1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/module.h>
8 #include <linux/spinlock.h>
9 #include <linux/blkdev.h>
10 #include <linux/swap.h>
11 #include <linux/writeback.h>
12 #include <linux/pagevec.h>
13 #include <linux/prefetch.h>
14 #include <linux/cleancache.h>
15 #include "extent_io.h"
16 #include "extent_map.h"
19 #include "btrfs_inode.h"
22 static struct kmem_cache
*extent_state_cache
;
23 static struct kmem_cache
*extent_buffer_cache
;
25 static LIST_HEAD(buffers
);
26 static LIST_HEAD(states
);
30 static DEFINE_SPINLOCK(leak_lock
);
33 #define BUFFER_LRU_MAX 64
38 struct rb_node rb_node
;
41 struct extent_page_data
{
43 struct extent_io_tree
*tree
;
44 get_extent_t
*get_extent
;
46 /* tells writepage not to lock the state bits for this range
47 * it still does the unlocking
49 unsigned int extent_locked
:1;
51 /* tells the submit_bio code to use a WRITE_SYNC */
52 unsigned int sync_io
:1;
55 int __init
extent_io_init(void)
57 extent_state_cache
= kmem_cache_create("extent_state",
58 sizeof(struct extent_state
), 0,
59 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
60 if (!extent_state_cache
)
63 extent_buffer_cache
= kmem_cache_create("extent_buffers",
64 sizeof(struct extent_buffer
), 0,
65 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
66 if (!extent_buffer_cache
)
67 goto free_state_cache
;
71 kmem_cache_destroy(extent_state_cache
);
75 void extent_io_exit(void)
77 struct extent_state
*state
;
78 struct extent_buffer
*eb
;
80 while (!list_empty(&states
)) {
81 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
82 printk(KERN_ERR
"btrfs state leak: start %llu end %llu "
83 "state %lu in tree %p refs %d\n",
84 (unsigned long long)state
->start
,
85 (unsigned long long)state
->end
,
86 state
->state
, state
->tree
, atomic_read(&state
->refs
));
87 list_del(&state
->leak_list
);
88 kmem_cache_free(extent_state_cache
, state
);
92 while (!list_empty(&buffers
)) {
93 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
94 printk(KERN_ERR
"btrfs buffer leak start %llu len %lu "
95 "refs %d\n", (unsigned long long)eb
->start
,
96 eb
->len
, atomic_read(&eb
->refs
));
97 list_del(&eb
->leak_list
);
98 kmem_cache_free(extent_buffer_cache
, eb
);
100 if (extent_state_cache
)
101 kmem_cache_destroy(extent_state_cache
);
102 if (extent_buffer_cache
)
103 kmem_cache_destroy(extent_buffer_cache
);
106 void extent_io_tree_init(struct extent_io_tree
*tree
,
107 struct address_space
*mapping
)
109 tree
->state
= RB_ROOT
;
110 INIT_RADIX_TREE(&tree
->buffer
, GFP_ATOMIC
);
112 tree
->dirty_bytes
= 0;
113 spin_lock_init(&tree
->lock
);
114 spin_lock_init(&tree
->buffer_lock
);
115 tree
->mapping
= mapping
;
118 static struct extent_state
*alloc_extent_state(gfp_t mask
)
120 struct extent_state
*state
;
125 state
= kmem_cache_alloc(extent_state_cache
, mask
);
132 spin_lock_irqsave(&leak_lock
, flags
);
133 list_add(&state
->leak_list
, &states
);
134 spin_unlock_irqrestore(&leak_lock
, flags
);
136 atomic_set(&state
->refs
, 1);
137 init_waitqueue_head(&state
->wq
);
141 void free_extent_state(struct extent_state
*state
)
145 if (atomic_dec_and_test(&state
->refs
)) {
149 WARN_ON(state
->tree
);
151 spin_lock_irqsave(&leak_lock
, flags
);
152 list_del(&state
->leak_list
);
153 spin_unlock_irqrestore(&leak_lock
, flags
);
155 kmem_cache_free(extent_state_cache
, state
);
159 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 offset
,
160 struct rb_node
*node
)
162 struct rb_node
**p
= &root
->rb_node
;
163 struct rb_node
*parent
= NULL
;
164 struct tree_entry
*entry
;
168 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
170 if (offset
< entry
->start
)
172 else if (offset
> entry
->end
)
178 entry
= rb_entry(node
, struct tree_entry
, rb_node
);
179 rb_link_node(node
, parent
, p
);
180 rb_insert_color(node
, root
);
184 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
185 struct rb_node
**prev_ret
,
186 struct rb_node
**next_ret
)
188 struct rb_root
*root
= &tree
->state
;
189 struct rb_node
*n
= root
->rb_node
;
190 struct rb_node
*prev
= NULL
;
191 struct rb_node
*orig_prev
= NULL
;
192 struct tree_entry
*entry
;
193 struct tree_entry
*prev_entry
= NULL
;
196 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
200 if (offset
< entry
->start
)
202 else if (offset
> entry
->end
)
210 while (prev
&& offset
> prev_entry
->end
) {
211 prev
= rb_next(prev
);
212 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
219 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
220 while (prev
&& offset
< prev_entry
->start
) {
221 prev
= rb_prev(prev
);
222 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
229 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
232 struct rb_node
*prev
= NULL
;
235 ret
= __etree_search(tree
, offset
, &prev
, NULL
);
241 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
242 struct extent_state
*other
)
244 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
245 tree
->ops
->merge_extent_hook(tree
->mapping
->host
, new,
250 * utility function to look for merge candidates inside a given range.
251 * Any extents with matching state are merged together into a single
252 * extent in the tree. Extents with EXTENT_IO in their state field
253 * are not merged because the end_io handlers need to be able to do
254 * operations on them without sleeping (or doing allocations/splits).
256 * This should be called with the tree lock held.
258 static void merge_state(struct extent_io_tree
*tree
,
259 struct extent_state
*state
)
261 struct extent_state
*other
;
262 struct rb_node
*other_node
;
264 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
267 other_node
= rb_prev(&state
->rb_node
);
269 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
270 if (other
->end
== state
->start
- 1 &&
271 other
->state
== state
->state
) {
272 merge_cb(tree
, state
, other
);
273 state
->start
= other
->start
;
275 rb_erase(&other
->rb_node
, &tree
->state
);
276 free_extent_state(other
);
279 other_node
= rb_next(&state
->rb_node
);
281 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
282 if (other
->start
== state
->end
+ 1 &&
283 other
->state
== state
->state
) {
284 merge_cb(tree
, state
, other
);
285 state
->end
= other
->end
;
287 rb_erase(&other
->rb_node
, &tree
->state
);
288 free_extent_state(other
);
293 static void set_state_cb(struct extent_io_tree
*tree
,
294 struct extent_state
*state
, int *bits
)
296 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
297 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
, bits
);
300 static void clear_state_cb(struct extent_io_tree
*tree
,
301 struct extent_state
*state
, int *bits
)
303 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
304 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
, bits
);
307 static void set_state_bits(struct extent_io_tree
*tree
,
308 struct extent_state
*state
, int *bits
);
311 * insert an extent_state struct into the tree. 'bits' are set on the
312 * struct before it is inserted.
314 * This may return -EEXIST if the extent is already there, in which case the
315 * state struct is freed.
317 * The tree lock is not taken internally. This is a utility function and
318 * probably isn't what you want to call (see set/clear_extent_bit).
320 static int insert_state(struct extent_io_tree
*tree
,
321 struct extent_state
*state
, u64 start
, u64 end
,
324 struct rb_node
*node
;
327 printk(KERN_ERR
"btrfs end < start %llu %llu\n",
328 (unsigned long long)end
,
329 (unsigned long long)start
);
332 state
->start
= start
;
335 set_state_bits(tree
, state
, bits
);
337 node
= tree_insert(&tree
->state
, end
, &state
->rb_node
);
339 struct extent_state
*found
;
340 found
= rb_entry(node
, struct extent_state
, rb_node
);
341 printk(KERN_ERR
"btrfs found node %llu %llu on insert of "
342 "%llu %llu\n", (unsigned long long)found
->start
,
343 (unsigned long long)found
->end
,
344 (unsigned long long)start
, (unsigned long long)end
);
348 merge_state(tree
, state
);
352 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
355 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
356 tree
->ops
->split_extent_hook(tree
->mapping
->host
, orig
, split
);
360 * split a given extent state struct in two, inserting the preallocated
361 * struct 'prealloc' as the newly created second half. 'split' indicates an
362 * offset inside 'orig' where it should be split.
365 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
366 * are two extent state structs in the tree:
367 * prealloc: [orig->start, split - 1]
368 * orig: [ split, orig->end ]
370 * The tree locks are not taken by this function. They need to be held
373 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
374 struct extent_state
*prealloc
, u64 split
)
376 struct rb_node
*node
;
378 split_cb(tree
, orig
, split
);
380 prealloc
->start
= orig
->start
;
381 prealloc
->end
= split
- 1;
382 prealloc
->state
= orig
->state
;
385 node
= tree_insert(&tree
->state
, prealloc
->end
, &prealloc
->rb_node
);
387 free_extent_state(prealloc
);
390 prealloc
->tree
= tree
;
395 * utility function to clear some bits in an extent state struct.
396 * it will optionally wake up any one waiting on this state (wake == 1), or
397 * forcibly remove the state from the tree (delete == 1).
399 * If no bits are set on the state struct after clearing things, the
400 * struct is freed and removed from the tree
402 static int clear_state_bit(struct extent_io_tree
*tree
,
403 struct extent_state
*state
,
406 int bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
407 int ret
= state
->state
& bits_to_clear
;
409 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
410 u64 range
= state
->end
- state
->start
+ 1;
411 WARN_ON(range
> tree
->dirty_bytes
);
412 tree
->dirty_bytes
-= range
;
414 clear_state_cb(tree
, state
, bits
);
415 state
->state
&= ~bits_to_clear
;
418 if (state
->state
== 0) {
420 rb_erase(&state
->rb_node
, &tree
->state
);
422 free_extent_state(state
);
427 merge_state(tree
, state
);
432 static struct extent_state
*
433 alloc_extent_state_atomic(struct extent_state
*prealloc
)
436 prealloc
= alloc_extent_state(GFP_ATOMIC
);
442 * clear some bits on a range in the tree. This may require splitting
443 * or inserting elements in the tree, so the gfp mask is used to
444 * indicate which allocations or sleeping are allowed.
446 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
447 * the given range from the tree regardless of state (ie for truncate).
449 * the range [start, end] is inclusive.
451 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
452 * bits were already set, or zero if none of the bits were already set.
454 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
455 int bits
, int wake
, int delete,
456 struct extent_state
**cached_state
,
459 struct extent_state
*state
;
460 struct extent_state
*cached
;
461 struct extent_state
*prealloc
= NULL
;
462 struct rb_node
*next_node
;
463 struct rb_node
*node
;
470 bits
|= ~EXTENT_CTLBITS
;
471 bits
|= EXTENT_FIRST_DELALLOC
;
473 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
476 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
477 prealloc
= alloc_extent_state(mask
);
482 spin_lock(&tree
->lock
);
484 cached
= *cached_state
;
487 *cached_state
= NULL
;
491 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
492 cached
->end
> start
) {
494 atomic_dec(&cached
->refs
);
499 free_extent_state(cached
);
502 * this search will find the extents that end after
505 node
= tree_search(tree
, start
);
508 state
= rb_entry(node
, struct extent_state
, rb_node
);
510 if (state
->start
> end
)
512 WARN_ON(state
->end
< start
);
513 last_end
= state
->end
;
516 * | ---- desired range ---- |
518 * | ------------- state -------------- |
520 * We need to split the extent we found, and may flip
521 * bits on second half.
523 * If the extent we found extends past our range, we
524 * just split and search again. It'll get split again
525 * the next time though.
527 * If the extent we found is inside our range, we clear
528 * the desired bit on it.
