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(tree, start, end) \
81 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
82 static inline void __btrfs_debug_check_extent_io_range(const char *caller
,
83 struct extent_io_tree
*tree
, u64 start
, u64 end
)
91 inode
= tree
->mapping
->host
;
92 isize
= i_size_read(inode
);
93 if (end
>= PAGE_SIZE
&& (end
% 2) == 0 && end
!= isize
- 1) {
94 printk_ratelimited(KERN_DEBUG
95 "btrfs: %s: ino %llu isize %llu odd range [%llu,%llu]\n",
96 caller
, btrfs_ino(inode
), isize
, start
, end
);
100 #define btrfs_leak_debug_add(new, head) do {} while (0)
101 #define btrfs_leak_debug_del(entry) do {} while (0)
102 #define btrfs_leak_debug_check() do {} while (0)
103 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
106 #define BUFFER_LRU_MAX 64
111 struct rb_node rb_node
;
114 struct extent_page_data
{
116 struct extent_io_tree
*tree
;
117 get_extent_t
*get_extent
;
118 unsigned long bio_flags
;
120 /* tells writepage not to lock the state bits for this range
121 * it still does the unlocking
123 unsigned int extent_locked
:1;
125 /* tells the submit_bio code to use a WRITE_SYNC */
126 unsigned int sync_io
:1;
129 static noinline
void flush_write_bio(void *data
);
130 static inline struct btrfs_fs_info
*
131 tree_fs_info(struct extent_io_tree
*tree
)
135 return btrfs_sb(tree
->mapping
->host
->i_sb
);
138 int __init
extent_io_init(void)
140 extent_state_cache
= kmem_cache_create("btrfs_extent_state",
141 sizeof(struct extent_state
), 0,
142 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
143 if (!extent_state_cache
)
146 extent_buffer_cache
= kmem_cache_create("btrfs_extent_buffer",
147 sizeof(struct extent_buffer
), 0,
148 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
149 if (!extent_buffer_cache
)
150 goto free_state_cache
;
152 btrfs_bioset
= bioset_create(BIO_POOL_SIZE
,
153 offsetof(struct btrfs_io_bio
, bio
));
155 goto free_buffer_cache
;
157 if (bioset_integrity_create(btrfs_bioset
, BIO_POOL_SIZE
))
163 bioset_free(btrfs_bioset
);
167 kmem_cache_destroy(extent_buffer_cache
);
168 extent_buffer_cache
= NULL
;
171 kmem_cache_destroy(extent_state_cache
);
172 extent_state_cache
= NULL
;
176 void extent_io_exit(void)
178 btrfs_leak_debug_check();
181 * Make sure all delayed rcu free are flushed before we
185 if (extent_state_cache
)
186 kmem_cache_destroy(extent_state_cache
);
187 if (extent_buffer_cache
)
188 kmem_cache_destroy(extent_buffer_cache
);
190 bioset_free(btrfs_bioset
);
193 void extent_io_tree_init(struct extent_io_tree
*tree
,
194 struct address_space
*mapping
)
196 tree
->state
= RB_ROOT
;
197 INIT_RADIX_TREE(&tree
->buffer
, GFP_ATOMIC
);
199 tree
->dirty_bytes
= 0;
200 spin_lock_init(&tree
->lock
);
201 spin_lock_init(&tree
->buffer_lock
);
202 tree
->mapping
= mapping
;
205 static struct extent_state
*alloc_extent_state(gfp_t mask
)
207 struct extent_state
*state
;
209 state
= kmem_cache_alloc(extent_state_cache
, mask
);
215 btrfs_leak_debug_add(&state
->leak_list
, &states
);
216 atomic_set(&state
->refs
, 1);
217 init_waitqueue_head(&state
->wq
);
218 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
222 void free_extent_state(struct extent_state
*state
)
226 if (atomic_dec_and_test(&state
->refs
)) {
227 WARN_ON(state
->tree
);
228 btrfs_leak_debug_del(&state
->leak_list
);
229 trace_free_extent_state(state
, _RET_IP_
);
230 kmem_cache_free(extent_state_cache
, state
);
234 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
235 struct rb_node
*node
,
236 struct rb_node
***p_in
,
237 struct rb_node
**parent_in
)
239 struct rb_node
**p
= &root
->rb_node
;
240 struct rb_node
*parent
= NULL
;
241 struct tree_entry
*entry
;
243 if (p_in
&& parent_in
) {
251 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
253 if (offset
< entry
->start
)
255 else if (offset
> entry
->end
)
262 rb_link_node(node
, parent
, p
);
263 rb_insert_color(node
, root
);
267 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
268 struct rb_node
**prev_ret
,
269 struct rb_node
**next_ret
,
270 struct rb_node
***p_ret
,
271 struct rb_node
**parent_ret
)
273 struct rb_root
*root
= &tree
->state
;
274 struct rb_node
**n
= &root
->rb_node
;
275 struct rb_node
*prev
= NULL
;
276 struct rb_node
*orig_prev
= NULL
;
277 struct tree_entry
*entry
;
278 struct tree_entry
*prev_entry
= NULL
;
282 entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
285 if (offset
< entry
->start
)
287 else if (offset
> entry
->end
)
300 while (prev
&& offset
> prev_entry
->end
) {
301 prev
= rb_next(prev
);
302 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
309 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
310 while (prev
&& offset
< prev_entry
->start
) {
311 prev
= rb_prev(prev
);
312 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
319 static inline struct rb_node
*
320 tree_search_for_insert(struct extent_io_tree
*tree
,
322 struct rb_node
***p_ret
,
323 struct rb_node
**parent_ret
)
325 struct rb_node
*prev
= NULL
;
328 ret
= __etree_search(tree
, offset
, &prev
, NULL
, p_ret
, parent_ret
);
334 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
337 return tree_search_for_insert(tree
, offset
, NULL
, NULL
);
340 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
341 struct extent_state
*other
)
343 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
344 tree
->ops
->merge_extent_hook(tree
->mapping
->host
, new,
349 * utility function to look for merge candidates inside a given range.
350 * Any extents with matching state are merged together into a single
351 * extent in the tree. Extents with EXTENT_IO in their state field
352 * are not merged because the end_io handlers need to be able to do
353 * operations on them without sleeping (or doing allocations/splits).
355 * This should be called with the tree lock held.
357 static void merge_state(struct extent_io_tree
*tree
,
358 struct extent_state
*state
)
360 struct extent_state
*other
;
361 struct rb_node
*other_node
;
363 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
366 other_node
= rb_prev(&state
->rb_node
);
368 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
369 if (other
->end
== state
->start
- 1 &&
370 other
->state
== state
->state
) {
371 merge_cb(tree
, state
, other
);
372 state
->start
= other
->start
;
374 rb_erase(&other
->rb_node
, &tree
->state
);
375 free_extent_state(other
);
378 other_node
= rb_next(&state
->rb_node
);
380 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
381 if (other
->start
== state
->end
+ 1 &&
382 other
->state
== state
->state
) {
383 merge_cb(tree
, state
, other
);
384 state
->end
= other
->end
;
386 rb_erase(&other
->rb_node
, &tree
->state
);
387 free_extent_state(other
);
392 static void set_state_cb(struct extent_io_tree
*tree
,
393 struct extent_state
*state
, unsigned long *bits
)
395 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
396 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
, bits
);
399 static void clear_state_cb(struct extent_io_tree
*tree
,
400 struct extent_state
*state
, unsigned long *bits
)
402 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
403 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
, bits
);
406 static void set_state_bits(struct extent_io_tree
*tree
,
407 struct extent_state
*state
, unsigned long *bits
);
410 * insert an extent_state struct into the tree. 'bits' are set on the
411 * struct before it is inserted.
413 * This may return -EEXIST if the extent is already there, in which case the
414 * state struct is freed.
416 * The tree lock is not taken internally. This is a utility function and
417 * probably isn't what you want to call (see set/clear_extent_bit).
419 static int insert_state(struct extent_io_tree
*tree
,
420 struct extent_state
*state
, u64 start
, u64 end
,
422 struct rb_node
**parent
,
425 struct rb_node
*node
;
428 WARN(1, KERN_ERR
"btrfs end < start %llu %llu\n",
430 state
->start
= start
;
433 set_state_bits(tree
, state
, bits
);
435 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
, p
, parent
);
437 struct extent_state
*found
;
438 found
= rb_entry(node
, struct extent_state
, rb_node
);
439 printk(KERN_ERR
"btrfs found node %llu %llu on insert of "
441 found
->start
, found
->end
, start
, end
);
445 merge_state(tree
, state
);
449 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
452 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
453 tree
->ops
->split_extent_hook(tree
->mapping
->host
, orig
, split
);
457 * split a given extent state struct in two, inserting the preallocated
458 * struct 'prealloc' as the newly created second half. 'split' indicates an
459 * offset inside 'orig' where it should be split.
462 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
463 * are two extent state structs in the tree:
464 * prealloc: [orig->start, split - 1]
465 * orig: [ split, orig->end ]
467 * The tree locks are not taken by this function. They need to be held
470 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
471 struct extent_state
*prealloc
, u64 split
)
473 struct rb_node
*node
;
475 split_cb(tree
, orig
, split
);
477 prealloc
->start
= orig
->start
;
478 prealloc
->end
= split
- 1;
479 prealloc
->state
= orig
->state
;
482 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
,
485 free_extent_state(prealloc
);
488 prealloc
->tree
= tree
;
492 static struct extent_state
*next_state(struct extent_state
*state
)
494 struct rb_node
*next
= rb_next(&state
->rb_node
);
496 return rb_entry(next
, struct extent_state
, rb_node
);
502 * utility function to clear some bits in an extent state struct.
503 * it will optionally wake up any one waiting on this state (wake == 1).
505 * If no bits are set on the state struct after clearing things, the
506 * struct is freed and removed from the tree
508 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
509 struct extent_state
*state
,
510 unsigned long *bits
, int wake
)
512 struct extent_state
*next
;
513 unsigned long bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
515 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
516 u64 range
= state
->end
- state
->start
+ 1;
517 WARN_ON(range
> tree
->dirty_bytes
);
518 tree
->dirty_bytes
-= range
;
520 clear_state_cb(tree
, state
, bits
);
521 state
->state
&= ~bits_to_clear
;
524 if (state
->state
== 0) {
525 next
= next_state(state
);
527 rb_erase(&state
->rb_node
, &tree
->state
);
529 free_extent_state(state
);
534 merge_state(tree
, state
);
535 next
= next_state(state
);
540 static struct extent_state
*
541 alloc_extent_state_atomic(struct extent_state
*prealloc
)
544 prealloc
= alloc_extent_state(GFP_ATOMIC
);
549 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
551 btrfs_panic(tree_fs_info(tree
), err
, "Locking error: "
552 "Extent tree was modified by another "
553 "thread while locked.");
557 * clear some bits on a range in the tree. This may require splitting
558 * or inserting elements in the tree, so the gfp mask is used to
559 * indicate which allocations or sleeping are allowed.
561 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
562 * the given range from the tree regardless of state (ie for truncate).
564 * the range [start, end] is inclusive.
566 * This takes the tree lock, and returns 0 on success and < 0 on error.
568 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
569 unsigned long bits
, int wake
, int delete,
570 struct extent_state
**cached_state
,
573 struct extent_state
*state
;
574 struct extent_state
*cached
;
575 struct extent_state
*prealloc
= NULL
;
576 struct rb_node
*node
;
581 btrfs_debug_check_extent_io_range(tree
, start
, end
);
583 if (bits
& EXTENT_DELALLOC
)
584 bits
|= EXTENT_NORESERVE
;
587 bits
|= ~EXTENT_CTLBITS
;
588 bits
|= EXTENT_FIRST_DELALLOC
;
590 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
593 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
594 prealloc
= alloc_extent_state(mask
);
599 spin_lock(&tree
->lock
);
601 cached
= *cached_state
;
604 *cached_state
= NULL
;
608 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
609 cached
->end
> start
) {
611 atomic_dec(&cached
->refs
);
616 free_extent_state(cached
);
619 * this search will find the extents that end after
622 node
= tree_search(tree
, start
);
625 state
= rb_entry(node
, struct extent_state
, rb_node
);
627 if (state
->start
> end
)
629 WARN_ON(state
->end
< start
);
630 last_end
= state
->end
;
632 /* the state doesn't have the wanted bits, go ahead */
633 if (!(state
->state
& bits
)) {
634 state
= next_state(state
);
639 * | ---- desired range ---- |
641 * | ------------- state -------------- |
643 * We need to split the extent we found, and may flip
644 * bits on second half.
646 * If the extent we found extends past our range, we
647 * just split and search again. It'll get split again
648 * the next time though.
650 * If the extent we found is inside our range, we clear
651 * the desired bit on it.
654 if (state
->start
< start
) {
655 prealloc
= alloc_extent_state_atomic(prealloc
);
657 err
= split_state(tree
, state
, prealloc
, start
);
659 extent_io_tree_panic(tree
, err
);
664 if (state
->end
<= end
) {
665 state
= clear_state_bit(tree
, state
, &bits
, wake
);
671 * | ---- desired range ---- |
673 * We need to split the extent, and clear the bit
676 if (state
->start
<= end
&& state
->end
> end
) {
677 prealloc
= alloc_extent_state_atomic(prealloc
);
679 err
= split_state(tree
, state
, prealloc
, end
+ 1);
681 extent_io_tree_panic(tree
, err
);
686 clear_state_bit(tree
, prealloc
, &bits
, wake
);
692 state
= clear_state_bit(tree
, state
, &bits
, wake
);
694 if (last_end
== (u64
)-1)
696 start
= last_end
+ 1;
697 if (start
<= end
&& state
&& !need_resched())
702 spin_unlock(&tree
->lock
);
704 free_extent_state(prealloc
);
711 spin_unlock(&tree
->lock
);
712 if (mask
& __GFP_WAIT
)
717 static void wait_on_state(struct extent_io_tree
*tree
,
718 struct extent_state
*state
)
719 __releases(tree
->lock
)
720 __acquires(tree
->lock
)
723 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
724 spin_unlock(&tree
->lock
);
726 spin_lock(&tree
->lock
);
727 finish_wait(&state
->wq
, &wait
);
731 * waits for one or more bits to clear on a range in the state tree.
