1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/spinlock.h>
8 #include <linux/blkdev.h>
9 #include <linux/swap.h>
10 #include <linux/writeback.h>
11 #include <linux/pagevec.h>
12 #include <linux/prefetch.h>
13 #include <linux/cleancache.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
17 #include "btrfs_inode.h"
19 #include "check-integrity.h"
21 #include "rcu-string.h"
23 #include "transaction.h"
25 static struct kmem_cache
*extent_state_cache
;
26 static struct kmem_cache
*extent_buffer_cache
;
27 static struct bio_set
*btrfs_bioset
;
29 static inline bool extent_state_in_tree(const struct extent_state
*state
)
31 return !RB_EMPTY_NODE(&state
->rb_node
);
34 #ifdef CONFIG_BTRFS_DEBUG
35 static LIST_HEAD(buffers
);
36 static LIST_HEAD(states
);
38 static DEFINE_SPINLOCK(leak_lock
);
41 void btrfs_leak_debug_add(struct list_head
*new, struct list_head
*head
)
45 spin_lock_irqsave(&leak_lock
, flags
);
47 spin_unlock_irqrestore(&leak_lock
, flags
);
51 void btrfs_leak_debug_del(struct list_head
*entry
)
55 spin_lock_irqsave(&leak_lock
, flags
);
57 spin_unlock_irqrestore(&leak_lock
, flags
);
61 void btrfs_leak_debug_check(void)
63 struct extent_state
*state
;
64 struct extent_buffer
*eb
;
66 while (!list_empty(&states
)) {
67 state
= list_entry(states
.next
, struct extent_state
, leak_list
);
68 pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
69 state
->start
, state
->end
, state
->state
,
70 extent_state_in_tree(state
),
71 refcount_read(&state
->refs
));
72 list_del(&state
->leak_list
);
73 kmem_cache_free(extent_state_cache
, state
);
76 while (!list_empty(&buffers
)) {
77 eb
= list_entry(buffers
.next
, struct extent_buffer
, leak_list
);
78 pr_err("BTRFS: buffer leak start %llu len %lu refs %d\n",
79 eb
->start
, eb
->len
, atomic_read(&eb
->refs
));
80 list_del(&eb
->leak_list
);
81 kmem_cache_free(extent_buffer_cache
, eb
);
85 #define btrfs_debug_check_extent_io_range(tree, start, end) \
86 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
87 static inline void __btrfs_debug_check_extent_io_range(const char *caller
,
88 struct extent_io_tree
*tree
, u64 start
, u64 end
)
96 inode
= tree
->mapping
->host
;
97 isize
= i_size_read(inode
);
98 if (end
>= PAGE_SIZE
&& (end
% 2) == 0 && end
!= isize
- 1) {
99 btrfs_debug_rl(BTRFS_I(inode
)->root
->fs_info
,
100 "%s: ino %llu isize %llu odd range [%llu,%llu]",
101 caller
, btrfs_ino(BTRFS_I(inode
)), isize
, start
, end
);
105 #define btrfs_leak_debug_add(new, head) do {} while (0)
106 #define btrfs_leak_debug_del(entry) do {} while (0)
107 #define btrfs_leak_debug_check() do {} while (0)
108 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
111 #define BUFFER_LRU_MAX 64
116 struct rb_node rb_node
;
119 struct extent_page_data
{
121 struct extent_io_tree
*tree
;
122 get_extent_t
*get_extent
;
123 unsigned long bio_flags
;
125 /* tells writepage not to lock the state bits for this range
126 * it still does the unlocking
128 unsigned int extent_locked
:1;
130 /* tells the submit_bio code to use REQ_SYNC */
131 unsigned int sync_io
:1;
134 static void add_extent_changeset(struct extent_state
*state
, unsigned bits
,
135 struct extent_changeset
*changeset
,
142 if (set
&& (state
->state
& bits
) == bits
)
144 if (!set
&& (state
->state
& bits
) == 0)
146 changeset
->bytes_changed
+= state
->end
- state
->start
+ 1;
147 ret
= ulist_add(&changeset
->range_changed
, state
->start
, state
->end
,
153 static noinline
void flush_write_bio(void *data
);
154 static inline struct btrfs_fs_info
*
155 tree_fs_info(struct extent_io_tree
*tree
)
159 return btrfs_sb(tree
->mapping
->host
->i_sb
);
162 int __init
extent_io_init(void)
164 extent_state_cache
= kmem_cache_create("btrfs_extent_state",
165 sizeof(struct extent_state
), 0,
166 SLAB_MEM_SPREAD
, NULL
);
167 if (!extent_state_cache
)
170 extent_buffer_cache
= kmem_cache_create("btrfs_extent_buffer",
171 sizeof(struct extent_buffer
), 0,
172 SLAB_MEM_SPREAD
, NULL
);
173 if (!extent_buffer_cache
)
174 goto free_state_cache
;
176 btrfs_bioset
= bioset_create(BIO_POOL_SIZE
,
177 offsetof(struct btrfs_io_bio
, bio
));
179 goto free_buffer_cache
;
181 if (bioset_integrity_create(btrfs_bioset
, BIO_POOL_SIZE
))
187 bioset_free(btrfs_bioset
);
191 kmem_cache_destroy(extent_buffer_cache
);
192 extent_buffer_cache
= NULL
;
195 kmem_cache_destroy(extent_state_cache
);
196 extent_state_cache
= NULL
;
200 void extent_io_exit(void)
202 btrfs_leak_debug_check();
205 * Make sure all delayed rcu free are flushed before we
209 kmem_cache_destroy(extent_state_cache
);
210 kmem_cache_destroy(extent_buffer_cache
);
212 bioset_free(btrfs_bioset
);
215 void extent_io_tree_init(struct extent_io_tree
*tree
,
216 struct address_space
*mapping
)
218 tree
->state
= RB_ROOT
;
220 tree
->dirty_bytes
= 0;
221 spin_lock_init(&tree
->lock
);
222 tree
->mapping
= mapping
;
225 static struct extent_state
*alloc_extent_state(gfp_t mask
)
227 struct extent_state
*state
;
230 * The given mask might be not appropriate for the slab allocator,
231 * drop the unsupported bits
233 mask
&= ~(__GFP_DMA32
|__GFP_HIGHMEM
);
234 state
= kmem_cache_alloc(extent_state_cache
, mask
);
238 state
->failrec
= NULL
;
239 RB_CLEAR_NODE(&state
->rb_node
);
240 btrfs_leak_debug_add(&state
->leak_list
, &states
);
241 refcount_set(&state
->refs
, 1);
242 init_waitqueue_head(&state
->wq
);
243 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
247 void free_extent_state(struct extent_state
*state
)
251 if (refcount_dec_and_test(&state
->refs
)) {
252 WARN_ON(extent_state_in_tree(state
));
253 btrfs_leak_debug_del(&state
->leak_list
);
254 trace_free_extent_state(state
, _RET_IP_
);
255 kmem_cache_free(extent_state_cache
, state
);
259 static struct rb_node
*tree_insert(struct rb_root
*root
,
260 struct rb_node
*search_start
,
262 struct rb_node
*node
,
263 struct rb_node
***p_in
,
264 struct rb_node
**parent_in
)
267 struct rb_node
*parent
= NULL
;
268 struct tree_entry
*entry
;
270 if (p_in
&& parent_in
) {
276 p
= search_start
? &search_start
: &root
->rb_node
;
279 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
281 if (offset
< entry
->start
)
283 else if (offset
> entry
->end
)
290 rb_link_node(node
, parent
, p
);
291 rb_insert_color(node
, root
);
295 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
296 struct rb_node
**prev_ret
,
297 struct rb_node
**next_ret
,
298 struct rb_node
***p_ret
,
299 struct rb_node
**parent_ret
)
301 struct rb_root
*root
= &tree
->state
;
302 struct rb_node
**n
= &root
->rb_node
;
303 struct rb_node
*prev
= NULL
;
304 struct rb_node
*orig_prev
= NULL
;
305 struct tree_entry
*entry
;
306 struct tree_entry
*prev_entry
= NULL
;
310 entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
313 if (offset
< entry
->start
)
315 else if (offset
> entry
->end
)
328 while (prev
&& offset
> prev_entry
->end
) {
329 prev
= rb_next(prev
);
330 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
337 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
338 while (prev
&& offset
< prev_entry
->start
) {
339 prev
= rb_prev(prev
);
340 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
347 static inline struct rb_node
*
348 tree_search_for_insert(struct extent_io_tree
*tree
,
350 struct rb_node
***p_ret
,
351 struct rb_node
**parent_ret
)
353 struct rb_node
*prev
= NULL
;
356 ret
= __etree_search(tree
, offset
, &prev
, NULL
, p_ret
, parent_ret
);
362 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
365 return tree_search_for_insert(tree
, offset
, NULL
, NULL
);
368 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
369 struct extent_state
*other
)
371 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
372 tree
->ops
->merge_extent_hook(tree
->mapping
->host
, new,
377 * utility function to look for merge candidates inside a given range.
378 * Any extents with matching state are merged together into a single
379 * extent in the tree. Extents with EXTENT_IO in their state field
380 * are not merged because the end_io handlers need to be able to do
381 * operations on them without sleeping (or doing allocations/splits).
383 * This should be called with the tree lock held.
385 static void merge_state(struct extent_io_tree
*tree
,
386 struct extent_state
*state
)
388 struct extent_state
*other
;
389 struct rb_node
*other_node
;
391 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
394 other_node
= rb_prev(&state
->rb_node
);
396 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
397 if (other
->end
== state
->start
- 1 &&
398 other
->state
== state
->state
) {
399 merge_cb(tree
, state
, other
);
400 state
->start
= other
->start
;
401 rb_erase(&other
->rb_node
, &tree
->state
);
402 RB_CLEAR_NODE(&other
->rb_node
);
403 free_extent_state(other
);
406 other_node
= rb_next(&state
->rb_node
);
408 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
409 if (other
->start
== state
->end
+ 1 &&
410 other
->state
== state
->state
) {
411 merge_cb(tree
, state
, other
);
412 state
->end
= other
->end
;
413 rb_erase(&other
->rb_node
, &tree
->state
);
414 RB_CLEAR_NODE(&other
->rb_node
);
415 free_extent_state(other
);
420 static void set_state_cb(struct extent_io_tree
*tree
,
421 struct extent_state
*state
, unsigned *bits
)
423 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
424 tree
->ops
->set_bit_hook(tree
->mapping
->host
, state
, bits
);
427 static void clear_state_cb(struct extent_io_tree
*tree
,
428 struct extent_state
*state
, unsigned *bits
)
430 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
431 tree
->ops
->clear_bit_hook(BTRFS_I(tree
->mapping
->host
),
435 static void set_state_bits(struct extent_io_tree
*tree
,
436 struct extent_state
*state
, unsigned *bits
,
437 struct extent_changeset
*changeset
);
440 * insert an extent_state struct into the tree. 'bits' are set on the
441 * struct before it is inserted.
443 * This may return -EEXIST if the extent is already there, in which case the
444 * state struct is freed.
446 * The tree lock is not taken internally. This is a utility function and
447 * probably isn't what you want to call (see set/clear_extent_bit).
449 static int insert_state(struct extent_io_tree
*tree
,
450 struct extent_state
*state
, u64 start
, u64 end
,
452 struct rb_node
**parent
,
453 unsigned *bits
, struct extent_changeset
*changeset
)
455 struct rb_node
*node
;
458 WARN(1, KERN_ERR
"BTRFS: end < start %llu %llu\n",
460 state
->start
= start
;
463 set_state_bits(tree
, state
, bits
, changeset
);
465 node
= tree_insert(&tree
->state
, NULL
, end
, &state
->rb_node
, p
, parent
);
467 struct extent_state
*found
;
468 found
= rb_entry(node
, struct extent_state
, rb_node
);
469 pr_err("BTRFS: found node %llu %llu on insert of %llu %llu\n",
470 found
->start
, found
->end
, start
, end
);
473 merge_state(tree
, state
);
477 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
480 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
481 tree
->ops
->split_extent_hook(tree
->mapping
->host
, orig
, split
);
485 * split a given extent state struct in two, inserting the preallocated
486 * struct 'prealloc' as the newly created second half. 'split' indicates an
487 * offset inside 'orig' where it should be split.
490 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
491 * are two extent state structs in the tree:
492 * prealloc: [orig->start, split - 1]
493 * orig: [ split, orig->end ]
495 * The tree locks are not taken by this function. They need to be held
498 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
499 struct extent_state
*prealloc
, u64 split
)
501 struct rb_node
*node
;
503 split_cb(tree
, orig
, split
);
505 prealloc
->start
= orig
->start
;
506 prealloc
->end
= split
- 1;
507 prealloc
->state
= orig
->state
;
510 node
= tree_insert(&tree
->state
, &orig
->rb_node
, prealloc
->end
,
511 &prealloc
->rb_node
, NULL
, NULL
);
513 free_extent_state(prealloc
);
519 static struct extent_state
*next_state(struct extent_state
*state
)
521 struct rb_node
*next
= rb_next(&state
->rb_node
);
523 return rb_entry(next
, struct extent_state
, rb_node
);
529 * utility function to clear some bits in an extent state struct.
530 * it will optionally wake up any one waiting on this state (wake == 1).
532 * If no bits are set on the state struct after clearing things, the
533 * struct is freed and removed from the tree
535 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
536 struct extent_state
*state
,
537 unsigned *bits
, int wake
,
538 struct extent_changeset
*changeset
)
540 struct extent_state
*next
;
541 unsigned bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
543 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
544 u64 range
= state
->end
- state
->start
+ 1;
545 WARN_ON(range
> tree
->dirty_bytes
);
546 tree
->dirty_bytes
-= range
;
548 clear_state_cb(tree
, state
, bits
);
549 add_extent_changeset(state
, bits_to_clear
, changeset
, 0);
550 state
->state
&= ~bits_to_clear
;
553 if (state
->state
== 0) {
554 next
= next_state(state
);
555 if (extent_state_in_tree(state
)) {
556 rb_erase(&state
->rb_node
, &tree
->state
);
557 RB_CLEAR_NODE(&state
->rb_node
);
558 free_extent_state(state
);
563 merge_state(tree
, state
);
564 next
= next_state(state
);
569 static struct extent_state
*
570 alloc_extent_state_atomic(struct extent_state
*prealloc
)
573 prealloc
= alloc_extent_state(GFP_ATOMIC
);
578 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
580 btrfs_panic(tree_fs_info(tree
), err
,
581 "Locking error: Extent tree was modified by another thread while locked.");
585 * clear some bits on a range in the tree. This may require splitting
586 * or inserting elements in the tree, so the gfp mask is used to
587 * indicate which allocations or sleeping are allowed.
589 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
590 * the given range from the tree regardless of state (ie for truncate).
592 * the range [start, end] is inclusive.
594 * This takes the tree lock, and returns 0 on success and < 0 on error.
596 static int __clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
597 unsigned bits
, int wake
, int delete,
598 struct extent_state
**cached_state
,
599 gfp_t mask
, struct extent_changeset
*changeset
)
601 struct extent_state
*state
;
602 struct extent_state
*cached
;
603 struct extent_state
*prealloc
= NULL
;
604 struct rb_node
*node
;
609 btrfs_debug_check_extent_io_range(tree
, start
, end
);
611 if (bits
& EXTENT_DELALLOC
)
612 bits
|= EXTENT_NORESERVE
;
615 bits
|= ~EXTENT_CTLBITS
;
616 bits
|= EXTENT_FIRST_DELALLOC
;
618 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
621 if (!prealloc
&& gfpflags_allow_blocking(mask
)) {
623 * Don't care for allocation failure here because we might end
624 * up not needing the pre-allocated extent state at all, which
625 * is the case if we only have in the tree extent states that
626 * cover our input range and don't cover too any other range.
627 * If we end up needing a new extent state we allocate it later.
629 prealloc
= alloc_extent_state(mask
);
632 spin_lock(&tree
->lock
);
634 cached
= *cached_state
;
637 *cached_state
= NULL
;
641 if (cached
&& extent_state_in_tree(cached
) &&
642 cached
->start
<= start
&& cached
->end
> start
) {
644 refcount_dec(&cached
->refs
);
649 free_extent_state(cached
);
652 * this search will find the extents that end after
655 node
= tree_search(tree
, start
);
658 state
= rb_entry(node
, struct extent_state
, rb_node
);
660 if (state
->start
> end
)
662 WARN_ON(state
->end
< start
);
663 last_end
= state
->end
;
665 /* the state doesn't have the wanted bits, go ahead */
666 if (!(state
->state
& bits
)) {
667 state
= next_state(state
);
672 * | ---- desired range ---- |
674 * | ------------- state -------------- |
676 * We need to split the extent we found, and may flip
677 * bits on second half.
679 * If the extent we found extends past our range, we
680 * just split and search again. It'll get split again
681 * the next time though.
683 * If the extent we found is inside our range, we clear
684 * the desired bit on it.
687 if (state
->start
< start
) {
688 prealloc
= alloc_extent_state_atomic(prealloc
);
690 err
= split_state(tree
, state
, prealloc
, start
);
692 extent_io_tree_panic(tree
, err
);
697 if (state
->end
<= end
) {
698 state
= clear_state_bit(tree
, state
, &bits
, wake
,
705 * | ---- desired range ---- |
707 * We need to split the extent, and clear the bit
710 if (state
->start
<= end
&& state
->end
> end
) {
711 prealloc
= alloc_extent_state_atomic(prealloc
);
713 err
= split_state(tree
, state
, prealloc
, end
+ 1);
715 extent_io_tree_panic(tree
, err
);
720 clear_state_bit(tree
, prealloc
, &bits
, wake
, changeset
);
726 state
= clear_state_bit(tree
, state
, &bits
, wake
, changeset
);
728 if (last_end
== (u64
)-1)
730 start
= last_end
+ 1;
731 if (start
<= end
&& state
&& !need_resched())
737 spin_unlock(&tree
->lock
);
738 if (gfpflags_allow_blocking(mask
))
743 spin_unlock(&tree
->lock
);
745 free_extent_state(prealloc
);
751 static void wait_on_state(struct extent_io_tree
*tree
,
752 struct extent_state
*state
)
753 __releases(tree
->lock
)
754 __acquires(tree
->lock
)
757 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
758 spin_unlock(&tree
->lock
);
760 spin_lock(&tree
->lock
);
761 finish_wait(&state
->wq
, &wait
);
765 * waits for one or more bits to clear on a range in the state tree.
766 * The range [start, end] is inclusive.
