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 <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"
18 /* temporary define until extent_map moves out of btrfs */
19 struct kmem_cache
*btrfs_cache_create(const char *name
, size_t size
,
20 unsigned long extra_flags
,
21 void (*ctor
)(void *, struct kmem_cache
*,
24 static struct kmem_cache
*extent_state_cache
;
25 static struct kmem_cache
*extent_buffer_cache
;
27 static LIST_HEAD(buffers
);
28 static LIST_HEAD(states
);
29 static spinlock_t leak_lock
= SPIN_LOCK_UNLOCKED
;
31 #define BUFFER_LRU_MAX 64
36 struct rb_node rb_node
;
39 struct extent_page_data
{
41 struct extent_io_tree
*tree
;
42 get_extent_t
*get_extent
;
45 int __init
extent_io_init(void)
47 extent_state_cache
= btrfs_cache_create("extent_state",
48 sizeof(struct extent_state
), 0,
50 if (!extent_state_cache
)
53 extent_buffer_cache
= btrfs_cache_create("extent_buffers",
54 sizeof(struct extent_buffer
), 0,
56 if (!extent_buffer_cache
)
57 goto free_state_cache
;
61 kmem_cache_destroy(extent_state_cache
);
65 void extent_io_exit(void)
67 struct extent_state
*state
;
68 struct extent_buffer
*eb
;
70 while (!list_empty(&states
)) {
71 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
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
));
73 list_del(&state
->leak_list
);
74 kmem_cache_free(extent_state_cache
, state
);
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
);
84 if (extent_state_cache
)
85 kmem_cache_destroy(extent_state_cache
);
86 if (extent_buffer_cache
)
87 kmem_cache_destroy(extent_buffer_cache
);
90 void extent_io_tree_init(struct extent_io_tree
*tree
,
91 struct address_space
*mapping
, gfp_t mask
)
93 tree
->state
.rb_node
= NULL
;
94 tree
->buffer
.rb_node
= NULL
;
96 tree
->dirty_bytes
= 0;
97 spin_lock_init(&tree
->lock
);
98 spin_lock_init(&tree
->buffer_lock
);
99 tree
->mapping
= mapping
;
101 EXPORT_SYMBOL(extent_io_tree_init
);
103 struct extent_state
*alloc_extent_state(gfp_t mask
)
105 struct extent_state
*state
;
108 state
= kmem_cache_alloc(extent_state_cache
, mask
);
114 spin_lock_irqsave(&leak_lock
, flags
);
115 list_add(&state
->leak_list
, &states
);
116 spin_unlock_irqrestore(&leak_lock
, flags
);
118 atomic_set(&state
->refs
, 1);
119 init_waitqueue_head(&state
->wq
);
122 EXPORT_SYMBOL(alloc_extent_state
);
124 void free_extent_state(struct extent_state
*state
)
128 if (atomic_dec_and_test(&state
->refs
)) {
130 WARN_ON(state
->tree
);
131 spin_lock_irqsave(&leak_lock
, flags
);
132 list_del(&state
->leak_list
);
133 spin_unlock_irqrestore(&leak_lock
, flags
);
134 kmem_cache_free(extent_state_cache
, state
);
137 EXPORT_SYMBOL(free_extent_state
);
139 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
140 struct rb_node
*node
)
142 struct rb_node
** p
= &root
->rb_node
;
143 struct rb_node
* parent
= NULL
;
144 struct tree_entry
*entry
;
148 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
150 if (offset
< entry
->start
)
152 else if (offset
> entry
->end
)
158 entry
= rb_entry(node
, struct tree_entry
, rb_node
);
159 rb_link_node(node
, parent
, p
);
160 rb_insert_color(node
, root
);
164 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
165 struct rb_node
**prev_ret
,
166 struct rb_node
**next_ret
)
168 struct rb_root
*root
= &tree
->state
;
169 struct rb_node
* n
= root
->rb_node
;
170 struct rb_node
*prev
= NULL
;
171 struct rb_node
*orig_prev
= NULL
;
172 struct tree_entry
*entry
;
173 struct tree_entry
*prev_entry
= NULL
;
176 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
180 if (offset
< entry
->start
)
182 else if (offset
> entry
->end
)
191 while(prev
&& offset
> prev_entry
->end
) {
192 prev
= rb_next(prev
);
193 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
200 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
201 while(prev
&& offset
< prev_entry
->start
) {
202 prev
= rb_prev(prev
);
203 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
210 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
213 struct rb_node
*prev
= NULL
;
216 ret
= __etree_search(tree
, offset
, &prev
, NULL
);
223 static struct extent_buffer
*buffer_tree_insert(struct extent_io_tree
*tree
,
224 u64 offset
, struct rb_node
*node
)
226 struct rb_root
*root
= &tree
->buffer
;
227 struct rb_node
** p
= &root
->rb_node
;
228 struct rb_node
* parent
= NULL
;
229 struct extent_buffer
*eb
;
233 eb
= rb_entry(parent
, struct extent_buffer
, rb_node
);
235 if (offset
< eb
->start
)
237 else if (offset
> eb
->start
)
243 rb_link_node(node
, parent
, p
);
244 rb_insert_color(node
, root
);
248 static struct extent_buffer
*buffer_search(struct extent_io_tree
*tree
,
251 struct rb_root
*root
= &tree
->buffer
;
252 struct rb_node
* n
= root
->rb_node
;
253 struct extent_buffer
*eb
;
256 eb
= rb_entry(n
, struct extent_buffer
, rb_node
);
257 if (offset
< eb
->start
)
259 else if (offset
> eb
->start
)
268 * utility function to look for merge candidates inside a given range.
269 * Any extents with matching state are merged together into a single
270 * extent in the tree. Extents with EXTENT_IO in their state field
271 * are not merged because the end_io handlers need to be able to do
272 * operations on them without sleeping (or doing allocations/splits).
274 * This should be called with the tree lock held.
276 static int merge_state(struct extent_io_tree
*tree
,
277 struct extent_state
*state
)
279 struct extent_state
*other
;
280 struct rb_node
*other_node
;
282 if (state
->state
& EXTENT_IOBITS
)
285 other_node
= rb_prev(&state
->rb_node
);
287 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
288 if (other
->end
== state
->start
- 1 &&
289 other
->state
== state
->state
) {
290 state
->start
= other
->start
;
292 rb_erase(&other
->rb_node
, &tree
->state
);
293 free_extent_state(other
);
296 other_node
= rb_next(&state
->rb_node
);
298 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
299 if (other
->start
== state
->end
+ 1 &&
300 other
->state
== state
->state
) {
301 other
->start
= state
->start
;
303 rb_erase(&state
->rb_node
, &tree
->state
);
304 free_extent_state(state
);
310 static void set_state_cb(struct extent_io_tree
*tree
,
311 struct extent_state
*state
,
314 if (tree
->ops
&& tree
->ops
->set_bit_hook
) {
315 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
->start
,
316 state
->end
, state
->state
, bits
);
320 static void clear_state_cb(struct extent_io_tree
*tree
,
321 struct extent_state
*state
,
324 if (tree
->ops
&& tree
->ops
->set_bit_hook
) {
325 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
->start
,
326 state
->end
, state
->state
, bits
);
331 * insert an extent_state struct into the tree. 'bits' are set on the
332 * struct before it is inserted.
334 * This may return -EEXIST if the extent is already there, in which case the
335 * state struct is freed.
337 * The tree lock is not taken internally. This is a utility function and
338 * probably isn't what you want to call (see set/clear_extent_bit).
340 static int insert_state(struct extent_io_tree
*tree
,
341 struct extent_state
*state
, u64 start
, u64 end
,
344 struct rb_node
*node
;
347 printk("end < start %Lu %Lu\n", end
, start
);
350 if (bits
& EXTENT_DIRTY
)
351 tree
->dirty_bytes
+= end
- start
+ 1;
352 set_state_cb(tree
, state
, bits
);
353 state
->state
|= bits
;
354 state
->start
= start
;
356 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
358 struct extent_state
*found
;
359 found
= rb_entry(node
, struct extent_state
, rb_node
);
360 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found
->start
, found
->end
, start
, end
);
361 free_extent_state(state
);
365 merge_state(tree
, state
);
370 * split a given extent state struct in two, inserting the preallocated
371 * struct 'prealloc' as the newly created second half. 'split' indicates an
372 * offset inside 'orig' where it should be split.
375 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
376 * are two extent state structs in the tree:
377 * prealloc: [orig->start, split - 1]
378 * orig: [ split, orig->end ]
380 * The tree locks are not taken by this function. They need to be held
383 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
384 struct extent_state
*prealloc
, u64 split
)
386 struct rb_node
*node
;
387 prealloc
->start
= orig
->start
;
388 prealloc
->end
= split
- 1;
389 prealloc
->state
= orig
->state
;
392 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
394 struct extent_state
*found
;
395 found
= rb_entry(node
, struct extent_state
, rb_node
);
396 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found
->start
, found
->end
, prealloc
->start
, prealloc
->end
);
397 free_extent_state(prealloc
);
400 prealloc
->tree
= tree
;
405 * utility function to clear some bits in an extent state struct.
406 * it will optionally wake up any one waiting on this state (wake == 1), or
407 * forcibly remove the state from the tree (delete == 1).
409 * If no bits are set on the state struct after clearing things, the
410 * struct is freed and removed from the tree
412 static int clear_state_bit(struct extent_io_tree
*tree
,
413 struct extent_state
*state
, int bits
, int wake
,
416 int ret
= state
->state
& bits
;
418 if ((bits
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
419 u64 range
= state
->end
- state
->start
+ 1;
420 WARN_ON(range
> tree
->dirty_bytes
);
421 tree
->dirty_bytes
-= range
;
423 clear_state_cb(tree
, state
, bits
);
424 state
->state
&= ~bits
;
427 if (delete || state
->state
== 0) {
429 clear_state_cb(tree
, state
, state
->state
);
430 rb_erase(&state
->rb_node
, &tree
->state
);
432 free_extent_state(state
);
437 merge_state(tree
, state
);
443 * clear some bits on a range in the tree. This may require splitting
444 * or inserting elements in the tree, so the gfp mask is used to
445 * indicate which allocations or sleeping are allowed.
