1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/bitops.h>
4 #include <linux/slab.h>
7 #include <linux/pagemap.h>
8 #include <linux/page-flags.h>
9 #include <linux/spinlock.h>
10 #include <linux/blkdev.h>
11 #include <linux/swap.h>
12 #include <linux/writeback.h>
13 #include <linux/pagevec.h>
14 #include <linux/prefetch.h>
15 #include <linux/cleancache.h>
16 #include "extent_io.h"
17 #include "extent_map.h"
19 #include "btrfs_inode.h"
21 #include "check-integrity.h"
23 #include "rcu-string.h"
27 static struct kmem_cache *extent_state_cache;
28 static struct kmem_cache *extent_buffer_cache;
29 static struct bio_set btrfs_bioset;
31 static inline bool extent_state_in_tree(const struct extent_state *state)
33 return !RB_EMPTY_NODE(&state->rb_node);
36 #ifdef CONFIG_BTRFS_DEBUG
37 static LIST_HEAD(buffers);
38 static LIST_HEAD(states);
40 static DEFINE_SPINLOCK(leak_lock);
43 void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
47 spin_lock_irqsave(&leak_lock, flags);
49 spin_unlock_irqrestore(&leak_lock, flags);
53 void btrfs_leak_debug_del(struct list_head *entry)
57 spin_lock_irqsave(&leak_lock, flags);
59 spin_unlock_irqrestore(&leak_lock, flags);
63 void btrfs_leak_debug_check(void)
65 struct extent_state *state;
66 struct extent_buffer *eb;
68 while (!list_empty(&states)) {
69 state = list_entry(states.next, struct extent_state, leak_list);
70 pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
71 state->start, state->end, state->state,
72 extent_state_in_tree(state),
73 refcount_read(&state->refs));
74 list_del(&state->leak_list);
75 kmem_cache_free(extent_state_cache, state);
78 while (!list_empty(&buffers)) {
79 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
80 pr_err("BTRFS: buffer leak start %llu len %lu refs %d bflags %lu\n",
81 eb->start, eb->len, atomic_read(&eb->refs), eb->bflags);
82 list_del(&eb->leak_list);
83 kmem_cache_free(extent_buffer_cache, eb);
87 #define btrfs_debug_check_extent_io_range(tree, start, end) \
88 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
89 static inline void __btrfs_debug_check_extent_io_range(const char *caller,
90 struct extent_io_tree *tree, u64 start, u64 end)
92 struct inode *inode = tree->private_data;
95 if (!inode || !is_data_inode(inode))
98 isize = i_size_read(inode);
99 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
100 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
101 "%s: ino %llu isize %llu odd range [%llu,%llu]",
102 caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
106 #define btrfs_leak_debug_add(new, head) do {} while (0)
107 #define btrfs_leak_debug_del(entry) do {} while (0)
108 #define btrfs_leak_debug_check() do {} while (0)
109 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
115 struct rb_node rb_node;
118 struct extent_page_data {
120 struct extent_io_tree *tree;
121 /* tells writepage not to lock the state bits for this range
122 * it still does the unlocking
124 unsigned int extent_locked:1;
126 /* tells the submit_bio code to use REQ_SYNC */
127 unsigned int sync_io:1;
130 static int add_extent_changeset(struct extent_state *state, unsigned bits,
131 struct extent_changeset *changeset,
138 if (set && (state->state & bits) == bits)
140 if (!set && (state->state & bits) == 0)
142 changeset->bytes_changed += state->end - state->start + 1;
143 ret = ulist_add(&changeset->range_changed, state->start, state->end,
148 static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
149 unsigned long bio_flags)
151 blk_status_t ret = 0;
152 struct extent_io_tree *tree = bio->bi_private;
154 bio->bi_private = NULL;
157 ret = tree->ops->submit_bio_hook(tree->private_data, bio,
158 mirror_num, bio_flags);
160 btrfsic_submit_bio(bio);
162 return blk_status_to_errno(ret);
165 /* Cleanup unsubmitted bios */
166 static void end_write_bio(struct extent_page_data *epd, int ret)
169 epd->bio->bi_status = errno_to_blk_status(ret);
176 * Submit bio from extent page data via submit_one_bio
178 * Return 0 if everything is OK.
179 * Return <0 for error.
181 static int __must_check flush_write_bio(struct extent_page_data *epd)
186 ret = submit_one_bio(epd->bio, 0, 0);
188 * Clean up of epd->bio is handled by its endio function.
189 * And endio is either triggered by successful bio execution
190 * or the error handler of submit bio hook.
191 * So at this point, no matter what happened, we don't need
192 * to clean up epd->bio.
199 int __init extent_io_init(void)
201 extent_state_cache = kmem_cache_create("btrfs_extent_state",
202 sizeof(struct extent_state), 0,
203 SLAB_MEM_SPREAD, NULL);
204 if (!extent_state_cache)
207 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
208 sizeof(struct extent_buffer), 0,
209 SLAB_MEM_SPREAD, NULL);
210 if (!extent_buffer_cache)
211 goto free_state_cache;
213 if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE,
214 offsetof(struct btrfs_io_bio, bio),
216 goto free_buffer_cache;
218 if (bioset_integrity_create(&btrfs_bioset, BIO_POOL_SIZE))
224 bioset_exit(&btrfs_bioset);
227 kmem_cache_destroy(extent_buffer_cache);
228 extent_buffer_cache = NULL;
231 kmem_cache_destroy(extent_state_cache);
232 extent_state_cache = NULL;
236 void __cold extent_io_exit(void)
238 btrfs_leak_debug_check();
241 * Make sure all delayed rcu free are flushed before we
245 kmem_cache_destroy(extent_state_cache);
246 kmem_cache_destroy(extent_buffer_cache);
247 bioset_exit(&btrfs_bioset);
250 void extent_io_tree_init(struct btrfs_fs_info *fs_info,
251 struct extent_io_tree *tree, unsigned int owner,
254 tree->fs_info = fs_info;
255 tree->state = RB_ROOT;
257 tree->dirty_bytes = 0;
258 spin_lock_init(&tree->lock);
259 tree->private_data = private_data;
263 void extent_io_tree_release(struct extent_io_tree *tree)
265 spin_lock(&tree->lock);
267 * Do a single barrier for the waitqueue_active check here, the state
268 * of the waitqueue should not change once extent_io_tree_release is
272 while (!RB_EMPTY_ROOT(&tree->state)) {
273 struct rb_node *node;
274 struct extent_state *state;
276 node = rb_first(&tree->state);
277 state = rb_entry(node, struct extent_state, rb_node);
278 rb_erase(&state->rb_node, &tree->state);
279 RB_CLEAR_NODE(&state->rb_node);
281 * btree io trees aren't supposed to have tasks waiting for
282 * changes in the flags of extent states ever.
284 ASSERT(!waitqueue_active(&state->wq));
285 free_extent_state(state);
287 cond_resched_lock(&tree->lock);
289 spin_unlock(&tree->lock);
292 static struct extent_state *alloc_extent_state(gfp_t mask)
294 struct extent_state *state;
297 * The given mask might be not appropriate for the slab allocator,
298 * drop the unsupported bits
300 mask &= ~(__GFP_DMA32|__GFP_HIGHMEM);
301 state = kmem_cache_alloc(extent_state_cache, mask);
305 state->failrec = NULL;
306 RB_CLEAR_NODE(&state->rb_node);
307 btrfs_leak_debug_add(&state->leak_list, &states);
308 refcount_set(&state->refs, 1);
309 init_waitqueue_head(&state->wq);
310 trace_alloc_extent_state(state, mask, _RET_IP_);
314 void free_extent_state(struct extent_state *state)
318 if (refcount_dec_and_test(&state->refs)) {
319 WARN_ON(extent_state_in_tree(state));
320 btrfs_leak_debug_del(&state->leak_list);
321 trace_free_extent_state(state, _RET_IP_);
322 kmem_cache_free(extent_state_cache, state);
326 static struct rb_node *tree_insert(struct rb_root *root,
327 struct rb_node *search_start,
329 struct rb_node *node,
330 struct rb_node ***p_in,
331 struct rb_node **parent_in)
334 struct rb_node *parent = NULL;
335 struct tree_entry *entry;
337 if (p_in && parent_in) {
343 p = search_start ? &search_start : &root->rb_node;
346 entry = rb_entry(parent, struct tree_entry, rb_node);
348 if (offset < entry->start)
350 else if (offset > entry->end)
357 rb_link_node(node, parent, p);
358 rb_insert_color(node, root);
362 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
363 struct rb_node **next_ret,
364 struct rb_node **prev_ret,
365 struct rb_node ***p_ret,
366 struct rb_node **parent_ret)
368 struct rb_root *root = &tree->state;
369 struct rb_node **n = &root->rb_node;
370 struct rb_node *prev = NULL;
371 struct rb_node *orig_prev = NULL;
372 struct tree_entry *entry;
373 struct tree_entry *prev_entry = NULL;
377 entry = rb_entry(prev, struct tree_entry, rb_node);
380 if (offset < entry->start)
382 else if (offset > entry->end)
395 while (prev && offset > prev_entry->end) {
396 prev = rb_next(prev);
397 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
404 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
405 while (prev && offset < prev_entry->start) {
406 prev = rb_prev(prev);
407 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
414 static inline struct rb_node *
415 tree_search_for_insert(struct extent_io_tree *tree,
417 struct rb_node ***p_ret,
418 struct rb_node **parent_ret)
420 struct rb_node *next= NULL;
423 ret = __etree_search(tree, offset, &next, NULL, p_ret, parent_ret);
429 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
432 return tree_search_for_insert(tree, offset, NULL, NULL);
436 * utility function to look for merge candidates inside a given range.
437 * Any extents with matching state are merged together into a single
438 * extent in the tree. Extents with EXTENT_IO in their state field
439 * are not merged because the end_io handlers need to be able to do
440 * operations on them without sleeping (or doing allocations/splits).
442 * This should be called with the tree lock held.
444 static void merge_state(struct extent_io_tree *tree,
445 struct extent_state *state)
447 struct extent_state *other;
448 struct rb_node *other_node;
450 if (state->state & (EXTENT_LOCKED | EXTENT_BOUNDARY))
453 other_node = rb_prev(&state->rb_node);
455 other = rb_entry(other_node, struct extent_state, rb_node);
456 if (other->end == state->start - 1 &&
457 other->state == state->state) {
458 if (tree->private_data &&
459 is_data_inode(tree->private_data))
460 btrfs_merge_delalloc_extent(tree->private_data,
462 state->start = other->start;
463 rb_erase(&other->rb_node, &tree->state);
464 RB_CLEAR_NODE(&other->rb_node);
465 free_extent_state(other);
468 other_node = rb_next(&state->rb_node);
470 other = rb_entry(other_node, struct extent_state, rb_node);
471 if (other->start == state->end + 1 &&
472 other->state == state->state) {
473 if (tree->private_data &&
474 is_data_inode(tree->private_data))
475 btrfs_merge_delalloc_extent(tree->private_data,
477 state->end = other->end;
478 rb_erase(&other->rb_node, &tree->state);
479 RB_CLEAR_NODE(&other->rb_node);
480 free_extent_state(other);
485 static void set_state_bits(struct extent_io_tree *tree,
486 struct extent_state *state, unsigned *bits,
487 struct extent_changeset *changeset);
490 * insert an extent_state struct into the tree. 'bits' are set on the
491 * struct before it is inserted.
493 * This may return -EEXIST if the extent is already there, in which case the
494 * state struct is freed.
496 * The tree lock is not taken internally. This is a utility function and
497 * probably isn't what you want to call (see set/clear_extent_bit).
499 static int insert_state(struct extent_io_tree *tree,
500 struct extent_state *state, u64 start, u64 end,
502 struct rb_node **parent,
503 unsigned *bits, struct extent_changeset *changeset)
505 struct rb_node *node;
508 WARN(1, KERN_ERR "BTRFS: end < start %llu %llu\n",
510 state->start = start;
513 set_state_bits(tree, state, bits, changeset);
515 node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
517 struct extent_state *found;
518 found = rb_entry(node, struct extent_state, rb_node);
519 pr_err("BTRFS: found node %llu %llu on insert of %llu %llu\n",
520 found->start, found->end, start, end);
523 merge_state(tree, state);
528 * split a given extent state struct in two, inserting the preallocated
529 * struct 'prealloc' as the newly created second half. 'split' indicates an
530 * offset inside 'orig' where it should be split.
533 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
534 * are two extent state structs in the tree:
535 * prealloc: [orig->start, split - 1]
536 * orig: [ split, orig->end ]
538 * The tree locks are not taken by this function. They need to be held
541 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
542 struct extent_state *prealloc, u64 split)
544 struct rb_node *node;
546 if (tree->private_data && is_data_inode(tree->private_data))
547 btrfs_split_delalloc_extent(tree->private_data, orig, split);
549 prealloc->start = orig->start;
550 prealloc->end = split - 1;
551 prealloc->state = orig->state;
554 node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
555 &prealloc->rb_node, NULL, NULL);
557 free_extent_state(prealloc);
563 static struct extent_state *next_state(struct extent_state *state)
565 struct rb_node *next = rb_next(&state->rb_node);
567 return rb_entry(next, struct extent_state, rb_node);
573 * utility function to clear some bits in an extent state struct.
574 * it will optionally wake up anyone waiting on this state (wake == 1).
576 * If no bits are set on the state struct after clearing things, the
577 * struct is freed and removed from the tree
579 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
580 struct extent_state *state,
581 unsigned *bits, int wake,
582 struct extent_changeset *changeset)
584 struct extent_state *next;
585 unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
588 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
589 u64 range = state->end - state->start + 1;
590 WARN_ON(range > tree->dirty_bytes);
591 tree->dirty_bytes -= range;
594 if (tree->private_data && is_data_inode(tree->private_data))
595 btrfs_clear_delalloc_extent(tree->private_data, state, bits);
597 ret = add_extent_changeset(state, bits_to_clear, changeset, 0);
599 state->state &= ~bits_to_clear;
602 if (state->state == 0) {
603 next = next_state(state);
604 if (extent_state_in_tree(state)) {
605 rb_erase(&state->rb_node, &tree->state);
606 RB_CLEAR_NODE(&state->rb_node);
607 free_extent_state(state);
612 merge_state(tree, state);
613 next = next_state(state);
618 static struct extent_state *
619 alloc_extent_state_atomic(struct extent_state *prealloc)
622 prealloc = alloc_extent_state(GFP_ATOMIC);
627 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
629 struct inode *inode = tree->private_data;
631 btrfs_panic(btrfs_sb(inode->i_sb), err,
632 "locking error: extent tree was modified by another thread while locked");
636 * clear some bits on a range in the tree. This may require splitting
637 * or inserting elements in the tree, so the gfp mask is used to
638 * indicate which allocations or sleeping are allowed.
640 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
641 * the given range from the tree regardless of state (ie for truncate).
643 * the range [start, end] is inclusive.
645 * This takes the tree lock, and returns 0 on success and < 0 on error.
647 int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
648 unsigned bits, int wake, int delete,
649 struct extent_state **cached_state,
650 gfp_t mask, struct extent_changeset *changeset)
652 struct extent_state *state;
653 struct extent_state *cached;
654 struct extent_state *prealloc = NULL;
655 struct rb_node *node;
660 btrfs_debug_check_extent_io_range(tree, start, end);
661 trace_btrfs_clear_extent_bit(tree, start, end - start + 1, bits);
663 if (bits & EXTENT_DELALLOC)
664 bits |= EXTENT_NORESERVE;
667 bits |= ~EXTENT_CTLBITS;
669 if (bits & (EXTENT_LOCKED | EXTENT_BOUNDARY))
672 if (!prealloc && gfpflags_allow_blocking(mask)) {
674 * Don't care for allocation failure here because we might end
675 * up not needing the pre-allocated extent state at all, which
676 * is the case if we only have in the tree extent states that
677 * cover our input range and don't cover too any other range.
678 * If we end up needing a new extent state we allocate it later.
680 prealloc = alloc_extent_state(mask);
683 spin_lock(&tree->lock);
685 cached = *cached_state;
688 *cached_state = NULL;
692 if (cached && extent_state_in_tree(cached) &&
693 cached->start <= start && cached->end > start) {
695 refcount_dec(&cached->refs);
700 free_extent_state(cached);
703 * this search will find the extents that end after
706 node = tree_search(tree, start);
709 state = rb_entry(node, struct extent_state, rb_node);
711 if (state->start > end)
713 WARN_ON(state->end < start);
714 last_end = state->end;
716 /* the state doesn't have the wanted bits, go ahead */
717 if (!(state->state & bits)) {
718 state = next_state(state);
723 * | ---- desired range ---- |
725 * | ------------- state -------------- |
727 * We need to split the extent we found, and may flip
728 * bits on second half.
730 * If the extent we found extends past our range, we
731 * just split and search again. It'll get split again
732 * the next time though.
