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Btrfs: Data ordered fixes
[linux-2.6-block.git] / fs / btrfs / extent_io.c
CommitLineData
d1310b2e
CM		 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_io.h"
16#include "extent_map.h"
17
18/* temporary define until extent_map moves out of btrfs */
19struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
20 unsigned long extra_flags,
21 void (*ctor)(void *, struct kmem_cache *,
22 unsigned long));
23
24static struct kmem_cache *extent_state_cache;
25static struct kmem_cache *extent_buffer_cache;
26
27static LIST_HEAD(buffers);
28static LIST_HEAD(states);
2d2ae547 29static spinlock_t leak_lock = SPIN_LOCK_UNLOCKED;
d1310b2e 30
d1310b2e
CM		 31#define BUFFER_LRU_MAX 64
32
33struct tree_entry {
34 u64 start;
35 u64 end;
d1310b2e
CM		 36 struct rb_node rb_node;
37};
38
39struct extent_page_data {
40 struct bio *bio;
41 struct extent_io_tree *tree;
42 get_extent_t *get_extent;
43};
44
45int __init extent_io_init(void)
46{
47 extent_state_cache = btrfs_cache_create("extent_state",
48 sizeof(struct extent_state), 0,
49 NULL);
50 if (!extent_state_cache)
51 return -ENOMEM;
52
53 extent_buffer_cache = btrfs_cache_create("extent_buffers",
54 sizeof(struct extent_buffer), 0,
55 NULL);
56 if (!extent_buffer_cache)
57 goto free_state_cache;
58 return 0;
59
60free_state_cache:
61 kmem_cache_destroy(extent_state_cache);
62 return -ENOMEM;
63}
64
65void extent_io_exit(void)
66{
67 struct extent_state *state;
2d2ae547 68 struct extent_buffer *eb;
d1310b2e
CM		 69
70 while (!list_empty(&states)) {
2d2ae547 71 state = list_entry(states.next, struct extent_state, leak_list);
70dec807 72 printk("state leak: start %Lu end %Lu state %lu in tree %p refs %d\n", state->start, state->end, state->state, state->tree, atomic_read(&state->refs));
2d2ae547 73 list_del(&state->leak_list);
d1310b2e
CM		 74 kmem_cache_free(extent_state_cache, state);
75
76 }
77
2d2ae547
CM		 78 while (!list_empty(&buffers)) {
79 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
80 printk("buffer leak start %Lu len %lu refs %d\n", eb->start, eb->len, atomic_read(&eb->refs));
81 list_del(&eb->leak_list);
82 kmem_cache_free(extent_buffer_cache, eb);
83 }
d1310b2e
CM		 84 if (extent_state_cache)
85 kmem_cache_destroy(extent_state_cache);
86 if (extent_buffer_cache)
87 kmem_cache_destroy(extent_buffer_cache);
88}
89
90void extent_io_tree_init(struct extent_io_tree *tree,
91 struct address_space *mapping, gfp_t mask)
92{
93 tree->state.rb_node = NULL;
94 tree->ops = NULL;
95 tree->dirty_bytes = 0;
70dec807 96 spin_lock_init(&tree->lock);
d1310b2e
CM		 97 spin_lock_init(&tree->lru_lock);
98 tree->mapping = mapping;
99 INIT_LIST_HEAD(&tree->buffer_lru);
100 tree->lru_size = 0;
80ea96b1 101 tree->last = NULL;
d1310b2e
CM		 102}
103EXPORT_SYMBOL(extent_io_tree_init);
104
105void extent_io_tree_empty_lru(struct extent_io_tree *tree)
106{
107 struct extent_buffer *eb;
108 while(!list_empty(&tree->buffer_lru)) {
109 eb = list_entry(tree->buffer_lru.next, struct extent_buffer,
110 lru);
111 list_del_init(&eb->lru);
112 free_extent_buffer(eb);
113 }
114}
115EXPORT_SYMBOL(extent_io_tree_empty_lru);
116
117struct extent_state *alloc_extent_state(gfp_t mask)
118{
119 struct extent_state *state;
2d2ae547 120 unsigned long flags;
d1310b2e
CM		 121
122 state = kmem_cache_alloc(extent_state_cache, mask);
2b114d1d 123 if (!state)
d1310b2e
CM		 124 return state;
125 state->state = 0;
d1310b2e 126 state->private = 0;
70dec807 127 state->tree = NULL;
2d2ae547
CM		 128 spin_lock_irqsave(&leak_lock, flags);
129 list_add(&state->leak_list, &states);
130 spin_unlock_irqrestore(&leak_lock, flags);
d1310b2e
CM		 131
132 atomic_set(&state->refs, 1);
133 init_waitqueue_head(&state->wq);
134 return state;
135}
136EXPORT_SYMBOL(alloc_extent_state);
137
138void free_extent_state(struct extent_state *state)
139{
d1310b2e
CM		 140 if (!state)
141 return;
142 if (atomic_dec_and_test(&state->refs)) {
2d2ae547 143 unsigned long flags;
70dec807 144 WARN_ON(state->tree);
2d2ae547
CM		 145 spin_lock_irqsave(&leak_lock, flags);
146 list_del(&state->leak_list);
147 spin_unlock_irqrestore(&leak_lock, flags);
d1310b2e
CM		 148 kmem_cache_free(extent_state_cache, state);
149 }
150}
151EXPORT_SYMBOL(free_extent_state);
152
153static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
154 struct rb_node *node)
155{
156 struct rb_node ** p = &root->rb_node;
157 struct rb_node * parent = NULL;
158 struct tree_entry *entry;
159
160 while(*p) {
161 parent = *p;
162 entry = rb_entry(parent, struct tree_entry, rb_node);
163
164 if (offset < entry->start)
165 p = &(*p)->rb_left;
166 else if (offset > entry->end)
167 p = &(*p)->rb_right;
168 else
169 return parent;
170 }
171
172 entry = rb_entry(node, struct tree_entry, rb_node);
d1310b2e
CM		 173 rb_link_node(node, parent, p);
174 rb_insert_color(node, root);
175 return NULL;
176}
177
80ea96b1 178static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
d1310b2e
CM		 179 struct rb_node **prev_ret,
180 struct rb_node **next_ret)
181{
80ea96b1 182 struct rb_root *root = &tree->state;
d1310b2e
CM		 183 struct rb_node * n = root->rb_node;
184 struct rb_node *prev = NULL;
185 struct rb_node *orig_prev = NULL;
186 struct tree_entry *entry;
187 struct tree_entry *prev_entry = NULL;
188
80ea96b1
CM		 189 if (tree->last) {
190 struct extent_state *state;
191 state = tree->last;
192 if (state->start <= offset && offset <= state->end)
193 return &tree->last->rb_node;
194 }
d1310b2e
CM		 195 while(n) {
196 entry = rb_entry(n, struct tree_entry, rb_node);
197 prev = n;
198 prev_entry = entry;
199
200 if (offset < entry->start)
201 n = n->rb_left;
202 else if (offset > entry->end)
203 n = n->rb_right;
80ea96b1
CM		 204 else {
205 tree->last = rb_entry(n, struct extent_state, rb_node);
d1310b2e 206 return n;
80ea96b1 207 }
d1310b2e
CM		 208 }
209
210 if (prev_ret) {
211 orig_prev = prev;
212 while(prev && offset > prev_entry->end) {
213 prev = rb_next(prev);
214 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
215 }
216 *prev_ret = prev;
217 prev = orig_prev;
218 }
219
220 if (next_ret) {
221 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
222 while(prev && offset < prev_entry->start) {
223 prev = rb_prev(prev);
224 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
225 }
226 *next_ret = prev;
227 }
228 return NULL;
229}
230
80ea96b1
CM		 231static inline struct rb_node *tree_search(struct extent_io_tree *tree,
232 u64 offset)
d1310b2e 233{
70dec807 234 struct rb_node *prev = NULL;
d1310b2e 235 struct rb_node *ret;
70dec807 236
80ea96b1
CM		 237 ret = __etree_search(tree, offset, &prev, NULL);
238 if (!ret) {
239 if (prev) {
240 tree->last = rb_entry(prev, struct extent_state,
241 rb_node);
242 }
d1310b2e 243 return prev;
80ea96b1 244 }
d1310b2e
CM		 245 return ret;
246}
247
248/*
249 * utility function to look for merge candidates inside a given range.
250 * Any extents with matching state are merged together into a single
251 * extent in the tree. Extents with EXTENT_IO in their state field
252 * are not merged because the end_io handlers need to be able to do
253 * operations on them without sleeping (or doing allocations/splits).
254 *
255 * This should be called with the tree lock held.
256 */
257static int merge_state(struct extent_io_tree *tree,
258 struct extent_state *state)
259{
260 struct extent_state *other;
261 struct rb_node *other_node;
262
263 if (state->state & EXTENT_IOBITS)
264 return 0;
265
266 other_node = rb_prev(&state->rb_node);
267 if (other_node) {
268 other = rb_entry(other_node, struct extent_state, rb_node);
269 if (other->end == state->start - 1 &&
270 other->state == state->state) {
271 state->start = other->start;
70dec807 272 other->tree = NULL;
80ea96b1 273 if (tree->last == other)
d7fc640e 274 tree->last = state;
d1310b2e
CM		 275 rb_erase(&other->rb_node, &tree->state);
276 free_extent_state(other);
277 }
278 }
279 other_node = rb_next(&state->rb_node);
280 if (other_node) {
281 other = rb_entry(other_node, struct extent_state, rb_node);
282 if (other->start == state->end + 1 &&
283 other->state == state->state) {
284 other->start = state->start;
70dec807 285 state->tree = NULL;
80ea96b1 286 if (tree->last == state)
d7fc640e 287 tree->last = other;
d1310b2e
CM		 288 rb_erase(&state->rb_node, &tree->state);
289 free_extent_state(state);
290 }
291 }
292 return 0;
293}
294
291d673e
CM		 295static void set_state_cb(struct extent_io_tree *tree,
296 struct extent_state *state,
297 unsigned long bits)
298{
299 if (tree->ops && tree->ops->set_bit_hook) {
300 tree->ops->set_bit_hook(tree->mapping->host, state->start,
b0c68f8b 301 state->end, state->state, bits);
291d673e
CM		 302 }
303}
304
305static void clear_state_cb(struct extent_io_tree *tree,
306 struct extent_state *state,
307 unsigned long bits)
308{
309 if (tree->ops && tree->ops->set_bit_hook) {
310 tree->ops->clear_bit_hook(tree->mapping->host, state->start,
b0c68f8b 311 state->end, state->state, bits);
291d673e
CM		 312 }
313}
314
d1310b2e
CM		 315/*
316 * insert an extent_state struct into the tree. 'bits' are set on the
317 * struct before it is inserted.
318 *
319 * This may return -EEXIST if the extent is already there, in which case the
320 * state struct is freed.
321 *
322 * The tree lock is not taken internally. This is a utility function and
323 * probably isn't what you want to call (see set/clear_extent_bit).
324 */
325static int insert_state(struct extent_io_tree *tree,
326 struct extent_state *state, u64 start, u64 end,
327 int bits)
328{
329 struct rb_node *node;
330
331 if (end < start) {
332 printk("end < start %Lu %Lu\n", end, start);
333 WARN_ON(1);
334 }
335 if (bits & EXTENT_DIRTY)
336 tree->dirty_bytes += end - start + 1;
b0c68f8b 337 set_state_cb(tree, state, bits);
d1310b2e
CM		 338 state->state |= bits;
339 state->start = start;
340 state->end = end;
341 node = tree_insert(&tree->state, end, &state->rb_node);
342 if (node) {
343 struct extent_state *found;
344 found = rb_entry(node, struct extent_state, rb_node);
345 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end);
346 free_extent_state(state);
347 return -EEXIST;
348 }
70dec807 349 state->tree = tree;
80ea96b1 350 tree->last = state;
d1310b2e
CM		 351 merge_state(tree, state);
352 return 0;
353}
354
355/*
356 * split a given extent state struct in two, inserting the preallocated
357 * struct 'prealloc' as the newly created second half. 'split' indicates an
358 * offset inside 'orig' where it should be split.
359 *
360 * Before calling,
361 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
362 * are two extent state structs in the tree:
363 * prealloc: [orig->start, split - 1]
364 * orig: [ split, orig->end ]
365 *
366 * The tree locks are not taken by this function. They need to be held
367 * by the caller.
368 */
369static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
370 struct extent_state *prealloc, u64 split)
371{
372 struct rb_node *node;
373 prealloc->start = orig->start;
374 prealloc->end = split - 1;
375 prealloc->state = orig->state;
376 orig->start = split;
377
378 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
379 if (node) {
380 struct extent_state *found;
381 found = rb_entry(node, struct extent_state, rb_node);
382 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end);
383 free_extent_state(prealloc);
384 return -EEXIST;
385 }
70dec807 386 prealloc->tree = tree;
d1310b2e
CM		 387 return 0;
388}
389
390/*
391 * utility function to clear some bits in an extent state struct.
392 * it will optionally wake up any one waiting on this state (wake == 1), or
393 * forcibly remove the state from the tree (delete == 1).
394 *
395 * If no bits are set on the state struct after clearing things, the
396 * struct is freed and removed from the tree
397 */
398static int clear_state_bit(struct extent_io_tree *tree,
399 struct extent_state *state, int bits, int wake,
400 int delete)
401{
402 int ret = state->state & bits;
403
404 if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
405 u64 range = state->end - state->start + 1;
406 WARN_ON(range > tree->dirty_bytes);
407 tree->dirty_bytes -= range;
408 }
291d673e 409 clear_state_cb(tree, state, bits);
b0c68f8b 410 state->state &= ~bits;
d1310b2e
CM		 411 if (wake)
412 wake_up(&state->wq);
413 if (delete || state->state == 0) {
70dec807 414 if (state->tree) {
ae9d1285 415 clear_state_cb(tree, state, state->state);
d7fc640e
CM		 416 if (tree->last == state) {
417 tree->last = extent_state_next(state);
418 }
d1310b2e 419 rb_erase(&state->rb_node, &tree->state);
70dec807 420 state->tree = NULL;
d1310b2e
CM		 421 free_extent_state(state);
422 } else {
423 WARN_ON(1);
424 }
425 } else {
426 merge_state(tree, state);
427 }
428 return ret;
429}
430
431/*
432 * clear some bits on a range in the tree. This may require splitting
433 * or inserting elements in the tree, so the gfp mask is used to
434 * indicate which allocations or sleeping are allowed.
435 *
436 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
437 * the given range from the tree regardless of state (ie for truncate).