531 if (state
->start
< start
) {
532 prealloc
= alloc_extent_state_atomic(prealloc
);
534 err
= split_state(tree
, state
, prealloc
, start
);
535 BUG_ON(err
== -EEXIST
);
539 if (state
->end
<= end
) {
540 set
|= clear_state_bit(tree
, state
, &bits
, wake
);
541 if (last_end
== (u64
)-1)
543 start
= last_end
+ 1;
548 * | ---- desired range ---- |
550 * We need to split the extent, and clear the bit
553 if (state
->start
<= end
&& state
->end
> end
) {
554 prealloc
= alloc_extent_state_atomic(prealloc
);
556 err
= split_state(tree
, state
, prealloc
, end
+ 1);
557 BUG_ON(err
== -EEXIST
);
561 set
|= clear_state_bit(tree
, prealloc
, &bits
, wake
);
567 if (state
->end
< end
&& prealloc
&& !need_resched())
568 next_node
= rb_next(&state
->rb_node
);
572 set
|= clear_state_bit(tree
, state
, &bits
, wake
);
573 if (last_end
== (u64
)-1)
575 start
= last_end
+ 1;
576 if (start
<= end
&& next_node
) {
577 state
= rb_entry(next_node
, struct extent_state
,
579 if (state
->start
== start
)
585 spin_unlock(&tree
->lock
);
587 free_extent_state(prealloc
);
594 spin_unlock(&tree
->lock
);
595 if (mask
& __GFP_WAIT
)
600 static int wait_on_state(struct extent_io_tree
*tree
,
601 struct extent_state
*state
)
602 __releases(tree
->lock
)
603 __acquires(tree
->lock
)
606 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
607 spin_unlock(&tree
->lock
);
609 spin_lock(&tree
->lock
);
610 finish_wait(&state
->wq
, &wait
);
615 * waits for one or more bits to clear on a range in the state tree.
616 * The range [start, end] is inclusive.
617 * The tree lock is taken by this function
619 int wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
, int bits
)
621 struct extent_state
*state
;
622 struct rb_node
*node
;
624 spin_lock(&tree
->lock
);
628 * this search will find all the extents that end after
631 node
= tree_search(tree
, start
);
635 state
= rb_entry(node
, struct extent_state
, rb_node
);
637 if (state
->start
> end
)
640 if (state
->state
& bits
) {
641 start
= state
->start
;
642 atomic_inc(&state
->refs
);
643 wait_on_state(tree
, state
);
644 free_extent_state(state
);
647 start
= state
->end
+ 1;
652 cond_resched_lock(&tree
->lock
);
655 spin_unlock(&tree
->lock
);
659 static void set_state_bits(struct extent_io_tree
*tree
,
660 struct extent_state
*state
,
663 int bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
665 set_state_cb(tree
, state
, bits
);
666 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
667 u64 range
= state
->end
- state
->start
+ 1;
668 tree
->dirty_bytes
+= range
;
670 state
->state
|= bits_to_set
;
673 static void cache_state(struct extent_state
*state
,
674 struct extent_state
**cached_ptr
)
676 if (cached_ptr
&& !(*cached_ptr
)) {
677 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
)) {
679 atomic_inc(&state
->refs
);
684 static void uncache_state(struct extent_state
**cached_ptr
)
686 if (cached_ptr
&& (*cached_ptr
)) {
687 struct extent_state
*state
= *cached_ptr
;
689 free_extent_state(state
);
694 * set some bits on a range in the tree. This may require allocations or
695 * sleeping, so the gfp mask is used to indicate what is allowed.
697 * If any of the exclusive bits are set, this will fail with -EEXIST if some
698 * part of the range already has the desired bits set. The start of the
699 * existing range is returned in failed_start in this case.
701 * [start, end] is inclusive This takes the tree lock.
704 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
705 int bits
, int exclusive_bits
, u64
*failed_start
,
706 struct extent_state
**cached_state
, gfp_t mask
)
708 struct extent_state
*state
;
709 struct extent_state
*prealloc
= NULL
;
710 struct rb_node
*node
;
715 bits
|= EXTENT_FIRST_DELALLOC
;
717 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
718 prealloc
= alloc_extent_state(mask
);
722 spin_lock(&tree
->lock
);
723 if (cached_state
&& *cached_state
) {
724 state
= *cached_state
;
725 if (state
->start
<= start
&& state
->end
> start
&&
727 node
= &state
->rb_node
;
732 * this search will find all the extents that end after
735 node
= tree_search(tree
, start
);
737 prealloc
= alloc_extent_state_atomic(prealloc
);
739 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
741 BUG_ON(err
== -EEXIST
);
744 state
= rb_entry(node
, struct extent_state
, rb_node
);
746 last_start
= state
->start
;
747 last_end
= state
->end
;
750 * | ---- desired range ---- |
753 * Just lock what we found and keep going
755 if (state
->start
== start
&& state
->end
<= end
) {
756 struct rb_node
*next_node
;
757 if (state
->state
& exclusive_bits
) {
758 *failed_start
= state
->start
;
763 set_state_bits(tree
, state
, &bits
);
765 cache_state(state
, cached_state
);
766 merge_state(tree
, state
);
767 if (last_end
== (u64
)-1)
770 start
= last_end
+ 1;
771 next_node
= rb_next(&state
->rb_node
);
772 if (next_node
&& start
< end
&& prealloc
&& !need_resched()) {
773 state
= rb_entry(next_node
, struct extent_state
,
775 if (state
->start
== start
)
782 * | ---- desired range ---- |
785 * | ------------- state -------------- |
787 * We need to split the extent we found, and may flip bits on
790 * If the extent we found extends past our
791 * range, we just split and search again. It'll get split
792 * again the next time though.
794 * If the extent we found is inside our range, we set the
797 if (state
->start
< start
) {
798 if (state
->state
& exclusive_bits
) {
799 *failed_start
= start
;
804 prealloc
= alloc_extent_state_atomic(prealloc
);
806 err
= split_state(tree
, state
, prealloc
, start
);
807 BUG_ON(err
== -EEXIST
);
811 if (state
->end
<= end
) {
812 set_state_bits(tree
, state
, &bits
);
813 cache_state(state
, cached_state
);
814 merge_state(tree
, state
);
815 if (last_end
== (u64
)-1)
817 start
= last_end
+ 1;
822 * | ---- desired range ---- |
823 * | state | or | state |
825 * There's a hole, we need to insert something in it and
826 * ignore the extent we found.
828 if (state
->start
> start
) {
830 if (end
< last_start
)
833 this_end
= last_start
- 1;
835 prealloc
= alloc_extent_state_atomic(prealloc
);
839 * Avoid to free 'prealloc' if it can be merged with
842 err
= insert_state(tree
, prealloc
, start
, this_end
,
844 BUG_ON(err
== -EEXIST
);
846 free_extent_state(prealloc
);
850 cache_state(prealloc
, cached_state
);
852 start
= this_end
+ 1;
856 * | ---- desired range ---- |
858 * We need to split the extent, and set the bit
861 if (state
->start
<= end
&& state
->end
> end
) {
862 if (state
->state
& exclusive_bits
) {
863 *failed_start
= start
;
868 prealloc
= alloc_extent_state_atomic(prealloc
);
870 err
= split_state(tree
, state
, prealloc
, end
+ 1);
871 BUG_ON(err
== -EEXIST
);
873 set_state_bits(tree
, prealloc
, &bits
);
874 cache_state(prealloc
, cached_state
);
875 merge_state(tree
, prealloc
);
883 spin_unlock(&tree
->lock
);
885 free_extent_state(prealloc
);
892 spin_unlock(&tree
->lock
);
893 if (mask
& __GFP_WAIT
)
899 * convert_extent - convert all bits in a given range from one bit to another
900 * @tree: the io tree to search
901 * @start: the start offset in bytes
902 * @end: the end offset in bytes (inclusive)
903 * @bits: the bits to set in this range
904 * @clear_bits: the bits to clear in this range
905 * @mask: the allocation mask
907 * This will go through and set bits for the given range. If any states exist
908 * already in this range they are set with the given bit and cleared of the
909 * clear_bits. This is only meant to be used by things that are mergeable, ie
910 * converting from say DELALLOC to DIRTY. This is not meant to be used with
911 * boundary bits like LOCK.
913 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
914 int bits
, int clear_bits
, gfp_t mask
)
916 struct extent_state
*state
;
917 struct extent_state
*prealloc
= NULL
;
918 struct rb_node
*node
;
924 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
925 prealloc
= alloc_extent_state(mask
);
930 spin_lock(&tree
->lock
);
932 * this search will find all the extents that end after
935 node
= tree_search(tree
, start
);
937 prealloc
= alloc_extent_state_atomic(prealloc
);
940 err
= insert_state(tree
, prealloc
, start
, end
, &bits
);
942 BUG_ON(err
== -EEXIST
);
945 state
= rb_entry(node
, struct extent_state
, rb_node
);
947 last_start
= state
->start
;
948 last_end
= state
->end
;
951 * | ---- desired range ---- |
954 * Just lock what we found and keep going
956 if (state
->start
== start
&& state
->end
<= end
) {
957 struct rb_node
*next_node
;
959 set_state_bits(tree
, state
, &bits
);
960 clear_state_bit(tree
, state
, &clear_bits
, 0);
962 merge_state(tree
, state
);
963 if (last_end
== (u64
)-1)
966 start
= last_end
+ 1;
967 next_node
= rb_next(&state
->rb_node
);
968 if (next_node
&& start
< end
&& prealloc
&& !need_resched()) {
969 state
= rb_entry(next_node
, struct extent_state
,
971 if (state
->start
== start
)
978 * | ---- desired range ---- |
981 * | ------------- state -------------- |
983 * We need to split the extent we found, and may flip bits on
986 * If the extent we found extends past our
987 * range, we just split and search again. It'll get split
988 * again the next time though.
990 * If the extent we found is inside our range, we set the
993 if (state
->start
< start
) {
994 prealloc
= alloc_extent_state_atomic(prealloc
);
997 err
= split_state(tree
, state
, prealloc
, start
);
998 BUG_ON(err
== -EEXIST
);
1002 if (state
->end
<= end
) {
1003 set_state_bits(tree
, state
, &bits
);
1004 clear_state_bit(tree
, state
, &clear_bits
, 0);
1005 merge_state(tree
, state
);
1006 if (last_end
== (u64
)-1)
1008 start
= last_end
+ 1;
1013 * | ---- desired range ---- |
1014 * | state | or | state |
1016 * There's a hole, we need to insert something in it and
1017 * ignore the extent we found.
1019 if (state
->start
> start
) {
1021 if (end
< last_start
)
1024 this_end
= last_start
- 1;
1026 prealloc
= alloc_extent_state_atomic(prealloc
);
1031 * Avoid to free 'prealloc' if it can be merged with
1034 err
= insert_state(tree
, prealloc
, start
, this_end
,
1036 BUG_ON(err
== -EEXIST
);
1038 free_extent_state(prealloc
);
1043 start
= this_end
+ 1;
1047 * | ---- desired range ---- |
1049 * We need to split the extent, and set the bit
1052 if (state
->start
<= end
&& state
->end
> end
) {
1053 prealloc
= alloc_extent_state_atomic(prealloc
);
1057 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1058 BUG_ON(err
== -EEXIST
);
1060 set_state_bits(tree
, prealloc
, &bits
);
1061 clear_state_bit(tree
, prealloc
, &clear_bits
, 0);
1063 merge_state(tree
, prealloc
);
1071 spin_unlock(&tree
->lock
);
1073 free_extent_state(prealloc
);
1080 spin_unlock(&tree
->lock
);
1081 if (mask
& __GFP_WAIT
)
1086 /* wrappers around set/clear extent bit */
1087 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1090 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, 0, NULL
,
1094 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1095 int bits
, gfp_t mask
)
1097 return set_extent_bit(tree
, start
, end
, bits
, 0, NULL
,
1101 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1102 int bits
, gfp_t mask
)
1104 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, mask
);
1107 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1108 struct extent_state
**cached_state
, gfp_t mask
)
1110 return set_extent_bit(tree
, start
, end
,
1111 EXTENT_DELALLOC
| EXTENT_UPTODATE
,
1112 0, NULL
, cached_state
, mask
);
1115 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1118 return clear_extent_bit(tree
, start
, end
,
1119 EXTENT_DIRTY
| EXTENT_DELALLOC
|
1120 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
, mask
);
1123 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1126 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, 0, NULL
,
1130 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1131 struct extent_state
**cached_state
, gfp_t mask
)
1133 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0,
1134 NULL
, cached_state
, mask
);
1137 static int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
,
1138 u64 end
, struct extent_state
**cached_state
,
1141 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0,
1142 cached_state
, mask
);
1146 * either insert or lock state struct between start and end use mask to tell
1147 * us if waiting is desired.