734 * If the extent we found is inside our range, we clear
735 * the desired bit on it.
738 if (state->start < start) {
739 prealloc = alloc_extent_state_atomic(prealloc);
741 err = split_state(tree, state, prealloc, start);
743 extent_io_tree_panic(tree, err);
748 if (state->end <= end) {
749 state = clear_state_bit(tree, state, &bits, wake,
756 * | ---- desired range ---- |
758 * We need to split the extent, and clear the bit
761 if (state->start <= end && state->end > end) {
762 prealloc = alloc_extent_state_atomic(prealloc);
764 err = split_state(tree, state, prealloc, end + 1);
766 extent_io_tree_panic(tree, err);
771 clear_state_bit(tree, prealloc, &bits, wake, changeset);
777 state = clear_state_bit(tree, state, &bits, wake, changeset);
779 if (last_end == (u64)-1)
781 start = last_end + 1;
782 if (start <= end && state && !need_resched())
788 spin_unlock(&tree->lock);
789 if (gfpflags_allow_blocking(mask))
794 spin_unlock(&tree->lock);
796 free_extent_state(prealloc);
802 static void wait_on_state(struct extent_io_tree *tree,
803 struct extent_state *state)
804 __releases(tree->lock)
805 __acquires(tree->lock)
808 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
809 spin_unlock(&tree->lock);
811 spin_lock(&tree->lock);
812 finish_wait(&state->wq, &wait);
816 * waits for one or more bits to clear on a range in the state tree.
817 * The range [start, end] is inclusive.
818 * The tree lock is taken by this function
820 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
823 struct extent_state *state;
824 struct rb_node *node;
826 btrfs_debug_check_extent_io_range(tree, start, end);
828 spin_lock(&tree->lock);
832 * this search will find all the extents that end after
835 node = tree_search(tree, start);
840 state = rb_entry(node, struct extent_state, rb_node);
842 if (state->start > end)
845 if (state->state & bits) {
846 start = state->start;
847 refcount_inc(&state->refs);
848 wait_on_state(tree, state);
849 free_extent_state(state);
852 start = state->end + 1;
857 if (!cond_resched_lock(&tree->lock)) {
858 node = rb_next(node);
863 spin_unlock(&tree->lock);
866 static void set_state_bits(struct extent_io_tree *tree,
867 struct extent_state *state,
868 unsigned *bits, struct extent_changeset *changeset)
870 unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
873 if (tree->private_data && is_data_inode(tree->private_data))
874 btrfs_set_delalloc_extent(tree->private_data, state, bits);
876 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
877 u64 range = state->end - state->start + 1;
878 tree->dirty_bytes += range;
880 ret = add_extent_changeset(state, bits_to_set, changeset, 1);
882 state->state |= bits_to_set;
885 static void cache_state_if_flags(struct extent_state *state,
886 struct extent_state **cached_ptr,
889 if (cached_ptr && !(*cached_ptr)) {
890 if (!flags || (state->state & flags)) {
892 refcount_inc(&state->refs);
897 static void cache_state(struct extent_state *state,
898 struct extent_state **cached_ptr)
900 return cache_state_if_flags(state, cached_ptr,
901 EXTENT_LOCKED | EXTENT_BOUNDARY);
905 * set some bits on a range in the tree. This may require allocations or
906 * sleeping, so the gfp mask is used to indicate what is allowed.
908 * If any of the exclusive bits are set, this will fail with -EEXIST if some
909 * part of the range already has the desired bits set. The start of the
910 * existing range is returned in failed_start in this case.
912 * [start, end] is inclusive This takes the tree lock.
915 static int __must_check
916 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
917 unsigned bits, unsigned exclusive_bits,
918 u64 *failed_start, struct extent_state **cached_state,
919 gfp_t mask, struct extent_changeset *changeset)
921 struct extent_state *state;
922 struct extent_state *prealloc = NULL;
923 struct rb_node *node;
925 struct rb_node *parent;
930 btrfs_debug_check_extent_io_range(tree, start, end);
931 trace_btrfs_set_extent_bit(tree, start, end - start + 1, bits);
934 if (!prealloc && gfpflags_allow_blocking(mask)) {
936 * Don't care for allocation failure here because we might end
937 * up not needing the pre-allocated extent state at all, which
938 * is the case if we only have in the tree extent states that
939 * cover our input range and don't cover too any other range.
940 * If we end up needing a new extent state we allocate it later.
942 prealloc = alloc_extent_state(mask);
945 spin_lock(&tree->lock);
946 if (cached_state && *cached_state) {
947 state = *cached_state;
948 if (state->start <= start && state->end > start &&
949 extent_state_in_tree(state)) {
950 node = &state->rb_node;
955 * this search will find all the extents that end after
958 node = tree_search_for_insert(tree, start, &p, &parent);
960 prealloc = alloc_extent_state_atomic(prealloc);
962 err = insert_state(tree, prealloc, start, end,
963 &p, &parent, &bits, changeset);
965 extent_io_tree_panic(tree, err);
967 cache_state(prealloc, cached_state);
971 state = rb_entry(node, struct extent_state, rb_node);
973 last_start = state->start;
974 last_end = state->end;
977 * | ---- desired range ---- |
980 * Just lock what we found and keep going
982 if (state->start == start && state->end <= end) {
983 if (state->state & exclusive_bits) {
984 *failed_start = state->start;
989 set_state_bits(tree, state, &bits, changeset);
990 cache_state(state, cached_state);
991 merge_state(tree, state);
992 if (last_end == (u64)-1)
994 start = last_end + 1;
995 state = next_state(state);
996 if (start < end && state && state->start == start &&
1003 * | ---- desired range ---- |
1006 * | ------------- state -------------- |
1008 * We need to split the extent we found, and may flip bits on
1011 * If the extent we found extends past our
1012 * range, we just split and search again. It'll get split
1013 * again the next time though.
1015 * If the extent we found is inside our range, we set the
1016 * desired bit on it.
1018 if (state->start < start) {
1019 if (state->state & exclusive_bits) {
1020 *failed_start = start;
1025 prealloc = alloc_extent_state_atomic(prealloc);
1027 err = split_state(tree, state, prealloc, start);
1029 extent_io_tree_panic(tree, err);
1034 if (state->end <= end) {
1035 set_state_bits(tree, state, &bits, changeset);
1036 cache_state(state, cached_state);
1037 merge_state(tree, state);
1038 if (last_end == (u64)-1)
1040 start = last_end + 1;
1041 state = next_state(state);
1042 if (start < end && state && state->start == start &&
1049 * | ---- desired range ---- |
1050 * | state | or | state |
1052 * There's a hole, we need to insert something in it and
1053 * ignore the extent we found.
1055 if (state->start > start) {
1057 if (end < last_start)
1060 this_end = last_start - 1;
1062 prealloc = alloc_extent_state_atomic(prealloc);
1066 * Avoid to free 'prealloc' if it can be merged with
1069 err = insert_state(tree, prealloc, start, this_end,
1070 NULL, NULL, &bits, changeset);
1072 extent_io_tree_panic(tree, err);
1074 cache_state(prealloc, cached_state);
1076 start = this_end + 1;
1080 * | ---- desired range ---- |
1082 * We need to split the extent, and set the bit
1085 if (state->start <= end && state->end > end) {
1086 if (state->state & exclusive_bits) {
1087 *failed_start = start;
1092 prealloc = alloc_extent_state_atomic(prealloc);
1094 err = split_state(tree, state, prealloc, end + 1);
1096 extent_io_tree_panic(tree, err);
1098 set_state_bits(tree, prealloc, &bits, changeset);
1099 cache_state(prealloc, cached_state);
1100 merge_state(tree, prealloc);
1108 spin_unlock(&tree->lock);
1109 if (gfpflags_allow_blocking(mask))
1114 spin_unlock(&tree->lock);
1116 free_extent_state(prealloc);
1122 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1123 unsigned bits, u64 * failed_start,
1124 struct extent_state **cached_state, gfp_t mask)
1126 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
1127 cached_state, mask, NULL);
1132 * convert_extent_bit - convert all bits in a given range from one bit to
1134 * @tree: the io tree to search
1135 * @start: the start offset in bytes
1136 * @end: the end offset in bytes (inclusive)
1137 * @bits: the bits to set in this range
1138 * @clear_bits: the bits to clear in this range
1139 * @cached_state: state that we're going to cache
1141 * This will go through and set bits for the given range. If any states exist
1142 * already in this range they are set with the given bit and cleared of the
1143 * clear_bits. This is only meant to be used by things that are mergeable, ie
1144 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1145 * boundary bits like LOCK.
1147 * All allocations are done with GFP_NOFS.
1149 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1150 unsigned bits, unsigned clear_bits,
1151 struct extent_state **cached_state)
1153 struct extent_state *state;
1154 struct extent_state *prealloc = NULL;
1155 struct rb_node *node;
1157 struct rb_node *parent;
1161 bool first_iteration = true;
1163 btrfs_debug_check_extent_io_range(tree, start, end);
1164 trace_btrfs_convert_extent_bit(tree, start, end - start + 1, bits,
1170 * Best effort, don't worry if extent state allocation fails
1171 * here for the first iteration. We might have a cached state
1172 * that matches exactly the target range, in which case no
1173 * extent state allocations are needed. We'll only know this
1174 * after locking the tree.
1176 prealloc = alloc_extent_state(GFP_NOFS);
1177 if (!prealloc && !first_iteration)
1181 spin_lock(&tree->lock);
1182 if (cached_state && *cached_state) {
1183 state = *cached_state;
1184 if (state->start <= start && state->end > start &&
1185 extent_state_in_tree(state)) {
1186 node = &state->rb_node;
1192 * this search will find all the extents that end after
1195 node = tree_search_for_insert(tree, start, &p, &parent);
1197 prealloc = alloc_extent_state_atomic(prealloc);
1202 err = insert_state(tree, prealloc, start, end,
1203 &p, &parent, &bits, NULL);
1205 extent_io_tree_panic(tree, err);
1206 cache_state(prealloc, cached_state);
1210 state = rb_entry(node, struct extent_state, rb_node);
1212 last_start = state->start;
1213 last_end = state->end;
1216 * | ---- desired range ---- |
1219 * Just lock what we found and keep going
1221 if (state->start == start && state->end <= end) {
1222 set_state_bits(tree, state, &bits, NULL);
1223 cache_state(state, cached_state);
1224 state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
1225 if (last_end == (u64)-1)
1227 start = last_end + 1;
1228 if (start < end && state && state->start == start &&
1235 * | ---- desired range ---- |
1238 * | ------------- state -------------- |
1240 * We need to split the extent we found, and may flip bits on
1243 * If the extent we found extends past our
1244 * range, we just split and search again. It'll get split
1245 * again the next time though.
1247 * If the extent we found is inside our range, we set the
1248 * desired bit on it.
1250 if (state->start < start) {
1251 prealloc = alloc_extent_state_atomic(prealloc);
1256 err = split_state(tree, state, prealloc, start);
1258 extent_io_tree_panic(tree, err);
1262 if (state->end <= end) {
1263 set_state_bits(tree, state, &bits, NULL);
1264 cache_state(state, cached_state);
1265 state = clear_state_bit(tree, state, &clear_bits, 0,
1267 if (last_end == (u64)-1)
1269 start = last_end + 1;
1270 if (start < end && state && state->start == start &&
1277 * | ---- desired range ---- |
1278 * | state | or | state |
1280 * There's a hole, we need to insert something in it and
1281 * ignore the extent we found.
1283 if (state->start > start) {
1285 if (end < last_start)
1288 this_end = last_start - 1;
1290 prealloc = alloc_extent_state_atomic(prealloc);
1297 * Avoid to free 'prealloc' if it can be merged with
1300 err = insert_state(tree, prealloc, start, this_end,
1301 NULL, NULL, &bits, NULL);
1303 extent_io_tree_panic(tree, err);
1304 cache_state(prealloc, cached_state);
1306 start = this_end + 1;
1310 * | ---- desired range ---- |
1312 * We need to split the extent, and set the bit
1315 if (state->start <= end && state->end > end) {
1316 prealloc = alloc_extent_state_atomic(prealloc);
1322 err = split_state(tree, state, prealloc, end + 1);
1324 extent_io_tree_panic(tree, err);
1326 set_state_bits(tree, prealloc, &bits, NULL);
1327 cache_state(prealloc, cached_state);
1328 clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
1336 spin_unlock(&tree->lock);
1338 first_iteration = false;
1342 spin_unlock(&tree->lock);
1344 free_extent_state(prealloc);
1349 /* wrappers around set/clear extent bit */
1350 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1351 unsigned bits, struct extent_changeset *changeset)
1354 * We don't support EXTENT_LOCKED yet, as current changeset will
1355 * record any bits changed, so for EXTENT_LOCKED case, it will
1356 * either fail with -EEXIST or changeset will record the whole
1359 BUG_ON(bits & EXTENT_LOCKED);
1361 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
1365 int set_extent_bits_nowait(struct extent_io_tree *tree, u64 start, u64 end,
1368 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL,
1372 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1373 unsigned bits, int wake, int delete,
1374 struct extent_state **cached)
1376 return __clear_extent_bit(tree, start, end, bits, wake, delete,
1377 cached, GFP_NOFS, NULL);
1380 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1381 unsigned bits, struct extent_changeset *changeset)
1384 * Don't support EXTENT_LOCKED case, same reason as
1385 * set_record_extent_bits().
1387 BUG_ON(bits & EXTENT_LOCKED);
1389 return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
1394 * either insert or lock state struct between start and end use mask to tell
1395 * us if waiting is desired.
1397 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1398 struct extent_state **cached_state)
1404 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
1405 EXTENT_LOCKED, &failed_start,
1406 cached_state, GFP_NOFS, NULL);
1407 if (err == -EEXIST) {
1408 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1409 start = failed_start;
1412 WARN_ON(start > end);
1417 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1422 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1423 &failed_start, NULL, GFP_NOFS, NULL);
1424 if (err == -EEXIST) {
1425 if (failed_start > start)
1426 clear_extent_bit(tree, start, failed_start - 1,
1427 EXTENT_LOCKED, 1, 0, NULL);
1433 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1435 unsigned long index = start >> PAGE_SHIFT;
1436 unsigned long end_index = end >> PAGE_SHIFT;
1439 while (index <= end_index) {
1440 page = find_get_page(inode->i_mapping, index);
1441 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1442 clear_page_dirty_for_io(page);
1448 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1450 unsigned long index = start >> PAGE_SHIFT;
1451 unsigned long end_index = end >> PAGE_SHIFT;
1454 while (index <= end_index) {
1455 page = find_get_page(inode->i_mapping, index);
1456 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1457 __set_page_dirty_nobuffers(page);
1458 account_page_redirty(page);
1464 /* find the first state struct with 'bits' set after 'start', and
1465 * return it. tree->lock must be held. NULL will returned if
1466 * nothing was found after 'start'
1468 static struct extent_state *
1469 find_first_extent_bit_state(struct extent_io_tree *tree,
1470 u64 start, unsigned bits)
1472 struct rb_node *node;
1473 struct extent_state *state;
1476 * this search will find all the extents that end after
1479 node = tree_search(tree, start);
1484 state = rb_entry(node, struct extent_state, rb_node);
1485 if (state->end >= start && (state->state & bits))
1488 node = rb_next(node);
1497 * find the first offset in the io tree with 'bits' set. zero is
1498 * returned if we find something, and *start_ret and *end_ret are
1499 * set to reflect the state struct that was found.
1501 * If nothing was found, 1 is returned. If found something, return 0.
1503 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1504 u64 *start_ret, u64 *end_ret, unsigned bits,
1505 struct extent_state **cached_state)
1507 struct extent_state *state;
1510 spin_lock(&tree->lock);
1511 if (cached_state && *cached_state) {
1512 state = *cached_state;
1513 if (state->end == start - 1 && extent_state_in_tree(state)) {
1514 while ((state = next_state(state)) != NULL) {
1515 if (state->state & bits)
1518 free_extent_state(*cached_state);
1519 *cached_state = NULL;
1522 free_extent_state(*cached_state);
1523 *cached_state = NULL;
1526 state = find_first_extent_bit_state(tree, start, bits);
1529 cache_state_if_flags(state, cached_state, 0);
1530 *start_ret = state->start;
1531 *end_ret = state->end;
1535 spin_unlock(&tree->lock);
1540 * find_first_clear_extent_bit - finds the first range that has @bits not set
1541 * and that starts after @start
1543 * @tree - the tree to search
1544 * @start - the offset at/after which the found extent should start
1545 * @start_ret - records the beginning of the range
1546 * @end_ret - records the end of the range (inclusive)
1547 * @bits - the set of bits which must be unset
1549 * Since unallocated range is also considered one which doesn't have the bits
1550 * set it's possible that @end_ret contains -1, this happens in case the range
1551 * spans (last_range_end, end of device]. In this case it's up to the caller to
1552 * trim @end_ret to the appropriate size.
