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,
475 struct extent_state
**cached_state
,
478 struct extent_state
*state
;
479 struct extent_state
*cached
;
480 struct extent_state
*prealloc
= NULL
;
481 struct rb_node
*next_node
;
482 struct rb_node
*node
;
488 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
489 prealloc
= alloc_extent_state(mask
);
494 spin_lock(&tree
->lock
);
496 cached
= *cached_state
;
497 *cached_state
= NULL
;
499 if (cached
&& cached
->tree
&& cached
->start
== start
) {
500 atomic_dec(&cached
->refs
);
504 free_extent_state(cached
);
507 * this search will find the extents that end after
510 node
= tree_search(tree
, start
);
513 state
= rb_entry(node
, struct extent_state
, rb_node
);
515 if (state
->start
> end
)
517 WARN_ON(state
->end
< start
);
518 last_end
= state
->end
;
521 * | ---- desired range ---- |
523 * | ------------- state -------------- |
525 * We need to split the extent we found, and may flip
526 * bits on second half.
528 * If the extent we found extends past our range, we
529 * just split and search again. It'll get split again
530 * the next time though.
532 * If the extent we found is inside our range, we clear
533 * the desired bit on it.
536 if (state
->start
< start
) {
538 prealloc
= alloc_extent_state(GFP_ATOMIC
);
539 err
= split_state(tree
, state
, prealloc
, start
);
540 BUG_ON(err
== -EEXIST
);
544 if (state
->end
<= end
) {
545 set
|= clear_state_bit(tree
, state
, bits
,
547 if (last_end
== (u64
)-1)
549 start
= last_end
+ 1;
554 * | ---- desired range ---- |
556 * We need to split the extent, and clear the bit
559 if (state
->start
<= end
&& state
->end
> end
) {
561 prealloc
= alloc_extent_state(GFP_ATOMIC
);
562 err
= split_state(tree
, state
, prealloc
, end
+ 1);
563 BUG_ON(err
== -EEXIST
);
568 set
|= clear_state_bit(tree
, prealloc
, bits
,
574 if (state
->end
< end
&& prealloc
&& !need_resched())
575 next_node
= rb_next(&state
->rb_node
);
579 set
|= clear_state_bit(tree
, state
, bits
, wake
, delete);
580 if (last_end
== (u64
)-1)
582 start
= last_end
+ 1;
583 if (start
<= end
&& next_node
) {
584 state
= rb_entry(next_node
, struct extent_state
,
586 if (state
->start
== start
)
592 spin_unlock(&tree
->lock
);
594 free_extent_state(prealloc
);
601 spin_unlock(&tree
->lock
);
602 if (mask
& __GFP_WAIT
)
607 static int wait_on_state(struct extent_io_tree
*tree
,
608 struct extent_state
*state
)
609 __releases(tree
->lock
)
610 __acquires(tree
->lock
)
613 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
614 spin_unlock(&tree
->lock
);
616 spin_lock(&tree
->lock
);
617 finish_wait(&state
->wq
, &wait
);
622 * waits for one or more bits to clear on a range in the state tree.
623 * The range [start, end] is inclusive.
624 * The tree lock is taken by this function
626 int wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
, int bits
)
628 struct extent_state
*state
;
629 struct rb_node
*node
;
631 spin_lock(&tree
->lock
);
635 * this search will find all the extents that end after
638 node
= tree_search(tree
, start
);
642 state
= rb_entry(node
, struct extent_state
, rb_node
);
644 if (state
->start
> end
)
647 if (state
->state
& bits
) {
648 start
= state
->start
;
649 atomic_inc(&state
->refs
);
650 wait_on_state(tree
, state
);
651 free_extent_state(state
);
654 start
= state
->end
+ 1;
659 if (need_resched()) {
660 spin_unlock(&tree
->lock
);
662 spin_lock(&tree
->lock
);
666 spin_unlock(&tree
->lock
);
670 static void set_state_bits(struct extent_io_tree
*tree
,
671 struct extent_state
*state
,
674 if ((bits
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
675 u64 range
= state
->end
- state
->start
+ 1;
676 tree
->dirty_bytes
+= range
;
678 set_state_cb(tree
, state
, bits
);
679 state
->state
|= bits
;
682 static void cache_state(struct extent_state
*state
,
683 struct extent_state
**cached_ptr
)
685 if (cached_ptr
&& !(*cached_ptr
)) {
686 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
)) {
688 atomic_inc(&state
->refs
);
694 * set some bits on a range in the tree. This may require allocations or
695 * sleeping, so the gfp mask is used to indicate what is allowed.
697 * If any of the exclusive bits are set, this will fail with -EEXIST if some
698 * part of the range already has the desired bits set. The start of the
699 * existing range is returned in failed_start in this case.
701 * [start, end] is inclusive This takes the tree lock.
704 static int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
705 int bits
, int exclusive_bits
, u64
*failed_start
,
706 struct extent_state
**cached_state
,
709 struct extent_state
*state
;
710 struct extent_state
*prealloc
= NULL
;
711 struct rb_node
*node
;
717 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
718 prealloc
= alloc_extent_state(mask
);
723 spin_lock(&tree
->lock
);
724 if (cached_state
&& *cached_state
) {
725 state
= *cached_state
;
726 if (state
->start
== start
&& state
->tree
) {
727 node
= &state
->rb_node
;
732 * this search will find all the extents that end after
735 node
= tree_search(tree
, start
);
737 err
= insert_state(tree
, prealloc
, start
, end
, bits
);
739 BUG_ON(err
== -EEXIST
);
742 state
= rb_entry(node
, struct extent_state
, rb_node
);
744 last_start
= state
->start
;
745 last_end
= state
->end
;
748 * | ---- desired range ---- |
751 * Just lock what we found and keep going
753 if (state
->start
== start
&& state
->end
<= end
) {
754 struct rb_node
*next_node
;
755 if (state
->state
& exclusive_bits
) {
756 *failed_start
= state
->start
;
761 set_state_bits(tree
, state
, bits
);
762 cache_state(state
, cached_state
);
763 merge_state(tree
, state
);
764 if (last_end
== (u64
)-1)
767 start
= last_end
+ 1;
768 if (start
< end
&& prealloc
&& !need_resched()) {
769 next_node
= rb_next(node
);
771 state
= rb_entry(next_node
, struct extent_state
,
773 if (state
->start
== start
)
781 * | ---- desired range ---- |
784 * | ------------- state -------------- |
786 * We need to split the extent we found, and may flip bits on
789 * If the extent we found extends past our
790 * range, we just split and search again. It'll get split
791 * again the next time though.
793 * If the extent we found is inside our range, we set the
796 if (state
->start
< start
) {
797 if (state
->state
& exclusive_bits
) {
798 *failed_start
= start
;
802 err
= split_state(tree
, state
, prealloc
, start
);
803 BUG_ON(err
== -EEXIST
);
807 if (state
->end
<= end
) {
808 set_state_bits(tree
, state
, bits
);
809 cache_state(state
, cached_state
);
810 merge_state(tree
, state
);
811 if (last_end
== (u64
)-1)
813 start
= last_end
+ 1;
818 * | ---- desired range ---- |
819 * | state | or | state |
821 * There's a hole, we need to insert something in it and
822 * ignore the extent we found.
824 if (state
->start
> start
) {
826 if (end
< last_start
)
829 this_end
= last_start
- 1;
830 err
= insert_state(tree
, prealloc
, start
, this_end
,
832 cache_state(prealloc
, cached_state
);
834 BUG_ON(err
== -EEXIST
);
837 start
= this_end
+ 1;
841 * | ---- desired range ---- |
843 * We need to split the extent, and set the bit
846 if (state
->start
<= end
&& state
->end
> end
) {
847 if (state
->state
& exclusive_bits
) {
848 *failed_start
= start
;
852 err
= split_state(tree
, state
, prealloc
, end
+ 1);
853 BUG_ON(err
== -EEXIST
);
855 set_state_bits(tree
, prealloc
, bits
);
856 cache_state(prealloc
, cached_state
);
857 merge_state(tree
, prealloc
);
865 spin_unlock(&tree
->lock
);
867 free_extent_state(prealloc
);
874 spin_unlock(&tree
->lock
);
875 if (mask
& __GFP_WAIT
)
880 /* wrappers around set/clear extent bit */
881 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
884 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, 0, NULL
,
888 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
889 int bits
, gfp_t mask
)
891 return set_extent_bit(tree
, start
, end
, bits
, 0, NULL
,
895 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
896 int bits
, gfp_t mask
)
898 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, mask
);
901 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
904 return set_extent_bit(tree
, start
, end
,
905 EXTENT_DELALLOC
| EXTENT_DIRTY
| EXTENT_UPTODATE
,
906 0, NULL
, NULL
, mask
);
909 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
912 return clear_extent_bit(tree
, start
, end
,
913 EXTENT_DIRTY
| EXTENT_DELALLOC
, 0, 0,
917 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
920 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, NULL
,
924 static int clear_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
927 return clear_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, 0,
931 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
934 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, NULL
,
938 static int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
,
941 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0,
945 int wait_on_extent_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
947 return wait_extent_bit(tree
, start
, end
, EXTENT_WRITEBACK
);
951 * either insert or lock state struct between start and end use mask to tell
952 * us if waiting is desired.