767 * The tree lock is taken by this function
769 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
772 struct extent_state
*state
;
773 struct rb_node
*node
;
775 btrfs_debug_check_extent_io_range(tree
, start
, end
);
777 spin_lock(&tree
->lock
);
781 * this search will find all the extents that end after
784 node
= tree_search(tree
, start
);
789 state
= rb_entry(node
, struct extent_state
, rb_node
);
791 if (state
->start
> end
)
794 if (state
->state
& bits
) {
795 start
= state
->start
;
796 refcount_inc(&state
->refs
);
797 wait_on_state(tree
, state
);
798 free_extent_state(state
);
801 start
= state
->end
+ 1;
806 if (!cond_resched_lock(&tree
->lock
)) {
807 node
= rb_next(node
);
812 spin_unlock(&tree
->lock
);
815 static void set_state_bits(struct extent_io_tree
*tree
,
816 struct extent_state
*state
,
817 unsigned *bits
, struct extent_changeset
*changeset
)
819 unsigned bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
821 set_state_cb(tree
, state
, bits
);
822 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
823 u64 range
= state
->end
- state
->start
+ 1;
824 tree
->dirty_bytes
+= range
;
826 add_extent_changeset(state
, bits_to_set
, changeset
, 1);
827 state
->state
|= bits_to_set
;
830 static void cache_state_if_flags(struct extent_state
*state
,
831 struct extent_state
**cached_ptr
,
834 if (cached_ptr
&& !(*cached_ptr
)) {
835 if (!flags
|| (state
->state
& flags
)) {
837 refcount_inc(&state
->refs
);
842 static void cache_state(struct extent_state
*state
,
843 struct extent_state
**cached_ptr
)
845 return cache_state_if_flags(state
, cached_ptr
,
846 EXTENT_IOBITS
| EXTENT_BOUNDARY
);
850 * set some bits on a range in the tree. This may require allocations or
851 * sleeping, so the gfp mask is used to indicate what is allowed.
853 * If any of the exclusive bits are set, this will fail with -EEXIST if some
854 * part of the range already has the desired bits set. The start of the
855 * existing range is returned in failed_start in this case.
857 * [start, end] is inclusive This takes the tree lock.
860 static int __must_check
861 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
862 unsigned bits
, unsigned exclusive_bits
,
863 u64
*failed_start
, struct extent_state
**cached_state
,
864 gfp_t mask
, struct extent_changeset
*changeset
)
866 struct extent_state
*state
;
867 struct extent_state
*prealloc
= NULL
;
868 struct rb_node
*node
;
870 struct rb_node
*parent
;
875 btrfs_debug_check_extent_io_range(tree
, start
, end
);
877 bits
|= EXTENT_FIRST_DELALLOC
;
879 if (!prealloc
&& gfpflags_allow_blocking(mask
)) {
881 * Don't care for allocation failure here because we might end
882 * up not needing the pre-allocated extent state at all, which
883 * is the case if we only have in the tree extent states that
884 * cover our input range and don't cover too any other range.
885 * If we end up needing a new extent state we allocate it later.
887 prealloc
= alloc_extent_state(mask
);
890 spin_lock(&tree
->lock
);
891 if (cached_state
&& *cached_state
) {
892 state
= *cached_state
;
893 if (state
->start
<= start
&& state
->end
> start
&&
894 extent_state_in_tree(state
)) {
895 node
= &state
->rb_node
;
900 * this search will find all the extents that end after
903 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
905 prealloc
= alloc_extent_state_atomic(prealloc
);
907 err
= insert_state(tree
, prealloc
, start
, end
,
908 &p
, &parent
, &bits
, changeset
);
910 extent_io_tree_panic(tree
, err
);
912 cache_state(prealloc
, cached_state
);
916 state
= rb_entry(node
, struct extent_state
, rb_node
);
918 last_start
= state
->start
;
919 last_end
= state
->end
;
922 * | ---- desired range ---- |
925 * Just lock what we found and keep going
927 if (state
->start
== start
&& state
->end
<= end
) {
928 if (state
->state
& exclusive_bits
) {
929 *failed_start
= state
->start
;
934 set_state_bits(tree
, state
, &bits
, changeset
);
935 cache_state(state
, cached_state
);
936 merge_state(tree
, state
);
937 if (last_end
== (u64
)-1)
939 start
= last_end
+ 1;
940 state
= next_state(state
);
941 if (start
< end
&& state
&& state
->start
== start
&&
948 * | ---- desired range ---- |
951 * | ------------- state -------------- |
953 * We need to split the extent we found, and may flip bits on
956 * If the extent we found extends past our
957 * range, we just split and search again. It'll get split
958 * again the next time though.
960 * If the extent we found is inside our range, we set the
963 if (state
->start
< start
) {
964 if (state
->state
& exclusive_bits
) {
965 *failed_start
= start
;
970 prealloc
= alloc_extent_state_atomic(prealloc
);
972 err
= split_state(tree
, state
, prealloc
, start
);
974 extent_io_tree_panic(tree
, err
);
979 if (state
->end
<= end
) {
980 set_state_bits(tree
, state
, &bits
, changeset
);
981 cache_state(state
, cached_state
);
982 merge_state(tree
, state
);
983 if (last_end
== (u64
)-1)
985 start
= last_end
+ 1;
986 state
= next_state(state
);
987 if (start
< end
&& state
&& state
->start
== start
&&
994 * | ---- desired range ---- |
995 * | state | or | state |
997 * There's a hole, we need to insert something in it and
998 * ignore the extent we found.
1000 if (state
->start
> start
) {
1002 if (end
< last_start
)
1005 this_end
= last_start
- 1;
1007 prealloc
= alloc_extent_state_atomic(prealloc
);
1011 * Avoid to free 'prealloc' if it can be merged with
1014 err
= insert_state(tree
, prealloc
, start
, this_end
,
1015 NULL
, NULL
, &bits
, changeset
);
1017 extent_io_tree_panic(tree
, err
);
1019 cache_state(prealloc
, cached_state
);
1021 start
= this_end
+ 1;
1025 * | ---- desired range ---- |
1027 * We need to split the extent, and set the bit
1030 if (state
->start
<= end
&& state
->end
> end
) {
1031 if (state
->state
& exclusive_bits
) {
1032 *failed_start
= start
;
1037 prealloc
= alloc_extent_state_atomic(prealloc
);
1039 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1041 extent_io_tree_panic(tree
, err
);
1043 set_state_bits(tree
, prealloc
, &bits
, changeset
);
1044 cache_state(prealloc
, cached_state
);
1045 merge_state(tree
, prealloc
);
1053 spin_unlock(&tree
->lock
);
1054 if (gfpflags_allow_blocking(mask
))
1059 spin_unlock(&tree
->lock
);
1061 free_extent_state(prealloc
);
1067 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1068 unsigned bits
, u64
* failed_start
,
1069 struct extent_state
**cached_state
, gfp_t mask
)
1071 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
1072 cached_state
, mask
, NULL
);
1077 * convert_extent_bit - convert all bits in a given range from one bit to
1079 * @tree: the io tree to search
1080 * @start: the start offset in bytes
1081 * @end: the end offset in bytes (inclusive)
1082 * @bits: the bits to set in this range
1083 * @clear_bits: the bits to clear in this range
1084 * @cached_state: state that we're going to cache
1086 * This will go through and set bits for the given range. If any states exist
1087 * already in this range they are set with the given bit and cleared of the
1088 * clear_bits. This is only meant to be used by things that are mergeable, ie
1089 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1090 * boundary bits like LOCK.
1092 * All allocations are done with GFP_NOFS.
1094 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1095 unsigned bits
, unsigned clear_bits
,
1096 struct extent_state
**cached_state
)
1098 struct extent_state
*state
;
1099 struct extent_state
*prealloc
= NULL
;
1100 struct rb_node
*node
;
1102 struct rb_node
*parent
;
1106 bool first_iteration
= true;
1108 btrfs_debug_check_extent_io_range(tree
, start
, end
);
1113 * Best effort, don't worry if extent state allocation fails
1114 * here for the first iteration. We might have a cached state
1115 * that matches exactly the target range, in which case no
1116 * extent state allocations are needed. We'll only know this
1117 * after locking the tree.
1119 prealloc
= alloc_extent_state(GFP_NOFS
);
1120 if (!prealloc
&& !first_iteration
)
1124 spin_lock(&tree
->lock
);
1125 if (cached_state
&& *cached_state
) {
1126 state
= *cached_state
;
1127 if (state
->start
<= start
&& state
->end
> start
&&
1128 extent_state_in_tree(state
)) {
1129 node
= &state
->rb_node
;
1135 * this search will find all the extents that end after
1138 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
1140 prealloc
= alloc_extent_state_atomic(prealloc
);
1145 err
= insert_state(tree
, prealloc
, start
, end
,
1146 &p
, &parent
, &bits
, NULL
);
1148 extent_io_tree_panic(tree
, err
);
1149 cache_state(prealloc
, cached_state
);
1153 state
= rb_entry(node
, struct extent_state
, rb_node
);
1155 last_start
= state
->start
;
1156 last_end
= state
->end
;
1159 * | ---- desired range ---- |
1162 * Just lock what we found and keep going
1164 if (state
->start
== start
&& state
->end
<= end
) {
1165 set_state_bits(tree
, state
, &bits
, NULL
);
1166 cache_state(state
, cached_state
);
1167 state
= clear_state_bit(tree
, state
, &clear_bits
, 0, NULL
);
1168 if (last_end
== (u64
)-1)
1170 start
= last_end
+ 1;
1171 if (start
< end
&& state
&& state
->start
== start
&&
1178 * | ---- desired range ---- |
1181 * | ------------- state -------------- |
1183 * We need to split the extent we found, and may flip bits on
1186 * If the extent we found extends past our
1187 * range, we just split and search again. It'll get split
1188 * again the next time though.
1190 * If the extent we found is inside our range, we set the
1191 * desired bit on it.
1193 if (state
->start
< start
) {
1194 prealloc
= alloc_extent_state_atomic(prealloc
);
1199 err
= split_state(tree
, state
, prealloc
, start
);
1201 extent_io_tree_panic(tree
, err
);
1205 if (state
->end
<= end
) {
1206 set_state_bits(tree
, state
, &bits
, NULL
);
1207 cache_state(state
, cached_state
);
1208 state
= clear_state_bit(tree
, state
, &clear_bits
, 0,
1210 if (last_end
== (u64
)-1)
1212 start
= last_end
+ 1;
1213 if (start
< end
&& state
&& state
->start
== start
&&
1220 * | ---- desired range ---- |
1221 * | state | or | state |
1223 * There's a hole, we need to insert something in it and
1224 * ignore the extent we found.
1226 if (state
->start
> start
) {
1228 if (end
< last_start
)
1231 this_end
= last_start
- 1;
1233 prealloc
= alloc_extent_state_atomic(prealloc
);
1240 * Avoid to free 'prealloc' if it can be merged with
1243 err
= insert_state(tree
, prealloc
, start
, this_end
,
1244 NULL
, NULL
, &bits
, NULL
);
1246 extent_io_tree_panic(tree
, err
);
1247 cache_state(prealloc
, cached_state
);
1249 start
= this_end
+ 1;
1253 * | ---- desired range ---- |
1255 * We need to split the extent, and set the bit
1258 if (state
->start
<= end
&& state
->end
> end
) {
1259 prealloc
= alloc_extent_state_atomic(prealloc
);
1265 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1267 extent_io_tree_panic(tree
, err
);
1269 set_state_bits(tree
, prealloc
, &bits
, NULL
);
1270 cache_state(prealloc
, cached_state
);
1271 clear_state_bit(tree
, prealloc
, &clear_bits
, 0, NULL
);
1279 spin_unlock(&tree
->lock
);
1281 first_iteration
= false;
1285 spin_unlock(&tree
->lock
);
1287 free_extent_state(prealloc
);
1292 /* wrappers around set/clear extent bit */
1293 int set_record_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1294 unsigned bits
, struct extent_changeset
*changeset
)
1297 * We don't support EXTENT_LOCKED yet, as current changeset will
1298 * record any bits changed, so for EXTENT_LOCKED case, it will
1299 * either fail with -EEXIST or changeset will record the whole
1302 BUG_ON(bits
& EXTENT_LOCKED
);
1304 return __set_extent_bit(tree
, start
, end
, bits
, 0, NULL
, NULL
, GFP_NOFS
,
1308 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1309 unsigned bits
, int wake
, int delete,
1310 struct extent_state
**cached
, gfp_t mask
)
1312 return __clear_extent_bit(tree
, start
, end
, bits
, wake
, delete,
1313 cached
, mask
, NULL
);
1316 int clear_record_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1317 unsigned bits
, struct extent_changeset
*changeset
)
1320 * Don't support EXTENT_LOCKED case, same reason as
1321 * set_record_extent_bits().
1323 BUG_ON(bits
& EXTENT_LOCKED
);
1325 return __clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, GFP_NOFS
,
1330 * either insert or lock state struct between start and end use mask to tell
1331 * us if waiting is desired.
1333 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1334 struct extent_state
**cached_state
)
1340 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
,
1341 EXTENT_LOCKED
, &failed_start
,
1342 cached_state
, GFP_NOFS
, NULL
);
1343 if (err
== -EEXIST
) {
1344 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1345 start
= failed_start
;
1348 WARN_ON(start
> end
);
1353 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1358 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1359 &failed_start
, NULL
, GFP_NOFS
, NULL
);
1360 if (err
== -EEXIST
) {
1361 if (failed_start
> start
)
1362 clear_extent_bit(tree
, start
, failed_start
- 1,
1363 EXTENT_LOCKED
, 1, 0, NULL
, GFP_NOFS
);
1369 void extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1371 unsigned long index
= start
>> PAGE_SHIFT
;
1372 unsigned long end_index
= end
>> PAGE_SHIFT
;
1375 while (index
<= end_index
) {
1376 page
= find_get_page(inode
->i_mapping
, index
);
1377 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1378 clear_page_dirty_for_io(page
);
1384 void extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1386 unsigned long index
= start
>> PAGE_SHIFT
;
1387 unsigned long end_index
= end
>> PAGE_SHIFT
;
1390 while (index
<= end_index
) {
1391 page
= find_get_page(inode
->i_mapping
, index
);
1392 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1393 __set_page_dirty_nobuffers(page
);
1394 account_page_redirty(page
);
1401 * helper function to set both pages and extents in the tree writeback
1403 static void set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1405 unsigned long index
= start
>> PAGE_SHIFT
;
1406 unsigned long end_index
= end
>> PAGE_SHIFT
;
1409 while (index
<= end_index
) {
1410 page
= find_get_page(tree
->mapping
, index
);
1411 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1412 set_page_writeback(page
);
1418 /* find the first state struct with 'bits' set after 'start', and
1419 * return it. tree->lock must be held. NULL will returned if
1420 * nothing was found after 'start'
1422 static struct extent_state
*
1423 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1424 u64 start
, unsigned bits
)
1426 struct rb_node
*node
;
1427 struct extent_state
*state
;
1430 * this search will find all the extents that end after
1433 node
= tree_search(tree
, start
);
1438 state
= rb_entry(node
, struct extent_state
, rb_node
);
1439 if (state
->end
>= start
&& (state
->state
& bits
))
1442 node
= rb_next(node
);
1451 * find the first offset in the io tree with 'bits' set. zero is
1452 * returned if we find something, and *start_ret and *end_ret are
1453 * set to reflect the state struct that was found.
1455 * If nothing was found, 1 is returned. If found something, return 0.
