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/writeback.h>
13 #include <linux/pagevec.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
18 #include "btrfs_inode.h"
20 static struct kmem_cache
*extent_state_cache
;
21 static struct kmem_cache
*extent_buffer_cache
;
23 static LIST_HEAD(buffers
);
24 static LIST_HEAD(states
);
28 static DEFINE_SPINLOCK(leak_lock
);
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
;
44 /* tells writepage not to lock the state bits for this range
45 * it still does the unlocking
47 unsigned int extent_locked
:1;
49 /* tells the submit_bio code to use a WRITE_SYNC */
50 unsigned int sync_io
:1;
53 int __init
extent_io_init(void)
55 extent_state_cache
= kmem_cache_create("extent_state",
56 sizeof(struct extent_state
), 0,
57 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
58 if (!extent_state_cache
)
61 extent_buffer_cache
= kmem_cache_create("extent_buffers",
62 sizeof(struct extent_buffer
), 0,
63 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
64 if (!extent_buffer_cache
)
65 goto free_state_cache
;
69 kmem_cache_destroy(extent_state_cache
);
73 void extent_io_exit(void)
75 struct extent_state
*state
;
76 struct extent_buffer
*eb
;
78 while (!list_empty(&states
)) {
79 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
80 printk(KERN_ERR
"btrfs state leak: start %llu end %llu "
81 "state %lu in tree %p refs %d\n",
82 (unsigned long long)state
->start
,
83 (unsigned long long)state
->end
,
84 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(KERN_ERR
"btrfs buffer leak start %llu len %lu "
93 "refs %d\n", (unsigned long long)eb
->start
,
94 eb
->len
, atomic_read(&eb
->refs
));
95 list_del(&eb
->leak_list
);
96 kmem_cache_free(extent_buffer_cache
, eb
);
98 if (extent_state_cache
)
99 kmem_cache_destroy(extent_state_cache
);
100 if (extent_buffer_cache
)
101 kmem_cache_destroy(extent_buffer_cache
);
104 void extent_io_tree_init(struct extent_io_tree
*tree
,
105 struct address_space
*mapping
, gfp_t mask
)
107 tree
->state
.rb_node
= NULL
;
108 tree
->buffer
.rb_node
= NULL
;
110 tree
->dirty_bytes
= 0;
111 spin_lock_init(&tree
->lock
);
112 spin_lock_init(&tree
->buffer_lock
);
113 tree
->mapping
= mapping
;
116 static struct extent_state
*alloc_extent_state(gfp_t mask
)
118 struct extent_state
*state
;
123 state
= kmem_cache_alloc(extent_state_cache
, mask
);
130 spin_lock_irqsave(&leak_lock
, flags
);
131 list_add(&state
->leak_list
, &states
);
132 spin_unlock_irqrestore(&leak_lock
, flags
);
134 atomic_set(&state
->refs
, 1);
135 init_waitqueue_head(&state
->wq
);
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
);
157 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
158 struct rb_node
*node
)
160 struct rb_node
**p
= &root
->rb_node
;
161 struct rb_node
*parent
= NULL
;
162 struct tree_entry
*entry
;
166 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
168 if (offset
< entry
->start
)
170 else if (offset
> entry
->end
)
176 entry
= rb_entry(node
, struct tree_entry
, rb_node
);
177 rb_link_node(node
, parent
, p
);
178 rb_insert_color(node
, root
);
182 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
183 struct rb_node
**prev_ret
,
184 struct rb_node
**next_ret
)
186 struct rb_root
*root
= &tree
->state
;
187 struct rb_node
*n
= root
->rb_node
;
188 struct rb_node
*prev
= NULL
;
189 struct rb_node
*orig_prev
= NULL
;
190 struct tree_entry
*entry
;
191 struct tree_entry
*prev_entry
= NULL
;
194 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
198 if (offset
< entry
->start
)
200 else if (offset
> entry
->end
)
208 while (prev
&& offset
> prev_entry
->end
) {
209 prev
= rb_next(prev
);
210 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
217 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
218 while (prev
&& offset
< prev_entry
->start
) {
219 prev
= rb_prev(prev
);
220 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
227 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
230 struct rb_node
*prev
= NULL
;
233 ret
= __etree_search(tree
, offset
, &prev
, NULL
);
239 static struct extent_buffer
*buffer_tree_insert(struct extent_io_tree
*tree
,
240 u64 offset
, struct rb_node
*node
)
242 struct rb_root
*root
= &tree
->buffer
;
243 struct rb_node
**p
= &root
->rb_node
;
244 struct rb_node
*parent
= NULL
;
245 struct extent_buffer
*eb
;
249 eb
= rb_entry(parent
, struct extent_buffer
, rb_node
);
251 if (offset
< eb
->start
)
253 else if (offset
> eb
->start
)
259 rb_link_node(node
, parent
, p
);
260 rb_insert_color(node
, root
);
264 static struct extent_buffer
*buffer_search(struct extent_io_tree
*tree
,
267 struct rb_root
*root
= &tree
->buffer
;
268 struct rb_node
*n
= root
->rb_node
;
269 struct extent_buffer
*eb
;
272 eb
= rb_entry(n
, struct extent_buffer
, rb_node
);
273 if (offset
< eb
->start
)
275 else if (offset
> eb
->start
)
284 * utility function to look for merge candidates inside a given range.
285 * Any extents with matching state are merged together into a single
286 * extent in the tree. Extents with EXTENT_IO in their state field
287 * are not merged because the end_io handlers need to be able to do
288 * operations on them without sleeping (or doing allocations/splits).
290 * This should be called with the tree lock held.
292 static int merge_state(struct extent_io_tree
*tree
,
293 struct extent_state
*state
)
295 struct extent_state
*other
;
296 struct rb_node
*other_node
;
298 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
301 other_node
= rb_prev(&state
->rb_node
);
303 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
304 if (other
->end
== state
->start
- 1 &&
305 other
->state
== state
->state
) {
306 state
->start
= other
->start
;
308 rb_erase(&other
->rb_node
, &tree
->state
);
309 free_extent_state(other
);
312 other_node
= rb_next(&state
->rb_node
);
314 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
315 if (other
->start
== state
->end
+ 1 &&
316 other
->state
== state
->state
) {
317 other
->start
= state
->start
;
319 rb_erase(&state
->rb_node
, &tree
->state
);
320 free_extent_state(state
);
326 static void set_state_cb(struct extent_io_tree
*tree
,
327 struct extent_state
*state
,
330 if (tree
->ops
&& tree
->ops
->set_bit_hook
) {
331 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
->start
,
332 state
->end
, state
->state
, bits
);
336 static void clear_state_cb(struct extent_io_tree
*tree
,
337 struct extent_state
*state
,
340 if (tree
->ops
&& tree
->ops
->clear_bit_hook
) {
341 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
->start
,
342 state
->end
, state
->state
, bits
);
347 * insert an extent_state struct into the tree. 'bits' are set on the
348 * struct before it is inserted.
350 * This may return -EEXIST if the extent is already there, in which case the
351 * state struct is freed.
353 * The tree lock is not taken internally. This is a utility function and
354 * probably isn't what you want to call (see set/clear_extent_bit).
356 static int insert_state(struct extent_io_tree
*tree
,
357 struct extent_state
*state
, u64 start
, u64 end
,
360 struct rb_node
*node
;
363 printk(KERN_ERR
"btrfs end < start %llu %llu\n",
364 (unsigned long long)end
,
365 (unsigned long long)start
);
368 if (bits
& EXTENT_DIRTY
)
369 tree
->dirty_bytes
+= end
- start
+ 1;
370 state
->start
= start
;
372 set_state_cb(tree
, state
, bits
);
373 state
->state
|= bits
;
374 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
376 struct extent_state
*found
;
377 found
= rb_entry(node
, struct extent_state
, rb_node
);
378 printk(KERN_ERR
"btrfs found node %llu %llu on insert of "
379 "%llu %llu\n", (unsigned long long)found
->start
,
380 (unsigned long long)found
->end
,
381 (unsigned long long)start
, (unsigned long long)end
);
382 free_extent_state(state
);
386 merge_state(tree
, state
);
391 * split a given extent state struct in two, inserting the preallocated
392 * struct 'prealloc' as the newly created second half. 'split' indicates an
393 * offset inside 'orig' where it should be split.
396 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
397 * are two extent state structs in the tree:
398 * prealloc: [orig->start, split - 1]
399 * orig: [ split, orig->end ]
401 * The tree locks are not taken by this function. They need to be held
404 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
405 struct extent_state
*prealloc
, u64 split
)
407 struct rb_node
*node
;
408 prealloc
->start
= orig
->start
;
409 prealloc
->end
= split
- 1;
410 prealloc
->state
= orig
->state
;
413 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
415 free_extent_state(prealloc
);
418 prealloc
->tree
= tree
;
423 * utility function to clear some bits in an extent state struct.
424 * it will optionally wake up any one waiting on this state (wake == 1), or
425 * forcibly remove the state from the tree (delete == 1).
427 * If no bits are set on the state struct after clearing things, the
428 * struct is freed and removed from the tree
430 static int clear_state_bit(struct extent_io_tree
*tree
,
431 struct extent_state
*state
, int bits
, int wake
,
434 int ret
= state
->state
& bits
;
436 if ((bits
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
437 u64 range
= state
->end
- state
->start
+ 1;
438 WARN_ON(range
> tree
->dirty_bytes
);
439 tree
->dirty_bytes
-= range
;
441 clear_state_cb(tree
, state
, bits
);
442 state
->state
&= ~bits
;
445 if (delete || state
->state
== 0) {
447 clear_state_cb(tree
, state
, state
->state
);
448 rb_erase(&state
->rb_node
, &tree
->state
);
450 free_extent_state(state
);
455 merge_state(tree
, state
);
461 * clear some bits on a range in the tree. This may require splitting
462 * or inserting elements in the tree, so the gfp mask is used to
463 * indicate which allocations or sleeping are allowed.
465 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
466 * the given range from the tree regardless of state (ie for truncate).
