1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/bitops.h>
4 #include <linux/slab.h>
7 #include <linux/pagemap.h>
8 #include <linux/page-flags.h>
9 #include <linux/spinlock.h>
10 #include <linux/blkdev.h>
11 #include <linux/swap.h>
12 #include <linux/writeback.h>
13 #include <linux/pagevec.h>
14 #include <linux/prefetch.h>
15 #include <linux/cleancache.h>
16 #include "extent_io.h"
17 #include "extent_map.h"
19 #include "btrfs_inode.h"
21 #include "check-integrity.h"
23 #include "rcu-string.h"
27 static struct kmem_cache
*extent_state_cache
;
28 static struct kmem_cache
*extent_buffer_cache
;
29 static struct bio_set btrfs_bioset
;
31 static inline bool extent_state_in_tree(const struct extent_state
*state
)
33 return !RB_EMPTY_NODE(&state
->rb_node
);
36 #ifdef CONFIG_BTRFS_DEBUG
37 static LIST_HEAD(buffers
);
38 static LIST_HEAD(states
);
40 static DEFINE_SPINLOCK(leak_lock
);
43 void btrfs_leak_debug_add(struct list_head
*new, struct list_head
*head
)
47 spin_lock_irqsave(&leak_lock
, flags
);
49 spin_unlock_irqrestore(&leak_lock
, flags
);
53 void btrfs_leak_debug_del(struct list_head
*entry
)
57 spin_lock_irqsave(&leak_lock
, flags
);
59 spin_unlock_irqrestore(&leak_lock
, flags
);
63 void btrfs_leak_debug_check(void)
65 struct extent_state
*state
;
66 struct extent_buffer
*eb
;
68 while (!list_empty(&states
)) {
69 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
70 pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
71 state
->start
, state
->end
, state
->state
,
72 extent_state_in_tree(state
),
73 refcount_read(&state
->refs
));
74 list_del(&state
->leak_list
);
75 kmem_cache_free(extent_state_cache
, state
);
78 while (!list_empty(&buffers
)) {
79 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
80 pr_err("BTRFS: buffer leak start %llu len %lu refs %d bflags %lu\n",
81 eb
->start
, eb
->len
, atomic_read(&eb
->refs
), eb
->bflags
);
82 list_del(&eb
->leak_list
);
83 kmem_cache_free(extent_buffer_cache
, eb
);
87 #define btrfs_debug_check_extent_io_range(tree, start, end) \
88 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
89 static inline void __btrfs_debug_check_extent_io_range(const char *caller
,
90 struct extent_io_tree
*tree
, u64 start
, u64 end
)
92 struct inode
*inode
= tree
->private_data
;
95 if (!inode
|| !is_data_inode(inode
))
98 isize
= i_size_read(inode
);
99 if (end
>= PAGE_SIZE
&& (end
% 2) == 0 && end
!= isize
- 1) {
100 btrfs_debug_rl(BTRFS_I(inode
)->root
->fs_info
,
101 "%s: ino %llu isize %llu odd range [%llu,%llu]",
102 caller
, btrfs_ino(BTRFS_I(inode
)), isize
, start
, end
);
106 #define btrfs_leak_debug_add(new, head) do {} while (0)
107 #define btrfs_leak_debug_del(entry) do {} while (0)
108 #define btrfs_leak_debug_check() do {} while (0)
109 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
115 struct rb_node rb_node
;
118 struct extent_page_data
{
120 struct extent_io_tree
*tree
;
121 /* tells writepage not to lock the state bits for this range
122 * it still does the unlocking
124 unsigned int extent_locked
:1;
126 /* tells the submit_bio code to use REQ_SYNC */
127 unsigned int sync_io
:1;
130 static int add_extent_changeset(struct extent_state
*state
, unsigned bits
,
131 struct extent_changeset
*changeset
,
138 if (set
&& (state
->state
& bits
) == bits
)
140 if (!set
&& (state
->state
& bits
) == 0)
142 changeset
->bytes_changed
+= state
->end
- state
->start
+ 1;
143 ret
= ulist_add(&changeset
->range_changed
, state
->start
, state
->end
,
148 static int __must_check
submit_one_bio(struct bio
*bio
, int mirror_num
,
149 unsigned long bio_flags
)
151 blk_status_t ret
= 0;
152 struct extent_io_tree
*tree
= bio
->bi_private
;
154 bio
->bi_private
= NULL
;
157 ret
= tree
->ops
->submit_bio_hook(tree
->private_data
, bio
,
158 mirror_num
, bio_flags
);
160 btrfsic_submit_bio(bio
);
162 return blk_status_to_errno(ret
);
165 /* Cleanup unsubmitted bios */
166 static void end_write_bio(struct extent_page_data
*epd
, int ret
)
169 epd
->bio
->bi_status
= errno_to_blk_status(ret
);
176 * Submit bio from extent page data via submit_one_bio
178 * Return 0 if everything is OK.
179 * Return <0 for error.
181 static int __must_check
flush_write_bio(struct extent_page_data
*epd
)
186 ret
= submit_one_bio(epd
->bio
, 0, 0);
188 * Clean up of epd->bio is handled by its endio function.
189 * And endio is either triggered by successful bio execution
190 * or the error handler of submit bio hook.
191 * So at this point, no matter what happened, we don't need
192 * to clean up epd->bio.
199 int __init
extent_io_init(void)
201 extent_state_cache
= kmem_cache_create("btrfs_extent_state",
202 sizeof(struct extent_state
), 0,
203 SLAB_MEM_SPREAD
, NULL
);
204 if (!extent_state_cache
)
207 extent_buffer_cache
= kmem_cache_create("btrfs_extent_buffer",
208 sizeof(struct extent_buffer
), 0,
209 SLAB_MEM_SPREAD
, NULL
);
210 if (!extent_buffer_cache
)
211 goto free_state_cache
;
213 if (bioset_init(&btrfs_bioset
, BIO_POOL_SIZE
,
214 offsetof(struct btrfs_io_bio
, bio
),
216 goto free_buffer_cache
;
218 if (bioset_integrity_create(&btrfs_bioset
, BIO_POOL_SIZE
))
224 bioset_exit(&btrfs_bioset
);
227 kmem_cache_destroy(extent_buffer_cache
);
228 extent_buffer_cache
= NULL
;
231 kmem_cache_destroy(extent_state_cache
);
232 extent_state_cache
= NULL
;
236 void __cold
extent_io_exit(void)
238 btrfs_leak_debug_check();
241 * Make sure all delayed rcu free are flushed before we
245 kmem_cache_destroy(extent_state_cache
);
246 kmem_cache_destroy(extent_buffer_cache
);
247 bioset_exit(&btrfs_bioset
);
250 void extent_io_tree_init(struct btrfs_fs_info
*fs_info
,
251 struct extent_io_tree
*tree
, unsigned int owner
,
254 tree
->fs_info
= fs_info
;
255 tree
->state
= RB_ROOT
;
257 tree
->dirty_bytes
= 0;
258 spin_lock_init(&tree
->lock
);
259 tree
->private_data
= private_data
;
263 void extent_io_tree_release(struct extent_io_tree
*tree
)
265 spin_lock(&tree
->lock
);
267 * Do a single barrier for the waitqueue_active check here, the state
268 * of the waitqueue should not change once extent_io_tree_release is
272 while (!RB_EMPTY_ROOT(&tree
->state
)) {
273 struct rb_node
*node
;
274 struct extent_state
*state
;
276 node
= rb_first(&tree
->state
);
277 state
= rb_entry(node
, struct extent_state
, rb_node
);
278 rb_erase(&state
->rb_node
, &tree
->state
);
279 RB_CLEAR_NODE(&state
->rb_node
);
281 * btree io trees aren't supposed to have tasks waiting for
282 * changes in the flags of extent states ever.
284 ASSERT(!waitqueue_active(&state
->wq
));
285 free_extent_state(state
);
287 cond_resched_lock(&tree
->lock
);
289 spin_unlock(&tree
->lock
);
292 static struct extent_state
*alloc_extent_state(gfp_t mask
)
294 struct extent_state
*state
;
297 * The given mask might be not appropriate for the slab allocator,
298 * drop the unsupported bits
300 mask
&= ~(__GFP_DMA32
|__GFP_HIGHMEM
);
301 state
= kmem_cache_alloc(extent_state_cache
, mask
);
305 state
->failrec
= NULL
;
306 RB_CLEAR_NODE(&state
->rb_node
);
307 btrfs_leak_debug_add(&state
->leak_list
, &states
);
308 refcount_set(&state
->refs
, 1);
309 init_waitqueue_head(&state
->wq
);
310 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
314 void free_extent_state(struct extent_state
*state
)
318 if (refcount_dec_and_test(&state
->refs
)) {
319 WARN_ON(extent_state_in_tree(state
));
320 btrfs_leak_debug_del(&state
->leak_list
);
321 trace_free_extent_state(state
, _RET_IP_
);
322 kmem_cache_free(extent_state_cache
, state
);
326 static struct rb_node
*tree_insert(struct rb_root
*root
,
327 struct rb_node
*search_start
,
329 struct rb_node
*node
,
330 struct rb_node
***p_in
,
331 struct rb_node
**parent_in
)
334 struct rb_node
*parent
= NULL
;
335 struct tree_entry
*entry
;
337 if (p_in
&& parent_in
) {
343 p
= search_start
? &search_start
: &root
->rb_node
;
346 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
348 if (offset
< entry
->start
)
350 else if (offset
> entry
->end
)
357 rb_link_node(node
, parent
, p
);
358 rb_insert_color(node
, root
);
363 * __etree_search - searche @tree for an entry that contains @offset. Such
364 * entry would have entry->start <= offset && entry->end >= offset.
366 * @tree - the tree to search
367 * @offset - offset that should fall within an entry in @tree
368 * @next_ret - pointer to the first entry whose range ends after @offset
369 * @prev - pointer to the first entry whose range begins before @offset
370 * @p_ret - pointer where new node should be anchored (used when inserting an
372 * @parent_ret - points to entry which would have been the parent of the entry,
375 * This function returns a pointer to the entry that contains @offset byte
376 * address. If no such entry exists, then NULL is returned and the other
377 * pointer arguments to the function are filled, otherwise the found entry is
378 * returned and other pointers are left untouched.
380 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
381 struct rb_node
**next_ret
,
382 struct rb_node
**prev_ret
,
383 struct rb_node
***p_ret
,
384 struct rb_node
**parent_ret
)
386 struct rb_root
*root
= &tree
->state
;
387 struct rb_node
**n
= &root
->rb_node
;
388 struct rb_node
*prev
= NULL
;
389 struct rb_node
*orig_prev
= NULL
;
390 struct tree_entry
*entry
;
391 struct tree_entry
*prev_entry
= NULL
;
395 entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
398 if (offset
< entry
->start
)
400 else if (offset
> entry
->end
)
413 while (prev
&& offset
> prev_entry
->end
) {
414 prev
= rb_next(prev
);
415 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
422 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
423 while (prev
&& offset
< prev_entry
->start
) {
424 prev
= rb_prev(prev
);
425 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
432 static inline struct rb_node
*
433 tree_search_for_insert(struct extent_io_tree
*tree
,
435 struct rb_node
***p_ret
,
436 struct rb_node
**parent_ret
)
438 struct rb_node
*next
= NULL
;
441 ret
= __etree_search(tree
, offset
, &next
, NULL
, p_ret
, parent_ret
);
447 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
450 return tree_search_for_insert(tree
, offset
, NULL
, NULL
);
454 * utility function to look for merge candidates inside a given range.
455 * Any extents with matching state are merged together into a single
456 * extent in the tree. Extents with EXTENT_IO in their state field
457 * are not merged because the end_io handlers need to be able to do
458 * operations on them without sleeping (or doing allocations/splits).
460 * This should be called with the tree lock held.
462 static void merge_state(struct extent_io_tree
*tree
,
463 struct extent_state
*state
)
465 struct extent_state
*other
;
466 struct rb_node
*other_node
;
468 if (state
->state
& (EXTENT_LOCKED
| EXTENT_BOUNDARY
))
471 other_node
= rb_prev(&state
->rb_node
);
473 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
474 if (other
->end
== state
->start
- 1 &&
475 other
->state
== state
->state
) {
476 if (tree
->private_data
&&
477 is_data_inode(tree
->private_data
))
478 btrfs_merge_delalloc_extent(tree
->private_data
,
480 state
->start
= other
->start
;
481 rb_erase(&other
->rb_node
, &tree
->state
);
482 RB_CLEAR_NODE(&other
->rb_node
);
483 free_extent_state(other
);
486 other_node
= rb_next(&state
->rb_node
);
488 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
489 if (other
->start
== state
->end
+ 1 &&
490 other
->state
== state
->state
) {
491 if (tree
->private_data
&&
492 is_data_inode(tree
->private_data
))
493 btrfs_merge_delalloc_extent(tree
->private_data
,
495 state
->end
= other
->end
;
496 rb_erase(&other
->rb_node
, &tree
->state
);
497 RB_CLEAR_NODE(&other
->rb_node
);
498 free_extent_state(other
);
503 static void set_state_bits(struct extent_io_tree
*tree
,
504 struct extent_state
*state
, unsigned *bits
,
505 struct extent_changeset
*changeset
);
508 * insert an extent_state struct into the tree. 'bits' are set on the
509 * struct before it is inserted.
511 * This may return -EEXIST if the extent is already there, in which case the
512 * state struct is freed.
514 * The tree lock is not taken internally. This is a utility function and
515 * probably isn't what you want to call (see set/clear_extent_bit).
517 static int insert_state(struct extent_io_tree
*tree
,
518 struct extent_state
*state
, u64 start
, u64 end
,
520 struct rb_node
**parent
,
521 unsigned *bits
, struct extent_changeset
*changeset
)
523 struct rb_node
*node
;
526 btrfs_err(tree
->fs_info
,
527 "insert state: end < start %llu %llu", end
, start
);
530 state
->start
= start
;
533 set_state_bits(tree
, state
, bits
, changeset
);
535 node
= tree_insert(&tree
->state
, NULL
, end
, &state
->rb_node
, p
, parent
);
537 struct extent_state
*found
;
538 found
= rb_entry(node
, struct extent_state
, rb_node
);
539 btrfs_err(tree
->fs_info
,
540 "found node %llu %llu on insert of %llu %llu",
541 found
->start
, found
->end
, start
, end
);
544 merge_state(tree
, state
);
549 * split a given extent state struct in two, inserting the preallocated
550 * struct 'prealloc' as the newly created second half. 'split' indicates an
551 * offset inside 'orig' where it should be split.
554 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
555 * are two extent state structs in the tree:
556 * prealloc: [orig->start, split - 1]
557 * orig: [ split, orig->end ]
559 * The tree locks are not taken by this function. They need to be held
562 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
563 struct extent_state
*prealloc
, u64 split
)
565 struct rb_node
*node
;
567 if (tree
->private_data
&& is_data_inode(tree
->private_data
))
568 btrfs_split_delalloc_extent(tree
->private_data
, orig
, split
);
570 prealloc
->start
= orig
->start
;
571 prealloc
->end
= split
- 1;
572 prealloc
->state
= orig
->state
;
575 node
= tree_insert(&tree
->state
, &orig
->rb_node
, prealloc
->end
,
576 &prealloc
->rb_node
, NULL
, NULL
);
578 free_extent_state(prealloc
);
584 static struct extent_state
*next_state(struct extent_state
*state
)
586 struct rb_node
*next
= rb_next(&state
->rb_node
);
588 return rb_entry(next
, struct extent_state
, rb_node
);
594 * utility function to clear some bits in an extent state struct.
595 * it will optionally wake up anyone waiting on this state (wake == 1).
597 * If no bits are set on the state struct after clearing things, the
598 * struct is freed and removed from the tree
600 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
601 struct extent_state
*state
,
602 unsigned *bits
, int wake
,
603 struct extent_changeset
*changeset
)
605 struct extent_state
*next
;
606 unsigned bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
609 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
610 u64 range
= state
->end
- state
->start
+ 1;
611 WARN_ON(range
> tree
->dirty_bytes
);
612 tree
->dirty_bytes
-= range
;
615 if (tree
->private_data
&& is_data_inode(tree
->private_data
))
616 btrfs_clear_delalloc_extent(tree
->private_data
, state
, bits
);
618 ret
= add_extent_changeset(state
, bits_to_clear
, changeset
, 0);
620 state
->state
&= ~bits_to_clear
;
623 if (state
->state
== 0) {
624 next
= next_state(state
);
625 if (extent_state_in_tree(state
)) {
626 rb_erase(&state
->rb_node
, &tree
->state
);
627 RB_CLEAR_NODE(&state
->rb_node
);
628 free_extent_state(state
);
633 merge_state(tree
, state
);
634 next
= next_state(state
);
639 static struct extent_state
*
640 alloc_extent_state_atomic(struct extent_state
*prealloc
)
643 prealloc
= alloc_extent_state(GFP_ATOMIC
);
648 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
650 struct inode
*inode
= tree
->private_data
;
652 btrfs_panic(btrfs_sb(inode
->i_sb
), err
,
653 "locking error: extent tree was modified by another thread while locked");
657 * clear some bits on a range in the tree. This may require splitting
658 * or inserting elements in the tree, so the gfp mask is used to
659 * indicate which allocations or sleeping are allowed.
661 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
662 * the given range from the tree regardless of state (ie for truncate).
664 * the range [start, end] is inclusive.
666 * This takes the tree lock, and returns 0 on success and < 0 on error.
668 int __clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
669 unsigned bits
, int wake
, int delete,
670 struct extent_state
**cached_state
,
671 gfp_t mask
, struct extent_changeset
*changeset
)
673 struct extent_state
*state
;
674 struct extent_state
*cached
;
675 struct extent_state
*prealloc
= NULL
;
676 struct rb_node
*node
;
681 btrfs_debug_check_extent_io_range(tree
, start
, end
);
682 trace_btrfs_clear_extent_bit(tree
, start
, end
- start
+ 1, bits
);
684 if (bits
& EXTENT_DELALLOC
)
685 bits
|= EXTENT_NORESERVE
;
688 bits
|= ~EXTENT_CTLBITS
;
690 if (bits
& (EXTENT_LOCKED
| EXTENT_BOUNDARY
))
693 if (!prealloc
&& gfpflags_allow_blocking(mask
)) {
695 * Don't care for allocation failure here because we might end
696 * up not needing the pre-allocated extent state at all, which
697 * is the case if we only have in the tree extent states that
698 * cover our input range and don't cover too any other range.
699 * If we end up needing a new extent state we allocate it later.
701 prealloc
= alloc_extent_state(mask
);
704 spin_lock(&tree
->lock
);
706 cached
= *cached_state
;
709 *cached_state
= NULL
;
713 if (cached
&& extent_state_in_tree(cached
) &&
714 cached
->start
<= start
&& cached
->end
> start
) {
716 refcount_dec(&cached
->refs
);
721 free_extent_state(cached
);
724 * this search will find the extents that end after
727 node
= tree_search(tree
, start
);
730 state
= rb_entry(node
, struct extent_state
, rb_node
);
732 if (state
->start
> end
)
734 WARN_ON(state
->end
< start
);
735 last_end
= state
->end
;
737 /* the state doesn't have the wanted bits, go ahead */
738 if (!(state
->state
& bits
)) {
739 state
= next_state(state
);
744 * | ---- desired range ---- |
746 * | ------------- state -------------- |
748 * We need to split the extent we found, and may flip
749 * bits on second half.
