1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/spinlock.h>
8 #include <linux/blkdev.h>
9 #include <linux/swap.h>
10 #include <linux/writeback.h>
11 #include <linux/pagevec.h>
12 #include <linux/prefetch.h>
13 #include <linux/cleancache.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
17 #include "btrfs_inode.h"
19 #include "check-integrity.h"
21 #include "rcu-string.h"
24 static struct kmem_cache
*extent_state_cache
;
25 static struct kmem_cache
*extent_buffer_cache
;
26 static struct bio_set
*btrfs_bioset
;
28 static inline bool extent_state_in_tree(const struct extent_state
*state
)
30 return !RB_EMPTY_NODE(&state
->rb_node
);
33 #ifdef CONFIG_BTRFS_DEBUG
34 static LIST_HEAD(buffers
);
35 static LIST_HEAD(states
);
37 static DEFINE_SPINLOCK(leak_lock
);
40 void btrfs_leak_debug_add(struct list_head
*new, struct list_head
*head
)
44 spin_lock_irqsave(&leak_lock
, flags
);
46 spin_unlock_irqrestore(&leak_lock
, flags
);
50 void btrfs_leak_debug_del(struct list_head
*entry
)
54 spin_lock_irqsave(&leak_lock
, flags
);
56 spin_unlock_irqrestore(&leak_lock
, flags
);
60 void btrfs_leak_debug_check(void)
62 struct extent_state
*state
;
63 struct extent_buffer
*eb
;
65 while (!list_empty(&states
)) {
66 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
67 pr_err("BTRFS: state leak: start %llu end %llu state %lu in tree %d refs %d\n",
68 state
->start
, state
->end
, state
->state
,
69 extent_state_in_tree(state
),
70 atomic_read(&state
->refs
));
71 list_del(&state
->leak_list
);
72 kmem_cache_free(extent_state_cache
, state
);
75 while (!list_empty(&buffers
)) {
76 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
77 printk(KERN_ERR
"BTRFS: buffer leak start %llu len %lu "
79 eb
->start
, eb
->len
, atomic_read(&eb
->refs
));
80 list_del(&eb
->leak_list
);
81 kmem_cache_free(extent_buffer_cache
, eb
);
85 #define btrfs_debug_check_extent_io_range(tree, start, end) \
86 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
87 static inline void __btrfs_debug_check_extent_io_range(const char *caller
,
88 struct extent_io_tree
*tree
, u64 start
, u64 end
)
96 inode
= tree
->mapping
->host
;
97 isize
= i_size_read(inode
);
98 if (end
>= PAGE_SIZE
&& (end
% 2) == 0 && end
!= isize
- 1) {
99 printk_ratelimited(KERN_DEBUG
100 "BTRFS: %s: ino %llu isize %llu odd range [%llu,%llu]\n",
101 caller
, btrfs_ino(inode
), isize
, start
, end
);
105 #define btrfs_leak_debug_add(new, head) do {} while (0)
106 #define btrfs_leak_debug_del(entry) do {} while (0)
107 #define btrfs_leak_debug_check() do {} while (0)
108 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
111 #define BUFFER_LRU_MAX 64
116 struct rb_node rb_node
;
119 struct extent_page_data
{
121 struct extent_io_tree
*tree
;
122 get_extent_t
*get_extent
;
123 unsigned long bio_flags
;
125 /* tells writepage not to lock the state bits for this range
126 * it still does the unlocking
128 unsigned int extent_locked
:1;
130 /* tells the submit_bio code to use a WRITE_SYNC */
131 unsigned int sync_io
:1;
134 static noinline
void flush_write_bio(void *data
);
135 static inline struct btrfs_fs_info
*
136 tree_fs_info(struct extent_io_tree
*tree
)
140 return btrfs_sb(tree
->mapping
->host
->i_sb
);
143 int __init
extent_io_init(void)
145 extent_state_cache
= kmem_cache_create("btrfs_extent_state",
146 sizeof(struct extent_state
), 0,
147 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
148 if (!extent_state_cache
)
151 extent_buffer_cache
= kmem_cache_create("btrfs_extent_buffer",
152 sizeof(struct extent_buffer
), 0,
153 SLAB_RECLAIM_ACCOUNT
| SLAB_MEM_SPREAD
, NULL
);
154 if (!extent_buffer_cache
)
155 goto free_state_cache
;
157 btrfs_bioset
= bioset_create(BIO_POOL_SIZE
,
158 offsetof(struct btrfs_io_bio
, bio
));
160 goto free_buffer_cache
;
162 if (bioset_integrity_create(btrfs_bioset
, BIO_POOL_SIZE
))
168 bioset_free(btrfs_bioset
);
172 kmem_cache_destroy(extent_buffer_cache
);
173 extent_buffer_cache
= NULL
;
176 kmem_cache_destroy(extent_state_cache
);
177 extent_state_cache
= NULL
;
181 void extent_io_exit(void)
183 btrfs_leak_debug_check();
186 * Make sure all delayed rcu free are flushed before we
190 if (extent_state_cache
)
191 kmem_cache_destroy(extent_state_cache
);
192 if (extent_buffer_cache
)
193 kmem_cache_destroy(extent_buffer_cache
);
195 bioset_free(btrfs_bioset
);
198 void extent_io_tree_init(struct extent_io_tree
*tree
,
199 struct address_space
*mapping
)
201 tree
->state
= RB_ROOT
;
203 tree
->dirty_bytes
= 0;
204 spin_lock_init(&tree
->lock
);
205 tree
->mapping
= mapping
;
208 static struct extent_state
*alloc_extent_state(gfp_t mask
)
210 struct extent_state
*state
;
212 state
= kmem_cache_alloc(extent_state_cache
, mask
);
217 RB_CLEAR_NODE(&state
->rb_node
);
218 btrfs_leak_debug_add(&state
->leak_list
, &states
);
219 atomic_set(&state
->refs
, 1);
220 init_waitqueue_head(&state
->wq
);
221 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
225 void free_extent_state(struct extent_state
*state
)
229 if (atomic_dec_and_test(&state
->refs
)) {
230 WARN_ON(extent_state_in_tree(state
));
231 btrfs_leak_debug_del(&state
->leak_list
);
232 trace_free_extent_state(state
, _RET_IP_
);
233 kmem_cache_free(extent_state_cache
, state
);
237 static struct rb_node
*tree_insert(struct rb_root
*root
,
238 struct rb_node
*search_start
,
240 struct rb_node
*node
,
241 struct rb_node
***p_in
,
242 struct rb_node
**parent_in
)
245 struct rb_node
*parent
= NULL
;
246 struct tree_entry
*entry
;
248 if (p_in
&& parent_in
) {
254 p
= search_start
? &search_start
: &root
->rb_node
;
257 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
259 if (offset
< entry
->start
)
261 else if (offset
> entry
->end
)
268 rb_link_node(node
, parent
, p
);
269 rb_insert_color(node
, root
);
273 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
274 struct rb_node
**prev_ret
,
275 struct rb_node
**next_ret
,
276 struct rb_node
***p_ret
,
277 struct rb_node
**parent_ret
)
279 struct rb_root
*root
= &tree
->state
;
280 struct rb_node
**n
= &root
->rb_node
;
281 struct rb_node
*prev
= NULL
;
282 struct rb_node
*orig_prev
= NULL
;
283 struct tree_entry
*entry
;
284 struct tree_entry
*prev_entry
= NULL
;
288 entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
291 if (offset
< entry
->start
)
293 else if (offset
> entry
->end
)
306 while (prev
&& offset
> prev_entry
->end
) {
307 prev
= rb_next(prev
);
308 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
315 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
316 while (prev
&& offset
< prev_entry
->start
) {
317 prev
= rb_prev(prev
);
318 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
325 static inline struct rb_node
*
326 tree_search_for_insert(struct extent_io_tree
*tree
,
328 struct rb_node
***p_ret
,
329 struct rb_node
**parent_ret
)
331 struct rb_node
*prev
= NULL
;
334 ret
= __etree_search(tree
, offset
, &prev
, NULL
, p_ret
, parent_ret
);
340 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
343 return tree_search_for_insert(tree
, offset
, NULL
, NULL
);
346 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
347 struct extent_state
*other
)
349 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
350 tree
->ops
->merge_extent_hook(tree
->mapping
->host
, new,
355 * utility function to look for merge candidates inside a given range.
356 * Any extents with matching state are merged together into a single
357 * extent in the tree. Extents with EXTENT_IO in their state field
358 * are not merged because the end_io handlers need to be able to do
359 * operations on them without sleeping (or doing allocations/splits).
361 * This should be called with the tree lock held.
363 static void merge_state(struct extent_io_tree
*tree
,
364 struct extent_state
*state
)
366 struct extent_state
*other
;
367 struct rb_node
*other_node
;
369 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
372 other_node
= rb_prev(&state
->rb_node
);
374 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
375 if (other
->end
== state
->start
- 1 &&
376 other
->state
== state
->state
) {
377 merge_cb(tree
, state
, other
);
378 state
->start
= other
->start
;
379 rb_erase(&other
->rb_node
, &tree
->state
);
380 RB_CLEAR_NODE(&other
->rb_node
);
381 free_extent_state(other
);
384 other_node
= rb_next(&state
->rb_node
);
386 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
387 if (other
->start
== state
->end
+ 1 &&
388 other
->state
== state
->state
) {
389 merge_cb(tree
, state
, other
);
390 state
->end
= other
->end
;
391 rb_erase(&other
->rb_node
, &tree
->state
);
392 RB_CLEAR_NODE(&other
->rb_node
);
393 free_extent_state(other
);
398 static void set_state_cb(struct extent_io_tree
*tree
,
399 struct extent_state
*state
, unsigned long *bits
)
401 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
402 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
, bits
);
405 static void clear_state_cb(struct extent_io_tree
*tree
,
406 struct extent_state
*state
, unsigned long *bits
)
408 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
409 tree
->ops
->clear_bit_hook(tree
->mapping
->host
, state
, bits
);
412 static void set_state_bits(struct extent_io_tree
*tree
,
413 struct extent_state
*state
, unsigned long *bits
);
416 * insert an extent_state struct into the tree. 'bits' are set on the
417 * struct before it is inserted.
419 * This may return -EEXIST if the extent is already there, in which case the
420 * state struct is freed.
422 * The tree lock is not taken internally. This is a utility function and
423 * probably isn't what you want to call (see set/clear_extent_bit).
425 static int insert_state(struct extent_io_tree
*tree
,
426 struct extent_state
*state
, u64 start
, u64 end
,
428 struct rb_node
**parent
,
431 struct rb_node
*node
;
434 WARN(1, KERN_ERR
"BTRFS: end < start %llu %llu\n",
436 state
->start
= start
;
439 set_state_bits(tree
, state
, bits
);
441 node
= tree_insert(&tree
->state
, NULL
, end
, &state
->rb_node
, p
, parent
);
443 struct extent_state
*found
;
444 found
= rb_entry(node
, struct extent_state
, rb_node
);
445 printk(KERN_ERR
"BTRFS: found node %llu %llu on insert of "
447 found
->start
, found
->end
, start
, end
);
450 merge_state(tree
, state
);
454 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
457 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
458 tree
->ops
->split_extent_hook(tree
->mapping
->host
, orig
, split
);
462 * split a given extent state struct in two, inserting the preallocated
463 * struct 'prealloc' as the newly created second half. 'split' indicates an
464 * offset inside 'orig' where it should be split.
467 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
468 * are two extent state structs in the tree:
469 * prealloc: [orig->start, split - 1]
470 * orig: [ split, orig->end ]
472 * The tree locks are not taken by this function. They need to be held
475 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
476 struct extent_state
*prealloc
, u64 split
)
478 struct rb_node
*node
;
480 split_cb(tree
, orig
, split
);
482 prealloc
->start
= orig
->start
;
483 prealloc
->end
= split
- 1;
484 prealloc
->state
= orig
->state
;
487 node
= tree_insert(&tree
->state
, &orig
->rb_node
, prealloc
->end
,
488 &prealloc
->rb_node
, NULL
, NULL
);
490 free_extent_state(prealloc
);
496 static struct extent_state
*next_state(struct extent_state
*state
)
498 struct rb_node
*next
= rb_next(&state
->rb_node
);
500 return rb_entry(next
, struct extent_state
, rb_node
);
506 * utility function to clear some bits in an extent state struct.
507 * it will optionally wake up any one waiting on this state (wake == 1).
509 * If no bits are set on the state struct after clearing things, the
510 * struct is freed and removed from the tree
512 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
513 struct extent_state
*state
,
514 unsigned long *bits
, int wake
)
516 struct extent_state
*next
;
517 unsigned long bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
519 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
520 u64 range
= state
->end
- state
->start
+ 1;
521 WARN_ON(range
> tree
->dirty_bytes
);
522 tree
->dirty_bytes
-= range
;
524 clear_state_cb(tree
, state
, bits
);
525 state
->state
&= ~bits_to_clear
;
528 if (state
->state
== 0) {
529 next
= next_state(state
);
530 if (extent_state_in_tree(state
)) {
531 rb_erase(&state
->rb_node
, &tree
->state
);
532 RB_CLEAR_NODE(&state
->rb_node
);
533 free_extent_state(state
);
538 merge_state(tree
, state
);
539 next
= next_state(state
);
544 static struct extent_state
*
545 alloc_extent_state_atomic(struct extent_state
*prealloc
)
548 prealloc
= alloc_extent_state(GFP_ATOMIC
);
553 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
555 btrfs_panic(tree_fs_info(tree
), err
, "Locking error: "
556 "Extent tree was modified by another "
557 "thread while locked.");
561 * clear some bits on a range in the tree. This may require splitting
562 * or inserting elements in the tree, so the gfp mask is used to
563 * indicate which allocations or sleeping are allowed.
565 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
566 * the given range from the tree regardless of state (ie for truncate).
568 * the range [start, end] is inclusive.
570 * This takes the tree lock, and returns 0 on success and < 0 on error.
572 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
573 unsigned long bits
, int wake
, int delete,
574 struct extent_state
**cached_state
,
577 struct extent_state
*state
;
578 struct extent_state
*cached
;
579 struct extent_state
*prealloc
= NULL
;
580 struct rb_node
*node
;
585 btrfs_debug_check_extent_io_range(tree
, start
, end
);
587 if (bits
& EXTENT_DELALLOC
)
588 bits
|= EXTENT_NORESERVE
;
591 bits
|= ~EXTENT_CTLBITS
;
592 bits
|= EXTENT_FIRST_DELALLOC
;
594 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
597 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
598 prealloc
= alloc_extent_state(mask
);
603 spin_lock(&tree
->lock
);
605 cached
= *cached_state
;
608 *cached_state
= NULL
;
612 if (cached
&& extent_state_in_tree(cached
) &&
613 cached
->start
<= start
&& cached
->end
> start
) {
615 atomic_dec(&cached
->refs
);
620 free_extent_state(cached
);
623 * this search will find the extents that end after
626 node
= tree_search(tree
, start
);
629 state
= rb_entry(node
, struct extent_state
, rb_node
);
631 if (state
->start
> end
)
633 WARN_ON(state
->end
< start
);
634 last_end
= state
->end
;
636 /* the state doesn't have the wanted bits, go ahead */
637 if (!(state
->state
& bits
)) {
638 state
= next_state(state
);
643 * | ---- desired range ---- |
645 * | ------------- state -------------- |
647 * We need to split the extent we found, and may flip
648 * bits on second half.
650 * If the extent we found extends past our range, we
651 * just split and search again. It'll get split again
652 * the next time though.
654 * If the extent we found is inside our range, we clear
655 * the desired bit on it.
658 if (state
->start
< start
) {
659 prealloc
= alloc_extent_state_atomic(prealloc
);
661 err
= split_state(tree
, state
, prealloc
, start
);
663 extent_io_tree_panic(tree
, err
);
668 if (state
->end
<= end
) {
669 state
= clear_state_bit(tree
, state
, &bits
, wake
);
675 * | ---- desired range ---- |
677 * We need to split the extent, and clear the bit
680 if (state
->start
<= end
&& state
->end
> end
) {
681 prealloc
= alloc_extent_state_atomic(prealloc
);
683 err
= split_state(tree
, state
, prealloc
, end
+ 1);
685 extent_io_tree_panic(tree
, err
);
690 clear_state_bit(tree
, prealloc
, &bits
, wake
);
696 state
= clear_state_bit(tree
, state
, &bits
, wake
);
698 if (last_end
== (u64
)-1)
700 start
= last_end
+ 1;
701 if (start
<= end
&& state
&& !need_resched())
706 spin_unlock(&tree
->lock
);
708 free_extent_state(prealloc
);
715 spin_unlock(&tree
->lock
);
716 if (mask
& __GFP_WAIT
)
721 static void wait_on_state(struct extent_io_tree
*tree
,
722 struct extent_state
*state
)
723 __releases(tree
->lock
)
724 __acquires(tree
->lock
)
727 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
728 spin_unlock(&tree
->lock
);
730 spin_lock(&tree
->lock
);
731 finish_wait(&state
->wq
, &wait
);
735 * waits for one or more bits to clear on a range in the state tree.