1457 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1458 u64
*start_ret
, u64
*end_ret
, unsigned bits
,
1459 struct extent_state
**cached_state
)
1461 struct extent_state
*state
;
1465 spin_lock(&tree
->lock
);
1466 if (cached_state
&& *cached_state
) {
1467 state
= *cached_state
;
1468 if (state
->end
== start
- 1 && extent_state_in_tree(state
)) {
1469 n
= rb_next(&state
->rb_node
);
1471 state
= rb_entry(n
, struct extent_state
,
1473 if (state
->state
& bits
)
1477 free_extent_state(*cached_state
);
1478 *cached_state
= NULL
;
1481 free_extent_state(*cached_state
);
1482 *cached_state
= NULL
;
1485 state
= find_first_extent_bit_state(tree
, start
, bits
);
1488 cache_state_if_flags(state
, cached_state
, 0);
1489 *start_ret
= state
->start
;
1490 *end_ret
= state
->end
;
1494 spin_unlock(&tree
->lock
);
1499 * find a contiguous range of bytes in the file marked as delalloc, not
1500 * more than 'max_bytes'. start and end are used to return the range,
1502 * 1 is returned if we find something, 0 if nothing was in the tree
1504 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1505 u64
*start
, u64
*end
, u64 max_bytes
,
1506 struct extent_state
**cached_state
)
1508 struct rb_node
*node
;
1509 struct extent_state
*state
;
1510 u64 cur_start
= *start
;
1512 u64 total_bytes
= 0;
1514 spin_lock(&tree
->lock
);
1517 * this search will find all the extents that end after
1520 node
= tree_search(tree
, cur_start
);
1528 state
= rb_entry(node
, struct extent_state
, rb_node
);
1529 if (found
&& (state
->start
!= cur_start
||
1530 (state
->state
& EXTENT_BOUNDARY
))) {
1533 if (!(state
->state
& EXTENT_DELALLOC
)) {
1539 *start
= state
->start
;
1540 *cached_state
= state
;
1541 refcount_inc(&state
->refs
);
1545 cur_start
= state
->end
+ 1;
1546 node
= rb_next(node
);
1547 total_bytes
+= state
->end
- state
->start
+ 1;
1548 if (total_bytes
>= max_bytes
)
1554 spin_unlock(&tree
->lock
);
1558 static int __process_pages_contig(struct address_space
*mapping
,
1559 struct page
*locked_page
,
1560 pgoff_t start_index
, pgoff_t end_index
,
1561 unsigned long page_ops
, pgoff_t
*index_ret
);
1563 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1564 struct page
*locked_page
,
1567 unsigned long index
= start
>> PAGE_SHIFT
;
1568 unsigned long end_index
= end
>> PAGE_SHIFT
;
1570 ASSERT(locked_page
);
1571 if (index
== locked_page
->index
&& end_index
== index
)
1574 __process_pages_contig(inode
->i_mapping
, locked_page
, index
, end_index
,
1578 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1579 struct page
*locked_page
,
1583 unsigned long index
= delalloc_start
>> PAGE_SHIFT
;
1584 unsigned long index_ret
= index
;
1585 unsigned long end_index
= delalloc_end
>> PAGE_SHIFT
;
1588 ASSERT(locked_page
);
1589 if (index
== locked_page
->index
&& index
== end_index
)
1592 ret
= __process_pages_contig(inode
->i_mapping
, locked_page
, index
,
1593 end_index
, PAGE_LOCK
, &index_ret
);
1595 __unlock_for_delalloc(inode
, locked_page
, delalloc_start
,
1596 (u64
)index_ret
<< PAGE_SHIFT
);
1601 * find a contiguous range of bytes in the file marked as delalloc, not
1602 * more than 'max_bytes'. start and end are used to return the range,
1604 * 1 is returned if we find something, 0 if nothing was in the tree
1606 STATIC u64
find_lock_delalloc_range(struct inode
*inode
,
1607 struct extent_io_tree
*tree
,
1608 struct page
*locked_page
, u64
*start
,
1609 u64
*end
, u64 max_bytes
)
1614 struct extent_state
*cached_state
= NULL
;
1619 /* step one, find a bunch of delalloc bytes starting at start */
1620 delalloc_start
= *start
;
1622 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1623 max_bytes
, &cached_state
);
1624 if (!found
|| delalloc_end
<= *start
) {
1625 *start
= delalloc_start
;
1626 *end
= delalloc_end
;
1627 free_extent_state(cached_state
);
1632 * start comes from the offset of locked_page. We have to lock
1633 * pages in order, so we can't process delalloc bytes before
1636 if (delalloc_start
< *start
)
1637 delalloc_start
= *start
;
1640 * make sure to limit the number of pages we try to lock down
1642 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
)
1643 delalloc_end
= delalloc_start
+ max_bytes
- 1;
1645 /* step two, lock all the pages after the page that has start */
1646 ret
= lock_delalloc_pages(inode
, locked_page
,
1647 delalloc_start
, delalloc_end
);
1648 if (ret
== -EAGAIN
) {
1649 /* some of the pages are gone, lets avoid looping by
1650 * shortening the size of the delalloc range we're searching
1652 free_extent_state(cached_state
);
1653 cached_state
= NULL
;
1655 max_bytes
= PAGE_SIZE
;
1663 BUG_ON(ret
); /* Only valid values are 0 and -EAGAIN */
1665 /* step three, lock the state bits for the whole range */
1666 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, &cached_state
);
1668 /* then test to make sure it is all still delalloc */
1669 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1670 EXTENT_DELALLOC
, 1, cached_state
);
1672 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1673 &cached_state
, GFP_NOFS
);
1674 __unlock_for_delalloc(inode
, locked_page
,
1675 delalloc_start
, delalloc_end
);
1679 free_extent_state(cached_state
);
1680 *start
= delalloc_start
;
1681 *end
= delalloc_end
;
1686 static int __process_pages_contig(struct address_space
*mapping
,
1687 struct page
*locked_page
,
1688 pgoff_t start_index
, pgoff_t end_index
,
1689 unsigned long page_ops
, pgoff_t
*index_ret
)
1691 unsigned long nr_pages
= end_index
- start_index
+ 1;
1692 unsigned long pages_locked
= 0;
1693 pgoff_t index
= start_index
;
1694 struct page
*pages
[16];
1699 if (page_ops
& PAGE_LOCK
) {
1700 ASSERT(page_ops
== PAGE_LOCK
);
1701 ASSERT(index_ret
&& *index_ret
== start_index
);
1704 if ((page_ops
& PAGE_SET_ERROR
) && nr_pages
> 0)
1705 mapping_set_error(mapping
, -EIO
);
1707 while (nr_pages
> 0) {
1708 ret
= find_get_pages_contig(mapping
, index
,
1709 min_t(unsigned long,
1710 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1713 * Only if we're going to lock these pages,
1714 * can we find nothing at @index.
1716 ASSERT(page_ops
& PAGE_LOCK
);
1721 for (i
= 0; i
< ret
; i
++) {
1722 if (page_ops
& PAGE_SET_PRIVATE2
)
1723 SetPagePrivate2(pages
[i
]);
1725 if (pages
[i
] == locked_page
) {
1730 if (page_ops
& PAGE_CLEAR_DIRTY
)
1731 clear_page_dirty_for_io(pages
[i
]);
1732 if (page_ops
& PAGE_SET_WRITEBACK
)
1733 set_page_writeback(pages
[i
]);
1734 if (page_ops
& PAGE_SET_ERROR
)
1735 SetPageError(pages
[i
]);
1736 if (page_ops
& PAGE_END_WRITEBACK
)
1737 end_page_writeback(pages
[i
]);
1738 if (page_ops
& PAGE_UNLOCK
)
1739 unlock_page(pages
[i
]);
1740 if (page_ops
& PAGE_LOCK
) {
1741 lock_page(pages
[i
]);
1742 if (!PageDirty(pages
[i
]) ||
1743 pages
[i
]->mapping
!= mapping
) {
1744 unlock_page(pages
[i
]);
1758 if (err
&& index_ret
)
1759 *index_ret
= start_index
+ pages_locked
- 1;
1763 void extent_clear_unlock_delalloc(struct inode
*inode
, u64 start
, u64 end
,
1764 u64 delalloc_end
, struct page
*locked_page
,
1765 unsigned clear_bits
,
1766 unsigned long page_ops
)
1768 clear_extent_bit(&BTRFS_I(inode
)->io_tree
, start
, end
, clear_bits
, 1, 0,
1771 __process_pages_contig(inode
->i_mapping
, locked_page
,
1772 start
>> PAGE_SHIFT
, end
>> PAGE_SHIFT
,
1777 * count the number of bytes in the tree that have a given bit(s)
1778 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1779 * cached. The total number found is returned.
1781 u64
count_range_bits(struct extent_io_tree
*tree
,
1782 u64
*start
, u64 search_end
, u64 max_bytes
,
1783 unsigned bits
, int contig
)
1785 struct rb_node
*node
;
1786 struct extent_state
*state
;
1787 u64 cur_start
= *start
;
1788 u64 total_bytes
= 0;
1792 if (WARN_ON(search_end
<= cur_start
))
1795 spin_lock(&tree
->lock
);
1796 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1797 total_bytes
= tree
->dirty_bytes
;
1801 * this search will find all the extents that end after
1804 node
= tree_search(tree
, cur_start
);
1809 state
= rb_entry(node
, struct extent_state
, rb_node
);
1810 if (state
->start
> search_end
)
1812 if (contig
&& found
&& state
->start
> last
+ 1)
1814 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1815 total_bytes
+= min(search_end
, state
->end
) + 1 -
1816 max(cur_start
, state
->start
);
1817 if (total_bytes
>= max_bytes
)
1820 *start
= max(cur_start
, state
->start
);
1824 } else if (contig
&& found
) {
1827 node
= rb_next(node
);
1832 spin_unlock(&tree
->lock
);
1837 * set the private field for a given byte offset in the tree. If there isn't
1838 * an extent_state there already, this does nothing.
1840 static noinline
int set_state_failrec(struct extent_io_tree
*tree
, u64 start
,
1841 struct io_failure_record
*failrec
)
1843 struct rb_node
*node
;
1844 struct extent_state
*state
;
1847 spin_lock(&tree
->lock
);
1849 * this search will find all the extents that end after
1852 node
= tree_search(tree
, start
);
1857 state
= rb_entry(node
, struct extent_state
, rb_node
);
1858 if (state
->start
!= start
) {
1862 state
->failrec
= failrec
;
1864 spin_unlock(&tree
->lock
);
1868 static noinline
int get_state_failrec(struct extent_io_tree
*tree
, u64 start
,
1869 struct io_failure_record
**failrec
)
1871 struct rb_node
*node
;
1872 struct extent_state
*state
;
1875 spin_lock(&tree
->lock
);
1877 * this search will find all the extents that end after
1880 node
= tree_search(tree
, start
);
1885 state
= rb_entry(node
, struct extent_state
, rb_node
);
1886 if (state
->start
!= start
) {
1890 *failrec
= state
->failrec
;
1892 spin_unlock(&tree
->lock
);
1897 * searches a range in the state tree for a given mask.
1898 * If 'filled' == 1, this returns 1 only if every extent in the tree
1899 * has the bits set. Otherwise, 1 is returned if any bit in the
1900 * range is found set.
1902 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1903 unsigned bits
, int filled
, struct extent_state
*cached
)
1905 struct extent_state
*state
= NULL
;
1906 struct rb_node
*node
;
1909 spin_lock(&tree
->lock
);
1910 if (cached
&& extent_state_in_tree(cached
) && cached
->start
<= start
&&
1911 cached
->end
> start
)
1912 node
= &cached
->rb_node
;
1914 node
= tree_search(tree
, start
);
1915 while (node
&& start
<= end
) {
1916 state
= rb_entry(node
, struct extent_state
, rb_node
);
1918 if (filled
&& state
->start
> start
) {
1923 if (state
->start
> end
)
1926 if (state
->state
& bits
) {
1930 } else if (filled
) {
1935 if (state
->end
== (u64
)-1)
1938 start
= state
->end
+ 1;
1941 node
= rb_next(node
);
1948 spin_unlock(&tree
->lock
);
1953 * helper function to set a given page up to date if all the
1954 * extents in the tree for that page are up to date
1956 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
1958 u64 start
= page_offset(page
);
1959 u64 end
= start
+ PAGE_SIZE
- 1;
1960 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1961 SetPageUptodate(page
);
1964 int free_io_failure(struct btrfs_inode
*inode
, struct io_failure_record
*rec
)
1968 struct extent_io_tree
*failure_tree
= &inode
->io_failure_tree
;
1970 set_state_failrec(failure_tree
, rec
->start
, NULL
);
1971 ret
= clear_extent_bits(failure_tree
, rec
->start
,
1972 rec
->start
+ rec
->len
- 1,
1973 EXTENT_LOCKED
| EXTENT_DIRTY
);
1977 ret
= clear_extent_bits(&inode
->io_tree
, rec
->start
,
1978 rec
->start
+ rec
->len
- 1,
1988 * this bypasses the standard btrfs submit functions deliberately, as
1989 * the standard behavior is to write all copies in a raid setup. here we only
1990 * want to write the one bad copy. so we do the mapping for ourselves and issue
1991 * submit_bio directly.
1992 * to avoid any synchronization issues, wait for the data after writing, which
1993 * actually prevents the read that triggered the error from finishing.
1994 * currently, there can be no more than two copies of every data bit. thus,
1995 * exactly one rewrite is required.
1997 int repair_io_failure(struct btrfs_inode
*inode
, u64 start
, u64 length
,
1998 u64 logical
, struct page
*page
,
1999 unsigned int pg_offset
, int mirror_num
)
2001 struct btrfs_fs_info
*fs_info
= inode
->root
->fs_info
;
2003 struct btrfs_device
*dev
;
2006 struct btrfs_bio
*bbio
= NULL
;
2009 ASSERT(!(fs_info
->sb
->s_flags
& MS_RDONLY
));
2010 BUG_ON(!mirror_num
);
2012 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2015 bio
->bi_iter
.bi_size
= 0;
2016 map_length
= length
;
2019 * Avoid races with device replace and make sure our bbio has devices
2020 * associated to its stripes that don't go away while we are doing the
2021 * read repair operation.
2023 btrfs_bio_counter_inc_blocked(fs_info
);
2024 if (btrfs_is_parity_mirror(fs_info
, logical
, length
, mirror_num
)) {
2026 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
2027 * to update all raid stripes, but here we just want to correct
2028 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
2029 * stripe's dev and sector.
2031 ret
= btrfs_map_block(fs_info
, BTRFS_MAP_READ
, logical
,
2032 &map_length
, &bbio
, 0);
2034 btrfs_bio_counter_dec(fs_info
);
2038 ASSERT(bbio
->mirror_num
== 1);
2040 ret
= btrfs_map_block(fs_info
, BTRFS_MAP_WRITE
, logical
,
2041 &map_length
, &bbio
, mirror_num
);
2043 btrfs_bio_counter_dec(fs_info
);
2047 BUG_ON(mirror_num
!= bbio
->mirror_num
);
2050 sector
= bbio
->stripes
[bbio
->mirror_num
- 1].physical
>> 9;
2051 bio
->bi_iter
.bi_sector
= sector
;
2052 dev
= bbio
->stripes
[bbio
->mirror_num
- 1].dev
;
2053 btrfs_put_bbio(bbio
);
2054 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2055 btrfs_bio_counter_dec(fs_info
);
2059 bio
->bi_bdev
= dev
->bdev
;
2060 bio
->bi_opf
= REQ_OP_WRITE
| REQ_SYNC
;
2061 bio_add_page(bio
, page
, length
, pg_offset
);
2063 if (btrfsic_submit_bio_wait(bio
)) {
2064 /* try to remap that extent elsewhere? */
2065 btrfs_bio_counter_dec(fs_info
);
2067 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2071 btrfs_info_rl_in_rcu(fs_info
,
2072 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2073 btrfs_ino(inode
), start
,
2074 rcu_str_deref(dev
->name
), sector
);
2075 btrfs_bio_counter_dec(fs_info
);
2080 int repair_eb_io_failure(struct btrfs_fs_info
*fs_info
,
2081 struct extent_buffer
*eb
, int mirror_num
)
2083 u64 start
= eb
->start
;
2084 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2087 if (fs_info
->sb
->s_flags
& MS_RDONLY
)
2090 for (i
= 0; i
< num_pages
; i
++) {
2091 struct page
*p
= eb
->pages
[i
];
2093 ret
= repair_io_failure(BTRFS_I(fs_info
->btree_inode
), start
,
2094 PAGE_SIZE
, start
, p
,
2095 start
- page_offset(p
), mirror_num
);
2105 * each time an IO finishes, we do a fast check in the IO failure tree
2106 * to see if we need to process or clean up an io_failure_record
2108 int clean_io_failure(struct btrfs_inode
*inode
, u64 start
, struct page
*page
,
2109 unsigned int pg_offset
)
2112 struct io_failure_record
*failrec
;
2113 struct btrfs_fs_info
*fs_info
= inode
->root
->fs_info
;
2114 struct extent_state
*state
;
2119 ret
= count_range_bits(&inode
->io_failure_tree
, &private,
2120 (u64
)-1, 1, EXTENT_DIRTY
, 0);
2124 ret
= get_state_failrec(&inode
->io_failure_tree
, start
,
2129 BUG_ON(!failrec
->this_mirror
);
2131 if (failrec
->in_validation
) {
2132 /* there was no real error, just free the record */
2133 btrfs_debug(fs_info
,
2134 "clean_io_failure: freeing dummy error at %llu",
2138 if (fs_info
->sb
->s_flags
& MS_RDONLY
)
2141 spin_lock(&inode
->io_tree
.lock
);
2142 state
= find_first_extent_bit_state(&inode
->io_tree
,
2145 spin_unlock(&inode
->io_tree
.lock
);
2147 if (state
&& state
->start
<= failrec
->start
&&
2148 state
->end
>= failrec
->start
+ failrec
->len
- 1) {
2149 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2151 if (num_copies
> 1) {
2152 repair_io_failure(inode
, start
, failrec
->len
,
2153 failrec
->logical
, page
,
2154 pg_offset
, failrec
->failed_mirror
);
2159 free_io_failure(inode
, failrec
);
2165 * Can be called when
2166 * - hold extent lock
2167 * - under ordered extent
2168 * - the inode is freeing
2170 void btrfs_free_io_failure_record(struct btrfs_inode
*inode
, u64 start
, u64 end
)
2172 struct extent_io_tree
*failure_tree
= &inode
->io_failure_tree
;
2173 struct io_failure_record
*failrec
;
2174 struct extent_state
*state
, *next
;
2176 if (RB_EMPTY_ROOT(&failure_tree
->state
))
2179 spin_lock(&failure_tree
->lock
);
2180 state
= find_first_extent_bit_state(failure_tree
, start
, EXTENT_DIRTY
);
2182 if (state
->start
> end
)
2185 ASSERT(state
->end
<= end
);
2187 next
= next_state(state
);
2189 failrec
= state
->failrec
;
2190 free_extent_state(state
);
2195 spin_unlock(&failure_tree
->lock
);
2198 int btrfs_get_io_failure_record(struct inode
*inode
, u64 start
, u64 end
,
2199 struct io_failure_record
**failrec_ret
)
2201 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2202 struct io_failure_record
*failrec
;
2203 struct extent_map
*em
;
2204 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2205 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2206 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2210 ret
= get_state_failrec(failure_tree
, start
, &failrec
);
2212 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2216 failrec
->start
= start
;
2217 failrec
->len
= end
- start
+ 1;
2218 failrec
->this_mirror
= 0;
2219 failrec
->bio_flags
= 0;
2220 failrec
->in_validation
= 0;
2222 read_lock(&em_tree
->lock
);
2223 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2225 read_unlock(&em_tree
->lock
);
2230 if (em
->start
> start
|| em
->start
+ em
->len
<= start
) {
2231 free_extent_map(em
);
2234 read_unlock(&em_tree
->lock
);
2240 logical
= start
- em
->start
;
2241 logical
= em
->block_start
+ logical
;
2242 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2243 logical
= em
->block_start
;
2244 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2245 extent_set_compress_type(&failrec
->bio_flags
,
2249 btrfs_debug(fs_info
,
2250 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2251 logical
, start
, failrec
->len
);
2253 failrec
->logical
= logical
;
2254 free_extent_map(em
);
2256 /* set the bits in the private failure tree */
2257 ret
= set_extent_bits(failure_tree
, start
, end
,
2258 EXTENT_LOCKED
| EXTENT_DIRTY
);
2260 ret
= set_state_failrec(failure_tree
, start
, failrec
);
2261 /* set the bits in the inode's tree */
2263 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
);
2269 btrfs_debug(fs_info
,
2270 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2271 failrec
->logical
, failrec
->start
, failrec
->len
,
2272 failrec
->in_validation
);
2274 * when data can be on disk more than twice, add to failrec here
2275 * (e.g. with a list for failed_mirror) to make
2276 * clean_io_failure() clean all those errors at once.
2280 *failrec_ret
= failrec
;
2285 int btrfs_check_repairable(struct inode
*inode
, struct bio
*failed_bio
,
2286 struct io_failure_record
*failrec
, int failed_mirror
)
2288 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2291 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
, failrec
->len
);
2292 if (num_copies
== 1) {
2294 * we only have a single copy of the data, so don't bother with
2295 * all the retry and error correction code that follows. no
2296 * matter what the error is, it is very likely to persist.
