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
);
1955 static void repair_io_failure_callback(struct bio
*bio
, int err
)
1957 complete(bio
->bi_private
);
1961 * this bypasses the standard btrfs submit functions deliberately, as
1962 * the standard behavior is to write all copies in a raid setup. here we only
1963 * want to write the one bad copy. so we do the mapping for ourselves and issue
1964 * submit_bio directly.
1965 * to avoid any synchronization issues, wait for the data after writing, which
1966 * actually prevents the read that triggered the error from finishing.
1967 * currently, there can be no more than two copies of every data bit. thus,
1968 * exactly one rewrite is required.
1970 int repair_io_failure(struct btrfs_fs_info
*fs_info
, u64 start
,
1971 u64 length
, u64 logical
, struct page
*page
,
1975 struct btrfs_device
*dev
;
1976 DECLARE_COMPLETION_ONSTACK(compl);
1979 struct btrfs_bio
*bbio
= NULL
;
1980 struct btrfs_mapping_tree
*map_tree
= &fs_info
->mapping_tree
;
1983 BUG_ON(!mirror_num
);
1985 /* we can't repair anything in raid56 yet */
1986 if (btrfs_is_parity_mirror(map_tree
, logical
, length
, mirror_num
))
1989 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
1992 bio
->bi_private
= &compl;
1993 bio
->bi_end_io
= repair_io_failure_callback
;
1995 map_length
= length
;
1997 ret
= btrfs_map_block(fs_info
, WRITE
, logical
,
1998 &map_length
, &bbio
, mirror_num
);
2003 BUG_ON(mirror_num
!= bbio
->mirror_num
);
2004 sector
= bbio
->stripes
[mirror_num
-1].physical
>> 9;
2005 bio
->bi_sector
= sector
;
2006 dev
= bbio
->stripes
[mirror_num
-1].dev
;
2008 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2012 bio
->bi_bdev
= dev
->bdev
;
2013 bio_add_page(bio
, page
, length
, start
- page_offset(page
));
2014 btrfsic_submit_bio(WRITE_SYNC
, bio
);
2015 wait_for_completion(&compl);
2017 if (!test_bit(BIO_UPTODATE
, &bio
->bi_flags
)) {
2018 /* try to remap that extent elsewhere? */
2020 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2024 printk_ratelimited_in_rcu(KERN_INFO
"btrfs read error corrected: ino %lu off %llu "
2025 "(dev %s sector %llu)\n", page
->mapping
->host
->i_ino
,
2026 start
, rcu_str_deref(dev
->name
), sector
);
2032 int repair_eb_io_failure(struct btrfs_root
*root
, struct extent_buffer
*eb
,
2035 u64 start
= eb
->start
;
2036 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2039 for (i
= 0; i
< num_pages
; i
++) {
2040 struct page
*p
= extent_buffer_page(eb
, i
);
2041 ret
= repair_io_failure(root
->fs_info
, start
, PAGE_CACHE_SIZE
,
2042 start
, p
, mirror_num
);
2045 start
+= PAGE_CACHE_SIZE
;
2052 * each time an IO finishes, we do a fast check in the IO failure tree
2053 * to see if we need to process or clean up an io_failure_record
2055 static int clean_io_failure(u64 start
, struct page
*page
)
2058 u64 private_failure
;
2059 struct io_failure_record
*failrec
;
2060 struct btrfs_fs_info
*fs_info
;
2061 struct extent_state
*state
;
2065 struct inode
*inode
= page
->mapping
->host
;
2068 ret
= count_range_bits(&BTRFS_I(inode
)->io_failure_tree
, &private,
2069 (u64
)-1, 1, EXTENT_DIRTY
, 0);
2073 ret
= get_state_private(&BTRFS_I(inode
)->io_failure_tree
, start
,
2078 failrec
= (struct io_failure_record
*)(unsigned long) private_failure
;
2079 BUG_ON(!failrec
->this_mirror
);
2081 if (failrec
->in_validation
) {
2082 /* there was no real error, just free the record */
2083 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2089 spin_lock(&BTRFS_I(inode
)->io_tree
.lock
);
2090 state
= find_first_extent_bit_state(&BTRFS_I(inode
)->io_tree
,
2093 spin_unlock(&BTRFS_I(inode
)->io_tree
.lock
);
2095 if (state
&& state
->start
<= failrec
->start
&&
2096 state
->end
>= failrec
->start
+ failrec
->len
- 1) {
2097 fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2098 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2100 if (num_copies
> 1) {
2101 ret
= repair_io_failure(fs_info
, start
, failrec
->len
,
2102 failrec
->logical
, page
,
2103 failrec
->failed_mirror
);
2111 ret
= free_io_failure(inode
, failrec
, did_repair
);
2117 * this is a generic handler for readpage errors (default
2118 * readpage_io_failed_hook). if other copies exist, read those and write back
2119 * good data to the failed position. does not investigate in remapping the
2120 * failed extent elsewhere, hoping the device will be smart enough to do this as
2124 static int bio_readpage_error(struct bio
*failed_bio
, u64 phy_offset
,
2125 struct page
*page
, u64 start
, u64 end
,
2128 struct io_failure_record
*failrec
= NULL
;
2130 struct extent_map
*em
;
2131 struct inode
*inode
= page
->mapping
->host
;
2132 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2133 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2134 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2136 struct btrfs_io_bio
*btrfs_failed_bio
;
2137 struct btrfs_io_bio
*btrfs_bio
;
2143 BUG_ON(failed_bio
->bi_rw
& REQ_WRITE
);
2145 ret
= get_state_private(failure_tree
, start
, &private);
2147 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2150 failrec
->start
= start
;
2151 failrec
->len
= end
- start
+ 1;
2152 failrec
->this_mirror
= 0;
2153 failrec
->bio_flags
= 0;
2154 failrec
->in_validation
= 0;
2156 read_lock(&em_tree
->lock
);
2157 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2159 read_unlock(&em_tree
->lock
);
2164 if (em
->start
> start
|| em
->start
+ em
->len
< start
) {
2165 free_extent_map(em
);
2168 read_unlock(&em_tree
->lock
);
2174 logical
= start
- em
->start
;
2175 logical
= em
->block_start
+ logical
;
2176 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2177 logical
= em
->block_start
;
2178 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2179 extent_set_compress_type(&failrec
->bio_flags
,
2182 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2183 "len=%llu\n", logical
, start
, failrec
->len
);
2184 failrec
->logical
= logical
;
2185 free_extent_map(em
);
2187 /* set the bits in the private failure tree */
2188 ret
= set_extent_bits(failure_tree
, start
, end
,
2189 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
2191 ret
= set_state_private(failure_tree
, start
,
2192 (u64
)(unsigned long)failrec
);
2193 /* set the bits in the inode's tree */
2195 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
,
2202 failrec
= (struct io_failure_record
*)(unsigned long)private;
2203 pr_debug("bio_readpage_error: (found) logical=%llu, "
2204 "start=%llu, len=%llu, validation=%d\n",
2205 failrec
->logical
, failrec
->start
, failrec
->len
,
2206 failrec
->in_validation
);
2208 * when data can be on disk more than twice, add to failrec here
2209 * (e.g. with a list for failed_mirror) to make
2210 * clean_io_failure() clean all those errors at once.
2213 num_copies
= btrfs_num_copies(BTRFS_I(inode
)->root
->fs_info
,
2214 failrec
->logical
, failrec
->len
);
2215 if (num_copies
== 1) {
2217 * we only have a single copy of the data, so don't bother with
2218 * all the retry and error correction code that follows. no
2219 * matter what the error is, it is very likely to persist.
2221 pr_debug("bio_readpage_error: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
2222 num_copies
, failrec
->this_mirror
, failed_mirror
);
2223 free_io_failure(inode
, failrec
, 0);
2228 * there are two premises:
2229 * a) deliver good data to the caller
2230 * b) correct the bad sectors on disk
2232 if (failed_bio
->bi_vcnt
> 1) {
2234 * to fulfill b), we need to know the exact failing sectors, as
2235 * we don't want to rewrite any more than the failed ones. thus,
2236 * we need separate read requests for the failed bio
2238 * if the following BUG_ON triggers, our validation request got
2239 * merged. we need separate requests for our algorithm to work.
2241 BUG_ON(failrec
->in_validation
);
2242 failrec
->in_validation
= 1;
2243 failrec
->this_mirror
= failed_mirror
;
2244 read_mode
= READ_SYNC
| REQ_FAILFAST_DEV
;
2247 * we're ready to fulfill a) and b) alongside. get a good copy
2248 * of the failed sector and if we succeed, we have setup
2249 * everything for repair_io_failure to do the rest for us.
