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 /* 1667 * basic readpage implementation. Locked extent state structs are inserted 1668 * into the tree that are removed when the IO is done (by the end_io 1669 * handlers) 1670 */ 1671 static int __extent_read_full_page(struct extent_map_tree *tree, 1672 struct page *page, 1673 get_extent_t *get_extent, 1674 struct bio **bio) 1675 { 1676 struct inode *inode = page->mapping->host; 1677 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1678 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1679 u64 end; 1680 u64 cur = start; 1681 u64 extent_offset; 1682 u64 last_byte = i_size_read(inode); 1683 u64 block_start; 1684 u64 cur_end; 1685 sector_t sector; 1686 struct extent_map *em; 1687 struct block_device *bdev; 1688 int ret; 1689 int nr = 0; 1690 size_t page_offset = 0; 1691 size_t iosize; 1692 size_t blocksize = inode->i_sb->s_blocksize; 1693 1694 set_page_extent_mapped(page); 1695 1696 end = page_end; 1697 lock_extent(tree, start, end, GFP_NOFS); 1698 1699 while (cur <= end) { 1700 if (cur >= last_byte) { 1701 char *userpage; 1702 iosize = PAGE_CACHE_SIZE - page_offset; 1703 userpage = kmap_atomic(page, KM_USER0); 1704 memset(userpage + page_offset, 0, iosize); 1705 flush_dcache_page(page); 1706 kunmap_atomic(userpage, KM_USER0); 1707 set_extent_uptodate(tree, cur, cur + iosize - 1, 1708 GFP_NOFS); 1709 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1710 break; 1711 } 1712 em = get_extent(inode, page, page_offset, cur, end, 0); 1713 if (IS_ERR(em) || !em) { 1714 SetPageError(page); 1715 unlock_extent(tree, cur, end, GFP_NOFS); 1716 break; 1717 } 1718 1719 extent_offset = cur - em->start; 1720 BUG_ON(em->end < cur); 1721 BUG_ON(end < cur); 1722 1723 iosize = min(em->end - cur, end - cur) + 1; 1724 cur_end = min(em->end, end); 1725 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1726 sector = (em->block_start + extent_offset) >> 9; 1727 bdev = em->bdev; 1728 block_start = em->block_start; 1729 free_extent_map(em); 1730 em = NULL; 1731 1732 /* we've found a hole, just zero and go on */ 1733 if (block_start == EXTENT_MAP_HOLE) { 1734 char *userpage; 1735 userpage = kmap_atomic(page, KM_USER0); 1736 memset(userpage + page_offset, 0, iosize); 1737 flush_dcache_page(page); 1738 kunmap_atomic(userpage, KM_USER0); 1739 1740 set_extent_uptodate(tree, cur, cur + iosize - 1, 1741 GFP_NOFS); 1742 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1743 cur = cur + iosize; 1744 page_offset += iosize; 1745 continue; 1746 } 1747 /* the get_extent function already copied into the page */ 1748 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) { 1749 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); 1750 cur = cur + iosize; 1751 page_offset += iosize; 1752 continue; 1753 } 1754 1755 ret = 0; 1756 if (tree->ops && tree->ops->readpage_io_hook) { 1757 ret = tree->ops->readpage_io_hook(page, cur, 1758 cur + iosize - 1); 1759 } 1760 if (!ret) { 1761 unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1; 1762 nr -= page->index; 1763 ret = submit_extent_page(READ, tree, page, 1764 sector, iosize, page_offset, 1765 bdev, bio, nr, 1766 end_bio_extent_readpage); 1767 } 1768 if (ret) 1769 SetPageError(page); 1770 cur = cur + iosize; 1771 page_offset += iosize; 1772 nr++; 1773 } 1774 if (!nr) { 1775 if (!PageError(page)) 1776 SetPageUptodate(page); 1777 unlock_page(page); 1778 } 1779 return 0; 1780 } 1781 1782 int extent_read_full_page(struct extent_map_tree *tree, struct page *page, 1783 get_extent_t *get_extent) 1784 { 1785 struct bio *bio = NULL; 1786 int ret; 1787 1788 ret = __extent_read_full_page(tree, page, get_extent, &bio); 1789 if (bio) 1790 submit_one_bio(READ, bio); 1791 return ret; 1792 } 1793 EXPORT_SYMBOL(extent_read_full_page); 1794 1795 /* 1796 * the writepage semantics are similar to regular writepage. extent 1797 * records are inserted to lock ranges in the tree, and as dirty areas 1798 * are found, they are marked writeback. Then the lock bits are removed 1799 * and the end_io handler clears the writeback ranges 1800 */ 1801 static int __extent_writepage(struct page *page, struct writeback_control *wbc, 1802 void *data) 1803 { 1804 struct inode *inode = page->mapping->host; 1805 struct extent_page_data *epd = data; 1806 struct extent_map_tree *tree = epd->tree; 1807 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 1808 u64 delalloc_start; 1809 u64 page_end = start + PAGE_CACHE_SIZE - 1; 1810 u64 end; 1811 u64 cur = start; 1812 u64 extent_offset; 1813 u64 last_byte = i_size_read(inode); 1814 u64 block_start; 1815 u64 iosize; 1816 sector_t sector; 1817 struct extent_map *em; 1818 struct block_device *bdev; 1819 int ret; 1820 int nr = 0; 1821 size_t page_offset = 0; 1822 size_t blocksize; 1823 loff_t i_size = i_size_read(inode); 1824 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT; 1825 u64 nr_delalloc; 1826 u64 delalloc_end; 1827 1828 WARN_ON(!PageLocked(page)); 1829 if (page->index > end_index) { 1830 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1831 unlock_page(page); 1832 return 0; 1833 } 1834 1835 if (page->index == end_index) { 1836 char *userpage; 1837 1838 size_t offset = i_size & (PAGE_CACHE_SIZE - 1); 1839 1840 userpage = kmap_atomic(page, KM_USER0); 1841 memset(userpage + offset, 0, PAGE_CACHE_SIZE - offset); 1842 flush_dcache_page(page); 1843 kunmap_atomic(userpage, KM_USER0); 1844 } 1845 1846 set_page_extent_mapped(page); 1847 1848 delalloc_start = start; 1849 