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"
19 #include "btrfs_inode.h"
21 /* temporary define until extent_map moves out of btrfs */
22 struct kmem_cache
*btrfs_cache_create(const char *name
, size_t size
,
23 unsigned long extra_flags
,
24 void (*ctor
)(void *, struct kmem_cache
*,
27 static struct kmem_cache
*extent_state_cache
;
28 static struct kmem_cache
*extent_buffer_cache
;
30 static LIST_HEAD(buffers
);
31 static LIST_HEAD(states
);
35 static spinlock_t leak_lock
= SPIN_LOCK_UNLOCKED
;
38 #define BUFFER_LRU_MAX 64
43 struct rb_node rb_node
;
46 struct extent_page_data
{
48 struct extent_io_tree
*tree
;
49 get_extent_t
*get_extent
;
51 /* tells writepage not to lock the state bits for this range
52 * it still does the unlocking
57 int __init
extent_io_init(void)
59 extent_state_cache
= btrfs_cache_create("extent_state",
60 sizeof(struct extent_state
), 0,
62 if (!extent_state_cache
)
65 extent_buffer_cache
= btrfs_cache_create("extent_buffers",
66 sizeof(struct extent_buffer
), 0,
68 if (!extent_buffer_cache
)
69 goto free_state_cache
;
73 kmem_cache_destroy(extent_state_cache
);
77 void extent_io_exit(void)
79 struct extent_state
*state
;
80 struct extent_buffer
*eb
;
82 while (!list_empty(&states
)) {
83 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
84 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
));
85 list_del(&state
->leak_list
);
86 kmem_cache_free(extent_state_cache
, state
);
90 while (!list_empty(&buffers
)) {
91 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
92 printk("buffer leak start %Lu len %lu refs %d\n", eb
->start
, eb
->len
, atomic_read(&eb
->refs
));
93 list_del(&eb
->leak_list
);
94 kmem_cache_free(extent_buffer_cache
, eb
);
96 if (extent_state_cache
)
97 kmem_cache_destroy(extent_state_cache
);
98 if (extent_buffer_cache
)
99 kmem_cache_destroy(extent_buffer_cache
);
102 void extent_io_tree_init(struct extent_io_tree
*tree
,
103 struct address_space
*mapping
, gfp_t mask
)
105 tree
->state
.rb_node
= NULL
;
106 tree
->buffer
.rb_node
= NULL
;
108 tree
->dirty_bytes
= 0;
109 spin_lock_init(&tree
->lock
);
110 spin_lock_init(&tree
->buffer_lock
);
111 tree
->mapping
= mapping
;
113 EXPORT_SYMBOL(extent_io_tree_init
);
115 static struct extent_state
*alloc_extent_state(gfp_t mask
)
117 struct extent_state
*state
;
122 state
= kmem_cache_alloc(extent_state_cache
, mask
);
129 spin_lock_irqsave(&leak_lock
, flags
);
130 list_add(&state
->leak_list
, &states
);
131 spin_unlock_irqrestore(&leak_lock
, flags
);
133 atomic_set(&state
->refs
, 1);
134 init_waitqueue_head(&state
->wq
);
137 EXPORT_SYMBOL(alloc_extent_state
);
139 static void free_extent_state(struct extent_state
*state
)
143 if (atomic_dec_and_test(&state
->refs
)) {
147 WARN_ON(state
->tree
);
149 spin_lock_irqsave(&leak_lock
, flags
);
150 list_del(&state
->leak_list
);
151 spin_unlock_irqrestore(&leak_lock
, flags
);
153 kmem_cache_free(extent_state_cache
, state
);
156 EXPORT_SYMBOL(free_extent_state
);
158 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
159 struct rb_node
*node
)
161 struct rb_node
** p
= &root
->rb_node
;
162 struct rb_node
* parent
= NULL
;
163 struct tree_entry
*entry
;
167 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
169 if (offset
< entry
->start
)
171 else if (offset
> entry
->end
)
177 entry
= rb_entry(node
, struct tree_entry
, rb_node
);
178 rb_link_node(node
, parent
, p
);
179 rb_insert_color(node
, root
);
183 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
184 struct rb_node
**prev_ret
,
185 struct rb_node
**next_ret
)
187 struct rb_root
*root
= &tree
->state
;
188 struct rb_node
* n
= root
->rb_node
;
189 struct rb_node
*prev
= NULL
;
190 struct rb_node
*orig_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
)
210 while(prev
&& offset
> prev_entry
->end
) {
211 prev
= rb_next(prev
);
212 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
219 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
220 while(prev
&& offset
< prev_entry
->start
) {
221 prev
= rb_prev(prev
);
222 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
229 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
232 struct rb_node
*prev
= NULL
;
235 ret
= __etree_search(tree
, offset
, &prev
, NULL
);
242 static struct extent_buffer
*buffer_tree_insert(struct extent_io_tree
*tree
,
243 u64 offset
, struct rb_node
*node
)
245 struct rb_root
*root
= &tree
->buffer
;
246 struct rb_node
** p
= &root
->rb_node
;
247 struct rb_node
* parent
= NULL
;
248 struct extent_buffer
*eb
;
252 eb
= rb_entry(parent
, struct extent_buffer
, rb_node
);
254 if (offset
< eb
->start
)
256 else if (offset
> eb
->start
)
262 rb_link_node(node
, parent
, p
);
263 rb_insert_color(node
, root
);
267 static struct extent_buffer
*buffer_search(struct extent_io_tree
*tree
,
270 struct rb_root
*root
= &tree
->buffer
;
271 struct rb_node
* n
= root
->rb_node
;
272 struct extent_buffer
*eb
;
275 eb
= rb_entry(n
, struct extent_buffer
, rb_node
);
276 if (offset
< eb
->start
)
278 else if (offset
> eb
->start
)
287 * utility function to look for merge candidates inside a given range.
288 * Any extents with matching state are merged together into a single
289 * extent in the tree. Extents with EXTENT_IO in their state field
290 * are not merged because the end_io handlers need to be able to do
291 * operations on them without sleeping (or doing allocations/splits).
293 * This should be called with the tree lock held.
295 static int merge_state(struct extent_io_tree
*tree
,
296 struct extent_state
*state
)
298 struct extent_state
*other
;
299 struct rb_node
*other_node
;
301 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
304 other_node
= rb_prev(&state
->rb_node
);
306 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
307 if (other
->end
== state
->start
- 1 &&
308 other
->state
== state
->state
) {
309 state
->start
= other
->start
;
311 rb_erase(&other
->rb_node
, &tree
->state
);
312 free_extent_state(other
);
315 other_node
= rb_next(&state
->rb_node
);
317 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
318 if (other
->start
== state
->end
+ 1 &&
319 other
->state
== state
->state
) {
320 other
->start
= state
->start
;
322 rb_erase(&state
->rb_node
, &tree
->state
);
323 free_extent_state(state
);
329 static void set_state_cb(struct extent_io_tree
*tree
,
330 struct extent_state
*state
,
333 if (tree
->ops
&& tree
->ops
->set_bit_hook
) {
334 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
->start
,
335 state
->end
, state
->state
, bits
);
339 static void clear_state_cb(struct extent_io_tree
*tree
,
340 struct extent_state
*state
,
343 if (tree
->ops
&& tree
->ops
->clear_bit_hook
) {
344 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
->start
,
345 state
->end
, state
->state
, bits
);
350 * insert an extent_state struct into the tree. 'bits' are set on the
351 * struct before it is inserted.
353 * This may return -EEXIST if the extent is already there, in which case the
354 * state struct is freed.
356 * The tree lock is not taken internally. This is a utility function and
357 * probably isn't what you want to call (see set/clear_extent_bit).
359 static int insert_state(struct extent_io_tree
*tree
,
360 struct extent_state
*state
, u64 start
, u64 end
,
363 struct rb_node
*node
;
366 printk("end < start %Lu %Lu\n", end
, start
);
369 if (bits
& EXTENT_DIRTY
)
370 tree
->dirty_bytes
+= end
- start
+ 1;
371 set_state_cb(tree
, state
, bits
);
372 state
->state
|= bits
;
373 state
->start
= start
;
375 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
377 struct extent_state
*found
;
378 found
= rb_entry(node
, struct extent_state
, rb_node
);
379 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found
->start
, found
->end
, start
, end
);
380 free_extent_state(state
);
384 merge_state(tree
, state
);
389 * split a given extent state struct in two, inserting the preallocated
390 * struct 'prealloc' as the newly created second half. 'split' indicates an
391 * offset inside 'orig' where it should be split.
394 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
395 * are two extent state structs in the tree:
396 * prealloc: [orig->start, split - 1]
397 * orig: [ split, orig->end ]
399 * The tree locks are not taken by this function. They need to be held
402 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
403 struct extent_state
*prealloc
, u64 split
)
405 struct rb_node
*node
;
406 prealloc
->start
= orig
->start
;
407 prealloc
->end
= split
- 1;
408 prealloc
->state
= orig
->state
;
411 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
413 struct extent_state
*found
;
414 found
= rb_entry(node
, struct extent_state
, rb_node
);
415 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found
->start
, found
->end
, prealloc
->start
, prealloc
->end
);
416 free_extent_state(prealloc
);
419 prealloc
->tree
= tree
;
424 * utility function to clear some bits in an extent state struct.
425 * it will optionally wake up any one waiting on this state (wake == 1), or
426 * forcibly remove the state from the tree (delete == 1).
428 * If no bits are set on the state struct after clearing things, the
429 * struct is freed and removed from the tree
431 static int clear_state_bit(struct extent_io_tree
*tree
,
432 struct extent_state
*state
, int bits
, int wake
,
435 int ret
= state
->state
& bits
;
437 if ((bits
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
438 u64 range
= state
->end
- state
->start
+ 1;
439 WARN_ON(range
> tree
->dirty_bytes
);
440 tree
->dirty_bytes
-= range
;
442 clear_state_cb(tree
, state
, bits
);
443 state
->state
&= ~bits
;
446 if (delete || state
->state
== 0) {
448 clear_state_cb(tree
, state
, state
->state
);
449 rb_erase(&state
->rb_node
, &tree
->state
);
451 free_extent_state(state
);
456 merge_state(tree
, state
);
462 * clear some bits on a range in the tree. This may require splitting
463 * or inserting elements in the tree, so the gfp mask is used to
464 * indicate which allocations or sleeping are allowed.
466 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
467 * the given range from the tree regardless of state (ie for truncate).
469 * the range [start, end] is inclusive.
471 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
472 * bits were already set, or zero if none of the bits were already set.
