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
)
90 if (tree
->ops
&& tree
->ops
->check_extent_io_range
)
91 tree
->ops
->check_extent_io_range(tree
->private_data
, caller
,
95 #define btrfs_leak_debug_add(new, head) do {} while (0)
96 #define btrfs_leak_debug_del(entry) do {} while (0)
97 #define btrfs_leak_debug_check() do {} while (0)
98 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
101 #define BUFFER_LRU_MAX 64
106 struct rb_node rb_node
;
109 struct extent_page_data
{
111 struct extent_io_tree
*tree
;
112 get_extent_t
*get_extent
;
113 unsigned long bio_flags
;
115 /* tells writepage not to lock the state bits for this range
116 * it still does the unlocking
118 unsigned int extent_locked
:1;
120 /* tells the submit_bio code to use REQ_SYNC */
121 unsigned int sync_io
:1;
124 static void add_extent_changeset(struct extent_state
*state
, unsigned bits
,
125 struct extent_changeset
*changeset
,
132 if (set
&& (state
->state
& bits
) == bits
)
134 if (!set
&& (state
->state
& bits
) == 0)
136 changeset
->bytes_changed
+= state
->end
- state
->start
+ 1;
137 ret
= ulist_add(&changeset
->range_changed
, state
->start
, state
->end
,
143 static noinline
void flush_write_bio(void *data
);
144 static inline struct btrfs_fs_info
*
145 tree_fs_info(struct extent_io_tree
*tree
)
148 return tree
->ops
->tree_fs_info(tree
->private_data
);
152 int __init
extent_io_init(void)
154 extent_state_cache
= kmem_cache_create("btrfs_extent_state",
155 sizeof(struct extent_state
), 0,
156 SLAB_MEM_SPREAD
, NULL
);
157 if (!extent_state_cache
)
160 extent_buffer_cache
= kmem_cache_create("btrfs_extent_buffer",
161 sizeof(struct extent_buffer
), 0,
162 SLAB_MEM_SPREAD
, NULL
);
163 if (!extent_buffer_cache
)
164 goto free_state_cache
;
166 btrfs_bioset
= bioset_create(BIO_POOL_SIZE
,
167 offsetof(struct btrfs_io_bio
, bio
));
169 goto free_buffer_cache
;
171 if (bioset_integrity_create(btrfs_bioset
, BIO_POOL_SIZE
))
177 bioset_free(btrfs_bioset
);
181 kmem_cache_destroy(extent_buffer_cache
);
182 extent_buffer_cache
= NULL
;
185 kmem_cache_destroy(extent_state_cache
);
186 extent_state_cache
= NULL
;
190 void extent_io_exit(void)
192 btrfs_leak_debug_check();
195 * Make sure all delayed rcu free are flushed before we
199 kmem_cache_destroy(extent_state_cache
);
200 kmem_cache_destroy(extent_buffer_cache
);
202 bioset_free(btrfs_bioset
);
205 void extent_io_tree_init(struct extent_io_tree
*tree
,
208 tree
->state
= RB_ROOT
;
210 tree
->dirty_bytes
= 0;
211 spin_lock_init(&tree
->lock
);
212 tree
->private_data
= private_data
;
215 static struct extent_state
*alloc_extent_state(gfp_t mask
)
217 struct extent_state
*state
;
220 * The given mask might be not appropriate for the slab allocator,
221 * drop the unsupported bits
223 mask
&= ~(__GFP_DMA32
|__GFP_HIGHMEM
);
224 state
= kmem_cache_alloc(extent_state_cache
, mask
);
228 state
->failrec
= NULL
;
229 RB_CLEAR_NODE(&state
->rb_node
);
230 btrfs_leak_debug_add(&state
->leak_list
, &states
);
231 refcount_set(&state
->refs
, 1);
232 init_waitqueue_head(&state
->wq
);
233 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
237 void free_extent_state(struct extent_state
*state
)
241 if (refcount_dec_and_test(&state
->refs
)) {
242 WARN_ON(extent_state_in_tree(state
));
243 btrfs_leak_debug_del(&state
->leak_list
);
244 trace_free_extent_state(state
, _RET_IP_
);
245 kmem_cache_free(extent_state_cache
, state
);
249 static struct rb_node
*tree_insert(struct rb_root
*root
,
250 struct rb_node
*search_start
,
252 struct rb_node
*node
,
253 struct rb_node
***p_in
,
254 struct rb_node
**parent_in
)
257 struct rb_node
*parent
= NULL
;
258 struct tree_entry
*entry
;
260 if (p_in
&& parent_in
) {
266 p
= search_start
? &search_start
: &root
->rb_node
;
269 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
271 if (offset
< entry
->start
)
273 else if (offset
> entry
->end
)
280 rb_link_node(node
, parent
, p
);
281 rb_insert_color(node
, root
);
285 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
286 struct rb_node
**prev_ret
,
287 struct rb_node
**next_ret
,
288 struct rb_node
***p_ret
,
289 struct rb_node
**parent_ret
)
291 struct rb_root
*root
= &tree
->state
;
292 struct rb_node
**n
= &root
->rb_node
;
293 struct rb_node
*prev
= NULL
;
294 struct rb_node
*orig_prev
= NULL
;
295 struct tree_entry
*entry
;
296 struct tree_entry
*prev_entry
= NULL
;
300 entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
303 if (offset
< entry
->start
)
305 else if (offset
> entry
->end
)
318 while (prev
&& offset
> prev_entry
->end
) {
319 prev
= rb_next(prev
);
320 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
327 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
328 while (prev
&& offset
< prev_entry
->start
) {
329 prev
= rb_prev(prev
);
330 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
337 static inline struct rb_node
*
338 tree_search_for_insert(struct extent_io_tree
*tree
,
340 struct rb_node
***p_ret
,
341 struct rb_node
**parent_ret
)
343 struct rb_node
*prev
= NULL
;
346 ret
= __etree_search(tree
, offset
, &prev
, NULL
, p_ret
, parent_ret
);
352 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
355 return tree_search_for_insert(tree
, offset
, NULL
, NULL
);
358 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
359 struct extent_state
*other
)
361 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
362 tree
->ops
->merge_extent_hook(tree
->private_data
, new, other
);
366 * utility function to look for merge candidates inside a given range.
367 * Any extents with matching state are merged together into a single
368 * extent in the tree. Extents with EXTENT_IO in their state field
369 * are not merged because the end_io handlers need to be able to do
370 * operations on them without sleeping (or doing allocations/splits).
372 * This should be called with the tree lock held.
374 static void merge_state(struct extent_io_tree
*tree
,
375 struct extent_state
*state
)
377 struct extent_state
*other
;
378 struct rb_node
*other_node
;
380 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
383 other_node
= rb_prev(&state
->rb_node
);
385 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
386 if (other
->end
== state
->start
- 1 &&
387 other
->state
== state
->state
) {
388 merge_cb(tree
, state
, other
);
389 state
->start
= other
->start
;
390 rb_erase(&other
->rb_node
, &tree
->state
);
391 RB_CLEAR_NODE(&other
->rb_node
);
392 free_extent_state(other
);
395 other_node
= rb_next(&state
->rb_node
);
397 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
398 if (other
->start
== state
->end
+ 1 &&
399 other
->state
== state
->state
) {
400 merge_cb(tree
, state
, other
);
401 state
->end
= other
->end
;
402 rb_erase(&other
->rb_node
, &tree
->state
);
403 RB_CLEAR_NODE(&other
->rb_node
);
404 free_extent_state(other
);
409 static void set_state_cb(struct extent_io_tree
*tree
,
410 struct extent_state
*state
, unsigned *bits
)
412 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
413 tree
->ops
->set_bit_hook(tree
->private_data
, state
, bits
);
416 static void clear_state_cb(struct extent_io_tree
*tree
,
417 struct extent_state
*state
, unsigned *bits
)
419 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
420 tree
->ops
->clear_bit_hook(tree
->private_data
, state
, bits
);
423 static void set_state_bits(struct extent_io_tree
*tree
,
424 struct extent_state
*state
, unsigned *bits
,
425 struct extent_changeset
*changeset
);
428 * insert an extent_state struct into the tree. 'bits' are set on the
429 * struct before it is inserted.
431 * This may return -EEXIST if the extent is already there, in which case the
432 * state struct is freed.
434 * The tree lock is not taken internally. This is a utility function and
435 * probably isn't what you want to call (see set/clear_extent_bit).
437 static int insert_state(struct extent_io_tree
*tree
,
438 struct extent_state
*state
, u64 start
, u64 end
,
440 struct rb_node
**parent
,
441 unsigned *bits
, struct extent_changeset
*changeset
)
443 struct rb_node
*node
;
446 WARN(1, KERN_ERR
"BTRFS: end < start %llu %llu\n",
448 state
->start
= start
;
451 set_state_bits(tree
, state
, bits
, changeset
);
453 node
= tree_insert(&tree
->state
, NULL
, end
, &state
->rb_node
, p
, parent
);
455 struct extent_state
*found
;
456 found
= rb_entry(node
, struct extent_state
, rb_node
);
457 pr_err("BTRFS: found node %llu %llu on insert of %llu %llu\n",
458 found
->start
, found
->end
, start
, end
);
461 merge_state(tree
, state
);
465 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
468 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
469 tree
->ops
->split_extent_hook(tree
->private_data
, orig
, split
);
473 * split a given extent state struct in two, inserting the preallocated
474 * struct 'prealloc' as the newly created second half. 'split' indicates an
475 * offset inside 'orig' where it should be split.
478 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
479 * are two extent state structs in the tree:
480 * prealloc: [orig->start, split - 1]
481 * orig: [ split, orig->end ]
483 * The tree locks are not taken by this function. They need to be held
486 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
487 struct extent_state
*prealloc
, u64 split
)
489 struct rb_node
*node
;
491 split_cb(tree
, orig
, split
);
493 prealloc
->start
= orig
->start
;
494 prealloc
->end
= split
- 1;
495 prealloc
->state
= orig
->state
;
498 node
= tree_insert(&tree
->state
, &orig
->rb_node
, prealloc
->end
,
499 &prealloc
->rb_node
, NULL
, NULL
);
501 free_extent_state(prealloc
);
507 static struct extent_state
*next_state(struct extent_state
*state
)
509 struct rb_node
*next
= rb_next(&state
->rb_node
);
511 return rb_entry(next
, struct extent_state
, rb_node
);
517 * utility function to clear some bits in an extent state struct.
518 * it will optionally wake up any one waiting on this state (wake == 1).
520 * If no bits are set on the state struct after clearing things, the
521 * struct is freed and removed from the tree
523 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
524 struct extent_state
*state
,
525 unsigned *bits
, int wake
,
526 struct extent_changeset
*changeset
)
528 struct extent_state
*next
;
529 unsigned bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
531 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
532 u64 range
= state
->end
- state
->start
+ 1;
533 WARN_ON(range
> tree
->dirty_bytes
);
534 tree
->dirty_bytes
-= range
;
536 clear_state_cb(tree
, state
, bits
);
537 add_extent_changeset(state
, bits_to_clear
, changeset
, 0);
538 state
->state
&= ~bits_to_clear
;
541 if (state
->state
== 0) {
542 next
= next_state(state
);
543 if (extent_state_in_tree(state
)) {
544 rb_erase(&state
->rb_node
, &tree
->state
);
545 RB_CLEAR_NODE(&state
->rb_node
);
546 free_extent_state(state
);
551 merge_state(tree
, state
);
552 next
= next_state(state
);
557 static struct extent_state
*
558 alloc_extent_state_atomic(struct extent_state
*prealloc
)
561 prealloc
= alloc_extent_state(GFP_ATOMIC
);
566 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
568 btrfs_panic(tree_fs_info(tree
), err
,
569 "Locking error: Extent tree was modified by another thread while locked.");
573 * clear some bits on a range in the tree. This may require splitting
574 * or inserting elements in the tree, so the gfp mask is used to
575 * indicate which allocations or sleeping are allowed.
577 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
578 * the given range from the tree regardless of state (ie for truncate).
580 * the range [start, end] is inclusive.
582 * This takes the tree lock, and returns 0 on success and < 0 on error.
584 static int __clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
585 unsigned bits
, int wake
, int delete,
586 struct extent_state
**cached_state
,
587 gfp_t mask
, struct extent_changeset
*changeset
)
589 struct extent_state
*state
;
590 struct extent_state
*cached
;
591 struct extent_state
*prealloc
= NULL
;
592 struct rb_node
*node
;
597 btrfs_debug_check_extent_io_range(tree
, start
, end
);
599 if (bits
& EXTENT_DELALLOC
)
600 bits
|= EXTENT_NORESERVE
;
603 bits
|= ~EXTENT_CTLBITS
;
604 bits
|= EXTENT_FIRST_DELALLOC
;
606 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
609 if (!prealloc
&& gfpflags_allow_blocking(mask
)) {
611 * Don't care for allocation failure here because we might end
612 * up not needing the pre-allocated extent state at all, which
613 * is the case if we only have in the tree extent states that
614 * cover our input range and don't cover too any other range.
615 * If we end up needing a new extent state we allocate it later.
617 prealloc
= alloc_extent_state(mask
);
620 spin_lock(&tree
->lock
);
622 cached
= *cached_state
;
625 *cached_state
= NULL
;
629 if (cached
&& extent_state_in_tree(cached
) &&
630 cached
->start
<= start
&& cached
->end
> start
) {
632 refcount_dec(&cached
->refs
);
637 free_extent_state(cached
);
640 * this search will find the extents that end after
643 node
= tree_search(tree
, start
);
646 state
= rb_entry(node
, struct extent_state
, rb_node
);
648 if (state
->start
> end
)
650 WARN_ON(state
->end
< start
);
651 last_end
= state
->end
;
653 /* the state doesn't have the wanted bits, go ahead */
654 if (!(state
->state
& bits
)) {
655 state
= next_state(state
);
660 * | ---- desired range ---- |
662 * | ------------- state -------------- |
664 * We need to split the extent we found, and may flip
665 * bits on second half.
667 * If the extent we found extends past our range, we
668 * just split and search again. It'll get split again
669 * the next time though.
671 * If the extent we found is inside our range, we clear
672 * the desired bit on it.
675 if (state
->start
< start
) {
676 prealloc
= alloc_extent_state_atomic(prealloc
);
678 err
= split_state(tree
, state
, prealloc
, start
);
680 extent_io_tree_panic(tree
, err
);
685 if (state
->end
<= end
) {
686 state
= clear_state_bit(tree
, state
, &bits
, wake
,
693 * | ---- desired range ---- |
695 * We need to split the extent, and clear the bit
698 if (state
->start
<= end
&& state
->end
> end
) {
699 prealloc
= alloc_extent_state_atomic(prealloc
);
701 err
= split_state(tree
, state
, prealloc
, end
+ 1);
703 extent_io_tree_panic(tree
, err
);
708 clear_state_bit(tree
, prealloc
, &bits
, wake
, changeset
);
714 state
= clear_state_bit(tree
, state
, &bits
, wake
, changeset
);
716 if (last_end
== (u64
)-1)
718 start
= last_end
+ 1;
719 if (start
<= end
&& state
&& !need_resched())
725 spin_unlock(&tree
->lock
);
726 if (gfpflags_allow_blocking(mask
))
731 spin_unlock(&tree
->lock
);
733 free_extent_state(prealloc
);
739 static void wait_on_state(struct extent_io_tree
*tree
,
740 struct extent_state
*state
)
741 __releases(tree
->lock
)
742 __acquires(tree
->lock
)
745 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
746 spin_unlock(&tree
->lock
);
748 spin_lock(&tree
->lock
);
749 finish_wait(&state
->wq
, &wait
);
753 * waits for one or more bits to clear on a range in the state tree.
754 * The range [start, end] is inclusive.
755 * The tree lock is taken by this function
757 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
760 struct extent_state
*state
;
761 struct rb_node
*node
;
763 btrfs_debug_check_extent_io_range(tree
, start
, end
);
765 spin_lock(&tree
->lock
);
769 * this search will find all the extents that end after
772 node
= tree_search(tree
, start
);
777 state
= rb_entry(node
, struct extent_state
, rb_node
);
779 if (state
->start
> end
)
782 if (state
->state
& bits
) {
783 start
= state
->start
;
784 refcount_inc(&state
->refs
);
785 wait_on_state(tree
, state
);
786 free_extent_state(state
);
789 start
= state
->end
+ 1;
794 if (!cond_resched_lock(&tree
->lock
)) {
795 node
= rb_next(node
);
800 spin_unlock(&tree
->lock
);
803 static void set_state_bits(struct extent_io_tree
*tree
,
804 struct extent_state
*state
,
805 unsigned *bits
, struct extent_changeset
*changeset
)
807 unsigned bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
809 set_state_cb(tree
, state
, bits
);
810 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
811 u64 range
= state
->end
- state
->start
+ 1;
812 tree
->dirty_bytes
+= range
;
814 add_extent_changeset(state
, bits_to_set
, changeset
, 1);
815 state
->state
|= bits_to_set
;
818 static void cache_state_if_flags(struct extent_state
*state
,
819 struct extent_state
**cached_ptr
,
822 if (cached_ptr
&& !(*cached_ptr
)) {
823 if (!flags
|| (state
->state
& flags
)) {
825 refcount_inc(&state
->refs
);
830 static void cache_state(struct extent_state
*state
,
831 struct extent_state
**cached_ptr
)
833 return cache_state_if_flags(state
, cached_ptr
,
834 EXTENT_IOBITS
| EXTENT_BOUNDARY
);
838 * set some bits on a range in the tree. This may require allocations or
839 * sleeping, so the gfp mask is used to indicate what is allowed.
841 * If any of the exclusive bits are set, this will fail with -EEXIST if some
842 * part of the range already has the desired bits set. The start of the
843 * existing range is returned in failed_start in this case.
845 * [start, end] is inclusive This takes the tree lock.