468 * the range [start, end] is inclusive.
470 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
471 * bits were already set, or zero if none of the bits were already set.
473 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
474 int bits
, int wake
, int delete, gfp_t mask
)
476 struct extent_state
*state
;
477 struct extent_state
*prealloc
= NULL
;
478 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
);
502 last_end
= state
->end
;
505 * | ---- desired range ---- |
507 * | ------------- state -------------- |
509 * We need to split the extent we found, and may flip
510 * bits on second half.
512 * If the extent we found extends past our range, we
513 * just split and search again. It'll get split again
514 * the next time though.
516 * If the extent we found is inside our range, we clear
517 * the desired bit on it.
520 if (state
->start
< start
) {
522 prealloc
= alloc_extent_state(GFP_ATOMIC
);
523 err
= split_state(tree
, state
, prealloc
, start
);
524 BUG_ON(err
== -EEXIST
);
528 if (state
->end
<= end
) {
529 set
|= clear_state_bit(tree
, state
, bits
,
531 if (last_end
== (u64
)-1)
533 start
= last_end
+ 1;
535 start
= state
->start
;
540 * | ---- desired range ---- |
542 * We need to split the extent, and clear the bit
545 if (state
->start
<= end
&& state
->end
> end
) {
547 prealloc
= alloc_extent_state(GFP_ATOMIC
);
548 err
= split_state(tree
, state
, prealloc
, end
+ 1);
549 BUG_ON(err
== -EEXIST
);
553 set
|= clear_state_bit(tree
, prealloc
, bits
,
559 set
|= clear_state_bit(tree
, state
, bits
, wake
, delete);
560 if (last_end
== (u64
)-1)
562 start
= last_end
+ 1;
566 spin_unlock(&tree
->lock
);
568 free_extent_state(prealloc
);
575 spin_unlock(&tree
->lock
);
576 if (mask
& __GFP_WAIT
)
581 static int wait_on_state(struct extent_io_tree
*tree
,
582 struct extent_state
*state
)
583 __releases(tree
->lock
)
584 __acquires(tree
->lock
)
587 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
588 spin_unlock(&tree
->lock
);
590 spin_lock(&tree
->lock
);
591 finish_wait(&state
->wq
, &wait
);
596 * waits for one or more bits to clear on a range in the state tree.
597 * The range [start, end] is inclusive.
598 * The tree lock is taken by this function
600 int wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
, int bits
)
602 struct extent_state
*state
;
603 struct rb_node
*node
;
605 spin_lock(&tree
->lock
);
609 * this search will find all the extents that end after
612 node
= tree_search(tree
, start
);
616 state
= rb_entry(node
, struct extent_state
, rb_node
);
618 if (state
->start
> end
)
621 if (state
->state
& bits
) {
622 start
= state
->start
;
623 atomic_inc(&state
->refs
);
624 wait_on_state(tree
, state
);
625 free_extent_state(state
);
628 start
= state
->end
+ 1;
633 if (need_resched()) {
634 spin_unlock(&tree
->lock
);
636 spin_lock(&tree
->lock
);
640 spin_unlock(&tree
->lock
);
644 static void set_state_bits(struct extent_io_tree
*tree
,
645 struct extent_state
*state
,
648 if ((bits
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
649 u64 range
= state
->end
- state
->start
+ 1;
650 tree
->dirty_bytes
+= range
;
652 set_state_cb(tree
, state
, bits
);
653 state
->state
|= bits
;
657 * set some bits on a range in the tree. This may require allocations or
658 * sleeping, so the gfp mask is used to indicate what is allowed.
660 * If any of the exclusive bits are set, this will fail with -EEXIST if some
661 * part of the range already has the desired bits set. The start of the
662 * existing range is returned in failed_start in this case.
664 * [start, end] is inclusive This takes the tree lock.
667 static int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
668 int bits
, int exclusive_bits
, u64
*failed_start
,
671 struct extent_state
*state
;
672 struct extent_state
*prealloc
= NULL
;
673 struct rb_node
*node
;
678 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
679 prealloc
= alloc_extent_state(mask
);
684 spin_lock(&tree
->lock
);
686 * this search will find all the extents that end after
689 node
= tree_search(tree
, start
);
691 err
= insert_state(tree
, prealloc
, start
, end
, bits
);
693 BUG_ON(err
== -EEXIST
);
696 state
= rb_entry(node
, struct extent_state
, rb_node
);
698 last_start
= state
->start
;
699 last_end
= state
->end
;
702 * | ---- desired range ---- |
705 * Just lock what we found and keep going
707 if (state
->start
== start
&& state
->end
<= end
) {
708 struct rb_node
*next_node
;
709 if (state
->state
& exclusive_bits
) {
710 *failed_start
= state
->start
;
714 set_state_bits(tree
, state
, bits
);
715 merge_state(tree
, state
);
716 if (last_end
== (u64
)-1)
719 start
= last_end
+ 1;
720 if (start
< end
&& prealloc
&& !need_resched()) {
721 next_node
= rb_next(node
);
723 state
= rb_entry(next_node
, struct extent_state
,
725 if (state
->start
== start
)
733 * | ---- desired range ---- |
736 * | ------------- state -------------- |
738 * We need to split the extent we found, and may flip bits on
741 * If the extent we found extends past our
742 * range, we just split and search again. It'll get split
743 * again the next time though.
745 * If the extent we found is inside our range, we set the
748 if (state
->start
< start
) {
749 if (state
->state
& exclusive_bits
) {
750 *failed_start
= start
;
754 err
= split_state(tree
, state
, prealloc
, start
);
755 BUG_ON(err
== -EEXIST
);
759 if (state
->end
<= end
) {
760 set_state_bits(tree
, state
, bits
);
761 merge_state(tree
, state
);
762 if (last_end
== (u64
)-1)
764 start
= last_end
+ 1;
766 start
= state
->start
;
771 * | ---- desired range ---- |
772 * | state | or | state |
774 * There's a hole, we need to insert something in it and
775 * ignore the extent we found.
777 if (state
->start
> start
) {
779 if (end
< last_start
)
782 this_end
= last_start
- 1;
783 err
= insert_state(tree
, prealloc
, start
, this_end
,
786 BUG_ON(err
== -EEXIST
);
789 start
= this_end
+ 1;
793 * | ---- desired range ---- |
795 * We need to split the extent, and set the bit
798 if (state
->start
<= end
&& state
->end
> end
) {
799 if (state
->state
& exclusive_bits
) {
800 *failed_start
= start
;
804 err
= split_state(tree
, state
, prealloc
, end
+ 1);
805 BUG_ON(err
== -EEXIST
);
807 set_state_bits(tree
, prealloc
, bits
);
808 merge_state(tree
, prealloc
);
816 spin_unlock(&tree
->lock
);
818 free_extent_state(prealloc
);
825 spin_unlock(&tree
->lock
);
826 if (mask
& __GFP_WAIT
)
831 /* wrappers around set/clear extent bit */
832 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
835 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, 0, NULL
,
839 int set_extent_ordered(struct extent_io_tree
*tree
, u64 start
, u64 end
,
842 return set_extent_bit(tree
, start
, end
, EXTENT_ORDERED
, 0, NULL
, mask
);
845 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
846 int bits
, gfp_t mask
)
848 return set_extent_bit(tree
, start
, end
, bits
, 0, NULL
,
852 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
853 int bits
, gfp_t mask
)
855 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, mask
);
858 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
861 return set_extent_bit(tree
, start
, end
,
862 EXTENT_DELALLOC
| EXTENT_DIRTY
| EXTENT_UPTODATE
,
866 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
869 return clear_extent_bit(tree
, start
, end
,
870 EXTENT_DIRTY
| EXTENT_DELALLOC
, 0, 0, mask
);
873 int clear_extent_ordered(struct extent_io_tree
*tree
, u64 start
, u64 end
,
876 return clear_extent_bit(tree
, start
, end
, EXTENT_ORDERED
, 1, 0, mask
);
879 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
882 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, NULL
,
886 static int clear_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
889 return clear_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, 0, mask
);
892 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
895 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, NULL
,
899 static int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
,
902 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0, mask
);
905 int wait_on_extent_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
907 return wait_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
);
911 * either insert or lock state struct between start and end use mask to tell
912 * us if waiting is desired.
914 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
915 int bits
, gfp_t mask
)
920 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
921 EXTENT_LOCKED
, &failed_start
, mask
);
922 if (err
== -EEXIST
&& (mask
& __GFP_WAIT
)) {
923 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
924 start
= failed_start
;
928 WARN_ON(start
> end
);
933 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
, gfp_t mask
)
935 return lock_extent_bits(tree
, start
, end
, 0, mask
);
938 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
,
944 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1,
945 &failed_start
, mask
);
946 if (err
== -EEXIST
) {
947 if (failed_start
> start
)
948 clear_extent_bit(tree
, start
, failed_start
- 1,
949 EXTENT_LOCKED
, 1, 0, mask
);
955 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
,
958 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, mask
);
962 * helper function to set pages and extents in the tree dirty
964 int set_range_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
)
966 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
967 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
970 while (index
<= end_index
) {
971 page
= find_get_page(tree
->mapping
, index
);
973 __set_page_dirty_nobuffers(page
);
974 page_cache_release(page
);
981 * helper function to set both pages and extents in the tree writeback
983 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
985 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
986 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
989 while (index
<= end_index
) {
990 page
= find_get_page(tree
->mapping
, index
);
992 set_page_writeback(page
);
993 page_cache_release(page
);
1000 * find the first offset in the io tree with 'bits' set. zero is
1001 * returned if we find something, and *start_ret and *end_ret are
1002 * set to reflect the state struct that was found.