447 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
448 * the given range from the tree regardless of state (ie for truncate).
450 * the range [start, end] is inclusive.
452 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
453 * bits were already set, or zero if none of the bits were already set.
455 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
456 int bits
, int wake
, int delete, gfp_t mask
)
458 struct extent_state
*state
;
459 struct extent_state
*prealloc
= NULL
;
460 struct rb_node
*node
;
466 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
467 prealloc
= alloc_extent_state(mask
);
472 spin_lock_irqsave(&tree
->lock
, flags
);
474 * this search will find the extents that end after
477 node
= tree_search(tree
, start
);
480 state
= rb_entry(node
, struct extent_state
, rb_node
);
481 if (state
->start
> end
)
483 WARN_ON(state
->end
< start
);
486 * | ---- desired range ---- |
488 * | ------------- state -------------- |
490 * We need to split the extent we found, and may flip
491 * bits on second half.
493 * If the extent we found extends past our range, we
494 * just split and search again. It'll get split again
495 * the next time though.
497 * If the extent we found is inside our range, we clear
498 * the desired bit on it.
501 if (state
->start
< start
) {
503 prealloc
= alloc_extent_state(GFP_ATOMIC
);
504 err
= split_state(tree
, state
, prealloc
, start
);
505 BUG_ON(err
== -EEXIST
);
509 if (state
->end
<= end
) {
510 start
= state
->end
+ 1;
511 set
|= clear_state_bit(tree
, state
, bits
,
514 start
= state
->start
;
519 * | ---- desired range ---- |
521 * We need to split the extent, and clear the bit
524 if (state
->start
<= end
&& state
->end
> end
) {
526 prealloc
= alloc_extent_state(GFP_ATOMIC
);
527 err
= split_state(tree
, state
, prealloc
, end
+ 1);
528 BUG_ON(err
== -EEXIST
);
532 set
|= clear_state_bit(tree
, prealloc
, bits
,
538 start
= state
->end
+ 1;
539 set
|= clear_state_bit(tree
, state
, bits
, wake
, delete);
543 spin_unlock_irqrestore(&tree
->lock
, flags
);
545 free_extent_state(prealloc
);
552 spin_unlock_irqrestore(&tree
->lock
, flags
);
553 if (mask
& __GFP_WAIT
)
557 EXPORT_SYMBOL(clear_extent_bit
);
559 static int wait_on_state(struct extent_io_tree
*tree
,
560 struct extent_state
*state
)
563 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
564 spin_unlock_irq(&tree
->lock
);
566 spin_lock_irq(&tree
->lock
);
567 finish_wait(&state
->wq
, &wait
);
572 * waits for one or more bits to clear on a range in the state tree.
573 * The range [start, end] is inclusive.
574 * The tree lock is taken by this function
576 int wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
, int bits
)
578 struct extent_state
*state
;
579 struct rb_node
*node
;
581 spin_lock_irq(&tree
->lock
);
585 * this search will find all the extents that end after
588 node
= tree_search(tree
, start
);
592 state
= rb_entry(node
, struct extent_state
, rb_node
);
594 if (state
->start
> end
)
597 if (state
->state
& bits
) {
598 start
= state
->start
;
599 atomic_inc(&state
->refs
);
600 wait_on_state(tree
, state
);
601 free_extent_state(state
);
604 start
= state
->end
+ 1;
609 if (need_resched()) {
610 spin_unlock_irq(&tree
->lock
);
612 spin_lock_irq(&tree
->lock
);
616 spin_unlock_irq(&tree
->lock
);
619 EXPORT_SYMBOL(wait_extent_bit
);
621 static void set_state_bits(struct extent_io_tree
*tree
,
622 struct extent_state
*state
,
625 if ((bits
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
626 u64 range
= state
->end
- state
->start
+ 1;
627 tree
->dirty_bytes
+= range
;
629 set_state_cb(tree
, state
, bits
);
630 state
->state
|= bits
;
634 * set some bits on a range in the tree. This may require allocations
635 * or sleeping, so the gfp mask is used to indicate what is allowed.
637 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
638 * range already has the desired bits set. The start of the existing
639 * range is returned in failed_start in this case.
641 * [start, end] is inclusive
642 * This takes the tree lock.
644 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
, int bits
,
645 int exclusive
, u64
*failed_start
, gfp_t mask
)
647 struct extent_state
*state
;
648 struct extent_state
*prealloc
= NULL
;
649 struct rb_node
*node
;
656 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
657 prealloc
= alloc_extent_state(mask
);
662 spin_lock_irqsave(&tree
->lock
, flags
);
664 * this search will find all the extents that end after
667 node
= tree_search(tree
, start
);
669 err
= insert_state(tree
, prealloc
, start
, end
, bits
);
671 BUG_ON(err
== -EEXIST
);
675 state
= rb_entry(node
, struct extent_state
, rb_node
);
676 last_start
= state
->start
;
677 last_end
= state
->end
;
680 * | ---- desired range ---- |
683 * Just lock what we found and keep going
685 if (state
->start
== start
&& state
->end
<= end
) {
686 set
= state
->state
& bits
;
687 if (set
&& exclusive
) {
688 *failed_start
= state
->start
;
692 set_state_bits(tree
, state
, bits
);
693 start
= state
->end
+ 1;
694 merge_state(tree
, state
);
699 * | ---- desired range ---- |
702 * | ------------- state -------------- |
704 * We need to split the extent we found, and may flip bits on
707 * If the extent we found extends past our
708 * range, we just split and search again. It'll get split
709 * again the next time though.
711 * If the extent we found is inside our range, we set the
714 if (state
->start
< start
) {
715 set
= state
->state
& bits
;
716 if (exclusive
&& set
) {
717 *failed_start
= start
;
721 err
= split_state(tree
, state
, prealloc
, start
);
722 BUG_ON(err
== -EEXIST
);
726 if (state
->end
<= end
) {
727 set_state_bits(tree
, state
, bits
);
728 start
= state
->end
+ 1;
729 merge_state(tree
, state
);
731 start
= state
->start
;
736 * | ---- desired range ---- |
737 * | state | or | state |
739 * There's a hole, we need to insert something in it and
740 * ignore the extent we found.
742 if (state
->start
> start
) {
744 if (end
< last_start
)
747 this_end
= last_start
-1;
748 err
= insert_state(tree
, prealloc
, start
, this_end
,
751 BUG_ON(err
== -EEXIST
);
754 start
= this_end
+ 1;
758 * | ---- desired range ---- |
760 * We need to split the extent, and set the bit
763 if (state
->start
<= end
&& state
->end
> end
) {
764 set
= state
->state
& bits
;
765 if (exclusive
&& set
) {
766 *failed_start
= start
;
770 err
= split_state(tree
, state
, prealloc
, end
+ 1);
771 BUG_ON(err
== -EEXIST
);
773 set_state_bits(tree
, prealloc
, bits
);
774 merge_state(tree
, prealloc
);
782 spin_unlock_irqrestore(&tree
->lock
, flags
);
784 free_extent_state(prealloc
);
791 spin_unlock_irqrestore(&tree
->lock
, flags
);
792 if (mask
& __GFP_WAIT
)
796 EXPORT_SYMBOL(set_extent_bit
);
798 /* wrappers around set/clear extent bit */
799 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
802 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, 0, NULL
,
805 EXPORT_SYMBOL(set_extent_dirty
);
807 int set_extent_ordered(struct extent_io_tree
*tree
, u64 start
, u64 end
,
810 return set_extent_bit(tree
, start
, end
, EXTENT_ORDERED
, 0, NULL
, mask
);
812 EXPORT_SYMBOL(set_extent_ordered
);
814 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
815 int bits
, gfp_t mask
)
817 return set_extent_bit(tree
, start
, end
, bits
, 0, NULL
,
820 EXPORT_SYMBOL(set_extent_bits
);
822 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
823 int bits
, gfp_t mask
)
825 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, mask
);
827 EXPORT_SYMBOL(clear_extent_bits
);
829 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
832 return set_extent_bit(tree
, start
, end
,
833 EXTENT_DELALLOC
| EXTENT_DIRTY
,
836 EXPORT_SYMBOL(set_extent_delalloc
);
838 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
841 return clear_extent_bit(tree
, start
, end
,
842 EXTENT_DIRTY
| EXTENT_DELALLOC
, 0, 0, mask
);
844 EXPORT_SYMBOL(clear_extent_dirty
);
846 int clear_extent_ordered(struct extent_io_tree
*tree
, u64 start
, u64 end
,
849 return clear_extent_bit(tree
, start
, end
, EXTENT_ORDERED
, 1, 0, mask
);
851 EXPORT_SYMBOL(clear_extent_ordered
);
853 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
856 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, NULL
,
859 EXPORT_SYMBOL(set_extent_new
);
861 int clear_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
864 return clear_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, 0, mask
);
866 EXPORT_SYMBOL(clear_extent_new
);
868 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
871 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, NULL
,
874 EXPORT_SYMBOL(set_extent_uptodate
);
876 int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
879 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0, mask
);
881 EXPORT_SYMBOL(clear_extent_uptodate
);
883 int set_extent_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
,
886 return set_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
,
889 EXPORT_SYMBOL(set_extent_writeback
);
891 int clear_extent_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
,
894 return clear_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
, 1, 0, mask
);
896 EXPORT_SYMBOL(clear_extent_writeback
);
898 int wait_on_extent_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
900 return wait_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
);
902 EXPORT_SYMBOL(wait_on_extent_writeback
);
904 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
, gfp_t mask
)
909 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1,
910 &failed_start
, mask
);
911 if (err
== -EEXIST
&& (mask
& __GFP_WAIT
)) {
912 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
913 start
= failed_start
;
917 WARN_ON(start
> end
);
921 EXPORT_SYMBOL(lock_extent
);
923 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
,
926 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, mask
);
928 EXPORT_SYMBOL(unlock_extent
);
931 * helper function to set pages and extents in the tree dirty
933 int set_range_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
)
935 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
936 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
939 while (index
<= end_index
