in their state field 360 * are not merged because the end_io handlers need to be able to do 361 * operations on them without sleeping (or doing allocations/splits). 362 * 363 * This should be called with the tree lock held. 364 */ 365 static int merge_state(struct extent_map_tree *tree, 366 struct extent_state *state) 367 { 368 struct extent_state *other; 369 struct rb_node *other_node; 370 371 if (state->state & EXTENT_IOBITS) 372 return 0; 373 374 other_node = rb_prev(&state->rb_node); 375 if (other_node) { 376 other = rb_entry(other_node, struct extent_state, rb_node); 377 if (other->end == state->start - 1 && 378 other->state == state->state) { 379 state->start = other->start; 380 other->in_tree = 0; 381 rb_erase(&other->rb_node, &tree->state); 382 free_extent_state(other); 383 } 384 } 385 other_node = rb_next(&state->rb_node); 386 if (other_node) { 387 other = rb_entry(other_node, struct extent_state, rb_node); 388 if (other->start == state->end + 1 && 389 other->state == state->state) { 390 other->start = state->start; 391 state->in_tree = 0; 392 rb_erase(&state->rb_node, &tree->state); 393 free_extent_state(state); 394 } 395 } 396 return 0; 397 } 398 399 /* 400 * insert an extent_state struct into the tree. 'bits' are set on the 401 * struct before it is inserted. 402 * 403 * This may return -EEXIST if the extent is already there, in which case the 404 * state struct is freed. 405 * 406 * The tree lock is not taken internally. This is a utility function and 407 * probably isn't what you want to call (see set/clear_extent_bit). 408 */ 409 static int insert_state(struct extent_map_tree *tree, 410 struct extent_state *state, u64 start, u64 end, 411 int bits) 412 { 413 struct rb_node *node; 414 415 if (end < start) { 416 printk("end < start %Lu %Lu\n", end, start); 417 WARN_ON(1); 418 } 419 if (bits & EXTENT_DIRTY) 420 tree->dirty_bytes += end - start + 1; 421 state->state |= bits; 422 state->start = start; 423 state->end = end; 424 node = tree_insert(&tree->state, end, &state->rb_node); 425 if (node) { 426 struct extent_state *found; 427 found = rb_entry(node, struct extent_state, rb_node); 428 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end); 429 free_extent_state(state); 430 return -EEXIST; 431 } 432 merge_state(tree, state); 433 return 0; 434 } 435 436 /* 437 * split a given extent state struct in two, inserting the preallocated 438 * struct 'prealloc' as the newly created second half. 'split' indicates an 439 * offset inside 'orig' where it should be split. 440 * 441 * Before calling, 442 * the tree has 'orig' at [orig->start, orig->end]. After calling, there 443 * are two extent state structs in the tree: 444 * prealloc: [orig->start, split - 1] 445 * orig: [ split, orig->end ] 446 * 447 * The tree locks are not taken by this function. They need to be held 448 * by the caller. 449 */ 450 static int split_state(struct extent_map_tree *tree, struct extent_state *orig, 451 struct extent_state *prealloc, u64 split) 452 { 453 struct rb_node *node; 454 prealloc->start = orig->start; 455 prealloc->end = split - 1; 456 prealloc->state = orig->state; 457 orig->start = split; 458 459 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node); 460 if (node) { 461 struct extent_state *found; 462 found = rb_entry(node, struct extent_state, rb_node); 463 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end); 464 free_extent_state(prealloc); 465 return -EEXIST; 466 } 467 return 0; 468 } 469 470 /* 471 * utility function to clear some bits in an extent state struct. 472 * it will optionally wake up any one waiting on this state (wake == 1), or 473 * forcibly remove the state from the tree (delete == 1). 474 * 475 * If no bits are set on the state struct after clearing things, the 476 * struct is freed and removed from the tree 477 */ 478 static int clear_state_bit(struct extent_map_tree *tree, 479 struct extent_state *state, int bits, int wake, 480 int delete) 481 { 482 int ret = state->state & bits; 483 484 if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) { 485 u64 range = state->end - state->start + 1; 486 WARN_ON(range > tree->dirty_bytes); 487 tree->dirty_bytes -= range; 488 } 489 state->state &= ~bits; 490 if (wake) 491 wake_up(&state->wq); 492 if (delete || state->state == 0) { 493 if (state->in_tree) { 494 rb_erase(&state->rb_node, &tree->state); 495 state->in_tree = 0; 496 free_extent_state(state); 497 } else { 498 WARN_ON(1); 499 } 500 } else { 501 merge_state(tree, state); 502 } 503 return ret; 504 } 505 506 /* 507 * clear some bits on a range in the tree. This may require splitting 508 * or inserting elements in the tree, so the gfp mask is used to 509 * indicate which allocations or sleeping are allowed. 510 * 511 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove 512 * the given range from the tree regardless of state (ie for truncate). 513 * 514 * the range [start, end] is inclusive. 515 * 516 * This takes the tree lock, and returns < 0 on error, > 0 if any of the 517 * bits were already set, or zero if none of the bits were already set. 518 */ 519 int clear_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, 520 int bits, int wake, int delete, gfp_t mask) 521 { 522 struct extent_state *state; 523 struct extent_state *prealloc = NULL; 524 struct rb_node *node; 525 unsigned long flags; 526 int err; 527 int set = 0; 528 529 again: 530 if (!prealloc && (mask & __GFP_WAIT)) { 531 prealloc = alloc_extent_state(mask); 532 if (!prealloc) 533 return -ENOMEM; 534 } 535 536 write_lock_irqsave(&tree->lock, flags); 537 /* 538 * this search will find the extents that end after 539 * our range starts 540 */ 541 node = tree_search(&tree->state, start); 542 if (!node) 543 goto out; 544 state = rb_entry(node, struct extent_state, rb_node); 545 if (state->start > end) 546 goto out; 547 WARN_ON(state->end < start); 548 549 /* 550 * | ---- desired range ---- | 551 * | state | or 552 * | ------------- state -------------- | 553 * 554 * We need to split the extent we found, and may flip 555 * bits on second half. 556 * 557 * If the extent we found extends past our range, we 558 * just split and search again. It'll get split again 559 * the next time though. 560 * 561 * If the extent we found is inside our range, we clear 562 * the desired bit on it. 563 */ 564 565 if (state->start < start) { 566 err = split_state(tree, state, prealloc, start); 567 BUG_ON(err == -EEXIST); 568 prealloc = NULL; 569 if (err) 570 goto out; 571 if (state->end <= end) { 572 start = state->end + 1; 573 set |= clear_state_bit(tree, state, bits, 574 wake, delete); 575 } else { 576 start = state->start; 577 } 578 goto search_again; 579 } 580 /* 581 * | ---- desired range ---- | 582 * | state | 583 * We need to split the extent, and clear the bit 584 * on the first half 585 */ 586 if (state->start <= end && state->end > end) { 587 err = split_state(tree, state, prealloc, end + 1); 588 BUG_ON(err == -EEXIST); 589 590 if (wake) 591 wake_up(&state->wq); 592 set |= clear_state_bit(tree, prealloc, bits, 593 wake, delete); 594 prealloc = NULL; 595 goto out; 596 } 597 598 start = state->end + 1; 599 set |= clear_state_bit(tree, state, bits, wake, delete); 600 goto search_again; 601 602 out: 603 write_unlock_irqrestore(&tree->lock, flags); 604 if (prealloc) 605 free_extent_state(prealloc); 606 607 return set; 608 609 search_again: 610 if (start > end) 611 goto out; 612 write_unlock_irqrestore(&tree->lock, flags); 613 if (mask & __GFP_WAIT) 614 cond_resched(); 615 goto again; 616 } 617 EXPORT_SYMBOL(clear_extent_bit); 618 619 static int wait_on_state(struct extent_map_tree *tree, 620 struct extent_state *state) 621 { 622 DEFINE_WAIT(wait); 623 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); 624 read_unlock_irq(&tree->lock); 625 schedule(); 626 read_lock_irq(&tree->lock); 627 finish_wait(&state->wq, &wait); 628 return 0; 629 } 630 631 /* 632 * waits for one or more bits to clear on a range in the state tree. 633 * The range [start, end] is inclusive. 634 * The tree lock is taken by this function 635 */ 636 int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits) 637 { 638 struct extent_state *state; 639 struct rb_node *node; 640 641 read_lock_irq(&tree->lock); 642 again: 643 while (1) { 644 /* 645 * this search will find all the extents that end after 646 * our range starts 647 */ 648 node = tree_search(&tree->state, start); 649 if (!node) 650 break; 651 652 state = rb_entry(node, struct extent_state, rb_node); 653 654 if (state->start > end) 655 goto out; 656 657 if (state->state & bits) { 658 start = state->start; 659 atomic_inc(&state->refs); 660 wait_on_state(tree, state); 661 free_extent_state(state); 662 goto again; 663 } 664 start = state->end + 1; 665 666 if (start > end) 667 break; 668 669 if (need_resched()) { 670 read_unlock_irq(&tree->lock); 671 cond_resched(); 672 read_lock_irq(&tree->lock); 673 } 674 } 675 out: 676 read_unlock_irq(&tree->lock); 677 return 0; 678 } 679 EXPORT_SYMBOL(wait_extent_bit); 680 681 static void set_state_bits(struct extent_map_tree *tree, 682 struct extent_state *state, 683 int bits) 684 { 685 if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) { 686 u64 range = state->end - state->start + 1; 687 tree->dirty_bytes += range; 688 } 689 state->state |= bits; 690 } 691 692 /* 693 * set some bits on a range in the tree. This may require allocations 694 * or sleeping, so the gfp mask is used to indicate what is allowed. 