1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/spinlock.h>
8 #include <linux/blkdev.h>
9 #include <linux/swap.h>
10 #include <linux/writeback.h>
11 #include <linux/pagevec.h>
12 #include <linux/prefetch.h>
13 #include <linux/cleancache.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
17 #include "btrfs_inode.h"
19 #include "check-integrity.h"
21 #include "rcu-string.h"
24 static struct kmem_cache
*extent_state_cache
;
25 static struct kmem_cache
*extent_buffer_cache
;
26 static struct bio_set
*btrfs_bioset
;
28 #ifdef CONFIG_BTRFS_DEBUG
29 static LIST_HEAD(buffers
);
30 static LIST_HEAD(states
);
32 static DEFINE_SPINLOCK(leak_lock
);
35 void btrfs_leak_debug_add(struct list_head
*new, struct list_head
*head
)
39 spin_lock_irqsave(&leak_lock
, flags
);
41 spin_unlock_irqrestore(&leak_lock
, flags
);
45 void btrfs_leak_debug_del(struct list_head
*entry
)
49 spin_lock_irqsave(&leak_lock
, flags
);
51 spin_unlock_irqrestore(&leak_lock
, flags
);
55 void btrfs_leak_debug_check(void)
57 struct extent_state
*state
;
58 struct extent_buffer
*eb
;
60 while (!list_empty(&states
)) {
61 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
62 printk(KERN_ERR
"btrfs state leak: start %llu end %llu "
63 "state %lu in tree %p refs %d\n",
64 state
->start
, state
->end
, state
->state
, state
->tree
,
65 atomic_read(&state
->refs
));
66 list_del(&state
->leak_list
);
67 kmem_cache_free(extent_state_cache
, state
);
70 while (!list_empty(&buffers
)) {
71 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
72 printk(KERN_ERR
"btrfs buffer leak start %llu len %lu "
74 eb
->start
, eb
->len
, atomic_read(&eb
->refs
));
75 list_del(&eb
->leak_list
);
76 kmem_cache_free(extent_buffer_cache
, eb
);
80 #define btrfs_debug_check_extent_io_range(inode, start, end) \
81 __btrfs_debug_check_extent_io_range(__func__, (inode), (start), (end))
82 static inline void __btrfs_debug_check_extent_io_range(const char *caller
,
83 struct inode
*inode
, u64 start
, u64 end
)
85 u64 isize
= i_size_read(inode
);
87 if (end
>= PAGE_SIZE
&& (end
% 2) == 0 && end
!= isize
- 1) {
88 printk_ratelimited(KERN_DEBUG
89 "btrfs: %s: ino %llu isize %llu odd range [%llu,%llu]\n",
90 caller
, btrfs_ino(inode
), isize
, start
, end
);
94 #define btrfs_leak_debug_add(new, head) do {} while (0)
95 #define btrfs_leak_debug_del(entry) do {} while (0)
96 #define btrfs_leak_debug_check() do {} while (0)
97 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
100 #define BUFFER_LRU_MAX 64
105 struct rb_node rb_node
;
108 struct extent_page_data
{
110 struct extent_io_tree
*tree
;
111 get_extent_t
*get_extent
;
112 unsigned long bio_flags
;
114 /* tells writepage not to lock the state bits for this range
115 * it still does the unlocking
117 unsigned int extent_locked
:1;
119 /* tells the submit_bio code to use a WRITE_SYNC */
120 unsigned int sync_io
:1;
123 static noinline
void flush_write_bio(void *data
);
124 static inline struct btrfs_fs_info
*
125 tree_fs_info(struct extent_io_tree
*tree
)
127 return btrfs_sb(tree
->mapping
->host
->i_sb
);
130 int __init
extent_io_init(void)
132 extent_state_cache
= kmem_cache_create("btrfs_extent_state",
133 sizeof(struct extent_state
), 0,
134 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
135 if (!extent_state_cache
)
138 extent_buffer_cache
= kmem_cache_create("btrfs_extent_buffer",
139 sizeof(struct extent_buffer
), 0,
140 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
141 if (!extent_buffer_cache
)
142 goto free_state_cache
;
144 btrfs_bioset
= bioset_create(BIO_POOL_SIZE
,
145 offsetof(struct btrfs_io_bio
, bio
));
147 goto free_buffer_cache
;
149 if (bioset_integrity_create(btrfs_bioset
, BIO_POOL_SIZE
))
155 bioset_free(btrfs_bioset
);
159 kmem_cache_destroy(extent_buffer_cache
);
160 extent_buffer_cache
= NULL
;
163 kmem_cache_destroy(extent_state_cache
);
164 extent_state_cache
= NULL
;
168 void extent_io_exit(void)
170 btrfs_leak_debug_check();
173 * Make sure all delayed rcu free are flushed before we
177 if (extent_state_cache
)
178 kmem_cache_destroy(extent_state_cache
);
179 if (extent_buffer_cache
)
180 kmem_cache_destroy(extent_buffer_cache
);
182 bioset_free(btrfs_bioset
);
185 void extent_io_tree_init(struct extent_io_tree
*tree
,
186 struct address_space
*mapping
)
188 tree
->state
= RB_ROOT
;
189 INIT_RADIX_TREE(&tree
->buffer
, GFP_ATOMIC
);
191 tree
->dirty_bytes
= 0;
192 spin_lock_init(&tree
->lock
);
193 spin_lock_init(&tree
->buffer_lock
);
194 tree
->mapping
= mapping
;
197 static struct extent_state
*alloc_extent_state(gfp_t mask
)
199 struct extent_state
*state
;
201 state
= kmem_cache_alloc(extent_state_cache
, mask
);
207 btrfs_leak_debug_add(&state
->leak_list
, &states
);
208 atomic_set(&state
->refs
, 1);
209 init_waitqueue_head(&state
->wq
);
210 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
214 void free_extent_state(struct extent_state
*state
)
218 if (atomic_dec_and_test(&state
->refs
)) {
219 WARN_ON(state
->tree
);
220 btrfs_leak_debug_del(&state
->leak_list
);
221 trace_free_extent_state(state
, _RET_IP_
);
222 kmem_cache_free(extent_state_cache
, state
);
226 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
227 struct rb_node
*node
)
229 struct rb_node
**p
= &root
->rb_node
;
230 struct rb_node
*parent
= NULL
;
231 struct tree_entry
*entry
;
235 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
237 if (offset
< entry
->start
)
239 else if (offset
> entry
->end
)
245 rb_link_node(node
, parent
, p
);
246 rb_insert_color(node
, root
);
250 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
251 struct rb_node
**prev_ret
,
252 struct rb_node
**next_ret
)
254 struct rb_root
*root
= &tree
->state
;
255 struct rb_node
*n
= root
->rb_node
;
256 struct rb_node
*prev
= NULL
;
257 struct rb_node
*orig_prev
= NULL
;
258 struct tree_entry
*entry
;
259 struct tree_entry
*prev_entry
= NULL
;
262 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
266 if (offset
< entry
->start
)
268 else if (offset
> entry
->end
)
276 while (prev
&& offset
> prev_entry
->end
) {
277 prev
= rb_next(prev
);
278 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
285 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
286 while (prev
&& offset
< prev_entry
->start
) {
287 prev
= rb_prev(prev
);
288 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
295 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
298 struct rb_node
*prev
= NULL
;
301 ret
= __etree_search(tree
, offset
, &prev
, NULL
);
307 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
308 struct extent_state
*other
)
310 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
311 tree
->ops
->merge_extent_hook(tree
->mapping
->host
, new,
316 * utility function to look for merge candidates inside a given range.
317 * Any extents with matching state are merged together into a single
318 * extent in the tree. Extents with EXTENT_IO in their state field
319 * are not merged because the end_io handlers need to be able to do
320 * operations on them without sleeping (or doing allocations/splits).
322 * This should be called with the tree lock held.
324 static void merge_state(struct extent_io_tree
*tree
,
325 struct extent_state
*state
)
327 struct extent_state
*other
;
328 struct rb_node
*other_node
;
330 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
333 other_node
= rb_prev(&state
->rb_node
);
335 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
336 if (other
->end
== state
->start
- 1 &&
337 other
->state
== state
->state
) {
338 merge_cb(tree
, state
, other
);
339 state
->start
= other
->start
;
341 rb_erase(&other
->rb_node
, &tree
->state
);
342 free_extent_state(other
);
345 other_node
= rb_next(&state
->rb_node
);
347 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
348 if (other
->start
== state
->end
+ 1 &&
349 other
->state
== state
->state
) {
350 merge_cb(tree
, state
, other
);
351 state
->end
= other
->end
;
353 rb_erase(&other
->rb_node
, &tree
->state
);
354 free_extent_state(other
);
359 static void set_state_cb(struct extent_io_tree
*tree
,
360 struct extent_state
*state
, unsigned long *bits
)
362 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
363 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
, bits
);
366 static void clear_state_cb(struct extent_io_tree
*tree
,
367 struct extent_state
*state
, unsigned long *bits
)
369 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
370 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
, bits
);
373 static void set_state_bits(struct extent_io_tree
*tree
,
374 struct extent_state
*state
, unsigned long *bits
);
377 * insert an extent_state struct into the tree. 'bits' are set on the
378 * struct before it is inserted.
380 * This may return -EEXIST if the extent is already there, in which case the
381 * state struct is freed.
383 * The tree lock is not taken internally. This is a utility function and
384 * probably isn't what you want to call (see set/clear_extent_bit).
386 static int insert_state(struct extent_io_tree
*tree
,
387 struct extent_state
*state
, u64 start
, u64 end
,
390 struct rb_node
*node
;
393 WARN(1, KERN_ERR
"btrfs end < start %llu %llu\n",
395 state
->start
= start
;
398 set_state_bits(tree
, state
, bits
);
400 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
402 struct extent_state
*found
;
403 found
= rb_entry(node
, struct extent_state
, rb_node
);
404 printk(KERN_ERR
"btrfs found node %llu %llu on insert of "
406 found
->start
, found
->end
, start
, end
);
410 merge_state(tree
, state
);
414 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
417 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
418 tree
->ops
->split_extent_hook(tree
->mapping
->host
, orig
, split
);
422 * split a given extent state struct in two, inserting the preallocated
423 * struct 'prealloc' as the newly created second half. 'split' indicates an
424 * offset inside 'orig' where it should be split.
427 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
428 * are two extent state structs in the tree:
429 * prealloc: [orig->start, split - 1]
430 * orig: [ split, orig->end ]
432 * The tree locks are not taken by this function. They need to be held
435 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
436 struct extent_state
*prealloc
, u64 split
)
438 struct rb_node
*node
;
440 split_cb(tree
, orig
, split
);
442 prealloc
->start
= orig
->start
;
443 prealloc
->end
= split
- 1;
444 prealloc
->state
= orig
->state
;
447 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
449 free_extent_state(prealloc
);
452 prealloc
->tree
= tree
;
456 static struct extent_state
*next_state(struct extent_state
*state
)
458 struct rb_node
*next
= rb_next(&state
->rb_node
);
460 return rb_entry(next
, struct extent_state
, rb_node
);
466 * utility function to clear some bits in an extent state struct.
467 * it will optionally wake up any one waiting on this state (wake == 1).
469 * If no bits are set on the state struct after clearing things, the
470 * struct is freed and removed from the tree
472 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
473 struct extent_state
*state
,
474 unsigned long *bits
, int wake
)
476 struct extent_state
*next
;
477 unsigned long bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
479 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
480 u64 range
= state
->end
- state
->start
+ 1;
481 WARN_ON(range
> tree
->dirty_bytes
);
482 tree
->dirty_bytes
-= range
;
484 clear_state_cb(tree
, state
, bits
);
485 state
->state
&= ~bits_to_clear
;
488 if (state
->state
== 0) {
489 next
= next_state(state
);
491 rb_erase(&state
->rb_node
, &tree
->state
);
493 free_extent_state(state
);
498 merge_state(tree
, state
);
499 next
= next_state(state
);
504 static struct extent_state
*
505 alloc_extent_state_atomic(struct extent_state
*prealloc
)
508 prealloc
= alloc_extent_state(GFP_ATOMIC
);
513 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
515 btrfs_panic(tree_fs_info(tree
), err
, "Locking error: "
516 "Extent tree was modified by another "
517 "thread while locked.");
521 * clear some bits on a range in the tree. This may require splitting
522 * or inserting elements in the tree, so the gfp mask is used to
523 * indicate which allocations or sleeping are allowed.
525 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
526 * the given range from the tree regardless of state (ie for truncate).
528 * the range [start, end] is inclusive.
530 * This takes the tree lock, and returns 0 on success and < 0 on error.
532 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
533 unsigned long bits
, int wake
, int delete,
534 struct extent_state
**cached_state
,
537 struct extent_state
*state
;
538 struct extent_state
*cached
;
539 struct extent_state
*prealloc
= NULL
;
540 struct rb_node
*node
;
545 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
547 if (bits
& EXTENT_DELALLOC
)
548 bits
|= EXTENT_NORESERVE
;
551 bits
|= ~EXTENT_CTLBITS
;
552 bits
|= EXTENT_FIRST_DELALLOC
;
554 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
557 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
558 prealloc
= alloc_extent_state(mask
);
563 spin_lock(&tree
->lock
);
565 cached
= *cached_state
;
568 *cached_state
= NULL
;
572 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
573 cached
->end
> start
) {
575 atomic_dec(&cached
->refs
);
580 free_extent_state(cached
);
583 * this search will find the extents that end after
586 node
= tree_search(tree
, start
);
589 state
= rb_entry(node
, struct extent_state
, rb_node
);
591 if (state
->start
> end
)
593 WARN_ON(state
->end
< start
);
594 last_end
= state
->end
;
596 /* the state doesn't have the wanted bits, go ahead */
597 if (!(state
->state
& bits
)) {
598 state
= next_state(state
);
603 * | ---- desired range ---- |
605 * | ------------- state -------------- |
607 * We need to split the extent we found, and may flip
608 * bits on second half.
610 * If the extent we found extends past our range, we
611 * just split and search again. It'll get split again
612 * the next time though.
614 * If the extent we found is inside our range, we clear
615 * the desired bit on it.