954 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
955 int bits
, struct extent_state
**cached_state
, gfp_t mask
)
960 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
961 EXTENT_LOCKED
, &failed_start
,
963 if (err
== -EEXIST
&& (mask
& __GFP_WAIT
)) {
964 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
965 start
= failed_start
;
969 WARN_ON(start
> end
);
974 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
, gfp_t mask
)
976 return lock_extent_bits(tree
, start
, end
, 0, NULL
, mask
);
979 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
,
985 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
986 &failed_start
, NULL
, mask
);
987 if (err
== -EEXIST
) {
988 if (failed_start
> start
)
989 clear_extent_bit(tree
, start
, failed_start
- 1,
990 EXTENT_LOCKED
, 1, 0, NULL
, mask
);
996 int unlock_extent_cached(struct extent_io_tree
*tree
, u64 start
, u64 end
,
997 struct extent_state
**cached
, gfp_t mask
)
999 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, cached
,
1003 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1006 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, NULL
,
1011 * helper function to set pages and extents in the tree dirty
1013 int set_range_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1015 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1016 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1019 while (index
<= end_index
) {
1020 page
= find_get_page(tree
->mapping
, index
);
1022 __set_page_dirty_nobuffers(page
);
1023 page_cache_release(page
);
1030 * helper function to set both pages and extents in the tree writeback
1032 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1034 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1035 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1038 while (index
<= end_index
) {
1039 page
= find_get_page(tree
->mapping
, index
);
1041 set_page_writeback(page
);
1042 page_cache_release(page
);
1049 * find the first offset in the io tree with 'bits' set. zero is
1050 * returned if we find something, and *start_ret and *end_ret are
1051 * set to reflect the state struct that was found.
1053 * If nothing was found, 1 is returned, < 0 on error
1055 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1056 u64
*start_ret
, u64
*end_ret
, int bits
)
1058 struct rb_node
*node
;
1059 struct extent_state
*state
;
1062 spin_lock(&tree
->lock
);
1064 * this search will find all the extents that end after
1067 node
= tree_search(tree
, start
);
1072 state
= rb_entry(node
, struct extent_state
, rb_node
);
1073 if (state
->end
>= start
&& (state
->state
& bits
)) {
1074 *start_ret
= state
->start
;
1075 *end_ret
= state
->end
;
1079 node
= rb_next(node
);
1084 spin_unlock(&tree
->lock
);
1088 /* find the first state struct with 'bits' set after 'start', and
1089 * return it. tree->lock must be held. NULL will returned if
1090 * nothing was found after 'start'
1092 struct extent_state
*find_first_extent_bit_state(struct extent_io_tree
*tree
,
1093 u64 start
, int bits
)
1095 struct rb_node
*node
;
1096 struct extent_state
*state
;
1099 * this search will find all the extents that end after
1102 node
= tree_search(tree
, start
);
1107 state
= rb_entry(node
, struct extent_state
, rb_node
);
1108 if (state
->end
>= start
&& (state
->state
& bits
))
1111 node
= rb_next(node
);
1120 * find a contiguous range of bytes in the file marked as delalloc, not
1121 * more than 'max_bytes'. start and end are used to return the range,
1123 * 1 is returned if we find something, 0 if nothing was in the tree
1125 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1126 u64
*start
, u64
*end
, u64 max_bytes
)
1128 struct rb_node
*node
;
1129 struct extent_state
*state
;
1130 u64 cur_start
= *start
;
1132 u64 total_bytes
= 0;
1134 spin_lock(&tree
->lock
);
1137 * this search will find all the extents that end after
1140 node
= tree_search(tree
, cur_start
);
1148 state
= rb_entry(node
, struct extent_state
, rb_node
);
1149 if (found
&& (state
->start
!= cur_start
||
1150 (state
->state
& EXTENT_BOUNDARY
))) {
1153 if (!(state
->state
& EXTENT_DELALLOC
)) {
1159 *start
= state
->start
;
1162 cur_start
= state
->end
+ 1;
1163 node
= rb_next(node
);
1166 total_bytes
+= state
->end
- state
->start
+ 1;
1167 if (total_bytes
>= max_bytes
)
1171 spin_unlock(&tree
->lock
);
1175 static noinline
int __unlock_for_delalloc(struct inode
*inode
,
1176 struct page
*locked_page
,
1180 struct page
*pages
[16];
1181 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1182 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1183 unsigned long nr_pages
= end_index
- index
+ 1;
1186 if (index
== locked_page
->index
&& end_index
== index
)
1189 while (nr_pages
> 0) {
1190 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1191 min_t(unsigned long, nr_pages
,
1192 ARRAY_SIZE(pages
)), pages
);
1193 for (i
= 0; i
< ret
; i
++) {
1194 if (pages
[i
] != locked_page
)
1195 unlock_page(pages
[i
]);
1196 page_cache_release(pages
[i
]);
1205 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1206 struct page
*locked_page
,
1210 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1211 unsigned long start_index
= index
;
1212 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1213 unsigned long pages_locked
= 0;
1214 struct page
*pages
[16];
1215 unsigned long nrpages
;
1219 /* the caller is responsible for locking the start index */
1220 if (index
== locked_page
->index
&& index
== end_index
)
1223 /* skip the page at the start index */
1224 nrpages
= end_index
- index
+ 1;
1225 while (nrpages
> 0) {
1226 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1227 min_t(unsigned long,
1228 nrpages
, ARRAY_SIZE(pages
)), pages
);
1233 /* now we have an array of pages, lock them all */
1234 for (i
= 0; i
< ret
; i
++) {
1236 * the caller is taking responsibility for
1239 if (pages
[i
] != locked_page
) {
1240 lock_page(pages
[i
]);
1241 if (!PageDirty(pages
[i
]) ||
1242 pages
[i
]->mapping
!= inode
->i_mapping
) {
1244 unlock_page(pages
[i
]);
1245 page_cache_release(pages
[i
]);
1249 page_cache_release(pages
[i
]);
1258 if (ret
&& pages_locked
) {
1259 __unlock_for_delalloc(inode
, locked_page
,
1261 ((u64
)(start_index
+ pages_locked
- 1)) <<
1268 * find a contiguous range of bytes in the file marked as delalloc, not
1269 * more than 'max_bytes'. start and end are used to return the range,
1271 * 1 is returned if we find something, 0 if nothing was in the tree
1273 static noinline u64
find_lock_delalloc_range(struct inode
*inode
,
1274 struct extent_io_tree
*tree
,
1275 struct page
*locked_page
,
1276 u64
*start
, u64
*end
,
1282 struct extent_state
*cached_state
= NULL
;
1287 /* step one, find a bunch of delalloc bytes starting at start */
1288 delalloc_start
= *start
;
1290 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1292 if (!found
|| delalloc_end
<= *start
) {
1293 *start
= delalloc_start
;
1294 *end
= delalloc_end
;
1299 * start comes from the offset of locked_page. We have to lock
1300 * pages in order, so we can't process delalloc bytes before
1303 if (delalloc_start
< *start
)
1304 delalloc_start
= *start
;
1307 * make sure to limit the number of pages we try to lock down
1310 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
&& loops
)
1311 delalloc_end
= delalloc_start
+ PAGE_CACHE_SIZE
- 1;
1313 /* step two, lock all the pages after the page that has start */
1314 ret
= lock_delalloc_pages(inode
, locked_page
,
1315 delalloc_start
, delalloc_end
);
1316 if (ret
== -EAGAIN
) {
1317 /* some of the pages are gone, lets avoid looping by
1318 * shortening the size of the delalloc range we're searching
1320 free_extent_state(cached_state
);
1322 unsigned long offset
= (*start
) & (PAGE_CACHE_SIZE
- 1);
1323 max_bytes
= PAGE_CACHE_SIZE
- offset
;
1333 /* step three, lock the state bits for the whole range */
1334 lock_extent_bits(tree
, delalloc_start
, delalloc_end
,
1335 0, &cached_state
, GFP_NOFS
);
1337 /* then test to make sure it is all still delalloc */
1338 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1339 EXTENT_DELALLOC
, 1, cached_state
);
1341 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1342 &cached_state
, GFP_NOFS
);
1343 __unlock_for_delalloc(inode
, locked_page
,
1344 delalloc_start
, delalloc_end
);
1348 free_extent_state(cached_state
);
1349 *start
= delalloc_start
;
1350 *end
= delalloc_end
;
1355 int extent_clear_unlock_delalloc(struct inode
*inode
,
1356 struct extent_io_tree
*tree
,
1357 u64 start
, u64 end
, struct page
*locked_page
,
1360 int clear_delalloc
, int clear_dirty
,
1366 struct page
*pages
[16];
1367 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1368 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1369 unsigned long nr_pages
= end_index
- index
+ 1;
1374 clear_bits
|= EXTENT_LOCKED
;
1376 clear_bits
|= EXTENT_DIRTY
;
1379 clear_bits
|= EXTENT_DELALLOC
;
1381 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, NULL
, GFP_NOFS
);
1382 if (!(unlock_pages
|| clear_dirty
|| set_writeback
|| end_writeback
||
1386 while (nr_pages
> 0) {
1387 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1388 min_t(unsigned long,
1389 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1390 for (i
= 0; i
< ret
; i
++) {
1393 SetPagePrivate2(pages
[i
]);
1395 if (pages
[i
] == locked_page
) {
1396 page_cache_release(pages
[i
]);
1400 clear_page_dirty_for_io(pages
[i
]);
1402 set_page_writeback(pages
[i
]);
1404 end_page_writeback(pages
[i
]);
1406 unlock_page(pages
[i
]);
1407 page_cache_release(pages
[i
]);
1417 * count the number of bytes in the tree that have a given bit(s)
1418 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1419 * cached. The total number found is returned.
