1 #include <linux/bitops.h>
2 #include <linux/slab.h>
6 #include <linux/pagemap.h>
7 #include <linux/page-flags.h>
8 #include <linux/module.h>
9 #include <linux/spinlock.h>
10 #include <linux/blkdev.h>
11 #include "extent_map.h"
13 /* temporary define until extent_map moves out of btrfs */
14 struct kmem_cache
*btrfs_cache_create(const char *name
, size_t size
,
15 unsigned long extra_flags
,
16 void (*ctor
)(void *, struct kmem_cache
*,
19 static struct kmem_cache
*extent_map_cache
;
20 static struct kmem_cache
*extent_state_cache
;
21 static struct kmem_cache
*extent_buffer_cache
;
23 static LIST_HEAD(extent_buffers
);
24 static LIST_HEAD(buffers
);
25 static LIST_HEAD(states
);
27 static spinlock_t extent_buffers_lock
;
28 static spinlock_t state_lock
= SPIN_LOCK_UNLOCKED
;
29 static int nr_extent_buffers
;
30 #define MAX_EXTENT_BUFFER_CACHE 128
36 struct rb_node rb_node
;
39 void __init
extent_map_init(void)
41 extent_map_cache
= btrfs_cache_create("extent_map",
42 sizeof(struct extent_map
), 0,
44 extent_state_cache
= btrfs_cache_create("extent_state",
45 sizeof(struct extent_state
), 0,
47 extent_buffer_cache
= btrfs_cache_create("extent_buffers",
48 sizeof(struct extent_buffer
), 0,
50 spin_lock_init(&extent_buffers_lock
);
53 void __exit
extent_map_exit(void)
55 struct extent_buffer
*eb
;
56 struct extent_state
*state
;
58 while (!list_empty(&extent_buffers
)) {
59 eb
= list_entry(extent_buffers
.next
,
60 struct extent_buffer
, list
);
62 kmem_cache_free(extent_buffer_cache
, eb
);
64 while (!list_empty(&states
)) {
65 state
= list_entry(states
.next
, struct extent_state
, list
);
66 printk("state leak: start %Lu end %Lu state %lu in tree %d refs %d\n", state
->start
, state
->end
, state
->state
, state
->in_tree
, atomic_read(&state
->refs
));
67 list_del(&state
->list
);
68 kmem_cache_free(extent_state_cache
, state
);
71 while (!list_empty(&buffers
)) {
72 eb
= list_entry(buffers
.next
,
73 struct extent_buffer
, leak_list
);
74 printk("buffer leak start %Lu len %lu return %lX\n", eb
->start
, eb
->len
, eb
->alloc_addr
);
75 list_del(&eb
->leak_list
);
76 kmem_cache_free(extent_buffer_cache
, eb
);
81 kmem_cache_destroy(extent_map_cache
);
82 if (extent_state_cache
)
83 kmem_cache_destroy(extent_state_cache
);
84 if (extent_buffer_cache
)
85 kmem_cache_destroy(extent_buffer_cache
);
88 void extent_map_tree_init(struct extent_map_tree
*tree
,
89 struct address_space
*mapping
, gfp_t mask
)
91 tree
->map
.rb_node
= NULL
;
92 tree
->state
.rb_node
= NULL
;
94 rwlock_init(&tree
->lock
);
95 tree
->mapping
= mapping
;
97 EXPORT_SYMBOL(extent_map_tree_init
);
99 struct extent_map
*alloc_extent_map(gfp_t mask
)
101 struct extent_map
*em
;
102 em
= kmem_cache_alloc(extent_map_cache
, mask
);
103 if (!em
|| IS_ERR(em
))
106 atomic_set(&em
->refs
, 1);
109 EXPORT_SYMBOL(alloc_extent_map
);
111 void free_extent_map(struct extent_map
*em
)
115 if (atomic_dec_and_test(&em
->refs
)) {
116 WARN_ON(em
->in_tree
);
117 kmem_cache_free(extent_map_cache
, em
);
120 EXPORT_SYMBOL(free_extent_map
);
123 struct extent_state
*alloc_extent_state(gfp_t mask
)
125 struct extent_state
*state
;
128 state
= kmem_cache_alloc(extent_state_cache
, mask
);
129 if (!state
|| IS_ERR(state
))
135 spin_lock_irqsave(&state_lock
, flags
);
136 list_add(&state
->list
, &states
);
137 spin_unlock_irqrestore(&state_lock
, flags
);
139 atomic_set(&state
->refs
, 1);
140 init_waitqueue_head(&state
->wq
);
143 EXPORT_SYMBOL(alloc_extent_state
);
145 void free_extent_state(struct extent_state
*state
)
150 if (atomic_dec_and_test(&state
->refs
)) {
151 WARN_ON(state
->in_tree
);
152 spin_lock_irqsave(&state_lock
, flags
);
153 list_del(&state
->list
);
154 spin_unlock_irqrestore(&state_lock
, flags
);
155 kmem_cache_free(extent_state_cache
, state
);
158 EXPORT_SYMBOL(free_extent_state
);
160 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
161 struct rb_node
*node
)
163 struct rb_node
** p
= &root
->rb_node
;
164 struct rb_node
* parent
= NULL
;
165 struct tree_entry
*entry
;
169 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
171 if (offset
< entry
->start
)
173 else if (offset
> entry
->end
)
179 entry
= rb_entry(node
, struct tree_entry
, rb_node
);
181 rb_link_node(node
, parent
, p
);
182 rb_insert_color(node
, root
);
186 static struct rb_node
*__tree_search(struct rb_root
*root
, u64 offset
,
187 struct rb_node
**prev_ret
)
189 struct rb_node
* n
= root
->rb_node
;
190 struct rb_node
*prev
= NULL
;
191 struct tree_entry
*entry
;
192 struct tree_entry
*prev_entry
= NULL
;
195 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
199 if (offset
< entry
->start
)
201 else if (offset
> entry
->end
)
208 while(prev
&& offset
> prev_entry
->end
) {
209 prev
= rb_next(prev
);
210 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
216 static inline struct rb_node
*tree_search(struct rb_root
*root
, u64 offset
)
218 struct rb_node
*prev
;
220 ret
= __tree_search(root
, offset
, &prev
);
226 static int tree_delete(struct rb_root
*root
, u64 offset
)
228 struct rb_node
*node
;
229 struct tree_entry
*entry
;
231 node
= __tree_search(root
, offset
, NULL
);
234 entry
= rb_entry(node
, struct tree_entry
, rb_node
);
236 rb_erase(node
, root
);
241 * add_extent_mapping tries a simple backward merge with existing
242 * mappings. The extent_map struct passed in will be inserted into
243 * the tree directly (no copies made, just a reference taken).
245 int add_extent_mapping(struct extent_map_tree
*tree
,
246 struct extent_map
*em
)
249 struct extent_map
*prev
= NULL
;
252 write_lock_irq(&tree
->lock
);
253 rb
= tree_insert(&tree
->map
, em
->end
, &em
->rb_node
);
255 prev
= rb_entry(rb
, struct extent_map
, rb_node
);
256 printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev
->start
, prev
->end
, em
->start
, em
->end
);
260 atomic_inc(&em
->refs
);
261 if (em
->start
!= 0) {
262 rb
= rb_prev(&em
->rb_node
);
264 prev
= rb_entry(rb
, struct extent_map
, rb_node
);
265 if (prev
&& prev
->end
+ 1 == em
->start
&&
266 ((em
->block_start
== EXTENT_MAP_HOLE
&&
267 prev
->block_start
== EXTENT_MAP_HOLE
) ||
268 (em
->block_start
== prev
->block_end
+ 1))) {
269 em
->start
= prev
->start
;
270 em
->block_start
= prev
->block_start
;
271 rb_erase(&prev
->rb_node
, &tree
->map
);
273 free_extent_map(prev
);
277 write_unlock_irq(&tree
->lock
);
280 EXPORT_SYMBOL(add_extent_mapping
);
283 * lookup_extent_mapping returns the first extent_map struct in the
284 * tree that intersects the [start, end] (inclusive) range. There may
285 * be additional objects in the tree that intersect, so check the object
286 * returned carefully to make sure you don't need additional lookups.