1554 void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start,
1555 u64 *start_ret, u64 *end_ret, unsigned bits)
1557 struct extent_state *state;
1558 struct rb_node *node, *prev = NULL, *next;
1560 spin_lock(&tree->lock);
1562 /* Find first extent with bits cleared */
1564 node = __etree_search(tree, start, &next, &prev, NULL, NULL);
1569 * We are past the last allocated chunk,
1570 * set start at the end of the last extent. The
1571 * device alloc tree should never be empty so
1572 * prev is always set.
1575 state = rb_entry(prev, struct extent_state, rb_node);
1576 *start_ret = state->end + 1;
1581 state = rb_entry(node, struct extent_state, rb_node);
1582 if (in_range(start, state->start, state->end - state->start + 1) &&
1583 (state->state & bits)) {
1584 start = state->end + 1;
1592 * Find the longest stretch from start until an entry which has the
1596 state = rb_entry(node, struct extent_state, rb_node);
1597 if (state->end >= start && !(state->state & bits)) {
1598 *end_ret = state->end;
1600 *end_ret = state->start - 1;
1604 node = rb_next(node);
1609 spin_unlock(&tree->lock);
1613 * find a contiguous range of bytes in the file marked as delalloc, not
1614 * more than 'max_bytes'. start and end are used to return the range,
1616 * true is returned if we find something, false if nothing was in the tree
1618 static noinline bool find_delalloc_range(struct extent_io_tree *tree,
1619 u64 *start, u64 *end, u64 max_bytes,
1620 struct extent_state **cached_state)
1622 struct rb_node *node;
1623 struct extent_state *state;
1624 u64 cur_start = *start;
1626 u64 total_bytes = 0;
1628 spin_lock(&tree->lock);
1631 * this search will find all the extents that end after
1634 node = tree_search(tree, cur_start);
1641 state = rb_entry(node, struct extent_state, rb_node);
1642 if (found && (state->start != cur_start ||
1643 (state->state & EXTENT_BOUNDARY))) {
1646 if (!(state->state & EXTENT_DELALLOC)) {
1652 *start = state->start;
1653 *cached_state = state;
1654 refcount_inc(&state->refs);
1658 cur_start = state->end + 1;
1659 node = rb_next(node);
1660 total_bytes += state->end - state->start + 1;
1661 if (total_bytes >= max_bytes)
1667 spin_unlock(&tree->lock);
1671 static int __process_pages_contig(struct address_space *mapping,
1672 struct page *locked_page,
1673 pgoff_t start_index, pgoff_t end_index,
1674 unsigned long page_ops, pgoff_t *index_ret);
1676 static noinline void __unlock_for_delalloc(struct inode *inode,
1677 struct page *locked_page,
1680 unsigned long index = start >> PAGE_SHIFT;
1681 unsigned long end_index = end >> PAGE_SHIFT;
1683 ASSERT(locked_page);
1684 if (index == locked_page->index && end_index == index)
1687 __process_pages_contig(inode->i_mapping, locked_page, index, end_index,
1691 static noinline int lock_delalloc_pages(struct inode *inode,
1692 struct page *locked_page,
1696 unsigned long index = delalloc_start >> PAGE_SHIFT;
1697 unsigned long index_ret = index;
1698 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1701 ASSERT(locked_page);
1702 if (index == locked_page->index && index == end_index)
1705 ret = __process_pages_contig(inode->i_mapping, locked_page, index,
1706 end_index, PAGE_LOCK, &index_ret);
1708 __unlock_for_delalloc(inode, locked_page, delalloc_start,
1709 (u64)index_ret << PAGE_SHIFT);
1714 * Find and lock a contiguous range of bytes in the file marked as delalloc, no
1715 * more than @max_bytes. @Start and @end are used to return the range,
1717 * Return: true if we find something
1718 * false if nothing was in the tree
1721 noinline_for_stack bool find_lock_delalloc_range(struct inode *inode,
1722 struct extent_io_tree *tree,
1723 struct page *locked_page, u64 *start,
1726 u64 max_bytes = BTRFS_MAX_EXTENT_SIZE;
1730 struct extent_state *cached_state = NULL;
1735 /* step one, find a bunch of delalloc bytes starting at start */
1736 delalloc_start = *start;
1738 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1739 max_bytes, &cached_state);
1740 if (!found || delalloc_end <= *start) {
1741 *start = delalloc_start;
1742 *end = delalloc_end;
1743 free_extent_state(cached_state);
1748 * start comes from the offset of locked_page. We have to lock
1749 * pages in order, so we can't process delalloc bytes before
1752 if (delalloc_start < *start)
1753 delalloc_start = *start;
1756 * make sure to limit the number of pages we try to lock down
1758 if (delalloc_end + 1 - delalloc_start > max_bytes)
1759 delalloc_end = delalloc_start + max_bytes - 1;
1761 /* step two, lock all the pages after the page that has start */
1762 ret = lock_delalloc_pages(inode, locked_page,
1763 delalloc_start, delalloc_end);
1764 ASSERT(!ret || ret == -EAGAIN);
1765 if (ret == -EAGAIN) {
1766 /* some of the pages are gone, lets avoid looping by
1767 * shortening the size of the delalloc range we're searching
1769 free_extent_state(cached_state);
1770 cached_state = NULL;
1772 max_bytes = PAGE_SIZE;
1781 /* step three, lock the state bits for the whole range */
1782 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1784 /* then test to make sure it is all still delalloc */
1785 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1786 EXTENT_DELALLOC, 1, cached_state);
1788 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1790 __unlock_for_delalloc(inode, locked_page,
1791 delalloc_start, delalloc_end);
1795 free_extent_state(cached_state);
1796 *start = delalloc_start;
1797 *end = delalloc_end;
1802 static int __process_pages_contig(struct address_space *mapping,
1803 struct page *locked_page,
1804 pgoff_t start_index, pgoff_t end_index,
1805 unsigned long page_ops, pgoff_t *index_ret)
1807 unsigned long nr_pages = end_index - start_index + 1;
1808 unsigned long pages_locked = 0;
1809 pgoff_t index = start_index;
1810 struct page *pages[16];
1815 if (page_ops & PAGE_LOCK) {
1816 ASSERT(page_ops == PAGE_LOCK);
1817 ASSERT(index_ret && *index_ret == start_index);
1820 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1821 mapping_set_error(mapping, -EIO);
1823 while (nr_pages > 0) {
1824 ret = find_get_pages_contig(mapping, index,
1825 min_t(unsigned long,
1826 nr_pages, ARRAY_SIZE(pages)), pages);
1829 * Only if we're going to lock these pages,
1830 * can we find nothing at @index.
1832 ASSERT(page_ops & PAGE_LOCK);
1837 for (i = 0; i < ret; i++) {
1838 if (page_ops & PAGE_SET_PRIVATE2)
1839 SetPagePrivate2(pages[i]);
1841 if (pages[i] == locked_page) {
1846 if (page_ops & PAGE_CLEAR_DIRTY)
1847 clear_page_dirty_for_io(pages[i]);
1848 if (page_ops & PAGE_SET_WRITEBACK)
1849 set_page_writeback(pages[i]);
1850 if (page_ops & PAGE_SET_ERROR)
1851 SetPageError(pages[i]);
1852 if (page_ops & PAGE_END_WRITEBACK)
1853 end_page_writeback(pages[i]);
1854 if (page_ops & PAGE_UNLOCK)
1855 unlock_page(pages[i]);
1856 if (page_ops & PAGE_LOCK) {
1857 lock_page(pages[i]);
1858 if (!PageDirty(pages[i]) ||
1859 pages[i]->mapping != mapping) {
1860 unlock_page(pages[i]);
1874 if (err && index_ret)
1875 *index_ret = start_index + pages_locked - 1;
1879 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1880 u64 delalloc_end, struct page *locked_page,
1881 unsigned clear_bits,
1882 unsigned long page_ops)
1884 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0,
1887 __process_pages_contig(inode->i_mapping, locked_page,
1888 start >> PAGE_SHIFT, end >> PAGE_SHIFT,
1893 * count the number of bytes in the tree that have a given bit(s)
1894 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1895 * cached. The total number found is returned.
1897 u64 count_range_bits(struct extent_io_tree *tree,
1898 u64 *start, u64 search_end, u64 max_bytes,
1899 unsigned bits, int contig)
1901 struct rb_node *node;
1902 struct extent_state *state;
1903 u64 cur_start = *start;
1904 u64 total_bytes = 0;
1908 if (WARN_ON(search_end <= cur_start))
1911 spin_lock(&tree->lock);
1912 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1913 total_bytes = tree->dirty_bytes;
1917 * this search will find all the extents that end after
1920 node = tree_search(tree, cur_start);
1925 state = rb_entry(node, struct extent_state, rb_node);
1926 if (state->start > search_end)
1928 if (contig && found && state->start > last + 1)
1930 if (state->end >= cur_start && (state->state & bits) == bits) {
1931 total_bytes += min(search_end, state->end) + 1 -
1932 max(cur_start, state->start);
1933 if (total_bytes >= max_bytes)
1936 *start = max(cur_start, state->start);
1940 } else if (contig && found) {
1943 node = rb_next(node);
1948 spin_unlock(&tree->lock);
1953 * set the private field for a given byte offset in the tree. If there isn't
1954 * an extent_state there already, this does nothing.
1956 static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start,
1957 struct io_failure_record *failrec)
1959 struct rb_node *node;
1960 struct extent_state *state;
1963 spin_lock(&tree->lock);
1965 * this search will find all the extents that end after
1968 node = tree_search(tree, start);
1973 state = rb_entry(node, struct extent_state, rb_node);
1974 if (state->start != start) {
1978 state->failrec = failrec;
1980 spin_unlock(&tree->lock);
1984 static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start,
1985 struct io_failure_record **failrec)
1987 struct rb_node *node;
1988 struct extent_state *state;
1991 spin_lock(&tree->lock);
1993 * this search will find all the extents that end after
1996 node = tree_search(tree, start);
2001 state = rb_entry(node, struct extent_state, rb_node);
2002 if (state->start != start) {
2006 *failrec = state->failrec;
2008 spin_unlock(&tree->lock);
2013 * searches a range in the state tree for a given mask.
2014 * If 'filled' == 1, this returns 1 only if every extent in the tree
2015 * has the bits set. Otherwise, 1 is returned if any bit in the
2016 * range is found set.
2018 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
2019 unsigned bits, int filled, struct extent_state *cached)
2021 struct extent_state *state = NULL;
2022 struct rb_node *node;
2025 spin_lock(&tree->lock);
2026 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
2027 cached->end > start)
2028 node = &cached->rb_node;
2030 node = tree_search(tree, start);
2031 while (node && start <= end) {
2032 state = rb_entry(node, struct extent_state, rb_node);
2034 if (filled && state->start > start) {
2039 if (state->start > end)
2042 if (state->state & bits) {
2046 } else if (filled) {
2051 if (state->end == (u64)-1)
2054 start = state->end + 1;
2057 node = rb_next(node);
2064 spin_unlock(&tree->lock);
2069 * helper function to set a given page up to date if all the
2070 * extents in the tree for that page are up to date
2072 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
2074 u64 start = page_offset(page);
2075 u64 end = start + PAGE_SIZE - 1;
2076 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
2077 SetPageUptodate(page);
2080 int free_io_failure(struct extent_io_tree *failure_tree,
2081 struct extent_io_tree *io_tree,
2082 struct io_failure_record *rec)
2087 set_state_failrec(failure_tree, rec->start, NULL);
2088 ret = clear_extent_bits(failure_tree, rec->start,
2089 rec->start + rec->len - 1,
2090 EXTENT_LOCKED | EXTENT_DIRTY);
2094 ret = clear_extent_bits(io_tree, rec->start,
2095 rec->start + rec->len - 1,
2105 * this bypasses the standard btrfs submit functions deliberately, as
2106 * the standard behavior is to write all copies in a raid setup. here we only
2107 * want to write the one bad copy. so we do the mapping for ourselves and issue
2108 * submit_bio directly.
2109 * to avoid any synchronization issues, wait for the data after writing, which
2110 * actually prevents the read that triggered the error from finishing.
2111 * currently, there can be no more than two copies of every data bit. thus,
2112 * exactly one rewrite is required.
2114 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
2115 u64 length, u64 logical, struct page *page,
2116 unsigned int pg_offset, int mirror_num)
2119 struct btrfs_device *dev;
2122 struct btrfs_bio *bbio = NULL;
2125 ASSERT(!(fs_info->sb->s_flags & SB_RDONLY));
2126 BUG_ON(!mirror_num);
2128 bio = btrfs_io_bio_alloc(1);
2129 bio->bi_iter.bi_size = 0;
2130 map_length = length;
2133 * Avoid races with device replace and make sure our bbio has devices
2134 * associated to its stripes that don't go away while we are doing the
2135 * read repair operation.
2137 btrfs_bio_counter_inc_blocked(fs_info);
2138 if (btrfs_is_parity_mirror(fs_info, logical, length)) {
2140 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
2141 * to update all raid stripes, but here we just want to correct
2142 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
2143 * stripe's dev and sector.
2145 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical,
2146 &map_length, &bbio, 0);
2148 btrfs_bio_counter_dec(fs_info);
2152 ASSERT(bbio->mirror_num == 1);
2154 ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
2155 &map_length, &bbio, mirror_num);
2157 btrfs_bio_counter_dec(fs_info);
2161 BUG_ON(mirror_num != bbio->mirror_num);
2164 sector = bbio->stripes[bbio->mirror_num - 1].physical >> 9;
2165 bio->bi_iter.bi_sector = sector;
2166 dev = bbio->stripes[bbio->mirror_num - 1].dev;
2167 btrfs_put_bbio(bbio);
2168 if (!dev || !dev->bdev ||
2169 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
2170 btrfs_bio_counter_dec(fs_info);
2174 bio_set_dev(bio, dev->bdev);
2175 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
2176 bio_add_page(bio, page, length, pg_offset);
2178 if (btrfsic_submit_bio_wait(bio)) {
2179 /* try to remap that extent elsewhere? */
2180 btrfs_bio_counter_dec(fs_info);
2182 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2186 btrfs_info_rl_in_rcu(fs_info,
2187 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2189 rcu_str_deref(dev->name), sector);
2190 btrfs_bio_counter_dec(fs_info);
2195 int btrfs_repair_eb_io_failure(struct extent_buffer *eb, int mirror_num)
2197 struct btrfs_fs_info *fs_info = eb->fs_info;
2198 u64 start = eb->start;
2199 int i, num_pages = num_extent_pages(eb);
2202 if (sb_rdonly(fs_info->sb))
2205 for (i = 0; i < num_pages; i++) {
2206 struct page *p = eb->pages[i];
2208 ret = repair_io_failure(fs_info, 0, start, PAGE_SIZE, start, p,
2209 start - page_offset(p), mirror_num);
2219 * each time an IO finishes, we do a fast check in the IO failure tree
2220 * to see if we need to process or clean up an io_failure_record
2222 int clean_io_failure(struct btrfs_fs_info *fs_info,
2223 struct extent_io_tree *failure_tree,
2224 struct extent_io_tree *io_tree, u64 start,
2225 struct page *page, u64 ino, unsigned int pg_offset)
2228 struct io_failure_record *failrec;
2229 struct extent_state *state;
2234 ret = count_range_bits(failure_tree, &private, (u64)-1, 1,
2239 ret = get_state_failrec(failure_tree, start, &failrec);
2243 BUG_ON(!failrec->this_mirror);
2245 if (failrec->in_validation) {
2246 /* there was no real error, just free the record */
2247 btrfs_debug(fs_info,
2248 "clean_io_failure: freeing dummy error at %llu",
2252 if (sb_rdonly(fs_info->sb))
2255 spin_lock(&io_tree->lock);
2256 state = find_first_extent_bit_state(io_tree,
2259 spin_unlock(&io_tree->lock);
2261 if (state && state->start <= failrec->start &&
2262 state->end >= failrec->start + failrec->len - 1) {
2263 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2265 if (num_copies > 1) {
2266 repair_io_failure(fs_info, ino, start, failrec->len,
2267 failrec->logical, page, pg_offset,
2268 failrec->failed_mirror);
2273 free_io_failure(failure_tree, io_tree, failrec);
2279 * Can be called when
2280 * - hold extent lock
2281 * - under ordered extent
2282 * - the inode is freeing
2284 void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end)
2286 struct extent_io_tree *failure_tree = &inode->io_failure_tree;
2287 struct io_failure_record *failrec;
2288 struct extent_state *state, *next;
2290 if (RB_EMPTY_ROOT(&failure_tree->state))
2293 spin_lock(&failure_tree->lock);
2294 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2296 if (state->start > end)
2299 ASSERT(state->end <= end);
2301 next = next_state(state);
2303 failrec = state->failrec;
2304 free_extent_state(state);
2309 spin_unlock(&failure_tree->lock);
2312 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2313 struct io_failure_record **failrec_ret)
2315 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2316 struct io_failure_record *failrec;
2317 struct extent_map *em;
2318 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2319 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2320 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2324 ret = get_state_failrec(failure_tree, start, &failrec);
2326 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2330 failrec->start = start;
2331 failrec->len = end - start + 1;
2332 failrec->this_mirror = 0;
2333 failrec->bio_flags = 0;
2334 failrec->in_validation = 0;
2336 read_lock(&em_tree->lock);
2337 em = lookup_extent_mapping(em_tree, start, failrec->len);
2339 read_unlock(&em_tree->lock);
2344 if (em->start > start || em->start + em->len <= start) {
2345 free_extent_map(em);
2348 read_unlock(&em_tree->lock);
2354 logical = start - em->start;
2355 logical = em->block_start + logical;
2356 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2357 logical = em->block_start;
2358 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2359 extent_set_compress_type(&failrec->bio_flags,
2363 btrfs_debug(fs_info,
2364 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2365 logical, start, failrec->len);
2367 failrec->logical = logical;
2368 free_extent_map(em);
2370 /* set the bits in the private failure tree */
2371 ret = set_extent_bits(failure_tree, start, end,
2372 EXTENT_LOCKED | EXTENT_DIRTY);
2374 ret = set_state_failrec(failure_tree, start, failrec);
2375 /* set the bits in the inode's tree */
2377 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2383 btrfs_debug(fs_info,
2384 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2385 failrec->logical, failrec->start, failrec->len,
2386 failrec->in_validation);
2388 * when data can be on disk more than twice, add to failrec here
2389 * (e.g. with a list for failed_mirror) to make
2390 * clean_io_failure() clean all those errors at once.
