projects / linux-2.6-block.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Btrfs: Pass down the expected generation number when reading tree blocks
[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
796int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
797 int bits, gfp_t mask)
798{
799 return set_extent_bit(tree, start, end, bits, 0, NULL,
800 mask);
801}
802EXPORT_SYMBOL(set_extent_bits);
803
804int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
805 int bits, gfp_t mask)
806{
807 return clear_extent_bit(tree, start, end, bits, 0, 0, mask);
808}
809EXPORT_SYMBOL(clear_extent_bits);
810
811int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
812 gfp_t mask)
813{
814 return set_extent_bit(tree, start, end,
815 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL,
816 mask);
817}
818EXPORT_SYMBOL(set_extent_delalloc);
819
820int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
821 gfp_t mask)
822{
823 return clear_extent_bit(tree, start, end,
824 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask);
825}
826EXPORT_SYMBOL(clear_extent_dirty);
827
828int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
829 gfp_t mask)
830{
831 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
832 mask);
833}
834EXPORT_SYMBOL(set_extent_new);
835
836int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
837 gfp_t mask)
838{
839 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask);
840}
841EXPORT_SYMBOL(clear_extent_new);
842
843int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
844 gfp_t mask)
845{
846 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
847 mask);
848}
849EXPORT_SYMBOL(set_extent_uptodate);
850
851int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
852 gfp_t mask)
853{
854 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask);
855}
856EXPORT_SYMBOL(clear_extent_uptodate);
857
858int set_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
859 gfp_t mask)
860{
861 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK,
862 0, NULL, mask);
863}
864EXPORT_SYMBOL(set_extent_writeback);
865
866int clear_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
867 gfp_t mask)
868{
869 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask);
870}
871EXPORT_SYMBOL(clear_extent_writeback);
872
873int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
874{
875 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
876}
877EXPORT_SYMBOL(wait_on_extent_writeback);
878
d1310b2e
CM		 879int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
880{
881 int err;
882 u64 failed_start;
883 while (1) {
884 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
885 &failed_start, mask);
886 if (err == -EEXIST && (mask & __GFP_WAIT)) {
887 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
888 start = failed_start;
889 } else {
890 break;
891 }
892 WARN_ON(start > end);
893 }
894 return err;
895}
896EXPORT_SYMBOL(lock_extent);
897
898int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
899 gfp_t mask)
900{
901 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask);
902}
903EXPORT_SYMBOL(unlock_extent);
904
905/*
906 * helper function to set pages and extents in the tree dirty
907 */
908int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
909{
910 unsigned long index = start >> PAGE_CACHE_SHIFT;
911 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
912 struct page *page;
913
914 while (index <= end_index) {
915 page = find_get_page(tree->mapping, index);
916 BUG_ON(!page);
917 __set_page_dirty_nobuffers(page);
918 page_cache_release(page);
919 index++;
920 }
921 set_extent_dirty(tree, start, end, GFP_NOFS);
922 return 0;
923}
924EXPORT_SYMBOL(set_range_dirty);
925
926/*
927 * helper function to set both pages and extents in the tree writeback
928 */
929int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
930{
931 unsigned long index = start >> PAGE_CACHE_SHIFT;
932 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
933 struct page *page;
934
935 while (index <= end_index) {
936 page = find_get_page(tree->mapping, index);
937 BUG_ON(!page);
938 set_page_writeback(page);
939 page_cache_release(page);
940 index++;
941 }
942 set_extent_writeback(tree, start, end, GFP_NOFS);
943 return 0;
944}
945EXPORT_SYMBOL(set_range_writeback);
946
947int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
948 u64 *start_ret, u64 *end_ret, int bits)
949{
950 struct rb_node *node;
951 struct extent_state *state;
952 int ret = 1;
953
70dec807 954 spin_lock_irq(&tree->lock);
d1310b2e
CM		 955 /*
956 * this search will find all the extents that end after
957 * our range starts.
958 */
80ea96b1 959 node = tree_search(tree, start);
2b114d1d 960 if (!node) {
d1310b2e
CM		 961 goto out;
962 }
963
964 while(1) {
965 state = rb_entry(node, struct extent_state, rb_node);
966 if (state->end >= start && (state->state & bits)) {
967 *start_ret = state->start;
968 *end_ret = state->end;
969 ret = 0;
970 break;
971 }
972 node = rb_next(node);
973 if (!node)
974 break;
975 }
976out:
70dec807 977 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 978 return ret;
979}
980EXPORT_SYMBOL(find_first_extent_bit);
981
d7fc640e
CM		 982struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
983 u64 start, int bits)
984{
985 struct rb_node *node;
986 struct extent_state *state;
987
988 /*
989 * this search will find all the extents that end after
990 * our range starts.
991 */
992 node = tree_search(tree, start);
2b114d1d 993 if (!node) {
d7fc640e
CM		 994 goto out;
995 }
996
997 while(1) {
998 state = rb_entry(node, struct extent_state, rb_node);
999 if (state->end >= start && (state->state & bits)) {
1000 return state;
1001 }
1002 node = rb_next(node);
1003 if (!node)
1004 break;
1005 }
1006out:
1007 return NULL;
1008}
1009EXPORT_SYMBOL(find_first_extent_bit_state);
1010
d1310b2e
CM		 1011u64 find_lock_delalloc_range(struct extent_io_tree *tree,
1012 u64 *start, u64 *end, u64 max_bytes)
1013{
1014 struct rb_node *node;
1015 struct extent_state *state;
1016 u64 cur_start = *start;
1017 u64 found = 0;
1018 u64 total_bytes = 0;
1019
70dec807 1020 spin_lock_irq(&tree->lock);
d1310b2e
CM		 1021 /*
1022 * this search will find all the extents that end after
1023 * our range starts.
1024 */
1025search_again:
80ea96b1 1026 node = tree_search(tree, cur_start);
2b114d1d 1027 if (!node) {
3b951516
CM		 1028 if (!found)
1029 *end = (u64)-1;
d1310b2e
CM		 1030 goto out;
1031 }
1032
1033 while(1) {
1034 state = rb_entry(node, struct extent_state, rb_node);
1035 if (found && state->start != cur_start) {
1036 goto out;
1037 }
1038 if (!(state->state & EXTENT_DELALLOC)) {
1039 if (!found)
1040 *end = state->end;
1041 goto out;
1042 }
1043 if (!found) {
1044 struct extent_state *prev_state;
1045 struct rb_node *prev_node = node;
1046 while(1) {
1047 prev_node = rb_prev(prev_node);
1048 if (!prev_node)
1049 break;
1050 prev_state = rb_entry(prev_node,
1051 struct extent_state,
1052 rb_node);
1053 if (!(prev_state->state & EXTENT_DELALLOC))
1054 break;
1055 state = prev_state;
1056 node = prev_node;
1057 }
1058 }
1059 if (state->state & EXTENT_LOCKED) {
1060 DEFINE_WAIT(wait);
1061 atomic_inc(&state->refs);
1062 prepare_to_wait(&state->wq, &wait,
1063 TASK_UNINTERRUPTIBLE);
70dec807 1064 spin_unlock_irq(&tree->lock);
d1310b2e 1065 schedule();
70dec807 1066 spin_lock_irq(&tree->lock);
d1310b2e
CM		 1067 finish_wait(&state->wq, &wait);
1068 free_extent_state(state);
1069 goto search_again;
1070 }
291d673e 1071 set_state_cb(tree, state, EXTENT_LOCKED);
b0c68f8b 1072 state->state |= EXTENT_LOCKED;
d1310b2e
CM		 1073 if (!found)
1074 *start = state->start;
1075 found++;
1076 *end = state->end;
1077 cur_start = state->end + 1;
1078 node = rb_next(node);
1079 if (!node)
1080 break;
1081 total_bytes += state->end - state->start + 1;
1082 if (total_bytes >= max_bytes)
1083 break;
1084 }
1085out:
70dec807 1086 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 1087 return found;
1088}
1089
1090u64 count_range_bits(struct extent_io_tree *tree,
1091 u64 *start, u64 search_end, u64 max_bytes,
1092 unsigned long bits)
1093{
1094 struct rb_node *node;
1095 struct extent_state *state;
1096 u64 cur_start = *start;
1097 u64 total_bytes = 0;
1098 int found = 0;
1099
1100 if (search_end <= cur_start) {
1101 printk("search_end %Lu start %Lu\n", search_end, cur_start);
1102 WARN_ON(1);
1103 return 0;
1104 }
1105
70dec807 1106 spin_lock_irq(&tree->lock);
d1310b2e
CM		 1107 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1108 total_bytes = tree->dirty_bytes;
1109 goto out;
1110 }
1111 /*
1112 * this search will find all the extents that end after
1113 * our range starts.
1114 */
80ea96b1 1115 node = tree_search(tree, cur_start);
2b114d1d 1116 if (!node) {
d1310b2e
CM		 1117 goto out;
1118 }
1119
1120 while(1) {
1121 state = rb_entry(node, struct extent_state, rb_node);
1122 if (state->start > search_end)
1123 break;
1124 if (state->end >= cur_start && (state->state & bits)) {
1125 total_bytes += min(search_end, state->end) + 1 -
1126 max(cur_start, state->start);
1127 if (total_bytes >= max_bytes)
1128 break;
1129 if (!found) {
1130 *start = state->start;
1131 found = 1;
1132 }
1133 }
1134 node = rb_next(node);
1135 if (!node)
1136 break;
1137 }
1138out:
70dec807 1139 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 1140 return total_bytes;
1141}
1142/*
1143 * helper function to lock both pages and extents in the tree.
1144 * pages must be locked first.
1145 */
1146int lock_range(struct extent_io_tree *tree, u64 start, u64 end)
1147{
1148 unsigned long index = start >> PAGE_CACHE_SHIFT;
1149 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1150 struct page *page;
1151 int err;
1152
1153 while (index <= end_index) {
1154 page = grab_cache_page(tree->mapping, index);
1155 if (!page) {
1156 err = -ENOMEM;
1157 goto failed;
1158 }
1159 if (IS_ERR(page)) {
1160 err = PTR_ERR(page);
1161 goto failed;
1162 }
1163 index++;
1164 }
1165 lock_extent(tree, start, end, GFP_NOFS);
1166 return 0;
1167
1168failed:
1169 /*
1170 * we failed above in getting the page at 'index', so we undo here
1171 * up to but not including the page at 'index'
1172 */
1173 end_index = index;
1174 index = start >> PAGE_CACHE_SHIFT;
1175 while (index < end_index) {
1176 page = find_get_page(tree->mapping, index);
1177 unlock_page(page);
1178 page_cache_release(page);
1179 index++;
1180 }
1181 return err;
1182}
1183EXPORT_SYMBOL(lock_range);
1184
1185/*
1186 * helper function to unlock both pages and extents in the tree.