1149 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1150 int bits
, struct extent_state
**cached_state
, gfp_t mask
)
1155 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
1156 EXTENT_LOCKED
, &failed_start
,
1157 cached_state
, mask
);
1158 if (err
== -EEXIST
&& (mask
& __GFP_WAIT
)) {
1159 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1160 start
= failed_start
;
1164 WARN_ON(start
> end
);
1169 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
, gfp_t mask
)
1171 return lock_extent_bits(tree
, start
, end
, 0, NULL
, mask
);
1174 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1180 err
= set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1181 &failed_start
, NULL
, mask
);
1182 if (err
== -EEXIST
) {
1183 if (failed_start
> start
)
1184 clear_extent_bit(tree
, start
, failed_start
- 1,
1185 EXTENT_LOCKED
, 1, 0, NULL
, mask
);
1191 int unlock_extent_cached(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1192 struct extent_state
**cached
, gfp_t mask
)
1194 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, cached
,
1198 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
, gfp_t mask
)
1200 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, NULL
,
1205 * helper function to set both pages and extents in the tree writeback
1207 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1209 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1210 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1213 while (index
<= end_index
) {
1214 page
= find_get_page(tree
->mapping
, index
);
1216 set_page_writeback(page
);
1217 page_cache_release(page
);
1223 /* find the first state struct with 'bits' set after 'start', and
1224 * return it. tree->lock must be held. NULL will returned if
1225 * nothing was found after 'start'
1227 struct extent_state
*find_first_extent_bit_state(struct extent_io_tree
*tree
,
1228 u64 start
, int bits
)
1230 struct rb_node
*node
;
1231 struct extent_state
*state
;
1234 * this search will find all the extents that end after
1237 node
= tree_search(tree
, start
);
1242 state
= rb_entry(node
, struct extent_state
, rb_node
);
1243 if (state
->end
>= start
&& (state
->state
& bits
))
1246 node
= rb_next(node
);
1255 * find the first offset in the io tree with 'bits' set. zero is
1256 * returned if we find something, and *start_ret and *end_ret are
1257 * set to reflect the state struct that was found.
1259 * If nothing was found, 1 is returned, < 0 on error
1261 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1262 u64
*start_ret
, u64
*end_ret
, int bits
)
1264 struct extent_state
*state
;
1267 spin_lock(&tree
->lock
);
1268 state
= find_first_extent_bit_state(tree
, start
, bits
);
1270 *start_ret
= state
->start
;
1271 *end_ret
= state
->end
;
1274 spin_unlock(&tree
->lock
);
1279 * find a contiguous range of bytes in the file marked as delalloc, not
1280 * more than 'max_bytes'. start and end are used to return the range,
1282 * 1 is returned if we find something, 0 if nothing was in the tree
1284 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1285 u64
*start
, u64
*end
, u64 max_bytes
,
1286 struct extent_state
**cached_state
)
1288 struct rb_node
*node
;
1289 struct extent_state
*state
;
1290 u64 cur_start
= *start
;
1292 u64 total_bytes
= 0;
1294 spin_lock(&tree
->lock
);
1297 * this search will find all the extents that end after
1300 node
= tree_search(tree
, cur_start
);
1308 state
= rb_entry(node
, struct extent_state
, rb_node
);
1309 if (found
&& (state
->start
!= cur_start
||
1310 (state
->state
& EXTENT_BOUNDARY
))) {
1313 if (!(state
->state
& EXTENT_DELALLOC
)) {
1319 *start
= state
->start
;
1320 *cached_state
= state
;
1321 atomic_inc(&state
->refs
);
1325 cur_start
= state
->end
+ 1;
1326 node
= rb_next(node
);
1329 total_bytes
+= state
->end
- state
->start
+ 1;
1330 if (total_bytes
>= max_bytes
)
1334 spin_unlock(&tree
->lock
);
1338 static noinline
int __unlock_for_delalloc(struct inode
*inode
,
1339 struct page
*locked_page
,
1343 struct page
*pages
[16];
1344 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1345 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1346 unsigned long nr_pages
= end_index
- index
+ 1;
1349 if (index
== locked_page
->index
&& end_index
== index
)
1352 while (nr_pages
> 0) {
1353 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1354 min_t(unsigned long, nr_pages
,
1355 ARRAY_SIZE(pages
)), pages
);
1356 for (i
= 0; i
< ret
; i
++) {
1357 if (pages
[i
] != locked_page
)
1358 unlock_page(pages
[i
]);
1359 page_cache_release(pages
[i
]);
1368 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1369 struct page
*locked_page
,
1373 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1374 unsigned long start_index
= index
;
1375 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1376 unsigned long pages_locked
= 0;
1377 struct page
*pages
[16];
1378 unsigned long nrpages
;
1382 /* the caller is responsible for locking the start index */
1383 if (index
== locked_page
->index
&& index
== end_index
)
1386 /* skip the page at the start index */
1387 nrpages
= end_index
- index
+ 1;
1388 while (nrpages
> 0) {
1389 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1390 min_t(unsigned long,
1391 nrpages
, ARRAY_SIZE(pages
)), pages
);
1396 /* now we have an array of pages, lock them all */
1397 for (i
= 0; i
< ret
; i
++) {
1399 * the caller is taking responsibility for
1402 if (pages
[i
] != locked_page
) {
1403 lock_page(pages
[i
]);
1404 if (!PageDirty(pages
[i
]) ||
1405 pages
[i
]->mapping
!= inode
->i_mapping
) {
1407 unlock_page(pages
[i
]);
1408 page_cache_release(pages
[i
]);
1412 page_cache_release(pages
[i
]);
1421 if (ret
&& pages_locked
) {
1422 __unlock_for_delalloc(inode
, locked_page
,
1424 ((u64
)(start_index
+ pages_locked
- 1)) <<
1431 * find a contiguous range of bytes in the file marked as delalloc, not
1432 * more than 'max_bytes'. start and end are used to return the range,
1434 * 1 is returned if we find something, 0 if nothing was in the tree
1436 static noinline u64
find_lock_delalloc_range(struct inode
*inode
,
1437 struct extent_io_tree
*tree
,
1438 struct page
*locked_page
,
1439 u64
*start
, u64
*end
,
1445 struct extent_state
*cached_state
= NULL
;
1450 /* step one, find a bunch of delalloc bytes starting at start */
1451 delalloc_start
= *start
;
1453 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1454 max_bytes
, &cached_state
);
1455 if (!found
|| delalloc_end
<= *start
) {
1456 *start
= delalloc_start
;
1457 *end
= delalloc_end
;
1458 free_extent_state(cached_state
);
1463 * start comes from the offset of locked_page. We have to lock
1464 * pages in order, so we can't process delalloc bytes before
1467 if (delalloc_start
< *start
)
1468 delalloc_start
= *start
;
1471 * make sure to limit the number of pages we try to lock down
1474 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
&& loops
)
1475 delalloc_end
= delalloc_start
+ PAGE_CACHE_SIZE
- 1;
1477 /* step two, lock all the pages after the page that has start */
1478 ret
= lock_delalloc_pages(inode
, locked_page
,
1479 delalloc_start
, delalloc_end
);
1480 if (ret
== -EAGAIN
) {
1481 /* some of the pages are gone, lets avoid looping by
1482 * shortening the size of the delalloc range we're searching
1484 free_extent_state(cached_state
);
1486 unsigned long offset
= (*start
) & (PAGE_CACHE_SIZE
- 1);
1487 max_bytes
= PAGE_CACHE_SIZE
- offset
;
1497 /* step three, lock the state bits for the whole range */
1498 lock_extent_bits(tree
, delalloc_start
, delalloc_end
,
1499 0, &cached_state
, GFP_NOFS
);
1501 /* then test to make sure it is all still delalloc */
1502 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1503 EXTENT_DELALLOC
, 1, cached_state
);
1505 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1506 &cached_state
, GFP_NOFS
);
1507 __unlock_for_delalloc(inode
, locked_page
,
1508 delalloc_start
, delalloc_end
);
1512 free_extent_state(cached_state
);
1513 *start
= delalloc_start
;
1514 *end
= delalloc_end
;
1519 int extent_clear_unlock_delalloc(struct inode
*inode
,
1520 struct extent_io_tree
*tree
,
1521 u64 start
, u64 end
, struct page
*locked_page
,
1525 struct page
*pages
[16];
1526 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1527 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1528 unsigned long nr_pages
= end_index
- index
+ 1;
1532 if (op
& EXTENT_CLEAR_UNLOCK
)
1533 clear_bits
|= EXTENT_LOCKED
;
1534 if (op
& EXTENT_CLEAR_DIRTY
)
1535 clear_bits
|= EXTENT_DIRTY
;
1537 if (op
& EXTENT_CLEAR_DELALLOC
)
1538 clear_bits
|= EXTENT_DELALLOC
;
1540 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, NULL
, GFP_NOFS
);
1541 if (!(op
& (EXTENT_CLEAR_UNLOCK_PAGE
| EXTENT_CLEAR_DIRTY
|
1542 EXTENT_SET_WRITEBACK
| EXTENT_END_WRITEBACK
|
1543 EXTENT_SET_PRIVATE2
)))
1546 while (nr_pages
> 0) {
1547 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1548 min_t(unsigned long,
1549 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1550 for (i
= 0; i
< ret
; i
++) {
1552 if (op
& EXTENT_SET_PRIVATE2
)
1553 SetPagePrivate2(pages
[i
]);
1555 if (pages
[i
] == locked_page
) {
1556 page_cache_release(pages
[i
]);
1559 if (op
& EXTENT_CLEAR_DIRTY
)
1560 clear_page_dirty_for_io(pages
[i
]);
1561 if (op
& EXTENT_SET_WRITEBACK
)
1562 set_page_writeback(pages
[i
]);
1563 if (op
& EXTENT_END_WRITEBACK
)
1564 end_page_writeback(pages
[i
]);
1565 if (op
& EXTENT_CLEAR_UNLOCK_PAGE
)
1566 unlock_page(pages
[i
]);
1567 page_cache_release(pages
[i
]);
1577 * count the number of bytes in the tree that have a given bit(s)
1578 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1579 * cached. The total number found is returned.
1581 u64
count_range_bits(struct extent_io_tree
*tree
,
1582 u64
*start
, u64 search_end
, u64 max_bytes
,
1583 unsigned long bits
, int contig
)
1585 struct rb_node
*node
;
1586 struct extent_state
*state
;
1587 u64 cur_start
= *start
;
1588 u64 total_bytes
= 0;
1592 if (search_end
<= cur_start
) {
1597 spin_lock(&tree
->lock
);
1598 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1599 total_bytes
= tree
->dirty_bytes
;
1603 * this search will find all the extents that end after
1606 node
= tree_search(tree
, cur_start
);
1611 state
= rb_entry(node
, struct extent_state
, rb_node
);
1612 if (state
->start
> search_end
)
1614 if (contig
&& found
&& state
->start
> last
+ 1)
1616 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1617 total_bytes
+= min(search_end
, state
->end
) + 1 -
1618 max(cur_start
, state
->start
);
1619 if (total_bytes
>= max_bytes
)
1622 *start
= max(cur_start
, state
->start
);
1626 } else if (contig
&& found
) {
1629 node
= rb_next(node
);
1634 spin_unlock(&tree
->lock
);
1639 * set the private field for a given byte offset in the tree. If there isn't
1640 * an extent_state there already, this does nothing.
1642 int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1644 struct rb_node
*node
;
1645 struct extent_state
*state
;
1648 spin_lock(&tree
->lock
);
1650 * this search will find all the extents that end after
1653 node
= tree_search(tree
, start
);
1658 state
= rb_entry(node
, struct extent_state
, rb_node
);
1659 if (state
->start
!= start
) {
1663 state
->private = private;
1665 spin_unlock(&tree
->lock
);
1669 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1671 struct rb_node
*node
;
1672 struct extent_state
*state
;
1675 spin_lock(&tree
->lock
);
1677 * this search will find all the extents that end after
1680 node
= tree_search(tree
, start
);
1685 state
= rb_entry(node
, struct extent_state
, rb_node
);
1686 if (state
->start
!= start
) {
1690 *private = state
->private;
1692 spin_unlock(&tree
->lock
);
1697 * searches a range in the state tree for a given mask.