848 static int __must_check
849 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
850 unsigned bits
, unsigned exclusive_bits
,
851 u64
*failed_start
, struct extent_state
**cached_state
,
852 gfp_t mask
, struct extent_changeset
*changeset
)
854 struct extent_state
*state
;
855 struct extent_state
*prealloc
= NULL
;
856 struct rb_node
*node
;
858 struct rb_node
*parent
;
863 btrfs_debug_check_extent_io_range(tree
, start
, end
);
865 bits
|= EXTENT_FIRST_DELALLOC
;
867 if (!prealloc
&& gfpflags_allow_blocking(mask
)) {
869 * Don't care for allocation failure here because we might end
870 * up not needing the pre-allocated extent state at all, which
871 * is the case if we only have in the tree extent states that
872 * cover our input range and don't cover too any other range.
873 * If we end up needing a new extent state we allocate it later.
875 prealloc
= alloc_extent_state(mask
);
878 spin_lock(&tree
->lock
);
879 if (cached_state
&& *cached_state
) {
880 state
= *cached_state
;
881 if (state
->start
<= start
&& state
->end
> start
&&
882 extent_state_in_tree(state
)) {
883 node
= &state
->rb_node
;
888 * this search will find all the extents that end after
891 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
893 prealloc
= alloc_extent_state_atomic(prealloc
);
895 err
= insert_state(tree
, prealloc
, start
, end
,
896 &p
, &parent
, &bits
, changeset
);
898 extent_io_tree_panic(tree
, err
);
900 cache_state(prealloc
, cached_state
);
904 state
= rb_entry(node
, struct extent_state
, rb_node
);
906 last_start
= state
->start
;
907 last_end
= state
->end
;
910 * | ---- desired range ---- |
913 * Just lock what we found and keep going
915 if (state
->start
== start
&& state
->end
<= end
) {
916 if (state
->state
& exclusive_bits
) {
917 *failed_start
= state
->start
;
922 set_state_bits(tree
, state
, &bits
, changeset
);
923 cache_state(state
, cached_state
);
924 merge_state(tree
, state
);
925 if (last_end
== (u64
)-1)
927 start
= last_end
+ 1;
928 state
= next_state(state
);
929 if (start
< end
&& state
&& state
->start
== start
&&
936 * | ---- desired range ---- |
939 * | ------------- state -------------- |
941 * We need to split the extent we found, and may flip bits on
944 * If the extent we found extends past our
945 * range, we just split and search again. It'll get split
946 * again the next time though.
948 * If the extent we found is inside our range, we set the
951 if (state
->start
< start
) {
952 if (state
->state
& exclusive_bits
) {
953 *failed_start
= start
;
958 prealloc
= alloc_extent_state_atomic(prealloc
);
960 err
= split_state(tree
, state
, prealloc
, start
);
962 extent_io_tree_panic(tree
, err
);
967 if (state
->end
<= end
) {
968 set_state_bits(tree
, state
, &bits
, changeset
);
969 cache_state(state
, cached_state
);
970 merge_state(tree
, state
);
971 if (last_end
== (u64
)-1)
973 start
= last_end
+ 1;
974 state
= next_state(state
);
975 if (start
< end
&& state
&& state
->start
== start
&&
982 * | ---- desired range ---- |
983 * | state | or | state |
985 * There's a hole, we need to insert something in it and
986 * ignore the extent we found.
988 if (state
->start
> start
) {
990 if (end
< last_start
)
993 this_end
= last_start
- 1;
995 prealloc
= alloc_extent_state_atomic(prealloc
);
999 * Avoid to free 'prealloc' if it can be merged with
1002 err
= insert_state(tree
, prealloc
, start
, this_end
,
1003 NULL
, NULL
, &bits
, changeset
);
1005 extent_io_tree_panic(tree
, err
);
1007 cache_state(prealloc
, cached_state
);
1009 start
= this_end
+ 1;
1013 * | ---- desired range ---- |
1015 * We need to split the extent, and set the bit
1018 if (state
->start
<= end
&& state
->end
> end
) {
1019 if (state
->state
& exclusive_bits
) {
1020 *failed_start
= start
;
1025 prealloc
= alloc_extent_state_atomic(prealloc
);
1027 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1029 extent_io_tree_panic(tree
, err
);
1031 set_state_bits(tree
, prealloc
, &bits
, changeset
);
1032 cache_state(prealloc
, cached_state
);
1033 merge_state(tree
, prealloc
);
1041 spin_unlock(&tree
->lock
);
1042 if (gfpflags_allow_blocking(mask
))
1047 spin_unlock(&tree
->lock
);
1049 free_extent_state(prealloc
);
1055 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1056 unsigned bits
, u64
* failed_start
,
1057 struct extent_state
**cached_state
, gfp_t mask
)
1059 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
1060 cached_state
, mask
, NULL
);
1065 * convert_extent_bit - convert all bits in a given range from one bit to
1067 * @tree: the io tree to search
1068 * @start: the start offset in bytes
1069 * @end: the end offset in bytes (inclusive)
1070 * @bits: the bits to set in this range
1071 * @clear_bits: the bits to clear in this range
1072 * @cached_state: state that we're going to cache
1074 * This will go through and set bits for the given range. If any states exist
1075 * already in this range they are set with the given bit and cleared of the
1076 * clear_bits. This is only meant to be used by things that are mergeable, ie
1077 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1078 * boundary bits like LOCK.
1080 * All allocations are done with GFP_NOFS.
1082 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1083 unsigned bits
, unsigned clear_bits
,
1084 struct extent_state
**cached_state
)
1086 struct extent_state
*state
;
1087 struct extent_state
*prealloc
= NULL
;
1088 struct rb_node
*node
;
1090 struct rb_node
*parent
;
1094 bool first_iteration
= true;
1096 btrfs_debug_check_extent_io_range(tree
, start
, end
);
1101 * Best effort, don't worry if extent state allocation fails
1102 * here for the first iteration. We might have a cached state
1103 * that matches exactly the target range, in which case no
1104 * extent state allocations are needed. We'll only know this
1105 * after locking the tree.
1107 prealloc
= alloc_extent_state(GFP_NOFS
);
1108 if (!prealloc
&& !first_iteration
)
1112 spin_lock(&tree
->lock
);
1113 if (cached_state
&& *cached_state
) {
1114 state
= *cached_state
;
1115 if (state
->start
<= start
&& state
->end
> start
&&
1116 extent_state_in_tree(state
)) {
1117 node
= &state
->rb_node
;
1123 * this search will find all the extents that end after
1126 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
1128 prealloc
= alloc_extent_state_atomic(prealloc
);
1133 err
= insert_state(tree
, prealloc
, start
, end
,
1134 &p
, &parent
, &bits
, NULL
);
1136 extent_io_tree_panic(tree
, err
);
1137 cache_state(prealloc
, cached_state
);
1141 state
= rb_entry(node
, struct extent_state
, rb_node
);
1143 last_start
= state
->start
;
1144 last_end
= state
->end
;
1147 * | ---- desired range ---- |
1150 * Just lock what we found and keep going
1152 if (state
->start
== start
&& state
->end
<= end
) {
1153 set_state_bits(tree
, state
, &bits
, NULL
);
1154 cache_state(state
, cached_state
);
1155 state
= clear_state_bit(tree
, state
, &clear_bits
, 0, NULL
);
1156 if (last_end
== (u64
)-1)
1158 start
= last_end
+ 1;
1159 if (start
< end
&& state
&& state
->start
== start
&&
1166 * | ---- desired range ---- |
1169 * | ------------- state -------------- |
1171 * We need to split the extent we found, and may flip bits on
1174 * If the extent we found extends past our
1175 * range, we just split and search again. It'll get split
1176 * again the next time though.
1178 * If the extent we found is inside our range, we set the
1179 * desired bit on it.
1181 if (state
->start
< start
) {
1182 prealloc
= alloc_extent_state_atomic(prealloc
);
1187 err
= split_state(tree
, state
, prealloc
, start
);
1189 extent_io_tree_panic(tree
, err
);
1193 if (state
->end
<= end
) {
1194 set_state_bits(tree
, state
, &bits
, NULL
);
1195 cache_state(state
, cached_state
);
1196 state
= clear_state_bit(tree
, state
, &clear_bits
, 0,
1198 if (last_end
== (u64
)-1)
1200 start
= last_end
+ 1;
1201 if (start
< end
&& state
&& state
->start
== start
&&
1208 * | ---- desired range ---- |
1209 * | state | or | state |
1211 * There's a hole, we need to insert something in it and
1212 * ignore the extent we found.
1214 if (state
->start
> start
) {
1216 if (end
< last_start
)
1219 this_end
= last_start
- 1;
1221 prealloc
= alloc_extent_state_atomic(prealloc
);
1228 * Avoid to free 'prealloc' if it can be merged with
1231 err
= insert_state(tree
, prealloc
, start
, this_end
,
1232 NULL
, NULL
, &bits
, NULL
);
1234 extent_io_tree_panic(tree
, err
);
1235 cache_state(prealloc
, cached_state
);
1237 start
= this_end
+ 1;
1241 * | ---- desired range ---- |
1243 * We need to split the extent, and set the bit
1246 if (state
->start
<= end
&& state
->end
> end
) {
1247 prealloc
= alloc_extent_state_atomic(prealloc
);
1253 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1255 extent_io_tree_panic(tree
, err
);
1257 set_state_bits(tree
, prealloc
, &bits
, NULL
);
1258 cache_state(prealloc
, cached_state
);
1259 clear_state_bit(tree
, prealloc
, &clear_bits
, 0, NULL
);
1267 spin_unlock(&tree
->lock
);
1269 first_iteration
= false;
1273 spin_unlock(&tree
->lock
);
1275 free_extent_state(prealloc
);
1280 /* wrappers around set/clear extent bit */
1281 int set_record_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1282 unsigned bits
, struct extent_changeset
*changeset
)
1285 * We don't support EXTENT_LOCKED yet, as current changeset will
1286 * record any bits changed, so for EXTENT_LOCKED case, it will
1287 * either fail with -EEXIST or changeset will record the whole
1290 BUG_ON(bits
& EXTENT_LOCKED
);
1292 return __set_extent_bit(tree
, start
, end
, bits
, 0, NULL
, NULL
, GFP_NOFS
,
1296 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1297 unsigned bits
, int wake
, int delete,
1298 struct extent_state
**cached
, gfp_t mask
)
1300 return __clear_extent_bit(tree
, start
, end
, bits
, wake
, delete,
1301 cached
, mask
, NULL
);
1304 int clear_record_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1305 unsigned bits
, struct extent_changeset
*changeset
)
1308 * Don't support EXTENT_LOCKED case, same reason as
1309 * set_record_extent_bits().
1311 BUG_ON(bits
& EXTENT_LOCKED
);
1313 return __clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, GFP_NOFS
,
1318 * either insert or lock state struct between start and end use mask to tell
1319 * us if waiting is desired.
1321 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1322 struct extent_state
**cached_state
)
1328 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
,
1329 EXTENT_LOCKED
, &failed_start
,
1330 cached_state
, GFP_NOFS
, NULL
);
1331 if (err
== -EEXIST
) {
1332 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1333 start
= failed_start
;
1336 WARN_ON(start
> end
);
1341 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1346 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1347 &failed_start
, NULL
, GFP_NOFS
, NULL
);
1348 if (err
== -EEXIST
) {
1349 if (failed_start
> start
)
1350 clear_extent_bit(tree
, start
, failed_start
- 1,
1351 EXTENT_LOCKED
, 1, 0, NULL
, GFP_NOFS
);
1357 void extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1359 unsigned long index
= start
>> PAGE_SHIFT
;
1360 unsigned long end_index
= end
>> PAGE_SHIFT
;
1363 while (index
<= end_index
) {
1364 page
= find_get_page(inode
->i_mapping
, index
);
1365 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1366 clear_page_dirty_for_io(page
);
1372 void extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1374 unsigned long index
= start
>> PAGE_SHIFT
;
1375 unsigned long end_index
= end
>> PAGE_SHIFT
;
1378 while (index
<= end_index
) {
1379 page
= find_get_page(inode
->i_mapping
, index
);
1380 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1381 __set_page_dirty_nobuffers(page
);
1382 account_page_redirty(page
);
1389 * helper function to set both pages and extents in the tree writeback
1391 static void set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1393 tree
->ops
->set_range_writeback(tree
->private_data
, start
, end
);
1396 /* find the first state struct with 'bits' set after 'start', and
1397 * return it. tree->lock must be held. NULL will returned if
1398 * nothing was found after 'start'
1400 static struct extent_state
*
1401 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1402 u64 start
, unsigned bits
)
1404 struct rb_node
*node
;
1405 struct extent_state
*state
;
1408 * this search will find all the extents that end after
1411 node
= tree_search(tree
, start
);
1416 state
= rb_entry(node
, struct extent_state
, rb_node
);
1417 if (state
->end
>= start
&& (state
->state
& bits
))
1420 node
= rb_next(node
);
1429 * find the first offset in the io tree with 'bits' set. zero is
1430 * returned if we find something, and *start_ret and *end_ret are
1431 * set to reflect the state struct that was found.
1433 * If nothing was found, 1 is returned. If found something, return 0.
1435 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1436 u64
*start_ret
, u64
*end_ret
, unsigned bits
,
1437 struct extent_state
**cached_state
)
1439 struct extent_state
*state
;
1443 spin_lock(&tree
->lock
);
1444 if (cached_state
&& *cached_state
) {
1445 state
= *cached_state
;
1446 if (state
->end
== start
- 1 && extent_state_in_tree(state
)) {
1447 n
= rb_next(&state
->rb_node
);
1449 state
= rb_entry(n
, struct extent_state
,
1451 if (state
->state
& bits
)
1455 free_extent_state(*cached_state
);
1456 *cached_state
= NULL
;
1459 free_extent_state(*cached_state
);
1460 *cached_state
= NULL
;
1463 state
= find_first_extent_bit_state(tree
, start
, bits
);
1466 cache_state_if_flags(state
, cached_state
, 0);
1467 *start_ret
= state
->start
;
1468 *end_ret
= state
->end
;
1472 spin_unlock(&tree
->lock
);
1477 * find a contiguous range of bytes in the file marked as delalloc, not
1478 * more than 'max_bytes'. start and end are used to return the range,
1480 * 1 is returned if we find something, 0 if nothing was in the tree
1482 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1483 u64
*start
, u64
*end
, u64 max_bytes
,
1484 struct extent_state
**cached_state
)
1486 struct rb_node
*node
;
1487 struct extent_state
*state
;
1488 u64 cur_start
= *start
;
1490 u64 total_bytes
= 0;
1492 spin_lock(&tree
->lock
);
1495 * this search will find all the extents that end after
1498 node
= tree_search(tree
, cur_start
);
1506 state
= rb_entry(node
, struct extent_state
, rb_node
);
1507 if (found
&& (state
->start
!= cur_start
||
1508 (state
->state
& EXTENT_BOUNDARY
))) {
1511 if (!(state
->state
& EXTENT_DELALLOC
)) {
1517 *start
= state
->start
;
1518 *cached_state
= state
;
1519 refcount_inc(&state
->refs
);
1523 cur_start
= state
->end
+ 1;
1524 node
= rb_next(node
);
1525 total_bytes
+= state
->end
- state
->start
+ 1;
1526 if (total_bytes
>= max_bytes
)
1532 spin_unlock(&tree
->lock
);
1536 static int __process_pages_contig(struct address_space
*mapping
,
1537 struct page
*locked_page
,
1538 pgoff_t start_index
, pgoff_t end_index
,
1539 unsigned long page_ops
, pgoff_t
*index_ret
);
1541 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1542 struct page
*locked_page
,
1545 unsigned long index
= start
>> PAGE_SHIFT
;
1546 unsigned long end_index
= end
>> PAGE_SHIFT
;
1548 ASSERT(locked_page
);
1549 if (index
== locked_page
->index
&& end_index
== index
)
1552 __process_pages_contig(inode
->i_mapping
, locked_page
, index
, end_index
,
1556 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1557 struct page
*locked_page
,
1561 unsigned long index
= delalloc_start
>> PAGE_SHIFT
;
1562 unsigned long index_ret
= index
;
1563 unsigned long end_index
= delalloc_end
>> PAGE_SHIFT
;
1566 ASSERT(locked_page
);
1567 if (index
== locked_page
->index
&& index
== end_index
)
1570 ret
= __process_pages_contig(inode
->i_mapping
, locked_page
, index
,
1571 end_index
, PAGE_LOCK
, &index_ret
);
1573 __unlock_for_delalloc(inode
, locked_page
, delalloc_start
,
1574 (u64
)index_ret
<< PAGE_SHIFT
);
1579 * find a contiguous range of bytes in the file marked as delalloc, not
1580 * more than 'max_bytes'. start and end are used to return the range,
1582 * 1 is returned if we find something, 0 if nothing was in the tree
1584 STATIC u64
find_lock_delalloc_range(struct inode
*inode
,
1585 struct extent_io_tree
*tree
,
1586 struct page
*locked_page
, u64
*start
,
1587 u64
*end
, u64 max_bytes
)
1592 struct extent_state
*cached_state
= NULL
;
1597 /* step one, find a bunch of delalloc bytes starting at start */
1598 delalloc_start
= *start
;
1600 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1601 max_bytes
, &cached_state
);
1602 if (!found
|| delalloc_end
<= *start
) {
1603 *start
= delalloc_start
;
1604 *end
= delalloc_end
;
1605 free_extent_state(cached_state
);
1610 * start comes from the offset of locked_page. We have to lock
1611 * pages in order, so we can't process delalloc bytes before
1614 if (delalloc_start
< *start
)
1615 delalloc_start
= *start
;
1618 * make sure to limit the number of pages we try to lock down
1620 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
)
1621 delalloc_end
= delalloc_start
+ max_bytes
- 1;
1623 /* step two, lock all the pages after the page that has start */
1624 ret
= lock_delalloc_pages(inode
, locked_page
,
1625 delalloc_start
, delalloc_end
);
1626 if (ret
== -EAGAIN
) {
1627 /* some of the pages are gone, lets avoid looping by
1628 * shortening the size of the delalloc range we're searching
1630 free_extent_state(cached_state
);
1631 cached_state
= NULL
;
1633 max_bytes
= PAGE_SIZE
;
1641 BUG_ON(ret
); /* Only valid values are 0 and -EAGAIN */
1643 /* step three, lock the state bits for the whole range */
1644 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, &cached_state
);
1646 /* then test to make sure it is all still delalloc */
1647 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1648 EXTENT_DELALLOC
, 1, cached_state
);
1650 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1651 &cached_state
, GFP_NOFS
);
1652 __unlock_for_delalloc(inode
, locked_page
,
1653 delalloc_start
, delalloc_end
);
1657 free_extent_state(cached_state
);
1658 *start
= delalloc_start
;
1659 *end
= delalloc_end
;
1664 static int __process_pages_contig(struct address_space
*mapping
,
1665 struct page
*locked_page
,
1666 pgoff_t start_index
, pgoff_t end_index
,
1667 unsigned long page_ops
, pgoff_t
*index_ret
)
1669 unsigned long nr_pages
= end_index
- start_index
+ 1;
1670 unsigned long pages_locked
= 0;
1671 pgoff_t index
= start_index
;
1672 struct page
*pages
[16];
1677 if (page_ops
& PAGE_LOCK
) {
1678 ASSERT(page_ops
== PAGE_LOCK
);
1679 ASSERT(index_ret
&& *index_ret
== start_index
);
1682 if ((page_ops
& PAGE_SET_ERROR
) && nr_pages
> 0)
1683 mapping_set_error(mapping
, -EIO
);
1685 while (nr_pages
> 0) {
1686 ret
= find_get_pages_contig(mapping
, index
,
1687 min_t(unsigned long,
1688 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1691 * Only if we're going to lock these pages,
1692 * can we find nothing at @index.
