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]);
2002 for (; i < ret; i++)
2016 if (err && index_ret)
2017 *index_ret = start_index + pages_locked - 1;
2021 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
2022 struct page *locked_page,
2023 unsigned clear_bits,
2024 unsigned long page_ops)
2026 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0,
2029 __process_pages_contig(inode->i_mapping, locked_page,
2030 start >> PAGE_SHIFT, end >> PAGE_SHIFT,
2035 * count the number of bytes in the tree that have a given bit(s)
2036 * set. This can be fairly slow, except for EXTENT_DIRTY which is
2037 * cached. The total number found is returned.
2039 u64 count_range_bits(struct extent_io_tree *tree,
2040 u64 *start, u64 search_end, u64 max_bytes,
2041 unsigned bits, int contig)
2043 struct rb_node *node;
2044 struct extent_state *state;
2045 u64 cur_start = *start;
2046 u64 total_bytes = 0;
2050 if (WARN_ON(search_end <= cur_start))
2053 spin_lock(&tree->lock);
2054 if (cur_start == 0 && bits == EXTENT_DIRTY) {
2055 total_bytes = tree->dirty_bytes;
2059 * this search will find all the extents that end after
2062 node = tree_search(tree, cur_start);
2067 state = rb_entry(node, struct extent_state, rb_node);
2068 if (state->start > search_end)
2070 if (contig && found && state->start > last + 1)
2072 if (state->end >= cur_start && (state->state & bits) == bits) {
2073 total_bytes += min(search_end, state->end) + 1 -
2074 max(cur_start, state->start);
2075 if (total_bytes >= max_bytes)
2078 *start = max(cur_start, state->start);
2082 } else if (contig && found) {
2085 node = rb_next(node);
2090 spin_unlock(&tree->lock);
2095 * set the private field for a given byte offset in the tree. If there isn't
2096 * an extent_state there already, this does nothing.
2098 int set_state_failrec(struct extent_io_tree *tree, u64 start,
2099 struct io_failure_record *failrec)
2101 struct rb_node *node;
2102 struct extent_state *state;
2105 spin_lock(&tree->lock);
2107 * this search will find all the extents that end after
2110 node = tree_search(tree, start);
2115 state = rb_entry(node, struct extent_state, rb_node);
2116 if (state->start != start) {
2120 state->failrec = failrec;
2122 spin_unlock(&tree->lock);
2126 int get_state_failrec(struct extent_io_tree *tree, u64 start,
2127 struct io_failure_record **failrec)
2129 struct rb_node *node;
2130 struct extent_state *state;
2133 spin_lock(&tree->lock);
2135 * this search will find all the extents that end after
2138 node = tree_search(tree, start);
2143 state = rb_entry(node, struct extent_state, rb_node);
2144 if (state->start != start) {
2148 *failrec = state->failrec;
2150 spin_unlock(&tree->lock);
2155 * searches a range in the state tree for a given mask.
2156 * If 'filled' == 1, this returns 1 only if every extent in the tree
2157 * has the bits set. Otherwise, 1 is returned if any bit in the
2158 * range is found set.
2160 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
2161 unsigned bits, int filled, struct extent_state *cached)
2163 struct extent_state *state = NULL;
2164 struct rb_node *node;
2167 spin_lock(&tree->lock);
2168 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
2169 cached->end > start)
2170 node = &cached->rb_node;
2172 node = tree_search(tree, start);
2173 while (node && start <= end) {
2174 state = rb_entry(node, struct extent_state, rb_node);
2176 if (filled && state->start > start) {
2181 if (state->start > end)
2184 if (state->state & bits) {
2188 } else if (filled) {
2193 if (state->end == (u64)-1)
2196 start = state->end + 1;
2199 node = rb_next(node);
2206 spin_unlock(&tree->lock);
2211 * helper function to set a given page up to date if all the
2212 * extents in the tree for that page are up to date
2214 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
2216 u64 start = page_offset(page);
2217 u64 end = start + PAGE_SIZE - 1;
2218 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
2219 SetPageUptodate(page);
2222 int free_io_failure(struct extent_io_tree *failure_tree,
2223 struct extent_io_tree *io_tree,
2224 struct io_failure_record *rec)
2229 set_state_failrec(failure_tree, rec->start, NULL);
2230 ret = clear_extent_bits(failure_tree, rec->start,
2231 rec->start + rec->len - 1,
2232 EXTENT_LOCKED | EXTENT_DIRTY);
2236 ret = clear_extent_bits(io_tree, rec->start,
2237 rec->start + rec->len - 1,
2247 * this bypasses the standard btrfs submit functions deliberately, as
2248 * the standard behavior is to write all copies in a raid setup. here we only
2249 * want to write the one bad copy. so we do the mapping for ourselves and issue
2250 * submit_bio directly.
2251 * to avoid any synchronization issues, wait for the data after writing, which
2252 * actually prevents the read that triggered the error from finishing.
2253 * currently, there can be no more than two copies of every data bit. thus,
2254 * exactly one rewrite is required.
2256 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
2257 u64 length, u64 logical, struct page *page,
2258 unsigned int pg_offset, int mirror_num)
2261 struct btrfs_device *dev;
2264 struct btrfs_bio *bbio = NULL;
2267 ASSERT(!(fs_info->sb->s_flags & SB_RDONLY));
2268 BUG_ON(!mirror_num);
2270 bio = btrfs_io_bio_alloc(1);
2271 bio->bi_iter.bi_size = 0;
2272 map_length = length;
2275 * Avoid races with device replace and make sure our bbio has devices
2276 * associated to its stripes that don't go away while we are doing the
2277 * read repair operation.
2279 btrfs_bio_counter_inc_blocked(fs_info);
2280 if (btrfs_is_parity_mirror(fs_info, logical, length)) {
2282 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
2283 * to update all raid stripes, but here we just want to correct
2284 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
2285 * stripe's dev and sector.
2287 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical,
2288 &map_length, &bbio, 0);
2290 btrfs_bio_counter_dec(fs_info);
2294 ASSERT(bbio->mirror_num == 1);
2296 ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
2297 &map_length, &bbio, mirror_num);
2299 btrfs_bio_counter_dec(fs_info);
2303 BUG_ON(mirror_num != bbio->mirror_num);
2306 sector = bbio->stripes[bbio->mirror_num - 1].physical >> 9;
2307 bio->bi_iter.bi_sector = sector;
2308 dev = bbio->stripes[bbio->mirror_num - 1].dev;
2309 btrfs_put_bbio(bbio);
2310 if (!dev || !dev->bdev ||
2311 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
2312 btrfs_bio_counter_dec(fs_info);
2316 bio_set_dev(bio, dev->bdev);
2317 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
2318 bio_add_page(bio, page, length, pg_offset);
2320 if (btrfsic_submit_bio_wait(bio)) {
2321 /* try to remap that extent elsewhere? */
2322 btrfs_bio_counter_dec(fs_info);
2324 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2328 btrfs_info_rl_in_rcu(fs_info,
2329 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2331 rcu_str_deref(dev->name), sector);
2332 btrfs_bio_counter_dec(fs_info);
2337 int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num)
2339 struct btrfs_fs_info *fs_info = eb->fs_info;
2340 u64 start = eb->start;
2341 int i, num_pages = num_extent_pages(eb);
2344 if (sb_rdonly(fs_info->sb))
2347 for (i = 0; i < num_pages; i++) {
2348 struct page *p = eb->pages[i];
2350 ret = repair_io_failure(fs_info, 0, start, PAGE_SIZE, start, p,
2351 start - page_offset(p), mirror_num);
2361 * each time an IO finishes, we do a fast check in the IO failure tree
2362 * to see if we need to process or clean up an io_failure_record
2364 int clean_io_failure(struct btrfs_fs_info *fs_info,
2365 struct extent_io_tree *failure_tree,
2366 struct extent_io_tree *io_tree, u64 start,
2367 struct page *page, u64 ino, unsigned int pg_offset)
2370 struct io_failure_record *failrec;
2371 struct extent_state *state;
2376 ret = count_range_bits(failure_tree, &private, (u64)-1, 1,
2381 ret = get_state_failrec(failure_tree, start, &failrec);
2385 BUG_ON(!failrec->this_mirror);
2387 if (failrec->in_validation) {
2388 /* there was no real error, just free the record */
2389 btrfs_debug(fs_info,
2390 "clean_io_failure: freeing dummy error at %llu",
2394 if (sb_rdonly(fs_info->sb))
2397 spin_lock(&io_tree->lock);
2398 state = find_first_extent_bit_state(io_tree,
2401 spin_unlock(&io_tree->lock);
2403 if (state && state->start <= failrec->start &&
2404 state->end >= failrec->start + failrec->len - 1) {
2405 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2407 if (num_copies > 1) {
2408 repair_io_failure(fs_info, ino, start, failrec->len,
2409 failrec->logical, page, pg_offset,
2410 failrec->failed_mirror);
2415 free_io_failure(failure_tree, io_tree, failrec);
2421 * Can be called when
2422 * - hold extent lock
2423 * - under ordered extent
2424 * - the inode is freeing
2426 void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end)
2428 struct extent_io_tree *failure_tree = &inode->io_failure_tree;
2429 struct io_failure_record *failrec;
2430 struct extent_state *state, *next;
2432 if (RB_EMPTY_ROOT(&failure_tree->state))
2435 spin_lock(&failure_tree->lock);
2436 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2438 if (state->start > end)
2441 ASSERT(state->end <= end);
2443 next = next_state(state);
2445 failrec = state->failrec;
2446 free_extent_state(state);
2451 spin_unlock(&failure_tree->lock);
2454 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2455 struct io_failure_record **failrec_ret)
2457 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2458 struct io_failure_record *failrec;
2459 struct extent_map *em;
2460 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2461 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2462 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2466 ret = get_state_failrec(failure_tree, start, &failrec);
2468 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2472 failrec->start = start;
2473 failrec->len = end - start + 1;
2474 failrec->this_mirror = 0;
2475 failrec->bio_flags = 0;
2476 failrec->in_validation = 0;
2478 read_lock(&em_tree->lock);
2479 em = lookup_extent_mapping(em_tree, start, failrec->len);
2481 read_unlock(&em_tree->lock);
2486 if (em->start > start || em->start + em->len <= start) {
2487 free_extent_map(em);
2490 read_unlock(&em_tree->lock);
2496 logical = start - em->start;
2497 logical = em->block_start + logical;
2498 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2499 logical = em->block_start;
2500 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2501 extent_set_compress_type(&failrec->bio_flags,
2505 btrfs_debug(fs_info,
2506 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2507 logical, start, failrec->len);
2509 failrec->logical = logical;
2510 free_extent_map(em);
2512 /* set the bits in the private failure tree */
2513 ret = set_extent_bits(failure_tree, start, end,
2514 EXTENT_LOCKED | EXTENT_DIRTY);
2516 ret = set_state_failrec(failure_tree, start, failrec);
2517 /* set the bits in the inode's tree */
2519 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2525 btrfs_debug(fs_info,
2526 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2527 failrec->logical, failrec->start, failrec->len,
2528 failrec->in_validation);
2530 * when data can be on disk more than twice, add to failrec here
2531 * (e.g. with a list for failed_mirror) to make
2532 * clean_io_failure() clean all those errors at once.
2536 *failrec_ret = failrec;
2541 static bool btrfs_check_repairable(struct inode *inode, bool needs_validation,
2542 struct io_failure_record *failrec,
2545 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2548 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
2549 if (num_copies == 1) {
2551 * we only have a single copy of the data, so don't bother with
2552 * all the retry and error correction code that follows. no
2553 * matter what the error is, it is very likely to persist.
2555 btrfs_debug(fs_info,
2556 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2557 num_copies, failrec->this_mirror, failed_mirror);
2562 * there are two premises:
2563 * a) deliver good data to the caller
2564 * b) correct the bad sectors on disk
2566 if (needs_validation) {
2568 * to fulfill b), we need to know the exact failing sectors, as
2569 * we don't want to rewrite any more than the failed ones. thus,
2570 * we need separate read requests for the failed bio
2572 * if the following BUG_ON triggers, our validation request got
2573 * merged. we need separate requests for our algorithm to work.
