1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/spinlock.h>
8 #include <linux/blkdev.h>
9 #include <linux/swap.h>
10 #include <linux/writeback.h>
11 #include <linux/pagevec.h>
12 #include <linux/prefetch.h>
13 #include <linux/cleancache.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
17 #include "btrfs_inode.h"
19 #include "check-integrity.h"
21 #include "rcu-string.h"
24 static struct kmem_cache
*extent_state_cache
;
25 static struct kmem_cache
*extent_buffer_cache
;
26 static struct bio_set
*btrfs_bioset
;
28 #ifdef CONFIG_BTRFS_DEBUG
29 static LIST_HEAD(buffers
);
30 static LIST_HEAD(states
);
32 static DEFINE_SPINLOCK(leak_lock
);
35 void btrfs_leak_debug_add(struct list_head
*new, struct list_head
*head
)
39 spin_lock_irqsave(&leak_lock
, flags
);
41 spin_unlock_irqrestore(&leak_lock
, flags
);
45 void btrfs_leak_debug_del(struct list_head
*entry
)
49 spin_lock_irqsave(&leak_lock
, flags
);
51 spin_unlock_irqrestore(&leak_lock
, flags
);
55 void btrfs_leak_debug_check(void)
57 struct extent_state
*state
;
58 struct extent_buffer
*eb
;
60 while (!list_empty(&states
)) {
61 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
62 printk(KERN_ERR
"btrfs state leak: start %llu end %llu "
63 "state %lu in tree %p refs %d\n",
64 state
->start
, state
->end
, state
->state
, state
->tree
,
65 atomic_read(&state
->refs
));
66 list_del(&state
->leak_list
);
67 kmem_cache_free(extent_state_cache
, state
);
70 while (!list_empty(&buffers
)) {
71 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
72 printk(KERN_ERR
"btrfs buffer leak start %llu len %lu "
74 eb
->start
, eb
->len
, atomic_read(&eb
->refs
));
75 list_del(&eb
->leak_list
);
76 kmem_cache_free(extent_buffer_cache
, eb
);
80 #define btrfs_debug_check_extent_io_range(inode, start, end) \
81 __btrfs_debug_check_extent_io_range(__func__, (inode), (start), (end))
82 static inline void __btrfs_debug_check_extent_io_range(const char *caller
,
83 struct inode
*inode
, u64 start
, u64 end
)
85 u64 isize
= i_size_read(inode
);
87 if (end
>= PAGE_SIZE
&& (end
% 2) == 0 && end
!= isize
- 1) {
88 printk_ratelimited(KERN_DEBUG
89 "btrfs: %s: ino %llu isize %llu odd range [%llu,%llu]\n",
90 caller
, btrfs_ino(inode
), isize
, start
, end
);
94 #define btrfs_leak_debug_add(new, head) do {} while (0)
95 #define btrfs_leak_debug_del(entry) do {} while (0)
96 #define btrfs_leak_debug_check() do {} while (0)
97 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
100 #define BUFFER_LRU_MAX 64
105 struct rb_node rb_node
;
108 struct extent_page_data
{
110 struct extent_io_tree
*tree
;
111 get_extent_t
*get_extent
;
112 unsigned long bio_flags
;
114 /* tells writepage not to lock the state bits for this range
115 * it still does the unlocking
117 unsigned int extent_locked
:1;
119 /* tells the submit_bio code to use a WRITE_SYNC */
120 unsigned int sync_io
:1;
123 static noinline
void flush_write_bio(void *data
);
124 static inline struct btrfs_fs_info
*
125 tree_fs_info(struct extent_io_tree
*tree
)
127 return btrfs_sb(tree
->mapping
->host
->i_sb
);
130 int __init
extent_io_init(void)
132 extent_state_cache
= kmem_cache_create("btrfs_extent_state",
133 sizeof(struct extent_state
), 0,
134 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
135 if (!extent_state_cache
)
138 extent_buffer_cache
= kmem_cache_create("btrfs_extent_buffer",
139 sizeof(struct extent_buffer
), 0,
140 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
141 if (!extent_buffer_cache
)
142 goto free_state_cache
;
144 btrfs_bioset
= bioset_create(BIO_POOL_SIZE
,
145 offsetof(struct btrfs_io_bio
, bio
));
147 goto free_buffer_cache
;
149 if (bioset_integrity_create(btrfs_bioset
, BIO_POOL_SIZE
))
155 bioset_free(btrfs_bioset
);
159 kmem_cache_destroy(extent_buffer_cache
);
160 extent_buffer_cache
= NULL
;
163 kmem_cache_destroy(extent_state_cache
);
164 extent_state_cache
= NULL
;
168 void extent_io_exit(void)
170 btrfs_leak_debug_check();
173 * Make sure all delayed rcu free are flushed before we
177 if (extent_state_cache
)
178 kmem_cache_destroy(extent_state_cache
);
179 if (extent_buffer_cache
)
180 kmem_cache_destroy(extent_buffer_cache
);
182 bioset_free(btrfs_bioset
);
185 void extent_io_tree_init(struct extent_io_tree
*tree
,
186 struct address_space
*mapping
)
188 tree
->state
= RB_ROOT
;
189 INIT_RADIX_TREE(&tree
->buffer
, GFP_ATOMIC
);
191 tree
->dirty_bytes
= 0;
192 spin_lock_init(&tree
->lock
);
193 spin_lock_init(&tree
->buffer_lock
);
194 tree
->mapping
= mapping
;
197 static struct extent_state
*alloc_extent_state(gfp_t mask
)
199 struct extent_state
*state
;
201 state
= kmem_cache_alloc(extent_state_cache
, mask
);
207 btrfs_leak_debug_add(&state
->leak_list
, &states
);
208 atomic_set(&state
->refs
, 1);
209 init_waitqueue_head(&state
->wq
);
210 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
214 void free_extent_state(struct extent_state
*state
)
218 if (atomic_dec_and_test(&state
->refs
)) {
219 WARN_ON(state
->tree
);
220 btrfs_leak_debug_del(&state
->leak_list
);
221 trace_free_extent_state(state
, _RET_IP_
);
222 kmem_cache_free(extent_state_cache
, state
);
226 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
227 struct rb_node
*node
)
229 struct rb_node
**p
= &root
->rb_node
;
230 struct rb_node
*parent
= NULL
;
231 struct tree_entry
*entry
;
235 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
237 if (offset
< entry
->start
)
239 else if (offset
> entry
->end
)
245 rb_link_node(node
, parent
, p
);
246 rb_insert_color(node
, root
);
250 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
251 struct rb_node
**prev_ret
,
252 struct rb_node
**next_ret
)
254 struct rb_root
*root
= &tree
->state
;
255 struct rb_node
*n
= root
->rb_node
;
256 struct rb_node
*prev
= NULL
;
257 struct rb_node
*orig_prev
= NULL
;
258 struct tree_entry
*entry
;
259 struct tree_entry
*prev_entry
= NULL
;
262 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
266 if (offset
< entry
->start
)
268 else if (offset
> entry
->end
)
276 while (prev
&& offset
> prev_entry
->end
) {
277 prev
= rb_next(prev
);
278 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
285 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
286 while (prev
&& offset
< prev_entry
->start
) {
287 prev
= rb_prev(prev
);
288 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
295 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
298 struct rb_node
*prev
= NULL
;
301 ret
= __etree_search(tree
, offset
, &prev
, NULL
);
307 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
308 struct extent_state
*other
)
310 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
311 tree
->ops
->merge_extent_hook(tree
->mapping
->host
, new,
316 * utility function to look for merge candidates inside a given range.
317 * Any extents with matching state are merged together into a single
318 * extent in the tree. Extents with EXTENT_IO in their state field
319 * are not merged because the end_io handlers need to be able to do
320 * operations on them without sleeping (or doing allocations/splits).
322 * This should be called with the tree lock held.
324 static void merge_state(struct extent_io_tree
*tree
,
325 struct extent_state
*state
)
327 struct extent_state
*other
;
328 struct rb_node
*other_node
;
330 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
333 other_node
= rb_prev(&state
->rb_node
);
335 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
336 if (other
->end
== state
->start
- 1 &&
337 other
->state
== state
->state
) {
338 merge_cb(tree
, state
, other
);
339 state
->start
= other
->start
;
341 rb_erase(&other
->rb_node
, &tree
->state
);
342 free_extent_state(other
);
345 other_node
= rb_next(&state
->rb_node
);
347 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
348 if (other
->start
== state
->end
+ 1 &&
349 other
->state
== state
->state
) {
350 merge_cb(tree
, state
, other
);
351 state
->end
= other
->end
;
353 rb_erase(&other
->rb_node
, &tree
->state
);
354 free_extent_state(other
);
359 static void set_state_cb(struct extent_io_tree
*tree
,
360 struct extent_state
*state
, unsigned long *bits
)
362 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
363 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
, bits
);
366 static void clear_state_cb(struct extent_io_tree
*tree
,
367 struct extent_state
*state
, unsigned long *bits
)
369 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
370 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
, bits
);
373 static void set_state_bits(struct extent_io_tree
*tree
,
374 struct extent_state
*state
, unsigned long *bits
);
377 * insert an extent_state struct into the tree. 'bits' are set on the
378 * struct before it is inserted.
380 * This may return -EEXIST if the extent is already there, in which case the
381 * state struct is freed.
383 * The tree lock is not taken internally. This is a utility function and
384 * probably isn't what you want to call (see set/clear_extent_bit).
386 static int insert_state(struct extent_io_tree
*tree
,
387 struct extent_state
*state
, u64 start
, u64 end
,
390 struct rb_node
*node
;
393 WARN(1, KERN_ERR
"btrfs end < start %llu %llu\n",
395 state
->start
= start
;
398 set_state_bits(tree
, state
, bits
);
400 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
402 struct extent_state
*found
;
403 found
= rb_entry(node
, struct extent_state
, rb_node
);
404 printk(KERN_ERR
"btrfs found node %llu %llu on insert of "
406 found
->start
, found
->end
, start
, end
);
410 merge_state(tree
, state
);
414 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
417 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
418 tree
->ops
->split_extent_hook(tree
->mapping
->host
, orig
, split
);
422 * split a given extent state struct in two, inserting the preallocated
423 * struct 'prealloc' as the newly created second half. 'split' indicates an
424 * offset inside 'orig' where it should be split.
427 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
428 * are two extent state structs in the tree:
429 * prealloc: [orig->start, split - 1]
430 * orig: [ split, orig->end ]
432 * The tree locks are not taken by this function. They need to be held
435 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
436 struct extent_state
*prealloc
, u64 split
)
438 struct rb_node
*node
;
440 split_cb(tree
, orig
, split
);
442 prealloc
->start
= orig
->start
;
443 prealloc
->end
= split
- 1;
444 prealloc
->state
= orig
->state
;
447 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
449 free_extent_state(prealloc
);
452 prealloc
->tree
= tree
;
456 static struct extent_state
*next_state(struct extent_state
*state
)
458 struct rb_node
*next
= rb_next(&state
->rb_node
);
460 return rb_entry(next
, struct extent_state
, rb_node
);
466 * utility function to clear some bits in an extent state struct.
467 * it will optionally wake up any one waiting on this state (wake == 1).
469 * If no bits are set on the state struct after clearing things, the
470 * struct is freed and removed from the tree
472 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
473 struct extent_state
*state
,
474 unsigned long *bits
, int wake
)
476 struct extent_state
*next
;
477 unsigned long bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
479 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
480 u64 range
= state
->end
- state
->start
+ 1;
481 WARN_ON(range
> tree
->dirty_bytes
);
482 tree
->dirty_bytes
-= range
;
484 clear_state_cb(tree
, state
, bits
);
485 state
->state
&= ~bits_to_clear
;
488 if (state
->state
== 0) {
489 next
= next_state(state
);
491 rb_erase(&state
->rb_node
, &tree
->state
);
493 free_extent_state(state
);
498 merge_state(tree
, state
);
499 next
= next_state(state
);
504 static struct extent_state
*
505 alloc_extent_state_atomic(struct extent_state
*prealloc
)
508 prealloc
= alloc_extent_state(GFP_ATOMIC
);
513 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
515 btrfs_panic(tree_fs_info(tree
), err
, "Locking error: "
516 "Extent tree was modified by another "
517 "thread while locked.");
521 * clear some bits on a range in the tree. This may require splitting
522 * or inserting elements in the tree, so the gfp mask is used to
523 * indicate which allocations or sleeping are allowed.
525 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
526 * the given range from the tree regardless of state (ie for truncate).
528 * the range [start, end] is inclusive.
530 * This takes the tree lock, and returns 0 on success and < 0 on error.
532 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
533 unsigned long bits
, int wake
, int delete,
534 struct extent_state
**cached_state
,
537 struct extent_state
*state
;
538 struct extent_state
*cached
;
539 struct extent_state
*prealloc
= NULL
;
540 struct rb_node
*node
;
545 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
547 if (bits
& EXTENT_DELALLOC
)
548 bits
|= EXTENT_NORESERVE
;
551 bits
|= ~EXTENT_CTLBITS
;
552 bits
|= EXTENT_FIRST_DELALLOC
;
554 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
557 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
558 prealloc
= alloc_extent_state(mask
);
563 spin_lock(&tree
->lock
);
565 cached
= *cached_state
;
568 *cached_state
= NULL
;
572 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
573 cached
->end
> start
) {
575 atomic_dec(&cached
->refs
);
580 free_extent_state(cached
);
583 * this search will find the extents that end after
586 node
= tree_search(tree
, start
);
589 state
= rb_entry(node
, struct extent_state
, rb_node
);
591 if (state
->start
> end
)
593 WARN_ON(state
->end
< start
);
594 last_end
= state
->end
;
596 /* the state doesn't have the wanted bits, go ahead */
597 if (!(state
->state
& bits
)) {
598 state
= next_state(state
);
603 * | ---- desired range ---- |
605 * | ------------- state -------------- |
607 * We need to split the extent we found, and may flip
608 * bits on second half.
610 * If the extent we found extends past our range, we
611 * just split and search again. It'll get split again
612 * the next time though.
614 * If the extent we found is inside our range, we clear
615 * the desired bit on it.
