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(buffers);
39 static LIST_HEAD(states);
41 static DEFINE_SPINLOCK(leak_lock);
44 void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
48 spin_lock_irqsave(&leak_lock, flags);
50 spin_unlock_irqrestore(&leak_lock, flags);
54 void btrfs_leak_debug_del(struct list_head *entry)
58 spin_lock_irqsave(&leak_lock, flags);
60 spin_unlock_irqrestore(&leak_lock, flags);
63 static inline void btrfs_extent_buffer_leak_debug_check(void)
65 struct extent_buffer *eb;
67 while (!list_empty(&buffers)) {
68 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
69 pr_err("BTRFS: buffer leak start %llu len %lu refs %d bflags %lu\n",
70 eb->start, eb->len, atomic_read(&eb->refs), eb->bflags);
71 list_del(&eb->leak_list);
72 kmem_cache_free(extent_buffer_cache, eb);
76 static inline void btrfs_extent_state_leak_debug_check(void)
78 struct extent_state *state;
80 while (!list_empty(&states)) {
81 state = list_entry(states.next, struct extent_state, leak_list);
82 pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
83 state->start, state->end, state->state,
84 extent_state_in_tree(state),
85 refcount_read(&state->refs));
86 list_del(&state->leak_list);
87 kmem_cache_free(extent_state_cache, state);
91 #define btrfs_debug_check_extent_io_range(tree, start, end) \
92 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
93 static inline void __btrfs_debug_check_extent_io_range(const char *caller,
94 struct extent_io_tree *tree, u64 start, u64 end)
96 struct inode *inode = tree->private_data;
99 if (!inode || !is_data_inode(inode))
102 isize = i_size_read(inode);
103 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
104 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
105 "%s: ino %llu isize %llu odd range [%llu,%llu]",
106 caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
110 #define btrfs_leak_debug_add(new, head) do {} while (0)
111 #define btrfs_leak_debug_del(entry) do {} while (0)
112 #define btrfs_extent_buffer_leak_debug_check() do {} while (0)
113 #define btrfs_extent_state_leak_debug_check() do {} while (0)
114 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
120 struct rb_node rb_node;
123 struct extent_page_data {
125 struct extent_io_tree *tree;
126 /* tells writepage not to lock the state bits for this range
127 * it still does the unlocking
129 unsigned int extent_locked:1;
131 /* tells the submit_bio code to use REQ_SYNC */
132 unsigned int sync_io:1;
135 static int add_extent_changeset(struct extent_state *state, unsigned bits,
136 struct extent_changeset *changeset,
143 if (set && (state->state & bits) == bits)
145 if (!set && (state->state & bits) == 0)
147 changeset->bytes_changed += state->end - state->start + 1;
148 ret = ulist_add(&changeset->range_changed, state->start, state->end,
153 static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
154 unsigned long bio_flags)
156 blk_status_t ret = 0;
157 struct extent_io_tree *tree = bio->bi_private;
159 bio->bi_private = NULL;
162 ret = tree->ops->submit_bio_hook(tree->private_data, bio,
163 mirror_num, bio_flags);
165 btrfsic_submit_bio(bio);
167 return blk_status_to_errno(ret);
170 /* Cleanup unsubmitted bios */
171 static void end_write_bio(struct extent_page_data *epd, int ret)
174 epd->bio->bi_status = errno_to_blk_status(ret);
181 * Submit bio from extent page data via submit_one_bio
183 * Return 0 if everything is OK.
184 * Return <0 for error.
186 static int __must_check flush_write_bio(struct extent_page_data *epd)
191 ret = submit_one_bio(epd->bio, 0, 0);
193 * Clean up of epd->bio is handled by its endio function.
194 * And endio is either triggered by successful bio execution
195 * or the error handler of submit bio hook.
196 * So at this point, no matter what happened, we don't need
197 * to clean up epd->bio.
204 int __init extent_state_cache_init(void)
206 extent_state_cache = kmem_cache_create("btrfs_extent_state",
207 sizeof(struct extent_state), 0,
208 SLAB_MEM_SPREAD, NULL);
209 if (!extent_state_cache)
214 int __init extent_io_init(void)
216 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
217 sizeof(struct extent_buffer), 0,
218 SLAB_MEM_SPREAD, NULL);
219 if (!extent_buffer_cache)
222 if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE,
223 offsetof(struct btrfs_io_bio, bio),
225 goto free_buffer_cache;
227 if (bioset_integrity_create(&btrfs_bioset, BIO_POOL_SIZE))
233 bioset_exit(&btrfs_bioset);
236 kmem_cache_destroy(extent_buffer_cache);
237 extent_buffer_cache = NULL;
241 void __cold extent_state_cache_exit(void)
243 btrfs_extent_state_leak_debug_check();
244 kmem_cache_destroy(extent_state_cache);
247 void __cold extent_io_exit(void)
249 btrfs_extent_buffer_leak_debug_check();
252 * Make sure all delayed rcu free are flushed before we
256 kmem_cache_destroy(extent_buffer_cache);
257 bioset_exit(&btrfs_bioset);
260 void extent_io_tree_init(struct btrfs_fs_info *fs_info,
261 struct extent_io_tree *tree, unsigned int owner,
264 tree->fs_info = fs_info;
265 tree->state = RB_ROOT;
267 tree->dirty_bytes = 0;
268 spin_lock_init(&tree->lock);
269 tree->private_data = private_data;
273 void extent_io_tree_release(struct extent_io_tree *tree)
275 spin_lock(&tree->lock);
277 * Do a single barrier for the waitqueue_active check here, the state
278 * of the waitqueue should not change once extent_io_tree_release is
282 while (!RB_EMPTY_ROOT(&tree->state)) {
283 struct rb_node *node;
284 struct extent_state *state;
286 node = rb_first(&tree->state);
287 state = rb_entry(node, struct extent_state, rb_node);
288 rb_erase(&state->rb_node, &tree->state);
289 RB_CLEAR_NODE(&state->rb_node);
291 * btree io trees aren't supposed to have tasks waiting for
292 * changes in the flags of extent states ever.
294 ASSERT(!waitqueue_active(&state->wq));
295 free_extent_state(state);
297 cond_resched_lock(&tree->lock);
299 spin_unlock(&tree->lock);
302 static struct extent_state *alloc_extent_state(gfp_t mask)
304 struct extent_state *state;
307 * The given mask might be not appropriate for the slab allocator,
308 * drop the unsupported bits
310 mask &= ~(__GFP_DMA32|__GFP_HIGHMEM);
311 state = kmem_cache_alloc(extent_state_cache, mask);
315 state->failrec = NULL;
316 RB_CLEAR_NODE(&state->rb_node);
317 btrfs_leak_debug_add(&state->leak_list, &states);
318 refcount_set(&state->refs, 1);
319 init_waitqueue_head(&state->wq);
320 trace_alloc_extent_state(state, mask, _RET_IP_);
324 void free_extent_state(struct extent_state *state)
328 if (refcount_dec_and_test(&state->refs)) {
329 WARN_ON(extent_state_in_tree(state));
330 btrfs_leak_debug_del(&state->leak_list);
331 trace_free_extent_state(state, _RET_IP_);
332 kmem_cache_free(extent_state_cache, state);
336 static struct rb_node *tree_insert(struct rb_root *root,
337 struct rb_node *search_start,
339 struct rb_node *node,
340 struct rb_node ***p_in,
341 struct rb_node **parent_in)
344 struct rb_node *parent = NULL;
345 struct tree_entry *entry;
347 if (p_in && parent_in) {
353 p = search_start ? &search_start : &root->rb_node;
356 entry = rb_entry(parent, struct tree_entry, rb_node);
358 if (offset < entry->start)
360 else if (offset > entry->end)
367 rb_link_node(node, parent, p);
368 rb_insert_color(node, root);
373 * __etree_search - searche @tree for an entry that contains @offset. Such
374 * entry would have entry->start <= offset && entry->end >= offset.
376 * @tree - the tree to search
377 * @offset - offset that should fall within an entry in @tree
378 * @next_ret - pointer to the first entry whose range ends after @offset
379 * @prev - pointer to the first entry whose range begins before @offset
380 * @p_ret - pointer where new node should be anchored (used when inserting an
382 * @parent_ret - points to entry which would have been the parent of the entry,
385 * This function returns a pointer to the entry that contains @offset byte
386 * address. If no such entry exists, then NULL is returned and the other
387 * pointer arguments to the function are filled, otherwise the found entry is
388 * returned and other pointers are left untouched.
390 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
391 struct rb_node **next_ret,
392 struct rb_node **prev_ret,
393 struct rb_node ***p_ret,
394 struct rb_node **parent_ret)
396 struct rb_root *root = &tree->state;
397 struct rb_node **n = &root->rb_node;
398 struct rb_node *prev = NULL;
399 struct rb_node *orig_prev = NULL;
400 struct tree_entry *entry;
401 struct tree_entry *prev_entry = NULL;
405 entry = rb_entry(prev, struct tree_entry, rb_node);
408 if (offset < entry->start)
410 else if (offset > entry->end)
423 while (prev && offset > prev_entry->end) {
424 prev = rb_next(prev);
425 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
432 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
433 while (prev && offset < prev_entry->start) {
434 prev = rb_prev(prev);
435 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
442 static inline struct rb_node *
443 tree_search_for_insert(struct extent_io_tree *tree,
445 struct rb_node ***p_ret,
446 struct rb_node **parent_ret)
448 struct rb_node *next= NULL;
451 ret = __etree_search(tree, offset, &next, NULL, p_ret, parent_ret);
457 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
460 return tree_search_for_insert(tree, offset, NULL, NULL);
464 * utility function to look for merge candidates inside a given range.
465 * Any extents with matching state are merged together into a single
466 * extent in the tree. Extents with EXTENT_IO in their state field
467 * are not merged because the end_io handlers need to be able to do
468 * operations on them without sleeping (or doing allocations/splits).
470 * This should be called with the tree lock held.
472 static void merge_state(struct extent_io_tree *tree,
473 struct extent_state *state)
475 struct extent_state *other;
476 struct rb_node *other_node;
478 if (state->state & (EXTENT_LOCKED | EXTENT_BOUNDARY))
481 other_node = rb_prev(&state->rb_node);
483 other = rb_entry(other_node, struct extent_state, rb_node);
484 if (other->end == state->start - 1 &&
485 other->state == state->state) {
486 if (tree->private_data &&
487 is_data_inode(tree->private_data))
488 btrfs_merge_delalloc_extent(tree->private_data,
490 state->start = other->start;
491 rb_erase(&other->rb_node, &tree->state);
492 RB_CLEAR_NODE(&other->rb_node);
493 free_extent_state(other);
496 other_node = rb_next(&state->rb_node);
498 other = rb_entry(other_node, struct extent_state, rb_node);
499 if (other->start == state->end + 1 &&
500 other->state == state->state) {
501 if (tree->private_data &&
502 is_data_inode(tree->private_data))
503 btrfs_merge_delalloc_extent(tree->private_data,
505 state->end = other->end;
506 rb_erase(&other->rb_node, &tree->state);
507 RB_CLEAR_NODE(&other->rb_node);
508 free_extent_state(other);
513 static void set_state_bits(struct extent_io_tree *tree,
514 struct extent_state *state, unsigned *bits,
515 struct extent_changeset *changeset);
518 * insert an extent_state struct into the tree. 'bits' are set on the
519 * struct before it is inserted.
521 * This may return -EEXIST if the extent is already there, in which case the
522 * state struct is freed.
524 * The tree lock is not taken internally. This is a utility function and
525 * probably isn't what you want to call (see set/clear_extent_bit).
527 static int insert_state(struct extent_io_tree *tree,
528 struct extent_state *state, u64 start, u64 end,
530 struct rb_node **parent,
531 unsigned *bits, struct extent_changeset *changeset)
533 struct rb_node *node;
536 btrfs_err(tree->fs_info,
537 "insert state: end < start %llu %llu", end, start);
540 state->start = start;
543 set_state_bits(tree, state, bits, changeset);
545 node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
547 struct extent_state *found;
548 found = rb_entry(node, struct extent_state, rb_node);
549 btrfs_err(tree->fs_info,
550 "found node %llu %llu on insert of %llu %llu",
551 found->start, found->end, start, end);
554 merge_state(tree, state);
559 * split a given extent state struct in two, inserting the preallocated
560 * struct 'prealloc' as the newly created second half. 'split' indicates an
561 * offset inside 'orig' where it should be split.
564 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
565 * are two extent state structs in the tree:
566 * prealloc: [orig->start, split - 1]
567 * orig: [ split, orig->end ]
569 * The tree locks are not taken by this function. They need to be held
572 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
573 struct extent_state *prealloc, u64 split)
575 struct rb_node *node;
577 if (tree->private_data && is_data_inode(tree->private_data))
578 btrfs_split_delalloc_extent(tree->private_data, orig, split);
580 prealloc->start = orig->start;
581 prealloc->end = split - 1;
582 prealloc->state = orig->state;
585 node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
586 &prealloc->rb_node, NULL, NULL);
588 free_extent_state(prealloc);
594 static struct extent_state *next_state(struct extent_state *state)
596 struct rb_node *next = rb_next(&state->rb_node);
598 return rb_entry(next, struct extent_state, rb_node);
604 * utility function to clear some bits in an extent state struct.
605 * it will optionally wake up anyone waiting on this state (wake == 1).
607 * If no bits are set on the state struct after clearing things, the
608 * struct is freed and removed from the tree
610 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
611 struct extent_state *state,
612 unsigned *bits, int wake,
613 struct extent_changeset *changeset)
615 struct extent_state *next;
616 unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
619 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
620 u64 range = state->end - state->start + 1;
621 WARN_ON(range > tree->dirty_bytes);
622 tree->dirty_bytes -= range;
625 if (tree->private_data && is_data_inode(tree->private_data))
626 btrfs_clear_delalloc_extent(tree->private_data, state, bits);
628 ret = add_extent_changeset(state, bits_to_clear, changeset, 0);
630 state->state &= ~bits_to_clear;
633 if (state->state == 0) {
634 next = next_state(state);
635 if (extent_state_in_tree(state)) {
636 rb_erase(&state->rb_node, &tree->state);
637 RB_CLEAR_NODE(&state->rb_node);
638 free_extent_state(state);
643 merge_state(tree, state);
644 next = next_state(state);
649 static struct extent_state *
650 alloc_extent_state_atomic(struct extent_state *prealloc)
653 prealloc = alloc_extent_state(GFP_ATOMIC);
658 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
660 struct inode *inode = tree->private_data;
662 btrfs_panic(btrfs_sb(inode->i_sb), err,
663 "locking error: extent tree was modified by another thread while locked");
667 * clear some bits on a range in the tree. This may require splitting
668 * or inserting elements in the tree, so the gfp mask is used to
669 * indicate which allocations or sleeping are allowed.