2251 if (failrec
->in_validation
) {
2252 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2253 failrec
->in_validation
= 0;
2254 failrec
->this_mirror
= 0;
2256 failrec
->failed_mirror
= failed_mirror
;
2257 failrec
->this_mirror
++;
2258 if (failrec
->this_mirror
== failed_mirror
)
2259 failrec
->this_mirror
++;
2260 read_mode
= READ_SYNC
;
2263 if (failrec
->this_mirror
> num_copies
) {
2264 pr_debug("bio_readpage_error: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
2265 num_copies
, failrec
->this_mirror
, failed_mirror
);
2266 free_io_failure(inode
, failrec
, 0);
2270 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2272 free_io_failure(inode
, failrec
, 0);
2275 bio
->bi_end_io
= failed_bio
->bi_end_io
;
2276 bio
->bi_sector
= failrec
->logical
>> 9;
2277 bio
->bi_bdev
= BTRFS_I(inode
)->root
->fs_info
->fs_devices
->latest_bdev
;
2280 btrfs_failed_bio
= btrfs_io_bio(failed_bio
);
2281 if (btrfs_failed_bio
->csum
) {
2282 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2283 u16 csum_size
= btrfs_super_csum_size(fs_info
->super_copy
);
2285 btrfs_bio
= btrfs_io_bio(bio
);
2286 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
2287 phy_offset
>>= inode
->i_sb
->s_blocksize_bits
;
2288 phy_offset
*= csum_size
;
2289 memcpy(btrfs_bio
->csum
, btrfs_failed_bio
->csum
+ phy_offset
,
2293 bio_add_page(bio
, page
, failrec
->len
, start
- page_offset(page
));
2295 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2296 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode
,
2297 failrec
->this_mirror
, num_copies
, failrec
->in_validation
);
2299 ret
= tree
->ops
->submit_bio_hook(inode
, read_mode
, bio
,
2300 failrec
->this_mirror
,
2301 failrec
->bio_flags
, 0);
2305 /* lots and lots of room for performance fixes in the end_bio funcs */
2307 int end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2309 int uptodate
= (err
== 0);
2310 struct extent_io_tree
*tree
;
2313 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2315 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
2316 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
2317 end
, NULL
, uptodate
);
2323 ClearPageUptodate(page
);
2330 * after a writepage IO is done, we need to:
2331 * clear the uptodate bits on error
2332 * clear the writeback bits in the extent tree for this IO
2333 * end_page_writeback if the page has no more pending IO
2335 * Scheduling is not allowed, so the extent state tree is expected
2336 * to have one and only one object corresponding to this IO.
2338 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
2340 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2341 struct extent_io_tree
*tree
;
2346 struct page
*page
= bvec
->bv_page
;
2347 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2349 /* We always issue full-page reads, but if some block
2350 * in a page fails to read, blk_update_request() will
2351 * advance bv_offset and adjust bv_len to compensate.
2352 * Print a warning for nonzero offsets, and an error
2353 * if they don't add up to a full page. */
2354 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2355 printk("%s page write in btrfs with offset %u and length %u\n",
2356 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2357 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2358 bvec
->bv_offset
, bvec
->bv_len
);
2360 start
= page_offset(page
);
2361 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2363 if (--bvec
>= bio
->bi_io_vec
)
2364 prefetchw(&bvec
->bv_page
->flags
);
2366 if (end_extent_writepage(page
, err
, start
, end
))
2369 end_page_writeback(page
);
2370 } while (bvec
>= bio
->bi_io_vec
);
2376 endio_readpage_release_extent(struct extent_io_tree
*tree
, u64 start
, u64 len
,
2379 struct extent_state
*cached
= NULL
;
2380 u64 end
= start
+ len
- 1;
2382 if (uptodate
&& tree
->track_uptodate
)
2383 set_extent_uptodate(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2384 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2388 * after a readpage IO is done, we need to:
2389 * clear the uptodate bits on error
2390 * set the uptodate bits if things worked
2391 * set the page up to date if all extents in the tree are uptodate
2392 * clear the lock bit in the extent tree
2393 * unlock the page if there are no other extents locked for it
2395 * Scheduling is not allowed, so the extent state tree is expected
2396 * to have one and only one object corresponding to this IO.
2398 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
2400 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2401 struct bio_vec
*bvec_end
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2402 struct bio_vec
*bvec
= bio
->bi_io_vec
;
2403 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2404 struct extent_io_tree
*tree
;
2409 u64 extent_start
= 0;
2418 struct page
*page
= bvec
->bv_page
;
2419 struct inode
*inode
= page
->mapping
->host
;
2421 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2422 "mirror=%lu\n", (u64
)bio
->bi_sector
, err
,
2423 io_bio
->mirror_num
);
2424 tree
= &BTRFS_I(inode
)->io_tree
;
2426 /* We always issue full-page reads, but if some block
2427 * in a page fails to read, blk_update_request() will
2428 * advance bv_offset and adjust bv_len to compensate.
2429 * Print a warning for nonzero offsets, and an error
2430 * if they don't add up to a full page. */
2431 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2432 printk("%s page read in btrfs with offset %u and length %u\n",
2433 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2434 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2435 bvec
->bv_offset
, bvec
->bv_len
);
2437 start
= page_offset(page
);
2438 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2441 if (++bvec
<= bvec_end
)
2442 prefetchw(&bvec
->bv_page
->flags
);
2444 mirror
= io_bio
->mirror_num
;
2445 if (likely(uptodate
&& tree
->ops
&&
2446 tree
->ops
->readpage_end_io_hook
)) {
2447 ret
= tree
->ops
->readpage_end_io_hook(io_bio
, offset
,
2453 clean_io_failure(start
, page
);
2456 if (likely(uptodate
))
2459 if (tree
->ops
&& tree
->ops
->readpage_io_failed_hook
) {
2460 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2462 test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
2466 * The generic bio_readpage_error handles errors the
2467 * following way: If possible, new read requests are
2468 * created and submitted and will end up in
2469 * end_bio_extent_readpage as well (if we're lucky, not
2470 * in the !uptodate case). In that case it returns 0 and
2471 * we just go on with the next page in our bio. If it
2472 * can't handle the error it will return -EIO and we
2473 * remain responsible for that page.
2475 ret
= bio_readpage_error(bio
, offset
, page
, start
, end
,
2479 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2486 if (likely(uptodate
)) {
2487 loff_t i_size
= i_size_read(inode
);
2488 pgoff_t end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2491 /* Zero out the end if this page straddles i_size */
2492 offset
= i_size
& (PAGE_CACHE_SIZE
-1);
2493 if (page
->index
== end_index
&& offset
)
2494 zero_user_segment(page
, offset
, PAGE_CACHE_SIZE
);
2495 SetPageUptodate(page
);
2497 ClearPageUptodate(page
);
2503 if (unlikely(!uptodate
)) {
2505 endio_readpage_release_extent(tree
,
2511 endio_readpage_release_extent(tree
, start
,
2512 end
- start
+ 1, 0);
2513 } else if (!extent_len
) {
2514 extent_start
= start
;
2515 extent_len
= end
+ 1 - start
;
2516 } else if (extent_start
+ extent_len
== start
) {
2517 extent_len
+= end
+ 1 - start
;
2519 endio_readpage_release_extent(tree
, extent_start
,
2520 extent_len
, uptodate
);
2521 extent_start
= start
;
2522 extent_len
= end
+ 1 - start
;
2524 } while (bvec
<= bvec_end
);
2527 endio_readpage_release_extent(tree
, extent_start
, extent_len
,
2530 io_bio
->end_io(io_bio
, err
);
2535 * this allocates from the btrfs_bioset. We're returning a bio right now
2536 * but you can call btrfs_io_bio for the appropriate container_of magic
2539 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
2542 struct btrfs_io_bio
*btrfs_bio
;
2545 bio
= bio_alloc_bioset(gfp_flags
, nr_vecs
, btrfs_bioset
);
2547 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
2548 while (!bio
&& (nr_vecs
/= 2)) {
2549 bio
= bio_alloc_bioset(gfp_flags
,
2550 nr_vecs
, btrfs_bioset
);
2556 bio
->bi_bdev
= bdev
;
2557 bio
->bi_sector
= first_sector
;
2558 btrfs_bio
= btrfs_io_bio(bio
);
2559 btrfs_bio
->csum
= NULL
;
2560 btrfs_bio
->csum_allocated
= NULL
;
2561 btrfs_bio
->end_io
= NULL
;
2566 struct bio
*btrfs_bio_clone(struct bio
*bio
, gfp_t gfp_mask
)
2568 return bio_clone_bioset(bio
, gfp_mask
, btrfs_bioset
);
2572 /* this also allocates from the btrfs_bioset */
2573 struct bio
*btrfs_io_bio_alloc(gfp_t gfp_mask
, unsigned int nr_iovecs
)
2575 struct btrfs_io_bio
*btrfs_bio
;
2578 bio
= bio_alloc_bioset(gfp_mask
, nr_iovecs
, btrfs_bioset
);
2580 btrfs_bio
= btrfs_io_bio(bio
);
2581 btrfs_bio
->csum
= NULL
;
2582 btrfs_bio
->csum_allocated
= NULL
;
2583 btrfs_bio
->end_io
= NULL
;
2589 static int __must_check
submit_one_bio(int rw
, struct bio
*bio
,
2590 int mirror_num
, unsigned long bio_flags
)
2593 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2594 struct page
*page
= bvec
->bv_page
;
2595 struct extent_io_tree
*tree
= bio
->bi_private
;
2598 start
= page_offset(page
) + bvec
->bv_offset
;
2600 bio
->bi_private
= NULL
;
2604 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
2605 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
2606 mirror_num
, bio_flags
, start
);
2608 btrfsic_submit_bio(rw
, bio
);
2610 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
2616 static int merge_bio(int rw
, struct extent_io_tree
*tree
, struct page
*page
,
2617 unsigned long offset
, size_t size
, struct bio
*bio
,
2618 unsigned long bio_flags
)
2621 if (tree
->ops
&& tree
->ops
->merge_bio_hook
)
2622 ret
= tree
->ops
->merge_bio_hook(rw
, page
, offset
, size
, bio
,
2629 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
2630 struct page
*page
, sector_t sector
,
2631 size_t size
, unsigned long offset
,
2632 struct block_device
*bdev
,
2633 struct bio
**bio_ret
,
2634 unsigned long max_pages