618 if (state
->start
< start
) {
619 prealloc
= alloc_extent_state_atomic(prealloc
);
621 err
= split_state(tree
, state
, prealloc
, start
);
623 extent_io_tree_panic(tree
, err
);
628 if (state
->end
<= end
) {
629 state
= clear_state_bit(tree
, state
, &bits
, wake
);
635 * | ---- desired range ---- |
637 * We need to split the extent, and clear the bit
640 if (state
->start
<= end
&& state
->end
> end
) {
641 prealloc
= alloc_extent_state_atomic(prealloc
);
643 err
= split_state(tree
, state
, prealloc
, end
+ 1);
645 extent_io_tree_panic(tree
, err
);
650 clear_state_bit(tree
, prealloc
, &bits
, wake
);
656 state
= clear_state_bit(tree
, state
, &bits
, wake
);
658 if (last_end
== (u64
)-1)
660 start
= last_end
+ 1;
661 if (start
<= end
&& state
&& !need_resched())
666 spin_unlock(&tree
->lock
);
668 free_extent_state(prealloc
);
675 spin_unlock(&tree
->lock
);
676 if (mask
& __GFP_WAIT
)
681 static void wait_on_state(struct extent_io_tree
*tree
,
682 struct extent_state
*state
)
683 __releases(tree
->lock
)
684 __acquires(tree
->lock
)
687 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
688 spin_unlock(&tree
->lock
);
690 spin_lock(&tree
->lock
);
691 finish_wait(&state
->wq
, &wait
);
695 * waits for one or more bits to clear on a range in the state tree.
696 * The range [start, end] is inclusive.
697 * The tree lock is taken by this function
699 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
702 struct extent_state
*state
;
703 struct rb_node
*node
;
705 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
707 spin_lock(&tree
->lock
);
711 * this search will find all the extents that end after
714 node
= tree_search(tree
, start
);
718 state
= rb_entry(node
, struct extent_state
, rb_node
);
720 if (state
->start
> end
)
723 if (state
->state
& bits
) {
724 start
= state
->start
;
725 atomic_inc(&state
->refs
);
726 wait_on_state(tree
, state
);
727 free_extent_state(state
);
730 start
= state
->end
+ 1;
735 cond_resched_lock(&tree
->lock
);
738 spin_unlock(&tree
->lock
);
741 static void set_state_bits(struct extent_io_tree
*tree
,
742 struct extent_state
*state
,
745 unsigned long bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
747 set_state_cb(tree
, state
, bits
);
748 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
749 u64 range
= state
->end
- state
->start
+ 1;
750 tree
->dirty_bytes
+= range
;
752 state
->state
|= bits_to_set
;
755 static void cache_state(struct extent_state
*state
,
756 struct extent_state
**cached_ptr
)
758 if (cached_ptr
&& !(*cached_ptr
)) {
759 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
)) {
761 atomic_inc(&state
->refs
);
767 * set some bits on a range in the tree. This may require allocations or
768 * sleeping, so the gfp mask is used to indicate what is allowed.
770 * If any of the exclusive bits are set, this will fail with -EEXIST if some
771 * part of the range already has the desired bits set. The start of the
772 * existing range is returned in failed_start in this case.
774 * [start, end] is inclusive This takes the tree lock.
777 static int __must_check
778 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
779 unsigned long bits
, unsigned long exclusive_bits
,
780 u64
*failed_start
, struct extent_state
**cached_state
,
783 struct extent_state
*state
;
784 struct extent_state
*prealloc
= NULL
;
785 struct rb_node
*node
;
790 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
792 bits
|= EXTENT_FIRST_DELALLOC
;
794 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
795 prealloc
= alloc_extent_state(mask
);
799 spin_lock(&tree
->lock
);
800 if (cached_state
&& *cached_state
) {
801 state
= *cached_state
;
802 if (state
->start
<= start
&& state
->end
> start
&&
804 node
= &state
->rb_node
;
809 * this search will find all the extents that end after
812 node
= tree_search(tree
, start
);
814 prealloc
= alloc_extent_state_atomic(prealloc
);
816 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
818 extent_io_tree_panic(tree
, err
);
823 state
= rb_entry(node
, struct extent_state
, rb_node
);
825 last_start
= state
->start
;
826 last_end
= state
->end
;
829 * | ---- desired range ---- |
832 * Just lock what we found and keep going
834 if (state
->start
== start
&& state
->end
<= end
) {
835 if (state
->state
& exclusive_bits
) {
836 *failed_start
= state
->start
;
841 set_state_bits(tree
, state
, &bits
);
842 cache_state(state
, cached_state
);
843 merge_state(tree
, state
);
844 if (last_end
== (u64
)-1)
846 start
= last_end
+ 1;
847 state
= next_state(state
);
848 if (start
< end
&& state
&& state
->start
== start
&&
855 * | ---- desired range ---- |
858 * | ------------- state -------------- |
860 * We need to split the extent we found, and may flip bits on
863 * If the extent we found extends past our
864 * range, we just split and search again. It'll get split
865 * again the next time though.
867 * If the extent we found is inside our range, we set the
870 if (state
->start
< start
) {
871 if (state
->state
& exclusive_bits
) {
872 *failed_start
= start
;
877 prealloc
= alloc_extent_state_atomic(prealloc
);
879 err
= split_state(tree
, state
, prealloc
, start
);
881 extent_io_tree_panic(tree
, err
);
886 if (state
->end
<= end
) {
887 set_state_bits(tree
, state
, &bits
);
888 cache_state(state
, cached_state
);
889 merge_state(tree
, state
);
890 if (last_end
== (u64
)-1)
892 start
= last_end
+ 1;
893 state
= next_state(state
);
894 if (start
< end
&& state
&& state
->start
== start
&&
901 * | ---- desired range ---- |
902 * | state | or | state |
904 * There's a hole, we need to insert something in it and
905 * ignore the extent we found.
907 if (state
->start
> start
) {
909 if (end
< last_start
)
912 this_end
= last_start
- 1;
914 prealloc
= alloc_extent_state_atomic(prealloc
);
918 * Avoid to free 'prealloc' if it can be merged with
921 err
= insert_state(tree
, prealloc
, start
, this_end
,
924 extent_io_tree_panic(tree
, err
);
926 cache_state(prealloc
, cached_state
);
928 start
= this_end
+ 1;
932 * | ---- desired range ---- |
934 * We need to split the extent, and set the bit
937 if (state
->start
<= end
&& state
->end
> end
) {
938 if (state
->state
& exclusive_bits
) {
939 *failed_start
= start
;
944 prealloc
= alloc_extent_state_atomic(prealloc
);
946 err
= split_state(tree
, state
, prealloc
, end
+ 1);
948 extent_io_tree_panic(tree
, err
);
950 set_state_bits(tree
, prealloc
, &bits
);
951 cache_state(prealloc
, cached_state
);
952 merge_state(tree
, prealloc
);
960 spin_unlock(&tree
->lock
);
962 free_extent_state(prealloc
);
969 spin_unlock(&tree
->lock
);
970 if (mask
& __GFP_WAIT
)
975 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
976 unsigned long bits
, u64
* failed_start
,
977 struct extent_state
**cached_state
, gfp_t mask
)
979 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
985 * convert_extent_bit - convert all bits in a given range from one bit to
987 * @tree: the io tree to search
988 * @start: the start offset in bytes
989 * @end: the end offset in bytes (inclusive)
990 * @bits: the bits to set in this range
991 * @clear_bits: the bits to clear in this range
992 * @cached_state: state that we're going to cache
993 * @mask: the allocation mask
995 * This will go through and set bits for the given range. If any states exist
996 * already in this range they are set with the given bit and cleared of the
997 * clear_bits. This is only meant to be used by things that are mergeable, ie
998 * converting from say DELALLOC to DIRTY. This is not meant to be used with
999 * boundary bits like LOCK.
1001 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1002 unsigned long bits
, unsigned long clear_bits
,
1003 struct extent_state
**cached_state
, gfp_t mask
)
1005 struct extent_state
*state
;
1006 struct extent_state
*prealloc
= NULL
;
1007 struct rb_node
*node
;
1012 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
1015 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
1016 prealloc
= alloc_extent_state(mask
);
1021 spin_lock(&tree
->lock
);
1022 if (cached_state
&& *cached_state
) {
1023 state
= *cached_state
;
1024 if (state
->start
<= start
&& state
->end
> start
&&
1026 node
= &state
->rb_node
;
1032 * this search will find all the extents that end after
1035 node
= tree_search(tree
, start
);
1037 prealloc
= alloc_extent_state_atomic(prealloc
);
1042 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
1045 extent_io_tree_panic(tree
, err
);
1048 state
= rb_entry(node
, struct extent_state
, rb_node
);
1050 last_start
= state
->start
;
1051 last_end
= state
->end
;
1054 * | ---- desired range ---- |
1057 * Just lock what we found and keep going
1059 if (state
->start
== start
&& state
->end
<= end
) {
1060 set_state_bits(tree
, state
, &bits
);
1061 cache_state(state
, cached_state
);
1062 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1063 if (last_end
== (u64
)-1)
1065 start
= last_end
+ 1;
1066 if (start
< end
&& state
&& state
->start
== start
&&
1073 * | ---- desired range ---- |
1076 * | ------------- state -------------- |
1078 * We need to split the extent we found, and may flip bits on
1081 * If the extent we found extends past our
1082 * range, we just split and search again. It'll get split
1083 * again the next time though.
1085 * If the extent we found is inside our range, we set the
1086 * desired bit on it.
1088 if (state
->start
< start
) {
1089 prealloc
= alloc_extent_state_atomic(prealloc
);
1094 err
= split_state(tree
, state
, prealloc
, start
);
1096 extent_io_tree_panic(tree
, err
);
1100 if (state
->end
<= end
) {
1101 set_state_bits(tree
, state
, &bits
);
1102 cache_state(state
, cached_state
);
1103 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1104 if (last_end
== (u64
)-1)
1106 start
= last_end
+ 1;
1107 if (start
< end
&& state
&& state
->start
== start
&&
1114 * | ---- desired range ---- |
1115 * | state | or | state |
1117 * There's a hole, we need to insert something in it and
1118 * ignore the extent we found.
1120 if (state
->start
> start
) {
1122 if (end
< last_start
)
1125 this_end
= last_start
- 1;
1127 prealloc
= alloc_extent_state_atomic(prealloc
);
1134 * Avoid to free 'prealloc' if it can be merged with
1137 err
= insert_state(tree
, prealloc
, start
, this_end
,
1140 extent_io_tree_panic(tree
, err
);
1141 cache_state(prealloc
, cached_state
);
1143 start
= this_end
+ 1;
1147 * | ---- desired range ---- |
1149 * We need to split the extent, and set the bit
1152 if (state
->start
<= end
&& state
->end
> end
) {
1153 prealloc
= alloc_extent_state_atomic(prealloc
);
1159 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1161 extent_io_tree_panic(tree
, err
);
1163 set_state_bits(tree
, prealloc
, &bits
);
1164 cache_state(prealloc
, cached_state
);
1165 clear_state_bit(tree
, prealloc
, &clear_bits
, 0);
1173 spin_unlock(&tree
->lock
);
1175 free_extent_state(prealloc
);
1182 spin_unlock(&tree
->lock
);
1183 if (mask
& __GFP_WAIT
)
1188 /* wrappers around set/clear extent bit */
1189 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1192 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, NULL
,
1196 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1197 unsigned long bits
, gfp_t mask
)
1199 return set_extent_bit(tree
, start
, end
, bits
, NULL
,
1203 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1204 unsigned long bits
, gfp_t mask
)
1206 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, mask
);
1209 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1210 struct extent_state
**cached_state
, gfp_t mask
)
1212 return set_extent_bit(tree
, start
, end
,
1213 EXTENT_DELALLOC
| EXTENT_UPTODATE
,
1214 NULL
, cached_state
, mask
);
1217 int set_extent_defrag(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1218 struct extent_state
**cached_state
, gfp_t mask
)
1220 return set_extent_bit(tree
, start
, end
,
1221 EXTENT_DELALLOC
| EXTENT_UPTODATE
| EXTENT_DEFRAG
,
1222 NULL
, cached_state
, mask
);
1225 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1228 return clear_extent_bit(tree
, start
, end
,
1229 EXTENT_DIRTY
| EXTENT_DELALLOC
|
1230 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
, mask
);
1233 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1236 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, NULL
,
1240 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1241 struct extent_state
**cached_state
, gfp_t mask
)
1243 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, NULL
,
1244 cached_state
, mask
);
1247 int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1248 struct extent_state
**cached_state
, gfp_t mask
)
1250 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0,
1251 cached_state
, mask
);
1255 * either insert or lock state struct between start and end use mask to tell
1256 * us if waiting is desired.
1258 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1259 unsigned long bits
, struct extent_state
**cached_state
)
1264 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
1265 EXTENT_LOCKED
, &failed_start
,
1266 cached_state
, GFP_NOFS
);
1267 if (err
== -EEXIST
) {
1268 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1269 start
= failed_start
;
1272 WARN_ON(start
> end
);
1277 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1279 return lock_extent_bits(tree
, start
, end
, 0, NULL
);
1282 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1287 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1288 &failed_start
, NULL
, GFP_NOFS
);
1289 if (err
== -EEXIST
) {
1290 if (failed_start
> start
)
1291 clear_extent_bit(tree
, start
, failed_start
- 1,
1292 EXTENT_LOCKED
, 1, 0, NULL
, GFP_NOFS
);
1298 int unlock_extent_cached(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1299 struct extent_state
**cached
, gfp_t mask
)
1301 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, cached
,
1305 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1307 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, NULL
,
1311 int extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1313 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1314 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1317 while (index
<= end_index
) {
1318 page
= find_get_page(inode
->i_mapping
, index
);
1319 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1320 clear_page_dirty_for_io(page
);
1321 page_cache_release(page
);
1327 int extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1329 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1330 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1333 while (index
<= end_index
) {
1334 page
= find_get_page(inode
->i_mapping
, index
);
1335 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1336 account_page_redirty(page
);
1337 __set_page_dirty_nobuffers(page
);
1338 page_cache_release(page
);
1345 * helper function to set both pages and extents in the tree writeback
1347 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1349 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1350 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1353 while (index
<= end_index
) {
1354 page
= find_get_page(tree
->mapping
, index
);
1355 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1356 set_page_writeback(page
);
1357 page_cache_release(page
);
1363 /* find the first state struct with 'bits' set after 'start', and
1364 * return it. tree->lock must be held. NULL will returned if
1365 * nothing was found after 'start'
1367 static struct extent_state
*
1368 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1369 u64 start
, unsigned long bits
)
1371 struct rb_node
*node
;
1372 struct extent_state
*state
;
1375 * this search will find all the extents that end after
1378 node
= tree_search(tree
, start
);
1383 state
= rb_entry(node
, struct extent_state
, rb_node
);
1384 if (state
->end
>= start
&& (state
->state
& bits
))
1387 node
= rb_next(node
);
1396 * find the first offset in the io tree with 'bits' set. zero is
1397 * returned if we find something, and *start_ret and *end_ret are
1398 * set to reflect the state struct that was found.