1187 */
1188int unlock_range(struct extent_io_tree *tree, u64 start, u64 end)
1189{
1190 unsigned long index = start >> PAGE_CACHE_SHIFT;
1191 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1192 struct page *page;
1193
1194 while (index <= end_index) {
1195 page = find_get_page(tree->mapping, index);
1196 unlock_page(page);
1197 page_cache_release(page);
1198 index++;
1199 }
1200 unlock_extent(tree, start, end, GFP_NOFS);
1201 return 0;
1202}
1203EXPORT_SYMBOL(unlock_range);
1204
1205int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1206{
1207 struct rb_node *node;
1208 struct extent_state *state;
1209 int ret = 0;
1210
70dec807 1211 spin_lock_irq(&tree->lock);
d1310b2e
CM		 1212 /*
1213 * this search will find all the extents that end after
1214 * our range starts.
1215 */
80ea96b1 1216 node = tree_search(tree, start);
2b114d1d 1217 if (!node) {
d1310b2e
CM		 1218 ret = -ENOENT;
1219 goto out;
1220 }
1221 state = rb_entry(node, struct extent_state, rb_node);
1222 if (state->start != start) {
1223 ret = -ENOENT;
1224 goto out;
1225 }
1226 state->private = private;
1227out:
70dec807 1228 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 1229 return ret;
1230}
1231
1232int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1233{
1234 struct rb_node *node;
1235 struct extent_state *state;
1236 int ret = 0;
1237
70dec807 1238 spin_lock_irq(&tree->lock);
d1310b2e
CM		 1239 /*
1240 * this search will find all the extents that end after
1241 * our range starts.
1242 */
80ea96b1 1243 node = tree_search(tree, start);
2b114d1d 1244 if (!node) {
d1310b2e
CM		 1245 ret = -ENOENT;
1246 goto out;
1247 }
1248 state = rb_entry(node, struct extent_state, rb_node);
1249 if (state->start != start) {
1250 ret = -ENOENT;
1251 goto out;
1252 }
1253 *private = state->private;
1254out:
70dec807 1255 spin_unlock_irq(&tree->lock);
d1310b2e
CM		 1256 return ret;
1257}
1258
1259/*
1260 * searches a range in the state tree for a given mask.
70dec807 1261 * If 'filled' == 1, this returns 1 only if every extent in the tree
d1310b2e
CM		 1262 * has the bits set. Otherwise, 1 is returned if any bit in the
1263 * range is found set.
1264 */
1265int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1266 int bits, int filled)
1267{
1268 struct extent_state *state = NULL;
1269 struct rb_node *node;
1270 int bitset = 0;
1271 unsigned long flags;
1272
70dec807 1273 spin_lock_irqsave(&tree->lock, flags);
80ea96b1 1274 node = tree_search(tree, start);
d1310b2e
CM		 1275 while (node && start <= end) {
1276 state = rb_entry(node, struct extent_state, rb_node);
1277
1278 if (filled && state->start > start) {
1279 bitset = 0;
1280 break;
1281 }
1282
1283 if (state->start > end)
1284 break;
1285
1286 if (state->state & bits) {
1287 bitset = 1;
1288 if (!filled)
1289 break;
1290 } else if (filled) {
1291 bitset = 0;
1292 break;
1293 }
1294 start = state->end + 1;
1295 if (start > end)
1296 break;
1297 node = rb_next(node);
1298 if (!node) {
1299 if (filled)
1300 bitset = 0;
1301 break;
1302 }
1303 }
70dec807 1304 spin_unlock_irqrestore(&tree->lock, flags);
d1310b2e
CM		 1305 return bitset;
1306}
1307EXPORT_SYMBOL(test_range_bit);
1308
1309/*
1310 * helper function to set a given page up to date if all the
1311 * extents in the tree for that page are up to date
1312 */
1313static int check_page_uptodate(struct extent_io_tree *tree,
1314 struct page *page)
1315{
1316 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1317 u64 end = start + PAGE_CACHE_SIZE - 1;
1318 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
1319 SetPageUptodate(page);
1320 return 0;
1321}
1322
1323/*
1324 * helper function to unlock a page if all the extents in the tree
1325 * for that page are unlocked
1326 */
1327static int check_page_locked(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_LOCKED, 0))
1333 unlock_page(page);
1334 return 0;
1335}
1336
1337/*
1338 * helper function to end page writeback if all the extents
1339 * in the tree for that page are done with writeback
1340 */
1341static int check_page_writeback(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_WRITEBACK, 0))
1347 end_page_writeback(page);
1348 return 0;
1349}
1350
1351/* lots and lots of room for performance fixes in the end_bio funcs */
1352
1353/*
1354 * after a writepage IO is done, we need to:
1355 * clear the uptodate bits on error
1356 * clear the writeback bits in the extent tree for this IO
1357 * end_page_writeback if the page has no more pending IO
1358 *
1359 * Scheduling is not allowed, so the extent state tree is expected
1360 * to have one and only one object corresponding to this IO.
1361 */
1362#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1363static void end_bio_extent_writepage(struct bio *bio, int err)
1364#else
1365static int end_bio_extent_writepage(struct bio *bio,
1366 unsigned int bytes_done, int err)
1367#endif
1368{
1369 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1370 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
70dec807
CM		 1371 struct extent_state *state = bio->bi_private;
1372 struct extent_io_tree *tree = state->tree;
1373 struct rb_node *node;
d1310b2e
CM		 1374 u64 start;
1375 u64 end;
70dec807 1376 u64 cur;
d1310b2e 1377 int whole_page;
70dec807 1378 unsigned long flags;
d1310b2e
CM		 1379
1380#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1381 if (bio->bi_size)
1382 return 1;
1383#endif
d1310b2e
CM		 1384 do {
1385 struct page *page = bvec->bv_page;
1386 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1387 bvec->bv_offset;
1388 end = start + bvec->bv_len - 1;
1389
1390 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1391 whole_page = 1;
1392 else
1393 whole_page = 0;
1394
1395 if (--bvec >= bio->bi_io_vec)
1396 prefetchw(&bvec->bv_page->flags);
1397
1398 if (!uptodate) {
1399 clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
1400 ClearPageUptodate(page);
1401 SetPageError(page);
1402 }
70dec807
CM		 1403
1404 if (tree->ops && tree->ops->writepage_end_io_hook) {
1405 tree->ops->writepage_end_io_hook(page, start, end,
1406 state);
1407 }
1408
1409 /*
1410 * bios can get merged in funny ways, and so we need to
1411 * be careful with the state variable. We know the
1412 * state won't be merged with others because it has
1413 * WRITEBACK set, but we can't be sure each biovec is
1414 * sequential in the file. So, if our cached state
1415 * doesn't match the expected end, search the tree
1416 * for the correct one.
1417 */
1418
1419 spin_lock_irqsave(&tree->lock, flags);
1420 if (!state || state->end != end) {
1421 state = NULL;
80ea96b1 1422 node = __etree_search(tree, start, NULL, NULL);
70dec807
CM		 1423 if (node) {
1424 state = rb_entry(node, struct extent_state,
1425 rb_node);
1426 if (state->end != end ||
1427 !(state->state & EXTENT_WRITEBACK))
1428 state = NULL;
1429 }
1430 if (!state) {
1431 spin_unlock_irqrestore(&tree->lock, flags);
1432 clear_extent_writeback(tree, start,
1433 end, GFP_ATOMIC);
1434 goto next_io;
1435 }
1436 }
1437 cur = end;
1438 while(1) {
1439 struct extent_state *clear = state;
1440 cur = state->start;
1441 node = rb_prev(&state->rb_node);
1442 if (node) {
1443 state = rb_entry(node,
1444 struct extent_state,
1445 rb_node);
1446 } else {
1447 state = NULL;
1448 }
1449
1450 clear_state_bit(tree, clear, EXTENT_WRITEBACK,
1451 1, 0);
1452 if (cur == start)
1453 break;
1454 if (cur < start) {
1455 WARN_ON(1);
1456 break;
1457 }
1458 if (!node)
1459 break;
1460 }
1461 /* before releasing the lock, make sure the next state
1462 * variable has the expected bits set and corresponds
1463 * to the correct offsets in the file
1464 */
1465 if (state && (state->end + 1 != start ||
c2e639f0 1466 !(state->state & EXTENT_WRITEBACK))) {
70dec807
CM		 1467 state = NULL;
1468 }
1469 spin_unlock_irqrestore(&tree->lock, flags);
1470next_io:
d1310b2e
CM		 1471
1472 if (whole_page)
1473 end_page_writeback(page);
1474 else
1475 check_page_writeback(tree, page);
d1310b2e 1476 } while (bvec >= bio->bi_io_vec);
d1310b2e
CM		 1477 bio_put(bio);
1478#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1479 return 0;
1480#endif
1481}
1482
1483/*
1484 * after a readpage IO is done, we need to:
1485 * clear the uptodate bits on error
1486 * set the uptodate bits if things worked
1487 * set the page up to date if all extents in the tree are uptodate
1488 * clear the lock bit in the extent tree
1489 * unlock the page if there are no other extents locked for it
1490 *
1491 * Scheduling is not allowed, so the extent state tree is expected
1492 * to have one and only one object corresponding to this IO.