695 * 696 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the 697 * range already has the desired bits set. The start of the existing 698 * range is returned in failed_start in this case. 699 * 700 * [start, end] is inclusive 701 * This takes the tree lock. 702 */ 703 int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, 704 int exclusive, u64 *failed_start, gfp_t mask) 705 { 706 struct extent_state *state; 707 struct extent_state *prealloc = NULL; 708 struct rb_node *node; 709 unsigned long flags; 710 int err = 0; 711 int set; 712 u64 last_start; 713 u64 last_end; 714 again: 715 if (!prealloc && (mask & __GFP_WAIT)) { 716 prealloc = alloc_extent_state(mask); 717 if (!prealloc) 718 return -ENOMEM; 719 } 720 721 write_lock_irqsave(&tree->lock, flags); 722 /* 723 * this search will find all the extents that end after 724 * our range starts. 725 */ 726 node = tree_search(&tree->state, start); 727 if (!node) { 728 err = insert_state(tree, prealloc, start, end, bits); 729 prealloc = NULL; 730 BUG_ON(err == -EEXIST); 731 goto out; 732 } 733 734 state = rb_entry(node, struct extent_state, rb_node); 735 last_start = state->start; 736 last_end = state->end; 737 738 /* 739 * | ---- desired range ---- | 740 * | state | 741 * 742 * Just lock what we found and keep going 743 */ 744 if (state->start == start && state->end <= end) { 745 set = state->state & bits; 746 if (set && exclusive) { 747 *failed_start = state->start; 748 err = -EEXIST; 749 goto out; 750 } 751 set_state_bits(tree, state, bits); 752 start = state->end + 1; 753 merge_state(tree, state); 754 goto search_again; 755 } 756 757 /* 758 * | ---- desired range ---- | 759 * | state | 760 * or 761 * | ------------- state -------------- | 762 * 763 * We need to split the extent we found, and may flip bits on 764 * second half. 765 * 766 * If the extent we found extends past our 767 * range, we just split and search again. It'll get split 768 * again the next time though. 769 * 770 * If the extent we found is inside our range, we set the 771 * desired bit on it. 772 */ 773 if (state->start < start) { 774 set = state->state & bits; 775 if (exclusive && set) { 776 *failed_start = start; 777 err = -EEXIST; 778 goto out; 779 } 780 err = split_state(tree, state, prealloc, start); 781 BUG_ON(err == -EEXIST); 782 prealloc = NULL; 783 if (err) 784 goto out; 785 if (state->end <= end) { 786 set_state_bits(tree, state, bits); 787 start = state->end + 1; 788 merge_state(tree, state); 789 } else { 790 start = state->start; 791 } 792 goto search_again; 793 } 794 /* 795 * | ---- desired range ---- | 796 * | state | or | state | 797 * 798 * There's a hole, we need to insert something in it and 799 * ignore the extent we found. 800 */ 801 if (state->start > start) { 802 u64 this_end; 803 if (end < last_start) 804 this_end = end; 805 else 806 this_end = last_start -1; 807 err = insert_state(tree, prealloc, start, this_end, 808 bits); 809 prealloc = NULL; 810 BUG_ON(err == -EEXIST); 811 if (err) 812 goto out; 813 start = this_end + 1; 814 goto search_again; 815 } 816 /* 817 * | ---- desired range ---- | 818 * | state | 819 * We need to split the extent, and set the bit 820 * on the first half 821 */ 822 if (state->start <= end && state->end > end) { 823 set = state->state & bits; 824 if (exclusive && set) { 825 *failed_start = start; 826 err = -EEXIST; 827 goto out; 828 } 829 err = split_state(tree, state, prealloc, end + 1); 830 BUG_ON(err == -EEXIST); 831 832 set_state_bits(tree, prealloc, bits); 833 merge_state(tree, prealloc); 834 prealloc = NULL; 835 goto out; 836 } 837 838 goto search_again; 839 840 out: 841 write_unlock_irqrestore(&tree->lock, flags); 842 if (prealloc) 843 free_extent_state(prealloc); 844 845 return err; 846 847 search_again: 848 if (start > end) 849 goto out; 850 write_unlock_irqrestore(&tree->lock, flags); 851 if (mask & __GFP_WAIT) 852 cond_resched(); 853 goto again; 854 } 855 EXPORT_SYMBOL(set_extent_bit); 856 857 /* wrappers around set/clear extent bit */ 858 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 859 gfp_t mask) 860 { 861 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, 862 mask); 863 } 864 EXPORT_SYMBOL(set_extent_dirty); 865 866 int set_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 867 int bits, gfp_t mask) 868 { 869 return set_extent_bit(tree, start, end, bits, 0, NULL, 870 mask); 871 } 872 EXPORT_SYMBOL(set_extent_bits); 873 874 int clear_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, 875 int bits, gfp_t mask) 876 { 877 return clear_extent_bit(tree, start, end, bits, 0, 0, mask); 878 } 879 EXPORT_SYMBOL(clear_extent_bits); 880 881 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end, 882 gfp_t mask) 883 { 884 return set_extent_bit(tree, start, end, 885 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL, 886 mask); 887 } 888 EXPORT_SYMBOL(set_extent_delalloc); 889 890 int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, 891 gfp_t mask) 892 { 893 return clear_extent_bit(tree, start, end, 894 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask); 895 } 896 EXPORT_SYMBOL(clear_extent_dirty); 897 898 int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 899 gfp_t mask) 900 { 901 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, 902 mask); 903 } 904 EXPORT_SYMBOL(set_extent_new); 905 906 int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end, 907 gfp_t mask) 908 { 909 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask); 910 } 911 EXPORT_SYMBOL(clear_extent_new); 912 913 int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 914 gfp_t mask) 915 { 916 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL, 917 mask); 918 } 919 EXPORT_SYMBOL(set_extent_uptodate); 920 921 int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, 922 gfp_t mask) 923 { 924 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask); 925 } 926 EXPORT_SYMBOL(clear_extent_uptodate); 927 928 int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 929 gfp_t mask) 930 { 931 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK, 932 0, NULL, mask); 933 } 934 EXPORT_SYMBOL(set_extent_writeback); 935 936 int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, 937 gfp_t mask) 938 { 939 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask); 940 } 941 EXPORT_SYMBOL(clear_extent_writeback); 942 943 int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end) 944 { 945 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK); 946 } 947 EXPORT_SYMBOL(wait_on_extent_writeback); 948 949 /* 950 * locks a range in ascending order, waiting for any locked regions 951 * it hits on the way. [start,end] are inclusive, and this will sleep. 952 */ 953 int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask) 954 { 955 int err; 956 u64 failed_start; 957 while (1) { 958 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 959 &failed_start, mask); 960 if (err == -EEXIST && (mask & __GFP_WAIT)) { 961 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); 962 start = failed_start; 963 } else { 964 break; 965 } 966 WARN_ON(start > end); 967 } 968 return err; 969 } 970 EXPORT_SYMBOL(lock_extent); 971 972 int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, 973 gfp_t mask) 974 { 975 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask); 976 } 977 EXPORT_SYMBOL(unlock_extent); 978 979 /* 980 * helper function to set pages and extents in the tree dirty 981 */ 982 int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end) 983 { 984 unsigned long index = start >> PAGE_CACHE_SHIFT; 985 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 986 struct page *page; 987 988 while (index <= end_index) { 989 page = find_get_page(tree->mapping, index); 990 BUG_ON(!page); 991 __set_page_dirty_nobuffers(page); 992 page_cache_release(page); 993 index++; 994 } 995 set_extent_dirty(tree, start, end, GFP_NOFS); 996 return 0; 997 } 998 EXPORT_SYMBOL(set_range_dirty); 999 1000 /* 1001 * helper function to set both pages and extents in the tree writeback 1002 */ 1003 int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end) 1004 { 1005 unsigned long index = start >> PAGE_CACHE_SHIFT; 1006 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1007 struct page *page; 1008 1009 while (index <= end_index) { 1010 page = find_get_page(tree->mapping, index); 1011 BUG_ON(!page); 1012 set_page_writeback(page); 1013 page_cache_release(page); 1014 index++; 1015 } 1016 set_extent_writeback(tree, start, end, GFP_NOFS); 1017 return 0; 1018 } 1019 EXPORT_SYMBOL(set_range_writeback); 1020 1021 int find_first_extent_bit(struct extent_map_tree *tree, u64 start, 1022 u64 *start_ret, u64 *end_ret, int bits) 1023 { 1024 struct rb_node *node; 1025 struct extent_state *state; 1026 int ret = 1; 1027 1028 read_lock_irq(&tree->lock); 1029 /* 1030 * this search will find all the extents that end after 1031 * our range starts. 1032 */ 1033 node = tree_search(&tree->state, start); 1034 if (!node || IS_ERR(node)) { 1035 goto out; 1036 } 1037 1038 while(1) { 1039 state = rb_entry(node, struct extent_state, rb_node); 1040 if (state->end >= start && (state->state & bits)) { 1041 *start_ret = state->start; 1042 *end_ret = state->end; 1043 ret = 0; 1044 break; 1045 } 1046 node = rb_next(node); 1047 if (!node) 1048 break; 1049 } 1050 out: 1051 read_unlock_irq(&tree->lock); 1052 return ret; 1053 } 1054 EXPORT_SYMBOL(find_first_extent_bit); 1055 1056 u64 find_lock_delalloc_range(struct extent_map_tree *tree, 1057 u64 *start, u64 *end, u64 max_bytes) 1058 { 1059 struct rb_node *node; 1060 struct extent_state *state; 1061 u64 cur_start = *start; 1062 u64 found = 0; 1063 u64 total_bytes = 0; 1064 1065 write_lock_irq(&tree->lock); 1066 /* 1067 * this search will find all the extents that end after 1068 * our range starts. 1069 */ 1070 search_again: 1071 node = tree_search(&tree->state, cur_start); 1072 if (!node || IS_ERR(node)) { 1073 goto out; 1074 } 1075 1076 while(1) { 1077 state = rb_entry(node, struct extent_state, rb_node); 1078 if (found && state->start != cur_start) { 1079 goto out; 1080 } 1081 if (!