438 *
439 * the range [start, end] is inclusive.
440 *
441 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
442 * bits were already set, or zero if none of the bits were already set.
443 */
444int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
445 int bits, int wake, int delete, gfp_t mask)
446{
447 struct extent_state *state;
448 struct extent_state *prealloc = NULL;
449 struct rb_node *node;
450 unsigned long flags;
451 int err;
452 int set = 0;
453
454again:
455 if (!prealloc && (mask & __GFP_WAIT)) {
456 prealloc = alloc_extent_state(mask);
457 if (!prealloc)
458 return -ENOMEM;
459 }
460
70dec807 461 spin_lock_irqsave(&tree->lock, flags);
d1310b2e
CM		 462 /*
463 * this search will find the extents that end after
464 * our range starts
465 */
80ea96b1 466 node = tree_search(tree, start);
d1310b2e
CM		 467 if (!node)
468 goto out;
469 state = rb_entry(node, struct extent_state, rb_node);
470 if (state->start > end)
471 goto out;
472 WARN_ON(state->end < start);
473
474 /*
475 * | ---- desired range ---- |
476 * | state | or
477 * | ------------- state -------------- |
478 *
479 * We need to split the extent we found, and may flip
480 * bits on second half.
481 *
482 * If the extent we found extends past our range, we
483 * just split and search again. It'll get split again
484 * the next time though.
485 *
486 * If the extent we found is inside our range, we clear
487 * the desired bit on it.
488 */
489
490 if (state->start < start) {
70dec807
CM		 491 if (!prealloc)
492 prealloc = alloc_extent_state(GFP_ATOMIC);
d1310b2e
CM		 493 err = split_state(tree, state, prealloc, start);
494 BUG_ON(err == -EEXIST);
495 prealloc = NULL;
496 if (err)
497 goto out;
498 if (state->end <= end) {
499 start = state->end + 1;
500 set |= clear_state_bit(tree, state, bits,
501 wake, delete);
502 } else {
503 start = state->start;
504 }
505 goto search_again;
506 }
507 /*
508 * | ---- desired range ---- |
509 * | state |
510 * We need to split the extent, and clear the bit
511 * on the first half
512 */
513 if (state->start <= end && state->end > end) {
70dec807
CM		 514 if (!prealloc)
515 prealloc = alloc_extent_state(GFP_ATOMIC);
d1310b2e
CM		 516 err = split_state(tree, state, prealloc, end + 1);
517 BUG_ON(err == -EEXIST);
518
519 if (wake)
520 wake_up(&state->wq);
521 set |= clear_state_bit(tree, prealloc, bits,
522 wake, delete);
523 prealloc = NULL;
524 goto out;
525 }
526
527 start = state->end + 1;
528 set |= clear_state_bit(tree, state, bits, wake, delete);
529 goto search_again;
530
531out:
70dec807 532 spin_unlock_irqrestore(&tree->lock, flags);
d1310b2e
CM		 533 if (prealloc)
534 free_extent_state(prealloc);
535
536 return set;
537
538search_again:
539 if (start > end)
540 goto out;
70dec807 541 spin_unlock_irqrestore(&tree->lock, flags);
d1310b2e
CM		 542 if (mask & __GFP_WAIT)
543 cond_resched();
544 goto again;
545}
546EXPORT_SYMBOL(clear_extent_bit);
547
548static int wait_on_state(struct extent_io_tree *tree,
549 struct extent_state *state)
550{
551 DEFINE_WAIT(wait);
552 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
70dec807 553 spin_unlock_irq(&tree->lock);
d1310b2e 554 schedule();
70dec807 555 spin_lock_irq(&tree->lock);
d1310b2e
CM		 556 finish_wait(&state->wq, &wait);
557 return 0;
558}
559
560/*
561 * waits for one or more bits to clear on a range in the state tree.
562 * The range [start, end] is inclusive.
563 * The tree lock is taken by this function
564 */
565int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
566{
567 struct extent_state *state;
568 struct rb_node *node;
569
70dec807 570 spin_lock_irq(&tree->lock);
d1310b2e
CM		 571again:
572 while (1) {
573 /*
574 * this search will find all the extents that end after
575 * our range starts
576 */
80ea96b1 577 node = tree_search(tree, start);
d1310b2e
CM		 578 if (!node)
579 break;
580
581 state = rb_entry(node, struct extent_state, rb_node);
582
583 if (state->start > end)
584 goto out;
585
586 if (state->state & bits) {
587 start = state->start;
588 atomic_inc(&state->refs);
589 wait_on_state(tree, state);
590 free_extent_state(state);
591 goto again;
592 }
593 start = state->end + 1;
594
595 if (start > end)
596 break;
597
598 if (need_resched()) {
70dec807 599 spin_unlock_irq(&tree->lock);
d1310b2e 600 cond_resched();
70dec807 601 spin_lock_irq(&tree->lock);
d1310b2e
CM		 602 }
603 }
604out:
70dec807 605 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 606 return 0;
607}
608EXPORT_SYMBOL(wait_extent_bit);
609
610static void set_state_bits(struct extent_io_tree *tree,
611 struct extent_state *state,
612 int bits)
613{
614 if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
615 u64 range = state->end - state->start + 1;
616 tree->dirty_bytes += range;
617 }
291d673e 618 set_state_cb(tree, state, bits);
b0c68f8b 619 state->state |= bits;
d1310b2e
CM		 620}
621
622/*
623 * set some bits on a range in the tree. This may require allocations
624 * or sleeping, so the gfp mask is used to indicate what is allowed.
625 *
626 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
627 * range already has the desired bits set. The start of the existing
628 * range is returned in failed_start in this case.
629 *
630 * [start, end] is inclusive
631 * This takes the tree lock.
632 */
633int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits,
634 int exclusive, u64 *failed_start, gfp_t mask)
635{
636 struct extent_state *state;
637 struct extent_state *prealloc = NULL;
638 struct rb_node *node;
639 unsigned long flags;
640 int err = 0;
641 int set;
642 u64 last_start;
643 u64 last_end;
644again:
645 if (!prealloc && (mask & __GFP_WAIT)) {
646 prealloc = alloc_extent_state(mask);
647 if (!prealloc)
648 return -ENOMEM;
649 }
650
70dec807 651 spin_lock_irqsave(&tree->lock, flags);
d1310b2e
CM		 652 /*
653 * this search will find all the extents that end after
654 * our range starts.
655 */
80ea96b1 656 node = tree_search(tree, start);
d1310b2e
CM		 657 if (!node) {
658 err = insert_state(tree, prealloc, start, end, bits);
659 prealloc = NULL;
660 BUG_ON(err == -EEXIST);
661 goto out;
662 }
663
664 state = rb_entry(node, struct extent_state, rb_node);
665 last_start = state->start;
666 last_end = state->end;
667
668 /*
669 * | ---- desired range ---- |
670 * | state |
671 *
672 * Just lock what we found and keep going
673 */
674 if (state->start == start && state->end <= end) {
675 set = state->state & bits;
676 if (set && exclusive) {
677 *failed_start = state->start;
678 err = -EEXIST;
679 goto out;
680 }
681 set_state_bits(tree, state, bits);
682 start = state->end + 1;
683 merge_state(tree, state);
684 goto search_again;
685 }
686
687 /*
688 * | ---- desired range ---- |
689 * | state |
690 * or
691 * | ------------- state -------------- |
692 *
693 * We need to split the extent we found, and may flip bits on
694 * second half.
695 *
696 * If the extent we found extends past our
697 * range, we just split and search again. It'll get split
698 * again the next time though.
699 *
700 * If the extent we found is inside our range, we set the
701 * desired bit on it.
702 */
703 if (state->start < start) {
704 set = state->state & bits;
705 if (exclusive && set) {
706 *failed_start = start;
707 err = -EEXIST;
708 goto out;
709 }
710 err = split_state(tree, state, prealloc, start);
711 BUG_ON(err == -EEXIST);
712 prealloc = NULL;
713 if (err)
714 goto out;
715 if (state->end <= end) {
716 set_state_bits(tree, state, bits);
717 start = state->end + 1;
718 merge_state(tree, state);
719 } else {
720 start = state->start;
721 }
722 goto search_again;
723 }
724 /*
725 * | ---- desired range ---- |
726 * | state | or | state |
727 *
728 * There's a hole, we need to insert something in it and
729 * ignore the extent we found.
730 */
731 if (state->start > start) {
732 u64 this_end;
733 if (end < last_start)
734 this_end = end;
735 else
736 this_end = last_start -1;
737 err = insert_state(tree, prealloc, start, this_end,
738 bits);
739 prealloc = NULL;
740 BUG_ON(err == -EEXIST);
741 if (err)
742 goto out;
743 start = this_end + 1;
744 goto search_again;
745 }
746 /*
747 * | ---- desired range ---- |
748 * | state |
749 * We need to split the extent, and set the bit
750 * on the first half
751 */
752 if (state->start <= end && state->end > end) {
753 set = state->state & bits;
754 if (exclusive && set) {
755 *failed_start = start;
756 err = -EEXIST;
757 goto out;
758 }
759 err = split_state(tree, state, prealloc, end + 1);
760 BUG_ON(err == -EEXIST);
761
762 set_state_bits(tree, prealloc, bits);
763 merge_state(tree, prealloc);
764 prealloc = NULL;
765 goto out;
766 }
767
768 goto search_again;
769
770out:
70dec807 771 spin_unlock_irqrestore(&tree->lock, flags);
d1310b2e
CM		 772 if (prealloc)
773 free_extent_state(prealloc);
774
775 return err;
776
777search_again:
778 if (start > end)
779 goto out;
70dec807 780 spin_unlock_irqrestore(&tree->lock, flags);
d1310b2e
CM		 781 if (mask & __GFP_WAIT)
782 cond_resched();
783 goto again;
784}
785EXPORT_SYMBOL(set_extent_bit);
786
787/* wrappers around set/clear extent bit */
788int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
789 gfp_t mask)
790{
791 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
792 mask);
793}
794EXPORT_SYMBOL(set_extent_dirty);
795
e6dcd2dc
CM		 796int set_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
797 gfp_t mask)
798{
799 return set_extent_bit(tree, start, end, EXTENT_ORDERED, 0, NULL, mask);
800}
801EXPORT_SYMBOL(set_extent_ordered);
802
d1310b2e
CM		 803int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
804 int bits, gfp_t mask)
805{
806 return set_extent_bit(tree, start, end, bits, 0, NULL,
807 mask);
808}
809EXPORT_SYMBOL(set_extent_bits);
810
811int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
812 int bits, gfp_t mask)
813{
814 return clear_extent_bit(tree, start, end, bits, 0, 0, mask);
815}
816EXPORT_SYMBOL(clear_extent_bits);
817
818int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
819 gfp_t mask)
820{
821 return set_extent_bit(tree, start, end,
e6dcd2dc
CM		 822 EXTENT_DELALLOC | EXTENT_DIRTY,
823 0, NULL, mask);
d1310b2e
CM		 824}
825EXPORT_SYMBOL(set_extent_delalloc);
826
827int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
828 gfp_t mask)
829{
830 return clear_extent_bit(tree, start, end,
831 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask);
832}
833EXPORT_SYMBOL(clear_extent_dirty);
834
e6dcd2dc
CM		 835int clear_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
836 gfp_t mask)
837{
838 return clear_extent_bit(tree, start, end, EXTENT_ORDERED, 1, 0, mask);
839}
840EXPORT_SYMBOL(clear_extent_ordered);
841
d1310b2e
CM		 842int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
843 gfp_t mask)
844{
845 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
846 mask);
847}
848EXPORT_SYMBOL(set_extent_new);
849
850int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
851 gfp_t mask)
852{
853 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask);
854}
855EXPORT_SYMBOL(clear_extent_new);
856
857int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
858 gfp_t mask)
859{
860 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
861 mask);
862}
863EXPORT_SYMBOL(set_extent_uptodate);
864
865int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
866 gfp_t mask)
867{
868 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask);
869}
870EXPORT_SYMBOL(clear_extent_uptodate);
871
872int set_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
873 gfp_t mask)
874{
875 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK,
876 0, NULL, mask);
877}
878EXPORT_SYMBOL(set_extent_writeback);
879
880int clear_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
881 gfp_t mask)
882{
883 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask);
884}
885EXPORT_SYMBOL(clear_extent_writeback);
886
887int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
888{
889 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
890}
891EXPORT_SYMBOL(wait_on_extent_writeback);
892
d1310b2e
CM		 893int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
894{
895 int err;
896 u64 failed_start;
897 while (1) {
898 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
899 &failed_start, mask);
900 if (err == -EEXIST && (mask & __GFP_WAIT)) {
901 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
902 start = failed_start;
903 } else {
904 break;
905 }
906 WARN_ON(start > end);
907 }
908 return err;
909}
910EXPORT_SYMBOL(lock_extent);
911
912int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
913 gfp_t mask)
914{
915 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask);
916}
917EXPORT_SYMBOL(unlock_extent);
918
919/*
920 * helper function to set pages and extents in the tree dirty
921 */
922int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
923{
924 unsigned long index = start >> PAGE_CACHE_SHIFT;
925 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
926 struct page *page;
927
928 while (index <= end_index) {
929 page = find_get_page(tree->mapping, index);
930 BUG_ON(!page);
931 __set_page_dirty_nobuffers(page);
932 page_cache_release(page);
933 index++;
934 }
935 set_extent_dirty(tree, start, end, GFP_NOFS);
936 return 0;
937}
938EXPORT_SYMBOL(set_range_dirty);
939
940/*
941 * helper function to set both pages and extents in the tree writeback
942 */
943int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
944{
945 unsigned long index = start >> PAGE_CACHE_SHIFT;
946 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
947 struct page *page;
948
949 while (index <= end_index) {
950 page = find_get_page(tree->mapping, index);
951 BUG_ON(!page);
952 set_page_writeback(page);
953 page_cache_release(page);
954 index++;
955 }
956 set_extent_writeback(tree, start, end, GFP_NOFS);
957 return 0;
958}
959EXPORT_SYMBOL(set_range_writeback);
960
961int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
962 u64 *start_ret, u64 *end_ret, int bits)
963{
964 struct rb_node *node;
965 struct extent_state *state;
966 int ret = 1;
967
70dec807 968 spin_lock_irq(&tree->lock);
d1310b2e
CM		 969 /*
970 * this search will find all the extents that end after
971 * our range starts.
