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-io-tree.h"
18 #include "extent_map.h"
20 #include "btrfs_inode.h"
22 #include "check-integrity.h"
24 #include "rcu-string.h"
28 static struct kmem_cache *extent_state_cache;
29 static struct kmem_cache *extent_buffer_cache;
30 static struct bio_set btrfs_bioset;
32 static inline bool extent_state_in_tree(const struct extent_state *state)
34 return !RB_EMPTY_NODE(&state->rb_node);
37 #ifdef CONFIG_BTRFS_DEBUG
38 static LIST_HEAD(states);
39 static DEFINE_SPINLOCK(leak_lock);
41 static inline void btrfs_leak_debug_add(spinlock_t *lock,
42 struct list_head *new,
43 struct list_head *head)
47 spin_lock_irqsave(lock, flags);
49 spin_unlock_irqrestore(lock, flags);
52 static inline void btrfs_leak_debug_del(spinlock_t *lock,
53 struct list_head *entry)
57 spin_lock_irqsave(lock, flags);
59 spin_unlock_irqrestore(lock, flags);
62 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info)
64 struct extent_buffer *eb;
68 * If we didn't get into open_ctree our allocated_ebs will not be
69 * initialized, so just skip this.
71 if (!fs_info->allocated_ebs.next)
74 spin_lock_irqsave(&fs_info->eb_leak_lock, flags);
75 while (!list_empty(&fs_info->allocated_ebs)) {
76 eb = list_first_entry(&fs_info->allocated_ebs,
77 struct extent_buffer, leak_list);
79 "BTRFS: buffer leak start %llu len %lu refs %d bflags %lu owner %llu\n",
80 eb->start, eb->len, atomic_read(&eb->refs), eb->bflags,
81 btrfs_header_owner(eb));
82 list_del(&eb->leak_list);
83 kmem_cache_free(extent_buffer_cache, eb);
85 spin_unlock_irqrestore(&fs_info->eb_leak_lock, flags);
88 static inline void btrfs_extent_state_leak_debug_check(void)
90 struct extent_state *state;
92 while (!list_empty(&states)) {
93 state = list_entry(states.next, struct extent_state, leak_list);
94 pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
95 state->start, state->end, state->state,
96 extent_state_in_tree(state),
97 refcount_read(&state->refs));
98 list_del(&state->leak_list);
99 kmem_cache_free(extent_state_cache, state);
103 #define btrfs_debug_check_extent_io_range(tree, start, end) \
104 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
105 static inline void __btrfs_debug_check_extent_io_range(const char *caller,
106 struct extent_io_tree *tree, u64 start, u64 end)
108 struct inode *inode = tree->private_data;
111 if (!inode || !is_data_inode(inode))
114 isize = i_size_read(inode);
115 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
116 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
117 "%s: ino %llu isize %llu odd range [%llu,%llu]",
118 caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
122 #define btrfs_leak_debug_add(lock, new, head) do {} while (0)
123 #define btrfs_leak_debug_del(lock, entry) do {} while (0)
124 #define btrfs_extent_state_leak_debug_check() do {} while (0)
125 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
131 struct rb_node rb_node;
134 struct extent_page_data {
136 /* tells writepage not to lock the state bits for this range
137 * it still does the unlocking
139 unsigned int extent_locked:1;
141 /* tells the submit_bio code to use REQ_SYNC */
142 unsigned int sync_io:1;
145 static int add_extent_changeset(struct extent_state *state, unsigned bits,
146 struct extent_changeset *changeset,
153 if (set && (state->state & bits) == bits)
155 if (!set && (state->state & bits) == 0)
157 changeset->bytes_changed += state->end - state->start + 1;
158 ret = ulist_add(&changeset->range_changed, state->start, state->end,
163 static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
164 unsigned long bio_flags)
166 blk_status_t ret = 0;
167 struct extent_io_tree *tree = bio->bi_private;
169 bio->bi_private = NULL;
172 ret = tree->ops->submit_bio_hook(tree->private_data, bio,
173 mirror_num, bio_flags);
175 btrfsic_submit_bio(bio);
177 return blk_status_to_errno(ret);
180 /* Cleanup unsubmitted bios */
181 static void end_write_bio(struct extent_page_data *epd, int ret)
184 epd->bio->bi_status = errno_to_blk_status(ret);
191 * Submit bio from extent page data via submit_one_bio
193 * Return 0 if everything is OK.
194 * Return <0 for error.
196 static int __must_check flush_write_bio(struct extent_page_data *epd)
201 ret = submit_one_bio(epd->bio, 0, 0);
203 * Clean up of epd->bio is handled by its endio function.
204 * And endio is either triggered by successful bio execution
205 * or the error handler of submit bio hook.
206 * So at this point, no matter what happened, we don't need
207 * to clean up epd->bio.
214 int __init extent_state_cache_init(void)
216 extent_state_cache = kmem_cache_create("btrfs_extent_state",
217 sizeof(struct extent_state), 0,
218 SLAB_MEM_SPREAD, NULL);
219 if (!extent_state_cache)
224 int __init extent_io_init(void)
226 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
227 sizeof(struct extent_buffer), 0,
228 SLAB_MEM_SPREAD, NULL);
229 if (!extent_buffer_cache)
232 if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE,
233 offsetof(struct btrfs_io_bio, bio),
235 goto free_buffer_cache;
237 if (bioset_integrity_create(&btrfs_bioset, BIO_POOL_SIZE))
243 bioset_exit(&btrfs_bioset);
246 kmem_cache_destroy(extent_buffer_cache);
247 extent_buffer_cache = NULL;
251 void __cold extent_state_cache_exit(void)
253 btrfs_extent_state_leak_debug_check();
254 kmem_cache_destroy(extent_state_cache);
257 void __cold extent_io_exit(void)
260 * Make sure all delayed rcu free are flushed before we
264 kmem_cache_destroy(extent_buffer_cache);
265 bioset_exit(&btrfs_bioset);
269 * For the file_extent_tree, we want to hold the inode lock when we lookup and
270 * update the disk_i_size, but lockdep will complain because our io_tree we hold
271 * the tree lock and get the inode lock when setting delalloc. These two things
272 * are unrelated, so make a class for the file_extent_tree so we don't get the
273 * two locking patterns mixed up.
275 static struct lock_class_key file_extent_tree_class;
277 void extent_io_tree_init(struct btrfs_fs_info *fs_info,
278 struct extent_io_tree *tree, unsigned int owner,
281 tree->fs_info = fs_info;
282 tree->state = RB_ROOT;
284 tree->dirty_bytes = 0;
285 spin_lock_init(&tree->lock);
286 tree->private_data = private_data;
288 if (owner == IO_TREE_INODE_FILE_EXTENT)
289 lockdep_set_class(&tree->lock, &file_extent_tree_class);
292 void extent_io_tree_release(struct extent_io_tree *tree)
294 spin_lock(&tree->lock);
296 * Do a single barrier for the waitqueue_active check here, the state
297 * of the waitqueue should not change once extent_io_tree_release is
301 while (!RB_EMPTY_ROOT(&tree->state)) {
302 struct rb_node *node;
303 struct extent_state *state;
305 node = rb_first(&tree->state);
306 state = rb_entry(node, struct extent_state, rb_node);
307 rb_erase(&state->rb_node, &tree->state);
308 RB_CLEAR_NODE(&state->rb_node);
310 * btree io trees aren't supposed to have tasks waiting for
311 * changes in the flags of extent states ever.
313 ASSERT(!waitqueue_active(&state->wq));
314 free_extent_state(state);
316 cond_resched_lock(&tree->lock);
318 spin_unlock(&tree->lock);
321 static struct extent_state *alloc_extent_state(gfp_t mask)
323 struct extent_state *state;
326 * The given mask might be not appropriate for the slab allocator,
327 * drop the unsupported bits
329 mask &= ~(__GFP_DMA32|__GFP_HIGHMEM);
330 state = kmem_cache_alloc(extent_state_cache, mask);
334 state->failrec = NULL;
335 RB_CLEAR_NODE(&state->rb_node);
336 btrfs_leak_debug_add(&leak_lock, &state->leak_list, &states);
337 refcount_set(&state->refs, 1);
338 init_waitqueue_head(&state->wq);
339 trace_alloc_extent_state(state, mask, _RET_IP_);
343 void free_extent_state(struct extent_state *state)
347 if (refcount_dec_and_test(&state->refs)) {
348 WARN_ON(extent_state_in_tree(state));
349 btrfs_leak_debug_del(&leak_lock, &state->leak_list);
350 trace_free_extent_state(state, _RET_IP_);
351 kmem_cache_free(extent_state_cache, state);
355 static struct rb_node *tree_insert(struct rb_root *root,
356 struct rb_node *search_start,
358 struct rb_node *node,
359 struct rb_node ***p_in,
360 struct rb_node **parent_in)
363 struct rb_node *parent = NULL;
364 struct tree_entry *entry;
366 if (p_in && parent_in) {
372 p = search_start ? &search_start : &root->rb_node;
375 entry = rb_entry(parent, struct tree_entry, rb_node);
377 if (offset < entry->start)
379 else if (offset > entry->end)
386 rb_link_node(node, parent, p);
387 rb_insert_color(node, root);
392 * __etree_search - searche @tree for an entry that contains @offset. Such
393 * entry would have entry->start <= offset && entry->end >= offset.
395 * @tree - the tree to search
396 * @offset - offset that should fall within an entry in @tree
397 * @next_ret - pointer to the first entry whose range ends after @offset
398 * @prev - pointer to the first entry whose range begins before @offset
399 * @p_ret - pointer where new node should be anchored (used when inserting an
401 * @parent_ret - points to entry which would have been the parent of the entry,
404 * This function returns a pointer to the entry that contains @offset byte
405 * address. If no such entry exists, then NULL is returned and the other
406 * pointer arguments to the function are filled, otherwise the found entry is
407 * returned and other pointers are left untouched.
409 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
410 struct rb_node **next_ret,
411 struct rb_node **prev_ret,
412 struct rb_node ***p_ret,
413 struct rb_node **parent_ret)
415 struct rb_root *root = &tree->state;
416 struct rb_node **n = &root->rb_node;
417 struct rb_node *prev = NULL;
418 struct rb_node *orig_prev = NULL;
419 struct tree_entry *entry;
420 struct tree_entry *prev_entry = NULL;
424 entry = rb_entry(prev, struct tree_entry, rb_node);
427 if (offset < entry->start)
429 else if (offset > entry->end)
442 while (prev && offset > prev_entry->end) {
443 prev = rb_next(prev);
444 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
451 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
452 while (prev && offset < prev_entry->start) {
453 prev = rb_prev(prev);
454 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
461 static inline struct rb_node *
462 tree_search_for_insert(struct extent_io_tree *tree,
464 struct rb_node ***p_ret,
465 struct rb_node **parent_ret)
467 struct rb_node *next= NULL;
470 ret = __etree_search(tree, offset, &next, NULL, p_ret, parent_ret);
476 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
479 return tree_search_for_insert(tree, offset, NULL, NULL);
483 * utility function to look for merge candidates inside a given range.
484 * Any extents with matching state are merged together into a single
485 * extent in the tree. Extents with EXTENT_IO in their state field
486 * are not merged because the end_io handlers need to be able to do
487 * operations on them without sleeping (or doing allocations/splits).
489 * This should be called with the tree lock held.
491 static void merge_state(struct extent_io_tree *tree,
492 struct extent_state *state)
494 struct extent_state *other;
495 struct rb_node *other_node;
497 if (state->state & (EXTENT_LOCKED | EXTENT_BOUNDARY))
500 other_node = rb_prev(&state->rb_node);
502 other = rb_entry(other_node, struct extent_state, rb_node);
503 if (other->end == state->start - 1 &&
504 other->state == state->state) {
505 if (tree->private_data &&
506 is_data_inode(tree->private_data))
507 btrfs_merge_delalloc_extent(tree->private_data,
509 state->start = other->start;
510 rb_erase(&other->rb_node, &tree->state);
511 RB_CLEAR_NODE(&other->rb_node);
512 free_extent_state(other);
515 other_node = rb_next(&state->rb_node);
517 other = rb_entry(other_node, struct extent_state, rb_node);
518 if (other->start == state->end + 1 &&
519 other->state == state->state) {
520 if (tree->private_data &&
521 is_data_inode(tree->private_data))
522 btrfs_merge_delalloc_extent(tree->private_data,
524 state->end = other->end;
525 rb_erase(&other->rb_node, &tree->state);
526 RB_CLEAR_NODE(&other->rb_node);
527 free_extent_state(other);
532 static void set_state_bits(struct extent_io_tree *tree,
533 struct extent_state *state, unsigned *bits,
534 struct extent_changeset *changeset);
537 * insert an extent_state struct into the tree. 'bits' are set on the
538 * struct before it is inserted.
540 * This may return -EEXIST if the extent is already there, in which case the
541 * state struct is freed.
543 * The tree lock is not taken internally. This is a utility function and
544 * probably isn't what you want to call (see set/clear_extent_bit).
546 static int insert_state(struct extent_io_tree *tree,
547 struct extent_state *state, u64 start, u64 end,
549 struct rb_node **parent,
550 unsigned *bits, struct extent_changeset *changeset)
552 struct rb_node *node;
555 btrfs_err(tree->fs_info,
556 "insert state: end < start %llu %llu", end, start);
559 state->start = start;
562 set_state_bits(tree, state, bits, changeset);
564 node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
566 struct extent_state *found;
567 found = rb_entry(node, struct extent_state, rb_node);
568 btrfs_err(tree->fs_info,
569 "found node %llu %llu on insert of %llu %llu",
570 found->start, found->end, start, end);
573 merge_state(tree, state);
578 * split a given extent state struct in two, inserting the preallocated
579 * struct 'prealloc' as the newly created second half. 'split' indicates an
580 * offset inside 'orig' where it should be split.
583 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
584 * are two extent state structs in the tree:
585 * prealloc: [orig->start, split - 1]
586 * orig: [ split, orig->end ]
588 * The tree locks are not taken by this function. They need to be held
591 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
592 struct extent_state *prealloc, u64 split)
594 struct rb_node *node;
596 if (tree->private_data && is_data_inode(tree->private_data))
597 btrfs_split_delalloc_extent(tree->private_data, orig, split);
599 prealloc->start = orig->start;
600 prealloc->end = split - 1;
601 prealloc->state = orig->state;
604 node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
605 &prealloc->rb_node, NULL, NULL);
607 free_extent_state(prealloc);
613 static struct extent_state *next_state(struct extent_state *state)
615 struct rb_node *next = rb_next(&state->rb_node);
617 return rb_entry(next, struct extent_state, rb_node);
623 * utility function to clear some bits in an extent state struct.
624 * it will optionally wake up anyone waiting on this state (wake == 1).
626 * If no bits are set on the state struct after clearing things, the
627 * struct is freed and removed from the tree
629 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
630 struct extent_state *state,
631 unsigned *bits, int wake,
632 struct extent_changeset *changeset)
634 struct extent_state *next;
635 unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
638 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
639 u64 range = state->end - state->start + 1;
640 WARN_ON(range > tree->dirty_bytes);
641 tree->dirty_bytes -= range;
644 if (tree->private_data && is_data_inode(tree->private_data))
645 btrfs_clear_delalloc_extent(tree->private_data, state, bits);
647 ret = add_extent_changeset(state, bits_to_clear, changeset, 0);
649 state->state &= ~bits_to_clear;
652 if (state->state == 0) {
653 next = next_state(state);
654 if (extent_state_in_tree(state)) {
655 rb_erase(&state->rb_node, &tree->state);
656 RB_CLEAR_NODE(&state->rb_node);
657 free_extent_state(state);
662 merge_state(tree, state);
663 next = next_state(state);
668 static struct extent_state *
669 alloc_extent_state_atomic(struct extent_state *prealloc)
672 prealloc = alloc_extent_state(GFP_ATOMIC);
677 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
679 struct inode *inode = tree->private_data;
681 btrfs_panic(btrfs_sb(inode->i_sb), err,
682 "locking error: extent tree was modified by another thread while locked");
686 * clear some bits on a range in the tree. This may require splitting
687 * or inserting elements in the tree, so the gfp mask is used to
688 * indicate which allocations or sleeping are allowed.
690 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
691 * the given range from the tree regardless of state (ie for truncate).
693 * the range [start, end] is inclusive.
695 * This takes the tree lock, and returns 0 on success and < 0 on error.
697 int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
698 unsigned bits, int wake, int delete,
699 struct extent_state **cached_state,
700 gfp_t mask, struct extent_changeset *changeset)
702 struct extent_state *state;
703 struct extent_state *cached;
704 struct extent_state *prealloc = NULL;
705 struct rb_node *node;
710 btrfs_debug_check_extent_io_range(tree, start, end);
711 trace_btrfs_clear_extent_bit(tree, start, end - start + 1, bits);
713 if (bits & EXTENT_DELALLOC)
714 bits |= EXTENT_NORESERVE;
717 bits |= ~EXTENT_CTLBITS;
719 if (bits & (EXTENT_LOCKED | EXTENT_BOUNDARY))
722 if (!prealloc && gfpflags_allow_blocking(mask)) {
724 * Don't care for allocation failure here because we might end
725 * up not needing the pre-allocated extent state at all, which
726 * is the case if we only have in the tree extent states that
727 * cover our input range and don't cover too any other range.
728 * If we end up needing a new extent state we allocate it later.
