1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/module.h>
8 #include <linux/spinlock.h>
9 #include <linux/blkdev.h>
10 #include <linux/swap.h>
11 #include <linux/writeback.h>
12 #include <linux/pagevec.h>
13 #include "extent_io.h"
14 #include "extent_map.h"
17 #include "btrfs_inode.h"
19 static struct kmem_cache
*extent_state_cache
;
20 static struct kmem_cache
*extent_buffer_cache
;
22 static LIST_HEAD(buffers
);
23 static LIST_HEAD(states
);
27 static DEFINE_SPINLOCK(leak_lock
);
30 #define BUFFER_LRU_MAX 64
35 struct rb_node rb_node
;
38 struct extent_page_data
{
40 struct extent_io_tree
*tree
;
41 get_extent_t
*get_extent
;
43 /* tells writepage not to lock the state bits for this range
44 * it still does the unlocking
46 unsigned int extent_locked
:1;
48 /* tells the submit_bio code to use a WRITE_SYNC */
49 unsigned int sync_io
:1;
52 int __init
extent_io_init(void)
54 extent_state_cache
= kmem_cache_create("extent_state",
55 sizeof(struct extent_state
), 0,
56 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
57 if (!extent_state_cache
)
60 extent_buffer_cache
= kmem_cache_create("extent_buffers",
61 sizeof(struct extent_buffer
), 0,
62 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
63 if (!extent_buffer_cache
)
64 goto free_state_cache
;
68 kmem_cache_destroy(extent_state_cache
);
72 void extent_io_exit(void)
74 struct extent_state
*state
;
75 struct extent_buffer
*eb
;
77 while (!list_empty(&states
)) {
78 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
79 printk(KERN_ERR
"btrfs state leak: start %llu end %llu "
80 "state %lu in tree %p refs %d\n",
81 (unsigned long long)state
->start
,
82 (unsigned long long)state
->end
,
83 state
->state
, state
->tree
, atomic_read(&state
->refs
));
84 list_del(&state
->leak_list
);
85 kmem_cache_free(extent_state_cache
, state
);
89 while (!list_empty(&buffers
)) {
90 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
91 printk(KERN_ERR
"btrfs buffer leak start %llu len %lu "
92 "refs %d\n", (unsigned long long)eb
->start
,
93 eb
->len
, atomic_read(&eb
->refs
));
94 list_del(&eb
->leak_list
);
95 kmem_cache_free(extent_buffer_cache
, eb
);
97 if (extent_state_cache
)
98 kmem_cache_destroy(extent_state_cache
);
99 if (extent_buffer_cache
)
100 kmem_cache_destroy(extent_buffer_cache
);
103 void extent_io_tree_init(struct extent_io_tree
*tree
,
104 struct address_space
*mapping
)
106 tree
->state
= RB_ROOT
;
107 INIT_RADIX_TREE(&tree
->buffer
, GFP_ATOMIC
);
109 tree
->dirty_bytes
= 0;
110 spin_lock_init(&tree
->lock
);
111 spin_lock_init(&tree
->buffer_lock
);
112 tree
->mapping
= mapping
;
115 static struct extent_state
*alloc_extent_state(gfp_t mask
)
117 struct extent_state
*state
;
122 state
= kmem_cache_alloc(extent_state_cache
, mask
);
129 spin_lock_irqsave(&leak_lock
, flags
);
130 list_add(&state
->leak_list
, &states
);
131 spin_unlock_irqrestore(&leak_lock
, flags
);
133 atomic_set(&state
->refs
, 1);
134 init_waitqueue_head(&state
->wq
);
138 void free_extent_state(struct extent_state
*state
)
142 if (atomic_dec_and_test(&state
->refs
)) {
146 WARN_ON(state
->tree
);
148 spin_lock_irqsave(&leak_lock
, flags
);
149 list_del(&state
->leak_list
);
150 spin_unlock_irqrestore(&leak_lock
, flags
);
152 kmem_cache_free(extent_state_cache
, state
);
156 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
157 struct rb_node
*node
)
159 struct rb_node
**p
= &root
->rb_node
;
160 struct rb_node
*parent
= NULL
;
161 struct tree_entry
*entry
;
165 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
167 if (offset
< entry
->start
)
169 else if (offset
> entry
->end
)
175 entry
= rb_entry(node
, struct tree_entry
, rb_node
);
176 rb_link_node(node
, parent
, p
);
177 rb_insert_color(node
, root
);
181 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
182 struct rb_node
**prev_ret
,
183 struct rb_node
**next_ret
)
185 struct rb_root
*root
= &tree
->state
;
186 struct rb_node
*n
= root
->rb_node
;
187 struct rb_node
*prev
= NULL
;
188 struct rb_node
*orig_prev
= NULL
;
189 struct tree_entry
*entry
;
190 struct tree_entry
*prev_entry
= NULL
;
193 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
197 if (offset
< entry
->start
)
199 else if (offset
> entry
->end
)
207 while (prev
&& offset
> prev_entry
->end
) {
208 prev
= rb_next(prev
);
209 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
216 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
217 while (prev
&& offset
< prev_entry
->start
) {
218 prev
= rb_prev(prev
);
219 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
226 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
229 struct rb_node
*prev
= NULL
;
232 ret
= __etree_search(tree
, offset
, &prev
, NULL
);
238 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
239 struct extent_state
*other
)
241 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
242 tree
->ops
->merge_extent_hook(tree
->mapping
->host
, new,
247 * utility function to look for merge candidates inside a given range.
248 * Any extents with matching state are merged together into a single
249 * extent in the tree. Extents with EXTENT_IO in their state field
250 * are not merged because the end_io handlers need to be able to do
251 * operations on them without sleeping (or doing allocations/splits).
253 * This should be called with the tree lock held.
255 static int merge_state(struct extent_io_tree
*tree
,
256 struct extent_state
*state
)
258 struct extent_state
*other
;
259 struct rb_node
*other_node
;
261 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
264 other_node
= rb_prev(&state
->rb_node
);
266 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
267 if (other
->end
== state
->start
- 1 &&
268 other
->state
== state
->state
) {
269 merge_cb(tree
, state
, other
);
270 state
->start
= other
->start
;
272 rb_erase(&other
->rb_node
, &tree
->state
);
273 free_extent_state(other
);
276 other_node
= rb_next(&state
->rb_node
);
278 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
279 if (other
->start
== state
->end
+ 1 &&
280 other
->state
== state
->state
) {
281 merge_cb(tree
, state
, other
);
282 state
->end
= other
->end
;
284 rb_erase(&other
->rb_node
, &tree
->state
);
285 free_extent_state(other
);
292 static int set_state_cb(struct extent_io_tree
*tree
,
293 struct extent_state
*state
, int *bits
)
295 if (tree
->ops
&& tree
->ops
->set_bit_hook
) {
296 return tree
->ops
->set_bit_hook(tree
->mapping
->host
,
303 static void clear_state_cb(struct extent_io_tree
*tree
,
304 struct extent_state
*state
, int *bits
)
306 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
307 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
, bits
);
311 * insert an extent_state struct into the tree. 'bits' are set on the
312 * struct before it is inserted.
314 * This may return -EEXIST if the extent is already there, in which case the
315 * state struct is freed.
317 * The tree lock is not taken internally. This is a utility function and
318 * probably isn't what you want to call (see set/clear_extent_bit).
320 static int insert_state(struct extent_io_tree
*tree
,
321 struct extent_state
*state
, u64 start
, u64 end
,
324 struct rb_node
*node
;
325 int bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
329 printk(KERN_ERR
"btrfs end < start %llu %llu\n",
330 (unsigned long long)end
,
331 (unsigned long long)start
);
334 state
->start
= start
;
336 ret
= set_state_cb(tree
, state
, bits
);
340 if (bits_to_set
& EXTENT_DIRTY
)
341 tree
->dirty_bytes
+= end
- start
+ 1;
342 state
->state
|= bits_to_set
;
343 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
345 struct extent_state
*found
;
346 found
= rb_entry(node
, struct extent_state
, rb_node
);
347 printk(KERN_ERR
"btrfs found node %llu %llu on insert of "
348 "%llu %llu\n", (unsigned long long)found
->start
,
349 (unsigned long long)found
->end
,
350 (unsigned long long)start
, (unsigned long long)end
);
354 merge_state(tree
, state
);
358 static int split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
361 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
362 return tree
->ops
->split_extent_hook(tree
->mapping
->host
,
368 * split a given extent state struct in two, inserting the preallocated
369 * struct 'prealloc' as the newly created second half. 'split' indicates an
370 * offset inside 'orig' where it should be split.
373 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
374 * are two extent state structs in the tree:
375 * prealloc: [orig->start, split - 1]
376 * orig: [ split, orig->end ]
378 * The tree locks are not taken by this function. They need to be held
381 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
382 struct extent_state
*prealloc
, u64 split
)
384 struct rb_node
*node
;
386 split_cb(tree
, orig
, split
);
388 prealloc
->start
= orig
->start
;
389 prealloc
->end
= split
- 1;
390 prealloc
->state
= orig
->state
;
393 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
395 free_extent_state(prealloc
);
398 prealloc
->tree
= tree
;
403 * utility function to clear some bits in an extent state struct.
404 * it will optionally wake up any one waiting on this state (wake == 1), or
405 * forcibly remove the state from the tree (delete == 1).
407 * If no bits are set on the state struct after clearing things, the
408 * struct is freed and removed from the tree
410 static int clear_state_bit(struct extent_io_tree
*tree
,
411 struct extent_state
*state
,
414 int bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
415 int ret
= state
->state
& bits_to_clear
;
417 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
418 u64 range
= state
->end
- state
->start
+ 1;
419 WARN_ON(range
> tree
->dirty_bytes
);
420 tree
->dirty_bytes
-= range
;
422 clear_state_cb(tree
, state
, bits
);
423 state
->state
&= ~bits_to_clear
;
426 if (state
->state
== 0) {
428 rb_erase(&state
->rb_node
, &tree
->state
);
430 free_extent_state(state
);
435 merge_state(tree
, state
);
440 static struct extent_state
*
441 alloc_extent_state_atomic(struct extent_state
*prealloc
)
444 prealloc
= alloc_extent_state(GFP_ATOMIC
);
450 * clear some bits on a range in the tree. This may require splitting
451 * or inserting elements in the tree, so the gfp mask is used to
452 * indicate which allocations or sleeping are allowed.
