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"
18 #include "btrfs_inode.h"
20 #include "check-integrity.h"
22 #include "rcu-string.h"
24 static struct kmem_cache
*extent_state_cache
;
25 static struct kmem_cache
*extent_buffer_cache
;
26 static struct bio_set
*btrfs_bioset
;
28 #ifdef CONFIG_BTRFS_DEBUG
29 static LIST_HEAD(buffers
);
30 static LIST_HEAD(states
);
32 static DEFINE_SPINLOCK(leak_lock
);
35 void btrfs_leak_debug_add(struct list_head
*new, struct list_head
*head
)
39 spin_lock_irqsave(&leak_lock
, flags
);
41 spin_unlock_irqrestore(&leak_lock
, flags
);
45 void btrfs_leak_debug_del(struct list_head
*entry
)
49 spin_lock_irqsave(&leak_lock
, flags
);
51 spin_unlock_irqrestore(&leak_lock
, flags
);
55 void btrfs_leak_debug_check(void)
57 struct extent_state
*state
;
58 struct extent_buffer
*eb
;
60 while (!list_empty(&states
)) {
61 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
62 printk(KERN_ERR
"btrfs state leak: start %llu end %llu "
63 "state %lu in tree %p refs %d\n",
64 state
->start
, state
->end
, state
->state
, state
->tree
,
65 atomic_read(&state
->refs
));
66 list_del(&state
->leak_list
);
67 kmem_cache_free(extent_state_cache
, state
);
70 while (!list_empty(&buffers
)) {
71 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
72 printk(KERN_ERR
"btrfs buffer leak start %llu len %lu "
74 eb
->start
, eb
->len
, atomic_read(&eb
->refs
));
75 list_del(&eb
->leak_list
);
76 kmem_cache_free(extent_buffer_cache
, eb
);
80 #define btrfs_debug_check_extent_io_range(inode, start, end) \
81 __btrfs_debug_check_extent_io_range(__func__, (inode), (start), (end))
82 static inline void __btrfs_debug_check_extent_io_range(const char *caller
,
83 struct inode
*inode
, u64 start
, u64 end
)
85 u64 isize
= i_size_read(inode
);
87 if (end
>= PAGE_SIZE
&& (end
% 2) == 0 && end
!= isize
- 1) {
88 printk_ratelimited(KERN_DEBUG
89 "btrfs: %s: ino %llu isize %llu odd range [%llu,%llu]\n",
90 caller
, btrfs_ino(inode
), isize
, start
, end
);
94 #define btrfs_leak_debug_add(new, head) do {} while (0)
95 #define btrfs_leak_debug_del(entry) do {} while (0)
96 #define btrfs_leak_debug_check() do {} while (0)
97 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
100 #define BUFFER_LRU_MAX 64
105 struct rb_node rb_node
;
108 struct extent_page_data
{
110 struct extent_io_tree
*tree
;
111 get_extent_t
*get_extent
;
112 unsigned long bio_flags
;
114 /* tells writepage not to lock the state bits for this range
115 * it still does the unlocking
117 unsigned int extent_locked
:1;
119 /* tells the submit_bio code to use a WRITE_SYNC */
120 unsigned int sync_io
:1;
123 static noinline
void flush_write_bio(void *data
);
124 static inline struct btrfs_fs_info
*
125 tree_fs_info(struct extent_io_tree
*tree
)
127 return btrfs_sb(tree
->mapping
->host
->i_sb
);
130 int __init
extent_io_init(void)
132 extent_state_cache
= kmem_cache_create("btrfs_extent_state",
133 sizeof(struct extent_state
), 0,
134 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
135 if (!extent_state_cache
)
138 extent_buffer_cache
= kmem_cache_create("btrfs_extent_buffer",
139 sizeof(struct extent_buffer
), 0,
140 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
141 if (!extent_buffer_cache
)
142 goto free_state_cache
;
144 btrfs_bioset
= bioset_create(BIO_POOL_SIZE
,
145 offsetof(struct btrfs_io_bio
, bio
));
147 goto free_buffer_cache
;
151 kmem_cache_destroy(extent_buffer_cache
);
152 extent_buffer_cache
= NULL
;
155 kmem_cache_destroy(extent_state_cache
);
156 extent_state_cache
= NULL
;
160 void extent_io_exit(void)
162 btrfs_leak_debug_check();
165 * Make sure all delayed rcu free are flushed before we
169 if (extent_state_cache
)
170 kmem_cache_destroy(extent_state_cache
);
171 if (extent_buffer_cache
)
172 kmem_cache_destroy(extent_buffer_cache
);
174 bioset_free(btrfs_bioset
);
177 void extent_io_tree_init(struct extent_io_tree
*tree
,
178 struct address_space
*mapping
)
180 tree
->state
= RB_ROOT
;
181 INIT_RADIX_TREE(&tree
->buffer
, GFP_ATOMIC
);
183 tree
->dirty_bytes
= 0;
184 spin_lock_init(&tree
->lock
);
185 spin_lock_init(&tree
->buffer_lock
);
186 tree
->mapping
= mapping
;
189 static struct extent_state
*alloc_extent_state(gfp_t mask
)
191 struct extent_state
*state
;
193 state
= kmem_cache_alloc(extent_state_cache
, mask
);
199 btrfs_leak_debug_add(&state
->leak_list
, &states
);
200 atomic_set(&state
->refs
, 1);
201 init_waitqueue_head(&state
->wq
);
202 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
206 void free_extent_state(struct extent_state
*state
)
210 if (atomic_dec_and_test(&state
->refs
)) {
211 WARN_ON(state
->tree
);
212 btrfs_leak_debug_del(&state
->leak_list
);
213 trace_free_extent_state(state
, _RET_IP_
);
214 kmem_cache_free(extent_state_cache
, state
);
218 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
219 struct rb_node
*node
)
221 struct rb_node
**p
= &root
->rb_node
;
222 struct rb_node
*parent
= NULL
;
223 struct tree_entry
*entry
;
227 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
229 if (offset
< entry
->start
)
231 else if (offset
> entry
->end
)
237 rb_link_node(node
, parent
, p
);
238 rb_insert_color(node
, root
);
242 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
243 struct rb_node
**prev_ret
,
244 struct rb_node
**next_ret
)
246 struct rb_root
*root
= &tree
->state
;
247 struct rb_node
*n
= root
->rb_node
;
248 struct rb_node
*prev
= NULL
;
249 struct rb_node
*orig_prev
= NULL
;
250 struct tree_entry
*entry
;
251 struct tree_entry
*prev_entry
= NULL
;
254 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
258 if (offset
< entry
->start
)
260 else if (offset
> entry
->end
)
268 while (prev
&& offset
> prev_entry
->end
) {
269 prev
= rb_next(prev
);
270 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
277 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
278 while (prev
&& offset
< prev_entry
->start
) {
279 prev
= rb_prev(prev
);
280 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
287 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
290 struct rb_node
*prev
= NULL
;
293 ret
= __etree_search(tree
, offset
, &prev
, NULL
);
299 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
300 struct extent_state
*other
)
302 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
303 tree
->ops
->merge_extent_hook(tree
->mapping
->host
, new,
308 * utility function to look for merge candidates inside a given range.
309 * Any extents with matching state are merged together into a single
310 * extent in the tree. Extents with EXTENT_IO in their state field
311 * are not merged because the end_io handlers need to be able to do
312 * operations on them without sleeping (or doing allocations/splits).
314 * This should be called with the tree lock held.
316 static void merge_state(struct extent_io_tree
*tree
,
317 struct extent_state
*state
)
319 struct extent_state
*other
;
320 struct rb_node
*other_node
;
322 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
325 other_node
= rb_prev(&state
->rb_node
);
327 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
328 if (other
->end
== state
->start
- 1 &&
329 other
->state
== state
->state
) {
330 merge_cb(tree
, state
, other
);
331 state
->start
= other
->start
;
333 rb_erase(&other
->rb_node
, &tree
->state
);
334 free_extent_state(other
);
337 other_node
= rb_next(&state
->rb_node
);
339 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
340 if (other
->start
== state
->end
+ 1 &&
341 other
->state
== state
->state
) {
342 merge_cb(tree
, state
, other
);
343 state
->end
= other
->end
;
345 rb_erase(&other
->rb_node
, &tree
->state
);
346 free_extent_state(other
);
351 static void set_state_cb(struct extent_io_tree
*tree
,
352 struct extent_state
*state
, unsigned long *bits
)
354 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
355 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
, bits
);
358 static void clear_state_cb(struct extent_io_tree
*tree
,
359 struct extent_state
*state
, unsigned long *bits
)
361 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
362 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
, bits
);
365 static void set_state_bits(struct extent_io_tree
*tree
,
366 struct extent_state
*state
, unsigned long *bits
);
369 * insert an extent_state struct into the tree. 'bits' are set on the
370 * struct before it is inserted.
372 * This may return -EEXIST if the extent is already there, in which case the
373 * state struct is freed.
375 * The tree lock is not taken internally. This is a utility function and
376 * probably isn't what you want to call (see set/clear_extent_bit).
378 static int insert_state(struct extent_io_tree
*tree
,
379 struct extent_state
*state
, u64 start
, u64 end
,
382 struct rb_node
*node
;
385 WARN(1, KERN_ERR
"btrfs end < start %llu %llu\n",
387 state
->start
= start
;
390 set_state_bits(tree
, state
, bits
);
392 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
394 struct extent_state
*found
;
395 found
= rb_entry(node
, struct extent_state
, rb_node
);
396 printk(KERN_ERR
"btrfs found node %llu %llu on insert of "
398 found
->start
, found
->end
, start
, end
);
402 merge_state(tree
, state
);
406 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
409 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
410 tree
->ops
->split_extent_hook(tree
->mapping
->host
, orig
, split
);
414 * split a given extent state struct in two, inserting the preallocated
415 * struct 'prealloc' as the newly created second half. 'split' indicates an
416 * offset inside 'orig' where it should be split.
419 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
420 * are two extent state structs in the tree:
421 * prealloc: [orig->start, split - 1]
422 * orig: [ split, orig->end ]
424 * The tree locks are not taken by this function. They need to be held
427 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
428 struct extent_state
*prealloc
, u64 split
)
430 struct rb_node
*node
;
432 split_cb(tree
, orig
, split
);
434 prealloc
->start
= orig
->start
;
435 prealloc
->end
= split
- 1;
436 prealloc
->state
= orig
->state
;
439 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
441 free_extent_state(prealloc
);
444 prealloc
->tree
= tree
;
448 static struct extent_state
*next_state(struct extent_state
*state
)
450 struct rb_node
*next
= rb_next(&state
->rb_node
);
452 return rb_entry(next
, struct extent_state
, rb_node
);
458 * utility function to clear some bits in an extent state struct.
459 * it will optionally wake up any one waiting on this state (wake == 1).
461 * If no bits are set on the state struct after clearing things, the
462 * struct is freed and removed from the tree
464 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
465 struct extent_state
*state
,
466 unsigned long *bits
, int wake
)
468 struct extent_state
*next
;
469 unsigned long bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
471 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
472 u64 range
= state
->end
- state
->start
+ 1;
473 WARN_ON(range
> tree
->dirty_bytes
);
474 tree
->dirty_bytes
-= range
;
476 clear_state_cb(tree
, state
, bits
);
477 state
->state
&= ~bits_to_clear
;
480 if (state
->state
== 0) {
481 next
= next_state(state
);
483 rb_erase(&state
->rb_node
, &tree
->state
);
485 free_extent_state(state
);
490 merge_state(tree
, state
);
491 next
= next_state(state
);
496 static struct extent_state
*
497 alloc_extent_state_atomic(struct extent_state
*prealloc
)
500 prealloc
= alloc_extent_state(GFP_ATOMIC
);
505 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
507 btrfs_panic(tree_fs_info(tree
), err
, "Locking error: "
508 "Extent tree was modified by another "
509 "thread while locked.");
513 * clear some bits on a range in the tree. This may require splitting
514 * or inserting elements in the tree, so the gfp mask is used to
515 * indicate which allocations or sleeping are allowed.
517 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
518 * the given range from the tree regardless of state (ie for truncate).
520 * the range [start, end] is inclusive.
522 * This takes the tree lock, and returns 0 on success and < 0 on error.
524 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
525 unsigned long bits
, int wake
, int delete,
526 struct extent_state
**cached_state
,
529 struct extent_state
*state
;
530 struct extent_state
*cached
;
531 struct extent_state
*prealloc
= NULL
;
532 struct rb_node
*node
;
537 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
539 if (bits
& EXTENT_DELALLOC
)
540 bits
|= EXTENT_NORESERVE
;
543 bits
|= ~EXTENT_CTLBITS
;
544 bits
|= EXTENT_FIRST_DELALLOC
;
546 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
549 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
550 prealloc
= alloc_extent_state(mask
);
555 spin_lock(&tree
->lock
);
557 cached
= *cached_state
;
560 *cached_state
= NULL
;
564 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
565 cached
->end
> start
) {
567 atomic_dec(&cached
->refs
);
572 free_extent_state(cached
);
575 * this search will find the extents that end after
578 node
= tree_search(tree
, start
);
581 state
= rb_entry(node
, struct extent_state
, rb_node
);
583 if (state
->start
> end
)
585 WARN_ON(state
->end
< start
);
586 last_end
= state
->end
;
588 /* the state doesn't have the wanted bits, go ahead */
589 if (!(state
->state
& bits
)) {
590 state
= next_state(state
);
595 * | ---- desired range ---- |
597 * | ------------- state -------------- |
599 * We need to split the extent we found, and may flip
600 * bits on second half.
602 * If the extent we found extends past our range, we
603 * just split and search again. It'll get split again
604 * the next time though.
606 * If the extent we found is inside our range, we clear
607 * the desired bit on it.