730 prealloc = alloc_extent_state(mask);
733 spin_lock(&tree->lock);
735 cached = *cached_state;
738 *cached_state = NULL;
742 if (cached && extent_state_in_tree(cached) &&
743 cached->start <= start && cached->end > start) {
745 refcount_dec(&cached->refs);
750 free_extent_state(cached);
753 * this search will find the extents that end after
756 node = tree_search(tree, start);
759 state = rb_entry(node, struct extent_state, rb_node);
761 if (state->start > end)
763 WARN_ON(state->end < start);
764 last_end = state->end;
766 /* the state doesn't have the wanted bits, go ahead */
767 if (!(state->state & bits)) {
768 state = next_state(state);
773 * | ---- desired range ---- |
775 * | ------------- state -------------- |
777 * We need to split the extent we found, and may flip
778 * bits on second half.
780 * If the extent we found extends past our range, we
781 * just split and search again. It'll get split again
782 * the next time though.
784 * If the extent we found is inside our range, we clear
785 * the desired bit on it.
788 if (state->start < start) {
789 prealloc = alloc_extent_state_atomic(prealloc);
791 err = split_state(tree, state, prealloc, start);
793 extent_io_tree_panic(tree, err);
798 if (state->end <= end) {
799 state = clear_state_bit(tree, state, &bits, wake,
806 * | ---- desired range ---- |
808 * We need to split the extent, and clear the bit
811 if (state->start <= end && state->end > end) {
812 prealloc = alloc_extent_state_atomic(prealloc);
814 err = split_state(tree, state, prealloc, end + 1);
816 extent_io_tree_panic(tree, err);
821 clear_state_bit(tree, prealloc, &bits, wake, changeset);
827 state = clear_state_bit(tree, state, &bits, wake, changeset);
829 if (last_end == (u64)-1)
831 start = last_end + 1;
832 if (start <= end && state && !need_resched())
838 spin_unlock(&tree->lock);
839 if (gfpflags_allow_blocking(mask))
844 spin_unlock(&tree->lock);
846 free_extent_state(prealloc);
852 static void wait_on_state(struct extent_io_tree *tree,
853 struct extent_state *state)
854 __releases(tree->lock)
855 __acquires(tree->lock)
858 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
859 spin_unlock(&tree->lock);
861 spin_lock(&tree->lock);
862 finish_wait(&state->wq, &wait);
866 * waits for one or more bits to clear on a range in the state tree.
867 * The range [start, end] is inclusive.
868 * The tree lock is taken by this function
870 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
873 struct extent_state *state;
874 struct rb_node *node;
876 btrfs_debug_check_extent_io_range(tree, start, end);
878 spin_lock(&tree->lock);
882 * this search will find all the extents that end after
885 node = tree_search(tree, start);
890 state = rb_entry(node, struct extent_state, rb_node);
892 if (state->start > end)
895 if (state->state & bits) {
896 start = state->start;
897 refcount_inc(&state->refs);
898 wait_on_state(tree, state);
899 free_extent_state(state);
902 start = state->end + 1;
907 if (!cond_resched_lock(&tree->lock)) {
908 node = rb_next(node);
913 spin_unlock(&tree->lock);
916 static void set_state_bits(struct extent_io_tree *tree,
917 struct extent_state *state,
918 unsigned *bits, struct extent_changeset *changeset)
920 unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
923 if (tree->private_data && is_data_inode(tree->private_data))
924 btrfs_set_delalloc_extent(tree->private_data, state, bits);
926 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
927 u64 range = state->end - state->start + 1;
928 tree->dirty_bytes += range;
930 ret = add_extent_changeset(state, bits_to_set, changeset, 1);
932 state->state |= bits_to_set;
935 static void cache_state_if_flags(struct extent_state *state,
936 struct extent_state **cached_ptr,
939 if (cached_ptr && !(*cached_ptr)) {
940 if (!flags || (state->state & flags)) {
942 refcount_inc(&state->refs);
947 static void cache_state(struct extent_state *state,
948 struct extent_state **cached_ptr)
950 return cache_state_if_flags(state, cached_ptr,
951 EXTENT_LOCKED | EXTENT_BOUNDARY);
955 * set some bits on a range in the tree. This may require allocations or
956 * sleeping, so the gfp mask is used to indicate what is allowed.
958 * If any of the exclusive bits are set, this will fail with -EEXIST if some
959 * part of the range already has the desired bits set. The start of the
960 * existing range is returned in failed_start in this case.
962 * [start, end] is inclusive This takes the tree lock.
965 static int __must_check
966 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
967 unsigned bits, unsigned exclusive_bits,
968 u64 *failed_start, struct extent_state **cached_state,
969 gfp_t mask, struct extent_changeset *changeset)
971 struct extent_state *state;
972 struct extent_state *prealloc = NULL;
973 struct rb_node *node;
975 struct rb_node *parent;
980 btrfs_debug_check_extent_io_range(tree, start, end);
981 trace_btrfs_set_extent_bit(tree, start, end - start + 1, bits);
984 if (!prealloc && gfpflags_allow_blocking(mask)) {
986 * Don't care for allocation failure here because we might end
987 * up not needing the pre-allocated extent state at all, which
988 * is the case if we only have in the tree extent states that
989 * cover our input range and don't cover too any other range.
990 * If we end up needing a new extent state we allocate it later.
992 prealloc = alloc_extent_state(mask);
995 spin_lock(&tree->lock);
996 if (cached_state && *cached_state) {
997 state = *cached_state;
998 if (state->start <= start && state->end > start &&
999 extent_state_in_tree(state)) {
1000 node = &state->rb_node;
1005 * this search will find all the extents that end after
1008 node = tree_search_for_insert(tree, start, &p, &parent);
1010 prealloc = alloc_extent_state_atomic(prealloc);
1012 err = insert_state(tree, prealloc, start, end,
1013 &p, &parent, &bits, changeset);
1015 extent_io_tree_panic(tree, err);
1017 cache_state(prealloc, cached_state);
1021 state = rb_entry(node, struct extent_state, rb_node);
1023 last_start = state->start;
1024 last_end = state->end;
1027 * | ---- desired range ---- |
1030 * Just lock what we found and keep going
1032 if (state->start == start && state->end <= end) {
1033 if (state->state & exclusive_bits) {
1034 *failed_start = state->start;
1039 set_state_bits(tree, state, &bits, changeset);
1040 cache_state(state, cached_state);
1041 merge_state(tree, state);
1042 if (last_end == (u64)-1)
1044 start = last_end + 1;
1045 state = next_state(state);
1046 if (start < end && state && state->start == start &&
1053 * | ---- desired range ---- |
1056 * | ------------- state -------------- |
1058 * We need to split the extent we found, and may flip bits on
1061 * If the extent we found extends past our
1062 * range, we just split and search again. It'll get split
1063 * again the next time though.
1065 * If the extent we found is inside our range, we set the
1066 * desired bit on it.
1068 if (state->start < start) {
1069 if (state->state & exclusive_bits) {
1070 *failed_start = start;
1076 * If this extent already has all the bits we want set, then
1077 * skip it, not necessary to split it or do anything with it.
1079 if ((state->state & bits) == bits) {
1080 start = state->end + 1;
1081 cache_state(state, cached_state);
1085 prealloc = alloc_extent_state_atomic(prealloc);
1087 err = split_state(tree, state, prealloc, start);
1089 extent_io_tree_panic(tree, err);
1094 if (state->end <= end) {
1095 set_state_bits(tree, state, &bits, changeset);
1096 cache_state(state, cached_state);
1097 merge_state(tree, state);
1098 if (last_end == (u64)-1)
1100 start = last_end + 1;
1101 state = next_state(state);
1102 if (start < end && state && state->start == start &&
1109 * | ---- desired range ---- |
1110 * | state | or | state |
1112 * There's a hole, we need to insert something in it and
1113 * ignore the extent we found.
1115 if (state->start > start) {
1117 if (end < last_start)
1120 this_end = last_start - 1;
1122 prealloc = alloc_extent_state_atomic(prealloc);
1126 * Avoid to free 'prealloc' if it can be merged with
1129 err = insert_state(tree, prealloc, start, this_end,
1130 NULL, NULL, &bits, changeset);
1132 extent_io_tree_panic(tree, err);
1134 cache_state(prealloc, cached_state);
1136 start = this_end + 1;
1140 * | ---- desired range ---- |
1142 * We need to split the extent, and set the bit
1145 if (state->start <= end && state->end > end) {
1146 if (state->state & exclusive_bits) {
1147 *failed_start = start;
1152 prealloc = alloc_extent_state_atomic(prealloc);
1154 err = split_state(tree, state, prealloc, end + 1);
1156 extent_io_tree_panic(tree, err);
1158 set_state_bits(tree, prealloc, &bits, changeset);
1159 cache_state(prealloc, cached_state);
1160 merge_state(tree, prealloc);
1168 spin_unlock(&tree->lock);
1169 if (gfpflags_allow_blocking(mask))
1174 spin_unlock(&tree->lock);
1176 free_extent_state(prealloc);
1182 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1183 unsigned bits, u64 * failed_start,
1184 struct extent_state **cached_state, gfp_t mask)
1186 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
1187 cached_state, mask, NULL);
1192 * convert_extent_bit - convert all bits in a given range from one bit to
1194 * @tree: the io tree to search
1195 * @start: the start offset in bytes
1196 * @end: the end offset in bytes (inclusive)
1197 * @bits: the bits to set in this range
1198 * @clear_bits: the bits to clear in this range
1199 * @cached_state: state that we're going to cache
1201 * This will go through and set bits for the given range. If any states exist
1202 * already in this range they are set with the given bit and cleared of the
1203 * clear_bits. This is only meant to be used by things that are mergeable, ie
1204 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1205 * boundary bits like LOCK.
1207 * All allocations are done with GFP_NOFS.
1209 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1210 unsigned bits, unsigned clear_bits,
1211 struct extent_state **cached_state)
1213 struct extent_state *state;
1214 struct extent_state *prealloc = NULL;
1215 struct rb_node *node;
1217 struct rb_node *parent;
1221 bool first_iteration = true;
1223 btrfs_debug_check_extent_io_range(tree, start, end);
1224 trace_btrfs_convert_extent_bit(tree, start, end - start + 1, bits,
1230 * Best effort, don't worry if extent state allocation fails
1231 * here for the first iteration. We might have a cached state
1232 * that matches exactly the target range, in which case no
1233 * extent state allocations are needed. We'll only know this
1234 * after locking the tree.
1236 prealloc = alloc_extent_state(GFP_NOFS);
1237 if (!prealloc && !first_iteration)
1241 spin_lock(&tree->lock);
1242 if (cached_state && *cached_state) {
1243 state = *cached_state;
1244 if (state->start <= start && state->end > start &&
1245 extent_state_in_tree(state)) {
1246 node = &state->rb_node;
1252 * this search will find all the extents that end after
1255 node = tree_search_for_insert(tree, start, &p, &parent);
1257 prealloc = alloc_extent_state_atomic(prealloc);
1262 err = insert_state(tree, prealloc, start, end,
1263 &p, &parent, &bits, NULL);
1265 extent_io_tree_panic(tree, err);
1266 cache_state(prealloc, cached_state);
1270 state = rb_entry(node, struct extent_state, rb_node);
1272 last_start = state->start;
1273 last_end = state->end;
1276 * | ---- desired range ---- |
1279 * Just lock what we found and keep going
1281 if (state->start == start && state->end <= end) {
1282 set_state_bits(tree, state, &bits, NULL);
1283 cache_state(state, cached_state);
1284 state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
1285 if (last_end == (u64)-1)
1287 start = last_end + 1;
1288 if (start < end && state && state->start == start &&
1295 * | ---- desired range ---- |
1298 * | ------------- state -------------- |
1300 * We need to split the extent we found, and may flip bits on
1303 * If the extent we found extends past our
1304 * range, we just split and search again. It'll get split
1305 * again the next time though.
1307 * If the extent we found is inside our range, we set the
1308 * desired bit on it.
1310 if (state->start < start) {
1311 prealloc = alloc_extent_state_atomic(prealloc);
1316 err = split_state(tree, state, prealloc, start);
1318 extent_io_tree_panic(tree, err);
1322 if (state->end <= end) {
1323 set_state_bits(tree, state, &bits, NULL);
1324 cache_state(state, cached_state);
1325 state = clear_state_bit(tree, state, &clear_bits, 0,
1327 if (last_end == (u64)-1)
1329 start = last_end + 1;
1330 if (start < end && state && state->start == start &&
1337 * | ---- desired range ---- |
1338 * | state | or | state |
1340 * There's a hole, we need to insert something in it and
1341 * ignore the extent we found.
1343 if (state->start > start) {
1345 if (end < last_start)
1348 this_end = last_start - 1;
1350 prealloc = alloc_extent_state_atomic(prealloc);
1357 * Avoid to free 'prealloc' if it can be merged with
1360 err = insert_state(tree, prealloc, start, this_end,
1361 NULL, NULL, &bits, NULL);
1363 extent_io_tree_panic(tree, err);
1364 cache_state(prealloc, cached_state);
1366 start = this_end + 1;
1370 * | ---- desired range ---- |
1372 * We need to split the extent, and set the bit
1375 if (state->start <= end && state->end > end) {
1376 prealloc = alloc_extent_state_atomic(prealloc);
1382 err = split_state(tree, state, prealloc, end + 1);
1384 extent_io_tree_panic(tree, err);
1386 set_state_bits(tree, prealloc, &bits, NULL);
1387 cache_state(prealloc, cached_state);
1388 clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
1396 spin_unlock(&tree->lock);
1398 first_iteration = false;
1402 spin_unlock(&tree->lock);
1404 free_extent_state(prealloc);
1409 /* wrappers around set/clear extent bit */
1410 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1411 unsigned bits, struct extent_changeset *changeset)
1414 * We don't support EXTENT_LOCKED yet, as current changeset will
1415 * record any bits changed, so for EXTENT_LOCKED case, it will
1416 * either fail with -EEXIST or changeset will record the whole
1419 BUG_ON(bits & EXTENT_LOCKED);
1421 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
1425 int set_extent_bits_nowait(struct extent_io_tree *tree, u64 start, u64 end,
1428 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL,
1432 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1433 unsigned bits, int wake, int delete,
1434 struct extent_state **cached)
1436 return __clear_extent_bit(tree, start, end, bits, wake, delete,
1437 cached, GFP_NOFS, NULL);
1440 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1441 unsigned bits, struct extent_changeset *changeset)
1444 * Don't support EXTENT_LOCKED case, same reason as
1445 * set_record_extent_bits().
1447 BUG_ON(bits & EXTENT_LOCKED);
1449 return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
1454 * either insert or lock state struct between start and end use mask to tell
1455 * us if waiting is desired.
1457 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1458 struct extent_state **cached_state)
1464 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
1465 EXTENT_LOCKED, &failed_start,
1466 cached_state, GFP_NOFS, NULL);
1467 if (err == -EEXIST) {
1468 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1469 start = failed_start;
1472 WARN_ON(start > end);
1477 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1482 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1483 &failed_start, NULL, GFP_NOFS, NULL);
1484 if (err == -EEXIST) {
1485 if (failed_start > start)
1486 clear_extent_bit(tree, start, failed_start - 1,
1487 EXTENT_LOCKED, 1, 0, NULL);
1493 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1495 unsigned long index = start >> PAGE_SHIFT;
1496 unsigned long end_index = end >> PAGE_SHIFT;
1499 while (index <= end_index) {
1500 page = find_get_page(inode->i_mapping, index);
1501 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1502 clear_page_dirty_for_io(page);
1508 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1510 unsigned long index = start >> PAGE_SHIFT;
1511 unsigned long end_index = end >> PAGE_SHIFT;
1514 while (index <= end_index) {
1515 page = find_get_page(inode->i_mapping, index);
1516 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1517 __set_page_dirty_nobuffers(page);
1518 account_page_redirty(page);
1524 /* find the first state struct with 'bits' set after 'start', and
1525 * return it. tree->lock must be held. NULL will returned if
1526 * nothing was found after 'start'
1528 static struct extent_state *
1529 find_first_extent_bit_state(struct extent_io_tree *tree,
1530 u64 start, unsigned bits)
1532 struct rb_node *node;
1533 struct extent_state *state;
1536 * this search will find all the extents that end after
1539 node = tree_search(tree, start);
1544 state = rb_entry(node, struct extent_state, rb_node);
1545 if (state->end >= start && (state->state & bits))
1548 node = rb_next(node);
1557 * find the first offset in the io tree with 'bits' set. zero is
1558 * returned if we find something, and *start_ret and *end_ret are
1559 * set to reflect the state struct that was found.
1561 * If nothing was found, 1 is returned. If found something, return 0.
1563 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1564 u64 *start_ret, u64 *end_ret, unsigned bits,
1565 struct extent_state **cached_state)
1567 struct extent_state *state;
1570 spin_lock(&tree->lock);
1571 if (cached_state && *cached_state) {
1572 state = *cached_state;
1573 if (state->end == start - 1 && extent_state_in_tree(state)) {
1574 while ((state = next_state(state)) != NULL) {
1575 if (state->state & bits)
1578 free_extent_state(*cached_state);
1579 *cached_state = NULL;
1582 free_extent_state(*cached_state);
1583 *cached_state = NULL;
1586 state = find_first_extent_bit_state(tree, start, bits);
1589 cache_state_if_flags(state, cached_state, 0);
1590 *start_ret = state->start;
1591 *end_ret = state->end;
1595 spin_unlock(&tree->lock);
1600 * find_contiguous_extent_bit: find a contiguous area of bits
1601 * @tree - io tree to check
1602 * @start - offset to start the search from
1603 * @start_ret - the first offset we found with the bits set
1604 * @end_ret - the final contiguous range of the bits that were set
1605 * @bits - bits to look for
1607 * set_extent_bit and clear_extent_bit can temporarily split contiguous ranges
1608 * to set bits appropriately, and then merge them again. During this time it
1609 * will drop the tree->lock, so use this helper if you want to find the actual
1610 * contiguous area for given bits. We will search to the first bit we find, and
1611 * then walk down the tree until we find a non-contiguous area. The area
1612 * returned will be the full contiguous area with the bits set.