1400 * If nothing was found, 1 is returned. If found something, return 0.
1402 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1403 u64
*start_ret
, u64
*end_ret
, unsigned long bits
,
1404 struct extent_state
**cached_state
)
1406 struct extent_state
*state
;
1410 spin_lock(&tree
->lock
);
1411 if (cached_state
&& *cached_state
) {
1412 state
= *cached_state
;
1413 if (state
->end
== start
- 1 && state
->tree
) {
1414 n
= rb_next(&state
->rb_node
);
1416 state
= rb_entry(n
, struct extent_state
,
1418 if (state
->state
& bits
)
1422 free_extent_state(*cached_state
);
1423 *cached_state
= NULL
;
1426 free_extent_state(*cached_state
);
1427 *cached_state
= NULL
;
1430 state
= find_first_extent_bit_state(tree
, start
, bits
);
1433 cache_state(state
, cached_state
);
1434 *start_ret
= state
->start
;
1435 *end_ret
= state
->end
;
1439 spin_unlock(&tree
->lock
);
1444 * find a contiguous range of bytes in the file marked as delalloc, not
1445 * more than 'max_bytes'. start and end are used to return the range,
1447 * 1 is returned if we find something, 0 if nothing was in the tree
1449 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1450 u64
*start
, u64
*end
, u64 max_bytes
,
1451 struct extent_state
**cached_state
)
1453 struct rb_node
*node
;
1454 struct extent_state
*state
;
1455 u64 cur_start
= *start
;
1457 u64 total_bytes
= 0;
1459 spin_lock(&tree
->lock
);
1462 * this search will find all the extents that end after
1465 node
= tree_search(tree
, cur_start
);
1473 state
= rb_entry(node
, struct extent_state
, rb_node
);
1474 if (found
&& (state
->start
!= cur_start
||
1475 (state
->state
& EXTENT_BOUNDARY
))) {
1478 if (!(state
->state
& EXTENT_DELALLOC
)) {
1484 *start
= state
->start
;
1485 *cached_state
= state
;
1486 atomic_inc(&state
->refs
);
1490 cur_start
= state
->end
+ 1;
1491 node
= rb_next(node
);
1492 total_bytes
+= state
->end
- state
->start
+ 1;
1493 if (total_bytes
>= max_bytes
)
1499 spin_unlock(&tree
->lock
);
1503 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1504 struct page
*locked_page
,
1508 struct page
*pages
[16];
1509 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1510 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1511 unsigned long nr_pages
= end_index
- index
+ 1;
1514 if (index
== locked_page
->index
&& end_index
== index
)
1517 while (nr_pages
> 0) {
1518 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1519 min_t(unsigned long, nr_pages
,
1520 ARRAY_SIZE(pages
)), pages
);
1521 for (i
= 0; i
< ret
; i
++) {
1522 if (pages
[i
] != locked_page
)
1523 unlock_page(pages
[i
]);
1524 page_cache_release(pages
[i
]);
1532 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1533 struct page
*locked_page
,
1537 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1538 unsigned long start_index
= index
;
1539 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1540 unsigned long pages_locked
= 0;
1541 struct page
*pages
[16];
1542 unsigned long nrpages
;
1546 /* the caller is responsible for locking the start index */
1547 if (index
== locked_page
->index
&& index
== end_index
)
1550 /* skip the page at the start index */
1551 nrpages
= end_index
- index
+ 1;
1552 while (nrpages
> 0) {
1553 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1554 min_t(unsigned long,
1555 nrpages
, ARRAY_SIZE(pages
)), pages
);
1560 /* now we have an array of pages, lock them all */
1561 for (i
= 0; i
< ret
; i
++) {
1563 * the caller is taking responsibility for
1566 if (pages
[i
] != locked_page
) {
1567 lock_page(pages
[i
]);
1568 if (!PageDirty(pages
[i
]) ||
1569 pages
[i
]->mapping
!= inode
->i_mapping
) {
1571 unlock_page(pages
[i
]);
1572 page_cache_release(pages
[i
]);
1576 page_cache_release(pages
[i
]);
1585 if (ret
&& pages_locked
) {
1586 __unlock_for_delalloc(inode
, locked_page
,
1588 ((u64
)(start_index
+ pages_locked
- 1)) <<
1595 * find a contiguous range of bytes in the file marked as delalloc, not
1596 * more than 'max_bytes'. start and end are used to return the range,
1598 * 1 is returned if we find something, 0 if nothing was in the tree
1600 STATIC u64
find_lock_delalloc_range(struct inode
*inode
,
1601 struct extent_io_tree
*tree
,
1602 struct page
*locked_page
, u64
*start
,
1603 u64
*end
, u64 max_bytes
)
1608 struct extent_state
*cached_state
= NULL
;
1613 /* step one, find a bunch of delalloc bytes starting at start */
1614 delalloc_start
= *start
;
1616 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1617 max_bytes
, &cached_state
);
1618 if (!found
|| delalloc_end
<= *start
) {
1619 *start
= delalloc_start
;
1620 *end
= delalloc_end
;
1621 free_extent_state(cached_state
);
1626 * start comes from the offset of locked_page. We have to lock
1627 * pages in order, so we can't process delalloc bytes before
1630 if (delalloc_start
< *start
)
1631 delalloc_start
= *start
;
1634 * make sure to limit the number of pages we try to lock down
1636 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
)
1637 delalloc_end
= delalloc_start
+ max_bytes
- 1;
1639 /* step two, lock all the pages after the page that has start */
1640 ret
= lock_delalloc_pages(inode
, locked_page
,
1641 delalloc_start
, delalloc_end
);
1642 if (ret
== -EAGAIN
) {
1643 /* some of the pages are gone, lets avoid looping by
1644 * shortening the size of the delalloc range we're searching
1646 free_extent_state(cached_state
);
1648 max_bytes
= PAGE_CACHE_SIZE
;
1656 BUG_ON(ret
); /* Only valid values are 0 and -EAGAIN */
1658 /* step three, lock the state bits for the whole range */
1659 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, 0, &cached_state
);
1661 /* then test to make sure it is all still delalloc */
1662 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1663 EXTENT_DELALLOC
, 1, cached_state
);
1665 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1666 &cached_state
, GFP_NOFS
);
1667 __unlock_for_delalloc(inode
, locked_page
,
1668 delalloc_start
, delalloc_end
);
1672 free_extent_state(cached_state
);
1673 *start
= delalloc_start
;
1674 *end
= delalloc_end
;
1679 int extent_clear_unlock_delalloc(struct inode
*inode
, u64 start
, u64 end
,
1680 struct page
*locked_page
,
1681 unsigned long clear_bits
,
1682 unsigned long page_ops
)
1684 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
1686 struct page
*pages
[16];
1687 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1688 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1689 unsigned long nr_pages
= end_index
- index
+ 1;
1692 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, NULL
, GFP_NOFS
);
1696 while (nr_pages
> 0) {
1697 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1698 min_t(unsigned long,
1699 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1700 for (i
= 0; i
< ret
; i
++) {
1702 if (page_ops
& PAGE_SET_PRIVATE2
)
1703 SetPagePrivate2(pages
[i
]);
1705 if (pages
[i
] == locked_page
) {
1706 page_cache_release(pages
[i
]);
1709 if (page_ops
& PAGE_CLEAR_DIRTY
)
1710 clear_page_dirty_for_io(pages
[i
]);
1711 if (page_ops
& PAGE_SET_WRITEBACK
)
1712 set_page_writeback(pages
[i
]);
1713 if (page_ops
& PAGE_END_WRITEBACK
)
1714 end_page_writeback(pages
[i
]);
1715 if (page_ops
& PAGE_UNLOCK
)
1716 unlock_page(pages
[i
]);
1717 page_cache_release(pages
[i
]);
1727 * count the number of bytes in the tree that have a given bit(s)
1728 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1729 * cached. The total number found is returned.
1731 u64
count_range_bits(struct extent_io_tree
*tree
,
1732 u64
*start
, u64 search_end
, u64 max_bytes
,
1733 unsigned long bits
, int contig
)
1735 struct rb_node
*node
;
1736 struct extent_state
*state
;
1737 u64 cur_start
= *start
;
1738 u64 total_bytes
= 0;
1742 if (WARN_ON(search_end
<= cur_start
))
1745 spin_lock(&tree
->lock
);
1746 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1747 total_bytes
= tree
->dirty_bytes
;
1751 * this search will find all the extents that end after
1754 node
= tree_search(tree
, cur_start
);
1759 state
= rb_entry(node
, struct extent_state
, rb_node
);
1760 if (state
->start
> search_end
)
1762 if (contig
&& found
&& state
->start
> last
+ 1)
1764 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1765 total_bytes
+= min(search_end
, state
->end
) + 1 -
1766 max(cur_start
, state
->start
);
1767 if (total_bytes
>= max_bytes
)
1770 *start
= max(cur_start
, state
->start
);
1774 } else if (contig
&& found
) {
1777 node
= rb_next(node
);
1782 spin_unlock(&tree
->lock
);
1787 * set the private field for a given byte offset in the tree. If there isn't
1788 * an extent_state there already, this does nothing.
1790 static int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1792 struct rb_node
*node
;
1793 struct extent_state
*state
;
1796 spin_lock(&tree
->lock
);
1798 * this search will find all the extents that end after
1801 node
= tree_search(tree
, start
);
1806 state
= rb_entry(node
, struct extent_state
, rb_node
);
1807 if (state
->start
!= start
) {
1811 state
->private = private;
1813 spin_unlock(&tree
->lock
);
1817 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1819 struct rb_node
*node
;
1820 struct extent_state
*state
;
1823 spin_lock(&tree
->lock
);
1825 * this search will find all the extents that end after
1828 node
= tree_search(tree
, start
);
1833 state
= rb_entry(node
, struct extent_state
, rb_node
);
1834 if (state
->start
!= start
) {
1838 *private = state
->private;
1840 spin_unlock(&tree
->lock
);
1845 * searches a range in the state tree for a given mask.
1846 * If 'filled' == 1, this returns 1 only if every extent in the tree
1847 * has the bits set. Otherwise, 1 is returned if any bit in the
1848 * range is found set.
1850 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1851 unsigned long bits
, int filled
, struct extent_state
*cached
)
1853 struct extent_state
*state
= NULL
;
1854 struct rb_node
*node
;
1857 spin_lock(&tree
->lock
);
1858 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
1859 cached
->end
> start
)
1860 node
= &cached
->rb_node
;
1862 node
= tree_search(tree
, start
);
1863 while (node
&& start
<= end
) {
1864 state
= rb_entry(node
, struct extent_state
, rb_node
);
1866 if (filled
&& state
->start
> start
) {
1871 if (state
->start
> end
)
1874 if (state
->state
& bits
) {
1878 } else if (filled
) {
1883 if (state
->end
== (u64
)-1)
1886 start
= state
->end
+ 1;
1889 node
= rb_next(node
);
1896 spin_unlock(&tree
->lock
);
1901 * helper function to set a given page up to date if all the
1902 * extents in the tree for that page are up to date
1904 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
1906 u64 start
= page_offset(page
);
1907 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1908 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1909 SetPageUptodate(page
);
1913 * When IO fails, either with EIO or csum verification fails, we
1914 * try other mirrors that might have a good copy of the data. This
1915 * io_failure_record is used to record state as we go through all the
1916 * mirrors. If another mirror has good data, the page is set up to date
1917 * and things continue. If a good mirror can't be found, the original
1918 * bio end_io callback is called to indicate things have failed.
1920 struct io_failure_record
{
1925 unsigned long bio_flags
;
1931 static int free_io_failure(struct inode
*inode
, struct io_failure_record
*rec
,
1936 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
1938 set_state_private(failure_tree
, rec
->start
, 0);
1939 ret
= clear_extent_bits(failure_tree
, rec
->start
,
1940 rec
->start
+ rec
->len
- 1,
1941 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
1945 ret
= clear_extent_bits(&BTRFS_I(inode
)->io_tree
, rec
->start
,
1946 rec
->start
+ rec
->len
- 1,
1947 EXTENT_DAMAGED
, GFP_NOFS
);
1956 * this bypasses the standard btrfs submit functions deliberately, as
1957 * the standard behavior is to write all copies in a raid setup. here we only
1958 * want to write the one bad copy. so we do the mapping for ourselves and issue
1959 * submit_bio directly.
1960 * to avoid any synchronization issues, wait for the data after writing, which
1961 * actually prevents the read that triggered the error from finishing.
1962 * currently, there can be no more than two copies of every data bit. thus,
1963 * exactly one rewrite is required.
