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
;
27 #ifdef CONFIG_BTRFS_DEBUG
28 static LIST_HEAD(buffers
);
29 static LIST_HEAD(states
);
31 static DEFINE_SPINLOCK(leak_lock
);
34 void btrfs_leak_debug_add(struct list_head
*new, struct list_head
*head
)
38 spin_lock_irqsave(&leak_lock
, flags
);
40 spin_unlock_irqrestore(&leak_lock
, flags
);
44 void btrfs_leak_debug_del(struct list_head
*entry
)
48 spin_lock_irqsave(&leak_lock
, flags
);
50 spin_unlock_irqrestore(&leak_lock
, flags
);
54 void btrfs_leak_debug_check(void)
56 struct extent_state
*state
;
57 struct extent_buffer
*eb
;
59 while (!list_empty(&states
)) {
60 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
61 printk(KERN_ERR
"btrfs state leak: start %llu end %llu "
62 "state %lu in tree %p refs %d\n",
63 (unsigned long long)state
->start
,
64 (unsigned long long)state
->end
,
65 state
->state
, state
->tree
, atomic_read(&state
->refs
));
66 list_del(&state
->leak_list
);
67 kmem_cache_free(extent_state_cache
, state
);
70 while (!list_empty(&buffers
)) {
71 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
72 printk(KERN_ERR
"btrfs buffer leak start %llu len %lu "
73 "refs %d\n", (unsigned long long)eb
->start
,
74 eb
->len
, atomic_read(&eb
->refs
));
75 list_del(&eb
->leak_list
);
76 kmem_cache_free(extent_buffer_cache
, eb
);
80 #define btrfs_leak_debug_add(new, head) do {} while (0)
81 #define btrfs_leak_debug_del(entry) do {} while (0)
82 #define btrfs_leak_debug_check() do {} while (0)
85 #define BUFFER_LRU_MAX 64
90 struct rb_node rb_node
;
93 struct extent_page_data
{
95 struct extent_io_tree
*tree
;
96 get_extent_t
*get_extent
;
97 unsigned long bio_flags
;
99 /* tells writepage not to lock the state bits for this range
100 * it still does the unlocking
102 unsigned int extent_locked
:1;
104 /* tells the submit_bio code to use a WRITE_SYNC */
105 unsigned int sync_io
:1;
108 static noinline
void flush_write_bio(void *data
);
109 static inline struct btrfs_fs_info
*
110 tree_fs_info(struct extent_io_tree
*tree
)
112 return btrfs_sb(tree
->mapping
->host
->i_sb
);
115 int __init
extent_io_init(void)
117 extent_state_cache
= kmem_cache_create("btrfs_extent_state",
118 sizeof(struct extent_state
), 0,
119 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
120 if (!extent_state_cache
)
123 extent_buffer_cache
= kmem_cache_create("btrfs_extent_buffer",
124 sizeof(struct extent_buffer
), 0,
125 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
126 if (!extent_buffer_cache
)
127 goto free_state_cache
;
131 kmem_cache_destroy(extent_state_cache
);
135 void extent_io_exit(void)
137 btrfs_leak_debug_check();
140 * Make sure all delayed rcu free are flushed before we
144 if (extent_state_cache
)
145 kmem_cache_destroy(extent_state_cache
);
146 if (extent_buffer_cache
)
147 kmem_cache_destroy(extent_buffer_cache
);
150 void extent_io_tree_init(struct extent_io_tree
*tree
,
151 struct address_space
*mapping
)
153 tree
->state
= RB_ROOT
;
154 INIT_RADIX_TREE(&tree
->buffer
, GFP_ATOMIC
);
156 tree
->dirty_bytes
= 0;
157 spin_lock_init(&tree
->lock
);
158 spin_lock_init(&tree
->buffer_lock
);
159 tree
->mapping
= mapping
;
162 static struct extent_state
*alloc_extent_state(gfp_t mask
)
164 struct extent_state
*state
;
166 state
= kmem_cache_alloc(extent_state_cache
, mask
);
172 btrfs_leak_debug_add(&state
->leak_list
, &states
);
173 atomic_set(&state
->refs
, 1);
174 init_waitqueue_head(&state
->wq
);
175 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
179 void free_extent_state(struct extent_state
*state
)
183 if (atomic_dec_and_test(&state
->refs
)) {
184 WARN_ON(state
->tree
);
185 btrfs_leak_debug_del(&state
->leak_list
);
186 trace_free_extent_state(state
, _RET_IP_
);
187 kmem_cache_free(extent_state_cache
, state
);
191 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
192 struct rb_node
*node
)
194 struct rb_node
**p
= &root
->rb_node
;
195 struct rb_node
*parent
= NULL
;
196 struct tree_entry
*entry
;
200 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
202 if (offset
< entry
->start
)
204 else if (offset
> entry
->end
)
210 rb_link_node(node
, parent
, p
);
211 rb_insert_color(node
, root
);
215 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
216 struct rb_node
**prev_ret
,
217 struct rb_node
**next_ret
)
219 struct rb_root
*root
= &tree
->state
;
220 struct rb_node
*n
= root
->rb_node
;
221 struct rb_node
*prev
= NULL
;
222 struct rb_node
*orig_prev
= NULL
;
223 struct tree_entry
*entry
;
224 struct tree_entry
*prev_entry
= NULL
;
227 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
231 if (offset
< entry
->start
)
233 else if (offset
> entry
->end
)
241 while (prev
&& offset
> prev_entry
->end
) {
242 prev
= rb_next(prev
);
243 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
250 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
251 while (prev
&& offset
< prev_entry
->start
) {
252 prev
= rb_prev(prev
);
253 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
260 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
263 struct rb_node
*prev
= NULL
;
266 ret
= __etree_search(tree
, offset
, &prev
, NULL
);
272 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
273 struct extent_state
*other
)
275 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
276 tree
->ops
->merge_extent_hook(tree
->mapping
->host
, new,
281 * utility function to look for merge candidates inside a given range.
282 * Any extents with matching state are merged together into a single
283 * extent in the tree. Extents with EXTENT_IO in their state field
284 * are not merged because the end_io handlers need to be able to do
285 * operations on them without sleeping (or doing allocations/splits).
287 * This should be called with the tree lock held.
289 static void merge_state(struct extent_io_tree
*tree
,
290 struct extent_state
*state
)
292 struct extent_state
*other
;
293 struct rb_node
*other_node
;
295 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
298 other_node
= rb_prev(&state
->rb_node
);
300 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
301 if (other
->end
== state
->start
- 1 &&
302 other
->state
== state
->state
) {
303 merge_cb(tree
, state
, other
);
304 state
->start
= other
->start
;
306 rb_erase(&other
->rb_node
, &tree
->state
);
307 free_extent_state(other
);
310 other_node
= rb_next(&state
->rb_node
);
312 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
313 if (other
->start
== state
->end
+ 1 &&
314 other
->state
== state
->state
) {
315 merge_cb(tree
, state
, other
);
316 state
->end
= other
->end
;
318 rb_erase(&other
->rb_node
, &tree
->state
);
319 free_extent_state(other
);
324 static void set_state_cb(struct extent_io_tree
*tree
,
325 struct extent_state
*state
, unsigned long *bits
)
327 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
328 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
, bits
);
331 static void clear_state_cb(struct extent_io_tree
*tree
,
332 struct extent_state
*state
, unsigned long *bits
)
334 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
335 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
, bits
);
338 static void set_state_bits(struct extent_io_tree
*tree
,
339 struct extent_state
*state
, unsigned long *bits
);
342 * insert an extent_state struct into the tree. 'bits' are set on the
343 * struct before it is inserted.
345 * This may return -EEXIST if the extent is already there, in which case the
346 * state struct is freed.
348 * The tree lock is not taken internally. This is a utility function and
349 * probably isn't what you want to call (see set/clear_extent_bit).
351 static int insert_state(struct extent_io_tree
*tree
,
352 struct extent_state
*state
, u64 start
, u64 end
,
355 struct rb_node
*node
;
358 WARN(1, KERN_ERR
"btrfs end < start %llu %llu\n",
359 (unsigned long long)end
,
360 (unsigned long long)start
);
361 state
->start
= start
;
364 set_state_bits(tree
, state
, bits
);
366 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
368 struct extent_state
*found
;
369 found
= rb_entry(node
, struct extent_state
, rb_node
);
370 printk(KERN_ERR
"btrfs found node %llu %llu on insert of "
371 "%llu %llu\n", (unsigned long long)found
->start
,
372 (unsigned long long)found
->end
,
373 (unsigned long long)start
, (unsigned long long)end
);
377 merge_state(tree
, state
);
381 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
384 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
385 tree
->ops
->split_extent_hook(tree
->mapping
->host
, orig
, split
);
389 * split a given extent state struct in two, inserting the preallocated
390 * struct 'prealloc' as the newly created second half. 'split' indicates an
391 * offset inside 'orig' where it should be split.
394 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
395 * are two extent state structs in the tree:
396 * prealloc: [orig->start, split - 1]
397 * orig: [ split, orig->end ]
399 * The tree locks are not taken by this function. They need to be held
402 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
403 struct extent_state
*prealloc
, u64 split
)
405 struct rb_node
*node
;
407 split_cb(tree
, orig
, split
);
409 prealloc
->start
= orig
->start
;
410 prealloc
->end
= split
- 1;
411 prealloc
->state
= orig
->state
;
414 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
416 free_extent_state(prealloc
);
419 prealloc
->tree
= tree
;
423 static struct extent_state
*next_state(struct extent_state
*state
)
425 struct rb_node
*next
= rb_next(&state
->rb_node
);
427 return rb_entry(next
, struct extent_state
, rb_node
);
433 * utility function to clear some bits in an extent state struct.
434 * it will optionally wake up any one waiting on this state (wake == 1).
436 * If no bits are set on the state struct after clearing things, the
437 * struct is freed and removed from the tree
439 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
440 struct extent_state
*state
,
441 unsigned long *bits
, int wake
)
443 struct extent_state
*next
;
444 unsigned long bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
446 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
447 u64 range
= state
->end
- state
->start
+ 1;
448 WARN_ON(range
> tree
->dirty_bytes
);
449 tree
->dirty_bytes
-= range
;
451 clear_state_cb(tree
, state
, bits
);
452 state
->state
&= ~bits_to_clear
;
455 if (state
->state
== 0) {
456 next
= next_state(state
);
458 rb_erase(&state
->rb_node
, &tree
->state
);
460 free_extent_state(state
);
465 merge_state(tree
, state
);
466 next
= next_state(state
);
471 static struct extent_state
*
472 alloc_extent_state_atomic(struct extent_state
*prealloc
)
475 prealloc
= alloc_extent_state(GFP_ATOMIC
);
480 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
482 btrfs_panic(tree_fs_info(tree
), err
, "Locking error: "
483 "Extent tree was modified by another "
484 "thread while locked.");
488 * clear some bits on a range in the tree. This may require splitting
489 * or inserting elements in the tree, so the gfp mask is used to
490 * indicate which allocations or sleeping are allowed.
492 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
493 * the given range from the tree regardless of state (ie for truncate).
495 * the range [start, end] is inclusive.
497 * This takes the tree lock, and returns 0 on success and < 0 on error.
499 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
500 unsigned long bits
, int wake
, int delete,
501 struct extent_state
**cached_state
,
504 struct extent_state
*state
;
505 struct extent_state
*cached
;
506 struct extent_state
*prealloc
= NULL
;
507 struct rb_node
*node
;
513 bits
|= ~EXTENT_CTLBITS
;
514 bits
|= EXTENT_FIRST_DELALLOC
;
516 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
519 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
520 prealloc
= alloc_extent_state(mask
);
525 spin_lock(&tree
->lock
);
527 cached
= *cached_state
;
530 *cached_state
= NULL
;
534 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
535 cached
->end
> start
) {
537 atomic_dec(&cached
->refs
);
542 free_extent_state(cached
);
545 * this search will find the extents that end after
548 node
= tree_search(tree
, start
);
551 state
= rb_entry(node
, struct extent_state
, rb_node
);
553 if (state
->start
> end
)
555 WARN_ON(state
->end
< start
);
556 last_end
= state
->end
;
558 /* the state doesn't have the wanted bits, go ahead */
559 if (!(state
->state
& bits
)) {
560 state
= next_state(state
);
565 * | ---- desired range ---- |
567 * | ------------- state -------------- |
569 * We need to split the extent we found, and may flip
570 * bits on second half.
572 * If the extent we found extends past our range, we
573 * just split and search again. It'll get split again
574 * the next time though.
576 * If the extent we found is inside our range, we clear
577 * the desired bit on it.
580 if (state
->start
< start
) {
581 prealloc
= alloc_extent_state_atomic(prealloc
);
583 err
= split_state(tree
, state
, prealloc
, start
);
585 extent_io_tree_panic(tree
, err
);
590 if (state
->end
<= end
) {
591 state
= clear_state_bit(tree
, state
, &bits
, wake
);
597 * | ---- desired range ---- |
599 * We need to split the extent, and clear the bit
602 if (state
->start
<= end
&& state
->end
> end
) {
603 prealloc
= alloc_extent_state_atomic(prealloc
);
605 err
= split_state(tree
, state
, prealloc
, end
+ 1);
607 extent_io_tree_panic(tree
, err
);
612 clear_state_bit(tree
, prealloc
, &bits
, wake
);
618 state
= clear_state_bit(tree
, state
, &bits
, wake
);
620 if (last_end
== (u64
)-1)
622 start
= last_end
+ 1;
623 if (start
<= end
&& state
&& !need_resched())
628 spin_unlock(&tree
->lock
);
630 free_extent_state(prealloc
);
637 spin_unlock(&tree
->lock
);
638 if (mask
& __GFP_WAIT
)
643 static void wait_on_state(struct extent_io_tree
*tree
,
644 struct extent_state
*state
)
645 __releases(tree
->lock
)
646 __acquires(tree
->lock
)
649 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
650 spin_unlock(&tree
->lock
);
652 spin_lock(&tree
->lock
);
653 finish_wait(&state
->wq
, &wait
);
657 * waits for one or more bits to clear on a range in the state tree.