1694 ASSERT(page_ops
& PAGE_LOCK
);
1699 for (i
= 0; i
< ret
; i
++) {
1700 if (page_ops
& PAGE_SET_PRIVATE2
)
1701 SetPagePrivate2(pages
[i
]);
1703 if (pages
[i
] == locked_page
) {
1708 if (page_ops
& PAGE_CLEAR_DIRTY
)
1709 clear_page_dirty_for_io(pages
[i
]);
1710 if (page_ops
& PAGE_SET_WRITEBACK
)
1711 set_page_writeback(pages
[i
]);
1712 if (page_ops
& PAGE_SET_ERROR
)
1713 SetPageError(pages
[i
]);
1714 if (page_ops
& PAGE_END_WRITEBACK
)
1715 end_page_writeback(pages
[i
]);
1716 if (page_ops
& PAGE_UNLOCK
)
1717 unlock_page(pages
[i
]);
1718 if (page_ops
& PAGE_LOCK
) {
1719 lock_page(pages
[i
]);
1720 if (!PageDirty(pages
[i
]) ||
1721 pages
[i
]->mapping
!= mapping
) {
1722 unlock_page(pages
[i
]);
1736 if (err
&& index_ret
)
1737 *index_ret
= start_index
+ pages_locked
- 1;
1741 void extent_clear_unlock_delalloc(struct inode
*inode
, u64 start
, u64 end
,
1742 u64 delalloc_end
, struct page
*locked_page
,
1743 unsigned clear_bits
,
1744 unsigned long page_ops
)
1746 clear_extent_bit(&BTRFS_I(inode
)->io_tree
, start
, end
, clear_bits
, 1, 0,
1749 __process_pages_contig(inode
->i_mapping
, locked_page
,
1750 start
>> PAGE_SHIFT
, end
>> PAGE_SHIFT
,
1755 * count the number of bytes in the tree that have a given bit(s)
1756 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1757 * cached. The total number found is returned.
1759 u64
count_range_bits(struct extent_io_tree
*tree
,
1760 u64
*start
, u64 search_end
, u64 max_bytes
,
1761 unsigned bits
, int contig
)
1763 struct rb_node
*node
;
1764 struct extent_state
*state
;
1765 u64 cur_start
= *start
;
1766 u64 total_bytes
= 0;
1770 if (WARN_ON(search_end
<= cur_start
))
1773 spin_lock(&tree
->lock
);
1774 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1775 total_bytes
= tree
->dirty_bytes
;
1779 * this search will find all the extents that end after
1782 node
= tree_search(tree
, cur_start
);
1787 state
= rb_entry(node
, struct extent_state
, rb_node
);
1788 if (state
->start
> search_end
)
1790 if (contig
&& found
&& state
->start
> last
+ 1)
1792 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1793 total_bytes
+= min(search_end
, state
->end
) + 1 -
1794 max(cur_start
, state
->start
);
1795 if (total_bytes
>= max_bytes
)
1798 *start
= max(cur_start
, state
->start
);
1802 } else if (contig
&& found
) {
1805 node
= rb_next(node
);
1810 spin_unlock(&tree
->lock
);
1815 * set the private field for a given byte offset in the tree. If there isn't
1816 * an extent_state there already, this does nothing.
1818 static noinline
int set_state_failrec(struct extent_io_tree
*tree
, u64 start
,
1819 struct io_failure_record
*failrec
)
1821 struct rb_node
*node
;
1822 struct extent_state
*state
;
1825 spin_lock(&tree
->lock
);
1827 * this search will find all the extents that end after
1830 node
= tree_search(tree
, start
);
1835 state
= rb_entry(node
, struct extent_state
, rb_node
);
1836 if (state
->start
!= start
) {
1840 state
->failrec
= failrec
;
1842 spin_unlock(&tree
->lock
);
1846 static noinline
int get_state_failrec(struct extent_io_tree
*tree
, u64 start
,
1847 struct io_failure_record
**failrec
)
1849 struct rb_node
*node
;
1850 struct extent_state
*state
;
1853 spin_lock(&tree
->lock
);
1855 * this search will find all the extents that end after
1858 node
= tree_search(tree
, start
);
1863 state
= rb_entry(node
, struct extent_state
, rb_node
);
1864 if (state
->start
!= start
) {
1868 *failrec
= state
->failrec
;
1870 spin_unlock(&tree
->lock
);
1875 * searches a range in the state tree for a given mask.
1876 * If 'filled' == 1, this returns 1 only if every extent in the tree
1877 * has the bits set. Otherwise, 1 is returned if any bit in the
1878 * range is found set.
1880 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1881 unsigned bits
, int filled
, struct extent_state
*cached
)
1883 struct extent_state
*state
= NULL
;
1884 struct rb_node
*node
;
1887 spin_lock(&tree
->lock
);
1888 if (cached
&& extent_state_in_tree(cached
) && cached
->start
<= start
&&
1889 cached
->end
> start
)
1890 node
= &cached
->rb_node
;
1892 node
= tree_search(tree
, start
);
1893 while (node
&& start
<= end
) {
1894 state
= rb_entry(node
, struct extent_state
, rb_node
);
1896 if (filled
&& state
->start
> start
) {
1901 if (state
->start
> end
)
1904 if (state
->state
& bits
) {
1908 } else if (filled
) {
1913 if (state
->end
== (u64
)-1)
1916 start
= state
->end
+ 1;
1919 node
= rb_next(node
);
1926 spin_unlock(&tree
->lock
);
1931 * helper function to set a given page up to date if all the
1932 * extents in the tree for that page are up to date
1934 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
1936 u64 start
= page_offset(page
);
1937 u64 end
= start
+ PAGE_SIZE
- 1;
1938 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1939 SetPageUptodate(page
);
1942 int free_io_failure(struct extent_io_tree
*failure_tree
,
1943 struct extent_io_tree
*io_tree
,
1944 struct io_failure_record
*rec
)
1949 set_state_failrec(failure_tree
, rec
->start
, NULL
);
1950 ret
= clear_extent_bits(failure_tree
, rec
->start
,
1951 rec
->start
+ rec
->len
- 1,
1952 EXTENT_LOCKED
| EXTENT_DIRTY
);
1956 ret
= clear_extent_bits(io_tree
, rec
->start
,
1957 rec
->start
+ rec
->len
- 1,
1967 * this bypasses the standard btrfs submit functions deliberately, as
1968 * the standard behavior is to write all copies in a raid setup. here we only
1969 * want to write the one bad copy. so we do the mapping for ourselves and issue
1970 * submit_bio directly.
1971 * to avoid any synchronization issues, wait for the data after writing, which
1972 * actually prevents the read that triggered the error from finishing.
1973 * currently, there can be no more than two copies of every data bit. thus,
1974 * exactly one rewrite is required.
1976 int repair_io_failure(struct btrfs_fs_info
*fs_info
, u64 ino
, u64 start
,
1977 u64 length
, u64 logical
, struct page
*page
,
1978 unsigned int pg_offset
, int mirror_num
)
1981 struct btrfs_device
*dev
;
1984 struct btrfs_bio
*bbio
= NULL
;
1987 ASSERT(!(fs_info
->sb
->s_flags
& MS_RDONLY
));
1988 BUG_ON(!mirror_num
);
1990 bio
= btrfs_io_bio_alloc(1);
1991 bio
->bi_iter
.bi_size
= 0;
1992 map_length
= length
;
1995 * Avoid races with device replace and make sure our bbio has devices
1996 * associated to its stripes that don't go away while we are doing the
1997 * read repair operation.
1999 btrfs_bio_counter_inc_blocked(fs_info
);
2000 if (btrfs_is_parity_mirror(fs_info
, logical
, length
, mirror_num
)) {
2002 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
2003 * to update all raid stripes, but here we just want to correct
2004 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
2005 * stripe's dev and sector.
2007 ret
= btrfs_map_block(fs_info
, BTRFS_MAP_READ
, logical
,
2008 &map_length
, &bbio
, 0);
2010 btrfs_bio_counter_dec(fs_info
);
2014 ASSERT(bbio
->mirror_num
== 1);
2016 ret
= btrfs_map_block(fs_info
, BTRFS_MAP_WRITE
, logical
,
2017 &map_length
, &bbio
, mirror_num
);
2019 btrfs_bio_counter_dec(fs_info
);
2023 BUG_ON(mirror_num
!= bbio
->mirror_num
);
2026 sector
= bbio
->stripes
[bbio
->mirror_num
- 1].physical
>> 9;
2027 bio
->bi_iter
.bi_sector
= sector
;
2028 dev
= bbio
->stripes
[bbio
->mirror_num
- 1].dev
;
2029 btrfs_put_bbio(bbio
);
2030 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2031 btrfs_bio_counter_dec(fs_info
);
2035 bio
->bi_bdev
= dev
->bdev
;
2036 bio
->bi_opf
= REQ_OP_WRITE
| REQ_SYNC
;
2037 bio_add_page(bio
, page
, length
, pg_offset
);
2039 if (btrfsic_submit_bio_wait(bio
)) {
2040 /* try to remap that extent elsewhere? */
2041 btrfs_bio_counter_dec(fs_info
);
2043 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2047 btrfs_info_rl_in_rcu(fs_info
,
2048 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2050 rcu_str_deref(dev
->name
), sector
);
2051 btrfs_bio_counter_dec(fs_info
);
2056 int repair_eb_io_failure(struct btrfs_fs_info
*fs_info
,
2057 struct extent_buffer
*eb
, int mirror_num
)
2059 u64 start
= eb
->start
;
2060 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2063 if (fs_info
->sb
->s_flags
& MS_RDONLY
)
2066 for (i
= 0; i
< num_pages
; i
++) {
2067 struct page
*p
= eb
->pages
[i
];
2069 ret
= repair_io_failure(fs_info
, 0, start
, PAGE_SIZE
, start
, p
,
2070 start
- page_offset(p
), mirror_num
);
2080 * each time an IO finishes, we do a fast check in the IO failure tree
2081 * to see if we need to process or clean up an io_failure_record
2083 int clean_io_failure(struct btrfs_fs_info
*fs_info
,
2084 struct extent_io_tree
*failure_tree
,
2085 struct extent_io_tree
*io_tree
, u64 start
,
2086 struct page
*page
, u64 ino
, unsigned int pg_offset
)
2089 struct io_failure_record
*failrec
;
2090 struct extent_state
*state
;
2095 ret
= count_range_bits(failure_tree
, &private, (u64
)-1, 1,
2100 ret
= get_state_failrec(failure_tree
, start
, &failrec
);
2104 BUG_ON(!failrec
->this_mirror
);
2106 if (failrec
->in_validation
) {
2107 /* there was no real error, just free the record */
2108 btrfs_debug(fs_info
,
2109 "clean_io_failure: freeing dummy error at %llu",
2113 if (fs_info
->sb
->s_flags
& MS_RDONLY
)
2116 spin_lock(&io_tree
->lock
);
2117 state
= find_first_extent_bit_state(io_tree
,
2120 spin_unlock(&io_tree
->lock
);
2122 if (state
&& state
->start
<= failrec
->start
&&
2123 state
->end
>= failrec
->start
+ failrec
->len
- 1) {
2124 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2126 if (num_copies
> 1) {
2127 repair_io_failure(fs_info
, ino
, start
, failrec
->len
,
2128 failrec
->logical
, page
, pg_offset
,
2129 failrec
->failed_mirror
);
2134 free_io_failure(failure_tree
, io_tree
, failrec
);
2140 * Can be called when
2141 * - hold extent lock
2142 * - under ordered extent
2143 * - the inode is freeing
2145 void btrfs_free_io_failure_record(struct btrfs_inode
*inode
, u64 start
, u64 end
)
2147 struct extent_io_tree
*failure_tree
= &inode
->io_failure_tree
;
2148 struct io_failure_record
*failrec
;
2149 struct extent_state
*state
, *next
;
2151 if (RB_EMPTY_ROOT(&failure_tree
->state
))
2154 spin_lock(&failure_tree
->lock
);
2155 state
= find_first_extent_bit_state(failure_tree
, start
, EXTENT_DIRTY
);
2157 if (state
->start
> end
)
2160 ASSERT(state
->end
<= end
);
2162 next
= next_state(state
);
2164 failrec
= state
->failrec
;
2165 free_extent_state(state
);
2170 spin_unlock(&failure_tree
->lock
);
2173 int btrfs_get_io_failure_record(struct inode
*inode
, u64 start
, u64 end
,
2174 struct io_failure_record
**failrec_ret
)
2176 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2177 struct io_failure_record
*failrec
;
2178 struct extent_map
*em
;
2179 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2180 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2181 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2185 ret
= get_state_failrec(failure_tree
, start
, &failrec
);
2187 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2191 failrec
->start
= start
;
2192 failrec
->len
= end
- start
+ 1;
2193 failrec
->this_mirror
= 0;
2194 failrec
->bio_flags
= 0;
2195 failrec
->in_validation
= 0;
2197 read_lock(&em_tree
->lock
);
2198 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2200 read_unlock(&em_tree
->lock
);
2205 if (em
->start
> start
|| em
->start
+ em
->len
<= start
) {
2206 free_extent_map(em
);
2209 read_unlock(&em_tree
->lock
);
2215 logical
= start
- em
->start
;
2216 logical
= em
->block_start
+ logical
;
2217 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2218 logical
= em
->block_start
;
2219 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2220 extent_set_compress_type(&failrec
->bio_flags
,
2224 btrfs_debug(fs_info
,
2225 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2226 logical
, start
, failrec
->len
);
2228 failrec
->logical
= logical
;
2229 free_extent_map(em
);
2231 /* set the bits in the private failure tree */
2232 ret
= set_extent_bits(failure_tree
, start
, end
,
2233 EXTENT_LOCKED
| EXTENT_DIRTY
);
2235 ret
= set_state_failrec(failure_tree
, start
, failrec
);
2236 /* set the bits in the inode's tree */
2238 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
);
2244 btrfs_debug(fs_info
,
2245 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2246 failrec
->logical
, failrec
->start
, failrec
->len
,
2247 failrec
->in_validation
);
2249 * when data can be on disk more than twice, add to failrec here
2250 * (e.g. with a list for failed_mirror) to make
2251 * clean_io_failure() clean all those errors at once.
2255 *failrec_ret
= failrec
;
2260 int btrfs_check_repairable(struct inode
*inode
, struct bio
*failed_bio
,
2261 struct io_failure_record
*failrec
, int failed_mirror
)
2263 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2266 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
, failrec
->len
);
2267 if (num_copies
== 1) {
2269 * we only have a single copy of the data, so don't bother with
2270 * all the retry and error correction code that follows. no
2271 * matter what the error is, it is very likely to persist.
2273 btrfs_debug(fs_info
,
2274 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2275 num_copies
, failrec
->this_mirror
, failed_mirror
);
2280 * there are two premises:
2281 * a) deliver good data to the caller
2282 * b) correct the bad sectors on disk
2284 if (failed_bio
->bi_vcnt
> 1) {
2286 * to fulfill b), we need to know the exact failing sectors, as
2287 * we don't want to rewrite any more than the failed ones. thus,
2288 * we need separate read requests for the failed bio
2290 * if the following BUG_ON triggers, our validation request got
2291 * merged. we need separate requests for our algorithm to work.
2293 BUG_ON(failrec
->in_validation
);
2294 failrec
->in_validation
= 1;
2295 failrec
->this_mirror
= failed_mirror
;
2298 * we're ready to fulfill a) and b) alongside. get a good copy
2299 * of the failed sector and if we succeed, we have setup
2300 * everything for repair_io_failure to do the rest for us.