1614 int find_contiguous_extent_bit(struct extent_io_tree *tree, u64 start,
1615 u64 *start_ret, u64 *end_ret, unsigned bits)
1617 struct extent_state *state;
1620 spin_lock(&tree->lock);
1621 state = find_first_extent_bit_state(tree, start, bits);
1623 *start_ret = state->start;
1624 *end_ret = state->end;
1625 while ((state = next_state(state)) != NULL) {
1626 if (state->start > (*end_ret + 1))
1628 *end_ret = state->end;
1632 spin_unlock(&tree->lock);
1637 * find_first_clear_extent_bit - find the first range that has @bits not set.
1638 * This range could start before @start.
1640 * @tree - the tree to search
1641 * @start - the offset at/after which the found extent should start
1642 * @start_ret - records the beginning of the range
1643 * @end_ret - records the end of the range (inclusive)
1644 * @bits - the set of bits which must be unset
1646 * Since unallocated range is also considered one which doesn't have the bits
1647 * set it's possible that @end_ret contains -1, this happens in case the range
1648 * spans (last_range_end, end of device]. In this case it's up to the caller to
1649 * trim @end_ret to the appropriate size.
1651 void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start,
1652 u64 *start_ret, u64 *end_ret, unsigned bits)
1654 struct extent_state *state;
1655 struct rb_node *node, *prev = NULL, *next;
1657 spin_lock(&tree->lock);
1659 /* Find first extent with bits cleared */
1661 node = __etree_search(tree, start, &next, &prev, NULL, NULL);
1662 if (!node && !next && !prev) {
1664 * Tree is completely empty, send full range and let
1665 * caller deal with it
1670 } else if (!node && !next) {
1672 * We are past the last allocated chunk, set start at
1673 * the end of the last extent.
1675 state = rb_entry(prev, struct extent_state, rb_node);
1676 *start_ret = state->end + 1;
1683 * At this point 'node' either contains 'start' or start is
1686 state = rb_entry(node, struct extent_state, rb_node);
1688 if (in_range(start, state->start, state->end - state->start + 1)) {
1689 if (state->state & bits) {
1691 * |--range with bits sets--|
1695 start = state->end + 1;
1698 * 'start' falls within a range that doesn't
1699 * have the bits set, so take its start as
1700 * the beginning of the desired range
1702 * |--range with bits cleared----|
1706 *start_ret = state->start;
1711 * |---prev range---|---hole/unset---|---node range---|
1717 * |---hole/unset--||--first node--|
1722 state = rb_entry(prev, struct extent_state,
1724 *start_ret = state->end + 1;
1733 * Find the longest stretch from start until an entry which has the
1737 state = rb_entry(node, struct extent_state, rb_node);
1738 if (state->end >= start && !(state->state & bits)) {
1739 *end_ret = state->end;
1741 *end_ret = state->start - 1;
1745 node = rb_next(node);
1750 spin_unlock(&tree->lock);
1754 * find a contiguous range of bytes in the file marked as delalloc, not
1755 * more than 'max_bytes'. start and end are used to return the range,
1757 * true is returned if we find something, false if nothing was in the tree
1759 bool btrfs_find_delalloc_range(struct extent_io_tree *tree, u64 *start,
1760 u64 *end, u64 max_bytes,
1761 struct extent_state **cached_state)
1763 struct rb_node *node;
1764 struct extent_state *state;
1765 u64 cur_start = *start;
1767 u64 total_bytes = 0;
1769 spin_lock(&tree->lock);
1772 * this search will find all the extents that end after
1775 node = tree_search(tree, cur_start);
1782 state = rb_entry(node, struct extent_state, rb_node);
1783 if (found && (state->start != cur_start ||
1784 (state->state & EXTENT_BOUNDARY))) {
1787 if (!(state->state & EXTENT_DELALLOC)) {
1793 *start = state->start;
1794 *cached_state = state;
1795 refcount_inc(&state->refs);
1799 cur_start = state->end + 1;
1800 node = rb_next(node);
1801 total_bytes += state->end - state->start + 1;
1802 if (total_bytes >= max_bytes)
1808 spin_unlock(&tree->lock);
1812 static int __process_pages_contig(struct address_space *mapping,
1813 struct page *locked_page,
1814 pgoff_t start_index, pgoff_t end_index,
1815 unsigned long page_ops, pgoff_t *index_ret);
1817 static noinline void __unlock_for_delalloc(struct inode *inode,
1818 struct page *locked_page,
1821 unsigned long index = start >> PAGE_SHIFT;
1822 unsigned long end_index = end >> PAGE_SHIFT;
1824 ASSERT(locked_page);
1825 if (index == locked_page->index && end_index == index)
1828 __process_pages_contig(inode->i_mapping, locked_page, index, end_index,
1832 static noinline int lock_delalloc_pages(struct inode *inode,
1833 struct page *locked_page,
1837 unsigned long index = delalloc_start >> PAGE_SHIFT;
1838 unsigned long index_ret = index;
1839 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1842 ASSERT(locked_page);
1843 if (index == locked_page->index && index == end_index)
1846 ret = __process_pages_contig(inode->i_mapping, locked_page, index,
1847 end_index, PAGE_LOCK, &index_ret);
1849 __unlock_for_delalloc(inode, locked_page, delalloc_start,
1850 (u64)index_ret << PAGE_SHIFT);
1855 * Find and lock a contiguous range of bytes in the file marked as delalloc, no
1856 * more than @max_bytes. @Start and @end are used to return the range,
1858 * Return: true if we find something
1859 * false if nothing was in the tree
1862 noinline_for_stack bool find_lock_delalloc_range(struct inode *inode,
1863 struct page *locked_page, u64 *start,
1866 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
1867 u64 max_bytes = BTRFS_MAX_EXTENT_SIZE;
1871 struct extent_state *cached_state = NULL;
1876 /* step one, find a bunch of delalloc bytes starting at start */
1877 delalloc_start = *start;
1879 found = btrfs_find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1880 max_bytes, &cached_state);
1881 if (!found || delalloc_end <= *start) {
1882 *start = delalloc_start;
1883 *end = delalloc_end;
1884 free_extent_state(cached_state);
1889 * start comes from the offset of locked_page. We have to lock
1890 * pages in order, so we can't process delalloc bytes before
1893 if (delalloc_start < *start)
1894 delalloc_start = *start;
1897 * make sure to limit the number of pages we try to lock down
1899 if (delalloc_end + 1 - delalloc_start > max_bytes)
1900 delalloc_end = delalloc_start + max_bytes - 1;
1902 /* step two, lock all the pages after the page that has start */
1903 ret = lock_delalloc_pages(inode, locked_page,
1904 delalloc_start, delalloc_end);
1905 ASSERT(!ret || ret == -EAGAIN);
1906 if (ret == -EAGAIN) {
1907 /* some of the pages are gone, lets avoid looping by
1908 * shortening the size of the delalloc range we're searching
1910 free_extent_state(cached_state);
1911 cached_state = NULL;
1913 max_bytes = PAGE_SIZE;
1922 /* step three, lock the state bits for the whole range */
1923 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1925 /* then test to make sure it is all still delalloc */
1926 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1927 EXTENT_DELALLOC, 1, cached_state);
1929 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1931 __unlock_for_delalloc(inode, locked_page,
1932 delalloc_start, delalloc_end);
1936 free_extent_state(cached_state);
1937 *start = delalloc_start;
1938 *end = delalloc_end;
1943 static int __process_pages_contig(struct address_space *mapping,
1944 struct page *locked_page,
1945 pgoff_t start_index, pgoff_t end_index,
1946 unsigned long page_ops, pgoff_t *index_ret)
1948 unsigned long nr_pages = end_index - start_index + 1;
1949 unsigned long pages_locked = 0;
1950 pgoff_t index = start_index;
1951 struct page *pages[16];
1956 if (page_ops & PAGE_LOCK) {
1957 ASSERT(page_ops == PAGE_LOCK);
1958 ASSERT(index_ret && *index_ret == start_index);
1961 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1962 mapping_set_error(mapping, -EIO);
1964 while (nr_pages > 0) {
1965 ret = find_get_pages_contig(mapping, index,
1966 min_t(unsigned long,
1967 nr_pages, ARRAY_SIZE(pages)), pages);
1970 * Only if we're going to lock these pages,
1971 * can we find nothing at @index.
1973 ASSERT(page_ops & PAGE_LOCK);
1978 for (i = 0; i < ret; i++) {
1979 if (page_ops & PAGE_SET_PRIVATE2)
1980 SetPagePrivate2(pages[i]);
1982 if (locked_page && pages[i] == locked_page) {
1987 if (page_ops & PAGE_CLEAR_DIRTY)
1988 clear_page_dirty_for_io(pages[i]);
1989 if (page_ops & PAGE_SET_WRITEBACK)
1990 set_page_writeback(pages[i]);
1991 if (page_ops & PAGE_SET_ERROR)
1992 SetPageError(pages[i]);
1993 if (page_ops & PAGE_END_WRITEBACK)
1994 end_page_writeback(pages[i]);
1995 if (page_ops & PAGE_UNLOCK)
1996 unlock_page(pages[i]);
1997 if (page_ops & PAGE_LOCK) {
1998 lock_page(pages[i]);
1999 if (!PageDirty(pages[i]) ||
2000 pages[i]->mapping != mapping) {
2001 unlock_page(pages[i]);
2015 if (err && index_ret)
2016 *index_ret = start_index + pages_locked - 1;
2020 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
2021 struct page *locked_page,
2022 unsigned clear_bits,
2023 unsigned long page_ops)
2025 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0,
2028 __process_pages_contig(inode->i_mapping, locked_page,
2029 start >> PAGE_SHIFT, end >> PAGE_SHIFT,
2034 * count the number of bytes in the tree that have a given bit(s)
2035 * set. This can be fairly slow, except for EXTENT_DIRTY which is
2036 * cached. The total number found is returned.
2038 u64 count_range_bits(struct extent_io_tree *tree,
2039 u64 *start, u64 search_end, u64 max_bytes,
2040 unsigned bits, int contig)
2042 struct rb_node *node;
2043 struct extent_state *state;
2044 u64 cur_start = *start;
2045 u64 total_bytes = 0;
2049 if (WARN_ON(search_end <= cur_start))
2052 spin_lock(&tree->lock);
2053 if (cur_start == 0 && bits == EXTENT_DIRTY) {
2054 total_bytes = tree->dirty_bytes;
2058 * this search will find all the extents that end after
2061 node = tree_search(tree, cur_start);
2066 state = rb_entry(node, struct extent_state, rb_node);
2067 if (state->start > search_end)
2069 if (contig && found && state->start > last + 1)
2071 if (state->end >= cur_start && (state->state & bits) == bits) {
2072 total_bytes += min(search_end, state->end) + 1 -
2073 max(cur_start, state->start);
2074 if (total_bytes >= max_bytes)
2077 *start = max(cur_start, state->start);
2081 } else if (contig && found) {
2084 node = rb_next(node);
2089 spin_unlock(&tree->lock);
2094 * set the private field for a given byte offset in the tree. If there isn't
2095 * an extent_state there already, this does nothing.
2097 int set_state_failrec(struct extent_io_tree *tree, u64 start,
2098 struct io_failure_record *failrec)
2100 struct rb_node *node;
2101 struct extent_state *state;
2104 spin_lock(&tree->lock);
2106 * this search will find all the extents that end after
2109 node = tree_search(tree, start);
2114 state = rb_entry(node, struct extent_state, rb_node);
2115 if (state->start != start) {
2119 state->failrec = failrec;
2121 spin_unlock(&tree->lock);
2125 int get_state_failrec(struct extent_io_tree *tree, u64 start,
2126 struct io_failure_record **failrec)
2128 struct rb_node *node;
2129 struct extent_state *state;
2132 spin_lock(&tree->lock);
2134 * this search will find all the extents that end after
2137 node = tree_search(tree, start);
2142 state = rb_entry(node, struct extent_state, rb_node);
2143 if (state->start != start) {
2147 *failrec = state->failrec;
2149 spin_unlock(&tree->lock);
2154 * searches a range in the state tree for a given mask.
2155 * If 'filled' == 1, this returns 1 only if every extent in the tree
2156 * has the bits set. Otherwise, 1 is returned if any bit in the
2157 * range is found set.
2159 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
2160 unsigned bits, int filled, struct extent_state *cached)
2162 struct extent_state *state = NULL;
2163 struct rb_node *node;
2166 spin_lock(&tree->lock);
2167 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
2168 cached->end > start)
2169 node = &cached->rb_node;
2171 node = tree_search(tree, start);
2172 while (node && start <= end) {
2173 state = rb_entry(node, struct extent_state, rb_node);
2175 if (filled && state->start > start) {
2180 if (state->start > end)
2183 if (state->state & bits) {
2187 } else if (filled) {
2192 if (state->end == (u64)-1)
2195 start = state->end + 1;
2198 node = rb_next(node);
2205 spin_unlock(&tree->lock);
2210 * helper function to set a given page up to date if all the
2211 * extents in the tree for that page are up to date
2213 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
2215 u64 start = page_offset(page);
2216 u64 end = start + PAGE_SIZE - 1;
2217 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
2218 SetPageUptodate(page);
2221 int free_io_failure(struct extent_io_tree *failure_tree,
2222 struct extent_io_tree *io_tree,
2223 struct io_failure_record *rec)
2228 set_state_failrec(failure_tree, rec->start, NULL);
2229 ret = clear_extent_bits(failure_tree, rec->start,
2230 rec->start + rec->len - 1,
2231 EXTENT_LOCKED | EXTENT_DIRTY);
2235 ret = clear_extent_bits(io_tree, rec->start,
2236 rec->start + rec->len - 1,
2246 * this bypasses the standard btrfs submit functions deliberately, as
2247 * the standard behavior is to write all copies in a raid setup. here we only
2248 * want to write the one bad copy. so we do the mapping for ourselves and issue
2249 * submit_bio directly.
2250 * to avoid any synchronization issues, wait for the data after writing, which
2251 * actually prevents the read that triggered the error from finishing.
2252 * currently, there can be no more than two copies of every data bit. thus,
2253 * exactly one rewrite is required.
2255 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
2256 u64 length, u64 logical, struct page *page,
2257 unsigned int pg_offset, int mirror_num)
2260 struct btrfs_device *dev;
2263 struct btrfs_bio *bbio = NULL;
2266 ASSERT(!(fs_info->sb->s_flags & SB_RDONLY));
2267 BUG_ON(!mirror_num);
2269 bio = btrfs_io_bio_alloc(1);
2270 bio->bi_iter.bi_size = 0;
2271 map_length = length;
2274 * Avoid races with device replace and make sure our bbio has devices
2275 * associated to its stripes that don't go away while we are doing the
2276 * read repair operation.
2278 btrfs_bio_counter_inc_blocked(fs_info);
2279 if (btrfs_is_parity_mirror(fs_info, logical, length)) {
2281 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
2282 * to update all raid stripes, but here we just want to correct
2283 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
2284 * stripe's dev and sector.