618 if (state
->start
< start
) {
619 prealloc
= alloc_extent_state_atomic(prealloc
);
621 err
= split_state(tree
, state
, prealloc
, start
);
623 extent_io_tree_panic(tree
, err
);
628 if (state
->end
<= end
) {
629 state
= clear_state_bit(tree
, state
, &bits
, wake
);
635 * | ---- desired range ---- |
637 * We need to split the extent, and clear the bit
640 if (state
->start
<= end
&& state
->end
> end
) {
641 prealloc
= alloc_extent_state_atomic(prealloc
);
643 err
= split_state(tree
, state
, prealloc
, end
+ 1);
645 extent_io_tree_panic(tree
, err
);
650 clear_state_bit(tree
, prealloc
, &bits
, wake
);
656 state
= clear_state_bit(tree
, state
, &bits
, wake
);
658 if (last_end
== (u64
)-1)
660 start
= last_end
+ 1;
661 if (start
<= end
&& state
&& !need_resched())
666 spin_unlock(&tree
->lock
);
668 free_extent_state(prealloc
);
675 spin_unlock(&tree
->lock
);
676 if (mask
& __GFP_WAIT
)
681 static void wait_on_state(struct extent_io_tree
*tree
,
682 struct extent_state
*state
)
683 __releases(tree
->lock
)
684 __acquires(tree
->lock
)
687 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
688 spin_unlock(&tree
->lock
);
690 spin_lock(&tree
->lock
);
691 finish_wait(&state
->wq
, &wait
);
695 * waits for one or more bits to clear on a range in the state tree.
696 * The range [start, end] is inclusive.
697 * The tree lock is taken by this function
699 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
702 struct extent_state
*state
;
703 struct rb_node
*node
;
705 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
707 spin_lock(&tree
->lock
);
711 * this search will find all the extents that end after
714 node
= tree_search(tree
, start
);
718 state
= rb_entry(node
, struct extent_state
, rb_node
);
720 if (state
->start
> end
)
723 if (state
->state
& bits
) {
724 start
= state
->start
;
725 atomic_inc(&state
->refs
);
726 wait_on_state(tree
, state
);
727 free_extent_state(state
);
730 start
= state
->end
+ 1;
735 cond_resched_lock(&tree
->lock
);
738 spin_unlock(&tree
->lock
);
741 static void set_state_bits(struct extent_io_tree
*tree
,
742 struct extent_state
*state
,
745 unsigned long bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
747 set_state_cb(tree
, state
, bits
);
748 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
749 u64 range
= state
->end
- state
->start
+ 1;
750 tree
->dirty_bytes
+= range
;
752 state
->state
|= bits_to_set
;
755 static void cache_state(struct extent_state
*state
,
756 struct extent_state
**cached_ptr
)
758 if (cached_ptr
&& !(*cached_ptr
)) {
759 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
)) {
761 atomic_inc(&state
->refs
);
767 * set some bits on a range in the tree. This may require allocations or
768 * sleeping, so the gfp mask is used to indicate what is allowed.
770 * If any of the exclusive bits are set, this will fail with -EEXIST if some
771 * part of the range already has the desired bits set. The start of the
772 * existing range is returned in failed_start in this case.
774 * [start, end] is inclusive This takes the tree lock.
777 static int __must_check
778 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
779 unsigned long bits
, unsigned long exclusive_bits
,
780 u64
*failed_start
, struct extent_state
**cached_state
,
783 struct extent_state
*state
;
784 struct extent_state
*prealloc
= NULL
;
785 struct rb_node
*node
;
790 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
792 bits
|= EXTENT_FIRST_DELALLOC
;
794 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
795 prealloc
= alloc_extent_state(mask
);
799 spin_lock(&tree
->lock
);
800 if (cached_state
&& *cached_state
) {
801 state
= *cached_state
;
802 if (state
->start
<= start
&& state
->end
> start
&&
804 node
= &state
->rb_node
;
809 * this search will find all the extents that end after
812 node
= tree_search(tree
, start
);
814 prealloc
= alloc_extent_state_atomic(prealloc
);
816 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
818 extent_io_tree_panic(tree
, err
);
823 state
= rb_entry(node
, struct extent_state
, rb_node
);
825 last_start
= state
->start
;
826 last_end
= state
->end
;
829 * | ---- desired range ---- |
832 * Just lock what we found and keep going
834 if (state
->start
== start
&& state
->end
<= end
) {
835 if (state
->state
& exclusive_bits
) {
836 *failed_start
= state
->start
;
841 set_state_bits(tree
, state
, &bits
);
842 cache_state(state
, cached_state
);
843 merge_state(tree
, state
);
844 if (last_end
== (u64
)-1)
846 start
= last_end
+ 1;
847 state
= next_state(state
);
848 if (start
< end
&& state
&& state
->start
== start
&&
855 * | ---- desired range ---- |
858 * | ------------- state -------------- |
860 * We need to split the extent we found, and may flip bits on
863 * If the extent we found extends past our
864 * range, we just split and search again. It'll get split
865 * again the next time though.
867 * If the extent we found is inside our range, we set the
870 if (state
->start
< start
) {
871 if (state
->state
& exclusive_bits
) {
872 *failed_start
= start
;
877 prealloc
= alloc_extent_state_atomic(prealloc
);
879 err
= split_state(tree
, state
, prealloc
, start
);
881 extent_io_tree_panic(tree
, err
);
886 if (state
->end
<= end
) {
887 set_state_bits(tree
, state
, &bits
);
888 cache_state(state
, cached_state
);
889 merge_state(tree
, state
);
890 if (last_end
== (u64
)-1)
892 start
= last_end
+ 1;
893 state
= next_state(state
);
894 if (start
< end
&& state
&& state
->start
== start
&&
901 * | ---- desired range ---- |
902 * | state | or | state |
904 * There's a hole, we need to insert something in it and
905 * ignore the extent we found.
907 if (state
->start
> start
) {
909 if (end
< last_start
)
912 this_end
= last_start
- 1;
914 prealloc
= alloc_extent_state_atomic(prealloc
);
918 * Avoid to free 'prealloc' if it can be merged with
921 err
= insert_state(tree
, prealloc
, start
, this_end
,
924 extent_io_tree_panic(tree
, err
);
926 cache_state(prealloc
, cached_state
);
928 start
= this_end
+ 1;
932 * | ---- desired range ---- |
934 * We need to split the extent, and set the bit
937 if (state
->start
<= end
&& state
->end
> end
) {
938 if (state
->state
& exclusive_bits
) {
939 *failed_start
= start
;
944 prealloc
= alloc_extent_state_atomic(prealloc
);
946 err
= split_state(tree
, state
, prealloc
, end
+ 1);
948 extent_io_tree_panic(tree
, err
);
950 set_state_bits(tree
, prealloc
, &bits
);
951 cache_state(prealloc
, cached_state
);
952 merge_state(tree
, prealloc
);
960 spin_unlock(&tree
->lock
);
962 free_extent_state(prealloc
);
969 spin_unlock(&tree
->lock
);
970 if (mask
& __GFP_WAIT
)
975 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
976 unsigned long bits
, u64
* failed_start
,
977 struct extent_state
**cached_state
, gfp_t mask
)
979 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
985 * convert_extent_bit - convert all bits in a given range from one bit to
987 * @tree: the io tree to search
988 * @start: the start offset in bytes
989 * @end: the end offset in bytes (inclusive)
990 * @bits: the bits to set in this range
991 * @clear_bits: the bits to clear in this range
992 * @cached_state: state that we're going to cache
993 * @mask: the allocation mask
995 * This will go through and set bits for the given range. If any states exist
996 * already in this range they are set with the given bit and cleared of the
997 * clear_bits. This is only meant to be used by things that are mergeable, ie
998 * converting from say DELALLOC to DIRTY. This is not meant to be used with
999 * boundary bits like LOCK.
1001 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1002 unsigned long bits
, unsigned long clear_bits
,
1003 struct extent_state
**cached_state
, gfp_t mask
)
1005 struct extent_state
*state
;
1006 struct extent_state
*prealloc
= NULL
;
1007 struct rb_node
*node
;
1012 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
1015 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
1016 prealloc
= alloc_extent_state(mask
);
1021 spin_lock(&tree
->lock
);
1022 if (cached_state
&& *cached_state
) {
1023 state
= *cached_state
;
1024 if (state
->start
<= start
&& state
->end
> start
&&
1026 node
= &state
->rb_node
;
1032 * this search will find all the extents that end after
1035 node
= tree_search(tree
, start
);
1037 prealloc
= alloc_extent_state_atomic(prealloc
);
1042 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
1045 extent_io_tree_panic(tree
, err
);
1048 state
= rb_entry(node
, struct extent_state
, rb_node
);
1050 last_start
= state
->start
;
1051 last_end
= state
->end
;
1054 * | ---- desired range ---- |
1057 * Just lock what we found and keep going
1059 if (state
->start
== start
&& state
->end
<= end
) {
1060 set_state_bits(tree
, state
, &bits
);
1061 cache_state(state
, cached_state
);
1062 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1063 if (last_end
== (u64
)-1)
1065 start
= last_end
+ 1;
1066 if (start
< end
&& state
&& state
->start
== start
&&
1073 * | ---- desired range ---- |
1076 * | ------------- state -------------- |
1078 * We need to split the extent we found, and may flip bits on
1081 * If the extent we found extends past our
1082 * range, we just split and search again. It'll get split
1083 * again the next time though.
1085 * If the extent we found is inside our range, we set the
1086 * desired bit on it.
1088 if (state
->start
< start
) {
1089 prealloc
= alloc_extent_state_atomic(prealloc
);
1094 err
= split_state(tree
, state
, prealloc
, start
);
1096 extent_io_tree_panic(tree
, err
);
1100 if (state
->end
<= end
) {
1101 set_state_bits(tree
, state
, &bits
);
1102 cache_state(state
, cached_state
);
1103 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1104 if (last_end
== (u64
)-1)
1106 start
= last_end
+ 1;
1107 if (start
< end
&& state
&& state
->start
== start
&&
1114 * | ---- desired range ---- |
1115 * | state | or | state |
1117 * There's a hole, we need to insert something in it and
1118 * ignore the extent we found.
1120 if (state
->start
> start
) {
1122 if (end
< last_start
)
1125 this_end
= last_start
- 1;
1127 prealloc
= alloc_extent_state_atomic(prealloc
);
1134 * Avoid to free 'prealloc' if it can be merged with
1137 err
= insert_state(tree
, prealloc
, start
, this_end
,
1140 extent_io_tree_panic(tree
, err
);
1141 cache_state(prealloc
, cached_state
);
1143 start
= this_end
+ 1;
1147 * | ---- desired range ---- |
1149 * We need to split the extent, and set the bit
1152 if (state
->start
<= end
&& state
->end
> end
) {
1153 prealloc
= alloc_extent_state_atomic(prealloc
);
1159 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1161 extent_io_tree_panic(tree
, err
);
1163 set_state_bits(tree
, prealloc
, &bits
);
1164 cache_state(prealloc
, cached_state
);
1165 clear_state_bit(tree
, prealloc
, &clear_bits
, 0);
1173 spin_unlock(&tree
->lock
);
1175 free_extent_state(prealloc
);
1182 spin_unlock(&tree
->lock
);
1183 if (mask
& __GFP_WAIT
)
1188 /* wrappers around set/clear extent bit */
1189 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1192 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, NULL
,
1196 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1197 unsigned long bits
, gfp_t mask
)
1199 return set_extent_bit(tree
, start
, end
, bits
, NULL
,
1203 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1204 unsigned long bits
, gfp_t mask
)
1206 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, mask
);
1209 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1210 struct extent_state
**cached_state
, gfp_t mask
)
1212 return set_extent_bit(tree
, start
, end
,
1213 EXTENT_DELALLOC
| EXTENT_UPTODATE
,
1214 NULL
, cached_state
, mask
);
1217 int set_extent_defrag(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1218 struct extent_state
**cached_state
, gfp_t mask
)
1220 return set_extent_bit(tree
, start
, end
,
1221 EXTENT_DELALLOC
| EXTENT_UPTODATE
| EXTENT_DEFRAG
,
1222 NULL
, cached_state
, mask
);
1225 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1228 return clear_extent_bit(tree
, start
, end
,
1229 EXTENT_DIRTY
| EXTENT_DELALLOC
|
1230 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
, mask
);
1233 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1236 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, NULL
,
1240 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1241 struct extent_state
**cached_state
, gfp_t mask
)
1243 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, NULL
,
1244 cached_state
, mask
);
1247 int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1248 struct extent_state
**cached_state
, gfp_t mask
)
1250 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0,
1251 cached_state
, mask
);
1255 * either insert or lock state struct between start and end use mask to tell
1256 * us if waiting is desired.
1258 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1259 unsigned long bits
, struct extent_state
**cached_state
)
1264 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
1265 EXTENT_LOCKED
, &failed_start
,
1266 cached_state
, GFP_NOFS
);
1267 if (err
== -EEXIST
) {
1268 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1269 start
= failed_start
;
1272 WARN_ON(start
> end
);
1277 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1279 return lock_extent_bits(tree
, start
, end
, 0, NULL
);
1282 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1287 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1288 &failed_start
, NULL
, GFP_NOFS
);
1289 if (err
== -EEXIST
) {
1290 if (failed_start
> start
)
1291 clear_extent_bit(tree
, start
, failed_start
- 1,
1292 EXTENT_LOCKED
, 1, 0, NULL
, GFP_NOFS
);
1298 int unlock_extent_cached(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1299 struct extent_state
**cached
, gfp_t mask
)
1301 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, cached
,
1305 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1307 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, NULL
,
1311 int extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1313 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1314 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1317 while (index
<= end_index
) {
1318 page
= find_get_page(inode
->i_mapping
, index
);
1319 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1320 clear_page_dirty_for_io(page
);
1321 page_cache_release(page
);
1327 int extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1329 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1330 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1333 while (index
<= end_index
) {
1334 page
= find_get_page(inode
->i_mapping
, index
);
1335 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1336 account_page_redirty(page
);
1337 __set_page_dirty_nobuffers(page
);
1338 page_cache_release(page
);
1345 * helper function to set both pages and extents in the tree writeback
1347 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1349 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1350 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1353 while (index
<= end_index
) {
1354 page
= find_get_page(tree
->mapping
, index
);
1355 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1356 set_page_writeback(page
);
1357 page_cache_release(page
);
1363 /* find the first state struct with 'bits' set after 'start', and
1364 * return it. tree->lock must be held. NULL will returned if
1365 * nothing was found after 'start'
1367 static struct extent_state
*
1368 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1369 u64 start
, unsigned long bits
)
1371 struct rb_node
*node
;
1372 struct extent_state
*state
;
1375 * this search will find all the extents that end after
1378 node
= tree_search(tree
, start
);
1383 state
= rb_entry(node
, struct extent_state
, rb_node
);
1384 if (state
->end
>= start
&& (state
->state
& bits
))
1387 node
= rb_next(node
);
1396 * find the first offset in the io tree with 'bits' set. zero is
1397 * returned if we find something, and *start_ret and *end_ret are
1398 * set to reflect the state struct that was found.