736 * The range [start, end] is inclusive.
737 * The tree lock is taken by this function
739 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
742 struct extent_state
*state
;
743 struct rb_node
*node
;
745 btrfs_debug_check_extent_io_range(tree
, start
, end
);
747 spin_lock(&tree
->lock
);
751 * this search will find all the extents that end after
754 node
= tree_search(tree
, start
);
759 state
= rb_entry(node
, struct extent_state
, rb_node
);
761 if (state
->start
> end
)
764 if (state
->state
& bits
) {
765 start
= state
->start
;
766 atomic_inc(&state
->refs
);
767 wait_on_state(tree
, state
);
768 free_extent_state(state
);
771 start
= state
->end
+ 1;
776 if (!cond_resched_lock(&tree
->lock
)) {
777 node
= rb_next(node
);
782 spin_unlock(&tree
->lock
);
785 static void set_state_bits(struct extent_io_tree
*tree
,
786 struct extent_state
*state
,
789 unsigned long bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
791 set_state_cb(tree
, state
, bits
);
792 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
793 u64 range
= state
->end
- state
->start
+ 1;
794 tree
->dirty_bytes
+= range
;
796 state
->state
|= bits_to_set
;
799 static void cache_state(struct extent_state
*state
,
800 struct extent_state
**cached_ptr
)
802 if (cached_ptr
&& !(*cached_ptr
)) {
803 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
)) {
805 atomic_inc(&state
->refs
);
811 * set some bits on a range in the tree. This may require allocations or
812 * sleeping, so the gfp mask is used to indicate what is allowed.
814 * If any of the exclusive bits are set, this will fail with -EEXIST if some
815 * part of the range already has the desired bits set. The start of the
816 * existing range is returned in failed_start in this case.
818 * [start, end] is inclusive This takes the tree lock.
821 static int __must_check
822 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
823 unsigned long bits
, unsigned long exclusive_bits
,
824 u64
*failed_start
, struct extent_state
**cached_state
,
827 struct extent_state
*state
;
828 struct extent_state
*prealloc
= NULL
;
829 struct rb_node
*node
;
831 struct rb_node
*parent
;
836 btrfs_debug_check_extent_io_range(tree
, start
, end
);
838 bits
|= EXTENT_FIRST_DELALLOC
;
840 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
841 prealloc
= alloc_extent_state(mask
);
845 spin_lock(&tree
->lock
);
846 if (cached_state
&& *cached_state
) {
847 state
= *cached_state
;
848 if (state
->start
<= start
&& state
->end
> start
&&
849 extent_state_in_tree(state
)) {
850 node
= &state
->rb_node
;
855 * this search will find all the extents that end after
858 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
860 prealloc
= alloc_extent_state_atomic(prealloc
);
862 err
= insert_state(tree
, prealloc
, start
, end
,
865 extent_io_tree_panic(tree
, err
);
867 cache_state(prealloc
, cached_state
);
871 state
= rb_entry(node
, struct extent_state
, rb_node
);
873 last_start
= state
->start
;
874 last_end
= state
->end
;
877 * | ---- desired range ---- |
880 * Just lock what we found and keep going
882 if (state
->start
== start
&& state
->end
<= end
) {
883 if (state
->state
& exclusive_bits
) {
884 *failed_start
= state
->start
;
889 set_state_bits(tree
, state
, &bits
);
890 cache_state(state
, cached_state
);
891 merge_state(tree
, state
);
892 if (last_end
== (u64
)-1)
894 start
= last_end
+ 1;
895 state
= next_state(state
);
896 if (start
< end
&& state
&& state
->start
== start
&&
903 * | ---- desired range ---- |
906 * | ------------- state -------------- |
908 * We need to split the extent we found, and may flip bits on
911 * If the extent we found extends past our
912 * range, we just split and search again. It'll get split
913 * again the next time though.
915 * If the extent we found is inside our range, we set the
918 if (state
->start
< start
) {
919 if (state
->state
& exclusive_bits
) {
920 *failed_start
= start
;
925 prealloc
= alloc_extent_state_atomic(prealloc
);
927 err
= split_state(tree
, state
, prealloc
, start
);
929 extent_io_tree_panic(tree
, err
);
934 if (state
->end
<= end
) {
935 set_state_bits(tree
, state
, &bits
);
936 cache_state(state
, cached_state
);
937 merge_state(tree
, state
);
938 if (last_end
== (u64
)-1)
940 start
= last_end
+ 1;
941 state
= next_state(state
);
942 if (start
< end
&& state
&& state
->start
== start
&&
949 * | ---- desired range ---- |
950 * | state | or | state |
952 * There's a hole, we need to insert something in it and
953 * ignore the extent we found.
955 if (state
->start
> start
) {
957 if (end
< last_start
)
960 this_end
= last_start
- 1;
962 prealloc
= alloc_extent_state_atomic(prealloc
);
966 * Avoid to free 'prealloc' if it can be merged with
969 err
= insert_state(tree
, prealloc
, start
, this_end
,
972 extent_io_tree_panic(tree
, err
);
974 cache_state(prealloc
, cached_state
);
976 start
= this_end
+ 1;
980 * | ---- desired range ---- |
982 * We need to split the extent, and set the bit
985 if (state
->start
<= end
&& state
->end
> end
) {
986 if (state
->state
& exclusive_bits
) {
987 *failed_start
= start
;
992 prealloc
= alloc_extent_state_atomic(prealloc
);
994 err
= split_state(tree
, state
, prealloc
, end
+ 1);
996 extent_io_tree_panic(tree
, err
);
998 set_state_bits(tree
, prealloc
, &bits
);
999 cache_state(prealloc
, cached_state
);
1000 merge_state(tree
, prealloc
);
1008 spin_unlock(&tree
->lock
);
1010 free_extent_state(prealloc
);
1017 spin_unlock(&tree
->lock
);
1018 if (mask
& __GFP_WAIT
)
1023 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1024 unsigned long bits
, u64
* failed_start
,
1025 struct extent_state
**cached_state
, gfp_t mask
)
1027 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
1028 cached_state
, mask
);
1033 * convert_extent_bit - convert all bits in a given range from one bit to
1035 * @tree: the io tree to search
1036 * @start: the start offset in bytes
1037 * @end: the end offset in bytes (inclusive)
1038 * @bits: the bits to set in this range
1039 * @clear_bits: the bits to clear in this range
1040 * @cached_state: state that we're going to cache
1041 * @mask: the allocation mask
1043 * This will go through and set bits for the given range. If any states exist
1044 * already in this range they are set with the given bit and cleared of the
1045 * clear_bits. This is only meant to be used by things that are mergeable, ie
1046 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1047 * boundary bits like LOCK.
1049 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1050 unsigned long bits
, unsigned long clear_bits
,
1051 struct extent_state
**cached_state
, gfp_t mask
)
1053 struct extent_state
*state
;
1054 struct extent_state
*prealloc
= NULL
;
1055 struct rb_node
*node
;
1057 struct rb_node
*parent
;
1062 btrfs_debug_check_extent_io_range(tree
, start
, end
);
1065 if (!prealloc
&& (mask
& __GFP_WAIT
)) {
1066 prealloc
= alloc_extent_state(mask
);
1071 spin_lock(&tree
->lock
);
1072 if (cached_state
&& *cached_state
) {
1073 state
= *cached_state
;
1074 if (state
->start
<= start
&& state
->end
> start
&&
1075 extent_state_in_tree(state
)) {
1076 node
= &state
->rb_node
;
1082 * this search will find all the extents that end after
1085 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
1087 prealloc
= alloc_extent_state_atomic(prealloc
);
1092 err
= insert_state(tree
, prealloc
, start
, end
,
1093 &p
, &parent
, &bits
);
1095 extent_io_tree_panic(tree
, err
);
1096 cache_state(prealloc
, cached_state
);
1100 state
= rb_entry(node
, struct extent_state
, rb_node
);
1102 last_start
= state
->start
;
1103 last_end
= state
->end
;
1106 * | ---- desired range ---- |
1109 * Just lock what we found and keep going
1111 if (state
->start
== start
&& state
->end
<= end
) {
1112 set_state_bits(tree
, state
, &bits
);
1113 cache_state(state
, cached_state
);
1114 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1115 if (last_end
== (u64
)-1)
1117 start
= last_end
+ 1;
1118 if (start
< end
&& state
&& state
->start
== start
&&
1125 * | ---- desired range ---- |
1128 * | ------------- state -------------- |
1130 * We need to split the extent we found, and may flip bits on
1133 * If the extent we found extends past our
1134 * range, we just split and search again. It'll get split
1135 * again the next time though.
1137 * If the extent we found is inside our range, we set the
1138 * desired bit on it.
1140 if (state
->start
< start
) {
1141 prealloc
= alloc_extent_state_atomic(prealloc
);
1146 err
= split_state(tree
, state
, prealloc
, start
);
1148 extent_io_tree_panic(tree
, err
);
1152 if (state
->end
<= end
) {
1153 set_state_bits(tree
, state
, &bits
);
1154 cache_state(state
, cached_state
);
1155 state
= clear_state_bit(tree
, state
, &clear_bits
, 0);
1156 if (last_end
== (u64
)-1)
1158 start
= last_end
+ 1;
1159 if (start
< end
&& state
&& state
->start
== start
&&
1166 * | ---- desired range ---- |
1167 * | state | or | state |
1169 * There's a hole, we need to insert something in it and
1170 * ignore the extent we found.
1172 if (state
->start
> start
) {
1174 if (end
< last_start
)
1177 this_end
= last_start
- 1;
1179 prealloc
= alloc_extent_state_atomic(prealloc
);
1186 * Avoid to free 'prealloc' if it can be merged with
1189 err
= insert_state(tree
, prealloc
, start
, this_end
,
1192 extent_io_tree_panic(tree
, err
);
1193 cache_state(prealloc
, cached_state
);
1195 start
= this_end
+ 1;
1199 * | ---- desired range ---- |
1201 * We need to split the extent, and set the bit
1204 if (state
->start
<= end
&& state
->end
> end
) {
1205 prealloc
= alloc_extent_state_atomic(prealloc
);
1211 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1213 extent_io_tree_panic(tree
, err
);
1215 set_state_bits(tree
, prealloc
, &bits
);
1216 cache_state(prealloc
, cached_state
);
1217 clear_state_bit(tree
, prealloc
, &clear_bits
, 0);
1225 spin_unlock(&tree
->lock
);
1227 free_extent_state(prealloc
);
1234 spin_unlock(&tree
->lock
);
1235 if (mask
& __GFP_WAIT
)
1240 /* wrappers around set/clear extent bit */
1241 int set_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1244 return set_extent_bit(tree
, start
, end
, EXTENT_DIRTY
, NULL
,
1248 int set_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1249 unsigned long bits
, gfp_t mask
)
1251 return set_extent_bit(tree
, start
, end
, bits
, NULL
,
1255 int clear_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1256 unsigned long bits
, gfp_t mask
)
1258 return clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, mask
);
1261 int set_extent_delalloc(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1262 struct extent_state
**cached_state
, gfp_t mask
)
1264 return set_extent_bit(tree
, start
, end
,
1265 EXTENT_DELALLOC
| EXTENT_UPTODATE
,
1266 NULL
, cached_state
, mask
);
1269 int set_extent_defrag(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1270 struct extent_state
**cached_state
, gfp_t mask
)
1272 return set_extent_bit(tree
, start
, end
,
1273 EXTENT_DELALLOC
| EXTENT_UPTODATE
| EXTENT_DEFRAG
,
1274 NULL
, cached_state
, mask
);
1277 int clear_extent_dirty(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1280 return clear_extent_bit(tree
, start
, end
,
1281 EXTENT_DIRTY
| EXTENT_DELALLOC
|
1282 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
, mask
);
1285 int set_extent_new(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1288 return set_extent_bit(tree
, start
, end
, EXTENT_NEW
, NULL
,
1292 int set_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1293 struct extent_state
**cached_state
, gfp_t mask
)
1295 return set_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, NULL
,
1296 cached_state
, mask
);
1299 int clear_extent_uptodate(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1300 struct extent_state
**cached_state
, gfp_t mask
)
1302 return clear_extent_bit(tree
, start
, end
, EXTENT_UPTODATE
, 0, 0,
1303 cached_state
, mask
);
1307 * either insert or lock state struct between start and end use mask to tell
1308 * us if waiting is desired.
1310 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1311 unsigned long bits
, struct extent_state
**cached_state
)
1316 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
| bits
,
1317 EXTENT_LOCKED
, &failed_start
,
1318 cached_state
, GFP_NOFS
);
1319 if (err
== -EEXIST
) {
1320 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1321 start
= failed_start
;
1324 WARN_ON(start
> end
);
1329 int lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1331 return lock_extent_bits(tree
, start
, end
, 0, NULL
);
1334 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1339 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1340 &failed_start
, NULL
, GFP_NOFS
);
1341 if (err
== -EEXIST
) {
1342 if (failed_start
> start
)
1343 clear_extent_bit(tree
, start
, failed_start
- 1,
1344 EXTENT_LOCKED
, 1, 0, NULL
, GFP_NOFS
);
1350 int unlock_extent_cached(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1351 struct extent_state
**cached
, gfp_t mask
)
1353 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, cached
,
1357 int unlock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1359 return clear_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, 1, 0, NULL
,
1363 int extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1365 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1366 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1369 while (index
<= end_index
) {
1370 page
= find_get_page(inode
->i_mapping
, index
);
1371 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1372 clear_page_dirty_for_io(page
);
1373 page_cache_release(page
);
1379 int extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1381 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1382 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1385 while (index
<= end_index
) {
1386 page
= find_get_page(inode
->i_mapping
, index
);
1387 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1388 account_page_redirty(page
);
1389 __set_page_dirty_nobuffers(page
);
1390 page_cache_release(page
);
1397 * helper function to set both pages and extents in the tree writeback
1399 static int set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1401 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1402 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1405 while (index
<= end_index
) {
1406 page
= find_get_page(tree
->mapping
, index
);
1407 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1408 set_page_writeback(page
);
1409 page_cache_release(page
);
1415 /* find the first state struct with 'bits' set after 'start', and
1416 * return it. tree->lock must be held. NULL will returned if
1417 * nothing was found after 'start'
1419 static struct extent_state
*
1420 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1421 u64 start
, unsigned long bits
)
1423 struct rb_node
*node
;
1424 struct extent_state
*state
;
1427 * this search will find all the extents that end after
1430 node
= tree_search(tree
, start
);
1435 state
= rb_entry(node
, struct extent_state
, rb_node
);
1436 if (state
->end
>= start
&& (state
->state
& bits
))
1439 node
= rb_next(node
);
1448 * find the first offset in the io tree with 'bits' set. zero is
1449 * returned if we find something, and *start_ret and *end_ret are
1450 * set to reflect the state struct that was found.
1452 * If nothing was found, 1 is returned. If found something, return 0.