658 * The range [start, end] is inclusive.
659 * The tree lock is taken by this function
661 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
664 struct extent_state
*state
;
665 struct rb_node
*node
;
667 spin_lock(&tree
->lock
);
671 * this search will find all the extents that end after
674 node
= tree_search(tree
, start
);
678 state
= rb_entry(node
, struct extent_state
, rb_node
);
680 if (state
->start
> end
)
683 if (state
->state
& bits
) {
684 start
= state
->start
;
685 atomic_inc(&state
->refs
);
686 wait_on_state(tree
, state
);
687 free_extent_state(state
);
690 start
= state
->end
+ 1;
695 cond_resched_lock(&tree
->lock
);
698 spin_unlock(&tree
->lock
);
701 static void set_state_bits(struct extent_io_tree
*tree
,
702 struct extent_state
*state
,
705 unsigned long bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
707 set_state_cb(tree
, state
, bits
);
708 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
709 u64 range
= state
->end
- state
->start
+ 1;
710 tree
->dirty_bytes
+= range
;
712 state
->state
|= bits_to_set
;
715 static void cache_state(struct extent_state
*state
,
716 struct extent_state
**cached_ptr
)
718 if (cached_ptr
&& !(*cached_ptr
)) {
719 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
)) {
721 atomic_inc(&state
->refs
);
726 static void uncache_state(struct extent_state
**cached_ptr
)
728 if (cached_ptr
&& (*cached_ptr
)) {
729 struct extent_state
*state
= *cached_ptr
;
731 free_extent_state(state
);
736 * set some bits on a range in the tree. This may require allocations or
737 * sleeping, so the gfp mask is used to indicate what is allowed.
739 * If any of the exclusive bits are set, this will fail with -EEXIST if some
740 * part of the range already has the desired bits set. The start of the
741 * existing range is returned in failed_start in this case.
743 * [start, end] is inclusive This takes the tree lock.
746 static int __must_check
747 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
748 unsigned long bits
, unsigned long exclusive_bits
,
749 u64
*failed_start
, struct extent_state
**cached_state
,
752 struct extent_state
*state
;
753 struct extent_state
*prealloc
= NULL
;
754 struct rb_node
*node
;
759 bits
|= EXTENT_FIRST_DELALLOC
;
761 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
762 prealloc
= alloc_extent_state(mask
);
766 spin_lock(&tree
->lock
);
767 if (cached_state
&& *cached_state
) {
768 state
= *cached_state
;
769 if (state
->start
<= start
&& state
->end
> start
&&
771 node
= &state
->rb_node
;
776 * this search will find all the extents that end after
779 node
= tree_search(tree
, start
);
781 prealloc
= alloc_extent_state_atomic(prealloc
);
783 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
785 extent_io_tree_panic(tree
, err
);
790 state
= rb_entry(node
, struct extent_state
, rb_node
);
792 last_start
= state
->start
;
793 last_end
= state
->end
;
796 * | ---- desired range ---- |
799 * Just lock what we found and keep going
801 if (state
->start
== start
&& state
->end
<= end
) {
802 if (state
->state
& exclusive_bits
) {
803 *failed_start
= state
->start
;
808 set_state_bits(tree
, state
, &bits
);
809 cache_state(state
, cached_state
);
810 merge_state(tree
, state
);
811 if (last_end
== (u64
)-1)
813 start
= last_end
+ 1;
814 state
= next_state(state
);
815 if (start
< end
&& state
&& state
->start
== start
&&
822 * | ---- desired range ---- |
825 * | ------------- state -------------- |
827 * We need to split the extent we found, and may flip bits on
830 * If the extent we found extends past our
831 * range, we just split and search again. It'll get split
832 * again the next time though.
834 * If the extent we found is inside our range, we set the
837 if (state
->start
< start
) {
838 if (state
->state
& exclusive_bits
) {
839 *failed_start
= start
;
844 prealloc
= alloc_extent_state_atomic(prealloc
);
846 err
= split_state(tree
, state
, prealloc
, start
);
848 extent_io_tree_panic(tree
, err
);
853 if (state
->end
<= end
) {
854 set_state_bits(tree
, state
, &bits
);
855 cache_state(state
, cached_state
);
856 merge_state(tree
, state
);
857 if (last_end
== (u64
)-1)
859 start
= last_end
+ 1;
860 state
= next_state(state
);
861 if (start
< end
&& state
&& state
->start
== start
&&
868 * | ---- desired range ---- |
869 * | state | or | state |
871 * There's a hole, we need to insert something in it and
872 * ignore the extent we found.
874 if (state
->start
> start
) {
876 if (end
< last_start
)
879 this_end
= last_start
- 1;
881 prealloc
= alloc_extent_state_atomic(prealloc
);
885 * Avoid to free 'prealloc' if it can be merged with
888 err
= insert_state(tree
, prealloc
, start
, this_end
,
891 extent_io_tree_panic(tree
, err
);
893 cache_state(prealloc
, cached_state
);
895 start
= this_end
+ 1;
899 * | ---- desired range ---- |
901 * We need to split the extent, and set the bit
904 if (state
->start
<= end
&& state
->end
> end
) {
905 if (state
->state
& exclusive_bits
) {
906 *failed_start
= start
;
911 prealloc
= alloc_extent_state_atomic(prealloc
);
913 err
= split_state(tree
, state
, prealloc
, end
+ 1);
915 extent_io_tree_panic(tree
, err
);
917 set_state_bits(tree
, prealloc
, &bits
);
918 cache_state(prealloc
, cached_state
);
919 merge_state(tree
, prealloc
);
927 spin_unlock(&tree
->lock
);
929 free_extent_state(prealloc
);
936 spin_unlock(&tree
->lock
);
937 if (mask
& __GFP_WAIT
)
942 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
943 unsigned long bits
, u64
* failed_start
,
944 struct extent_state
**cached_state
, gfp_t mask
)
946 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
952 * convert_extent_bit - convert all bits in a given range from one bit to
954 * @tree: the io tree to search
955 * @start: the start offset in bytes
956 * @end: the end offset in bytes (inclusive)
957 * @bits: the bits to set in this range
958 * @clear_bits: the bits to clear in this range
959 * @cached_state: state that we're going to cache
960 * @mask: the allocation mask
962 * This will go through and set bits for the given range. If any states exist
963 * already in this range they are set with the given bit and cleared of the
964 * clear_bits. This is only meant to be used by things that are mergeable, ie
965 * converting from say DELALLOC to DIRTY. This is not meant to be used with
966 * boundary bits like LOCK.
968 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
969 unsigned long bits
, unsigned long clear_bits
,
970 struct extent_state
**cached_state
, gfp_t mask
)
972 struct extent_state
*state
;
973 struct extent_state
*prealloc
= NULL
;
974 struct rb_node
*node
;
980 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
981 prealloc
= alloc_extent_state(mask
);
986 spin_lock(&tree
->lock
);
987 if (cached_state
&& *cached_state
) {
988 state
= *cached_state
;
989 if (state
->start
<= start
&& state
->end
> start
&&
991 node
= &state
->rb_node
;
997 * this search will find all the extents that end after
1000 node
= tree_search(tree
, start
);
1002 prealloc
= alloc_extent_state_atomic(prealloc
);
1007 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
1010 extent_io_tree_panic(tree
, err
);
1013 state
= rb_entry(node
, struct extent_state
, rb_node
);
1015 last_start
= state
->start
;
1016 last_end
= state
->end
;
1019 * | ---- desired range ---- |
1022 * Just lock what we found and keep going
1024 if (state
->start
== start
&& state
->end
<= end
) {
1025 set_state_bits(tree
, state
, &bits
);
1026 cache_state(state
, cached_state
);
1027 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1028 if (last_end
== (u64
)-1)
1030 start
= last_end
+ 1;
1031 if (start
< end
&& state
&& state
->start
== start
&&
1038 * | ---- desired range ---- |
1041 * | ------------- state -------------- |
1043 * We need to split the extent we found, and may flip bits on
1046 * If the extent we found extends past our
1047 * range, we just split and search again. It'll get split
1048 * again the next time though.
1050 * If the extent we found is inside our range, we set the
1051 * desired bit on it.
1053 if (state
->start
< start
) {
1054 prealloc
= alloc_extent_state_atomic(prealloc
);
1059 err
= split_state(tree
, state
, prealloc
, start
);
1061 extent_io_tree_panic(tree
, err
);
1065 if (state
->end
<= end
) {
1066 set_state_bits(tree
, state
, &bits
);
1067 cache_state(state
, cached_state
);
1068 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1069 if (last_end
== (u64
)-1)
1071 start
= last_end
+ 1;
1072 if (start
< end
&& state
&& state
->start
== start
&&
1079 * | ---- desired range ---- |
1080 * | state | or | state |
1082 * There's a hole, we need to insert something in it and
1083 * ignore the extent we found.
1085 if (state
->start
> start
) {
1087 if (end
< last_start
)
1090 this_end
= last_start
- 1;
1092 prealloc
= alloc_extent_state_atomic(prealloc
);
1099 * Avoid to free 'prealloc' if it can be merged with
1102 err
= insert_state(tree
, prealloc
, start
, this_end
,
1105 extent_io_tree_panic(tree
, err
);
1106 cache_state(prealloc
, cached_state
);
1108 start
= this_end
+ 1;
1112 * | ---- desired range ---- |
1114 * We need to split the extent, and set the bit
1117 if (state
->start
<= end
&& state
->end
> end
) {
1118 prealloc
= alloc_extent_state_atomic(prealloc
);
1124 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1126 extent_io_tree_panic(tree
, err
);
1128 set_state_bits(tree
, prealloc
, &bits
);
1129 cache_state(prealloc
, cached_state
);
1130 clear_state_bit(tree
, prealloc
, &clear_bits
, 0);
1138 spin_unlock(&tree
->lock
);
1140 free_extent_state(prealloc
);
1147 spin_unlock(&tree
->lock
);
1148 if (mask
& __GFP_WAIT
)
1153 /* wrappers around set/clear extent bit */
1154 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1157 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, NULL
,
1161 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1162 unsigned long bits
, gfp_t mask
)
1164 return set_extent_bit(tree
, start
, end
, bits
, NULL
,
1168 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1169 unsigned long bits
, gfp_t mask
)
1171 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, mask
);
1174 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1175 struct extent_state
**cached_state
, gfp_t mask
)
1177 return set_extent_bit(tree
, start
, end
,
1178 EXTENT_DELALLOC
| EXTENT_UPTODATE
,
1179 NULL
, cached_state
, mask
);
1182 int set_extent_defrag(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1183 struct extent_state
**cached_state
, gfp_t mask
)
1185 return set_extent_bit(tree
, start
, end
,
1186 EXTENT_DELALLOC
| EXTENT_UPTODATE
| EXTENT_DEFRAG
,
1187 NULL
, cached_state
, mask
);
1190 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1193 return clear_extent_bit(tree
, start
, end
,
1194 EXTENT_DIRTY
| EXTENT_DELALLOC
|
1195 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
, mask
);
1198 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1201 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, NULL
,
1205 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1206 struct extent_state
**cached_state
, gfp_t mask
)
1208 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, NULL
,
1209 cached_state
, mask
);
1212 int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1213 struct extent_state
**cached_state
, gfp_t mask
)
1215 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0,
1216 cached_state
, mask
);
1220 * either insert or lock state struct between start and end use mask to tell
1221 * us if waiting is desired.
1223 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1224 unsigned long bits
, struct extent_state
**cached_state
)
1229 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
1230 EXTENT_LOCKED
, &failed_start
,
1231 cached_state
, GFP_NOFS
);
1232 if (err
== -EEXIST
) {
1233 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1234 start
= failed_start
;
1237 WARN_ON(start
> end
);
1242 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1244 return lock_extent_bits(tree
, start
, end
, 0, NULL
);
1247 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1252 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1253 &failed_start
, NULL
, GFP_NOFS
);
1254 if (err
== -EEXIST
) {
1255 if (failed_start
> start
)
1256 clear_extent_bit(tree
, start
, failed_start
- 1,
1257 EXTENT_LOCKED
, 1, 0, NULL
, GFP_NOFS
);
1263 int unlock_extent_cached(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1264 struct extent_state
**cached
, gfp_t mask
)
1266 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, cached
,
1270 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1272 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, NULL
,
1276 int extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1278 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1279 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1282 while (index
<= end_index
) {
1283 page
= find_get_page(inode
->i_mapping
, index
);
1284 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1285 clear_page_dirty_for_io(page
);
1286 page_cache_release(page
);
1292 int extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1294 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1295 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1298 while (index
<= end_index
) {
1299 page
= find_get_page(inode
->i_mapping
, index
);
1300 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1301 account_page_redirty(page
);
1302 __set_page_dirty_nobuffers(page
);
1303 page_cache_release(page
);
1310 * helper function to set both pages and extents in the tree writeback
1312 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1314 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1315 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1318 while (index
<= end_index
) {
1319 page
= find_get_page(tree
->mapping
, index
);
1320 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1321 set_page_writeback(page
);
1322 page_cache_release(page
);
1328 /* find the first state struct with 'bits' set after 'start', and
1329 * return it. tree->lock must be held. NULL will returned if
1330 * nothing was found after 'start'
1332 static struct extent_state
*
1333 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1334 u64 start
, unsigned long bits
)
1336 struct rb_node
*node
;
1337 struct extent_state
*state
;
1340 * this search will find all the extents that end after
1343 node
= tree_search(tree
, start
);
1348 state
= rb_entry(node
, struct extent_state
, rb_node
);
1349 if (state
->end
>= start
&& (state
->state
& bits
))
1352 node
= rb_next(node
);
1361 * find the first offset in the io tree with 'bits' set. zero is
1362 * returned if we find something, and *start_ret and *end_ret are
1363 * set to reflect the state struct that was found.