2575 BUG_ON(failrec->in_validation);
2576 failrec->in_validation = 1;
2577 failrec->this_mirror = failed_mirror;
2580 * we're ready to fulfill a) and b) alongside. get a good copy
2581 * of the failed sector and if we succeed, we have setup
2582 * everything for repair_io_failure to do the rest for us.
2584 if (failrec->in_validation) {
2585 BUG_ON(failrec->this_mirror != failed_mirror);
2586 failrec->in_validation = 0;
2587 failrec->this_mirror = 0;
2589 failrec->failed_mirror = failed_mirror;
2590 failrec->this_mirror++;
2591 if (failrec->this_mirror == failed_mirror)
2592 failrec->this_mirror++;
2595 if (failrec->this_mirror > num_copies) {
2596 btrfs_debug(fs_info,
2597 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2598 num_copies, failrec->this_mirror, failed_mirror);
2605 static bool btrfs_io_needs_validation(struct inode *inode, struct bio *bio)
2608 const u32 blocksize = inode->i_sb->s_blocksize;
2611 * If bi_status is BLK_STS_OK, then this was a checksum error, not an
2612 * I/O error. In this case, we already know exactly which sector was
2613 * bad, so we don't need to validate.
2615 if (bio->bi_status == BLK_STS_OK)
2619 * We need to validate each sector individually if the failed I/O was
2620 * for multiple sectors.
2622 * There are a few possible bios that can end up here:
2623 * 1. A buffered read bio, which is not cloned.
2624 * 2. A direct I/O read bio, which is cloned.
2625 * 3. A (buffered or direct) repair bio, which is not cloned.
2627 * For cloned bios (case 2), we can get the size from
2628 * btrfs_io_bio->iter; for non-cloned bios (cases 1 and 3), we can get
2629 * it from the bvecs.
2631 if (bio_flagged(bio, BIO_CLONED)) {
2632 if (btrfs_io_bio(bio)->iter.bi_size > blocksize)
2635 struct bio_vec *bvec;
2638 bio_for_each_bvec_all(bvec, bio, i) {
2639 len += bvec->bv_len;
2640 if (len > blocksize)
2647 blk_status_t btrfs_submit_read_repair(struct inode *inode,
2648 struct bio *failed_bio, u64 phy_offset,
2649 struct page *page, unsigned int pgoff,
2650 u64 start, u64 end, int failed_mirror,
2651 submit_bio_hook_t *submit_bio_hook)
2653 struct io_failure_record *failrec;
2654 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2655 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2656 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2657 struct btrfs_io_bio *failed_io_bio = btrfs_io_bio(failed_bio);
2658 const int icsum = phy_offset >> inode->i_sb->s_blocksize_bits;
2659 bool need_validation;
2660 struct bio *repair_bio;
2661 struct btrfs_io_bio *repair_io_bio;
2662 blk_status_t status;
2665 btrfs_debug(fs_info,
2666 "repair read error: read error at %llu", start);
2668 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2670 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2672 return errno_to_blk_status(ret);
2674 need_validation = btrfs_io_needs_validation(inode, failed_bio);
2676 if (!btrfs_check_repairable(inode, need_validation, failrec,
2678 free_io_failure(failure_tree, tree, failrec);
2679 return BLK_STS_IOERR;
2682 repair_bio = btrfs_io_bio_alloc(1);
2683 repair_io_bio = btrfs_io_bio(repair_bio);
2684 repair_bio->bi_opf = REQ_OP_READ;
2685 if (need_validation)
2686 repair_bio->bi_opf |= REQ_FAILFAST_DEV;
2687 repair_bio->bi_end_io = failed_bio->bi_end_io;
2688 repair_bio->bi_iter.bi_sector = failrec->logical >> 9;
2689 repair_bio->bi_private = failed_bio->bi_private;
2691 if (failed_io_bio->csum) {
2692 const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2694 repair_io_bio->csum = repair_io_bio->csum_inline;
2695 memcpy(repair_io_bio->csum,
2696 failed_io_bio->csum + csum_size * icsum, csum_size);
2699 bio_add_page(repair_bio, page, failrec->len, pgoff);
2700 repair_io_bio->logical = failrec->start;
2701 repair_io_bio->iter = repair_bio->bi_iter;
2703 btrfs_debug(btrfs_sb(inode->i_sb),
2704 "repair read error: submitting new read to mirror %d, in_validation=%d",
2705 failrec->this_mirror, failrec->in_validation);
2707 status = submit_bio_hook(inode, repair_bio, failrec->this_mirror,
2708 failrec->bio_flags);
2710 free_io_failure(failure_tree, tree, failrec);
2711 bio_put(repair_bio);
2716 /* lots and lots of room for performance fixes in the end_bio funcs */
2718 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2720 int uptodate = (err == 0);
2723 btrfs_writepage_endio_finish_ordered(page, start, end, uptodate);
2726 ClearPageUptodate(page);
2728 ret = err < 0 ? err : -EIO;
2729 mapping_set_error(page->mapping, ret);
2734 * after a writepage IO is done, we need to:
2735 * clear the uptodate bits on error
2736 * clear the writeback bits in the extent tree for this IO
2737 * end_page_writeback if the page has no more pending IO
2739 * Scheduling is not allowed, so the extent state tree is expected
2740 * to have one and only one object corresponding to this IO.
2742 static void end_bio_extent_writepage(struct bio *bio)
2744 int error = blk_status_to_errno(bio->bi_status);
2745 struct bio_vec *bvec;
2748 struct bvec_iter_all iter_all;
2750 ASSERT(!bio_flagged(bio, BIO_CLONED));
2751 bio_for_each_segment_all(bvec, bio, iter_all) {
2752 struct page *page = bvec->bv_page;
2753 struct inode *inode = page->mapping->host;
2754 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2756 /* We always issue full-page reads, but if some block
2757 * in a page fails to read, blk_update_request() will
2758 * advance bv_offset and adjust bv_len to compensate.
2759 * Print a warning for nonzero offsets, and an error
2760 * if they don't add up to a full page. */
2761 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2762 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2764 "partial page write in btrfs with offset %u and length %u",
2765 bvec->bv_offset, bvec->bv_len);
2768 "incomplete page write in btrfs with offset %u and length %u",
2769 bvec->bv_offset, bvec->bv_len);
2772 start = page_offset(page);
2773 end = start + bvec->bv_offset + bvec->bv_len - 1;
2775 end_extent_writepage(page, error, start, end);
2776 end_page_writeback(page);
2783 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2786 struct extent_state *cached = NULL;
2787 u64 end = start + len - 1;
2789 if (uptodate && tree->track_uptodate)
2790 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2791 unlock_extent_cached_atomic(tree, start, end, &cached);
2795 * after a readpage IO is done, we need to:
2796 * clear the uptodate bits on error
2797 * set the uptodate bits if things worked
2798 * set the page up to date if all extents in the tree are uptodate
2799 * clear the lock bit in the extent tree
2800 * unlock the page if there are no other extents locked for it
2802 * Scheduling is not allowed, so the extent state tree is expected
2803 * to have one and only one object corresponding to this IO.
2805 static void end_bio_extent_readpage(struct bio *bio)
2807 struct bio_vec *bvec;
2808 int uptodate = !bio->bi_status;
2809 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2810 struct extent_io_tree *tree, *failure_tree;
2815 u64 extent_start = 0;
2819 struct bvec_iter_all iter_all;
2821 ASSERT(!bio_flagged(bio, BIO_CLONED));
2822 bio_for_each_segment_all(bvec, bio, iter_all) {
2823 struct page *page = bvec->bv_page;
2824 struct inode *inode = page->mapping->host;
2825 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2826 bool data_inode = btrfs_ino(BTRFS_I(inode))
2827 != BTRFS_BTREE_INODE_OBJECTID;
2829 btrfs_debug(fs_info,
2830 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2831 (u64)bio->bi_iter.bi_sector, bio->bi_status,
2832 io_bio->mirror_num);
2833 tree = &BTRFS_I(inode)->io_tree;
2834 failure_tree = &BTRFS_I(inode)->io_failure_tree;
2836 /* We always issue full-page reads, but if some block
2837 * in a page fails to read, blk_update_request() will
2838 * advance bv_offset and adjust bv_len to compensate.
2839 * Print a warning for nonzero offsets, and an error
2840 * if they don't add up to a full page. */
2841 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2842 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2844 "partial page read in btrfs with offset %u and length %u",
2845 bvec->bv_offset, bvec->bv_len);
2848 "incomplete page read in btrfs with offset %u and length %u",
2849 bvec->bv_offset, bvec->bv_len);
2852 start = page_offset(page);
2853 end = start + bvec->bv_offset + bvec->bv_len - 1;
2856 mirror = io_bio->mirror_num;
2857 if (likely(uptodate)) {
2858 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2864 clean_io_failure(BTRFS_I(inode)->root->fs_info,
2865 failure_tree, tree, start,
2867 btrfs_ino(BTRFS_I(inode)), 0);
2870 if (likely(uptodate))
2876 * The generic bio_readpage_error handles errors the
2877 * following way: If possible, new read requests are
2878 * created and submitted and will end up in
2879 * end_bio_extent_readpage as well (if we're lucky,
2880 * not in the !uptodate case). In that case it returns
2881 * 0 and we just go on with the next page in our bio.
2882 * If it can't handle the error it will return -EIO and
2883 * we remain responsible for that page.
2885 if (!btrfs_submit_read_repair(inode, bio, offset, page,
2886 start - page_offset(page),
2888 tree->ops->submit_bio_hook)) {
2889 uptodate = !bio->bi_status;
2894 struct extent_buffer *eb;
2896 eb = (struct extent_buffer *)page->private;
2897 set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
2898 eb->read_mirror = mirror;
2899 atomic_dec(&eb->io_pages);
2900 if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD,
2902 btree_readahead_hook(eb, -EIO);
2905 if (likely(uptodate)) {
2906 loff_t i_size = i_size_read(inode);
2907 pgoff_t end_index = i_size >> PAGE_SHIFT;
2910 /* Zero out the end if this page straddles i_size */
2911 off = offset_in_page(i_size);
2912 if (page->index == end_index && off)
2913 zero_user_segment(page, off, PAGE_SIZE);
2914 SetPageUptodate(page);
2916 ClearPageUptodate(page);
2922 if (unlikely(!uptodate)) {
2924 endio_readpage_release_extent(tree,
2930 endio_readpage_release_extent(tree, start,
2931 end - start + 1, 0);
2932 } else if (!extent_len) {
2933 extent_start = start;
2934 extent_len = end + 1 - start;
2935 } else if (extent_start + extent_len == start) {
2936 extent_len += end + 1 - start;
2938 endio_readpage_release_extent(tree, extent_start,
2939 extent_len, uptodate);
2940 extent_start = start;
2941 extent_len = end + 1 - start;
2946 endio_readpage_release_extent(tree, extent_start, extent_len,
2948 btrfs_io_bio_free_csum(io_bio);
2953 * Initialize the members up to but not including 'bio'. Use after allocating a
2954 * new bio by bio_alloc_bioset as it does not initialize the bytes outside of
2955 * 'bio' because use of __GFP_ZERO is not supported.