1421 u64
count_range_bits(struct extent_io_tree
*tree
,
1422 u64
*start
, u64 search_end
, u64 max_bytes
,
1425 struct rb_node
*node
;
1426 struct extent_state
*state
;
1427 u64 cur_start
= *start
;
1428 u64 total_bytes
= 0;
1431 if (search_end
<= cur_start
) {
1436 spin_lock(&tree
->lock
);
1437 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1438 total_bytes
= tree
->dirty_bytes
;
1442 * this search will find all the extents that end after
1445 node
= tree_search(tree
, cur_start
);
1450 state
= rb_entry(node
, struct extent_state
, rb_node
);
1451 if (state
->start
> search_end
)
1453 if (state
->end
>= cur_start
&& (state
->state
& bits
)) {
1454 total_bytes
+= min(search_end
, state
->end
) + 1 -
1455 max(cur_start
, state
->start
);
1456 if (total_bytes
>= max_bytes
)
1459 *start
= state
->start
;
1463 node
= rb_next(node
);
1468 spin_unlock(&tree
->lock
);
1473 * set the private field for a given byte offset in the tree. If there isn't
1474 * an extent_state there already, this does nothing.
1476 int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1478 struct rb_node
*node
;
1479 struct extent_state
*state
;
1482 spin_lock(&tree
->lock
);
1484 * this search will find all the extents that end after
1487 node
= tree_search(tree
, start
);
1492 state
= rb_entry(node
, struct extent_state
, rb_node
);
1493 if (state
->start
!= start
) {
1497 state
->private = private;
1499 spin_unlock(&tree
->lock
);
1503 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1505 struct rb_node
*node
;
1506 struct extent_state
*state
;
1509 spin_lock(&tree
->lock
);
1511 * this search will find all the extents that end after
1514 node
= tree_search(tree
, start
);
1519 state
= rb_entry(node
, struct extent_state
, rb_node
);
1520 if (state
->start
!= start
) {
1524 *private = state
->private;
1526 spin_unlock(&tree
->lock
);
1531 * searches a range in the state tree for a given mask.
1532 * If 'filled' == 1, this returns 1 only if every extent in the tree
1533 * has the bits set. Otherwise, 1 is returned if any bit in the
1534 * range is found set.
1536 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1537 int bits
, int filled
, struct extent_state
*cached
)
1539 struct extent_state
*state
= NULL
;
1540 struct rb_node
*node
;
1543 spin_lock(&tree
->lock
);
1544 if (cached
&& cached
->tree
&& cached
->start
== start
)
1545 node
= &cached
->rb_node
;
1547 node
= tree_search(tree
, start
);
1548 while (node
&& start
<= end
) {
1549 state
= rb_entry(node
, struct extent_state
, rb_node
);
1551 if (filled
&& state
->start
> start
) {
1556 if (state
->start
> end
)
1559 if (state
->state
& bits
) {
1563 } else if (filled
) {
1568 if (state
->end
== (u64
)-1)
1571 start
= state
->end
+ 1;
1574 node
= rb_next(node
);
1581 spin_unlock(&tree
->lock
);
1586 * helper function to set a given page up to date if all the
1587 * extents in the tree for that page are up to date
1589 static int check_page_uptodate(struct extent_io_tree
*tree
,
1592 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1593 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1594 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1595 SetPageUptodate(page
);
1600 * helper function to unlock a page if all the extents in the tree
1601 * for that page are unlocked
1603 static int check_page_locked(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_LOCKED
, 0, NULL
))
1614 * helper function to end page writeback if all the extents
1615 * in the tree for that page are done with writeback
1617 static int check_page_writeback(struct extent_io_tree
*tree
,
1620 end_page_writeback(page
);
1624 /* lots and lots of room for performance fixes in the end_bio funcs */
1627 * after a writepage IO is done, we need to:
1628 * clear the uptodate bits on error
1629 * clear the writeback bits in the extent tree for this IO
1630 * end_page_writeback if the page has no more pending IO
1632 * Scheduling is not allowed, so the extent state tree is expected
1633 * to have one and only one object corresponding to this IO.
1635 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
1637 int uptodate
= err
== 0;
1638 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1639 struct extent_io_tree
*tree
;
1646 struct page
*page
= bvec
->bv_page
;
1647 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1649 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1651 end
= start
+ bvec
->bv_len
- 1;
1653 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1658 if (--bvec
>= bio
->bi_io_vec
)
1659 prefetchw(&bvec
->bv_page
->flags
);
1660 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
1661 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
1662 end
, NULL
, uptodate
);
1667 if (!uptodate
&& tree
->ops
&&
1668 tree
->ops
->writepage_io_failed_hook
) {
1669 ret
= tree
->ops
->writepage_io_failed_hook(bio
, page
,
1672 uptodate
= (err
== 0);
1678 clear_extent_uptodate(tree
, start
, end
, GFP_NOFS
);
1679 ClearPageUptodate(page
);
1684 end_page_writeback(page
);
1686 check_page_writeback(tree
, page
);
1687 } while (bvec
>= bio
->bi_io_vec
);
1693 * after a readpage IO is done, we need to:
1694 * clear the uptodate bits on error
1695 * set the uptodate bits if things worked
1696 * set the page up to date if all extents in the tree are uptodate
1697 * clear the lock bit in the extent tree
1698 * unlock the page if there are no other extents locked for it
1700 * Scheduling is not allowed, so the extent state tree is expected
1701 * to have one and only one object corresponding to this IO.