474 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
475 int bits
, int wake
, int delete, gfp_t mask
)
477 struct extent_state
*state
;
478 struct extent_state
*prealloc
= NULL
;
479 struct rb_node
*node
;
484 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
485 prealloc
= alloc_extent_state(mask
);
490 spin_lock(&tree
->lock
);
492 * this search will find the extents that end after
495 node
= tree_search(tree
, start
);
498 state
= rb_entry(node
, struct extent_state
, rb_node
);
499 if (state
->start
> end
)
501 WARN_ON(state
->end
< start
);
504 * | ---- desired range ---- |
506 * | ------------- state -------------- |
508 * We need to split the extent we found, and may flip
509 * bits on second half.
511 * If the extent we found extends past our range, we
512 * just split and search again. It'll get split again
513 * the next time though.
515 * If the extent we found is inside our range, we clear
516 * the desired bit on it.
519 if (state
->start
< start
) {
521 prealloc
= alloc_extent_state(GFP_ATOMIC
);
522 err
= split_state(tree
, state
, prealloc
, start
);
523 BUG_ON(err
== -EEXIST
);
527 if (state
->end
<= end
) {
528 start
= state
->end
+ 1;
529 set
|= clear_state_bit(tree
, state
, bits
,
532 start
= state
->start
;
537 * | ---- desired range ---- |
539 * We need to split the extent, and clear the bit
542 if (state
->start
<= end
&& state
->end
> end
) {
544 prealloc
= alloc_extent_state(GFP_ATOMIC
);
545 err
= split_state(tree
, state
, prealloc
, end
+ 1);
546 BUG_ON(err
== -EEXIST
);
550 set
|= clear_state_bit(tree
, prealloc
, bits
,
556 start
= state
->end
+ 1;
557 set
|= clear_state_bit(tree
, state
, bits
, wake
, delete);
561 spin_unlock(&tree
->lock
);
563 free_extent_state(prealloc
);
570 spin_unlock(&tree
->lock
);
571 if (mask
& __GFP_WAIT
)
575 EXPORT_SYMBOL(clear_extent_bit
);
577 static int wait_on_state(struct extent_io_tree
*tree
,
578 struct extent_state
*state
)
579 __releases(tree
->lock
)
580 __acquires(tree
->lock
)
583 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
584 spin_unlock(&tree
->lock
);
586 spin_lock(&tree
->lock
);
587 finish_wait(&state
->wq
, &wait
);
592 * waits for one or more bits to clear on a range in the state tree.
593 * The range [start, end] is inclusive.
594 * The tree lock is taken by this function
596 int wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
, int bits
)
598 struct extent_state
*state
;
599 struct rb_node
*node
;
601 spin_lock(&tree
->lock
);
605 * this search will find all the extents that end after
608 node
= tree_search(tree
, start
);
612 state
= rb_entry(node
, struct extent_state
, rb_node
);
614 if (state
->start
> end
)
617 if (state
->state
& bits
) {
618 start
= state
->start
;
619 atomic_inc(&state
->refs
);
620 wait_on_state(tree
, state
);
621 free_extent_state(state
);
624 start
= state
->end
+ 1;
629 if (need_resched()) {
630 spin_unlock(&tree
->lock
);
632 spin_lock(&tree
->lock
);
636 spin_unlock(&tree
->lock
);
639 EXPORT_SYMBOL(wait_extent_bit
);
641 static void set_state_bits(struct extent_io_tree
*tree
,
642 struct extent_state
*state
,
645 if ((bits
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
646 u64 range
= state
->end
- state
->start
+ 1;
647 tree
->dirty_bytes
+= range
;
649 set_state_cb(tree
, state
, bits
);
650 state
->state
|= bits
;
654 * set some bits on a range in the tree. This may require allocations
655 * or sleeping, so the gfp mask is used to indicate what is allowed.
657 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
658 * range already has the desired bits set. The start of the existing
659 * range is returned in failed_start in this case.
661 * [start, end] is inclusive
662 * This takes the tree lock.
664 static int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
, int bits
,
665 int exclusive
, u64
*failed_start
, gfp_t mask
)
667 struct extent_state
*state
;
668 struct extent_state
*prealloc
= NULL
;
669 struct rb_node
*node
;
675 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
676 prealloc
= alloc_extent_state(mask
);
681 spin_lock(&tree
->lock
);
683 * this search will find all the extents that end after
686 node
= tree_search(tree
, start
);
688 err
= insert_state(tree
, prealloc
, start
, end
, bits
);
690 BUG_ON(err
== -EEXIST
);
694 state
= rb_entry(node
, struct extent_state
, rb_node
);
695 last_start
= state
->start
;
696 last_end
= state
->end
;
699 * | ---- desired range ---- |
702 * Just lock what we found and keep going
704 if (state
->start
== start
&& state
->end
<= end
) {
705 set
= state
->state
& bits
;
706 if (set
&& exclusive
) {
707 *failed_start
= state
->start
;
711 set_state_bits(tree
, state
, bits
);
712 start
= state
->end
+ 1;
713 merge_state(tree
, state
);
718 * | ---- desired range ---- |
721 * | ------------- state -------------- |
723 * We need to split the extent we found, and may flip bits on
726 * If the extent we found extends past our
727 * range, we just split and search again. It'll get split
728 * again the next time though.
730 * If the extent we found is inside our range, we set the
733 if (state
->start
< start
) {
734 set
= state
->state
& bits
;
735 if (exclusive
&& set
) {
736 *failed_start
= start
;
740 err
= split_state(tree
, state
, prealloc
, start
);
741 BUG_ON(err
== -EEXIST
);
745 if (state
->end
<= end
) {
746 set_state_bits(tree
, state
, bits
);
747 start
= state
->end
+ 1;
748 merge_state(tree
, state
);
750 start
= state
->start
;
755 * | ---- desired range ---- |
756 * | state | or | state |
758 * There's a hole, we need to insert something in it and
759 * ignore the extent we found.
761 if (state
->start
> start
) {
763 if (end
< last_start
)
766 this_end
= last_start
-1;
767 err
= insert_state(tree
, prealloc
, start
, this_end
,
770 BUG_ON(err
== -EEXIST
);
773 start
= this_end
+ 1;
777 * | ---- desired range ---- |
779 * We need to split the extent, and set the bit
782 if (state
->start
<= end
&& state
->end
> end
) {
783 set
= state
->state
& bits
;
784 if (exclusive
&& set
) {
785 *failed_start
= start
;
789 err
= split_state(tree
, state
, prealloc
, end
+ 1);
790 BUG_ON(err
== -EEXIST
);
792 set_state_bits(tree
, prealloc
, bits
);
793 merge_state(tree
, prealloc
);
801 spin_unlock(&tree
->lock
);
803 free_extent_state(prealloc
);
810 spin_unlock(&tree
->lock
);
811 if (mask
& __GFP_WAIT
)
815 EXPORT_SYMBOL(set_extent_bit
);
817 /* wrappers around set/clear extent bit */
818 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
821 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, 0, NULL
,
824 EXPORT_SYMBOL(set_extent_dirty
);
826 int set_extent_ordered(struct extent_io_tree
*tree
, u64 start
, u64 end
,
829 return set_extent_bit(tree
, start
, end
, EXTENT_ORDERED
, 0, NULL
, mask
);
831 EXPORT_SYMBOL(set_extent_ordered
);
833 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
834 int bits
, gfp_t mask
)
836 return set_extent_bit(tree
, start
, end
, bits
, 0, NULL
,
839 EXPORT_SYMBOL(set_extent_bits
);
841 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
842 int bits
, gfp_t mask
)
844 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, mask
);
846 EXPORT_SYMBOL(clear_extent_bits
);
848 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
851 return set_extent_bit(tree
, start
, end
,
852 EXTENT_DELALLOC
| EXTENT_DIRTY
,
855 EXPORT_SYMBOL(set_extent_delalloc
);
857 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
860 return clear_extent_bit(tree
, start
, end
,
861 EXTENT_DIRTY
| EXTENT_DELALLOC
, 0, 0, mask
);
863 EXPORT_SYMBOL(clear_extent_dirty
);
865 int clear_extent_ordered(struct extent_io_tree
*tree
, u64 start
, u64 end
,
868 return clear_extent_bit(tree
, start
, end
, EXTENT_ORDERED
, 1, 0, mask
);
870 EXPORT_SYMBOL(clear_extent_ordered
);
872 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
875 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, NULL
,
878 EXPORT_SYMBOL(set_extent_new
);
880 static int clear_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
883 return clear_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, 0, mask
);
886 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
889 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, NULL
,
892 EXPORT_SYMBOL(set_extent_uptodate
);
894 static int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
897 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0, mask
);
900 static int set_extent_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
,
903 return set_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
,
907 static int clear_extent_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
,
910 return clear_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
, 1, 0, mask
);
913 int wait_on_extent_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
915 return wait_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
);
917 EXPORT_SYMBOL(wait_on_extent_writeback
);
920 * either insert or lock state struct between start and end use mask to tell
921 * us if waiting is desired.
923 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
, gfp_t mask
)
928 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1,
929 &failed_start
, mask
);
930 if (err
== -EEXIST
&& (mask
& __GFP_WAIT
)) {
931 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
932 start
= failed_start
;
936 WARN_ON(start
> end
);
940 EXPORT_SYMBOL(lock_extent
);
942 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
,
948 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1,
949 &failed_start
, mask
);
950 if (err
== -EEXIST
) {
951 if (failed_start
> start
)
952 clear_extent_bit(tree
, start
, failed_start
- 1,
953 EXTENT_LOCKED
, 1, 0, mask
);
958 EXPORT_SYMBOL(try_lock_extent
);
960 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
,
963 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, mask
);
965 EXPORT_SYMBOL(unlock_extent
);
968 * helper function to set pages and extents in the tree dirty
970 int set_range_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
)
972 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
973 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
976 while (index
<= end_index
) {
977 page
= find_get_page(tree
->mapping
, index
);
979 __set_page_dirty_nobuffers(page
);
980 page_cache_release(page
);
983 set_extent_dirty(tree
, start
, end
, GFP_NOFS
);
986 EXPORT_SYMBOL(set_range_dirty
);
989 * helper function to set both pages and extents in the tree writeback
991 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
993 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
994 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
997 while (index
<= end_index
) {
998 page
= find_get_page(tree
->mapping
, index
);
1000 set_page_writeback(page
);
1001 page_cache_release(page
);
1004 set_extent_writeback(tree
, start
, end
, GFP_NOFS
);
1009 * find the first offset in the io tree with 'bits' set. zero is
1010 * returned if we find something, and *start_ret and *end_ret are
1011 * set to reflect the state struct that was found.
