1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bitops.h>
3 #include <linux/slab.h>
6 #include <linux/pagemap.h>
7 #include <linux/page-flags.h>
8 #include <linux/spinlock.h>
9 #include <linux/blkdev.h>
10 #include <linux/swap.h>
11 #include <linux/writeback.h>
12 #include <linux/pagevec.h>
13 #include <linux/prefetch.h>
14 #include <linux/cleancache.h>
15 #include "extent_io.h"
16 #include "extent_map.h"
18 #include "btrfs_inode.h"
20 #include "check-integrity.h"
22 #include "rcu-string.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
),
170 goto free_buffer_cache
;
172 if (bioset_integrity_create(btrfs_bioset
, BIO_POOL_SIZE
))
178 bioset_free(btrfs_bioset
);
182 kmem_cache_destroy(extent_buffer_cache
);
183 extent_buffer_cache
= NULL
;
186 kmem_cache_destroy(extent_state_cache
);
187 extent_state_cache
= NULL
;
191 void extent_io_exit(void)
193 btrfs_leak_debug_check();
196 * Make sure all delayed rcu free are flushed before we
200 kmem_cache_destroy(extent_state_cache
);
201 kmem_cache_destroy(extent_buffer_cache
);
203 bioset_free(btrfs_bioset
);
206 void extent_io_tree_init(struct extent_io_tree
*tree
,
209 tree
->state
= RB_ROOT
;
211 tree
->dirty_bytes
= 0;
212 spin_lock_init(&tree
->lock
);
213 tree
->private_data
= private_data
;
216 static struct extent_state
*alloc_extent_state(gfp_t mask
)
218 struct extent_state
*state
;
221 * The given mask might be not appropriate for the slab allocator,
222 * drop the unsupported bits
224 mask
&= ~(__GFP_DMA32
|__GFP_HIGHMEM
);
225 state
= kmem_cache_alloc(extent_state_cache
, mask
);
229 state
->failrec
= NULL
;
230 RB_CLEAR_NODE(&state
->rb_node
);
231 btrfs_leak_debug_add(&state
->leak_list
, &states
);
232 refcount_set(&state
->refs
, 1);
233 init_waitqueue_head(&state
->wq
);
234 trace_alloc_extent_state(state
, mask
, _RET_IP_
);
238 void free_extent_state(struct extent_state
*state
)
242 if (refcount_dec_and_test(&state
->refs
)) {
243 WARN_ON(extent_state_in_tree(state
));
244 btrfs_leak_debug_del(&state
->leak_list
);
245 trace_free_extent_state(state
, _RET_IP_
);
246 kmem_cache_free(extent_state_cache
, state
);
250 static struct rb_node
*tree_insert(struct rb_root
*root
,
251 struct rb_node
*search_start
,
253 struct rb_node
*node
,
254 struct rb_node
***p_in
,
255 struct rb_node
**parent_in
)
258 struct rb_node
*parent
= NULL
;
259 struct tree_entry
*entry
;
261 if (p_in
&& parent_in
) {
267 p
= search_start
? &search_start
: &root
->rb_node
;
270 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
272 if (offset
< entry
->start
)
274 else if (offset
> entry
->end
)
281 rb_link_node(node
, parent
, p
);
282 rb_insert_color(node
, root
);
286 static struct rb_node
*__etree_search(struct extent_io_tree
*tree
, u64 offset
,
287 struct rb_node
**prev_ret
,
288 struct rb_node
**next_ret
,
289 struct rb_node
***p_ret
,
290 struct rb_node
**parent_ret
)
292 struct rb_root
*root
= &tree
->state
;
293 struct rb_node
**n
= &root
->rb_node
;
294 struct rb_node
*prev
= NULL
;
295 struct rb_node
*orig_prev
= NULL
;
296 struct tree_entry
*entry
;
297 struct tree_entry
*prev_entry
= NULL
;
301 entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
304 if (offset
< entry
->start
)
306 else if (offset
> entry
->end
)
319 while (prev
&& offset
> prev_entry
->end
) {
320 prev
= rb_next(prev
);
321 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
328 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
329 while (prev
&& offset
< prev_entry
->start
) {
330 prev
= rb_prev(prev
);
331 prev_entry
= rb_entry(prev
, struct tree_entry
, rb_node
);
338 static inline struct rb_node
*
339 tree_search_for_insert(struct extent_io_tree
*tree
,
341 struct rb_node
***p_ret
,
342 struct rb_node
**parent_ret
)
344 struct rb_node
*prev
= NULL
;
347 ret
= __etree_search(tree
, offset
, &prev
, NULL
, p_ret
, parent_ret
);
353 static inline struct rb_node
*tree_search(struct extent_io_tree
*tree
,
356 return tree_search_for_insert(tree
, offset
, NULL
, NULL
);
359 static void merge_cb(struct extent_io_tree
*tree
, struct extent_state
*new,
360 struct extent_state
*other
)
362 if (tree
->ops
&& tree
->ops
->merge_extent_hook
)
363 tree
->ops
->merge_extent_hook(tree
->private_data
, new, other
);
367 * utility function to look for merge candidates inside a given range.
368 * Any extents with matching state are merged together into a single
369 * extent in the tree. Extents with EXTENT_IO in their state field
370 * are not merged because the end_io handlers need to be able to do
371 * operations on them without sleeping (or doing allocations/splits).
373 * This should be called with the tree lock held.
375 static void merge_state(struct extent_io_tree
*tree
,
376 struct extent_state
*state
)
378 struct extent_state
*other
;
379 struct rb_node
*other_node
;
381 if (state
->state
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
384 other_node
= rb_prev(&state
->rb_node
);
386 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
387 if (other
->end
== state
->start
- 1 &&
388 other
->state
== state
->state
) {
389 merge_cb(tree
, state
, other
);
390 state
->start
= other
->start
;
391 rb_erase(&other
->rb_node
, &tree
->state
);
392 RB_CLEAR_NODE(&other
->rb_node
);
393 free_extent_state(other
);
396 other_node
= rb_next(&state
->rb_node
);
398 other
= rb_entry(other_node
, struct extent_state
, rb_node
);
399 if (other
->start
== state
->end
+ 1 &&
400 other
->state
== state
->state
) {
401 merge_cb(tree
, state
, other
);
402 state
->end
= other
->end
;
403 rb_erase(&other
->rb_node
, &tree
->state
);
404 RB_CLEAR_NODE(&other
->rb_node
);
405 free_extent_state(other
);
410 static void set_state_cb(struct extent_io_tree
*tree
,
411 struct extent_state
*state
, unsigned *bits
)
413 if (tree
->ops
&& tree
->ops
->set_bit_hook
)
414 tree
->ops
->set_bit_hook(tree
->private_data
, state
, bits
);
417 static void clear_state_cb(struct extent_io_tree
*tree
,
418 struct extent_state
*state
, unsigned *bits
)
420 if (tree
->ops
&& tree
->ops
->clear_bit_hook
)
421 tree
->ops
->clear_bit_hook(tree
->private_data
, state
, bits
);
424 static void set_state_bits(struct extent_io_tree
*tree
,
425 struct extent_state
*state
, unsigned *bits
,
426 struct extent_changeset
*changeset
);
429 * insert an extent_state struct into the tree. 'bits' are set on the
430 * struct before it is inserted.
432 * This may return -EEXIST if the extent is already there, in which case the
433 * state struct is freed.
435 * The tree lock is not taken internally. This is a utility function and
436 * probably isn't what you want to call (see set/clear_extent_bit).
438 static int insert_state(struct extent_io_tree
*tree
,
439 struct extent_state
*state
, u64 start
, u64 end
,
441 struct rb_node
**parent
,
442 unsigned *bits
, struct extent_changeset
*changeset
)
444 struct rb_node
*node
;
447 WARN(1, KERN_ERR
"BTRFS: end < start %llu %llu\n",
449 state
->start
= start
;
452 set_state_bits(tree
, state
, bits
, changeset
);
454 node
= tree_insert(&tree
->state
, NULL
, end
, &state
->rb_node
, p
, parent
);
456 struct extent_state
*found
;
457 found
= rb_entry(node
, struct extent_state
, rb_node
);
458 pr_err("BTRFS: found node %llu %llu on insert of %llu %llu\n",
459 found
->start
, found
->end
, start
, end
);
462 merge_state(tree
, state
);
466 static void split_cb(struct extent_io_tree
*tree
, struct extent_state
*orig
,
469 if (tree
->ops
&& tree
->ops
->split_extent_hook
)
470 tree
->ops
->split_extent_hook(tree
->private_data
, orig
, split
);
474 * split a given extent state struct in two, inserting the preallocated
475 * struct 'prealloc' as the newly created second half. 'split' indicates an
476 * offset inside 'orig' where it should be split.
479 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
480 * are two extent state structs in the tree:
481 * prealloc: [orig->start, split - 1]
482 * orig: [ split, orig->end ]
484 * The tree locks are not taken by this function. They need to be held
487 static int split_state(struct extent_io_tree
*tree
, struct extent_state
*orig
,
488 struct extent_state
*prealloc
, u64 split
)
490 struct rb_node
*node
;
492 split_cb(tree
, orig
, split
);
494 prealloc
->start
= orig
->start
;
495 prealloc
->end
= split
- 1;
496 prealloc
->state
= orig
->state
;
499 node
= tree_insert(&tree
->state
, &orig
->rb_node
, prealloc
->end
,
500 &prealloc
->rb_node
, NULL
, NULL
);
502 free_extent_state(prealloc
);
508 static struct extent_state
*next_state(struct extent_state
*state
)
510 struct rb_node
*next
= rb_next(&state
->rb_node
);
512 return rb_entry(next
, struct extent_state
, rb_node
);
518 * utility function to clear some bits in an extent state struct.
519 * it will optionally wake up any one waiting on this state (wake == 1).
521 * If no bits are set on the state struct after clearing things, the
522 * struct is freed and removed from the tree
524 static struct extent_state
*clear_state_bit(struct extent_io_tree
*tree
,
525 struct extent_state
*state
,
526 unsigned *bits
, int wake
,
527 struct extent_changeset
*changeset
)
529 struct extent_state
*next
;
530 unsigned bits_to_clear
= *bits
& ~EXTENT_CTLBITS
;
532 if ((bits_to_clear
& EXTENT_DIRTY
) && (state
->state
& EXTENT_DIRTY
)) {
533 u64 range
= state
->end
- state
->start
+ 1;
534 WARN_ON(range
> tree
->dirty_bytes
);
535 tree
->dirty_bytes
-= range
;
537 clear_state_cb(tree
, state
, bits
);
538 add_extent_changeset(state
, bits_to_clear
, changeset
, 0);
539 state
->state
&= ~bits_to_clear
;
542 if (state
->state
== 0) {
543 next
= next_state(state
);
544 if (extent_state_in_tree(state
)) {
545 rb_erase(&state
->rb_node
, &tree
->state
);
546 RB_CLEAR_NODE(&state
->rb_node
);
547 free_extent_state(state
);
552 merge_state(tree
, state
);
553 next
= next_state(state
);
558 static struct extent_state
*
559 alloc_extent_state_atomic(struct extent_state
*prealloc
)
562 prealloc
= alloc_extent_state(GFP_ATOMIC
);
567 static void extent_io_tree_panic(struct extent_io_tree
*tree
, int err
)
569 btrfs_panic(tree_fs_info(tree
), err
,
570 "Locking error: Extent tree was modified by another thread while locked.");
574 * clear some bits on a range in the tree. This may require splitting
575 * or inserting elements in the tree, so the gfp mask is used to
576 * indicate which allocations or sleeping are allowed.
578 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
579 * the given range from the tree regardless of state (ie for truncate).
581 * the range [start, end] is inclusive.
583 * This takes the tree lock, and returns 0 on success and < 0 on error.
585 static int __clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
586 unsigned bits
, int wake
, int delete,
587 struct extent_state
**cached_state
,
588 gfp_t mask
, struct extent_changeset
*changeset
)
590 struct extent_state
*state
;
591 struct extent_state
*cached
;
592 struct extent_state
*prealloc
= NULL
;
593 struct rb_node
*node
;
598 btrfs_debug_check_extent_io_range(tree
, start
, end
);
600 if (bits
& EXTENT_DELALLOC
)
601 bits
|= EXTENT_NORESERVE
;
604 bits
|= ~EXTENT_CTLBITS
;
605 bits
|= EXTENT_FIRST_DELALLOC
;
607 if (bits
& (EXTENT_IOBITS
| EXTENT_BOUNDARY
))
610 if (!prealloc
&& gfpflags_allow_blocking(mask
)) {
612 * Don't care for allocation failure here because we might end
613 * up not needing the pre-allocated extent state at all, which
614 * is the case if we only have in the tree extent states that
615 * cover our input range and don't cover too any other range.
616 * If we end up needing a new extent state we allocate it later.
618 prealloc
= alloc_extent_state(mask
);
621 spin_lock(&tree
->lock
);
623 cached
= *cached_state
;
626 *cached_state
= NULL
;
630 if (cached
&& extent_state_in_tree(cached
) &&
631 cached
->start
<= start
&& cached
->end
> start
) {
633 refcount_dec(&cached
->refs
);
638 free_extent_state(cached
);
641 * this search will find the extents that end after
644 node
= tree_search(tree
, start
);
647 state
= rb_entry(node
, struct extent_state
, rb_node
);
649 if (state
->start
> end
)
651 WARN_ON(state
->end
< start
);
652 last_end
= state
->end
;
654 /* the state doesn't have the wanted bits, go ahead */
655 if (!(state
->state
& bits
)) {
656 state
= next_state(state
);
661 * | ---- desired range ---- |
663 * | ------------- state -------------- |
665 * We need to split the extent we found, and may flip
666 * bits on second half.
668 * If the extent we found extends past our range, we
669 * just split and search again. It'll get split again
670 * the next time though.
672 * If the extent we found is inside our range, we clear
673 * the desired bit on it.
676 if (state
->start
< start
) {
677 prealloc
= alloc_extent_state_atomic(prealloc
);
679 err
= split_state(tree
, state
, prealloc
, start
);
681 extent_io_tree_panic(tree
, err
);
686 if (state
->end
<= end
) {
687 state
= clear_state_bit(tree
, state
, &bits
, wake
,
694 * | ---- desired range ---- |
696 * We need to split the extent, and clear the bit
699 if (state
->start
<= end
&& state
->end
> end
) {
700 prealloc
= alloc_extent_state_atomic(prealloc
);
702 err
= split_state(tree
, state
, prealloc
, end
+ 1);
704 extent_io_tree_panic(tree
, err
);
709 clear_state_bit(tree
, prealloc
, &bits
, wake
, changeset
);
715 state
= clear_state_bit(tree
, state
, &bits
, wake
, changeset
);
717 if (last_end
== (u64
)-1)
719 start
= last_end
+ 1;
720 if (start
<= end
&& state
&& !need_resched())
726 spin_unlock(&tree
->lock
);
727 if (gfpflags_allow_blocking(mask
))
732 spin_unlock(&tree
->lock
);
734 free_extent_state(prealloc
);
740 static void wait_on_state(struct extent_io_tree
*tree
,
741 struct extent_state
*state
)
742 __releases(tree
->lock
)
743 __acquires(tree
->lock
)
746 prepare_to_wait(&state
->wq
, &wait
, TASK_UNINTERRUPTIBLE
);
747 spin_unlock(&tree
->lock
);
749 spin_lock(&tree
->lock
);
750 finish_wait(&state
->wq
, &wait
);
754 * waits for one or more bits to clear on a range in the state tree.
755 * The range [start, end] is inclusive.
756 * The tree lock is taken by this function
758 static void wait_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
761 struct extent_state
*state
;
762 struct rb_node
*node
;
764 btrfs_debug_check_extent_io_range(tree
, start
, end
);
766 spin_lock(&tree
->lock
);
770 * this search will find all the extents that end after
773 node
= tree_search(tree
, start
);
778 state
= rb_entry(node
, struct extent_state
, rb_node
);
780 if (state
->start
> end
)
783 if (state
->state
& bits
) {
784 start
= state
->start
;
785 refcount_inc(&state
->refs
);
786 wait_on_state(tree
, state
);
787 free_extent_state(state
);
790 start
= state
->end
+ 1;
795 if (!cond_resched_lock(&tree
->lock
)) {
796 node
= rb_next(node
);
801 spin_unlock(&tree
->lock
);
804 static void set_state_bits(struct extent_io_tree
*tree
,
805 struct extent_state
*state
,
806 unsigned *bits
, struct extent_changeset
*changeset
)
808 unsigned bits_to_set
= *bits
& ~EXTENT_CTLBITS
;
810 set_state_cb(tree
, state
, bits
);
811 if ((bits_to_set
& EXTENT_DIRTY
) && !(state
->state
& EXTENT_DIRTY
)) {
812 u64 range
= state
->end
- state
->start
+ 1;
813 tree
->dirty_bytes
+= range
;
815 add_extent_changeset(state
, bits_to_set
, changeset
, 1);
816 state
->state
|= bits_to_set
;
819 static void cache_state_if_flags(struct extent_state
*state
,
820 struct extent_state
**cached_ptr
,
823 if (cached_ptr
&& !(*cached_ptr
)) {
824 if (!flags
|| (state
->state
& flags
)) {
826 refcount_inc(&state
->refs
);
831 static void cache_state(struct extent_state
*state
,
832 struct extent_state
**cached_ptr
)
834 return cache_state_if_flags(state
, cached_ptr
,
835 EXTENT_IOBITS
| EXTENT_BOUNDARY
);
839 * set some bits on a range in the tree. This may require allocations or
840 * sleeping, so the gfp mask is used to indicate what is allowed.
842 * If any of the exclusive bits are set, this will fail with -EEXIST if some
843 * part of the range already has the desired bits set. The start of the
844 * existing range is returned in failed_start in this case.
846 * [start, end] is inclusive This takes the tree lock.
849 static int __must_check
850 __set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
851 unsigned bits
, unsigned exclusive_bits
,
852 u64
*failed_start
, struct extent_state
**cached_state
,
853 gfp_t mask
, struct extent_changeset
*changeset
)
855 struct extent_state
*state
;
856 struct extent_state
*prealloc
= NULL
;
857 struct rb_node
*node
;
859 struct rb_node
*parent
;
864 btrfs_debug_check_extent_io_range(tree
, start
, end
);
866 bits
|= EXTENT_FIRST_DELALLOC
;
868 if (!prealloc
&& gfpflags_allow_blocking(mask
)) {
870 * Don't care for allocation failure here because we might end
871 * up not needing the pre-allocated extent state at all, which
872 * is the case if we only have in the tree extent states that
873 * cover our input range and don't cover too any other range.
874 * If we end up needing a new extent state we allocate it later.
876 prealloc
= alloc_extent_state(mask
);
879 spin_lock(&tree
->lock
);
880 if (cached_state
&& *cached_state
) {
881 state
= *cached_state
;
882 if (state
->start
<= start
&& state
->end
> start
&&
883 extent_state_in_tree(state
)) {
884 node
= &state
->rb_node
;
889 * this search will find all the extents that end after
892 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
894 prealloc
= alloc_extent_state_atomic(prealloc
);
896 err
= insert_state(tree
, prealloc
, start
, end
,
897 &p
, &parent
, &bits
, changeset
);
899 extent_io_tree_panic(tree
, err
);
901 cache_state(prealloc
, cached_state
);
905 state
= rb_entry(node
, struct extent_state
, rb_node
);
907 last_start
= state
->start
;
908 last_end
= state
->end
;
911 * | ---- desired range ---- |
914 * Just lock what we found and keep going
916 if (state
->start
== start
&& state
->end
<= end
) {
917 if (state
->state
& exclusive_bits
) {
918 *failed_start
= state
->start
;
923 set_state_bits(tree
, state
, &bits
, changeset
);
924 cache_state(state
, cached_state
);
925 merge_state(tree
, state
);
926 if (last_end
== (u64
)-1)
928 start
= last_end
+ 1;
929 state
= next_state(state
);
930 if (start
< end
&& state
&& state
->start
== start
&&
937 * | ---- desired range ---- |
940 * | ------------- state -------------- |
942 * We need to split the extent we found, and may flip bits on
945 * If the extent we found extends past our
946 * range, we just split and search again. It'll get split
947 * again the next time though.