1703 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
1705 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1706 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1707 struct extent_io_tree
*tree
;
1717 struct page
*page
= bvec
->bv_page
;
1718 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1720 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1722 end
= start
+ bvec
->bv_len
- 1;
1724 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1729 if (--bvec
>= bio
->bi_io_vec
)
1730 prefetchw(&bvec
->bv_page
->flags
);
1732 if (uptodate
&& tree
->ops
&& tree
->ops
->readpage_end_io_hook
) {
1733 ret
= tree
->ops
->readpage_end_io_hook(page
, start
, end
,
1738 if (!uptodate
&& tree
->ops
&&
1739 tree
->ops
->readpage_io_failed_hook
) {
1740 ret
= tree
->ops
->readpage_io_failed_hook(bio
, page
,
1744 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1752 set_extent_uptodate(tree
, start
, end
,
1755 unlock_extent(tree
, start
, end
, GFP_ATOMIC
);
1759 SetPageUptodate(page
);
1761 ClearPageUptodate(page
);
1767 check_page_uptodate(tree
, page
);
1769 ClearPageUptodate(page
);
1772 check_page_locked(tree
, page
);
1774 } while (bvec
>= bio
->bi_io_vec
);
1780 * IO done from prepare_write is pretty simple, we just unlock
1781 * the structs in the extent tree when done, and set the uptodate bits
1784 static void end_bio_extent_preparewrite(struct bio
*bio
, int err
)
1786 const int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1787 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1788 struct extent_io_tree
*tree
;
1793 struct page
*page
= bvec
->bv_page
;
1794 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1796 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1798 end
= start
+ bvec
->bv_len
- 1;
1800 if (--bvec
>= bio
->bi_io_vec
)
1801 prefetchw(&bvec
->bv_page
->flags
);
1804 set_extent_uptodate(tree
, start
, end
, GFP_ATOMIC
);
1806 ClearPageUptodate(page
);
1810 unlock_extent(tree
, start
, end
, GFP_ATOMIC
);
1812 } while (bvec
>= bio
->bi_io_vec
);
1818 extent_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
1823 bio
= bio_alloc(gfp_flags
, nr_vecs
);
1825 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
1826 while (!bio
&& (nr_vecs
/= 2))
1827 bio
= bio_alloc(gfp_flags
, nr_vecs
);
1832 bio
->bi_bdev
= bdev
;
1833 bio
->bi_sector
= first_sector
;
1838 static int submit_one_bio(int rw
, struct bio
*bio
, int mirror_num
,
1839 unsigned long bio_flags
)
1842 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1843 struct page
*page
= bvec
->bv_page
;
1844 struct extent_io_tree
*tree
= bio
->bi_private
;
1848 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) + bvec
->bv_offset
;
1849 end
= start
+ bvec
->bv_len
- 1;
1851 bio
->bi_private
= NULL
;
1855 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
1856 tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
1857 mirror_num
, bio_flags
);
1859 submit_bio(rw
, bio
);
1860 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
1866 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
1867 struct page
*page
, sector_t sector
,
1868 size_t size
, unsigned long offset
,
1869 struct block_device
*bdev
,
1870 struct bio
**bio_ret
,
1871 unsigned long max_pages
,
1872 bio_end_io_t end_io_func
,
1874 unsigned long prev_bio_flags
,
1875 unsigned long bio_flags
)
1881 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
1882 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
1883 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
1885 if (bio_ret
&& *bio_ret
) {
1888 contig
= bio
->bi_sector
== sector
;
1890 contig
= bio
->bi_sector
+ (bio
->bi_size
>> 9) ==
1893 if (prev_bio_flags
!= bio_flags
|| !contig
||
1894 (tree
->ops
&& tree
->ops
->merge_bio_hook
&&
1895 tree
->ops
->merge_bio_hook(page
, offset
, page_size
, bio
,
1897 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
1898 ret
= submit_one_bio(rw
, bio
, mirror_num
,
1905 if (this_compressed
)
1908 nr
= bio_get_nr_vecs(bdev
);
1910 bio
= extent_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
1912 bio_add_page(bio
, page
, page_size
, offset
);
1913 bio
->bi_end_io
= end_io_func
;
1914 bio
->bi_private
= tree
;
1919 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
1924 void set_page_extent_mapped(struct page
*page
)
1926 if (!PagePrivate(page
)) {
1927 SetPagePrivate(page
);
1928 page_cache_get(page
);
1929 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
1933 static void set_page_extent_head(struct page
*page
, unsigned long len
)
1935 set_page_private(page
, EXTENT_PAGE_PRIVATE_FIRST_PAGE
| len
<< 2);
1939 * basic readpage implementation. Locked extent state structs are inserted
1940 * into the tree that are removed when the IO is done (by the end_io
1943 static int __extent_read_full_page(struct extent_io_tree
*tree
,
1945 get_extent_t
*get_extent
,
1946 struct bio
**bio
, int mirror_num
,
1947 unsigned long *bio_flags
)
1949 struct inode
*inode
= page
->mapping
->host
;
1950 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1951 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
1955 u64 last_byte
= i_size_read(inode
);
1959 struct extent_map
*em
;
1960 struct block_device
*bdev
;
1963 size_t page_offset
= 0;
1965 size_t disk_io_size
;
1966 size_t blocksize
= inode
->i_sb
->s_blocksize
;
1967 unsigned long this_bio_flag
= 0;
1969 set_page_extent_mapped(page
);
1972 lock_extent(tree
, start
, end
, GFP_NOFS
);
1974 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
1976 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
1979 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
1980 userpage
= kmap_atomic(page
, KM_USER0
);
1981 memset(userpage
+ zero_offset
, 0, iosize
);
1982 flush_dcache_page(page
);
1983 kunmap_atomic(userpage
, KM_USER0
);
1986 while (cur
<= end
) {
1987 if (cur
>= last_byte
) {
1989 iosize
= PAGE_CACHE_SIZE
- page_offset
;
1990 userpage
= kmap_atomic(page
, KM_USER0
);
1991 memset(userpage
+ page_offset
, 0, iosize
);
1992 flush_dcache_page(page
);
1993 kunmap_atomic(userpage
, KM_USER0
);
1994 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
1996 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
1999 em
= get_extent(inode
, page
, page_offset
, cur
,
2001 if (IS_ERR(em
) || !em
) {
2003 unlock_extent(tree
, cur
, end
, GFP_NOFS
);
2006 extent_offset
= cur
- em
->start
;
2007 BUG_ON(extent_map_end(em
) <= cur
);
2010 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
2011 this_bio_flag
= EXTENT_BIO_COMPRESSED
;
2013 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2014 cur_end
= min(extent_map_end(em
) - 1, end
);
2015 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
2016 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2017 disk_io_size
= em
->block_len
;
2018 sector
= em
->block_start
>> 9;
2020 sector
= (em
->block_start
+ extent_offset
) >> 9;
2021 disk_io_size
= iosize
;
2024 block_start
= em
->block_start
;
2025 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2026 block_start
= EXTENT_MAP_HOLE
;
2027 free_extent_map(em
);
2030 /* we've found a hole, just zero and go on */
2031 if (block_start
== EXTENT_MAP_HOLE
) {
2033 userpage
= kmap_atomic(page
, KM_USER0
);
2034 memset(userpage
+ page_offset
, 0, iosize
);
2035 flush_dcache_page(page
);
2036 kunmap_atomic(userpage
, KM_USER0
);
2038 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2040 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2042 page_offset
+= iosize
;
2045 /* the get_extent function already copied into the page */
2046 if (test_range_bit(tree
, cur
, cur_end
,
2047 EXTENT_UPTODATE
, 1, NULL
)) {
2048 check_page_uptodate(tree
, page
);
2049 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2051 page_offset
+= iosize
;
2054 /* we have an inline extent but it didn't get marked up
2055 * to date. Error out
2057 if (block_start
== EXTENT_MAP_INLINE
) {
2059 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2061 page_offset
+= iosize
;
2066 if (tree
->ops
&& tree
->ops
->readpage_io_hook
) {
2067 ret
= tree
->ops
->readpage_io_hook(page
, cur
,
2071 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2073 ret
= submit_extent_page(READ
, tree
, page
,
2074 sector
, disk_io_size
, page_offset
,
2076 end_bio_extent_readpage
, mirror_num
,
2080 *bio_flags
= this_bio_flag
;
2085 page_offset
+= iosize
;
2088 if (!PageError(page
))
2089 SetPageUptodate(page
);
2095 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2096 get_extent_t
*get_extent
)
2098 struct bio
*bio
= NULL
;
2099 unsigned long bio_flags
= 0;
2102 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, 0,
2105 submit_one_bio(READ
, bio
, 0, bio_flags
);
2109 static noinline
void update_nr_written(struct page
*page
,
2110 struct writeback_control
*wbc
,
2111 unsigned long nr_written
)
2113 wbc
->nr_to_write
-= nr_written
;
2114 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
2115 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
2116 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
2120 * the writepage semantics are similar to regular writepage. extent
2121 * records are inserted to lock ranges in the tree, and as dirty areas
2122 * are found, they are marked writeback. Then the lock bits are removed
2123 * and the end_io handler clears the writeback ranges
2125 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
2128 struct inode
*inode
= page
->mapping
->host
;
2129 struct extent_page_data
*epd
= data
;
2130 struct extent_io_tree
*tree
= epd
->tree
;
2131 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2133 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2137 u64 last_byte