454 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
455 * the given range from the tree regardless of state (ie for truncate).
457 * the range [start, end] is inclusive.
459 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
460 * bits were already set, or zero if none of the bits were already set.
462 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
463 int bits
, int wake
, int delete,
464 struct extent_state
**cached_state
,
467 struct extent_state
*state
;
468 struct extent_state
*cached
;
469 struct extent_state
*prealloc
= NULL
;
470 struct rb_node
*next_node
;
471 struct rb_node
*node
;
478 bits
|= ~EXTENT_CTLBITS
;
479 bits
|= EXTENT_FIRST_DELALLOC
;
481 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
484 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
485 prealloc
= alloc_extent_state(mask
);
490 spin_lock(&tree
->lock
);
492 cached
= *cached_state
;
495 *cached_state
= NULL
;
499 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
500 cached
->end
> start
) {
502 atomic_dec(&cached
->refs
);
507 free_extent_state(cached
);
510 * this search will find the extents that end after
513 node
= tree_search(tree
, start
);
516 state
= rb_entry(node
, struct extent_state
, rb_node
);
518 if (state
->start
> end
)
520 WARN_ON(state
->end
< start
);
521 last_end
= state
->end
;
524 * | ---- desired range ---- |
526 * | ------------- state -------------- |
528 * We need to split the extent we found, and may flip
529 * bits on second half.
531 * If the extent we found extends past our range, we
532 * just split and search again. It'll get split again
533 * the next time though.
535 * If the extent we found is inside our range, we clear
536 * the desired bit on it.
539 if (state
->start
< start
) {
540 prealloc
= alloc_extent_state_atomic(prealloc
);
542 err
= split_state(tree
, state
, prealloc
, start
);
543 BUG_ON(err
== -EEXIST
);
547 if (state
->end
<= end
) {
548 set
|= clear_state_bit(tree
, state
, &bits
, wake
);
549 if (last_end
== (u64
)-1)
551 start
= last_end
+ 1;
556 * | ---- desired range ---- |
558 * We need to split the extent, and clear the bit
561 if (state
->start
<= end
&& state
->end
> end
) {
562 prealloc
= alloc_extent_state_atomic(prealloc
);
564 err
= split_state(tree
, state
, prealloc
, end
+ 1);
565 BUG_ON(err
== -EEXIST
);
569 set
|= clear_state_bit(tree
, prealloc
, &bits
, wake
);
575 if (state
->end
< end
&& prealloc
&& !need_resched())
576 next_node
= rb_next(&state
->rb_node
);
580 set
|= clear_state_bit(tree
, state
, &bits
, wake
);
581 if (last_end
== (u64
)-1)
583 start
= last_end
+ 1;
584 if (start
<= end
&& next_node
) {
585 state
= rb_entry(next_node
, struct extent_state
,
587 if (state
->start
== start
)
593 spin_unlock(&tree
->lock
);
595 free_extent_state(prealloc
);
602 spin_unlock(&tree
->lock
);
603 if (mask
& __GFP_WAIT
)
608 static int wait_on_state(struct extent_io_tree
*tree
,
609 struct extent_state
*state
)
610 __releases(tree
->lock
)
611 __acquires(tree
->lock
)
614 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
615 spin_unlock(&tree
->lock
);
617 spin_lock(&tree
->lock
);
618 finish_wait(&state
->wq
, &wait
);
623 * waits for one or more bits to clear on a range in the state tree.
624 * The range [start, end] is inclusive.
625 * The tree lock is taken by this function
627 int wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
, int bits
)
629 struct extent_state
*state
;
630 struct rb_node
*node
;
632 spin_lock(&tree
->lock
);
636 * this search will find all the extents that end after
639 node
= tree_search(tree
, start
);
643 state
= rb_entry(node
, struct extent_state
, rb_node
);
645 if (state
->start
> end
)
648 if (state
->state
& bits
) {
649 start
= state
->start
;
650 atomic_inc(&state
->refs
);
651 wait_on_state(tree
, state
);
652 free_extent_state(state
);
655 start
= state
->end
+ 1;
660 if (need_resched()) {
661 spin_unlock(&tree
->lock
);
663 spin_lock(&tree
->lock
);
667 spin_unlock(&tree
->lock
);
671 static int set_state_bits(struct extent_io_tree
*tree
,
672 struct extent_state
*state
,
676 int bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
678 ret
= set_state_cb(tree
, state
, bits
);
681 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
682 u64 range
= state
->end
- state
->start
+ 1;
683 tree
->dirty_bytes
+= range
;
685 state
->state
|= bits_to_set
;
690 static void cache_state(struct extent_state
*state
,
691 struct extent_state
**cached_ptr
)
693 if (cached_ptr
&& !(*cached_ptr
)) {
694 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
)) {
696 atomic_inc(&state
->refs
);
701 static void uncache_state(struct extent_state
**cached_ptr
)
703 if (cached_ptr
&& (*cached_ptr
)) {
704 struct extent_state
*state
= *cached_ptr
;
706 free_extent_state(state
);
711 * set some bits on a range in the tree. This may require allocations or
712 * sleeping, so the gfp mask is used to indicate what is allowed.
714 * If any of the exclusive bits are set, this will fail with -EEXIST if some
715 * part of the range already has the desired bits set. The start of the
716 * existing range is returned in failed_start in this case.
718 * [start, end] is inclusive This takes the tree lock.
721 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
722 int bits
, int exclusive_bits
, u64
*failed_start
,
723 struct extent_state
**cached_state
, gfp_t mask
)
725 struct extent_state
*state
;
726 struct extent_state
*prealloc
= NULL
;
727 struct rb_node
*node
;
732 bits
|= EXTENT_FIRST_DELALLOC
;
734 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
735 prealloc
= alloc_extent_state(mask
);
739 spin_lock(&tree
->lock
);
740 if (cached_state
&& *cached_state
) {
741 state
= *cached_state
;
742 if (state
->start
<= start
&& state
->end
> start
&&
744 node
= &state
->rb_node
;
749 * this search will find all the extents that end after
752 node
= tree_search(tree
, start
);
754 prealloc
= alloc_extent_state_atomic(prealloc
);
756 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
758 BUG_ON(err
== -EEXIST
);
761 state
= rb_entry(node
, struct extent_state
, rb_node
);
763 last_start
= state
->start
;
764 last_end
= state
->end
;
767 * | ---- desired range ---- |
770 * Just lock what we found and keep going
772 if (state
->start
== start
&& state
->end
<= end
) {
773 struct rb_node
*next_node
;
774 if (state
->state
& exclusive_bits
) {
775 *failed_start
= state
->start
;
780 err
= set_state_bits(tree
, state
, &bits
);
784 cache_state(state
, cached_state
);
785 merge_state(tree
, state
);
786 if (last_end
== (u64
)-1)
789 start
= last_end
+ 1;
790 next_node
= rb_next(&state
->rb_node
);
791 if (next_node
&& start
< end
&& prealloc
&& !need_resched()) {
792 state
= rb_entry(next_node
, struct extent_state
,
794 if (state
->start
== start
)
801 * | ---- desired range ---- |
804 * | ------------- state -------------- |
806 * We need to split the extent we found, and may flip bits on
809 * If the extent we found extends past our
810 * range, we just split and search again. It'll get split
811 * again the next time though.
813 * If the extent we found is inside our range, we set the
816 if (state
->start
< start
) {
817 if (state
->state
& exclusive_bits
) {
818 *failed_start
= start
;
823 prealloc
= alloc_extent_state_atomic(prealloc
);
825 err
= split_state(tree
, state
, prealloc
, start
);
826 BUG_ON(err
== -EEXIST
);
830 if (state
->end
<= end
) {
831 err
= set_state_bits(tree
, state
, &bits
);
834 cache_state(state
, cached_state
);
835 merge_state(tree
, state
);
836 if (last_end
== (u64
)-1)
838 start
= last_end
+ 1;
843 * | ---- desired range ---- |
844 * | state | or | state |
846 * There's a hole, we need to insert something in it and
847 * ignore the extent we found.
849 if (state
->start
> start
) {
851 if (end
< last_start
)
854 this_end
= last_start
- 1;
856 prealloc
= alloc_extent_state_atomic(prealloc
);
860 * Avoid to free 'prealloc' if it can be merged with
863 err
= insert_state(tree
, prealloc
, start
, this_end
,
865 BUG_ON(err
== -EEXIST
);
867 free_extent_state(prealloc
);
871 cache_state(prealloc
, cached_state
);
873 start
= this_end
+ 1;
877 * | ---- desired range ---- |
879 * We need to split the extent, and set the bit
882 if (state
->start
<= end
&& state
->end
> end
) {
883 if (state
->state
& exclusive_bits
) {
884 *failed_start
= start
;
889 prealloc
= alloc_extent_state_atomic(prealloc
);
891 err
= split_state(tree
, state
, prealloc
, end
+ 1);
892 BUG_ON(err
== -EEXIST
);
894 err
= set_state_bits(tree
, prealloc
, &bits
);
899 cache_state(prealloc
, cached_state
);
900 merge_state(tree
, prealloc
);
908 spin_unlock(&tree
->lock
);
910 free_extent_state(prealloc
);
917 spin_unlock(&tree
->lock
);
918 if (mask
& __GFP_WAIT
)
923 /* wrappers around set/clear extent bit */
924 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
927 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, 0, NULL
,
931 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
932 int bits
, gfp_t mask
)
934 return set_extent_bit(tree
, start
, end
, bits
, 0, NULL
,
938 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
939 int bits
, gfp_t mask
)
941 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, mask
);
944 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
945 struct extent_state
**cached_state
, gfp_t mask
)
947 return set_extent_bit(tree
, start
, end
,
948 EXTENT_DELALLOC
| EXTENT_DIRTY
| EXTENT_UPTODATE
,
949 0, NULL
, cached_state
, mask
);
952 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
955 return clear_extent_bit(tree
, start
, end
,
956 EXTENT_DIRTY
| EXTENT_DELALLOC
|
957 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
, mask
);
960 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
963 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, NULL
,
967 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
968 struct extent_state
**cached_state
, gfp_t mask
)
970 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0,
971 NULL
, cached_state
, mask
);
974 static int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
,
975 u64 end
, struct extent_state
**cached_state
,
978 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0,
983 * either insert or lock state struct between start and end use mask to tell
984 * us if waiting is desired.