949 * If the extent we found is inside our range, we set the
952 if (state
->start
< start
) {
953 if (state
->state
& exclusive_bits
) {
954 *failed_start
= start
;
959 prealloc
= alloc_extent_state_atomic(prealloc
);
961 err
= split_state(tree
, state
, prealloc
, start
);
963 extent_io_tree_panic(tree
, err
);
968 if (state
->end
<= end
) {
969 set_state_bits(tree
, state
, &bits
, changeset
);
970 cache_state(state
, cached_state
);
971 merge_state(tree
, state
);
972 if (last_end
== (u64
)-1)
974 start
= last_end
+ 1;
975 state
= next_state(state
);
976 if (start
< end
&& state
&& state
->start
== start
&&
983 * | ---- desired range ---- |
984 * | state | or | state |
986 * There's a hole, we need to insert something in it and
987 * ignore the extent we found.
989 if (state
->start
> start
) {
991 if (end
< last_start
)
994 this_end
= last_start
- 1;
996 prealloc
= alloc_extent_state_atomic(prealloc
);
1000 * Avoid to free 'prealloc' if it can be merged with
1003 err
= insert_state(tree
, prealloc
, start
, this_end
,
1004 NULL
, NULL
, &bits
, changeset
);
1006 extent_io_tree_panic(tree
, err
);
1008 cache_state(prealloc
, cached_state
);
1010 start
= this_end
+ 1;
1014 * | ---- desired range ---- |
1016 * We need to split the extent, and set the bit
1019 if (state
->start
<= end
&& state
->end
> end
) {
1020 if (state
->state
& exclusive_bits
) {
1021 *failed_start
= start
;
1026 prealloc
= alloc_extent_state_atomic(prealloc
);
1028 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1030 extent_io_tree_panic(tree
, err
);
1032 set_state_bits(tree
, prealloc
, &bits
, changeset
);
1033 cache_state(prealloc
, cached_state
);
1034 merge_state(tree
, prealloc
);
1042 spin_unlock(&tree
->lock
);
1043 if (gfpflags_allow_blocking(mask
))
1048 spin_unlock(&tree
->lock
);
1050 free_extent_state(prealloc
);
1056 int set_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1057 unsigned bits
, u64
* failed_start
,
1058 struct extent_state
**cached_state
, gfp_t mask
)
1060 return __set_extent_bit(tree
, start
, end
, bits
, 0, failed_start
,
1061 cached_state
, mask
, NULL
);
1066 * convert_extent_bit - convert all bits in a given range from one bit to
1068 * @tree: the io tree to search
1069 * @start: the start offset in bytes
1070 * @end: the end offset in bytes (inclusive)
1071 * @bits: the bits to set in this range
1072 * @clear_bits: the bits to clear in this range
1073 * @cached_state: state that we're going to cache
1075 * This will go through and set bits for the given range. If any states exist
1076 * already in this range they are set with the given bit and cleared of the
1077 * clear_bits. This is only meant to be used by things that are mergeable, ie
1078 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1079 * boundary bits like LOCK.
1081 * All allocations are done with GFP_NOFS.
1083 int convert_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1084 unsigned bits
, unsigned clear_bits
,
1085 struct extent_state
**cached_state
)
1087 struct extent_state
*state
;
1088 struct extent_state
*prealloc
= NULL
;
1089 struct rb_node
*node
;
1091 struct rb_node
*parent
;
1095 bool first_iteration
= true;
1097 btrfs_debug_check_extent_io_range(tree
, start
, end
);
1102 * Best effort, don't worry if extent state allocation fails
1103 * here for the first iteration. We might have a cached state
1104 * that matches exactly the target range, in which case no
1105 * extent state allocations are needed. We'll only know this
1106 * after locking the tree.
1108 prealloc
= alloc_extent_state(GFP_NOFS
);
1109 if (!prealloc
&& !first_iteration
)
1113 spin_lock(&tree
->lock
);
1114 if (cached_state
&& *cached_state
) {
1115 state
= *cached_state
;
1116 if (state
->start
<= start
&& state
->end
> start
&&
1117 extent_state_in_tree(state
)) {
1118 node
= &state
->rb_node
;
1124 * this search will find all the extents that end after
1127 node
= tree_search_for_insert(tree
, start
, &p
, &parent
);
1129 prealloc
= alloc_extent_state_atomic(prealloc
);
1134 err
= insert_state(tree
, prealloc
, start
, end
,
1135 &p
, &parent
, &bits
, NULL
);
1137 extent_io_tree_panic(tree
, err
);
1138 cache_state(prealloc
, cached_state
);
1142 state
= rb_entry(node
, struct extent_state
, rb_node
);
1144 last_start
= state
->start
;
1145 last_end
= state
->end
;
1148 * | ---- desired range ---- |
1151 * Just lock what we found and keep going
1153 if (state
->start
== start
&& state
->end
<= end
) {
1154 set_state_bits(tree
, state
, &bits
, NULL
);
1155 cache_state(state
, cached_state
);
1156 state
= clear_state_bit(tree
, state
, &clear_bits
, 0, NULL
);
1157 if (last_end
== (u64
)-1)
1159 start
= last_end
+ 1;
1160 if (start
< end
&& state
&& state
->start
== start
&&
1167 * | ---- desired range ---- |
1170 * | ------------- state -------------- |
1172 * We need to split the extent we found, and may flip bits on
1175 * If the extent we found extends past our
1176 * range, we just split and search again. It'll get split
1177 * again the next time though.
1179 * If the extent we found is inside our range, we set the
1180 * desired bit on it.
1182 if (state
->start
< start
) {
1183 prealloc
= alloc_extent_state_atomic(prealloc
);
1188 err
= split_state(tree
, state
, prealloc
, start
);
1190 extent_io_tree_panic(tree
, err
);
1194 if (state
->end
<= end
) {
1195 set_state_bits(tree
, state
, &bits
, NULL
);
1196 cache_state(state
, cached_state
);
1197 state
= clear_state_bit(tree
, state
, &clear_bits
, 0,
1199 if (last_end
== (u64
)-1)
1201 start
= last_end
+ 1;
1202 if (start
< end
&& state
&& state
->start
== start
&&
1209 * | ---- desired range ---- |
1210 * | state | or | state |
1212 * There's a hole, we need to insert something in it and
1213 * ignore the extent we found.
1215 if (state
->start
> start
) {
1217 if (end
< last_start
)
1220 this_end
= last_start
- 1;
1222 prealloc
= alloc_extent_state_atomic(prealloc
);
1229 * Avoid to free 'prealloc' if it can be merged with
1232 err
= insert_state(tree
, prealloc
, start
, this_end
,
1233 NULL
, NULL
, &bits
, NULL
);
1235 extent_io_tree_panic(tree
, err
);
1236 cache_state(prealloc
, cached_state
);
1238 start
= this_end
+ 1;
1242 * | ---- desired range ---- |
1244 * We need to split the extent, and set the bit
1247 if (state
->start
<= end
&& state
->end
> end
) {
1248 prealloc
= alloc_extent_state_atomic(prealloc
);
1254 err
= split_state(tree
, state
, prealloc
, end
+ 1);
1256 extent_io_tree_panic(tree
, err
);
1258 set_state_bits(tree
, prealloc
, &bits
, NULL
);
1259 cache_state(prealloc
, cached_state
);
1260 clear_state_bit(tree
, prealloc
, &clear_bits
, 0, NULL
);
1268 spin_unlock(&tree
->lock
);
1270 first_iteration
= false;
1274 spin_unlock(&tree
->lock
);
1276 free_extent_state(prealloc
);
1281 /* wrappers around set/clear extent bit */
1282 int set_record_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1283 unsigned bits
, struct extent_changeset
*changeset
)
1286 * We don't support EXTENT_LOCKED yet, as current changeset will
1287 * record any bits changed, so for EXTENT_LOCKED case, it will
1288 * either fail with -EEXIST or changeset will record the whole
1291 BUG_ON(bits
& EXTENT_LOCKED
);
1293 return __set_extent_bit(tree
, start
, end
, bits
, 0, NULL
, NULL
, GFP_NOFS
,
1297 int clear_extent_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1298 unsigned bits
, int wake
, int delete,
1299 struct extent_state
**cached
, gfp_t mask
)
1301 return __clear_extent_bit(tree
, start
, end
, bits
, wake
, delete,
1302 cached
, mask
, NULL
);
1305 int clear_record_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1306 unsigned bits
, struct extent_changeset
*changeset
)
1309 * Don't support EXTENT_LOCKED case, same reason as
1310 * set_record_extent_bits().
1312 BUG_ON(bits
& EXTENT_LOCKED
);
1314 return __clear_extent_bit(tree
, start
, end
, bits
, 0, 0, NULL
, GFP_NOFS
,
1319 * either insert or lock state struct between start and end use mask to tell
1320 * us if waiting is desired.
1322 int lock_extent_bits(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1323 struct extent_state
**cached_state
)
1329 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
,
1330 EXTENT_LOCKED
, &failed_start
,
1331 cached_state
, GFP_NOFS
, NULL
);
1332 if (err
== -EEXIST
) {
1333 wait_extent_bit(tree
, failed_start
, end
, EXTENT_LOCKED
);
1334 start
= failed_start
;
1337 WARN_ON(start
> end
);
1342 int try_lock_extent(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1347 err
= __set_extent_bit(tree
, start
, end
, EXTENT_LOCKED
, EXTENT_LOCKED
,
1348 &failed_start
, NULL
, GFP_NOFS
, NULL
);
1349 if (err
== -EEXIST
) {
1350 if (failed_start
> start
)
1351 clear_extent_bit(tree
, start
, failed_start
- 1,
1352 EXTENT_LOCKED
, 1, 0, NULL
, GFP_NOFS
);
1358 void extent_range_clear_dirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1360 unsigned long index
= start
>> PAGE_SHIFT
;
1361 unsigned long end_index
= end
>> PAGE_SHIFT
;
1364 while (index
<= end_index
) {
1365 page
= find_get_page(inode
->i_mapping
, index
);
1366 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1367 clear_page_dirty_for_io(page
);
1373 void extent_range_redirty_for_io(struct inode
*inode
, u64 start
, u64 end
)
1375 unsigned long index
= start
>> PAGE_SHIFT
;
1376 unsigned long end_index
= end
>> PAGE_SHIFT
;
1379 while (index
<= end_index
) {
1380 page
= find_get_page(inode
->i_mapping
, index
);
1381 BUG_ON(!page
); /* Pages should be in the extent_io_tree */
1382 __set_page_dirty_nobuffers(page
);
1383 account_page_redirty(page
);
1390 * helper function to set both pages and extents in the tree writeback
1392 static void set_range_writeback(struct extent_io_tree
*tree
, u64 start
, u64 end
)
1394 tree
->ops
->set_range_writeback(tree
->private_data
, start
, end
);
1397 /* find the first state struct with 'bits' set after 'start', and
1398 * return it. tree->lock must be held. NULL will returned if
1399 * nothing was found after 'start'
1401 static struct extent_state
*
1402 find_first_extent_bit_state(struct extent_io_tree
*tree
,
1403 u64 start
, unsigned bits
)
1405 struct rb_node
*node
;
1406 struct extent_state
*state
;
1409 * this search will find all the extents that end after
1412 node
= tree_search(tree
, start
);
1417 state
= rb_entry(node
, struct extent_state
, rb_node
);
1418 if (state
->end
>= start
&& (state
->state
& bits
))
1421 node
= rb_next(node
);
1430 * find the first offset in the io tree with 'bits' set. zero is
1431 * returned if we find something, and *start_ret and *end_ret are
1432 * set to reflect the state struct that was found.
1434 * If nothing was found, 1 is returned. If found something, return 0.
1436 int find_first_extent_bit(struct extent_io_tree
*tree
, u64 start
,
1437 u64
*start_ret
, u64
*end_ret
, unsigned bits
,
1438 struct extent_state
**cached_state
)
1440 struct extent_state
*state
;
1444 spin_lock(&tree
->lock
);
1445 if (cached_state
&& *cached_state
) {
1446 state
= *cached_state
;
1447 if (state
->end
== start
- 1 && extent_state_in_tree(state
)) {
1448 n
= rb_next(&state
->rb_node
);
1450 state
= rb_entry(n
, struct extent_state
,
1452 if (state
->state
& bits
)
1456 free_extent_state(*cached_state
);
1457 *cached_state
= NULL
;
1460 free_extent_state(*cached_state
);
1461 *cached_state
= NULL
;
1464 state
= find_first_extent_bit_state(tree
, start
, bits
);
1467 cache_state_if_flags(state
, cached_state
, 0);
1468 *start_ret
= state
->start
;
1469 *end_ret
= state
->end
;
1473 spin_unlock(&tree
->lock
);
1478 * find a contiguous range of bytes in the file marked as delalloc, not
1479 * more than 'max_bytes'. start and end are used to return the range,
1481 * 1 is returned if we find something, 0 if nothing was in the tree
1483 static noinline u64
find_delalloc_range(struct extent_io_tree
*tree
,
1484 u64
*start
, u64
*end
, u64 max_bytes
,
1485 struct extent_state
**cached_state
)
1487 struct rb_node
*node
;
1488 struct extent_state
*state
;
1489 u64 cur_start
= *start
;
1491 u64 total_bytes
= 0;
1493 spin_lock(&tree
->lock
);
1496 * this search will find all the extents that end after
1499 node
= tree_search(tree
, cur_start
);
1507 state
= rb_entry(node
, struct extent_state
, rb_node
);
1508 if (found
&& (state
->start
!= cur_start
||
1509 (state
->state
& EXTENT_BOUNDARY
))) {
1512 if (!(state
->state
& EXTENT_DELALLOC
)) {
1518 *start
= state
->start
;
1519 *cached_state
= state
;
1520 refcount_inc(&state
->refs
);
1524 cur_start
= state
->end
+ 1;
1525 node
= rb_next(node
);
1526 total_bytes
+= state
->end
- state
->start
+ 1;
1527 if (total_bytes
>= max_bytes
)
1533 spin_unlock(&tree
->lock
);
1537 static int __process_pages_contig(struct address_space
*mapping
,
1538 struct page
*locked_page
,
1539 pgoff_t start_index
, pgoff_t end_index
,
1540 unsigned long page_ops
, pgoff_t
*index_ret
);
1542 static noinline
void __unlock_for_delalloc(struct inode
*inode
,
1543 struct page
*locked_page
,
1546 unsigned long index
= start
>> PAGE_SHIFT
;
1547 unsigned long end_index
= end
>> PAGE_SHIFT
;
1549 ASSERT(locked_page
);
1550 if (index
== locked_page
->index
&& end_index
== index
)
1553 __process_pages_contig(inode
->i_mapping
, locked_page
, index
, end_index
,
1557 static noinline
int lock_delalloc_pages(struct inode
*inode
,
1558 struct page
*locked_page
,
1562 unsigned long index
= delalloc_start
>> PAGE_SHIFT
;
1563 unsigned long index_ret
= index
;
1564 unsigned long end_index
= delalloc_end
>> PAGE_SHIFT
;
1567 ASSERT(locked_page
);
1568 if (index
== locked_page
->index
&& index
== end_index
)
1571 ret
= __process_pages_contig(inode
->i_mapping
, locked_page
, index
,
1572 end_index
, PAGE_LOCK
, &index_ret
);
1574 __unlock_for_delalloc(inode
, locked_page
, delalloc_start
,
1575 (u64
)index_ret
<< PAGE_SHIFT
);
1580 * find a contiguous range of bytes in the file marked as delalloc, not
1581 * more than 'max_bytes'. start and end are used to return the range,
1583 * 1 is returned if we find something, 0 if nothing was in the tree
1585 STATIC u64
find_lock_delalloc_range(struct inode
*inode
,
1586 struct extent_io_tree
*tree
,
1587 struct page
*locked_page
, u64
*start
,
1588 u64
*end
, u64 max_bytes
)
1593 struct extent_state
*cached_state
= NULL
;
1598 /* step one, find a bunch of delalloc bytes starting at start */
1599 delalloc_start
= *start
;
1601 found
= find_delalloc_range(tree
, &delalloc_start
, &delalloc_end
,
1602 max_bytes
, &cached_state
);
1603 if (!found
|| delalloc_end
<= *start
) {
1604 *start
= delalloc_start
;
1605 *end
= delalloc_end
;
1606 free_extent_state(cached_state
);
1611 * start comes from the offset of locked_page. We have to lock
1612 * pages in order, so we can't process delalloc bytes before
1615 if (delalloc_start
< *start
)
1616 delalloc_start
= *start
;
1619 * make sure to limit the number of pages we try to lock down
1621 if (delalloc_end
+ 1 - delalloc_start
> max_bytes
)
1622 delalloc_end
= delalloc_start
+ max_bytes
- 1;
1624 /* step two, lock all the pages after the page that has start */
1625 ret
= lock_delalloc_pages(inode
, locked_page
,
1626 delalloc_start
, delalloc_end
);
1627 if (ret
== -EAGAIN
) {
1628 /* some of the pages are gone, lets avoid looping by
1629 * shortening the size of the delalloc range we're searching
1631 free_extent_state(cached_state
);
1632 cached_state
= NULL
;
1634 max_bytes
= PAGE_SIZE
;
1642 BUG_ON(ret
); /* Only valid values are 0 and -EAGAIN */
1644 /* step three, lock the state bits for the whole range */
1645 lock_extent_bits(tree
, delalloc_start
, delalloc_end
, &cached_state
);
1647 /* then test to make sure it is all still delalloc */
1648 ret
= test_range_bit(tree
, delalloc_start
, delalloc_end
,
1649 EXTENT_DELALLOC
, 1, cached_state
);
1651 unlock_extent_cached(tree
, delalloc_start
, delalloc_end
,
1652 &cached_state
, GFP_NOFS
);
1653 __unlock_for_delalloc(inode
, locked_page
,
1654 delalloc_start
, delalloc_end
);
1658 free_extent_state(cached_state
);
1659 *start
= delalloc_start
;
1660 *end
= delalloc_end
;
1665 static int __process_pages_contig(struct address_space
*mapping
,
1666 struct page
*locked_page
,
1667 pgoff_t start_index
, pgoff_t end_index
,
1668 unsigned long page_ops
, pgoff_t
*index_ret
)
1670 unsigned long nr_pages
= end_index
- start_index
+ 1;
1671 unsigned long pages_locked
= 0;
1672 pgoff_t index
= start_index
;
1673 struct page
*pages
[16];
1678 if (page_ops
& PAGE_LOCK
) {
1679 ASSERT(page_ops
== PAGE_LOCK
);
1680 ASSERT(index_ret
&& *index_ret
== start_index
);
1683 if ((page_ops
& PAGE_SET_ERROR
) && nr_pages
> 0)
1684 mapping_set_error(mapping
, -EIO
);
1686 while (nr_pages
> 0) {
1687 ret
= find_get_pages_contig(mapping
, index
,
1688 min_t(unsigned long,
1689 nr_pages
, ARRAY_SIZE(pages
)), pages
);
1692 * Only if we're going to lock these pages,
1693 * can we find nothing at @index.