732 * The range [start, end] is inclusive.
733 * The tree lock is taken by this function
735 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
738 struct extent_state
*state
;
739 struct rb_node
*node
;
741 btrfs_debug_check_extent_io_range(tree
, start
, end
);
743 spin_lock(&tree
->lock
);
747 * this search will find all the extents that end after
750 node
= tree_search(tree
, start
);
754 state
= rb_entry(node
, struct extent_state
, rb_node
);
756 if (state
->start
> end
)
759 if (state
->state
& bits
) {
760 start
= state
->start
;
761 atomic_inc(&state
->refs
);
762 wait_on_state(tree
, state
);
763 free_extent_state(state
);
766 start
= state
->end
+ 1;
771 cond_resched_lock(&tree
->lock
);
774 spin_unlock(&tree
->lock
);
777 static void set_state_bits(struct extent_io_tree
*tree
,
778 struct extent_state
*state
,
781 unsigned long bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
783 set_state_cb(tree
, state
, bits
);
784 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
785 u64 range
= state
->end
- state
->start
+ 1;
786 tree
->dirty_bytes
+= range
;
788 state
->state
|= bits_to_set
;
791 static void cache_state(struct extent_state
*state
,
792 struct extent_state
**cached_ptr
)
794 if (cached_ptr
&& !(*cached_ptr
)) {
795 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
)) {
797 atomic_inc(&state
->refs
);
803 * set some bits on a range in the tree. This may require allocations or
804 * sleeping, so the gfp mask is used to indicate what is allowed.
806 * If any of the exclusive bits are set, this will fail with -EEXIST if some
807 * part of the range already has the desired bits set. The start of the
808 * existing range is returned in failed_start in this case.
810 * [start, end] is inclusive This takes the tree lock.
813 static int __must_check
814 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
815 unsigned long bits
, unsigned long exclusive_bits
,
816 u64
*failed_start
, struct extent_state
**cached_state
,
819 struct extent_state
*state
;
820 struct extent_state
*prealloc
= NULL
;
821 struct rb_node
*node
;
823 struct rb_node
*parent
;
828 btrfs_debug_check_extent_io_range(tree
, start
, end
);
830 bits
|= EXTENT_FIRST_DELALLOC
;
832 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
833 prealloc
= alloc_extent_state(mask
);
837 spin_lock(&tree
->lock
);
838 if (cached_state
&& *cached_state
) {
839 state
= *cached_state
;
840 if (state
->start
<= start
&& state
->end
> start
&&
842 node
= &state
->rb_node
;
847 * this search will find all the extents that end after
850 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
852 prealloc
= alloc_extent_state_atomic(prealloc
);
854 err
= insert_state(tree
, prealloc
, start
, end
,
857 extent_io_tree_panic(tree
, err
);
859 cache_state(prealloc
, cached_state
);
863 state
= rb_entry(node
, struct extent_state
, rb_node
);
865 last_start
= state
->start
;
866 last_end
= state
->end
;
869 * | ---- desired range ---- |
872 * Just lock what we found and keep going
874 if (state
->start
== start
&& state
->end
<= end
) {
875 if (state
->state
& exclusive_bits
) {
876 *failed_start
= state
->start
;
881 set_state_bits(tree
, state
, &bits
);
882 cache_state(state
, cached_state
);
883 merge_state(tree
, state
);
884 if (last_end
== (u64
)-1)
886 start
= last_end
+ 1;
887 state
= next_state(state
);
888 if (start
< end
&& state
&& state
->start
== start
&&
895 * | ---- desired range ---- |
898 * | ------------- state -------------- |
900 * We need to split the extent we found, and may flip bits on
903 * If the extent we found extends past our
904 * range, we just split and search again. It'll get split
905 * again the next time though.
907 * If the extent we found is inside our range, we set the
910 if (state
->start
< start
) {
911 if (state
->state
& exclusive_bits
) {
912 *failed_start
= start
;
917 prealloc
= alloc_extent_state_atomic(prealloc
);
919 err
= split_state(tree
, state
, prealloc
, start
);
921 extent_io_tree_panic(tree
, err
);
926 if (state
->end
<= end
) {
927 set_state_bits(tree
, state
, &bits
);
928 cache_state(state
, cached_state
);
929 merge_state(tree
, state
);
930 if (last_end
== (u64
)-1)
932 start
= last_end
+ 1;
933 state
= next_state(state
);
934 if (start
< end
&& state
&& state
->start
== start
&&
941 * | ---- desired range ---- |
942 * | state | or | state |
944 * There's a hole, we need to insert something in it and
945 * ignore the extent we found.
947 if (state
->start
> start
) {
949 if (end
< last_start
)
952 this_end
= last_start
- 1;
954 prealloc
= alloc_extent_state_atomic(prealloc
);
958 * Avoid to free 'prealloc' if it can be merged with
961 err
= insert_state(tree
, prealloc
, start
, this_end
,
964 extent_io_tree_panic(tree
, err
);
966 cache_state(prealloc
, cached_state
);
968 start
= this_end
+ 1;
972 * | ---- desired range ---- |
974 * We need to split the extent, and set the bit
977 if (state
->start
<= end
&& state
->end
> end
) {
978 if (state
->state
& exclusive_bits
) {
979 *failed_start
= start
;
984 prealloc
= alloc_extent_state_atomic(prealloc
);
986 err
= split_state(tree
, state
, prealloc
, end
+ 1);
988 extent_io_tree_panic(tree
, err
);
990 set_state_bits(tree
, prealloc
, &bits
);
991 cache_state(prealloc
, cached_state
);
992 merge_state(tree
, prealloc
);
1000 spin_unlock(&tree
->lock
);
1002 free_extent_state(prealloc
);
1009 spin_unlock(&tree
->lock
);
1010 if (mask
& __GFP_WAIT
)
1015 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1016 unsigned long bits
, u64
* failed_start
,
1017 struct extent_state
**cached_state
, gfp_t mask
)
1019 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
1020 cached_state
, mask
);
1025 * convert_extent_bit - convert all bits in a given range from one bit to
1027 * @tree: the io tree to search
1028 * @start: the start offset in bytes
1029 * @end: the end offset in bytes (inclusive)
1030 * @bits: the bits to set in this range
1031 * @clear_bits: the bits to clear in this range
1032 * @cached_state: state that we're going to cache
1033 * @mask: the allocation mask
1035 * This will go through and set bits for the given range. If any states exist
1036 * already in this range they are set with the given bit and cleared of the
1037 * clear_bits. This is only meant to be used by things that are mergeable, ie
1038 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1039 * boundary bits like LOCK.
1041 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1042 unsigned long bits
, unsigned long clear_bits
,
1043 struct extent_state
**cached_state
, gfp_t mask
)
1045 struct extent_state
*state
;
1046 struct extent_state
*prealloc
= NULL
;
1047 struct rb_node
*node
;
1049 struct rb_node
*parent
;
1054 btrfs_debug_check_extent_io_range(tree
, start
, end
);
1057 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
1058 prealloc
= alloc_extent_state(mask
);
1063 spin_lock(&tree
->lock
);
1064 if (cached_state
&& *cached_state
) {
1065 state
= *cached_state
;
1066 if (state
->start
<= start
&& state
->end
> start
&&
1068 node
= &state
->rb_node
;
1074 * this search will find all the extents that end after
1077 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
1079 prealloc
= alloc_extent_state_atomic(prealloc
);
1084 err
= insert_state(tree
, prealloc
, start
, end
,
1085 &p
, &parent
, &bits
);
1087 extent_io_tree_panic(tree
, err
);
1088 cache_state(prealloc
, cached_state
);
1092 state
= rb_entry(node
, struct extent_state
, rb_node
);
1094 last_start
= state
->start
;
1095 last_end
= state
->end
;
1098 * | ---- desired range ---- |
1101 * Just lock what we found and keep going
1103 if (state
->start
== start
&& state
->end
<= end
) {
1104 set_state_bits(tree
, state
, &bits
);
1105 cache_state(state
, cached_state
);
1106 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1107 if (last_end
== (u64
)-1)
1109 start
= last_end
+ 1;
1110 if (start
< end
&& state
&& state
->start
== start
&&
1117 * | ---- desired range ---- |
1120 * | ------------- state -------------- |
1122 * We need to split the extent we found, and may flip bits on
1125 * If the extent we found extends past our
1126 * range, we just split and search again. It'll get split
1127 * again the next time though.
1129 * If the extent we found is inside our range, we set the
1130 * desired bit on it.
1132 if (state
->start
< start
) {
1133 prealloc
= alloc_extent_state_atomic(prealloc
);
1138 err
= split_state(tree
, state
, prealloc
, start
);
1140 extent_io_tree_panic(tree
, err
);
1144 if (state
->end
<= end
) {
1145 set_state_bits(tree
, state
, &bits
);
1146 cache_state(state
, cached_state
);
1147 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1148 if (last_end
== (u64
)-1)
1150 start
= last_end
+ 1;
1151 if (start
< end
&& state
&& state
->start
== start
&&
1158 * | ---- desired range ---- |
1159 * | state | or | state |
1161 * There's a hole, we need to insert something in it and
1162 * ignore the extent we found.
1164 if (state
->start
> start
) {
1166 if (end
< last_start
)
1169 this_end
= last_start
- 1;
1171 prealloc
= alloc_extent_state_atomic(prealloc
);
1178 * Avoid to free 'prealloc' if it can be merged with
1181 err
= insert_state(tree
, prealloc
, start
, this_end
,
1184 extent_io_tree_panic(tree
, err
);
1185 cache_state(prealloc
, cached_state
);
1187 start
= this_end
+ 1;
1191 * | ---- desired range ---- |
1193 * We need to split the extent, and set the bit
1196 if (state
->start
<= end
&& state
->end
> end
) {
1197 prealloc
= alloc_extent_state_atomic(prealloc
);
1203 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1205 extent_io_tree_panic(tree
, err
);
1207 set_state_bits(tree
, prealloc
, &bits
);
1208 cache_state(prealloc
, cached_state
);
1209 clear_state_bit(tree
, prealloc
, &clear_bits
, 0);
1217 spin_unlock(&tree
->lock
);
1219 free_extent_state(prealloc
);
1226 spin_unlock(&tree
->lock
);
1227 if (mask
& __GFP_WAIT
)
1232 /* wrappers around set/clear extent bit */
1233 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1236 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, NULL
,
1240 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1241 unsigned long bits
, gfp_t mask
)
1243 return set_extent_bit(tree
, start
, end
, bits
, NULL
,
1247 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1248 unsigned long bits
, gfp_t mask
)
1250 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, mask
);
1253 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1254 struct extent_state
**cached_state
, gfp_t mask
)
1256 return set_extent_bit(tree
, start
, end
,
1257 EXTENT_DELALLOC
| EXTENT_UPTODATE
,
1258 NULL
, cached_state
, mask
);
1261 int set_extent_defrag(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1262 struct extent_state
**cached_state
, gfp_t mask
)
1264 return set_extent_bit(tree
, start
, end
,
1265 EXTENT_DELALLOC
| EXTENT_UPTODATE
| EXTENT_DEFRAG
,
1266 NULL
, cached_state
, mask
);
1269 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1272 return clear_extent_bit(tree
, start
, end
,
1273 EXTENT_DIRTY
| EXTENT_DELALLOC
|
1274 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
, mask
);
1277 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1280 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, NULL
,
1284 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1285 struct extent_state
**cached_state
, gfp_t mask
)
1287 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, NULL
,
1288 cached_state
, mask
);
1291 int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1292 struct extent_state
**cached_state
, gfp_t mask
)
1294 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0,
1295 cached_state
, mask
);
1299 * either insert or lock state struct between start and end use mask to tell
1300 * us if waiting is desired.
1302 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1303 unsigned long bits
, struct extent_state
**cached_state
)
1308 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
1309 EXTENT_LOCKED
, &failed_start
,
1310 cached_state
, GFP_NOFS
);
1311 if (err
== -EEXIST
) {
1312 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1313 start
= failed_start
;
1316 WARN_ON(start
> end
);
1321 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1323 return lock_extent_bits(tree
, start
, end
, 0, NULL
);
1326 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1331 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1332 &failed_start
, NULL
, GFP_NOFS
);
1333 if (err
== -EEXIST
) {
1334 if (failed_start
> start
)
1335 clear_extent_bit(tree
, start
, failed_start
- 1,
1336 EXTENT_LOCKED
, 1, 0, NULL
, GFP_NOFS
);
1342 int unlock_extent_cached(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1343 struct extent_state
**cached
, gfp_t mask
)
1345 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, cached
,
1349 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1351 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, NULL
,
1355 int extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1357 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1358 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1361 while (index
<= end_index
) {
1362 page
= find_get_page(inode
->i_mapping
, index
);
1363 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1364 clear_page_dirty_for_io(page
);
1365 page_cache_release(page
);
1371 int extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1373 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1374 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1377 while (index
<= end_index
) {
1378 page
= find_get_page(inode
->i_mapping
, index
);
1379 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1380 account_page_redirty(page
);
1381 __set_page_dirty_nobuffers(page
);
1382 page_cache_release(page
);
1389 * helper function to set both pages and extents in the tree writeback
1391 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1393 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1394 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1397 while (index
<= end_index
) {
1398 page
= find_get_page(tree
->mapping
, index
);
1399 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1400 set_page_writeback(page
);
1401 page_cache_release(page
);
1407 /* find the first state struct with 'bits' set after 'start', and
1408 * return it. tree->lock must be held. NULL will returned if
1409 * nothing was found after 'start'
1411 static struct extent_state
*
1412 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1413 u64 start
, unsigned long bits
)
1415 struct rb_node
*node
;
1416 struct extent_state
*state
;
1419 * this search will find all the extents that end after
1422 node
= tree_search(tree
, start
);
1427 state
= rb_entry(node
, struct extent_state
, rb_node
);
1428 if (state
->end
>= start
&& (state
->state
& bits
))
1431 node
= rb_next(node
);
1440 * find the first offset in the io tree with 'bits' set. zero is
1441 * returned if we find something, and *start_ret and *end_ret are
1442 * set to reflect the state struct that was found.