= i_size_read(inode
);
2142 struct extent_state
*cached_state
= NULL
;
2143 struct extent_map
*em
;
2144 struct block_device
*bdev
;
2147 size_t pg_offset
= 0;
2149 loff_t i_size
= i_size_read(inode
);
2150 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2156 unsigned long nr_written
= 0;
2158 if (wbc
->sync_mode
== WB_SYNC_ALL
)
2159 write_flags
= WRITE_SYNC_PLUG
;
2161 write_flags
= WRITE
;
2163 WARN_ON(!PageLocked(page
));
2164 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
2165 if (page
->index
> end_index
||
2166 (page
->index
== end_index
&& !pg_offset
)) {
2167 page
->mapping
->a_ops
->invalidatepage(page
, 0);
2172 if (page
->index
== end_index
) {
2175 userpage
= kmap_atomic(page
, KM_USER0
);
2176 memset(userpage
+ pg_offset
, 0,
2177 PAGE_CACHE_SIZE
- pg_offset
);
2178 kunmap_atomic(userpage
, KM_USER0
);
2179 flush_dcache_page(page
);
2183 set_page_extent_mapped(page
);
2185 delalloc_start
= start
;
2188 if (!epd
->extent_locked
) {
2189 u64 delalloc_to_write
= 0;
2191 * make sure the wbc mapping index is at least updated
2194 update_nr_written(page
, wbc
, 0);
2196 while (delalloc_end
< page_end
) {
2197 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
2202 if (nr_delalloc
== 0) {
2203 delalloc_start
= delalloc_end
+ 1;
2206 tree
->ops
->fill_delalloc(inode
, page
, delalloc_start
,
2207 delalloc_end
, &page_started
,
2210 * delalloc_end is already one less than the total
2211 * length, so we don't subtract one from
2214 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
2217 delalloc_start
= delalloc_end
+ 1;
2219 if (wbc
->nr_to_write
< delalloc_to_write
) {
2222 if (delalloc_to_write
< thresh
* 2)
2223 thresh
= delalloc_to_write
;
2224 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
2228 /* did the fill delalloc function already unlock and start
2234 * we've unlocked the page, so we can't update
2235 * the mapping's writeback index, just update
2238 wbc
->nr_to_write
-= nr_written
;
2242 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
2243 ret
= tree
->ops
->writepage_start_hook(page
, start
,
2245 if (ret
== -EAGAIN
) {
2246 redirty_page_for_writepage(wbc
, page
);
2247 update_nr_written(page
, wbc
, nr_written
);
2255 * we don't want to touch the inode after unlocking the page,
2256 * so we update the mapping writeback index now
2258 update_nr_written(page
, wbc
, nr_written
+ 1);
2261 if (last_byte
<= start
) {
2262 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2263 tree
->ops
->writepage_end_io_hook(page
, start
,
2265 unlock_start
= page_end
+ 1;
2269 blocksize
= inode
->i_sb
->s_blocksize
;
2271 while (cur
<= end
) {
2272 if (cur
>= last_byte
) {
2273 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2274 tree
->ops
->writepage_end_io_hook(page
, cur
,
2276 unlock_start
= page_end
+ 1;
2279 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
2281 if (IS_ERR(em
) || !em
) {
2286 extent_offset
= cur
- em
->start
;
2287 BUG_ON(extent_map_end(em
) <= cur
);
2289 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2290 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
2291 sector
= (em
->block_start
+ extent_offset
) >> 9;
2293 block_start
= em
->block_start
;
2294 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
2295 free_extent_map(em
);
2299 * compressed and inline extents are written through other
2302 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
2303 block_start
== EXTENT_MAP_INLINE
) {
2305 * end_io notification does not happen here for
2306 * compressed extents
2308 if (!compressed
&& tree
->ops
&&
2309 tree
->ops
->writepage_end_io_hook
)
2310 tree
->ops
->writepage_end_io_hook(page
, cur
,
2313 else if (compressed
) {
2314 /* we don't want to end_page_writeback on
2315 * a compressed extent. this happens
2322 pg_offset
+= iosize
;
2326 /* leave this out until we have a page_mkwrite call */
2327 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
2328 EXTENT_DIRTY
, 0, NULL
)) {
2330 pg_offset
+= iosize
;
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(KERN_ERR
"btrfs warning page %lu not "
2348 "writeback, cur %llu end %llu\n",
2349 page
->index
, (unsigned long long)cur
,
2350 (unsigned long long)end
);
2353 ret
= submit_extent_page(write_flags
, tree
, page
,
2354 sector
, iosize
, pg_offset
,
2355 bdev
, &epd
->bio
, max_nr
,
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
);
2375 /* drop our reference on any cached states */
2376 free_extent_state(cached_state
);
2381 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2382 * @mapping: address space structure to write
2383 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2384 * @writepage: function called for each page
2385 * @data: data passed to writepage function
2387 * If a page is already under I/O, write_cache_pages() skips it, even
2388 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2389 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2390 * and msync() need to guarantee that all the data which was dirty at the time
2391 * the call was made get new I/O started against them. If wbc->sync_mode is
2392 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2393 * existing IO to complete.
2395 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
2396 struct address_space
*mapping
,
2397 struct writeback_control
*wbc
,
2398 writepage_t writepage
, void *data
,
2399 void (*flush_fn
)(void *))
2403 int nr_to_write_done
= 0;
2404 struct pagevec pvec
;
2407 pgoff_t end
; /* Inclusive */
2409 int range_whole
= 0;
2411 pagevec_init(&pvec
, 0);
2412 if (wbc
->range_cyclic
) {
2413 index
= mapping
->writeback_index
; /* Start from prev offset */
2416 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2417 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
2418 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2423 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
2424 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
2425 PAGECACHE_TAG_DIRTY
, min(end
- index
,
2426 (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
2430 for (i
= 0; i
< nr_pages
; i
++) {
2431 struct page
*page
= pvec
.pages
[i
];
2434 * At this point we hold neither mapping->tree_lock nor
2435 * lock on the page itself: the page may be truncated or
2436 * invalidated (changing page->mapping to NULL), or even
2437 * swizzled back from swapper_space to tmpfs file
2440 if (tree
->ops
&& tree
->ops
->write_cache_pages_lock_hook
)
2441 tree
->ops
->write_cache_pages_lock_hook(page
);
2445 if (unlikely(page
->mapping
!= mapping
)) {
2450 if (!wbc
->range_cyclic
&& page
->index
> end
) {
2456 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
2457 if (PageWriteback(page
))
2459 wait_on_page_writeback(page
);
2462 if (PageWriteback(page
) ||
2463 !clear_page_dirty_for_io(page
)) {
2468 ret
= (*writepage
)(page
, wbc
, data
);
2470 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
2478 * the filesystem may choose to bump up nr_to_write.
2479 * We have to make sure to honor the new nr_to_write
2482 nr_to_write_done
= wbc
->nr_to_write
<= 0;
2484 pagevec_release(&pvec
);
2487 if (!scanned
&& !done
) {
2489 * We hit the last page and there is more work to be done: wrap
2490 * back to the start of the file
2499 static void flush_epd_write_bio(struct extent_page_data
*epd
)
2503 submit_one_bio(WRITE_SYNC
, epd
->bio
, 0, 0);
2505 submit_one_bio(WRITE
, epd
->bio
, 0, 0);
2510 static noinline
void flush_write_bio(void *data
)
2512 struct extent_page_data
*epd
= data
;
2513 flush_epd_write_bio(epd
);
2516 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2517 get_extent_t
*get_extent
,
2518 struct writeback_control
*wbc
)
2521 struct address_space
*mapping
= page
->mapping
;
2522 struct extent_page_data epd
= {
2525 .get_extent
= get_extent
,
2527 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
2529 struct writeback_control wbc_writepages
= {
2531 .sync_mode
= wbc
->sync_mode
,
2532 .older_than_this
= NULL
,
2534 .range_start
= page_offset(page
) + PAGE_CACHE_SIZE
,
2535 .range_end
= (loff_t
)-1,
2538 ret
= __extent_writepage(page
, wbc
, &epd
);
2540 extent_write_cache_pages(tree
, mapping
, &wbc_writepages
,
2541 __extent_writepage
, &epd
, flush_write_bio
);
2542 flush_epd_write_bio(&epd
);
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
,
2561 .sync_io
= mode
== WB_SYNC_ALL
,
2563 struct writeback_control wbc_writepages
= {
2564 .bdi
= inode
->i_mapping
->backing_dev_info
,
2566 .older_than_this
= NULL
,
2567 .nr_to_write
= nr_pages
* 2,
2568 .range_start
= start
,
2569 .range_end
= end
+ 1,
2572 while (start
<= end
) {
2573 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
2574 if (clear_page_dirty_for_io(page
))
2575 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
2577 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2578 tree
->ops
->writepage_end_io_hook(page
, start
,
2579 start
+ PAGE_CACHE_SIZE
- 1,
2583 page_cache_release(page
);
2584 start
+= PAGE_CACHE_SIZE
;
2587 flush_epd_write_bio(&epd
);
2591 int extent_writepages(struct extent_io_tree
*tree
,
2592 struct address_space
*mapping
,
2593 get_extent_t
*get_extent
,
2594 struct writeback_control
*wbc
)
2597 struct extent_page_data epd
= {
2600 .get_extent
= get_extent
,
2602 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
2605 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
2606 __extent_writepage
, &epd
,
2608 flush_epd_write_bio(&epd
);
2612 int extent_readpages(struct extent_io_tree
*tree
,
2613 struct address_space
*mapping
,
2614 struct list_head
*pages
, unsigned nr_pages
,
2615 get_extent_t get_extent
)
2617 struct bio
*bio
= NULL