1013 * If nothing was found, 1 is returned, < 0 on error
1015 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1016 u64
*start_ret
, u64
*end_ret
, int bits
)
1018 struct rb_node
*node
;
1019 struct extent_state
*state
;
1022 spin_lock(&tree
->lock
);
1024 * this search will find all the extents that end after
1027 node
= tree_search(tree
, start
);
1033 state
= rb_entry(node
, struct extent_state
, rb_node
);
1034 if (state
->end
>= start
&& (state
->state
& bits
)) {
1035 *start_ret
= state
->start
;
1036 *end_ret
= state
->end
;
1040 node
= rb_next(node
);
1045 spin_unlock(&tree
->lock
);
1048 EXPORT_SYMBOL(find_first_extent_bit
);
1050 /* find the first state struct with 'bits' set after 'start', and
1051 * return it. tree->lock must be held. NULL will returned if
1052 * nothing was found after 'start'
1054 struct extent_state
*find_first_extent_bit_state(struct extent_io_tree
*tree
,
1055 u64 start
, int bits
)
1057 struct rb_node
*node
;
1058 struct extent_state
*state
;
1061 * this search will find all the extents that end after
1064 node
= tree_search(tree
, start
);
1070 state
= rb_entry(node
, struct extent_state
, rb_node
);
1071 if (state
->end
>= start
&& (state
->state
& bits
)) {
1074 node
= rb_next(node
);
1081 EXPORT_SYMBOL(find_first_extent_bit_state
);
1084 * find a contiguous range of bytes in the file marked as delalloc, not
1085 * more than 'max_bytes'. start and end are used to return the range,
1087 * 1 is returned if we find something, 0 if nothing was in the tree
1089 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1090 u64
*start
, u64
*end
, u64 max_bytes
)
1092 struct rb_node
*node
;
1093 struct extent_state
*state
;
1094 u64 cur_start
= *start
;
1096 u64 total_bytes
= 0;
1098 spin_lock(&tree
->lock
);
1101 * this search will find all the extents that end after
1104 node
= tree_search(tree
, cur_start
);
1112 state
= rb_entry(node
, struct extent_state
, rb_node
);
1113 if (found
&& (state
->start
!= cur_start
||
1114 (state
->state
& EXTENT_BOUNDARY
))) {
1117 if (!(state
->state
& EXTENT_DELALLOC
)) {
1123 *start
= state
->start
;
1126 cur_start
= state
->end
+ 1;
1127 node
= rb_next(node
);
1130 total_bytes
+= state
->end
- state
->start
+ 1;
1131 if (total_bytes
>= max_bytes
)
1135 spin_unlock(&tree
->lock
);
1139 static noinline
int __unlock_for_delalloc(struct inode
*inode
,
1140 struct page
*locked_page
,
1144 struct page
*pages
[16];
1145 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1146 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1147 unsigned long nr_pages
= end_index
- index
+ 1;
1150 if (index
== locked_page
->index
&& end_index
== index
)
1153 while(nr_pages
> 0) {
1154 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1155 min_t(unsigned long, nr_pages
,
1156 ARRAY_SIZE(pages
)), pages
);
1157 for (i
= 0; i
< ret
; i
++) {
1158 if (pages
[i
] != locked_page
)
1159 unlock_page(pages
[i
]);
1160 page_cache_release(pages
[i
]);
1169 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1170 struct page
*locked_page
,
1174 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1175 unsigned long start_index
= index
;
1176 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1177 unsigned long pages_locked
= 0;
1178 struct page
*pages
[16];
1179 unsigned long nrpages
;
1183 /* the caller is responsible for locking the start index */
1184 if (index
== locked_page
->index
&& index
== end_index
)
1187 /* skip the page at the start index */
1188 nrpages
= end_index
- index
+ 1;
1189 while(nrpages
> 0) {
1190 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1191 min_t(unsigned long,
1192 nrpages
, ARRAY_SIZE(pages
)), pages
);
1197 /* now we have an array of pages, lock them all */
1198 for (i
= 0; i
< ret
; i
++) {
1200 * the caller is taking responsibility for
1203 if (pages
[i
] != locked_page
) {
1204 lock_page(pages
[i
]);
1205 if (!PageDirty(pages
[i
]) ||
1206 pages
[i
]->mapping
!= inode
->i_mapping
) {
1208 unlock_page(pages
[i
]);
1209 page_cache_release(pages
[i
]);
1213 page_cache_release(pages
[i
]);
1222 if (ret
&& pages_locked
) {
1223 __unlock_for_delalloc(inode
, locked_page
,
1225 ((u64
)(start_index
+ pages_locked
- 1)) <<
1232 * find a contiguous range of bytes in the file marked as delalloc, not
1233 * more than 'max_bytes'. start and end are used to return the range,
1235 * 1 is returned if we find something, 0 if nothing was in the tree
1237 static noinline u64
find_lock_delalloc_range(struct inode
*inode
,
1238 struct extent_io_tree
*tree
,
1239 struct page
*locked_page
,
1240 u64
*start
, u64
*end
,
1250 /* step one, find a bunch of delalloc bytes starting at start */
1251 delalloc_start
= *start
;
1253 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1255 if (!found
|| delalloc_end
<= *start
) {
1256 *start
= delalloc_start
;
1257 *end
= delalloc_end
;
1262 * start comes from the offset of locked_page. We have to lock
1263 * pages in order, so we can't process delalloc bytes before
1266 if (delalloc_start
< *start
) {
1267 delalloc_start
= *start
;
1271 * make sure to limit the number of pages we try to lock down
1274 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
&& loops
) {
1275 delalloc_end
= delalloc_start
+ PAGE_CACHE_SIZE
- 1;
1277 /* step two, lock all the pages after the page that has start */
1278 ret
= lock_delalloc_pages(inode
, locked_page
,
1279 delalloc_start
, delalloc_end
);
1280 if (ret
== -EAGAIN
) {
1281 /* some of the pages are gone, lets avoid looping by
1282 * shortening the size of the delalloc range we're searching
1285 unsigned long offset
= (*start
) & (PAGE_CACHE_SIZE
- 1);
1286 max_bytes
= PAGE_CACHE_SIZE
- offset
;
1296 /* step three, lock the state bits for the whole range */
1297 lock_extent(tree
, delalloc_start
, delalloc_end
, GFP_NOFS
);
1299 /* then test to make sure it is all still delalloc */
1300 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1301 EXTENT_DELALLOC
, 1);
1303 unlock_extent(tree
, delalloc_start
, delalloc_end
, GFP_NOFS
);
1304 __unlock_for_delalloc(inode
, locked_page
,
1305 delalloc_start
, delalloc_end
);
1309 *start
= delalloc_start
;
1310 *end
= delalloc_end
;
1315 int extent_clear_unlock_delalloc(struct inode
*inode
,
1316 struct extent_io_tree
*tree
,
1317 u64 start
, u64 end
, struct page
*locked_page
,
1320 int clear_delalloc
, int clear_dirty
,
1325 struct page
*pages
[16];
1326 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1327 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1328 unsigned long nr_pages
= end_index
- index
+ 1;
1333 clear_bits
|= EXTENT_LOCKED
;
1335 clear_bits
|= EXTENT_DIRTY
;
1338 clear_bits
|= EXTENT_DELALLOC
;
1340 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, GFP_NOFS
);
1341 if (!(unlock_pages
|| clear_dirty
|| set_writeback
|| end_writeback
))
1344 while(nr_pages
> 0) {
1345 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1346 min_t(unsigned long,
1347 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1348 for (i
= 0; i
< ret
; i
++) {
1349 if (pages
[i
] == locked_page
) {
1350 page_cache_release(pages
[i
]);
1354 clear_page_dirty_for_io(pages
[i
]);
1356 set_page_writeback(pages
[i
]);
1358 end_page_writeback(pages
[i
]);
1360 unlock_page(pages
[i
]);
1361 page_cache_release(pages
[i
]);
1369 EXPORT_SYMBOL(extent_clear_unlock_delalloc
);
1372 * count the number of bytes in the tree that have a given bit(s)
1373 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1374 * cached. The total number found is returned.
1376 u64
count_range_bits(struct extent_io_tree
*tree
,
1377 u64
*start
, u64 search_end
, u64 max_bytes
,
1380 struct rb_node
*node
;
1381 struct extent_state
*state
;
1382 u64 cur_start
= *start
;
1383 u64 total_bytes
= 0;
1386 if (search_end
<= cur_start
) {
1387 printk("search_end %Lu start %Lu\n", search_end
, cur_start
);
1392 spin_lock(&tree
->lock
);
1393 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1394 total_bytes
= tree
->dirty_bytes
;
1398 * this search will find all the extents that end after
1401 node
= tree_search(tree
, cur_start
);
1407 state
= rb_entry(node
, struct extent_state
, rb_node
);
1408 if (state
->start
> search_end
)
1410 if (state
->end
>= cur_start
&& (state
->state
& bits
)) {
1411 total_bytes
+= min(search_end
, state
->end
) + 1 -
1412 max(cur_start
, state
->start
);
1413 if (total_bytes
>= max_bytes
)
1416 *start
= state
->start
;
1420 node
= rb_next(node
);
1425 spin_unlock(&tree
->lock
);
1431 * helper function to lock both pages and extents in the tree.
1432 * pages must be locked first.
1434 static int lock_range(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1436 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1437 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1441 while (index
<= end_index
) {
1442 page
= grab_cache_page(tree
->mapping
, index
);
1448 err
= PTR_ERR(page
);
1453 lock_extent(tree
, start
, end
, GFP_NOFS
);
1458 * we failed above in getting the page at 'index', so we undo here
1459 * up to but not including the page at 'index'
1462 index
= start
>> PAGE_CACHE_SHIFT
;
1463 while (index
< end_index
) {
1464 page
= find_get_page(tree
->mapping
, index
);
1466 page_cache_release(page
);
1473 * helper function to unlock both pages and extents in the tree.
1475 static int unlock_range(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1477 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1478 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1481 while (index
<= end_index
) {
1482 page
= find_get_page(tree
->mapping
, index
);
1484 page_cache_release(page
);
1487 unlock_extent(tree
, start
, end
, GFP_NOFS
);
1493 * set the private field for a given byte offset in the tree. If there isn't
1494 * an extent_state there already, this does nothing.
1496 int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1498 struct rb_node
*node
;
1499 struct extent_state
*state
;
1502 spin_lock(&tree
->lock
);
1504 * this search will find all the extents that end after
1507 node
= tree_search(tree
, start
);
1512 state
= rb_entry(node
, struct extent_state
, rb_node
);
1513 if (state
->start
!= start
) {
1517 state
->private = private;
1519 spin_unlock(&tree
->lock
);
1523 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1525 struct rb_node
*node
;
1526 struct extent_state
*state
;
1529 spin_lock(&tree
->lock
);
1531 * this search will find all the extents that end after
1534 node
= tree_search(tree
, start
);
1539 state
= rb_entry(node
, struct extent_state
, rb_node
);
1540 if (state
->start
!= start
) {
1544 *private = state
->private;
1546 spin_unlock(&tree
->lock
);
1551 * searches a range in the state tree for a given mask.