1698 * If 'filled' == 1, this returns 1 only if every extent in the tree
1699 * has the bits set. Otherwise, 1 is returned if any bit in the
1700 * range is found set.
1702 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1703 int bits
, int filled
, struct extent_state
*cached
)
1705 struct extent_state
*state
= NULL
;
1706 struct rb_node
*node
;
1709 spin_lock(&tree
->lock
);
1710 if (cached
&& cached
->tree
&& cached
->start
<= start
&&
1711 cached
->end
> start
)
1712 node
= &cached
->rb_node
;
1714 node
= tree_search(tree
, start
);
1715 while (node
&& start
<= end
) {
1716 state
= rb_entry(node
, struct extent_state
, rb_node
);
1718 if (filled
&& state
->start
> start
) {
1723 if (state
->start
> end
)
1726 if (state
->state
& bits
) {
1730 } else if (filled
) {
1735 if (state
->end
== (u64
)-1)
1738 start
= state
->end
+ 1;
1741 node
= rb_next(node
);
1748 spin_unlock(&tree
->lock
);
1753 * helper function to set a given page up to date if all the
1754 * extents in the tree for that page are up to date
1756 static int check_page_uptodate(struct extent_io_tree
*tree
,
1759 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1760 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1761 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1762 SetPageUptodate(page
);
1767 * helper function to unlock a page if all the extents in the tree
1768 * for that page are unlocked
1770 static int check_page_locked(struct extent_io_tree
*tree
,
1773 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
1774 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1775 if (!test_range_bit(tree
, start
, end
, EXTENT_LOCKED
, 0, NULL
))
1781 * helper function to end page writeback if all the extents
1782 * in the tree for that page are done with writeback
1784 static int check_page_writeback(struct extent_io_tree
*tree
,
1787 end_page_writeback(page
);
1792 * When IO fails, either with EIO or csum verification fails, we
1793 * try other mirrors that might have a good copy of the data. This
1794 * io_failure_record is used to record state as we go through all the
1795 * mirrors. If another mirror has good data, the page is set up to date
1796 * and things continue. If a good mirror can't be found, the original
1797 * bio end_io callback is called to indicate things have failed.
1799 struct io_failure_record
{
1804 unsigned long bio_flags
;
1810 static int free_io_failure(struct inode
*inode
, struct io_failure_record
*rec
,
1815 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
1817 set_state_private(failure_tree
, rec
->start
, 0);
1818 ret
= clear_extent_bits(failure_tree
, rec
->start
,
1819 rec
->start
+ rec
->len
- 1,
1820 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
1825 ret
= clear_extent_bits(&BTRFS_I(inode
)->io_tree
, rec
->start
,
1826 rec
->start
+ rec
->len
- 1,
1827 EXTENT_DAMAGED
, GFP_NOFS
);
1836 static void repair_io_failure_callback(struct bio
*bio
, int err
)
1838 complete(bio
->bi_private
);
1842 * this bypasses the standard btrfs submit functions deliberately, as
1843 * the standard behavior is to write all copies in a raid setup. here we only
1844 * want to write the one bad copy. so we do the mapping for ourselves and issue
1845 * submit_bio directly.
1846 * to avoid any synchonization issues, wait for the data after writing, which
1847 * actually prevents the read that triggered the error from finishing.
1848 * currently, there can be no more than two copies of every data bit. thus,
1849 * exactly one rewrite is required.
1851 int repair_io_failure(struct btrfs_mapping_tree
*map_tree
, u64 start
,
1852 u64 length
, u64 logical
, struct page
*page
,
1856 struct btrfs_device
*dev
;
1857 DECLARE_COMPLETION_ONSTACK(compl);
1860 struct btrfs_bio
*bbio
= NULL
;
1863 BUG_ON(!mirror_num
);
1865 bio
= bio_alloc(GFP_NOFS
, 1);
1868 bio
->bi_private
= &compl;
1869 bio
->bi_end_io
= repair_io_failure_callback
;
1871 map_length
= length
;
1873 ret
= btrfs_map_block(map_tree
, WRITE
, logical
,
1874 &map_length
, &bbio
, mirror_num
);
1879 BUG_ON(mirror_num
!= bbio
->mirror_num
);
1880 sector
= bbio
->stripes
[mirror_num
-1].physical
>> 9;
1881 bio
->bi_sector
= sector
;
1882 dev
= bbio
->stripes
[mirror_num
-1].dev
;
1884 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
1888 bio
->bi_bdev
= dev
->bdev
;
1889 bio_add_page(bio
, page
, length
, start
-page_offset(page
));
1890 submit_bio(WRITE_SYNC
, bio
);
1891 wait_for_completion(&compl);
1893 if (!test_bit(BIO_UPTODATE
, &bio
->bi_flags
)) {
1894 /* try to remap that extent elsewhere? */
1899 printk(KERN_INFO
"btrfs read error corrected: ino %lu off %llu (dev %s "
1900 "sector %llu)\n", page
->mapping
->host
->i_ino
, start
,
1908 * each time an IO finishes, we do a fast check in the IO failure tree
1909 * to see if we need to process or clean up an io_failure_record
1911 static int clean_io_failure(u64 start
, struct page
*page
)
1914 u64 private_failure
;
1915 struct io_failure_record
*failrec
;
1916 struct btrfs_mapping_tree
*map_tree
;
1917 struct extent_state
*state
;
1921 struct inode
*inode
= page
->mapping
->host
;
1924 ret
= count_range_bits(&BTRFS_I(inode
)->io_failure_tree
, &private,
1925 (u64
)-1, 1, EXTENT_DIRTY
, 0);
1929 ret
= get_state_private(&BTRFS_I(inode
)->io_failure_tree
, start
,
1934 failrec
= (struct io_failure_record
*)(unsigned long) private_failure
;
1935 BUG_ON(!failrec
->this_mirror
);
1937 if (failrec
->in_validation
) {
1938 /* there was no real error, just free the record */
1939 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
1945 spin_lock(&BTRFS_I(inode
)->io_tree
.lock
);
1946 state
= find_first_extent_bit_state(&BTRFS_I(inode
)->io_tree
,
1949 spin_unlock(&BTRFS_I(inode
)->io_tree
.lock
);
1951 if (state
&& state
->start
== failrec
->start
) {
1952 map_tree
= &BTRFS_I(inode
)->root
->fs_info
->mapping_tree
;
1953 num_copies
= btrfs_num_copies(map_tree
, failrec
->logical
,
1955 if (num_copies
> 1) {
1956 ret
= repair_io_failure(map_tree
, start
, failrec
->len
,
1957 failrec
->logical
, page
,
1958 failrec
->failed_mirror
);
1965 ret
= free_io_failure(inode
, failrec
, did_repair
);
1971 * this is a generic handler for readpage errors (default
1972 * readpage_io_failed_hook). if other copies exist, read those and write back
1973 * good data to the failed position. does not investigate in remapping the
1974 * failed extent elsewhere, hoping the device will be smart enough to do this as
1978 static int bio_readpage_error(struct bio
*failed_bio
, struct page
*page
,
1979 u64 start
, u64 end
, int failed_mirror
,
1980 struct extent_state
*state
)
1982 struct io_failure_record
*failrec
= NULL
;
1984 struct extent_map
*em
;
1985 struct inode
*inode
= page
->mapping
->host
;
1986 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
1987 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
1988 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
1995 BUG_ON(failed_bio
->bi_rw
& REQ_WRITE
);
1997 ret
= get_state_private(failure_tree
, start
, &private);
1999 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2002 failrec
->start
= start
;
2003 failrec
->len
= end
- start
+ 1;
2004 failrec
->this_mirror
= 0;
2005 failrec
->bio_flags
= 0;
2006 failrec
->in_validation
= 0;
2008 read_lock(&em_tree
->lock
);
2009 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2011 read_unlock(&em_tree
->lock
);
2016 if (em
->start
> start
|| em
->start
+ em
->len
< start
) {
2017 free_extent_map(em
);
2020 read_unlock(&em_tree
->lock
);
2022 if (!em
|| IS_ERR(em
)) {
2026 logical
= start
- em
->start
;
2027 logical
= em
->block_start
+ logical
;
2028 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2029 logical
= em
->block_start
;
2030 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2031 extent_set_compress_type(&failrec
->bio_flags
,
2034 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2035 "len=%llu\n", logical
, start
, failrec
->len
);
2036 failrec
->logical
= logical
;
2037 free_extent_map(em
);
2039 /* set the bits in the private failure tree */
2040 ret
= set_extent_bits(failure_tree
, start
, end
,
2041 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
2043 ret
= set_state_private(failure_tree
, start
,
2044 (u64
)(unsigned long)failrec
);
2045 /* set the bits in the inode's tree */
2047 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
,
2054 failrec
= (struct io_failure_record
*)(unsigned long)private;
2055 pr_debug("bio_readpage_error: (found) logical=%llu, "
2056 "start=%llu, len=%llu, validation=%d\n",
2057 failrec
->logical
, failrec
->start
, failrec
->len
,
2058 failrec
->in_validation
);
2060 * when data can be on disk more than twice, add to failrec here
2061 * (e.g. with a list for failed_mirror) to make
2062 * clean_io_failure() clean all those errors at once.
2065 num_copies
= btrfs_num_copies(
2066 &BTRFS_I(inode
)->root
->fs_info
->mapping_tree
,
2067 failrec
->logical
, failrec
->len
);
2068 if (num_copies
== 1) {
2070 * we only have a single copy of the data, so don't bother with
2071 * all the retry and error correction code that follows. no
2072 * matter what the error is, it is very likely to persist.
2074 pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
2075 "state=%p, num_copies=%d, next_mirror %d, "
2076 "failed_mirror %d\n", state
, num_copies
,
2077 failrec
->this_mirror
, failed_mirror
);
2078 free_io_failure(inode
, failrec
, 0);
2083 spin_lock(&tree
->lock
);
2084 state
= find_first_extent_bit_state(tree
, failrec
->start
,
2086 if (state
&& state
->start
!= failrec
->start
)
2088 spin_unlock(&tree
->lock
);
2092 * there are two premises:
2093 * a) deliver good data to the caller
2094 * b) correct the bad sectors on disk
2096 if (failed_bio
->bi_vcnt
> 1) {
2098 * to fulfill b), we need to know the exact failing sectors, as
2099 * we don't want to rewrite any more than the failed ones. thus,
2100 * we need separate read requests for the failed bio
2102 * if the following BUG_ON triggers, our validation request got
2103 * merged. we need separate requests for our algorithm to work.
2105 BUG_ON(failrec
->in_validation
);
2106 failrec
->in_validation
= 1;
2107 failrec
->this_mirror
= failed_mirror
;
2108 read_mode
= READ_SYNC
| REQ_FAILFAST_DEV
;
2111 * we're ready to fulfill a) and b) alongside. get a good copy
2112 * of the failed sector and if we succeed, we have setup
2113 * everything for repair_io_failure to do the rest for us.
2115 if (failrec
->in_validation
) {
2116 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2117 failrec
->in_validation
= 0;
2118 failrec
->this_mirror
= 0;
2120 failrec
->failed_mirror
= failed_mirror
;
2121 failrec
->this_mirror
++;
2122 if (failrec
->this_mirror
== failed_mirror
)
2123 failrec
->this_mirror
++;
2124 read_mode
= READ_SYNC
;
2127 if (!state
|| failrec
->this_mirror
> num_copies
) {
2128 pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
2129 "next_mirror %d, failed_mirror %d\n", state
,
2130 num_copies
, failrec
->this_mirror
, failed_mirror
);
2131 free_io_failure(inode
, failrec
, 0);
2135 bio
= bio_alloc(GFP_NOFS
, 1);
2136 bio
->bi_private
= state
;
2137 bio
->bi_end_io
= failed_bio
->bi_end_io
;
2138 bio
->bi_sector
= failrec
->logical
>> 9;
2139 bio
->bi_bdev
= BTRFS_I(inode
)->root
->fs_info
->fs_devices
->latest_bdev
;
2142 bio_add_page(bio
, page
, failrec
->len
, start
- page_offset(page
));
2144 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2145 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode
,
2146 failrec
->this_mirror
, num_copies
, failrec
->in_validation
);
2148 tree
->ops
->submit_bio_hook(inode
, read_mode
, bio
, failrec
->this_mirror
,
2149 failrec
->bio_flags
, 0);
2153 /* lots and lots of room for performance fixes in the end_bio funcs */
2156 * after a writepage IO is done, we need to:
2157 * clear the uptodate bits on error
2158 * clear the writeback bits in the extent tree for this IO
2159 * end_page_writeback if the page has no more pending IO
2161 * Scheduling is not allowed, so the extent state tree is expected
2162 * to have one and only one object corresponding to this IO.