751 * If the extent we found extends past our range, we
752 * just split and search again. It'll get split again
753 * the next time though.
755 * If the extent we found is inside our range, we clear
756 * the desired bit on it.
759 if (state
->start
< start
) {
760 prealloc
= alloc_extent_state_atomic(prealloc
);
762 err
= split_state(tree
, state
, prealloc
, start
);
764 extent_io_tree_panic(tree
, err
);
769 if (state
->end
<= end
) {
770 state
= clear_state_bit(tree
, state
, &bits
, wake
,
777 * | ---- desired range ---- |
779 * We need to split the extent, and clear the bit
782 if (state
->start
<= end
&& state
->end
> end
) {
783 prealloc
= alloc_extent_state_atomic(prealloc
);
785 err
= split_state(tree
, state
, prealloc
, end
+ 1);
787 extent_io_tree_panic(tree
, err
);
792 clear_state_bit(tree
, prealloc
, &bits
, wake
, changeset
);
798 state
= clear_state_bit(tree
, state
, &bits
, wake
, changeset
);
800 if (last_end
== (u64
)-1)
802 start
= last_end
+ 1;
803 if (start
<= end
&& state
&& !need_resched())
809 spin_unlock(&tree
->lock
);
810 if (gfpflags_allow_blocking(mask
))
815 spin_unlock(&tree
->lock
);
817 free_extent_state(prealloc
);
823 static void wait_on_state(struct extent_io_tree
*tree
,
824 struct extent_state
*state
)
825 __releases(tree
->lock
)
826 __acquires(tree
->lock
)
829 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
830 spin_unlock(&tree
->lock
);
832 spin_lock(&tree
->lock
);
833 finish_wait(&state
->wq
, &wait
);
837 * waits for one or more bits to clear on a range in the state tree.
838 * The range [start, end] is inclusive.
839 * The tree lock is taken by this function
841 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
844 struct extent_state
*state
;
845 struct rb_node
*node
;
847 btrfs_debug_check_extent_io_range(tree
, start
, end
);
849 spin_lock(&tree
->lock
);
853 * this search will find all the extents that end after
856 node
= tree_search(tree
, start
);
861 state
= rb_entry(node
, struct extent_state
, rb_node
);
863 if (state
->start
> end
)
866 if (state
->state
& bits
) {
867 start
= state
->start
;
868 refcount_inc(&state
->refs
);
869 wait_on_state(tree
, state
);
870 free_extent_state(state
);
873 start
= state
->end
+ 1;
878 if (!cond_resched_lock(&tree
->lock
)) {
879 node
= rb_next(node
);
884 spin_unlock(&tree
->lock
);
887 static void set_state_bits(struct extent_io_tree
*tree
,
888 struct extent_state
*state
,
889 unsigned *bits
, struct extent_changeset
*changeset
)
891 unsigned bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
894 if (tree
->private_data
&& is_data_inode(tree
->private_data
))
895 btrfs_set_delalloc_extent(tree
->private_data
, state
, bits
);
897 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
898 u64 range
= state
->end
- state
->start
+ 1;
899 tree
->dirty_bytes
+= range
;
901 ret
= add_extent_changeset(state
, bits_to_set
, changeset
, 1);
903 state
->state
|= bits_to_set
;
906 static void cache_state_if_flags(struct extent_state
*state
,
907 struct extent_state
**cached_ptr
,
910 if (cached_ptr
&& !(*cached_ptr
)) {
911 if (!flags
|| (state
->state
& flags
)) {
913 refcount_inc(&state
->refs
);
918 static void cache_state(struct extent_state
*state
,
919 struct extent_state
**cached_ptr
)
921 return cache_state_if_flags(state
, cached_ptr
,
922 EXTENT_LOCKED
| EXTENT_BOUNDARY
);
926 * set some bits on a range in the tree. This may require allocations or
927 * sleeping, so the gfp mask is used to indicate what is allowed.
929 * If any of the exclusive bits are set, this will fail with -EEXIST if some
930 * part of the range already has the desired bits set. The start of the
931 * existing range is returned in failed_start in this case.
933 * [start, end] is inclusive This takes the tree lock.
936 static int __must_check
937 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
938 unsigned bits
, unsigned exclusive_bits
,
939 u64
*failed_start
, struct extent_state
**cached_state
,
940 gfp_t mask
, struct extent_changeset
*changeset
)
942 struct extent_state
*state
;
943 struct extent_state
*prealloc
= NULL
;
944 struct rb_node
*node
;
946 struct rb_node
*parent
;
951 btrfs_debug_check_extent_io_range(tree
, start
, end
);
952 trace_btrfs_set_extent_bit(tree
, start
, end
- start
+ 1, bits
);
955 if (!prealloc
&& gfpflags_allow_blocking(mask
)) {
957 * Don't care for allocation failure here because we might end
958 * up not needing the pre-allocated extent state at all, which
959 * is the case if we only have in the tree extent states that
960 * cover our input range and don't cover too any other range.
961 * If we end up needing a new extent state we allocate it later.
963 prealloc
= alloc_extent_state(mask
);
966 spin_lock(&tree
->lock
);
967 if (cached_state
&& *cached_state
) {
968 state
= *cached_state
;
969 if (state
->start
<= start
&& state
->end
> start
&&
970 extent_state_in_tree(state
)) {
971 node
= &state
->rb_node
;
976 * this search will find all the extents that end after
979 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
981 prealloc
= alloc_extent_state_atomic(prealloc
);
983 err
= insert_state(tree
, prealloc
, start
, end
,
984 &p
, &parent
, &bits
, changeset
);
986 extent_io_tree_panic(tree
, err
);
988 cache_state(prealloc
, cached_state
);
992 state
= rb_entry(node
, struct extent_state
, rb_node
);
994 last_start
= state
->start
;
995 last_end
= state
->end
;
998 * | ---- desired range ---- |
1001 * Just lock what we found and keep going
1003 if (state
->start
== start
&& state
->end
<= end
) {
1004 if (state
->state
& exclusive_bits
) {
1005 *failed_start
= state
->start
;
1010 set_state_bits(tree
, state
, &bits
, changeset
);
1011 cache_state(state
, cached_state
);
1012 merge_state(tree
, state
);
1013 if (last_end
== (u64
)-1)
1015 start
= last_end
+ 1;
1016 state
= next_state(state
);
1017 if (start
< end
&& state
&& state
->start
== start
&&
1024 * | ---- desired range ---- |
1027 * | ------------- state -------------- |
1029 * We need to split the extent we found, and may flip bits on
1032 * If the extent we found extends past our
1033 * range, we just split and search again. It'll get split
1034 * again the next time though.
1036 * If the extent we found is inside our range, we set the
1037 * desired bit on it.
1039 if (state
->start
< start
) {
1040 if (state
->state
& exclusive_bits
) {
1041 *failed_start
= start
;
1046 prealloc
= alloc_extent_state_atomic(prealloc
);
1048 err
= split_state(tree
, state
, prealloc
, start
);
1050 extent_io_tree_panic(tree
, err
);
1055 if (state
->end
<= end
) {
1056 set_state_bits(tree
, state
, &bits
, changeset
);
1057 cache_state(state
, cached_state
);
1058 merge_state(tree
, state
);
1059 if (last_end
== (u64
)-1)
1061 start
= last_end
+ 1;
1062 state
= next_state(state
);
1063 if (start
< end
&& state
&& state
->start
== start
&&
1070 * | ---- desired range ---- |
1071 * | state | or | state |
1073 * There's a hole, we need to insert something in it and
1074 * ignore the extent we found.
1076 if (state
->start
> start
) {
1078 if (end
< last_start
)
1081 this_end
= last_start
- 1;
1083 prealloc
= alloc_extent_state_atomic(prealloc
);
1087 * Avoid to free 'prealloc' if it can be merged with
1090 err
= insert_state(tree
, prealloc
, start
, this_end
,
1091 NULL
, NULL
, &bits
, changeset
);
1093 extent_io_tree_panic(tree
, err
);
1095 cache_state(prealloc
, cached_state
);
1097 start
= this_end
+ 1;
1101 * | ---- desired range ---- |
1103 * We need to split the extent, and set the bit
1106 if (state
->start
<= end
&& state
->end
> end
) {
1107 if (state
->state
& exclusive_bits
) {
1108 *failed_start
= start
;
1113 prealloc
= alloc_extent_state_atomic(prealloc
);
1115 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1117 extent_io_tree_panic(tree
, err
);
1119 set_state_bits(tree
, prealloc
, &bits
, changeset
);
1120 cache_state(prealloc
, cached_state
);
1121 merge_state(tree
, prealloc
);
1129 spin_unlock(&tree
->lock
);
1130 if (gfpflags_allow_blocking(mask
))
1135 spin_unlock(&tree
->lock
);
1137 free_extent_state(prealloc
);
1143 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1144 unsigned bits
, u64
* failed_start
,
1145 struct extent_state
**cached_state
, gfp_t mask
)
1147 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
1148 cached_state
, mask
, NULL
);
1153 * convert_extent_bit - convert all bits in a given range from one bit to
1155 * @tree: the io tree to search
1156 * @start: the start offset in bytes
1157 * @end: the end offset in bytes (inclusive)
1158 * @bits: the bits to set in this range
1159 * @clear_bits: the bits to clear in this range
1160 * @cached_state: state that we're going to cache
1162 * This will go through and set bits for the given range. If any states exist
1163 * already in this range they are set with the given bit and cleared of the
1164 * clear_bits. This is only meant to be used by things that are mergeable, ie
1165 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1166 * boundary bits like LOCK.
1168 * All allocations are done with GFP_NOFS.
1170 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1171 unsigned bits
, unsigned clear_bits
,
1172 struct extent_state
**cached_state
)
1174 struct extent_state
*state
;
1175 struct extent_state
*prealloc
= NULL
;
1176 struct rb_node
*node
;
1178 struct rb_node
*parent
;
1182 bool first_iteration
= true;
1184 btrfs_debug_check_extent_io_range(tree
, start
, end
);
1185 trace_btrfs_convert_extent_bit(tree
, start
, end
- start
+ 1, bits
,
1191 * Best effort, don't worry if extent state allocation fails
1192 * here for the first iteration. We might have a cached state
1193 * that matches exactly the target range, in which case no
1194 * extent state allocations are needed. We'll only know this
1195 * after locking the tree.
1197 prealloc
= alloc_extent_state(GFP_NOFS
);
1198 if (!prealloc
&& !first_iteration
)
1202 spin_lock(&tree
->lock
);
1203 if (cached_state
&& *cached_state
) {
1204 state
= *cached_state
;
1205 if (state
->start
<= start
&& state
->end
> start
&&
1206 extent_state_in_tree(state
)) {
1207 node
= &state
->rb_node
;
1213 * this search will find all the extents that end after
1216 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
1218 prealloc
= alloc_extent_state_atomic(prealloc
);
1223 err
= insert_state(tree
, prealloc
, start
, end
,
1224 &p
, &parent
, &bits
, NULL
);
1226 extent_io_tree_panic(tree
, err
);
1227 cache_state(prealloc
, cached_state
);
1231 state
= rb_entry(node
, struct extent_state
, rb_node
);
1233 last_start
= state
->start
;
1234 last_end
= state
->end
;
1237 * | ---- desired range ---- |
1240 * Just lock what we found and keep going
1242 if (state
->start
== start
&& state
->end
<= end
) {
1243 set_state_bits(tree
, state
, &bits
, NULL
);
1244 cache_state(state
, cached_state
);
1245 state
= clear_state_bit(tree
, state
, &clear_bits
, 0, NULL
);
1246 if (last_end
== (u64
)-1)
1248 start
= last_end
+ 1;
1249 if (start
< end
&& state
&& state
->start
== start
&&
1256 * | ---- desired range ---- |
1259 * | ------------- state -------------- |
1261 * We need to split the extent we found, and may flip bits on
1264 * If the extent we found extends past our
1265 * range, we just split and search again. It'll get split
1266 * again the next time though.
1268 * If the extent we found is inside our range, we set the
1269 * desired bit on it.
1271 if (state
->start
< start
) {
1272 prealloc
= alloc_extent_state_atomic(prealloc
);
1277 err
= split_state(tree
, state
, prealloc
, start
);
1279 extent_io_tree_panic(tree
, err
);
1283 if (state
->end
<= end
) {
1284 set_state_bits(tree
, state
, &bits
, NULL
);
1285 cache_state(state
, cached_state
);
1286 state
= clear_state_bit(tree
, state
, &clear_bits
, 0,
1288 if (last_end
== (u64
)-1)
1290 start
= last_end
+ 1;
1291 if (start
< end
&& state
&& state
->start
== start
&&
1298 * | ---- desired range ---- |
1299 * | state | or | state |
1301 * There's a hole, we need to insert something in it and
1302 * ignore the extent we found.
1304 if (state
->start
> start
) {
1306 if (end
< last_start
)
1309 this_end
= last_start
- 1;
1311 prealloc
= alloc_extent_state_atomic(prealloc
);
1318 * Avoid to free 'prealloc' if it can be merged with
1321 err
= insert_state(tree
, prealloc
, start
, this_end
,
1322 NULL
, NULL
, &bits
, NULL
);
1324 extent_io_tree_panic(tree
, err
);
1325 cache_state(prealloc
, cached_state
);
1327 start
= this_end
+ 1;
1331 * | ---- desired range ---- |
1333 * We need to split the extent, and set the bit
1336 if (state
->start
<= end
&& state
->end
> end
) {
1337 prealloc
= alloc_extent_state_atomic(prealloc
);
1343 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1345 extent_io_tree_panic(tree
, err
);
1347 set_state_bits(tree
, prealloc
, &bits
, NULL
);
1348 cache_state(prealloc
, cached_state
);
1349 clear_state_bit(tree
, prealloc
, &clear_bits
, 0, NULL
);
1357 spin_unlock(&tree
->lock
);
1359 first_iteration
= false;
1363 spin_unlock(&tree
->lock
);
1365 free_extent_state(prealloc
);
1370 /* wrappers around set/clear extent bit */
1371 int set_record_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1372 unsigned bits
, struct extent_changeset
*changeset
)
1375 * We don't support EXTENT_LOCKED yet, as current changeset will
1376 * record any bits changed, so for EXTENT_LOCKED case, it will
1377 * either fail with -EEXIST or changeset will record the whole
1380 BUG_ON(bits
& EXTENT_LOCKED
);
1382 return __set_extent_bit(tree
, start
, end
, bits
, 0, NULL
, NULL
, GFP_NOFS
,
1386 int set_extent_bits_nowait(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1389 return __set_extent_bit(tree
, start
, end
, bits
, 0, NULL
, NULL
,
1393 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1394 unsigned bits
, int wake
, int delete,
1395 struct extent_state
**cached
)
1397 return __clear_extent_bit(tree
, start
, end
, bits
, wake
, delete,
1398 cached
, GFP_NOFS
, NULL
);
1401 int clear_record_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1402 unsigned bits
, struct extent_changeset
*changeset
)
1405 * Don't support EXTENT_LOCKED case, same reason as
1406 * set_record_extent_bits().
1408 BUG_ON(bits
& EXTENT_LOCKED
);
1410 return __clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, GFP_NOFS
,
1415 * either insert or lock state struct between start and end use mask to tell
1416 * us if waiting is desired.
1418 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1419 struct extent_state
**cached_state
)
1425 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
,
1426 EXTENT_LOCKED
, &failed_start
,
1427 cached_state
, GFP_NOFS
, NULL
);
1428 if (err
== -EEXIST
) {
1429 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1430 start
= failed_start
;
1433 WARN_ON(start
> end
);
1438 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1443 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1444 &failed_start
, NULL
, GFP_NOFS
, NULL
);
1445 if (err
== -EEXIST
) {
1446 if (failed_start
> start
)
1447 clear_extent_bit(tree
, start
, failed_start
- 1,
1448 EXTENT_LOCKED
, 1, 0, NULL
);
1454 void extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1456 unsigned long index
= start
>> PAGE_SHIFT
;
1457 unsigned long end_index
= end
>> PAGE_SHIFT
;
1460 while (index
<= end_index
) {
1461 page
= find_get_page(inode
->i_mapping
, index
);
1462 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1463 clear_page_dirty_for_io(page
);
1469 void extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1471 unsigned long index
= start
>> PAGE_SHIFT
;
1472 unsigned long end_index
= end
>> PAGE_SHIFT
;
1475 while (index
<= end_index
) {
1476 page
= find_get_page(inode
->i_mapping
, index
);
1477 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1478 __set_page_dirty_nobuffers(page
);
1479 account_page_redirty(page
);
1485 /* find the first state struct with 'bits' set after 'start', and
1486 * return it. tree->lock must be held. NULL will returned if
1487 * nothing was found after 'start'
1489 static struct extent_state
*
1490 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1491 u64 start
, unsigned bits
)
1493 struct rb_node
*node
;
1494 struct extent_state
*state
;
1497 * this search will find all the extents that end after
1500 node
= tree_search(tree
, start
);
1505 state
= rb_entry(node
, struct extent_state
, rb_node
);
1506 if (state
->end
>= start
&& (state
->state
& bits
))
1509 node
= rb_next(node
);
1518 * find the first offset in the io tree with 'bits' set. zero is
1519 * returned if we find something, and *start_ret and *end_ret are
1520 * set to reflect the state struct that was found.
1522 * If nothing was found, 1 is returned. If found something, return 0.
1524 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1525 u64
*start_ret
, u64
*end_ret
, unsigned bits
,
1526 struct extent_state
**cached_state
)
1528 struct extent_state
*state
;
1531 spin_lock(&tree
->lock
);
1532 if (cached_state
&& *cached_state
) {
1533 state
= *cached_state
;
1534 if (state
->end
== start
- 1 && extent_state_in_tree(state
)) {
1535 while ((state
= next_state(state
)) != NULL
) {
1536 if (state
->state
& bits
)
1539 free_extent_state(*cached_state
);
1540 *cached_state
= NULL
;
1543 free_extent_state(*cached_state
);
1544 *cached_state
= NULL
;
1547 state
= find_first_extent_bit_state(tree
, start
, bits
);
1550 cache_state_if_flags(state
, cached_state
, 0);
1551 *start_ret
= state
->start
;
1552 *end_ret
= state
->end
;
1556 spin_unlock(&tree
->lock
);
1561 * find_first_clear_extent_bit - find the first range that has @bits not set.
1562 * This range could start before @start.
1564 * @tree - the tree to search
1565 * @start - the offset at/after which the found extent should start
1566 * @start_ret - records the beginning of the range
1567 * @end_ret - records the end of the range (inclusive)
1568 * @bits - the set of bits which must be unset
1570 * Since unallocated range is also considered one which doesn't have the bits
1571 * set it's possible that @end_ret contains -1, this happens in case the range
1572 * spans (last_range_end, end of device]. In this case it's up to the caller to
1573 * trim @end_ret to the appropriate size.