610 if (state
->start
< start
) {
611 prealloc
= alloc_extent_state_atomic(prealloc
);
613 err
= split_state(tree
, state
, prealloc
, start
);
615 extent_io_tree_panic(tree
, err
);
620 if (state
->end
<= end
) {
621 state
= clear_state_bit(tree
, state
, &bits
, wake
);
627 * | ---- desired range ---- |
629 * We need to split the extent, and clear the bit
632 if (state
->start
<= end
&& state
->end
> end
) {
633 prealloc
= alloc_extent_state_atomic(prealloc
);
635 err
= split_state(tree
, state
, prealloc
, end
+ 1);
637 extent_io_tree_panic(tree
, err
);
642 clear_state_bit(tree
, prealloc
, &bits
, wake
);
648 state
= clear_state_bit(tree
, state
, &bits
, wake
);
650 if (last_end
== (u64
)-1)
652 start
= last_end
+ 1;
653 if (start
<= end
&& state
&& !need_resched())
658 spin_unlock(&tree
->lock
);
660 free_extent_state(prealloc
);
667 spin_unlock(&tree
->lock
);
668 if (mask
& __GFP_WAIT
)
673 static void wait_on_state(struct extent_io_tree
*tree
,
674 struct extent_state
*state
)
675 __releases(tree
->lock
)
676 __acquires(tree
->lock
)
679 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
680 spin_unlock(&tree
->lock
);
682 spin_lock(&tree
->lock
);
683 finish_wait(&state
->wq
, &wait
);
687 * waits for one or more bits to clear on a range in the state tree.
688 * The range [start, end] is inclusive.
689 * The tree lock is taken by this function
691 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
694 struct extent_state
*state
;
695 struct rb_node
*node
;
697 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
699 spin_lock(&tree
->lock
);
703 * this search will find all the extents that end after
706 node
= tree_search(tree
, start
);
710 state
= rb_entry(node
, struct extent_state
, rb_node
);
712 if (state
->start
> end
)
715 if (state
->state
& bits
) {
716 start
= state
->start
;
717 atomic_inc(&state
->refs
);
718 wait_on_state(tree
, state
);
719 free_extent_state(state
);
722 start
= state
->end
+ 1;
727 cond_resched_lock(&tree
->lock
);
730 spin_unlock(&tree
->lock
);
733 static void set_state_bits(struct extent_io_tree
*tree
,
734 struct extent_state
*state
,
737 unsigned long bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
739 set_state_cb(tree
, state
, bits
);
740 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
741 u64 range
= state
->end
- state
->start
+ 1;
742 tree
->dirty_bytes
+= range
;
744 state
->state
|= bits_to_set
;
747 static void cache_state(struct extent_state
*state
,
748 struct extent_state
**cached_ptr
)
750 if (cached_ptr
&& !(*cached_ptr
)) {
751 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
)) {
753 atomic_inc(&state
->refs
);
759 * set some bits on a range in the tree. This may require allocations or
760 * sleeping, so the gfp mask is used to indicate what is allowed.
762 * If any of the exclusive bits are set, this will fail with -EEXIST if some
763 * part of the range already has the desired bits set. The start of the
764 * existing range is returned in failed_start in this case.
766 * [start, end] is inclusive This takes the tree lock.
769 static int __must_check
770 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
771 unsigned long bits
, unsigned long exclusive_bits
,
772 u64
*failed_start
, struct extent_state
**cached_state
,
775 struct extent_state
*state
;
776 struct extent_state
*prealloc
= NULL
;
777 struct rb_node
*node
;
782 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
784 bits
|= EXTENT_FIRST_DELALLOC
;
786 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
787 prealloc
= alloc_extent_state(mask
);
791 spin_lock(&tree
->lock
);
792 if (cached_state
&& *cached_state
) {
793 state
= *cached_state
;
794 if (state
->start
<= start
&& state
->end
> start
&&
796 node
= &state
->rb_node
;
801 * this search will find all the extents that end after
804 node
= tree_search(tree
, start
);
806 prealloc
= alloc_extent_state_atomic(prealloc
);
808 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
810 extent_io_tree_panic(tree
, err
);
815 state
= rb_entry(node
, struct extent_state
, rb_node
);
817 last_start
= state
->start
;
818 last_end
= state
->end
;
821 * | ---- desired range ---- |
824 * Just lock what we found and keep going
826 if (state
->start
== start
&& state
->end
<= end
) {
827 if (state
->state
& exclusive_bits
) {
828 *failed_start
= state
->start
;
833 set_state_bits(tree
, state
, &bits
);
834 cache_state(state
, cached_state
);
835 merge_state(tree
, state
);
836 if (last_end
== (u64
)-1)
838 start
= last_end
+ 1;
839 state
= next_state(state
);
840 if (start
< end
&& state
&& state
->start
== start
&&
847 * | ---- desired range ---- |
850 * | ------------- state -------------- |
852 * We need to split the extent we found, and may flip bits on
855 * If the extent we found extends past our
856 * range, we just split and search again. It'll get split
857 * again the next time though.
859 * If the extent we found is inside our range, we set the
862 if (state
->start
< start
) {
863 if (state
->state
& exclusive_bits
) {
864 *failed_start
= start
;
869 prealloc
= alloc_extent_state_atomic(prealloc
);
871 err
= split_state(tree
, state
, prealloc
, start
);
873 extent_io_tree_panic(tree
, err
);
878 if (state
->end
<= end
) {
879 set_state_bits(tree
, state
, &bits
);
880 cache_state(state
, cached_state
);
881 merge_state(tree
, state
);
882 if (last_end
== (u64
)-1)
884 start
= last_end
+ 1;
885 state
= next_state(state
);
886 if (start
< end
&& state
&& state
->start
== start
&&
893 * | ---- desired range ---- |
894 * | state | or | state |
896 * There's a hole, we need to insert something in it and
897 * ignore the extent we found.
899 if (state
->start
> start
) {
901 if (end
< last_start
)
904 this_end
= last_start
- 1;
906 prealloc
= alloc_extent_state_atomic(prealloc
);
910 * Avoid to free 'prealloc' if it can be merged with
913 err
= insert_state(tree
, prealloc
, start
, this_end
,
916 extent_io_tree_panic(tree
, err
);
918 cache_state(prealloc
, cached_state
);
920 start
= this_end
+ 1;
924 * | ---- desired range ---- |
926 * We need to split the extent, and set the bit
929 if (state
->start
<= end
&& state
->end
> end
) {
930 if (state
->state
& exclusive_bits
) {
931 *failed_start
= start
;
936 prealloc
= alloc_extent_state_atomic(prealloc
);
938 err
= split_state(tree
, state
, prealloc
, end
+ 1);
940 extent_io_tree_panic(tree
, err
);
942 set_state_bits(tree
, prealloc
, &bits
);
943 cache_state(prealloc
, cached_state
);
944 merge_state(tree
, prealloc
);
952 spin_unlock(&tree
->lock
);
954 free_extent_state(prealloc
);
961 spin_unlock(&tree
->lock
);
962 if (mask
& __GFP_WAIT
)
967 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
968 unsigned long bits
, u64
* failed_start
,
969 struct extent_state
**cached_state
, gfp_t mask
)
971 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
977 * convert_extent_bit - convert all bits in a given range from one bit to
979 * @tree: the io tree to search
980 * @start: the start offset in bytes
981 * @end: the end offset in bytes (inclusive)
982 * @bits: the bits to set in this range
983 * @clear_bits: the bits to clear in this range
984 * @cached_state: state that we're going to cache
985 * @mask: the allocation mask
987 * This will go through and set bits for the given range. If any states exist
988 * already in this range they are set with the given bit and cleared of the
989 * clear_bits. This is only meant to be used by things that are mergeable, ie
990 * converting from say DELALLOC to DIRTY. This is not meant to be used with
991 * boundary bits like LOCK.
993 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
994 unsigned long bits
, unsigned long clear_bits
,
995 struct extent_state
**cached_state
, gfp_t mask
)
997 struct extent_state
*state
;
998 struct extent_state
*prealloc
= NULL
;
999 struct rb_node
*node
;
1004 btrfs_debug_check_extent_io_range(tree
->mapping
->host
, start
, end
);
1007 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
1008 prealloc
= alloc_extent_state(mask
);
1013 spin_lock(&tree
->lock
);
1014 if (cached_state
&& *cached_state
) {
1015 state
= *cached_state
;
1016 if (state
->start
<= start
&& state
->end
> start
&&
1018 node
= &state
->rb_node
;
1024 * this search will find all the extents that end after
1027 node
= tree_search(tree
, start
);
1029 prealloc
= alloc_extent_state_atomic(prealloc
);
1034 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
1037 extent_io_tree_panic(tree
, err
);
1040 state
= rb_entry(node
, struct extent_state
, rb_node
);
1042 last_start
= state
->start
;
1043 last_end
= state
->end
;
1046 * | ---- desired range ---- |
1049 * Just lock what we found and keep going
1051 if (state
->start
== start
&& state
->end
<= end
) {
1052 set_state_bits(tree
, state
, &bits
);
1053 cache_state(state
, cached_state
);
1054 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1055 if (last_end
== (u64
)-1)
1057 start
= last_end
+ 1;
1058 if (start
< end
&& state
&& state
->start
== start
&&
1065 * | ---- desired range ---- |
1068 * | ------------- state -------------- |
1070 * We need to split the extent we found, and may flip bits on
1073 * If the extent we found extends past our
1074 * range, we just split and search again. It'll get split
1075 * again the next time though.
1077 * If the extent we found is inside our range, we set the
1078 * desired bit on it.
1080 if (state
->start
< start
) {
1081 prealloc
= alloc_extent_state_atomic(prealloc
);
1086 err
= split_state(tree
, state
, prealloc
, start
);
1088 extent_io_tree_panic(tree
, err
);
1092 if (state
->end
<= end
) {
1093 set_state_bits(tree
, state
, &bits
);
1094 cache_state(state
, cached_state
);
1095 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1096 if (last_end
== (u64
)-1)
1098 start
= last_end
+ 1;
1099 if (start
< end
&& state
&& state
->start
== start
&&
1106 * | ---- desired range ---- |
1107 * | state | or | state |
1109 * There's a hole, we need to insert something in it and
1110 * ignore the extent we found.
1112 if (state
->start
> start
) {
1114 if (end
< last_start
)
1117 this_end
= last_start
- 1;
1119 prealloc
= alloc_extent_state_atomic(prealloc
);
1126 * Avoid to free 'prealloc' if it can be merged with
1129 err
= insert_state(tree
, prealloc
, start
, this_end
,
1132 extent_io_tree_panic(tree
, err
);
1133 cache_state(prealloc
, cached_state
);
1135 start
= this_end
+ 1;
1139 * | ---- desired range ---- |
1141 * We need to split the extent, and set the bit
1144 if (state
->start
<= end
&& state
->end
> end
) {
1145 prealloc
= alloc_extent_state_atomic(prealloc
);
1151 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1153 extent_io_tree_panic(tree
, err
);
1155 set_state_bits(tree
, prealloc
, &bits
);
1156 cache_state(prealloc
, cached_state
);
1157 clear_state_bit(tree
, prealloc
, &clear_bits
, 0);
1165 spin_unlock(&tree
->lock
);
1167 free_extent_state(prealloc
);
1174 spin_unlock(&tree
->lock
);
1175 if (mask
& __GFP_WAIT
)
1180 /* wrappers around set/clear extent bit */
1181 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1184 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, NULL
,
1188 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1189 unsigned long bits
, gfp_t mask
)
1191 return set_extent_bit(tree
, start
, end
, bits
, NULL
,
1195 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1196 unsigned long bits
, gfp_t mask
)
1198 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, mask
);
1201 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1202 struct extent_state
**cached_state
, gfp_t mask
)
1204 return set_extent_bit(tree
, start
, end
,
1205 EXTENT_DELALLOC
| EXTENT_UPTODATE
,
1206 NULL
, cached_state
, mask
);
1209 int set_extent_defrag(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1210 struct extent_state
**cached_state
, gfp_t mask
)
1212 return set_extent_bit(tree
, start
, end
,
1213 EXTENT_DELALLOC
| EXTENT_UPTODATE
| EXTENT_DEFRAG
,
1214 NULL
, cached_state
, mask
);
1217 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1220 return clear_extent_bit(tree
, start
, end
,
1221 EXTENT_DIRTY
| EXTENT_DELALLOC
|
1222 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
, mask
);
1225 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1228 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, NULL
,
1232 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1233 struct extent_state
**cached_state
, gfp_t mask
)
1235 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, NULL
,
1236 cached_state
, mask
);
1239 int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1240 struct extent_state
**cached_state
, gfp_t mask
)
1242 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0,
1243 cached_state
, mask
);
1247 * either insert or lock state struct between start and end use mask to tell
1248 * us if waiting is desired.
1250 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1251 unsigned long bits
, struct extent_state
**cached_state
)
1256 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
1257 EXTENT_LOCKED
, &failed_start
,
1258 cached_state
, GFP_NOFS
);
1259 if (err
== -EEXIST
) {
1260 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1261 start
= failed_start
;
1264 WARN_ON(start
> end
);
1269 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1271 return lock_extent_bits(tree
, start
, end
, 0, NULL
);
1274 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1279 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1280 &failed_start
, NULL
, GFP_NOFS
);
1281 if (err
== -EEXIST
) {
1282 if (failed_start
> start
)
1283 clear_extent_bit(tree
, start
, failed_start
- 1,
1284 EXTENT_LOCKED
, 1, 0, NULL
, GFP_NOFS
);
1290 int unlock_extent_cached(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1291 struct extent_state
**cached
, gfp_t mask
)
1293 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, cached
,
1297 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1299 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, NULL
,
1303 int extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1305 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1306 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1309 while (index
<= end_index
) {
1310 page
= find_get_page(inode
->i_mapping
, index
);
1311 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1312 clear_page_dirty_for_io(page
);
1313 page_cache_release(page
);
1319 int extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1321 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1322 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1325 while (index
<= end_index
) {
1326 page
= find_get_page(inode
->i_mapping
, index
);
1327 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1328 account_page_redirty(page
);
1329 __set_page_dirty_nobuffers(page
);
1330 page_cache_release(page
);
1337 * helper function to set both pages and extents in the tree writeback
1339 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1341 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1342 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1345 while (index
<= end_index
) {
1346 page
= find_get_page(tree
->mapping
, index
);
1347 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1348 set_page_writeback(page
);
1349 page_cache_release(page
);
1355 /* find the first state struct with 'bits' set after 'start', and
1356 * return it. tree->lock must be held. NULL will returned if
1357 * nothing was found after 'start'
1359 static struct extent_state
*
1360 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1361 u64 start
, unsigned long bits
)
1363 struct rb_node
*node
;
1364 struct extent_state
*state
;
1367 * this search will find all the extents that end after
1370 node
= tree_search(tree
, start
);
1375 state
= rb_entry(node
, struct extent_state
, rb_node
);
1376 if (state
->end
>= start
&& (state
->state
& bits
))
1379 node
= rb_next(node
);
1388 * find the first offset in the io tree with 'bits' set. zero is
1389 * returned if we find something, and *start_ret and *end_ret are
1390 * set to reflect the state struct that was found.