2957 static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio)
2959 memset(btrfs_bio, 0, offsetof(struct btrfs_io_bio, bio));
2963 * The following helpers allocate a bio. As it's backed by a bioset, it'll
2964 * never fail. We're returning a bio right now but you can call btrfs_io_bio
2965 * for the appropriate container_of magic
2967 struct bio *btrfs_bio_alloc(u64 first_byte)
2971 bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, &btrfs_bioset);
2972 bio->bi_iter.bi_sector = first_byte >> 9;
2973 btrfs_io_bio_init(btrfs_io_bio(bio));
2977 struct bio *btrfs_bio_clone(struct bio *bio)
2979 struct btrfs_io_bio *btrfs_bio;
2982 /* Bio allocation backed by a bioset does not fail */
2983 new = bio_clone_fast(bio, GFP_NOFS, &btrfs_bioset);
2984 btrfs_bio = btrfs_io_bio(new);
2985 btrfs_io_bio_init(btrfs_bio);
2986 btrfs_bio->iter = bio->bi_iter;
2990 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs)
2994 /* Bio allocation backed by a bioset does not fail */
2995 bio = bio_alloc_bioset(GFP_NOFS, nr_iovecs, &btrfs_bioset);
2996 btrfs_io_bio_init(btrfs_io_bio(bio));
3000 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
3003 struct btrfs_io_bio *btrfs_bio;
3005 /* this will never fail when it's backed by a bioset */
3006 bio = bio_clone_fast(orig, GFP_NOFS, &btrfs_bioset);
3009 btrfs_bio = btrfs_io_bio(bio);
3010 btrfs_io_bio_init(btrfs_bio);
3012 bio_trim(bio, offset >> 9, size >> 9);
3013 btrfs_bio->iter = bio->bi_iter;
3018 * @opf: bio REQ_OP_* and REQ_* flags as one value
3019 * @wbc: optional writeback control for io accounting
3020 * @page: page to add to the bio
3021 * @pg_offset: offset of the new bio or to check whether we are adding
3022 * a contiguous page to the previous one
3023 * @size: portion of page that we want to write
3024 * @offset: starting offset in the page
3025 * @bio_ret: must be valid pointer, newly allocated bio will be stored there
3026 * @end_io_func: end_io callback for new bio
3027 * @mirror_num: desired mirror to read/write
3028 * @prev_bio_flags: flags of previous bio to see if we can merge the current one
3029 * @bio_flags: flags of the current bio to see if we can merge them
3031 static int submit_extent_page(unsigned int opf,
3032 struct writeback_control *wbc,
3033 struct page *page, u64 offset,
3034 size_t size, unsigned long pg_offset,
3035 struct bio **bio_ret,
3036 bio_end_io_t end_io_func,
3038 unsigned long prev_bio_flags,
3039 unsigned long bio_flags,
3040 bool force_bio_submit)
3044 size_t page_size = min_t(size_t, size, PAGE_SIZE);
3045 sector_t sector = offset >> 9;
3046 struct extent_io_tree *tree = &BTRFS_I(page->mapping->host)->io_tree;
3052 bool can_merge = true;
3055 if (prev_bio_flags & EXTENT_BIO_COMPRESSED)
3056 contig = bio->bi_iter.bi_sector == sector;
3058 contig = bio_end_sector(bio) == sector;
3061 if (btrfs_bio_fits_in_stripe(page, page_size, bio, bio_flags))
3064 if (prev_bio_flags != bio_flags || !contig || !can_merge ||
3066 bio_add_page(bio, page, page_size, pg_offset) < page_size) {
3067 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
3075 wbc_account_cgroup_owner(wbc, page, page_size);
3080 bio = btrfs_bio_alloc(offset);
3081 bio_add_page(bio, page, page_size, pg_offset);
3082 bio->bi_end_io = end_io_func;
3083 bio->bi_private = tree;
3084 bio->bi_write_hint = page->mapping->host->i_write_hint;
3087 struct block_device *bdev;
3089 bdev = BTRFS_I(page->mapping->host)->root->fs_info->fs_devices->latest_bdev;
3090 bio_set_dev(bio, bdev);
3091 wbc_init_bio(wbc, bio);
3092 wbc_account_cgroup_owner(wbc, page, page_size);
3100 static void attach_extent_buffer_page(struct extent_buffer *eb,
3103 if (!PagePrivate(page))
3104 attach_page_private(page, eb);
3106 WARN_ON(page->private != (unsigned long)eb);
3109 void set_page_extent_mapped(struct page *page)
3111 if (!PagePrivate(page))
3112 attach_page_private(page, (void *)EXTENT_PAGE_PRIVATE);
3115 static struct extent_map *
3116 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
3117 u64 start, u64 len, get_extent_t *get_extent,
3118 struct extent_map **em_cached)
3120 struct extent_map *em;
3122 if (em_cached && *em_cached) {
3124 if (extent_map_in_tree(em) && start >= em->start &&
3125 start < extent_map_end(em)) {
3126 refcount_inc(&em->refs);
3130 free_extent_map(em);
3134 em = get_extent(BTRFS_I(inode), page, pg_offset, start, len);
3135 if (em_cached && !IS_ERR_OR_NULL(em)) {
3137 refcount_inc(&em->refs);
3143 * basic readpage implementation. Locked extent state structs are inserted
3144 * into the tree that are removed when the IO is done (by the end_io
3146 * XXX JDM: This needs looking at to ensure proper page locking
3147 * return 0 on success, otherwise return error
3149 static int __do_readpage(struct page *page,
3150 get_extent_t *get_extent,
3151 struct extent_map **em_cached,
3152 struct bio **bio, int mirror_num,
3153 unsigned long *bio_flags, unsigned int read_flags,
3156 struct inode *inode = page->mapping->host;
3157 u64 start = page_offset(page);
3158 const u64 end = start + PAGE_SIZE - 1;
3161 u64 last_byte = i_size_read(inode);
3164 struct extent_map *em;
3167 size_t pg_offset = 0;
3169 size_t disk_io_size;
3170 size_t blocksize = inode->i_sb->s_blocksize;
3171 unsigned long this_bio_flag = 0;
3172 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
3174 set_page_extent_mapped(page);
3176 if (!PageUptodate(page)) {
3177 if (cleancache_get_page(page) == 0) {
3178 BUG_ON(blocksize != PAGE_SIZE);
3179 unlock_extent(tree, start, end);
3184 if (page->index == last_byte >> PAGE_SHIFT) {
3186 size_t zero_offset = offset_in_page(last_byte);
3189 iosize = PAGE_SIZE - zero_offset;
3190 userpage = kmap_atomic(page);
3191 memset(userpage + zero_offset, 0, iosize);
3192 flush_dcache_page(page);
3193 kunmap_atomic(userpage);
3196 while (cur <= end) {
3197 bool force_bio_submit = false;
3200 if (cur >= last_byte) {
3202 struct extent_state *cached = NULL;
3204 iosize = PAGE_SIZE - pg_offset;
3205 userpage = kmap_atomic(page);
3206 memset(userpage + pg_offset, 0, iosize);
3207 flush_dcache_page(page);
3208 kunmap_atomic(userpage);
3209 set_extent_uptodate(tree, cur, cur + iosize - 1,
3211 unlock_extent_cached(tree, cur,
3212 cur + iosize - 1, &cached);
3215 em = __get_extent_map(inode, page, pg_offset, cur,
3216 end - cur + 1, get_extent, em_cached);
3217 if (IS_ERR_OR_NULL(em)) {
3219 unlock_extent(tree, cur, end);
3222 extent_offset = cur - em->start;
3223 BUG_ON(extent_map_end(em) <= cur);
3226 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
3227 this_bio_flag |= EXTENT_BIO_COMPRESSED;
3228 extent_set_compress_type(&this_bio_flag,
3232 iosize = min(extent_map_end(em) - cur, end - cur + 1);
3233 cur_end = min(extent_map_end(em) - 1, end);
3234 iosize = ALIGN(iosize, blocksize);
3235 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
3236 disk_io_size = em->block_len;
3237 offset = em->block_start;
3239 offset = em->block_start + extent_offset;
3240 disk_io_size = iosize;
3242 block_start = em->block_start;
3243 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
3244 block_start = EXTENT_MAP_HOLE;
3247 * If we have a file range that points to a compressed extent
3248 * and it's followed by a consecutive file range that points to
3249 * to the same compressed extent (possibly with a different
3250 * offset and/or length, so it either points to the whole extent
3251 * or only part of it), we must make sure we do not submit a
3252 * single bio to populate the pages for the 2 ranges because
3253 * this makes the compressed extent read zero out the pages
3254 * belonging to the 2nd range. Imagine the following scenario:
3257 * [0 - 8K] [8K - 24K]
3260 * points to extent X, points to extent X,
3261 * offset 4K, length of 8K offset 0, length 16K
3263 * [extent X, compressed length = 4K uncompressed length = 16K]
3265 * If the bio to read the compressed extent covers both ranges,
3266 * it will decompress extent X into the pages belonging to the
3267 * first range and then it will stop, zeroing out the remaining
3268 * pages that belong to the other range that points to extent X.
3269 * So here we make sure we submit 2 bios, one for the first
3270 * range and another one for the third range. Both will target
3271 * the same physical extent from disk, but we can't currently
3272 * make the compressed bio endio callback populate the pages
3273 * for both ranges because each compressed bio is tightly
3274 * coupled with a single extent map, and each range can have
3275 * an extent map with a different offset value relative to the
3276 * uncompressed data of our extent and different lengths. This
3277 * is a corner case so we prioritize correctness over
3278 * non-optimal behavior (submitting 2 bios for the same extent).
3280 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3281 prev_em_start && *prev_em_start != (u64)-1 &&
3282 *prev_em_start != em->start)
3283 force_bio_submit = true;
3286 *prev_em_start = em->start;
3288 free_extent_map(em);
3291 /* we've found a hole, just zero and go on */
3292 if (block_start == EXTENT_MAP_HOLE) {
3294 struct extent_state *cached = NULL;
3296 userpage = kmap_atomic(page);
3297 memset(userpage + pg_offset, 0, iosize);
3298 flush_dcache_page(page);
3299 kunmap_atomic(userpage);
3301 set_extent_uptodate(tree, cur, cur + iosize - 1,
3303 unlock_extent_cached(tree, cur,
3304 cur + iosize - 1, &cached);
3306 pg_offset += iosize;
3309 /* the get_extent function already copied into the page */
3310 if (test_range_bit(tree, cur, cur_end,
3311 EXTENT_UPTODATE, 1, NULL)) {
3312 check_page_uptodate(tree, page);
3313 unlock_extent(tree, cur, cur + iosize - 1);
3315 pg_offset += iosize;
3318 /* we have an inline extent but it didn't get marked up
3319 * to date. Error out
3321 if (block_start == EXTENT_MAP_INLINE) {
3323 unlock_extent(tree, cur, cur + iosize - 1);
3325 pg_offset += iosize;
3329 ret = submit_extent_page(REQ_OP_READ | read_flags, NULL,
3330 page, offset, disk_io_size,
3332 end_bio_extent_readpage, mirror_num,
3338 *bio_flags = this_bio_flag;
3341 unlock_extent(tree, cur, cur + iosize - 1);
3345 pg_offset += iosize;
3349 if (!PageError(page))
3350 SetPageUptodate(page);
3356 static inline void contiguous_readpages(struct page *pages[], int nr_pages,
3358 struct extent_map **em_cached,
3360 unsigned long *bio_flags,
3363 struct btrfs_inode *inode = BTRFS_I(pages[0]->mapping->host);
3366 btrfs_lock_and_flush_ordered_range(inode, start, end, NULL);
3368 for (index = 0; index < nr_pages; index++) {
3369 __do_readpage(pages[index], btrfs_get_extent, em_cached,
3370 bio, 0, bio_flags, REQ_RAHEAD, prev_em_start);
3371 put_page(pages[index]);
3375 static int __extent_read_full_page(struct page *page,
3376 get_extent_t *get_extent,
3377 struct bio **bio, int mirror_num,
3378 unsigned long *bio_flags,
3379 unsigned int read_flags)
3381 struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
3382 u64 start = page_offset(page);
3383 u64 end = start + PAGE_SIZE - 1;
3386 btrfs_lock_and_flush_ordered_range(inode, start, end, NULL);
3388 ret = __do_readpage(page, get_extent, NULL, bio, mirror_num,
3389 bio_flags, read_flags, NULL);
3393 int extent_read_full_page(struct page *page, get_extent_t *get_extent,
3396 struct bio *bio = NULL;
3397 unsigned long bio_flags = 0;
3400 ret = __extent_read_full_page(page, get_extent, &bio, mirror_num,
3403 ret = submit_one_bio(bio, mirror_num, bio_flags);
3407 static void update_nr_written(struct writeback_control *wbc,
3408 unsigned long nr_written)
3410 wbc->nr_to_write -= nr_written;
3414 * helper for __extent_writepage, doing all of the delayed allocation setup.
3416 * This returns 1 if btrfs_run_delalloc_range function did all the work required
3417 * to write the page (copy into inline extent). In this case the IO has
3418 * been started and the page is already unlocked.