1444 * If nothing was found, 1 is returned. If found something, return 0.
1446 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1447 u64
*start_ret
, u64
*end_ret
, unsigned long bits
,
1448 struct extent_state
**cached_state
)
1450 struct extent_state
*state
;
1454 spin_lock(&tree
->lock
);
1455 if (cached_state
&& *cached_state
) {
1456 state
= *cached_state
;
1457 if (state
->end
== start
- 1 && state
->tree
) {
1458 n
= rb_next(&state
->rb_node
);
1460 state
= rb_entry(n
, struct extent_state
,
1462 if (state
->state
& bits
)
1466 free_extent_state(*cached_state
);
1467 *cached_state
= NULL
;
1470 free_extent_state(*cached_state
);
1471 *cached_state
= NULL
;
1474 state
= find_first_extent_bit_state(tree
, start
, bits
);
1477 cache_state(state
, cached_state
);
1478 *start_ret
= state
->start
;
1479 *end_ret
= state
->end
;
1483 spin_unlock(&tree
->lock
);
1488 * find a contiguous range of bytes in the file marked as delalloc, not
1489 * more than 'max_bytes'. start and end are used to return the range,
1491 * 1 is returned if we find something, 0 if nothing was in the tree
1493 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1494 u64
*start
, u64
*end
, u64 max_bytes
,
1495 struct extent_state
**cached_state
)
1497 struct rb_node
*node
;
1498 struct extent_state
*state
;
1499 u64 cur_start
= *start
;
1501 u64 total_bytes
= 0;
1503 spin_lock(&tree
->lock
);
1506 * this search will find all the extents that end after
1509 node
= tree_search(tree
, cur_start
);
1517 state
= rb_entry(node
, struct extent_state
, rb_node
);
1518 if (found
&& (state
->start
!= cur_start
||
1519 (state
->state
& EXTENT_BOUNDARY
))) {
1522 if (!(state
->state
& EXTENT_DELALLOC
)) {
1528 *start
= state
->start
;
1529 *cached_state
= state
;
1530 atomic_inc(&state
->refs
);
1534 cur_start
= state
->end
+ 1;
1535 node
= rb_next(node
);
1536 total_bytes
+= state
->end
- state
->start
+ 1;
1537 if (total_bytes
>= max_bytes
)
1543 spin_unlock(&tree
->lock
);
1547 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1548 struct page
*locked_page
,
1552 struct page
*pages
[16];
1553 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1554 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1555 unsigned long nr_pages
= end_index
- index
+ 1;
1558 if (index
== locked_page
->index
&& end_index
== index
)
1561 while (nr_pages
> 0) {
1562 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1563 min_t(unsigned long, nr_pages
,
1564 ARRAY_SIZE(pages
)), pages
);
1565 for (i
= 0; i
< ret
; i
++) {
1566 if (pages
[i
] != locked_page
)
1567 unlock_page(pages
[i
]);
1568 page_cache_release(pages
[i
]);
1576 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1577 struct page
*locked_page
,
1581 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1582 unsigned long start_index
= index
;
1583 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1584 unsigned long pages_locked
= 0;
1585 struct page
*pages
[16];
1586 unsigned long nrpages
;
1590 /* the caller is responsible for locking the start index */
1591 if (index
== locked_page
->index
&& index
== end_index
)
1594 /* skip the page at the start index */
1595 nrpages
= end_index
- index
+ 1;
1596 while (nrpages
> 0) {
1597 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1598 min_t(unsigned long,
1599 nrpages
, ARRAY_SIZE(pages
)), pages
);
1604 /* now we have an array of pages, lock them all */
1605 for (i
= 0; i
< ret
; i
++) {
1607 * the caller is taking responsibility for
1610 if (pages
[i
] != locked_page
) {
1611 lock_page(pages
[i
]);
1612 if (!PageDirty(pages
[i
]) ||
1613 pages
[i
]->mapping
!= inode
->i_mapping
) {
1615 unlock_page(pages
[i
]);
1616 page_cache_release(pages
[i
]);
1620 page_cache_release(pages
[i
]);
1629 if (ret
&& pages_locked
) {
1630 __unlock_for_delalloc(inode
, locked_page
,
1632 ((u64
)(start_index
+ pages_locked
- 1)) <<
1639 * find a contiguous range of bytes in the file marked as delalloc, not
1640 * more than 'max_bytes'. start and end are used to return the range,
1642 * 1 is returned if we find something, 0 if nothing was in the tree
1644 STATIC u64
find_lock_delalloc_range(struct inode
*inode
,
1645 struct extent_io_tree
*tree
,
1646 struct page
*locked_page
, u64
*start
,
1647 u64
*end
, u64 max_bytes
)
1652 struct extent_state
*cached_state
= NULL
;
1657 /* step one, find a bunch of delalloc bytes starting at start */
1658 delalloc_start
= *start
;
1660 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1661 max_bytes
, &cached_state
);
1662 if (!found
|| delalloc_end
<= *start
) {
1663 *start
= delalloc_start
;
1664 *end
= delalloc_end
;
1665 free_extent_state(cached_state
);
1670 * start comes from the offset of locked_page. We have to lock
1671 * pages in order, so we can't process delalloc bytes before
1674 if (delalloc_start
< *start
)
1675 delalloc_start
= *start
;
1678 * make sure to limit the number of pages we try to lock down
1680 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
)
1681 delalloc_end
= delalloc_start
+ max_bytes
- 1;
1683 /* step two, lock all the pages after the page that has start */
1684 ret
= lock_delalloc_pages(inode
, locked_page
,
1685 delalloc_start
, delalloc_end
);
1686 if (ret
== -EAGAIN
) {
1687 /* some of the pages are gone, lets avoid looping by
1688 * shortening the size of the delalloc range we're searching
1690 free_extent_state(cached_state
);
1692 max_bytes
= PAGE_CACHE_SIZE
;
1700 BUG_ON(ret
); /* Only valid values are 0 and -EAGAIN */
1702 /* step three, lock the state bits for the whole range */
1703 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, 0, &cached_state
);
1705 /* then test to make sure it is all still delalloc */
1706 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1707 EXTENT_DELALLOC
, 1, cached_state
);
1709 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1710 &cached_state
, GFP_NOFS
);
1711 __unlock_for_delalloc(inode
, locked_page
,
1712 delalloc_start
, delalloc_end
);
1716 free_extent_state(cached_state
);
1717 *start
= delalloc_start
;
1718 *end
= delalloc_end
;
1723 int extent_clear_unlock_delalloc(struct inode
*inode
, u64 start
, u64 end
,
1724 struct page
*locked_page
,
1725 unsigned long clear_bits
,
1726 unsigned long page_ops
)
1728 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
1730 struct page
*pages
[16];
1731 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1732 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1733 unsigned long nr_pages
= end_index
- index
+ 1;
1736 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, NULL
, GFP_NOFS
);
1740 while (nr_pages
> 0) {
1741 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1742 min_t(unsigned long,
1743 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1744 for (i
= 0; i
< ret
; i
++) {
1746 if (page_ops
& PAGE_SET_PRIVATE2
)
1747 SetPagePrivate2(pages
[i
]);
1749 if (pages
[i
] == locked_page
) {
1750 page_cache_release(pages
[i
]);
1753 if (page_ops
& PAGE_CLEAR_DIRTY
)
1754 clear_page_dirty_for_io(pages
[i
]);
1755 if (page_ops
& PAGE_SET_WRITEBACK
)
1756 set_page_writeback(pages
[i
]);
1757 if (page_ops
& PAGE_END_WRITEBACK
)
1758 end_page_writeback(pages
[i
]);
1759 if (page_ops
& PAGE_UNLOCK
)
1760 unlock_page(pages
[i
]);
1761 page_cache_release(pages
[i
]);
1771 * count the number of bytes in the tree that have a given bit(s)
1772 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1773 * cached. The total number found is returned.
1775 u64
count_range_bits(struct extent_io_tree
*tree
,
1776 u64
*start
, u64 search_end
, u64 max_bytes
,
1777 unsigned long bits
, int contig
)
1779 struct rb_node
*node
;
1780 struct extent_state
*state
;
1781 u64 cur_start
= *start
;
1782 u64 total_bytes
= 0;
1786 if (WARN_ON(search_end
<= cur_start
))
1789 spin_lock(&tree
->lock
);
1790 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1791 total_bytes
= tree
->dirty_bytes
;
1795 * this search will find all the extents that end after
1798 node
= tree_search(tree
, cur_start
);
1803 state
= rb_entry(node
, struct extent_state
, rb_node
);
1804 if (state
->start
> search_end
)
1806 if (contig
&& found
&& state
->start
> last
+ 1)
1808 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1809 total_bytes
+= min(search_end
, state
->end
) + 1 -
1810 max(cur_start
, state
->start
);
1811 if (total_bytes
>= max_bytes
)
1814 *start
= max(cur_start
, state
->start
);
1818 } else if (contig
&& found
) {
1821 node
= rb_next(node
);
1826 spin_unlock(&tree
->lock
);
1831 * set the private field for a given byte offset in the tree. If there isn't
1832 * an extent_state there already, this does nothing.
1834 static int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1836 struct rb_node
*node
;
1837 struct extent_state
*state
;
1840 spin_lock(&tree
->lock
);
1842 * this search will find all the extents that end after
1845 node
= tree_search(tree
, start
);
1850 state
= rb_entry(node
, struct extent_state
, rb_node
);
1851 if (state
->start
!= start
) {
1855 state
->private = private;
1857 spin_unlock(&tree
->lock
);
1861 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1863 struct rb_node
*node
;
1864 struct extent_state
*state
;
1867 spin_lock(&tree
->lock
);
1869 * this search will find all the extents that end after
1872 node
= tree_search(tree
, start
);
1877 state
= rb_entry(node
, struct extent_state
, rb_node
);
1878 if (state
->start
!= start
) {
1882 *private = state
->private;
1884 spin_unlock(&tree
->lock
);
1889 * searches a range in the state tree for a given mask.
1890 * If 'filled' == 1, this returns 1 only if every extent in the tree
1891 * has the bits set. Otherwise, 1 is returned if any bit in the
1892 * range is found set.
1894 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1895 unsigned long bits
, int filled
, struct extent_state
*cached
)
1897 struct extent_state
*state
= NULL
;
1898 struct rb_node
*node
;
1901 spin_lock(&tree
->lock
);
1902 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
1903 cached
->end
> start
)
1904 node
= &cached
->rb_node
;
1906 node
= tree_search(tree
, start
);
1907 while (node
&& start
<= end
) {
1908 state
= rb_entry(node
, struct extent_state
, rb_node
);
1910 if (filled
&& state
->start
> start
) {
1915 if (state
->start
> end
)
1918 if (state
->state
& bits
) {
1922 } else if (filled
) {
1927 if (state
->end
== (u64
)-1)
1930 start
= state
->end
+ 1;
1933 node
= rb_next(node
);
1940 spin_unlock(&tree
->lock
);
1945 * helper function to set a given page up to date if all the
1946 * extents in the tree for that page are up to date
1948 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
1950 u64 start
= page_offset(page
);
1951 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1952 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1953 SetPageUptodate(page
);
1957 * When IO fails, either with EIO or csum verification fails, we
1958 * try other mirrors that might have a good copy of the data. This
1959 * io_failure_record is used to record state as we go through all the
1960 * mirrors. If another mirror has good data, the page is set up to date
1961 * and things continue. If a good mirror can't be found, the original
1962 * bio end_io callback is called to indicate things have failed.
1964 struct io_failure_record
{
1969 unsigned long bio_flags
;
1975 static int free_io_failure(struct inode
*inode
, struct io_failure_record
*rec
,
1980 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
1982 set_state_private(failure_tree
, rec
->start
, 0);
1983 ret
= clear_extent_bits(failure_tree
, rec
->start
,
1984 rec
->start
+ rec
->len
- 1,
1985 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
1989 ret
= clear_extent_bits(&BTRFS_I(inode
)->io_tree
, rec
->start
,
1990 rec
->start
+ rec
->len
- 1,
1991 EXTENT_DAMAGED
, GFP_NOFS
);
2000 * this bypasses the standard btrfs submit functions deliberately, as
2001 * the standard behavior is to write all copies in a raid setup. here we only
2002 * want to write the one bad copy. so we do the mapping for ourselves and issue
2003 * submit_bio directly.
2004 * to avoid any synchronization issues, wait for the data after writing, which
2005 * actually prevents the read that triggered the error from finishing.
2006 * currently, there can be no more than two copies of every data bit. thus,
2007 * exactly one rewrite is required.