1392 * If nothing was found, 1 is returned. If found something, return 0.
1394 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1395 u64
*start_ret
, u64
*end_ret
, unsigned long bits
,
1396 struct extent_state
**cached_state
)
1398 struct extent_state
*state
;
1402 spin_lock(&tree
->lock
);
1403 if (cached_state
&& *cached_state
) {
1404 state
= *cached_state
;
1405 if (state
->end
== start
- 1 && state
->tree
) {
1406 n
= rb_next(&state
->rb_node
);
1408 state
= rb_entry(n
, struct extent_state
,
1410 if (state
->state
& bits
)
1414 free_extent_state(*cached_state
);
1415 *cached_state
= NULL
;
1418 free_extent_state(*cached_state
);
1419 *cached_state
= NULL
;
1422 state
= find_first_extent_bit_state(tree
, start
, bits
);
1425 cache_state(state
, cached_state
);
1426 *start_ret
= state
->start
;
1427 *end_ret
= state
->end
;
1431 spin_unlock(&tree
->lock
);
1436 * find a contiguous range of bytes in the file marked as delalloc, not
1437 * more than 'max_bytes'. start and end are used to return the range,
1439 * 1 is returned if we find something, 0 if nothing was in the tree
1441 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1442 u64
*start
, u64
*end
, u64 max_bytes
,
1443 struct extent_state
**cached_state
)
1445 struct rb_node
*node
;
1446 struct extent_state
*state
;
1447 u64 cur_start
= *start
;
1449 u64 total_bytes
= 0;
1451 spin_lock(&tree
->lock
);
1454 * this search will find all the extents that end after
1457 node
= tree_search(tree
, cur_start
);
1465 state
= rb_entry(node
, struct extent_state
, rb_node
);
1466 if (found
&& (state
->start
!= cur_start
||
1467 (state
->state
& EXTENT_BOUNDARY
))) {
1470 if (!(state
->state
& EXTENT_DELALLOC
)) {
1476 *start
= state
->start
;
1477 *cached_state
= state
;
1478 atomic_inc(&state
->refs
);
1482 cur_start
= state
->end
+ 1;
1483 node
= rb_next(node
);
1484 total_bytes
+= state
->end
- state
->start
+ 1;
1485 if (total_bytes
>= max_bytes
) {
1486 *end
= *start
+ max_bytes
- 1;
1493 spin_unlock(&tree
->lock
);
1497 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1498 struct page
*locked_page
,
1502 struct page
*pages
[16];
1503 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1504 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1505 unsigned long nr_pages
= end_index
- index
+ 1;
1508 if (index
== locked_page
->index
&& end_index
== index
)
1511 while (nr_pages
> 0) {
1512 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1513 min_t(unsigned long, nr_pages
,
1514 ARRAY_SIZE(pages
)), pages
);
1515 for (i
= 0; i
< ret
; i
++) {
1516 if (pages
[i
] != locked_page
)
1517 unlock_page(pages
[i
]);
1518 page_cache_release(pages
[i
]);
1526 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1527 struct page
*locked_page
,
1531 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1532 unsigned long start_index
= index
;
1533 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1534 unsigned long pages_locked
= 0;
1535 struct page
*pages
[16];
1536 unsigned long nrpages
;
1540 /* the caller is responsible for locking the start index */
1541 if (index
== locked_page
->index
&& index
== end_index
)
1544 /* skip the page at the start index */
1545 nrpages
= end_index
- index
+ 1;
1546 while (nrpages
> 0) {
1547 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1548 min_t(unsigned long,
1549 nrpages
, ARRAY_SIZE(pages
)), pages
);
1554 /* now we have an array of pages, lock them all */
1555 for (i
= 0; i
< ret
; i
++) {
1557 * the caller is taking responsibility for
1560 if (pages
[i
] != locked_page
) {
1561 lock_page(pages
[i
]);
1562 if (!PageDirty(pages
[i
]) ||
1563 pages
[i
]->mapping
!= inode
->i_mapping
) {
1565 unlock_page(pages
[i
]);
1566 page_cache_release(pages
[i
]);
1570 page_cache_release(pages
[i
]);
1579 if (ret
&& pages_locked
) {
1580 __unlock_for_delalloc(inode
, locked_page
,
1582 ((u64
)(start_index
+ pages_locked
- 1)) <<
1589 * find a contiguous range of bytes in the file marked as delalloc, not
1590 * more than 'max_bytes'. start and end are used to return the range,
1592 * 1 is returned if we find something, 0 if nothing was in the tree
1594 static noinline u64
find_lock_delalloc_range(struct inode
*inode
,
1595 struct extent_io_tree
*tree
,
1596 struct page
*locked_page
,
1597 u64
*start
, u64
*end
,
1603 struct extent_state
*cached_state
= NULL
;
1608 /* step one, find a bunch of delalloc bytes starting at start */
1609 delalloc_start
= *start
;
1611 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1612 max_bytes
, &cached_state
);
1613 if (!found
|| delalloc_end
<= *start
) {
1614 *start
= delalloc_start
;
1615 *end
= delalloc_end
;
1616 free_extent_state(cached_state
);
1621 * start comes from the offset of locked_page. We have to lock
1622 * pages in order, so we can't process delalloc bytes before
1625 if (delalloc_start
< *start
)
1626 delalloc_start
= *start
;
1629 * make sure to limit the number of pages we try to lock down
1632 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
&& loops
)
1633 delalloc_end
= delalloc_start
+ PAGE_CACHE_SIZE
- 1;
1635 /* step two, lock all the pages after the page that has start */
1636 ret
= lock_delalloc_pages(inode
, locked_page
,
1637 delalloc_start
, delalloc_end
);
1638 if (ret
== -EAGAIN
) {
1639 /* some of the pages are gone, lets avoid looping by
1640 * shortening the size of the delalloc range we're searching
1642 free_extent_state(cached_state
);
1644 unsigned long offset
= (*start
) & (PAGE_CACHE_SIZE
- 1);
1645 max_bytes
= PAGE_CACHE_SIZE
- offset
;
1653 BUG_ON(ret
); /* Only valid values are 0 and -EAGAIN */
1655 /* step three, lock the state bits for the whole range */
1656 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, 0, &cached_state
);
1658 /* then test to make sure it is all still delalloc */
1659 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1660 EXTENT_DELALLOC
, 1, cached_state
);
1662 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1663 &cached_state
, GFP_NOFS
);
1664 __unlock_for_delalloc(inode
, locked_page
,
1665 delalloc_start
, delalloc_end
);
1669 free_extent_state(cached_state
);
1670 *start
= delalloc_start
;
1671 *end
= delalloc_end
;
1676 int extent_clear_unlock_delalloc(struct inode
*inode
, u64 start
, u64 end
,
1677 struct page
*locked_page
,
1678 unsigned long clear_bits
,
1679 unsigned long page_ops
)
1681 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
1683 struct page
*pages
[16];
1684 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1685 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1686 unsigned long nr_pages
= end_index
- index
+ 1;
1689 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, NULL
, GFP_NOFS
);
1693 while (nr_pages
> 0) {
1694 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1695 min_t(unsigned long,
1696 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1697 for (i
= 0; i
< ret
; i
++) {
1699 if (page_ops
& PAGE_SET_PRIVATE2
)
1700 SetPagePrivate2(pages
[i
]);
1702 if (pages
[i
] == locked_page
) {
1703 page_cache_release(pages
[i
]);
1706 if (page_ops
& PAGE_CLEAR_DIRTY
)
1707 clear_page_dirty_for_io(pages
[i
]);
1708 if (page_ops
& PAGE_SET_WRITEBACK
)
1709 set_page_writeback(pages
[i
]);
1710 if (page_ops
& PAGE_END_WRITEBACK
)
1711 end_page_writeback(pages
[i
]);
1712 if (page_ops
& PAGE_UNLOCK
)
1713 unlock_page(pages
[i
]);
1714 page_cache_release(pages
[i
]);
1724 * count the number of bytes in the tree that have a given bit(s)
1725 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1726 * cached. The total number found is returned.
1728 u64
count_range_bits(struct extent_io_tree
*tree
,
1729 u64
*start
, u64 search_end
, u64 max_bytes
,
1730 unsigned long bits
, int contig
)
1732 struct rb_node
*node
;
1733 struct extent_state
*state
;
1734 u64 cur_start
= *start
;
1735 u64 total_bytes
= 0;
1739 if (search_end
<= cur_start
) {
1744 spin_lock(&tree
->lock
);
1745 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1746 total_bytes
= tree
->dirty_bytes
;
1750 * this search will find all the extents that end after
1753 node
= tree_search(tree
, cur_start
);
1758 state
= rb_entry(node
, struct extent_state
, rb_node
);
1759 if (state
->start
> search_end
)
1761 if (contig
&& found
&& state
->start
> last
+ 1)
1763 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1764 total_bytes
+= min(search_end
, state
->end
) + 1 -
1765 max(cur_start
, state
->start
);
1766 if (total_bytes
>= max_bytes
)
1769 *start
= max(cur_start
, state
->start
);
1773 } else if (contig
&& found
) {
1776 node
= rb_next(node
);
1781 spin_unlock(&tree
->lock
);
1786 * set the private field for a given byte offset in the tree. If there isn't
1787 * an extent_state there already, this does nothing.
1789 static int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1791 struct rb_node
*node
;
1792 struct extent_state
*state
;
1795 spin_lock(&tree
->lock
);
1797 * this search will find all the extents that end after
1800 node
= tree_search(tree
, start
);
1805 state
= rb_entry(node
, struct extent_state
, rb_node
);
1806 if (state
->start
!= start
) {
1810 state
->private = private;
1812 spin_unlock(&tree
->lock
);
1816 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1818 struct rb_node
*node
;
1819 struct extent_state
*state
;
1822 spin_lock(&tree
->lock
);
1824 * this search will find all the extents that end after
1827 node
= tree_search(tree
, start
);
1832 state
= rb_entry(node
, struct extent_state
, rb_node
);
1833 if (state
->start
!= start
) {
1837 *private = state
->private;
1839 spin_unlock(&tree
->lock
);
1844 * searches a range in the state tree for a given mask.
1845 * If 'filled' == 1, this returns 1 only if every extent in the tree
1846 * has the bits set. Otherwise, 1 is returned if any bit in the
1847 * range is found set.
1849 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1850 unsigned long bits
, int filled
, struct extent_state
*cached
)
1852 struct extent_state
*state
= NULL
;
1853 struct rb_node
*node
;
1856 spin_lock(&tree
->lock
);
1857 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
1858 cached
->end
> start
)
1859 node
= &cached
->rb_node
;
1861 node
= tree_search(tree
, start
);
1862 while (node
&& start
<= end
) {
1863 state
= rb_entry(node
, struct extent_state
, rb_node
);
1865 if (filled
&& state
->start
> start
) {
1870 if (state
->start
> end
)
1873 if (state
->state
& bits
) {
1877 } else if (filled
) {
1882 if (state
->end
== (u64
)-1)
1885 start
= state
->end
+ 1;
1888 node
= rb_next(node
);
1895 spin_unlock(&tree
->lock
);
1900 * helper function to set a given page up to date if all the
1901 * extents in the tree for that page are up to date
1903 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
1905 u64 start
= page_offset(page
);
1906 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1907 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1908 SetPageUptodate(page
);
1912 * When IO fails, either with EIO or csum verification fails, we
1913 * try other mirrors that might have a good copy of the data. This
1914 * io_failure_record is used to record state as we go through all the
1915 * mirrors. If another mirror has good data, the page is set up to date
1916 * and things continue. If a good mirror can't be found, the original
1917 * bio end_io callback is called to indicate things have failed.
1919 struct io_failure_record
{
1924 unsigned long bio_flags
;
1930 static int free_io_failure(struct inode
*inode
, struct io_failure_record
*rec
,
1935 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
1937 set_state_private(failure_tree
, rec
->start
, 0);
1938 ret
= clear_extent_bits(failure_tree
, rec
->start
,
1939 rec
->start
+ rec
->len
- 1,
1940 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
1944 ret
= clear_extent_bits(&BTRFS_I(inode
)->io_tree
, rec
->start
,
1945 rec
->start
+ rec
->len
- 1,
1946 EXTENT_DAMAGED
, GFP_NOFS
);
1954 static void repair_io_failure_callback(struct bio
*bio
, int err
)
1956 complete(bio
->bi_private
);
1960 * this bypasses the standard btrfs submit functions deliberately, as
1961 * the standard behavior is to write all copies in a raid setup. here we only
1962 * want to write the one bad copy. so we do the mapping for ourselves and issue
1963 * submit_bio directly.
1964 * to avoid any synchronization issues, wait for the data after writing, which
1965 * actually prevents the read that triggered the error from finishing.
1966 * currently, there can be no more than two copies of every data bit. thus,
1967 * exactly one rewrite is required.