,
2635 bio_end_io_t end_io_func
,
2637 unsigned long prev_bio_flags
,
2638 unsigned long bio_flags
)
2644 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
2645 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2646 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
2648 if (bio_ret
&& *bio_ret
) {
2651 contig
= bio
->bi_sector
== sector
;
2653 contig
= bio_end_sector(bio
) == sector
;
2655 if (prev_bio_flags
!= bio_flags
|| !contig
||
2656 merge_bio(rw
, tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2657 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2658 ret
= submit_one_bio(rw
, bio
, mirror_num
,
2667 if (this_compressed
)
2670 nr
= bio_get_nr_vecs(bdev
);
2672 bio
= btrfs_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
2676 bio_add_page(bio
, page
, page_size
, offset
);
2677 bio
->bi_end_io
= end_io_func
;
2678 bio
->bi_private
= tree
;
2683 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
2688 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2691 if (!PagePrivate(page
)) {
2692 SetPagePrivate(page
);
2693 page_cache_get(page
);
2694 set_page_private(page
, (unsigned long)eb
);
2696 WARN_ON(page
->private != (unsigned long)eb
);
2700 void set_page_extent_mapped(struct page
*page
)
2702 if (!PagePrivate(page
)) {
2703 SetPagePrivate(page
);
2704 page_cache_get(page
);
2705 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2709 static struct extent_map
*
2710 __get_extent_map(struct inode
*inode
, struct page
*page
, size_t pg_offset
,
2711 u64 start
, u64 len
, get_extent_t
*get_extent
,
2712 struct extent_map
**em_cached
)
2714 struct extent_map
*em
;
2716 if (em_cached
&& *em_cached
) {
2718 if (em
->in_tree
&& start
>= em
->start
&&
2719 start
< extent_map_end(em
)) {
2720 atomic_inc(&em
->refs
);
2724 free_extent_map(em
);
2728 em
= get_extent(inode
, page
, pg_offset
, start
, len
, 0);
2729 if (em_cached
&& !IS_ERR_OR_NULL(em
)) {
2731 atomic_inc(&em
->refs
);
2737 * basic readpage implementation. Locked extent state structs are inserted
2738 * into the tree that are removed when the IO is done (by the end_io
2740 * XXX JDM: This needs looking at to ensure proper page locking
2742 static int __do_readpage(struct extent_io_tree
*tree
,
2744 get_extent_t
*get_extent
,
2745 struct extent_map
**em_cached
,
2746 struct bio
**bio
, int mirror_num
,
2747 unsigned long *bio_flags
, int rw
)
2749 struct inode
*inode
= page
->mapping
->host
;
2750 u64 start
= page_offset(page
);
2751 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2755 u64 last_byte
= i_size_read(inode
);
2759 struct extent_map
*em
;
2760 struct block_device
*bdev
;
2763 int parent_locked
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2764 size_t pg_offset
= 0;
2766 size_t disk_io_size
;
2767 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2768 unsigned long this_bio_flag
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2770 set_page_extent_mapped(page
);
2773 if (!PageUptodate(page
)) {
2774 if (cleancache_get_page(page
) == 0) {
2775 BUG_ON(blocksize
!= PAGE_SIZE
);
2776 unlock_extent(tree
, start
, end
);
2781 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
2783 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
2786 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
2787 userpage
= kmap_atomic(page
);
2788 memset(userpage
+ zero_offset
, 0, iosize
);
2789 flush_dcache_page(page
);
2790 kunmap_atomic(userpage
);
2793 while (cur
<= end
) {
2794 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2796 if (cur
>= last_byte
) {
2798 struct extent_state
*cached
= NULL
;
2800 iosize
= PAGE_CACHE_SIZE
- pg_offset
;
2801 userpage
= kmap_atomic(page
);
2802 memset(userpage
+ pg_offset
, 0, iosize
);
2803 flush_dcache_page(page
);
2804 kunmap_atomic(userpage
);
2805 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2808 unlock_extent_cached(tree
, cur
,
2813 em
= __get_extent_map(inode
, page
, pg_offset
, cur
,
2814 end
- cur
+ 1, get_extent
, em_cached
);
2815 if (IS_ERR_OR_NULL(em
)) {
2818 unlock_extent(tree
, cur
, end
);
2821 extent_offset
= cur
- em
->start
;
2822 BUG_ON(extent_map_end(em
) <= cur
);
2825 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2826 this_bio_flag
|= EXTENT_BIO_COMPRESSED
;
2827 extent_set_compress_type(&this_bio_flag
,
2831 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2832 cur_end
= min(extent_map_end(em
) - 1, end
);
2833 iosize
= ALIGN(iosize
, blocksize
);
2834 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2835 disk_io_size
= em
->block_len
;
2836 sector
= em
->block_start
>> 9;
2838 sector
= (em
->block_start
+ extent_offset
) >> 9;
2839 disk_io_size
= iosize
;
2842 block_start
= em
->block_start
;
2843 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2844 block_start
= EXTENT_MAP_HOLE
;
2845 free_extent_map(em
);
2848 /* we've found a hole, just zero and go on */
2849 if (block_start
== EXTENT_MAP_HOLE
) {
2851 struct extent_state
*cached
= NULL
;
2853 userpage
= kmap_atomic(page
);
2854 memset(userpage
+ pg_offset
, 0, iosize
);
2855 flush_dcache_page(page
);
2856 kunmap_atomic(userpage
);
2858 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2860 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2863 pg_offset
+= iosize
;
2866 /* the get_extent function already copied into the page */
2867 if (test_range_bit(tree
, cur
, cur_end
,
2868 EXTENT_UPTODATE
, 1, NULL
)) {
2869 check_page_uptodate(tree
, page
);
2871 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2873 pg_offset
+= iosize
;
2876 /* we have an inline extent but it didn't get marked up
2877 * to date. Error out
2879 if (block_start
== EXTENT_MAP_INLINE
) {
2882 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2884 pg_offset
+= iosize
;
2889 ret
= submit_extent_page(rw
, tree
, page
,
2890 sector
, disk_io_size
, pg_offset
,
2892 end_bio_extent_readpage
, mirror_num
,
2897 *bio_flags
= this_bio_flag
;
2901 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2904 pg_offset
+= iosize
;
2908 if (!PageError(page
))
2909 SetPageUptodate(page
);
2915 static inline void __do_contiguous_readpages(struct extent_io_tree
*tree
,
2916 struct page
*pages
[], int nr_pages
,
2918 get_extent_t
*get_extent
,
2919 struct extent_map
**em_cached
,
2920 struct bio
**bio
, int mirror_num
,
2921 unsigned long *bio_flags
, int rw
)
2923 struct inode
*inode
;
2924 struct btrfs_ordered_extent
*ordered
;
2927 inode
= pages
[0]->mapping
->host
;
2929 lock_extent(tree
, start
, end
);
2930 ordered
= btrfs_lookup_ordered_range(inode
, start
,
2934 unlock_extent(tree
, start
, end
);
2935 btrfs_start_ordered_extent(inode
, ordered
, 1);
2936 btrfs_put_ordered_extent(ordered
);
2939 for (index
= 0; index
< nr_pages
; index
++) {
2940 __do_readpage(tree
, pages
[index
], get_extent
, em_cached
, bio
,
2941 mirror_num
, bio_flags
, rw
);
2942 page_cache_release(pages
[index
]);
2946 static void __extent_readpages(struct extent_io_tree
*tree
,
2947 struct page
*pages
[],
2948 int nr_pages
, get_extent_t
*get_extent
,
2949 struct extent_map
**em_cached
,
2950 struct bio
**bio
, int mirror_num
,
2951 unsigned long *bio_flags
, int rw
)
2957 int first_index
= 0;
2959 for (index
= 0; index
< nr_pages
; index
++) {
2960 page_start
= page_offset(pages
[index
]);
2963 end
= start
+ PAGE_CACHE_SIZE
- 1;
2964 first_index
= index
;
2965 } else if (end
+ 1 == page_start
) {
2966 end
+= PAGE_CACHE_SIZE
;
2968 __do_contiguous_readpages(tree
, &pages
[first_index
],
2969 index
- first_index
, start
,
2970 end
, get_extent
, em_cached
,
2971 bio
, mirror_num
, bio_flags
,
2974 end
= start
+ PAGE_CACHE_SIZE
- 1;
2975 first_index
= index
;
2980 __do_contiguous_readpages(tree
, &pages
[first_index
],
2981 index
- first_index
, start
,
2982 end
, get_extent
, em_cached
, bio
,
2983 mirror_num
, bio_flags
, rw
);
2986 static int __extent_read_full_page(struct extent_io_tree
*tree
,
2988 get_extent_t
*get_extent
,
2989 struct bio
**bio
, int mirror_num
,
2990 unsigned long *bio_flags
, int rw
)
2992 struct inode
*inode
= page
->mapping
->host
;
2993 struct btrfs_ordered_extent
*ordered
;
2994 u64 start
= page_offset(page
);
2995 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2999 lock_extent(tree
, start
, end
);
3000 ordered
= btrfs_lookup_ordered_extent(inode
, start
);
3003 unlock_extent(tree
, start
, end
);
3004 btrfs_start_ordered_extent(inode
, ordered
, 1);
3005 btrfs_put_ordered_extent(ordered
);
3008 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, bio
, mirror_num
,
3013 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3014 get_extent_t
*get_extent
, int mirror_num
)
3016 struct bio
*bio
= NULL
;
3017 unsigned long bio_flags
= 0;
3020 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
3023 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3027 int extent_read_full_page_nolock(struct extent_io_tree
*tree
, struct page
*page
,
3028 get_extent_t
*get_extent
, int mirror_num
)
3030 struct bio
*bio
= NULL
;
3031 unsigned long bio_flags
= EXTENT_BIO_PARENT_LOCKED
;
3034 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, &bio
, mirror_num
,
3037 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3041 static noinline
void update_nr_written(struct page
*page
,
3042 struct writeback_control
*wbc
,
3043 unsigned long nr_written
)
3045 wbc
->nr_to_write
-= nr_written
;
3046 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
3047 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
3048 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
3052 * the writepage semantics are similar to regular writepage. extent
3053 * records are inserted to lock ranges in the tree, and as dirty areas
3054 * are found, they are marked writeback. Then the lock bits are removed
3055 * and the end_io handler clears the writeback ranges
3057 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
3060 struct inode
*inode
= page
->mapping
->host
;
3061 struct extent_page_data
*epd
= data
;
3062 struct extent_io_tree
*tree
= epd
->tree
;
3063 u64 start
= page_offset(page
);
3065 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
3069 u64 last_byte
= i_size_read(inode
);
3073 struct extent_state
*cached_state
= NULL
;
3074 struct extent_map