2009 int repair_io_failure(struct btrfs_fs_info
*fs_info
, u64 start
,
2010 u64 length
, u64 logical
, struct page
*page
,
2014 struct btrfs_device
*dev
;
2017 struct btrfs_bio
*bbio
= NULL
;
2018 struct btrfs_mapping_tree
*map_tree
= &fs_info
->mapping_tree
;
2021 ASSERT(!(fs_info
->sb
->s_flags
& MS_RDONLY
));
2022 BUG_ON(!mirror_num
);
2024 /* we can't repair anything in raid56 yet */
2025 if (btrfs_is_parity_mirror(map_tree
, logical
, length
, mirror_num
))
2028 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2032 map_length
= length
;
2034 ret
= btrfs_map_block(fs_info
, WRITE
, logical
,
2035 &map_length
, &bbio
, mirror_num
);
2040 BUG_ON(mirror_num
!= bbio
->mirror_num
);
2041 sector
= bbio
->stripes
[mirror_num
-1].physical
>> 9;
2042 bio
->bi_sector
= sector
;
2043 dev
= bbio
->stripes
[mirror_num
-1].dev
;
2045 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2049 bio
->bi_bdev
= dev
->bdev
;
2050 bio_add_page(bio
, page
, length
, start
- page_offset(page
));
2052 if (btrfsic_submit_bio_wait(WRITE_SYNC
, bio
)) {
2053 /* try to remap that extent elsewhere? */
2055 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2059 printk_ratelimited_in_rcu(KERN_INFO
"btrfs read error corrected: ino %lu off %llu "
2060 "(dev %s sector %llu)\n", page
->mapping
->host
->i_ino
,
2061 start
, rcu_str_deref(dev
->name
), sector
);
2067 int repair_eb_io_failure(struct btrfs_root
*root
, struct extent_buffer
*eb
,
2070 u64 start
= eb
->start
;
2071 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2074 if (root
->fs_info
->sb
->s_flags
& MS_RDONLY
)
2077 for (i
= 0; i
< num_pages
; i
++) {
2078 struct page
*p
= extent_buffer_page(eb
, i
);
2079 ret
= repair_io_failure(root
->fs_info
, start
, PAGE_CACHE_SIZE
,
2080 start
, p
, mirror_num
);
2083 start
+= PAGE_CACHE_SIZE
;
2090 * each time an IO finishes, we do a fast check in the IO failure tree
2091 * to see if we need to process or clean up an io_failure_record
2093 static int clean_io_failure(u64 start
, struct page
*page
)
2096 u64 private_failure
;
2097 struct io_failure_record
*failrec
;
2098 struct inode
*inode
= page
->mapping
->host
;
2099 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2100 struct extent_state
*state
;
2106 ret
= count_range_bits(&BTRFS_I(inode
)->io_failure_tree
, &private,
2107 (u64
)-1, 1, EXTENT_DIRTY
, 0);
2111 ret
= get_state_private(&BTRFS_I(inode
)->io_failure_tree
, start
,
2116 failrec
= (struct io_failure_record
*)(unsigned long) private_failure
;
2117 BUG_ON(!failrec
->this_mirror
);
2119 if (failrec
->in_validation
) {
2120 /* there was no real error, just free the record */
2121 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2126 if (fs_info
->sb
->s_flags
& MS_RDONLY
)
2129 spin_lock(&BTRFS_I(inode
)->io_tree
.lock
);
2130 state
= find_first_extent_bit_state(&BTRFS_I(inode
)->io_tree
,
2133 spin_unlock(&BTRFS_I(inode
)->io_tree
.lock
);
2135 if (state
&& state
->start
<= failrec
->start
&&
2136 state
->end
>= failrec
->start
+ failrec
->len
- 1) {
2137 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2139 if (num_copies
> 1) {
2140 ret
= repair_io_failure(fs_info
, start
, failrec
->len
,
2141 failrec
->logical
, page
,
2142 failrec
->failed_mirror
);
2150 ret
= free_io_failure(inode
, failrec
, did_repair
);
2156 * this is a generic handler for readpage errors (default
2157 * readpage_io_failed_hook). if other copies exist, read those and write back
2158 * good data to the failed position. does not investigate in remapping the
2159 * failed extent elsewhere, hoping the device will be smart enough to do this as
2163 static int bio_readpage_error(struct bio
*failed_bio
, u64 phy_offset
,
2164 struct page
*page
, u64 start
, u64 end
,
2167 struct io_failure_record
*failrec
= NULL
;
2169 struct extent_map
*em
;
2170 struct inode
*inode
= page
->mapping
->host
;
2171 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2172 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2173 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2175 struct btrfs_io_bio
*btrfs_failed_bio
;
2176 struct btrfs_io_bio
*btrfs_bio
;
2182 BUG_ON(failed_bio
->bi_rw
& REQ_WRITE
);
2184 ret
= get_state_private(failure_tree
, start
, &private);
2186 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2189 failrec
->start
= start
;
2190 failrec
->len
= end
- start
+ 1;
2191 failrec
->this_mirror
= 0;
2192 failrec
->bio_flags
= 0;
2193 failrec
->in_validation
= 0;
2195 read_lock(&em_tree
->lock
);
2196 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2198 read_unlock(&em_tree
->lock
);
2203 if (em
->start
> start
|| em
->start
+ em
->len
<= start
) {
2204 free_extent_map(em
);
2207 read_unlock(&em_tree
->lock
);
2213 logical
= start
- em
->start
;
2214 logical
= em
->block_start
+ logical
;
2215 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2216 logical
= em
->block_start
;
2217 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2218 extent_set_compress_type(&failrec
->bio_flags
,
2221 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2222 "len=%llu\n", logical
, start
, failrec
->len
);
2223 failrec
->logical
= logical
;
2224 free_extent_map(em
);
2226 /* set the bits in the private failure tree */
2227 ret
= set_extent_bits(failure_tree
, start
, end
,
2228 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
2230 ret
= set_state_private(failure_tree
, start
,
2231 (u64
)(unsigned long)failrec
);
2232 /* set the bits in the inode's tree */
2234 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
,
2241 failrec
= (struct io_failure_record
*)(unsigned long)private;
2242 pr_debug("bio_readpage_error: (found) logical=%llu, "
2243 "start=%llu, len=%llu, validation=%d\n",
2244 failrec
->logical
, failrec
->start
, failrec
->len
,
2245 failrec
->in_validation
);
2247 * when data can be on disk more than twice, add to failrec here
2248 * (e.g. with a list for failed_mirror) to make
2249 * clean_io_failure() clean all those errors at once.
2252 num_copies
= btrfs_num_copies(BTRFS_I(inode
)->root
->fs_info
,
2253 failrec
->logical
, failrec
->len
);
2254 if (num_copies
== 1) {
2256 * we only have a single copy of the data, so don't bother with
2257 * all the retry and error correction code that follows. no
2258 * matter what the error is, it is very likely to persist.
2260 pr_debug("bio_readpage_error: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
2261 num_copies
, failrec
->this_mirror
, failed_mirror
);
2262 free_io_failure(inode
, failrec
, 0);
2267 * there are two premises:
2268 * a) deliver good data to the caller
2269 * b) correct the bad sectors on disk
2271 if (failed_bio
->bi_vcnt
> 1) {
2273 * to fulfill b), we need to know the exact failing sectors, as
2274 * we don't want to rewrite any more than the failed ones. thus,
2275 * we need separate read requests for the failed bio
2277 * if the following BUG_ON triggers, our validation request got
2278 * merged. we need separate requests for our algorithm to work.
2280 BUG_ON(failrec
->in_validation
);
2281 failrec
->in_validation
= 1;
2282 failrec
->this_mirror
= failed_mirror
;
2283 read_mode
= READ_SYNC
| REQ_FAILFAST_DEV
;
2286 * we're ready to fulfill a) and b) alongside. get a good copy
2287 * of the failed sector and if we succeed, we have setup
2288 * everything for repair_io_failure to do the rest for us.
2290 if (failrec
->in_validation
) {
2291 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2292 failrec
->in_validation
= 0;
2293 failrec
->this_mirror
= 0;
2295 failrec
->failed_mirror
= failed_mirror
;
2296 failrec
->this_mirror
++;
2297 if (failrec
->this_mirror
== failed_mirror
)
2298 failrec
->this_mirror
++;
2299 read_mode
= READ_SYNC
;
2302 if (failrec
->this_mirror
> num_copies
) {
2303 pr_debug("bio_readpage_error: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
2304 num_copies
, failrec
->this_mirror
, failed_mirror
);
2305 free_io_failure(inode
, failrec
, 0);
2309 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2311 free_io_failure(inode
, failrec
, 0);
2314 bio
->bi_end_io
= failed_bio
->bi_end_io
;
2315 bio
->bi_sector
= failrec
->logical
>> 9;
2316 bio
->bi_bdev
= BTRFS_I(inode
)->root
->fs_info
->fs_devices
->latest_bdev
;
2319 btrfs_failed_bio
= btrfs_io_bio(failed_bio
);
2320 if (btrfs_failed_bio
->csum
) {
2321 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2322 u16 csum_size
= btrfs_super_csum_size(fs_info
->super_copy
);
2324 btrfs_bio
= btrfs_io_bio(bio
);
2325 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
2326 phy_offset
>>= inode
->i_sb
->s_blocksize_bits
;
2327 phy_offset
*= csum_size
;
2328 memcpy(btrfs_bio
->csum
, btrfs_failed_bio
->csum
+ phy_offset
,
2332 bio_add_page(bio
, page
, failrec
->len
, start
- page_offset(page
));
2334 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2335 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode
,
2336 failrec
->this_mirror
, num_copies
, failrec
->in_validation
);
2338 ret
= tree
->ops
->submit_bio_hook(inode
, read_mode
, bio
,
2339 failrec
->this_mirror
,
2340 failrec
->bio_flags
, 0);
2344 /* lots and lots of room for performance fixes in the end_bio funcs */
2346 int end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2348 int uptodate
= (err
== 0);
2349 struct extent_io_tree
*tree
;
2352 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2354 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
2355 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
2356 end
, NULL
, uptodate
);
2362 ClearPageUptodate(page
);
2369 * after a writepage IO is done, we need to:
2370 * clear the uptodate bits on error
2371 * clear the writeback bits in the extent tree for this IO
2372 * end_page_writeback if the page has no more pending IO
2374 * Scheduling is not allowed, so the extent state tree is expected
2375 * to have one and only one object corresponding to this IO.
2377 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
2379 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2384 struct page
*page
= bvec
->bv_page
;
2386 /* We always issue full-page reads, but if some block
2387 * in a page fails to read, blk_update_request() will
2388 * advance bv_offset and adjust bv_len to compensate.
2389 * Print a warning for nonzero offsets, and an error
2390 * if they don't add up to a full page. */
2391 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2392 printk("%s page write in btrfs with offset %u and length %u\n",
2393 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2394 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2395 bvec
->bv_offset
, bvec
->bv_len
);
2397 start
= page_offset(page
);
2398 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2400 if (--bvec
>= bio
->bi_io_vec
)
2401 prefetchw(&bvec
->bv_page
->flags
);
2403 if (end_extent_writepage(page
, err
, start
, end
))
2406 end_page_writeback(page
);
2407 } while (bvec
>= bio
->bi_io_vec
);
2413 endio_readpage_release_extent(struct extent_io_tree
*tree
, u64 start
, u64 len
,
2416 struct extent_state
*cached
= NULL
;
2417 u64 end
= start
+ len
- 1;
2419 if (uptodate
&& tree
->track_uptodate
)
2420 set_extent_uptodate(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2421 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2425 * after a readpage IO is done, we need to:
2426 * clear the uptodate bits on error
2427 * set the uptodate bits if things worked
2428 * set the page up to date if all extents in the tree are uptodate
2429 * clear the lock bit in the extent tree
2430 * unlock the page if there are no other extents locked for it
2432 * Scheduling is not allowed, so the extent state tree is expected
2433 * to have one and only one object corresponding to this IO.
2435 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
2437 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2438 struct bio_vec
*bvec_end
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2439 struct bio_vec
*bvec
= bio
->bi_io_vec
;
2440 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2441 struct extent_io_tree
*tree
;
2446 u64 extent_start
= 0;
2455 struct page
*page
= bvec
->bv_page
;
2456 struct inode
*inode
= page
->mapping
->host
;
2458 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2459 "mirror=%lu\n", (u64
)bio
->bi_sector
, err
,
2460 io_bio
->mirror_num
);
2461 tree
= &BTRFS_I(inode
)->io_tree
;
2463 /* We always issue full-page reads, but if some block
2464 * in a page fails to read, blk_update_request() will
2465 * advance bv_offset and adjust bv_len to compensate.
2466 * Print a warning for nonzero offsets, and an error
2467 * if they don't add up to a full page. */
2468 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2469 printk("%s page read in btrfs with offset %u and length %u\n",
2470 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2471 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2472 bvec
->bv_offset
, bvec
->bv_len
);
2474 start
= page_offset(page
);
2475 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2478 if (++bvec
<= bvec_end
)
2479 prefetchw(&bvec
->bv_page
->flags
);
2481 mirror
= io_bio
->mirror_num
;
2482 if (likely(uptodate
&& tree
->ops
&&
2483 tree
->ops
->readpage_end_io_hook
)) {
2484 ret
= tree
->ops
->readpage_end_io_hook(io_bio
, offset
,
2490 clean_io_failure(start
, page
);
2493 if (likely(uptodate
))
2496 if (tree
->ops
&& tree
->ops
->readpage_io_failed_hook
) {
2497 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2499 test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
2503 * The generic bio_readpage_error handles errors the
2504 * following way: If possible, new read requests are
2505 * created and submitted and will end up in
2506 * end_bio_extent_readpage as well (if we're lucky, not
2507 * in the !uptodate case). In that case it returns 0 and
2508 * we just go on with the next page in our bio. If it
2509 * can't handle the error it will return -EIO and we
2510 * remain responsible for that page.