2164 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
2166 int uptodate
= err
== 0;
2167 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2168 struct extent_io_tree
*tree
;
2175 struct page
*page
= bvec
->bv_page
;
2176 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2178 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
2180 end
= start
+ bvec
->bv_len
- 1;
2182 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
2187 if (--bvec
>= bio
->bi_io_vec
)
2188 prefetchw(&bvec
->bv_page
->flags
);
2189 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
2190 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
2191 end
, NULL
, uptodate
);
2196 if (!uptodate
&& tree
->ops
&&
2197 tree
->ops
->writepage_io_failed_hook
) {
2198 ret
= tree
->ops
->writepage_io_failed_hook(bio
, page
,
2201 uptodate
= (err
== 0);
2207 clear_extent_uptodate(tree
, start
, end
, NULL
, GFP_NOFS
);
2208 ClearPageUptodate(page
);
2213 end_page_writeback(page
);
2215 check_page_writeback(tree
, page
);
2216 } while (bvec
>= bio
->bi_io_vec
);
2222 * after a readpage IO is done, we need to:
2223 * clear the uptodate bits on error
2224 * set the uptodate bits if things worked
2225 * set the page up to date if all extents in the tree are uptodate
2226 * clear the lock bit in the extent tree
2227 * unlock the page if there are no other extents locked for it
2229 * Scheduling is not allowed, so the extent state tree is expected
2230 * to have one and only one object corresponding to this IO.
2232 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
2234 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2235 struct bio_vec
*bvec_end
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2236 struct bio_vec
*bvec
= bio
->bi_io_vec
;
2237 struct extent_io_tree
*tree
;
2247 struct page
*page
= bvec
->bv_page
;
2248 struct extent_state
*cached
= NULL
;
2249 struct extent_state
*state
;
2251 pr_debug("end_bio_extent_readpage: bi_vcnt=%d, idx=%d, err=%d, "
2252 "mirror=%ld\n", bio
->bi_vcnt
, bio
->bi_idx
, err
,
2253 (long int)bio
->bi_bdev
);
2254 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2256 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) +
2258 end
= start
+ bvec
->bv_len
- 1;
2260 if (bvec
->bv_offset
== 0 && bvec
->bv_len
== PAGE_CACHE_SIZE
)
2265 if (++bvec
<= bvec_end
)
2266 prefetchw(&bvec
->bv_page
->flags
);
2268 spin_lock(&tree
->lock
);
2269 state
= find_first_extent_bit_state(tree
, start
, EXTENT_LOCKED
);
2270 if (state
&& state
->start
== start
) {
2272 * take a reference on the state, unlock will drop
2275 cache_state(state
, &cached
);
2277 spin_unlock(&tree
->lock
);
2279 if (uptodate
&& tree
->ops
&& tree
->ops
->readpage_end_io_hook
) {
2280 ret
= tree
->ops
->readpage_end_io_hook(page
, start
, end
,
2285 clean_io_failure(start
, page
);
2289 failed_mirror
= (int)(unsigned long)bio
->bi_bdev
;
2291 * The generic bio_readpage_error handles errors the
2292 * following way: If possible, new read requests are
2293 * created and submitted and will end up in
2294 * end_bio_extent_readpage as well (if we're lucky, not
2295 * in the !uptodate case). In that case it returns 0 and
2296 * we just go on with the next page in our bio. If it
2297 * can't handle the error it will return -EIO and we
2298 * remain responsible for that page.
2300 ret
= bio_readpage_error(bio
, page
, start
, end
,
2301 failed_mirror
, NULL
);
2305 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2308 uncache_state(&cached
);
2311 if (tree
->ops
&& tree
->ops
->readpage_io_failed_hook
) {
2312 ret
= tree
->ops
->readpage_io_failed_hook(
2313 bio
, page
, start
, end
,
2314 failed_mirror
, state
);
2321 set_extent_uptodate(tree
, start
, end
, &cached
,
2324 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2328 SetPageUptodate(page
);
2330 ClearPageUptodate(page
);
2336 check_page_uptodate(tree
, page
);
2338 ClearPageUptodate(page
);
2341 check_page_locked(tree
, page
);
2343 } while (bvec
<= bvec_end
);
2349 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
2354 bio
= bio_alloc(gfp_flags
, nr_vecs
);
2356 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
2357 while (!bio
&& (nr_vecs
/= 2))
2358 bio
= bio_alloc(gfp_flags
, nr_vecs
);
2363 bio
->bi_bdev
= bdev
;
2364 bio
->bi_sector
= first_sector
;
2369 static int submit_one_bio(int rw
, struct bio
*bio
, int mirror_num
,
2370 unsigned long bio_flags
)
2373 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2374 struct page
*page
= bvec
->bv_page
;
2375 struct extent_io_tree
*tree
= bio
->bi_private
;
2378 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) + bvec
->bv_offset
;
2380 bio
->bi_private
= NULL
;
2384 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
2385 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
2386 mirror_num
, bio_flags
, start
);
2388 submit_bio(rw
, bio
);
2390 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
2396 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
2397 struct page
*page
, sector_t sector
,
2398 size_t size
, unsigned long offset
,
2399 struct block_device
*bdev
,
2400 struct bio
**bio_ret
,
2401 unsigned long max_pages
,
2402 bio_end_io_t end_io_func
,
2404 unsigned long prev_bio_flags
,
2405 unsigned long bio_flags
)
2411 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
2412 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2413 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
2415 if (bio_ret
&& *bio_ret
) {
2418 contig
= bio
->bi_sector
== sector
;
2420 contig
= bio
->bi_sector
+ (bio
->bi_size
>> 9) ==
2423 if (prev_bio_flags
!= bio_flags
|| !contig
||
2424 (tree
->ops
&& tree
->ops
->merge_bio_hook
&&
2425 tree
->ops
->merge_bio_hook(page
, offset
, page_size
, bio
,
2427 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2428 ret
= submit_one_bio(rw
, bio
, mirror_num
,
2435 if (this_compressed
)
2438 nr
= bio_get_nr_vecs(bdev
);
2440 bio
= btrfs_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
2444 bio_add_page(bio
, page
, page_size
, offset
);
2445 bio
->bi_end_io
= end_io_func
;
2446 bio
->bi_private
= tree
;
2451 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
2456 void set_page_extent_mapped(struct page
*page
)
2458 if (!PagePrivate(page
)) {
2459 SetPagePrivate(page
);
2460 page_cache_get(page
);
2461 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2465 static void set_page_extent_head(struct page
*page
, unsigned long len
)
2467 WARN_ON(!PagePrivate(page
));
2468 set_page_private(page
, EXTENT_PAGE_PRIVATE_FIRST_PAGE
| len
<< 2);
2472 * basic readpage implementation. Locked extent state structs are inserted
2473 * into the tree that are removed when the IO is done (by the end_io
2476 static int __extent_read_full_page(struct extent_io_tree
*tree
,
2478 get_extent_t
*get_extent
,
2479 struct bio
**bio
, int mirror_num
,
2480 unsigned long *bio_flags
)
2482 struct inode
*inode
= page
->mapping
->host
;
2483 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2484 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2488 u64 last_byte
= i_size_read(inode
);
2492 struct extent_map
*em
;
2493 struct block_device
*bdev
;
2494 struct btrfs_ordered_extent
*ordered
;
2497 size_t pg_offset
= 0;
2499 size_t disk_io_size
;
2500 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2501 unsigned long this_bio_flag
= 0;
2503 set_page_extent_mapped(page
);
2505 if (!PageUptodate(page
)) {
2506 if (cleancache_get_page(page
) == 0) {
2507 BUG_ON(blocksize
!= PAGE_SIZE
);
2514 lock_extent(tree
, start
, end
, GFP_NOFS
);
2515 ordered
= btrfs_lookup_ordered_extent(inode
, start
);
2518 unlock_extent(tree
, start
, end
, GFP_NOFS
);
2519 btrfs_start_ordered_extent(inode
, ordered
, 1);
2520 btrfs_put_ordered_extent(ordered
);
2523 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
2525 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
2528 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
2529 userpage
= kmap_atomic(page
, KM_USER0
);
2530 memset(userpage
+ zero_offset
, 0, iosize
);
2531 flush_dcache_page(page
);
2532 kunmap_atomic(userpage
, KM_USER0
);
2535 while (cur
<= end
) {
2536 if (cur
>= last_byte
) {
2538 struct extent_state
*cached
= NULL
;
2540 iosize
= PAGE_CACHE_SIZE
- pg_offset
;
2541 userpage
= kmap_atomic(page
, KM_USER0
);
2542 memset(userpage
+ pg_offset
, 0, iosize
);
2543 flush_dcache_page(page
);
2544 kunmap_atomic(userpage
, KM_USER0
);
2545 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2547 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2551 em
= get_extent(inode
, page
, pg_offset
, cur
,
2553 if (IS_ERR_OR_NULL(em
)) {
2555 unlock_extent(tree
, cur
, end
, GFP_NOFS
);
2558 extent_offset
= cur
- em
->start
;
2559 BUG_ON(extent_map_end(em
) <= cur
);
2562 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2563 this_bio_flag
= EXTENT_BIO_COMPRESSED
;
2564 extent_set_compress_type(&this_bio_flag
,
2568 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2569 cur_end
= min(extent_map_end(em
) - 1, end
);
2570 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
2571 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2572 disk_io_size
= em
->block_len
;
2573 sector
= em
->block_start
>> 9;
2575 sector
= (em
->block_start
+ extent_offset
) >> 9;
2576 disk_io_size
= iosize
;
2579 block_start
= em
->block_start
;
2580 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2581 block_start
= EXTENT_MAP_HOLE
;
2582 free_extent_map(em
);
2585 /* we've found a hole, just zero and go on */
2586 if (block_start
== EXTENT_MAP_HOLE
) {
2588 struct extent_state
*cached
= NULL
;
2590 userpage
= kmap_atomic(page
, KM_USER0
);
2591 memset(userpage
+ pg_offset
, 0, iosize
);
2592 flush_dcache_page(page
);
2593 kunmap_atomic(userpage
, KM_USER0
);
2595 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2597 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2600 pg_offset
+= iosize
;
2603 /* the get_extent function already copied into the page */
2604 if (test_range_bit(tree
, cur
, cur_end
,
2605 EXTENT_UPTODATE
, 1, NULL
)) {
2606 check_page_uptodate(tree
, page
);
2607 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2609 pg_offset
+= iosize
;
2612 /* we have an inline extent but it didn't get marked up
2613 * to date. Error out
2615 if (block_start
== EXTENT_MAP_INLINE
) {
2617 unlock_extent(tree
, cur
, cur
+ iosize
- 1, GFP_NOFS
);
2619 pg_offset
+= iosize
;
2624 if (tree
->ops
&& tree
->ops
->readpage_io_hook
) {
2625 ret
= tree
->ops
->readpage_io_hook(page
, cur
,
2629 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2631 ret
= submit_extent_page(READ
, tree
, page
,
2632 sector
, disk_io_size
, pg_offset
,
2634 end_bio_extent_readpage
, mirror_num
,
2638 *bio_flags
= this_bio_flag
;
2643 pg_offset
+= iosize
;
2647 if (!PageError(page
))
2648 SetPageUptodate(page
);
2654 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
2655 get_extent_t
*get_extent
, int mirror_num
)
2657 struct bio
*bio
= NULL
;
2658 unsigned long bio_flags
= 0;
2661 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
2664 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
2668 static noinline
void update_nr_written(struct page
*page
,
2669 struct writeback_control
*wbc
,
2670 unsigned long nr_written
)
2672 wbc
->nr_to_write
-= nr_written
;
2673 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
2674 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
2675 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
2679 * the writepage semantics are similar to regular writepage. extent
2680 * records are inserted to lock ranges in the tree, and as dirty areas
2681 * are found, they are marked writeback. Then the lock bits are removed
2682 * and the end_io handler clears the writeback ranges
2684 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
2687 struct inode
*inode
= page
->mapping
->host
;
2688 struct extent_page_data
*epd
= data
;
2689 struct extent_io_tree
*tree
= epd
->tree
;
2690 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2692 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2696 u64 last_byte
= i_size_read(inode
);
2700 struct extent_state
*cached_state