1695 ASSERT(page_ops
& PAGE_LOCK
);
1700 for (i
= 0; i
< ret
; i
++) {
1701 if (page_ops
& PAGE_SET_PRIVATE2
)
1702 SetPagePrivate2(pages
[i
]);
1704 if (pages
[i
] == locked_page
) {
1709 if (page_ops
& PAGE_CLEAR_DIRTY
)
1710 clear_page_dirty_for_io(pages
[i
]);
1711 if (page_ops
& PAGE_SET_WRITEBACK
)
1712 set_page_writeback(pages
[i
]);
1713 if (page_ops
& PAGE_SET_ERROR
)
1714 SetPageError(pages
[i
]);
1715 if (page_ops
& PAGE_END_WRITEBACK
)
1716 end_page_writeback(pages
[i
]);
1717 if (page_ops
& PAGE_UNLOCK
)
1718 unlock_page(pages
[i
]);
1719 if (page_ops
& PAGE_LOCK
) {
1720 lock_page(pages
[i
]);
1721 if (!PageDirty(pages
[i
]) ||
1722 pages
[i
]->mapping
!= mapping
) {
1723 unlock_page(pages
[i
]);
1737 if (err
&& index_ret
)
1738 *index_ret
= start_index
+ pages_locked
- 1;
1742 void extent_clear_unlock_delalloc(struct inode
*inode
, u64 start
, u64 end
,
1743 u64 delalloc_end
, struct page
*locked_page
,
1744 unsigned clear_bits
,
1745 unsigned long page_ops
)
1747 clear_extent_bit(&BTRFS_I(inode
)->io_tree
, start
, end
, clear_bits
, 1, 0,
1750 __process_pages_contig(inode
->i_mapping
, locked_page
,
1751 start
>> PAGE_SHIFT
, end
>> PAGE_SHIFT
,
1756 * count the number of bytes in the tree that have a given bit(s)
1757 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1758 * cached. The total number found is returned.
1760 u64
count_range_bits(struct extent_io_tree
*tree
,
1761 u64
*start
, u64 search_end
, u64 max_bytes
,
1762 unsigned bits
, int contig
)
1764 struct rb_node
*node
;
1765 struct extent_state
*state
;
1766 u64 cur_start
= *start
;
1767 u64 total_bytes
= 0;
1771 if (WARN_ON(search_end
<= cur_start
))
1774 spin_lock(&tree
->lock
);
1775 if (cur_start
== 0 && bits
== EXTENT_DIRTY
) {
1776 total_bytes
= tree
->dirty_bytes
;
1780 * this search will find all the extents that end after
1783 node
= tree_search(tree
, cur_start
);
1788 state
= rb_entry(node
, struct extent_state
, rb_node
);
1789 if (state
->start
> search_end
)
1791 if (contig
&& found
&& state
->start
> last
+ 1)
1793 if (state
->end
>= cur_start
&& (state
->state
& bits
) == bits
) {
1794 total_bytes
+= min(search_end
, state
->end
) + 1 -
1795 max(cur_start
, state
->start
);
1796 if (total_bytes
>= max_bytes
)
1799 *start
= max(cur_start
, state
->start
);
1803 } else if (contig
&& found
) {
1806 node
= rb_next(node
);
1811 spin_unlock(&tree
->lock
);
1816 * set the private field for a given byte offset in the tree. If there isn't
1817 * an extent_state there already, this does nothing.
1819 static noinline
int set_state_failrec(struct extent_io_tree
*tree
, u64 start
,
1820 struct io_failure_record
*failrec
)
1822 struct rb_node
*node
;
1823 struct extent_state
*state
;
1826 spin_lock(&tree
->lock
);
1828 * this search will find all the extents that end after
1831 node
= tree_search(tree
, start
);
1836 state
= rb_entry(node
, struct extent_state
, rb_node
);
1837 if (state
->start
!= start
) {
1841 state
->failrec
= failrec
;
1843 spin_unlock(&tree
->lock
);
1847 static noinline
int get_state_failrec(struct extent_io_tree
*tree
, u64 start
,
1848 struct io_failure_record
**failrec
)
1850 struct rb_node
*node
;
1851 struct extent_state
*state
;
1854 spin_lock(&tree
->lock
);
1856 * this search will find all the extents that end after
1859 node
= tree_search(tree
, start
);
1864 state
= rb_entry(node
, struct extent_state
, rb_node
);
1865 if (state
->start
!= start
) {
1869 *failrec
= state
->failrec
;
1871 spin_unlock(&tree
->lock
);
1876 * searches a range in the state tree for a given mask.
1877 * If 'filled' == 1, this returns 1 only if every extent in the tree
1878 * has the bits set. Otherwise, 1 is returned if any bit in the
1879 * range is found set.
1881 int test_range_bit(struct extent_io_tree
*tree
, u64 start
, u64 end
,
1882 unsigned bits
, int filled
, struct extent_state
*cached
)
1884 struct extent_state
*state
= NULL
;
1885 struct rb_node
*node
;
1888 spin_lock(&tree
->lock
);
1889 if (cached
&& extent_state_in_tree(cached
) && cached
->start
<= start
&&
1890 cached
->end
> start
)
1891 node
= &cached
->rb_node
;
1893 node
= tree_search(tree
, start
);
1894 while (node
&& start
<= end
) {
1895 state
= rb_entry(node
, struct extent_state
, rb_node
);
1897 if (filled
&& state
->start
> start
) {
1902 if (state
->start
> end
)
1905 if (state
->state
& bits
) {
1909 } else if (filled
) {
1914 if (state
->end
== (u64
)-1)
1917 start
= state
->end
+ 1;
1920 node
= rb_next(node
);
1927 spin_unlock(&tree
->lock
);
1932 * helper function to set a given page up to date if all the
1933 * extents in the tree for that page are up to date
1935 static void check_page_uptodate(struct extent_io_tree
*tree
, struct page
*page
)
1937 u64 start
= page_offset(page
);
1938 u64 end
= start
+ PAGE_SIZE
- 1;
1939 if (test_range_bit(tree
, start
, end
, EXTENT_UPTODATE
, 1, NULL
))
1940 SetPageUptodate(page
);
1943 int free_io_failure(struct extent_io_tree
*failure_tree
,
1944 struct extent_io_tree
*io_tree
,
1945 struct io_failure_record
*rec
)
1950 set_state_failrec(failure_tree
, rec
->start
, NULL
);
1951 ret
= clear_extent_bits(failure_tree
, rec
->start
,
1952 rec
->start
+ rec
->len
- 1,
1953 EXTENT_LOCKED
| EXTENT_DIRTY
);
1957 ret
= clear_extent_bits(io_tree
, rec
->start
,
1958 rec
->start
+ rec
->len
- 1,
1968 * this bypasses the standard btrfs submit functions deliberately, as
1969 * the standard behavior is to write all copies in a raid setup. here we only
1970 * want to write the one bad copy. so we do the mapping for ourselves and issue
1971 * submit_bio directly.
1972 * to avoid any synchronization issues, wait for the data after writing, which
1973 * actually prevents the read that triggered the error from finishing.
1974 * currently, there can be no more than two copies of every data bit. thus,
1975 * exactly one rewrite is required.
1977 int repair_io_failure(struct btrfs_fs_info
*fs_info
, u64 ino
, u64 start
,
1978 u64 length
, u64 logical
, struct page
*page
,
1979 unsigned int pg_offset
, int mirror_num
)
1982 struct btrfs_device
*dev
;
1985 struct btrfs_bio
*bbio
= NULL
;
1988 ASSERT(!(fs_info
->sb
->s_flags
& MS_RDONLY
));
1989 BUG_ON(!mirror_num
);
1991 bio
= btrfs_io_bio_alloc(1);
1992 bio
->bi_iter
.bi_size
= 0;
1993 map_length
= length
;
1996 * Avoid races with device replace and make sure our bbio has devices
1997 * associated to its stripes that don't go away while we are doing the
1998 * read repair operation.
2000 btrfs_bio_counter_inc_blocked(fs_info
);
2001 if (btrfs_is_parity_mirror(fs_info
, logical
, length
)) {
2003 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
2004 * to update all raid stripes, but here we just want to correct
2005 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
2006 * stripe's dev and sector.
2008 ret
= btrfs_map_block(fs_info
, BTRFS_MAP_READ
, logical
,
2009 &map_length
, &bbio
, 0);
2011 btrfs_bio_counter_dec(fs_info
);
2015 ASSERT(bbio
->mirror_num
== 1);
2017 ret
= btrfs_map_block(fs_info
, BTRFS_MAP_WRITE
, logical
,
2018 &map_length
, &bbio
, mirror_num
);
2020 btrfs_bio_counter_dec(fs_info
);
2024 BUG_ON(mirror_num
!= bbio
->mirror_num
);
2027 sector
= bbio
->stripes
[bbio
->mirror_num
- 1].physical
>> 9;
2028 bio
->bi_iter
.bi_sector
= sector
;
2029 dev
= bbio
->stripes
[bbio
->mirror_num
- 1].dev
;
2030 btrfs_put_bbio(bbio
);
2031 if (!dev
|| !dev
->bdev
|| !dev
->writeable
) {
2032 btrfs_bio_counter_dec(fs_info
);
2036 bio_set_dev(bio
, dev
->bdev
);
2037 bio
->bi_opf
= REQ_OP_WRITE
| REQ_SYNC
;
2038 bio_add_page(bio
, page
, length
, pg_offset
);
2040 if (btrfsic_submit_bio_wait(bio
)) {
2041 /* try to remap that extent elsewhere? */
2042 btrfs_bio_counter_dec(fs_info
);
2044 btrfs_dev_stat_inc_and_print(dev
, BTRFS_DEV_STAT_WRITE_ERRS
);
2048 btrfs_info_rl_in_rcu(fs_info
,
2049 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2051 rcu_str_deref(dev
->name
), sector
);
2052 btrfs_bio_counter_dec(fs_info
);
2057 int repair_eb_io_failure(struct btrfs_fs_info
*fs_info
,
2058 struct extent_buffer
*eb
, int mirror_num
)
2060 u64 start
= eb
->start
;
2061 unsigned long i
, num_pages
= num_extent_pages(eb
->start
, eb
->len
);
2064 if (sb_rdonly(fs_info
->sb
))
2067 for (i
= 0; i
< num_pages
; i
++) {
2068 struct page
*p
= eb
->pages
[i
];
2070 ret
= repair_io_failure(fs_info
, 0, start
, PAGE_SIZE
, start
, p
,
2071 start
- page_offset(p
), mirror_num
);
2081 * each time an IO finishes, we do a fast check in the IO failure tree
2082 * to see if we need to process or clean up an io_failure_record
2084 int clean_io_failure(struct btrfs_fs_info
*fs_info
,
2085 struct extent_io_tree
*failure_tree
,
2086 struct extent_io_tree
*io_tree
, u64 start
,
2087 struct page
*page
, u64 ino
, unsigned int pg_offset
)
2090 struct io_failure_record
*failrec
;
2091 struct extent_state
*state
;
2096 ret
= count_range_bits(failure_tree
, &private, (u64
)-1, 1,
2101 ret
= get_state_failrec(failure_tree
, start
, &failrec
);
2105 BUG_ON(!failrec
->this_mirror
);
2107 if (failrec
->in_validation
) {
2108 /* there was no real error, just free the record */
2109 btrfs_debug(fs_info
,
2110 "clean_io_failure: freeing dummy error at %llu",
2114 if (sb_rdonly(fs_info
->sb
))
2117 spin_lock(&io_tree
->lock
);
2118 state
= find_first_extent_bit_state(io_tree
,
2121 spin_unlock(&io_tree
->lock
);
2123 if (state
&& state
->start
<= failrec
->start
&&
2124 state
->end
>= failrec
->start
+ failrec
->len
- 1) {
2125 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
,
2127 if (num_copies
> 1) {
2128 repair_io_failure(fs_info
, ino
, start
, failrec
->len
,
2129 failrec
->logical
, page
, pg_offset
,
2130 failrec
->failed_mirror
);
2135 free_io_failure(failure_tree
, io_tree
, failrec
);
2141 * Can be called when
2142 * - hold extent lock
2143 * - under ordered extent
2144 * - the inode is freeing
2146 void btrfs_free_io_failure_record(struct btrfs_inode
*inode
, u64 start
, u64 end
)
2148 struct extent_io_tree
*failure_tree
= &inode
->io_failure_tree
;
2149 struct io_failure_record
*failrec
;
2150 struct extent_state
*state
, *next
;
2152 if (RB_EMPTY_ROOT(&failure_tree
->state
))
2155 spin_lock(&failure_tree
->lock
);
2156 state
= find_first_extent_bit_state(failure_tree
, start
, EXTENT_DIRTY
);
2158 if (state
->start
> end
)
2161 ASSERT(state
->end
<= end
);
2163 next
= next_state(state
);
2165 failrec
= state
->failrec
;
2166 free_extent_state(state
);
2171 spin_unlock(&failure_tree
->lock
);
2174 int btrfs_get_io_failure_record(struct inode
*inode
, u64 start
, u64 end
,
2175 struct io_failure_record
**failrec_ret
)
2177 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2178 struct io_failure_record
*failrec
;
2179 struct extent_map
*em
;
2180 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2181 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2182 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2186 ret
= get_state_failrec(failure_tree
, start
, &failrec
);
2188 failrec
= kzalloc(sizeof(*failrec
), GFP_NOFS
);
2192 failrec
->start
= start
;
2193 failrec
->len
= end
- start
+ 1;
2194 failrec
->this_mirror
= 0;
2195 failrec
->bio_flags
= 0;
2196 failrec
->in_validation
= 0;
2198 read_lock(&em_tree
->lock
);
2199 em
= lookup_extent_mapping(em_tree
, start
, failrec
->len
);
2201 read_unlock(&em_tree
->lock
);
2206 if (em
->start
> start
|| em
->start
+ em
->len
<= start
) {
2207 free_extent_map(em
);
2210 read_unlock(&em_tree
->lock
);
2216 logical
= start
- em
->start
;
2217 logical
= em
->block_start
+ logical
;
2218 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2219 logical
= em
->block_start
;
2220 failrec
->bio_flags
= EXTENT_BIO_COMPRESSED
;
2221 extent_set_compress_type(&failrec
->bio_flags
,
2225 btrfs_debug(fs_info
,
2226 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2227 logical
, start
, failrec
->len
);
2229 failrec
->logical
= logical
;
2230 free_extent_map(em
);
2232 /* set the bits in the private failure tree */
2233 ret
= set_extent_bits(failure_tree
, start
, end
,
2234 EXTENT_LOCKED
| EXTENT_DIRTY
);
2236 ret
= set_state_failrec(failure_tree
, start
, failrec
);
2237 /* set the bits in the inode's tree */
2239 ret
= set_extent_bits(tree
, start
, end
, EXTENT_DAMAGED
);
2245 btrfs_debug(fs_info
,
2246 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2247 failrec
->logical
, failrec
->start
, failrec
->len
,
2248 failrec
->in_validation
);
2250 * when data can be on disk more than twice, add to failrec here
2251 * (e.g. with a list for failed_mirror) to make
2252 * clean_io_failure() clean all those errors at once.
2256 *failrec_ret
= failrec
;
2261 bool btrfs_check_repairable(struct inode
*inode
, struct bio
*failed_bio
,
2262 struct io_failure_record
*failrec
, int failed_mirror
)
2264 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2267 num_copies
= btrfs_num_copies(fs_info
, failrec
->logical
, failrec
->len
);
2268 if (num_copies
== 1) {
2270 * we only have a single copy of the data, so don't bother with
2271 * all the retry and error correction code that follows. no
2272 * matter what the error is, it is very likely to persist.
2274 btrfs_debug(fs_info
,
2275 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2276 num_copies
, failrec
->this_mirror
, failed_mirror
);
2281 * there are two premises:
2282 * a) deliver good data to the caller
2283 * b) correct the bad sectors on disk
2285 if (failed_bio
->bi_vcnt
> 1) {
2287 * to fulfill b), we need to know the exact failing sectors, as
2288 * we don't want to rewrite any more than the failed ones. thus,
2289 * we need separate read requests for the failed bio
2291 * if the following BUG_ON triggers, our validation request got
2292 * merged. we need separate requests for our algorithm to work.
2294 BUG_ON(failrec
->in_validation
);
2295 failrec
->in_validation
= 1;
2296 failrec
->this_mirror
= failed_mirror
;
2299 * we're ready to fulfill a) and b) alongside. get a good copy
2300 * of the failed sector and if we succeed, we have setup
2301 * everything for repair_io_failure to do the rest for us.
2303 if (failrec
->in_validation
) {
2304 BUG_ON(failrec
->this_mirror
!= failed_mirror
);
2305 failrec
->in_validation
= 0;
2306 failrec
->this_mirror
= 0;
2308 failrec
->failed_mirror
= failed_mirror
;
2309 failrec
->this_mirror
++;
2310 if (failrec
->this_mirror
== failed_mirror
)
2311 failrec
->this_mirror
++;
2314 if (failrec
->this_mirror
> num_copies
) {
2315 btrfs_debug(fs_info
,
2316 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2317 num_copies
, failrec
->this_mirror
, failed_mirror
);
2325 struct bio
*btrfs_create_repair_bio(struct inode
*inode
, struct bio
*failed_bio
,
2326 struct io_failure_record
*failrec
,
2327 struct page
*page
, int pg_offset
, int icsum
,
2328 bio_end_io_t
*endio_func
, void *data
)
2330 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2332 struct btrfs_io_bio
*btrfs_failed_bio
;
2333 struct btrfs_io_bio
*btrfs_bio
;
2335 bio
= btrfs_io_bio_alloc(1);
2336 bio
->bi_end_io
= endio_func
;
2337 bio
->bi_iter
.bi_sector
= failrec
->logical
>> 9;
2338 bio_set_dev(bio
, fs_info
->fs_devices
->latest_bdev
);
2339 bio
->bi_iter
.bi_size
= 0;
2340 bio
->bi_private
= data
;
2342 btrfs_failed_bio
= btrfs_io_bio(failed_bio
);
2343 if (btrfs_failed_bio
->csum
) {
2344 u16 csum_size
= btrfs_super_csum_size(fs_info
->super_copy
);
2346 btrfs_bio
= btrfs_io_bio(bio
);
2347 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
2349 memcpy(btrfs_bio
->csum
, btrfs_failed_bio
->csum
+ icsum
,
2353 bio_add_page(bio
, page
, failrec
->len
, pg_offset
);
2359 * this is a generic handler for readpage errors (default
2360 * readpage_io_failed_hook). if other copies exist, read those and write back
2361 * good data to the failed position. does not investigate in remapping the
2362 * failed extent elsewhere, hoping the device will be smart enough to do this as
2366 static int bio_readpage_error(struct bio
*failed_bio
, u64 phy_offset
,
2367 struct page
*page
, u64 start
, u64 end
,
2370 struct io_failure_record
*failrec
;
2371 struct inode
*inode
= page
->mapping
->host
;
2372 struct extent_io_tree
*tree
= &BTRFS_I(inode
)->io_tree
;
2373 struct extent_io_tree
*failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2376 blk_status_t status
;
2379 BUG_ON(bio_op(failed_bio
) == REQ_OP_WRITE
);
2381 ret
= btrfs_get_io_failure_record(inode
, start
, end
, &failrec
);
2385 if (!btrfs_check_repairable(inode
, failed_bio
, failrec
,
2387 free_io_failure(failure_tree
, tree
, failrec
);
2391 if (failed_bio
->bi_vcnt
> 1)
2392 read_mode
|= REQ_FAILFAST_DEV
;
2394 phy_offset
>>= inode
->i_sb
->s_blocksize_bits
;
2395 bio
= btrfs_create_repair_bio(inode
, failed_bio
, failrec
, page
,
2396 start
- page_offset(page
),
2397 (int)phy_offset
, failed_bio
->bi_end_io
,
2399 bio_set_op_attrs(bio
, REQ_OP_READ
, read_mode
);
2401 btrfs_debug(btrfs_sb(inode
->i_sb
),
2402 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2403 read_mode
, failrec
->this_mirror
, failrec
->in_validation
);
2405 status
= tree
->ops
->submit_bio_hook(tree
->private_data
, bio
, failrec
->this_mirror
,
2406 failrec
->bio_flags
, 0);
2408 free_io_failure(failure_tree
, tree
, failrec
);
2410 ret
= blk_status_to_errno(status
);
2416 /* lots and lots of room for performance fixes in the end_bio funcs */
2418 void end_extent_writepage(struct page
*page
, int err
, u64 start
, u64 end
)
2420 int uptodate
= (err
== 0);
2421 struct extent_io_tree
*tree
;
2424 tree
= &BTRFS_I(page
->mapping
->host
)->io_tree
;
2426 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
2427 tree
->ops
->writepage_end_io_hook(page
, start
, end
, NULL
,
2431 ClearPageUptodate(page
);
2433 ret
= err
< 0 ? err
: -EIO
;
2434 mapping_set_error(page
->mapping
, ret
);
2439 * after a writepage IO is done, we need to:
2440 * clear the uptodate bits on error
2441 * clear the writeback bits in the extent tree for this IO
2442 * end_page_writeback if the page has no more pending IO
2444 * Scheduling is not allowed, so the extent state tree is expected
2445 * to have one and only one object corresponding to this IO.