2512 ret
= bio_readpage_error(bio
, offset
, page
, start
, end
,
2516 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2523 if (likely(uptodate
)) {
2524 loff_t i_size
= i_size_read(inode
);
2525 pgoff_t end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2528 /* Zero out the end if this page straddles i_size */
2529 offset
= i_size
& (PAGE_CACHE_SIZE
-1);
2530 if (page
->index
== end_index
&& offset
)
2531 zero_user_segment(page
, offset
, PAGE_CACHE_SIZE
);
2532 SetPageUptodate(page
);
2534 ClearPageUptodate(page
);
2540 if (unlikely(!uptodate
)) {
2542 endio_readpage_release_extent(tree
,
2548 endio_readpage_release_extent(tree
, start
,
2549 end
- start
+ 1, 0);
2550 } else if (!extent_len
) {
2551 extent_start
= start
;
2552 extent_len
= end
+ 1 - start
;
2553 } else if (extent_start
+ extent_len
== start
) {
2554 extent_len
+= end
+ 1 - start
;
2556 endio_readpage_release_extent(tree
, extent_start
,
2557 extent_len
, uptodate
);
2558 extent_start
= start
;
2559 extent_len
= end
+ 1 - start
;
2561 } while (bvec
<= bvec_end
);
2564 endio_readpage_release_extent(tree
, extent_start
, extent_len
,
2567 io_bio
->end_io(io_bio
, err
);
2572 * this allocates from the btrfs_bioset. We're returning a bio right now
2573 * but you can call btrfs_io_bio for the appropriate container_of magic
2576 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
2579 struct btrfs_io_bio
*btrfs_bio
;
2582 bio
= bio_alloc_bioset(gfp_flags
, nr_vecs
, btrfs_bioset
);
2584 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
2585 while (!bio
&& (nr_vecs
/= 2)) {
2586 bio
= bio_alloc_bioset(gfp_flags
,
2587 nr_vecs
, btrfs_bioset
);
2593 bio
->bi_bdev
= bdev
;
2594 bio
->bi_sector
= first_sector
;
2595 btrfs_bio
= btrfs_io_bio(bio
);
2596 btrfs_bio
->csum
= NULL
;
2597 btrfs_bio
->csum_allocated
= NULL
;
2598 btrfs_bio
->end_io
= NULL
;
2603 struct bio
*btrfs_bio_clone(struct bio
*bio
, gfp_t gfp_mask
)
2605 return bio_clone_bioset(bio
, gfp_mask
, btrfs_bioset
);
2609 /* this also allocates from the btrfs_bioset */
2610 struct bio
*btrfs_io_bio_alloc(gfp_t gfp_mask
, unsigned int nr_iovecs
)
2612 struct btrfs_io_bio
*btrfs_bio
;
2615 bio
= bio_alloc_bioset(gfp_mask
, nr_iovecs
, btrfs_bioset
);
2617 btrfs_bio
= btrfs_io_bio(bio
);
2618 btrfs_bio
->csum
= NULL
;
2619 btrfs_bio
->csum_allocated
= NULL
;
2620 btrfs_bio
->end_io
= NULL
;
2626 static int __must_check
submit_one_bio(int rw
, struct bio
*bio
,
2627 int mirror_num
, unsigned long bio_flags
)
2630 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2631 struct page
*page
= bvec
->bv_page
;
2632 struct extent_io_tree
*tree
= bio
->bi_private
;
2635 start
= page_offset(page
) + bvec
->bv_offset
;
2637 bio
->bi_private
= NULL
;
2641 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
2642 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
2643 mirror_num
, bio_flags
, start
);
2645 btrfsic_submit_bio(rw
, bio
);
2647 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
2653 static int merge_bio(int rw
, struct extent_io_tree
*tree
, struct page
*page
,
2654 unsigned long offset
, size_t size
, struct bio
*bio
,
2655 unsigned long bio_flags
)
2658 if (tree
->ops
&& tree
->ops
->merge_bio_hook
)
2659 ret
= tree
->ops
->merge_bio_hook(rw
, page
, offset
, size
, bio
,
2666 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
2667 struct page
*page
, sector_t sector
,
2668 size_t size
, unsigned long offset
,
2669 struct block_device
*bdev
,
2670 struct bio
**bio_ret
,
2671 unsigned long max_pages
,
2672 bio_end_io_t end_io_func
,
2674 unsigned long prev_bio_flags
,
2675 unsigned long bio_flags
)
2681 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
2682 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2683 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
2685 if (bio_ret
&& *bio_ret
) {
2688 contig
= bio
->bi_sector
== sector
;
2690 contig
= bio_end_sector(bio
) == sector
;
2692 if (prev_bio_flags
!= bio_flags
|| !contig
||
2693 merge_bio(rw
, tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2694 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2695 ret
= submit_one_bio(rw
, bio
, mirror_num
,
2704 if (this_compressed
)
2707 nr
= bio_get_nr_vecs(bdev
);
2709 bio
= btrfs_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
2713 bio_add_page(bio
, page
, page_size
, offset
);
2714 bio
->bi_end_io
= end_io_func
;
2715 bio
->bi_private
= tree
;
2720 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
2725 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2728 if (!PagePrivate(page
)) {
2729 SetPagePrivate(page
);
2730 page_cache_get(page
);
2731 set_page_private(page
, (unsigned long)eb
);
2733 WARN_ON(page
->private != (unsigned long)eb
);
2737 void set_page_extent_mapped(struct page
*page
)
2739 if (!PagePrivate(page
)) {
2740 SetPagePrivate(page
);
2741 page_cache_get(page
);
2742 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2746 static struct extent_map
*
2747 __get_extent_map(struct inode
*inode
, struct page
*page
, size_t pg_offset
,
2748 u64 start
, u64 len
, get_extent_t
*get_extent
,
2749 struct extent_map
**em_cached
)
2751 struct extent_map
*em
;
2753 if (em_cached
&& *em_cached
) {
2755 if (em
->in_tree
&& start
>= em
->start
&&
2756 start
< extent_map_end(em
)) {
2757 atomic_inc(&em
->refs
);
2761 free_extent_map(em
);
2765 em
= get_extent(inode
, page
, pg_offset
, start
, len
, 0);
2766 if (em_cached
&& !IS_ERR_OR_NULL(em
)) {
2768 atomic_inc(&em
->refs
);
2774 * basic readpage implementation. Locked extent state structs are inserted
2775 * into the tree that are removed when the IO is done (by the end_io
2777 * XXX JDM: This needs looking at to ensure proper page locking
2779 static int __do_readpage(struct extent_io_tree
*tree
,
2781 get_extent_t
*get_extent
,
2782 struct extent_map
**em_cached
,
2783 struct bio
**bio
, int mirror_num
,
2784 unsigned long *bio_flags
, int rw
)
2786 struct inode
*inode
= page
->mapping
->host
;
2787 u64 start
= page_offset(page
);
2788 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2792 u64 last_byte
= i_size_read(inode
);
2796 struct extent_map
*em
;
2797 struct block_device
*bdev
;
2800 int parent_locked
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2801 size_t pg_offset
= 0;
2803 size_t disk_io_size
;
2804 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2805 unsigned long this_bio_flag
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2807 set_page_extent_mapped(page
);
2810 if (!PageUptodate(page
)) {
2811 if (cleancache_get_page(page
) == 0) {
2812 BUG_ON(blocksize
!= PAGE_SIZE
);
2813 unlock_extent(tree
, start
, end
);
2818 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
2820 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
2823 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
2824 userpage
= kmap_atomic(page
);
2825 memset(userpage
+ zero_offset
, 0, iosize
);
2826 flush_dcache_page(page
);
2827 kunmap_atomic(userpage
);
2830 while (cur
<= end
) {
2831 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2833 if (cur
>= last_byte
) {
2835 struct extent_state
*cached
= NULL
;
2837 iosize
= PAGE_CACHE_SIZE
- pg_offset
;
2838 userpage
= kmap_atomic(page
);
2839 memset(userpage
+ pg_offset
, 0, iosize
);
2840 flush_dcache_page(page
);
2841 kunmap_atomic(userpage
);
2842 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2845 unlock_extent_cached(tree
, cur
,
2850 em
= __get_extent_map(inode
, page
, pg_offset
, cur
,
2851 end
- cur
+ 1, get_extent
, em_cached
);
2852 if (IS_ERR_OR_NULL(em
)) {
2855 unlock_extent(tree
, cur
, end
);
2858 extent_offset
= cur
- em
->start
;
2859 BUG_ON(extent_map_end(em
) <= cur
);
2862 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2863 this_bio_flag
|= EXTENT_BIO_COMPRESSED
;
2864 extent_set_compress_type(&this_bio_flag
,
2868 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2869 cur_end
= min(extent_map_end(em
) - 1, end
);
2870 iosize
= ALIGN(iosize
, blocksize
);
2871 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2872 disk_io_size
= em
->block_len
;
2873 sector
= em
->block_start
>> 9;
2875 sector
= (em
->block_start
+ extent_offset
) >> 9;
2876 disk_io_size
= iosize
;
2879 block_start
= em
->block_start
;
2880 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2881 block_start
= EXTENT_MAP_HOLE
;
2882 free_extent_map(em
);
2885 /* we've found a hole, just zero and go on */
2886 if (block_start
== EXTENT_MAP_HOLE
) {
2888 struct extent_state
*cached
= NULL
;
2890 userpage
= kmap_atomic(page
);
2891 memset(userpage
+ pg_offset
, 0, iosize
);
2892 flush_dcache_page(page
);
2893 kunmap_atomic(userpage
);
2895 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2897 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2900 pg_offset
+= iosize
;
2903 /* the get_extent function already copied into the page */
2904 if (test_range_bit(tree
, cur
, cur_end
,
2905 EXTENT_UPTODATE
, 1, NULL
)) {
2906 check_page_uptodate(tree
, page
);
2908 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2910 pg_offset
+= iosize
;
2913 /* we have an inline extent but it didn't get marked up
2914 * to date. Error out
2916 if (block_start
== EXTENT_MAP_INLINE
) {
2919 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2921 pg_offset
+= iosize
;
2926 ret
= submit_extent_page(rw
, tree
, page
,
2927 sector
, disk_io_size
, pg_offset
,
2929 end_bio_extent_readpage
, mirror_num
,
2934 *bio_flags
= this_bio_flag
;
2938 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2941 pg_offset
+= iosize
;
2945 if (!PageError(page
))
2946 SetPageUptodate(page
);
2952 static inline void __do_contiguous_readpages(struct extent_io_tree
*tree
,
2953 struct page
*pages
[], int nr_pages
,
2955 get_extent_t
*get_extent
,
2956 struct extent_map
**em_cached
,
2957 struct bio
**bio
, int mirror_num
,
2958 unsigned long *bio_flags
, int rw
)
2960 struct inode
*inode
;
2961 struct btrfs_ordered_extent
*ordered
;
2964 inode
= pages
[0]->mapping
->host
;
2966 lock_extent(tree
, start
, end
);
2967 ordered
= btrfs_lookup_ordered_range(inode
, start
,
2971 unlock_extent(tree
, start
, end
);
2972 btrfs_start_ordered_extent(inode
, ordered
, 1);
2973 btrfs_put_ordered_extent(ordered
);
2976 for (index
= 0; index
< nr_pages
; index
++) {
2977 __do_readpage(tree
, pages
[index
], get_extent
, em_cached
, bio
,
2978 mirror_num
, bio_flags
, rw
);
2979 page_cache_release(pages
[index
]);
2983 static void __extent_readpages(struct extent_io_tree
*tree
,
2984 struct page
*pages
[],
2985 int nr_pages
, get_extent_t
*get_extent
,
2986 struct extent_map
**em_cached
,
2987 struct bio
**bio
, int mirror_num
,
2988 unsigned long *bio_flags
, int rw
)
2994 int first_index
= 0;
2996 for (index
= 0; index
< nr_pages
; index
++) {
2997 page_start
= page_offset(pages
[index
]);
3000 end
= start
+ PAGE_CACHE_SIZE
- 1;
3001 first_index
= index
;
3002 } else if (end
+ 1 == page_start
) {
3003 end
+= PAGE_CACHE_SIZE
;
3005 __do_contiguous_readpages(tree
, &pages
[first_index
],
3006 index
- first_index
, start
,
3007 end
, get_extent
, em_cached
,
3008 bio
, mirror_num
, bio_flags
,
3011 end
= start
+ PAGE_CACHE_SIZE
- 1;
3012 first_index
= index
;
3017 __do_contiguous_readpages(tree
, &pages
[first_index
],
3018 index
- first_index
, start
,
3019 end
, get_extent
, em_cached
, bio
,
3020 mirror_num
, bio_flags
, rw
);
3023 static int __extent_read_full_page(struct extent_io_tree
*tree
,
3025 get_extent_t
*get_extent
,
3026 struct bio
**bio
, int mirror_num
,
3027 unsigned long *bio_flags
, int rw
)
3029 struct inode
*inode
= page
->mapping
->host
;
3030 struct btrfs_ordered_extent
*ordered
;
3031 u64 start
= page_offset(page
);
3032 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3036 lock_extent(tree
, start
, end
);
3037 ordered
= btrfs_lookup_ordered_extent(inode
, start
);
3040 unlock_extent(tree
, start
, end
);
3041 btrfs_start_ordered_extent(inode
, ordered
, 1);
3042 btrfs_put_ordered_extent(ordered
);
3045 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, bio
, mirror_num
,
3050 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3051 get_extent_t
*get_extent
, int mirror_num
)
3053 struct bio
*bio
= NULL
;
3054 unsigned long bio_flags
= 0;
3057 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
3060 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3064 int extent_read_full_page_nolock(struct extent_io_tree
*tree
, struct page
*page
,
3065 get_extent_t
*get_extent
, int mirror_num
)
3067 struct bio
*bio
= NULL
;
3068 unsigned long bio_flags
= EXTENT_BIO_PARENT_LOCKED
;
3071 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, &bio
, mirror_num
,
3074 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3078 static noinline
void update_nr_written(struct page
*page
,
3079 struct writeback_control
*wbc
,
3080 unsigned long nr_written
)
3082 wbc
->nr_to_write
-= nr_written
;
3083 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
3084 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
3085 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
3089 * the writepage semantics are similar to regular writepage. extent
3090 * records are inserted to lock ranges in the tree, and as dirty areas
3091 * are found, they are marked writeback. Then the lock bits are removed
3092 * and the end_io handler clears the writeback ranges
3094 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
3097 struct inode
*inode
= page
->mapping
->host
;
3098 struct extent_page_data
*epd
= data
;
3099 struct extent_io_tree
*tree
= epd
->tree
;
3100 u64 start
= page_offset(page
);
3102 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
3106 u64 last_byte
= i_size_read(inode
);
3110 struct extent_state
*cached_state
= NULL
;
3111 struct extent_map
*em
;
3112 struct block_device
*bdev
;
3115 size_t pg_offset
= 0;
3117 loff_t i_size
= i_size_read(inode
);
3118 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