288 struct extent_map
*lookup_extent_mapping(struct extent_map_tree
*tree
,
291 struct extent_map
*em
;
292 struct rb_node
*rb_node
;
294 read_lock_irq(&tree
->lock
);
295 rb_node
= tree_search(&tree
->map
, start
);
300 if (IS_ERR(rb_node
)) {
301 em
= ERR_PTR(PTR_ERR(rb_node
));
304 em
= rb_entry(rb_node
, struct extent_map
, rb_node
);
305 if (em
->end
< start
|| em
->start
> end
) {
309 atomic_inc(&em
->refs
);
311 read_unlock_irq(&tree
->lock
);
314 EXPORT_SYMBOL(lookup_extent_mapping
);
317 * removes an extent_map struct from the tree. No reference counts are
318 * dropped, and no checks are done to see if the range is in use
320 int remove_extent_mapping(struct extent_map_tree
*tree
, struct extent_map
*em
)
324 write_lock_irq(&tree
->lock
);
325 ret
= tree_delete(&tree
->map
, em
->end
);
326 write_unlock_irq(&tree
->lock
);
329 EXPORT_SYMBOL(remove_extent_mapping
);
332 * utility function to look for merge candidates inside a given range.
333 * Any extents with matching state are merged together into a single
334 * extent in the tree. Extents with EXTENT_IO in their state field
335 * are not merged because the end_io handlers need to be able to do
336 * operations on them without sleeping (or doing allocations/splits).
338 * This should be called with the tree lock held.
340 static int merge_state(struct extent_map_tree
*tree
,
341 struct extent_state
*state
)
343 struct extent_state
*other
;
344 struct rb_node
*other_node
;
346 if (state
->state
& EXTENT_IOBITS
)
349 other_node
= rb_prev(&state
->rb_node
);
351 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
352 if (other
->end
== state
->start
- 1 &&
353 other
->state
== state
->state
) {
354 state
->start
= other
->start
;
356 rb_erase(&other
->rb_node
, &tree
->state
);
357 free_extent_state(other
);
360 other_node
= rb_next(&state
->rb_node
);
362 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
363 if (other
->start
== state
->end
+ 1 &&
364 other
->state
== state
->state
) {
365 other
->start
= state
->start
;
367 rb_erase(&state
->rb_node
, &tree
->state
);
368 free_extent_state(state
);
375 * insert an extent_state struct into the tree. 'bits' are set on the
376 * struct before it is inserted.
378 * This may return -EEXIST if the extent is already there, in which case the
379 * state struct is freed.
381 * The tree lock is not taken internally. This is a utility function and
382 * probably isn't what you want to call (see set/clear_extent_bit).
384 static int insert_state(struct extent_map_tree
*tree
,
385 struct extent_state
*state
, u64 start
, u64 end
,
388 struct rb_node
*node
;
391 printk("end < start %Lu %Lu\n", end
, start
);
394 state
->state
|= bits
;
395 state
->start
= start
;
397 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
399 struct extent_state
*found
;
400 found
= rb_entry(node
, struct extent_state
, rb_node
);
401 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found
->start
, found
->end
, start
, end
);
402 free_extent_state(state
);
405 merge_state(tree
, state
);
410 * split a given extent state struct in two, inserting the preallocated
411 * struct 'prealloc' as the newly created second half. 'split' indicates an
412 * offset inside 'orig' where it should be split.
415 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
416 * are two extent state structs in the tree:
417 * prealloc: [orig->start, split - 1]
418 * orig: [ split, orig->end ]
420 * The tree locks are not taken by this function. They need to be held
423 static int split_state(struct extent_map_tree
*tree
, struct extent_state
*orig
,
424 struct extent_state
*prealloc
, u64 split
)
426 struct rb_node
*node
;
427 prealloc
->start
= orig
->start
;
428 prealloc
->end
= split
- 1;
429 prealloc
->state
= orig
->state
;
432 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
434 struct extent_state
*found
;
435 found
= rb_entry(node
, struct extent_state
, rb_node
);
436 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found
->start
, found
->end
, prealloc
->start
, prealloc
->end
);
437 free_extent_state(prealloc
);
444 * utility function to clear some bits in an extent state struct.
445 * it will optionally wake up any one waiting on this state (wake == 1), or
446 * forcibly remove the state from the tree (delete == 1).
448 * If no bits are set on the state struct after clearing things, the
449 * struct is freed and removed from the tree
451 static int clear_state_bit(struct extent_map_tree
*tree
,
452 struct extent_state
*state
, int bits
, int wake
,
455 int ret
= state
->state
& bits
;
456 state
->state
&= ~bits
;
459 if (delete || state
->state
== 0) {
460 if (state
->in_tree
) {
461 rb_erase(&state
->rb_node
, &tree
->state
);
463 free_extent_state(state
);
468 merge_state(tree
, state
);
474 * clear some bits on a range in the tree. This may require splitting
475 * or inserting elements in the tree, so the gfp mask is used to
476 * indicate which allocations or sleeping are allowed.
478 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
479 * the given range from the tree regardless of state (ie for truncate).
481 * the range [start, end] is inclusive.
483 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
484 * bits were already set, or zero if none of the bits were already set.
486 int clear_extent_bit(struct extent_map_tree
*tree
, u64 start
, u64 end
,
487 int bits
, int wake
, int delete, gfp_t mask
)
489 struct extent_state
*state
;
490 struct extent_state
*prealloc
= NULL
;
491 struct rb_node
*node
;
497 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
498 prealloc
= alloc_extent_state(mask
);
503 write_lock_irqsave(&tree
->lock
, flags
);
505 * this search will find the extents that end after
508 node
= tree_search(&tree
->state
, start
);
511 state
= rb_entry(node
, struct extent_state
, rb_node
);
512 if (state
->start
> end
)
514 WARN_ON(state
->end
< start
);
517 * | ---- desired range ---- |
519 * | ------------- state -------------- |
521 * We need to split the extent we found, and may flip
522 * bits on second half.
524 * If the extent we found extends past our range, we
525 * just split and search again. It'll get split again
526 * the next time though.
528 * If the extent we found is inside our range, we clear
529 * the desired bit on it.
532 if (state
->start
< start
) {
533 err
= split_state(tree
, state
, prealloc
, start
);
534 BUG_ON(err
== -EEXIST
);
538 if (state
->end
<= end
) {
539 start
= state
->end
+ 1;
540 set
|= clear_state_bit(tree
, state
, bits
,
543 start
= state
->start
;
548 * | ---- desired range ---- |
550 * We need to split the extent, and clear the bit
553 if (state
->start
<= end
&& state
->end
> end
) {
554 err
= split_state(tree
, state
, prealloc
, end
+ 1);
555 BUG_ON(err
== -EEXIST
);
559 set
|= clear_state_bit(tree
, prealloc
, bits
,
565 start
= state
->end
+ 1;
566 set
|= clear_state_bit(tree
, state
, bits
, wake
, delete);
570 write_unlock_irqrestore(&tree
->lock
, flags
);
572 free_extent_state(prealloc
);
579 write_unlock_irqrestore(&tree
->lock
, flags
);
580 if (mask
& __GFP_WAIT
)
584 EXPORT_SYMBOL(clear_extent_bit
);
586 static int wait_on_state(struct extent_map_tree
*tree
,
587 struct extent_state
*state
)
590 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
591 read_unlock_irq(&tree
->lock
);
593 read_lock_irq(&tree
->lock
);
594 finish_wait(&state
->wq
, &wait
);
599 * waits for one or more bits to clear on a range in the state tree.
600 * The range [start, end] is inclusive.
601 * The tree lock is taken by this function
603 int wait_extent_bit(struct extent_map_tree
*tree
, u64 start
, u64 end
, int bits
)
605 struct extent_state
*state
;
606 struct rb_node
*node
;
608 read_lock_irq(&tree
->lock
);
612 * this search will find all the extents that end after
615 node
= tree_search(&tree
->state
, start
);
619 state
= rb_entry(node
, struct extent_state
, rb_node
);
621 if (state
->start
> end
)
624 if (state
->state
& bits
) {
625 start
= state
->start
;
626 atomic_inc(&state
->refs
);
627 wait_on_state(tree
, state
);
628 free_extent_state(state
);
631 start
= state
->end
+ 1;
636 if (need_resched()) {
637 read_unlock_irq(&tree
->lock
);
639 read_lock_irq(&tree
->lock
);
643 read_unlock_irq(&tree
->lock
);
646 EXPORT_SYMBOL(wait_extent_bit
);
649 * set some bits on a range in the tree. This may require allocations
650 * or sleeping, so the gfp mask is used to indicate what is allowed.
652 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
653 * range already has the desired bits set. The start of the existing
654 * range is returned in failed_start in this case.