1969 int repair_io_failure(struct btrfs_fs_info
*fs_info
, u64 start
,
1970 u64 length
, u64 logical
, struct page
*page
,
1974 struct btrfs_device
*dev
;
1975 DECLARE_COMPLETION_ONSTACK(compl);
1978 struct btrfs_bio
*bbio
= NULL
;
1979 struct btrfs_mapping_tree
*map_tree
= &fs_info
->mapping_tree
;
1982 BUG_ON(!mirror_num
);
1984 /* we can't repair anything in raid56 yet */
1985 if (btrfs_is_parity_mirror(map_tree
, logical
, length
, mirror_num
))
1988 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
1991 bio
->bi_private
= &compl;
1992 bio
->bi_end_io
= repair_io_failure_callback
;
1994 map_length
= length
;
1996 ret
= btrfs_map_block(fs_info
, WRITE
, logical
,
1997 &map_length
, &bbio
, mirror_num
);
2002 BUG_ON(mirror_num
!= bbio
->mirror_num
);
2003 sector
= bbio
->stripes
[mirror_num
-1].physical
>> 9;
2004 bio
->bi_sector
= sector
;
2005 dev
= bbio
->stripes
[mirror_num
-1].dev
;
2007 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2011 bio
->bi_bdev
= dev
->bdev
;
2012 bio_add_page(bio
, page
, length
, start
- page_offset(page
));
2013 btrfsic_submit_bio(WRITE_SYNC
, bio
);
2014 wait_for_completion(&compl);
2016 if (!test_bit(BIO_UPTODATE
, &bio
->bi_flags
)) {
2017 /* try to remap that extent elsewhere? */
2019 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2023 printk_ratelimited_in_rcu(KERN_INFO
"btrfs read error corrected: ino %lu off %llu "
2024 "(dev %s sector %llu)\n", page
->mapping
->host
->i_ino
,
2025 start
, rcu_str_deref(dev
->name
), sector
);
2031 int repair_eb_io_failure(struct btrfs_root
*root
, struct extent_buffer
*eb
,
2034 u64 start
= eb
->start
;
2035 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2038 for (i
= 0; i
< num_pages
; i
++) {
2039 struct page
*p
= extent_buffer_page(eb
, i
);
2040 ret
= repair_io_failure(root
->fs_info
, start
, PAGE_CACHE_SIZE
,
2041 start
, p
, mirror_num
);
2044 start
+= PAGE_CACHE_SIZE
;
2051 * each time an IO finishes, we do a fast check in the IO failure tree
2052 * to see if we need to process or clean up an io_failure_record
2054 static int clean_io_failure(u64 start
, struct page
*page
)
2057 u64 private_failure
;
2058 struct io_failure_record
*failrec
;
2059 struct btrfs_fs_info
*fs_info
;
2060 struct extent_state
*state
;
2064 struct inode
*inode
= page
->mapping
->host
;
2067 ret
= count_range_bits(&BTRFS_I(inode
)->io_failure_tree
, &private,
2068 (u64
)-1, 1, EXTENT_DIRTY
, 0);
2072 ret
= get_state_private(&BTRFS_I(inode
)->io_failure_tree
, start
,
2077 failrec
= (struct io_failure_record
*)(unsigned long) private_failure
;
2078 BUG_ON(!failrec
->this_mirror
);
2080 if (failrec
->in_validation
) {
2081 /* there was no real error, just free the record */
2082 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2088 spin_lock(&BTRFS_I(inode
)->io_tree
.lock
);
2089 state
= find_first_extent_bit_state(&BTRFS_I(inode
)->io_tree
,
2092 spin_unlock(&BTRFS_I(inode
)->io_tree
.lock
);
2094 if (state
&& state
->start
<= failrec
->start
&&
2095 state
->end
>= failrec
->start
+ failrec
->len
- 1) {
2096 fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2097 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2099 if (num_copies
> 1) {
2100 ret
= repair_io_failure(fs_info
, start
, failrec
->len
,
2101 failrec
->logical
, page
,
2102 failrec
->failed_mirror
);
2110 ret
= free_io_failure(inode
, failrec
, did_repair
);
2116 * this is a generic handler for readpage errors (default
2117 * readpage_io_failed_hook). if other copies exist, read those and write back
2118 * good data to the failed position. does not investigate in remapping the
2119 * failed extent elsewhere, hoping the device will be smart enough to do this as
2123 static int bio_readpage_error(struct bio
*failed_bio
, u64 phy_offset
,
2124 struct page
*page
, u64 start
, u64 end
,
2127 struct io_failure_record
*failrec
= NULL
;
2129 struct extent_map
*em
;
2130 struct inode
*inode
= page
->mapping
->host
;
2131 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2132 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2133 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2135 struct btrfs_io_bio
*btrfs_failed_bio
;
2136 struct btrfs_io_bio
*btrfs_bio
;
2142 BUG_ON(failed_bio
->bi_rw
& REQ_WRITE
);
2144 ret
= get_state_private(failure_tree
, start
, &private);
2146 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2149 failrec
->start
= start
;
2150 failrec
->len
= end
- start
+ 1;
2151 failrec
->this_mirror
= 0;
2152 failrec
->bio_flags
= 0;
2153 failrec
->in_validation
= 0;
2155 read_lock(&em_tree
->lock
);
2156 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2158 read_unlock(&em_tree
->lock
);
2163 if (em
->start
> start
|| em
->start
+ em
->len
< start
) {
2164 free_extent_map(em
);
2167 read_unlock(&em_tree
->lock
);
2173 logical
= start
- em
->start
;
2174 logical
= em
->block_start
+ logical
;
2175 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2176 logical
= em
->block_start
;
2177 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2178 extent_set_compress_type(&failrec
->bio_flags
,
2181 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2182 "len=%llu\n", logical
, start
, failrec
->len
);
2183 failrec
->logical
= logical
;
2184 free_extent_map(em
);
2186 /* set the bits in the private failure tree */
2187 ret
= set_extent_bits(failure_tree
, start
, end
,
2188 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
2190 ret
= set_state_private(failure_tree
, start
,
2191 (u64
)(unsigned long)failrec
);
2192 /* set the bits in the inode's tree */
2194 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
,
2201 failrec
= (struct io_failure_record
*)(unsigned long)private;
2202 pr_debug("bio_readpage_error: (found) logical=%llu, "
2203 "start=%llu, len=%llu, validation=%d\n",
2204 failrec
->logical
, failrec
->start
, failrec
->len
,
2205 failrec
->in_validation
);
2207 * when data can be on disk more than twice, add to failrec here
2208 * (e.g. with a list for failed_mirror) to make
2209 * clean_io_failure() clean all those errors at once.
2212 num_copies
= btrfs_num_copies(BTRFS_I(inode
)->root
->fs_info
,
2213 failrec
->logical
, failrec
->len
);
2214 if (num_copies
== 1) {
2216 * we only have a single copy of the data, so don't bother with
2217 * all the retry and error correction code that follows. no
2218 * matter what the error is, it is very likely to persist.
2220 pr_debug("bio_readpage_error: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
2221 num_copies
, failrec
->this_mirror
, failed_mirror
);
2222 free_io_failure(inode
, failrec
, 0);
2227 * there are two premises:
2228 * a) deliver good data to the caller
2229 * b) correct the bad sectors on disk
2231 if (failed_bio
->bi_vcnt
> 1) {
2233 * to fulfill b), we need to know the exact failing sectors, as
2234 * we don't want to rewrite any more than the failed ones. thus,
2235 * we need separate read requests for the failed bio
2237 * if the following BUG_ON triggers, our validation request got
2238 * merged. we need separate requests for our algorithm to work.
2240 BUG_ON(failrec
->in_validation
);
2241 failrec
->in_validation
= 1;
2242 failrec
->this_mirror
= failed_mirror
;
2243 read_mode
= READ_SYNC
| REQ_FAILFAST_DEV
;
2246 * we're ready to fulfill a) and b) alongside. get a good copy
2247 * of the failed sector and if we succeed, we have setup
2248 * everything for repair_io_failure to do the rest for us.
2250 if (failrec
->in_validation
) {
2251 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2252 failrec
->in_validation
= 0;
2253 failrec
->this_mirror
= 0;
2255 failrec
->failed_mirror
= failed_mirror
;
2256 failrec
->this_mirror
++;
2257 if (failrec
->this_mirror
== failed_mirror
)
2258 failrec
->this_mirror
++;
2259 read_mode
= READ_SYNC
;
2262 if (failrec
->this_mirror
> num_copies
) {
2263 pr_debug("bio_readpage_error: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
2264 num_copies
, failrec
->this_mirror
, failed_mirror
);
2265 free_io_failure(inode
, failrec
, 0);
2269 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2271 free_io_failure(inode
, failrec
, 0);
2274 bio
->bi_end_io
= failed_bio
->bi_end_io
;
2275 bio
->bi_sector
= failrec
->logical
>> 9;
2276 bio
->bi_bdev
= BTRFS_I(inode
)->root
->fs_info
->fs_devices
->latest_bdev
;
2279 btrfs_failed_bio
= btrfs_io_bio(failed_bio
);
2280 if (btrfs_failed_bio
->csum
) {
2281 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2282 u16 csum_size
= btrfs_super_csum_size(fs_info
->super_copy
);
2284 btrfs_bio
= btrfs_io_bio(bio
);
2285 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
2286 phy_offset
>>= inode
->i_sb
->s_blocksize_bits
;
2287 phy_offset
*= csum_size
;
2288 memcpy(btrfs_bio
->csum
, btrfs_failed_bio
->csum
+ phy_offset
,
2292 bio_add_page(bio
, page
, failrec
->len
, start
- page_offset(page
));
2294 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2295 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode
,
2296 failrec
->this_mirror
, num_copies
, failrec
->in_validation
);
2298 ret
= tree
->ops
->submit_bio_hook(inode
, read_mode
, bio
,
2299 failrec
->this_mirror
,
2300 failrec
->bio_flags
, 0);
2304 /* lots and lots of room for performance fixes in the end_bio funcs */
2306 int end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2308 int uptodate
= (err
== 0);
2309 struct extent_io_tree
*tree
;
2312 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2314 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
2315 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
2316 end
, NULL
, uptodate
);
2322 ClearPageUptodate(page
);
2329 * after a writepage IO is done, we need to:
2330 * clear the uptodate bits on error
2331 * clear the writeback bits in the extent tree for this IO
2332 * end_page_writeback if the page has no more pending IO
2334 * Scheduling is not allowed, so the extent state tree is expected
2335 * to have one and only one object corresponding to this IO.
2337 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
2339 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2340 struct extent_io_tree
*tree
;
2345 struct page
*page
= bvec
->bv_page
;
2346 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2348 /* We always issue full-page reads, but if some block
2349 * in a page fails to read, blk_update_request() will
2350 * advance bv_offset and adjust bv_len to compensate.
2351 * Print a warning for nonzero offsets, and an error
2352 * if they don't add up to a full page. */
2353 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2354 printk("%s page write in btrfs with offset %u and length %u\n",
2355 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2356 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2357 bvec
->bv_offset
, bvec
->bv_len
);
2359 start
= page_offset(page
);
2360 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2362 if (--bvec
>= bio
->bi_io_vec
)
2363 prefetchw(&bvec
->bv_page
->flags
);
2365 if (end_extent_writepage(page
, err
, start
, end
))
2368 end_page_writeback(page
);
2369 } while (bvec
>= bio
->bi_io_vec
);
2375 endio_readpage_release_extent(struct extent_io_tree
*tree
, u64 start
, u64 len
,
2378 struct extent_state
*cached
= NULL
;
2379 u64 end
= start
+ len
- 1;
2381 if (uptodate
&& tree
->track_uptodate
)
2382 set_extent_uptodate(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2383 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2387 * after a readpage IO is done, we need to:
2388 * clear the uptodate bits on error
2389 * set the uptodate bits if things worked
2390 * set the page up to date if all extents in the tree are uptodate
2391 * clear the lock bit in the extent tree
2392 * unlock the page if there are no other extents locked for it
2394 * Scheduling is not allowed, so the extent state tree is expected
2395 * to have one and only one object corresponding to this IO.
2397 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
2399 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2400 struct bio_vec
*bvec_end
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2401 struct bio_vec
*bvec
= bio
->bi_io_vec
;
2402 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2403 struct extent_io_tree
*tree
;
2408 u64 extent_start
= 0;
2417 struct page
*page
= bvec
->bv_page
;
2418 struct inode
*inode
= page
->mapping
->host
;
2420 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2421 "mirror=%lu\n", (u64
)bio
->bi_sector
, err
,
2422 io_bio
->mirror_num
);
2423 tree
= &BTRFS_I(inode
)->io_tree
;
2425 /* We always issue full-page reads, but if some block
2426 * in a page fails to read, blk_update_request() will
2427 * advance bv_offset and adjust bv_len to compensate.
2428 * Print a warning for nonzero offsets, and an error
2429 * if they don't add up to a full page. */
2430 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2431 printk("%s page read in btrfs with offset %u and length %u\n",
2432 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2433 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2434 bvec
->bv_offset
, bvec
->bv_len
);
2436 start
= page_offset(page
);
2437 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2440 if (++bvec
<= bvec_end
)
2441 prefetchw(&bvec
->bv_page
->flags
);
2443 mirror
= io_bio
->mirror_num
;
2444 if (likely(uptodate
&& tree
->ops
&&
2445 tree
->ops
->readpage_end_io_hook
)) {
2446 ret
= tree
->ops
->readpage_end_io_hook(io_bio
, offset
,
2452 clean_io_failure(start
, page
);
2455 if (likely(uptodate
))
2458 if (tree
->ops
&& tree
->ops
->readpage_io_failed_hook
) {
2459 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2461 test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
2465 * The generic bio_readpage_error handles errors the
2466 * following way: If possible, new read requests are
2467 * created and submitted and will end up in
2468 * end_bio_extent_readpage as well (if we're lucky, not
2469 * in the !uptodate case). In that case it returns 0 and
2470 * we just go on with the next page in our bio. If it
2471 * can't handle the error it will return -EIO and we
2472 * remain responsible for that page.