986 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
987 int bits
, struct extent_state
**cached_state
, gfp_t mask
)
992 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
993 EXTENT_LOCKED
, &failed_start
,
995 if (err
== -EEXIST
&& (mask
& __GFP_WAIT
)) {
996 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
997 start
= failed_start
;
1001 WARN_ON(start
> end
);
1006 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
, gfp_t mask
)
1008 return lock_extent_bits(tree
, start
, end
, 0, NULL
, mask
);
1011 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1017 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1018 &failed_start
, NULL
, mask
);
1019 if (err
== -EEXIST
) {
1020 if (failed_start
> start
)
1021 clear_extent_bit(tree
, start
, failed_start
- 1,
1022 EXTENT_LOCKED
, 1, 0, NULL
, mask
);
1028 int unlock_extent_cached(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1029 struct extent_state
**cached
, gfp_t mask
)
1031 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, cached
,
1035 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
, gfp_t mask
)
1037 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, NULL
,
1042 * helper function to set both pages and extents in the tree writeback
1044 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1046 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1047 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1050 while (index
<= end_index
) {
1051 page
= find_get_page(tree
->mapping
, index
);
1053 set_page_writeback(page
);
1054 page_cache_release(page
);
1061 * find the first offset in the io tree with 'bits' set. zero is
1062 * returned if we find something, and *start_ret and *end_ret are
1063 * set to reflect the state struct that was found.
1065 * If nothing was found, 1 is returned, < 0 on error
1067 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1068 u64
*start_ret
, u64
*end_ret
, int bits
)
1070 struct rb_node
*node
;
1071 struct extent_state
*state
;
1074 spin_lock(&tree
->lock
);
1076 * this search will find all the extents that end after
1079 node
= tree_search(tree
, start
);
1084 state
= rb_entry(node
, struct extent_state
, rb_node
);
1085 if (state
->end
>= start
&& (state
->state
& bits
)) {
1086 *start_ret
= state
->start
;
1087 *end_ret
= state
->end
;
1091 node
= rb_next(node
);
1096 spin_unlock(&tree
->lock
);
1100 /* find the first state struct with 'bits' set after 'start', and
1101 * return it. tree->lock must be held. NULL will returned if
1102 * nothing was found after 'start'
1104 struct extent_state
*find_first_extent_bit_state(struct extent_io_tree
*tree
,
1105 u64 start
, int bits
)
1107 struct rb_node
*node
;
1108 struct extent_state
*state
;
1111 * this search will find all the extents that end after
1114 node
= tree_search(tree
, start
);
1119 state
= rb_entry(node
, struct extent_state
, rb_node
);
1120 if (state
->end
>= start
&& (state
->state
& bits
))
1123 node
= rb_next(node
);
1132 * find a contiguous range of bytes in the file marked as delalloc, not
1133 * more than 'max_bytes'. start and end are used to return the range,
1135 * 1 is returned if we find something, 0 if nothing was in the tree
1137 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1138 u64
*start
, u64
*end
, u64 max_bytes
,
1139 struct extent_state
**cached_state
)
1141 struct rb_node
*node
;
1142 struct extent_state
*state
;
1143 u64 cur_start
= *start
;
1145 u64 total_bytes
= 0;
1147 spin_lock(&tree
->lock
);
1150 * this search will find all the extents that end after
1153 node
= tree_search(tree
, cur_start
);
1161 state
= rb_entry(node
, struct extent_state
, rb_node
);
1162 if (found
&& (state
->start
!= cur_start
||
1163 (state
->state
& EXTENT_BOUNDARY
))) {
1166 if (!(state
->state
& EXTENT_DELALLOC
)) {
1172 *start
= state
->start
;
1173 *cached_state
= state
;
1174 atomic_inc(&state
->refs
);
1178 cur_start
= state
->end
+ 1;
1179 node
= rb_next(node
);
1182 total_bytes
+= state
->end
- state
->start
+ 1;
1183 if (total_bytes
>= max_bytes
)
1187 spin_unlock(&tree
->lock
);
1191 static noinline
int __unlock_for_delalloc(struct inode
*inode
,
1192 struct page
*locked_page
,
1196 struct page
*pages
[16];
1197 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1198 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1199 unsigned long nr_pages
= end_index
- index
+ 1;
1202 if (index
== locked_page
->index
&& end_index
== index
)
1205 while (nr_pages
> 0) {
1206 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1207 min_t(unsigned long, nr_pages
,
1208 ARRAY_SIZE(pages
)), pages
);
1209 for (i
= 0; i
< ret
; i
++) {
1210 if (pages
[i
] != locked_page
)
1211 unlock_page(pages
[i
]);
1212 page_cache_release(pages
[i
]);
1221 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1222 struct page
*locked_page
,
1226 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1227 unsigned long start_index
= index
;
1228 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1229 unsigned long pages_locked
= 0;
1230 struct page
*pages
[16];
1231 unsigned long nrpages
;
1235 /* the caller is responsible for locking the start index */
1236 if (index
== locked_page
->index
&& index
== end_index
)
1239 /* skip the page at the start index */
1240 nrpages
= end_index
- index
+ 1;
1241 while (nrpages
> 0) {
1242 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1243 min_t(unsigned long,
1244 nrpages
, ARRAY_SIZE(pages
)), pages
);
1249 /* now we have an array of pages, lock them all */
1250 for (i
= 0; i
< ret
; i
++) {
1252 * the caller is taking responsibility for
1255 if (pages
[i
] != locked_page
) {
1256 lock_page(pages
[i
]);
1257 if (!PageDirty(pages
[i
]) ||
1258 pages
[i
]->mapping
!= inode
->i_mapping
) {
1260 unlock_page(pages
[i
]);
1261 page_cache_release(pages
[i
]);
1265 page_cache_release(pages
[i
]);
1274 if (ret
&& pages_locked
) {
1275 __unlock_for_delalloc(inode
, locked_page
,
1277 ((u64
)(start_index
+ pages_locked
- 1)) <<
1284 * find a contiguous range of bytes in the file marked as delalloc, not
1285 * more than 'max_bytes'. start and end are used to return the range,
1287 * 1 is returned if we find something, 0 if nothing was in the tree
1289 static noinline u64
find_lock_delalloc_range(struct inode
*inode
,
1290 struct extent_io_tree
*tree
,
1291 struct page
*locked_page
,
1292 u64
*start
, u64
*end
,
1298 struct extent_state
*cached_state
= NULL
;
1303 /* step one, find a bunch of delalloc bytes starting at start */
1304 delalloc_start
= *start
;
1306 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1307 max_bytes
, &cached_state
);
1308 if (!found
|| delalloc_end
<= *start
) {
1309 *start
= delalloc_start
;
1310 *end
= delalloc_end
;
1311 free_extent_state(cached_state
);
1316 * start comes from the offset of locked_page. We have to lock
1317 * pages in order, so we can't process delalloc bytes before
1320 if (delalloc_start
< *start
)
1321 delalloc_start
= *start
;
1324 * make sure to limit the number of pages we try to lock down
1327 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
&& loops
)
1328 delalloc_end
= delalloc_start
+ PAGE_CACHE_SIZE
- 1;
1330 /* step two, lock all the pages after the page that has start */
1331 ret
= lock_delalloc_pages(inode
, locked_page
,
1332 delalloc_start
, delalloc_end
);
1333 if (ret
== -EAGAIN
) {
1334 /* some of the pages are gone, lets avoid looping by
1335 * shortening the size of the delalloc range we're searching
1337 free_extent_state(cached_state
);
1339 unsigned long offset
= (*start
) & (PAGE_CACHE_SIZE
- 1);
1340 max_bytes
= PAGE_CACHE_SIZE
- offset
;
1350 /* step three, lock the state bits for the whole range */
1351 lock_extent_bits(tree
, delalloc_start
, delalloc_end
,
1352 0, &cached_state
, GFP_NOFS
);
1354 /* then test to make sure it is all still delalloc */
1355 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1356 EXTENT_DELALLOC
, 1, cached_state
);
1358 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1359 &cached_state
, GFP_NOFS
);
1360 __unlock_for_delalloc(inode
, locked_page
,
1361 delalloc_start
, delalloc_end
);
1365 free_extent_state(cached_state
);
1366 *start
= delalloc_start
;
1367 *end
= delalloc_end
;
1372 int extent_clear_unlock_delalloc(struct inode
*inode
,
1373 struct extent_io_tree
*tree
,
1374 u64 start
, u64 end
, struct page
*locked_page
,
1378 struct page
*pages
[16];
1379 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1380 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1381 unsigned long nr_pages
= end_index
- index
+ 1;
1385 if (op
& EXTENT_CLEAR_UNLOCK
)
1386 clear_bits
|= EXTENT_LOCKED
;
1387 if (op
& EXTENT_CLEAR_DIRTY
)
1388 clear_bits
|= EXTENT_DIRTY
;
1390 if (op
& EXTENT_CLEAR_DELALLOC
)
1391 clear_bits
|= EXTENT_DELALLOC
;
1393 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, NULL
, GFP_NOFS
);
1394 if (!(op
& (EXTENT_CLEAR_UNLOCK_PAGE
| EXTENT_CLEAR_DIRTY
|
1395 EXTENT_SET_WRITEBACK
| EXTENT_END_WRITEBACK
|
1396 EXTENT_SET_PRIVATE2
)))
1399 while (nr_pages
> 0) {
1400 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1401 min_t(unsigned long,
1402 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1403 for (i
= 0; i
< ret
; i
++) {
1405 if (op
& EXTENT_SET_PRIVATE2
)
1406 SetPagePrivate2(pages
[i
]);
1408 if (pages
[i
] == locked_page
) {
1409 page_cache_release(pages
[i
]);
1412 if (op
& EXTENT_CLEAR_DIRTY
)
1413 clear_page_dirty_for_io(pages
[i
]);
1414 if (op
& EXTENT_SET_WRITEBACK
)
1415 set_page_writeback(pages
[i
]);
1416 if (op
& EXTENT_END_WRITEBACK
)
1417 end_page_writeback(pages
[i
]);
1418 if (op
& EXTENT_CLEAR_UNLOCK_PAGE
)
1419 unlock_page(pages
[i
]);
1420 page_cache_release(pages
[i
]);
1430 * count the number of bytes in the tree that have a given bit(s)
1431 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1432 * cached. The total number found is returned.