2394 *failrec_ret = failrec;
2399 bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages,
2400 struct io_failure_record *failrec, int failed_mirror)
2402 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2405 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
2406 if (num_copies == 1) {
2408 * we only have a single copy of the data, so don't bother with
2409 * all the retry and error correction code that follows. no
2410 * matter what the error is, it is very likely to persist.
2412 btrfs_debug(fs_info,
2413 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2414 num_copies, failrec->this_mirror, failed_mirror);
2419 * there are two premises:
2420 * a) deliver good data to the caller
2421 * b) correct the bad sectors on disk
2423 if (failed_bio_pages > 1) {
2425 * to fulfill b), we need to know the exact failing sectors, as
2426 * we don't want to rewrite any more than the failed ones. thus,
2427 * we need separate read requests for the failed bio
2429 * if the following BUG_ON triggers, our validation request got
2430 * merged. we need separate requests for our algorithm to work.
2432 BUG_ON(failrec->in_validation);
2433 failrec->in_validation = 1;
2434 failrec->this_mirror = failed_mirror;
2437 * we're ready to fulfill a) and b) alongside. get a good copy
2438 * of the failed sector and if we succeed, we have setup
2439 * everything for repair_io_failure to do the rest for us.
2441 if (failrec->in_validation) {
2442 BUG_ON(failrec->this_mirror != failed_mirror);
2443 failrec->in_validation = 0;
2444 failrec->this_mirror = 0;
2446 failrec->failed_mirror = failed_mirror;
2447 failrec->this_mirror++;
2448 if (failrec->this_mirror == failed_mirror)
2449 failrec->this_mirror++;
2452 if (failrec->this_mirror > num_copies) {
2453 btrfs_debug(fs_info,
2454 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2455 num_copies, failrec->this_mirror, failed_mirror);
2463 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
2464 struct io_failure_record *failrec,
2465 struct page *page, int pg_offset, int icsum,
2466 bio_end_io_t *endio_func, void *data)
2468 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2470 struct btrfs_io_bio *btrfs_failed_bio;
2471 struct btrfs_io_bio *btrfs_bio;
2473 bio = btrfs_io_bio_alloc(1);
2474 bio->bi_end_io = endio_func;
2475 bio->bi_iter.bi_sector = failrec->logical >> 9;
2476 bio_set_dev(bio, fs_info->fs_devices->latest_bdev);
2477 bio->bi_iter.bi_size = 0;
2478 bio->bi_private = data;
2480 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2481 if (btrfs_failed_bio->csum) {
2482 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2484 btrfs_bio = btrfs_io_bio(bio);
2485 btrfs_bio->csum = btrfs_bio->csum_inline;
2487 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
2491 bio_add_page(bio, page, failrec->len, pg_offset);
2497 * This is a generic handler for readpage errors. If other copies exist, read
2498 * those and write back good data to the failed position. Does not investigate
2499 * in remapping the failed extent elsewhere, hoping the device will be smart
2500 * enough to do this as needed
2502 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2503 struct page *page, u64 start, u64 end,
2506 struct io_failure_record *failrec;
2507 struct inode *inode = page->mapping->host;
2508 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2509 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2512 blk_status_t status;
2514 unsigned failed_bio_pages = failed_bio->bi_iter.bi_size >> PAGE_SHIFT;
2516 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2518 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2522 if (!btrfs_check_repairable(inode, failed_bio_pages, failrec,
2524 free_io_failure(failure_tree, tree, failrec);
2528 if (failed_bio_pages > 1)
2529 read_mode |= REQ_FAILFAST_DEV;
2531 phy_offset >>= inode->i_sb->s_blocksize_bits;
2532 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
2533 start - page_offset(page),
2534 (int)phy_offset, failed_bio->bi_end_io,
2536 bio->bi_opf = REQ_OP_READ | read_mode;
2538 btrfs_debug(btrfs_sb(inode->i_sb),
2539 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2540 read_mode, failrec->this_mirror, failrec->in_validation);
2542 status = tree->ops->submit_bio_hook(tree->private_data, bio, failrec->this_mirror,
2543 failrec->bio_flags);
2545 free_io_failure(failure_tree, tree, failrec);
2547 ret = blk_status_to_errno(status);
2553 /* lots and lots of room for performance fixes in the end_bio funcs */
2555 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2557 int uptodate = (err == 0);
2560 btrfs_writepage_endio_finish_ordered(page, start, end, uptodate);
2563 ClearPageUptodate(page);
2565 ret = err < 0 ? err : -EIO;
2566 mapping_set_error(page->mapping, ret);
2571 * after a writepage IO is done, we need to:
2572 * clear the uptodate bits on error
2573 * clear the writeback bits in the extent tree for this IO
2574 * end_page_writeback if the page has no more pending IO
2576 * Scheduling is not allowed, so the extent state tree is expected
2577 * to have one and only one object corresponding to this IO.
2579 static void end_bio_extent_writepage(struct bio *bio)
2581 int error = blk_status_to_errno(bio->bi_status);
2582 struct bio_vec *bvec;
2585 struct bvec_iter_all iter_all;
2587 ASSERT(!bio_flagged(bio, BIO_CLONED));
2588 bio_for_each_segment_all(bvec, bio, iter_all) {
2589 struct page *page = bvec->bv_page;
2590 struct inode *inode = page->mapping->host;
2591 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2593 /* We always issue full-page reads, but if some block
2594 * in a page fails to read, blk_update_request() will
2595 * advance bv_offset and adjust bv_len to compensate.
2596 * Print a warning for nonzero offsets, and an error
2597 * if they don't add up to a full page. */
2598 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2599 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2601 "partial page write in btrfs with offset %u and length %u",
2602 bvec->bv_offset, bvec->bv_len);
2605 "incomplete page write in btrfs with offset %u and length %u",
2606 bvec->bv_offset, bvec->bv_len);
2609 start = page_offset(page);
2610 end = start + bvec->bv_offset + bvec->bv_len - 1;
2612 end_extent_writepage(page, error, start, end);
2613 end_page_writeback(page);
2620 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2623 struct extent_state *cached = NULL;
2624 u64 end = start + len - 1;
2626 if (uptodate && tree->track_uptodate)
2627 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2628 unlock_extent_cached_atomic(tree, start, end, &cached);
2632 * after a readpage IO is done, we need to:
2633 * clear the uptodate bits on error
2634 * set the uptodate bits if things worked
2635 * set the page up to date if all extents in the tree are uptodate
2636 * clear the lock bit in the extent tree
2637 * unlock the page if there are no other extents locked for it
2639 * Scheduling is not allowed, so the extent state tree is expected
2640 * to have one and only one object corresponding to this IO.
2642 static void end_bio_extent_readpage(struct bio *bio)
2644 struct bio_vec *bvec;
2645 int uptodate = !bio->bi_status;
2646 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2647 struct extent_io_tree *tree, *failure_tree;
2652 u64 extent_start = 0;
2656 struct bvec_iter_all iter_all;
2658 ASSERT(!bio_flagged(bio, BIO_CLONED));
2659 bio_for_each_segment_all(bvec, bio, iter_all) {
2660 struct page *page = bvec->bv_page;
2661 struct inode *inode = page->mapping->host;
2662 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2663 bool data_inode = btrfs_ino(BTRFS_I(inode))
2664 != BTRFS_BTREE_INODE_OBJECTID;
2666 btrfs_debug(fs_info,
2667 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2668 (u64)bio->bi_iter.bi_sector, bio->bi_status,
2669 io_bio->mirror_num);
2670 tree = &BTRFS_I(inode)->io_tree;
2671 failure_tree = &BTRFS_I(inode)->io_failure_tree;
2673 /* We always issue full-page reads, but if some block
2674 * in a page fails to read, blk_update_request() will
2675 * advance bv_offset and adjust bv_len to compensate.
2676 * Print a warning for nonzero offsets, and an error
2677 * if they don't add up to a full page. */
2678 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2679 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2681 "partial page read in btrfs with offset %u and length %u",
2682 bvec->bv_offset, bvec->bv_len);
2685 "incomplete page read in btrfs with offset %u and length %u",
2686 bvec->bv_offset, bvec->bv_len);
2689 start = page_offset(page);
2690 end = start + bvec->bv_offset + bvec->bv_len - 1;
2693 mirror = io_bio->mirror_num;
2694 if (likely(uptodate)) {
2695 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2701 clean_io_failure(BTRFS_I(inode)->root->fs_info,
2702 failure_tree, tree, start,
2704 btrfs_ino(BTRFS_I(inode)), 0);
2707 if (likely(uptodate))
2713 * The generic bio_readpage_error handles errors the
2714 * following way: If possible, new read requests are
2715 * created and submitted and will end up in
2716 * end_bio_extent_readpage as well (if we're lucky,
2717 * not in the !uptodate case). In that case it returns
2718 * 0 and we just go on with the next page in our bio.
2719 * If it can't handle the error it will return -EIO and
2720 * we remain responsible for that page.
2722 ret = bio_readpage_error(bio, offset, page, start, end,
2725 uptodate = !bio->bi_status;
2730 struct extent_buffer *eb;
2732 eb = (struct extent_buffer *)page->private;
2733 set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
2734 eb->read_mirror = mirror;
2735 atomic_dec(&eb->io_pages);
2736 if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD,
2738 btree_readahead_hook(eb, -EIO);
2741 if (likely(uptodate)) {
2742 loff_t i_size = i_size_read(inode);
2743 pgoff_t end_index = i_size >> PAGE_SHIFT;
2746 /* Zero out the end if this page straddles i_size */
2747 off = offset_in_page(i_size);
2748 if (page->index == end_index && off)
2749 zero_user_segment(page, off, PAGE_SIZE);
2750 SetPageUptodate(page);
2752 ClearPageUptodate(page);
2758 if (unlikely(!uptodate)) {
2760 endio_readpage_release_extent(tree,
2766 endio_readpage_release_extent(tree, start,
2767 end - start + 1, 0);
2768 } else if (!extent_len) {
2769 extent_start = start;
2770 extent_len = end + 1 - start;
2771 } else if (extent_start + extent_len == start) {
2772 extent_len += end + 1 - start;
2774 endio_readpage_release_extent(tree, extent_start,
2775 extent_len, uptodate);
2776 extent_start = start;
2777 extent_len = end + 1 - start;
2782 endio_readpage_release_extent(tree, extent_start, extent_len,
2784 btrfs_io_bio_free_csum(io_bio);
2789 * Initialize the members up to but not including 'bio'. Use after allocating a
2790 * new bio by bio_alloc_bioset as it does not initialize the bytes outside of
2791 * 'bio' because use of __GFP_ZERO is not supported.
2793 static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio)
2795 memset(btrfs_bio, 0, offsetof(struct btrfs_io_bio, bio));
2799 * The following helpers allocate a bio. As it's backed by a bioset, it'll
2800 * never fail. We're returning a bio right now but you can call btrfs_io_bio
2801 * for the appropriate container_of magic
2803 struct bio *btrfs_bio_alloc(struct block_device *bdev, u64 first_byte)
2807 bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, &btrfs_bioset);
2808 bio_set_dev(bio, bdev);
2809 bio->bi_iter.bi_sector = first_byte >> 9;
2810 btrfs_io_bio_init(btrfs_io_bio(bio));
2814 struct bio *btrfs_bio_clone(struct bio *bio)
2816 struct btrfs_io_bio *btrfs_bio;
2819 /* Bio allocation backed by a bioset does not fail */
2820 new = bio_clone_fast(bio, GFP_NOFS, &btrfs_bioset);
2821 btrfs_bio = btrfs_io_bio(new);
2822 btrfs_io_bio_init(btrfs_bio);
2823 btrfs_bio->iter = bio->bi_iter;
2827 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs)
2831 /* Bio allocation backed by a bioset does not fail */
2832 bio = bio_alloc_bioset(GFP_NOFS, nr_iovecs, &btrfs_bioset);
2833 btrfs_io_bio_init(btrfs_io_bio(bio));
2837 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
2840 struct btrfs_io_bio *btrfs_bio;
2842 /* this will never fail when it's backed by a bioset */
2843 bio = bio_clone_fast(orig, GFP_NOFS, &btrfs_bioset);
2846 btrfs_bio = btrfs_io_bio(bio);
2847 btrfs_io_bio_init(btrfs_bio);
2849 bio_trim(bio, offset >> 9, size >> 9);
2850 btrfs_bio->iter = bio->bi_iter;
2855 * @opf: bio REQ_OP_* and REQ_* flags as one value
2856 * @tree: tree so we can call our merge_bio hook
2857 * @wbc: optional writeback control for io accounting
2858 * @page: page to add to the bio
2859 * @pg_offset: offset of the new bio or to check whether we are adding
2860 * a contiguous page to the previous one
2861 * @size: portion of page that we want to write
2862 * @offset: starting offset in the page
2863 * @bdev: attach newly created bios to this bdev
2864 * @bio_ret: must be valid pointer, newly allocated bio will be stored there
2865 * @end_io_func: end_io callback for new bio
2866 * @mirror_num: desired mirror to read/write
2867 * @prev_bio_flags: flags of previous bio to see if we can merge the current one
2868 * @bio_flags: flags of the current bio to see if we can merge them
2870 static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
2871 struct writeback_control *wbc,
2872 struct page *page, u64 offset,
2873 size_t size, unsigned long pg_offset,
2874 struct block_device *bdev,
2875 struct bio **bio_ret,
2876 bio_end_io_t end_io_func,
2878 unsigned long prev_bio_flags,
2879 unsigned long bio_flags,
2880 bool force_bio_submit)
2884 size_t page_size = min_t(size_t, size, PAGE_SIZE);
2885 sector_t sector = offset >> 9;
2891 bool can_merge = true;
2894 if (prev_bio_flags & EXTENT_BIO_COMPRESSED)
2895 contig = bio->bi_iter.bi_sector == sector;
2897 contig = bio_end_sector(bio) == sector;
2900 if (btrfs_bio_fits_in_stripe(page, page_size, bio, bio_flags))
2903 if (prev_bio_flags != bio_flags || !contig || !can_merge ||
2905 bio_add_page(bio, page, page_size, pg_offset) < page_size) {
2906 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
2914 wbc_account_cgroup_owner(wbc, page, page_size);
2919 bio = btrfs_bio_alloc(bdev, offset);
2920 bio_add_page(bio, page, page_size, pg_offset);
2921 bio->bi_end_io = end_io_func;
2922 bio->bi_private = tree;
2923 bio->bi_write_hint = page->mapping->host->i_write_hint;
2926 wbc_init_bio(wbc, bio);
2927 wbc_account_cgroup_owner(wbc, page, page_size);
2935 static void attach_extent_buffer_page(struct extent_buffer *eb,
2938 if (!PagePrivate(page)) {
2939 SetPagePrivate(page);
2941 set_page_private(page, (unsigned long)eb);
2943 WARN_ON(page->private != (unsigned long)eb);
2947 void set_page_extent_mapped(struct page *page)
2949 if (!PagePrivate(page)) {
2950 SetPagePrivate(page);
2952 set_page_private(page, EXTENT_PAGE_PRIVATE);
2956 static struct extent_map *
2957 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
2958 u64 start, u64 len, get_extent_t *get_extent,
2959 struct extent_map **em_cached)
2961 struct extent_map *em;
2963 if (em_cached && *em_cached) {
2965 if (extent_map_in_tree(em) && start >= em->start &&
2966 start < extent_map_end(em)) {
2967 refcount_inc(&em->refs);
2971 free_extent_map(em);
2975 em = get_extent(BTRFS_I(inode), page, pg_offset, start, len, 0);
2976 if (em_cached && !IS_ERR_OR_NULL(em)) {
2978 refcount_inc(&em->refs);
2984 * basic readpage implementation. Locked extent state structs are inserted
2985 * into the tree that are removed when the IO is done (by the end_io
2987 * XXX JDM: This needs looking at to ensure proper page locking
2988 * return 0 on success, otherwise return error
2990 static int __do_readpage(struct extent_io_tree *tree,
2992 get_extent_t *get_extent,
2993 struct extent_map **em_cached,
2994 struct bio **bio, int mirror_num,
2995 unsigned long *bio_flags, unsigned int read_flags,
2998 struct inode *inode = page->mapping->host;
2999 u64 start = page_offset(page);
3000 const u64 end = start + PAGE_SIZE - 1;
3003 u64 last_byte = i_size_read(inode);
3006 struct extent_map *em;
3007 struct block_device *bdev;
3010 size_t pg_offset = 0;
3012 size_t disk_io_size;
3013 size_t blocksize = inode->i_sb->s_blocksize;
3014 unsigned long this_bio_flag = 0;
3016 set_page_extent_mapped(page);
3018 if (!PageUptodate(page)) {
3019 if (cleancache_get_page(page) == 0) {
3020 BUG_ON(blocksize != PAGE_SIZE);
3021 unlock_extent(tree, start, end);
3026 if (page->index == last_byte >> PAGE_SHIFT) {
3028 size_t zero_offset = offset_in_page(last_byte);
3031 iosize = PAGE_SIZE - zero_offset;
3032 userpage = kmap_atomic(page);
3033 memset(userpage + zero_offset, 0, iosize);
3034 flush_dcache_page(page);
3035 kunmap_atomic(userpage);
3038 while (cur <= end) {
3039 bool force_bio_submit = false;
3042 if (cur >= last_byte) {
3044 struct extent_state *cached = NULL;
3046 iosize = PAGE_SIZE - pg_offset;
3047 userpage = kmap_atomic(page);
3048 memset(userpage + pg_offset, 0, iosize);
3049 flush_dcache_page(page);
3050 kunmap_atomic(userpage);
3051 set_extent_uptodate(tree, cur, cur + iosize - 1,
3053 unlock_extent_cached(tree, cur,
3054 cur + iosize - 1, &cached);
3057 em = __get_extent_map(inode, page, pg_offset, cur,
3058 end - cur + 1, get_extent, em_cached);
3059 if (IS_ERR_OR_NULL(em)) {
3061 unlock_extent(tree, cur, end);
3064 extent_offset = cur - em->start;
3065 BUG_ON(extent_map_end(em) <= cur);
3068 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
3069 this_bio_flag |= EXTENT_BIO_COMPRESSED;
3070 extent_set_compress_type(&this_bio_flag,
3074 iosize = min(extent_map_end(em) - cur, end - cur + 1);
3075 cur_end = min(extent_map_end(em) - 1, end);
3076 iosize = ALIGN(iosize, blocksize);
3077 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
3078 disk_io_size = em->block_len;
3079 offset = em->block_start;
3081 offset = em->block_start + extent_offset;
3082 disk_io_size = iosize;
3085 block_start = em->block_start;
3086 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
3087 block_start = EXTENT_MAP_HOLE;
3090 * If we have a file range that points to a compressed extent
3091 * and it's followed by a consecutive file range that points to
3092 * to the same compressed extent (possibly with a different
3093 * offset and/or length, so it either points to the whole extent
3094 * or only part of it), we must make sure we do not submit a
3095 * single bio to populate the pages for the 2 ranges because
3096 * this makes the compressed extent read zero out the pages
3097 * belonging to the 2nd range. Imagine the following scenario:
3100 * [0 - 8K] [8K - 24K]
3103 * points to extent X, points to extent X,
3104 * offset 4K, length of 8K offset 0, length 16K
3106 * [extent X, compressed length = 4K uncompressed length = 16K]
3108 * If the bio to read the compressed extent covers both ranges,
3109 * it will decompress extent X into the pages belonging to the
3110 * first range and then it will stop, zeroing out the remaining
3111 * pages that belong to the other range that points to extent X.