2286 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical,
2287 &map_length, &bbio, 0);
2289 btrfs_bio_counter_dec(fs_info);
2293 ASSERT(bbio->mirror_num == 1);
2295 ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
2296 &map_length, &bbio, mirror_num);
2298 btrfs_bio_counter_dec(fs_info);
2302 BUG_ON(mirror_num != bbio->mirror_num);
2305 sector = bbio->stripes[bbio->mirror_num - 1].physical >> 9;
2306 bio->bi_iter.bi_sector = sector;
2307 dev = bbio->stripes[bbio->mirror_num - 1].dev;
2308 btrfs_put_bbio(bbio);
2309 if (!dev || !dev->bdev ||
2310 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
2311 btrfs_bio_counter_dec(fs_info);
2315 bio_set_dev(bio, dev->bdev);
2316 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
2317 bio_add_page(bio, page, length, pg_offset);
2319 if (btrfsic_submit_bio_wait(bio)) {
2320 /* try to remap that extent elsewhere? */
2321 btrfs_bio_counter_dec(fs_info);
2323 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2327 btrfs_info_rl_in_rcu(fs_info,
2328 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2330 rcu_str_deref(dev->name), sector);
2331 btrfs_bio_counter_dec(fs_info);
2336 int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num)
2338 struct btrfs_fs_info *fs_info = eb->fs_info;
2339 u64 start = eb->start;
2340 int i, num_pages = num_extent_pages(eb);
2343 if (sb_rdonly(fs_info->sb))
2346 for (i = 0; i < num_pages; i++) {
2347 struct page *p = eb->pages[i];
2349 ret = repair_io_failure(fs_info, 0, start, PAGE_SIZE, start, p,
2350 start - page_offset(p), mirror_num);
2360 * each time an IO finishes, we do a fast check in the IO failure tree
2361 * to see if we need to process or clean up an io_failure_record
2363 int clean_io_failure(struct btrfs_fs_info *fs_info,
2364 struct extent_io_tree *failure_tree,
2365 struct extent_io_tree *io_tree, u64 start,
2366 struct page *page, u64 ino, unsigned int pg_offset)
2369 struct io_failure_record *failrec;
2370 struct extent_state *state;
2375 ret = count_range_bits(failure_tree, &private, (u64)-1, 1,
2380 ret = get_state_failrec(failure_tree, start, &failrec);
2384 BUG_ON(!failrec->this_mirror);
2386 if (failrec->in_validation) {
2387 /* there was no real error, just free the record */
2388 btrfs_debug(fs_info,
2389 "clean_io_failure: freeing dummy error at %llu",
2393 if (sb_rdonly(fs_info->sb))
2396 spin_lock(&io_tree->lock);
2397 state = find_first_extent_bit_state(io_tree,
2400 spin_unlock(&io_tree->lock);
2402 if (state && state->start <= failrec->start &&
2403 state->end >= failrec->start + failrec->len - 1) {
2404 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2406 if (num_copies > 1) {
2407 repair_io_failure(fs_info, ino, start, failrec->len,
2408 failrec->logical, page, pg_offset,
2409 failrec->failed_mirror);
2414 free_io_failure(failure_tree, io_tree, failrec);
2420 * Can be called when
2421 * - hold extent lock
2422 * - under ordered extent
2423 * - the inode is freeing
2425 void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end)
2427 struct extent_io_tree *failure_tree = &inode->io_failure_tree;
2428 struct io_failure_record *failrec;
2429 struct extent_state *state, *next;
2431 if (RB_EMPTY_ROOT(&failure_tree->state))
2434 spin_lock(&failure_tree->lock);
2435 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2437 if (state->start > end)
2440 ASSERT(state->end <= end);
2442 next = next_state(state);
2444 failrec = state->failrec;
2445 free_extent_state(state);
2450 spin_unlock(&failure_tree->lock);
2453 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2454 struct io_failure_record **failrec_ret)
2456 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2457 struct io_failure_record *failrec;
2458 struct extent_map *em;
2459 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2460 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2461 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2465 ret = get_state_failrec(failure_tree, start, &failrec);
2467 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2471 failrec->start = start;
2472 failrec->len = end - start + 1;
2473 failrec->this_mirror = 0;
2474 failrec->bio_flags = 0;
2475 failrec->in_validation = 0;
2477 read_lock(&em_tree->lock);
2478 em = lookup_extent_mapping(em_tree, start, failrec->len);
2480 read_unlock(&em_tree->lock);
2485 if (em->start > start || em->start + em->len <= start) {
2486 free_extent_map(em);
2489 read_unlock(&em_tree->lock);
2495 logical = start - em->start;
2496 logical = em->block_start + logical;
2497 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2498 logical = em->block_start;
2499 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2500 extent_set_compress_type(&failrec->bio_flags,
2504 btrfs_debug(fs_info,
2505 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2506 logical, start, failrec->len);
2508 failrec->logical = logical;
2509 free_extent_map(em);
2511 /* set the bits in the private failure tree */
2512 ret = set_extent_bits(failure_tree, start, end,
2513 EXTENT_LOCKED | EXTENT_DIRTY);
2515 ret = set_state_failrec(failure_tree, start, failrec);
2516 /* set the bits in the inode's tree */
2518 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2524 btrfs_debug(fs_info,
2525 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2526 failrec->logical, failrec->start, failrec->len,
2527 failrec->in_validation);
2529 * when data can be on disk more than twice, add to failrec here
2530 * (e.g. with a list for failed_mirror) to make
2531 * clean_io_failure() clean all those errors at once.
2535 *failrec_ret = failrec;
2540 static bool btrfs_check_repairable(struct inode *inode, bool needs_validation,
2541 struct io_failure_record *failrec,
2544 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2547 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
2548 if (num_copies == 1) {
2550 * we only have a single copy of the data, so don't bother with
2551 * all the retry and error correction code that follows. no
2552 * matter what the error is, it is very likely to persist.
2554 btrfs_debug(fs_info,
2555 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2556 num_copies, failrec->this_mirror, failed_mirror);
2561 * there are two premises:
2562 * a) deliver good data to the caller
2563 * b) correct the bad sectors on disk
2565 if (needs_validation) {
2567 * to fulfill b), we need to know the exact failing sectors, as
2568 * we don't want to rewrite any more than the failed ones. thus,
2569 * we need separate read requests for the failed bio
2571 * if the following BUG_ON triggers, our validation request got
2572 * merged. we need separate requests for our algorithm to work.
2574 BUG_ON(failrec->in_validation);
2575 failrec->in_validation = 1;
2576 failrec->this_mirror = failed_mirror;
2579 * we're ready to fulfill a) and b) alongside. get a good copy
2580 * of the failed sector and if we succeed, we have setup
2581 * everything for repair_io_failure to do the rest for us.
2583 if (failrec->in_validation) {
2584 BUG_ON(failrec->this_mirror != failed_mirror);
2585 failrec->in_validation = 0;
2586 failrec->this_mirror = 0;
2588 failrec->failed_mirror = failed_mirror;
2589 failrec->this_mirror++;
2590 if (failrec->this_mirror == failed_mirror)
2591 failrec->this_mirror++;
2594 if (failrec->this_mirror > num_copies) {
2595 btrfs_debug(fs_info,
2596 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2597 num_copies, failrec->this_mirror, failed_mirror);
2604 static bool btrfs_io_needs_validation(struct inode *inode, struct bio *bio)
2607 const u32 blocksize = inode->i_sb->s_blocksize;
2610 * If bi_status is BLK_STS_OK, then this was a checksum error, not an
2611 * I/O error. In this case, we already know exactly which sector was
2612 * bad, so we don't need to validate.
2614 if (bio->bi_status == BLK_STS_OK)
2618 * We need to validate each sector individually if the failed I/O was
2619 * for multiple sectors.
2621 * There are a few possible bios that can end up here:
2622 * 1. A buffered read bio, which is not cloned.
2623 * 2. A direct I/O read bio, which is cloned.
2624 * 3. A (buffered or direct) repair bio, which is not cloned.
2626 * For cloned bios (case 2), we can get the size from
2627 * btrfs_io_bio->iter; for non-cloned bios (cases 1 and 3), we can get
2628 * it from the bvecs.
2630 if (bio_flagged(bio, BIO_CLONED)) {
2631 if (btrfs_io_bio(bio)->iter.bi_size > blocksize)
2634 struct bio_vec *bvec;
2637 bio_for_each_bvec_all(bvec, bio, i) {
2638 len += bvec->bv_len;
2639 if (len > blocksize)
2646 blk_status_t btrfs_submit_read_repair(struct inode *inode,
2647 struct bio *failed_bio, u64 phy_offset,
2648 struct page *page, unsigned int pgoff,
2649 u64 start, u64 end, int failed_mirror,
2650 submit_bio_hook_t *submit_bio_hook)
2652 struct io_failure_record *failrec;
2653 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2654 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2655 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2656 struct btrfs_io_bio *failed_io_bio = btrfs_io_bio(failed_bio);
2657 const int icsum = phy_offset >> inode->i_sb->s_blocksize_bits;
2658 bool need_validation;
2659 struct bio *repair_bio;
2660 struct btrfs_io_bio *repair_io_bio;
2661 blk_status_t status;
2664 btrfs_debug(fs_info,
2665 "repair read error: read error at %llu", start);
2667 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2669 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2671 return errno_to_blk_status(ret);
2673 need_validation = btrfs_io_needs_validation(inode, failed_bio);
2675 if (!btrfs_check_repairable(inode, need_validation, failrec,
2677 free_io_failure(failure_tree, tree, failrec);
2678 return BLK_STS_IOERR;
2681 repair_bio = btrfs_io_bio_alloc(1);
2682 repair_io_bio = btrfs_io_bio(repair_bio);
2683 repair_bio->bi_opf = REQ_OP_READ;
2684 if (need_validation)
2685 repair_bio->bi_opf |= REQ_FAILFAST_DEV;
2686 repair_bio->bi_end_io = failed_bio->bi_end_io;
2687 repair_bio->bi_iter.bi_sector = failrec->logical >> 9;
2688 repair_bio->bi_private = failed_bio->bi_private;
2690 if (failed_io_bio->csum) {
2691 const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2693 repair_io_bio->csum = repair_io_bio->csum_inline;
2694 memcpy(repair_io_bio->csum,
2695 failed_io_bio->csum + csum_size * icsum, csum_size);
2698 bio_add_page(repair_bio, page, failrec->len, pgoff);
2699 repair_io_bio->logical = failrec->start;
2700 repair_io_bio->iter = repair_bio->bi_iter;
2702 btrfs_debug(btrfs_sb(inode->i_sb),
2703 "repair read error: submitting new read to mirror %d, in_validation=%d",
2704 failrec->this_mirror, failrec->in_validation);
2706 status = submit_bio_hook(inode, repair_bio, failrec->this_mirror,
2707 failrec->bio_flags);
2709 free_io_failure(failure_tree, tree, failrec);
2710 bio_put(repair_bio);
2715 /* lots and lots of room for performance fixes in the end_bio funcs */
2717 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2719 int uptodate = (err == 0);
2722 btrfs_writepage_endio_finish_ordered(page, start, end, uptodate);
2725 ClearPageUptodate(page);
2727 ret = err < 0 ? err : -EIO;
2728 mapping_set_error(page->mapping, ret);
2733 * after a writepage IO is done, we need to:
2734 * clear the uptodate bits on error
2735 * clear the writeback bits in the extent tree for this IO
2736 * end_page_writeback if the page has no more pending IO
2738 * Scheduling is not allowed, so the extent state tree is expected
2739 * to have one and only one object corresponding to this IO.
2741 static void end_bio_extent_writepage(struct bio *bio)
2743 int error = blk_status_to_errno(bio->bi_status);
2744 struct bio_vec *bvec;
2747 struct bvec_iter_all iter_all;
2749 ASSERT(!bio_flagged(bio, BIO_CLONED));
2750 bio_for_each_segment_all(bvec, bio, iter_all) {
2751 struct page *page = bvec->bv_page;
2752 struct inode *inode = page->mapping->host;
2753 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2755 /* We always issue full-page reads, but if some block
2756 * in a page fails to read, blk_update_request() will
2757 * advance bv_offset and adjust bv_len to compensate.
2758 * Print a warning for nonzero offsets, and an error
2759 * if they don't add up to a full page. */
2760 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2761 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2763 "partial page write in btrfs with offset %u and length %u",
2764 bvec->bv_offset, bvec->bv_len);
2767 "incomplete page write in btrfs with offset %u and length %u",
2768 bvec->bv_offset, bvec->bv_len);
2771 start = page_offset(page);
2772 end = start + bvec->bv_offset + bvec->bv_len - 1;
2774 end_extent_writepage(page, error, start, end);
2775 end_page_writeback(page);
2782 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2785 struct extent_state *cached = NULL;
2786 u64 end = start + len - 1;
2788 if (uptodate && tree->track_uptodate)
2789 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2790 unlock_extent_cached_atomic(tree, start, end, &cached);
2794 * after a readpage IO is done, we need to:
2795 * clear the uptodate bits on error
2796 * set the uptodate bits if things worked
2797 * set the page up to date if all extents in the tree are uptodate
2798 * clear the lock bit in the extent tree
2799 * unlock the page if there are no other extents locked for it
2801 * Scheduling is not allowed, so the extent state tree is expected
2802 * to have one and only one object corresponding to this IO.
2804 static void end_bio_extent_readpage(struct bio *bio)
2806 struct bio_vec *bvec;
2807 int uptodate = !bio->bi_status;
2808 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2809 struct extent_io_tree *tree, *failure_tree;
2814 u64 extent_start = 0;
2818 struct bvec_iter_all iter_all;
2820 ASSERT(!bio_flagged(bio, BIO_CLONED));
2821 bio_for_each_segment_all(bvec, bio, iter_all) {
2822 struct page *page = bvec->bv_page;
2823 struct inode *inode = page->mapping->host;
2824 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2825 bool data_inode = btrfs_ino(BTRFS_I(inode))
2826 != BTRFS_BTREE_INODE_OBJECTID;
2828 btrfs_debug(fs_info,
2829 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2830 (u64)bio->bi_iter.bi_sector, bio->bi_status,
2831 io_bio->mirror_num);
2832 tree = &BTRFS_I(inode)->io_tree;
2833 failure_tree = &BTRFS_I(inode)->io_failure_tree;
2835 /* We always issue full-page reads, but if some block
2836 * in a page fails to read, blk_update_request() will
2837 * advance bv_offset and adjust bv_len to compensate.
2838 * Print a warning for nonzero offsets, and an error
2839 * if they don't add up to a full page. */
2840 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2841 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2843 "partial page read in btrfs with offset %u and length %u",
2844 bvec->bv_offset, bvec->bv_len);
2847 "incomplete page read in btrfs with offset %u and length %u",
2848 bvec->bv_offset, bvec->bv_len);
2851 start = page_offset(page);
2852 end = start + bvec->bv_offset + bvec->bv_len - 1;
2855 mirror = io_bio->mirror_num;
2856 if (likely(uptodate)) {
2857 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2863 clean_io_failure(BTRFS_I(inode)->root->fs_info,
2864 failure_tree, tree, start,
2866 btrfs_ino(BTRFS_I(inode)), 0);
2869 if (likely(uptodate))
2875 * The generic bio_readpage_error handles errors the
2876 * following way: If possible, new read requests are
2877 * created and submitted and will end up in
2878 * end_bio_extent_readpage as well (if we're lucky,
2879 * not in the !uptodate case). In that case it returns
2880 * 0 and we just go on with the next page in our bio.
2881 * If it can't handle the error it will return -EIO and
2882 * we remain responsible for that page.
2884 if (!btrfs_submit_read_repair(inode, bio, offset, page,
2885 start - page_offset(page),
2887 tree->ops->submit_bio_hook)) {
2888 uptodate = !bio->bi_status;
2893 struct extent_buffer *eb;
2895 eb = (struct extent_buffer *)page->private;
2896 set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
2897 eb->read_mirror = mirror;
2898 atomic_dec(&eb->io_pages);
2899 if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD,
2901 btree_readahead_hook(eb, -EIO);
2904 if (likely(uptodate)) {
2905 loff_t i_size = i_size_read(inode);
2906 pgoff_t end_index = i_size >> PAGE_SHIFT;
2909 /* Zero out the end if this page straddles i_size */
2910 off = offset_in_page(i_size);
2911 if (page->index == end_index && off)
2912 zero_user_segment(page, off, PAGE_SIZE);
2913 SetPageUptodate(page);
2915 ClearPageUptodate(page);
2921 if (unlikely(!uptodate)) {
2923 endio_readpage_release_extent(tree,
2929 endio_readpage_release_extent(tree, start,
2930 end - start + 1, 0);
2931 } else if (!extent_len) {
2932 extent_start = start;
2933 extent_len = end + 1 - start;
2934 } else if (extent_start + extent_len == start) {
2935 extent_len += end + 1 - start;
2937 endio_readpage_release_extent(tree, extent_start,
2938 extent_len, uptodate);
2939 extent_start = start;
2940 extent_len = end + 1 - start;
2945 endio_readpage_release_extent(tree, extent_start, extent_len,
2947 btrfs_io_bio_free_csum(io_bio);
2952 * Initialize the members up to but not including 'bio'. Use after allocating a
2953 * new bio by bio_alloc_bioset as it does not initialize the bytes outside of
2954 * 'bio' because use of __GFP_ZERO is not supported.