2298 btrfs_debug(fs_info
,
2299 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2300 num_copies
, failrec
->this_mirror
, failed_mirror
);
2305 * there are two premises:
2306 * a) deliver good data to the caller
2307 * b) correct the bad sectors on disk
2309 if (failed_bio
->bi_vcnt
> 1) {
2311 * to fulfill b), we need to know the exact failing sectors, as
2312 * we don't want to rewrite any more than the failed ones. thus,
2313 * we need separate read requests for the failed bio
2315 * if the following BUG_ON triggers, our validation request got
2316 * merged. we need separate requests for our algorithm to work.
2318 BUG_ON(failrec
->in_validation
);
2319 failrec
->in_validation
= 1;
2320 failrec
->this_mirror
= failed_mirror
;
2323 * we're ready to fulfill a) and b) alongside. get a good copy
2324 * of the failed sector and if we succeed, we have setup
2325 * everything for repair_io_failure to do the rest for us.
2327 if (failrec
->in_validation
) {
2328 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2329 failrec
->in_validation
= 0;
2330 failrec
->this_mirror
= 0;
2332 failrec
->failed_mirror
= failed_mirror
;
2333 failrec
->this_mirror
++;
2334 if (failrec
->this_mirror
== failed_mirror
)
2335 failrec
->this_mirror
++;
2338 if (failrec
->this_mirror
> num_copies
) {
2339 btrfs_debug(fs_info
,
2340 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2341 num_copies
, failrec
->this_mirror
, failed_mirror
);
2349 struct bio
*btrfs_create_repair_bio(struct inode
*inode
, struct bio
*failed_bio
,
2350 struct io_failure_record
*failrec
,
2351 struct page
*page
, int pg_offset
, int icsum
,
2352 bio_end_io_t
*endio_func
, void *data
)
2354 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2356 struct btrfs_io_bio
*btrfs_failed_bio
;
2357 struct btrfs_io_bio
*btrfs_bio
;
2359 bio
= btrfs_io_bio_alloc(GFP_NOFS
, 1);
2363 bio
->bi_end_io
= endio_func
;
2364 bio
->bi_iter
.bi_sector
= failrec
->logical
>> 9;
2365 bio
->bi_bdev
= fs_info
->fs_devices
->latest_bdev
;
2366 bio
->bi_iter
.bi_size
= 0;
2367 bio
->bi_private
= data
;
2369 btrfs_failed_bio
= btrfs_io_bio(failed_bio
);
2370 if (btrfs_failed_bio
->csum
) {
2371 u16 csum_size
= btrfs_super_csum_size(fs_info
->super_copy
);
2373 btrfs_bio
= btrfs_io_bio(bio
);
2374 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
2376 memcpy(btrfs_bio
->csum
, btrfs_failed_bio
->csum
+ icsum
,
2380 bio_add_page(bio
, page
, failrec
->len
, pg_offset
);
2386 * this is a generic handler for readpage errors (default
2387 * readpage_io_failed_hook). if other copies exist, read those and write back
2388 * good data to the failed position. does not investigate in remapping the
2389 * failed extent elsewhere, hoping the device will be smart enough to do this as
2393 static int bio_readpage_error(struct bio
*failed_bio
, u64 phy_offset
,
2394 struct page
*page
, u64 start
, u64 end
,
2397 struct io_failure_record
*failrec
;
2398 struct inode
*inode
= page
->mapping
->host
;
2399 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2404 BUG_ON(bio_op(failed_bio
) == REQ_OP_WRITE
);
2406 ret
= btrfs_get_io_failure_record(inode
, start
, end
, &failrec
);
2410 ret
= btrfs_check_repairable(inode
, failed_bio
, failrec
, failed_mirror
);
2412 free_io_failure(BTRFS_I(inode
), failrec
);
2416 if (failed_bio
->bi_vcnt
> 1)
2417 read_mode
|= REQ_FAILFAST_DEV
;
2419 phy_offset
>>= inode
->i_sb
->s_blocksize_bits
;
2420 bio
= btrfs_create_repair_bio(inode
, failed_bio
, failrec
, page
,
2421 start
- page_offset(page
),
2422 (int)phy_offset
, failed_bio
->bi_end_io
,
2425 free_io_failure(BTRFS_I(inode
), failrec
);
2428 bio_set_op_attrs(bio
, REQ_OP_READ
, read_mode
);
2430 btrfs_debug(btrfs_sb(inode
->i_sb
),
2431 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2432 read_mode
, failrec
->this_mirror
, failrec
->in_validation
);
2434 ret
= tree
->ops
->submit_bio_hook(inode
, bio
, failrec
->this_mirror
,
2435 failrec
->bio_flags
, 0);
2437 free_io_failure(BTRFS_I(inode
), failrec
);
2444 /* lots and lots of room for performance fixes in the end_bio funcs */
2446 void end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2448 int uptodate
= (err
== 0);
2449 struct extent_io_tree
*tree
;
2452 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2454 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2455 tree
->ops
->writepage_end_io_hook(page
, start
, end
, NULL
,
2459 ClearPageUptodate(page
);
2461 ret
= ret
< 0 ? ret
: -EIO
;
2462 mapping_set_error(page
->mapping
, ret
);
2467 * after a writepage IO is done, we need to:
2468 * clear the uptodate bits on error
2469 * clear the writeback bits in the extent tree for this IO
2470 * end_page_writeback if the page has no more pending IO
2472 * Scheduling is not allowed, so the extent state tree is expected
2473 * to have one and only one object corresponding to this IO.
2475 static void end_bio_extent_writepage(struct bio
*bio
)
2477 struct bio_vec
*bvec
;
2482 bio_for_each_segment_all(bvec
, bio
, i
) {
2483 struct page
*page
= bvec
->bv_page
;
2484 struct inode
*inode
= page
->mapping
->host
;
2485 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2487 /* We always issue full-page reads, but if some block
2488 * in a page fails to read, blk_update_request() will
2489 * advance bv_offset and adjust bv_len to compensate.
2490 * Print a warning for nonzero offsets, and an error
2491 * if they don't add up to a full page. */
2492 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_SIZE
) {
2493 if (bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_SIZE
)
2495 "partial page write in btrfs with offset %u and length %u",
2496 bvec
->bv_offset
, bvec
->bv_len
);
2499 "incomplete page write in btrfs with offset %u and length %u",
2500 bvec
->bv_offset
, bvec
->bv_len
);
2503 start
= page_offset(page
);
2504 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2506 end_extent_writepage(page
, bio
->bi_error
, start
, end
);
2507 end_page_writeback(page
);
2514 endio_readpage_release_extent(struct extent_io_tree
*tree
, u64 start
, u64 len
,
2517 struct extent_state
*cached
= NULL
;
2518 u64 end
= start
+ len
- 1;
2520 if (uptodate
&& tree
->track_uptodate
)
2521 set_extent_uptodate(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2522 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2526 * after a readpage IO is done, we need to:
2527 * clear the uptodate bits on error
2528 * set the uptodate bits if things worked
2529 * set the page up to date if all extents in the tree are uptodate
2530 * clear the lock bit in the extent tree
2531 * unlock the page if there are no other extents locked for it
2533 * Scheduling is not allowed, so the extent state tree is expected
2534 * to have one and only one object corresponding to this IO.
2536 static void end_bio_extent_readpage(struct bio
*bio
)
2538 struct bio_vec
*bvec
;
2539 int uptodate
= !bio
->bi_error
;
2540 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2541 struct extent_io_tree
*tree
;
2546 u64 extent_start
= 0;
2552 bio_for_each_segment_all(bvec
, bio
, i
) {
2553 struct page
*page
= bvec
->bv_page
;
2554 struct inode
*inode
= page
->mapping
->host
;
2555 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2557 btrfs_debug(fs_info
,
2558 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2559 (u64
)bio
->bi_iter
.bi_sector
, bio
->bi_error
,
2560 io_bio
->mirror_num
);
2561 tree
= &BTRFS_I(inode
)->io_tree
;
2563 /* We always issue full-page reads, but if some block
2564 * in a page fails to read, blk_update_request() will
2565 * advance bv_offset and adjust bv_len to compensate.
2566 * Print a warning for nonzero offsets, and an error
2567 * if they don't add up to a full page. */
2568 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_SIZE
) {
2569 if (bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_SIZE
)
2571 "partial page read in btrfs with offset %u and length %u",
2572 bvec
->bv_offset
, bvec
->bv_len
);
2575 "incomplete page read in btrfs with offset %u and length %u",
2576 bvec
->bv_offset
, bvec
->bv_len
);
2579 start
= page_offset(page
);
2580 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2583 mirror
= io_bio
->mirror_num
;
2584 if (likely(uptodate
&& tree
->ops
)) {
2585 ret
= tree
->ops
->readpage_end_io_hook(io_bio
, offset
,
2591 clean_io_failure(BTRFS_I(inode
), start
,
2595 if (likely(uptodate
))
2599 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2600 if (ret
== -EAGAIN
) {
2602 * Data inode's readpage_io_failed_hook() always
2605 * The generic bio_readpage_error handles errors
2606 * the following way: If possible, new read
2607 * requests are created and submitted and will
2608 * end up in end_bio_extent_readpage as well (if
2609 * we're lucky, not in the !uptodate case). In
2610 * that case it returns 0 and we just go on with
2611 * the next page in our bio. If it can't handle
2612 * the error it will return -EIO and we remain
2613 * responsible for that page.
2615 ret
= bio_readpage_error(bio
, offset
, page
,
2616 start
, end
, mirror
);
2618 uptodate
= !bio
->bi_error
;
2625 * metadata's readpage_io_failed_hook() always returns
2626 * -EIO and fixes nothing. -EIO is also returned if
2627 * data inode error could not be fixed.
2629 ASSERT(ret
== -EIO
);
2632 if (likely(uptodate
)) {
2633 loff_t i_size
= i_size_read(inode
);
2634 pgoff_t end_index
= i_size
>> PAGE_SHIFT
;
2637 /* Zero out the end if this page straddles i_size */
2638 off
= i_size
& (PAGE_SIZE
-1);
2639 if (page
->index
== end_index
&& off
)
2640 zero_user_segment(page
, off
, PAGE_SIZE
);
2641 SetPageUptodate(page
);
2643 ClearPageUptodate(page
);
2649 if (unlikely(!uptodate
)) {
2651 endio_readpage_release_extent(tree
,
2657 endio_readpage_release_extent(tree
, start
,
2658 end
- start
+ 1, 0);
2659 } else if (!extent_len
) {
2660 extent_start
= start
;
2661 extent_len
= end
+ 1 - start
;
2662 } else if (extent_start
+ extent_len
== start
) {
2663 extent_len
+= end
+ 1 - start
;
2665 endio_readpage_release_extent(tree
, extent_start
,
2666 extent_len
, uptodate
);
2667 extent_start
= start
;
2668 extent_len
= end
+ 1 - start
;
2673 endio_readpage_release_extent(tree
, extent_start
, extent_len
,
2676 io_bio
->end_io(io_bio
, bio
->bi_error
);
2681 * this allocates from the btrfs_bioset. We're returning a bio right now
2682 * but you can call btrfs_io_bio for the appropriate container_of magic
2685 btrfs_bio_alloc(struct block_device
*bdev
, u64 first_sector
, int nr_vecs
,
2688 struct btrfs_io_bio
*btrfs_bio
;
2691 bio
= bio_alloc_bioset(gfp_flags
, nr_vecs
, btrfs_bioset
);
2693 if (bio
== NULL
&& (current
->flags
& PF_MEMALLOC
)) {
2694 while (!bio
&& (nr_vecs
/= 2)) {
2695 bio
= bio_alloc_bioset(gfp_flags
,
2696 nr_vecs
, btrfs_bioset
);
2701 bio
->bi_bdev
= bdev
;
2702 bio
->bi_iter
.bi_sector
= first_sector
;
2703 btrfs_bio
= btrfs_io_bio(bio
);
2704 btrfs_bio
->csum
= NULL
;
2705 btrfs_bio
->csum_allocated
= NULL
;
2706 btrfs_bio
->end_io
= NULL
;
2711 struct bio
*btrfs_bio_clone(struct bio
*bio
, gfp_t gfp_mask
)
2713 struct btrfs_io_bio
*btrfs_bio
;
2716 new = bio_clone_bioset(bio
, gfp_mask
, btrfs_bioset
);
2718 btrfs_bio
= btrfs_io_bio(new);
2719 btrfs_bio
->csum
= NULL
;
2720 btrfs_bio
->csum_allocated
= NULL
;
2721 btrfs_bio
->end_io
= NULL
;
2726 /* this also allocates from the btrfs_bioset */
2727 struct bio
*btrfs_io_bio_alloc(gfp_t gfp_mask
, unsigned int nr_iovecs
)
2729 struct btrfs_io_bio
*btrfs_bio
;
2732 bio
= bio_alloc_bioset(gfp_mask
, nr_iovecs
, btrfs_bioset
);
2734 btrfs_bio
= btrfs_io_bio(bio
);
2735 btrfs_bio
->csum
= NULL
;
2736 btrfs_bio
->csum_allocated
= NULL
;
2737 btrfs_bio
->end_io
= NULL
;
2743 static int __must_check
submit_one_bio(struct bio
*bio
, int mirror_num
,
2744 unsigned long bio_flags
)
2747 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2748 struct page
*page
= bvec
->bv_page
;
2749 struct extent_io_tree
*tree
= bio
->bi_private
;
2752 start
= page_offset(page
) + bvec
->bv_offset
;
2754 bio
->bi_private
= NULL
;
2758 ret
= tree
->ops
->submit_bio_hook(page
->mapping
->host
, bio
,
2759 mirror_num
, bio_flags
, start
);
2761 btrfsic_submit_bio(bio
);
2767 static int merge_bio(struct extent_io_tree
*tree
, struct page
*page
,
2768 unsigned long offset
, size_t size
, struct bio
*bio
,
2769 unsigned long bio_flags
)
2773 ret
= tree
->ops
->merge_bio_hook(page
, offset
, size
, bio
,
2779 static int submit_extent_page(int op
, int op_flags
, struct extent_io_tree
*tree
,
2780 struct writeback_control
*wbc
,
2781 struct page
*page
, sector_t sector
,
2782 size_t size
, unsigned long offset
,
2783 struct block_device
*bdev
,
2784 struct bio
**bio_ret
,
2785 bio_end_io_t end_io_func
,
2787 unsigned long prev_bio_flags
,
2788 unsigned long bio_flags
,
2789 bool force_bio_submit
)
2794 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2795 size_t page_size
= min_t(size_t, size
, PAGE_SIZE
);
2797 if (bio_ret
&& *bio_ret
) {
2800 contig
= bio
->bi_iter
.bi_sector
== sector
;
2802 contig
= bio_end_sector(bio
) == sector
;
2804 if (prev_bio_flags
!= bio_flags
|| !contig
||
2806 merge_bio(tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2807 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2808 ret
= submit_one_bio(bio
, mirror_num
, prev_bio_flags
);
2816 wbc_account_io(wbc
, page
, page_size
);
2821 bio
= btrfs_bio_alloc(bdev
, sector
, BIO_MAX_PAGES
,
2822 GFP_NOFS
| __GFP_HIGH
);
2826 bio_add_page(bio
, page
, page_size
, offset
);
2827 bio
->bi_end_io
= end_io_func
;
2828 bio
->bi_private
= tree
;
2829 bio_set_op_attrs(bio
, op
, op_flags
);
2831 wbc_init_bio(wbc
, bio
);
2832 wbc_account_io(wbc
, page
, page_size
);
2838 ret
= submit_one_bio(bio
, mirror_num
, bio_flags
);
2843 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2846 if (!PagePrivate(page
)) {
2847 SetPagePrivate(page
);
2849 set_page_private(page
, (unsigned long)eb
);
2851 WARN_ON(page
->private != (unsigned long)eb
);
2855 void set_page_extent_mapped(struct page
*page
)
2857 if (!PagePrivate(page
)) {
2858 SetPagePrivate(page
);
2860 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2864 static struct extent_map
*
2865 __get_extent_map(struct inode
*inode
, struct page
*page
, size_t pg_offset
,
2866 u64 start
, u64 len
, get_extent_t
*get_extent
,
2867 struct extent_map
**em_cached
)
2869 struct extent_map
*em
;
2871 if (em_cached
&& *em_cached
) {
2873 if (extent_map_in_tree(em
) && start
>= em
->start
&&
2874 start
< extent_map_end(em
)) {
2875 refcount_inc(&em
->refs
);
2879 free_extent_map(em
);
2883 em
= get_extent(BTRFS_I(inode
), page
, pg_offset
, start
, len
, 0);
2884 if (em_cached
&& !IS_ERR_OR_NULL(em
)) {
2886 refcount_inc(&em
->refs
);
2892 * basic readpage implementation. Locked extent state structs are inserted
2893 * into the tree that are removed when the IO is done (by the end_io
2895 * XXX JDM: This needs looking at to ensure proper page locking
2896 * return 0 on success, otherwise return error
2898 static int __do_readpage(struct extent_io_tree
*tree
,
2900 get_extent_t
*get_extent
,
2901 struct extent_map
**em_cached
,
2902 struct bio
**bio
, int mirror_num
,
2903 unsigned long *bio_flags
, int read_flags
,
2906 struct inode
*inode
= page
->mapping
->host
;
2907 u64 start
= page_offset(page
);
2908 u64 page_end
= start
+ PAGE_SIZE
- 1;
2912 u64 last_byte
= i_size_read(inode
);
2916 struct extent_map
*em
;
2917 struct block_device
*bdev
;
2920 size_t pg_offset
= 0;
2922 size_t disk_io_size
;
2923 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2924 unsigned long this_bio_flag
= 0;
2926 set_page_extent_mapped(page
);
2929 if (!PageUptodate(page
)) {
2930 if (cleancache_get_page(page
) == 0) {
2931 BUG_ON(blocksize
!= PAGE_SIZE
);
2932 unlock_extent(tree
, start
, end
);
2937 if (page
->index
== last_byte
>> PAGE_SHIFT
) {
2939 size_t zero_offset
= last_byte
& (PAGE_SIZE
- 1);
2942 iosize
= PAGE_SIZE
- zero_offset
;
2943 userpage
= kmap_atomic(page
);
2944 memset(userpage
+ zero_offset
, 0, iosize
);
2945 flush_dcache_page(page
);
2946 kunmap_atomic(userpage
);
2949 while (cur
<= end
) {
2950 bool force_bio_submit
= false;
2952 if (cur
>= last_byte
) {
2954 struct extent_state
*cached
= NULL
;
2956 iosize
= PAGE_SIZE
- pg_offset
;
2957 userpage
= kmap_atomic(page
);
2958 memset(userpage
+ pg_offset
, 0, iosize
);
2959 flush_dcache_page(page
);
2960 kunmap_atomic(userpage
);
2961 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2963 unlock_extent_cached(tree
, cur
,
2968 em
= __get_extent_map(inode
, page
, pg_offset
, cur
,
2969 end
- cur
+ 1, get_extent
, em_cached
);
2970 if (IS_ERR_OR_NULL(em
)) {
2972 unlock_extent(tree
, cur
, end
);
2975 extent_offset
= cur
- em
->start
;
2976 BUG_ON(extent_map_end(em
) <= cur
);
2979 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2980 this_bio_flag
|= EXTENT_BIO_COMPRESSED
;
2981 extent_set_compress_type(&this_bio_flag
,
2985 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2986 cur_end
= min(extent_map_end(em
) - 1, end
);
2987 iosize
= ALIGN(iosize
, blocksize
);
2988 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2989 disk_io_size
= em
->block_len
;
2990 sector
= em
->block_start
>> 9;
2992 sector
= (em
->block_start
+ extent_offset
) >> 9;
2993 disk_io_size
= iosize
;
2996 block_start
= em
->block_start
;
2997 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2998 block_start
= EXTENT_MAP_HOLE
;
3001 * If we have a file range that points to a compressed extent
3002 * and it's followed by a consecutive file range that points to
3003 * to the same compressed extent (possibly with a different
3004 * offset and/or length, so it either points to the whole extent
3005 * or only part of it), we must make sure we do not submit a
3006 * single bio to populate the pages for the 2 ranges because
3007 * this makes the compressed extent read zero out the pages
3008 * belonging to the 2nd range. Imagine the following scenario:
3011 * [0 - 8K] [8K - 24K]
3014 * points to extent X, points to extent X,
3015 * offset 4K, length of 8K offset 0, length 16K
3017 * [extent X, compressed length = 4K uncompressed length = 16K]
3019 * If the bio to read the compressed extent covers both ranges,
3020 * it will decompress extent X into the pages belonging to the
3021 * first range and then it will stop, zeroing out the remaining
3022 * pages that belong to the other range that points to extent X.