972 */
80ea96b1 973 node = tree_search(tree, start);
2b114d1d 974 if (!node) {
d1310b2e
CM		 975 goto out;
976 }
977
978 while(1) {
979 state = rb_entry(node, struct extent_state, rb_node);
980 if (state->end >= start && (state->state & bits)) {
981 *start_ret = state->start;
982 *end_ret = state->end;
983 ret = 0;
984 break;
985 }
986 node = rb_next(node);
987 if (!node)
988 break;
989 }
990out:
70dec807 991 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 992 return ret;
993}
994EXPORT_SYMBOL(find_first_extent_bit);
995
d7fc640e
CM		 996struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
997 u64 start, int bits)
998{
999 struct rb_node *node;
1000 struct extent_state *state;
1001
1002 /*
1003 * this search will find all the extents that end after
1004 * our range starts.
1005 */
1006 node = tree_search(tree, start);
2b114d1d 1007 if (!node) {
d7fc640e
CM		 1008 goto out;
1009 }
1010
1011 while(1) {
1012 state = rb_entry(node, struct extent_state, rb_node);
1013 if (state->end >= start && (state->state & bits)) {
1014 return state;
1015 }
1016 node = rb_next(node);
1017 if (!node)
1018 break;
1019 }
1020out:
1021 return NULL;
1022}
1023EXPORT_SYMBOL(find_first_extent_bit_state);
1024
d1310b2e
CM		 1025u64 find_lock_delalloc_range(struct extent_io_tree *tree,
1026 u64 *start, u64 *end, u64 max_bytes)
1027{
1028 struct rb_node *node;
1029 struct extent_state *state;
1030 u64 cur_start = *start;
1031 u64 found = 0;
1032 u64 total_bytes = 0;
1033
70dec807 1034 spin_lock_irq(&tree->lock);
d1310b2e
CM		 1035 /*
1036 * this search will find all the extents that end after
1037 * our range starts.
1038 */
1039search_again:
80ea96b1 1040 node = tree_search(tree, cur_start);
2b114d1d 1041 if (!node) {
3b951516
CM		 1042 if (!found)
1043 *end = (u64)-1;
d1310b2e
CM		 1044 goto out;
1045 }
1046
1047 while(1) {
1048 state = rb_entry(node, struct extent_state, rb_node);
1049 if (found && state->start != cur_start) {
1050 goto out;
1051 }
1052 if (!(state->state & EXTENT_DELALLOC)) {
1053 if (!found)
1054 *end = state->end;
1055 goto out;
1056 }
1057 if (!found) {
1058 struct extent_state *prev_state;
1059 struct rb_node *prev_node = node;
1060 while(1) {
1061 prev_node = rb_prev(prev_node);
1062 if (!prev_node)
1063 break;
1064 prev_state = rb_entry(prev_node,
1065 struct extent_state,
1066 rb_node);
1067 if (!(prev_state->state & EXTENT_DELALLOC))
1068 break;
1069 state = prev_state;
1070 node = prev_node;
1071 }
1072 }
1073 if (state->state & EXTENT_LOCKED) {
1074 DEFINE_WAIT(wait);
1075 atomic_inc(&state->refs);
1076 prepare_to_wait(&state->wq, &wait,
1077 TASK_UNINTERRUPTIBLE);
70dec807 1078 spin_unlock_irq(&tree->lock);
d1310b2e 1079 schedule();
70dec807 1080 spin_lock_irq(&tree->lock);
d1310b2e
CM		 1081 finish_wait(&state->wq, &wait);
1082 free_extent_state(state);
1083 goto search_again;
1084 }
291d673e 1085 set_state_cb(tree, state, EXTENT_LOCKED);
b0c68f8b 1086 state->state |= EXTENT_LOCKED;
d1310b2e
CM		 1087 if (!found)
1088 *start = state->start;
1089 found++;
1090 *end = state->end;
1091 cur_start = state->end + 1;
1092 node = rb_next(node);
1093 if (!node)
1094 break;
1095 total_bytes += state->end - state->start + 1;
1096 if (total_bytes >= max_bytes)
1097 break;
1098 }
1099out:
70dec807 1100 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 1101 return found;
1102}
1103
1104u64 count_range_bits(struct extent_io_tree *tree,
1105 u64 *start, u64 search_end, u64 max_bytes,
1106 unsigned long bits)
1107{
1108 struct rb_node *node;
1109 struct extent_state *state;
1110 u64 cur_start = *start;
1111 u64 total_bytes = 0;
1112 int found = 0;
1113
1114 if (search_end <= cur_start) {
1115 printk("search_end %Lu start %Lu\n", search_end, cur_start);
1116 WARN_ON(1);
1117 return 0;
1118 }
1119
70dec807 1120 spin_lock_irq(&tree->lock);
d1310b2e
CM		 1121 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1122 total_bytes = tree->dirty_bytes;
1123 goto out;
1124 }
1125 /*
1126 * this search will find all the extents that end after
1127 * our range starts.
1128 */
80ea96b1 1129 node = tree_search(tree, cur_start);
2b114d1d 1130 if (!node) {
d1310b2e
CM		 1131 goto out;
1132 }
1133
1134 while(1) {
1135 state = rb_entry(node, struct extent_state, rb_node);
1136 if (state->start > search_end)
1137 break;
1138 if (state->end >= cur_start && (state->state & bits)) {
1139 total_bytes += min(search_end, state->end) + 1 -
1140 max(cur_start, state->start);
1141 if (total_bytes >= max_bytes)
1142 break;
1143 if (!found) {
1144 *start = state->start;
1145 found = 1;
1146 }
1147 }
1148 node = rb_next(node);
1149 if (!node)
1150 break;
1151 }
1152out:
70dec807 1153 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 1154 return total_bytes;
1155}
1156/*
1157 * helper function to lock both pages and extents in the tree.
1158 * pages must be locked first.
1159 */
1160int lock_range(struct extent_io_tree *tree, u64 start, u64 end)
1161{
1162 unsigned long index = start >> PAGE_CACHE_SHIFT;
1163 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1164 struct page *page;
1165 int err;
1166
1167 while (index <= end_index) {
1168 page = grab_cache_page(tree->mapping, index);
1169 if (!page) {
1170 err = -ENOMEM;
1171 goto failed;
1172 }
1173 if (IS_ERR(page)) {
1174 err = PTR_ERR(page);
1175 goto failed;
1176 }
1177 index++;
1178 }
1179 lock_extent(tree, start, end, GFP_NOFS);
1180 return 0;
1181
1182failed:
1183 /*
1184 * we failed above in getting the page at 'index', so we undo here
1185 * up to but not including the page at 'index'
1186 */
1187 end_index = index;
1188 index = start >> PAGE_CACHE_SHIFT;
1189 while (index < end_index) {
1190 page = find_get_page(tree->mapping, index);
1191 unlock_page(page);
1192 page_cache_release(page);
1193 index++;
1194 }
1195 return err;
1196}
1197EXPORT_SYMBOL(lock_range);
1198
1199/*
1200 * helper function to unlock both pages and extents in the tree.
1201 */
1202int unlock_range(struct extent_io_tree *tree, u64 start, u64 end)
1203{
1204 unsigned long index = start >> PAGE_CACHE_SHIFT;
1205 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1206 struct page *page;
1207
1208 while (index <= end_index) {
1209 page = find_get_page(tree->mapping, index);
1210 unlock_page(page);
1211 page_cache_release(page);
1212 index++;
1213 }
1214 unlock_extent(tree, start, end, GFP_NOFS);
1215 return 0;
1216}
1217EXPORT_SYMBOL(unlock_range);
1218
1219int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1220{
1221 struct rb_node *node;
1222 struct extent_state *state;
1223 int ret = 0;
1224
70dec807 1225 spin_lock_irq(&tree->lock);
d1310b2e
CM		 1226 /*
1227 * this search will find all the extents that end after
1228 * our range starts.
1229 */
80ea96b1 1230 node = tree_search(tree, start);
2b114d1d 1231 if (!node) {
d1310b2e
CM		 1232 ret = -ENOENT;
1233 goto out;
1234 }
1235 state = rb_entry(node, struct extent_state, rb_node);
1236 if (state->start != start) {
1237 ret = -ENOENT;
1238 goto out;
1239 }
1240 state->private = private;
1241out:
70dec807 1242 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 1243 return ret;
1244}
1245
1246int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1247{
1248 struct rb_node *node;
1249 struct extent_state *state;
1250 int ret = 0;
1251
70dec807 1252 spin_lock_irq(&tree->lock);
d1310b2e
CM		 1253 /*
1254 * this search will find all the extents that end after
1255 * our range starts.
1256 */
80ea96b1 1257 node = tree_search(tree, start);
2b114d1d 1258 if (!node) {
d1310b2e
CM		 1259 ret = -ENOENT;
1260 goto out;
1261 }
1262 state = rb_entry(node, struct extent_state, rb_node);
1263 if (state->start != start) {
1264 ret = -ENOENT;
1265 goto out;
1266 }
1267 *private = state->private;
1268out:
70dec807 1269 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 1270 return ret;
1271}
1272
1273/*
1274 * searches a range in the state tree for a given mask.
70dec807 1275 * If 'filled' == 1, this returns 1 only if every extent in the tree
d1310b2e
CM		 1276 * has the bits set. Otherwise, 1 is returned if any bit in the
1277 * range is found set.
1278 */
1279int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1280 int bits, int filled)
1281{
1282 struct extent_state *state = NULL;
1283 struct rb_node *node;
1284 int bitset = 0;
1285 unsigned long flags;
1286
70dec807 1287 spin_lock_irqsave(&tree->lock, flags);
80ea96b1 1288 node = tree_search(tree, start);
d1310b2e
CM		 1289 while (node && start <= end) {
1290 state = rb_entry(node, struct extent_state, rb_node);
1291
1292 if (filled && state->start > start) {
1293 bitset = 0;
1294 break;
1295 }
1296
1297 if (state->start > end)
1298 break;
1299
1300 if (state->state & bits) {
1301 bitset = 1;
1302 if (!filled)
1303 break;
1304 } else if (filled) {
1305 bitset = 0;
1306 break;
1307 }
1308 start = state->end + 1;
1309 if (start > end)
1310 break;
1311 node = rb_next(node);
1312 if (!node) {
1313 if (filled)
1314 bitset = 0;
1315 break;
1316 }
1317 }
70dec807 1318 spin_unlock_irqrestore(&tree->lock, flags);
d1310b2e
CM		 1319 return bitset;
1320}
1321EXPORT_SYMBOL(test_range_bit);
1322
1323/*
1324 * helper function to set a given page up to date if all the
1325 * extents in the tree for that page are up to date
1326 */
1327static int check_page_uptodate(struct extent_io_tree *tree,
1328 struct page *page)
1329{
1330 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1331 u64 end = start + PAGE_CACHE_SIZE - 1;
1332 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
1333 SetPageUptodate(page);
1334 return 0;
1335}
1336
1337/*
1338 * helper function to unlock a page if all the extents in the tree
1339 * for that page are unlocked
1340 */
1341static int check_page_locked(struct extent_io_tree *tree,
1342 struct page *page)
1343{
1344 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1345 u64 end = start + PAGE_CACHE_SIZE - 1;
1346 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
1347 unlock_page(page);
1348 return 0;
1349}
1350
1351/*
1352 * helper function to end page writeback if all the extents
1353 * in the tree for that page are done with writeback
1354 */
1355static int check_page_writeback(struct extent_io_tree *tree,
1356 struct page *page)
1357{
1358 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1359 u64 end = start + PAGE_CACHE_SIZE - 1;
1360 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0))
1361 end_page_writeback(page);
1362 return 0;
1363}
1364
1365/* lots and lots of room for performance fixes in the end_bio funcs */
1366
1367/*
1368 * after a writepage IO is done, we need to:
1369 * clear the uptodate bits on error
1370 * clear the writeback bits in the extent tree for this IO
1371 * end_page_writeback if the page has no more pending IO
1372 *
1373 * Scheduling is not allowed, so the extent state tree is expected
1374 * to have one and only one object corresponding to this IO.
1375 */
1376#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1377static void end_bio_extent_writepage(struct bio *bio, int err)
1378#else
1379static int end_bio_extent_writepage(struct bio *bio,
1380 unsigned int bytes_done, int err)
1381#endif
1382{
1259ab75 1383 int uptodate = err == 0;
d1310b2e 1384 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
70dec807
CM		 1385 struct extent_state *state = bio->bi_private;
1386 struct extent_io_tree *tree = state->tree;
1387 struct rb_node *node;
d1310b2e
CM		 1388 u64 start;
1389 u64 end;
70dec807 1390 u64 cur;
d1310b2e 1391 int whole_page;
1259ab75 1392 int ret;
70dec807 1393 unsigned long flags;
d1310b2e
CM		 1394
1395#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1396 if (bio->bi_size)
1397 return 1;
1398#endif
d1310b2e
CM		 1399 do {
1400 struct page *page = bvec->bv_page;
1401 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1402 bvec->bv_offset;
1403 end = start + bvec->bv_len - 1;
1404
1405 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1406 whole_page = 1;
1407 else
1408 whole_page = 0;
1409
1410 if (--bvec >= bio->bi_io_vec)
1411 prefetchw(&bvec->bv_page->flags);
1259ab75
CM		 1412 if (tree->ops && tree->ops->writepage_end_io_hook) {
1413 ret = tree->ops->writepage_end_io_hook(page, start,
e6dcd2dc 1414 end, state, uptodate);
1259ab75
CM		 1415 if (ret)
1416 uptodate = 0;
1417 }
1418
1419 if (!uptodate && tree->ops &&
1420 tree->ops->writepage_io_failed_hook) {
1421 ret = tree->ops->writepage_io_failed_hook(bio, page,
1422 start, end, state);
1423 if (ret == 0) {
1424 state = NULL;
1425 uptodate = (err == 0);
1426 continue;
1427 }
1428 }
1429
d1310b2e
CM		 1430 if (!uptodate) {
1431 clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
1432 ClearPageUptodate(page);
1433 SetPageError(page);
1434 }
70dec807 1435
70dec807
CM		 1436 /*
1437 * bios can get merged in funny ways, and so we need to
1438 * be careful with the state variable. We know the
1439 * state won't be merged with others because it has
1440 * WRITEBACK set, but we can't be sure each biovec is
1441 * sequential in the file. So, if our cached state
1442 * doesn't match the expected end, search the tree
1443 * for the correct one.