) {
940 page
= find_get_page(tree
->mapping
, index
);
942 __set_page_dirty_nobuffers(page
);
943 page_cache_release(page
);
946 set_extent_dirty(tree
, start
, end
, GFP_NOFS
);
949 EXPORT_SYMBOL(set_range_dirty
);
952 * helper function to set both pages and extents in the tree writeback
954 int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
956 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
957 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
960 while (index
<= end_index
) {
961 page
= find_get_page(tree
->mapping
, index
);
963 set_page_writeback(page
);
964 page_cache_release(page
);
967 set_extent_writeback(tree
, start
, end
, GFP_NOFS
);
970 EXPORT_SYMBOL(set_range_writeback
);
972 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
973 u64
*start_ret
, u64
*end_ret
, int bits
)
975 struct rb_node
*node
;
976 struct extent_state
*state
;
979 spin_lock_irq(&tree
->lock
);
981 * this search will find all the extents that end after
984 node
= tree_search(tree
, start
);
990 state
= rb_entry(node
, struct extent_state
, rb_node
);
991 if (state
->end
>= start
&& (state
->state
& bits
)) {
992 *start_ret
= state
->start
;
993 *end_ret
= state
->end
;
997 node
= rb_next(node
);
1002 spin_unlock_irq(&tree
->lock
);
1005 EXPORT_SYMBOL(find_first_extent_bit
);
1007 struct extent_state
*find_first_extent_bit_state(struct extent_io_tree
*tree
,
1008 u64 start
, int bits
)
1010 struct rb_node
*node
;
1011 struct extent_state
*state
;
1014 * this search will find all the extents that end after
1017 node
= tree_search(tree
, start
);
1023 state
= rb_entry(node
, struct extent_state
, rb_node
);
1024 if (state
->end
>= start
&& (state
->state
& bits
)) {
1027 node
= rb_next(node
);
1034 EXPORT_SYMBOL(find_first_extent_bit_state
);
1036 u64
find_lock_delalloc_range(struct extent_io_tree
*tree
,
1037 u64
*start
, u64
*end
, u64 max_bytes
)
1039 struct rb_node
*node
;
1040 struct extent_state
*state
;
1041 u64 cur_start
= *start
;
1043 u64 total_bytes
= 0;
1045 spin_lock_irq(&tree
->lock
);
1047 * this search will find all the extents that end after
1051 node
= tree_search(tree
, cur_start
);
1059 state
= rb_entry(node
, struct extent_state
, rb_node
);
1060 if (found
&& state
->start
!= cur_start
) {
1063 if (!(state
->state
& EXTENT_DELALLOC
)) {
1069 struct extent_state
*prev_state
;
1070 struct rb_node
*prev_node
= node
;
1072 prev_node
= rb_prev(prev_node
);
1075 prev_state
= rb_entry(prev_node
,
1076 struct extent_state
,
1078 if (!(prev_state
->state
& EXTENT_DELALLOC
))
1084 if (state
->state
& EXTENT_LOCKED
) {
1086 atomic_inc(&state
->refs
);
1087 prepare_to_wait(&state
->wq
, &wait
,
1088 TASK_UNINTERRUPTIBLE
);
1089 spin_unlock_irq(&tree
->lock
);
1091 spin_lock_irq(&tree
->lock
);
1092 finish_wait(&state
->wq
, &wait
);
1093 free_extent_state(state
);
1096 set_state_cb(tree
, state
, EXTENT_LOCKED
);
1097 state
->state
|= EXTENT_LOCKED
;
1099 *start
= state
->start
;
1102 cur_start
= state
->end
+ 1;
1103 node
= rb_next(node
);
1106 total_bytes
+= state
->end
- state
->start
+ 1;
1107 if (total_bytes
>= max_bytes
)
1111 spin_unlock_irq(&tree
->lock
);
1115 u64
count_range_bits(struct extent_io_tree
*tree
,
1116 u64
*start
, u64 search_end
, u64 max_bytes
,
1119 struct rb_node
*node
;
1120 struct extent_state
*state
;
1121 u64 cur_start
= *start
;
1122 u64 total_bytes
= 0;
1125 if (search_end
<= cur_start
) {
1126 printk("search_end %Lu start %Lu\n", search_end
, cur_start
);
1131 spin_lock_irq(&tree
->lock
);
1132 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1133 total_bytes
= tree
->dirty_bytes
;
1137 * this search will find all the extents that end after
1140 node
= tree_search(tree
, cur_start
);
1146 state
= rb_entry(node
, struct extent_state
, rb_node
);
1147 if (state
->start
> search_end
)
1149 if (state
->end
>= cur_start
&& (state
->state
& bits
)) {
1150 total_bytes
+= min(search_end
, state
->end
) + 1 -
1151 max(cur_start
, state
->start
);
1152 if (total_bytes
>= max_bytes
)
1155 *start
= state
->start
;
1159 node
= rb_next(node
);
1164 spin_unlock_irq(&tree
->lock
);
1168 * helper function to lock both pages and extents in the tree.
1169 * pages must be locked first.
1171 int lock_range(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1173 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1174 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1178 while (index
<= end_index
) {
1179 page
= grab_cache_page(tree
->mapping
, index
);
1185 err
= PTR_ERR(page
);
1190 lock_extent(tree
, start
, end
, GFP_NOFS
);
1195 * we failed above in getting the page at 'index', so we undo here
1196 * up to but not including the page at 'index'
1199 index
= start
>> PAGE_CACHE_SHIFT
;
1200 while (index
< end_index
) {
1201 page
= find_get_page(tree
->mapping
, index
);
1203 page_cache_release(page
);
1208 EXPORT_SYMBOL(lock_range
);
1211 * helper function to unlock both pages and extents in the tree.
1213 int unlock_range(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1215 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1216 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1219 while (index
<= end_index
) {
1220 page
= find_get_page(tree
->mapping
, index
);
1222 page_cache_release(page
);
1225 unlock_extent(tree
, start
, end
, GFP_NOFS
);
1228 EXPORT_SYMBOL(unlock_range
);
1230 int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1232 struct rb_node
*node
;
1233 struct extent_state
*state
;
1236 spin_lock_irq(&tree
->lock
);
1238 * this search will find all the extents that end after
1241 node
= tree_search(tree
, start
);
1246 state
= rb_entry(node
, struct extent_state
, rb_node
);
1247 if (state
->start
!= start
) {
1251 state
->private = private;
1253 spin_unlock_irq(&tree
->lock
);
1257 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1259 struct rb_node
*node
;
1260 struct extent_state
*state
;
1263 spin_lock_irq(&tree
->lock
);
1265 * this search will find all the extents that end after
1268 node
= tree_search(tree
, start
);
1273 state
= rb_entry(node
, struct extent_state
, rb_node
);
1274 if (state
->start
!= start
) {
1278 *private = state
->private;
1280 spin_unlock_irq(&tree
->lock
);
1285 * searches a range in the state tree for a given mask.
1286 * If 'filled' == 1, this returns 1 only if every extent in the tree
1287 * has the bits set. Otherwise, 1 is returned if any bit in the
1288 * range is found set.
1290 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1291 int bits
, int filled
)
1293 struct extent_state
*state
= NULL
;
1294 struct rb_node
*node
;
1296 unsigned long flags
;
1298 spin_lock_irqsave(&tree
->lock
, flags
);
1299 node
= tree_search(tree
, start
);
1300 while (node
&& start
<= end
) {
1301 state
= rb_entry(node
, struct extent_state
, rb_node
);
1303 if (filled
&& state
->start
> start
) {
1308 if (state
->start
> end
)
1311 if (state
->state
& bits
) {
1315 } else if (filled
) {
1319 start
= state
->end
+ 1;
1322 node
= rb_next(node
);
1329 spin_unlock_irqrestore(&tree
->lock
, flags
);
1332 EXPORT_SYMBOL(test_range_bit
);
1335 * helper function to set a given page up to date if all the
1336 * extents in the tree for that page are up to date
1338 static int check_page_uptodate(struct extent_io_tree
*tree
,
1341 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1342 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1343 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1))
1344 SetPageUptodate(page
);
1349 * helper function to unlock a page if all the extents in the tree
1350 * for that page are unlocked
1352 static int check_page_locked(struct extent_io_tree
*tree
,
1355 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1356 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1357 if (!test_range_bit(tree
, start
, end
, EXTENT_LOCKED
, 0))
1363 * helper function to end page writeback if all the extents
1364 * in the tree for that page are done with writeback
1366 static int check_page_writeback(struct extent_io_tree
*tree
,
1369 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1370 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1371 if (!test_range_bit(tree
, start
, end
, EXTENT_WRITEBACK
, 0))
1372 end_page_writeback(page
);
1376 /* lots and lots of room for performance fixes in the end_bio funcs */
1379 * after a writepage IO is done, we need to:
1380 * clear the uptodate bits on error
1381 * clear the writeback bits in the extent tree for this IO
1382 * end_page_writeback if the page has no more pending IO
1384 * Scheduling is not allowed, so the extent state tree is expected
1385 * to have one and only one object corresponding to this IO.
1387 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1388 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
1390 static int end_bio_extent_writepage(struct bio
*bio
,
1391 unsigned int bytes_done
, int err
)
1394 int uptodate
= err
== 0;
1395 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1396 struct extent_state
*state
= bio
->bi_private
;
1397 struct extent_io_tree
*tree
= state
->tree
;
1398 struct rb_node
*node
;
1404 unsigned long flags
;
1406 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1411 struct page
*page
= bvec
->bv_page
;
1412 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1414 end
= start
+ bvec
->bv_len
- 1;
1416 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1421 if (--bvec
>= bio
->bi_io_vec
)
1422 prefetchw(&bvec
->bv_page
->flags
);
1423 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
1424 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
1425 end
, state
, uptodate
);
1430 if (!uptodate
&& tree
->ops
&&
1431 tree
->ops
->writepage_io_failed_hook
) {
1432 ret
= tree
->ops
->writepage_io_failed_hook(bio
, page
,
1436 uptodate
= (err
== 0);
1442 clear_extent_uptodate(tree
, start
, end
, GFP_ATOMIC
);
1443 ClearPageUptodate(page
);
1448 * bios can get merged in funny ways, and so we need to
1449 * be careful with the state variable. We know the
1450 * state won't be merged with others because it has
1451 * WRITEBACK set, but we can't be sure each biovec is
1452 * sequential in the file. So, if our cached state
1453 * doesn't match the expected end, search the tree
1454 * for the correct one.