3124 unsigned long nr_written
= 0;
3125 bool fill_delalloc
= true;
3127 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3128 write_flags
= WRITE_SYNC
;
3130 write_flags
= WRITE
;
3132 trace___extent_writepage(page
, inode
, wbc
);
3134 WARN_ON(!PageLocked(page
));
3136 ClearPageError(page
);
3138 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
3139 if (page
->index
> end_index
||
3140 (page
->index
== end_index
&& !pg_offset
)) {
3141 page
->mapping
->a_ops
->invalidatepage(page
, 0, PAGE_CACHE_SIZE
);
3146 if (page
->index
== end_index
) {
3149 userpage
= kmap_atomic(page
);
3150 memset(userpage
+ pg_offset
, 0,
3151 PAGE_CACHE_SIZE
- pg_offset
);
3152 kunmap_atomic(userpage
);
3153 flush_dcache_page(page
);
3157 set_page_extent_mapped(page
);
3159 if (!tree
->ops
|| !tree
->ops
->fill_delalloc
)
3160 fill_delalloc
= false;
3162 delalloc_start
= start
;
3165 if (!epd
->extent_locked
&& fill_delalloc
) {
3166 u64 delalloc_to_write
= 0;
3168 * make sure the wbc mapping index is at least updated
3171 update_nr_written(page
, wbc
, 0);
3173 while (delalloc_end
< page_end
) {
3174 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
3179 if (nr_delalloc
== 0) {
3180 delalloc_start
= delalloc_end
+ 1;
3183 ret
= tree
->ops
->fill_delalloc(inode
, page
,
3188 /* File system has been set read-only */
3194 * delalloc_end is already one less than the total
3195 * length, so we don't subtract one from
3198 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3201 delalloc_start
= delalloc_end
+ 1;
3203 if (wbc
->nr_to_write
< delalloc_to_write
) {
3206 if (delalloc_to_write
< thresh
* 2)
3207 thresh
= delalloc_to_write
;
3208 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3212 /* did the fill delalloc function already unlock and start
3218 * we've unlocked the page, so we can't update
3219 * the mapping's writeback index, just update
3222 wbc
->nr_to_write
-= nr_written
;
3226 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3227 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3230 /* Fixup worker will requeue */
3232 wbc
->pages_skipped
++;
3234 redirty_page_for_writepage(wbc
, page
);
3235 update_nr_written(page
, wbc
, nr_written
);
3243 * we don't want to touch the inode after unlocking the page,
3244 * so we update the mapping writeback index now
3246 update_nr_written(page
, wbc
, nr_written
+ 1);
3249 if (last_byte
<= start
) {
3250 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3251 tree
->ops
->writepage_end_io_hook(page
, start
,
3256 blocksize
= inode
->i_sb
->s_blocksize
;
3258 while (cur
<= end
) {
3259 if (cur
>= last_byte
) {
3260 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3261 tree
->ops
->writepage_end_io_hook(page
, cur
,
3265 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
3267 if (IS_ERR_OR_NULL(em
)) {
3272 extent_offset
= cur
- em
->start
;
3273 BUG_ON(extent_map_end(em
) <= cur
);
3275 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
3276 iosize
= ALIGN(iosize
, blocksize
);
3277 sector
= (em
->block_start
+ extent_offset
) >> 9;
3279 block_start
= em
->block_start
;
3280 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3281 free_extent_map(em
);
3285 * compressed and inline extents are written through other
3288 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3289 block_start
== EXTENT_MAP_INLINE
) {
3291 * end_io notification does not happen here for
3292 * compressed extents
3294 if (!compressed
&& tree
->ops
&&
3295 tree
->ops
->writepage_end_io_hook
)
3296 tree
->ops
->writepage_end_io_hook(page
, cur
,
3299 else if (compressed
) {
3300 /* we don't want to end_page_writeback on
3301 * a compressed extent. this happens
3308 pg_offset
+= iosize
;
3311 /* leave this out until we have a page_mkwrite call */
3312 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
3313 EXTENT_DIRTY
, 0, NULL
)) {
3315 pg_offset
+= iosize
;
3319 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
3320 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
3328 unsigned long max_nr
= end_index
+ 1;
3330 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3331 if (!PageWriteback(page
)) {
3332 printk(KERN_ERR
"btrfs warning page %lu not "
3333 "writeback, cur %llu end %llu\n",
3334 page
->index
, cur
, end
);
3337 ret
= submit_extent_page(write_flags
, tree
, page
,
3338 sector
, iosize
, pg_offset
,
3339 bdev
, &epd
->bio
, max_nr
,
3340 end_bio_extent_writepage
,
3346 pg_offset
+= iosize
;
3351 /* make sure the mapping tag for page dirty gets cleared */
3352 set_page_writeback(page
);
3353 end_page_writeback(page
);
3359 /* drop our reference on any cached states */
3360 free_extent_state(cached_state
);
3364 static int eb_wait(void *word
)
3370 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3372 wait_on_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
, eb_wait
,
3373 TASK_UNINTERRUPTIBLE
);
3376 static int lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3377 struct btrfs_fs_info
*fs_info
,
3378 struct extent_page_data
*epd
)
3380 unsigned long i
, num_pages
;
3384 if (!btrfs_try_tree_write_lock(eb
)) {
3386 flush_write_bio(epd
);
3387 btrfs_tree_lock(eb
);
3390 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3391 btrfs_tree_unlock(eb
);
3395 flush_write_bio(epd
);
3399 wait_on_extent_buffer_writeback(eb
);
3400 btrfs_tree_lock(eb
);
3401 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3403 btrfs_tree_unlock(eb
);
3408 * We need to do this to prevent races in people who check if the eb is
3409 * under IO since we can end up having no IO bits set for a short period
3412 spin_lock(&eb
->refs_lock
);
3413 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3414 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3415 spin_unlock(&eb
->refs_lock
);
3416 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3417 __percpu_counter_add(&fs_info
->dirty_metadata_bytes
,
3419 fs_info
->dirty_metadata_batch
);
3422 spin_unlock(&eb
->refs_lock
);
3425 btrfs_tree_unlock(eb
);
3430 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3431 for (i
= 0; i
< num_pages
; i
++) {
3432 struct page
*p
= extent_buffer_page(eb
, i
);
3434 if (!trylock_page(p
)) {
3436 flush_write_bio(epd
);
3446 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3448 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3449 smp_mb__after_clear_bit();
3450 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3453 static void end_bio_extent_buffer_writepage(struct bio
*bio
, int err
)
3455 int uptodate
= err
== 0;
3456 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
3457 struct extent_buffer
*eb
;
3461 struct page
*page
= bvec
->bv_page
;
3464 eb
= (struct extent_buffer
*)page
->private;
3466 done
= atomic_dec_and_test(&eb
->io_pages
);
3468 if (!uptodate
|| test_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
)) {
3469 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3470 ClearPageUptodate(page
);
3474 end_page_writeback(page
);
3479 end_extent_buffer_writeback(eb
);
3480 } while (bvec
>= bio
->bi_io_vec
);
3486 static int write_one_eb(struct extent_buffer
*eb
,
3487 struct btrfs_fs_info
*fs_info
,
3488 struct writeback_control
*wbc
,
3489 struct extent_page_data
*epd
)
3491 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3492 u64 offset
= eb
->start
;
3493 unsigned long i
, num_pages
;
3494 unsigned long bio_flags
= 0;
3495 int rw
= (epd
->sync_io
? WRITE_SYNC
: WRITE
) | REQ_META
;
3498 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3499 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3500 atomic_set(&eb
->io_pages
, num_pages
);
3501 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3502 bio_flags
= EXTENT_BIO_TREE_LOG
;
3504 for (i
= 0; i
< num_pages
; i
++) {
3505 struct page
*p
= extent_buffer_page(eb
, i
);
3507 clear_page_dirty_for_io(p
);
3508 set_page_writeback(p
);
3509 ret
= submit_extent_page(rw
, eb
->tree
, p
, offset
>> 9,
3510 PAGE_CACHE_SIZE
, 0, bdev
, &epd
->bio
,
3511 -1, end_bio_extent_buffer_writepage
,
3512 0, epd
->bio_flags
, bio_flags
);
3513 epd
->bio_flags
= bio_flags
;
3515 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3517 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3518 end_extent_buffer_writeback(eb
);
3522 offset
+= PAGE_CACHE_SIZE
;
3523 update_nr_written(p
, wbc
, 1);
3527 if (unlikely(ret
)) {
3528 for (; i
< num_pages
; i
++) {
3529 struct page
*p
= extent_buffer_page(eb
, i
);
3537 int btree_write_cache_pages(struct address_space
*mapping
,
3538 struct writeback_control
*wbc
)
3540 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3541 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3542 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3543 struct extent_page_data epd
= {
3547 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3552 int nr_to_write_done
= 0;
3553 struct pagevec pvec
;
3556 pgoff_t end
; /* Inclusive */
3560 pagevec_init(&pvec
, 0);
3561 if (wbc
->range_cyclic
) {
3562 index
= mapping
->writeback_index
; /* Start from prev offset */
3565 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3566 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3569 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3570 tag
= PAGECACHE_TAG_TOWRITE
;
3572 tag
= PAGECACHE_TAG_DIRTY
;
3574 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3575 tag_pages_for_writeback(mapping
, index
, end
);
3576 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3577 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3578 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3582 for (i
= 0; i
< nr_pages
; i
++) {
3583 struct page
*page
= pvec
.pages
[i
];
3585 if (!PagePrivate(page
))
3588 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3593 spin_lock(&mapping
->private_lock
);
3594 if (!PagePrivate(page
)) {
3595 spin_unlock(&mapping
->private_lock
);
3599 eb
= (struct extent_buffer
*)page
->private;
3602 * Shouldn't happen and normally this would be a BUG_ON
3603 * but no sense in crashing the users box for something
3604 * we can survive anyway.
3607 spin_unlock(&mapping
->private_lock
);
3611 if (eb
== prev_eb
) {
3612 spin_unlock(&mapping
->private_lock
);
3616 ret
= atomic_inc_not_zero(&eb
->refs
);
3617 spin_unlock(&mapping
->private_lock
);
3622 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3624 free_extent_buffer(eb
);
3628 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3631 free_extent_buffer(eb
);
3634 free_extent_buffer(eb
);
3637 * the filesystem may choose to bump up nr_to_write.
3638 * We have to make sure to honor the new nr_to_write
3641 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3643 pagevec_release(&pvec
);
3646 if (!scanned
&& !done
) {
3648 * We hit the last page and there is more work to be done: wrap
3649 * back to the start of the file
3655 flush_write_bio(&epd
);
3660 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3661 * @mapping: address space structure to write
3662 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3663 * @writepage: function called for each page
3664 * @data: data passed to writepage function
3666 * If a page is already under I/O, write_cache_pages() skips it, even
3667 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3668 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3669 * and msync() need to guarantee that all the data which was dirty at the time
3670 * the call was made get new I/O started against them. If wbc->sync_mode is
3671 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3672 * existing IO to complete.
3674 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
3675 struct address_space
*mapping
,
3676 struct writeback_control
*wbc
,
3677 writepage_t writepage
, void *data
,
3678 void (*flush_fn
)(void *))
3680 struct inode
*inode
= mapping
->host
;
3683 int nr_to_write_done
= 0;
3684 struct pagevec pvec
;
3687 pgoff_t end
; /* Inclusive */
3692 * We have to hold onto the inode so that ordered extents can do their
3693 * work when the IO finishes. The alternative to this is failing to add
3694 * an ordered extent if the igrab() fails there and that is a huge pain
3695 * to deal with, so instead just hold onto the inode throughout the
3696 * writepages operation. If it fails here we are freeing up the inode
3697 * anyway and we'd rather not waste our time writing out stuff that is
3698 * going to be truncated anyway.
3703 pagevec_init(&pvec
, 0);
3704 if (wbc
->range_cyclic
) {
3705 index
= mapping
->writeback_index
; /* Start from prev offset */
3708 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3709 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3712 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3713 tag
= PAGECACHE_TAG_TOWRITE
;
3715 tag
= PAGECACHE_TAG_DIRTY
;
3717 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3718 tag_pages_for_writeback(mapping
, index
, end
);
3719 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3720 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3721 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3725 for (i
= 0; i
< nr_pages
; i
++) {
3726 struct page
*page
= pvec
.pages
[i
];
3729 * At this point we hold neither mapping->tree_lock nor
3730 * lock on the page itself: the page may be truncated or
3731 * invalidated (changing page->mapping to NULL), or even
3732 * swizzled back from swapper_space to tmpfs file
3735 if (!trylock_page(page
)) {
3740 if (unlikely(page
->mapping
!= mapping
)) {
3745 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3751 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
3752 if (PageWriteback(page
))
3754 wait_on_page_writeback(page
);
3757 if (PageWriteback(page
) ||
3758 !clear_page_dirty_for_io(page
)) {
3763 ret
= (*writepage
)(page
, wbc
, data
);
3765 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
3773 * the filesystem may choose to bump up nr_to_write.