(state->state & EXTENT_DELALLOC)) { 1082 goto out; 1083 } 1084 if (!found) { 1085 struct extent_state *prev_state; 1086 struct rb_node *prev_node = node; 1087 while(1) { 1088 prev_node = rb_prev(prev_node); 1089 if (!prev_node) 1090 break; 1091 prev_state = rb_entry(prev_node, 1092 struct extent_state, 1093 rb_node); 1094 if (!(prev_state->state & EXTENT_DELALLOC)) 1095 break; 1096 state = prev_state; 1097 node = prev_node; 1098 } 1099 } 1100 if (state->state & EXTENT_LOCKED) { 1101 DEFINE_WAIT(wait); 1102 atomic_inc(&state->refs); 1103 prepare_to_wait(&state->wq, &wait, 1104 TASK_UNINTERRUPTIBLE); 1105 write_unlock_irq(&tree->lock); 1106 schedule(); 1107 write_lock_irq(&tree->lock); 1108 finish_wait(&state->wq, &wait); 1109 free_extent_state(state); 1110 goto search_again; 1111 } 1112 state->state |= EXTENT_LOCKED; 1113 if (!found) 1114 *start = state->start; 1115 found++; 1116 *end = state->end; 1117 cur_start = state->end + 1; 1118 node = rb_next(node); 1119 if (!node) 1120 break; 1121 total_bytes += state->end - state->start + 1; 1122 if (total_bytes >= max_bytes) 1123 break; 1124 } 1125 out: 1126 write_unlock_irq(&tree->lock); 1127 return found; 1128 } 1129 1130 u64 count_range_bits(struct extent_map_tree *tree, 1131 u64 *start, u64 max_bytes, unsigned long bits) 1132 { 1133 struct rb_node *node; 1134 struct extent_state *state; 1135 u64 cur_start = *start; 1136 u64 total_bytes = 0; 1137 int found = 0; 1138 1139 write_lock_irq(&tree->lock); 1140 if (bits == EXTENT_DIRTY) { 1141 *start = 0; 1142 total_bytes = tree->dirty_bytes; 1143 goto out; 1144 } 1145 /* 1146 * this search will find all the extents that end after 1147 * our range starts. 1148 */ 1149 node = tree_search(&tree->state, cur_start); 1150 if (!node || IS_ERR(node)) { 1151 goto out; 1152 } 1153 1154 while(1) { 1155 state = rb_entry(node, struct extent_state, rb_node); 1156 if ((state->state & bits)) { 1157 total_bytes += state->end - state->start + 1; 1158 if (total_bytes >= max_bytes) 1159 break; 1160 if (!found) { 1161 *start = state->start; 1162 found = 1; 1163 } 1164 } 1165 node = rb_next(node); 1166 if (!node) 1167 break; 1168 } 1169 out: 1170 write_unlock_irq(&tree->lock); 1171 return total_bytes; 1172 } 1173 1174 /* 1175 * helper function to lock both pages and extents in the tree. 1176 * pages must be locked first. 1177 */ 1178 int lock_range(struct extent_map_tree *tree, u64 start, u64 end) 1179 { 1180 unsigned long index = start >> PAGE_CACHE_SHIFT; 1181 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1182 struct page *page; 1183 int err; 1184 1185 while (index <= end_index) { 1186 page = grab_cache_page(tree->mapping, index); 1187 if (!page) { 1188 err = -ENOMEM; 1189 goto failed; 1190 } 1191 if (IS_ERR(page)) { 1192 err = PTR_ERR(page); 1193 goto failed; 1194 } 1195 index++; 1196 } 1197 lock_extent(tree, start, end, GFP_NOFS); 1198 return 0; 1199 1200 failed: 1201 /* 1202 * we failed above in getting the page at 'index', so we undo here 1203 * up to but not including the page at 'index' 1204 */ 1205 end_index = index; 1206 index = start >> PAGE_CACHE_SHIFT; 1207 while (index < end_index) { 1208 page = find_get_page(tree->mapping, index); 1209 unlock_page(page); 1210 page_cache_release(page); 1211 index++; 1212 } 1213 return err; 1214 } 1215 EXPORT_SYMBOL(lock_range); 1216 1217 /* 1218 * helper function to unlock both pages and extents in the tree. 1219 */ 1220 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end) 1221 { 1222 unsigned long index = start >> PAGE_CACHE_SHIFT; 1223 unsigned long end_index = end >> PAGE_CACHE_SHIFT; 1224 struct page *page; 1225 1226 while (index <= end_index) { 1227 page = find_get_page(tree->mapping, index); 1228 unlock_page(page); 1229 page_cache_release(page); 1230 index++; 1231 } 1232 unlock_extent(tree, start, end, GFP_NOFS); 1233 return 0; 1234 } 1235 EXPORT_SYMBOL(unlock_range); 1236 1237 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private) 1238 { 1239 struct rb_node *node; 1240 struct extent_state *state; 1241 int ret = 0; 1242 1243 write_lock_irq(&tree->lock); 1244 /* 1245 * this search will find all the extents that end after 1246 * our range starts. 1247 */ 1248 node = tree_search(&tree->state, start); 1249 if (!node || IS_ERR(node)) { 1250 ret = -ENOENT; 1251 goto out; 1252 } 1253 state = rb_entry(node, struct extent_state, rb_node); 1254 if (state->start != start) { 1255 ret = -ENOENT; 1256 goto out; 1257 } 1258 state->private = private; 1259 out: 1260 write_unlock_irq(&tree->lock); 1261 return ret; 1262 } 1263 1264 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private) 1265 { 1266 struct rb_node *node; 1267 struct extent_state *state; 1268 int ret = 0; 1269 1270 read_lock_irq(&tree->lock); 1271 /* 1272 * this search will find all the extents that end after 1273 * our range starts. 1274 */ 1275 node = tree_search(&tree->state, start); 1276 if (!node || IS_ERR(node)) { 1277 ret = -ENOENT; 1278 goto out; 1279 } 1280 state = rb_entry(node, struct extent_state, rb_node); 1281 if (state->start != start) { 1282 ret = -ENOENT; 1283 goto out; 1284 } 1285 *private = state->private; 1286 out: 1287 read_unlock_irq(&tree->lock); 1288 return ret; 1289 } 1290 1291 /* 1292 * searches a range in the state tree for a given mask. 1293 * If 'filled' == 1, this returns 1 only if ever extent in the tree 1294 * has the bits set. Otherwise, 1 is returned if any bit in the 1295 * range is found set. 1296 */ 1297 int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end, 1298 int bits, int filled) 1299 { 1300 struct extent_state *state = NULL; 1301 struct rb_node *node; 1302 int bitset = 0; 1303 1304 read_lock_irq(&tree->lock); 1305 node = tree_search(&tree->state, start); 1306 while (node && start <= end) { 1307 state = rb_entry(node, struct extent_state, rb_node); 1308 1309 if (filled && state->start > start) { 1310 bitset = 0; 1311 break; 1312 } 1313 1314 if (state->start > end) 1315 break; 1316 1317 if (state->state & bits) { 1318 bitset = 1; 1319 if (!filled) 1320 break; 1321 } else if (filled) { 1322 bitset = 0; 1323 break; 1324 } 1325 start = state->end + 1; 1326 if (start > end) 1327 break; 1328 node = rb_next(node); 1329 } 1330 read_unlock_irq(&tree->lock); 1331 return bitset; 1332 } 1333 EXPORT_SYMBOL(test_range_bit); 1334 1335 /* 1336 * helper function to set a given page up to date if all the 1337 * extents in the tree for that page are up to date 1338 */ 1339 static int check_page_uptodate(struct extent_map_tree *tree, 1340 struct page *page) 1341 { 1342 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1343 u64 end = start + PAGE_CACHE_SIZE - 1; 1344 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1)) 1345 SetPageUptodate(page); 1346 return 0; 1347 } 1348 1349 /* 1350 * helper function to unlock a page if all the extents in the tree 1351 * for that page are unlocked 1352 */ 1353 static int check_page_locked(struct extent_map_tree *tree, 1354 struct page *page) 1355 { 1356 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1357 u64 end = start + PAGE_CACHE_SIZE - 1; 1358 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0)) 1359 unlock_page(page); 1360 return 0; 1361 } 1362 1363 /* 1364 * helper function to end page writeback if all the extents 1365 * in the tree for that page are done with writeback 1366 */ 1367 static int check_page_writeback(struct extent_map_tree *tree, 1368 struct page *page) 1369 { 1370 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1371 u64 end = start + PAGE_CACHE_SIZE - 1; 1372 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0)) 1373 end_page_writeback(page); 1374 return 0; 1375 } 1376 1377 /* lots and lots of room for performance fixes in the end_bio funcs */ 1378 1379 /* 1380 * after a writepage IO is done, we need to: 1381 * clear the uptodate bits on error 1382 * clear the writeback bits in the extent tree for this IO 1383 * end_page_writeback if the page has no more pending IO 1384 * 1385 * Scheduling is not allowed, so the extent state tree is expected 1386 * to have one and only one object corresponding to this IO. 1387 */ 1388 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1389 static void end_bio_extent_writepage(struct bio *bio, int err) 1390 #else 1391 static int end_bio_extent_writepage(struct bio *bio, 1392 unsigned int bytes_done, int err) 1393 #endif 1394 { 1395 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1396 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1397 struct extent_map_tree *tree = bio->bi_private; 1398 u64 start; 1399 u64 end; 1400 int whole_page; 1401 1402 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1403 if (bio->bi_size) 1404 return 1; 1405 #endif 1406 1407 do { 1408 struct page *page = bvec->bv_page; 1409 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1410 bvec->bv_offset; 1411 end = start + bvec->bv_len - 1; 1412 1413 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1414 whole_page = 1; 1415 else 1416 whole_page = 0; 1417 1418 if (--bvec >= bio->bi_io_vec) 1419 prefetchw(&bvec->bv_page->flags); 1420 1421 if (!uptodate) { 1422 clear_extent_uptodate(tree, start, end, GFP_ATOMIC); 1423 ClearPageUptodate(page); 1424 SetPageError(page); 1425 } 1426 clear_extent_writeback(tree, start, end, GFP_ATOMIC); 1427 1428 if (whole_page) 1429 end_page_writeback(page); 1430 else 1431 check_page_writeback(tree, page); 1432 if (tree->ops && tree->ops->writepage_end_io_hook) 1433 tree->ops->writepage_end_io_hook(page, start, end); 1434 } while (bvec >= bio->bi_io_vec); 1435 1436 bio_put(bio); 1437 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1438 return 0; 1439 #endif 1440 } 1441 1442 /* 1443 * after a readpage IO is done, we need to: 1444 * clear the uptodate bits on error 1445 * set the uptodate bits if things worked 1446 * set the page up to date if all extents in the tree are uptodate 1447 * clear the lock bit in the extent tree 1448 * unlock the page if there are no other extents locked for it 1449 * 1450 * Scheduling is not allowed, so