1365 * If nothing was found, 1 is returned. If found something, return 0.
1367 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1368 u64
*start_ret
, u64
*end_ret
, unsigned long bits
,
1369 struct extent_state
**cached_state
)
1371 struct extent_state
*state
;
1375 spin_lock(&tree
->lock
);
1376 if (cached_state
&& *cached_state
) {
1377 state
= *cached_state
;
1378 if (state
->end
== start
- 1 && state
->tree
) {
1379 n
= rb_next(&state
->rb_node
);
1381 state
= rb_entry(n
, struct extent_state
,
1383 if (state
->state
& bits
)
1387 free_extent_state(*cached_state
);
1388 *cached_state
= NULL
;
1391 free_extent_state(*cached_state
);
1392 *cached_state
= NULL
;
1395 state
= find_first_extent_bit_state(tree
, start
, bits
);
1398 cache_state(state
, cached_state
);
1399 *start_ret
= state
->start
;
1400 *end_ret
= state
->end
;
1404 spin_unlock(&tree
->lock
);
1409 * find a contiguous range of bytes in the file marked as delalloc, not
1410 * more than 'max_bytes'. start and end are used to return the range,
1412 * 1 is returned if we find something, 0 if nothing was in the tree
1414 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1415 u64
*start
, u64
*end
, u64 max_bytes
,
1416 struct extent_state
**cached_state
)
1418 struct rb_node
*node
;
1419 struct extent_state
*state
;
1420 u64 cur_start
= *start
;
1422 u64 total_bytes
= 0;
1424 spin_lock(&tree
->lock
);
1427 * this search will find all the extents that end after
1430 node
= tree_search(tree
, cur_start
);
1438 state
= rb_entry(node
, struct extent_state
, rb_node
);
1439 if (found
&& (state
->start
!= cur_start
||
1440 (state
->state
& EXTENT_BOUNDARY
))) {
1443 if (!(state
->state
& EXTENT_DELALLOC
)) {
1449 *start
= state
->start
;
1450 *cached_state
= state
;
1451 atomic_inc(&state
->refs
);
1455 cur_start
= state
->end
+ 1;
1456 node
= rb_next(node
);
1459 total_bytes
+= state
->end
- state
->start
+ 1;
1460 if (total_bytes
>= max_bytes
)
1464 spin_unlock(&tree
->lock
);
1468 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1469 struct page
*locked_page
,
1473 struct page
*pages
[16];
1474 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1475 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1476 unsigned long nr_pages
= end_index
- index
+ 1;
1479 if (index
== locked_page
->index
&& end_index
== index
)
1482 while (nr_pages
> 0) {
1483 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1484 min_t(unsigned long, nr_pages
,
1485 ARRAY_SIZE(pages
)), pages
);
1486 for (i
= 0; i
< ret
; i
++) {
1487 if (pages
[i
] != locked_page
)
1488 unlock_page(pages
[i
]);
1489 page_cache_release(pages
[i
]);
1497 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1498 struct page
*locked_page
,
1502 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1503 unsigned long start_index
= index
;
1504 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1505 unsigned long pages_locked
= 0;
1506 struct page
*pages
[16];
1507 unsigned long nrpages
;
1511 /* the caller is responsible for locking the start index */
1512 if (index
== locked_page
->index
&& index
== end_index
)
1515 /* skip the page at the start index */
1516 nrpages
= end_index
- index
+ 1;
1517 while (nrpages
> 0) {
1518 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1519 min_t(unsigned long,
1520 nrpages
, ARRAY_SIZE(pages
)), pages
);
1525 /* now we have an array of pages, lock them all */
1526 for (i
= 0; i
< ret
; i
++) {
1528 * the caller is taking responsibility for
1531 if (pages
[i
] != locked_page
) {
1532 lock_page(pages
[i
]);
1533 if (!PageDirty(pages
[i
]) ||
1534 pages
[i
]->mapping
!= inode
->i_mapping
) {
1536 unlock_page(pages
[i
]);
1537 page_cache_release(pages
[i
]);
1541 page_cache_release(pages
[i
]);
1550 if (ret
&& pages_locked
) {
1551 __unlock_for_delalloc(inode
, locked_page
,
1553 ((u64
)(start_index
+ pages_locked
- 1)) <<
1560 * find a contiguous range of bytes in the file marked as delalloc, not
1561 * more than 'max_bytes'. start and end are used to return the range,
1563 * 1 is returned if we find something, 0 if nothing was in the tree
1565 static noinline u64
find_lock_delalloc_range(struct inode
*inode
,
1566 struct extent_io_tree
*tree
,
1567 struct page
*locked_page
,
1568 u64
*start
, u64
*end
,
1574 struct extent_state
*cached_state
= NULL
;
1579 /* step one, find a bunch of delalloc bytes starting at start */
1580 delalloc_start
= *start
;
1582 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1583 max_bytes
, &cached_state
);
1584 if (!found
|| delalloc_end
<= *start
) {
1585 *start
= delalloc_start
;
1586 *end
= delalloc_end
;
1587 free_extent_state(cached_state
);
1592 * start comes from the offset of locked_page. We have to lock
1593 * pages in order, so we can't process delalloc bytes before
1596 if (delalloc_start
< *start
)
1597 delalloc_start
= *start
;
1600 * make sure to limit the number of pages we try to lock down
1603 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
&& loops
)
1604 delalloc_end
= delalloc_start
+ PAGE_CACHE_SIZE
- 1;
1606 /* step two, lock all the pages after the page that has start */
1607 ret
= lock_delalloc_pages(inode
, locked_page
,
1608 delalloc_start
, delalloc_end
);
1609 if (ret
== -EAGAIN
) {
1610 /* some of the pages are gone, lets avoid looping by
1611 * shortening the size of the delalloc range we're searching
1613 free_extent_state(cached_state
);
1615 unsigned long offset
= (*start
) & (PAGE_CACHE_SIZE
- 1);
1616 max_bytes
= PAGE_CACHE_SIZE
- offset
;
1624 BUG_ON(ret
); /* Only valid values are 0 and -EAGAIN */
1626 /* step three, lock the state bits for the whole range */
1627 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, 0, &cached_state
);
1629 /* then test to make sure it is all still delalloc */
1630 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1631 EXTENT_DELALLOC
, 1, cached_state
);
1633 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1634 &cached_state
, GFP_NOFS
);
1635 __unlock_for_delalloc(inode
, locked_page
,
1636 delalloc_start
, delalloc_end
);
1640 free_extent_state(cached_state
);
1641 *start
= delalloc_start
;
1642 *end
= delalloc_end
;
1647 int extent_clear_unlock_delalloc(struct inode
*inode
,
1648 struct extent_io_tree
*tree
,
1649 u64 start
, u64 end
, struct page
*locked_page
,
1653 struct page
*pages
[16];
1654 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1655 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1656 unsigned long nr_pages
= end_index
- index
+ 1;
1658 unsigned long clear_bits
= 0;
1660 if (op
& EXTENT_CLEAR_UNLOCK
)
1661 clear_bits
|= EXTENT_LOCKED
;
1662 if (op
& EXTENT_CLEAR_DIRTY
)
1663 clear_bits
|= EXTENT_DIRTY
;
1665 if (op
& EXTENT_CLEAR_DELALLOC
)
1666 clear_bits
|= EXTENT_DELALLOC
;
1668 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, NULL
, GFP_NOFS
);
1669 if (!(op
& (EXTENT_CLEAR_UNLOCK_PAGE
| EXTENT_CLEAR_DIRTY
|
1670 EXTENT_SET_WRITEBACK
| EXTENT_END_WRITEBACK
|
1671 EXTENT_SET_PRIVATE2
)))
1674 while (nr_pages
> 0) {
1675 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1676 min_t(unsigned long,
1677 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1678 for (i
= 0; i
< ret
; i
++) {
1680 if (op
& EXTENT_SET_PRIVATE2
)
1681 SetPagePrivate2(pages
[i
]);
1683 if (pages
[i
] == locked_page
) {
1684 page_cache_release(pages
[i
]);
1687 if (op
& EXTENT_CLEAR_DIRTY
)
1688 clear_page_dirty_for_io(pages
[i
]);
1689 if (op
& EXTENT_SET_WRITEBACK
)
1690 set_page_writeback(pages
[i
]);
1691 if (op
& EXTENT_END_WRITEBACK
)
1692 end_page_writeback(pages
[i
]);
1693 if (op
& EXTENT_CLEAR_UNLOCK_PAGE
)
1694 unlock_page(pages
[i
]);
1695 page_cache_release(pages
[i
]);
1705 * count the number of bytes in the tree that have a given bit(s)
1706 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1707 * cached. The total number found is returned.
1709 u64
count_range_bits(struct extent_io_tree
*tree
,
1710 u64
*start
, u64 search_end
, u64 max_bytes
,
1711 unsigned long bits
, int contig
)
1713 struct rb_node
*node
;
1714 struct extent_state
*state
;
1715 u64 cur_start
= *start
;
1716 u64 total_bytes
= 0;
1720 if (search_end
<= cur_start
) {
1725 spin_lock(&tree
->lock
);
1726 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1727 total_bytes
= tree
->dirty_bytes
;
1731 * this search will find all the extents that end after
1734 node
= tree_search(tree
, cur_start
);
1739 state
= rb_entry(node
, struct extent_state
, rb_node
);
1740 if (state
->start
> search_end
)
1742 if (contig
&& found
&& state
->start
> last
+ 1)
1744 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1745 total_bytes
+= min(search_end
, state
->end
) + 1 -
1746 max(cur_start
, state
->start
);
1747 if (total_bytes
>= max_bytes
)
1750 *start
= max(cur_start
, state
->start
);
1754 } else if (contig
&& found
) {
1757 node
= rb_next(node
);
1762 spin_unlock(&tree
->lock
);
1767 * set the private field for a given byte offset in the tree. If there isn't
1768 * an extent_state there already, this does nothing.
1770 int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1772 struct rb_node
*node
;
1773 struct extent_state
*state
;
1776 spin_lock(&tree
->lock
);
1778 * this search will find all the extents that end after
1781 node
= tree_search(tree
, start
);
1786 state
= rb_entry(node
, struct extent_state
, rb_node
);
1787 if (state
->start
!= start
) {
1791 state
->private = private;
1793 spin_unlock(&tree
->lock
);
1797 void extent_cache_csums_dio(struct extent_io_tree
*tree
, u64 start
, u32 csums
[],
1800 struct rb_node
*node
;
1801 struct extent_state
*state
;
1803 spin_lock(&tree
->lock
);
1805 * this search will find all the extents that end after
1808 node
= tree_search(tree
, start
);
1811 state
= rb_entry(node
, struct extent_state
, rb_node
);
1812 BUG_ON(state
->start
!= start
);
1815 state
->private = *csums
++;
1817 state
= next_state(state
);
1819 spin_unlock(&tree
->lock
);
1822 static inline u64
__btrfs_get_bio_offset(struct bio
*bio
, int bio_index
)
1824 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio_index
;
1826 return page_offset(bvec
->bv_page
) + bvec
->bv_offset
;
1829 void extent_cache_csums(struct extent_io_tree
*tree
, struct bio
*bio
, int bio_index
,
1830 u32 csums
[], int count
)
1832 struct rb_node
*node
;
1833 struct extent_state
*state
= NULL
;
1836 spin_lock(&tree
->lock
);
1838 start
= __btrfs_get_bio_offset(bio
, bio_index
);
1839 if (state
== NULL
|| state
->start
!= start
) {
1840 node
= tree_search(tree
, start
);
1843 state
= rb_entry(node
, struct extent_state
, rb_node
);
1844 BUG_ON(state
->start
!= start
);
1846 state
->private = *csums
++;
1850 state
= next_state(state
);
1852 spin_unlock(&tree
->lock
);
1855 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1857 struct rb_node
*node
;
1858 struct extent_state
*state
;
1861 spin_lock(&tree
->lock
);
1863 * this search will find all the extents that end after
1866 node
= tree_search(tree
, start
);
1871 state
= rb_entry(node
, struct extent_state
, rb_node
);
1872 if (state
->start
!= start
) {
1876 *private = state
->private;
1878 spin_unlock(&tree
->lock
);
1883 * searches a range in the state tree for a given mask.
1884 * If 'filled' == 1, this returns 1 only if every extent in the tree
1885 * has the bits set. Otherwise, 1 is returned if any bit in the
1886 * range is found set.