1552 * If 'filled' == 1, this returns 1 only if every extent in the tree
1553 * has the bits set. Otherwise, 1 is returned if any bit in the
1554 * range is found set.
1556 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1557 int bits
, int filled
)
1559 struct extent_state
*state
= NULL
;
1560 struct rb_node
*node
;
1563 spin_lock(&tree
->lock
);
1564 node
= tree_search(tree
, start
);
1565 while (node
&& start
<= end
) {
1566 state
= rb_entry(node
, struct extent_state
, rb_node
);
1568 if (filled
&& state
->start
> start
) {
1573 if (state
->start
> end
)
1576 if (state
->state
& bits
) {
1580 } else if (filled
) {
1584 start
= state
->end
+ 1;
1587 node
= rb_next(node
);
1594 spin_unlock(&tree
->lock
);
1597 EXPORT_SYMBOL(test_range_bit
);
1600 * helper function to set a given page up to date if all the
1601 * extents in the tree for that page are up to date
1603 static int check_page_uptodate(struct extent_io_tree
*tree
,
1606 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1607 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1608 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1))
1609 SetPageUptodate(page
);
1614 * helper function to unlock a page if all the extents in the tree
1615 * for that page are unlocked
1617 static int check_page_locked(struct extent_io_tree
*tree
,
1620 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1621 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1622 if (!test_range_bit(tree
, start
, end
, EXTENT_LOCKED
, 0))
1628 * helper function to end page writeback if all the extents
1629 * in the tree for that page are done with writeback
1631 static int check_page_writeback(struct extent_io_tree
*tree
,
1634 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1635 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1636 if (!test_range_bit(tree
, start
, end
, EXTENT_WRITEBACK
, 0))
1637 end_page_writeback(page
);
1641 /* lots and lots of room for performance fixes in the end_bio funcs */
1644 * after a writepage IO is done, we need to:
1645 * clear the uptodate bits on error
1646 * clear the writeback bits in the extent tree for this IO
1647 * end_page_writeback if the page has no more pending IO
1649 * Scheduling is not allowed, so the extent state tree is expected
1650 * to have one and only one object corresponding to this IO.
1652 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
1654 int uptodate
= err
== 0;
1655 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1656 struct extent_io_tree
*tree
;
1663 struct page
*page
= bvec
->bv_page
;
1664 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1666 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1668 end
= start
+ bvec
->bv_len
- 1;
1670 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1675 if (--bvec
>= bio
->bi_io_vec
)
1676 prefetchw(&bvec
->bv_page
->flags
);
1677 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
1678 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
1679 end
, NULL
, uptodate
);
1684 if (!uptodate
&& tree
->ops
&&
1685 tree
->ops
->writepage_io_failed_hook
) {
1686 ret
= tree
->ops
->writepage_io_failed_hook(bio
, page
,
1689 uptodate
= (err
== 0);
1695 clear_extent_uptodate(tree
, start
, end
, GFP_ATOMIC
);
1696 ClearPageUptodate(page
);
1700 clear_extent_writeback(tree
, start
, end
, GFP_ATOMIC
);
1703 end_page_writeback(page
);
1705 check_page_writeback(tree
, page
);
1706 } while (bvec
>= bio
->bi_io_vec
);
1712 * after a readpage IO is done, we need to:
1713 * clear the uptodate bits on error
1714 * set the uptodate bits if things worked
1715 * set the page up to date if all extents in the tree are uptodate
1716 * clear the lock bit in the extent tree
1717 * unlock the page if there are no other extents locked for it
1719 * Scheduling is not allowed, so the extent state tree is expected
1720 * to have one and only one object corresponding to this IO.
1722 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
1724 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1725 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1726 struct extent_io_tree
*tree
;
1736 struct page
*page
= bvec
->bv_page
;
1737 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1739 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1741 end
= start
+ bvec
->bv_len
- 1;
1743 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1748 if (--bvec
>= bio
->bi_io_vec
)
1749 prefetchw(&bvec
->bv_page
->flags
);
1751 if (uptodate
&& tree
->ops
&& tree
->ops
->readpage_end_io_hook
) {
1752 ret
= tree
->ops
->readpage_end_io_hook(page
, start
, end
,
1757 if (!uptodate
&& tree
->ops
&&
1758 tree
->ops
->readpage_io_failed_hook
) {
1759 ret
= tree
->ops
->readpage_io_failed_hook(bio
, page
,
1763 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1771 set_extent_uptodate(tree
, start
, end
,
1774 unlock_extent(tree
, start
, end
, GFP_ATOMIC
);
1778 SetPageUptodate(page
);
1780 ClearPageUptodate(page
);
1786 check_page_uptodate(tree
, page
);
1788 ClearPageUptodate(page
);
1791 check_page_locked(tree
, page
);
1793 } while (bvec
>= bio
->bi_io_vec
);
1799 * IO done from prepare_write is pretty simple, we just unlock
1800 * the structs in the extent tree when done, and set the uptodate bits
1803 static void end_bio_extent_preparewrite(struct bio
*bio
, int err
)
1805 const int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1806 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1807 struct extent_io_tree
*tree
;
1812 struct page
*page
= bvec
->bv_page
;
1813 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1815 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1817 end
= start
+ bvec
->bv_len
- 1;
1819 if (--bvec
>= bio
->bi_io_vec
)
1820 prefetchw(&bvec
->bv_page
->flags
);
1823 set_extent_uptodate(tree
, start
, end
, GFP_ATOMIC
);
1825 ClearPageUptodate(page
);
1829 unlock_extent(tree
, start
, end
, GFP_ATOMIC
);
1831 } while (bvec
>= bio
->bi_io_vec
);
1837 extent_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
1842 bio
= bio_alloc(gfp_flags
, nr_vecs
);
1844 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
1845 while (!bio
&& (nr_vecs
/= 2))
1846 bio
= bio_alloc(gfp_flags
, nr_vecs
);
1851 bio
->bi_bdev
= bdev
;
1852 bio
->bi_sector
= first_sector
;
1857 static int submit_one_bio(int rw
, struct bio
*bio
, int mirror_num
,
1858 unsigned long bio_flags
)
1861 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1862 struct page
*page
= bvec
->bv_page
;
1863 struct extent_io_tree
*tree
= bio
->bi_private
;
1867 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) + bvec
->bv_offset
;
1868 end
= start
+ bvec
->bv_len
- 1;
1870 bio
->bi_private
= NULL
;
1874 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
1875 tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
1876 mirror_num
, bio_flags
);
1878 submit_bio(rw
, bio
);
1879 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
1885 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
1886 struct page
*page
, sector_t sector
,
1887 size_t size
, unsigned long offset
,
1888 struct block_device
*bdev
,
1889 struct bio
**bio_ret
,
1890 unsigned long max_pages
,
1891 bio_end_io_t end_io_func
,
1893 unsigned long prev_bio_flags
,
1894 unsigned long bio_flags
)
1900 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
1901 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
1902 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
1904 if (bio_ret
&& *bio_ret
) {
1907 contig
= bio
->bi_sector
== sector
;
1909 contig
= bio
->bi_sector
+ (bio
->bi_size
>> 9) ==
1912 if (prev_bio_flags
!= bio_flags
|| !contig
||
1913 (tree
->ops
&& tree
->ops
->merge_bio_hook
&&
1914 tree
->ops
->merge_bio_hook(page
, offset
, page_size
, bio
,
1916 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
1917 ret
= submit_one_bio(rw
, bio
, mirror_num
,
1924 if (this_compressed
)
1927 nr
= bio_get_nr_vecs(bdev
);
1929 bio
= extent_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
1931 printk("failed to allocate bio nr %d\n", nr
);
1934 bio_add_page(bio
, page
, page_size
, offset
);
1935 bio
->bi_end_io
= end_io_func
;
1936 bio
->bi_private
= tree
;
1941 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
1947 void set_page_extent_mapped(struct page
*page
)
1949 if (!PagePrivate(page
)) {
1950 SetPagePrivate(page
);
1951 page_cache_get(page
);
1952 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
1955 EXPORT_SYMBOL(set_page_extent_mapped
);
1957 static void set_page_extent_head(struct page
*page
, unsigned long len
)
1959 set_page_private(page
, EXTENT_PAGE_PRIVATE_FIRST_PAGE
| len
<< 2);
1963 * basic readpage implementation. Locked extent state structs are inserted
1964 * into the tree that are removed when the IO is done (by the end_io
1967 static int __extent_read_full_page(struct extent_io_tree
*tree
,
1969 get_extent_t
*get_extent
,
1970 struct bio
**bio
, int mirror_num
,
1971 unsigned long *bio_flags
)
1973 struct inode
*inode
= page
->mapping
->host
;
1974 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1975 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
1979 u64 last_byte
= i_size_read(inode
);
1983 struct extent_map
*em
;
1984 struct block_device
*bdev
;
1987 size_t page_offset
= 0;
1989 size_t disk_io_size
;
1990 size_t blocksize
= inode
->i_sb
->s_blocksize
;
1991 unsigned long this_bio_flag
= 0;
1993 set_page_extent_mapped(page
);
1996 lock_extent(tree
, start
, end
, GFP_NOFS
);
1998 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