2447 static void end_bio_extent_writepage(struct bio
*bio
)
2449 int error
= blk_status_to_errno(bio
->bi_status
);
2450 struct bio_vec
*bvec
;
2455 ASSERT(!bio_flagged(bio
, BIO_CLONED
));
2456 bio_for_each_segment_all(bvec
, bio
, i
) {
2457 struct page
*page
= bvec
->bv_page
;
2458 struct inode
*inode
= page
->mapping
->host
;
2459 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2461 /* We always issue full-page reads, but if some block
2462 * in a page fails to read, blk_update_request() will
2463 * advance bv_offset and adjust bv_len to compensate.
2464 * Print a warning for nonzero offsets, and an error
2465 * if they don't add up to a full page. */
2466 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_SIZE
) {
2467 if (bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_SIZE
)
2469 "partial page write in btrfs with offset %u and length %u",
2470 bvec
->bv_offset
, bvec
->bv_len
);
2473 "incomplete page write in btrfs with offset %u and length %u",
2474 bvec
->bv_offset
, bvec
->bv_len
);
2477 start
= page_offset(page
);
2478 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2480 end_extent_writepage(page
, error
, start
, end
);
2481 end_page_writeback(page
);
2488 endio_readpage_release_extent(struct extent_io_tree
*tree
, u64 start
, u64 len
,
2491 struct extent_state
*cached
= NULL
;
2492 u64 end
= start
+ len
- 1;
2494 if (uptodate
&& tree
->track_uptodate
)
2495 set_extent_uptodate(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2496 unlock_extent_cached(tree
, start
, end
, &cached
, GFP_ATOMIC
);
2500 * after a readpage IO is done, we need to:
2501 * clear the uptodate bits on error
2502 * set the uptodate bits if things worked
2503 * set the page up to date if all extents in the tree are uptodate
2504 * clear the lock bit in the extent tree
2505 * unlock the page if there are no other extents locked for it
2507 * Scheduling is not allowed, so the extent state tree is expected
2508 * to have one and only one object corresponding to this IO.
2510 static void end_bio_extent_readpage(struct bio
*bio
)
2512 struct bio_vec
*bvec
;
2513 int uptodate
= !bio
->bi_status
;
2514 struct btrfs_io_bio
*io_bio
= btrfs_io_bio(bio
);
2515 struct extent_io_tree
*tree
, *failure_tree
;
2520 u64 extent_start
= 0;
2526 ASSERT(!bio_flagged(bio
, BIO_CLONED
));
2527 bio_for_each_segment_all(bvec
, bio
, i
) {
2528 struct page
*page
= bvec
->bv_page
;
2529 struct inode
*inode
= page
->mapping
->host
;
2530 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2532 btrfs_debug(fs_info
,
2533 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2534 (u64
)bio
->bi_iter
.bi_sector
, bio
->bi_status
,
2535 io_bio
->mirror_num
);
2536 tree
= &BTRFS_I(inode
)->io_tree
;
2537 failure_tree
= &BTRFS_I(inode
)->io_failure_tree
;
2539 /* We always issue full-page reads, but if some block
2540 * in a page fails to read, blk_update_request() will
2541 * advance bv_offset and adjust bv_len to compensate.
2542 * Print a warning for nonzero offsets, and an error
2543 * if they don't add up to a full page. */
2544 if (bvec
->bv_offset
|| bvec
->bv_len
!= PAGE_SIZE
) {
2545 if (bvec
->bv_offset
+ bvec
->bv_len
!= PAGE_SIZE
)
2547 "partial page read in btrfs with offset %u and length %u",
2548 bvec
->bv_offset
, bvec
->bv_len
);
2551 "incomplete page read in btrfs with offset %u and length %u",
2552 bvec
->bv_offset
, bvec
->bv_len
);
2555 start
= page_offset(page
);
2556 end
= start
+ bvec
->bv_offset
+ bvec
->bv_len
- 1;
2559 mirror
= io_bio
->mirror_num
;
2560 if (likely(uptodate
&& tree
->ops
)) {
2561 ret
= tree
->ops
->readpage_end_io_hook(io_bio
, offset
,
2567 clean_io_failure(BTRFS_I(inode
)->root
->fs_info
,
2568 failure_tree
, tree
, start
,
2570 btrfs_ino(BTRFS_I(inode
)), 0);
2573 if (likely(uptodate
))
2577 ret
= tree
->ops
->readpage_io_failed_hook(page
, mirror
);
2578 if (ret
== -EAGAIN
) {
2580 * Data inode's readpage_io_failed_hook() always
2583 * The generic bio_readpage_error handles errors
2584 * the following way: If possible, new read
2585 * requests are created and submitted and will
2586 * end up in end_bio_extent_readpage as well (if
2587 * we're lucky, not in the !uptodate case). In
2588 * that case it returns 0 and we just go on with
2589 * the next page in our bio. If it can't handle
2590 * the error it will return -EIO and we remain
2591 * responsible for that page.
2593 ret
= bio_readpage_error(bio
, offset
, page
,
2594 start
, end
, mirror
);
2596 uptodate
= !bio
->bi_status
;
2603 * metadata's readpage_io_failed_hook() always returns
2604 * -EIO and fixes nothing. -EIO is also returned if
2605 * data inode error could not be fixed.
2607 ASSERT(ret
== -EIO
);
2610 if (likely(uptodate
)) {
2611 loff_t i_size
= i_size_read(inode
);
2612 pgoff_t end_index
= i_size
>> PAGE_SHIFT
;
2615 /* Zero out the end if this page straddles i_size */
2616 off
= i_size
& (PAGE_SIZE
-1);
2617 if (page
->index
== end_index
&& off
)
2618 zero_user_segment(page
, off
, PAGE_SIZE
);
2619 SetPageUptodate(page
);
2621 ClearPageUptodate(page
);
2627 if (unlikely(!uptodate
)) {
2629 endio_readpage_release_extent(tree
,
2635 endio_readpage_release_extent(tree
, start
,
2636 end
- start
+ 1, 0);
2637 } else if (!extent_len
) {
2638 extent_start
= start
;
2639 extent_len
= end
+ 1 - start
;
2640 } else if (extent_start
+ extent_len
== start
) {
2641 extent_len
+= end
+ 1 - start
;
2643 endio_readpage_release_extent(tree
, extent_start
,
2644 extent_len
, uptodate
);
2645 extent_start
= start
;
2646 extent_len
= end
+ 1 - start
;
2651 endio_readpage_release_extent(tree
, extent_start
, extent_len
,
2654 io_bio
->end_io(io_bio
, blk_status_to_errno(bio
->bi_status
));
2659 * Initialize the members up to but not including 'bio'. Use after allocating a
2660 * new bio by bio_alloc_bioset as it does not initialize the bytes outside of
2661 * 'bio' because use of __GFP_ZERO is not supported.
2663 static inline void btrfs_io_bio_init(struct btrfs_io_bio
*btrfs_bio
)
2665 memset(btrfs_bio
, 0, offsetof(struct btrfs_io_bio
, bio
));
2669 * The following helpers allocate a bio. As it's backed by a bioset, it'll
2670 * never fail. We're returning a bio right now but you can call btrfs_io_bio
2671 * for the appropriate container_of magic
2673 struct bio
*btrfs_bio_alloc(struct block_device
*bdev
, u64 first_byte
)
2677 bio
= bio_alloc_bioset(GFP_NOFS
, BIO_MAX_PAGES
, btrfs_bioset
);
2678 bio_set_dev(bio
, bdev
);
2679 bio
->bi_iter
.bi_sector
= first_byte
>> 9;
2680 btrfs_io_bio_init(btrfs_io_bio(bio
));
2684 struct bio
*btrfs_bio_clone(struct bio
*bio
)
2686 struct btrfs_io_bio
*btrfs_bio
;
2689 /* Bio allocation backed by a bioset does not fail */
2690 new = bio_clone_fast(bio
, GFP_NOFS
, btrfs_bioset
);
2691 btrfs_bio
= btrfs_io_bio(new);
2692 btrfs_io_bio_init(btrfs_bio
);
2693 btrfs_bio
->iter
= bio
->bi_iter
;
2697 struct bio
*btrfs_io_bio_alloc(unsigned int nr_iovecs
)
2701 /* Bio allocation backed by a bioset does not fail */
2702 bio
= bio_alloc_bioset(GFP_NOFS
, nr_iovecs
, btrfs_bioset
);
2703 btrfs_io_bio_init(btrfs_io_bio(bio
));
2707 struct bio
*btrfs_bio_clone_partial(struct bio
*orig
, int offset
, int size
)
2710 struct btrfs_io_bio
*btrfs_bio
;
2712 /* this will never fail when it's backed by a bioset */
2713 bio
= bio_clone_fast(orig
, GFP_NOFS
, btrfs_bioset
);
2716 btrfs_bio
= btrfs_io_bio(bio
);
2717 btrfs_io_bio_init(btrfs_bio
);
2719 bio_trim(bio
, offset
>> 9, size
>> 9);
2720 btrfs_bio
->iter
= bio
->bi_iter
;
2724 static int __must_check
submit_one_bio(struct bio
*bio
, int mirror_num
,
2725 unsigned long bio_flags
)
2727 blk_status_t ret
= 0;
2728 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
2729 struct page
*page
= bvec
->bv_page
;
2730 struct extent_io_tree
*tree
= bio
->bi_private
;
2733 start
= page_offset(page
) + bvec
->bv_offset
;
2735 bio
->bi_private
= NULL
;
2739 ret
= tree
->ops
->submit_bio_hook(tree
->private_data
, bio
,
2740 mirror_num
, bio_flags
, start
);
2742 btrfsic_submit_bio(bio
);
2745 return blk_status_to_errno(ret
);
2748 static int merge_bio(struct extent_io_tree
*tree
, struct page
*page
,
2749 unsigned long offset
, size_t size
, struct bio
*bio
,
2750 unsigned long bio_flags
)
2754 ret
= tree
->ops
->merge_bio_hook(page
, offset
, size
, bio
,
2761 * @opf: bio REQ_OP_* and REQ_* flags as one value
2763 static int submit_extent_page(unsigned int opf
, struct extent_io_tree
*tree
,
2764 struct writeback_control
*wbc
,
2765 struct page
*page
, sector_t sector
,
2766 size_t size
, unsigned long offset
,
2767 struct block_device
*bdev
,
2768 struct bio
**bio_ret
,
2769 bio_end_io_t end_io_func
,
2771 unsigned long prev_bio_flags
,
2772 unsigned long bio_flags
,
2773 bool force_bio_submit
)
2778 int old_compressed
= prev_bio_flags
& EXTENT_BIO_COMPRESSED
;
2779 size_t page_size
= min_t(size_t, size
, PAGE_SIZE
);
2781 if (bio_ret
&& *bio_ret
) {
2784 contig
= bio
->bi_iter
.bi_sector
== sector
;
2786 contig
= bio_end_sector(bio
) == sector
;
2788 if (prev_bio_flags
!= bio_flags
|| !contig
||
2790 merge_bio(tree
, page
, offset
, page_size
, bio
, bio_flags
) ||
2791 bio_add_page(bio
, page
, page_size
, offset
) < page_size
) {
2792 ret
= submit_one_bio(bio
, mirror_num
, prev_bio_flags
);
2800 wbc_account_io(wbc
, page
, page_size
);
2805 bio
= btrfs_bio_alloc(bdev
, (u64
)sector
<< 9);
2806 bio_add_page(bio
, page
, page_size
, offset
);
2807 bio
->bi_end_io
= end_io_func
;
2808 bio
->bi_private
= tree
;
2809 bio
->bi_write_hint
= page
->mapping
->host
->i_write_hint
;
2812 wbc_init_bio(wbc
, bio
);
2813 wbc_account_io(wbc
, page
, page_size
);
2819 ret
= submit_one_bio(bio
, mirror_num
, bio_flags
);
2824 static void attach_extent_buffer_page(struct extent_buffer
*eb
,
2827 if (!PagePrivate(page
)) {
2828 SetPagePrivate(page
);
2830 set_page_private(page
, (unsigned long)eb
);
2832 WARN_ON(page
->private != (unsigned long)eb
);
2836 void set_page_extent_mapped(struct page
*page
)
2838 if (!PagePrivate(page
)) {
2839 SetPagePrivate(page
);
2841 set_page_private(page
, EXTENT_PAGE_PRIVATE
);
2845 static struct extent_map
*
2846 __get_extent_map(struct inode
*inode
, struct page
*page
, size_t pg_offset
,
2847 u64 start
, u64 len
, get_extent_t
*get_extent
,
2848 struct extent_map
**em_cached
)
2850 struct extent_map
*em
;
2852 if (em_cached
&& *em_cached
) {
2854 if (extent_map_in_tree(em
) && start
>= em
->start
&&
2855 start
< extent_map_end(em
)) {
2856 refcount_inc(&em
->refs
);
2860 free_extent_map(em
);
2864 em
= get_extent(BTRFS_I(inode
), page
, pg_offset
, start
, len
, 0);
2865 if (em_cached
&& !IS_ERR_OR_NULL(em
)) {
2867 refcount_inc(&em
->refs
);
2873 * basic readpage implementation. Locked extent state structs are inserted
2874 * into the tree that are removed when the IO is done (by the end_io
2876 * XXX JDM: This needs looking at to ensure proper page locking
2877 * return 0 on success, otherwise return error
2879 static int __do_readpage(struct extent_io_tree
*tree
,
2881 get_extent_t
*get_extent
,
2882 struct extent_map
**em_cached
,
2883 struct bio
**bio
, int mirror_num
,
2884 unsigned long *bio_flags
, unsigned int read_flags
,
2887 struct inode
*inode
= page
->mapping
->host
;
2888 u64 start
= page_offset(page
);
2889 u64 page_end
= start
+ PAGE_SIZE
- 1;
2893 u64 last_byte
= i_size_read(inode
);
2897 struct extent_map
*em
;
2898 struct block_device
*bdev
;
2901 size_t pg_offset
= 0;
2903 size_t disk_io_size
;
2904 size_t blocksize
= inode
->i_sb
->s_blocksize
;
2905 unsigned long this_bio_flag
= 0;
2907 set_page_extent_mapped(page
);
2910 if (!PageUptodate(page
)) {
2911 if (cleancache_get_page(page
) == 0) {
2912 BUG_ON(blocksize
!= PAGE_SIZE
);
2913 unlock_extent(tree
, start
, end
);
2918 if (page
->index
== last_byte
>> PAGE_SHIFT
) {
2920 size_t zero_offset
= last_byte
& (PAGE_SIZE
- 1);
2923 iosize
= PAGE_SIZE
- zero_offset
;
2924 userpage
= kmap_atomic(page
);
2925 memset(userpage
+ zero_offset
, 0, iosize
);
2926 flush_dcache_page(page
);
2927 kunmap_atomic(userpage
);
2930 while (cur
<= end
) {
2931 bool force_bio_submit
= false;
2933 if (cur
>= last_byte
) {
2935 struct extent_state
*cached
= NULL
;
2937 iosize
= PAGE_SIZE
- pg_offset
;
2938 userpage
= kmap_atomic(page
);
2939 memset(userpage
+ pg_offset
, 0, iosize
);
2940 flush_dcache_page(page
);
2941 kunmap_atomic(userpage
);
2942 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
2944 unlock_extent_cached(tree
, cur
,
2949 em
= __get_extent_map(inode
, page
, pg_offset
, cur
,
2950 end
- cur
+ 1, get_extent
, em_cached
);
2951 if (IS_ERR_OR_NULL(em
)) {
2953 unlock_extent(tree
, cur
, end
);
2956 extent_offset
= cur
- em
->start
;
2957 BUG_ON(extent_map_end(em
) <= cur
);
2960 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
)) {
2961 this_bio_flag
|= EXTENT_BIO_COMPRESSED
;
2962 extent_set_compress_type(&this_bio_flag
,
2966 iosize
= min(extent_map_end(em
) - cur
, end
- cur
+ 1);
2967 cur_end
= min(extent_map_end(em
) - 1, end
);
2968 iosize
= ALIGN(iosize
, blocksize
);
2969 if (this_bio_flag
& EXTENT_BIO_COMPRESSED
) {
2970 disk_io_size
= em
->block_len
;
2971 sector
= em
->block_start
>> 9;
2973 sector
= (em
->block_start
+ extent_offset
) >> 9;
2974 disk_io_size
= iosize
;
2977 block_start
= em
->block_start
;
2978 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
2979 block_start
= EXTENT_MAP_HOLE
;
2982 * If we have a file range that points to a compressed extent
2983 * and it's followed by a consecutive file range that points to
2984 * to the same compressed extent (possibly with a different
2985 * offset and/or length, so it either points to the whole extent
2986 * or only part of it), we must make sure we do not submit a
2987 * single bio to populate the pages for the 2 ranges because
2988 * this makes the compressed extent read zero out the pages
2989 * belonging to the 2nd range. Imagine the following scenario:
2992 * [0 - 8K] [8K - 24K]
2995 * points to extent X, points to extent X,
2996 * offset 4K, length of 8K offset 0, length 16K
2998 * [extent X, compressed length = 4K uncompressed length = 16K]
3000 * If the bio to read the compressed extent covers both ranges,
3001 * it will decompress extent X into the pages belonging to the
3002 * first range and then it will stop, zeroing out the remaining
3003 * pages that belong to the other range that points to extent X.
3004 * So here we make sure we submit 2 bios, one for the first
3005 * range and another one for the third range. Both will target
3006 * the same physical extent from disk, but we can't currently
3007 * make the compressed bio endio callback populate the pages
3008 * for both ranges because each compressed bio is tightly
3009 * coupled with a single extent map, and each range can have
3010 * an extent map with a different offset value relative to the
3011 * uncompressed data of our extent and different lengths. This
3012 * is a corner case so we prioritize correctness over
3013 * non-optimal behavior (submitting 2 bios for the same extent).