the extent state tree is expected 1451 * to have one and only one object corresponding to this IO. 1452 */ 1453 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1454 static void end_bio_extent_readpage(struct bio *bio, int err) 1455 #else 1456 static int end_bio_extent_readpage(struct bio *bio, 1457 unsigned int bytes_done, int err) 1458 #endif 1459 { 1460 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1461 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1462 struct extent_map_tree *tree = bio->bi_private; 1463 u64 start; 1464 u64 end; 1465 int whole_page; 1466 int ret; 1467 1468 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1469 if (bio->bi_size) 1470 return 1; 1471 #endif 1472 1473 do { 1474 struct page *page = bvec->bv_page; 1475 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1476 bvec->bv_offset; 1477 end = start + bvec->bv_len - 1; 1478 1479 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) 1480 whole_page = 1; 1481 else 1482 whole_page = 0; 1483 1484 if (--bvec >= bio->bi_io_vec) 1485 prefetchw(&bvec->bv_page->flags); 1486 1487 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { 1488 ret = tree->ops->readpage_end_io_hook(page, start, end); 1489 if (ret) 1490 uptodate = 0; 1491 } 1492 if (uptodate) { 1493 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1494 if (whole_page) 1495 SetPageUptodate(page); 1496 else 1497 check_page_uptodate(tree, page); 1498 } else { 1499 ClearPageUptodate(page); 1500 SetPageError(page); 1501 } 1502 1503 unlock_extent(tree, start, end, GFP_ATOMIC); 1504 1505 if (whole_page) 1506 unlock_page(page); 1507 else 1508 check_page_locked(tree, page); 1509 } while (bvec >= bio->bi_io_vec); 1510 1511 bio_put(bio); 1512 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1513 return 0; 1514 #endif 1515 } 1516 1517 /* 1518 * IO done from prepare_write is pretty simple, we just unlock 1519 * the structs in the extent tree when done, and set the uptodate bits 1520 * as appropriate. 1521 */ 1522 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) 1523 static void end_bio_extent_preparewrite(struct bio *bio, int err) 1524 #else 1525 static int end_bio_extent_preparewrite(struct bio *bio, 1526 unsigned int bytes_done, int err) 1527 #endif 1528 { 1529 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1530 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 1531 struct extent_map_tree *tree = bio->bi_private; 1532 u64 start; 1533 u64 end; 1534 1535 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1536 if (bio->bi_size) 1537 return 1; 1538 #endif 1539 1540 do { 1541 struct page *page = bvec->bv_page; 1542 start = ((u64)page->index << PAGE_CACHE_SHIFT) + 1543 bvec->bv_offset; 1544 end = start + bvec->bv_len - 1; 1545 1546 if (--bvec >= bio->bi_io_vec) 1547 prefetchw(&bvec->bv_page->flags); 1548 1549 if (uptodate) { 1550 set_extent_uptodate(tree, start, end, GFP_ATOMIC); 1551 } else { 1552 ClearPageUptodate(page); 1553 SetPageError(page); 1554 } 1555 1556 unlock_extent(tree, start, end, GFP_ATOMIC); 1557 1558 } while (bvec >= bio->bi_io_vec); 1559 1560 bio_put(bio); 1561 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) 1562 return 0; 1563 #endif 1564 } 1565 1566 static struct bio * 1567 extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, 1568 gfp_t gfp_flags) 1569 { 1570 struct bio *bio; 1571 1572 bio = bio_alloc(gfp_flags, nr_vecs); 1573 1574 if (bio == NULL && (current->flags & PF_MEMALLOC)) { 1575 while (!bio && (nr_vecs /= 2)) 1576 bio = bio_alloc(gfp_flags, nr_vecs); 1577 } 1578 1579 if (bio) { 1580 bio->bi_bdev = bdev; 1581 bio->bi_sector = first_sector; 1582 } 1583 return bio; 1584 } 1585 1586 static int submit_one_bio(int rw, struct bio *bio) 1587 { 1588 u64 maxsector; 1589 int ret = 0; 1590 1591 bio_get(bio); 1592 1593 maxsector = bio->bi_bdev->bd_inode->i_size >> 9; 1594 if (maxsector < bio->bi_sector) { 1595 printk("sector too large max %Lu got %llu\n", maxsector, 1596 (unsigned long long)bio->bi_sector); 1597 WARN_ON(1); 1598 } 1599 1600 submit_bio(rw, bio); 1601 if (bio_flagged(bio, BIO_EOPNOTSUPP)) 1602 ret = -EOPNOTSUPP; 1603 bio_put(bio); 1604 return ret; 1605 } 1606 1607 static int submit_extent_page(int rw, struct extent_map_tree *tree, 1608 struct page *page, sector_t sector, 1609 size_t size, unsigned long offset, 1610 struct block_device *bdev, 1611 struct bio **bio_ret, 1612 unsigned long max_pages, 1613 bio_end_io_t end_io_func) 1614 { 1615 int ret = 0; 1616 struct bio *bio; 1617 int nr; 1618 1619 if (bio_ret && *bio_ret) { 1620 bio = *bio_ret; 1621 if (bio->bi_sector + (bio->bi_size >> 9) != sector || 1622 bio_add_page(bio, page, size, offset) < size) { 1623 ret = submit_one_bio(rw, bio); 1624 bio = NULL; 1625 } else { 1626 return 0; 1627 } 1628 } 1629 nr = min_t(int, max_pages, bio_get_nr_vecs(bdev)); 1630 bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH); 1631 if (!bio) { 1632 printk("failed to allocate bio nr %d\n", nr); 1633 } 1634 bio_add_page(bio, page, size, offset); 1635 bio->bi_end_io = end_io_func; 1636 bio->bi_private = tree; 1637 if (bio_ret) { 1638 *bio_ret = bio; 1639 } else { 1640 ret = submit_one_bio(rw, bio); 1641 } 1642 1643 return ret; 1644 } 1645 1646 void set_page_extent_mapped(struct page *page) 1647 { 1648 if (!PagePrivate(page)) { 1649 SetPagePrivate(page); 1650 WARN_ON(!page->mapping->a_ops->invalidatepage); 1651 set_page_private(page, EXTENT_PAGE_PRIVATE); 1652 page_cache_get(page); 1653 } 1654 } 1655 1656 /* 1657 * basic readpage implementation. Locked extent state structs are inserted 1658 * into the tree that are removed when the IO is done (by the end_io 1659 * handlers) 1660 */ 1661 static int __extent_read_full_page(struct extent_map_tree *tree, 1662 struct page *page, 1663 get_extent_t *get_extent, 1664 struct bio **bio) 1665 { 1666 struct inode *inode = page->mapping->host; 1667 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1668 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1669 u64 end; 1670 u64 cur = start; 1671 u64 extent_offset; 1672 u64 last_byte = i_size_read(inode); 1673 u64 block_start; 1674 u64 cur_end; 1675 sector_t sector; 1676 struct extent_map *em; 1677 struct block_device *bdev; 1678 int ret; 1679 int nr = 0; 1680 size_t page_offset = 0; 1681 size_t iosize; 1682 size_t blocksize = inode->i_sb->s_blocksize; 1683 1684 set_page_extent_mapped(page); 1685 1686 end = page_end; 1687 lock_extent(tree, start, end, GFP_NOFS); 1688 1689 while (cur <= end) { 1690 if (cur >= last_byte) { 1691 char *userpage; 1692 iosize = PAGE_CACHE_SIZE - page_offset; 1693 userpage = kmap_atomic(page, KM_USER0); 1694 memset(userpage + page_offset, 0, iosize); 1695 flush_dcache_page(page); 1696 kunmap_atomic(userpage, KM_USER0); 1697 set_extent_uptodate(tree, cur, cur + iosize - 1, 1698 GFP_NOFS); 1699 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1700 break; 1701 } 1702 em = get_extent(inode, page, page_offset, cur, end, 0); 1703 if (IS_ERR(em) || !em) { 1704 SetPageError(page); 1705 unlock_extent(tree, cur, end, GFP_NOFS); 1706 break; 1707 } 1708 1709 extent_offset = cur - em->start; 1710 BUG_ON(em->end < cur); 1711 BUG_ON(end < cur); 1712 1713 iosize = min(em->end - cur, end - cur) + 1; 1714 cur_end = min(em->end, end); 1715 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1716 sector = (em->block_start + extent_offset) >> 9; 1717 bdev = em->bdev; 1718 block_start = em->block_start; 1719 free_extent_map(em); 1720 em = NULL; 1721 1722 /* we've found a hole, just zero and go on */ 1723 if (block_start == EXTENT_MAP_HOLE) { 1724 char *userpage; 1725 userpage = kmap_atomic(page, KM_USER0); 1726 memset(userpage + page_offset, 0, iosize); 1727 flush_dcache_page(page); 1728 kunmap_atomic(userpage, KM_USER0); 1729 1730 set_extent_uptodate(tree, cur, cur + iosize - 1, 1731 GFP_NOFS); 1732 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1733 cur = cur + iosize; 1734 page_offset += iosize; 1735 continue; 1736 } 1737 /* the get_extent function already copied into the page */ 1738 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { 1739 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1740 cur = cur + iosize; 1741 page_offset += iosize; 1742 continue; 1743 } 1744 1745 ret = 0; 1746 if (tree->ops && tree->ops->readpage_io_hook) { 1747 ret = tree->ops->readpage_io_hook(page, cur, 1748 cur + iosize - 1); 1749 } 1750 if (!ret) { 1751 unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1; 1752 nr -= page->index; 1753 ret = submit_extent_page(READ, tree, page, 1754 sector, iosize, page_offset, 1755 bdev, bio, nr, 1756 end_bio_extent_readpage); 1757 } 1758 if (ret) 1759 SetPageError(page); 1760 cur = cur + iosize; 1761 page_offset += iosize; 1762 nr++; 1763 } 1764 if (!nr) { 1765 if (!PageError(page)) 1766 SetPageUptodate(page); 1767 unlock_page(page); 1768 } 1769 return 0; 1770 } 1771 1772 int extent_read_full_page(struct extent_map_tree *tree, struct page *page, 1773 get_extent_t *get_extent) 1774 { 1775 struct bio *bio = NULL; 1776 int ret; 1777 1778 ret = __extent_read_full_page(tree, page, get_extent, &bio); 1779 if (bio) 1780 submit_one_bio(READ, bio); 1781 return ret; 1782 } 1783 EXPORT_SYMBOL(extent_read_full_page); 1784 1785 /* 1786 * the writepage semantics are similar to regular writepage. extent 1787 * records are inserted to lock ranges in the tree, and as dirty areas 1788 * are found, they are marked writeback. Then the lock bits are removed 1789 * and the end_io handler clears the writeback ranges 1790 */ 1791 static int __extent_writepage(struct page *page, struct writeback_control *wbc, 1792 void *data) 1793 { 1794 struct inode *inode = page->mapping->host; 1795 struct extent_page_data *epd = data; 1796 struct extent_map_tree *tree = epd->tree; 1797 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1798 u64 delalloc_start; 1799 