2956 static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio)
2958 memset(btrfs_bio, 0, offsetof(struct btrfs_io_bio, bio));
2962 * The following helpers allocate a bio. As it's backed by a bioset, it'll
2963 * never fail. We're returning a bio right now but you can call btrfs_io_bio
2964 * for the appropriate container_of magic
2966 struct bio *btrfs_bio_alloc(u64 first_byte)
2970 bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, &btrfs_bioset);
2971 bio->bi_iter.bi_sector = first_byte >> 9;
2972 btrfs_io_bio_init(btrfs_io_bio(bio));
2976 struct bio *btrfs_bio_clone(struct bio *bio)
2978 struct btrfs_io_bio *btrfs_bio;
2981 /* Bio allocation backed by a bioset does not fail */
2982 new = bio_clone_fast(bio, GFP_NOFS, &btrfs_bioset);
2983 btrfs_bio = btrfs_io_bio(new);
2984 btrfs_io_bio_init(btrfs_bio);
2985 btrfs_bio->iter = bio->bi_iter;
2989 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs)
2993 /* Bio allocation backed by a bioset does not fail */
2994 bio = bio_alloc_bioset(GFP_NOFS, nr_iovecs, &btrfs_bioset);
2995 btrfs_io_bio_init(btrfs_io_bio(bio));
2999 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
3002 struct btrfs_io_bio *btrfs_bio;
3004 /* this will never fail when it's backed by a bioset */
3005 bio = bio_clone_fast(orig, GFP_NOFS, &btrfs_bioset);
3008 btrfs_bio = btrfs_io_bio(bio);
3009 btrfs_io_bio_init(btrfs_bio);
3011 bio_trim(bio, offset >> 9, size >> 9);
3012 btrfs_bio->iter = bio->bi_iter;
3017 * @opf: bio REQ_OP_* and REQ_* flags as one value
3018 * @wbc: optional writeback control for io accounting
3019 * @page: page to add to the bio
3020 * @pg_offset: offset of the new bio or to check whether we are adding
3021 * a contiguous page to the previous one
3022 * @size: portion of page that we want to write
3023 * @offset: starting offset in the page
3024 * @bio_ret: must be valid pointer, newly allocated bio will be stored there
3025 * @end_io_func: end_io callback for new bio
3026 * @mirror_num: desired mirror to read/write
3027 * @prev_bio_flags: flags of previous bio to see if we can merge the current one
3028 * @bio_flags: flags of the current bio to see if we can merge them
3030 static int submit_extent_page(unsigned int opf,
3031 struct writeback_control *wbc,
3032 struct page *page, u64 offset,
3033 size_t size, unsigned long pg_offset,
3034 struct bio **bio_ret,
3035 bio_end_io_t end_io_func,
3037 unsigned long prev_bio_flags,
3038 unsigned long bio_flags,
3039 bool force_bio_submit)
3043 size_t page_size = min_t(size_t, size, PAGE_SIZE);
3044 sector_t sector = offset >> 9;
3045 struct extent_io_tree *tree = &BTRFS_I(page->mapping->host)->io_tree;
3051 bool can_merge = true;
3054 if (prev_bio_flags & EXTENT_BIO_COMPRESSED)
3055 contig = bio->bi_iter.bi_sector == sector;
3057 contig = bio_end_sector(bio) == sector;
3060 if (btrfs_bio_fits_in_stripe(page, page_size, bio, bio_flags))
3063 if (prev_bio_flags != bio_flags || !contig || !can_merge ||
3065 bio_add_page(bio, page, page_size, pg_offset) < page_size) {
3066 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
3074 wbc_account_cgroup_owner(wbc, page, page_size);
3079 bio = btrfs_bio_alloc(offset);
3080 bio_add_page(bio, page, page_size, pg_offset);
3081 bio->bi_end_io = end_io_func;
3082 bio->bi_private = tree;
3083 bio->bi_write_hint = page->mapping->host->i_write_hint;
3086 struct block_device *bdev;
3088 bdev = BTRFS_I(page->mapping->host)->root->fs_info->fs_devices->latest_bdev;
3089 bio_set_dev(bio, bdev);
3090 wbc_init_bio(wbc, bio);
3091 wbc_account_cgroup_owner(wbc, page, page_size);
3099 static void attach_extent_buffer_page(struct extent_buffer *eb,
3102 if (!PagePrivate(page)) {
3103 SetPagePrivate(page);
3105 set_page_private(page, (unsigned long)eb);
3107 WARN_ON(page->private != (unsigned long)eb);
3111 void set_page_extent_mapped(struct page *page)
3113 if (!PagePrivate(page)) {
3114 SetPagePrivate(page);
3116 set_page_private(page, EXTENT_PAGE_PRIVATE);
3120 static struct extent_map *
3121 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
3122 u64 start, u64 len, get_extent_t *get_extent,
3123 struct extent_map **em_cached)
3125 struct extent_map *em;
3127 if (em_cached && *em_cached) {
3129 if (extent_map_in_tree(em) && start >= em->start &&
3130 start < extent_map_end(em)) {
3131 refcount_inc(&em->refs);
3135 free_extent_map(em);
3139 em = get_extent(BTRFS_I(inode), page, pg_offset, start, len);
3140 if (em_cached && !IS_ERR_OR_NULL(em)) {
3142 refcount_inc(&em->refs);
3148 * basic readpage implementation. Locked extent state structs are inserted
3149 * into the tree that are removed when the IO is done (by the end_io
3151 * XXX JDM: This needs looking at to ensure proper page locking
3152 * return 0 on success, otherwise return error
3154 static int __do_readpage(struct page *page,
3155 get_extent_t *get_extent,
3156 struct extent_map **em_cached,
3157 struct bio **bio, int mirror_num,
3158 unsigned long *bio_flags, unsigned int read_flags,
3161 struct inode *inode = page->mapping->host;
3162 u64 start = page_offset(page);
3163 const u64 end = start + PAGE_SIZE - 1;
3166 u64 last_byte = i_size_read(inode);
3169 struct extent_map *em;
3172 size_t pg_offset = 0;
3174 size_t disk_io_size;
3175 size_t blocksize = inode->i_sb->s_blocksize;
3176 unsigned long this_bio_flag = 0;
3177 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
3179 set_page_extent_mapped(page);
3181 if (!PageUptodate(page)) {
3182 if (cleancache_get_page(page) == 0) {
3183 BUG_ON(blocksize != PAGE_SIZE);
3184 unlock_extent(tree, start, end);
3189 if (page->index == last_byte >> PAGE_SHIFT) {
3191 size_t zero_offset = offset_in_page(last_byte);
3194 iosize = PAGE_SIZE - zero_offset;
3195 userpage = kmap_atomic(page);
3196 memset(userpage + zero_offset, 0, iosize);
3197 flush_dcache_page(page);
3198 kunmap_atomic(userpage);
3201 while (cur <= end) {
3202 bool force_bio_submit = false;
3205 if (cur >= last_byte) {
3207 struct extent_state *cached = NULL;
3209 iosize = PAGE_SIZE - pg_offset;
3210 userpage = kmap_atomic(page);
3211 memset(userpage + pg_offset, 0, iosize);
3212 flush_dcache_page(page);
3213 kunmap_atomic(userpage);
3214 set_extent_uptodate(tree, cur, cur + iosize - 1,
3216 unlock_extent_cached(tree, cur,
3217 cur + iosize - 1, &cached);
3220 em = __get_extent_map(inode, page, pg_offset, cur,
3221 end - cur + 1, get_extent, em_cached);
3222 if (IS_ERR_OR_NULL(em)) {
3224 unlock_extent(tree, cur, end);
3227 extent_offset = cur - em->start;
3228 BUG_ON(extent_map_end(em) <= cur);
3231 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
3232 this_bio_flag |= EXTENT_BIO_COMPRESSED;
3233 extent_set_compress_type(&this_bio_flag,
3237 iosize = min(extent_map_end(em) - cur, end - cur + 1);
3238 cur_end = min(extent_map_end(em) - 1, end);
3239 iosize = ALIGN(iosize, blocksize);
3240 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
3241 disk_io_size = em->block_len;
3242 offset = em->block_start;
3244 offset = em->block_start + extent_offset;
3245 disk_io_size = iosize;
3247 block_start = em->block_start;
3248 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
3249 block_start = EXTENT_MAP_HOLE;
3252 * If we have a file range that points to a compressed extent
3253 * and it's followed by a consecutive file range that points to
3254 * to the same compressed extent (possibly with a different
3255 * offset and/or length, so it either points to the whole extent
3256 * or only part of it), we must make sure we do not submit a
3257 * single bio to populate the pages for the 2 ranges because
3258 * this makes the compressed extent read zero out the pages
3259 * belonging to the 2nd range. Imagine the following scenario:
3262 * [0 - 8K] [8K - 24K]
3265 * points to extent X, points to extent X,
3266 * offset 4K, length of 8K offset 0, length 16K
3268 * [extent X, compressed length = 4K uncompressed length = 16K]
3270 * If the bio to read the compressed extent covers both ranges,
3271 * it will decompress extent X into the pages belonging to the
3272 * first range and then it will stop, zeroing out the remaining
3273 * pages that belong to the other range that points to extent X.
3274 * So here we make sure we submit 2 bios, one for the first
3275 * range and another one for the third range. Both will target
3276 * the same physical extent from disk, but we can't currently
3277 * make the compressed bio endio callback populate the pages
3278 * for both ranges because each compressed bio is tightly
3279 * coupled with a single extent map, and each range can have
3280 * an extent map with a different offset value relative to the
3281 * uncompressed data of our extent and different lengths. This
3282 * is a corner case so we prioritize correctness over
3283 * non-optimal behavior (submitting 2 bios for the same extent).
3285 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3286 prev_em_start && *prev_em_start != (u64)-1 &&
3287 *prev_em_start != em->start)
3288 force_bio_submit = true;
3291 *prev_em_start = em->start;
3293 free_extent_map(em);
3296 /* we've found a hole, just zero and go on */
3297 if (block_start == EXTENT_MAP_HOLE) {
3299 struct extent_state *cached = NULL;
3301 userpage = kmap_atomic(page);
3302 memset(userpage + pg_offset, 0, iosize);
3303 flush_dcache_page(page);
3304 kunmap_atomic(userpage);
3306 set_extent_uptodate(tree, cur, cur + iosize - 1,
3308 unlock_extent_cached(tree, cur,
3309 cur + iosize - 1, &cached);
3311 pg_offset += iosize;
3314 /* the get_extent function already copied into the page */
3315 if (test_range_bit(tree, cur, cur_end,
3316 EXTENT_UPTODATE, 1, NULL)) {
3317 check_page_uptodate(tree, page);
3318 unlock_extent(tree, cur, cur + iosize - 1);
3320 pg_offset += iosize;
3323 /* we have an inline extent but it didn't get marked up
3324 * to date. Error out
3326 if (block_start == EXTENT_MAP_INLINE) {
3328 unlock_extent(tree, cur, cur + iosize - 1);
3330 pg_offset += iosize;
3334 ret = submit_extent_page(REQ_OP_READ | read_flags, NULL,
3335 page, offset, disk_io_size,
3337 end_bio_extent_readpage, mirror_num,
3343 *bio_flags = this_bio_flag;
3346 unlock_extent(tree, cur, cur + iosize - 1);
3350 pg_offset += iosize;
3354 if (!PageError(page))
3355 SetPageUptodate(page);
3361 static inline void contiguous_readpages(struct page *pages[], int nr_pages,
3363 struct extent_map **em_cached,
3365 unsigned long *bio_flags,
3368 struct btrfs_inode *inode = BTRFS_I(pages[0]->mapping->host);
3371 btrfs_lock_and_flush_ordered_range(inode, start, end, NULL);
3373 for (index = 0; index < nr_pages; index++) {
3374 __do_readpage(pages[index], btrfs_get_extent, em_cached,
3375 bio, 0, bio_flags, REQ_RAHEAD, prev_em_start);
3376 put_page(pages[index]);
3380 static int __extent_read_full_page(struct page *page,
3381 get_extent_t *get_extent,
3382 struct bio **bio, int mirror_num,
3383 unsigned long *bio_flags,
3384 unsigned int read_flags)
3386 struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
3387 u64 start = page_offset(page);
3388 u64 end = start + PAGE_SIZE - 1;
3391 btrfs_lock_and_flush_ordered_range(inode, start, end, NULL);
3393 ret = __do_readpage(page, get_extent, NULL, bio, mirror_num,
3394 bio_flags, read_flags, NULL);
3398 int extent_read_full_page(struct page *page, get_extent_t *get_extent,
3401 struct bio *bio = NULL;
3402 unsigned long bio_flags = 0;
3405 ret = __extent_read_full_page(page, get_extent, &bio, mirror_num,
3408 ret = submit_one_bio(bio, mirror_num, bio_flags);
3412 static void update_nr_written(struct writeback_control *wbc,
3413 unsigned long nr_written)
3415 wbc->nr_to_write -= nr_written;
3419 * helper for __extent_writepage, doing all of the delayed allocation setup.
3421 * This returns 1 if btrfs_run_delalloc_range function did all the work required
3422 * to write the page (copy into inline extent). In this case the IO has
3423 * been started and the page is already unlocked.
3425 * This returns 0 if all went well (page still locked)
3426 * This returns < 0 if there were errors (page still locked)
3428 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3429 struct page *page, struct writeback_control *wbc,
3430 u64 delalloc_start, unsigned long *nr_written)
3432 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3434 u64 delalloc_to_write = 0;
3435 u64 delalloc_end = 0;
3437 int page_started = 0;
3440 while (delalloc_end < page_end) {
3441 found = find_lock_delalloc_range(inode, page,
3445 delalloc_start = delalloc_end + 1;
3448 ret = btrfs_run_delalloc_range(inode, page, delalloc_start,
3449 delalloc_end, &page_started, nr_written, wbc);
3453 * btrfs_run_delalloc_range should return < 0 for error
3454 * but just in case, we use > 0 here meaning the IO is
3455 * started, so we don't want to return > 0 unless
3456 * things are going well.
3458 ret = ret < 0 ? ret : -EIO;
3462 * delalloc_end is already one less than the total length, so
3463 * we don't subtract one from PAGE_SIZE
3465 delalloc_to_write += (delalloc_end - delalloc_start +
3466 PAGE_SIZE) >> PAGE_SHIFT;
3467 delalloc_start = delalloc_end + 1;
3469 if (wbc->nr_to_write < delalloc_to_write) {
3472 if (delalloc_to_write < thresh * 2)
3473 thresh = delalloc_to_write;
3474 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3478 /* did the fill delalloc function already unlock and start
3483 * we've unlocked the page, so we can't update
3484 * the mapping's writeback index, just update
3487 wbc->nr_to_write -= *nr_written;
3498 * helper for __extent_writepage. This calls the writepage start hooks,
3499 * and does the loop to map the page into extents and bios.
3501 * We return 1 if the IO is started and the page is unlocked,
3502 * 0 if all went well (page still locked)
3503 * < 0 if there were errors (page still locked)
3505 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3507 struct writeback_control *wbc,
3508 struct extent_page_data *epd,
3510 unsigned long nr_written,
3513 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
3514 u64 start = page_offset(page);
3515 u64 page_end = start + PAGE_SIZE - 1;
3521 struct extent_map *em;
3522 size_t pg_offset = 0;
3526 const unsigned int write_flags = wbc_to_write_flags(wbc);
3529 ret = btrfs_writepage_cow_fixup(page, start, page_end);
3531 /* Fixup worker will requeue */
3532 redirty_page_for_writepage(wbc, page);
3533 update_nr_written(wbc, nr_written);
3539 * we don't want to touch the inode after unlocking the page,
3540 * so we update the mapping writeback index now
3542 update_nr_written(wbc, nr_written + 1);
3545 blocksize = inode->i_sb->s_blocksize;
3547 while (cur <= end) {
3551 if (cur >= i_size) {
3552 btrfs_writepage_endio_finish_ordered(page, cur,
3556 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur,
3558 if (IS_ERR_OR_NULL(em)) {
3560 ret = PTR_ERR_OR_ZERO(em);
3564 extent_offset = cur - em->start;
3565 em_end = extent_map_end(em);
3566 BUG_ON(em_end <= cur);
3568 iosize = min(em_end - cur, end - cur + 1);
3569 iosize = ALIGN(iosize, blocksize);
3570 offset = em->block_start + extent_offset;
3571 block_start = em->block_start;
3572 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3573 free_extent_map(em);
3577 * compressed and inline extents are written through other
3580 if (compressed || block_start == EXTENT_MAP_HOLE ||
3581 block_start == EXTENT_MAP_INLINE) {
3585 btrfs_writepage_endio_finish_ordered(page, cur,
3586 cur + iosize - 1, 1);
3588 pg_offset += iosize;
3592 btrfs_set_range_writeback(tree, cur, cur + iosize - 1);
3593 if (!PageWriteback(page)) {
3594 btrfs_err(BTRFS_I(inode)->root->fs_info,
3595 "page %lu not writeback, cur %llu end %llu",
3596 page->index, cur, end);
3599 ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
3600 page, offset, iosize, pg_offset,
3602 end_bio_extent_writepage,
3606 if (PageWriteback(page))
3607 end_page_writeback(page);
3611 pg_offset += iosize;
3619 * the writepage semantics are similar to regular writepage. extent
3620 * records are inserted to lock ranges in the tree, and as dirty areas
3621 * are found, they are marked writeback. Then the lock bits are removed
3622 * and the end_io handler clears the writeback ranges
3624 * Return 0 if everything goes well.
3625 * Return <0 for error.
3627 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3628 struct extent_page_data *epd)
3630 struct inode *inode = page->mapping->host;
3631 u64 start = page_offset(page);
3632 u64 page_end = start + PAGE_SIZE - 1;
3636 loff_t i_size = i_size_read(inode);
3637 unsigned long end_index = i_size >> PAGE_SHIFT;
3638 unsigned long nr_written = 0;
3640 trace___extent_writepage(page, inode, wbc);
3642 WARN_ON(!PageLocked(page));
3644 ClearPageError(page);
3646 pg_offset = offset_in_page(i_size);
3647 if (page->index > end_index ||
3648 (page->index == end_index && !pg_offset)) {
3649 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3654 if (page->index == end_index) {
3657 userpage = kmap_atomic(page);
3658 memset(userpage + pg_offset, 0,
3659 PAGE_SIZE - pg_offset);
3660 kunmap_atomic(userpage);
3661 flush_dcache_page(page);
3664 set_page_extent_mapped(page);
3666 if (!epd->extent_locked) {
3667 ret = writepage_delalloc(inode, page, wbc, start, &nr_written);
3674 ret = __extent_writepage_io(inode, page, wbc, epd,
3675 i_size, nr_written, &nr);
3681 /* make sure the mapping tag for page dirty gets cleared */
3682 set_page_writeback(page);
3683 end_page_writeback(page);
3685 if (PageError(page)) {
3686 ret = ret < 0 ? ret : -EIO;
3687 end_extent_writepage(page, ret, start, page_end);
3694 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3696 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3697 TASK_UNINTERRUPTIBLE);
3700 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3702 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3703 smp_mb__after_atomic();
3704 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3708 * Lock eb pages and flush the bio if we can't the locks
3710 * Return 0 if nothing went wrong
3711 * Return >0 is same as 0, except bio is not submitted
3712 * Return <0 if something went wrong, no page is locked
3714 static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb,
3715 struct extent_page_data *epd)
3717 struct btrfs_fs_info *fs_info = eb->fs_info;
3718 int i, num_pages, failed_page_nr;
3722 if (!btrfs_try_tree_write_lock(eb)) {
3723 ret = flush_write_bio(epd);
3727 btrfs_tree_lock(eb);
3730 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3731 btrfs_tree_unlock(eb);
3735 ret = flush_write_bio(epd);
3741 wait_on_extent_buffer_writeback(eb);
3742 btrfs_tree_lock(eb);
3743 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3745 btrfs_tree_unlock(eb);
3750 * We need to do this to prevent races in people who check if the eb is
3751 * under IO since we can end up having no IO bits set for a short period
3754 spin_lock(&eb->refs_lock);
3755 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3756 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3757 spin_unlock(&eb->refs_lock);
3758 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3759 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
3761 fs_info->dirty_metadata_batch);
3764 spin_unlock(&eb->refs_lock);
3767 btrfs_tree_unlock(eb);
3772 num_pages = num_extent_pages(eb);
3773 for (i = 0; i < num_pages; i++) {
3774 struct page *p = eb->pages[i];
3776 if (!trylock_page(p)) {
3780 err = flush_write_bio(epd);
3794 /* Unlock already locked pages */
3795 for (i = 0; i < failed_page_nr; i++)
3796 unlock_page(eb->pages[i]);
3798 * Clear EXTENT_BUFFER_WRITEBACK and wake up anyone waiting on it.