;
2619 struct pagevec pvec
;
2620 unsigned long bio_flags
= 0;
2622 pagevec_init(&pvec
, 0);
2623 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
2624 struct page
*page
= list_entry(pages
->prev
, struct page
, lru
);
2626 prefetchw(&page
->flags
);
2627 list_del(&page
->lru
);
2629 * what we want to do here is call add_to_page_cache_lru,
2630 * but that isn't exported, so we reproduce it here
2632 if (!add_to_page_cache(page
, mapping
,
2633 page
->index
, GFP_KERNEL
)) {
2635 /* open coding of lru_cache_add, also not exported */
2636 page_cache_get(page
);
2637 if (!pagevec_add(&pvec
, page
))
2638 __pagevec_lru_add_file(&pvec
);
2639 __extent_read_full_page(tree
, page
, get_extent
,
2640 &bio
, 0, &bio_flags
);
2642 page_cache_release(page
);
2644 if (pagevec_count(&pvec
))
2645 __pagevec_lru_add_file(&pvec
);
2646 BUG_ON(!list_empty(pages
));
2648 submit_one_bio(READ
, bio
, 0, bio_flags
);
2653 * basic invalidatepage code, this waits on any locked or writeback
2654 * ranges corresponding to the page, and then deletes any extent state
2655 * records from the tree
2657 int extent_invalidatepage(struct extent_io_tree
*tree
,
2658 struct page
*page
, unsigned long offset
)
2660 u64 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
);
2661 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2662 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
2664 start
+= (offset
+ blocksize
- 1) & ~(blocksize
- 1);
2668 lock_extent(tree
, start
, end
, GFP_NOFS
);
2669 wait_on_page_writeback(page
);
2670 clear_extent_bit(tree
, start
, end
,
2671 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
,
2672 1, 1, NULL
, GFP_NOFS
);
2677 * simple commit_write call, set_range_dirty is used to mark both
2678 * the pages and the extent records as dirty
2680 int extent_commit_write(struct extent_io_tree
*tree
,
2681 struct inode
*inode
, struct page
*page
,
2682 unsigned from
, unsigned to
)
2684 loff_t pos
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
2686 set_page_extent_mapped(page
);
2687 set_page_dirty(page
);
2689 if (pos
> inode
->i_size
) {
2690 i_size_write(inode
, pos
);
2691 mark_inode_dirty(inode
);
2696 int extent_prepare_write(struct extent_io_tree
*tree
,
2697 struct inode
*inode
, struct page
*page
,
2698 unsigned from
, unsigned to
, get_extent_t
*get_extent
)
2700 u64 page_start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2701 u64 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
2703 u64 orig_block_start
;
2706 struct extent_map
*em
;
2707 unsigned blocksize
= 1 << inode
->i_blkbits
;
2708 size_t page_offset
= 0;
2709 size_t block_off_start
;
2710 size_t block_off_end
;
2716 set_page_extent_mapped(page
);
2718 block_start
= (page_start
+ from
) & ~((u64
)blocksize
- 1);
2719 block_end
= (page_start
+ to
- 1) | (blocksize
- 1);
2720 orig_block_start
= block_start
;
2722 lock_extent(tree
, page_start
, page_end
, GFP_NOFS
);
2723 while (block_start
<= block_end
) {
2724 em
= get_extent(inode
, page
, page_offset
, block_start
,
2725 block_end
- block_start
+ 1, 1);
2726 if (IS_ERR(em
) || !em
)
2729 cur_end
= min(block_end
, extent_map_end(em
) - 1);
2730 block_off_start
= block_start
& (PAGE_CACHE_SIZE
- 1);
2731 block_off_end
= block_off_start
+ blocksize
;
2732 isnew
= clear_extent_new(tree
, block_start
, cur_end
, GFP_NOFS
);
2734 if (!PageUptodate(page
) && isnew
&&
2735 (block_off_end
> to
|| block_off_start
< from
)) {
2738 kaddr
= kmap_atomic(page
, KM_USER0
);
2739 if (block_off_end
> to
)
2740 memset(kaddr
+ to
, 0, block_off_end
- to
);
2741 if (block_off_start
< from
)
2742 memset(kaddr
+ block_off_start
, 0,
2743 from
- block_off_start
);
2744 flush_dcache_page(page
);
2745 kunmap_atomic(kaddr
, KM_USER0
);
2747 if ((em
->block_start
!= EXTENT_MAP_HOLE
&&
2748 em
->block_start
!= EXTENT_MAP_INLINE
) &&
2749 !isnew
&& !PageUptodate(page
) &&
2750 (block_off_end
> to
|| block_off_start
< from
) &&
2751 !test_range_bit(tree
, block_start
, cur_end
,
2752 EXTENT_UPTODATE
, 1, NULL
)) {
2754 u64 extent_offset
= block_start
- em
->start
;
2756 sector
= (em
->block_start
+ extent_offset
) >> 9;
2757 iosize
= (cur_end
- block_start
+ blocksize
) &
2758 ~((u64
)blocksize
- 1);
2760 * we've already got the extent locked, but we
2761 * need to split the state such that our end_bio
2762 * handler can clear the lock.
2764 set_extent_bit(tree
, block_start
,
2765 block_start
+ iosize
- 1,
2766 EXTENT_LOCKED
, 0, NULL
, NULL
, GFP_NOFS
);
2767 ret
= submit_extent_page(READ
, tree
, page
,
2768 sector
, iosize
, page_offset
, em
->bdev
,
2770 end_bio_extent_preparewrite
, 0,
2773 block_start
= block_start
+ iosize
;
2775 set_extent_uptodate(tree
, block_start
, cur_end
,
2777 unlock_extent(tree
, block_start
, cur_end
, GFP_NOFS
);
2778 block_start
= cur_end
+ 1;
2780 page_offset
= block_start
& (PAGE_CACHE_SIZE
- 1);
2781 free_extent_map(em
);
2784 wait_extent_bit(tree
, orig_block_start
,
2785 block_end
, EXTENT_LOCKED
);
2787 check_page_uptodate(tree
, page
);
2789 /* FIXME, zero out newly allocated blocks on error */
2794 * a helper for releasepage, this tests for areas of the page that
2795 * are locked or under IO and drops the related state bits if it is safe
2798 int try_release_extent_state(struct extent_map_tree
*map
,
2799 struct extent_io_tree
*tree
, struct page
*page
,
2802 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2803 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2806 if (test_range_bit(tree
, start
, end
,
2807 EXTENT_IOBITS
, 0, NULL
))
2810 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
2813 * at this point we can safely clear everything except the
2814 * locked bit and the nodatasum bit
2816 clear_extent_bit(tree
, start
, end
,
2817 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
2824 * a helper for releasepage. As long as there are no locked extents
2825 * in the range corresponding to the page, both state records and extent
2826 * map records are removed
2828 int try_release_extent_mapping(struct extent_map_tree
*map
,
2829 struct extent_io_tree
*tree
, struct page
*page
,
2832 struct extent_map
*em
;
2833 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2834 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2836 if ((mask
& __GFP_WAIT
) &&
2837 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
2839 while (start
<= end
) {
2840 len
= end
- start
+ 1;
2841 write_lock(&map
->lock
);
2842 em
= lookup_extent_mapping(map
, start
, len
);
2843 if (!em
|| IS_ERR(em
)) {
2844 write_unlock(&map
->lock
);
2847 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
2848 em
->start
!= start
) {
2849 write_unlock(&map
->lock
);
2850 free_extent_map(em
);
2853 if (!test_range_bit(tree
, em
->start
,
2854 extent_map_end(em
) - 1,
2855 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
2857 remove_extent_mapping(map
, em
);
2858 /* once for the rb tree */
2859 free_extent_map(em
);
2861 start
= extent_map_end(em
);
2862 write_unlock(&map
->lock
);
2865 free_extent_map(em
);
2868 return try_release_extent_state(map
, tree
, page
, mask
);
2871 sector_t
extent_bmap(struct address_space
*mapping
, sector_t iblock
,
2872 get_extent_t
*get_extent
)
2874 struct inode
*inode
= mapping
->host
;
2875 u64 start
= iblock
<< inode
->i_blkbits
;
2876 sector_t sector
= 0;
2877 size_t blksize
= (1 << inode
->i_blkbits
);
2878 struct extent_map
*em
;
2880 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, start
+ blksize
- 1,
2882 em
= get_extent(inode
, NULL
, 0, start
, blksize
, 0);
2883 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, start
+ blksize
- 1,
2885 if (!em
|| IS_ERR(em
))
2888 if (em
->block_start
> EXTENT_MAP_LAST_BYTE
)
2891 sector
= (em
->block_start
+ start
- em
->start
) >> inode
->i_blkbits
;
2893 free_extent_map(em
);
2897 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
2898 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
2902 u64 max
= start
+ len
;
2905 struct extent_map
*em
= NULL
;
2907 u64 em_start
= 0, em_len
= 0;
2908 unsigned long emflags
;
2914 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
,
2916 em
= get_extent(inode
, NULL
, 0, off
, max
- off
, 0);
2924 off
= em
->start
+ em
->len
;
2928 em_start
= em
->start
;
2934 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
2936 flags
|= FIEMAP_EXTENT_LAST
;
2937 } else if (em
->block_start
== EXTENT_MAP_HOLE
) {
2938 flags
|= FIEMAP_EXTENT_UNWRITTEN
;
2939 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
2940 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
2941 FIEMAP_EXTENT_NOT_ALIGNED
);
2942 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
2943 flags
|= (FIEMAP_EXTENT_DELALLOC
|
2944 FIEMAP_EXTENT_UNKNOWN
);
2946 disko
= em
->block_start
;
2948 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
2949 flags
|= FIEMAP_EXTENT_ENCODED
;
2951 emflags
= em
->flags
;
2952 free_extent_map(em
);
2956 em
= get_extent(inode
, NULL
, 0, off
, max
- off
, 0);
2963 emflags
= em
->flags
;
2965 if (test_bit(EXTENT_FLAG_VACANCY
, &emflags
)) {
2966 flags
|= FIEMAP_EXTENT_LAST
;
2970 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
2976 free_extent_map(em
);
2978 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
,
2983 static inline struct page
*extent_buffer_page(struct extent_buffer
*eb
,
2987 struct address_space
*mapping
;
2990 return eb
->first_page
;
2991 i
+= eb
->start
>> PAGE_CACHE_SHIFT
;
2992 mapping
= eb
->first_page
->mapping
;
2997 * extent_buffer_page is only called after pinning the page
2998 * by increasing the reference count. So we know the page must
2999 * be in the radix tree.