3023 * So here we make sure we submit 2 bios, one for the first
3024 * range and another one for the third range. Both will target
3025 * the same physical extent from disk, but we can't currently
3026 * make the compressed bio endio callback populate the pages
3027 * for both ranges because each compressed bio is tightly
3028 * coupled with a single extent map, and each range can have
3029 * an extent map with a different offset value relative to the
3030 * uncompressed data of our extent and different lengths. This
3031 * is a corner case so we prioritize correctness over
3032 * non-optimal behavior (submitting 2 bios for the same extent).
3034 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
) &&
3035 prev_em_start
&& *prev_em_start
!= (u64
)-1 &&
3036 *prev_em_start
!= em
->orig_start
)
3037 force_bio_submit
= true;
3040 *prev_em_start
= em
->orig_start
;
3042 free_extent_map(em
);
3045 /* we've found a hole, just zero and go on */
3046 if (block_start
== EXTENT_MAP_HOLE
) {
3048 struct extent_state
*cached
= NULL
;
3050 userpage
= kmap_atomic(page
);
3051 memset(userpage
+ pg_offset
, 0, iosize
);
3052 flush_dcache_page(page
);
3053 kunmap_atomic(userpage
);
3055 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
3057 unlock_extent_cached(tree
, cur
,
3061 pg_offset
+= iosize
;
3064 /* the get_extent function already copied into the page */
3065 if (test_range_bit(tree
, cur
, cur_end
,
3066 EXTENT_UPTODATE
, 1, NULL
)) {
3067 check_page_uptodate(tree
, page
);
3068 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3070 pg_offset
+= iosize
;
3073 /* we have an inline extent but it didn't get marked up
3074 * to date. Error out
3076 if (block_start
== EXTENT_MAP_INLINE
) {
3078 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3080 pg_offset
+= iosize
;
3084 ret
= submit_extent_page(REQ_OP_READ
, read_flags
, tree
, NULL
,
3085 page
, sector
, disk_io_size
, pg_offset
,
3087 end_bio_extent_readpage
, mirror_num
,
3093 *bio_flags
= this_bio_flag
;
3096 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3100 pg_offset
+= iosize
;
3104 if (!PageError(page
))
3105 SetPageUptodate(page
);
3111 static inline void __do_contiguous_readpages(struct extent_io_tree
*tree
,
3112 struct page
*pages
[], int nr_pages
,
3114 get_extent_t
*get_extent
,
3115 struct extent_map
**em_cached
,
3116 struct bio
**bio
, int mirror_num
,
3117 unsigned long *bio_flags
,
3120 struct inode
*inode
;
3121 struct btrfs_ordered_extent
*ordered
;
3124 inode
= pages
[0]->mapping
->host
;
3126 lock_extent(tree
, start
, end
);
3127 ordered
= btrfs_lookup_ordered_range(BTRFS_I(inode
), start
,
3131 unlock_extent(tree
, start
, end
);
3132 btrfs_start_ordered_extent(inode
, ordered
, 1);
3133 btrfs_put_ordered_extent(ordered
);
3136 for (index
= 0; index
< nr_pages
; index
++) {
3137 __do_readpage(tree
, pages
[index
], get_extent
, em_cached
, bio
,
3138 mirror_num
, bio_flags
, 0, prev_em_start
);
3139 put_page(pages
[index
]);
3143 static void __extent_readpages(struct extent_io_tree
*tree
,
3144 struct page
*pages
[],
3145 int nr_pages
, get_extent_t
*get_extent
,
3146 struct extent_map
**em_cached
,
3147 struct bio
**bio
, int mirror_num
,
3148 unsigned long *bio_flags
,
3155 int first_index
= 0;
3157 for (index
= 0; index
< nr_pages
; index
++) {
3158 page_start
= page_offset(pages
[index
]);
3161 end
= start
+ PAGE_SIZE
- 1;
3162 first_index
= index
;
3163 } else if (end
+ 1 == page_start
) {
3166 __do_contiguous_readpages(tree
, &pages
[first_index
],
3167 index
- first_index
, start
,
3168 end
, get_extent
, em_cached
,
3169 bio
, mirror_num
, bio_flags
,
3172 end
= start
+ PAGE_SIZE
- 1;
3173 first_index
= index
;
3178 __do_contiguous_readpages(tree
, &pages
[first_index
],
3179 index
- first_index
, start
,
3180 end
, get_extent
, em_cached
, bio
,
3181 mirror_num
, bio_flags
,
3185 static int __extent_read_full_page(struct extent_io_tree
*tree
,
3187 get_extent_t
*get_extent
,
3188 struct bio
**bio
, int mirror_num
,
3189 unsigned long *bio_flags
, int read_flags
)
3191 struct inode
*inode
= page
->mapping
->host
;
3192 struct btrfs_ordered_extent
*ordered
;
3193 u64 start
= page_offset(page
);
3194 u64 end
= start
+ PAGE_SIZE
- 1;
3198 lock_extent(tree
, start
, end
);
3199 ordered
= btrfs_lookup_ordered_range(BTRFS_I(inode
), start
,
3203 unlock_extent(tree
, start
, end
);
3204 btrfs_start_ordered_extent(inode
, ordered
, 1);
3205 btrfs_put_ordered_extent(ordered
);
3208 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, bio
, mirror_num
,
3209 bio_flags
, read_flags
, NULL
);
3213 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3214 get_extent_t
*get_extent
, int mirror_num
)
3216 struct bio
*bio
= NULL
;
3217 unsigned long bio_flags
= 0;
3220 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
3223 ret
= submit_one_bio(bio
, mirror_num
, bio_flags
);
3227 static void update_nr_written(struct writeback_control
*wbc
,
3228 unsigned long nr_written
)
3230 wbc
->nr_to_write
-= nr_written
;
3234 * helper for __extent_writepage, doing all of the delayed allocation setup.
3236 * This returns 1 if our fill_delalloc function did all the work required
3237 * to write the page (copy into inline extent). In this case the IO has
3238 * been started and the page is already unlocked.
3240 * This returns 0 if all went well (page still locked)
3241 * This returns < 0 if there were errors (page still locked)
3243 static noinline_for_stack
int writepage_delalloc(struct inode
*inode
,
3244 struct page
*page
, struct writeback_control
*wbc
,
3245 struct extent_page_data
*epd
,
3247 unsigned long *nr_written
)
3249 struct extent_io_tree
*tree
= epd
->tree
;
3250 u64 page_end
= delalloc_start
+ PAGE_SIZE
- 1;
3252 u64 delalloc_to_write
= 0;
3253 u64 delalloc_end
= 0;
3255 int page_started
= 0;
3257 if (epd
->extent_locked
|| !tree
->ops
|| !tree
->ops
->fill_delalloc
)
3260 while (delalloc_end
< page_end
) {
3261 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
3265 BTRFS_MAX_EXTENT_SIZE
);
3266 if (nr_delalloc
== 0) {
3267 delalloc_start
= delalloc_end
+ 1;
3270 ret
= tree
->ops
->fill_delalloc(inode
, page
,
3275 /* File system has been set read-only */
3278 /* fill_delalloc should be return < 0 for error
3279 * but just in case, we use > 0 here meaning the
3280 * IO is started, so we don't want to return > 0
3281 * unless things are going well.
3283 ret
= ret
< 0 ? ret
: -EIO
;
3287 * delalloc_end is already one less than the total length, so
3288 * we don't subtract one from PAGE_SIZE
3290 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3291 PAGE_SIZE
) >> PAGE_SHIFT
;
3292 delalloc_start
= delalloc_end
+ 1;
3294 if (wbc
->nr_to_write
< delalloc_to_write
) {
3297 if (delalloc_to_write
< thresh
* 2)
3298 thresh
= delalloc_to_write
;
3299 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3303 /* did the fill delalloc function already unlock and start
3308 * we've unlocked the page, so we can't update
3309 * the mapping's writeback index, just update
3312 wbc
->nr_to_write
-= *nr_written
;
3323 * helper for __extent_writepage. This calls the writepage start hooks,
3324 * and does the loop to map the page into extents and bios.
3326 * We return 1 if the IO is started and the page is unlocked,
3327 * 0 if all went well (page still locked)
3328 * < 0 if there were errors (page still locked)
3330 static noinline_for_stack
int __extent_writepage_io(struct inode
*inode
,
3332 struct writeback_control
*wbc
,
3333 struct extent_page_data
*epd
,
3335 unsigned long nr_written
,
3336 int write_flags
, int *nr_ret
)
3338 struct extent_io_tree
*tree
= epd
->tree
;
3339 u64 start
= page_offset(page
);
3340 u64 page_end
= start
+ PAGE_SIZE
- 1;
3347 struct extent_map
*em
;
3348 struct block_device
*bdev
;
3349 size_t pg_offset
= 0;
3355 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3356 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3359 /* Fixup worker will requeue */
3361 wbc
->pages_skipped
++;
3363 redirty_page_for_writepage(wbc
, page
);
3365 update_nr_written(wbc
, nr_written
);
3372 * we don't want to touch the inode after unlocking the page,
3373 * so we update the mapping writeback index now
3375 update_nr_written(wbc
, nr_written
+ 1);
3378 if (i_size
<= start
) {
3379 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3380 tree
->ops
->writepage_end_io_hook(page
, start
,
3385 blocksize
= inode
->i_sb
->s_blocksize
;
3387 while (cur
<= end
) {
3390 if (cur
>= i_size
) {
3391 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3392 tree
->ops
->writepage_end_io_hook(page
, cur
,
3396 em
= epd
->get_extent(BTRFS_I(inode
), page
, pg_offset
, cur
,
3398 if (IS_ERR_OR_NULL(em
)) {
3400 ret
= PTR_ERR_OR_ZERO(em
);
3404 extent_offset
= cur
- em
->start
;
3405 em_end
= extent_map_end(em
);
3406 BUG_ON(em_end
<= cur
);
3408 iosize
= min(em_end
- cur
, end
- cur
+ 1);
3409 iosize
= ALIGN(iosize
, blocksize
);
3410 sector
= (em
->block_start
+ extent_offset
) >> 9;
3412 block_start
= em
->block_start
;
3413 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3414 free_extent_map(em
);
3418 * compressed and inline extents are written through other
3421 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3422 block_start
== EXTENT_MAP_INLINE
) {
3424 * end_io notification does not happen here for
3425 * compressed extents
3427 if (!compressed
&& tree
->ops
&&
3428 tree
->ops
->writepage_end_io_hook
)
3429 tree
->ops
->writepage_end_io_hook(page
, cur
,
3432 else if (compressed
) {
3433 /* we don't want to end_page_writeback on
3434 * a compressed extent. this happens
3441 pg_offset
+= iosize
;
3445 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3446 if (!PageWriteback(page
)) {
3447 btrfs_err(BTRFS_I(inode
)->root
->fs_info
,
3448 "page %lu not writeback, cur %llu end %llu",
3449 page
->index
, cur
, end
);
3452 ret
= submit_extent_page(REQ_OP_WRITE
, write_flags
, tree
, wbc
,
3453 page
, sector
, iosize
, pg_offset
,
3455 end_bio_extent_writepage
,
3459 if (PageWriteback(page
))
3460 end_page_writeback(page
);
3464 pg_offset
+= iosize
;
3473 * the writepage semantics are similar to regular writepage. extent
3474 * records are inserted to lock ranges in the tree, and as dirty areas
3475 * are found, they are marked writeback. Then the lock bits are removed
3476 * and the end_io handler clears the writeback ranges
3478 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
3481 struct inode
*inode
= page
->mapping
->host
;
3482 struct extent_page_data
*epd
= data
;
3483 u64 start
= page_offset(page
);
3484 u64 page_end
= start
+ PAGE_SIZE
- 1;
3487 size_t pg_offset
= 0;
3488 loff_t i_size
= i_size_read(inode
);
3489 unsigned long end_index
= i_size
>> PAGE_SHIFT
;
3490 int write_flags
= 0;
3491 unsigned long nr_written
= 0;
3493 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3494 write_flags
= REQ_SYNC
;
3496 trace___extent_writepage(page
, inode
, wbc
);
3498 WARN_ON(!PageLocked(page
));
3500 ClearPageError(page
);
3502 pg_offset
= i_size
& (PAGE_SIZE
- 1);
3503 if (page
->index
> end_index
||
3504 (page
->index
== end_index
&& !pg_offset
)) {
3505 page
->mapping
->a_ops
->invalidatepage(page
, 0, PAGE_SIZE
);
3510 if (page
->index
== end_index
) {
3513 userpage
= kmap_atomic(page
);
3514 memset(userpage
+ pg_offset
, 0,
3515 PAGE_SIZE
- pg_offset
);
3516 kunmap_atomic(userpage
);
3517 flush_dcache_page(page
);
3522 set_page_extent_mapped(page
);
3524 ret
= writepage_delalloc(inode
, page
, wbc
, epd
, start
, &nr_written
);
3530 ret
= __extent_writepage_io(inode
, page
, wbc
, epd
,
3531 i_size
, nr_written
, write_flags
, &nr
);
3537 /* make sure the mapping tag for page dirty gets cleared */
3538 set_page_writeback(page
);
3539 end_page_writeback(page
);
3541 if (PageError(page
)) {
3542 ret
= ret
< 0 ? ret
: -EIO
;
3543 end_extent_writepage(page
, ret
, start
, page_end
);
3552 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3554 wait_on_bit_io(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
,
3555 TASK_UNINTERRUPTIBLE
);
3558 static noinline_for_stack
int
3559 lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3560 struct btrfs_fs_info
*fs_info
,
3561 struct extent_page_data
*epd
)
3563 unsigned long i
, num_pages
;
3567 if (!btrfs_try_tree_write_lock(eb
)) {
3569 flush_write_bio(epd
);
3570 btrfs_tree_lock(eb
);
3573 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3574 btrfs_tree_unlock(eb
);
3578 flush_write_bio(epd
);
3582 wait_on_extent_buffer_writeback(eb
);
3583 btrfs_tree_lock(eb
);
3584 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3586 btrfs_tree_unlock(eb
);
3591 * We need to do this to prevent races in people who check if the eb is
3592 * under IO since we can end up having no IO bits set for a short period
3595 spin_lock(&eb
->refs_lock
);
3596 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3597 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3598 spin_unlock(&eb
->refs_lock
);
3599 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3600 __percpu_counter_add(&fs_info
->dirty_metadata_bytes
,
3602 fs_info
->dirty_metadata_batch
);
3605 spin_unlock(&eb
->refs_lock
);
3608 btrfs_tree_unlock(eb
);
3613 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3614 for (i
= 0; i
< num_pages
; i
++) {
3615 struct page
*p
= eb
->pages
[i
];
3617 if (!trylock_page(p
)) {
3619 flush_write_bio(epd
);
3629 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3631 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3632 smp_mb__after_atomic();
3633 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3636 static void set_btree_ioerr(struct page
*page
)
3638 struct extent_buffer
*eb
= (struct extent_buffer
*)page
->private;
3641 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
))
3645 * If writeback for a btree extent that doesn't belong to a log tree
3646 * failed, increment the counter transaction->eb_write_errors.
3647 * We do this because while the transaction is running and before it's
3648 * committing (when we call filemap_fdata[write|wait]_range against
3649 * the btree inode), we might have
3650 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3651 * returns an error or an error happens during writeback, when we're
3652 * committing the transaction we wouldn't know about it, since the pages
3653 * can be no longer dirty nor marked anymore for writeback (if a
3654 * subsequent modification to the extent buffer didn't happen before the
3655 * transaction commit), which makes filemap_fdata[write|wait]_range not
3656 * able to find the pages tagged with SetPageError at transaction
3657 * commit time. So if this happens we must abort the transaction,
3658 * otherwise we commit a super block with btree roots that point to
3659 * btree nodes/leafs whose content on disk is invalid - either garbage
3660 * or the content of some node/leaf from a past generation that got
3661 * cowed or deleted and is no longer valid.
3663 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3664 * not be enough - we need to distinguish between log tree extents vs
3665 * non-log tree extents, and the next filemap_fdatawait_range() call
3666 * will catch and clear such errors in the mapping - and that call might
3667 * be from a log sync and not from a transaction commit. Also, checking
3668 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3669 * not done and would not be reliable - the eb might have been released
3670 * from memory and reading it back again means that flag would not be
3671 * set (since it's a runtime flag, not persisted on disk).