1004 * If nothing was found, 1 is returned, < 0 on error
1006 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1007 u64
*start_ret
, u64
*end_ret
, int bits
)
1009 struct rb_node
*node
;
1010 struct extent_state
*state
;
1013 spin_lock(&tree
->lock
);
1015 * this search will find all the extents that end after
1018 node
= tree_search(tree
, start
);
1023 state
= rb_entry(node
, struct extent_state
, rb_node
);
1024 if (state
->end
>= start
&& (state
->state
& bits
)) {
1025 *start_ret
= state
->start
;
1026 *end_ret
= state
->end
;
1030 node
= rb_next(node
);
1035 spin_unlock(&tree
->lock
);
1039 /* find the first state struct with 'bits' set after 'start', and
1040 * return it. tree->lock must be held. NULL will returned if
1041 * nothing was found after 'start'
1043 struct extent_state
*find_first_extent_bit_state(struct extent_io_tree
*tree
,
1044 u64 start
, int bits
)
1046 struct rb_node
*node
;
1047 struct extent_state
*state
;
1050 * this search will find all the extents that end after
1053 node
= tree_search(tree
, start
);
1058 state
= rb_entry(node
, struct extent_state
, rb_node
);
1059 if (state
->end
>= start
&& (state
->state
& bits
))
1062 node
= rb_next(node
);
1071 * find a contiguous range of bytes in the file marked as delalloc, not
1072 * more than 'max_bytes'. start and end are used to return the range,
1074 * 1 is returned if we find something, 0 if nothing was in the tree
1076 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1077 u64
*start
, u64
*end
, u64 max_bytes
)
1079 struct rb_node
*node
;
1080 struct extent_state
*state
;
1081 u64 cur_start
= *start
;
1083 u64 total_bytes
= 0;
1085 spin_lock(&tree
->lock
);
1088 * this search will find all the extents that end after
1091 node
= tree_search(tree
, cur_start
);
1099 state
= rb_entry(node
, struct extent_state
, rb_node
);
1100 if (found
&& (state
->start
!= cur_start
||
1101 (state
->state
& EXTENT_BOUNDARY
))) {
1104 if (!(state
->state
& EXTENT_DELALLOC
)) {
1110 *start
= state
->start
;
1113 cur_start
= state
->end
+ 1;
1114 node
= rb_next(node
);
1117 total_bytes
+= state
->end
- state
->start
+ 1;
1118 if (total_bytes
>= max_bytes
)
1122 spin_unlock(&tree
->lock
);
1126 static noinline
int __unlock_for_delalloc(struct inode
*inode
,
1127 struct page
*locked_page
,
1131 struct page
*pages
[16];
1132 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1133 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1134 unsigned long nr_pages
= end_index
- index
+ 1;
1137 if (index
== locked_page
->index
&& end_index
== index
)
1140 while (nr_pages
> 0) {
1141 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1142 min_t(unsigned long, nr_pages
,
1143 ARRAY_SIZE(pages
)), pages
);
1144 for (i
= 0; i
< ret
; i
++) {
1145 if (pages
[i
] != locked_page
)
1146 unlock_page(pages
[i
]);
1147 page_cache_release(pages
[i
]);
1156 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1157 struct page
*locked_page
,
1161 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1162 unsigned long start_index
= index
;
1163 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1164 unsigned long pages_locked
= 0;
1165 struct page
*pages
[16];
1166 unsigned long nrpages
;
1170 /* the caller is responsible for locking the start index */
1171 if (index
== locked_page
->index
&& index
== end_index
)
1174 /* skip the page at the start index */
1175 nrpages
= end_index
- index
+ 1;
1176 while (nrpages
> 0) {
1177 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1178 min_t(unsigned long,
1179 nrpages
, ARRAY_SIZE(pages
)), pages
);
1184 /* now we have an array of pages, lock them all */
1185 for (i
= 0; i
< ret
; i
++) {
1187 * the caller is taking responsibility for
1190 if (pages
[i
] != locked_page
) {
1191 lock_page(pages
[i
]);
1192 if (!PageDirty(pages
[i
]) ||
1193 pages
[i
]->mapping
!= inode
->i_mapping
) {
1195 unlock_page(pages
[i
]);
1196 page_cache_release(pages
[i
]);
1200 page_cache_release(pages
[i
]);
1209 if (ret
&& pages_locked
) {
1210 __unlock_for_delalloc(inode
, locked_page
,
1212 ((u64
)(start_index
+ pages_locked
- 1)) <<
1219 * find a contiguous range of bytes in the file marked as delalloc, not
1220 * more than 'max_bytes'. start and end are used to return the range,
1222 * 1 is returned if we find something, 0 if nothing was in the tree
1224 static noinline u64
find_lock_delalloc_range(struct inode
*inode
,
1225 struct extent_io_tree
*tree
,
1226 struct page
*locked_page
,
1227 u64
*start
, u64
*end
,
1237 /* step one, find a bunch of delalloc bytes starting at start */
1238 delalloc_start
= *start
;
1240 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1242 if (!found
|| delalloc_end
<= *start
) {
1243 *start
= delalloc_start
;
1244 *end
= delalloc_end
;
1249 * start comes from the offset of locked_page. We have to lock
1250 * pages in order, so we can't process delalloc bytes before
1253 if (delalloc_start
< *start
)
1254 delalloc_start
= *start
;
1257 * make sure to limit the number of pages we try to lock down
1260 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
&& loops
)
1261 delalloc_end
= delalloc_start
+ PAGE_CACHE_SIZE
- 1;
1263 /* step two, lock all the pages after the page that has start */
1264 ret
= lock_delalloc_pages(inode
, locked_page
,
1265 delalloc_start
, delalloc_end
);
1266 if (ret
== -EAGAIN
) {
1267 /* some of the pages are gone, lets avoid looping by
1268 * shortening the size of the delalloc range we're searching
1271 unsigned long offset
= (*start
) & (PAGE_CACHE_SIZE
- 1);
1272 max_bytes
= PAGE_CACHE_SIZE
- offset
;
1282 /* step three, lock the state bits for the whole range */
1283 lock_extent(tree
, delalloc_start
, delalloc_end
, GFP_NOFS
);
1285 /* then test to make sure it is all still delalloc */
1286 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1287 EXTENT_DELALLOC
, 1);
1289 unlock_extent(tree
, delalloc_start
, delalloc_end
, GFP_NOFS
);
1290 __unlock_for_delalloc(inode
, locked_page
,
1291 delalloc_start
, delalloc_end
);
1295 *start
= delalloc_start
;
1296 *end
= delalloc_end
;
1301 int extent_clear_unlock_delalloc(struct inode
*inode
,
1302 struct extent_io_tree
*tree
,
1303 u64 start
, u64 end
, struct page
*locked_page
,
1306 int clear_delalloc
, int clear_dirty
,
1311 struct page
*pages
[16];
1312 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1313 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1314 unsigned long nr_pages
= end_index
- index
+ 1;
1319 clear_bits
|= EXTENT_LOCKED
;
1321 clear_bits
|= EXTENT_DIRTY
;
1324 clear_bits
|= EXTENT_DELALLOC
;
1326 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, GFP_NOFS
);
1327 if (!(unlock_pages
|| clear_dirty
|| set_writeback
|| end_writeback
))
1330 while (nr_pages
> 0) {
1331 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1332 min_t(unsigned long,
1333 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1334 for (i
= 0; i
< ret
; i
++) {
1335 if (pages
[i
] == locked_page
) {
1336 page_cache_release(pages
[i
]);
1340 clear_page_dirty_for_io(pages
[i
]);
1342 set_page_writeback(pages
[i
]);
1344 end_page_writeback(pages
[i
]);
1346 unlock_page(pages
[i
]);
1347 page_cache_release(pages
[i
]);
1357 * count the number of bytes in the tree that have a given bit(s)
1358 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1359 * cached. The total number found is returned.
1361 u64
count_range_bits(struct extent_io_tree
*tree
,
1362 u64
*start
, u64 search_end
, u64 max_bytes
,
1365 struct rb_node
*node
;
1366 struct extent_state
*state
;
1367 u64 cur_start
= *start
;
1368 u64 total_bytes
= 0;
1371 if (search_end
<= cur_start
) {
1376 spin_lock(&tree
->lock
);
1377 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1378 total_bytes
= tree
->dirty_bytes
;
1382 * this search will find all the extents that end after
1385 node
= tree_search(tree
, cur_start
);
1390 state
= rb_entry(node
, struct extent_state
, rb_node
);
1391 if (state
->start
> search_end
)
1393 if (state
->end
>= cur_start
&& (state
->state
& bits
)) {
1394 total_bytes
+= min(search_end
, state
->end
) + 1 -
1395 max(cur_start
, state
->start
);
1396 if (total_bytes
>= max_bytes
)
1399 *start
= state
->start
;
1403 node
= rb_next(node
);
1408 spin_unlock(&tree
->lock
);
1413 * set the private field for a given byte offset in the tree. If there isn't
1414 * an extent_state there already, this does nothing.
1416 int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1418 struct rb_node
*node
;
1419 struct extent_state
*state
;
1422 spin_lock(&tree
->lock
);
1424 * this search will find all the extents that end after
1427 node
= tree_search(tree
, start
);
1432 state
= rb_entry(node
, struct extent_state
, rb_node
);
1433 if (state
->start
!= start
) {
1437 state
->private = private;
1439 spin_unlock(&tree
->lock
);
1443 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1445 struct rb_node
*node
;
1446 struct extent_state
*state
;
1449 spin_lock(&tree
->lock
);
1451 * this search will find all the extents that end after
1454 node
= tree_search(tree
, start
);
1459 state
= rb_entry(node
, struct extent_state
, rb_node
);
1460 if (state
->start
!= start
) {
1464 *private = state
->private;
1466 spin_unlock(&tree
->lock
);
1471 * searches a range in the state tree for a given mask.
1472 * If 'filled' == 1, this returns 1 only if every extent in the tree
1473 * has the bits set. Otherwise, 1 is returned if any bit in the
1474 * range is found set.