2474 ret
= bio_readpage_error(bio
, offset
, page
, start
, end
,
2478 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2485 if (likely(uptodate
)) {
2486 loff_t i_size
= i_size_read(inode
);
2487 pgoff_t end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2490 /* Zero out the end if this page straddles i_size */
2491 offset
= i_size
& (PAGE_CACHE_SIZE
-1);
2492 if (page
->index
== end_index
&& offset
)
2493 zero_user_segment(page
, offset
, PAGE_CACHE_SIZE
);
2494 SetPageUptodate(page
);
2496 ClearPageUptodate(page
);
2502 if (unlikely(!uptodate
)) {
2504 endio_readpage_release_extent(tree
,
2510 endio_readpage_release_extent(tree
, start
,
2511 end
- start
+ 1, 0);
2512 } else if (!extent_len
) {
2513 extent_start
= start
;
2514 extent_len
= end
+ 1 - start
;
2515 } else if (extent_start
+ extent_len
== start
) {
2516 extent_len
+= end
+ 1 - start
;
2518 endio_readpage_release_extent(tree
, extent_start
,
2519 extent_len
, uptodate
);
2520 extent_start
= start
;
2521 extent_len
= end
+ 1 - start
;
2523 } while (bvec
<= bvec_end
);
2526 endio_readpage_release_extent(tree
, extent_start
, extent_len
,
2529 io_bio
->end_io(io_bio
, err
);
2534 * this allocates from the btrfs_bioset. We're returning a bio right now
2535 * but you can call btrfs_io_bio for the appropriate container_of magic
2538 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
2541 struct btrfs_io_bio
*btrfs_bio
;
2544 bio
= bio_alloc_bioset(gfp_flags
, nr_vecs
, btrfs_bioset
);
2546 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
2547 while (!bio
&& (nr_vecs
/= 2)) {
2548 bio
= bio_alloc_bioset(gfp_flags
,
2549 nr_vecs
, btrfs_bioset
);
2555 bio
->bi_bdev
= bdev
;
2556 bio
->bi_sector
= first_sector
;
2557 btrfs_bio
= btrfs_io_bio(bio
);
2558 btrfs_bio
->csum
= NULL
;
2559 btrfs_bio
->csum_allocated
= NULL
;
2560 btrfs_bio
->end_io
= NULL
;
2565 struct bio
*btrfs_bio_clone(struct bio
*bio
, gfp_t gfp_mask
)
2567 return bio_clone_bioset(bio
, gfp_mask
, btrfs_bioset
);
2571 /* this also allocates from the btrfs_bioset */
2572 struct bio
*btrfs_io_bio_alloc(gfp_t gfp_mask
, unsigned int nr_iovecs
)
2574 struct btrfs_io_bio
*btrfs_bio
;
2577 bio
= bio_alloc_bioset(gfp_mask
, nr_iovecs
, btrfs_bioset
);
2579 btrfs_bio
= btrfs_io_bio(bio
);
2580 btrfs_bio
->csum
= NULL
;
2581 btrfs_bio
->csum_allocated
= NULL
;
2582 btrfs_bio
->end_io
= NULL
;
2588 static int __must_check
submit_one_bio(int rw
, struct bio
*bio
,
2589 int mirror_num
, unsigned long bio_flags
)
2592 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2593 struct page
*page
= bvec
->bv_page
;
2594 struct extent_io_tree
*tree
= bio
->bi_private
;
2597 start
= page_offset(page
) + bvec
->bv_offset
;
2599 bio
->bi_private
= NULL
;
2603 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
2604 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
2605 mirror_num
, bio_flags
, start
);
2607 btrfsic_submit_bio(rw
, bio
);
2609 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
2615 static int merge_bio(int rw
, struct extent_io_tree
*tree
, struct page
*page
,
2616 unsigned long offset
, size_t size
, struct bio
*bio
,
2617 unsigned long bio_flags
)
2620 if (tree
->ops
&& tree
->ops
->merge_bio_hook
)
2621 ret
= tree
->ops
->merge_bio_hook(rw
, page
, offset
, size
, bio
,
2628 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
2629 struct page
*page
, sector_t sector
,
2630 size_t size
, unsigned long offset
,
2631 struct block_device
*bdev
,
2632 struct bio
**bio_ret
,
2633 unsigned long max_pages
,
2634 bio_end_io_t end_io_func
,
2636 unsigned long prev_bio_flags
,
2637 unsigned long bio_flags
)
2643 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
2644 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2645 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
2647 if (bio_ret
&& *bio_ret
) {
2650 contig
= bio
->bi_sector
== sector
;
2652 contig
= bio_end_sector(bio
) == sector
;
2654 if (prev_bio_flags
!= bio_flags
|| !contig
||
2655 merge_bio(rw
, tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2656 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2657 ret
= submit_one_bio(rw
, bio
, mirror_num
,
2666 if (this_compressed
)
2669 nr
= bio_get_nr_vecs(bdev
);
2671 bio
= btrfs_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
2675 bio_add_page(bio
, page
, page_size
, offset
);
2676 bio
->bi_end_io
= end_io_func
;
2677 bio
->bi_private
= tree
;
2682 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
2687 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2690 if (!PagePrivate(page
)) {
2691 SetPagePrivate(page
);
2692 page_cache_get(page
);
2693 set_page_private(page
, (unsigned long)eb
);
2695 WARN_ON(page
->private != (unsigned long)eb
);
2699 void set_page_extent_mapped(struct page
*page
)
2701 if (!PagePrivate(page
)) {
2702 SetPagePrivate(page
);
2703 page_cache_get(page
);
2704 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2708 static struct extent_map
*
2709 __get_extent_map(struct inode
*inode
, struct page
*page
, size_t pg_offset
,
2710 u64 start
, u64 len
, get_extent_t
*get_extent
,
2711 struct extent_map
**em_cached
)
2713 struct extent_map
*em
;
2715 if (em_cached
&& *em_cached
) {
2717 if (em
->in_tree
&& start
>= em
->start
&&
2718 start
< extent_map_end(em
)) {
2719 atomic_inc(&em
->refs
);
2723 free_extent_map(em
);
2727 em
= get_extent(inode
, page
, pg_offset
, start
, len
, 0);
2728 if (em_cached
&& !IS_ERR_OR_NULL(em
)) {
2730 atomic_inc(&em
->refs
);
2736 * basic readpage implementation. Locked extent state structs are inserted
2737 * into the tree that are removed when the IO is done (by the end_io
2739 * XXX JDM: This needs looking at to ensure proper page locking
2741 static int __do_readpage(struct extent_io_tree
*tree
,
2743 get_extent_t
*get_extent
,
2744 struct extent_map
**em_cached
,
2745 struct bio
**bio
, int mirror_num
,
2746 unsigned long *bio_flags
, int rw
)
2748 struct inode
*inode
= page
->mapping
->host
;
2749 u64 start
= page_offset(page
);
2750 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2754 u64 last_byte
= i_size_read(inode
);
2758 struct extent_map
*em
;
2759 struct block_device
*bdev
;
2762 int parent_locked
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2763 size_t pg_offset
= 0;
2765 size_t disk_io_size
;
2766 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2767 unsigned long this_bio_flag
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2769 set_page_extent_mapped(page
);
2772 if (!PageUptodate(page
)) {
2773 if (cleancache_get_page(page
) == 0) {
2774 BUG_ON(blocksize
!= PAGE_SIZE
);
2775 unlock_extent(tree
, start
, end
);
2780 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
2782 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
2785 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
2786 userpage
= kmap_atomic(page
);
2787 memset(userpage
+ zero_offset
, 0, iosize
);
2788 flush_dcache_page(page
);
2789 kunmap_atomic(userpage
);
2792 while (cur
<= end
) {
2793 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2795 if (cur
>= last_byte
) {
2797 struct extent_state
*cached
= NULL
;
2799 iosize
= PAGE_CACHE_SIZE
- pg_offset
;
2800 userpage
= kmap_atomic(page
);
2801 memset(userpage
+ pg_offset
, 0, iosize
);
2802 flush_dcache_page(page
);
2803 kunmap_atomic(userpage
);
2804 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2807 unlock_extent_cached(tree
, cur
,
2812 em
= __get_extent_map(inode
, page
, pg_offset
, cur
,
2813 end
- cur
+ 1, get_extent
, em_cached
);
2814 if (IS_ERR_OR_NULL(em
)) {
2817 unlock_extent(tree
, cur
, end
);
2820 extent_offset
= cur
- em
->start
;
2821 BUG_ON(extent_map_end(em
) <= cur
);
2824 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2825 this_bio_flag
|= EXTENT_BIO_COMPRESSED
;
2826 extent_set_compress_type(&this_bio_flag
,
2830 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2831 cur_end
= min(extent_map_end(em
) - 1, end
);
2832 iosize
= ALIGN(iosize
, blocksize
);
2833 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2834 disk_io_size
= em
->block_len
;
2835 sector
= em
->block_start
>> 9;
2837 sector
= (em
->block_start
+ extent_offset
) >> 9;
2838 disk_io_size
= iosize
;
2841 block_start
= em
->block_start
;
2842 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2843 block_start
= EXTENT_MAP_HOLE
;
2844 free_extent_map(em
);
2847 /* we've found a hole, just zero and go on */
2848 if (block_start
== EXTENT_MAP_HOLE
) {
2850 struct extent_state
*cached
= NULL
;
2852 userpage
= kmap_atomic(page
);
2853 memset(userpage
+ pg_offset
, 0, iosize
);
2854 flush_dcache_page(page
);
2855 kunmap_atomic(userpage
);
2857 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2859 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2862 pg_offset
+= iosize
;
2865 /* the get_extent function already copied into the page */
2866 if (test_range_bit(tree
, cur
, cur_end
,
2867 EXTENT_UPTODATE
, 1, NULL
)) {
2868 check_page_uptodate(tree
, page
);
2870 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2872 pg_offset
+= iosize
;
2875 /* we have an inline extent but it didn't get marked up
2876 * to date. Error out
2878 if (block_start
== EXTENT_MAP_INLINE
) {
2881 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2883 pg_offset
+= iosize
;
2888 ret
= submit_extent_page(rw
, tree
, page
,
2889 sector
, disk_io_size
, pg_offset
,
2891 end_bio_extent_readpage
, mirror_num
,
2896 *bio_flags
= this_bio_flag
;
2900 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2903 pg_offset
+= iosize
;
2907 if (!PageError(page
))
2908 SetPageUptodate(page
);
2914 static inline void __do_contiguous_readpages(struct extent_io_tree
*tree
,
2915 struct page
*pages
[], int nr_pages
,
2917 get_extent_t
*get_extent
,
2918 struct extent_map
**em_cached
,
2919 struct bio
**bio
, int mirror_num
,
2920 unsigned long *bio_flags
, int rw
)
2922 struct inode
*inode
;
2923 struct btrfs_ordered_extent
*ordered
;
2926 inode
= pages
[0]->mapping
->host
;
2928 lock_extent(tree
, start
, end
);
2929 ordered
= btrfs_lookup_ordered_range(inode
, start
,
2933 unlock_extent(tree
, start
, end
);
2934 btrfs_start_ordered_extent(inode
, ordered
, 1);
2935 btrfs_put_ordered_extent(ordered
);
2938 for (index
= 0; index
< nr_pages
; index
++) {
2939 __do_readpage(tree
, pages
[index
], get_extent
, em_cached
, bio
,
2940 mirror_num
, bio_flags
, rw
);
2941 page_cache_release(pages
[index
]);
2945 static void __extent_readpages(struct extent_io_tree
*tree
,
2946 struct page
*pages
[],
2947 int nr_pages
, get_extent_t
*get_extent
,
2948 struct extent_map
**em_cached
,
2949 struct bio
**bio
, int mirror_num
,
2950 unsigned long *bio_flags
, int rw
)
2956 int first_index
= 0;
2958 for (index
= 0; index
< nr_pages
; index
++) {
2959 page_start
= page_offset(pages
[index
]);
2962 end
= start
+ PAGE_CACHE_SIZE
- 1;
2963 first_index
= index
;
2964 } else if (end
+ 1 == page_start
) {
2965 end
+= PAGE_CACHE_SIZE
;
2967 __do_contiguous_readpages(tree
, &pages
[first_index
],
2968 index
- first_index
, start
,
2969 end
, get_extent
, em_cached
,
2970 bio
, mirror_num
, bio_flags
,
2973 end
= start
+ PAGE_CACHE_SIZE
- 1;
2974 first_index
= index
;
2979 __do_contiguous_readpages(tree
, &pages
[first_index
],
2980 index
- first_index
, start
,
2981 end
, get_extent
, em_cached
, bio
,
2982 mirror_num
, bio_flags
, rw
);
2985 static int __extent_read_full_page(struct extent_io_tree
*tree
,
2987 get_extent_t
*get_extent
,
2988 struct bio
**bio
, int mirror_num
,
2989 unsigned long *bio_flags
, int rw
)
2991 struct inode
*inode
= page
->mapping
->host
;
2992 struct btrfs_ordered_extent
*ordered
;
2993 u64 start
= page_offset(page
);
2994 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
2998 lock_extent(tree
, start
, end
);
2999 ordered
= btrfs_lookup_ordered_extent(inode
, start
);
3002 unlock_extent(tree
, start
, end
);
3003 btrfs_start_ordered_extent(inode
, ordered
, 1);
3004 btrfs_put_ordered_extent(ordered
);
3007 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, bio
, mirror_num
,
3012 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3013 get_extent_t
*get_extent
, int mirror_num
)
3015 struct bio
*bio
= NULL
;
3016 unsigned long bio_flags
= 0;
3019 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
3022 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3026 int extent_read_full_page_nolock(struct extent_io_tree
*tree
, struct page
*page
,
3027 get_extent_t
*get_extent
, int mirror_num
)
3029 struct bio
*bio
= NULL
;
3030 unsigned long bio_flags
= EXTENT_BIO_PARENT_LOCKED
;
3033 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, &bio
, mirror_num
,
3036 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3040 static noinline
void update_nr_written(struct page
*page
,
3041 struct writeback_control
*wbc
,
3042 unsigned long nr_written
)
3044 wbc
->nr_to_write
-= nr_written
;
3045 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
3046 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
3047 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
3051 * the writepage semantics are similar to regular writepage. extent
3052 * records are inserted to lock ranges in the tree, and as dirty areas
3053 * are found, they are marked writeback. Then the lock bits are removed
3054 * and the end_io handler clears the writeback ranges
3056 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
3059 struct inode
*inode
= page
->mapping
->host
;
3060 struct extent_page_data
*epd
= data
;
3061 struct extent_io_tree
*tree
= epd
->tree
;
3062 u64 start
= page_offset(page
);
3064 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
3068 u64 last_byte
= i_size_read(inode
);
3072 struct extent_state
*cached_state
= NULL
;
3073 struct extent_map
*em
;
3074 struct block_device
*bdev
;
3077 size_t pg_offset
= 0;
3079 loff_t i_size
= i_size_read(inode
);
3080 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