1888 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1889 unsigned long bits
, int filled
, struct extent_state
*cached
)
1891 struct extent_state
*state
= NULL
;
1892 struct rb_node
*node
;
1895 spin_lock(&tree
->lock
);
1896 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
1897 cached
->end
> start
)
1898 node
= &cached
->rb_node
;
1900 node
= tree_search(tree
, start
);
1901 while (node
&& start
<= end
) {
1902 state
= rb_entry(node
, struct extent_state
, rb_node
);
1904 if (filled
&& state
->start
> start
) {
1909 if (state
->start
> end
)
1912 if (state
->state
& bits
) {
1916 } else if (filled
) {
1921 if (state
->end
== (u64
)-1)
1924 start
= state
->end
+ 1;
1927 node
= rb_next(node
);
1934 spin_unlock(&tree
->lock
);
1939 * helper function to set a given page up to date if all the
1940 * extents in the tree for that page are up to date
1942 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
1944 u64 start
= page_offset(page
);
1945 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1946 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1947 SetPageUptodate(page
);
1951 * helper function to unlock a page if all the extents in the tree
1952 * for that page are unlocked
1954 static void check_page_locked(struct extent_io_tree
*tree
, struct page
*page
)
1956 u64 start
= page_offset(page
);
1957 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1958 if (!test_range_bit(tree
, start
, end
, EXTENT_LOCKED
, 0, NULL
))
1963 * helper function to end page writeback if all the extents
1964 * in the tree for that page are done with writeback
1966 static void check_page_writeback(struct extent_io_tree
*tree
,
1969 end_page_writeback(page
);
1973 * When IO fails, either with EIO or csum verification fails, we
1974 * try other mirrors that might have a good copy of the data. This
1975 * io_failure_record is used to record state as we go through all the
1976 * mirrors. If another mirror has good data, the page is set up to date
1977 * and things continue. If a good mirror can't be found, the original
1978 * bio end_io callback is called to indicate things have failed.
1980 struct io_failure_record
{
1985 unsigned long bio_flags
;
1991 static int free_io_failure(struct inode
*inode
, struct io_failure_record
*rec
,
1996 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
1998 set_state_private(failure_tree
, rec
->start
, 0);
1999 ret
= clear_extent_bits(failure_tree
, rec
->start
,
2000 rec
->start
+ rec
->len
- 1,
2001 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
2005 ret
= clear_extent_bits(&BTRFS_I(inode
)->io_tree
, rec
->start
,
2006 rec
->start
+ rec
->len
- 1,
2007 EXTENT_DAMAGED
, GFP_NOFS
);
2015 static void repair_io_failure_callback(struct bio
*bio
, int err
)
2017 complete(bio
->bi_private
);
2021 * this bypasses the standard btrfs submit functions deliberately, as
2022 * the standard behavior is to write all copies in a raid setup. here we only
2023 * want to write the one bad copy. so we do the mapping for ourselves and issue
2024 * submit_bio directly.
2025 * to avoid any synchronization issues, wait for the data after writing, which
2026 * actually prevents the read that triggered the error from finishing.
2027 * currently, there can be no more than two copies of every data bit. thus,
2028 * exactly one rewrite is required.
2030 int repair_io_failure(struct btrfs_fs_info
*fs_info
, u64 start
,
2031 u64 length
, u64 logical
, struct page
*page
,
2035 struct btrfs_device
*dev
;
2036 DECLARE_COMPLETION_ONSTACK(compl);
2039 struct btrfs_bio
*bbio
= NULL
;
2040 struct btrfs_mapping_tree
*map_tree
= &fs_info
->mapping_tree
;
2043 BUG_ON(!mirror_num
);
2045 /* we can't repair anything in raid56 yet */
2046 if (btrfs_is_parity_mirror(map_tree
, logical
, length
, mirror_num
))
2049 bio
= bio_alloc(GFP_NOFS
, 1);
2052 bio
->bi_private
= &compl;
2053 bio
->bi_end_io
= repair_io_failure_callback
;
2055 map_length
= length
;
2057 ret
= btrfs_map_block(fs_info
, WRITE
, logical
,
2058 &map_length
, &bbio
, mirror_num
);
2063 BUG_ON(mirror_num
!= bbio
->mirror_num
);
2064 sector
= bbio
->stripes
[mirror_num
-1].physical
>> 9;
2065 bio
->bi_sector
= sector
;
2066 dev
= bbio
->stripes
[mirror_num
-1].dev
;
2068 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2072 bio
->bi_bdev
= dev
->bdev
;
2073 bio_add_page(bio
, page
, length
, start
- page_offset(page
));
2074 btrfsic_submit_bio(WRITE_SYNC
, bio
);
2075 wait_for_completion(&compl);
2077 if (!test_bit(BIO_UPTODATE
, &bio
->bi_flags
)) {
2078 /* try to remap that extent elsewhere? */
2080 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2084 printk_ratelimited_in_rcu(KERN_INFO
"btrfs read error corrected: ino %lu off %llu "
2085 "(dev %s sector %llu)\n", page
->mapping
->host
->i_ino
,
2086 start
, rcu_str_deref(dev
->name
), sector
);
2092 int repair_eb_io_failure(struct btrfs_root
*root
, struct extent_buffer
*eb
,
2095 u64 start
= eb
->start
;
2096 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2099 for (i
= 0; i
< num_pages
; i
++) {
2100 struct page
*p
= extent_buffer_page(eb
, i
);
2101 ret
= repair_io_failure(root
->fs_info
, start
, PAGE_CACHE_SIZE
,
2102 start
, p
, mirror_num
);
2105 start
+= PAGE_CACHE_SIZE
;
2112 * each time an IO finishes, we do a fast check in the IO failure tree
2113 * to see if we need to process or clean up an io_failure_record
2115 static int clean_io_failure(u64 start
, struct page
*page
)
2118 u64 private_failure
;
2119 struct io_failure_record
*failrec
;
2120 struct btrfs_fs_info
*fs_info
;
2121 struct extent_state
*state
;
2125 struct inode
*inode
= page
->mapping
->host
;
2128 ret
= count_range_bits(&BTRFS_I(inode
)->io_failure_tree
, &private,
2129 (u64
)-1, 1, EXTENT_DIRTY
, 0);
2133 ret
= get_state_private(&BTRFS_I(inode
)->io_failure_tree
, start
,
2138 failrec
= (struct io_failure_record
*)(unsigned long) private_failure
;
2139 BUG_ON(!failrec
->this_mirror
);
2141 if (failrec
->in_validation
) {
2142 /* there was no real error, just free the record */
2143 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2149 spin_lock(&BTRFS_I(inode
)->io_tree
.lock
);
2150 state
= find_first_extent_bit_state(&BTRFS_I(inode
)->io_tree
,
2153 spin_unlock(&BTRFS_I(inode
)->io_tree
.lock
);
2155 if (state
&& state
->start
== failrec
->start
) {
2156 fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2157 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2159 if (num_copies
> 1) {
2160 ret
= repair_io_failure(fs_info
, start
, failrec
->len
,
2161 failrec
->logical
, page
,
2162 failrec
->failed_mirror
);
2170 ret
= free_io_failure(inode
, failrec
, did_repair
);
2176 * this is a generic handler for readpage errors (default
2177 * readpage_io_failed_hook). if other copies exist, read those and write back
2178 * good data to the failed position. does not investigate in remapping the
2179 * failed extent elsewhere, hoping the device will be smart enough to do this as
2183 static int bio_readpage_error(struct bio
*failed_bio
, struct page
*page
,
2184 u64 start
, u64 end
, int failed_mirror
,
2185 struct extent_state
*state
)
2187 struct io_failure_record
*failrec
= NULL
;
2189 struct extent_map
*em
;
2190 struct inode
*inode
= page
->mapping
->host
;
2191 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2192 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2193 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2200 BUG_ON(failed_bio
->bi_rw
& REQ_WRITE
);
2202 ret
= get_state_private(failure_tree
, start
, &private);
2204 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2207 failrec
->start
= start
;
2208 failrec
->len
= end
- start
+ 1;
2209 failrec
->this_mirror
= 0;
2210 failrec
->bio_flags
= 0;
2211 failrec
->in_validation
= 0;
2213 read_lock(&em_tree
->lock
);
2214 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2216 read_unlock(&em_tree
->lock
);
2221 if (em
->start
> start
|| em
->start
+ em
->len
< start
) {
2222 free_extent_map(em
);
2225 read_unlock(&em_tree
->lock
);
2231 logical
= start
- em
->start
;
2232 logical
= em
->block_start
+ logical
;
2233 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2234 logical
= em
->block_start
;
2235 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2236 extent_set_compress_type(&failrec
->bio_flags
,
2239 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2240 "len=%llu\n", logical
, start
, failrec
->len
);
2241 failrec
->logical
= logical
;
2242 free_extent_map(em
);
2244 /* set the bits in the private failure tree */
2245 ret
= set_extent_bits(failure_tree
, start
, end
,
2246 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
2248 ret
= set_state_private(failure_tree
, start
,
2249 (u64
)(unsigned long)failrec
);
2250 /* set the bits in the inode's tree */
2252 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
,
2259 failrec
= (struct io_failure_record
*)(unsigned long)private;
2260 pr_debug("bio_readpage_error: (found) logical=%llu, "
2261 "start=%llu, len=%llu, validation=%d\n",
2262 failrec
->logical
, failrec
->start
, failrec
->len
,
2263 failrec
->in_validation
);
2265 * when data can be on disk more than twice, add to failrec here
2266 * (e.g. with a list for failed_mirror) to make
2267 * clean_io_failure() clean all those errors at once.
2270 num_copies
= btrfs_num_copies(BTRFS_I(inode
)->root
->fs_info
,
2271 failrec
->logical
, failrec
->len
);
2272 if (num_copies
== 1) {
2274 * we only have a single copy of the data, so don't bother with
2275 * all the retry and error correction code that follows. no
2276 * matter what the error is, it is very likely to persist.
2278 pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
2279 "state=%p, num_copies=%d, next_mirror %d, "
2280 "failed_mirror %d\n", state
, num_copies
,
2281 failrec
->this_mirror
, failed_mirror
);
2282 free_io_failure(inode
, failrec
, 0);
2287 spin_lock(&tree
->lock
);
2288 state
= find_first_extent_bit_state(tree
, failrec
->start
,
2290 if (state
&& state
->start
!= failrec
->start
)
2292 spin_unlock(&tree
->lock
);
2296 * there are two premises:
2297 * a) deliver good data to the caller
2298 * b) correct the bad sectors on disk
2300 if (failed_bio
->bi_vcnt
> 1) {
2302 * to fulfill b), we need to know the exact failing sectors, as
2303 * we don't want to rewrite any more than the failed ones. thus,
2304 * we need separate read requests for the failed bio
2306 * if the following BUG_ON triggers, our validation request got
2307 * merged. we need separate requests for our algorithm to work.
2309 BUG_ON(failrec
->in_validation
);
2310 failrec
->in_validation
= 1;
2311 failrec
->this_mirror
= failed_mirror
;
2312 read_mode
= READ_SYNC
| REQ_FAILFAST_DEV
;
2315 * we're ready to fulfill a) and b) alongside. get a good copy
2316 * of the failed sector and if we succeed, we have setup
2317 * everything for repair_io_failure to do the rest for us.
2319 if (failrec
->in_validation
) {
2320 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2321 failrec
->in_validation
= 0;
2322 failrec
->this_mirror
= 0;
2324 failrec
->failed_mirror
= failed_mirror
;
2325 failrec
->this_mirror
++;
2326 if (failrec
->this_mirror
== failed_mirror
)
2327 failrec
->this_mirror
++;
2328 read_mode
= READ_SYNC
;
2331 if (!state
|| failrec
->this_mirror
> num_copies
) {
2332 pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
2333 "next_mirror %d, failed_mirror %d\n", state
,
2334 num_copies
, failrec
->this_mirror
, failed_mirror
);
2335 free_io_failure(inode
, failrec
, 0);
2339 bio
= bio_alloc(GFP_NOFS
, 1);
2341 free_io_failure(inode
, failrec
, 0);
2344 bio
->bi_private
= state
;
2345 bio
->bi_end_io
= failed_bio
->bi_end_io
;
2346 bio
->bi_sector
= failrec
->logical
>> 9;
2347 bio
->bi_bdev
= BTRFS_I(inode
)->root
->fs_info
->fs_devices
->latest_bdev
;
2350 bio_add_page(bio
, page
, failrec
->len
, start
- page_offset(page
));
2352 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2353 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode
,
2354 failrec
->this_mirror
, num_copies
, failrec
->in_validation
);
2356 ret
= tree
->ops
->submit_bio_hook(inode
, read_mode
, bio
,
2357 failrec
->this_mirror
,
2358 failrec
->bio_flags
, 0);
2362 /* lots and lots of room for performance fixes in the end_bio funcs */
2364 int end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2366 int uptodate
= (err
== 0);
2367 struct extent_io_tree
*tree
;
2370 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2372 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
2373 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
2374 end
, NULL
, uptodate
);
2380 ClearPageUptodate(page
);
2387 * after a writepage IO is done, we need to:
2388 * clear the uptodate bits on error
2389 * clear the writeback bits in the extent tree for this IO
2390 * end_page_writeback if the page has no more pending IO
2392 * Scheduling is not allowed, so the extent state tree is expected
2393 * to have one and only one object corresponding to this IO.
2395 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
2397 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2398 struct extent_io_tree
*tree
;
2404 struct page
*page
= bvec
->bv_page
;
2405 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2407 start
= page_offset(page
) + bvec
->bv_offset
;
2408 end
= start
+ bvec
->bv_len
- 1;
2410 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
2415 if (--bvec
>= bio
->bi_io_vec
)
2416 prefetchw(&bvec
->bv_page
->flags
);
2418 if (end_extent_writepage(page
, err
, start
, end
))
2422 end_page_writeback(page
);
2424 check_page_writeback(tree
, page
);
2425 } while (bvec
>= bio
->bi_io_vec
);
2431 * after a readpage IO is done, we need to:
2432 * clear the uptodate bits on error
2433 * set the uptodate bits if things worked
2434 * set the page up to date if all extents in the tree are uptodate
2435 * clear the lock bit in the extent tree
2436 * unlock the page if there are no other extents locked for it
2438 * Scheduling is not allowed, so the extent state tree is expected
2439 * to have one and only one object corresponding to this IO.