3002 p
= radix_tree_lookup(&mapping
->page_tree
, i
);
3008 static inline unsigned long num_extent_pages(u64 start
, u64 len
)
3010 return ((start
+ len
+ PAGE_CACHE_SIZE
- 1) >> PAGE_CACHE_SHIFT
) -
3011 (start
>> PAGE_CACHE_SHIFT
);
3014 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
3019 struct extent_buffer
*eb
= NULL
;
3021 unsigned long flags
;
3024 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
3027 spin_lock_init(&eb
->lock
);
3028 init_waitqueue_head(&eb
->lock_wq
);
3031 spin_lock_irqsave(&leak_lock
, flags
);
3032 list_add(&eb
->leak_list
, &buffers
);
3033 spin_unlock_irqrestore(&leak_lock
, flags
);
3035 atomic_set(&eb
->refs
, 1);
3040 static void __free_extent_buffer(struct extent_buffer
*eb
)
3043 unsigned long flags
;
3044 spin_lock_irqsave(&leak_lock
, flags
);
3045 list_del(&eb
->leak_list
);
3046 spin_unlock_irqrestore(&leak_lock
, flags
);
3048 kmem_cache_free(extent_buffer_cache
, eb
);
3051 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
3052 u64 start
, unsigned long len
,
3056 unsigned long num_pages
= num_extent_pages(start
, len
);
3058 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
3059 struct extent_buffer
*eb
;
3060 struct extent_buffer
*exists
= NULL
;
3062 struct address_space
*mapping
= tree
->mapping
;
3065 spin_lock(&tree
->buffer_lock
);
3066 eb
= buffer_search(tree
, start
);
3068 atomic_inc(&eb
->refs
);
3069 spin_unlock(&tree
->buffer_lock
);
3070 mark_page_accessed(eb
->first_page
);
3073 spin_unlock(&tree
->buffer_lock
);
3075 eb
= __alloc_extent_buffer(tree
, start
, len
, mask
);
3080 eb
->first_page
= page0
;
3083 page_cache_get(page0
);
3084 mark_page_accessed(page0
);
3085 set_page_extent_mapped(page0
);
3086 set_page_extent_head(page0
, len
);
3087 uptodate
= PageUptodate(page0
);
3091 for (; i
< num_pages
; i
++, index
++) {
3092 p
= find_or_create_page(mapping
, index
, mask
| __GFP_HIGHMEM
);
3097 set_page_extent_mapped(p
);
3098 mark_page_accessed(p
);
3101 set_page_extent_head(p
, len
);
3103 set_page_private(p
, EXTENT_PAGE_PRIVATE
);
3105 if (!PageUptodate(p
))
3110 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3112 spin_lock(&tree
->buffer_lock
);
3113 exists
= buffer_tree_insert(tree
, start
, &eb
->rb_node
);
3115 /* add one reference for the caller */
3116 atomic_inc(&exists
->refs
);
3117 spin_unlock(&tree
->buffer_lock
);
3120 spin_unlock(&tree
->buffer_lock
);
3122 /* add one reference for the tree */
3123 atomic_inc(&eb
->refs
);
3127 if (!atomic_dec_and_test(&eb
->refs
))
3129 for (index
= 1; index
< i
; index
++)
3130 page_cache_release(extent_buffer_page(eb
, index
));
3131 page_cache_release(extent_buffer_page(eb
, 0));
3132 __free_extent_buffer(eb
);
3136 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
3137 u64 start
, unsigned long len
,
3140 struct extent_buffer
*eb
;
3142 spin_lock(&tree
->buffer_lock
);
3143 eb
= buffer_search(tree
, start
);
3145 atomic_inc(&eb
->refs
);
3146 spin_unlock(&tree
->buffer_lock
);
3149 mark_page_accessed(eb
->first_page
);
3154 void free_extent_buffer(struct extent_buffer
*eb
)
3159 if (!atomic_dec_and_test(&eb
->refs
))
3165 int clear_extent_buffer_dirty(struct extent_io_tree
*tree
,
3166 struct extent_buffer
*eb
)
3169 unsigned long num_pages
;
3172 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3174 for (i
= 0; i
< num_pages
; i
++) {
3175 page
= extent_buffer_page(eb
, i
);
3176 if (!PageDirty(page
))
3181 set_page_extent_head(page
, eb
->len
);
3183 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
3185 clear_page_dirty_for_io(page
);
3186 spin_lock_irq(&page
->mapping
->tree_lock
);
3187 if (!PageDirty(page
)) {
3188 radix_tree_tag_clear(&page
->mapping
->page_tree
,
3190 PAGECACHE_TAG_DIRTY
);
3192 spin_unlock_irq(&page
->mapping
->tree_lock
);
3198 int wait_on_extent_buffer_writeback(struct extent_io_tree
*tree
,
3199 struct extent_buffer
*eb
)
3201 return wait_on_extent_writeback(tree
, eb
->start
,
3202 eb
->start
+ eb
->len
- 1);
3205 int set_extent_buffer_dirty(struct extent_io_tree
*tree
,
3206 struct extent_buffer
*eb
)
3209 unsigned long num_pages
;
3212 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
3213 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3214 for (i
= 0; i
< num_pages
; i
++)
3215 __set_page_dirty_nobuffers(extent_buffer_page(eb
, i
));
3219 int clear_extent_buffer_uptodate(struct extent_io_tree
*tree
,
3220 struct extent_buffer
*eb
)
3224 unsigned long num_pages
;
3226 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3227 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3229 clear_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3231 for (i
= 0; i
< num_pages
; i
++) {
3232 page
= extent_buffer_page(eb
, i
);
3234 ClearPageUptodate(page
);
3239 int set_extent_buffer_uptodate(struct extent_io_tree
*tree
,
3240 struct extent_buffer
*eb
)
3244 unsigned long num_pages
;
3246 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3248 set_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3250 for (i
= 0; i
< num_pages
; i
++) {
3251 page
= extent_buffer_page(eb
, i
);
3252 if ((i
== 0 && (eb
->start
& (PAGE_CACHE_SIZE
- 1))) ||
3253 ((i
== num_pages
- 1) &&
3254 ((eb
->start
+ eb
->len
) & (PAGE_CACHE_SIZE
- 1)))) {
3255 check_page_uptodate(tree
, page
);
3258 SetPageUptodate(page
);
3263 int extent_range_uptodate(struct extent_io_tree
*tree
,
3268 int pg_uptodate
= 1;
3270 unsigned long index
;
3272 ret
= test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
);
3275 while (start
<= end
) {
3276 index
= start
>> PAGE_CACHE_SHIFT
;
3277 page
= find_get_page(tree
->mapping
, index
);
3278 uptodate
= PageUptodate(page
);
3279 page_cache_release(page
);
3284 start
+= PAGE_CACHE_SIZE
;
3289 int extent_buffer_uptodate(struct extent_io_tree
*tree
,
3290 struct extent_buffer
*eb
)
3293 unsigned long num_pages
;
3296 int pg_uptodate
= 1;
3298 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
3301 ret
= test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3302 EXTENT_UPTODATE
, 1, NULL
);
3306 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3307 for (i
= 0; i
< num_pages
; i
++) {
3308 page
= extent_buffer_page(eb
, i
);
3309 if (!PageUptodate(page
)) {
3317 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
3318 struct extent_buffer
*eb
,
3319 u64 start
, int wait
,
3320 get_extent_t
*get_extent
, int mirror_num
)
3323 unsigned long start_i
;
3327 int locked_pages
= 0;
3328 int all_uptodate
= 1;
3329 int inc_all_pages
= 0;
3330 unsigned long num_pages
;
3331 struct bio
*bio
= NULL
;
3332 unsigned long bio_flags
= 0;
3334 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
3337 if (test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3338 EXTENT_UPTODATE
, 1, NULL
)) {
3343 WARN_ON(start
< eb
->start
);
3344 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
3345 (eb
->start
>> PAGE_CACHE_SHIFT
);
3350 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3351 for (i
= start_i
; i
< num_pages
; i
++) {
3352 page
= extent_buffer_page(eb
, i
);
3354 if (!trylock_page(page
))
3360 if (!PageUptodate(page
))
3365 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3369 for (i
= start_i
; i
< num_pages
; i
++) {
3370 page
= extent_buffer_page(eb
, i
);
3372 page_cache_get(page
);
3373 if (!PageUptodate(page
)) {
3376 ClearPageError(page
);
3377 err
= __extent_read_full_page(tree
, page
,
3379 mirror_num
, &bio_flags
);
3388 submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3393 for (i
= start_i
; i
< num_pages
; i
++) {
3394 page
= extent_buffer_page(eb
, i
);
3395 wait_on_page_locked(page
);
3396 if (!PageUptodate(page
))
3401 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3406 while (locked_pages
> 0) {
3407 page
= extent_buffer_page(eb
, i
);
3415 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
3416 unsigned long start
,
3423 char *dst
= (char *)dstv
;
3424 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3425 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3427 WARN_ON(start
> eb
->len
);
3428 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3430 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3433 page
= extent_buffer_page(eb
, i
);
3435 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
3436 kaddr
= kmap_atomic(page
, KM_USER1
);
3437 memcpy(dst
, kaddr
+ offset
, cur
);
3438 kunmap_atomic(kaddr