656 * [start, end] is inclusive
657 * This takes the tree lock.
659 int set_extent_bit(struct extent_map_tree
*tree
, u64 start
, u64 end
, int bits
,
660 int exclusive
, u64
*failed_start
, gfp_t mask
)
662 struct extent_state
*state
;
663 struct extent_state
*prealloc
= NULL
;
664 struct rb_node
*node
;
671 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
672 prealloc
= alloc_extent_state(mask
);
677 write_lock_irqsave(&tree
->lock
, flags
);
679 * this search will find all the extents that end after
682 node
= tree_search(&tree
->state
, start
);
684 err
= insert_state(tree
, prealloc
, start
, end
, bits
);
686 BUG_ON(err
== -EEXIST
);
690 state
= rb_entry(node
, struct extent_state
, rb_node
);
691 last_start
= state
->start
;
692 last_end
= state
->end
;
695 * | ---- desired range ---- |
698 * Just lock what we found and keep going
700 if (state
->start
== start
&& state
->end
<= end
) {
701 set
= state
->state
& bits
;
702 if (set
&& exclusive
) {
703 *failed_start
= state
->start
;
707 state
->state
|= bits
;
708 start
= state
->end
+ 1;
709 merge_state(tree
, state
);
714 * | ---- desired range ---- |
717 * | ------------- state -------------- |
719 * We need to split the extent we found, and may flip bits on
722 * If the extent we found extends past our
723 * range, we just split and search again. It'll get split
724 * again the next time though.
726 * If the extent we found is inside our range, we set the
729 if (state
->start
< start
) {
730 set
= state
->state
& bits
;
731 if (exclusive
&& set
) {
732 *failed_start
= start
;
736 err
= split_state(tree
, state
, prealloc
, start
);
737 BUG_ON(err
== -EEXIST
);
741 if (state
->end
<= end
) {
742 state
->state
|= bits
;
743 start
= state
->end
+ 1;
744 merge_state(tree
, state
);
746 start
= state
->start
;
751 * | ---- desired range ---- |
752 * | state | or | state |
754 * There's a hole, we need to insert something in it and
755 * ignore the extent we found.
757 if (state
->start
> start
) {
759 if (end
< last_start
)
762 this_end
= last_start
-1;
763 err
= insert_state(tree
, prealloc
, start
, this_end
,
766 BUG_ON(err
== -EEXIST
);
769 start
= this_end
+ 1;
773 * | ---- desired range ---- |
775 * We need to split the extent, and set the bit
778 if (state
->start
<= end
&& state
->end
> end
) {
779 set
= state
->state
& bits
;
780 if (exclusive
&& set
) {
781 *failed_start
= start
;
785 err
= split_state(tree
, state
, prealloc
, end
+ 1);
786 BUG_ON(err
== -EEXIST
);
788 prealloc
->state
|= bits
;
789 merge_state(tree
, prealloc
);
797 write_unlock_irqrestore(&tree
->lock
, flags
);
799 free_extent_state(prealloc
);
806 write_unlock_irqrestore(&tree
->lock
, flags
);
807 if (mask
& __GFP_WAIT
)
811 EXPORT_SYMBOL(set_extent_bit
);
813 /* wrappers around set/clear extent bit */
814 int set_extent_dirty(struct extent_map_tree
*tree
, u64 start
, u64 end
,
817 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, 0, NULL
,
820 EXPORT_SYMBOL(set_extent_dirty
);
822 int set_extent_delalloc(struct extent_map_tree
*tree
, u64 start
, u64 end
,
825 return set_extent_bit(tree
, start
, end
,
826 EXTENT_DELALLOC
| EXTENT_DIRTY
, 0, NULL
,
829 EXPORT_SYMBOL(set_extent_delalloc
);
831 int clear_extent_dirty(struct extent_map_tree
*tree
, u64 start
, u64 end
,
834 return clear_extent_bit(tree
, start
, end
,
835 EXTENT_DIRTY
| EXTENT_DELALLOC
, 0, 0, mask
);
837 EXPORT_SYMBOL(clear_extent_dirty
);
839 int set_extent_new(struct extent_map_tree
*tree
, u64 start
, u64 end
,
842 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, NULL
,
845 EXPORT_SYMBOL(set_extent_new
);
847 int clear_extent_new(struct extent_map_tree
*tree
, u64 start
, u64 end
,
850 return clear_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, 0, mask
);
852 EXPORT_SYMBOL(clear_extent_new
);
854 int set_extent_uptodate(struct extent_map_tree
*tree
, u64 start
, u64 end
,
857 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, NULL
,
860 EXPORT_SYMBOL(set_extent_uptodate
);
862 int clear_extent_uptodate(struct extent_map_tree
*tree
, u64 start
, u64 end
,
865 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0, mask
);
867 EXPORT_SYMBOL(clear_extent_uptodate
);
869 int set_extent_writeback(struct extent_map_tree
*tree
, u64 start
, u64 end
,
872 return set_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
,
875 EXPORT_SYMBOL(set_extent_writeback
);
877 int clear_extent_writeback(struct extent_map_tree
*tree
, u64 start
, u64 end
,
880 return clear_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
, 1, 0, mask
);
882 EXPORT_SYMBOL(clear_extent_writeback
);
884 int wait_on_extent_writeback(struct extent_map_tree
*tree
, u64 start
, u64 end
)
886 return wait_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
);
888 EXPORT_SYMBOL(wait_on_extent_writeback
);
891 * locks a range in ascending order, waiting for any locked regions
892 * it hits on the way. [start,end] are inclusive, and this will sleep.
894 int lock_extent(struct extent_map_tree
*tree
, u64 start
, u64 end
, gfp_t mask
)
899 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1,
900 &failed_start
, mask
);
901 if (err
== -EEXIST
&& (mask
& __GFP_WAIT
)) {
902 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
903 start
= failed_start
;
907 WARN_ON(start
> end
);
911 EXPORT_SYMBOL(lock_extent
);
913 int unlock_extent(struct extent_map_tree
*tree
, u64 start
, u64 end
,
916 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, mask
);
918 EXPORT_SYMBOL(unlock_extent
);
921 * helper function to set pages and extents in the tree dirty
923 int set_range_dirty(struct extent_map_tree
*tree
, u64 start
, u64 end
)
925 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
926 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
929 while (index
<= end_index
) {
930 page
= find_get_page(tree
->mapping
, index
);
932 __set_page_dirty_nobuffers(page
);
933 page_cache_release(page
);
936 set_extent_dirty(tree
, start
, end
, GFP_NOFS
);
939 EXPORT_SYMBOL(set_range_dirty
);
942 * helper function to set both pages and extents in the tree writeback
944 int set_range_writeback(struct extent_map_tree
*tree
, u64 start
, u64 end
)
946 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
947 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
950 while (index
<= end_index
) {
951 page
= find_get_page(tree
->mapping
, index
);
953 set_page_writeback(page
);
954 page_cache_release(page
);
957 set_extent_writeback(tree
, start
, end
, GFP_NOFS
);
960 EXPORT_SYMBOL(set_range_writeback
);
962 int find_first_extent_bit(struct extent_map_tree
*tree
, u64 start
,
963 u64
*start_ret
, u64
*end_ret
, int bits
)
965 struct rb_node
*node
;
966 struct extent_state
*state
;
969 write_lock_irq(&tree
->lock
);
971 * this search will find all the extents that end after
974 node
= tree_search(&tree
->state
, start
);
975 if (!node
|| IS_ERR(node
)) {
980 state
= rb_entry(node
, struct extent_state
, rb_node
);
981 if (state
->state
& bits
) {
982 *start_ret
= state
->start
;
983 *end_ret
= state
->end
;
987 node
= rb_next(node
);
992 write_unlock_irq(&tree
->lock
);
995 EXPORT_SYMBOL(find_first_extent_bit
);
997 u64
find_lock_delalloc_range(struct extent_map_tree
*tree
,
998 u64 start
, u64 lock_start
, u64
*end
, u64 max_bytes
)
1000 struct rb_node
*node
;
1001 struct extent_state
*state
;
1002 u64 cur_start
= start
;
1004 u64 total_bytes
= 0;
1006 write_lock_irq(&tree
->lock
);
1008 * this search will find all the extents that end after
1012 node
= tree_search(&tree
->state
, cur_start
);
1013 if (!node
|| IS_ERR(node
)) {
1018 state
= rb_entry(node
, struct extent_state
, rb_node
);
1019 if (state
->start
!= cur_start
) {
1022 if (!(state
->state
& EXTENT_DELALLOC
)) {
1025 if (state
->start
>= lock_start
) {
1026 if (state
->state
& EXTENT_LOCKED
) {
1028 atomic_inc(&state
->refs
);
1029 write_unlock_irq(&tree
->lock
);
1031 write_lock_irq(&tree
->lock
);
1032 finish_wait(&state
->wq
, &wait
);
1033 free_extent_state(state
);
1036 state
->state
|= EXTENT_LOCKED
;
1040 cur_start
= state
->end
+ 1;
1041 node
= rb_next(node
);
1044 total_bytes
= state
->end
- state
->start
+ 1;
1045 if (total_bytes
>= max_bytes
)
1049 write_unlock_irq(&tree
->lock
);
1054 * helper function to lock both pages and extents in the tree.