3112 * So here we make sure we submit 2 bios, one for the first
3113 * range and another one for the third range. Both will target
3114 * the same physical extent from disk, but we can't currently
3115 * make the compressed bio endio callback populate the pages
3116 * for both ranges because each compressed bio is tightly
3117 * coupled with a single extent map, and each range can have
3118 * an extent map with a different offset value relative to the
3119 * uncompressed data of our extent and different lengths. This
3120 * is a corner case so we prioritize correctness over
3121 * non-optimal behavior (submitting 2 bios for the same extent).
3123 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3124 prev_em_start && *prev_em_start != (u64)-1 &&
3125 *prev_em_start != em->start)
3126 force_bio_submit = true;
3129 *prev_em_start = em->start;
3131 free_extent_map(em);
3134 /* we've found a hole, just zero and go on */
3135 if (block_start == EXTENT_MAP_HOLE) {
3137 struct extent_state *cached = NULL;
3139 userpage = kmap_atomic(page);
3140 memset(userpage + pg_offset, 0, iosize);
3141 flush_dcache_page(page);
3142 kunmap_atomic(userpage);
3144 set_extent_uptodate(tree, cur, cur + iosize - 1,
3146 unlock_extent_cached(tree, cur,
3147 cur + iosize - 1, &cached);
3149 pg_offset += iosize;
3152 /* the get_extent function already copied into the page */
3153 if (test_range_bit(tree, cur, cur_end,
3154 EXTENT_UPTODATE, 1, NULL)) {
3155 check_page_uptodate(tree, page);
3156 unlock_extent(tree, cur, cur + iosize - 1);
3158 pg_offset += iosize;
3161 /* we have an inline extent but it didn't get marked up
3162 * to date. Error out
3164 if (block_start == EXTENT_MAP_INLINE) {
3166 unlock_extent(tree, cur, cur + iosize - 1);
3168 pg_offset += iosize;
3172 ret = submit_extent_page(REQ_OP_READ | read_flags, tree, NULL,
3173 page, offset, disk_io_size,
3174 pg_offset, bdev, bio,
3175 end_bio_extent_readpage, mirror_num,
3181 *bio_flags = this_bio_flag;
3184 unlock_extent(tree, cur, cur + iosize - 1);
3188 pg_offset += iosize;
3192 if (!PageError(page))
3193 SetPageUptodate(page);
3199 static inline void contiguous_readpages(struct extent_io_tree *tree,
3200 struct page *pages[], int nr_pages,
3202 struct extent_map **em_cached,
3204 unsigned long *bio_flags,
3207 struct inode *inode;
3208 struct btrfs_ordered_extent *ordered;
3211 inode = pages[0]->mapping->host;
3213 lock_extent(tree, start, end);
3214 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
3218 unlock_extent(tree, start, end);
3219 btrfs_start_ordered_extent(inode, ordered, 1);
3220 btrfs_put_ordered_extent(ordered);
3223 for (index = 0; index < nr_pages; index++) {
3224 __do_readpage(tree, pages[index], btrfs_get_extent, em_cached,
3225 bio, 0, bio_flags, REQ_RAHEAD, prev_em_start);
3226 put_page(pages[index]);
3230 static int __extent_read_full_page(struct extent_io_tree *tree,
3232 get_extent_t *get_extent,
3233 struct bio **bio, int mirror_num,
3234 unsigned long *bio_flags,
3235 unsigned int read_flags)
3237 struct inode *inode = page->mapping->host;
3238 struct btrfs_ordered_extent *ordered;
3239 u64 start = page_offset(page);
3240 u64 end = start + PAGE_SIZE - 1;
3244 lock_extent(tree, start, end);
3245 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
3249 unlock_extent(tree, start, end);
3250 btrfs_start_ordered_extent(inode, ordered, 1);
3251 btrfs_put_ordered_extent(ordered);
3254 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3255 bio_flags, read_flags, NULL);
3259 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3260 get_extent_t *get_extent, int mirror_num)
3262 struct bio *bio = NULL;
3263 unsigned long bio_flags = 0;
3266 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3269 ret = submit_one_bio(bio, mirror_num, bio_flags);
3273 static void update_nr_written(struct writeback_control *wbc,
3274 unsigned long nr_written)
3276 wbc->nr_to_write -= nr_written;
3280 * helper for __extent_writepage, doing all of the delayed allocation setup.
3282 * This returns 1 if btrfs_run_delalloc_range function did all the work required
3283 * to write the page (copy into inline extent). In this case the IO has
3284 * been started and the page is already unlocked.
3286 * This returns 0 if all went well (page still locked)
3287 * This returns < 0 if there were errors (page still locked)
3289 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3290 struct page *page, struct writeback_control *wbc,
3291 u64 delalloc_start, unsigned long *nr_written)
3293 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
3294 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3296 u64 delalloc_to_write = 0;
3297 u64 delalloc_end = 0;
3299 int page_started = 0;
3302 while (delalloc_end < page_end) {
3303 found = find_lock_delalloc_range(inode, tree,
3308 delalloc_start = delalloc_end + 1;
3311 ret = btrfs_run_delalloc_range(inode, page, delalloc_start,
3312 delalloc_end, &page_started, nr_written, wbc);
3313 /* File system has been set read-only */
3317 * btrfs_run_delalloc_range should return < 0 for error
3318 * but just in case, we use > 0 here meaning the IO is
3319 * started, so we don't want to return > 0 unless
3320 * things are going well.
3322 ret = ret < 0 ? ret : -EIO;
3326 * delalloc_end is already one less than the total length, so
3327 * we don't subtract one from PAGE_SIZE
3329 delalloc_to_write += (delalloc_end - delalloc_start +
3330 PAGE_SIZE) >> PAGE_SHIFT;
3331 delalloc_start = delalloc_end + 1;
3333 if (wbc->nr_to_write < delalloc_to_write) {
3336 if (delalloc_to_write < thresh * 2)
3337 thresh = delalloc_to_write;
3338 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3342 /* did the fill delalloc function already unlock and start
3347 * we've unlocked the page, so we can't update
3348 * the mapping's writeback index, just update
3351 wbc->nr_to_write -= *nr_written;
3362 * helper for __extent_writepage. This calls the writepage start hooks,
3363 * and does the loop to map the page into extents and bios.
3365 * We return 1 if the IO is started and the page is unlocked,
3366 * 0 if all went well (page still locked)
3367 * < 0 if there were errors (page still locked)
3369 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3371 struct writeback_control *wbc,
3372 struct extent_page_data *epd,
3374 unsigned long nr_written,
3375 unsigned int write_flags, int *nr_ret)
3377 struct extent_io_tree *tree = epd->tree;
3378 u64 start = page_offset(page);
3379 u64 page_end = start + PAGE_SIZE - 1;
3385 struct extent_map *em;
3386 struct block_device *bdev;
3387 size_t pg_offset = 0;
3393 ret = btrfs_writepage_cow_fixup(page, start, page_end);
3395 /* Fixup worker will requeue */
3397 wbc->pages_skipped++;
3399 redirty_page_for_writepage(wbc, page);
3401 update_nr_written(wbc, nr_written);
3407 * we don't want to touch the inode after unlocking the page,
3408 * so we update the mapping writeback index now
3410 update_nr_written(wbc, nr_written + 1);
3413 if (i_size <= start) {
3414 btrfs_writepage_endio_finish_ordered(page, start, page_end, 1);
3418 blocksize = inode->i_sb->s_blocksize;
3420 while (cur <= end) {
3424 if (cur >= i_size) {
3425 btrfs_writepage_endio_finish_ordered(page, cur,
3429 em = btrfs_get_extent(BTRFS_I(inode), page, pg_offset, cur,
3431 if (IS_ERR_OR_NULL(em)) {
3433 ret = PTR_ERR_OR_ZERO(em);
3437 extent_offset = cur - em->start;
3438 em_end = extent_map_end(em);
3439 BUG_ON(em_end <= cur);
3441 iosize = min(em_end - cur, end - cur + 1);
3442 iosize = ALIGN(iosize, blocksize);
3443 offset = em->block_start + extent_offset;
3445 block_start = em->block_start;
3446 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3447 free_extent_map(em);
3451 * compressed and inline extents are written through other
3454 if (compressed || block_start == EXTENT_MAP_HOLE ||
3455 block_start == EXTENT_MAP_INLINE) {
3457 * end_io notification does not happen here for
3458 * compressed extents
3461 btrfs_writepage_endio_finish_ordered(page, cur,
3464 else if (compressed) {
3465 /* we don't want to end_page_writeback on
3466 * a compressed extent. this happens
3473 pg_offset += iosize;
3477 btrfs_set_range_writeback(tree, cur, cur + iosize - 1);
3478 if (!PageWriteback(page)) {
3479 btrfs_err(BTRFS_I(inode)->root->fs_info,
3480 "page %lu not writeback, cur %llu end %llu",
3481 page->index, cur, end);
3484 ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
3485 page, offset, iosize, pg_offset,
3487 end_bio_extent_writepage,
3491 if (PageWriteback(page))
3492 end_page_writeback(page);
3496 pg_offset += iosize;
3505 * the writepage semantics are similar to regular writepage. extent
3506 * records are inserted to lock ranges in the tree, and as dirty areas
3507 * are found, they are marked writeback. Then the lock bits are removed
3508 * and the end_io handler clears the writeback ranges
3510 * Return 0 if everything goes well.
3511 * Return <0 for error.
3513 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3514 struct extent_page_data *epd)
3516 struct inode *inode = page->mapping->host;
3517 u64 start = page_offset(page);
3518 u64 page_end = start + PAGE_SIZE - 1;
3521 size_t pg_offset = 0;
3522 loff_t i_size = i_size_read(inode);
3523 unsigned long end_index = i_size >> PAGE_SHIFT;
3524 unsigned int write_flags = 0;
3525 unsigned long nr_written = 0;
3527 write_flags = wbc_to_write_flags(wbc);
3529 trace___extent_writepage(page, inode, wbc);
3531 WARN_ON(!PageLocked(page));
3533 ClearPageError(page);
3535 pg_offset = offset_in_page(i_size);
3536 if (page->index > end_index ||
3537 (page->index == end_index && !pg_offset)) {
3538 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3543 if (page->index == end_index) {
3546 userpage = kmap_atomic(page);
3547 memset(userpage + pg_offset, 0,
3548 PAGE_SIZE - pg_offset);
3549 kunmap_atomic(userpage);
3550 flush_dcache_page(page);
3555 set_page_extent_mapped(page);
3557 if (!epd->extent_locked) {
3558 ret = writepage_delalloc(inode, page, wbc, start, &nr_written);
3565 ret = __extent_writepage_io(inode, page, wbc, epd,
3566 i_size, nr_written, write_flags, &nr);
3572 /* make sure the mapping tag for page dirty gets cleared */
3573 set_page_writeback(page);
3574 end_page_writeback(page);
3576 if (PageError(page)) {
3577 ret = ret < 0 ? ret : -EIO;
3578 end_extent_writepage(page, ret, start, page_end);
3588 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3590 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3591 TASK_UNINTERRUPTIBLE);
3595 * Lock eb pages and flush the bio if we can't the locks
3597 * Return 0 if nothing went wrong
3598 * Return >0 is same as 0, except bio is not submitted
3599 * Return <0 if something went wrong, no page is locked
3601 static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb,
3602 struct extent_page_data *epd)
3604 struct btrfs_fs_info *fs_info = eb->fs_info;
3605 int i, num_pages, failed_page_nr;
3609 if (!btrfs_try_tree_write_lock(eb)) {
3610 ret = flush_write_bio(epd);
3614 btrfs_tree_lock(eb);
3617 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3618 btrfs_tree_unlock(eb);
3622 ret = flush_write_bio(epd);
3628 wait_on_extent_buffer_writeback(eb);
3629 btrfs_tree_lock(eb);
3630 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3632 btrfs_tree_unlock(eb);
3637 * We need to do this to prevent races in people who check if the eb is
3638 * under IO since we can end up having no IO bits set for a short period
3641 spin_lock(&eb->refs_lock);
3642 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3643 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3644 spin_unlock(&eb->refs_lock);
3645 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3646 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
3648 fs_info->dirty_metadata_batch);
3651 spin_unlock(&eb->refs_lock);
3654 btrfs_tree_unlock(eb);
3659 num_pages = num_extent_pages(eb);
3660 for (i = 0; i < num_pages; i++) {
3661 struct page *p = eb->pages[i];
3663 if (!trylock_page(p)) {
3665 ret = flush_write_bio(epd);
3678 /* Unlock already locked pages */
3679 for (i = 0; i < failed_page_nr; i++)
3680 unlock_page(eb->pages[i]);
3684 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3686 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3687 smp_mb__after_atomic();
3688 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3691 static void set_btree_ioerr(struct page *page)
3693 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3696 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3700 * If writeback for a btree extent that doesn't belong to a log tree
3701 * failed, increment the counter transaction->eb_write_errors.