1434 u64
count_range_bits(struct extent_io_tree
*tree
,
1435 u64
*start
, u64 search_end
, u64 max_bytes
,
1436 unsigned long bits
, int contig
)
1438 struct rb_node
*node
;
1439 struct extent_state
*state
;
1440 u64 cur_start
= *start
;
1441 u64 total_bytes
= 0;
1445 if (search_end
<= cur_start
) {
1450 spin_lock(&tree
->lock
);
1451 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1452 total_bytes
= tree
->dirty_bytes
;
1456 * this search will find all the extents that end after
1459 node
= tree_search(tree
, cur_start
);
1464 state
= rb_entry(node
, struct extent_state
, rb_node
);
1465 if (state
->start
> search_end
)
1467 if (contig
&& found
&& state
->start
> last
+ 1)
1469 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1470 total_bytes
+= min(search_end
, state
->end
) + 1 -
1471 max(cur_start
, state
->start
);
1472 if (total_bytes
>= max_bytes
)
1475 *start
= max(cur_start
, state
->start
);
1479 } else if (contig
&& found
) {
1482 node
= rb_next(node
);
1487 spin_unlock(&tree
->lock
);
1492 * set the private field for a given byte offset in the tree. If there isn't
1493 * an extent_state there already, this does nothing.
1495 int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1497 struct rb_node
*node
;
1498 struct extent_state
*state
;
1501 spin_lock(&tree
->lock
);
1503 * this search will find all the extents that end after
1506 node
= tree_search(tree
, start
);
1511 state
= rb_entry(node
, struct extent_state
, rb_node
);
1512 if (state
->start
!= start
) {
1516 state
->private = private;
1518 spin_unlock(&tree
->lock
);
1522 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1524 struct rb_node
*node
;
1525 struct extent_state
*state
;
1528 spin_lock(&tree
->lock
);
1530 * this search will find all the extents that end after
1533 node
= tree_search(tree
, start
);
1538 state
= rb_entry(node
, struct extent_state
, rb_node
);
1539 if (state
->start
!= start
) {
1543 *private = state
->private;
1545 spin_unlock(&tree
->lock
);
1550 * searches a range in the state tree for a given mask.
1551 * If 'filled' == 1, this returns 1 only if every extent in the tree
1552 * has the bits set. Otherwise, 1 is returned if any bit in the
1553 * range is found set.
1555 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1556 int bits
, int filled
, struct extent_state
*cached
)
1558 struct extent_state
*state
= NULL
;
1559 struct rb_node
*node
;
1562 spin_lock(&tree
->lock
);
1563 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
1564 cached
->end
> start
)
1565 node
= &cached
->rb_node
;
1567 node
= tree_search(tree
, start
);
1568 while (node
&& start
<= end
) {
1569 state
= rb_entry(node
, struct extent_state
, rb_node
);
1571 if (filled
&& state
->start
> start
) {
1576 if (state
->start
> end
)
1579 if (state
->state
& bits
) {
1583 } else if (filled
) {
1588 if (state
->end
== (u64
)-1)
1591 start
= state
->end
+ 1;
1594 node
= rb_next(node
);
1601 spin_unlock(&tree
->lock
);
1606 * helper function to set a given page up to date if all the
1607 * extents in the tree for that page are up to date
1609 static int check_page_uptodate(struct extent_io_tree
*tree
,
1612 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1613 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1614 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1615 SetPageUptodate(page
);
1620 * helper function to unlock a page if all the extents in the tree
1621 * for that page are unlocked
1623 static int check_page_locked(struct extent_io_tree
*tree
,
1626 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1627 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1628 if (!test_range_bit(tree
, start
, end
, EXTENT_LOCKED
, 0, NULL
))
1634 * helper function to end page writeback if all the extents
1635 * in the tree for that page are done with writeback
1637 static int check_page_writeback(struct extent_io_tree
*tree
,
1640 end_page_writeback(page
);
1644 /* lots and lots of room for performance fixes in the end_bio funcs */
1647 * after a writepage IO is done, we need to:
1648 * clear the uptodate bits on error
1649 * clear the writeback bits in the extent tree for this IO
1650 * end_page_writeback if the page has no more pending IO
1652 * Scheduling is not allowed, so the extent state tree is expected
1653 * to have one and only one object corresponding to this IO.
1655 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
1657 int uptodate
= err
== 0;
1658 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1659 struct extent_io_tree
*tree
;
1666 struct page
*page
= bvec
->bv_page
;
1667 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1669 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1671 end
= start
+ bvec
->bv_len
- 1;
1673 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1678 if (--bvec
>= bio
->bi_io_vec
)
1679 prefetchw(&bvec
->bv_page
->flags
);
1680 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
1681 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
1682 end
, NULL
, uptodate
);
1687 if (!uptodate
&& tree
->ops
&&
1688 tree
->ops
->writepage_io_failed_hook
) {
1689 ret
= tree
->ops
->writepage_io_failed_hook(bio
, page
,
1692 uptodate
= (err
== 0);
1698 clear_extent_uptodate(tree
, start
, end
, NULL
, GFP_NOFS
);
1699 ClearPageUptodate(page
);
1704 end_page_writeback(page
);
1706 check_page_writeback(tree
, page
);
1707 } while (bvec
>= bio
->bi_io_vec
);
1713 * after a readpage IO is done, we need to:
1714 * clear the uptodate bits on error
1715 * set the uptodate bits if things worked
1716 * set the page up to date if all extents in the tree are uptodate
1717 * clear the lock bit in the extent tree
1718 * unlock the page if there are no other extents locked for it
1720 * Scheduling is not allowed, so the extent state tree is expected
1721 * to have one and only one object corresponding to this IO.
1723 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
1725 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1726 struct bio_vec
*bvec_end
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1727 struct bio_vec
*bvec
= bio
->bi_io_vec
;
1728 struct extent_io_tree
*tree
;
1738 struct page
*page
= bvec
->bv_page
;
1739 struct extent_state
*cached
= NULL
;
1740 struct extent_state
*state
;
1742 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
1744 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
1746 end
= start
+ bvec
->bv_len
- 1;
1748 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
1753 if (++bvec
<= bvec_end
)
1754 prefetchw(&bvec
->bv_page
->flags
);
1756 spin_lock(&tree
->lock
);
1757 state
= find_first_extent_bit_state(tree
, start
, EXTENT_LOCKED
);
1758 if (state
&& state
->start
== start
) {
1760 * take a reference on the state, unlock will drop
1763 cache_state(state
, &cached
);
1765 spin_unlock(&tree
->lock
);
1767 if (uptodate
&& tree
->ops
&& tree
->ops
->readpage_end_io_hook
) {
1768 ret
= tree
->ops
->readpage_end_io_hook(page
, start
, end
,
1773 if (!uptodate
&& tree
->ops
&&
1774 tree
->ops
->readpage_io_failed_hook
) {
1775 ret
= tree
->ops
->readpage_io_failed_hook(bio
, page
,
1779 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1782 uncache_state(&cached
);
1788 set_extent_uptodate(tree
, start
, end
, &cached
,
1791 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
1795 SetPageUptodate(page
);
1797 ClearPageUptodate(page
);
1803 check_page_uptodate(tree
, page
);
1805 ClearPageUptodate(page
);
1808 check_page_locked(tree
, page
);
1810 } while (bvec
<= bvec_end
);
1816 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
1821 bio
= bio_alloc(gfp_flags
, nr_vecs
);
1823 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
1824 while (!bio
&& (nr_vecs
/= 2))
1825 bio
= bio_alloc(gfp_flags
, nr_vecs
);
1830 bio
->bi_bdev
= bdev
;
1831 bio
->bi_sector
= first_sector
;
1836 static int submit_one_bio(int rw
, struct bio
*bio
, int mirror_num
,
1837 unsigned long bio_flags
)
1840 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1841 struct page
*page
= bvec
->bv_page
;
1842 struct extent_io_tree
*tree
= bio
->bi_private
;
1845 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) + bvec
->bv_offset
;
1847 bio
->bi_private
= NULL
;
1851 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
1852 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
1853 mirror_num
, bio_flags
, start
);
1855 submit_bio(rw
, bio
);
1856 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
1862 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
1863 struct page
*page
, sector_t sector
,
1864 size_t size
, unsigned long offset
,
1865 struct block_device
*bdev
,
1866 struct bio
**bio_ret
,
1867 unsigned long max_pages
,
1868 bio_end_io_t end_io_func
,
1870 unsigned long prev_bio_flags
,
1871 unsigned long bio_flags
)
1877 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
1878 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
1879 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
1881 if (bio_ret
&& *bio_ret
) {
1884 contig
= bio
->bi_sector
== sector
;
1886 contig
= bio
->bi_sector
+ (bio
->bi_size
>> 9) ==
1889 if (prev_bio_flags
!= bio_flags
|| !contig
||
1890 (tree
->ops
&& tree
->ops
->merge_bio_hook
&&
1891 tree
->ops
->merge_bio_hook(page
, offset
, page_size
, bio
,
1893 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
1894 ret
= submit_one_bio(rw
, bio
, mirror_num
,
1901 if (this_compressed
)
1904 nr
= bio_get_nr_vecs(bdev
);
1906 bio
= btrfs_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
1910 bio_add_page(bio
, page
, page_size
, offset
);
1911 bio
->bi_end_io
= end_io_func
;
1912 bio
->bi_private
= tree
;
1917 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
1922 void set_page_extent_mapped(struct page
*page
)
1924 if (!PagePrivate(page
)) {
1925 SetPagePrivate(page
);
1926 page_cache_get(page
);
1927 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
1931 static void set_page_extent_head(struct page
*page
, unsigned long len
)
1933 WARN_ON(!PagePrivate(page
));
1934 set_page_private(page
, EXTENT_PAGE_PRIVATE_FIRST_PAGE
| len
<< 2);
1938 * basic readpage implementation. Locked extent state structs are inserted
1939 * into the tree that are removed when the IO is done (by the end_io
1942 static int __extent_read_full_page(struct extent_io_tree
*tree
,
1944 get_extent_t
*get_extent
,
1945 struct bio
**bio
, int mirror_num
,
1946 unsigned long *bio_flags
)
1948 struct inode