3420 * This returns 0 if all went well (page still locked)
3421 * This returns < 0 if there were errors (page still locked)
3423 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3424 struct page *page, struct writeback_control *wbc,
3425 u64 delalloc_start, unsigned long *nr_written)
3427 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3429 u64 delalloc_to_write = 0;
3430 u64 delalloc_end = 0;
3432 int page_started = 0;
3435 while (delalloc_end < page_end) {
3436 found = find_lock_delalloc_range(inode, page,
3440 delalloc_start = delalloc_end + 1;
3443 ret = btrfs_run_delalloc_range(inode, page, delalloc_start,
3444 delalloc_end, &page_started, nr_written, wbc);
3448 * btrfs_run_delalloc_range should return < 0 for error
3449 * but just in case, we use > 0 here meaning the IO is
3450 * started, so we don't want to return > 0 unless
3451 * things are going well.
3453 ret = ret < 0 ? ret : -EIO;
3457 * delalloc_end is already one less than the total length, so
3458 * we don't subtract one from PAGE_SIZE
3460 delalloc_to_write += (delalloc_end - delalloc_start +
3461 PAGE_SIZE) >> PAGE_SHIFT;
3462 delalloc_start = delalloc_end + 1;
3464 if (wbc->nr_to_write < delalloc_to_write) {
3467 if (delalloc_to_write < thresh * 2)
3468 thresh = delalloc_to_write;
3469 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3473 /* did the fill delalloc function already unlock and start
3478 * we've unlocked the page, so we can't update
3479 * the mapping's writeback index, just update
3482 wbc->nr_to_write -= *nr_written;
3493 * helper for __extent_writepage. This calls the writepage start hooks,
3494 * and does the loop to map the page into extents and bios.
3496 * We return 1 if the IO is started and the page is unlocked,
3497 * 0 if all went well (page still locked)
3498 * < 0 if there were errors (page still locked)
3500 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3502 struct writeback_control *wbc,
3503 struct extent_page_data *epd,
3505 unsigned long nr_written,
3508 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
3509 u64 start = page_offset(page);
3510 u64 page_end = start + PAGE_SIZE - 1;
3516 struct extent_map *em;
3517 size_t pg_offset = 0;
3521 const unsigned int write_flags = wbc_to_write_flags(wbc);
3524 ret = btrfs_writepage_cow_fixup(page, start, page_end);
3526 /* Fixup worker will requeue */
3527 redirty_page_for_writepage(wbc, page);
3528 update_nr_written(wbc, nr_written);
3534 * we don't want to touch the inode after unlocking the page,
3535 * so we update the mapping writeback index now
3537 update_nr_written(wbc, nr_written + 1);
3540 blocksize = inode->i_sb->s_blocksize;
3542 while (cur <= end) {
3546 if (cur >= i_size) {
3547 btrfs_writepage_endio_finish_ordered(page, cur,
3551 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur,
3553 if (IS_ERR_OR_NULL(em)) {
3555 ret = PTR_ERR_OR_ZERO(em);
3559 extent_offset = cur - em->start;
3560 em_end = extent_map_end(em);
3561 BUG_ON(em_end <= cur);
3563 iosize = min(em_end - cur, end - cur + 1);
3564 iosize = ALIGN(iosize, blocksize);
3565 offset = em->block_start + extent_offset;
3566 block_start = em->block_start;
3567 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3568 free_extent_map(em);
3572 * compressed and inline extents are written through other
3575 if (compressed || block_start == EXTENT_MAP_HOLE ||
3576 block_start == EXTENT_MAP_INLINE) {
3580 btrfs_writepage_endio_finish_ordered(page, cur,
3581 cur + iosize - 1, 1);
3583 pg_offset += iosize;
3587 btrfs_set_range_writeback(tree, cur, cur + iosize - 1);
3588 if (!PageWriteback(page)) {
3589 btrfs_err(BTRFS_I(inode)->root->fs_info,
3590 "page %lu not writeback, cur %llu end %llu",
3591 page->index, cur, end);
3594 ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
3595 page, offset, iosize, pg_offset,
3597 end_bio_extent_writepage,
3601 if (PageWriteback(page))
3602 end_page_writeback(page);
3606 pg_offset += iosize;
3614 * the writepage semantics are similar to regular writepage. extent
3615 * records are inserted to lock ranges in the tree, and as dirty areas
3616 * are found, they are marked writeback. Then the lock bits are removed
3617 * and the end_io handler clears the writeback ranges
3619 * Return 0 if everything goes well.
3620 * Return <0 for error.
3622 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3623 struct extent_page_data *epd)
3625 struct inode *inode = page->mapping->host;
3626 u64 start = page_offset(page);
3627 u64 page_end = start + PAGE_SIZE - 1;
3631 loff_t i_size = i_size_read(inode);
3632 unsigned long end_index = i_size >> PAGE_SHIFT;
3633 unsigned long nr_written = 0;
3635 trace___extent_writepage(page, inode, wbc);
3637 WARN_ON(!PageLocked(page));
3639 ClearPageError(page);
3641 pg_offset = offset_in_page(i_size);
3642 if (page->index > end_index ||
3643 (page->index == end_index && !pg_offset)) {
3644 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3649 if (page->index == end_index) {
3652 userpage = kmap_atomic(page);
3653 memset(userpage + pg_offset, 0,
3654 PAGE_SIZE - pg_offset);
3655 kunmap_atomic(userpage);
3656 flush_dcache_page(page);
3659 set_page_extent_mapped(page);
3661 if (!epd->extent_locked) {
3662 ret = writepage_delalloc(inode, page, wbc, start, &nr_written);
3669 ret = __extent_writepage_io(inode, page, wbc, epd,
3670 i_size, nr_written, &nr);
3676 /* make sure the mapping tag for page dirty gets cleared */
3677 set_page_writeback(page);
3678 end_page_writeback(page);
3680 if (PageError(page)) {
3681 ret = ret < 0 ? ret : -EIO;
3682 end_extent_writepage(page, ret, start, page_end);
3689 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3691 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3692 TASK_UNINTERRUPTIBLE);
3695 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3697 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3698 smp_mb__after_atomic();
3699 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3703 * Lock eb pages and flush the bio if we can't the locks
3705 * Return 0 if nothing went wrong
3706 * Return >0 is same as 0, except bio is not submitted
3707 * Return <0 if something went wrong, no page is locked
3709 static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb,
3710 struct extent_page_data *epd)
3712 struct btrfs_fs_info *fs_info = eb->fs_info;
3713 int i, num_pages, failed_page_nr;
3717 if (!btrfs_try_tree_write_lock(eb)) {
3718 ret = flush_write_bio(epd);
3722 btrfs_tree_lock(eb);
3725 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3726 btrfs_tree_unlock(eb);
3730 ret = flush_write_bio(epd);
3736 wait_on_extent_buffer_writeback(eb);
3737 btrfs_tree_lock(eb);
3738 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3740 btrfs_tree_unlock(eb);
3745 * We need to do this to prevent races in people who check if the eb is
3746 * under IO since we can end up having no IO bits set for a short period
3749 spin_lock(&eb->refs_lock);
3750 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3751 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3752 spin_unlock(&eb->refs_lock);
3753 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3754 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
3756 fs_info->dirty_metadata_batch);
3759 spin_unlock(&eb->refs_lock);
3762 btrfs_tree_unlock(eb);
3767 num_pages = num_extent_pages(eb);
3768 for (i = 0; i < num_pages; i++) {
3769 struct page *p = eb->pages[i];
3771 if (!trylock_page(p)) {
3775 err = flush_write_bio(epd);
3789 /* Unlock already locked pages */
3790 for (i = 0; i < failed_page_nr; i++)
3791 unlock_page(eb->pages[i]);
3793 * Clear EXTENT_BUFFER_WRITEBACK and wake up anyone waiting on it.
3794 * Also set back EXTENT_BUFFER_DIRTY so future attempts to this eb can
3795 * be made and undo everything done before.
3797 btrfs_tree_lock(eb);
3798 spin_lock(&eb->refs_lock);
3799 set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3800 end_extent_buffer_writeback(eb);
3801 spin_unlock(&eb->refs_lock);
3802 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, eb->len,
3803 fs_info->dirty_metadata_batch);
3804 btrfs_clear_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3805 btrfs_tree_unlock(eb);
3809 static void set_btree_ioerr(struct page *page)
3811 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3812 struct btrfs_fs_info *fs_info;
3815 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3819 * If we error out, we should add back the dirty_metadata_bytes
3820 * to make it consistent.
3822 fs_info = eb->fs_info;
3823 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
3824 eb->len, fs_info->dirty_metadata_batch);
3827 * If writeback for a btree extent that doesn't belong to a log tree
3828 * failed, increment the counter transaction->eb_write_errors.
3829 * We do this because while the transaction is running and before it's
3830 * committing (when we call filemap_fdata[write|wait]_range against
3831 * the btree inode), we might have
3832 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3833 * returns an error or an error happens during writeback, when we're
3834 * committing the transaction we wouldn't know about it, since the pages
3835 * can be no longer dirty nor marked anymore for writeback (if a
3836 * subsequent modification to the extent buffer didn't happen before the
3837 * transaction commit), which makes filemap_fdata[write|wait]_range not
3838 * able to find the pages tagged with SetPageError at transaction
3839 * commit time. So if this happens we must abort the transaction,
3840 * otherwise we commit a super block with btree roots that point to
3841 * btree nodes/leafs whose content on disk is invalid - either garbage
3842 * or the content of some node/leaf from a past generation that got
3843 * cowed or deleted and is no longer valid.
3845 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3846 * not be enough - we need to distinguish between log tree extents vs
3847 * non-log tree extents, and the next filemap_fdatawait_range() call
3848 * will catch and clear such errors in the mapping - and that call might
3849 * be from a log sync and not from a transaction commit. Also, checking
3850 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3851 * not done and would not be reliable - the eb might have been released
3852 * from memory and reading it back again means that flag would not be
3853 * set (since it's a runtime flag, not persisted on disk).
3855 * Using the flags below in the btree inode also makes us achieve the
3856 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3857 * writeback for all dirty pages and before filemap_fdatawait_range()
3858 * is called, the writeback for all dirty pages had already finished
3859 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3860 * filemap_fdatawait_range() would return success, as it could not know
3861 * that writeback errors happened (the pages were no longer tagged for
3864 switch (eb->log_index) {
3866 set_bit(BTRFS_FS_BTREE_ERR, &eb->fs_info->flags);
3869 set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags);
3872 set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags);
3875 BUG(); /* unexpected, logic error */
3879 static void end_bio_extent_buffer_writepage(struct bio *bio)
3881 struct bio_vec *bvec;
3882 struct extent_buffer *eb;
3884 struct bvec_iter_all iter_all;
3886 ASSERT(!bio_flagged(bio, BIO_CLONED));
3887 bio_for_each_segment_all(bvec, bio, iter_all) {
3888 struct page *page = bvec->bv_page;
3890 eb = (struct extent_buffer *)page->private;
3892 done = atomic_dec_and_test(&eb->io_pages);
3894 if (bio->bi_status ||
3895 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3896 ClearPageUptodate(page);
3897 set_btree_ioerr(page);
3900 end_page_writeback(page);
3905 end_extent_buffer_writeback(eb);
3911 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3912 struct writeback_control *wbc,
3913 struct extent_page_data *epd)
3915 u64 offset = eb->start;
3918 unsigned long start, end;
3919 unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META;
3922 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3923 num_pages = num_extent_pages(eb);
3924 atomic_set(&eb->io_pages, num_pages);
3926 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3927 nritems = btrfs_header_nritems(eb);
3928 if (btrfs_header_level(eb) > 0) {
3929 end = btrfs_node_key_ptr_offset(nritems);
3931 memzero_extent_buffer(eb, end, eb->len - end);
3935 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3937 start = btrfs_item_nr_offset(nritems);
3938 end = BTRFS_LEAF_DATA_OFFSET + leaf_data_end(eb);
3939 memzero_extent_buffer(eb, start, end - start);
3942 for (i = 0; i < num_pages; i++) {
3943 struct page *p = eb->pages[i];
3945 clear_page_dirty_for_io(p);
3946 set_page_writeback(p);
3947 ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
3948 p, offset, PAGE_SIZE, 0,
3950 end_bio_extent_buffer_writepage,
3954 if (PageWriteback(p))
3955 end_page_writeback(p);
3956 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3957 end_extent_buffer_writeback(eb);
3961 offset += PAGE_SIZE;
3962 update_nr_written(wbc, 1);
3966 if (unlikely(ret)) {
3967 for (; i < num_pages; i++) {
3968 struct page *p = eb->pages[i];
3969 clear_page_dirty_for_io(p);
3977 int btree_write_cache_pages(struct address_space *mapping,
3978 struct writeback_control *wbc)
3980 struct extent_buffer *eb, *prev_eb = NULL;
3981 struct extent_page_data epd = {
3984 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3986 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3989 int nr_to_write_done = 0;
3990 struct pagevec pvec;
3993 pgoff_t end; /* Inclusive */
3997 pagevec_init(&pvec);
3998 if (wbc->range_cyclic) {
3999 index = mapping->writeback_index; /* Start from prev offset */
4002 * Start from the beginning does not need to cycle over the
4003 * range, mark it as scanned.