3799 * Also set back EXTENT_BUFFER_DIRTY so future attempts to this eb can
3800 * be made and undo everything done before.
3802 btrfs_tree_lock(eb);
3803 spin_lock(&eb->refs_lock);
3804 set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3805 end_extent_buffer_writeback(eb);
3806 spin_unlock(&eb->refs_lock);
3807 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, eb->len,
3808 fs_info->dirty_metadata_batch);
3809 btrfs_clear_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3810 btrfs_tree_unlock(eb);
3814 static void set_btree_ioerr(struct page *page)
3816 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3817 struct btrfs_fs_info *fs_info;
3820 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3824 * If we error out, we should add back the dirty_metadata_bytes
3825 * to make it consistent.
3827 fs_info = eb->fs_info;
3828 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
3829 eb->len, fs_info->dirty_metadata_batch);
3832 * If writeback for a btree extent that doesn't belong to a log tree
3833 * failed, increment the counter transaction->eb_write_errors.
3834 * We do this because while the transaction is running and before it's
3835 * committing (when we call filemap_fdata[write|wait]_range against
3836 * the btree inode), we might have
3837 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3838 * returns an error or an error happens during writeback, when we're
3839 * committing the transaction we wouldn't know about it, since the pages
3840 * can be no longer dirty nor marked anymore for writeback (if a
3841 * subsequent modification to the extent buffer didn't happen before the
3842 * transaction commit), which makes filemap_fdata[write|wait]_range not
3843 * able to find the pages tagged with SetPageError at transaction
3844 * commit time. So if this happens we must abort the transaction,
3845 * otherwise we commit a super block with btree roots that point to
3846 * btree nodes/leafs whose content on disk is invalid - either garbage
3847 * or the content of some node/leaf from a past generation that got
3848 * cowed or deleted and is no longer valid.
3850 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3851 * not be enough - we need to distinguish between log tree extents vs
3852 * non-log tree extents, and the next filemap_fdatawait_range() call
3853 * will catch and clear such errors in the mapping - and that call might
3854 * be from a log sync and not from a transaction commit. Also, checking
3855 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3856 * not done and would not be reliable - the eb might have been released
3857 * from memory and reading it back again means that flag would not be
3858 * set (since it's a runtime flag, not persisted on disk).
3860 * Using the flags below in the btree inode also makes us achieve the
3861 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3862 * writeback for all dirty pages and before filemap_fdatawait_range()
3863 * is called, the writeback for all dirty pages had already finished
3864 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3865 * filemap_fdatawait_range() would return success, as it could not know
3866 * that writeback errors happened (the pages were no longer tagged for
3869 switch (eb->log_index) {
3871 set_bit(BTRFS_FS_BTREE_ERR, &eb->fs_info->flags);
3874 set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags);
3877 set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags);
3880 BUG(); /* unexpected, logic error */
3884 static void end_bio_extent_buffer_writepage(struct bio *bio)
3886 struct bio_vec *bvec;
3887 struct extent_buffer *eb;
3889 struct bvec_iter_all iter_all;
3891 ASSERT(!bio_flagged(bio, BIO_CLONED));
3892 bio_for_each_segment_all(bvec, bio, iter_all) {
3893 struct page *page = bvec->bv_page;
3895 eb = (struct extent_buffer *)page->private;
3897 done = atomic_dec_and_test(&eb->io_pages);
3899 if (bio->bi_status ||
3900 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3901 ClearPageUptodate(page);
3902 set_btree_ioerr(page);
3905 end_page_writeback(page);
3910 end_extent_buffer_writeback(eb);
3916 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3917 struct writeback_control *wbc,
3918 struct extent_page_data *epd)
3920 u64 offset = eb->start;
3923 unsigned long start, end;
3924 unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META;
3927 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3928 num_pages = num_extent_pages(eb);
3929 atomic_set(&eb->io_pages, num_pages);
3931 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3932 nritems = btrfs_header_nritems(eb);
3933 if (btrfs_header_level(eb) > 0) {
3934 end = btrfs_node_key_ptr_offset(nritems);
3936 memzero_extent_buffer(eb, end, eb->len - end);
3940 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3942 start = btrfs_item_nr_offset(nritems);
3943 end = BTRFS_LEAF_DATA_OFFSET + leaf_data_end(eb);
3944 memzero_extent_buffer(eb, start, end - start);
3947 for (i = 0; i < num_pages; i++) {
3948 struct page *p = eb->pages[i];
3950 clear_page_dirty_for_io(p);
3951 set_page_writeback(p);
3952 ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
3953 p, offset, PAGE_SIZE, 0,
3955 end_bio_extent_buffer_writepage,
3959 if (PageWriteback(p))
3960 end_page_writeback(p);
3961 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3962 end_extent_buffer_writeback(eb);
3966 offset += PAGE_SIZE;
3967 update_nr_written(wbc, 1);
3971 if (unlikely(ret)) {
3972 for (; i < num_pages; i++) {
3973 struct page *p = eb->pages[i];
3974 clear_page_dirty_for_io(p);
3982 int btree_write_cache_pages(struct address_space *mapping,
3983 struct writeback_control *wbc)
3985 struct extent_buffer *eb, *prev_eb = NULL;
3986 struct extent_page_data epd = {
3989 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3991 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3994 int nr_to_write_done = 0;
3995 struct pagevec pvec;
3998 pgoff_t end; /* Inclusive */
4002 pagevec_init(&pvec);
4003 if (wbc->range_cyclic) {
4004 index = mapping->writeback_index; /* Start from prev offset */
4007 * Start from the beginning does not need to cycle over the
4008 * range, mark it as scanned.
4010 scanned = (index == 0);
4012 index = wbc->range_start >> PAGE_SHIFT;
4013 end = wbc->range_end >> PAGE_SHIFT;
4016 if (wbc->sync_mode == WB_SYNC_ALL)
4017 tag = PAGECACHE_TAG_TOWRITE;
4019 tag = PAGECACHE_TAG_DIRTY;
4021 if (wbc->sync_mode == WB_SYNC_ALL)
4022 tag_pages_for_writeback(mapping, index, end);
4023 while (!done && !nr_to_write_done && (index <= end) &&
4024 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
4028 for (i = 0; i < nr_pages; i++) {
4029 struct page *page = pvec.pages[i];
4031 if (!PagePrivate(page))
4034 spin_lock(&mapping->private_lock);
4035 if (!PagePrivate(page)) {
4036 spin_unlock(&mapping->private_lock);
4040 eb = (struct extent_buffer *)page->private;
4043 * Shouldn't happen and normally this would be a BUG_ON
4044 * but no sense in crashing the users box for something
4045 * we can survive anyway.
4048 spin_unlock(&mapping->private_lock);
4052 if (eb == prev_eb) {
4053 spin_unlock(&mapping->private_lock);
4057 ret = atomic_inc_not_zero(&eb->refs);
4058 spin_unlock(&mapping->private_lock);
4063 ret = lock_extent_buffer_for_io(eb, &epd);
4065 free_extent_buffer(eb);
4067 } else if (ret < 0) {
4069 free_extent_buffer(eb);
4073 ret = write_one_eb(eb, wbc, &epd);
4076 free_extent_buffer(eb);
4079 free_extent_buffer(eb);
4082 * the filesystem may choose to bump up nr_to_write.
4083 * We have to make sure to honor the new nr_to_write
4086 nr_to_write_done = wbc->nr_to_write <= 0;
4088 pagevec_release(&pvec);
4091 if (!scanned && !done) {
4093 * We hit the last page and there is more work to be done: wrap
4094 * back to the start of the file
4102 end_write_bio(&epd, ret);
4106 * If something went wrong, don't allow any metadata write bio to be
4109 * This would prevent use-after-free if we had dirty pages not
4110 * cleaned up, which can still happen by fuzzed images.
4113 * Allowing existing tree block to be allocated for other trees.
4115 * - Log tree operations
4116 * Exiting tree blocks get allocated to log tree, bumps its
4117 * generation, then get cleaned in tree re-balance.
4118 * Such tree block will not be written back, since it's clean,
4119 * thus no WRITTEN flag set.
4120 * And after log writes back, this tree block is not traced by
4121 * any dirty extent_io_tree.
4123 * - Offending tree block gets re-dirtied from its original owner
4124 * Since it has bumped generation, no WRITTEN flag, it can be
4125 * reused without COWing. This tree block will not be traced
4126 * by btrfs_transaction::dirty_pages.
4128 * Now such dirty tree block will not be cleaned by any dirty
4129 * extent io tree. Thus we don't want to submit such wild eb
4130 * if the fs already has error.
4132 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
4133 ret = flush_write_bio(&epd);
4136 end_write_bio(&epd, ret);
4142 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
4143 * @mapping: address space structure to write
4144 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
4145 * @data: data passed to __extent_writepage function
4147 * If a page is already under I/O, write_cache_pages() skips it, even
4148 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
4149 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
4150 * and msync() need to guarantee that all the data which was dirty at the time
4151 * the call was made get new I/O started against them. If wbc->sync_mode is
4152 * WB_SYNC_ALL then we were called for data integrity and we must wait for
4153 * existing IO to complete.
4155 static int extent_write_cache_pages(struct address_space *mapping,
4156 struct writeback_control *wbc,
4157 struct extent_page_data *epd)
4159 struct inode *inode = mapping->host;
4162 int nr_to_write_done = 0;
4163 struct pagevec pvec;
4166 pgoff_t end; /* Inclusive */
4168 int range_whole = 0;
4173 * We have to hold onto the inode so that ordered extents can do their
4174 * work when the IO finishes. The alternative to this is failing to add
4175 * an ordered extent if the igrab() fails there and that is a huge pain
4176 * to deal with, so instead just hold onto the inode throughout the
4177 * writepages operation. If it fails here we are freeing up the inode
4178 * anyway and we'd rather not waste our time writing out stuff that is
4179 * going to be truncated anyway.
4184 pagevec_init(&pvec);
4185 if (wbc->range_cyclic) {
4186 index = mapping->writeback_index; /* Start from prev offset */
4189 * Start from the beginning does not need to cycle over the
4190 * range, mark it as scanned.
4192 scanned = (index == 0);
4194 index = wbc->range_start >> PAGE_SHIFT;
4195 end = wbc->range_end >> PAGE_SHIFT;
4196 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
4202 * We do the tagged writepage as long as the snapshot flush bit is set
4203 * and we are the first one who do the filemap_flush() on this inode.
4205 * The nr_to_write == LONG_MAX is needed to make sure other flushers do
4206 * not race in and drop the bit.
4208 if (range_whole && wbc->nr_to_write == LONG_MAX &&
4209 test_and_clear_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
4210 &BTRFS_I(inode)->runtime_flags))
4211 wbc->tagged_writepages = 1;
4213 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
4214 tag = PAGECACHE_TAG_TOWRITE;
4216 tag = PAGECACHE_TAG_DIRTY;
4218 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
4219 tag_pages_for_writeback(mapping, index, end);
4221 while (!done && !nr_to_write_done && (index <= end) &&
4222 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping,
4223 &index, end, tag))) {
4226 for (i = 0; i < nr_pages; i++) {
4227 struct page *page = pvec.pages[i];
4229 done_index = page->index + 1;
4231 * At this point we hold neither the i_pages lock nor
4232 * the page lock: the page may be truncated or
4233 * invalidated (changing page->mapping to NULL),
4234 * or even swizzled back from swapper_space to
4235 * tmpfs file mapping
4237 if (!trylock_page(page)) {
4238 ret = flush_write_bio(epd);
4243 if (unlikely(page->mapping != mapping)) {
4248 if (wbc->sync_mode != WB_SYNC_NONE) {
4249 if (PageWriteback(page)) {
4250 ret = flush_write_bio(epd);
4253 wait_on_page_writeback(page);
4256 if (PageWriteback(page) ||
4257 !clear_page_dirty_for_io(page)) {
4262 ret = __extent_writepage(page, wbc, epd);
4269 * the filesystem may choose to bump up nr_to_write.
4270 * We have to make sure to honor the new nr_to_write
4273 nr_to_write_done = wbc->nr_to_write <= 0;
4275 pagevec_release(&pvec);
4278 if (!scanned && !done) {
4280 * We hit the last page and there is more work to be done: wrap
4281 * back to the start of the file
4287 * If we're looping we could run into a page that is locked by a
4288 * writer and that writer could be waiting on writeback for a
4289 * page in our current bio, and thus deadlock, so flush the
4292 ret = flush_write_bio(epd);
4297 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4298 mapping->writeback_index = done_index;
4300 btrfs_add_delayed_iput(inode);
4304 int extent_write_full_page(struct page *page, struct writeback_control *wbc)
4307 struct extent_page_data epd = {
4310 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4313 ret = __extent_writepage(page, wbc, &epd);
4316 end_write_bio(&epd, ret);
4320 ret = flush_write_bio(&epd);
4325 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
4329 struct address_space *mapping = inode->i_mapping;
4331 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4334 struct extent_page_data epd = {
4337 .sync_io = mode == WB_SYNC_ALL,
4339 struct writeback_control wbc_writepages = {
4341 .nr_to_write = nr_pages * 2,
4342 .range_start = start,
4343 .range_end = end + 1,
4344 /* We're called from an async helper function */
4345 .punt_to_cgroup = 1,
4346 .no_cgroup_owner = 1,
4349 wbc_attach_fdatawrite_inode(&wbc_writepages, inode);
4350 while (start <= end) {
4351 page = find_get_page(mapping, start >> PAGE_SHIFT);
4352 if (clear_page_dirty_for_io(page))
4353 ret = __extent_writepage(page, &wbc_writepages, &epd);
4355 btrfs_writepage_endio_finish_ordered(page, start,
4356 start + PAGE_SIZE - 1, 1);
4365 ret = flush_write_bio(&epd);
4367 end_write_bio(&epd, ret);
4369 wbc_detach_inode(&wbc_writepages);
4373 int extent_writepages(struct address_space *mapping,
4374 struct writeback_control *wbc)
4377 struct extent_page_data epd = {
4380 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4383 ret = extent_write_cache_pages(mapping, wbc, &epd);
4386 end_write_bio(&epd, ret);
4389 ret = flush_write_bio(&epd);
4393 int extent_readpages(struct address_space *mapping, struct list_head *pages,
4396 struct bio *bio = NULL;
4397 unsigned long bio_flags = 0;
4398 struct page *pagepool[16];
4399 struct extent_map *em_cached = NULL;
4401 u64 prev_em_start = (u64)-1;
4403 while (!list_empty(pages)) {
4406 for (nr = 0; nr < ARRAY_SIZE(pagepool) && !list_empty(pages);) {
4407 struct page *page = lru_to_page(pages);
4409 prefetchw(&page->flags);
4410 list_del(&page->lru);
4411 if (add_to_page_cache_lru(page, mapping, page->index,
4412 readahead_gfp_mask(mapping))) {
4417 pagepool[nr++] = page;
4418 contig_end = page_offset(page) + PAGE_SIZE - 1;
4422 u64 contig_start = page_offset(pagepool[0]);
4424 ASSERT(contig_start + nr * PAGE_SIZE - 1 == contig_end);
4426 contiguous_readpages(pagepool, nr, contig_start,
4427 contig_end, &em_cached, &bio, &bio_flags,
4433 free_extent_map(em_cached);
4436 return submit_one_bio(bio, 0, bio_flags);
4441 * basic invalidatepage code, this waits on any locked or writeback
4442 * ranges corresponding to the page, and then deletes any extent state
4443 * records from the tree
4445 int extent_invalidatepage(struct extent_io_tree *tree,
4446 struct page *page, unsigned long offset)
4448 struct extent_state *cached_state = NULL;
4449 u64 start = page_offset(page);
4450 u64 end = start + PAGE_SIZE - 1;
4451 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4453 start += ALIGN(offset, blocksize);
4457 lock_extent_bits(tree, start, end, &cached_state);
4458 wait_on_page_writeback(page);
4459 clear_extent_bit(tree, start, end, EXTENT_LOCKED | EXTENT_DELALLOC |
4460 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state);
4465 * a helper for releasepage, this tests for areas of the page that
4466 * are locked or under IO and drops the related state bits if it is safe
4469 static int try_release_extent_state(struct extent_io_tree *tree,
4470 struct page *page, gfp_t mask)
4472 u64 start = page_offset(page);
4473 u64 end = start + PAGE_SIZE - 1;
4476 if (test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL)) {
4480 * at this point we can safely clear everything except the
4481 * locked bit and the nodatasum bit
4483 ret = __clear_extent_bit(tree, start, end,
4484 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4485 0, 0, NULL, mask, NULL);
4487 /* if clear_extent_bit failed for enomem reasons,
4488 * we can't allow the release to continue.