1444 */
1445
1446 spin_lock_irqsave(&tree->lock, flags);
1447 if (!state || state->end != end) {
1448 state = NULL;
80ea96b1 1449 node = __etree_search(tree, start, NULL, NULL);
70dec807
CM		 1450 if (node) {
1451 state = rb_entry(node, struct extent_state,
1452 rb_node);
1453 if (state->end != end ||
1454 !(state->state & EXTENT_WRITEBACK))
1455 state = NULL;
1456 }
1457 if (!state) {
1458 spin_unlock_irqrestore(&tree->lock, flags);
1459 clear_extent_writeback(tree, start,
1460 end, GFP_ATOMIC);
1461 goto next_io;
1462 }
1463 }
1464 cur = end;
1465 while(1) {
1466 struct extent_state *clear = state;
1467 cur = state->start;
1468 node = rb_prev(&state->rb_node);
1469 if (node) {
1470 state = rb_entry(node,
1471 struct extent_state,
1472 rb_node);
1473 } else {
1474 state = NULL;
1475 }
1476
1477 clear_state_bit(tree, clear, EXTENT_WRITEBACK,
1478 1, 0);
1479 if (cur == start)
1480 break;
1481 if (cur < start) {
1482 WARN_ON(1);
1483 break;
1484 }
1485 if (!node)
1486 break;
1487 }
1488 /* before releasing the lock, make sure the next state
1489 * variable has the expected bits set and corresponds
1490 * to the correct offsets in the file
1491 */
1492 if (state && (state->end + 1 != start ||
c2e639f0 1493 !(state->state & EXTENT_WRITEBACK))) {
70dec807
CM		 1494 state = NULL;
1495 }
1496 spin_unlock_irqrestore(&tree->lock, flags);
1497next_io:
d1310b2e
CM		 1498
1499 if (whole_page)
1500 end_page_writeback(page);
1501 else
1502 check_page_writeback(tree, page);
d1310b2e 1503 } while (bvec >= bio->bi_io_vec);
d1310b2e
CM		 1504 bio_put(bio);
1505#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1506 return 0;
1507#endif
1508}
1509
1510/*
1511 * after a readpage IO is done, we need to:
1512 * clear the uptodate bits on error
1513 * set the uptodate bits if things worked
1514 * set the page up to date if all extents in the tree are uptodate
1515 * clear the lock bit in the extent tree
1516 * unlock the page if there are no other extents locked for it
1517 *
1518 * Scheduling is not allowed, so the extent state tree is expected
1519 * to have one and only one object corresponding to this IO.
1520 */
1521#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1522static void end_bio_extent_readpage(struct bio *bio, int err)
1523#else
1524static int end_bio_extent_readpage(struct bio *bio,
1525 unsigned int bytes_done, int err)
1526#endif
1527{
1528 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1529 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
70dec807
CM		 1530 struct extent_state *state = bio->bi_private;
1531 struct extent_io_tree *tree = state->tree;
1532 struct rb_node *node;
d1310b2e
CM		 1533 u64 start;
1534 u64 end;
70dec807
CM		 1535 u64 cur;
1536 unsigned long flags;
d1310b2e
CM		 1537 int whole_page;
1538 int ret;
1539
1540#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1541 if (bio->bi_size)
1542 return 1;
1543#endif
1544
1545 do {
1546 struct page *page = bvec->bv_page;
1547 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1548 bvec->bv_offset;
1549 end = start + bvec->bv_len - 1;
1550
1551 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1552 whole_page = 1;
1553 else
1554 whole_page = 0;
1555
1556 if (--bvec >= bio->bi_io_vec)
1557 prefetchw(&bvec->bv_page->flags);
1558
1559 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
70dec807
CM		 1560 ret = tree->ops->readpage_end_io_hook(page, start, end,
1561 state);
d1310b2e
CM		 1562 if (ret)
1563 uptodate = 0;
1564 }
7e38326f
CM		 1565 if (!uptodate && tree->ops &&
1566 tree->ops->readpage_io_failed_hook) {
1567 ret = tree->ops->readpage_io_failed_hook(bio, page,
1568 start, end, state);
1569 if (ret == 0) {
1570 state = NULL;
3b951516
CM		 1571 uptodate =
1572 test_bit(BIO_UPTODATE, &bio->bi_flags);
7e38326f
CM		 1573 continue;
1574 }
1575 }
d1310b2e 1576
70dec807
CM		 1577 spin_lock_irqsave(&tree->lock, flags);
1578 if (!state || state->end != end) {
1579 state = NULL;
80ea96b1 1580 node = __etree_search(tree, start, NULL, NULL);
70dec807
CM		 1581 if (node) {
1582 state = rb_entry(node, struct extent_state,
1583 rb_node);
1584 if (state->end != end ||
1585 !(state->state & EXTENT_LOCKED))
1586 state = NULL;
1587 }
3b951516 1588 if (!state) {
70dec807 1589 spin_unlock_irqrestore(&tree->lock, flags);
3b951516
CM		 1590 if (uptodate)
1591 set_extent_uptodate(tree, start, end,
1592 GFP_ATOMIC);
70dec807
CM		 1593 unlock_extent(tree, start, end, GFP_ATOMIC);
1594 goto next_io;
1595 }
1596 }
d1310b2e 1597
70dec807
CM		 1598 cur = end;
1599 while(1) {
1600 struct extent_state *clear = state;
1601 cur = state->start;
1602 node = rb_prev(&state->rb_node);
1603 if (node) {
1604 state = rb_entry(node,
1605 struct extent_state,
1606 rb_node);
1607 } else {
1608 state = NULL;
1609 }
f188591e
CM		 1610 if (uptodate) {
1611 set_state_cb(tree, clear, EXTENT_UPTODATE);
1612 clear->state |= EXTENT_UPTODATE;
1613 }
70dec807
CM		 1614 clear_state_bit(tree, clear, EXTENT_LOCKED,
1615 1, 0);
1616 if (cur == start)
1617 break;
1618 if (cur < start) {
1619 WARN_ON(1);
1620 break;
1621 }
1622 if (!node)
1623 break;
1624 }
1625 /* before releasing the lock, make sure the next state
1626 * variable has the expected bits set and corresponds
1627 * to the correct offsets in the file
1628 */
1629 if (state && (state->end + 1 != start ||
c2e639f0 1630 !(state->state & EXTENT_LOCKED))) {
70dec807
CM		 1631 state = NULL;
1632 }
1633 spin_unlock_irqrestore(&tree->lock, flags);
1634next_io:
1635 if (whole_page) {
1636 if (uptodate) {
1637 SetPageUptodate(page);
1638 } else {
1639 ClearPageUptodate(page);
1640 SetPageError(page);
1641 }
d1310b2e 1642 unlock_page(page);
70dec807
CM		 1643 } else {
1644 if (uptodate) {
1645 check_page_uptodate(tree, page);
1646 } else {
1647 ClearPageUptodate(page);
1648 SetPageError(page);
1649 }
d1310b2e 1650 check_page_locked(tree, page);
70dec807 1651 }
d1310b2e
CM		 1652 } while (bvec >= bio->bi_io_vec);
1653
1654 bio_put(bio);
1655#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1656 return 0;
1657#endif
1658}
1659
1660/*
1661 * IO done from prepare_write is pretty simple, we just unlock
1662 * the structs in the extent tree when done, and set the uptodate bits
1663 * as appropriate.
1664 */
1665#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1666static void end_bio_extent_preparewrite(struct bio *bio, int err)
1667#else
1668static int end_bio_extent_preparewrite(struct bio *bio,
1669 unsigned int bytes_done, int err)
1670#endif
1671{
1672 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1673 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
70dec807
CM		 1674 struct extent_state *state = bio->bi_private;
1675 struct extent_io_tree *tree = state->tree;
d1310b2e
CM		 1676 u64 start;
1677 u64 end;
1678
1679#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1680 if (bio->bi_size)
1681 return 1;
1682#endif
1683
1684 do {
1685 struct page *page = bvec->bv_page;
1686 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1687 bvec->bv_offset;
1688 end = start + bvec->bv_len - 1;
1689
1690 if (--bvec >= bio->bi_io_vec)
1691 prefetchw(&bvec->bv_page->flags);
1692
1693 if (uptodate) {
1694 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1695 } else {
1696 ClearPageUptodate(page);
1697 SetPageError(page);
1698 }
1699
1700 unlock_extent(tree, start, end, GFP_ATOMIC);
1701
1702 } while (bvec >= bio->bi_io_vec);
1703
1704 bio_put(bio);
1705#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1706 return 0;
1707#endif
1708}
1709
1710static struct bio *
1711extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
1712 gfp_t gfp_flags)
1713{
1714 struct bio *bio;
1715
1716 bio = bio_alloc(gfp_flags, nr_vecs);
1717
1718 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
1719 while (!bio && (nr_vecs /= 2))
1720 bio = bio_alloc(gfp_flags, nr_vecs);
1721 }
1722
1723 if (bio) {
e1c4b745 1724 bio->bi_size = 0;
d1310b2e
CM		 1725 bio->bi_bdev = bdev;
1726 bio->bi_sector = first_sector;
1727 }
1728 return bio;
1729}
1730
f188591e 1731static int submit_one_bio(int rw, struct bio *bio, int mirror_num)
d1310b2e 1732{
d1310b2e 1733 int ret = 0;
70dec807
CM		 1734 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1735 struct page *page = bvec->bv_page;
1736 struct extent_io_tree *tree = bio->bi_private;
1737 struct rb_node *node;
1738 struct extent_state *state;
1739 u64 start;
1740 u64 end;
1741
1742 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1743 end = start + bvec->bv_len - 1;
1744
1745 spin_lock_irq(&tree->lock);
80ea96b1 1746 node = __etree_search(tree, start, NULL, NULL);
70dec807
CM		 1747 BUG_ON(!node);
1748 state = rb_entry(node, struct extent_state, rb_node);
1749 while(state->end < end) {
1750 node = rb_next(node);
1751 state = rb_entry(node, struct extent_state, rb_node);
1752 }
1753 BUG_ON(state->end != end);
1754 spin_unlock_irq(&tree->lock);
1755
1756 bio->bi_private = state;
d1310b2e
CM		 1757
1758 bio_get(bio);
1759
065631f6 1760 if (tree->ops && tree->ops->submit_bio_hook)
f188591e
CM		 1761 tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
1762 mirror_num);
0b86a832
CM		 1763 else
1764 submit_bio(rw, bio);
d1310b2e
CM		 1765 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1766 ret = -EOPNOTSUPP;
1767 bio_put(bio);
1768 return ret;
1769}
1770
1771static int submit_extent_page(int rw, struct extent_io_tree *tree,
1772 struct page *page, sector_t sector,
1773 size_t size, unsigned long offset,
1774 struct block_device *bdev,
1775 struct bio **bio_ret,
1776 unsigned long max_pages,
f188591e
CM		 1777 bio_end_io_t end_io_func,
1778 int mirror_num)
d1310b2e
CM		 1779{
1780 int ret = 0;
1781 struct bio *bio;
1782 int nr;
1783
1784 if (bio_ret && *bio_ret) {
1785 bio = *bio_ret;
1786 if (bio->bi_sector + (bio->bi_size >> 9) != sector ||
239b14b3
CM		 1787 (tree->ops && tree->ops->merge_bio_hook &&
1788 tree->ops->merge_bio_hook(page, offset, size, bio)) ||
d1310b2e 1789 bio_add_page(bio, page, size, offset) < size) {
f188591e 1790 ret = submit_one_bio(rw, bio, mirror_num);
d1310b2e
CM		 1791 bio = NULL;
1792 } else {
1793 return 0;
1794 }
1795 }
961d0232 1796 nr = bio_get_nr_vecs(bdev);
d1310b2e
CM		 1797 bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
1798 if (!bio) {
1799 printk("failed to allocate bio nr %d\n", nr);
1800 }
70dec807
CM		 1801
1802
d1310b2e
CM		 1803 bio_add_page(bio, page, size, offset);
1804 bio->bi_end_io = end_io_func;
1805 bio->bi_private = tree;
70dec807 1806
d1310b2e
CM		 1807 if (bio_ret) {
1808 *bio_ret = bio;
1809 } else {
f188591e 1810 ret = submit_one_bio(rw, bio, mirror_num);
d1310b2e
CM		 1811 }
1812
1813 return ret;
1814}
1815
1816void set_page_extent_mapped(struct page *page)
1817{
1818 if (!PagePrivate(page)) {
1819 SetPagePrivate(page);
1820 WARN_ON(!page->mapping->a_ops->invalidatepage);
1821 set_page_private(page, EXTENT_PAGE_PRIVATE);
1822 page_cache_get(page);
1823 }
1824}
1825
1826void set_page_extent_head(struct page *page, unsigned long len)
1827{
1828 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
1829}
1830
1831/*
1832 * basic readpage implementation. Locked extent state structs are inserted
1833 * into the tree that are removed when the IO is done (by the end_io
1834 * handlers)
1835 */
1836static int __extent_read_full_page(struct extent_io_tree *tree,
1837 struct page *page,
1838 get_extent_t *get_extent,
f188591e 1839 struct bio **bio, int mirror_num)
d1310b2e
CM		 1840{
1841 struct inode *inode = page->mapping->host;