delalloc_end = 0; 1850 while(delalloc_end < page_end) { 1851 nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start, 1852 &delalloc_end, 1853 128 * 1024 * 1024); 1854 if (nr_delalloc == 0) { 1855 delalloc_start = delalloc_end + 1; 1856 continue; 1857 } 1858 tree->ops->fill_delalloc(inode, delalloc_start, 1859 delalloc_end); 1860 clear_extent_bit(tree, delalloc_start, 1861 delalloc_end, 1862 EXTENT_LOCKED | EXTENT_DELALLOC, 1863 1, 0, GFP_NOFS); 1864 delalloc_start = delalloc_end + 1; 1865 } 1866 lock_extent(tree, start, page_end, GFP_NOFS); 1867 1868 end = page_end; 1869 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { 1870 printk("found delalloc bits after lock_extent\n"); 1871 } 1872 1873 if (last_byte <= start) { 1874 clear_extent_dirty(tree, start, page_end, GFP_NOFS); 1875 goto done; 1876 } 1877 1878 set_extent_uptodate(tree, start, page_end, GFP_NOFS); 1879 blocksize = inode->i_sb->s_blocksize; 1880 1881 while (cur <= end) { 1882 if (cur >= last_byte) { 1883 clear_extent_dirty(tree, cur, page_end, GFP_NOFS); 1884 break; 1885 } 1886 em = epd->get_extent(inode, page, page_offset, cur, end, 1); 1887 if (IS_ERR(em) || !em) { 1888 SetPageError(page); 1889 break; 1890 } 1891 1892 extent_offset = cur - em->start; 1893 BUG_ON(em->end < cur); 1894 BUG_ON(end < cur); 1895 iosize = min(em->end - cur, end - cur) + 1; 1896 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); 1897 sector = (em->block_start + extent_offset) >> 9; 1898 bdev = em->bdev; 1899 block_start = em->block_start; 1900 free_extent_map(em); 1901 em = NULL; 1902 1903 if (block_start == EXTENT_MAP_HOLE || 1904 block_start == EXTENT_MAP_INLINE) { 1905 clear_extent_dirty(tree, cur, 1906 cur + iosize - 1, GFP_NOFS); 1907 cur = cur + iosize; 1908 page_offset += iosize; 1909 continue; 1910 } 1911 1912 /* leave this out until we have a page_mkwrite call */ 1913 if (0 && !test_range_bit(tree, cur, cur + iosize - 1, 1914 EXTENT_DIRTY, 0)) { 1915 cur = cur + iosize; 1916 page_offset += iosize; 1917 continue; 1918 } 1919 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); 1920 if (tree->ops && tree->ops->writepage_io_hook) { 1921 ret = tree->ops->writepage_io_hook(page, cur, 1922 cur + iosize - 1); 1923 } else { 1924 ret = 0; 1925 } 1926 if (ret) 1927 SetPageError(page); 1928 else { 1929 unsigned long max_nr = end_index + 1; 1930 set_range_writeback(tree, cur, cur + iosize - 1); 1931 if (!PageWriteback(page)) { 1932 printk("warning page %lu not writeback, " 1933 "cur %llu end %llu\n", page->index, 1934 (unsigned long long)cur, 1935 (unsigned long long)end); 1936 } 1937 1938 ret = submit_extent_page(WRITE, tree, page, sector, 1939 iosize, page_offset, bdev, 1940 &epd->bio, max_nr, 1941 end_bio_extent_writepage); 1942 if (ret) 1943 SetPageError(page); 1944 } 1945 cur = cur + iosize; 1946 page_offset += iosize; 1947 nr++; 1948 } 1949 done: 1950 if (nr == 0) { 1951 /* make sure the mapping tag for page dirty gets cleared */ 1952 set_page_writeback(page); 1953 end_page_writeback(page); 1954 } 1955 unlock_extent(tree, start, page_end, GFP_NOFS); 1956 unlock_page(page); 1957 return 0; 1958 } 1959 1960 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18) 1961 1962 /* Taken directly from 2.6.23 for 2.6.18 back port */ 1963 typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, 1964 void *data); 1965 1966 /** 1967 * write_cache_pages - walk the list of dirty pages of the given address space 1968 * and write all of them. 1969 * @mapping: address space structure to write 1970 * @wbc: subtract the number of written pages from *@wbc->nr_to_write 1971 * @writepage: function called for each page 1972 * @data: data passed to writepage function 1973 * 1974 * If a page is already under I/O, write_cache_pages() skips it, even 1975 * if it's dirty. This is desirable behaviour for memory-cleaning writeback, 1976 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync() 1977 * and msync() need to guarantee that all the data which was dirty at the time 1978 * the call was made get new I/O started against them. If wbc->sync_mode is 1979 * WB_SYNC_ALL then we were called for data integrity and we must wait for 1980 * existing IO to complete. 1981 */ 1982 static int write_cache_pages(struct address_space *mapping, 1983 struct writeback_control *wbc, writepage_t writepage, 1984 void *data) 1985 { 1986 struct backing_dev_info *bdi = mapping->backing_dev_info; 1987 int ret = 0; 1988 int done = 0; 1989 struct pagevec pvec; 1990 int nr_pages; 1991 pgoff_t index; 1992 pgoff_t end; /* Inclusive */ 1993 int scanned = 0; 1994 int range_whole = 0; 1995 1996 if (wbc->nonblocking && bdi_write_congested(bdi)) { 1997 wbc->encountered_congestion = 1; 1998 return 0; 1999 } 2000 2001 pagevec_init(&pvec, 0); 2002 if (wbc->range_cyclic) { 2003 index = mapping->writeback_index; /* Start from prev offset */ 2004 end = -1; 2005 } else { 2006 index = wbc->range_start >> PAGE_CACHE_SHIFT; 2007 end = wbc->range_end >> PAGE_CACHE_SHIFT; 2008 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) 2009 range_whole = 1; 2010 scanned = 1; 2011 } 2012 retry: 2013 while (!done && (index <= end) && 2014 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, 2015 PAGECACHE_TAG_DIRTY, 2016 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { 2017 unsigned i; 2018 2019 scanned = 1; 2020 for (i = 0; i < nr_pages; i++) { 2021 struct page *page = pvec.pages[i]; 2022 2023 /* 2024 * At this point we hold neither mapping->tree_lock nor 2025 * lock on the page