1457 spin_lock_irqsave(&tree
->lock
, flags
);
1458 if (!state
|| state
->end
!= end
) {
1460 node
= __etree_search(tree
, start
, NULL
, NULL
);
1462 state
= rb_entry(node
, struct extent_state
,
1464 if (state
->end
!= end
||
1465 !(state
->state
& EXTENT_WRITEBACK
))
1469 spin_unlock_irqrestore(&tree
->lock
, flags
);
1470 clear_extent_writeback(tree
, start
,
1477 struct extent_state
*clear
= state
;
1479 node
= rb_prev(&state
->rb_node
);
1481 state
= rb_entry(node
,
1482 struct extent_state
,
1488 clear_state_bit(tree
, clear
, EXTENT_WRITEBACK
,
1499 /* before releasing the lock, make sure the next state
1500 * variable has the expected bits set and corresponds
1501 * to the correct offsets in the file
1503 if (state
&& (state
->end
+ 1 != start
||
1504 !(state
->state
& EXTENT_WRITEBACK
))) {
1507 spin_unlock_irqrestore(&tree
->lock
, flags
);
1511 end_page_writeback(page
);
1513 check_page_writeback(tree
, page
);
1514 } while (bvec
>= bio
->bi_io_vec
);
1516 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1522 * after a readpage IO is done, we need to:
1523 * clear the uptodate bits on error
1524 * set the uptodate bits if things worked
1525 * set the page up to date if all extents in the tree are uptodate
1526 * clear the lock bit in the extent tree
1527 * unlock the page if there are no other extents locked for it
1529 * Scheduling is not allowed, so the extent state tree is expected
1530 * to have one and only one object corresponding to this IO.
1532 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1533 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
1535 static int end_bio_extent_readpage(struct bio
*bio
,
1536 unsigned int bytes_done
, int err
)
1539 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1540 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1541 struct extent_state
*state
= bio
->bi_private
;
1542 struct extent_io_tree
*tree
= state
->tree
;
1543 struct rb_node
*node
;
1547 unsigned long flags
;
1551 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1557 struct page
*page
= bvec
->bv_page
;
1558 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1560 end
= start
+ bvec
->bv_len
- 1;
1562 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1567 if (--bvec
>= bio
->bi_io_vec
)
1568 prefetchw(&bvec
->bv_page
->flags
);
1570 if (uptodate
&& tree
->ops
&& tree
->ops
->readpage_end_io_hook
) {
1571 ret
= tree
->ops
->readpage_end_io_hook(page
, start
, end
,
1576 if (!uptodate
&& tree
->ops
&&
1577 tree
->ops
->readpage_io_failed_hook
) {
1578 ret
= tree
->ops
->readpage_io_failed_hook(bio
, page
,
1583 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1588 spin_lock_irqsave(&tree
->lock
, flags
);
1589 if (!state
|| state
->end
!= end
) {
1591 node
= __etree_search(tree
, start
, NULL
, NULL
);
1593 state
= rb_entry(node
, struct extent_state
,
1595 if (state
->end
!= end
||
1596 !(state
->state
& EXTENT_LOCKED
))
1600 spin_unlock_irqrestore(&tree
->lock
, flags
);
1602 set_extent_uptodate(tree
, start
, end
,
1604 unlock_extent(tree
, start
, end
, GFP_ATOMIC
);
1611 struct extent_state
*clear
= state
;
1613 node
= rb_prev(&state
->rb_node
);
1615 state
= rb_entry(node
,
1616 struct extent_state
,
1622 set_state_cb(tree
, clear
, EXTENT_UPTODATE
);
1623 clear
->state
|= EXTENT_UPTODATE
;
1625 clear_state_bit(tree
, clear
, EXTENT_LOCKED
,
1636 /* before releasing the lock, make sure the next state
1637 * variable has the expected bits set and corresponds
1638 * to the correct offsets in the file
1640 if (state
&& (state
->end
+ 1 != start
||
1641 !(state
->state
& EXTENT_LOCKED
))) {
1644 spin_unlock_irqrestore(&tree
->lock
, flags
);
1648 SetPageUptodate(page
);
1650 ClearPageUptodate(page
);
1656 check_page_uptodate(tree
, page
);
1658 ClearPageUptodate(page
);
1661 check_page_locked(tree
, page
);
1663 } while (bvec
>= bio
->bi_io_vec
);
1666 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1672 * IO done from prepare_write is pretty simple, we just unlock
1673 * the structs in the extent tree when done, and set the uptodate bits
1676 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1677 static void end_bio_extent_preparewrite(struct bio
*bio
, int err
)
1679 static int end_bio_extent_preparewrite(struct bio
*bio
,
1680 unsigned int bytes_done
, int err
)
1683 const int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1684 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1685 struct extent_state
*state
= bio
->bi_private
;
1686 struct extent_io_tree
*tree
= state
->tree
;
1690 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1696 struct page
*page
= bvec
->bv_page
;
1697 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1699 end
= start
+ bvec
->bv_len
- 1;
1701 if (--bvec
>= bio
->bi_io_vec
)
1702 prefetchw(&bvec
->bv_page
->flags
);
1705 set_extent_uptodate(tree
, start
, end
, GFP_ATOMIC
);
1707 ClearPageUptodate(page
);
1711 unlock_extent(tree
, start
, end
, GFP_ATOMIC
);
1713 } while (bvec
>= bio
->bi_io_vec
);
1716 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1722 extent_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
1727 bio
= bio_alloc(gfp_flags
, nr_vecs
);
1729 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
1730 while (!bio
&& (nr_vecs
/= 2))
1731 bio
= bio_alloc(gfp_flags
, nr_vecs
);
1736 bio
->bi_bdev
= bdev
;
1737 bio
->bi_sector
= first_sector
;
1742 static int submit_one_bio(int rw
, struct bio
*bio
, int mirror_num
)
1745 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1746 struct page
*page
= bvec
->bv_page
;
1747 struct extent_io_tree
*tree
= bio
->bi_private
;
1748 struct rb_node
*node
;
1749 struct extent_state
*state
;
1753 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) + bvec
->bv_offset
;
1754 end
= start
+ bvec
->bv_len
- 1;
1756 spin_lock_irq(&tree
->lock
);
1757 node
= __etree_search(tree
, start
, NULL
, NULL
);
1759 state
= rb_entry(node
, struct extent_state
, rb_node
);
1760 while(state
->end
< end
) {
1761 node
= rb_next(node
);
1762 state
= rb_entry(node
, struct extent_state
, rb_node
);
1764 BUG_ON(state
->end
!= end
);
1765 spin_unlock_irq(&tree
->lock
);
1767 bio
->bi_private
= state
;
1771 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
1772 tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
1775 submit_bio(rw
, bio
);
1776 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
1782 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
1783 struct page
*page
, sector_t sector
,
1784 size_t size
, unsigned long offset
,
1785 struct block_device
*bdev
,
1786 struct bio
**bio_ret
,
1787 unsigned long max_pages
,
1788 bio_end_io_t end_io_func
,
1795 if (bio_ret
&& *bio_ret
) {
1797 if (bio
->bi_sector
+ (bio
->bi_size
>> 9) != sector
||
1798 (tree
->ops
&& tree
->ops
->merge_bio_hook
&&
1799 tree
->ops
->merge_bio_hook(page
, offset
, size
, bio
)) ||
1800 bio_add_page(bio
, page
, size
, offset
) < size
) {
1801 ret
= submit_one_bio(rw
, bio
, mirror_num
);
1807 nr
= bio_get_nr_vecs(bdev
);
1808 bio
= extent_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
1810 printk("failed to allocate bio nr %d\n", nr
);
1814 bio_add_page(bio
, page
, size
, offset
);
1815 bio
->bi_end_io
= end_io_func
;
1816 bio
->bi_private
= tree
;
1821 ret
= submit_one_bio(rw
, bio
, mirror_num
);
1827 void set_page_extent_mapped(struct page
*page
)
1829 if (!PagePrivate(page
)) {
1830 SetPagePrivate(page
);
1831 page_cache_get(page
);
1832 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
1836 void set_page_extent_head(struct page
*page
, unsigned long len
)
1838 set_page_private(page
, EXTENT_PAGE_PRIVATE_FIRST_PAGE
| len
<< 2);
1842 * basic readpage implementation. Locked extent state structs are inserted
1843 * into the tree that are removed when the IO is done (by the end_io
1846 static int __extent_read_full_page(struct extent_io_tree
*tree
,
1848 get_extent_t
*get_extent
,
1849 struct bio
**bio
, int mirror_num
)
1851 struct inode
*inode
= page
->mapping
->host
;
1852 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1853 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
1857 u64 last_byte
= i_size_read(inode
);
1861 struct extent_map
*em
;
1862 struct block_device
*bdev
;
1865 size_t page_offset
= 0;
1867 size_t blocksize
= inode
->i_sb
->s_blocksize
;
1869 set_page_extent_mapped(page
);
1872 lock_extent(tree