2302 if (failrec
->in_validation
) {
2303 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2304 failrec
->in_validation
= 0;
2305 failrec
->this_mirror
= 0;
2307 failrec
->failed_mirror
= failed_mirror
;
2308 failrec
->this_mirror
++;
2309 if (failrec
->this_mirror
== failed_mirror
)
2310 failrec
->this_mirror
++;
2313 if (failrec
->this_mirror
> num_copies
) {
2314 btrfs_debug(fs_info
,
2315 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2316 num_copies
, failrec
->this_mirror
, failed_mirror
);
2324 struct bio
*btrfs_create_repair_bio(struct inode
*inode
, struct bio
*failed_bio
,
2325 struct io_failure_record
*failrec
,
2326 struct page
*page
, int pg_offset
, int icsum
,
2327 bio_end_io_t
*endio_func
, void *data
)
2329 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2331 struct btrfs_io_bio
*btrfs_failed_bio
;
2332 struct btrfs_io_bio
*btrfs_bio
;
2334 bio
= btrfs_io_bio_alloc(1);
2335 bio
->bi_end_io
= endio_func
;
2336 bio
->bi_iter
.bi_sector
= failrec
->logical
>> 9;
2337 bio
->bi_bdev
= fs_info
->fs_devices
->latest_bdev
;
2338 bio
->bi_iter
.bi_size
= 0;
2339 bio
->bi_private
= data
;
2341 btrfs_failed_bio
= btrfs_io_bio(failed_bio
);
2342 if (btrfs_failed_bio
->csum
) {
2343 u16 csum_size
= btrfs_super_csum_size(fs_info
->super_copy
);
2345 btrfs_bio
= btrfs_io_bio(bio
);
2346 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
2348 memcpy(btrfs_bio
->csum
, btrfs_failed_bio
->csum
+ icsum
,
2352 bio_add_page(bio
, page
, failrec
->len
, pg_offset
);
2358 * this is a generic handler for readpage errors (default
2359 * readpage_io_failed_hook). if other copies exist, read those and write back
2360 * good data to the failed position. does not investigate in remapping the
2361 * failed extent elsewhere, hoping the device will be smart enough to do this as
2365 static int bio_readpage_error(struct bio
*failed_bio
, u64 phy_offset
,
2366 struct page
*page
, u64 start
, u64 end
,
2369 struct io_failure_record
*failrec
;
2370 struct inode
*inode
= page
->mapping
->host
;
2371 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2372 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2377 BUG_ON(bio_op(failed_bio
) == REQ_OP_WRITE
);
2379 ret
= btrfs_get_io_failure_record(inode
, start
, end
, &failrec
);
2383 ret
= btrfs_check_repairable(inode
, failed_bio
, failrec
, failed_mirror
);
2385 free_io_failure(failure_tree
, tree
, failrec
);
2389 if (failed_bio
->bi_vcnt
> 1)
2390 read_mode
|= REQ_FAILFAST_DEV
;
2392 phy_offset
>>= inode
->i_sb
->s_blocksize_bits
;
2393 bio
= btrfs_create_repair_bio(inode
, failed_bio
, failrec
, page
,
2394 start
- page_offset(page
),
2395 (int)phy_offset
, failed_bio
->bi_end_io
,
2397 bio_set_op_attrs(bio
, REQ_OP_READ
, read_mode
);
2399 btrfs_debug(btrfs_sb(inode
->i_sb
),
2400 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2401 read_mode
, failrec
->this_mirror
, failrec
->in_validation
);
2403 ret
= tree
->ops
->submit_bio_hook(tree
->private_data
, bio
, failrec
->this_mirror
,
2404 failrec
->bio_flags
, 0);
2406 free_io_failure(failure_tree
, tree
, failrec
);
2413 /* lots and lots of room for performance fixes in the end_bio funcs */
2415 void end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2417 int uptodate
= (err
== 0);
2418 struct extent_io_tree
*tree
;
2421 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2423 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2424 tree
->ops
->writepage_end_io_hook(page
, start
, end
, NULL
,
2428 ClearPageUptodate(page
);
2430 ret
= err
< 0 ? err
: -EIO
;
2431 mapping_set_error(page
->mapping
, ret
);
2436 * after a writepage IO is done, we need to:
2437 * clear the uptodate bits on error
2438 * clear the writeback bits in the extent tree for this IO
2439 * end_page_writeback if the page has no more pending IO
2441 * Scheduling is not allowed, so the extent state tree is expected
2442 * to have one and only one object corresponding to this IO.
2444 static void end_bio_extent_writepage(struct bio
*bio
)
2446 struct bio_vec
*bvec
;
2451 ASSERT(!bio_flagged(bio
, BIO_CLONED
));
2452 bio_for_each_segment_all(bvec
, bio
, i
) {
2453 struct page
*page
= bvec
->bv_page
;
2454 struct inode
*inode
= page
->mapping
->host
;
2455 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2457 /* We always issue full-page reads, but if some block
2458 * in a page fails to read, blk_update_request() will
2459 * advance bv_offset and adjust bv_len to compensate.
2460 * Print a warning for nonzero offsets, and an error
2461 * if they don't add up to a full page. */
2462 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_SIZE
) {
2463 if (bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_SIZE
)
2465 "partial page write in btrfs with offset %u and length %u",
2466 bvec
->bv_offset
, bvec
->bv_len
);
2469 "incomplete page write in btrfs with offset %u and length %u",
2470 bvec
->bv_offset
, bvec
->bv_len
);
2473 start
= page_offset(page
);
2474 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2476 end_extent_writepage(page
, bio
->bi_error
, start
, end
);
2477 end_page_writeback(page
);
2484 endio_readpage_release_extent(struct extent_io_tree
*tree
, u64 start
, u64 len
,
2487 struct extent_state
*cached
= NULL
;
2488 u64 end
= start
+ len
- 1;
2490 if (uptodate
&& tree
->track_uptodate
)
2491 set_extent_uptodate(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2492 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2496 * after a readpage IO is done, we need to:
2497 * clear the uptodate bits on error
2498 * set the uptodate bits if things worked
2499 * set the page up to date if all extents in the tree are uptodate
2500 * clear the lock bit in the extent tree
2501 * unlock the page if there are no other extents locked for it
2503 * Scheduling is not allowed, so the extent state tree is expected
2504 * to have one and only one object corresponding to this IO.
2506 static void end_bio_extent_readpage(struct bio
*bio
)
2508 struct bio_vec
*bvec
;
2509 int uptodate
= !bio
->bi_error
;
2510 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2511 struct extent_io_tree
*tree
, *failure_tree
;
2516 u64 extent_start
= 0;
2522 ASSERT(!bio_flagged(bio
, BIO_CLONED
));
2523 bio_for_each_segment_all(bvec
, bio
, i
) {
2524 struct page
*page
= bvec
->bv_page
;
2525 struct inode
*inode
= page
->mapping
->host
;
2526 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2528 btrfs_debug(fs_info
,
2529 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2530 (u64
)bio
->bi_iter
.bi_sector
, bio
->bi_error
,
2531 io_bio
->mirror_num
);
2532 tree
= &BTRFS_I(inode
)->io_tree
;
2533 failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2535 /* We always issue full-page reads, but if some block
2536 * in a page fails to read, blk_update_request() will
2537 * advance bv_offset and adjust bv_len to compensate.
2538 * Print a warning for nonzero offsets, and an error
2539 * if they don't add up to a full page. */
2540 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_SIZE
) {
2541 if (bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_SIZE
)
2543 "partial page read in btrfs with offset %u and length %u",
2544 bvec
->bv_offset
, bvec
->bv_len
);
2547 "incomplete page read in btrfs with offset %u and length %u",
2548 bvec
->bv_offset
, bvec
->bv_len
);
2551 start
= page_offset(page
);
2552 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2555 mirror
= io_bio
->mirror_num
;
2556 if (likely(uptodate
&& tree
->ops
)) {
2557 ret
= tree
->ops
->readpage_end_io_hook(io_bio
, offset
,
2563 clean_io_failure(BTRFS_I(inode
)->root
->fs_info
,
2564 failure_tree
, tree
, start
,
2566 btrfs_ino(BTRFS_I(inode
)), 0);
2569 if (likely(uptodate
))
2573 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2574 if (ret
== -EAGAIN
) {
2576 * Data inode's readpage_io_failed_hook() always
2579 * The generic bio_readpage_error handles errors
2580 * the following way: If possible, new read
2581 * requests are created and submitted and will
2582 * end up in end_bio_extent_readpage as well (if
2583 * we're lucky, not in the !uptodate case). In
2584 * that case it returns 0 and we just go on with
2585 * the next page in our bio. If it can't handle
2586 * the error it will return -EIO and we remain
2587 * responsible for that page.
2589 ret
= bio_readpage_error(bio
, offset
, page
,
2590 start
, end
, mirror
);
2592 uptodate
= !bio
->bi_error
;
2599 * metadata's readpage_io_failed_hook() always returns
2600 * -EIO and fixes nothing. -EIO is also returned if
2601 * data inode error could not be fixed.
2603 ASSERT(ret
== -EIO
);
2606 if (likely(uptodate
)) {
2607 loff_t i_size
= i_size_read(inode
);
2608 pgoff_t end_index
= i_size
>> PAGE_SHIFT
;
2611 /* Zero out the end if this page straddles i_size */
2612 off
= i_size
& (PAGE_SIZE
-1);
2613 if (page
->index
== end_index
&& off
)
2614 zero_user_segment(page
, off
, PAGE_SIZE
);
2615 SetPageUptodate(page
);
2617 ClearPageUptodate(page
);
2623 if (unlikely(!uptodate
)) {
2625 endio_readpage_release_extent(tree
,
2631 endio_readpage_release_extent(tree
, start
,
2632 end
- start
+ 1, 0);
2633 } else if (!extent_len
) {
2634 extent_start
= start
;
2635 extent_len
= end
+ 1 - start
;
2636 } else if (extent_start
+ extent_len
== start
) {
2637 extent_len
+= end
+ 1 - start
;
2639 endio_readpage_release_extent(tree
, extent_start
,
2640 extent_len
, uptodate
);
2641 extent_start
= start
;
2642 extent_len
= end
+ 1 - start
;
2647 endio_readpage_release_extent(tree
, extent_start
, extent_len
,
2650 io_bio
->end_io(io_bio
, bio
->bi_error
);
2655 * Initialize the members up to but not including 'bio'. Use after allocating a
2656 * new bio by bio_alloc_bioset as it does not initialize the bytes outside of
2657 * 'bio' because use of __GFP_ZERO is not supported.
2659 static inline void btrfs_io_bio_init(struct btrfs_io_bio
*btrfs_bio
)
2661 memset(btrfs_bio
, 0, offsetof(struct btrfs_io_bio
, bio
));
2665 * The following helpers allocate a bio. As it's backed by a bioset, it'll
2666 * never fail. We're returning a bio right now but you can call btrfs_io_bio
2667 * for the appropriate container_of magic
2669 struct bio
*btrfs_bio_alloc(struct block_device
*bdev
, u64 first_byte
)
2673 bio
= bio_alloc_bioset(GFP_NOFS
, BIO_MAX_PAGES
, btrfs_bioset
);
2674 bio
->bi_bdev
= bdev
;
2675 bio
->bi_iter
.bi_sector
= first_byte
>> 9;
2676 btrfs_io_bio_init(btrfs_io_bio(bio
));
2680 struct bio
*btrfs_bio_clone(struct bio
*bio
)
2682 struct btrfs_io_bio
*btrfs_bio
;
2685 /* Bio allocation backed by a bioset does not fail */
2686 new = bio_clone_fast(bio
, GFP_NOFS
, btrfs_bioset
);
2687 btrfs_bio
= btrfs_io_bio(new);
2688 btrfs_io_bio_init(btrfs_bio
);
2689 btrfs_bio
->iter
= bio
->bi_iter
;
2693 struct bio
*btrfs_io_bio_alloc(unsigned int nr_iovecs
)
2697 /* Bio allocation backed by a bioset does not fail */
2698 bio
= bio_alloc_bioset(GFP_NOFS
, nr_iovecs
, btrfs_bioset
);
2699 btrfs_io_bio_init(btrfs_io_bio(bio
));
2703 struct bio
*btrfs_bio_clone_partial(struct bio
*orig
, int offset
, int size
)
2706 struct btrfs_io_bio
*btrfs_bio
;
2708 /* this will never fail when it's backed by a bioset */
2709 bio
= bio_clone_fast(orig
, GFP_NOFS
, btrfs_bioset
);
2712 btrfs_bio
= btrfs_io_bio(bio
);
2713 btrfs_io_bio_init(btrfs_bio
);
2715 bio_trim(bio
, offset
>> 9, size
>> 9);
2716 btrfs_bio
->iter
= bio
->bi_iter
;
2720 static int __must_check
submit_one_bio(struct bio
*bio
, int mirror_num
,
2721 unsigned long bio_flags
)
2724 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2725 struct page
*page
= bvec
->bv_page
;
2726 struct extent_io_tree
*tree
= bio
->bi_private
;
2729 start
= page_offset(page
) + bvec
->bv_offset
;
2731 bio
->bi_private
= NULL
;
2735 ret
= tree
->ops
->submit_bio_hook(tree
->private_data
, bio
,
2736 mirror_num
, bio_flags
, start
);
2738 btrfsic_submit_bio(bio
);
2744 static int merge_bio(struct extent_io_tree
*tree
, struct page
*page
,
2745 unsigned long offset
, size_t size
, struct bio
*bio
,
2746 unsigned long bio_flags
)
2750 ret
= tree
->ops
->merge_bio_hook(page
, offset
, size
, bio
,
2756 static int submit_extent_page(int op
, int op_flags
, struct extent_io_tree
*tree
,
2757 struct writeback_control
*wbc
,
2758 struct page
*page
, sector_t sector
,
2759 size_t size
, unsigned long offset
,
2760 struct block_device
*bdev
,
2761 struct bio
**bio_ret
,
2762 bio_end_io_t end_io_func
,
2764 unsigned long prev_bio_flags
,
2765 unsigned long bio_flags
,
2766 bool force_bio_submit
)
2771 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2772 size_t page_size
= min_t(size_t, size
, PAGE_SIZE
);
2774 if (bio_ret
&& *bio_ret
) {
2777 contig
= bio
->bi_iter
.bi_sector
== sector
;
2779 contig
= bio_end_sector(bio
) == sector
;
2781 if (prev_bio_flags
!= bio_flags
|| !contig
||
2783 merge_bio(tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2784 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2785 ret
= submit_one_bio(bio
, mirror_num
, prev_bio_flags
);
2793 wbc_account_io(wbc
, page
, page_size
);
2798 bio
= btrfs_bio_alloc(bdev
, sector
<< 9);
2799 bio_add_page(bio
, page
, page_size
, offset
);
2800 bio
->bi_end_io
= end_io_func
;
2801 bio
->bi_private
= tree
;
2802 bio_set_op_attrs(bio
, op
, op_flags
);
2804 wbc_init_bio(wbc
, bio
);
2805 wbc_account_io(wbc
, page
, page_size
);
2811 ret
= submit_one_bio(bio
, mirror_num
, bio_flags
);
2816 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2819 if (!PagePrivate(page
)) {
2820 SetPagePrivate(page
);
2822 set_page_private(page
, (unsigned long)eb
);
2824 WARN_ON(page
->private != (unsigned long)eb
);
2828 void set_page_extent_mapped(struct page
*page
)
2830 if (!PagePrivate(page
)) {
2831 SetPagePrivate(page
);
2833 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2837 static struct extent_map
*
2838 __get_extent_map(struct inode
*inode
, struct page
*page
, size_t pg_offset
,
2839 u64 start
, u64 len
, get_extent_t
*get_extent
,
2840 struct extent_map
**em_cached
)
2842 struct extent_map
*em
;
2844 if (em_cached
&& *em_cached
) {
2846 if (extent_map_in_tree(em
) && start
>= em
->start
&&
2847 start
< extent_map_end(em
)) {
2848 refcount_inc(&em
->refs
);
2852 free_extent_map(em
);
2856 em
= get_extent(BTRFS_I(inode
), page
, pg_offset
, start
, len
, 0);
2857 if (em_cached
&& !IS_ERR_OR_NULL(em
)) {
2859 refcount_inc(&em
->refs
);
2865 * basic readpage implementation. Locked extent state structs are inserted
2866 * into the tree that are removed when the IO is done (by the end_io
2868 * XXX JDM: This needs looking at to ensure proper page locking
2869 * return 0 on success, otherwise return error
2871 static int __do_readpage(struct extent_io_tree
*tree
,
2873 get_extent_t
*get_extent
,
2874 struct extent_map
**em_cached
,
2875 struct bio
**bio
, int mirror_num
,
2876 unsigned long *bio_flags
, int read_flags
,
2879 struct inode
*inode
= page
->mapping
->host
;
2880 u64 start
= page_offset(page
);
2881 u64 page_end
= start
+ PAGE_SIZE
- 1;
2885 u64 last_byte
= i_size_read(inode
);
2889 struct extent_map
*em
;
2890 struct block_device
*bdev
;
2893 size_t pg_offset
= 0;
2895 size_t disk_io_size
;
2896 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2897 unsigned long this_bio_flag
= 0;
2899 set_page_extent_mapped(page
);
2902 if (!PageUptodate(page
)) {
2903 if (cleancache_get_page(page
) == 0) {
2904 BUG_ON(blocksize
!= PAGE_SIZE
);
2905 unlock_extent(tree
, start
, end
);
2910 if (page
->index
== last_byte
>> PAGE_SHIFT
) {
2912 size_t zero_offset
= last_byte
& (PAGE_SIZE
- 1);
2915 iosize
= PAGE_SIZE
- zero_offset
;
2916 userpage
= kmap_atomic(page
);
2917 memset(userpage
+ zero_offset
, 0, iosize
);
2918 flush_dcache_page(page
);
2919 kunmap_atomic(userpage
);
2922 while (cur
<= end
) {
2923 bool force_bio_submit
= false;
2925 if (cur
>= last_byte
) {
2927 struct extent_state
*cached
= NULL
;
2929 iosize
= PAGE_SIZE
- pg_offset
;
2930 userpage
= kmap_atomic(page
);
2931 memset(userpage
+ pg_offset
, 0, iosize
);
2932 flush_dcache_page(page
);
2933 kunmap_atomic(userpage
);
2934 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2936 unlock_extent_cached(tree
, cur
,
2941 em
= __get_extent_map(inode
, page
, pg_offset
, cur
,
2942 end
- cur
+ 1, get_extent
, em_cached
);
2943 if (IS_ERR_OR_NULL(em
)) {
2945 unlock_extent(tree
, cur
, end
);
2948 extent_offset
= cur
- em
->start
;
2949 BUG_ON(extent_map_end(em
) <= cur
);
2952 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2953 this_bio_flag
|= EXTENT_BIO_COMPRESSED
;
2954 extent_set_compress_type(&this_bio_flag
,
2958 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2959 cur_end
= min(extent_map_end(em
) - 1, end
);
2960 iosize
= ALIGN(iosize
, blocksize
);
2961 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2962 disk_io_size
= em
->block_len
;
2963 sector
= em
->block_start
>> 9;
2965 sector
= (em
->block_start
+ extent_offset
) >> 9;
2966 disk_io_size
= iosize
;
2969 block_start
= em
->block_start
;
2970 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2971 block_start
= EXTENT_MAP_HOLE
;
2974 * If we have a file range that points to a compressed extent
2975 * and it's followed by a consecutive file range that points to
2976 * to the same compressed extent (possibly with a different
2977 * offset and/or length, so it either points to the whole extent
2978 * or only part of it), we must make sure we do not submit a
2979 * single bio to populate the pages for the 2 ranges because
2980 * this makes the compressed extent read zero out the pages
2981 * belonging to the 2nd range. Imagine the following scenario:
2984 * [0 - 8K] [8K - 24K]
2987 * points to extent X, points to extent X,
2988 * offset 4K, length of 8K offset 0, length 16K
2990 * [extent X, compressed length = 4K uncompressed length = 16K]
2992 * If the bio to read the compressed extent covers both ranges,
2993 * it will decompress extent X into the pages belonging to the
2994 * first range and then it will stop, zeroing out the remaining
2995 * pages that belong to the other range that points to extent X.