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1800 u64 end; 1801 u64 cur = start; 1802 u64 extent_offset; 1803 u64 last_byte = i_size_read(inode); 1804 u64 block_start; 1805 u64 iosize; 1806 sector_t sector; 1807 struct extent_map *em; 1808 struct block_device *bdev; 1809 int ret; 1810 int nr = 0; 1811 size_t page_offset = 0; 1812 size_t blocksize; 1813 loff_t i_size = i_size_read(inode); 1814 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; 1815 u64 nr_delalloc; 1816 u64 delalloc_end; 1817 1818 WARN_ON(!PageLocked(page)); 1819 if (page->index > end_index) { 1820 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1821 unlock_page(page); 1822 return 0; 1823 } 1824 1825 if (page->index == end_index) { 1826 char *userpage; 1827 1828 size_t offset = i_size & (PAGE_CACHE_SIZE - 1); 1829 1830 userpage = kmap_atomic(page, KM_USER0); 1831 memset(userpage + offset, 0, PAGE_CACHE_SIZE - offset); 1832 flush_dcache_page(page); 1833 kunmap_atomic(userpage, KM_USER0); 1834 } 1835 1836 set_page_extent_mapped(page); 1837 1838 delalloc_start = start; 1839 delalloc_end = 0; 1840 while(delalloc_end < page_end) { 1841 nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start, 1842 &delalloc_end, 1843 128 * 1024 * 1024); 1844 if (nr_delalloc <= 0) 1845 break; 1846 tree->ops->fill_delalloc(inode, delalloc_start, 1847 delalloc_end); 1848 clear_extent_bit(tree, delalloc_start, 1849 delalloc_end, 1850 EXTENT_LOCKED | EXTENT_DELALLOC, 1851 1, 0, GFP_NOFS); 1852 delalloc_start = delalloc_end + 1; 1853 } 1854 lock_extent(tree, start, page_end, GFP_NOFS); 1855 1856 end = page_end; 1857 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1858 printk("found delalloc bits after lock_extent\n"); 1859 } 1860 1861 if (last_byte <= start) { 1862 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1863 goto done; 1864 } 1865 1866 set_extent_uptodate(tree, start, page_end, GFP_NOFS); 1867 blocksize = inode->i_sb->s_blocksize; 1868 1869 while (cur <= end) { 1870 if (cur >= last_byte) { 1871 clear_extent_dirty(tree, cur, page_end, GFP_NOFS); 1872 break; 1873 } 1874 em = epd->get_extent(inode, page, page_offset, cur, end, 1); 1875 if (IS_ERR(em) || !em) { 1876 SetPageError(page); 1877 break; 1878 } 1879 1880 extent_offset = cur - em->start; 1881 BUG_ON(em->end < cur); 1882 BUG_ON(end < cur); 1883 iosize = min(em->end - cur, end - cur) + 1; 1884 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1885 sector = (em->block_start + extent_offset) >> 9; 1886 bdev = em->bdev; 1887 block_start = em->block_start; 1888 free_extent_map(em); 1889 em = NULL; 1890 1891 if (block_start == EXTENT_MAP_HOLE || 1892 block_start == EXTENT_MAP_INLINE) { 1893 clear_extent_dirty(tree, cur, 1894 cur + iosize - 1, GFP_NOFS); 1895 cur = cur + iosize; 1896 page_offset += iosize; 1897 continue; 1898 } 1899 1900 /* leave this out until we have a page_mkwrite call */ 1901 if (0 && !test_range_bit(tree, cur, cur + iosize - 1, 1902 EXTENT_DIRTY, 0)) { 1903 cur = cur + iosize; 1904 page_offset += iosize; 1905 continue; 1906 } 1907 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); 1908 if (tree->ops && tree->ops->writepage_io_hook) { 1909 ret = tree->ops->writepage_io_hook(page, cur, 1910 cur + iosize - 1); 1911 } else { 1912 ret = 0; 1913 } 1914 if (ret) 1915 SetPageError(page); 1916 else { 1917 unsigned long max_nr = end_index + 1; 1918 set_range_writeback(tree, cur, cur + iosize - 1); 1919 if (!PageWriteback(page)) { 1920 printk("warning page %lu not writeback, " 1921 "cur %llu end %llu\n", page->index, 1922 (unsigned long long)cur, 1923 (unsigned long long)end); 1924 } 1925 1926 ret = submit_extent_page(WRITE, tree, page, sector, 1927 iosize, page_offset, bdev, 1928 &epd->bio, max_nr, 1929 end_bio_extent_writepage); 1930 if (ret) 1931 SetPageError(page); 1932 } 1933 cur = cur + iosize; 1934 page_offset += iosize; 1935 nr++; 1936 } 1937 done: 1938 if (nr == 0) { 1939 /* make sure the mapping tag for page dirty gets cleared */ 1940 set_page_writeback(page); 1941 end_page_writeback(page); 1942 } 1943 unlock_extent(tree, start, page_end, GFP_NOFS); 1944 unlock_page(page); 1945 return 0; 1946 } 1947 1948 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18) 1949 1950 /* Taken directly from 2.6.23 for 2.6.18 back port */ 1951 typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, 1952 void *data); 1953 1954 /** 1955 * write_cache_pages - walk the list of dirty pages of the given address space 1956 * and write all of them. 1957 * @mapping: address space structure to write 1958 * @wbc: subtract the number of written pages from *@wbc->nr_to_write 1959 * @writepage: function called for each page 1960 * @data: data passed to writepage function 1961 * 1962 * If a page is already under I/O, write_cache_pages() skips it, even 1963 * if it's dirty. This is desirable behaviour for memory-cleaning writeback, 1964 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync() 1965 * and msync() need to guarantee that all the data which was dirty at the time 1966 * the call was made get new I/O started against them. If wbc->sync_mode is 1967 * WB_SYNC_ALL then we were called for data integrity and we must wait for 1968 * existing IO to complete. 1969 */ 1970 static int write_cache_pages(struct address_space *mapping, 1971 struct writeback_control *wbc, writepage_t writepage, 1972 void *data) 1973 { 1974 struct backing_dev_info *bdi = mapping->backing_dev_info; 1975 int ret = 0; 1976 int done = 0; 1977 struct pagevec pvec; 1978 int nr_pages; 1979 pgoff_t index; 1980 pgoff_t end; /* Inclusive */ 1981 int scanned = 0; 1982 int range_whole = 0; 1983 1984 if (wbc->nonblocking && bdi_write_congested(bdi)) { 1985 wbc->encountered_congestion = 1; 1986 return 0; 1987 } 1988 1989 pagevec_init(&pvec, 0); 1990 if (wbc->range_cyclic) { 1991 index = mapping->writeback_index; /* Start from prev offset */ 1992 end = -1; 1993 } else { 1994 index = wbc->range_start >> PAGE_CACHE_SHIFT; 1995 end = wbc->range_end >> PAGE_CACHE_SHIFT; 1996 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) 1997 range_whole = 1; 1998 scanned = 1; 1999 } 2000 retry: 2001 while (!done && (index <= end) && 2002 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, 2003 PAGECACHE_TAG_DIRTY, 2004 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { 2005 unsigned i; 2006 2007 scanned = 1; 2008 for (i = 0; i < nr_pages; i++) { 2009 struct page *page = pvec.pages[i]; 2010 2011 /* 2012 * At this point we hold neither mapping->tree_lock nor 2013 * lock on the page itself: the page may be truncated or 2014 * invalidated (changing page->mapping to NULL), or even 2015 * swizzled back from swapper_space to tmpfs file 2016 * mapping 2017 */ 2018 lock_page(page); 2019 2020 if (unlikely(page->mapping != mapping)) { 2021 unlock_page(page); 2022 continue; 2023 } 2024 2025 if (!wbc->range_cyclic && page->index > end) { 2026 done = 1; 2027 unlock_page(page); 2028 continue; 2029 } 2030 2031 if (wbc->sync_mode != WB_SYNC_NONE) 2032 wait_on_page_writeback(page); 2033 2034 if (PageWriteback(page) || 2035 !clear_page_dirty_for_io(page)) { 2036 unlock_page(page); 2037 continue; 2038 } 2039 2040 ret = (*writepage)(page, wbc, data); 2041 2042 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) { 2043 unlock_page(page); 2044 ret = 0; 2045 } 2046 if (ret || (--(wbc->nr_to_write) <= 0)) 2047 done = 1; 2048 if (wbc->nonblocking && bdi_write_congested(bdi)) { 2049 wbc->encountered_congestion = 1; 2050 done = 1; 2051 } 2052 } 2053 pagevec_release(&pvec); 2054 cond_resched(); 2055 } 2056 if (!scanned && !done) { 2057 /* 2058 * We hit the last page and there is more work to be done: wrap 2059 * back to the start of the file 2060 */ 2061 scanned = 1; 2062 index = 0; 2063 goto retry; 2064 } 2065 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) 2066 mapping->writeback_index = index; 2067 return ret; 2068 } 2069 #endif 2070 2071 int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 2072 get_extent_t *get_extent, 2073 struct writeback_control *wbc) 2074 { 2075 int ret; 2076 struct address_space *mapping = page->mapping; 2077 struct extent_page_data epd = { 2078 .bio = NULL, 2079 .tree = tree, 2080 .get_extent = get_extent, 2081 }; 2082 struct writeback_control wbc_writepages = { 2083 .bdi = wbc->bdi, 2084 .sync_mode = WB_SYNC_NONE, 2085 .older_than_this = NULL, 2086 .nr_to_write = 64, 2087 .range_start = page_offset(page) + PAGE_CACHE_SIZE, 2088 .range_end = (loff_t)-1, 2089 }; 2090 2091 2092 ret = __extent_writepage(page, wbc, &epd); 2093 2094 write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd); 2095 if (epd.bio) { 2096 submit_one_bio(WRITE, epd.bio); 2097 } 2098 return ret; 2099 } 2100 EXPORT_SYMBOL(extent_write_full_page); 2101 2102 2103 int extent_writepages(struct extent_map_tree *tree, 2104 struct address_space *mapping, 2105 get_extent_t *get_extent, 2106 struct writeback_control *wbc) 2107 { 2108 int ret = 0; 2109 struct extent_page_data epd = { 2110 .bio = NULL, 2111 .tree = tree, 2112 .get_extent = get_extent, 2113 }; 2114 2115 ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd); 2116 if (epd.bio) { 2117 submit_one_bio(WRITE, epd.bio); 2118 } 2119 return ret; 2120 } 2121 EXPORT_SYMBOL(extent_writepages); 2122 2123 int extent_readpages(struct extent_map_tree *tree, 2124 struct address_space *mapping, 2125 struct list_head *pages, unsigned nr_pages, 2126 get_extent_t get_extent) 2127 { 2128 struct bio *bio = NULL; 2129 unsigned page_idx; 2130 struct pagevec pvec; 2131 2132 pagevec_init(&pvec, 0); 2133 for (page_idx = 0; page_idx < nr_pages; page_idx++) { 2134 struct page *page = list_entry(pages->prev, struct page, lru); 2135 2136 prefetchw(&page->flags); 2137 list_del(&page->lru); 2138 /* 2139 * what we want to do here is call add_to_page_cache_lru, 2140 * but that isn't exported, so we reproduce it here 2141 */ 2142 if (!add_to_page_cache(page, mapping, 