1493 */
1494#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1495static void end_bio_extent_readpage(struct bio *bio, int err)
1496#else
1497static int end_bio_extent_readpage(struct bio *bio,
1498 unsigned int bytes_done, int err)
1499#endif
1500{
1501 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1502 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
70dec807
CM		 1503 struct extent_state *state = bio->bi_private;
1504 struct extent_io_tree *tree = state->tree;
1505 struct rb_node *node;
d1310b2e
CM		 1506 u64 start;
1507 u64 end;
70dec807
CM		 1508 u64 cur;
1509 unsigned long flags;
d1310b2e
CM		 1510 int whole_page;
1511 int ret;
1512
1513#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1514 if (bio->bi_size)
1515 return 1;
1516#endif
1517
1518 do {
1519 struct page *page = bvec->bv_page;
1520 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1521 bvec->bv_offset;
1522 end = start + bvec->bv_len - 1;
1523
1524 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1525 whole_page = 1;
1526 else
1527 whole_page = 0;
1528
1529 if (--bvec >= bio->bi_io_vec)
1530 prefetchw(&bvec->bv_page->flags);
1531
1532 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
70dec807
CM		 1533 ret = tree->ops->readpage_end_io_hook(page, start, end,
1534 state);
d1310b2e
CM		 1535 if (ret)
1536 uptodate = 0;
1537 }
7e38326f
CM		 1538 if (!uptodate && tree->ops &&
1539 tree->ops->readpage_io_failed_hook) {
1540 ret = tree->ops->readpage_io_failed_hook(bio, page,
1541 start, end, state);
1542 if (ret == 0) {
1543 state = NULL;
3b951516
CM		 1544 uptodate =
1545 test_bit(BIO_UPTODATE, &bio->bi_flags);
7e38326f
CM		 1546 continue;
1547 }
1548 }
d1310b2e 1549
70dec807
CM		 1550 spin_lock_irqsave(&tree->lock, flags);
1551 if (!state || state->end != end) {
1552 state = NULL;
80ea96b1 1553 node = __etree_search(tree, start, NULL, NULL);
70dec807
CM		 1554 if (node) {
1555 state = rb_entry(node, struct extent_state,
1556 rb_node);
1557 if (state->end != end ||
1558 !(state->state & EXTENT_LOCKED))
1559 state = NULL;
1560 }
3b951516 1561 if (!state) {
70dec807 1562 spin_unlock_irqrestore(&tree->lock, flags);
3b951516
CM		 1563 if (uptodate)
1564 set_extent_uptodate(tree, start, end,
1565 GFP_ATOMIC);
70dec807
CM		 1566 unlock_extent(tree, start, end, GFP_ATOMIC);
1567 goto next_io;
1568 }
1569 }
d1310b2e 1570
70dec807
CM		 1571 cur = end;
1572 while(1) {
1573 struct extent_state *clear = state;
1574 cur = state->start;
1575 node = rb_prev(&state->rb_node);
1576 if (node) {
1577 state = rb_entry(node,
1578 struct extent_state,
1579 rb_node);
1580 } else {
1581 state = NULL;
1582 }
f188591e
CM		 1583 if (uptodate) {
1584 set_state_cb(tree, clear, EXTENT_UPTODATE);
1585 clear->state |= EXTENT_UPTODATE;
1586 }
70dec807
CM		 1587 clear_state_bit(tree, clear, EXTENT_LOCKED,
1588 1, 0);
1589 if (cur == start)
1590 break;
1591 if (cur < start) {
1592 WARN_ON(1);
1593 break;
1594 }
1595 if (!node)
1596 break;
1597 }
1598 /* before releasing the lock, make sure the next state
1599 * variable has the expected bits set and corresponds
1600 * to the correct offsets in the file
1601 */
1602 if (state && (state->end + 1 != start ||
c2e639f0 1603 !(state->state & EXTENT_LOCKED))) {
70dec807
CM		 1604 state = NULL;
1605 }
1606 spin_unlock_irqrestore(&tree->lock, flags);
1607next_io:
1608 if (whole_page) {
1609 if (uptodate) {
1610 SetPageUptodate(page);
1611 } else {
1612 ClearPageUptodate(page);
1613 SetPageError(page);
1614 }
d1310b2e 1615 unlock_page(page);
70dec807
CM		 1616 } else {
1617 if (uptodate) {
1618 check_page_uptodate(tree, page);
1619 } else {
1620 ClearPageUptodate(page);
1621 SetPageError(page);
1622 }
d1310b2e 1623 check_page_locked(tree, page);
70dec807 1624 }
d1310b2e
CM		 1625 } while (bvec >= bio->bi_io_vec);
1626
1627 bio_put(bio);
1628#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1629 return 0;
1630#endif
1631}
1632
1633/*
1634 * IO done from prepare_write is pretty simple, we just unlock
1635 * the structs in the extent tree when done, and set the uptodate bits
1636 * as appropriate.
1637 */
1638#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1639static void end_bio_extent_preparewrite(struct bio *bio, int err)
1640#else
1641static int end_bio_extent_preparewrite(struct bio *bio,
1642 unsigned int bytes_done, int err)
1643#endif
1644{
1645 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1646 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
70dec807
CM		 1647 struct extent_state *state = bio->bi_private;
1648 struct extent_io_tree *tree = state->tree;
d1310b2e
CM		 1649 u64 start;
1650 u64 end;
1651
1652#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1653 if (bio->bi_size)
1654 return 1;
1655#endif
1656
1657 do {
1658 struct page *page = bvec->bv_page;
1659 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1660 bvec->bv_offset;
1661 end = start + bvec->bv_len - 1;
1662
1663 if (--bvec >= bio->bi_io_vec)
1664 prefetchw(&bvec->bv_page->flags);
1665
1666 if (uptodate) {
1667 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1668 } else {
1669 ClearPageUptodate(page);
1670 SetPageError(page);
1671 }
1672
1673 unlock_extent(tree, start, end, GFP_ATOMIC);
1674
1675 } while (bvec >= bio->bi_io_vec);
1676
1677 bio_put(bio);
1678#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1679 return 0;
1680#endif
1681}
1682
1683static struct bio *
1684extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
1685 gfp_t gfp_flags)
1686{
1687 struct bio *bio;
1688
1689 bio = bio_alloc(gfp_flags, nr_vecs);
1690
1691 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
1692 while (!bio && (nr_vecs /= 2))
1693 bio = bio_alloc(gfp_flags, nr_vecs);
1694 }
1695
1696 if (bio) {
e1c4b745 1697 bio->bi_size = 0;
d1310b2e
CM		 1698 bio->bi_bdev = bdev;
1699 bio->bi_sector = first_sector;
1700 }
1701 return bio;
1702}
1703
f188591e 1704static int submit_one_bio(int rw, struct bio *bio, int mirror_num)
d1310b2e 1705{
d1310b2e 1706 int ret = 0;
70dec807
CM		 1707 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1708 struct page *page = bvec->bv_page;
1709 struct extent_io_tree *tree = bio->bi_private;
1710 struct rb_node *node;
1711 struct extent_state *state;
1712 u64 start;
1713 u64 end;
1714
1715 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1716 end = start + bvec->bv_len - 1;
1717
1718 spin_lock_irq(&tree->lock);
80ea96b1 1719 node = __etree_search(tree, start, NULL, NULL);
70dec807
CM		 1720 BUG_ON(!node);
1721 state = rb_entry(node, struct extent_state, rb_node);
1722 while(state->end < end) {
1723 node = rb_next(node);
1724 state = rb_entry(node, struct extent_state, rb_node);
1725 }
1726 BUG_ON(state->end != end);
1727 spin_unlock_irq(&tree->lock);
1728
1729 bio->bi_private = state;
d1310b2e
CM		 1730
1731 bio_get(bio);
1732
065631f6 1733 if (tree->ops && tree->ops->submit_bio_hook)
f188591e
CM		 1734 tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
1735 mirror_num);
0b86a832
CM		 1736 else
1737 submit_bio(rw, bio);
d1310b2e
CM		 1738 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1739 ret = -EOPNOTSUPP;
1740 bio_put(bio);
1741 return ret;
1742}
1743
1744static int submit_extent_page(int rw, struct extent_io_tree *tree,
1745 struct page *page, sector_t sector,
1746 size_t size, unsigned long offset,
1747 struct block_device *bdev,
1748 struct bio **bio_ret,
1749 unsigned long max_pages,
f188591e
CM		 1750 bio_end_io_t end_io_func,
1751 int mirror_num)
d1310b2e
CM		 1752{
1753 int ret = 0;
1754 struct bio *bio;
1755 int nr;
1756
1757 if (bio_ret && *bio_ret) {
1758 bio = *bio_ret;
1759 if (bio->bi_sector + (bio->bi_size >> 9) != sector ||
239b14b3
CM		 1760 (tree->ops && tree->ops->merge_bio_hook &&
1761 tree->ops->merge_bio_hook(page, offset, size, bio)) ||
d1310b2e 1762 bio_add_page(bio, page, size, offset) < size) {
f188591e 1763 ret = submit_one_bio(rw, bio, mirror_num);
d1310b2e
CM		 1764 bio = NULL;
1765 } else {
1766 return 0;
1767 }
1768 }
961d0232 1769 nr = bio_get_nr_vecs(bdev);
d1310b2e
CM		 1770 bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
1771 if (!bio) {
1772 printk("failed to allocate bio nr %d\n", nr);
1773 }
70dec807
CM		 1774
1775
d1310b2e
CM		 1776 bio_add_page(bio, page, size, offset);
1777 bio->bi_end_io = end_io_func;
1778 bio->bi_private = tree;
70dec807 1779
d1310b2e
CM		 1780 if (bio_ret) {
1781 *bio_ret = bio;
1782 } else {
f188591e 1783 ret = submit_one_bio(rw, bio, mirror_num);
d1310b2e
CM		 1784 }
1785
1786 return ret;
1787}
1788
1789void set_page_extent_mapped(struct page *page)
1790{
1791 if (!PagePrivate(page)) {
1792 SetPagePrivate(page);
1793 WARN_ON(!page->mapping->a_ops->invalidatepage);
1794 set_page_private(page, EXTENT_PAGE_PRIVATE);
1795 page_cache_get(page);
1796 }
1797}
1798
1799void set_page_extent_head(struct page *page, unsigned long len)
1800{
1801 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
1802}
1803
1804/*
1805 * basic readpage implementation. Locked extent state structs are inserted
1806 * into the tree that are removed when the IO is done (by the end_io
1807 * handlers)
1808 */
1809static int __extent_read_full_page(struct extent_io_tree *tree,
1810 struct page *page,
1811 get_extent_t *get_extent,
f188591e 1812 struct bio **bio, int mirror_num)
d1310b2e
CM		 1813{
1814 struct inode *inode = page->mapping->host;
1815 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1816 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1817 u64 end;
1818 u64 cur = start;
1819 u64 extent_offset;