2000 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
2003 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
2004 userpage
= kmap_atomic(page
, KM_USER0
);
2005 memset(userpage
+ zero_offset
, 0, iosize
);
2006 flush_dcache_page(page
);
2007 kunmap_atomic(userpage
, KM_USER0
);
2010 while (cur
<= end
) {
2011 if (cur
>= last_byte
) {
2013 iosize
= PAGE_CACHE_SIZE
- page_offset
;
2014 userpage
= kmap_atomic(page
, KM_USER0
);
2015 memset(userpage
+ page_offset
, 0, iosize
);
2016 flush_dcache_page(page
);
2017 kunmap_atomic(userpage
, KM_USER0
);
2018 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2020 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2023 em
= get_extent(inode
, page
, page_offset
, cur
,
2025 if (IS_ERR(em
) || !em
) {
2027 unlock_extent(tree
, cur
, end
, GFP_NOFS
);
2030 extent_offset
= cur
- em
->start
;
2031 if (extent_map_end(em
) <= cur
) {
2032 printk("bad mapping em [%Lu %Lu] cur %Lu\n", em
->start
, extent_map_end(em
), cur
);
2034 BUG_ON(extent_map_end(em
) <= cur
);
2036 printk("2bad mapping end %Lu cur %Lu\n", end
, cur
);
2040 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
2041 this_bio_flag
= EXTENT_BIO_COMPRESSED
;
2043 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2044 cur_end
= min(extent_map_end(em
) - 1, end
);
2045 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
2046 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2047 disk_io_size
= em
->block_len
;
2048 sector
= em
->block_start
>> 9;
2050 sector
= (em
->block_start
+ extent_offset
) >> 9;
2051 disk_io_size
= iosize
;
2054 block_start
= em
->block_start
;
2055 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2056 block_start
= EXTENT_MAP_HOLE
;
2057 free_extent_map(em
);
2060 /* we've found a hole, just zero and go on */
2061 if (block_start
== EXTENT_MAP_HOLE
) {
2063 userpage
= kmap_atomic(page
, KM_USER0
);
2064 memset(userpage
+ page_offset
, 0, iosize
);
2065 flush_dcache_page(page
);
2066 kunmap_atomic(userpage
, KM_USER0
);
2068 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2070 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2072 page_offset
+= iosize
;
2075 /* the get_extent function already copied into the page */
2076 if (test_range_bit(tree
, cur
, cur_end
, EXTENT_UPTODATE
, 1)) {
2077 check_page_uptodate(tree
, page
);
2078 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2080 page_offset
+= iosize
;
2083 /* we have an inline extent but it didn't get marked up
2084 * to date. Error out
2086 if (block_start
== EXTENT_MAP_INLINE
) {
2088 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2090 page_offset
+= iosize
;
2095 if (tree
->ops
&& tree
->ops
->readpage_io_hook
) {
2096 ret
= tree
->ops
->readpage_io_hook(page
, cur
,
2100 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2102 ret
= submit_extent_page(READ
, tree
, page
,
2103 sector
, disk_io_size
, page_offset
,
2105 end_bio_extent_readpage
, mirror_num
,
2109 *bio_flags
= this_bio_flag
;
2114 page_offset
+= iosize
;
2117 if (!PageError(page
))
2118 SetPageUptodate(page
);
2124 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2125 get_extent_t
*get_extent
)
2127 struct bio
*bio
= NULL
;
2128 unsigned long bio_flags
= 0;
2131 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, 0,
2134 submit_one_bio(READ
, bio
, 0, bio_flags
);
2137 EXPORT_SYMBOL(extent_read_full_page
);
2140 * the writepage semantics are similar to regular writepage. extent
2141 * records are inserted to lock ranges in the tree, and as dirty areas
2142 * are found, they are marked writeback. Then the lock bits are removed
2143 * and the end_io handler clears the writeback ranges
2145 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
2148 struct inode
*inode
= page
->mapping
->host
;
2149 struct extent_page_data
*epd
= data
;
2150 struct extent_io_tree
*tree
= epd
->tree
;
2151 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2153 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2157 u64 last_byte
= i_size_read(inode
);
2162 struct extent_map
*em
;
2163 struct block_device
*bdev
;
2166 size_t pg_offset
= 0;
2168 loff_t i_size
= i_size_read(inode
);
2169 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2174 unsigned long nr_written
= 0;
2176 WARN_ON(!PageLocked(page
));
2177 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
2178 if (page
->index
> end_index
||
2179 (page
->index
== end_index
&& !pg_offset
)) {
2180 page
->mapping
->a_ops
->invalidatepage(page
, 0);
2185 if (page
->index
== end_index
) {
2188 userpage
= kmap_atomic(page
, KM_USER0
);
2189 memset(userpage
+ pg_offset
, 0,
2190 PAGE_CACHE_SIZE
- pg_offset
);
2191 kunmap_atomic(userpage
, KM_USER0
);
2192 flush_dcache_page(page
);
2196 set_page_extent_mapped(page
);
2198 delalloc_start
= start
;
2201 if (!epd
->extent_locked
) {
2202 while(delalloc_end
< page_end
) {
2203 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
2208 if (nr_delalloc
== 0) {
2209 delalloc_start
= delalloc_end
+ 1;
2212 tree
->ops
->fill_delalloc(inode
, page
, delalloc_start
,
2213 delalloc_end
, &page_started
,
2215 delalloc_start
= delalloc_end
+ 1;
2218 /* did the fill delalloc function already unlock and start
2223 goto update_nr_written
;
2226 lock_extent(tree
, start
, page_end
, GFP_NOFS
);
2228 unlock_start
= start
;
2230 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
2231 ret
= tree
->ops
->writepage_start_hook(page
, start
,
2233 if (ret
== -EAGAIN
) {
2234 unlock_extent(tree
, start
, page_end
, GFP_NOFS
);
2235 redirty_page_for_writepage(wbc
, page
);
2238 goto update_nr_written
;
2245 if (test_range_bit(tree
, start
, page_end
, EXTENT_DELALLOC
, 0)) {
2246 printk("found delalloc bits after lock_extent\n");
2249 if (last_byte
<= start
) {
2250 clear_extent_dirty(tree
, start
, page_end
, GFP_NOFS
);
2251 unlock_extent(tree
, start
, page_end
, GFP_NOFS
);
2252 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2253 tree
->ops
->writepage_end_io_hook(page
, start
,
2255 unlock_start
= page_end
+ 1;
2259 set_extent_uptodate(tree
, start
, page_end
, GFP_NOFS
);
2260 blocksize
= inode
->i_sb
->s_blocksize
;
2262 while (cur
<= end
) {
2263 if (cur
>= last_byte
) {
2264 clear_extent_dirty(tree
, cur
, page_end
, GFP_NOFS
);
2265 unlock_extent(tree
, unlock_start
, page_end
, GFP_NOFS
);
2266 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2267 tree
->ops
->writepage_end_io_hook(page
, cur
,
2269 unlock_start
= page_end
+ 1;
2272 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
2274 if (IS_ERR(em
) || !em
) {
2279 extent_offset
= cur
- em
->start
;
2280 BUG_ON(extent_map_end(em
) <= cur
);
2282 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2283 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
2284 sector
= (em
->block_start
+ extent_offset
) >> 9;
2286 block_start
= em
->block_start
;
2287 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
2288 free_extent_map(em
);
2292 * compressed and inline extents are written through other
2295 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
2296 block_start
== EXTENT_MAP_INLINE
) {
2297 clear_extent_dirty(tree
, cur
,
2298 cur
+ iosize
- 1, GFP_NOFS
);
2300 unlock_extent(tree
, unlock_start
, cur
+ iosize
-1,
2304 * end_io notification does not happen here for
2305 * compressed extents
2307 if (!compressed
&& tree
->ops
&&
2308 tree
->ops
->writepage_end_io_hook
)
2309 tree
->ops
->writepage_end_io_hook(page
, cur
,
2312 else if (compressed
) {
2313 /* we don't want to end_page_writeback on
2314 * a compressed extent. this happens
2321 pg_offset
+= iosize
;
2325 /* leave this out until we have a page_mkwrite call */
2326 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
2329 pg_offset
+= iosize
;
2333 clear_extent_dirty(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2334 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
2335 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
2343 unsigned long max_nr
= end_index
+ 1;
2345 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
2346 if (!PageWriteback(page
)) {
2347 printk("warning page %lu not writeback, "
2348 "cur %llu end %llu\n", page
->index
,
2349 (unsigned long long)cur
,
2350 (unsigned long long)end
);
2353 ret
= submit_extent_page(WRITE
, tree
, page
, sector
,
2354 iosize
, pg_offset
, bdev
,
2356 end_bio_extent_writepage
,
2362 pg_offset
+= iosize
;
2367 /* make sure the mapping tag for page dirty gets cleared */
2368 set_page_writeback(page
);
2369 end_page_writeback(page
);
2371 if (unlock_start
<= page_end
)
2372 unlock_extent(tree
, unlock_start
, page_end
, GFP_NOFS
);
2376 wbc
->nr_to_write
-= nr_written
;
2377 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
2378 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
2379 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
2384 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2385 * @mapping: address space structure to write
2386 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2387 * @writepage: function called for each page
2388 * @data: data passed to writepage function
2390 * If a page is already under I/O, write_cache_pages() skips it, even
2391 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2392 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2393 * and msync() need to guarantee that all the data which was dirty at the time
2394 * the call was made get new I/O started against them. If wbc->sync_mode is
2395 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2396 * existing IO to complete.