1842 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1843 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1844 u64 end;
1845 u64 cur = start;
1846 u64 extent_offset;
1847 u64 last_byte = i_size_read(inode);
1848 u64 block_start;
1849 u64 cur_end;
1850 sector_t sector;
1851 struct extent_map *em;
1852 struct block_device *bdev;
1853 int ret;
1854 int nr = 0;
1855 size_t page_offset = 0;
1856 size_t iosize;
1857 size_t blocksize = inode->i_sb->s_blocksize;
1858
1859 set_page_extent_mapped(page);
1860
1861 end = page_end;
1862 lock_extent(tree, start, end, GFP_NOFS);
1863
1864 while (cur <= end) {
1865 if (cur >= last_byte) {
1866 char *userpage;
1867 iosize = PAGE_CACHE_SIZE - page_offset;
1868 userpage = kmap_atomic(page, KM_USER0);
1869 memset(userpage + page_offset, 0, iosize);
1870 flush_dcache_page(page);
1871 kunmap_atomic(userpage, KM_USER0);
1872 set_extent_uptodate(tree, cur, cur + iosize - 1,
1873 GFP_NOFS);
1874 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1875 break;
1876 }
1877 em = get_extent(inode, page, page_offset, cur,
1878 end - cur + 1, 0);
1879 if (IS_ERR(em) || !em) {
1880 SetPageError(page);
1881 unlock_extent(tree, cur, end, GFP_NOFS);
1882 break;
1883 }
d1310b2e 1884 extent_offset = cur - em->start;
e6dcd2dc
CM		 1885 if (extent_map_end(em) <= cur) {
1886printk("bad mapping em [%Lu %Lu] cur %Lu\n", em->start, extent_map_end(em), cur);
1887 }
d1310b2e 1888 BUG_ON(extent_map_end(em) <= cur);
e6dcd2dc
CM		 1889 if (end < cur) {
1890printk("2bad mapping end %Lu cur %Lu\n", end, cur);
1891 }
d1310b2e
CM		 1892 BUG_ON(end < cur);
1893
1894 iosize = min(extent_map_end(em) - cur, end - cur + 1);
1895 cur_end = min(extent_map_end(em) - 1, end);
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 /* we've found a hole, just zero and go on */
1904 if (block_start == EXTENT_MAP_HOLE) {
1905 char *userpage;
1906 userpage = kmap_atomic(page, KM_USER0);
1907 memset(userpage + page_offset, 0, iosize);
1908 flush_dcache_page(page);
1909 kunmap_atomic(userpage, KM_USER0);
1910
1911 set_extent_uptodate(tree, cur, cur + iosize - 1,
1912 GFP_NOFS);
1913 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1914 cur = cur + iosize;
1915 page_offset += iosize;
1916 continue;
1917 }
1918 /* the get_extent function already copied into the page */
1919 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
1920 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1921 cur = cur + iosize;
1922 page_offset += iosize;
1923 continue;
1924 }
70dec807
CM		 1925 /* we have an inline extent but it didn't get marked up
1926 * to date. Error out
1927 */
1928 if (block_start == EXTENT_MAP_INLINE) {
1929 SetPageError(page);
1930 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1931 cur = cur + iosize;
1932 page_offset += iosize;
1933 continue;
1934 }
d1310b2e
CM		 1935
1936 ret = 0;
1937 if (tree->ops && tree->ops->readpage_io_hook) {
1938 ret = tree->ops->readpage_io_hook(page, cur,
1939 cur + iosize - 1);
1940 }
1941 if (!ret) {
1942 unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
1943 nr -= page->index;
1944 ret = submit_extent_page(READ, tree, page,
1945 sector, iosize, page_offset,
1946 bdev, bio, nr,
f188591e 1947 end_bio_extent_readpage, mirror_num);
d1310b2e
CM		 1948 }
1949 if (ret)
1950 SetPageError(page);
1951 cur = cur + iosize;
1952 page_offset += iosize;
1953 nr++;
1954 }
1955 if (!nr) {
1956 if (!PageError(page))
1957 SetPageUptodate(page);
1958 unlock_page(page);
1959 }
1960 return 0;
1961}
1962
1963int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
1964 get_extent_t *get_extent)
1965{
1966 struct bio *bio = NULL;
1967 int ret;
1968
f188591e 1969 ret = __extent_read_full_page(tree, page, get_extent, &bio, 0);
d1310b2e 1970 if (bio)
f188591e 1971 submit_one_bio(READ, bio, 0);
d1310b2e
CM		 1972 return ret;
1973}
1974EXPORT_SYMBOL(extent_read_full_page);
1975
1976/*
1977 * the writepage semantics are similar to regular writepage. extent
1978 * records are inserted to lock ranges in the tree, and as dirty areas
1979 * are found, they are marked writeback. Then the lock bits are removed
1980 * and the end_io handler clears the writeback ranges
1981 */
1982static int __extent_writepage(struct page *page, struct writeback_control *wbc,
1983 void *data)
1984{
1985 struct inode *inode = page->mapping->host;
1986 struct extent_page_data *epd = data;
1987 struct extent_io_tree *tree = epd->tree;
1988 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1989 u64 delalloc_start;
1990 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1991 u64 end;
1992 u64 cur = start;
1993 u64 extent_offset;
1994 u64 last_byte = i_size_read(inode);
1995 u64 block_start;
1996 u64 iosize;
e6dcd2dc 1997 u64 unlock_start;
d1310b2e
CM		 1998 sector_t sector;
1999 struct extent_map *em;
2000 struct block_device *bdev;
2001 int ret;
2002 int nr = 0;
7f3c74fb 2003 size_t pg_offset = 0;
d1310b2e
CM		 2004 size_t blocksize;
2005 loff_t i_size = i_size_read(inode);
2006 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2007 u64 nr_delalloc;
2008 u64 delalloc_end;
2009
2010 WARN_ON(!PageLocked(page));
7f3c74fb 2011 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
211c17f5 2012 if (page->index > end_index ||
7f3c74fb 2013 (page->index == end_index && !pg_offset)) {
211c17f5 2014 page->mapping->a_ops->invalidatepage(page, 0);
d1310b2e
CM		 2015 unlock_page(page);
2016 return 0;
2017 }
2018
2019 if (page->index == end_index) {
2020 char *userpage;
2021
d1310b2e 2022 userpage = kmap_atomic(page, KM_USER0);
7f3c74fb
CM		 2023 memset(userpage + pg_offset, 0,
2024 PAGE_CACHE_SIZE - pg_offset);
d1310b2e 2025 kunmap_atomic(userpage, KM_USER0);
211c17f5 2026 flush_dcache_page(page);
d1310b2e 2027 }
7f3c74fb 2028 pg_offset = 0;
d1310b2e
CM		 2029
2030 set_page_extent_mapped(page);
2031
2032 delalloc_start = start;
2033 delalloc_end = 0;
2034 while(delalloc_end < page_end) {
2035 nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start,
2036 &delalloc_end,
2037 128 * 1024 * 1024);
2038 if (nr_delalloc == 0) {
2039 delalloc_start = delalloc_end + 1;
2040 continue;
2041 }
2042 tree->ops->fill_delalloc(inode, delalloc_start,
2043 delalloc_end);
2044 clear_extent_bit(tree, delalloc_start,
2045 delalloc_end,
2046 EXTENT_LOCKED | EXTENT_DELALLOC,
2047 1, 0, GFP_NOFS);
2048 delalloc_start = delalloc_end + 1;
2049 }
2050 lock_extent(tree, start, page_end, GFP_NOFS);
e6dcd2dc 2051 unlock_start = start;
d1310b2e 2052
247e743c
CM		 2053 if (tree->ops && tree->ops->writepage_start_hook) {
2054 ret = tree->ops->writepage_start_hook(page, start, page_end);
2055 if (ret == -EAGAIN) {
2056 unlock_extent(tree, start, page_end, GFP_NOFS);
2057 redirty_page_for_writepage(wbc, page);
2058 unlock_page(page);
2059 return 0;
2060 }
2061 }
2062
d1310b2e
CM		 2063 end = page_end;
2064 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
2065 printk("found delalloc bits after lock_extent\n");
2066 }
2067
2068 if (last_byte <= start) {
2069 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
e6dcd2dc
CM		 2070 unlock_extent(tree, start, page_end, GFP_NOFS);
2071 if (tree->ops && tree->ops->writepage_end_io_hook)
2072 tree->ops->writepage_end_io_hook(page, start,
2073 page_end, NULL, 1);
2074 unlock_start = page_end + 1;
d1310b2e
CM		 2075 goto done;
2076 }
2077
2078 set_extent_uptodate(tree, start, page_end, GFP_NOFS);
2079 blocksize = inode->i_sb->s_blocksize;
2080
2081 while (cur <= end) {
2082 if (cur >= last_byte) {
2083 clear_extent_dirty(tree, cur, page_end, GFP_NOFS);
e6dcd2dc
CM		 2084 unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
2085 if (tree->ops && tree->ops->writepage_end_io_hook)
2086 tree->ops->writepage_end_io_hook(page, cur,
2087 page_end, NULL, 1);
2088 unlock_start = page_end + 1;
d1310b2e
CM		 2089 break;
2090 }
7f3c74fb 2091 em = epd->get_extent(inode, page, pg_offset, cur,
d1310b2e
CM		 2092 end - cur + 1, 1);
2093 if (IS_ERR(em) || !em) {
2094 SetPageError(page);
2095 break;
2096 }
2097
2098 extent_offset = cur - em->start;
2099 BUG_ON(extent_map_end(em) <= cur);
2100 BUG_ON(end < cur);
2101 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2102 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2103 sector = (em->block_start + extent_offset) >> 9;
2104 bdev = em->bdev;
2105 block_start = em->block_start;
2106 free_extent_map(em);
2107 em = NULL;
2108
2109 if (block_start == EXTENT_MAP_HOLE ||
2110 block_start == EXTENT_MAP_INLINE) {
2111 clear_extent_dirty(tree, cur,
2112 cur + iosize - 1, GFP_NOFS);
e6dcd2dc
CM		 2113
2114 unlock_extent(tree, unlock_start, cur + iosize -1,
2115 GFP_NOFS);
7f3c74fb 2116
e6dcd2dc
CM		 2117 if (tree->ops && tree->ops->writepage_end_io_hook)
2118 tree->ops->writepage_end_io_hook(page, cur,
2119 cur + iosize - 1,
2120 NULL, 1);
d1310b2e 2121 cur = cur + iosize;
7f3c74fb 2122 pg_offset += iosize;
e6dcd2dc 2123 unlock_start = cur;
d1310b2e
CM		 2124 continue;
2125 }
2126
2127 /* leave this out until we have a page_mkwrite call */
2128 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2129 EXTENT_DIRTY, 0)) {
2130 cur = cur + iosize;
7f3c74fb 2131 pg_offset += iosize;
d1310b2e
CM		 2132 continue;
2133 }
2134 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
2135 if (tree->ops && tree->ops->writepage_io_hook) {
2136 ret = tree->ops->writepage_io_hook(page, cur,
2137 cur + iosize - 1);
2138 } else {
2139 ret = 0;
2140 }
1259ab75 2141 if (ret) {
d1310b2e 2142 SetPageError(page);
1259ab75 2143 } else {
d1310b2e 2144 unsigned long max_nr = end_index + 1;
7f3c74fb 2145
d1310b2e
CM		 2146 set_range_writeback(tree, cur, cur + iosize - 1);
2147 if (!PageWriteback(page)) {
2148 printk("warning page %lu not writeback, "
2149 "cur %llu end %llu\n", page->index,
2150 (unsigned long long)cur,
2151 (unsigned long long)end);
2152 }
2153
2154 ret = submit_extent_page(WRITE, tree, page, sector,
7f3c74fb 2155 iosize, pg_offset, bdev,
d1310b2e 2156 &epd->bio, max_nr,
f188591e 2157 end_bio_extent_writepage, 0);
d1310b2e
CM		 2158 if (ret)
2159 SetPageError(page);
2160 }
2161 cur = cur + iosize;
7f3c74fb 2162 pg_offset += iosize;
d1310b2e
CM		 2163 nr++;
2164 }
2165done:
2166 if (nr == 0) {
2167 /* make sure the mapping tag for page dirty gets cleared */
2168 set_page_writeback(page);
2169 end_page_writeback(page);
2170 }
e6dcd2dc
CM		 2171 if (unlock_start <= page_end)
2172 unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
d1310b2e
CM		 2173 unlock_page(page);
2174 return 0;
2175}
2176
5e478dc9 2177#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
d1310b2e
CM		 2178/* Taken directly from 2.6.23 for 2.6.18 back port */
2179typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
2180 void *data);
2181
2182/**
2183 * write_cache_pages - walk the list of dirty pages of the given address space
2184 * and write all of them.
2185 * @mapping: address space structure to write
2186 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2187 * @writepage: function called for each page
2188 * @data: data passed to writepage function
2189 *
2190 * If a page is already under I/O, write_cache_pages() skips it, even
2191 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2192 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2193 * and msync() need to guarantee that all the data which was dirty at the time
2194 * the call was made get new I/O started against them. If wbc->sync_mode is
2195 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2196 * existing IO to complete.