3086 unsigned long nr_written
= 0;
3087 bool fill_delalloc
= true;
3089 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3090 write_flags
= WRITE_SYNC
;
3092 write_flags
= WRITE
;
3094 trace___extent_writepage(page
, inode
, wbc
);
3096 WARN_ON(!PageLocked(page
));
3098 ClearPageError(page
);
3100 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
3101 if (page
->index
> end_index
||
3102 (page
->index
== end_index
&& !pg_offset
)) {
3103 page
->mapping
->a_ops
->invalidatepage(page
, 0, PAGE_CACHE_SIZE
);
3108 if (page
->index
== end_index
) {
3111 userpage
= kmap_atomic(page
);
3112 memset(userpage
+ pg_offset
, 0,
3113 PAGE_CACHE_SIZE
- pg_offset
);
3114 kunmap_atomic(userpage
);
3115 flush_dcache_page(page
);
3119 set_page_extent_mapped(page
);
3121 if (!tree
->ops
|| !tree
->ops
->fill_delalloc
)
3122 fill_delalloc
= false;
3124 delalloc_start
= start
;
3127 if (!epd
->extent_locked
&& fill_delalloc
) {
3128 u64 delalloc_to_write
= 0;
3130 * make sure the wbc mapping index is at least updated
3133 update_nr_written(page
, wbc
, 0);
3135 while (delalloc_end
< page_end
) {
3136 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
3141 if (nr_delalloc
== 0) {
3142 delalloc_start
= delalloc_end
+ 1;
3145 ret
= tree
->ops
->fill_delalloc(inode
, page
,
3150 /* File system has been set read-only */
3156 * delalloc_end is already one less than the total
3157 * length, so we don't subtract one from
3160 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3163 delalloc_start
= delalloc_end
+ 1;
3165 if (wbc
->nr_to_write
< delalloc_to_write
) {
3168 if (delalloc_to_write
< thresh
* 2)
3169 thresh
= delalloc_to_write
;
3170 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3174 /* did the fill delalloc function already unlock and start
3180 * we've unlocked the page, so we can't update
3181 * the mapping's writeback index, just update
3184 wbc
->nr_to_write
-= nr_written
;
3188 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3189 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3192 /* Fixup worker will requeue */
3194 wbc
->pages_skipped
++;
3196 redirty_page_for_writepage(wbc
, page
);
3197 update_nr_written(page
, wbc
, nr_written
);
3205 * we don't want to touch the inode after unlocking the page,
3206 * so we update the mapping writeback index now
3208 update_nr_written(page
, wbc
, nr_written
+ 1);
3211 if (last_byte
<= start
) {
3212 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3213 tree
->ops
->writepage_end_io_hook(page
, start
,
3218 blocksize
= inode
->i_sb
->s_blocksize
;
3220 while (cur
<= end
) {
3221 if (cur
>= last_byte
) {
3222 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3223 tree
->ops
->writepage_end_io_hook(page
, cur
,
3227 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
3229 if (IS_ERR_OR_NULL(em
)) {
3234 extent_offset
= cur
- em
->start
;
3235 BUG_ON(extent_map_end(em
) <= cur
);
3237 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
3238 iosize
= ALIGN(iosize
, blocksize
);
3239 sector
= (em
->block_start
+ extent_offset
) >> 9;
3241 block_start
= em
->block_start
;
3242 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3243 free_extent_map(em
);
3247 * compressed and inline extents are written through other
3250 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3251 block_start
== EXTENT_MAP_INLINE
) {
3253 * end_io notification does not happen here for
3254 * compressed extents
3256 if (!compressed
&& tree
->ops
&&
3257 tree
->ops
->writepage_end_io_hook
)
3258 tree
->ops
->writepage_end_io_hook(page
, cur
,
3261 else if (compressed
) {
3262 /* we don't want to end_page_writeback on
3263 * a compressed extent. this happens
3270 pg_offset
+= iosize
;
3273 /* leave this out until we have a page_mkwrite call */
3274 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
3275 EXTENT_DIRTY
, 0, NULL
)) {
3277 pg_offset
+= iosize
;
3281 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
3282 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
3290 unsigned long max_nr
= end_index
+ 1;
3292 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3293 if (!PageWriteback(page
)) {
3294 printk(KERN_ERR
"btrfs warning page %lu not "
3295 "writeback, cur %llu end %llu\n",
3296 page
->index
, cur
, end
);
3299 ret
= submit_extent_page(write_flags
, tree
, page
,
3300 sector
, iosize
, pg_offset
,
3301 bdev
, &epd
->bio
, max_nr
,
3302 end_bio_extent_writepage
,
3308 pg_offset
+= iosize
;
3313 /* make sure the mapping tag for page dirty gets cleared */
3314 set_page_writeback(page
);
3315 end_page_writeback(page
);
3321 /* drop our reference on any cached states */
3322 free_extent_state(cached_state
);
3326 static int eb_wait(void *word
)
3332 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3334 wait_on_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
, eb_wait
,
3335 TASK_UNINTERRUPTIBLE
);
3338 static int lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3339 struct btrfs_fs_info
*fs_info
,
3340 struct extent_page_data
*epd
)
3342 unsigned long i
, num_pages
;
3346 if (!btrfs_try_tree_write_lock(eb
)) {
3348 flush_write_bio(epd
);
3349 btrfs_tree_lock(eb
);
3352 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3353 btrfs_tree_unlock(eb
);
3357 flush_write_bio(epd
);
3361 wait_on_extent_buffer_writeback(eb
);
3362 btrfs_tree_lock(eb
);
3363 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3365 btrfs_tree_unlock(eb
);
3370 * We need to do this to prevent races in people who check if the eb is
3371 * under IO since we can end up having no IO bits set for a short period
3374 spin_lock(&eb
->refs_lock
);
3375 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3376 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3377 spin_unlock(&eb
->refs_lock
);
3378 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3379 __percpu_counter_add(&fs_info
->dirty_metadata_bytes
,
3381 fs_info
->dirty_metadata_batch
);
3384 spin_unlock(&eb
->refs_lock
);
3387 btrfs_tree_unlock(eb
);
3392 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3393 for (i
= 0; i
< num_pages
; i
++) {
3394 struct page
*p
= extent_buffer_page(eb
, i
);
3396 if (!trylock_page(p
)) {
3398 flush_write_bio(epd
);
3408 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3410 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3411 smp_mb__after_clear_bit();
3412 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3415 static void end_bio_extent_buffer_writepage(struct bio
*bio
, int err
)
3417 int uptodate
= err
== 0;
3418 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
3419 struct extent_buffer
*eb
;
3423 struct page
*page
= bvec
->bv_page
;
3426 eb
= (struct extent_buffer
*)page
->private;
3428 done
= atomic_dec_and_test(&eb
->io_pages
);
3430 if (!uptodate
|| test_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
)) {
3431 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3432 ClearPageUptodate(page
);
3436 end_page_writeback(page
);
3441 end_extent_buffer_writeback(eb
);
3442 } while (bvec
>= bio
->bi_io_vec
);
3448 static int write_one_eb(struct extent_buffer
*eb
,
3449 struct btrfs_fs_info
*fs_info
,
3450 struct writeback_control
*wbc
,
3451 struct extent_page_data
*epd
)
3453 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3454 u64 offset
= eb
->start
;
3455 unsigned long i
, num_pages
;
3456 unsigned long bio_flags
= 0;
3457 int rw
= (epd
->sync_io
? WRITE_SYNC
: WRITE
) | REQ_META
;
3460 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3461 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3462 atomic_set(&eb
->io_pages
, num_pages
);
3463 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3464 bio_flags
= EXTENT_BIO_TREE_LOG
;
3466 for (i
= 0; i
< num_pages
; i
++) {
3467 struct page
*p
= extent_buffer_page(eb
, i
);
3469 clear_page_dirty_for_io(p
);
3470 set_page_writeback(p
);
3471 ret
= submit_extent_page(rw
, eb
->tree
, p
, offset
>> 9,
3472 PAGE_CACHE_SIZE
, 0, bdev
, &epd
->bio
,
3473 -1, end_bio_extent_buffer_writepage
,
3474 0, epd
->bio_flags
, bio_flags
);
3475 epd
->bio_flags
= bio_flags
;
3477 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3479 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3480 end_extent_buffer_writeback(eb
);
3484 offset
+= PAGE_CACHE_SIZE
;
3485 update_nr_written(p
, wbc
, 1);
3489 if (unlikely(ret
)) {
3490 for (; i
< num_pages
; i
++) {
3491 struct page
*p
= extent_buffer_page(eb
, i
);
3499 int btree_write_cache_pages(struct address_space
*mapping
,
3500 struct writeback_control
*wbc
)
3502 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3503 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3504 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3505 struct extent_page_data epd
= {
3509 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3514 int nr_to_write_done
= 0;
3515 struct pagevec pvec
;
3518 pgoff_t end
; /* Inclusive */
3522 pagevec_init(&pvec
, 0);
3523 if (wbc
->range_cyclic
) {
3524 index
= mapping
->writeback_index
; /* Start from prev offset */
3527 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3528 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3531 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3532 tag
= PAGECACHE_TAG_TOWRITE
;
3534 tag
= PAGECACHE_TAG_DIRTY
;
3536 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3537 tag_pages_for_writeback(mapping
, index
, end
);
3538 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3539 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3540 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3544 for (i
= 0; i
< nr_pages
; i
++) {
3545 struct page
*page
= pvec
.pages
[i
];
3547 if (!PagePrivate(page
))
3550 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3555 spin_lock(&mapping
->private_lock
);
3556 if (!PagePrivate(page
)) {
3557 spin_unlock(&mapping
->private_lock
);
3561 eb
= (struct extent_buffer
*)page
->private;
3564 * Shouldn't happen and normally this would be a BUG_ON
3565 * but no sense in crashing the users box for something
3566 * we can survive anyway.
3569 spin_unlock(&mapping
->private_lock
);
3574 if (eb
== prev_eb
) {
3575 spin_unlock(&mapping
->private_lock
);
3579 ret
= atomic_inc_not_zero(&eb
->refs
);
3580 spin_unlock(&mapping
->private_lock
);
3585 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3587 free_extent_buffer(eb
);
3591 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3594 free_extent_buffer(eb
);
3597 free_extent_buffer(eb
);
3600 * the filesystem may choose to bump up nr_to_write.
3601 * We have to make sure to honor the new nr_to_write
3604 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3606 pagevec_release(&pvec
);
3609 if (!scanned
&& !done
) {
3611 * We hit the last page and there is more work to be done: wrap
3612 * back to the start of the file
3618 flush_write_bio(&epd
);
3623 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3624 * @mapping: address space structure to write
3625 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3626 * @writepage: function called for each page
3627 * @data: data passed to writepage function
3629 * If a page is already under I/O, write_cache_pages() skips it, even
3630 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3631 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3632 * and msync() need to guarantee that all the data which was dirty at the time
3633 * the call was made get new I/O started against them. If wbc->sync_mode is
3634 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3635 * existing IO to complete.
3637 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
3638 struct address_space
*mapping
,
3639 struct writeback_control
*wbc
,
3640 writepage_t writepage
, void *data
,
3641 void (*flush_fn
)(void *))
3643 struct inode
*inode
= mapping
->host
;
3646 int nr_to_write_done
= 0;
3647 struct pagevec pvec
;
3650 pgoff_t end
; /* Inclusive */
3655 * We have to hold onto the inode so that ordered extents can do their
3656 * work when the IO finishes. The alternative to this is failing to add
3657 * an ordered extent if the igrab() fails there and that is a huge pain
3658 * to deal with, so instead just hold onto the inode throughout the
3659 * writepages operation. If it fails here we are freeing up the inode
3660 * anyway and we'd rather not waste our time writing out stuff that is
3661 * going to be truncated anyway.
3666 pagevec_init(&pvec
, 0);
3667 if (wbc
->range_cyclic
) {
3668 index
= mapping
->writeback_index
; /* Start from prev offset */
3671 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3672 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3675 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3676 tag
= PAGECACHE_TAG_TOWRITE
;
3678 tag
= PAGECACHE_TAG_DIRTY
;
3680 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3681 tag_pages_for_writeback(mapping
, index
, end
);
3682 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3683 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3684 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3688 for (i
= 0; i
< nr_pages
; i
++) {
3689 struct page
*page
= pvec
.pages
[i
];
3692 * At this point we hold neither mapping->tree_lock nor
3693 * lock on the page itself: the page may be truncated or
3694 * invalidated (changing page->mapping to NULL), or even
3695 * swizzled back from swapper_space to tmpfs file
3698 if (!trylock_page(page
)) {
3703 if (unlikely(page
->mapping
!= mapping
)) {
3708 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3714 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
3715 if (PageWriteback(page
))
3717 wait_on_page_writeback(page
);
3720 if (PageWriteback(page
) ||
3721 !clear_page_dirty_for_io(page
)) {
3726 ret
= (*writepage
)(page
, wbc
, data
);
3728 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
3736 * the filesystem may choose to bump up nr_to_write.
