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 (unsigned long long)state
->start
,
65 (unsigned long long)state
->end
,
66 state
->state
, state
->tree
, atomic_read(&state
->refs
));
67 list_del(&state
->leak_list
);
68 kmem_cache_free(extent_state_cache
, state
);
71 while (!list_empty(&buffers
)) {
72 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
73 printk(KERN_ERR
"btrfs buffer leak start %llu len %lu "
74 "refs %d\n", (unsigned long long)eb
->start
,
75 eb
->len
, atomic_read(&eb
->refs
));
76 list_del(&eb
->leak_list
);
77 kmem_cache_free(extent_buffer_cache
, eb
);
81 #define btrfs_leak_debug_add(new, head) do {} while (0)
82 #define btrfs_leak_debug_del(entry) do {} while (0)
83 #define btrfs_leak_debug_check() do {} while (0)
86 #define BUFFER_LRU_MAX 64
91 struct rb_node rb_node
;
94 struct extent_page_data
{
96 struct extent_io_tree
*tree
;
97 get_extent_t
*get_extent
;
98 unsigned long bio_flags
;
100 /* tells writepage not to lock the state bits for this range
101 * it still does the unlocking
103 unsigned int extent_locked
:1;
105 /* tells the submit_bio code to use a WRITE_SYNC */
106 unsigned int sync_io
:1;
109 static noinline
void flush_write_bio(void *data
);
110 static inline struct btrfs_fs_info
*
111 tree_fs_info(struct extent_io_tree
*tree
)
113 return btrfs_sb(tree
->mapping
->host
->i_sb
);
116 int __init
extent_io_init(void)
118 extent_state_cache
= kmem_cache_create("btrfs_extent_state",
119 sizeof(struct extent_state
), 0,
120 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
121 if (!extent_state_cache
)
124 extent_buffer_cache
= kmem_cache_create("btrfs_extent_buffer",
125 sizeof(struct extent_buffer
), 0,
126 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
127 if (!extent_buffer_cache
)
128 goto free_state_cache
;
130 btrfs_bioset
= bioset_create(BIO_POOL_SIZE
,
131 offsetof(struct btrfs_io_bio
, bio
));
133 goto free_buffer_cache
;
137 kmem_cache_destroy(extent_buffer_cache
);
138 extent_buffer_cache
= NULL
;
141 kmem_cache_destroy(extent_state_cache
);
142 extent_state_cache
= NULL
;
146 void extent_io_exit(void)
148 btrfs_leak_debug_check();
151 * Make sure all delayed rcu free are flushed before we
155 if (extent_state_cache
)
156 kmem_cache_destroy(extent_state_cache
);
157 if (extent_buffer_cache
)
158 kmem_cache_destroy(extent_buffer_cache
);
160 bioset_free(btrfs_bioset
);
163 void extent_io_tree_init(struct extent_io_tree
*tree
,
164 struct address_space
*mapping
)
166 tree
->state
= RB_ROOT
;
167 INIT_RADIX_TREE(&tree
->buffer
, GFP_ATOMIC
);
169 tree
->dirty_bytes
= 0;
170 spin_lock_init(&tree
->lock
);
171 spin_lock_init(&tree
->buffer_lock
);
172 tree
->mapping
= mapping
;
175 static struct extent_state
*alloc_extent_state(gfp_t mask
)
177 struct extent_state
*state
;
179 state
= kmem_cache_alloc(extent_state_cache
, mask
);
185 btrfs_leak_debug_add(&state
->leak_list
, &states
);
186 atomic_set(&state
->refs
, 1);
187 init_waitqueue_head(&state
->wq
);
188 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
192 void free_extent_state(struct extent_state
*state
)
196 if (atomic_dec_and_test(&state
->refs
)) {
197 WARN_ON(state
->tree
);
198 btrfs_leak_debug_del(&state
->leak_list
);
199 trace_free_extent_state(state
, _RET_IP_
);
200 kmem_cache_free(extent_state_cache
, state
);
204 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
205 struct rb_node
*node
)
207 struct rb_node
**p
= &root
->rb_node
;
208 struct rb_node
*parent
= NULL
;
209 struct tree_entry
*entry
;
213 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
215 if (offset
< entry
->start
)
217 else if (offset
> entry
->end
)
223 rb_link_node(node
, parent
, p
);
224 rb_insert_color(node
, root
);
228 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
229 struct rb_node
**prev_ret
,
230 struct rb_node
**next_ret
)
232 struct rb_root
*root
= &tree
->state
;
233 struct rb_node
*n
= root
->rb_node
;
234 struct rb_node
*prev
= NULL
;
235 struct rb_node
*orig_prev
= NULL
;
236 struct tree_entry
*entry
;
237 struct tree_entry
*prev_entry
= NULL
;
240 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
244 if (offset
< entry
->start
)
246 else if (offset
> entry
->end
)
254 while (prev
&& offset
> prev_entry
->end
) {
255 prev
= rb_next(prev
);
256 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
263 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
264 while (prev
&& offset
< prev_entry
->start
) {
265 prev
= rb_prev(prev
);
266 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
273 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
276 struct rb_node
*prev
= NULL
;
279 ret
= __etree_search(tree
, offset
, &prev
, NULL
);
285 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
286 struct extent_state
*other
)
288 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
289 tree
->ops
->merge_extent_hook(tree
->mapping
->host
, new,
294 * utility function to look for merge candidates inside a given range.
295 * Any extents with matching state are merged together into a single
296 * extent in the tree. Extents with EXTENT_IO in their state field
297 * are not merged because the end_io handlers need to be able to do
298 * operations on them without sleeping (or doing allocations/splits).
300 * This should be called with the tree lock held.
302 static void merge_state(struct extent_io_tree
*tree
,
303 struct extent_state
*state
)
305 struct extent_state
*other
;
306 struct rb_node
*other_node
;
308 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
311 other_node
= rb_prev(&state
->rb_node
);
313 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
314 if (other
->end
== state
->start
- 1 &&
315 other
->state
== state
->state
) {
316 merge_cb(tree
, state
, other
);
317 state
->start
= other
->start
;
319 rb_erase(&other
->rb_node
, &tree
->state
);
320 free_extent_state(other
);
323 other_node
= rb_next(&state
->rb_node
);
325 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
326 if (other
->start
== state
->end
+ 1 &&
327 other
->state
== state
->state
) {
328 merge_cb(tree
, state
, other
);
329 state
->end
= other
->end
;
331 rb_erase(&other
->rb_node
, &tree
->state
);
332 free_extent_state(other
);
337 static void set_state_cb(struct extent_io_tree
*tree
,
338 struct extent_state
*state
, unsigned long *bits
)
340 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
341 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
, bits
);
344 static void clear_state_cb(struct extent_io_tree
*tree
,
345 struct extent_state
*state
, unsigned long *bits
)
347 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
348 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
, bits
);
351 static void set_state_bits(struct extent_io_tree
*tree
,
352 struct extent_state
*state
, unsigned long *bits
);
355 * insert an extent_state struct into the tree. 'bits' are set on the
356 * struct before it is inserted.
358 * This may return -EEXIST if the extent is already there, in which case the
359 * state struct is freed.
361 * The tree lock is not taken internally. This is a utility function and
362 * probably isn't what you want to call (see set/clear_extent_bit).
364 static int insert_state(struct extent_io_tree
*tree
,
365 struct extent_state
*state
, u64 start
, u64 end
,
368 struct rb_node
*node
;
371 WARN(1, KERN_ERR
"btrfs end < start %llu %llu\n",
372 (unsigned long long)end
,
373 (unsigned long long)start
);
374 state
->start
= start
;
377 set_state_bits(tree
, state
, bits
);
379 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
381 struct extent_state
*found
;
382 found
= rb_entry(node
, struct extent_state
, rb_node
);
383 printk(KERN_ERR
"btrfs found node %llu %llu on insert of "
384 "%llu %llu\n", (unsigned long long)found
->start
,
385 (unsigned long long)found
->end
,
386 (unsigned long long)start
, (unsigned long long)end
);
390 merge_state(tree
, state
);
394 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
397 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
398 tree
->ops
->split_extent_hook(tree
->mapping
->host
, orig
, split
);
402 * split a given extent state struct in two, inserting the preallocated
403 * struct 'prealloc' as the newly created second half. 'split' indicates an
404 * offset inside 'orig' where it should be split.
407 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
408 * are two extent state structs in the tree:
409 * prealloc: [orig->start, split - 1]
410 * orig: [ split, orig->end ]
412 * The tree locks are not taken by this function. They need to be held
415 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
416 struct extent_state
*prealloc
, u64 split
)
418 struct rb_node
*node
;
420 split_cb(tree
, orig
, split
);
422 prealloc
->start
= orig
->start
;
423 prealloc
->end
= split
- 1;
424 prealloc
->state
= orig
->state
;
427 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
429 free_extent_state(prealloc
);
432 prealloc
->tree
= tree
;
436 static struct extent_state
*next_state(struct extent_state
*state
)
438 struct rb_node
*next
= rb_next(&state
->rb_node
);
440 return rb_entry(next
, struct extent_state
, rb_node
);
446 * utility function to clear some bits in an extent state struct.
447 * it will optionally wake up any one waiting on this state (wake == 1).
449 * If no bits are set on the state struct after clearing things, the
450 * struct is freed and removed from the tree
452 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
453 struct extent_state
*state
,
454 unsigned long *bits
, int wake
)
456 struct extent_state
*next
;
457 unsigned long bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
459 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
460 u64 range
= state
->end
- state
->start
+ 1;
461 WARN_ON(range
> tree
->dirty_bytes
);
462 tree
->dirty_bytes
-= range
;
464 clear_state_cb(tree
, state
, bits
);
465 state
->state
&= ~bits_to_clear
;
468 if (state
->state
== 0) {
469 next
= next_state(state
);
471 rb_erase(&state
->rb_node
, &tree
->state
);
473 free_extent_state(state
);
478 merge_state(tree
, state
);
479 next
= next_state(state
);
484 static struct extent_state
*
485 alloc_extent_state_atomic(struct extent_state
*prealloc
)
488 prealloc
= alloc_extent_state(GFP_ATOMIC
);
493 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
495 btrfs_panic(tree_fs_info(tree
), err
, "Locking error: "
496 "Extent tree was modified by another "
497 "thread while locked.");
501 * clear some bits on a range in the tree. This may require splitting
502 * or inserting elements in the tree, so the gfp mask is used to
503 * indicate which allocations or sleeping are allowed.
505 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
506 * the given range from the tree regardless of state (ie for truncate).
508 * the range [start, end] is inclusive.
510 * This takes the tree lock, and returns 0 on success and < 0 on error.
512 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
513 unsigned long bits
, int wake
, int delete,
514 struct extent_state
**cached_state
,
517 struct extent_state
*state
;
518 struct extent_state
*cached
;
519 struct extent_state
*prealloc
= NULL
;
520 struct rb_node
*node
;
526 bits
|= ~EXTENT_CTLBITS
;
527 bits
|= EXTENT_FIRST_DELALLOC
;
529 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
532 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
533 prealloc
= alloc_extent_state(mask
);
538 spin_lock(&tree
->lock
);
540 cached
= *cached_state
;
543 *cached_state
= NULL
;
547 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
548 cached
->end
> start
) {
550 atomic_dec(&cached
->refs
);
555 free_extent_state(cached
);
558 * this search will find the extents that end after
561 node
= tree_search(tree
, start
);
564 state
= rb_entry(node
, struct extent_state
, rb_node
);
566 if (state
->start
> end
)
568 WARN_ON(state
->end
< start
);
569 last_end
= state
->end
;
571 /* the state doesn't have the wanted bits, go ahead */
572 if (!(state
->state
& bits
)) {
573 state
= next_state(state
);
578 * | ---- desired range ---- |
580 * | ------------- state -------------- |
582 * We need to split the extent we found, and may flip
583 * bits on second half.
585 * If the extent we found extends past our range, we
586 * just split and search again. It'll get split again
587 * the next time though.
589 * If the extent we found is inside our range, we clear
590 * the desired bit on it.
593 if (state
->start
< start
) {
594 prealloc
= alloc_extent_state_atomic(prealloc
);
596 err
= split_state(tree
, state
, prealloc
, start
);
598 extent_io_tree_panic(tree
, err
);
603 if (state
->end
<= end
) {
604 state
= clear_state_bit(tree
, state
, &bits
, wake
);
610 * | ---- desired range ---- |
612 * We need to split the extent, and clear the bit
615 if (state
->start
<= end
&& state
->end
> end
) {
616 prealloc
= alloc_extent_state_atomic(prealloc
);
618 err
= split_state(tree
, state
, prealloc
, end
+ 1);
620 extent_io_tree_panic(tree
, err
);
625 clear_state_bit(tree
, prealloc
, &bits
, wake
);
631 state
= clear_state_bit(tree
, state
, &bits
, wake
);
633 if (last_end
== (u64
)-1)
635 start
= last_end
+ 1;
636 if (start
<= end
&& state
&& !need_resched())
641 spin_unlock(&tree
->lock
);
643 free_extent_state(prealloc
);
650 spin_unlock(&tree
->lock
);
651 if (mask
& __GFP_WAIT
)
656 static void wait_on_state(struct extent_io_tree
*tree
,
657 struct extent_state
*state
)
658 __releases(tree
->lock
)
659 __acquires(tree
->lock
)
662 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
663 spin_unlock(&tree
->lock
);
665 spin_lock(&tree
->lock
);
666 finish_wait(&state
->wq
, &wait
);
670 * waits for one or more bits to clear on a range in the state tree.
671 * The range [start, end] is inclusive.