2441 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
2443 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2444 struct bio_vec
*bvec_end
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2445 struct bio_vec
*bvec
= bio
->bi_io_vec
;
2446 struct extent_io_tree
*tree
;
2457 struct page
*page
= bvec
->bv_page
;
2458 struct extent_state
*cached
= NULL
;
2459 struct extent_state
*state
;
2461 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2462 "mirror=%ld\n", (u64
)bio
->bi_sector
, err
,
2463 (long int)bio
->bi_bdev
);
2464 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2466 start
= page_offset(page
) + bvec
->bv_offset
;
2467 end
= start
+ bvec
->bv_len
- 1;
2469 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
2474 if (++bvec
<= bvec_end
)
2475 prefetchw(&bvec
->bv_page
->flags
);
2477 spin_lock(&tree
->lock
);
2478 state
= find_first_extent_bit_state(tree
, start
, EXTENT_LOCKED
);
2479 if (state
&& state
->start
== start
) {
2481 * take a reference on the state, unlock will drop
2484 cache_state(state
, &cached
);
2486 spin_unlock(&tree
->lock
);
2488 mirror
= (int)(unsigned long)bio
->bi_bdev
;
2489 if (uptodate
&& tree
->ops
&& tree
->ops
->readpage_end_io_hook
) {
2490 ret
= tree
->ops
->readpage_end_io_hook(page
, start
, end
,
2495 clean_io_failure(start
, page
);
2498 if (!uptodate
&& tree
->ops
&& tree
->ops
->readpage_io_failed_hook
) {
2499 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2501 test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
2503 } else if (!uptodate
) {
2505 * The generic bio_readpage_error handles errors the
2506 * following way: If possible, new read requests are
2507 * created and submitted and will end up in
2508 * end_bio_extent_readpage as well (if we're lucky, not
2509 * in the !uptodate case). In that case it returns 0 and
2510 * we just go on with the next page in our bio. If it
2511 * can't handle the error it will return -EIO and we
2512 * remain responsible for that page.
2514 ret
= bio_readpage_error(bio
, page
, start
, end
, mirror
, NULL
);
2517 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2520 uncache_state(&cached
);
2525 if (uptodate
&& tree
->track_uptodate
) {
2526 set_extent_uptodate(tree
, start
, end
, &cached
,
2529 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2533 SetPageUptodate(page
);
2535 ClearPageUptodate(page
);
2541 check_page_uptodate(tree
, page
);
2543 ClearPageUptodate(page
);
2546 check_page_locked(tree
, page
);
2548 } while (bvec
<= bvec_end
);
2554 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
2559 bio
= bio_alloc(gfp_flags
, nr_vecs
);
2561 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
2562 while (!bio
&& (nr_vecs
/= 2))
2563 bio
= bio_alloc(gfp_flags
, nr_vecs
);
2568 bio
->bi_bdev
= bdev
;
2569 bio
->bi_sector
= first_sector
;
2574 static int __must_check
submit_one_bio(int rw
, struct bio
*bio
,
2575 int mirror_num
, unsigned long bio_flags
)
2578 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2579 struct page
*page
= bvec
->bv_page
;
2580 struct extent_io_tree
*tree
= bio
->bi_private
;
2583 start
= page_offset(page
) + bvec
->bv_offset
;
2585 bio
->bi_private
= NULL
;
2589 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
2590 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
2591 mirror_num
, bio_flags
, start
);
2593 btrfsic_submit_bio(rw
, bio
);
2595 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
2601 static int merge_bio(int rw
, struct extent_io_tree
*tree
, struct page
*page
,
2602 unsigned long offset
, size_t size
, struct bio
*bio
,
2603 unsigned long bio_flags
)
2606 if (tree
->ops
&& tree
->ops
->merge_bio_hook
)
2607 ret
= tree
->ops
->merge_bio_hook(rw
, page
, offset
, size
, bio
,
2614 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
2615 struct page
*page
, sector_t sector
,
2616 size_t size
, unsigned long offset
,
2617 struct block_device
*bdev
,
2618 struct bio
**bio_ret
,
2619 unsigned long max_pages
,
2620 bio_end_io_t end_io_func
,
2622 unsigned long prev_bio_flags
,
2623 unsigned long bio_flags
)
2629 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
2630 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2631 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
2633 if (bio_ret
&& *bio_ret
) {
2636 contig
= bio
->bi_sector
== sector
;
2638 contig
= bio_end_sector(bio
) == sector
;
2640 if (prev_bio_flags
!= bio_flags
|| !contig
||
2641 merge_bio(rw
, tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2642 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2643 ret
= submit_one_bio(rw
, bio
, mirror_num
,
2652 if (this_compressed
)
2655 nr
= bio_get_nr_vecs(bdev
);
2657 bio
= btrfs_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
2661 bio_add_page(bio
, page
, page_size
, offset
);
2662 bio
->bi_end_io
= end_io_func
;
2663 bio
->bi_private
= tree
;
2668 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
2673 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2676 if (!PagePrivate(page
)) {
2677 SetPagePrivate(page
);
2678 page_cache_get(page
);
2679 set_page_private(page
, (unsigned long)eb
);
2681 WARN_ON(page
->private != (unsigned long)eb
);
2685 void set_page_extent_mapped(struct page
*page
)
2687 if (!PagePrivate(page
)) {
2688 SetPagePrivate(page
);
2689 page_cache_get(page
);
2690 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2695 * basic readpage implementation. Locked extent state structs are inserted
2696 * into the tree that are removed when the IO is done (by the end_io
2698 * XXX JDM: This needs looking at to ensure proper page locking
2700 static int __extent_read_full_page(struct extent_io_tree
*tree
,
2702 get_extent_t
*get_extent
,
2703 struct bio
**bio
, int mirror_num
,
2704 unsigned long *bio_flags
, int rw
)
2706 struct inode
*inode
= page
->mapping
->host
;
2707 u64 start
= page_offset(page
);
2708 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2712 u64 last_byte
= i_size_read(inode
);
2716 struct extent_map
*em
;
2717 struct block_device
*bdev
;
2718 struct btrfs_ordered_extent
*ordered
;
2721 size_t pg_offset
= 0;
2723 size_t disk_io_size
;
2724 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2725 unsigned long this_bio_flag
= 0;
2727 set_page_extent_mapped(page
);
2729 if (!PageUptodate(page
)) {
2730 if (cleancache_get_page(page
) == 0) {
2731 BUG_ON(blocksize
!= PAGE_SIZE
);
2738 lock_extent(tree
, start
, end
);
2739 ordered
= btrfs_lookup_ordered_extent(inode
, start
);
2742 unlock_extent(tree
, start
, end
);
2743 btrfs_start_ordered_extent(inode
, ordered
, 1);
2744 btrfs_put_ordered_extent(ordered
);
2747 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
2749 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
2752 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
2753 userpage
= kmap_atomic(page
);
2754 memset(userpage
+ zero_offset
, 0, iosize
);
2755 flush_dcache_page(page
);
2756 kunmap_atomic(userpage
);
2759 while (cur
<= end
) {
2760 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2762 if (cur
>= last_byte
) {
2764 struct extent_state
*cached
= NULL
;
2766 iosize
= PAGE_CACHE_SIZE
- pg_offset
;
2767 userpage
= kmap_atomic(page
);
2768 memset(userpage
+ pg_offset
, 0, iosize
);
2769 flush_dcache_page(page
);
2770 kunmap_atomic(userpage
);
2771 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2773 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2777 em
= get_extent(inode
, page
, pg_offset
, cur
,
2779 if (IS_ERR_OR_NULL(em
)) {
2781 unlock_extent(tree
, cur
, end
);
2784 extent_offset
= cur
- em
->start
;
2785 BUG_ON(extent_map_end(em
) <= cur
);
2788 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2789 this_bio_flag
= EXTENT_BIO_COMPRESSED
;
2790 extent_set_compress_type(&this_bio_flag
,
2794 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2795 cur_end
= min(extent_map_end(em
) - 1, end
);
2796 iosize
= ALIGN(iosize
, blocksize
);
2797 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2798 disk_io_size
= em
->block_len
;
2799 sector
= em
->block_start
>> 9;
2801 sector
= (em
->block_start
+ extent_offset
) >> 9;
2802 disk_io_size
= iosize
;
2805 block_start
= em
->block_start
;
2806 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2807 block_start
= EXTENT_MAP_HOLE
;
2808 free_extent_map(em
);
2811 /* we've found a hole, just zero and go on */
2812 if (block_start
== EXTENT_MAP_HOLE
) {
2814 struct extent_state
*cached
= NULL
;
2816 userpage
= kmap_atomic(page
);
2817 memset(userpage
+ pg_offset
, 0, iosize
);
2818 flush_dcache_page(page
);
2819 kunmap_atomic(userpage
);
2821 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2823 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2826 pg_offset
+= iosize
;
2829 /* the get_extent function already copied into the page */
2830 if (test_range_bit(tree
, cur
, cur_end
,
2831 EXTENT_UPTODATE
, 1, NULL
)) {
2832 check_page_uptodate(tree
, page
);
2833 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2835 pg_offset
+= iosize
;
2838 /* we have an inline extent but it didn't get marked up
2839 * to date. Error out
2841 if (block_start
== EXTENT_MAP_INLINE
) {
2843 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2845 pg_offset
+= iosize
;
2850 ret
= submit_extent_page(rw
, tree
, page
,
2851 sector
, disk_io_size
, pg_offset
,
2853 end_bio_extent_readpage
, mirror_num
,
2858 *bio_flags
= this_bio_flag
;
2861 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
2864 pg_offset
+= iosize
;
2868 if (!PageError(page
))
2869 SetPageUptodate(page
);
2875 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2876 get_extent_t
*get_extent
, int mirror_num
)
2878 struct bio
*bio
= NULL
;
2879 unsigned long bio_flags
= 0;
2882 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
2885 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
2889 static noinline
void update_nr_written(struct page
*page
,
2890 struct writeback_control
*wbc
,
2891 unsigned long nr_written
)
2893 wbc
->nr_to_write
-= nr_written
;
2894 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
2895 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
2896 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
2900 * the writepage semantics are similar to regular writepage. extent
2901 * records are inserted to lock ranges in the tree, and as dirty areas
2902 * are found, they are marked writeback. Then the lock bits are removed
2903 * and the end_io handler clears the writeback ranges
2905 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
2908 struct inode
*inode
= page
->mapping
->host
;
2909 struct extent_page_data
*epd
= data
;
2910 struct extent_io_tree
*tree
= epd
->tree
;
2911 u64 start
= page_offset(page
);
2913 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2917 u64 last_byte
= i_size_read(inode
);
2921 struct extent_state
*cached_state
= NULL
;
2922 struct extent_map
*em
;
2923 struct block_device
*bdev
;
2926 size_t pg_offset
= 0;
2928 loff_t i_size
= i_size_read(inode
);
2929 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2935 unsigned long nr_written
= 0;
2936 bool fill_delalloc
= true;
2938 if (wbc
->sync_mode
== WB_SYNC_ALL
)
2939 write_flags
= WRITE_SYNC
;
2941 write_flags
= WRITE
;
2943 trace___extent_writepage(page
, inode
, wbc
);
2945 WARN_ON(!PageLocked(page
));
2947 ClearPageError(page
);
2949 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
2950 if (page
->index
> end_index
||
2951 (page
->index
== end_index
&& !pg_offset
)) {
2952 page
->mapping
->a_ops
->invalidatepage(page
, 0);
2957 if (page
->index
== end_index
) {
2960 userpage
= kmap_atomic(page
);
2961 memset(userpage
+ pg_offset
, 0,
2962 PAGE_CACHE_SIZE
- pg_offset
);
2963 kunmap_atomic(userpage
);
2964 flush_dcache_page(page
);
2968 set_page_extent_mapped(page
);
2970 if (!tree
->ops
|| !tree
->ops
->fill_delalloc
)
2971 fill_delalloc
= false;
2973 delalloc_start
= start
;
2976 if (!epd
->extent_locked
&& fill_delalloc
) {
2977 u64 delalloc_to_write
= 0;
2979 * make sure the wbc mapping index is at least updated
2982 update_nr_written(page
, wbc
, 0);
2984 while (delalloc_end
< page_end
) {
2985 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
2990 if (nr_delalloc
== 0) {
2991 delalloc_start
= delalloc_end
+ 1;
2994 ret
= tree
->ops
->fill_delalloc(inode
, page
,
2999 /* File system has been set read-only */
3005 * delalloc_end is already one less than the total
3006 * length, so we don't subtract one from
3009 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3012 delalloc_start
= delalloc_end
+ 1;
3014 if (wbc
->nr_to_write
< delalloc_to_write
) {
3017 if (delalloc_to_write
< thresh
* 2)
3018 thresh
= delalloc_to_write
;
3019 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3023 /* did the fill delalloc function already unlock and start
3029 * we've unlocked the page, so we can't update
3030 * the mapping's writeback index, just update
3033 wbc
->nr_to_write
-= nr_written
;
3037 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3038 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3041 /* Fixup worker will requeue */
3043 wbc
->pages_skipped
++;
3045 redirty_page_for_writepage(wbc
, page
);
3046 update_nr_written(page
, wbc
, nr_written
);
3054 * we don't want to touch the inode after unlocking the page,
3055 * so we update the mapping writeback index now
3057 update_nr_written(page
, wbc
, nr_written
+ 1);
3060 if (last_byte
<= start
) {
3061 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3062 tree
->ops
->writepage_end_io_hook(page
, start
,
3067 blocksize
= inode
->i_sb
->s_blocksize
;
3069 while (cur
<= end
) {
3070 if (cur
>= last_byte
) {
3071 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3072 tree
->ops
->writepage_end_io_hook(page
, cur
,
3076 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
3078 if (IS_ERR_OR_NULL(em
)) {
3083 extent_offset
= cur
- em
->start
;
3084 BUG_ON(extent_map_end(em
) <= cur
);
3086 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
3087 iosize
= ALIGN(iosize
, blocksize
);
3088 sector
= (em
->block_start
+ extent_offset
) >> 9;
3090 block_start
= em
->block_start
;
3091 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3092 free_extent_map(em
);
3096 * compressed and inline extents are written through other
3099 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3100 block_start
== EXTENT_MAP_INLINE
) {
3102 * end_io notification does not happen here for
3103 * compressed extents
3105 if (!compressed
&& tree
->ops
&&
3106 tree
->ops
->writepage_end_io_hook
)
3107 tree
->ops
->writepage_end_io_hook(page
, cur
,
3110 else if (compressed
) {
3111 /* we don't want to end_page_writeback on
3112 * a compressed extent. this happens
3119 pg_offset
+= iosize
;
3122 /* leave this out until we have a page_mkwrite call */
3123 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
3124 EXTENT_DIRTY
, 0, NULL
)) {
3126 pg_offset
+= iosize
;
3130 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