4499 * a helper for releasepage. As long as there are no locked extents
4500 * in the range corresponding to the page, both state records and extent
4501 * map records are removed
4503 int try_release_extent_mapping(struct page *page, gfp_t mask)
4505 struct extent_map *em;
4506 u64 start = page_offset(page);
4507 u64 end = start + PAGE_SIZE - 1;
4508 struct btrfs_inode *btrfs_inode = BTRFS_I(page->mapping->host);
4509 struct extent_io_tree *tree = &btrfs_inode->io_tree;
4510 struct extent_map_tree *map = &btrfs_inode->extent_tree;
4512 if (gfpflags_allow_blocking(mask) &&
4513 page->mapping->host->i_size > SZ_16M) {
4515 while (start <= end) {
4516 len = end - start + 1;
4517 write_lock(&map->lock);
4518 em = lookup_extent_mapping(map, start, len);
4520 write_unlock(&map->lock);
4523 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4524 em->start != start) {
4525 write_unlock(&map->lock);
4526 free_extent_map(em);
4529 if (!test_range_bit(tree, em->start,
4530 extent_map_end(em) - 1,
4531 EXTENT_LOCKED, 0, NULL)) {
4532 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4533 &btrfs_inode->runtime_flags);
4534 remove_extent_mapping(map, em);
4535 /* once for the rb tree */
4536 free_extent_map(em);
4538 start = extent_map_end(em);
4539 write_unlock(&map->lock);
4542 free_extent_map(em);
4545 return try_release_extent_state(tree, page, mask);
4549 * helper function for fiemap, which doesn't want to see any holes.
4550 * This maps until we find something past 'last'
4552 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4553 u64 offset, u64 last)
4555 u64 sectorsize = btrfs_inode_sectorsize(inode);
4556 struct extent_map *em;
4563 len = last - offset;
4566 len = ALIGN(len, sectorsize);
4567 em = btrfs_get_extent_fiemap(BTRFS_I(inode), offset, len);
4568 if (IS_ERR_OR_NULL(em))
4571 /* if this isn't a hole return it */
4572 if (em->block_start != EXTENT_MAP_HOLE)
4575 /* this is a hole, advance to the next extent */
4576 offset = extent_map_end(em);
4577 free_extent_map(em);
4585 * To cache previous fiemap extent
4587 * Will be used for merging fiemap extent
4589 struct fiemap_cache {
4598 * Helper to submit fiemap extent.
4600 * Will try to merge current fiemap extent specified by @offset, @phys,
4601 * @len and @flags with cached one.
4602 * And only when we fails to merge, cached one will be submitted as
4605 * Return value is the same as fiemap_fill_next_extent().
4607 static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
4608 struct fiemap_cache *cache,
4609 u64 offset, u64 phys, u64 len, u32 flags)
4617 * Sanity check, extent_fiemap() should have ensured that new
4618 * fiemap extent won't overlap with cached one.
4621 * NOTE: Physical address can overlap, due to compression
4623 if (cache->offset + cache->len > offset) {
4629 * Only merges fiemap extents if
4630 * 1) Their logical addresses are continuous
4632 * 2) Their physical addresses are continuous
4633 * So truly compressed (physical size smaller than logical size)
4634 * extents won't get merged with each other
4636 * 3) Share same flags except FIEMAP_EXTENT_LAST
4637 * So regular extent won't get merged with prealloc extent
4639 if (cache->offset + cache->len == offset &&
4640 cache->phys + cache->len == phys &&
4641 (cache->flags & ~FIEMAP_EXTENT_LAST) ==
4642 (flags & ~FIEMAP_EXTENT_LAST)) {
4644 cache->flags |= flags;
4645 goto try_submit_last;
4648 /* Not mergeable, need to submit cached one */
4649 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4650 cache->len, cache->flags);
4651 cache->cached = false;
4655 cache->cached = true;
4656 cache->offset = offset;
4659 cache->flags = flags;
4661 if (cache->flags & FIEMAP_EXTENT_LAST) {
4662 ret = fiemap_fill_next_extent(fieinfo, cache->offset,
4663 cache->phys, cache->len, cache->flags);
4664 cache->cached = false;
4670 * Emit last fiemap cache
4672 * The last fiemap cache may still be cached in the following case:
4674 * |<- Fiemap range ->|
4675 * |<------------ First extent ----------->|
4677 * In this case, the first extent range will be cached but not emitted.
4678 * So we must emit it before ending extent_fiemap().
4680 static int emit_last_fiemap_cache(struct fiemap_extent_info *fieinfo,
4681 struct fiemap_cache *cache)
4688 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4689 cache->len, cache->flags);
4690 cache->cached = false;
4696 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4697 __u64 start, __u64 len)
4701 u64 max = start + len;
4705 u64 last_for_get_extent = 0;
4707 u64 isize = i_size_read(inode);
4708 struct btrfs_key found_key;
4709 struct extent_map *em = NULL;
4710 struct extent_state *cached_state = NULL;
4711 struct btrfs_path *path;
4712 struct btrfs_root *root = BTRFS_I(inode)->root;
4713 struct fiemap_cache cache = { 0 };
4714 struct ulist *roots;
4715 struct ulist *tmp_ulist;
4724 path = btrfs_alloc_path();
4727 path->leave_spinning = 1;
4729 roots = ulist_alloc(GFP_KERNEL);
4730 tmp_ulist = ulist_alloc(GFP_KERNEL);
4731 if (!roots || !tmp_ulist) {
4733 goto out_free_ulist;
4736 start = round_down(start, btrfs_inode_sectorsize(inode));
4737 len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
4740 * lookup the last file extent. We're not using i_size here
4741 * because there might be preallocation past i_size
4743 ret = btrfs_lookup_file_extent(NULL, root, path,
4744 btrfs_ino(BTRFS_I(inode)), -1, 0);
4746 goto out_free_ulist;
4754 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4755 found_type = found_key.type;
4757 /* No extents, but there might be delalloc bits */
4758 if (found_key.objectid != btrfs_ino(BTRFS_I(inode)) ||
4759 found_type != BTRFS_EXTENT_DATA_KEY) {
4760 /* have to trust i_size as the end */
4762 last_for_get_extent = isize;
4765 * remember the start of the last extent. There are a
4766 * bunch of different factors that go into the length of the
4767 * extent, so its much less complex to remember where it started
4769 last = found_key.offset;
4770 last_for_get_extent = last + 1;
4772 btrfs_release_path(path);
4775 * we might have some extents allocated but more delalloc past those
4776 * extents. so, we trust isize unless the start of the last extent is
4781 last_for_get_extent = isize;
4784 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4787 em = get_extent_skip_holes(inode, start, last_for_get_extent);
4796 u64 offset_in_extent = 0;
4798 /* break if the extent we found is outside the range */
4799 if (em->start >= max || extent_map_end(em) < off)
4803 * get_extent may return an extent that starts before our
4804 * requested range. We have to make sure the ranges
4805 * we return to fiemap always move forward and don't
4806 * overlap, so adjust the offsets here
4808 em_start = max(em->start, off);
4811 * record the offset from the start of the extent
4812 * for adjusting the disk offset below. Only do this if the
4813 * extent isn't compressed since our in ram offset may be past
4814 * what we have actually allocated on disk.
4816 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4817 offset_in_extent = em_start - em->start;
4818 em_end = extent_map_end(em);
4819 em_len = em_end - em_start;
4821 if (em->block_start < EXTENT_MAP_LAST_BYTE)
4822 disko = em->block_start + offset_in_extent;
4827 * bump off for our next call to get_extent
4829 off = extent_map_end(em);
4833 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4835 flags |= FIEMAP_EXTENT_LAST;
4836 } else if (em->block_start == EXTENT_MAP_INLINE) {
4837 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4838 FIEMAP_EXTENT_NOT_ALIGNED);
4839 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4840 flags |= (FIEMAP_EXTENT_DELALLOC |
4841 FIEMAP_EXTENT_UNKNOWN);
4842 } else if (fieinfo->fi_extents_max) {
4843 u64 bytenr = em->block_start -
4844 (em->start - em->orig_start);
4847 * As btrfs supports shared space, this information
4848 * can be exported to userspace tools via
4849 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4850 * then we're just getting a count and we can skip the
4853 ret = btrfs_check_shared(root,
4854 btrfs_ino(BTRFS_I(inode)),
4855 bytenr, roots, tmp_ulist);
4859 flags |= FIEMAP_EXTENT_SHARED;
4862 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4863 flags |= FIEMAP_EXTENT_ENCODED;
4864 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4865 flags |= FIEMAP_EXTENT_UNWRITTEN;
4867 free_extent_map(em);
4869 if ((em_start >= last) || em_len == (u64)-1 ||
4870 (last == (u64)-1 && isize <= em_end)) {
4871 flags |= FIEMAP_EXTENT_LAST;
4875 /* now scan forward to see if this is really the last extent. */
4876 em = get_extent_skip_holes(inode, off, last_for_get_extent);
4882 flags |= FIEMAP_EXTENT_LAST;
4885 ret = emit_fiemap_extent(fieinfo, &cache, em_start, disko,
4895 ret = emit_last_fiemap_cache(fieinfo, &cache);
4896 free_extent_map(em);
4898 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4902 btrfs_free_path(path);
4904 ulist_free(tmp_ulist);
4908 static void __free_extent_buffer(struct extent_buffer *eb)
4910 kmem_cache_free(extent_buffer_cache, eb);
4913 int extent_buffer_under_io(const struct extent_buffer *eb)
4915 return (atomic_read(&eb->io_pages) ||
4916 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4917 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4921 * Release all pages attached to the extent buffer.
4923 static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb)
4927 int mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
4929 BUG_ON(extent_buffer_under_io(eb));
4931 num_pages = num_extent_pages(eb);
4932 for (i = 0; i < num_pages; i++) {
4933 struct page *page = eb->pages[i];
4938 spin_lock(&page->mapping->private_lock);
4940 * We do this since we'll remove the pages after we've
4941 * removed the eb from the radix tree, so we could race
4942 * and have this page now attached to the new eb. So
4943 * only clear page_private if it's still connected to
4946 if (PagePrivate(page) &&
4947 page->private == (unsigned long)eb) {
4948 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4949 BUG_ON(PageDirty(page));
4950 BUG_ON(PageWriteback(page));
4952 * We need to make sure we haven't be attached
4955 ClearPagePrivate(page);
4956 set_page_private(page, 0);
4957 /* One for the page private */
4962 spin_unlock(&page->mapping->private_lock);
4964 /* One for when we allocated the page */
4970 * Helper for releasing the extent buffer.
4972 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4974 btrfs_release_extent_buffer_pages(eb);
4975 btrfs_leak_debug_del(&eb->fs_info->eb_leak_lock, &eb->leak_list);
4976 __free_extent_buffer(eb);
4979 static struct extent_buffer *
4980 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4983 struct extent_buffer *eb = NULL;
4985 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4988 eb->fs_info = fs_info;
4990 rwlock_init(&eb->lock);
4991 atomic_set(&eb->blocking_readers, 0);
4992 eb->blocking_writers = 0;
4993 eb->lock_nested = false;
4994 init_waitqueue_head(&eb->write_lock_wq);
4995 init_waitqueue_head(&eb->read_lock_wq);
4997 btrfs_leak_debug_add(&fs_info->eb_leak_lock, &eb->leak_list,
4998 &fs_info->allocated_ebs);
5000 spin_lock_init(&eb->refs_lock);
5001 atomic_set(&eb->refs, 1);
5002 atomic_set(&eb->io_pages, 0);
5005 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
5007 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
5008 > MAX_INLINE_EXTENT_BUFFER_SIZE);
5009 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
5011 #ifdef CONFIG_BTRFS_DEBUG
5012 eb->spinning_writers = 0;
5013 atomic_set(&eb->spinning_readers, 0);
5014 atomic_set(&eb->read_locks, 0);
5015 eb->write_locks = 0;
5021 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src)
5025 struct extent_buffer *new;
5026 int num_pages = num_extent_pages(src);
5028 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
5032 for (i = 0; i < num_pages; i++) {
5033 p = alloc_page(GFP_NOFS);
5035 btrfs_release_extent_buffer(new);
5038 attach_extent_buffer_page(new, p);
5039 WARN_ON(PageDirty(p));
5042 copy_page(page_address(p), page_address(src->pages[i]));
5045 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
5046 set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags);
5051 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
5052 u64 start, unsigned long len)
5054 struct extent_buffer *eb;
5058 eb = __alloc_extent_buffer(fs_info, start, len);
5062 num_pages = num_extent_pages(eb);
5063 for (i = 0; i < num_pages; i++) {
5064 eb->pages[i] = alloc_page(GFP_NOFS);
5068 set_extent_buffer_uptodate(eb);
5069 btrfs_set_header_nritems(eb, 0);
5070 set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
5075 __free_page(eb->pages[i - 1]);
5076 __free_extent_buffer(eb);
5080 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
5083 return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
5086 static void check_buffer_tree_ref(struct extent_buffer *eb)
5089 /* the ref bit is tricky. We have to make sure it is set
5090 * if we have the buffer dirty. Otherwise the
5091 * code to free a buffer can end up dropping a dirty
5094 * Once the ref bit is set, it won't go away while the
5095 * buffer is dirty or in writeback, and it also won't
5096 * go away while we have the reference count on the
5099 * We can't just set the ref bit without bumping the
5100 * ref on the eb because free_extent_buffer might
5101 * see the ref bit and try to clear it. If this happens
5102 * free_extent_buffer might end up dropping our original
5103 * ref by mistake and freeing the page before we are able
5104 * to add one more ref.
5106 * So bump the ref count first, then set the bit. If someone
5107 * beat us to it, drop the ref we added.
5109 refs = atomic_read(&eb->refs);
5110 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5113 spin_lock(&eb->refs_lock);
5114 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5115 atomic_inc(&eb->refs);
5116 spin_unlock(&eb->refs_lock);
5119 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
5120 struct page *accessed)
5124 check_buffer_tree_ref(eb);
5126 num_pages = num_extent_pages(eb);
5127 for (i = 0; i < num_pages; i++) {
5128 struct page *p = eb->pages[i];
5131 mark_page_accessed(p);
5135 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
5138 struct extent_buffer *eb;
5141 eb = radix_tree_lookup(&fs_info->buffer_radix,
5142 start >> PAGE_SHIFT);
5143 if (eb && atomic_inc_not_zero(&eb->refs)) {
5146 * Lock our eb's refs_lock to avoid races with
5147 * free_extent_buffer. When we get our eb it might be flagged
5148 * with EXTENT_BUFFER_STALE and another task running
5149 * free_extent_buffer might have seen that flag set,
5150 * eb->refs == 2, that the buffer isn't under IO (dirty and
5151 * writeback flags not set) and it's still in the tree (flag
5152 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
5153 * of decrementing the extent buffer's reference count twice.
5154 * So here we could race and increment the eb's reference count,
5155 * clear its stale flag, mark it as dirty and drop our reference
5156 * before the other task finishes executing free_extent_buffer,
5157 * which would later result in an attempt to free an extent
5158 * buffer that is dirty.
5160 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
5161 spin_lock(&eb->refs_lock);
5162 spin_unlock(&eb->refs_lock);
5164 mark_extent_buffer_accessed(eb, NULL);
5172 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5173 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
5176 struct extent_buffer *eb, *exists = NULL;
5179 eb = find_extent_buffer(fs_info, start);
5182 eb = alloc_dummy_extent_buffer(fs_info, start);
5184 return ERR_PTR(-ENOMEM);
5185 eb->fs_info = fs_info;
5187 ret = radix_tree_preload(GFP_NOFS);
5189 exists = ERR_PTR(ret);
5192 spin_lock(&fs_info->buffer_lock);
5193 ret = radix_tree_insert(&fs_info->buffer_radix,
5194 start >> PAGE_SHIFT, eb);
5195 spin_unlock(&fs_info->buffer_lock);
5196 radix_tree_preload_end();
5197 if (ret == -EEXIST) {
5198 exists = find_extent_buffer(fs_info, start);
5204 check_buffer_tree_ref(eb);
5205 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5209 btrfs_release_extent_buffer(eb);
5214 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
5217 unsigned long len = fs_info->nodesize;
5220 unsigned long index = start >> PAGE_SHIFT;
5221 struct extent_buffer *eb;
5222 struct extent_buffer *exists = NULL;
5224 struct address_space *mapping = fs_info->btree_inode->i_mapping;
5228 if (!IS_ALIGNED(start, fs_info->sectorsize)) {
5229 btrfs_err(fs_info, "bad tree block start %llu", start);
5230 return ERR_PTR(-EINVAL);
5233 eb = find_extent_buffer(fs_info, start);
5237 eb = __alloc_extent_buffer(fs_info, start, len);
5239 return ERR_PTR(-ENOMEM);
5241 num_pages = num_extent_pages(eb);
5242 for (i = 0; i < num_pages; i++, index++) {
5243 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
5245 exists = ERR_PTR(-ENOMEM);
5249 spin_lock(&mapping->private_lock);
5250 if (PagePrivate(p)) {
5252 * We could have already allocated an eb for this page
5253 * and attached one so lets see if we can get a ref on
5254 * the existing eb, and if we can we know it's good and
5255 * we can just return that one, else we know we can just
5256 * overwrite page->private.
5258 exists = (struct extent_buffer *)p->private;
5259 if (atomic_inc_not_zero(&exists->refs)) {
5260 spin_unlock(&mapping->private_lock);
5263 mark_extent_buffer_accessed(exists, p);
5269 * Do this so attach doesn't complain and we need to
5270 * drop the ref the old guy had.