3015 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
) &&
3016 prev_em_start
&& *prev_em_start
!= (u64
)-1 &&
3017 *prev_em_start
!= em
->orig_start
)
3018 force_bio_submit
= true;
3021 *prev_em_start
= em
->orig_start
;
3023 free_extent_map(em
);
3026 /* we've found a hole, just zero and go on */
3027 if (block_start
== EXTENT_MAP_HOLE
) {
3029 struct extent_state
*cached
= NULL
;
3031 userpage
= kmap_atomic(page
);
3032 memset(userpage
+ pg_offset
, 0, iosize
);
3033 flush_dcache_page(page
);
3034 kunmap_atomic(userpage
);
3036 set_extent_uptodate(tree
, cur
, cur
+ iosize
- 1,
3038 unlock_extent_cached(tree
, cur
,
3042 pg_offset
+= iosize
;
3045 /* the get_extent function already copied into the page */
3046 if (test_range_bit(tree
, cur
, cur_end
,
3047 EXTENT_UPTODATE
, 1, NULL
)) {
3048 check_page_uptodate(tree
, page
);
3049 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3051 pg_offset
+= iosize
;
3054 /* we have an inline extent but it didn't get marked up
3055 * to date. Error out
3057 if (block_start
== EXTENT_MAP_INLINE
) {
3059 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3061 pg_offset
+= iosize
;
3065 ret
= submit_extent_page(REQ_OP_READ
| read_flags
, tree
, NULL
,
3066 page
, sector
, disk_io_size
, pg_offset
,
3068 end_bio_extent_readpage
, mirror_num
,
3074 *bio_flags
= this_bio_flag
;
3077 unlock_extent(tree
, cur
, cur
+ iosize
- 1);
3081 pg_offset
+= iosize
;
3085 if (!PageError(page
))
3086 SetPageUptodate(page
);
3092 static inline void __do_contiguous_readpages(struct extent_io_tree
*tree
,
3093 struct page
*pages
[], int nr_pages
,
3095 get_extent_t
*get_extent
,
3096 struct extent_map
**em_cached
,
3097 struct bio
**bio
, int mirror_num
,
3098 unsigned long *bio_flags
,
3101 struct inode
*inode
;
3102 struct btrfs_ordered_extent
*ordered
;
3105 inode
= pages
[0]->mapping
->host
;
3107 lock_extent(tree
, start
, end
);
3108 ordered
= btrfs_lookup_ordered_range(BTRFS_I(inode
), start
,
3112 unlock_extent(tree
, start
, end
);
3113 btrfs_start_ordered_extent(inode
, ordered
, 1);
3114 btrfs_put_ordered_extent(ordered
);
3117 for (index
= 0; index
< nr_pages
; index
++) {
3118 __do_readpage(tree
, pages
[index
], get_extent
, em_cached
, bio
,
3119 mirror_num
, bio_flags
, 0, prev_em_start
);
3120 put_page(pages
[index
]);
3124 static void __extent_readpages(struct extent_io_tree
*tree
,
3125 struct page
*pages
[],
3126 int nr_pages
, get_extent_t
*get_extent
,
3127 struct extent_map
**em_cached
,
3128 struct bio
**bio
, int mirror_num
,
3129 unsigned long *bio_flags
,
3136 int first_index
= 0;
3138 for (index
= 0; index
< nr_pages
; index
++) {
3139 page_start
= page_offset(pages
[index
]);
3142 end
= start
+ PAGE_SIZE
- 1;
3143 first_index
= index
;
3144 } else if (end
+ 1 == page_start
) {
3147 __do_contiguous_readpages(tree
, &pages
[first_index
],
3148 index
- first_index
, start
,
3149 end
, get_extent
, em_cached
,
3150 bio
, mirror_num
, bio_flags
,
3153 end
= start
+ PAGE_SIZE
- 1;
3154 first_index
= index
;
3159 __do_contiguous_readpages(tree
, &pages
[first_index
],
3160 index
- first_index
, start
,
3161 end
, get_extent
, em_cached
, bio
,
3162 mirror_num
, bio_flags
,
3166 static int __extent_read_full_page(struct extent_io_tree
*tree
,
3168 get_extent_t
*get_extent
,
3169 struct bio
**bio
, int mirror_num
,
3170 unsigned long *bio_flags
,
3171 unsigned int read_flags
)
3173 struct inode
*inode
= page
->mapping
->host
;
3174 struct btrfs_ordered_extent
*ordered
;
3175 u64 start
= page_offset(page
);
3176 u64 end
= start
+ PAGE_SIZE
- 1;
3180 lock_extent(tree
, start
, end
);
3181 ordered
= btrfs_lookup_ordered_range(BTRFS_I(inode
), start
,
3185 unlock_extent(tree
, start
, end
);
3186 btrfs_start_ordered_extent(inode
, ordered
, 1);
3187 btrfs_put_ordered_extent(ordered
);
3190 ret
= __do_readpage(tree
, page
, get_extent
, NULL
, bio
, mirror_num
,
3191 bio_flags
, read_flags
, NULL
);
3195 int extent_read_full_page(struct extent_io_tree
*tree
, struct page
*page
,
3196 get_extent_t
*get_extent
, int mirror_num
)
3198 struct bio
*bio
= NULL
;
3199 unsigned long bio_flags
= 0;
3202 ret
= __extent_read_full_page(tree
, page
, get_extent
, &bio
, mirror_num
,
3205 ret
= submit_one_bio(bio
, mirror_num
, bio_flags
);
3209 static void update_nr_written(struct writeback_control
*wbc
,
3210 unsigned long nr_written
)
3212 wbc
->nr_to_write
-= nr_written
;
3216 * helper for __extent_writepage, doing all of the delayed allocation setup.
3218 * This returns 1 if our fill_delalloc function did all the work required
3219 * to write the page (copy into inline extent). In this case the IO has
3220 * been started and the page is already unlocked.
3222 * This returns 0 if all went well (page still locked)
3223 * This returns < 0 if there were errors (page still locked)
3225 static noinline_for_stack
int writepage_delalloc(struct inode
*inode
,
3226 struct page
*page
, struct writeback_control
*wbc
,
3227 struct extent_page_data
*epd
,
3229 unsigned long *nr_written
)
3231 struct extent_io_tree
*tree
= epd
->tree
;
3232 u64 page_end
= delalloc_start
+ PAGE_SIZE
- 1;
3234 u64 delalloc_to_write
= 0;
3235 u64 delalloc_end
= 0;
3237 int page_started
= 0;
3239 if (epd
->extent_locked
|| !tree
->ops
|| !tree
->ops
->fill_delalloc
)
3242 while (delalloc_end
< page_end
) {
3243 nr_delalloc
= find_lock_delalloc_range(inode
, tree
,
3247 BTRFS_MAX_EXTENT_SIZE
);
3248 if (nr_delalloc
== 0) {
3249 delalloc_start
= delalloc_end
+ 1;
3252 ret
= tree
->ops
->fill_delalloc(inode
, page
,
3257 /* File system has been set read-only */
3260 /* fill_delalloc should be return < 0 for error
3261 * but just in case, we use > 0 here meaning the
3262 * IO is started, so we don't want to return > 0
3263 * unless things are going well.
3265 ret
= ret
< 0 ? ret
: -EIO
;
3269 * delalloc_end is already one less than the total length, so
3270 * we don't subtract one from PAGE_SIZE
3272 delalloc_to_write
+= (delalloc_end
- delalloc_start
+
3273 PAGE_SIZE
) >> PAGE_SHIFT
;
3274 delalloc_start
= delalloc_end
+ 1;
3276 if (wbc
->nr_to_write
< delalloc_to_write
) {
3279 if (delalloc_to_write
< thresh
* 2)
3280 thresh
= delalloc_to_write
;
3281 wbc
->nr_to_write
= min_t(u64
, delalloc_to_write
,
3285 /* did the fill delalloc function already unlock and start
3290 * we've unlocked the page, so we can't update
3291 * the mapping's writeback index, just update
3294 wbc
->nr_to_write
-= *nr_written
;
3305 * helper for __extent_writepage. This calls the writepage start hooks,
3306 * and does the loop to map the page into extents and bios.
3308 * We return 1 if the IO is started and the page is unlocked,
3309 * 0 if all went well (page still locked)
3310 * < 0 if there were errors (page still locked)
3312 static noinline_for_stack
int __extent_writepage_io(struct inode
*inode
,
3314 struct writeback_control
*wbc
,
3315 struct extent_page_data
*epd
,
3317 unsigned long nr_written
,
3318 unsigned int write_flags
, int *nr_ret
)
3320 struct extent_io_tree
*tree
= epd
->tree
;
3321 u64 start
= page_offset(page
);
3322 u64 page_end
= start
+ PAGE_SIZE
- 1;
3329 struct extent_map
*em
;
3330 struct block_device
*bdev
;
3331 size_t pg_offset
= 0;
3337 if (tree
->ops
&& tree
->ops
->writepage_start_hook
) {
3338 ret
= tree
->ops
->writepage_start_hook(page
, start
,
3341 /* Fixup worker will requeue */
3343 wbc
->pages_skipped
++;
3345 redirty_page_for_writepage(wbc
, page
);
3347 update_nr_written(wbc
, nr_written
);
3354 * we don't want to touch the inode after unlocking the page,
3355 * so we update the mapping writeback index now
3357 update_nr_written(wbc
, nr_written
+ 1);
3360 if (i_size
<= start
) {
3361 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3362 tree
->ops
->writepage_end_io_hook(page
, start
,
3367 blocksize
= inode
->i_sb
->s_blocksize
;
3369 while (cur
<= end
) {
3372 if (cur
>= i_size
) {
3373 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
3374 tree
->ops
->writepage_end_io_hook(page
, cur
,
3378 em
= epd
->get_extent(BTRFS_I(inode
), page
, pg_offset
, cur
,
3380 if (IS_ERR_OR_NULL(em
)) {
3382 ret
= PTR_ERR_OR_ZERO(em
);
3386 extent_offset
= cur
- em
->start
;
3387 em_end
= extent_map_end(em
);
3388 BUG_ON(em_end
<= cur
);
3390 iosize
= min(em_end
- cur
, end
- cur
+ 1);
3391 iosize
= ALIGN(iosize
, blocksize
);
3392 sector
= (em
->block_start
+ extent_offset
) >> 9;
3394 block_start
= em
->block_start
;
3395 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
3396 free_extent_map(em
);
3400 * compressed and inline extents are written through other
3403 if (compressed
|| block_start
== EXTENT_MAP_HOLE
||
3404 block_start
== EXTENT_MAP_INLINE
) {
3406 * end_io notification does not happen here for
3407 * compressed extents
3409 if (!compressed
&& tree
->ops
&&
3410 tree
->ops
->writepage_end_io_hook
)
3411 tree
->ops
->writepage_end_io_hook(page
, cur
,
3414 else if (compressed
) {
3415 /* we don't want to end_page_writeback on
3416 * a compressed extent. this happens
3423 pg_offset
+= iosize
;
3427 set_range_writeback(tree
, cur
, cur
+ iosize
- 1);
3428 if (!PageWriteback(page
)) {
3429 btrfs_err(BTRFS_I(inode
)->root
->fs_info
,
3430 "page %lu not writeback, cur %llu end %llu",
3431 page
->index
, cur
, end
);
3434 ret
= submit_extent_page(REQ_OP_WRITE
| write_flags
, tree
, wbc
,
3435 page
, sector
, iosize
, pg_offset
,
3437 end_bio_extent_writepage
,
3441 if (PageWriteback(page
))
3442 end_page_writeback(page
);
3446 pg_offset
+= iosize
;
3455 * the writepage semantics are similar to regular writepage. extent
3456 * records are inserted to lock ranges in the tree, and as dirty areas
3457 * are found, they are marked writeback. Then the lock bits are removed
3458 * and the end_io handler clears the writeback ranges
3460 static int __extent_writepage(struct page
*page
, struct writeback_control
*wbc
,
3463 struct inode
*inode
= page
->mapping
->host
;
3464 struct extent_page_data
*epd
= data
;
3465 u64 start
= page_offset(page
);
3466 u64 page_end
= start
+ PAGE_SIZE
- 1;
3469 size_t pg_offset
= 0;
3470 loff_t i_size
= i_size_read(inode
);
3471 unsigned long end_index
= i_size
>> PAGE_SHIFT
;
3472 unsigned int write_flags
= 0;
3473 unsigned long nr_written
= 0;
3475 write_flags
= wbc_to_write_flags(wbc
);
3477 trace___extent_writepage(page
, inode
, wbc
);
3479 WARN_ON(!PageLocked(page
));
3481 ClearPageError(page
);
3483 pg_offset
= i_size
& (PAGE_SIZE
- 1);
3484 if (page
->index
> end_index
||
3485 (page
->index
== end_index
&& !pg_offset
)) {
3486 page
->mapping
->a_ops
->invalidatepage(page
, 0, PAGE_SIZE
);
3491 if (page
->index
== end_index
) {
3494 userpage
= kmap_atomic(page
);
3495 memset(userpage
+ pg_offset
, 0,
3496 PAGE_SIZE
- pg_offset
);
3497 kunmap_atomic(userpage
);
3498 flush_dcache_page(page
);
3503 set_page_extent_mapped(page
);
3505 ret
= writepage_delalloc(inode
, page
, wbc
, epd
, start
, &nr_written
);
3511 ret
= __extent_writepage_io(inode
, page
, wbc
, epd
,
3512 i_size
, nr_written
, write_flags
, &nr
);
3518 /* make sure the mapping tag for page dirty gets cleared */
3519 set_page_writeback(page
);
3520 end_page_writeback(page
);
3522 if (PageError(page
)) {
3523 ret
= ret
< 0 ? ret
: -EIO
;
3524 end_extent_writepage(page
, ret
, start
, page_end
);
3533 void wait_on_extent_buffer_writeback(struct extent_buffer
*eb
)
3535 wait_on_bit_io(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
,
3536 TASK_UNINTERRUPTIBLE
);
3539 static noinline_for_stack
int
3540 lock_extent_buffer_for_io(struct extent_buffer
*eb
,
3541 struct btrfs_fs_info
*fs_info
,
3542 struct extent_page_data
*epd
)
3544 unsigned long i
, num_pages
;
3548 if (!btrfs_try_tree_write_lock(eb
)) {
3550 flush_write_bio(epd
);
3551 btrfs_tree_lock(eb
);
3554 if (test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
)) {
3555 btrfs_tree_unlock(eb
);
3559 flush_write_bio(epd
);
3563 wait_on_extent_buffer_writeback(eb
);
3564 btrfs_tree_lock(eb
);
3565 if (!test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
))
3567 btrfs_tree_unlock(eb
);
3572 * We need to do this to prevent races in people who check if the eb is
3573 * under IO since we can end up having no IO bits set for a short period
3576 spin_lock(&eb
->refs_lock
);
3577 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
)) {
3578 set_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3579 spin_unlock(&eb
->refs_lock
);
3580 btrfs_set_header_flag(eb
, BTRFS_HEADER_FLAG_WRITTEN
);
3581 percpu_counter_add_batch(&fs_info
->dirty_metadata_bytes
,
3583 fs_info
->dirty_metadata_batch
);
3586 spin_unlock(&eb
->refs_lock
);
3589 btrfs_tree_unlock(eb
);
3594 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3595 for (i
= 0; i
< num_pages
; i
++) {
3596 struct page
*p
= eb
->pages
[i
];
3598 if (!trylock_page(p
)) {
3600 flush_write_bio(epd
);
3610 static void end_extent_buffer_writeback(struct extent_buffer
*eb
)
3612 clear_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
);
3613 smp_mb__after_atomic();
3614 wake_up_bit(&eb
->bflags
, EXTENT_BUFFER_WRITEBACK
);
3617 static void set_btree_ioerr(struct page
*page
)
3619 struct extent_buffer
*eb
= (struct extent_buffer
*)page
->private;
3622 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
))
3626 * If writeback for a btree extent that doesn't belong to a log tree
3627 * failed, increment the counter transaction->eb_write_errors.
3628 * We do this because while the transaction is running and before it's
3629 * committing (when we call filemap_fdata[write|wait]_range against
3630 * the btree inode), we might have
3631 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3632 * returns an error or an error happens during writeback, when we're
3633 * committing the transaction we wouldn't know about it, since the pages
3634 * can be no longer dirty nor marked anymore for writeback (if a
3635 * subsequent modification to the extent buffer didn't happen before the
3636 * transaction commit), which makes filemap_fdata[write|wait]_range not
3637 * able to find the pages tagged with SetPageError at transaction
3638 * commit time. So if this happens we must abort the transaction,
3639 * otherwise we commit a super block with btree roots that point to
3640 * btree nodes/leafs whose content on disk is invalid - either garbage
3641 * or the content of some node/leaf from a past generation that got
3642 * cowed or deleted and is no longer valid.
3644 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3645 * not be enough - we need to distinguish between log tree extents vs
3646 * non-log tree extents, and the next filemap_fdatawait_range() call
3647 * will catch and clear such errors in the mapping - and that call might
3648 * be from a log sync and not from a transaction commit. Also, checking
3649 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3650 * not done and would not be reliable - the eb might have been released
3651 * from memory and reading it back again means that flag would not be
3652 * set (since it's a runtime flag, not persisted on disk).
3654 * Using the flags below in the btree inode also makes us achieve the
3655 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3656 * writeback for all dirty pages and before filemap_fdatawait_range()
3657 * is called, the writeback for all dirty pages had already finished
3658 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3659 * filemap_fdatawait_range() would return success, as it could not know
3660 * that writeback errors happened (the pages were no longer tagged for
3663 switch (eb
->log_index
) {
3665 set_bit(BTRFS_FS_BTREE_ERR
, &eb
->fs_info
->flags
);
3668 set_bit(BTRFS_FS_LOG1_ERR
, &eb
->fs_info
->flags
);
3671 set_bit(BTRFS_FS_LOG2_ERR
, &eb
->fs_info
->flags
);
3674 BUG(); /* unexpected, logic error */
3678 static void end_bio_extent_buffer_writepage(struct bio
*bio
)
3680 struct bio_vec
*bvec
;
3681 struct extent_buffer
*eb
;
3684 ASSERT(!bio_flagged(bio
, BIO_CLONED
));
3685 bio_for_each_segment_all(bvec
, bio
, i
) {
3686 struct page
*page
= bvec
->bv_page
;
3688 eb
= (struct extent_buffer
*)page
->private;
3690 done
= atomic_dec_and_test(&eb
->io_pages
);
3692 if (bio
->bi_status
||
3693 test_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
)) {
3694 ClearPageUptodate(page
);
3695 set_btree_ioerr(page
);
3698 end_page_writeback(page
);
3703 end_extent_buffer_writeback(eb
);
3709 static noinline_for_stack
int write_one_eb(struct extent_buffer
*eb
,
3710 struct btrfs_fs_info
*fs_info
,
3711 struct writeback_control
*wbc
,
3712 struct extent_page_data
*epd
)
3714 struct block_device
*bdev
= fs_info
->fs_devices
->latest_bdev
;
3715 struct extent_io_tree
*tree
= &BTRFS_I(fs_info
->btree_inode
)->io_tree
;
3716 u64 offset
= eb
->start
;
3718 unsigned long i
, num_pages
;
3719 unsigned long bio_flags
= 0;
3720 unsigned long start
, end
;
3721 unsigned int write_flags
= wbc_to_write_flags(wbc
) | REQ_META
;
3724 clear_bit(EXTENT_BUFFER_WRITE_ERR
, &eb
->bflags
);
3725 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
3726 atomic_set(&eb
->io_pages
, num_pages
);
3727 if (btrfs_header_owner(eb
) == BTRFS_TREE_LOG_OBJECTID
)
3728 bio_flags
= EXTENT_BIO_TREE_LOG
;
3730 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3731 nritems
= btrfs_header_nritems(eb
);
3732 if (btrfs_header_level(eb
) > 0) {
3733 end
= btrfs_node_key_ptr_offset(nritems
);
3735 memzero_extent_buffer(eb
, end
, eb
->len
- end
);
3739 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3741 start
= btrfs_item_nr_offset(nritems
);
3742 end
= BTRFS_LEAF_DATA_OFFSET
+ leaf_data_end(fs_info
, eb
);
3743 memzero_extent_buffer(eb
, start
, end
- start
);
3746 for (i
= 0; i
< num_pages
; i
++) {
3747 struct page
*p
= eb
->pages
[i
];
3749 clear_page_dirty_for_io(p
);
3750 set_page_writeback(p
);
3751 ret
= submit_extent_page(REQ_OP_WRITE
| write_flags
, tree
, wbc
,
3752 p
, offset
>> 9, PAGE_SIZE
, 0, bdev
,
3754 end_bio_extent_buffer_writepage
,
3755 0, epd
->bio_flags
, bio_flags
, false);
3756 epd
->bio_flags
= bio_flags
;
3759 if (PageWriteback(p
))
3760 end_page_writeback(p
);
3761 if (atomic_sub_and_test(num_pages
- i
, &eb
->io_pages
))
3762 end_extent_buffer_writeback(eb
);
3766 offset
+= PAGE_SIZE
;
3767 update_nr_written(wbc
, 1);
3771 if (unlikely(ret
)) {
3772 for (; i
< num_pages
; i
++) {
3773 struct page
*p
= eb
->pages
[i
];
3774 clear_page_dirty_for_io(p
);
3782 int btree_write_cache_pages(struct address_space
*mapping
,
3783 struct writeback_control
*wbc
)
3785 struct extent_io_tree
*tree
= &BTRFS_I(mapping
->host
)->io_tree
;
3786 struct btrfs_fs_info
*fs_info
= BTRFS_I(mapping
->host
)->root
->fs_info
;
3787 struct extent_buffer
*eb
, *prev_eb
= NULL
;
3788 struct extent_page_data epd
= {
3792 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
3797 int nr_to_write_done
= 0;
3798 struct pagevec pvec
;
3801 pgoff_t end
; /* Inclusive */
3805 pagevec_init(&pvec
, 0);
3806 if (wbc
->range_cyclic
) {
3807 index
= mapping
->writeback_index
; /* Start from prev offset */
3810 index
= wbc
->range_start
>> PAGE_SHIFT
;
3811 end
= wbc
->range_end
>> PAGE_SHIFT
;
3814 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3815 tag
= PAGECACHE_TAG_TOWRITE
;
3817 tag
= PAGECACHE_TAG_DIRTY
;
3819 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3820 tag_pages_for_writeback(mapping
, index
, end
);
3821 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3822 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3823 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3827 for (i
= 0; i
< nr_pages
; i
++) {
3828 struct page
*page
= pvec
.pages
[i
];
3830 if (!PagePrivate(page
))
3833 if (!wbc
->range_cyclic
&& page
->index
> end
) {
3838 spin_lock(&mapping
->private_lock
);
3839 if (!PagePrivate(page
)) {
3840 spin_unlock(&mapping
->private_lock
);
3844 eb
= (struct extent_buffer
*)page
->private;
3847 * Shouldn't happen and normally this would be a BUG_ON
3848 * but no sense in crashing the users box for something
3849 * we can survive anyway.