3131 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
3139 unsigned long max_nr
= end_index
+ 1;
3141 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3142 if (!PageWriteback(page
)) {
3143 printk(KERN_ERR
"btrfs warning page %lu not "
3144 "writeback, cur %llu end %llu\n",
3145 page
->index
, (unsigned long long)cur
,
3146 (unsigned long long)end
);
3149 ret
= submit_extent_page(write_flags
, tree
, page
,
3150 sector
, iosize
, pg_offset
,
3151 bdev
, &epd
->bio
, max_nr
,
3152 end_bio_extent_writepage
,
3158 pg_offset
+= iosize
;
3163 /* make sure the mapping tag for page dirty gets cleared */
3164 set_page_writeback(page
);
3165 end_page_writeback(page
);
3171 /* drop our reference on any cached states */
3172 free_extent_state(cached_state
);
3176 static int eb_wait(void *word
)
3182 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3184 wait_on_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
, eb_wait
,
3185 TASK_UNINTERRUPTIBLE
);
3188 static int lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3189 struct btrfs_fs_info
*fs_info
,
3190 struct extent_page_data
*epd
)
3192 unsigned long i
, num_pages
;
3196 if (!btrfs_try_tree_write_lock(eb
)) {
3198 flush_write_bio(epd
);
3199 btrfs_tree_lock(eb
);
3202 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3203 btrfs_tree_unlock(eb
);
3207 flush_write_bio(epd
);
3211 wait_on_extent_buffer_writeback(eb
);
3212 btrfs_tree_lock(eb
);
3213 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3215 btrfs_tree_unlock(eb
);
3220 * We need to do this to prevent races in people who check if the eb is
3221 * under IO since we can end up having no IO bits set for a short period
3224 spin_lock(&eb
->refs_lock
);
3225 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3226 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3227 spin_unlock(&eb
->refs_lock
);
3228 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3229 __percpu_counter_add(&fs_info
->dirty_metadata_bytes
,
3231 fs_info
->dirty_metadata_batch
);
3234 spin_unlock(&eb
->refs_lock
);
3237 btrfs_tree_unlock(eb
);
3242 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3243 for (i
= 0; i
< num_pages
; i
++) {
3244 struct page
*p
= extent_buffer_page(eb
, i
);
3246 if (!trylock_page(p
)) {
3248 flush_write_bio(epd
);
3258 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3260 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3261 smp_mb__after_clear_bit();
3262 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3265 static void end_bio_extent_buffer_writepage(struct bio
*bio
, int err
)
3267 int uptodate
= err
== 0;
3268 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
3269 struct extent_buffer
*eb
;
3273 struct page
*page
= bvec
->bv_page
;
3276 eb
= (struct extent_buffer
*)page
->private;
3278 done
= atomic_dec_and_test(&eb
->io_pages
);
3280 if (!uptodate
|| test_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
)) {
3281 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3282 ClearPageUptodate(page
);
3286 end_page_writeback(page
);
3291 end_extent_buffer_writeback(eb
);
3292 } while (bvec
>= bio
->bi_io_vec
);
3298 static int write_one_eb(struct extent_buffer
*eb
,
3299 struct btrfs_fs_info
*fs_info
,
3300 struct writeback_control
*wbc
,
3301 struct extent_page_data
*epd
)
3303 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3304 u64 offset
= eb
->start
;
3305 unsigned long i
, num_pages
;
3306 unsigned long bio_flags
= 0;
3307 int rw
= (epd
->sync_io
? WRITE_SYNC
: WRITE
) | REQ_META
;
3310 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3311 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3312 atomic_set(&eb
->io_pages
, num_pages
);
3313 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3314 bio_flags
= EXTENT_BIO_TREE_LOG
;
3316 for (i
= 0; i
< num_pages
; i
++) {
3317 struct page
*p
= extent_buffer_page(eb
, i
);
3319 clear_page_dirty_for_io(p
);
3320 set_page_writeback(p
);
3321 ret
= submit_extent_page(rw
, eb
->tree
, p
, offset
>> 9,
3322 PAGE_CACHE_SIZE
, 0, bdev
, &epd
->bio
,
3323 -1, end_bio_extent_buffer_writepage
,
3324 0, epd
->bio_flags
, bio_flags
);
3325 epd
->bio_flags
= bio_flags
;
3327 set_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
3329 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3330 end_extent_buffer_writeback(eb
);
3334 offset
+= PAGE_CACHE_SIZE
;
3335 update_nr_written(p
, wbc
, 1);
3339 if (unlikely(ret
)) {
3340 for (; i
< num_pages
; i
++) {
3341 struct page
*p
= extent_buffer_page(eb
, i
);
3349 int btree_write_cache_pages(struct address_space
*mapping
,
3350 struct writeback_control
*wbc
)
3352 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3353 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3354 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3355 struct extent_page_data epd
= {
3359 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3364 int nr_to_write_done
= 0;
3365 struct pagevec pvec
;
3368 pgoff_t end
; /* Inclusive */
3372 pagevec_init(&pvec
, 0);
3373 if (wbc
->range_cyclic
) {
3374 index
= mapping
->writeback_index
; /* Start from prev offset */
3377 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3378 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3381 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3382 tag
= PAGECACHE_TAG_TOWRITE
;
3384 tag
= PAGECACHE_TAG_DIRTY
;
3386 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3387 tag_pages_for_writeback(mapping
, index
, end
);
3388 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3389 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3390 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3394 for (i
= 0; i
< nr_pages
; i
++) {
3395 struct page
*page
= pvec
.pages
[i
];
3397 if (!PagePrivate(page
))
3400 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3405 spin_lock(&mapping
->private_lock
);
3406 if (!PagePrivate(page
)) {
3407 spin_unlock(&mapping
->private_lock
);
3411 eb
= (struct extent_buffer
*)page
->private;
3414 * Shouldn't happen and normally this would be a BUG_ON
3415 * but no sense in crashing the users box for something
3416 * we can survive anyway.
3419 spin_unlock(&mapping
->private_lock
);
3424 if (eb
== prev_eb
) {
3425 spin_unlock(&mapping
->private_lock
);
3429 ret
= atomic_inc_not_zero(&eb
->refs
);
3430 spin_unlock(&mapping
->private_lock
);
3435 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3437 free_extent_buffer(eb
);
3441 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3444 free_extent_buffer(eb
);
3447 free_extent_buffer(eb
);
3450 * the filesystem may choose to bump up nr_to_write.
3451 * We have to make sure to honor the new nr_to_write
3454 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3456 pagevec_release(&pvec
);
3459 if (!scanned
&& !done
) {
3461 * We hit the last page and there is more work to be done: wrap
3462 * back to the start of the file
3468 flush_write_bio(&epd
);
3473 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3474 * @mapping: address space structure to write
3475 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3476 * @writepage: function called for each page
3477 * @data: data passed to writepage function
3479 * If a page is already under I/O, write_cache_pages() skips it, even
3480 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3481 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3482 * and msync() need to guarantee that all the data which was dirty at the time
3483 * the call was made get new I/O started against them. If wbc->sync_mode is
3484 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3485 * existing IO to complete.
3487 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
3488 struct address_space
*mapping
,
3489 struct writeback_control
*wbc
,
3490 writepage_t writepage
, void *data
,
3491 void (*flush_fn
)(void *))
3493 struct inode
*inode
= mapping
->host
;
3496 int nr_to_write_done
= 0;
3497 struct pagevec pvec
;
3500 pgoff_t end
; /* Inclusive */
3505 * We have to hold onto the inode so that ordered extents can do their
3506 * work when the IO finishes. The alternative to this is failing to add
3507 * an ordered extent if the igrab() fails there and that is a huge pain
3508 * to deal with, so instead just hold onto the inode throughout the
3509 * writepages operation. If it fails here we are freeing up the inode
3510 * anyway and we'd rather not waste our time writing out stuff that is
3511 * going to be truncated anyway.
3516 pagevec_init(&pvec
, 0);
3517 if (wbc
->range_cyclic
) {
3518 index
= mapping
->writeback_index
; /* Start from prev offset */
3521 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3522 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3525 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3526 tag
= PAGECACHE_TAG_TOWRITE
;
3528 tag
= PAGECACHE_TAG_DIRTY
;
3530 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3531 tag_pages_for_writeback(mapping
, index
, end
);
3532 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3533 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3534 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3538 for (i
= 0; i
< nr_pages
; i
++) {
3539 struct page
*page
= pvec
.pages
[i
];
3542 * At this point we hold neither mapping->tree_lock nor
3543 * lock on the page itself: the page may be truncated or
3544 * invalidated (changing page->mapping to NULL), or even
3545 * swizzled back from swapper_space to tmpfs file
3548 if (!trylock_page(page
)) {
3553 if (unlikely(page
->mapping
!= mapping
)) {
3558 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3564 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
3565 if (PageWriteback(page
))
3567 wait_on_page_writeback(page
);
3570 if (PageWriteback(page
) ||
3571 !clear_page_dirty_for_io(page
)) {
3576 ret
= (*writepage
)(page
, wbc
, data
);
3578 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
3586 * the filesystem may choose to bump up nr_to_write.
3587 * We have to make sure to honor the new nr_to_write
3590 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3592 pagevec_release(&pvec
);
3595 if (!scanned
&& !done
) {
3597 * We hit the last page and there is more work to be done: wrap
3598 * back to the start of the file
3604 btrfs_add_delayed_iput(inode
);
3608 static void flush_epd_write_bio(struct extent_page_data
*epd
)
3617 ret
= submit_one_bio(rw
, epd
->bio
, 0, epd
->bio_flags
);
3618 BUG_ON(ret
< 0); /* -ENOMEM */
3623 static noinline
void flush_write_bio(void *data
)
3625 struct extent_page_data
*epd
= data
;
3626 flush_epd_write_bio(epd
);
3629 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3630 get_extent_t
*get_extent
,
3631 struct writeback_control
*wbc
)
3634 struct extent_page_data epd
= {
3637 .get_extent
= get_extent
,
3639 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3643 ret
= __extent_writepage(page
, wbc
, &epd
);
3645 flush_epd_write_bio(&epd
);
3649 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
3650 u64 start
, u64 end
, get_extent_t
*get_extent
,
3654 struct address_space
*mapping
= inode
->i_mapping
;
3656 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
3659 struct extent_page_data epd
= {
3662 .get_extent
= get_extent
,
3664 .sync_io
= mode
== WB_SYNC_ALL
,
3667 struct writeback_control wbc_writepages
= {
3669 .nr_to_write
= nr_pages
* 2,
3670 .range_start
= start
,
3671 .range_end
= end
+ 1,
3674 while (start
<= end
) {
3675 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
3676 if (clear_page_dirty_for_io(page
))
3677 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
3679 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3680 tree
->ops
->writepage_end_io_hook(page
, start
,
3681 start
+ PAGE_CACHE_SIZE
- 1,
3685 page_cache_release(page
);
3686 start
+= PAGE_CACHE_SIZE
;
3689 flush_epd_write_bio(&epd
);
3693 int extent_writepages(struct extent_io_tree
*tree
,
3694 struct address_space
*mapping
,
3695 get_extent_t
*get_extent
,
3696 struct writeback_control
*wbc
)
3699 struct extent_page_data epd
= {
3702 .get_extent
= get_extent
,
3704 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3708 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
3709 __extent_writepage
, &epd
,
3711 flush_epd_write_bio(&epd
);
3715 int extent_readpages(struct extent_io_tree
*tree
,
3716 struct address_space
*mapping
,
3717 struct list_head
*pages
, unsigned nr_pages
,
3718 get_extent_t get_extent
)
3720 struct bio
*bio
= NULL
;
3722 unsigned long bio_flags
= 0;
3723 struct page
*pagepool
[16];
3728 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
3729 page
= list_entry(pages
->prev
, struct page
, lru
);
3731 prefetchw(&page
->flags
);
3732 list_del(&page
->lru
);
3733 if (add_to_page_cache_lru(page
, mapping
,
3734 page
->index
, GFP_NOFS
)) {
3735 page_cache_release(page
);
3739 pagepool
[nr
++] = page
;
3740 if (nr
< ARRAY_SIZE(pagepool
))
3742 for (i
= 0; i
< nr
; i
++) {
3743 __extent_read_full_page(tree
, pagepool
[i
], get_extent
,
3744 &bio
, 0, &bio_flags
, READ
);
3745 page_cache_release(pagepool
[i
]);
3749 for (i
= 0; i
< nr
; i
++) {
3750 __extent_read_full_page(tree
, pagepool
[i
], get_extent
,
3751 &bio
, 0, &bio_flags
, READ
);
3752 page_cache_release(pagepool
[i
]);
3755 BUG_ON(!list_empty(pages
));
3757 return submit_one_bio(READ
, bio
, 0, bio_flags
);
3762 * basic invalidatepage code, this waits on any locked or writeback
3763 * ranges corresponding to the page, and then deletes any extent state
3764 * records from the tree
3766 int extent_invalidatepage(struct extent_io_tree
*tree
,
3767 struct page
*page
, unsigned long offset
)
3769 struct extent_state
*cached_state
= NULL
;
3770 u64 start
= page_offset(page
);
3771 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3772 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
3774 start
+= ALIGN(offset
, blocksize
);
3778 lock_extent_bits(tree
, start
, end
, 0, &cached_state
);
3779 wait_on_page_writeback(page
);
3780 clear_extent_bit(tree
, start
, end
,
3781 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
3782 EXTENT_DO_ACCOUNTING
,
3783 1, 1, &cached_state
, GFP_NOFS
);
3788 * a helper for releasepage, this tests for areas of the page that
3789 * are locked or under IO and drops the related state bits if it is safe
3792 static int try_release_extent_state(struct extent_map_tree
*map
,
3793 struct extent_io_tree
*tree
,
3794 struct page
*page
, gfp_t mask
)
3796 u64 start
= page_offset(page
);
3797 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3800 if (test_range_bit(tree
, start
, end
,
3801 EXTENT_IOBITS
, 0, NULL
))
3804 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
3807 * at this point we can safely clear everything except the
3808 * locked bit and the nodatasum bit
3810 ret
= clear_extent_bit(tree
, start
, end
,
3811 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
3814 /* if clear_extent_bit failed for enomem reasons,
3815 * we can't allow the release to continue.