, start
, end
, GFP_NOFS
);
1874 while (cur
<= end
) {
1875 if (cur
>= last_byte
) {
1877 iosize
= PAGE_CACHE_SIZE
- page_offset
;
1878 userpage
= kmap_atomic(page
, KM_USER0
);
1879 memset(userpage
+ page_offset
, 0, iosize
);
1880 flush_dcache_page(page
);
1881 kunmap_atomic(userpage
, KM_USER0
);
1882 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
1884 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1887 em
= get_extent(inode
, page
, page_offset
, cur
,
1889 if (IS_ERR(em
) || !em
) {
1891 unlock_extent(tree
, cur
, end
, GFP_NOFS
);
1894 extent_offset
= cur
- em
->start
;
1895 if (extent_map_end(em
) <= cur
) {
1896 printk("bad mapping em [%Lu %Lu] cur %Lu\n", em
->start
, extent_map_end(em
), cur
);
1898 BUG_ON(extent_map_end(em
) <= cur
);
1900 printk("2bad mapping end %Lu cur %Lu\n", end
, cur
);
1904 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
1905 cur_end
= min(extent_map_end(em
) - 1, end
);
1906 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
1907 sector
= (em
->block_start
+ extent_offset
) >> 9;
1909 block_start
= em
->block_start
;
1910 free_extent_map(em
);
1913 /* we've found a hole, just zero and go on */
1914 if (block_start
== EXTENT_MAP_HOLE
) {
1916 userpage
= kmap_atomic(page
, KM_USER0
);
1917 memset(userpage
+ page_offset
, 0, iosize
);
1918 flush_dcache_page(page
);
1919 kunmap_atomic(userpage
, KM_USER0
);
1921 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
1923 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1925 page_offset
+= iosize
;
1928 /* the get_extent function already copied into the page */
1929 if (test_range_bit(tree
, cur
, cur_end
, EXTENT_UPTODATE
, 1)) {
1930 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1932 page_offset
+= iosize
;
1935 /* we have an inline extent but it didn't get marked up
1936 * to date. Error out
1938 if (block_start
== EXTENT_MAP_INLINE
) {
1940 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1942 page_offset
+= iosize
;
1947 if (tree
->ops
&& tree
->ops
->readpage_io_hook
) {
1948 ret
= tree
->ops
->readpage_io_hook(page
, cur
,
1952 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
1954 ret
= submit_extent_page(READ
, tree
, page
,
1955 sector
, iosize
, page_offset
,
1957 end_bio_extent_readpage
, mirror_num
);
1963 page_offset
+= iosize
;
1966 if (!PageError(page
))
1967 SetPageUptodate(page
);
1973 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
1974 get_extent_t
*get_extent
)
1976 struct bio
*bio
= NULL
;
1979 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, 0);
1981 submit_one_bio(READ
, bio
, 0);
1984 EXPORT_SYMBOL(extent_read_full_page
);
1987 * the writepage semantics are similar to regular writepage. extent
1988 * records are inserted to lock ranges in the tree, and as dirty areas
1989 * are found, they are marked writeback. Then the lock bits are removed
1990 * and the end_io handler clears the writeback ranges
1992 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
1995 struct inode
*inode
= page
->mapping
->host
;
1996 struct extent_page_data
*epd
= data
;
1997 struct extent_io_tree
*tree
= epd
->tree
;
1998 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2000 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2004 u64 last_byte
= i_size_read(inode
);
2009 struct extent_map
*em
;
2010 struct block_device
*bdev
;
2013 size_t pg_offset
= 0;
2015 loff_t i_size
= i_size_read(inode
);
2016 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2020 WARN_ON(!PageLocked(page
));
2021 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
2022 if (page
->index
> end_index
||
2023 (page
->index
== end_index
&& !pg_offset
)) {
2024 page
->mapping
->a_ops
->invalidatepage(page
, 0);
2029 if (page
->index
== end_index
) {
2032 userpage
= kmap_atomic(page
, KM_USER0
);
2033 memset(userpage
+ pg_offset
, 0,
2034 PAGE_CACHE_SIZE
- pg_offset
);
2035 kunmap_atomic(userpage
, KM_USER0
);
2036 flush_dcache_page(page
);
2040 set_page_extent_mapped(page
);
2042 delalloc_start
= start
;
2044 while(delalloc_end
< page_end
) {
2045 nr_delalloc
= find_lock_delalloc_range(tree
, &delalloc_start
,
2048 if (nr_delalloc
== 0) {
2049 delalloc_start
= delalloc_end
+ 1;
2052 tree
->ops
->fill_delalloc(inode
, delalloc_start
,
2054 clear_extent_bit(tree
, delalloc_start
,
2056 EXTENT_LOCKED
| EXTENT_DELALLOC
,
2058 delalloc_start
= delalloc_end
+ 1;
2060 lock_extent(tree
, start
, page_end
, GFP_NOFS
);
2061 unlock_start
= start
;
2063 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
2064 ret
= tree
->ops
->writepage_start_hook(page
, start
, page_end
);
2065 if (ret
== -EAGAIN
) {
2066 unlock_extent(tree
, start
, page_end
, GFP_NOFS
);
2067 redirty_page_for_writepage(wbc
, page
);
2074 if (test_range_bit(tree
, start
, page_end
, EXTENT_DELALLOC
, 0)) {
2075 printk("found delalloc bits after lock_extent\n");
2078 if (last_byte
<= start
) {
2079 clear_extent_dirty(tree
, start
, page_end
, GFP_NOFS
);
2080 unlock_extent(tree
, start
, page_end
, GFP_NOFS
);
2081 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2082 tree
->ops
->writepage_end_io_hook(page
, start
,
2084 unlock_start
= page_end
+ 1;
2088 set_extent_uptodate(tree
, start
, page_end
, GFP_NOFS
);
2089 blocksize
= inode
->i_sb
->s_blocksize
;
2091 while (cur
<= end
) {
2092 if (cur
>= last_byte
) {
2093 clear_extent_dirty(tree
, cur
, page_end
, GFP_NOFS
);
2094 unlock_extent(tree
, unlock_start
, page_end
, GFP_NOFS
);
2095 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2096 tree
->ops
->writepage_end_io_hook(page
, cur
,
2098 unlock_start
= page_end
+ 1;
2101 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
2103 if (IS_ERR(em
) || !em
) {
2108 extent_offset
= cur
- em
->start
;
2109 BUG_ON(extent_map_end(em
) <= cur
);
2111 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2112 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
2113 sector
= (em
->block_start
+ extent_offset
) >> 9;
2115 block_start
= em
->block_start
;
2116 free_extent_map(em
);
2119 if (block_start
== EXTENT_MAP_HOLE
||
2120 block_start
== EXTENT_MAP_INLINE
) {
2121 clear_extent_dirty(tree
, cur
,
2122 cur
+ iosize
- 1, GFP_NOFS
);
2124 unlock_extent(tree
, unlock_start
, cur
+ iosize
-1,
2127 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2128 tree
->ops
->writepage_end_io_hook(page
, cur
,
2132 pg_offset
+= iosize
;
2137 /* leave this out until we have a page_mkwrite call */
2138 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
2141 pg_offset
+= iosize
;
2144 clear_extent_dirty(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2145 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
2146 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
2154 unsigned long max_nr
= end_index
+ 1;
2156 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
2157 if (!PageWriteback(page
)) {
2158 printk("warning page %lu not writeback, "
2159 "cur %llu end %llu\n", page
->index
,
2160 (unsigned long long)cur
,
2161 (unsigned long long)end
);
2164 ret
= submit_extent_page(WRITE
, tree
, page
, sector
,
2165 iosize
, pg_offset
, bdev
,
2167 end_bio_extent_writepage
, 0);
2172 pg_offset
+= iosize
;
2177 /* make sure the mapping tag for page dirty gets cleared */
2178 set_page_writeback(page
);
2179 end_page_writeback(page
);
2181 if (unlock_start
<= page_end
)
2182 unlock_extent(tree
, unlock_start
, page_end
, GFP_NOFS
);
2187 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
2188 /* Taken directly from 2.6.23 for 2.6.18 back port */
2189 typedef int (*writepage_t
)(struct page
*page
, struct writeback_control
*wbc
,
2193 * write_cache_pages - walk the list of dirty pages of the given address space
2194 * and write all of them.
2195 * @mapping: address space structure to write
2196 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2197 * @writepage: function called for each page
2198 * @data: data passed to writepage function
2200 * If a page is already under I/O, write_cache_pages() skips it, even
2201 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2202 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2203 * and msync() need to guarantee that all the data which was dirty at the time
2204 * the call was made get new I/O started against them. If wbc->sync_mode is
2205 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2206 * existing IO to complete.