1965 int repair_io_failure(struct btrfs_fs_info
*fs_info
, u64 start
,
1966 u64 length
, u64 logical
, struct page
*page
,
1970 struct btrfs_device
*dev
;
1973 struct btrfs_bio
*bbio
= NULL
;
1974 struct btrfs_mapping_tree
*map_tree
= &fs_info
->mapping_tree
;
1977 ASSERT(!(fs_info
->sb
->s_flags
& MS_RDONLY
));
1978 BUG_ON(!mirror_num
);
1980 /* we can't repair anything in raid56 yet */
1981 if (btrfs_is_parity_mirror(map_tree
, logical
, length
, mirror_num
))
1984 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
1988 map_length
= length
;
1990 ret
= btrfs_map_block(fs_info
, WRITE
, logical
,
1991 &map_length
, &bbio
, mirror_num
);
1996 BUG_ON(mirror_num
!= bbio
->mirror_num
);
1997 sector
= bbio
->stripes
[mirror_num
-1].physical
>> 9;
1998 bio
->bi_sector
= sector
;
1999 dev
= bbio
->stripes
[mirror_num
-1].dev
;
2001 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2005 bio
->bi_bdev
= dev
->bdev
;
2006 bio_add_page(bio
, page
, length
, start
- page_offset(page
));
2008 if (btrfsic_submit_bio_wait(WRITE_SYNC
, bio
)) {
2009 /* try to remap that extent elsewhere? */
2011 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2015 printk_ratelimited_in_rcu(KERN_INFO
"btrfs read error corrected: ino %lu off %llu "
2016 "(dev %s sector %llu)\n", page
->mapping
->host
->i_ino
,
2017 start
, rcu_str_deref(dev
->name
), sector
);
2023 int repair_eb_io_failure(struct btrfs_root
*root
, struct extent_buffer
*eb
,
2026 u64 start
= eb
->start
;
2027 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2030 if (root
->fs_info
->sb
->s_flags
& MS_RDONLY
)
2033 for (i
= 0; i
< num_pages
; i
++) {
2034 struct page
*p
= extent_buffer_page(eb
, i
);
2035 ret
= repair_io_failure(root
->fs_info
, start
, PAGE_CACHE_SIZE
,
2036 start
, p
, mirror_num
);
2039 start
+= PAGE_CACHE_SIZE
;
2046 * each time an IO finishes, we do a fast check in the IO failure tree
2047 * to see if we need to process or clean up an io_failure_record
2049 static int clean_io_failure(u64 start
, struct page
*page
)
2052 u64 private_failure
;
2053 struct io_failure_record
*failrec
;
2054 struct inode
*inode
= page
->mapping
->host
;
2055 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2056 struct extent_state
*state
;
2062 ret
= count_range_bits(&BTRFS_I(inode
)->io_failure_tree
, &private,
2063 (u64
)-1, 1, EXTENT_DIRTY
, 0);
2067 ret
= get_state_private(&BTRFS_I(inode
)->io_failure_tree
, start
,
2072 failrec
= (struct io_failure_record
*)(unsigned long) private_failure
;
2073 BUG_ON(!failrec
->this_mirror
);
2075 if (failrec
->in_validation
) {
2076 /* there was no real error, just free the record */
2077 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2082 if (fs_info
->sb
->s_flags
& MS_RDONLY
)
2085 spin_lock(&BTRFS_I(inode
)->io_tree
.lock
);
2086 state
= find_first_extent_bit_state(&BTRFS_I(inode
)->io_tree
,
2089 spin_unlock(&BTRFS_I(inode
)->io_tree
.lock
);
2091 if (state
&& state
->start
<= failrec
->start
&&
2092 state
->end
>= failrec
->start
+ failrec
->len
- 1) {
2093 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2095 if (num_copies
> 1) {
2096 ret
= repair_io_failure(fs_info
, start
, failrec
->len
,
2097 failrec
->logical
, page
,
2098 failrec
->failed_mirror
);
2106 ret
= free_io_failure(inode
, failrec
, did_repair
);
2112 * this is a generic handler for readpage errors (default
2113 * readpage_io_failed_hook). if other copies exist, read those and write back
2114 * good data to the failed position. does not investigate in remapping the
2115 * failed extent elsewhere, hoping the device will be smart enough to do this as
2119 static int bio_readpage_error(struct bio
*failed_bio
, u64 phy_offset
,
2120 struct page
*page
, u64 start
, u64 end
,
2123 struct io_failure_record
*failrec
= NULL
;
2125 struct extent_map
*em
;
2126 struct inode
*inode
= page
->mapping
->host
;
2127 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2128 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2129 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2131 struct btrfs_io_bio
*btrfs_failed_bio
;
2132 struct btrfs_io_bio
*btrfs_bio
;
2138 BUG_ON(failed_bio
->bi_rw
& REQ_WRITE
);
2140 ret
= get_state_private(failure_tree
, start
, &private);
2142 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2145 failrec
->start
= start
;
2146 failrec
->len
= end
- start
+ 1;
2147 failrec
->this_mirror
= 0;
2148 failrec
->bio_flags
= 0;
2149 failrec
->in_validation
= 0;
2151 read_lock(&em_tree
->lock
);
2152 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2154 read_unlock(&em_tree
->lock
);
2159 if (em
->start
> start
|| em
->start
+ em
->len
< start
) {
2160 free_extent_map(em
);
2163 read_unlock(&em_tree
->lock
);
2169 logical
= start
- em
->start
;
2170 logical
= em
->block_start
+ logical
;
2171 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2172 logical
= em
->block_start
;
2173 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2174 extent_set_compress_type(&failrec
->bio_flags
,
2177 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2178 "len=%llu\n", logical
, start
, failrec
->len
);
2179 failrec
->logical
= logical
;
2180 free_extent_map(em
);
2182 /* set the bits in the private failure tree */
2183 ret
= set_extent_bits(failure_tree
, start
, end
,
2184 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
2186 ret
= set_state_private(failure_tree
, start
,
2187 (u64
)(unsigned long)failrec
);
2188 /* set the bits in the inode's tree */
2190 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
,
2197 failrec
= (struct io_failure_record
*)(unsigned long)private;
2198 pr_debug("bio_readpage_error: (found) logical=%llu, "
2199 "start=%llu, len=%llu, validation=%d\n",
2200 failrec
->logical
, failrec
->start
, failrec
->len
,
2201 failrec
->in_validation
);
2203 * when data can be on disk more than twice, add to failrec here
2204 * (e.g. with a list for failed_mirror) to make
2205 * clean_io_failure() clean all those errors at once.
2208 num_copies
= btrfs_num_copies(BTRFS_I(inode
)->root
->fs_info
,
2209 failrec
->logical
, failrec
->len
);
2210 if (num_copies
== 1) {
2212 * we only have a single copy of the data, so don't bother with
2213 * all the retry and error correction code that follows. no
2214 * matter what the error is, it is very likely to persist.
2216 pr_debug("bio_readpage_error: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
2217 num_copies
, failrec
->this_mirror
, failed_mirror
);
2218 free_io_failure(inode
, failrec
, 0);
2223 * there are two premises:
2224 * a) deliver good data to the caller
2225 * b) correct the bad sectors on disk
2227 if (failed_bio
->bi_vcnt
> 1) {
2229 * to fulfill b), we need to know the exact failing sectors, as
2230 * we don't want to rewrite any more than the failed ones. thus,
2231 * we need separate read requests for the failed bio
2233 * if the following BUG_ON triggers, our validation request got
2234 * merged. we need separate requests for our algorithm to work.
2236 BUG_ON(failrec
->in_validation
);
2237 failrec
->in_validation
= 1;
2238 failrec
->this_mirror
= failed_mirror
;
2239 read_mode
= READ_SYNC
| REQ_FAILFAST_DEV
;
2242 * we're ready to fulfill a) and b) alongside. get a good copy
2243 * of the failed sector and if we succeed, we have setup
2244 * everything for repair_io_failure to do the rest for us.
2246 if (failrec
->in_validation
) {
2247 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2248 failrec
->in_validation
= 0;
2249 failrec
->this_mirror
= 0;
2251 failrec
->failed_mirror
= failed_mirror
;
2252 failrec
->this_mirror
++;
2253 if (failrec
->this_mirror
== failed_mirror
)
2254 failrec
->this_mirror
++;
2255 read_mode
= READ_SYNC
;
2258 if (failrec
->this_mirror
> num_copies
) {
2259 pr_debug("bio_readpage_error: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
2260 num_copies
, failrec
->this_mirror
, failed_mirror
);
2261 free_io_failure(inode
, failrec
, 0);
2265 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2267 free_io_failure(inode
, failrec
, 0);
2270 bio
->bi_end_io
= failed_bio
->bi_end_io
;
2271 bio
->bi_sector
= failrec
->logical
>> 9;
2272 bio
->bi_bdev
= BTRFS_I(inode
)->root
->fs_info
->fs_devices
->latest_bdev
;
2275 btrfs_failed_bio
= btrfs_io_bio(failed_bio
);
2276 if (btrfs_failed_bio
->csum
) {
2277 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2278 u16 csum_size
= btrfs_super_csum_size(fs_info
->super_copy
);
2280 btrfs_bio
= btrfs_io_bio(bio
);
2281 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
2282 phy_offset
>>= inode
->i_sb
->s_blocksize_bits
;
2283 phy_offset
*= csum_size
;
2284 memcpy(btrfs_bio
->csum
, btrfs_failed_bio
->csum
+ phy_offset
,
2288 bio_add_page(bio
, page
, failrec
->len
, start
- page_offset(page
));
2290 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2291 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode
,
2292 failrec
->this_mirror
, num_copies
, failrec
->in_validation
);
2294 ret
= tree
->ops
->submit_bio_hook(inode
, read_mode
, bio
,
2295 failrec
->this_mirror
,
2296 failrec
->bio_flags
, 0);
2300 /* lots and lots of room for performance fixes in the end_bio funcs */
2302 int end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2304 int uptodate
= (err
== 0);
2305 struct extent_io_tree
*tree
;
2308 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2310 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
2311 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
2312 end
, NULL
, uptodate
);
2318 ClearPageUptodate(page
);
2325 * after a writepage IO is done, we need to:
2326 * clear the uptodate bits on error
2327 * clear the writeback bits in the extent tree for this IO
2328 * end_page_writeback if the page has no more pending IO
2330 * Scheduling is not allowed, so the extent state tree is expected
2331 * to have one and only one object corresponding to this IO.
2333 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
2335 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2340 struct page
*page
= bvec
->bv_page
;
2342 /* We always issue full-page reads, but if some block
2343 * in a page fails to read, blk_update_request() will
2344 * advance bv_offset and adjust bv_len to compensate.
2345 * Print a warning for nonzero offsets, and an error
2346 * if they don't add up to a full page. */
2347 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2348 printk("%s page write in btrfs with offset %u and length %u\n",
2349 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2350 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2351 bvec
->bv_offset
, bvec
->bv_len
);
2353 start
= page_offset(page
);
2354 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2356 if (--bvec
>= bio
->bi_io_vec
)
2357 prefetchw(&bvec
->bv_page
->flags
);
2359 if (end_extent_writepage(page
, err
, start
, end
))
2362 end_page_writeback(page
);
2363 } while (bvec
>= bio
->bi_io_vec
);
2369 endio_readpage_release_extent(struct extent_io_tree
*tree
, u64 start
, u64 len
,
2372 struct extent_state
*cached
= NULL
;
2373 u64 end
= start
+ len
- 1;
2375 if (uptodate
&& tree
->track_uptodate
)
2376 set_extent_uptodate(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2377 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2381 * after a readpage IO is done, we need to:
2382 * clear the uptodate bits on error
2383 * set the uptodate bits if things worked
2384 * set the page up to date if all extents in the tree are uptodate
2385 * clear the lock bit in the extent tree
2386 * unlock the page if there are no other extents locked for it
2388 * Scheduling is not allowed, so the extent state tree is expected
2389 * to have one and only one object corresponding to this IO.
2391 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
2393 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2394 struct bio_vec
*bvec_end
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2395 struct bio_vec
*bvec
= bio
->bi_io_vec
;
2396 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2397 struct extent_io_tree
*tree
;
2402 u64 extent_start
= 0;
2411 struct page
*page
= bvec
->bv_page
;
2412 struct inode
*inode
= page
->mapping
->host
;
2414 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2415 "mirror=%lu\n", (u64
)bio
->bi_sector
, err
,
2416 io_bio
->mirror_num
);
2417 tree
= &BTRFS_I(inode
)->io_tree
;
2419 /* We always issue full-page reads, but if some block
2420 * in a page fails to read, blk_update_request() will
2421 * advance bv_offset and adjust bv_len to compensate.
2422 * Print a warning for nonzero offsets, and an error
2423 * if they don't add up to a full page. */
2424 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2425 printk("%s page read in btrfs with offset %u and length %u\n",
2426 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2427 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2428 bvec
->bv_offset
, bvec
->bv_len
);
2430 start
= page_offset(page
);
2431 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2434 if (++bvec
<= bvec_end
)
2435 prefetchw(&bvec
->bv_page
->flags
);
2437 mirror
= io_bio
->mirror_num
;
2438 if (likely(uptodate
&& tree
->ops
&&
2439 tree
->ops
->readpage_end_io_hook
)) {
2440 ret
= tree
->ops
->readpage_end_io_hook(io_bio
, offset
,
2446 clean_io_failure(start
, page
);
2449 if (likely(uptodate
))
2452 if (tree
->ops
&& tree
->ops
->readpage_io_failed_hook
) {
2453 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2455 test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
2459 * The generic bio_readpage_error handles errors the
2460 * following way: If possible, new read requests are
2461 * created and submitted and will end up in
2462 * end_bio_extent_readpage as well (if we're lucky, not
2463 * in the !uptodate case). In that case it returns 0 and
2464 * we just go on with the next page in our bio. If it
2465 * can't handle the error it will return -EIO and we
2466 * remain responsible for that page.