671 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
672 * the given range from the tree regardless of state (ie for truncate).
674 * the range [start, end] is inclusive.
676 * This takes the tree lock, and returns 0 on success and < 0 on error.
678 int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
679 unsigned bits, int wake, int delete,
680 struct extent_state **cached_state,
681 gfp_t mask, struct extent_changeset *changeset)
683 struct extent_state *state;
684 struct extent_state *cached;
685 struct extent_state *prealloc = NULL;
686 struct rb_node *node;
691 btrfs_debug_check_extent_io_range(tree, start, end);
692 trace_btrfs_clear_extent_bit(tree, start, end - start + 1, bits);
694 if (bits & EXTENT_DELALLOC)
695 bits |= EXTENT_NORESERVE;
698 bits |= ~EXTENT_CTLBITS;
700 if (bits & (EXTENT_LOCKED | EXTENT_BOUNDARY))
703 if (!prealloc && gfpflags_allow_blocking(mask)) {
705 * Don't care for allocation failure here because we might end
706 * up not needing the pre-allocated extent state at all, which
707 * is the case if we only have in the tree extent states that
708 * cover our input range and don't cover too any other range.
709 * If we end up needing a new extent state we allocate it later.
711 prealloc = alloc_extent_state(mask);
714 spin_lock(&tree->lock);
716 cached = *cached_state;
719 *cached_state = NULL;
723 if (cached && extent_state_in_tree(cached) &&
724 cached->start <= start && cached->end > start) {
726 refcount_dec(&cached->refs);
731 free_extent_state(cached);
734 * this search will find the extents that end after
737 node = tree_search(tree, start);
740 state = rb_entry(node, struct extent_state, rb_node);
742 if (state->start > end)
744 WARN_ON(state->end < start);
745 last_end = state->end;
747 /* the state doesn't have the wanted bits, go ahead */
748 if (!(state->state & bits)) {
749 state = next_state(state);
754 * | ---- desired range ---- |
756 * | ------------- state -------------- |
758 * We need to split the extent we found, and may flip
759 * bits on second half.
761 * If the extent we found extends past our range, we
762 * just split and search again. It'll get split again
763 * the next time though.
765 * If the extent we found is inside our range, we clear
766 * the desired bit on it.
769 if (state->start < start) {
770 prealloc = alloc_extent_state_atomic(prealloc);
772 err = split_state(tree, state, prealloc, start);
774 extent_io_tree_panic(tree, err);
779 if (state->end <= end) {
780 state = clear_state_bit(tree, state, &bits, wake,
787 * | ---- desired range ---- |
789 * We need to split the extent, and clear the bit
792 if (state->start <= end && state->end > end) {
793 prealloc = alloc_extent_state_atomic(prealloc);
795 err = split_state(tree, state, prealloc, end + 1);
797 extent_io_tree_panic(tree, err);
802 clear_state_bit(tree, prealloc, &bits, wake, changeset);
808 state = clear_state_bit(tree, state, &bits, wake, changeset);
810 if (last_end == (u64)-1)
812 start = last_end + 1;
813 if (start <= end && state && !need_resched())
819 spin_unlock(&tree->lock);
820 if (gfpflags_allow_blocking(mask))
825 spin_unlock(&tree->lock);
827 free_extent_state(prealloc);
833 static void wait_on_state(struct extent_io_tree *tree,
834 struct extent_state *state)
835 __releases(tree->lock)
836 __acquires(tree->lock)
839 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
840 spin_unlock(&tree->lock);
842 spin_lock(&tree->lock);
843 finish_wait(&state->wq, &wait);
847 * waits for one or more bits to clear on a range in the state tree.
848 * The range [start, end] is inclusive.
849 * The tree lock is taken by this function
851 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
854 struct extent_state *state;
855 struct rb_node *node;
857 btrfs_debug_check_extent_io_range(tree, start, end);
859 spin_lock(&tree->lock);
863 * this search will find all the extents that end after
866 node = tree_search(tree, start);
871 state = rb_entry(node, struct extent_state, rb_node);
873 if (state->start > end)
876 if (state->state & bits) {
877 start = state->start;
878 refcount_inc(&state->refs);
879 wait_on_state(tree, state);
880 free_extent_state(state);
883 start = state->end + 1;
888 if (!cond_resched_lock(&tree->lock)) {
889 node = rb_next(node);
894 spin_unlock(&tree->lock);
897 static void set_state_bits(struct extent_io_tree *tree,
898 struct extent_state *state,
899 unsigned *bits, struct extent_changeset *changeset)
901 unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
904 if (tree->private_data && is_data_inode(tree->private_data))
905 btrfs_set_delalloc_extent(tree->private_data, state, bits);
907 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
908 u64 range = state->end - state->start + 1;
909 tree->dirty_bytes += range;
911 ret = add_extent_changeset(state, bits_to_set, changeset, 1);
913 state->state |= bits_to_set;
916 static void cache_state_if_flags(struct extent_state *state,
917 struct extent_state **cached_ptr,
920 if (cached_ptr && !(*cached_ptr)) {
921 if (!flags || (state->state & flags)) {
923 refcount_inc(&state->refs);
928 static void cache_state(struct extent_state *state,
929 struct extent_state **cached_ptr)
931 return cache_state_if_flags(state, cached_ptr,
932 EXTENT_LOCKED | EXTENT_BOUNDARY);
936 * set some bits on a range in the tree. This may require allocations or
937 * sleeping, so the gfp mask is used to indicate what is allowed.
939 * If any of the exclusive bits are set, this will fail with -EEXIST if some
940 * part of the range already has the desired bits set. The start of the
941 * existing range is returned in failed_start in this case.
943 * [start, end] is inclusive This takes the tree lock.
946 static int __must_check
947 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
948 unsigned bits, unsigned exclusive_bits,
949 u64 *failed_start, struct extent_state **cached_state,
950 gfp_t mask, struct extent_changeset *changeset)
952 struct extent_state *state;
953 struct extent_state *prealloc = NULL;
954 struct rb_node *node;
956 struct rb_node *parent;
961 btrfs_debug_check_extent_io_range(tree, start, end);
962 trace_btrfs_set_extent_bit(tree, start, end - start + 1, bits);
965 if (!prealloc && gfpflags_allow_blocking(mask)) {
967 * Don't care for allocation failure here because we might end
968 * up not needing the pre-allocated extent state at all, which
969 * is the case if we only have in the tree extent states that
970 * cover our input range and don't cover too any other range.
971 * If we end up needing a new extent state we allocate it later.
973 prealloc = alloc_extent_state(mask);
976 spin_lock(&tree->lock);
977 if (cached_state && *cached_state) {
978 state = *cached_state;
979 if (state->start <= start && state->end > start &&
980 extent_state_in_tree(state)) {
981 node = &state->rb_node;
986 * this search will find all the extents that end after
989 node = tree_search_for_insert(tree, start, &p, &parent);
991 prealloc = alloc_extent_state_atomic(prealloc);
993 err = insert_state(tree, prealloc, start, end,
994 &p, &parent, &bits, changeset);
996 extent_io_tree_panic(tree, err);
998 cache_state(prealloc, cached_state);
1002 state = rb_entry(node, struct extent_state, rb_node);
1004 last_start = state->start;
1005 last_end = state->end;
1008 * | ---- desired range ---- |
1011 * Just lock what we found and keep going
1013 if (state->start == start && state->end <= end) {
1014 if (state->state & exclusive_bits) {
1015 *failed_start = state->start;
1020 set_state_bits(tree, state, &bits, changeset);
1021 cache_state(state, cached_state);
1022 merge_state(tree, state);
1023 if (last_end == (u64)-1)
1025 start = last_end + 1;
1026 state = next_state(state);
1027 if (start < end && state && state->start == start &&
1034 * | ---- desired range ---- |
1037 * | ------------- state -------------- |
1039 * We need to split the extent we found, and may flip bits on
1042 * If the extent we found extends past our
1043 * range, we just split and search again. It'll get split
1044 * again the next time though.
1046 * If the extent we found is inside our range, we set the
1047 * desired bit on it.
1049 if (state->start < start) {
1050 if (state->state & exclusive_bits) {
1051 *failed_start = start;
1056 prealloc = alloc_extent_state_atomic(prealloc);
1058 err = split_state(tree, state, prealloc, start);
1060 extent_io_tree_panic(tree, err);
1065 if (state->end <= end) {
1066 set_state_bits(tree, state, &bits, changeset);
1067 cache_state(state, cached_state);
1068 merge_state(tree, state);
1069 if (last_end == (u64)-1)
1071 start = last_end + 1;
1072 state = next_state(state);
1073 if (start < end && state && state->start == start &&
1080 * | ---- desired range ---- |
1081 * | state | or | state |
1083 * There's a hole, we need to insert something in it and
1084 * ignore the extent we found.
1086 if (state->start > start) {
1088 if (end < last_start)
1091 this_end = last_start - 1;
1093 prealloc = alloc_extent_state_atomic(prealloc);
1097 * Avoid to free 'prealloc' if it can be merged with
1100 err = insert_state(tree, prealloc, start, this_end,
1101 NULL, NULL, &bits, changeset);
1103 extent_io_tree_panic(tree, err);
1105 cache_state(prealloc, cached_state);
1107 start = this_end + 1;
1111 * | ---- desired range ---- |
1113 * We need to split the extent, and set the bit
1116 if (state->start <= end && state->end > end) {
1117 if (state->state & exclusive_bits) {
1118 *failed_start = start;
1123 prealloc = alloc_extent_state_atomic(prealloc);
1125 err = split_state(tree, state, prealloc, end + 1);
1127 extent_io_tree_panic(tree, err);
1129 set_state_bits(tree, prealloc, &bits, changeset);
1130 cache_state(prealloc, cached_state);
1131 merge_state(tree, prealloc);
1139 spin_unlock(&tree->lock);
1140 if (gfpflags_allow_blocking(mask))
1145 spin_unlock(&tree->lock);
1147 free_extent_state(prealloc);
1153 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1154 unsigned bits, u64 * failed_start,
1155 struct extent_state **cached_state, gfp_t mask)
1157 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
1158 cached_state, mask, NULL);
1163 * convert_extent_bit - convert all bits in a given range from one bit to
1165 * @tree: the io tree to search
1166 * @start: the start offset in bytes
1167 * @end: the end offset in bytes (inclusive)
1168 * @bits: the bits to set in this range
1169 * @clear_bits: the bits to clear in this range
1170 * @cached_state: state that we're going to cache
1172 * This will go through and set bits for the given range. If any states exist
1173 * already in this range they are set with the given bit and cleared of the
1174 * clear_bits. This is only meant to be used by things that are mergeable, ie
1175 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1176 * boundary bits like LOCK.
1178 * All allocations are done with GFP_NOFS.
1180 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1181 unsigned bits, unsigned clear_bits,
1182 struct extent_state **cached_state)
1184 struct extent_state *state;
1185 struct extent_state *prealloc = NULL;
1186 struct rb_node *node;
1188 struct rb_node *parent;
1192 bool first_iteration = true;
1194 btrfs_debug_check_extent_io_range(tree, start, end);
1195 trace_btrfs_convert_extent_bit(tree, start, end - start + 1, bits,
1201 * Best effort, don't worry if extent state allocation fails
1202 * here for the first iteration. We might have a cached state
1203 * that matches exactly the target range, in which case no
1204 * extent state allocations are needed. We'll only know this
1205 * after locking the tree.
1207 prealloc = alloc_extent_state(GFP_NOFS);
1208 if (!prealloc && !first_iteration)
1212 spin_lock(&tree->lock);
1213 if (cached_state && *cached_state) {
1214 state = *cached_state;
1215 if (state->start <= start && state->end > start &&
1216 extent_state_in_tree(state)) {
1217 node = &state->rb_node;
1223 * this search will find all the extents that end after
1226 node = tree_search_for_insert(tree, start, &p, &parent);
1228 prealloc = alloc_extent_state_atomic(prealloc);
1233 err = insert_state(tree, prealloc, start, end,
1234 &p, &parent, &bits, NULL);
1236 extent_io_tree_panic(tree, err);
1237 cache_state(prealloc, cached_state);
1241 state = rb_entry(node, struct extent_state, rb_node);
1243 last_start = state->start;
1244 last_end = state->end;
1247 * | ---- desired range ---- |
1250 * Just lock what we found and keep going
1252 if (state->start == start && state->end <= end) {
1253 set_state_bits(tree, state, &bits, NULL);
1254 cache_state(state, cached_state);
1255 state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
1256 if (last_end == (u64)-1)
1258 start = last_end + 1;
1259 if (start < end && state && state->start == start &&
1266 * | ---- desired range ---- |
1269 * | ------------- state -------------- |
1271 * We need to split the extent we found, and may flip bits on
1274 * If the extent we found extends past our
1275 * range, we just split and search again. It'll get split
1276 * again the next time though.
1278 * If the extent we found is inside our range, we set the
1279 * desired bit on it.
1281 if (state->start < start) {
1282 prealloc = alloc_extent_state_atomic(prealloc);
1287 err = split_state(tree, state, prealloc, start);
1289 extent_io_tree_panic(tree, err);
1293 if (state->end <= end) {
1294 set_state_bits(tree, state, &bits, NULL);
1295 cache_state(state, cached_state);
1296 state = clear_state_bit(tree, state, &clear_bits, 0,
1298 if (last_end == (u64)-1)
1300 start = last_end + 1;
1301 if (start < end && state && state->start == start &&
1308 * | ---- desired range ---- |
1309 * | state | or | state |
1311 * There's a hole, we need to insert something in it and
1312 * ignore the extent we found.