672 * The tree lock is taken by this function
674 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
677 struct extent_state
*state
;
678 struct rb_node
*node
;
680 spin_lock(&tree
->lock
);
684 * this search will find all the extents that end after
687 node
= tree_search(tree
, start
);
691 state
= rb_entry(node
, struct extent_state
, rb_node
);
693 if (state
->start
> end
)
696 if (state
->state
& bits
) {
697 start
= state
->start
;
698 atomic_inc(&state
->refs
);
699 wait_on_state(tree
, state
);
700 free_extent_state(state
);
703 start
= state
->end
+ 1;
708 cond_resched_lock(&tree
->lock
);
711 spin_unlock(&tree
->lock
);
714 static void set_state_bits(struct extent_io_tree
*tree
,
715 struct extent_state
*state
,
718 unsigned long bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
720 set_state_cb(tree
, state
, bits
);
721 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
722 u64 range
= state
->end
- state
->start
+ 1;
723 tree
->dirty_bytes
+= range
;
725 state
->state
|= bits_to_set
;
728 static void cache_state(struct extent_state
*state
,
729 struct extent_state
**cached_ptr
)
731 if (cached_ptr
&& !(*cached_ptr
)) {
732 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
)) {
734 atomic_inc(&state
->refs
);
739 static void uncache_state(struct extent_state
**cached_ptr
)
741 if (cached_ptr
&& (*cached_ptr
)) {
742 struct extent_state
*state
= *cached_ptr
;
744 free_extent_state(state
);
749 * set some bits on a range in the tree. This may require allocations or
750 * sleeping, so the gfp mask is used to indicate what is allowed.
752 * If any of the exclusive bits are set, this will fail with -EEXIST if some
753 * part of the range already has the desired bits set. The start of the
754 * existing range is returned in failed_start in this case.
756 * [start, end] is inclusive This takes the tree lock.
759 static int __must_check
760 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
761 unsigned long bits
, unsigned long exclusive_bits
,
762 u64
*failed_start
, struct extent_state
**cached_state
,
765 struct extent_state
*state
;
766 struct extent_state
*prealloc
= NULL
;
767 struct rb_node
*node
;
772 bits
|= EXTENT_FIRST_DELALLOC
;
774 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
775 prealloc
= alloc_extent_state(mask
);
779 spin_lock(&tree
->lock
);
780 if (cached_state
&& *cached_state
) {
781 state
= *cached_state
;
782 if (state
->start
<= start
&& state
->end
> start
&&
784 node
= &state
->rb_node
;
789 * this search will find all the extents that end after
792 node
= tree_search(tree
, start
);
794 prealloc
= alloc_extent_state_atomic(prealloc
);
796 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
798 extent_io_tree_panic(tree
, err
);
803 state
= rb_entry(node
, struct extent_state
, rb_node
);
805 last_start
= state
->start
;
806 last_end
= state
->end
;
809 * | ---- desired range ---- |
812 * Just lock what we found and keep going
814 if (state
->start
== start
&& state
->end
<= end
) {
815 if (state
->state
& exclusive_bits
) {
816 *failed_start
= state
->start
;
821 set_state_bits(tree
, state
, &bits
);
822 cache_state(state
, cached_state
);
823 merge_state(tree
, state
);
824 if (last_end
== (u64
)-1)
826 start
= last_end
+ 1;
827 state
= next_state(state
);
828 if (start
< end
&& state
&& state
->start
== start
&&
835 * | ---- desired range ---- |
838 * | ------------- state -------------- |
840 * We need to split the extent we found, and may flip bits on
843 * If the extent we found extends past our
844 * range, we just split and search again. It'll get split
845 * again the next time though.
847 * If the extent we found is inside our range, we set the
850 if (state
->start
< start
) {
851 if (state
->state
& exclusive_bits
) {
852 *failed_start
= start
;
857 prealloc
= alloc_extent_state_atomic(prealloc
);
859 err
= split_state(tree
, state
, prealloc
, start
);
861 extent_io_tree_panic(tree
, err
);
866 if (state
->end
<= end
) {
867 set_state_bits(tree
, state
, &bits
);
868 cache_state(state
, cached_state
);
869 merge_state(tree
, state
);
870 if (last_end
== (u64
)-1)
872 start
= last_end
+ 1;
873 state
= next_state(state
);
874 if (start
< end
&& state
&& state
->start
== start
&&
881 * | ---- desired range ---- |
882 * | state | or | state |
884 * There's a hole, we need to insert something in it and
885 * ignore the extent we found.
887 if (state
->start
> start
) {
889 if (end
< last_start
)
892 this_end
= last_start
- 1;
894 prealloc
= alloc_extent_state_atomic(prealloc
);
898 * Avoid to free 'prealloc' if it can be merged with
901 err
= insert_state(tree
, prealloc
, start
, this_end
,
904 extent_io_tree_panic(tree
, err
);
906 cache_state(prealloc
, cached_state
);
908 start
= this_end
+ 1;
912 * | ---- desired range ---- |
914 * We need to split the extent, and set the bit
917 if (state
->start
<= end
&& state
->end
> end
) {
918 if (state
->state
& exclusive_bits
) {
919 *failed_start
= start
;
924 prealloc
= alloc_extent_state_atomic(prealloc
);
926 err
= split_state(tree
, state
, prealloc
, end
+ 1);
928 extent_io_tree_panic(tree
, err
);
930 set_state_bits(tree
, prealloc
, &bits
);
931 cache_state(prealloc
, cached_state
);
932 merge_state(tree
, prealloc
);
940 spin_unlock(&tree
->lock
);
942 free_extent_state(prealloc
);
949 spin_unlock(&tree
->lock
);
950 if (mask
& __GFP_WAIT
)
955 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
956 unsigned long bits
, u64
* failed_start
,
957 struct extent_state
**cached_state
, gfp_t mask
)
959 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
965 * convert_extent_bit - convert all bits in a given range from one bit to
967 * @tree: the io tree to search
968 * @start: the start offset in bytes
969 * @end: the end offset in bytes (inclusive)
970 * @bits: the bits to set in this range
971 * @clear_bits: the bits to clear in this range
972 * @cached_state: state that we're going to cache
973 * @mask: the allocation mask
975 * This will go through and set bits for the given range. If any states exist
976 * already in this range they are set with the given bit and cleared of the
977 * clear_bits. This is only meant to be used by things that are mergeable, ie
978 * converting from say DELALLOC to DIRTY. This is not meant to be used with
979 * boundary bits like LOCK.
981 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
982 unsigned long bits
, unsigned long clear_bits
,
983 struct extent_state
**cached_state
, gfp_t mask
)
985 struct extent_state
*state
;
986 struct extent_state
*prealloc
= NULL
;
987 struct rb_node
*node
;
993 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
994 prealloc
= alloc_extent_state(mask
);
999 spin_lock(&tree
->lock
);
1000 if (cached_state
&& *cached_state
) {
1001 state
= *cached_state
;
1002 if (state
->start
<= start
&& state
->end
> start
&&
1004 node
= &state
->rb_node
;
1010 * this search will find all the extents that end after
1013 node
= tree_search(tree
, start
);
1015 prealloc
= alloc_extent_state_atomic(prealloc
);
1020 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
1023 extent_io_tree_panic(tree
, err
);
1026 state
= rb_entry(node
, struct extent_state
, rb_node
);
1028 last_start
= state
->start
;
1029 last_end
= state
->end
;
1032 * | ---- desired range ---- |
1035 * Just lock what we found and keep going
1037 if (state
->start
== start
&& state
->end
<= end
) {
1038 set_state_bits(tree
, state
, &bits
);
1039 cache_state(state
, cached_state
);
1040 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1041 if (last_end
== (u64
)-1)
1043 start
= last_end
+ 1;
1044 if (start
< end
&& state
&& state
->start
== start
&&
1051 * | ---- desired range ---- |
1054 * | ------------- state -------------- |
1056 * We need to split the extent we found, and may flip bits on
1059 * If the extent we found extends past our
1060 * range, we just split and search again. It'll get split
1061 * again the next time though.
1063 * If the extent we found is inside our range, we set the
1064 * desired bit on it.
1066 if (state
->start
< start
) {
1067 prealloc
= alloc_extent_state_atomic(prealloc
);
1072 err
= split_state(tree
, state
, prealloc
, start
);
1074 extent_io_tree_panic(tree
, err
);
1078 if (state
->end
<= end
) {
1079 set_state_bits(tree
, state
, &bits
);
1080 cache_state(state
, cached_state
);
1081 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1082 if (last_end
== (u64
)-1)
1084 start
= last_end
+ 1;
1085 if (start
< end
&& state
&& state
->start
== start
&&
1092 * | ---- desired range ---- |
1093 * | state | or | state |
1095 * There's a hole, we need to insert something in it and
1096 * ignore the extent we found.
1098 if (state
->start
> start
) {
1100 if (end
< last_start
)
1103 this_end
= last_start
- 1;
1105 prealloc
= alloc_extent_state_atomic(prealloc
);
1112 * Avoid to free 'prealloc' if it can be merged with
1115 err
= insert_state(tree
, prealloc
, start
, this_end
,
1118 extent_io_tree_panic(tree
, err
);
1119 cache_state(prealloc
, cached_state
);
1121 start
= this_end
+ 1;
1125 * | ---- desired range ---- |
1127 * We need to split the extent, and set the bit
1130 if (state
->start
<= end
&& state
->end
> end
) {
1131 prealloc
= alloc_extent_state_atomic(prealloc
);
1137 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1139 extent_io_tree_panic(tree
, err
);
1141 set_state_bits(tree
, prealloc
, &bits
);
1142 cache_state(prealloc
, cached_state
);
1143 clear_state_bit(tree
, prealloc
, &clear_bits
, 0);
1151 spin_unlock(&tree
->lock
);
1153 free_extent_state(prealloc
);
1160 spin_unlock(&tree
->lock
);
1161 if (mask
& __GFP_WAIT
)
1166 /* wrappers around set/clear extent bit */
1167 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1170 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, NULL
,
1174 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1175 unsigned long bits
, gfp_t mask
)
1177 return set_extent_bit(tree
, start
, end
, bits
, NULL
,
1181 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1182 unsigned long bits
, gfp_t mask
)
1184 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, mask
);
1187 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1188 struct extent_state
**cached_state
, gfp_t mask
)
1190 return set_extent_bit(tree
, start
, end
,
1191 EXTENT_DELALLOC
| EXTENT_UPTODATE
,
1192 NULL
, cached_state
, mask
);
1195 int set_extent_defrag(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1196 struct extent_state
**cached_state
, gfp_t mask
)
1198 return set_extent_bit(tree
, start
, end
,
1199 EXTENT_DELALLOC
| EXTENT_UPTODATE
| EXTENT_DEFRAG
,
1200 NULL
, cached_state
, mask
);
1203 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1206 return clear_extent_bit(tree
, start
, end
,
1207 EXTENT_DIRTY
| EXTENT_DELALLOC
|
1208 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
, mask
);
1211 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1214 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, NULL
,
1218 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1219 struct extent_state
**cached_state
, gfp_t mask
)
1221 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, NULL
,
1222 cached_state
, mask
);
1225 int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1226 struct extent_state
**cached_state
, gfp_t mask
)
1228 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0,
1229 cached_state
, mask
);
1233 * either insert or lock state struct between start and end use mask to tell
1234 * us if waiting is desired.
1236 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1237 unsigned long bits
, struct extent_state
**cached_state
)
1242 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
1243 EXTENT_LOCKED
, &failed_start
,
1244 cached_state
, GFP_NOFS
);
1245 if (err
== -EEXIST
) {
1246 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1247 start
= failed_start
;
1250 WARN_ON(start
> end
);
1255 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1257 return lock_extent_bits(tree
, start
, end
, 0, NULL
);
1260 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1265 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1266 &failed_start
, NULL
, GFP_NOFS
);
1267 if (err
== -EEXIST
) {
1268 if (failed_start
> start
)
1269 clear_extent_bit(tree
, start
, failed_start
- 1,
1270 EXTENT_LOCKED
, 1, 0, NULL
, GFP_NOFS
);
1276 int unlock_extent_cached(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1277 struct extent_state
**cached
, gfp_t mask
)
1279 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, cached
,
1283 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1285 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, NULL
,
1289 int extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1291 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1292 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1295 while (index
<= end_index
) {
1296 page
= find_get_page(inode
->i_mapping
, index
);
1297 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1298 clear_page_dirty_for_io(page
);
1299 page_cache_release(page
);
1305 int extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1307 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1308 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1311 while (index
<= end_index
) {
1312 page
= find_get_page(inode
->i_mapping
, index
);
1313 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1314 account_page_redirty(page
);
1315 __set_page_dirty_nobuffers(page
);
1316 page_cache_release(page
);
1323 * helper function to set both pages and extents in the tree writeback
1325 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1327 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1328 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1331 while (index
<= end_index
) {
1332 page
= find_get_page(tree
->mapping
, index
);
1333 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1334 set_page_writeback(page
);
1335 page_cache_release(page
);
1341 /* find the first state struct with 'bits' set after 'start', and
1342 * return it. tree->lock must be held. NULL will returned if
1343 * nothing was found after 'start'
1345 static struct extent_state
*
1346 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1347 u64 start
, unsigned long bits
)
1349 struct rb_node
*node
;
1350 struct extent_state
*state
;
1353 * this search will find all the extents that end after
1356 node
= tree_search(tree
, start
);
1361 state
= rb_entry(node
, struct extent_state
, rb_node
);
1362 if (state
->end
>= start
&& (state
->state
& bits
))
1365 node
= rb_next(node
);
1374 * find the first offset in the io tree with 'bits' set. zero is
1375 * returned if we find something, and *start_ret and *end_ret are
1376 * set to reflect the state struct that was found.
1378 * If nothing was found, 1 is returned. If found something, return 0.