1820 u64 last_byte = i_size_read(inode);
1821 u64 block_start;
1822 u64 cur_end;
1823 sector_t sector;
1824 struct extent_map *em;
1825 struct block_device *bdev;
1826 int ret;
1827 int nr = 0;
1828 size_t page_offset = 0;
1829 size_t iosize;
1830 size_t blocksize = inode->i_sb->s_blocksize;
1831
1832 set_page_extent_mapped(page);
1833
1834 end = page_end;
1835 lock_extent(tree, start, end, GFP_NOFS);
1836
1837 while (cur <= end) {
1838 if (cur >= last_byte) {
1839 char *userpage;
1840 iosize = PAGE_CACHE_SIZE - page_offset;
1841 userpage = kmap_atomic(page, KM_USER0);
1842 memset(userpage + page_offset, 0, iosize);
1843 flush_dcache_page(page);
1844 kunmap_atomic(userpage, KM_USER0);
1845 set_extent_uptodate(tree, cur, cur + iosize - 1,
1846 GFP_NOFS);
1847 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1848 break;
1849 }
1850 em = get_extent(inode, page, page_offset, cur,
1851 end - cur + 1, 0);
1852 if (IS_ERR(em) || !em) {
1853 SetPageError(page);
1854 unlock_extent(tree, cur, end, GFP_NOFS);
1855 break;
1856 }
1857
1858 extent_offset = cur - em->start;
1859 BUG_ON(extent_map_end(em) <= cur);
1860 BUG_ON(end < cur);
1861
1862 iosize = min(extent_map_end(em) - cur, end - cur + 1);
1863 cur_end = min(extent_map_end(em) - 1, end);
1864 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
1865 sector = (em->block_start + extent_offset) >> 9;
1866 bdev = em->bdev;
1867 block_start = em->block_start;
1868 free_extent_map(em);
1869 em = NULL;
1870
1871 /* we've found a hole, just zero and go on */
1872 if (block_start == EXTENT_MAP_HOLE) {
1873 char *userpage;
1874 userpage = kmap_atomic(page, KM_USER0);
1875 memset(userpage + page_offset, 0, iosize);
1876 flush_dcache_page(page);
1877 kunmap_atomic(userpage, KM_USER0);
1878
1879 set_extent_uptodate(tree, cur, cur + iosize - 1,
1880 GFP_NOFS);
1881 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1882 cur = cur + iosize;
1883 page_offset += iosize;
1884 continue;
1885 }
1886 /* the get_extent function already copied into the page */
1887 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
1888 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1889 cur = cur + iosize;
1890 page_offset += iosize;
1891 continue;
1892 }
70dec807
CM		 1893 /* we have an inline extent but it didn't get marked up
1894 * to date. Error out
1895 */
1896 if (block_start == EXTENT_MAP_INLINE) {
1897 SetPageError(page);
1898 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1899 cur = cur + iosize;
1900 page_offset += iosize;
1901 continue;
1902 }
d1310b2e
CM		 1903
1904 ret = 0;
1905 if (tree->ops && tree->ops->readpage_io_hook) {
1906 ret = tree->ops->readpage_io_hook(page, cur,
1907 cur + iosize - 1);
1908 }
1909 if (!ret) {
1910 unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
1911 nr -= page->index;
1912 ret = submit_extent_page(READ, tree, page,
1913 sector, iosize, page_offset,
1914 bdev, bio, nr,
f188591e 1915 end_bio_extent_readpage, mirror_num);
d1310b2e
CM		 1916 }
1917 if (ret)
1918 SetPageError(page);
1919 cur = cur + iosize;
1920 page_offset += iosize;
1921 nr++;
1922 }
1923 if (!nr) {
1924 if (!PageError(page))
1925 SetPageUptodate(page);
1926 unlock_page(page);
1927 }
1928 return 0;
1929}
1930
1931int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
1932 get_extent_t *get_extent)
1933{
1934 struct bio *bio = NULL;
1935 int ret;
1936
f188591e 1937 ret = __extent_read_full_page(tree, page, get_extent, &bio, 0);
d1310b2e 1938 if (bio)
f188591e 1939 submit_one_bio(READ, bio, 0);
d1310b2e
CM		 1940 return ret;
1941}
1942EXPORT_SYMBOL(extent_read_full_page);
1943
1944/*
1945 * the writepage semantics are similar to regular writepage. extent
1946 * records are inserted to lock ranges in the tree, and as dirty areas
1947 * are found, they are marked writeback. Then the lock bits are removed
1948 * and the end_io handler clears the writeback ranges
1949 */
1950static int __extent_writepage(struct page *page, struct writeback_control *wbc,
1951 void *data)
1952{
1953 struct inode *inode = page->mapping->host;
1954 struct extent_page_data *epd = data;
1955 struct extent_io_tree *tree = epd->tree;
1956 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1957 u64 delalloc_start;
1958 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1959 u64 end;
1960 u64 cur = start;
1961 u64 extent_offset;
1962 u64 last_byte = i_size_read(inode);
1963 u64 block_start;
1964 u64 iosize;
1965 sector_t sector;
1966 struct extent_map *em;
1967 struct block_device *bdev;
1968 int ret;
1969 int nr = 0;
1970 size_t page_offset = 0;
1971 size_t blocksize;
1972 loff_t i_size = i_size_read(inode);
1973 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
1974 u64 nr_delalloc;
1975 u64 delalloc_end;
1976
1977 WARN_ON(!PageLocked(page));
1978 if (page->index > end_index) {
1979 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
1980 unlock_page(page);
1981 return 0;
1982 }
1983
1984 if (page->index == end_index) {
1985 char *userpage;
1986
1987 size_t offset = i_size & (PAGE_CACHE_SIZE - 1);
1988
1989 userpage = kmap_atomic(page, KM_USER0);
1990 memset(userpage + offset, 0, PAGE_CACHE_SIZE - offset);
1991 flush_dcache_page(page);
1992 kunmap_atomic(userpage, KM_USER0);
1993 }
1994
1995 set_page_extent_mapped(page);
1996
1997 delalloc_start = start;
1998 delalloc_end = 0;
1999 while(delalloc_end < page_end) {
2000 nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start,
2001 &delalloc_end,
2002 128 * 1024 * 1024);
2003 if (nr_delalloc == 0) {
2004 delalloc_start = delalloc_end + 1;
2005 continue;
2006 }
2007 tree->ops->fill_delalloc(inode, delalloc_start,
2008 delalloc_end);
2009 clear_extent_bit(tree, delalloc_start,
2010 delalloc_end,
2011 EXTENT_LOCKED | EXTENT_DELALLOC,
2012 1, 0, GFP_NOFS);
2013 delalloc_start = delalloc_end + 1;
2014 }
2015 lock_extent(tree, start, page_end, GFP_NOFS);
2016
2017 end = page_end;
2018 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
2019 printk("found delalloc bits after lock_extent\n");
2020 }
2021
2022 if (last_byte <= start) {
2023 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
2024 goto done;
2025 }
2026
2027 set_extent_uptodate(tree, start, page_end, GFP_NOFS);
2028 blocksize = inode->i_sb->s_blocksize;
2029
2030 while (cur <= end) {
2031 if (cur >= last_byte) {
2032 clear_extent_dirty(tree, cur, page_end, GFP_NOFS);
2033 break;
2034 }
2035 em = epd->get_extent(inode, page, page_offset, cur,
2036 end - cur + 1, 1);
2037 if (IS_ERR(em) || !em) {
2038 SetPageError(page);
2039 break;
2040 }
2041
2042 extent_offset = cur - em->start;
2043 BUG_ON(extent_map_end(em) <= cur);
2044 BUG_ON(end < cur);
2045 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2046 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2047 sector = (em->block_start + extent_offset) >> 9;
2048 bdev = em->bdev;
2049 block_start = em->block_start;
2050 free_extent_map(em);
2051 em = NULL;
2052
2053 if (block_start == EXTENT_MAP_HOLE ||
2054 block_start == EXTENT_MAP_INLINE) {
2055 clear_extent_dirty(tree, cur,
2056 cur + iosize - 1, GFP_NOFS);
2057 cur = cur + iosize;
2058 page_offset += iosize;
2059 continue;
2060 }
2061
2062 /* leave this out until we have a page_mkwrite call */
2063 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2064 EXTENT_DIRTY, 0)) {
2065 cur = cur + iosize;
2066 page_offset += iosize;
2067 continue;
2068 }
2069 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
2070 if (tree->ops && tree->ops->writepage_io_hook) {
2071 ret = tree->ops->writepage_io_hook(page, cur,
2072 cur + iosize - 1);
2073 } else {
2074 ret = 0;
2075 }
2076 if (ret)
2077 SetPageError(page);
2078 else {
2079 unsigned long max_nr = end_index + 1;
2080 set_range_writeback(tree, cur, cur + iosize - 1);
2081 if (!PageWriteback(page)) {
2082 printk("warning page %lu not writeback, "
2083 "cur %llu end %llu\n", page->index,
2084 (unsigned long long)cur,
2085 (unsigned long long)end);
2086 }
2087
2088 ret = submit_extent_page(WRITE, tree, page, sector,
2089 iosize, page_offset, bdev,
2090 &epd->bio, max_nr,
f188591e 2091 end_bio_extent_writepage, 0);
d1310b2e
CM		 2092 if (ret)
2093 SetPageError(page);
2094 }
2095 cur = cur + iosize;
2096 page_offset += iosize;
2097 nr++;
2098 }
2099done:
2100 if (nr == 0) {
2101 /* make sure the mapping tag for page dirty gets cleared */
2102 set_page_writeback(page);
2103 end_page_writeback(page);
2104 }
2105 unlock_extent(tree, start, page_end, GFP_NOFS);
2106 unlock_page(page);
2107 return 0;
2108}
2109
5e478dc9 2110#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
d1310b2e
CM		 2111/* Taken directly from 2.6.23 for 2.6.18 back port */
2112typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
2113 void *data);
2114
2115/**
2116 * write_cache_pages - walk the list of dirty pages of the given address space
2117 * and write all of them.
2118 * @mapping: address space structure to write
2119 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2120 * @writepage: function called for each page
2121 * @data: data passed to writepage function
2122 *
2123 * If a page is already under I/O, write_cache_pages() skips it, even
2124 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2125 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2126 * and msync() need to guarantee that all the data which was dirty at the time
2127 * the call was made get new I/O started against them. If wbc->sync_mode is
2128 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2129 * existing IO to complete.