1400 * If nothing was found, 1 is returned. If found something, return 0.
1402 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1403 u64
*start_ret
, u64
*end_ret
, unsigned long bits
,
1404 struct extent_state
**cached_state
)
1406 struct extent_state
*state
;
1410 spin_lock(&tree
->lock
);
1411 if (cached_state
&& *cached_state
) {
1412 state
= *cached_state
;
1413 if (state
->end
== start
- 1 && state
->tree
) {
1414 n
= rb_next(&state
->rb_node
);
1416 state
= rb_entry(n
, struct extent_state
,
1418 if (state
->state
& bits
)
1422 free_extent_state(*cached_state
);
1423 *cached_state
= NULL
;
1426 free_extent_state(*cached_state
);
1427 *cached_state
= NULL
;
1430 state
= find_first_extent_bit_state(tree
, start
, bits
);
1433 cache_state(state
, cached_state
);
1434 *start_ret
= state
->start
;
1435 *end_ret
= state
->end
;
1439 spin_unlock(&tree
->lock
);
1444 * find a contiguous range of bytes in the file marked as delalloc, not
1445 * more than 'max_bytes'. start and end are used to return the range,
1447 * 1 is returned if we find something, 0 if nothing was in the tree
1449 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1450 u64
*start
, u64
*end
, u64 max_bytes
,
1451 struct extent_state
**cached_state
)
1453 struct rb_node
*node
;
1454 struct extent_state
*state
;
1455 u64 cur_start
= *start
;
1457 u64 total_bytes
= 0;
1459 spin_lock(&tree
->lock
);
1462 * this search will find all the extents that end after
1465 node
= tree_search(tree
, cur_start
);
1473 state
= rb_entry(node
, struct extent_state
, rb_node
);
1474 if (found
&& (state
->start
!= cur_start
||
1475 (state
->state
& EXTENT_BOUNDARY
))) {
1478 if (!(state
->state
& EXTENT_DELALLOC
)) {
1484 *start
= state
->start
;
1485 *cached_state
= state
;
1486 atomic_inc(&state
->refs
);
1490 cur_start
= state
->end
+ 1;
1491 node
= rb_next(node
);
1492 total_bytes
+= state
->end
- state
->start
+ 1;
1493 if (total_bytes
>= max_bytes
)
1499 spin_unlock(&tree
->lock
);
1503 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1504 struct page
*locked_page
,
1508 struct page
*pages
[16];
1509 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1510 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1511 unsigned long nr_pages
= end_index
- index
+ 1;
1514 if (index
== locked_page
->index
&& end_index
== index
)
1517 while (nr_pages
> 0) {
1518 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1519 min_t(unsigned long, nr_pages
,
1520 ARRAY_SIZE(pages
)), pages
);
1521 for (i
= 0; i
< ret
; i
++) {
1522 if (pages
[i
] != locked_page
)
1523 unlock_page(pages
[i
]);
1524 page_cache_release(pages
[i
]);
1532 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1533 struct page
*locked_page
,
1537 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1538 unsigned long start_index
= index
;
1539 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1540 unsigned long pages_locked
= 0;
1541 struct page
*pages
[16];
1542 unsigned long nrpages
;
1546 /* the caller is responsible for locking the start index */
1547 if (index
== locked_page
->index
&& index
== end_index
)
1550 /* skip the page at the start index */
1551 nrpages
= end_index
- index
+ 1;
1552 while (nrpages
> 0) {
1553 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1554 min_t(unsigned long,
1555 nrpages
, ARRAY_SIZE(pages
)), pages
);
1560 /* now we have an array of pages, lock them all */
1561 for (i
= 0; i
< ret
; i
++) {
1563 * the caller is taking responsibility for
1566 if (pages
[i
] != locked_page
) {
1567 lock_page(pages
[i
]);
1568 if (!PageDirty(pages
[i
]) ||
1569 pages
[i
]->mapping
!= inode
->i_mapping
) {
1571 unlock_page(pages
[i
]);
1572 page_cache_release(pages
[i
]);
1576 page_cache_release(pages
[i
]);
1585 if (ret
&& pages_locked
) {
1586 __unlock_for_delalloc(inode
, locked_page
,
1588 ((u64
)(start_index
+ pages_locked
- 1)) <<
1595 * find a contiguous range of bytes in the file marked as delalloc, not
1596 * more than 'max_bytes'. start and end are used to return the range,
1598 * 1 is returned if we find something, 0 if nothing was in the tree
1600 STATIC u64
find_lock_delalloc_range(struct inode
*inode
,
1601 struct extent_io_tree
*tree
,
1602 struct page
*locked_page
, u64
*start
,
1603 u64
*end
, u64 max_bytes
)
1608 struct extent_state
*cached_state
= NULL
;
1613 /* step one, find a bunch of delalloc bytes starting at start */
1614 delalloc_start
= *start
;
1616 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1617 max_bytes
, &cached_state
);
1618 if (!found
|| delalloc_end
<= *start
) {
1619 *start
= delalloc_start
;
1620 *end
= delalloc_end
;
1621 free_extent_state(cached_state
);
1626 * start comes from the offset of locked_page. We have to lock
1627 * pages in order, so we can't process delalloc bytes before
1630 if (delalloc_start
< *start
)
1631 delalloc_start
= *start
;
1634 * make sure to limit the number of pages we try to lock down
1636 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
)
1637 delalloc_end
= delalloc_start
+ max_bytes
- 1;
1639 /* step two, lock all the pages after the page that has start */
1640 ret
= lock_delalloc_pages(inode
, locked_page
,
1641 delalloc_start
, delalloc_end
);
1642 if (ret
== -EAGAIN
) {
1643 /* some of the pages are gone, lets avoid looping by
1644 * shortening the size of the delalloc range we're searching
1646 free_extent_state(cached_state
);
1648 max_bytes
= PAGE_CACHE_SIZE
;
1656 BUG_ON(ret
); /* Only valid values are 0 and -EAGAIN */
1658 /* step three, lock the state bits for the whole range */
1659 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, 0, &cached_state
);
1661 /* then test to make sure it is all still delalloc */
1662 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1663 EXTENT_DELALLOC
, 1, cached_state
);
1665 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1666 &cached_state
, GFP_NOFS
);
1667 __unlock_for_delalloc(inode
, locked_page
,
1668 delalloc_start
, delalloc_end
);
1672 free_extent_state(cached_state
);
1673 *start
= delalloc_start
;
1674 *end
= delalloc_end
;
1679 int extent_clear_unlock_delalloc(struct inode
*inode
, u64 start
, u64 end
,
1680 struct page
*locked_page
,
1681 unsigned long clear_bits
,
1682 unsigned long page_ops
)
1684 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
1686 struct page
*pages
[16];
1687 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1688 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1689 unsigned long nr_pages
= end_index
- index
+ 1;
1692 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, NULL
, GFP_NOFS
);
1696 while (nr_pages
> 0) {
1697 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1698 min_t(unsigned long,
1699 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1700 for (i
= 0; i
< ret
; i
++) {
1702 if (page_ops
& PAGE_SET_PRIVATE2
)
1703 SetPagePrivate2(pages
[i
]);
1705 if (pages
[i
] == locked_page
) {
1706 page_cache_release(pages
[i
]);
1709 if (page_ops
& PAGE_CLEAR_DIRTY
)
1710 clear_page_dirty_for_io(pages
[i
]);
1711 if (page_ops
& PAGE_SET_WRITEBACK
)
1712 set_page_writeback(pages
[i
]);
1713 if (page_ops
& PAGE_END_WRITEBACK
)
1714 end_page_writeback(pages
[i
]);
1715 if (page_ops
& PAGE_UNLOCK
)
1716 unlock_page(pages
[i
]);
1717 page_cache_release(pages
[i
]);
1727 * count the number of bytes in the tree that have a given bit(s)
1728 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1729 * cached. The total number found is returned.
1731 u64
count_range_bits(struct extent_io_tree
*tree
,
1732 u64
*start
, u64 search_end
, u64 max_bytes
,
1733 unsigned long bits
, int contig
)
1735 struct rb_node
*node
;
1736 struct extent_state
*state
;
1737 u64 cur_start
= *start
;
1738 u64 total_bytes
= 0;
1742 if (WARN_ON(search_end
<= cur_start
))
1745 spin_lock(&tree
->lock
);
1746 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1747 total_bytes
= tree
->dirty_bytes
;
1751 * this search will find all the extents that end after
1754 node
= tree_search(tree
, cur_start
);
1759 state
= rb_entry(node
, struct extent_state
, rb_node
);
1760 if (state
->start
> search_end
)
1762 if (contig
&& found
&& state
->start
> last
+ 1)
1764 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1765 total_bytes
+= min(search_end
, state
->end
) + 1 -
1766 max(cur_start
, state
->start
);
1767 if (total_bytes
>= max_bytes
)
1770 *start
= max(cur_start
, state
->start
);
1774 } else if (contig
&& found
) {
1777 node
= rb_next(node
);
1782 spin_unlock(&tree
->lock
);
1787 * set the private field for a given byte offset in the tree. If there isn't
1788 * an extent_state there already, this does nothing.
1790 static int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1792 struct rb_node
*node
;
1793 struct extent_state
*state
;
1796 spin_lock(&tree
->lock
);
1798 * this search will find all the extents that end after
1801 node
= tree_search(tree
, start
);
1806 state
= rb_entry(node
, struct extent_state
, rb_node
);
1807 if (state
->start
!= start
) {
1811 state
->private = private;
1813 spin_unlock(&tree
->lock
);
1817 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1819 struct rb_node
*node
;
1820 struct extent_state
*state
;
1823 spin_lock(&tree
->lock
);
1825 * this search will find all the extents that end after
1828 node
= tree_search(tree
, start
);
1833 state
= rb_entry(node
, struct extent_state
, rb_node
);
1834 if (state
->start
!= start
) {
1838 *private = state
->private;
1840 spin_unlock(&tree
->lock
);
1845 * searches a range in the state tree for a given mask.
1846 * If 'filled' == 1, this returns 1 only if every extent in the tree
1847 * has the bits set. Otherwise, 1 is returned if any bit in the
1848 * range is found set.
1850 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1851 unsigned long bits
, int filled
, struct extent_state
*cached
)
1853 struct extent_state
*state
= NULL
;
1854 struct rb_node
*node
;
1857 spin_lock(&tree
->lock
);
1858 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
1859 cached
->end
> start
)
1860 node
= &cached
->rb_node
;
1862 node
= tree_search(tree
, start
);
1863 while (node
&& start
<= end
) {
1864 state
= rb_entry(node
, struct extent_state
, rb_node
);
1866 if (filled
&& state
->start
> start
) {
1871 if (state
->start
> end
)
1874 if (state
->state
& bits
) {
1878 } else if (filled
) {
1883 if (state
->end
== (u64
)-1)
1886 start
= state
->end
+ 1;
1889 node
= rb_next(node
);
1896 spin_unlock(&tree
->lock
);
1901 * helper function to set a given page up to date if all the
1902 * extents in the tree for that page are up to date
1904 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
1906 u64 start
= page_offset(page
);
1907 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1908 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1909 SetPageUptodate(page
);
1913 * When IO fails, either with EIO or csum verification fails, we
1914 * try other mirrors that might have a good copy of the data. This
1915 * io_failure_record is used to record state as we go through all the
1916 * mirrors. If another mirror has good data, the page is set up to date
1917 * and things continue. If a good mirror can't be found, the original
1918 * bio end_io callback is called to indicate things have failed.
1920 struct io_failure_record
{
1925 unsigned long bio_flags
;
1931 static int free_io_failure(struct inode
*inode
, struct io_failure_record
*rec
,
1936 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
1938 set_state_private(failure_tree
, rec
->start
, 0);
1939 ret
= clear_extent_bits(failure_tree
, rec
->start
,
1940 rec
->start
+ rec
->len
- 1,
1941 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
1945 ret
= clear_extent_bits(&BTRFS_I(inode
)->io_tree
, rec
->start
,
1946 rec
->start
+ rec
->len
- 1,
1947 EXTENT_DAMAGED
, GFP_NOFS
);
1956 * this bypasses the standard btrfs submit functions deliberately, as
1957 * the standard behavior is to write all copies in a raid setup. here we only
1958 * want to write the one bad copy. so we do the mapping for ourselves and issue
1959 * submit_bio directly.
1960 * to avoid any synchronization issues, wait for the data after writing, which
1961 * actually prevents the read that triggered the error from finishing.
1962 * currently, there can be no more than two copies of every data bit. thus,
1963 * exactly one rewrite is required.