1380 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1381 u64
*start_ret
, u64
*end_ret
, unsigned long bits
,
1382 struct extent_state
**cached_state
)
1384 struct extent_state
*state
;
1388 spin_lock(&tree
->lock
);
1389 if (cached_state
&& *cached_state
) {
1390 state
= *cached_state
;
1391 if (state
->end
== start
- 1 && state
->tree
) {
1392 n
= rb_next(&state
->rb_node
);
1394 state
= rb_entry(n
, struct extent_state
,
1396 if (state
->state
& bits
)
1400 free_extent_state(*cached_state
);
1401 *cached_state
= NULL
;
1404 free_extent_state(*cached_state
);
1405 *cached_state
= NULL
;
1408 state
= find_first_extent_bit_state(tree
, start
, bits
);
1411 cache_state(state
, cached_state
);
1412 *start_ret
= state
->start
;
1413 *end_ret
= state
->end
;
1417 spin_unlock(&tree
->lock
);
1422 * find a contiguous range of bytes in the file marked as delalloc, not
1423 * more than 'max_bytes'. start and end are used to return the range,
1425 * 1 is returned if we find something, 0 if nothing was in the tree
1427 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1428 u64
*start
, u64
*end
, u64 max_bytes
,
1429 struct extent_state
**cached_state
)
1431 struct rb_node
*node
;
1432 struct extent_state
*state
;
1433 u64 cur_start
= *start
;
1435 u64 total_bytes
= 0;
1437 spin_lock(&tree
->lock
);
1440 * this search will find all the extents that end after
1443 node
= tree_search(tree
, cur_start
);
1451 state
= rb_entry(node
, struct extent_state
, rb_node
);
1452 if (found
&& (state
->start
!= cur_start
||
1453 (state
->state
& EXTENT_BOUNDARY
))) {
1456 if (!(state
->state
& EXTENT_DELALLOC
)) {
1462 *start
= state
->start
;
1463 *cached_state
= state
;
1464 atomic_inc(&state
->refs
);
1468 cur_start
= state
->end
+ 1;
1469 node
= rb_next(node
);
1472 total_bytes
+= state
->end
- state
->start
+ 1;
1473 if (total_bytes
>= max_bytes
)
1477 spin_unlock(&tree
->lock
);
1481 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1482 struct page
*locked_page
,
1486 struct page
*pages
[16];
1487 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1488 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1489 unsigned long nr_pages
= end_index
- index
+ 1;
1492 if (index
== locked_page
->index
&& end_index
== index
)
1495 while (nr_pages
> 0) {
1496 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1497 min_t(unsigned long, nr_pages
,
1498 ARRAY_SIZE(pages
)), pages
);
1499 for (i
= 0; i
< ret
; i
++) {
1500 if (pages
[i
] != locked_page
)
1501 unlock_page(pages
[i
]);
1502 page_cache_release(pages
[i
]);
1510 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1511 struct page
*locked_page
,
1515 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1516 unsigned long start_index
= index
;
1517 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1518 unsigned long pages_locked
= 0;
1519 struct page
*pages
[16];
1520 unsigned long nrpages
;
1524 /* the caller is responsible for locking the start index */
1525 if (index
== locked_page
->index
&& index
== end_index
)
1528 /* skip the page at the start index */
1529 nrpages
= end_index
- index
+ 1;
1530 while (nrpages
> 0) {
1531 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1532 min_t(unsigned long,
1533 nrpages
, ARRAY_SIZE(pages
)), pages
);
1538 /* now we have an array of pages, lock them all */
1539 for (i
= 0; i
< ret
; i
++) {
1541 * the caller is taking responsibility for
1544 if (pages
[i
] != locked_page
) {
1545 lock_page(pages
[i
]);
1546 if (!PageDirty(pages
[i
]) ||
1547 pages
[i
]->mapping
!= inode
->i_mapping
) {
1549 unlock_page(pages
[i
]);
1550 page_cache_release(pages
[i
]);
1554 page_cache_release(pages
[i
]);
1563 if (ret
&& pages_locked
) {
1564 __unlock_for_delalloc(inode
, locked_page
,
1566 ((u64
)(start_index
+ pages_locked
- 1)) <<
1573 * find a contiguous range of bytes in the file marked as delalloc, not
1574 * more than 'max_bytes'. start and end are used to return the range,
1576 * 1 is returned if we find something, 0 if nothing was in the tree
1578 static noinline u64
find_lock_delalloc_range(struct inode
*inode
,
1579 struct extent_io_tree
*tree
,
1580 struct page
*locked_page
,
1581 u64
*start
, u64
*end
,
1587 struct extent_state
*cached_state
= NULL
;
1592 /* step one, find a bunch of delalloc bytes starting at start */
1593 delalloc_start
= *start
;
1595 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1596 max_bytes
, &cached_state
);
1597 if (!found
|| delalloc_end
<= *start
) {
1598 *start
= delalloc_start
;
1599 *end
= delalloc_end
;
1600 free_extent_state(cached_state
);
1605 * start comes from the offset of locked_page. We have to lock
1606 * pages in order, so we can't process delalloc bytes before
1609 if (delalloc_start
< *start
)
1610 delalloc_start
= *start
;
1613 * make sure to limit the number of pages we try to lock down
1616 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
&& loops
)
1617 delalloc_end
= delalloc_start
+ PAGE_CACHE_SIZE
- 1;
1619 /* step two, lock all the pages after the page that has start */
1620 ret
= lock_delalloc_pages(inode
, locked_page
,
1621 delalloc_start
, delalloc_end
);
1622 if (ret
== -EAGAIN
) {
1623 /* some of the pages are gone, lets avoid looping by
1624 * shortening the size of the delalloc range we're searching
1626 free_extent_state(cached_state
);
1628 unsigned long offset
= (*start
) & (PAGE_CACHE_SIZE
- 1);
1629 max_bytes
= PAGE_CACHE_SIZE
- offset
;
1637 BUG_ON(ret
); /* Only valid values are 0 and -EAGAIN */
1639 /* step three, lock the state bits for the whole range */
1640 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, 0, &cached_state
);
1642 /* then test to make sure it is all still delalloc */
1643 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1644 EXTENT_DELALLOC
, 1, cached_state
);
1646 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1647 &cached_state
, GFP_NOFS
);
1648 __unlock_for_delalloc(inode
, locked_page
,
1649 delalloc_start
, delalloc_end
);
1653 free_extent_state(cached_state
);
1654 *start
= delalloc_start
;
1655 *end
= delalloc_end
;
1660 int extent_clear_unlock_delalloc(struct inode
*inode
,
1661 struct extent_io_tree
*tree
,
1662 u64 start
, u64 end
, struct page
*locked_page
,
1666 struct page
*pages
[16];
1667 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1668 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1669 unsigned long nr_pages
= end_index
- index
+ 1;
1671 unsigned long clear_bits
= 0;
1673 if (op
& EXTENT_CLEAR_UNLOCK
)
1674 clear_bits
|= EXTENT_LOCKED
;
1675 if (op
& EXTENT_CLEAR_DIRTY
)
1676 clear_bits
|= EXTENT_DIRTY
;
1678 if (op
& EXTENT_CLEAR_DELALLOC
)
1679 clear_bits
|= EXTENT_DELALLOC
;
1681 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, NULL
, GFP_NOFS
);
1682 if (!(op
& (EXTENT_CLEAR_UNLOCK_PAGE
| EXTENT_CLEAR_DIRTY
|
1683 EXTENT_SET_WRITEBACK
| EXTENT_END_WRITEBACK
|
1684 EXTENT_SET_PRIVATE2
)))
1687 while (nr_pages
> 0) {
1688 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1689 min_t(unsigned long,
1690 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1691 for (i
= 0; i
< ret
; i
++) {
1693 if (op
& EXTENT_SET_PRIVATE2
)
1694 SetPagePrivate2(pages
[i
]);
1696 if (pages
[i
] == locked_page
) {
1697 page_cache_release(pages
[i
]);
1700 if (op
& EXTENT_CLEAR_DIRTY
)
1701 clear_page_dirty_for_io(pages
[i
]);
1702 if (op
& EXTENT_SET_WRITEBACK
)
1703 set_page_writeback(pages
[i
]);
1704 if (op
& EXTENT_END_WRITEBACK
)
1705 end_page_writeback(pages
[i
]);
1706 if (op
& EXTENT_CLEAR_UNLOCK_PAGE
)
1707 unlock_page(pages
[i
]);
1708 page_cache_release(pages
[i
]);
1718 * count the number of bytes in the tree that have a given bit(s)
1719 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1720 * cached. The total number found is returned.
1722 u64
count_range_bits(struct extent_io_tree
*tree
,
1723 u64
*start
, u64 search_end
, u64 max_bytes
,
1724 unsigned long bits
, int contig
)
1726 struct rb_node
*node
;
1727 struct extent_state
*state
;
1728 u64 cur_start
= *start
;
1729 u64 total_bytes
= 0;
1733 if (search_end
<= cur_start
) {
1738 spin_lock(&tree
->lock
);
1739 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1740 total_bytes
= tree
->dirty_bytes
;
1744 * this search will find all the extents that end after
1747 node
= tree_search(tree
, cur_start
);
1752 state
= rb_entry(node
, struct extent_state
, rb_node
);
1753 if (state
->start
> search_end
)
1755 if (contig
&& found
&& state
->start
> last
+ 1)
1757 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1758 total_bytes
+= min(search_end
, state
->end
) + 1 -
1759 max(cur_start
, state
->start
);
1760 if (total_bytes
>= max_bytes
)
1763 *start
= max(cur_start
, state
->start
);
1767 } else if (contig
&& found
) {
1770 node
= rb_next(node
);
1775 spin_unlock(&tree
->lock
);
1780 * set the private field for a given byte offset in the tree. If there isn't
1781 * an extent_state there already, this does nothing.
1783 int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1785 struct rb_node
*node
;
1786 struct extent_state
*state
;
1789 spin_lock(&tree
->lock
);
1791 * this search will find all the extents that end after
1794 node
= tree_search(tree
, start
);
1799 state
= rb_entry(node
, struct extent_state
, rb_node
);
1800 if (state
->start
!= start
) {
1804 state
->private = private;
1806 spin_unlock(&tree
->lock
);
1810 void extent_cache_csums_dio(struct extent_io_tree
*tree
, u64 start
, u32 csums
[],
1813 struct rb_node
*node
;
1814 struct extent_state
*state
;
1816 spin_lock(&tree
->lock
);
1818 * this search will find all the extents that end after
1821 node
= tree_search(tree
, start
);
1824 state
= rb_entry(node
, struct extent_state
, rb_node
);
1825 BUG_ON(state
->start
!= start
);
1828 state
->private = *csums
++;
1830 state
= next_state(state
);
1832 spin_unlock(&tree
->lock
);
1835 static inline u64
__btrfs_get_bio_offset(struct bio
*bio
, int bio_index
)
1837 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio_index
;
1839 return page_offset(bvec
->bv_page
) + bvec
->bv_offset
;
1842 void extent_cache_csums(struct extent_io_tree
*tree
, struct bio
*bio
, int bio_index
,
1843 u32 csums
[], int count
)
1845 struct rb_node
*node
;
1846 struct extent_state
*state
= NULL
;
1849 spin_lock(&tree
->lock
);
1851 start
= __btrfs_get_bio_offset(bio
, bio_index
);
1852 if (state
== NULL
|| state
->start
!= start
) {
1853 node
= tree_search(tree
, start
);
1856 state
= rb_entry(node
, struct extent_state
, rb_node
);
1857 BUG_ON(state
->start
!= start
);
1859 state
->private = *csums
++;
1863 state
= next_state(state
);
1865 spin_unlock(&tree
->lock
);
1868 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1870 struct rb_node
*node
;
1871 struct extent_state
*state
;
1874 spin_lock(&tree
->lock
);
1876 * this search will find all the extents that end after
1879 node
= tree_search(tree
, start
);
1884 state
= rb_entry(node
, struct extent_state
, rb_node
);
1885 if (state
->start
!= start
) {
1889 *private = state
->private;
1891 spin_unlock(&tree
->lock
);
1896 * searches a range in the state tree for a given mask.
1897 * If 'filled' == 1, this returns 1 only if every extent in the tree
1898 * has the bits set. Otherwise, 1 is returned if any bit in the
1899 * range is found set.
1901 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1902 unsigned long bits
, int filled
, struct extent_state
*cached
)
1904 struct extent_state
*state
= NULL
;
1905 struct rb_node
*node
;
1908 spin_lock(&tree
->lock
);
1909 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
1910 cached
->end
> start
)
1911 node
= &cached
->rb_node
;
1913 node
= tree_search(tree
, start
);
1914 while (node
&& start
<= end
) {
1915 state
= rb_entry(node
, struct extent_state
, rb_node
);
1917 if (filled
&& state
->start
> start
) {
1922 if (state
->start
> end
)
1925 if (state
->state
& bits
) {
1929 } else if (filled
) {
1934 if (state
->end
== (u64
)-1)
1937 start
= state
->end
+ 1;
1940 node
= rb_next(node
);
1947 spin_unlock(&tree
->lock
);
1952 * helper function to set a given page up to date if all the
1953 * extents in the tree for that page are up to date
1955 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
1957 u64 start
= page_offset(page
);
1958 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1959 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1960 SetPageUptodate(page
);
1964 * When IO fails, either with EIO or csum verification fails, we
1965 * try other mirrors that might have a good copy of the data. This
1966 * io_failure_record is used to record state as we go through all the
1967 * mirrors. If another mirror has good data, the page is set up to date
1968 * and things continue. If a good mirror can't be found, the original
1969 * bio end_io callback is called to indicate things have failed.