itself: the page may be truncated or 2026 * invalidated (changing page->mapping to NULL), or even 2027 * swizzled back from swapper_space to tmpfs file 2028 * mapping 2029 */ 2030 lock_page(page); 2031 2032 if (unlikely(page->mapping != mapping)) { 2033 unlock_page(page); 2034 continue; 2035 } 2036 2037 if (!wbc->range_cyclic && page->index > end) { 2038 done = 1; 2039 unlock_page(page); 2040 continue; 2041 } 2042 2043 if (wbc->sync_mode != WB_SYNC_NONE) 2044 wait_on_page_writeback(page); 2045 2046 if (PageWriteback(page) || 2047 !clear_page_dirty_for_io(page)) { 2048 unlock_page(page); 2049 continue; 2050 } 2051 2052 ret = (*writepage)(page, wbc, data); 2053 2054 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) { 2055 unlock_page(page); 2056 ret = 0; 2057 } 2058 if (ret || (--(wbc->nr_to_write) <= 0)) 2059 done = 1; 2060 if (wbc->nonblocking && bdi_write_congested(bdi)) { 2061 wbc->encountered_congestion = 1; 2062 done = 1; 2063 } 2064 } 2065 pagevec_release(&pvec); 2066 cond_resched(); 2067 } 2068 if (!scanned && !done) { 2069 /* 2070 * We hit the last page and there is more work to be done: wrap 2071 * back to the start of the file 2072 */ 2073 scanned = 1; 2074 index = 0; 2075 goto retry; 2076 } 2077 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) 2078 mapping->writeback_index = index; 2079 return ret; 2080 } 2081 #endif 2082 2083 int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 2084 get_extent_t *get_extent, 2085 struct writeback_control *wbc) 2086 { 2087 int ret; 2088 struct address_space *mapping = page->mapping; 2089 struct extent_page_data epd = { 2090 .bio = NULL, 2091 .tree = tree, 2092 .get_extent = get_extent, 2093 }; 2094 struct writeback_control wbc_writepages = { 2095 .bdi = wbc->bdi, 2096 .sync_mode = WB_SYNC_NONE, 2097 .older_than_this = NULL, 2098 .nr_to_write = 64, 2099 .range_start = page_offset(page) + PAGE_CACHE_SIZE, 2100 .range_end = (loff_t)-1, 2101 }; 2102 2103 2104 ret = __extent_writepage(page, wbc, &epd); 2105 2106 write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd); 2107 if (epd.bio) { 2108 submit_one_bio(WRITE, epd.bio); 2109 } 2110 return ret; 2111 } 2112 EXPORT_SYMBOL(extent_write_full_page); 2113 2114 2115 int extent_writepages(struct extent_map_tree *tree, 2116 struct address_space *mapping, 2117 get_extent_t *get_extent, 2118 struct writeback_control *wbc) 2119 { 2120 int ret = 0; 2121 struct extent_page_data epd = { 2122 .bio = NULL, 2123 .tree = tree, 2124 .get_extent = get_extent, 2125 }; 2126 2127 ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd); 2128 if (epd.bio) { 2129 submit_one_bio(WRITE, epd.bio); 2130 } 2131 return ret; 2132 } 2133 EXPORT_SYMBOL(extent_writepages); 2134 2135 int extent_readpages(struct extent_map_tree *tree, 2136 struct address_space *mapping, 2137 struct list_head *pages, unsigned nr_pages, 2138 get_extent_t get_extent) 2139 { 2140 struct bio *bio = NULL; 2141 unsigned page_idx; 2142 struct pagevec pvec; 2143 2144 pagevec_init(&pvec, 0); 2145 for (page_idx = 0; page_idx < nr_pages; page_idx++) { 2146 struct page *page = list_entry(pages->prev, struct page, lru); 2147 2148 prefetchw(&page->flags); 2149 list_del(&page->lru); 2150 /* 2151 * what we want to do here is call add_to_page_cache_lru, 2152 * but that isn't exported, so we reproduce it here 2153 */ 2154 if (!add_to_page_cache(page, mapping, 2155 page->index, GFP_KERNEL)) { 2156 2157 /* open coding of lru_cache_add, also not exported */ 2158 page_cache_get(page); 2159 if (!pagevec_add(&pvec, page)) 2160 __pagevec_lru_add(&pvec); 2161 __extent_read_full_page(tree, page, get_extent, &bio); 2162 } 2163 page_cache_release(page); 2164 } 2165 if (pagevec_count(&pvec)) 2166 __pagevec_lru_add(&pvec); 2167 BUG_ON(!list_empty(pages)); 2168 if (bio) 2169 submit_one_bio(READ, bio); 2170 return 0; 2171 } 2172 EXPORT_SYMBOL(extent_readpages); 2173 2174 /* 2175 * basic invalidatepage code, this waits on any locked or writeback 2176 * ranges corresponding to the page, and then deletes any extent state 2177 * records from the tree 2178 */ 2179 int extent_invalidatepage(struct extent_map_tree *tree, 2180 struct page *page, unsigned long offset) 2181 { 2182 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT); 2183 u64 end = start + PAGE_CACHE_SIZE - 1; 2184 size_t blocksize = page->mapping->host->i_sb->s_blocksize; 2185 2186 start += (offset + blocksize -1) & ~(blocksize - 1); 2187 if (start > end) 2188 return 0; 2189 2190 lock_extent(tree, start, end, GFP_NOFS); 2191 wait_on_extent_writeback(tree, start, end); 2192 clear_extent_bit(tree, start, end, 2193 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, 2194 1, 1, GFP_NOFS); 2195 return 0; 2196 } 2197 EXPORT_SYMBOL(extent_invalidatepage); 2198 2199 /* 2200 * simple commit_write call, set_range_dirty is used to mark both 2201 * the pages and the extent records as dirty 2202 */ 2203 int extent_commit_write(struct extent_map_tree *tree, 2204 struct inode *inode, struct page *page, 2205 unsigned from, unsigned to) 2206 { 2207 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; 2208 2209 set_page_extent_mapped(page); 2210 set_page_dirty(page); 2211 2212 if (pos > inode->i_size) { 2213 i_size_write(inode, pos); 2214 mark_inode_dirty(inode); 2215 } 2216 return 0; 2217 } 2218 EXPORT_SYMBOL(extent_commit_write); 2219 2220 int extent_prepare_write(struct extent_map_tree *tree, 2221 struct inode *inode, struct page *page, 2222 unsigned from, unsigned to, get_extent_t *get_extent) 