2996 * So here we make sure we submit 2 bios, one for the first
2997 * range and another one for the third range. Both will target
2998 * the same physical extent from disk, but we can't currently
2999 * make the compressed bio endio callback populate the pages
3000 * for both ranges because each compressed bio is tightly
3001 * coupled with a single extent map, and each range can have
3002 * an extent map with a different offset value relative to the
3003 * uncompressed data of our extent and different lengths. This
3004 * is a corner case so we prioritize correctness over
3005 * non-optimal behavior (submitting 2 bios for the same extent).
3007 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
) &&
3008 prev_em_start
&& *prev_em_start
!= (u64
)-1 &&
3009 *prev_em_start
!= em
->orig_start
)
3010 force_bio_submit
= true;
3013 *prev_em_start
= em
->orig_start
;
3015 free_extent_map(em
);
3018 /* we've found a hole, just zero and go on */
3019 if (block_start
== EXTENT_MAP_HOLE
) {
3021 struct extent_state
*cached
= NULL
;
3023 userpage
= kmap_atomic(page
);
3024 memset(userpage
+ pg_offset
, 0, iosize
);
3025 flush_dcache_page(page
);
3026 kunmap_atomic(userpage
);
3028 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
3030 unlock_extent_cached(tree
, cur
,
3034 pg_offset
+= iosize
;
3037 /* the get_extent function already copied into the page */
3038 if (test_range_bit(tree
, cur
, cur_end
,
3039 EXTENT_UPTODATE
, 1, NULL
)) {
3040 check_page_uptodate(tree
, page
);
3041 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3043 pg_offset
+= iosize
;
3046 /* we have an inline extent but it didn't get marked up
3047 * to date. Error out
3049 if (block_start
== EXTENT_MAP_INLINE
) {
3051 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3053 pg_offset
+= iosize
;
3057 ret
= submit_extent_page(REQ_OP_READ
, read_flags
, tree
, NULL
,
3058 page
, sector
, disk_io_size
, pg_offset
,
3060 end_bio_extent_readpage
, mirror_num
,
3066 *bio_flags
= this_bio_flag
;
3069 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3073 pg_offset
+= iosize
;
3077 if (!PageError(page
))
3078 SetPageUptodate(page
);
3084 static inline void __do_contiguous_readpages(struct extent_io_tree
*tree
,
3085 struct page
*pages
[], int nr_pages
,
3087 get_extent_t
*get_extent
,
3088 struct extent_map
**em_cached
,
3089 struct bio
**bio
, int mirror_num
,
3090 unsigned long *bio_flags
,
3093 struct inode
*inode
;
3094 struct btrfs_ordered_extent
*ordered
;
3097 inode
= pages
[0]->mapping
->host
;
3099 lock_extent(tree
, start
, end
);
3100 ordered
= btrfs_lookup_ordered_range(BTRFS_I(inode
), start
,
3104 unlock_extent(tree
, start
, end
);
3105 btrfs_start_ordered_extent(inode
, ordered
, 1);
3106 btrfs_put_ordered_extent(ordered
);
3109 for (index
= 0; index
< nr_pages
; index
++) {
3110 __do_readpage(tree
, pages
[index
], get_extent
, em_cached
, bio
,
3111 mirror_num
, bio_flags
, 0, prev_em_start
);
3112 put_page(pages
[index
]);
3116 static void __extent_readpages(struct extent_io_tree
*tree
,
3117 struct page
*pages
[],
3118 int nr_pages
, get_extent_t
*get_extent
,
3119 struct extent_map
**em_cached
,
3120 struct bio
**bio
, int mirror_num
,
3121 unsigned long *bio_flags
,
3128 int first_index
= 0;
3130 for (index
= 0; index
< nr_pages
; index
++) {
3131 page_start
= page_offset(pages
[index
]);
3134 end
= start
+ PAGE_SIZE
- 1;
3135 first_index
= index
;
3136 } else if (end
+ 1 == page_start
) {
3139 __do_contiguous_readpages(tree
, &pages
[first_index
],
3140 index
- first_index
, start
,
3141 end
, get_extent
, em_cached
,
3142 bio
, mirror_num
, bio_flags
,
3145 end
= start
+ PAGE_SIZE
- 1;
3146 first_index
= index
;
3151 __do_contiguous_readpages(tree
, &pages
[first_index
],
3152 index
- first_index
, start
,
3153 end
, get_extent
, em_cached
, bio
,
3154 mirror_num
, bio_flags
,
3158 static int __extent_read_full_page(struct extent_io_tree
*tree
,
3160 get_extent_t
*get_extent
,
3161 struct bio
**bio
, int mirror_num
,
3162 unsigned long *bio_flags
, int read_flags
)
3164 struct inode
*inode
= page
->mapping
->host
;
3165 struct btrfs_ordered_extent
*ordered
;
3166 u64 start
= page_offset(page
);
3167 u64 end
= start
+ PAGE_SIZE
- 1;
3171 lock_extent(tree
, start
, end
);
3172 ordered
= btrfs_lookup_ordered_range(BTRFS_I(inode
), start
,
3176 unlock_extent(tree
, start
, end
);
3177 btrfs_start_ordered_extent(inode
, ordered
, 1);
3178 btrfs_put_ordered_extent(ordered
);
3181 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, bio
, mirror_num
,
3182 bio_flags
, read_flags
, NULL
);
3186 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3187 get_extent_t
*get_extent
, int mirror_num
)
3189 struct bio
*bio
= NULL
;
3190 unsigned long bio_flags
= 0;
3193 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
3196 ret
= submit_one_bio(bio
, mirror_num
, bio_flags
);
3200 static void update_nr_written(struct writeback_control
*wbc
,
3201 unsigned long nr_written
)
3203 wbc
->nr_to_write
-= nr_written
;
3207 * helper for __extent_writepage, doing all of the delayed allocation setup.
3209 * This returns 1 if our fill_delalloc function did all the work required
3210 * to write the page (copy into inline extent). In this case the IO has
3211 * been started and the page is already unlocked.
3213 * This returns 0 if all went well (page still locked)
3214 * This returns < 0 if there were errors (page still locked)
3216 static noinline_for_stack
int writepage_delalloc(struct inode
*inode
,
3217 struct page
*page
, struct writeback_control
*wbc
,
3218 struct extent_page_data
*epd
,
3220 unsigned long *nr_written
)
3222 struct extent_io_tree
*tree
= epd
->tree
;
3223 u64 page_end
= delalloc_start
+ PAGE_SIZE
- 1;
3225 u64 delalloc_to_write
= 0;
3226 u64 delalloc_end
= 0;
3228 int page_started
= 0;
3230 if (epd
->extent_locked
|| !tree
->ops
|| !tree
->ops
->fill_delalloc
)
3233 while (delalloc_end
< page_end
) {
3234 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
3238 BTRFS_MAX_EXTENT_SIZE
);
3239 if (nr_delalloc
== 0) {
3240 delalloc_start
= delalloc_end
+ 1;
3243 ret
= tree
->ops
->fill_delalloc(inode
, page
,
3248 /* File system has been set read-only */
3251 /* fill_delalloc should be return < 0 for error
3252 * but just in case, we use > 0 here meaning the
3253 * IO is started, so we don't want to return > 0
3254 * unless things are going well.
3256 ret
= ret
< 0 ? ret
: -EIO
;
3260 * delalloc_end is already one less than the total length, so
3261 * we don't subtract one from PAGE_SIZE
3263 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3264 PAGE_SIZE
) >> PAGE_SHIFT
;
3265 delalloc_start
= delalloc_end
+ 1;
3267 if (wbc
->nr_to_write
< delalloc_to_write
) {
3270 if (delalloc_to_write
< thresh
* 2)
3271 thresh
= delalloc_to_write
;
3272 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3276 /* did the fill delalloc function already unlock and start
3281 * we've unlocked the page, so we can't update
3282 * the mapping's writeback index, just update
3285 wbc
->nr_to_write
-= *nr_written
;
3296 * helper for __extent_writepage. This calls the writepage start hooks,
3297 * and does the loop to map the page into extents and bios.
3299 * We return 1 if the IO is started and the page is unlocked,
3300 * 0 if all went well (page still locked)
3301 * < 0 if there were errors (page still locked)
3303 static noinline_for_stack
int __extent_writepage_io(struct inode
*inode
,
3305 struct writeback_control
*wbc
,
3306 struct extent_page_data
*epd
,
3308 unsigned long nr_written
,
3309 int write_flags
, int *nr_ret
)
3311 struct extent_io_tree
*tree
= epd
->tree
;
3312 u64 start
= page_offset(page
);
3313 u64 page_end
= start
+ PAGE_SIZE
- 1;
3320 struct extent_map
*em
;
3321 struct block_device
*bdev
;
3322 size_t pg_offset
= 0;
3328 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3329 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3332 /* Fixup worker will requeue */
3334 wbc
->pages_skipped
++;
3336 redirty_page_for_writepage(wbc
, page
);
3338 update_nr_written(wbc
, nr_written
);
3345 * we don't want to touch the inode after unlocking the page,
3346 * so we update the mapping writeback index now
3348 update_nr_written(wbc
, nr_written
+ 1);
3351 if (i_size
<= start
) {
3352 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3353 tree
->ops
->writepage_end_io_hook(page
, start
,
3358 blocksize
= inode
->i_sb
->s_blocksize
;
3360 while (cur
<= end
) {
3363 if (cur
>= i_size
) {
3364 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3365 tree
->ops
->writepage_end_io_hook(page
, cur
,
3369 em
= epd
->get_extent(BTRFS_I(inode
), page
, pg_offset
, cur
,
3371 if (IS_ERR_OR_NULL(em
)) {
3373 ret
= PTR_ERR_OR_ZERO(em
);
3377 extent_offset
= cur
- em
->start
;
3378 em_end
= extent_map_end(em
);
3379 BUG_ON(em_end
<= cur
);
3381 iosize
= min(em_end
- cur
, end
- cur
+ 1);
3382 iosize
= ALIGN(iosize
, blocksize
);
3383 sector
= (em
->block_start
+ extent_offset
) >> 9;
3385 block_start
= em
->block_start
;
3386 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3387 free_extent_map(em
);
3391 * compressed and inline extents are written through other
3394 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3395 block_start
== EXTENT_MAP_INLINE
) {
3397 * end_io notification does not happen here for
3398 * compressed extents
3400 if (!compressed
&& tree
->ops
&&
3401 tree
->ops
->writepage_end_io_hook
)
3402 tree
->ops
->writepage_end_io_hook(page
, cur
,
3405 else if (compressed
) {
3406 /* we don't want to end_page_writeback on
3407 * a compressed extent. this happens
3414 pg_offset
+= iosize
;
3418 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3419 if (!PageWriteback(page
)) {
3420 btrfs_err(BTRFS_I(inode
)->root
->fs_info
,
3421 "page %lu not writeback, cur %llu end %llu",
3422 page
->index
, cur
, end
);
3425 ret
= submit_extent_page(REQ_OP_WRITE
, write_flags
, tree
, wbc
,
3426 page
, sector
, iosize
, pg_offset
,
3428 end_bio_extent_writepage
,
3432 if (PageWriteback(page
))
3433 end_page_writeback(page
);
3437 pg_offset
+= iosize
;
3446 * the writepage semantics are similar to regular writepage. extent
3447 * records are inserted to lock ranges in the tree, and as dirty areas
3448 * are found, they are marked writeback. Then the lock bits are removed
3449 * and the end_io handler clears the writeback ranges
3451 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
3454 struct inode
*inode
= page
->mapping
->host
;
3455 struct extent_page_data
*epd
= data
;
3456 u64 start
= page_offset(page
);
3457 u64 page_end
= start
+ PAGE_SIZE
- 1;
3460 size_t pg_offset
= 0;
3461 loff_t i_size
= i_size_read(inode
);
3462 unsigned long end_index
= i_size
>> PAGE_SHIFT
;
3463 int write_flags
= 0;
3464 unsigned long nr_written
= 0;
3466 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3467 write_flags
= REQ_SYNC
;
3469 trace___extent_writepage(page
, inode
, wbc
);
3471 WARN_ON(!PageLocked(page
));
3473 ClearPageError(page
);
3475 pg_offset
= i_size
& (PAGE_SIZE
- 1);
3476 if (page
->index
> end_index
||
3477 (page
->index
== end_index
&& !pg_offset
)) {
3478 page
->mapping
->a_ops
->invalidatepage(page
, 0, PAGE_SIZE
);
3483 if (page
->index
== end_index
) {
3486 userpage
= kmap_atomic(page
);
3487 memset(userpage
+ pg_offset
, 0,
3488 PAGE_SIZE
- pg_offset
);
3489 kunmap_atomic(userpage
);
3490 flush_dcache_page(page
);
3495 set_page_extent_mapped(page
);
3497 ret
= writepage_delalloc(inode
, page
, wbc
, epd
, start
, &nr_written
);
3503 ret
= __extent_writepage_io(inode
, page
, wbc
, epd
,
3504 i_size
, nr_written
, write_flags
, &nr
);
3510 /* make sure the mapping tag for page dirty gets cleared */
3511 set_page_writeback(page
);
3512 end_page_writeback(page
);
3514 if (PageError(page
)) {
3515 ret
= ret
< 0 ? ret
: -EIO
;
3516 end_extent_writepage(page
, ret
, start
, page_end
);
3525 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3527 wait_on_bit_io(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
,
3528 TASK_UNINTERRUPTIBLE
);
3531 static noinline_for_stack
int
3532 lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3533 struct btrfs_fs_info
*fs_info
,
3534 struct extent_page_data
*epd
)
3536 unsigned long i
, num_pages
;
3540 if (!btrfs_try_tree_write_lock(eb
)) {
3542 flush_write_bio(epd
);
3543 btrfs_tree_lock(eb
);
3546 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3547 btrfs_tree_unlock(eb
);
3551 flush_write_bio(epd
);
3555 wait_on_extent_buffer_writeback(eb
);
3556 btrfs_tree_lock(eb
);
3557 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3559 btrfs_tree_unlock(eb
);
3564 * We need to do this to prevent races in people who check if the eb is
3565 * under IO since we can end up having no IO bits set for a short period
3568 spin_lock(&eb
->refs_lock
);
3569 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3570 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3571 spin_unlock(&eb
->refs_lock
);
3572 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3573 __percpu_counter_add(&fs_info
->dirty_metadata_bytes
,
3575 fs_info
->dirty_metadata_batch
);
3578 spin_unlock(&eb
->refs_lock
);
3581 btrfs_tree_unlock(eb
);
3586 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3587 for (i
= 0; i
< num_pages
; i
++) {
3588 struct page
*p
= eb
->pages
[i
];
3590 if (!trylock_page(p
)) {
3592 flush_write_bio(epd
);
3602 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3604 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3605 smp_mb__after_atomic();
3606 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3609 static void set_btree_ioerr(struct page
*page
)
3611 struct extent_buffer
*eb
= (struct extent_buffer
*)page
->private;
3614 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
))
3618 * If writeback for a btree extent that doesn't belong to a log tree
3619 * failed, increment the counter transaction->eb_write_errors.
3620 * We do this because while the transaction is running and before it's
3621 * committing (when we call filemap_fdata[write|wait]_range against
3622 * the btree inode), we might have
3623 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3624 * returns an error or an error happens during writeback, when we're
3625 * committing the transaction we wouldn't know about it, since the pages
3626 * can be no longer dirty nor marked anymore for writeback (if a
3627 * subsequent modification to the extent buffer didn't happen before the
3628 * transaction commit), which makes filemap_fdata[write|wait]_range not
3629 * able to find the pages tagged with SetPageError at transaction
3630 * commit time. So if this happens we must abort the transaction,
3631 * otherwise we commit a super block with btree roots that point to
3632 * btree nodes/leafs whose content on disk is invalid - either garbage
3633 * or the content of some node/leaf from a past generation that got
3634 * cowed or deleted and is no longer valid.
3636 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3637 * not be enough - we need to distinguish between log tree extents vs
3638 * non-log tree extents, and the next filemap_fdatawait_range() call
3639 * will catch and clear such errors in the mapping - and that call might
3640 * be from a log sync and not from a transaction commit. Also, checking
3641 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3642 * not done and would not be reliable - the eb might have been released
3643 * from memory and reading it back again means that flag would not be
3644 * set (since it's a runtime flag, not persisted on disk).