1055 * pages must be locked first.
1057 int lock_range(struct extent_map_tree
*tree
, u64 start
, u64 end
)
1059 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1060 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1064 while (index
<= end_index
) {
1065 page
= grab_cache_page(tree
->mapping
, index
);
1071 err
= PTR_ERR(page
);
1076 lock_extent(tree
, start
, end
, GFP_NOFS
);
1081 * we failed above in getting the page at 'index', so we undo here
1082 * up to but not including the page at 'index'
1085 index
= start
>> PAGE_CACHE_SHIFT
;
1086 while (index
< end_index
) {
1087 page
= find_get_page(tree
->mapping
, index
);
1089 page_cache_release(page
);
1094 EXPORT_SYMBOL(lock_range
);
1097 * helper function to unlock both pages and extents in the tree.
1099 int unlock_range(struct extent_map_tree
*tree
, u64 start
, u64 end
)
1101 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1102 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1105 while (index
<= end_index
) {
1106 page
= find_get_page(tree
->mapping
, index
);
1108 page_cache_release(page
);
1111 unlock_extent(tree
, start
, end
, GFP_NOFS
);
1114 EXPORT_SYMBOL(unlock_range
);
1116 int set_state_private(struct extent_map_tree
*tree
, u64 start
, u64
private)
1118 struct rb_node
*node
;
1119 struct extent_state
*state
;
1122 write_lock_irq(&tree
->lock
);
1124 * this search will find all the extents that end after
1127 node
= tree_search(&tree
->state
, start
);
1128 if (!node
|| IS_ERR(node
)) {
1132 state
= rb_entry(node
, struct extent_state
, rb_node
);
1133 if (state
->start
!= start
) {
1137 state
->private = private;
1139 write_unlock_irq(&tree
->lock
);
1144 int get_state_private(struct extent_map_tree
*tree
, u64 start
, u64
*private)
1146 struct rb_node
*node
;
1147 struct extent_state
*state
;
1150 read_lock_irq(&tree
->lock
);
1152 * this search will find all the extents that end after
1155 node
= tree_search(&tree
->state
, start
);
1156 if (!node
|| IS_ERR(node
)) {
1160 state
= rb_entry(node
, struct extent_state
, rb_node
);
1161 if (state
->start
!= start
) {
1165 *private = state
->private;
1167 read_unlock_irq(&tree
->lock
);
1172 * searches a range in the state tree for a given mask.
1173 * If 'filled' == 1, this returns 1 only if ever extent in the tree
1174 * has the bits set. Otherwise, 1 is returned if any bit in the
1175 * range is found set.
1177 static int test_range_bit(struct extent_map_tree
*tree
, u64 start
, u64 end
,
1178 int bits
, int filled
)
1180 struct extent_state
*state
= NULL
;
1181 struct rb_node
*node
;
1184 read_lock_irq(&tree
->lock
);
1185 node
= tree_search(&tree
->state
, start
);
1186 while (node
&& start
<= end
) {
1187 state
= rb_entry(node
, struct extent_state
, rb_node
);
1188 if (state
->start
> end
)
1191 if (filled
&& state
->start
> start
) {
1195 if (state
->state
& bits
) {
1199 } else if (filled
) {
1203 start
= state
->end
+ 1;
1206 node
= rb_next(node
);
1208 read_unlock_irq(&tree
->lock
);
1213 * helper function to set a given page up to date if all the
1214 * extents in the tree for that page are up to date
1216 static int check_page_uptodate(struct extent_map_tree
*tree
,
1219 u64 start
= page
->index
<< PAGE_CACHE_SHIFT
;
1220 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1221 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1))
1222 SetPageUptodate(page
);
1227 * helper function to unlock a page if all the extents in the tree
1228 * for that page are unlocked
1230 static int check_page_locked(struct extent_map_tree
*tree
,
1233 u64 start
= page
->index
<< PAGE_CACHE_SHIFT
;
1234 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1235 if (!test_range_bit(tree
, start
, end
, EXTENT_LOCKED
, 0))
1241 * helper function to end page writeback if all the extents
1242 * in the tree for that page are done with writeback
1244 static int check_page_writeback(struct extent_map_tree
*tree
,
1247 u64 start
= page
->index
<< PAGE_CACHE_SHIFT
;
1248 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1249 if (!test_range_bit(tree
, start
, end
, EXTENT_WRITEBACK
, 0))
1250 end_page_writeback(page
);
1254 /* lots and lots of room for performance fixes in the end_bio funcs */
1257 * after a writepage IO is done, we need to:
1258 * clear the uptodate bits on error
1259 * clear the writeback bits in the extent tree for this IO
1260 * end_page_writeback if the page has no more pending IO
1262 * Scheduling is not allowed, so the extent state tree is expected
1263 * to have one and only one object corresponding to this IO.
1265 static int end_bio_extent_writepage(struct bio
*bio
,
1266 unsigned int bytes_done
, int err
)
1268 const int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1269 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1270 struct extent_map_tree
*tree
= bio
->bi_private
;
1279 struct page
*page
= bvec
->bv_page
;
1280 start
= (page
->index
<< PAGE_CACHE_SHIFT
) + bvec
->bv_offset
;
1281 end
= start
+ bvec
->bv_len
- 1;
1283 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1288 if (--bvec
>= bio
->bi_io_vec
)
1289 prefetchw(&bvec
->bv_page
->flags
);
1292 clear_extent_uptodate(tree
, start
, end
, GFP_ATOMIC
);
1293 ClearPageUptodate(page
);
1296 clear_extent_writeback(tree
, start
, end
, GFP_ATOMIC
);
1299 end_page_writeback(page
);
1301 check_page_writeback(tree
, page
);
1302 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
1303 tree
->ops
->writepage_end_io_hook(page
, start
, end
);
1304 } while (bvec
>= bio
->bi_io_vec
);
1311 * after a readpage IO is done, we need to:
1312 * clear the uptodate bits on error
1313 * set the uptodate bits if things worked
1314 * set the page up to date if all extents in the tree are uptodate
1315 * clear the lock bit in the extent tree
1316 * unlock the page if there are no other extents locked for it
1318 * Scheduling is not allowed, so the extent state tree is expected
1319 * to have one and only one object corresponding to this IO.