1575 void find_first_clear_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1576 u64
*start_ret
, u64
*end_ret
, unsigned bits
)
1578 struct extent_state
*state
;
1579 struct rb_node
*node
, *prev
= NULL
, *next
;
1581 spin_lock(&tree
->lock
);
1583 /* Find first extent with bits cleared */
1585 node
= __etree_search(tree
, start
, &next
, &prev
, NULL
, NULL
);
1590 * We are past the last allocated chunk,
1591 * set start at the end of the last extent. The
1592 * device alloc tree should never be empty so
1593 * prev is always set.
1596 state
= rb_entry(prev
, struct extent_state
, rb_node
);
1597 *start_ret
= state
->end
+ 1;
1603 * At this point 'node' either contains 'start' or start is
1606 state
= rb_entry(node
, struct extent_state
, rb_node
);
1608 if (in_range(start
, state
->start
, state
->end
- state
->start
+ 1)) {
1609 if (state
->state
& bits
) {
1611 * |--range with bits sets--|
1615 start
= state
->end
+ 1;
1618 * 'start' falls within a range that doesn't
1619 * have the bits set, so take its start as
1620 * the beginning of the desired range
1622 * |--range with bits cleared----|
1626 *start_ret
= state
->start
;
1631 * |---prev range---|---hole/unset---|---node range---|
1637 * |---hole/unset--||--first node--|
1642 state
= rb_entry(prev
, struct extent_state
,
1644 *start_ret
= state
->end
+ 1;
1653 * Find the longest stretch from start until an entry which has the
1657 state
= rb_entry(node
, struct extent_state
, rb_node
);
1658 if (state
->end
>= start
&& !(state
->state
& bits
)) {
1659 *end_ret
= state
->end
;
1661 *end_ret
= state
->start
- 1;
1665 node
= rb_next(node
);
1670 spin_unlock(&tree
->lock
);
1674 * find a contiguous range of bytes in the file marked as delalloc, not
1675 * more than 'max_bytes'. start and end are used to return the range,
1677 * true is returned if we find something, false if nothing was in the tree
1679 static noinline
bool find_delalloc_range(struct extent_io_tree
*tree
,
1680 u64
*start
, u64
*end
, u64 max_bytes
,
1681 struct extent_state
**cached_state
)
1683 struct rb_node
*node
;
1684 struct extent_state
*state
;
1685 u64 cur_start
= *start
;
1687 u64 total_bytes
= 0;
1689 spin_lock(&tree
->lock
);
1692 * this search will find all the extents that end after
1695 node
= tree_search(tree
, cur_start
);
1702 state
= rb_entry(node
, struct extent_state
, rb_node
);
1703 if (found
&& (state
->start
!= cur_start
||
1704 (state
->state
& EXTENT_BOUNDARY
))) {
1707 if (!(state
->state
& EXTENT_DELALLOC
)) {
1713 *start
= state
->start
;
1714 *cached_state
= state
;
1715 refcount_inc(&state
->refs
);
1719 cur_start
= state
->end
+ 1;
1720 node
= rb_next(node
);
1721 total_bytes
+= state
->end
- state
->start
+ 1;
1722 if (total_bytes
>= max_bytes
)
1728 spin_unlock(&tree
->lock
);
1732 static int __process_pages_contig(struct address_space
*mapping
,
1733 struct page
*locked_page
,
1734 pgoff_t start_index
, pgoff_t end_index
,
1735 unsigned long page_ops
, pgoff_t
*index_ret
);
1737 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1738 struct page
*locked_page
,
1741 unsigned long index
= start
>> PAGE_SHIFT
;
1742 unsigned long end_index
= end
>> PAGE_SHIFT
;
1744 ASSERT(locked_page
);
1745 if (index
== locked_page
->index
&& end_index
== index
)
1748 __process_pages_contig(inode
->i_mapping
, locked_page
, index
, end_index
,
1752 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1753 struct page
*locked_page
,
1757 unsigned long index
= delalloc_start
>> PAGE_SHIFT
;
1758 unsigned long index_ret
= index
;
1759 unsigned long end_index
= delalloc_end
>> PAGE_SHIFT
;
1762 ASSERT(locked_page
);
1763 if (index
== locked_page
->index
&& index
== end_index
)
1766 ret
= __process_pages_contig(inode
->i_mapping
, locked_page
, index
,
1767 end_index
, PAGE_LOCK
, &index_ret
);
1769 __unlock_for_delalloc(inode
, locked_page
, delalloc_start
,
1770 (u64
)index_ret
<< PAGE_SHIFT
);
1775 * Find and lock a contiguous range of bytes in the file marked as delalloc, no
1776 * more than @max_bytes. @Start and @end are used to return the range,
1778 * Return: true if we find something
1779 * false if nothing was in the tree
1782 noinline_for_stack
bool find_lock_delalloc_range(struct inode
*inode
,
1783 struct page
*locked_page
, u64
*start
,
1786 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
1787 u64 max_bytes
= BTRFS_MAX_EXTENT_SIZE
;
1791 struct extent_state
*cached_state
= NULL
;
1796 /* step one, find a bunch of delalloc bytes starting at start */
1797 delalloc_start
= *start
;
1799 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1800 max_bytes
, &cached_state
);
1801 if (!found
|| delalloc_end
<= *start
) {
1802 *start
= delalloc_start
;
1803 *end
= delalloc_end
;
1804 free_extent_state(cached_state
);
1809 * start comes from the offset of locked_page. We have to lock
1810 * pages in order, so we can't process delalloc bytes before
1813 if (delalloc_start
< *start
)
1814 delalloc_start
= *start
;
1817 * make sure to limit the number of pages we try to lock down
1819 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
)
1820 delalloc_end
= delalloc_start
+ max_bytes
- 1;
1822 /* step two, lock all the pages after the page that has start */
1823 ret
= lock_delalloc_pages(inode
, locked_page
,
1824 delalloc_start
, delalloc_end
);
1825 ASSERT(!ret
|| ret
== -EAGAIN
);
1826 if (ret
== -EAGAIN
) {
1827 /* some of the pages are gone, lets avoid looping by
1828 * shortening the size of the delalloc range we're searching
1830 free_extent_state(cached_state
);
1831 cached_state
= NULL
;
1833 max_bytes
= PAGE_SIZE
;
1842 /* step three, lock the state bits for the whole range */
1843 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, &cached_state
);
1845 /* then test to make sure it is all still delalloc */
1846 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1847 EXTENT_DELALLOC
, 1, cached_state
);
1849 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1851 __unlock_for_delalloc(inode
, locked_page
,
1852 delalloc_start
, delalloc_end
);
1856 free_extent_state(cached_state
);
1857 *start
= delalloc_start
;
1858 *end
= delalloc_end
;
1863 static int __process_pages_contig(struct address_space
*mapping
,
1864 struct page
*locked_page
,
1865 pgoff_t start_index
, pgoff_t end_index
,
1866 unsigned long page_ops
, pgoff_t
*index_ret
)
1868 unsigned long nr_pages
= end_index
- start_index
+ 1;
1869 unsigned long pages_locked
= 0;
1870 pgoff_t index
= start_index
;
1871 struct page
*pages
[16];
1876 if (page_ops
& PAGE_LOCK
) {
1877 ASSERT(page_ops
== PAGE_LOCK
);
1878 ASSERT(index_ret
&& *index_ret
== start_index
);
1881 if ((page_ops
& PAGE_SET_ERROR
) && nr_pages
> 0)
1882 mapping_set_error(mapping
, -EIO
);
1884 while (nr_pages
> 0) {
1885 ret
= find_get_pages_contig(mapping
, index
,
1886 min_t(unsigned long,
1887 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1890 * Only if we're going to lock these pages,
1891 * can we find nothing at @index.
1893 ASSERT(page_ops
& PAGE_LOCK
);
1898 for (i
= 0; i
< ret
; i
++) {
1899 if (page_ops
& PAGE_SET_PRIVATE2
)
1900 SetPagePrivate2(pages
[i
]);
1902 if (pages
[i
] == locked_page
) {
1907 if (page_ops
& PAGE_CLEAR_DIRTY
)
1908 clear_page_dirty_for_io(pages
[i
]);
1909 if (page_ops
& PAGE_SET_WRITEBACK
)
1910 set_page_writeback(pages
[i
]);
1911 if (page_ops
& PAGE_SET_ERROR
)
1912 SetPageError(pages
[i
]);
1913 if (page_ops
& PAGE_END_WRITEBACK
)
1914 end_page_writeback(pages
[i
]);
1915 if (page_ops
& PAGE_UNLOCK
)
1916 unlock_page(pages
[i
]);
1917 if (page_ops
& PAGE_LOCK
) {
1918 lock_page(pages
[i
]);
1919 if (!PageDirty(pages
[i
]) ||
1920 pages
[i
]->mapping
!= mapping
) {
1921 unlock_page(pages
[i
]);
1935 if (err
&& index_ret
)
1936 *index_ret
= start_index
+ pages_locked
- 1;
1940 void extent_clear_unlock_delalloc(struct inode
*inode
, u64 start
, u64 end
,
1941 u64 delalloc_end
, struct page
*locked_page
,
1942 unsigned clear_bits
,
1943 unsigned long page_ops
)
1945 clear_extent_bit(&BTRFS_I(inode
)->io_tree
, start
, end
, clear_bits
, 1, 0,
1948 __process_pages_contig(inode
->i_mapping
, locked_page
,
1949 start
>> PAGE_SHIFT
, end
>> PAGE_SHIFT
,
1954 * count the number of bytes in the tree that have a given bit(s)
1955 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1956 * cached. The total number found is returned.
1958 u64
count_range_bits(struct extent_io_tree
*tree
,
1959 u64
*start
, u64 search_end
, u64 max_bytes
,
1960 unsigned bits
, int contig
)
1962 struct rb_node
*node
;
1963 struct extent_state
*state
;
1964 u64 cur_start
= *start
;
1965 u64 total_bytes
= 0;
1969 if (WARN_ON(search_end
<= cur_start
))
1972 spin_lock(&tree
->lock
);
1973 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1974 total_bytes
= tree
->dirty_bytes
;
1978 * this search will find all the extents that end after
1981 node
= tree_search(tree
, cur_start
);
1986 state
= rb_entry(node
, struct extent_state
, rb_node
);
1987 if (state
->start
> search_end
)
1989 if (contig
&& found
&& state
->start
> last
+ 1)
1991 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1992 total_bytes
+= min(search_end
, state
->end
) + 1 -
1993 max(cur_start
, state
->start
);
1994 if (total_bytes
>= max_bytes
)
1997 *start
= max(cur_start
, state
->start
);
2001 } else if (contig
&& found
) {
2004 node
= rb_next(node
);
2009 spin_unlock(&tree
->lock
);
2014 * set the private field for a given byte offset in the tree. If there isn't
2015 * an extent_state there already, this does nothing.
2017 static noinline
int set_state_failrec(struct extent_io_tree
*tree
, u64 start
,
2018 struct io_failure_record
*failrec
)
2020 struct rb_node
*node
;
2021 struct extent_state
*state
;
2024 spin_lock(&tree
->lock
);
2026 * this search will find all the extents that end after
2029 node
= tree_search(tree
, start
);
2034 state
= rb_entry(node
, struct extent_state
, rb_node
);
2035 if (state
->start
!= start
) {
2039 state
->failrec
= failrec
;
2041 spin_unlock(&tree
->lock
);
2045 static noinline
int get_state_failrec(struct extent_io_tree
*tree
, u64 start
,
2046 struct io_failure_record
**failrec
)
2048 struct rb_node
*node
;
2049 struct extent_state
*state
;
2052 spin_lock(&tree
->lock
);
2054 * this search will find all the extents that end after
2057 node
= tree_search(tree
, start
);
2062 state
= rb_entry(node
, struct extent_state
, rb_node
);
2063 if (state
->start
!= start
) {
2067 *failrec
= state
->failrec
;
2069 spin_unlock(&tree
->lock
);
2074 * searches a range in the state tree for a given mask.
2075 * If 'filled' == 1, this returns 1 only if every extent in the tree
2076 * has the bits set. Otherwise, 1 is returned if any bit in the
2077 * range is found set.
2079 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
2080 unsigned bits
, int filled
, struct extent_state
*cached
)
2082 struct extent_state
*state
= NULL
;
2083 struct rb_node
*node
;
2086 spin_lock(&tree
->lock
);
2087 if (cached
&& extent_state_in_tree(cached
) && cached
->start
<= start
&&
2088 cached
->end
> start
)
2089 node
= &cached
->rb_node
;
2091 node
= tree_search(tree
, start
);
2092 while (node
&& start
<= end
) {
2093 state
= rb_entry(node
, struct extent_state
, rb_node
);
2095 if (filled
&& state
->start
> start
) {
2100 if (state
->start
> end
)
2103 if (state
->state
& bits
) {
2107 } else if (filled
) {
2112 if (state
->end
== (u64
)-1)
2115 start
= state
->end
+ 1;
2118 node
= rb_next(node
);
2125 spin_unlock(&tree
->lock
);
2130 * helper function to set a given page up to date if all the
2131 * extents in the tree for that page are up to date
2133 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
2135 u64 start
= page_offset(page
);
2136 u64 end
= start
+ PAGE_SIZE
- 1;
2137 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
2138 SetPageUptodate(page
);
2141 int free_io_failure(struct extent_io_tree
*failure_tree
,
2142 struct extent_io_tree
*io_tree
,
2143 struct io_failure_record
*rec
)
2148 set_state_failrec(failure_tree
, rec
->start
, NULL
);
2149 ret
= clear_extent_bits(failure_tree
, rec
->start
,
2150 rec
->start
+ rec
->len
- 1,
2151 EXTENT_LOCKED
| EXTENT_DIRTY
);
2155 ret
= clear_extent_bits(io_tree
, rec
->start
,
2156 rec
->start
+ rec
->len
- 1,
2166 * this bypasses the standard btrfs submit functions deliberately, as
2167 * the standard behavior is to write all copies in a raid setup. here we only
2168 * want to write the one bad copy. so we do the mapping for ourselves and issue
2169 * submit_bio directly.
2170 * to avoid any synchronization issues, wait for the data after writing, which
2171 * actually prevents the read that triggered the error from finishing.
2172 * currently, there can be no more than two copies of every data bit. thus,
2173 * exactly one rewrite is required.
2175 int repair_io_failure(struct btrfs_fs_info
*fs_info
, u64 ino
, u64 start
,
2176 u64 length
, u64 logical
, struct page
*page
,
2177 unsigned int pg_offset
, int mirror_num
)
2180 struct btrfs_device
*dev
;
2183 struct btrfs_bio
*bbio
= NULL
;
2186 ASSERT(!(fs_info
->sb
->s_flags
& SB_RDONLY
));
2187 BUG_ON(!mirror_num
);
2189 bio
= btrfs_io_bio_alloc(1);
2190 bio
->bi_iter
.bi_size
= 0;
2191 map_length
= length
;
2194 * Avoid races with device replace and make sure our bbio has devices
2195 * associated to its stripes that don't go away while we are doing the
2196 * read repair operation.
2198 btrfs_bio_counter_inc_blocked(fs_info
);
2199 if (btrfs_is_parity_mirror(fs_info
, logical
, length
)) {
2201 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
2202 * to update all raid stripes, but here we just want to correct
2203 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
2204 * stripe's dev and sector.
2206 ret
= btrfs_map_block(fs_info
, BTRFS_MAP_READ
, logical
,
2207 &map_length
, &bbio
, 0);
2209 btrfs_bio_counter_dec(fs_info
);
2213 ASSERT(bbio
->mirror_num
== 1);
2215 ret
= btrfs_map_block(fs_info
, BTRFS_MAP_WRITE
, logical
,
2216 &map_length
, &bbio
, mirror_num
);
2218 btrfs_bio_counter_dec(fs_info
);
2222 BUG_ON(mirror_num
!= bbio
->mirror_num
);
2225 sector
= bbio
->stripes
[bbio
->mirror_num
- 1].physical
>> 9;
2226 bio
->bi_iter
.bi_sector
= sector
;
2227 dev
= bbio
->stripes
[bbio
->mirror_num
- 1].dev
;
2228 btrfs_put_bbio(bbio
);
2229 if (!dev
|| !dev
->bdev
||
2230 !test_bit(BTRFS_DEV_STATE_WRITEABLE
, &dev
->dev_state
)) {
2231 btrfs_bio_counter_dec(fs_info
);
2235 bio_set_dev(bio
, dev
->bdev
);
2236 bio
->bi_opf
= REQ_OP_WRITE
| REQ_SYNC
;
2237 bio_add_page(bio
, page
, length
, pg_offset
);
2239 if (btrfsic_submit_bio_wait(bio
)) {
2240 /* try to remap that extent elsewhere? */
2241 btrfs_bio_counter_dec(fs_info
);
2243 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2247 btrfs_info_rl_in_rcu(fs_info
,
2248 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2250 rcu_str_deref(dev
->name
), sector
);
2251 btrfs_bio_counter_dec(fs_info
);
2256 int btrfs_repair_eb_io_failure(struct extent_buffer
*eb
, int mirror_num
)
2258 struct btrfs_fs_info
*fs_info
= eb
->fs_info
;
2259 u64 start
= eb
->start
;
2260 int i
, num_pages
= num_extent_pages(eb
);
2263 if (sb_rdonly(fs_info
->sb
))
2266 for (i
= 0; i
< num_pages
; i
++) {
2267 struct page
*p
= eb
->pages
[i
];
2269 ret
= repair_io_failure(fs_info
, 0, start
, PAGE_SIZE
, start
, p
,
2270 start
- page_offset(p
), mirror_num
);
2280 * each time an IO finishes, we do a fast check in the IO failure tree
2281 * to see if we need to process or clean up an io_failure_record
2283 int clean_io_failure(struct btrfs_fs_info
*fs_info
,
2284 struct extent_io_tree
*failure_tree
,
2285 struct extent_io_tree
*io_tree
, u64 start
,
2286 struct page
*page
, u64 ino
, unsigned int pg_offset
)
2289 struct io_failure_record
*failrec
;
2290 struct extent_state
*state
;
2295 ret
= count_range_bits(failure_tree
, &private, (u64
)-1, 1,
2300 ret
= get_state_failrec(failure_tree
, start
, &failrec
);
2304 BUG_ON(!failrec
->this_mirror
);
2306 if (failrec
->in_validation
) {
2307 /* there was no real error, just free the record */
2308 btrfs_debug(fs_info
,
2309 "clean_io_failure: freeing dummy error at %llu",
2313 if (sb_rdonly(fs_info
->sb
))
2316 spin_lock(&io_tree
->lock
);
2317 state
= find_first_extent_bit_state(io_tree
,
2320 spin_unlock(&io_tree
->lock
);
2322 if (state
&& state
->start
<= failrec
->start
&&
2323 state
->end
>= failrec
->start
+ failrec
->len
- 1) {
2324 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2326 if (num_copies
> 1) {
2327 repair_io_failure(fs_info
, ino
, start
, failrec
->len
,
2328 failrec
->logical
, page
, pg_offset
,
2329 failrec
->failed_mirror
);
2334 free_io_failure(failure_tree
, io_tree
, failrec
);
2340 * Can be called when
2341 * - hold extent lock
2342 * - under ordered extent
2343 * - the inode is freeing
2345 void btrfs_free_io_failure_record(struct btrfs_inode
*inode
, u64 start
, u64 end
)
2347 struct extent_io_tree
*failure_tree
= &inode
->io_failure_tree
;
2348 struct io_failure_record
*failrec
;
2349 struct extent_state
*state
, *next
;
2351 if (RB_EMPTY_ROOT(&failure_tree
->state
))
2354 spin_lock(&failure_tree
->lock
);
2355 state
= find_first_extent_bit_state(failure_tree
, start
, EXTENT_DIRTY
);
2357 if (state
->start
> end
)
2360 ASSERT(state
->end
<= end
);
2362 next
= next_state(state
);
2364 failrec
= state
->failrec
;
2365 free_extent_state(state
);
2370 spin_unlock(&failure_tree
->lock
);
2373 int btrfs_get_io_failure_record(struct inode
*inode
, u64 start
, u64 end
,
2374 struct io_failure_record
**failrec_ret
)
2376 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2377 struct io_failure_record
*failrec
;
2378 struct extent_map
*em
;
2379 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2380 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2381 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2385 ret
= get_state_failrec(failure_tree
, start
, &failrec
);
2387 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2391 failrec
->start
= start
;
2392 failrec
->len
= end
- start
+ 1;
2393 failrec
->this_mirror
= 0;
2394 failrec
->bio_flags
= 0;
2395 failrec
->in_validation
= 0;
2397 read_lock(&em_tree
->lock
);
2398 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2400 read_unlock(&em_tree
->lock
);
2405 if (em
->start
> start
|| em
->start
+ em
->len
<= start
) {
2406 free_extent_map(em
);
2409 read_unlock(&em_tree
->lock
);
2415 logical
= start
- em
->start
;
2416 logical
= em
->block_start
+ logical
;
2417 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2418 logical
= em
->block_start
;
2419 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2420 extent_set_compress_type(&failrec
->bio_flags
,
2424 btrfs_debug(fs_info
,
2425 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2426 logical
, start
, failrec
->len
);
2428 failrec
->logical
= logical
;
2429 free_extent_map(em
);
2431 /* set the bits in the private failure tree */
2432 ret
= set_extent_bits(failure_tree
, start
, end
,
2433 EXTENT_LOCKED
| EXTENT_DIRTY
);
2435 ret
= set_state_failrec(failure_tree
, start
, failrec
);
2436 /* set the bits in the inode's tree */
2438 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
);
2444 btrfs_debug(fs_info
,
2445 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2446 failrec
->logical
, failrec
->start
, failrec
->len
,
2447 failrec
->in_validation
);
2449 * when data can be on disk more than twice, add to failrec here
2450 * (e.g. with a list for failed_mirror) to make
2451 * clean_io_failure() clean all those errors at once.