3646 * Using the flags below in the btree inode also makes us achieve the
3647 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3648 * writeback for all dirty pages and before filemap_fdatawait_range()
3649 * is called, the writeback for all dirty pages had already finished
3650 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3651 * filemap_fdatawait_range() would return success, as it could not know
3652 * that writeback errors happened (the pages were no longer tagged for
3655 switch (eb
->log_index
) {
3657 set_bit(BTRFS_FS_BTREE_ERR
, &eb
->fs_info
->flags
);
3660 set_bit(BTRFS_FS_LOG1_ERR
, &eb
->fs_info
->flags
);
3663 set_bit(BTRFS_FS_LOG2_ERR
, &eb
->fs_info
->flags
);
3666 BUG(); /* unexpected, logic error */
3670 static void end_bio_extent_buffer_writepage(struct bio
*bio
)
3672 struct bio_vec
*bvec
;
3673 struct extent_buffer
*eb
;
3676 ASSERT(!bio_flagged(bio
, BIO_CLONED
));
3677 bio_for_each_segment_all(bvec
, bio
, i
) {
3678 struct page
*page
= bvec
->bv_page
;
3680 eb
= (struct extent_buffer
*)page
->private;
3682 done
= atomic_dec_and_test(&eb
->io_pages
);
3684 if (bio
->bi_error
||
3685 test_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
)) {
3686 ClearPageUptodate(page
);
3687 set_btree_ioerr(page
);
3690 end_page_writeback(page
);
3695 end_extent_buffer_writeback(eb
);
3701 static noinline_for_stack
int write_one_eb(struct extent_buffer
*eb
,
3702 struct btrfs_fs_info
*fs_info
,
3703 struct writeback_control
*wbc
,
3704 struct extent_page_data
*epd
)
3706 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3707 struct extent_io_tree
*tree
= &BTRFS_I(fs_info
->btree_inode
)->io_tree
;
3708 u64 offset
= eb
->start
;
3710 unsigned long i
, num_pages
;
3711 unsigned long bio_flags
= 0;
3712 unsigned long start
, end
;
3713 int write_flags
= (epd
->sync_io
? REQ_SYNC
: 0) | REQ_META
;
3716 clear_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
);
3717 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3718 atomic_set(&eb
->io_pages
, num_pages
);
3719 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3720 bio_flags
= EXTENT_BIO_TREE_LOG
;
3722 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3723 nritems
= btrfs_header_nritems(eb
);
3724 if (btrfs_header_level(eb
) > 0) {
3725 end
= btrfs_node_key_ptr_offset(nritems
);
3727 memzero_extent_buffer(eb
, end
, eb
->len
- end
);
3731 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3733 start
= btrfs_item_nr_offset(nritems
);
3734 end
= BTRFS_LEAF_DATA_OFFSET
+ leaf_data_end(fs_info
, eb
);
3735 memzero_extent_buffer(eb
, start
, end
- start
);
3738 for (i
= 0; i
< num_pages
; i
++) {
3739 struct page
*p
= eb
->pages
[i
];
3741 clear_page_dirty_for_io(p
);
3742 set_page_writeback(p
);
3743 ret
= submit_extent_page(REQ_OP_WRITE
, write_flags
, tree
, wbc
,
3744 p
, offset
>> 9, PAGE_SIZE
, 0, bdev
,
3746 end_bio_extent_buffer_writepage
,
3747 0, epd
->bio_flags
, bio_flags
, false);
3748 epd
->bio_flags
= bio_flags
;
3751 if (PageWriteback(p
))
3752 end_page_writeback(p
);
3753 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3754 end_extent_buffer_writeback(eb
);
3758 offset
+= PAGE_SIZE
;
3759 update_nr_written(wbc
, 1);
3763 if (unlikely(ret
)) {
3764 for (; i
< num_pages
; i
++) {
3765 struct page
*p
= eb
->pages
[i
];
3766 clear_page_dirty_for_io(p
);
3774 int btree_write_cache_pages(struct address_space
*mapping
,
3775 struct writeback_control
*wbc
)
3777 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3778 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3779 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3780 struct extent_page_data epd
= {
3784 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3789 int nr_to_write_done
= 0;
3790 struct pagevec pvec
;
3793 pgoff_t end
; /* Inclusive */
3797 pagevec_init(&pvec
, 0);
3798 if (wbc
->range_cyclic
) {
3799 index
= mapping
->writeback_index
; /* Start from prev offset */
3802 index
= wbc
->range_start
>> PAGE_SHIFT
;
3803 end
= wbc
->range_end
>> PAGE_SHIFT
;
3806 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3807 tag
= PAGECACHE_TAG_TOWRITE
;
3809 tag
= PAGECACHE_TAG_DIRTY
;
3811 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3812 tag_pages_for_writeback(mapping
, index
, end
);
3813 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3814 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3815 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3819 for (i
= 0; i
< nr_pages
; i
++) {
3820 struct page
*page
= pvec
.pages
[i
];
3822 if (!PagePrivate(page
))
3825 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3830 spin_lock(&mapping
->private_lock
);
3831 if (!PagePrivate(page
)) {
3832 spin_unlock(&mapping
->private_lock
);
3836 eb
= (struct extent_buffer
*)page
->private;
3839 * Shouldn't happen and normally this would be a BUG_ON
3840 * but no sense in crashing the users box for something
3841 * we can survive anyway.
3844 spin_unlock(&mapping
->private_lock
);
3848 if (eb
== prev_eb
) {
3849 spin_unlock(&mapping
->private_lock
);
3853 ret
= atomic_inc_not_zero(&eb
->refs
);
3854 spin_unlock(&mapping
->private_lock
);
3859 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3861 free_extent_buffer(eb
);
3865 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3868 free_extent_buffer(eb
);
3871 free_extent_buffer(eb
);
3874 * the filesystem may choose to bump up nr_to_write.
3875 * We have to make sure to honor the new nr_to_write
3878 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3880 pagevec_release(&pvec
);
3883 if (!scanned
&& !done
) {
3885 * We hit the last page and there is more work to be done: wrap
3886 * back to the start of the file
3892 flush_write_bio(&epd
);
3897 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3898 * @mapping: address space structure to write
3899 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3900 * @writepage: function called for each page
3901 * @data: data passed to writepage function
3903 * If a page is already under I/O, write_cache_pages() skips it, even
3904 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3905 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3906 * and msync() need to guarantee that all the data which was dirty at the time
3907 * the call was made get new I/O started against them. If wbc->sync_mode is
3908 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3909 * existing IO to complete.
3911 static int extent_write_cache_pages(struct address_space
*mapping
,
3912 struct writeback_control
*wbc
,
3913 writepage_t writepage
, void *data
,
3914 void (*flush_fn
)(void *))
3916 struct inode
*inode
= mapping
->host
;
3919 int nr_to_write_done
= 0;
3920 struct pagevec pvec
;
3923 pgoff_t end
; /* Inclusive */
3925 int range_whole
= 0;
3930 * We have to hold onto the inode so that ordered extents can do their
3931 * work when the IO finishes. The alternative to this is failing to add
3932 * an ordered extent if the igrab() fails there and that is a huge pain
3933 * to deal with, so instead just hold onto the inode throughout the
3934 * writepages operation. If it fails here we are freeing up the inode
3935 * anyway and we'd rather not waste our time writing out stuff that is
3936 * going to be truncated anyway.
3941 pagevec_init(&pvec
, 0);
3942 if (wbc
->range_cyclic
) {
3943 index
= mapping
->writeback_index
; /* Start from prev offset */
3946 index
= wbc
->range_start
>> PAGE_SHIFT
;
3947 end
= wbc
->range_end
>> PAGE_SHIFT
;
3948 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
3952 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3953 tag
= PAGECACHE_TAG_TOWRITE
;
3955 tag
= PAGECACHE_TAG_DIRTY
;
3957 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3958 tag_pages_for_writeback(mapping
, index
, end
);
3960 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3961 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3962 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3966 for (i
= 0; i
< nr_pages
; i
++) {
3967 struct page
*page
= pvec
.pages
[i
];
3969 done_index
= page
->index
;
3971 * At this point we hold neither mapping->tree_lock nor
3972 * lock on the page itself: the page may be truncated or
3973 * invalidated (changing page->mapping to NULL), or even
3974 * swizzled back from swapper_space to tmpfs file
3977 if (!trylock_page(page
)) {
3982 if (unlikely(page
->mapping
!= mapping
)) {
3987 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3993 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
3994 if (PageWriteback(page
))
3996 wait_on_page_writeback(page
);
3999 if (PageWriteback(page
) ||
4000 !clear_page_dirty_for_io(page
)) {
4005 ret
= (*writepage
)(page
, wbc
, data
);
4007 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
4013 * done_index is set past this page,
4014 * so media errors will not choke
4015 * background writeout for the entire
4016 * file. This has consequences for
4017 * range_cyclic semantics (ie. it may
4018 * not be suitable for data integrity
4021 done_index
= page
->index
+ 1;
4027 * the filesystem may choose to bump up nr_to_write.
4028 * We have to make sure to honor the new nr_to_write
4031 nr_to_write_done
= wbc
->nr_to_write
<= 0;
4033 pagevec_release(&pvec
);
4036 if (!scanned
&& !done
) {
4038 * We hit the last page and there is more work to be done: wrap
4039 * back to the start of the file
4046 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 && range_whole
))
4047 mapping
->writeback_index
= done_index
;
4049 btrfs_add_delayed_iput(inode
);
4053 static void flush_epd_write_bio(struct extent_page_data
*epd
)
4058 bio_set_op_attrs(epd
->bio
, REQ_OP_WRITE
,
4059 epd
->sync_io
? REQ_SYNC
: 0);
4061 ret
= submit_one_bio(epd
->bio
, 0, epd
->bio_flags
);
4062 BUG_ON(ret
< 0); /* -ENOMEM */
4067 static noinline
void flush_write_bio(void *data
)
4069 struct extent_page_data
*epd
= data
;
4070 flush_epd_write_bio(epd
);
4073 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
4074 get_extent_t
*get_extent
,
4075 struct writeback_control
*wbc
)
4078 struct extent_page_data epd
= {
4081 .get_extent
= get_extent
,
4083 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
4087 ret
= __extent_writepage(page
, wbc
, &epd
);
4089 flush_epd_write_bio(&epd
);
4093 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
4094 u64 start
, u64 end
, get_extent_t
*get_extent
,
4098 struct address_space
*mapping
= inode
->i_mapping
;
4100 unsigned long nr_pages
= (end
- start
+ PAGE_SIZE
) >>
4103 struct extent_page_data epd
= {
4106 .get_extent
= get_extent
,
4108 .sync_io
= mode
== WB_SYNC_ALL
,
4111 struct writeback_control wbc_writepages
= {
4113 .nr_to_write
= nr_pages
* 2,
4114 .range_start
= start
,
4115 .range_end
= end
+ 1,
4118 while (start
<= end
) {
4119 page
= find_get_page(mapping
, start
>> PAGE_SHIFT
);
4120 if (clear_page_dirty_for_io(page
))
4121 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
4123 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
4124 tree
->ops
->writepage_end_io_hook(page
, start
,
4125 start
+ PAGE_SIZE
- 1,
4133 flush_epd_write_bio(&epd
);
4137 int extent_writepages(struct extent_io_tree
*tree
,
4138 struct address_space
*mapping
,
4139 get_extent_t
*get_extent
,
4140 struct writeback_control
*wbc
)
4143 struct extent_page_data epd
= {
4146 .get_extent
= get_extent
,
4148 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
4152 ret
= extent_write_cache_pages(mapping
, wbc
, __extent_writepage
, &epd
,
4154 flush_epd_write_bio(&epd
);
4158 int extent_readpages(struct extent_io_tree
*tree
,
4159 struct address_space
*mapping
,
4160 struct list_head
*pages
, unsigned nr_pages
,
4161 get_extent_t get_extent
)
4163 struct bio
*bio
= NULL
;
4165 unsigned long bio_flags
= 0;
4166 struct page
*pagepool
[16];
4168 struct extent_map
*em_cached
= NULL
;
4170 u64 prev_em_start
= (u64
)-1;
4172 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
4173 page
= list_entry(pages
->prev
, struct page
, lru
);
4175 prefetchw(&page
->flags
);
4176 list_del(&page
->lru
);
4177 if (add_to_page_cache_lru(page
, mapping
,
4179 readahead_gfp_mask(mapping
))) {
4184 pagepool
[nr
++] = page
;
4185 if (nr
< ARRAY_SIZE(pagepool
))
4187 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
4188 &bio
, 0, &bio_flags
, &prev_em_start
);
4192 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
4193 &bio
, 0, &bio_flags
, &prev_em_start
);
4196 free_extent_map(em_cached
);
4198 BUG_ON(!list_empty(pages
));
4200 return submit_one_bio(bio
, 0, bio_flags
);
4205 * basic invalidatepage code, this waits on any locked or writeback
4206 * ranges corresponding to the page, and then deletes any extent state
4207 * records from the tree
4209 int extent_invalidatepage(struct extent_io_tree
*tree
,
4210 struct page
*page
, unsigned long offset
)
4212 struct extent_state
*cached_state
= NULL
;
4213 u64 start
= page_offset(page
);
4214 u64 end
= start
+ PAGE_SIZE
- 1;
4215 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
4217 start
+= ALIGN(offset
, blocksize
);
4221 lock_extent_bits(tree
, start
, end
, &cached_state
);
4222 wait_on_page_writeback(page
);
4223 clear_extent_bit(tree
, start
, end
,
4224 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
4225 EXTENT_DO_ACCOUNTING
,
4226 1, 1, &cached_state
, GFP_NOFS
);
4231 * a helper for releasepage, this tests for areas of the page that
4232 * are locked or under IO and drops the related state bits if it is safe
4235 static int try_release_extent_state(struct extent_map_tree
*map
,
4236 struct extent_io_tree
*tree
,
4237 struct page
*page
, gfp_t mask
)
4239 u64 start
= page_offset(page
);
4240 u64 end
= start
+ PAGE_SIZE
- 1;
4243 if (test_range_bit(tree
, start
, end
,
4244 EXTENT_IOBITS
, 0, NULL
))
4248 * at this point we can safely clear everything except the
4249 * locked bit and the nodatasum bit
4251 ret
= clear_extent_bit(tree
, start
, end
,
4252 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
4255 /* if clear_extent_bit failed for enomem reasons,
4256 * we can't allow the release to continue.
4267 * a helper for releasepage. As long as there are no locked extents
4268 * in the range corresponding to the page, both state records and extent
4269 * map records are removed
4271 int try_release_extent_mapping(struct extent_map_tree
*map
,
4272 struct extent_io_tree
*tree
, struct page
*page
,
4275 struct extent_map
*em
;
4276 u64 start
= page_offset(page
);
4277 u64 end
= start
+ PAGE_SIZE
- 1;
4279 if (gfpflags_allow_blocking(mask
) &&
4280 page
->mapping
->host
->i_size
> SZ_16M
) {
4282 while (start
<= end
) {
4283 len
= end
- start
+ 1;
4284 write_lock(&map
->lock
);
4285 em
= lookup_extent_mapping(map
, start
, len
);
4287 write_unlock(&map
->lock
);
4290 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
4291 em
->start
!= start
) {
4292 write_unlock(&map
->lock
);
4293 free_extent_map(em
);
4296 if (!test_range_bit(tree
, em
->start
,
4297 extent_map_end(em
) - 1,
4298 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
4300 remove_extent_mapping(map
, em
);
4301 /* once for the rb tree */
4302 free_extent_map(em
);
4304 start
= extent_map_end(em
);
4305 write_unlock(&map
->lock
);
4308 free_extent_map(em
);
4311 return try_release_extent_state(map
, tree
, page
, mask
);
4315 * helper function for fiemap, which doesn't want to see any holes.
4316 * This maps until we find something past 'last'
4318 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
4321 get_extent_t
*get_extent
)
4323 u64 sectorsize
= btrfs_inode_sectorsize(inode
);
4324 struct extent_map
*em
;
4331 len
= last
- offset
;
4334 len
= ALIGN(len
, sectorsize
);
4335 em
= get_extent(BTRFS_I(inode
), NULL
, 0, offset
, len
, 0);
4336 if (IS_ERR_OR_NULL(em
))
4339 /* if this isn't a hole return it */
4340 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
4341 em
->block_start
!= EXTENT_MAP_HOLE
) {
4345 /* this is a hole, advance to the next extent */
4346 offset
= extent_map_end(em
);
4347 free_extent_map(em
);
4355 * To cache previous fiemap extent
4357 * Will be used for merging fiemap extent
4359 struct fiemap_cache
{
4368 * Helper to submit fiemap extent.
4370 * Will try to merge current fiemap extent specified by @offset, @phys,
4371 * @len and @flags with cached one.
4372 * And only when we fails to merge, cached one will be submitted as
4375 * Return value is the same as fiemap_fill_next_extent().
4377 static int emit_fiemap_extent(struct fiemap_extent_info
*fieinfo
,
4378 struct fiemap_cache
*cache
,
4379 u64 offset
, u64 phys
, u64 len
, u32 flags
)
4387 * Sanity check, extent_fiemap() should have ensured that new
4388 * fiemap extent won't overlap with cahced one.
4391 * NOTE: Physical address can overlap, due to compression
4393 if (cache
->offset
+ cache
->len
> offset
) {
4399 * Only merges fiemap extents if
4400 * 1) Their logical addresses are continuous
4402 * 2) Their physical addresses are continuous
4403 * So truly compressed (physical size smaller than logical size)
4404 * extents won't get merged with each other
4406 * 3) Share same flags except FIEMAP_EXTENT_LAST
4407 * So regular extent won't get merged with prealloc extent
4409 if (cache
->offset
+ cache
->len
== offset
&&
4410 cache
->phys
+ cache
->len
== phys
&&
4411 (cache
->flags
& ~FIEMAP_EXTENT_LAST
) ==
4412 (flags
& ~FIEMAP_EXTENT_LAST
)) {
4414 cache
->flags
|= flags
;
4415 goto try_submit_last
;
4418 /* Not mergeable, need to submit cached one */
4419 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
, cache
->phys
,
4420 cache
->len
, cache
->flags
);
4421 cache
->cached
= false;
4425 cache
->cached
= true;
4426 cache
->offset
= offset
;
4429 cache
->flags
= flags
;
4431 if (cache
->flags
& FIEMAP_EXTENT_LAST
) {
4432 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
,
4433 cache
->phys
, cache
->len
, cache
->flags
);
4434 cache
->cached
= false;
4440 * Emit last fiemap cache
4442 * The last fiemap cache may still be cached in the following case:
4444 * |<- Fiemap range ->|
4445 * |<------------ First extent ----------->|
4447 * In this case, the first extent range will be cached but not emitted.
4448 * So we must emit it before ending extent_fiemap().