1454 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1455 u64
*start_ret
, u64
*end_ret
, unsigned long bits
,
1456 struct extent_state
**cached_state
)
1458 struct extent_state
*state
;
1462 spin_lock(&tree
->lock
);
1463 if (cached_state
&& *cached_state
) {
1464 state
= *cached_state
;
1465 if (state
->end
== start
- 1 && extent_state_in_tree(state
)) {
1466 n
= rb_next(&state
->rb_node
);
1468 state
= rb_entry(n
, struct extent_state
,
1470 if (state
->state
& bits
)
1474 free_extent_state(*cached_state
);
1475 *cached_state
= NULL
;
1478 free_extent_state(*cached_state
);
1479 *cached_state
= NULL
;
1482 state
= find_first_extent_bit_state(tree
, start
, bits
);
1485 cache_state(state
, cached_state
);
1486 *start_ret
= state
->start
;
1487 *end_ret
= state
->end
;
1491 spin_unlock(&tree
->lock
);
1496 * find a contiguous range of bytes in the file marked as delalloc, not
1497 * more than 'max_bytes'. start and end are used to return the range,
1499 * 1 is returned if we find something, 0 if nothing was in the tree
1501 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1502 u64
*start
, u64
*end
, u64 max_bytes
,
1503 struct extent_state
**cached_state
)
1505 struct rb_node
*node
;
1506 struct extent_state
*state
;
1507 u64 cur_start
= *start
;
1509 u64 total_bytes
= 0;
1511 spin_lock(&tree
->lock
);
1514 * this search will find all the extents that end after
1517 node
= tree_search(tree
, cur_start
);
1525 state
= rb_entry(node
, struct extent_state
, rb_node
);
1526 if (found
&& (state
->start
!= cur_start
||
1527 (state
->state
& EXTENT_BOUNDARY
))) {
1530 if (!(state
->state
& EXTENT_DELALLOC
)) {
1536 *start
= state
->start
;
1537 *cached_state
= state
;
1538 atomic_inc(&state
->refs
);
1542 cur_start
= state
->end
+ 1;
1543 node
= rb_next(node
);
1544 total_bytes
+= state
->end
- state
->start
+ 1;
1545 if (total_bytes
>= max_bytes
)
1551 spin_unlock(&tree
->lock
);
1555 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1556 struct page
*locked_page
,
1560 struct page
*pages
[16];
1561 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1562 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1563 unsigned long nr_pages
= end_index
- index
+ 1;
1566 if (index
== locked_page
->index
&& end_index
== index
)
1569 while (nr_pages
> 0) {
1570 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1571 min_t(unsigned long, nr_pages
,
1572 ARRAY_SIZE(pages
)), pages
);
1573 for (i
= 0; i
< ret
; i
++) {
1574 if (pages
[i
] != locked_page
)
1575 unlock_page(pages
[i
]);
1576 page_cache_release(pages
[i
]);
1584 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1585 struct page
*locked_page
,
1589 unsigned long index
= delalloc_start
>> PAGE_CACHE_SHIFT
;
1590 unsigned long start_index
= index
;
1591 unsigned long end_index
= delalloc_end
>> PAGE_CACHE_SHIFT
;
1592 unsigned long pages_locked
= 0;
1593 struct page
*pages
[16];
1594 unsigned long nrpages
;
1598 /* the caller is responsible for locking the start index */
1599 if (index
== locked_page
->index
&& index
== end_index
)
1602 /* skip the page at the start index */
1603 nrpages
= end_index
- index
+ 1;
1604 while (nrpages
> 0) {
1605 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1606 min_t(unsigned long,
1607 nrpages
, ARRAY_SIZE(pages
)), pages
);
1612 /* now we have an array of pages, lock them all */
1613 for (i
= 0; i
< ret
; i
++) {
1615 * the caller is taking responsibility for
1618 if (pages
[i
] != locked_page
) {
1619 lock_page(pages
[i
]);
1620 if (!PageDirty(pages
[i
]) ||
1621 pages
[i
]->mapping
!= inode
->i_mapping
) {
1623 unlock_page(pages
[i
]);
1624 page_cache_release(pages
[i
]);
1628 page_cache_release(pages
[i
]);
1637 if (ret
&& pages_locked
) {
1638 __unlock_for_delalloc(inode
, locked_page
,
1640 ((u64
)(start_index
+ pages_locked
- 1)) <<
1647 * find a contiguous range of bytes in the file marked as delalloc, not
1648 * more than 'max_bytes'. start and end are used to return the range,
1650 * 1 is returned if we find something, 0 if nothing was in the tree
1652 STATIC u64
find_lock_delalloc_range(struct inode
*inode
,
1653 struct extent_io_tree
*tree
,
1654 struct page
*locked_page
, u64
*start
,
1655 u64
*end
, u64 max_bytes
)
1660 struct extent_state
*cached_state
= NULL
;
1665 /* step one, find a bunch of delalloc bytes starting at start */
1666 delalloc_start
= *start
;
1668 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1669 max_bytes
, &cached_state
);
1670 if (!found
|| delalloc_end
<= *start
) {
1671 *start
= delalloc_start
;
1672 *end
= delalloc_end
;
1673 free_extent_state(cached_state
);
1678 * start comes from the offset of locked_page. We have to lock
1679 * pages in order, so we can't process delalloc bytes before
1682 if (delalloc_start
< *start
)
1683 delalloc_start
= *start
;
1686 * make sure to limit the number of pages we try to lock down
1688 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
)
1689 delalloc_end
= delalloc_start
+ max_bytes
- 1;
1691 /* step two, lock all the pages after the page that has start */
1692 ret
= lock_delalloc_pages(inode
, locked_page
,
1693 delalloc_start
, delalloc_end
);
1694 if (ret
== -EAGAIN
) {
1695 /* some of the pages are gone, lets avoid looping by
1696 * shortening the size of the delalloc range we're searching
1698 free_extent_state(cached_state
);
1699 cached_state
= NULL
;
1701 max_bytes
= PAGE_CACHE_SIZE
;
1709 BUG_ON(ret
); /* Only valid values are 0 and -EAGAIN */
1711 /* step three, lock the state bits for the whole range */
1712 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, 0, &cached_state
);
1714 /* then test to make sure it is all still delalloc */
1715 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1716 EXTENT_DELALLOC
, 1, cached_state
);
1718 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1719 &cached_state
, GFP_NOFS
);
1720 __unlock_for_delalloc(inode
, locked_page
,
1721 delalloc_start
, delalloc_end
);
1725 free_extent_state(cached_state
);
1726 *start
= delalloc_start
;
1727 *end
= delalloc_end
;
1732 int extent_clear_unlock_delalloc(struct inode
*inode
, u64 start
, u64 end
,
1733 struct page
*locked_page
,
1734 unsigned long clear_bits
,
1735 unsigned long page_ops
)
1737 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
1739 struct page
*pages
[16];
1740 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
1741 unsigned long end_index
= end
>> PAGE_CACHE_SHIFT
;
1742 unsigned long nr_pages
= end_index
- index
+ 1;
1745 clear_extent_bit(tree
, start
, end
, clear_bits
, 1, 0, NULL
, GFP_NOFS
);
1749 while (nr_pages
> 0) {
1750 ret
= find_get_pages_contig(inode
->i_mapping
, index
,
1751 min_t(unsigned long,
1752 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1753 for (i
= 0; i
< ret
; i
++) {
1755 if (page_ops
& PAGE_SET_PRIVATE2
)
1756 SetPagePrivate2(pages
[i
]);
1758 if (pages
[i
] == locked_page
) {
1759 page_cache_release(pages
[i
]);
1762 if (page_ops
& PAGE_CLEAR_DIRTY
)
1763 clear_page_dirty_for_io(pages
[i
]);
1764 if (page_ops
& PAGE_SET_WRITEBACK
)
1765 set_page_writeback(pages
[i
]);
1766 if (page_ops
& PAGE_END_WRITEBACK
)
1767 end_page_writeback(pages
[i
]);
1768 if (page_ops
& PAGE_UNLOCK
)
1769 unlock_page(pages
[i
]);
1770 page_cache_release(pages
[i
]);
1780 * count the number of bytes in the tree that have a given bit(s)
1781 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1782 * cached. The total number found is returned.
1784 u64
count_range_bits(struct extent_io_tree
*tree
,
1785 u64
*start
, u64 search_end
, u64 max_bytes
,
1786 unsigned long bits
, int contig
)
1788 struct rb_node
*node
;
1789 struct extent_state
*state
;
1790 u64 cur_start
= *start
;
1791 u64 total_bytes
= 0;
1795 if (WARN_ON(search_end
<= cur_start
))
1798 spin_lock(&tree
->lock
);
1799 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1800 total_bytes
= tree
->dirty_bytes
;
1804 * this search will find all the extents that end after
1807 node
= tree_search(tree
, cur_start
);
1812 state
= rb_entry(node
, struct extent_state
, rb_node
);
1813 if (state
->start
> search_end
)
1815 if (contig
&& found
&& state
->start
> last
+ 1)
1817 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1818 total_bytes
+= min(search_end
, state
->end
) + 1 -
1819 max(cur_start
, state
->start
);
1820 if (total_bytes
>= max_bytes
)
1823 *start
= max(cur_start
, state
->start
);
1827 } else if (contig
&& found
) {
1830 node
= rb_next(node
);
1835 spin_unlock(&tree
->lock
);
1840 * set the private field for a given byte offset in the tree. If there isn't
1841 * an extent_state there already, this does nothing.
1843 static int set_state_private(struct extent_io_tree
*tree
, u64 start
, u64
private)
1845 struct rb_node
*node
;
1846 struct extent_state
*state
;
1849 spin_lock(&tree
->lock
);
1851 * this search will find all the extents that end after
1854 node
= tree_search(tree
, start
);
1859 state
= rb_entry(node
, struct extent_state
, rb_node
);
1860 if (state
->start
!= start
) {
1864 state
->private = private;
1866 spin_unlock(&tree
->lock
);
1870 int get_state_private(struct extent_io_tree
*tree
, u64 start
, u64
*private)
1872 struct rb_node
*node
;
1873 struct extent_state
*state
;
1876 spin_lock(&tree
->lock
);
1878 * this search will find all the extents that end after
1881 node
= tree_search(tree
, start
);
1886 state
= rb_entry(node
, struct extent_state
, rb_node
);
1887 if (state
->start
!= start
) {
1891 *private = state
->private;
1893 spin_unlock(&tree
->lock
);
1898 * searches a range in the state tree for a given mask.
1899 * If 'filled' == 1, this returns 1 only if every extent in the tree
1900 * has the bits set. Otherwise, 1 is returned if any bit in the
1901 * range is found set.
1903 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1904 unsigned long bits
, int filled
, struct extent_state
*cached
)
1906 struct extent_state
*state
= NULL
;
1907 struct rb_node
*node
;
1910 spin_lock(&tree
->lock
);
1911 if (cached
&& extent_state_in_tree(cached
) && cached
->start
<= start
&&
1912 cached
->end
> start
)
1913 node
= &cached
->rb_node
;
1915 node
= tree_search(tree
, start
);
1916 while (node
&& start
<= end
) {
1917 state
= rb_entry(node
, struct extent_state
, rb_node
);
1919 if (filled
&& state
->start
> start
) {
1924 if (state
->start
> end
)
1927 if (state
->state
& bits
) {
1931 } else if (filled
) {
1936 if (state
->end
== (u64
)-1)
1939 start
= state
->end
+ 1;
1942 node
= rb_next(node
);
1949 spin_unlock(&tree
->lock
);
1954 * helper function to set a given page up to date if all the
1955 * extents in the tree for that page are up to date
1957 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
1959 u64 start
= page_offset(page
);
1960 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
1961 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1962 SetPageUptodate(page
);
1965 int free_io_failure(struct inode
*inode
, struct io_failure_record
*rec
)
1969 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
1971 set_state_private(failure_tree
, rec
->start
, 0);
1972 ret
= clear_extent_bits(failure_tree
, rec
->start
,
1973 rec
->start
+ rec
->len
- 1,
1974 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
1978 ret
= clear_extent_bits(&BTRFS_I(inode
)->io_tree
, rec
->start
,
1979 rec
->start
+ rec
->len
- 1,
1980 EXTENT_DAMAGED
, GFP_NOFS
);
1989 * this bypasses the standard btrfs submit functions deliberately, as
1990 * the standard behavior is to write all copies in a raid setup. here we only
1991 * want to write the one bad copy. so we do the mapping for ourselves and issue
1992 * submit_bio directly.
1993 * to avoid any synchronization issues, wait for the data after writing, which
1994 * actually prevents the read that triggered the error from finishing.
1995 * currently, there can be no more than two copies of every data bit. thus,
1996 * exactly one rewrite is required.
1998 int repair_io_failure(struct inode
*inode
, u64 start
, u64 length
, u64 logical
,
1999 struct page
*page
, unsigned int pg_offset
, int mirror_num
)
2001 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2003 struct btrfs_device
*dev
;
2006 struct btrfs_bio
*bbio
= NULL
;
2007 struct btrfs_mapping_tree
*map_tree
= &fs_info
->mapping_tree
;
2010 ASSERT(!(fs_info
->sb
->s_flags
& MS_RDONLY
));
2011 BUG_ON(!mirror_num
);
2013 /* we can't repair anything in raid56 yet */
2014 if (btrfs_is_parity_mirror(map_tree
, logical
, length
, mirror_num
))
2017 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2020 bio
->bi_iter
.bi_size
= 0;
2021 map_length
= length
;
2023 ret
= btrfs_map_block(fs_info
, WRITE
, logical
,
2024 &map_length
, &bbio
, mirror_num
);
2029 BUG_ON(mirror_num
!= bbio
->mirror_num
);
2030 sector
= bbio
->stripes
[mirror_num
-1].physical
>> 9;
2031 bio
->bi_iter
.bi_sector
= sector
;
2032 dev
= bbio
->stripes
[mirror_num
-1].dev
;
2034 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2038 bio
->bi_bdev
= dev
->bdev
;
2039 bio_add_page(bio
, page
, length
, pg_offset
);
2041 if (btrfsic_submit_bio_wait(WRITE_SYNC
, bio
)) {
2042 /* try to remap that extent elsewhere? */
2044 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2048 printk_ratelimited_in_rcu(KERN_INFO
2049 "BTRFS: read error corrected: ino %llu off %llu (dev %s sector %llu)\n",
2050 btrfs_ino(inode
), start
,
2051 rcu_str_deref(dev
->name
), sector
);
2056 int repair_eb_io_failure(struct btrfs_root
*root
, struct extent_buffer
*eb
,
2059 u64 start
= eb
->start
;
2060 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2063 if (root
->fs_info
->sb
->s_flags
& MS_RDONLY
)
2066 for (i
= 0; i
< num_pages
; i
++) {
2067 struct page
*p
= eb
->pages
[i
];
2069 ret
= repair_io_failure(root
->fs_info
->btree_inode
, start
,
2070 PAGE_CACHE_SIZE
, start
, p
,
2071 start
- page_offset(p
), mirror_num
);
2074 start
+= PAGE_CACHE_SIZE
;
2081 * each time an IO finishes, we do a fast check in the IO failure tree
2082 * to see if we need to process or clean up an io_failure_record
2084 int clean_io_failure(struct inode
*inode
, u64 start
, struct page
*page
,
2085 unsigned int pg_offset
)
2088 u64 private_failure
;
2089 struct io_failure_record
*failrec
;
2090 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2091 struct extent_state
*state
;
2096 ret
= count_range_bits(&BTRFS_I(inode
)->io_failure_tree
, &private,
2097 (u64
)-1, 1, EXTENT_DIRTY
, 0);
2101 ret
= get_state_private(&BTRFS_I(inode
)->io_failure_tree
, start
,
2106 failrec
= (struct io_failure_record
*)(unsigned long) private_failure
;
2107 BUG_ON(!failrec
->this_mirror
);
2109 if (failrec
->in_validation
) {
2110 /* there was no real error, just free the record */
2111 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2115 if (fs_info
->sb
->s_flags
& MS_RDONLY
)
2118 spin_lock(&BTRFS_I(inode
)->io_tree
.lock
);
2119 state
= find_first_extent_bit_state(&BTRFS_I(inode
)->io_tree
,
2122 spin_unlock(&BTRFS_I(inode
)->io_tree
.lock
);
2124 if (state
&& state
->start
<= failrec
->start
&&
2125 state
->end
>= failrec
->start
+ failrec
->len
- 1) {
2126 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2128 if (num_copies
> 1) {
2129 repair_io_failure(inode
, start
, failrec
->len
,
2130 failrec
->logical
, page
,
2131 pg_offset
, failrec
->failed_mirror
);
2136 free_io_failure(inode
, failrec
);
2142 * Can be called when
2143 * - hold extent lock
2144 * - under ordered extent
2145 * - the inode is freeing
2147 void btrfs_free_io_failure_record(struct inode
*inode
, u64 start
, u64 end
)
2149 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2150 struct io_failure_record
*failrec
;
2151 struct extent_state
*state
, *next
;
2153 if (RB_EMPTY_ROOT(&failure_tree
->state
))
2156 spin_lock(&failure_tree
->lock
);
2157 state
= find_first_extent_bit_state(failure_tree
, start
, EXTENT_DIRTY
);
2159 if (state
->start
> end
)
2162 ASSERT(state
->end
<= end
);
2164 next
= next_state(state
);
2166 failrec
= (struct io_failure_record
*)state
->private;
2167 free_extent_state(state
);
2172 spin_unlock(&failure_tree
->lock
);
2175 int btrfs_get_io_failure_record(struct inode
*inode
, u64 start
, u64 end
,
2176 struct io_failure_record
**failrec_ret
)
2178 struct io_failure_record
*failrec
;
2180 struct extent_map
*em
;
2181 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2182 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2183 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2187 ret
= get_state_private(failure_tree
, start
, &private);
2189 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2193 failrec
->start
= start
;
2194 failrec
->len
= end
- start
+ 1;
2195 failrec
->this_mirror
= 0;
2196 failrec
->bio_flags
= 0;
2197 failrec
->in_validation
= 0;
2199 read_lock(&em_tree
->lock
);
2200 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2202 read_unlock(&em_tree
->lock
);
2207 if (em
->start
> start
|| em
->start
+ em
->len
<= start
) {
2208 free_extent_map(em
);
2211 read_unlock(&em_tree
->lock
);
2217 logical
= start
- em
->start
;
2218 logical
= em
->block_start
+ logical
;
2219 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2220 logical
= em
->block_start
;
2221 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2222 extent_set_compress_type(&failrec
->bio_flags
,
2226 pr_debug("Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu\n",
2227 logical
, start
, failrec
->len
);
2229 failrec
->logical
= logical
;
2230 free_extent_map(em
);
2232 /* set the bits in the private failure tree */
2233 ret
= set_extent_bits(failure_tree
, start
, end
,
2234 EXTENT_LOCKED
| EXTENT_DIRTY
, GFP_NOFS
);
2236 ret
= set_state_private(failure_tree
, start
,
2237 (u64
)(unsigned long)failrec
);
2238 /* set the bits in the inode's tree */
2240 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
,
2247 failrec
= (struct io_failure_record
*)(unsigned long)private;
2248 pr_debug("Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d\n",
2249 failrec
->logical
, failrec
->start
, failrec
->len
,
2250 failrec
->in_validation
);
2252 * when data can be on disk more than twice, add to failrec here
2253 * (e.g. with a list for failed_mirror) to make
2254 * clean_io_failure() clean all those errors at once.