1476 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1477 int bits
, int filled
)
1479 struct extent_state
*state
= NULL
;
1480 struct rb_node
*node
;
1483 spin_lock(&tree
->lock
);
1484 node
= tree_search(tree
, start
);
1485 while (node
&& start
<= end
) {
1486 state
= rb_entry(node
, struct extent_state
, rb_node
);
1488 if (filled
&& state
->start
> start
) {
1493 if (state
->start
> end
)
1496 if (state
->state
& bits
) {
1500 } else if (filled
) {
1504 start
= state
->end
+ 1;
1507 node
= rb_next(node
);
1514 spin_unlock(&tree
->lock
);
1519 * helper function to set a given page up to date if all the
1520 * extents in the tree for that page are up to date
1522 static int check_page_uptodate(struct extent_io_tree
*tree
,
1525 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1526 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1527 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1))
1528 SetPageUptodate(page
);
1533 * helper function to unlock a page if all the extents in the tree
1534 * for that page are unlocked
1536 static int check_page_locked(struct extent_io_tree
*tree
,
1539 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1540 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1541 if (!test_range_bit(tree
, start
, end
, EXTENT_LOCKED
, 0))
1547 * helper function to end page writeback if all the extents
1548 * in the tree for that page are done with writeback
1550 static int check_page_writeback(struct extent_io_tree
*tree
,
1553 end_page_writeback(page
);
1557 /* lots and lots of room for performance fixes in the end_bio funcs */
1560 * after a writepage IO is done, we need to:
1561 * clear the uptodate bits on error
1562 * clear the writeback bits in the extent tree for this IO
1563 * end_page_writeback if the page has no more pending IO
1565 * Scheduling is not allowed, so the extent state tree is expected
1566 * to have one and only one object corresponding to this IO.
1568 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
1570 int uptodate
= err
== 0;
1571 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1572 struct extent_io_tree
*tree
;
1579 struct page
*page
= bvec
->bv_page
;
1580 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1582 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1584 end
= start
+ bvec
->bv_len
- 1;
1586 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1591 if (--bvec
>= bio
->bi_io_vec
)
1592 prefetchw(&bvec
->bv_page
->flags
);
1593 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
1594 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
1595 end
, NULL
, uptodate
);
1600 if (!uptodate
&& tree
->ops
&&
1601 tree
->ops
->writepage_io_failed_hook
) {
1602 ret
= tree
->ops
->writepage_io_failed_hook(bio
, page
,
1605 uptodate
= (err
== 0);
1611 clear_extent_uptodate(tree
, start
, end
, GFP_NOFS
);
1612 ClearPageUptodate(page
);
1617 end_page_writeback(page
);
1619 check_page_writeback(tree
, page
);
1620 } while (bvec
>= bio
->bi_io_vec
);
1626 * after a readpage IO is done, we need to:
1627 * clear the uptodate bits on error
1628 * set the uptodate bits if things worked
1629 * set the page up to date if all extents in the tree are uptodate
1630 * clear the lock bit in the extent tree
1631 * unlock the page if there are no other extents locked for it
1633 * Scheduling is not allowed, so the extent state tree is expected
1634 * to have one and only one object corresponding to this IO.
1636 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
1638 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1639 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1640 struct extent_io_tree
*tree
;
1650 struct page
*page
= bvec
->bv_page
;
1651 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1653 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1655 end
= start
+ bvec
->bv_len
- 1;
1657 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1662 if (--bvec
>= bio
->bi_io_vec
)
1663 prefetchw(&bvec
->bv_page
->flags
);
1665 if (uptodate
&& tree
->ops
&& tree
->ops
->readpage_end_io_hook
) {
1666 ret
= tree
->ops
->readpage_end_io_hook(page
, start
, end
,
1671 if (!uptodate
&& tree
->ops
&&
1672 tree
->ops
->readpage_io_failed_hook
) {
1673 ret
= tree
->ops
->readpage_io_failed_hook(bio
, page
,
1677 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1685 set_extent_uptodate(tree
, start
, end
,
1688 unlock_extent(tree
, start
, end
, GFP_ATOMIC
);
1692 SetPageUptodate(page
);
1694 ClearPageUptodate(page
);
1700 check_page_uptodate(tree
, page
);
1702 ClearPageUptodate(page
);
1705 check_page_locked(tree
, page
);
1707 } while (bvec
>= bio
->bi_io_vec
);
1713 * IO done from prepare_write is pretty simple, we just unlock
1714 * the structs in the extent tree when done, and set the uptodate bits
1717 static void end_bio_extent_preparewrite(struct bio
*bio
, int err
)
1719 const int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1720 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1721 struct extent_io_tree
*tree
;
1726 struct page
*page
= bvec
->bv_page
;
1727 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1729 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1731 end
= start
+ bvec
->bv_len
- 1;
1733 if (--bvec
>= bio
->bi_io_vec
)
1734 prefetchw(&bvec
->bv_page
->flags
);
1737 set_extent_uptodate(tree
, start
, end
, GFP_ATOMIC
);
1739 ClearPageUptodate(page
);
1743 unlock_extent(tree
, start
, end
, GFP_ATOMIC
);
1745 } while (bvec
>= bio
->bi_io_vec
);
1751 extent_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
1756 bio
= bio_alloc(gfp_flags
, nr_vecs
);
1758 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
1759 while (!bio
&& (nr_vecs
/= 2))
1760 bio
= bio_alloc(gfp_flags
, nr_vecs
);
1765 bio
->bi_bdev
= bdev
;
1766 bio
->bi_sector
= first_sector
;
1771 static int submit_one_bio(int rw
, struct bio
*bio
, int mirror_num
,
1772 unsigned long bio_flags
)
1775 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1776 struct page
*page
= bvec
->bv_page
;
1777 struct extent_io_tree
*tree
= bio
->bi_private
;
1781 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) + bvec
->bv_offset
;
1782 end
= start
+ bvec
->bv_len
- 1;
1784 bio
->bi_private
= NULL
;
1788 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
1789 tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
1790 mirror_num
, bio_flags
);
1792 submit_bio(rw
, bio
);
1793 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
1799 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
1800 struct page
*page
, sector_t sector
,
1801 size_t size
, unsigned long offset
,
1802 struct block_device
*bdev
,
1803 struct bio
**bio_ret
,
1804 unsigned long max_pages
,
1805 bio_end_io_t end_io_func
,
1807 unsigned long prev_bio_flags
,
1808 unsigned long bio_flags
)
1814 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
1815 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
1816 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
1818 if (bio_ret
&& *bio_ret
) {
1821 contig
= bio
->bi_sector
== sector
;
1823 contig
= bio
->bi_sector
+ (bio
->bi_size
>> 9) ==
1826 if (prev_bio_flags
!= bio_flags
|| !contig
||
1827 (tree
->ops
&& tree
->ops
->merge_bio_hook
&&
1828 tree
->ops
->merge_bio_hook(page
, offset
, page_size
, bio
,
1830 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
1831 ret
= submit_one_bio(rw
, bio
, mirror_num
,
1838 if (this_compressed
)
1841 nr
= bio_get_nr_vecs(bdev
);
1843 bio
= extent_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
1845 bio_add_page(bio
, page
, page_size
, offset
);
1846 bio
->bi_end_io
= end_io_func
;
1847 bio
->bi_private
= tree
;
1852 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
1857 void set_page_extent_mapped(struct page
*page
)
1859 if (!PagePrivate(page
)) {
1860 SetPagePrivate(page
);
1861 page_cache_get(page
);
1862 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
1866 static void set_page_extent_head(struct page
*page
, unsigned long len
)
1868 set_page_private(page
, EXTENT_PAGE_PRIVATE_FIRST_PAGE
| len
<< 2);
1872 * basic readpage implementation. Locked extent state structs are inserted
1873 * into the tree that are removed when the IO is done (by the end_io
1876 static int __extent_read_full_page(struct extent_io_tree
*tree
,
1878 get_extent_t
*get_extent
,
1879 struct bio
**bio
, int mirror_num
,
1880 unsigned long *bio_flags
)
1882 struct inode
*inode
= page
->mapping
->host
;
1883 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1884 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
1888 u64 last_byte
= i_size_read(inode
);
1892 struct extent_map
*em
;
1893 struct block_device
*bdev
;
1896 size_t page_offset
= 0;
1898 size_t disk_io_size
;
1899 size_t blocksize
= inode
->i_sb
->s_blocksize
;
1900 unsigned long this_bio_flag
= 0;
1902 set_page_extent_mapped(page
);
1905 lock_extent(tree
, start
, end
, GFP_NOFS
);
1907 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
1909 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
1912 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
1913 userpage
= kmap_atomic(page
, KM_USER0
);
1914 memset(userpage
+ zero_offset
, 0, iosize
);
1915 flush_dcache_page(page
);
1916 kunmap_atomic(userpage
, KM_USER0
);
1919 while (cur
<= end
) {
1920 if (cur
>= last_byte
) {
1922 iosize
= PAGE_CACHE_SIZE
- page_offset
;
1923 userpage
= kmap_atomic(page
, KM_USER0
);
1924 memset(userpage
+ page_offset
, 0, iosize