1971 struct io_failure_record
{
1976 unsigned long bio_flags
;
1982 static int free_io_failure(struct inode
*inode
, struct io_failure_record
*rec
,
1987 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
1989 set_state_private(failure_tree
, rec
->start
, 0);
1990 ret
= clear_extent_bits(failure_tree
, rec
->start
,
1991 rec
->start
+ rec
->len
- 1,
1992 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
1996 ret
= clear_extent_bits(&BTRFS_I(inode
)->io_tree
, rec
->start
,
1997 rec
->start
+ rec
->len
- 1,
1998 EXTENT_DAMAGED
, GFP_NOFS
);
2006 static void repair_io_failure_callback(struct bio
*bio
, int err
)
2008 complete(bio
->bi_private
);
2012 * this bypasses the standard btrfs submit functions deliberately, as
2013 * the standard behavior is to write all copies in a raid setup. here we only
2014 * want to write the one bad copy. so we do the mapping for ourselves and issue
2015 * submit_bio directly.
2016 * to avoid any synchronization issues, wait for the data after writing, which
2017 * actually prevents the read that triggered the error from finishing.
2018 * currently, there can be no more than two copies of every data bit. thus,
2019 * exactly one rewrite is required.
2021 int repair_io_failure(struct btrfs_fs_info
*fs_info
, u64 start
,
2022 u64 length
, u64 logical
, struct page
*page
,
2026 struct btrfs_device
*dev
;
2027 DECLARE_COMPLETION_ONSTACK(compl);
2030 struct btrfs_bio
*bbio
= NULL
;
2031 struct btrfs_mapping_tree
*map_tree
= &fs_info
->mapping_tree
;
2034 BUG_ON(!mirror_num
);
2036 /* we can't repair anything in raid56 yet */
2037 if (btrfs_is_parity_mirror(map_tree
, logical
, length
, mirror_num
))
2040 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2043 bio
->bi_private
= &compl;
2044 bio
->bi_end_io
= repair_io_failure_callback
;
2046 map_length
= length
;
2048 ret
= btrfs_map_block(fs_info
, WRITE
, logical
,
2049 &map_length
, &bbio
, mirror_num
);
2054 BUG_ON(mirror_num
!= bbio
->mirror_num
);
2055 sector
= bbio
->stripes
[mirror_num
-1].physical
>> 9;
2056 bio
->bi_sector
= sector
;
2057 dev
= bbio
->stripes
[mirror_num
-1].dev
;
2059 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2063 bio
->bi_bdev
= dev
->bdev
;
2064 bio_add_page(bio
, page
, length
, start
- page_offset(page
));
2065 btrfsic_submit_bio(WRITE_SYNC
, bio
);
2066 wait_for_completion(&compl);
2068 if (!test_bit(BIO_UPTODATE
, &bio
->bi_flags
)) {
2069 /* try to remap that extent elsewhere? */
2071 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2075 printk_ratelimited_in_rcu(KERN_INFO
"btrfs read error corrected: ino %lu off %llu "
2076 "(dev %s sector %llu)\n", page
->mapping
->host
->i_ino
,
2077 start
, rcu_str_deref(dev
->name
), sector
);
2083 int repair_eb_io_failure(struct btrfs_root
*root
, struct extent_buffer
*eb
,
2086 u64 start
= eb
->start
;
2087 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2090 for (i
= 0; i
< num_pages
; i
++) {
2091 struct page
*p
= extent_buffer_page(eb
, i
);
2092 ret
= repair_io_failure(root
->fs_info
, start
, PAGE_CACHE_SIZE
,
2093 start
, p
, mirror_num
);
2096 start
+= PAGE_CACHE_SIZE
;
2103 * each time an IO finishes, we do a fast check in the IO failure tree
2104 * to see if we need to process or clean up an io_failure_record
2106 static int clean_io_failure(u64 start
, struct page
*page
)
2109 u64 private_failure
;
2110 struct io_failure_record
*failrec
;
2111 struct btrfs_fs_info
*fs_info
;
2112 struct extent_state
*state
;
2116 struct inode
*inode
= page
->mapping
->host
;
2119 ret
= count_range_bits(&BTRFS_I(inode
)->io_failure_tree
, &private,
2120 (u64
)-1, 1, EXTENT_DIRTY
, 0);
2124 ret
= get_state_private(&BTRFS_I(inode
)->io_failure_tree
, start
,
2129 failrec
= (struct io_failure_record
*)(unsigned long) private_failure
;
2130 BUG_ON(!failrec
->this_mirror
);
2132 if (failrec
->in_validation
) {
2133 /* there was no real error, just free the record */
2134 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2140 spin_lock(&BTRFS_I(inode
)->io_tree
.lock
);
2141 state
= find_first_extent_bit_state(&BTRFS_I(inode
)->io_tree
,
2144 spin_unlock(&BTRFS_I(inode
)->io_tree
.lock
);
2146 if (state
&& state
->start
== failrec
->start
) {
2147 fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2148 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2150 if (num_copies
> 1) {
2151 ret
= repair_io_failure(fs_info
, start
, failrec
->len
,
2152 failrec
->logical
, page
,
2153 failrec
->failed_mirror
);
2161 ret
= free_io_failure(inode
, failrec
, did_repair
);
2167 * this is a generic handler for readpage errors (default
2168 * readpage_io_failed_hook). if other copies exist, read those and write back
2169 * good data to the failed position. does not investigate in remapping the
2170 * failed extent elsewhere, hoping the device will be smart enough to do this as
2174 static int bio_readpage_error(struct bio
*failed_bio
, struct page
*page
,
2175 u64 start
, u64 end
, int failed_mirror
,
2176 struct extent_state
*state
)
2178 struct io_failure_record
*failrec
= NULL
;
2180 struct extent_map
*em
;
2181 struct inode
*inode
= page
->mapping
->host
;
2182 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2183 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2184 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2191 BUG_ON(failed_bio
->bi_rw
& REQ_WRITE
);
2193 ret
= get_state_private(failure_tree
, start
, &private);
2195 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2198 failrec
->start
= start
;
2199 failrec
->len
= end
- start
+ 1;
2200 failrec
->this_mirror
= 0;
2201 failrec
->bio_flags
= 0;
2202 failrec
->in_validation
= 0;
2204 read_lock(&em_tree
->lock
);
2205 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2207 read_unlock(&em_tree
->lock
);
2212 if (em
->start
> start
|| em
->start
+ em
->len
< start
) {
2213 free_extent_map(em
);
2216 read_unlock(&em_tree
->lock
);
2222 logical
= start
- em
->start
;
2223 logical
= em
->block_start
+ logical
;
2224 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2225 logical
= em
->block_start
;
2226 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2227 extent_set_compress_type(&failrec
->bio_flags
,
2230 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2231 "len=%llu\n", logical
, start
, failrec
->len
);
2232 failrec
->logical
= logical
;
2233 free_extent_map(em
);
2235 /* set the bits in the private failure tree */
2236 ret
= set_extent_bits(failure_tree
, start
, end
,
2237 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
2239 ret
= set_state_private(failure_tree
, start
,
2240 (u64
)(unsigned long)failrec
);
2241 /* set the bits in the inode's tree */
2243 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
,
2250 failrec
= (struct io_failure_record
*)(unsigned long)private;
2251 pr_debug("bio_readpage_error: (found) logical=%llu, "
2252 "start=%llu, len=%llu, validation=%d\n",
2253 failrec
->logical
, failrec
->start
, failrec
->len
,
2254 failrec
->in_validation
);
2256 * when data can be on disk more than twice, add to failrec here
2257 * (e.g. with a list for failed_mirror) to make
2258 * clean_io_failure() clean all those errors at once.
2261 num_copies
= btrfs_num_copies(BTRFS_I(inode
)->root
->fs_info
,
2262 failrec
->logical
, failrec
->len
);
2263 if (num_copies
== 1) {
2265 * we only have a single copy of the data, so don't bother with
2266 * all the retry and error correction code that follows. no
2267 * matter what the error is, it is very likely to persist.
2269 pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
2270 "state=%p, num_copies=%d, next_mirror %d, "
2271 "failed_mirror %d\n", state
, num_copies
,
2272 failrec
->this_mirror
, failed_mirror
);
2273 free_io_failure(inode
, failrec
, 0);
2278 spin_lock(&tree
->lock
);
2279 state
= find_first_extent_bit_state(tree
, failrec
->start
,
2281 if (state
&& state
->start
!= failrec
->start
)
2283 spin_unlock(&tree
->lock
);
2287 * there are two premises:
2288 * a) deliver good data to the caller
2289 * b) correct the bad sectors on disk
2291 if (failed_bio
->bi_vcnt
> 1) {
2293 * to fulfill b), we need to know the exact failing sectors, as
2294 * we don't want to rewrite any more than the failed ones. thus,
2295 * we need separate read requests for the failed bio
2297 * if the following BUG_ON triggers, our validation request got
2298 * merged. we need separate requests for our algorithm to work.
2300 BUG_ON(failrec
->in_validation
);
2301 failrec
->in_validation
= 1;
2302 failrec
->this_mirror
= failed_mirror
;
2303 read_mode
= READ_SYNC
| REQ_FAILFAST_DEV
;
2306 * we're ready to fulfill a) and b) alongside. get a good copy
2307 * of the failed sector and if we succeed, we have setup
2308 * everything for repair_io_failure to do the rest for us.
2310 if (failrec
->in_validation
) {
2311 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2312 failrec
->in_validation
= 0;
2313 failrec
->this_mirror
= 0;
2315 failrec
->failed_mirror
= failed_mirror
;
2316 failrec
->this_mirror
++;
2317 if (failrec
->this_mirror
== failed_mirror
)
2318 failrec
->this_mirror
++;
2319 read_mode
= READ_SYNC
;
2322 if (!state
|| failrec
->this_mirror
> num_copies
) {
2323 pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
2324 "next_mirror %d, failed_mirror %d\n", state
,
2325 num_copies
, failrec
->this_mirror
, failed_mirror
);
2326 free_io_failure(inode
, failrec
, 0);
2330 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2332 free_io_failure(inode
, failrec
, 0);
2335 bio
->bi_private
= state
;
2336 bio
->bi_end_io
= failed_bio
->bi_end_io
;
2337 bio
->bi_sector
= failrec
->logical
>> 9;
2338 bio
->bi_bdev
= BTRFS_I(inode
)->root
->fs_info
->fs_devices
->latest_bdev
;
2341 bio_add_page(bio
, page
, failrec
->len
, start
- page_offset(page
));
2343 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2344 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode
,
2345 failrec
->this_mirror
, num_copies
, failrec
->in_validation
);
2347 ret
= tree
->ops
->submit_bio_hook(inode
, read_mode
, bio
,
2348 failrec
->this_mirror
,
2349 failrec
->bio_flags
, 0);
2353 /* lots and lots of room for performance fixes in the end_bio funcs */
2355 int end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2357 int uptodate
= (err
== 0);
2358 struct extent_io_tree
*tree
;
2361 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2363 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
2364 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
2365 end
, NULL
, uptodate
);
2371 ClearPageUptodate(page
);
2378 * after a writepage IO is done, we need to:
2379 * clear the uptodate bits on error
2380 * clear the writeback bits in the extent tree for this IO
2381 * end_page_writeback if the page has no more pending IO
2383 * Scheduling is not allowed, so the extent state tree is expected
2384 * to have one and only one object corresponding to this IO.
2386 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
2388 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2389 struct extent_io_tree
*tree
;
2394 struct page
*page
= bvec
->bv_page
;
2395 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2397 /* We always issue full-page reads, but if some block
2398 * in a page fails to read, blk_update_request() will
2399 * advance bv_offset and adjust bv_len to compensate.
2400 * Print a warning for nonzero offsets, and an error
2401 * if they don't add up to a full page. */
2402 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2403 printk("%s page write in btrfs with offset %u and length %u\n",
2404 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2405 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2406 bvec
->bv_offset
, bvec
->bv_len
);
2408 start
= page_offset(page
);
2409 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2411 if (--bvec
>= bio
->bi_io_vec
)
2412 prefetchw(&bvec
->bv_page
->flags
);
2414 if (end_extent_writepage(page
, err
, start
, end
))
2417 end_page_writeback(page
);
2418 } while (bvec
>= bio
->bi_io_vec
);
2424 * after a readpage IO is done, we need to:
2425 * clear the uptodate bits on error
2426 * set the uptodate bits if things worked
2427 * set the page up to date if all extents in the tree are uptodate
2428 * clear the lock bit in the extent tree
2429 * unlock the page if there are no other extents locked for it
2431 * Scheduling is not allowed, so the extent state tree is expected
2432 * to have one and only one object corresponding to this IO.
2434 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
2436 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2437 struct bio_vec
*bvec_end
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2438 struct bio_vec
*bvec
= bio
->bi_io_vec
;
2439 struct extent_io_tree
*tree
;
2449 struct page
*page
= bvec
->bv_page
;
2450 struct extent_state
*cached
= NULL
;
2451 struct extent_state
*state
;
2452 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2454 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2455 "mirror=%lu\n", (u64
)bio
->bi_sector
, err
,
2456 io_bio
->mirror_num
);
2457 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2459 /* We always issue full-page reads, but if some block
2460 * in a page fails to read, blk_update_request() will
2461 * advance bv_offset and adjust bv_len to compensate.