2455 *failrec_ret
= failrec
;
2460 bool btrfs_check_repairable(struct inode
*inode
, unsigned failed_bio_pages
,
2461 struct io_failure_record
*failrec
, int failed_mirror
)
2463 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2466 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
, failrec
->len
);
2467 if (num_copies
== 1) {
2469 * we only have a single copy of the data, so don't bother with
2470 * all the retry and error correction code that follows. no
2471 * matter what the error is, it is very likely to persist.
2473 btrfs_debug(fs_info
,
2474 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2475 num_copies
, failrec
->this_mirror
, failed_mirror
);
2480 * there are two premises:
2481 * a) deliver good data to the caller
2482 * b) correct the bad sectors on disk
2484 if (failed_bio_pages
> 1) {
2486 * to fulfill b), we need to know the exact failing sectors, as
2487 * we don't want to rewrite any more than the failed ones. thus,
2488 * we need separate read requests for the failed bio
2490 * if the following BUG_ON triggers, our validation request got
2491 * merged. we need separate requests for our algorithm to work.
2493 BUG_ON(failrec
->in_validation
);
2494 failrec
->in_validation
= 1;
2495 failrec
->this_mirror
= failed_mirror
;
2498 * we're ready to fulfill a) and b) alongside. get a good copy
2499 * of the failed sector and if we succeed, we have setup
2500 * everything for repair_io_failure to do the rest for us.
2502 if (failrec
->in_validation
) {
2503 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2504 failrec
->in_validation
= 0;
2505 failrec
->this_mirror
= 0;
2507 failrec
->failed_mirror
= failed_mirror
;
2508 failrec
->this_mirror
++;
2509 if (failrec
->this_mirror
== failed_mirror
)
2510 failrec
->this_mirror
++;
2513 if (failrec
->this_mirror
> num_copies
) {
2514 btrfs_debug(fs_info
,
2515 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2516 num_copies
, failrec
->this_mirror
, failed_mirror
);
2524 struct bio
*btrfs_create_repair_bio(struct inode
*inode
, struct bio
*failed_bio
,
2525 struct io_failure_record
*failrec
,
2526 struct page
*page
, int pg_offset
, int icsum
,
2527 bio_end_io_t
*endio_func
, void *data
)
2529 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2531 struct btrfs_io_bio
*btrfs_failed_bio
;
2532 struct btrfs_io_bio
*btrfs_bio
;
2534 bio
= btrfs_io_bio_alloc(1);
2535 bio
->bi_end_io
= endio_func
;
2536 bio
->bi_iter
.bi_sector
= failrec
->logical
>> 9;
2537 bio_set_dev(bio
, fs_info
->fs_devices
->latest_bdev
);
2538 bio
->bi_iter
.bi_size
= 0;
2539 bio
->bi_private
= data
;
2541 btrfs_failed_bio
= btrfs_io_bio(failed_bio
);
2542 if (btrfs_failed_bio
->csum
) {
2543 u16 csum_size
= btrfs_super_csum_size(fs_info
->super_copy
);
2545 btrfs_bio
= btrfs_io_bio(bio
);
2546 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
2548 memcpy(btrfs_bio
->csum
, btrfs_failed_bio
->csum
+ icsum
,
2552 bio_add_page(bio
, page
, failrec
->len
, pg_offset
);
2558 * This is a generic handler for readpage errors. If other copies exist, read
2559 * those and write back good data to the failed position. Does not investigate
2560 * in remapping the failed extent elsewhere, hoping the device will be smart
2561 * enough to do this as needed
2563 static int bio_readpage_error(struct bio
*failed_bio
, u64 phy_offset
,
2564 struct page
*page
, u64 start
, u64 end
,
2567 struct io_failure_record
*failrec
;
2568 struct inode
*inode
= page
->mapping
->host
;
2569 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2570 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2573 blk_status_t status
;
2575 unsigned failed_bio_pages
= failed_bio
->bi_iter
.bi_size
>> PAGE_SHIFT
;
2577 BUG_ON(bio_op(failed_bio
) == REQ_OP_WRITE
);
2579 ret
= btrfs_get_io_failure_record(inode
, start
, end
, &failrec
);
2583 if (!btrfs_check_repairable(inode
, failed_bio_pages
, failrec
,
2585 free_io_failure(failure_tree
, tree
, failrec
);
2589 if (failed_bio_pages
> 1)
2590 read_mode
|= REQ_FAILFAST_DEV
;
2592 phy_offset
>>= inode
->i_sb
->s_blocksize_bits
;
2593 bio
= btrfs_create_repair_bio(inode
, failed_bio
, failrec
, page
,
2594 start
- page_offset(page
),
2595 (int)phy_offset
, failed_bio
->bi_end_io
,
2597 bio
->bi_opf
= REQ_OP_READ
| read_mode
;
2599 btrfs_debug(btrfs_sb(inode
->i_sb
),
2600 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2601 read_mode
, failrec
->this_mirror
, failrec
->in_validation
);
2603 status
= tree
->ops
->submit_bio_hook(tree
->private_data
, bio
, failrec
->this_mirror
,
2604 failrec
->bio_flags
);
2606 free_io_failure(failure_tree
, tree
, failrec
);
2608 ret
= blk_status_to_errno(status
);
2614 /* lots and lots of room for performance fixes in the end_bio funcs */
2616 void end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2618 int uptodate
= (err
== 0);
2621 btrfs_writepage_endio_finish_ordered(page
, start
, end
, uptodate
);
2624 ClearPageUptodate(page
);
2626 ret
= err
< 0 ? err
: -EIO
;
2627 mapping_set_error(page
->mapping
, ret
);
2632 * after a writepage IO is done, we need to:
2633 * clear the uptodate bits on error
2634 * clear the writeback bits in the extent tree for this IO
2635 * end_page_writeback if the page has no more pending IO
2637 * Scheduling is not allowed, so the extent state tree is expected
2638 * to have one and only one object corresponding to this IO.
2640 static void end_bio_extent_writepage(struct bio
*bio
)
2642 int error
= blk_status_to_errno(bio
->bi_status
);
2643 struct bio_vec
*bvec
;
2646 struct bvec_iter_all iter_all
;
2648 ASSERT(!bio_flagged(bio
, BIO_CLONED
));
2649 bio_for_each_segment_all(bvec
, bio
, iter_all
) {
2650 struct page
*page
= bvec
->bv_page
;
2651 struct inode
*inode
= page
->mapping
->host
;
2652 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2654 /* We always issue full-page reads, but if some block
2655 * in a page fails to read, blk_update_request() will
2656 * advance bv_offset and adjust bv_len to compensate.
2657 * Print a warning for nonzero offsets, and an error
2658 * if they don't add up to a full page. */
2659 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_SIZE
) {
2660 if (bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_SIZE
)
2662 "partial page write in btrfs with offset %u and length %u",
2663 bvec
->bv_offset
, bvec
->bv_len
);
2666 "incomplete page write in btrfs with offset %u and length %u",
2667 bvec
->bv_offset
, bvec
->bv_len
);
2670 start
= page_offset(page
);
2671 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2673 end_extent_writepage(page
, error
, start
, end
);
2674 end_page_writeback(page
);
2681 endio_readpage_release_extent(struct extent_io_tree
*tree
, u64 start
, u64 len
,
2684 struct extent_state
*cached
= NULL
;
2685 u64 end
= start
+ len
- 1;
2687 if (uptodate
&& tree
->track_uptodate
)
2688 set_extent_uptodate(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2689 unlock_extent_cached_atomic(tree
, start
, end
, &cached
);
2693 * after a readpage IO is done, we need to:
2694 * clear the uptodate bits on error
2695 * set the uptodate bits if things worked
2696 * set the page up to date if all extents in the tree are uptodate
2697 * clear the lock bit in the extent tree
2698 * unlock the page if there are no other extents locked for it
2700 * Scheduling is not allowed, so the extent state tree is expected
2701 * to have one and only one object corresponding to this IO.
2703 static void end_bio_extent_readpage(struct bio
*bio
)
2705 struct bio_vec
*bvec
;
2706 int uptodate
= !bio
->bi_status
;
2707 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2708 struct extent_io_tree
*tree
, *failure_tree
;
2713 u64 extent_start
= 0;
2717 struct bvec_iter_all iter_all
;
2719 ASSERT(!bio_flagged(bio
, BIO_CLONED
));
2720 bio_for_each_segment_all(bvec
, bio
, iter_all
) {
2721 struct page
*page
= bvec
->bv_page
;
2722 struct inode
*inode
= page
->mapping
->host
;
2723 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2724 bool data_inode
= btrfs_ino(BTRFS_I(inode
))
2725 != BTRFS_BTREE_INODE_OBJECTID
;
2727 btrfs_debug(fs_info
,
2728 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2729 (u64
)bio
->bi_iter
.bi_sector
, bio
->bi_status
,
2730 io_bio
->mirror_num
);
2731 tree
= &BTRFS_I(inode
)->io_tree
;
2732 failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2734 /* We always issue full-page reads, but if some block
2735 * in a page fails to read, blk_update_request() will
2736 * advance bv_offset and adjust bv_len to compensate.
2737 * Print a warning for nonzero offsets, and an error
2738 * if they don't add up to a full page. */
2739 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_SIZE
) {
2740 if (bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_SIZE
)
2742 "partial page read in btrfs with offset %u and length %u",
2743 bvec
->bv_offset
, bvec
->bv_len
);
2746 "incomplete page read in btrfs with offset %u and length %u",
2747 bvec
->bv_offset
, bvec
->bv_len
);
2750 start
= page_offset(page
);
2751 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2754 mirror
= io_bio
->mirror_num
;
2755 if (likely(uptodate
)) {
2756 ret
= tree
->ops
->readpage_end_io_hook(io_bio
, offset
,
2762 clean_io_failure(BTRFS_I(inode
)->root
->fs_info
,
2763 failure_tree
, tree
, start
,
2765 btrfs_ino(BTRFS_I(inode
)), 0);
2768 if (likely(uptodate
))
2774 * The generic bio_readpage_error handles errors the
2775 * following way: If possible, new read requests are
2776 * created and submitted and will end up in
2777 * end_bio_extent_readpage as well (if we're lucky,
2778 * not in the !uptodate case). In that case it returns
2779 * 0 and we just go on with the next page in our bio.
2780 * If it can't handle the error it will return -EIO and
2781 * we remain responsible for that page.
2783 ret
= bio_readpage_error(bio
, offset
, page
, start
, end
,
2786 uptodate
= !bio
->bi_status
;
2791 struct extent_buffer
*eb
;
2793 eb
= (struct extent_buffer
*)page
->private;
2794 set_bit(EXTENT_BUFFER_READ_ERR
, &eb
->bflags
);
2795 eb
->read_mirror
= mirror
;
2796 atomic_dec(&eb
->io_pages
);
2797 if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD
,
2799 btree_readahead_hook(eb
, -EIO
);
2802 if (likely(uptodate
)) {
2803 loff_t i_size
= i_size_read(inode
);
2804 pgoff_t end_index
= i_size
>> PAGE_SHIFT
;
2807 /* Zero out the end if this page straddles i_size */
2808 off
= offset_in_page(i_size
);
2809 if (page
->index
== end_index
&& off
)
2810 zero_user_segment(page
, off
, PAGE_SIZE
);
2811 SetPageUptodate(page
);
2813 ClearPageUptodate(page
);
2819 if (unlikely(!uptodate
)) {
2821 endio_readpage_release_extent(tree
,
2827 endio_readpage_release_extent(tree
, start
,
2828 end
- start
+ 1, 0);
2829 } else if (!extent_len
) {
2830 extent_start
= start
;
2831 extent_len
= end
+ 1 - start
;
2832 } else if (extent_start
+ extent_len
== start
) {
2833 extent_len
+= end
+ 1 - start
;
2835 endio_readpage_release_extent(tree
, extent_start
,
2836 extent_len
, uptodate
);
2837 extent_start
= start
;
2838 extent_len
= end
+ 1 - start
;
2843 endio_readpage_release_extent(tree
, extent_start
, extent_len
,
2845 btrfs_io_bio_free_csum(io_bio
);
2850 * Initialize the members up to but not including 'bio'. Use after allocating a
2851 * new bio by bio_alloc_bioset as it does not initialize the bytes outside of
2852 * 'bio' because use of __GFP_ZERO is not supported.