4005 scanned = (index == 0);
4007 index = wbc->range_start >> PAGE_SHIFT;
4008 end = wbc->range_end >> PAGE_SHIFT;
4011 if (wbc->sync_mode == WB_SYNC_ALL)
4012 tag = PAGECACHE_TAG_TOWRITE;
4014 tag = PAGECACHE_TAG_DIRTY;
4016 if (wbc->sync_mode == WB_SYNC_ALL)
4017 tag_pages_for_writeback(mapping, index, end);
4018 while (!done && !nr_to_write_done && (index <= end) &&
4019 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
4023 for (i = 0; i < nr_pages; i++) {
4024 struct page *page = pvec.pages[i];
4026 if (!PagePrivate(page))
4029 spin_lock(&mapping->private_lock);
4030 if (!PagePrivate(page)) {
4031 spin_unlock(&mapping->private_lock);
4035 eb = (struct extent_buffer *)page->private;
4038 * Shouldn't happen and normally this would be a BUG_ON
4039 * but no sense in crashing the users box for something
4040 * we can survive anyway.
4043 spin_unlock(&mapping->private_lock);
4047 if (eb == prev_eb) {
4048 spin_unlock(&mapping->private_lock);
4052 ret = atomic_inc_not_zero(&eb->refs);
4053 spin_unlock(&mapping->private_lock);
4058 ret = lock_extent_buffer_for_io(eb, &epd);
4060 free_extent_buffer(eb);
4062 } else if (ret < 0) {
4064 free_extent_buffer(eb);
4068 ret = write_one_eb(eb, wbc, &epd);
4071 free_extent_buffer(eb);
4074 free_extent_buffer(eb);
4077 * the filesystem may choose to bump up nr_to_write.
4078 * We have to make sure to honor the new nr_to_write
4081 nr_to_write_done = wbc->nr_to_write <= 0;
4083 pagevec_release(&pvec);
4086 if (!scanned && !done) {
4088 * We hit the last page and there is more work to be done: wrap
4089 * back to the start of the file
4097 end_write_bio(&epd, ret);
4101 * If something went wrong, don't allow any metadata write bio to be
4104 * This would prevent use-after-free if we had dirty pages not
4105 * cleaned up, which can still happen by fuzzed images.
4108 * Allowing existing tree block to be allocated for other trees.
4110 * - Log tree operations
4111 * Exiting tree blocks get allocated to log tree, bumps its
4112 * generation, then get cleaned in tree re-balance.
4113 * Such tree block will not be written back, since it's clean,
4114 * thus no WRITTEN flag set.
4115 * And after log writes back, this tree block is not traced by
4116 * any dirty extent_io_tree.
4118 * - Offending tree block gets re-dirtied from its original owner
4119 * Since it has bumped generation, no WRITTEN flag, it can be
4120 * reused without COWing. This tree block will not be traced
4121 * by btrfs_transaction::dirty_pages.
4123 * Now such dirty tree block will not be cleaned by any dirty
4124 * extent io tree. Thus we don't want to submit such wild eb
4125 * if the fs already has error.
4127 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
4128 ret = flush_write_bio(&epd);
4131 end_write_bio(&epd, ret);
4137 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
4138 * @mapping: address space structure to write
4139 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
4140 * @data: data passed to __extent_writepage function
4142 * If a page is already under I/O, write_cache_pages() skips it, even
4143 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
4144 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
4145 * and msync() need to guarantee that all the data which was dirty at the time
4146 * the call was made get new I/O started against them. If wbc->sync_mode is
4147 * WB_SYNC_ALL then we were called for data integrity and we must wait for
4148 * existing IO to complete.
4150 static int extent_write_cache_pages(struct address_space *mapping,
4151 struct writeback_control *wbc,
4152 struct extent_page_data *epd)
4154 struct inode *inode = mapping->host;
4157 int nr_to_write_done = 0;
4158 struct pagevec pvec;
4161 pgoff_t end; /* Inclusive */
4163 int range_whole = 0;
4168 * We have to hold onto the inode so that ordered extents can do their
4169 * work when the IO finishes. The alternative to this is failing to add
4170 * an ordered extent if the igrab() fails there and that is a huge pain
4171 * to deal with, so instead just hold onto the inode throughout the
4172 * writepages operation. If it fails here we are freeing up the inode
4173 * anyway and we'd rather not waste our time writing out stuff that is
4174 * going to be truncated anyway.
4179 pagevec_init(&pvec);
4180 if (wbc->range_cyclic) {
4181 index = mapping->writeback_index; /* Start from prev offset */
4184 * Start from the beginning does not need to cycle over the
4185 * range, mark it as scanned.
4187 scanned = (index == 0);
4189 index = wbc->range_start >> PAGE_SHIFT;
4190 end = wbc->range_end >> PAGE_SHIFT;
4191 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
4197 * We do the tagged writepage as long as the snapshot flush bit is set
4198 * and we are the first one who do the filemap_flush() on this inode.
4200 * The nr_to_write == LONG_MAX is needed to make sure other flushers do
4201 * not race in and drop the bit.
4203 if (range_whole && wbc->nr_to_write == LONG_MAX &&
4204 test_and_clear_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
4205 &BTRFS_I(inode)->runtime_flags))
4206 wbc->tagged_writepages = 1;
4208 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
4209 tag = PAGECACHE_TAG_TOWRITE;
4211 tag = PAGECACHE_TAG_DIRTY;
4213 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
4214 tag_pages_for_writeback(mapping, index, end);
4216 while (!done && !nr_to_write_done && (index <= end) &&
4217 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping,
4218 &index, end, tag))) {
4221 for (i = 0; i < nr_pages; i++) {
4222 struct page *page = pvec.pages[i];
4224 done_index = page->index + 1;
4226 * At this point we hold neither the i_pages lock nor
4227 * the page lock: the page may be truncated or
4228 * invalidated (changing page->mapping to NULL),
4229 * or even swizzled back from swapper_space to
4230 * tmpfs file mapping
4232 if (!trylock_page(page)) {
4233 ret = flush_write_bio(epd);
4238 if (unlikely(page->mapping != mapping)) {
4243 if (wbc->sync_mode != WB_SYNC_NONE) {
4244 if (PageWriteback(page)) {
4245 ret = flush_write_bio(epd);
4248 wait_on_page_writeback(page);
4251 if (PageWriteback(page) ||
4252 !clear_page_dirty_for_io(page)) {
4257 ret = __extent_writepage(page, wbc, epd);
4264 * the filesystem may choose to bump up nr_to_write.
4265 * We have to make sure to honor the new nr_to_write
4268 nr_to_write_done = wbc->nr_to_write <= 0;
4270 pagevec_release(&pvec);
4273 if (!scanned && !done) {
4275 * We hit the last page and there is more work to be done: wrap
4276 * back to the start of the file
4282 * If we're looping we could run into a page that is locked by a
4283 * writer and that writer could be waiting on writeback for a
4284 * page in our current bio, and thus deadlock, so flush the
4287 ret = flush_write_bio(epd);
4292 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4293 mapping->writeback_index = done_index;
4295 btrfs_add_delayed_iput(inode);
4299 int extent_write_full_page(struct page *page, struct writeback_control *wbc)
4302 struct extent_page_data epd = {
4305 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4308 ret = __extent_writepage(page, wbc, &epd);
4311 end_write_bio(&epd, ret);
4315 ret = flush_write_bio(&epd);
4320 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
4324 struct address_space *mapping = inode->i_mapping;
4326 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4329 struct extent_page_data epd = {
4332 .sync_io = mode == WB_SYNC_ALL,
4334 struct writeback_control wbc_writepages = {
4336 .nr_to_write = nr_pages * 2,
4337 .range_start = start,
4338 .range_end = end + 1,
4339 /* We're called from an async helper function */
4340 .punt_to_cgroup = 1,
4341 .no_cgroup_owner = 1,
4344 wbc_attach_fdatawrite_inode(&wbc_writepages, inode);
4345 while (start <= end) {
4346 page = find_get_page(mapping, start >> PAGE_SHIFT);
4347 if (clear_page_dirty_for_io(page))
4348 ret = __extent_writepage(page, &wbc_writepages, &epd);
4350 btrfs_writepage_endio_finish_ordered(page, start,
4351 start + PAGE_SIZE - 1, 1);
4360 ret = flush_write_bio(&epd);
4362 end_write_bio(&epd, ret);
4364 wbc_detach_inode(&wbc_writepages);
4368 int extent_writepages(struct address_space *mapping,
4369 struct writeback_control *wbc)
4372 struct extent_page_data epd = {
4375 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4378 ret = extent_write_cache_pages(mapping, wbc, &epd);
4381 end_write_bio(&epd, ret);
4384 ret = flush_write_bio(&epd);
4388 void extent_readahead(struct readahead_control *rac)
4390 struct bio *bio = NULL;
4391 unsigned long bio_flags = 0;
4392 struct page *pagepool[16];
4393 struct extent_map *em_cached = NULL;
4394 u64 prev_em_start = (u64)-1;
4397 while ((nr = readahead_page_batch(rac, pagepool))) {
4398 u64 contig_start = page_offset(pagepool[0]);
4399 u64 contig_end = page_offset(pagepool[nr - 1]) + PAGE_SIZE - 1;
4401 ASSERT(contig_start + nr * PAGE_SIZE - 1 == contig_end);
4403 contiguous_readpages(pagepool, nr, contig_start, contig_end,
4404 &em_cached, &bio, &bio_flags, &prev_em_start);
4408 free_extent_map(em_cached);
4411 if (submit_one_bio(bio, 0, bio_flags))
4417 * basic invalidatepage code, this waits on any locked or writeback
4418 * ranges corresponding to the page, and then deletes any extent state
4419 * records from the tree
4421 int extent_invalidatepage(struct extent_io_tree *tree,
4422 struct page *page, unsigned long offset)
4424 struct extent_state *cached_state = NULL;
4425 u64 start = page_offset(page);
4426 u64 end = start + PAGE_SIZE - 1;
4427 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4429 start += ALIGN(offset, blocksize);
4433 lock_extent_bits(tree, start, end, &cached_state);
4434 wait_on_page_writeback(page);
4435 clear_extent_bit(tree, start, end, EXTENT_LOCKED | EXTENT_DELALLOC |
4436 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state);
4441 * a helper for releasepage, this tests for areas of the page that
4442 * are locked or under IO and drops the related state bits if it is safe
4445 static int try_release_extent_state(struct extent_io_tree *tree,
4446 struct page *page, gfp_t mask)
4448 u64 start = page_offset(page);
4449 u64 end = start + PAGE_SIZE - 1;
4452 if (test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL)) {
4456 * at this point we can safely clear everything except the
4457 * locked bit and the nodatasum bit
4459 ret = __clear_extent_bit(tree, start, end,
4460 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4461 0, 0, NULL, mask, NULL);
4463 /* if clear_extent_bit failed for enomem reasons,
4464 * we can't allow the release to continue.