1965 int repair_io_failure(struct btrfs_fs_info
*fs_info
, u64 start
,
1966 u64 length
, u64 logical
, struct page
*page
,
1970 struct btrfs_device
*dev
;
1973 struct btrfs_bio
*bbio
= NULL
;
1974 struct btrfs_mapping_tree
*map_tree
= &fs_info
->mapping_tree
;
1977 ASSERT(!(fs_info
->sb
->s_flags
& MS_RDONLY
));
1978 BUG_ON(!mirror_num
);
1980 /* we can't repair anything in raid56 yet */
1981 if (btrfs_is_parity_mirror(map_tree
, logical
, length
, mirror_num
))
1984 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
1988 map_length
= length
;
1990 ret
= btrfs_map_block(fs_info
, WRITE
, logical
,
1991 &map_length
, &bbio
, mirror_num
);
1996 BUG_ON(mirror_num
!= bbio
->mirror_num
);
1997 sector
= bbio
->stripes
[mirror_num
-1].physical
>> 9;
1998 bio
->bi_sector
= sector
;
1999 dev
= bbio
->stripes
[mirror_num
-1].dev
;
2001 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2005 bio
->bi_bdev
= dev
->bdev
;
2006 bio_add_page(bio
, page
, length
, start
- page_offset(page
));
2008 if (btrfsic_submit_bio_wait(WRITE_SYNC
, bio
)) {
2009 /* try to remap that extent elsewhere? */
2011 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2015 printk_ratelimited_in_rcu(KERN_INFO
"btrfs read error corrected: ino %lu off %llu "
2016 "(dev %s sector %llu)\n", page
->mapping
->host
->i_ino
,
2017 start
, rcu_str_deref(dev
->name
), sector
);
2023 int repair_eb_io_failure(struct btrfs_root
*root
, struct extent_buffer
*eb
,
2026 u64 start
= eb
->start
;
2027 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2030 if (root
->fs_info
->sb
->s_flags
& MS_RDONLY
)
2033 for (i
= 0; i
< num_pages
; i
++) {
2034 struct page
*p
= extent_buffer_page(eb
, i
);
2035 ret
= repair_io_failure(root
->fs_info
, start
, PAGE_CACHE_SIZE
,
2036 start
, p
, mirror_num
);
2039 start
+= PAGE_CACHE_SIZE
;
2046 * each time an IO finishes, we do a fast check in the IO failure tree
2047 * to see if we need to process or clean up an io_failure_record
2049 static int clean_io_failure(u64 start
, struct page
*page
)
2052 u64 private_failure
;
2053 struct io_failure_record
*failrec
;
2054 struct inode
*inode
= page
->mapping
->host
;
2055 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2056 struct extent_state
*state
;
2062 ret
= count_range_bits(&BTRFS_I(inode
)->io_failure_tree
, &private,
2063 (u64
)-1, 1, EXTENT_DIRTY
, 0);
2067 ret
= get_state_private(&BTRFS_I(inode
)->io_failure_tree
, start
,
2072 failrec
= (struct io_failure_record
*)(unsigned long) private_failure
;
2073 BUG_ON(!failrec
->this_mirror
);
2075 if (failrec
->in_validation
) {
2076 /* there was no real error, just free the record */
2077 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2082 if (fs_info
->sb
->s_flags
& MS_RDONLY
)
2085 spin_lock(&BTRFS_I(inode
)->io_tree
.lock
);
2086 state
= find_first_extent_bit_state(&BTRFS_I(inode
)->io_tree
,
2089 spin_unlock(&BTRFS_I(inode
)->io_tree
.lock
);
2091 if (state
&& state
->start
<= failrec
->start
&&
2092 state
->end
>= failrec
->start
+ failrec
->len
- 1) {
2093 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2095 if (num_copies
> 1) {
2096 ret
= repair_io_failure(fs_info
, start
, failrec
->len
,
2097 failrec
->logical
, page
,
2098 failrec
->failed_mirror
);
2106 ret
= free_io_failure(inode
, failrec
, did_repair
);
2112 * this is a generic handler for readpage errors (default
2113 * readpage_io_failed_hook). if other copies exist, read those and write back
2114 * good data to the failed position. does not investigate in remapping the
2115 * failed extent elsewhere, hoping the device will be smart enough to do this as
2119 static int bio_readpage_error(struct bio
*failed_bio
, u64 phy_offset
,
2120 struct page
*page
, u64 start
, u64 end
,
2123 struct io_failure_record
*failrec
= NULL
;
2125 struct extent_map
*em
;
2126 struct inode
*inode
= page
->mapping
->host
;
2127 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2128 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2129 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2131 struct btrfs_io_bio
*btrfs_failed_bio
;
2132 struct btrfs_io_bio
*btrfs_bio
;
2138 BUG_ON(failed_bio
->bi_rw
& REQ_WRITE
);
2140 ret
= get_state_private(failure_tree
, start
, &private);
2142 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2145 failrec
->start
= start
;
2146 failrec
->len
= end
- start
+ 1;
2147 failrec
->this_mirror
= 0;
2148 failrec
->bio_flags
= 0;
2149 failrec
->in_validation
= 0;
2151 read_lock(&em_tree
->lock
);
2152 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2154 read_unlock(&em_tree
->lock
);
2159 if (em
->start
> start
|| em
->start
+ em
->len
< start
) {
2160 free_extent_map(em
);
2163 read_unlock(&em_tree
->lock
);
2169 logical
= start
- em
->start
;
2170 logical
= em
->block_start
+ logical
;
2171 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2172 logical
= em
->block_start
;
2173 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2174 extent_set_compress_type(&failrec
->bio_flags
,
2177 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2178 "len=%llu\n", logical
, start
, failrec
->len
);
2179 failrec
->logical
= logical
;
2180 free_extent_map(em
);
2182 /* set the bits in the private failure tree */
2183 ret
= set_extent_bits(failure_tree
, start
, end
,
2184 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
2186 ret
= set_state_private(failure_tree
, start
,
2187 (u64
)(unsigned long)failrec
);
2188 /* set the bits in the inode's tree */
2190 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
,
2197 failrec
= (struct io_failure_record
*)(unsigned long)private;
2198 pr_debug("bio_readpage_error: (found) logical=%llu, "
2199 "start=%llu, len=%llu, validation=%d\n",
2200 failrec
->logical
, failrec
->start
, failrec
->len
,
2201 failrec
->in_validation
);
2203 * when data can be on disk more than twice, add to failrec here
2204 * (e.g. with a list for failed_mirror) to make
2205 * clean_io_failure() clean all those errors at once.
2208 num_copies
= btrfs_num_copies(BTRFS_I(inode
)->root
->fs_info
,
2209 failrec
->logical
, failrec
->len
);
2210 if (num_copies
== 1) {
2212 * we only have a single copy of the data, so don't bother with
2213 * all the retry and error correction code that follows. no
2214 * matter what the error is, it is very likely to persist.
2216 pr_debug("bio_readpage_error: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
2217 num_copies
, failrec
->this_mirror
, failed_mirror
);
2218 free_io_failure(inode
, failrec
, 0);
2223 * there are two premises:
2224 * a) deliver good data to the caller
2225 * b) correct the bad sectors on disk
2227 if (failed_bio
->bi_vcnt
> 1) {
2229 * to fulfill b), we need to know the exact failing sectors, as
2230 * we don't want to rewrite any more than the failed ones. thus,
2231 * we need separate read requests for the failed bio
2233 * if the following BUG_ON triggers, our validation request got
2234 * merged. we need separate requests for our algorithm to work.
2236 BUG_ON(failrec
->in_validation
);
2237 failrec
->in_validation
= 1;
2238 failrec
->this_mirror
= failed_mirror
;
2239 read_mode
= READ_SYNC
| REQ_FAILFAST_DEV
;
2242 * we're ready to fulfill a) and b) alongside. get a good copy
2243 * of the failed sector and if we succeed, we have setup
2244 * everything for repair_io_failure to do the rest for us.
2246 if (failrec
->in_validation
) {
2247 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2248 failrec
->in_validation
= 0;
2249 failrec
->this_mirror
= 0;
2251 failrec
->failed_mirror
= failed_mirror
;
2252 failrec
->this_mirror
++;
2253 if (failrec
->this_mirror
== failed_mirror
)
2254 failrec
->this_mirror
++;
2255 read_mode
= READ_SYNC
;
2258 if (failrec
->this_mirror
> num_copies
) {
2259 pr_debug("bio_readpage_error: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
2260 num_copies
, failrec
->this_mirror
, failed_mirror
);
2261 free_io_failure(inode
, failrec
, 0);
2265 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2267 free_io_failure(inode
, failrec
, 0);
2270 bio
->bi_end_io
= failed_bio
->bi_end_io
;
2271 bio
->bi_sector
= failrec
->logical
>> 9;
2272 bio
->bi_bdev
= BTRFS_I(inode
)->root
->fs_info
->fs_devices
->latest_bdev
;
2275 btrfs_failed_bio
= btrfs_io_bio(failed_bio
);
2276 if (btrfs_failed_bio
->csum
) {
2277 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2278 u16 csum_size
= btrfs_super_csum_size(fs_info
->super_copy
);
2280 btrfs_bio
= btrfs_io_bio(bio
);
2281 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
2282 phy_offset
>>= inode
->i_sb
->s_blocksize_bits
;
2283 phy_offset
*= csum_size
;
2284 memcpy(btrfs_bio
->csum
, btrfs_failed_bio
->csum
+ phy_offset
,
2288 bio_add_page(bio
, page
, failrec
->len
, start
- page_offset(page
));
2290 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2291 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode
,
2292 failrec
->this_mirror
, num_copies
, failrec
->in_validation
);
2294 ret
= tree
->ops
->submit_bio_hook(inode
, read_mode
, bio
,
2295 failrec
->this_mirror
,
2296 failrec
->bio_flags
, 0);
2300 /* lots and lots of room for performance fixes in the end_bio funcs */
2302 int end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2304 int uptodate
= (err
== 0);
2305 struct extent_io_tree
*tree
;
2308 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2310 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
2311 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
2312 end
, NULL
, uptodate
);
2318 ClearPageUptodate(page
);
2325 * after a writepage IO is done, we need to:
2326 * clear the uptodate bits on error
2327 * clear the writeback bits in the extent tree for this IO
2328 * end_page_writeback if the page has no more pending IO
2330 * Scheduling is not allowed, so the extent state tree is expected
2331 * to have one and only one object corresponding to this IO.
2333 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
2335 struct bio_vec
*bvec
;
2336 struct extent_io_tree
*tree
;
2341 bio_for_each_segment_all(bvec
, bio
, i
) {
2342 struct page
*page
= bvec
->bv_page
;
2343 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2345 /* We always issue full-page reads, but if some block
2346 * in a page fails to read, blk_update_request() will
2347 * advance bv_offset and adjust bv_len to compensate.
2348 * Print a warning for nonzero offsets, and an error
2349 * if they don't add up to a full page. */
2350 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2351 printk("%s page write in btrfs with offset %u and length %u\n",
2352 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2353 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2354 bvec
->bv_offset
, bvec
->bv_len
);
2356 start
= page_offset(page
);
2357 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2359 if (end_extent_writepage(page
, err
, start
, end
))
2362 end_page_writeback(page
);
2369 endio_readpage_release_extent(struct extent_io_tree
*tree
, u64 start
, u64 len
,
2372 struct extent_state
*cached
= NULL
;
2373 u64 end
= start
+ len
- 1;
2375 if (uptodate
&& tree
->track_uptodate
)
2376 set_extent_uptodate(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2377 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2381 * after a readpage IO is done, we need to:
2382 * clear the uptodate bits on error
2383 * set the uptodate bits if things worked
2384 * set the page up to date if all extents in the tree are uptodate
2385 * clear the lock bit in the extent tree
2386 * unlock the page if there are no other extents locked for it
2388 * Scheduling is not allowed, so the extent state tree is expected
2389 * to have one and only one object corresponding to this IO.
2391 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
2393 struct bio_vec
*bvec
;
2394 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2395 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2396 struct extent_io_tree
*tree
;
2401 u64 extent_start
= 0;
2410 bio_for_each_segment_all(bvec
, bio
, i
) {
2411 struct page
*page
= bvec
->bv_page
;
2412 struct inode
*inode
= page
->mapping
->host
;
2414 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2415 "mirror=%lu\n", (u64
)bio
->bi_sector
, err
,
2416 io_bio
->mirror_num
);
2417 tree
= &BTRFS_I(inode
)->io_tree
;
2419 /* We always issue full-page reads, but if some block
2420 * in a page fails to read, blk_update_request() will
2421 * advance bv_offset and adjust bv_len to compensate.
2422 * Print a warning for nonzero offsets, and an error
2423 * if they don't add up to a full page. */
2424 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2425 printk("%s page read in btrfs with offset %u and length %u\n",
2426 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2427 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2428 bvec
->bv_offset
, bvec
->bv_len
);
2430 start
= page_offset(page
);
2431 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2434 mirror
= io_bio
->mirror_num
;
2435 if (likely(uptodate
&& tree
->ops
&&
2436 tree
->ops
->readpage_end_io_hook
)) {
2437 ret
= tree
->ops
->readpage_end_io_hook(io_bio
, offset
,
2443 clean_io_failure(start
, page
);
2446 if (likely(uptodate
))
2449 if (tree
->ops
&& tree
->ops
->readpage_io_failed_hook
) {
2450 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2452 test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
2456 * The generic bio_readpage_error handles errors the
2457 * following way: If possible, new read requests are
2458 * created and submitted and will end up in
2459 * end_bio_extent_readpage as well (if we're lucky, not
2460 * in the !uptodate case). In that case it returns 0 and
2461 * we just go on with the next page in our bio. If it
2462 * can't handle the error it will return -EIO and we
2463 * remain responsible for that page.