2468 ret
= bio_readpage_error(bio
, offset
, page
, start
, end
,
2472 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2479 if (likely(uptodate
)) {
2480 loff_t i_size
= i_size_read(inode
);
2481 pgoff_t end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2484 /* Zero out the end if this page straddles i_size */
2485 offset
= i_size
& (PAGE_CACHE_SIZE
-1);
2486 if (page
->index
== end_index
&& offset
)
2487 zero_user_segment(page
, offset
, PAGE_CACHE_SIZE
);
2488 SetPageUptodate(page
);
2490 ClearPageUptodate(page
);
2496 if (unlikely(!uptodate
)) {
2498 endio_readpage_release_extent(tree
,
2504 endio_readpage_release_extent(tree
, start
,
2505 end
- start
+ 1, 0);
2506 } else if (!extent_len
) {
2507 extent_start
= start
;
2508 extent_len
= end
+ 1 - start
;
2509 } else if (extent_start
+ extent_len
== start
) {
2510 extent_len
+= end
+ 1 - start
;
2512 endio_readpage_release_extent(tree
, extent_start
,
2513 extent_len
, uptodate
);
2514 extent_start
= start
;
2515 extent_len
= end
+ 1 - start
;
2517 } while (bvec
<= bvec_end
);
2520 endio_readpage_release_extent(tree
, extent_start
, extent_len
,
2523 io_bio
->end_io(io_bio
, err
);
2528 * this allocates from the btrfs_bioset. We're returning a bio right now
2529 * but you can call btrfs_io_bio for the appropriate container_of magic
2532 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
2535 struct btrfs_io_bio
*btrfs_bio
;
2538 bio
= bio_alloc_bioset(gfp_flags
, nr_vecs
, btrfs_bioset
);
2540 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
2541 while (!bio
&& (nr_vecs
/= 2)) {
2542 bio
= bio_alloc_bioset(gfp_flags
,
2543 nr_vecs
, btrfs_bioset
);
2549 bio
->bi_bdev
= bdev
;
2550 bio
->bi_sector
= first_sector
;
2551 btrfs_bio
= btrfs_io_bio(bio
);
2552 btrfs_bio
->csum
= NULL
;
2553 btrfs_bio
->csum_allocated
= NULL
;
2554 btrfs_bio
->end_io
= NULL
;
2559 struct bio
*btrfs_bio_clone(struct bio
*bio
, gfp_t gfp_mask
)
2561 return bio_clone_bioset(bio
, gfp_mask
, btrfs_bioset
);
2565 /* this also allocates from the btrfs_bioset */
2566 struct bio
*btrfs_io_bio_alloc(gfp_t gfp_mask
, unsigned int nr_iovecs
)
2568 struct btrfs_io_bio
*btrfs_bio
;
2571 bio
= bio_alloc_bioset(gfp_mask
, nr_iovecs
, btrfs_bioset
);
2573 btrfs_bio
= btrfs_io_bio(bio
);
2574 btrfs_bio
->csum
= NULL
;
2575 btrfs_bio
->csum_allocated
= NULL
;
2576 btrfs_bio
->end_io
= NULL
;
2582 static int __must_check
submit_one_bio(int rw
, struct bio
*bio
,
2583 int mirror_num
, unsigned long bio_flags
)
2586 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2587 struct page
*page
= bvec
->bv_page
;
2588 struct extent_io_tree
*tree
= bio
->bi_private
;
2591 start
= page_offset(page
) + bvec
->bv_offset
;
2593 bio
->bi_private
= NULL
;
2597 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
2598 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
2599 mirror_num
, bio_flags
, start
);
2601 btrfsic_submit_bio(rw
, bio
);
2603 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
2609 static int merge_bio(int rw
, struct extent_io_tree
*tree
, struct page
*page
,
2610 unsigned long offset
, size_t size
, struct bio
*bio
,
2611 unsigned long bio_flags
)
2614 if (tree
->ops
&& tree
->ops
->merge_bio_hook
)
2615 ret
= tree
->ops
->merge_bio_hook(rw
, page
, offset
, size
, bio
,
2622 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
2623 struct page
*page
, sector_t sector
,
2624 size_t size
, unsigned long offset
,
2625 struct block_device
*bdev
,
2626 struct bio
**bio_ret
,
2627 unsigned long max_pages
,
2628 bio_end_io_t end_io_func
,
2630 unsigned long prev_bio_flags
,
2631 unsigned long bio_flags
)
2637 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
2638 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2639 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
2641 if (bio_ret
&& *bio_ret
) {
2644 contig
= bio
->bi_sector
== sector
;
2646 contig
= bio_end_sector(bio
) == sector
;
2648 if (prev_bio_flags
!= bio_flags
|| !contig
||
2649 merge_bio(rw
, tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2650 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2651 ret
= submit_one_bio(rw
, bio
, mirror_num
,
2660 if (this_compressed
)
2663 nr
= bio_get_nr_vecs(bdev
);
2665 bio
= btrfs_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
2669 bio_add_page(bio
, page
, page_size
, offset
);
2670 bio
->bi_end_io
= end_io_func
;
2671 bio
->bi_private
= tree
;
2676 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
2681 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2684 if (!PagePrivate(page
)) {
2685 SetPagePrivate(page
);
2686 page_cache_get(page
);
2687 set_page_private(page
, (unsigned long)eb
);
2689 WARN_ON(page
->private != (unsigned long)eb
);
2693 void set_page_extent_mapped(struct page
*page
)
2695 if (!PagePrivate(page
)) {
2696 SetPagePrivate(page
);
2697 page_cache_get(page
);
2698 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2702 static struct extent_map
*
2703 __get_extent_map(struct inode
*inode
, struct page
*page
, size_t pg_offset
,
2704 u64 start
, u64 len
, get_extent_t
*get_extent
,
2705 struct extent_map
**em_cached
)
2707 struct extent_map
*em
;
2709 if (em_cached
&& *em_cached
) {
2711 if (em
->in_tree
&& start
>= em
->start
&&
2712 start
< extent_map_end(em
)) {
2713 atomic_inc(&em
->refs
);
2717 free_extent_map(em
);
2721 em
= get_extent(inode
, page
, pg_offset
, start
, len
, 0);
2722 if (em_cached
&& !IS_ERR_OR_NULL(em
)) {
2724 atomic_inc(&em
->refs
);
2730 * basic readpage implementation. Locked extent state structs are inserted
2731 * into the tree that are removed when the IO is done (by the end_io
2733 * XXX JDM: This needs looking at to ensure proper page locking
2735 static int __do_readpage(struct extent_io_tree
*tree
,
2737 get_extent_t
*get_extent
,
2738 struct extent_map
**em_cached
,
2739 struct bio
**bio
, int mirror_num
,
2740 unsigned long *bio_flags
, int rw
)
2742 struct inode
*inode
= page
->mapping
->host
;
2743 u64 start
= page_offset(page
);
2744 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2748 u64 last_byte
= i_size_read(inode
);
2752 struct extent_map
*em
;
2753 struct block_device
*bdev
;
2756 int parent_locked
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2757 size_t pg_offset
= 0;
2759 size_t disk_io_size
;
2760 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2761 unsigned long this_bio_flag
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2763 set_page_extent_mapped(page
);
2766 if (!PageUptodate(page
)) {
2767 if (cleancache_get_page(page
) == 0) {
2768 BUG_ON(blocksize
!= PAGE_SIZE
);
2769 unlock_extent(tree
, start
, end
);
2774 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
2776 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
2779 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
2780 userpage
= kmap_atomic(page
);
2781 memset(userpage
+ zero_offset
, 0, iosize
);
2782 flush_dcache_page(page
);
2783 kunmap_atomic(userpage
);
2786 while (cur
<= end
) {
2787 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2789 if (cur
>= last_byte
) {
2791 struct extent_state
*cached
= NULL
;
2793 iosize
= PAGE_CACHE_SIZE
- pg_offset
;
2794 userpage
= kmap_atomic(page
);
2795 memset(userpage
+ pg_offset
, 0, iosize
);
2796 flush_dcache_page(page
);
2797 kunmap_atomic(userpage
);
2798 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2801 unlock_extent_cached(tree
, cur
,
2806 em
= __get_extent_map(inode
, page
, pg_offset
, cur
,
2807 end
- cur
+ 1, get_extent
, em_cached
);
2808 if (IS_ERR_OR_NULL(em
)) {
2811 unlock_extent(tree
, cur
, end
);
2814 extent_offset
= cur
- em
->start
;
2815 BUG_ON(extent_map_end(em
) <= cur
);
2818 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2819 this_bio_flag
|= EXTENT_BIO_COMPRESSED
;
2820 extent_set_compress_type(&this_bio_flag
,
2824 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2825 cur_end
= min(extent_map_end(em
) - 1, end
);
2826 iosize
= ALIGN(iosize
, blocksize
);
2827 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2828 disk_io_size
= em
->block_len
;
2829 sector
= em
->block_start
>> 9;
2831 sector
= (em
->block_start
+ extent_offset
) >> 9;
2832 disk_io_size
= iosize
;
2835 block_start
= em
->block_start
;
2836 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2837 block_start
= EXTENT_MAP_HOLE
;
2838 free_extent_map(em
);
2841 /* we've found a hole, just zero and go on */
2842 if (block_start
== EXTENT_MAP_HOLE
) {
2844 struct extent_state
*cached
= NULL
;
2846 userpage
= kmap_atomic(page
);
2847 memset(userpage
+ pg_offset
, 0, iosize
);
2848 flush_dcache_page(page
);
2849 kunmap_atomic(userpage
);
2851 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2853 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2856 pg_offset
+= iosize
;
2859 /* the get_extent function already copied into the page */
2860 if (test_range_bit(tree
, cur
, cur_end
,
2861 EXTENT_UPTODATE
, 1, NULL
)) {
2862 check_page_uptodate(tree
, page
);
2864 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2866 pg_offset
+= iosize
;
2869 /* we have an inline extent but it didn't get marked up
2870 * to date. Error out
2872 if (block_start
== EXTENT_MAP_INLINE
) {
2875 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2877 pg_offset
+= iosize
;
2882 ret
= submit_extent_page(rw
, tree
, page
,
2883 sector
, disk_io_size
, pg_offset
,
2885 end_bio_extent_readpage
, mirror_num
,
2890 *bio_flags
= this_bio_flag
;
2894 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2897 pg_offset
+= iosize
;
2901 if (!PageError(page
))
2902 SetPageUptodate(page
);
2908 static inline void __do_contiguous_readpages(struct extent_io_tree
*tree
,
2909 struct page
*pages
[], int nr_pages
,
2911 get_extent_t
*get_extent
,
2912 struct extent_map
**em_cached
,
2913 struct bio
**bio
, int mirror_num
,
2914 unsigned long *bio_flags
, int rw
)
2916 struct inode
*inode
;
2917 struct btrfs_ordered_extent
*ordered
;
2920 inode
= pages
[0]->mapping
->host
;
2922 lock_extent(tree
, start
, end
);
2923 ordered
= btrfs_lookup_ordered_range(inode
, start
,
2927 unlock_extent(tree
, start
, end
);
2928 btrfs_start_ordered_extent(inode
, ordered
, 1);
2929 btrfs_put_ordered_extent(ordered
);
2932 for (index
= 0; index
< nr_pages
; index
++) {
2933 __do_readpage(tree
, pages
[index
], get_extent
, em_cached
, bio
,
2934 mirror_num
, bio_flags
, rw
);
2935 page_cache_release(pages
[index
]);
2939 static void __extent_readpages(struct extent_io_tree
*tree
,
2940 struct page
*pages
[],
2941 int nr_pages
, get_extent_t
*get_extent
,
2942 struct extent_map
**em_cached
,
2943 struct bio
**bio
, int mirror_num
,
2944 unsigned long *bio_flags
, int rw
)
2950 int first_index
= 0;
2952 for (index
= 0; index
< nr_pages
; index
++) {
2953 page_start
= page_offset(pages
[index
]);
2956 end
= start
+ PAGE_CACHE_SIZE
- 1;
2957 first_index
= index
;
2958 } else if (end
+ 1 == page_start
) {
2959 end
+= PAGE_CACHE_SIZE
;
2961 __do_contiguous_readpages(tree
, &pages
[first_index
],
2962 index
- first_index
, start
,
2963 end
, get_extent
, em_cached
,
2964 bio
, mirror_num
, bio_flags
,
2967 end
= start
+ PAGE_CACHE_SIZE
- 1;
2968 first_index
= index
;
2973 __do_contiguous_readpages(tree
, &pages
[first_index
],
2974 index
- first_index
, start
,
2975 end
, get_extent
, em_cached
, bio
,
2976 mirror_num
, bio_flags
, rw
);
2979 static int __extent_read_full_page(struct extent_io_tree
*tree
,
2981 get_extent_t
*get_extent
,
2982 struct bio
**bio
, int mirror_num
,
2983 unsigned long *bio_flags
, int rw
)
2985 struct inode
*inode
= page
->mapping
->host
;
2986 struct btrfs_ordered_extent
*ordered
;
2987 u64 start
= page_offset(page
);
2988 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2992 lock_extent(tree
, start
, end
);
2993 ordered
= btrfs_lookup_ordered_extent(inode
, start
);
2996 unlock_extent(tree
, start
, end
);
2997 btrfs_start_ordered_extent(inode
, ordered
, 1);
2998 btrfs_put_ordered_extent(ordered
);
3001 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, bio
, mirror_num
,
3006 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3007 get_extent_t
*get_extent
, int mirror_num
)
3009 struct bio
*bio
= NULL
;
3010 unsigned long bio_flags
= 0;
3013 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
3016 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3020 int extent_read_full_page_nolock(struct extent_io_tree
*tree
, struct page
*page
,
3021 get_extent_t
*get_extent
, int mirror_num
)
3023 struct bio
*bio
= NULL
;
3024 unsigned long bio_flags
= EXTENT_BIO_PARENT_LOCKED
;
3027 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, &bio
, mirror_num
,
3030 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3034 static noinline
void update_nr_written(struct page
*page
,
3035 struct writeback_control
*wbc
,
3036 unsigned long nr_written
)
3038 wbc
->nr_to_write
-= nr_written
;
3039 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
3040 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
3041 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
3045 * the writepage semantics are similar to regular writepage. extent
3046 * records are inserted to lock ranges in the tree, and as dirty areas
3047 * are found, they are marked writeback. Then the lock bits are removed
3048 * and the end_io handler clears the writeback ranges
3050 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
3053 struct inode
*inode
= page
->mapping
->host
;
3054 struct extent_page_data
*epd
= data
;
3055 struct extent_io_tree
*tree
= epd
->tree
;
3056 u64 start
= page_offset(page
);
3058 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
3062 u64 last_byte
= i_size_read(inode
);
3066 struct extent_state
*cached_state
= NULL
;
3067 struct extent_map
*em
;
3068 struct block_device
*bdev
;
3071 size_t pg_offset
= 0;
3073 loff_t i_size
= i_size_read(inode
);
3074 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