3737 * We have to make sure to honor the new nr_to_write
3740 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3742 pagevec_release(&pvec
);
3745 if (!scanned
&& !done
) {
3747 * We hit the last page and there is more work to be done: wrap
3748 * back to the start of the file
3754 btrfs_add_delayed_iput(inode
);
3758 static void flush_epd_write_bio(struct extent_page_data
*epd
)
3767 ret
= submit_one_bio(rw
, epd
->bio
, 0, epd
->bio_flags
);
3768 BUG_ON(ret
< 0); /* -ENOMEM */
3773 static noinline
void flush_write_bio(void *data
)
3775 struct extent_page_data
*epd
= data
;
3776 flush_epd_write_bio(epd
);
3779 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3780 get_extent_t
*get_extent
,
3781 struct writeback_control
*wbc
)
3784 struct extent_page_data epd
= {
3787 .get_extent
= get_extent
,
3789 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3793 ret
= __extent_writepage(page
, wbc
, &epd
);
3795 flush_epd_write_bio(&epd
);
3799 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
3800 u64 start
, u64 end
, get_extent_t
*get_extent
,
3804 struct address_space
*mapping
= inode
->i_mapping
;
3806 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
3809 struct extent_page_data epd
= {
3812 .get_extent
= get_extent
,
3814 .sync_io
= mode
== WB_SYNC_ALL
,
3817 struct writeback_control wbc_writepages
= {
3819 .nr_to_write
= nr_pages
* 2,
3820 .range_start
= start
,
3821 .range_end
= end
+ 1,
3824 while (start
<= end
) {
3825 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
3826 if (clear_page_dirty_for_io(page
))
3827 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
3829 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3830 tree
->ops
->writepage_end_io_hook(page
, start
,
3831 start
+ PAGE_CACHE_SIZE
- 1,
3835 page_cache_release(page
);
3836 start
+= PAGE_CACHE_SIZE
;
3839 flush_epd_write_bio(&epd
);
3843 int extent_writepages(struct extent_io_tree
*tree
,
3844 struct address_space
*mapping
,
3845 get_extent_t
*get_extent
,
3846 struct writeback_control
*wbc
)
3849 struct extent_page_data epd
= {
3852 .get_extent
= get_extent
,
3854 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3858 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
3859 __extent_writepage
, &epd
,
3861 flush_epd_write_bio(&epd
);
3865 int extent_readpages(struct extent_io_tree
*tree
,
3866 struct address_space
*mapping
,
3867 struct list_head
*pages
, unsigned nr_pages
,
3868 get_extent_t get_extent
)
3870 struct bio
*bio
= NULL
;
3872 unsigned long bio_flags
= 0;
3873 struct page
*pagepool
[16];
3875 struct extent_map
*em_cached
= NULL
;
3878 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
3879 page
= list_entry(pages
->prev
, struct page
, lru
);
3881 prefetchw(&page
->flags
);
3882 list_del(&page
->lru
);
3883 if (add_to_page_cache_lru(page
, mapping
,
3884 page
->index
, GFP_NOFS
)) {
3885 page_cache_release(page
);
3889 pagepool
[nr
++] = page
;
3890 if (nr
< ARRAY_SIZE(pagepool
))
3892 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
3893 &bio
, 0, &bio_flags
, READ
);
3897 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
3898 &bio
, 0, &bio_flags
, READ
);
3901 free_extent_map(em_cached
);
3903 BUG_ON(!list_empty(pages
));
3905 return submit_one_bio(READ
, bio
, 0, bio_flags
);
3910 * basic invalidatepage code, this waits on any locked or writeback
3911 * ranges corresponding to the page, and then deletes any extent state
3912 * records from the tree
3914 int extent_invalidatepage(struct extent_io_tree
*tree
,
3915 struct page
*page
, unsigned long offset
)
3917 struct extent_state
*cached_state
= NULL
;
3918 u64 start
= page_offset(page
);
3919 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3920 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
3922 start
+= ALIGN(offset
, blocksize
);
3926 lock_extent_bits(tree
, start
, end
, 0, &cached_state
);
3927 wait_on_page_writeback(page
);
3928 clear_extent_bit(tree
, start
, end
,
3929 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
3930 EXTENT_DO_ACCOUNTING
,
3931 1, 1, &cached_state
, GFP_NOFS
);
3936 * a helper for releasepage, this tests for areas of the page that
3937 * are locked or under IO and drops the related state bits if it is safe
3940 static int try_release_extent_state(struct extent_map_tree
*map
,
3941 struct extent_io_tree
*tree
,
3942 struct page
*page
, gfp_t mask
)
3944 u64 start
= page_offset(page
);
3945 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3948 if (test_range_bit(tree
, start
, end
,
3949 EXTENT_IOBITS
, 0, NULL
))
3952 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
3955 * at this point we can safely clear everything except the
3956 * locked bit and the nodatasum bit
3958 ret
= clear_extent_bit(tree
, start
, end
,
3959 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
3962 /* if clear_extent_bit failed for enomem reasons,
3963 * we can't allow the release to continue.
3974 * a helper for releasepage. As long as there are no locked extents
3975 * in the range corresponding to the page, both state records and extent
3976 * map records are removed
3978 int try_release_extent_mapping(struct extent_map_tree
*map
,
3979 struct extent_io_tree
*tree
, struct page
*page
,
3982 struct extent_map
*em
;
3983 u64 start
= page_offset(page
);
3984 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3986 if ((mask
& __GFP_WAIT
) &&
3987 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
3989 while (start
<= end
) {
3990 len
= end
- start
+ 1;
3991 write_lock(&map
->lock
);
3992 em
= lookup_extent_mapping(map
, start
, len
);
3994 write_unlock(&map
->lock
);
3997 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
3998 em
->start
!= start
) {
3999 write_unlock(&map
->lock
);
4000 free_extent_map(em
);
4003 if (!test_range_bit(tree
, em
->start
,
4004 extent_map_end(em
) - 1,
4005 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
4007 remove_extent_mapping(map
, em
);
4008 /* once for the rb tree */
4009 free_extent_map(em
);
4011 start
= extent_map_end(em
);
4012 write_unlock(&map
->lock
);
4015 free_extent_map(em
);
4018 return try_release_extent_state(map
, tree
, page
, mask
);
4022 * helper function for fiemap, which doesn't want to see any holes.
4023 * This maps until we find something past 'last'
4025 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
4028 get_extent_t
*get_extent
)
4030 u64 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
4031 struct extent_map
*em
;
4038 len
= last
- offset
;
4041 len
= ALIGN(len
, sectorsize
);
4042 em
= get_extent(inode
, NULL
, 0, offset
, len
, 0);
4043 if (IS_ERR_OR_NULL(em
))
4046 /* if this isn't a hole return it */
4047 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
4048 em
->block_start
!= EXTENT_MAP_HOLE
) {
4052 /* this is a hole, advance to the next extent */
4053 offset
= extent_map_end(em
);
4054 free_extent_map(em
);
4061 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4062 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
4066 u64 max
= start
+ len
;
4070 u64 last_for_get_extent
= 0;
4072 u64 isize
= i_size_read(inode
);
4073 struct btrfs_key found_key
;
4074 struct extent_map
*em
= NULL
;
4075 struct extent_state
*cached_state
= NULL
;
4076 struct btrfs_path
*path
;
4077 struct btrfs_file_extent_item
*item
;
4082 unsigned long emflags
;
4087 path
= btrfs_alloc_path();
4090 path
->leave_spinning
= 1;
4092 start
= ALIGN(start
, BTRFS_I(inode
)->root
->sectorsize
);
4093 len
= ALIGN(len
, BTRFS_I(inode
)->root
->sectorsize
);
4096 * lookup the last file extent. We're not using i_size here
4097 * because there might be preallocation past i_size
4099 ret
= btrfs_lookup_file_extent(NULL
, BTRFS_I(inode
)->root
,
4100 path
, btrfs_ino(inode
), -1, 0);
4102 btrfs_free_path(path
);
4107 item
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
4108 struct btrfs_file_extent_item
);
4109 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
4110 found_type
= btrfs_key_type(&found_key
);
4112 /* No extents, but there might be delalloc bits */
4113 if (found_key
.objectid
!= btrfs_ino(inode
) ||
4114 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
4115 /* have to trust i_size as the end */
4117 last_for_get_extent
= isize
;
4120 * remember the start of the last extent. There are a
4121 * bunch of different factors that go into the length of the
4122 * extent, so its much less complex to remember where it started
4124 last
= found_key
.offset
;
4125 last_for_get_extent
= last
+ 1;
4127 btrfs_free_path(path
);
4130 * we might have some extents allocated but more delalloc past those
4131 * extents. so, we trust isize unless the start of the last extent is
4136 last_for_get_extent
= isize
;
4139 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1, 0,
4142 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4152 u64 offset_in_extent
= 0;
4154 /* break if the extent we found is outside the range */
4155 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4159 * get_extent may return an extent that starts before our
4160 * requested range. We have to make sure the ranges
4161 * we return to fiemap always move forward and don't
4162 * overlap, so adjust the offsets here
4164 em_start
= max(em
->start
, off
);
4167 * record the offset from the start of the extent
4168 * for adjusting the disk offset below. Only do this if the
4169 * extent isn't compressed since our in ram offset may be past
4170 * what we have actually allocated on disk.
4172 if (!test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4173 offset_in_extent
= em_start
- em
->start
;
4174 em_end
= extent_map_end(em
);
4175 em_len
= em_end
- em_start
;
4176 emflags
= em
->flags
;
4181 * bump off for our next call to get_extent
4183 off
= extent_map_end(em
);
4187 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4189 flags
|= FIEMAP_EXTENT_LAST
;
4190 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4191 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4192 FIEMAP_EXTENT_NOT_ALIGNED
);
4193 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4194 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4195 FIEMAP_EXTENT_UNKNOWN
);
4197 disko
= em
->block_start
+ offset_in_extent
;
4199 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4200 flags
|= FIEMAP_EXTENT_ENCODED
;
4202 free_extent_map(em
);
4204 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4205 (last
== (u64
)-1 && isize
<= em_end
)) {
4206 flags
|= FIEMAP_EXTENT_LAST
;
4210 /* now scan forward to see if this is really the last extent. */
4211 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4218 flags
|= FIEMAP_EXTENT_LAST
;
4221 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
4227 free_extent_map(em
);
4229 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4230 &cached_state
, GFP_NOFS
);
4234 static void __free_extent_buffer(struct extent_buffer
*eb
)
4236 btrfs_leak_debug_del(&eb
->leak_list
);
4237 kmem_cache_free(extent_buffer_cache
, eb
);
4240 static int extent_buffer_under_io(struct extent_buffer
*eb
)
4242 return (atomic_read(&eb
->io_pages
) ||
4243 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4244 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4248 * Helper for releasing extent buffer page.
4250 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
,
4251 unsigned long start_idx
)
4253 unsigned long index
;
4254 unsigned long num_pages
;
4256 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4258 BUG_ON(extent_buffer_under_io(eb
));
4260 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4261 index
= start_idx
+ num_pages
;
4262 if (start_idx
>= index
)
4267 page
= extent_buffer_page(eb
, index
);
4268 if (page
&& mapped
) {
4269 spin_lock(&page
->mapping
->private_lock
);
4271 * We do this since we'll remove the pages after we've
4272 * removed the eb from the radix tree, so we could race
4273 * and have this page now attached to the new eb. So
4274 * only clear page_private if it's still connected to
4277 if (PagePrivate(page
) &&
4278 page
->private == (unsigned long)eb
) {
4279 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4280 BUG_ON(PageDirty(page
));
4281 BUG_ON(PageWriteback(page
));
4283 * We need to make sure we haven't be attached
4286 ClearPagePrivate(page
);
4287 set_page_private(page
, 0);
4288 /* One for the page private */
4289 page_cache_release(page
);
4291 spin_unlock(&page
->mapping
->private_lock
);
4295 /* One for when we alloced the page */
4296 page_cache_release(page
);
4298 } while (index
!= start_idx
);
4302 * Helper for releasing the extent buffer.
4304 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4306 btrfs_release_extent_buffer_page(eb
, 0);
4307 __free_extent_buffer(eb
);
4310 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
4315 struct extent_buffer
*eb
= NULL
;
4317 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
4324 rwlock_init(&eb
->lock
);
4325 atomic_set(&eb
->write_locks
, 0);
4326 atomic_set(&eb
->read_locks
, 0);
4327 atomic_set(&eb
->blocking_readers
, 0);
4328 atomic_set(&eb
->blocking_writers
, 0);
4329 atomic_set(&eb
->spinning_readers
, 0);
4330 atomic_set(&eb
->spinning_writers
, 0);
4331 eb
->lock_nested
= 0;
4332 init_waitqueue_head(&eb
->write_lock_wq
);
4333 init_waitqueue_head(&eb
->read_lock_wq
);
4335 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4337 spin_lock_init(&eb
->refs_lock
);
4338 atomic_set(&eb
->refs
, 1);
4339 atomic_set(&eb
->io_pages
, 0);
4342 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4344 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4345 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4346 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4351 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4355 struct extent_buffer
*new;
4356 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4358 new = __alloc_extent_buffer(NULL
, src
->start
, src
->len
, GFP_NOFS
);
4362 for (i
= 0; i
< num_pages
; i
++) {
4363 p
= alloc_page(GFP_NOFS
);
4365 btrfs_release_extent_buffer(new);
4368 attach_extent_buffer_page(new, p
);
4369 WARN_ON(PageDirty(p
));
4374 copy_extent_buffer(new, src
, 0, 0, src
->len
);
4375 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4376 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4381 struct extent_buffer
*alloc_dummy_extent_buffer(u64 start
, unsigned long len
)
4383 struct extent_buffer
*eb
;
4384 unsigned long num_pages
= num_extent_pages(0, len
);
4387 eb
= __alloc_extent_buffer(NULL
, start
, len
, GFP_NOFS
);
4391 for (i
= 0; i
< num_pages
; i
++) {
4392 eb
->pages
[i
] = alloc_page(GFP_NOFS
);
4396 set_extent_buffer_uptodate(eb
);
4397 btrfs_set_header_nritems(eb
, 0);
4398 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4403 __free_page(eb
->pages
[i
- 1]);
4404 __free_extent_buffer(eb
);
4408 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4411 /* the ref bit is tricky. We have to make sure it is set
4412 * if we have the buffer dirty. Otherwise the
4413 * code to free a buffer can end up dropping a dirty
4416 * Once the ref bit is set, it won't go away while the
4417 * buffer is dirty or in writeback, and it also won't
4418 * go away while we have the reference count on the
4421 * We can't just set the ref bit without bumping the
4422 * ref on the eb because free_extent_buffer might
4423 * see the ref bit and try to clear it. If this happens
4424 * free_extent_buffer might end up dropping our original
4425 * ref by mistake and freeing the page before we are able
4426 * to add one more ref.
4428 * So bump the ref count first, then set the bit. If someone
4429 * beat us to it, drop the ref we added.
4431 refs
= atomic_read(&eb
->refs
);
4432 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4435 spin_lock(&eb
->refs_lock
);
4436 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4437 atomic_inc(&eb
->refs
);
4438 spin_unlock(&eb
->refs_lock
);
4441 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
)
4443 unsigned long num_pages
, i
;
4445 check_buffer_tree_ref(eb
);
4447 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4448 for (i
= 0; i
< num_pages
; i
++) {
4449 struct page
*p
= extent_buffer_page(eb
, i
);
4450 mark_page_accessed(p
);
4454 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
4455 u64 start
, unsigned long len
)
4457 unsigned long num_pages
= num_extent_pages(start
, len
);
4459 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
4460 struct extent_buffer
*eb
;
4461 struct extent_buffer
*exists
= NULL
;
4463 struct address_space
*mapping
= tree
->mapping
;
4468 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4469 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4471 mark_extent_buffer_accessed(eb
);
4476 eb
= __alloc_extent_buffer(tree
, start
, len
, GFP_NOFS
);
4480 for (i
= 0; i
< num_pages
; i
++, index
++) {
4481 p
= find_or_create_page(mapping
, index
, GFP_NOFS
);
4485 spin_lock(&mapping
->private_lock
);
4486 if (PagePrivate(p
)) {
4488 * We could have already allocated an eb for this page
4489 * and attached one so lets see if we can get a ref on
4490 * the existing eb, and if we can we know it's good and
4491 * we can just return that one, else we know we can just
4492 * overwrite page->private.
4494 exists
= (struct extent_buffer
*)p
->private;
4495 if (atomic_inc_not_zero(&exists
->refs
)) {
4496 spin_unlock(&mapping
->private_lock
);
4498 page_cache_release(p
);
4499 mark_extent_buffer_accessed(exists
);
4504 * Do this so attach doesn't complain and we need to
4505 * drop the ref the old guy had.