2462 * Print a warning for nonzero offsets, and an error
2463 * if they don't add up to a full page. */
2464 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2465 printk("%s page read in btrfs with offset %u and length %u\n",
2466 bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
2467 ? KERN_ERR
"partial" : KERN_INFO
"incomplete",
2468 bvec
->bv_offset
, bvec
->bv_len
);
2470 start
= page_offset(page
);
2471 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2473 if (++bvec
<= bvec_end
)
2474 prefetchw(&bvec
->bv_page
->flags
);
2476 spin_lock(&tree
->lock
);
2477 state
= find_first_extent_bit_state(tree
, start
, EXTENT_LOCKED
);
2478 if (state
&& state
->start
== start
) {
2480 * take a reference on the state, unlock will drop
2483 cache_state(state
, &cached
);
2485 spin_unlock(&tree
->lock
);
2487 mirror
= io_bio
->mirror_num
;
2488 if (uptodate
&& tree
->ops
&& tree
->ops
->readpage_end_io_hook
) {
2489 ret
= tree
->ops
->readpage_end_io_hook(page
, start
, end
,
2494 clean_io_failure(start
, page
);
2497 if (!uptodate
&& tree
->ops
&& tree
->ops
->readpage_io_failed_hook
) {
2498 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2500 test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
2502 } else if (!uptodate
) {
2504 * The generic bio_readpage_error handles errors the
2505 * following way: If possible, new read requests are
2506 * created and submitted and will end up in
2507 * end_bio_extent_readpage as well (if we're lucky, not
2508 * in the !uptodate case). In that case it returns 0 and
2509 * we just go on with the next page in our bio. If it
2510 * can't handle the error it will return -EIO and we
2511 * remain responsible for that page.
2513 ret
= bio_readpage_error(bio
, page
, start
, end
, mirror
, NULL
);
2516 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2519 uncache_state(&cached
);
2524 if (uptodate
&& tree
->track_uptodate
) {
2525 set_extent_uptodate(tree
, start
, end
, &cached
,
2528 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2531 SetPageUptodate(page
);
2533 ClearPageUptodate(page
);
2537 } while (bvec
<= bvec_end
);
2543 * this allocates from the btrfs_bioset. We're returning a bio right now
2544 * but you can call btrfs_io_bio for the appropriate container_of magic
2547 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
2552 bio
= bio_alloc_bioset(gfp_flags
, nr_vecs
, btrfs_bioset
);
2554 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
2555 while (!bio
&& (nr_vecs
/= 2)) {
2556 bio
= bio_alloc_bioset(gfp_flags
,
2557 nr_vecs
, btrfs_bioset
);
2563 bio
->bi_bdev
= bdev
;
2564 bio
->bi_sector
= first_sector
;
2569 struct bio
*btrfs_bio_clone(struct bio
*bio
, gfp_t gfp_mask
)
2571 return bio_clone_bioset(bio
, gfp_mask
, btrfs_bioset
);
2575 /* this also allocates from the btrfs_bioset */
2576 struct bio
*btrfs_io_bio_alloc(gfp_t gfp_mask
, unsigned int nr_iovecs
)
2578 return bio_alloc_bioset(gfp_mask
, nr_iovecs
, btrfs_bioset
);
2582 static int __must_check
submit_one_bio(int rw
, struct bio
*bio
,
2583 int mirror_num
, unsigned long bio_flags
)
2586 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2587 struct page
*page
= bvec
->bv_page
;
2588 struct extent_io_tree
*tree
= bio
->bi_private
;
2591 start
= page_offset(page
) + bvec
->bv_offset
;
2593 bio
->bi_private
= NULL
;
2597 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
2598 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
2599 mirror_num
, bio_flags
, start
);
2601 btrfsic_submit_bio(rw
, bio
);
2603 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
2609 static int merge_bio(int rw
, struct extent_io_tree
*tree
, struct page
*page
,
2610 unsigned long offset
, size_t size
, struct bio
*bio
,
2611 unsigned long bio_flags
)
2614 if (tree
->ops
&& tree
->ops
->merge_bio_hook
)
2615 ret
= tree
->ops
->merge_bio_hook(rw
, page
, offset
, size
, bio
,
2622 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
2623 struct page
*page
, sector_t sector
,
2624 size_t size
, unsigned long offset
,
2625 struct block_device
*bdev
,
2626 struct bio
**bio_ret
,
2627 unsigned long max_pages
,
2628 bio_end_io_t end_io_func
,
2630 unsigned long prev_bio_flags
,
2631 unsigned long bio_flags
)
2637 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
2638 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2639 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
2641 if (bio_ret
&& *bio_ret
) {
2644 contig
= bio
->bi_sector
== sector
;
2646 contig
= bio_end_sector(bio
) == sector
;
2648 if (prev_bio_flags
!= bio_flags
|| !contig
||
2649 merge_bio(rw
, tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2650 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2651 ret
= submit_one_bio(rw
, bio
, mirror_num
,
2660 if (this_compressed
)
2663 nr
= bio_get_nr_vecs(bdev
);
2665 bio
= btrfs_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
2669 bio_add_page(bio
, page
, page_size
, offset
);
2670 bio
->bi_end_io
= end_io_func
;
2671 bio
->bi_private
= tree
;
2676 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
2681 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2684 if (!PagePrivate(page
)) {
2685 SetPagePrivate(page
);
2686 page_cache_get(page
);
2687 set_page_private(page
, (unsigned long)eb
);
2689 WARN_ON(page
->private != (unsigned long)eb
);
2693 void set_page_extent_mapped(struct page
*page
)
2695 if (!PagePrivate(page
)) {
2696 SetPagePrivate(page
);
2697 page_cache_get(page
);
2698 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2703 * basic readpage implementation. Locked extent state structs are inserted
2704 * into the tree that are removed when the IO is done (by the end_io
2706 * XXX JDM: This needs looking at to ensure proper page locking
2708 static int __extent_read_full_page(struct extent_io_tree
*tree
,
2710 get_extent_t
*get_extent
,
2711 struct bio
**bio
, int mirror_num
,
2712 unsigned long *bio_flags
, int rw
)
2714 struct inode
*inode
= page
->mapping
->host
;
2715 u64 start
= page_offset(page
);
2716 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2720 u64 last_byte
= i_size_read(inode
);
2724 struct extent_map
*em
;
2725 struct block_device
*bdev
;
2726 struct btrfs_ordered_extent
*ordered
;
2729 size_t pg_offset
= 0;
2731 size_t disk_io_size
;
2732 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2733 unsigned long this_bio_flag
= 0;
2735 set_page_extent_mapped(page
);
2737 if (!PageUptodate(page
)) {
2738 if (cleancache_get_page(page
) == 0) {
2739 BUG_ON(blocksize
!= PAGE_SIZE
);
2746 lock_extent(tree
, start
, end
);
2747 ordered
= btrfs_lookup_ordered_extent(inode
, start
);
2750 unlock_extent(tree
, start
, end
);
2751 btrfs_start_ordered_extent(inode
, ordered
, 1);
2752 btrfs_put_ordered_extent(ordered
);
2755 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
2757 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
2760 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
2761 userpage
= kmap_atomic(page
);
2762 memset(userpage
+ zero_offset
, 0, iosize
);
2763 flush_dcache_page(page
);
2764 kunmap_atomic(userpage
);
2767 while (cur
<= end
) {
2768 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2770 if (cur
>= last_byte
) {
2772 struct extent_state
*cached
= NULL
;
2774 iosize
= PAGE_CACHE_SIZE
- pg_offset
;
2775 userpage
= kmap_atomic(page
);
2776 memset(userpage
+ pg_offset
, 0, iosize
);
2777 flush_dcache_page(page
);
2778 kunmap_atomic(userpage
);
2779 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2781 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2785 em
= get_extent(inode
, page
, pg_offset
, cur
,
2787 if (IS_ERR_OR_NULL(em
)) {
2789 unlock_extent(tree
, cur
, end
);
2792 extent_offset
= cur
- em
->start
;
2793 BUG_ON(extent_map_end(em
) <= cur
);
2796 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2797 this_bio_flag
= EXTENT_BIO_COMPRESSED
;
2798 extent_set_compress_type(&this_bio_flag
,
2802 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2803 cur_end
= min(extent_map_end(em
) - 1, end
);
2804 iosize
= ALIGN(iosize
, blocksize
);
2805 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2806 disk_io_size
= em
->block_len
;
2807 sector
= em
->block_start
>> 9;
2809 sector
= (em
->block_start
+ extent_offset
) >> 9;
2810 disk_io_size
= iosize
;
2813 block_start
= em
->block_start
;
2814 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2815 block_start
= EXTENT_MAP_HOLE
;
2816 free_extent_map(em
);
2819 /* we've found a hole, just zero and go on */
2820 if (block_start
== EXTENT_MAP_HOLE
) {
2822 struct extent_state
*cached
= NULL
;
2824 userpage
= kmap_atomic(page
);
2825 memset(userpage
+ pg_offset
, 0, iosize
);
2826 flush_dcache_page(page
);
2827 kunmap_atomic(userpage
);
2829 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2831 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2834 pg_offset
+= iosize
;
2837 /* the get_extent function already copied into the page */
2838 if (test_range_bit(tree
, cur
, cur_end
,
2839 EXTENT_UPTODATE
, 1, NULL
)) {
2840 check_page_uptodate(tree
, page
);
2841 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2843 pg_offset
+= iosize
;
2846 /* we have an inline extent but it didn't get marked up
2847 * to date. Error out
2849 if (block_start
== EXTENT_MAP_INLINE
) {
2851 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2853 pg_offset
+= iosize
;
2858 ret
= submit_extent_page(rw
, tree
, page
,
2859 sector
, disk_io_size
, pg_offset
,
2861 end_bio_extent_readpage
, mirror_num
,
2866 *bio_flags
= this_bio_flag
;
2869 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2872 pg_offset
+= iosize
;
2876 if (!PageError(page
))
2877 SetPageUptodate(page
);
2883 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2884 get_extent_t
*get_extent
, int mirror_num
)
2886 struct bio
*bio
= NULL
;
2887 unsigned long bio_flags
= 0;
2890 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
2893 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
2897 static noinline
void update_nr_written(struct page
*page
,
2898 struct writeback_control
*wbc
,
2899 unsigned long nr_written
)
2901 wbc
->nr_to_write
-= nr_written
;
2902 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
2903 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
2904 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
2908 * the writepage semantics are similar to regular writepage. extent
2909 * records are inserted to lock ranges in the tree, and as dirty areas
2910 * are found, they are marked writeback. Then the lock bits are removed
2911 * and the end_io handler clears the writeback ranges
2913 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
2916 struct inode
*inode
= page
->mapping
->host
;
2917 struct extent_page_data
*epd
= data
;
2918 struct extent_io_tree
*tree
= epd
->tree
;
2919 u64 start
= page_offset(page
);
2921 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2925 u64 last_byte
= i_size_read(inode
);
2929 struct extent_state
*cached_state
= NULL
;
2930 struct extent_map
*em
;
2931 struct block_device
*bdev
;
2934 size_t pg_offset
= 0;
2936 loff_t i_size
= i_size_read(inode
);
2937 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2943 unsigned long nr_written
= 0;
2944 bool fill_delalloc
= true;
2946 if (wbc
->sync_mode
== WB_SYNC_ALL
)
2947 write_flags
= WRITE_SYNC
;
2949 write_flags
= WRITE
;
2951 trace___extent_writepage(page
, inode
, wbc
);
2953 WARN_ON(!PageLocked(page
));
2955 ClearPageError(page
);
2957 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
2958 if (page
->index
> end_index
||
2959 (page
->index
== end_index
&& !pg_offset
)) {
2960 page
->mapping
->a_ops
->invalidatepage(page
, 0);
2965 if (page
->index
== end_index
) {
2968 userpage
= kmap_atomic(page
);
2969 memset(userpage
+ pg_offset
, 0,
2970 PAGE_CACHE_SIZE
- pg_offset
);
2971 kunmap_atomic(userpage
);
2972 flush_dcache_page(page
);
2976 set_page_extent_mapped(page
);
2978 if (!tree
->ops
|| !tree
->ops
->fill_delalloc
)
2979 fill_delalloc
= false;
2981 delalloc_start
= start
;
2984 if (!epd
->extent_locked
&& fill_delalloc
) {
2985 u64 delalloc_to_write
= 0;
2987 * make sure the wbc mapping index is at least updated
2990 update_nr_written(page
, wbc
, 0);
2992 while (delalloc_end
< page_end
) {
2993 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
2998 if (nr_delalloc
== 0) {
2999 delalloc_start
= delalloc_end
+ 1;
3002 ret
= tree
->ops
->fill_delalloc(inode
, page
,
3007 /* File system has been set read-only */
3013 * delalloc_end is already one less than the total
3014 * length, so we don't subtract one from
3017 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3020 delalloc_start
= delalloc_end
+ 1;
3022 if (wbc
->nr_to_write
< delalloc_to_write
) {
3025 if (delalloc_to_write
< thresh
* 2)
3026 thresh
= delalloc_to_write
;
3027 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3031 /* did the fill delalloc function already unlock and start
3037 * we've unlocked the page, so we can't update
3038 * the mapping's writeback index, just update
3041 wbc
->nr_to_write
-= nr_written
;
3045 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3046 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3049 /* Fixup worker will requeue */
3051 wbc
->pages_skipped
++;
3053 redirty_page_for_writepage(wbc
, page
);
3054 update_nr_written(page
, wbc
, nr_written
);
3062 * we don't want to touch the inode after unlocking the page,
3063 * so we update the mapping writeback index now
3065 update_nr_written(page
, wbc
, nr_written
+ 1);
3068 if (last_byte
<= start
) {
3069 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3070 tree
->ops
->writepage_end_io_hook(page
, start
,
3075 blocksize
= inode
->i_sb
->s_blocksize
;
3077 while (cur
<= end
) {
3078 if (cur
>= last_byte
) {
3079 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3080 tree
->ops
->writepage_end_io_hook(page
, cur
,
3084 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
3086 if (IS_ERR_OR_NULL(em
)) {
3091 extent_offset
= cur
- em
->start
;
3092 BUG_ON(extent_map_end(em
) <= cur
);
3094 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
3095 iosize
= ALIGN(iosize
, blocksize
);
3096 sector
= (em
->block_start
+ extent_offset
) >> 9;
3098 block_start
= em
->block_start
;
3099 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3100 free_extent_map(em
);
3104 * compressed and inline extents are written through other
3107 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3108 block_start
== EXTENT_MAP_INLINE
) {
3110 * end_io notification does not happen here for
3111 * compressed extents
3113 if (!compressed
&& tree
->ops
&&
3114 tree
->ops
->writepage_end_io_hook
)
3115 tree
->ops
->writepage_end_io_hook(page
, cur
,
3118 else if (compressed
) {
3119 /* we don't want to end_page_writeback on
3120 * a compressed extent. this happens
3127 pg_offset
+= iosize
;
3130 /* leave this out until we have a page_mkwrite call */
3131 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
3132 EXTENT_DIRTY
, 0, NULL
)) {
3134 pg_offset