4450 static int emit_last_fiemap_cache(struct btrfs_fs_info
*fs_info
,
4451 struct fiemap_extent_info
*fieinfo
,
4452 struct fiemap_cache
*cache
)
4459 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
, cache
->phys
,
4460 cache
->len
, cache
->flags
);
4461 cache
->cached
= false;
4467 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4468 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
4472 u64 max
= start
+ len
;
4476 u64 last_for_get_extent
= 0;
4478 u64 isize
= i_size_read(inode
);
4479 struct btrfs_key found_key
;
4480 struct extent_map
*em
= NULL
;
4481 struct extent_state
*cached_state
= NULL
;
4482 struct btrfs_path
*path
;
4483 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4484 struct fiemap_cache cache
= { 0 };
4493 path
= btrfs_alloc_path();
4496 path
->leave_spinning
= 1;
4498 start
= round_down(start
, btrfs_inode_sectorsize(inode
));
4499 len
= round_up(max
, btrfs_inode_sectorsize(inode
)) - start
;
4502 * lookup the last file extent. We're not using i_size here
4503 * because there might be preallocation past i_size
4505 ret
= btrfs_lookup_file_extent(NULL
, root
, path
,
4506 btrfs_ino(BTRFS_I(inode
)), -1, 0);
4508 btrfs_free_path(path
);
4517 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
4518 found_type
= found_key
.type
;
4520 /* No extents, but there might be delalloc bits */
4521 if (found_key
.objectid
!= btrfs_ino(BTRFS_I(inode
)) ||
4522 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
4523 /* have to trust i_size as the end */
4525 last_for_get_extent
= isize
;
4528 * remember the start of the last extent. There are a
4529 * bunch of different factors that go into the length of the
4530 * extent, so its much less complex to remember where it started
4532 last
= found_key
.offset
;
4533 last_for_get_extent
= last
+ 1;
4535 btrfs_release_path(path
);
4538 * we might have some extents allocated but more delalloc past those
4539 * extents. so, we trust isize unless the start of the last extent is
4544 last_for_get_extent
= isize
;
4547 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4550 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4560 u64 offset_in_extent
= 0;
4562 /* break if the extent we found is outside the range */
4563 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4567 * get_extent may return an extent that starts before our
4568 * requested range. We have to make sure the ranges
4569 * we return to fiemap always move forward and don't
4570 * overlap, so adjust the offsets here
4572 em_start
= max(em
->start
, off
);
4575 * record the offset from the start of the extent
4576 * for adjusting the disk offset below. Only do this if the
4577 * extent isn't compressed since our in ram offset may be past
4578 * what we have actually allocated on disk.
4580 if (!test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4581 offset_in_extent
= em_start
- em
->start
;
4582 em_end
= extent_map_end(em
);
4583 em_len
= em_end
- em_start
;
4588 * bump off for our next call to get_extent
4590 off
= extent_map_end(em
);
4594 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4596 flags
|= FIEMAP_EXTENT_LAST
;
4597 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4598 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4599 FIEMAP_EXTENT_NOT_ALIGNED
);
4600 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4601 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4602 FIEMAP_EXTENT_UNKNOWN
);
4603 } else if (fieinfo
->fi_extents_max
) {
4604 struct btrfs_trans_handle
*trans
;
4606 u64 bytenr
= em
->block_start
-
4607 (em
->start
- em
->orig_start
);
4609 disko
= em
->block_start
+ offset_in_extent
;
4612 * We need a trans handle to get delayed refs
4614 trans
= btrfs_join_transaction(root
);
4616 * It's OK if we can't start a trans we can still check
4623 * As btrfs supports shared space, this information
4624 * can be exported to userspace tools via
4625 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4626 * then we're just getting a count and we can skip the
4629 ret
= btrfs_check_shared(trans
, root
->fs_info
,
4631 btrfs_ino(BTRFS_I(inode
)), bytenr
);
4633 btrfs_end_transaction(trans
);
4637 flags
|= FIEMAP_EXTENT_SHARED
;
4640 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4641 flags
|= FIEMAP_EXTENT_ENCODED
;
4642 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
4643 flags
|= FIEMAP_EXTENT_UNWRITTEN
;
4645 free_extent_map(em
);
4647 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4648 (last
== (u64
)-1 && isize
<= em_end
)) {
4649 flags
|= FIEMAP_EXTENT_LAST
;
4653 /* now scan forward to see if this is really the last extent. */
4654 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4661 flags
|= FIEMAP_EXTENT_LAST
;
4664 ret
= emit_fiemap_extent(fieinfo
, &cache
, em_start
, disko
,
4674 ret
= emit_last_fiemap_cache(root
->fs_info
, fieinfo
, &cache
);
4675 free_extent_map(em
);
4677 btrfs_free_path(path
);
4678 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4679 &cached_state
, GFP_NOFS
);
4683 static void __free_extent_buffer(struct extent_buffer
*eb
)
4685 btrfs_leak_debug_del(&eb
->leak_list
);
4686 kmem_cache_free(extent_buffer_cache
, eb
);
4689 int extent_buffer_under_io(struct extent_buffer
*eb
)
4691 return (atomic_read(&eb
->io_pages
) ||
4692 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4693 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4697 * Helper for releasing extent buffer page.
4699 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
)
4701 unsigned long index
;
4703 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4705 BUG_ON(extent_buffer_under_io(eb
));
4707 index
= num_extent_pages(eb
->start
, eb
->len
);
4713 page
= eb
->pages
[index
];
4717 spin_lock(&page
->mapping
->private_lock
);
4719 * We do this since we'll remove the pages after we've
4720 * removed the eb from the radix tree, so we could race
4721 * and have this page now attached to the new eb. So
4722 * only clear page_private if it's still connected to
4725 if (PagePrivate(page
) &&
4726 page
->private == (unsigned long)eb
) {
4727 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4728 BUG_ON(PageDirty(page
));
4729 BUG_ON(PageWriteback(page
));
4731 * We need to make sure we haven't be attached
4734 ClearPagePrivate(page
);
4735 set_page_private(page
, 0);
4736 /* One for the page private */
4741 spin_unlock(&page
->mapping
->private_lock
);
4743 /* One for when we allocated the page */
4745 } while (index
!= 0);
4749 * Helper for releasing the extent buffer.
4751 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4753 btrfs_release_extent_buffer_page(eb
);
4754 __free_extent_buffer(eb
);
4757 static struct extent_buffer
*
4758 __alloc_extent_buffer(struct btrfs_fs_info
*fs_info
, u64 start
,
4761 struct extent_buffer
*eb
= NULL
;
4763 eb
= kmem_cache_zalloc(extent_buffer_cache
, GFP_NOFS
|__GFP_NOFAIL
);
4766 eb
->fs_info
= fs_info
;
4768 rwlock_init(&eb
->lock
);
4769 atomic_set(&eb
->write_locks
, 0);
4770 atomic_set(&eb
->read_locks
, 0);
4771 atomic_set(&eb
->blocking_readers
, 0);
4772 atomic_set(&eb
->blocking_writers
, 0);
4773 atomic_set(&eb
->spinning_readers
, 0);
4774 atomic_set(&eb
->spinning_writers
, 0);
4775 eb
->lock_nested
= 0;
4776 init_waitqueue_head(&eb
->write_lock_wq
);
4777 init_waitqueue_head(&eb
->read_lock_wq
);
4779 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4781 spin_lock_init(&eb
->refs_lock
);
4782 atomic_set(&eb
->refs
, 1);
4783 atomic_set(&eb
->io_pages
, 0);
4786 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4788 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4789 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4790 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4795 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4799 struct extent_buffer
*new;
4800 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4802 new = __alloc_extent_buffer(src
->fs_info
, src
->start
, src
->len
);
4806 for (i
= 0; i
< num_pages
; i
++) {
4807 p
= alloc_page(GFP_NOFS
);
4809 btrfs_release_extent_buffer(new);
4812 attach_extent_buffer_page(new, p
);
4813 WARN_ON(PageDirty(p
));
4816 copy_page(page_address(p
), page_address(src
->pages
[i
]));
4819 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4820 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4825 struct extent_buffer
*__alloc_dummy_extent_buffer(struct btrfs_fs_info
*fs_info
,
4826 u64 start
, unsigned long len
)
4828 struct extent_buffer
*eb
;
4829 unsigned long num_pages
;
4832 num_pages
= num_extent_pages(start
, len
);
4834 eb
= __alloc_extent_buffer(fs_info
, start
, len
);
4838 for (i
= 0; i
< num_pages
; i
++) {
4839 eb
->pages
[i
] = alloc_page(GFP_NOFS
);
4843 set_extent_buffer_uptodate(eb
);
4844 btrfs_set_header_nritems(eb
, 0);
4845 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4850 __free_page(eb
->pages
[i
- 1]);
4851 __free_extent_buffer(eb
);
4855 struct extent_buffer
*alloc_dummy_extent_buffer(struct btrfs_fs_info
*fs_info
,
4858 return __alloc_dummy_extent_buffer(fs_info
, start
, fs_info
->nodesize
);
4861 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4864 /* the ref bit is tricky. We have to make sure it is set
4865 * if we have the buffer dirty. Otherwise the
4866 * code to free a buffer can end up dropping a dirty
4869 * Once the ref bit is set, it won't go away while the
4870 * buffer is dirty or in writeback, and it also won't
4871 * go away while we have the reference count on the
4874 * We can't just set the ref bit without bumping the
4875 * ref on the eb because free_extent_buffer might
4876 * see the ref bit and try to clear it. If this happens
4877 * free_extent_buffer might end up dropping our original
4878 * ref by mistake and freeing the page before we are able
4879 * to add one more ref.
4881 * So bump the ref count first, then set the bit. If someone
4882 * beat us to it, drop the ref we added.
4884 refs
= atomic_read(&eb
->refs
);
4885 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4888 spin_lock(&eb
->refs_lock
);
4889 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4890 atomic_inc(&eb
->refs
);
4891 spin_unlock(&eb
->refs_lock
);
4894 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
,
4895 struct page
*accessed
)
4897 unsigned long num_pages
, i
;
4899 check_buffer_tree_ref(eb
);
4901 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4902 for (i
= 0; i
< num_pages
; i
++) {
4903 struct page
*p
= eb
->pages
[i
];
4906 mark_page_accessed(p
);
4910 struct extent_buffer
*find_extent_buffer(struct btrfs_fs_info
*fs_info
,
4913 struct extent_buffer
*eb
;
4916 eb
= radix_tree_lookup(&fs_info
->buffer_radix
,
4917 start
>> PAGE_SHIFT
);
4918 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4921 * Lock our eb's refs_lock to avoid races with
4922 * free_extent_buffer. When we get our eb it might be flagged
4923 * with EXTENT_BUFFER_STALE and another task running
4924 * free_extent_buffer might have seen that flag set,
4925 * eb->refs == 2, that the buffer isn't under IO (dirty and
4926 * writeback flags not set) and it's still in the tree (flag
4927 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4928 * of decrementing the extent buffer's reference count twice.
4929 * So here we could race and increment the eb's reference count,
4930 * clear its stale flag, mark it as dirty and drop our reference
4931 * before the other task finishes executing free_extent_buffer,
4932 * which would later result in an attempt to free an extent
4933 * buffer that is dirty.
4935 if (test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
)) {
4936 spin_lock(&eb
->refs_lock
);
4937 spin_unlock(&eb
->refs_lock
);
4939 mark_extent_buffer_accessed(eb
, NULL
);
4947 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4948 struct extent_buffer
*alloc_test_extent_buffer(struct btrfs_fs_info
*fs_info
,
4951 struct extent_buffer
*eb
, *exists
= NULL
;
4954 eb
= find_extent_buffer(fs_info
, start
);
4957 eb
= alloc_dummy_extent_buffer(fs_info
, start
);
4960 eb
->fs_info
= fs_info
;
4962 ret
= radix_tree_preload(GFP_NOFS
);
4965 spin_lock(&fs_info
->buffer_lock
);
4966 ret
= radix_tree_insert(&fs_info
->buffer_radix
,
4967 start
>> PAGE_SHIFT
, eb
);
4968 spin_unlock(&fs_info
->buffer_lock
);
4969 radix_tree_preload_end();
4970 if (ret
== -EEXIST
) {
4971 exists
= find_extent_buffer(fs_info
, start
);
4977 check_buffer_tree_ref(eb
);
4978 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
4981 * We will free dummy extent buffer's if they come into
4982 * free_extent_buffer with a ref count of 2, but if we are using this we
4983 * want the buffers to stay in memory until we're done with them, so
4984 * bump the ref count again.
4986 atomic_inc(&eb
->refs
);
4989 btrfs_release_extent_buffer(eb
);
4994 struct extent_buffer
*alloc_extent_buffer(struct btrfs_fs_info
*fs_info
,
4997 unsigned long len
= fs_info
->nodesize
;
4998 unsigned long num_pages
= num_extent_pages(start
, len
);
5000 unsigned long index
= start
>> PAGE_SHIFT
;
5001 struct extent_buffer
*eb
;
5002 struct extent_buffer
*exists
= NULL
;
5004 struct address_space
*mapping
= fs_info
->btree_inode
->i_mapping
;
5008 if (!IS_ALIGNED(start
, fs_info
->sectorsize
)) {
5009 btrfs_err(fs_info
, "bad tree block start %llu", start
);
5010 return ERR_PTR(-EINVAL
);
5013 eb
= find_extent_buffer(fs_info
, start
);
5017 eb
= __alloc_extent_buffer(fs_info
, start
, len
);
5019 return ERR_PTR(-ENOMEM
);
5021 for (i
= 0; i
< num_pages
; i
++, index
++) {
5022 p
= find_or_create_page(mapping
, index
, GFP_NOFS
|__GFP_NOFAIL
);
5024 exists
= ERR_PTR(-ENOMEM
);
5028 spin_lock(&mapping
->private_lock
);
5029 if (PagePrivate(p
)) {
5031 * We could have already allocated an eb for this page
5032 * and attached one so lets see if we can get a ref on
5033 * the existing eb, and if we can we know it's good and
5034 * we can just return that one, else we know we can just
5035 * overwrite page->private.
5037 exists
= (struct extent_buffer
*)p
->private;
5038 if (atomic_inc_not_zero(&exists
->refs
)) {
5039 spin_unlock(&mapping
->private_lock
);
5042 mark_extent_buffer_accessed(exists
, p
);
5048 * Do this so attach doesn't complain and we need to
5049 * drop the ref the old guy had.
5051 ClearPagePrivate(p
);
5052 WARN_ON(PageDirty(p
));
5055 attach_extent_buffer_page(eb
, p
);
5056 spin_unlock(&mapping
->private_lock
);
5057 WARN_ON(PageDirty(p
));
5059 if (!PageUptodate(p
))
5063 * see below about how we avoid a nasty race with release page
5064 * and why we unlock later
5068 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5070 ret
= radix_tree_preload(GFP_NOFS
);
5072 exists
= ERR_PTR(ret
);
5076 spin_lock(&fs_info
->buffer_lock
);
5077 ret
= radix_tree_insert(&fs_info
->buffer_radix
,
5078 start
>> PAGE_SHIFT
, eb
);
5079 spin_unlock(&fs_info
->buffer_lock
);
5080 radix_tree_preload_end();
5081 if (ret
== -EEXIST
) {
5082 exists
= find_extent_buffer(fs_info
, start
);
5088 /* add one reference for the tree */
5089 check_buffer_tree_ref(eb
);
5090 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
5093 * there is a race where release page may have
5094 * tried to find this extent buffer in the radix
5095 * but failed. It will tell the VM it is safe to
5096 * reclaim the, and it will clear the page private bit.
5097 * We must make sure to set the page private bit properly
5098 * after the extent buffer is in the radix tree so
5099 * it doesn't get lost
5101 SetPageChecked(eb
->pages
[0]);
5102 for (i
= 1; i
< num_pages
; i
++) {
5104 ClearPageChecked(p
);
5107 unlock_page(eb
->pages
[0]);
5111 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
5112 for (i
= 0; i
< num_pages
; i
++) {
5114 unlock_page(eb
->pages
[i
]);
5117 btrfs_release_extent_buffer(eb
);
5121 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
5123 struct extent_buffer
*eb
=
5124 container_of(head
, struct extent_buffer
, rcu_head
);
5126 __free_extent_buffer(eb
);
5129 /* Expects to have eb->eb_lock already held */
5130 static int release_extent_buffer(struct extent_buffer
*eb
)
5132 WARN_ON(atomic_read(&eb
->refs
) == 0);
5133 if (atomic_dec_and_test(&eb
->refs
)) {
5134 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
)) {
5135 struct btrfs_fs_info
*fs_info
= eb
->fs_info
;
5137 spin_unlock(&eb
->refs_lock
);
5139 spin_lock(&fs_info
->buffer_lock
);
5140 radix_tree_delete(&fs_info
->buffer_radix
,
5141 eb
->start
>> PAGE_SHIFT
);
5142 spin_unlock(&fs_info
->buffer_lock
);
5144 spin_unlock(&eb
->refs_lock
);
5147 /* Should be safe to release our pages at this point */
5148 btrfs_release_extent_buffer_page(eb
);
5149 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5150 if (unlikely(test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))) {
5151 __free_extent_buffer(eb
);
5155 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
5158 spin_unlock(&eb
->refs_lock
);
5163 void free_extent_buffer(struct extent_buffer
*eb
)
5171 refs
= atomic_read(&eb
->refs
);
5174 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
5179 spin_lock(&eb
->refs_lock
);
5180 if (atomic_read(&eb
->refs
) == 2 &&
5181 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
5182 atomic_dec(&eb
->refs
);
5184 if (atomic_read(&eb
->refs
) == 2 &&
5185 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
5186 !extent_buffer_under_io(eb
) &&
5187 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
5188 atomic_dec(&eb
->refs
);
5191 * I know this is terrible, but it's temporary until we stop tracking
5192 * the uptodate bits and such for the extent buffers.