3673 * Using the flags below in the btree inode also makes us achieve the
3674 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3675 * writeback for all dirty pages and before filemap_fdatawait_range()
3676 * is called, the writeback for all dirty pages had already finished
3677 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3678 * filemap_fdatawait_range() would return success, as it could not know
3679 * that writeback errors happened (the pages were no longer tagged for
3682 switch (eb
->log_index
) {
3684 set_bit(BTRFS_FS_BTREE_ERR
, &eb
->fs_info
->flags
);
3687 set_bit(BTRFS_FS_LOG1_ERR
, &eb
->fs_info
->flags
);
3690 set_bit(BTRFS_FS_LOG2_ERR
, &eb
->fs_info
->flags
);
3693 BUG(); /* unexpected, logic error */
3697 static void end_bio_extent_buffer_writepage(struct bio
*bio
)
3699 struct bio_vec
*bvec
;
3700 struct extent_buffer
*eb
;
3703 bio_for_each_segment_all(bvec
, bio
, i
) {
3704 struct page
*page
= bvec
->bv_page
;
3706 eb
= (struct extent_buffer
*)page
->private;
3708 done
= atomic_dec_and_test(&eb
->io_pages
);
3710 if (bio
->bi_error
||
3711 test_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
)) {
3712 ClearPageUptodate(page
);
3713 set_btree_ioerr(page
);
3716 end_page_writeback(page
);
3721 end_extent_buffer_writeback(eb
);
3727 static noinline_for_stack
int write_one_eb(struct extent_buffer
*eb
,
3728 struct btrfs_fs_info
*fs_info
,
3729 struct writeback_control
*wbc
,
3730 struct extent_page_data
*epd
)
3732 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3733 struct extent_io_tree
*tree
= &BTRFS_I(fs_info
->btree_inode
)->io_tree
;
3734 u64 offset
= eb
->start
;
3736 unsigned long i
, num_pages
;
3737 unsigned long bio_flags
= 0;
3738 unsigned long start
, end
;
3739 int write_flags
= (epd
->sync_io
? REQ_SYNC
: 0) | REQ_META
;
3742 clear_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
);
3743 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3744 atomic_set(&eb
->io_pages
, num_pages
);
3745 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3746 bio_flags
= EXTENT_BIO_TREE_LOG
;
3748 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3749 nritems
= btrfs_header_nritems(eb
);
3750 if (btrfs_header_level(eb
) > 0) {
3751 end
= btrfs_node_key_ptr_offset(nritems
);
3753 memzero_extent_buffer(eb
, end
, eb
->len
- end
);
3757 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3759 start
= btrfs_item_nr_offset(nritems
);
3760 end
= btrfs_leaf_data(eb
) + leaf_data_end(fs_info
, eb
);
3761 memzero_extent_buffer(eb
, start
, end
- start
);
3764 for (i
= 0; i
< num_pages
; i
++) {
3765 struct page
*p
= eb
->pages
[i
];
3767 clear_page_dirty_for_io(p
);
3768 set_page_writeback(p
);
3769 ret
= submit_extent_page(REQ_OP_WRITE
, write_flags
, tree
, wbc
,
3770 p
, offset
>> 9, PAGE_SIZE
, 0, bdev
,
3772 end_bio_extent_buffer_writepage
,
3773 0, epd
->bio_flags
, bio_flags
, false);
3774 epd
->bio_flags
= bio_flags
;
3777 if (PageWriteback(p
))
3778 end_page_writeback(p
);
3779 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3780 end_extent_buffer_writeback(eb
);
3784 offset
+= PAGE_SIZE
;
3785 update_nr_written(wbc
, 1);
3789 if (unlikely(ret
)) {
3790 for (; i
< num_pages
; i
++) {
3791 struct page
*p
= eb
->pages
[i
];
3792 clear_page_dirty_for_io(p
);
3800 int btree_write_cache_pages(struct address_space
*mapping
,
3801 struct writeback_control
*wbc
)
3803 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3804 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3805 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3806 struct extent_page_data epd
= {
3810 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3815 int nr_to_write_done
= 0;
3816 struct pagevec pvec
;
3819 pgoff_t end
; /* Inclusive */
3823 pagevec_init(&pvec
, 0);
3824 if (wbc
->range_cyclic
) {
3825 index
= mapping
->writeback_index
; /* Start from prev offset */
3828 index
= wbc
->range_start
>> PAGE_SHIFT
;
3829 end
= wbc
->range_end
>> PAGE_SHIFT
;
3832 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3833 tag
= PAGECACHE_TAG_TOWRITE
;
3835 tag
= PAGECACHE_TAG_DIRTY
;
3837 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3838 tag_pages_for_writeback(mapping
, index
, end
);
3839 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3840 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3841 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3845 for (i
= 0; i
< nr_pages
; i
++) {
3846 struct page
*page
= pvec
.pages
[i
];
3848 if (!PagePrivate(page
))
3851 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3856 spin_lock(&mapping
->private_lock
);
3857 if (!PagePrivate(page
)) {
3858 spin_unlock(&mapping
->private_lock
);
3862 eb
= (struct extent_buffer
*)page
->private;
3865 * Shouldn't happen and normally this would be a BUG_ON
3866 * but no sense in crashing the users box for something
3867 * we can survive anyway.
3870 spin_unlock(&mapping
->private_lock
);
3874 if (eb
== prev_eb
) {
3875 spin_unlock(&mapping
->private_lock
);
3879 ret
= atomic_inc_not_zero(&eb
->refs
);
3880 spin_unlock(&mapping
->private_lock
);
3885 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3887 free_extent_buffer(eb
);
3891 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3894 free_extent_buffer(eb
);
3897 free_extent_buffer(eb
);
3900 * the filesystem may choose to bump up nr_to_write.
3901 * We have to make sure to honor the new nr_to_write
3904 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3906 pagevec_release(&pvec
);
3909 if (!scanned
&& !done
) {
3911 * We hit the last page and there is more work to be done: wrap
3912 * back to the start of the file
3918 flush_write_bio(&epd
);
3923 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3924 * @mapping: address space structure to write
3925 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3926 * @writepage: function called for each page
3927 * @data: data passed to writepage function
3929 * If a page is already under I/O, write_cache_pages() skips it, even
3930 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3931 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3932 * and msync() need to guarantee that all the data which was dirty at the time
3933 * the call was made get new I/O started against them. If wbc->sync_mode is
3934 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3935 * existing IO to complete.
3937 static int extent_write_cache_pages(struct address_space
*mapping
,
3938 struct writeback_control
*wbc
,
3939 writepage_t writepage
, void *data
,
3940 void (*flush_fn
)(void *))
3942 struct inode
*inode
= mapping
->host
;
3945 int nr_to_write_done
= 0;
3946 struct pagevec pvec
;
3949 pgoff_t end
; /* Inclusive */
3951 int range_whole
= 0;
3956 * We have to hold onto the inode so that ordered extents can do their
3957 * work when the IO finishes. The alternative to this is failing to add
3958 * an ordered extent if the igrab() fails there and that is a huge pain
3959 * to deal with, so instead just hold onto the inode throughout the
3960 * writepages operation. If it fails here we are freeing up the inode
3961 * anyway and we'd rather not waste our time writing out stuff that is
3962 * going to be truncated anyway.
3967 pagevec_init(&pvec
, 0);
3968 if (wbc
->range_cyclic
) {
3969 index
= mapping
->writeback_index
; /* Start from prev offset */
3972 index
= wbc
->range_start
>> PAGE_SHIFT
;
3973 end
= wbc
->range_end
>> PAGE_SHIFT
;
3974 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
3978 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3979 tag
= PAGECACHE_TAG_TOWRITE
;
3981 tag
= PAGECACHE_TAG_DIRTY
;
3983 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3984 tag_pages_for_writeback(mapping
, index
, end
);
3986 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3987 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3988 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3992 for (i
= 0; i
< nr_pages
; i
++) {
3993 struct page
*page
= pvec
.pages
[i
];
3995 done_index
= page
->index
;
3997 * At this point we hold neither mapping->tree_lock nor
3998 * lock on the page itself: the page may be truncated or
3999 * invalidated (changing page->mapping to NULL), or even
4000 * swizzled back from swapper_space to tmpfs file
4003 if (!trylock_page(page
)) {
4008 if (unlikely(page
->mapping
!= mapping
)) {
4013 if (!wbc
->range_cyclic
&& page
->index
> end
) {
4019 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
4020 if (PageWriteback(page
))
4022 wait_on_page_writeback(page
);
4025 if (PageWriteback(page
) ||
4026 !clear_page_dirty_for_io(page
)) {
4031 ret
= (*writepage
)(page
, wbc
, data
);
4033 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
4039 * done_index is set past this page,
4040 * so media errors will not choke
4041 * background writeout for the entire
4042 * file. This has consequences for
4043 * range_cyclic semantics (ie. it may
4044 * not be suitable for data integrity
4047 done_index
= page
->index
+ 1;
4053 * the filesystem may choose to bump up nr_to_write.
4054 * We have to make sure to honor the new nr_to_write
4057 nr_to_write_done
= wbc
->nr_to_write
<= 0;
4059 pagevec_release(&pvec
);
4062 if (!scanned
&& !done
) {
4064 * We hit the last page and there is more work to be done: wrap
4065 * back to the start of the file
4072 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 && range_whole
))
4073 mapping
->writeback_index
= done_index
;
4075 btrfs_add_delayed_iput(inode
);
4079 static void flush_epd_write_bio(struct extent_page_data
*epd
)
4084 bio_set_op_attrs(epd
->bio
, REQ_OP_WRITE
,
4085 epd
->sync_io
? REQ_SYNC
: 0);
4087 ret
= submit_one_bio(epd
->bio
, 0, epd
->bio_flags
);
4088 BUG_ON(ret
< 0); /* -ENOMEM */
4093 static noinline
void flush_write_bio(void *data
)
4095 struct extent_page_data
*epd
= data
;
4096 flush_epd_write_bio(epd
);
4099 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
4100 get_extent_t
*get_extent
,
4101 struct writeback_control
*wbc
)
4104 struct extent_page_data epd
= {
4107 .get_extent
= get_extent
,
4109 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
4113 ret
= __extent_writepage(page
, wbc
, &epd
);
4115 flush_epd_write_bio(&epd
);
4119 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
4120 u64 start
, u64 end
, get_extent_t
*get_extent
,
4124 struct address_space
*mapping
= inode
->i_mapping
;
4126 unsigned long nr_pages
= (end
- start
+ PAGE_SIZE
) >>
4129 struct extent_page_data epd
= {
4132 .get_extent
= get_extent
,
4134 .sync_io
= mode
== WB_SYNC_ALL
,
4137 struct writeback_control wbc_writepages
= {
4139 .nr_to_write
= nr_pages
* 2,
4140 .range_start
= start
,
4141 .range_end
= end
+ 1,
4144 while (start
<= end
) {
4145 page
= find_get_page(mapping
, start
>> PAGE_SHIFT
);
4146 if (clear_page_dirty_for_io(page
))
4147 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
4149 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
4150 tree
->ops
->writepage_end_io_hook(page
, start
,
4151 start
+ PAGE_SIZE
- 1,
4159 flush_epd_write_bio(&epd
);
4163 int extent_writepages(struct extent_io_tree
*tree
,
4164 struct address_space
*mapping
,
4165 get_extent_t
*get_extent
,
4166 struct writeback_control
*wbc
)
4169 struct extent_page_data epd
= {
4172 .get_extent
= get_extent
,
4174 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
4178 ret
= extent_write_cache_pages(mapping
, wbc
, __extent_writepage
, &epd
,
4180 flush_epd_write_bio(&epd
);
4184 int extent_readpages(struct extent_io_tree
*tree
,
4185 struct address_space
*mapping
,
4186 struct list_head
*pages
, unsigned nr_pages
,
4187 get_extent_t get_extent
)
4189 struct bio
*bio
= NULL
;
4191 unsigned long bio_flags
= 0;
4192 struct page
*pagepool
[16];
4194 struct extent_map
*em_cached
= NULL
;
4196 u64 prev_em_start
= (u64
)-1;
4198 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
4199 page
= list_entry(pages
->prev
, struct page
, lru
);
4201 prefetchw(&page
->flags
);
4202 list_del(&page
->lru
);
4203 if (add_to_page_cache_lru(page
, mapping
,
4205 readahead_gfp_mask(mapping
))) {
4210 pagepool
[nr
++] = page
;
4211 if (nr
< ARRAY_SIZE(pagepool
))
4213 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
4214 &bio
, 0, &bio_flags
, &prev_em_start
);
4218 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
4219 &bio
, 0, &bio_flags
, &prev_em_start
);
4222 free_extent_map(em_cached
);
4224 BUG_ON(!list_empty(pages
));
4226 return submit_one_bio(bio
, 0, bio_flags
);
4231 * basic invalidatepage code, this waits on any locked or writeback
4232 * ranges corresponding to the page, and then deletes any extent state
4233 * records from the tree
4235 int extent_invalidatepage(struct extent_io_tree
*tree
,
4236 struct page
*page
, unsigned long offset
)
4238 struct extent_state
*cached_state
= NULL
;
4239 u64 start
= page_offset(page
);
4240 u64 end
= start
+ PAGE_SIZE
- 1;
4241 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
4243 start
+= ALIGN(offset
, blocksize
);
4247 lock_extent_bits(tree
, start
, end
, &cached_state
);
4248 wait_on_page_writeback(page
);
4249 clear_extent_bit(tree
, start
, end
,
4250 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
4251 EXTENT_DO_ACCOUNTING
,
4252 1, 1, &cached_state
, GFP_NOFS
);
4257 * a helper for releasepage, this tests for areas of the page that
4258 * are locked or under IO and drops the related state bits if it is safe
4261 static int try_release_extent_state(struct extent_map_tree
*map
,
4262 struct extent_io_tree
*tree
,
4263 struct page
*page
, gfp_t mask
)
4265 u64 start
= page_offset(page
);
4266 u64 end
= start
+ PAGE_SIZE
- 1;
4269 if (test_range_bit(tree
, start
, end
,
4270 EXTENT_IOBITS
, 0, NULL
))
4274 * at this point we can safely clear everything except the
4275 * locked bit and the nodatasum bit
4277 ret
= clear_extent_bit(tree
, start
, end
,
4278 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
4281 /* if clear_extent_bit failed for enomem reasons,
4282 * we can't allow the release to continue.
4293 * a helper for releasepage. As long as there are no locked extents
4294 * in the range corresponding to the page, both state records and extent
4295 * map records are removed
4297 int try_release_extent_mapping(struct extent_map_tree
*map
,
4298 struct extent_io_tree
*tree
, struct page
*page
,
4301 struct extent_map
*em
;
4302 u64 start
= page_offset(page
);
4303 u64 end
= start
+ PAGE_SIZE
- 1;
4305 if (gfpflags_allow_blocking(mask
) &&
4306 page
->mapping
->host
->i_size
> SZ_16M
) {
4308 while (start
<= end
) {
4309 len
= end
- start
+ 1;
4310 write_lock(&map
->lock
);
4311 em
= lookup_extent_mapping(map
, start
, len
);
4313 write_unlock(&map
->lock
);
4316 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
4317 em
->start
!= start
) {
4318 write_unlock(&map
->lock
);
4319 free_extent_map(em
);
4322 if (!test_range_bit(tree
, em
->start
,
4323 extent_map_end(em
) - 1,
4324 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
4326 remove_extent_mapping(map
, em
);
4327 /* once for the rb tree */
4328 free_extent_map(em
);
4330 start
= extent_map_end(em
);
4331 write_unlock(&map
->lock
);
4334 free_extent_map(em
);
4337 return try_release_extent_state(map
, tree
, page
, mask
);
4341 * helper function for fiemap, which doesn't want to see any holes.
4342 * This maps until we find something past 'last'
4344 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
4347 get_extent_t
*get_extent
)
4349 u64 sectorsize
= btrfs_inode_sectorsize(inode
);
4350 struct extent_map
*em
;
4357 len
= last
- offset
;
4360 len
= ALIGN(len
, sectorsize
);
4361 em
= get_extent(BTRFS_I(inode
), NULL
, 0, offset
, len
, 0);
4362 if (IS_ERR_OR_NULL(em
))
4365 /* if this isn't a hole return it */
4366 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
4367 em
->block_start
!= EXTENT_MAP_HOLE
) {
4371 /* this is a hole, advance to the next extent */
4372 offset
= extent_map_end(em
);
4373 free_extent_map(em
);
4381 * To cache previous fiemap extent
4383 * Will be used for merging fiemap extent
4385 struct fiemap_cache
{
4394 * Helper to submit fiemap extent.
4396 * Will try to merge current fiemap extent specified by @offset, @phys,
4397 * @len and @flags with cached one.
4398 * And only when we fails to merge, cached one will be submitted as
4401 * Return value is the same as fiemap_fill_next_extent().
4403 static int emit_fiemap_extent(struct fiemap_extent_info
*fieinfo
,
4404 struct fiemap_cache
*cache
,
4405 u64 offset
, u64 phys
, u64 len
, u32 flags
)
4413 * Sanity check, extent_fiemap() should have ensured that new
4414 * fiemap extent won't overlap with cahced one.
4417 * NOTE: Physical address can overlap, due to compression
4419 if (cache
->offset
+ cache
->len
> offset
) {
4425 * Only merges fiemap extents if
4426 * 1) Their logical addresses are continuous
4428 * 2) Their physical addresses are continuous
4429 * So truly compressed (physical size smaller than logical size)
4430 * extents won't get merged with each other
4432 * 3) Share same flags except FIEMAP_EXTENT_LAST
4433 * So regular extent won't get merged with prealloc extent
4435 if (cache
->offset
+ cache
->len
== offset
&&
4436 cache
->phys
+ cache
->len
== phys
&&
4437 (cache
->flags
& ~FIEMAP_EXTENT_LAST
) ==
4438 (flags
& ~FIEMAP_EXTENT_LAST
)) {
4440 cache
->flags
|= flags
;
4441 goto try_submit_last
;
4444 /* Not mergeable, need to submit cached one */
4445 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
, cache
->phys
,
4446 cache
->len
, cache
->flags
);
4447 cache
->cached
= false;
4451 cache
->cached
= true;
4452 cache
->offset
= offset
;
4455 cache
->flags
= flags
;
4457 if (cache
->flags
& FIEMAP_EXTENT_LAST
) {
4458 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
,
4459 cache
->phys
, cache
->len
, cache
->flags
);
4460 cache
->cached
= false;
4466 * Sanity check for fiemap cache
4468 * All fiemap cache should be submitted by emit_fiemap_extent()
4469 * Iteration should be terminated either by last fiemap extent or
4470 * fieinfo->fi_extents_max.