*inode
= page
->mapping
->host
;
1949 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1950 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
1954 u64 last_byte
= i_size_read(inode
);
1958 struct extent_map
*em
;
1959 struct block_device
*bdev
;
1960 struct btrfs_ordered_extent
*ordered
;
1963 size_t pg_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
);
1973 lock_extent(tree
, start
, end
, GFP_NOFS
);
1974 ordered
= btrfs_lookup_ordered_extent(inode
, start
);
1977 unlock_extent(tree
, start
, end
, GFP_NOFS
);
1978 btrfs_start_ordered_extent(inode
, ordered
, 1);
1979 btrfs_put_ordered_extent(ordered
);
1982 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
1984 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
1987 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
1988 userpage
= kmap_atomic(page
, KM_USER0
);
1989 memset(userpage
+ zero_offset
, 0, iosize
);
1990 flush_dcache_page(page
);
1991 kunmap_atomic(userpage
, KM_USER0
);
1994 while (cur
<= end
) {
1995 if (cur
>= last_byte
) {
1997 struct extent_state
*cached
= NULL
;
1999 iosize
= PAGE_CACHE_SIZE
- pg_offset
;
2000 userpage
= kmap_atomic(page
, KM_USER0
);
2001 memset(userpage
+ pg_offset
, 0, iosize
);
2002 flush_dcache_page(page
);
2003 kunmap_atomic(userpage
, KM_USER0
);
2004 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2006 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2010 em
= get_extent(inode
, page
, pg_offset
, cur
,
2012 if (IS_ERR_OR_NULL(em
)) {
2014 unlock_extent(tree
, cur
, end
, GFP_NOFS
);
2017 extent_offset
= cur
- em
->start
;
2018 BUG_ON(extent_map_end(em
) <= cur
);
2021 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2022 this_bio_flag
= EXTENT_BIO_COMPRESSED
;
2023 extent_set_compress_type(&this_bio_flag
,
2027 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2028 cur_end
= min(extent_map_end(em
) - 1, end
);
2029 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
2030 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2031 disk_io_size
= em
->block_len
;
2032 sector
= em
->block_start
>> 9;
2034 sector
= (em
->block_start
+ extent_offset
) >> 9;
2035 disk_io_size
= iosize
;
2038 block_start
= em
->block_start
;
2039 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2040 block_start
= EXTENT_MAP_HOLE
;
2041 free_extent_map(em
);
2044 /* we've found a hole, just zero and go on */
2045 if (block_start
== EXTENT_MAP_HOLE
) {
2047 struct extent_state
*cached
= NULL
;
2049 userpage
= kmap_atomic(page
, KM_USER0
);
2050 memset(userpage
+ pg_offset
, 0, iosize
);
2051 flush_dcache_page(page
);
2052 kunmap_atomic(userpage
, KM_USER0
);
2054 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2056 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2059 pg_offset
+= iosize
;
2062 /* the get_extent function already copied into the page */
2063 if (test_range_bit(tree
, cur
, cur_end
,
2064 EXTENT_UPTODATE
, 1, NULL
)) {
2065 check_page_uptodate(tree
, page
);
2066 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2068 pg_offset
+= iosize
;
2071 /* we have an inline extent but it didn't get marked up
2072 * to date. Error out
2074 if (block_start
== EXTENT_MAP_INLINE
) {
2076 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2078 pg_offset
+= iosize
;
2083 if (tree
->ops
&& tree
->ops
->readpage_io_hook
) {
2084 ret
= tree
->ops
->readpage_io_hook(page
, cur
,
2088 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2090 ret
= submit_extent_page(READ
, tree
, page
,
2091 sector
, disk_io_size
, pg_offset
,
2093 end_bio_extent_readpage
, mirror_num
,
2097 *bio_flags
= this_bio_flag
;
2102 pg_offset
+= iosize
;
2105 if (!PageError(page
))
2106 SetPageUptodate(page
);
2112 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2113 get_extent_t
*get_extent
)
2115 struct bio
*bio
= NULL
;
2116 unsigned long bio_flags
= 0;
2119 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, 0,
2122 ret
= submit_one_bio(READ
, bio
, 0, bio_flags
);
2126 static noinline
void update_nr_written(struct page
*page
,
2127 struct writeback_control
*wbc
,
2128 unsigned long nr_written
)
2130 wbc
->nr_to_write
-= nr_written
;
2131 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
2132 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
2133 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
2137 * the writepage semantics are similar to regular writepage. extent
2138 * records are inserted to lock ranges in the tree, and as dirty areas
2139 * are found, they are marked writeback. Then the lock bits are removed
2140 * and the end_io handler clears the writeback ranges
2142 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
2145 struct inode
*inode
= page
->mapping
->host
;
2146 struct extent_page_data
*epd
= data
;
2147 struct extent_io_tree
*tree
= epd
->tree
;
2148 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2150 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2154 u64 last_byte
= i_size_read(inode
);
2158 struct extent_state
*cached_state
= NULL
;
2159 struct extent_map
*em
;
2160 struct block_device
*bdev
;
2163 size_t pg_offset
= 0;
2165 loff_t i_size
= i_size_read(inode
);
2166 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2172 unsigned long nr_written
= 0;
2174 if (wbc
->sync_mode
== WB_SYNC_ALL
)
2175 write_flags
= WRITE_SYNC
;
2177 write_flags
= WRITE
;
2179 trace___extent_writepage(page
, inode
, wbc
);
2181 WARN_ON(!PageLocked(page
));
2182 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
2183 if (page
->index
> end_index
||
2184 (page
->index
== end_index
&& !pg_offset
)) {
2185 page
->mapping
->a_ops
->invalidatepage(page
, 0);
2190 if (page
->index
== end_index
) {
2193 userpage
= kmap_atomic(page
, KM_USER0
);
2194 memset(userpage
+ pg_offset
, 0,
2195 PAGE_CACHE_SIZE
- pg_offset
);
2196 kunmap_atomic(userpage
, KM_USER0
);
2197 flush_dcache_page(page
);
2201 set_page_extent_mapped(page
);
2203 delalloc_start
= start
;
2206 if (!epd
->extent_locked
) {
2207 u64 delalloc_to_write
= 0;
2209 * make sure the wbc mapping index is at least updated
2212 update_nr_written(page
, wbc
, 0);
2214 while (delalloc_end
< page_end
) {
2215 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
2220 if (nr_delalloc
== 0) {
2221 delalloc_start
= delalloc_end
+ 1;
2224 tree
->ops
->fill_delalloc(inode
, page
, delalloc_start
,
2225 delalloc_end
, &page_started
,
2228 * delalloc_end is already one less than the total
2229 * length, so we don't subtract one from
2232 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
2235 delalloc_start
= delalloc_end
+ 1;
2237 if (wbc
->nr_to_write
< delalloc_to_write
) {
2240 if (delalloc_to_write
< thresh
* 2)
2241 thresh
= delalloc_to_write
;
2242 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
2246 /* did the fill delalloc function already unlock and start
2252 * we've unlocked the page, so we can't update
2253 * the mapping's writeback index, just update
2256 wbc
->nr_to_write
-= nr_written
;
2260 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
2261 ret
= tree
->ops
->writepage_start_hook(page
, start
,
2263 if (ret
== -EAGAIN
) {
2264 redirty_page_for_writepage(wbc
, page
);
2265 update_nr_written(page
, wbc
, nr_written
);
2273 * we don't want to touch the inode after unlocking the page,
2274 * so we update the mapping writeback index now
2276 update_nr_written(page
, wbc
, nr_written
+ 1);
2279 if (last_byte
<= start
) {
2280 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2281 tree
->ops
->writepage_end_io_hook(page
, start
,
2286 blocksize
= inode
->i_sb
->s_blocksize
;
2288 while (cur
<= end
) {
2289 if (cur
>= last_byte
) {
2290 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2291 tree
->ops
->writepage_end_io_hook(page
, cur
,
2295 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
2297 if (IS_ERR_OR_NULL(em
)) {
2302 extent_offset
= cur
- em
->start
;
2303 BUG_ON(extent_map_end(em
) <= cur
);
2305 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2306 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
2307 sector
= (em
->block_start
+ extent_offset
) >> 9;
2309 block_start
= em
->block_start
;
2310 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
2311 free_extent_map(em
);
2315 * compressed and inline extents are written through other
2318 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
2319 block_start
== EXTENT_MAP_INLINE
) {
2321 * end_io notification does not happen here for
2322 * compressed extents
2324 if (!compressed
&& tree
->ops
&&
2325 tree
->ops
->writepage_end_io_hook
)
2326 tree
->ops
->writepage_end_io_hook(page
, cur
,
2329 else if (compressed
) {
2330 /* we don't want to end_page_writeback on
2331 * a compressed extent. this happens
2338 pg_offset
+= iosize
;
2341 /* leave this out until we have a page_mkwrite call */
2342 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
2343 EXTENT_DIRTY
, 0, NULL
)) {
2345 pg_offset
+= iosize
;
2349 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
2350 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
2358 unsigned long max_nr
= end_index
+ 1;
2360 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
2361 if (!PageWriteback(page
)) {
2362 printk(KERN_ERR
"btrfs warning page %lu not "
2363 "writeback, cur %llu end %llu\n",
2364 page
->index
, (unsigned long long)cur
,
2365 (unsigned long long)end
);
2368 ret
= submit_extent_page(write_flags
, tree
, page
,
2369 sector
, iosize
, pg_offset
,
2370 bdev
, &epd
->bio
, max_nr
,
2371 end_bio_extent_writepage
,
2377 pg_offset
+= iosize
;
2382 /* make sure the mapping tag for page dirty gets cleared */
2383 set_page_writeback(page
);
2384 end_page_writeback(page
);
2390 /* drop our reference on any cached states */
2391 free_extent_state(cached_state
);
2396 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2397 * @mapping: address space structure to write
2398 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2399 * @writepage: function called for each page
2400 * @data: data passed to writepage function
2402 * If a page is already under I/O, write_cache_pages() skips it, even
2403 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2404 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2405 * and msync() need to guarantee that all the data which was dirty at the time
2406 * the call was made get new I/O started against them. If wbc->sync_mode is
2407 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2408 * existing IO to complete.