3826 * a helper for releasepage. As long as there are no locked extents
3827 * in the range corresponding to the page, both state records and extent
3828 * map records are removed
3830 int try_release_extent_mapping(struct extent_map_tree
*map
,
3831 struct extent_io_tree
*tree
, struct page
*page
,
3834 struct extent_map
*em
;
3835 u64 start
= page_offset(page
);
3836 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3838 if ((mask
& __GFP_WAIT
) &&
3839 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
3841 while (start
<= end
) {
3842 len
= end
- start
+ 1;
3843 write_lock(&map
->lock
);
3844 em
= lookup_extent_mapping(map
, start
, len
);
3846 write_unlock(&map
->lock
);
3849 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
3850 em
->start
!= start
) {
3851 write_unlock(&map
->lock
);
3852 free_extent_map(em
);
3855 if (!test_range_bit(tree
, em
->start
,
3856 extent_map_end(em
) - 1,
3857 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
3859 remove_extent_mapping(map
, em
);
3860 /* once for the rb tree */
3861 free_extent_map(em
);
3863 start
= extent_map_end(em
);
3864 write_unlock(&map
->lock
);
3867 free_extent_map(em
);
3870 return try_release_extent_state(map
, tree
, page
, mask
);
3874 * helper function for fiemap, which doesn't want to see any holes.
3875 * This maps until we find something past 'last'
3877 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
3880 get_extent_t
*get_extent
)
3882 u64 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
3883 struct extent_map
*em
;
3890 len
= last
- offset
;
3893 len
= ALIGN(len
, sectorsize
);
3894 em
= get_extent(inode
, NULL
, 0, offset
, len
, 0);
3895 if (IS_ERR_OR_NULL(em
))
3898 /* if this isn't a hole return it */
3899 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
3900 em
->block_start
!= EXTENT_MAP_HOLE
) {
3904 /* this is a hole, advance to the next extent */
3905 offset
= extent_map_end(em
);
3906 free_extent_map(em
);
3913 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
3914 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
3918 u64 max
= start
+ len
;
3922 u64 last_for_get_extent
= 0;
3924 u64 isize
= i_size_read(inode
);
3925 struct btrfs_key found_key
;
3926 struct extent_map
*em
= NULL
;
3927 struct extent_state
*cached_state
= NULL
;
3928 struct btrfs_path
*path
;
3929 struct btrfs_file_extent_item
*item
;
3934 unsigned long emflags
;
3939 path
= btrfs_alloc_path();
3942 path
->leave_spinning
= 1;
3944 start
= ALIGN(start
, BTRFS_I(inode
)->root
->sectorsize
);
3945 len
= ALIGN(len
, BTRFS_I(inode
)->root
->sectorsize
);
3948 * lookup the last file extent. We're not using i_size here
3949 * because there might be preallocation past i_size
3951 ret
= btrfs_lookup_file_extent(NULL
, BTRFS_I(inode
)->root
,
3952 path
, btrfs_ino(inode
), -1, 0);
3954 btrfs_free_path(path
);
3959 item
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3960 struct btrfs_file_extent_item
);
3961 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
3962 found_type
= btrfs_key_type(&found_key
);
3964 /* No extents, but there might be delalloc bits */
3965 if (found_key
.objectid
!= btrfs_ino(inode
) ||
3966 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
3967 /* have to trust i_size as the end */
3969 last_for_get_extent
= isize
;
3972 * remember the start of the last extent. There are a
3973 * bunch of different factors that go into the length of the
3974 * extent, so its much less complex to remember where it started
3976 last
= found_key
.offset
;
3977 last_for_get_extent
= last
+ 1;
3979 btrfs_free_path(path
);
3982 * we might have some extents allocated but more delalloc past those
3983 * extents. so, we trust isize unless the start of the last extent is
3988 last_for_get_extent
= isize
;
3991 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
, 0,
3994 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4004 u64 offset_in_extent
;
4006 /* break if the extent we found is outside the range */
4007 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4011 * get_extent may return an extent that starts before our
4012 * requested range. We have to make sure the ranges
4013 * we return to fiemap always move forward and don't
4014 * overlap, so adjust the offsets here
4016 em_start
= max(em
->start
, off
);
4019 * record the offset from the start of the extent
4020 * for adjusting the disk offset below
4022 offset_in_extent
= em_start
- em
->start
;
4023 em_end
= extent_map_end(em
);
4024 em_len
= em_end
- em_start
;
4025 emflags
= em
->flags
;
4030 * bump off for our next call to get_extent
4032 off
= extent_map_end(em
);
4036 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4038 flags
|= FIEMAP_EXTENT_LAST
;
4039 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4040 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4041 FIEMAP_EXTENT_NOT_ALIGNED
);
4042 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4043 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4044 FIEMAP_EXTENT_UNKNOWN
);
4046 disko
= em
->block_start
+ offset_in_extent
;
4048 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4049 flags
|= FIEMAP_EXTENT_ENCODED
;
4051 free_extent_map(em
);
4053 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4054 (last
== (u64
)-1 && isize
<= em_end
)) {
4055 flags
|= FIEMAP_EXTENT_LAST
;
4059 /* now scan forward to see if this is really the last extent. */
4060 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4067 flags
|= FIEMAP_EXTENT_LAST
;
4070 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
4076 free_extent_map(em
);
4078 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
,
4079 &cached_state
, GFP_NOFS
);
4083 static void __free_extent_buffer(struct extent_buffer
*eb
)
4085 btrfs_leak_debug_del(&eb
->leak_list
);
4086 kmem_cache_free(extent_buffer_cache
, eb
);
4089 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
4094 struct extent_buffer
*eb
= NULL
;
4096 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
4103 rwlock_init(&eb
->lock
);
4104 atomic_set(&eb
->write_locks
, 0);
4105 atomic_set(&eb
->read_locks
, 0);
4106 atomic_set(&eb
->blocking_readers
, 0);
4107 atomic_set(&eb
->blocking_writers
, 0);
4108 atomic_set(&eb
->spinning_readers
, 0);
4109 atomic_set(&eb
->spinning_writers
, 0);
4110 eb
->lock_nested
= 0;
4111 init_waitqueue_head(&eb
->write_lock_wq
);
4112 init_waitqueue_head(&eb
->read_lock_wq
);
4114 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4116 spin_lock_init(&eb
->refs_lock
);
4117 atomic_set(&eb
->refs
, 1);
4118 atomic_set(&eb
->io_pages
, 0);
4121 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4123 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4124 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4125 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4130 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4134 struct extent_buffer
*new;
4135 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4137 new = __alloc_extent_buffer(NULL
, src
->start
, src
->len
, GFP_ATOMIC
);
4141 for (i
= 0; i
< num_pages
; i
++) {
4142 p
= alloc_page(GFP_ATOMIC
);
4144 attach_extent_buffer_page(new, p
);
4145 WARN_ON(PageDirty(p
));
4150 copy_extent_buffer(new, src
, 0, 0, src
->len
);
4151 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4152 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4157 struct extent_buffer
*alloc_dummy_extent_buffer(u64 start
, unsigned long len
)
4159 struct extent_buffer
*eb
;
4160 unsigned long num_pages
= num_extent_pages(0, len
);
4163 eb
= __alloc_extent_buffer(NULL
, start
, len
, GFP_ATOMIC
);
4167 for (i
= 0; i
< num_pages
; i
++) {
4168 eb
->pages
[i
] = alloc_page(GFP_ATOMIC
);
4172 set_extent_buffer_uptodate(eb
);
4173 btrfs_set_header_nritems(eb
, 0);
4174 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4179 __free_page(eb
->pages
[i
- 1]);
4180 __free_extent_buffer(eb
);
4184 static int extent_buffer_under_io(struct extent_buffer
*eb
)
4186 return (atomic_read(&eb
->io_pages
) ||
4187 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4188 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4192 * Helper for releasing extent buffer page.
4194 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
,
4195 unsigned long start_idx
)
4197 unsigned long index
;
4198 unsigned long num_pages
;
4200 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4202 BUG_ON(extent_buffer_under_io(eb
));
4204 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4205 index
= start_idx
+ num_pages
;
4206 if (start_idx
>= index
)
4211 page
= extent_buffer_page(eb
, index
);
4212 if (page
&& mapped
) {
4213 spin_lock(&page
->mapping
->private_lock
);
4215 * We do this since we'll remove the pages after we've
4216 * removed the eb from the radix tree, so we could race
4217 * and have this page now attached to the new eb. So
4218 * only clear page_private if it's still connected to
4221 if (PagePrivate(page
) &&
4222 page
->private == (unsigned long)eb
) {
4223 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4224 BUG_ON(PageDirty(page
));
4225 BUG_ON(PageWriteback(page
));
4227 * We need to make sure we haven't be attached
4230 ClearPagePrivate(page
);
4231 set_page_private(page
, 0);
4232 /* One for the page private */
4233 page_cache_release(page
);
4235 spin_unlock(&page
->mapping
->private_lock
);
4239 /* One for when we alloced the page */
4240 page_cache_release(page
);
4242 } while (index
!= start_idx
);
4246 * Helper for releasing the extent buffer.
4248 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4250 btrfs_release_extent_buffer_page(eb
, 0);
4251 __free_extent_buffer(eb
);
4254 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4257 /* the ref bit is tricky. We have to make sure it is set
4258 * if we have the buffer dirty. Otherwise the
4259 * code to free a buffer can end up dropping a dirty
4262 * Once the ref bit is set, it won't go away while the
4263 * buffer is dirty or in writeback, and it also won't
4264 * go away while we have the reference count on the
4267 * We can't just set the ref bit without bumping the
4268 * ref on the eb because free_extent_buffer might
4269 * see the ref bit and try to clear it. If this happens
4270 * free_extent_buffer might end up dropping our original
4271 * ref by mistake and freeing the page before we are able
4272 * to add one more ref.
4274 * So bump the ref count first, then set the bit. If someone
4275 * beat us to it, drop the ref we added.
4277 refs
= atomic_read(&eb
->refs
);
4278 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4281 spin_lock(&eb
->refs_lock
);
4282 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4283 atomic_inc(&eb
->refs
);
4284 spin_unlock(&eb
->refs_lock
);
4287 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
)
4289 unsigned long num_pages
, i
;
4291 check_buffer_tree_ref(eb
);
4293 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4294 for (i
= 0; i
< num_pages
; i
++) {
4295 struct page
*p
= extent_buffer_page(eb
, i
);
4296 mark_page_accessed(p
);
4300 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
4301 u64 start
, unsigned long len
)
4303 unsigned long num_pages
= num_extent_pages(start
, len
);
4305 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
4306 struct extent_buffer
*eb
;
4307 struct extent_buffer
*exists
= NULL
;
4309 struct address_space
*mapping
= tree
->mapping
;
4314 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4315 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4317 mark_extent_buffer_accessed(eb
);
4322 eb
= __alloc_extent_buffer(tree
, start
, len
, GFP_NOFS
);
4326 for (i
= 0; i
< num_pages
; i
++, index
++) {
4327 p
= find_or_create_page(mapping
, index
, GFP_NOFS
);
4331 spin_lock(&mapping
->private_lock
);
4332 if (PagePrivate(p
)) {
4334 * We could have already allocated an eb for this page
4335 * and attached one so lets see if we can get a ref on
4336 * the existing eb, and if we can we know it's good and
4337 * we can just return that one, else we know we can just
4338 * overwrite page->private.
4340 exists
= (struct extent_buffer
*)p
->private;
4341 if (atomic_inc_not_zero(&exists
->refs
)) {
4342 spin_unlock(&mapping
->private_lock
);
4344 page_cache_release(p
);
4345 mark_extent_buffer_accessed(exists
);
4350 * Do this so attach doesn't complain and we need to
4351 * drop the ref the old guy had.