3702 * We do this because while the transaction is running and before it's
3703 * committing (when we call filemap_fdata[write|wait]_range against
3704 * the btree inode), we might have
3705 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3706 * returns an error or an error happens during writeback, when we're
3707 * committing the transaction we wouldn't know about it, since the pages
3708 * can be no longer dirty nor marked anymore for writeback (if a
3709 * subsequent modification to the extent buffer didn't happen before the
3710 * transaction commit), which makes filemap_fdata[write|wait]_range not
3711 * able to find the pages tagged with SetPageError at transaction
3712 * commit time. So if this happens we must abort the transaction,
3713 * otherwise we commit a super block with btree roots that point to
3714 * btree nodes/leafs whose content on disk is invalid - either garbage
3715 * or the content of some node/leaf from a past generation that got
3716 * cowed or deleted and is no longer valid.
3718 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3719 * not be enough - we need to distinguish between log tree extents vs
3720 * non-log tree extents, and the next filemap_fdatawait_range() call
3721 * will catch and clear such errors in the mapping - and that call might
3722 * be from a log sync and not from a transaction commit. Also, checking
3723 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3724 * not done and would not be reliable - the eb might have been released
3725 * from memory and reading it back again means that flag would not be
3726 * set (since it's a runtime flag, not persisted on disk).
3728 * Using the flags below in the btree inode also makes us achieve the
3729 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3730 * writeback for all dirty pages and before filemap_fdatawait_range()
3731 * is called, the writeback for all dirty pages had already finished
3732 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3733 * filemap_fdatawait_range() would return success, as it could not know
3734 * that writeback errors happened (the pages were no longer tagged for
3737 switch (eb->log_index) {
3739 set_bit(BTRFS_FS_BTREE_ERR, &eb->fs_info->flags);
3742 set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags);
3745 set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags);
3748 BUG(); /* unexpected, logic error */
3752 static void end_bio_extent_buffer_writepage(struct bio *bio)
3754 struct bio_vec *bvec;
3755 struct extent_buffer *eb;
3757 struct bvec_iter_all iter_all;
3759 ASSERT(!bio_flagged(bio, BIO_CLONED));
3760 bio_for_each_segment_all(bvec, bio, iter_all) {
3761 struct page *page = bvec->bv_page;
3763 eb = (struct extent_buffer *)page->private;
3765 done = atomic_dec_and_test(&eb->io_pages);
3767 if (bio->bi_status ||
3768 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3769 ClearPageUptodate(page);
3770 set_btree_ioerr(page);
3773 end_page_writeback(page);
3778 end_extent_buffer_writeback(eb);
3784 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3785 struct writeback_control *wbc,
3786 struct extent_page_data *epd)
3788 struct btrfs_fs_info *fs_info = eb->fs_info;
3789 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3790 struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
3791 u64 offset = eb->start;
3794 unsigned long start, end;
3795 unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META;
3798 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3799 num_pages = num_extent_pages(eb);
3800 atomic_set(&eb->io_pages, num_pages);
3802 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3803 nritems = btrfs_header_nritems(eb);
3804 if (btrfs_header_level(eb) > 0) {
3805 end = btrfs_node_key_ptr_offset(nritems);
3807 memzero_extent_buffer(eb, end, eb->len - end);
3811 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3813 start = btrfs_item_nr_offset(nritems);
3814 end = BTRFS_LEAF_DATA_OFFSET + leaf_data_end(eb);
3815 memzero_extent_buffer(eb, start, end - start);
3818 for (i = 0; i < num_pages; i++) {
3819 struct page *p = eb->pages[i];
3821 clear_page_dirty_for_io(p);
3822 set_page_writeback(p);
3823 ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
3824 p, offset, PAGE_SIZE, 0, bdev,
3826 end_bio_extent_buffer_writepage,
3830 if (PageWriteback(p))
3831 end_page_writeback(p);
3832 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3833 end_extent_buffer_writeback(eb);
3837 offset += PAGE_SIZE;
3838 update_nr_written(wbc, 1);
3842 if (unlikely(ret)) {
3843 for (; i < num_pages; i++) {
3844 struct page *p = eb->pages[i];
3845 clear_page_dirty_for_io(p);
3853 int btree_write_cache_pages(struct address_space *mapping,
3854 struct writeback_control *wbc)
3856 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3857 struct extent_buffer *eb, *prev_eb = NULL;
3858 struct extent_page_data epd = {
3862 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3866 int nr_to_write_done = 0;
3867 struct pagevec pvec;
3870 pgoff_t end; /* Inclusive */
3874 pagevec_init(&pvec);
3875 if (wbc->range_cyclic) {
3876 index = mapping->writeback_index; /* Start from prev offset */
3879 index = wbc->range_start >> PAGE_SHIFT;
3880 end = wbc->range_end >> PAGE_SHIFT;
3883 if (wbc->sync_mode == WB_SYNC_ALL)
3884 tag = PAGECACHE_TAG_TOWRITE;
3886 tag = PAGECACHE_TAG_DIRTY;
3888 if (wbc->sync_mode == WB_SYNC_ALL)
3889 tag_pages_for_writeback(mapping, index, end);
3890 while (!done && !nr_to_write_done && (index <= end) &&
3891 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
3896 for (i = 0; i < nr_pages; i++) {
3897 struct page *page = pvec.pages[i];
3899 if (!PagePrivate(page))
3902 spin_lock(&mapping->private_lock);
3903 if (!PagePrivate(page)) {
3904 spin_unlock(&mapping->private_lock);
3908 eb = (struct extent_buffer *)page->private;
3911 * Shouldn't happen and normally this would be a BUG_ON
3912 * but no sense in crashing the users box for something
3913 * we can survive anyway.
3916 spin_unlock(&mapping->private_lock);
3920 if (eb == prev_eb) {
3921 spin_unlock(&mapping->private_lock);
3925 ret = atomic_inc_not_zero(&eb->refs);
3926 spin_unlock(&mapping->private_lock);
3931 ret = lock_extent_buffer_for_io(eb, &epd);
3933 free_extent_buffer(eb);
3937 ret = write_one_eb(eb, wbc, &epd);
3940 free_extent_buffer(eb);
3943 free_extent_buffer(eb);
3946 * the filesystem may choose to bump up nr_to_write.
3947 * We have to make sure to honor the new nr_to_write
3950 nr_to_write_done = wbc->nr_to_write <= 0;
3952 pagevec_release(&pvec);
3955 if (!scanned && !done) {
3957 * We hit the last page and there is more work to be done: wrap
3958 * back to the start of the file
3966 end_write_bio(&epd, ret);
3969 ret = flush_write_bio(&epd);
3974 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3975 * @mapping: address space structure to write
3976 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3977 * @data: data passed to __extent_writepage function
3979 * If a page is already under I/O, write_cache_pages() skips it, even
3980 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3981 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3982 * and msync() need to guarantee that all the data which was dirty at the time
3983 * the call was made get new I/O started against them. If wbc->sync_mode is
3984 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3985 * existing IO to complete.
3987 static int extent_write_cache_pages(struct address_space *mapping,
3988 struct writeback_control *wbc,
3989 struct extent_page_data *epd)
3991 struct inode *inode = mapping->host;
3994 int nr_to_write_done = 0;
3995 struct pagevec pvec;
3998 pgoff_t end; /* Inclusive */
4000 int range_whole = 0;
4005 * We have to hold onto the inode so that ordered extents can do their
4006 * work when the IO finishes. The alternative to this is failing to add
4007 * an ordered extent if the igrab() fails there and that is a huge pain
4008 * to deal with, so instead just hold onto the inode throughout the
4009 * writepages operation. If it fails here we are freeing up the inode
4010 * anyway and we'd rather not waste our time writing out stuff that is
4011 * going to be truncated anyway.
4016 pagevec_init(&pvec);
4017 if (wbc->range_cyclic) {
4018 index = mapping->writeback_index; /* Start from prev offset */
4021 index = wbc->range_start >> PAGE_SHIFT;
4022 end = wbc->range_end >> PAGE_SHIFT;
4023 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
4029 * We do the tagged writepage as long as the snapshot flush bit is set
4030 * and we are the first one who do the filemap_flush() on this inode.
4032 * The nr_to_write == LONG_MAX is needed to make sure other flushers do
4033 * not race in and drop the bit.
4035 if (range_whole && wbc->nr_to_write == LONG_MAX &&
4036 test_and_clear_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
4037 &BTRFS_I(inode)->runtime_flags))
4038 wbc->tagged_writepages = 1;
4040 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
4041 tag = PAGECACHE_TAG_TOWRITE;
4043 tag = PAGECACHE_TAG_DIRTY;
4045 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
4046 tag_pages_for_writeback(mapping, index, end);
4048 while (!done && !nr_to_write_done && (index <= end) &&
4049 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping,
4050 &index, end, tag))) {
4054 for (i = 0; i < nr_pages; i++) {
4055 struct page *page = pvec.pages[i];
4057 done_index = page->index;
4059 * At this point we hold neither the i_pages lock nor
4060 * the page lock: the page may be truncated or
4061 * invalidated (changing page->mapping to NULL),
4062 * or even swizzled back from swapper_space to
4063 * tmpfs file mapping
4065 if (!trylock_page(page)) {
4066 ret = flush_write_bio(epd);
4071 if (unlikely(page->mapping != mapping)) {
4076 if (wbc->sync_mode != WB_SYNC_NONE) {
4077 if (PageWriteback(page)) {
4078 ret = flush_write_bio(epd);
4081 wait_on_page_writeback(page);
4084 if (PageWriteback(page) ||
4085 !clear_page_dirty_for_io(page)) {
4090 ret = __extent_writepage(page, wbc, epd);
4093 * done_index is set past this page,
4094 * so media errors will not choke
4095 * background writeout for the entire
4096 * file. This has consequences for
4097 * range_cyclic semantics (ie. it may
4098 * not be suitable for data integrity
4101 done_index = page->index + 1;
4107 * the filesystem may choose to bump up nr_to_write.
4108 * We have to make sure to honor the new nr_to_write
4111 nr_to_write_done = wbc->nr_to_write <= 0;
4113 pagevec_release(&pvec);
4116 if (!scanned && !done) {
4118 * We hit the last page and there is more work to be done: wrap
4119 * back to the start of the file
4126 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4127 mapping->writeback_index = done_index;
4129 btrfs_add_delayed_iput(inode);
4133 int extent_write_full_page(struct page *page, struct writeback_control *wbc)
4136 struct extent_page_data epd = {
4138 .tree = &BTRFS_I(page->mapping->host)->io_tree,
4140 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4143 ret = __extent_writepage(page, wbc, &epd);
4146 end_write_bio(&epd, ret);
4150 ret = flush_write_bio(&epd);
4155 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
4159 struct address_space *mapping = inode->i_mapping;
4160 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
4162 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4165 struct extent_page_data epd = {
4169 .sync_io = mode == WB_SYNC_ALL,
4171 struct writeback_control wbc_writepages = {
4173 .nr_to_write = nr_pages * 2,
4174 .range_start = start,
4175 .range_end = end + 1,
4178 while (start <= end) {
4179 page = find_get_page(mapping, start >> PAGE_SHIFT);
4180 if (clear_page_dirty_for_io(page))
4181 ret = __extent_writepage(page, &wbc_writepages, &epd);
4183 btrfs_writepage_endio_finish_ordered(page, start,
4184 start + PAGE_SIZE - 1, 1);
4193 end_write_bio(&epd, ret);
4196 ret = flush_write_bio(&epd);
4200 int extent_writepages(struct address_space *mapping,
4201 struct writeback_control *wbc)
4204 struct extent_page_data epd = {
4206 .tree = &BTRFS_I(mapping->host)->io_tree,
4208 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4211 ret = extent_write_cache_pages(mapping, wbc, &epd);
4214 end_write_bio(&epd, ret);
4217 ret = flush_write_bio(&epd);
4221 int extent_readpages(struct address_space *mapping, struct list_head *pages,
4224 struct bio *bio = NULL;
4225 unsigned long bio_flags = 0;
4226 struct page *pagepool[16];
4227 struct extent_map *em_cached = NULL;
4228 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
4230 u64 prev_em_start = (u64)-1;
4232 while (!list_empty(pages)) {
4235 for (nr = 0; nr < ARRAY_SIZE(pagepool) && !list_empty(pages);) {
4236 struct page *page = lru_to_page(pages);
4238 prefetchw(&page->flags);
4239 list_del(&page->lru);
4240 if (add_to_page_cache_lru(page, mapping, page->index,
4241 readahead_gfp_mask(mapping))) {
4246 pagepool[nr++] = page;
4247 contig_end = page_offset(page) + PAGE_SIZE - 1;
4251 u64 contig_start = page_offset(pagepool[0]);
4253 ASSERT(contig_start + nr * PAGE_SIZE - 1 == contig_end);
4255 contiguous_readpages(tree, pagepool, nr, contig_start,
4256 contig_end, &em_cached, &bio, &bio_flags,
4262 free_extent_map(em_cached);
4265 return submit_one_bio(bio, 0, bio_flags);
4270 * basic invalidatepage code, this waits on any locked or writeback
4271 * ranges corresponding to the page, and then deletes any extent state
4272 * records from the tree
4274 int extent_invalidatepage(struct extent_io_tree *tree,
4275 struct page *page, unsigned long offset)
4277 struct extent_state *cached_state = NULL;
4278 u64 start = page_offset(page);
4279 u64 end = start + PAGE_SIZE - 1;
4280 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4282 start += ALIGN(offset, blocksize);
4286 lock_extent_bits(tree, start, end, &cached_state);
4287 wait_on_page_writeback(page);
4288 clear_extent_bit(tree, start, end,
4289 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
4290 EXTENT_DO_ACCOUNTING,
4291 1, 1, &cached_state);
4296 * a helper for releasepage, this tests for areas of the page that
4297 * are locked or under IO and drops the related state bits if it is safe
4300 static int try_release_extent_state(struct extent_io_tree *tree,
4301 struct page *page, gfp_t mask)
4303 u64 start = page_offset(page);
4304 u64 end = start + PAGE_SIZE - 1;
4307 if (test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL)) {
4311 * at this point we can safely clear everything except the
4312 * locked bit and the nodatasum bit
4314 ret = __clear_extent_bit(tree, start, end,
4315 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4316 0, 0, NULL, mask, NULL);
4318 /* if clear_extent_bit failed for enomem reasons,
4319 * we can't allow the release to continue.
4330 * a helper for releasepage. As long as there are no locked extents
4331 * in the range corresponding to the page, both state records and extent
4332 * map records are removed
4334 int try_release_extent_mapping(struct page *page, gfp_t mask)
4336 struct extent_map *em;
4337 u64 start = page_offset(page);
4338 u64 end = start + PAGE_SIZE - 1;
4339 struct btrfs_inode *btrfs_inode = BTRFS_I(page->mapping->host);
4340 struct extent_io_tree *tree = &btrfs_inode->io_tree;
4341 struct extent_map_tree *map = &btrfs_inode->extent_tree;
4343 if (gfpflags_allow_blocking(mask) &&
4344 page->mapping->host->i_size > SZ_16M) {
4346 while (start <= end) {
4347 len = end - start + 1;
4348 write_lock(&map->lock);
4349 em = lookup_extent_mapping(map, start, len);
4351 write_unlock(&map->lock);
4354 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4355 em->start != start) {
4356 write_unlock(&map->lock);
4357 free_extent_map(em);
4360 if (!test_range_bit(tree, em->start,
4361 extent_map_end(em) - 1,
4362 EXTENT_LOCKED, 0, NULL)) {
4363 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4364 &btrfs_inode->runtime_flags);
4365 remove_extent_mapping(map, em);
4366 /* once for the rb tree */
4367 free_extent_map(em);
4369 start = extent_map_end(em);
4370 write_unlock(&map->lock);
4373 free_extent_map(em);
4376 return try_release_extent_state(tree, page, mask);
4380 * helper function for fiemap, which doesn't want to see any holes.
4381 * This maps until we find something past 'last'
4383 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4384 u64 offset, u64 last)
4386 u64 sectorsize = btrfs_inode_sectorsize(inode);
4387 struct extent_map *em;
4394 len = last - offset;
4397 len = ALIGN(len, sectorsize);
4398 em = btrfs_get_extent_fiemap(BTRFS_I(inode), offset, len);
4399 if (IS_ERR_OR_NULL(em))
4402 /* if this isn't a hole return it */
4403 if (em->block_start != EXTENT_MAP_HOLE)
4406 /* this is a hole, advance to the next extent */
4407 offset = extent_map_end(em);
4408 free_extent_map(em);
4416 * To cache previous fiemap extent
4418 * Will be used for merging fiemap extent
4420 struct fiemap_cache {
4429 * Helper to submit fiemap extent.