4471 * So no cached fiemap should exist.
4473 static int check_fiemap_cache(struct btrfs_fs_info
*fs_info
,
4474 struct fiemap_extent_info
*fieinfo
,
4475 struct fiemap_cache
*cache
)
4482 /* Small and recoverbale problem, only to info developer */
4483 #ifdef CONFIG_BTRFS_DEBUG
4487 "unhandled fiemap cache detected: offset=%llu phys=%llu len=%llu flags=0x%x",
4488 cache
->offset
, cache
->phys
, cache
->len
, cache
->flags
);
4489 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
, cache
->phys
,
4490 cache
->len
, cache
->flags
);
4491 cache
->cached
= false;
4497 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4498 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
4502 u64 max
= start
+ len
;
4506 u64 last_for_get_extent
= 0;
4508 u64 isize
= i_size_read(inode
);
4509 struct btrfs_key found_key
;
4510 struct extent_map
*em
= NULL
;
4511 struct extent_state
*cached_state
= NULL
;
4512 struct btrfs_path
*path
;
4513 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4514 struct fiemap_cache cache
= { 0 };
4523 path
= btrfs_alloc_path();
4526 path
->leave_spinning
= 1;
4528 start
= round_down(start
, btrfs_inode_sectorsize(inode
));
4529 len
= round_up(max
, btrfs_inode_sectorsize(inode
)) - start
;
4532 * lookup the last file extent. We're not using i_size here
4533 * because there might be preallocation past i_size
4535 ret
= btrfs_lookup_file_extent(NULL
, root
, path
,
4536 btrfs_ino(BTRFS_I(inode
)), -1, 0);
4538 btrfs_free_path(path
);
4547 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
4548 found_type
= found_key
.type
;
4550 /* No extents, but there might be delalloc bits */
4551 if (found_key
.objectid
!= btrfs_ino(BTRFS_I(inode
)) ||
4552 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
4553 /* have to trust i_size as the end */
4555 last_for_get_extent
= isize
;
4558 * remember the start of the last extent. There are a
4559 * bunch of different factors that go into the length of the
4560 * extent, so its much less complex to remember where it started
4562 last
= found_key
.offset
;
4563 last_for_get_extent
= last
+ 1;
4565 btrfs_release_path(path
);
4568 * we might have some extents allocated but more delalloc past those
4569 * extents. so, we trust isize unless the start of the last extent is
4574 last_for_get_extent
= isize
;
4577 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4580 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4590 u64 offset_in_extent
= 0;
4592 /* break if the extent we found is outside the range */
4593 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4597 * get_extent may return an extent that starts before our
4598 * requested range. We have to make sure the ranges
4599 * we return to fiemap always move forward and don't
4600 * overlap, so adjust the offsets here
4602 em_start
= max(em
->start
, off
);
4605 * record the offset from the start of the extent
4606 * for adjusting the disk offset below. Only do this if the
4607 * extent isn't compressed since our in ram offset may be past
4608 * what we have actually allocated on disk.
4610 if (!test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4611 offset_in_extent
= em_start
- em
->start
;
4612 em_end
= extent_map_end(em
);
4613 em_len
= em_end
- em_start
;
4618 * bump off for our next call to get_extent
4620 off
= extent_map_end(em
);
4624 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4626 flags
|= FIEMAP_EXTENT_LAST
;
4627 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4628 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4629 FIEMAP_EXTENT_NOT_ALIGNED
);
4630 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4631 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4632 FIEMAP_EXTENT_UNKNOWN
);
4633 } else if (fieinfo
->fi_extents_max
) {
4634 struct btrfs_trans_handle
*trans
;
4636 u64 bytenr
= em
->block_start
-
4637 (em
->start
- em
->orig_start
);
4639 disko
= em
->block_start
+ offset_in_extent
;
4642 * We need a trans handle to get delayed refs
4644 trans
= btrfs_join_transaction(root
);
4646 * It's OK if we can't start a trans we can still check
4653 * As btrfs supports shared space, this information
4654 * can be exported to userspace tools via
4655 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4656 * then we're just getting a count and we can skip the
4659 ret
= btrfs_check_shared(trans
, root
->fs_info
,
4661 btrfs_ino(BTRFS_I(inode
)), bytenr
);
4663 btrfs_end_transaction(trans
);
4667 flags
|= FIEMAP_EXTENT_SHARED
;
4670 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4671 flags
|= FIEMAP_EXTENT_ENCODED
;
4672 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
4673 flags
|= FIEMAP_EXTENT_UNWRITTEN
;
4675 free_extent_map(em
);
4677 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4678 (last
== (u64
)-1 && isize
<= em_end
)) {
4679 flags
|= FIEMAP_EXTENT_LAST
;
4683 /* now scan forward to see if this is really the last extent. */
4684 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4691 flags
|= FIEMAP_EXTENT_LAST
;
4694 ret
= emit_fiemap_extent(fieinfo
, &cache
, em_start
, disko
,
4704 ret
= check_fiemap_cache(root
->fs_info
, fieinfo
, &cache
);
4705 free_extent_map(em
);
4707 btrfs_free_path(path
);
4708 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4709 &cached_state
, GFP_NOFS
);
4713 static void __free_extent_buffer(struct extent_buffer
*eb
)
4715 btrfs_leak_debug_del(&eb
->leak_list
);
4716 kmem_cache_free(extent_buffer_cache
, eb
);
4719 int extent_buffer_under_io(struct extent_buffer
*eb
)
4721 return (atomic_read(&eb
->io_pages
) ||
4722 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4723 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4727 * Helper for releasing extent buffer page.
4729 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
)
4731 unsigned long index
;
4733 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4735 BUG_ON(extent_buffer_under_io(eb
));
4737 index
= num_extent_pages(eb
->start
, eb
->len
);
4743 page
= eb
->pages
[index
];
4747 spin_lock(&page
->mapping
->private_lock
);
4749 * We do this since we'll remove the pages after we've
4750 * removed the eb from the radix tree, so we could race
4751 * and have this page now attached to the new eb. So
4752 * only clear page_private if it's still connected to
4755 if (PagePrivate(page
) &&
4756 page
->private == (unsigned long)eb
) {
4757 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4758 BUG_ON(PageDirty(page
));
4759 BUG_ON(PageWriteback(page
));
4761 * We need to make sure we haven't be attached
4764 ClearPagePrivate(page
);
4765 set_page_private(page
, 0);
4766 /* One for the page private */
4771 spin_unlock(&page
->mapping
->private_lock
);
4773 /* One for when we allocated the page */
4775 } while (index
!= 0);
4779 * Helper for releasing the extent buffer.
4781 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4783 btrfs_release_extent_buffer_page(eb
);
4784 __free_extent_buffer(eb
);
4787 static struct extent_buffer
*
4788 __alloc_extent_buffer(struct btrfs_fs_info
*fs_info
, u64 start
,
4791 struct extent_buffer
*eb
= NULL
;
4793 eb
= kmem_cache_zalloc(extent_buffer_cache
, GFP_NOFS
|__GFP_NOFAIL
);
4796 eb
->fs_info
= fs_info
;
4798 rwlock_init(&eb
->lock
);
4799 atomic_set(&eb
->write_locks
, 0);
4800 atomic_set(&eb
->read_locks
, 0);
4801 atomic_set(&eb
->blocking_readers
, 0);
4802 atomic_set(&eb
->blocking_writers
, 0);
4803 atomic_set(&eb
->spinning_readers
, 0);
4804 atomic_set(&eb
->spinning_writers
, 0);
4805 eb
->lock_nested
= 0;
4806 init_waitqueue_head(&eb
->write_lock_wq
);
4807 init_waitqueue_head(&eb
->read_lock_wq
);
4809 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4811 spin_lock_init(&eb
->refs_lock
);
4812 atomic_set(&eb
->refs
, 1);
4813 atomic_set(&eb
->io_pages
, 0);
4816 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4818 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4819 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4820 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4825 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4829 struct extent_buffer
*new;
4830 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4832 new = __alloc_extent_buffer(src
->fs_info
, src
->start
, src
->len
);
4836 for (i
= 0; i
< num_pages
; i
++) {
4837 p
= alloc_page(GFP_NOFS
);
4839 btrfs_release_extent_buffer(new);
4842 attach_extent_buffer_page(new, p
);
4843 WARN_ON(PageDirty(p
));
4846 copy_page(page_address(p
), page_address(src
->pages
[i
]));
4849 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4850 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4855 struct extent_buffer
*__alloc_dummy_extent_buffer(struct btrfs_fs_info
*fs_info
,
4856 u64 start
, unsigned long len
)
4858 struct extent_buffer
*eb
;
4859 unsigned long num_pages
;
4862 num_pages
= num_extent_pages(start
, len
);
4864 eb
= __alloc_extent_buffer(fs_info
, start
, len
);
4868 for (i
= 0; i
< num_pages
; i
++) {
4869 eb
->pages
[i
] = alloc_page(GFP_NOFS
);
4873 set_extent_buffer_uptodate(eb
);
4874 btrfs_set_header_nritems(eb
, 0);
4875 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4880 __free_page(eb
->pages
[i
- 1]);
4881 __free_extent_buffer(eb
);
4885 struct extent_buffer
*alloc_dummy_extent_buffer(struct btrfs_fs_info
*fs_info
,
4888 return __alloc_dummy_extent_buffer(fs_info
, start
, fs_info
->nodesize
);
4891 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4894 /* the ref bit is tricky. We have to make sure it is set
4895 * if we have the buffer dirty. Otherwise the
4896 * code to free a buffer can end up dropping a dirty
4899 * Once the ref bit is set, it won't go away while the
4900 * buffer is dirty or in writeback, and it also won't
4901 * go away while we have the reference count on the
4904 * We can't just set the ref bit without bumping the
4905 * ref on the eb because free_extent_buffer might
4906 * see the ref bit and try to clear it. If this happens
4907 * free_extent_buffer might end up dropping our original
4908 * ref by mistake and freeing the page before we are able
4909 * to add one more ref.
4911 * So bump the ref count first, then set the bit. If someone
4912 * beat us to it, drop the ref we added.
4914 refs
= atomic_read(&eb
->refs
);
4915 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4918 spin_lock(&eb
->refs_lock
);
4919 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4920 atomic_inc(&eb
->refs
);
4921 spin_unlock(&eb
->refs_lock
);
4924 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
,
4925 struct page
*accessed
)
4927 unsigned long num_pages
, i
;
4929 check_buffer_tree_ref(eb
);
4931 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4932 for (i
= 0; i
< num_pages
; i
++) {
4933 struct page
*p
= eb
->pages
[i
];
4936 mark_page_accessed(p
);
4940 struct extent_buffer
*find_extent_buffer(struct btrfs_fs_info
*fs_info
,
4943 struct extent_buffer
*eb
;
4946 eb
= radix_tree_lookup(&fs_info
->buffer_radix
,
4947 start
>> PAGE_SHIFT
);
4948 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4951 * Lock our eb's refs_lock to avoid races with
4952 * free_extent_buffer. When we get our eb it might be flagged
4953 * with EXTENT_BUFFER_STALE and another task running
4954 * free_extent_buffer might have seen that flag set,
4955 * eb->refs == 2, that the buffer isn't under IO (dirty and
4956 * writeback flags not set) and it's still in the tree (flag
4957 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4958 * of decrementing the extent buffer's reference count twice.
4959 * So here we could race and increment the eb's reference count,
4960 * clear its stale flag, mark it as dirty and drop our reference
4961 * before the other task finishes executing free_extent_buffer,
4962 * which would later result in an attempt to free an extent
4963 * buffer that is dirty.
4965 if (test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
)) {
4966 spin_lock(&eb
->refs_lock
);
4967 spin_unlock(&eb
->refs_lock
);
4969 mark_extent_buffer_accessed(eb
, NULL
);
4977 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4978 struct extent_buffer
*alloc_test_extent_buffer(struct btrfs_fs_info
*fs_info
,
4981 struct extent_buffer
*eb
, *exists
= NULL
;
4984 eb
= find_extent_buffer(fs_info
, start
);
4987 eb
= alloc_dummy_extent_buffer(fs_info
, start
);
4990 eb
->fs_info
= fs_info
;
4992 ret
= radix_tree_preload(GFP_NOFS
);
4995 spin_lock(&fs_info
->buffer_lock
);
4996 ret
= radix_tree_insert(&fs_info
->buffer_radix
,
4997 start
>> PAGE_SHIFT
, eb
);
4998 spin_unlock(&fs_info
->buffer_lock
);
4999 radix_tree_preload_end();
5000 if (ret
== -EEXIST
) {
5001 exists
= find_extent_buffer(fs_info
, start
);
5007 check_buffer_tree_ref(eb
);
5008 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
5011 * We will free dummy extent buffer's if they come into
5012 * free_extent_buffer with a ref count of 2, but if we are using this we
5013 * want the buffers to stay in memory until we're done with them, so
5014 * bump the ref count again.
5016 atomic_inc(&eb
->refs
);
5019 btrfs_release_extent_buffer(eb
);
5024 struct extent_buffer
*alloc_extent_buffer(struct btrfs_fs_info
*fs_info
,
5027 unsigned long len
= fs_info
->nodesize
;
5028 unsigned long num_pages
= num_extent_pages(start
, len
);
5030 unsigned long index
= start
>> PAGE_SHIFT
;
5031 struct extent_buffer
*eb
;
5032 struct extent_buffer
*exists
= NULL
;
5034 struct address_space
*mapping
= fs_info
->btree_inode
->i_mapping
;
5038 if (!IS_ALIGNED(start
, fs_info
->sectorsize
)) {
5039 btrfs_err(fs_info
, "bad tree block start %llu", start
);
5040 return ERR_PTR(-EINVAL
);
5043 eb
= find_extent_buffer(fs_info
, start
);
5047 eb
= __alloc_extent_buffer(fs_info
, start
, len
);
5049 return ERR_PTR(-ENOMEM
);
5051 for (i
= 0; i
< num_pages
; i
++, index
++) {
5052 p
= find_or_create_page(mapping
, index
, GFP_NOFS
|__GFP_NOFAIL
);
5054 exists
= ERR_PTR(-ENOMEM
);
5058 spin_lock(&mapping
->private_lock
);
5059 if (PagePrivate(p
)) {
5061 * We could have already allocated an eb for this page
5062 * and attached one so lets see if we can get a ref on
5063 * the existing eb, and if we can we know it's good and
5064 * we can just return that one, else we know we can just
5065 * overwrite page->private.
5067 exists
= (struct extent_buffer
*)p
->private;
5068 if (atomic_inc_not_zero(&exists
->refs
)) {
5069 spin_unlock(&mapping
->private_lock
);
5072 mark_extent_buffer_accessed(exists
, p
);
5078 * Do this so attach doesn't complain and we need to
5079 * drop the ref the old guy had.
5081 ClearPagePrivate(p
);
5082 WARN_ON(PageDirty(p
));
5085 attach_extent_buffer_page(eb
, p
);
5086 spin_unlock(&mapping
->private_lock
);
5087 WARN_ON(PageDirty(p
));
5089 if (!PageUptodate(p
))
5093 * see below about how we avoid a nasty race with release page
5094 * and why we unlock later
5098 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5100 ret
= radix_tree_preload(GFP_NOFS
);
5102 exists
= ERR_PTR(ret
);
5106 spin_lock(&fs_info
->buffer_lock
);
5107 ret
= radix_tree_insert(&fs_info
->buffer_radix
,
5108 start
>> PAGE_SHIFT
, eb
);
5109 spin_unlock(&fs_info
->buffer_lock
);
5110 radix_tree_preload_end();
5111 if (ret
== -EEXIST
) {
5112 exists
= find_extent_buffer(fs_info
, start
);
5118 /* add one reference for the tree */
5119 check_buffer_tree_ref(eb
);
5120 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
5123 * there is a race where release page may have
5124 * tried to find this extent buffer in the radix
5125 * but failed. It will tell the VM it is safe to
5126 * reclaim the, and it will clear the page private bit.
5127 * We must make sure to set the page private bit properly
5128 * after the extent buffer is in the radix tree so
5129 * it doesn't get lost
5131 SetPageChecked(eb
->pages
[0]);
5132 for (i
= 1; i
< num_pages
; i
++) {
5134 ClearPageChecked(p
);
5137 unlock_page(eb
->pages
[0]);
5141 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
5142 for (i
= 0; i
< num_pages
; i
++) {
5144 unlock_page(eb
->pages
[i
]);
5147 btrfs_release_extent_buffer(eb
);
5151 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
5153 struct extent_buffer
*eb
=
5154 container_of(head
, struct extent_buffer
, rcu_head
);
5156 __free_extent_buffer(eb
);
5159 /* Expects to have eb->eb_lock already held */
5160 static int release_extent_buffer(struct extent_buffer
*eb
)
5162 WARN_ON(atomic_read(&eb
->refs
) == 0);
5163 if (atomic_dec_and_test(&eb
->refs
)) {
5164 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
)) {
5165 struct btrfs_fs_info
*fs_info
= eb
->fs_info
;
5167 spin_unlock(&eb
->refs_lock
);
5169 spin_lock(&fs_info
->buffer_lock
);
5170 radix_tree_delete(&fs_info
->buffer_radix
,
5171 eb
->start
>> PAGE_SHIFT
);
5172 spin_unlock(&fs_info
->buffer_lock
);
5174 spin_unlock(&eb
->refs_lock
);
5177 /* Should be safe to release our pages at this point */
5178 btrfs_release_extent_buffer_page(eb
);
5179 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5180 if (unlikely(test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))) {
5181 __free_extent_buffer(eb
);
5185 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
5188 spin_unlock(&eb
->refs_lock
);
5193 void free_extent_buffer(struct extent_buffer
*eb
)
5201 refs
= atomic_read(&eb
->refs
);
5204 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
5209 spin_lock(&eb
->refs_lock
);
5210 if (atomic_read(&eb
->refs
) == 2 &&
5211 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
5212 atomic_dec(&eb
->refs
);
5214 if (atomic_read(&eb
->refs
) == 2 &&
5215 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
5216 !extent_buffer_under_io(eb
) &&
5217 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
5218 atomic_dec(&eb
->refs
);
5221 * I know this is terrible, but it's temporary until we stop tracking
5222 * the uptodate bits and such for the extent buffers.