2143 page->index, GFP_KERNEL)) { 2144 2145 /* open coding of lru_cache_add, also not exported */ 2146 page_cache_get(page); 2147 if (!pagevec_add(&pvec, page)) 2148 __pagevec_lru_add(&pvec); 2149 __extent_read_full_page(tree, page, get_extent, &bio); 2150 } 2151 page_cache_release(page); 2152 } 2153 if (pagevec_count(&pvec)) 2154 __pagevec_lru_add(&pvec); 2155 BUG_ON(!list_empty(pages)); 2156 if (bio) 2157 submit_one_bio(READ, bio); 2158 return 0; 2159 } 2160 EXPORT_SYMBOL(extent_readpages); 2161 2162 /* 2163 * basic invalidatepage code, this waits on any locked or writeback 2164 * ranges corresponding to the page, and then deletes any extent state 2165 * records from the tree 2166 */ 2167 int extent_invalidatepage(struct extent_map_tree *tree, 2168 struct page *page, unsigned long offset) 2169 { 2170 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT); 2171 u64 end = start + PAGE_CACHE_SIZE - 1; 2172 size_t blocksize = page->mapping->host->i_sb->s_blocksize; 2173 2174 start += (offset + blocksize -1) & ~(blocksize - 1); 2175 if (start > end) 2176 return 0; 2177 2178 lock_extent(tree, start, end, GFP_NOFS); 2179 wait_on_extent_writeback(tree, start, end); 2180 clear_extent_bit(tree, start, end, 2181 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, 2182 1, 1, GFP_NOFS); 2183 return 0; 2184 } 2185 EXPORT_SYMBOL(extent_invalidatepage); 2186 2187 /* 2188 * simple commit_write call, set_range_dirty is used to mark both 2189 * the pages and the extent records as dirty 2190 */ 2191 int extent_commit_write(struct extent_map_tree *tree, 2192 struct inode *inode, struct page *page, 2193 unsigned from, unsigned to) 2194 { 2195 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; 2196 2197 set_page_extent_mapped(page); 2198 set_page_dirty(page); 2199 2200 if (pos > inode->i_size) { 2201 i_size_write(inode, pos); 2202 mark_inode_dirty(inode); 2203 } 2204 return 0; 2205 } 2206 EXPORT_SYMBOL(extent_commit_write); 2207 2208 int extent_prepare_write(struct extent_map_tree *tree, 2209 struct inode *inode, struct page *page, 2210 unsigned from, unsigned to, get_extent_t *get_extent) 2211 { 2212 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 2213 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 2214 u64 block_start; 2215 u64 orig_block_start; 2216 u64 block_end; 2217 u64 cur_end; 2218 struct extent_map *em; 2219 unsigned blocksize = 1 << inode->i_blkbits; 2220 size_t page_offset = 0; 2221 size_t block_off_start; 2222 size_t block_off_end; 2223 int err = 0; 2224 int iocount = 0; 2225 int ret = 0; 2226 int isnew; 2227 2228 set_page_extent_mapped(page); 2229 2230 block_start = (page_start + from) & ~((u64)blocksize - 1); 2231 block_end = (page_start + to - 1) | (blocksize - 1); 2232 orig_block_start = block_start; 2233 2234 lock_extent(tree, page_start, page_end, GFP_NOFS); 2235 while(block_start <= block_end) { 2236 em = get_extent(inode, page, page_offset, block_start, 2237 block_end, 1); 2238 if (IS_ERR(em) || !em) { 2239 goto err; 2240 } 2241 cur_end = min(block_end, em->end); 2242 block_off_start = block_start & (PAGE_CACHE_SIZE - 1); 2243 block_off_end = block_off_start + blocksize; 2244 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); 2245 2246 if (!PageUptodate(page) && isnew && 2247 (block_off_end > to || block_off_start < from)) { 2248 void *kaddr; 2249 2250 kaddr = kmap_atomic(page, KM_USER0); 2251 if (block_off_end > to) 2252 memset(kaddr + to, 0, block_off_end - to); 2253 if (block_off_start < from) 2254 memset(kaddr + block_off_start, 0, 2255 from - block_off_start); 2256 flush_dcache_page(page); 2257 kunmap_atomic(kaddr, KM_USER0); 2258 } 2259 if ((em->block_start != EXTENT_MAP_HOLE && 2260 em->block_start != EXTENT_MAP_INLINE) && 2261 !isnew && !PageUptodate(page) && 2262 (block_off_end > to || block_off_start < from) && 2263 !test_range_bit(tree, block_start, cur_end, 2264 EXTENT_UPTODATE, 1)) { 2265 u64 sector; 2266 u64 extent_offset = block_start - em->start; 2267 size_t iosize; 2268 sector = (em->block_start + extent_offset) >> 9; 2269 iosize = (cur_end - block_start + blocksize - 1) & 2270 ~((u64)blocksize - 1); 2271 /* 2272 * we've already got the extent locked, but we 2273 * need to split the state such that our end_bio 2274 * handler can clear the lock. 2275 */ 2276 set_extent_bit(tree, block_start, 2277 block_start + iosize - 1, 2278 EXTENT_LOCKED, 0, NULL, GFP_NOFS); 2279 ret = submit_extent_page(READ, tree, page, 2280 sector, iosize, page_offset, em->bdev, 2281 NULL, 1, 2282 end_bio_extent_preparewrite); 2283 iocount++; 2284 block_start = block_start + iosize; 2285 } else { 2286 set_extent_uptodate(tree, block_start, cur_end, 2287 GFP_NOFS); 2288 unlock_extent(tree, block_start, cur_end, GFP_NOFS); 2289 block_start = cur_end + 1; 2290 } 2291 page_offset = block_start & (PAGE_CACHE_SIZE - 1); 2292 free_extent_map(em); 2293 } 2294 if (iocount) { 2295 wait_extent_bit(tree, orig_block_start, 2296 block_end, EXTENT_LOCKED); 2297 } 2298 check_page_uptodate(tree, page); 2299 err: 2300 /* FIXME, zero out newly allocated blocks on error */ 2301 return err; 2302 } 2303 EXPORT_SYMBOL(extent_prepare_write); 2304 2305 /* 2306 * a helper for releasepage. As long as there are no locked extents 2307 * in the range corresponding to the page, both state records and extent 2308 * map records are removed 2309 */ 2310 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) 2311 { 2312 struct extent_map *em; 2313 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 2314 u64 end = start + PAGE_CACHE_SIZE - 1; 2315 u64 orig_start = start; 2316 int ret = 1; 2317 2318 while (start <= end) { 2319 em = lookup_extent_mapping(tree, start, end); 2320 if (!em || IS_ERR(em)) 2321 break; 2322 if (!test_range_bit(tree, em->start, em->end, 2323 EXTENT_LOCKED, 0)) { 2324 remove_extent_mapping(tree, em); 2325 /* once for the rb tree */ 2326 free_extent_map(em); 2327 } 2328 start = em->end + 1; 2329 /* once for us */ 2330 free_extent_map(em); 2331 } 2332 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) 2333 ret = 0; 2334 else 2335 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, 2336 1, 1, GFP_NOFS); 2337 return ret; 2338 } 2339 EXPORT_SYMBOL(try_release_extent_mapping); 2340 2341 sector_t extent_bmap(struct address_space *mapping, sector_t iblock, 2342 get_extent_t *get_extent) 2343 { 2344 struct inode *inode = mapping->host; 2345 u64 start = iblock << inode->i_blkbits; 2346 u64 end = start + (1 << inode->i_blkbits) - 1; 2347 sector_t sector = 0; 2348 struct extent_map *em; 2349 2350 em = get_extent(inode, NULL, 0, start, end, 0); 2351 if (!em || IS_ERR(em)) 2352 return 0; 2353 2354 if (em->block_start == EXTENT_MAP_INLINE || 2355 em->block_start == EXTENT_MAP_HOLE) 2356 goto out; 2357 2358 sector = (em->block_start + start - em->start) >> inode->i_blkbits; 2359 out: 2360 free_extent_map(em); 2361 return sector; 2362 } 2363 2364 static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb) 2365 { 2366 if (list_empty(&eb->lru)) { 2367 extent_buffer_get(eb); 2368 list_add(&eb->lru, &tree->buffer_lru); 2369 tree->lru_size++; 2370 if (tree->lru_size >= BUFFER_LRU_MAX) { 2371 struct extent_buffer *rm; 2372 rm = list_entry(tree->buffer_lru.prev, 2373 struct extent_buffer, lru); 2374 tree->lru_size--; 2375 list_del_init(&rm->lru); 2376 free_extent_buffer(rm); 2377 } 2378 } else 2379 list_move(&eb->lru, &tree->buffer_lru); 2380 return 0; 2381 } 2382 static struct extent_buffer *find_lru(struct extent_map_tree *tree, 2383 u64 start, unsigned long len) 2384 { 2385 struct list_head *lru = &tree->buffer_lru; 2386 struct list_head *cur = lru->next; 2387 struct extent_buffer *eb; 2388 2389 if (list_empty(lru)) 2390 return NULL; 2391 2392 do { 2393 eb = list_entry(cur, struct extent_buffer, lru); 2394 if (eb->start == start && eb->len == len) { 2395 extent_buffer_get(eb); 2396 return eb; 2397 } 2398 cur = cur->next; 2399 } while (cur != lru); 2400 return NULL; 2401 } 2402 2403 static inline unsigned long num_extent_pages(u64 start, u64 len) 2404 { 2405 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - 2406 (start >> PAGE_CACHE_SHIFT); 2407 } 2408 2409 static inline struct page *extent_buffer_page(struct extent_buffer *eb, 2410 unsigned long i) 2411 { 2412 struct page *p; 2413 struct address_space *mapping; 2414 2415 if (i == 0) 2416 return eb->first_page; 2417 i += eb->start >> PAGE_CACHE_SHIFT; 2418 mapping = eb->first_page->mapping; 2419 read_lock_irq(&mapping->tree_lock); 2420 p = radix_tree_lookup(&mapping->page_tree, i); 2421 read_unlock_irq(&mapping->tree_lock); 2422 return p; 2423 } 2424 2425 static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, 2426 u64 start, 2427 unsigned long len, 2428 gfp_t mask) 2429 { 2430 struct extent_buffer *eb = NULL; 2431 2432 spin_lock(&tree->lru_lock); 2433 eb = find_lru(tree, start, len); 2434 spin_unlock(&tree->lru_lock); 2435 if (eb) { 2436 return eb; 2437 } 2438 2439 eb = kmem_cache_zalloc(extent_buffer_cache, mask); 2440 INIT_LIST_HEAD(&eb->lru); 2441 eb->start = start; 2442 eb->len = len; 2443 atomic_set(&eb->refs, 1); 2444 2445 return eb; 2446 } 2447 2448 static void __free_extent_buffer(struct extent_buffer *eb) 2449 { 2450 kmem_cache_free(extent_buffer_cache, eb); 2451 } 2452 2453 struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 2454 u64 start, unsigned long len, 2455 struct page *page0, 2456 gfp_t mask) 2457 { 2458 unsigned long num_pages = num_extent_pages(start, len); 2459 unsigned long i; 2460 unsigned long index = start >> PAGE_CACHE_SHIFT; 2461 struct extent_buffer *eb; 2462 struct page *p; 2463 struct address_space *mapping = tree->mapping; 2464 int uptodate = 1; 2465 2466 eb = __alloc_extent_buffer(tree, start, len, mask); 2467 if (!eb || IS_ERR(eb)) 2468 return NULL; 2469 2470 if (eb->flags & EXTENT_BUFFER_FILLED) 2471 goto lru_add; 2472 2473 if (page0) { 