2258 *failrec_ret
= failrec
;
2263 int btrfs_check_repairable(struct inode
*inode
, struct bio
*failed_bio
,
2264 struct io_failure_record
*failrec
, int failed_mirror
)
2268 num_copies
= btrfs_num_copies(BTRFS_I(inode
)->root
->fs_info
,
2269 failrec
->logical
, failrec
->len
);
2270 if (num_copies
== 1) {
2272 * we only have a single copy of the data, so don't bother with
2273 * all the retry and error correction code that follows. no
2274 * matter what the error is, it is very likely to persist.
2276 pr_debug("Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
2277 num_copies
, failrec
->this_mirror
, failed_mirror
);
2282 * there are two premises:
2283 * a) deliver good data to the caller
2284 * b) correct the bad sectors on disk
2286 if (failed_bio
->bi_vcnt
> 1) {
2288 * to fulfill b), we need to know the exact failing sectors, as
2289 * we don't want to rewrite any more than the failed ones. thus,
2290 * we need separate read requests for the failed bio
2292 * if the following BUG_ON triggers, our validation request got
2293 * merged. we need separate requests for our algorithm to work.
2295 BUG_ON(failrec
->in_validation
);
2296 failrec
->in_validation
= 1;
2297 failrec
->this_mirror
= failed_mirror
;
2300 * we're ready to fulfill a) and b) alongside. get a good copy
2301 * of the failed sector and if we succeed, we have setup
2302 * everything for repair_io_failure to do the rest for us.
2304 if (failrec
->in_validation
) {
2305 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2306 failrec
->in_validation
= 0;
2307 failrec
->this_mirror
= 0;
2309 failrec
->failed_mirror
= failed_mirror
;
2310 failrec
->this_mirror
++;
2311 if (failrec
->this_mirror
== failed_mirror
)
2312 failrec
->this_mirror
++;
2315 if (failrec
->this_mirror
> num_copies
) {
2316 pr_debug("Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
2317 num_copies
, failrec
->this_mirror
, failed_mirror
);
2325 struct bio
*btrfs_create_repair_bio(struct inode
*inode
, struct bio
*failed_bio
,
2326 struct io_failure_record
*failrec
,
2327 struct page
*page
, int pg_offset
, int icsum
,
2328 bio_end_io_t
*endio_func
, void *data
)
2331 struct btrfs_io_bio
*btrfs_failed_bio
;
2332 struct btrfs_io_bio
*btrfs_bio
;
2334 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2338 bio
->bi_end_io
= endio_func
;
2339 bio
->bi_iter
.bi_sector
= failrec
->logical
>> 9;
2340 bio
->bi_bdev
= BTRFS_I(inode
)->root
->fs_info
->fs_devices
->latest_bdev
;
2341 bio
->bi_iter
.bi_size
= 0;
2342 bio
->bi_private
= data
;
2344 btrfs_failed_bio
= btrfs_io_bio(failed_bio
);
2345 if (btrfs_failed_bio
->csum
) {
2346 struct btrfs_fs_info
*fs_info
= BTRFS_I(inode
)->root
->fs_info
;
2347 u16 csum_size
= btrfs_super_csum_size(fs_info
->super_copy
);
2349 btrfs_bio
= btrfs_io_bio(bio
);
2350 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
2352 memcpy(btrfs_bio
->csum
, btrfs_failed_bio
->csum
+ icsum
,
2356 bio_add_page(bio
, page
, failrec
->len
, pg_offset
);
2362 * this is a generic handler for readpage errors (default
2363 * readpage_io_failed_hook). if other copies exist, read those and write back
2364 * good data to the failed position. does not investigate in remapping the
2365 * failed extent elsewhere, hoping the device will be smart enough to do this as
2369 static int bio_readpage_error(struct bio
*failed_bio
, u64 phy_offset
,
2370 struct page
*page
, u64 start
, u64 end
,
2373 struct io_failure_record
*failrec
;
2374 struct inode
*inode
= page
->mapping
->host
;
2375 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2380 BUG_ON(failed_bio
->bi_rw
& REQ_WRITE
);
2382 ret
= btrfs_get_io_failure_record(inode
, start
, end
, &failrec
);
2386 ret
= btrfs_check_repairable(inode
, failed_bio
, failrec
, failed_mirror
);
2388 free_io_failure(inode
, failrec
);
2392 if (failed_bio
->bi_vcnt
> 1)
2393 read_mode
= READ_SYNC
| REQ_FAILFAST_DEV
;
2395 read_mode
= READ_SYNC
;
2397 phy_offset
>>= inode
->i_sb
->s_blocksize_bits
;
2398 bio
= btrfs_create_repair_bio(inode
, failed_bio
, failrec
, page
,
2399 start
- page_offset(page
),
2400 (int)phy_offset
, failed_bio
->bi_end_io
,
2403 free_io_failure(inode
, failrec
);
2407 pr_debug("Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d\n",
2408 read_mode
, failrec
->this_mirror
, failrec
->in_validation
);
2410 ret
= tree
->ops
->submit_bio_hook(inode
, read_mode
, bio
,
2411 failrec
->this_mirror
,
2412 failrec
->bio_flags
, 0);
2414 free_io_failure(inode
, failrec
);
2421 /* lots and lots of room for performance fixes in the end_bio funcs */
2423 int end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2425 int uptodate
= (err
== 0);
2426 struct extent_io_tree
*tree
;
2429 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2431 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
) {
2432 ret
= tree
->ops
->writepage_end_io_hook(page
, start
,
2433 end
, NULL
, uptodate
);
2439 ClearPageUptodate(page
);
2441 ret
= ret
< 0 ? ret
: -EIO
;
2442 mapping_set_error(page
->mapping
, ret
);
2448 * after a writepage IO is done, we need to:
2449 * clear the uptodate bits on error
2450 * clear the writeback bits in the extent tree for this IO
2451 * end_page_writeback if the page has no more pending IO
2453 * Scheduling is not allowed, so the extent state tree is expected
2454 * to have one and only one object corresponding to this IO.
2456 static void end_bio_extent_writepage(struct bio
*bio
, int err
)
2458 struct bio_vec
*bvec
;
2463 bio_for_each_segment_all(bvec
, bio
, i
) {
2464 struct page
*page
= bvec
->bv_page
;
2466 /* We always issue full-page reads, but if some block
2467 * in a page fails to read, blk_update_request() will
2468 * advance bv_offset and adjust bv_len to compensate.
2469 * Print a warning for nonzero offsets, and an error
2470 * if they don't add up to a full page. */
2471 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
) {
2472 if (bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2473 btrfs_err(BTRFS_I(page
->mapping
->host
)->root
->fs_info
,
2474 "partial page write in btrfs with offset %u and length %u",
2475 bvec
->bv_offset
, bvec
->bv_len
);
2477 btrfs_info(BTRFS_I(page
->mapping
->host
)->root
->fs_info
,
2478 "incomplete page write in btrfs with offset %u and "
2480 bvec
->bv_offset
, bvec
->bv_len
);
2483 start
= page_offset(page
);
2484 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2486 if (end_extent_writepage(page
, err
, start
, end
))
2489 end_page_writeback(page
);
2496 endio_readpage_release_extent(struct extent_io_tree
*tree
, u64 start
, u64 len
,
2499 struct extent_state
*cached
= NULL
;
2500 u64 end
= start
+ len
- 1;
2502 if (uptodate
&& tree
->track_uptodate
)
2503 set_extent_uptodate(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2504 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2508 * after a readpage IO is done, we need to:
2509 * clear the uptodate bits on error
2510 * set the uptodate bits if things worked
2511 * set the page up to date if all extents in the tree are uptodate
2512 * clear the lock bit in the extent tree
2513 * unlock the page if there are no other extents locked for it
2515 * Scheduling is not allowed, so the extent state tree is expected
2516 * to have one and only one object corresponding to this IO.
2518 static void end_bio_extent_readpage(struct bio
*bio
, int err
)
2520 struct bio_vec
*bvec
;
2521 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2522 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2523 struct extent_io_tree
*tree
;
2528 u64 extent_start
= 0;
2537 bio_for_each_segment_all(bvec
, bio
, i
) {
2538 struct page
*page
= bvec
->bv_page
;
2539 struct inode
*inode
= page
->mapping
->host
;
2541 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2542 "mirror=%u\n", (u64
)bio
->bi_iter
.bi_sector
, err
,
2543 io_bio
->mirror_num
);
2544 tree
= &BTRFS_I(inode
)->io_tree
;
2546 /* We always issue full-page reads, but if some block
2547 * in a page fails to read, blk_update_request() will
2548 * advance bv_offset and adjust bv_len to compensate.
2549 * Print a warning for nonzero offsets, and an error
2550 * if they don't add up to a full page. */
2551 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_CACHE_SIZE
) {
2552 if (bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_CACHE_SIZE
)
2553 btrfs_err(BTRFS_I(page
->mapping
->host
)->root
->fs_info
,
2554 "partial page read in btrfs with offset %u and length %u",
2555 bvec
->bv_offset
, bvec
->bv_len
);
2557 btrfs_info(BTRFS_I(page
->mapping
->host
)->root
->fs_info
,
2558 "incomplete page read in btrfs with offset %u and "
2560 bvec
->bv_offset
, bvec
->bv_len
);
2563 start
= page_offset(page
);
2564 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2567 mirror
= io_bio
->mirror_num
;
2568 if (likely(uptodate
&& tree
->ops
&&
2569 tree
->ops
->readpage_end_io_hook
)) {
2570 ret
= tree
->ops
->readpage_end_io_hook(io_bio
, offset
,
2576 clean_io_failure(inode
, start
, page
, 0);
2579 if (likely(uptodate
))
2582 if (tree
->ops
&& tree
->ops
->readpage_io_failed_hook
) {
2583 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2585 test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
2589 * The generic bio_readpage_error handles errors the
2590 * following way: If possible, new read requests are
2591 * created and submitted and will end up in
2592 * end_bio_extent_readpage as well (if we're lucky, not
2593 * in the !uptodate case). In that case it returns 0 and
2594 * we just go on with the next page in our bio. If it
2595 * can't handle the error it will return -EIO and we
2596 * remain responsible for that page.