4431 * Will try to merge current fiemap extent specified by @offset, @phys,
4432 * @len and @flags with cached one.
4433 * And only when we fails to merge, cached one will be submitted as
4436 * Return value is the same as fiemap_fill_next_extent().
4438 static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
4439 struct fiemap_cache *cache,
4440 u64 offset, u64 phys, u64 len, u32 flags)
4448 * Sanity check, extent_fiemap() should have ensured that new
4449 * fiemap extent won't overlap with cached one.
4452 * NOTE: Physical address can overlap, due to compression
4454 if (cache->offset + cache->len > offset) {
4460 * Only merges fiemap extents if
4461 * 1) Their logical addresses are continuous
4463 * 2) Their physical addresses are continuous
4464 * So truly compressed (physical size smaller than logical size)
4465 * extents won't get merged with each other
4467 * 3) Share same flags except FIEMAP_EXTENT_LAST
4468 * So regular extent won't get merged with prealloc extent
4470 if (cache->offset + cache->len == offset &&
4471 cache->phys + cache->len == phys &&
4472 (cache->flags & ~FIEMAP_EXTENT_LAST) ==
4473 (flags & ~FIEMAP_EXTENT_LAST)) {
4475 cache->flags |= flags;
4476 goto try_submit_last;
4479 /* Not mergeable, need to submit cached one */
4480 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4481 cache->len, cache->flags);
4482 cache->cached = false;
4486 cache->cached = true;
4487 cache->offset = offset;
4490 cache->flags = flags;
4492 if (cache->flags & FIEMAP_EXTENT_LAST) {
4493 ret = fiemap_fill_next_extent(fieinfo, cache->offset,
4494 cache->phys, cache->len, cache->flags);
4495 cache->cached = false;
4501 * Emit last fiemap cache
4503 * The last fiemap cache may still be cached in the following case:
4505 * |<- Fiemap range ->|
4506 * |<------------ First extent ----------->|
4508 * In this case, the first extent range will be cached but not emitted.
4509 * So we must emit it before ending extent_fiemap().
4511 static int emit_last_fiemap_cache(struct fiemap_extent_info *fieinfo,
4512 struct fiemap_cache *cache)
4519 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4520 cache->len, cache->flags);
4521 cache->cached = false;
4527 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4528 __u64 start, __u64 len)
4532 u64 max = start + len;
4536 u64 last_for_get_extent = 0;
4538 u64 isize = i_size_read(inode);
4539 struct btrfs_key found_key;
4540 struct extent_map *em = NULL;
4541 struct extent_state *cached_state = NULL;
4542 struct btrfs_path *path;
4543 struct btrfs_root *root = BTRFS_I(inode)->root;
4544 struct fiemap_cache cache = { 0 };
4553 path = btrfs_alloc_path();
4556 path->leave_spinning = 1;
4558 start = round_down(start, btrfs_inode_sectorsize(inode));
4559 len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
4562 * lookup the last file extent. We're not using i_size here
4563 * because there might be preallocation past i_size
4565 ret = btrfs_lookup_file_extent(NULL, root, path,
4566 btrfs_ino(BTRFS_I(inode)), -1, 0);
4568 btrfs_free_path(path);
4577 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4578 found_type = found_key.type;
4580 /* No extents, but there might be delalloc bits */
4581 if (found_key.objectid != btrfs_ino(BTRFS_I(inode)) ||
4582 found_type != BTRFS_EXTENT_DATA_KEY) {
4583 /* have to trust i_size as the end */
4585 last_for_get_extent = isize;
4588 * remember the start of the last extent. There are a
4589 * bunch of different factors that go into the length of the
4590 * extent, so its much less complex to remember where it started
4592 last = found_key.offset;
4593 last_for_get_extent = last + 1;
4595 btrfs_release_path(path);
4598 * we might have some extents allocated but more delalloc past those
4599 * extents. so, we trust isize unless the start of the last extent is
4604 last_for_get_extent = isize;
4607 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4610 em = get_extent_skip_holes(inode, start, last_for_get_extent);
4619 u64 offset_in_extent = 0;
4621 /* break if the extent we found is outside the range */
4622 if (em->start >= max || extent_map_end(em) < off)
4626 * get_extent may return an extent that starts before our
4627 * requested range. We have to make sure the ranges
4628 * we return to fiemap always move forward and don't
4629 * overlap, so adjust the offsets here
4631 em_start = max(em->start, off);
4634 * record the offset from the start of the extent
4635 * for adjusting the disk offset below. Only do this if the
4636 * extent isn't compressed since our in ram offset may be past
4637 * what we have actually allocated on disk.
4639 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4640 offset_in_extent = em_start - em->start;
4641 em_end = extent_map_end(em);
4642 em_len = em_end - em_start;
4644 if (em->block_start < EXTENT_MAP_LAST_BYTE)
4645 disko = em->block_start + offset_in_extent;
4650 * bump off for our next call to get_extent
4652 off = extent_map_end(em);
4656 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4658 flags |= FIEMAP_EXTENT_LAST;
4659 } else if (em->block_start == EXTENT_MAP_INLINE) {
4660 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4661 FIEMAP_EXTENT_NOT_ALIGNED);
4662 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4663 flags |= (FIEMAP_EXTENT_DELALLOC |
4664 FIEMAP_EXTENT_UNKNOWN);
4665 } else if (fieinfo->fi_extents_max) {
4666 u64 bytenr = em->block_start -
4667 (em->start - em->orig_start);
4670 * As btrfs supports shared space, this information
4671 * can be exported to userspace tools via
4672 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4673 * then we're just getting a count and we can skip the
4676 ret = btrfs_check_shared(root,
4677 btrfs_ino(BTRFS_I(inode)),
4682 flags |= FIEMAP_EXTENT_SHARED;
4685 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4686 flags |= FIEMAP_EXTENT_ENCODED;
4687 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4688 flags |= FIEMAP_EXTENT_UNWRITTEN;
4690 free_extent_map(em);
4692 if ((em_start >= last) || em_len == (u64)-1 ||
4693 (last == (u64)-1 && isize <= em_end)) {
4694 flags |= FIEMAP_EXTENT_LAST;
4698 /* now scan forward to see if this is really the last extent. */
4699 em = get_extent_skip_holes(inode, off, last_for_get_extent);
4705 flags |= FIEMAP_EXTENT_LAST;
4708 ret = emit_fiemap_extent(fieinfo, &cache, em_start, disko,
4718 ret = emit_last_fiemap_cache(fieinfo, &cache);
4719 free_extent_map(em);
4721 btrfs_free_path(path);
4722 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4727 static void __free_extent_buffer(struct extent_buffer *eb)
4729 btrfs_leak_debug_del(&eb->leak_list);
4730 kmem_cache_free(extent_buffer_cache, eb);
4733 int extent_buffer_under_io(struct extent_buffer *eb)
4735 return (atomic_read(&eb->io_pages) ||
4736 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4737 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4741 * Release all pages attached to the extent buffer.
4743 static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb)
4747 int mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
4749 BUG_ON(extent_buffer_under_io(eb));
4751 num_pages = num_extent_pages(eb);
4752 for (i = 0; i < num_pages; i++) {
4753 struct page *page = eb->pages[i];
4758 spin_lock(&page->mapping->private_lock);
4760 * We do this since we'll remove the pages after we've
4761 * removed the eb from the radix tree, so we could race
4762 * and have this page now attached to the new eb. So
4763 * only clear page_private if it's still connected to
4766 if (PagePrivate(page) &&
4767 page->private == (unsigned long)eb) {
4768 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4769 BUG_ON(PageDirty(page));
4770 BUG_ON(PageWriteback(page));
4772 * We need to make sure we haven't be attached
4775 ClearPagePrivate(page);
4776 set_page_private(page, 0);
4777 /* One for the page private */
4782 spin_unlock(&page->mapping->private_lock);
4784 /* One for when we allocated the page */
4790 * Helper for releasing the extent buffer.
4792 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4794 btrfs_release_extent_buffer_pages(eb);
4795 __free_extent_buffer(eb);
4798 static struct extent_buffer *
4799 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4802 struct extent_buffer *eb = NULL;
4804 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4807 eb->fs_info = fs_info;
4809 rwlock_init(&eb->lock);
4810 atomic_set(&eb->blocking_readers, 0);
4811 atomic_set(&eb->blocking_writers, 0);
4812 eb->lock_nested = false;
4813 init_waitqueue_head(&eb->write_lock_wq);
4814 init_waitqueue_head(&eb->read_lock_wq);
4816 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4818 spin_lock_init(&eb->refs_lock);
4819 atomic_set(&eb->refs, 1);
4820 atomic_set(&eb->io_pages, 0);
4823 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4825 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4826 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4827 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4829 #ifdef CONFIG_BTRFS_DEBUG
4830 atomic_set(&eb->spinning_writers, 0);
4831 atomic_set(&eb->spinning_readers, 0);
4832 atomic_set(&eb->read_locks, 0);
4833 atomic_set(&eb->write_locks, 0);
4839 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4843 struct extent_buffer *new;
4844 int num_pages = num_extent_pages(src);
4846 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
4850 for (i = 0; i < num_pages; i++) {
4851 p = alloc_page(GFP_NOFS);
4853 btrfs_release_extent_buffer(new);
4856 attach_extent_buffer_page(new, p);
4857 WARN_ON(PageDirty(p));
4860 copy_page(page_address(p), page_address(src->pages[i]));
4863 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4864 set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags);
4869 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4870 u64 start, unsigned long len)
4872 struct extent_buffer *eb;
4876 eb = __alloc_extent_buffer(fs_info, start, len);
4880 num_pages = num_extent_pages(eb);
4881 for (i = 0; i < num_pages; i++) {
4882 eb->pages[i] = alloc_page(GFP_NOFS);
4886 set_extent_buffer_uptodate(eb);
4887 btrfs_set_header_nritems(eb, 0);
4888 set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
4893 __free_page(eb->pages[i - 1]);
4894 __free_extent_buffer(eb);
4898 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4901 return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
4904 static void check_buffer_tree_ref(struct extent_buffer *eb)
4907 /* the ref bit is tricky. We have to make sure it is set
4908 * if we have the buffer dirty. Otherwise the
4909 * code to free a buffer can end up dropping a dirty
4912 * Once the ref bit is set, it won't go away while the
4913 * buffer is dirty or in writeback, and it also won't
4914 * go away while we have the reference count on the
4917 * We can't just set the ref bit without bumping the
4918 * ref on the eb because free_extent_buffer might
4919 * see the ref bit and try to clear it. If this happens
4920 * free_extent_buffer might end up dropping our original
4921 * ref by mistake and freeing the page before we are able
4922 * to add one more ref.
4924 * So bump the ref count first, then set the bit. If someone
4925 * beat us to it, drop the ref we added.
4927 refs = atomic_read(&eb->refs);
4928 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4931 spin_lock(&eb->refs_lock);
4932 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4933 atomic_inc(&eb->refs);
4934 spin_unlock(&eb->refs_lock);
4937 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
4938 struct page *accessed)
4942 check_buffer_tree_ref(eb);
4944 num_pages = num_extent_pages(eb);
4945 for (i = 0; i < num_pages; i++) {
4946 struct page *p = eb->pages[i];
4949 mark_page_accessed(p);
4953 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
4956 struct extent_buffer *eb;
4959 eb = radix_tree_lookup(&fs_info->buffer_radix,
4960 start >> PAGE_SHIFT);
4961 if (eb && atomic_inc_not_zero(&eb->refs)) {
4964 * Lock our eb's refs_lock to avoid races with
4965 * free_extent_buffer. When we get our eb it might be flagged
4966 * with EXTENT_BUFFER_STALE and another task running
4967 * free_extent_buffer might have seen that flag set,
4968 * eb->refs == 2, that the buffer isn't under IO (dirty and
4969 * writeback flags not set) and it's still in the tree (flag
4970 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4971 * of decrementing the extent buffer's reference count twice.
4972 * So here we could race and increment the eb's reference count,
4973 * clear its stale flag, mark it as dirty and drop our reference
4974 * before the other task finishes executing free_extent_buffer,
4975 * which would later result in an attempt to free an extent
4976 * buffer that is dirty.
4978 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
4979 spin_lock(&eb->refs_lock);
4980 spin_unlock(&eb->refs_lock);
4982 mark_extent_buffer_accessed(eb, NULL);
4990 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4991 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
4994 struct extent_buffer *eb, *exists = NULL;
4997 eb = find_extent_buffer(fs_info, start);
5000 eb = alloc_dummy_extent_buffer(fs_info, start);
5003 eb->fs_info = fs_info;
5005 ret = radix_tree_preload(GFP_NOFS);
5008 spin_lock(&fs_info->buffer_lock);
5009 ret = radix_tree_insert(&fs_info->buffer_radix,
5010 start >> PAGE_SHIFT, eb);
5011 spin_unlock(&fs_info->buffer_lock);
5012 radix_tree_preload_end();
5013 if (ret == -EEXIST) {
5014 exists = find_extent_buffer(fs_info, start);
5020 check_buffer_tree_ref(eb);
5021 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5025 btrfs_release_extent_buffer(eb);
5030 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
5033 unsigned long len = fs_info->nodesize;
5036 unsigned long index = start >> PAGE_SHIFT;
5037 struct extent_buffer *eb;
5038 struct extent_buffer *exists = NULL;
5040 struct address_space *mapping = fs_info->btree_inode->i_mapping;
5044 if (!IS_ALIGNED(start, fs_info->sectorsize)) {
5045 btrfs_err(fs_info, "bad tree block start %llu", start);
5046 return ERR_PTR(-EINVAL);
5049 eb = find_extent_buffer(fs_info, start);
5053 eb = __alloc_extent_buffer(fs_info, start, len);
5055 return ERR_PTR(-ENOMEM);
5057 num_pages = num_extent_pages(eb);
5058 for (i = 0; i < num_pages; i++, index++) {
5059 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
5061 exists = ERR_PTR(-ENOMEM);
5065 spin_lock(&mapping->private_lock);
5066 if (PagePrivate(p)) {
5068 * We could have already allocated an eb for this page
5069 * and attached one so lets see if we can get a ref on
5070 * the existing eb, and if we can we know it's good and
5071 * we can just return that one, else we know we can just
5072 * overwrite page->private.
5074 exists = (struct extent_buffer *)p->private;
5075 if (atomic_inc_not_zero(&exists->refs)) {
5076 spin_unlock(&mapping->private_lock);
5079 mark_extent_buffer_accessed(exists, p);
5085 * Do this so attach doesn't complain and we need to
5086 * drop the ref the old guy had.
5088 ClearPagePrivate(p);
5089 WARN_ON(PageDirty(p));
5092 attach_extent_buffer_page(eb, p);
5093 spin_unlock(&mapping->private_lock);
5094 WARN_ON(PageDirty(p));
5096 if (!PageUptodate(p))
5100 * We can't unlock the pages just yet since the extent buffer
5101 * hasn't been properly inserted in the radix tree, this
5102 * opens a race with btree_releasepage which can free a page
5103 * while we are still filling in all pages for the buffer and
5108 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5110 ret = radix_tree_preload(GFP_NOFS);
5112 exists = ERR_PTR(ret);
5116 spin_lock(&fs_info->buffer_lock);
5117 ret = radix_tree_insert(&fs_info->buffer_radix,
5118 start >> PAGE_SHIFT, eb);
5119 spin_unlock(&fs_info->buffer_lock);
5120 radix_tree_preload_end();
5121 if (ret == -EEXIST) {
5122 exists = find_extent_buffer(fs_info, start);
5128 /* add one reference for the tree */
5129 check_buffer_tree_ref(eb);
5130 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5133 * Now it's safe to unlock the pages because any calls to
5134 * btree_releasepage will correctly detect that a page belongs to a
5135 * live buffer and won't free them prematurely.