2474 eb->first_page = page0; 2475 i = 1; 2476 index++; 2477 page_cache_get(page0); 2478 mark_page_accessed(page0); 2479 set_page_extent_mapped(page0); 2480 WARN_ON(!PageUptodate(page0)); 2481 set_page_private(page0, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2482 len << 2); 2483 } else { 2484 i = 0; 2485 } 2486 for (; i < num_pages; i++, index++) { 2487 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM); 2488 if (!p) { 2489 WARN_ON(1); 2490 goto fail; 2491 } 2492 set_page_extent_mapped(p); 2493 mark_page_accessed(p); 2494 if (i == 0) { 2495 eb->first_page = p; 2496 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2497 len << 2); 2498 } else { 2499 set_page_private(p, EXTENT_PAGE_PRIVATE); 2500 } 2501 if (!PageUptodate(p)) 2502 uptodate = 0; 2503 unlock_page(p); 2504 } 2505 if (uptodate) 2506 eb->flags |= EXTENT_UPTODATE; 2507 eb->flags |= EXTENT_BUFFER_FILLED; 2508 2509 lru_add: 2510 spin_lock(&tree->lru_lock); 2511 add_lru(tree, eb); 2512 spin_unlock(&tree->lru_lock); 2513 return eb; 2514 2515 fail: 2516 spin_lock(&tree->lru_lock); 2517 list_del_init(&eb->lru); 2518 spin_unlock(&tree->lru_lock); 2519 if (!atomic_dec_and_test(&eb->refs)) 2520 return NULL; 2521 for (index = 1; index < i; index++) { 2522 page_cache_release(extent_buffer_page(eb, index)); 2523 } 2524 if (i > 0) 2525 page_cache_release(extent_buffer_page(eb, 0)); 2526 __free_extent_buffer(eb); 2527 return NULL; 2528 } 2529 EXPORT_SYMBOL(alloc_extent_buffer); 2530 2531 struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 2532 u64 start, unsigned long len, 2533 gfp_t mask) 2534 { 2535 unsigned long num_pages = num_extent_pages(start, len); 2536 unsigned long i; 2537 unsigned long index = start >> PAGE_CACHE_SHIFT; 2538 struct extent_buffer *eb; 2539 struct page *p; 2540 struct address_space *mapping = tree->mapping; 2541 int uptodate = 1; 2542 2543 eb = __alloc_extent_buffer(tree, start, len, mask); 2544 if (!eb || IS_ERR(eb)) 2545 return NULL; 2546 2547 if (eb->flags & EXTENT_BUFFER_FILLED) 2548 goto lru_add; 2549 2550 for (i = 0; i < num_pages; i++, index++) { 2551 p = find_lock_page(mapping, index); 2552 if (!p) { 2553 goto fail; 2554 } 2555 set_page_extent_mapped(p); 2556 mark_page_accessed(p); 2557 2558 if (i == 0) { 2559 eb->first_page = p; 2560 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2561 len << 2); 2562 } else { 2563 set_page_private(p, EXTENT_PAGE_PRIVATE); 2564 } 2565 2566 if (!PageUptodate(p)) 2567 uptodate = 0; 2568 unlock_page(p); 2569 } 2570 if (uptodate) 2571 eb->flags |= EXTENT_UPTODATE; 2572 eb->flags |= EXTENT_BUFFER_FILLED; 2573 2574 lru_add: 2575 spin_lock(&tree->lru_lock); 2576 add_lru(tree, eb); 2577 spin_unlock(&tree->lru_lock); 2578 return eb; 2579 fail: 2580 spin_lock(&tree->lru_lock); 2581 list_del_init(&eb->lru); 2582 spin_unlock(&tree->lru_lock); 2583 if (!atomic_dec_and_test(&eb->refs)) 2584 return NULL; 2585 for (index = 1; index < i; index++) { 2586 page_cache_release(extent_buffer_page(eb, index)); 2587 } 2588 if (i > 0) 2589 page_cache_release(extent_buffer_page(eb, 0)); 2590 __free_extent_buffer(eb); 2591 return NULL; 2592 } 2593 EXPORT_SYMBOL(find_extent_buffer); 2594 2595 void free_extent_buffer(struct extent_buffer *eb) 2596 { 2597 unsigned long i; 2598 unsigned long num_pages; 2599 2600 if (!eb) 2601 return; 2602 2603 if (!atomic_dec_and_test(&eb->refs)) 2604 return; 2605 2606 WARN_ON(!list_empty(&eb->lru)); 2607 num_pages = num_extent_pages(eb->start, eb->len); 2608 2609 for (i = 1; i < num_pages; i++) { 2610 page_cache_release(extent_buffer_page(eb, i)); 2611 } 2612 page_cache_release(extent_buffer_page(eb, 0)); 2613 __free_extent_buffer(eb); 2614 } 2615 EXPORT_SYMBOL(free_extent_buffer); 2616 2617 int clear_extent_buffer_dirty(struct extent_map_tree *tree, 2618 struct extent_buffer *eb) 2619 { 2620 int set; 2621 unsigned long i; 2622 unsigned long num_pages; 2623 struct page *page; 2624 2625 u64 start = eb->start; 2626 u64 end = start + eb->len - 1; 2627 2628 set = clear_extent_dirty(tree, start, end, GFP_NOFS); 2629 num_pages = num_extent_pages(eb->start, eb->len); 2630 2631 for (i = 0; i < num_pages; i++) { 2632 page = extent_buffer_page(eb, i); 2633 lock_page(page); 2634 /* 2635 * if we're on the last page or the first page and the 2636 * block isn't aligned on a page boundary, do extra checks 2637 * to make sure we don't clean page that is partially dirty 2638 */ 2639 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2640 ((i == num_pages - 1) && 2641 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2642 start = (u64)page->index << PAGE_CACHE_SHIFT; 2643 end = start + PAGE_CACHE_SIZE - 1; 2644 if (test_range_bit(tree, start, end, 2645 EXTENT_DIRTY, 0)) { 2646 unlock_page(page); 2647 continue; 2648 } 2649 } 2650 clear_page_dirty_for_io(page); 2651 write_lock_irq(&page->mapping->tree_lock); 2652 if (!PageDirty(page)) { 2653 radix_tree_tag_clear(&page->mapping->page_tree, 2654 page_index(page), 2655 PAGECACHE_TAG_DIRTY); 2656 } 2657 write_unlock_irq(&page->mapping->tree_lock); 2658 unlock_page(page); 2659 } 2660 return 0; 2661 } 2662 EXPORT_SYMBOL(clear_extent_buffer_dirty); 2663 2664 int wait_on_extent_buffer_writeback(struct extent_map_tree *tree, 2665 struct extent_buffer *eb) 2666 { 2667 return wait_on_extent_writeback(tree, eb->start, 2668 eb->start + eb->len - 1); 2669 } 2670 EXPORT_SYMBOL(wait_on_extent_buffer_writeback); 2671 2672 int set_extent_buffer_dirty(struct extent_map_tree *tree, 2673 struct extent_buffer *eb) 2674 { 2675 unsigned long i; 2676 unsigned long num_pages; 2677 2678 num_pages = num_extent_pages(eb->start, eb->len); 2679 for (i = 0; i < num_pages; i++) { 2680 struct page *page = extent_buffer_page(eb, i); 2681 /* writepage may need to do something special for the 2682 * first page, we have to make sure page->private is 2683 * properly set. releasepage may drop page->private 2684 * on us if the page isn't already dirty. 2685 */ 2686 if (i == 0) { 2687 lock_page(page); 2688 set_page_private(page, 2689 EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2690 eb->len << 2); 2691 } 2692 __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); 2693 if (i == 0) 2694 unlock_page(page); 2695 } 2696 return set_extent_dirty(tree, eb->start, 2697 eb->start + eb->len - 1, GFP_NOFS); 2698 } 2699 EXPORT_SYMBOL(set_extent_buffer_dirty); 2700 2701 int set_extent_buffer_uptodate(struct extent_map_tree *tree, 2702 struct extent_buffer *eb) 2703 { 2704 unsigned long i; 2705 struct page *page; 2706 unsigned long num_pages; 2707 2708 num_pages = num_extent_pages(eb->start, eb->len); 2709 2710 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, 2711 GFP_NOFS); 2712 for (i = 0; i < num_pages; i++) { 2713 page = extent_buffer_page(eb, i); 2714 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2715 ((i == num_pages - 1) && 2716 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2717 check_page_uptodate(tree, page); 2718 continue; 2719 } 2720 SetPageUptodate(page); 2721 } 2722 return 0; 2723 } 2724 EXPORT_SYMBOL(set_extent_buffer_uptodate); 2725 2726 int extent_buffer_uptodate(struct extent_map_tree *tree, 2727 struct extent_buffer *eb) 2728 { 2729 if (eb->flags & EXTENT_UPTODATE) 2730 return 1; 2731 return test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2732 EXTENT_UPTODATE, 1); 2733 } 2734 EXPORT_SYMBOL(extent_buffer_uptodate); 2735 2736 int read_extent_buffer_pages(struct extent_map_tree *tree, 2737 struct extent_buffer *eb, 2738 u64 start, 2739 int wait) 2740 { 2741 unsigned long i; 2742 unsigned long start_i; 2743 struct page *page; 2744 int err; 2745 int ret = 0; 2746 unsigned long num_pages; 2747 2748 if (eb->flags & EXTENT_UPTODATE) 2749 return 0; 2750 2751 if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2752 EXTENT_UPTODATE, 1)) { 2753 return 0; 2754 } 2755 2756 if (start) { 2757 WARN_ON(start < eb->start); 2758 start_i = (start >> PAGE_CACHE_SHIFT) - 2759 (eb->start >> PAGE_CACHE_SHIFT); 2760 } else { 2761 start_i = 0; 2762 } 2763 2764 num_pages = num_extent_pages(eb->start, eb->len); 2765 for (i = start_i; i < num_pages; i++) { 2766 page = extent_buffer_page(eb, i); 2767 if (PageUptodate(page)) { 2768 continue; 2769 } 2770 if (!wait) { 2771 if (TestSetPageLocked(page)) { 2772 continue; 2773 } 2774 } else { 2775 lock_page(page); 2776 } 2777 if (!PageUptodate(page)) { 2778 err = page->mapping->a_ops->readpage(NULL, page); 2779 if (err) { 2780 ret = err; 2781 } 2782 } else { 2783 unlock_page(page); 2784 } 2785 } 2786 2787 if (ret || !wait) { 2788 return ret; 2789 } 2790 2791 for (i = start_i; i < num_pages; i++) { 2792 page = extent_buffer_page(eb, i); 2793 wait_on_page_locked(page); 2794 if (!PageUptodate(page)) { 2795 ret = -EIO; 2796 } 2797 } 2798 if (!ret) 2799 eb->flags |= EXTENT_UPTODATE; 2800 return ret; 2801 } 2802 EXPORT_SYMBOL(read_extent_buffer_pages); 2803 2804 void read_extent_buffer(struct extent_buffer *eb, void *dstv, 2805 unsigned long start, 2806 unsigned long len) 2807 { 2808 size_t cur; 2809 size_t offset; 2810 struct page *page; 2811 char *kaddr; 2812 char *dst = (char *)dstv; 2813 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2814 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2815 unsigned long num_pages = num_extent_pages(eb->start, eb->len); 2816 2817 WARN_ON(start > eb->len); 2818 WARN_ON(start + len > eb->start + eb->len); 2819 2820 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2821 2822 while(len > 0) { 2823 page = extent_buffer_page(eb, i); 2824 if (!PageUptodate(page)) { 2825 printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); 2826 WARN_ON(1); 2827 } 2828 WARN_ON(!PageUptodate(page)); 2829 2830 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2831 kaddr = kmap_atomic(page, KM_USER1); 2832 memcpy(dst, kaddr + offset, cur); 2833 kunmap_atomic(kaddr, KM_USER1); 2834 2835 dst += cur; 