2223 { 2224 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 2225 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 2226 u64 block_start; 2227 u64 orig_block_start; 2228 u64 block_end; 2229 u64 cur_end; 2230 struct extent_map *em; 2231 unsigned blocksize = 1 << inode->i_blkbits; 2232 size_t page_offset = 0; 2233 size_t block_off_start; 2234 size_t block_off_end; 2235 int err = 0; 2236 int iocount = 0; 2237 int ret = 0; 2238 int isnew; 2239 2240 set_page_extent_mapped(page); 2241 2242 block_start = (page_start + from) & ~((u64)blocksize - 1); 2243 block_end = (page_start + to - 1) | (blocksize - 1); 2244 orig_block_start = block_start; 2245 2246 lock_extent(tree, page_start, page_end, GFP_NOFS); 2247 while(block_start <= block_end) { 2248 em = get_extent(inode, page, page_offset, block_start, 2249 block_end, 1); 2250 if (IS_ERR(em) || !em) { 2251 goto err; 2252 } 2253 cur_end = min(block_end, em->end); 2254 block_off_start = block_start & (PAGE_CACHE_SIZE - 1); 2255 block_off_end = block_off_start + blocksize; 2256 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS); 2257 2258 if (!PageUptodate(page) && isnew && 2259 (block_off_end > to || block_off_start < from)) { 2260 void *kaddr; 2261 2262 kaddr = kmap_atomic(page, KM_USER0); 2263 if (block_off_end > to) 2264 memset(kaddr + to, 0, block_off_end - to); 2265 if (block_off_start < from) 2266 memset(kaddr + block_off_start, 0, 2267 from - block_off_start); 2268 flush_dcache_page(page); 2269 kunmap_atomic(kaddr, KM_USER0); 2270 } 2271 if ((em->block_start != EXTENT_MAP_HOLE && 2272 em->block_start != EXTENT_MAP_INLINE) && 2273 !isnew && !PageUptodate(page) && 2274 (block_off_end > to || block_off_start < from) && 2275 !test_range_bit(tree, block_start, cur_end, 2276 EXTENT_UPTODATE, 1)) { 2277 u64 sector; 2278 u64 extent_offset = block_start - em->start; 2279 size_t iosize; 2280 sector = (em->block_start + extent_offset) >> 9; 2281 iosize = (cur_end - block_start + blocksize) & 2282 ~((u64)blocksize - 1); 2283 /* 2284 * we've already got the extent locked, but we 2285 * need to split the state such that our end_bio 2286 * handler can clear the lock. 2287 */ 2288 set_extent_bit(tree, block_start, 2289 block_start + iosize - 1, 2290 EXTENT_LOCKED, 0, NULL, GFP_NOFS); 2291 ret = submit_extent_page(READ, tree, page, 2292 sector, iosize, page_offset, em->bdev, 2293 NULL, 1, 2294 end_bio_extent_preparewrite); 2295 iocount++; 2296 block_start = block_start + iosize; 2297 } else { 2298 set_extent_uptodate(tree, block_start, cur_end, 2299 GFP_NOFS); 2300 unlock_extent(tree, block_start, cur_end, GFP_NOFS); 2301 block_start = cur_end + 1; 2302 } 2303 page_offset = block_start & (PAGE_CACHE_SIZE - 1); 2304 free_extent_map(em); 2305 } 2306 if (iocount) { 2307 wait_extent_bit(tree, orig_block_start, 2308 block_end, EXTENT_LOCKED); 2309 } 2310 check_page_uptodate(tree, page); 2311 err: 2312 /* FIXME, zero out newly allocated blocks on error */ 2313 return err; 2314 } 2315 EXPORT_SYMBOL(extent_prepare_write); 2316 2317 /* 2318 * a helper for releasepage. As long as there are no locked extents 2319 * in the range corresponding to the page, both state records and extent 2320 * map records are removed 2321 */ 2322 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) 2323 { 2324 struct extent_map *em; 2325 u64 start = (u64)page->index << PAGE_CACHE_SHIFT; 2326 u64 end = start + PAGE_CACHE_SIZE - 1; 2327 u64 orig_start = start; 2328 int ret = 1; 2329 2330 while (start <= end) { 2331 em = lookup_extent_mapping(tree, start, end); 2332 if (!em || IS_ERR(em)) 2333 break; 2334 if (!test_range_bit(tree, em->start, em->end, 2335 EXTENT_LOCKED, 0)) { 2336 remove_extent_mapping(tree, em); 2337 /* once for the rb tree */ 2338 free_extent_map(em); 2339 } 2340 start = em->end + 1; 2341 /* once for us */ 2342 free_extent_map(em); 2343 } 2344 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) 2345 ret = 0; 2346 else 2347 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, 2348 1, 1, GFP_NOFS); 2349 return ret; 2350 } 2351 EXPORT_SYMBOL(try_release_extent_mapping); 2352 2353 sector_t extent_bmap(struct address_space *mapping, sector_t iblock, 2354 get_extent_t *get_extent) 2355 { 2356 struct inode *inode = mapping->host; 2357 u64 start = iblock << inode->i_blkbits; 2358 u64 end = start + (1 << inode->i_blkbits) - 1; 2359 sector_t sector = 0; 2360 struct extent_map *em; 2361 2362 em = get_extent(inode, NULL, 0, start, end, 0); 2363 if (!em || IS_ERR(em)) 2364 return 0; 2365 2366 if (em->block_start == EXTENT_MAP_INLINE || 2367 em->block_start == EXTENT_MAP_HOLE) 2368 goto out; 2369 2370 sector = (em->block_start + start - em->start) >> inode->i_blkbits; 2371 out: 2372 free_extent_map(em); 2373 return sector; 2374 } 2375 2376 static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb) 2377 { 2378 if (list_empty(&eb->lru)) { 2379 extent_buffer_get(eb); 2380 list_add(&eb->lru, &tree->buffer_lru); 2381 tree->lru_size++; 2382 if (tree->lru_size >= BUFFER_LRU_MAX) { 2383 struct extent_buffer *rm; 2384 rm = list_entry(tree->buffer_lru.prev, 2385 struct extent_buffer, lru); 2386 tree->lru_size--; 2387 list_del_init(&rm->lru); 2388 free_extent_buffer(rm); 2389 } 2390 } else 2391 list_move(&eb->lru, &tree->buffer_lru); 2392 return 0; 2393 } 2394 static struct extent_buffer *find_lru(struct extent_map_tree *tree, 2395 u64 start, unsigned long len) 2396 { 2397 struct list_head *lru = &tree->buffer_lru; 2398 struct list_head *cur = lru->next; 2399 struct extent_buffer *eb; 2400 2401 if (list_empty(lru)) 2402 return NULL; 2403 2404 do { 2405 eb = list_entry(cur, struct extent_buffer, lru); 2406 if (eb->start == start && eb->len == len) { 2407 extent_buffer_get(eb); 2408 return eb; 2409 } 2410 cur = cur->next; 2411 } while (cur != lru); 2412 return NULL; 2413 } 2414 2415 static inline unsigned long num_extent_pages(u64 start, u64 len) 2416 { 2417 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - 2418 (start >> PAGE_CACHE_SHIFT); 2419 } 2420 2421 static inline struct page *extent_buffer_page(struct extent_buffer *eb, 2422 unsigned long i) 2423 { 2424 struct page *p; 2425 struct address_space *mapping; 2426 2427 if (i == 0) 2428 return eb->first_page; 2429 i += eb->start >> PAGE_CACHE_SHIFT; 2430 mapping = eb->first_page->mapping; 2431 read_lock_irq(&mapping->tree_lock); 2432 p = radix_tree_lookup(&mapping->page_tree, i); 2433 read_unlock_irq(&mapping->tree_lock); 2434 return p; 2435 } 2436 2437 static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, 2438 u64 start, 2439 unsigned long len, 2440 gfp_t mask) 2441 { 2442 struct extent_buffer *eb = NULL; 2443 2444 spin_lock(&tree->lru_lock); 2445 eb = find_lru(tree, start, len); 2446 spin_unlock(&tree->lru_lock); 2447 if (eb) { 2448 return eb; 2449 } 2450 2451 eb = kmem_cache_zalloc(extent_buffer_cache, mask); 2452 INIT_LIST_HEAD(&eb->lru); 2453 eb->start = start; 2454 eb->len = len; 2455 atomic_set(&eb->refs, 1); 2456 2457 return eb; 2458 } 2459 2460 static void __free_extent_buffer(struct extent_buffer *eb) 2461 { 2462 kmem_cache_free(extent_buffer_cache, eb); 2463 } 2464 2465 struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 2466 u64 start, unsigned long len, 2467 struct page *page0, 2468 gfp_t mask) 2469 { 2470 unsigned long num_pages = num_extent_pages(start, len); 2471 unsigned long i; 2472 unsigned long index = start >> PAGE_CACHE_SHIFT; 2473 struct extent_buffer *eb; 2474 struct page *p; 2475 struct address_space *mapping = tree->mapping; 2476 int uptodate = 1; 2477 2478 eb = __alloc_extent_buffer(tree, start, len, mask); 2479 if (!eb || IS_ERR(eb)) 2480 return NULL; 2481 2482 if (eb->flags & EXTENT_BUFFER_FILLED) 2483 goto lru_add; 2484 2485 if (page0) { 2486 eb->first_page = page0; 2487 i = 1; 2488 index++; 2489 page_cache_get(page0); 2490 mark_page_accessed(page0); 2491 set_page_extent_mapped(page0); 2492 WARN_ON(!PageUptodate(page0)); 2493 set_page_private(page0, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2494 len << 2); 2495 } else { 2496 i = 0; 2497 } 2498 for (; i < num_pages; i++, index++) { 2499 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM); 2500 if (!p) { 2501 WARN_ON(1); 2502 goto fail; 2503 } 2504 set_page_extent_mapped(p); 2505 mark_page_accessed(p); 2506 if (i == 0) { 2507 eb->first_page = p; 2508 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2509 len << 2); 2510 } else { 2511 set_page_private(p, EXTENT_PAGE_PRIVATE); 2512 } 2513 if (!PageUptodate(p)) 2514 uptodate = 0; 2515 unlock_page(p); 2516 } 2517 if (uptodate) 2518 eb->flags |= EXTENT_UPTODATE; 2519 eb->flags |= EXTENT_BUFFER_FILLED; 2520 2521 lru_add: 2522 spin_lock(&tree->lru_lock); 2523 add_lru(tree, eb); 2524 spin_unlock(&tree->lru_lock); 2525 return eb; 2526 2527 fail: 2528 spin_lock(&tree->lru_lock); 2529 list_del_init(&eb->lru); 2530 spin_unlock(&tree->lru_lock); 2531 if (!atomic_dec_and_test(&eb->refs)) 2532 return NULL; 2533 for (index = 1; index < i; index++) { 2534 page_cache_release(extent_buffer_page(eb, index)); 2535 } 2536 if (i > 0) 2537 page_cache_release(extent_buffer_page(eb, 0)); 2538 __free_extent_buffer(eb); 2539 return NULL; 2540 } 2541 EXPORT_SYMBOL(alloc_extent_buffer); 2542 2543 struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 2544 u64 start, unsigned long len, 2545 gfp_t mask) 2546 { 2547 unsigned long num_pages = num_extent_pages(start, len); 2548 unsigned long i; 2549 unsigned long index = start >> PAGE_CACHE_SHIFT; 2550 struct extent_buffer *eb; 2551 struct page *p; 2552 struct address_space *mapping = tree->mapping; 2553 int uptodate = 1; 2554 2555 eb = __alloc_extent_buffer(tree, start, len, mask); 2556 if (!eb || IS_ERR(eb)) 2557 return NULL; 2558 2559 if (eb->flags & EXTENT_BUFFER_FILLED) 2560 goto lru_add; 2561 2562 for (i = 0; i < num_pages; i++, index++) { 2563 p = find_lock_page(mapping, index); 2564 if (!p) { 2565 goto fail; 2566 } 2567 set_page_extent_mapped(p); 2568 mark_page_accessed(p); 2569 2570 if (i == 0) { 2571 eb->first_page = p; 2572 set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2573 len << 2); 2574 } else { 2575 set_page_private(p, EXTENT_PAGE_PRIVATE); 2576 } 2577 2578 if (!PageUptodate(p)) 2579 uptodate = 0; 2580 unlock_page(p); 2581 } 2582 if (uptodate) 2583 eb->flags |= EXTENT_UPTODATE; 2584 eb->flags |= EXTENT_BUFFER_FILLED; 2585 2586 lru_add: 2587 spin_lock(&tree->lru_lock); 2588 add_lru(tree, eb); 2589 spin_unlock(&tree->lru_lock); 2590 return eb; 2591 fail: 2592 spin_lock(&tree->lru_lock); 2593 list_del_init(&eb->lru); 2594 spin_unlock(&tree->lru_lock); 2595 if (!atomic_dec_and_test(&eb->refs)) 2596 return NULL; 2597 for (index = 1; index < i; index++) { 2598 page_cache_release(extent_buffer_page(eb, index)); 2599 } 2600 if (i > 0) 2601 page_cache_release(extent_buffer_page(eb, 0)); 2602 __free_extent_buffer(eb); 2603 return NULL; 2604 } 2605 EXPORT_SYMBOL(find_extent_buffer); 2606 2607 void free_extent_buffer(struct extent_buffer *eb) 2608 { 2609 unsigned