*em
;
3075 struct block_device
*bdev
;
3078 size_t pg_offset
= 0;
3080 loff_t i_size
= i_size_read(inode
);
3081 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
3087 unsigned long nr_written
= 0;
3088 bool fill_delalloc
= true;
3090 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3091 write_flags
= WRITE_SYNC
;
3093 write_flags
= WRITE
;
3095 trace___extent_writepage(page
, inode
, wbc
);
3097 WARN_ON(!PageLocked(page
));
3099 ClearPageError(page
);
3101 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
3102 if (page
->index
> end_index
||
3103 (page
->index
== end_index
&& !pg_offset
)) {
3104 page
->mapping
->a_ops
->invalidatepage(page
, 0, PAGE_CACHE_SIZE
);
3109 if (page
->index
== end_index
) {
3112 userpage
= kmap_atomic(page
);
3113 memset(userpage
+ pg_offset
, 0,
3114 PAGE_CACHE_SIZE
- pg_offset
);
3115 kunmap_atomic(userpage
);
3116 flush_dcache_page(page
);
3120 set_page_extent_mapped(page
);
3122 if (!tree
->ops
|| !tree
->ops
->fill_delalloc
)
3123 fill_delalloc
= false;
3125 delalloc_start
= start
;
3128 if (!epd
->extent_locked
&& fill_delalloc
) {
3129 u64 delalloc_to_write
= 0;
3131 * make sure the wbc mapping index is at least updated
3134 update_nr_written(page
, wbc
, 0);
3136 while (delalloc_end
< page_end
) {
3137 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
3142 if (nr_delalloc
== 0) {
3143 delalloc_start
= delalloc_end
+ 1;
3146 ret
= tree
->ops
->fill_delalloc(inode
, page
,
3151 /* File system has been set read-only */
3157 * delalloc_end is already one less than the total
3158 * length, so we don't subtract one from
3161 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3164 delalloc_start
= delalloc_end
+ 1;
3166 if (wbc
->nr_to_write
< delalloc_to_write
) {
3169 if (delalloc_to_write
< thresh
* 2)
3170 thresh
= delalloc_to_write
;
3171 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3175 /* did the fill delalloc function already unlock and start
3181 * we've unlocked the page, so we can't update
3182 * the mapping's writeback index, just update
3185 wbc
->nr_to_write
-= nr_written
;
3189 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3190 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3193 /* Fixup worker will requeue */
3195 wbc
->pages_skipped
++;
3197 redirty_page_for_writepage(wbc
, page
);
3198 update_nr_written(page
, wbc
, nr_written
);
3206 * we don't want to touch the inode after unlocking the page,
3207 * so we update the mapping writeback index now
3209 update_nr_written(page
, wbc
, nr_written
+ 1);
3212 if (last_byte
<= start
) {
3213 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3214 tree
->ops
->writepage_end_io_hook(page
, start
,
3219 blocksize
= inode
->i_sb
->s_blocksize
;
3221 while (cur
<= end
) {
3222 if (cur
>= last_byte
) {
3223 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3224 tree
->ops
->writepage_end_io_hook(page
, cur
,
3228 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
3230 if (IS_ERR_OR_NULL(em
)) {
3235 extent_offset
= cur
- em
->start
;
3236 BUG_ON(extent_map_end(em
) <= cur
);
3238 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
3239 iosize
= ALIGN(iosize
, blocksize
);
3240 sector
= (em
->block_start
+ extent_offset
) >> 9;
3242 block_start
= em
->block_start
;
3243 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3244 free_extent_map(em
);
3248 * compressed and inline extents are written through other
3251 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3252 block_start
== EXTENT_MAP_INLINE
) {
3254 * end_io notification does not happen here for
3255 * compressed extents
3257 if (!compressed
&& tree
->ops
&&
3258 tree
->ops
->writepage_end_io_hook
)
3259 tree
->ops
->writepage_end_io_hook(page
, cur
,
3262 else if (compressed
) {
3263 /* we don't want to end_page_writeback on
3264 * a compressed extent. this happens
3271 pg_offset
+= iosize
;
3274 /* leave this out until we have a page_mkwrite call */
3275 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
3276 EXTENT_DIRTY
, 0, NULL
)) {
3278 pg_offset
+= iosize
;
3282 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
3283 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
3291 unsigned long max_nr
= end_index
+ 1;
3293 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3294 if (!PageWriteback(page
)) {
3295 printk(KERN_ERR
"btrfs warning page %lu not "
3296 "writeback, cur %llu end %llu\n",
3297 page
->index
, cur
, end
);
3300 ret
= submit_extent_page(write_flags
, tree
, page
,
3301 sector
, iosize
, pg_offset
,
3302 bdev
, &epd
->bio
, max_nr
,
3303 end_bio_extent_writepage
,
3309 pg_offset
+= iosize
;
3314 /* make sure the mapping tag for page dirty gets cleared */
3315 set_page_writeback(page
);
3316 end_page_writeback(page
);
3322 /* drop our reference on any cached states */
3323 free_extent_state(cached_state
);
3327 static int eb_wait(void *word
)
3333 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3335 wait_on_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
, eb_wait
,
3336 TASK_UNINTERRUPTIBLE
);
3339 static int lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3340 struct btrfs_fs_info
*fs_info
,
3341 struct extent_page_data
*epd
)
3343 unsigned long i
, num_pages
;
3347 if (!btrfs_try_tree_write_lock(eb
)) {
3349 flush_write_bio(epd
);
3350 btrfs_tree_lock(eb
);
3353 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3354 btrfs_tree_unlock(eb
);
3358 flush_write_bio(epd
);
3362 wait_on_extent_buffer_writeback(eb
);
3363 btrfs_tree_lock(eb
);
3364 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3366 btrfs_tree_unlock(eb
);
3371 * We need to do this to prevent races in people who check if the eb is
3372 * under IO since we can end up having no IO bits set for a short period
3375 spin_lock(&eb
->refs_lock
);
3376 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3377 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3378 spin_unlock(&eb
->refs_lock
);
3379 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3380 __percpu_counter_add(&fs_info
->dirty_metadata_bytes
,
3382 fs_info
->dirty_metadata_batch
);
3385 spin_unlock(&eb
->refs_lock
);
3388 btrfs_tree_unlock(eb
);
3393 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3394 for (i
= 0; i
< num_pages
; i
++) {
3395 struct page
*p
= extent_buffer_page(eb
, i
);
3397 if (!trylock_page(p
)) {
3399 flush_write_bio(epd
);
3409 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3411 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3412 smp_mb__after_clear_bit();
3413 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3416 static void end_bio_extent_buffer_writepage(struct bio
*bio
, int err
)
3418 int uptodate
= err
== 0;
3419 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
3420 struct extent_buffer
*eb
;
3424 struct page
*page
= bvec
->bv_page
;
3427 eb
= (struct extent_buffer
*)page
->private;
3429 done
= atomic_dec_and_test(&eb
->io_pages
);
3431 if (!uptodate
|| test_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
)) {
3432 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3433 ClearPageUptodate(page
);
3437 end_page_writeback(page
);
3442 end_extent_buffer_writeback(eb
);
3443 } while (bvec
>= bio
->bi_io_vec
);
3449 static int write_one_eb(struct extent_buffer
*eb
,
3450 struct btrfs_fs_info
*fs_info
,
3451 struct writeback_control
*wbc
,
3452 struct extent_page_data
*epd
)
3454 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3455 u64 offset
= eb
->start
;
3456 unsigned long i
, num_pages
;
3457 unsigned long bio_flags
= 0;
3458 int rw
= (epd
->sync_io
? WRITE_SYNC
: WRITE
) | REQ_META
;
3461 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3462 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3463 atomic_set(&eb
->io_pages
, num_pages
);
3464 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3465 bio_flags
= EXTENT_BIO_TREE_LOG
;
3467 for (i
= 0; i
< num_pages
; i
++) {
3468 struct page
*p
= extent_buffer_page(eb
, i
);
3470 clear_page_dirty_for_io(p
);
3471 set_page_writeback(p
);
3472 ret
= submit_extent_page(rw
, eb
->tree
, p
, offset
>> 9,
3473 PAGE_CACHE_SIZE
, 0, bdev
, &epd
->bio
,
3474 -1, end_bio_extent_buffer_writepage
,
3475 0, epd
->bio_flags
, bio_flags
);
3476 epd
->bio_flags
= bio_flags
;
3478 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3480 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3481 end_extent_buffer_writeback(eb
);
3485 offset
+= PAGE_CACHE_SIZE
;
3486 update_nr_written(p
, wbc
, 1);
3490 if (unlikely(ret
)) {
3491 for (; i
< num_pages
; i
++) {
3492 struct page
*p
= extent_buffer_page(eb
, i
);
3500 int btree_write_cache_pages(struct address_space
*mapping
,
3501 struct writeback_control
*wbc
)
3503 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3504 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3505 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3506 struct extent_page_data epd
= {
3510 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3515 int nr_to_write_done
= 0;
3516 struct pagevec pvec
;
3519 pgoff_t end
; /* Inclusive */
3523 pagevec_init(&pvec
, 0);
3524 if (wbc
->range_cyclic
) {
3525 index
= mapping
->writeback_index
; /* Start from prev offset */
3528 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3529 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3532 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3533 tag
= PAGECACHE_TAG_TOWRITE
;
3535 tag
= PAGECACHE_TAG_DIRTY
;
3537 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3538 tag_pages_for_writeback(mapping
, index
, end
);
3539 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3540 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3541 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3545 for (i
= 0; i
< nr_pages
; i
++) {
3546 struct page
*page
= pvec
.pages
[i
];
3548 if (!PagePrivate(page
))
3551 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3556 spin_lock(&mapping
->private_lock
);
3557 if (!PagePrivate(page
)) {
3558 spin_unlock(&mapping
->private_lock
);
3562 eb
= (struct extent_buffer
*)page
->private;
3565 * Shouldn't happen and normally this would be a BUG_ON
3566 * but no sense in crashing the users box for something
3567 * we can survive anyway.