3852 spin_unlock(&mapping
->private_lock
);
3856 if (eb
== prev_eb
) {
3857 spin_unlock(&mapping
->private_lock
);
3861 ret
= atomic_inc_not_zero(&eb
->refs
);
3862 spin_unlock(&mapping
->private_lock
);
3867 ret
= lock_extent_buffer_for_io(eb
, fs_info
, &epd
);
3869 free_extent_buffer(eb
);
3873 ret
= write_one_eb(eb
, fs_info
, wbc
, &epd
);
3876 free_extent_buffer(eb
);
3879 free_extent_buffer(eb
);
3882 * the filesystem may choose to bump up nr_to_write.
3883 * We have to make sure to honor the new nr_to_write
3886 nr_to_write_done
= wbc
->nr_to_write
<= 0;
3888 pagevec_release(&pvec
);
3891 if (!scanned
&& !done
) {
3893 * We hit the last page and there is more work to be done: wrap
3894 * back to the start of the file
3900 flush_write_bio(&epd
);
3905 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3906 * @mapping: address space structure to write
3907 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3908 * @writepage: function called for each page
3909 * @data: data passed to writepage function
3911 * If a page is already under I/O, write_cache_pages() skips it, even
3912 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3913 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3914 * and msync() need to guarantee that all the data which was dirty at the time
3915 * the call was made get new I/O started against them. If wbc->sync_mode is
3916 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3917 * existing IO to complete.
3919 static int extent_write_cache_pages(struct address_space
*mapping
,
3920 struct writeback_control
*wbc
,
3921 writepage_t writepage
, void *data
,
3922 void (*flush_fn
)(void *))
3924 struct inode
*inode
= mapping
->host
;
3927 int nr_to_write_done
= 0;
3928 struct pagevec pvec
;
3931 pgoff_t end
; /* Inclusive */
3933 int range_whole
= 0;
3938 * We have to hold onto the inode so that ordered extents can do their
3939 * work when the IO finishes. The alternative to this is failing to add
3940 * an ordered extent if the igrab() fails there and that is a huge pain
3941 * to deal with, so instead just hold onto the inode throughout the
3942 * writepages operation. If it fails here we are freeing up the inode
3943 * anyway and we'd rather not waste our time writing out stuff that is
3944 * going to be truncated anyway.
3949 pagevec_init(&pvec
, 0);
3950 if (wbc
->range_cyclic
) {
3951 index
= mapping
->writeback_index
; /* Start from prev offset */
3954 index
= wbc
->range_start
>> PAGE_SHIFT
;
3955 end
= wbc
->range_end
>> PAGE_SHIFT
;
3956 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
3960 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3961 tag
= PAGECACHE_TAG_TOWRITE
;
3963 tag
= PAGECACHE_TAG_DIRTY
;
3965 if (wbc
->sync_mode
== WB_SYNC_ALL
)
3966 tag_pages_for_writeback(mapping
, index
, end
);
3968 while (!done
&& !nr_to_write_done
&& (index
<= end
) &&
3969 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
3970 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1))) {
3974 for (i
= 0; i
< nr_pages
; i
++) {
3975 struct page
*page
= pvec
.pages
[i
];
3977 done_index
= page
->index
;
3979 * At this point we hold neither mapping->tree_lock nor
3980 * lock on the page itself: the page may be truncated or
3981 * invalidated (changing page->mapping to NULL), or even
3982 * swizzled back from swapper_space to tmpfs file
3985 if (!trylock_page(page
)) {
3990 if (unlikely(page
->mapping
!= mapping
)) {
3995 if (!wbc
->range_cyclic
&& page
->index
> end
) {
4001 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
4002 if (PageWriteback(page
))
4004 wait_on_page_writeback(page
);
4007 if (PageWriteback(page
) ||
4008 !clear_page_dirty_for_io(page
)) {
4013 ret
= (*writepage
)(page
, wbc
, data
);
4015 if (unlikely(ret
== AOP_WRITEPAGE_ACTIVATE
)) {
4021 * done_index is set past this page,
4022 * so media errors will not choke
4023 * background writeout for the entire
4024 * file. This has consequences for
4025 * range_cyclic semantics (ie. it may
4026 * not be suitable for data integrity
4029 done_index
= page
->index
+ 1;
4035 * the filesystem may choose to bump up nr_to_write.
4036 * We have to make sure to honor the new nr_to_write
4039 nr_to_write_done
= wbc
->nr_to_write
<= 0;
4041 pagevec_release(&pvec
);
4044 if (!scanned
&& !done
) {
4046 * We hit the last page and there is more work to be done: wrap
4047 * back to the start of the file
4054 if (wbc
->range_cyclic
|| (wbc
->nr_to_write
> 0 && range_whole
))
4055 mapping
->writeback_index
= done_index
;
4057 btrfs_add_delayed_iput(inode
);
4061 static void flush_epd_write_bio(struct extent_page_data
*epd
)
4066 ret
= submit_one_bio(epd
->bio
, 0, epd
->bio_flags
);
4067 BUG_ON(ret
< 0); /* -ENOMEM */
4072 static noinline
void flush_write_bio(void *data
)
4074 struct extent_page_data
*epd
= data
;
4075 flush_epd_write_bio(epd
);
4078 int extent_write_full_page(struct extent_io_tree
*tree
, struct page
*page
,
4079 get_extent_t
*get_extent
,
4080 struct writeback_control
*wbc
)
4083 struct extent_page_data epd
= {
4086 .get_extent
= get_extent
,
4088 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
4092 ret
= __extent_writepage(page
, wbc
, &epd
);
4094 flush_epd_write_bio(&epd
);
4098 int extent_write_locked_range(struct extent_io_tree
*tree
, struct inode
*inode
,
4099 u64 start
, u64 end
, get_extent_t
*get_extent
,
4103 struct address_space
*mapping
= inode
->i_mapping
;
4105 unsigned long nr_pages
= (end
- start
+ PAGE_SIZE
) >>
4108 struct extent_page_data epd
= {
4111 .get_extent
= get_extent
,
4113 .sync_io
= mode
== WB_SYNC_ALL
,
4116 struct writeback_control wbc_writepages
= {
4118 .nr_to_write
= nr_pages
* 2,
4119 .range_start
= start
,
4120 .range_end
= end
+ 1,
4123 while (start
<= end
) {
4124 page
= find_get_page(mapping
, start
>> PAGE_SHIFT
);
4125 if (clear_page_dirty_for_io(page
))
4126 ret
= __extent_writepage(page
, &wbc_writepages
, &epd
);
4128 if (tree
->ops
&& tree
->ops
->writepage_end_io_hook
)
4129 tree
->ops
->writepage_end_io_hook(page
, start
,
4130 start
+ PAGE_SIZE
- 1,
4138 flush_epd_write_bio(&epd
);
4142 int extent_writepages(struct extent_io_tree
*tree
,
4143 struct address_space
*mapping
,
4144 get_extent_t
*get_extent
,
4145 struct writeback_control
*wbc
)
4148 struct extent_page_data epd
= {
4151 .get_extent
= get_extent
,
4153 .sync_io
= wbc
->sync_mode
== WB_SYNC_ALL
,
4157 ret
= extent_write_cache_pages(mapping
, wbc
, __extent_writepage
, &epd
,
4159 flush_epd_write_bio(&epd
);
4163 int extent_readpages(struct extent_io_tree
*tree
,
4164 struct address_space
*mapping
,
4165 struct list_head
*pages
, unsigned nr_pages
,
4166 get_extent_t get_extent
)
4168 struct bio
*bio
= NULL
;
4170 unsigned long bio_flags
= 0;
4171 struct page
*pagepool
[16];
4173 struct extent_map
*em_cached
= NULL
;
4175 u64 prev_em_start
= (u64
)-1;
4177 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
4178 page
= list_entry(pages
->prev
, struct page
, lru
);
4180 prefetchw(&page
->flags
);
4181 list_del(&page
->lru
);
4182 if (add_to_page_cache_lru(page
, mapping
,
4184 readahead_gfp_mask(mapping
))) {
4189 pagepool
[nr
++] = page
;
4190 if (nr
< ARRAY_SIZE(pagepool
))
4192 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
4193 &bio
, 0, &bio_flags
, &prev_em_start
);
4197 __extent_readpages(tree
, pagepool
, nr
, get_extent
, &em_cached
,
4198 &bio
, 0, &bio_flags
, &prev_em_start
);
4201 free_extent_map(em_cached
);
4203 BUG_ON(!list_empty(pages
));
4205 return submit_one_bio(bio
, 0, bio_flags
);
4210 * basic invalidatepage code, this waits on any locked or writeback
4211 * ranges corresponding to the page, and then deletes any extent state
4212 * records from the tree
4214 int extent_invalidatepage(struct extent_io_tree
*tree
,
4215 struct page
*page
, unsigned long offset
)
4217 struct extent_state
*cached_state
= NULL
;
4218 u64 start
= page_offset(page
);
4219 u64 end
= start
+ PAGE_SIZE
- 1;
4220 size_t blocksize
= page
->mapping
->host
->i_sb
->s_blocksize
;
4222 start
+= ALIGN(offset
, blocksize
);
4226 lock_extent_bits(tree
, start
, end
, &cached_state
);
4227 wait_on_page_writeback(page
);
4228 clear_extent_bit(tree
, start
, end
,
4229 EXTENT_LOCKED
| EXTENT_DIRTY
| EXTENT_DELALLOC
|
4230 EXTENT_DO_ACCOUNTING
,
4231 1, 1, &cached_state
, GFP_NOFS
);
4236 * a helper for releasepage, this tests for areas of the page that
4237 * are locked or under IO and drops the related state bits if it is safe
4240 static int try_release_extent_state(struct extent_map_tree
*map
,
4241 struct extent_io_tree
*tree
,
4242 struct page
*page
, gfp_t mask
)
4244 u64 start
= page_offset(page
);
4245 u64 end
= start
+ PAGE_SIZE
- 1;
4248 if (test_range_bit(tree
, start
, end
,
4249 EXTENT_IOBITS
, 0, NULL
))
4253 * at this point we can safely clear everything except the
4254 * locked bit and the nodatasum bit
4256 ret
= clear_extent_bit(tree
, start
, end
,
4257 ~(EXTENT_LOCKED
| EXTENT_NODATASUM
),
4260 /* if clear_extent_bit failed for enomem reasons,
4261 * we can't allow the release to continue.
4272 * a helper for releasepage. As long as there are no locked extents
4273 * in the range corresponding to the page, both state records and extent
4274 * map records are removed
4276 int try_release_extent_mapping(struct extent_map_tree
*map
,
4277 struct extent_io_tree
*tree
, struct page
*page
,
4280 struct extent_map
*em
;
4281 u64 start
= page_offset(page
);
4282 u64 end
= start
+ PAGE_SIZE
- 1;
4284 if (gfpflags_allow_blocking(mask
) &&
4285 page
->mapping
->host
->i_size
> SZ_16M
) {
4287 while (start
<= end
) {
4288 len
= end
- start
+ 1;
4289 write_lock(&map
->lock
);
4290 em
= lookup_extent_mapping(map
, start
, len
);
4292 write_unlock(&map
->lock
);
4295 if (test_bit(EXTENT_FLAG_PINNED
, &em
->flags
) ||
4296 em
->start
!= start
) {
4297 write_unlock(&map
->lock
);
4298 free_extent_map(em
);
4301 if (!test_range_bit(tree
, em
->start
,
4302 extent_map_end(em
) - 1,
4303 EXTENT_LOCKED
| EXTENT_WRITEBACK
,
4305 remove_extent_mapping(map
, em
);
4306 /* once for the rb tree */
4307 free_extent_map(em
);
4309 start
= extent_map_end(em
);
4310 write_unlock(&map
->lock
);
4313 free_extent_map(em
);
4316 return try_release_extent_state(map
, tree
, page
, mask
);
4320 * helper function for fiemap, which doesn't want to see any holes.
4321 * This maps until we find something past 'last'
4323 static struct extent_map
*get_extent_skip_holes(struct inode
*inode
,
4326 get_extent_t
*get_extent
)
4328 u64 sectorsize
= btrfs_inode_sectorsize(inode
);
4329 struct extent_map
*em
;
4336 len
= last
- offset
;
4339 len
= ALIGN(len
, sectorsize
);
4340 em
= get_extent(BTRFS_I(inode
), NULL
, 0, offset
, len
, 0);
4341 if (IS_ERR_OR_NULL(em
))
4344 /* if this isn't a hole return it */
4345 if (!test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
) &&
4346 em
->block_start
!= EXTENT_MAP_HOLE
) {
4350 /* this is a hole, advance to the next extent */
4351 offset
= extent_map_end(em
);
4352 free_extent_map(em
);
4360 * To cache previous fiemap extent
4362 * Will be used for merging fiemap extent
4364 struct fiemap_cache
{
4373 * Helper to submit fiemap extent.
4375 * Will try to merge current fiemap extent specified by @offset, @phys,
4376 * @len and @flags with cached one.
4377 * And only when we fails to merge, cached one will be submitted as
4380 * Return value is the same as fiemap_fill_next_extent().
4382 static int emit_fiemap_extent(struct fiemap_extent_info
*fieinfo
,
4383 struct fiemap_cache
*cache
,
4384 u64 offset
, u64 phys
, u64 len
, u32 flags
)
4392 * Sanity check, extent_fiemap() should have ensured that new
4393 * fiemap extent won't overlap with cahced one.
4396 * NOTE: Physical address can overlap, due to compression
4398 if (cache
->offset
+ cache
->len
> offset
) {
4404 * Only merges fiemap extents if
4405 * 1) Their logical addresses are continuous
4407 * 2) Their physical addresses are continuous
4408 * So truly compressed (physical size smaller than logical size)
4409 * extents won't get merged with each other
4411 * 3) Share same flags except FIEMAP_EXTENT_LAST
4412 * So regular extent won't get merged with prealloc extent
4414 if (cache
->offset
+ cache
->len
== offset
&&
4415 cache
->phys
+ cache
->len
== phys
&&
4416 (cache
->flags
& ~FIEMAP_EXTENT_LAST
) ==
4417 (flags
& ~FIEMAP_EXTENT_LAST
)) {
4419 cache
->flags
|= flags
;
4420 goto try_submit_last
;
4423 /* Not mergeable, need to submit cached one */
4424 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
, cache
->phys
,
4425 cache
->len
, cache
->flags
);
4426 cache
->cached
= false;
4430 cache
->cached
= true;
4431 cache
->offset
= offset
;
4434 cache
->flags
= flags
;
4436 if (cache
->flags
& FIEMAP_EXTENT_LAST
) {
4437 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
,
4438 cache
->phys
, cache
->len
, cache
->flags
);
4439 cache
->cached
= false;
4445 * Emit last fiemap cache
4447 * The last fiemap cache may still be cached in the following case:
4449 * |<- Fiemap range ->|
4450 * |<------------ First extent ----------->|
4452 * In this case, the first extent range will be cached but not emitted.
4453 * So we must emit it before ending extent_fiemap().
4455 static int emit_last_fiemap_cache(struct btrfs_fs_info
*fs_info
,
4456 struct fiemap_extent_info
*fieinfo
,
4457 struct fiemap_cache
*cache
)
4464 ret
= fiemap_fill_next_extent(fieinfo
, cache
->offset
, cache
->phys
,
4465 cache
->len
, cache
->flags
);
4466 cache
->cached
= false;
4472 int extent_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4473 __u64 start
, __u64 len
, get_extent_t
*get_extent
)
4477 u64 max
= start
+ len
;
4481 u64 last_for_get_extent
= 0;
4483 u64 isize
= i_size_read(inode
);
4484 struct btrfs_key found_key
;
4485 struct extent_map
*em
= NULL
;
4486 struct extent_state
*cached_state
= NULL
;
4487 struct btrfs_path
*path
;
4488 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4489 struct fiemap_cache cache
= { 0 };
4498 path
= btrfs_alloc_path();
4501 path
->leave_spinning
= 1;
4503 start
= round_down(start
, btrfs_inode_sectorsize(inode
));
4504 len
= round_up(max
, btrfs_inode_sectorsize(inode
)) - start
;
4507 * lookup the last file extent. We're not using i_size here
4508 * because there might be preallocation past i_size
4510 ret
= btrfs_lookup_file_extent(NULL
, root
, path
,
4511 btrfs_ino(BTRFS_I(inode
)), -1, 0);
4513 btrfs_free_path(path
);
4522 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, path
->slots
[0]);
4523 found_type
= found_key
.type
;
4525 /* No extents, but there might be delalloc bits */
4526 if (found_key
.objectid
!= btrfs_ino(BTRFS_I(inode
)) ||
4527 found_type
!= BTRFS_EXTENT_DATA_KEY
) {
4528 /* have to trust i_size as the end */
4530 last_for_get_extent
= isize
;
4533 * remember the start of the last extent. There are a
4534 * bunch of different factors that go into the length of the
4535 * extent, so its much less complex to remember where it started
4537 last
= found_key
.offset
;
4538 last_for_get_extent
= last
+ 1;
4540 btrfs_release_path(path
);
4543 * we might have some extents allocated but more delalloc past those
4544 * extents. so, we trust isize unless the start of the last extent is
4549 last_for_get_extent
= isize
;
4552 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4555 em
= get_extent_skip_holes(inode
, start
, last_for_get_extent
,
4565 u64 offset_in_extent
= 0;
4567 /* break if the extent we found is outside the range */
4568 if (em
->start
>= max
|| extent_map_end(em
) < off
)
4572 * get_extent may return an extent that starts before our
4573 * requested range. We have to make sure the ranges
4574 * we return to fiemap always move forward and don't
4575 * overlap, so adjust the offsets here
4577 em_start
= max(em
->start
, off
);
4580 * record the offset from the start of the extent
4581 * for adjusting the disk offset below. Only do this if the
4582 * extent isn't compressed since our in ram offset may be past
4583 * what we have actually allocated on disk.