1321 static int end_bio_extent_readpage(struct bio
*bio
,
1322 unsigned int bytes_done
, int err
)
1324 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1325 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1326 struct extent_map_tree
*tree
= bio
->bi_private
;
1336 struct page
*page
= bvec
->bv_page
;
1337 start
= (page
->index
<< PAGE_CACHE_SHIFT
) + bvec
->bv_offset
;
1338 end
= start
+ bvec
->bv_len
- 1;
1340 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1345 if (--bvec
>= bio
->bi_io_vec
)
1346 prefetchw(&bvec
->bv_page
->flags
);
1348 if (uptodate
&& tree
->ops
&& tree
->ops
->readpage_end_io_hook
) {
1349 ret
= tree
->ops
->readpage_end_io_hook(page
, start
, end
);
1354 set_extent_uptodate(tree
, start
, end
, GFP_ATOMIC
);
1356 SetPageUptodate(page
);
1358 check_page_uptodate(tree
, page
);
1360 ClearPageUptodate(page
);
1364 unlock_extent(tree
, start
, end
, GFP_ATOMIC
);
1369 check_page_locked(tree
, page
);
1370 } while (bvec
>= bio
->bi_io_vec
);
1377 * IO done from prepare_write is pretty simple, we just unlock
1378 * the structs in the extent tree when done, and set the uptodate bits
1381 static int end_bio_extent_preparewrite(struct bio
*bio
,
1382 unsigned int bytes_done
, int err
)
1384 const int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1385 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1386 struct extent_map_tree
*tree
= bio
->bi_private
;
1394 struct page
*page
= bvec
->bv_page
;
1395 start
= (page
->index
<< PAGE_CACHE_SHIFT
) + bvec
->bv_offset
;
1396 end
= start
+ bvec
->bv_len
- 1;
1398 if (--bvec
>= bio
->bi_io_vec
)
1399 prefetchw(&bvec
->bv_page
->flags
);
1402 set_extent_uptodate(tree
, start
, end
, GFP_ATOMIC
);
1404 ClearPageUptodate(page
);
1408 unlock_extent(tree
, start
, end
, GFP_ATOMIC
);
1410 } while (bvec
>= bio
->bi_io_vec
);
1416 static int submit_extent_page(int rw
, struct extent_map_tree
*tree
,
1417 struct page
*page
, sector_t sector
,
1418 size_t size
, unsigned long offset
,
1419 struct block_device
*bdev
,
1420 bio_end_io_t end_io_func
)
1425 bio
= bio_alloc(GFP_NOIO
, 1);
1427 bio
->bi_sector
= sector
;
1428 bio
->bi_bdev
= bdev
;
1429 bio
->bi_io_vec
[0].bv_page
= page
;
1430 bio
->bi_io_vec
[0].bv_len
= size
;
1431 bio
->bi_io_vec
[0].bv_offset
= offset
;
1435 bio
->bi_size
= size
;
1437 bio
->bi_end_io
= end_io_func
;
1438 bio
->bi_private
= tree
;
1441 submit_bio(rw
, bio
);
1443 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
1450 void set_page_extent_mapped(struct page
*page
)
1452 if (!PagePrivate(page
)) {
1453 SetPagePrivate(page
);
1454 WARN_ON(!page
->mapping
->a_ops
->invalidatepage
);
1455 set_page_private(page
, 1);
1456 page_cache_get(page
);
1461 * basic readpage implementation. Locked extent state structs are inserted
1462 * into the tree that are removed when the IO is done (by the end_io
1465 int extent_read_full_page(struct extent_map_tree
*tree
, struct page
*page
,
1466 get_extent_t
*get_extent
)
1468 struct inode
*inode
= page
->mapping
->host
;
1469 u64 start
= page
->index
<< PAGE_CACHE_SHIFT
;
1470 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
1474 u64 last_byte
= i_size_read(inode
);
1478 struct extent_map
*em
;
1479 struct block_device
*bdev
;
1482 size_t page_offset
= 0;
1484 size_t blocksize
= inode
->i_sb
->s_blocksize
;
1486 set_page_extent_mapped(page
);
1489 lock_extent(tree
, start
, end
, GFP_NOFS
);
1491 while (cur
<= end
) {
1492 if (cur
>= last_byte
) {
1493 iosize
= PAGE_CACHE_SIZE
- page_offset
;
1494 zero_user_page(page
, page_offset
, iosize
, KM_USER0
);
1495 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
1497 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1500 em
= get_extent(inode
, page
, page_offset
, cur
, end
, 0);
1501 if (IS_ERR(em
) || !em
) {
1503 unlock_extent(tree
, cur
, end
, GFP_NOFS
);
1507 extent_offset
= cur
- em
->start
;
1508 BUG_ON(em
->end
< cur
);
1511 iosize
= min(em
->end
- cur
, end
- cur
) + 1;
1512 cur_end
= min(em
->end
, end
);
1513 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
1514 sector
= (em
->block_start
+ extent_offset
) >> 9;
1516 block_start
= em
->block_start
;
1517 free_extent_map(em
);
1520 /* we've found a hole, just zero and go on */
1521 if (block_start
== EXTENT_MAP_HOLE
) {
1522 zero_user_page(page
, page_offset
, iosize
, KM_USER0
);
1523 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
1525 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1527 page_offset
+= iosize
;
1530 /* the get_extent function already copied into the page */
1531 if (test_range_bit(tree
, cur
, cur_end
, EXTENT_UPTODATE
, 1)) {
1532 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1534 page_offset
+= iosize
;
1539 if (tree
->ops
&& tree
->ops
->readpage_io_hook
) {
1540 ret
= tree
->ops
->readpage_io_hook(page
, cur
,
1544 ret
= submit_extent_page(READ
, tree
, page
,
1545 sector
, iosize
, page_offset
,
1546 bdev
, end_bio_extent_readpage
);
1551 page_offset
+= iosize
;
1555 if (!PageError(page
))
1556 SetPageUptodate(page
);
1561 EXPORT_SYMBOL(extent_read_full_page
);
1564 * the writepage semantics are similar to regular writepage. extent
1565 * records are inserted to lock ranges in the tree, and as dirty areas
1566 * are found, they are marked writeback. Then the lock bits are removed
1567 * and the end_io handler clears the writeback ranges
1569 int extent_write_full_page(struct extent_map_tree
*tree
, struct page
*page
,
1570 get_extent_t
*get_extent
,
1571 struct writeback_control
*wbc
)
1573 struct inode
*inode
= page
->mapping
->host
;
1574 u64 start
= page
->index
<< PAGE_CACHE_SHIFT
;
1575 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
1579 u64 last_byte
= i_size_read(inode
);
1582 struct extent_map
*em
;
1583 struct block_device
*bdev
;
1586 size_t page_offset
= 0;
1589 loff_t i_size
= i_size_read(inode
);
1590 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
1594 WARN_ON(!PageLocked(page
));
1595 if (page
->index
> end_index
) {
1596 clear_extent_dirty(tree
, start
, page_end
, GFP_NOFS
);
1601 if (page
->index
== end_index
) {
1602 size_t offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
1603 zero_user_page(page
, offset
,
1604 PAGE_CACHE_SIZE
- offset
, KM_USER0
);
1607 set_page_extent_mapped(page
);
1609 lock_extent(tree
, start
, page_end
, GFP_NOFS
);
1610 nr_delalloc
= find_lock_delalloc_range(tree
, start
, page_end
+ 1,
1614 tree
->ops
->fill_delalloc(inode
, start
, delalloc_end
);
1615 if (delalloc_end
>= page_end
+ 1) {
1616 clear_extent_bit(tree
, page_end
+ 1, delalloc_end
,
1617 EXTENT_LOCKED
| EXTENT_DELALLOC
,
1620 clear_extent_bit(tree
, start
, page_end
, EXTENT_DELALLOC
,
1622 if (test_range_bit(tree
, start
, page_end
, EXTENT_DELALLOC
, 0)) {
1623 printk("found delalloc bits after clear extent_bit\n");
1625 } else if (test_range_bit(tree
, start
, page_end
, EXTENT_DELALLOC
, 0)) {
1626 printk("found delalloc bits after find_delalloc_range returns 0\n");
1630 if (test_range_bit(tree
, start
, page_end
, EXTENT_DELALLOC
, 0)) {
1631 printk("found delalloc bits after lock_extent\n");
1634 if (last_byte
<= start
) {
1635 clear_extent_dirty(tree
, start
, page_end
, GFP_NOFS
);
1639 set_extent_uptodate(tree
, start
, page_end
, GFP_NOFS
);
1640 blocksize
= inode
->i_sb
->s_blocksize
;
1642 while (cur
<= end
) {
1643 if (cur