2854 static inline void btrfs_io_bio_init(struct btrfs_io_bio
*btrfs_bio
)
2856 memset(btrfs_bio
, 0, offsetof(struct btrfs_io_bio
, bio
));
2860 * The following helpers allocate a bio. As it's backed by a bioset, it'll
2861 * never fail. We're returning a bio right now but you can call btrfs_io_bio
2862 * for the appropriate container_of magic
2864 struct bio
*btrfs_bio_alloc(u64 first_byte
)
2868 bio
= bio_alloc_bioset(GFP_NOFS
, BIO_MAX_PAGES
, &btrfs_bioset
);
2869 bio
->bi_iter
.bi_sector
= first_byte
>> 9;
2870 btrfs_io_bio_init(btrfs_io_bio(bio
));
2874 struct bio
*btrfs_bio_clone(struct bio
*bio
)
2876 struct btrfs_io_bio
*btrfs_bio
;
2879 /* Bio allocation backed by a bioset does not fail */
2880 new = bio_clone_fast(bio
, GFP_NOFS
, &btrfs_bioset
);
2881 btrfs_bio
= btrfs_io_bio(new);
2882 btrfs_io_bio_init(btrfs_bio
);
2883 btrfs_bio
->iter
= bio
->bi_iter
;
2887 struct bio
*btrfs_io_bio_alloc(unsigned int nr_iovecs
)
2891 /* Bio allocation backed by a bioset does not fail */
2892 bio
= bio_alloc_bioset(GFP_NOFS
, nr_iovecs
, &btrfs_bioset
);
2893 btrfs_io_bio_init(btrfs_io_bio(bio
));
2897 struct bio
*btrfs_bio_clone_partial(struct bio
*orig
, int offset
, int size
)
2900 struct btrfs_io_bio
*btrfs_bio
;
2902 /* this will never fail when it's backed by a bioset */
2903 bio
= bio_clone_fast(orig
, GFP_NOFS
, &btrfs_bioset
);
2906 btrfs_bio
= btrfs_io_bio(bio
);
2907 btrfs_io_bio_init(btrfs_bio
);
2909 bio_trim(bio
, offset
>> 9, size
>> 9);
2910 btrfs_bio
->iter
= bio
->bi_iter
;
2915 * @opf: bio REQ_OP_* and REQ_* flags as one value
2916 * @tree: tree so we can call our merge_bio hook
2917 * @wbc: optional writeback control for io accounting
2918 * @page: page to add to the bio
2919 * @pg_offset: offset of the new bio or to check whether we are adding
2920 * a contiguous page to the previous one
2921 * @size: portion of page that we want to write
2922 * @offset: starting offset in the page
2923 * @bdev: attach newly created bios to this bdev
2924 * @bio_ret: must be valid pointer, newly allocated bio will be stored there
2925 * @end_io_func: end_io callback for new bio
2926 * @mirror_num: desired mirror to read/write
2927 * @prev_bio_flags: flags of previous bio to see if we can merge the current one
2928 * @bio_flags: flags of the current bio to see if we can merge them
2930 static int submit_extent_page(unsigned int opf
, struct extent_io_tree
*tree
,
2931 struct writeback_control
*wbc
,
2932 struct page
*page
, u64 offset
,
2933 size_t size
, unsigned long pg_offset
,
2934 struct block_device
*bdev
,
2935 struct bio
**bio_ret
,
2936 bio_end_io_t end_io_func
,
2938 unsigned long prev_bio_flags
,
2939 unsigned long bio_flags
,
2940 bool force_bio_submit
)
2944 size_t page_size
= min_t(size_t, size
, PAGE_SIZE
);
2945 sector_t sector
= offset
>> 9;
2951 bool can_merge
= true;
2954 if (prev_bio_flags
& EXTENT_BIO_COMPRESSED
)
2955 contig
= bio
->bi_iter
.bi_sector
== sector
;
2957 contig
= bio_end_sector(bio
) == sector
;
2960 if (btrfs_bio_fits_in_stripe(page
, page_size
, bio
, bio_flags
))
2963 if (prev_bio_flags
!= bio_flags
|| !contig
|| !can_merge
||
2965 bio_add_page(bio
, page
, page_size
, pg_offset
) < page_size
) {
2966 ret
= submit_one_bio(bio
, mirror_num
, prev_bio_flags
);
2974 wbc_account_io(wbc
, page
, page_size
);
2979 bio
= btrfs_bio_alloc(offset
);
2980 bio_set_dev(bio
, bdev
);
2981 bio_add_page(bio
, page
, page_size
, pg_offset
);
2982 bio
->bi_end_io
= end_io_func
;
2983 bio
->bi_private
= tree
;
2984 bio
->bi_write_hint
= page
->mapping
->host
->i_write_hint
;
2987 wbc_init_bio(wbc
, bio
);
2988 wbc_account_io(wbc
, page
, page_size
);
2996 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2999 if (!PagePrivate(page
)) {
3000 SetPagePrivate(page
);
3002 set_page_private(page
, (unsigned long)eb
);
3004 WARN_ON(page
->private != (unsigned long)eb
);
3008 void set_page_extent_mapped(struct page
*page
)
3010 if (!PagePrivate(page
)) {
3011 SetPagePrivate(page
);
3013 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
3017 static struct extent_map
*
3018 __get_extent_map(struct inode
*inode
, struct page
*page
, size_t pg_offset
,
3019 u64 start
, u64 len
, get_extent_t
*get_extent
,
3020 struct extent_map
**em_cached
)
3022 struct extent_map
*em
;
3024 if (em_cached
&& *em_cached
) {
3026 if (extent_map_in_tree(em
) && start
>= em
->start
&&
3027 start
< extent_map_end(em
)) {
3028 refcount_inc(&em
->refs
);
3032 free_extent_map(em
);
3036 em
= get_extent(BTRFS_I(inode
), page
, pg_offset
, start
, len
, 0);
3037 if (em_cached
&& !IS_ERR_OR_NULL(em
)) {
3039 refcount_inc(&em
->refs
);
3045 * basic readpage implementation. Locked extent state structs are inserted
3046 * into the tree that are removed when the IO is done (by the end_io
3048 * XXX JDM: This needs looking at to ensure proper page locking
3049 * return 0 on success, otherwise return error
3051 static int __do_readpage(struct extent_io_tree
*tree
,
3053 get_extent_t
*get_extent
,
3054 struct extent_map
**em_cached
,
3055 struct bio
**bio
, int mirror_num
,
3056 unsigned long *bio_flags
, unsigned int read_flags
,
3059 struct inode
*inode
= page
->mapping
->host
;
3060 u64 start
= page_offset(page
);
3061 const u64 end
= start
+ PAGE_SIZE
- 1;
3064 u64 last_byte
= i_size_read(inode
);
3067 struct extent_map
*em
;
3068 struct block_device
*bdev
;
3071 size_t pg_offset
= 0;
3073 size_t disk_io_size
;
3074 size_t blocksize
= inode
->i_sb
->s_blocksize
;
3075 unsigned long this_bio_flag
= 0;
3077 set_page_extent_mapped(page
);
3079 if (!PageUptodate(page
)) {
3080 if (cleancache_get_page(page
) == 0) {
3081 BUG_ON(blocksize
!= PAGE_SIZE
);
3082 unlock_extent(tree
, start
, end
);
3087 if (page
->index
== last_byte
>> PAGE_SHIFT
) {
3089 size_t zero_offset
= offset_in_page(last_byte
);
3092 iosize
= PAGE_SIZE
- zero_offset
;
3093 userpage
= kmap_atomic(page
);
3094 memset(userpage
+ zero_offset
, 0, iosize
);
3095 flush_dcache_page(page
);
3096 kunmap_atomic(userpage
);
3099 while (cur
<= end
) {
3100 bool force_bio_submit
= false;
3103 if (cur
>= last_byte
) {
3105 struct extent_state
*cached
= NULL
;
3107 iosize
= PAGE_SIZE
- pg_offset
;
3108 userpage
= kmap_atomic(page
);
3109 memset(userpage
+ pg_offset
, 0, iosize
);
3110 flush_dcache_page(page
);
3111 kunmap_atomic(userpage
);
3112 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
3114 unlock_extent_cached(tree
, cur
,
3115 cur
+ iosize
- 1, &cached
);
3118 em
= __get_extent_map(inode
, page
, pg_offset
, cur
,
3119 end
- cur
+ 1, get_extent
, em_cached
);
3120 if (IS_ERR_OR_NULL(em
)) {
3122 unlock_extent(tree
, cur
, end
);
3125 extent_offset
= cur
- em
->start
;
3126 BUG_ON(extent_map_end(em
) <= cur
);
3129 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
3130 this_bio_flag
|= EXTENT_BIO_COMPRESSED
;
3131 extent_set_compress_type(&this_bio_flag
,
3135 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
3136 cur_end
= min(extent_map_end(em
) - 1, end
);
3137 iosize
= ALIGN(iosize
, blocksize
);
3138 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
3139 disk_io_size
= em
->block_len
;
3140 offset
= em
->block_start
;
3142 offset
= em
->block_start
+ extent_offset
;
3143 disk_io_size
= iosize
;
3146 block_start
= em
->block_start
;
3147 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
3148 block_start
= EXTENT_MAP_HOLE
;
3151 * If we have a file range that points to a compressed extent
3152 * and it's followed by a consecutive file range that points to
3153 * to the same compressed extent (possibly with a different
3154 * offset and/or length, so it either points to the whole extent
3155 * or only part of it), we must make sure we do not submit a
3156 * single bio to populate the pages for the 2 ranges because
3157 * this makes the compressed extent read zero out the pages
3158 * belonging to the 2nd range. Imagine the following scenario:
3161 * [0 - 8K] [8K - 24K]
3164 * points to extent X, points to extent X,
3165 * offset 4K, length of 8K offset 0, length 16K
3167 * [extent X, compressed length = 4K uncompressed length = 16K]
3169 * If the bio to read the compressed extent covers both ranges,
3170 * it will decompress extent X into the pages belonging to the
3171 * first range and then it will stop, zeroing out the remaining
3172 * pages that belong to the other range that points to extent X.
3173 * So here we make sure we submit 2 bios, one for the first
3174 * range and another one for the third range. Both will target
3175 * the same physical extent from disk, but we can't currently
3176 * make the compressed bio endio callback populate the pages
3177 * for both ranges because each compressed bio is tightly
3178 * coupled with a single extent map, and each range can have
3179 * an extent map with a different offset value relative to the
3180 * uncompressed data of our extent and different lengths. This
3181 * is a corner case so we prioritize correctness over
3182 * non-optimal behavior (submitting 2 bios for the same extent).
3184 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
) &&
3185 prev_em_start
&& *prev_em_start
!= (u64
)-1 &&
3186 *prev_em_start
!= em
->start
)
3187 force_bio_submit
= true;
3190 *prev_em_start
= em
->start
;
3192 free_extent_map(em
);
3195 /* we've found a hole, just zero and go on */
3196 if (block_start
== EXTENT_MAP_HOLE
) {
3198 struct extent_state
*cached
= NULL
;
3200 userpage
= kmap_atomic(page
);
3201 memset(userpage
+ pg_offset
, 0, iosize
);
3202 flush_dcache_page(page
);
3203 kunmap_atomic(userpage
);
3205 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
3207 unlock_extent_cached(tree
, cur
,
3208 cur
+ iosize
- 1, &cached
);
3210 pg_offset
+= iosize
;
3213 /* the get_extent function already copied into the page */
3214 if (test_range_bit(tree
, cur
, cur_end
,
3215 EXTENT_UPTODATE
, 1, NULL
)) {
3216 check_page_uptodate(tree
, page
);
3217 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3219 pg_offset
+= iosize
;
3222 /* we have an inline extent but it didn't get marked up
3223 * to date. Error out
3225 if (block_start
== EXTENT_MAP_INLINE
) {
3227 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3229 pg_offset
+= iosize
;
3233 ret
= submit_extent_page(REQ_OP_READ
| read_flags
, tree
, NULL
,
3234 page
, offset
, disk_io_size
,
3235 pg_offset
, bdev
, bio
,
3236 end_bio_extent_readpage
, mirror_num
,
3242 *bio_flags
= this_bio_flag
;
3245 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3249 pg_offset
+= iosize
;
3253 if (!PageError(page
))
3254 SetPageUptodate(page
);
3260 static inline void contiguous_readpages(struct extent_io_tree
*tree
,
3261 struct page
*pages
[], int nr_pages
,
3263 struct extent_map
**em_cached
,
3265 unsigned long *bio_flags
,
3268 struct btrfs_inode
*inode
= BTRFS_I(pages
[0]->mapping
->host
);
3271 btrfs_lock_and_flush_ordered_range(tree
, inode
, start
, end
, NULL
);
3273 for (index
= 0; index
< nr_pages
; index
++) {
3274 __do_readpage(tree
, pages
[index
], btrfs_get_extent
, em_cached
,
3275 bio
, 0, bio_flags
, REQ_RAHEAD
, prev_em_start
);
3276 put_page(pages
[index
]);
3280 static int __extent_read_full_page(struct extent_io_tree
*tree
,
3282 get_extent_t
*get_extent
,
3283 struct bio
**bio
, int mirror_num
,
3284 unsigned long *bio_flags
,
3285 unsigned int read_flags
)
3287 struct btrfs_inode
*inode
= BTRFS_I(page
->mapping
->host
);
3288 u64 start
= page_offset(page
);
3289 u64 end
= start
+ PAGE_SIZE
- 1;
3292 btrfs_lock_and_flush_ordered_range(tree
, inode
, start
, end
, NULL
);
3294 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, bio
, mirror_num
,
3295 bio_flags
, read_flags
, NULL
);
3299 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3300 get_extent_t
*get_extent
, int mirror_num
)
3302 struct bio
*bio
= NULL
;
3303 unsigned long bio_flags
= 0;
3306 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
3309 ret
= submit_one_bio(bio
, mirror_num
, bio_flags
);
3313 static void update_nr_written(struct writeback_control
*wbc
,
3314 unsigned long nr_written
)
3316 wbc
->nr_to_write
-= nr_written
;
3320 * helper for __extent_writepage, doing all of the delayed allocation setup.
3322 * This returns 1 if btrfs_run_delalloc_range function did all the work required
3323 * to write the page (copy into inline extent). In this case the IO has
3324 * been started and the page is already unlocked.
3326 * This returns 0 if all went well (page still locked)
3327 * This returns < 0 if there were errors (page still locked)
3329 static noinline_for_stack
int writepage_delalloc(struct inode
*inode
,
3330 struct page
*page
, struct writeback_control
*wbc
,
3331 u64 delalloc_start
, unsigned long *nr_written
)
3333 u64 page_end
= delalloc_start
+ PAGE_SIZE
- 1;
3335 u64 delalloc_to_write
= 0;
3336 u64 delalloc_end
= 0;
3338 int page_started
= 0;
3341 while (delalloc_end
< page_end
) {
3342 found
= find_lock_delalloc_range(inode
, page
,
3346 delalloc_start
= delalloc_end
+ 1;
3349 ret
= btrfs_run_delalloc_range(inode
, page
, delalloc_start
,
3350 delalloc_end
, &page_started
, nr_written
, wbc
);
3354 * btrfs_run_delalloc_range should return < 0 for error
3355 * but just in case, we use > 0 here meaning the IO is
3356 * started, so we don't want to return > 0 unless
3357 * things are going well.
3359 ret
= ret
< 0 ? ret
: -EIO
;
3363 * delalloc_end is already one less than the total length, so
3364 * we don't subtract one from PAGE_SIZE
3366 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3367 PAGE_SIZE
) >> PAGE_SHIFT
;
3368 delalloc_start
= delalloc_end
+ 1;
3370 if (wbc
->nr_to_write
< delalloc_to_write
) {
3373 if (delalloc_to_write
< thresh
* 2)
3374 thresh
= delalloc_to_write
;
3375 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3379 /* did the fill delalloc function already unlock and start
3384 * we've unlocked the page, so we can't update
3385 * the mapping's writeback index, just update
3388 wbc
->nr_to_write
-= *nr_written
;
3399 * helper for __extent_writepage. This calls the writepage start hooks,
3400 * and does the loop to map the page into extents and bios.
3402 * We return 1 if the IO is started and the page is unlocked,
3403 * 0 if all went well (page still locked)
3404 * < 0 if there were errors (page still locked)
3406 static noinline_for_stack
int __extent_writepage_io(struct inode
*inode
,
3408 struct writeback_control
*wbc
,
3409 struct extent_page_data
*epd
,
3411 unsigned long nr_written
,
3412 unsigned int write_flags
, int *nr_ret
)
3414 struct extent_io_tree
*tree
= epd
->tree
;
3415 u64 start
= page_offset(page
);
3416 u64 page_end
= start
+ PAGE_SIZE
- 1;
3422 struct extent_map
*em
;
3423 struct block_device
*bdev
;
3424 size_t pg_offset
= 0;
3430 ret
= btrfs_writepage_cow_fixup(page
, start
, page_end
);
3432 /* Fixup worker will requeue */
3434 wbc
->pages_skipped
++;
3436 redirty_page_for_writepage(wbc
, page
);
3438 update_nr_written(wbc
, nr_written
);
3444 * we don't want to touch the inode after unlocking the page,
3445 * so we update the mapping writeback index now
3447 update_nr_written(wbc
, nr_written
+ 1);
3450 if (i_size
<= start
) {
3451 btrfs_writepage_endio_finish_ordered(page
, start
, page_end
, 1);
3455 blocksize
= inode
->i_sb
->s_blocksize
;
3457 while (cur
<= end
) {
3461 if (cur
>= i_size
) {
3462 btrfs_writepage_endio_finish_ordered(page
, cur
,
3466 em
= btrfs_get_extent(BTRFS_I(inode
), page
, pg_offset
, cur
,
3468 if (IS_ERR_OR_NULL(em
)) {
3470 ret
= PTR_ERR_OR_ZERO(em
);
3474 extent_offset
= cur
- em
->start
;
3475 em_end
= extent_map_end(em
);
3476 BUG_ON(em_end
<= cur
);
3478 iosize
= min(em_end
- cur
, end
- cur
+ 1);
3479 iosize
= ALIGN(iosize
, blocksize
);
3480 offset
= em
->block_start
+ extent_offset
;
3482 block_start
= em
->block_start
;
3483 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3484 free_extent_map(em
);
3488 * compressed and inline extents are written through other
3491 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3492 block_start
== EXTENT_MAP_INLINE
) {
3494 * end_io notification does not happen here for
3495 * compressed extents
3498 btrfs_writepage_endio_finish_ordered(page
, cur
,
3501 else if (compressed
) {
3502 /* we don't want to end_page_writeback on
3503 * a compressed extent. this happens
3510 pg_offset
+= iosize
;
3514 btrfs_set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3515 if (!PageWriteback(page
)) {
3516 btrfs_err(BTRFS_I(inode
)->root
->fs_info
,
3517 "page %lu not writeback, cur %llu end %llu",
3518 page
->index
, cur
, end
);
3521 ret
= submit_extent_page(REQ_OP_WRITE
| write_flags
, tree
, wbc
,
3522 page
, offset
, iosize
, pg_offset
,
3524 end_bio_extent_writepage
,
3528 if (PageWriteback(page
))
3529 end_page_writeback(page
);
3533 pg_offset
+= iosize
;
3542 * the writepage semantics are similar to regular writepage. extent
3543 * records are inserted to lock ranges in the tree, and as dirty areas
3544 * are found, they are marked writeback. Then the lock bits are removed
3545 * and the end_io handler clears the writeback ranges
3547 * Return 0 if everything goes well.
3548 * Return <0 for error.
3550 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
3551 struct extent_page_data
*epd
)
3553 struct inode
*inode
= page
->mapping
->host
;
3554 u64 start
= page_offset(page
);
3555 u64 page_end
= start
+ PAGE_SIZE
- 1;
3558 size_t pg_offset
= 0;
3559 loff_t i_size
= i_size_read(inode
);
3560 unsigned long end_index
= i_size
>> PAGE_SHIFT
;
3561 unsigned int write_flags
= 0;
3562 unsigned long nr_written
= 0;
3564 write_flags
= wbc_to_write_flags(wbc
);
3566 trace___extent_writepage(page
, inode
, wbc
);
3568 WARN_ON(!PageLocked(page
));
3570 ClearPageError(page
);
3572 pg_offset
= offset_in_page(i_size
);
3573 if (page
->index
> end_index
||
3574 (page
->index
== end_index
&& !pg_offset
)) {
3575 page
->mapping
->a_ops
->invalidatepage(page
, 0, PAGE_SIZE
);
3580 if (page
->index
== end_index
) {
3583 userpage
= kmap_atomic(page
);
3584 memset(userpage
+ pg_offset
, 0,
3585 PAGE_SIZE
- pg_offset
);
3586 kunmap_atomic(userpage
);
3587 flush_dcache_page(page
);
3592 set_page_extent_mapped(page
);
3594 if (!epd
->extent_locked
) {
3595 ret
= writepage_delalloc(inode
, page
, wbc
, start
, &nr_written
);
3602 ret
= __extent_writepage_io(inode
, page
, wbc
, epd
,
3603 i_size
, nr_written
, write_flags
, &nr
);
3609 /* make sure the mapping tag for page dirty gets cleared */
3610 set_page_writeback(page
);
3611 end_page_writeback(page
);
3613 if (PageError(page
)) {
3614 ret
= ret
< 0 ? ret
: -EIO
;
3615 end_extent_writepage(page
, ret
, start
, page_end
);
3625 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3627 wait_on_bit_io(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
,
3628 TASK_UNINTERRUPTIBLE
);
3632 * Lock eb pages and flush the bio if we can't the locks
3634 * Return 0 if nothing went wrong
3635 * Return >0 is same as 0, except bio is not submitted
3636 * Return <0 if something went wrong, no page is locked
3638 static noinline_for_stack
int lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3639 struct extent_page_data
*epd
)
3641 struct btrfs_fs_info
*fs_info
= eb
->fs_info
;
3642 int i
, num_pages
, failed_page_nr
;
3646 if (!btrfs_try_tree_write_lock(eb
)) {
3647 ret
= flush_write_bio(epd
);
3651 btrfs_tree_lock(eb
);
3654 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3655 btrfs_tree_unlock(eb
);
3659 ret
= flush_write_bio(epd
);
3665 wait_on_extent_buffer_writeback(eb
);
3666 btrfs_tree_lock(eb
);
3667 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3669 btrfs_tree_unlock(eb
);
3674 * We need to do this to prevent races in people who check if the eb is
3675 * under IO since we can end up having no IO bits set for a short period
3678 spin_lock(&eb
->refs_lock
);
3679 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3680 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3681 spin_unlock(&eb
->refs_lock
);
3682 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3683 percpu_counter_add_batch(&fs_info
->dirty_metadata_bytes
,
3685 fs_info
->dirty_metadata_batch
);
3688 spin_unlock(&eb
->refs_lock
);
3691 btrfs_tree_unlock(eb
);
3696 num_pages
= num_extent_pages(eb
);
3697 for (i
= 0; i
< num_pages
; i
++) {
3698 struct page
*p
= eb
->pages
[i
];
3700 if (!trylock_page(p
)) {
3702 ret
= flush_write_bio(epd
);
3715 /* Unlock already locked pages */
3716 for (i
= 0; i
< failed_page_nr
; i
++)
3717 unlock_page(eb
->pages
[i
]);
3721 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3723 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3724 smp_mb__after_atomic();
3725 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3728 static void set_btree_ioerr(struct page
*page
)
3730 struct extent_buffer
*eb
= (struct extent_buffer
*)page
->private;
3733 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
))
3737 * If writeback for a btree extent that doesn't belong to a log tree
3738 * failed, increment the counter transaction->eb_write_errors.