4585 if (!test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4586 offset_in_extent
= em_start
- em
->start
;
4587 em_end
= extent_map_end(em
);
4588 em_len
= em_end
- em_start
;
4593 * bump off for our next call to get_extent
4595 off
= extent_map_end(em
);
4599 if (em
->block_start
== EXTENT_MAP_LAST_BYTE
) {
4601 flags
|= FIEMAP_EXTENT_LAST
;
4602 } else if (em
->block_start
== EXTENT_MAP_INLINE
) {
4603 flags
|= (FIEMAP_EXTENT_DATA_INLINE
|
4604 FIEMAP_EXTENT_NOT_ALIGNED
);
4605 } else if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
4606 flags
|= (FIEMAP_EXTENT_DELALLOC
|
4607 FIEMAP_EXTENT_UNKNOWN
);
4608 } else if (fieinfo
->fi_extents_max
) {
4609 u64 bytenr
= em
->block_start
-
4610 (em
->start
- em
->orig_start
);
4612 disko
= em
->block_start
+ offset_in_extent
;
4615 * As btrfs supports shared space, this information
4616 * can be exported to userspace tools via
4617 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4618 * then we're just getting a count and we can skip the
4621 ret
= btrfs_check_shared(root
,
4622 btrfs_ino(BTRFS_I(inode
)),
4627 flags
|= FIEMAP_EXTENT_SHARED
;
4630 if (test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
))
4631 flags
|= FIEMAP_EXTENT_ENCODED
;
4632 if (test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))
4633 flags
|= FIEMAP_EXTENT_UNWRITTEN
;
4635 free_extent_map(em
);
4637 if ((em_start
>= last
) || em_len
== (u64
)-1 ||
4638 (last
== (u64
)-1 && isize
<= em_end
)) {
4639 flags
|= FIEMAP_EXTENT_LAST
;
4643 /* now scan forward to see if this is really the last extent. */
4644 em
= get_extent_skip_holes(inode
, off
, last_for_get_extent
,
4651 flags
|= FIEMAP_EXTENT_LAST
;
4654 ret
= emit_fiemap_extent(fieinfo
, &cache
, em_start
, disko
,
4664 ret
= emit_last_fiemap_cache(root
->fs_info
, fieinfo
, &cache
);
4665 free_extent_map(em
);
4667 btrfs_free_path(path
);
4668 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, start
, start
+ len
- 1,
4669 &cached_state
, GFP_NOFS
);
4673 static void __free_extent_buffer(struct extent_buffer
*eb
)
4675 btrfs_leak_debug_del(&eb
->leak_list
);
4676 kmem_cache_free(extent_buffer_cache
, eb
);
4679 int extent_buffer_under_io(struct extent_buffer
*eb
)
4681 return (atomic_read(&eb
->io_pages
) ||
4682 test_bit(EXTENT_BUFFER_WRITEBACK
, &eb
->bflags
) ||
4683 test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4687 * Helper for releasing extent buffer page.
4689 static void btrfs_release_extent_buffer_page(struct extent_buffer
*eb
)
4691 unsigned long index
;
4693 int mapped
= !test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4695 BUG_ON(extent_buffer_under_io(eb
));
4697 index
= num_extent_pages(eb
->start
, eb
->len
);
4703 page
= eb
->pages
[index
];
4707 spin_lock(&page
->mapping
->private_lock
);
4709 * We do this since we'll remove the pages after we've
4710 * removed the eb from the radix tree, so we could race
4711 * and have this page now attached to the new eb. So
4712 * only clear page_private if it's still connected to
4715 if (PagePrivate(page
) &&
4716 page
->private == (unsigned long)eb
) {
4717 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
));
4718 BUG_ON(PageDirty(page
));
4719 BUG_ON(PageWriteback(page
));
4721 * We need to make sure we haven't be attached
4724 ClearPagePrivate(page
);
4725 set_page_private(page
, 0);
4726 /* One for the page private */
4731 spin_unlock(&page
->mapping
->private_lock
);
4733 /* One for when we allocated the page */
4735 } while (index
!= 0);
4739 * Helper for releasing the extent buffer.
4741 static inline void btrfs_release_extent_buffer(struct extent_buffer
*eb
)
4743 btrfs_release_extent_buffer_page(eb
);
4744 __free_extent_buffer(eb
);
4747 static struct extent_buffer
*
4748 __alloc_extent_buffer(struct btrfs_fs_info
*fs_info
, u64 start
,
4751 struct extent_buffer
*eb
= NULL
;
4753 eb
= kmem_cache_zalloc(extent_buffer_cache
, GFP_NOFS
|__GFP_NOFAIL
);
4756 eb
->fs_info
= fs_info
;
4758 rwlock_init(&eb
->lock
);
4759 atomic_set(&eb
->write_locks
, 0);
4760 atomic_set(&eb
->read_locks
, 0);
4761 atomic_set(&eb
->blocking_readers
, 0);
4762 atomic_set(&eb
->blocking_writers
, 0);
4763 atomic_set(&eb
->spinning_readers
, 0);
4764 atomic_set(&eb
->spinning_writers
, 0);
4765 eb
->lock_nested
= 0;
4766 init_waitqueue_head(&eb
->write_lock_wq
);
4767 init_waitqueue_head(&eb
->read_lock_wq
);
4769 btrfs_leak_debug_add(&eb
->leak_list
, &buffers
);
4771 spin_lock_init(&eb
->refs_lock
);
4772 atomic_set(&eb
->refs
, 1);
4773 atomic_set(&eb
->io_pages
, 0);
4776 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4778 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4779 > MAX_INLINE_EXTENT_BUFFER_SIZE
);
4780 BUG_ON(len
> MAX_INLINE_EXTENT_BUFFER_SIZE
);
4785 struct extent_buffer
*btrfs_clone_extent_buffer(struct extent_buffer
*src
)
4789 struct extent_buffer
*new;
4790 unsigned long num_pages
= num_extent_pages(src
->start
, src
->len
);
4792 new = __alloc_extent_buffer(src
->fs_info
, src
->start
, src
->len
);
4796 for (i
= 0; i
< num_pages
; i
++) {
4797 p
= alloc_page(GFP_NOFS
);
4799 btrfs_release_extent_buffer(new);
4802 attach_extent_buffer_page(new, p
);
4803 WARN_ON(PageDirty(p
));
4806 copy_page(page_address(p
), page_address(src
->pages
[i
]));
4809 set_bit(EXTENT_BUFFER_UPTODATE
, &new->bflags
);
4810 set_bit(EXTENT_BUFFER_DUMMY
, &new->bflags
);
4815 struct extent_buffer
*__alloc_dummy_extent_buffer(struct btrfs_fs_info
*fs_info
,
4816 u64 start
, unsigned long len
)
4818 struct extent_buffer
*eb
;
4819 unsigned long num_pages
;
4822 num_pages
= num_extent_pages(start
, len
);
4824 eb
= __alloc_extent_buffer(fs_info
, start
, len
);
4828 for (i
= 0; i
< num_pages
; i
++) {
4829 eb
->pages
[i
] = alloc_page(GFP_NOFS
);
4833 set_extent_buffer_uptodate(eb
);
4834 btrfs_set_header_nritems(eb
, 0);
4835 set_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
);
4840 __free_page(eb
->pages
[i
- 1]);
4841 __free_extent_buffer(eb
);
4845 struct extent_buffer
*alloc_dummy_extent_buffer(struct btrfs_fs_info
*fs_info
,
4848 return __alloc_dummy_extent_buffer(fs_info
, start
, fs_info
->nodesize
);
4851 static void check_buffer_tree_ref(struct extent_buffer
*eb
)
4854 /* the ref bit is tricky. We have to make sure it is set
4855 * if we have the buffer dirty. Otherwise the
4856 * code to free a buffer can end up dropping a dirty
4859 * Once the ref bit is set, it won't go away while the
4860 * buffer is dirty or in writeback, and it also won't
4861 * go away while we have the reference count on the
4864 * We can't just set the ref bit without bumping the
4865 * ref on the eb because free_extent_buffer might
4866 * see the ref bit and try to clear it. If this happens
4867 * free_extent_buffer might end up dropping our original
4868 * ref by mistake and freeing the page before we are able
4869 * to add one more ref.
4871 * So bump the ref count first, then set the bit. If someone
4872 * beat us to it, drop the ref we added.
4874 refs
= atomic_read(&eb
->refs
);
4875 if (refs
>= 2 && test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4878 spin_lock(&eb
->refs_lock
);
4879 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
4880 atomic_inc(&eb
->refs
);
4881 spin_unlock(&eb
->refs_lock
);
4884 static void mark_extent_buffer_accessed(struct extent_buffer
*eb
,
4885 struct page
*accessed
)
4887 unsigned long num_pages
, i
;
4889 check_buffer_tree_ref(eb
);
4891 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
4892 for (i
= 0; i
< num_pages
; i
++) {
4893 struct page
*p
= eb
->pages
[i
];
4896 mark_page_accessed(p
);
4900 struct extent_buffer
*find_extent_buffer(struct btrfs_fs_info
*fs_info
,
4903 struct extent_buffer
*eb
;
4906 eb
= radix_tree_lookup(&fs_info
->buffer_radix
,
4907 start
>> PAGE_SHIFT
);
4908 if (eb
&& atomic_inc_not_zero(&eb
->refs
)) {
4911 * Lock our eb's refs_lock to avoid races with
4912 * free_extent_buffer. When we get our eb it might be flagged
4913 * with EXTENT_BUFFER_STALE and another task running
4914 * free_extent_buffer might have seen that flag set,
4915 * eb->refs == 2, that the buffer isn't under IO (dirty and
4916 * writeback flags not set) and it's still in the tree (flag
4917 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4918 * of decrementing the extent buffer's reference count twice.
4919 * So here we could race and increment the eb's reference count,
4920 * clear its stale flag, mark it as dirty and drop our reference
4921 * before the other task finishes executing free_extent_buffer,
4922 * which would later result in an attempt to free an extent
4923 * buffer that is dirty.
4925 if (test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
)) {
4926 spin_lock(&eb
->refs_lock
);
4927 spin_unlock(&eb
->refs_lock
);
4929 mark_extent_buffer_accessed(eb
, NULL
);
4937 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4938 struct extent_buffer
*alloc_test_extent_buffer(struct btrfs_fs_info
*fs_info
,
4941 struct extent_buffer
*eb
, *exists
= NULL
;
4944 eb
= find_extent_buffer(fs_info
, start
);
4947 eb
= alloc_dummy_extent_buffer(fs_info
, start
);
4950 eb
->fs_info
= fs_info
;
4952 ret
= radix_tree_preload(GFP_NOFS
);
4955 spin_lock(&fs_info
->buffer_lock
);
4956 ret
= radix_tree_insert(&fs_info
->buffer_radix
,
4957 start
>> PAGE_SHIFT
, eb
);
4958 spin_unlock(&fs_info
->buffer_lock
);
4959 radix_tree_preload_end();
4960 if (ret
== -EEXIST
) {
4961 exists
= find_extent_buffer(fs_info
, start
);
4967 check_buffer_tree_ref(eb
);
4968 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
4971 * We will free dummy extent buffer's if they come into
4972 * free_extent_buffer with a ref count of 2, but if we are using this we
4973 * want the buffers to stay in memory until we're done with them, so
4974 * bump the ref count again.
4976 atomic_inc(&eb
->refs
);
4979 btrfs_release_extent_buffer(eb
);
4984 struct extent_buffer
*alloc_extent_buffer(struct btrfs_fs_info
*fs_info
,
4987 unsigned long len
= fs_info
->nodesize
;
4988 unsigned long num_pages
= num_extent_pages(start
, len
);
4990 unsigned long index
= start
>> PAGE_SHIFT
;
4991 struct extent_buffer
*eb
;
4992 struct extent_buffer
*exists
= NULL
;
4994 struct address_space
*mapping
= fs_info
->btree_inode
->i_mapping
;
4998 if (!IS_ALIGNED(start
, fs_info
->sectorsize
)) {
4999 btrfs_err(fs_info
, "bad tree block start %llu", start
);
5000 return ERR_PTR(-EINVAL
);
5003 eb
= find_extent_buffer(fs_info
, start
);
5007 eb
= __alloc_extent_buffer(fs_info
, start
, len
);
5009 return ERR_PTR(-ENOMEM
);
5011 for (i
= 0; i
< num_pages
; i
++, index
++) {
5012 p
= find_or_create_page(mapping
, index
, GFP_NOFS
|__GFP_NOFAIL
);
5014 exists
= ERR_PTR(-ENOMEM
);
5018 spin_lock(&mapping
->private_lock
);
5019 if (PagePrivate(p
)) {
5021 * We could have already allocated an eb for this page
5022 * and attached one so lets see if we can get a ref on
5023 * the existing eb, and if we can we know it's good and
5024 * we can just return that one, else we know we can just
5025 * overwrite page->private.
5027 exists
= (struct extent_buffer
*)p
->private;
5028 if (atomic_inc_not_zero(&exists
->refs
)) {
5029 spin_unlock(&mapping
->private_lock
);
5032 mark_extent_buffer_accessed(exists
, p
);
5038 * Do this so attach doesn't complain and we need to
5039 * drop the ref the old guy had.
5041 ClearPagePrivate(p
);
5042 WARN_ON(PageDirty(p
));
5045 attach_extent_buffer_page(eb
, p
);
5046 spin_unlock(&mapping
->private_lock
);
5047 WARN_ON(PageDirty(p
));
5049 if (!PageUptodate(p
))
5053 * see below about how we avoid a nasty race with release page
5054 * and why we unlock later
5058 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5060 ret
= radix_tree_preload(GFP_NOFS
);
5062 exists
= ERR_PTR(ret
);
5066 spin_lock(&fs_info
->buffer_lock
);
5067 ret
= radix_tree_insert(&fs_info
->buffer_radix
,
5068 start
>> PAGE_SHIFT
, eb
);
5069 spin_unlock(&fs_info
->buffer_lock
);
5070 radix_tree_preload_end();
5071 if (ret
== -EEXIST
) {
5072 exists
= find_extent_buffer(fs_info
, start
);
5078 /* add one reference for the tree */
5079 check_buffer_tree_ref(eb
);
5080 set_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
);
5083 * there is a race where release page may have
5084 * tried to find this extent buffer in the radix
5085 * but failed. It will tell the VM it is safe to
5086 * reclaim the, and it will clear the page private bit.
5087 * We must make sure to set the page private bit properly
5088 * after the extent buffer is in the radix tree so
5089 * it doesn't get lost
5091 SetPageChecked(eb
->pages
[0]);
5092 for (i
= 1; i
< num_pages
; i
++) {
5094 ClearPageChecked(p
);
5097 unlock_page(eb
->pages
[0]);
5101 WARN_ON(!atomic_dec_and_test(&eb
->refs
));
5102 for (i
= 0; i
< num_pages
; i
++) {
5104 unlock_page(eb
->pages
[i
]);
5107 btrfs_release_extent_buffer(eb
);
5111 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head
*head
)
5113 struct extent_buffer
*eb
=
5114 container_of(head
, struct extent_buffer
, rcu_head
);
5116 __free_extent_buffer(eb
);
5119 /* Expects to have eb->eb_lock already held */
5120 static int release_extent_buffer(struct extent_buffer
*eb
)
5122 WARN_ON(atomic_read(&eb
->refs
) == 0);
5123 if (atomic_dec_and_test(&eb
->refs
)) {
5124 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE
, &eb
->bflags
)) {
5125 struct btrfs_fs_info
*fs_info
= eb
->fs_info
;
5127 spin_unlock(&eb
->refs_lock
);
5129 spin_lock(&fs_info
->buffer_lock
);
5130 radix_tree_delete(&fs_info
->buffer_radix
,
5131 eb
->start
>> PAGE_SHIFT
);
5132 spin_unlock(&fs_info
->buffer_lock
);
5134 spin_unlock(&eb
->refs_lock
);
5137 /* Should be safe to release our pages at this point */
5138 btrfs_release_extent_buffer_page(eb
);
5139 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5140 if (unlikely(test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))) {
5141 __free_extent_buffer(eb
);
5145 call_rcu(&eb
->rcu_head
, btrfs_release_extent_buffer_rcu
);
5148 spin_unlock(&eb
->refs_lock
);
5153 void free_extent_buffer(struct extent_buffer
*eb
)
5161 refs
= atomic_read(&eb
->refs
);
5164 old
= atomic_cmpxchg(&eb
->refs
, refs
, refs
- 1);
5169 spin_lock(&eb
->refs_lock
);
5170 if (atomic_read(&eb
->refs
) == 2 &&
5171 test_bit(EXTENT_BUFFER_DUMMY
, &eb
->bflags
))
5172 atomic_dec(&eb
->refs
);
5174 if (atomic_read(&eb
->refs
) == 2 &&
5175 test_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
) &&
5176 !extent_buffer_under_io(eb
) &&
5177 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
5178 atomic_dec(&eb
->refs
);
5181 * I know this is terrible, but it's temporary until we stop tracking
5182 * the uptodate bits and such for the extent buffers.
5184 release_extent_buffer(eb
);
5187 void free_extent_buffer_stale(struct extent_buffer
*eb
)
5192 spin_lock(&eb
->refs_lock
);
5193 set_bit(EXTENT_BUFFER_STALE
, &eb
->bflags
);
5195 if (atomic_read(&eb
->refs
) == 2 && !extent_buffer_under_io(eb
) &&
5196 test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
))
5197 atomic_dec(&eb
->refs
);
5198 release_extent_buffer(eb
);
5201 void clear_extent_buffer_dirty(struct extent_buffer
*eb
)
5204 unsigned long num_pages
;
5207 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5209 for (i
= 0; i
< num_pages
; i
++) {
5210 page
= eb
->pages
[i
];
5211 if (!PageDirty(page
))
5215 WARN_ON(!PagePrivate(page
));
5217 clear_page_dirty_for_io(page
);
5218 spin_lock_irq(&page
->mapping
->tree_lock
);
5219 if (!PageDirty(page
)) {
5220 radix_tree_tag_clear(&page
->mapping
->page_tree
,
5222 PAGECACHE_TAG_DIRTY
);
5224 spin_unlock_irq(&page
->mapping
->tree_lock
);
5225 ClearPageError(page
);
5228 WARN_ON(atomic_read(&eb
->refs
) == 0);
5231 int set_extent_buffer_dirty(struct extent_buffer
*eb
)
5234 unsigned long num_pages
;
5237 check_buffer_tree_ref(eb
);
5239 was_dirty
= test_and_set_bit(EXTENT_BUFFER_DIRTY
, &eb
->bflags
);
5241 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5242 WARN_ON(atomic_read(&eb
->refs
) == 0);
5243 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
));
5245 for (i
= 0; i
< num_pages
; i
++)
5246 set_page_dirty(eb
->pages
[i
]);
5250 void clear_extent_buffer_uptodate(struct extent_buffer
*eb
)
5254 unsigned long num_pages
;
5256 clear_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5257 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5258 for (i
= 0; i
< num_pages
; i
++) {
5259 page
= eb
->pages
[i
];
5261 ClearPageUptodate(page
);
5265 void set_extent_buffer_uptodate(struct extent_buffer
*eb
)
5269 unsigned long num_pages
;
5271 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5272 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5273 for (i
= 0; i
< num_pages
; i
++) {
5274 page
= eb
->pages
[i
];
5275 SetPageUptodate(page
);
5279 int extent_buffer_uptodate(struct extent_buffer
*eb
)
5281 return test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5284 int read_extent_buffer_pages(struct extent_io_tree
*tree
,
5285 struct extent_buffer
*eb
, int wait
,
5286 get_extent_t
*get_extent
, int mirror_num
)
5292 int locked_pages
= 0;
5293 int all_uptodate
= 1;
5294 unsigned long num_pages
;
5295 unsigned long num_reads
= 0;
5296 struct bio
*bio
= NULL
;
5297 unsigned long bio_flags
= 0;
5299 if (test_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
))
5302 num_pages
= num_extent_pages(eb
->start
, eb
->len
);
5303 for (i
= 0; i
< num_pages
; i
++) {
5304 page
= eb
->pages
[i
];
5305 if (wait
== WAIT_NONE
) {
5306 if (!trylock_page(page
))
5314 * We need to firstly lock all pages to make sure that
5315 * the uptodate bit of our pages won't be affected by
5316 * clear_extent_buffer_uptodate().