2836 len -= cur; 2837 offset = 0; 2838 i++; 2839 } 2840 } 2841 EXPORT_SYMBOL(read_extent_buffer); 2842 2843 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, 2844 unsigned long min_len, char **token, char **map, 2845 unsigned long *map_start, 2846 unsigned long *map_len, int km) 2847 { 2848 size_t offset = start & (PAGE_CACHE_SIZE - 1); 2849 char *kaddr; 2850 struct page *p; 2851 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2852 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2853 unsigned long end_i = (start_offset + start + min_len - 1) >> 2854 PAGE_CACHE_SHIFT; 2855 2856 if (i != end_i) 2857 return -EINVAL; 2858 2859 if (i == 0) { 2860 offset = start_offset; 2861 *map_start = 0; 2862 } else { 2863 offset = 0; 2864 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset; 2865 } 2866 if (start + min_len > eb->len) { 2867 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); 2868 WARN_ON(1); 2869 } 2870 2871 p = extent_buffer_page(eb, i); 2872 WARN_ON(!PageUptodate(p)); 2873 kaddr = kmap_atomic(p, km); 2874 *token = kaddr; 2875 *map = kaddr + offset; 2876 *map_len = PAGE_CACHE_SIZE - offset; 2877 return 0; 2878 } 2879 EXPORT_SYMBOL(map_private_extent_buffer); 2880 2881 int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 2882 unsigned long min_len, 2883 char **token, char **map, 2884 unsigned long *map_start, 2885 unsigned long *map_len, int km) 2886 { 2887 int err; 2888 int save = 0; 2889 if (eb->map_token) { 2890 unmap_extent_buffer(eb, eb->map_token, km); 2891 eb->map_token = NULL; 2892 save = 1; 2893 } 2894 err = map_private_extent_buffer(eb, start, min_len, token, map, 2895 map_start, map_len, km); 2896 if (!err && save) { 2897 eb->map_token = *token; 2898 eb->kaddr = *map; 2899 eb->map_start = *map_start; 2900 eb->map_len = *map_len; 2901 } 2902 return err; 2903 } 2904 EXPORT_SYMBOL(map_extent_buffer); 2905 2906 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) 2907 { 2908 kunmap_atomic(token, km); 2909 } 2910 EXPORT_SYMBOL(unmap_extent_buffer); 2911 2912 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 2913 unsigned long start, 2914 unsigned long len) 2915 { 2916 size_t cur; 2917 size_t offset; 2918 struct page *page; 2919 char *kaddr; 2920 char *ptr = (char *)ptrv; 2921 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2922 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2923 int ret = 0; 2924 2925 WARN_ON(start > eb->len); 2926 WARN_ON(start + len > eb->start + eb->len); 2927 2928 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2929 2930 while(len > 0) { 2931 page = extent_buffer_page(eb, i); 2932 WARN_ON(!PageUptodate(page)); 2933 2934 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2935 2936 kaddr = kmap_atomic(page, KM_USER0); 2937 ret = memcmp(ptr, kaddr + offset, cur); 2938 kunmap_atomic(kaddr, KM_USER0); 2939 if (ret) 2940 break; 2941 2942 ptr += cur; 2943 len -= cur; 2944 offset = 0; 2945 i++; 2946 } 2947 return ret; 2948 } 2949 EXPORT_SYMBOL(memcmp_extent_buffer); 2950 2951 void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 2952 unsigned long start, unsigned long len) 2953 { 2954 size_t cur; 2955 size_t offset; 2956 struct page *page; 2957 char *kaddr; 2958 char *src = (char *)srcv; 2959 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2960 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2961 2962 WARN_ON(start > eb->len); 2963 WARN_ON(start + len > eb->start + eb->len); 2964 2965 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2966 2967 while(len > 0) { 2968 page = extent_buffer_page(eb, i); 2969 WARN_ON(!PageUptodate(page)); 2970 2971 cur = min(len, PAGE_CACHE_SIZE - offset); 2972 kaddr = kmap_atomic(page, KM_USER1); 2973 memcpy(kaddr + offset, src, cur); 2974 kunmap_atomic(kaddr, KM_USER1); 2975 2976 src += cur; 2977 len -= cur; 2978 offset = 0; 2979 i++; 2980 } 2981 } 2982 EXPORT_SYMBOL(write_extent_buffer); 2983 2984 void memset_extent_buffer(struct extent_buffer *eb, char c, 2985 unsigned long start, unsigned long len) 2986 { 2987 size_t cur; 2988 size_t offset; 2989 struct page *page; 2990 char *kaddr; 2991 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2992 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2993 2994 WARN_ON(start > eb->len); 2995 WARN_ON(start + len > eb->start + eb->len); 2996 2997 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2998 2999 while(len > 0) { 3000 page = extent_buffer_page(eb, i); 3001 WARN_ON(!PageUptodate(page)); 3002 3003 cur = min(len, PAGE_CACHE_SIZE - offset); 3004 kaddr = kmap_atomic(page, KM_USER0); 3005 memset(kaddr + offset, c, cur); 3006 kunmap_atomic(kaddr, KM_USER0); 3007 3008 len -= cur; 3009 offset = 0; 3010 i++; 3011 } 3012 } 3013 EXPORT_SYMBOL(memset_extent_buffer); 3014 3015 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 3016 unsigned long dst_offset, unsigned long src_offset, 3017 unsigned long len) 3018 { 3019 u64 dst_len = dst->len; 3020 size_t cur; 3021 size_t offset; 3022 struct page *page; 3023 char *kaddr; 3024 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 3025 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 3026 3027 WARN_ON(src->len != dst_len); 3028 3029 offset = (start_offset + dst_offset) & 3030 ((unsigned long)PAGE_CACHE_SIZE - 1); 3031 3032 while(len > 0) { 3033 page = extent_buffer_page(dst, i); 3034 WARN_ON(!PageUptodate(page)); 3035 3036 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset)); 3037 3038 kaddr = kmap_atomic(page, KM_USER0); 3039 read_extent_buffer(src, kaddr + offset, src_offset, cur); 3040 kunmap_atomic(kaddr, KM_USER0); 3041 3042 src_offset += cur; 3043 len -= cur; 3044 offset = 0; 3045 i++; 3046 } 3047 } 3048 EXPORT_SYMBOL(copy_extent_buffer); 3049 3050 static void move_pages(struct page *dst_page, struct page *src_page, 3051 unsigned long dst_off, unsigned long src_off, 3052 unsigned long len) 3053 { 3054 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 3055 if (dst_page == src_page) { 3056 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len); 3057 } else { 3058 char *src_kaddr = kmap_atomic(src_page, KM_USER1); 3059 char *p = dst_kaddr + dst_off + len; 3060 char *s = src_kaddr + src_off + len; 3061 3062 while (len--) 3063 *--p = *--s; 3064 3065 kunmap_atomic(src_kaddr, KM_USER1); 3066 } 3067 kunmap_atomic(dst_kaddr, KM_USER0); 3068 } 3069 3070 static void copy_pages(struct page *dst_page, struct page *src_page, 3071 unsigned long dst_off, unsigned long src_off, 3072 unsigned long len) 3073 { 3074 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 3075 char *src_kaddr; 3076 3077 if (dst_page != src_page) 3078 src_kaddr = kmap_atomic(src_page, KM_USER1); 3079 else 3080 src_kaddr = dst_kaddr; 3081 3082 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); 3083 kunmap_atomic(dst_kaddr, KM_USER0); 3084 if (dst_page != src_page) 3085 kunmap_atomic(src_kaddr, KM_USER1); 3086 } 3087 3088 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 3089 unsigned long src_offset, unsigned long len) 3090 { 3091 size_t cur; 3092 size_t dst_off_in_page; 3093 size_t src_off_in_page; 3094 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 3095 unsigned long dst_i; 3096 unsigned long src_i; 3097 3098 if (src_offset + len > dst->len) { 3099 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 3100 src_offset, len, dst->len); 3101 BUG_ON(1); 3102 } 3103 if (dst_offset + len > dst->len) { 3104 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 3105 dst_offset, len, dst->len); 3106 BUG_ON(1); 3107 } 3108 3109 while(len > 0) { 3110 dst_off_in_page = (start_offset + dst_offset) & 3111 ((unsigned long)PAGE_CACHE_SIZE - 1); 3112 src_off_in_page = (start_offset + src_offset) & 3113 ((unsigned long)PAGE_CACHE_SIZE - 1); 3114 3115 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 3116 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT; 3117 3118 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - 3119 src_off_in_page)); 3120 cur = min_t(unsigned long, cur, 3121 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page)); 3122 3123 copy_pages(extent_buffer_page(dst, dst_i), 3124 extent_buffer_page(dst, src_i), 3125 dst_off_in_page, src_off_in_page, cur); 3126 3127 src_offset += cur; 3128 dst_offset += cur; 3129 len -= cur; 3130 } 3131 } 3132 EXPORT_SYMBOL(memcpy_extent_buffer); 3133 3134 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 3135 unsigned long src_offset, unsigned long len) 3136 { 3137 size_t cur; 3138 size_t dst_off_in_page; 3139 size_t src_off_in_page; 3140 unsigned long dst_end = dst_offset + len - 1; 3141 unsigned long src_end = src_offset + len - 1; 3142 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 3143 unsigned long dst_i; 3144 unsigned long src_i; 3145 3146 if (src_offset + len > dst->len) { 3147 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 3148 src_offset, len, dst->len); 3149 BUG_ON(1); 3150 } 3151 if (dst_offset + len > dst->len) { 3152 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 3153 dst_offset, len, dst->len); 3154 BUG_ON(1); 3155 } 3156 if (dst_offset < src_offset) { 3157 memcpy_extent_buffer(dst, dst_offset, src_offset, len); 3158 return; 3159 } 3160 while(len > 0) { 3161 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT; 3162 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT; 3163 3164 dst_off_in_page = (start_offset + dst_end) & 3165 ((unsigned long)PAGE_CACHE_SIZE - 1); 3166 src_off_in_page = (start_offset + src_end) & 3167 ((unsigned long)PAGE_CACHE_SIZE - 1); 3168 3169 cur = min_t(unsigned long, len, src_off_in_page + 1); 3170 cur = min(cur, dst_off_in_page + 1); 3171 move_pages(extent_buffer_page(dst, dst_i), 3172 extent_buffer_page(dst, src_i), 3173 dst_off_in_page - cur + 1, 3174 src_off_in_page - cur + 1, cur); 3175 3176 dst_end -= cur; 3177 src_end -= cur; 3178 len -= cur; 3179 } 3180 } 3181 EXPORT_SYMBOL(memmove_extent_buffer); 3182