2130 */
2131static int write_cache_pages(struct address_space *mapping,
2132 struct writeback_control *wbc, writepage_t writepage,
2133 void *data)
2134{
2135 struct backing_dev_info *bdi = mapping->backing_dev_info;
2136 int ret = 0;
2137 int done = 0;
2138 struct pagevec pvec;
2139 int nr_pages;
2140 pgoff_t index;
2141 pgoff_t end; /* Inclusive */
2142 int scanned = 0;
2143 int range_whole = 0;
2144
2145 if (wbc->nonblocking && bdi_write_congested(bdi)) {
2146 wbc->encountered_congestion = 1;
2147 return 0;
2148 }
2149
2150 pagevec_init(&pvec, 0);
2151 if (wbc->range_cyclic) {
2152 index = mapping->writeback_index; /* Start from prev offset */
2153 end = -1;
2154 } else {
2155 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2156 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2157 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2158 range_whole = 1;
2159 scanned = 1;
2160 }
2161retry:
2162 while (!done && (index <= end) &&
2163 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
2164 PAGECACHE_TAG_DIRTY,
2165 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
2166 unsigned i;
2167
2168 scanned = 1;
2169 for (i = 0; i < nr_pages; i++) {
2170 struct page *page = pvec.pages[i];
2171
2172 /*
2173 * At this point we hold neither mapping->tree_lock nor
2174 * lock on the page itself: the page may be truncated or
2175 * invalidated (changing page->mapping to NULL), or even
2176 * swizzled back from swapper_space to tmpfs file
2177 * mapping
2178 */
2179 lock_page(page);
2180
2181 if (unlikely(page->mapping != mapping)) {
2182 unlock_page(page);
2183 continue;
2184 }
2185
2186 if (!wbc->range_cyclic && page->index > end) {
2187 done = 1;
2188 unlock_page(page);
2189 continue;
2190 }
2191
2192 if (wbc->sync_mode != WB_SYNC_NONE)
2193 wait_on_page_writeback(page);
2194
2195 if (PageWriteback(page) ||
2196 !clear_page_dirty_for_io(page)) {
2197 unlock_page(page);
2198 continue;
2199 }
2200
2201 ret = (*writepage)(page, wbc, data);
2202
2203 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
2204 unlock_page(page);
2205 ret = 0;
2206 }
2207 if (ret || (--(wbc->nr_to_write) <= 0))
2208 done = 1;
2209 if (wbc->nonblocking && bdi_write_congested(bdi)) {
2210 wbc->encountered_congestion = 1;
2211 done = 1;
2212 }
2213 }
2214 pagevec_release(&pvec);
2215 cond_resched();
2216 }
2217 if (!scanned && !done) {
2218 /*
2219 * We hit the last page and there is more work to be done: wrap
2220 * back to the start of the file
2221 */
2222 scanned = 1;
2223 index = 0;
2224 goto retry;
2225 }
2226 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2227 mapping->writeback_index = index;
2228 return ret;
2229}
2230#endif
2231
2232int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
2233 get_extent_t *get_extent,
2234 struct writeback_control *wbc)
2235{
2236 int ret;
2237 struct address_space *mapping = page->mapping;
2238 struct extent_page_data epd = {
2239 .bio = NULL,
2240 .tree = tree,
2241 .get_extent = get_extent,
2242 };
2243 struct writeback_control wbc_writepages = {
2244 .bdi = wbc->bdi,
2245 .sync_mode = WB_SYNC_NONE,
2246 .older_than_this = NULL,
2247 .nr_to_write = 64,
2248 .range_start = page_offset(page) + PAGE_CACHE_SIZE,
2249 .range_end = (loff_t)-1,
2250 };
2251
2252
2253 ret = __extent_writepage(page, wbc, &epd);
2254
2255 write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd);
2256 if (epd.bio) {
f188591e 2257 submit_one_bio(WRITE, epd.bio, 0);
d1310b2e
CM		 2258 }
2259 return ret;
2260}
2261EXPORT_SYMBOL(extent_write_full_page);
2262
2263
2264int extent_writepages(struct extent_io_tree *tree,
2265 struct address_space *mapping,
2266 get_extent_t *get_extent,
2267 struct writeback_control *wbc)
2268{
2269 int ret = 0;
2270 struct extent_page_data epd = {
2271 .bio = NULL,
2272 .tree = tree,
2273 .get_extent = get_extent,
2274 };
2275
2276 ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd);
2277 if (epd.bio) {
f188591e 2278 submit_one_bio(WRITE, epd.bio, 0);
d1310b2e
CM		 2279 }
2280 return ret;
2281}
2282EXPORT_SYMBOL(extent_writepages);
2283
2284int extent_readpages(struct extent_io_tree *tree,
2285 struct address_space *mapping,
2286 struct list_head *pages, unsigned nr_pages,
2287 get_extent_t get_extent)
2288{
2289 struct bio *bio = NULL;
2290 unsigned page_idx;
2291 struct pagevec pvec;
2292
2293 pagevec_init(&pvec, 0);
2294 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
2295 struct page *page = list_entry(pages->prev, struct page, lru);
2296
2297 prefetchw(&page->flags);
2298 list_del(&page->lru);
2299 /*
2300 * what we want to do here is call add_to_page_cache_lru,
2301 * but that isn't exported, so we reproduce it here
2302 */
2303 if (!add_to_page_cache(page, mapping,
2304 page->index, GFP_KERNEL)) {
2305
2306 /* open coding of lru_cache_add, also not exported */
2307 page_cache_get(page);
2308 if (!pagevec_add(&pvec, page))
2309 __pagevec_lru_add(&pvec);
f188591e
CM		 2310 __extent_read_full_page(tree, page, get_extent,
2311 &bio, 0);
d1310b2e
CM		 2312 }
2313 page_cache_release(page);
2314 }
2315 if (pagevec_count(&pvec))
2316 __pagevec_lru_add(&pvec);
2317 BUG_ON(!list_empty(pages));
2318 if (bio)
f188591e 2319 submit_one_bio(READ, bio, 0);
d1310b2e
CM		 2320 return 0;
2321}
2322EXPORT_SYMBOL(extent_readpages);
2323
2324/*
2325 * basic invalidatepage code, this waits on any locked or writeback
2326 * ranges corresponding to the page, and then deletes any extent state
2327 * records from the tree
2328 */
2329int extent_invalidatepage(struct extent_io_tree *tree,
2330 struct page *page, unsigned long offset)
2331{
2332 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
2333 u64 end = start + PAGE_CACHE_SIZE - 1;
2334 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
2335
2336 start += (offset + blocksize -1) & ~(blocksize - 1);
2337 if (start > end)
2338 return 0;
2339
2340 lock_extent(tree, start, end, GFP_NOFS);
2341 wait_on_extent_writeback(tree, start, end);
2342 clear_extent_bit(tree, start, end,
2343 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
2344 1, 1, GFP_NOFS);
2345 return 0;
2346}
2347EXPORT_SYMBOL(extent_invalidatepage);
2348
2349/*
2350 * simple commit_write call, set_range_dirty is used to mark both
2351 * the pages and the extent records as dirty
2352 */
2353int extent_commit_write(struct extent_io_tree *tree,
2354 struct inode *inode, struct page *page,
2355 unsigned from, unsigned to)
2356{
2357 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
2358
2359 set_page_extent_mapped(page);
2360 set_page_dirty(page);
2361
2362 if (pos > inode->i_size) {
2363 i_size_write(inode, pos);
2364 mark_inode_dirty(inode);
2365 }
2366 return 0;
2367}
2368EXPORT_SYMBOL(extent_commit_write);
2369
2370int extent_prepare_write(struct extent_io_tree *tree,
2371 struct inode *inode, struct page *page,
2372 unsigned from, unsigned to, get_extent_t *get_extent)
2373{
2374 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2375 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
2376 u64 block_start;
2377 u64 orig_block_start;
2378 u64 block_end;
2379 u64 cur_end;
2380 struct extent_map *em;
2381 unsigned blocksize = 1 << inode->i_blkbits;
2382 size_t page_offset = 0;
2383 size_t block_off_start;
2384 size_t block_off_end;
2385 int err = 0;
2386 int iocount = 0;
2387 int ret = 0;
2388 int isnew;
2389
2390 set_page_extent_mapped(page);
2391
2392 block_start = (page_start + from) & ~((u64)blocksize - 1);
2393 block_end = (page_start + to - 1) | (blocksize - 1);
2394 orig_block_start = block_start;
2395
2396 lock_extent(tree, page_start, page_end, GFP_NOFS);
2397 while(block_start <= block_end) {
2398 em = get_extent(inode, page, page_offset, block_start,
2399 block_end - block_start + 1, 1);
2400 if (IS_ERR(em) || !em) {
2401 goto err;
2402 }
2403 cur_end = min(block_end, extent_map_end(em) - 1);
2404 block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
2405 block_off_end = block_off_start + blocksize;
2406 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
2407
2408 if (!PageUptodate(page) && isnew &&
2409 (block_off_end > to || block_off_start < from)) {
2410 void *kaddr;
2411
2412 kaddr = kmap_atomic(page, KM_USER0);
2413 if (block_off_end > to)
2414 memset(kaddr + to, 0, block_off_end - to);
2415 if (block_off_start < from)
2416 memset(kaddr + block_off_start, 0,
2417 from - block_off_start);
2418 flush_dcache_page(page);
2419 kunmap_atomic(kaddr, KM_USER0);
2420 }
2421 if ((em->block_start != EXTENT_MAP_HOLE &&
2422 em->block_start != EXTENT_MAP_INLINE) &&
2423 !isnew && !PageUptodate(page) &&
2424 (block_off_end > to || block_off_start < from) &&
2425 !test_range_bit(tree, block_start, cur_end,
2426 EXTENT_UPTODATE, 1)) {
2427 u64 sector;
2428 u64 extent_offset = block_start - em->start;
2429 size_t iosize;
2430 sector = (em->block_start + extent_offset) >> 9;
2431 iosize = (cur_end - block_start + blocksize) &
2432 ~((u64)blocksize - 1);
2433 /*
2434 * we've already got the extent locked, but we
2435 * need to split the state such that our end_bio
2436 * handler can clear the lock.
2437 */
2438 set_extent_bit(tree, block_start,
2439 block_start + iosize - 1,
2440 EXTENT_LOCKED, 0, NULL, GFP_NOFS);
2441 ret = submit_extent_page(READ, tree, page,
2442 sector, iosize, page_offset, em->bdev,
2443 NULL, 1,
f188591e 2444 end_bio_extent_preparewrite, 0);
d1310b2e
CM		 2445 iocount++;
2446 block_start = block_start + iosize;
2447 } else {
2448 set_extent_uptodate(tree, block_start, cur_end,
2449 GFP_NOFS);
2450 unlock_extent(tree, block_start, cur_end, GFP_NOFS);
2451 block_start = cur_end + 1;
2452 }
2453 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
2454 free_extent_map(em);
2455 }
2456 if (iocount) {
2457 wait_extent_bit(tree, orig_block_start,
2458 block_end, EXTENT_LOCKED);
2459 }
2460 check_page_uptodate(tree, page);
2461err:
2462 /* FIXME, zero out newly allocated blocks on error */
2463 return err;
2464}
2465EXPORT_SYMBOL(extent_prepare_write);
2466
7b13b7b1
CM		 2467/*
2468 * a helper for releasepage, this tests for areas of the page that
2469 * are locked or under IO and drops the related state bits if it is safe
2470 * to drop the page.