2208 static int write_cache_pages(struct address_space
*mapping
,
2209 struct writeback_control
*wbc
, writepage_t writepage
,
2212 struct backing_dev_info
*bdi
= mapping
->backing_dev_info
;
2215 struct pagevec pvec
;
2218 pgoff_t end
; /* Inclusive */
2220 int range_whole
= 0;
2222 if (wbc
->nonblocking
&& bdi_write_congested(bdi
)) {
2223 wbc
->encountered_congestion
= 1;
2227 pagevec_init(&pvec
, 0);
2228 if (wbc
->range_cyclic
) {
2229 index
= mapping
->writeback_index
; /* Start from prev offset */
2232 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2233 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
2234 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2239 while (!done
&& (index
<= end
) &&
2240 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
2241 PAGECACHE_TAG_DIRTY
,
2242 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
2246 for (i
= 0; i
< nr_pages
; i
++) {
2247 struct page
*page
= pvec
.pages
[i
];
2250 * At this point we hold neither mapping->tree_lock nor
2251 * lock on the page itself: the page may be truncated or
2252 * invalidated (changing page->mapping to NULL), or even
2253 * swizzled back from swapper_space to tmpfs file
2258 if (unlikely(page
->mapping
!= mapping
)) {
2263 if (!wbc
->range_cyclic
&& page
->index
> end
) {
2269 if (wbc
->sync_mode
!= WB_SYNC_NONE
)
2270 wait_on_page_writeback(page
);
2272 if (PageWriteback(page
) ||
2273 !clear_page_dirty_for_io(page
)) {
2278 ret
= (*writepage
)(page
, wbc
, data
);
2280 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
2284 if (ret
|| (--(wbc
->nr_to_write
) <= 0))
2286 if (wbc
->nonblocking
&& bdi_write_congested(bdi
)) {
2287 wbc
->encountered_congestion
= 1;
2291 pagevec_release(&pvec
);
2294 if (!scanned
&& !done
) {
2296 * We hit the last page and there is more work to be done: wrap
2297 * back to the start of the file
2303 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
2304 mapping
->writeback_index
= index
;
2309 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2310 get_extent_t
*get_extent
,
2311 struct writeback_control
*wbc
)
2314 struct address_space
*mapping
= page
->mapping
;
2315 struct extent_page_data epd
= {
2318 .get_extent
= get_extent
,
2320 struct writeback_control wbc_writepages
= {
2322 .sync_mode
= WB_SYNC_NONE
,
2323 .older_than_this
= NULL
,
2325 .range_start
= page_offset(page
) + PAGE_CACHE_SIZE
,
2326 .range_end
= (loff_t
)-1,
2330 ret
= __extent_writepage(page
, wbc
, &epd
);
2332 write_cache_pages(mapping
, &wbc_writepages
, __extent_writepage
, &epd
);
2334 submit_one_bio(WRITE
, epd
.bio
, 0);
2338 EXPORT_SYMBOL(extent_write_full_page
);
2341 int extent_writepages(struct extent_io_tree
*tree
,
2342 struct address_space
*mapping
,
2343 get_extent_t
*get_extent
,
2344 struct writeback_control
*wbc
)
2347 struct extent_page_data epd
= {
2350 .get_extent
= get_extent
,
2353 ret
= write_cache_pages(mapping
, wbc
, __extent_writepage
, &epd
);
2355 submit_one_bio(WRITE
, epd
.bio
, 0);
2359 EXPORT_SYMBOL(extent_writepages
);
2361 int extent_readpages(struct extent_io_tree
*tree
,
2362 struct address_space
*mapping
,
2363 struct list_head
*pages
, unsigned nr_pages
,
2364 get_extent_t get_extent
)
2366 struct bio
*bio
= NULL
;
2368 struct pagevec pvec
;
2370 pagevec_init(&pvec
, 0);
2371 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
2372 struct page
*page
= list_entry(pages
->prev
, struct page
, lru
);
2374 prefetchw(&page
->flags
);
2375 list_del(&page
->lru
);
2377 * what we want to do here is call add_to_page_cache_lru,
2378 * but that isn't exported, so we reproduce it here
2380 if (!add_to_page_cache(page
, mapping
,
2381 page
->index
, GFP_KERNEL
)) {
2383 /* open coding of lru_cache_add, also not exported */
2384 page_cache_get(page
);
2385 if (!pagevec_add(&pvec
, page
))
2386 __pagevec_lru_add(&pvec
);
2387 __extent_read_full_page(tree
, page
, get_extent
,
2390 page_cache_release(page
);
2392 if (pagevec_count(&pvec
))
2393 __pagevec_lru_add(&pvec
);
2394 BUG_ON(!list_empty(pages
));
2396 submit_one_bio(READ
, bio
, 0);
2399 EXPORT_SYMBOL(extent_readpages
);
2402 * basic invalidatepage code, this waits on any locked or writeback
2403 * ranges corresponding to the page, and then deletes any extent state
2404 * records from the tree
2406 int extent_invalidatepage(struct extent_io_tree
*tree
,
2407 struct page
*page
, unsigned long offset
)
2409 u64 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
);
2410 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2411 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
2413 start
+= (offset
+ blocksize
-1) & ~(blocksize
- 1);
2417 lock_extent(tree
, start
, end
, GFP_NOFS
);
2418 wait_on_extent_writeback(tree
, start
, end
);
2419 clear_extent_bit(tree
, start
, end
,
2420 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
,
2424 EXPORT_SYMBOL(extent_invalidatepage
);
2427 * simple commit_write call, set_range_dirty is used to mark both
2428 * the pages and the extent records as dirty
2430 int extent_commit_write(struct extent_io_tree
*tree
,
2431 struct inode
*inode
, struct page
*page
,
2432 unsigned from
, unsigned to
)
2434 loff_t pos
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
2436 set_page_extent_mapped(page
);
2437 set_page_dirty(page
);
2439 if (pos
> inode
->i_size
) {
2440 i_size_write(inode
, pos
);
2441 mark_inode_dirty(inode
);
2445 EXPORT_SYMBOL(extent_commit_write
);
2447 int extent_prepare_write(struct extent_io_tree
*tree
,
2448 struct inode
*inode
, struct page
*page
,
2449 unsigned from
, unsigned to
, get_extent_t
*get_extent
)
2451 u64 page_start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2452 u64 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
2454 u64 orig_block_start
;
2457 struct extent_map
*em
;
2458 unsigned blocksize
= 1 << inode
->i_blkbits
;
2459 size_t page_offset
= 0;
2460 size_t block_off_start
;
2461 size_t block_off_end
;
2467 set_page_extent_mapped(page
);
2469 block_start
= (page_start
+ from
) & ~((u64
)blocksize
- 1);
2470 block_end
= (page_start
+ to
- 1) | (blocksize
- 1);
2471 orig_block_start
= block_start
;
2473 lock_extent(tree
, page_start
, page_end
, GFP_NOFS
);
2474 while(block_start
<= block_end
) {
2475 em
= get_extent(inode
, page
, page_offset
, block_start
,
2476 block_end
- block_start
+ 1, 1);
2477 if (IS_ERR(em
) || !em
) {
2480 cur_end
= min(block_end
, extent_map_end(em
) - 1);
2481 block_off_start
= block_start
& (PAGE_CACHE_SIZE
- 1);
2482 block_off_end
= block_off_start
+ blocksize
;
2483 isnew
= clear_extent_new(tree
, block_start
, cur_end
, GFP_NOFS
);
2485 if (!PageUptodate(page
) && isnew
&&
2486 (block_off_end
> to
|| block_off_start
< from
)) {
2489 kaddr
= kmap_atomic(page
, KM_USER0
);
2490 if (block_off_end
> to
)
2491 memset(kaddr
+ to
, 0, block_off_end
- to
);
2492 if (block_off_start
< from
)
2493 memset(kaddr
+ block_off_start
, 0,
2494 from
- block_off_start
);
2495 flush_dcache_page(page
);
2496 kunmap_atomic(kaddr
, KM_USER0
);
2498 if ((em
->block_start
!= EXTENT_MAP_HOLE
&&
2499 em
->block_start
!= EXTENT_MAP_INLINE
) &&
2500 !isnew
&& !PageUptodate(page
) &&
2501 (block_off_end
> to
|| block_off_start
< from
) &&
2502 !test_range_bit(tree
, block_start
, cur_end
,
2503 EXTENT_UPTODATE
, 1)) {
2505 u64 extent_offset
= block_start
- em
->start
;
2507 sector
= (em
->block_start
+ extent_offset
) >> 9;
2508 iosize
= (cur_end
- block_start
+ blocksize
) &
2509 ~((u64
)blocksize
- 1);
2511 * we've already got the extent locked, but we
2512 * need to split the state such that our end_bio
2513 * handler can clear the lock.
2515 set_extent_bit(tree
, block_start
,
2516 block_start
+ iosize
- 1,
2517 EXTENT_LOCKED
, 0, NULL
, GFP_NOFS
);
2518 ret
= submit_extent_page(READ
, tree
, page
,
2519 sector
, iosize
, page_offset
, em
->bdev
,
2521 end_bio_extent_preparewrite
, 0);
2523 block_start
= block_start
+ iosize
;
2525 set_extent_uptodate(tree
, block_start
, cur_end
,
2527 unlock_extent(tree
, block_start
, cur_end
, GFP_NOFS
);
2528 block_start
= cur_end
+ 1;
2530 page_offset
= block_start
& (PAGE_CACHE_SIZE
- 1);
2531 free_extent_map(em
);
2534 wait_extent_bit(tree
, orig_block_start
,
2535 block_end
, EXTENT_LOCKED
);
2537 check_page_uptodate(tree
, page
);
2539 /* FIXME, zero out newly allocated blocks on error */
2542 EXPORT_SYMBOL(extent_prepare_write
);
2545 * a helper for releasepage, this tests for areas of the page that
2546 * are locked or under IO and drops the related state bits if it is safe
2549 int try_release_extent_state(struct extent_map_tree
*map
,
2550 struct extent_io_tree
*tree
, struct page
*page
,
2553 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2554 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2557 if (test_range_bit(tree
, start
, end
,
2558 EXTENT_IOBITS
| EXTENT_ORDERED
, 0))
2561 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
2563 clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
,
2568 EXPORT_SYMBOL(try_release_extent_state
);
2571 * a helper for releasepage. As long as there are no locked extents
2572 * in the range corresponding to the page, both state records and extent
2573 * map records are removed
2575 int try_release_extent_mapping(struct extent_map_tree
*map
,
2576 struct extent_io_tree
*tree
, struct page
*page
,
2579 struct extent_map
*em
;
2580 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2581 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2583 if ((mask
& __GFP_WAIT
) &&
2584 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
2586 while (start
<= end
) {
2587 len
= end
- start
+ 1;
2588 spin_lock(&map
->lock
);
2589 em
= lookup_extent_mapping(map
, start
, len
);
2590 if (!em
|| IS_ERR(em
)) {
2591 spin_unlock(&map
->lock
);
2594 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
2595 em
->start
!= start
) {
2596 spin_unlock(&map
->lock
);
2597 free_extent_map(em
);
2600 if (!test_range_bit(tree
, em
->start
,
2601 extent_map_end(em
) - 1,
2602 EXTENT_LOCKED
, 0)) {
2603 remove_extent_mapping(map
, em
);
2604 /* once for the rb tree */
2605 free_extent_map(em
);
2607 start
= extent_map_end(em
);
2608 spin_unlock(&map
->lock
);
2611 free_extent_map(em
);
2614 return try_release_extent_state(map
, tree
, page
, mask
);
2616 EXPORT_SYMBOL(try_release_extent_mapping
);
2618 sector_t
extent_bmap(struct address_space
*mapping
, sector_t iblock
,
2619 get_extent_t
*get_extent
)
2621 struct inode
*inode
= mapping
->host
;
2622 u64 start
= iblock
<< inode
->i_blkbits
;
2623 sector_t sector
= 0;
2624 struct extent_map
*em
;
2626 em
= get_extent(inode
, NULL
, 0, start
, (1 << inode
->i_blkbits
), 0);
2627 if (!em
|| IS_ERR(em
))
2630 if (em
->block_start
== EXTENT_MAP_INLINE
||
2631 em
->block_start
== EXTENT_MAP_HOLE
)
2634 sector
= (em
->block_start
+ start
- em
->start
) >> inode
->i_blkbits
;
2636 free_extent_map(em
);
2640 static inline struct page
*extent_buffer_page(struct extent_buffer
*eb
,
2644 struct address_space
*mapping
;
2647 return eb
->first_page
;
2648 i
+= eb
->start
>> PAGE_CACHE_SHIFT
;
2649 mapping
= eb
->first_page
->mapping
;
2654 * extent_buffer_page is only called after pinning the page
2655 * by increasing the reference count. So we know the page must
2656 * be in the radix tree.