3739 * We do this because while the transaction is running and before it's
3740 * committing (when we call filemap_fdata[write|wait]_range against
3741 * the btree inode), we might have
3742 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3743 * returns an error or an error happens during writeback, when we're
3744 * committing the transaction we wouldn't know about it, since the pages
3745 * can be no longer dirty nor marked anymore for writeback (if a
3746 * subsequent modification to the extent buffer didn't happen before the
3747 * transaction commit), which makes filemap_fdata[write|wait]_range not
3748 * able to find the pages tagged with SetPageError at transaction
3749 * commit time. So if this happens we must abort the transaction,
3750 * otherwise we commit a super block with btree roots that point to
3751 * btree nodes/leafs whose content on disk is invalid - either garbage
3752 * or the content of some node/leaf from a past generation that got
3753 * cowed or deleted and is no longer valid.
3755 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3756 * not be enough - we need to distinguish between log tree extents vs
3757 * non-log tree extents, and the next filemap_fdatawait_range() call
3758 * will catch and clear such errors in the mapping - and that call might
3759 * be from a log sync and not from a transaction commit. Also, checking
3760 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3761 * not done and would not be reliable - the eb might have been released
3762 * from memory and reading it back again means that flag would not be
3763 * set (since it's a runtime flag, not persisted on disk).
3765 * Using the flags below in the btree inode also makes us achieve the
3766 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3767 * writeback for all dirty pages and before filemap_fdatawait_range()
3768 * is called, the writeback for all dirty pages had already finished
3769 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3770 * filemap_fdatawait_range() would return success, as it could not know
3771 * that writeback errors happened (the pages were no longer tagged for
3774 switch (eb
->log_index
) {
3776 set_bit(BTRFS_FS_BTREE_ERR
, &eb
->fs_info
->flags
);
3779 set_bit(BTRFS_FS_LOG1_ERR
, &eb
->fs_info
->flags
);
3782 set_bit(BTRFS_FS_LOG2_ERR
, &eb
->fs_info
->flags
);
3785 BUG(); /* unexpected, logic error */
3789 static void end_bio_extent_buffer_writepage(struct bio
*bio
)
3791 struct bio_vec
*bvec
;
3792 struct extent_buffer
*eb
;
3794 struct bvec_iter_all iter_all
;
3796 ASSERT(!bio_flagged(bio
, BIO_CLONED
));
3797 bio_for_each_segment_all(bvec
, bio
, iter_all
) {
3798 struct page
*page
= bvec
->bv_page
;
3800 eb
= (struct extent_buffer
*)page
->private;
3802 done
= atomic_dec_and_test(&eb
->io_pages
);
3804 if (bio
->bi_status
||
3805 test_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
)) {
3806 ClearPageUptodate(page
);
3807 set_btree_ioerr(page
);
3810 end_page_writeback(page
);
3815 end_extent_buffer_writeback(eb
);
3821 static noinline_for_stack
int write_one_eb(struct extent_buffer
*eb
,
3822 struct writeback_control
*wbc
,
3823 struct extent_page_data
*epd
)
3825 struct btrfs_fs_info
*fs_info
= eb
->fs_info
;
3826 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3827 struct extent_io_tree
*tree
= &BTRFS_I(fs_info
->btree_inode
)->io_tree
;
3828 u64 offset
= eb
->start
;
3831 unsigned long start
, end
;
3832 unsigned int write_flags
= wbc_to_write_flags(wbc
) | REQ_META
;
3835 clear_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
);
3836 num_pages
= num_extent_pages(eb
);
3837 atomic_set(&eb
->io_pages
, num_pages
);
3839 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3840 nritems
= btrfs_header_nritems(eb
);
3841 if (btrfs_header_level(eb
) > 0) {
3842 end
= btrfs_node_key_ptr_offset(nritems
);
3844 memzero_extent_buffer(eb
, end
, eb
->len
- end
);
3848 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3850 start
= btrfs_item_nr_offset(nritems
);
3851 end
= BTRFS_LEAF_DATA_OFFSET
+ leaf_data_end(eb
);
3852 memzero_extent_buffer(eb
, start
, end
- start
);
3855 for (i
= 0; i
< num_pages
; i
++) {
3856 struct page
*p
= eb
->pages
[i
];
3858 clear_page_dirty_for_io(p
);
3859 set_page_writeback(p
);
3860 ret
= submit_extent_page(REQ_OP_WRITE
| write_flags
, tree
, wbc
,
3861 p
, offset
, PAGE_SIZE
, 0, bdev
,
3863 end_bio_extent_buffer_writepage
,
3867 if (PageWriteback(p
))
3868 end_page_writeback(p
);
3869 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3870 end_extent_buffer_writeback(eb
);
3874 offset
+= PAGE_SIZE
;
3875 update_nr_written(wbc
, 1);
3879 if (unlikely(ret
)) {
3880 for (; i
< num_pages
; i
++) {
3881 struct page
*p
= eb
->pages
[i
];
3882 clear_page_dirty_for_io(p
);
3890 int btree_write_cache_pages(struct address_space
*mapping
,
3891 struct writeback_control
*wbc
)
3893 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3894 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3895 struct extent_page_data epd
= {
3899 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3903 int nr_to_write_done
= 0;
3904 struct pagevec pvec
;
3907 pgoff_t end
; /* Inclusive */
3911 pagevec_init(&pvec
);
3912 if (wbc
->range_cyclic
) {
3913 index
= mapping
->writeback_index
; /* Start from prev offset */
3916 index
= wbc
->range_start
>> PAGE_SHIFT
;
3917 end
= wbc
->range_end
>> PAGE_SHIFT
;
3920 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3921 tag
= PAGECACHE_TAG_TOWRITE
;
3923 tag
= PAGECACHE_TAG_DIRTY
;
3925 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3926 tag_pages_for_writeback(mapping
, index
, end
);
3927 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3928 (nr_pages
= pagevec_lookup_range_tag(&pvec
, mapping
, &index
, end
,
3933 for (i
= 0; i
< nr_pages
; i
++) {
3934 struct page
*page
= pvec
.pages
[i
];
3936 if (!PagePrivate(page
))
3939 spin_lock(&mapping
->private_lock
);
3940 if (!PagePrivate(page
)) {
3941 spin_unlock(&mapping
->private_lock
);
3945 eb
= (struct extent_buffer
*)page
->private;
3948 * Shouldn't happen and normally this would be a BUG_ON
3949 * but no sense in crashing the users box for something
3950 * we can survive anyway.
3953 spin_unlock(&mapping
->private_lock
);
3957 if (eb
== prev_eb
) {
3958 spin_unlock(&mapping
->private_lock
);
3962 ret
= atomic_inc_not_zero(&eb
->refs
);
3963 spin_unlock(&mapping
->private_lock
);
3968 ret
= lock_extent_buffer_for_io(eb
, &epd
);
3970 free_extent_buffer(eb
);
3974 ret
= write_one_eb(eb
, wbc
, &epd
);
3977 free_extent_buffer(eb
);
3980 free_extent_buffer(eb
);
3983 * the filesystem may choose to bump up nr_to_write.
3984 * We have to make sure to honor the new nr_to_write
3987 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3989 pagevec_release(&pvec
);
3992 if (!scanned
&& !done
) {
3994 * We hit the last page and there is more work to be done: wrap
3995 * back to the start of the file
4003 end_write_bio(&epd
, ret
);
4006 ret
= flush_write_bio(&epd
);
4011 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
4012 * @mapping: address space structure to write
4013 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
4014 * @data: data passed to __extent_writepage function
4016 * If a page is already under I/O, write_cache_pages() skips it, even
4017 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
4018 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
4019 * and msync() need to guarantee that all the data which was dirty at the time
4020 * the call was made get new I/O started against them. If wbc->sync_mode is
4021 * WB_SYNC_ALL then we were called for data integrity and we must wait for
4022 * existing IO to complete.
4024 static int extent_write_cache_pages(struct address_space
*mapping
,
4025 struct writeback_control
*wbc
,
4026 struct extent_page_data
*epd
)
4028 struct inode
*inode
= mapping
->host
;
4031 int nr_to_write_done
= 0;
4032 struct pagevec pvec
;
4035 pgoff_t end
; /* Inclusive */
4037 int range_whole
= 0;
4042 * We have to hold onto the inode so that ordered extents can do their
4043 * work when the IO finishes. The alternative to this is failing to add
4044 * an ordered extent if the igrab() fails there and that is a huge pain
4045 * to deal with, so instead just hold onto the inode throughout the
4046 * writepages operation. If it fails here we are freeing up the inode
4047 * anyway and we'd rather not waste our time writing out stuff that is
4048 * going to be truncated anyway.
4053 pagevec_init(&pvec
);
4054 if (wbc
->range_cyclic
) {
4055 index
= mapping
->writeback_index
; /* Start from prev offset */
4058 index
= wbc
->range_start
>> PAGE_SHIFT
;
4059 end
= wbc
->range_end
>> PAGE_SHIFT
;
4060 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
4066 * We do the tagged writepage as long as the snapshot flush bit is set
4067 * and we are the first one who do the filemap_flush() on this inode.
4069 * The nr_to_write == LONG_MAX is needed to make sure other flushers do
4070 * not race in and drop the bit.
4072 if (range_whole
&& wbc
->nr_to_write
== LONG_MAX
&&
4073 test_and_clear_bit(BTRFS_INODE_SNAPSHOT_FLUSH
,
4074 &BTRFS_I(inode
)->runtime_flags
))
4075 wbc
->tagged_writepages
= 1;
4077 if (wbc
->sync_mode
== WB_SYNC_ALL
|| wbc
->tagged_writepages
)
4078 tag
= PAGECACHE_TAG_TOWRITE
;
4080 tag
= PAGECACHE_TAG_DIRTY
;
4082 if (wbc
->sync_mode
== WB_SYNC_ALL
|| wbc
->tagged_writepages
)
4083 tag_pages_for_writeback(mapping
, index
, end
);
4085 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
4086 (nr_pages
= pagevec_lookup_range_tag(&pvec
, mapping
,
4087 &index
, end
, tag
))) {
4091 for (i
= 0; i
< nr_pages
; i
++) {
4092 struct page
*page
= pvec
.pages
[i
];
4094 done_index
= page
->index
;
4096 * At this point we hold neither the i_pages lock nor
4097 * the page lock: the page may be truncated or
4098 * invalidated (changing page->mapping to NULL),
4099 * or even swizzled back from swapper_space to
4100 * tmpfs file mapping
4102 if (!trylock_page(page
)) {
4103 ret
= flush_write_bio(epd
);
4108 if (unlikely(page
->mapping
!= mapping
)) {
4113 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
4114 if (PageWriteback(page
)) {
4115 ret
= flush_write_bio(epd
);
4118 wait_on_page_writeback(page
);
4121 if (PageWriteback(page
) ||
4122 !clear_page_dirty_for_io(page
)) {
4127 ret
= __extent_writepage(page
, wbc
, epd
);
4130 * done_index is set past this page,
4131 * so media errors will not choke
4132 * background writeout for the entire
4133 * file. This has consequences for
4134 * range_cyclic semantics (ie. it may
4135 * not be suitable for data integrity
4138 done_index
= page
->index
+ 1;
4144 * the filesystem may choose to bump up nr_to_write.
4145 * We have to make sure to honor the new nr_to_write
4148 nr_to_write_done
= wbc
->nr_to_write
<= 0;
4150 pagevec_release(&pvec
);
4153 if (!scanned
&& !done
) {
4155 * We hit the last page and there is more work to be done: wrap
4156 * back to the start of the file
4163 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 && range_whole
))
4164 mapping
->writeback_index
= done_index
;
4166 btrfs_add_delayed_iput(inode
);
4170 int extent_write_full_page(struct page
*page
, struct writeback_control
*wbc
)
4173 struct extent_page_data epd
= {
4175 .tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
,
4177 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
4180 ret
= __extent_writepage(page
, wbc
, &epd
);
4183 end_write_bio(&epd
, ret
);
4187 ret
= flush_write_bio(&epd
);
4192 int extent_write_locked_range(struct inode
*inode
, u64 start
, u64 end
,
4196 struct address_space
*mapping
= inode
->i_mapping
;
4197 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
4199 unsigned long nr_pages
= (end
- start
+ PAGE_SIZE
) >>
4202 struct extent_page_data epd
= {
4206 .sync_io
= mode
== WB_SYNC_ALL
,
4208 struct writeback_control wbc_writepages
= {
4210 .nr_to_write
= nr_pages
* 2,
4211 .range_start
= start
,
4212 .range_end
= end
+ 1,
4215 while (start
<= end
) {
4216 page
= find_get_page(mapping
, start
>> PAGE_SHIFT
);
4217 if (clear_page_dirty_for_io(page
))
4218 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
4220 btrfs_writepage_endio_finish_ordered(page
, start
,
4221 start
+ PAGE_SIZE
- 1, 1);
4230 end_write_bio(&epd
, ret
);
4233 ret
= flush_write_bio(&epd
);
4237 int extent_writepages(struct address_space
*mapping
,
4238 struct writeback_control
*wbc
)
4241 struct extent_page_data epd
= {
4243 .tree
= &BTRFS_I(mapping
->host
)->io_tree
,
4245 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
4248 ret
= extent_write_cache_pages(mapping
, wbc
, &epd
);
4251 end_write_bio(&epd
, ret
);
4254 ret
= flush_write_bio(&epd
);
4258 int extent_readpages(struct address_space
*mapping
, struct list_head
*pages
,
4261 struct bio
*bio
= NULL
;
4262 unsigned long bio_flags
= 0;
4263 struct page
*pagepool
[16];
4264 struct extent_map
*em_cached
= NULL
;
4265 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
4267 u64 prev_em_start
= (u64
)-1;
4269 while (!list_empty(pages
)) {
4272 for (nr
= 0; nr
< ARRAY_SIZE(pagepool
) && !list_empty(pages
);) {
4273 struct page
*page
= lru_to_page(pages
);
4275 prefetchw(&page
->flags
);
4276 list_del(&page
->lru
);
4277 if (add_to_page_cache_lru(page
, mapping
, page
->index
,
4278 readahead_gfp_mask(mapping
))) {
4283 pagepool
[nr
++] = page
;
4284 contig_end
= page_offset(page
) + PAGE_SIZE
- 1;
4288 u64 contig_start
= page_offset(pagepool
[0]);
4290 ASSERT(contig_start
+ nr
* PAGE_SIZE
- 1 == contig_end
);
4292 contiguous_readpages(tree
, pagepool
, nr
, contig_start
,
4293 contig_end
, &em_cached
, &bio
, &bio_flags
,
4299 free_extent_map(em_cached
);
4302 return submit_one_bio(bio
, 0, bio_flags
);
4307 * basic invalidatepage code, this waits on any locked or writeback
4308 * ranges corresponding to the page, and then deletes any extent state
4309 * records from the tree
4311 int extent_invalidatepage(struct extent_io_tree
*tree
,
4312 struct page
*page
, unsigned long offset
)
4314 struct extent_state
*cached_state
= NULL
;
4315 u64 start
= page_offset(page
);
4316 u64 end
= start
+ PAGE_SIZE
- 1;
4317 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
4319 start
+= ALIGN(offset
, blocksize
);
4323 lock_extent_bits(tree
, start
, end
, &cached_state
);
4324 wait_on_page_writeback(page
);
4325 clear_extent_bit(tree
, start
, end
,
4326 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
4327 EXTENT_DO_ACCOUNTING
,
4328 1, 1, &cached_state
);
4333 * a helper for releasepage, this tests for areas of the page that
4334 * are locked or under IO and drops the related state bits if it is safe
4337 static int try_release_extent_state(struct extent_io_tree
*tree
,
4338 struct page
*page
, gfp_t mask
)
4340 u64 start
= page_offset(page
);
4341 u64 end
= start
+ PAGE_SIZE
- 1;
4344 if (test_range_bit(tree
, start
, end
, EXTENT_LOCKED
, 0, NULL
)) {
4348 * at this point we can safely clear everything except the
4349 * locked bit and the nodatasum bit
4351 ret
= __clear_extent_bit(tree
, start
, end
,
4352 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
4353 0, 0, NULL
, mask
, NULL
);
4355 /* if clear_extent_bit failed for enomem reasons,
4356 * we can't allow the release to continue.
4367 * a helper for releasepage. As long as there are no locked extents
4368 * in the range corresponding to the page, both state records and extent
4369 * map records are removed
4371 int try_release_extent_mapping(struct page
*page
, gfp_t mask
)
4373 struct extent_map
*em
;
4374 u64 start
= page_offset(page
);
4375 u64 end
= start
+ PAGE_SIZE
- 1;
4376 struct btrfs_inode
*btrfs_inode
= BTRFS_I(page
->mapping
->host
);
4377 struct extent_io_tree
*tree
= &btrfs_inode
->io_tree
;
4378 struct extent_map_tree
*map
= &btrfs_inode
->extent_tree
;
4380 if (gfpflags_allow_blocking(mask
) &&
4381 page
->mapping
->host
->i_size
> SZ_16M
) {
4383 while (start
<= end
) {
4384 len
= end
- start
+ 1;
4385 write_lock(&map
->lock
);
4386 em
= lookup_extent_mapping(map
, start
, len
);
4388 write_unlock(&map
->lock
);
4391 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
4392 em
->start
!= start
) {
4393 write_unlock(&map
->lock
);
4394 free_extent_map(em
);
4397 if (!test_range_bit(tree
, em
->start
,
4398 extent_map_end(em
) - 1,
4399 EXTENT_LOCKED
, 0, NULL
)) {
4400 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC
,
4401 &btrfs_inode
->runtime_flags
);
4402 remove_extent_mapping(map
, em
);
4403 /* once for the rb tree */
4404 free_extent_map(em
);
4406 start
= extent_map_end(em
);
4407 write_unlock(&map
->lock
);
4410 free_extent_map(em
);
4413 return try_release_extent_state(tree
, page
, mask
);
4417 * helper function for fiemap, which doesn't want to see any holes.
4418 * This maps until we find something past 'last'
4420 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
4421 u64 offset
, u64 last
)
4423 u64 sectorsize
= btrfs_inode_sectorsize(inode
);
4424 struct extent_map
*em
;
4431 len
= last
- offset
;
4434 len
= ALIGN(len
, sectorsize
);
4435 em
= btrfs_get_extent_fiemap(BTRFS_I(inode
), offset
, len
);
4436 if (IS_ERR_OR_NULL(em
))
4439 /* if this isn't a hole return it */
4440 if (em
->block_start
!= EXTENT_MAP_HOLE
)
4443 /* this is a hole, advance to the next extent */
4444 offset
= extent_map_end(em
);
4445 free_extent_map(em
);
4453 * To cache previous fiemap extent
4455 * Will be used for merging fiemap extent
4457 struct fiemap_cache
{
4466 * Helper to submit fiemap extent.
4468 * Will try to merge current fiemap extent specified by @offset, @phys,
4469 * @len and @flags with cached one.
4470 * And only when we fails to merge, cached one will be submitted as
4473 * Return value is the same as fiemap_fill_next_extent().
4475 static int emit_fiemap_extent(struct fiemap_extent_info
*fieinfo
,
4476 struct fiemap_cache
*cache
,
4477 u64 offset
, u64 phys
, u64 len
, u32 flags
)
4485 * Sanity check, extent_fiemap() should have ensured that new
4486 * fiemap extent won't overlap with cached one.