2471 */
2472int try_release_extent_state(struct extent_map_tree *map,
2473 struct extent_io_tree *tree, struct page *page,
2474 gfp_t mask)
2475{
2476 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2477 u64 end = start + PAGE_CACHE_SIZE - 1;
2478 int ret = 1;
2479
2480 if (test_range_bit(tree, start, end, EXTENT_IOBITS, 0))
2481 ret = 0;
2482 else {
2483 if ((mask & GFP_NOFS) == GFP_NOFS)
2484 mask = GFP_NOFS;
2485 clear_extent_bit(tree, start, end, EXTENT_UPTODATE,
2486 1, 1, mask);
2487 }
2488 return ret;
2489}
2490EXPORT_SYMBOL(try_release_extent_state);
2491
d1310b2e
CM		 2492/*
2493 * a helper for releasepage. As long as there are no locked extents
2494 * in the range corresponding to the page, both state records and extent
2495 * map records are removed
2496 */
2497int try_release_extent_mapping(struct extent_map_tree *map,
70dec807
CM		 2498 struct extent_io_tree *tree, struct page *page,
2499 gfp_t mask)
d1310b2e
CM		 2500{
2501 struct extent_map *em;
2502 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2503 u64 end = start + PAGE_CACHE_SIZE - 1;
7b13b7b1 2504
70dec807
CM		 2505 if ((mask & __GFP_WAIT) &&
2506 page->mapping->host->i_size > 16 * 1024 * 1024) {
39b5637f 2507 u64 len;
70dec807 2508 while (start <= end) {
39b5637f 2509 len = end - start + 1;
70dec807 2510 spin_lock(&map->lock);
39b5637f 2511 em = lookup_extent_mapping(map, start, len);
70dec807
CM		 2512 if (!em || IS_ERR(em)) {
2513 spin_unlock(&map->lock);
2514 break;
2515 }
2516 if (em->start != start) {
2517 spin_unlock(&map->lock);
2518 free_extent_map(em);
2519 break;
2520 }
2521 if (!test_range_bit(tree, em->start,
2522 extent_map_end(em) - 1,
2523 EXTENT_LOCKED, 0)) {
2524 remove_extent_mapping(map, em);
2525 /* once for the rb tree */
2526 free_extent_map(em);
2527 }
2528 start = extent_map_end(em);
d1310b2e 2529 spin_unlock(&map->lock);
70dec807
CM		 2530
2531 /* once for us */
d1310b2e
CM		 2532 free_extent_map(em);
2533 }
d1310b2e 2534 }
7b13b7b1 2535 return try_release_extent_state(map, tree, page, mask);
d1310b2e
CM		 2536}
2537EXPORT_SYMBOL(try_release_extent_mapping);
2538
2539sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
2540 get_extent_t *get_extent)
2541{
2542 struct inode *inode = mapping->host;
2543 u64 start = iblock << inode->i_blkbits;
2544 sector_t sector = 0;
2545 struct extent_map *em;
2546
2547 em = get_extent(inode, NULL, 0, start, (1 << inode->i_blkbits), 0);
2548 if (!em || IS_ERR(em))
2549 return 0;
2550
2551 if (em->block_start == EXTENT_MAP_INLINE ||
2552 em->block_start == EXTENT_MAP_HOLE)
2553 goto out;
2554
2555 sector = (em->block_start + start - em->start) >> inode->i_blkbits;
d1310b2e
CM		 2556out:
2557 free_extent_map(em);
2558 return sector;
2559}
2560
2561static int add_lru(struct extent_io_tree *tree, struct extent_buffer *eb)
2562{
2563 if (list_empty(&eb->lru)) {
2564 extent_buffer_get(eb);
2565 list_add(&eb->lru, &tree->buffer_lru);
2566 tree->lru_size++;
2567 if (tree->lru_size >= BUFFER_LRU_MAX) {
2568 struct extent_buffer *rm;
2569 rm = list_entry(tree->buffer_lru.prev,
2570 struct extent_buffer, lru);
2571 tree->lru_size--;
2572 list_del_init(&rm->lru);
2573 free_extent_buffer(rm);
2574 }
2575 } else
2576 list_move(&eb->lru, &tree->buffer_lru);
2577 return 0;
2578}
2579static struct extent_buffer *find_lru(struct extent_io_tree *tree,
2580 u64 start, unsigned long len)
2581{
2582 struct list_head *lru = &tree->buffer_lru;
2583 struct list_head *cur = lru->next;
2584 struct extent_buffer *eb;
2585
2586 if (list_empty(lru))
2587 return NULL;
2588
2589 do {
2590 eb = list_entry(cur, struct extent_buffer, lru);
2591 if (eb->start == start && eb->len == len) {
2592 extent_buffer_get(eb);
2593 return eb;
2594 }
2595 cur = cur->next;
2596 } while (cur != lru);
2597 return NULL;
2598}
2599
2600static inline unsigned long num_extent_pages(u64 start, u64 len)
2601{
2602 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
2603 (start >> PAGE_CACHE_SHIFT);
2604}
2605
2606static inline struct page *extent_buffer_page(struct extent_buffer *eb,
2607 unsigned long i)
2608{
2609 struct page *p;
2610 struct address_space *mapping;
2611
2612 if (i == 0)
2613 return eb->first_page;
2614 i += eb->start >> PAGE_CACHE_SHIFT;
2615 mapping = eb->first_page->mapping;
2616 read_lock_irq(&mapping->tree_lock);
2617 p = radix_tree_lookup(&mapping->page_tree, i);
2618 read_unlock_irq(&mapping->tree_lock);
2619 return p;
2620}
2621
ce9adaa5
CM		 2622int release_extent_buffer_tail_pages(struct extent_buffer *eb)
2623{
2624 unsigned long num_pages = num_extent_pages(eb->start, eb->len);
2625 struct page *page;
2626 unsigned long i;
2627
2628 if (num_pages == 1)
2629 return 0;
2630 for (i = 1; i < num_pages; i++) {
2631 page = extent_buffer_page(eb, i);
2632 page_cache_release(page);
2633 }
2634 return 0;
2635}
2636
2637
728131d8
CM		 2638int invalidate_extent_lru(struct extent_io_tree *tree, u64 start,
2639 unsigned long len)
2640{
2641 struct list_head *lru = &tree->buffer_lru;
2642 struct list_head *cur = lru->next;
2643 struct extent_buffer *eb;
2644 int found = 0;
2645
2646 spin_lock(&tree->lru_lock);
2647 if (list_empty(lru))
2648 goto out;
2649
2650 do {
2651 eb = list_entry(cur, struct extent_buffer, lru);
2652 if (eb->start <= start && eb->start + eb->len > start) {
2653 eb->flags &= ~EXTENT_UPTODATE;
2654 }
728131d8
CM		 2655 cur = cur->next;
2656 } while (cur != lru);
2657out:
2658 spin_unlock(&tree->lru_lock);
2659 return found;
2660}
2661
d1310b2e
CM		 2662static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
2663 u64 start,
2664 unsigned long len,
2665 gfp_t mask)
2666{
2667 struct extent_buffer *eb = NULL;
2d2ae547 2668 unsigned long flags;
d1310b2e
CM		 2669
2670 spin_lock(&tree->lru_lock);
2671 eb = find_lru(tree, start, len);
2672 spin_unlock(&tree->lru_lock);
2673 if (eb) {
2674 return eb;
2675 }
2676
2677 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
2678 INIT_LIST_HEAD(&eb->lru);
2679 eb->start = start;
2680 eb->len = len;
2d2ae547
CM		 2681 spin_lock_irqsave(&leak_lock, flags);
2682 list_add(&eb->leak_list, &buffers);
2683 spin_unlock_irqrestore(&leak_lock, flags);
d1310b2e
CM		 2684 atomic_set(&eb->refs, 1);
2685
2686 return eb;
2687}
2688
2689static void __free_extent_buffer(struct extent_buffer *eb)
2690{
2d2ae547
CM		 2691 unsigned long flags;
2692 spin_lock_irqsave(&leak_lock, flags);
2693 list_del(&eb->leak_list);
2694 spin_unlock_irqrestore(&leak_lock, flags);
d1310b2e
CM		 2695 kmem_cache_free(extent_buffer_cache, eb);
2696}
2697
2698struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
2699 u64 start, unsigned long len,
2700 struct page *page0,
2701 gfp_t mask)
2702{
2703 unsigned long num_pages = num_extent_pages(start, len);
2704 unsigned long i;
2705 unsigned long index = start >> PAGE_CACHE_SHIFT;
2706 struct extent_buffer *eb;
2707 struct page *p;
2708 struct address_space *mapping = tree->mapping;
2709 int uptodate = 1;
2710
2711 eb = __alloc_extent_buffer(tree, start, len, mask);
2b114d1d 2712 if (!eb)
d1310b2e
CM		 2713 return NULL;
2714
2715 if (eb->flags & EXTENT_BUFFER_FILLED)
2716 goto lru_add;
2717
2718 if (page0) {
2719 eb->first_page = page0;
2720 i = 1;
2721 index++;
2722 page_cache_get(page0);
2723 mark_page_accessed(page0);
2724 set_page_extent_mapped(page0);
d1310b2e 2725 set_page_extent_head(page0, len);
f188591e 2726 uptodate = PageUptodate(page0);
d1310b2e
CM		 2727 } else {
2728 i = 0;
2729 }
2730 for (; i < num_pages; i++, index++) {
2731 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
2732 if (!p) {
2733 WARN_ON(1);
2734 goto fail;
2735 }
2736 set_page_extent_mapped(p);
2737 mark_page_accessed(p);
2738 if (i == 0) {
2739 eb->first_page = p;
2740 set_page_extent_head(p, len);
2741 } else {
2742 set_page_private(p, EXTENT_PAGE_PRIVATE);
2743 }
2744 if (!PageUptodate(p))
2745 uptodate = 0;
2746 unlock_page(p);
2747 }
2748 if (uptodate)
2749 eb->flags |= EXTENT_UPTODATE;
2750 eb->flags |= EXTENT_BUFFER_FILLED;
2751
2752lru_add:
2753 spin_lock(&tree->lru_lock);
2754 add_lru(tree, eb);
2755 spin_unlock(&tree->lru_lock);
2756 return eb;
2757
2758fail:
2759 spin_lock(&tree->lru_lock);
2760 list_del_init(&eb->lru);
2761 spin_unlock(&tree->lru_lock);
2762 if (!atomic_dec_and_test(&eb->refs))
2763 return NULL;
2764 for (index = 1; index < i; index++) {
2765 page_cache_release(extent_buffer_page(eb, index));
2766 }
2767 if (i > 0)
2768 page_cache_release(extent_buffer_page(eb, 0));
2769 __free_extent_buffer(eb);
2770 return NULL;
2771}
2772EXPORT_SYMBOL(alloc_extent_buffer);
2773
2774struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
2775 u64 start, unsigned long len,
2776 gfp_t mask)
2777{
2778 unsigned long num_pages = num_extent_pages(start, len);
2779 unsigned long i;
2780 unsigned long index = start >> PAGE_CACHE_SHIFT;
2781 struct extent_buffer *eb;
2782 struct page *p;
2783 struct address_space *mapping = tree->mapping;
2784 int uptodate = 1;
2785
2786 eb = __alloc_extent_buffer(tree, start, len, mask);
2b114d1d 2787 if (!eb)
d1310b2e
CM		 2788 return NULL;
2789
2790 if (eb->flags & EXTENT_BUFFER_FILLED)
2791 goto lru_add;
2792
2793 for (i = 0; i < num_pages; i++, index++) {
2794 p = find_lock_page(mapping, index);
2795 if (!p) {
2796 goto fail;
2797 }
2798 set_page_extent_mapped(p);
2799 mark_page_accessed(p);
2800
2801 if (i == 0) {
2802 eb->first_page = p;
2803 set_page_extent_head(p, len);
2804 } else {
2805 set_page_private(p, EXTENT_PAGE_PRIVATE);
2806 }
2807
2808 if (!PageUptodate(p))
2809 uptodate = 0;
2810 unlock_page(p);
2811 }
2812 if (uptodate)
2813 eb->flags |= EXTENT_UPTODATE;
2814 eb->flags |= EXTENT_BUFFER_FILLED;
2815
2816lru_add:
2817 spin_lock(&tree->lru_lock);
2818 add_lru(tree, eb);
2819 spin_unlock(&tree->lru_lock);
2820 return eb;
2821fail:
2822 spin_lock(&tree->lru_lock);
2823 list_del_init(&eb->lru);
2824 spin_unlock(&tree->lru_lock);
2825 if (!atomic_dec_and_test(&eb->refs))
2826 return NULL;
2827 for (index = 1; index < i; index++) {
2828 page_cache_release(extent_buffer_page(eb, index));
2829 }
2830 if (i > 0)
2831 page_cache_release(extent_buffer_page(eb, 0));
2832 __free_extent_buffer(eb);
2833 return NULL;
2834}
2835EXPORT_SYMBOL(find_extent_buffer);
2836
2837void free_extent_buffer(struct extent_buffer *eb)
2838{
2839 unsigned long i;
2840 unsigned long num_pages;
2841
2842 if (!eb)
2843 return;
2844
2845 if (!atomic_dec_and_test(&eb->refs))
2846 return;
2847
2848 WARN_ON(!list_empty(&eb->lru));
2849 num_pages = num_extent_pages(eb->start, eb->len);
2850
2851 for (i = 1; i < num_pages; i++) {
2852 page_cache_release(extent_buffer_page(eb, i));
2853 }
2854 page_cache_release(extent_buffer_page(eb, 0));
2855 __free_extent_buffer(eb);
2856}
2857EXPORT_SYMBOL(free_extent_buffer);
2858
2859int clear_extent_buffer_dirty(struct extent_io_tree *tree,
2860 struct extent_buffer *eb)
2861{
2862 int set;
2863 unsigned long i;
2864 unsigned long num_pages;
2865 struct page *page;
2866
2867 u64 start = eb->start;
2868 u64 end = start + eb->len - 1;
2869
2870 set = clear_extent_dirty(tree, start, end, GFP_NOFS);
2871 num_pages = num_extent_pages(eb->start, eb->len);
2872
2873 for (i = 0; i < num_pages; i++) {
2874 page = extent_buffer_page(eb, i);
2875 lock_page(page);
2876 if (i == 0)
2877 set_page_extent_head(page, eb->len);
2878 else
2879 set_page_private(page, EXTENT_PAGE_PRIVATE);
2880
2881 /*
2882 * if we're on the last page or the first page and the
2883 * block isn't aligned on a page boundary, do extra checks
2884 * to make sure we don't clean page that is partially dirty
2885 */
2886 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
2887 ((i == num_pages - 1) &&
2888 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
2889 start = (u64)page->index << PAGE_CACHE_SHIFT;
2890 end = start + PAGE_CACHE_SIZE - 1;
2891 if (test_range_bit(tree, start, end,
2892 EXTENT_DIRTY, 0)) {
2893 unlock_page(page);
2894 continue;
2895 }
2896 }
2897 clear_page_dirty_for_io(page);
70dec807 2898 read_lock_irq(&page->mapping->tree_lock);
d1310b2e
CM		 2899 if (!PageDirty(page)) {
2900 radix_tree_tag_clear(&page->mapping->page_tree,
2901 page_index(page),
2902 PAGECACHE_TAG_DIRTY);
2903 }
70dec807 2904 read_unlock_irq(&page->mapping->tree_lock);
d1310b2e
CM		 2905 unlock_page(page);
2906 }
2907 return 0;
2908}
2909EXPORT_SYMBOL(clear_extent_buffer_dirty);
2910
2911int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
2912 struct extent_buffer *eb)
2913{
2914 return wait_on_extent_writeback(tree, eb->start,
2915 eb->start + eb->len - 1);
2916}
2917EXPORT_SYMBOL(wait_on_extent_buffer_writeback);
2918
2919int set_extent_buffer_dirty(struct extent_io_tree *tree,
2920 struct extent_buffer *eb)
2921{
2922 unsigned long i;
2923 unsigned long num_pages;
2924
2925 num_pages = num_extent_pages(eb->start, eb->len);
2926 for (i = 0; i < num_pages; i++) {
2927 struct page *page = extent_buffer_page(eb, i);
2928 /* writepage may need to do something special for the
2929 * first page, we have to make sure page->private is
2930 * properly set. releasepage may drop page->private
2931 * on us if the page isn't already dirty.
2932 */
2933 if (i == 0) {
2934 lock_page(page);
2935 set_page_extent_head(page, eb->len);
2936 } else if (PagePrivate(page) &&
2937 page->private != EXTENT_PAGE_PRIVATE) {
2938 lock_page(page);
2939 set_page_extent_mapped(page);
2940 unlock_page(page);
2941 }
2942 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
2943 if (i == 0)
2944 unlock_page(page);
2945 }
2946 return set_extent_dirty(tree, eb->start,
2947 eb->start + eb->len - 1, GFP_NOFS);
2948}
2949EXPORT_SYMBOL(set_extent_buffer_dirty);
2950
2951int set_extent_buffer_uptodate(struct extent_io_tree *tree,
2952 struct extent_buffer *eb)
2953{
2954 unsigned long i;
2955 struct page *page;
2956 unsigned long num_pages;
2957
2958 num_pages = num_extent_pages(eb->start, eb->len);
2959
2960 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
2961 GFP_NOFS);
2962 for (i = 0; i < num_pages; i++) {
2963 page = extent_buffer_page(eb, i);
2964 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
2965 ((i == num_pages - 1) &&
2966 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
2967 check_page_uptodate(tree, page);
2968 continue;
2969 }
2970 SetPageUptodate(page);
2971 }
2972 return 0;
2973}
2974EXPORT_SYMBOL(set_extent_buffer_uptodate);
2975
ce9adaa5
CM		 2976int extent_range_uptodate(struct extent_io_tree *tree,
2977 u64 start, u64 end)
2978{
2979 struct page *page;
2980 int ret;
2981 int pg_uptodate = 1;
2982 int uptodate;
2983 unsigned long index;
2984
2985 ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1);
2986 if (ret)
2987 return 1;
2988 while(start <= end) {
2989 index = start >> PAGE_CACHE_SHIFT;
2990 page = find_get_page(tree->mapping, index);
2991 uptodate = PageUptodate(page);
2992 page_cache_release(page);
2993 if (!uptodate) {
2994 pg_uptodate = 0;
2995 break;
2996 }
2997 start += PAGE_CACHE_SIZE;
2998 }
2999 return pg_uptodate;
3000}
3001
d1310b2e 3002int extent_buffer_uptodate(struct extent_io_tree *tree,
ce9adaa5 3003 struct extent_buffer *eb)
d1310b2e 3004{
728131d8 3005 int ret = 0;
ce9adaa5
CM		 3006 unsigned long num_pages;
3007 unsigned long i;
728131d8
CM		 3008 struct page *page;
3009 int pg_uptodate = 1;
3010
d1310b2e 3011 if (eb->flags & EXTENT_UPTODATE)
4235298e 3012 return 1;
728131d8 3013
4235298e 3014 ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
d1310b2e 3015 EXTENT_UPTODATE, 1);
4235298e
CM		 3016 if (ret)
3017 return ret;
728131d8
CM		 3018
3019 num_pages = num_extent_pages(eb->start, eb->len);
3020 for (i = 0; i < num_pages; i++) {
3021 page = extent_buffer_page(eb, i);
3022 if (!PageUptodate(page)) {
3023 pg_uptodate = 0;
3024 break;
3025 }
3026 }
4235298e 3027 return pg_uptodate;
d1310b2e
CM		 3028}
3029EXPORT_SYMBOL(extent_buffer_uptodate);
3030
3031int read_extent_buffer_pages(struct extent_io_tree *tree,
3032 struct extent_buffer *eb,
a86c12c7 3033 u64 start, int wait,
f188591e 3034 get_extent_t *get_extent, int mirror_num)
d1310b2e
CM		 3035{
3036 unsigned long i;
3037 unsigned long start_i;
3038 struct page *page;
3039 int err;
3040 int ret = 0;
ce9adaa5
CM		 3041 int locked_pages = 0;
3042 int all_uptodate = 1;
3043 int inc_all_pages = 0;
d1310b2e 3044 unsigned long num_pages;
a86c12c7
CM		 3045 struct bio *bio = NULL;
3046
d1310b2e
CM		 3047 if (eb->flags & EXTENT_UPTODATE)
3048 return 0;
3049
ce9adaa5 3050 if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
d1310b2e
CM		 3051 EXTENT_UPTODATE, 1)) {
3052 return 0;
3053 }
3054
3055 if (start) {
3056 WARN_ON(start < eb->start);
3057 start_i = (start >> PAGE_CACHE_SHIFT) -
3058 (eb->start >> PAGE_CACHE_SHIFT);
3059 } else {
3060 start_i = 0;
3061 }
3062
3063 num_pages = num_extent_pages(eb->start, eb->len);
3064 for (i = start_i; i < num_pages; i++) {
3065 page = extent_buffer_page(eb, i);
d1310b2e 3066 if (!wait) {
ce9adaa5
CM		 3067 if (TestSetPageLocked(page))
3068 goto unlock_exit;
d1310b2e
CM		 3069 } else {
3070 lock_page(page);
3071 }
ce9adaa5 3072 locked_pages++;
d1310b2e 3073 if (!PageUptodate(page)) {
ce9adaa5
CM		 3074 all_uptodate = 0;
3075 }
3076 }
3077 if (all_uptodate) {
3078 if (start_i == 0)
3079 eb->flags |= EXTENT_UPTODATE;
3080 goto unlock_exit;
3081 }
3082
3083 for (i = start_i; i < num_pages; i++) {
3084 page = extent_buffer_page(eb, i);
3085 if (inc_all_pages)
3086 page_cache_get(page);
3087 if (!PageUptodate(page)) {
3088 if (start_i == 0)
3089 inc_all_pages = 1;
f188591e 3090 ClearPageError(page);
a86c12c7 3091 err = __extent_read_full_page(tree, page,
f188591e
CM		 3092 get_extent, &bio,
3093 mirror_num);
d1310b2e
CM		 3094 if (err) {
3095 ret = err;
3096 }
3097 } else {
3098 unlock_page(page);
3099 }
3100 }
3101
a86c12c7 3102 if (bio)
f188591e 3103 submit_one_bio(READ, bio, mirror_num);
a86c12c7 3104
d1310b2e
CM		 3105 if (ret || !wait) {
3106 return ret;
3107 }
d1310b2e
CM		 3108 for (i = start_i; i < num_pages; i++) {
3109 page = extent_buffer_page(eb, i);
3110 wait_on_page_locked(page);
3111 if (!PageUptodate(page)) {
3112 ret = -EIO;
3113 }
3114 }
3115 if (!ret)
3116 eb->flags |= EXTENT_UPTODATE;
3117 return ret;
ce9adaa5
CM		 3118
3119unlock_exit:
3120 i = start_i;
3121 while(locked_pages > 0) {
3122 page = extent_buffer_page(eb, i);
3123 i++;
3124 unlock_page(page);
3125 locked_pages--;
3126 }
3127 return ret;
d1310b2e
CM		 3128}
3129EXPORT_SYMBOL(read_extent_buffer_pages);
3130
3131void read_extent_buffer(struct extent_buffer *eb, void *dstv,
3132 unsigned long start,
3133 unsigned long len)
3134{
3135 size_t cur;
3136 size_t offset;
3137 struct page *page;
3138 char *kaddr;
3139 char *dst = (char *)dstv;
3140 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3141 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
d1310b2e
CM		 3142
3143 WARN_ON(start > eb->len);
3144 WARN_ON(start + len > eb->start + eb->len);
3145
3146 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3147
3148 while(len > 0) {
3149 page = extent_buffer_page(eb, i);
d1310b2e
CM		 3150
3151 cur = min(len, (PAGE_CACHE_SIZE - offset));
3152 kaddr = kmap_atomic(page, KM_USER1);
3153 memcpy(dst, kaddr + offset, cur);
3154 kunmap_atomic(kaddr, KM_USER1);
3155
3156 dst += cur;
3157 len -= cur;
3158 offset = 0;
3159 i++;
3160 }
3161}
3162EXPORT_SYMBOL(read_extent_buffer);
3163