2410 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
2411 struct address_space
*mapping
,
2412 struct writeback_control
*wbc
,
2413 writepage_t writepage
, void *data
,
2414 void (*flush_fn
)(void *))
2418 int nr_to_write_done
= 0;
2419 struct pagevec pvec
;
2422 pgoff_t end
; /* Inclusive */
2426 pagevec_init(&pvec
, 0);
2427 if (wbc
->range_cyclic
) {
2428 index
= mapping
->writeback_index
; /* Start from prev offset */
2431 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2432 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
2435 if (wbc
->sync_mode
== WB_SYNC_ALL
)
2436 tag
= PAGECACHE_TAG_TOWRITE
;
2438 tag
= PAGECACHE_TAG_DIRTY
;
2440 if (wbc
->sync_mode
== WB_SYNC_ALL
)
2441 tag_pages_for_writeback(mapping
, index
, end
);
2442 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
2443 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
2444 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
2448 for (i
= 0; i
< nr_pages
; i
++) {
2449 struct page
*page
= pvec
.pages
[i
];
2452 * At this point we hold neither mapping->tree_lock nor
2453 * lock on the page itself: the page may be truncated or
2454 * invalidated (changing page->mapping to NULL), or even
2455 * swizzled back from swapper_space to tmpfs file
2458 if (tree
->ops
&& tree
->ops
->write_cache_pages_lock_hook
)
2459 tree
->ops
->write_cache_pages_lock_hook(page
);
2463 if (unlikely(page
->mapping
!= mapping
)) {
2468 if (!wbc
->range_cyclic
&& page
->index
> end
) {
2474 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
2475 if (PageWriteback(page
))
2477 wait_on_page_writeback(page
);
2480 if (PageWriteback(page
) ||
2481 !clear_page_dirty_for_io(page
)) {
2486 ret
= (*writepage
)(page
, wbc
, data
);
2488 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
2496 * the filesystem may choose to bump up nr_to_write.
2497 * We have to make sure to honor the new nr_to_write
2500 nr_to_write_done
= wbc
->nr_to_write
<= 0;
2502 pagevec_release(&pvec
);
2505 if (!scanned
&& !done
) {
2507 * We hit the last page and there is more work to be done: wrap
2508 * back to the start of the file
2517 static void flush_epd_write_bio(struct extent_page_data
*epd
)
2521 submit_one_bio(WRITE_SYNC
, epd
->bio
, 0, 0);
2523 submit_one_bio(WRITE
, epd
->bio
, 0, 0);
2528 static noinline
void flush_write_bio(void *data
)
2530 struct extent_page_data
*epd
= data
;
2531 flush_epd_write_bio(epd
);
2534 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2535 get_extent_t
*get_extent
,
2536 struct writeback_control
*wbc
)
2539 struct address_space
*mapping
= page
->mapping
;
2540 struct extent_page_data epd
= {
2543 .get_extent
= get_extent
,
2545 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
2547 struct writeback_control wbc_writepages
= {
2548 .sync_mode
= wbc
->sync_mode
,
2549 .older_than_this
= NULL
,
2551 .range_start
= page_offset(page
) + PAGE_CACHE_SIZE
,
2552 .range_end
= (loff_t
)-1,
2555 ret
= __extent_writepage(page
, wbc
, &epd
);
2557 extent_write_cache_pages(tree
, mapping
, &wbc_writepages
,
2558 __extent_writepage
, &epd
, flush_write_bio
);
2559 flush_epd_write_bio(&epd
);
2563 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
2564 u64 start
, u64 end
, get_extent_t
*get_extent
,
2568 struct address_space
*mapping
= inode
->i_mapping
;
2570 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
2573 struct extent_page_data epd
= {
2576 .get_extent
= get_extent
,
2578 .sync_io
= mode
== WB_SYNC_ALL
,
2580 struct writeback_control wbc_writepages
= {
2582 .older_than_this
= NULL
,
2583 .nr_to_write
= nr_pages
* 2,
2584 .range_start
= start
,
2585 .range_end
= end
+ 1,
2588 while (start
<= end
) {
2589 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
2590 if (clear_page_dirty_for_io(page
))
2591 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
2593 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2594 tree
->ops
->writepage_end_io_hook(page
, start
,
2595 start
+ PAGE_CACHE_SIZE
- 1,
2599 page_cache_release(page
);
2600 start
+= PAGE_CACHE_SIZE
;
2603 flush_epd_write_bio(&epd
);
2607 int extent_writepages(struct extent_io_tree
*tree
,
2608 struct address_space
*mapping
,
2609 get_extent_t
*get_extent
,
2610 struct writeback_control
*wbc
)
2613 struct extent_page_data epd
= {
2616 .get_extent
= get_extent
,
2618 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
2621 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
2622 __extent_writepage
, &epd
,
2624 flush_epd_write_bio(&epd
);
2628 int extent_readpages(struct extent_io_tree
*tree
,
2629 struct address_space
*mapping
,
2630 struct list_head
*pages
, unsigned nr_pages
,
2631 get_extent_t get_extent
)
2633 struct bio
*bio
= NULL
;
2635 unsigned long bio_flags
= 0;
2637 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
2638 struct page
*page
= list_entry(pages
->prev
, struct page
, lru
);
2640 prefetchw(&page
->flags
);
2641 list_del(&page
->lru
);
2642 if (!add_to_page_cache_lru(page
, mapping
,
2643 page
->index
, GFP_NOFS
)) {
2644 __extent_read_full_page(tree
, page
, get_extent
,
2645 &bio
, 0, &bio_flags
);
2647 page_cache_release(page
);
2649 BUG_ON(!list_empty(pages
));
2651 submit_one_bio(READ
, bio
, 0, bio_flags
);
2656 * basic invalidatepage code, this waits on any locked or writeback
2657 * ranges corresponding to the page, and then deletes any extent state
2658 * records from the tree
2660 int extent_invalidatepage(struct extent_io_tree
*tree
,
2661 struct page
*page
, unsigned long offset
)
2663 struct extent_state
*cached_state
= NULL
;
2664 u64 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
);
2665 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2666 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
2668 start
+= (offset
+ blocksize
- 1) & ~(blocksize
- 1);
2672 lock_extent_bits(tree
, start
, end
, 0, &cached_state
, GFP_NOFS
);
2673 wait_on_page_writeback(page
);
2674 clear_extent_bit(tree
, start
, end
,
2675 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
2676 EXTENT_DO_ACCOUNTING
,
2677 1, 1, &cached_state
, GFP_NOFS
);
2682 * a helper for releasepage, this tests for areas of the page that
2683 * are locked or under IO and drops the related state bits if it is safe
2686 int try_release_extent_state(struct extent_map_tree
*map
,
2687 struct extent_io_tree
*tree
, struct page
*page
,
2690 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2691 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2694 if (test_range_bit(tree
, start
, end
,
2695 EXTENT_IOBITS
, 0, NULL
))
2698 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
2701 * at this point we can safely clear everything except the
2702 * locked bit and the nodatasum bit
2704 ret
= clear_extent_bit(tree
, start
, end
,
2705 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
2708 /* if clear_extent_bit failed for enomem reasons,
2709 * we can't allow the release to continue.
2720 * a helper for releasepage. As long as there are no locked extents
2721 * in the range corresponding to the page, both state records and extent
2722 * map records are removed
2724 int try_release_extent_mapping(struct extent_map_tree
*map
,
2725 struct extent_io_tree
*tree
, struct page
*page
,
2728 struct extent_map
*em
;
2729 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2730 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2732 if ((mask
& __GFP_WAIT
) &&
2733 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
2735 while (start
<= end
) {
2736 len
= end
- start
+ 1;
2737 write_lock(&map
->lock
);
2738 em
= lookup_extent_mapping(map
, start
, len
);
2739 if (IS_ERR_OR_NULL(em
)) {
2740 write_unlock(&map
->lock
);
2743 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
2744 em
->start
!= start
) {
2745 write_unlock(&map
->lock
);
2746 free_extent_map(em
);
2749 if (!test_range_bit(tree
, em
->start
,
2750 extent_map_end(em
) - 1,
2751 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
2753 remove_extent_mapping(map
, em
);
2754 /* once for the rb tree */
2755 free_extent_map(em
);
2757 start
= extent_map_end(em
);
2758 write_unlock(&map
->lock
);
2761 free_extent_map(em
);
2764 return try_release_extent_state(map
, tree
, page
, mask
);
2768 * helper function for fiemap, which doesn't want to see any holes.