1314 if (state->start > start) {
1316 if (end < last_start)
1319 this_end = last_start - 1;
1321 prealloc = alloc_extent_state_atomic(prealloc);
1328 * Avoid to free 'prealloc' if it can be merged with
1331 err = insert_state(tree, prealloc, start, this_end,
1332 NULL, NULL, &bits, NULL);
1334 extent_io_tree_panic(tree, err);
1335 cache_state(prealloc, cached_state);
1337 start = this_end + 1;
1341 * | ---- desired range ---- |
1343 * We need to split the extent, and set the bit
1346 if (state->start <= end && state->end > end) {
1347 prealloc = alloc_extent_state_atomic(prealloc);
1353 err = split_state(tree, state, prealloc, end + 1);
1355 extent_io_tree_panic(tree, err);
1357 set_state_bits(tree, prealloc, &bits, NULL);
1358 cache_state(prealloc, cached_state);
1359 clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
1367 spin_unlock(&tree->lock);
1369 first_iteration = false;
1373 spin_unlock(&tree->lock);
1375 free_extent_state(prealloc);
1380 /* wrappers around set/clear extent bit */
1381 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1382 unsigned bits, struct extent_changeset *changeset)
1385 * We don't support EXTENT_LOCKED yet, as current changeset will
1386 * record any bits changed, so for EXTENT_LOCKED case, it will
1387 * either fail with -EEXIST or changeset will record the whole
1390 BUG_ON(bits & EXTENT_LOCKED);
1392 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
1396 int set_extent_bits_nowait(struct extent_io_tree *tree, u64 start, u64 end,
1399 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL,
1403 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1404 unsigned bits, int wake, int delete,
1405 struct extent_state **cached)
1407 return __clear_extent_bit(tree, start, end, bits, wake, delete,
1408 cached, GFP_NOFS, NULL);
1411 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1412 unsigned bits, struct extent_changeset *changeset)
1415 * Don't support EXTENT_LOCKED case, same reason as
1416 * set_record_extent_bits().
1418 BUG_ON(bits & EXTENT_LOCKED);
1420 return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
1425 * either insert or lock state struct between start and end use mask to tell
1426 * us if waiting is desired.
1428 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1429 struct extent_state **cached_state)
1435 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
1436 EXTENT_LOCKED, &failed_start,
1437 cached_state, GFP_NOFS, NULL);
1438 if (err == -EEXIST) {
1439 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1440 start = failed_start;
1443 WARN_ON(start > end);
1448 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1453 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1454 &failed_start, NULL, GFP_NOFS, NULL);
1455 if (err == -EEXIST) {
1456 if (failed_start > start)
1457 clear_extent_bit(tree, start, failed_start - 1,
1458 EXTENT_LOCKED, 1, 0, NULL);
1464 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1466 unsigned long index = start >> PAGE_SHIFT;
1467 unsigned long end_index = end >> PAGE_SHIFT;
1470 while (index <= end_index) {
1471 page = find_get_page(inode->i_mapping, index);
1472 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1473 clear_page_dirty_for_io(page);
1479 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1481 unsigned long index = start >> PAGE_SHIFT;
1482 unsigned long end_index = end >> PAGE_SHIFT;
1485 while (index <= end_index) {
1486 page = find_get_page(inode->i_mapping, index);
1487 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1488 __set_page_dirty_nobuffers(page);
1489 account_page_redirty(page);
1495 /* find the first state struct with 'bits' set after 'start', and
1496 * return it. tree->lock must be held. NULL will returned if
1497 * nothing was found after 'start'
1499 static struct extent_state *
1500 find_first_extent_bit_state(struct extent_io_tree *tree,
1501 u64 start, unsigned bits)
1503 struct rb_node *node;
1504 struct extent_state *state;
1507 * this search will find all the extents that end after
1510 node = tree_search(tree, start);
1515 state = rb_entry(node, struct extent_state, rb_node);
1516 if (state->end >= start && (state->state & bits))
1519 node = rb_next(node);
1528 * find the first offset in the io tree with 'bits' set. zero is
1529 * returned if we find something, and *start_ret and *end_ret are
1530 * set to reflect the state struct that was found.
1532 * If nothing was found, 1 is returned. If found something, return 0.
1534 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1535 u64 *start_ret, u64 *end_ret, unsigned bits,
1536 struct extent_state **cached_state)
1538 struct extent_state *state;
1541 spin_lock(&tree->lock);
1542 if (cached_state && *cached_state) {
1543 state = *cached_state;
1544 if (state->end == start - 1 && extent_state_in_tree(state)) {
1545 while ((state = next_state(state)) != NULL) {
1546 if (state->state & bits)
1549 free_extent_state(*cached_state);
1550 *cached_state = NULL;
1553 free_extent_state(*cached_state);
1554 *cached_state = NULL;
1557 state = find_first_extent_bit_state(tree, start, bits);
1560 cache_state_if_flags(state, cached_state, 0);
1561 *start_ret = state->start;
1562 *end_ret = state->end;
1566 spin_unlock(&tree->lock);
1571 * find_first_clear_extent_bit - find the first range that has @bits not set.
1572 * This range could start before @start.
1574 * @tree - the tree to search
1575 * @start - the offset at/after which the found extent should start
1576 * @start_ret - records the beginning of the range
1577 * @end_ret - records the end of the range (inclusive)
1578 * @bits - the set of bits which must be unset
1580 * Since unallocated range is also considered one which doesn't have the bits
1581 * set it's possible that @end_ret contains -1, this happens in case the range
1582 * spans (last_range_end, end of device]. In this case it's up to the caller to
1583 * trim @end_ret to the appropriate size.
1585 void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start,
1586 u64 *start_ret, u64 *end_ret, unsigned bits)
1588 struct extent_state *state;
1589 struct rb_node *node, *prev = NULL, *next;
1591 spin_lock(&tree->lock);
1593 /* Find first extent with bits cleared */
1595 node = __etree_search(tree, start, &next, &prev, NULL, NULL);
1596 if (!node && !next && !prev) {
1598 * Tree is completely empty, send full range and let
1599 * caller deal with it
1604 } else if (!node && !next) {
1606 * We are past the last allocated chunk, set start at
1607 * the end of the last extent.
1609 state = rb_entry(prev, struct extent_state, rb_node);
1610 *start_ret = state->end + 1;
1617 * At this point 'node' either contains 'start' or start is
1620 state = rb_entry(node, struct extent_state, rb_node);
1622 if (in_range(start, state->start, state->end - state->start + 1)) {
1623 if (state->state & bits) {
1625 * |--range with bits sets--|
1629 start = state->end + 1;
1632 * 'start' falls within a range that doesn't
1633 * have the bits set, so take its start as
1634 * the beginning of the desired range
1636 * |--range with bits cleared----|
1640 *start_ret = state->start;
1645 * |---prev range---|---hole/unset---|---node range---|
1651 * |---hole/unset--||--first node--|
1656 state = rb_entry(prev, struct extent_state,
1658 *start_ret = state->end + 1;
1667 * Find the longest stretch from start until an entry which has the
1671 state = rb_entry(node, struct extent_state, rb_node);
1672 if (state->end >= start && !(state->state & bits)) {
1673 *end_ret = state->end;
1675 *end_ret = state->start - 1;
1679 node = rb_next(node);
1684 spin_unlock(&tree->lock);
1688 * find a contiguous range of bytes in the file marked as delalloc, not
1689 * more than 'max_bytes'. start and end are used to return the range,
1691 * true is returned if we find something, false if nothing was in the tree
1693 bool btrfs_find_delalloc_range(struct extent_io_tree *tree, u64 *start,
1694 u64 *end, u64 max_bytes,
1695 struct extent_state **cached_state)
1697 struct rb_node *node;
1698 struct extent_state *state;
1699 u64 cur_start = *start;
1701 u64 total_bytes = 0;
1703 spin_lock(&tree->lock);
1706 * this search will find all the extents that end after
1709 node = tree_search(tree, cur_start);
1716 state = rb_entry(node, struct extent_state, rb_node);
1717 if (found && (state->start != cur_start ||
1718 (state->state & EXTENT_BOUNDARY))) {
1721 if (!(state->state & EXTENT_DELALLOC)) {
1727 *start = state->start;
1728 *cached_state = state;
1729 refcount_inc(&state->refs);
1733 cur_start = state->end + 1;
1734 node = rb_next(node);
1735 total_bytes += state->end - state->start + 1;
1736 if (total_bytes >= max_bytes)
1742 spin_unlock(&tree->lock);
1746 static int __process_pages_contig(struct address_space *mapping,
1747 struct page *locked_page,
1748 pgoff_t start_index, pgoff_t end_index,
1749 unsigned long page_ops, pgoff_t *index_ret);
1751 static noinline void __unlock_for_delalloc(struct inode *inode,
1752 struct page *locked_page,
1755 unsigned long index = start >> PAGE_SHIFT;
1756 unsigned long end_index = end >> PAGE_SHIFT;
1758 ASSERT(locked_page);
1759 if (index == locked_page->index && end_index == index)
1762 __process_pages_contig(inode->i_mapping, locked_page, index, end_index,
1766 static noinline int lock_delalloc_pages(struct inode *inode,
1767 struct page *locked_page,
1771 unsigned long index = delalloc_start >> PAGE_SHIFT;
1772 unsigned long index_ret = index;
1773 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1776 ASSERT(locked_page);
1777 if (index == locked_page->index && index == end_index)
1780 ret = __process_pages_contig(inode->i_mapping, locked_page, index,
1781 end_index, PAGE_LOCK, &index_ret);
1783 __unlock_for_delalloc(inode, locked_page, delalloc_start,
1784 (u64)index_ret << PAGE_SHIFT);
1789 * Find and lock a contiguous range of bytes in the file marked as delalloc, no
1790 * more than @max_bytes. @Start and @end are used to return the range,
1792 * Return: true if we find something
1793 * false if nothing was in the tree
1796 noinline_for_stack bool find_lock_delalloc_range(struct inode *inode,
1797 struct page *locked_page, u64 *start,
1800 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
1801 u64 max_bytes = BTRFS_MAX_EXTENT_SIZE;
1805 struct extent_state *cached_state = NULL;
1810 /* step one, find a bunch of delalloc bytes starting at start */
1811 delalloc_start = *start;
1813 found = btrfs_find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1814 max_bytes, &cached_state);
1815 if (!found || delalloc_end <= *start) {
1816 *start = delalloc_start;
1817 *end = delalloc_end;
1818 free_extent_state(cached_state);
1823 * start comes from the offset of locked_page. We have to lock
1824 * pages in order, so we can't process delalloc bytes before
1827 if (delalloc_start < *start)
1828 delalloc_start = *start;
1831 * make sure to limit the number of pages we try to lock down
1833 if (delalloc_end + 1 - delalloc_start > max_bytes)
1834 delalloc_end = delalloc_start + max_bytes - 1;
1836 /* step two, lock all the pages after the page that has start */
1837 ret = lock_delalloc_pages(inode, locked_page,
1838 delalloc_start, delalloc_end);
1839 ASSERT(!ret || ret == -EAGAIN);
1840 if (ret == -EAGAIN) {
1841 /* some of the pages are gone, lets avoid looping by
1842 * shortening the size of the delalloc range we're searching
1844 free_extent_state(cached_state);
1845 cached_state = NULL;
1847 max_bytes = PAGE_SIZE;
1856 /* step three, lock the state bits for the whole range */
1857 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1859 /* then test to make sure it is all still delalloc */
1860 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1861 EXTENT_DELALLOC, 1, cached_state);
1863 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1865 __unlock_for_delalloc(inode, locked_page,
1866 delalloc_start, delalloc_end);
1870 free_extent_state(cached_state);
1871 *start = delalloc_start;
1872 *end = delalloc_end;
1877 static int __process_pages_contig(struct address_space *mapping,
1878 struct page *locked_page,
1879 pgoff_t start_index, pgoff_t end_index,
1880 unsigned long page_ops, pgoff_t *index_ret)
1882 unsigned long nr_pages = end_index - start_index + 1;
1883 unsigned long pages_locked = 0;
1884 pgoff_t index = start_index;
1885 struct page *pages[16];
1890 if (page_ops & PAGE_LOCK) {
1891 ASSERT(page_ops == PAGE_LOCK);
1892 ASSERT(index_ret && *index_ret == start_index);
1895 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1896 mapping_set_error(mapping, -EIO);
1898 while (nr_pages > 0) {
1899 ret = find_get_pages_contig(mapping, index,
1900 min_t(unsigned long,
1901 nr_pages, ARRAY_SIZE(pages)), pages);
1904 * Only if we're going to lock these pages,
1905 * can we find nothing at @index.
1907 ASSERT(page_ops & PAGE_LOCK);
1912 for (i = 0; i < ret; i++) {
1913 if (page_ops & PAGE_SET_PRIVATE2)
1914 SetPagePrivate2(pages[i]);
1916 if (locked_page && pages[i] == locked_page) {
1921 if (page_ops & PAGE_CLEAR_DIRTY)
1922 clear_page_dirty_for_io(pages[i]);
1923 if (page_ops & PAGE_SET_WRITEBACK)
1924 set_page_writeback(pages[i]);
1925 if (page_ops & PAGE_SET_ERROR)
1926 SetPageError(pages[i]);
1927 if (page_ops & PAGE_END_WRITEBACK)
1928 end_page_writeback(pages[i]);
1929 if (page_ops & PAGE_UNLOCK)
1930 unlock_page(pages[i]);
1931 if (page_ops & PAGE_LOCK) {
1932 lock_page(pages[i]);
1933 if (!PageDirty(pages[i]) ||
1934 pages[i]->mapping != mapping) {
1935 unlock_page(pages[i]);
1949 if (err && index_ret)
1950 *index_ret = start_index + pages_locked - 1;
1954 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1955 struct page *locked_page,
1956 unsigned clear_bits,
1957 unsigned long page_ops)
1959 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0,
1962 __process_pages_contig(inode->i_mapping, locked_page,
1963 start >> PAGE_SHIFT, end >> PAGE_SHIFT,
1968 * count the number of bytes in the tree that have a given bit(s)
1969 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1970 * cached. The total number found is returned.
1972 u64 count_range_bits(struct extent_io_tree *tree,
1973 u64 *start, u64 search_end, u64 max_bytes,
1974 unsigned bits, int contig)
1976 struct rb_node *node;
1977 struct extent_state *state;
1978 u64 cur_start = *start;
1979 u64 total_bytes = 0;
1983 if (WARN_ON(search_end <= cur_start))
1986 spin_lock(&tree->lock);
1987 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1988 total_bytes = tree->dirty_bytes;
1992 * this search will find all the extents that end after
1995 node = tree_search(tree, cur_start);
2000 state = rb_entry(node, struct extent_state, rb_node);
2001 if (state->start > search_end)
2003 if (contig && found && state->start > last + 1)
2005 if (state->end >= cur_start && (state->state & bits) == bits) {
2006 total_bytes += min(search_end, state->end) + 1 -
2007 max(cur_start, state->start);
2008 if (total_bytes >= max_bytes)
2011 *start = max(cur_start, state->start);
2015 } else if (contig && found) {
2018 node = rb_next(node);
2023 spin_unlock(&tree->lock);
2028 * set the private field for a given byte offset in the tree. If there isn't
2029 * an extent_state there already, this does nothing.