3164int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
3165 unsigned long min_len, char **token, char **map,
3166 unsigned long *map_start,
3167 unsigned long *map_len, int km)
3168{
3169 size_t offset = start & (PAGE_CACHE_SIZE - 1);
3170 char *kaddr;
3171 struct page *p;
3172 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3173 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3174 unsigned long end_i = (start_offset + start + min_len - 1) >>
3175 PAGE_CACHE_SHIFT;
3176
3177 if (i != end_i)
3178 return -EINVAL;
3179
3180 if (i == 0) {
3181 offset = start_offset;
3182 *map_start = 0;
3183 } else {
3184 offset = 0;
3185 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
3186 }
3187 if (start + min_len > eb->len) {
3188printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len);
3189 WARN_ON(1);
3190 }
3191
3192 p = extent_buffer_page(eb, i);
d1310b2e
CM		 3193 kaddr = kmap_atomic(p, km);
3194 *token = kaddr;
3195 *map = kaddr + offset;
3196 *map_len = PAGE_CACHE_SIZE - offset;
3197 return 0;
3198}
3199EXPORT_SYMBOL(map_private_extent_buffer);
3200
3201int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
3202 unsigned long min_len,
3203 char **token, char **map,
3204 unsigned long *map_start,
3205 unsigned long *map_len, int km)
3206{
3207 int err;
3208 int save = 0;
3209 if (eb->map_token) {
3210 unmap_extent_buffer(eb, eb->map_token, km);
3211 eb->map_token = NULL;
3212 save = 1;
3213 }
3214 err = map_private_extent_buffer(eb, start, min_len, token, map,
3215 map_start, map_len, km);
3216 if (!err && save) {
3217 eb->map_token = *token;
3218 eb->kaddr = *map;
3219 eb->map_start = *map_start;
3220 eb->map_len = *map_len;
3221 }
3222 return err;
3223}
3224EXPORT_SYMBOL(map_extent_buffer);
3225
3226void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
3227{
3228 kunmap_atomic(token, km);
3229}
3230EXPORT_SYMBOL(unmap_extent_buffer);
3231
3232int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
3233 unsigned long start,
3234 unsigned long len)
3235{
3236 size_t cur;
3237 size_t offset;
3238 struct page *page;
3239 char *kaddr;
3240 char *ptr = (char *)ptrv;
3241 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3242 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3243 int ret = 0;
3244
3245 WARN_ON(start > eb->len);
3246 WARN_ON(start + len > eb->start + eb->len);
3247
3248 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3249
3250 while(len > 0) {
3251 page = extent_buffer_page(eb, i);
d1310b2e
CM		 3252
3253 cur = min(len, (PAGE_CACHE_SIZE - offset));
3254
3255 kaddr = kmap_atomic(page, KM_USER0);
3256 ret = memcmp(ptr, kaddr + offset, cur);
3257 kunmap_atomic(kaddr, KM_USER0);
3258 if (ret)
3259 break;
3260
3261 ptr += cur;
3262 len -= cur;
3263 offset = 0;
3264 i++;
3265 }
3266 return ret;
3267}
3268EXPORT_SYMBOL(memcmp_extent_buffer);
3269
3270void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
3271 unsigned long start, unsigned long len)
3272{
3273 size_t cur;
3274 size_t offset;
3275 struct page *page;
3276 char *kaddr;
3277 char *src = (char *)srcv;
3278 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3279 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3280
3281 WARN_ON(start > eb->len);
3282 WARN_ON(start + len > eb->start + eb->len);
3283
3284 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3285
3286 while(len > 0) {
3287 page = extent_buffer_page(eb, i);
3288 WARN_ON(!PageUptodate(page));
3289
3290 cur = min(len, PAGE_CACHE_SIZE - offset);
3291 kaddr = kmap_atomic(page, KM_USER1);
3292 memcpy(kaddr + offset, src, cur);
3293 kunmap_atomic(kaddr, KM_USER1);
3294
3295 src += cur;
3296 len -= cur;
3297 offset = 0;
3298 i++;
3299 }
3300}
3301EXPORT_SYMBOL(write_extent_buffer);
3302
3303void memset_extent_buffer(struct extent_buffer *eb, char c,
3304 unsigned long start, unsigned long len)
3305{
3306 size_t cur;
3307 size_t offset;
3308 struct page *page;
3309 char *kaddr;
3310 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3311 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3312
3313 WARN_ON(start > eb->len);
3314 WARN_ON(start + len > eb->start + eb->len);
3315
3316 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3317
3318 while(len > 0) {
3319 page = extent_buffer_page(eb, i);
3320 WARN_ON(!PageUptodate(page));
3321
3322 cur = min(len, PAGE_CACHE_SIZE - offset);
3323 kaddr = kmap_atomic(page, KM_USER0);
3324 memset(kaddr + offset, c, cur);
3325 kunmap_atomic(kaddr, KM_USER0);
3326
3327 len -= cur;
3328 offset = 0;
3329 i++;
3330 }
3331}
3332EXPORT_SYMBOL(memset_extent_buffer);
3333
3334void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
3335 unsigned long dst_offset, unsigned long src_offset,
3336 unsigned long len)
3337{
3338 u64 dst_len = dst->len;
3339 size_t cur;
3340 size_t offset;
3341 struct page *page;
3342 char *kaddr;
3343 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3344 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3345
3346 WARN_ON(src->len != dst_len);
3347
3348 offset = (start_offset + dst_offset) &
3349 ((unsigned long)PAGE_CACHE_SIZE - 1);
3350
3351 while(len > 0) {
3352 page = extent_buffer_page(dst, i);
3353 WARN_ON(!PageUptodate(page));
3354
3355 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
3356
3357 kaddr = kmap_atomic(page, KM_USER0);
3358 read_extent_buffer(src, kaddr + offset, src_offset, cur);
3359 kunmap_atomic(kaddr, KM_USER0);
3360
3361 src_offset += cur;
3362 len -= cur;
3363 offset = 0;
3364 i++;
3365 }
3366}
3367EXPORT_SYMBOL(copy_extent_buffer);
3368
3369static void move_pages(struct page *dst_page, struct page *src_page,
3370 unsigned long dst_off, unsigned long src_off,
3371 unsigned long len)
3372{
3373 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3374 if (dst_page == src_page) {
3375 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
3376 } else {
3377 char *src_kaddr = kmap_atomic(src_page, KM_USER1);
3378 char *p = dst_kaddr + dst_off + len;
3379 char *s = src_kaddr + src_off + len;
3380
3381 while (len--)
3382 *--p = *--s;
3383
3384 kunmap_atomic(src_kaddr, KM_USER1);
3385 }
3386 kunmap_atomic(dst_kaddr, KM_USER0);
3387}
3388
3389static void copy_pages(struct page *dst_page, struct page *src_page,
3390 unsigned long dst_off, unsigned long src_off,
3391 unsigned long len)
3392{
3393 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3394 char *src_kaddr;
3395
3396 if (dst_page != src_page)
3397 src_kaddr = kmap_atomic(src_page, KM_USER1);
3398 else
3399 src_kaddr = dst_kaddr;
3400
3401 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
3402 kunmap_atomic(dst_kaddr, KM_USER0);
3403 if (dst_page != src_page)
3404 kunmap_atomic(src_kaddr, KM_USER1);
3405}
3406
3407void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3408 unsigned long src_offset, unsigned long len)
3409{
3410 size_t cur;
3411 size_t dst_off_in_page;
3412 size_t src_off_in_page;
3413 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3414 unsigned long dst_i;
3415 unsigned long src_i;
3416
3417 if (src_offset + len > dst->len) {
3418 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
3419 src_offset, len, dst->len);
3420 BUG_ON(1);
3421 }
3422 if (dst_offset + len > dst->len) {
3423 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
3424 dst_offset, len, dst->len);
3425 BUG_ON(1);
3426 }
3427
3428 while(len > 0) {
3429 dst_off_in_page = (start_offset + dst_offset) &
3430 ((unsigned long)PAGE_CACHE_SIZE - 1);
3431 src_off_in_page = (start_offset + src_offset) &
3432 ((unsigned long)PAGE_CACHE_SIZE - 1);
3433
3434 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3435 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
3436
3437 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
3438 src_off_in_page));
3439 cur = min_t(unsigned long, cur,
3440 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
3441
3442 copy_pages(extent_buffer_page(dst, dst_i),
3443 extent_buffer_page(dst, src_i),
3444 dst_off_in_page, src_off_in_page, cur);
3445
3446 src_offset += cur;
3447 dst_offset += cur;
3448 len -= cur;
3449 }
3450}
3451EXPORT_SYMBOL(memcpy_extent_buffer);
3452
3453void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3454 unsigned long src_offset, unsigned long len)
3455{
3456 size_t cur;
3457 size_t dst_off_in_page;
3458 size_t src_off_in_page;
3459 unsigned long dst_end = dst_offset + len - 1;
3460 unsigned long src_end = src_offset + len - 1;
3461 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3462 unsigned long dst_i;
3463 unsigned long src_i;
3464
3465 if (src_offset + len > dst->len) {
3466 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
3467 src_offset, len, dst->len);
3468 BUG_ON(1);
3469 }
3470 if (dst_offset + len > dst->len) {
3471 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
3472 dst_offset, len, dst->len);
3473 BUG_ON(1);
3474 }
3475 if (dst_offset < src_offset) {
3476 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
3477 return;
3478 }
3479 while(len > 0) {
3480 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
3481 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
3482
3483 dst_off_in_page = (start_offset + dst_end) &
3484 ((unsigned long)PAGE_CACHE_SIZE - 1);
3485 src_off_in_page = (start_offset + src_end) &
3486 ((unsigned long)PAGE_CACHE_SIZE - 1);
3487
3488 cur = min_t(unsigned long, len, src_off_in_page + 1);
3489 cur = min(cur, dst_off_in_page + 1);
3490 move_pages(extent_buffer_page(dst, dst_i),
3491 extent_buffer_page(dst, src_i),
3492 dst_off_in_page - cur + 1,
3493 src_off_in_page - cur + 1, cur);
3494
3495 dst_end -= cur;
3496 src_end -= cur;
3497 len -= cur;
3498 }
3499}
3500EXPORT_SYMBOL(memmove_extent_buffer);
Linux 6.x block layer and io_uring tree(s)