2598 ret
= bio_readpage_error(bio
, offset
, page
, start
, end
,
2602 test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2610 if (likely(uptodate
)) {
2611 loff_t i_size
= i_size_read(inode
);
2612 pgoff_t end_index
= i_size
>> PAGE_CACHE_SHIFT
;
2615 /* Zero out the end if this page straddles i_size */
2616 off
= i_size
& (PAGE_CACHE_SIZE
-1);
2617 if (page
->index
== end_index
&& off
)
2618 zero_user_segment(page
, off
, PAGE_CACHE_SIZE
);
2619 SetPageUptodate(page
);
2621 ClearPageUptodate(page
);
2627 if (unlikely(!uptodate
)) {
2629 endio_readpage_release_extent(tree
,
2635 endio_readpage_release_extent(tree
, start
,
2636 end
- start
+ 1, 0);
2637 } else if (!extent_len
) {
2638 extent_start
= start
;
2639 extent_len
= end
+ 1 - start
;
2640 } else if (extent_start
+ extent_len
== start
) {
2641 extent_len
+= end
+ 1 - start
;
2643 endio_readpage_release_extent(tree
, extent_start
,
2644 extent_len
, uptodate
);
2645 extent_start
= start
;
2646 extent_len
= end
+ 1 - start
;
2651 endio_readpage_release_extent(tree
, extent_start
, extent_len
,
2654 io_bio
->end_io(io_bio
, err
);
2659 * this allocates from the btrfs_bioset. We're returning a bio right now
2660 * but you can call btrfs_io_bio for the appropriate container_of magic
2663 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
2666 struct btrfs_io_bio
*btrfs_bio
;
2669 bio
= bio_alloc_bioset(gfp_flags
, nr_vecs
, btrfs_bioset
);
2671 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
2672 while (!bio
&& (nr_vecs
/= 2)) {
2673 bio
= bio_alloc_bioset(gfp_flags
,
2674 nr_vecs
, btrfs_bioset
);
2679 bio
->bi_bdev
= bdev
;
2680 bio
->bi_iter
.bi_sector
= first_sector
;
2681 btrfs_bio
= btrfs_io_bio(bio
);
2682 btrfs_bio
->csum
= NULL
;
2683 btrfs_bio
->csum_allocated
= NULL
;
2684 btrfs_bio
->end_io
= NULL
;
2689 struct bio
*btrfs_bio_clone(struct bio
*bio
, gfp_t gfp_mask
)
2691 struct btrfs_io_bio
*btrfs_bio
;
2694 new = bio_clone_bioset(bio
, gfp_mask
, btrfs_bioset
);
2696 btrfs_bio
= btrfs_io_bio(new);
2697 btrfs_bio
->csum
= NULL
;
2698 btrfs_bio
->csum_allocated
= NULL
;
2699 btrfs_bio
->end_io
= NULL
;
2704 /* this also allocates from the btrfs_bioset */
2705 struct bio
*btrfs_io_bio_alloc(gfp_t gfp_mask
, unsigned int nr_iovecs
)
2707 struct btrfs_io_bio
*btrfs_bio
;
2710 bio
= bio_alloc_bioset(gfp_mask
, nr_iovecs
, btrfs_bioset
);
2712 btrfs_bio
= btrfs_io_bio(bio
);
2713 btrfs_bio
->csum
= NULL
;
2714 btrfs_bio
->csum_allocated
= NULL
;
2715 btrfs_bio
->end_io
= NULL
;
2721 static int __must_check
submit_one_bio(int rw
, struct bio
*bio
,
2722 int mirror_num
, unsigned long bio_flags
)
2725 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2726 struct page
*page
= bvec
->bv_page
;
2727 struct extent_io_tree
*tree
= bio
->bi_private
;
2730 start
= page_offset(page
) + bvec
->bv_offset
;
2732 bio
->bi_private
= NULL
;
2736 if (tree
->ops
&& tree
->ops
->submit_bio_hook
)
2737 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, rw
, bio
,
2738 mirror_num
, bio_flags
, start
);
2740 btrfsic_submit_bio(rw
, bio
);
2742 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
2748 static int merge_bio(int rw
, struct extent_io_tree
*tree
, struct page
*page
,
2749 unsigned long offset
, size_t size
, struct bio
*bio
,
2750 unsigned long bio_flags
)
2753 if (tree
->ops
&& tree
->ops
->merge_bio_hook
)
2754 ret
= tree
->ops
->merge_bio_hook(rw
, page
, offset
, size
, bio
,
2761 static int submit_extent_page(int rw
, struct extent_io_tree
*tree
,
2762 struct page
*page
, sector_t sector
,
2763 size_t size
, unsigned long offset
,
2764 struct block_device
*bdev
,
2765 struct bio
**bio_ret
,
2766 unsigned long max_pages
,
2767 bio_end_io_t end_io_func
,
2769 unsigned long prev_bio_flags
,
2770 unsigned long bio_flags
)
2776 int this_compressed
= bio_flags
& EXTENT_BIO_COMPRESSED
;
2777 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2778 size_t page_size
= min_t(size_t, size
, PAGE_CACHE_SIZE
);
2780 if (bio_ret
&& *bio_ret
) {
2783 contig
= bio
->bi_iter
.bi_sector
== sector
;
2785 contig
= bio_end_sector(bio
) == sector
;
2787 if (prev_bio_flags
!= bio_flags
|| !contig
||
2788 merge_bio(rw
, tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2789 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2790 ret
= submit_one_bio(rw
, bio
, mirror_num
,
2799 if (this_compressed
)
2802 nr
= bio_get_nr_vecs(bdev
);
2804 bio
= btrfs_bio_alloc(bdev
, sector
, nr
, GFP_NOFS
| __GFP_HIGH
);
2808 bio_add_page(bio
, page
, page_size
, offset
);
2809 bio
->bi_end_io
= end_io_func
;
2810 bio
->bi_private
= tree
;
2815 ret
= submit_one_bio(rw
, bio
, mirror_num
, bio_flags
);
2820 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2823 if (!PagePrivate(page
)) {
2824 SetPagePrivate(page
);
2825 page_cache_get(page
);
2826 set_page_private(page
, (unsigned long)eb
);
2828 WARN_ON(page
->private != (unsigned long)eb
);
2832 void set_page_extent_mapped(struct page
*page
)
2834 if (!PagePrivate(page
)) {
2835 SetPagePrivate(page
);
2836 page_cache_get(page
);
2837 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2841 static struct extent_map
*
2842 __get_extent_map(struct inode
*inode
, struct page
*page
, size_t pg_offset
,
2843 u64 start
, u64 len
, get_extent_t
*get_extent
,
2844 struct extent_map
**em_cached
)
2846 struct extent_map
*em
;
2848 if (em_cached
&& *em_cached
) {
2850 if (extent_map_in_tree(em
) && start
>= em
->start
&&
2851 start
< extent_map_end(em
)) {
2852 atomic_inc(&em
->refs
);
2856 free_extent_map(em
);
2860 em
= get_extent(inode
, page
, pg_offset
, start
, len
, 0);
2861 if (em_cached
&& !IS_ERR_OR_NULL(em
)) {
2863 atomic_inc(&em
->refs
);
2869 * basic readpage implementation. Locked extent state structs are inserted
2870 * into the tree that are removed when the IO is done (by the end_io
2872 * XXX JDM: This needs looking at to ensure proper page locking
2874 static int __do_readpage(struct extent_io_tree
*tree
,
2876 get_extent_t
*get_extent
,
2877 struct extent_map
**em_cached
,
2878 struct bio
**bio
, int mirror_num
,
2879 unsigned long *bio_flags
, int rw
)
2881 struct inode
*inode
= page
->mapping
->host
;
2882 u64 start
= page_offset(page
);
2883 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
2887 u64 last_byte
= i_size_read(inode
);
2891 struct extent_map
*em
;
2892 struct block_device
*bdev
;
2895 int parent_locked
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2896 size_t pg_offset
= 0;
2898 size_t disk_io_size
;
2899 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2900 unsigned long this_bio_flag
= *bio_flags
& EXTENT_BIO_PARENT_LOCKED
;
2902 set_page_extent_mapped(page
);
2905 if (!PageUptodate(page
)) {
2906 if (cleancache_get_page(page
) == 0) {
2907 BUG_ON(blocksize
!= PAGE_SIZE
);
2908 unlock_extent(tree
, start
, end
);
2913 if (page
->index
== last_byte
>> PAGE_CACHE_SHIFT
) {
2915 size_t zero_offset
= last_byte
& (PAGE_CACHE_SIZE
- 1);
2918 iosize
= PAGE_CACHE_SIZE
- zero_offset
;
2919 userpage
= kmap_atomic(page
);
2920 memset(userpage
+ zero_offset
, 0, iosize
);
2921 flush_dcache_page(page
);
2922 kunmap_atomic(userpage
);
2925 while (cur
<= end
) {
2926 unsigned long pnr
= (last_byte
>> PAGE_CACHE_SHIFT
) + 1;
2928 if (cur
>= last_byte
) {
2930 struct extent_state
*cached
= NULL
;
2932 iosize
= PAGE_CACHE_SIZE
- pg_offset
;
2933 userpage
= kmap_atomic(page
);
2934 memset(userpage
+ pg_offset
, 0, iosize
);
2935 flush_dcache_page(page
);
2936 kunmap_atomic(userpage
);
2937 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2940 unlock_extent_cached(tree
, cur
,
2945 em
= __get_extent_map(inode
, page
, pg_offset
, cur
,
2946 end
- cur
+ 1, get_extent
, em_cached
);
2947 if (IS_ERR_OR_NULL(em
)) {
2950 unlock_extent(tree
, cur
, end
);
2953 extent_offset
= cur
- em
->start
;
2954 BUG_ON(extent_map_end(em
) <= cur
);
2957 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2958 this_bio_flag
|= EXTENT_BIO_COMPRESSED
;
2959 extent_set_compress_type(&this_bio_flag
,
2963 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2964 cur_end
= min(extent_map_end(em
) - 1, end
);
2965 iosize
= ALIGN(iosize
, blocksize
);
2966 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2967 disk_io_size
= em
->block_len
;
2968 sector
= em
->block_start
>> 9;
2970 sector
= (em
->block_start
+ extent_offset
) >> 9;
2971 disk_io_size
= iosize
;
2974 block_start
= em
->block_start
;
2975 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2976 block_start
= EXTENT_MAP_HOLE
;
2977 free_extent_map(em
);
2980 /* we've found a hole, just zero and go on */
2981 if (block_start
== EXTENT_MAP_HOLE
) {
2983 struct extent_state
*cached
= NULL
;
2985 userpage
= kmap_atomic(page
);
2986 memset(userpage
+ pg_offset
, 0, iosize
);
2987 flush_dcache_page(page
);
2988 kunmap_atomic(userpage
);
2990 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2992 unlock_extent_cached(tree
, cur
, cur
+ iosize
- 1,
2995 pg_offset
+= iosize
;
2998 /* the get_extent function already copied into the page */
2999 if (test_range_bit(tree
, cur
, cur_end
,
3000 EXTENT_UPTODATE
, 1, NULL
)) {
3001 check_page_uptodate(tree
, page
);
3003 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3005 pg_offset
+= iosize
;
3008 /* we have an inline extent but it didn't get marked up
3009 * to date. Error out
3011 if (block_start
== EXTENT_MAP_INLINE
) {
3014 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3016 pg_offset
+= iosize
;
3021 ret
= submit_extent_page(rw
, tree
, page
,
3022 sector
, disk_io_size
, pg_offset
,
3024 end_bio_extent_readpage
, mirror_num
,
3029 *bio_flags
= this_bio_flag
;
3033 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3036 pg_offset
+= iosize
;
3040 if (!PageError(page
))
3041 SetPageUptodate(page
);
3047 static inline void __do_contiguous_readpages(struct extent_io_tree
*tree
,
3048 struct page
*pages
[], int nr_pages
,
3050 get_extent_t
*get_extent
,
3051 struct extent_map
**em_cached
,
3052 struct bio
**bio
, int mirror_num
,
3053 unsigned long *bio_flags
, int rw
)
3055 struct inode
*inode
;
3056 struct btrfs_ordered_extent
*ordered
;
3059 inode
= pages
[0]->mapping
->host
;
3061 lock_extent(tree
, start
, end
);
3062 ordered
= btrfs_lookup_ordered_range(inode
, start
,
3066 unlock_extent(tree
, start
, end
);
3067 btrfs_start_ordered_extent(inode
, ordered
, 1);
3068 btrfs_put_ordered_extent(ordered
);
3071 for (index
= 0; index
< nr_pages
; index
++) {
3072 __do_readpage(tree
, pages
[index
], get_extent
, em_cached
, bio
,
3073 mirror_num
, bio_flags
, rw
);
3074 page_cache_release(pages
[index
]);
3078 static void __extent_readpages(struct extent_io_tree
*tree
,
3079 struct page
*pages
[],
3080 int nr_pages
, get_extent_t
*get_extent
,
3081 struct extent_map
**em_cached
,
3082 struct bio
**bio
, int mirror_num
,
3083 unsigned long *bio_flags
, int rw
)
3089 int first_index
= 0;
3091 for (index
= 0; index
< nr_pages
; index
++) {
3092 page_start
= page_offset(pages
[index
]);
3095 end
= start
+ PAGE_CACHE_SIZE
- 1;
3096 first_index
= index
;
3097 } else if (end
+ 1 == page_start
) {
3098 end
+= PAGE_CACHE_SIZE
;
3100 __do_contiguous_readpages(tree
, &pages
[first_index
],
3101 index
- first_index
, start
,
3102 end
, get_extent
, em_cached
,
3103 bio
, mirror_num
, bio_flags
,
3106 end
= start
+ PAGE_CACHE_SIZE
- 1;
3107 first_index
= index
;
3112 __do_contiguous_readpages(tree
, &pages
[first_index
],
3113 index
- first_index
, start
,
3114 end
, get_extent
, em_cached
, bio
,
3115 mirror_num
, bio_flags
, rw
);
3118 static int __extent_read_full_page(struct extent_io_tree
*tree
,
3120 get_extent_t
*get_extent
,
3121 struct bio
**bio
, int mirror_num
,
3122 unsigned long *bio_flags
, int rw
)
3124 struct inode
*inode
= page
->mapping
->host
;
3125 struct btrfs_ordered_extent
*ordered
;
3126 u64 start
= page_offset(page
);
3127 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
3131 lock_extent(tree
, start
, end
);
3132 ordered
= btrfs_lookup_ordered_extent(inode
, start
);
3135 unlock_extent(tree
, start
, end
);
3136 btrfs_start_ordered_extent(inode
, ordered
, 1);
3137 btrfs_put_ordered_extent(ordered
);
3140 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, bio
, mirror_num
,
3145 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3146 get_extent_t
*get_extent
, int mirror_num
)
3148 struct bio
*bio
= NULL
;
3149 unsigned long bio_flags
= 0;
3152 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
3155 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3159 int extent_read_full_page_nolock(struct extent_io_tree
*tree
, struct page
*page
,
3160 get_extent_t
*get_extent
, int mirror_num
)
3162 struct bio
*bio
= NULL
;
3163 unsigned long bio_flags
= EXTENT_BIO_PARENT_LOCKED
;
3166 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, &bio
, mirror_num
,
3169 ret
= submit_one_bio(READ
, bio
, mirror_num
, bio_flags
);
3173 static noinline
void update_nr_written(struct page
*page
,
3174 struct writeback_control
*wbc
,
3175 unsigned long nr_written
)
3177 wbc
->nr_to_write
-= nr_written
;
3178 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 &&
3179 wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
))
3180 page
->mapping
->writeback_index
= page
->index
+ nr_written
;
3184 * helper for __extent_writepage, doing all of the delayed allocation setup.
3186 * This returns 1 if our fill_delalloc function did all the work required
3187 * to write the page (copy into inline extent). In this case the IO has
3188 * been started and the page is already unlocked.
3190 * This returns 0 if all went well (page still locked)
3191 * This returns < 0 if there were errors (page still locked)
3193 static noinline_for_stack
int writepage_delalloc(struct inode
*inode
,
3194 struct page
*page
, struct writeback_control
*wbc
,
3195 struct extent_page_data
*epd
,
3197 unsigned long *nr_written
)
3199 struct extent_io_tree
*tree
= epd
->tree
;
3200 u64 page_end
= delalloc_start
+ PAGE_CACHE_SIZE
- 1;
3202 u64 delalloc_to_write
= 0;
3203 u64 delalloc_end
= 0;
3205 int page_started
= 0;
3207 if (epd
->extent_locked
|| !tree
->ops
|| !tree
->ops
->fill_delalloc
)
3210 while (delalloc_end
< page_end
) {
3211 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
3216 if (nr_delalloc
== 0) {
3217 delalloc_start
= delalloc_end
+ 1;
3220 ret
= tree
->ops
->fill_delalloc(inode
, page
,
3225 /* File system has been set read-only */
3228 /* fill_delalloc should be return < 0 for error
3229 * but just in case, we use > 0 here meaning the
3230 * IO is started, so we don't want to return > 0
3231 * unless things are going well.
3233 ret
= ret
< 0 ? ret
: -EIO
;
3237 * delalloc_end is already one less than the total
3238 * length, so we don't subtract one from
3241 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3244 delalloc_start
= delalloc_end
+ 1;
3246 if (wbc
->nr_to_write
< delalloc_to_write
) {
3249 if (delalloc_to_write
< thresh
* 2)
3250 thresh
= delalloc_to_write
;
3251 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3255 /* did the fill delalloc function already unlock and start
3260 * we've unlocked the page, so we can't update
3261 * the mapping's writeback index, just update
3264 wbc
->nr_to_write
-= *nr_written
;
3275 * helper for __extent_writepage. This calls the writepage start hooks,
3276 * and does the loop to map the page into extents and bios.