3570 spin_unlock(&mapping
->private_lock
);
3574 if (eb
== prev_eb
) {
3575 spin_unlock(&mapping
->private_lock
);
3579 ret
= atomic_inc_not_zero(&eb
->refs
);
3580 spin_unlock(&mapping
->private_lock
);
3585 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3587 free_extent_buffer(eb
);
3591 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3594 free_extent_buffer(eb
);
3597 free_extent_buffer(eb
);
3600 * the filesystem may choose to bump up nr_to_write.
3601 * We have to make sure to honor the new nr_to_write
3604 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3606 pagevec_release(&pvec
);
3609 if (!scanned
&& !done
) {
3611 * We hit the last page and there is more work to be done: wrap
3612 * back to the start of the file
3618 flush_write_bio(&epd
);
3623 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3624 * @mapping: address space structure to write
3625 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3626 * @writepage: function called for each page
3627 * @data: data passed to writepage function
3629 * If a page is already under I/O, write_cache_pages() skips it, even
3630 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3631 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3632 * and msync() need to guarantee that all the data which was dirty at the time
3633 * the call was made get new I/O started against them. If wbc->sync_mode is
3634 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3635 * existing IO to complete.
3637 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
3638 struct address_space
*mapping
,
3639 struct writeback_control
*wbc
,
3640 writepage_t writepage
, void *data
,
3641 void (*flush_fn
)(void *))
3643 struct inode
*inode
= mapping
->host
;
3646 int nr_to_write_done
= 0;
3647 struct pagevec pvec
;
3650 pgoff_t end
; /* Inclusive */
3655 * We have to hold onto the inode so that ordered extents can do their
3656 * work when the IO finishes. The alternative to this is failing to add
3657 * an ordered extent if the igrab() fails there and that is a huge pain
3658 * to deal with, so instead just hold onto the inode throughout the
3659 * writepages operation. If it fails here we are freeing up the inode
3660 * anyway and we'd rather not waste our time writing out stuff that is
3661 * going to be truncated anyway.
3666 pagevec_init(&pvec
, 0);
3667 if (wbc
->range_cyclic
) {
3668 index
= mapping
->writeback_index
; /* Start from prev offset */
3671 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3672 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3675 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3676 tag
= PAGECACHE_TAG_TOWRITE
;
3678 tag
= PAGECACHE_TAG_DIRTY
;
3680 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3681 tag_pages_for_writeback(mapping
, index
, end
);
3682 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3683 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3684 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3688 for (i
= 0; i
< nr_pages
; i
++) {
3689 struct page
*page
= pvec
.pages
[i
];
3692 * At this point we hold neither mapping->tree_lock nor
3693 * lock on the page itself: the page may be truncated or
3694 * invalidated (changing page->mapping to NULL), or even
3695 * swizzled back from swapper_space to tmpfs file
3698 if (!trylock_page(page
)) {
3703 if (unlikely(page
->mapping
!= mapping
)) {
3708 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3714 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
3715 if (PageWriteback(page
))
3717 wait_on_page_writeback(page
);
3720 if (PageWriteback(page
) ||
3721 !clear_page_dirty_for_io(page
)) {
3726 ret
= (*writepage
)(page
, wbc
, data
);
3728 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
3736 * the filesystem may choose to bump up nr_to_write.
3737 * We have to make sure to honor the new nr_to_write
3740 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3742 pagevec_release(&pvec
);
3745 if (!scanned
&& !done
) {
3747 * We hit the last page and there is more work to be done: wrap
3748 * back to the start of the file
3754 btrfs_add_delayed_iput(inode
);
3758 static void flush_epd_write_bio(struct extent_page_data
*epd
)
3767 ret
= submit_one_bio(rw
, epd
->bio
, 0, epd
->bio_flags
);
3768 BUG_ON(ret
< 0); /* -ENOMEM */
3773 static noinline
void flush_write_bio(void *data
)
3775 struct extent_page_data
*epd
= data
;
3776 flush_epd_write_bio(epd
);
3779 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3780 get_extent_t
*get_extent
,
3781 struct writeback_control
*wbc
)
3784 struct extent_page_data epd
= {
3787 .get_extent
= get_extent
,
3789 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3793 ret
= __extent_writepage(page
, wbc
, &epd
);
3795 flush_epd_write_bio(&epd
);
3799 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
3800 u64 start
, u64 end
, get_extent_t
*get_extent
,
3804 struct address_space
*mapping
= inode
->i_mapping
;
3806 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
3809 struct extent_page_data epd
= {
3812 .get_extent
= get_extent
,
3814 .sync_io
= mode
== WB_SYNC_ALL
,
3817 struct writeback_control wbc_writepages
= {
3819 .nr_to_write
= nr_pages
* 2,
3820 .range_start
= start
,
3821 .range_end
= end
+ 1,
3824 while (start
<= end
) {
3825 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
3826 if (clear_page_dirty_for_io(page
))
3827 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
3829 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3830 tree
->ops
->writepage_end_io_hook(page
, start
,
3831 start
+ PAGE_CACHE_SIZE
- 1,
3835 page_cache_release(page
);
3836 start
+= PAGE_CACHE_SIZE
;
3839 flush_epd_write_bio(&epd
);
3843 int extent_writepages(struct extent_io_tree
*tree
,
3844 struct address_space
*mapping
,
3845 get_extent_t
*get_extent
,
3846 struct writeback_control
*wbc
)
3849 struct extent_page_data epd
= {
3852 .get_extent
= get_extent
,
3854 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3858 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
3859 __extent_writepage
, &epd
,
3861 flush_epd_write_bio(&epd
);
3865 int extent_readpages(struct extent_io_tree
*tree
,
3866 struct address_space
*mapping
,
3867 struct list_head
*pages
, unsigned nr_pages
,
3868 get_extent_t get_extent
)
3870 struct bio
*bio
= NULL
;
3872 unsigned long bio_flags
= 0;
3873 struct page
*pagepool
[16];
3875 struct extent_map
*em_cached
= NULL
;
3878 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
3879 page
= list_entry(pages
->prev
, struct page
, lru
);
3881 prefetchw(&page
->flags
);
3882 list_del(&page
->lru
);
3883 if (add_to_page_cache_lru(page
, mapping
,
3884 page
->index
, GFP_NOFS
)) {
3885 page_cache_release(page
);
3889 pagepool
[nr
++] = page
;
3890 if (nr
< ARRAY_SIZE(pagepool
))
3892 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
3893 &bio
, 0, &bio_flags
, READ
);
3897 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
3898 &bio
, 0, &bio_flags
, READ
);
3901 free_extent_map(em_cached
);
3903 BUG_ON(!list_empty(pages
));
3905 return submit_one_bio(READ
, bio
, 0, bio_flags
);
3910 * basic invalidatepage code, this waits on any locked or writeback
3911 * ranges corresponding to the page, and then deletes any extent state
3912 * records from the tree
3914 int extent_invalidatepage(struct extent_io_tree
*tree
,
3915 struct page
*page
, unsigned long offset
)
3917 struct extent_state
*cached_state
= NULL
;
3918 u64 start
= page_offset(page
);
3919 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3920 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
3922 start
+= ALIGN(offset
, blocksize
);
3926 lock_extent_bits(tree
, start
, end
, 0, &cached_state
);
3927 wait_on_page_writeback(page
);
3928 clear_extent_bit(tree
, start
, end
,
3929 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
3930 EXTENT_DO_ACCOUNTING
,
3931 1, 1, &cached_state
, GFP_NOFS
);
3936 * a helper for releasepage, this tests for areas of the page that
3937 * are locked or under IO and drops the related state bits if it is safe
3940 static int try_release_extent_state(struct extent_map_tree
*map
,
3941 struct extent_io_tree
*tree
,
3942 struct page
*page
, gfp_t mask
)
3944 u64 start
= page_offset(page
);
3945 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3948 if (test_range_bit(tree
, start
, end
,
3949 EXTENT_IOBITS
, 0, NULL
))
3952 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
3955 * at this point we can safely clear everything except the
3956 * locked bit and the nodatasum bit
3958 ret
= clear_extent_bit(tree
, start
, end
,
3959 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
3962 /* if clear_extent_bit failed for enomem reasons,
3963 * we can't allow the release to continue.