4489 * NOTE: Physical address can overlap, due to compression
4491 if (cache
->offset
+ cache
->len
> offset
) {
4497 * Only merges fiemap extents if
4498 * 1) Their logical addresses are continuous
4500 * 2) Their physical addresses are continuous
4501 * So truly compressed (physical size smaller than logical size)
4502 * extents won't get merged with each other
4504 * 3) Share same flags except FIEMAP_EXTENT_LAST
4505 * So regular extent won't get merged with prealloc extent
4507 if (cache
->offset
+ cache
->len
== offset
&&
4508 cache
->phys
+ cache
->len
== phys
&&
4509 (cache
->flags
& ~FIEMAP_EXTENT_LAST
) ==
4510 (flags
& ~FIEMAP_EXTENT_LAST
)) {
4512 cache
->flags
|= flags
;
4513 goto try_submit_last
;
4516 /* Not mergeable, need to submit cached one */
4517 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
, cache
->phys
,
4518 cache
->len
, cache
->flags
);
4519 cache
->cached
= false;
4523 cache
->cached
= true;
4524 cache
->offset
= offset
;
4527 cache
->flags
= flags
;
4529 if (cache
->flags
& FIEMAP_EXTENT_LAST
) {
4530 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
,
4531 cache
->phys
, cache
->len
, cache
->flags
);
4532 cache
->cached
= false;
4538 * Emit last fiemap cache
4540 * The last fiemap cache may still be cached in the following case:
4542 * |<- Fiemap range ->|
4543 * |<------------ First extent ----------->|
4545 * In this case, the first extent range will be cached but not emitted.
4546 * So we must emit it before ending extent_fiemap().
4548 static int emit_last_fiemap_cache(struct fiemap_extent_info
*fieinfo
,
4549 struct fiemap_cache
*cache
)
4556 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
, cache
->phys
,
4557 cache
->len
, cache
->flags
);
4558 cache
->cached
= false;
4564 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4565 __u64 start
, __u64 len
)
4569 u64 max
= start
+ len
;
4573 u64 last_for_get_extent
= 0;
4575 u64 isize
= i_size_read(inode
);
4576 struct btrfs_key found_key
;
4577 struct extent_map
*em
= NULL
;
4578 struct extent_state
*cached_state
= NULL
;
4579 struct btrfs_path
*path
;
4580 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4581 struct fiemap_cache cache
= { 0 };
4582 struct ulist
*roots
;
4583 struct ulist
*tmp_ulist
;
4592 path
= btrfs_alloc_path();
4595 path
->leave_spinning
= 1;
4597 roots
= ulist_alloc(GFP_KERNEL
);
4598 tmp_ulist
= ulist_alloc(GFP_KERNEL
);
4599 if (!roots
|| !tmp_ulist
) {
4601 goto out_free_ulist
;
4604 start
= round_down(start
, btrfs_inode_sectorsize(inode
));
4605 len
= round_up(max
, btrfs_inode_sectorsize(inode
)) - start
;
4608 * lookup the last file extent. We're not using i_size here
4609 * because there might be preallocation past i_size
4611 ret
= btrfs_lookup_file_extent(NULL
, root
, path
,
4612 btrfs_ino(BTRFS_I(inode
)), -1, 0);
4614 btrfs_free_path(path
);
4615 goto out_free_ulist
;
4623 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
4624 found_type
= found_key
.type
;
4626 /* No extents, but there might be delalloc bits */
4627 if (found_key
.objectid
!= btrfs_ino(BTRFS_I(inode
)) ||
4628 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
4629 /* have to trust i_size as the end */
4631 last_for_get_extent
= isize
;
4634 * remember the start of the last extent. There are a
4635 * bunch of different factors that go into the length of the
4636 * extent, so its much less complex to remember where it started
4638 last
= found_key
.offset
;
4639 last_for_get_extent
= last
+ 1;
4641 btrfs_release_path(path
);
4644 * we might have some extents allocated but more delalloc past those
4645 * extents. so, we trust isize unless the start of the last extent is
4650 last_for_get_extent
= isize
;
4653 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4656 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
);
4665 u64 offset_in_extent
= 0;
4667 /* break if the extent we found is outside the range */
4668 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4672 * get_extent may return an extent that starts before our
4673 * requested range. We have to make sure the ranges
4674 * we return to fiemap always move forward and don't
4675 * overlap, so adjust the offsets here
4677 em_start
= max(em
->start
, off
);
4680 * record the offset from the start of the extent
4681 * for adjusting the disk offset below. Only do this if the
4682 * extent isn't compressed since our in ram offset may be past
4683 * what we have actually allocated on disk.
4685 if (!test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4686 offset_in_extent
= em_start
- em
->start
;
4687 em_end
= extent_map_end(em
);
4688 em_len
= em_end
- em_start
;
4690 if (em
->block_start
< EXTENT_MAP_LAST_BYTE
)
4691 disko
= em
->block_start
+ offset_in_extent
;
4696 * bump off for our next call to get_extent
4698 off
= extent_map_end(em
);
4702 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4704 flags
|= FIEMAP_EXTENT_LAST
;
4705 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4706 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4707 FIEMAP_EXTENT_NOT_ALIGNED
);
4708 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4709 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4710 FIEMAP_EXTENT_UNKNOWN
);
4711 } else if (fieinfo
->fi_extents_max
) {
4712 u64 bytenr
= em
->block_start
-
4713 (em
->start
- em
->orig_start
);
4716 * As btrfs supports shared space, this information
4717 * can be exported to userspace tools via
4718 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4719 * then we're just getting a count and we can skip the
4722 ret
= btrfs_check_shared(root
,
4723 btrfs_ino(BTRFS_I(inode
)),
4724 bytenr
, roots
, tmp_ulist
);
4728 flags
|= FIEMAP_EXTENT_SHARED
;
4731 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4732 flags
|= FIEMAP_EXTENT_ENCODED
;
4733 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
4734 flags
|= FIEMAP_EXTENT_UNWRITTEN
;
4736 free_extent_map(em
);
4738 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4739 (last
== (u64
)-1 && isize
<= em_end
)) {
4740 flags
|= FIEMAP_EXTENT_LAST
;
4744 /* now scan forward to see if this is really the last extent. */
4745 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
);
4751 flags
|= FIEMAP_EXTENT_LAST
;
4754 ret
= emit_fiemap_extent(fieinfo
, &cache
, em_start
, disko
,
4764 ret
= emit_last_fiemap_cache(fieinfo
, &cache
);
4765 free_extent_map(em
);
4767 btrfs_free_path(path
);
4768 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4773 ulist_free(tmp_ulist
);
4777 static void __free_extent_buffer(struct extent_buffer
*eb
)
4779 btrfs_leak_debug_del(&eb
->leak_list
);
4780 kmem_cache_free(extent_buffer_cache
, eb
);
4783 int extent_buffer_under_io(struct extent_buffer
*eb
)
4785 return (atomic_read(&eb
->io_pages
) ||
4786 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4787 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4791 * Release all pages attached to the extent buffer.
4793 static void btrfs_release_extent_buffer_pages(struct extent_buffer
*eb
)
4797 int mapped
= !test_bit(EXTENT_BUFFER_UNMAPPED
, &eb
->bflags
);
4799 BUG_ON(extent_buffer_under_io(eb
));
4801 num_pages
= num_extent_pages(eb
);
4802 for (i
= 0; i
< num_pages
; i
++) {
4803 struct page
*page
= eb
->pages
[i
];
4808 spin_lock(&page
->mapping
->private_lock
);
4810 * We do this since we'll remove the pages after we've
4811 * removed the eb from the radix tree, so we could race
4812 * and have this page now attached to the new eb. So
4813 * only clear page_private if it's still connected to
4816 if (PagePrivate(page
) &&
4817 page
->private == (unsigned long)eb
) {
4818 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4819 BUG_ON(PageDirty(page
));
4820 BUG_ON(PageWriteback(page
));
4822 * We need to make sure we haven't be attached
4825 ClearPagePrivate(page
);
4826 set_page_private(page
, 0);
4827 /* One for the page private */
4832 spin_unlock(&page
->mapping
->private_lock
);
4834 /* One for when we allocated the page */
4840 * Helper for releasing the extent buffer.
4842 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4844 btrfs_release_extent_buffer_pages(eb
);
4845 __free_extent_buffer(eb
);
4848 static struct extent_buffer
*
4849 __alloc_extent_buffer(struct btrfs_fs_info
*fs_info
, u64 start
,
4852 struct extent_buffer
*eb
= NULL
;
4854 eb
= kmem_cache_zalloc(extent_buffer_cache
, GFP_NOFS
|__GFP_NOFAIL
);
4857 eb
->fs_info
= fs_info
;
4859 rwlock_init(&eb
->lock
);
4860 atomic_set(&eb
->blocking_readers
, 0);
4861 eb
->blocking_writers
= 0;
4862 eb
->lock_nested
= false;
4863 init_waitqueue_head(&eb
->write_lock_wq
);
4864 init_waitqueue_head(&eb
->read_lock_wq
);
4866 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4868 spin_lock_init(&eb
->refs_lock
);
4869 atomic_set(&eb
->refs
, 1);
4870 atomic_set(&eb
->io_pages
, 0);
4873 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4875 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4876 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4877 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4879 #ifdef CONFIG_BTRFS_DEBUG
4880 eb
->spinning_writers
= 0;
4881 atomic_set(&eb
->spinning_readers
, 0);
4882 atomic_set(&eb
->read_locks
, 0);
4883 eb
->write_locks
= 0;
4889 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4893 struct extent_buffer
*new;
4894 int num_pages
= num_extent_pages(src
);
4896 new = __alloc_extent_buffer(src
->fs_info
, src
->start
, src
->len
);
4900 for (i
= 0; i
< num_pages
; i
++) {
4901 p
= alloc_page(GFP_NOFS
);
4903 btrfs_release_extent_buffer(new);
4906 attach_extent_buffer_page(new, p
);
4907 WARN_ON(PageDirty(p
));
4910 copy_page(page_address(p
), page_address(src
->pages
[i
]));
4913 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4914 set_bit(EXTENT_BUFFER_UNMAPPED
, &new->bflags
);
4919 struct extent_buffer
*__alloc_dummy_extent_buffer(struct btrfs_fs_info
*fs_info
,
4920 u64 start
, unsigned long len
)
4922 struct extent_buffer
*eb
;
4926 eb
= __alloc_extent_buffer(fs_info
, start
, len
);
4930 num_pages
= num_extent_pages(eb
);
4931 for (i
= 0; i
< num_pages
; i
++) {
4932 eb
->pages
[i
] = alloc_page(GFP_NOFS
);
4936 set_extent_buffer_uptodate(eb
);
4937 btrfs_set_header_nritems(eb
, 0);
4938 set_bit(EXTENT_BUFFER_UNMAPPED
, &eb
->bflags
);
4943 __free_page(eb
->pages
[i
- 1]);
4944 __free_extent_buffer(eb
);
4948 struct extent_buffer
*alloc_dummy_extent_buffer(struct btrfs_fs_info
*fs_info
,
4951 return __alloc_dummy_extent_buffer(fs_info
, start
, fs_info
->nodesize
);
4954 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4957 /* the ref bit is tricky. We have to make sure it is set
4958 * if we have the buffer dirty. Otherwise the
4959 * code to free a buffer can end up dropping a dirty
4962 * Once the ref bit is set, it won't go away while the
4963 * buffer is dirty or in writeback, and it also won't
4964 * go away while we have the reference count on the
4967 * We can't just set the ref bit without bumping the
4968 * ref on the eb because free_extent_buffer might
4969 * see the ref bit and try to clear it. If this happens
4970 * free_extent_buffer might end up dropping our original
4971 * ref by mistake and freeing the page before we are able
4972 * to add one more ref.
4974 * So bump the ref count first, then set the bit. If someone
4975 * beat us to it, drop the ref we added.
4977 refs
= atomic_read(&eb
->refs
);
4978 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4981 spin_lock(&eb
->refs_lock
);
4982 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4983 atomic_inc(&eb
->refs
);
4984 spin_unlock(&eb
->refs_lock
);
4987 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
,
4988 struct page
*accessed
)
4992 check_buffer_tree_ref(eb
);
4994 num_pages
= num_extent_pages(eb
);
4995 for (i
= 0; i
< num_pages
; i
++) {
4996 struct page
*p
= eb
->pages
[i
];
4999 mark_page_accessed(p
);
5003 struct extent_buffer
*find_extent_buffer(struct btrfs_fs_info
*fs_info
,
5006 struct extent_buffer
*eb
;
5009 eb
= radix_tree_lookup(&fs_info
->buffer_radix
,
5010 start
>> PAGE_SHIFT
);
5011 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
5014 * Lock our eb's refs_lock to avoid races with
5015 * free_extent_buffer. When we get our eb it might be flagged
5016 * with EXTENT_BUFFER_STALE and another task running
5017 * free_extent_buffer might have seen that flag set,
5018 * eb->refs == 2, that the buffer isn't under IO (dirty and
5019 * writeback flags not set) and it's still in the tree (flag
5020 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
5021 * of decrementing the extent buffer's reference count twice.
5022 * So here we could race and increment the eb's reference count,
5023 * clear its stale flag, mark it as dirty and drop our reference
5024 * before the other task finishes executing free_extent_buffer,
5025 * which would later result in an attempt to free an extent
5026 * buffer that is dirty.
5028 if (test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
)) {
5029 spin_lock(&eb
->refs_lock
);
5030 spin_unlock(&eb
->refs_lock
);
5032 mark_extent_buffer_accessed(eb
, NULL
);
5040 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5041 struct extent_buffer
*alloc_test_extent_buffer(struct btrfs_fs_info
*fs_info
,
5044 struct extent_buffer
*eb
, *exists
= NULL
;
5047 eb
= find_extent_buffer(fs_info
, start
);
5050 eb
= alloc_dummy_extent_buffer(fs_info
, start
);
5053 eb
->fs_info
= fs_info
;
5055 ret
= radix_tree_preload(GFP_NOFS
);
5058 spin_lock(&fs_info
->buffer_lock
);
5059 ret
= radix_tree_insert(&fs_info
->buffer_radix
,
5060 start
>> PAGE_SHIFT
, eb
);
5061 spin_unlock(&fs_info
->buffer_lock
);
5062 radix_tree_preload_end();
5063 if (ret
== -EEXIST
) {
5064 exists
= find_extent_buffer(fs_info
, start
);
5070 check_buffer_tree_ref(eb
);
5071 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
5075 btrfs_release_extent_buffer(eb
);
5080 struct extent_buffer
*alloc_extent_buffer(struct btrfs_fs_info
*fs_info
,
5083 unsigned long len
= fs_info
->nodesize
;
5086 unsigned long index
= start
>> PAGE_SHIFT
;
5087 struct extent_buffer
*eb
;
5088 struct extent_buffer
*exists
= NULL
;
5090 struct address_space
*mapping
= fs_info
->btree_inode
->i_mapping
;
5094 if (!IS_ALIGNED(start
, fs_info
->sectorsize
)) {
5095 btrfs_err(fs_info
, "bad tree block start %llu", start
);
5096 return ERR_PTR(-EINVAL
);
5099 eb
= find_extent_buffer(fs_info
, start
);
5103 eb
= __alloc_extent_buffer(fs_info
, start
, len
);
5105 return ERR_PTR(-ENOMEM
);
5107 num_pages
= num_extent_pages(eb
);
5108 for (i
= 0; i
< num_pages
; i
++, index
++) {
5109 p
= find_or_create_page(mapping
, index
, GFP_NOFS
|__GFP_NOFAIL
);
5111 exists
= ERR_PTR(-ENOMEM
);
5115 spin_lock(&mapping
->private_lock
);
5116 if (PagePrivate(p
)) {
5118 * We could have already allocated an eb for this page
5119 * and attached one so lets see if we can get a ref on
5120 * the existing eb, and if we can we know it's good and
5121 * we can just return that one, else we know we can just
5122 * overwrite page->private.
5124 exists
= (struct extent_buffer
*)p
->private;
5125 if (atomic_inc_not_zero(&exists
->refs
)) {
5126 spin_unlock(&mapping
->private_lock
);
5129 mark_extent_buffer_accessed(exists
, p
);
5135 * Do this so attach doesn't complain and we need to
5136 * drop the ref the old guy had.
5138 ClearPagePrivate(p
);
5139 WARN_ON(PageDirty(p
));
5142 attach_extent_buffer_page(eb
, p
);
5143 spin_unlock(&mapping
->private_lock
);
5144 WARN_ON(PageDirty(p
));
5146 if (!PageUptodate(p
))
5150 * We can't unlock the pages just yet since the extent buffer
5151 * hasn't been properly inserted in the radix tree, this
5152 * opens a race with btree_releasepage which can free a page
5153 * while we are still filling in all pages for the buffer and
5158 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5160 ret
= radix_tree_preload(GFP_NOFS
);
5162 exists
= ERR_PTR(ret
);
5166 spin_lock(&fs_info
->buffer_lock
);
5167 ret
= radix_tree_insert(&fs_info
->buffer_radix
,
5168 start
>> PAGE_SHIFT
, eb
);
5169 spin_unlock(&fs_info
->buffer_lock
);
5170 radix_tree_preload_end();
5171 if (ret
== -EEXIST
) {
5172 exists
= find_extent_buffer(fs_info
, start
);
5178 /* add one reference for the tree */
5179 check_buffer_tree_ref(eb
);
5180 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
5183 * Now it's safe to unlock the pages because any calls to
5184 * btree_releasepage will correctly detect that a page belongs to a
5185 * live buffer and won't free them prematurely.
5187 for (i
= 0; i
< num_pages
; i
++)
5188 unlock_page(eb
->pages
[i
]);
5192 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
5193 for (i
= 0; i
< num_pages
; i
++) {
5195 unlock_page(eb
->pages
[i
]);
5198 btrfs_release_extent_buffer(eb
);
5202 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
5204 struct extent_buffer
*eb
=
5205 container_of(head
, struct extent_buffer
, rcu_head
);
5207 __free_extent_buffer(eb
);
5210 static int release_extent_buffer(struct extent_buffer
*eb
)
5212 lockdep_assert_held(&eb
->refs_lock
);
5214 WARN_ON(atomic_read(&eb
->refs
) == 0);
5215 if (atomic_dec_and_test(&eb
->refs
)) {
5216 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
)) {
5217 struct btrfs_fs_info
*fs_info
= eb
->fs_info
;
5219 spin_unlock(&eb
->refs_lock
);
5221 spin_lock(&fs_info
->buffer_lock
);
5222 radix_tree_delete(&fs_info
->buffer_radix
,
5223 eb
->start
>> PAGE_SHIFT
);
5224 spin_unlock(&fs_info
->buffer_lock
);
5226 spin_unlock(&eb
->refs_lock
);
5229 /* Should be safe to release our pages at this point */
5230 btrfs_release_extent_buffer_pages(eb
);
5231 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5232 if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED
, &eb
->bflags
))) {
5233 __free_extent_buffer(eb
);
5237 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
5240 spin_unlock(&eb
->refs_lock
);
5245 void free_extent_buffer(struct extent_buffer
*eb
)
5253 refs
= atomic_read(&eb
->refs
);
5254 if ((!test_bit(EXTENT_BUFFER_UNMAPPED
, &eb
->bflags
) && refs
<= 3)
5255 || (test_bit(EXTENT_BUFFER_UNMAPPED
, &eb
->bflags
) &&
5258 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
5263 spin_lock(&eb
->refs_lock
);
5264 if (atomic_read(&eb
->refs
) == 2 &&
5265 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
5266 !extent_buffer_under_io(eb
) &&
5267 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
5268 atomic_dec(&eb
->refs
);
5271 * I know this is terrible, but it's temporary until we stop tracking
5272 * the uptodate bits and such for the extent buffers.