2465 ret
= bio_readpage_error(bio
, offset
, page
, start
, end
,
2469 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2476 if (likely(uptodate
)) {
2477 loff_t i_size
= i_size_read(inode
);
2478 pgoff_t end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2481 /* Zero out the end if this page straddles i_size */
2482 offset
= i_size
& (PAGE_CACHE_SIZE
-1);
2483 if (page
->index
== end_index
&& offset
)
2484 zero_user_segment(page
, offset
, PAGE_CACHE_SIZE
);
2485 SetPageUptodate(page
);
2487 ClearPageUptodate(page
);
2493 if (unlikely(!uptodate
)) {
2495 endio_readpage_release_extent(tree
,
2501 endio_readpage_release_extent(tree
, start
,
2502 end
- start
+ 1, 0);
2503 } else if (!extent_len
) {
2504 extent_start
= start
;
2505 extent_len
= end
+ 1 - start
;
2506 } else if (extent_start
+ extent_len
== start
) {
2507 extent_len
+= end
+ 1 - start
;
2509 endio_readpage_release_extent(tree
, extent_start
,
2510 extent_len
, uptodate
);
2511 extent_start
= start
;
2512 extent_len
= end
+ 1 - start
;
2517 endio_readpage_release_extent(tree
, extent_start
, extent_len
,
2520 io_bio
->end_io(io_bio
, err
);
2525 * this allocates from the btrfs_bioset. We're returning a bio right now
2526 * but you can call btrfs_io_bio for the appropriate container_of magic
2529 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
2532 struct btrfs_io_bio
*btrfs_bio
;
2535 bio
= bio_alloc_bioset(gfp_flags
, nr_vecs
, btrfs_bioset
);
2537 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
2538 while (!bio
&& (nr_vecs
/= 2)) {
2539 bio
= bio_alloc_bioset(gfp_flags
,
2540 nr_vecs
, btrfs_bioset
);
2545 bio
->bi_bdev
= bdev
;
2546 bio
->bi_sector
= first_sector
;
2547 btrfs_bio
= btrfs_io_bio(bio
);
2548 btrfs_bio
->csum
= NULL
;
2549 btrfs_bio
->csum_allocated
= NULL
;
2550 btrfs_bio
->end_io
= NULL
;
2555 struct bio
*btrfs_bio_clone(struct bio
*bio
, gfp_t gfp_mask
)
2557 return bio_clone_bioset(bio
, gfp_mask
, btrfs_bioset
);
2561 /* this also allocates from the btrfs_bioset */
2562 struct bio
*btrfs_io_bio_alloc(gfp_t gfp_mask
, unsigned int nr_iovecs
)
2564 struct btrfs_io_bio
*btrfs_bio
;
2567 bio
= bio_alloc_bioset(gfp_mask
, nr_iovecs
, btrfs_bioset
);
2569 btrfs_bio
= btrfs_io_bio(bio
);
2570 btrfs_bio
->csum
= NULL
;
2571 btrfs_bio
->csum_allocated
= NULL
;
2572 btrfs_bio
->end_io
= NULL
;
2578 static int __must_check
submit_one_bio(int rw
, struct bio
*bio
,
2579 int mirror_num
, unsigned long bio_flags
)
2582 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2583 struct page
*page
= bvec
->bv_page
;
2584 struct extent_io_tree
*tree
= bio
->bi_private
;
2587 start
= page_offset(page
) + bvec
->bv_offset
;
2589 bio
->bi_private
= NULL
;
2593 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
2594 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
2595 mirror_num
, bio_flags
, start
);
2597 btrfsic_submit_bio(rw
, bio
);
2599 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
2605 static int merge_bio(int rw
, struct extent_io_tree
*tree
, struct page
*page
,
2606 unsigned long offset
, size_t size
, struct bio
*bio
,
2607 unsigned long bio_flags
)
2610 if (tree
->ops
&& tree
->ops
->merge_bio_hook
)
2611 ret
= tree
->ops
->merge_bio_hook(rw
, page
, offset
, size
, bio
,
2618 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
2619 struct page
*page
, sector_t sector
,
2620 size_t size
, unsigned long offset
,
2621 struct block_device
*bdev
,
2622 struct bio
**bio_ret
,
2623 unsigned long max_pages
,
2624 bio_end_io_t end_io_func
,
2626 unsigned long prev_bio_flags
,
2627 unsigned long bio_flags
)
2633 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
2634 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2635 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
2637 if (bio_ret
&& *bio_ret
) {
2640 contig
= bio
->bi_sector
== sector
;
2642 contig
= bio_end_sector(bio
) == sector
;
2644 if (prev_bio_flags
!= bio_flags
|| !contig
||
2645 merge_bio(rw
, tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2646 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2647 ret
= submit_one_bio(rw
, bio
, mirror_num
,
2656 if (this_compressed
)
2659 nr
= bio_get_nr_vecs(bdev
);
2661 bio
= btrfs_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
2665 bio_add_page(bio
, page
, page_size
, offset
);
2666 bio
->bi_end_io
= end_io_func
;
2667 bio
->bi_private
= tree
;
2672 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
2677 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2680 if (!PagePrivate(page
)) {
2681 SetPagePrivate(page
);
2682 page_cache_get(page
);
2683 set_page_private(page
, (unsigned long)eb
);
2685 WARN_ON(page
->private != (unsigned long)eb
);
2689 void set_page_extent_mapped(struct page
*page
)
2691 if (!PagePrivate(page
)) {
2692 SetPagePrivate(page
);
2693 page_cache_get(page
);
2694 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2698 static struct extent_map
*
2699 __get_extent_map(struct inode
*inode
, struct page
*page
, size_t pg_offset
,
2700 u64 start
, u64 len
, get_extent_t
*get_extent
,
2701 struct extent_map
**em_cached
)
2703 struct extent_map
*em
;
2705 if (em_cached
&& *em_cached
) {
2707 if (em
->in_tree
&& start
>= em
->start
&&
2708 start
< extent_map_end(em
)) {
2709 atomic_inc(&em
->refs
);
2713 free_extent_map(em
);
2717 em
= get_extent(inode
, page
, pg_offset
, start
, len
, 0);
2718 if (em_cached
&& !IS_ERR_OR_NULL(em
)) {
2720 atomic_inc(&em
->refs
);
2726 * basic readpage implementation. Locked extent state structs are inserted
2727 * into the tree that are removed when the IO is done (by the end_io
2729 * XXX JDM: This needs looking at to ensure proper page locking
2731 static int __do_readpage(struct extent_io_tree
*tree
,
2733 get_extent_t
*get_extent
,
2734 struct extent_map
**em_cached
,
2735 struct bio
**bio
, int mirror_num
,
2736 unsigned long *bio_flags
, int rw
)
2738 struct inode
*inode
= page
->mapping
->host
;
2739 u64 start
= page_offset(page
);
2740 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2744 u64 last_byte
= i_size_read(inode
);
2748 struct extent_map
*em
;
2749 struct block_device
*bdev
;
2752 int parent_locked
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2753 size_t pg_offset
= 0;
2755 size_t disk_io_size
;
2756 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2757 unsigned long this_bio_flag
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2759 set_page_extent_mapped(page
);
2762 if (!PageUptodate(page
)) {
2763 if (cleancache_get_page(page
) == 0) {
2764 BUG_ON(blocksize
!= PAGE_SIZE
);
2765 unlock_extent(tree
, start
, end
);
2770 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
2772 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
2775 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
2776 userpage
= kmap_atomic(page
);
2777 memset(userpage
+ zero_offset
, 0, iosize
);
2778 flush_dcache_page(page
);
2779 kunmap_atomic(userpage
);
2782 while (cur
<= end
) {
2783 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2785 if (cur
>= last_byte
) {
2787 struct extent_state
*cached
= NULL
;
2789 iosize
= PAGE_CACHE_SIZE
- pg_offset
;
2790 userpage
= kmap_atomic(page
);
2791 memset(userpage
+ pg_offset
, 0, iosize
);
2792 flush_dcache_page(page
);
2793 kunmap_atomic(userpage
);
2794 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2797 unlock_extent_cached(tree
, cur
,
2802 em
= __get_extent_map(inode
, page
, pg_offset
, cur
,
2803 end
- cur
+ 1, get_extent
, em_cached
);
2804 if (IS_ERR_OR_NULL(em
)) {
2807 unlock_extent(tree
, cur
, end
);
2810 extent_offset
= cur
- em
->start
;
2811 BUG_ON(extent_map_end(em
) <= cur
);
2814 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2815 this_bio_flag
|= EXTENT_BIO_COMPRESSED
;
2816 extent_set_compress_type(&this_bio_flag
,
2820 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2821 cur_end
= min(extent_map_end(em
) - 1, end
);
2822 iosize
= ALIGN(iosize
, blocksize
);
2823 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2824 disk_io_size
= em
->block_len
;
2825 sector
= em
->block_start
>> 9;
2827 sector
= (em
->block_start
+ extent_offset
) >> 9;
2828 disk_io_size
= iosize
;
2831 block_start
= em
->block_start
;
2832 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2833 block_start
= EXTENT_MAP_HOLE
;
2834 free_extent_map(em
);
2837 /* we've found a hole, just zero and go on */
2838 if (block_start
== EXTENT_MAP_HOLE
) {
2840 struct extent_state
*cached
= NULL
;
2842 userpage
= kmap_atomic(page
);
2843 memset(userpage
+ pg_offset
, 0, iosize
);
2844 flush_dcache_page(page
);
2845 kunmap_atomic(userpage
);
2847 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2849 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2852 pg_offset
+= iosize
;
2855 /* the get_extent function already copied into the page */
2856 if (test_range_bit(tree
, cur
, cur_end
,
2857 EXTENT_UPTODATE
, 1, NULL
)) {
2858 check_page_uptodate(tree
, page
);
2860 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2862 pg_offset
+= iosize
;
2865 /* we have an inline extent but it didn't get marked up
2866 * to date. Error out
2868 if (block_start
== EXTENT_MAP_INLINE
) {
2871 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2873 pg_offset
+= iosize
;
2878 ret
= submit_extent_page(rw
, tree
, page
,
2879 sector
, disk_io_size
, pg_offset
,
2881 end_bio_extent_readpage
, mirror_num
,
2886 *bio_flags
= this_bio_flag
;
2890 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2893 pg_offset
+= iosize
;
2897 if (!PageError(page
))
2898 SetPageUptodate(page
);
2904 static inline void __do_contiguous_readpages(struct extent_io_tree
*tree
,
2905 struct page
*pages
[], int nr_pages
,
2907 get_extent_t
*get_extent
,
2908 struct extent_map
**em_cached
,
2909 struct bio
**bio
, int mirror_num
,
2910 unsigned long *bio_flags
, int rw
)
2912 struct inode
*inode
;
2913 struct btrfs_ordered_extent
*ordered
;
2916 inode
= pages
[0]->mapping
->host
;
2918 lock_extent(tree
, start
, end
);
2919 ordered
= btrfs_lookup_ordered_range(inode
, start
,
2923 unlock_extent(tree
, start
, end
);
2924 btrfs_start_ordered_extent(inode
, ordered
, 1);
2925 btrfs_put_ordered_extent(ordered
);
2928 for (index
= 0; index
< nr_pages
; index
++) {
2929 __do_readpage(tree
, pages
[index
], get_extent
, em_cached
, bio
,
2930 mirror_num
, bio_flags
, rw
);
2931 page_cache_release(pages
[index
]);
2935 static void __extent_readpages(struct extent_io_tree
*tree
,
2936 struct page
*pages
[],
2937 int nr_pages
, get_extent_t
*get_extent
,
2938 struct extent_map
**em_cached
,
2939 struct bio
**bio
, int mirror_num
,
2940 unsigned long *bio_flags
, int rw
)
2946 int first_index
= 0;
2948 for (index
= 0; index
< nr_pages
; index
++) {
2949 page_start
= page_offset(pages
[index
]);
2952 end
= start
+ PAGE_CACHE_SIZE
- 1;
2953 first_index
= index
;
2954 } else if (end
+ 1 == page_start
) {
2955 end
+= PAGE_CACHE_SIZE
;
2957 __do_contiguous_readpages(tree
, &pages
[first_index
],
2958 index
- first_index
, start
,
2959 end
, get_extent
, em_cached
,
2960 bio
, mirror_num
, bio_flags
,
2963 end
= start
+ PAGE_CACHE_SIZE
- 1;
2964 first_index
= index
;
2969 __do_contiguous_readpages(tree
, &pages
[first_index
],
2970 index
- first_index
, start
,
2971 end
, get_extent
, em_cached
, bio
,
2972 mirror_num
, bio_flags
, rw
);
2975 static int __extent_read_full_page(struct extent_io_tree
*tree
,
2977 get_extent_t
*get_extent
,
2978 struct bio
**bio
, int mirror_num
,
2979 unsigned long *bio_flags
, int rw
)
2981 struct inode
*inode
= page
->mapping
->host
;
2982 struct btrfs_ordered_extent
*ordered
;
2983 u64 start
= page_offset(page
);
2984 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2988 lock_extent(tree
, start
, end
);
2989 ordered
= btrfs_lookup_ordered_extent(inode
, start
);
2992 unlock_extent(tree
, start
, end
);
2993 btrfs_start_ordered_extent(inode
, ordered
, 1);
2994 btrfs_put_ordered_extent(ordered
);
2997 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, bio
, mirror_num
,
3002 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3003 get_extent_t
*get_extent
, int mirror_num
)
3005 struct bio
*bio
= NULL
;
3006 unsigned long bio_flags
= 0;
3009 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
3012 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3016 int extent_read_full_page_nolock(struct extent_io_tree
*tree
, struct page
*page
,
3017 get_extent_t
*get_extent
, int mirror_num
)
3019 struct bio
*bio
= NULL
;
3020 unsigned long bio_flags
= EXTENT_BIO_PARENT_LOCKED
;
3023 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, &bio
, mirror_num
,
3026 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3030 static noinline
void update_nr_written(struct page
*page
,
3031 struct writeback_control
*wbc
,
3032 unsigned long nr_written
)
3034 wbc
->nr_to_write
-= nr_written
;
3035 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
3036 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
3037 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
3041 * the writepage semantics are similar to regular writepage. extent
3042 * records are inserted to lock ranges in the tree, and as dirty areas
3043 * are found, they are marked writeback. Then the lock bits are removed
3044 * and the end_io handler clears the writeback ranges
3046 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
3049 struct inode
*inode
= page
->mapping
->host
;
3050 struct extent_page_data
*epd
= data
;
3051 struct extent_io_tree
*tree
= epd
->tree
;
3052 u64 start
= page_offset(page
);
3054 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
3058 u64 last_byte
= i_size_read(inode
);
3062 struct extent_state
*cached_state
= NULL
;
3063 struct extent_map
*em
;
3064 struct block_device
*bdev
;
3067 size_t pg_offset
= 0;
3069 loff_t i_size
= i_size_read(inode
);