2031 int set_state_failrec(struct extent_io_tree *tree, u64 start,
2032 struct io_failure_record *failrec)
2034 struct rb_node *node;
2035 struct extent_state *state;
2038 spin_lock(&tree->lock);
2040 * this search will find all the extents that end after
2043 node = tree_search(tree, start);
2048 state = rb_entry(node, struct extent_state, rb_node);
2049 if (state->start != start) {
2053 state->failrec = failrec;
2055 spin_unlock(&tree->lock);
2059 int get_state_failrec(struct extent_io_tree *tree, u64 start,
2060 struct io_failure_record **failrec)
2062 struct rb_node *node;
2063 struct extent_state *state;
2066 spin_lock(&tree->lock);
2068 * this search will find all the extents that end after
2071 node = tree_search(tree, start);
2076 state = rb_entry(node, struct extent_state, rb_node);
2077 if (state->start != start) {
2081 *failrec = state->failrec;
2083 spin_unlock(&tree->lock);
2088 * searches a range in the state tree for a given mask.
2089 * If 'filled' == 1, this returns 1 only if every extent in the tree
2090 * has the bits set. Otherwise, 1 is returned if any bit in the
2091 * range is found set.
2093 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
2094 unsigned bits, int filled, struct extent_state *cached)
2096 struct extent_state *state = NULL;
2097 struct rb_node *node;
2100 spin_lock(&tree->lock);
2101 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
2102 cached->end > start)
2103 node = &cached->rb_node;
2105 node = tree_search(tree, start);
2106 while (node && start <= end) {
2107 state = rb_entry(node, struct extent_state, rb_node);
2109 if (filled && state->start > start) {
2114 if (state->start > end)
2117 if (state->state & bits) {
2121 } else if (filled) {
2126 if (state->end == (u64)-1)
2129 start = state->end + 1;
2132 node = rb_next(node);
2139 spin_unlock(&tree->lock);
2144 * helper function to set a given page up to date if all the
2145 * extents in the tree for that page are up to date
2147 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
2149 u64 start = page_offset(page);
2150 u64 end = start + PAGE_SIZE - 1;
2151 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
2152 SetPageUptodate(page);
2155 int free_io_failure(struct extent_io_tree *failure_tree,
2156 struct extent_io_tree *io_tree,
2157 struct io_failure_record *rec)
2162 set_state_failrec(failure_tree, rec->start, NULL);
2163 ret = clear_extent_bits(failure_tree, rec->start,
2164 rec->start + rec->len - 1,
2165 EXTENT_LOCKED | EXTENT_DIRTY);
2169 ret = clear_extent_bits(io_tree, rec->start,
2170 rec->start + rec->len - 1,
2180 * this bypasses the standard btrfs submit functions deliberately, as
2181 * the standard behavior is to write all copies in a raid setup. here we only
2182 * want to write the one bad copy. so we do the mapping for ourselves and issue
2183 * submit_bio directly.
2184 * to avoid any synchronization issues, wait for the data after writing, which
2185 * actually prevents the read that triggered the error from finishing.
2186 * currently, there can be no more than two copies of every data bit. thus,
2187 * exactly one rewrite is required.
2189 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
2190 u64 length, u64 logical, struct page *page,
2191 unsigned int pg_offset, int mirror_num)
2194 struct btrfs_device *dev;
2197 struct btrfs_bio *bbio = NULL;
2200 ASSERT(!(fs_info->sb->s_flags & SB_RDONLY));
2201 BUG_ON(!mirror_num);
2203 bio = btrfs_io_bio_alloc(1);
2204 bio->bi_iter.bi_size = 0;
2205 map_length = length;
2208 * Avoid races with device replace and make sure our bbio has devices
2209 * associated to its stripes that don't go away while we are doing the
2210 * read repair operation.
2212 btrfs_bio_counter_inc_blocked(fs_info);
2213 if (btrfs_is_parity_mirror(fs_info, logical, length)) {
2215 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
2216 * to update all raid stripes, but here we just want to correct
2217 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
2218 * stripe's dev and sector.
2220 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical,
2221 &map_length, &bbio, 0);
2223 btrfs_bio_counter_dec(fs_info);
2227 ASSERT(bbio->mirror_num == 1);
2229 ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
2230 &map_length, &bbio, mirror_num);
2232 btrfs_bio_counter_dec(fs_info);
2236 BUG_ON(mirror_num != bbio->mirror_num);
2239 sector = bbio->stripes[bbio->mirror_num - 1].physical >> 9;
2240 bio->bi_iter.bi_sector = sector;
2241 dev = bbio->stripes[bbio->mirror_num - 1].dev;
2242 btrfs_put_bbio(bbio);
2243 if (!dev || !dev->bdev ||
2244 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
2245 btrfs_bio_counter_dec(fs_info);
2249 bio_set_dev(bio, dev->bdev);
2250 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
2251 bio_add_page(bio, page, length, pg_offset);
2253 if (btrfsic_submit_bio_wait(bio)) {
2254 /* try to remap that extent elsewhere? */
2255 btrfs_bio_counter_dec(fs_info);
2257 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2261 btrfs_info_rl_in_rcu(fs_info,
2262 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2264 rcu_str_deref(dev->name), sector);
2265 btrfs_bio_counter_dec(fs_info);
2270 int btrfs_repair_eb_io_failure(struct extent_buffer *eb, int mirror_num)
2272 struct btrfs_fs_info *fs_info = eb->fs_info;
2273 u64 start = eb->start;
2274 int i, num_pages = num_extent_pages(eb);
2277 if (sb_rdonly(fs_info->sb))
2280 for (i = 0; i < num_pages; i++) {
2281 struct page *p = eb->pages[i];
2283 ret = repair_io_failure(fs_info, 0, start, PAGE_SIZE, start, p,
2284 start - page_offset(p), mirror_num);
2294 * each time an IO finishes, we do a fast check in the IO failure tree
2295 * to see if we need to process or clean up an io_failure_record
2297 int clean_io_failure(struct btrfs_fs_info *fs_info,
2298 struct extent_io_tree *failure_tree,
2299 struct extent_io_tree *io_tree, u64 start,
2300 struct page *page, u64 ino, unsigned int pg_offset)
2303 struct io_failure_record *failrec;
2304 struct extent_state *state;
2309 ret = count_range_bits(failure_tree, &private, (u64)-1, 1,
2314 ret = get_state_failrec(failure_tree, start, &failrec);
2318 BUG_ON(!failrec->this_mirror);
2320 if (failrec->in_validation) {
2321 /* there was no real error, just free the record */
2322 btrfs_debug(fs_info,
2323 "clean_io_failure: freeing dummy error at %llu",
2327 if (sb_rdonly(fs_info->sb))
2330 spin_lock(&io_tree->lock);
2331 state = find_first_extent_bit_state(io_tree,
2334 spin_unlock(&io_tree->lock);
2336 if (state && state->start <= failrec->start &&
2337 state->end >= failrec->start + failrec->len - 1) {
2338 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2340 if (num_copies > 1) {
2341 repair_io_failure(fs_info, ino, start, failrec->len,
2342 failrec->logical, page, pg_offset,
2343 failrec->failed_mirror);
2348 free_io_failure(failure_tree, io_tree, failrec);
2354 * Can be called when
2355 * - hold extent lock
2356 * - under ordered extent
2357 * - the inode is freeing
2359 void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end)
2361 struct extent_io_tree *failure_tree = &inode->io_failure_tree;
2362 struct io_failure_record *failrec;
2363 struct extent_state *state, *next;
2365 if (RB_EMPTY_ROOT(&failure_tree->state))
2368 spin_lock(&failure_tree->lock);
2369 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2371 if (state->start > end)
2374 ASSERT(state->end <= end);
2376 next = next_state(state);
2378 failrec = state->failrec;
2379 free_extent_state(state);
2384 spin_unlock(&failure_tree->lock);
2387 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2388 struct io_failure_record **failrec_ret)
2390 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2391 struct io_failure_record *failrec;
2392 struct extent_map *em;
2393 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2394 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2395 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2399 ret = get_state_failrec(failure_tree, start, &failrec);
2401 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2405 failrec->start = start;
2406 failrec->len = end - start + 1;
2407 failrec->this_mirror = 0;
2408 failrec->bio_flags = 0;
2409 failrec->in_validation = 0;
2411 read_lock(&em_tree->lock);
2412 em = lookup_extent_mapping(em_tree, start, failrec->len);
2414 read_unlock(&em_tree->lock);
2419 if (em->start > start || em->start + em->len <= start) {
2420 free_extent_map(em);
2423 read_unlock(&em_tree->lock);
2429 logical = start - em->start;
2430 logical = em->block_start + logical;
2431 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2432 logical = em->block_start;
2433 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2434 extent_set_compress_type(&failrec->bio_flags,
2438 btrfs_debug(fs_info,
2439 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2440 logical, start, failrec->len);
2442 failrec->logical = logical;
2443 free_extent_map(em);
2445 /* set the bits in the private failure tree */
2446 ret = set_extent_bits(failure_tree, start, end,
2447 EXTENT_LOCKED | EXTENT_DIRTY);
2449 ret = set_state_failrec(failure_tree, start, failrec);
2450 /* set the bits in the inode's tree */
2452 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2458 btrfs_debug(fs_info,
2459 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2460 failrec->logical, failrec->start, failrec->len,
2461 failrec->in_validation);
2463 * when data can be on disk more than twice, add to failrec here
2464 * (e.g. with a list for failed_mirror) to make
2465 * clean_io_failure() clean all those errors at once.
2469 *failrec_ret = failrec;
2474 bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages,
2475 struct io_failure_record *failrec, int failed_mirror)
2477 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2480 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
2481 if (num_copies == 1) {
2483 * we only have a single copy of the data, so don't bother with
2484 * all the retry and error correction code that follows. no
2485 * matter what the error is, it is very likely to persist.
2487 btrfs_debug(fs_info,
2488 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2489 num_copies, failrec->this_mirror, failed_mirror);
2494 * there are two premises:
2495 * a) deliver good data to the caller
2496 * b) correct the bad sectors on disk
2498 if (failed_bio_pages > 1) {
2500 * to fulfill b), we need to know the exact failing sectors, as
2501 * we don't want to rewrite any more than the failed ones. thus,
2502 * we need separate read requests for the failed bio
2504 * if the following BUG_ON triggers, our validation request got
2505 * merged. we need separate requests for our algorithm to work.
2507 BUG_ON(failrec->in_validation);
2508 failrec->in_validation = 1;
2509 failrec->this_mirror = failed_mirror;
2512 * we're ready to fulfill a) and b) alongside. get a good copy
2513 * of the failed sector and if we succeed, we have setup
2514 * everything for repair_io_failure to do the rest for us.
2516 if (failrec->in_validation) {
2517 BUG_ON(failrec->this_mirror != failed_mirror);
2518 failrec->in_validation = 0;
2519 failrec->this_mirror = 0;
2521 failrec->failed_mirror = failed_mirror;
2522 failrec->this_mirror++;
2523 if (failrec->this_mirror == failed_mirror)
2524 failrec->this_mirror++;
2527 if (failrec->this_mirror > num_copies) {
2528 btrfs_debug(fs_info,
2529 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2530 num_copies, failrec->this_mirror, failed_mirror);
2538 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
2539 struct io_failure_record *failrec,
2540 struct page *page, int pg_offset, int icsum,
2541 bio_end_io_t *endio_func, void *data)
2543 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2545 struct btrfs_io_bio *btrfs_failed_bio;
2546 struct btrfs_io_bio *btrfs_bio;
2548 bio = btrfs_io_bio_alloc(1);
2549 bio->bi_end_io = endio_func;
2550 bio->bi_iter.bi_sector = failrec->logical >> 9;
2551 bio->bi_iter.bi_size = 0;
2552 bio->bi_private = data;
2554 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2555 if (btrfs_failed_bio->csum) {
2556 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2558 btrfs_bio = btrfs_io_bio(bio);
2559 btrfs_bio->csum = btrfs_bio->csum_inline;
2561 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
2565 bio_add_page(bio, page, failrec->len, pg_offset);
2571 * This is a generic handler for readpage errors. If other copies exist, read
2572 * those and write back good data to the failed position. Does not investigate
2573 * in remapping the failed extent elsewhere, hoping the device will be smart
2574 * enough to do this as needed
2576 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2577 struct page *page, u64 start, u64 end,
2580 struct io_failure_record *failrec;
2581 struct inode *inode = page->mapping->host;
2582 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2583 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2586 blk_status_t status;
2588 unsigned failed_bio_pages = failed_bio->bi_iter.bi_size >> PAGE_SHIFT;
2590 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2592 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2596 if (!btrfs_check_repairable(inode, failed_bio_pages, failrec,
2598 free_io_failure(failure_tree, tree, failrec);
2602 if (failed_bio_pages > 1)
2603 read_mode |= REQ_FAILFAST_DEV;
2605 phy_offset >>= inode->i_sb->s_blocksize_bits;
2606 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
2607 start - page_offset(page),
2608 (int)phy_offset, failed_bio->bi_end_io,
2610 bio->bi_opf = REQ_OP_READ | read_mode;
2612 btrfs_debug(btrfs_sb(inode->i_sb),
2613 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2614 read_mode, failrec->this_mirror, failrec->in_validation);
2616 status = tree->ops->submit_bio_hook(tree->private_data, bio, failrec->this_mirror,
2617 failrec->bio_flags);
2619 free_io_failure(failure_tree, tree, failrec);
2621 ret = blk_status_to_errno(status);
2627 /* lots and lots of room for performance fixes in the end_bio funcs */
2629 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2631 int uptodate = (err == 0);
2634 btrfs_writepage_endio_finish_ordered(page, start, end, uptodate);
2637 ClearPageUptodate(page);
2639 ret = err < 0 ? err : -EIO;
2640 mapping_set_error(page->mapping, ret);
2645 * after a writepage IO is done, we need to:
2646 * clear the uptodate bits on error
2647 * clear the writeback bits in the extent tree for this IO
2648 * end_page_writeback if the page has no more pending IO
2650 * Scheduling is not allowed, so the extent state tree is expected
2651 * to have one and only one object corresponding to this IO.