4507 ClearPagePrivate(p
);
4508 WARN_ON(PageDirty(p
));
4509 page_cache_release(p
);
4511 attach_extent_buffer_page(eb
, p
);
4512 spin_unlock(&mapping
->private_lock
);
4513 WARN_ON(PageDirty(p
));
4514 mark_page_accessed(p
);
4516 if (!PageUptodate(p
))
4520 * see below about how we avoid a nasty race with release page
4521 * and why we unlock later
4525 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4527 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
4531 spin_lock(&tree
->buffer_lock
);
4532 ret
= radix_tree_insert(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
, eb
);
4533 if (ret
== -EEXIST
) {
4534 exists
= radix_tree_lookup(&tree
->buffer
,
4535 start
>> PAGE_CACHE_SHIFT
);
4536 if (!atomic_inc_not_zero(&exists
->refs
)) {
4537 spin_unlock(&tree
->buffer_lock
);
4538 radix_tree_preload_end();
4542 spin_unlock(&tree
->buffer_lock
);
4543 radix_tree_preload_end();
4544 mark_extent_buffer_accessed(exists
);
4547 /* add one reference for the tree */
4548 check_buffer_tree_ref(eb
);
4549 spin_unlock(&tree
->buffer_lock
);
4550 radix_tree_preload_end();
4553 * there is a race where release page may have
4554 * tried to find this extent buffer in the radix
4555 * but failed. It will tell the VM it is safe to
4556 * reclaim the, and it will clear the page private bit.
4557 * We must make sure to set the page private bit properly
4558 * after the extent buffer is in the radix tree so
4559 * it doesn't get lost
4561 SetPageChecked(eb
->pages
[0]);
4562 for (i
= 1; i
< num_pages
; i
++) {
4563 p
= extent_buffer_page(eb
, i
);
4564 ClearPageChecked(p
);
4567 unlock_page(eb
->pages
[0]);
4571 for (i
= 0; i
< num_pages
; i
++) {
4573 unlock_page(eb
->pages
[i
]);
4576 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
4577 btrfs_release_extent_buffer(eb
);
4581 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
4582 u64 start
, unsigned long len
)
4584 struct extent_buffer
*eb
;
4587 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4588 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4590 mark_extent_buffer_accessed(eb
);
4598 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
4600 struct extent_buffer
*eb
=
4601 container_of(head
, struct extent_buffer
, rcu_head
);
4603 __free_extent_buffer(eb
);
4606 /* Expects to have eb->eb_lock already held */
4607 static int release_extent_buffer(struct extent_buffer
*eb
)
4609 WARN_ON(atomic_read(&eb
->refs
) == 0);
4610 if (atomic_dec_and_test(&eb
->refs
)) {
4611 if (test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
)) {
4612 spin_unlock(&eb
->refs_lock
);
4614 struct extent_io_tree
*tree
= eb
->tree
;
4616 spin_unlock(&eb
->refs_lock
);
4618 spin_lock(&tree
->buffer_lock
);
4619 radix_tree_delete(&tree
->buffer
,
4620 eb
->start
>> PAGE_CACHE_SHIFT
);
4621 spin_unlock(&tree
->buffer_lock
);
4624 /* Should be safe to release our pages at this point */
4625 btrfs_release_extent_buffer_page(eb
, 0);
4626 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
4629 spin_unlock(&eb
->refs_lock
);
4634 void free_extent_buffer(struct extent_buffer
*eb
)
4642 refs
= atomic_read(&eb
->refs
);
4645 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
4650 spin_lock(&eb
->refs_lock
);
4651 if (atomic_read(&eb
->refs
) == 2 &&
4652 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
4653 atomic_dec(&eb
->refs
);
4655 if (atomic_read(&eb
->refs
) == 2 &&
4656 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
4657 !extent_buffer_under_io(eb
) &&
4658 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4659 atomic_dec(&eb
->refs
);
4662 * I know this is terrible, but it's temporary until we stop tracking
4663 * the uptodate bits and such for the extent buffers.
4665 release_extent_buffer(eb
);
4668 void free_extent_buffer_stale(struct extent_buffer
*eb
)
4673 spin_lock(&eb
->refs_lock
);
4674 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
4676 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
4677 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4678 atomic_dec(&eb
->refs
);
4679 release_extent_buffer(eb
);
4682 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
4685 unsigned long num_pages
;
4688 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4690 for (i
= 0; i
< num_pages
; i
++) {
4691 page
= extent_buffer_page(eb
, i
);
4692 if (!PageDirty(page
))
4696 WARN_ON(!PagePrivate(page
));
4698 clear_page_dirty_for_io(page
);
4699 spin_lock_irq(&page
->mapping
->tree_lock
);
4700 if (!PageDirty(page
)) {
4701 radix_tree_tag_clear(&page
->mapping
->page_tree
,
4703 PAGECACHE_TAG_DIRTY
);
4705 spin_unlock_irq(&page
->mapping
->tree_lock
);
4706 ClearPageError(page
);
4709 WARN_ON(atomic_read(&eb
->refs
) == 0);
4712 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
4715 unsigned long num_pages
;
4718 check_buffer_tree_ref(eb
);
4720 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
4722 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4723 WARN_ON(atomic_read(&eb
->refs
) == 0);
4724 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
4726 for (i
= 0; i
< num_pages
; i
++)
4727 set_page_dirty(extent_buffer_page(eb
, i
));
4731 int clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
4735 unsigned long num_pages
;
4737 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4738 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4739 for (i
= 0; i
< num_pages
; i
++) {
4740 page
= extent_buffer_page(eb
, i
);
4742 ClearPageUptodate(page
);
4747 int set_extent_buffer_uptodate(struct extent_buffer
*eb
)
4751 unsigned long num_pages
;
4753 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4754 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4755 for (i
= 0; i
< num_pages
; i
++) {
4756 page
= extent_buffer_page(eb
, i
);
4757 SetPageUptodate(page
);
4762 int extent_buffer_uptodate(struct extent_buffer
*eb
)
4764 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4767 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
4768 struct extent_buffer
*eb
, u64 start
, int wait
,
4769 get_extent_t
*get_extent
, int mirror_num
)
4772 unsigned long start_i
;
4776 int locked_pages
= 0;
4777 int all_uptodate
= 1;
4778 unsigned long num_pages
;
4779 unsigned long num_reads
= 0;
4780 struct bio
*bio
= NULL
;
4781 unsigned long bio_flags
= 0;
4783 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
4787 WARN_ON(start
< eb
->start
);
4788 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
4789 (eb
->start
>> PAGE_CACHE_SHIFT
);
4794 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4795 for (i
= start_i
; i
< num_pages
; i
++) {
4796 page
= extent_buffer_page(eb
, i
);
4797 if (wait
== WAIT_NONE
) {
4798 if (!trylock_page(page
))
4804 if (!PageUptodate(page
)) {
4811 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4815 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
4816 eb
->read_mirror
= 0;
4817 atomic_set(&eb
->io_pages
, num_reads
);
4818 for (i
= start_i
; i
< num_pages
; i
++) {
4819 page
= extent_buffer_page(eb
, i
);
4820 if (!PageUptodate(page
)) {
4821 ClearPageError(page
);
4822 err
= __extent_read_full_page(tree
, page
,
4824 mirror_num
, &bio_flags
,
4834 err
= submit_one_bio(READ
| REQ_META
, bio
, mirror_num
,
4840 if (ret
|| wait
!= WAIT_COMPLETE
)
4843 for (i
= start_i
; i
< num_pages
; i
++) {
4844 page
= extent_buffer_page(eb
, i
);
4845 wait_on_page_locked(page
);
4846 if (!PageUptodate(page
))
4854 while (locked_pages
> 0) {
4855 page
= extent_buffer_page(eb
, i
);
4863 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
4864 unsigned long start
,
4871 char *dst
= (char *)dstv
;
4872 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4873 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4875 WARN_ON(start
> eb
->len
);
4876 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4878 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4881 page
= extent_buffer_page(eb
, i
);
4883 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4884 kaddr
= page_address(page
);
4885 memcpy(dst
, kaddr
+ offset
, cur
);
4894 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
4895 unsigned long min_len
, char **map
,
4896 unsigned long *map_start
,
4897 unsigned long *map_len
)
4899 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
4902 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4903 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4904 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
4911 offset
= start_offset
;
4915 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
4918 if (start
+ min_len
> eb
->len
) {
4919 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
4921 eb
->start
, eb
->len
, start
, min_len
);
4925 p
= extent_buffer_page(eb
, i
);
4926 kaddr
= page_address(p
);
4927 *map
= kaddr
+ offset
;
4928 *map_len
= PAGE_CACHE_SIZE
- offset
;
4932 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
4933 unsigned long start
,
4940 char *ptr
= (char *)ptrv
;
4941 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4942 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4945 WARN_ON(start
> eb
->len
);
4946 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4948 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4951 page
= extent_buffer_page(eb
, i
);
4953 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4955 kaddr
= page_address(page
);
4956 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
4968 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
4969 unsigned long start
, unsigned long len
)
4975 char *src
= (char *)srcv
;
4976 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4977 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4979 WARN_ON(start
> eb
->len
);
4980 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4982 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
4985 page
= extent_buffer_page(eb
, i
);
4986 WARN_ON(!PageUptodate(page
));
4988 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
4989 kaddr
= page_address(page
);
4990 memcpy(kaddr
+ offset
, src
, cur
);
4999 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
5000 unsigned long start
, unsigned long len
)
5006 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5007 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5009 WARN_ON(start
> eb
->len
);
5010 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5012 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5015 page
= extent_buffer_page(eb
, i
);
5016 WARN_ON(!PageUptodate(page
));
5018 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
5019 kaddr
= page_address(page
);
5020 memset(kaddr
+ offset
, c
, cur
);
5028 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
5029 unsigned long dst_offset
, unsigned long src_offset
,
5032 u64 dst_len
= dst
->len
;
5037 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5038 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5040 WARN_ON(src
->len
!= dst_len
);
5042 offset
= (start_offset
+ dst_offset
) &
5043 (PAGE_CACHE_SIZE
- 1);
5046 page
= extent_buffer_page(dst
, i
);
5047 WARN_ON(!PageUptodate(page
));
5049 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
5051 kaddr
= page_address(page
);
5052 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
5061 static void move_pages(struct page
*dst_page
, struct page
*src_page
,
5062 unsigned long dst_off
, unsigned long src_off
,
5065 char *dst_kaddr
= page_address(dst_page
);
5066 if (dst_page
== src_page
) {
5067 memmove(dst_kaddr
+ dst_off
, dst_kaddr
+ src_off
, len
);
5069 char *src_kaddr
= page_address(src_page
);
5070 char *p
= dst_kaddr
+ dst_off
+ len
;
5071 char *s
= src_kaddr
+ src_off
+ len
;
5078 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
5080 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
5081 return distance
< len
;
5084 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
5085 unsigned long dst_off
, unsigned long src_off
,
5088 char *dst_kaddr
= page_address(dst_page
);
5090 int must_memmove
= 0;
5092 if (dst_page
!= src_page
) {
5093 src_kaddr
= page_address(src_page
);
5095 src_kaddr
= dst_kaddr
;
5096 if (areas_overlap(src_off
, dst_off
, len
))
5101 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5103 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5106 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5107 unsigned long src_offset
, unsigned long len
)
5110 size_t dst_off_in_page
;
5111 size_t src_off_in_page
;
5112 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5113 unsigned long dst_i
;
5114 unsigned long src_i
;
5116 if (src_offset
+ len
> dst
->len
) {
5117 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5118 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
5121 if (dst_offset
+ len
> dst
->len
) {
5122 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5123 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
5128 dst_off_in_page
= (start_offset
+ dst_offset
) &
5129 (PAGE_CACHE_SIZE
- 1);
5130 src_off_in_page
= (start_offset
+ src_offset
) &
5131 (PAGE_CACHE_SIZE
- 1);
5133 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5134 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
5136 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
5138 cur
= min_t(unsigned long, cur
,
5139 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
5141 copy_pages(extent_buffer_page(dst
, dst_i
),
5142 extent_buffer_page(dst
, src_i
),
5143 dst_off_in_page
, src_off_in_page
, cur
);
5151 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5152 unsigned long src_offset
, unsigned long len
)
5155 size_t dst_off_in_page
;
5156 size_t src_off_in_page
;
5157 unsigned long dst_end
= dst_offset
+ len
- 1;
5158 unsigned long src_end
= src_offset
+ len
- 1;
5159 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5160 unsigned long dst_i
;
5161 unsigned long src_i
;
5163 if (src_offset
+ len
> dst
->len
) {
5164 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5165 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
5168 if (dst_offset
+ len
> dst
->len
) {
5169 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5170 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
5173 if (dst_offset
< src_offset
) {
5174 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5178 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
5179 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
5181 dst_off_in_page
= (start_offset
+ dst_end
) &
5182 (PAGE_CACHE_SIZE
- 1);
5183 src_off_in_page
= (start_offset
+ src_end
) &
5184 (PAGE_CACHE_SIZE
- 1);
5186 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5187 cur
= min(cur
, dst_off_in_page
+ 1);
5188 move_pages(extent_buffer_page(dst
, dst_i
),
5189 extent_buffer_page(dst
, src_i
),
5190 dst_off_in_page
- cur
+ 1,
5191 src_off_in_page
- cur
+ 1, cur
);
5199 int try_release_extent_buffer(struct page
*page
)
5201 struct extent_buffer
*eb
;
5204 * We need to make sure noboody is attaching this page to an eb right
5207 spin_lock(&page
->mapping
->private_lock
);
5208 if (!PagePrivate(page
)) {
5209 spin_unlock(&page
->mapping
->private_lock
);
5213 eb
= (struct extent_buffer
*)page
->private;
5217 * This is a little awful but should be ok, we need to make sure that
5218 * the eb doesn't disappear out from under us while we're looking at
5221 spin_lock(&eb
->refs_lock
);
5222 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
5223 spin_unlock(&eb
->refs_lock
);
5224 spin_unlock(&page
->mapping
->private_lock
);
5227 spin_unlock(&page
->mapping
->private_lock
);
5230 * If tree ref isn't set then we know the ref on this eb is a real ref,
5231 * so just return, this page will likely be freed soon anyway.
5233 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
5234 spin_unlock(&eb
->refs_lock
);
5238 return release_extent_buffer(eb
);