3070 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
3076 unsigned long nr_written
= 0;
3077 bool fill_delalloc
= true;
3079 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3080 write_flags
= WRITE_SYNC
;
3082 write_flags
= WRITE
;
3084 trace___extent_writepage(page
, inode
, wbc
);
3086 WARN_ON(!PageLocked(page
));
3088 ClearPageError(page
);
3090 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
3091 if (page
->index
> end_index
||
3092 (page
->index
== end_index
&& !pg_offset
)) {
3093 page
->mapping
->a_ops
->invalidatepage(page
, 0, PAGE_CACHE_SIZE
);
3098 if (page
->index
== end_index
) {
3101 userpage
= kmap_atomic(page
);
3102 memset(userpage
+ pg_offset
, 0,
3103 PAGE_CACHE_SIZE
- pg_offset
);
3104 kunmap_atomic(userpage
);
3105 flush_dcache_page(page
);
3109 set_page_extent_mapped(page
);
3111 if (!tree
->ops
|| !tree
->ops
->fill_delalloc
)
3112 fill_delalloc
= false;
3114 delalloc_start
= start
;
3117 if (!epd
->extent_locked
&& fill_delalloc
) {
3118 u64 delalloc_to_write
= 0;
3120 * make sure the wbc mapping index is at least updated
3123 update_nr_written(page
, wbc
, 0);
3125 while (delalloc_end
< page_end
) {
3126 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
3131 if (nr_delalloc
== 0) {
3132 delalloc_start
= delalloc_end
+ 1;
3135 ret
= tree
->ops
->fill_delalloc(inode
, page
,
3140 /* File system has been set read-only */
3146 * delalloc_end is already one less than the total
3147 * length, so we don't subtract one from
3150 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3153 delalloc_start
= delalloc_end
+ 1;
3155 if (wbc
->nr_to_write
< delalloc_to_write
) {
3158 if (delalloc_to_write
< thresh
* 2)
3159 thresh
= delalloc_to_write
;
3160 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3164 /* did the fill delalloc function already unlock and start
3170 * we've unlocked the page, so we can't update
3171 * the mapping's writeback index, just update
3174 wbc
->nr_to_write
-= nr_written
;
3178 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3179 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3182 /* Fixup worker will requeue */
3184 wbc
->pages_skipped
++;
3186 redirty_page_for_writepage(wbc
, page
);
3187 update_nr_written(page
, wbc
, nr_written
);
3195 * we don't want to touch the inode after unlocking the page,
3196 * so we update the mapping writeback index now
3198 update_nr_written(page
, wbc
, nr_written
+ 1);
3201 if (last_byte
<= start
) {
3202 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3203 tree
->ops
->writepage_end_io_hook(page
, start
,
3208 blocksize
= inode
->i_sb
->s_blocksize
;
3210 while (cur
<= end
) {
3211 if (cur
>= last_byte
) {
3212 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3213 tree
->ops
->writepage_end_io_hook(page
, cur
,
3217 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
3219 if (IS_ERR_OR_NULL(em
)) {
3224 extent_offset
= cur
- em
->start
;
3225 BUG_ON(extent_map_end(em
) <= cur
);
3227 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
3228 iosize
= ALIGN(iosize
, blocksize
);
3229 sector
= (em
->block_start
+ extent_offset
) >> 9;
3231 block_start
= em
->block_start
;
3232 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3233 free_extent_map(em
);
3237 * compressed and inline extents are written through other
3240 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3241 block_start
== EXTENT_MAP_INLINE
) {
3243 * end_io notification does not happen here for
3244 * compressed extents
3246 if (!compressed
&& tree
->ops
&&
3247 tree
->ops
->writepage_end_io_hook
)
3248 tree
->ops
->writepage_end_io_hook(page
, cur
,
3251 else if (compressed
) {
3252 /* we don't want to end_page_writeback on
3253 * a compressed extent. this happens
3260 pg_offset
+= iosize
;
3263 /* leave this out until we have a page_mkwrite call */
3264 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
3265 EXTENT_DIRTY
, 0, NULL
)) {
3267 pg_offset
+= iosize
;
3271 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
3272 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
3280 unsigned long max_nr
= end_index
+ 1;
3282 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3283 if (!PageWriteback(page
)) {
3284 printk(KERN_ERR
"btrfs warning page %lu not "
3285 "writeback, cur %llu end %llu\n",
3286 page
->index
, cur
, end
);
3289 ret
= submit_extent_page(write_flags
, tree
, page
,
3290 sector
, iosize
, pg_offset
,
3291 bdev
, &epd
->bio
, max_nr
,
3292 end_bio_extent_writepage
,
3298 pg_offset
+= iosize
;
3303 /* make sure the mapping tag for page dirty gets cleared */
3304 set_page_writeback(page
);
3305 end_page_writeback(page
);
3311 /* drop our reference on any cached states */
3312 free_extent_state(cached_state
);
3316 static int eb_wait(void *word
)
3322 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3324 wait_on_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
, eb_wait
,
3325 TASK_UNINTERRUPTIBLE
);
3328 static int lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3329 struct btrfs_fs_info
*fs_info
,
3330 struct extent_page_data
*epd
)
3332 unsigned long i
, num_pages
;
3336 if (!btrfs_try_tree_write_lock(eb
)) {
3338 flush_write_bio(epd
);
3339 btrfs_tree_lock(eb
);
3342 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3343 btrfs_tree_unlock(eb
);
3347 flush_write_bio(epd
);
3351 wait_on_extent_buffer_writeback(eb
);
3352 btrfs_tree_lock(eb
);
3353 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3355 btrfs_tree_unlock(eb
);
3360 * We need to do this to prevent races in people who check if the eb is
3361 * under IO since we can end up having no IO bits set for a short period
3364 spin_lock(&eb
->refs_lock
);
3365 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3366 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3367 spin_unlock(&eb
->refs_lock
);
3368 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3369 __percpu_counter_add(&fs_info
->dirty_metadata_bytes
,
3371 fs_info
->dirty_metadata_batch
);
3374 spin_unlock(&eb
->refs_lock
);
3377 btrfs_tree_unlock(eb
);
3382 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3383 for (i
= 0; i
< num_pages
; i
++) {
3384 struct page
*p
= extent_buffer_page(eb
, i
);
3386 if (!trylock_page(p
)) {
3388 flush_write_bio(epd
);
3398 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3400 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3401 smp_mb__after_clear_bit();
3402 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3405 static void end_bio_extent_buffer_writepage(struct bio
*bio
, int err
)
3407 struct bio_vec
*bvec
;
3408 struct extent_buffer
*eb
;
3411 bio_for_each_segment_all(bvec
, bio
, i
) {
3412 struct page
*page
= bvec
->bv_page
;
3414 eb
= (struct extent_buffer
*)page
->private;
3416 done
= atomic_dec_and_test(&eb
->io_pages
);
3418 if (err
|| test_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
)) {
3419 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3420 ClearPageUptodate(page
);
3424 end_page_writeback(page
);
3429 end_extent_buffer_writeback(eb
);
3435 static int write_one_eb(struct extent_buffer
*eb
,
3436 struct btrfs_fs_info
*fs_info
,
3437 struct writeback_control
*wbc
,
3438 struct extent_page_data
*epd
)
3440 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3441 u64 offset
= eb
->start
;
3442 unsigned long i
, num_pages
;
3443 unsigned long bio_flags
= 0;
3444 int rw
= (epd
->sync_io
? WRITE_SYNC
: WRITE
) | REQ_META
;
3447 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3448 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3449 atomic_set(&eb
->io_pages
, num_pages
);
3450 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3451 bio_flags
= EXTENT_BIO_TREE_LOG
;
3453 for (i
= 0; i
< num_pages
; i
++) {
3454 struct page
*p
= extent_buffer_page(eb
, i
);
3456 clear_page_dirty_for_io(p
);
3457 set_page_writeback(p
);
3458 ret
= submit_extent_page(rw
, eb
->tree
, p
, offset
>> 9,
3459 PAGE_CACHE_SIZE
, 0, bdev
, &epd
->bio
,
3460 -1, end_bio_extent_buffer_writepage
,
3461 0, epd
->bio_flags
, bio_flags
);
3462 epd
->bio_flags
= bio_flags
;
3464 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3466 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3467 end_extent_buffer_writeback(eb
);
3471 offset
+= PAGE_CACHE_SIZE
;
3472 update_nr_written(p
, wbc
, 1);
3476 if (unlikely(ret
)) {
3477 for (; i
< num_pages
; i
++) {
3478 struct page
*p
= extent_buffer_page(eb
, i
);
3486 int btree_write_cache_pages(struct address_space
*mapping
,
3487 struct writeback_control
*wbc
)
3489 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3490 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3491 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3492 struct extent_page_data epd
= {
3496 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3501 int nr_to_write_done
= 0;
3502 struct pagevec pvec
;
3505 pgoff_t end
; /* Inclusive */
3509 pagevec_init(&pvec
, 0);
3510 if (wbc
->range_cyclic
) {
3511 index
= mapping
->writeback_index
; /* Start from prev offset */
3514 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3515 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3518 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3519 tag
= PAGECACHE_TAG_TOWRITE
;
3521 tag
= PAGECACHE_TAG_DIRTY
;
3523 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3524 tag_pages_for_writeback(mapping
, index
, end
);
3525 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3526 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3527 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3531 for (i
= 0; i
< nr_pages
; i
++) {
3532 struct page
*page
= pvec
.pages
[i
];
3534 if (!PagePrivate(page
))
3537 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3542 spin_lock(&mapping
->private_lock
);
3543 if (!PagePrivate(page
)) {
3544 spin_unlock(&mapping
->private_lock
);
3548 eb
= (struct extent_buffer
*)page
->private;
3551 * Shouldn't happen and normally this would be a BUG_ON
3552 * but no sense in crashing the users box for something
3553 * we can survive anyway.
3556 spin_unlock(&mapping
->private_lock
);
3560 if (eb
== prev_eb
) {
3561 spin_unlock(&mapping
->private_lock
);
3565 ret
= atomic_inc_not_zero(&eb
->refs
);
3566 spin_unlock(&mapping
->private_lock
);
3571 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3573 free_extent_buffer(eb
);
3577 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3580 free_extent_buffer(eb
);
3583 free_extent_buffer(eb
);
3586 * the filesystem may choose to bump up nr_to_write.
3587 * We have to make sure to honor the new nr_to_write
3590 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3592 pagevec_release(&pvec
);
3595 if (!scanned
&& !done
) {
3597 * We hit the last page and there is more work to be done: wrap
3598 * back to the start of the file
3604 flush_write_bio(&epd
);
3609 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3610 * @mapping: address space structure to write
3611 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3612 * @writepage: function called for each page
3613 * @data: data passed to writepage function
3615 * If a page is already under I/O, write_cache_pages() skips it, even
3616 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3617 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3618 * and msync() need to guarantee that all the data which was dirty at the time
3619 * the call was made get new I/O started against them. If wbc->sync_mode is
3620 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3621 * existing IO to complete.
3623 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
3624 struct address_space
*mapping
,
3625 struct writeback_control
*wbc
,
3626 writepage_t writepage
, void *data
,
3627 void (*flush_fn
)(void *))
3629 struct inode
*inode
= mapping
->host
;
3632 int nr_to_write_done
= 0;
3633 struct pagevec pvec
;
3636 pgoff_t end
; /* Inclusive */
3641 * We have to hold onto the inode so that ordered extents can do their
3642 * work when the IO finishes. The alternative to this is failing to add
3643 * an ordered extent if the igrab() fails there and that is a huge pain
3644 * to deal with, so instead just hold onto the inode throughout the
3645 * writepages operation. If it fails here we are freeing up the inode
3646 * anyway and we'd rather not waste our time writing out stuff that is
3647 * going to be truncated anyway.
3652 pagevec_init(&pvec
, 0);
3653 if (wbc
->range_cyclic
) {
3654 index
= mapping
->writeback_index
; /* Start from prev offset */
3657 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3658 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3661 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3662 tag
= PAGECACHE_TAG_TOWRITE
;
3664 tag
= PAGECACHE_TAG_DIRTY
;
3666 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3667 tag_pages_for_writeback(mapping
, index
, end
);
3668 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3669 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3670 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3674 for (i
= 0; i
< nr_pages
; i
++) {
3675 struct page
*page
= pvec
.pages
[i
];
3678 * At this point we hold neither mapping->tree_lock nor
3679 * lock on the page itself: the page may be truncated or
3680 * invalidated (changing page->mapping to NULL), or even
3681 * swizzled back from swapper_space to tmpfs file
3684 if (!trylock_page(page
)) {
3689 if (unlikely(page
->mapping
!= mapping
)) {
3694 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3700 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
3701 if (PageWriteback(page
))
3703 wait_on_page_writeback(page
);
3706 if (PageWriteback(page
) ||
3707 !clear_page_dirty_for_io(page
)) {
3712 ret
= (*writepage
)(page
, wbc
, data
);
3714 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
3722 * the filesystem may choose to bump up nr_to_write.