2653 static void end_bio_extent_writepage(struct bio *bio)
2655 int error = blk_status_to_errno(bio->bi_status);
2656 struct bio_vec *bvec;
2659 struct bvec_iter_all iter_all;
2661 ASSERT(!bio_flagged(bio, BIO_CLONED));
2662 bio_for_each_segment_all(bvec, bio, iter_all) {
2663 struct page *page = bvec->bv_page;
2664 struct inode *inode = page->mapping->host;
2665 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2667 /* We always issue full-page reads, but if some block
2668 * in a page fails to read, blk_update_request() will
2669 * advance bv_offset and adjust bv_len to compensate.
2670 * Print a warning for nonzero offsets, and an error
2671 * if they don't add up to a full page. */
2672 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2673 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2675 "partial page write in btrfs with offset %u and length %u",
2676 bvec->bv_offset, bvec->bv_len);
2679 "incomplete page write in btrfs with offset %u and length %u",
2680 bvec->bv_offset, bvec->bv_len);
2683 start = page_offset(page);
2684 end = start + bvec->bv_offset + bvec->bv_len - 1;
2686 end_extent_writepage(page, error, start, end);
2687 end_page_writeback(page);
2694 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2697 struct extent_state *cached = NULL;
2698 u64 end = start + len - 1;
2700 if (uptodate && tree->track_uptodate)
2701 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2702 unlock_extent_cached_atomic(tree, start, end, &cached);
2706 * after a readpage IO is done, we need to:
2707 * clear the uptodate bits on error
2708 * set the uptodate bits if things worked
2709 * set the page up to date if all extents in the tree are uptodate
2710 * clear the lock bit in the extent tree
2711 * unlock the page if there are no other extents locked for it
2713 * Scheduling is not allowed, so the extent state tree is expected
2714 * to have one and only one object corresponding to this IO.
2716 static void end_bio_extent_readpage(struct bio *bio)
2718 struct bio_vec *bvec;
2719 int uptodate = !bio->bi_status;
2720 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2721 struct extent_io_tree *tree, *failure_tree;
2726 u64 extent_start = 0;
2730 struct bvec_iter_all iter_all;
2732 ASSERT(!bio_flagged(bio, BIO_CLONED));
2733 bio_for_each_segment_all(bvec, bio, iter_all) {
2734 struct page *page = bvec->bv_page;
2735 struct inode *inode = page->mapping->host;
2736 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2737 bool data_inode = btrfs_ino(BTRFS_I(inode))
2738 != BTRFS_BTREE_INODE_OBJECTID;
2740 btrfs_debug(fs_info,
2741 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2742 (u64)bio->bi_iter.bi_sector, bio->bi_status,
2743 io_bio->mirror_num);
2744 tree = &BTRFS_I(inode)->io_tree;
2745 failure_tree = &BTRFS_I(inode)->io_failure_tree;
2747 /* We always issue full-page reads, but if some block
2748 * in a page fails to read, blk_update_request() will
2749 * advance bv_offset and adjust bv_len to compensate.
2750 * Print a warning for nonzero offsets, and an error
2751 * if they don't add up to a full page. */
2752 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2753 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2755 "partial page read in btrfs with offset %u and length %u",
2756 bvec->bv_offset, bvec->bv_len);
2759 "incomplete page read in btrfs with offset %u and length %u",
2760 bvec->bv_offset, bvec->bv_len);
2763 start = page_offset(page);
2764 end = start + bvec->bv_offset + bvec->bv_len - 1;
2767 mirror = io_bio->mirror_num;
2768 if (likely(uptodate)) {
2769 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2775 clean_io_failure(BTRFS_I(inode)->root->fs_info,
2776 failure_tree, tree, start,
2778 btrfs_ino(BTRFS_I(inode)), 0);
2781 if (likely(uptodate))
2787 * The generic bio_readpage_error handles errors the
2788 * following way: If possible, new read requests are
2789 * created and submitted and will end up in
2790 * end_bio_extent_readpage as well (if we're lucky,
2791 * not in the !uptodate case). In that case it returns
2792 * 0 and we just go on with the next page in our bio.
2793 * If it can't handle the error it will return -EIO and
2794 * we remain responsible for that page.
2796 ret = bio_readpage_error(bio, offset, page, start, end,
2799 uptodate = !bio->bi_status;
2804 struct extent_buffer *eb;
2806 eb = (struct extent_buffer *)page->private;
2807 set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
2808 eb->read_mirror = mirror;
2809 atomic_dec(&eb->io_pages);
2810 if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD,
2812 btree_readahead_hook(eb, -EIO);
2815 if (likely(uptodate)) {
2816 loff_t i_size = i_size_read(inode);
2817 pgoff_t end_index = i_size >> PAGE_SHIFT;
2820 /* Zero out the end if this page straddles i_size */
2821 off = offset_in_page(i_size);
2822 if (page->index == end_index && off)
2823 zero_user_segment(page, off, PAGE_SIZE);
2824 SetPageUptodate(page);
2826 ClearPageUptodate(page);
2832 if (unlikely(!uptodate)) {
2834 endio_readpage_release_extent(tree,
2840 endio_readpage_release_extent(tree, start,
2841 end - start + 1, 0);
2842 } else if (!extent_len) {
2843 extent_start = start;
2844 extent_len = end + 1 - start;
2845 } else if (extent_start + extent_len == start) {
2846 extent_len += end + 1 - start;
2848 endio_readpage_release_extent(tree, extent_start,
2849 extent_len, uptodate);
2850 extent_start = start;
2851 extent_len = end + 1 - start;
2856 endio_readpage_release_extent(tree, extent_start, extent_len,
2858 btrfs_io_bio_free_csum(io_bio);
2863 * Initialize the members up to but not including 'bio'. Use after allocating a
2864 * new bio by bio_alloc_bioset as it does not initialize the bytes outside of
2865 * 'bio' because use of __GFP_ZERO is not supported.
2867 static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio)
2869 memset(btrfs_bio, 0, offsetof(struct btrfs_io_bio, bio));
2873 * The following helpers allocate a bio. As it's backed by a bioset, it'll
2874 * never fail. We're returning a bio right now but you can call btrfs_io_bio
2875 * for the appropriate container_of magic
2877 struct bio *btrfs_bio_alloc(u64 first_byte)
2881 bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, &btrfs_bioset);
2882 bio->bi_iter.bi_sector = first_byte >> 9;
2883 btrfs_io_bio_init(btrfs_io_bio(bio));
2887 struct bio *btrfs_bio_clone(struct bio *bio)
2889 struct btrfs_io_bio *btrfs_bio;
2892 /* Bio allocation backed by a bioset does not fail */
2893 new = bio_clone_fast(bio, GFP_NOFS, &btrfs_bioset);
2894 btrfs_bio = btrfs_io_bio(new);
2895 btrfs_io_bio_init(btrfs_bio);
2896 btrfs_bio->iter = bio->bi_iter;
2900 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs)
2904 /* Bio allocation backed by a bioset does not fail */
2905 bio = bio_alloc_bioset(GFP_NOFS, nr_iovecs, &btrfs_bioset);
2906 btrfs_io_bio_init(btrfs_io_bio(bio));
2910 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
2913 struct btrfs_io_bio *btrfs_bio;
2915 /* this will never fail when it's backed by a bioset */
2916 bio = bio_clone_fast(orig, GFP_NOFS, &btrfs_bioset);
2919 btrfs_bio = btrfs_io_bio(bio);
2920 btrfs_io_bio_init(btrfs_bio);
2922 bio_trim(bio, offset >> 9, size >> 9);
2923 btrfs_bio->iter = bio->bi_iter;
2928 * @opf: bio REQ_OP_* and REQ_* flags as one value
2929 * @tree: tree so we can call our merge_bio hook
2930 * @wbc: optional writeback control for io accounting
2931 * @page: page to add to the bio
2932 * @pg_offset: offset of the new bio or to check whether we are adding
2933 * a contiguous page to the previous one
2934 * @size: portion of page that we want to write
2935 * @offset: starting offset in the page
2936 * @bio_ret: must be valid pointer, newly allocated bio will be stored there
2937 * @end_io_func: end_io callback for new bio
2938 * @mirror_num: desired mirror to read/write
2939 * @prev_bio_flags: flags of previous bio to see if we can merge the current one
2940 * @bio_flags: flags of the current bio to see if we can merge them
2942 static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
2943 struct writeback_control *wbc,
2944 struct page *page, u64 offset,
2945 size_t size, unsigned long pg_offset,
2946 struct bio **bio_ret,
2947 bio_end_io_t end_io_func,
2949 unsigned long prev_bio_flags,
2950 unsigned long bio_flags,
2951 bool force_bio_submit)
2955 size_t page_size = min_t(size_t, size, PAGE_SIZE);
2956 sector_t sector = offset >> 9;
2962 bool can_merge = true;
2965 if (prev_bio_flags & EXTENT_BIO_COMPRESSED)
2966 contig = bio->bi_iter.bi_sector == sector;
2968 contig = bio_end_sector(bio) == sector;
2971 if (btrfs_bio_fits_in_stripe(page, page_size, bio, bio_flags))
2974 if (prev_bio_flags != bio_flags || !contig || !can_merge ||
2976 bio_add_page(bio, page, page_size, pg_offset) < page_size) {
2977 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
2985 wbc_account_cgroup_owner(wbc, page, page_size);
2990 bio = btrfs_bio_alloc(offset);
2991 bio_add_page(bio, page, page_size, pg_offset);
2992 bio->bi_end_io = end_io_func;
2993 bio->bi_private = tree;
2994 bio->bi_write_hint = page->mapping->host->i_write_hint;
2997 struct block_device *bdev;
2999 bdev = BTRFS_I(page->mapping->host)->root->fs_info->fs_devices->latest_bdev;
3000 bio_set_dev(bio, bdev);
3001 wbc_init_bio(wbc, bio);
3002 wbc_account_cgroup_owner(wbc, page, page_size);
3010 static void attach_extent_buffer_page(struct extent_buffer *eb,
3013 if (!PagePrivate(page)) {
3014 SetPagePrivate(page);
3016 set_page_private(page, (unsigned long)eb);
3018 WARN_ON(page->private != (unsigned long)eb);
3022 void set_page_extent_mapped(struct page *page)
3024 if (!PagePrivate(page)) {
3025 SetPagePrivate(page);
3027 set_page_private(page, EXTENT_PAGE_PRIVATE);
3031 static struct extent_map *
3032 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
3033 u64 start, u64 len, get_extent_t *get_extent,
3034 struct extent_map **em_cached)
3036 struct extent_map *em;
3038 if (em_cached && *em_cached) {
3040 if (extent_map_in_tree(em) && start >= em->start &&
3041 start < extent_map_end(em)) {
3042 refcount_inc(&em->refs);
3046 free_extent_map(em);
3050 em = get_extent(BTRFS_I(inode), page, pg_offset, start, len);
3051 if (em_cached && !IS_ERR_OR_NULL(em)) {
3053 refcount_inc(&em->refs);
3059 * basic readpage implementation. Locked extent state structs are inserted
3060 * into the tree that are removed when the IO is done (by the end_io
3062 * XXX JDM: This needs looking at to ensure proper page locking
3063 * return 0 on success, otherwise return error
3065 static int __do_readpage(struct extent_io_tree *tree,
3067 get_extent_t *get_extent,
3068 struct extent_map **em_cached,
3069 struct bio **bio, int mirror_num,
3070 unsigned long *bio_flags, unsigned int read_flags,
3073 struct inode *inode = page->mapping->host;
3074 u64 start = page_offset(page);
3075 const u64 end = start + PAGE_SIZE - 1;
3078 u64 last_byte = i_size_read(inode);
3081 struct extent_map *em;
3084 size_t pg_offset = 0;
3086 size_t disk_io_size;
3087 size_t blocksize = inode->i_sb->s_blocksize;
3088 unsigned long this_bio_flag = 0;
3090 set_page_extent_mapped(page);
3092 if (!PageUptodate(page)) {
3093 if (cleancache_get_page(page) == 0) {
3094 BUG_ON(blocksize != PAGE_SIZE);
3095 unlock_extent(tree, start, end);
3100 if (page->index == last_byte >> PAGE_SHIFT) {
3102 size_t zero_offset = offset_in_page(last_byte);
3105 iosize = PAGE_SIZE - zero_offset;
3106 userpage = kmap_atomic(page);
3107 memset(userpage + zero_offset, 0, iosize);
3108 flush_dcache_page(page);
3109 kunmap_atomic(userpage);
3112 while (cur <= end) {
3113 bool force_bio_submit = false;
3116 if (cur >= last_byte) {
3118 struct extent_state *cached = NULL;
3120 iosize = PAGE_SIZE - pg_offset;
3121 userpage = kmap_atomic(page);
3122 memset(userpage + pg_offset, 0, iosize);
3123 flush_dcache_page(page);
3124 kunmap_atomic(userpage);
3125 set_extent_uptodate(tree, cur, cur + iosize - 1,
3127 unlock_extent_cached(tree, cur,
3128 cur + iosize - 1, &cached);
3131 em = __get_extent_map(inode, page, pg_offset, cur,
3132 end - cur + 1, get_extent, em_cached);
3133 if (IS_ERR_OR_NULL(em)) {
3135 unlock_extent(tree, cur, end);
3138 extent_offset = cur - em->start;
3139 BUG_ON(extent_map_end(em) <= cur);
3142 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
3143 this_bio_flag |= EXTENT_BIO_COMPRESSED;
3144 extent_set_compress_type(&this_bio_flag,
3148 iosize = min(extent_map_end(em) - cur, end - cur + 1);
3149 cur_end = min(extent_map_end(em) - 1, end);
3150 iosize = ALIGN(iosize, blocksize);
3151 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
3152 disk_io_size = em->block_len;
3153 offset = em->block_start;
3155 offset = em->block_start + extent_offset;
3156 disk_io_size = iosize;
3158 block_start = em->block_start;
3159 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
3160 block_start = EXTENT_MAP_HOLE;
3163 * If we have a file range that points to a compressed extent
3164 * and it's followed by a consecutive file range that points to
3165 * to the same compressed extent (possibly with a different
3166 * offset and/or length, so it either points to the whole extent
3167 * or only part of it), we must make sure we do not submit a
3168 * single bio to populate the pages for the 2 ranges because
3169 * this makes the compressed extent read zero out the pages
3170 * belonging to the 2nd range. Imagine the following scenario:
3173 * [0 - 8K] [8K - 24K]
3176 * points to extent X, points to extent X,
3177 * offset 4K, length of 8K offset 0, length 16K
3179 * [extent X, compressed length = 4K uncompressed length = 16K]
3181 * If the bio to read the compressed extent covers both ranges,
3182 * it will decompress extent X into the pages belonging to the
3183 * first range and then it will stop, zeroing out the remaining
3184 * pages that belong to the other range that points to extent X.