>= last_byte
) {
1644 clear_extent_dirty(tree
, cur
, page_end
, GFP_NOFS
);
1647 em
= get_extent(inode
, page
, page_offset
, cur
, end
, 0);
1648 if (IS_ERR(em
) || !em
) {
1653 extent_offset
= cur
- em
->start
;
1654 BUG_ON(em
->end
< cur
);
1656 iosize
= min(em
->end
- cur
, end
- cur
) + 1;
1657 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
1658 sector
= (em
->block_start
+ extent_offset
) >> 9;
1660 block_start
= em
->block_start
;
1661 free_extent_map(em
);
1664 if (block_start
== EXTENT_MAP_HOLE
||
1665 block_start
== EXTENT_MAP_INLINE
) {
1666 clear_extent_dirty(tree
, cur
,
1667 cur
+ iosize
- 1, GFP_NOFS
);
1669 page_offset
+= iosize
;
1673 /* leave this out until we have a page_mkwrite call */
1674 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
1677 page_offset
+= iosize
;
1680 clear_extent_dirty(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1681 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
1682 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
1690 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
1691 ret
= submit_extent_page(WRITE
, tree
, page
, sector
,
1692 iosize
, page_offset
, bdev
,
1693 end_bio_extent_writepage
);
1698 page_offset
+= iosize
;
1702 unlock_extent(tree
, start
, page_end
, GFP_NOFS
);
1706 EXPORT_SYMBOL(extent_write_full_page
);
1709 * basic invalidatepage code, this waits on any locked or writeback
1710 * ranges corresponding to the page, and then deletes any extent state
1711 * records from the tree
1713 int extent_invalidatepage(struct extent_map_tree
*tree
,
1714 struct page
*page
, unsigned long offset
)
1716 u64 start
= (page
->index
<< PAGE_CACHE_SHIFT
);
1717 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1718 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
1720 start
+= (offset
+ blocksize
-1) & ~(blocksize
- 1);
1724 lock_extent(tree
, start
, end
, GFP_NOFS
);
1725 wait_on_extent_writeback(tree
, start
, end
);
1726 clear_extent_bit(tree
, start
, end
,
1727 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
,
1731 EXPORT_SYMBOL(extent_invalidatepage
);
1734 * simple commit_write call, set_range_dirty is used to mark both
1735 * the pages and the extent records as dirty
1737 int extent_commit_write(struct extent_map_tree
*tree
,
1738 struct inode
*inode
, struct page
*page
,
1739 unsigned from
, unsigned to
)
1741 loff_t pos
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
1743 set_page_extent_mapped(page
);
1744 set_page_dirty(page
);
1746 if (pos
> inode
->i_size
) {
1747 i_size_write(inode
, pos
);
1748 mark_inode_dirty(inode
);
1752 EXPORT_SYMBOL(extent_commit_write
);
1754 int extent_prepare_write(struct extent_map_tree
*tree
,
1755 struct inode
*inode
, struct page
*page
,
1756 unsigned from
, unsigned to
, get_extent_t
*get_extent
)
1758 u64 page_start
= page
->index
<< PAGE_CACHE_SHIFT
;
1759 u64 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
1761 u64 orig_block_start
;
1764 struct extent_map
*em
;
1765 unsigned blocksize
= 1 << inode
->i_blkbits
;
1766 size_t page_offset
= 0;
1767 size_t block_off_start
;
1768 size_t block_off_end
;
1774 set_page_extent_mapped(page
);
1776 block_start
= (page_start
+ from
) & ~((u64
)blocksize
- 1);
1777 block_end
= (page_start
+ to
- 1) | (blocksize
- 1);
1778 orig_block_start
= block_start
;
1780 lock_extent(tree
, page_start
, page_end
, GFP_NOFS
);
1781 while(block_start
<= block_end
) {
1782 em
= get_extent(inode
, page
, page_offset
, block_start
,
1784 if (IS_ERR(em
) || !em
) {
1787 cur_end
= min(block_end
, em
->end
);
1788 block_off_start
= block_start
& (PAGE_CACHE_SIZE
- 1);
1789 block_off_end
= block_off_start
+ blocksize
;
1790 isnew
= clear_extent_new(tree
, block_start
, cur_end
, GFP_NOFS
);
1792 if (!PageUptodate(page
) && isnew
&&
1793 (block_off_end
> to
|| block_off_start
< from
)) {
1796 kaddr
= kmap_atomic(page
, KM_USER0
);
1797 if (block_off_end
> to
)
1798 memset(kaddr
+ to
, 0, block_off_end
- to
);
1799 if (block_off_start
< from
)
1800 memset(kaddr
+ block_off_start
, 0,
1801 from
- block_off_start
);
1802 flush_dcache_page(page
);
1803 kunmap_atomic(kaddr
, KM_USER0
);
1805 if (!isnew
&& !PageUptodate(page
) &&
1806 (block_off_end
> to
|| block_off_start
< from
) &&
1807 !test_range_bit(tree
, block_start
, cur_end
,
1808 EXTENT_UPTODATE
, 1)) {
1810 u64 extent_offset
= block_start
- em
->start
;
1812 sector
= (em
->block_start
+ extent_offset
) >> 9;
1813 iosize
= (cur_end
- block_start
+ blocksize
- 1) &
1814 ~((u64
)blocksize
- 1);
1816 * we've already got the extent locked, but we
1817 * need to split the state such that our end_bio
1818 * handler can clear the lock.
1820 set_extent_bit(tree
, block_start
,
1821 block_start
+ iosize
- 1,
1822 EXTENT_LOCKED
, 0, NULL
, GFP_NOFS
);
1823 ret
= submit_extent_page(READ
, tree
, page
,
1824 sector
, iosize
, page_offset
, em
->bdev
,
1825 end_bio_extent_preparewrite
);
1827 block_start
= block_start
+ iosize
;
1829 set_extent_uptodate(tree
, block_start
, cur_end
,
1831 unlock_extent(tree
, block_start
, cur_end
, GFP_NOFS
);
1832 block_start
= cur_end
+ 1;
1834 page_offset
= block_start
& (PAGE_CACHE_SIZE
- 1);
1835 free_extent_map(em
);
1838 wait_extent_bit(tree
, orig_block_start
,
1839 block_end
, EXTENT_LOCKED
);
1841 check_page_uptodate(tree
, page
);
1843 /* FIXME, zero out newly allocated blocks on error */
1846 EXPORT_SYMBOL(extent_prepare_write
);
1849 * a helper for releasepage. As long as there are no locked extents
1850 * in the range corresponding to the page, both state records and extent
1851 * map records are removed
1853 int try_release_extent_mapping(struct extent_map_tree
*tree
, struct page
*page
)
1855 struct extent_map
*em
;
1856 u64 start
= page
->index
<< PAGE_CACHE_SHIFT
;
1857 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1858 u64 orig_start
= start
;
1861 while (start
<= end
) {
1862 em
= lookup_extent_mapping(tree
, start
, end
);
1863 if (!em
|| IS_ERR(em
))
1865 if (!test_range_bit(tree
, em
->start
, em
->end
,
1866 EXTENT_LOCKED
, 0)) {
1867 remove_extent_mapping(tree
, em
);
1868 /* once for the rb tree */
1869 free_extent_map(em
);
1871 start
= em
->end
+ 1;
1873 free_extent_map(em
);
1875 if (test_range_bit(tree
, orig_start
, end
, EXTENT_LOCKED
, 0))
1878 clear_extent_bit(tree
, orig_start
, end
, EXTENT_UPTODATE
,
1882 EXPORT_SYMBOL(try_release_extent_mapping
);
1884 sector_t
extent_bmap(struct address_space
*mapping
, sector_t iblock
,
1885 get_extent_t
*get_extent
)
1887 struct inode
*inode
= mapping
->host
;
1888 u64 start
= iblock
<< inode
->i_blkbits
;
1889 u64 end
= start
+ (1 << inode
->i_blkbits
) - 1;
1890 struct extent_map
*em
;
1892 em
= get_extent(inode
, NULL
, 0, start
, end
, 0);
1893 if (!em
|| IS_ERR(em
))
1896 if (em
->block_start
== EXTENT_MAP_INLINE
||
1897 em
->block_start
== EXTENT_MAP_HOLE
)
1900 return (em
->block_start
+ start
- em
->start
) >> inode
->i_blkbits
;
1903 static struct extent_buffer
*__alloc_extent_buffer(gfp_t mask
)
1905 struct extent_buffer
*eb
= NULL
;
1907 spin_lock(&extent_buffers_lock
);
1908 if (!list_empty(&extent_buffers
)) {
1909 eb
= list_entry(extent_buffers
.next
, struct extent_buffer
,
1911 list_del(&eb
->list
);
1912 WARN_ON(nr_extent_buffers
== 0);
1913 nr_extent_buffers
--;
1915 spin_unlock(&extent_buffers_lock
);
1918 memset(eb