3080 unsigned long nr_written
= 0;
3081 bool fill_delalloc
= true;
3083 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3084 write_flags
= WRITE_SYNC
;
3086 write_flags
= WRITE
;
3088 trace___extent_writepage(page
, inode
, wbc
);
3090 WARN_ON(!PageLocked(page
));
3092 ClearPageError(page
);
3094 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
3095 if (page
->index
> end_index
||
3096 (page
->index
== end_index
&& !pg_offset
)) {
3097 page
->mapping
->a_ops
->invalidatepage(page
, 0, PAGE_CACHE_SIZE
);
3102 if (page
->index
== end_index
) {
3105 userpage
= kmap_atomic(page
);
3106 memset(userpage
+ pg_offset
, 0,
3107 PAGE_CACHE_SIZE
- pg_offset
);
3108 kunmap_atomic(userpage
);
3109 flush_dcache_page(page
);
3113 set_page_extent_mapped(page
);
3115 if (!tree
->ops
|| !tree
->ops
->fill_delalloc
)
3116 fill_delalloc
= false;
3118 delalloc_start
= start
;
3121 if (!epd
->extent_locked
&& fill_delalloc
) {
3122 u64 delalloc_to_write
= 0;
3124 * make sure the wbc mapping index is at least updated
3127 update_nr_written(page
, wbc
, 0);
3129 while (delalloc_end
< page_end
) {
3130 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
3135 if (nr_delalloc
== 0) {
3136 delalloc_start
= delalloc_end
+ 1;
3139 ret
= tree
->ops
->fill_delalloc(inode
, page
,
3144 /* File system has been set read-only */
3150 * delalloc_end is already one less than the total
3151 * length, so we don't subtract one from
3154 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3157 delalloc_start
= delalloc_end
+ 1;
3159 if (wbc
->nr_to_write
< delalloc_to_write
) {
3162 if (delalloc_to_write
< thresh
* 2)
3163 thresh
= delalloc_to_write
;
3164 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3168 /* did the fill delalloc function already unlock and start
3174 * we've unlocked the page, so we can't update
3175 * the mapping's writeback index, just update
3178 wbc
->nr_to_write
-= nr_written
;
3182 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3183 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3186 /* Fixup worker will requeue */
3188 wbc
->pages_skipped
++;
3190 redirty_page_for_writepage(wbc
, page
);
3191 update_nr_written(page
, wbc
, nr_written
);
3199 * we don't want to touch the inode after unlocking the page,
3200 * so we update the mapping writeback index now
3202 update_nr_written(page
, wbc
, nr_written
+ 1);
3205 if (last_byte
<= start
) {
3206 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3207 tree
->ops
->writepage_end_io_hook(page
, start
,
3212 blocksize
= inode
->i_sb
->s_blocksize
;
3214 while (cur
<= end
) {
3215 if (cur
>= last_byte
) {
3216 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3217 tree
->ops
->writepage_end_io_hook(page
, cur
,
3221 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
3223 if (IS_ERR_OR_NULL(em
)) {
3228 extent_offset
= cur
- em
->start
;
3229 BUG_ON(extent_map_end(em
) <= cur
);
3231 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
3232 iosize
= ALIGN(iosize
, blocksize
);
3233 sector
= (em
->block_start
+ extent_offset
) >> 9;
3235 block_start
= em
->block_start
;
3236 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3237 free_extent_map(em
);
3241 * compressed and inline extents are written through other
3244 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3245 block_start
== EXTENT_MAP_INLINE
) {
3247 * end_io notification does not happen here for
3248 * compressed extents
3250 if (!compressed
&& tree
->ops
&&
3251 tree
->ops
->writepage_end_io_hook
)
3252 tree
->ops
->writepage_end_io_hook(page
, cur
,
3255 else if (compressed
) {
3256 /* we don't want to end_page_writeback on
3257 * a compressed extent. this happens
3264 pg_offset
+= iosize
;
3267 /* leave this out until we have a page_mkwrite call */
3268 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
3269 EXTENT_DIRTY
, 0, NULL
)) {
3271 pg_offset
+= iosize
;
3275 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
3276 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
3284 unsigned long max_nr
= end_index
+ 1;
3286 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3287 if (!PageWriteback(page
)) {
3288 printk(KERN_ERR
"btrfs warning page %lu not "
3289 "writeback, cur %llu end %llu\n",
3290 page
->index
, cur
, end
);
3293 ret
= submit_extent_page(write_flags
, tree
, page
,
3294 sector
, iosize
, pg_offset
,
3295 bdev
, &epd
->bio
, max_nr
,
3296 end_bio_extent_writepage
,
3302 pg_offset
+= iosize
;
3307 /* make sure the mapping tag for page dirty gets cleared */
3308 set_page_writeback(page
);
3309 end_page_writeback(page
);
3315 /* drop our reference on any cached states */
3316 free_extent_state(cached_state
);
3320 static int eb_wait(void *word
)
3326 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3328 wait_on_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
, eb_wait
,
3329 TASK_UNINTERRUPTIBLE
);
3332 static int lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3333 struct btrfs_fs_info
*fs_info
,
3334 struct extent_page_data
*epd
)
3336 unsigned long i
, num_pages
;
3340 if (!btrfs_try_tree_write_lock(eb
)) {
3342 flush_write_bio(epd
);
3343 btrfs_tree_lock(eb
);
3346 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3347 btrfs_tree_unlock(eb
);
3351 flush_write_bio(epd
);
3355 wait_on_extent_buffer_writeback(eb
);
3356 btrfs_tree_lock(eb
);
3357 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3359 btrfs_tree_unlock(eb
);
3364 * We need to do this to prevent races in people who check if the eb is
3365 * under IO since we can end up having no IO bits set for a short period
3368 spin_lock(&eb
->refs_lock
);
3369 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3370 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3371 spin_unlock(&eb
->refs_lock
);
3372 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3373 __percpu_counter_add(&fs_info
->dirty_metadata_bytes
,
3375 fs_info
->dirty_metadata_batch
);
3378 spin_unlock(&eb
->refs_lock
);
3381 btrfs_tree_unlock(eb
);
3386 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3387 for (i
= 0; i
< num_pages
; i
++) {
3388 struct page
*p
= extent_buffer_page(eb
, i
);
3390 if (!trylock_page(p
)) {
3392 flush_write_bio(epd
);
3402 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3404 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3405 smp_mb__after_clear_bit();
3406 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3409 static void end_bio_extent_buffer_writepage(struct bio
*bio
, int err
)
3411 int uptodate
= err
== 0;
3412 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
3413 struct extent_buffer
*eb
;
3417 struct page
*page
= bvec
->bv_page
;
3420 eb
= (struct extent_buffer
*)page
->private;
3422 done
= atomic_dec_and_test(&eb
->io_pages
);
3424 if (!uptodate
|| test_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
)) {
3425 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3426 ClearPageUptodate(page
);
3430 end_page_writeback(page
);
3435 end_extent_buffer_writeback(eb
);
3436 } while (bvec
>= bio
->bi_io_vec
);
3442 static int write_one_eb(struct extent_buffer
*eb
,
3443 struct btrfs_fs_info
*fs_info
,
3444 struct writeback_control
*wbc
,
3445 struct extent_page_data
*epd
)
3447 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3448 u64 offset
= eb
->start
;
3449 unsigned long i
, num_pages
;
3450 unsigned long bio_flags
= 0;
3451 int rw
= (epd
->sync_io
? WRITE_SYNC
: WRITE
) | REQ_META
;
3454 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3455 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3456 atomic_set(&eb
->io_pages
, num_pages
);
3457 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3458 bio_flags
= EXTENT_BIO_TREE_LOG
;
3460 for (i
= 0; i
< num_pages
; i
++) {
3461 struct page
*p
= extent_buffer_page(eb
, i
);
3463 clear_page_dirty_for_io(p
);
3464 set_page_writeback(p
);
3465 ret
= submit_extent_page(rw
, eb
->tree
, p
, offset
>> 9,
3466 PAGE_CACHE_SIZE
, 0, bdev
, &epd
->bio
,
3467 -1, end_bio_extent_buffer_writepage
,
3468 0, epd
->bio_flags
, bio_flags
);
3469 epd
->bio_flags
= bio_flags
;
3471 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3473 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3474 end_extent_buffer_writeback(eb
);
3478 offset
+= PAGE_CACHE_SIZE
;
3479 update_nr_written(p
, wbc
, 1);
3483 if (unlikely(ret
)) {
3484 for (; i
< num_pages
; i
++) {
3485 struct page
*p
= extent_buffer_page(eb
, i
);
3493 int btree_write_cache_pages(struct address_space
*mapping
,
3494 struct writeback_control
*wbc
)
3496 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3497 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3498 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3499 struct extent_page_data epd
= {
3503 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3508 int nr_to_write_done
= 0;
3509 struct pagevec pvec
;
3512 pgoff_t end
; /* Inclusive */
3516 pagevec_init(&pvec
, 0);
3517 if (wbc
->range_cyclic
) {
3518 index
= mapping
->writeback_index
; /* Start from prev offset */
3521 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3522 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3525 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3526 tag
= PAGECACHE_TAG_TOWRITE
;
3528 tag
= PAGECACHE_TAG_DIRTY
;
3530 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3531 tag_pages_for_writeback(mapping
, index
, end
);
3532 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3533 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3534 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3538 for (i
= 0; i
< nr_pages
; i
++) {
3539 struct page
*page
= pvec
.pages
[i
];
3541 if (!PagePrivate(page
))
3544 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3549 spin_lock(&mapping
->private_lock
);
3550 if (!PagePrivate(page
)) {
3551 spin_unlock(&mapping
->private_lock
);
3555 eb
= (struct extent_buffer
*)page
->private;
3558 * Shouldn't happen and normally this would be a BUG_ON
3559 * but no sense in crashing the users box for something
3560 * we can survive anyway.
3563 spin_unlock(&mapping
->private_lock
);
3567 if (eb
== prev_eb
) {
3568 spin_unlock(&mapping
->private_lock
);
3572 ret
= atomic_inc_not_zero(&eb
->refs
);
3573 spin_unlock(&mapping
->private_lock
);
3578 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3580 free_extent_buffer(eb
);
3584 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3587 free_extent_buffer(eb
);
3590 free_extent_buffer(eb
);
3593 * the filesystem may choose to bump up nr_to_write.
3594 * We have to make sure to honor the new nr_to_write
3597 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3599 pagevec_release(&pvec
);
3602 if (!scanned
&& !done
) {
3604 * We hit the last page and there is more work to be done: wrap
3605 * back to the start of the file
3611 flush_write_bio(&epd
);
3616 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3617 * @mapping: address space structure to write
3618 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3619 * @writepage: function called for each page
3620 * @data: data passed to writepage function
3622 * If a page is already under I/O, write_cache_pages() skips it, even
3623 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3624 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3625 * and msync() need to guarantee that all the data which was dirty at the time
3626 * the call was made get new I/O started against them. If wbc->sync_mode is
3627 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3628 * existing IO to complete.
3630 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
3631 struct address_space
*mapping
,
3632 struct writeback_control
*wbc
,
3633 writepage_t writepage
, void *data
,
3634 void (*flush_fn
)(void *))
3636 struct inode
*inode
= mapping
->host
;
3639 int nr_to_write_done
= 0;
3640 struct pagevec pvec
;
3643 pgoff_t end
; /* Inclusive */
3648 * We have to hold onto the inode so that ordered extents can do their
3649 * work when the IO finishes. The alternative to this is failing to add
3650 * an ordered extent if the igrab() fails there and that is a huge pain
3651 * to deal with, so instead just hold onto the inode throughout the
3652 * writepages operation. If it fails here we are freeing up the inode
3653 * anyway and we'd rather not waste our time writing out stuff that is
3654 * going to be truncated anyway.
3659 pagevec_init(&pvec
, 0);
3660 if (wbc
->range_cyclic
) {
3661 index
= mapping
->writeback_index
; /* Start from prev offset */
3664 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3665 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3668 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3669 tag
= PAGECACHE_TAG_TOWRITE
;
3671 tag
= PAGECACHE_TAG_DIRTY
;
3673 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3674 tag_pages_for_writeback(mapping
, index
, end
);
3675 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3676 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3677 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3681 for (i
= 0; i
< nr_pages
; i
++) {
3682 struct page
*page
= pvec
.pages
[i
];
3685 * At this point we hold neither mapping->tree_lock nor
3686 * lock on the page itself: the page may be truncated or
3687 * invalidated (changing page->mapping to NULL), or even
3688 * swizzled back from swapper_space to tmpfs file
3691 if (!trylock_page(page
)) {
3696 if (unlikely(page
->mapping
!= mapping
)) {
3701 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3707 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
3708 if (PageWriteback(page
))
3710 wait_on_page_writeback(page
);
3713 if (PageWriteback(page
) ||
3714 !clear_page_dirty_for_io(page
)) {
3719 ret
= (*writepage
)(page
, wbc
, data
);
3721 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
3729 * the filesystem may choose to bump up nr_to_write.