= NULL
;
2701 struct extent_map
*em
;
2702 struct block_device
*bdev
;
2705 size_t pg_offset
= 0;
2707 loff_t i_size
= i_size_read(inode
);
2708 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2714 unsigned long nr_written
= 0;
2715 bool fill_delalloc
= true;
2717 if (wbc
->sync_mode
== WB_SYNC_ALL
)
2718 write_flags
= WRITE_SYNC
;
2720 write_flags
= WRITE
;
2722 trace___extent_writepage(page
, inode
, wbc
);
2724 WARN_ON(!PageLocked(page
));
2726 ClearPageError(page
);
2728 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
2729 if (page
->index
> end_index
||
2730 (page
->index
== end_index
&& !pg_offset
)) {
2731 page
->mapping
->a_ops
->invalidatepage(page
, 0);
2736 if (page
->index
== end_index
) {
2739 userpage
= kmap_atomic(page
, KM_USER0
);
2740 memset(userpage
+ pg_offset
, 0,
2741 PAGE_CACHE_SIZE
- pg_offset
);
2742 kunmap_atomic(userpage
, KM_USER0
);
2743 flush_dcache_page(page
);
2747 set_page_extent_mapped(page
);
2749 if (!tree
->ops
|| !tree
->ops
->fill_delalloc
)
2750 fill_delalloc
= false;
2752 delalloc_start
= start
;
2755 if (!epd
->extent_locked
&& fill_delalloc
) {
2756 u64 delalloc_to_write
= 0;
2758 * make sure the wbc mapping index is at least updated
2761 update_nr_written(page
, wbc
, 0);
2763 while (delalloc_end
< page_end
) {
2764 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
2769 if (nr_delalloc
== 0) {
2770 delalloc_start
= delalloc_end
+ 1;
2773 tree
->ops
->fill_delalloc(inode
, page
, delalloc_start
,
2774 delalloc_end
, &page_started
,
2777 * delalloc_end is already one less than the total
2778 * length, so we don't subtract one from
2781 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
2784 delalloc_start
= delalloc_end
+ 1;
2786 if (wbc
->nr_to_write
< delalloc_to_write
) {
2789 if (delalloc_to_write
< thresh
* 2)
2790 thresh
= delalloc_to_write
;
2791 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
2795 /* did the fill delalloc function already unlock and start
2801 * we've unlocked the page, so we can't update
2802 * the mapping's writeback index, just update
2805 wbc
->nr_to_write
-= nr_written
;
2809 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
2810 ret
= tree
->ops
->writepage_start_hook(page
, start
,
2812 if (ret
== -EAGAIN
) {
2813 redirty_page_for_writepage(wbc
, page
);
2814 update_nr_written(page
, wbc
, nr_written
);
2822 * we don't want to touch the inode after unlocking the page,
2823 * so we update the mapping writeback index now
2825 update_nr_written(page
, wbc
, nr_written
+ 1);
2828 if (last_byte
<= start
) {
2829 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2830 tree
->ops
->writepage_end_io_hook(page
, start
,
2835 blocksize
= inode
->i_sb
->s_blocksize
;
2837 while (cur
<= end
) {
2838 if (cur
>= last_byte
) {
2839 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2840 tree
->ops
->writepage_end_io_hook(page
, cur
,
2844 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
2846 if (IS_ERR_OR_NULL(em
)) {
2851 extent_offset
= cur
- em
->start
;
2852 BUG_ON(extent_map_end(em
) <= cur
);
2854 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2855 iosize
= (iosize
+ blocksize
- 1) & ~((u64
)blocksize
- 1);
2856 sector
= (em
->block_start
+ extent_offset
) >> 9;
2858 block_start
= em
->block_start
;
2859 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
2860 free_extent_map(em
);
2864 * compressed and inline extents are written through other
2867 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
2868 block_start
== EXTENT_MAP_INLINE
) {
2870 * end_io notification does not happen here for
2871 * compressed extents
2873 if (!compressed
&& tree
->ops
&&
2874 tree
->ops
->writepage_end_io_hook
)
2875 tree
->ops
->writepage_end_io_hook(page
, cur
,
2878 else if (compressed
) {
2879 /* we don't want to end_page_writeback on
2880 * a compressed extent. this happens
2887 pg_offset
+= iosize
;
2890 /* leave this out until we have a page_mkwrite call */
2891 if (0 && !test_range_bit(tree
, cur
, cur
+ iosize
- 1,
2892 EXTENT_DIRTY
, 0, NULL
)) {
2894 pg_offset
+= iosize
;
2898 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
2899 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
2907 unsigned long max_nr
= end_index
+ 1;
2909 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
2910 if (!PageWriteback(page
)) {
2911 printk(KERN_ERR
"btrfs warning page %lu not "
2912 "writeback, cur %llu end %llu\n",
2913 page
->index
, (unsigned long long)cur
,
2914 (unsigned long long)end
);
2917 ret
= submit_extent_page(write_flags
, tree
, page
,
2918 sector
, iosize
, pg_offset
,
2919 bdev
, &epd
->bio
, max_nr
,
2920 end_bio_extent_writepage
,
2926 pg_offset
+= iosize
;
2931 /* make sure the mapping tag for page dirty gets cleared */
2932 set_page_writeback(page
);
2933 end_page_writeback(page
);
2939 /* drop our reference on any cached states */
2940 free_extent_state(cached_state
);
2945 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2946 * @mapping: address space structure to write
2947 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2948 * @writepage: function called for each page
2949 * @data: data passed to writepage function
2951 * If a page is already under I/O, write_cache_pages() skips it, even
2952 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2953 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2954 * and msync() need to guarantee that all the data which was dirty at the time
2955 * the call was made get new I/O started against them. If wbc->sync_mode is
2956 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2957 * existing IO to complete.
2959 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
2960 struct address_space
*mapping
,
2961 struct writeback_control
*wbc
,
2962 writepage_t writepage
, void *data
,
2963 void (*flush_fn
)(void *))
2967 int nr_to_write_done
= 0;
2968 struct pagevec pvec
;
2971 pgoff_t end
; /* Inclusive */
2975 pagevec_init(&pvec
, 0);
2976 if (wbc
->range_cyclic
) {
2977 index
= mapping
->writeback_index
; /* Start from prev offset */
2980 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2981 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
2984 if (wbc
->sync_mode
== WB_SYNC_ALL
)
2985 tag
= PAGECACHE_TAG_TOWRITE
;
2987 tag
= PAGECACHE_TAG_DIRTY
;
2989 if (wbc
->sync_mode
== WB_SYNC_ALL
)
2990 tag_pages_for_writeback(mapping
, index
, end
);
2991 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
2992 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
2993 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
2997 for (i
= 0; i
< nr_pages
; i
++) {
2998 struct page
*page
= pvec
.pages
[i
];
3001 * At this point we hold neither mapping->tree_lock nor
3002 * lock on the page itself: the page may be truncated or
3003 * invalidated (changing page->mapping to NULL), or even
3004 * swizzled back from swapper_space to tmpfs file
3008 tree
->ops
->write_cache_pages_lock_hook
) {
3009 tree
->ops
->write_cache_pages_lock_hook(page
,
3012 if (!trylock_page(page
)) {
3018 if (unlikely(page
->mapping
!= mapping
)) {
3023 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3029 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
3030 if (PageWriteback(page
))
3032 wait_on_page_writeback(page
);
3035 if (PageWriteback(page
) ||
3036 !clear_page_dirty_for_io(page
)) {
3041 ret
= (*writepage
)(page
, wbc
, data
);
3043 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
3051 * the filesystem may choose to bump up nr_to_write.
3052 * We have to make sure to honor the new nr_to_write
3055 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3057 pagevec_release(&pvec
);
3060 if (!scanned
&& !done
) {
3062 * We hit the last page and there is more work to be done: wrap
3063 * back to the start of the file
3072 static void flush_epd_write_bio(struct extent_page_data
*epd
)
3076 submit_one_bio(WRITE_SYNC
, epd
->bio
, 0, 0);
3078 submit_one_bio(WRITE
, epd
->bio
, 0, 0);
3083 static noinline
void flush_write_bio(void *data
)
3085 struct extent_page_data
*epd
= data
;
3086 flush_epd_write_bio(epd
);
3089 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3090 get_extent_t
*get_extent
,
3091 struct writeback_control
*wbc
)
3094 struct extent_page_data epd
= {
3097 .get_extent
= get_extent
,
3099 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3102 ret
= __extent_writepage(page
, wbc
, &epd
);
3104 flush_epd_write_bio(&epd
);
3108 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
3109 u64 start
, u64 end
, get_extent_t
*get_extent
,
3113 struct address_space
*mapping
= inode
->i_mapping
;
3115 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
3118 struct extent_page_data epd
= {
3121 .get_extent
= get_extent
,
3123 .sync_io
= mode
== WB_SYNC_ALL
,
3125 struct writeback_control wbc_writepages
= {
3127 .nr_to_write
= nr_pages
* 2,
3128 .range_start
= start
,
3129 .range_end
= end
+ 1,
3132 while (start
<= end
) {
3133 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
3134 if (clear_page_dirty_for_io(page
))
3135 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
3137 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3138 tree
->ops
->writepage_end_io_hook(page
, start
,
3139 start
+ PAGE_CACHE_SIZE
- 1,
3143 page_cache_release(page
);
3144 start
+= PAGE_CACHE_SIZE
;
3147 flush_epd_write_bio(&epd
);
3151 int extent_writepages(struct extent_io_tree
*tree
,
3152 struct address_space
*mapping
,
3153 get_extent_t
*get_extent
,
3154 struct writeback_control
*wbc
)
3157 struct extent_page_data epd
= {
3160 .get_extent
= get_extent
,
3162 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3165 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
3166 __extent_writepage
, &epd
,
3168 flush_epd_write_bio(&epd
);
3172 int extent_readpages(struct extent_io_tree
*tree
,
3173 struct address_space
*mapping
,
3174 struct list_head
*pages
, unsigned nr_pages
,
3175 get_extent_t get_extent
)
3177 struct bio
*bio
= NULL
;
3179 unsigned long bio_flags
= 0;
3181 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
3182 struct page
*page
= list_entry(pages
->prev
, struct page
, lru
);
3184 prefetchw(&page
->flags
);
3185 list_del(&page
->lru
);
3186 if (!add_to_page_cache_lru(page
, mapping
,
3187 page
->index
, GFP_NOFS
)) {
3188 __extent_read_full_page(tree
, page
, get_extent
,
3189 &bio
, 0, &bio_flags
);
3191 page_cache_release(page
);
3193 BUG_ON(!list_empty(pages
));
3195 submit_one_bio(READ
, bio
, 0, bio_flags
);
3200 * basic invalidatepage code, this waits on any locked or writeback
3201 * ranges corresponding to the page, and then deletes any extent state
3202 * records from the tree
3204 int extent_invalidatepage(struct extent_io_tree
*tree
,
3205 struct page
*page
, unsigned long offset
)
3207 struct extent_state
*cached_state
= NULL
;
3208 u64 start
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
);
3209 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3210 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
3212 start
+= (offset
+ blocksize
- 1) & ~(blocksize
- 1);
3216 lock_extent_bits(tree
, start
, end
, 0, &cached_state
, GFP_NOFS
);
3217 wait_on_page_writeback(page
);
3218 clear_extent_bit(tree
, start
, end
,
3219 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
3220 EXTENT_DO_ACCOUNTING
,
3221 1, 1, &cached_state
, GFP_NOFS
);
3226 * a helper for releasepage, this tests for areas of the page that
3227 * are locked or under IO and drops the related state bits if it is safe
3230 int try_release_extent_state(struct extent_map_tree
*map
,
3231 struct extent_io_tree
*tree
, struct page
*page
,
3234 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
3235 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3238 if (test_range_bit(tree
, start
, end
,
3239 EXTENT_IOBITS
, 0, NULL
))
3242 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
3245 * at this point we can safely clear everything except the
3246 * locked bit and the nodatasum bit
3248 ret
= clear_extent_bit(tree
, start
, end
,
3249 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
3252 /* if clear_extent_bit failed for enomem reasons,
3253 * we can't allow the release to continue.