);
1925 flush_dcache_page(page
);
1926 kunmap_atomic(userpage
, KM_USER0
);
1927 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
1929 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1932 em
= get_extent(inode
, page
, page_offset
, cur
,
1934 if (IS_ERR(em
) || !em
) {
1936 unlock_extent(tree
, cur
, end
, GFP_NOFS
);
1939 extent_offset
= cur
- em
->start
;
1940 BUG_ON(extent_map_end(em
) <= cur
);
1943 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
1944 this_bio_flag
= EXTENT_BIO_COMPRESSED
;
1946 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
1947 cur_end
= min(extent_map_end(em
) - 1, end
);
1948 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
1949 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
1950 disk_io_size
= em
->block_len
;
1951 sector
= em
->block_start
>> 9;
1953 sector
= (em
->block_start
+ extent_offset
) >> 9;
1954 disk_io_size
= iosize
;
1957 block_start
= em
->block_start
;
1958 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
1959 block_start
= EXTENT_MAP_HOLE
;
1960 free_extent_map(em
);
1963 /* we've found a hole, just zero and go on */
1964 if (block_start
== EXTENT_MAP_HOLE
) {
1966 userpage
= kmap_atomic(page
, KM_USER0
);
1967 memset(userpage
+ page_offset
, 0, iosize
);
1968 flush_dcache_page(page
);
1969 kunmap_atomic(userpage
, KM_USER0
);
1971 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
1973 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1975 page_offset
+= iosize
;
1978 /* the get_extent function already copied into the page */
1979 if (test_range_bit(tree
, cur
, cur_end
, EXTENT_UPTODATE
, 1)) {
1980 check_page_uptodate(tree
, page
);
1981 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1983 page_offset
+= iosize
;
1986 /* we have an inline extent but it didn't get marked up
1987 * to date. Error out
1989 if (block_start
== EXTENT_MAP_INLINE
) {
1991 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1993 page_offset
+= iosize
;
1998 if (tree
->ops
&& tree
->ops
->readpage_io_hook
) {
1999 ret
= tree
->ops
->readpage_io_hook(page
, cur
,
2003 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2005 ret
= submit_extent_page(READ
, tree
, page
,
2006 sector
, disk_io_size
, page_offset
,
2008 end_bio_extent_readpage
, mirror_num
,
2012 *bio_flags
= this_bio_flag
;
2017 page_offset
+= iosize
;
2020 if (!PageError(page
))
2021 SetPageUptodate(page
);
2027 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2028 get_extent_t
*get_extent
)
2030 struct bio
*bio
= NULL
;
2031 unsigned long bio_flags
= 0;
2034 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, 0,
2037 submit_one_bio(READ
, bio
, 0, bio_flags
);
2041 static noinline
void update_nr_written(struct page
*page
,
2042 struct writeback_control
*wbc
,
2043 unsigned long nr_written
)
2045 wbc
->nr_to_write
-= nr_written
;
2046 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
2047 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
2048 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
2052 * the writepage semantics are similar to regular writepage. extent
2053 * records are inserted to lock ranges in the tree, and as dirty areas
2054 * are found, they are marked writeback. Then the lock bits are removed
2055 * and the end_io handler clears the writeback ranges
2057 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
2060 struct inode
*inode
= page
->mapping
->host
;
2061 struct extent_page_data
*epd
= data
;
2062 struct extent_io_tree
*tree
= epd
->tree
;
2063 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2065 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2069 u64 last_byte
= i_size_read(inode
);
2074 struct extent_map
*em
;
2075 struct block_device
*bdev
;
2078 size_t pg_offset
= 0;
2080 loff_t i_size
= i_size_read(inode
);
2081 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2087 unsigned long nr_written
= 0;
2089 if (wbc
->sync_mode
== WB_SYNC_ALL
)
2090 write_flags
= WRITE_SYNC_PLUG
;
2092 write_flags
= WRITE
;
2094 WARN_ON(!PageLocked(page
));
2095 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
2096 if (page
->index
> end_index
||
2097 (page
->index
== end_index
&& !pg_offset
)) {
2098 page
->mapping
->a_ops
->invalidatepage(page
, 0);
2103 if (page
->index
== end_index
) {
2106 userpage
= kmap_atomic(page
, KM_USER0
);
2107 memset(userpage
+ pg_offset
, 0,
2108 PAGE_CACHE_SIZE
- pg_offset
);
2109 kunmap_atomic(userpage
, KM_USER0
);
2110 flush_dcache_page(page
);
2114 set_page_extent_mapped(page
);
2116 delalloc_start
= start
;
2119 if (!epd
->extent_locked
) {
2120 u64 delalloc_to_write
;
2122 * make sure the wbc mapping index is at least updated
2125 update_nr_written(page
, wbc
, 0);
2127 while (delalloc_end
< page_end
) {
2128 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
2133 if (nr_delalloc
== 0) {
2134 delalloc_start
= delalloc_end
+ 1;
2137 tree
->ops
->fill_delalloc(inode
, page
, delalloc_start
,
2138 delalloc_end
, &page_started
,
2140 delalloc_to_write
= (delalloc_end
-
2141 max_t(u64
, page_offset(page
),
2142 delalloc_start
) + 1) >>
2144 if (wbc
->nr_to_write
< delalloc_to_write
) {
2145 wbc
->nr_to_write
= min_t(long, 8192,
2148 delalloc_start
= delalloc_end
+ 1;
2151 /* did the fill delalloc function already unlock and start
2157 * we've unlocked the page, so we can't update
2158 * the mapping's writeback index, just update
2161 wbc
->nr_to_write
-= nr_written
;
2165 lock_extent(tree
, start
, page_end
, GFP_NOFS
);
2167 unlock_start
= start
;
2169 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
2170 ret
= tree
->ops
->writepage_start_hook(page
, start
,
2172 if (ret
== -EAGAIN
) {
2173 unlock_extent(tree
, start
, page_end
, GFP_NOFS
);
2174 redirty_page_for_writepage(wbc
, page
);
2175 update_nr_written(page
, wbc
, nr_written
);
2183 * we don't want to touch the inode after unlocking the page,
2184 * so we update the mapping writeback index now
2186 update_nr_written(page
, wbc
, nr_written
+ 1);
2189 if (test_range_bit(tree
, start
, page_end
, EXTENT_DELALLOC
, 0))
2190 printk(KERN_ERR
"btrfs delalloc bits after lock_extent\n");
2192 if (last_byte
<= start
) {
2193 clear_extent_bit(tree
, start
, page_end
,
2194 EXTENT_LOCKED
| EXTENT_DIRTY
,
2196 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2197 tree
->ops
->writepage_end_io_hook(page
, start
,
2199 unlock_start
= page_end
+ 1;
2203 blocksize
= inode
->i_sb
->s_blocksize
;
2205 while (cur
<= end
) {
2206 if (cur
>= last_byte
) {
2207 unlock_extent(tree
, unlock_start
, page_end
, GFP_NOFS
);
2208 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2209 tree
->ops
->writepage_end_io_hook(page
, cur
,
2211 unlock_start
= page_end
+ 1;
2214 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
2216 if (IS_ERR(em
) || !em
) {
2221 extent_offset
= cur
- em
->start
;
2222 BUG_ON(extent_map_end(em
) <= cur
);
2224 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2225 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
2226 sector
= (em
->block_start
+ extent_offset
) >> 9;
2228 block_start
= em
->block_start
;
2229 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
2230 free_extent_map(em
);
2234 * compressed and inline extents are written through other
2237 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
2238 block_start
== EXTENT_MAP_INLINE
) {
2239 unlock_extent(tree
, unlock_start
, cur
+ iosize
- 1,
2243 * end_io notification does not happen here for
2244 * compressed extents
2246 if (!compressed
&& tree
->ops
&&
2247 tree
->ops
->writepage_end_io_hook
)
2248 tree
->ops
->writepage_end_io_hook(page
, cur
,
2251 else if (compressed
) {
2252 /* we don't want to end_page_writeback on
2253 * a compressed extent. this happens
2260 pg_offset
+= iosize
;
2264 /* leave this out until we have a page_mkwrite call */
2265 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
2268 pg_offset
+= iosize
;
2272 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
2273 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
2281 unsigned long max_nr
= end_index
+ 1;
2283 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
2284 if (!PageWriteback(page
)) {
2285 printk(KERN_ERR
"btrfs warning page %lu not "
2286 "writeback, cur %llu end %llu\n",
2287 page
->index
, (unsigned long long)cur
,
2288 (unsigned long long)end
);
2291 ret
= submit_extent_page(write_flags
, tree
, page
,
2292 sector
, iosize
, pg_offset
,
2293 bdev
, &epd
->bio
, max_nr
,
2294 end_bio_extent_writepage
,
2300 pg_offset
+= iosize
;
2305 /* make sure the mapping tag for page dirty gets cleared */
2306 set_page_writeback(page
);
2307 end_page_writeback(page
);
2309 if (unlock_start
<= page_end
)
2310 unlock_extent(tree
, unlock_start
, page_end
, GFP_NOFS
);
2319 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2320 * @mapping: address space structure to write
2321 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2322 * @writepage: function called for each page
2323 * @data: data passed to writepage function
2325 * If a page is already under I/O, write_cache_pages() skips it, even
2326 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2327 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2328 * and msync() need to guarantee that all the data which was dirty at the time
2329 * the call was made get new I/O started against them. If wbc->sync_mode is
2330 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2331 * existing IO to complete.