3730 * We have to make sure to honor the new nr_to_write
3733 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3735 pagevec_release(&pvec
);
3738 if (!scanned
&& !done
) {
3740 * We hit the last page and there is more work to be done: wrap
3741 * back to the start of the file
3747 btrfs_add_delayed_iput(inode
);
3751 static void flush_epd_write_bio(struct extent_page_data
*epd
)
3760 ret
= submit_one_bio(rw
, epd
->bio
, 0, epd
->bio_flags
);
3761 BUG_ON(ret
< 0); /* -ENOMEM */
3766 static noinline
void flush_write_bio(void *data
)
3768 struct extent_page_data
*epd
= data
;
3769 flush_epd_write_bio(epd
);
3772 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3773 get_extent_t
*get_extent
,
3774 struct writeback_control
*wbc
)
3777 struct extent_page_data epd
= {
3780 .get_extent
= get_extent
,
3782 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3786 ret
= __extent_writepage(page
, wbc
, &epd
);
3788 flush_epd_write_bio(&epd
);
3792 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
3793 u64 start
, u64 end
, get_extent_t
*get_extent
,
3797 struct address_space
*mapping
= inode
->i_mapping
;
3799 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
3802 struct extent_page_data epd
= {
3805 .get_extent
= get_extent
,
3807 .sync_io
= mode
== WB_SYNC_ALL
,
3810 struct writeback_control wbc_writepages
= {
3812 .nr_to_write
= nr_pages
* 2,
3813 .range_start
= start
,
3814 .range_end
= end
+ 1,
3817 while (start
<= end
) {
3818 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
3819 if (clear_page_dirty_for_io(page
))
3820 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
3822 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3823 tree
->ops
->writepage_end_io_hook(page
, start
,
3824 start
+ PAGE_CACHE_SIZE
- 1,
3828 page_cache_release(page
);
3829 start
+= PAGE_CACHE_SIZE
;
3832 flush_epd_write_bio(&epd
);
3836 int extent_writepages(struct extent_io_tree
*tree
,
3837 struct address_space
*mapping
,
3838 get_extent_t
*get_extent
,
3839 struct writeback_control
*wbc
)
3842 struct extent_page_data epd
= {
3845 .get_extent
= get_extent
,
3847 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3851 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
3852 __extent_writepage
, &epd
,
3854 flush_epd_write_bio(&epd
);
3858 int extent_readpages(struct extent_io_tree
*tree
,
3859 struct address_space
*mapping
,
3860 struct list_head
*pages
, unsigned nr_pages
,
3861 get_extent_t get_extent
)
3863 struct bio
*bio
= NULL
;
3865 unsigned long bio_flags
= 0;
3866 struct page
*pagepool
[16];
3868 struct extent_map
*em_cached
= NULL
;
3871 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
3872 page
= list_entry(pages
->prev
, struct page
, lru
);
3874 prefetchw(&page
->flags
);
3875 list_del(&page
->lru
);
3876 if (add_to_page_cache_lru(page
, mapping
,
3877 page
->index
, GFP_NOFS
)) {
3878 page_cache_release(page
);
3882 pagepool
[nr
++] = page
;
3883 if (nr
< ARRAY_SIZE(pagepool
))
3885 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
3886 &bio
, 0, &bio_flags
, READ
);
3890 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
3891 &bio
, 0, &bio_flags
, READ
);
3894 free_extent_map(em_cached
);
3896 BUG_ON(!list_empty(pages
));
3898 return submit_one_bio(READ
, bio
, 0, bio_flags
);
3903 * basic invalidatepage code, this waits on any locked or writeback
3904 * ranges corresponding to the page, and then deletes any extent state
3905 * records from the tree
3907 int extent_invalidatepage(struct extent_io_tree
*tree
,
3908 struct page
*page
, unsigned long offset
)
3910 struct extent_state
*cached_state
= NULL
;
3911 u64 start
= page_offset(page
);
3912 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3913 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
3915 start
+= ALIGN(offset
, blocksize
);
3919 lock_extent_bits(tree
, start
, end
, 0, &cached_state
);
3920 wait_on_page_writeback(page
);
3921 clear_extent_bit(tree
, start
, end
,
3922 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
3923 EXTENT_DO_ACCOUNTING
,
3924 1, 1, &cached_state
, GFP_NOFS
);
3929 * a helper for releasepage, this tests for areas of the page that
3930 * are locked or under IO and drops the related state bits if it is safe
3933 static int try_release_extent_state(struct extent_map_tree
*map
,
3934 struct extent_io_tree
*tree
,
3935 struct page
*page
, gfp_t mask
)
3937 u64 start
= page_offset(page
);
3938 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3941 if (test_range_bit(tree
, start
, end
,
3942 EXTENT_IOBITS
, 0, NULL
))
3945 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
3948 * at this point we can safely clear everything except the
3949 * locked bit and the nodatasum bit
3951 ret
= clear_extent_bit(tree
, start
, end
,
3952 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
3955 /* if clear_extent_bit failed for enomem reasons,
3956 * we can't allow the release to continue.
3967 * a helper for releasepage. As long as there are no locked extents
3968 * in the range corresponding to the page, both state records and extent
3969 * map records are removed
3971 int try_release_extent_mapping(struct extent_map_tree
*map
,
3972 struct extent_io_tree
*tree
, struct page
*page
,
3975 struct extent_map
*em
;
3976 u64 start
= page_offset(page
);
3977 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3979 if ((mask
& __GFP_WAIT
) &&
3980 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
3982 while (start
<= end
) {
3983 len
= end
- start
+ 1;
3984 write_lock(&map
->lock
);
3985 em
= lookup_extent_mapping(map
, start
, len
);
3987 write_unlock(&map
->lock
);
3990 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
3991 em
->start
!= start
) {
3992 write_unlock(&map
->lock
);
3993 free_extent_map(em
);
3996 if (!test_range_bit(tree
, em
->start
,
3997 extent_map_end(em
) - 1,
3998 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
4000 remove_extent_mapping(map
, em
);
4001 /* once for the rb tree */
4002 free_extent_map(em
);
4004 start
= extent_map_end(em
);
4005 write_unlock(&map
->lock
);
4008 free_extent_map(em
);
4011 return try_release_extent_state(map
, tree
, page
, mask
);
4015 * helper function for fiemap, which doesn't want to see any holes.
4016 * This maps until we find something past 'last'
4018 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
4021 get_extent_t
*get_extent
)
4023 u64 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
4024 struct extent_map
*em
;
4031 len
= last
- offset
;
4034 len
= ALIGN(len
, sectorsize
);
4035 em
= get_extent(inode
, NULL
, 0, offset
, len
, 0);
4036 if (IS_ERR_OR_NULL(em
))
4039 /* if this isn't a hole return it */
4040 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
4041 em
->block_start
!= EXTENT_MAP_HOLE
) {
4045 /* this is a hole, advance to the next extent */
4046 offset
= extent_map_end(em
);
4047 free_extent_map(em
);
4054 static noinline
int count_ext_ref(u64 inum
, u64 offset
, u64 root_id
, void *ctx
)
4056 unsigned long cnt
= *((unsigned long *)ctx
);
4059 *((unsigned long *)ctx
) = cnt
;
4061 /* Now we're sure that the extent is shared. */
4067 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4068 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
4072 u64 max
= start
+ len
;
4076 u64 last_for_get_extent
= 0;
4078 u64 isize
= i_size_read(inode
);
4079 struct btrfs_key found_key
;
4080 struct extent_map
*em
= NULL
;
4081 struct extent_state
*cached_state
= NULL
;
4082 struct btrfs_path
*path
;
4091 path
= btrfs_alloc_path();
4094 path
->leave_spinning
= 1;
4096 start
= ALIGN(start
, BTRFS_I(inode
)->root
->sectorsize
);
4097 len
= ALIGN(len
, BTRFS_I(inode
)->root
->sectorsize
);
4100 * lookup the last file extent. We're not using i_size here
4101 * because there might be preallocation past i_size
4103 ret
= btrfs_lookup_file_extent(NULL
, BTRFS_I(inode
)->root
,
4104 path
, btrfs_ino(inode
), -1, 0);
4106 btrfs_free_path(path
);
4111 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
4112 found_type
= btrfs_key_type(&found_key
);
4114 /* No extents, but there might be delalloc bits */
4115 if (found_key
.objectid
!= btrfs_ino(inode
) ||
4116 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
4117 /* have to trust i_size as the end */
4119 last_for_get_extent
= isize
;
4122 * remember the start of the last extent. There are a
4123 * bunch of different factors that go into the length of the
4124 * extent, so its much less complex to remember where it started
4126 last
= found_key
.offset
;
4127 last_for_get_extent
= last
+ 1;
4129 btrfs_release_path(path
);
4132 * we might have some extents allocated but more delalloc past those
4133 * extents. so, we trust isize unless the start of the last extent is
4138 last_for_get_extent
= isize
;
4141 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1, 0,
4144 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4154 u64 offset_in_extent
= 0;
4156 /* break if the extent we found is outside the range */
4157 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4161 * get_extent may return an extent that starts before our
4162 * requested range. We have to make sure the ranges
4163 * we return to fiemap always move forward and don't
4164 * overlap, so adjust the offsets here
4166 em_start
= max(em
->start
, off
);
4169 * record the offset from the start of the extent
4170 * for adjusting the disk offset below. Only do this if the
4171 * extent isn't compressed since our in ram offset may be past
4172 * what we have actually allocated on disk.
4174 if (!test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4175 offset_in_extent
= em_start
- em
->start
;
4176 em_end
= extent_map_end(em
);
4177 em_len
= em_end
- em_start
;
4182 * bump off for our next call to get_extent
4184 off
= extent_map_end(em
);
4188 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4190 flags
|= FIEMAP_EXTENT_LAST
;
4191 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4192 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4193 FIEMAP_EXTENT_NOT_ALIGNED
);
4194 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4195 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4196 FIEMAP_EXTENT_UNKNOWN
);
4198 unsigned long ref_cnt
= 0;
4200 disko
= em
->block_start
+ offset_in_extent
;
4203 * As btrfs supports shared space, this information
4204 * can be exported to userspace tools via
4205 * flag FIEMAP_EXTENT_SHARED.
4207 ret
= iterate_inodes_from_logical(
4209 BTRFS_I(inode
)->root
->fs_info
,
4210 path
, count_ext_ref
, &ref_cnt
);
4211 if (ret
< 0 && ret
!= -ENOENT
)
4215 flags
|= FIEMAP_EXTENT_SHARED
;
4217 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4218 flags
|= FIEMAP_EXTENT_ENCODED
;
4220 free_extent_map(em
);
4222 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4223 (last
== (u64
)-1 && isize
<= em_end
)) {
4224 flags
|= FIEMAP_EXTENT_LAST
;
4228 /* now scan forward to see if this is really the last extent. */
4229 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4236 flags
|= FIEMAP_EXTENT_LAST
;
4239 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
4245 free_extent_map(em
);
4247 btrfs_free_path(path
);
4248 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4249 &cached_state
, GFP_NOFS
);
4253 static void __free_extent_buffer(struct extent_buffer
*eb
)
4255 btrfs_leak_debug_del(&eb
->leak_list
);
4256 kmem_cache_free(extent_buffer_cache
, eb
);
4259 static int extent_buffer_under_io(struct extent_buffer
*eb
)
4261 return (atomic_read(&eb
->io_pages
) ||
4262 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4263 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4267 * Helper for releasing extent buffer page.
4269 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
,
4270 unsigned long start_idx
)
4272 unsigned long index
;
4273 unsigned long num_pages
;
4275 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4277 BUG_ON(extent_buffer_under_io(eb
));
4279 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4280 index
= start_idx
+ num_pages
;
4281 if (start_idx
>= index
)
4286 page
= extent_buffer_page(eb
, index
);
4287 if (page
&& mapped
) {
4288 spin_lock(&page
->mapping
->private_lock
);
4290 * We do this since we'll remove the pages after we've
4291 * removed the eb from the radix tree, so we could race
4292 * and have this page now attached to the new eb. So
4293 * only clear page_private if it's still connected to
4296 if (PagePrivate(page
) &&
4297 page
->private == (unsigned long)eb
) {
4298 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4299 BUG_ON(PageDirty(page
));
4300 BUG_ON(PageWriteback(page
));
4302 * We need to make sure we haven't be attached
4305 ClearPagePrivate(page
);
4306 set_page_private(page
, 0);
4307 /* One for the page private */
4308 page_cache_release(page
);
4310 spin_unlock(&page
->mapping
->private_lock
);
4314 /* One for when we alloced the page */
4315 page_cache_release(page
);
4317 } while (index
!= start_idx
);
4321 * Helper for releasing the extent buffer.
4323 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4325 btrfs_release_extent_buffer_page(eb
, 0);
4326 __free_extent_buffer(eb
);
4329 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
4334 struct extent_buffer
*eb
= NULL
;
4336 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
4343 rwlock_init(&eb
->lock
);
4344 atomic_set(&eb
->write_locks
, 0);
4345 atomic_set(&eb
->read_locks
, 0);
4346 atomic_set(&eb
->blocking_readers
, 0);
4347 atomic_set(&eb
->blocking_writers
, 0);
4348 atomic_set(&eb
->spinning_readers
, 0);
4349 atomic_set(&eb
->spinning_writers
, 0);
4350 eb
->lock_nested
= 0;
4351 init_waitqueue_head(&eb
->write_lock_wq
);
4352 init_waitqueue_head(&eb
->read_lock_wq
);
4354 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4356 spin_lock_init(&eb
->refs_lock
);
4357 atomic_set(&eb
->refs
, 1);
4358 atomic_set(&eb
->io_pages
, 0);
4361 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4363 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4364 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4365 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4370 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4374 struct extent_buffer
*new;
4375 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4377 new = __alloc_extent_buffer(NULL
, src
->start
, src
->len
, GFP_NOFS
);
4381 for (i
= 0; i
< num_pages
; i
++) {
4382 p
= alloc_page(GFP_NOFS
);
4384 btrfs_release_extent_buffer(new);
4387 attach_extent_buffer_page(new, p
);
4388 WARN_ON(PageDirty(p
));
4393 copy_extent_buffer(new, src
, 0, 0, src
->len
);
4394 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4395 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4400 struct extent_buffer
*alloc_dummy_extent_buffer(u64 start
, unsigned long len
)
4402 struct extent_buffer
*eb
;
4403 unsigned long num_pages
= num_extent_pages(0, len
);
4406 eb
= __alloc_extent_buffer(NULL
, start
, len
, GFP_NOFS
);
4410 for (i
= 0; i
< num_pages
; i
++) {
4411 eb
->pages
[i
] = alloc_page(GFP_NOFS
);
4415 set_extent_buffer_uptodate(eb
);
4416 btrfs_set_header_nritems(eb
, 0);
4417 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4422 __free_page(eb
->pages
[i
- 1]);
4423 __free_extent_buffer(eb
);
4427 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4430 /* the ref bit is tricky. We have to make sure it is set
4431 * if we have the buffer dirty. Otherwise the
4432 * code to free a buffer can end up dropping a dirty
4435 * Once the ref bit is set, it won't go away while the
4436 * buffer is dirty or in writeback, and it also won't
4437 * go away while we have the reference count on the
4440 * We can't just set the ref bit without bumping the
4441 * ref on the eb because free_extent_buffer might
4442 * see the ref bit and try to clear it. If this happens
4443 * free_extent_buffer might end up dropping our original
4444 * ref by mistake and freeing the page before we are able
4445 * to add one more ref.
4447 * So bump the ref count first, then set the bit. If someone
4448 * beat us to it, drop the ref we added.
4450 refs
= atomic_read(&eb
->refs
);
4451 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4454 spin_lock(&eb
->refs_lock
);
4455 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4456 atomic_inc(&eb
->refs
);
4457 spin_unlock(&eb
->refs_lock
);
4460 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
)
4462 unsigned long num_pages
, i
;
4464 check_buffer_tree_ref(eb
);
4466 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4467 for (i
= 0; i
< num_pages
; i
++) {
4468 struct page
*p
= extent_buffer_page(eb
, i
);
4469 mark_page_accessed(p
);
4473 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
4476 struct extent_buffer
*eb
;
4479 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4480 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4482 mark_extent_buffer_accessed(eb
);
4490 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
4491 u64 start
, unsigned long len
)
4493 unsigned long num_pages
= num_extent_pages(start
, len
);
4495 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
4496 struct extent_buffer
*eb
;
4497 struct extent_buffer
*exists
= NULL
;
4499 struct address_space
*mapping
= tree
->mapping
;
4504 eb
= find_extent_buffer(tree
, start
);
4508 eb
= __alloc_extent_buffer(tree
, start
, len
, GFP_NOFS
);
4512 for (i
= 0; i
< num_pages
; i
++, index
++) {
4513 p
= find_or_create_page(mapping
, index
, GFP_NOFS
);
4517 spin_lock(&mapping
->private_lock
);
4518 if (PagePrivate(p
)) {
4520 * We could have already allocated an eb for this page
4521 * and attached one so lets see if we can get a ref on
4522 * the existing eb, and if we can we know it's good and
4523 * we can just return that one, else we know we can just
4524 * overwrite page->private.