3264 * a helper for releasepage. As long as there are no locked extents
3265 * in the range corresponding to the page, both state records and extent
3266 * map records are removed
3268 int try_release_extent_mapping(struct extent_map_tree
*map
,
3269 struct extent_io_tree
*tree
, struct page
*page
,
3272 struct extent_map
*em
;
3273 u64 start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
3274 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3276 if ((mask
& __GFP_WAIT
) &&
3277 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
3279 while (start
<= end
) {
3280 len
= end
- start
+ 1;
3281 write_lock(&map
->lock
);
3282 em
= lookup_extent_mapping(map
, start
, len
);
3283 if (IS_ERR_OR_NULL(em
)) {
3284 write_unlock(&map
->lock
);
3287 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
3288 em
->start
!= start
) {
3289 write_unlock(&map
->lock
);
3290 free_extent_map(em
);
3293 if (!test_range_bit(tree
, em
->start
,
3294 extent_map_end(em
) - 1,
3295 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
3297 remove_extent_mapping(map
, em
);
3298 /* once for the rb tree */
3299 free_extent_map(em
);
3301 start
= extent_map_end(em
);
3302 write_unlock(&map
->lock
);
3305 free_extent_map(em
);
3308 return try_release_extent_state(map
, tree
, page
, mask
);
3312 * helper function for fiemap, which doesn't want to see any holes.
3313 * This maps until we find something past 'last'
3315 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
3318 get_extent_t
*get_extent
)
3320 u64 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
3321 struct extent_map
*em
;
3328 len
= last
- offset
;
3331 len
= (len
+ sectorsize
- 1) & ~(sectorsize
- 1);
3332 em
= get_extent(inode
, NULL
, 0, offset
, len
, 0);
3333 if (IS_ERR_OR_NULL(em
))
3336 /* if this isn't a hole return it */
3337 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
3338 em
->block_start
!= EXTENT_MAP_HOLE
) {
3342 /* this is a hole, advance to the next extent */
3343 offset
= extent_map_end(em
);
3344 free_extent_map(em
);
3351 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
3352 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
3356 u64 max
= start
+ len
;
3360 u64 last_for_get_extent
= 0;
3362 u64 isize
= i_size_read(inode
);
3363 struct btrfs_key found_key
;
3364 struct extent_map
*em
= NULL
;
3365 struct extent_state
*cached_state
= NULL
;
3366 struct btrfs_path
*path
;
3367 struct btrfs_file_extent_item
*item
;
3372 unsigned long emflags
;
3377 path
= btrfs_alloc_path();
3380 path
->leave_spinning
= 1;
3382 start
= ALIGN(start
, BTRFS_I(inode
)->root
->sectorsize
);
3383 len
= ALIGN(len
, BTRFS_I(inode
)->root
->sectorsize
);
3386 * lookup the last file extent. We're not using i_size here
3387 * because there might be preallocation past i_size
3389 ret
= btrfs_lookup_file_extent(NULL
, BTRFS_I(inode
)->root
,
3390 path
, btrfs_ino(inode
), -1, 0);
3392 btrfs_free_path(path
);
3397 item
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3398 struct btrfs_file_extent_item
);
3399 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
3400 found_type
= btrfs_key_type(&found_key
);
3402 /* No extents, but there might be delalloc bits */
3403 if (found_key
.objectid
!= btrfs_ino(inode
) ||
3404 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
3405 /* have to trust i_size as the end */
3407 last_for_get_extent
= isize
;
3410 * remember the start of the last extent. There are a
3411 * bunch of different factors that go into the length of the
3412 * extent, so its much less complex to remember where it started
3414 last
= found_key
.offset
;
3415 last_for_get_extent
= last
+ 1;
3417 btrfs_free_path(path
);
3420 * we might have some extents allocated but more delalloc past those
3421 * extents. so, we trust isize unless the start of the last extent is
3426 last_for_get_extent
= isize
;
3429 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
, 0,
3430 &cached_state
, GFP_NOFS
);
3432 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
3442 u64 offset_in_extent
;
3444 /* break if the extent we found is outside the range */
3445 if (em
->start
>= max
|| extent_map_end(em
) < off
)
3449 * get_extent may return an extent that starts before our
3450 * requested range. We have to make sure the ranges
3451 * we return to fiemap always move forward and don't
3452 * overlap, so adjust the offsets here
3454 em_start
= max(em
->start
, off
);
3457 * record the offset from the start of the extent
3458 * for adjusting the disk offset below
3460 offset_in_extent
= em_start
- em
->start
;
3461 em_end
= extent_map_end(em
);
3462 em_len
= em_end
- em_start
;
3463 emflags
= em
->flags
;
3468 * bump off for our next call to get_extent
3470 off
= extent_map_end(em
);
3474 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
3476 flags
|= FIEMAP_EXTENT_LAST
;
3477 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
3478 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
3479 FIEMAP_EXTENT_NOT_ALIGNED
);
3480 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
3481 flags
|= (FIEMAP_EXTENT_DELALLOC
|
3482 FIEMAP_EXTENT_UNKNOWN
);
3484 disko
= em
->block_start
+ offset_in_extent
;
3486 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
3487 flags
|= FIEMAP_EXTENT_ENCODED
;
3489 free_extent_map(em
);
3491 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
3492 (last
== (u64
)-1 && isize
<= em_end
)) {
3493 flags
|= FIEMAP_EXTENT_LAST
;
3497 /* now scan forward to see if this is really the last extent. */
3498 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
3505 flags
|= FIEMAP_EXTENT_LAST
;
3508 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
3514 free_extent_map(em
);
3516 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
,
3517 &cached_state
, GFP_NOFS
);
3521 inline struct page
*extent_buffer_page(struct extent_buffer
*eb
,
3525 struct address_space
*mapping
;
3528 return eb
->first_page
;
3529 i
+= eb
->start
>> PAGE_CACHE_SHIFT
;
3530 mapping
= eb
->first_page
->mapping
;
3535 * extent_buffer_page is only called after pinning the page
3536 * by increasing the reference count. So we know the page must
3537 * be in the radix tree.
3540 p
= radix_tree_lookup(&mapping
->page_tree
, i
);
3546 inline unsigned long num_extent_pages(u64 start
, u64 len
)
3548 return ((start
+ len
+ PAGE_CACHE_SIZE
- 1) >> PAGE_CACHE_SHIFT
) -
3549 (start
>> PAGE_CACHE_SHIFT
);
3552 static struct extent_buffer
*__alloc_extent_buffer(struct extent_io_tree
*tree
,
3557 struct extent_buffer
*eb
= NULL
;
3559 unsigned long flags
;
3562 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
3567 rwlock_init(&eb
->lock
);
3568 atomic_set(&eb
->write_locks
, 0);
3569 atomic_set(&eb
->read_locks
, 0);
3570 atomic_set(&eb
->blocking_readers
, 0);
3571 atomic_set(&eb
->blocking_writers
, 0);
3572 atomic_set(&eb
->spinning_readers
, 0);
3573 atomic_set(&eb
->spinning_writers
, 0);
3574 init_waitqueue_head(&eb
->write_lock_wq
);
3575 init_waitqueue_head(&eb
->read_lock_wq
);
3578 spin_lock_irqsave(&leak_lock
, flags
);
3579 list_add(&eb
->leak_list
, &buffers
);
3580 spin_unlock_irqrestore(&leak_lock
, flags
);
3582 atomic_set(&eb
->refs
, 1);
3587 static void __free_extent_buffer(struct extent_buffer
*eb
)
3590 unsigned long flags
;
3591 spin_lock_irqsave(&leak_lock
, flags
);
3592 list_del(&eb
->leak_list
);
3593 spin_unlock_irqrestore(&leak_lock
, flags
);
3595 kmem_cache_free(extent_buffer_cache
, eb
);
3599 * Helper for releasing extent buffer page.
3601 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
,
3602 unsigned long start_idx
)
3604 unsigned long index
;
3607 if (!eb
->first_page
)
3610 index
= num_extent_pages(eb
->start
, eb
->len
);
3611 if (start_idx
>= index
)
3616 page
= extent_buffer_page(eb
, index
);
3618 page_cache_release(page
);
3619 } while (index
!= start_idx
);
3623 * Helper for releasing the extent buffer.
3625 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
3627 btrfs_release_extent_buffer_page(eb
, 0);
3628 __free_extent_buffer(eb
);
3631 struct extent_buffer
*alloc_extent_buffer(struct extent_io_tree
*tree
,
3632 u64 start
, unsigned long len
,
3635 unsigned long num_pages
= num_extent_pages(start
, len
);
3637 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
3638 struct extent_buffer
*eb
;
3639 struct extent_buffer
*exists
= NULL
;
3641 struct address_space
*mapping
= tree
->mapping
;
3646 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
3647 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
3649 mark_page_accessed(eb
->first_page
);
3654 eb
= __alloc_extent_buffer(tree
, start
, len
, GFP_NOFS
);
3659 eb
->first_page
= page0
;
3662 page_cache_get(page0
);
3663 mark_page_accessed(page0
);
3664 set_page_extent_mapped(page0
);
3665 set_page_extent_head(page0
, len
);
3666 uptodate
= PageUptodate(page0
);
3670 for (; i
< num_pages
; i
++, index
++) {
3671 p
= find_or_create_page(mapping
, index
, GFP_NOFS
);
3676 set_page_extent_mapped(p
);
3677 mark_page_accessed(p
);
3680 set_page_extent_head(p
, len
);
3682 set_page_private(p
, EXTENT_PAGE_PRIVATE
);
3684 if (!PageUptodate(p
))
3688 * see below about how we avoid a nasty race with release page
3689 * and why we unlock later
3695 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3697 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
3701 spin_lock(&tree
->buffer_lock
);
3702 ret
= radix_tree_insert(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
, eb
);
3703 if (ret
== -EEXIST
) {
3704 exists
= radix_tree_lookup(&tree
->buffer
,
3705 start
>> PAGE_CACHE_SHIFT
);
3706 /* add one reference for the caller */
3707 atomic_inc(&exists
->refs
);
3708 spin_unlock(&tree
->buffer_lock
);
3709 radix_tree_preload_end();
3712 /* add one reference for the tree */
3713 atomic_inc(&eb
->refs
);
3714 spin_unlock(&tree
->buffer_lock
);
3715 radix_tree_preload_end();
3718 * there is a race where release page may have
3719 * tried to find this extent buffer in the radix
3720 * but failed. It will tell the VM it is safe to
3721 * reclaim the, and it will clear the page private bit.