2333 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
2334 struct address_space
*mapping
,
2335 struct writeback_control
*wbc
,
2336 writepage_t writepage
, void *data
,
2337 void (*flush_fn
)(void *))
2341 struct pagevec pvec
;
2344 pgoff_t end
; /* Inclusive */
2346 int range_whole
= 0;
2348 pagevec_init(&pvec
, 0);
2349 if (wbc
->range_cyclic
) {
2350 index
= mapping
->writeback_index
; /* Start from prev offset */
2353 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2354 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
2355 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2360 while (!done
&& (index
<= end
) &&
2361 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
2362 PAGECACHE_TAG_DIRTY
, min(end
- index
,
2363 (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
2367 for (i
= 0; i
< nr_pages
; i
++) {
2368 struct page
*page
= pvec
.pages
[i
];
2371 * At this point we hold neither mapping->tree_lock nor
2372 * lock on the page itself: the page may be truncated or
2373 * invalidated (changing page->mapping to NULL), or even
2374 * swizzled back from swapper_space to tmpfs file
2377 if (tree
->ops
&& tree
->ops
->write_cache_pages_lock_hook
)
2378 tree
->ops
->write_cache_pages_lock_hook(page
);
2382 if (unlikely(page
->mapping
!= mapping
)) {
2387 if (!wbc
->range_cyclic
&& page
->index
> end
) {
2393 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
2394 if (PageWriteback(page
))
2396 wait_on_page_writeback(page
);
2399 if (PageWriteback(page
) ||
2400 !clear_page_dirty_for_io(page
)) {
2405 ret
= (*writepage
)(page
, wbc
, data
);
2407 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
2411 if (ret
|| wbc
->nr_to_write
<= 0)
2414 pagevec_release(&pvec
);
2417 if (!scanned
&& !done
) {
2419 * We hit the last page and there is more work to be done: wrap
2420 * back to the start of the file
2429 static void flush_epd_write_bio(struct extent_page_data
*epd
)
2433 submit_one_bio(WRITE_SYNC
, epd
->bio
, 0, 0);
2435 submit_one_bio(WRITE
, epd
->bio
, 0, 0);
2440 static noinline
void flush_write_bio(void *data
)
2442 struct extent_page_data
*epd
= data
;
2443 flush_epd_write_bio(epd
);
2446 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2447 get_extent_t
*get_extent
,
2448 struct writeback_control
*wbc
)
2451 struct address_space
*mapping
= page
->mapping
;
2452 struct extent_page_data epd
= {
2455 .get_extent
= get_extent
,
2457 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
2459 struct writeback_control wbc_writepages
= {
2461 .sync_mode
= wbc
->sync_mode
,
2462 .older_than_this
= NULL
,
2464 .range_start
= page_offset(page
) + PAGE_CACHE_SIZE
,
2465 .range_end
= (loff_t
)-1,
2468 ret
= __extent_writepage(page
, wbc
, &epd
);
2470 extent_write_cache_pages(tree
, mapping
, &wbc_writepages
,
2471 __extent_writepage
, &epd
, flush_write_bio
);
2472 flush_epd_write_bio(&epd
);
2476 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
2477 u64 start
, u64 end
, get_extent_t
*get_extent
,
2481 struct address_space
*mapping
= inode
->i_mapping
;
2483 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
2486 struct extent_page_data epd
= {
2489 .get_extent
= get_extent
,
2491 .sync_io
= mode
== WB_SYNC_ALL
,
2493 struct writeback_control wbc_writepages
= {
2494 .bdi
= inode
->i_mapping
->backing_dev_info
,
2496 .older_than_this
= NULL
,
2497 .nr_to_write
= nr_pages
* 2,
2498 .range_start
= start
,
2499 .range_end
= end
+ 1,
2502 while (start
<= end
) {
2503 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
2504 if (clear_page_dirty_for_io(page
))
2505 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
2507 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2508 tree
->ops
->writepage_end_io_hook(page
, start
,
2509 start
+ PAGE_CACHE_SIZE
- 1,
2513 page_cache_release(page
);
2514 start
+= PAGE_CACHE_SIZE
;
2517 flush_epd_write_bio(&epd
);
2521 int extent_writepages(struct extent_io_tree
*tree
,
2522 struct address_space
*mapping
,
2523 get_extent_t
*get_extent
,
2524 struct writeback_control
*wbc
)
2527 struct extent_page_data epd
= {
2530 .get_extent
= get_extent
,
2532 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
2535 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
2536 __extent_writepage
, &epd
,
2538 flush_epd_write_bio(&epd
);
2542 int extent_readpages(struct extent_io_tree
*tree
,
2543 struct address_space
*mapping
,
2544 struct list_head
*pages
, unsigned nr_pages
,
2545 get_extent_t get_extent
)
2547 struct bio
*bio
= NULL
;
2549 struct pagevec pvec
;
2550 unsigned long bio_flags
= 0;
2552 pagevec_init(&pvec
, 0);
2553 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
2554 struct page
*page
= list_entry(pages
->prev
, struct page
, lru
);
2556 prefetchw(&page
->flags
);
2557 list_del(&page
->lru
);
2559 * what we want to do here is call add_to_page_cache_lru,
2560 * but that isn't exported, so we reproduce it here
2562 if (!add_to_page_cache(page
, mapping
,
2563 page
->index
, GFP_KERNEL
)) {
2565 /* open coding of lru_cache_add, also not exported */
2566 page_cache_get(page
);
2567 if (!pagevec_add(&pvec
, page
))
2568 __pagevec_lru_add_file(&pvec
);
2569 __extent_read_full_page(tree
, page
, get_extent
,
2570 &bio
, 0, &bio_flags
);
2572 page_cache_release(page
);
2574 if (pagevec_count(&pvec
))
2575 __pagevec_lru_add_file(&pvec
);
2576 BUG_ON(!list_empty(pages
));
2578 submit_one_bio(READ
, bio
, 0, bio_flags
);
2583 * basic invalidatepage code, this waits on any locked or writeback
2584 * ranges corresponding to the page, and then deletes any extent state
2585 * records from the tree
2587 int extent_invalidatepage(struct extent_io_tree
*tree
,
2588 struct page
*page
, unsigned long offset
)
2590 u64 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
);
2591 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2592 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
2594 start
+= (offset
+ blocksize
- 1) & ~(blocksize
- 1);
2598 lock_extent(tree
, start
, end
, GFP_NOFS
);
2599 wait_on_page_writeback(page
);
2600 clear_extent_bit(tree
, start
, end
,
2601 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
,
2607 * simple commit_write call, set_range_dirty is used to mark both
2608 * the pages and the extent records as dirty
2610 int extent_commit_write(struct extent_io_tree
*tree
,
2611 struct inode
*inode
, struct page
*page
,
2612 unsigned from
, unsigned to
)
2614 loff_t pos
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
2616 set_page_extent_mapped(page
);
2617 set_page_dirty(page
);
2619 if (pos
> inode
->i_size
) {
2620 i_size_write(inode
, pos
);
2621 mark_inode_dirty(inode
);
2626 int extent_prepare_write(struct extent_io_tree
*tree
,
2627 struct inode
*inode
, struct page
*page
,
2628 unsigned from
, unsigned to
, get_extent_t
*get_extent
)
2630 u64 page_start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2631 u64 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
2633 u64 orig_block_start
;
2636 struct extent_map
*em
;
2637 unsigned blocksize
= 1 << inode
->i_blkbits
;
2638 size_t page_offset
= 0;
2639 size_t block_off_start
;
2640 size_t block_off_end
;
2646 set_page_extent_mapped(page
);
2648 block_start
= (page_start
+ from
) & ~((u64
)blocksize
- 1);
2649 block_end
= (page_start
+ to
- 1) | (blocksize
- 1);
2650 orig_block_start
= block_start
;
2652 lock_extent(tree
, page_start
, page_end
, GFP_NOFS
);
2653 while (block_start
<= block_end
) {
2654 em
= get_extent(inode
, page
, page_offset
, block_start
,
2655 block_end
- block_start
+ 1, 1);
2656 if (IS_ERR(em
) || !em
)
2659 cur_end
= min(block_end
, extent_map_end(em
) - 1);
2660 block_off_start
= block_start
& (PAGE_CACHE_SIZE
- 1);
2661 block_off_end
= block_off_start
+ blocksize
;
2662 isnew
= clear_extent_new(tree
, block_start
, cur_end
, GFP_NOFS
);
2664 if (!PageUptodate(page
) && isnew
&&
2665 (block_off_end
> to
|| block_off_start
< from
)) {
2668 kaddr
= kmap_atomic(page
, KM_USER0
);
2669 if (block_off_end
> to
)
2670 memset(kaddr
+ to
, 0, block_off_end
- to
);
2671 if (block_off_start
< from
)
2672 memset(kaddr
+ block_off_start
, 0,
2673 from
- block_off_start
);
2674 flush_dcache_page(page
);
2675 kunmap_atomic(kaddr
, KM_USER0
);
2677 if ((em
->block_start
!= EXTENT_MAP_HOLE
&&
2678 em
->block_start
!= EXTENT_MAP_INLINE
) &&
2679 !isnew
&& !PageUptodate(page
) &&
2680 (block_off_end
> to
|| block_off_start
< from
) &&
2681 !test_range_bit(tree
, block_start
, cur_end
,
2682 EXTENT_UPTODATE
, 1)) {
2684 u64 extent_offset
= block_start
- em
->start
;
2686 sector
= (em
->block_start
+ extent_offset
) >> 9;
2687 iosize
= (cur_end
- block_start
+ blocksize
) &
2688 ~((u64
)blocksize
- 1);
2690 * we've already got the extent locked, but we
2691 * need to split the state such that our end_bio
2692 * handler can clear the lock.