, KM_USER1
);
3447 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
3448 unsigned long min_len
, char **token
, char **map
,
3449 unsigned long *map_start
,
3450 unsigned long *map_len
, int km
)
3452 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
3455 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3456 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3457 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
3464 offset
= start_offset
;
3468 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
3471 if (start
+ min_len
> eb
->len
) {
3472 printk(KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
3473 "wanted %lu %lu\n", (unsigned long long)eb
->start
,
3474 eb
->len
, start
, min_len
);
3478 p
= extent_buffer_page(eb
, i
);
3479 kaddr
= kmap_atomic(p
, km
);
3481 *map
= kaddr
+ offset
;
3482 *map_len
= PAGE_CACHE_SIZE
- offset
;
3486 int map_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
3487 unsigned long min_len
,
3488 char **token
, char **map
,
3489 unsigned long *map_start
,
3490 unsigned long *map_len
, int km
)
3494 if (eb
->map_token
) {
3495 unmap_extent_buffer(eb
, eb
->map_token
, km
);
3496 eb
->map_token
= NULL
;
3499 err
= map_private_extent_buffer(eb
, start
, min_len
, token
, map
,
3500 map_start
, map_len
, km
);
3502 eb
->map_token
= *token
;
3504 eb
->map_start
= *map_start
;
3505 eb
->map_len
= *map_len
;
3510 void unmap_extent_buffer(struct extent_buffer
*eb
, char *token
, int km
)
3512 kunmap_atomic(token
, km
);
3515 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
3516 unsigned long start
,
3523 char *ptr
= (char *)ptrv
;
3524 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3525 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3528 WARN_ON(start
> eb
->len
);
3529 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3531 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3534 page
= extent_buffer_page(eb
, i
);
3536 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
3538 kaddr
= kmap_atomic(page
, KM_USER0
);
3539 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
3540 kunmap_atomic(kaddr
, KM_USER0
);
3552 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
3553 unsigned long start
, unsigned long len
)
3559 char *src
= (char *)srcv
;
3560 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3561 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3563 WARN_ON(start
> eb
->len
);
3564 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3566 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3569 page
= extent_buffer_page(eb
, i
);
3570 WARN_ON(!PageUptodate(page
));
3572 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
3573 kaddr
= kmap_atomic(page
, KM_USER1
);
3574 memcpy(kaddr
+ offset
, src
, cur
);
3575 kunmap_atomic(kaddr
, KM_USER1
);
3584 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
3585 unsigned long start
, unsigned long len
)
3591 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3592 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3594 WARN_ON(start
> eb
->len
);
3595 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3597 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3600 page
= extent_buffer_page(eb
, i
);
3601 WARN_ON(!PageUptodate(page
));
3603 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
3604 kaddr
= kmap_atomic(page
, KM_USER0
);
3605 memset(kaddr
+ offset
, c
, cur
);
3606 kunmap_atomic(kaddr
, KM_USER0
);
3614 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
3615 unsigned long dst_offset
, unsigned long src_offset
,
3618 u64 dst_len
= dst
->len
;
3623 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3624 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
3626 WARN_ON(src
->len
!= dst_len
);
3628 offset
= (start_offset
+ dst_offset
) &
3629 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3632 page
= extent_buffer_page(dst
, i
);
3633 WARN_ON(!PageUptodate(page
));
3635 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
3637 kaddr
= kmap_atomic(page
, KM_USER0
);
3638 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
3639 kunmap_atomic(kaddr
, KM_USER0
);
3648 static void move_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
);
3653 if (dst_page
== src_page
) {
3654 memmove(dst_kaddr
+ dst_off
, dst_kaddr
+ src_off
, len
);
3656 char *src_kaddr
= kmap_atomic(src_page
, KM_USER1
);
3657 char *p
= dst_kaddr
+ dst_off
+ len
;
3658 char *s
= src_kaddr
+ src_off
+ len
;
3663 kunmap_atomic(src_kaddr
, KM_USER1
);
3665 kunmap_atomic(dst_kaddr
, KM_USER0
);
3668 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
3669 unsigned long dst_off
, unsigned long src_off
,
3672 char *dst_kaddr
= kmap_atomic(dst_page
, KM_USER0
);
3675 if (dst_page
!= src_page
)
3676 src_kaddr
= kmap_atomic(src_page
, KM_USER1
);
3678 src_kaddr
= dst_kaddr
;
3680 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
3681 kunmap_atomic(dst_kaddr
, KM_USER0
);
3682 if (dst_page
!= src_page
)
3683 kunmap_atomic(src_kaddr
, KM_USER1
);
3686 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
3687 unsigned long src_offset
, unsigned long len
)
3690 size_t dst_off_in_page
;
3691 size_t src_off_in_page
;
3692 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3693 unsigned long dst_i
;
3694 unsigned long src_i
;
3696 if (src_offset
+ len
> dst
->len
) {
3697 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
3698 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
3701 if (dst_offset
+ len
> dst
->len
) {
3702 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
3703 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
3708 dst_off_in_page
= (start_offset
+ dst_offset
) &
3709 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3710 src_off_in_page
= (start_offset
+ src_offset
) &
3711 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3713 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
3714 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
3716 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
3718 cur
= min_t(unsigned long, cur
,
3719 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
3721 copy_pages(extent_buffer_page(dst
, dst_i
),
3722 extent_buffer_page(dst
, src_i
),
3723 dst_off_in_page
, src_off_in_page
, cur
);
3731 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
3732 unsigned long src_offset
, unsigned long len
)
3735 size_t dst_off_in_page
;
3736 size_t src_off_in_page
;
3737 unsigned long dst_end
= dst_offset
+ len
- 1;
3738 unsigned long src_end
= src_offset
+ len
- 1;
3739 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3740 unsigned long dst_i
;
3741 unsigned long src_i
;
3743 if (src_offset
+ len
> dst
->len
) {
3744 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
3745 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
3748 if (dst_offset
+ len
> dst
->len
) {
3749 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
3750 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
3753 if (dst_offset
< src_offset
) {
3754 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
3758 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
3759 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
3761 dst_off_in_page
= (start_offset
+ dst_end
) &
3762 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3763 src_off_in_page
= (start_offset
+ src_end
) &
3764 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3766 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
3767 cur
= min(cur
, dst_off_in_page
+ 1);
3768 move_pages(extent_buffer_page(dst
, dst_i
),
3769 extent_buffer_page(dst
, src_i
),
3770 dst_off_in_page
- cur
+ 1,
3771 src_off_in_page
- cur
+ 1, cur
);
3779 int try_release_extent_buffer(struct extent_io_tree
*tree
, struct page
*page
)
3781 u64 start
= page_offset(page
);
3782 struct extent_buffer
*eb
;
3785 unsigned long num_pages
;
3787 spin_lock(&tree
->buffer_lock
);
3788 eb
= buffer_search(tree
, start
);
3792 if (atomic_read(&eb
->refs
) > 1) {
3796 if (test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3800 /* at this point we can safely release the extent buffer */
3801 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3802 for (i
= 0; i
< num_pages
; i
++)
3803 page_cache_release(extent_buffer_page(eb
, i
));
3804 rb_erase(&eb
->rb_node
, &tree
->buffer
);
3805 __free_extent_buffer(eb
);
3807 spin_unlock(&tree
->buffer_lock
);