3185 * So here we make sure we submit 2 bios, one for the first
3186 * range and another one for the third range. Both will target
3187 * the same physical extent from disk, but we can't currently
3188 * make the compressed bio endio callback populate the pages
3189 * for both ranges because each compressed bio is tightly
3190 * coupled with a single extent map, and each range can have
3191 * an extent map with a different offset value relative to the
3192 * uncompressed data of our extent and different lengths. This
3193 * is a corner case so we prioritize correctness over
3194 * non-optimal behavior (submitting 2 bios for the same extent).
3196 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3197 prev_em_start && *prev_em_start != (u64)-1 &&
3198 *prev_em_start != em->start)
3199 force_bio_submit = true;
3202 *prev_em_start = em->start;
3204 free_extent_map(em);
3207 /* we've found a hole, just zero and go on */
3208 if (block_start == EXTENT_MAP_HOLE) {
3210 struct extent_state *cached = NULL;
3212 userpage = kmap_atomic(page);
3213 memset(userpage + pg_offset, 0, iosize);
3214 flush_dcache_page(page);
3215 kunmap_atomic(userpage);
3217 set_extent_uptodate(tree, cur, cur + iosize - 1,
3219 unlock_extent_cached(tree, cur,
3220 cur + iosize - 1, &cached);
3222 pg_offset += iosize;
3225 /* the get_extent function already copied into the page */
3226 if (test_range_bit(tree, cur, cur_end,
3227 EXTENT_UPTODATE, 1, NULL)) {
3228 check_page_uptodate(tree, page);
3229 unlock_extent(tree, cur, cur + iosize - 1);
3231 pg_offset += iosize;
3234 /* we have an inline extent but it didn't get marked up
3235 * to date. Error out
3237 if (block_start == EXTENT_MAP_INLINE) {
3239 unlock_extent(tree, cur, cur + iosize - 1);
3241 pg_offset += iosize;
3245 ret = submit_extent_page(REQ_OP_READ | read_flags, tree, NULL,
3246 page, offset, disk_io_size,
3248 end_bio_extent_readpage, mirror_num,
3254 *bio_flags = this_bio_flag;
3257 unlock_extent(tree, cur, cur + iosize - 1);
3261 pg_offset += iosize;
3265 if (!PageError(page))
3266 SetPageUptodate(page);
3272 static inline void contiguous_readpages(struct extent_io_tree *tree,
3273 struct page *pages[], int nr_pages,
3275 struct extent_map **em_cached,
3277 unsigned long *bio_flags,
3280 struct btrfs_inode *inode = BTRFS_I(pages[0]->mapping->host);
3283 btrfs_lock_and_flush_ordered_range(tree, inode, start, end, NULL);
3285 for (index = 0; index < nr_pages; index++) {
3286 __do_readpage(tree, pages[index], btrfs_get_extent, em_cached,
3287 bio, 0, bio_flags, REQ_RAHEAD, prev_em_start);
3288 put_page(pages[index]);
3292 static int __extent_read_full_page(struct extent_io_tree *tree,
3294 get_extent_t *get_extent,
3295 struct bio **bio, int mirror_num,
3296 unsigned long *bio_flags,
3297 unsigned int read_flags)
3299 struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
3300 u64 start = page_offset(page);
3301 u64 end = start + PAGE_SIZE - 1;
3304 btrfs_lock_and_flush_ordered_range(tree, inode, start, end, NULL);
3306 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3307 bio_flags, read_flags, NULL);
3311 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3312 get_extent_t *get_extent, int mirror_num)
3314 struct bio *bio = NULL;
3315 unsigned long bio_flags = 0;
3318 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3321 ret = submit_one_bio(bio, mirror_num, bio_flags);
3325 static void update_nr_written(struct writeback_control *wbc,
3326 unsigned long nr_written)
3328 wbc->nr_to_write -= nr_written;
3332 * helper for __extent_writepage, doing all of the delayed allocation setup.
3334 * This returns 1 if btrfs_run_delalloc_range function did all the work required
3335 * to write the page (copy into inline extent). In this case the IO has
3336 * been started and the page is already unlocked.
3338 * This returns 0 if all went well (page still locked)
3339 * This returns < 0 if there were errors (page still locked)
3341 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3342 struct page *page, struct writeback_control *wbc,
3343 u64 delalloc_start, unsigned long *nr_written)
3345 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3347 u64 delalloc_to_write = 0;
3348 u64 delalloc_end = 0;
3350 int page_started = 0;
3353 while (delalloc_end < page_end) {
3354 found = find_lock_delalloc_range(inode, page,
3358 delalloc_start = delalloc_end + 1;
3361 ret = btrfs_run_delalloc_range(inode, page, delalloc_start,
3362 delalloc_end, &page_started, nr_written, wbc);
3366 * btrfs_run_delalloc_range should return < 0 for error
3367 * but just in case, we use > 0 here meaning the IO is
3368 * started, so we don't want to return > 0 unless
3369 * things are going well.
3371 ret = ret < 0 ? ret : -EIO;
3375 * delalloc_end is already one less than the total length, so
3376 * we don't subtract one from PAGE_SIZE
3378 delalloc_to_write += (delalloc_end - delalloc_start +
3379 PAGE_SIZE) >> PAGE_SHIFT;
3380 delalloc_start = delalloc_end + 1;
3382 if (wbc->nr_to_write < delalloc_to_write) {
3385 if (delalloc_to_write < thresh * 2)
3386 thresh = delalloc_to_write;
3387 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3391 /* did the fill delalloc function already unlock and start
3396 * we've unlocked the page, so we can't update
3397 * the mapping's writeback index, just update
3400 wbc->nr_to_write -= *nr_written;
3411 * helper for __extent_writepage. This calls the writepage start hooks,
3412 * and does the loop to map the page into extents and bios.
3414 * We return 1 if the IO is started and the page is unlocked,
3415 * 0 if all went well (page still locked)
3416 * < 0 if there were errors (page still locked)
3418 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3420 struct writeback_control *wbc,
3421 struct extent_page_data *epd,
3423 unsigned long nr_written,
3426 struct extent_io_tree *tree = epd->tree;
3427 u64 start = page_offset(page);
3428 u64 page_end = start + PAGE_SIZE - 1;
3434 struct extent_map *em;
3435 size_t pg_offset = 0;
3439 const unsigned int write_flags = wbc_to_write_flags(wbc);
3442 ret = btrfs_writepage_cow_fixup(page, start, page_end);
3444 /* Fixup worker will requeue */
3446 wbc->pages_skipped++;
3448 redirty_page_for_writepage(wbc, page);
3450 update_nr_written(wbc, nr_written);
3456 * we don't want to touch the inode after unlocking the page,
3457 * so we update the mapping writeback index now
3459 update_nr_written(wbc, nr_written + 1);
3462 blocksize = inode->i_sb->s_blocksize;
3464 while (cur <= end) {
3468 if (cur >= i_size) {
3469 btrfs_writepage_endio_finish_ordered(page, cur,
3473 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur,
3475 if (IS_ERR_OR_NULL(em)) {
3477 ret = PTR_ERR_OR_ZERO(em);
3481 extent_offset = cur - em->start;
3482 em_end = extent_map_end(em);
3483 BUG_ON(em_end <= cur);
3485 iosize = min(em_end - cur, end - cur + 1);
3486 iosize = ALIGN(iosize, blocksize);
3487 offset = em->block_start + extent_offset;
3488 block_start = em->block_start;
3489 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3490 free_extent_map(em);
3494 * compressed and inline extents are written through other
3497 if (compressed || block_start == EXTENT_MAP_HOLE ||
3498 block_start == EXTENT_MAP_INLINE) {
3502 btrfs_writepage_endio_finish_ordered(page, cur,
3503 cur + iosize - 1, 1);
3505 pg_offset += iosize;
3509 btrfs_set_range_writeback(tree, cur, cur + iosize - 1);
3510 if (!PageWriteback(page)) {
3511 btrfs_err(BTRFS_I(inode)->root->fs_info,
3512 "page %lu not writeback, cur %llu end %llu",
3513 page->index, cur, end);
3516 ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
3517 page, offset, iosize, pg_offset,
3519 end_bio_extent_writepage,
3523 if (PageWriteback(page))
3524 end_page_writeback(page);
3528 pg_offset += iosize;
3536 * the writepage semantics are similar to regular writepage. extent
3537 * records are inserted to lock ranges in the tree, and as dirty areas
3538 * are found, they are marked writeback. Then the lock bits are removed
3539 * and the end_io handler clears the writeback ranges
3541 * Return 0 if everything goes well.
3542 * Return <0 for error.
3544 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3545 struct extent_page_data *epd)
3547 struct inode *inode = page->mapping->host;
3548 u64 start = page_offset(page);
3549 u64 page_end = start + PAGE_SIZE - 1;
3553 loff_t i_size = i_size_read(inode);
3554 unsigned long end_index = i_size >> PAGE_SHIFT;
3555 unsigned long nr_written = 0;
3557 trace___extent_writepage(page, inode, wbc);
3559 WARN_ON(!PageLocked(page));
3561 ClearPageError(page);
3563 pg_offset = offset_in_page(i_size);
3564 if (page->index > end_index ||
3565 (page->index == end_index && !pg_offset)) {
3566 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3571 if (page->index == end_index) {
3574 userpage = kmap_atomic(page);
3575 memset(userpage + pg_offset, 0,
3576 PAGE_SIZE - pg_offset);
3577 kunmap_atomic(userpage);
3578 flush_dcache_page(page);
3581 set_page_extent_mapped(page);
3583 if (!epd->extent_locked) {
3584 ret = writepage_delalloc(inode, page, wbc, start, &nr_written);
3591 ret = __extent_writepage_io(inode, page, wbc, epd,
3592 i_size, nr_written, &nr);
3598 /* make sure the mapping tag for page dirty gets cleared */
3599 set_page_writeback(page);
3600 end_page_writeback(page);
3602 if (PageError(page)) {
3603 ret = ret < 0 ? ret : -EIO;
3604 end_extent_writepage(page, ret, start, page_end);
3611 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3613 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3614 TASK_UNINTERRUPTIBLE);
3617 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3619 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3620 smp_mb__after_atomic();
3621 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3625 * Lock eb pages and flush the bio if we can't the locks
3627 * Return 0 if nothing went wrong
3628 * Return >0 is same as 0, except bio is not submitted
3629 * Return <0 if something went wrong, no page is locked
3631 static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb,
3632 struct extent_page_data *epd)
3634 struct btrfs_fs_info *fs_info = eb->fs_info;
3635 int i, num_pages, failed_page_nr;
3639 if (!btrfs_try_tree_write_lock(eb)) {
3640 ret = flush_write_bio(epd);
3644 btrfs_tree_lock(eb);
3647 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3648 btrfs_tree_unlock(eb);
3652 ret = flush_write_bio(epd);
3658 wait_on_extent_buffer_writeback(eb);
3659 btrfs_tree_lock(eb);
3660 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3662 btrfs_tree_unlock(eb);
3667 * We need to do this to prevent races in people who check if the eb is
3668 * under IO since we can end up having no IO bits set for a short period
3671 spin_lock(&eb->refs_lock);
3672 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3673 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3674 spin_unlock(&eb->refs_lock);
3675 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3676 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
3678 fs_info->dirty_metadata_batch);
3681 spin_unlock(&eb->refs_lock);
3684 btrfs_tree_unlock(eb);
3689 num_pages = num_extent_pages(eb);
3690 for (i = 0; i < num_pages; i++) {
3691 struct page *p = eb->pages[i];
3693 if (!trylock_page(p)) {
3697 err = flush_write_bio(epd);
3711 /* Unlock already locked pages */
3712 for (i = 0; i < failed_page_nr; i++)
3713 unlock_page(eb->pages[i]);
3715 * Clear EXTENT_BUFFER_WRITEBACK and wake up anyone waiting on it.
3716 * Also set back EXTENT_BUFFER_DIRTY so future attempts to this eb can
3717 * be made and undo everything done before.
3719 btrfs_tree_lock(eb);
3720 spin_lock(&eb->refs_lock);
3721 set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3722 end_extent_buffer_writeback(eb);
3723 spin_unlock(&eb->refs_lock);
3724 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, eb->len,
3725 fs_info->dirty_metadata_batch);
3726 btrfs_clear_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3727 btrfs_tree_unlock(eb);
3731 static void set_btree_ioerr(struct page *page)
3733 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3734 struct btrfs_fs_info *fs_info;
3737 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3741 * If we error out, we should add back the dirty_metadata_bytes
3742 * to make it consistent.
3744 fs_info = eb->fs_info;
3745 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
3746 eb->len, fs_info->dirty_metadata_batch);
3749 * If writeback for a btree extent that doesn't belong to a log tree
3750 * failed, increment the counter transaction->eb_write_errors.
3751 * We do this because while the transaction is running and before it's
3752 * committing (when we call filemap_fdata[write|wait]_range against
3753 * the btree inode), we might have
3754 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3755 * returns an error or an error happens during writeback, when we're
3756 * committing the transaction we wouldn't know about it, since the pages
3757 * can be no longer dirty nor marked anymore for writeback (if a
3758 * subsequent modification to the extent buffer didn't happen before the
3759 * transaction commit), which makes filemap_fdata[write|wait]_range not
3760 * able to find the pages tagged with SetPageError at transaction
3761 * commit time. So if this happens we must abort the transaction,
3762 * otherwise we commit a super block with btree roots that point to
3763 * btree nodes/leafs whose content on disk is invalid - either garbage
3764 * or the content of some node/leaf from a past generation that got
3765 * cowed or deleted and is no longer valid.
3767 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3768 * not be enough - we need to distinguish between log tree extents vs
3769 * non-log tree extents, and the next filemap_fdatawait_range() call
3770 * will catch and clear such errors in the mapping - and that call might
3771 * be from a log sync and not from a transaction commit. Also, checking
3772 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3773 * not done and would not be reliable - the eb might have been released
3774 * from memory and reading it back again means that flag would not be
3775 * set (since it's a runtime flag, not persisted on disk).