4475 * a helper for releasepage. As long as there are no locked extents
4476 * in the range corresponding to the page, both state records and extent
4477 * map records are removed
4479 int try_release_extent_mapping(struct page *page, gfp_t mask)
4481 struct extent_map *em;
4482 u64 start = page_offset(page);
4483 u64 end = start + PAGE_SIZE - 1;
4484 struct btrfs_inode *btrfs_inode = BTRFS_I(page->mapping->host);
4485 struct extent_io_tree *tree = &btrfs_inode->io_tree;
4486 struct extent_map_tree *map = &btrfs_inode->extent_tree;
4488 if (gfpflags_allow_blocking(mask) &&
4489 page->mapping->host->i_size > SZ_16M) {
4491 while (start <= end) {
4492 len = end - start + 1;
4493 write_lock(&map->lock);
4494 em = lookup_extent_mapping(map, start, len);
4496 write_unlock(&map->lock);
4499 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4500 em->start != start) {
4501 write_unlock(&map->lock);
4502 free_extent_map(em);
4505 if (!test_range_bit(tree, em->start,
4506 extent_map_end(em) - 1,
4507 EXTENT_LOCKED, 0, NULL)) {
4508 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4509 &btrfs_inode->runtime_flags);
4510 remove_extent_mapping(map, em);
4511 /* once for the rb tree */
4512 free_extent_map(em);
4514 start = extent_map_end(em);
4515 write_unlock(&map->lock);
4518 free_extent_map(em);
4520 cond_resched(); /* Allow large-extent preemption. */
4523 return try_release_extent_state(tree, page, mask);
4527 * helper function for fiemap, which doesn't want to see any holes.
4528 * This maps until we find something past 'last'
4530 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4531 u64 offset, u64 last)
4533 u64 sectorsize = btrfs_inode_sectorsize(inode);
4534 struct extent_map *em;
4541 len = last - offset;
4544 len = ALIGN(len, sectorsize);
4545 em = btrfs_get_extent_fiemap(BTRFS_I(inode), offset, len);
4546 if (IS_ERR_OR_NULL(em))
4549 /* if this isn't a hole return it */
4550 if (em->block_start != EXTENT_MAP_HOLE)
4553 /* this is a hole, advance to the next extent */
4554 offset = extent_map_end(em);
4555 free_extent_map(em);
4563 * To cache previous fiemap extent
4565 * Will be used for merging fiemap extent
4567 struct fiemap_cache {
4576 * Helper to submit fiemap extent.
4578 * Will try to merge current fiemap extent specified by @offset, @phys,
4579 * @len and @flags with cached one.
4580 * And only when we fails to merge, cached one will be submitted as
4583 * Return value is the same as fiemap_fill_next_extent().
4585 static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
4586 struct fiemap_cache *cache,
4587 u64 offset, u64 phys, u64 len, u32 flags)
4595 * Sanity check, extent_fiemap() should have ensured that new
4596 * fiemap extent won't overlap with cached one.
4599 * NOTE: Physical address can overlap, due to compression
4601 if (cache->offset + cache->len > offset) {
4607 * Only merges fiemap extents if
4608 * 1) Their logical addresses are continuous
4610 * 2) Their physical addresses are continuous
4611 * So truly compressed (physical size smaller than logical size)
4612 * extents won't get merged with each other
4614 * 3) Share same flags except FIEMAP_EXTENT_LAST
4615 * So regular extent won't get merged with prealloc extent
4617 if (cache->offset + cache->len == offset &&
4618 cache->phys + cache->len == phys &&
4619 (cache->flags & ~FIEMAP_EXTENT_LAST) ==
4620 (flags & ~FIEMAP_EXTENT_LAST)) {
4622 cache->flags |= flags;
4623 goto try_submit_last;
4626 /* Not mergeable, need to submit cached one */
4627 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4628 cache->len, cache->flags);
4629 cache->cached = false;
4633 cache->cached = true;
4634 cache->offset = offset;
4637 cache->flags = flags;
4639 if (cache->flags & FIEMAP_EXTENT_LAST) {
4640 ret = fiemap_fill_next_extent(fieinfo, cache->offset,
4641 cache->phys, cache->len, cache->flags);
4642 cache->cached = false;
4648 * Emit last fiemap cache
4650 * The last fiemap cache may still be cached in the following case:
4652 * |<- Fiemap range ->|
4653 * |<------------ First extent ----------->|
4655 * In this case, the first extent range will be cached but not emitted.
4656 * So we must emit it before ending extent_fiemap().
4658 static int emit_last_fiemap_cache(struct fiemap_extent_info *fieinfo,
4659 struct fiemap_cache *cache)
4666 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4667 cache->len, cache->flags);
4668 cache->cached = false;
4674 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4675 __u64 start, __u64 len)
4679 u64 max = start + len;
4683 u64 last_for_get_extent = 0;
4685 u64 isize = i_size_read(inode);
4686 struct btrfs_key found_key;
4687 struct extent_map *em = NULL;
4688 struct extent_state *cached_state = NULL;
4689 struct btrfs_path *path;
4690 struct btrfs_root *root = BTRFS_I(inode)->root;
4691 struct fiemap_cache cache = { 0 };
4692 struct ulist *roots;
4693 struct ulist *tmp_ulist;
4702 path = btrfs_alloc_path();
4705 path->leave_spinning = 1;
4707 roots = ulist_alloc(GFP_KERNEL);
4708 tmp_ulist = ulist_alloc(GFP_KERNEL);
4709 if (!roots || !tmp_ulist) {
4711 goto out_free_ulist;
4714 start = round_down(start, btrfs_inode_sectorsize(inode));
4715 len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
4718 * lookup the last file extent. We're not using i_size here
4719 * because there might be preallocation past i_size
4721 ret = btrfs_lookup_file_extent(NULL, root, path,
4722 btrfs_ino(BTRFS_I(inode)), -1, 0);
4724 goto out_free_ulist;
4732 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4733 found_type = found_key.type;
4735 /* No extents, but there might be delalloc bits */
4736 if (found_key.objectid != btrfs_ino(BTRFS_I(inode)) ||
4737 found_type != BTRFS_EXTENT_DATA_KEY) {
4738 /* have to trust i_size as the end */
4740 last_for_get_extent = isize;
4743 * remember the start of the last extent. There are a
4744 * bunch of different factors that go into the length of the
4745 * extent, so its much less complex to remember where it started
4747 last = found_key.offset;
4748 last_for_get_extent = last + 1;
4750 btrfs_release_path(path);
4753 * we might have some extents allocated but more delalloc past those
4754 * extents. so, we trust isize unless the start of the last extent is
4759 last_for_get_extent = isize;
4762 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4765 em = get_extent_skip_holes(inode, start, last_for_get_extent);
4774 u64 offset_in_extent = 0;
4776 /* break if the extent we found is outside the range */
4777 if (em->start >= max || extent_map_end(em) < off)
4781 * get_extent may return an extent that starts before our
4782 * requested range. We have to make sure the ranges
4783 * we return to fiemap always move forward and don't
4784 * overlap, so adjust the offsets here
4786 em_start = max(em->start, off);
4789 * record the offset from the start of the extent
4790 * for adjusting the disk offset below. Only do this if the
4791 * extent isn't compressed since our in ram offset may be past
4792 * what we have actually allocated on disk.
4794 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4795 offset_in_extent = em_start - em->start;
4796 em_end = extent_map_end(em);
4797 em_len = em_end - em_start;
4799 if (em->block_start < EXTENT_MAP_LAST_BYTE)
4800 disko = em->block_start + offset_in_extent;
4805 * bump off for our next call to get_extent
4807 off = extent_map_end(em);
4811 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4813 flags |= FIEMAP_EXTENT_LAST;
4814 } else if (em->block_start == EXTENT_MAP_INLINE) {
4815 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4816 FIEMAP_EXTENT_NOT_ALIGNED);
4817 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4818 flags |= (FIEMAP_EXTENT_DELALLOC |
4819 FIEMAP_EXTENT_UNKNOWN);
4820 } else if (fieinfo->fi_extents_max) {
4821 u64 bytenr = em->block_start -
4822 (em->start - em->orig_start);
4825 * As btrfs supports shared space, this information
4826 * can be exported to userspace tools via
4827 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4828 * then we're just getting a count and we can skip the
4831 ret = btrfs_check_shared(root,
4832 btrfs_ino(BTRFS_I(inode)),
4833 bytenr, roots, tmp_ulist);
4837 flags |= FIEMAP_EXTENT_SHARED;
4840 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4841 flags |= FIEMAP_EXTENT_ENCODED;
4842 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4843 flags |= FIEMAP_EXTENT_UNWRITTEN;
4845 free_extent_map(em);
4847 if ((em_start >= last) || em_len == (u64)-1 ||
4848 (last == (u64)-1 && isize <= em_end)) {
4849 flags |= FIEMAP_EXTENT_LAST;
4853 /* now scan forward to see if this is really the last extent. */
4854 em = get_extent_skip_holes(inode, off, last_for_get_extent);
4860 flags |= FIEMAP_EXTENT_LAST;
4863 ret = emit_fiemap_extent(fieinfo, &cache, em_start, disko,
4873 ret = emit_last_fiemap_cache(fieinfo, &cache);
4874 free_extent_map(em);
4876 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4880 btrfs_free_path(path);
4882 ulist_free(tmp_ulist);
4886 static void __free_extent_buffer(struct extent_buffer *eb)
4888 kmem_cache_free(extent_buffer_cache, eb);
4891 int extent_buffer_under_io(const struct extent_buffer *eb)
4893 return (atomic_read(&eb->io_pages) ||
4894 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4895 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4899 * Release all pages attached to the extent buffer.
4901 static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb)
4905 int mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
4907 BUG_ON(extent_buffer_under_io(eb));
4909 num_pages = num_extent_pages(eb);
4910 for (i = 0; i < num_pages; i++) {
4911 struct page *page = eb->pages[i];
4916 spin_lock(&page->mapping->private_lock);
4918 * We do this since we'll remove the pages after we've
4919 * removed the eb from the radix tree, so we could race
4920 * and have this page now attached to the new eb. So
4921 * only clear page_private if it's still connected to
4924 if (PagePrivate(page) &&
4925 page->private == (unsigned long)eb) {
4926 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4927 BUG_ON(PageDirty(page));
4928 BUG_ON(PageWriteback(page));
4930 * We need to make sure we haven't be attached
4933 detach_page_private(page);
4937 spin_unlock(&page->mapping->private_lock);
4939 /* One for when we allocated the page */
4945 * Helper for releasing the extent buffer.
4947 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4949 btrfs_release_extent_buffer_pages(eb);
4950 btrfs_leak_debug_del(&eb->fs_info->eb_leak_lock, &eb->leak_list);
4951 __free_extent_buffer(eb);
4954 static struct extent_buffer *
4955 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4958 struct extent_buffer *eb = NULL;
4960 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4963 eb->fs_info = fs_info;
4965 rwlock_init(&eb->lock);
4966 atomic_set(&eb->blocking_readers, 0);
4967 eb->blocking_writers = 0;
4968 eb->lock_nested = false;
4969 init_waitqueue_head(&eb->write_lock_wq);
4970 init_waitqueue_head(&eb->read_lock_wq);
4972 btrfs_leak_debug_add(&fs_info->eb_leak_lock, &eb->leak_list,
4973 &fs_info->allocated_ebs);
4975 spin_lock_init(&eb->refs_lock);
4976 atomic_set(&eb->refs, 1);
4977 atomic_set(&eb->io_pages, 0);
4980 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4982 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4983 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4984 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4986 #ifdef CONFIG_BTRFS_DEBUG
4987 eb->spinning_writers = 0;
4988 atomic_set(&eb->spinning_readers, 0);
4989 atomic_set(&eb->read_locks, 0);
4990 eb->write_locks = 0;
4996 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src)
5000 struct extent_buffer *new;
5001 int num_pages = num_extent_pages(src);
5003 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
5007 for (i = 0; i < num_pages; i++) {
5008 p = alloc_page(GFP_NOFS);
5010 btrfs_release_extent_buffer(new);
5013 attach_extent_buffer_page(new, p);
5014 WARN_ON(PageDirty(p));
5017 copy_page(page_address(p), page_address(src->pages[i]));
5020 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
5021 set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags);
5026 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
5027 u64 start, unsigned long len)
5029 struct extent_buffer *eb;
5033 eb = __alloc_extent_buffer(fs_info, start, len);
5037 num_pages = num_extent_pages(eb);
5038 for (i = 0; i < num_pages; i++) {
5039 eb->pages[i] = alloc_page(GFP_NOFS);
5043 set_extent_buffer_uptodate(eb);
5044 btrfs_set_header_nritems(eb, 0);
5045 set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
5050 __free_page(eb->pages[i - 1]);
5051 __free_extent_buffer(eb);
5055 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
5058 return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
5061 static void check_buffer_tree_ref(struct extent_buffer *eb)
5065 * The TREE_REF bit is first set when the extent_buffer is added
5066 * to the radix tree. It is also reset, if unset, when a new reference
5067 * is created by find_extent_buffer.