2398 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
2399 struct address_space
*mapping
,
2400 struct writeback_control
*wbc
,
2401 writepage_t writepage
, void *data
,
2402 void (*flush_fn
)(void *))
2404 struct backing_dev_info
*bdi
= mapping
->backing_dev_info
;
2407 struct pagevec pvec
;
2410 pgoff_t end
; /* Inclusive */
2412 int range_whole
= 0;
2414 if (wbc
->nonblocking
&& bdi_write_congested(bdi
)) {
2415 wbc
->encountered_congestion
= 1;
2419 pagevec_init(&pvec
, 0);
2420 if (wbc
->range_cyclic
) {
2421 index
= mapping
->writeback_index
; /* Start from prev offset */
2424 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2425 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
2426 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2431 while (!done
&& (index
<= end
) &&
2432 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
2433 PAGECACHE_TAG_DIRTY
,
2434 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
2438 for (i
= 0; i
< nr_pages
; i
++) {
2439 struct page
*page
= pvec
.pages
[i
];
2442 * At this point we hold neither mapping->tree_lock nor
2443 * lock on the page itself: the page may be truncated or
2444 * invalidated (changing page->mapping to NULL), or even
2445 * swizzled back from swapper_space to tmpfs file
2448 if (tree
->ops
&& tree
->ops
->write_cache_pages_lock_hook
)
2449 tree
->ops
->write_cache_pages_lock_hook(page
);
2453 if (unlikely(page
->mapping
!= mapping
)) {
2458 if (!wbc
->range_cyclic
&& page
->index
> end
) {
2464 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
2465 if (PageWriteback(page
))
2467 wait_on_page_writeback(page
);
2470 if (PageWriteback(page
) ||
2471 !clear_page_dirty_for_io(page
)) {
2476 ret
= (*writepage
)(page
, wbc
, data
);
2478 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
2482 if (ret
|| wbc
->nr_to_write
<= 0)
2484 if (wbc
->nonblocking
&& bdi_write_congested(bdi
)) {
2485 wbc
->encountered_congestion
= 1;
2489 pagevec_release(&pvec
);
2492 if (!scanned
&& !done
) {
2494 * We hit the last page and there is more work to be done: wrap
2495 * back to the start of the file
2504 static noinline
void flush_write_bio(void *data
)
2506 struct extent_page_data
*epd
= data
;
2508 submit_one_bio(WRITE
, epd
->bio
, 0, 0);
2513 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2514 get_extent_t
*get_extent
,
2515 struct writeback_control
*wbc
)
2518 struct address_space
*mapping
= page
->mapping
;
2519 struct extent_page_data epd
= {
2522 .get_extent
= get_extent
,
2525 struct writeback_control wbc_writepages
= {
2527 .sync_mode
= WB_SYNC_NONE
,
2528 .older_than_this
= NULL
,
2530 .range_start
= page_offset(page
) + PAGE_CACHE_SIZE
,
2531 .range_end
= (loff_t
)-1,
2535 ret
= __extent_writepage(page
, wbc
, &epd
);
2537 extent_write_cache_pages(tree
, mapping
, &wbc_writepages
,
2538 __extent_writepage
, &epd
, flush_write_bio
);
2540 submit_one_bio(WRITE
, epd
.bio
, 0, 0);
2544 EXPORT_SYMBOL(extent_write_full_page
);
2546 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
2547 u64 start
, u64 end
, get_extent_t
*get_extent
,
2551 struct address_space
*mapping
= inode
->i_mapping
;
2553 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
2556 struct extent_page_data epd
= {
2559 .get_extent
= get_extent
,
2562 struct writeback_control wbc_writepages
= {
2563 .bdi
= inode
->i_mapping
->backing_dev_info
,
2565 .older_than_this
= NULL
,
2566 .nr_to_write
= nr_pages
* 2,
2567 .range_start
= start
,
2568 .range_end
= end
+ 1,
2571 while(start
<= end
) {
2572 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
2573 if (clear_page_dirty_for_io(page
))
2574 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
2576 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2577 tree
->ops
->writepage_end_io_hook(page
, start
,
2578 start
+ PAGE_CACHE_SIZE
- 1,
2582 page_cache_release(page
);
2583 start
+= PAGE_CACHE_SIZE
;
2587 submit_one_bio(WRITE
, epd
.bio
, 0, 0);
2590 EXPORT_SYMBOL(extent_write_locked_range
);
2593 int extent_writepages(struct extent_io_tree
*tree
,
2594 struct address_space
*mapping
,
2595 get_extent_t
*get_extent
,
2596 struct writeback_control
*wbc
)
2599 struct extent_page_data epd
= {
2602 .get_extent
= get_extent
,
2606 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
2607 __extent_writepage
, &epd
,
2610 submit_one_bio(WRITE
, epd
.bio
, 0, 0);
2614 EXPORT_SYMBOL(extent_writepages
);
2616 int extent_readpages(struct extent_io_tree
*tree
,
2617 struct address_space
*mapping
,
2618 struct list_head
*pages
, unsigned nr_pages
,
2619 get_extent_t get_extent
)
2621 struct bio
*bio
= NULL
;
2623 struct pagevec pvec
;
2624 unsigned long bio_flags
= 0;
2626 pagevec_init(&pvec
, 0);
2627 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
2628 struct page
*page
= list_entry(pages
->prev
, struct page
, lru
);
2630 prefetchw(&page
->flags
);
2631 list_del(&page
->lru
);
2633 * what we want to do here is call add_to_page_cache_lru,
2634 * but that isn't exported, so we reproduce it here
2636 if (!add_to_page_cache(page
, mapping
,
2637 page
->index
, GFP_KERNEL
)) {
2639 /* open coding of lru_cache_add, also not exported */
2640 page_cache_get(page
);
2641 if (!pagevec_add(&pvec
, page
))
2642 __pagevec_lru_add_file(&pvec
);
2643 __extent_read_full_page(tree
, page
, get_extent
,
2644 &bio
, 0, &bio_flags
);
2646 page_cache_release(page
);
2648 if (pagevec_count(&pvec
))
2649 __pagevec_lru_add_file(&pvec
);
2650 BUG_ON(!list_empty(pages
));
2652 submit_one_bio(READ
, bio
, 0, bio_flags
);
2655 EXPORT_SYMBOL(extent_readpages
);
2658 * basic invalidatepage code, this waits on any locked or writeback
2659 * ranges corresponding to the page, and then deletes any extent state
2660 * records from the tree
2662 int extent_invalidatepage(struct extent_io_tree
*tree
,
2663 struct page
*page
, unsigned long offset
)
2665 u64 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
);
2666 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2667 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
2669 start
+= (offset
+ blocksize
-1) & ~(blocksize
- 1);
2673 lock_extent(tree
, start
, end
, GFP_NOFS
);
2674 wait_on_extent_writeback(tree
, start
, end
);
2675 clear_extent_bit(tree
, start
, end
,
2676 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
,
2680 EXPORT_SYMBOL(extent_invalidatepage
);
2683 * simple commit_write call, set_range_dirty is used to mark both
2684 * the pages and the extent records as dirty
2686 int extent_commit_write(struct extent_io_tree
*tree
,
2687 struct inode
*inode
, struct page
*page
,
2688 unsigned from
, unsigned to
)
2690 loff_t pos
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
2692 set_page_extent_mapped(page
);
2693 set_page_dirty(page
);
2695 if (pos
> inode
->i_size
) {
2696 i_size_write(inode
, pos
);
2697 mark_inode_dirty(inode
);
2701 EXPORT_SYMBOL(extent_commit_write
);
2703 int extent_prepare_write(struct extent_io_tree
*tree
,
2704 struct inode
*inode
, struct page
*page
,
2705 unsigned from
, unsigned to
, get_extent_t
*get_extent
)
2707 u64 page_start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2708 u64 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
2710 u64 orig_block_start
;
2713 struct extent_map
*em
;
2714 unsigned blocksize
= 1 << inode
->i_blkbits
;
2715 size_t page_offset
= 0;
2716 size_t block_off_start
;
2717 size_t block_off_end
;
2723 set_page_extent_mapped(page
);
2725 block_start
= (page_start
+ from
) & ~((u64
)blocksize
- 1);
2726 block_end
= (page_start
+ to
- 1) | (blocksize
- 1);
2727 orig_block_start
= block_start
;
2729 lock_extent(tree
, page_start
, page_end
, GFP_NOFS
);
2730 while(block_start
<= block_end
) {
2731 em
= get_extent(inode
, page
, page_offset
, block_start
,
2732 block_end
- block_start
+ 1, 1);
2733 if (IS_ERR(em
) || !em
) {
2736 cur_end
= min(block_end
, extent_map_end(em
) - 1);
2737 block_off_start
= block_start
& (PAGE_CACHE_SIZE
- 1);
2738 block_off_end
= block_off_start
+ blocksize
;
2739 isnew
= clear_extent_new(tree
, block_start
, cur_end
, GFP_NOFS
);
2741 if (!PageUptodate(page
) && isnew
&&
2742 (block_off_end
> to
|| block_off_start
< from
)) {
2745 kaddr
= kmap_atomic(page
, KM_USER0
);
2746 if (block_off_end
> to
)
2747 memset(kaddr
+ to
, 0, block_off_end
- to
);
2748 if (block_off_start
< from
)
2749 memset(kaddr
+ block_off_start
, 0,
2750 from
- block_off_start
);
2751 flush_dcache_page(page
);
2752 kunmap_atomic(kaddr
, KM_USER0
);
2754 if ((em
->block_start
!= EXTENT_MAP_HOLE
&&
2755 em
->block_start
!= EXTENT_MAP_INLINE
) &&
2756 !isnew
&& !PageUptodate(page
) &&
2757 (block_off_end
> to
|| block_off_start
< from
) &&
2758 !test_range_bit(tree
, block_start
, cur_end
,
2759 EXTENT_UPTODATE
, 1)) {
2761 u64 extent_offset
= block_start
- em
->start
;
2763 sector
= (em
->block_start
+ extent_offset
) >> 9;
2764 iosize
= (cur_end
- block_start
+ blocksize
) &
2765 ~((u64
)blocksize
- 1);
2767 * we've already got the extent locked, but we
2768 * need to split the state such that our end_bio
2769 * handler can clear the lock.
2771 set_extent_bit(tree
, block_start
,
2772 block_start
+ iosize
- 1,
2773 EXTENT_LOCKED
, 0, NULL
, GFP_NOFS
);
2774 ret
= submit_extent_page(READ
, tree
, page
,
2775 sector
, iosize
, page_offset
, em
->bdev
,
2777 end_bio_extent_preparewrite
, 0,
2780 block_start
= block_start
+ iosize
;
2782 set_extent_uptodate(tree
, block_start
, cur_end
,
2784 unlock_extent(tree
, block_start
, cur_end
, GFP_NOFS
);
2785 block_start
= cur_end
+ 1;
2787 page_offset
= block_start
& (PAGE_CACHE_SIZE
- 1);
2788 free_extent_map(em
);
2791 wait_extent_bit(tree
, orig_block_start
,
2792 block_end
, EXTENT_LOCKED
);
2794 check_page_uptodate(tree
, page
);
2796 /* FIXME, zero out newly allocated blocks on error */
2799 EXPORT_SYMBOL(extent_prepare_write
);
2802 * a helper for releasepage, this tests for areas of the page that
2803 * are locked or under IO and drops the related state bits if it is safe
2806 int try_release_extent_state(struct extent_map_tree
*map
,
2807 struct extent_io_tree
*tree
, struct page
*page
,
2810 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2811 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2814 if (test_range_bit(tree
, start
, end
,
2815 EXTENT_IOBITS
| EXTENT_ORDERED
, 0))
2818 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
2820 clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
,
2825 EXPORT_SYMBOL(try_release_extent_state
);
2828 * a helper for releasepage. As long as there are no locked extents
2829 * in the range corresponding to the page, both state records and extent
2830 * map records are removed
2832 int try_release_extent_mapping(struct extent_map_tree
*map
,
2833 struct extent_io_tree
*tree
, struct page
*page
,
2836 struct extent_map
*em
;
2837 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2838 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2840 if ((mask
& __GFP_WAIT
) &&
2841 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
2843 while (start
<= end
) {
2844 len
= end
- start
+ 1;
2845 spin_lock(&map
->lock
);
2846 em
= lookup_extent_mapping(map
, start
, len
);
2847 if (!em
|| IS_ERR(em
)) {
2848 spin_unlock(&map
->lock
);
2851 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
2852 em
->start
!= start
) {
2853 spin_unlock(&map
->lock
);
2854 free_extent_map(em
);
2857 if (!test_range_bit(tree
, em
->start
,
2858 extent_map_end(em
) - 1,
2859 EXTENT_LOCKED
| EXTENT_WRITEBACK
|
2862 remove_extent_mapping(map
, em
);
2863 /* once for the rb tree */
2864 free_extent_map(em
);
2866 start
= extent_map_end(em
);
2867 spin_unlock(&map
->lock
);
2870 free_extent_map(em
);
2873 return try_release_extent_state(map
, tree
, page
, mask
);
2875 EXPORT_SYMBOL(try_release_extent_mapping
);
2877 sector_t
extent_bmap(struct address_space
*mapping
, sector_t iblock
,
2878 get_extent_t
*get_extent
)
2880 struct inode
*inode
= mapping
->host
;
2881 u64 start
= iblock
<< inode
->i_blkbits
;
2882 sector_t sector
= 0;
2883 size_t blksize
= (1 << inode
->i_blkbits
);
2884 struct extent_map
*em
;
2886 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, start
+ blksize
- 1,
2888 em
= get_extent(inode
, NULL
, 0, start
, blksize
, 0);
2889 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, start
+ blksize
- 1,
2891 if (!em
|| IS_ERR(em
))
2894 if (em
->block_start
> EXTENT_MAP_LAST_BYTE
)
2897 sector
= (em
->block_start
+ start
- em
->start
) >> inode
->i_blkbits
;
2899 free_extent_map(em
);
2903 static inline struct page
*extent_buffer_page(struct extent_buffer
*eb
,
2907 struct address_space
*mapping
;
2910 return eb
->first_page
;
2911 i
+= eb
->start
>> PAGE_CACHE_SHIFT
;
2912 mapping
= eb
->first_page
->mapping
;
2917 * extent_buffer_page is only called after pinning the page
2918 * by increasing the reference count. So we know the page must
2919 * be in the radix tree.