+= iosize
;
3138 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
3139 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
3147 unsigned long max_nr
= end_index
+ 1;
3149 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3150 if (!PageWriteback(page
)) {
3151 printk(KERN_ERR
"btrfs warning page %lu not "
3152 "writeback, cur %llu end %llu\n",
3153 page
->index
, (unsigned long long)cur
,
3154 (unsigned long long)end
);
3157 ret
= submit_extent_page(write_flags
, tree
, page
,
3158 sector
, iosize
, pg_offset
,
3159 bdev
, &epd
->bio
, max_nr
,
3160 end_bio_extent_writepage
,
3166 pg_offset
+= iosize
;
3171 /* make sure the mapping tag for page dirty gets cleared */
3172 set_page_writeback(page
);
3173 end_page_writeback(page
);
3179 /* drop our reference on any cached states */
3180 free_extent_state(cached_state
);
3184 static int eb_wait(void *word
)
3190 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3192 wait_on_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
, eb_wait
,
3193 TASK_UNINTERRUPTIBLE
);
3196 static int lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3197 struct btrfs_fs_info
*fs_info
,
3198 struct extent_page_data
*epd
)
3200 unsigned long i
, num_pages
;
3204 if (!btrfs_try_tree_write_lock(eb
)) {
3206 flush_write_bio(epd
);
3207 btrfs_tree_lock(eb
);
3210 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3211 btrfs_tree_unlock(eb
);
3215 flush_write_bio(epd
);
3219 wait_on_extent_buffer_writeback(eb
);
3220 btrfs_tree_lock(eb
);
3221 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3223 btrfs_tree_unlock(eb
);
3228 * We need to do this to prevent races in people who check if the eb is
3229 * under IO since we can end up having no IO bits set for a short period
3232 spin_lock(&eb
->refs_lock
);
3233 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3234 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3235 spin_unlock(&eb
->refs_lock
);
3236 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3237 __percpu_counter_add(&fs_info
->dirty_metadata_bytes
,
3239 fs_info
->dirty_metadata_batch
);
3242 spin_unlock(&eb
->refs_lock
);
3245 btrfs_tree_unlock(eb
);
3250 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3251 for (i
= 0; i
< num_pages
; i
++) {
3252 struct page
*p
= extent_buffer_page(eb
, i
);
3254 if (!trylock_page(p
)) {
3256 flush_write_bio(epd
);
3266 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3268 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3269 smp_mb__after_clear_bit();
3270 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3273 static void end_bio_extent_buffer_writepage(struct bio
*bio
, int err
)
3275 int uptodate
= err
== 0;
3276 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
3277 struct extent_buffer
*eb
;
3281 struct page
*page
= bvec
->bv_page
;
3284 eb
= (struct extent_buffer
*)page
->private;
3286 done
= atomic_dec_and_test(&eb
->io_pages
);
3288 if (!uptodate
|| test_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
)) {
3289 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3290 ClearPageUptodate(page
);
3294 end_page_writeback(page
);
3299 end_extent_buffer_writeback(eb
);
3300 } while (bvec
>= bio
->bi_io_vec
);
3306 static int write_one_eb(struct extent_buffer
*eb
,
3307 struct btrfs_fs_info
*fs_info
,
3308 struct writeback_control
*wbc
,
3309 struct extent_page_data
*epd
)
3311 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3312 u64 offset
= eb
->start
;
3313 unsigned long i
, num_pages
;
3314 unsigned long bio_flags
= 0;
3315 int rw
= (epd
->sync_io
? WRITE_SYNC
: WRITE
) | REQ_META
;
3318 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3319 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3320 atomic_set(&eb
->io_pages
, num_pages
);
3321 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3322 bio_flags
= EXTENT_BIO_TREE_LOG
;
3324 for (i
= 0; i
< num_pages
; i
++) {
3325 struct page
*p
= extent_buffer_page(eb
, i
);
3327 clear_page_dirty_for_io(p
);
3328 set_page_writeback(p
);
3329 ret
= submit_extent_page(rw
, eb
->tree
, p
, offset
>> 9,
3330 PAGE_CACHE_SIZE
, 0, bdev
, &epd
->bio
,
3331 -1, end_bio_extent_buffer_writepage
,
3332 0, epd
->bio_flags
, bio_flags
);
3333 epd
->bio_flags
= bio_flags
;
3335 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3337 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3338 end_extent_buffer_writeback(eb
);
3342 offset
+= PAGE_CACHE_SIZE
;
3343 update_nr_written(p
, wbc
, 1);
3347 if (unlikely(ret
)) {
3348 for (; i
< num_pages
; i
++) {
3349 struct page
*p
= extent_buffer_page(eb
, i
);
3357 int btree_write_cache_pages(struct address_space
*mapping
,
3358 struct writeback_control
*wbc
)
3360 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3361 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3362 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3363 struct extent_page_data epd
= {
3367 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3372 int nr_to_write_done
= 0;
3373 struct pagevec pvec
;
3376 pgoff_t end
; /* Inclusive */
3380 pagevec_init(&pvec
, 0);
3381 if (wbc
->range_cyclic
) {
3382 index
= mapping
->writeback_index
; /* Start from prev offset */
3385 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3386 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3389 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3390 tag
= PAGECACHE_TAG_TOWRITE
;
3392 tag
= PAGECACHE_TAG_DIRTY
;
3394 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3395 tag_pages_for_writeback(mapping
, index
, end
);
3396 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3397 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3398 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3402 for (i
= 0; i
< nr_pages
; i
++) {
3403 struct page
*page
= pvec
.pages
[i
];
3405 if (!PagePrivate(page
))
3408 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3413 spin_lock(&mapping
->private_lock
);
3414 if (!PagePrivate(page
)) {
3415 spin_unlock(&mapping
->private_lock
);
3419 eb
= (struct extent_buffer
*)page
->private;
3422 * Shouldn't happen and normally this would be a BUG_ON
3423 * but no sense in crashing the users box for something
3424 * we can survive anyway.
3427 spin_unlock(&mapping
->private_lock
);
3432 if (eb
== prev_eb
) {
3433 spin_unlock(&mapping
->private_lock
);
3437 ret
= atomic_inc_not_zero(&eb
->refs
);
3438 spin_unlock(&mapping
->private_lock
);
3443 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3445 free_extent_buffer(eb
);
3449 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3452 free_extent_buffer(eb
);
3455 free_extent_buffer(eb
);
3458 * the filesystem may choose to bump up nr_to_write.
3459 * We have to make sure to honor the new nr_to_write
3462 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3464 pagevec_release(&pvec
);
3467 if (!scanned
&& !done
) {
3469 * We hit the last page and there is more work to be done: wrap
3470 * back to the start of the file
3476 flush_write_bio(&epd
);
3481 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3482 * @mapping: address space structure to write
3483 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3484 * @writepage: function called for each page
3485 * @data: data passed to writepage function
3487 * If a page is already under I/O, write_cache_pages() skips it, even
3488 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3489 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3490 * and msync() need to guarantee that all the data which was dirty at the time
3491 * the call was made get new I/O started against them. If wbc->sync_mode is
3492 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3493 * existing IO to complete.
3495 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
3496 struct address_space
*mapping
,
3497 struct writeback_control
*wbc
,
3498 writepage_t writepage
, void *data
,
3499 void (*flush_fn
)(void *))
3501 struct inode
*inode
= mapping
->host
;
3504 int nr_to_write_done
= 0;
3505 struct pagevec pvec
;
3508 pgoff_t end
; /* Inclusive */
3513 * We have to hold onto the inode so that ordered extents can do their
3514 * work when the IO finishes. The alternative to this is failing to add
3515 * an ordered extent if the igrab() fails there and that is a huge pain
3516 * to deal with, so instead just hold onto the inode throughout the
3517 * writepages operation. If it fails here we are freeing up the inode
3518 * anyway and we'd rather not waste our time writing out stuff that is
3519 * going to be truncated anyway.
3524 pagevec_init(&pvec
, 0);
3525 if (wbc
->range_cyclic
) {
3526 index
= mapping
->writeback_index
; /* Start from prev offset */
3529 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3530 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3533 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3534 tag
= PAGECACHE_TAG_TOWRITE
;
3536 tag
= PAGECACHE_TAG_DIRTY
;
3538 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3539 tag_pages_for_writeback(mapping
, index
, end
);
3540 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3541 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3542 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3546 for (i
= 0; i
< nr_pages
; i
++) {
3547 struct page
*page
= pvec
.pages
[i
];
3550 * At this point we hold neither mapping->tree_lock nor
3551 * lock on the page itself: the page may be truncated or
3552 * invalidated (changing page->mapping to NULL), or even
3553 * swizzled back from swapper_space to tmpfs file
3556 if (!trylock_page(page
)) {
3561 if (unlikely(page
->mapping
!= mapping
)) {
3566 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3572 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
3573 if (PageWriteback(page
))
3575 wait_on_page_writeback(page
);
3578 if (PageWriteback(page
) ||
3579 !clear_page_dirty_for_io(page
)) {
3584 ret
= (*writepage
)(page
, wbc
, data
);
3586 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
3594 * the filesystem may choose to bump up nr_to_write.
3595 * We have to make sure to honor the new nr_to_write
3598 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3600 pagevec_release(&pvec
);
3603 if (!scanned
&& !done
) {
3605 * We hit the last page and there is more work to be done: wrap
3606 * back to the start of the file
3612 btrfs_add_delayed_iput(inode
);
3616 static void flush_epd_write_bio(struct extent_page_data
*epd
)
3625 ret
= submit_one_bio(rw
, epd
->bio
, 0, epd
->bio_flags
);
3626 BUG_ON(ret
< 0); /* -ENOMEM */
3631 static noinline
void flush_write_bio(void *data
)
3633 struct extent_page_data
*epd
= data
;
3634 flush_epd_write_bio(epd
);
3637 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3638 get_extent_t
*get_extent
,
3639 struct writeback_control
*wbc
)
3642 struct extent_page_data epd
= {
3645 .get_extent
= get_extent
,
3647 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3651 ret
= __extent_writepage(page
, wbc
, &epd
);
3653 flush_epd_write_bio(&epd
);
3657 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
3658 u64 start
, u64 end
, get_extent_t
*get_extent
,
3662 struct address_space
*mapping
= inode
->i_mapping
;
3664 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
3667 struct extent_page_data epd
= {
3670 .get_extent
= get_extent
,
3672 .sync_io
= mode
== WB_SYNC_ALL
,
3675 struct writeback_control wbc_writepages
= {
3677 .nr_to_write
= nr_pages
* 2,
3678 .range_start
= start
,
3679 .range_end
= end
+ 1,
3682 while (start
<= end
) {
3683 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
3684 if (clear_page_dirty_for_io(page
))
3685 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
3687 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3688 tree
->ops
->writepage_end_io_hook(page
, start
,
3689 start
+ PAGE_CACHE_SIZE
- 1,
3693 page_cache_release(page
);
3694 start
+= PAGE_CACHE_SIZE
;
3697 flush_epd_write_bio(&epd
);
3701 int extent_writepages(struct extent_io_tree
*tree
,
3702 struct address_space
*mapping
,
3703 get_extent_t
*get_extent
,
3704 struct writeback_control
*wbc
)
3707 struct extent_page_data epd
= {
3710 .get_extent
= get_extent
,
3712 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3716 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
3717 __extent_writepage
, &epd
,
3719 flush_epd_write_bio(&epd
);
3723 int extent_readpages(struct extent_io_tree
*tree
,
3724 struct address_space
*mapping
,
3725 struct list_head
*pages
, unsigned nr_pages
,
3726 get_extent_t get_extent
)
3728 struct bio
*bio
= NULL
;
3730 unsigned long bio_flags
= 0;
3731 struct page
*pagepool
[16];
3736 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
3737 page
= list_entry(pages
->prev
, struct page
, lru
);
3739 prefetchw(&page
->flags
);
3740 list_del(&page
->lru
);
3741 if (add_to_page_cache_lru(page
, mapping
,
3742 page
->index
, GFP_NOFS
)) {
3743 page_cache_release(page
);
3747 pagepool
[nr
++] = page
;
3748 if (nr
< ARRAY_SIZE(pagepool
))
3750 for (i
= 0; i
< nr
; i
++) {
3751 __extent_read_full_page(tree
, pagepool
[i
], get_extent
,
3752 &bio
, 0, &bio_flags
, READ
);
3753 page_cache_release(pagepool
[i
]);
3757 for (i
= 0; i
< nr
; i
++) {
3758 __extent_read_full_page(tree
, pagepool
[i
], get_extent
,
3759 &bio
, 0, &bio_flags
, READ
);
3760 page_cache_release(pagepool
[i
]);
3763 BUG_ON(!list_empty(pages
));
3765 return submit_one_bio(READ
, bio
, 0, bio_flags
);
3770 * basic invalidatepage code, this waits on any locked or writeback
3771 * ranges corresponding to the page, and then deletes any extent state
3772 * records from the tree
3774 int extent_invalidatepage(struct extent_io_tree
*tree
,
3775 struct page
*page
, unsigned long offset
)
3777 struct extent_state
*cached_state
= NULL
;
3778 u64 start
= page_offset(page
);
3779 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3780 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
3782 start
+= ALIGN(offset
, blocksize
);
3786 lock_extent_bits(tree
, start
, end
, 0, &cached_state
);
3787 wait_on_page_writeback(page
);
3788 clear_extent_bit(tree
, start
, end
,
3789 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
3790 EXTENT_DO_ACCOUNTING
,
3791 1, 1, &cached_state
, GFP_NOFS
);
3796 * a helper for releasepage, this tests for areas of the page that
3797 * are locked or under IO and drops the related state bits if it is safe
3800 static int try_release_extent_state(struct extent_map_tree
*map
,
3801 struct extent_io_tree
*tree
,
3802 struct page
*page
, gfp_t mask
)
3804 u64 start
= page_offset(page
);
3805 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3808 if (test_range_bit(tree
, start
, end
,
3809 EXTENT_IOBITS
, 0, NULL
))
3812 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
3815 * at this point we can safely clear everything except the
3816 * locked bit and the nodatasum bit
3818 ret
= clear_extent_bit(tree
, start
, end
,
3819 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
3822 /* if clear_extent_bit failed for enomem reasons,
3823 * we can't allow the release to continue.