3774 * We have to make sure to honor the new nr_to_write
3777 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3779 pagevec_release(&pvec
);
3782 if (!scanned
&& !done
) {
3784 * We hit the last page and there is more work to be done: wrap
3785 * back to the start of the file
3791 btrfs_add_delayed_iput(inode
);
3795 static void flush_epd_write_bio(struct extent_page_data
*epd
)
3804 ret
= submit_one_bio(rw
, epd
->bio
, 0, epd
->bio_flags
);
3805 BUG_ON(ret
< 0); /* -ENOMEM */
3810 static noinline
void flush_write_bio(void *data
)
3812 struct extent_page_data
*epd
= data
;
3813 flush_epd_write_bio(epd
);
3816 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3817 get_extent_t
*get_extent
,
3818 struct writeback_control
*wbc
)
3821 struct extent_page_data epd
= {
3824 .get_extent
= get_extent
,
3826 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3830 ret
= __extent_writepage(page
, wbc
, &epd
);
3832 flush_epd_write_bio(&epd
);
3836 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
3837 u64 start
, u64 end
, get_extent_t
*get_extent
,
3841 struct address_space
*mapping
= inode
->i_mapping
;
3843 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
3846 struct extent_page_data epd
= {
3849 .get_extent
= get_extent
,
3851 .sync_io
= mode
== WB_SYNC_ALL
,
3854 struct writeback_control wbc_writepages
= {
3856 .nr_to_write
= nr_pages
* 2,
3857 .range_start
= start
,
3858 .range_end
= end
+ 1,
3861 while (start
<= end
) {
3862 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
3863 if (clear_page_dirty_for_io(page
))
3864 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
3866 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3867 tree
->ops
->writepage_end_io_hook(page
, start
,
3868 start
+ PAGE_CACHE_SIZE
- 1,
3872 page_cache_release(page
);
3873 start
+= PAGE_CACHE_SIZE
;
3876 flush_epd_write_bio(&epd
);
3880 int extent_writepages(struct extent_io_tree
*tree
,
3881 struct address_space
*mapping
,
3882 get_extent_t
*get_extent
,
3883 struct writeback_control
*wbc
)
3886 struct extent_page_data epd
= {
3889 .get_extent
= get_extent
,
3891 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3895 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
3896 __extent_writepage
, &epd
,
3898 flush_epd_write_bio(&epd
);
3902 int extent_readpages(struct extent_io_tree
*tree
,
3903 struct address_space
*mapping
,
3904 struct list_head
*pages
, unsigned nr_pages
,
3905 get_extent_t get_extent
)
3907 struct bio
*bio
= NULL
;
3909 unsigned long bio_flags
= 0;
3910 struct page
*pagepool
[16];
3912 struct extent_map
*em_cached
= NULL
;
3915 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
3916 page
= list_entry(pages
->prev
, struct page
, lru
);
3918 prefetchw(&page
->flags
);
3919 list_del(&page
->lru
);
3920 if (add_to_page_cache_lru(page
, mapping
,
3921 page
->index
, GFP_NOFS
)) {
3922 page_cache_release(page
);
3926 pagepool
[nr
++] = page
;
3927 if (nr
< ARRAY_SIZE(pagepool
))
3929 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
3930 &bio
, 0, &bio_flags
, READ
);
3934 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
3935 &bio
, 0, &bio_flags
, READ
);
3938 free_extent_map(em_cached
);
3940 BUG_ON(!list_empty(pages
));
3942 return submit_one_bio(READ
, bio
, 0, bio_flags
);
3947 * basic invalidatepage code, this waits on any locked or writeback
3948 * ranges corresponding to the page, and then deletes any extent state
3949 * records from the tree
3951 int extent_invalidatepage(struct extent_io_tree
*tree
,
3952 struct page
*page
, unsigned long offset
)
3954 struct extent_state
*cached_state
= NULL
;
3955 u64 start
= page_offset(page
);
3956 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3957 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
3959 start
+= ALIGN(offset
, blocksize
);
3963 lock_extent_bits(tree
, start
, end
, 0, &cached_state
);
3964 wait_on_page_writeback(page
);
3965 clear_extent_bit(tree
, start
, end
,
3966 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
3967 EXTENT_DO_ACCOUNTING
,
3968 1, 1, &cached_state
, GFP_NOFS
);
3973 * a helper for releasepage, this tests for areas of the page that
3974 * are locked or under IO and drops the related state bits if it is safe
3977 static int try_release_extent_state(struct extent_map_tree
*map
,
3978 struct extent_io_tree
*tree
,
3979 struct page
*page
, gfp_t mask
)
3981 u64 start
= page_offset(page
);
3982 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3985 if (test_range_bit(tree
, start
, end
,
3986 EXTENT_IOBITS
, 0, NULL
))
3989 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
3992 * at this point we can safely clear everything except the
3993 * locked bit and the nodatasum bit
3995 ret
= clear_extent_bit(tree
, start
, end
,
3996 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
3999 /* if clear_extent_bit failed for enomem reasons,
4000 * we can't allow the release to continue.
4011 * a helper for releasepage. As long as there are no locked extents
4012 * in the range corresponding to the page, both state records and extent
4013 * map records are removed
4015 int try_release_extent_mapping(struct extent_map_tree
*map
,
4016 struct extent_io_tree
*tree
, struct page
*page
,
4019 struct extent_map
*em
;
4020 u64 start
= page_offset(page
);
4021 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
4023 if ((mask
& __GFP_WAIT
) &&
4024 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
4026 while (start
<= end
) {
4027 len
= end
- start
+ 1;
4028 write_lock(&map
->lock
);
4029 em
= lookup_extent_mapping(map
, start
, len
);
4031 write_unlock(&map
->lock
);
4034 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
4035 em
->start
!= start
) {
4036 write_unlock(&map
->lock
);
4037 free_extent_map(em
);
4040 if (!test_range_bit(tree
, em
->start
,
4041 extent_map_end(em
) - 1,
4042 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
4044 remove_extent_mapping(map
, em
);
4045 /* once for the rb tree */
4046 free_extent_map(em
);
4048 start
= extent_map_end(em
);
4049 write_unlock(&map
->lock
);
4052 free_extent_map(em
);
4055 return try_release_extent_state(map
, tree
, page
, mask
);
4059 * helper function for fiemap, which doesn't want to see any holes.
4060 * This maps until we find something past 'last'
4062 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
4065 get_extent_t
*get_extent
)
4067 u64 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
4068 struct extent_map
*em
;
4075 len
= last
- offset
;
4078 len
= ALIGN(len
, sectorsize
);
4079 em
= get_extent(inode
, NULL
, 0, offset
, len
, 0);
4080 if (IS_ERR_OR_NULL(em
))
4083 /* if this isn't a hole return it */
4084 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
4085 em
->block_start
!= EXTENT_MAP_HOLE
) {
4089 /* this is a hole, advance to the next extent */
4090 offset
= extent_map_end(em
);
4091 free_extent_map(em
);
4098 static noinline
int count_ext_ref(u64 inum
, u64 offset
, u64 root_id
, void *ctx
)
4100 unsigned long cnt
= *((unsigned long *)ctx
);
4103 *((unsigned long *)ctx
) = cnt
;
4105 /* Now we're sure that the extent is shared. */
4111 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4112 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
4116 u64 max
= start
+ len
;
4120 u64 last_for_get_extent
= 0;
4122 u64 isize
= i_size_read(inode
);
4123 struct btrfs_key found_key
;
4124 struct extent_map
*em
= NULL
;
4125 struct extent_state
*cached_state
= NULL
;
4126 struct btrfs_path
*path
;
4135 path
= btrfs_alloc_path();
4138 path
->leave_spinning
= 1;
4140 start
= ALIGN(start
, BTRFS_I(inode
)->root
->sectorsize
);
4141 len
= ALIGN(len
, BTRFS_I(inode
)->root
->sectorsize
);
4144 * lookup the last file extent. We're not using i_size here
4145 * because there might be preallocation past i_size
4147 ret
= btrfs_lookup_file_extent(NULL
, BTRFS_I(inode
)->root
,
4148 path
, btrfs_ino(inode
), -1, 0);
4150 btrfs_free_path(path
);
4155 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
4156 found_type
= btrfs_key_type(&found_key
);
4158 /* No extents, but there might be delalloc bits */
4159 if (found_key
.objectid
!= btrfs_ino(inode
) ||
4160 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
4161 /* have to trust i_size as the end */
4163 last_for_get_extent
= isize
;
4166 * remember the start of the last extent. There are a
4167 * bunch of different factors that go into the length of the
4168 * extent, so its much less complex to remember where it started
4170 last
= found_key
.offset
;
4171 last_for_get_extent
= last
+ 1;
4173 btrfs_release_path(path
);
4176 * we might have some extents allocated but more delalloc past those
4177 * extents. so, we trust isize unless the start of the last extent is
4182 last_for_get_extent
= isize
;
4185 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1, 0,
4188 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4198 u64 offset_in_extent
= 0;
4200 /* break if the extent we found is outside the range */
4201 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4205 * get_extent may return an extent that starts before our
4206 * requested range. We have to make sure the ranges
4207 * we return to fiemap always move forward and don't
4208 * overlap, so adjust the offsets here
4210 em_start
= max(em
->start
, off
);
4213 * record the offset from the start of the extent
4214 * for adjusting the disk offset below. Only do this if the
4215 * extent isn't compressed since our in ram offset may be past
4216 * what we have actually allocated on disk.
4218 if (!test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4219 offset_in_extent
= em_start
- em
->start
;
4220 em_end
= extent_map_end(em
);
4221 em_len
= em_end
- em_start
;
4226 * bump off for our next call to get_extent
4228 off
= extent_map_end(em
);
4232 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4234 flags
|= FIEMAP_EXTENT_LAST
;
4235 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4236 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4237 FIEMAP_EXTENT_NOT_ALIGNED
);
4238 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4239 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4240 FIEMAP_EXTENT_UNKNOWN
);
4242 unsigned long ref_cnt
= 0;
4244 disko
= em
->block_start
+ offset_in_extent
;
4247 * As btrfs supports shared space, this information
4248 * can be exported to userspace tools via
4249 * flag FIEMAP_EXTENT_SHARED.
4251 ret
= iterate_inodes_from_logical(
4253 BTRFS_I(inode
)->root
->fs_info
,
4254 path
, count_ext_ref
, &ref_cnt
);
4255 if (ret
< 0 && ret
!= -ENOENT
)
4259 flags
|= FIEMAP_EXTENT_SHARED
;
4261 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4262 flags
|= FIEMAP_EXTENT_ENCODED
;
4264 free_extent_map(em
);
4266 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4267 (last
== (u64
)-1 && isize
<= em_end
)) {
4268 flags
|= FIEMAP_EXTENT_LAST
;
4272 /* now scan forward to see if this is really the last extent. */
4273 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4280 flags
|= FIEMAP_EXTENT_LAST
;
4283 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
4289 free_extent_map(em
);
4291 btrfs_free_path(path
);
4292 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4293 &cached_state
, GFP_NOFS
);
4297 static void __free_extent_buffer(struct extent_buffer
*eb
)
4299 btrfs_leak_debug_del(&eb
->leak_list
);
4300 kmem_cache_free(extent_buffer_cache
, eb
);
4303 static int extent_buffer_under_io(struct extent_buffer
*eb
)
4305 return (atomic_read(&eb
->io_pages
) ||
4306 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4307 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4311 * Helper for releasing extent buffer page.
4313 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
,
4314 unsigned long start_idx
)
4316 unsigned long index
;
4317 unsigned long num_pages
;
4319 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4321 BUG_ON(extent_buffer_under_io(eb
));
4323 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4324 index
= start_idx
+ num_pages
;
4325 if (start_idx
>= index
)
4330 page
= extent_buffer_page(eb
, index
);
4331 if (page
&& mapped
) {
4332 spin_lock(&page
->mapping
->private_lock
);
4334 * We do this since we'll remove the pages after we've
4335 * removed the eb from the radix tree, so we could race
4336 * and have this page now attached to the new eb. So
4337 * only clear page_private if it's still connected to
4340 if (PagePrivate(page
) &&
4341 page
->private == (unsigned long)eb
) {
4342 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4343 BUG_ON(PageDirty(page
));
4344 BUG_ON(PageWriteback(page
));
4346 * We need to make sure we haven't be attached
4349 ClearPagePrivate(page
);
4350 set_page_private(page
, 0);
4351 /* One for the page private */
4352 page_cache_release(page
);
4354 spin_unlock(&page
->mapping
->private_lock
);
4358 /* One for when we alloced the page */
4359 page_cache_release(page
);
4361 } while (index
!= start_idx
);
4365 * Helper for releasing the extent buffer.
4367 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4369 btrfs_release_extent_buffer_page(eb
, 0);
4370 __free_extent_buffer(eb
);
4373 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
4378 struct extent_buffer
*eb
= NULL
;
4380 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
4387 rwlock_init(&eb
->lock
);
4388 atomic_set(&eb
->write_locks
, 0);
4389 atomic_set(&eb
->read_locks
, 0);
4390 atomic_set(&eb
->blocking_readers
, 0);
4391 atomic_set(&eb
->blocking_writers
, 0);
4392 atomic_set(&eb
->spinning_readers
, 0);
4393 atomic_set(&eb
->spinning_writers
, 0);
4394 eb
->lock_nested
= 0;
4395 init_waitqueue_head(&eb
->write_lock_wq
);
4396 init_waitqueue_head(&eb
->read_lock_wq
);
4398 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4400 spin_lock_init(&eb
->refs_lock
);
4401 atomic_set(&eb
->refs
, 1);
4402 atomic_set(&eb
->io_pages
, 0);
4405 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4407 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4408 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4409 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4414 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4418 struct extent_buffer
*new;
4419 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4421 new = __alloc_extent_buffer(NULL
, src
->start
, src
->len
, GFP_NOFS
);
4425 for (i
= 0; i
< num_pages
; i
++) {
4426 p
= alloc_page(GFP_NOFS
);
4428 btrfs_release_extent_buffer(new);
4431 attach_extent_buffer_page(new, p
);
4432 WARN_ON(PageDirty(p
));
4437 copy_extent_buffer(new, src
, 0, 0, src
->len
);
4438 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4439 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4444 struct extent_buffer
*alloc_dummy_extent_buffer(u64 start
, unsigned long len
)
4446 struct extent_buffer
*eb
;
4447 unsigned long num_pages
= num_extent_pages(0, len
);
4450 eb
= __alloc_extent_buffer(NULL
, start
, len
, GFP_NOFS
);
4454 for (i
= 0; i
< num_pages
; i
++) {
4455 eb
->pages
[i
] = alloc_page(GFP_NOFS
);
4459 set_extent_buffer_uptodate(eb
);
4460 btrfs_set_header_nritems(eb
, 0);
4461 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4466 __free_page(eb
->pages
[i
- 1]);
4467 __free_extent_buffer(eb
);
4471 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4474 /* the ref bit is tricky. We have to make sure it is set
4475 * if we have the buffer dirty. Otherwise the
4476 * code to free a buffer can end up dropping a dirty
4479 * Once the ref bit is set, it won't go away while the
4480 * buffer is dirty or in writeback, and it also won't
4481 * go away while we have the reference count on the
4484 * We can't just set the ref bit without bumping the
4485 * ref on the eb because free_extent_buffer might
4486 * see the ref bit and try to clear it. If this happens
4487 * free_extent_buffer might end up dropping our original
4488 * ref by mistake and freeing the page before we are able
4489 * to add one more ref.
4491 * So bump the ref count first, then set the bit. If someone
4492 * beat us to it, drop the ref we added.
4494 refs
= atomic_read(&eb
->refs
);
4495 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4498 spin_lock(&eb
->refs_lock
);
4499 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4500 atomic_inc(&eb
->refs
);
4501 spin_unlock(&eb
->refs_lock
);
4504 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
)
4506 unsigned long num_pages
, i
;
4508 check_buffer_tree_ref(eb
);
4510 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4511 for (i
= 0; i
< num_pages
; i
++) {
4512 struct page
*p
= extent_buffer_page(eb
, i
);
4513 mark_page_accessed(p
);
4517 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
4520 struct extent_buffer
*eb
;
4523 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4524 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4526 mark_extent_buffer_accessed(eb
);
4534 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
4535 u64 start
, unsigned long len
)
4537 unsigned long num_pages
= num_extent_pages(start
, len
);
4539 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
4540 struct extent_buffer
*eb
;
4541 struct extent_buffer
*exists
= NULL
;
4543 struct address_space
*mapping
= tree
->mapping
;
4548 eb
= find_extent_buffer(tree
, start
);
4552 eb
= __alloc_extent_buffer(tree
, start
, len
, GFP_NOFS
);
4556 for (i
= 0; i
< num_pages
; i
++, index
++) {
4557 p
= find_or_create_page(mapping
, index
, GFP_NOFS
);
4561 spin_lock(&mapping
->private_lock
);
4562 if (PagePrivate(p
)) {
4564 * We could have already allocated an eb for this page
4565 * and attached one so lets see if we can get a ref on
4566 * the existing eb, and if we can we know it's good and
4567 * we can just return that one, else we know we can just
4568 * overwrite page->private.