2922 p
= radix_tree_lookup(&mapping
->page_tree
, i
);
2928 static inline unsigned long num_extent_pages(u64 start
, u64 len
)
2930 return ((start
+ len
+ PAGE_CACHE_SIZE
- 1) >> PAGE_CACHE_SHIFT
) -
2931 (start
>> PAGE_CACHE_SHIFT
);
2934 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
2939 struct extent_buffer
*eb
= NULL
;
2941 unsigned long flags
;
2944 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
2947 mutex_init(&eb
->mutex
);
2949 spin_lock_irqsave(&leak_lock
, flags
);
2950 list_add(&eb
->leak_list
, &buffers
);
2951 spin_unlock_irqrestore(&leak_lock
, flags
);
2953 atomic_set(&eb
->refs
, 1);
2958 static void __free_extent_buffer(struct extent_buffer
*eb
)
2961 unsigned long flags
;
2962 spin_lock_irqsave(&leak_lock
, flags
);
2963 list_del(&eb
->leak_list
);
2964 spin_unlock_irqrestore(&leak_lock
, flags
);
2966 kmem_cache_free(extent_buffer_cache
, eb
);
2969 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
2970 u64 start
, unsigned long len
,
2974 unsigned long num_pages
= num_extent_pages(start
, len
);
2976 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
2977 struct extent_buffer
*eb
;
2978 struct extent_buffer
*exists
= NULL
;
2980 struct address_space
*mapping
= tree
->mapping
;
2983 spin_lock(&tree
->buffer_lock
);
2984 eb
= buffer_search(tree
, start
);
2986 atomic_inc(&eb
->refs
);
2987 spin_unlock(&tree
->buffer_lock
);
2988 mark_page_accessed(eb
->first_page
);
2991 spin_unlock(&tree
->buffer_lock
);
2993 eb
= __alloc_extent_buffer(tree
, start
, len
, mask
);
2998 eb
->first_page
= page0
;
3001 page_cache_get(page0
);
3002 mark_page_accessed(page0
);
3003 set_page_extent_mapped(page0
);
3004 set_page_extent_head(page0
, len
);
3005 uptodate
= PageUptodate(page0
);
3009 for (; i
< num_pages
; i
++, index
++) {
3010 p
= find_or_create_page(mapping
, index
, mask
| __GFP_HIGHMEM
);
3015 set_page_extent_mapped(p
);
3016 mark_page_accessed(p
);
3019 set_page_extent_head(p
, len
);
3021 set_page_private(p
, EXTENT_PAGE_PRIVATE
);
3023 if (!PageUptodate(p
))
3028 eb
->flags
|= EXTENT_UPTODATE
;
3029 eb
->flags
|= EXTENT_BUFFER_FILLED
;
3031 spin_lock(&tree
->buffer_lock
);
3032 exists
= buffer_tree_insert(tree
, start
, &eb
->rb_node
);
3034 /* add one reference for the caller */
3035 atomic_inc(&exists
->refs
);
3036 spin_unlock(&tree
->buffer_lock
);
3039 spin_unlock(&tree
->buffer_lock
);
3041 /* add one reference for the tree */
3042 atomic_inc(&eb
->refs
);
3046 if (!atomic_dec_and_test(&eb
->refs
))
3048 for (index
= 1; index
< i
; index
++)
3049 page_cache_release(extent_buffer_page(eb
, index
));
3050 page_cache_release(extent_buffer_page(eb
, 0));
3051 __free_extent_buffer(eb
);
3054 EXPORT_SYMBOL(alloc_extent_buffer
);
3056 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
3057 u64 start
, unsigned long len
,
3060 struct extent_buffer
*eb
;
3062 spin_lock(&tree
->buffer_lock
);
3063 eb
= buffer_search(tree
, start
);
3065 atomic_inc(&eb
->refs
);
3066 spin_unlock(&tree
->buffer_lock
);
3069 mark_page_accessed(eb
->first_page
);
3073 EXPORT_SYMBOL(find_extent_buffer
);
3075 void free_extent_buffer(struct extent_buffer
*eb
)
3080 if (!atomic_dec_and_test(&eb
->refs
))
3085 EXPORT_SYMBOL(free_extent_buffer
);
3087 int clear_extent_buffer_dirty(struct extent_io_tree
*tree
,
3088 struct extent_buffer
*eb
)
3092 unsigned long num_pages
;
3095 u64 start
= eb
->start
;
3096 u64 end
= start
+ eb
->len
- 1;
3098 set
= clear_extent_dirty(tree
, start
, end
, GFP_NOFS
);
3099 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3101 for (i
= 0; i
< num_pages
; i
++) {
3102 page
= extent_buffer_page(eb
, i
);
3103 if (!set
&& !PageDirty(page
))
3108 set_page_extent_head(page
, eb
->len
);
3110 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
3113 * if we're on the last page or the first page and the
3114 * block isn't aligned on a page boundary, do extra checks
3115 * to make sure we don't clean page that is partially dirty
3117 if ((i
== 0 && (eb
->start
& (PAGE_CACHE_SIZE
- 1))) ||
3118 ((i
== num_pages
- 1) &&
3119 ((eb
->start
+ eb
->len
) & (PAGE_CACHE_SIZE
- 1)))) {
3120 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
3121 end
= start
+ PAGE_CACHE_SIZE
- 1;
3122 if (test_range_bit(tree
, start
, end
,
3128 clear_page_dirty_for_io(page
);
3129 spin_lock_irq(&page
->mapping
->tree_lock
);
3130 if (!PageDirty(page
)) {
3131 radix_tree_tag_clear(&page
->mapping
->page_tree
,
3133 PAGECACHE_TAG_DIRTY
);
3135 spin_unlock_irq(&page
->mapping
->tree_lock
);
3140 EXPORT_SYMBOL(clear_extent_buffer_dirty
);
3142 int wait_on_extent_buffer_writeback(struct extent_io_tree
*tree
,
3143 struct extent_buffer
*eb
)
3145 return wait_on_extent_writeback(tree
, eb
->start
,
3146 eb
->start
+ eb
->len
- 1);
3148 EXPORT_SYMBOL(wait_on_extent_buffer_writeback
);
3150 int set_extent_buffer_dirty(struct extent_io_tree
*tree
,
3151 struct extent_buffer
*eb
)
3154 unsigned long num_pages
;
3156 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3157 for (i
= 0; i
< num_pages
; i
++) {
3158 struct page
*page
= extent_buffer_page(eb
, i
);
3159 /* writepage may need to do something special for the
3160 * first page, we have to make sure page->private is
3161 * properly set. releasepage may drop page->private
3162 * on us if the page isn't already dirty.