5274 release_extent_buffer(eb
);
5277 void free_extent_buffer_stale(struct extent_buffer
*eb
)
5282 spin_lock(&eb
->refs_lock
);
5283 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
5285 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
5286 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
5287 atomic_dec(&eb
->refs
);
5288 release_extent_buffer(eb
);
5291 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
5297 num_pages
= num_extent_pages(eb
);
5299 for (i
= 0; i
< num_pages
; i
++) {
5300 page
= eb
->pages
[i
];
5301 if (!PageDirty(page
))
5305 WARN_ON(!PagePrivate(page
));
5307 clear_page_dirty_for_io(page
);
5308 xa_lock_irq(&page
->mapping
->i_pages
);
5309 if (!PageDirty(page
))
5310 __xa_clear_mark(&page
->mapping
->i_pages
,
5311 page_index(page
), PAGECACHE_TAG_DIRTY
);
5312 xa_unlock_irq(&page
->mapping
->i_pages
);
5313 ClearPageError(page
);
5316 WARN_ON(atomic_read(&eb
->refs
) == 0);
5319 bool set_extent_buffer_dirty(struct extent_buffer
*eb
)
5325 check_buffer_tree_ref(eb
);
5327 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
5329 num_pages
= num_extent_pages(eb
);
5330 WARN_ON(atomic_read(&eb
->refs
) == 0);
5331 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
5334 for (i
= 0; i
< num_pages
; i
++)
5335 set_page_dirty(eb
->pages
[i
]);
5337 #ifdef CONFIG_BTRFS_DEBUG
5338 for (i
= 0; i
< num_pages
; i
++)
5339 ASSERT(PageDirty(eb
->pages
[i
]));
5345 void clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
5351 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5352 num_pages
= num_extent_pages(eb
);
5353 for (i
= 0; i
< num_pages
; i
++) {
5354 page
= eb
->pages
[i
];
5356 ClearPageUptodate(page
);
5360 void set_extent_buffer_uptodate(struct extent_buffer
*eb
)
5366 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5367 num_pages
= num_extent_pages(eb
);
5368 for (i
= 0; i
< num_pages
; i
++) {
5369 page
= eb
->pages
[i
];
5370 SetPageUptodate(page
);
5374 int read_extent_buffer_pages(struct extent_buffer
*eb
, int wait
, int mirror_num
)
5380 int locked_pages
= 0;
5381 int all_uptodate
= 1;
5383 unsigned long num_reads
= 0;
5384 struct bio
*bio
= NULL
;
5385 unsigned long bio_flags
= 0;
5386 struct extent_io_tree
*tree
= &BTRFS_I(eb
->fs_info
->btree_inode
)->io_tree
;
5388 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
5391 num_pages
= num_extent_pages(eb
);
5392 for (i
= 0; i
< num_pages
; i
++) {
5393 page
= eb
->pages
[i
];
5394 if (wait
== WAIT_NONE
) {
5395 if (!trylock_page(page
))
5403 * We need to firstly lock all pages to make sure that
5404 * the uptodate bit of our pages won't be affected by
5405 * clear_extent_buffer_uptodate().
5407 for (i
= 0; i
< num_pages
; i
++) {
5408 page
= eb
->pages
[i
];
5409 if (!PageUptodate(page
)) {
5416 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5420 clear_bit(EXTENT_BUFFER_READ_ERR
, &eb
->bflags
);
5421 eb
->read_mirror
= 0;
5422 atomic_set(&eb
->io_pages
, num_reads
);
5423 for (i
= 0; i
< num_pages
; i
++) {
5424 page
= eb
->pages
[i
];
5426 if (!PageUptodate(page
)) {
5428 atomic_dec(&eb
->io_pages
);
5433 ClearPageError(page
);
5434 err
= __extent_read_full_page(tree
, page
,
5435 btree_get_extent
, &bio
,
5436 mirror_num
, &bio_flags
,
5441 * We use &bio in above __extent_read_full_page,
5442 * so we ensure that if it returns error, the
5443 * current page fails to add itself to bio and
5444 * it's been unlocked.
5446 * We must dec io_pages by ourselves.
5448 atomic_dec(&eb
->io_pages
);
5456 err
= submit_one_bio(bio
, mirror_num
, bio_flags
);
5461 if (ret
|| wait
!= WAIT_COMPLETE
)
5464 for (i
= 0; i
< num_pages
; i
++) {
5465 page
= eb
->pages
[i
];
5466 wait_on_page_locked(page
);
5467 if (!PageUptodate(page
))
5474 while (locked_pages
> 0) {
5476 page
= eb
->pages
[locked_pages
];
5482 void read_extent_buffer(const struct extent_buffer
*eb
, void *dstv
,
5483 unsigned long start
, unsigned long len
)
5489 char *dst
= (char *)dstv
;
5490 size_t start_offset
= offset_in_page(eb
->start
);
5491 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5493 if (start
+ len
> eb
->len
) {
5494 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5495 eb
->start
, eb
->len
, start
, len
);
5496 memset(dst
, 0, len
);
5500 offset
= offset_in_page(start_offset
+ start
);
5503 page
= eb
->pages
[i
];
5505 cur
= min(len
, (PAGE_SIZE
- offset
));
5506 kaddr
= page_address(page
);
5507 memcpy(dst
, kaddr
+ offset
, cur
);
5516 int read_extent_buffer_to_user(const struct extent_buffer
*eb
,
5518 unsigned long start
, unsigned long len
)
5524 char __user
*dst
= (char __user
*)dstv
;
5525 size_t start_offset
= offset_in_page(eb
->start
);
5526 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5529 WARN_ON(start
> eb
->len
);
5530 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5532 offset
= offset_in_page(start_offset
+ start
);
5535 page
= eb
->pages
[i
];
5537 cur
= min(len
, (PAGE_SIZE
- offset
));
5538 kaddr
= page_address(page
);
5539 if (copy_to_user(dst
, kaddr
+ offset
, cur
)) {
5554 * return 0 if the item is found within a page.
5555 * return 1 if the item spans two pages.
5556 * return -EINVAL otherwise.
5558 int map_private_extent_buffer(const struct extent_buffer
*eb
,
5559 unsigned long start
, unsigned long min_len
,
5560 char **map
, unsigned long *map_start
,
5561 unsigned long *map_len
)
5566 size_t start_offset
= offset_in_page(eb
->start
);
5567 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5568 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
5571 if (start
+ min_len
> eb
->len
) {
5572 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5573 eb
->start
, eb
->len
, start
, min_len
);
5581 offset
= start_offset
;
5585 *map_start
= ((u64
)i
<< PAGE_SHIFT
) - start_offset
;
5589 kaddr
= page_address(p
);
5590 *map
= kaddr
+ offset
;
5591 *map_len
= PAGE_SIZE
- offset
;
5595 int memcmp_extent_buffer(const struct extent_buffer
*eb
, const void *ptrv
,
5596 unsigned long start
, unsigned long len
)
5602 char *ptr
= (char *)ptrv
;
5603 size_t start_offset
= offset_in_page(eb
->start
);
5604 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5607 WARN_ON(start
> eb
->len
);
5608 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5610 offset
= offset_in_page(start_offset
+ start
);
5613 page
= eb
->pages
[i
];
5615 cur
= min(len
, (PAGE_SIZE
- offset
));
5617 kaddr
= page_address(page
);
5618 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
5630 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer
*eb
,
5635 WARN_ON(!PageUptodate(eb
->pages
[0]));
5636 kaddr
= page_address(eb
->pages
[0]);
5637 memcpy(kaddr
+ offsetof(struct btrfs_header
, chunk_tree_uuid
), srcv
,
5641 void write_extent_buffer_fsid(struct extent_buffer
*eb
, const void *srcv
)
5645 WARN_ON(!PageUptodate(eb
->pages
[0]));
5646 kaddr
= page_address(eb
->pages
[0]);
5647 memcpy(kaddr
+ offsetof(struct btrfs_header
, fsid
), srcv
,
5651 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
5652 unsigned long start
, unsigned long len
)
5658 char *src
= (char *)srcv
;
5659 size_t start_offset
= offset_in_page(eb
->start
);
5660 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5662 WARN_ON(start
> eb
->len
);
5663 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5665 offset
= offset_in_page(start_offset
+ start
);
5668 page
= eb
->pages
[i
];
5669 WARN_ON(!PageUptodate(page
));
5671 cur
= min(len
, PAGE_SIZE
- offset
);
5672 kaddr
= page_address(page
);
5673 memcpy(kaddr
+ offset
, src
, cur
);
5682 void memzero_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
5689 size_t start_offset
= offset_in_page(eb
->start
);
5690 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5692 WARN_ON(start
> eb
->len
);
5693 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5695 offset
= offset_in_page(start_offset
+ start
);
5698 page
= eb
->pages
[i
];
5699 WARN_ON(!PageUptodate(page
));
5701 cur
= min(len
, PAGE_SIZE
- offset
);
5702 kaddr
= page_address(page
);
5703 memset(kaddr
+ offset
, 0, cur
);
5711 void copy_extent_buffer_full(struct extent_buffer
*dst
,
5712 struct extent_buffer
*src
)
5717 ASSERT(dst
->len
== src
->len
);
5719 num_pages
= num_extent_pages(dst
);
5720 for (i
= 0; i
< num_pages
; i
++)
5721 copy_page(page_address(dst
->pages
[i
]),
5722 page_address(src
->pages
[i
]));
5725 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
5726 unsigned long dst_offset
, unsigned long src_offset
,
5729 u64 dst_len
= dst
->len
;
5734 size_t start_offset
= offset_in_page(dst
->start
);
5735 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_SHIFT
;
5737 WARN_ON(src
->len
!= dst_len
);
5739 offset
= offset_in_page(start_offset
+ dst_offset
);
5742 page
= dst
->pages
[i
];
5743 WARN_ON(!PageUptodate(page
));
5745 cur
= min(len
, (unsigned long)(PAGE_SIZE
- offset
));
5747 kaddr
= page_address(page
);
5748 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
5758 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5760 * @eb: the extent buffer
5761 * @start: offset of the bitmap item in the extent buffer
5763 * @page_index: return index of the page in the extent buffer that contains the
5765 * @page_offset: return offset into the page given by page_index
5767 * This helper hides the ugliness of finding the byte in an extent buffer which
5768 * contains a given bit.
5770 static inline void eb_bitmap_offset(struct extent_buffer
*eb
,
5771 unsigned long start
, unsigned long nr
,
5772 unsigned long *page_index
,
5773 size_t *page_offset
)
5775 size_t start_offset
= offset_in_page(eb
->start
);
5776 size_t byte_offset
= BIT_BYTE(nr
);
5780 * The byte we want is the offset of the extent buffer + the offset of
5781 * the bitmap item in the extent buffer + the offset of the byte in the
5784 offset
= start_offset
+ start
+ byte_offset
;
5786 *page_index
= offset
>> PAGE_SHIFT
;
5787 *page_offset
= offset_in_page(offset
);
5791 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5792 * @eb: the extent buffer
5793 * @start: offset of the bitmap item in the extent buffer
5794 * @nr: bit number to test
5796 int extent_buffer_test_bit(struct extent_buffer
*eb
, unsigned long start
,
5804 eb_bitmap_offset(eb
, start
, nr
, &i
, &offset
);
5805 page
= eb
->pages
[i
];
5806 WARN_ON(!PageUptodate(page
));
5807 kaddr
= page_address(page
);
5808 return 1U & (kaddr
[offset
] >> (nr
& (BITS_PER_BYTE
- 1)));
5812 * extent_buffer_bitmap_set - set an area of a bitmap
5813 * @eb: the extent buffer
5814 * @start: offset of the bitmap item in the extent buffer
5815 * @pos: bit number of the first bit
5816 * @len: number of bits to set
5818 void extent_buffer_bitmap_set(struct extent_buffer
*eb
, unsigned long start
,
5819 unsigned long pos
, unsigned long len
)
5825 const unsigned int size
= pos
+ len
;
5826 int bits_to_set
= BITS_PER_BYTE
- (pos
% BITS_PER_BYTE
);
5827 u8 mask_to_set
= BITMAP_FIRST_BYTE_MASK(pos
);
5829 eb_bitmap_offset(eb
, start
, pos
, &i
, &offset
);
5830 page
= eb
->pages
[i
];
5831 WARN_ON(!PageUptodate(page
));
5832 kaddr
= page_address(page
);
5834 while (len
>= bits_to_set
) {
5835 kaddr
[offset
] |= mask_to_set
;
5837 bits_to_set
= BITS_PER_BYTE
;
5839 if (++offset
>= PAGE_SIZE
&& len
> 0) {
5841 page
= eb
->pages
[++i
];
5842 WARN_ON(!PageUptodate(page
));
5843 kaddr
= page_address(page
);
5847 mask_to_set
&= BITMAP_LAST_BYTE_MASK(size
);
5848 kaddr
[offset
] |= mask_to_set
;
5854 * extent_buffer_bitmap_clear - clear an area of a bitmap
5855 * @eb: the extent buffer
5856 * @start: offset of the bitmap item in the extent buffer
5857 * @pos: bit number of the first bit
5858 * @len: number of bits to clear
5860 void extent_buffer_bitmap_clear(struct extent_buffer
*eb
, unsigned long start
,
5861 unsigned long pos
, unsigned long len
)
5867 const unsigned int size
= pos
+ len
;
5868 int bits_to_clear
= BITS_PER_BYTE
- (pos
% BITS_PER_BYTE
);
5869 u8 mask_to_clear
= BITMAP_FIRST_BYTE_MASK(pos
);
5871 eb_bitmap_offset(eb
, start
, pos
, &i
, &offset
);
5872 page
= eb
->pages
[i
];
5873 WARN_ON(!PageUptodate(page
));
5874 kaddr
= page_address(page
);
5876 while (len
>= bits_to_clear
) {
5877 kaddr
[offset
] &= ~mask_to_clear
;
5878 len
-= bits_to_clear
;
5879 bits_to_clear
= BITS_PER_BYTE
;
5881 if (++offset
>= PAGE_SIZE
&& len
> 0) {
5883 page
= eb
->pages
[++i
];
5884 WARN_ON(!PageUptodate(page
));
5885 kaddr
= page_address(page
);
5889 mask_to_clear
&= BITMAP_LAST_BYTE_MASK(size
);
5890 kaddr
[offset
] &= ~mask_to_clear
;
5894 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
5896 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
5897 return distance
< len
;
5900 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
5901 unsigned long dst_off
, unsigned long src_off
,
5904 char *dst_kaddr
= page_address(dst_page
);
5906 int must_memmove
= 0;
5908 if (dst_page
!= src_page
) {
5909 src_kaddr
= page_address(src_page
);
5911 src_kaddr
= dst_kaddr
;
5912 if (areas_overlap(src_off
, dst_off
, len
))
5917 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5919 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5922 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5923 unsigned long src_offset
, unsigned long len
)
5925 struct btrfs_fs_info
*fs_info
= dst
->fs_info
;
5927 size_t dst_off_in_page
;
5928 size_t src_off_in_page
;
5929 size_t start_offset
= offset_in_page(dst
->start
);
5930 unsigned long dst_i
;
5931 unsigned long src_i
;
5933 if (src_offset
+ len
> dst
->len
) {
5935 "memmove bogus src_offset %lu move len %lu dst len %lu",
5936 src_offset
, len
, dst
->len
);
5939 if (dst_offset
+ len
> dst
->len
) {
5941 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5942 dst_offset
, len
, dst
->len
);
5947 dst_off_in_page
= offset_in_page(start_offset
+ dst_offset
);
5948 src_off_in_page
= offset_in_page(start_offset
+ src_offset
);
5950 dst_i
= (start_offset
+ dst_offset
) >> PAGE_SHIFT
;
5951 src_i
= (start_offset
+ src_offset
) >> PAGE_SHIFT
;
5953 cur
= min(len
, (unsigned long)(PAGE_SIZE
-
5955 cur
= min_t(unsigned long, cur
,
5956 (unsigned long)(PAGE_SIZE
- dst_off_in_page
));
5958 copy_pages(dst
->pages
[dst_i
], dst
->pages
[src_i
],
5959 dst_off_in_page
, src_off_in_page
, cur
);
5967 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5968 unsigned long src_offset
, unsigned long len
)
5970 struct btrfs_fs_info
*fs_info
= dst
->fs_info
;
5972 size_t dst_off_in_page
;
5973 size_t src_off_in_page
;
5974 unsigned long dst_end
= dst_offset
+ len
- 1;
5975 unsigned long src_end
= src_offset
+ len
- 1;
5976 size_t start_offset
= offset_in_page(dst
->start
);
5977 unsigned long dst_i
;
5978 unsigned long src_i
;
5980 if (src_offset
+ len
> dst
->len
) {
5982 "memmove bogus src_offset %lu move len %lu len %lu",
5983 src_offset
, len
, dst
->len
);
5986 if (dst_offset
+ len
> dst
->len
) {
5988 "memmove bogus dst_offset %lu move len %lu len %lu",
5989 dst_offset
, len
, dst
->len
);
5992 if (dst_offset
< src_offset
) {
5993 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5997 dst_i
= (start_offset
+ dst_end
) >> PAGE_SHIFT
;
5998 src_i
= (start_offset
+ src_end
) >> PAGE_SHIFT
;
6000 dst_off_in_page
= offset_in_page(start_offset
+ dst_end
);
6001 src_off_in_page
= offset_in_page(start_offset
+ src_end
);
6003 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
6004 cur
= min(cur
, dst_off_in_page
+ 1);
6005 copy_pages(dst
->pages
[dst_i
], dst
->pages
[src_i
],
6006 dst_off_in_page
- cur
+ 1,
6007 src_off_in_page
- cur
+ 1, cur
);
6015 int try_release_extent_buffer(struct page
*page
)
6017 struct extent_buffer
*eb
;
6020 * We need to make sure nobody is attaching this page to an eb right
6023 spin_lock(&page
->mapping
->private_lock
);
6024 if (!PagePrivate(page
)) {
6025 spin_unlock(&page
->mapping
->private_lock
);
6029 eb
= (struct extent_buffer
*)page
->private;
6033 * This is a little awful but should be ok, we need to make sure that
6034 * the eb doesn't disappear out from under us while we're looking at
6037 spin_lock(&eb
->refs_lock
);
6038 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
6039 spin_unlock(&eb
->refs_lock
);
6040 spin_unlock(&page
->mapping
->private_lock
);
6043 spin_unlock(&page
->mapping
->private_lock
);
6046 * If tree ref isn't set then we know the ref on this eb is a real ref,
6047 * so just return, this page will likely be freed soon anyway.
6049 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
6050 spin_unlock(&eb
->refs_lock
);
6054 return release_extent_buffer(eb
);