2658 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
2661 read_lock_irq(&mapping
->tree_lock
);
2663 p
= radix_tree_lookup(&mapping
->page_tree
, i
);
2665 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
2668 read_unlock_irq(&mapping
->tree_lock
);
2673 static inline unsigned long num_extent_pages(u64 start
, u64 len
)
2675 return ((start
+ len
+ PAGE_CACHE_SIZE
- 1) >> PAGE_CACHE_SHIFT
) -
2676 (start
>> PAGE_CACHE_SHIFT
);
2679 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
2684 struct extent_buffer
*eb
= NULL
;
2685 unsigned long flags
;
2687 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
2690 mutex_init(&eb
->mutex
);
2691 spin_lock_irqsave(&leak_lock
, flags
);
2692 list_add(&eb
->leak_list
, &buffers
);
2693 spin_unlock_irqrestore(&leak_lock
, flags
);
2694 atomic_set(&eb
->refs
, 1);
2699 static void __free_extent_buffer(struct extent_buffer
*eb
)
2701 unsigned long flags
;
2702 spin_lock_irqsave(&leak_lock
, flags
);
2703 list_del(&eb
->leak_list
);
2704 spin_unlock_irqrestore(&leak_lock
, flags
);
2705 kmem_cache_free(extent_buffer_cache
, eb
);
2708 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
2709 u64 start
, unsigned long len
,
2713 unsigned long num_pages
= num_extent_pages(start
, len
);
2715 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
2716 struct extent_buffer
*eb
;
2717 struct extent_buffer
*exists
= NULL
;
2719 struct address_space
*mapping
= tree
->mapping
;
2722 spin_lock(&tree
->buffer_lock
);
2723 eb
= buffer_search(tree
, start
);
2725 atomic_inc(&eb
->refs
);
2726 spin_unlock(&tree
->buffer_lock
);
2729 spin_unlock(&tree
->buffer_lock
);
2731 eb
= __alloc_extent_buffer(tree
, start
, len
, mask
);
2736 eb
->first_page
= page0
;
2739 page_cache_get(page0
);
2740 mark_page_accessed(page0
);
2741 set_page_extent_mapped(page0
);
2742 set_page_extent_head(page0
, len
);
2743 uptodate
= PageUptodate(page0
);
2747 for (; i
< num_pages
; i
++, index
++) {
2748 p
= find_or_create_page(mapping
, index
, mask
| __GFP_HIGHMEM
);
2753 set_page_extent_mapped(p
);
2754 mark_page_accessed(p
);
2757 set_page_extent_head(p
, len
);
2759 set_page_private(p
, EXTENT_PAGE_PRIVATE
);
2761 if (!PageUptodate(p
))
2766 eb
->flags
|= EXTENT_UPTODATE
;
2767 eb
->flags
|= EXTENT_BUFFER_FILLED
;
2769 spin_lock(&tree
->buffer_lock
);
2770 exists
= buffer_tree_insert(tree
, start
, &eb
->rb_node
);
2772 /* add one reference for the caller */
2773 atomic_inc(&exists
->refs
);
2774 spin_unlock(&tree
->buffer_lock
);
2777 spin_unlock(&tree
->buffer_lock
);
2779 /* add one reference for the tree */
2780 atomic_inc(&eb
->refs
);
2784 if (!atomic_dec_and_test(&eb
->refs
))
2786 for (index
= 1; index
< i
; index
++)
2787 page_cache_release(extent_buffer_page(eb
, index
));
2788 page_cache_release(extent_buffer_page(eb
, 0));
2789 __free_extent_buffer(eb
);
2792 EXPORT_SYMBOL(alloc_extent_buffer
);
2794 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
2795 u64 start
, unsigned long len
,
2798 struct extent_buffer
*eb
;
2800 spin_lock(&tree
->buffer_lock
);
2801 eb
= buffer_search(tree
, start
);
2803 atomic_inc(&eb
->refs
);
2804 spin_unlock(&tree
->buffer_lock
);
2808 EXPORT_SYMBOL(find_extent_buffer
);
2810 void free_extent_buffer(struct extent_buffer
*eb
)
2815 if (!atomic_dec_and_test(&eb
->refs
))
2820 EXPORT_SYMBOL(free_extent_buffer
);
2822 int clear_extent_buffer_dirty(struct extent_io_tree
*tree
,
2823 struct extent_buffer
*eb
)
2827 unsigned long num_pages
;
2830 u64 start
= eb
->start
;
2831 u64 end
= start
+ eb
->len
- 1;
2833 set
= clear_extent_dirty(tree
, start
, end
, GFP_NOFS
);
2834 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2836 for (i
= 0; i
< num_pages
; i
++) {
2837 page
= extent_buffer_page(eb
, i
);
2840 set_page_extent_head(page
, eb
->len
);
2842 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2845 * if we're on the last page or the first page and the
2846 * block isn't aligned on a page boundary, do extra checks
2847 * to make sure we don't clean page that is partially dirty
2849 if ((i
== 0 && (eb
->start
& (PAGE_CACHE_SIZE
- 1))) ||
2850 ((i
== num_pages
- 1) &&
2851 ((eb
->start
+ eb
->len
) & (PAGE_CACHE_SIZE
- 1)))) {
2852 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2853 end
= start
+ PAGE_CACHE_SIZE
- 1;
2854 if (test_range_bit(tree
, start
, end
,
2860 clear_page_dirty_for_io(page
);
2861 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
2862 spin_lock_irq(&page
->mapping
->tree_lock
);
2864 read_lock_irq(&page
->mapping
->tree_lock
);
2866 if (!PageDirty(page
)) {
2867 radix_tree_tag_clear(&page
->mapping
->page_tree
,
2869 PAGECACHE_TAG_DIRTY
);
2871 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
2872 spin_unlock_irq(&page
->mapping
->tree_lock
);
2874 read_unlock_irq(&page
->mapping
->tree_lock
);
2880 EXPORT_SYMBOL(clear_extent_buffer_dirty
);
2882 int wait_on_extent_buffer_writeback(struct extent_io_tree
*tree
,
2883 struct extent_buffer
*eb
)
2885 return wait_on_extent_writeback(tree
, eb
->start
,
2886 eb
->start
+ eb
->len
- 1);
2888 EXPORT_SYMBOL(wait_on_extent_buffer_writeback
);
2890 int set_extent_buffer_dirty(struct extent_io_tree
*tree
,
2891 struct extent_buffer
*eb
)
2894 unsigned long num_pages
;
2896 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2897 for (i
= 0; i
< num_pages
; i
++) {
2898 struct page
*page
= extent_buffer_page(eb
, i
);
2899 /* writepage may need to do something special for the
2900 * first page, we have to make sure page->private is
2901 * properly set. releasepage may drop page->private
2902 * on us if the page isn't already dirty.
2906 set_page_extent_head(page
, eb
->len
);
2907 } else if (PagePrivate(page
) &&
2908 page
->private != EXTENT_PAGE_PRIVATE
) {
2910 set_page_extent_mapped(page
);
2913 __set_page_dirty_nobuffers(extent_buffer_page(eb
, i
));
2917 return set_extent_dirty(tree
, eb
->start
,
2918 eb
->start
+ eb
->len
- 1, GFP_NOFS
);
2920 EXPORT_SYMBOL(set_extent_buffer_dirty
);
2922 int clear_extent_buffer_uptodate(struct extent_io_tree
*tree
,
2923 struct extent_buffer
*eb
)
2927 unsigned long num_pages
;
2929 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2930 eb
->flags
&= ~EXTENT_UPTODATE
;
2932 clear_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
2934 for (i
= 0; i
< num_pages
; i
++) {
2935 page
= extent_buffer_page(eb
, i
);
2937 ClearPageUptodate(page
);
2942 int set_extent_buffer_uptodate(struct extent_io_tree
*tree
,
2943 struct extent_buffer
*eb
)
2947 unsigned long num_pages
;
2949 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2951 set_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
2953 for (i
= 0; i
< num_pages
; i
++) {
2954 page
= extent_buffer_page(eb
, i
);
2955 if ((i
== 0 && (eb
->start
& (PAGE_CACHE_SIZE
- 1))) ||
2956 ((i
== num_pages
- 1) &&
2957 ((eb
->start
+ eb
->len
) & (PAGE_CACHE_SIZE
- 1)))) {
2958 check_page_uptodate(tree
, page
);
2961 SetPageUptodate(page
);
2965 EXPORT_SYMBOL(set_extent_buffer_uptodate
);
2967 int extent_range_uptodate(struct extent_io_tree
*tree
,
2972 int pg_uptodate
= 1;
2974 unsigned long index
;
2976 ret
= test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1);
2979 while(start
<= end
) {
2980 index
= start
>> PAGE_CACHE_SHIFT
;
2981 page
= find_get_page(tree
->mapping
, index
);
2982 uptodate
= PageUptodate(page
);
2983 page_cache_release(page
);
2988 start
+= PAGE_CACHE_SIZE
;
2993 int extent_buffer_uptodate(struct extent_io_tree
*tree
,
2994 struct extent_buffer
*eb
)
2997 unsigned long num_pages
;
3000 int pg_uptodate
= 1;
3002 if (eb
->flags
& EXTENT_UPTODATE
)
3005 ret
= test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3006 EXTENT_UPTODATE
, 1);
3010 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3011 for (i
= 0; i
< num_pages
; i
++) {
3012 page
= extent_buffer_page(eb
, i
);
3013 if (!PageUptodate(page
)) {
3020 EXPORT_SYMBOL(extent_buffer_uptodate
);
3022 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
3023 struct extent_buffer
*eb
,
3024 u64 start
, int wait
,
3025 get_extent_t
*get_extent
, int mirror_num
)
3028 unsigned long start_i
;
3032 int locked_pages
= 0;
3033 int all_uptodate
= 1;
3034 int inc_all_pages
= 0;
3035 unsigned long num_pages
;
3036 struct bio
*bio
= NULL
;
3038 if (eb
->flags
& EXTENT_UPTODATE
)
3041 if (test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3042 EXTENT_UPTODATE
, 1)) {
3047 WARN_ON(start
< eb
->start
);
3048 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
3049 (eb
->start
>> PAGE_CACHE_SHIFT
);
3054 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3055 for (i
= start_i
; i
< num_pages
; i
++) {
3056 page
= extent_buffer_page(eb
, i
);
3058 if (TestSetPageLocked(page
))
3064 if (!PageUptodate(page
)) {
3070 eb
->flags
|= EXTENT_UPTODATE
;
3074 for (i
= start_i
; i
< num_pages
; i
++) {
3075 page
= extent_buffer_page(eb
, i
);
3077 page_cache_get(page
);
3078 if (!PageUptodate(page
)) {
3081 ClearPageError(page
);
3082 err
= __extent_read_full_page(tree
, page
,
3094 submit_one_bio(READ
, bio
, mirror_num
);
3099 for (i
= start_i
; i
< num_pages
; i
++) {
3100 page
= extent_buffer_page(eb
, i
);
3101 wait_on_page_locked(page
);
3102 if (!PageUptodate(page
)) {
3107 eb
->flags
|= EXTENT_UPTODATE
;
3112 while(locked_pages
> 0) {
3113 page
= extent_buffer_page(eb
, i
);
3120 EXPORT_SYMBOL(read_extent_buffer_pages