5137 for (i = 0; i < num_pages; i++)
5138 unlock_page(eb->pages[i]);
5142 WARN_ON(!atomic_dec_and_test(&eb->refs));
5143 for (i = 0; i < num_pages; i++) {
5145 unlock_page(eb->pages[i]);
5148 btrfs_release_extent_buffer(eb);
5152 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5154 struct extent_buffer *eb =
5155 container_of(head, struct extent_buffer, rcu_head);
5157 __free_extent_buffer(eb);
5160 static int release_extent_buffer(struct extent_buffer *eb)
5162 lockdep_assert_held(&eb->refs_lock);
5164 WARN_ON(atomic_read(&eb->refs) == 0);
5165 if (atomic_dec_and_test(&eb->refs)) {
5166 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5167 struct btrfs_fs_info *fs_info = eb->fs_info;
5169 spin_unlock(&eb->refs_lock);
5171 spin_lock(&fs_info->buffer_lock);
5172 radix_tree_delete(&fs_info->buffer_radix,
5173 eb->start >> PAGE_SHIFT);
5174 spin_unlock(&fs_info->buffer_lock);
5176 spin_unlock(&eb->refs_lock);
5179 /* Should be safe to release our pages at this point */
5180 btrfs_release_extent_buffer_pages(eb);
5181 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5182 if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))) {
5183 __free_extent_buffer(eb);
5187 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5190 spin_unlock(&eb->refs_lock);
5195 void free_extent_buffer(struct extent_buffer *eb)
5203 refs = atomic_read(&eb->refs);
5204 if ((!test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) && refs <= 3)
5205 || (test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) &&
5208 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5213 spin_lock(&eb->refs_lock);
5214 if (atomic_read(&eb->refs) == 2 &&
5215 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5216 !extent_buffer_under_io(eb) &&
5217 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5218 atomic_dec(&eb->refs);
5221 * I know this is terrible, but it's temporary until we stop tracking
5222 * the uptodate bits and such for the extent buffers.
5224 release_extent_buffer(eb);
5227 void free_extent_buffer_stale(struct extent_buffer *eb)
5232 spin_lock(&eb->refs_lock);
5233 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5235 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5236 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5237 atomic_dec(&eb->refs);
5238 release_extent_buffer(eb);
5241 void clear_extent_buffer_dirty(struct extent_buffer *eb)
5247 num_pages = num_extent_pages(eb);
5249 for (i = 0; i < num_pages; i++) {
5250 page = eb->pages[i];
5251 if (!PageDirty(page))
5255 WARN_ON(!PagePrivate(page));
5257 clear_page_dirty_for_io(page);
5258 xa_lock_irq(&page->mapping->i_pages);
5259 if (!PageDirty(page))
5260 __xa_clear_mark(&page->mapping->i_pages,
5261 page_index(page), PAGECACHE_TAG_DIRTY);
5262 xa_unlock_irq(&page->mapping->i_pages);
5263 ClearPageError(page);
5266 WARN_ON(atomic_read(&eb->refs) == 0);
5269 bool set_extent_buffer_dirty(struct extent_buffer *eb)
5275 check_buffer_tree_ref(eb);
5277 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5279 num_pages = num_extent_pages(eb);
5280 WARN_ON(atomic_read(&eb->refs) == 0);
5281 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5284 for (i = 0; i < num_pages; i++)
5285 set_page_dirty(eb->pages[i]);
5287 #ifdef CONFIG_BTRFS_DEBUG
5288 for (i = 0; i < num_pages; i++)
5289 ASSERT(PageDirty(eb->pages[i]));
5295 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5301 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5302 num_pages = num_extent_pages(eb);
5303 for (i = 0; i < num_pages; i++) {
5304 page = eb->pages[i];
5306 ClearPageUptodate(page);
5310 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5316 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5317 num_pages = num_extent_pages(eb);
5318 for (i = 0; i < num_pages; i++) {
5319 page = eb->pages[i];
5320 SetPageUptodate(page);
5324 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num)
5330 int locked_pages = 0;
5331 int all_uptodate = 1;
5333 unsigned long num_reads = 0;
5334 struct bio *bio = NULL;
5335 unsigned long bio_flags = 0;
5336 struct extent_io_tree *tree = &BTRFS_I(eb->fs_info->btree_inode)->io_tree;
5338 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5341 num_pages = num_extent_pages(eb);
5342 for (i = 0; i < num_pages; i++) {
5343 page = eb->pages[i];
5344 if (wait == WAIT_NONE) {
5345 if (!trylock_page(page))
5353 * We need to firstly lock all pages to make sure that
5354 * the uptodate bit of our pages won't be affected by
5355 * clear_extent_buffer_uptodate().
5357 for (i = 0; i < num_pages; i++) {
5358 page = eb->pages[i];
5359 if (!PageUptodate(page)) {
5366 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5370 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5371 eb->read_mirror = 0;
5372 atomic_set(&eb->io_pages, num_reads);
5373 for (i = 0; i < num_pages; i++) {
5374 page = eb->pages[i];
5376 if (!PageUptodate(page)) {
5378 atomic_dec(&eb->io_pages);
5383 ClearPageError(page);
5384 err = __extent_read_full_page(tree, page,
5385 btree_get_extent, &bio,
5386 mirror_num, &bio_flags,
5391 * We use &bio in above __extent_read_full_page,
5392 * so we ensure that if it returns error, the
5393 * current page fails to add itself to bio and
5394 * it's been unlocked.
5396 * We must dec io_pages by ourselves.
5398 atomic_dec(&eb->io_pages);
5406 err = submit_one_bio(bio, mirror_num, bio_flags);
5411 if (ret || wait != WAIT_COMPLETE)
5414 for (i = 0; i < num_pages; i++) {
5415 page = eb->pages[i];
5416 wait_on_page_locked(page);
5417 if (!PageUptodate(page))
5424 while (locked_pages > 0) {
5426 page = eb->pages[locked_pages];
5432 void read_extent_buffer(const struct extent_buffer *eb, void *dstv,
5433 unsigned long start, unsigned long len)
5439 char *dst = (char *)dstv;
5440 size_t start_offset = offset_in_page(eb->start);
5441 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5443 if (start + len > eb->len) {
5444 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5445 eb->start, eb->len, start, len);
5446 memset(dst, 0, len);
5450 offset = offset_in_page(start_offset + start);
5453 page = eb->pages[i];
5455 cur = min(len, (PAGE_SIZE - offset));
5456 kaddr = page_address(page);
5457 memcpy(dst, kaddr + offset, cur);
5466 int read_extent_buffer_to_user(const struct extent_buffer *eb,
5468 unsigned long start, unsigned long len)
5474 char __user *dst = (char __user *)dstv;
5475 size_t start_offset = offset_in_page(eb->start);
5476 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5479 WARN_ON(start > eb->len);
5480 WARN_ON(start + len > eb->start + eb->len);
5482 offset = offset_in_page(start_offset + start);
5485 page = eb->pages[i];
5487 cur = min(len, (PAGE_SIZE - offset));
5488 kaddr = page_address(page);
5489 if (copy_to_user(dst, kaddr + offset, cur)) {
5504 * return 0 if the item is found within a page.
5505 * return 1 if the item spans two pages.
5506 * return -EINVAL otherwise.
5508 int map_private_extent_buffer(const struct extent_buffer *eb,
5509 unsigned long start, unsigned long min_len,
5510 char **map, unsigned long *map_start,
5511 unsigned long *map_len)
5516 size_t start_offset = offset_in_page(eb->start);
5517 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5518 unsigned long end_i = (start_offset + start + min_len - 1) >>
5521 if (start + min_len > eb->len) {
5522 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5523 eb->start, eb->len, start, min_len);
5531 offset = start_offset;
5535 *map_start = ((u64)i << PAGE_SHIFT) - start_offset;
5539 kaddr = page_address(p);
5540 *map = kaddr + offset;
5541 *map_len = PAGE_SIZE - offset;
5545 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
5546 unsigned long start, unsigned long len)
5552 char *ptr = (char *)ptrv;
5553 size_t start_offset = offset_in_page(eb->start);
5554 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5557 WARN_ON(start > eb->len);
5558 WARN_ON(start + len > eb->start + eb->len);
5560 offset = offset_in_page(start_offset + start);
5563 page = eb->pages[i];
5565 cur = min(len, (PAGE_SIZE - offset));
5567 kaddr = page_address(page);
5568 ret = memcmp(ptr, kaddr + offset, cur);
5580 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
5585 WARN_ON(!PageUptodate(eb->pages[0]));
5586 kaddr = page_address(eb->pages[0]);
5587 memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
5591 void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)
5595 WARN_ON(!PageUptodate(eb->pages[0]));
5596 kaddr = page_address(eb->pages[0]);
5597 memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
5601 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
5602 unsigned long start, unsigned long len)
5608 char *src = (char *)srcv;
5609 size_t start_offset = offset_in_page(eb->start);
5610 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5612 WARN_ON(start > eb->len);
5613 WARN_ON(start + len > eb->start + eb->len);
5615 offset = offset_in_page(start_offset + start);
5618 page = eb->pages[i];
5619 WARN_ON(!PageUptodate(page));
5621 cur = min(len, PAGE_SIZE - offset);
5622 kaddr = page_address(page);
5623 memcpy(kaddr + offset, src, cur);
5632 void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
5639 size_t start_offset = offset_in_page(eb->start);
5640 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5642 WARN_ON(start > eb->len);
5643 WARN_ON(start + len > eb->start + eb->len);
5645 offset = offset_in_page(start_offset + start);
5648 page = eb->pages[i];
5649 WARN_ON(!PageUptodate(page));
5651 cur = min(len, PAGE_SIZE - offset);
5652 kaddr = page_address(page);
5653 memset(kaddr + offset, 0, cur);
5661 void copy_extent_buffer_full(struct extent_buffer *dst,
5662 struct extent_buffer *src)
5667 ASSERT(dst->len == src->len);
5669 num_pages = num_extent_pages(dst);
5670 for (i = 0; i < num_pages; i++)
5671 copy_page(page_address(dst->pages[i]),
5672 page_address(src->pages[i]));
5675 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5676 unsigned long dst_offset, unsigned long src_offset,
5679 u64 dst_len = dst->len;
5684 size_t start_offset = offset_in_page(dst->start);
5685 unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
5687 WARN_ON(src->len != dst_len);
5689 offset = offset_in_page(start_offset + dst_offset);
5692 page = dst->pages[i];
5693 WARN_ON(!PageUptodate(page));
5695 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5697 kaddr = page_address(page);
5698 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5708 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5710 * @eb: the extent buffer
5711 * @start: offset of the bitmap item in the extent buffer
5713 * @page_index: return index of the page in the extent buffer that contains the
5715 * @page_offset: return offset into the page given by page_index
5717 * This helper hides the ugliness of finding the byte in an extent buffer which
5718 * contains a given bit.
5720 static inline void eb_bitmap_offset(struct extent_buffer *eb,
5721 unsigned long start, unsigned long nr,
5722 unsigned long *page_index,
5723 size_t *page_offset)
5725 size_t start_offset = offset_in_page(eb->start);
5726 size_t byte_offset = BIT_BYTE(nr);
5730 * The byte we want is the offset of the extent buffer + the offset of
5731 * the bitmap item in the extent buffer + the offset of the byte in the
5734 offset = start_offset + start + byte_offset;
5736 *page_index = offset >> PAGE_SHIFT;
5737 *page_offset = offset_in_page(offset);
5741 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5742 * @eb: the extent buffer
5743 * @start: offset of the bitmap item in the extent buffer
5744 * @nr: bit number to test
5746 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
5754 eb_bitmap_offset(eb, start, nr, &i, &offset);
5755 page = eb->pages[i];
5756 WARN_ON(!PageUptodate(page));
5757 kaddr = page_address(page);
5758 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5762 * extent_buffer_bitmap_set - set an area of a bitmap
5763 * @eb: the extent buffer
5764 * @start: offset of the bitmap item in the extent buffer
5765 * @pos: bit number of the first bit
5766 * @len: number of bits to set
5768 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
5769 unsigned long pos, unsigned long len)
5775 const unsigned int size = pos + len;
5776 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5777 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5779 eb_bitmap_offset(eb, start, pos, &i, &offset);
5780 page = eb->pages[i];
5781 WARN_ON(!PageUptodate(page));
5782 kaddr = page_address(page);
5784 while (len >= bits_to_set) {
5785 kaddr[offset] |= mask_to_set;
5787 bits_to_set = BITS_PER_BYTE;
5789 if (++offset >= PAGE_SIZE && len > 0) {
5791 page = eb->pages[++i];
5792 WARN_ON(!PageUptodate(page));
5793 kaddr = page_address(page);
5797 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5798 kaddr[offset] |= mask_to_set;
5804 * extent_buffer_bitmap_clear - clear an area of a bitmap
5805 * @eb: the extent buffer
5806 * @start: offset of the bitmap item in the extent buffer
5807 * @pos: bit number of the first bit
5808 * @len: number of bits to clear
5810 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
5811 unsigned long pos, unsigned long len)
5817 const unsigned int size = pos + len;
5818 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5819 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5821 eb_bitmap_offset(eb, start, pos, &i, &offset);
5822 page = eb->pages[i];
5823 WARN_ON(!PageUptodate(page));
5824 kaddr = page_address(page);
5826 while (len >= bits_to_clear) {
5827 kaddr[offset] &= ~mask_to_clear;
5828 len -= bits_to_clear;
5829 bits_to_clear = BITS_PER_BYTE;
5831 if (++offset >= PAGE_SIZE && len > 0) {
5833 page = eb->pages[++i];
5834 WARN_ON(!PageUptodate(page));
5835 kaddr = page_address(page);
5839 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5840 kaddr[offset] &= ~mask_to_clear;
5844 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5846 unsigned long distance = (src > dst) ? src - dst : dst - src;
5847 return distance < len;
5850 static void copy_pages(struct page *dst_page, struct page *src_page,
5851 unsigned long dst_off, unsigned long src_off,
5854 char *dst_kaddr = page_address(dst_page);
5856 int must_memmove = 0;
5858 if (dst_page != src_page) {
5859 src_kaddr = page_address(src_page);
5861 src_kaddr = dst_kaddr;
5862 if (areas_overlap(src_off, dst_off, len))
5867 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5869 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5872 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5873 unsigned long src_offset, unsigned long len)
5875 struct btrfs_fs_info *fs_info = dst->fs_info;
5877 size_t dst_off_in_page;
5878 size_t src_off_in_page;
5879 size_t start_offset = offset_in_page(dst->start);
5880 unsigned long dst_i;
5881 unsigned long src_i;
5883 if (src_offset + len > dst->len) {
5885 "memmove bogus src_offset %lu move len %lu dst len %lu",
5886 src_offset, len, dst->len);
5889 if (dst_offset + len > dst->len) {
5891 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5892 dst_offset, len, dst->len);
5897 dst_off_in_page = offset_in_page(start_offset + dst_offset);
5898 src_off_in_page = offset_in_page(start_offset + src_offset);
5900 dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
5901 src_i = (start_offset + src_offset) >> PAGE_SHIFT;
5903 cur = min(len, (unsigned long)(PAGE_SIZE -
5905 cur = min_t(unsigned long, cur,
5906 (unsigned long)(PAGE_SIZE - dst_off_in_page));
5908 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5909 dst_off_in_page, src_off_in_page, cur);
5917 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5918 unsigned long src_offset, unsigned long len)
5920 struct btrfs_fs_info *fs_info = dst->fs_info;
5922 size_t dst_off_in_page;
5923 size_t src_off_in_page;
5924 unsigned long dst_end = dst_offset + len - 1;
5925 unsigned long src_end = src_offset + len - 1;
5926 size_t start_offset = offset_in_page(dst->start);
5927 unsigned long dst_i;
5928 unsigned long src_i;
5930 if (src_offset + len > dst->len) {
5932 "memmove bogus src_offset %lu move len %lu len %lu",
5933 src_offset, len, dst->len);
5936 if (dst_offset + len > dst->len) {
5938 "memmove bogus dst_offset %lu move len %lu len %lu",
5939 dst_offset, len, dst->len);
5942 if (dst_offset < src_offset) {
5943 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5947 dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
5948 src_i = (start_offset + src_end) >> PAGE_SHIFT;
5950 dst_off_in_page = offset_in_page(start_offset + dst_end);
5951 src_off_in_page = offset_in_page(start_offset + src_end);
5953 cur = min_t(unsigned long, len, src_off_in_page + 1);
5954 cur = min(cur, dst_off_in_page + 1);
5955 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5956 dst_off_in_page - cur + 1,
5957 src_off_in_page - cur + 1, cur);
5965 int try_release_extent_buffer(struct page *page)
5967 struct extent_buffer *eb;
5970 * We need to make sure nobody is attaching this page to an eb right
5973 spin_lock(&page->mapping->private_lock);
5974 if (!PagePrivate(page)) {
5975 spin_unlock(&page->mapping->private_lock);
5979 eb = (struct extent_buffer *)page->private;
5983 * This is a little awful but should be ok, we need to make sure that
5984 * the eb doesn't disappear out from under us while we're looking at
5987 spin_lock(&eb->refs_lock);
5988 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5989 spin_unlock(&eb->refs_lock);
5990 spin_unlock(&page->mapping->private_lock);
5993 spin_unlock(&page->mapping->private_lock);
5996 * If tree ref isn't set then we know the ref on this eb is a real ref,
5997 * so just return, this page will likely be freed soon anyway.
5999 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
6000 spin_unlock(&eb->refs_lock);
6004 return release_extent_buffer(eb);