2197 */
2198static int write_cache_pages(struct address_space *mapping,
2199 struct writeback_control *wbc, writepage_t writepage,
2200 void *data)
2201{
2202 struct backing_dev_info *bdi = mapping->backing_dev_info;
2203 int ret = 0;
2204 int done = 0;
2205 struct pagevec pvec;
2206 int nr_pages;
2207 pgoff_t index;
2208 pgoff_t end; /* Inclusive */
2209 int scanned = 0;
2210 int range_whole = 0;
2211
2212 if (wbc->nonblocking && bdi_write_congested(bdi)) {
2213 wbc->encountered_congestion = 1;
2214 return 0;
2215 }
2216
2217 pagevec_init(&pvec, 0);
2218 if (wbc->range_cyclic) {
2219 index = mapping->writeback_index; /* Start from prev offset */
2220 end = -1;
2221 } else {
2222 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2223 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2224 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2225 range_whole = 1;
2226 scanned = 1;
2227 }
2228retry:
2229 while (!done && (index <= end) &&
2230 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
2231 PAGECACHE_TAG_DIRTY,
2232 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
2233 unsigned i;
2234
2235 scanned = 1;
2236 for (i = 0; i < nr_pages; i++) {
2237 struct page *page = pvec.pages[i];
2238
2239 /*
2240 * At this point we hold neither mapping->tree_lock nor
2241 * lock on the page itself: the page may be truncated or
2242 * invalidated (changing page->mapping to NULL), or even
2243 * swizzled back from swapper_space to tmpfs file
2244 * mapping
2245 */
2246 lock_page(page);
2247
2248 if (unlikely(page->mapping != mapping)) {
2249 unlock_page(page);
2250 continue;
2251 }
2252
2253 if (!wbc->range_cyclic && page->index > end) {
2254 done = 1;
2255 unlock_page(page);
2256 continue;
2257 }
2258
2259 if (wbc->sync_mode != WB_SYNC_NONE)
2260 wait_on_page_writeback(page);
2261
2262 if (PageWriteback(page) ||
2263 !clear_page_dirty_for_io(page)) {
2264 unlock_page(page);
2265 continue;
2266 }
2267
2268 ret = (*writepage)(page, wbc, data);
2269
2270 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
2271 unlock_page(page);
2272 ret = 0;
2273 }
2274 if (ret || (--(wbc->nr_to_write) <= 0))
2275 done = 1;
2276 if (wbc->nonblocking && bdi_write_congested(bdi)) {
2277 wbc->encountered_congestion = 1;
2278 done = 1;
2279 }
2280 }
2281 pagevec_release(&pvec);
2282 cond_resched();
2283 }
2284 if (!scanned && !done) {
2285 /*
2286 * We hit the last page and there is more work to be done: wrap
2287 * back to the start of the file
2288 */
2289 scanned = 1;
2290 index = 0;
2291 goto retry;
2292 }
2293 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2294 mapping->writeback_index = index;
2295 return ret;
2296}
2297#endif
2298
2299int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
2300 get_extent_t *get_extent,
2301 struct writeback_control *wbc)
2302{
2303 int ret;
2304 struct address_space *mapping = page->mapping;
2305 struct extent_page_data epd = {
2306 .bio = NULL,
2307 .tree = tree,
2308 .get_extent = get_extent,
2309 };
2310 struct writeback_control wbc_writepages = {
2311 .bdi = wbc->bdi,
2312 .sync_mode = WB_SYNC_NONE,
2313 .older_than_this = NULL,
2314 .nr_to_write = 64,
2315 .range_start = page_offset(page) + PAGE_CACHE_SIZE,
2316 .range_end = (loff_t)-1,
2317 };
2318
2319
2320 ret = __extent_writepage(page, wbc, &epd);
2321
2322 write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd);
2323 if (epd.bio) {
f188591e 2324 submit_one_bio(WRITE, epd.bio, 0);
d1310b2e
CM		 2325 }
2326 return ret;
2327}
2328EXPORT_SYMBOL(extent_write_full_page);
2329
2330
2331int extent_writepages(struct extent_io_tree *tree,
2332 struct address_space *mapping,
2333 get_extent_t *get_extent,
2334 struct writeback_control *wbc)
2335{
2336 int ret = 0;
2337 struct extent_page_data epd = {
2338 .bio = NULL,
2339 .tree = tree,
2340 .get_extent = get_extent,
2341 };
2342
2343 ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd);
2344 if (epd.bio) {
f188591e 2345 submit_one_bio(WRITE, epd.bio, 0);
d1310b2e
CM		 2346 }
2347 return ret;
2348}
2349EXPORT_SYMBOL(extent_writepages);
2350
2351int extent_readpages(struct extent_io_tree *tree,
2352 struct address_space *mapping,
2353 struct list_head *pages, unsigned nr_pages,
2354 get_extent_t get_extent)
2355{
2356 struct bio *bio = NULL;
2357 unsigned page_idx;
2358 struct pagevec pvec;
2359
2360 pagevec_init(&pvec, 0);
2361 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
2362 struct page *page = list_entry(pages->prev, struct page, lru);
2363
2364 prefetchw(&page->flags);
2365 list_del(&page->lru);
2366 /*
2367 * what we want to do here is call add_to_page_cache_lru,
2368 * but that isn't exported, so we reproduce it here
2369 */
2370 if (!add_to_page_cache(page, mapping,
2371 page->index, GFP_KERNEL)) {
2372
2373 /* open coding of lru_cache_add, also not exported */
2374 page_cache_get(page);
2375 if (!pagevec_add(&pvec, page))
2376 __pagevec_lru_add(&pvec);
f188591e
CM		 2377 __extent_read_full_page(tree, page, get_extent,
2378 &bio, 0);
d1310b2e
CM		 2379 }
2380 page_cache_release(page);
2381 }
2382 if (pagevec_count(&pvec))
2383 __pagevec_lru_add(&pvec);
2384 BUG_ON(!list_empty(pages));
2385 if (bio)
f188591e 2386 submit_one_bio(READ, bio, 0);
d1310b2e
CM		 2387 return 0;
2388}
2389EXPORT_SYMBOL(extent_readpages);
2390
2391/*
2392 * basic invalidatepage code, this waits on any locked or writeback
2393 * ranges corresponding to the page, and then deletes any extent state
2394 * records from the tree
2395 */
2396int extent_invalidatepage(struct extent_io_tree *tree,
2397 struct page *page, unsigned long offset)
2398{
2399 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
2400 u64 end = start + PAGE_CACHE_SIZE - 1;
2401 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
2402
2403 start += (offset + blocksize -1) & ~(blocksize - 1);
2404 if (start > end)
2405 return 0;
2406
2407 lock_extent(tree, start, end, GFP_NOFS);
2408 wait_on_extent_writeback(tree, start, end);
2409 clear_extent_bit(tree, start, end,
2410 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
2411 1, 1, GFP_NOFS);
2412 return 0;
2413}
2414EXPORT_SYMBOL(extent_invalidatepage);
2415
2416/*
2417 * simple commit_write call, set_range_dirty is used to mark both
2418 * the pages and the extent records as dirty
2419 */
2420int extent_commit_write(struct extent_io_tree *tree,
2421 struct inode *inode, struct page *page,
2422 unsigned from, unsigned to)
2423{
2424 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
2425
2426 set_page_extent_mapped(page);
2427 set_page_dirty(page);
2428
2429 if (pos > inode->i_size) {
2430 i_size_write(inode, pos);
2431 mark_inode_dirty(inode);
2432 }
2433 return 0;
2434}
2435EXPORT_SYMBOL(extent_commit_write);
2436
2437int extent_prepare_write(struct extent_io_tree *tree,
2438 struct inode *inode, struct page *page,
2439 unsigned from, unsigned to, get_extent_t *get_extent)
2440{
2441 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2442 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
2443 u64 block_start;
2444 u64 orig_block_start;
2445 u64 block_end;
2446 u64 cur_end;
2447 struct extent_map *em;
2448 unsigned blocksize = 1 << inode->i_blkbits;
2449 size_t page_offset = 0;
2450 size_t block_off_start;
2451 size_t block_off_end;
2452 int err = 0;
2453 int iocount = 0;
2454 int ret = 0;
2455 int isnew;
2456
2457 set_page_extent_mapped(page);
2458
2459 block_start = (page_start + from) & ~((u64)blocksize - 1);
2460 block_end = (page_start + to - 1) | (blocksize - 1);
2461 orig_block_start = block_start;
2462
2463 lock_extent(tree, page_start, page_end, GFP_NOFS);
2464 while(block_start <= block_end) {
2465 em = get_extent(inode, page, page_offset, block_start,
2466 block_end - block_start + 1, 1);
2467 if (IS_ERR(em) || !em) {
2468 goto err;
2469 }
2470 cur_end = min(block_end, extent_map_end(em) - 1);
2471 block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
2472 block_off_end = block_off_start + blocksize;
2473 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
2474
2475 if (!PageUptodate(page) && isnew &&
2476 (block_off_end > to || block_off_start < from)) {
2477 void *kaddr;
2478
2479 kaddr = kmap_atomic(page, KM_USER0);
2480 if (block_off_end > to)
2481 memset(kaddr + to, 0, block_off_end - to);
2482 if (block_off_start < from)
2483 memset(kaddr + block_off_start, 0,
2484 from - block_off_start);
2485 flush_dcache_page(page);
2486 kunmap_atomic(kaddr, KM_USER0);
2487 }
2488 if ((em->block_start != EXTENT_MAP_HOLE &&
2489 em->block_start != EXTENT_MAP_INLINE) &&
2490 !isnew && !PageUptodate(page) &&
2491 (block_off_end > to || block_off_start < from) &&
2492 !test_range_bit(tree, block_start, cur_end,
2493 EXTENT_UPTODATE, 1)) {
2494 u64 sector;
2495 u64 extent_offset = block_start - em->start;
2496 size_t iosize;
2497 sector = (em->block_start + extent_offset) >> 9;
2498 iosize = (cur_end - block_start + blocksize) &
2499 ~((u64)blocksize - 1);
2500 /*
2501 * we've already got the extent locked, but we
2502 * need to split the state such that our end_bio
2503 * handler can clear the lock.
2504 */
2505 set_extent_bit(tree, block_start,
2506 block_start + iosize - 1,
2507 EXTENT_LOCKED, 0, NULL, GFP_NOFS);
2508 ret = submit_extent_page(READ, tree, page,
2509 sector, iosize, page_offset, em->bdev,
2510 NULL, 1,
f188591e 2511 end_bio_extent_preparewrite, 0);
d1310b2e
CM		 2512 iocount++;
2513 block_start = block_start + iosize;
2514 } else {
2515 set_extent_uptodate(tree, block_start, cur_end,
2516 GFP_NOFS);
2517 unlock_extent(tree, block_start, cur_end, GFP_NOFS);
2518 block_start = cur_end + 1;
2519 }
2520 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
2521 free_extent_map(em);
2522 }
2523 if (iocount) {
2524 wait_extent_bit(tree, orig_block_start,
2525 block_end, EXTENT_LOCKED);
2526 }
2527 check_page_uptodate(tree, page);
2528err:
2529 /* FIXME, zero out newly allocated blocks on error */
2530 return err;
2531}
2532EXPORT_SYMBOL(extent_prepare_write);
2533
7b13b7b1
CM		 2534/*
2535 * a helper for releasepage, this tests for areas of the page that
2536 * are locked or under IO and drops the related state bits if it is safe
2537 * to drop the page.
2538 */
2539int try_release_extent_state(struct extent_map_tree *map,
2540 struct extent_io_tree *tree, struct page *page,
2541 gfp_t mask)
2542{
2543 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2544 u64 end = start + PAGE_CACHE_SIZE - 1;
2545 int ret = 1;
2546
211f90e6
CM		 2547 if (test_range_bit(tree, start, end,
2548 EXTENT_IOBITS | EXTENT_ORDERED, 0))
7b13b7b1
CM		 2549 ret = 0;
2550 else {
2551 if ((mask & GFP_NOFS) == GFP_NOFS)
2552 mask = GFP_NOFS;
2553 clear_extent_bit(tree, start, end, EXTENT_UPTODATE,
2554 1, 1, mask);
2555 }
2556 return ret;
2557}
2558EXPORT_SYMBOL(try_release_extent_state);
2559
d1310b2e
CM		 2560/*
2561 * a helper for releasepage. As long as there are no locked extents
2562 * in the range corresponding to the page, both state records and extent
2563 * map records are removed
2564 */
2565int try_release_extent_mapping(struct extent_map_tree *map,
70dec807
CM		 2566 struct extent_io_tree *tree, struct page *page,
2567 gfp_t mask)
d1310b2e
CM		 2568{
2569 struct extent_map *em;
2570 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2571 u64 end = start + PAGE_CACHE_SIZE - 1;
7b13b7b1 2572
70dec807
CM		 2573 if ((mask & __GFP_WAIT) &&
2574 page->mapping->host->i_size > 16 * 1024 * 1024) {
39b5637f 2575 u64 len;
70dec807 2576 while (start <= end) {
39b5637f 2577 len = end - start + 1;
70dec807 2578 spin_lock(&map->lock);
39b5637f 2579 em = lookup_extent_mapping(map, start, len);
70dec807
CM		 2580 if (!em || IS_ERR(em)) {
2581 spin_unlock(&map->lock);
2582 break;
2583 }
7f3c74fb
CM		 2584 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