, 0, sizeof(*eb
));
1920 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
1922 spin_lock(&extent_buffers_lock
);
1923 list_add(&eb
->leak_list
, &buffers
);
1924 spin_unlock(&extent_buffers_lock
);
1929 static void __free_extent_buffer(struct extent_buffer
*eb
)
1932 spin_lock(&extent_buffers_lock
);
1933 list_del_init(&eb
->leak_list
);
1934 spin_unlock(&extent_buffers_lock
);
1936 if (nr_extent_buffers
>= MAX_EXTENT_BUFFER_CACHE
) {
1937 kmem_cache_free(extent_buffer_cache
, eb
);
1939 spin_lock(&extent_buffers_lock
);
1940 list_add(&eb
->list
, &extent_buffers
);
1941 nr_extent_buffers
++;
1942 spin_unlock(&extent_buffers_lock
);
1946 static inline struct page
*extent_buffer_page(struct extent_buffer
*eb
, int i
)
1950 return eb
->first_page
;
1951 i
+= eb
->start
>> PAGE_CACHE_SHIFT
;
1952 p
= find_get_page(eb
->first_page
->mapping
, i
);
1953 page_cache_release(p
);
1957 struct extent_buffer
*alloc_extent_buffer(struct extent_map_tree
*tree
,
1958 u64 start
, unsigned long len
,
1961 unsigned long num_pages
= ((start
+ len
- 1) >> PAGE_CACHE_SHIFT
) -
1962 (start
>> PAGE_CACHE_SHIFT
) + 1;
1964 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1965 struct extent_buffer
*eb
;
1967 struct address_space
*mapping
= tree
->mapping
;
1970 eb
= __alloc_extent_buffer(mask
);
1971 if (!eb
|| IS_ERR(eb
))
1974 eb
->alloc_addr
= __builtin_return_address(0);
1977 atomic_set(&eb
->refs
, 1);
1979 for (i
= 0; i
< num_pages
; i
++, index
++) {
1980 p
= find_or_create_page(mapping
, index
, mask
| __GFP_HIGHMEM
);
1982 /* make sure the free only frees the pages we've
1983 * grabbed a reference on
1985 eb
->len
= i
<< PAGE_CACHE_SHIFT
;
1986 eb
->start
&= ~((u64
)PAGE_CACHE_SIZE
- 1);
1989 set_page_extent_mapped(p
);
1992 if (!PageUptodate(p
))
1997 eb
->flags
|= EXTENT_UPTODATE
;
2000 free_extent_buffer(eb
);
2003 EXPORT_SYMBOL(alloc_extent_buffer
);
2005 struct extent_buffer
*find_extent_buffer(struct extent_map_tree
*tree
,
2006 u64 start
, unsigned long len
,
2009 unsigned long num_pages
= ((start
+ len
- 1) >> PAGE_CACHE_SHIFT
) -
2010 (start
>> PAGE_CACHE_SHIFT
) + 1;
2012 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
2013 struct extent_buffer
*eb
;
2015 struct address_space
*mapping
= tree
->mapping
;
2017 eb
= __alloc_extent_buffer(mask
);
2018 if (!eb
|| IS_ERR(eb
))
2021 eb
->alloc_addr
= __builtin_return_address(0);
2024 atomic_set(&eb
->refs
, 1);
2026 for (i
= 0; i
< num_pages
; i
++, index
++) {
2027 p
= find_get_page(mapping
, index
);
2029 /* make sure the free only frees the pages we've
2030 * grabbed a reference on
2032 eb
->len
= i
<< PAGE_CACHE_SHIFT
;
2033 eb
->start
&= ~((u64
)PAGE_CACHE_SIZE
- 1);
2036 set_page_extent_mapped(p
);
2042 free_extent_buffer(eb
);
2045 EXPORT_SYMBOL(find_extent_buffer
);
2047 void free_extent_buffer(struct extent_buffer
*eb
)
2050 unsigned long num_pages
;
2055 if (!atomic_dec_and_test(&eb
->refs
))
2058 num_pages
= ((eb
->start
+ eb
->len
- 1) >> PAGE_CACHE_SHIFT
) -
2059 (eb
->start
>> PAGE_CACHE_SHIFT
) + 1;
2062 page_cache_release(eb
->first_page
);
2063 for (i
= 1; i
< num_pages
; i
++) {
2064 page_cache_release(extent_buffer_page(eb
, i
));
2066 __free_extent_buffer(eb
);
2068 EXPORT_SYMBOL(free_extent_buffer
);
2070 int clear_extent_buffer_dirty(struct extent_map_tree
*tree
,
2071 struct extent_buffer
*eb
)
2075 unsigned long num_pages
;
2078 u64 start
= eb
->start
;
2079 u64 end
= start
+ eb
->len
- 1;
2081 set
= clear_extent_dirty(tree
, start
, end
, GFP_NOFS
);
2082 num_pages
= ((eb
->start
+ eb
->len
- 1) >> PAGE_CACHE_SHIFT
) -
2083 (eb
->start
>> PAGE_CACHE_SHIFT
) + 1;
2085 for (i
= 0; i
< num_pages
; i
++) {
2086 page
= extent_buffer_page(eb
, i
);
2089 * if we're on the last page or the first page and the
2090 * block isn't aligned on a page boundary, do extra checks
2091 * to make sure we don't clean page that is partially dirty
2093 if ((i
== 0 && (eb
->start
& (PAGE_CACHE_SIZE
- 1))) ||
2094 ((i
== num_pages
- 1) &&
2095 ((eb
->start
+ eb
->len
- 1) & (PAGE_CACHE_SIZE
- 1)))) {
2096 start
= page
->index
<< PAGE_CACHE_SHIFT
;
2097 end
= start
+ PAGE_CACHE_SIZE
- 1;
2098 if (test_range_bit(tree
, start
, end
,
2104 clear_page_dirty_for_io(page
);
2109 EXPORT_SYMBOL(clear_extent_buffer_dirty
);
2111 int wait_on_extent_buffer_writeback(struct extent_map_tree
*tree
,
2112 struct extent_buffer
*eb
)
2114 return wait_on_extent_writeback(tree
, eb
->start
,
2115 eb
->start
+ eb
->len
- 1);
2117 EXPORT_SYMBOL(wait_on_extent_buffer_writeback
);
2119 int set_extent_buffer_dirty(struct extent_map_tree
*tree
,
2120 struct extent_buffer
*eb
)
2122 return set_range_dirty(tree
, eb
->start
, eb
->start
+ eb
->len
- 1);
2124 EXPORT_SYMBOL(set_extent_buffer_dirty
);
2126 int set_extent_buffer_uptodate(struct extent_map_tree
*tree
,
2127 struct extent_buffer
*eb
)
2131 unsigned long num_pages
;
2133 num_pages
= ((eb
->start
+ eb
->len
- 1) >> PAGE_CACHE_SHIFT
) -
2134 (eb
->start
>> PAGE_CACHE_SHIFT
) + 1;
2136 set_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
2138 for (i
= 0; i
< num_pages
; i
++) {
2139 page
= extent_buffer_page(eb
, i
);
2140 if ((i
== 0 && (eb
->start
& (PAGE_CACHE_SIZE
- 1))) ||
2141 ((i
== num_pages
- 1) &&
2142 ((eb
->start
+ eb
->len
- 1) & (PAGE_CACHE_SIZE
- 1)))) {
2143 check_page_uptodate(tree
, page
);
2146 SetPageUptodate(page
);
2150 EXPORT_SYMBOL(set_extent_buffer_uptodate
);
2152 int extent_buffer_uptodate(struct extent_map_tree
*tree
,
2153 struct extent_buffer
*eb
)
2155 if (eb
->flags
& EXTENT_UPTODATE
)
2157 return test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
2158 EXTENT_UPTODATE
, 1);
2160 EXPORT_SYMBOL(extent_buffer_uptodate
);
2162 int read_extent_buffer_pages(struct extent_map_tree
*tree
,
2163 struct extent_buffer
*eb
, int wait
)
2169 unsigned long num_pages
;
2171 if (eb
->flags
& EXTENT_UPTODATE
)
2174 if (test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
2175 EXTENT_UPTODATE
, 1)) {
2179 num_pages
= ((eb
->start
+ eb
->len
- 1) >> PAGE_CACHE_SHIFT
) -
2180 (eb
->start
>> PAGE_CACHE_SHIFT
) + 1;
2181 for (i
= 0; i
< num_pages
; i
++) {
2182 page
= extent_buffer_page(eb
, i
);
2183 if (PageUptodate(page
)) {
2187 if (TestSetPageLocked(page
)) {
2193 if (!PageUptodate(page
)) {
2194 err
= page
->mapping
->a_ops
->readpage(NULL
, page
);
2207 for (i
= 0; i
< num_pages
; i
++) {
2208 page
= extent_buffer_page(eb
, i
);
2209 wait_on_page_locked(page
);
2210 if (!PageUptodate(page
)) {
2214 eb
->flags
|= EXTENT_UPTODATE
;
2217 EXPORT_SYMBOL(read_extent_buffer_pages
);
2219 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
2220 unsigned long start
,
2227 char *dst
= (char *)dstv
;
2228 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
2229 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
2231 WARN_ON(start
> eb
->len
);
2232 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
2234 offset
= start
& ((unsigned long)PAGE_CACHE_SIZE
- 1);
2236 offset
+= start_offset
;
2239 page
= extent_buffer_page(eb
, i
);
2240 WARN_ON(!PageUptodate(page
));
2242 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
2243 kaddr
= kmap_atomic(page
, KM_USER0
);
2244 memcpy(dst
, kaddr
+ offset
, cur
);
2245 kunmap_atomic(kaddr
, KM_USER0
);
2253 EXPORT_SYMBOL(read_extent_buffer
);
2255 int map_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