3723 * We have to make sure to honor the new nr_to_write
3726 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3728 pagevec_release(&pvec
);
3731 if (!scanned
&& !done
) {
3733 * We hit the last page and there is more work to be done: wrap
3734 * back to the start of the file
3740 btrfs_add_delayed_iput(inode
);
3744 static void flush_epd_write_bio(struct extent_page_data
*epd
)
3753 ret
= submit_one_bio(rw
, epd
->bio
, 0, epd
->bio_flags
);
3754 BUG_ON(ret
< 0); /* -ENOMEM */
3759 static noinline
void flush_write_bio(void *data
)
3761 struct extent_page_data
*epd
= data
;
3762 flush_epd_write_bio(epd
);
3765 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3766 get_extent_t
*get_extent
,
3767 struct writeback_control
*wbc
)
3770 struct extent_page_data epd
= {
3773 .get_extent
= get_extent
,
3775 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3779 ret
= __extent_writepage(page
, wbc
, &epd
);
3781 flush_epd_write_bio(&epd
);
3785 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
3786 u64 start
, u64 end
, get_extent_t
*get_extent
,
3790 struct address_space
*mapping
= inode
->i_mapping
;
3792 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
3795 struct extent_page_data epd
= {
3798 .get_extent
= get_extent
,
3800 .sync_io
= mode
== WB_SYNC_ALL
,
3803 struct writeback_control wbc_writepages
= {
3805 .nr_to_write
= nr_pages
* 2,
3806 .range_start
= start
,
3807 .range_end
= end
+ 1,
3810 while (start
<= end
) {
3811 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
3812 if (clear_page_dirty_for_io(page
))
3813 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
3815 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3816 tree
->ops
->writepage_end_io_hook(page
, start
,
3817 start
+ PAGE_CACHE_SIZE
- 1,
3821 page_cache_release(page
);
3822 start
+= PAGE_CACHE_SIZE
;
3825 flush_epd_write_bio(&epd
);
3829 int extent_writepages(struct extent_io_tree
*tree
,
3830 struct address_space
*mapping
,
3831 get_extent_t
*get_extent
,
3832 struct writeback_control
*wbc
)
3835 struct extent_page_data epd
= {
3838 .get_extent
= get_extent
,
3840 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3844 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
3845 __extent_writepage
, &epd
,
3847 flush_epd_write_bio(&epd
);
3851 int extent_readpages(struct extent_io_tree
*tree
,
3852 struct address_space
*mapping
,
3853 struct list_head
*pages
, unsigned nr_pages
,
3854 get_extent_t get_extent
)
3856 struct bio
*bio
= NULL
;
3858 unsigned long bio_flags
= 0;
3859 struct page
*pagepool
[16];
3861 struct extent_map
*em_cached
= NULL
;
3864 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
3865 page
= list_entry(pages
->prev
, struct page
, lru
);
3867 prefetchw(&page
->flags
);
3868 list_del(&page
->lru
);
3869 if (add_to_page_cache_lru(page
, mapping
,
3870 page
->index
, GFP_NOFS
)) {
3871 page_cache_release(page
);
3875 pagepool
[nr
++] = page
;
3876 if (nr
< ARRAY_SIZE(pagepool
))
3878 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
3879 &bio
, 0, &bio_flags
, READ
);
3883 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
3884 &bio
, 0, &bio_flags
, READ
);
3887 free_extent_map(em_cached
);
3889 BUG_ON(!list_empty(pages
));
3891 return submit_one_bio(READ
, bio
, 0, bio_flags
);
3896 * basic invalidatepage code, this waits on any locked or writeback
3897 * ranges corresponding to the page, and then deletes any extent state
3898 * records from the tree
3900 int extent_invalidatepage(struct extent_io_tree
*tree
,
3901 struct page
*page
, unsigned long offset
)
3903 struct extent_state
*cached_state
= NULL
;
3904 u64 start
= page_offset(page
);
3905 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3906 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
3908 start
+= ALIGN(offset
, blocksize
);
3912 lock_extent_bits(tree
, start
, end
, 0, &cached_state
);
3913 wait_on_page_writeback(page
);
3914 clear_extent_bit(tree
, start
, end
,
3915 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
3916 EXTENT_DO_ACCOUNTING
,
3917 1, 1, &cached_state
, GFP_NOFS
);
3922 * a helper for releasepage, this tests for areas of the page that
3923 * are locked or under IO and drops the related state bits if it is safe
3926 static int try_release_extent_state(struct extent_map_tree
*map
,
3927 struct extent_io_tree
*tree
,
3928 struct page
*page
, gfp_t mask
)
3930 u64 start
= page_offset(page
);
3931 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3934 if (test_range_bit(tree
, start
, end
,
3935 EXTENT_IOBITS
, 0, NULL
))
3938 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
3941 * at this point we can safely clear everything except the
3942 * locked bit and the nodatasum bit
3944 ret
= clear_extent_bit(tree
, start
, end
,
3945 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
3948 /* if clear_extent_bit failed for enomem reasons,
3949 * we can't allow the release to continue.
3960 * a helper for releasepage. As long as there are no locked extents
3961 * in the range corresponding to the page, both state records and extent
3962 * map records are removed
3964 int try_release_extent_mapping(struct extent_map_tree
*map
,
3965 struct extent_io_tree
*tree
, struct page
*page
,
3968 struct extent_map
*em
;
3969 u64 start
= page_offset(page
);
3970 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3972 if ((mask
& __GFP_WAIT
) &&
3973 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
3975 while (start
<= end
) {
3976 len
= end
- start
+ 1;
3977 write_lock(&map
->lock
);
3978 em
= lookup_extent_mapping(map
, start
, len
);
3980 write_unlock(&map
->lock
);
3983 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
3984 em
->start
!= start
) {
3985 write_unlock(&map
->lock
);
3986 free_extent_map(em
);
3989 if (!test_range_bit(tree
, em
->start
,
3990 extent_map_end(em
) - 1,
3991 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
3993 remove_extent_mapping(map
, em
);
3994 /* once for the rb tree */
3995 free_extent_map(em
);
3997 start
= extent_map_end(em
);
3998 write_unlock(&map
->lock
);
4001 free_extent_map(em
);
4004 return try_release_extent_state(map
, tree
, page
, mask
);
4008 * helper function for fiemap, which doesn't want to see any holes.
4009 * This maps until we find something past 'last'
4011 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
4014 get_extent_t
*get_extent
)
4016 u64 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
4017 struct extent_map
*em
;
4024 len
= last
- offset
;
4027 len
= ALIGN(len
, sectorsize
);
4028 em
= get_extent(inode
, NULL
, 0, offset
, len
, 0);
4029 if (IS_ERR_OR_NULL(em
))
4032 /* if this isn't a hole return it */
4033 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
4034 em
->block_start
!= EXTENT_MAP_HOLE
) {
4038 /* this is a hole, advance to the next extent */
4039 offset
= extent_map_end(em
);
4040 free_extent_map(em
);
4047 static noinline
int count_ext_ref(u64 inum
, u64 offset
, u64 root_id
, void *ctx
)
4049 unsigned long cnt
= *((unsigned long *)ctx
);
4052 *((unsigned long *)ctx
) = cnt
;
4054 /* Now we're sure that the extent is shared. */
4060 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4061 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
4065 u64 max
= start
+ len
;
4069 u64 last_for_get_extent
= 0;
4071 u64 isize
= i_size_read(inode
);
4072 struct btrfs_key found_key
;
4073 struct extent_map
*em
= NULL
;
4074 struct extent_state
*cached_state
= NULL
;
4075 struct btrfs_path
*path
;
4076 struct btrfs_file_extent_item
*item
;
4081 unsigned long emflags
;
4086 path
= btrfs_alloc_path();
4089 path
->leave_spinning
= 1;
4091 start
= ALIGN(start
, BTRFS_I(inode
)->root
->sectorsize
);
4092 len
= ALIGN(len
, BTRFS_I(inode
)->root
->sectorsize
);
4095 * lookup the last file extent. We're not using i_size here
4096 * because there might be preallocation past i_size
4098 ret
= btrfs_lookup_file_extent(NULL
, BTRFS_I(inode
)->root
,
4099 path
, btrfs_ino(inode
), -1, 0);
4101 btrfs_free_path(path
);
4106 item
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
4107 struct btrfs_file_extent_item
);
4108 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
4109 found_type
= btrfs_key_type(&found_key
);
4111 /* No extents, but there might be delalloc bits */
4112 if (found_key
.objectid
!= btrfs_ino(inode
) ||
4113 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
4114 /* have to trust i_size as the end */
4116 last_for_get_extent
= isize
;
4119 * remember the start of the last extent. There are a
4120 * bunch of different factors that go into the length of the
4121 * extent, so its much less complex to remember where it started
4123 last
= found_key
.offset
;
4124 last_for_get_extent
= last
+ 1;
4126 btrfs_release_path(path
);
4129 * we might have some extents allocated but more delalloc past those
4130 * extents. so, we trust isize unless the start of the last extent is
4135 last_for_get_extent
= isize
;
4138 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1, 0,
4141 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4151 u64 offset_in_extent
= 0;
4153 /* break if the extent we found is outside the range */
4154 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4158 * get_extent may return an extent that starts before our
4159 * requested range. We have to make sure the ranges
4160 * we return to fiemap always move forward and don't
4161 * overlap, so adjust the offsets here
4163 em_start
= max(em
->start
, off
);
4166 * record the offset from the start of the extent
4167 * for adjusting the disk offset below. Only do this if the
4168 * extent isn't compressed since our in ram offset may be past
4169 * what we have actually allocated on disk.
4171 if (!test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4172 offset_in_extent
= em_start
- em
->start
;
4173 em_end
= extent_map_end(em
);
4174 em_len
= em_end
- em_start
;
4175 emflags
= em
->flags
;
4180 * bump off for our next call to get_extent
4182 off
= extent_map_end(em
);
4186 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4188 flags
|= FIEMAP_EXTENT_LAST
;
4189 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4190 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4191 FIEMAP_EXTENT_NOT_ALIGNED
);
4192 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4193 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4194 FIEMAP_EXTENT_UNKNOWN
);
4196 unsigned long ref_cnt
= 0;
4198 disko
= em
->block_start
+ offset_in_extent
;
4201 * As btrfs supports shared space, this information
4202 * can be exported to userspace tools via
4203 * flag FIEMAP_EXTENT_SHARED.
4205 ret
= iterate_inodes_from_logical(
4207 BTRFS_I(inode
)->root
->fs_info
,
4208 path
, count_ext_ref
, &ref_cnt
);
4209 if (ret
< 0 && ret
!= -ENOENT
)
4213 flags
|= FIEMAP_EXTENT_SHARED
;
4215 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4216 flags
|= FIEMAP_EXTENT_ENCODED
;
4218 free_extent_map(em
);
4220 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4221 (last
== (u64
)-1 && isize
<= em_end
)) {
4222 flags
|= FIEMAP_EXTENT_LAST
;
4226 /* now scan forward to see if this is really the last extent. */
4227 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4234 flags
|= FIEMAP_EXTENT_LAST
;
4237 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
4243 free_extent_map(em
);
4245 btrfs_free_path(path
);
4246 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4247 &cached_state
, GFP_NOFS
);
4251 static void __free_extent_buffer(struct extent_buffer
*eb
)
4253 btrfs_leak_debug_del(&eb
->leak_list
);
4254 kmem_cache_free(extent_buffer_cache
, eb
);
4257 static int extent_buffer_under_io(struct extent_buffer
*eb
)
4259 return (atomic_read(&eb
->io_pages
) ||
4260 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4261 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4265 * Helper for releasing extent buffer page.
4267 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
,
4268 unsigned long start_idx
)
4270 unsigned long index
;
4271 unsigned long num_pages
;
4273 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4275 BUG_ON(extent_buffer_under_io(eb
));
4277 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4278 index
= start_idx
+ num_pages
;
4279 if (start_idx
>= index
)
4284 page
= extent_buffer_page(eb
, index
);
4285 if (page
&& mapped
) {
4286 spin_lock(&page
->mapping
->private_lock
);
4288 * We do this since we'll remove the pages after we've
4289 * removed the eb from the radix tree, so we could race
4290 * and have this page now attached to the new eb. So
4291 * only clear page_private if it's still connected to
4294 if (PagePrivate(page
) &&
4295 page
->private == (unsigned long)eb
) {
4296 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4297 BUG_ON(PageDirty(page
));
4298 BUG_ON(PageWriteback(page
));
4300 * We need to make sure we haven't be attached
4303 ClearPagePrivate(page
);
4304 set_page_private(page
, 0);
4305 /* One for the page private */
4306 page_cache_release(page
);
4308 spin_unlock(&page
->mapping
->private_lock
);
4312 /* One for when we alloced the page */
4313 page_cache_release(page
);
4315 } while (index
!= start_idx
);
4319 * Helper for releasing the extent buffer.
4321 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4323 btrfs_release_extent_buffer_page(eb
, 0);
4324 __free_extent_buffer(eb
);
4327 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
4332 struct extent_buffer
*eb
= NULL
;
4334 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
4341 rwlock_init(&eb
->lock
);
4342 atomic_set(&eb
->write_locks
, 0);
4343 atomic_set(&eb
->read_locks
, 0);
4344 atomic_set(&eb
->blocking_readers
, 0);
4345 atomic_set(&eb
->blocking_writers
, 0);
4346 atomic_set(&eb
->spinning_readers
, 0);
4347 atomic_set(&eb
->spinning_writers
, 0);
4348 eb
->lock_nested
= 0;
4349 init_waitqueue_head(&eb
->write_lock_wq
);
4350 init_waitqueue_head(&eb
->read_lock_wq
);
4352 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4354 spin_lock_init(&eb
->refs_lock
);
4355 atomic_set(&eb
->refs
, 1);
4356 atomic_set(&eb
->io_pages
, 0);
4359 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4361 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4362 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4363 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4368 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4372 struct extent_buffer
*new;
4373 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4375 new = __alloc_extent_buffer(NULL
, src
->start
, src
->len
, GFP_NOFS
);
4379 for (i
= 0; i
< num_pages
; i
++) {
4380 p
= alloc_page(GFP_NOFS
);
4382 btrfs_release_extent_buffer(new);
4385 attach_extent_buffer_page(new, p
);
4386 WARN_ON(PageDirty(p
));
4391 copy_extent_buffer(new, src
, 0, 0, src
->len
);
4392 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4393 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4398 struct extent_buffer
*alloc_dummy_extent_buffer(u64 start
, unsigned long len
)
4400 struct extent_buffer
*eb
;
4401 unsigned long num_pages
= num_extent_pages(0, len
);
4404 eb
= __alloc_extent_buffer(NULL
, start
, len
, GFP_NOFS
);
4408 for (i
= 0; i
< num_pages
; i
++) {
4409 eb
->pages
[i
] = alloc_page(GFP_NOFS
);
4413 set_extent_buffer_uptodate(eb
);
4414 btrfs_set_header_nritems(eb
, 0);
4415 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4420 __free_page(eb
->pages
[i
- 1]);
4421 __free_extent_buffer(eb
);
4425 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4428 /* the ref bit is tricky. We have to make sure it is set
4429 * if we have the buffer dirty. Otherwise the
4430 * code to free a buffer can end up dropping a dirty
4433 * Once the ref bit is set, it won't go away while the
4434 * buffer is dirty or in writeback, and it also won't
4435 * go away while we have the reference count on the
4438 * We can't just set the ref bit without bumping the
4439 * ref on the eb because free_extent_buffer might
4440 * see the ref bit and try to clear it. If this happens
4441 * free_extent_buffer might end up dropping our original
4442 * ref by mistake and freeing the page before we are able
4443 * to add one more ref.
4445 * So bump the ref count first, then set the bit. If someone
4446 * beat us to it, drop the ref we added.
4448 refs
= atomic_read(&eb
->refs
);
4449 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4452 spin_lock(&eb
->refs_lock
);
4453 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4454 atomic_inc(&eb
->refs
);
4455 spin_unlock(&eb
->refs_lock
);
4458 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
)
4460 unsigned long num_pages
, i
;
4462 check_buffer_tree_ref(eb
);
4464 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4465 for (i
= 0; i
< num_pages
; i
++) {
4466 struct page
*p
= extent_buffer_page(eb
, i
);
4467 mark_page_accessed(p
);
4471 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
4474 struct extent_buffer
*eb
;
4477 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4478 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4480 mark_extent_buffer_accessed(eb
);
4488 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
4489 u64 start
, unsigned long len
)
4491 unsigned long num_pages
= num_extent_pages(start
, len
);
4493 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
4494 struct extent_buffer
*eb
;
4495 struct extent_buffer
*exists
= NULL
;
4497 struct address_space
*mapping
= tree
->mapping
;
4502 eb
= find_extent_buffer(tree
, start
);
4506 eb
= __alloc_extent_buffer(tree
, start
, len
, GFP_NOFS
);
4510 for (i
= 0; i
< num_pages
; i
++, index
++) {
4511 p
= find_or_create_page(mapping
, index
, GFP_NOFS
);
4515 spin_lock(&mapping
->private_lock
);
4516 if (PagePrivate(p
)) {
4518 * We could have already allocated an eb for this page
4519 * and attached one so lets see if we can get a ref on
4520 * the existing eb, and if we can we know it's good and
4521 * we can just return that one, else we know we can just
4522 * overwrite page->private.