2585 em->start != start) {
70dec807
CM		 2586 spin_unlock(&map->lock);
2587 free_extent_map(em);
2588 break;
2589 }
2590 if (!test_range_bit(tree, em->start,
2591 extent_map_end(em) - 1,
2592 EXTENT_LOCKED, 0)) {
2593 remove_extent_mapping(map, em);
2594 /* once for the rb tree */
2595 free_extent_map(em);
2596 }
2597 start = extent_map_end(em);
d1310b2e 2598 spin_unlock(&map->lock);
70dec807
CM		 2599
2600 /* once for us */
d1310b2e
CM		 2601 free_extent_map(em);
2602 }
d1310b2e 2603 }
7b13b7b1 2604 return try_release_extent_state(map, tree, page, mask);
d1310b2e
CM		 2605}
2606EXPORT_SYMBOL(try_release_extent_mapping);
2607
2608sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
2609 get_extent_t *get_extent)
2610{
2611 struct inode *inode = mapping->host;
2612 u64 start = iblock << inode->i_blkbits;
2613 sector_t sector = 0;
2614 struct extent_map *em;
2615
2616 em = get_extent(inode, NULL, 0, start, (1 << inode->i_blkbits), 0);
2617 if (!em || IS_ERR(em))
2618 return 0;
2619
2620 if (em->block_start == EXTENT_MAP_INLINE ||
2621 em->block_start == EXTENT_MAP_HOLE)
2622 goto out;
2623
2624 sector = (em->block_start + start - em->start) >> inode->i_blkbits;
d1310b2e
CM		 2625out:
2626 free_extent_map(em);
2627 return sector;
2628}
2629
2630static int add_lru(struct extent_io_tree *tree, struct extent_buffer *eb)
2631{
2632 if (list_empty(&eb->lru)) {
2633 extent_buffer_get(eb);
2634 list_add(&eb->lru, &tree->buffer_lru);
2635 tree->lru_size++;
2636 if (tree->lru_size >= BUFFER_LRU_MAX) {
2637 struct extent_buffer *rm;
2638 rm = list_entry(tree->buffer_lru.prev,
2639 struct extent_buffer, lru);
2640 tree->lru_size--;
2641 list_del_init(&rm->lru);
2642 free_extent_buffer(rm);
2643 }
2644 } else
2645 list_move(&eb->lru, &tree->buffer_lru);
2646 return 0;
2647}
2648static struct extent_buffer *find_lru(struct extent_io_tree *tree,
2649 u64 start, unsigned long len)
2650{
2651 struct list_head *lru = &tree->buffer_lru;
2652 struct list_head *cur = lru->next;
2653 struct extent_buffer *eb;
2654
2655 if (list_empty(lru))
2656 return NULL;
2657
2658 do {
2659 eb = list_entry(cur, struct extent_buffer, lru);
2660 if (eb->start == start && eb->len == len) {
2661 extent_buffer_get(eb);
2662 return eb;
2663 }
2664 cur = cur->next;
2665 } while (cur != lru);
2666 return NULL;
2667}
2668
2669static inline unsigned long num_extent_pages(u64 start, u64 len)
2670{
2671 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
2672 (start >> PAGE_CACHE_SHIFT);
2673}
2674
2675static inline struct page *extent_buffer_page(struct extent_buffer *eb,
2676 unsigned long i)
2677{
2678 struct page *p;
2679 struct address_space *mapping;
2680
2681 if (i == 0)
2682 return eb->first_page;
2683 i += eb->start >> PAGE_CACHE_SHIFT;
2684 mapping = eb->first_page->mapping;
2685 read_lock_irq(&mapping->tree_lock);
2686 p = radix_tree_lookup(&mapping->page_tree, i);
2687 read_unlock_irq(&mapping->tree_lock);
2688 return p;
2689}
2690
ce9adaa5
CM		 2691int release_extent_buffer_tail_pages(struct extent_buffer *eb)
2692{
2693 unsigned long num_pages = num_extent_pages(eb->start, eb->len);
2694 struct page *page;
2695 unsigned long i;
2696
2697 if (num_pages == 1)
2698 return 0;
2699 for (i = 1; i < num_pages; i++) {
2700 page = extent_buffer_page(eb, i);
2701 page_cache_release(page);
2702 }
2703 return 0;
2704}
2705
2706
728131d8
CM		 2707int invalidate_extent_lru(struct extent_io_tree *tree, u64 start,
2708 unsigned long len)
2709{
2710 struct list_head *lru = &tree->buffer_lru;
2711 struct list_head *cur = lru->next;
2712 struct extent_buffer *eb;
2713 int found = 0;
2714
2715 spin_lock(&tree->lru_lock);
2716 if (list_empty(lru))
2717 goto out;
2718
2719 do {
2720 eb = list_entry(cur, struct extent_buffer, lru);
2721 if (eb->start <= start && eb->start + eb->len > start) {
2722 eb->flags &= ~EXTENT_UPTODATE;
2723 }
728131d8
CM		 2724 cur = cur->next;
2725 } while (cur != lru);
2726out:
2727 spin_unlock(&tree->lru_lock);
2728 return found;
2729}
2730
d1310b2e
CM		 2731static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
2732 u64 start,
2733 unsigned long len,
2734 gfp_t mask)
2735{
2736 struct extent_buffer *eb = NULL;
2d2ae547 2737 unsigned long flags;
d1310b2e
CM		 2738
2739 spin_lock(&tree->lru_lock);
2740 eb = find_lru(tree, start, len);
2741 spin_unlock(&tree->lru_lock);
2742 if (eb) {
2743 return eb;
2744 }
2745
2746 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
2747 INIT_LIST_HEAD(&eb->lru);
2748 eb->start = start;
2749 eb->len = len;
2d2ae547
CM		 2750 spin_lock_irqsave(&leak_lock, flags);
2751 list_add(&eb->leak_list, &buffers);
2752 spin_unlock_irqrestore(&leak_lock, flags);
d1310b2e
CM		 2753 atomic_set(&eb->refs, 1);
2754
2755 return eb;
2756}
2757
2758static void __free_extent_buffer(struct extent_buffer *eb)
2759{
2d2ae547
CM		 2760 unsigned long flags;
2761 spin_lock_irqsave(&leak_lock, flags);
2762 list_del(&eb->leak_list);
2763 spin_unlock_irqrestore(&leak_lock, flags);
d1310b2e
CM		 2764 kmem_cache_free(extent_buffer_cache, eb);
2765}
2766
2767struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
2768 u64 start, unsigned long len,
2769 struct page *page0,
2770 gfp_t mask)
2771{
2772 unsigned long num_pages = num_extent_pages(start, len);
2773 unsigned long i;
2774 unsigned long index = start >> PAGE_CACHE_SHIFT;
2775 struct extent_buffer *eb;
2776 struct page *p;
2777 struct address_space *mapping = tree->mapping;
2778 int uptodate = 1;
2779
2780 eb = __alloc_extent_buffer(tree, start, len, mask);
2b114d1d 2781 if (!eb)
d1310b2e
CM		 2782 return NULL;
2783
2784 if (eb->flags & EXTENT_BUFFER_FILLED)
2785 goto lru_add;
2786
2787 if (page0) {
2788 eb->first_page = page0;
2789 i = 1;
2790 index++;
2791 page_cache_get(page0);
2792 mark_page_accessed(page0);
2793 set_page_extent_mapped(page0);
d1310b2e 2794 set_page_extent_head(page0, len);
f188591e 2795 uptodate = PageUptodate(page0);
d1310b2e
CM		 2796 } else {
2797 i = 0;
2798 }
2799 for (; i < num_pages; i++, index++) {
2800 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
2801 if (!p) {
2802 WARN_ON(1);
2803 goto fail;
2804 }
2805 set_page_extent_mapped(p);
2806 mark_page_accessed(p);
2807 if (i == 0) {
2808 eb->first_page = p;
2809 set_page_extent_head(p, len);
2810 } else {
2811 set_page_private(p, EXTENT_PAGE_PRIVATE);
2812 }
2813 if (!PageUptodate(p))
2814 uptodate = 0;
2815 unlock_page(p);
2816 }
2817 if (uptodate)
2818 eb->flags |= EXTENT_UPTODATE;
2819 eb->flags |= EXTENT_BUFFER_FILLED;
2820
2821lru_add:
2822 spin_lock(&tree->lru_lock);
2823 add_lru(tree, eb);
2824 spin_unlock(&tree->lru_lock);
2825 return eb;
2826
2827fail:
2828 spin_lock(&tree->lru_lock);
2829 list_del_init(&eb->lru);
2830 spin_unlock(&tree->lru_lock);
2831 if (!atomic_dec_and_test(&eb->refs))
2832 return NULL;
2833 for (index = 1; index < i; index++) {
2834 page_cache_release(extent_buffer_page(eb, index));
2835 }
2836 if (i > 0)
2837 page_cache_release(extent_buffer_page(eb, 0));
2838 __free_extent_buffer(eb);
2839 return NULL;
2840}
2841EXPORT_SYMBOL(alloc_extent_buffer);
2842
2843struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
2844 u64 start, unsigned long len,
2845 gfp_t mask)
2846{
2847 unsigned long num_pages = num_extent_pages(start, len);
2848 unsigned long i;
2849 unsigned long index = start >> PAGE_CACHE_SHIFT;
2850 struct extent_buffer *eb;
2851 struct page *p;
2852 struct address_space *mapping = tree->mapping;
2853 int uptodate = 1;
2854
2855 eb = __alloc_extent_buffer(tree, start, len, mask);
2b114d1d 2856 if (!eb)
d1310b2e
CM		 2857 return NULL;
2858
2859 if (eb->flags & EXTENT_BUFFER_FILLED)
2860 goto lru_add;
2861
2862 for (i = 0; i < num_pages; i++, index++) {
079899c2 2863 p = find_get_page(mapping, index);
d1310b2e
CM		 2864 if (!p) {
2865 goto fail;
2866 }
079899c2
CM		 2867 if (TestSetPageLocked(p)) {
2868 page_cache_release(p);
2869 goto fail;
2870 }
2871
d1310b2e
CM		 2872 set_page_extent_mapped(p);
2873 mark_page_accessed(p);
2874
2875 if (i == 0) {
2876 eb->first_page = p;
2877 set_page_extent_head(p, len);
2878 } else {
2879 set_page_private(p, EXTENT_PAGE_PRIVATE);
2880 }
2881
2882 if (!PageUptodate(p))
2883 uptodate = 0;
2884 unlock_page(p);
2885 }
2886 if (uptodate)
2887 eb->flags |= EXTENT_UPTODATE;
2888 eb->flags |= EXTENT_BUFFER_FILLED;
2889
2890lru_add:
2891 spin_lock(&tree->lru_lock);
2892 add_lru(tree, eb);
2893 spin_unlock(&tree->lru_lock);
2894 return eb;
2895fail:
2896 spin_lock(&tree->lru_lock);
2897 list_del_init(&eb->lru);
2898 spin_unlock(&tree->lru_lock);
2899 if (!atomic_dec_and_test(&eb->refs))
2900 return NULL;
2901 for (index = 1; index < i; index++) {
2902 page_cache_release(extent_buffer_page(eb, index));
2903 }
2904 if (i > 0)
2905 page_cache_release(extent_buffer_page(eb, 0));
2906 __free_extent_buffer(eb);
2907 return NULL;
2908}
2909EXPORT_SYMBOL(find_extent_buffer);
2910
2911void free_extent_buffer(struct extent_buffer *eb)
2912{
2913 unsigned long i;
2914 unsigned long num_pages;
2915
2916 if (!eb)
2917 return;
2918
2919 if (!atomic_dec_and_test(&eb->refs))
2920 return;
2921
2922 WARN_ON(!list_empty(&eb->lru));
2923 num_pages = num_extent_pages(eb->start, eb->len);
2924
2925 for (i = 1; i < num_pages; i++) {
2926 page_cache_release(extent_buffer_page(eb, i));
2927 }
2928 page_cache_release(extent_buffer_page(eb, 0));
2929 __free_extent_buffer(eb);
2930}
2931EXPORT_SYMBOL(free_extent_buffer);
2932
2933int clear_extent_buffer_dirty(struct extent_io_tree *tree,
2934 struct extent_buffer *eb)
2935{
2936 int set;
2937 unsigned long i;
2938 unsigned long num_pages;
2939 struct page *page;
2940
2941 u64 start = eb->start;
2942 u64 end = start + eb->len - 1;
2943
2944 set = clear_extent_dirty(tree, start, end, GFP_NOFS);
2945 num_pages = num_extent_pages(eb->start, eb->len);
2946
2947 for (i = 0; i < num_pages; i++) {
2948 page = extent_buffer_page(eb, i);
d1310b2e
CM		 2949 if (i == 0)
2950 set_page_extent_head(page, eb->len);
2951 else
2952 set_page_private(page, EXTENT_PAGE_PRIVATE);
2953
2954 /*
2955 * if we're on the last page or the first page and the
2956 * block isn't aligned on a page boundary, do extra checks
2957 * to make sure we don't clean page that is partially dirty
2958 */
2959 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
2960 ((i == num_pages - 1) &&
2961 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
2962 start = (u64)page->index << PAGE_CACHE_SHIFT;
2963 end = start + PAGE_CACHE_SIZE - 1;
2964 if (test_range_bit(tree, start, end,
2965 EXTENT_DIRTY, 0)) {
d1310b2e
CM		 2966 continue;
2967 }
2968 }
2969 clear_page_dirty_for_io(page);
70dec807 2970 read_lock_irq(&page->mapping->tree_lock);
d1310b2e
CM		 2971 if (!PageDirty(page)) {
2972 radix_tree_tag_clear(&page->mapping->page_tree,
2973 page_index(page),
2974 PAGECACHE_TAG_DIRTY);
2975 }
70dec807 2976 read_unlock_irq(&page->mapping->tree_lock);
d1310b2e
CM		 2977 }
2978 return 0;
2979}
2980EXPORT_SYMBOL(clear_extent_buffer_dirty);
2981
2982int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
2983 struct extent_buffer *eb)
2984{
2985 return wait_on_extent_writeback(tree, eb->start,
2986 eb->start + eb->len - 1);
2987}
2988EXPORT_SYMBOL(wait_on_extent_buffer_writeback);
2989
2990int set_extent_buffer_dirty(struct extent_io_tree *tree,
2991 struct extent_buffer *eb)
2992{
2993 unsigned long i;
2994 unsigned long num_pages;
2995
2996 num_pages = num_extent_pages(eb->start, eb->len);
2997 for (i = 0; i < num_pages; i++) {
2998 struct page *page = extent_buffer_page(eb, i);
2999 /* writepage may need to do something special for the
3000 * first page, we have to make sure page->private is
3001 * properly set. releasepage may drop page->private
3002 * on us if the page isn't already dirty.