2256 unsigned long min_len
,
2257 char **token
, char **map
,
2258 unsigned long *map_start
,
2259 unsigned long *map_len
, int km
)
2261 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
2263 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
2264 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
2265 unsigned long end_i
= (start_offset
+ start
+ min_len
) >>
2271 WARN_ON(start
> eb
->len
);
2274 offset
= start_offset
;
2277 *map_start
= (i
<< PAGE_CACHE_SHIFT
) - start_offset
;
2280 kaddr
= kmap_atomic(extent_buffer_page(eb
, i
), km
);
2282 *map
= kaddr
+ offset
;
2283 *map_len
= PAGE_CACHE_SIZE
- offset
;
2286 EXPORT_SYMBOL(map_extent_buffer
);
2288 void unmap_extent_buffer(struct extent_buffer
*eb
, char *token
, int km
)
2290 kunmap_atomic(token
, km
);
2292 EXPORT_SYMBOL(unmap_extent_buffer
);
2294 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
2295 unsigned long start
,
2302 char *ptr
= (char *)ptrv
;
2303 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
2304 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
2307 WARN_ON(start
> eb
->len
);
2308 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
2310 offset
= start
& ((unsigned long)PAGE_CACHE_SIZE
- 1);
2312 offset
+= start_offset
;
2315 page
= extent_buffer_page(eb
, i
);
2316 WARN_ON(!PageUptodate(page
));
2318 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
2320 kaddr
= kmap_atomic(page
, KM_USER0
);
2321 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
2322 kunmap_atomic(kaddr
, KM_USER0
);
2333 EXPORT_SYMBOL(memcmp_extent_buffer
);
2335 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
2336 unsigned long start
, unsigned long len
)
2342 char *src
= (char *)srcv
;
2343 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
2344 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
2346 WARN_ON(start
> eb
->len
);
2347 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
2349 offset
= start
& ((unsigned long)PAGE_CACHE_SIZE
- 1);
2351 offset
+= start_offset
;
2354 page
= extent_buffer_page(eb
, i
);
2355 WARN_ON(!PageUptodate(page
));
2357 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
2358 kaddr
= kmap_atomic(page
, KM_USER0
);
2359 memcpy(kaddr
+ offset
, src
, cur
);
2360 kunmap_atomic(kaddr
, KM_USER0
);
2368 EXPORT_SYMBOL(write_extent_buffer
);
2370 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
2371 unsigned long start
, unsigned long len
)
2377 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
2378 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
2380 WARN_ON(start
> eb
->len
);
2381 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
2383 offset
= start
& ((unsigned long)PAGE_CACHE_SIZE
- 1);
2385 offset
+= start_offset
;
2388 page
= extent_buffer_page(eb
, i
);
2389 WARN_ON(!PageUptodate(page
));
2391 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
2392 kaddr
= kmap_atomic(page
, KM_USER0
);
2393 memset(kaddr
+ offset
, c
, cur
);
2394 kunmap_atomic(kaddr
, KM_USER0
);
2401 EXPORT_SYMBOL(memset_extent_buffer
);
2403 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
2404 unsigned long dst_offset
, unsigned long src_offset
,
2407 u64 dst_len
= dst
->len
;
2412 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
2413 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
2415 WARN_ON(src
->len
!= dst_len
);
2417 offset
= dst_offset
& ((unsigned long)PAGE_CACHE_SIZE
- 1);
2419 offset
+= start_offset
;
2422 page
= extent_buffer_page(dst
, i
);
2423 WARN_ON(!PageUptodate(page
));
2425 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
2427 kaddr
= kmap_atomic(page
, KM_USER1
);
2428 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
2429 kunmap_atomic(kaddr
, KM_USER1
);
2437 EXPORT_SYMBOL(copy_extent_buffer
);
2439 static void move_pages(struct page
*dst_page
, struct page
*src_page
,
2440 unsigned long dst_off
, unsigned long src_off
,
2443 char *dst_kaddr
= kmap_atomic(dst_page
, KM_USER0
);
2444 if (dst_page
== src_page
) {
2445 memmove(dst_kaddr
+ dst_off
, dst_kaddr
+ src_off
, len
);
2447 char *src_kaddr
= kmap_atomic(src_page
, KM_USER1
);
2448 char *p
= dst_kaddr
+ dst_off
+ len
;
2449 char *s
= src_kaddr
+ src_off
+ len
;
2454 kunmap_atomic(src_kaddr
, KM_USER1
);
2456 kunmap_atomic(dst_kaddr
, KM_USER0
);
2459 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
2460 unsigned long dst_off
, unsigned long src_off
,
2463 char *dst_kaddr
= kmap_atomic(dst_page
, KM_USER0
);
2466 if (dst_page
!= src_page
)
2467 src_kaddr
= kmap_atomic(src_page
, KM_USER1
);
2469 src_kaddr
= dst_kaddr
;
2471 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
2472 kunmap_atomic(dst_kaddr
, KM_USER0
);
2473 if (dst_page
!= src_page
)
2474 kunmap_atomic(src_kaddr
, KM_USER1
);
2477 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
2478 unsigned long src_offset
, unsigned long len
)
2481 size_t dst_off_in_page
;
2482 size_t src_off_in_page
;
2483 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
2484 unsigned long dst_i
;
2485 unsigned long src_i
;
2487 if (src_offset
+ len
> dst
->len
) {
2488 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
2489 src_offset
, len
, dst
->len
);
2492 if (dst_offset
+ len
> dst
->len
) {
2493 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
2494 dst_offset
, len
, dst
->len
);
2499 dst_off_in_page
= dst_offset
&
2500 ((unsigned long)PAGE_CACHE_SIZE
- 1);
2501 src_off_in_page
= src_offset
&
2502 ((unsigned long)PAGE_CACHE_SIZE
- 1);
2504 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
2505 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
2508 src_off_in_page
+= start_offset
;
2510 dst_off_in_page
+= start_offset
;
2512 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
2514 cur
= min(cur
, (unsigned long)(PAGE_CACHE_SIZE
-
2517 copy_pages(extent_buffer_page(dst
, dst_i
),
2518 extent_buffer_page(dst
, src_i
),
2519 dst_off_in_page
, src_off_in_page
, cur
);
2526 EXPORT_SYMBOL(memcpy_extent_buffer
);
2528 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
2529 unsigned long src_offset
, unsigned long len
)
2532 size_t dst_off_in_page
;
2533 size_t src_off_in_page
;
2534 unsigned long dst_end
= dst_offset
+ len
- 1;
2535 unsigned long src_end
= src_offset
+ len
- 1;
2536 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
2537 unsigned long dst_i
;
2538 unsigned long src_i
;
2540 if (src_offset
+ len
> dst
->len
) {
2541 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
2542 src_offset
, len
, dst
->len
);
2545 if (dst_offset
+ len
> dst
->len
) {
2546 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
2547 dst_offset
, len
, dst
->len
);
2550 if (dst_offset
< src_offset
) {
2551 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
2555 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
2556 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
2558 dst_off_in_page
= dst_end
&
2559 ((unsigned long)PAGE_CACHE_SIZE
- 1);
2560 src_off_in_page
= src_end
&
2561 ((unsigned long)PAGE_CACHE_SIZE
- 1);
2564 src_off_in_page
+= start_offset
;
2566 dst_off_in_page
+= start_offset
;
2568 cur
= min(len
, src_off_in_page
+ 1);
2569 cur
= min(cur
, dst_off_in_page
+ 1);
2571 move_pages(extent_buffer_page(dst
, dst_i
),
2572 extent_buffer_page(dst
, src_i
),
2573 dst_off_in_page
- cur
+ 1,
2574 src_off_in_page
- cur
+ 1, cur
);
2581 EXPORT_SYMBOL(memmove_extent_buffer
);