3834 * a helper for releasepage. As long as there are no locked extents
3835 * in the range corresponding to the page, both state records and extent
3836 * map records are removed
3838 int try_release_extent_mapping(struct extent_map_tree
*map
,
3839 struct extent_io_tree
*tree
, struct page
*page
,
3842 struct extent_map
*em
;
3843 u64 start
= page_offset(page
);
3844 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3846 if ((mask
& __GFP_WAIT
) &&
3847 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
3849 while (start
<= end
) {
3850 len
= end
- start
+ 1;
3851 write_lock(&map
->lock
);
3852 em
= lookup_extent_mapping(map
, start
, len
);
3854 write_unlock(&map
->lock
);
3857 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
3858 em
->start
!= start
) {
3859 write_unlock(&map
->lock
);
3860 free_extent_map(em
);
3863 if (!test_range_bit(tree
, em
->start
,
3864 extent_map_end(em
) - 1,
3865 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
3867 remove_extent_mapping(map
, em
);
3868 /* once for the rb tree */
3869 free_extent_map(em
);
3871 start
= extent_map_end(em
);
3872 write_unlock(&map
->lock
);
3875 free_extent_map(em
);
3878 return try_release_extent_state(map
, tree
, page
, mask
);
3882 * helper function for fiemap, which doesn't want to see any holes.
3883 * This maps until we find something past 'last'
3885 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
3888 get_extent_t
*get_extent
)
3890 u64 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
3891 struct extent_map
*em
;
3898 len
= last
- offset
;
3901 len
= ALIGN(len
, sectorsize
);
3902 em
= get_extent(inode
, NULL
, 0, offset
, len
, 0);
3903 if (IS_ERR_OR_NULL(em
))
3906 /* if this isn't a hole return it */
3907 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
3908 em
->block_start
!= EXTENT_MAP_HOLE
) {
3912 /* this is a hole, advance to the next extent */
3913 offset
= extent_map_end(em
);
3914 free_extent_map(em
);
3921 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
3922 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
3926 u64 max
= start
+ len
;
3930 u64 last_for_get_extent
= 0;
3932 u64 isize
= i_size_read(inode
);
3933 struct btrfs_key found_key
;
3934 struct extent_map
*em
= NULL
;
3935 struct extent_state
*cached_state
= NULL
;
3936 struct btrfs_path
*path
;
3937 struct btrfs_file_extent_item
*item
;
3942 unsigned long emflags
;
3947 path
= btrfs_alloc_path();
3950 path
->leave_spinning
= 1;
3952 start
= ALIGN(start
, BTRFS_I(inode
)->root
->sectorsize
);
3953 len
= ALIGN(len
, BTRFS_I(inode
)->root
->sectorsize
);
3956 * lookup the last file extent. We're not using i_size here
3957 * because there might be preallocation past i_size
3959 ret
= btrfs_lookup_file_extent(NULL
, BTRFS_I(inode
)->root
,
3960 path
, btrfs_ino(inode
), -1, 0);
3962 btrfs_free_path(path
);
3967 item
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3968 struct btrfs_file_extent_item
);
3969 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
3970 found_type
= btrfs_key_type(&found_key
);
3972 /* No extents, but there might be delalloc bits */
3973 if (found_key
.objectid
!= btrfs_ino(inode
) ||
3974 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
3975 /* have to trust i_size as the end */
3977 last_for_get_extent
= isize
;
3980 * remember the start of the last extent. There are a
3981 * bunch of different factors that go into the length of the
3982 * extent, so its much less complex to remember where it started
3984 last
= found_key
.offset
;
3985 last_for_get_extent
= last
+ 1;
3987 btrfs_free_path(path
);
3990 * we might have some extents allocated but more delalloc past those
3991 * extents. so, we trust isize unless the start of the last extent is
3996 last_for_get_extent
= isize
;
3999 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1, 0,
4002 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4012 u64 offset_in_extent
;
4014 /* break if the extent we found is outside the range */
4015 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4019 * get_extent may return an extent that starts before our
4020 * requested range. We have to make sure the ranges
4021 * we return to fiemap always move forward and don't
4022 * overlap, so adjust the offsets here
4024 em_start
= max(em
->start
, off
);
4027 * record the offset from the start of the extent
4028 * for adjusting the disk offset below
4030 offset_in_extent
= em_start
- em
->start
;
4031 em_end
= extent_map_end(em
);
4032 em_len
= em_end
- em_start
;
4033 emflags
= em
->flags
;
4038 * bump off for our next call to get_extent
4040 off
= extent_map_end(em
);
4044 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4046 flags
|= FIEMAP_EXTENT_LAST
;
4047 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4048 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4049 FIEMAP_EXTENT_NOT_ALIGNED
);
4050 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4051 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4052 FIEMAP_EXTENT_UNKNOWN
);
4054 disko
= em
->block_start
+ offset_in_extent
;
4056 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4057 flags
|= FIEMAP_EXTENT_ENCODED
;
4059 free_extent_map(em
);
4061 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4062 (last
== (u64
)-1 && isize
<= em_end
)) {
4063 flags
|= FIEMAP_EXTENT_LAST
;
4067 /* now scan forward to see if this is really the last extent. */
4068 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4075 flags
|= FIEMAP_EXTENT_LAST
;
4078 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
4084 free_extent_map(em
);
4086 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4087 &cached_state
, GFP_NOFS
);
4091 static void __free_extent_buffer(struct extent_buffer
*eb
)
4093 btrfs_leak_debug_del(&eb
->leak_list
);
4094 kmem_cache_free(extent_buffer_cache
, eb
);
4097 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
4102 struct extent_buffer
*eb
= NULL
;
4104 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
4111 rwlock_init(&eb
->lock
);
4112 atomic_set(&eb
->write_locks
, 0);
4113 atomic_set(&eb
->read_locks
, 0);
4114 atomic_set(&eb
->blocking_readers
, 0);
4115 atomic_set(&eb
->blocking_writers
, 0);
4116 atomic_set(&eb
->spinning_readers
, 0);
4117 atomic_set(&eb
->spinning_writers
, 0);
4118 eb
->lock_nested
= 0;
4119 init_waitqueue_head(&eb
->write_lock_wq
);
4120 init_waitqueue_head(&eb
->read_lock_wq
);
4122 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4124 spin_lock_init(&eb
->refs_lock
);
4125 atomic_set(&eb
->refs
, 1);
4126 atomic_set(&eb
->io_pages
, 0);
4129 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4131 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4132 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4133 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4138 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4142 struct extent_buffer
*new;
4143 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4145 new = __alloc_extent_buffer(NULL
, src
->start
, src
->len
, GFP_ATOMIC
);
4149 for (i
= 0; i
< num_pages
; i
++) {
4150 p
= alloc_page(GFP_ATOMIC
);
4152 attach_extent_buffer_page(new, p
);
4153 WARN_ON(PageDirty(p
));
4158 copy_extent_buffer(new, src
, 0, 0, src
->len
);
4159 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4160 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4165 struct extent_buffer
*alloc_dummy_extent_buffer(u64 start
, unsigned long len
)
4167 struct extent_buffer
*eb
;
4168 unsigned long num_pages
= num_extent_pages(0, len
);
4171 eb
= __alloc_extent_buffer(NULL
, start
, len
, GFP_ATOMIC
);
4175 for (i
= 0; i
< num_pages
; i
++) {
4176 eb
->pages
[i
] = alloc_page(GFP_ATOMIC
);
4180 set_extent_buffer_uptodate(eb
);
4181 btrfs_set_header_nritems(eb
, 0);
4182 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4187 __free_page(eb
->pages
[i
- 1]);
4188 __free_extent_buffer(eb
);
4192 static int extent_buffer_under_io(struct extent_buffer
*eb
)
4194 return (atomic_read(&eb
->io_pages
) ||
4195 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4196 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4200 * Helper for releasing extent buffer page.
4202 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
,
4203 unsigned long start_idx
)
4205 unsigned long index
;
4206 unsigned long num_pages
;
4208 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4210 BUG_ON(extent_buffer_under_io(eb
));
4212 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4213 index
= start_idx
+ num_pages
;
4214 if (start_idx
>= index
)
4219 page
= extent_buffer_page(eb
, index
);
4220 if (page
&& mapped
) {
4221 spin_lock(&page
->mapping
->private_lock
);
4223 * We do this since we'll remove the pages after we've
4224 * removed the eb from the radix tree, so we could race
4225 * and have this page now attached to the new eb. So
4226 * only clear page_private if it's still connected to
4229 if (PagePrivate(page
) &&
4230 page
->private == (unsigned long)eb
) {
4231 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4232 BUG_ON(PageDirty(page
));
4233 BUG_ON(PageWriteback(page
));
4235 * We need to make sure we haven't be attached
4238 ClearPagePrivate(page
);
4239 set_page_private(page
, 0);
4240 /* One for the page private */
4241 page_cache_release(page
);
4243 spin_unlock(&page
->mapping
->private_lock
);
4247 /* One for when we alloced the page */
4248 page_cache_release(page
);
4250 } while (index
!= start_idx
);
4254 * Helper for releasing the extent buffer.
4256 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4258 btrfs_release_extent_buffer_page(eb
, 0);
4259 __free_extent_buffer(eb
);
4262 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4265 /* the ref bit is tricky. We have to make sure it is set
4266 * if we have the buffer dirty. Otherwise the
4267 * code to free a buffer can end up dropping a dirty
4270 * Once the ref bit is set, it won't go away while the
4271 * buffer is dirty or in writeback, and it also won't
4272 * go away while we have the reference count on the
4275 * We can't just set the ref bit without bumping the
4276 * ref on the eb because free_extent_buffer might
4277 * see the ref bit and try to clear it. If this happens
4278 * free_extent_buffer might end up dropping our original
4279 * ref by mistake and freeing the page before we are able
4280 * to add one more ref.
4282 * So bump the ref count first, then set the bit. If someone
4283 * beat us to it, drop the ref we added.
4285 refs
= atomic_read(&eb
->refs
);
4286 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4289 spin_lock(&eb
->refs_lock
);
4290 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4291 atomic_inc(&eb
->refs
);
4292 spin_unlock(&eb
->refs_lock
);
4295 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
)
4297 unsigned long num_pages
, i
;
4299 check_buffer_tree_ref(eb
);
4301 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4302 for (i
= 0; i
< num_pages
; i
++) {
4303 struct page
*p
= extent_buffer_page(eb
, i
);
4304 mark_page_accessed(p
);
4308 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
4309 u64 start
, unsigned long len
)
4311 unsigned long num_pages
= num_extent_pages(start
, len
);
4313 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
4314 struct extent_buffer
*eb
;
4315 struct extent_buffer
*exists
= NULL
;
4317 struct address_space
*mapping
= tree
->mapping
;
4322 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4323 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4325 mark_extent_buffer_accessed(eb
);
4330 eb
= __alloc_extent_buffer(tree
, start
, len
, GFP_NOFS
);
4334 for (i
= 0; i
< num_pages
; i
++, index
++) {
4335 p
= find_or_create_page(mapping
, index
, GFP_NOFS
);
4339 spin_lock(&mapping
->private_lock
);
4340 if (PagePrivate(p
)) {
4342 * We could have already allocated an eb for this page
4343 * and attached one so lets see if we can get a ref on
4344 * the existing eb, and if we can we know it's good and
4345 * we can just return that one, else we know we can just
4346 * overwrite page->private.
4348 exists
= (struct extent_buffer
*)p
->private;
4349 if (atomic_inc_not_zero(&exists
->refs
)) {
4350 spin_unlock(&mapping
->private_lock
);
4352 page_cache_release(p
);
4353 mark_extent_buffer_accessed(exists
);
4358 * Do this so attach doesn't complain and we need to
4359 * drop the ref the old guy had.