5194 release_extent_buffer(eb
);
5197 void free_extent_buffer_stale(struct extent_buffer
*eb
)
5202 spin_lock(&eb
->refs_lock
);
5203 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
5205 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
5206 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
5207 atomic_dec(&eb
->refs
);
5208 release_extent_buffer(eb
);
5211 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
5214 unsigned long num_pages
;
5217 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5219 for (i
= 0; i
< num_pages
; i
++) {
5220 page
= eb
->pages
[i
];
5221 if (!PageDirty(page
))
5225 WARN_ON(!PagePrivate(page
));
5227 clear_page_dirty_for_io(page
);
5228 spin_lock_irq(&page
->mapping
->tree_lock
);
5229 if (!PageDirty(page
)) {
5230 radix_tree_tag_clear(&page
->mapping
->page_tree
,
5232 PAGECACHE_TAG_DIRTY
);
5234 spin_unlock_irq(&page
->mapping
->tree_lock
);
5235 ClearPageError(page
);
5238 WARN_ON(atomic_read(&eb
->refs
) == 0);
5241 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
5244 unsigned long num_pages
;
5247 check_buffer_tree_ref(eb
);
5249 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
5251 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5252 WARN_ON(atomic_read(&eb
->refs
) == 0);
5253 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
5255 for (i
= 0; i
< num_pages
; i
++)
5256 set_page_dirty(eb
->pages
[i
]);
5260 void clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
5264 unsigned long num_pages
;
5266 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5267 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5268 for (i
= 0; i
< num_pages
; i
++) {
5269 page
= eb
->pages
[i
];
5271 ClearPageUptodate(page
);
5275 void set_extent_buffer_uptodate(struct extent_buffer
*eb
)
5279 unsigned long num_pages
;
5281 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5282 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5283 for (i
= 0; i
< num_pages
; i
++) {
5284 page
= eb
->pages
[i
];
5285 SetPageUptodate(page
);
5289 int extent_buffer_uptodate(struct extent_buffer
*eb
)
5291 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5294 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
5295 struct extent_buffer
*eb
, int wait
,
5296 get_extent_t
*get_extent
, int mirror_num
)
5302 int locked_pages
= 0;
5303 int all_uptodate
= 1;
5304 unsigned long num_pages
;
5305 unsigned long num_reads
= 0;
5306 struct bio
*bio
= NULL
;
5307 unsigned long bio_flags
= 0;
5309 if (test_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 if (wait
== WAIT_NONE
) {
5316 if (!trylock_page(page
))
5324 * We need to firstly lock all pages to make sure that
5325 * the uptodate bit of our pages won't be affected by
5326 * clear_extent_buffer_uptodate().
5328 for (i
= 0; i
< num_pages
; i
++) {
5329 page
= eb
->pages
[i
];
5330 if (!PageUptodate(page
)) {
5337 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5341 clear_bit(EXTENT_BUFFER_READ_ERR
, &eb
->bflags
);
5342 eb
->read_mirror
= 0;
5343 atomic_set(&eb
->io_pages
, num_reads
);
5344 for (i
= 0; i
< num_pages
; i
++) {
5345 page
= eb
->pages
[i
];
5347 if (!PageUptodate(page
)) {
5349 atomic_dec(&eb
->io_pages
);
5354 ClearPageError(page
);
5355 err
= __extent_read_full_page(tree
, page
,
5357 mirror_num
, &bio_flags
,
5362 * We use &bio in above __extent_read_full_page,
5363 * so we ensure that if it returns error, the
5364 * current page fails to add itself to bio and
5365 * it's been unlocked.
5367 * We must dec io_pages by ourselves.
5369 atomic_dec(&eb
->io_pages
);
5377 err
= submit_one_bio(bio
, mirror_num
, bio_flags
);
5382 if (ret
|| wait
!= WAIT_COMPLETE
)
5385 for (i
= 0; i
< num_pages
; i
++) {
5386 page
= eb
->pages
[i
];
5387 wait_on_page_locked(page
);
5388 if (!PageUptodate(page
))
5395 while (locked_pages
> 0) {
5397 page
= eb
->pages
[locked_pages
];
5403 void read_extent_buffer(struct extent_buffer
*eb
, void *dstv
,
5404 unsigned long start
,
5411 char *dst
= (char *)dstv
;
5412 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5413 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5415 WARN_ON(start
> eb
->len
);
5416 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5418 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5421 page
= eb
->pages
[i
];
5423 cur
= min(len
, (PAGE_SIZE
- offset
));
5424 kaddr
= page_address(page
);
5425 memcpy(dst
, kaddr
+ offset
, cur
);
5434 int read_extent_buffer_to_user(struct extent_buffer
*eb
, void __user
*dstv
,
5435 unsigned long start
,
5442 char __user
*dst
= (char __user
*)dstv
;
5443 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5444 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5447 WARN_ON(start
> eb
->len
);
5448 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5450 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5453 page
= eb
->pages
[i
];
5455 cur
= min(len
, (PAGE_SIZE
- offset
));
5456 kaddr
= page_address(page
);
5457 if (copy_to_user(dst
, kaddr
+ offset
, cur
)) {
5472 * return 0 if the item is found within a page.
5473 * return 1 if the item spans two pages.
5474 * return -EINVAL otherwise.
5476 int map_private_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
5477 unsigned long min_len
, char **map
,
5478 unsigned long *map_start
,
5479 unsigned long *map_len
)
5481 size_t offset
= start
& (PAGE_SIZE
- 1);
5484 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5485 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5486 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
5493 offset
= start_offset
;
5497 *map_start
= ((u64
)i
<< PAGE_SHIFT
) - start_offset
;
5500 if (start
+ min_len
> eb
->len
) {
5501 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5502 eb
->start
, eb
->len
, start
, min_len
);
5507 kaddr
= page_address(p
);
5508 *map
= kaddr
+ offset
;
5509 *map_len
= PAGE_SIZE
- offset
;
5513 int memcmp_extent_buffer(struct extent_buffer
*eb
, const void *ptrv
,
5514 unsigned long start
,
5521 char *ptr
= (char *)ptrv
;
5522 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5523 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5526 WARN_ON(start
> eb
->len
);
5527 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5529 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5532 page
= eb
->pages
[i
];
5534 cur
= min(len
, (PAGE_SIZE
- offset
));
5536 kaddr
= page_address(page
);
5537 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
5549 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer
*eb
,
5554 WARN_ON(!PageUptodate(eb
->pages
[0]));
5555 kaddr
= page_address(eb
->pages
[0]);
5556 memcpy(kaddr
+ offsetof(struct btrfs_header
, chunk_tree_uuid
), srcv
,
5560 void write_extent_buffer_fsid(struct extent_buffer
*eb
, const void *srcv
)
5564 WARN_ON(!PageUptodate(eb
->pages
[0]));
5565 kaddr
= page_address(eb
->pages
[0]);
5566 memcpy(kaddr
+ offsetof(struct btrfs_header
, fsid
), srcv
,
5570 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
5571 unsigned long start
, unsigned long len
)
5577 char *src
= (char *)srcv
;
5578 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5579 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5581 WARN_ON(start
> eb
->len
);
5582 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5584 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5587 page
= eb
->pages
[i
];
5588 WARN_ON(!PageUptodate(page
));
5590 cur
= min(len
, PAGE_SIZE
- offset
);
5591 kaddr
= page_address(page
);
5592 memcpy(kaddr
+ offset
, src
, cur
);
5601 void memzero_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
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 memset(kaddr
+ offset
, 0, cur
);
5630 void copy_extent_buffer_full(struct extent_buffer
*dst
,
5631 struct extent_buffer
*src
)
5636 ASSERT(dst
->len
== src
->len
);
5638 num_pages
= num_extent_pages(dst
->start
, dst
->len
);
5639 for (i
= 0; i
< num_pages
; i
++)
5640 copy_page(page_address(dst
->pages
[i
]),
5641 page_address(src
->pages
[i
]));
5644 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
5645 unsigned long dst_offset
, unsigned long src_offset
,
5648 u64 dst_len
= dst
->len
;
5653 size_t start_offset
= dst
->start
& ((u64
)PAGE_SIZE
- 1);
5654 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_SHIFT
;
5656 WARN_ON(src
->len
!= dst_len
);
5658 offset
= (start_offset
+ dst_offset
) &
5662 page
= dst
->pages
[i
];
5663 WARN_ON(!PageUptodate(page
));
5665 cur
= min(len
, (unsigned long)(PAGE_SIZE
- offset
));
5667 kaddr
= page_address(page
);
5668 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
5677 void le_bitmap_set(u8
*map
, unsigned int start
, int len
)
5679 u8
*p
= map
+ BIT_BYTE(start
);
5680 const unsigned int size
= start
+ len
;
5681 int bits_to_set
= BITS_PER_BYTE
- (start
% BITS_PER_BYTE
);
5682 u8 mask_to_set
= BITMAP_FIRST_BYTE_MASK(start
);
5684 while (len
- bits_to_set
>= 0) {
5687 bits_to_set
= BITS_PER_BYTE
;
5692 mask_to_set
&= BITMAP_LAST_BYTE_MASK(size
);
5697 void le_bitmap_clear(u8
*map
, unsigned int start
, int len
)
5699 u8
*p
= map
+ BIT_BYTE(start
);
5700 const unsigned int size
= start
+ len
;
5701 int bits_to_clear
= BITS_PER_BYTE
- (start
% BITS_PER_BYTE
);
5702 u8 mask_to_clear
= BITMAP_FIRST_BYTE_MASK(start
);
5704 while (len
- bits_to_clear
>= 0) {
5705 *p
&= ~mask_to_clear
;
5706 len
-= bits_to_clear
;
5707 bits_to_clear
= BITS_PER_BYTE
;
5712 mask_to_clear
&= BITMAP_LAST_BYTE_MASK(size
);
5713 *p
&= ~mask_to_clear
;
5718 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5720 * @eb: the extent buffer
5721 * @start: offset of the bitmap item in the extent buffer
5723 * @page_index: return index of the page in the extent buffer that contains the
5725 * @page_offset: return offset into the page given by page_index
5727 * This helper hides the ugliness of finding the byte in an extent buffer which
5728 * contains a given bit.
5730 static inline void eb_bitmap_offset(struct extent_buffer
*eb
,
5731 unsigned long start
, unsigned long nr
,
5732 unsigned long *page_index
,
5733 size_t *page_offset
)
5735 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5736 size_t byte_offset
= BIT_BYTE(nr
);
5740 * The byte we want is the offset of the extent buffer + the offset of
5741 * the bitmap item in the extent buffer + the offset of the byte in the
5744 offset
= start_offset
+ start
+ byte_offset
;
5746 *page_index
= offset
>> PAGE_SHIFT
;
5747 *page_offset
= offset
& (PAGE_SIZE
- 1);
5751 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5752 * @eb: the extent buffer
5753 * @start: offset of the bitmap item in the extent buffer
5754 * @nr: bit number to test
5756 int extent_buffer_test_bit(struct extent_buffer
*eb
, unsigned long start
,
5764 eb_bitmap_offset(eb
, start
, nr
, &i
, &offset
);
5765 page
= eb
->pages
[i
];
5766 WARN_ON(!PageUptodate(page
));
5767 kaddr
= page_address(page
);
5768 return 1U & (kaddr
[offset
] >> (nr
& (BITS_PER_BYTE
- 1)));
5772 * extent_buffer_bitmap_set - set an area of a bitmap
5773 * @eb: the extent buffer
5774 * @start: offset of the bitmap item in the extent buffer
5775 * @pos: bit number of the first bit
5776 * @len: number of bits to set
5778 void extent_buffer_bitmap_set(struct extent_buffer
*eb
, unsigned long start
,
5779 unsigned long pos
, unsigned long len
)
5785 const unsigned int size
= pos
+ len
;
5786 int bits_to_set
= BITS_PER_BYTE
- (pos
% BITS_PER_BYTE
);
5787 u8 mask_to_set
= BITMAP_FIRST_BYTE_MASK(pos
);
5789 eb_bitmap_offset(eb
, start
, pos
, &i
, &offset
);
5790 page
= eb
->pages
[i
];
5791 WARN_ON(!PageUptodate(page
));
5792 kaddr
= page_address(page
);
5794 while (len
>= bits_to_set
) {
5795 kaddr
[offset
] |= mask_to_set
;
5797 bits_to_set
= BITS_PER_BYTE
;
5799 if (++offset
>= PAGE_SIZE
&& len
> 0) {
5801 page
= eb
->pages
[++i
];
5802 WARN_ON(!PageUptodate(page
));
5803 kaddr
= page_address(page
);
5807 mask_to_set
&= BITMAP_LAST_BYTE_MASK(size
);
5808 kaddr
[offset
] |= mask_to_set
;
5814 * extent_buffer_bitmap_clear - clear an area of a bitmap
5815 * @eb: the extent buffer
5816 * @start: offset of the bitmap item in the extent buffer
5817 * @pos: bit number of the first bit
5818 * @len: number of bits to clear
5820 void extent_buffer_bitmap_clear(struct extent_buffer
*eb
, unsigned long start
,
5821 unsigned long pos
, unsigned long len
)
5827 const unsigned int size
= pos
+ len
;
5828 int bits_to_clear
= BITS_PER_BYTE
- (pos
% BITS_PER_BYTE
);
5829 u8 mask_to_clear
= BITMAP_FIRST_BYTE_MASK(pos
);
5831 eb_bitmap_offset(eb
, start
, pos
, &i
, &offset
);
5832 page
= eb
->pages
[i
];
5833 WARN_ON(!PageUptodate(page
));
5834 kaddr
= page_address(page
);
5836 while (len
>= bits_to_clear
) {
5837 kaddr
[offset
] &= ~mask_to_clear
;
5838 len
-= bits_to_clear
;
5839 bits_to_clear
= BITS_PER_BYTE
;
5841 if (++offset
>= PAGE_SIZE
&& len
> 0) {
5843 page
= eb
->pages
[++i
];
5844 WARN_ON(!PageUptodate(page
));
5845 kaddr
= page_address(page
);
5849 mask_to_clear
&= BITMAP_LAST_BYTE_MASK(size
);
5850 kaddr
[offset
] &= ~mask_to_clear
;
5854 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
5856 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
5857 return distance
< len
;
5860 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
5861 unsigned long dst_off
, unsigned long src_off
,
5864 char *dst_kaddr
= page_address(dst_page
);
5866 int must_memmove
= 0;
5868 if (dst_page
!= src_page
) {
5869 src_kaddr
= page_address(src_page
);
5871 src_kaddr
= dst_kaddr
;
5872 if (areas_overlap(src_off
, dst_off
, len
))
5877 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5879 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5882 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5883 unsigned long src_offset
, unsigned long len
)
5885 struct btrfs_fs_info
*fs_info
= dst
->fs_info
;
5887 size_t dst_off_in_page
;
5888 size_t src_off_in_page
;
5889 size_t start_offset
= dst
->start
& ((u64
)PAGE_SIZE
- 1);
5890 unsigned long dst_i
;
5891 unsigned long src_i
;
5893 if (src_offset
+ len
> dst
->len
) {
5895 "memmove bogus src_offset %lu move len %lu dst len %lu",
5896 src_offset
, len
, dst
->len
);
5899 if (dst_offset
+ len
> dst
->len
) {
5901 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5902 dst_offset
, len
, dst
->len
);
5907 dst_off_in_page
= (start_offset
+ dst_offset
) &
5909 src_off_in_page
= (start_offset
+ src_offset
) &
5912 dst_i
= (start_offset
+ dst_offset
) >> PAGE_SHIFT
;
5913 src_i
= (start_offset
+ src_offset
) >> PAGE_SHIFT
;
5915 cur
= min(len
, (unsigned long)(PAGE_SIZE
-
5917 cur
= min_t(unsigned long, cur
,
5918 (unsigned long)(PAGE_SIZE
- dst_off_in_page
));
5920 copy_pages(dst
->pages
[dst_i
], dst
->pages
[src_i
],
5921 dst_off_in_page
, src_off_in_page
, cur
);
5929 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5930 unsigned long src_offset
, unsigned long len
)
5932 struct btrfs_fs_info
*fs_info
= dst
->fs_info
;
5934 size_t dst_off_in_page
;
5935 size_t src_off_in_page
;
5936 unsigned long dst_end
= dst_offset
+ len
- 1;
5937 unsigned long src_end
= src_offset
+ len
- 1;
5938 size_t start_offset
= dst
->start
& ((u64
)PAGE_SIZE
- 1);
5939 unsigned long dst_i
;
5940 unsigned long src_i
;
5942 if (src_offset
+ len
> dst
->len
) {
5944 "memmove bogus src_offset %lu move len %lu len %lu",
5945 src_offset
, len
, dst
->len
);
5948 if (dst_offset
+ len
> dst
->len
) {
5950 "memmove bogus dst_offset %lu move len %lu len %lu",
5951 dst_offset
, len
, dst
->len
);
5954 if (dst_offset
< src_offset
) {
5955 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5959 dst_i
= (start_offset
+ dst_end
) >> PAGE_SHIFT
;
5960 src_i
= (start_offset
+ src_end
) >> PAGE_SHIFT
;
5962 dst_off_in_page
= (start_offset
+ dst_end
) &
5964 src_off_in_page
= (start_offset
+ src_end
) &
5967 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5968 cur
= min(cur
, dst_off_in_page
+ 1);
5969 copy_pages(dst
->pages
[dst_i
], dst
->pages
[src_i
],
5970 dst_off_in_page
- cur
+ 1,
5971 src_off_in_page
- cur
+ 1, cur
);
5979 int try_release_extent_buffer(struct page
*page
)
5981 struct extent_buffer
*eb
;
5984 * We need to make sure nobody is attaching this page to an eb right
5987 spin_lock(&page
->mapping
->private_lock
);
5988 if (!PagePrivate(page
)) {
5989 spin_unlock(&page
->mapping
->private_lock
);
5993 eb
= (struct extent_buffer
*)page
->private;
5997 * This is a little awful but should be ok, we need to make sure that
5998 * the eb doesn't disappear out from under us while we're looking at
6001 spin_lock(&eb
->refs_lock
);
6002 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
6003 spin_unlock(&eb
->refs_lock
);
6004 spin_unlock(&page
->mapping
->private_lock
);
6007 spin_unlock(&page
->mapping
->private_lock
);
6010 * If tree ref isn't set then we know the ref on this eb is a real ref,
6011 * so just return, this page will likely be freed soon anyway.
6013 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
6014 spin_unlock(&eb
->refs_lock
);
6018 return release_extent_buffer(eb
);