4524 exists
= (struct extent_buffer
*)p
->private;
4525 if (atomic_inc_not_zero(&exists
->refs
)) {
4526 spin_unlock(&mapping
->private_lock
);
4528 page_cache_release(p
);
4529 mark_extent_buffer_accessed(exists
);
4534 * Do this so attach doesn't complain and we need to
4535 * drop the ref the old guy had.
4537 ClearPagePrivate(p
);
4538 WARN_ON(PageDirty(p
));
4539 page_cache_release(p
);
4541 attach_extent_buffer_page(eb
, p
);
4542 spin_unlock(&mapping
->private_lock
);
4543 WARN_ON(PageDirty(p
));
4544 mark_page_accessed(p
);
4546 if (!PageUptodate(p
))
4550 * see below about how we avoid a nasty race with release page
4551 * and why we unlock later
4555 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4557 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
4561 spin_lock(&tree
->buffer_lock
);
4562 ret
= radix_tree_insert(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
, eb
);
4563 spin_unlock(&tree
->buffer_lock
);
4564 radix_tree_preload_end();
4565 if (ret
== -EEXIST
) {
4566 exists
= find_extent_buffer(tree
, start
);
4572 /* add one reference for the tree */
4573 check_buffer_tree_ref(eb
);
4576 * there is a race where release page may have
4577 * tried to find this extent buffer in the radix
4578 * but failed. It will tell the VM it is safe to
4579 * reclaim the, and it will clear the page private bit.
4580 * We must make sure to set the page private bit properly
4581 * after the extent buffer is in the radix tree so
4582 * it doesn't get lost
4584 SetPageChecked(eb
->pages
[0]);
4585 for (i
= 1; i
< num_pages
; i
++) {
4586 p
= extent_buffer_page(eb
, i
);
4587 ClearPageChecked(p
);
4590 unlock_page(eb
->pages
[0]);
4594 for (i
= 0; i
< num_pages
; i
++) {
4596 unlock_page(eb
->pages
[i
]);
4599 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
4600 btrfs_release_extent_buffer(eb
);
4604 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
4606 struct extent_buffer
*eb
=
4607 container_of(head
, struct extent_buffer
, rcu_head
);
4609 __free_extent_buffer(eb
);
4612 /* Expects to have eb->eb_lock already held */
4613 static int release_extent_buffer(struct extent_buffer
*eb
)
4615 WARN_ON(atomic_read(&eb
->refs
) == 0);
4616 if (atomic_dec_and_test(&eb
->refs
)) {
4617 if (test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
)) {
4618 spin_unlock(&eb
->refs_lock
);
4620 struct extent_io_tree
*tree
= eb
->tree
;
4622 spin_unlock(&eb
->refs_lock
);
4624 spin_lock(&tree
->buffer_lock
);
4625 radix_tree_delete(&tree
->buffer
,
4626 eb
->start
>> PAGE_CACHE_SHIFT
);
4627 spin_unlock(&tree
->buffer_lock
);
4630 /* Should be safe to release our pages at this point */
4631 btrfs_release_extent_buffer_page(eb
, 0);
4632 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
4635 spin_unlock(&eb
->refs_lock
);
4640 void free_extent_buffer(struct extent_buffer
*eb
)
4648 refs
= atomic_read(&eb
->refs
);
4651 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
4656 spin_lock(&eb
->refs_lock
);
4657 if (atomic_read(&eb
->refs
) == 2 &&
4658 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
4659 atomic_dec(&eb
->refs
);
4661 if (atomic_read(&eb
->refs
) == 2 &&
4662 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
4663 !extent_buffer_under_io(eb
) &&
4664 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4665 atomic_dec(&eb
->refs
);
4668 * I know this is terrible, but it's temporary until we stop tracking
4669 * the uptodate bits and such for the extent buffers.
4671 release_extent_buffer(eb
);
4674 void free_extent_buffer_stale(struct extent_buffer
*eb
)
4679 spin_lock(&eb
->refs_lock
);
4680 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
4682 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
4683 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4684 atomic_dec(&eb
->refs
);
4685 release_extent_buffer(eb
);
4688 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
4691 unsigned long num_pages
;
4694 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4696 for (i
= 0; i
< num_pages
; i
++) {
4697 page
= extent_buffer_page(eb
, i
);
4698 if (!PageDirty(page
))
4702 WARN_ON(!PagePrivate(page
));
4704 clear_page_dirty_for_io(page
);
4705 spin_lock_irq(&page
->mapping
->tree_lock
);
4706 if (!PageDirty(page
)) {
4707 radix_tree_tag_clear(&page
->mapping
->page_tree
,
4709 PAGECACHE_TAG_DIRTY
);
4711 spin_unlock_irq(&page
->mapping
->tree_lock
);
4712 ClearPageError(page
);
4715 WARN_ON(atomic_read(&eb
->refs
) == 0);
4718 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
4721 unsigned long num_pages
;
4724 check_buffer_tree_ref(eb
);
4726 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
4728 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4729 WARN_ON(atomic_read(&eb
->refs
) == 0);
4730 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
4732 for (i
= 0; i
< num_pages
; i
++)
4733 set_page_dirty(extent_buffer_page(eb
, i
));
4737 int clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
4741 unsigned long num_pages
;
4743 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4744 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4745 for (i
= 0; i
< num_pages
; i
++) {
4746 page
= extent_buffer_page(eb
, i
);
4748 ClearPageUptodate(page
);
4753 int set_extent_buffer_uptodate(struct extent_buffer
*eb
)
4757 unsigned long num_pages
;
4759 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4760 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4761 for (i
= 0; i
< num_pages
; i
++) {
4762 page
= extent_buffer_page(eb
, i
);
4763 SetPageUptodate(page
);
4768 int extent_buffer_uptodate(struct extent_buffer
*eb
)
4770 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4773 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
4774 struct extent_buffer
*eb
, u64 start
, int wait
,
4775 get_extent_t
*get_extent
, int mirror_num
)
4778 unsigned long start_i
;
4782 int locked_pages
= 0;
4783 int all_uptodate
= 1;
4784 unsigned long num_pages
;
4785 unsigned long num_reads
= 0;
4786 struct bio
*bio
= NULL
;
4787 unsigned long bio_flags
= 0;
4789 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
4793 WARN_ON(start
< eb
->start
);
4794 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
4795 (eb
->start
>> PAGE_CACHE_SHIFT
);
4800 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4801 for (i
= start_i
; i
< num_pages
; i
++) {
4802 page
= extent_buffer_page(eb
, i
);
4803 if (wait
== WAIT_NONE
) {
4804 if (!trylock_page(page
))
4810 if (!PageUptodate(page
)) {
4817 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4821 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
4822 eb
->read_mirror
= 0;
4823 atomic_set(&eb
->io_pages
, num_reads
);
4824 for (i
= start_i
; i
< num_pages
; i
++) {
4825 page
= extent_buffer_page(eb
, i
);
4826 if (!PageUptodate(page
)) {
4827 ClearPageError(page
);
4828 err
= __extent_read_full_page(tree
, page
,
4830 mirror_num
, &bio_flags
,
4840 err
= submit_one_bio(READ
| REQ_META
, bio
, mirror_num
,
4846 if (ret
|| wait
!= WAIT_COMPLETE
)
4849 for (i
= start_i
; i
< num_pages
; i
++) {
4850 page
= extent_buffer_page(eb
, i
);
4851 wait_on_page_locked(page
);
4852 if (!PageUptodate(page
))
4860 while (locked_pages
> 0) {
4861 page
= extent_buffer_page(eb
, i
);
4869 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
4870 unsigned long start
,
4877 char *dst
= (char *)dstv
;
4878 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4879 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4881 WARN_ON(start
> eb
->len
);
4882 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4884 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4887 page
= extent_buffer_page(eb
, i
);
4889 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4890 kaddr
= page_address(page
);
4891 memcpy(dst
, kaddr
+ offset
, cur
);
4900 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
4901 unsigned long min_len
, char **map
,
4902 unsigned long *map_start
,
4903 unsigned long *map_len
)
4905 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
4908 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4909 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4910 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
4917 offset
= start_offset
;
4921 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
4924 if (start
+ min_len
> eb
->len
) {
4925 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
4927 eb
->start
, eb
->len
, start
, min_len
);
4931 p
= extent_buffer_page(eb
, i
);
4932 kaddr
= page_address(p
);
4933 *map
= kaddr
+ offset
;
4934 *map_len
= PAGE_CACHE_SIZE
- offset
;
4938 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
4939 unsigned long start
,
4946 char *ptr
= (char *)ptrv
;
4947 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4948 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4951 WARN_ON(start
> eb
->len
);
4952 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4954 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4957 page
= extent_buffer_page(eb
, i
);
4959 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4961 kaddr
= page_address(page
);
4962 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
4974 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
4975 unsigned long start
, unsigned long len
)
4981 char *src
= (char *)srcv
;
4982 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4983 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4985 WARN_ON(start
> eb
->len
);
4986 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4988 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4991 page
= extent_buffer_page(eb
, i
);
4992 WARN_ON(!PageUptodate(page
));
4994 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
4995 kaddr
= page_address(page
);
4996 memcpy(kaddr
+ offset
, src
, cur
);
5005 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
5006 unsigned long start
, unsigned long len
)
5012 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5013 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5015 WARN_ON(start
> eb
->len
);
5016 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5018 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5021 page
= extent_buffer_page(eb
, i
);
5022 WARN_ON(!PageUptodate(page
));
5024 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
5025 kaddr
= page_address(page
);
5026 memset(kaddr
+ offset
, c
, cur
);
5034 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
5035 unsigned long dst_offset
, unsigned long src_offset
,
5038 u64 dst_len
= dst
->len
;
5043 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5044 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5046 WARN_ON(src
->len
!= dst_len
);
5048 offset
= (start_offset
+ dst_offset
) &
5049 (PAGE_CACHE_SIZE
- 1);
5052 page
= extent_buffer_page(dst
, i
);
5053 WARN_ON(!PageUptodate(page
));
5055 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
5057 kaddr
= page_address(page
);
5058 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
5067 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
5069 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
5070 return distance
< len
;
5073 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
5074 unsigned long dst_off
, unsigned long src_off
,
5077 char *dst_kaddr
= page_address(dst_page
);
5079 int must_memmove
= 0;
5081 if (dst_page
!= src_page
) {
5082 src_kaddr
= page_address(src_page
);
5084 src_kaddr
= dst_kaddr
;
5085 if (areas_overlap(src_off
, dst_off
, len
))
5090 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5092 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5095 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5096 unsigned long src_offset
, unsigned long len
)
5099 size_t dst_off_in_page
;
5100 size_t src_off_in_page
;
5101 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5102 unsigned long dst_i
;
5103 unsigned long src_i
;
5105 if (src_offset
+ len
> dst
->len
) {
5106 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5107 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
5110 if (dst_offset
+ len
> dst
->len
) {
5111 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5112 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
5117 dst_off_in_page
= (start_offset
+ dst_offset
) &
5118 (PAGE_CACHE_SIZE
- 1);
5119 src_off_in_page
= (start_offset
+ src_offset
) &
5120 (PAGE_CACHE_SIZE
- 1);
5122 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5123 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
5125 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
5127 cur
= min_t(unsigned long, cur
,
5128 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
5130 copy_pages(extent_buffer_page(dst
, dst_i
),
5131 extent_buffer_page(dst
, src_i
),
5132 dst_off_in_page
, src_off_in_page
, cur
);
5140 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5141 unsigned long src_offset
, unsigned long len
)
5144 size_t dst_off_in_page
;
5145 size_t src_off_in_page
;
5146 unsigned long dst_end
= dst_offset
+ len
- 1;
5147 unsigned long src_end
= src_offset
+ len
- 1;
5148 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5149 unsigned long dst_i
;
5150 unsigned long src_i
;
5152 if (src_offset
+ len
> dst
->len
) {
5153 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5154 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
5157 if (dst_offset
+ len
> dst
->len
) {
5158 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5159 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
5162 if (dst_offset
< src_offset
) {
5163 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5167 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
5168 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
5170 dst_off_in_page
= (start_offset
+ dst_end
) &
5171 (PAGE_CACHE_SIZE
- 1);
5172 src_off_in_page
= (start_offset
+ src_end
) &
5173 (PAGE_CACHE_SIZE
- 1);
5175 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5176 cur
= min(cur
, dst_off_in_page
+ 1);
5177 copy_pages(extent_buffer_page(dst
, dst_i
),
5178 extent_buffer_page(dst
, src_i
),
5179 dst_off_in_page
- cur
+ 1,
5180 src_off_in_page
- cur
+ 1, cur
);
5188 int try_release_extent_buffer(struct page
*page
)
5190 struct extent_buffer
*eb
;
5193 * We need to make sure noboody is attaching this page to an eb right
5196 spin_lock(&page
->mapping
->private_lock
);
5197 if (!PagePrivate(page
)) {
5198 spin_unlock(&page
->mapping
->private_lock
);
5202 eb
= (struct extent_buffer
*)page
->private;
5206 * This is a little awful but should be ok, we need to make sure that
5207 * the eb doesn't disappear out from under us while we're looking at
5210 spin_lock(&eb
->refs_lock
);
5211 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
5212 spin_unlock(&eb
->refs_lock
);
5213 spin_unlock(&page
->mapping
->private_lock
);
5216 spin_unlock(&page
->mapping
->private_lock
);
5219 * If tree ref isn't set then we know the ref on this eb is a real ref,
5220 * so just return, this page will likely be freed soon anyway.
5222 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
5223 spin_unlock(&eb
->refs_lock
);
5227 return release_extent_buffer(eb
);