3278 * We return 1 if the IO is started and the page is unlocked,
3279 * 0 if all went well (page still locked)
3280 * < 0 if there were errors (page still locked)
3282 static noinline_for_stack
int __extent_writepage_io(struct inode
*inode
,
3284 struct writeback_control
*wbc
,
3285 struct extent_page_data
*epd
,
3287 unsigned long nr_written
,
3288 int write_flags
, int *nr_ret
)
3290 struct extent_io_tree
*tree
= epd
->tree
;
3291 u64 start
= page_offset(page
);
3292 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
3299 struct extent_state
*cached_state
= NULL
;
3300 struct extent_map
*em
;
3301 struct block_device
*bdev
;
3302 size_t pg_offset
= 0;
3308 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3309 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3312 /* Fixup worker will requeue */
3314 wbc
->pages_skipped
++;
3316 redirty_page_for_writepage(wbc
, page
);
3318 update_nr_written(page
, wbc
, nr_written
);
3326 * we don't want to touch the inode after unlocking the page,
3327 * so we update the mapping writeback index now
3329 update_nr_written(page
, wbc
, nr_written
+ 1);
3332 if (i_size
<= start
) {
3333 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3334 tree
->ops
->writepage_end_io_hook(page
, start
,
3339 blocksize
= inode
->i_sb
->s_blocksize
;
3341 while (cur
<= end
) {
3343 if (cur
>= i_size
) {
3344 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3345 tree
->ops
->writepage_end_io_hook(page
, cur
,
3349 em
= epd
->get_extent(inode
, page
, pg_offset
, cur
,
3351 if (IS_ERR_OR_NULL(em
)) {
3353 ret
= PTR_ERR_OR_ZERO(em
);
3357 extent_offset
= cur
- em
->start
;
3358 em_end
= extent_map_end(em
);
3359 BUG_ON(em_end
<= cur
);
3361 iosize
= min(em_end
- cur
, end
- cur
+ 1);
3362 iosize
= ALIGN(iosize
, blocksize
);
3363 sector
= (em
->block_start
+ extent_offset
) >> 9;
3365 block_start
= em
->block_start
;
3366 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3367 free_extent_map(em
);
3371 * compressed and inline extents are written through other
3374 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3375 block_start
== EXTENT_MAP_INLINE
) {
3377 * end_io notification does not happen here for
3378 * compressed extents
3380 if (!compressed
&& tree
->ops
&&
3381 tree
->ops
->writepage_end_io_hook
)
3382 tree
->ops
->writepage_end_io_hook(page
, cur
,
3385 else if (compressed
) {
3386 /* we don't want to end_page_writeback on
3387 * a compressed extent. this happens
3394 pg_offset
+= iosize
;
3398 if (tree
->ops
&& tree
->ops
->writepage_io_hook
) {
3399 ret
= tree
->ops
->writepage_io_hook(page
, cur
,
3407 unsigned long max_nr
= (i_size
>> PAGE_CACHE_SHIFT
) + 1;
3409 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3410 if (!PageWriteback(page
)) {
3411 btrfs_err(BTRFS_I(inode
)->root
->fs_info
,
3412 "page %lu not writeback, cur %llu end %llu",
3413 page
->index
, cur
, end
);
3416 ret
= submit_extent_page(write_flags
, tree
, page
,
3417 sector
, iosize
, pg_offset
,
3418 bdev
, &epd
->bio
, max_nr
,
3419 end_bio_extent_writepage
,
3425 pg_offset
+= iosize
;
3433 /* drop our reference on any cached states */
3434 free_extent_state(cached_state
);
3439 * the writepage semantics are similar to regular writepage. extent
3440 * records are inserted to lock ranges in the tree, and as dirty areas
3441 * are found, they are marked writeback. Then the lock bits are removed
3442 * and the end_io handler clears the writeback ranges
3444 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
3447 struct inode
*inode
= page
->mapping
->host
;
3448 struct extent_page_data
*epd
= data
;
3449 u64 start
= page_offset(page
);
3450 u64 page_end
= start
+ PAGE_CACHE_SIZE
- 1;
3453 size_t pg_offset
= 0;
3454 loff_t i_size
= i_size_read(inode
);
3455 unsigned long end_index
= i_size
>> PAGE_CACHE_SHIFT
;
3457 unsigned long nr_written
= 0;
3459 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3460 write_flags
= WRITE_SYNC
;
3462 write_flags
= WRITE
;
3464 trace___extent_writepage(page
, inode
, wbc
);
3466 WARN_ON(!PageLocked(page
));
3468 ClearPageError(page
);
3470 pg_offset
= i_size
& (PAGE_CACHE_SIZE
- 1);
3471 if (page
->index
> end_index
||
3472 (page
->index
== end_index
&& !pg_offset
)) {
3473 page
->mapping
->a_ops
->invalidatepage(page
, 0, PAGE_CACHE_SIZE
);
3478 if (page
->index
== end_index
) {
3481 userpage
= kmap_atomic(page
);
3482 memset(userpage
+ pg_offset
, 0,
3483 PAGE_CACHE_SIZE
- pg_offset
);
3484 kunmap_atomic(userpage
);
3485 flush_dcache_page(page
);
3490 set_page_extent_mapped(page
);
3492 ret
= writepage_delalloc(inode
, page
, wbc
, epd
, start
, &nr_written
);
3498 ret
= __extent_writepage_io(inode
, page
, wbc
, epd
,
3499 i_size
, nr_written
, write_flags
, &nr
);
3505 /* make sure the mapping tag for page dirty gets cleared */
3506 set_page_writeback(page
);
3507 end_page_writeback(page
);
3509 if (PageError(page
)) {
3510 ret
= ret
< 0 ? ret
: -EIO
;
3511 end_extent_writepage(page
, ret
, start
, page_end
);
3520 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3522 wait_on_bit_io(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
,
3523 TASK_UNINTERRUPTIBLE
);
3526 static noinline_for_stack
int
3527 lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3528 struct btrfs_fs_info
*fs_info
,
3529 struct extent_page_data
*epd
)
3531 unsigned long i
, num_pages
;
3535 if (!btrfs_try_tree_write_lock(eb
)) {
3537 flush_write_bio(epd
);
3538 btrfs_tree_lock(eb
);
3541 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3542 btrfs_tree_unlock(eb
);
3546 flush_write_bio(epd
);
3550 wait_on_extent_buffer_writeback(eb
);
3551 btrfs_tree_lock(eb
);
3552 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3554 btrfs_tree_unlock(eb
);
3559 * We need to do this to prevent races in people who check if the eb is
3560 * under IO since we can end up having no IO bits set for a short period
3563 spin_lock(&eb
->refs_lock
);
3564 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3565 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3566 spin_unlock(&eb
->refs_lock
);
3567 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3568 __percpu_counter_add(&fs_info
->dirty_metadata_bytes
,
3570 fs_info
->dirty_metadata_batch
);
3573 spin_unlock(&eb
->refs_lock
);
3576 btrfs_tree_unlock(eb
);
3581 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3582 for (i
= 0; i
< num_pages
; i
++) {
3583 struct page
*p
= eb
->pages
[i
];
3585 if (!trylock_page(p
)) {
3587 flush_write_bio(epd
);
3597 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3599 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3600 smp_mb__after_atomic();
3601 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3604 static void set_btree_ioerr(struct page
*page
)
3606 struct extent_buffer
*eb
= (struct extent_buffer
*)page
->private;
3607 struct btrfs_inode
*btree_ino
= BTRFS_I(eb
->fs_info
->btree_inode
);
3610 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
))
3614 * If writeback for a btree extent that doesn't belong to a log tree
3615 * failed, increment the counter transaction->eb_write_errors.
3616 * We do this because while the transaction is running and before it's
3617 * committing (when we call filemap_fdata[write|wait]_range against
3618 * the btree inode), we might have
3619 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3620 * returns an error or an error happens during writeback, when we're
3621 * committing the transaction we wouldn't know about it, since the pages
3622 * can be no longer dirty nor marked anymore for writeback (if a
3623 * subsequent modification to the extent buffer didn't happen before the
3624 * transaction commit), which makes filemap_fdata[write|wait]_range not
3625 * able to find the pages tagged with SetPageError at transaction
3626 * commit time. So if this happens we must abort the transaction,
3627 * otherwise we commit a super block with btree roots that point to
3628 * btree nodes/leafs whose content on disk is invalid - either garbage
3629 * or the content of some node/leaf from a past generation that got
3630 * cowed or deleted and is no longer valid.
3632 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3633 * not be enough - we need to distinguish between log tree extents vs
3634 * non-log tree extents, and the next filemap_fdatawait_range() call
3635 * will catch and clear such errors in the mapping - and that call might
3636 * be from a log sync and not from a transaction commit. Also, checking
3637 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3638 * not done and would not be reliable - the eb might have been released
3639 * from memory and reading it back again means that flag would not be
3640 * set (since it's a runtime flag, not persisted on disk).
3642 * Using the flags below in the btree inode also makes us achieve the
3643 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3644 * writeback for all dirty pages and before filemap_fdatawait_range()
3645 * is called, the writeback for all dirty pages had already finished
3646 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3647 * filemap_fdatawait_range() would return success, as it could not know
3648 * that writeback errors happened (the pages were no longer tagged for
3651 switch (eb
->log_index
) {
3653 set_bit(BTRFS_INODE_BTREE_ERR
, &btree_ino
->runtime_flags
);
3656 set_bit(BTRFS_INODE_BTREE_LOG1_ERR
, &btree_ino
->runtime_flags
);
3659 set_bit(BTRFS_INODE_BTREE_LOG2_ERR
, &btree_ino
->runtime_flags
);
3662 BUG(); /* unexpected, logic error */
3666 static void end_bio_extent_buffer_writepage(struct bio
*bio
, int err
)
3668 struct bio_vec
*bvec
;
3669 struct extent_buffer
*eb
;
3672 bio_for_each_segment_all(bvec
, bio
, i
) {
3673 struct page
*page
= bvec
->bv_page
;
3675 eb
= (struct extent_buffer
*)page
->private;
3677 done
= atomic_dec_and_test(&eb
->io_pages
);
3679 if (err
|| test_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
)) {
3680 ClearPageUptodate(page
);
3681 set_btree_ioerr(page
);
3684 end_page_writeback(page
);
3689 end_extent_buffer_writeback(eb
);
3695 static noinline_for_stack
int write_one_eb(struct extent_buffer
*eb
,
3696 struct btrfs_fs_info
*fs_info
,
3697 struct writeback_control
*wbc
,
3698 struct extent_page_data
*epd
)
3700 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3701 struct extent_io_tree
*tree
= &BTRFS_I(fs_info
->btree_inode
)->io_tree
;
3702 u64 offset
= eb
->start
;
3703 unsigned long i
, num_pages
;
3704 unsigned long bio_flags
= 0;
3705 int rw
= (epd
->sync_io
? WRITE_SYNC
: WRITE
) | REQ_META
;
3708 clear_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
);
3709 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3710 atomic_set(&eb
->io_pages
, num_pages
);
3711 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3712 bio_flags
= EXTENT_BIO_TREE_LOG
;
3714 for (i
= 0; i
< num_pages
; i
++) {
3715 struct page
*p
= eb
->pages
[i
];
3717 clear_page_dirty_for_io(p
);
3718 set_page_writeback(p
);
3719 ret
= submit_extent_page(rw
, tree
, p
, offset
>> 9,
3720 PAGE_CACHE_SIZE
, 0, bdev
, &epd
->bio
,
3721 -1, end_bio_extent_buffer_writepage
,
3722 0, epd
->bio_flags
, bio_flags
);
3723 epd
->bio_flags
= bio_flags
;
3726 end_page_writeback(p
);
3727 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3728 end_extent_buffer_writeback(eb
);
3732 offset
+= PAGE_CACHE_SIZE
;
3733 update_nr_written(p
, wbc
, 1);
3737 if (unlikely(ret
)) {
3738 for (; i
< num_pages
; i
++) {
3739 struct page
*p
= eb
->pages
[i
];
3740 clear_page_dirty_for_io(p
);
3748 int btree_write_cache_pages(struct address_space
*mapping
,
3749 struct writeback_control
*wbc
)
3751 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3752 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3753 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3754 struct extent_page_data epd
= {
3758 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3763 int nr_to_write_done
= 0;
3764 struct pagevec pvec
;
3767 pgoff_t end
; /* Inclusive */
3771 pagevec_init(&pvec
, 0);
3772 if (wbc
->range_cyclic
) {
3773 index
= mapping
->writeback_index
; /* Start from prev offset */
3776 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3777 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3780 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3781 tag
= PAGECACHE_TAG_TOWRITE
;
3783 tag
= PAGECACHE_TAG_DIRTY
;
3785 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3786 tag_pages_for_writeback(mapping
, index
, end
);
3787 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3788 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3789 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3793 for (i
= 0; i
< nr_pages
; i
++) {
3794 struct page
*page
= pvec
.pages
[i
];
3796 if (!PagePrivate(page
))
3799 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3804 spin_lock(&mapping
->private_lock
);
3805 if (!PagePrivate(page
)) {
3806 spin_unlock(&mapping
->private_lock
);
3810 eb
= (struct extent_buffer
*)page
->private;
3813 * Shouldn't happen and normally this would be a BUG_ON
3814 * but no sense in crashing the users box for something
3815 * we can survive anyway.
3818 spin_unlock(&mapping
->private_lock
);
3822 if (eb
== prev_eb
) {
3823 spin_unlock(&mapping
->private_lock
);
3827 ret
= atomic_inc_not_zero(&eb
->refs
);
3828 spin_unlock(&mapping
->private_lock
);
3833 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3835 free_extent_buffer(eb
);
3839 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3842 free_extent_buffer(eb
);
3845 free_extent_buffer(eb
);
3848 * the filesystem may choose to bump up nr_to_write.
3849 * We have to make sure to honor the new nr_to_write
3852 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3854 pagevec_release(&pvec
);
3857 if (!scanned
&& !done
) {
3859 * We hit the last page and there is more work to be done: wrap
3860 * back to the start of the file
3866 flush_write_bio(&epd
);
3871 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3872 * @mapping: address space structure to write
3873 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3874 * @writepage: function called for each page
3875 * @data: data passed to writepage function
3877 * If a page is already under I/O, write_cache_pages() skips it, even
3878 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3879 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3880 * and msync() need to guarantee that all the data which was dirty at the time
3881 * the call was made get new I/O started against them. If wbc->sync_mode is
3882 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3883 * existing IO to complete.
3885 static int extent_write_cache_pages(struct extent_io_tree
*tree
,
3886 struct address_space
*mapping
,
3887 struct writeback_control
*wbc
,
3888 writepage_t writepage
, void *data
,
3889 void (*flush_fn
)(void *))
3891 struct inode
*inode
= mapping
->host
;
3895 int nr_to_write_done
= 0;
3896 struct pagevec pvec
;
3899 pgoff_t end
; /* Inclusive */
3904 * We have to hold onto the inode so that ordered extents can do their
3905 * work when the IO finishes. The alternative to this is failing to add
3906 * an ordered extent if the igrab() fails there and that is a huge pain
3907 * to deal with, so instead just hold onto the inode throughout the
3908 * writepages operation. If it fails here we are freeing up the inode
3909 * anyway and we'd rather not waste our time writing out stuff that is
3910 * going to be truncated anyway.
3915 pagevec_init(&pvec
, 0);
3916 if (wbc
->range_cyclic
) {
3917 index
= mapping
->writeback_index
; /* Start from prev offset */
3920 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
3921 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
3924 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3925 tag
= PAGECACHE_TAG_TOWRITE
;
3927 tag
= PAGECACHE_TAG_DIRTY
;
3929 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3930 tag_pages_for_writeback(mapping
, index
, end
);
3931 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3932 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3933 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3937 for (i
= 0; i
< nr_pages
; i
++) {
3938 struct page
*page
= pvec
.pages
[i
];
3941 * At this point we hold neither mapping->tree_lock nor
3942 * lock on the page itself: the page may be truncated or
3943 * invalidated (changing page->mapping to NULL), or even
3944 * swizzled back from swapper_space to tmpfs file
3947 if (!trylock_page(page
)) {
3952 if (unlikely(page
->mapping
!= mapping
)) {
3957 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3963 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
3964 if (PageWriteback(page
))
3966 wait_on_page_writeback(page
);
3969 if (PageWriteback(page
) ||
3970 !clear_page_dirty_for_io(page
)) {
3975 ret
= (*writepage
)(page
, wbc
, data
);
3977 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
3981 if (!err
&& ret
< 0)
3985 * the filesystem may choose to bump up nr_to_write.