3722 * We must make sure to set the page private bit properly
3723 * after the extent buffer is in the radix tree so
3724 * it doesn't get lost
3726 set_page_extent_mapped(eb
->first_page
);
3727 set_page_extent_head(eb
->first_page
, eb
->len
);
3729 unlock_page(eb
->first_page
);
3733 if (eb
->first_page
&& !page0
)
3734 unlock_page(eb
->first_page
);
3736 if (!atomic_dec_and_test(&eb
->refs
))
3738 btrfs_release_extent_buffer(eb
);
3742 struct extent_buffer
*find_extent_buffer(struct extent_io_tree
*tree
,
3743 u64 start
, unsigned long len
)
3745 struct extent_buffer
*eb
;
3748 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
3749 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
3751 mark_page_accessed(eb
->first_page
);
3759 void free_extent_buffer(struct extent_buffer
*eb
)
3764 if (!atomic_dec_and_test(&eb
->refs
))
3770 int clear_extent_buffer_dirty(struct extent_io_tree
*tree
,
3771 struct extent_buffer
*eb
)
3774 unsigned long num_pages
;
3777 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3779 for (i
= 0; i
< num_pages
; i
++) {
3780 page
= extent_buffer_page(eb
, i
);
3781 if (!PageDirty(page
))
3785 WARN_ON(!PagePrivate(page
));
3787 set_page_extent_mapped(page
);
3789 set_page_extent_head(page
, eb
->len
);
3791 clear_page_dirty_for_io(page
);
3792 spin_lock_irq(&page
->mapping
->tree_lock
);
3793 if (!PageDirty(page
)) {
3794 radix_tree_tag_clear(&page
->mapping
->page_tree
,
3796 PAGECACHE_TAG_DIRTY
);
3798 spin_unlock_irq(&page
->mapping
->tree_lock
);
3799 ClearPageError(page
);
3805 int set_extent_buffer_dirty(struct extent_io_tree
*tree
,
3806 struct extent_buffer
*eb
)
3809 unsigned long num_pages
;
3812 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
3813 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3814 for (i
= 0; i
< num_pages
; i
++)
3815 __set_page_dirty_nobuffers(extent_buffer_page(eb
, i
));
3819 static int __eb_straddles_pages(u64 start
, u64 len
)
3821 if (len
< PAGE_CACHE_SIZE
)
3823 if (start
& (PAGE_CACHE_SIZE
- 1))
3825 if ((start
+ len
) & (PAGE_CACHE_SIZE
- 1))
3830 static int eb_straddles_pages(struct extent_buffer
*eb
)
3832 return __eb_straddles_pages(eb
->start
, eb
->len
);
3835 int clear_extent_buffer_uptodate(struct extent_io_tree
*tree
,
3836 struct extent_buffer
*eb
,
3837 struct extent_state
**cached_state
)
3841 unsigned long num_pages
;
3843 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3844 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3846 if (eb_straddles_pages(eb
)) {
3847 clear_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3848 cached_state
, GFP_NOFS
);
3850 for (i
= 0; i
< num_pages
; i
++) {
3851 page
= extent_buffer_page(eb
, i
);
3853 ClearPageUptodate(page
);
3858 int set_extent_buffer_uptodate(struct extent_io_tree
*tree
,
3859 struct extent_buffer
*eb
)
3863 unsigned long num_pages
;
3865 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3867 if (eb_straddles_pages(eb
)) {
3868 set_extent_uptodate(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3871 for (i
= 0; i
< num_pages
; i
++) {
3872 page
= extent_buffer_page(eb
, i
);
3873 if ((i
== 0 && (eb
->start
& (PAGE_CACHE_SIZE
- 1))) ||
3874 ((i
== num_pages
- 1) &&
3875 ((eb
->start
+ eb
->len
) & (PAGE_CACHE_SIZE
- 1)))) {
3876 check_page_uptodate(tree
, page
);
3879 SetPageUptodate(page
);
3884 int extent_range_uptodate(struct extent_io_tree
*tree
,
3889 int pg_uptodate
= 1;
3891 unsigned long index
;
3893 if (__eb_straddles_pages(start
, end
- start
+ 1)) {
3894 ret
= test_range_bit(tree
, start
, end
,
3895 EXTENT_UPTODATE
, 1, NULL
);
3899 while (start
<= end
) {
3900 index
= start
>> PAGE_CACHE_SHIFT
;
3901 page
= find_get_page(tree
->mapping
, index
);
3902 uptodate
= PageUptodate(page
);
3903 page_cache_release(page
);
3908 start
+= PAGE_CACHE_SIZE
;
3913 int extent_buffer_uptodate(struct extent_io_tree
*tree
,
3914 struct extent_buffer
*eb
,
3915 struct extent_state
*cached_state
)
3918 unsigned long num_pages
;
3921 int pg_uptodate
= 1;
3923 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
3926 if (eb_straddles_pages(eb
)) {
3927 ret
= test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3928 EXTENT_UPTODATE
, 1, cached_state
);
3933 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3934 for (i
= 0; i
< num_pages
; i
++) {
3935 page
= extent_buffer_page(eb
, i
);
3936 if (!PageUptodate(page
)) {
3944 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
3945 struct extent_buffer
*eb
, u64 start
, int wait
,
3946 get_extent_t
*get_extent
, int mirror_num
)
3949 unsigned long start_i
;
3953 int locked_pages
= 0;
3954 int all_uptodate
= 1;
3955 int inc_all_pages
= 0;
3956 unsigned long num_pages
;
3957 struct bio
*bio
= NULL
;
3958 unsigned long bio_flags
= 0;
3960 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
3963 if (eb_straddles_pages(eb
)) {
3964 if (test_range_bit(tree
, eb
->start
, eb
->start
+ eb
->len
- 1,
3965 EXTENT_UPTODATE
, 1, NULL
)) {
3971 WARN_ON(start
< eb
->start
);
3972 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
3973 (eb
->start
>> PAGE_CACHE_SHIFT
);
3978 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3979 for (i
= start_i
; i
< num_pages
; i
++) {
3980 page
= extent_buffer_page(eb
, i
);
3981 if (wait
== WAIT_NONE
) {
3982 if (!trylock_page(page
))
3988 if (!PageUptodate(page
))
3993 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
3997 for (i
= start_i
; i
< num_pages
; i
++) {
3998 page
= extent_buffer_page(eb
, i
);
4000 WARN_ON(!PagePrivate(page
));
4002 set_page_extent_mapped(page
);
4004 set_page_extent_head(page
, eb
->len
);
4007 page_cache_get(page
);
4008 if (!PageUptodate(page
)) {
4011 ClearPageError(page
);
4012 err
= __extent_read_full_page(tree
, page
,
4014 mirror_num
, &bio_flags
);
4023 submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
4025 if (ret
|| wait
!= WAIT_COMPLETE
)
4028 for (i
= start_i
; i
< num_pages
; i
++) {
4029 page
= extent_buffer_page(eb
, i
);
4030 wait_on_page_locked(page
);
4031 if (!PageUptodate(page
))
4036 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4041 while (locked_pages
> 0) {
4042 page
= extent_buffer_page(eb
, i
);
4050 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
4051 unsigned long start
,
4058 char *dst
= (char *)dstv
;
4059 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4060 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4062 WARN_ON(start
> eb
->len
);
4063 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4065 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4068 page
= extent_buffer_page(eb
, i
);
4070 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4071 kaddr
= page_address(page
);
4072 memcpy(dst
, kaddr
+ offset
, cur
);
4081 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
4082 unsigned long min_len
, char **map
,
4083 unsigned long *map_start
,
4084 unsigned long *map_len
)
4086 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
4089 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4090 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4091 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
4098 offset
= start_offset
;
4102 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
4105 if (start
+ min_len
> eb
->len
) {
4106 printk(KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
4107 "wanted %lu %lu\n", (unsigned long long)eb
->start
,
4108 eb
->len
, start
, min_len
);
4113 p
= extent_buffer_page(eb
, i
);
4114 kaddr
= page_address(p
);
4115 *map
= kaddr
+ offset
;
4116 *map_len
= PAGE_CACHE_SIZE
- offset
;
4120 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
4121 unsigned long start
,
4128 char *ptr
= (char *)ptrv
;
4129 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4130 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4133 WARN_ON(start
> eb
->len
);
4134 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4136 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4139 page
= extent_buffer_page(eb
, i
);
4141 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
4143 kaddr
= page_address(page
);
4144 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
4156 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
4157 unsigned long start
, unsigned long len
)
4163 char *src
= (char *)srcv
;
4164 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4165 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4167 WARN_ON(start
> eb
->len
);
4168 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4170 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4173 page
= extent_buffer_page(eb
, i
);
4174 WARN_ON(!PageUptodate(page
));
4176 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
4177 kaddr
= page_address(page
);
4178 memcpy(kaddr
+ offset
, src
, cur
);
4187 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
4188 unsigned long start
, unsigned long len
)
4194 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4195 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
4197 WARN_ON(start
> eb
->len
);
4198 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
4200 offset
= (start_offset
+ start
) & ((unsigned long)PAGE_CACHE_SIZE
- 1);
4203 page
= extent_buffer_page(eb
, i
);
4204 WARN_ON(!PageUptodate(page
));
4206 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
4207 kaddr
= page_address(page
);
4208 memset(kaddr
+ offset
, c
, cur
);
4216 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
4217 unsigned long dst_offset
, unsigned long src_offset
,
4220 u64 dst_len
= dst
->len
;
4225 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4226 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
4228 WARN_ON(src
->len
!= dst_len
);
4230 offset
= (start_offset
+ dst_offset
) &
4231 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4234 page
= extent_buffer_page(dst
, i
);
4235 WARN_ON(!PageUptodate(page
));
4237 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
4239 kaddr
= page_address(page
);
4240 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
4249 static void move_pages(struct page
*dst_page
, struct page
*src_page
,
4250 unsigned long dst_off
, unsigned long src_off
,
4253 char *dst_kaddr
= page_address(dst_page
);
4254 if (dst_page
== src_page
) {
4255 memmove(dst_kaddr
+ dst_off
, dst_kaddr
+ src_off
, len
);
4257 char *src_kaddr
= page_address(src_page
);
4258 char *p
= dst_kaddr
+ dst_off
+ len
;
4259 char *s
= src_kaddr
+ src_off
+ len
;
4266 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
4268 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
4269 return distance
< len
;
4272 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
4273 unsigned long dst_off
, unsigned long src_off
,
4276 char *dst_kaddr
= page_address(dst_page
);
4279 if (dst_page
!= src_page
) {
4280 src_kaddr
= page_address(src_page
);
4282 src_kaddr
= dst_kaddr
;
4283 BUG_ON(areas_overlap(src_off
, dst_off
, len
));
4286 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
4289 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
4290 unsigned long src_offset
, unsigned long len
)
4293 size_t dst_off_in_page
;
4294 size_t src_off_in_page
;
4295 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4296 unsigned long dst_i
;
4297 unsigned long src_i
;
4299 if (src_offset
+ len
> dst
->len
) {
4300 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
4301 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
4304 if (dst_offset
+ len
> dst
->len
) {
4305 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
4306 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
4311 dst_off_in_page
= (start_offset
+ dst_offset
) &
4312 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4313 src_off_in_page
= (start_offset
+ src_offset
) &
4314 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4316 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
4317 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
4319 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
4321 cur
= min_t(unsigned long, cur
,
4322 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
4324 copy_pages(extent_buffer_page(dst
, dst_i
),
4325 extent_buffer_page(dst
, src_i
),
4326 dst_off_in_page
, src_off_in_page
, cur
);
4334 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
4335 unsigned long src_offset
, unsigned long len
)
4338 size_t dst_off_in_page
;
4339 size_t src_off_in_page
;
4340 unsigned long dst_end
= dst_offset
+ len
- 1;
4341 unsigned long src_end
= src_offset
+ len
- 1;
4342 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
4343 unsigned long dst_i
;
4344 unsigned long src_i
;
4346 if (src_offset
+ len
> dst
->len
) {
4347 printk(KERN_ERR
"btrfs memmove bogus src_offset %lu move "
4348 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
4351 if (dst_offset
+ len
> dst
->len
) {
4352 printk(KERN_ERR
"btrfs memmove bogus dst_offset %lu move "
4353 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
4356 if (!areas_overlap(src_offset
, dst_offset
, len
)) {
4357 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
4361 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
4362 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
4364 dst_off_in_page
= (start_offset
+ dst_end
) &
4365 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4366 src_off_in_page
= (start_offset
+ src_end
) &
4367 ((unsigned long)PAGE_CACHE_SIZE
- 1);
4369 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
4370 cur
= min(cur
, dst_off_in_page
+ 1);
4371 move_pages(extent_buffer_page(dst
, dst_i
),
4372 extent_buffer_page(dst
, src_i
),
4373 dst_off_in_page
- cur
+ 1,
4374 src_off_in_page
- cur
+ 1, cur
);
4382 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
4384 struct extent_buffer
*eb
=
4385 container_of(head
, struct extent_buffer
, rcu_head
);
4387 btrfs_release_extent_buffer(eb
);
4390 int try_release_extent_buffer(struct extent_io_tree
*tree
, struct page
*page
)
4392 u64 start
= page_offset(page
);
4393 struct extent_buffer
*eb
;
4396 spin_lock(&tree
->buffer_lock
);
4397 eb
= radix_tree_lookup(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4399 spin_unlock(&tree
->buffer_lock
);
4403 if (test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
4409 * set @eb->refs to 0 if it is already 1, and then release the @eb.
4412 if (atomic_cmpxchg(&eb
->refs
, 1, 0) != 1) {
4417 radix_tree_delete(&tree
->buffer
, start
>> PAGE_CACHE_SHIFT
);
4419 spin_unlock(&tree
->buffer_lock
);
4421 /* at this point we can safely release the extent buffer */
4422 if (atomic_read(&eb
->refs
) == 0)
4423 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);