2769 * This maps until we find something past 'last'
2771 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
2774 get_extent_t
*get_extent
)
2776 u64 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
2777 struct extent_map
*em
;
2784 len
= last
- offset
;
2787 len
= (len
+ sectorsize
- 1) & ~(sectorsize
- 1);
2788 em
= get_extent(inode
, NULL
, 0, offset
, len
, 0);
2789 if (IS_ERR_OR_NULL(em
))
2792 /* if this isn't a hole return it */
2793 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
2794 em
->block_start
!= EXTENT_MAP_HOLE
) {
2798 /* this is a hole, advance to the next extent */
2799 offset
= extent_map_end(em
);
2800 free_extent_map(em
);
2807 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
2808 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
2812 u64 max
= start
+ len
;
2816 u64 last_for_get_extent
= 0;
2818 u64 isize
= i_size_read(inode
);
2819 struct btrfs_key found_key
;
2820 struct extent_map
*em
= NULL
;
2821 struct extent_state
*cached_state
= NULL
;
2822 struct btrfs_path
*path
;
2823 struct btrfs_file_extent_item
*item
;
2828 unsigned long emflags
;
2833 path
= btrfs_alloc_path();
2836 path
->leave_spinning
= 1;
2839 * lookup the last file extent. We're not using i_size here
2840 * because there might be preallocation past i_size
2842 ret
= btrfs_lookup_file_extent(NULL
, BTRFS_I(inode
)->root
,
2843 path
, btrfs_ino(inode
), -1, 0);
2845 btrfs_free_path(path
);
2850 item
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
2851 struct btrfs_file_extent_item
);
2852 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
2853 found_type
= btrfs_key_type(&found_key
);
2855 /* No extents, but there might be delalloc bits */
2856 if (found_key
.objectid
!= btrfs_ino(inode
) ||
2857 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
2858 /* have to trust i_size as the end */
2860 last_for_get_extent
= isize
;
2863 * remember the start of the last extent. There are a
2864 * bunch of different factors that go into the length of the
2865 * extent, so its much less complex to remember where it started
2867 last
= found_key
.offset
;
2868 last_for_get_extent
= last
+ 1;
2870 btrfs_free_path(path
);
2873 * we might have some extents allocated but more delalloc past those
2874 * extents. so, we trust isize unless the start of the last extent is
2879 last_for_get_extent
= isize
;
2882 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
, 0,
2883 &cached_state
, GFP_NOFS
);
2885 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
2895 u64 offset_in_extent
;
2897 /* break if the extent we found is outside the range */
2898 if (em
->start
>= max
|| extent_map_end(em
) < off
)
2902 * get_extent may return an extent that starts before our
2903 * requested range. We have to make sure the ranges
2904 * we return to fiemap always move forward and don't
2905 * overlap, so adjust the offsets here
2907 em_start
= max(em
->start
, off
);
2910 * record the offset from the start of the extent
2911 * for adjusting the disk offset below
2913 offset_in_extent
= em_start
- em
->start
;
2914 em_end
= extent_map_end(em
);
2915 em_len
= em_end
- em_start
;
2916 emflags
= em
->flags
;
2921 * bump off for our next call to get_extent
2923 off
= extent_map_end(em
);
2927 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
2929 flags
|= FIEMAP_EXTENT_LAST
;
2930 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
2931 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
2932 FIEMAP_EXTENT_NOT_ALIGNED
);
2933 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
2934 flags
|= (FIEMAP_EXTENT_DELALLOC
|
2935 FIEMAP_EXTENT_UNKNOWN
);
2937 disko
= em
->block_start
+ offset_in_extent
;
2939 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
2940 flags
|= FIEMAP_EXTENT_ENCODED
;
2942 free_extent_map(em
);
2944 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
2945 (last
== (u64
)-1 && isize
<= em_end
)) {
2946 flags
|= FIEMAP_EXTENT_LAST
;
2950 /* now scan forward to see if this is really the last extent. */
2951 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
2958 flags
|= FIEMAP_EXTENT_LAST
;
2961 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
2967 free_extent_map(em
);
2969 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
,
2970 &cached_state
, GFP_NOFS
);
2974 static inline struct page
*extent_buffer_page(struct extent_buffer
*eb
,
2978 struct address_space
*mapping
;
2981 return eb
->first_page
;
2982 i
+= eb
->start
>> PAGE_CACHE_SHIFT
;
2983 mapping
= eb
->first_page
->mapping
;
2988 * extent_buffer_page is only called after pinning the page
2989 * by increasing the reference count. So we know the page must
2990 * be in the radix tree.
2993 p
= radix_tree_lookup(&mapping
->page_tree
, i
);
2999 static inline unsigned long num_extent_pages(u64 start
, u64 len
)
3001 return ((start
+ len
+ PAGE_CACHE_SIZE
- 1) >> PAGE_CACHE_SHIFT
) -
3002 (start
>> PAGE_CACHE_SHIFT
);
3005 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
3010 struct extent_buffer
*eb
= NULL
;
3012 unsigned long flags
;
3015 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
3020 rwlock_init(&eb
->lock
);
3021 atomic_set(&eb
->write_locks
, 0);
3022 atomic_set(&eb
->read_locks
, 0);
3023 atomic_set(&eb
->blocking_readers
, 0);
3024 atomic_set(&eb
->blocking_writers
, 0);
3025 atomic_set(&eb
->spinning_readers
, 0);
3026 atomic_set(&eb
->spinning_writers
, 0);
3027 init_waitqueue_head(&eb
->write_lock_wq
);
3028 init_waitqueue_head(&eb
->read_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
);
3052 * Helper for releasing extent buffer page.
3054 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
,
3055 unsigned long start_idx
)
3057 unsigned long index
;
3060 if (!eb
->first_page
)
3063 index
= num_extent_pages(eb
->start
, eb
->len
);
3064 if (start_idx
>= index
)
3069 page
= extent_buffer_page(eb
, index
);
3071 page_cache_release(page
);
3072 } while (index
!= start_idx
);
3076 * Helper for releasing the extent buffer.
3078 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
3080 btrfs_release_extent_buffer_page(eb
, 0);
3081 __free_extent_buffer(eb
);
3084 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
3085 u64 start
, unsigned long len
,
3088 unsigned long num_pages
= num_extent_pages(start
, len
);
3090 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
3091 struct extent_buffer
*eb
;
3092 struct extent_buffer
*exists
= NULL
;
3094 struct address_space
*mapping
= tree
->mapping
;
3099 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
3100 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
3102 mark_page_accessed(eb
->first_page
);
3107 eb
= __alloc_extent_buffer(tree
, start
, len
, GFP_NOFS
);
3112 eb
->first_page
= page0
;
3115 page_cache_get(page0
);
3116 mark_page_accessed(page0
);
3117 set_page_extent_mapped(page0
);
3118 set_page_extent_head(page0
, len
);
3119 uptodate
= PageUptodate(page0
);
3123 for (; i
< num_pages
; i
++, index
++) {
3124 p
= find_or_create_page(mapping
, index
, GFP_NOFS
);
3129 set_page_extent_mapped(p
);
3130 mark_page_accessed(p
);
3133 set_page_extent_head(p
, len
);
3135 set_page_private(p
, EXTENT_PAGE_PRIVATE
);
3137 if (!PageUptodate(p
))
3141 * see below about how we avoid a nasty race with release page
3142 * and why we unlock later
3148 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3150 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
3154 spin_lock(&tree
->buffer_lock
);
3155 ret
= radix_tree_insert(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
, eb
);
3156 if (ret
== -EEXIST
) {
3157 exists
= radix_tree_lookup(&tree
->buffer
,
3158 start
>> PAGE_CACHE_SHIFT
);
3159 /* add one reference for the caller */
3160 atomic_inc(&exists
->refs
);
3161 spin_unlock(&tree
->buffer_lock
);
3162 radix_tree_preload_end();
3165 /* add one reference for the tree */
3166 atomic_inc(&eb
->refs
);
3167 spin_unlock(&tree
->buffer_lock
);
3168 radix_tree_preload_end();
3171 * there is a race where release page may have
3172 * tried to find this extent buffer in the radix
3173 * but failed. It will tell the VM it is safe to
3174 * reclaim the, and it will clear the page private bit.
3175 * We must make sure to set the page private bit properly
3176 * after the extent buffer is in the radix tree so
3177 * it doesn't get lost
3179 set_page_extent_mapped(eb
->first_page
);
3180 set_page_extent_head(eb
->first_page
, eb
->len
);
3182 unlock_page(eb
->first_page
);
3186 if (eb
->first_page
&& !page0
)
3187 unlock_page(eb
->first_page
);
3189 if (!atomic_dec_and_test(&eb
->refs
))
3191 btrfs_release_extent_buffer(eb
);
3195 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
3196 u64 start
, unsigned long len
)
3198 struct extent_buffer
*eb
;
3201 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
3202 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
3204 mark_page_accessed(eb
->first_page
);
3212 void free_extent_buffer(struct extent_buffer
*eb
)
3217 if (!atomic_dec_and_test(&eb
->refs
))
3223 int clear_extent_buffer_dirty(struct extent_io_tree
*tree
,
3224 struct extent_buffer
*eb
)
3227 unsigned long num_pages
;
3230 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3232 for (i
= 0; i
< num_pages
; i
++) {
3233 page
= extent_buffer_page(eb
, i
);
3234 if (!PageDirty(page
))
3238 WARN_ON(!PagePrivate(page
));
3240 set_page_extent_mapped(page
);
3242 set_page_extent_head(page
, eb
->len
);
3244 clear_page_dirty_for_io(page
);
3245 spin_lock_irq(&page
->mapping
->tree_lock
);
3246 if (!PageDirty(page
)) {
3247 radix_tree_tag_clear(&page
->mapping
->page_tree
,
3249 PAGECACHE_TAG_DIRTY
);
3251 spin_unlock_irq(&page
->mapping
->tree_lock
);
3257 int set_extent_buffer_dirty(struct extent_io_tree
*tree
,
3258 struct extent_buffer
*eb
)
3261 unsigned long num_pages
;
3264 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
3265 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3266 for (i
= 0; i
< num_pages
; i
++)
3267 __set_page_dirty_nobuffers(extent_buffer_page(eb
, i
));
3271 static int __eb_straddles_pages(u64 start
, u64 len
)
3273 if (len
< PAGE_CACHE_SIZE
)
3275 if (start
& (PAGE_CACHE_SIZE
- 1))
3277 if ((start
+ len
) & (PAGE_CACHE_SIZE
- 1))
3282 static int eb_straddles_pages(struct extent_buffer
*eb
)
3284 return __eb_straddles_pages(eb
->start
, eb
->len
);
3287 int clear_extent_buffer_uptodate(struct extent_io_tree
*tree
,
3288 struct extent_buffer
*eb
,
3289 struct extent_state
**cached_state
)
3293 unsigned long num_pages
;
3295 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3296 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3298 if (eb_straddles_pages(eb
)) {
3299 clear_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3300 cached_state
, GFP_NOFS
);
3302 for (i
= 0; i
< num_pages
; i
++) {
3303 page
= extent_buffer_page(eb
, i
);
3305 ClearPageUptodate(page
);
3310 int set_extent_buffer_uptodate(struct extent_io_tree
*tree
,
3311 struct extent_buffer
*eb
)
3315 unsigned long num_pages
;
3317 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3319 if (eb_straddles_pages(eb
)) {
3320 set_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3323 for (i
= 0; i
< num_pages
; i
++) {
3324 page
= extent_buffer_page(eb
, i
);
3325 if ((i
== 0 && (eb
->start
& (PAGE_CACHE_SIZE
- 1))) ||
