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