4526 exists
= (struct extent_buffer
*)p
->private;
4527 if (atomic_inc_not_zero(&exists
->refs
)) {
4528 spin_unlock(&mapping
->private_lock
);
4530 page_cache_release(p
);
4531 mark_extent_buffer_accessed(exists
);
4536 * Do this so attach doesn't complain and we need to
4537 * drop the ref the old guy had.
4539 ClearPagePrivate(p
);
4540 WARN_ON(PageDirty(p
));
4541 page_cache_release(p
);
4543 attach_extent_buffer_page(eb
, p
);
4544 spin_unlock(&mapping
->private_lock
);
4545 WARN_ON(PageDirty(p
));
4546 mark_page_accessed(p
);
4548 if (!PageUptodate(p
))
4552 * see below about how we avoid a nasty race with release page
4553 * and why we unlock later
4557 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4559 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
4563 spin_lock(&tree
->buffer_lock
);
4564 ret
= radix_tree_insert(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
, eb
);
4565 spin_unlock(&tree
->buffer_lock
);
4566 radix_tree_preload_end();
4567 if (ret
== -EEXIST
) {
4568 exists
= find_extent_buffer(tree
, start
);
4574 /* add one reference for the tree */
4575 check_buffer_tree_ref(eb
);
4578 * there is a race where release page may have
4579 * tried to find this extent buffer in the radix
4580 * but failed. It will tell the VM it is safe to
4581 * reclaim the, and it will clear the page private bit.
4582 * We must make sure to set the page private bit properly
4583 * after the extent buffer is in the radix tree so
4584 * it doesn't get lost
4586 SetPageChecked(eb
->pages
[0]);
4587 for (i
= 1; i
< num_pages
; i
++) {
4588 p
= extent_buffer_page(eb
, i
);
4589 ClearPageChecked(p
);
4592 unlock_page(eb
->pages
[0]);
4596 for (i
= 0; i
< num_pages
; i
++) {
4598 unlock_page(eb
->pages
[i
]);
4601 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
4602 btrfs_release_extent_buffer(eb
);
4606 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
4608 struct extent_buffer
*eb
=
4609 container_of(head
, struct extent_buffer
, rcu_head
);
4611 __free_extent_buffer(eb
);
4614 /* Expects to have eb->eb_lock already held */
4615 static int release_extent_buffer(struct extent_buffer
*eb
)
4617 WARN_ON(atomic_read(&eb
->refs
) == 0);
4618 if (atomic_dec_and_test(&eb
->refs
)) {
4619 if (test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
)) {
4620 spin_unlock(&eb
->refs_lock
);
4622 struct extent_io_tree
*tree
= eb
->tree
;
4624 spin_unlock(&eb
->refs_lock
);
4626 spin_lock(&tree
->buffer_lock
);
4627 radix_tree_delete(&tree
->buffer
,
4628 eb
->start
>> PAGE_CACHE_SHIFT
);
4629 spin_unlock(&tree
->buffer_lock
);
4632 /* Should be safe to release our pages at this point */
4633 btrfs_release_extent_buffer_page(eb
, 0);
4634 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
4637 spin_unlock(&eb
->refs_lock
);
4642 void free_extent_buffer(struct extent_buffer
*eb
)
4650 refs
= atomic_read(&eb
->refs
);
4653 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
4658 spin_lock(&eb
->refs_lock
);
4659 if (atomic_read(&eb
->refs
) == 2 &&
4660 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
4661 atomic_dec(&eb
->refs
);
4663 if (atomic_read(&eb
->refs
) == 2 &&
4664 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
4665 !extent_buffer_under_io(eb
) &&
4666 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4667 atomic_dec(&eb
->refs
);
4670 * I know this is terrible, but it's temporary until we stop tracking
4671 * the uptodate bits and such for the extent buffers.
4673 release_extent_buffer(eb
);
4676 void free_extent_buffer_stale(struct extent_buffer
*eb
)
4681 spin_lock(&eb
->refs_lock
);
4682 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
4684 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
4685 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4686 atomic_dec(&eb
->refs
);
4687 release_extent_buffer(eb
);
4690 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
4693 unsigned long num_pages
;
4696 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4698 for (i
= 0; i
< num_pages
; i
++) {
4699 page
= extent_buffer_page(eb
, i
);
4700 if (!PageDirty(page
))
4704 WARN_ON(!PagePrivate(page
));
4706 clear_page_dirty_for_io(page
);
4707 spin_lock_irq(&page
->mapping
->tree_lock
);
4708 if (!PageDirty(page
)) {
4709 radix_tree_tag_clear(&page
->mapping
->page_tree
,
4711 PAGECACHE_TAG_DIRTY
);
4713 spin_unlock_irq(&page
->mapping
->tree_lock
);
4714 ClearPageError(page
);
4717 WARN_ON(atomic_read(&eb
->refs
) == 0);
4720 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
4723 unsigned long num_pages
;
4726 check_buffer_tree_ref(eb
);
4728 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
4730 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4731 WARN_ON(atomic_read(&eb
->refs
) == 0);
4732 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
4734 for (i
= 0; i
< num_pages
; i
++)
4735 set_page_dirty(extent_buffer_page(eb
, i
));
4739 int clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
4743 unsigned long num_pages
;
4745 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4746 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4747 for (i
= 0; i
< num_pages
; i
++) {
4748 page
= extent_buffer_page(eb
, i
);
4750 ClearPageUptodate(page
);
4755 int set_extent_buffer_uptodate(struct extent_buffer
*eb
)
4759 unsigned long num_pages
;
4761 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4762 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4763 for (i
= 0; i
< num_pages
; i
++) {
4764 page
= extent_buffer_page(eb
, i
);
4765 SetPageUptodate(page
);
4770 int extent_buffer_uptodate(struct extent_buffer
*eb
)
4772 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4775 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
4776 struct extent_buffer
*eb
, u64 start
, int wait
,
4777 get_extent_t
*get_extent
, int mirror_num
)
4780 unsigned long start_i
;
4784 int locked_pages
= 0;
4785 int all_uptodate
= 1;
4786 unsigned long num_pages
;
4787 unsigned long num_reads
= 0;
4788 struct bio
*bio
= NULL
;
4789 unsigned long bio_flags
= 0;
4791 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
4795 WARN_ON(start
< eb
->start
);
4796 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
4797 (eb
->start
>> PAGE_CACHE_SHIFT
);
4802 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4803 for (i
= start_i
; i
< num_pages
; i
++) {
4804 page
= extent_buffer_page(eb
, i
);
4805 if (wait
== WAIT_NONE
) {
4806 if (!trylock_page(page
))
4812 if (!PageUptodate(page
)) {
4819 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4823 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
4824 eb
->read_mirror
= 0;
4825 atomic_set(&eb
->io_pages
, num_reads
);
4826 for (i
= start_i
; i
< num_pages
; i
++) {
4827 page
= extent_buffer_page(eb
, i
);
4828 if (!PageUptodate(page
)) {
4829 ClearPageError(page
);
4830 err
= __extent_read_full_page(tree
, page
,
4832 mirror_num
, &bio_flags
,
4842 err
= submit_one_bio(READ
| REQ_META
, bio
, mirror_num
,
4848 if (ret
|| wait
!= WAIT_COMPLETE
)
4851 for (i
= start_i
; i
< num_pages
; i
++) {
4852 page
= extent_buffer_page(eb
, i
);
4853 wait_on_page_locked(page
);
4854 if (!PageUptodate(page
))
4862 while (locked_pages
> 0) {
4863 page
= extent_buffer_page(eb
, i
);
4871 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
4872 unsigned long start
,
4879 char *dst
= (char *)dstv
;
4880 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4881 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4883 WARN_ON(start
> eb
->len
);
4884 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4886 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4889 page
= extent_buffer_page(eb
, i
);
4891 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4892 kaddr
= page_address(page
);
4893 memcpy(dst
, kaddr
+ offset
, cur
);
4902 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
4903 unsigned long min_len
, char **map
,
4904 unsigned long *map_start
,
4905 unsigned long *map_len
)
4907 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
4910 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4911 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4912 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
4919 offset
= start_offset
;
4923 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
4926 if (start
+ min_len
> eb
->len
) {
4927 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
4929 eb
->start
, eb
->len
, start
, min_len
);
4933 p
= extent_buffer_page(eb
, i
);
4934 kaddr
= page_address(p
);
4935 *map
= kaddr
+ offset
;
4936 *map_len
= PAGE_CACHE_SIZE
- offset
;
4940 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
4941 unsigned long start
,
4948 char *ptr
= (char *)ptrv
;
4949 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4950 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4953 WARN_ON(start
> eb
->len
);
4954 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4956 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4959 page
= extent_buffer_page(eb
, i
);
4961 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4963 kaddr
= page_address(page
);
4964 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
4976 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
4977 unsigned long start
, unsigned long len
)
4983 char *src
= (char *)srcv
;
4984 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4985 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4987 WARN_ON(start
> eb
->len
);
4988 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4990 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4993 page
= extent_buffer_page(eb
, i
);
4994 WARN_ON(!PageUptodate(page
));
4996 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
4997 kaddr
= page_address(page
);
4998 memcpy(kaddr
+ offset
, src
, cur
);
5007 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
5008 unsigned long start
, unsigned long len
)
5014 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5015 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5017 WARN_ON(start
> eb
->len
);
5018 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5020 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5023 page
= extent_buffer_page(eb
, i
);
5024 WARN_ON(!PageUptodate(page
));
5026 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
5027 kaddr
= page_address(page
);
5028 memset(kaddr
+ offset
, c
, cur
);
5036 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
5037 unsigned long dst_offset
, unsigned long src_offset
,
5040 u64 dst_len
= dst
->len
;
5045 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5046 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5048 WARN_ON(src
->len
!= dst_len
);
5050 offset
= (start_offset
+ dst_offset
) &
5051 (PAGE_CACHE_SIZE
- 1);
5054 page
= extent_buffer_page(dst
, i
);
5055 WARN_ON(!PageUptodate(page
));
5057 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
5059 kaddr
= page_address(page
);
5060 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
5069 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
5071 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
5072 return distance
< len
;
5075 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
5076 unsigned long dst_off
, unsigned long src_off
,
5079 char *dst_kaddr
= page_address(dst_page
);
5081 int must_memmove
= 0;
5083 if (dst_page
!= src_page
) {
5084 src_kaddr
= page_address(src_page
);
5086 src_kaddr
= dst_kaddr
;
5087 if (areas_overlap(src_off
, dst_off
, len
))
5092 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5094 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5097 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5098 unsigned long src_offset
, unsigned long len
)
5101 size_t dst_off_in_page
;
5102 size_t src_off_in_page
;
5103 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5104 unsigned long dst_i
;
5105 unsigned long src_i
;
5107 if (src_offset
+ len
> dst
->len
) {
5108 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5109 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
5112 if (dst_offset
+ len
> dst
->len
) {
5113 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5114 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
5119 dst_off_in_page
= (start_offset
+ dst_offset
) &
5120 (PAGE_CACHE_SIZE
- 1);
5121 src_off_in_page
= (start_offset
+ src_offset
) &
5122 (PAGE_CACHE_SIZE
- 1);
5124 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5125 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
5127 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
5129 cur
= min_t(unsigned long, cur
,
5130 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
5132 copy_pages(extent_buffer_page(dst
, dst_i
),
5133 extent_buffer_page(dst
, src_i
),
5134 dst_off_in_page
, src_off_in_page
, cur
);
5142 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5143 unsigned long src_offset
, unsigned long len
)
5146 size_t dst_off_in_page
;
5147 size_t src_off_in_page
;
5148 unsigned long dst_end
= dst_offset
+ len
- 1;
5149 unsigned long src_end
= src_offset
+ len
- 1;
5150 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5151 unsigned long dst_i
;
5152 unsigned long src_i
;
5154 if (src_offset
+ len
> dst
->len
) {
5155 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5156 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
5159 if (dst_offset
+ len
> dst
->len
) {
5160 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5161 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
5164 if (dst_offset
< src_offset
) {
5165 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5169 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
5170 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
5172 dst_off_in_page
= (start_offset
+ dst_end
) &
5173 (PAGE_CACHE_SIZE
- 1);
5174 src_off_in_page
= (start_offset
+ src_end
) &
5175 (PAGE_CACHE_SIZE
- 1);
5177 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5178 cur
= min(cur
, dst_off_in_page
+ 1);
5179 copy_pages(extent_buffer_page(dst
, dst_i
),
5180 extent_buffer_page(dst
, src_i
),
5181 dst_off_in_page
- cur
+ 1,
5182 src_off_in_page
- cur
+ 1, cur
);
5190 int try_release_extent_buffer(struct page
*page
)
5192 struct extent_buffer
*eb
;
5195 * We need to make sure noboody is attaching this page to an eb right
5198 spin_lock(&page
->mapping
->private_lock
);
5199 if (!PagePrivate(page
)) {
5200 spin_unlock(&page
->mapping
->private_lock
);
5204 eb
= (struct extent_buffer
*)page
->private;
5208 * This is a little awful but should be ok, we need to make sure that
5209 * the eb doesn't disappear out from under us while we're looking at
5212 spin_lock(&eb
->refs_lock
);
5213 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
5214 spin_unlock(&eb
->refs_lock
);
5215 spin_unlock(&page
->mapping
->private_lock
);
5218 spin_unlock(&page
->mapping
->private_lock
);
5221 * If tree ref isn't set then we know the ref on this eb is a real ref,
5222 * so just return, this page will likely be freed soon anyway.
5224 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
5225 spin_unlock(&eb
->refs_lock
);
5229 return release_extent_buffer(eb
);