5224 release_extent_buffer(eb
);
5227 void free_extent_buffer_stale(struct extent_buffer
*eb
)
5232 spin_lock(&eb
->refs_lock
);
5233 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
5235 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
5236 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
5237 atomic_dec(&eb
->refs
);
5238 release_extent_buffer(eb
);
5241 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
5244 unsigned long num_pages
;
5247 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5249 for (i
= 0; i
< num_pages
; i
++) {
5250 page
= eb
->pages
[i
];
5251 if (!PageDirty(page
))
5255 WARN_ON(!PagePrivate(page
));
5257 clear_page_dirty_for_io(page
);
5258 spin_lock_irq(&page
->mapping
->tree_lock
);
5259 if (!PageDirty(page
)) {
5260 radix_tree_tag_clear(&page
->mapping
->page_tree
,
5262 PAGECACHE_TAG_DIRTY
);
5264 spin_unlock_irq(&page
->mapping
->tree_lock
);
5265 ClearPageError(page
);
5268 WARN_ON(atomic_read(&eb
->refs
) == 0);
5271 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
5274 unsigned long num_pages
;
5277 check_buffer_tree_ref(eb
);
5279 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
5281 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5282 WARN_ON(atomic_read(&eb
->refs
) == 0);
5283 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
5285 for (i
= 0; i
< num_pages
; i
++)
5286 set_page_dirty(eb
->pages
[i
]);
5290 void clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
5294 unsigned long num_pages
;
5296 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5297 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5298 for (i
= 0; i
< num_pages
; i
++) {
5299 page
= eb
->pages
[i
];
5301 ClearPageUptodate(page
);
5305 void set_extent_buffer_uptodate(struct extent_buffer
*eb
)
5309 unsigned long num_pages
;
5311 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5312 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5313 for (i
= 0; i
< num_pages
; i
++) {
5314 page
= eb
->pages
[i
];
5315 SetPageUptodate(page
);
5319 int extent_buffer_uptodate(struct extent_buffer
*eb
)
5321 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5324 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
5325 struct extent_buffer
*eb
, int wait
,
5326 get_extent_t
*get_extent
, int mirror_num
)
5332 int locked_pages
= 0;
5333 int all_uptodate
= 1;
5334 unsigned long num_pages
;
5335 unsigned long num_reads
= 0;
5336 struct bio
*bio
= NULL
;
5337 unsigned long bio_flags
= 0;
5339 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
5342 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5343 for (i
= 0; i
< num_pages
; i
++) {
5344 page
= eb
->pages
[i
];
5345 if (wait
== WAIT_NONE
) {
5346 if (!trylock_page(page
))
5354 * We need to firstly lock all pages to make sure that
5355 * the uptodate bit of our pages won't be affected by
5356 * clear_extent_buffer_uptodate().
5358 for (i
= 0; i
< num_pages
; i
++) {
5359 page
= eb
->pages
[i
];
5360 if (!PageUptodate(page
)) {
5367 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5371 clear_bit(EXTENT_BUFFER_READ_ERR
, &eb
->bflags
);
5372 eb
->read_mirror
= 0;
5373 atomic_set(&eb
->io_pages
, num_reads
);
5374 for (i
= 0; i
< num_pages
; i
++) {
5375 page
= eb
->pages
[i
];
5377 if (!PageUptodate(page
)) {
5379 atomic_dec(&eb
->io_pages
);
5384 ClearPageError(page
);
5385 err
= __extent_read_full_page(tree
, page
,
5387 mirror_num
, &bio_flags
,
5392 * We use &bio in above __extent_read_full_page,
5393 * so we ensure that if it returns error, the
5394 * current page fails to add itself to bio and
5395 * it's been unlocked.
5397 * We must dec io_pages by ourselves.
5399 atomic_dec(&eb
->io_pages
);
5407 err
= submit_one_bio(bio
, mirror_num
, bio_flags
);
5412 if (ret
|| wait
!= WAIT_COMPLETE
)
5415 for (i
= 0; i
< num_pages
; i
++) {
5416 page
= eb
->pages
[i
];
5417 wait_on_page_locked(page
);
5418 if (!PageUptodate(page
))
5425 while (locked_pages
> 0) {
5427 page
= eb
->pages
[locked_pages
];
5433 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
5434 unsigned long start
,
5441 char *dst
= (char *)dstv
;
5442 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5443 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5445 WARN_ON(start
> eb
->len
);
5446 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5448 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5451 page
= eb
->pages
[i
];
5453 cur
= min(len
, (PAGE_SIZE
- offset
));
5454 kaddr
= page_address(page
);
5455 memcpy(dst
, kaddr
+ offset
, cur
);
5464 int read_extent_buffer_to_user(struct extent_buffer
*eb
, void __user
*dstv
,
5465 unsigned long start
,
5472 char __user
*dst
= (char __user
*)dstv
;
5473 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5474 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5477 WARN_ON(start
> eb
->len
);
5478 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5480 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5483 page
= eb
->pages
[i
];
5485 cur
= min(len
, (PAGE_SIZE
- offset
));
5486 kaddr
= page_address(page
);
5487 if (copy_to_user(dst
, kaddr
+ offset
, cur
)) {
5502 * return 0 if the item is found within a page.
5503 * return 1 if the item spans two pages.
5504 * return -EINVAL otherwise.
5506 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
5507 unsigned long min_len
, char **map
,
5508 unsigned long *map_start
,
5509 unsigned long *map_len
)
5511 size_t offset
= start
& (PAGE_SIZE
- 1);
5514 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5515 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5516 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
5523 offset
= start_offset
;
5527 *map_start
= ((u64
)i
<< PAGE_SHIFT
) - start_offset
;
5530 if (start
+ min_len
> eb
->len
) {
5531 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5532 eb
->start
, eb
->len
, start
, min_len
);
5537 kaddr
= page_address(p
);
5538 *map
= kaddr
+ offset
;
5539 *map_len
= PAGE_SIZE
- offset
;
5543 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
5544 unsigned long start
,
5551 char *ptr
= (char *)ptrv
;
5552 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5553 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5556 WARN_ON(start
> eb
->len
);
5557 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5559 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5562 page
= eb
->pages
[i
];
5564 cur
= min(len
, (PAGE_SIZE
- offset
));
5566 kaddr
= page_address(page
);
5567 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
5579 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer
*eb
,
5584 WARN_ON(!PageUptodate(eb
->pages
[0]));
5585 kaddr
= page_address(eb
->pages
[0]);
5586 memcpy(kaddr
+ offsetof(struct btrfs_header
, chunk_tree_uuid
), srcv
,
5590 void write_extent_buffer_fsid(struct extent_buffer
*eb
, const void *srcv
)
5594 WARN_ON(!PageUptodate(eb
->pages
[0]));
5595 kaddr
= page_address(eb
->pages
[0]);
5596 memcpy(kaddr
+ offsetof(struct btrfs_header
, fsid
), srcv
,
5600 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
5601 unsigned long start
, unsigned long len
)
5607 char *src
= (char *)srcv
;
5608 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5609 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5611 WARN_ON(start
> eb
->len
);
5612 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5614 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5617 page
= eb
->pages
[i
];
5618 WARN_ON(!PageUptodate(page
));
5620 cur
= min(len
, PAGE_SIZE
- offset
);
5621 kaddr
= page_address(page
);
5622 memcpy(kaddr
+ offset
, src
, cur
);
5631 void memzero_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
5638 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5639 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5641 WARN_ON(start
> eb
->len
);
5642 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5644 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5647 page
= eb
->pages
[i
];
5648 WARN_ON(!PageUptodate(page
));
5650 cur
= min(len
, PAGE_SIZE
- offset
);
5651 kaddr
= page_address(page
);
5652 memset(kaddr
+ offset
, 0, cur
);
5660 void copy_extent_buffer_full(struct extent_buffer
*dst
,
5661 struct extent_buffer
*src
)
5666 ASSERT(dst
->len
== src
->len
);
5668 num_pages
= num_extent_pages(dst
->start
, dst
->len
);
5669 for (i
= 0; i
< num_pages
; i
++)
5670 copy_page(page_address(dst
->pages
[i
]),
5671 page_address(src
->pages
[i
]));
5674 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
5675 unsigned long dst_offset
, unsigned long src_offset
,
5678 u64 dst_len
= dst
->len
;
5683 size_t start_offset
= dst
->start
& ((u64
)PAGE_SIZE
- 1);
5684 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_SHIFT
;
5686 WARN_ON(src
->len
!= dst_len
);
5688 offset
= (start_offset
+ dst_offset
) &
5692 page
= dst
->pages
[i
];
5693 WARN_ON(!PageUptodate(page
));
5695 cur
= min(len
, (unsigned long)(PAGE_SIZE
- offset
));
5697 kaddr
= page_address(page
);
5698 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
5707 void le_bitmap_set(u8
*map
, unsigned int start
, int len
)
5709 u8
*p
= map
+ BIT_BYTE(start
);
5710 const unsigned int size
= start
+ len
;
5711 int bits_to_set
= BITS_PER_BYTE
- (start
% BITS_PER_BYTE
);
5712 u8 mask_to_set
= BITMAP_FIRST_BYTE_MASK(start
);
5714 while (len
- bits_to_set
>= 0) {
5717 bits_to_set
= BITS_PER_BYTE
;
5722 mask_to_set
&= BITMAP_LAST_BYTE_MASK(size
);
5727 void le_bitmap_clear(u8
*map
, unsigned int start
, int len
)
5729 u8
*p
= map
+ BIT_BYTE(start
);
5730 const unsigned int size
= start
+ len
;
5731 int bits_to_clear
= BITS_PER_BYTE
- (start
% BITS_PER_BYTE
);
5732 u8 mask_to_clear
= BITMAP_FIRST_BYTE_MASK(start
);
5734 while (len
- bits_to_clear
>= 0) {
5735 *p
&= ~mask_to_clear
;
5736 len
-= bits_to_clear
;
5737 bits_to_clear
= BITS_PER_BYTE
;
5742 mask_to_clear
&= BITMAP_LAST_BYTE_MASK(size
);
5743 *p
&= ~mask_to_clear
;
5748 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5750 * @eb: the extent buffer
5751 * @start: offset of the bitmap item in the extent buffer
5753 * @page_index: return index of the page in the extent buffer that contains the
5755 * @page_offset: return offset into the page given by page_index
5757 * This helper hides the ugliness of finding the byte in an extent buffer which
5758 * contains a given bit.
5760 static inline void eb_bitmap_offset(struct extent_buffer
*eb
,
5761 unsigned long start
, unsigned long nr
,
5762 unsigned long *page_index
,
5763 size_t *page_offset
)
5765 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5766 size_t byte_offset
= BIT_BYTE(nr
);
5770 * The byte we want is the offset of the extent buffer + the offset of
5771 * the bitmap item in the extent buffer + the offset of the byte in the
5774 offset
= start_offset
+ start
+ byte_offset
;
5776 *page_index
= offset
>> PAGE_SHIFT
;
5777 *page_offset
= offset
& (PAGE_SIZE
- 1);
5781 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5782 * @eb: the extent buffer
5783 * @start: offset of the bitmap item in the extent buffer
5784 * @nr: bit number to test
5786 int extent_buffer_test_bit(struct extent_buffer
*eb
, unsigned long start
,
5794 eb_bitmap_offset(eb
, start
, nr
, &i
, &offset
);
5795 page
= eb
->pages
[i
];
5796 WARN_ON(!PageUptodate(page
));
5797 kaddr
= page_address(page
);
5798 return 1U & (kaddr
[offset
] >> (nr
& (BITS_PER_BYTE
- 1)));
5802 * extent_buffer_bitmap_set - set an area of a bitmap
5803 * @eb: the extent buffer
5804 * @start: offset of the bitmap item in the extent buffer
5805 * @pos: bit number of the first bit
5806 * @len: number of bits to set
5808 void extent_buffer_bitmap_set(struct extent_buffer
*eb
, unsigned long start
,
5809 unsigned long pos
, unsigned long len
)
5815 const unsigned int size
= pos
+ len
;
5816 int bits_to_set
= BITS_PER_BYTE
- (pos
% BITS_PER_BYTE
);
5817 u8 mask_to_set
= BITMAP_FIRST_BYTE_MASK(pos
);
5819 eb_bitmap_offset(eb
, start
, pos
, &i
, &offset
);
5820 page
= eb
->pages
[i
];
5821 WARN_ON(!PageUptodate(page
));
5822 kaddr
= page_address(page
);
5824 while (len
>= bits_to_set
) {
5825 kaddr
[offset
] |= mask_to_set
;
5827 bits_to_set
= BITS_PER_BYTE
;
5829 if (++offset
>= PAGE_SIZE
&& len
> 0) {
5831 page
= eb
->pages
[++i
];
5832 WARN_ON(!PageUptodate(page
));
5833 kaddr
= page_address(page
);
5837 mask_to_set
&= BITMAP_LAST_BYTE_MASK(size
);
5838 kaddr
[offset
] |= mask_to_set
;
5844 * extent_buffer_bitmap_clear - clear an area of a bitmap
5845 * @eb: the extent buffer
5846 * @start: offset of the bitmap item in the extent buffer
5847 * @pos: bit number of the first bit
5848 * @len: number of bits to clear
5850 void extent_buffer_bitmap_clear(struct extent_buffer
*eb
, unsigned long start
,
5851 unsigned long pos
, unsigned long len
)
5857 const unsigned int size
= pos
+ len
;
5858 int bits_to_clear
= BITS_PER_BYTE
- (pos
% BITS_PER_BYTE
);
5859 u8 mask_to_clear
= BITMAP_FIRST_BYTE_MASK(pos
);
5861 eb_bitmap_offset(eb
, start
, pos
, &i
, &offset
);
5862 page
= eb
->pages
[i
];
5863 WARN_ON(!PageUptodate(page
));
5864 kaddr
= page_address(page
);
5866 while (len
>= bits_to_clear
) {
5867 kaddr
[offset
] &= ~mask_to_clear
;
5868 len
-= bits_to_clear
;
5869 bits_to_clear
= BITS_PER_BYTE
;
5871 if (++offset
>= PAGE_SIZE
&& len
> 0) {
5873 page
= eb
->pages
[++i
];
5874 WARN_ON(!PageUptodate(page
));
5875 kaddr
= page_address(page
);
5879 mask_to_clear
&= BITMAP_LAST_BYTE_MASK(size
);
5880 kaddr
[offset
] &= ~mask_to_clear
;
5884 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
5886 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
5887 return distance
< len
;
5890 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
5891 unsigned long dst_off
, unsigned long src_off
,
5894 char *dst_kaddr
= page_address(dst_page
);
5896 int must_memmove
= 0;
5898 if (dst_page
!= src_page
) {
5899 src_kaddr
= page_address(src_page
);
5901 src_kaddr
= dst_kaddr
;
5902 if (areas_overlap(src_off
, dst_off
, len
))
5907 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5909 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5912 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5913 unsigned long src_offset
, unsigned long len
)
5915 struct btrfs_fs_info
*fs_info
= dst
->fs_info
;
5917 size_t dst_off_in_page
;
5918 size_t src_off_in_page
;
5919 size_t start_offset
= dst
->start
& ((u64
)PAGE_SIZE
- 1);
5920 unsigned long dst_i
;
5921 unsigned long src_i
;
5923 if (src_offset
+ len
> dst
->len
) {
5925 "memmove bogus src_offset %lu move len %lu dst len %lu",
5926 src_offset
, len
, dst
->len
);
5929 if (dst_offset
+ len
> dst
->len
) {
5931 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5932 dst_offset
, len
, dst
->len
);
5937 dst_off_in_page
= (start_offset
+ dst_offset
) &
5939 src_off_in_page
= (start_offset
+ src_offset
) &
5942 dst_i
= (start_offset
+ dst_offset
) >> PAGE_SHIFT
;
5943 src_i
= (start_offset
+ src_offset
) >> PAGE_SHIFT
;
5945 cur
= min(len
, (unsigned long)(PAGE_SIZE
-
5947 cur
= min_t(unsigned long, cur
,
5948 (unsigned long)(PAGE_SIZE
- dst_off_in_page
));
5950 copy_pages(dst
->pages
[dst_i
], dst
->pages
[src_i
],
5951 dst_off_in_page
, src_off_in_page
, cur
);
5959 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5960 unsigned long src_offset
, unsigned long len
)
5962 struct btrfs_fs_info
*fs_info
= dst
->fs_info
;
5964 size_t dst_off_in_page
;
5965 size_t src_off_in_page
;
5966 unsigned long dst_end
= dst_offset
+ len
- 1;
5967 unsigned long src_end
= src_offset
+ len
- 1;
5968 size_t start_offset
= dst
->start
& ((u64
)PAGE_SIZE
- 1);
5969 unsigned long dst_i
;
5970 unsigned long src_i
;
5972 if (src_offset
+ len
> dst
->len
) {
5974 "memmove bogus src_offset %lu move len %lu len %lu",
5975 src_offset
, len
, dst
->len
);
5978 if (dst_offset
+ len
> dst
->len
) {
5980 "memmove bogus dst_offset %lu move len %lu len %lu",
5981 dst_offset
, len
, dst
->len
);
5984 if (dst_offset
< src_offset
) {
5985 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5989 dst_i
= (start_offset
+ dst_end
) >> PAGE_SHIFT
;
5990 src_i
= (start_offset
+ src_end
) >> PAGE_SHIFT
;
5992 dst_off_in_page
= (start_offset
+ dst_end
) &
5994 src_off_in_page
= (start_offset
+ src_end
) &
5997 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5998 cur
= min(cur
, dst_off_in_page
+ 1);
5999 copy_pages(dst
->pages
[dst_i
], dst
->pages
[src_i
],
6000 dst_off_in_page
- cur
+ 1,
6001 src_off_in_page
- cur
+ 1, cur
);
6009 int try_release_extent_buffer(struct page
*page
)
6011 struct extent_buffer
*eb
;
6014 * We need to make sure nobody is attaching this page to an eb right
6017 spin_lock(&page
->mapping
->private_lock
);
6018 if (!PagePrivate(page
)) {
6019 spin_unlock(&page
->mapping
->private_lock
);
6023 eb
= (struct extent_buffer
*)page
->private;
6027 * This is a little awful but should be ok, we need to make sure that
6028 * the eb doesn't disappear out from under us while we're looking at
6031 spin_lock(&eb
->refs_lock
);
6032 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
6033 spin_unlock(&eb
->refs_lock
);
6034 spin_unlock(&page
->mapping
->private_lock
);
6037 spin_unlock(&page
->mapping
->private_lock
);
6040 * If tree ref isn't set then we know the ref on this eb is a real ref,
6041 * so just return, this page will likely be freed soon anyway.
6043 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
6044 spin_unlock(&eb
->refs_lock
);
6048 return release_extent_buffer(eb
);