5272 ClearPagePrivate(p);
5273 WARN_ON(PageDirty(p));
5276 attach_extent_buffer_page(eb, p);
5277 spin_unlock(&mapping->private_lock);
5278 WARN_ON(PageDirty(p));
5280 if (!PageUptodate(p))
5284 * We can't unlock the pages just yet since the extent buffer
5285 * hasn't been properly inserted in the radix tree, this
5286 * opens a race with btree_releasepage which can free a page
5287 * while we are still filling in all pages for the buffer and
5292 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5294 ret = radix_tree_preload(GFP_NOFS);
5296 exists = ERR_PTR(ret);
5300 spin_lock(&fs_info->buffer_lock);
5301 ret = radix_tree_insert(&fs_info->buffer_radix,
5302 start >> PAGE_SHIFT, eb);
5303 spin_unlock(&fs_info->buffer_lock);
5304 radix_tree_preload_end();
5305 if (ret == -EEXIST) {
5306 exists = find_extent_buffer(fs_info, start);
5312 /* add one reference for the tree */
5313 check_buffer_tree_ref(eb);
5314 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5317 * Now it's safe to unlock the pages because any calls to
5318 * btree_releasepage will correctly detect that a page belongs to a
5319 * live buffer and won't free them prematurely.
5321 for (i = 0; i < num_pages; i++)
5322 unlock_page(eb->pages[i]);
5326 WARN_ON(!atomic_dec_and_test(&eb->refs));
5327 for (i = 0; i < num_pages; i++) {
5329 unlock_page(eb->pages[i]);
5332 btrfs_release_extent_buffer(eb);
5336 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5338 struct extent_buffer *eb =
5339 container_of(head, struct extent_buffer, rcu_head);
5341 __free_extent_buffer(eb);
5344 static int release_extent_buffer(struct extent_buffer *eb)
5345 __releases(&eb->refs_lock)
5347 lockdep_assert_held(&eb->refs_lock);
5349 WARN_ON(atomic_read(&eb->refs) == 0);
5350 if (atomic_dec_and_test(&eb->refs)) {
5351 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5352 struct btrfs_fs_info *fs_info = eb->fs_info;
5354 spin_unlock(&eb->refs_lock);
5356 spin_lock(&fs_info->buffer_lock);
5357 radix_tree_delete(&fs_info->buffer_radix,
5358 eb->start >> PAGE_SHIFT);
5359 spin_unlock(&fs_info->buffer_lock);
5361 spin_unlock(&eb->refs_lock);
5364 btrfs_leak_debug_del(&eb->fs_info->eb_leak_lock, &eb->leak_list);
5365 /* Should be safe to release our pages at this point */
5366 btrfs_release_extent_buffer_pages(eb);
5367 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5368 if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))) {
5369 __free_extent_buffer(eb);
5373 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5376 spin_unlock(&eb->refs_lock);
5381 void free_extent_buffer(struct extent_buffer *eb)
5389 refs = atomic_read(&eb->refs);
5390 if ((!test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) && refs <= 3)
5391 || (test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) &&
5394 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5399 spin_lock(&eb->refs_lock);
5400 if (atomic_read(&eb->refs) == 2 &&
5401 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5402 !extent_buffer_under_io(eb) &&
5403 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5404 atomic_dec(&eb->refs);
5407 * I know this is terrible, but it's temporary until we stop tracking
5408 * the uptodate bits and such for the extent buffers.
5410 release_extent_buffer(eb);
5413 void free_extent_buffer_stale(struct extent_buffer *eb)
5418 spin_lock(&eb->refs_lock);
5419 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5421 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5422 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5423 atomic_dec(&eb->refs);
5424 release_extent_buffer(eb);
5427 void clear_extent_buffer_dirty(const struct extent_buffer *eb)
5433 num_pages = num_extent_pages(eb);
5435 for (i = 0; i < num_pages; i++) {
5436 page = eb->pages[i];
5437 if (!PageDirty(page))
5441 WARN_ON(!PagePrivate(page));
5443 clear_page_dirty_for_io(page);
5444 xa_lock_irq(&page->mapping->i_pages);
5445 if (!PageDirty(page))
5446 __xa_clear_mark(&page->mapping->i_pages,
5447 page_index(page), PAGECACHE_TAG_DIRTY);
5448 xa_unlock_irq(&page->mapping->i_pages);
5449 ClearPageError(page);
5452 WARN_ON(atomic_read(&eb->refs) == 0);
5455 bool set_extent_buffer_dirty(struct extent_buffer *eb)
5461 check_buffer_tree_ref(eb);
5463 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5465 num_pages = num_extent_pages(eb);
5466 WARN_ON(atomic_read(&eb->refs) == 0);
5467 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5470 for (i = 0; i < num_pages; i++)
5471 set_page_dirty(eb->pages[i]);
5473 #ifdef CONFIG_BTRFS_DEBUG
5474 for (i = 0; i < num_pages; i++)
5475 ASSERT(PageDirty(eb->pages[i]));
5481 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5487 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5488 num_pages = num_extent_pages(eb);
5489 for (i = 0; i < num_pages; i++) {
5490 page = eb->pages[i];
5492 ClearPageUptodate(page);
5496 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5502 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5503 num_pages = num_extent_pages(eb);
5504 for (i = 0; i < num_pages; i++) {
5505 page = eb->pages[i];
5506 SetPageUptodate(page);
5510 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num)
5516 int locked_pages = 0;
5517 int all_uptodate = 1;
5519 unsigned long num_reads = 0;
5520 struct bio *bio = NULL;
5521 unsigned long bio_flags = 0;
5523 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5526 num_pages = num_extent_pages(eb);
5527 for (i = 0; i < num_pages; i++) {
5528 page = eb->pages[i];
5529 if (wait == WAIT_NONE) {
5530 if (!trylock_page(page))
5538 * We need to firstly lock all pages to make sure that
5539 * the uptodate bit of our pages won't be affected by
5540 * clear_extent_buffer_uptodate().
5542 for (i = 0; i < num_pages; i++) {
5543 page = eb->pages[i];
5544 if (!PageUptodate(page)) {
5551 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5555 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5556 eb->read_mirror = 0;
5557 atomic_set(&eb->io_pages, num_reads);
5558 for (i = 0; i < num_pages; i++) {
5559 page = eb->pages[i];
5561 if (!PageUptodate(page)) {
5563 atomic_dec(&eb->io_pages);
5568 ClearPageError(page);
5569 err = __extent_read_full_page(page,
5570 btree_get_extent, &bio,
5571 mirror_num, &bio_flags,
5576 * We use &bio in above __extent_read_full_page,
5577 * so we ensure that if it returns error, the
5578 * current page fails to add itself to bio and
5579 * it's been unlocked.
5581 * We must dec io_pages by ourselves.
5583 atomic_dec(&eb->io_pages);
5591 err = submit_one_bio(bio, mirror_num, bio_flags);
5596 if (ret || wait != WAIT_COMPLETE)
5599 for (i = 0; i < num_pages; i++) {
5600 page = eb->pages[i];
5601 wait_on_page_locked(page);
5602 if (!PageUptodate(page))
5609 while (locked_pages > 0) {
5611 page = eb->pages[locked_pages];
5617 void read_extent_buffer(const struct extent_buffer *eb, void *dstv,
5618 unsigned long start, unsigned long len)
5624 char *dst = (char *)dstv;
5625 unsigned long i = start >> PAGE_SHIFT;
5627 if (start + len > eb->len) {
5628 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5629 eb->start, eb->len, start, len);
5630 memset(dst, 0, len);
5634 offset = offset_in_page(start);
5637 page = eb->pages[i];
5639 cur = min(len, (PAGE_SIZE - offset));
5640 kaddr = page_address(page);
5641 memcpy(dst, kaddr + offset, cur);
5650 int read_extent_buffer_to_user(const struct extent_buffer *eb,
5652 unsigned long start, unsigned long len)
5658 char __user *dst = (char __user *)dstv;
5659 unsigned long i = start >> PAGE_SHIFT;
5662 WARN_ON(start > eb->len);
5663 WARN_ON(start + len > eb->start + eb->len);
5665 offset = offset_in_page(start);
5668 page = eb->pages[i];
5670 cur = min(len, (PAGE_SIZE - offset));
5671 kaddr = page_address(page);
5672 if (copy_to_user(dst, kaddr + offset, cur)) {
5686 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
5687 unsigned long start, unsigned long len)
5693 char *ptr = (char *)ptrv;
5694 unsigned long i = start >> PAGE_SHIFT;
5697 WARN_ON(start > eb->len);
5698 WARN_ON(start + len > eb->start + eb->len);
5700 offset = offset_in_page(start);
5703 page = eb->pages[i];
5705 cur = min(len, (PAGE_SIZE - offset));
5707 kaddr = page_address(page);
5708 ret = memcmp(ptr, kaddr + offset, cur);
5720 void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
5725 WARN_ON(!PageUptodate(eb->pages[0]));
5726 kaddr = page_address(eb->pages[0]);
5727 memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
5731 void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *srcv)
5735 WARN_ON(!PageUptodate(eb->pages[0]));
5736 kaddr = page_address(eb->pages[0]);
5737 memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
5741 void write_extent_buffer(const struct extent_buffer *eb, const void *srcv,
5742 unsigned long start, unsigned long len)
5748 char *src = (char *)srcv;
5749 unsigned long i = start >> PAGE_SHIFT;
5751 WARN_ON(start > eb->len);
5752 WARN_ON(start + len > eb->start + eb->len);
5754 offset = offset_in_page(start);
5757 page = eb->pages[i];
5758 WARN_ON(!PageUptodate(page));
5760 cur = min(len, PAGE_SIZE - offset);
5761 kaddr = page_address(page);
5762 memcpy(kaddr + offset, src, cur);
5771 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
5778 unsigned long i = start >> PAGE_SHIFT;
5780 WARN_ON(start > eb->len);
5781 WARN_ON(start + len > eb->start + eb->len);
5783 offset = offset_in_page(start);
5786 page = eb->pages[i];
5787 WARN_ON(!PageUptodate(page));
5789 cur = min(len, PAGE_SIZE - offset);
5790 kaddr = page_address(page);
5791 memset(kaddr + offset, 0, cur);
5799 void copy_extent_buffer_full(const struct extent_buffer *dst,
5800 const struct extent_buffer *src)
5805 ASSERT(dst->len == src->len);
5807 num_pages = num_extent_pages(dst);
5808 for (i = 0; i < num_pages; i++)
5809 copy_page(page_address(dst->pages[i]),
5810 page_address(src->pages[i]));
5813 void copy_extent_buffer(const struct extent_buffer *dst,
5814 const struct extent_buffer *src,
5815 unsigned long dst_offset, unsigned long src_offset,
5818 u64 dst_len = dst->len;
5823 unsigned long i = dst_offset >> PAGE_SHIFT;
5825 WARN_ON(src->len != dst_len);
5827 offset = offset_in_page(dst_offset);
5830 page = dst->pages[i];
5831 WARN_ON(!PageUptodate(page));
5833 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5835 kaddr = page_address(page);
5836 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5846 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5848 * @eb: the extent buffer
5849 * @start: offset of the bitmap item in the extent buffer
5851 * @page_index: return index of the page in the extent buffer that contains the
5853 * @page_offset: return offset into the page given by page_index
5855 * This helper hides the ugliness of finding the byte in an extent buffer which
5856 * contains a given bit.
5858 static inline void eb_bitmap_offset(const struct extent_buffer *eb,
5859 unsigned long start, unsigned long nr,
5860 unsigned long *page_index,
5861 size_t *page_offset)
5863 size_t byte_offset = BIT_BYTE(nr);
5867 * The byte we want is the offset of the extent buffer + the offset of
5868 * the bitmap item in the extent buffer + the offset of the byte in the
5871 offset = start + byte_offset;
5873 *page_index = offset >> PAGE_SHIFT;
5874 *page_offset = offset_in_page(offset);
5878 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5879 * @eb: the extent buffer
5880 * @start: offset of the bitmap item in the extent buffer
5881 * @nr: bit number to test
5883 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
5891 eb_bitmap_offset(eb, start, nr, &i, &offset);
5892 page = eb->pages[i];
5893 WARN_ON(!PageUptodate(page));
5894 kaddr = page_address(page);
5895 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5899 * extent_buffer_bitmap_set - set an area of a bitmap
5900 * @eb: the extent buffer
5901 * @start: offset of the bitmap item in the extent buffer
5902 * @pos: bit number of the first bit
5903 * @len: number of bits to set
5905 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
5906 unsigned long pos, unsigned long len)
5912 const unsigned int size = pos + len;
5913 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5914 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5916 eb_bitmap_offset(eb, start, pos, &i, &offset);
5917 page = eb->pages[i];
5918 WARN_ON(!PageUptodate(page));
5919 kaddr = page_address(page);
5921 while (len >= bits_to_set) {
5922 kaddr[offset] |= mask_to_set;
5924 bits_to_set = BITS_PER_BYTE;
5926 if (++offset >= PAGE_SIZE && len > 0) {
5928 page = eb->pages[++i];
5929 WARN_ON(!PageUptodate(page));
5930 kaddr = page_address(page);
5934 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5935 kaddr[offset] |= mask_to_set;
5941 * extent_buffer_bitmap_clear - clear an area of a bitmap
5942 * @eb: the extent buffer
5943 * @start: offset of the bitmap item in the extent buffer
5944 * @pos: bit number of the first bit
5945 * @len: number of bits to clear
5947 void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
5948 unsigned long start, unsigned long pos,
5955 const unsigned int size = pos + len;
5956 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5957 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5959 eb_bitmap_offset(eb, start, pos, &i, &offset);
5960 page = eb->pages[i];
5961 WARN_ON(!PageUptodate(page));
5962 kaddr = page_address(page);
5964 while (len >= bits_to_clear) {
5965 kaddr[offset] &= ~mask_to_clear;
5966 len -= bits_to_clear;
5967 bits_to_clear = BITS_PER_BYTE;
5969 if (++offset >= PAGE_SIZE && len > 0) {
5971 page = eb->pages[++i];
5972 WARN_ON(!PageUptodate(page));
5973 kaddr = page_address(page);
5977 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5978 kaddr[offset] &= ~mask_to_clear;
5982 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5984 unsigned long distance = (src > dst) ? src - dst : dst - src;
5985 return distance < len;
5988 static void copy_pages(struct page *dst_page, struct page *src_page,
5989 unsigned long dst_off, unsigned long src_off,
5992 char *dst_kaddr = page_address(dst_page);
5994 int must_memmove = 0;
5996 if (dst_page != src_page) {
5997 src_kaddr = page_address(src_page);
5999 src_kaddr = dst_kaddr;
6000 if (areas_overlap(src_off, dst_off, len))
6005 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
6007 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
6010 void memcpy_extent_buffer(const struct extent_buffer *dst,
6011 unsigned long dst_offset, unsigned long src_offset,
6014 struct btrfs_fs_info *fs_info = dst->fs_info;
6016 size_t dst_off_in_page;
6017 size_t src_off_in_page;
6018 unsigned long dst_i;
6019 unsigned long src_i;
6021 if (src_offset + len > dst->len) {
6023 "memmove bogus src_offset %lu move len %lu dst len %lu",
6024 src_offset, len, dst->len);
6027 if (dst_offset + len > dst->len) {
6029 "memmove bogus dst_offset %lu move len %lu dst len %lu",
6030 dst_offset, len, dst->len);
6035 dst_off_in_page = offset_in_page(dst_offset);
6036 src_off_in_page = offset_in_page(src_offset);
6038 dst_i = dst_offset >> PAGE_SHIFT;
6039 src_i = src_offset >> PAGE_SHIFT;
6041 cur = min(len, (unsigned long)(PAGE_SIZE -
6043 cur = min_t(unsigned long, cur,
6044 (unsigned long)(PAGE_SIZE - dst_off_in_page));
6046 copy_pages(dst->pages[dst_i], dst->pages[src_i],
6047 dst_off_in_page, src_off_in_page, cur);
6055 void memmove_extent_buffer(const struct extent_buffer *dst,
6056 unsigned long dst_offset, unsigned long src_offset,
6059 struct btrfs_fs_info *fs_info = dst->fs_info;
6061 size_t dst_off_in_page;
6062 size_t src_off_in_page;
6063 unsigned long dst_end = dst_offset + len - 1;
6064 unsigned long src_end = src_offset + len - 1;
6065 unsigned long dst_i;
6066 unsigned long src_i;
6068 if (src_offset + len > dst->len) {
6070 "memmove bogus src_offset %lu move len %lu len %lu",
6071 src_offset, len, dst->len);
6074 if (dst_offset + len > dst->len) {
6076 "memmove bogus dst_offset %lu move len %lu len %lu",
6077 dst_offset, len, dst->len);
6080 if (dst_offset < src_offset) {
6081 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
6085 dst_i = dst_end >> PAGE_SHIFT;
6086 src_i = src_end >> PAGE_SHIFT;
6088 dst_off_in_page = offset_in_page(dst_end);
6089 src_off_in_page = offset_in_page(src_end);
6091 cur = min_t(unsigned long, len, src_off_in_page + 1);
6092 cur = min(cur, dst_off_in_page + 1);
6093 copy_pages(dst->pages[dst_i], dst->pages[src_i],
6094 dst_off_in_page - cur + 1,
6095 src_off_in_page - cur + 1, cur);
6103 int try_release_extent_buffer(struct page *page)
6105 struct extent_buffer *eb;
6108 * We need to make sure nobody is attaching this page to an eb right
6111 spin_lock(&page->mapping->private_lock);
6112 if (!PagePrivate(page)) {
6113 spin_unlock(&page->mapping->private_lock);
6117 eb = (struct extent_buffer *)page->private;
6121 * This is a little awful but should be ok, we need to make sure that
6122 * the eb doesn't disappear out from under us while we're looking at
6125 spin_lock(&eb->refs_lock);
6126 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
6127 spin_unlock(&eb->refs_lock);
6128 spin_unlock(&page->mapping->private_lock);
6131 spin_unlock(&page->mapping->private_lock);
6134 * If tree ref isn't set then we know the ref on this eb is a real ref,
6135 * so just return, this page will likely be freed soon anyway.
6137 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
6138 spin_unlock(&eb->refs_lock);
6142 return release_extent_buffer(eb);