5318 for (i
= 0; i
< num_pages
; i
++) {
5319 page
= eb
->pages
[i
];
5320 if (!PageUptodate(page
)) {
5327 set_bit(EXTENT_BUFFER_UPTODATE
, &eb
->bflags
);
5331 clear_bit(EXTENT_BUFFER_READ_ERR
, &eb
->bflags
);
5332 eb
->read_mirror
= 0;
5333 atomic_set(&eb
->io_pages
, num_reads
);
5334 for (i
= 0; i
< num_pages
; i
++) {
5335 page
= eb
->pages
[i
];
5337 if (!PageUptodate(page
)) {
5339 atomic_dec(&eb
->io_pages
);
5344 ClearPageError(page
);
5345 err
= __extent_read_full_page(tree
, page
,
5347 mirror_num
, &bio_flags
,
5352 * We use &bio in above __extent_read_full_page,
5353 * so we ensure that if it returns error, the
5354 * current page fails to add itself to bio and
5355 * it's been unlocked.
5357 * We must dec io_pages by ourselves.
5359 atomic_dec(&eb
->io_pages
);
5367 err
= submit_one_bio(bio
, mirror_num
, bio_flags
);
5372 if (ret
|| wait
!= WAIT_COMPLETE
)
5375 for (i
= 0; i
< num_pages
; i
++) {
5376 page
= eb
->pages
[i
];
5377 wait_on_page_locked(page
);
5378 if (!PageUptodate(page
))
5385 while (locked_pages
> 0) {
5387 page
= eb
->pages
[locked_pages
];
5393 void read_extent_buffer(const struct extent_buffer
*eb
, void *dstv
,
5394 unsigned long start
, unsigned long len
)
5400 char *dst
= (char *)dstv
;
5401 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5402 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5404 if (start
+ len
> eb
->len
) {
5405 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5406 eb
->start
, eb
->len
, start
, len
);
5407 memset(dst
, 0, len
);
5411 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5414 page
= eb
->pages
[i
];
5416 cur
= min(len
, (PAGE_SIZE
- offset
));
5417 kaddr
= page_address(page
);
5418 memcpy(dst
, kaddr
+ offset
, cur
);
5427 int read_extent_buffer_to_user(const struct extent_buffer
*eb
,
5429 unsigned long start
, unsigned long len
)
5435 char __user
*dst
= (char __user
*)dstv
;
5436 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5437 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5440 WARN_ON(start
> eb
->len
);
5441 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5443 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5446 page
= eb
->pages
[i
];
5448 cur
= min(len
, (PAGE_SIZE
- offset
));
5449 kaddr
= page_address(page
);
5450 if (copy_to_user(dst
, kaddr
+ offset
, cur
)) {
5465 * return 0 if the item is found within a page.
5466 * return 1 if the item spans two pages.
5467 * return -EINVAL otherwise.
5469 int map_private_extent_buffer(const struct extent_buffer
*eb
,
5470 unsigned long start
, unsigned long min_len
,
5471 char **map
, unsigned long *map_start
,
5472 unsigned long *map_len
)
5474 size_t offset
= start
& (PAGE_SIZE
- 1);
5477 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5478 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5479 unsigned long end_i
= (start_offset
+ start
+ min_len
- 1) >>
5482 if (start
+ min_len
> eb
->len
) {
5483 WARN(1, KERN_ERR
"btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5484 eb
->start
, eb
->len
, start
, min_len
);
5492 offset
= start_offset
;
5496 *map_start
= ((u64
)i
<< PAGE_SHIFT
) - start_offset
;
5500 kaddr
= page_address(p
);
5501 *map
= kaddr
+ offset
;
5502 *map_len
= PAGE_SIZE
- offset
;
5506 int memcmp_extent_buffer(const struct extent_buffer
*eb
, const void *ptrv
,
5507 unsigned long start
, unsigned long len
)
5513 char *ptr
= (char *)ptrv
;
5514 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5515 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5518 WARN_ON(start
> eb
->len
);
5519 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5521 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5524 page
= eb
->pages
[i
];
5526 cur
= min(len
, (PAGE_SIZE
- offset
));
5528 kaddr
= page_address(page
);
5529 ret
= memcmp(ptr
, kaddr
+ offset
, cur
);
5541 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer
*eb
,
5546 WARN_ON(!PageUptodate(eb
->pages
[0]));
5547 kaddr
= page_address(eb
->pages
[0]);
5548 memcpy(kaddr
+ offsetof(struct btrfs_header
, chunk_tree_uuid
), srcv
,
5552 void write_extent_buffer_fsid(struct extent_buffer
*eb
, const void *srcv
)
5556 WARN_ON(!PageUptodate(eb
->pages
[0]));
5557 kaddr
= page_address(eb
->pages
[0]);
5558 memcpy(kaddr
+ offsetof(struct btrfs_header
, fsid
), srcv
,
5562 void write_extent_buffer(struct extent_buffer
*eb
, const void *srcv
,
5563 unsigned long start
, unsigned long len
)
5569 char *src
= (char *)srcv
;
5570 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5571 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5573 WARN_ON(start
> eb
->len
);
5574 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5576 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5579 page
= eb
->pages
[i
];
5580 WARN_ON(!PageUptodate(page
));
5582 cur
= min(len
, PAGE_SIZE
- offset
);
5583 kaddr
= page_address(page
);
5584 memcpy(kaddr
+ offset
, src
, cur
);
5593 void memzero_extent_buffer(struct extent_buffer
*eb
, unsigned long start
,
5600 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5601 unsigned long i
= (start_offset
+ start
) >> PAGE_SHIFT
;
5603 WARN_ON(start
> eb
->len
);
5604 WARN_ON(start
+ len
> eb
->start
+ eb
->len
);
5606 offset
= (start_offset
+ start
) & (PAGE_SIZE
- 1);
5609 page
= eb
->pages
[i
];
5610 WARN_ON(!PageUptodate(page
));
5612 cur
= min(len
, PAGE_SIZE
- offset
);
5613 kaddr
= page_address(page
);
5614 memset(kaddr
+ offset
, 0, cur
);
5622 void copy_extent_buffer_full(struct extent_buffer
*dst
,
5623 struct extent_buffer
*src
)
5628 ASSERT(dst
->len
== src
->len
);
5630 num_pages
= num_extent_pages(dst
->start
, dst
->len
);
5631 for (i
= 0; i
< num_pages
; i
++)
5632 copy_page(page_address(dst
->pages
[i
]),
5633 page_address(src
->pages
[i
]));
5636 void copy_extent_buffer(struct extent_buffer
*dst
, struct extent_buffer
*src
,
5637 unsigned long dst_offset
, unsigned long src_offset
,
5640 u64 dst_len
= dst
->len
;
5645 size_t start_offset
= dst
->start
& ((u64
)PAGE_SIZE
- 1);
5646 unsigned long i
= (start_offset
+ dst_offset
) >> PAGE_SHIFT
;
5648 WARN_ON(src
->len
!= dst_len
);
5650 offset
= (start_offset
+ dst_offset
) &
5654 page
= dst
->pages
[i
];
5655 WARN_ON(!PageUptodate(page
));
5657 cur
= min(len
, (unsigned long)(PAGE_SIZE
- offset
));
5659 kaddr
= page_address(page
);
5660 read_extent_buffer(src
, kaddr
+ offset
, src_offset
, cur
);
5669 void le_bitmap_set(u8
*map
, unsigned int start
, int len
)
5671 u8
*p
= map
+ BIT_BYTE(start
);
5672 const unsigned int size
= start
+ len
;
5673 int bits_to_set
= BITS_PER_BYTE
- (start
% BITS_PER_BYTE
);
5674 u8 mask_to_set
= BITMAP_FIRST_BYTE_MASK(start
);
5676 while (len
- bits_to_set
>= 0) {
5679 bits_to_set
= BITS_PER_BYTE
;
5684 mask_to_set
&= BITMAP_LAST_BYTE_MASK(size
);
5689 void le_bitmap_clear(u8
*map
, unsigned int start
, int len
)
5691 u8
*p
= map
+ BIT_BYTE(start
);
5692 const unsigned int size
= start
+ len
;
5693 int bits_to_clear
= BITS_PER_BYTE
- (start
% BITS_PER_BYTE
);
5694 u8 mask_to_clear
= BITMAP_FIRST_BYTE_MASK(start
);
5696 while (len
- bits_to_clear
>= 0) {
5697 *p
&= ~mask_to_clear
;
5698 len
-= bits_to_clear
;
5699 bits_to_clear
= BITS_PER_BYTE
;
5704 mask_to_clear
&= BITMAP_LAST_BYTE_MASK(size
);
5705 *p
&= ~mask_to_clear
;
5710 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5712 * @eb: the extent buffer
5713 * @start: offset of the bitmap item in the extent buffer
5715 * @page_index: return index of the page in the extent buffer that contains the
5717 * @page_offset: return offset into the page given by page_index
5719 * This helper hides the ugliness of finding the byte in an extent buffer which
5720 * contains a given bit.
5722 static inline void eb_bitmap_offset(struct extent_buffer
*eb
,
5723 unsigned long start
, unsigned long nr
,
5724 unsigned long *page_index
,
5725 size_t *page_offset
)
5727 size_t start_offset
= eb
->start
& ((u64
)PAGE_SIZE
- 1);
5728 size_t byte_offset
= BIT_BYTE(nr
);
5732 * The byte we want is the offset of the extent buffer + the offset of
5733 * the bitmap item in the extent buffer + the offset of the byte in the
5736 offset
= start_offset
+ start
+ byte_offset
;
5738 *page_index
= offset
>> PAGE_SHIFT
;
5739 *page_offset
= offset
& (PAGE_SIZE
- 1);
5743 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5744 * @eb: the extent buffer
5745 * @start: offset of the bitmap item in the extent buffer
5746 * @nr: bit number to test
5748 int extent_buffer_test_bit(struct extent_buffer
*eb
, unsigned long start
,
5756 eb_bitmap_offset(eb
, start
, nr
, &i
, &offset
);
5757 page
= eb
->pages
[i
];
5758 WARN_ON(!PageUptodate(page
));
5759 kaddr
= page_address(page
);
5760 return 1U & (kaddr
[offset
] >> (nr
& (BITS_PER_BYTE
- 1)));
5764 * extent_buffer_bitmap_set - set an area of a bitmap
5765 * @eb: the extent buffer
5766 * @start: offset of the bitmap item in the extent buffer
5767 * @pos: bit number of the first bit
5768 * @len: number of bits to set
5770 void extent_buffer_bitmap_set(struct extent_buffer
*eb
, unsigned long start
,
5771 unsigned long pos
, unsigned long len
)
5777 const unsigned int size
= pos
+ len
;
5778 int bits_to_set
= BITS_PER_BYTE
- (pos
% BITS_PER_BYTE
);
5779 u8 mask_to_set
= BITMAP_FIRST_BYTE_MASK(pos
);
5781 eb_bitmap_offset(eb
, start
, pos
, &i
, &offset
);
5782 page
= eb
->pages
[i
];
5783 WARN_ON(!PageUptodate(page
));
5784 kaddr
= page_address(page
);
5786 while (len
>= bits_to_set
) {
5787 kaddr
[offset
] |= mask_to_set
;
5789 bits_to_set
= BITS_PER_BYTE
;
5791 if (++offset
>= PAGE_SIZE
&& len
> 0) {
5793 page
= eb
->pages
[++i
];
5794 WARN_ON(!PageUptodate(page
));
5795 kaddr
= page_address(page
);
5799 mask_to_set
&= BITMAP_LAST_BYTE_MASK(size
);
5800 kaddr
[offset
] |= mask_to_set
;
5806 * extent_buffer_bitmap_clear - clear an area of a bitmap
5807 * @eb: the extent buffer
5808 * @start: offset of the bitmap item in the extent buffer
5809 * @pos: bit number of the first bit
5810 * @len: number of bits to clear
5812 void extent_buffer_bitmap_clear(struct extent_buffer
*eb
, unsigned long start
,
5813 unsigned long pos
, unsigned long len
)
5819 const unsigned int size
= pos
+ len
;
5820 int bits_to_clear
= BITS_PER_BYTE
- (pos
% BITS_PER_BYTE
);
5821 u8 mask_to_clear
= BITMAP_FIRST_BYTE_MASK(pos
);
5823 eb_bitmap_offset(eb
, start
, pos
, &i
, &offset
);
5824 page
= eb
->pages
[i
];
5825 WARN_ON(!PageUptodate(page
));
5826 kaddr
= page_address(page
);
5828 while (len
>= bits_to_clear
) {
5829 kaddr
[offset
] &= ~mask_to_clear
;
5830 len
-= bits_to_clear
;
5831 bits_to_clear
= BITS_PER_BYTE
;
5833 if (++offset
>= PAGE_SIZE
&& len
> 0) {
5835 page
= eb
->pages
[++i
];
5836 WARN_ON(!PageUptodate(page
));
5837 kaddr
= page_address(page
);
5841 mask_to_clear
&= BITMAP_LAST_BYTE_MASK(size
);
5842 kaddr
[offset
] &= ~mask_to_clear
;
5846 static inline bool areas_overlap(unsigned long src
, unsigned long dst
, unsigned long len
)
5848 unsigned long distance
= (src
> dst
) ? src
- dst
: dst
- src
;
5849 return distance
< len
;
5852 static void copy_pages(struct page
*dst_page
, struct page
*src_page
,
5853 unsigned long dst_off
, unsigned long src_off
,
5856 char *dst_kaddr
= page_address(dst_page
);
5858 int must_memmove
= 0;
5860 if (dst_page
!= src_page
) {
5861 src_kaddr
= page_address(src_page
);
5863 src_kaddr
= dst_kaddr
;
5864 if (areas_overlap(src_off
, dst_off
, len
))
5869 memmove(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5871 memcpy(dst_kaddr
+ dst_off
, src_kaddr
+ src_off
, len
);
5874 void memcpy_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5875 unsigned long src_offset
, unsigned long len
)
5877 struct btrfs_fs_info
*fs_info
= dst
->fs_info
;
5879 size_t dst_off_in_page
;
5880 size_t src_off_in_page
;
5881 size_t start_offset
= dst
->start
& ((u64
)PAGE_SIZE
- 1);
5882 unsigned long dst_i
;
5883 unsigned long src_i
;
5885 if (src_offset
+ len
> dst
->len
) {
5887 "memmove bogus src_offset %lu move len %lu dst len %lu",
5888 src_offset
, len
, dst
->len
);
5891 if (dst_offset
+ len
> dst
->len
) {
5893 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5894 dst_offset
, len
, dst
->len
);
5899 dst_off_in_page
= (start_offset
+ dst_offset
) &
5901 src_off_in_page
= (start_offset
+ src_offset
) &
5904 dst_i
= (start_offset
+ dst_offset
) >> PAGE_SHIFT
;
5905 src_i
= (start_offset
+ src_offset
) >> PAGE_SHIFT
;
5907 cur
= min(len
, (unsigned long)(PAGE_SIZE
-
5909 cur
= min_t(unsigned long, cur
,
5910 (unsigned long)(PAGE_SIZE
- dst_off_in_page
));
5912 copy_pages(dst
->pages
[dst_i
], dst
->pages
[src_i
],
5913 dst_off_in_page
, src_off_in_page
, cur
);
5921 void memmove_extent_buffer(struct extent_buffer
*dst
, unsigned long dst_offset
,
5922 unsigned long src_offset
, unsigned long len
)
5924 struct btrfs_fs_info
*fs_info
= dst
->fs_info
;
5926 size_t dst_off_in_page
;
5927 size_t src_off_in_page
;
5928 unsigned long dst_end
= dst_offset
+ len
- 1;
5929 unsigned long src_end
= src_offset
+ len
- 1;
5930 size_t start_offset
= dst
->start
& ((u64
)PAGE_SIZE
- 1);
5931 unsigned long dst_i
;
5932 unsigned long src_i
;
5934 if (src_offset
+ len
> dst
->len
) {
5936 "memmove bogus src_offset %lu move len %lu len %lu",
5937 src_offset
, len
, dst
->len
);
5940 if (dst_offset
+ len
> dst
->len
) {
5942 "memmove bogus dst_offset %lu move len %lu len %lu",
5943 dst_offset
, len
, dst
->len
);
5946 if (dst_offset
< src_offset
) {
5947 memcpy_extent_buffer(dst
, dst_offset
, src_offset
, len
);
5951 dst_i
= (start_offset
+ dst_end
) >> PAGE_SHIFT
;
5952 src_i
= (start_offset
+ src_end
) >> PAGE_SHIFT
;
5954 dst_off_in_page
= (start_offset
+ dst_end
) &
5956 src_off_in_page
= (start_offset
+ src_end
) &
5959 cur
= min_t(unsigned long, len
, src_off_in_page
+ 1);
5960 cur
= min(cur
, dst_off_in_page
+ 1);
5961 copy_pages(dst
->pages
[dst_i
], dst
->pages
[src_i
],
5962 dst_off_in_page
- cur
+ 1,
5963 src_off_in_page
- cur
+ 1, cur
);
5971 int try_release_extent_buffer(struct page
*page
)
5973 struct extent_buffer
*eb
;
5976 * We need to make sure nobody is attaching this page to an eb right
5979 spin_lock(&page
->mapping
->private_lock
);
5980 if (!PagePrivate(page
)) {
5981 spin_unlock(&page
->mapping
->private_lock
);
5985 eb
= (struct extent_buffer
*)page
->private;
5989 * This is a little awful but should be ok, we need to make sure that
5990 * the eb doesn't disappear out from under us while we're looking at
5993 spin_lock(&eb
->refs_lock
);
5994 if (atomic_read(&eb
->refs
) != 1 || extent_buffer_under_io(eb
)) {
5995 spin_unlock(&eb
->refs_lock
);
5996 spin_unlock(&page
->mapping
->private_lock
);
5999 spin_unlock(&page
->mapping
->private_lock
);
6002 * If tree ref isn't set then we know the ref on this eb is a real ref,
6003 * so just return, this page will likely be freed soon anyway.
6005 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF
, &eb
->bflags
)) {
6006 spin_unlock(&eb
->refs_lock
);
6010 return release_extent_buffer(eb
);