2694 set_extent_bit(tree
, block_start
,
2695 block_start
+ iosize
- 1,
2696 EXTENT_LOCKED
, 0, NULL
, GFP_NOFS
);
2697 ret
= submit_extent_page(READ
, tree
, page
,
2698 sector
, iosize
, page_offset
, em
->bdev
,
2700 end_bio_extent_preparewrite
, 0,
2703 block_start
= block_start
+ iosize
;
2705 set_extent_uptodate(tree
, block_start
, cur_end
,
2707 unlock_extent(tree
, block_start
, cur_end
, GFP_NOFS
);
2708 block_start
= cur_end
+ 1;
2710 page_offset
= block_start
& (PAGE_CACHE_SIZE
- 1);
2711 free_extent_map(em
);
2714 wait_extent_bit(tree
, orig_block_start
,
2715 block_end
, EXTENT_LOCKED
);
2717 check_page_uptodate(tree
, page
);
2719 /* FIXME, zero out newly allocated blocks on error */
2724 * a helper for releasepage, this tests for areas of the page that
2725 * are locked or under IO and drops the related state bits if it is safe
2728 int try_release_extent_state(struct extent_map_tree
*map
,
2729 struct extent_io_tree
*tree
, struct page
*page
,
2732 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2733 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2736 if (test_range_bit(tree
, start
, end
,
2737 EXTENT_IOBITS
| EXTENT_ORDERED
, 0))
2740 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
2742 clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
,
2749 * a helper for releasepage. As long as there are no locked extents
2750 * in the range corresponding to the page, both state records and extent
2751 * map records are removed
2753 int try_release_extent_mapping(struct extent_map_tree
*map
,
2754 struct extent_io_tree
*tree
, struct page
*page
,
2757 struct extent_map
*em
;
2758 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2759 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2761 if ((mask
& __GFP_WAIT
) &&
2762 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
2764 while (start
<= end
) {
2765 len
= end
- start
+ 1;
2766 write_lock(&map
->lock
);
2767 em
= lookup_extent_mapping(map
, start
, len
);
2768 if (!em
|| IS_ERR(em
)) {
2769 write_unlock(&map
->lock
);
2772 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
2773 em
->start
!= start
) {
2774 write_unlock(&map
->lock
);
2775 free_extent_map(em
);
2778 if (!test_range_bit(tree
, em
->start
,
2779 extent_map_end(em
) - 1,
2780 EXTENT_LOCKED
| EXTENT_WRITEBACK
|
2783 remove_extent_mapping(map
, em
);
2784 /* once for the rb tree */
2785 free_extent_map(em
);
2787 start
= extent_map_end(em
);
2788 write_unlock(&map
->lock
);
2791 free_extent_map(em
);
2794 return try_release_extent_state(map
, tree
, page
, mask
);
2797 sector_t
extent_bmap(struct address_space
*mapping
, sector_t iblock
,
2798 get_extent_t
*get_extent
)
2800 struct inode
*inode
= mapping
->host
;
2801 u64 start
= iblock
<< inode
->i_blkbits
;
2802 sector_t sector
= 0;
2803 size_t blksize
= (1 << inode
->i_blkbits
);
2804 struct extent_map
*em
;
2806 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, start
+ blksize
- 1,
2808 em
= get_extent(inode
, NULL
, 0, start
, blksize
, 0);
2809 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, start
+ blksize
- 1,
2811 if (!em
|| IS_ERR(em
))
2814 if (em
->block_start
> EXTENT_MAP_LAST_BYTE
)
2817 sector
= (em
->block_start
+ start
- em
->start
) >> inode
->i_blkbits
;
2819 free_extent_map(em
);
2823 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
2824 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
2828 u64 max
= start
+ len
;
2831 struct extent_map
*em
= NULL
;
2833 u64 em_start
= 0, em_len
= 0;
2834 unsigned long emflags
;
2840 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
,
2842 em
= get_extent(inode
, NULL
, 0, off
, max
- off
, 0);
2850 off
= em
->start
+ em
->len
;
2854 em_start
= em
->start
;
2860 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
2862 flags
|= FIEMAP_EXTENT_LAST
;
2863 } else if (em
->block_start
== EXTENT_MAP_HOLE
) {
2864 flags
|= FIEMAP_EXTENT_UNWRITTEN
;
2865 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
2866 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
2867 FIEMAP_EXTENT_NOT_ALIGNED
);
2868 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
2869 flags
|= (FIEMAP_EXTENT_DELALLOC
|
2870 FIEMAP_EXTENT_UNKNOWN
);
2872 disko
= em
->block_start
;
2874 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
2875 flags
|= FIEMAP_EXTENT_ENCODED
;
2877 emflags
= em
->flags
;
2878 free_extent_map(em
);
2882 em
= get_extent(inode
, NULL
, 0, off
, max
- off
, 0);
2889 emflags
= em
->flags
;
2891 if (test_bit(EXTENT_FLAG_VACANCY
, &emflags
)) {
2892 flags
|= FIEMAP_EXTENT_LAST
;
2896 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
2902 free_extent_map(em
);
2904 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
,
2909 static inline struct page
*extent_buffer_page(struct extent_buffer
*eb
,
2913 struct address_space
*mapping
;
2916 return eb
->first_page
;
2917 i
+= eb
->start
>> PAGE_CACHE_SHIFT
;
2918 mapping
= eb
->first_page
->mapping
;
2923 * extent_buffer_page is only called after pinning the page
2924 * by increasing the reference count. So we know the page must
2925 * be in the radix tree.
2928 p
= radix_tree_lookup(&mapping
->page_tree
, i
);
2934 static inline unsigned long num_extent_pages(u64 start
, u64 len
)
2936 return ((start
+ len
+ PAGE_CACHE_SIZE
- 1) >> PAGE_CACHE_SHIFT
) -
2937 (start
>> PAGE_CACHE_SHIFT
);
2940 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
2945 struct extent_buffer
*eb
= NULL
;
2947 unsigned long flags
;
2950 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
2953 spin_lock_init(&eb
->lock
);
2954 init_waitqueue_head(&eb
->lock_wq
);
2957 spin_lock_irqsave(&leak_lock
, flags
);
2958 list_add(&eb
->leak_list
, &buffers
);
2959 spin_unlock_irqrestore(&leak_lock
, flags
);
2961 atomic_set(&eb
->refs
, 1);
2966 static void __free_extent_buffer(struct extent_buffer
*eb
)
2969 unsigned long flags
;
2970 spin_lock_irqsave(&leak_lock
, flags
);
2971 list_del(&eb
->leak_list
);
2972 spin_unlock_irqrestore(&leak_lock
, flags
);
2974 kmem_cache_free(extent_buffer_cache
, eb
);
2977 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
2978 u64 start
, unsigned long len
,
2982 unsigned long num_pages
= num_extent_pages(start
, len
);
2984 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
2985 struct extent_buffer
*eb
;
2986 struct extent_buffer
*exists
= NULL
;
2988 struct address_space
*mapping
= tree
->mapping
;
2991 spin_lock(&tree
->buffer_lock
);
2992 eb
= buffer_search(tree
, start
);
2994 atomic_inc(&eb
->refs
);
2995 spin_unlock(&tree
->buffer_lock
);
2996 mark_page_accessed(eb
->first_page
);
2999 spin_unlock(&tree
->buffer_lock
);
3001 eb
= __alloc_extent_buffer(tree
, start
, len
, mask
);
3006 eb
->first_page
= page0
;
3009 page_cache_get(page0
);
3010 mark_page_accessed(page0
);
3011 set_page_extent_mapped(page0
);
3012 set_page_extent_head(page0
, len
);
3013 uptodate
= PageUptodate(page0
);
3017 for (; i
< num_pages
; i
++, index
++) {
3018 p
= find_or_create_page(mapping
, index
, mask
| __GFP_HIGHMEM
);
3023 set_page_extent_mapped(p
);
3024 mark_page_accessed(p
);
3027 set_page_extent_head(p
, len
);
3029 set_page_private(p
, EXTENT_PAGE_PRIVATE
);
3031 if (!PageUptodate(p
))
3036 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3038 spin_lock(&tree
->buffer_lock
);
3039 exists
= buffer_tree_insert(tree
, start
, &eb
->rb_node
);
3041 /* add one reference for the caller */
3042 atomic_inc(&exists
->refs
);
3043 spin_unlock(&tree
->buffer_lock
);
3046 spin_unlock(&tree
->buffer_lock
);
3048 /* add one reference for the tree */
3049 atomic_inc(&eb
->refs
);
3053 if (!atomic_dec_and_test(&eb
->refs
))
3055 for (index
= 1; index
< i
; index
++)
3056 page_cache_release(extent_buffer_page(eb
, index
));
3057 page_cache_release(extent_buffer_page(eb
, 0));
3058 __free_extent_buffer(eb
);
3062 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
3063 u64 start
, unsigned long len
,
3066 struct extent_buffer
*eb
;
3068 spin_lock(&tree
->buffer_lock
);
3069 eb
= buffer_search(tree
, start
);
3071 atomic_inc(&eb
->refs
);
3072 spin_unlock(&tree
->buffer_lock
);
3075 mark_page_accessed(eb
->first_page
);
3080 void free_extent_buffer(struct extent_buffer
*eb
)
3085 if (!atomic_dec_and_test(&eb
->refs
))
3091 int clear_extent_buffer_dirty(struct extent_io_tree
*tree
,
3092 struct extent_buffer
*eb
)
3095 unsigned long num_pages
;
3098 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3100 for (i
= 0; i
< num_pages
; i
++) {
3101 page
= extent_buffer_page(eb
, i
);
3102 if (!PageDirty(page
))
3107 set_page_extent_head(page
, eb
->len
);
3109 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
3111 clear_page_dirty_for_io(page
);
3112 spin_lock_irq(&page
->mapping
->tree_lock
);
3113 if (!PageDirty(page
)) {
3114 radix_tree_tag_clear(&page
->mapping
->page_tree
,
3116 PAGECACHE_TAG_DIRTY
);
3118 spin_unlock_irq(&page
->mapping
->tree_lock
);
3124 int wait_on_extent_buffer_writeback(struct extent_io_tree
*tree
,
3125 struct extent_buffer
*eb
)
3127 return wait_on_extent_writeback(tree
, eb
->start
,
3128 eb
->start
+ eb
->len
- 1);
3131 int set_extent_buffer_dirty(struct extent_io_tree
*tree
,
3132 struct extent_buffer
*eb
)
3135 unsigned long num_pages
;
3138 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
3139 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3140 for (i
= 0; i
< num_pages
; i
++)
3141 __set_page_dirty_nobuffers(extent_buffer_page(eb
, i
));
3145 int clear_extent_buffer_uptodate(struct extent_io_tree
*tree
,
3146 struct extent_buffer
*eb
)
3150 unsigned long num_pages
;
3152 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3153 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3155 clear_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3157 for (i
= 0; i
< num_pages
; i
++) {
3158 page
= extent_buffer_page(eb
, i
);
3160 ClearPageUptodate(page
);
3165 int set_extent_buffer_uptodate(struct extent_io_tree
*tree
,
3166 struct extent_buffer
*eb
)
3170 unsigned long num_pages
;
3172 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3174 set_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3176 for (i
= 0; i
< num_pages
; i
++) {
3177 page
= extent_buffer_page(eb
, i
);
3178 if ((i
== 0 && (eb
->start
& (PAGE_CACHE_SIZE
- 1))) ||
3179 ((i
== num_pages
- 1) &&
3180 ((eb
->start
+ eb
->len
) & (PAGE_CACHE_SIZE
- 1)))) {
3181 check_page_uptodate(tree
, page
);
3184 SetPageUptodate(page
);
3189 int extent_range_uptodate(struct extent_io_tree
*tree
,
3194 int pg_uptodate
= 1;
3196 unsigned long index
;
3198 ret
= test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1);
3201 while (start
<= end
) {
3202 index
= start
>> PAGE_CACHE_SHIFT
;
3203 page
= find_get_page(tree
->mapping
, index
);
3204 uptodate
= PageUptodate(page
);
3205 page_cache_release(page
);
3210 start
+= PAGE_CACHE_SIZE
;
3215 int extent_buffer_uptodate(struct extent_io_tree
*tree
,
3216 struct extent_buffer
*eb
)
3219 unsigned long num_pages
;