long i; 2610 unsigned long num_pages; 2611 2612 if (!eb) 2613 return; 2614 2615 if (!atomic_dec_and_test(&eb->refs)) 2616 return; 2617 2618 WARN_ON(!list_empty(&eb->lru)); 2619 num_pages = num_extent_pages(eb->start, eb->len); 2620 2621 for (i = 1; i < num_pages; i++) { 2622 page_cache_release(extent_buffer_page(eb, i)); 2623 } 2624 page_cache_release(extent_buffer_page(eb, 0)); 2625 __free_extent_buffer(eb); 2626 } 2627 EXPORT_SYMBOL(free_extent_buffer); 2628 2629 int clear_extent_buffer_dirty(struct extent_map_tree *tree, 2630 struct extent_buffer *eb) 2631 { 2632 int set; 2633 unsigned long i; 2634 unsigned long num_pages; 2635 struct page *page; 2636 2637 u64 start = eb->start; 2638 u64 end = start + eb->len - 1; 2639 2640 set = clear_extent_dirty(tree, start, end, GFP_NOFS); 2641 num_pages = num_extent_pages(eb->start, eb->len); 2642 2643 for (i = 0; i < num_pages; i++) { 2644 page = extent_buffer_page(eb, i); 2645 lock_page(page); 2646 /* 2647 * if we're on the last page or the first page and the 2648 * block isn't aligned on a page boundary, do extra checks 2649 * to make sure we don't clean page that is partially dirty 2650 */ 2651 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2652 ((i == num_pages - 1) && 2653 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2654 start = (u64)page->index << PAGE_CACHE_SHIFT; 2655 end = start + PAGE_CACHE_SIZE - 1; 2656 if (test_range_bit(tree, start, end, 2657 EXTENT_DIRTY, 0)) { 2658 unlock_page(page); 2659 continue; 2660 } 2661 } 2662 clear_page_dirty_for_io(page); 2663 write_lock_irq(&page->mapping->tree_lock); 2664 if (!PageDirty(page)) { 2665 radix_tree_tag_clear(&page->mapping->page_tree, 2666 page_index(page), 2667 PAGECACHE_TAG_DIRTY); 2668 } 2669 write_unlock_irq(&page->mapping->tree_lock); 2670 unlock_page(page); 2671 } 2672 return 0; 2673 } 2674 EXPORT_SYMBOL(clear_extent_buffer_dirty); 2675 2676 int wait_on_extent_buffer_writeback(struct extent_map_tree *tree, 2677 struct extent_buffer *eb) 2678 { 2679 return wait_on_extent_writeback(tree, eb->start, 2680 eb->start + eb->len - 1); 2681 } 2682 EXPORT_SYMBOL(wait_on_extent_buffer_writeback); 2683 2684 int set_extent_buffer_dirty(struct extent_map_tree *tree, 2685 struct extent_buffer *eb) 2686 { 2687 unsigned long i; 2688 unsigned long num_pages; 2689 2690 num_pages = num_extent_pages(eb->start, eb->len); 2691 for (i = 0; i < num_pages; i++) { 2692 struct page *page = extent_buffer_page(eb, i); 2693 /* writepage may need to do something special for the 2694 * first page, we have to make sure page->private is 2695 * properly set. releasepage may drop page->private 2696 * on us if the page isn't already dirty. 2697 */ 2698 if (i == 0) { 2699 lock_page(page); 2700 set_page_private(page, 2701 EXTENT_PAGE_PRIVATE_FIRST_PAGE | 2702 eb->len << 2); 2703 } 2704 __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); 2705 if (i == 0) 2706 unlock_page(page); 2707 } 2708 return set_extent_dirty(tree, eb->start, 2709 eb->start + eb->len - 1, GFP_NOFS); 2710 } 2711 EXPORT_SYMBOL(set_extent_buffer_dirty); 2712 2713 int set_extent_buffer_uptodate(struct extent_map_tree *tree, 2714 struct extent_buffer *eb) 2715 { 2716 unsigned long i; 2717 struct page *page; 2718 unsigned long num_pages; 2719 2720 num_pages = num_extent_pages(eb->start, eb->len); 2721 2722 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, 2723 GFP_NOFS); 2724 for (i = 0; i < num_pages; i++) { 2725 page = extent_buffer_page(eb, i); 2726 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || 2727 ((i == num_pages - 1) && 2728 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { 2729 check_page_uptodate(tree, page); 2730 continue; 2731 } 2732 SetPageUptodate(page); 2733 } 2734 return 0; 2735 } 2736 EXPORT_SYMBOL(set_extent_buffer_uptodate); 2737 2738 int extent_buffer_uptodate(struct extent_map_tree *tree, 2739 struct extent_buffer *eb) 2740 { 2741 if (eb->flags & EXTENT_UPTODATE) 2742 return 1; 2743 return test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2744 EXTENT_UPTODATE, 1); 2745 } 2746 EXPORT_SYMBOL(extent_buffer_uptodate); 2747 2748 int read_extent_buffer_pages(struct extent_map_tree *tree, 2749 struct extent_buffer *eb, 2750 u64 start, 2751 int wait) 2752 { 2753 unsigned long i; 2754 unsigned long start_i; 2755 struct page *page; 2756 int err; 2757 int ret = 0; 2758 unsigned long num_pages; 2759 2760 if (eb->flags & EXTENT_UPTODATE) 2761 return 0; 2762 2763 if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, 2764 EXTENT_UPTODATE, 1)) { 2765 return 0; 2766 } 2767 2768 if (start) { 2769 WARN_ON(start < eb->start); 2770 start_i = (start >> PAGE_CACHE_SHIFT) - 2771 (eb->start >> PAGE_CACHE_SHIFT); 2772 } else { 2773 start_i = 0; 2774 } 2775 2776 num_pages = num_extent_pages(eb->start, eb->len); 2777 for (i = start_i; i < num_pages; i++) { 2778 page = extent_buffer_page(eb, i); 2779 if (PageUptodate(page)) { 2780 continue; 2781 } 2782 if (!wait) { 2783 if (TestSetPageLocked(page)) { 2784 continue; 2785 } 2786 } else { 2787 lock_page(page); 2788 } 2789 if (!PageUptodate(page)) { 2790 err = page->mapping->a_ops->readpage(NULL, page); 2791 if (err) { 2792 ret = err; 2793 } 2794 } else { 2795 unlock_page(page); 2796 } 2797 } 2798 2799 if (ret || !wait) { 2800 return ret; 2801 } 2802 2803 for (i = start_i; i < num_pages; i++) { 2804 page = extent_buffer_page(eb, i); 2805 wait_on_page_locked(page); 2806 if (!PageUptodate(page)) { 2807 ret = -EIO; 2808 } 2809 } 2810 if (!ret) 2811 eb->flags |= EXTENT_UPTODATE; 2812 return ret; 2813 } 2814 EXPORT_SYMBOL(read_extent_buffer_pages); 2815 2816 void read_extent_buffer(struct extent_buffer *eb, void *dstv, 2817 unsigned long start, 2818 unsigned long len) 2819 { 2820 size_t cur; 2821 size_t offset; 2822 struct page *page; 2823 char *kaddr; 2824 char *dst = (char *)dstv; 2825 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2826 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2827 unsigned long num_pages = num_extent_pages(eb->start, eb->len); 2828 2829 WARN_ON(start > eb->len); 2830 WARN_ON(start + len > eb->start + eb->len); 2831 2832 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2833 2834 while(len > 0) { 2835 page = extent_buffer_page(eb, i); 2836 if (!PageUptodate(page)) { 2837 printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); 2838 WARN_ON(1); 2839 } 2840 WARN_ON(!PageUptodate(page)); 2841 2842 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2843 kaddr = kmap_atomic(page, KM_USER1); 2844 memcpy(dst, kaddr + offset, cur); 2845 kunmap_atomic(kaddr, KM_USER1); 2846 2847 dst += cur; 2848 len -= cur; 2849 offset = 0; 2850 i++; 2851 } 2852 } 2853 EXPORT_SYMBOL(read_extent_buffer); 2854 2855 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, 2856 unsigned long min_len, char **token, char **map, 2857 unsigned long *map_start, 2858 unsigned long *map_len, int km) 2859 { 2860 size_t offset = start & (PAGE_CACHE_SIZE - 1); 2861 char *kaddr; 2862 struct page *p; 2863 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2864 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2865 unsigned long end_i = (start_offset + start + min_len - 1) >> 2866 PAGE_CACHE_SHIFT; 2867 2868 if (i != end_i) 2869 return -EINVAL; 2870 2871 if (i == 0) { 2872 offset = start_offset; 2873 *map_start = 0; 2874 } else { 2875 offset = 0; 2876 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset; 2877 } 2878 if (start + min_len > eb->len) { 2879 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); 2880 WARN_ON(1); 2881 } 2882 2883 p = extent_buffer_page(eb, i); 2884 WARN_ON(!PageUptodate(p)); 2885 kaddr = kmap_atomic(p, km); 2886 *token = kaddr; 2887 *map = kaddr + offset; 2888 *map_len = PAGE_CACHE_SIZE - offset; 2889 return 0; 2890 } 2891 EXPORT_SYMBOL(map_private_extent_buffer); 2892 2893 int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 2894 unsigned long min_len, 2895 char **token, char **map, 2896 unsigned long *map_start, 2897 unsigned long *map_len, int km) 2898 { 2899 int err; 2900 int save = 0; 2901 if (eb->map_token) { 2902 unmap_extent_buffer(eb, eb->map_token, km); 2903 eb->map_token = NULL; 2904 save = 1; 2905 } 2906 err = map_private_extent_buffer(eb, start, min_len, token, map, 2907 map_start, map_len, km); 2908 if (!err && save) { 2909 eb->map_token = *token; 2910 eb->kaddr = *map; 2911 eb->map_start = *map_start; 2912 eb->map_len = *map_len; 2913 } 2914 return err; 2915 } 2916 EXPORT_SYMBOL(map_extent_buffer); 2917 2918 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) 2919 { 2920 kunmap_atomic(token, km); 2921 } 2922 EXPORT_SYMBOL(unmap_extent_buffer); 2923 2924 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 2925 unsigned long start, 2926 unsigned long len) 2927 { 2928 size_t cur; 2929 size_t offset; 2930 struct page *page; 2931 char *kaddr; 2932 char *ptr = (char *)ptrv; 2933 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2934 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2935 int ret = 0; 2936 2937 WARN_ON(start > eb->len); 2938 WARN_ON(start + len > eb->start + eb->len); 2939 2940 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2941 2942 while(len > 0) { 2943 page = extent_buffer_page(eb, i); 2944 WARN_ON(!PageUptodate(page)); 2945 2946 cur = min(len, (PAGE_CACHE_SIZE - offset)); 2947 2948 kaddr = kmap_atomic(page, KM_USER0); 2949 ret = memcmp(ptr, kaddr + offset, cur); 2950 kunmap_atomic(kaddr, KM_USER0); 2951 if (ret) 2952 break; 2953 2954 ptr += cur; 2955 len -= cur; 2956 offset = 0; 2957 i++; 2958 } 2959 return ret; 2960 } 2961 EXPORT_SYMBOL(memcmp_extent_buffer); 2962 2963 void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 2964 unsigned long start, unsigned long len) 2965 { 2966 size_t cur; 2967 size_t offset; 2968 struct page *page; 2969 char *kaddr; 2970 char *src = (char *)srcv; 2971 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 2972 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 2973 2974 WARN_ON(start > eb->len); 2975 WARN_ON(start + len > eb->start + eb->len); 2976 2977 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 2978 2979 while(len > 0) { 2980 page = extent_buffer_page(eb, i); 2981 WARN_ON(!PageUptodate(page)); 2982 2983 cur = min(len, PAGE_CACHE_SIZE - offset); 2984 kaddr = kmap_atomic(page, KM_USER1); 2985 memcpy(kaddr + offset, src, cur); 2986 kunmap_atomic(kaddr, KM_USER1); 2987 2988 src += cur; 2989 len -= cur; 2990 offset = 0; 2991 i++; 2992 } 2993 } 2994 EXPORT_SYMBOL(write_extent_buffer); 2995 2996 void memset_extent_buffer(struct extent_buffer *eb, char c, 2997 unsigned long start, unsigned long len) 2998 { 2999 size_t cur; 3000 size_t offset; 3001 struct page *page; 3002 char *kaddr; 3003 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); 3004 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; 3005 3006 WARN_ON(start > eb->len); 3007 WARN_ON(start + len > eb->start + eb->len); 3008 3009 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1); 3010 3011 while(len > 0) { 3012 