3326 ((i
== num_pages
- 1) &&
3327 ((eb
->start
+ eb
->len
) & (PAGE_CACHE_SIZE
- 1)))) {
3328 check_page_uptodate(tree
, page
);
3331 SetPageUptodate(page
);
3336 int extent_range_uptodate(struct extent_io_tree
*tree
,
3341 int pg_uptodate
= 1;
3343 unsigned long index
;
3345 if (__eb_straddles_pages(start
, end
- start
+ 1)) {
3346 ret
= test_range_bit(tree
, start
, end
,
3347 EXTENT_UPTODATE
, 1, NULL
);
3351 while (start
<= end
) {
3352 index
= start
>> PAGE_CACHE_SHIFT
;
3353 page
= find_get_page(tree
->mapping
, index
);
3354 uptodate
= PageUptodate(page
);
3355 page_cache_release(page
);
3360 start
+= PAGE_CACHE_SIZE
;
3365 int extent_buffer_uptodate(struct extent_io_tree
*tree
,
3366 struct extent_buffer
*eb
,
3367 struct extent_state
*cached_state
)
3370 unsigned long num_pages
;
3373 int pg_uptodate
= 1;
3375 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
3378 if (eb_straddles_pages(eb
)) {
3379 ret
= test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3380 EXTENT_UPTODATE
, 1, cached_state
);
3385 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3386 for (i
= 0; i
< num_pages
; i
++) {
3387 page
= extent_buffer_page(eb
, i
);
3388 if (!PageUptodate(page
)) {
3396 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
3397 struct extent_buffer
*eb
,
3398 u64 start
, int wait
,
3399 get_extent_t
*get_extent
, int mirror_num
)
3402 unsigned long start_i
;
3406 int locked_pages
= 0;
3407 int all_uptodate
= 1;
3408 int inc_all_pages
= 0;
3409 unsigned long num_pages
;
3410 struct bio
*bio
= NULL
;
3411 unsigned long bio_flags
= 0;
3413 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
3416 if (eb_straddles_pages(eb
)) {
3417 if (test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3418 EXTENT_UPTODATE
, 1, NULL
)) {
3424 WARN_ON(start
< eb
->start
);
3425 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
3426 (eb
->start
>> PAGE_CACHE_SHIFT
);
3431 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3432 for (i
= start_i
; i
< num_pages
; i
++) {
3433 page
= extent_buffer_page(eb
, i
);
3435 if (!trylock_page(page
))
3441 if (!PageUptodate(page
))
3446 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3450 for (i
= start_i
; i
< num_pages
; i
++) {
3451 page
= extent_buffer_page(eb
, i
);
3453 WARN_ON(!PagePrivate(page
));
3455 set_page_extent_mapped(page
);
3457 set_page_extent_head(page
, eb
->len
);
3460 page_cache_get(page
);
3461 if (!PageUptodate(page
)) {
3464 ClearPageError(page
);
3465 err
= __extent_read_full_page(tree
, page
,
3467 mirror_num
, &bio_flags
);
3476 submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3481 for (i
= start_i
; i
< num_pages
; i
++) {
3482 page
= extent_buffer_page(eb
, i
);
3483 wait_on_page_locked(page
);
3484 if (!PageUptodate(page
))
3489 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3494 while (locked_pages
> 0) {
3495 page
= extent_buffer_page(eb
, i
);
3503 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
3504 unsigned long start
,
3511 char *dst
= (char *)dstv
;
3512 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3513 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3515 WARN_ON(start
> eb
->len
);
3516 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3518 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3521 page
= extent_buffer_page(eb
, i
);
3523 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
3524 kaddr
= page_address(page
);
3525 memcpy(dst
, kaddr
+ offset
, cur
);
3534 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
3535 unsigned long min_len
, char **map
,
3536 unsigned long *map_start
,
3537 unsigned long *map_len
)
3539 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
3542 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3543 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3544 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
3551 offset
= start_offset
;
3555 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
3558 if (start
+ min_len
> eb
->len
) {
3559 printk(KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
3560 "wanted %lu %lu\n", (unsigned long long)eb
->start
,
3561 eb
->len
, start
, min_len
);
3566 p
= extent_buffer_page(eb
, i
);
3567 kaddr
= page_address(p
);
3568 *map
= kaddr
+ offset
;
3569 *map_len
= PAGE_CACHE_SIZE
- offset
;
3573 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
3574 unsigned long start
,
3581 char *ptr
= (char *)ptrv
;
3582 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3583 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3586 WARN_ON(start
> eb
->len
);
3587 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3589 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3592 page
= extent_buffer_page(eb
, i
);
3594 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
3596 kaddr
= page_address(page
);
3597 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
3609 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
3610 unsigned long start
, unsigned long len
)
3616 char *src
= (char *)srcv
;
3617 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3618 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3620 WARN_ON(start
> eb
->len
);
3621 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3623 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3626 page
= extent_buffer_page(eb
, i
);
3627 WARN_ON(!PageUptodate(page
));
3629 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
3630 kaddr
= page_address(page
);
3631 memcpy(kaddr
+ offset
, src
, cur
);
3640 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
3641 unsigned long start
, unsigned long len
)
3647 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3648 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
3650 WARN_ON(start
> eb
->len
);
3651 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
3653 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
3656 page
= extent_buffer_page(eb
, i
);
3657 WARN_ON(!PageUptodate(page
));
3659 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
3660 kaddr
= page_address(page
);
3661 memset(kaddr
+ offset
, c
, cur
);
3669 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
3670 unsigned long dst_offset
, unsigned long src_offset
,
3673 u64 dst_len
= dst
->len
;
3678 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3679 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
3681 WARN_ON(src
->len
!= dst_len
);
3683 offset
= (start_offset
+ dst_offset
) &
3684 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3687 page
= extent_buffer_page(dst
, i
);
3688 WARN_ON(!PageUptodate(page
));
3690 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
3692 kaddr
= page_address(page
);
3693 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
3702 static void move_pages(struct page
*dst_page
, struct page
*src_page
,
3703 unsigned long dst_off
, unsigned long src_off
,
3706 char *dst_kaddr
= page_address(dst_page
);
3707 if (dst_page
== src_page
) {
3708 memmove(dst_kaddr
+ dst_off
, dst_kaddr
+ src_off
, len
);
3710 char *src_kaddr
= page_address(src_page
);
3711 char *p
= dst_kaddr
+ dst_off
+ len
;
3712 char *s
= src_kaddr
+ src_off
+ len
;
3719 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
3721 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
3722 return distance
< len
;
3725 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
3726 unsigned long dst_off
, unsigned long src_off
,
3729 char *dst_kaddr
= page_address(dst_page
);
3732 if (dst_page
!= src_page
) {
3733 src_kaddr
= page_address(src_page
);
3735 src_kaddr
= dst_kaddr
;
3736 BUG_ON(areas_overlap(src_off
, dst_off
, len
));
3739 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
3742 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
3743 unsigned long src_offset
, unsigned long len
)
3746 size_t dst_off_in_page
;
3747 size_t src_off_in_page
;
3748 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3749 unsigned long dst_i
;
3750 unsigned long src_i
;
3752 if (src_offset
+ len
> dst
->len
) {
3753 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
3754 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
3757 if (dst_offset
+ len
> dst
->len
) {
3758 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
3759 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
3764 dst_off_in_page
= (start_offset
+ dst_offset
) &
3765 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3766 src_off_in_page
= (start_offset
+ src_offset
) &
3767 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3769 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
3770 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
3772 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
3774 cur
= min_t(unsigned long, cur
,
3775 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
3777 copy_pages(extent_buffer_page(dst
, dst_i
),
3778 extent_buffer_page(dst
, src_i
),
3779 dst_off_in_page
, src_off_in_page
, cur
);
3787 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
3788 unsigned long src_offset
, unsigned long len
)
3791 size_t dst_off_in_page
;
3792 size_t src_off_in_page
;
3793 unsigned long dst_end
= dst_offset
+ len
- 1;
3794 unsigned long src_end
= src_offset
+ len
- 1;
3795 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
3796 unsigned long dst_i
;
3797 unsigned long src_i
;
3799 if (src_offset
+ len
> dst
->len
) {
3800 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
3801 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
3804 if (dst_offset
+ len
> dst
->len
) {
3805 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
3806 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
3809 if (!areas_overlap(src_offset
, dst_offset
, len
)) {
3810 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
3814 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
3815 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
3817 dst_off_in_page
= (start_offset
+ dst_end
) &
3818 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3819 src_off_in_page
= (start_offset
+ src_end
) &
3820 ((unsigned long)PAGE_CACHE_SIZE
- 1);
3822 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
3823 cur
= min(cur
, dst_off_in_page
+ 1);
3824 move_pages(extent_buffer_page(dst
, dst_i
),
3825 extent_buffer_page(dst
, src_i
),
3826 dst_off_in_page
- cur
+ 1,
3827 src_off_in_page
- cur
+ 1, cur
);
3835 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
3837 struct extent_buffer
*eb
=
3838 container_of(head
, struct extent_buffer
, rcu_head
);
3840 btrfs_release_extent_buffer(eb
);
3843 int try_release_extent_buffer(struct extent_io_tree
*tree
, struct page
*page
)
3845 u64 start
= page_offset(page
);
3846 struct extent_buffer
*eb
;
3849 spin_lock(&tree
->buffer_lock
);
3850 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
3852 spin_unlock(&tree
->buffer_lock
);
3856 if (test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3862 * set @eb->refs to 0 if it is already 1, and then release the @eb.
3865 if (atomic_cmpxchg(&eb
->refs
, 1, 0) != 1) {
3870 radix_tree_delete(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
3872 spin_unlock(&tree
->buffer_lock
);
3874 /* at this point we can safely release the extent buffer */
3875 if (atomic_read(&eb
->refs
) == 0)
3876 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);