5069 * It is only cleared in two cases: freeing the last non-tree
5070 * reference to the extent_buffer when its STALE bit is set or
5071 * calling releasepage when the tree reference is the only reference.
5073 * In both cases, care is taken to ensure that the extent_buffer's
5074 * pages are not under io. However, releasepage can be concurrently
5075 * called with creating new references, which is prone to race
5076 * conditions between the calls to check_buffer_tree_ref in those
5077 * codepaths and clearing TREE_REF in try_release_extent_buffer.
5079 * The actual lifetime of the extent_buffer in the radix tree is
5080 * adequately protected by the refcount, but the TREE_REF bit and
5081 * its corresponding reference are not. To protect against this
5082 * class of races, we call check_buffer_tree_ref from the codepaths
5083 * which trigger io after they set eb->io_pages. Note that once io is
5084 * initiated, TREE_REF can no longer be cleared, so that is the
5085 * moment at which any such race is best fixed.
5087 refs = atomic_read(&eb->refs);
5088 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5091 spin_lock(&eb->refs_lock);
5092 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5093 atomic_inc(&eb->refs);
5094 spin_unlock(&eb->refs_lock);
5097 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
5098 struct page *accessed)
5102 check_buffer_tree_ref(eb);
5104 num_pages = num_extent_pages(eb);
5105 for (i = 0; i < num_pages; i++) {
5106 struct page *p = eb->pages[i];
5109 mark_page_accessed(p);
5113 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
5116 struct extent_buffer *eb;
5119 eb = radix_tree_lookup(&fs_info->buffer_radix,
5120 start >> PAGE_SHIFT);
5121 if (eb && atomic_inc_not_zero(&eb->refs)) {
5124 * Lock our eb's refs_lock to avoid races with
5125 * free_extent_buffer. When we get our eb it might be flagged
5126 * with EXTENT_BUFFER_STALE and another task running
5127 * free_extent_buffer might have seen that flag set,
5128 * eb->refs == 2, that the buffer isn't under IO (dirty and
5129 * writeback flags not set) and it's still in the tree (flag
5130 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
5131 * of decrementing the extent buffer's reference count twice.
5132 * So here we could race and increment the eb's reference count,
5133 * clear its stale flag, mark it as dirty and drop our reference
5134 * before the other task finishes executing free_extent_buffer,
5135 * which would later result in an attempt to free an extent
5136 * buffer that is dirty.
5138 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
5139 spin_lock(&eb->refs_lock);
5140 spin_unlock(&eb->refs_lock);
5142 mark_extent_buffer_accessed(eb, NULL);
5150 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5151 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
5154 struct extent_buffer *eb, *exists = NULL;
5157 eb = find_extent_buffer(fs_info, start);
5160 eb = alloc_dummy_extent_buffer(fs_info, start);
5162 return ERR_PTR(-ENOMEM);
5163 eb->fs_info = fs_info;
5165 ret = radix_tree_preload(GFP_NOFS);
5167 exists = ERR_PTR(ret);
5170 spin_lock(&fs_info->buffer_lock);
5171 ret = radix_tree_insert(&fs_info->buffer_radix,
5172 start >> PAGE_SHIFT, eb);
5173 spin_unlock(&fs_info->buffer_lock);
5174 radix_tree_preload_end();
5175 if (ret == -EEXIST) {
5176 exists = find_extent_buffer(fs_info, start);
5182 check_buffer_tree_ref(eb);
5183 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5187 btrfs_release_extent_buffer(eb);
5192 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
5195 unsigned long len = fs_info->nodesize;
5198 unsigned long index = start >> PAGE_SHIFT;
5199 struct extent_buffer *eb;
5200 struct extent_buffer *exists = NULL;
5202 struct address_space *mapping = fs_info->btree_inode->i_mapping;
5206 if (!IS_ALIGNED(start, fs_info->sectorsize)) {
5207 btrfs_err(fs_info, "bad tree block start %llu", start);
5208 return ERR_PTR(-EINVAL);
5211 eb = find_extent_buffer(fs_info, start);
5215 eb = __alloc_extent_buffer(fs_info, start, len);
5217 return ERR_PTR(-ENOMEM);
5219 num_pages = num_extent_pages(eb);
5220 for (i = 0; i < num_pages; i++, index++) {
5221 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
5223 exists = ERR_PTR(-ENOMEM);
5227 spin_lock(&mapping->private_lock);
5228 if (PagePrivate(p)) {
5230 * We could have already allocated an eb for this page
5231 * and attached one so lets see if we can get a ref on
5232 * the existing eb, and if we can we know it's good and
5233 * we can just return that one, else we know we can just
5234 * overwrite page->private.
5236 exists = (struct extent_buffer *)p->private;
5237 if (atomic_inc_not_zero(&exists->refs)) {
5238 spin_unlock(&mapping->private_lock);
5241 mark_extent_buffer_accessed(exists, p);
5247 * Do this so attach doesn't complain and we need to
5248 * drop the ref the old guy had.
5250 ClearPagePrivate(p);
5251 WARN_ON(PageDirty(p));
5254 attach_extent_buffer_page(eb, p);
5255 spin_unlock(&mapping->private_lock);
5256 WARN_ON(PageDirty(p));
5258 if (!PageUptodate(p))
5262 * We can't unlock the pages just yet since the extent buffer
5263 * hasn't been properly inserted in the radix tree, this
5264 * opens a race with btree_releasepage which can free a page
5265 * while we are still filling in all pages for the buffer and
5270 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5272 ret = radix_tree_preload(GFP_NOFS);
5274 exists = ERR_PTR(ret);
5278 spin_lock(&fs_info->buffer_lock);
5279 ret = radix_tree_insert(&fs_info->buffer_radix,
5280 start >> PAGE_SHIFT, eb);
5281 spin_unlock(&fs_info->buffer_lock);
5282 radix_tree_preload_end();
5283 if (ret == -EEXIST) {
5284 exists = find_extent_buffer(fs_info, start);
5290 /* add one reference for the tree */
5291 check_buffer_tree_ref(eb);
5292 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5295 * Now it's safe to unlock the pages because any calls to
5296 * btree_releasepage will correctly detect that a page belongs to a
5297 * live buffer and won't free them prematurely.
5299 for (i = 0; i < num_pages; i++)
5300 unlock_page(eb->pages[i]);
5304 WARN_ON(!atomic_dec_and_test(&eb->refs));
5305 for (i = 0; i < num_pages; i++) {
5307 unlock_page(eb->pages[i]);
5310 btrfs_release_extent_buffer(eb);
5314 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5316 struct extent_buffer *eb =
5317 container_of(head, struct extent_buffer, rcu_head);
5319 __free_extent_buffer(eb);
5322 static int release_extent_buffer(struct extent_buffer *eb)
5323 __releases(&eb->refs_lock)
5325 lockdep_assert_held(&eb->refs_lock);
5327 WARN_ON(atomic_read(&eb->refs) == 0);
5328 if (atomic_dec_and_test(&eb->refs)) {
5329 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5330 struct btrfs_fs_info *fs_info = eb->fs_info;
5332 spin_unlock(&eb->refs_lock);
5334 spin_lock(&fs_info->buffer_lock);
5335 radix_tree_delete(&fs_info->buffer_radix,
5336 eb->start >> PAGE_SHIFT);
5337 spin_unlock(&fs_info->buffer_lock);
5339 spin_unlock(&eb->refs_lock);
5342 btrfs_leak_debug_del(&eb->fs_info->eb_leak_lock, &eb->leak_list);
5343 /* Should be safe to release our pages at this point */
5344 btrfs_release_extent_buffer_pages(eb);
5345 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5346 if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))) {
5347 __free_extent_buffer(eb);
5351 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5354 spin_unlock(&eb->refs_lock);
5359 void free_extent_buffer(struct extent_buffer *eb)
5367 refs = atomic_read(&eb->refs);
5368 if ((!test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) && refs <= 3)
5369 || (test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) &&
5372 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5377 spin_lock(&eb->refs_lock);
5378 if (atomic_read(&eb->refs) == 2 &&
5379 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5380 !extent_buffer_under_io(eb) &&
5381 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5382 atomic_dec(&eb->refs);
5385 * I know this is terrible, but it's temporary until we stop tracking
5386 * the uptodate bits and such for the extent buffers.
5388 release_extent_buffer(eb);
5391 void free_extent_buffer_stale(struct extent_buffer *eb)
5396 spin_lock(&eb->refs_lock);
5397 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5399 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5400 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5401 atomic_dec(&eb->refs);
5402 release_extent_buffer(eb);
5405 void clear_extent_buffer_dirty(const struct extent_buffer *eb)
5411 num_pages = num_extent_pages(eb);
5413 for (i = 0; i < num_pages; i++) {
5414 page = eb->pages[i];
5415 if (!PageDirty(page))
5419 WARN_ON(!PagePrivate(page));
5421 clear_page_dirty_for_io(page);
5422 xa_lock_irq(&page->mapping->i_pages);
5423 if (!PageDirty(page))
5424 __xa_clear_mark(&page->mapping->i_pages,
5425 page_index(page), PAGECACHE_TAG_DIRTY);
5426 xa_unlock_irq(&page->mapping->i_pages);
5427 ClearPageError(page);
5430 WARN_ON(atomic_read(&eb->refs) == 0);
5433 bool set_extent_buffer_dirty(struct extent_buffer *eb)
5439 check_buffer_tree_ref(eb);
5441 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5443 num_pages = num_extent_pages(eb);
5444 WARN_ON(atomic_read(&eb->refs) == 0);
5445 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5448 for (i = 0; i < num_pages; i++)
5449 set_page_dirty(eb->pages[i]);
5451 #ifdef CONFIG_BTRFS_DEBUG
5452 for (i = 0; i < num_pages; i++)
5453 ASSERT(PageDirty(eb->pages[i]));
5459 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5465 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5466 num_pages = num_extent_pages(eb);
5467 for (i = 0; i < num_pages; i++) {
5468 page = eb->pages[i];
5470 ClearPageUptodate(page);
5474 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5480 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5481 num_pages = num_extent_pages(eb);
5482 for (i = 0; i < num_pages; i++) {
5483 page = eb->pages[i];
5484 SetPageUptodate(page);
5488 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num)
5494 int locked_pages = 0;
5495 int all_uptodate = 1;
5497 unsigned long num_reads = 0;
5498 struct bio *bio = NULL;
5499 unsigned long bio_flags = 0;
5501 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5504 num_pages = num_extent_pages(eb);
5505 for (i = 0; i < num_pages; i++) {
5506 page = eb->pages[i];
5507 if (wait == WAIT_NONE) {
5508 if (!trylock_page(page))
5516 * We need to firstly lock all pages to make sure that
5517 * the uptodate bit of our pages won't be affected by
5518 * clear_extent_buffer_uptodate().
5520 for (i = 0; i < num_pages; i++) {
5521 page = eb->pages[i];
5522 if (!PageUptodate(page)) {
5529 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5533 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5534 eb->read_mirror = 0;
5535 atomic_set(&eb->io_pages, num_reads);
5537 * It is possible for releasepage to clear the TREE_REF bit before we
5538 * set io_pages. See check_buffer_tree_ref for a more detailed comment.