3222 int pg_uptodate
= 1;
3224 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
3227 ret
= test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3228 EXTENT_UPTODATE
, 1);
3232 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3233 for (i
= 0; i
< num_pages
; i
++) {
3234 page
= extent_buffer_page(eb
, i
);
3235 if (!PageUptodate(page
)) {
3243 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
3244 struct extent_buffer
*eb
,
3245 u64 start
, int wait
,
3246 get_extent_t
*get_extent
, int mirror_num
)
3249 unsigned long start_i
;
3253 int locked_pages
= 0;
3254 int all_uptodate
= 1;
3255 int inc_all_pages
= 0;
3256 unsigned long num_pages
;
3257 struct bio
*bio
= NULL
;
3258 unsigned long bio_flags
= 0;
3260 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
3263 if (test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3264 EXTENT_UPTODATE
, 1)) {
3269 WARN_ON(start
< eb
->start
);
3270 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
3271 (eb
->start
>> PAGE_CACHE_SHIFT
);
3276 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3277 for (i
= start_i
; i
< num_pages
; i
++) {
3278 page
= extent_buffer_page(eb
, i
);
3280 if (!trylock_page(page
))
3286 if (!PageUptodate(page
))
3291 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3295 for (i
= start_i
; i
< num_pages
; i
++) {
3296 page
= extent_buffer_page(eb
, i
);
3298 page_cache_get(page
);
3299 if (!PageUptodate(page
)) {
3302 ClearPageError(page
);
3303 err
= __extent_read_full_page(tree
, page
,
3305 mirror_num
, &bio_flags
);
3314 submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3319 for (i
= start_i
; i
< num_pages
; i
++) {
3320 page
= extent_buffer_page(eb
, i
);
3321 wait_on_page_locked(page
);
3322 if (!PageUptodate(page
))
3327 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3332 while (locked_pages
> 0) {
3333 page
= extent_buffer_page(eb
, i
);
3341 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
3342 unsigned long start
,
3349 char *dst
= (char *)dstv
;
3350 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3351 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3353 WARN_ON(start
> eb
->len
);
3354 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3356 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3359 page
= extent_buffer_page(eb
, i
);
3361 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
3362 kaddr
= kmap_atomic(page
, KM_USER1
);
3363 memcpy(dst
, kaddr
+ offset
, cur
);
3364 kunmap_atomic(kaddr
, KM_USER1
);
3373 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
3374 unsigned long min_len
, char **token
, char **map
,
3375 unsigned long *map_start
,
3376 unsigned long *map_len
, int km
)
3378 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
3381 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3382 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3383 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
3390 offset
= start_offset
;
3394 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
3397 if (start
+ min_len
> eb
->len
) {
3398 printk(KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
3399 "wanted %lu %lu\n", (unsigned long long)eb
->start
,
3400 eb
->len
, start
, min_len
);
3404 p
= extent_buffer_page(eb
, i
);
3405 kaddr
= kmap_atomic(p
, km
);
3407 *map
= kaddr
+ offset
;
3408 *map_len
= PAGE_CACHE_SIZE
- offset
;
3412 int map_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
3413 unsigned long min_len
,
3414 char **token
, char **map
,
3415 unsigned long *map_start
,
3416 unsigned long *map_len
, int km
)
3420 if (eb
->map_token
) {
3421 unmap_extent_buffer(eb
, eb
->map_token
, km
);
3422 eb
->map_token
= NULL
;
3425 err
= map_private_extent_buffer(eb
, start
, min_len
, token
, map
,
3426 map_start
, map_len
, km
);
3428 eb
->map_token
= *token
;
3430 eb
->map_start
= *map_start
;
3431 eb
->map_len
= *map_len
;
3436 void unmap_extent_buffer(struct extent_buffer
*eb
, char *token
, int km
)
3438 kunmap_atomic(token
, km
);
3441 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
3442 unsigned long start
,
3449 char *ptr
= (char *)ptrv
;
3450 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3451 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3454 WARN_ON(start
> eb
->len
);
3455 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3457 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3460 page
= extent_buffer_page(eb
, i
);
3462 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
3464 kaddr
= kmap_atomic(page
, KM_USER0
);
3465 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
3466 kunmap_atomic(kaddr
, KM_USER0
);
3478 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
3479 unsigned long start
, unsigned long len
)
3485 char *src
= (char *)srcv
;
3486 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3487 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3489 WARN_ON(start
> eb
->len
);
3490 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3492 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3495 page
= extent_buffer_page(eb
, i
);
3496 WARN_ON(!PageUptodate(page
));
3498 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
3499 kaddr
= kmap_atomic(page
, KM_USER1
);
3500 memcpy(kaddr
+ offset
, src
, cur
);
3501 kunmap_atomic(kaddr
, KM_USER1
);
3510 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
3511 unsigned long start
, unsigned long len
)
3517 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3518 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3520 WARN_ON(start
> eb
->len
);
3521 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3523 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3526 page
= extent_buffer_page(eb
, i
);
3527 WARN_ON(!PageUptodate(page
));
3529 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
3530 kaddr
= kmap_atomic(page
, KM_USER0
);
3531 memset(kaddr
+ offset
, c
, cur
);
3532 kunmap_atomic(kaddr
, KM_USER0
);
3540 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
3541 unsigned long dst_offset
, unsigned long src_offset
,
3544 u64 dst_len
= dst
->len
;
3549 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3550 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
3552 WARN_ON(src
->len
!= dst_len
);
3554 offset
= (start_offset
+ dst_offset
) &
3555 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3558 page
= extent_buffer_page(dst
, i
);
3559 WARN_ON(!PageUptodate(page
));
3561 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
3563 kaddr
= kmap_atomic(page
, KM_USER0
);
3564 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
3565 kunmap_atomic(kaddr
, KM_USER0
);
3574 static void move_pages(struct page
*dst_page
, struct page
*src_page
,
3575 unsigned long dst_off
, unsigned long src_off
,
3578 char *dst_kaddr
= kmap_atomic(dst_page
, KM_USER0
);
3579 if (dst_page
== src_page
) {
3580 memmove(dst_kaddr
+ dst_off
, dst_kaddr
+ src_off
, len
);
3582 char *src_kaddr
= kmap_atomic(src_page
, KM_USER1
);
3583 char *p
= dst_kaddr
+ dst_off
+ len
;
3584 char *s
= src_kaddr
+ src_off
+ len
;
3589 kunmap_atomic(src_kaddr
, KM_USER1
);
3591 kunmap_atomic(dst_kaddr
, KM_USER0
);
3594 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
3595 unsigned long dst_off
, unsigned long src_off
,
3598 char *dst_kaddr
= kmap_atomic(dst_page
, KM_USER0
);
3601 if (dst_page
!= src_page
)
3602 src_kaddr
= kmap_atomic(src_page
, KM_USER1
);
3604 src_kaddr
= dst_kaddr
;
3606 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
3607 kunmap_atomic(dst_kaddr
, KM_USER0
);
3608 if (dst_page
!= src_page
)
3609 kunmap_atomic(src_kaddr
, KM_USER1
);
3612 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
3613 unsigned long src_offset
, unsigned long len
)
3616 size_t dst_off_in_page
;
3617 size_t src_off_in_page
;
3618 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3619 unsigned long dst_i
;
3620 unsigned long src_i
;
3622 if (src_offset
+ len
> dst
->len
) {
3623 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
3624 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
3627 if (dst_offset
+ len
> dst
->len
) {
3628 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
3629 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
3634 dst_off_in_page
= (start_offset
+ dst_offset
) &
3635 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3636 src_off_in_page
= (start_offset
+ src_offset
) &
3637 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3639 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
3640 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
3642 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
3644 cur
= min_t(unsigned long, cur
,
3645 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
3647 copy_pages(extent_buffer_page(dst
, dst_i
),
3648 extent_buffer_page(dst
, src_i
),
3649 dst_off_in_page
, src_off_in_page
, cur
);
3657 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
3658 unsigned long src_offset
, unsigned long len
)
3661 size_t dst_off_in_page
;
3662 size_t src_off_in_page
;
3663 unsigned long dst_end
= dst_offset
+ len
- 1;
3664 unsigned long src_end
= src_offset
+ len
- 1;
3665 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3666 unsigned long dst_i
;
3667 unsigned long src_i
;
3669 if (src_offset
+ len
> dst
->len
) {
3670 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
3671 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
3674 if (dst_offset
+ len
> dst
->len
) {
3675 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
3676 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
3679 if (dst_offset
< src_offset
) {
3680 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
3684 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
3685 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
3687 dst_off_in_page
= (start_offset
+ dst_end
) &
3688 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3689 src_off_in_page
= (start_offset
+ src_end
) &
3690 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3692 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
3693 cur
= min(cur
, dst_off_in_page
+ 1);
3694 move_pages(extent_buffer_page(dst
, dst_i
),
3695 extent_buffer_page(dst
, src_i
),
3696 dst_off_in_page
- cur
+ 1,
3697 src_off_in_page
- cur
+ 1, cur
);
3705 int try_release_extent_buffer(struct extent_io_tree
*tree
, struct page
*page
)
3707 u64 start
= page_offset(page
);
3708 struct extent_buffer
*eb
;
3711 unsigned long num_pages
;
3713 spin_lock(&tree
->buffer_lock
);
3714 eb
= buffer_search(tree
, start
);
3718 if (atomic_read(&eb
->refs
) > 1) {
3722 if (test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3726 /* at this point we can safely release the extent buffer */
3727 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3728 for (i
= 0; i
< num_pages
; i
++)
3729 page_cache_release(extent_buffer_page(eb
, i
));
3730 rb_erase(&eb
->rb_node
, &tree
->buffer
);
3731 __free_extent_buffer(eb
);
3733 spin_unlock(&tree
->buffer_lock
);