3003 */
3004 if (i == 0) {
d1310b2e
CM		 3005 set_page_extent_head(page, eb->len);
3006 } else if (PagePrivate(page) &&
3007 page->private != EXTENT_PAGE_PRIVATE) {
d1310b2e 3008 set_page_extent_mapped(page);
d1310b2e
CM		 3009 }
3010 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
d1310b2e
CM		 3011 }
3012 return set_extent_dirty(tree, eb->start,
3013 eb->start + eb->len - 1, GFP_NOFS);
3014}
3015EXPORT_SYMBOL(set_extent_buffer_dirty);
3016
1259ab75
CM		 3017int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
3018 struct extent_buffer *eb)
3019{
3020 unsigned long i;
3021 struct page *page;
3022 unsigned long num_pages;
3023
3024 num_pages = num_extent_pages(eb->start, eb->len);
3025 eb->flags &= ~EXTENT_UPTODATE;
3026
3027 clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3028 GFP_NOFS);
3029 for (i = 0; i < num_pages; i++) {
3030 page = extent_buffer_page(eb, i);
3031 ClearPageUptodate(page);
3032 }
3033 return 0;
3034}
3035
d1310b2e
CM		 3036int set_extent_buffer_uptodate(struct extent_io_tree *tree,
3037 struct extent_buffer *eb)
3038{
3039 unsigned long i;
3040 struct page *page;
3041 unsigned long num_pages;
3042
3043 num_pages = num_extent_pages(eb->start, eb->len);
3044
3045 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3046 GFP_NOFS);
3047 for (i = 0; i < num_pages; i++) {
3048 page = extent_buffer_page(eb, i);
3049 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
3050 ((i == num_pages - 1) &&
3051 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
3052 check_page_uptodate(tree, page);
3053 continue;
3054 }
3055 SetPageUptodate(page);
3056 }
3057 return 0;
3058}
3059EXPORT_SYMBOL(set_extent_buffer_uptodate);
3060
ce9adaa5
CM		 3061int extent_range_uptodate(struct extent_io_tree *tree,
3062 u64 start, u64 end)
3063{
3064 struct page *page;
3065 int ret;
3066 int pg_uptodate = 1;
3067 int uptodate;
3068 unsigned long index;
3069
3070 ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1);
3071 if (ret)
3072 return 1;
3073 while(start <= end) {
3074 index = start >> PAGE_CACHE_SHIFT;
3075 page = find_get_page(tree->mapping, index);
3076 uptodate = PageUptodate(page);
3077 page_cache_release(page);
3078 if (!uptodate) {
3079 pg_uptodate = 0;
3080 break;
3081 }
3082 start += PAGE_CACHE_SIZE;
3083 }
3084 return pg_uptodate;
3085}
3086
d1310b2e 3087int extent_buffer_uptodate(struct extent_io_tree *tree,
ce9adaa5 3088 struct extent_buffer *eb)
d1310b2e 3089{
728131d8 3090 int ret = 0;
ce9adaa5
CM		 3091 unsigned long num_pages;
3092 unsigned long i;
728131d8
CM		 3093 struct page *page;
3094 int pg_uptodate = 1;
3095
d1310b2e 3096 if (eb->flags & EXTENT_UPTODATE)
4235298e 3097 return 1;
728131d8 3098
4235298e 3099 ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
d1310b2e 3100 EXTENT_UPTODATE, 1);
4235298e
CM		 3101 if (ret)
3102 return ret;
728131d8
CM		 3103
3104 num_pages = num_extent_pages(eb->start, eb->len);
3105 for (i = 0; i < num_pages; i++) {
3106 page = extent_buffer_page(eb, i);
3107 if (!PageUptodate(page)) {
3108 pg_uptodate = 0;
3109 break;
3110 }
3111 }
4235298e 3112 return pg_uptodate;
d1310b2e
CM		 3113}
3114EXPORT_SYMBOL(extent_buffer_uptodate);
3115
3116int read_extent_buffer_pages(struct extent_io_tree *tree,
3117 struct extent_buffer *eb,
a86c12c7 3118 u64 start, int wait,
f188591e 3119 get_extent_t *get_extent, int mirror_num)
d1310b2e
CM		 3120{
3121 unsigned long i;
3122 unsigned long start_i;
3123 struct page *page;
3124 int err;
3125 int ret = 0;
ce9adaa5
CM		 3126 int locked_pages = 0;
3127 int all_uptodate = 1;
3128 int inc_all_pages = 0;
d1310b2e 3129 unsigned long num_pages;
a86c12c7
CM		 3130 struct bio *bio = NULL;
3131
d1310b2e
CM		 3132 if (eb->flags & EXTENT_UPTODATE)
3133 return 0;
3134
ce9adaa5 3135 if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
d1310b2e
CM		 3136 EXTENT_UPTODATE, 1)) {
3137 return 0;
3138 }
3139
3140 if (start) {
3141 WARN_ON(start < eb->start);
3142 start_i = (start >> PAGE_CACHE_SHIFT) -
3143 (eb->start >> PAGE_CACHE_SHIFT);
3144 } else {
3145 start_i = 0;
3146 }
3147
3148 num_pages = num_extent_pages(eb->start, eb->len);
3149 for (i = start_i; i < num_pages; i++) {
3150 page = extent_buffer_page(eb, i);
d1310b2e 3151 if (!wait) {
ce9adaa5
CM		 3152 if (TestSetPageLocked(page))
3153 goto unlock_exit;
d1310b2e
CM		 3154 } else {
3155 lock_page(page);
3156 }
ce9adaa5 3157 locked_pages++;
d1310b2e 3158 if (!PageUptodate(page)) {
ce9adaa5
CM		 3159 all_uptodate = 0;
3160 }
3161 }
3162 if (all_uptodate) {
3163 if (start_i == 0)
3164 eb->flags |= EXTENT_UPTODATE;
3165 goto unlock_exit;
3166 }
3167
3168 for (i = start_i; i < num_pages; i++) {
3169 page = extent_buffer_page(eb, i);
3170 if (inc_all_pages)
3171 page_cache_get(page);
3172 if (!PageUptodate(page)) {
3173 if (start_i == 0)
3174 inc_all_pages = 1;
f188591e 3175 ClearPageError(page);
a86c12c7 3176 err = __extent_read_full_page(tree, page,
f188591e
CM		 3177 get_extent, &bio,
3178 mirror_num);
d1310b2e
CM		 3179 if (err) {
3180 ret = err;
3181 }
3182 } else {
3183 unlock_page(page);
3184 }
3185 }
3186
a86c12c7 3187 if (bio)
f188591e 3188 submit_one_bio(READ, bio, mirror_num);
a86c12c7 3189
d1310b2e
CM		 3190 if (ret || !wait) {
3191 return ret;
3192 }
d1310b2e
CM		 3193 for (i = start_i; i < num_pages; i++) {
3194 page = extent_buffer_page(eb, i);
3195 wait_on_page_locked(page);
3196 if (!PageUptodate(page)) {
3197 ret = -EIO;
3198 }
3199 }
3200 if (!ret)
3201 eb->flags |= EXTENT_UPTODATE;
3202 return ret;
ce9adaa5
CM		 3203
3204unlock_exit:
3205 i = start_i;
3206 while(locked_pages > 0) {
3207 page = extent_buffer_page(eb, i);
3208 i++;
3209 unlock_page(page);
3210 locked_pages--;
3211 }
3212 return ret;
d1310b2e
CM		 3213}
3214EXPORT_SYMBOL(read_extent_buffer_pages);
3215
3216void read_extent_buffer(struct extent_buffer *eb, void *dstv,
3217 unsigned long start,
3218 unsigned long len)
3219{
3220 size_t cur;
3221 size_t offset;
3222 struct page *page;
3223 char *kaddr;
3224 char *dst = (char *)dstv;
3225 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3226 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
d1310b2e
CM		 3227
3228 WARN_ON(start > eb->len);
3229 WARN_ON(start + len > eb->start + eb->len);
3230
3231 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3232
3233 while(len > 0) {
3234 page = extent_buffer_page(eb, i);
d1310b2e
CM		 3235
3236 cur = min(len, (PAGE_CACHE_SIZE - offset));
3237 kaddr = kmap_atomic(page, KM_USER1);
3238 memcpy(dst, kaddr + offset, cur);
3239 kunmap_atomic(kaddr, KM_USER1);
3240
3241 dst += cur;
3242 len -= cur;
3243 offset = 0;
3244 i++;
3245 }
3246}
3247EXPORT_SYMBOL(read_extent_buffer);
3248
3249int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
3250 unsigned long min_len, char **token, char **map,
3251 unsigned long *map_start,
3252 unsigned long *map_len, int km)
3253{
3254 size_t offset = start & (PAGE_CACHE_SIZE - 1);
3255 char *kaddr;
3256 struct page *p;
3257 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3258 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3259 unsigned long end_i = (start_offset + start + min_len - 1) >>
3260 PAGE_CACHE_SHIFT;
3261
3262 if (i != end_i)
3263 return -EINVAL;
3264
3265 if (i == 0) {
3266 offset = start_offset;
3267 *map_start = 0;
3268 } else {
3269 offset = 0;
3270 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
3271 }
3272 if (start + min_len > eb->len) {
3273printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len);
3274 WARN_ON(1);
3275 }
3276
3277 p = extent_buffer_page(eb, i);
d1310b2e
CM		 3278 kaddr = kmap_atomic(p, km);
3279 *token = kaddr;
3280 *map = kaddr + offset;
3281 *map_len = PAGE_CACHE_SIZE - offset;
3282 return 0;
3283}
3284EXPORT_SYMBOL(map_private_extent_buffer);
3285
3286int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
3287 unsigned long min_len,
3288 char **token, char **map,
3289 unsigned long *map_start,
3290 unsigned long *map_len, int km)
3291{
3292 int err;
3293 int save = 0;
3294 if (eb->map_token) {
3295 unmap_extent_buffer(eb, eb->map_token, km);
3296 eb->map_token = NULL;
3297 save = 1;
3298 }
3299 err = map_private_extent_buffer(eb, start, min_len, token, map,
3300 map_start, map_len, km);
3301 if (!err && save) {
3302 eb->map_token = *token;
3303 eb->kaddr = *map;
3304 eb->map_start = *map_start;
3305 eb->map_len = *map_len;
3306 }
3307 return err;
3308}
3309EXPORT_SYMBOL(map_extent_buffer);
3310
3311void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
3312{
3313 kunmap_atomic(token, km);
3314}
3315EXPORT_SYMBOL(unmap_extent_buffer);
3316
3317int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
3318 unsigned long start,
3319 unsigned long len)
3320{
3321 size_t cur;
3322 size_t offset;
3323 struct page *page;
3324 char *kaddr;
3325 char *ptr = (char *)ptrv;
3326 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3327 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3328 int ret = 0;
3329
3330 WARN_ON(start > eb->len);
3331 WARN_ON(start + len > eb->start + eb->len);
3332
3333 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3334
3335 while(len > 0) {
3336 page = extent_buffer_page(eb, i);
d1310b2e
CM		 3337
3338 cur = min(len, (PAGE_CACHE_SIZE - offset));
3339
3340 kaddr = kmap_atomic(page, KM_USER0);
3341 ret = memcmp(ptr, kaddr + offset, cur);
3342 kunmap_atomic(kaddr, KM_USER0);
3343 if (ret)
3344 break;
3345
3346 ptr += cur;
3347 len -= cur;
3348 offset = 0;
3349 i++;
3350 }
3351 return ret;
3352}
3353EXPORT_SYMBOL(memcmp_extent_buffer);
3354
3355void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
3356 unsigned long start, unsigned long len)
3357{
3358 size_t cur;
3359 size_t offset;
3360 struct page *page;
3361 char *kaddr;
3362 char *src = (char *)srcv;
3363 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3364 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3365
3366 WARN_ON(start > eb->len);
3367 WARN_ON(start + len > eb->start + eb->len);
3368
3369 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3370
3371 while(len > 0) {
3372 page = extent_buffer_page(eb, i);
3373 WARN_ON(!PageUptodate(page));
3374
3375 cur = min(len, PAGE_CACHE_SIZE - offset);
3376 kaddr = kmap_atomic(page, KM_USER1);
3377 memcpy(kaddr + offset, src, cur);
3378 kunmap_atomic(kaddr, KM_USER1);
3379
3380 src += cur;
3381 len -= cur;
3382 offset = 0;
3383 i++;
3384 }
3385}
3386EXPORT_SYMBOL(write_extent_buffer);
3387
3388void memset_extent_buffer(struct extent_buffer *eb, char c,
3389 unsigned long start, unsigned long len)
3390{
3391 size_t cur;
3392 size_t offset;
3393 struct page *page;
3394 char *kaddr;
3395 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3396 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3397
3398 WARN_ON(start > eb->len);
3399 WARN_ON(start + len > eb->start + eb->len);
3400
3401 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3402
3403 while(len > 0) {
3404 page = extent_buffer_page(eb, i);
3405 WARN_ON(!PageUptodate(page));
3406
3407 cur = min(len, PAGE_CACHE_SIZE - offset);
3408 kaddr = kmap_atomic(page, KM_USER0);
3409 memset(kaddr + offset, c, cur);
3410 kunmap_atomic(kaddr, KM_USER0);
3411
3412 len -= cur;
3413 offset = 0;
3414 i++;
3415 }
3416}
3417EXPORT_SYMBOL(memset_extent_buffer);
3418
3419void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
3420 unsigned long dst_offset, unsigned long src_offset,
3421 unsigned long len)
3422{
3423 u64 dst_len = dst->len;
3424 size_t cur;
3425 size_t offset;
3426 struct page *page;
3427 char *kaddr;
3428 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3429 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3430
3431 WARN_ON(src->len != dst_len);
3432
3433 offset = (start_offset + dst_offset) &
3434 ((unsigned long)PAGE_CACHE_SIZE - 1);
3435
3436 while(len > 0) {
3437 page = extent_buffer_page(dst, i);
3438 WARN_ON(!PageUptodate(page));
3439
3440 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
3441
3442 kaddr = kmap_atomic(page, KM_USER0);
3443 read_extent_buffer(src, kaddr + offset, src_offset, cur);
3444 kunmap_atomic(kaddr, KM_USER0);
3445
3446 src_offset += cur;
3447 len -= cur;
3448 offset = 0;
3449 i++;
3450 }
3451}
3452EXPORT_SYMBOL(copy_extent_buffer);
3453
3454static void move_pages(struct page *dst_page, struct page *src_page,
3455 unsigned long dst_off, unsigned long src_off,
3456 unsigned long len)
3457{
3458 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3459 if (dst_page == src_page) {
3460 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
3461 } else {
3462 char *src_kaddr = kmap_atomic(src_page, KM_USER1);
3463 char *p = dst_kaddr + dst_off + len;
3464 char *s = src_kaddr + src_off + len;
3465
3466 while (len--)
3467 *--p = *--s;
3468
3469 kunmap_atomic(src_kaddr, KM_USER1);
3470 }
3471 kunmap_atomic(dst_kaddr, KM_USER0);
3472}
3473
3474static void copy_pages(struct page *dst_page, struct page *src_page,
3475 unsigned long dst_off, unsigned long src_off,
3476 unsigned long len)
3477{
3478 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3479 char *src_kaddr;
3480
3481 if (dst_page != src_page)
3482 src_kaddr = kmap_atomic(src_page, KM_USER1);
3483 else
3484 src_kaddr = dst_kaddr;
3485
3486 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
3487 kunmap_atomic(dst_kaddr, KM_USER0);
3488 if (dst_page != src_page)
3489 kunmap_atomic(src_kaddr, KM_USER1);
3490}
3491
3492void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3493 unsigned long src_offset, unsigned long len)
3494{
3495 size_t cur;
3496 size_t dst_off_in_page;
3497 size_t src_off_in_page;
3498 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3499 unsigned long dst_i;
3500 unsigned long src_i;
3501
3502 if (src_offset + len > dst->len) {
3503 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
3504 src_offset, len, dst->len);
3505 BUG_ON(1);
3506 }
3507 if (dst_offset + len > dst->len) {
3508 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
3509 dst_offset, len, dst->len);
3510 BUG_ON(1);
3511 }
3512
3513 while(len > 0) {
3514 dst_off_in_page = (start_offset + dst_offset) &
3515 ((unsigned long)PAGE_CACHE_SIZE - 1);
3516 src_off_in_page = (start_offset + src_offset) &
3517 ((unsigned long)PAGE_CACHE_SIZE - 1);
3518
3519 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3520 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
3521
3522 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
3523 src_off_in_page));
3524 cur = min_t(unsigned long, cur,
3525 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
3526
3527 copy_pages(extent_buffer_page(dst, dst_i),
3528 extent_buffer_page(dst, src_i),
3529 dst_off_in_page, src_off_in_page, cur);
3530
3531 src_offset += cur;
3532 dst_offset += cur;
3533 len -= cur;
3534 }
3535}
3536EXPORT_SYMBOL(memcpy_extent_buffer);
3537
3538void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3539 unsigned long src_offset, unsigned long len)
3540{
3541 size_t cur;
3542 size_t dst_off_in_page;
3543 size_t src_off_in_page;
3544 unsigned long dst_end = dst_offset + len - 1;
3545 unsigned long src_end = src_offset + len - 1;
3546 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3547 unsigned long dst_i;
3548 unsigned long src_i;
3549
3550 if (src_offset + len > dst->len) {
3551 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
3552 src_offset, len, dst->len);
3553 BUG_ON(1);
3554 }
3555 if (dst_offset + len > dst->len) {
3556 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
3557 dst_offset, len, dst->len);
3558 BUG_ON(1);
3559 }
3560 if (dst_offset < src_offset) {
3561 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
3562 return;
3563 }
3564 while(len > 0) {
3565 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
3566 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
3567
3568 dst_off_in_page = (start_offset + dst_end) &
3569 ((unsigned long)PAGE_CACHE_SIZE - 1);
3570 src_off_in_page = (start_offset + src_end) &
3571 ((unsigned long)PAGE_CACHE_SIZE - 1);
3572
3573 cur = min_t(unsigned long, len, src_off_in_page + 1);
3574 cur = min(cur, dst_off_in_page + 1);
3575 move_pages(extent_buffer_page(dst, dst_i),
3576 extent_buffer_page(dst, src_i),
3577 dst_off_in_page - cur + 1,
3578 src_off_in_page - cur + 1, cur);
3579
3580 dst_end -= cur;
3581 src_end -= cur;
3582 len -= cur;
3583 }
3584}
3585EXPORT_SYMBOL(memmove_extent_buffer);
Linux 6.x block layer and io_uring tree(s)