3974 * a helper for releasepage. As long as there are no locked extents
3975 * in the range corresponding to the page, both state records and extent
3976 * map records are removed
3978 int try_release_extent_mapping(struct extent_map_tree
*map
,
3979 struct extent_io_tree
*tree
, struct page
*page
,
3982 struct extent_map
*em
;
3983 u64 start
= page_offset(page
);
3984 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3986 if ((mask
& __GFP_WAIT
) &&
3987 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
3989 while (start
<= end
) {
3990 len
= end
- start
+ 1;
3991 write_lock(&map
->lock
);
3992 em
= lookup_extent_mapping(map
, start
, len
);
3994 write_unlock(&map
->lock
);
3997 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
3998 em
->start
!= start
) {
3999 write_unlock(&map
->lock
);
4000 free_extent_map(em
);
4003 if (!test_range_bit(tree
, em
->start
,
4004 extent_map_end(em
) - 1,
4005 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
4007 remove_extent_mapping(map
, em
);
4008 /* once for the rb tree */
4009 free_extent_map(em
);
4011 start
= extent_map_end(em
);
4012 write_unlock(&map
->lock
);
4015 free_extent_map(em
);
4018 return try_release_extent_state(map
, tree
, page
, mask
);
4022 * helper function for fiemap, which doesn't want to see any holes.
4023 * This maps until we find something past 'last'
4025 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
4028 get_extent_t
*get_extent
)
4030 u64 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
4031 struct extent_map
*em
;
4038 len
= last
- offset
;
4041 len
= ALIGN(len
, sectorsize
);
4042 em
= get_extent(inode
, NULL
, 0, offset
, len
, 0);
4043 if (IS_ERR_OR_NULL(em
))
4046 /* if this isn't a hole return it */
4047 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
4048 em
->block_start
!= EXTENT_MAP_HOLE
) {
4052 /* this is a hole, advance to the next extent */
4053 offset
= extent_map_end(em
);
4054 free_extent_map(em
);
4061 static noinline
int count_ext_ref(u64 inum
, u64 offset
, u64 root_id
, void *ctx
)
4063 unsigned long cnt
= *((unsigned long *)ctx
);
4066 *((unsigned long *)ctx
) = cnt
;
4068 /* Now we're sure that the extent is shared. */
4074 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4075 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
4079 u64 max
= start
+ len
;
4083 u64 last_for_get_extent
= 0;
4085 u64 isize
= i_size_read(inode
);
4086 struct btrfs_key found_key
;
4087 struct extent_map
*em
= NULL
;
4088 struct extent_state
*cached_state
= NULL
;
4089 struct btrfs_path
*path
;
4090 struct btrfs_file_extent_item
*item
;
4095 unsigned long emflags
;
4100 path
= btrfs_alloc_path();
4103 path
->leave_spinning
= 1;
4105 start
= ALIGN(start
, BTRFS_I(inode
)->root
->sectorsize
);
4106 len
= ALIGN(len
, BTRFS_I(inode
)->root
->sectorsize
);
4109 * lookup the last file extent. We're not using i_size here
4110 * because there might be preallocation past i_size
4112 ret
= btrfs_lookup_file_extent(NULL
, BTRFS_I(inode
)->root
,
4113 path
, btrfs_ino(inode
), -1, 0);
4115 btrfs_free_path(path
);
4120 item
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
4121 struct btrfs_file_extent_item
);
4122 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
4123 found_type
= btrfs_key_type(&found_key
);
4125 /* No extents, but there might be delalloc bits */
4126 if (found_key
.objectid
!= btrfs_ino(inode
) ||
4127 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
4128 /* have to trust i_size as the end */
4130 last_for_get_extent
= isize
;
4133 * remember the start of the last extent. There are a
4134 * bunch of different factors that go into the length of the
4135 * extent, so its much less complex to remember where it started
4137 last
= found_key
.offset
;
4138 last_for_get_extent
= last
+ 1;
4140 btrfs_release_path(path
);
4143 * we might have some extents allocated but more delalloc past those
4144 * extents. so, we trust isize unless the start of the last extent is
4149 last_for_get_extent
= isize
;
4152 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1, 0,
4155 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4165 u64 offset_in_extent
= 0;
4167 /* break if the extent we found is outside the range */
4168 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4172 * get_extent may return an extent that starts before our
4173 * requested range. We have to make sure the ranges
4174 * we return to fiemap always move forward and don't
4175 * overlap, so adjust the offsets here
4177 em_start
= max(em
->start
, off
);
4180 * record the offset from the start of the extent
4181 * for adjusting the disk offset below. Only do this if the
4182 * extent isn't compressed since our in ram offset may be past
4183 * what we have actually allocated on disk.
4185 if (!test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4186 offset_in_extent
= em_start
- em
->start
;
4187 em_end
= extent_map_end(em
);
4188 em_len
= em_end
- em_start
;
4189 emflags
= em
->flags
;
4194 * bump off for our next call to get_extent
4196 off
= extent_map_end(em
);
4200 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4202 flags
|= FIEMAP_EXTENT_LAST
;
4203 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4204 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4205 FIEMAP_EXTENT_NOT_ALIGNED
);
4206 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4207 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4208 FIEMAP_EXTENT_UNKNOWN
);
4210 unsigned long ref_cnt
= 0;
4212 disko
= em
->block_start
+ offset_in_extent
;
4215 * As btrfs supports shared space, this information
4216 * can be exported to userspace tools via
4217 * flag FIEMAP_EXTENT_SHARED.
4219 ret
= iterate_inodes_from_logical(
4221 BTRFS_I(inode
)->root
->fs_info
,
4222 path
, count_ext_ref
, &ref_cnt
);
4223 if (ret
< 0 && ret
!= -ENOENT
)
4227 flags
|= FIEMAP_EXTENT_SHARED
;
4229 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4230 flags
|= FIEMAP_EXTENT_ENCODED
;
4232 free_extent_map(em
);
4234 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4235 (last
== (u64
)-1 && isize
<= em_end
)) {
4236 flags
|= FIEMAP_EXTENT_LAST
;
4240 /* now scan forward to see if this is really the last extent. */
4241 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4248 flags
|= FIEMAP_EXTENT_LAST
;
4251 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
4257 free_extent_map(em
);
4259 btrfs_free_path(path
);
4260 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4261 &cached_state
, GFP_NOFS
);
4265 static void __free_extent_buffer(struct extent_buffer
*eb
)
4267 btrfs_leak_debug_del(&eb
->leak_list
);
4268 kmem_cache_free(extent_buffer_cache
, eb
);
4271 static int extent_buffer_under_io(struct extent_buffer
*eb
)
4273 return (atomic_read(&eb
->io_pages
) ||
4274 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4275 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4279 * Helper for releasing extent buffer page.
4281 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
,
4282 unsigned long start_idx
)
4284 unsigned long index
;
4285 unsigned long num_pages
;
4287 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4289 BUG_ON(extent_buffer_under_io(eb
));
4291 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4292 index
= start_idx
+ num_pages
;
4293 if (start_idx
>= index
)
4298 page
= extent_buffer_page(eb
, index
);
4299 if (page
&& mapped
) {
4300 spin_lock(&page
->mapping
->private_lock
);
4302 * We do this since we'll remove the pages after we've
4303 * removed the eb from the radix tree, so we could race
4304 * and have this page now attached to the new eb. So
4305 * only clear page_private if it's still connected to
4308 if (PagePrivate(page
) &&
4309 page
->private == (unsigned long)eb
) {
4310 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4311 BUG_ON(PageDirty(page
));
4312 BUG_ON(PageWriteback(page
));
4314 * We need to make sure we haven't be attached
4317 ClearPagePrivate(page
);
4318 set_page_private(page
, 0);
4319 /* One for the page private */
4320 page_cache_release(page
);
4322 spin_unlock(&page
->mapping
->private_lock
);
4326 /* One for when we alloced the page */
4327 page_cache_release(page
);
4329 } while (index
!= start_idx
);
4333 * Helper for releasing the extent buffer.