3166 set_page_extent_head(page
, eb
->len
);
3167 } else if (PagePrivate(page
) &&
3168 page
->private != EXTENT_PAGE_PRIVATE
) {
3169 set_page_extent_mapped(page
);
3171 __set_page_dirty_nobuffers(extent_buffer_page(eb
, i
));
3172 set_extent_dirty(tree
, page_offset(page
),
3173 page_offset(page
) + PAGE_CACHE_SIZE
-1,
3179 EXPORT_SYMBOL(set_extent_buffer_dirty
);
3181 int clear_extent_buffer_uptodate(struct extent_io_tree
*tree
,
3182 struct extent_buffer
*eb
)
3186 unsigned long num_pages
;
3188 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3189 eb
->flags
&= ~EXTENT_UPTODATE
;
3191 clear_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3193 for (i
= 0; i
< num_pages
; i
++) {
3194 page
= extent_buffer_page(eb
, i
);
3196 ClearPageUptodate(page
);
3201 int set_extent_buffer_uptodate(struct extent_io_tree
*tree
,
3202 struct extent_buffer
*eb
)
3206 unsigned long num_pages
;
3208 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3210 set_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3212 for (i
= 0; i
< num_pages
; i
++) {
3213 page
= extent_buffer_page(eb
, i
);
3214 if ((i
== 0 && (eb
->start
& (PAGE_CACHE_SIZE
- 1))) ||
3215 ((i
== num_pages
- 1) &&
3216 ((eb
->start
+ eb
->len
) & (PAGE_CACHE_SIZE
- 1)))) {
3217 check_page_uptodate(tree
, page
);
3220 SetPageUptodate(page
);
3224 EXPORT_SYMBOL(set_extent_buffer_uptodate
);
3226 int extent_range_uptodate(struct extent_io_tree
*tree
,
3231 int pg_uptodate
= 1;
3233 unsigned long index
;
3235 ret
= test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1);
3238 while(start
<= end
) {
3239 index
= start
>> PAGE_CACHE_SHIFT
;
3240 page
= find_get_page(tree
->mapping
, index
);
3241 uptodate
= PageUptodate(page
);
3242 page_cache_release(page
);
3247 start
+= PAGE_CACHE_SIZE
;
3252 int extent_buffer_uptodate(struct extent_io_tree
*tree
,
3253 struct extent_buffer
*eb
)
3256 unsigned long num_pages
;
3259 int pg_uptodate
= 1;
3261 if (eb
->flags
& EXTENT_UPTODATE
)
3264 ret
= test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3265 EXTENT_UPTODATE
, 1);
3269 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3270 for (i
= 0; i
< num_pages
; i
++) {
3271 page
= extent_buffer_page(eb
, i
);
3272 if (!PageUptodate(page
)) {
3279 EXPORT_SYMBOL(extent_buffer_uptodate
);
3281 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
3282 struct extent_buffer
*eb
,
3283 u64 start
, int wait
,
3284 get_extent_t
*get_extent
, int mirror_num
)
3287 unsigned long start_i
;
3291 int locked_pages
= 0;
3292 int all_uptodate
= 1;
3293 int inc_all_pages
= 0;
3294 unsigned long num_pages
;
3295 struct bio
*bio
= NULL
;
3296 unsigned long bio_flags
= 0;
3298 if (eb
->flags
& EXTENT_UPTODATE
)
3301 if (test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3302 EXTENT_UPTODATE
, 1)) {
3307 WARN_ON(start
< eb
->start
);
3308 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
3309 (eb
->start
>> PAGE_CACHE_SHIFT
);
3314 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3315 for (i
= start_i
; i
< num_pages
; i
++) {
3316 page
= extent_buffer_page(eb
, i
);
3318 if (!trylock_page(page
))
3324 if (!PageUptodate(page
)) {
3330 eb
->flags
|= EXTENT_UPTODATE
;
3332 printk("all up to date but ret is %d\n", ret
);
3337 for (i
= start_i
; i
< num_pages
; i
++) {
3338 page
= extent_buffer_page(eb
, i
);
3340 page_cache_get(page
);
3341 if (!PageUptodate(page
)) {
3344 ClearPageError(page
);
3345 err
= __extent_read_full_page(tree
, page
,
3347 mirror_num
, &bio_flags
);
3350 printk("err %d from __extent_read_full_page\n", ret
);
3358 submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3362 printk("ret %d wait %d returning\n", ret
, wait
);
3365 for (i
= start_i
; i
< num_pages
; i
++) {
3366 page
= extent_buffer_page(eb
, i
);
3367 wait_on_page_locked(page
);
3368 if (!PageUptodate(page
)) {
3369 printk("page not uptodate after wait_on_page_locked\n");
3374 eb
->flags
|= EXTENT_UPTODATE
;
3379 while(locked_pages
> 0) {
3380 page
= extent_buffer_page(eb
, i
);
3387 EXPORT_SYMBOL(read_extent_buffer_pages
);
3389 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
3390 unsigned long start
,
3397 char *dst
= (char *)dstv
;
3398 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3399 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3401 WARN_ON(start
> eb
->len
);
3402 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3404 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3407 page
= extent_buffer_page(eb
, i
);
3409 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
3410 kaddr
= kmap_atomic(page
, KM_USER1
);
3411 memcpy(dst
, kaddr
+ offset
, cur
);
3412 kunmap_atomic(kaddr
, KM_USER1
);
3420 EXPORT_SYMBOL(read_extent_buffer
);
3422 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
3423 unsigned long min_len
, char **token
, char **map
,
3424 unsigned long *map_start
,
3425 unsigned long *map_len
, int km
)
3427 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
3430 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3431 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3432 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
3439 offset
= start_offset
;
3443 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
3445 if (start
+ min_len
> eb
->len
) {
3446 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb
->start
, eb
->len
, start
, min_len
);
3450 p
= extent_buffer_page(eb
, i
);
3451 kaddr
= kmap_atomic(p
, km
);
3453 *map
= kaddr
+ offset
;
3454 *map_len
= PAGE_CACHE_SIZE
- offset
;
3457 EXPORT_SYMBOL(map_private_extent_buffer
);
3459 int map_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
3460 unsigned long min_len
,
3461 char **token
, char **map
,
3462 unsigned long *map_start
,
3463 unsigned long *map_len
, int km
)
3467 if (eb
->map_token
) {
3468 unmap_extent_buffer(eb
, eb
->map_token
, km
);
3469 eb
->map_token
= NULL
;
3471 WARN_ON(!mutex_is_locked(&eb
->mutex
));
3473 err
= map_private_extent_buffer(eb
, start
, min_len
, token
, map
,
3474 map_start
, map_len
, km
);
3476 eb
->map_token
= *token
;
3478 eb
->map_start
= *map_start
;
3479 eb
->map_len
= *map_len
;
3483 EXPORT_SYMBOL(map_extent_buffer
);
3485 void unmap_extent_buffer(struct extent_buffer
*eb
, char *token
, int km
)
3487 kunmap_atomic(token
, km
);
3489 EXPORT_SYMBOL(unmap_extent_buffer
);
3491 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
3492 unsigned long start
,
3499 char *ptr
= (char *)ptrv
;
3500 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3501 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3504 WARN_ON(start
> eb
->len
);
3505 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3507 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3510 page
= extent_buffer_page(eb
, i
);
3512 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
3514 kaddr
= kmap_atomic(page
, KM_USER0
);
3515 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
3516 kunmap_atomic(kaddr
, KM_USER0
);
3527 EXPORT_SYMBOL(memcmp_extent_buffer
);
3529 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
3530 unsigned long start
, unsigned long len
)
3536 char *src
= (char *)srcv
;
3537 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3538 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3540 WARN_ON(start
> eb
->len
);
3541 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3543 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3546 page
= extent_buffer_page(eb
, i
);
3547 WARN_ON(!PageUptodate(page
));
3549 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
3550 kaddr
= kmap_atomic(page
, KM_USER1
);
3551 memcpy(kaddr
+ offset
, src
, cur
);
3552 kunmap_atomic(kaddr
, KM_USER1
);
3560 EXPORT_SYMBOL(write_extent_buffer
);
3562 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
3563 unsigned long start
, unsigned long len
)
3569 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3570 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3572 WARN_ON(start
> eb
->len
);
3573 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3575 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3578 page
= extent_buffer_page(eb
, i
);
3579 WARN_ON(!PageUptodate(page
));
3581 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
3582 kaddr
= kmap_atomic(page
, KM_USER0
);
3583 memset(kaddr
+ offset
, c
, cur
);
3584 kunmap_atomic(kaddr
, KM_USER0
);
3591 EXPORT_SYMBOL(memset_extent_buffer
);
3593 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
3594 unsigned long dst_offset
, unsigned long src_offset
,
3597 u64 dst_len
= dst
->len
;
3602 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3603 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
3605 WARN_ON(src
->len
!= dst_len
);
3607 offset
= (start_offset
+ dst_offset
) &
3608 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3611 page
= extent_buffer_page(dst
, i
);
3612 WARN_ON(!PageUptodate(page
));
3614 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
3616 kaddr
= kmap_atomic(page
, KM_USER0
);
3617 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
3618 kunmap_atomic(kaddr
, KM_USER0
);
3626 EXPORT_SYMBOL(copy_extent_buffer
);
3628 static void move_pages(struct page
*dst_page
, struct page
*src_page
,
3629 unsigned long dst_off
, unsigned long src_off
,
3632 char *dst_kaddr
= kmap_atomic(dst_page
, KM_USER0
);
3633 if (dst_page
== src_page
) {
3634 memmove(dst_kaddr
+ dst_off
, dst_kaddr
+ src_off
, len
);
3636 char *src_kaddr
= kmap_atomic(src_page
, KM_USER1
);
3637 char *p
= dst_kaddr
+ dst_off
+ len
;
3638 char *s
= src_kaddr
+ src_off
+ len
;
3643 kunmap_atomic(src_kaddr
, KM_USER1
);
3645 kunmap_atomic(dst_kaddr
, KM_USER0
);
3648 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
3649 unsigned long dst_off
, unsigned long src_off
,
3652 char *dst_kaddr
= kmap_atomic(dst_page
, KM_USER0
);
3655 if (dst_page
!= src_page
)
3656 src_kaddr
= kmap_atomic(src_page
, KM_USER1
);
3658 src_kaddr
= dst_kaddr
;
3660 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
3661 kunmap_atomic(dst_kaddr
, KM_USER0
);
3662 if (dst_page
!= src_page
)
3663 kunmap_atomic(src_kaddr
, KM_USER1
);
3666 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
3667 unsigned long src_offset
, unsigned long len
)
3670 size_t dst_off_in_page
;
3671 size_t src_off_in_page
;
3672 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3673 unsigned long dst_i
;
3674 unsigned long src_i
;
3676 if (src_offset
+ len
> dst
->len
) {
3677 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
3678 src_offset
, len
, dst
->len
);
3681 if (dst_offset
+ len
> dst
->len
) {
3682 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
3683 dst_offset
, len
, dst
->len
);
3688 dst_off_in_page
= (start_offset
+ dst_offset
) &
3689 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3690 src_off_in_page
= (start_offset
+ src_offset
) &
3691 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3693 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
3694 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
3696 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
3698 cur
= min_t(unsigned long, cur
,
3699 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
3701 copy_pages(extent_buffer_page(dst
, dst_i
),
3702 extent_buffer_page(dst
, src_i
),
3703 dst_off_in_page
, src_off_in_page
, cur
);
3710 EXPORT_SYMBOL(memcpy_extent_buffer
);
3712 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
3713 unsigned long src_offset
, unsigned long len
)
3716 size_t dst_off_in_page
;
3717 size_t src_off_in_page
;
3718 unsigned long dst_end
= dst_offset
+ len
- 1;
3719 unsigned long src_end
= src_offset
+ len
- 1;
3720 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3721 unsigned long dst_i
;
3722 unsigned long src_i
;
3724 if (src_offset
+ len
> dst
->len
) {
3725 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
3726 src_offset
, len
, dst
->len
);
3729 if (dst_offset
+ len
> dst
->len
) {
3730 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
3731 dst_offset
, len
, dst
->len
);
3734 if (dst_offset
< src_offset
) {
3735 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
3739 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
3740 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
3742 dst_off_in_page
= (start_offset
+ dst_end
) &
3743 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3744 src_off_in_page
= (start_offset
+ src_end
) &
3745 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3747 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
3748 cur
= min(cur
, dst_off_in_page
+ 1);
3749 move_pages(extent_buffer_page(dst
, dst_i
),
3750 extent_buffer_page(dst
, src_i
),
3751 dst_off_in_page
- cur
+ 1,
3752 src_off_in_page
- cur
+ 1, cur
);
3759 EXPORT_SYMBOL(memmove_extent_buffer
);
3761 int try_release_extent_buffer(struct extent_io_tree
*tree
, struct page
*page
)
3763 u64 start
= page_offset(page
);
3764 struct extent_buffer
*eb
;
3767 unsigned long num_pages
;
3769 spin_lock(&tree
->buffer_lock
);
3770 eb
= buffer_search(tree
, start
);
3774 if (atomic_read(&eb
->refs
) > 1) {
3778 /* at this point we can safely release the extent buffer */
3779 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3780 for (i
= 0; i
< num_pages
; i
++)
3781 page_cache_release(extent_buffer_page(eb
, i
));
3782 rb_erase(&eb
->rb_node
, &tree
->buffer
);
3783 __free_extent_buffer(eb
);
3785 spin_unlock(&tree
->buffer_lock
);
3788 EXPORT_SYMBOL(try_release_extent_buffer
);