page = extent_buffer_page(eb, i); 3013 WARN_ON(!PageUptodate(page)); 3014 3015 cur = min(len, PAGE_CACHE_SIZE - offset); 3016 kaddr = kmap_atomic(page, KM_USER0); 3017 memset(kaddr + offset, c, cur); 3018 kunmap_atomic(kaddr, KM_USER0); 3019 3020 len -= cur; 3021 offset = 0; 3022 i++; 3023 } 3024 } 3025 EXPORT_SYMBOL(memset_extent_buffer); 3026 3027 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 3028 unsigned long dst_offset, unsigned long src_offset, 3029 unsigned long len) 3030 { 3031 u64 dst_len = dst->len; 3032 size_t cur; 3033 size_t offset; 3034 struct page *page; 3035 char *kaddr; 3036 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 3037 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 3038 3039 WARN_ON(src->len != dst_len); 3040 3041 offset = (start_offset + dst_offset) & 3042 ((unsigned long)PAGE_CACHE_SIZE - 1); 3043 3044 while(len > 0) { 3045 page = extent_buffer_page(dst, i); 3046 WARN_ON(!PageUptodate(page)); 3047 3048 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset)); 3049 3050 kaddr = kmap_atomic(page, KM_USER0); 3051 read_extent_buffer(src, kaddr + offset, src_offset, cur); 3052 kunmap_atomic(kaddr, KM_USER0); 3053 3054 src_offset += cur; 3055 len -= cur; 3056 offset = 0; 3057 i++; 3058 } 3059 } 3060 EXPORT_SYMBOL(copy_extent_buffer); 3061 3062 static void move_pages(struct page *dst_page, struct page *src_page, 3063 unsigned long dst_off, unsigned long src_off, 3064 unsigned long len) 3065 { 3066 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 3067 if (dst_page == src_page) { 3068 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len); 3069 } else { 3070 char *src_kaddr = kmap_atomic(src_page, KM_USER1); 3071 char *p = dst_kaddr + dst_off + len; 3072 char *s = src_kaddr + src_off + len; 3073 3074 while (len--) 3075 *--p = *--s; 3076 3077 kunmap_atomic(src_kaddr, KM_USER1); 3078 } 3079 kunmap_atomic(dst_kaddr, KM_USER0); 3080 } 3081 3082 static void copy_pages(struct page *dst_page, struct page *src_page, 3083 unsigned long dst_off, unsigned long src_off, 3084 unsigned long len) 3085 { 3086 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0); 3087 char *src_kaddr; 3088 3089 if (dst_page != src_page) 3090 src_kaddr = kmap_atomic(src_page, KM_USER1); 3091 else 3092 src_kaddr = dst_kaddr; 3093 3094 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); 3095 kunmap_atomic(dst_kaddr, KM_USER0); 3096 if (dst_page != src_page) 3097 kunmap_atomic(src_kaddr, KM_USER1); 3098 } 3099 3100 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 3101 unsigned long src_offset, unsigned long len) 3102 { 3103 size_t cur; 3104 size_t dst_off_in_page; 3105 size_t src_off_in_page; 3106 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 3107 unsigned long dst_i; 3108 unsigned long src_i; 3109 3110 if (src_offset + len > dst->len) { 3111 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 3112 src_offset, len, dst->len); 3113 BUG_ON(1); 3114 } 3115 if (dst_offset + len > dst->len) { 3116 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 3117 dst_offset, len, dst->len); 3118 BUG_ON(1); 3119 } 3120 3121 while(len > 0) { 3122 dst_off_in_page = (start_offset + dst_offset) & 3123 ((unsigned long)PAGE_CACHE_SIZE - 1); 3124 src_off_in_page = (start_offset + src_offset) & 3125 ((unsigned long)PAGE_CACHE_SIZE - 1); 3126 3127 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT; 3128 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT; 3129 3130 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - 3131 src_off_in_page)); 3132 cur = min_t(unsigned long, cur, 3133 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page)); 3134 3135 copy_pages(extent_buffer_page(dst, dst_i), 3136 extent_buffer_page(dst, src_i), 3137 dst_off_in_page, src_off_in_page, cur); 3138 3139 src_offset += cur; 3140 dst_offset += cur; 3141 len -= cur; 3142 } 3143 } 3144 EXPORT_SYMBOL(memcpy_extent_buffer); 3145 3146 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 3147 unsigned long src_offset, unsigned long len) 3148 { 3149 size_t cur; 3150 size_t dst_off_in_page; 3151 size_t src_off_in_page; 3152 unsigned long dst_end = dst_offset + len - 1; 3153 unsigned long src_end = src_offset + len - 1; 3154 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1); 3155 unsigned long dst_i; 3156 unsigned long src_i; 3157 3158 if (src_offset + len > dst->len) { 3159 printk("memmove bogus src_offset %lu move len %lu len %lu\n", 3160 src_offset, len, dst->len); 3161 BUG_ON(1); 3162 } 3163 if (dst_offset + len > dst->len) { 3164 printk("memmove bogus dst_offset %lu move len %lu len %lu\n", 3165 dst_offset, len, dst->len); 3166 BUG_ON(1); 3167 } 3168 if (dst_offset < src_offset) { 3169 memcpy_extent_buffer(dst, dst_offset, src_offset, len); 3170 return; 3171 } 3172 while(len > 0) { 3173 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT; 3174 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT; 3175 3176 dst_off_in_page = (start_offset + dst_end) & 3177 ((unsigned long)PAGE_CACHE_SIZE - 1); 3178 src_off_in_page = (start_offset + src_end) & 3179 ((unsigned long)PAGE_CACHE_SIZE - 1); 3180 3181 cur = min_t(unsigned long, len, src_off_in_page + 1); 3182 cur = min(cur, dst_off_in_page + 1); 3183 move_pages(extent_buffer_page(dst, dst_i), 3184 extent_buffer_page(dst, src_i), 3185 dst_off_in_page - cur + 1, 3186 src_off_in_page - cur + 1, cur); 3187 3188 dst_end -= cur; 3189 src_end -= cur; 3190 len -= cur; 3191 } 3192 } 3193 EXPORT_SYMBOL(memmove_extent_buffer); 3194