4335 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4337 btrfs_release_extent_buffer_page(eb
, 0);
4338 __free_extent_buffer(eb
);
4341 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
4346 struct extent_buffer
*eb
= NULL
;
4348 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
4355 rwlock_init(&eb
->lock
);
4356 atomic_set(&eb
->write_locks
, 0);
4357 atomic_set(&eb
->read_locks
, 0);
4358 atomic_set(&eb
->blocking_readers
, 0);
4359 atomic_set(&eb
->blocking_writers
, 0);
4360 atomic_set(&eb
->spinning_readers
, 0);
4361 atomic_set(&eb
->spinning_writers
, 0);
4362 eb
->lock_nested
= 0;
4363 init_waitqueue_head(&eb
->write_lock_wq
);
4364 init_waitqueue_head(&eb
->read_lock_wq
);
4366 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4368 spin_lock_init(&eb
->refs_lock
);
4369 atomic_set(&eb
->refs
, 1);
4370 atomic_set(&eb
->io_pages
, 0);
4373 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4375 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4376 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4377 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4382 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4386 struct extent_buffer
*new;
4387 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4389 new = __alloc_extent_buffer(NULL
, src
->start
, src
->len
, GFP_NOFS
);
4393 for (i
= 0; i
< num_pages
; i
++) {
4394 p
= alloc_page(GFP_NOFS
);
4396 btrfs_release_extent_buffer(new);
4399 attach_extent_buffer_page(new, p
);
4400 WARN_ON(PageDirty(p
));
4405 copy_extent_buffer(new, src
, 0, 0, src
->len
);
4406 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4407 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4412 struct extent_buffer
*alloc_dummy_extent_buffer(u64 start
, unsigned long len
)
4414 struct extent_buffer
*eb
;
4415 unsigned long num_pages
= num_extent_pages(0, len
);
4418 eb
= __alloc_extent_buffer(NULL
, start
, len
, GFP_NOFS
);
4422 for (i
= 0; i
< num_pages
; i
++) {
4423 eb
->pages
[i
] = alloc_page(GFP_NOFS
);
4427 set_extent_buffer_uptodate(eb
);
4428 btrfs_set_header_nritems(eb
, 0);
4429 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4434 __free_page(eb
->pages
[i
- 1]);
4435 __free_extent_buffer(eb
);
4439 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4442 /* the ref bit is tricky. We have to make sure it is set
4443 * if we have the buffer dirty. Otherwise the
4444 * code to free a buffer can end up dropping a dirty
4447 * Once the ref bit is set, it won't go away while the
4448 * buffer is dirty or in writeback, and it also won't
4449 * go away while we have the reference count on the
4452 * We can't just set the ref bit without bumping the
4453 * ref on the eb because free_extent_buffer might
4454 * see the ref bit and try to clear it. If this happens
4455 * free_extent_buffer might end up dropping our original
4456 * ref by mistake and freeing the page before we are able
4457 * to add one more ref.
4459 * So bump the ref count first, then set the bit. If someone
4460 * beat us to it, drop the ref we added.
4462 refs
= atomic_read(&eb
->refs
);
4463 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4466 spin_lock(&eb
->refs_lock
);
4467 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4468 atomic_inc(&eb
->refs
);
4469 spin_unlock(&eb
->refs_lock
);
4472 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
)
4474 unsigned long num_pages
, i
;
4476 check_buffer_tree_ref(eb
);
4478 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4479 for (i
= 0; i
< num_pages
; i
++) {
4480 struct page
*p
= extent_buffer_page(eb
, i
);
4481 mark_page_accessed(p
);
4485 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
4488 struct extent_buffer
*eb
;
4491 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4492 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4494 mark_extent_buffer_accessed(eb
);
4502 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
4503 u64 start
, unsigned long len
)
4505 unsigned long num_pages
= num_extent_pages(start
, len
);
4507 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
4508 struct extent_buffer
*eb
;
4509 struct extent_buffer
*exists
= NULL
;
4511 struct address_space
*mapping
= tree
->mapping
;
4516 eb
= find_extent_buffer(tree
, start
);
4520 eb
= __alloc_extent_buffer(tree
, start
, len
, GFP_NOFS
);
4524 for (i
= 0; i
< num_pages
; i
++, index
++) {
4525 p
= find_or_create_page(mapping
, index
, GFP_NOFS
);
4529 spin_lock(&mapping
->private_lock
);
4530 if (PagePrivate(p
)) {
4532 * We could have already allocated an eb for this page
4533 * and attached one so lets see if we can get a ref on
4534 * the existing eb, and if we can we know it's good and
4535 * we can just return that one, else we know we can just
4536 * overwrite page->private.
4538 exists
= (struct extent_buffer
*)p
->private;
4539 if (atomic_inc_not_zero(&exists
->refs
)) {
4540 spin_unlock(&mapping
->private_lock
);
4542 page_cache_release(p
);
4543 mark_extent_buffer_accessed(exists
);
4548 * Do this so attach doesn't complain and we need to
4549 * drop the ref the old guy had.
4551 ClearPagePrivate(p
);
4552 WARN_ON(PageDirty(p
));
4553 page_cache_release(p
);
4555 attach_extent_buffer_page(eb
, p
);
4556 spin_unlock(&mapping
->private_lock
);
4557 WARN_ON(PageDirty(p
));
4558 mark_page_accessed(p
);
4560 if (!PageUptodate(p
))
4564 * see below about how we avoid a nasty race with release page
4565 * and why we unlock later
4569 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4571 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
4575 spin_lock(&tree
->buffer_lock
);
4576 ret
= radix_tree_insert(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
, eb
);
4577 spin_unlock(&tree
->buffer_lock
);
4578 radix_tree_preload_end();
4579 if (ret
== -EEXIST
) {
4580 exists
= find_extent_buffer(tree
, start
);
4586 /* add one reference for the tree */
4587 check_buffer_tree_ref(eb
);
4590 * there is a race where release page may have
4591 * tried to find this extent buffer in the radix
4592 * but failed. It will tell the VM it is safe to
4593 * reclaim the, and it will clear the page private bit.
4594 * We must make sure to set the page private bit properly
4595 * after the extent buffer is in the radix tree so
4596 * it doesn't get lost
4598 SetPageChecked(eb
->pages
[0]);
4599 for (i
= 1; i
< num_pages
; i
++) {
4600 p
= extent_buffer_page(eb
, i
);
4601 ClearPageChecked(p
);
4604 unlock_page(eb
->pages
[0]);
4608 for (i
= 0; i
< num_pages
; i
++) {
4610 unlock_page(eb
->pages
[i
]);
4613 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
4614 btrfs_release_extent_buffer(eb
);
4618 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
4620 struct extent_buffer
*eb
=
4621 container_of(head
, struct extent_buffer
, rcu_head
);
4623 __free_extent_buffer(eb
);
4626 /* Expects to have eb->eb_lock already held */
4627 static int release_extent_buffer(struct extent_buffer
*eb
)
4629 WARN_ON(atomic_read(&eb
->refs
) == 0);
4630 if (atomic_dec_and_test(&eb
->refs
)) {
4631 if (test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
)) {
4632 spin_unlock(&eb
->refs_lock
);
4634 struct extent_io_tree
*tree
= eb
->tree
;
4636 spin_unlock(&eb
->refs_lock
);
4638 spin_lock(&tree
->buffer_lock
);
4639 radix_tree_delete(&tree
->buffer
,
4640 eb
->start
>> PAGE_CACHE_SHIFT
);
4641 spin_unlock(&tree
->buffer_lock
);
4644 /* Should be safe to release our pages at this point */
4645 btrfs_release_extent_buffer_page(eb
, 0);
4646 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
4649 spin_unlock(&eb
->refs_lock
);
4654 void free_extent_buffer(struct extent_buffer
*eb
)
4662 refs
= atomic_read(&eb
->refs
);
4665 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
4670 spin_lock(&eb
->refs_lock
);
4671 if (atomic_read(&eb
->refs
) == 2 &&
4672 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
4673 atomic_dec(&eb
->refs
);
4675 if (atomic_read(&eb
->refs
) == 2 &&
4676 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
4677 !extent_buffer_under_io(eb
) &&
4678 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4679 atomic_dec(&eb
->refs
);
4682 * I know this is terrible, but it's temporary until we stop tracking
4683 * the uptodate bits and such for the extent buffers.