3777 * Using the flags below in the btree inode also makes us achieve the
3778 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3779 * writeback for all dirty pages and before filemap_fdatawait_range()
3780 * is called, the writeback for all dirty pages had already finished
3781 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3782 * filemap_fdatawait_range() would return success, as it could not know
3783 * that writeback errors happened (the pages were no longer tagged for
3786 switch (eb->log_index) {
3788 set_bit(BTRFS_FS_BTREE_ERR, &eb->fs_info->flags);
3791 set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags);
3794 set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags);
3797 BUG(); /* unexpected, logic error */
3801 static void end_bio_extent_buffer_writepage(struct bio *bio)
3803 struct bio_vec *bvec;
3804 struct extent_buffer *eb;
3806 struct bvec_iter_all iter_all;
3808 ASSERT(!bio_flagged(bio, BIO_CLONED));
3809 bio_for_each_segment_all(bvec, bio, iter_all) {
3810 struct page *page = bvec->bv_page;
3812 eb = (struct extent_buffer *)page->private;
3814 done = atomic_dec_and_test(&eb->io_pages);
3816 if (bio->bi_status ||
3817 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3818 ClearPageUptodate(page);
3819 set_btree_ioerr(page);
3822 end_page_writeback(page);
3827 end_extent_buffer_writeback(eb);
3833 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3834 struct writeback_control *wbc,
3835 struct extent_page_data *epd)
3837 struct btrfs_fs_info *fs_info = eb->fs_info;
3838 struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
3839 u64 offset = eb->start;
3842 unsigned long start, end;
3843 unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META;
3846 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3847 num_pages = num_extent_pages(eb);
3848 atomic_set(&eb->io_pages, num_pages);
3850 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3851 nritems = btrfs_header_nritems(eb);
3852 if (btrfs_header_level(eb) > 0) {
3853 end = btrfs_node_key_ptr_offset(nritems);
3855 memzero_extent_buffer(eb, end, eb->len - end);
3859 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3861 start = btrfs_item_nr_offset(nritems);
3862 end = BTRFS_LEAF_DATA_OFFSET + leaf_data_end(eb);
3863 memzero_extent_buffer(eb, start, end - start);
3866 for (i = 0; i < num_pages; i++) {
3867 struct page *p = eb->pages[i];
3869 clear_page_dirty_for_io(p);
3870 set_page_writeback(p);
3871 ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
3872 p, offset, PAGE_SIZE, 0,
3874 end_bio_extent_buffer_writepage,
3878 if (PageWriteback(p))
3879 end_page_writeback(p);
3880 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3881 end_extent_buffer_writeback(eb);
3885 offset += PAGE_SIZE;
3886 update_nr_written(wbc, 1);
3890 if (unlikely(ret)) {
3891 for (; i < num_pages; i++) {
3892 struct page *p = eb->pages[i];
3893 clear_page_dirty_for_io(p);
3901 int btree_write_cache_pages(struct address_space *mapping,
3902 struct writeback_control *wbc)
3904 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3905 struct extent_buffer *eb, *prev_eb = NULL;
3906 struct extent_page_data epd = {
3910 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3914 int nr_to_write_done = 0;
3915 struct pagevec pvec;
3918 pgoff_t end; /* Inclusive */
3922 pagevec_init(&pvec);
3923 if (wbc->range_cyclic) {
3924 index = mapping->writeback_index; /* Start from prev offset */
3927 * Start from the beginning does not need to cycle over the
3928 * range, mark it as scanned.
3930 scanned = (index == 0);
3932 index = wbc->range_start >> PAGE_SHIFT;
3933 end = wbc->range_end >> PAGE_SHIFT;
3936 if (wbc->sync_mode == WB_SYNC_ALL)
3937 tag = PAGECACHE_TAG_TOWRITE;
3939 tag = PAGECACHE_TAG_DIRTY;
3941 if (wbc->sync_mode == WB_SYNC_ALL)
3942 tag_pages_for_writeback(mapping, index, end);
3943 while (!done && !nr_to_write_done && (index <= end) &&
3944 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
3948 for (i = 0; i < nr_pages; i++) {
3949 struct page *page = pvec.pages[i];
3951 if (!PagePrivate(page))
3954 spin_lock(&mapping->private_lock);
3955 if (!PagePrivate(page)) {
3956 spin_unlock(&mapping->private_lock);
3960 eb = (struct extent_buffer *)page->private;
3963 * Shouldn't happen and normally this would be a BUG_ON
3964 * but no sense in crashing the users box for something
3965 * we can survive anyway.
3968 spin_unlock(&mapping->private_lock);
3972 if (eb == prev_eb) {
3973 spin_unlock(&mapping->private_lock);
3977 ret = atomic_inc_not_zero(&eb->refs);
3978 spin_unlock(&mapping->private_lock);
3983 ret = lock_extent_buffer_for_io(eb, &epd);
3985 free_extent_buffer(eb);
3987 } else if (ret < 0) {
3989 free_extent_buffer(eb);
3993 ret = write_one_eb(eb, wbc, &epd);
3996 free_extent_buffer(eb);
3999 free_extent_buffer(eb);
4002 * the filesystem may choose to bump up nr_to_write.
4003 * We have to make sure to honor the new nr_to_write
4006 nr_to_write_done = wbc->nr_to_write <= 0;
4008 pagevec_release(&pvec);
4011 if (!scanned && !done) {
4013 * We hit the last page and there is more work to be done: wrap
4014 * back to the start of the file
4022 end_write_bio(&epd, ret);
4025 ret = flush_write_bio(&epd);
4030 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
4031 * @mapping: address space structure to write
4032 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
4033 * @data: data passed to __extent_writepage function
4035 * If a page is already under I/O, write_cache_pages() skips it, even
4036 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
4037 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
4038 * and msync() need to guarantee that all the data which was dirty at the time
4039 * the call was made get new I/O started against them. If wbc->sync_mode is
4040 * WB_SYNC_ALL then we were called for data integrity and we must wait for
4041 * existing IO to complete.
4043 static int extent_write_cache_pages(struct address_space *mapping,
4044 struct writeback_control *wbc,
4045 struct extent_page_data *epd)
4047 struct inode *inode = mapping->host;
4050 int nr_to_write_done = 0;
4051 struct pagevec pvec;
4054 pgoff_t end; /* Inclusive */
4056 int range_whole = 0;
4061 * We have to hold onto the inode so that ordered extents can do their
4062 * work when the IO finishes. The alternative to this is failing to add
4063 * an ordered extent if the igrab() fails there and that is a huge pain
4064 * to deal with, so instead just hold onto the inode throughout the
4065 * writepages operation. If it fails here we are freeing up the inode
4066 * anyway and we'd rather not waste our time writing out stuff that is
4067 * going to be truncated anyway.
4072 pagevec_init(&pvec);
4073 if (wbc->range_cyclic) {
4074 index = mapping->writeback_index; /* Start from prev offset */
4077 * Start from the beginning does not need to cycle over the
4078 * range, mark it as scanned.
4080 scanned = (index == 0);
4082 index = wbc->range_start >> PAGE_SHIFT;
4083 end = wbc->range_end >> PAGE_SHIFT;
4084 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
4090 * We do the tagged writepage as long as the snapshot flush bit is set
4091 * and we are the first one who do the filemap_flush() on this inode.
4093 * The nr_to_write == LONG_MAX is needed to make sure other flushers do
4094 * not race in and drop the bit.
4096 if (range_whole && wbc->nr_to_write == LONG_MAX &&
4097 test_and_clear_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
4098 &BTRFS_I(inode)->runtime_flags))
4099 wbc->tagged_writepages = 1;
4101 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
4102 tag = PAGECACHE_TAG_TOWRITE;
4104 tag = PAGECACHE_TAG_DIRTY;
4106 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
4107 tag_pages_for_writeback(mapping, index, end);
4109 while (!done && !nr_to_write_done && (index <= end) &&
4110 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping,
4111 &index, end, tag))) {
4114 for (i = 0; i < nr_pages; i++) {
4115 struct page *page = pvec.pages[i];
4117 done_index = page->index + 1;
4119 * At this point we hold neither the i_pages lock nor
4120 * the page lock: the page may be truncated or
4121 * invalidated (changing page->mapping to NULL),
4122 * or even swizzled back from swapper_space to
4123 * tmpfs file mapping
4125 if (!trylock_page(page)) {
4126 ret = flush_write_bio(epd);
4131 if (unlikely(page->mapping != mapping)) {
4136 if (wbc->sync_mode != WB_SYNC_NONE) {
4137 if (PageWriteback(page)) {
4138 ret = flush_write_bio(epd);
4141 wait_on_page_writeback(page);
4144 if (PageWriteback(page) ||
4145 !clear_page_dirty_for_io(page)) {
4150 ret = __extent_writepage(page, wbc, epd);
4157 * the filesystem may choose to bump up nr_to_write.
4158 * We have to make sure to honor the new nr_to_write
4161 nr_to_write_done = wbc->nr_to_write <= 0;
4163 pagevec_release(&pvec);
4166 if (!scanned && !done) {
4168 * We hit the last page and there is more work to be done: wrap
4169 * back to the start of the file
4175 * If we're looping we could run into a page that is locked by a
4176 * writer and that writer could be waiting on writeback for a
4177 * page in our current bio, and thus deadlock, so flush the
4180 ret = flush_write_bio(epd);
4185 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4186 mapping->writeback_index = done_index;
4188 btrfs_add_delayed_iput(inode);
4192 int extent_write_full_page(struct page *page, struct writeback_control *wbc)
4195 struct extent_page_data epd = {
4197 .tree = &BTRFS_I(page->mapping->host)->io_tree,
4199 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4202 ret = __extent_writepage(page, wbc, &epd);
4205 end_write_bio(&epd, ret);
4209 ret = flush_write_bio(&epd);
4214 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
4218 struct address_space *mapping = inode->i_mapping;
4219 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
4221 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4224 struct extent_page_data epd = {
4228 .sync_io = mode == WB_SYNC_ALL,
4230 struct writeback_control wbc_writepages = {
4232 .nr_to_write = nr_pages * 2,
4233 .range_start = start,
4234 .range_end = end + 1,
4235 /* We're called from an async helper function */
4236 .punt_to_cgroup = 1,
4237 .no_cgroup_owner = 1,
4240 wbc_attach_fdatawrite_inode(&wbc_writepages, inode);
4241 while (start <= end) {
4242 page = find_get_page(mapping, start >> PAGE_SHIFT);
4243 if (clear_page_dirty_for_io(page))
4244 ret = __extent_writepage(page, &wbc_writepages, &epd);
4246 btrfs_writepage_endio_finish_ordered(page, start,
4247 start + PAGE_SIZE - 1, 1);
4256 ret = flush_write_bio(&epd);
4258 end_write_bio(&epd, ret);
4260 wbc_detach_inode(&wbc_writepages);
4264 int extent_writepages(struct address_space *mapping,
4265 struct writeback_control *wbc)
4268 struct extent_page_data epd = {
4270 .tree = &BTRFS_I(mapping->host)->io_tree,
4272 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4275 ret = extent_write_cache_pages(mapping, wbc, &epd);
4278 end_write_bio(&epd, ret);
4281 ret = flush_write_bio(&epd);
4285 int extent_readpages(struct address_space *mapping, struct list_head *pages,
4288 struct bio *bio = NULL;
4289 unsigned long bio_flags = 0;
4290 struct page *pagepool[16];
4291 struct extent_map *em_cached = NULL;
4292 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
4294 u64 prev_em_start = (u64)-1;
4296 while (!list_empty(pages)) {
4299 for (nr = 0; nr < ARRAY_SIZE(pagepool) && !list_empty(pages);) {
4300 struct page *page = lru_to_page(pages);
4302 prefetchw(&page->flags);
4303 list_del(&page->lru);
4304 if (add_to_page_cache_lru(page, mapping, page->index,
4305 readahead_gfp_mask(mapping))) {
4310 pagepool[nr++] = page;
4311 contig_end = page_offset(page) + PAGE_SIZE - 1;
4315 u64 contig_start = page_offset(pagepool[0]);
4317 ASSERT(contig_start + nr * PAGE_SIZE - 1 == contig_end);
4319 contiguous_readpages(tree, pagepool, nr, contig_start,
4320 contig_end, &em_cached, &bio, &bio_flags,
4326 free_extent_map(em_cached);
4329 return submit_one_bio(bio, 0, bio_flags);
4334 * basic invalidatepage code, this waits on any locked or writeback
4335 * ranges corresponding to the page, and then deletes any extent state
4336 * records from the tree
4338 int extent_invalidatepage(struct extent_io_tree *tree,
4339 struct page *page, unsigned long offset)
4341 struct extent_state *cached_state = NULL;
4342 u64 start = page_offset(page);
4343 u64 end = start + PAGE_SIZE - 1;
4344 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4346 start += ALIGN(offset, blocksize);
4350 lock_extent_bits(tree, start, end, &cached_state);
4351 wait_on_page_writeback(page);
4352 clear_extent_bit(tree, start, end, EXTENT_LOCKED | EXTENT_DELALLOC |
4353 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state);
4358 * a helper for releasepage, this tests for areas of the page that
4359 * are locked or under IO and drops the related state bits if it is safe
4362 static int try_release_extent_state(struct extent_io_tree *tree,
4363 struct page *page, gfp_t mask)
4365 u64 start = page_offset(page);
4366 u64 end = start + PAGE_SIZE - 1;
4369 if (test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL)) {
4373 * at this point we can safely clear everything except the
4374 * locked bit and the nodatasum bit
4376 ret = __clear_extent_bit(tree, start, end,
4377 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4378 0, 0, NULL, mask, NULL);
4380 /* if clear_extent_bit failed for enomem reasons,
4381 * we can't allow the release to continue.
4392 * a helper for releasepage. As long as there are no locked extents
4393 * in the range corresponding to the page, both state records and extent
4394 * map records are removed
4396 int try_release_extent_mapping(struct page *page, gfp_t mask)
4398 struct extent_map *em;
4399 u64 start = page_offset(page);
4400 u64 end = start + PAGE_SIZE - 1;
4401 struct btrfs_inode *btrfs_inode = BTRFS_I(page->mapping->host);
4402 struct extent_io_tree *tree = &btrfs_inode->io_tree;
4403 struct extent_map_tree *map = &btrfs_inode->extent_tree;
4405 if (gfpflags_allow_blocking(mask) &&
4406 page->mapping->host->i_size > SZ_16M) {
4408 while (start <= end) {
4409 len = end - start + 1;
4410 write_lock(&map->lock);
4411 em = lookup_extent_mapping(map, start, len);
4413 write_unlock(&map->lock);
4416 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4417 em->start != start) {
4418 write_unlock(&map->lock);
4419 free_extent_map(em);
4422 if (!test_range_bit(tree, em->start,
4423 extent_map_end(em) - 1,
4424 EXTENT_LOCKED, 0, NULL)) {
4425 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4426 &btrfs_inode->runtime_flags);
4427 remove_extent_mapping(map, em);
4428 /* once for the rb tree */
4429 free_extent_map(em);
4431 start = extent_map_end(em);
4432 write_unlock(&map->lock);
4435 free_extent_map(em);
4438 return try_release_extent_state(tree, page, mask);
4442 * helper function for fiemap, which doesn't want to see any holes.