4361 ClearPagePrivate(p
);
4362 WARN_ON(PageDirty(p
));
4363 page_cache_release(p
);
4365 attach_extent_buffer_page(eb
, p
);
4366 spin_unlock(&mapping
->private_lock
);
4367 WARN_ON(PageDirty(p
));
4368 mark_page_accessed(p
);
4370 if (!PageUptodate(p
))
4374 * see below about how we avoid a nasty race with release page
4375 * and why we unlock later
4379 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4381 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
4385 spin_lock(&tree
->buffer_lock
);
4386 ret
= radix_tree_insert(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
, eb
);
4387 if (ret
== -EEXIST
) {
4388 exists
= radix_tree_lookup(&tree
->buffer
,
4389 start
>> PAGE_CACHE_SHIFT
);
4390 if (!atomic_inc_not_zero(&exists
->refs
)) {
4391 spin_unlock(&tree
->buffer_lock
);
4392 radix_tree_preload_end();
4396 spin_unlock(&tree
->buffer_lock
);
4397 radix_tree_preload_end();
4398 mark_extent_buffer_accessed(exists
);
4401 /* add one reference for the tree */
4402 check_buffer_tree_ref(eb
);
4403 spin_unlock(&tree
->buffer_lock
);
4404 radix_tree_preload_end();
4407 * there is a race where release page may have
4408 * tried to find this extent buffer in the radix
4409 * but failed. It will tell the VM it is safe to
4410 * reclaim the, and it will clear the page private bit.
4411 * We must make sure to set the page private bit properly
4412 * after the extent buffer is in the radix tree so
4413 * it doesn't get lost
4415 SetPageChecked(eb
->pages
[0]);
4416 for (i
= 1; i
< num_pages
; i
++) {
4417 p
= extent_buffer_page(eb
, i
);
4418 ClearPageChecked(p
);
4421 unlock_page(eb
->pages
[0]);
4425 for (i
= 0; i
< num_pages
; i
++) {
4427 unlock_page(eb
->pages
[i
]);
4430 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
4431 btrfs_release_extent_buffer(eb
);
4435 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
4436 u64 start
, unsigned long len
)
4438 struct extent_buffer
*eb
;
4441 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4442 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4444 mark_extent_buffer_accessed(eb
);
4452 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
4454 struct extent_buffer
*eb
=
4455 container_of(head
, struct extent_buffer
, rcu_head
);
4457 __free_extent_buffer(eb
);
4460 /* Expects to have eb->eb_lock already held */
4461 static int release_extent_buffer(struct extent_buffer
*eb
)
4463 WARN_ON(atomic_read(&eb
->refs
) == 0);
4464 if (atomic_dec_and_test(&eb
->refs
)) {
4465 if (test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
)) {
4466 spin_unlock(&eb
->refs_lock
);
4468 struct extent_io_tree
*tree
= eb
->tree
;
4470 spin_unlock(&eb
->refs_lock
);
4472 spin_lock(&tree
->buffer_lock
);
4473 radix_tree_delete(&tree
->buffer
,
4474 eb
->start
>> PAGE_CACHE_SHIFT
);
4475 spin_unlock(&tree
->buffer_lock
);
4478 /* Should be safe to release our pages at this point */
4479 btrfs_release_extent_buffer_page(eb
, 0);
4480 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
4483 spin_unlock(&eb
->refs_lock
);
4488 void free_extent_buffer(struct extent_buffer
*eb
)
4496 refs
= atomic_read(&eb
->refs
);
4499 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
4504 spin_lock(&eb
->refs_lock
);
4505 if (atomic_read(&eb
->refs
) == 2 &&
4506 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
4507 atomic_dec(&eb
->refs
);
4509 if (atomic_read(&eb
->refs
) == 2 &&
4510 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
4511 !extent_buffer_under_io(eb
) &&
4512 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4513 atomic_dec(&eb
->refs
);
4516 * I know this is terrible, but it's temporary until we stop tracking
4517 * the uptodate bits and such for the extent buffers.
4519 release_extent_buffer(eb
);
4522 void free_extent_buffer_stale(struct extent_buffer
*eb
)
4527 spin_lock(&eb
->refs_lock
);
4528 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
4530 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
4531 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4532 atomic_dec(&eb
->refs
);
4533 release_extent_buffer(eb
);
4536 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
4539 unsigned long num_pages
;
4542 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4544 for (i
= 0; i
< num_pages
; i
++) {
4545 page
= extent_buffer_page(eb
, i
);
4546 if (!PageDirty(page
))
4550 WARN_ON(!PagePrivate(page
));
4552 clear_page_dirty_for_io(page
);
4553 spin_lock_irq(&page
->mapping
->tree_lock
);
4554 if (!PageDirty(page
)) {
4555 radix_tree_tag_clear(&page
->mapping
->page_tree
,
4557 PAGECACHE_TAG_DIRTY
);
4559 spin_unlock_irq(&page
->mapping
->tree_lock
);
4560 ClearPageError(page
);
4563 WARN_ON(atomic_read(&eb
->refs
) == 0);
4566 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
4569 unsigned long num_pages
;
4572 check_buffer_tree_ref(eb
);
4574 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
4576 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4577 WARN_ON(atomic_read(&eb
->refs
) == 0);
4578 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
4580 for (i
= 0; i
< num_pages
; i
++)
4581 set_page_dirty(extent_buffer_page(eb
, i
));
4585 int clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
4589 unsigned long num_pages
;
4591 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4592 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4593 for (i
= 0; i
< num_pages
; i
++) {
4594 page
= extent_buffer_page(eb
, i
);
4596 ClearPageUptodate(page
);
4601 int set_extent_buffer_uptodate(struct extent_buffer
*eb
)
4605 unsigned long num_pages
;
4607 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4608 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4609 for (i
= 0; i
< num_pages
; i
++) {
4610 page
= extent_buffer_page(eb
, i
);
4611 SetPageUptodate(page
);
4616 int extent_buffer_uptodate(struct extent_buffer
*eb
)
4618 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4621 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
4622 struct extent_buffer
*eb
, u64 start
, int wait
,
4623 get_extent_t
*get_extent
, int mirror_num
)
4626 unsigned long start_i
;
4630 int locked_pages
= 0;
4631 int all_uptodate
= 1;
4632 unsigned long num_pages
;
4633 unsigned long num_reads
= 0;
4634 struct bio
*bio
= NULL
;
4635 unsigned long bio_flags
= 0;
4637 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
4641 WARN_ON(start
< eb
->start
);
4642 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
4643 (eb
->start
>> PAGE_CACHE_SHIFT
);
4648 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4649 for (i
= start_i
; i
< num_pages
; i
++) {
4650 page
= extent_buffer_page(eb
, i
);
4651 if (wait
== WAIT_NONE
) {
4652 if (!trylock_page(page
))
4658 if (!PageUptodate(page
)) {
4665 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4669 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
4670 eb
->read_mirror
= 0;
4671 atomic_set(&eb
->io_pages
, num_reads
);
4672 for (i
= start_i
; i
< num_pages
; i
++) {
4673 page
= extent_buffer_page(eb
, i
);
4674 if (!PageUptodate(page
)) {
4675 ClearPageError(page
);
4676 err
= __extent_read_full_page(tree
, page
,
4678 mirror_num
, &bio_flags
,
4688 err
= submit_one_bio(READ
| REQ_META
, bio
, mirror_num
,
4694 if (ret
|| wait
!= WAIT_COMPLETE
)
4697 for (i
= start_i
; i
< num_pages
; i
++) {
4698 page
= extent_buffer_page(eb
, i
);
4699 wait_on_page_locked(page
);
4700 if (!PageUptodate(page
))
4708 while (locked_pages
> 0) {
4709 page
= extent_buffer_page(eb
, i
);
4717 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
4718 unsigned long start
,
4725 char *dst
= (char *)dstv
;
4726 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4727 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4729 WARN_ON(start
> eb
->len
);
4730 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4732 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4735 page
= extent_buffer_page(eb
, i
);
4737 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4738 kaddr
= page_address(page
);
4739 memcpy(dst
, kaddr
+ offset
, cur
);
4748 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
4749 unsigned long min_len
, char **map
,
4750 unsigned long *map_start
,
4751 unsigned long *map_len
)
4753 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
4756 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4757 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4758 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
4765 offset
= start_offset
;
4769 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
4772 if (start
+ min_len
> eb
->len
) {
4773 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
4774 "wanted %lu %lu\n", (unsigned long long)eb
->start
,
4775 eb
->len
, start
, min_len
);
4779 p
= extent_buffer_page(eb
, i
);
4780 kaddr
= page_address(p
);
4781 *map
= kaddr
+ offset
;
4782 *map_len
= PAGE_CACHE_SIZE
- offset
;
4786 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
4787 unsigned long start
,
4794 char *ptr
= (char *)ptrv
;
4795 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4796 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4799 WARN_ON(start
> eb
->len
);
4800 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4802 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4805 page
= extent_buffer_page(eb
, i
);
4807 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4809 kaddr
= page_address(page
);
4810 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
4822 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
4823 unsigned long start
, unsigned long len
)
4829 char *src
= (char *)srcv
;
4830 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4831 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4833 WARN_ON(start
> eb
->len
);
4834 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4836 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4839 page
= extent_buffer_page(eb
, i
);
4840 WARN_ON(!PageUptodate(page
));
4842 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
4843 kaddr
= page_address(page
);
4844 memcpy(kaddr
+ offset
, src
, cur
);
4853 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
4854 unsigned long start
, unsigned long len
)
4860 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4861 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4863 WARN_ON(start
> eb
->len
);
4864 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4866 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4869 page
= extent_buffer_page(eb
, i
);
4870 WARN_ON(!PageUptodate(page
));
4872 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
4873 kaddr
= page_address(page
);
4874 memset(kaddr
+ offset
, c
, cur
);
4882 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
4883 unsigned long dst_offset
, unsigned long src_offset
,
4886 u64 dst_len
= dst
->len
;
4891 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4892 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
4894 WARN_ON(src
->len
!= dst_len
);
4896 offset
= (start_offset
+ dst_offset
) &
4897 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4900 page
= extent_buffer_page(dst
, i
);
4901 WARN_ON(!PageUptodate(page
));
4903 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
4905 kaddr
= page_address(page
);
4906 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
4915 static void move_pages(struct page
*dst_page
, struct page
*src_page
,
4916 unsigned long dst_off
, unsigned long src_off
,
4919 char *dst_kaddr
= page_address(dst_page
);
4920 if (dst_page
== src_page
) {
4921 memmove(dst_kaddr
+ dst_off
, dst_kaddr
+ src_off
, len
);
4923 char *src_kaddr
= page_address(src_page
);
4924 char *p
= dst_kaddr
+ dst_off
+ len
;
4925 char *s
= src_kaddr
+ src_off
+ len
;
4932 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
4934 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
4935 return distance
< len
;
4938 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
4939 unsigned long dst_off
, unsigned long src_off
,
4942 char *dst_kaddr
= page_address(dst_page
);
4944 int must_memmove
= 0;
4946 if (dst_page
!= src_page
) {
4947 src_kaddr
= page_address(src_page
);
4949 src_kaddr
= dst_kaddr
;
4950 if (areas_overlap(src_off
, dst_off
, len
))
4955 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
4957 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
4960 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
4961 unsigned long src_offset
, unsigned long len
)
4964 size_t dst_off_in_page
;
4965 size_t src_off_in_page
;
4966 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4967 unsigned long dst_i
;
4968 unsigned long src_i
;
4970 if (src_offset
+ len
> dst
->len
) {
4971 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
4972 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
4975 if (dst_offset
+ len
> dst
->len
) {
4976 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
4977 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
4982 dst_off_in_page
= (start_offset
+ dst_offset
) &
4983 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4984 src_off_in_page
= (start_offset
+ src_offset
) &
4985 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4987 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
4988 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
4990 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
4992 cur
= min_t(unsigned long, cur
,
4993 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
4995 copy_pages(extent_buffer_page(dst
, dst_i
),
4996 extent_buffer_page(dst
, src_i
),
4997 dst_off_in_page
, src_off_in_page
, cur
);
5005 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5006 unsigned long src_offset
, unsigned long len
)
5009 size_t dst_off_in_page
;
5010 size_t src_off_in_page
;
5011 unsigned long dst_end
= dst_offset
+ len
- 1;
5012 unsigned long src_end
= src_offset
+ len
- 1;
5013 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5014 unsigned long dst_i
;
5015 unsigned long src_i
;
5017 if (src_offset
+ len
> dst
->len
) {
5018 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5019 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
5022 if (dst_offset
+ len
> dst
->len
) {
5023 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5024 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
5027 if (dst_offset
< src_offset
) {
5028 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5032 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
5033 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
5035 dst_off_in_page
= (start_offset
+ dst_end
) &
5036 ((unsigned long)PAGE_CACHE_SIZE
- 1);
5037 src_off_in_page
= (start_offset
+ src_end
) &
5038 ((unsigned long)PAGE_CACHE_SIZE
- 1);
5040 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5041 cur
= min(cur
, dst_off_in_page
+ 1);
5042 move_pages(extent_buffer_page(dst
, dst_i
),
5043 extent_buffer_page(dst
, src_i
),
5044 dst_off_in_page
- cur
+ 1,
5045 src_off_in_page
- cur
+ 1, cur
);
5053 int try_release_extent_buffer(struct page
*page
)
5055 struct extent_buffer
*eb
;
5058 * We need to make sure noboody is attaching this page to an eb right
5061 spin_lock(&page
->mapping
->private_lock
);
5062 if (!PagePrivate(page
)) {
5063 spin_unlock(&page
->mapping
->private_lock
);
5067 eb
= (struct extent_buffer
*)page
->private;
5071 * This is a little awful but should be ok, we need to make sure that
5072 * the eb doesn't disappear out from under us while we're looking at
5075 spin_lock(&eb
->refs_lock
);
5076 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
5077 spin_unlock(&eb
->refs_lock
);
5078 spin_unlock(&page
->mapping
->private_lock
);
5081 spin_unlock(&page
->mapping
->private_lock
);
5084 * If tree ref isn't set then we know the ref on this eb is a real ref,
5085 * so just return, this page will likely be freed soon anyway.
5087 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
5088 spin_unlock(&eb
->refs_lock
);
5092 return release_extent_buffer(eb
);