4685 release_extent_buffer(eb
);
4688 void free_extent_buffer_stale(struct extent_buffer
*eb
)
4693 spin_lock(&eb
->refs_lock
);
4694 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
4696 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
4697 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4698 atomic_dec(&eb
->refs
);
4699 release_extent_buffer(eb
);
4702 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
4705 unsigned long num_pages
;
4708 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4710 for (i
= 0; i
< num_pages
; i
++) {
4711 page
= extent_buffer_page(eb
, i
);
4712 if (!PageDirty(page
))
4716 WARN_ON(!PagePrivate(page
));
4718 clear_page_dirty_for_io(page
);
4719 spin_lock_irq(&page
->mapping
->tree_lock
);
4720 if (!PageDirty(page
)) {
4721 radix_tree_tag_clear(&page
->mapping
->page_tree
,
4723 PAGECACHE_TAG_DIRTY
);
4725 spin_unlock_irq(&page
->mapping
->tree_lock
);
4726 ClearPageError(page
);
4729 WARN_ON(atomic_read(&eb
->refs
) == 0);
4732 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
4735 unsigned long num_pages
;
4738 check_buffer_tree_ref(eb
);
4740 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
4742 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4743 WARN_ON(atomic_read(&eb
->refs
) == 0);
4744 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
4746 for (i
= 0; i
< num_pages
; i
++)
4747 set_page_dirty(extent_buffer_page(eb
, i
));
4751 int clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
4755 unsigned long num_pages
;
4757 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4758 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4759 for (i
= 0; i
< num_pages
; i
++) {
4760 page
= extent_buffer_page(eb
, i
);
4762 ClearPageUptodate(page
);
4767 int set_extent_buffer_uptodate(struct extent_buffer
*eb
)
4771 unsigned long num_pages
;
4773 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4774 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4775 for (i
= 0; i
< num_pages
; i
++) {
4776 page
= extent_buffer_page(eb
, i
);
4777 SetPageUptodate(page
);
4782 int extent_buffer_uptodate(struct extent_buffer
*eb
)
4784 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4787 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
4788 struct extent_buffer
*eb
, u64 start
, int wait
,
4789 get_extent_t
*get_extent
, int mirror_num
)
4792 unsigned long start_i
;
4796 int locked_pages
= 0;
4797 int all_uptodate
= 1;
4798 unsigned long num_pages
;
4799 unsigned long num_reads
= 0;
4800 struct bio
*bio
= NULL
;
4801 unsigned long bio_flags
= 0;
4803 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
4807 WARN_ON(start
< eb
->start
);
4808 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
4809 (eb
->start
>> PAGE_CACHE_SHIFT
);
4814 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4815 for (i
= start_i
; i
< num_pages
; i
++) {
4816 page
= extent_buffer_page(eb
, i
);
4817 if (wait
== WAIT_NONE
) {
4818 if (!trylock_page(page
))
4824 if (!PageUptodate(page
)) {
4831 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4835 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
4836 eb
->read_mirror
= 0;
4837 atomic_set(&eb
->io_pages
, num_reads
);
4838 for (i
= start_i
; i
< num_pages
; i
++) {
4839 page
= extent_buffer_page(eb
, i
);
4840 if (!PageUptodate(page
)) {
4841 ClearPageError(page
);
4842 err
= __extent_read_full_page(tree
, page
,
4844 mirror_num
, &bio_flags
,
4854 err
= submit_one_bio(READ
| REQ_META
, bio
, mirror_num
,
4860 if (ret
|| wait
!= WAIT_COMPLETE
)
4863 for (i
= start_i
; i
< num_pages
; i
++) {
4864 page
= extent_buffer_page(eb
, i
);
4865 wait_on_page_locked(page
);
4866 if (!PageUptodate(page
))
4874 while (locked_pages
> 0) {
4875 page
= extent_buffer_page(eb
, i
);
4883 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
4884 unsigned long start
,
4891 char *dst
= (char *)dstv
;
4892 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4893 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4895 WARN_ON(start
> eb
->len
);
4896 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4898 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4901 page
= extent_buffer_page(eb
, i
);
4903 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4904 kaddr
= page_address(page
);
4905 memcpy(dst
, kaddr
+ offset
, cur
);
4914 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
4915 unsigned long min_len
, char **map
,
4916 unsigned long *map_start
,
4917 unsigned long *map_len
)
4919 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
4922 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4923 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4924 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
4931 offset
= start_offset
;
4935 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
4938 if (start
+ min_len
> eb
->len
) {
4939 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
4941 eb
->start
, eb
->len
, start
, min_len
);
4945 p
= extent_buffer_page(eb
, i
);
4946 kaddr
= page_address(p
);
4947 *map
= kaddr
+ offset
;
4948 *map_len
= PAGE_CACHE_SIZE
- offset
;
4952 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
4953 unsigned long start
,
4960 char *ptr
= (char *)ptrv
;
4961 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4962 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4965 WARN_ON(start
> eb
->len
);
4966 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4968 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4971 page
= extent_buffer_page(eb
, i
);
4973 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4975 kaddr
= page_address(page
);
4976 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
4988 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
4989 unsigned long start
, unsigned long len
)
4995 char *src
= (char *)srcv
;
4996 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4997 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4999 WARN_ON(start
> eb
->len
);
5000 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5002 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5005 page
= extent_buffer_page(eb
, i
);
5006 WARN_ON(!PageUptodate(page
));
5008 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
5009 kaddr
= page_address(page
);
5010 memcpy(kaddr
+ offset
, src
, cur
);
5019 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
5020 unsigned long start
, unsigned long len
)
5026 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5027 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5029 WARN_ON(start
> eb
->len
);
5030 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5032 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5035 page
= extent_buffer_page(eb
, i
);
5036 WARN_ON(!PageUptodate(page
));
5038 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
5039 kaddr
= page_address(page
);
5040 memset(kaddr
+ offset
, c
, cur
);
5048 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
5049 unsigned long dst_offset
, unsigned long src_offset
,
5052 u64 dst_len
= dst
->len
;
5057 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5058 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5060 WARN_ON(src
->len
!= dst_len
);
5062 offset
= (start_offset
+ dst_offset
) &
5063 (PAGE_CACHE_SIZE
- 1);
5066 page
= extent_buffer_page(dst
, i
);
5067 WARN_ON(!PageUptodate(page
));
5069 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
5071 kaddr
= page_address(page
);
5072 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
5081 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
5083 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
5084 return distance
< len
;
5087 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
5088 unsigned long dst_off
, unsigned long src_off
,
5091 char *dst_kaddr
= page_address(dst_page
);
5093 int must_memmove
= 0;
5095 if (dst_page
!= src_page
) {
5096 src_kaddr
= page_address(src_page
);
5098 src_kaddr
= dst_kaddr
;
5099 if (areas_overlap(src_off
, dst_off
, len
))
5104 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5106 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5109 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5110 unsigned long src_offset
, unsigned long len
)
5113 size_t dst_off_in_page
;
5114 size_t src_off_in_page
;
5115 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5116 unsigned long dst_i
;
5117 unsigned long src_i
;
5119 if (src_offset
+ len
> dst
->len
) {
5120 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5121 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
5124 if (dst_offset
+ len
> dst
->len
) {
5125 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5126 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
5131 dst_off_in_page
= (start_offset
+ dst_offset
) &
5132 (PAGE_CACHE_SIZE
- 1);
5133 src_off_in_page
= (start_offset
+ src_offset
) &
5134 (PAGE_CACHE_SIZE
- 1);
5136 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5137 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
5139 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
5141 cur
= min_t(unsigned long, cur
,
5142 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
5144 copy_pages(extent_buffer_page(dst
, dst_i
),
5145 extent_buffer_page(dst
, src_i
),
5146 dst_off_in_page
, src_off_in_page
, cur
);
5154 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5155 unsigned long src_offset
, unsigned long len
)
5158 size_t dst_off_in_page
;
5159 size_t src_off_in_page
;
5160 unsigned long dst_end
= dst_offset
+ len
- 1;
5161 unsigned long src_end
= src_offset
+ len
- 1;
5162 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5163 unsigned long dst_i
;
5164 unsigned long src_i
;
5166 if (src_offset
+ len
> dst
->len
) {
5167 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5168 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
5171 if (dst_offset
+ len
> dst
->len
) {
5172 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5173 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
5176 if (dst_offset
< src_offset
) {
5177 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5181 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
5182 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
5184 dst_off_in_page
= (start_offset
+ dst_end
) &
5185 (PAGE_CACHE_SIZE
- 1);
5186 src_off_in_page
= (start_offset
+ src_end
) &
5187 (PAGE_CACHE_SIZE
- 1);
5189 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5190 cur
= min(cur
, dst_off_in_page
+ 1);
5191 copy_pages(extent_buffer_page(dst
, dst_i
),
5192 extent_buffer_page(dst
, src_i
),
5193 dst_off_in_page
- cur
+ 1,
5194 src_off_in_page
- cur
+ 1, cur
);
5202 int try_release_extent_buffer(struct page
*page
)
5204 struct extent_buffer
*eb
;
5207 * We need to make sure noboody is attaching this page to an eb right
5210 spin_lock(&page
->mapping
->private_lock
);
5211 if (!PagePrivate(page
)) {
5212 spin_unlock(&page
->mapping
->private_lock
);
5216 eb
= (struct extent_buffer
*)page
->private;
5220 * This is a little awful but should be ok, we need to make sure that
5221 * the eb doesn't disappear out from under us while we're looking at
5224 spin_lock(&eb
->refs_lock
);
5225 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
5226 spin_unlock(&eb
->refs_lock
);
5227 spin_unlock(&page
->mapping
->private_lock
);
5230 spin_unlock(&page
->mapping
->private_lock
);
5233 * If tree ref isn't set then we know the ref on this eb is a real ref,
5234 * so just return, this page will likely be freed soon anyway.
5236 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
5237 spin_unlock(&eb
->refs_lock
);
5241 return release_extent_buffer(eb
);