3986 * We have to make sure to honor the new nr_to_write
3989 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3991 pagevec_release(&pvec
);
3994 if (!scanned
&& !done
&& !err
) {
3996 * We hit the last page and there is more work to be done: wrap
3997 * back to the start of the file
4003 btrfs_add_delayed_iput(inode
);
4007 static void flush_epd_write_bio(struct extent_page_data
*epd
)
4016 ret
= submit_one_bio(rw
, epd
->bio
, 0, epd
->bio_flags
);
4017 BUG_ON(ret
< 0); /* -ENOMEM */
4022 static noinline
void flush_write_bio(void *data
)
4024 struct extent_page_data
*epd
= data
;
4025 flush_epd_write_bio(epd
);
4028 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
4029 get_extent_t
*get_extent
,
4030 struct writeback_control
*wbc
)
4033 struct extent_page_data epd
= {
4036 .get_extent
= get_extent
,
4038 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
4042 ret
= __extent_writepage(page
, wbc
, &epd
);
4044 flush_epd_write_bio(&epd
);
4048 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
4049 u64 start
, u64 end
, get_extent_t
*get_extent
,
4053 struct address_space
*mapping
= inode
->i_mapping
;
4055 unsigned long nr_pages
= (end
- start
+ PAGE_CACHE_SIZE
) >>
4058 struct extent_page_data epd
= {
4061 .get_extent
= get_extent
,
4063 .sync_io
= mode
== WB_SYNC_ALL
,
4066 struct writeback_control wbc_writepages
= {
4068 .nr_to_write
= nr_pages
* 2,
4069 .range_start
= start
,
4070 .range_end
= end
+ 1,
4073 while (start
<= end
) {
4074 page
= find_get_page(mapping
, start
>> PAGE_CACHE_SHIFT
);
4075 if (clear_page_dirty_for_io(page
))
4076 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
4078 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
4079 tree
->ops
->writepage_end_io_hook(page
, start
,
4080 start
+ PAGE_CACHE_SIZE
- 1,
4084 page_cache_release(page
);
4085 start
+= PAGE_CACHE_SIZE
;
4088 flush_epd_write_bio(&epd
);
4092 int extent_writepages(struct extent_io_tree
*tree
,
4093 struct address_space
*mapping
,
4094 get_extent_t
*get_extent
,
4095 struct writeback_control
*wbc
)
4098 struct extent_page_data epd
= {
4101 .get_extent
= get_extent
,
4103 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
4107 ret
= extent_write_cache_pages(tree
, mapping
, wbc
,
4108 __extent_writepage
, &epd
,
4110 flush_epd_write_bio(&epd
);
4114 int extent_readpages(struct extent_io_tree
*tree
,
4115 struct address_space
*mapping
,
4116 struct list_head
*pages
, unsigned nr_pages
,
4117 get_extent_t get_extent
)
4119 struct bio
*bio
= NULL
;
4121 unsigned long bio_flags
= 0;
4122 struct page
*pagepool
[16];
4124 struct extent_map
*em_cached
= NULL
;
4127 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
4128 page
= list_entry(pages
->prev
, struct page
, lru
);
4130 prefetchw(&page
->flags
);
4131 list_del(&page
->lru
);
4132 if (add_to_page_cache_lru(page
, mapping
,
4133 page
->index
, GFP_NOFS
)) {
4134 page_cache_release(page
);
4138 pagepool
[nr
++] = page
;
4139 if (nr
< ARRAY_SIZE(pagepool
))
4141 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
4142 &bio
, 0, &bio_flags
, READ
);
4146 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
4147 &bio
, 0, &bio_flags
, READ
);
4150 free_extent_map(em_cached
);
4152 BUG_ON(!list_empty(pages
));
4154 return submit_one_bio(READ
, bio
, 0, bio_flags
);
4159 * basic invalidatepage code, this waits on any locked or writeback
4160 * ranges corresponding to the page, and then deletes any extent state
4161 * records from the tree
4163 int extent_invalidatepage(struct extent_io_tree
*tree
,
4164 struct page
*page
, unsigned long offset
)
4166 struct extent_state
*cached_state
= NULL
;
4167 u64 start
= page_offset(page
);
4168 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
4169 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
4171 start
+= ALIGN(offset
, blocksize
);
4175 lock_extent_bits(tree
, start
, end
, 0, &cached_state
);
4176 wait_on_page_writeback(page
);
4177 clear_extent_bit(tree
, start
, end
,
4178 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
4179 EXTENT_DO_ACCOUNTING
,
4180 1, 1, &cached_state
, GFP_NOFS
);
4185 * a helper for releasepage, this tests for areas of the page that
4186 * are locked or under IO and drops the related state bits if it is safe
4189 static int try_release_extent_state(struct extent_map_tree
*map
,
4190 struct extent_io_tree
*tree
,
4191 struct page
*page
, gfp_t mask
)
4193 u64 start
= page_offset(page
);
4194 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
4197 if (test_range_bit(tree
, start
, end
,
4198 EXTENT_IOBITS
, 0, NULL
))
4201 if ((mask
& GFP_NOFS
) == GFP_NOFS
)
4204 * at this point we can safely clear everything except the
4205 * locked bit and the nodatasum bit
4207 ret
= clear_extent_bit(tree
, start
, end
,
4208 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
4211 /* if clear_extent_bit failed for enomem reasons,
4212 * we can't allow the release to continue.
4223 * a helper for releasepage. As long as there are no locked extents
4224 * in the range corresponding to the page, both state records and extent
4225 * map records are removed
4227 int try_release_extent_mapping(struct extent_map_tree
*map
,
4228 struct extent_io_tree
*tree
, struct page
*page
,
4231 struct extent_map
*em
;
4232 u64 start
= page_offset(page
);
4233 u64 end
= start
+ PAGE_CACHE_SIZE
- 1;
4235 if ((mask
& __GFP_WAIT
) &&
4236 page
->mapping
->host
->i_size
> 16 * 1024 * 1024) {
4238 while (start
<= end
) {
4239 len
= end
- start
+ 1;
4240 write_lock(&map
->lock
);
4241 em
= lookup_extent_mapping(map
, start
, len
);
4243 write_unlock(&map
->lock
);
4246 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
4247 em
->start
!= start
) {
4248 write_unlock(&map
->lock
);
4249 free_extent_map(em
);
4252 if (!test_range_bit(tree
, em
->start
,
4253 extent_map_end(em
) - 1,
4254 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
4256 remove_extent_mapping(map
, em
);
4257 /* once for the rb tree */
4258 free_extent_map(em
);
4260 start
= extent_map_end(em
);
4261 write_unlock(&map
->lock
);
4264 free_extent_map(em
);
4267 return try_release_extent_state(map
, tree
, page
, mask
);
4271 * helper function for fiemap, which doesn't want to see any holes.
4272 * This maps until we find something past 'last'
4274 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
4277 get_extent_t
*get_extent
)
4279 u64 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
4280 struct extent_map
*em
;
4287 len
= last
- offset
;
4290 len
= ALIGN(len
, sectorsize
);
4291 em
= get_extent(inode
, NULL
, 0, offset
, len
, 0);
4292 if (IS_ERR_OR_NULL(em
))
4295 /* if this isn't a hole return it */
4296 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
4297 em
->block_start
!= EXTENT_MAP_HOLE
) {
4301 /* this is a hole, advance to the next extent */
4302 offset
= extent_map_end(em
);
4303 free_extent_map(em
);
4310 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4311 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
4315 u64 max
= start
+ len
;
4319 u64 last_for_get_extent
= 0;
4321 u64 isize
= i_size_read(inode
);
4322 struct btrfs_key found_key
;
4323 struct extent_map
*em
= NULL
;
4324 struct extent_state
*cached_state
= NULL
;
4325 struct btrfs_path
*path
;
4326 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4335 path
= btrfs_alloc_path();
4338 path
->leave_spinning
= 1;
4340 start
= round_down(start
, BTRFS_I(inode
)->root
->sectorsize
);
4341 len
= round_up(max
, BTRFS_I(inode
)->root
->sectorsize
) - start
;
4344 * lookup the last file extent. We're not using i_size here
4345 * because there might be preallocation past i_size
4347 ret
= btrfs_lookup_file_extent(NULL
, root
, path
, btrfs_ino(inode
), -1,
4350 btrfs_free_path(path
);
4355 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
4356 found_type
= found_key
.type
;
4358 /* No extents, but there might be delalloc bits */
4359 if (found_key
.objectid
!= btrfs_ino(inode
) ||
4360 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
4361 /* have to trust i_size as the end */
4363 last_for_get_extent
= isize
;
4366 * remember the start of the last extent. There are a
4367 * bunch of different factors that go into the length of the
4368 * extent, so its much less complex to remember where it started
4370 last
= found_key
.offset
;
4371 last_for_get_extent
= last
+ 1;
4373 btrfs_release_path(path
);
4376 * we might have some extents allocated but more delalloc past those
4377 * extents. so, we trust isize unless the start of the last extent is
4382 last_for_get_extent
= isize
;
4385 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1, 0,
4388 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4398 u64 offset_in_extent
= 0;
4400 /* break if the extent we found is outside the range */
4401 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4405 * get_extent may return an extent that starts before our
4406 * requested range. We have to make sure the ranges
4407 * we return to fiemap always move forward and don't
4408 * overlap, so adjust the offsets here
4410 em_start
= max(em
->start
, off
);
4413 * record the offset from the start of the extent
4414 * for adjusting the disk offset below. Only do this if the
4415 * extent isn't compressed since our in ram offset may be past
4416 * what we have actually allocated on disk.
4418 if (!test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4419 offset_in_extent
= em_start
- em
->start
;
4420 em_end
= extent_map_end(em
);
4421 em_len
= em_end
- em_start
;
4426 * bump off for our next call to get_extent
4428 off
= extent_map_end(em
);
4432 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4434 flags
|= FIEMAP_EXTENT_LAST
;
4435 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4436 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4437 FIEMAP_EXTENT_NOT_ALIGNED
);
4438 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4439 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4440 FIEMAP_EXTENT_UNKNOWN
);
4441 } else if (fieinfo
->fi_extents_max
) {
4442 u64 bytenr
= em
->block_start
-
4443 (em
->start
- em
->orig_start
);
4445 disko
= em
->block_start
+ offset_in_extent
;
4448 * As btrfs supports shared space, this information
4449 * can be exported to userspace tools via
4450 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4451 * then we're just getting a count and we can skip the
4454 ret
= btrfs_check_shared(NULL
, root
->fs_info
,
4456 btrfs_ino(inode
), bytenr
);
4460 flags
|= FIEMAP_EXTENT_SHARED
;
4463 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4464 flags
|= FIEMAP_EXTENT_ENCODED
;
4466 free_extent_map(em
);
4468 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4469 (last
== (u64
)-1 && isize
<= em_end
)) {
4470 flags
|= FIEMAP_EXTENT_LAST
;
4474 /* now scan forward to see if this is really the last extent. */
4475 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4482 flags
|= FIEMAP_EXTENT_LAST
;
4485 ret
= fiemap_fill_next_extent(fieinfo
, em_start
, disko
,
4491 free_extent_map(em
);
4493 btrfs_free_path(path
);
4494 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4495 &cached_state
, GFP_NOFS
);
4499 static void __free_extent_buffer(struct extent_buffer
*eb
)
4501 btrfs_leak_debug_del(&eb
->leak_list
);
4502 kmem_cache_free(extent_buffer_cache
, eb
);
4505 int extent_buffer_under_io(struct extent_buffer
*eb
)
4507 return (atomic_read(&eb
->io_pages
) ||
4508 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4509 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4513 * Helper for releasing extent buffer page.
4515 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
)
4517 unsigned long index
;
4519 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4521 BUG_ON(extent_buffer_under_io(eb
));
4523 index
= num_extent_pages(eb
->start
, eb
->len
);
4529 page
= eb
->pages
[index
];
4530 if (page
&& mapped
) {
4531 spin_lock(&page
->mapping
->private_lock
);
4533 * We do this since we'll remove the pages after we've
4534 * removed the eb from the radix tree, so we could race
4535 * and have this page now attached to the new eb. So
4536 * only clear page_private if it's still connected to
4539 if (PagePrivate(page
) &&
4540 page
->private == (unsigned long)eb
) {
4541 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4542 BUG_ON(PageDirty(page
));
4543 BUG_ON(PageWriteback(page
));
4545 * We need to make sure we haven't be attached
4548 ClearPagePrivate(page
);
4549 set_page_private(page
, 0);
4550 /* One for the page private */
4551 page_cache_release(page
);
4553 spin_unlock(&page
->mapping
->private_lock
);
4557 /* One for when we alloced the page */
4558 page_cache_release(page
);
4560 } while (index
!= 0);
4564 * Helper for releasing the extent buffer.
4566 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4568 btrfs_release_extent_buffer_page(eb
);
4569 __free_extent_buffer(eb
);
4572 static struct extent_buffer
*
4573 __alloc_extent_buffer(struct btrfs_fs_info
*fs_info
, u64 start
,
4574 unsigned long len
, gfp_t mask
)
4576 struct extent_buffer
*eb
= NULL
;
4578 eb
= kmem_cache_zalloc(extent_buffer_cache
, mask
);
4583 eb
->fs_info
= fs_info
;
4585 rwlock_init(&eb
->lock
);
4586 atomic_set(&eb
->write_locks
, 0);
4587 atomic_set(&eb
->read_locks
, 0);
4588 atomic_set(&eb
->blocking_readers
, 0);
4589 atomic_set(&eb
->blocking_writers
, 0);
4590 atomic_set(&eb
->spinning_readers
, 0);
4591 atomic_set(&eb
->spinning_writers
, 0);
4592 eb
->lock_nested
= 0;
4593 init_waitqueue_head(&eb
->write_lock_wq
);
4594 init_waitqueue_head(&eb
->read_lock_wq
);
4596 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4598 spin_lock_init(&eb
->refs_lock
);
4599 atomic_set(&eb
->refs
, 1);
4600 atomic_set(&eb
->io_pages
, 0);
4603 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4605 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4606 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4607 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4612 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4616 struct extent_buffer
*new;
4617 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4619 new = __alloc_extent_buffer(NULL
, src
->start
, src
->len
, GFP_NOFS
);
4623 for (i
= 0; i
< num_pages
; i
++) {
4624 p
= alloc_page(GFP_NOFS
);
4626 btrfs_release_extent_buffer(new);
4629 attach_extent_buffer_page(new, p
);
4630 WARN_ON(PageDirty(p
));
4635 copy_extent_buffer(new, src
, 0, 0, src
->len
);
4636 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4637 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4642 struct extent_buffer
*alloc_dummy_extent_buffer(u64 start
, unsigned long len
)
4644 struct extent_buffer
*eb
;
4645 unsigned long num_pages
= num_extent_pages(0, len
);
4648 eb
= __alloc_extent_buffer(NULL
, start
, len
, GFP_NOFS
);
4652 for (i
= 0; i
< num_pages
; i
++) {
4653 eb
->pages
[i
] = alloc_page(GFP_NOFS
);
4657 set_extent_buffer_uptodate(eb
);
4658 btrfs_set_header_nritems(eb
, 0);
4659 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4664 __free_page(eb
->pages
[i
- 1]);
4665 __free_extent_buffer(eb
);
4669 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4672 /* the ref bit is tricky. We have to make sure it is set
4673 * if we have the buffer dirty. Otherwise the
4674 * code to free a buffer can end up dropping a dirty
4677 * Once the ref bit is set, it won't go away while the
4678 * buffer is dirty or in writeback, and it also won't
4679 * go away while we have the reference count on the
4682 * We can't just set the ref bit without bumping the
4683 * ref on the eb because free_extent_buffer might
4684 * see the ref bit and try to clear it. If this happens
4685 * free_extent_buffer might end up dropping our original
4686 * ref by mistake and freeing the page before we are able
4687 * to add one more ref.
4689 * So bump the ref count first, then set the bit. If someone
4690 * beat us to it, drop the ref we added.
4692 refs
= atomic_read(&eb
->refs
);
4693 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4696 spin_lock(&eb
->refs_lock
);
4697 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4698 atomic_inc(&eb
->refs
);
4699 spin_unlock(&eb
->refs_lock
);
4702 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
,
4703 struct page
*accessed
)
4705 unsigned long num_pages
, i
;
4707 check_buffer_tree_ref(eb
);
4709 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4710 for (i
= 0; i
< num_pages
; i
++) {
4711 struct page
*p
= eb
->pages
[i
];
4714 mark_page_accessed(p
);
4718 struct extent_buffer
*find_extent_buffer(struct btrfs_fs_info
*fs_info
,
4721 struct extent_buffer
*eb
;
4724 eb
= radix_tree_lookup(&fs_info
->buffer_radix
,
4725 start
>> PAGE_CACHE_SHIFT
);
4726 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4728 mark_extent_buffer_accessed(eb
, NULL
);
4736 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4737 struct extent_buffer
*alloc_test_extent_buffer(struct btrfs_fs_info
*fs_info
,
4738 u64 start
, unsigned long len
)
4740 struct extent_buffer
*eb
, *exists
= NULL
;
4743 eb
= find_extent_buffer(fs_info
, start
);
4746 eb
= alloc_dummy_extent_buffer(start
, len
);
4749 eb
->fs_info
= fs_info
;
4751 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
4754 spin_lock(&fs_info
->buffer_lock
);
4755 ret
= radix_tree_insert(&fs_info
->buffer_radix
,
4756 start
>> PAGE_CACHE_SHIFT
, eb
);
4757 spin_unlock(&fs_info
->buffer_lock
);
4758 radix_tree_preload_end();
4759 if (ret
== -EEXIST
) {
4760 exists
= find_extent_buffer(fs_info
, start
);
4766 check_buffer_tree_ref(eb
);
4767 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
4770 * We will free dummy extent buffer's if they come into
4771 * free_extent_buffer with a ref count of 2, but if we are using this we
4772 * want the buffers to stay in memory until we're done with them, so
4773 * bump the ref count again.
4775 atomic_inc(&eb
->refs
);
4778 btrfs_release_extent_buffer(eb
);
4783 struct extent_buffer
*alloc_extent_buffer(struct btrfs_fs_info
*fs_info
,
4784 u64 start
, unsigned long len
)
4786 unsigned long num_pages
= num_extent_pages(start
, len
);
4788 unsigned long index
= start
>> PAGE_CACHE_SHIFT
;
4789 struct extent_buffer
*eb
;
4790 struct extent_buffer
*exists
= NULL
;
4792 struct address_space
*mapping
= fs_info
->btree_inode
->i_mapping
;
4796 eb
= find_extent_buffer(fs_info
, start
);
4800 eb
= __alloc_extent_buffer(fs_info
, start
, len
, GFP_NOFS
);
4804 for (i
= 0; i
< num_pages
; i
++, index
++) {
4805 p
= find_or_create_page(mapping
, index
, GFP_NOFS
);
4809 spin_lock(&mapping
->private_lock
);
4810 if (PagePrivate(p
)) {
4812 * We could have already allocated an eb for this page
4813 * and attached one so lets see if we can get a ref on
4814 * the existing eb, and if we can we know it's good and
4815 * we can just return that one, else we know we can just
4816 * overwrite page->private.