4570 exists
= (struct extent_buffer
*)p
->private;
4571 if (atomic_inc_not_zero(&exists
->refs
)) {
4572 spin_unlock(&mapping
->private_lock
);
4574 page_cache_release(p
);
4575 mark_extent_buffer_accessed(exists
);
4580 * Do this so attach doesn't complain and we need to
4581 * drop the ref the old guy had.
4583 ClearPagePrivate(p
);
4584 WARN_ON(PageDirty(p
));
4585 page_cache_release(p
);
4587 attach_extent_buffer_page(eb
, p
);
4588 spin_unlock(&mapping
->private_lock
);
4589 WARN_ON(PageDirty(p
));
4590 mark_page_accessed(p
);
4592 if (!PageUptodate(p
))
4596 * see below about how we avoid a nasty race with release page
4597 * and why we unlock later
4601 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4603 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
4607 spin_lock(&tree
->buffer_lock
);
4608 ret
= radix_tree_insert(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
, eb
);
4609 spin_unlock(&tree
->buffer_lock
);
4610 radix_tree_preload_end();
4611 if (ret
== -EEXIST
) {
4612 exists
= find_extent_buffer(tree
, start
);
4618 /* add one reference for the tree */
4619 check_buffer_tree_ref(eb
);
4620 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
4623 * there is a race where release page may have
4624 * tried to find this extent buffer in the radix
4625 * but failed. It will tell the VM it is safe to
4626 * reclaim the, and it will clear the page private bit.
4627 * We must make sure to set the page private bit properly
4628 * after the extent buffer is in the radix tree so
4629 * it doesn't get lost
4631 SetPageChecked(eb
->pages
[0]);
4632 for (i
= 1; i
< num_pages
; i
++) {
4633 p
= extent_buffer_page(eb
, i
);
4634 ClearPageChecked(p
);
4637 unlock_page(eb
->pages
[0]);
4641 for (i
= 0; i
< num_pages
; i
++) {
4643 unlock_page(eb
->pages
[i
]);
4646 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
4647 btrfs_release_extent_buffer(eb
);
4651 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
4653 struct extent_buffer
*eb
=
4654 container_of(head
, struct extent_buffer
, rcu_head
);
4656 __free_extent_buffer(eb
);
4659 /* Expects to have eb->eb_lock already held */
4660 static int release_extent_buffer(struct extent_buffer
*eb
)
4662 WARN_ON(atomic_read(&eb
->refs
) == 0);
4663 if (atomic_dec_and_test(&eb
->refs
)) {
4664 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
)) {
4665 struct extent_io_tree
*tree
= eb
->tree
;
4667 spin_unlock(&eb
->refs_lock
);
4669 spin_lock(&tree
->buffer_lock
);
4670 radix_tree_delete(&tree
->buffer
,
4671 eb
->start
>> PAGE_CACHE_SHIFT
);
4672 spin_unlock(&tree
->buffer_lock
);
4674 spin_unlock(&eb
->refs_lock
);
4677 /* Should be safe to release our pages at this point */
4678 btrfs_release_extent_buffer_page(eb
, 0);
4679 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
4682 spin_unlock(&eb
->refs_lock
);
4687 void free_extent_buffer(struct extent_buffer
*eb
)
4695 refs
= atomic_read(&eb
->refs
);
4698 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
4703 spin_lock(&eb
->refs_lock
);
4704 if (atomic_read(&eb
->refs
) == 2 &&
4705 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
4706 atomic_dec(&eb
->refs
);
4708 if (atomic_read(&eb
->refs
) == 2 &&
4709 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
4710 !extent_buffer_under_io(eb
) &&
4711 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4712 atomic_dec(&eb
->refs
);
4715 * I know this is terrible, but it's temporary until we stop tracking
4716 * the uptodate bits and such for the extent buffers.
4718 release_extent_buffer(eb
);
4721 void free_extent_buffer_stale(struct extent_buffer
*eb
)
4726 spin_lock(&eb
->refs_lock
);
4727 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
4729 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
4730 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4731 atomic_dec(&eb
->refs
);
4732 release_extent_buffer(eb
);
4735 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
4738 unsigned long num_pages
;
4741 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4743 for (i
= 0; i
< num_pages
; i
++) {
4744 page
= extent_buffer_page(eb
, i
);
4745 if (!PageDirty(page
))
4749 WARN_ON(!PagePrivate(page
));
4751 clear_page_dirty_for_io(page
);
4752 spin_lock_irq(&page
->mapping
->tree_lock
);
4753 if (!PageDirty(page
)) {
4754 radix_tree_tag_clear(&page
->mapping
->page_tree
,
4756 PAGECACHE_TAG_DIRTY
);
4758 spin_unlock_irq(&page
->mapping
->tree_lock
);
4759 ClearPageError(page
);
4762 WARN_ON(atomic_read(&eb
->refs
) == 0);
4765 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
4768 unsigned long num_pages
;
4771 check_buffer_tree_ref(eb
);
4773 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
4775 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4776 WARN_ON(atomic_read(&eb
->refs
) == 0);
4777 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
4779 for (i
= 0; i
< num_pages
; i
++)
4780 set_page_dirty(extent_buffer_page(eb
, i
));
4784 int clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
4788 unsigned long num_pages
;
4790 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4791 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4792 for (i
= 0; i
< num_pages
; i
++) {
4793 page
= extent_buffer_page(eb
, i
);
4795 ClearPageUptodate(page
);
4800 int set_extent_buffer_uptodate(struct extent_buffer
*eb
)
4804 unsigned long num_pages
;
4806 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4807 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4808 for (i
= 0; i
< num_pages
; i
++) {
4809 page
= extent_buffer_page(eb
, i
);
4810 SetPageUptodate(page
);
4815 int extent_buffer_uptodate(struct extent_buffer
*eb
)
4817 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4820 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
4821 struct extent_buffer
*eb
, u64 start
, int wait
,
4822 get_extent_t
*get_extent
, int mirror_num
)
4825 unsigned long start_i
;
4829 int locked_pages
= 0;
4830 int all_uptodate
= 1;
4831 unsigned long num_pages
;
4832 unsigned long num_reads
= 0;
4833 struct bio
*bio
= NULL
;
4834 unsigned long bio_flags
= 0;
4836 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
4840 WARN_ON(start
< eb
->start
);
4841 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
4842 (eb
->start
>> PAGE_CACHE_SHIFT
);
4847 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4848 for (i
= start_i
; i
< num_pages
; i
++) {
4849 page
= extent_buffer_page(eb
, i
);
4850 if (wait
== WAIT_NONE
) {
4851 if (!trylock_page(page
))
4857 if (!PageUptodate(page
)) {
4864 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4868 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
4869 eb
->read_mirror
= 0;
4870 atomic_set(&eb
->io_pages
, num_reads
);
4871 for (i
= start_i
; i
< num_pages
; i
++) {
4872 page
= extent_buffer_page(eb
, i
);
4873 if (!PageUptodate(page
)) {
4874 ClearPageError(page
);
4875 err
= __extent_read_full_page(tree
, page
,
4877 mirror_num
, &bio_flags
,
4887 err
= submit_one_bio(READ
| REQ_META
, bio
, mirror_num
,
4893 if (ret
|| wait
!= WAIT_COMPLETE
)
4896 for (i
= start_i
; i
< num_pages
; i
++) {
4897 page
= extent_buffer_page(eb
, i
);
4898 wait_on_page_locked(page
);
4899 if (!PageUptodate(page
))
4907 while (locked_pages
> 0) {
4908 page
= extent_buffer_page(eb
, i
);
4916 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
4917 unsigned long start
,
4924 char *dst
= (char *)dstv
;
4925 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4926 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4928 WARN_ON(start
> eb
->len
);
4929 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4931 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4934 page
= extent_buffer_page(eb
, i
);
4936 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4937 kaddr
= page_address(page
);
4938 memcpy(dst
, kaddr
+ offset
, cur
);
4947 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
4948 unsigned long min_len
, char **map
,
4949 unsigned long *map_start
,
4950 unsigned long *map_len
)
4952 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
4955 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4956 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4957 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
4964 offset
= start_offset
;
4968 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
4971 if (start
+ min_len
> eb
->len
) {
4972 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
4974 eb
->start
, eb
->len
, start
, min_len
);
4978 p
= extent_buffer_page(eb
, i
);
4979 kaddr
= page_address(p
);
4980 *map
= kaddr
+ offset
;
4981 *map_len
= PAGE_CACHE_SIZE
- offset
;
4985 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
4986 unsigned long start
,
4993 char *ptr
= (char *)ptrv
;
4994 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4995 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4998 WARN_ON(start
> eb
->len
);
4999 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5001 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5004 page
= extent_buffer_page(eb
, i
);
5006 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
5008 kaddr
= page_address(page
);
5009 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
5021 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
5022 unsigned long start
, unsigned long len
)
5028 char *src
= (char *)srcv
;
5029 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5030 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5032 WARN_ON(start
> eb
->len
);
5033 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5035 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5038 page
= extent_buffer_page(eb
, i
);
5039 WARN_ON(!PageUptodate(page
));
5041 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
5042 kaddr
= page_address(page
);
5043 memcpy(kaddr
+ offset
, src
, cur
);
5052 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
5053 unsigned long start
, unsigned long len
)
5059 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5060 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5062 WARN_ON(start
> eb
->len
);
5063 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5065 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5068 page
= extent_buffer_page(eb
, i
);
5069 WARN_ON(!PageUptodate(page
));
5071 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
5072 kaddr
= page_address(page
);
5073 memset(kaddr
+ offset
, c
, cur
);
5081 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
5082 unsigned long dst_offset
, unsigned long src_offset
,
5085 u64 dst_len
= dst
->len
;
5090 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5091 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5093 WARN_ON(src
->len
!= dst_len
);
5095 offset
= (start_offset
+ dst_offset
) &
5096 (PAGE_CACHE_SIZE
- 1);
5099 page
= extent_buffer_page(dst
, i
);
5100 WARN_ON(!PageUptodate(page
));
5102 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
5104 kaddr
= page_address(page
);
5105 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
5114 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
5116 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
5117 return distance
< len
;
5120 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
5121 unsigned long dst_off
, unsigned long src_off
,
5124 char *dst_kaddr
= page_address(dst_page
);
5126 int must_memmove
= 0;
5128 if (dst_page
!= src_page
) {
5129 src_kaddr
= page_address(src_page
);
5131 src_kaddr
= dst_kaddr
;
5132 if (areas_overlap(src_off
, dst_off
, len
))
5137 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5139 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5142 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5143 unsigned long src_offset
, unsigned long len
)
5146 size_t dst_off_in_page
;
5147 size_t src_off_in_page
;
5148 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 dst 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 dst len %lu\n", dst_offset
, len
, dst
->len
);
5164 dst_off_in_page
= (start_offset
+ dst_offset
) &
5165 (PAGE_CACHE_SIZE
- 1);
5166 src_off_in_page
= (start_offset
+ src_offset
) &
5167 (PAGE_CACHE_SIZE
- 1);
5169 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5170 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
5172 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
5174 cur
= min_t(unsigned long, cur
,
5175 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
5177 copy_pages(extent_buffer_page(dst
, dst_i
),
5178 extent_buffer_page(dst
, src_i
),
5179 dst_off_in_page
, src_off_in_page
, cur
);
5187 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5188 unsigned long src_offset
, unsigned long len
)
5191 size_t dst_off_in_page
;
5192 size_t src_off_in_page
;
5193 unsigned long dst_end
= dst_offset
+ len
- 1;
5194 unsigned long src_end
= src_offset
+ len
- 1;
5195 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5196 unsigned long dst_i
;
5197 unsigned long src_i
;
5199 if (src_offset
+ len
> dst
->len
) {
5200 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5201 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
5204 if (dst_offset
+ len
> dst
->len
) {
5205 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5206 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
5209 if (dst_offset
< src_offset
) {
5210 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5214 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
5215 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
5217 dst_off_in_page
= (start_offset
+ dst_end
) &
5218 (PAGE_CACHE_SIZE
- 1);
5219 src_off_in_page
= (start_offset
+ src_end
) &
5220 (PAGE_CACHE_SIZE
- 1);
5222 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5223 cur
= min(cur
, dst_off_in_page
+ 1);
5224 copy_pages(extent_buffer_page(dst
, dst_i
),
5225 extent_buffer_page(dst
, src_i
),
5226 dst_off_in_page
- cur
+ 1,
5227 src_off_in_page
- cur
+ 1, cur
);
5235 int try_release_extent_buffer(struct page
*page
)
5237 struct extent_buffer
*eb
;
5240 * We need to make sure noboody is attaching this page to an eb right
5243 spin_lock(&page
->mapping
->private_lock
);
5244 if (!PagePrivate(page
)) {
5245 spin_unlock(&page
->mapping
->private_lock
);
5249 eb
= (struct extent_buffer
*)page
->private;
5253 * This is a little awful but should be ok, we need to make sure that
5254 * the eb doesn't disappear out from under us while we're looking at
5257 spin_lock(&eb
->refs_lock
);
5258 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
5259 spin_unlock(&eb
->refs_lock
);
5260 spin_unlock(&page
->mapping
->private_lock
);
5263 spin_unlock(&page
->mapping
->private_lock
);
5266 * If tree ref isn't set then we know the ref on this eb is a real ref,
5267 * so just return, this page will likely be freed soon anyway.
5269 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
5270 spin_unlock(&eb
->refs_lock
);
5274 return release_extent_buffer(eb
);