4353 ClearPagePrivate(p
);
4354 WARN_ON(PageDirty(p
));
4355 page_cache_release(p
);
4357 attach_extent_buffer_page(eb
, p
);
4358 spin_unlock(&mapping
->private_lock
);
4359 WARN_ON(PageDirty(p
));
4360 mark_page_accessed(p
);
4362 if (!PageUptodate(p
))
4366 * see below about how we avoid a nasty race with release page
4367 * and why we unlock later
4371 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4373 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
4377 spin_lock(&tree
->buffer_lock
);
4378 ret
= radix_tree_insert(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
, eb
);
4379 if (ret
== -EEXIST
) {
4380 exists
= radix_tree_lookup(&tree
->buffer
,
4381 start
>> PAGE_CACHE_SHIFT
);
4382 if (!atomic_inc_not_zero(&exists
->refs
)) {
4383 spin_unlock(&tree
->buffer_lock
);
4384 radix_tree_preload_end();
4388 spin_unlock(&tree
->buffer_lock
);
4389 radix_tree_preload_end();
4390 mark_extent_buffer_accessed(exists
);
4393 /* add one reference for the tree */
4394 check_buffer_tree_ref(eb
);
4395 spin_unlock(&tree
->buffer_lock
);
4396 radix_tree_preload_end();
4399 * there is a race where release page may have
4400 * tried to find this extent buffer in the radix
4401 * but failed. It will tell the VM it is safe to
4402 * reclaim the, and it will clear the page private bit.
4403 * We must make sure to set the page private bit properly
4404 * after the extent buffer is in the radix tree so
4405 * it doesn't get lost
4407 SetPageChecked(eb
->pages
[0]);
4408 for (i
= 1; i
< num_pages
; i
++) {
4409 p
= extent_buffer_page(eb
, i
);
4410 ClearPageChecked(p
);
4413 unlock_page(eb
->pages
[0]);
4417 for (i
= 0; i
< num_pages
; i
++) {
4419 unlock_page(eb
->pages
[i
]);
4422 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
4423 btrfs_release_extent_buffer(eb
);
4427 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
4428 u64 start
, unsigned long len
)
4430 struct extent_buffer
*eb
;
4433 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4434 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4436 mark_extent_buffer_accessed(eb
);
4444 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
4446 struct extent_buffer
*eb
=
4447 container_of(head
, struct extent_buffer
, rcu_head
);
4449 __free_extent_buffer(eb
);
4452 /* Expects to have eb->eb_lock already held */
4453 static int release_extent_buffer(struct extent_buffer
*eb
)
4455 WARN_ON(atomic_read(&eb
->refs
) == 0);
4456 if (atomic_dec_and_test(&eb
->refs
)) {
4457 if (test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
)) {
4458 spin_unlock(&eb
->refs_lock
);
4460 struct extent_io_tree
*tree
= eb
->tree
;
4462 spin_unlock(&eb
->refs_lock
);
4464 spin_lock(&tree
->buffer_lock
);
4465 radix_tree_delete(&tree
->buffer
,
4466 eb
->start
>> PAGE_CACHE_SHIFT
);
4467 spin_unlock(&tree
->buffer_lock
);
4470 /* Should be safe to release our pages at this point */
4471 btrfs_release_extent_buffer_page(eb
, 0);
4472 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
4475 spin_unlock(&eb
->refs_lock
);
4480 void free_extent_buffer(struct extent_buffer
*eb
)
4488 refs
= atomic_read(&eb
->refs
);
4491 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
4496 spin_lock(&eb
->refs_lock
);
4497 if (atomic_read(&eb
->refs
) == 2 &&
4498 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
4499 atomic_dec(&eb
->refs
);
4501 if (atomic_read(&eb
->refs
) == 2 &&
4502 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
4503 !extent_buffer_under_io(eb
) &&
4504 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4505 atomic_dec(&eb
->refs
);
4508 * I know this is terrible, but it's temporary until we stop tracking
4509 * the uptodate bits and such for the extent buffers.
4511 release_extent_buffer(eb
);
4514 void free_extent_buffer_stale(struct extent_buffer
*eb
)
4519 spin_lock(&eb
->refs_lock
);
4520 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
4522 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
4523 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4524 atomic_dec(&eb
->refs
);
4525 release_extent_buffer(eb
);
4528 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
4531 unsigned long num_pages
;
4534 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4536 for (i
= 0; i
< num_pages
; i
++) {
4537 page
= extent_buffer_page(eb
, i
);
4538 if (!PageDirty(page
))
4542 WARN_ON(!PagePrivate(page
));
4544 clear_page_dirty_for_io(page
);
4545 spin_lock_irq(&page
->mapping
->tree_lock
);
4546 if (!PageDirty(page
)) {
4547 radix_tree_tag_clear(&page
->mapping
->page_tree
,
4549 PAGECACHE_TAG_DIRTY
);
4551 spin_unlock_irq(&page
->mapping
->tree_lock
);
4552 ClearPageError(page
);
4555 WARN_ON(atomic_read(&eb
->refs
) == 0);
4558 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
4561 unsigned long num_pages
;
4564 check_buffer_tree_ref(eb
);
4566 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
4568 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4569 WARN_ON(atomic_read(&eb
->refs
) == 0);
4570 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
4572 for (i
= 0; i
< num_pages
; i
++)
4573 set_page_dirty(extent_buffer_page(eb
, i
));
4577 int clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
4581 unsigned long num_pages
;
4583 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4584 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4585 for (i
= 0; i
< num_pages
; i
++) {
4586 page
= extent_buffer_page(eb
, i
);
4588 ClearPageUptodate(page
);
4593 int set_extent_buffer_uptodate(struct extent_buffer
*eb
)
4597 unsigned long num_pages
;
4599 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4600 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4601 for (i
= 0; i
< num_pages
; i
++) {
4602 page
= extent_buffer_page(eb
, i
);
4603 SetPageUptodate(page
);
4608 int extent_buffer_uptodate(struct extent_buffer
*eb
)
4610 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4613 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
4614 struct extent_buffer
*eb
, u64 start
, int wait
,
4615 get_extent_t
*get_extent
, int mirror_num
)
4618 unsigned long start_i
;
4622 int locked_pages
= 0;
4623 int all_uptodate
= 1;
4624 unsigned long num_pages
;
4625 unsigned long num_reads
= 0;
4626 struct bio
*bio
= NULL
;
4627 unsigned long bio_flags
= 0;
4629 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
4633 WARN_ON(start
< eb
->start
);
4634 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
4635 (eb
->start
>> PAGE_CACHE_SHIFT
);
4640 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4641 for (i
= start_i
; i
< num_pages
; i
++) {
4642 page
= extent_buffer_page(eb
, i
);
4643 if (wait
== WAIT_NONE
) {
4644 if (!trylock_page(page
))
4650 if (!PageUptodate(page
)) {
4657 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4661 clear_bit(EXTENT_BUFFER_IOERR
, &eb
->bflags
);
4662 eb
->read_mirror
= 0;
4663 atomic_set(&eb
->io_pages
, num_reads
);
4664 for (i
= start_i
; i
< num_pages
; i
++) {
4665 page
= extent_buffer_page(eb
, i
);
4666 if (!PageUptodate(page
)) {
4667 ClearPageError(page
);
4668 err
= __extent_read_full_page(tree
, page
,
4670 mirror_num
, &bio_flags
,
4680 err
= submit_one_bio(READ
| REQ_META
, bio
, mirror_num
,
4686 if (ret
|| wait
!= WAIT_COMPLETE
)
4689 for (i
= start_i
; i
< num_pages
; i
++) {
4690 page
= extent_buffer_page(eb
, i
);
4691 wait_on_page_locked(page
);
4692 if (!PageUptodate(page
))
4700 while (locked_pages
> 0) {
4701 page
= extent_buffer_page(eb
, i
);
4709 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
4710 unsigned long start
,
4717 char *dst
= (char *)dstv
;
4718 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4719 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4721 WARN_ON(start
> eb
->len
);
4722 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4724 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4727 page
= extent_buffer_page(eb
, i
);
4729 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4730 kaddr
= page_address(page
);
4731 memcpy(dst
, kaddr
+ offset
, cur
);
4740 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
4741 unsigned long min_len
, char **map
,
4742 unsigned long *map_start
,
4743 unsigned long *map_len
)
4745 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
4748 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4749 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4750 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
4757 offset
= start_offset
;
4761 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
4764 if (start
+ min_len
> eb
->len
) {
4765 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
4766 "wanted %lu %lu\n", (unsigned long long)eb
->start
,
4767 eb
->len
, start
, min_len
);
4771 p
= extent_buffer_page(eb
, i
);
4772 kaddr
= page_address(p
);
4773 *map
= kaddr
+ offset
;
4774 *map_len
= PAGE_CACHE_SIZE
- offset
;
4778 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
4779 unsigned long start
,
4786 char *ptr
= (char *)ptrv
;
4787 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4788 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4791 WARN_ON(start
> eb
->len
);
4792 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4794 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4797 page
= extent_buffer_page(eb
, i
);
4799 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4801 kaddr
= page_address(page
);
4802 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
4814 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
4815 unsigned long start
, unsigned long len
)
4821 char *src
= (char *)srcv
;
4822 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4823 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4825 WARN_ON(start
> eb
->len
);
4826 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4828 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4831 page
= extent_buffer_page(eb
, i
);
4832 WARN_ON(!PageUptodate(page
));
4834 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
4835 kaddr
= page_address(page
);
4836 memcpy(kaddr
+ offset
, src
, cur
);
4845 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
4846 unsigned long start
, unsigned long len
)
4852 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4853 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4855 WARN_ON(start
> eb
->len
);
4856 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4858 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4861 page
= extent_buffer_page(eb
, i
);
4862 WARN_ON(!PageUptodate(page
));
4864 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
4865 kaddr
= page_address(page
);
4866 memset(kaddr
+ offset
, c
, cur
);
4874 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
4875 unsigned long dst_offset
, unsigned long src_offset
,
4878 u64 dst_len
= dst
->len
;
4883 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4884 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
4886 WARN_ON(src
->len
!= dst_len
);
4888 offset
= (start_offset
+ dst_offset
) &
4889 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4892 page
= extent_buffer_page(dst
, i
);
4893 WARN_ON(!PageUptodate(page
));
4895 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
4897 kaddr
= page_address(page
);
4898 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
4907 static void move_pages(struct page
*dst_page
, struct page
*src_page
,
4908 unsigned long dst_off
, unsigned long src_off
,
4911 char *dst_kaddr
= page_address(dst_page
);
4912 if (dst_page
== src_page
) {
4913 memmove(dst_kaddr
+ dst_off
, dst_kaddr
+ src_off
, len
);
4915 char *src_kaddr
= page_address(src_page
);
4916 char *p
= dst_kaddr
+ dst_off
+ len
;
4917 char *s
= src_kaddr
+ src_off
+ len
;
4924 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
4926 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
4927 return distance
< len
;
4930 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
4931 unsigned long dst_off
, unsigned long src_off
,
4934 char *dst_kaddr
= page_address(dst_page
);
4936 int must_memmove
= 0;
4938 if (dst_page
!= src_page
) {
4939 src_kaddr
= page_address(src_page
);
4941 src_kaddr
= dst_kaddr
;
4942 if (areas_overlap(src_off
, dst_off
, len
))
4947 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
4949 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
4952 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
4953 unsigned long src_offset
, unsigned long len
)
4956 size_t dst_off_in_page
;
4957 size_t src_off_in_page
;
4958 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4959 unsigned long dst_i
;
4960 unsigned long src_i
;
4962 if (src_offset
+ len
> dst
->len
) {
4963 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
4964 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
4967 if (dst_offset
+ len
> dst
->len
) {
4968 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
4969 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
4974 dst_off_in_page
= (start_offset
+ dst_offset
) &
4975 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4976 src_off_in_page
= (start_offset
+ src_offset
) &
4977 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4979 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
4980 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
4982 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
4984 cur
= min_t(unsigned long, cur
,
4985 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
4987 copy_pages(extent_buffer_page(dst
, dst_i
),
4988 extent_buffer_page(dst
, src_i
),
4989 dst_off_in_page
, src_off_in_page
, cur
);
4997 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
4998 unsigned long src_offset
, unsigned long len
)
5001 size_t dst_off_in_page
;
5002 size_t src_off_in_page
;
5003 unsigned long dst_end
= dst_offset
+ len
- 1;
5004 unsigned long src_end
= src_offset
+ len
- 1;
5005 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5006 unsigned long dst_i
;
5007 unsigned long src_i
;
5009 if (src_offset
+ len
> dst
->len
) {
5010 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
5011 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
5014 if (dst_offset
+ len
> dst
->len
) {
5015 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
5016 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
5019 if (dst_offset
< src_offset
) {
5020 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5024 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
5025 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
5027 dst_off_in_page
= (start_offset
+ dst_end
) &
5028 ((unsigned long)PAGE_CACHE_SIZE
- 1);
5029 src_off_in_page
= (start_offset
+ src_end
) &
5030 ((unsigned long)PAGE_CACHE_SIZE
- 1);
5032 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5033 cur
= min(cur
, dst_off_in_page
+ 1);
5034 move_pages(extent_buffer_page(dst
, dst_i
),
5035 extent_buffer_page(dst
, src_i
),
5036 dst_off_in_page
- cur
+ 1,
5037 src_off_in_page
- cur
+ 1, cur
);
5045 int try_release_extent_buffer(struct page
*page
)
5047 struct extent_buffer
*eb
;
5050 * We need to make sure noboody is attaching this page to an eb right
5053 spin_lock(&page
->mapping
->private_lock
);
5054 if (!PagePrivate(page
)) {
5055 spin_unlock(&page
->mapping
->private_lock
);
5059 eb
= (struct extent_buffer
*)page
->private;
5063 * This is a little awful but should be ok, we need to make sure that
5064 * the eb doesn't disappear out from under us while we're looking at
5067 spin_lock(&eb
->refs_lock
);
5068 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
5069 spin_unlock(&eb
->refs_lock
);
5070 spin_unlock(&page
->mapping
->private_lock
);
5073 spin_unlock(&page
->mapping
->private_lock
);
5076 * If tree ref isn't set then we know the ref on this eb is a real ref,
5077 * so just return, this page will likely be freed soon anyway.
5079 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
5080 spin_unlock(&eb
->refs_lock
);
5084 return release_extent_buffer(eb
);