4818 exists
= (struct extent_buffer
*)p
->private;
4819 if (atomic_inc_not_zero(&exists
->refs
)) {
4820 spin_unlock(&mapping
->private_lock
);
4822 page_cache_release(p
);
4823 mark_extent_buffer_accessed(exists
, p
);
4828 * Do this so attach doesn't complain and we need to
4829 * drop the ref the old guy had.
4831 ClearPagePrivate(p
);
4832 WARN_ON(PageDirty(p
));
4833 page_cache_release(p
);
4835 attach_extent_buffer_page(eb
, p
);
4836 spin_unlock(&mapping
->private_lock
);
4837 WARN_ON(PageDirty(p
));
4839 if (!PageUptodate(p
))
4843 * see below about how we avoid a nasty race with release page
4844 * and why we unlock later
4848 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
4850 ret
= radix_tree_preload(GFP_NOFS
& ~__GFP_HIGHMEM
);
4854 spin_lock(&fs_info
->buffer_lock
);
4855 ret
= radix_tree_insert(&fs_info
->buffer_radix
,
4856 start
>> PAGE_CACHE_SHIFT
, eb
);
4857 spin_unlock(&fs_info
->buffer_lock
);
4858 radix_tree_preload_end();
4859 if (ret
== -EEXIST
) {
4860 exists
= find_extent_buffer(fs_info
, start
);
4866 /* add one reference for the tree */
4867 check_buffer_tree_ref(eb
);
4868 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
4871 * there is a race where release page may have
4872 * tried to find this extent buffer in the radix
4873 * but failed. It will tell the VM it is safe to
4874 * reclaim the, and it will clear the page private bit.
4875 * We must make sure to set the page private bit properly
4876 * after the extent buffer is in the radix tree so
4877 * it doesn't get lost
4879 SetPageChecked(eb
->pages
[0]);
4880 for (i
= 1; i
< num_pages
; i
++) {
4882 ClearPageChecked(p
);
4885 unlock_page(eb
->pages
[0]);
4889 for (i
= 0; i
< num_pages
; i
++) {
4891 unlock_page(eb
->pages
[i
]);
4894 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
4895 btrfs_release_extent_buffer(eb
);
4899 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
4901 struct extent_buffer
*eb
=
4902 container_of(head
, struct extent_buffer
, rcu_head
);
4904 __free_extent_buffer(eb
);
4907 /* Expects to have eb->eb_lock already held */
4908 static int release_extent_buffer(struct extent_buffer
*eb
)
4910 WARN_ON(atomic_read(&eb
->refs
) == 0);
4911 if (atomic_dec_and_test(&eb
->refs
)) {
4912 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
)) {
4913 struct btrfs_fs_info
*fs_info
= eb
->fs_info
;
4915 spin_unlock(&eb
->refs_lock
);
4917 spin_lock(&fs_info
->buffer_lock
);
4918 radix_tree_delete(&fs_info
->buffer_radix
,
4919 eb
->start
>> PAGE_CACHE_SHIFT
);
4920 spin_unlock(&fs_info
->buffer_lock
);
4922 spin_unlock(&eb
->refs_lock
);
4925 /* Should be safe to release our pages at this point */
4926 btrfs_release_extent_buffer_page(eb
);
4927 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
4930 spin_unlock(&eb
->refs_lock
);
4935 void free_extent_buffer(struct extent_buffer
*eb
)
4943 refs
= atomic_read(&eb
->refs
);
4946 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
4951 spin_lock(&eb
->refs_lock
);
4952 if (atomic_read(&eb
->refs
) == 2 &&
4953 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
4954 atomic_dec(&eb
->refs
);
4956 if (atomic_read(&eb
->refs
) == 2 &&
4957 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
4958 !extent_buffer_under_io(eb
) &&
4959 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4960 atomic_dec(&eb
->refs
);
4963 * I know this is terrible, but it's temporary until we stop tracking
4964 * the uptodate bits and such for the extent buffers.
4966 release_extent_buffer(eb
);
4969 void free_extent_buffer_stale(struct extent_buffer
*eb
)
4974 spin_lock(&eb
->refs_lock
);
4975 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
4977 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
4978 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4979 atomic_dec(&eb
->refs
);
4980 release_extent_buffer(eb
);
4983 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
4986 unsigned long num_pages
;
4989 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4991 for (i
= 0; i
< num_pages
; i
++) {
4992 page
= eb
->pages
[i
];
4993 if (!PageDirty(page
))
4997 WARN_ON(!PagePrivate(page
));
4999 clear_page_dirty_for_io(page
);
5000 spin_lock_irq(&page
->mapping
->tree_lock
);
5001 if (!PageDirty(page
)) {
5002 radix_tree_tag_clear(&page
->mapping
->page_tree
,
5004 PAGECACHE_TAG_DIRTY
);
5006 spin_unlock_irq(&page
->mapping
->tree_lock
);
5007 ClearPageError(page
);
5010 WARN_ON(atomic_read(&eb
->refs
) == 0);
5013 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
5016 unsigned long num_pages
;
5019 check_buffer_tree_ref(eb
);
5021 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
5023 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5024 WARN_ON(atomic_read(&eb
->refs
) == 0);
5025 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
5027 for (i
= 0; i
< num_pages
; i
++)
5028 set_page_dirty(eb
->pages
[i
]);
5032 int clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
5036 unsigned long num_pages
;
5038 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5039 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5040 for (i
= 0; i
< num_pages
; i
++) {
5041 page
= eb
->pages
[i
];
5043 ClearPageUptodate(page
);
5048 int set_extent_buffer_uptodate(struct extent_buffer
*eb
)
5052 unsigned long num_pages
;
5054 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5055 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5056 for (i
= 0; i
< num_pages
; i
++) {
5057 page
= eb
->pages
[i
];
5058 SetPageUptodate(page
);
5063 int extent_buffer_uptodate(struct extent_buffer
*eb
)
5065 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5068 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
5069 struct extent_buffer
*eb
, u64 start
, int wait
,
5070 get_extent_t
*get_extent
, int mirror_num
)
5073 unsigned long start_i
;
5077 int locked_pages
= 0;
5078 int all_uptodate
= 1;
5079 unsigned long num_pages
;
5080 unsigned long num_reads
= 0;
5081 struct bio
*bio
= NULL
;
5082 unsigned long bio_flags
= 0;
5084 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
5088 WARN_ON(start
< eb
->start
);
5089 start_i
= (start
>> PAGE_CACHE_SHIFT
) -
5090 (eb
->start
>> PAGE_CACHE_SHIFT
);
5095 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5096 for (i
= start_i
; i
< num_pages
; i
++) {
5097 page
= eb
->pages
[i
];
5098 if (wait
== WAIT_NONE
) {
5099 if (!trylock_page(page
))
5105 if (!PageUptodate(page
)) {
5112 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5116 clear_bit(EXTENT_BUFFER_READ_ERR
, &eb
->bflags
);
5117 eb
->read_mirror
= 0;
5118 atomic_set(&eb
->io_pages
, num_reads
);
5119 for (i
= start_i
; i
< num_pages
; i
++) {
5120 page
= eb
->pages
[i
];
5121 if (!PageUptodate(page
)) {
5122 ClearPageError(page
);
5123 err
= __extent_read_full_page(tree
, page
,
5125 mirror_num
, &bio_flags
,
5135 err
= submit_one_bio(READ
| REQ_META
, bio
, mirror_num
,
5141 if (ret
|| wait
!= WAIT_COMPLETE
)
5144 for (i
= start_i
; i
< num_pages
; i
++) {
5145 page
= eb
->pages
[i
];
5146 wait_on_page_locked(page
);
5147 if (!PageUptodate(page
))
5155 while (locked_pages
> 0) {
5156 page
= eb
->pages
[i
];
5164 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
5165 unsigned long start
,
5172 char *dst
= (char *)dstv
;
5173 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5174 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5176 WARN_ON(start
> eb
->len
);
5177 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5179 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5182 page
= eb
->pages
[i
];
5184 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
5185 kaddr
= page_address(page
);
5186 memcpy(dst
, kaddr
+ offset
, cur
);
5195 int read_extent_buffer_to_user(struct extent_buffer
*eb
, void __user
*dstv
,
5196 unsigned long start
,
5203 char __user
*dst
= (char __user
*)dstv
;
5204 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5205 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5208 WARN_ON(start
> eb
->len
);
5209 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5211 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5214 page
= eb
->pages
[i
];
5216 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
5217 kaddr
= page_address(page
);
5218 if (copy_to_user(dst
, kaddr
+ offset
, cur
)) {
5232 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
5233 unsigned long min_len
, char **map
,
5234 unsigned long *map_start
,
5235 unsigned long *map_len
)
5237 size_t offset
= start
& (PAGE_CACHE_SIZE
- 1);
5240 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5241 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5242 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
5249 offset
= start_offset
;
5253 *map_start
= ((u64
)i
<< PAGE_CACHE_SHIFT
) - start_offset
;
5256 if (start
+ min_len
> eb
->len
) {
5257 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, "
5259 eb
->start
, eb
->len
, start
, min_len
);
5264 kaddr
= page_address(p
);
5265 *map
= kaddr
+ offset
;
5266 *map_len
= PAGE_CACHE_SIZE
- offset
;
5270 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
5271 unsigned long start
,
5278 char *ptr
= (char *)ptrv
;
5279 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5280 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5283 WARN_ON(start
> eb
->len
);
5284 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5286 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5289 page
= eb
->pages
[i
];
5291 cur
= min(len
, (PAGE_CACHE_SIZE
- offset
));
5293 kaddr
= page_address(page
);
5294 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
5306 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
5307 unsigned long start
, unsigned long len
)
5313 char *src
= (char *)srcv
;
5314 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5315 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5317 WARN_ON(start
> eb
->len
);
5318 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5320 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5323 page
= eb
->pages
[i
];
5324 WARN_ON(!PageUptodate(page
));
5326 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
5327 kaddr
= page_address(page
);
5328 memcpy(kaddr
+ offset
, src
, cur
);
5337 void memset_extent_buffer(struct extent_buffer
*eb
, char c
,
5338 unsigned long start
, unsigned long len
)
5344 size_t start_offset
= eb
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5345 unsigned long i
= (start_offset
+ start
) >> PAGE_CACHE_SHIFT
;
5347 WARN_ON(start
> eb
->len
);
5348 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5350 offset
= (start_offset
+ start
) & (PAGE_CACHE_SIZE
- 1);
5353 page
= eb
->pages
[i
];
5354 WARN_ON(!PageUptodate(page
));
5356 cur
= min(len
, PAGE_CACHE_SIZE
- offset
);
5357 kaddr
= page_address(page
);
5358 memset(kaddr
+ offset
, c
, cur
);
5366 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
5367 unsigned long dst_offset
, unsigned long src_offset
,
5370 u64 dst_len
= dst
->len
;
5375 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5376 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5378 WARN_ON(src
->len
!= dst_len
);
5380 offset
= (start_offset
+ dst_offset
) &
5381 (PAGE_CACHE_SIZE
- 1);
5384 page
= dst
->pages
[i
];
5385 WARN_ON(!PageUptodate(page
));
5387 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
- offset
));
5389 kaddr
= page_address(page
);
5390 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
5399 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
5401 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
5402 return distance
< len
;
5405 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
5406 unsigned long dst_off
, unsigned long src_off
,
5409 char *dst_kaddr
= page_address(dst_page
);
5411 int must_memmove
= 0;
5413 if (dst_page
!= src_page
) {
5414 src_kaddr
= page_address(src_page
);
5416 src_kaddr
= dst_kaddr
;
5417 if (areas_overlap(src_off
, dst_off
, len
))
5422 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5424 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5427 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5428 unsigned long src_offset
, unsigned long len
)
5431 size_t dst_off_in_page
;
5432 size_t src_off_in_page
;
5433 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5434 unsigned long dst_i
;
5435 unsigned long src_i
;
5437 if (src_offset
+ len
> dst
->len
) {
5438 printk(KERN_ERR
"BTRFS: memmove bogus src_offset %lu move "
5439 "len %lu dst len %lu\n", src_offset
, len
, dst
->len
);
5442 if (dst_offset
+ len
> dst
->len
) {
5443 printk(KERN_ERR
"BTRFS: memmove bogus dst_offset %lu move "
5444 "len %lu dst len %lu\n", dst_offset
, len
, dst
->len
);
5449 dst_off_in_page
= (start_offset
+ dst_offset
) &
5450 (PAGE_CACHE_SIZE
- 1);
5451 src_off_in_page
= (start_offset
+ src_offset
) &
5452 (PAGE_CACHE_SIZE
- 1);
5454 dst_i
= (start_offset
+ dst_offset
) >> PAGE_CACHE_SHIFT
;
5455 src_i
= (start_offset
+ src_offset
) >> PAGE_CACHE_SHIFT
;
5457 cur
= min(len
, (unsigned long)(PAGE_CACHE_SIZE
-
5459 cur
= min_t(unsigned long, cur
,
5460 (unsigned long)(PAGE_CACHE_SIZE
- dst_off_in_page
));
5462 copy_pages(dst
->pages
[dst_i
], dst
->pages
[src_i
],
5463 dst_off_in_page
, src_off_in_page
, cur
);
5471 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5472 unsigned long src_offset
, unsigned long len
)
5475 size_t dst_off_in_page
;
5476 size_t src_off_in_page
;
5477 unsigned long dst_end
= dst_offset
+ len
- 1;
5478 unsigned long src_end
= src_offset
+ len
- 1;
5479 size_t start_offset
= dst
->start
& ((u64
)PAGE_CACHE_SIZE
- 1);
5480 unsigned long dst_i
;
5481 unsigned long src_i
;
5483 if (src_offset
+ len
> dst
->len
) {
5484 printk(KERN_ERR
"BTRFS: memmove bogus src_offset %lu move "
5485 "len %lu len %lu\n", src_offset
, len
, dst
->len
);
5488 if (dst_offset
+ len
> dst
->len
) {
5489 printk(KERN_ERR
"BTRFS: memmove bogus dst_offset %lu move "
5490 "len %lu len %lu\n", dst_offset
, len
, dst
->len
);
5493 if (dst_offset
< src_offset
) {
5494 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5498 dst_i
= (start_offset
+ dst_end
) >> PAGE_CACHE_SHIFT
;
5499 src_i
= (start_offset
+ src_end
) >> PAGE_CACHE_SHIFT
;
5501 dst_off_in_page
= (start_offset
+ dst_end
) &
5502 (PAGE_CACHE_SIZE
- 1);
5503 src_off_in_page
= (start_offset
+ src_end
) &
5504 (PAGE_CACHE_SIZE
- 1);
5506 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5507 cur
= min(cur
, dst_off_in_page
+ 1);
5508 copy_pages(dst
->pages
[dst_i
], dst
->pages
[src_i
],
5509 dst_off_in_page
- cur
+ 1,
5510 src_off_in_page
- cur
+ 1, cur
);
5518 int try_release_extent_buffer(struct page
*page
)
5520 struct extent_buffer
*eb
;
5523 * We need to make sure noboody is attaching this page to an eb right
5526 spin_lock(&page
->mapping
->private_lock
);
5527 if (!PagePrivate(page
)) {
5528 spin_unlock(&page
->mapping
->private_lock
);
5532 eb
= (struct extent_buffer
*)page
->private;
5536 * This is a little awful but should be ok, we need to make sure that
5537 * the eb doesn't disappear out from under us while we're looking at
5540 spin_lock(&eb
->refs_lock
);
5541 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
5542 spin_unlock(&eb
->refs_lock
);
5543 spin_unlock(&page
->mapping
->private_lock
);
5546 spin_unlock(&page
->mapping
->private_lock
);
5549 * If tree ref isn't set then we know the ref on this eb is a real ref,
5550 * so just return, this page will likely be freed soon anyway.
5552 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
5553 spin_unlock(&eb
->refs_lock
);
5557 return release_extent_buffer(eb
);