5540 check_buffer_tree_ref(eb);
5541 for (i = 0; i < num_pages; i++) {
5542 page = eb->pages[i];
5544 if (!PageUptodate(page)) {
5546 atomic_dec(&eb->io_pages);
5551 ClearPageError(page);
5552 err = __extent_read_full_page(page,
5553 btree_get_extent, &bio,
5554 mirror_num, &bio_flags,
5559 * We use &bio in above __extent_read_full_page,
5560 * so we ensure that if it returns error, the
5561 * current page fails to add itself to bio and
5562 * it's been unlocked.
5564 * We must dec io_pages by ourselves.
5566 atomic_dec(&eb->io_pages);
5574 err = submit_one_bio(bio, mirror_num, bio_flags);
5579 if (ret || wait != WAIT_COMPLETE)
5582 for (i = 0; i < num_pages; i++) {
5583 page = eb->pages[i];
5584 wait_on_page_locked(page);
5585 if (!PageUptodate(page))
5592 while (locked_pages > 0) {
5594 page = eb->pages[locked_pages];
5600 void read_extent_buffer(const struct extent_buffer *eb, void *dstv,
5601 unsigned long start, unsigned long len)
5607 char *dst = (char *)dstv;
5608 unsigned long i = start >> PAGE_SHIFT;
5610 if (start + len > eb->len) {
5611 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5612 eb->start, eb->len, start, len);
5613 memset(dst, 0, len);
5617 offset = offset_in_page(start);
5620 page = eb->pages[i];
5622 cur = min(len, (PAGE_SIZE - offset));
5623 kaddr = page_address(page);
5624 memcpy(dst, kaddr + offset, cur);
5633 int read_extent_buffer_to_user(const struct extent_buffer *eb,
5635 unsigned long start, unsigned long len)
5641 char __user *dst = (char __user *)dstv;
5642 unsigned long i = start >> PAGE_SHIFT;
5645 WARN_ON(start > eb->len);
5646 WARN_ON(start + len > eb->start + eb->len);
5648 offset = offset_in_page(start);
5651 page = eb->pages[i];
5653 cur = min(len, (PAGE_SIZE - offset));
5654 kaddr = page_address(page);
5655 if (copy_to_user(dst, kaddr + offset, cur)) {
5669 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
5670 unsigned long start, unsigned long len)
5676 char *ptr = (char *)ptrv;
5677 unsigned long i = start >> PAGE_SHIFT;
5680 WARN_ON(start > eb->len);
5681 WARN_ON(start + len > eb->start + eb->len);
5683 offset = offset_in_page(start);
5686 page = eb->pages[i];
5688 cur = min(len, (PAGE_SIZE - offset));
5690 kaddr = page_address(page);
5691 ret = memcmp(ptr, kaddr + offset, cur);
5703 void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
5708 WARN_ON(!PageUptodate(eb->pages[0]));
5709 kaddr = page_address(eb->pages[0]);
5710 memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
5714 void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *srcv)
5718 WARN_ON(!PageUptodate(eb->pages[0]));
5719 kaddr = page_address(eb->pages[0]);
5720 memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
5724 void write_extent_buffer(const struct extent_buffer *eb, const void *srcv,
5725 unsigned long start, unsigned long len)
5731 char *src = (char *)srcv;
5732 unsigned long i = start >> PAGE_SHIFT;
5734 WARN_ON(start > eb->len);
5735 WARN_ON(start + len > eb->start + eb->len);
5737 offset = offset_in_page(start);
5740 page = eb->pages[i];
5741 WARN_ON(!PageUptodate(page));
5743 cur = min(len, PAGE_SIZE - offset);
5744 kaddr = page_address(page);
5745 memcpy(kaddr + offset, src, cur);
5754 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
5761 unsigned long i = start >> PAGE_SHIFT;
5763 WARN_ON(start > eb->len);
5764 WARN_ON(start + len > eb->start + eb->len);
5766 offset = offset_in_page(start);
5769 page = eb->pages[i];
5770 WARN_ON(!PageUptodate(page));
5772 cur = min(len, PAGE_SIZE - offset);
5773 kaddr = page_address(page);
5774 memset(kaddr + offset, 0, cur);
5782 void copy_extent_buffer_full(const struct extent_buffer *dst,
5783 const struct extent_buffer *src)
5788 ASSERT(dst->len == src->len);
5790 num_pages = num_extent_pages(dst);
5791 for (i = 0; i < num_pages; i++)
5792 copy_page(page_address(dst->pages[i]),
5793 page_address(src->pages[i]));
5796 void copy_extent_buffer(const struct extent_buffer *dst,
5797 const struct extent_buffer *src,
5798 unsigned long dst_offset, unsigned long src_offset,
5801 u64 dst_len = dst->len;
5806 unsigned long i = dst_offset >> PAGE_SHIFT;
5808 WARN_ON(src->len != dst_len);
5810 offset = offset_in_page(dst_offset);
5813 page = dst->pages[i];
5814 WARN_ON(!PageUptodate(page));
5816 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5818 kaddr = page_address(page);
5819 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5829 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5831 * @eb: the extent buffer
5832 * @start: offset of the bitmap item in the extent buffer
5834 * @page_index: return index of the page in the extent buffer that contains the
5836 * @page_offset: return offset into the page given by page_index
5838 * This helper hides the ugliness of finding the byte in an extent buffer which
5839 * contains a given bit.
5841 static inline void eb_bitmap_offset(const struct extent_buffer *eb,
5842 unsigned long start, unsigned long nr,
5843 unsigned long *page_index,
5844 size_t *page_offset)
5846 size_t byte_offset = BIT_BYTE(nr);
5850 * The byte we want is the offset of the extent buffer + the offset of
5851 * the bitmap item in the extent buffer + the offset of the byte in the
5854 offset = start + byte_offset;
5856 *page_index = offset >> PAGE_SHIFT;
5857 *page_offset = offset_in_page(offset);
5861 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5862 * @eb: the extent buffer
5863 * @start: offset of the bitmap item in the extent buffer
5864 * @nr: bit number to test
5866 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
5874 eb_bitmap_offset(eb, start, nr, &i, &offset);
5875 page = eb->pages[i];
5876 WARN_ON(!PageUptodate(page));
5877 kaddr = page_address(page);
5878 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5882 * extent_buffer_bitmap_set - set an area of a bitmap
5883 * @eb: the extent buffer
5884 * @start: offset of the bitmap item in the extent buffer
5885 * @pos: bit number of the first bit
5886 * @len: number of bits to set
5888 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
5889 unsigned long pos, unsigned long len)
5895 const unsigned int size = pos + len;
5896 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5897 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5899 eb_bitmap_offset(eb, start, pos, &i, &offset);
5900 page = eb->pages[i];
5901 WARN_ON(!PageUptodate(page));
5902 kaddr = page_address(page);
5904 while (len >= bits_to_set) {
5905 kaddr[offset] |= mask_to_set;
5907 bits_to_set = BITS_PER_BYTE;
5909 if (++offset >= PAGE_SIZE && len > 0) {
5911 page = eb->pages[++i];
5912 WARN_ON(!PageUptodate(page));
5913 kaddr = page_address(page);
5917 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5918 kaddr[offset] |= mask_to_set;
5924 * extent_buffer_bitmap_clear - clear an area of a bitmap
5925 * @eb: the extent buffer
5926 * @start: offset of the bitmap item in the extent buffer
5927 * @pos: bit number of the first bit
5928 * @len: number of bits to clear
5930 void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
5931 unsigned long start, unsigned long pos,
5938 const unsigned int size = pos + len;
5939 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5940 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5942 eb_bitmap_offset(eb, start, pos, &i, &offset);
5943 page = eb->pages[i];
5944 WARN_ON(!PageUptodate(page));
5945 kaddr = page_address(page);
5947 while (len >= bits_to_clear) {
5948 kaddr[offset] &= ~mask_to_clear;
5949 len -= bits_to_clear;
5950 bits_to_clear = BITS_PER_BYTE;
5952 if (++offset >= PAGE_SIZE && len > 0) {
5954 page = eb->pages[++i];
5955 WARN_ON(!PageUptodate(page));
5956 kaddr = page_address(page);
5960 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5961 kaddr[offset] &= ~mask_to_clear;
5965 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5967 unsigned long distance = (src > dst) ? src - dst : dst - src;
5968 return distance < len;
5971 static void copy_pages(struct page *dst_page, struct page *src_page,
5972 unsigned long dst_off, unsigned long src_off,
5975 char *dst_kaddr = page_address(dst_page);
5977 int must_memmove = 0;
5979 if (dst_page != src_page) {
5980 src_kaddr = page_address(src_page);
5982 src_kaddr = dst_kaddr;
5983 if (areas_overlap(src_off, dst_off, len))
5988 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5990 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5993 void memcpy_extent_buffer(const struct extent_buffer *dst,
5994 unsigned long dst_offset, unsigned long src_offset,
5997 struct btrfs_fs_info *fs_info = dst->fs_info;
5999 size_t dst_off_in_page;
6000 size_t src_off_in_page;
6001 unsigned long dst_i;
6002 unsigned long src_i;
6004 if (src_offset + len > dst->len) {
6006 "memmove bogus src_offset %lu move len %lu dst len %lu",
6007 src_offset, len, dst->len);
6010 if (dst_offset + len > dst->len) {
6012 "memmove bogus dst_offset %lu move len %lu dst len %lu",
6013 dst_offset, len, dst->len);
6018 dst_off_in_page = offset_in_page(dst_offset);
6019 src_off_in_page = offset_in_page(src_offset);
6021 dst_i = dst_offset >> PAGE_SHIFT;
6022 src_i = src_offset >> PAGE_SHIFT;
6024 cur = min(len, (unsigned long)(PAGE_SIZE -
6026 cur = min_t(unsigned long, cur,
6027 (unsigned long)(PAGE_SIZE - dst_off_in_page));
6029 copy_pages(dst->pages[dst_i], dst->pages[src_i],
6030 dst_off_in_page, src_off_in_page, cur);
6038 void memmove_extent_buffer(const struct extent_buffer *dst,
6039 unsigned long dst_offset, unsigned long src_offset,
6042 struct btrfs_fs_info *fs_info = dst->fs_info;
6044 size_t dst_off_in_page;
6045 size_t src_off_in_page;
6046 unsigned long dst_end = dst_offset + len - 1;
6047 unsigned long src_end = src_offset + len - 1;
6048 unsigned long dst_i;
6049 unsigned long src_i;
6051 if (src_offset + len > dst->len) {
6053 "memmove bogus src_offset %lu move len %lu len %lu",
6054 src_offset, len, dst->len);
6057 if (dst_offset + len > dst->len) {
6059 "memmove bogus dst_offset %lu move len %lu len %lu",
6060 dst_offset, len, dst->len);
6063 if (dst_offset < src_offset) {
6064 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
6068 dst_i = dst_end >> PAGE_SHIFT;
6069 src_i = src_end >> PAGE_SHIFT;
6071 dst_off_in_page = offset_in_page(dst_end);
6072 src_off_in_page = offset_in_page(src_end);
6074 cur = min_t(unsigned long, len, src_off_in_page + 1);
6075 cur = min(cur, dst_off_in_page + 1);
6076 copy_pages(dst->pages[dst_i], dst->pages[src_i],
6077 dst_off_in_page - cur + 1,
6078 src_off_in_page - cur + 1, cur);
6086 int try_release_extent_buffer(struct page *page)
6088 struct extent_buffer *eb;
6091 * We need to make sure nobody is attaching this page to an eb right
6094 spin_lock(&page->mapping->private_lock);
6095 if (!PagePrivate(page)) {
6096 spin_unlock(&page->mapping->private_lock);
6100 eb = (struct extent_buffer *)page->private;
6104 * This is a little awful but should be ok, we need to make sure that
6105 * the eb doesn't disappear out from under us while we're looking at
6108 spin_lock(&eb->refs_lock);
6109 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
6110 spin_unlock(&eb->refs_lock);
6111 spin_unlock(&page->mapping->private_lock);
6114 spin_unlock(&page->mapping->private_lock);
6117 * If tree ref isn't set then we know the ref on this eb is a real ref,
6118 * so just return, this page will likely be freed soon anyway.
6120 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
6121 spin_unlock(&eb->refs_lock);
6125 return release_extent_buffer(eb);