);
3122 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
3123 unsigned long start
,
3130 char *dst
= (char *)dstv
;
3131 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3132 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3134 WARN_ON(start
> eb
->len
);
3135 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3137 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3140 page
= extent_buffer_page(eb
, i
);
3142 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
3143 kaddr
= kmap_atomic(page
, KM_USER1
);
3144 memcpy(dst
, kaddr
+ offset
, cur
);
3145 kunmap_atomic(kaddr
, KM_USER1
);
3153 EXPORT_SYMBOL(read_extent_buffer
);
3155 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
3156 unsigned long min_len
, char **token
, char **map
,
3157 unsigned long *map_start
,
3158 unsigned long *map_len
, int km
)
3160 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
3163 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3164 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3165 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
3172 offset
= start_offset
;
3176 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
3178 if (start
+ min_len
> eb
->len
) {
3179 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb
->start
, eb
->len
, start
, min_len
);
3183 p
= extent_buffer_page(eb
, i
);
3184 kaddr
= kmap_atomic(p
, km
);
3186 *map
= kaddr
+ offset
;
3187 *map_len
= PAGE_CACHE_SIZE
- offset
;
3190 EXPORT_SYMBOL(map_private_extent_buffer
);
3192 int map_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
3193 unsigned long min_len
,
3194 char **token
, char **map
,
3195 unsigned long *map_start
,
3196 unsigned long *map_len
, int km
)
3200 if (eb
->map_token
) {
3201 unmap_extent_buffer(eb
, eb
->map_token
, km
);
3202 eb
->map_token
= NULL
;
3205 err
= map_private_extent_buffer(eb
, start
, min_len
, token
, map
,
3206 map_start
, map_len
, km
);
3208 eb
->map_token
= *token
;
3210 eb
->map_start
= *map_start
;
3211 eb
->map_len
= *map_len
;
3215 EXPORT_SYMBOL(map_extent_buffer
);
3217 void unmap_extent_buffer(struct extent_buffer
*eb
, char *token
, int km
)
3219 kunmap_atomic(token
, km
);
3221 EXPORT_SYMBOL(unmap_extent_buffer
);
3223 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
3224 unsigned long start
,
3231 char *ptr
= (char *)ptrv
;
3232 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3233 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3236 WARN_ON(start
> eb
->len
);
3237 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3239 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3242 page
= extent_buffer_page(eb
, i
);
3244 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
3246 kaddr
= kmap_atomic(page
, KM_USER0
);
3247 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
3248 kunmap_atomic(kaddr
, KM_USER0
);
3259 EXPORT_SYMBOL(memcmp_extent_buffer
);
3261 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
3262 unsigned long start
, unsigned long len
)
3268 char *src
= (char *)srcv
;
3269 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3270 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3272 WARN_ON(start
> eb
->len
);
3273 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3275 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3278 page
= extent_buffer_page(eb
, i
);
3279 WARN_ON(!PageUptodate(page
));
3281 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
3282 kaddr
= kmap_atomic(page
, KM_USER1
);
3283 memcpy(kaddr
+ offset
, src
, cur
);
3284 kunmap_atomic(kaddr
, KM_USER1
);
3292 EXPORT_SYMBOL(write_extent_buffer
);
3294 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
3295 unsigned long start
, unsigned long len
)
3301 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3302 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3304 WARN_ON(start
> eb
->len
);
3305 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3307 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3310 page
= extent_buffer_page(eb
, i
);
3311 WARN_ON(!PageUptodate(page
));
3313 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
3314 kaddr
= kmap_atomic(page
, KM_USER0
);
3315 memset(kaddr
+ offset
, c
, cur
);
3316 kunmap_atomic(kaddr
, KM_USER0
);
3323 EXPORT_SYMBOL(memset_extent_buffer
);
3325 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
3326 unsigned long dst_offset
, unsigned long src_offset
,
3329 u64 dst_len
= dst
->len
;
3334 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3335 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
3337 WARN_ON(src
->len
!= dst_len
);
3339 offset
= (start_offset
+ dst_offset
) &
3340 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3343 page
= extent_buffer_page(dst
, i
);
3344 WARN_ON(!PageUptodate(page
));
3346 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
3348 kaddr
= kmap_atomic(page
, KM_USER0
);
3349 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
3350 kunmap_atomic(kaddr
, KM_USER0
);
3358 EXPORT_SYMBOL(copy_extent_buffer
);
3360 static void move_pages(struct page
*dst_page
, struct page
*src_page
,
3361 unsigned long dst_off
, unsigned long src_off
,
3364 char *dst_kaddr
= kmap_atomic(dst_page
, KM_USER0
);
3365 if (dst_page
== src_page
) {
3366 memmove(dst_kaddr
+ dst_off
, dst_kaddr
+ src_off
, len
);
3368 char *src_kaddr
= kmap_atomic(src_page
, KM_USER1
);
3369 char *p
= dst_kaddr
+ dst_off
+ len
;
3370 char *s
= src_kaddr
+ src_off
+ len
;
3375 kunmap_atomic(src_kaddr
, KM_USER1
);
3377 kunmap_atomic(dst_kaddr
, KM_USER0
);
3380 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
3381 unsigned long dst_off
, unsigned long src_off
,
3384 char *dst_kaddr
= kmap_atomic(dst_page
, KM_USER0
);
3387 if (dst_page
!= src_page
)
3388 src_kaddr
= kmap_atomic(src_page
, KM_USER1
);
3390 src_kaddr
= dst_kaddr
;
3392 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
3393 kunmap_atomic(dst_kaddr
, KM_USER0
);
3394 if (dst_page
!= src_page
)
3395 kunmap_atomic(src_kaddr
, KM_USER1
);
3398 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
3399 unsigned long src_offset
, unsigned long len
)
3402 size_t dst_off_in_page
;
3403 size_t src_off_in_page
;
3404 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3405 unsigned long dst_i
;
3406 unsigned long src_i
;
3408 if (src_offset
+ len
> dst
->len
) {
3409 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
3410 src_offset
, len
, dst
->len
);
3413 if (dst_offset
+ len
> dst
->len
) {
3414 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
3415 dst_offset
, len
, dst
->len
);
3420 dst_off_in_page
= (start_offset
+ dst_offset
) &
3421 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3422 src_off_in_page
= (start_offset
+ src_offset
) &
3423 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3425 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
3426 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
3428 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
3430 cur
= min_t(unsigned long, cur
,
3431 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
3433 copy_pages(extent_buffer_page(dst
, dst_i
),
3434 extent_buffer_page(dst
, src_i
),
3435 dst_off_in_page
, src_off_in_page
, cur
);
3442 EXPORT_SYMBOL(memcpy_extent_buffer
);
3444 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
3445 unsigned long src_offset
, unsigned long len
)
3448 size_t dst_off_in_page
;
3449 size_t src_off_in_page
;
3450 unsigned long dst_end
= dst_offset
+ len
- 1;
3451 unsigned long src_end
= src_offset
+ len
- 1;
3452 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3453 unsigned long dst_i
;
3454 unsigned long src_i
;
3456 if (src_offset
+ len
> dst
->len
) {
3457 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
3458 src_offset
, len
, dst
->len
);
3461 if (dst_offset
+ len
> dst
->len
) {
3462 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
3463 dst_offset
, len
, dst
->len
);
3466 if (dst_offset
< src_offset
) {
3467 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
3471 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
3472 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
3474 dst_off_in_page
= (start_offset
+ dst_end
) &
3475 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3476 src_off_in_page
= (start_offset
+ src_end
) &
3477 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3479 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
3480 cur
= min(cur
, dst_off_in_page
+ 1);
3481 move_pages(extent_buffer_page(dst
, dst_i
),
3482 extent_buffer_page(dst
, src_i
),
3483 dst_off_in_page
- cur
+ 1,
3484 src_off_in_page
- cur
+ 1, cur
);
3491 EXPORT_SYMBOL(memmove_extent_buffer
);
3493 int try_release_extent_buffer(struct extent_io_tree
*tree
, struct page
*page
)
3495 u64 start
= page_offset(page
);
3496 struct extent_buffer
*eb
;
3499 unsigned long num_pages
;
3501 spin_lock(&tree
->buffer_lock
);
3502 eb
= buffer_search(tree
, start
);
3506 if (atomic_read(&eb
->refs
) > 1) {
3510 /* at this point we can safely release the extent buffer */
3511 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3512 for (i
= 0; i
< num_pages
; i
++) {
3513 struct page
*page
= extent_buffer_page(eb
, i
);
3514 page_cache_release(page
);
3516 rb_erase(&eb
->rb_node
, &tree
->buffer
);
3517 __free_extent_buffer(eb
);
3519 spin_unlock(&tree
->buffer_lock
);
3522 EXPORT_SYMBOL(try_release_extent_buffer
);