4443 * This maps until we find something past 'last'
4445 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4446 u64 offset, u64 last)
4448 u64 sectorsize = btrfs_inode_sectorsize(inode);
4449 struct extent_map *em;
4456 len = last - offset;
4459 len = ALIGN(len, sectorsize);
4460 em = btrfs_get_extent_fiemap(BTRFS_I(inode), offset, len);
4461 if (IS_ERR_OR_NULL(em))
4464 /* if this isn't a hole return it */
4465 if (em->block_start != EXTENT_MAP_HOLE)
4468 /* this is a hole, advance to the next extent */
4469 offset = extent_map_end(em);
4470 free_extent_map(em);
4478 * To cache previous fiemap extent
4480 * Will be used for merging fiemap extent
4482 struct fiemap_cache {
4491 * Helper to submit fiemap extent.
4493 * Will try to merge current fiemap extent specified by @offset, @phys,
4494 * @len and @flags with cached one.
4495 * And only when we fails to merge, cached one will be submitted as
4498 * Return value is the same as fiemap_fill_next_extent().
4500 static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
4501 struct fiemap_cache *cache,
4502 u64 offset, u64 phys, u64 len, u32 flags)
4510 * Sanity check, extent_fiemap() should have ensured that new
4511 * fiemap extent won't overlap with cached one.
4514 * NOTE: Physical address can overlap, due to compression
4516 if (cache->offset + cache->len > offset) {
4522 * Only merges fiemap extents if
4523 * 1) Their logical addresses are continuous
4525 * 2) Their physical addresses are continuous
4526 * So truly compressed (physical size smaller than logical size)
4527 * extents won't get merged with each other
4529 * 3) Share same flags except FIEMAP_EXTENT_LAST
4530 * So regular extent won't get merged with prealloc extent
4532 if (cache->offset + cache->len == offset &&
4533 cache->phys + cache->len == phys &&
4534 (cache->flags & ~FIEMAP_EXTENT_LAST) ==
4535 (flags & ~FIEMAP_EXTENT_LAST)) {
4537 cache->flags |= flags;
4538 goto try_submit_last;
4541 /* Not mergeable, need to submit cached one */
4542 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4543 cache->len, cache->flags);
4544 cache->cached = false;
4548 cache->cached = true;
4549 cache->offset = offset;
4552 cache->flags = flags;
4554 if (cache->flags & FIEMAP_EXTENT_LAST) {
4555 ret = fiemap_fill_next_extent(fieinfo, cache->offset,
4556 cache->phys, cache->len, cache->flags);
4557 cache->cached = false;
4563 * Emit last fiemap cache
4565 * The last fiemap cache may still be cached in the following case:
4567 * |<- Fiemap range ->|
4568 * |<------------ First extent ----------->|
4570 * In this case, the first extent range will be cached but not emitted.
4571 * So we must emit it before ending extent_fiemap().
4573 static int emit_last_fiemap_cache(struct fiemap_extent_info *fieinfo,
4574 struct fiemap_cache *cache)
4581 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4582 cache->len, cache->flags);
4583 cache->cached = false;
4589 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4590 __u64 start, __u64 len)
4594 u64 max = start + len;
4598 u64 last_for_get_extent = 0;
4600 u64 isize = i_size_read(inode);
4601 struct btrfs_key found_key;
4602 struct extent_map *em = NULL;
4603 struct extent_state *cached_state = NULL;
4604 struct btrfs_path *path;
4605 struct btrfs_root *root = BTRFS_I(inode)->root;
4606 struct fiemap_cache cache = { 0 };
4607 struct ulist *roots;
4608 struct ulist *tmp_ulist;
4617 path = btrfs_alloc_path();
4620 path->leave_spinning = 1;
4622 roots = ulist_alloc(GFP_KERNEL);
4623 tmp_ulist = ulist_alloc(GFP_KERNEL);
4624 if (!roots || !tmp_ulist) {
4626 goto out_free_ulist;
4629 start = round_down(start, btrfs_inode_sectorsize(inode));
4630 len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
4633 * lookup the last file extent. We're not using i_size here
4634 * because there might be preallocation past i_size
4636 ret = btrfs_lookup_file_extent(NULL, root, path,
4637 btrfs_ino(BTRFS_I(inode)), -1, 0);
4639 goto out_free_ulist;
4647 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4648 found_type = found_key.type;
4650 /* No extents, but there might be delalloc bits */
4651 if (found_key.objectid != btrfs_ino(BTRFS_I(inode)) ||
4652 found_type != BTRFS_EXTENT_DATA_KEY) {
4653 /* have to trust i_size as the end */
4655 last_for_get_extent = isize;
4658 * remember the start of the last extent. There are a
4659 * bunch of different factors that go into the length of the
4660 * extent, so its much less complex to remember where it started
4662 last = found_key.offset;
4663 last_for_get_extent = last + 1;
4665 btrfs_release_path(path);
4668 * we might have some extents allocated but more delalloc past those
4669 * extents. so, we trust isize unless the start of the last extent is
4674 last_for_get_extent = isize;
4677 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4680 em = get_extent_skip_holes(inode, start, last_for_get_extent);
4689 u64 offset_in_extent = 0;
4691 /* break if the extent we found is outside the range */
4692 if (em->start >= max || extent_map_end(em) < off)
4696 * get_extent may return an extent that starts before our
4697 * requested range. We have to make sure the ranges
4698 * we return to fiemap always move forward and don't
4699 * overlap, so adjust the offsets here
4701 em_start = max(em->start, off);
4704 * record the offset from the start of the extent
4705 * for adjusting the disk offset below. Only do this if the
4706 * extent isn't compressed since our in ram offset may be past
4707 * what we have actually allocated on disk.
4709 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4710 offset_in_extent = em_start - em->start;
4711 em_end = extent_map_end(em);
4712 em_len = em_end - em_start;
4714 if (em->block_start < EXTENT_MAP_LAST_BYTE)
4715 disko = em->block_start + offset_in_extent;
4720 * bump off for our next call to get_extent
4722 off = extent_map_end(em);
4726 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4728 flags |= FIEMAP_EXTENT_LAST;
4729 } else if (em->block_start == EXTENT_MAP_INLINE) {
4730 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4731 FIEMAP_EXTENT_NOT_ALIGNED);
4732 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4733 flags |= (FIEMAP_EXTENT_DELALLOC |
4734 FIEMAP_EXTENT_UNKNOWN);
4735 } else if (fieinfo->fi_extents_max) {
4736 u64 bytenr = em->block_start -
4737 (em->start - em->orig_start);
4740 * As btrfs supports shared space, this information
4741 * can be exported to userspace tools via
4742 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4743 * then we're just getting a count and we can skip the
4746 ret = btrfs_check_shared(root,
4747 btrfs_ino(BTRFS_I(inode)),
4748 bytenr, roots, tmp_ulist);
4752 flags |= FIEMAP_EXTENT_SHARED;
4755 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4756 flags |= FIEMAP_EXTENT_ENCODED;
4757 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4758 flags |= FIEMAP_EXTENT_UNWRITTEN;
4760 free_extent_map(em);
4762 if ((em_start >= last) || em_len == (u64)-1 ||
4763 (last == (u64)-1 && isize <= em_end)) {
4764 flags |= FIEMAP_EXTENT_LAST;
4768 /* now scan forward to see if this is really the last extent. */
4769 em = get_extent_skip_holes(inode, off, last_for_get_extent);
4775 flags |= FIEMAP_EXTENT_LAST;
4778 ret = emit_fiemap_extent(fieinfo, &cache, em_start, disko,
4788 ret = emit_last_fiemap_cache(fieinfo, &cache);
4789 free_extent_map(em);
4791 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4795 btrfs_free_path(path);
4797 ulist_free(tmp_ulist);
4801 static void __free_extent_buffer(struct extent_buffer *eb)
4803 btrfs_leak_debug_del(&eb->leak_list);
4804 kmem_cache_free(extent_buffer_cache, eb);
4807 int extent_buffer_under_io(struct extent_buffer *eb)
4809 return (atomic_read(&eb->io_pages) ||
4810 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4811 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4815 * Release all pages attached to the extent buffer.
4817 static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb)
4821 int mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
4823 BUG_ON(extent_buffer_under_io(eb));
4825 num_pages = num_extent_pages(eb);
4826 for (i = 0; i < num_pages; i++) {
4827 struct page *page = eb->pages[i];
4832 spin_lock(&page->mapping->private_lock);
4834 * We do this since we'll remove the pages after we've
4835 * removed the eb from the radix tree, so we could race
4836 * and have this page now attached to the new eb. So
4837 * only clear page_private if it's still connected to
4840 if (PagePrivate(page) &&
4841 page->private == (unsigned long)eb) {
4842 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4843 BUG_ON(PageDirty(page));
4844 BUG_ON(PageWriteback(page));
4846 * We need to make sure we haven't be attached
4849 ClearPagePrivate(page);
4850 set_page_private(page, 0);
4851 /* One for the page private */
4856 spin_unlock(&page->mapping->private_lock);
4858 /* One for when we allocated the page */
4864 * Helper for releasing the extent buffer.
4866 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4868 btrfs_release_extent_buffer_pages(eb);
4869 __free_extent_buffer(eb);
4872 static struct extent_buffer *
4873 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4876 struct extent_buffer *eb = NULL;
4878 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4881 eb->fs_info = fs_info;
4883 rwlock_init(&eb->lock);
4884 atomic_set(&eb->blocking_readers, 0);
4885 eb->blocking_writers = 0;
4886 eb->lock_nested = false;
4887 init_waitqueue_head(&eb->write_lock_wq);
4888 init_waitqueue_head(&eb->read_lock_wq);
4890 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4892 spin_lock_init(&eb->refs_lock);
4893 atomic_set(&eb->refs, 1);
4894 atomic_set(&eb->io_pages, 0);
4897 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4899 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4900 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4901 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4903 #ifdef CONFIG_BTRFS_DEBUG
4904 eb->spinning_writers = 0;
4905 atomic_set(&eb->spinning_readers, 0);
4906 atomic_set(&eb->read_locks, 0);
4907 eb->write_locks = 0;
4913 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4917 struct extent_buffer *new;
4918 int num_pages = num_extent_pages(src);
4920 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
4924 for (i = 0; i < num_pages; i++) {
4925 p = alloc_page(GFP_NOFS);
4927 btrfs_release_extent_buffer(new);
4930 attach_extent_buffer_page(new, p);
4931 WARN_ON(PageDirty(p));
4934 copy_page(page_address(p), page_address(src->pages[i]));
4937 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4938 set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags);
4943 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4944 u64 start, unsigned long len)
4946 struct extent_buffer *eb;
4950 eb = __alloc_extent_buffer(fs_info, start, len);
4954 num_pages = num_extent_pages(eb);
4955 for (i = 0; i < num_pages; i++) {
4956 eb->pages[i] = alloc_page(GFP_NOFS);
4960 set_extent_buffer_uptodate(eb);
4961 btrfs_set_header_nritems(eb, 0);
4962 set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
4967 __free_page(eb->pages[i - 1]);
4968 __free_extent_buffer(eb);
4972 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4975 return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
4978 static void check_buffer_tree_ref(struct extent_buffer *eb)
4981 /* the ref bit is tricky. We have to make sure it is set
4982 * if we have the buffer dirty. Otherwise the
4983 * code to free a buffer can end up dropping a dirty
4986 * Once the ref bit is set, it won't go away while the
4987 * buffer is dirty or in writeback, and it also won't
4988 * go away while we have the reference count on the
4991 * We can't just set the ref bit without bumping the
4992 * ref on the eb because free_extent_buffer might
4993 * see the ref bit and try to clear it. If this happens
4994 * free_extent_buffer might end up dropping our original
4995 * ref by mistake and freeing the page before we are able
4996 * to add one more ref.
4998 * So bump the ref count first, then set the bit. If someone
4999 * beat us to it, drop the ref we added.
5001 refs = atomic_read(&eb->refs);
5002 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5005 spin_lock(&eb->refs_lock);
5006 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5007 atomic_inc(&eb->refs);
5008 spin_unlock(&eb->refs_lock);
5011 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
5012 struct page *accessed)
5016 check_buffer_tree_ref(eb);
5018 num_pages = num_extent_pages(eb);
5019 for (i = 0; i < num_pages; i++) {
5020 struct page *p = eb->pages[i];
5023 mark_page_accessed(p);
5027 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
5030 struct extent_buffer *eb;
5033 eb = radix_tree_lookup(&fs_info->buffer_radix,
5034 start >> PAGE_SHIFT);
5035 if (eb && atomic_inc_not_zero(&eb->refs)) {
5038 * Lock our eb's refs_lock to avoid races with
5039 * free_extent_buffer. When we get our eb it might be flagged
5040 * with EXTENT_BUFFER_STALE and another task running
5041 * free_extent_buffer might have seen that flag set,
5042 * eb->refs == 2, that the buffer isn't under IO (dirty and
5043 * writeback flags not set) and it's still in the tree (flag
5044 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
5045 * of decrementing the extent buffer's reference count twice.
5046 * So here we could race and increment the eb's reference count,
5047 * clear its stale flag, mark it as dirty and drop our reference
5048 * before the other task finishes executing free_extent_buffer,
5049 * which would later result in an attempt to free an extent
5050 * buffer that is dirty.
5052 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
5053 spin_lock(&eb->refs_lock);
5054 spin_unlock(&eb->refs_lock);
5056 mark_extent_buffer_accessed(eb, NULL);
5064 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5065 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
5068 struct extent_buffer *eb, *exists = NULL;
5071 eb = find_extent_buffer(fs_info, start);
5074 eb = alloc_dummy_extent_buffer(fs_info, start);
5076 return ERR_PTR(-ENOMEM);
5077 eb->fs_info = fs_info;
5079 ret = radix_tree_preload(GFP_NOFS);
5081 exists = ERR_PTR(ret);
5084 spin_lock(&fs_info->buffer_lock);
5085 ret = radix_tree_insert(&fs_info->buffer_radix,
5086 start >> PAGE_SHIFT, eb);
5087 spin_unlock(&fs_info->buffer_lock);
5088 radix_tree_preload_end();
5089 if (ret == -EEXIST) {
5090 exists = find_extent_buffer(fs_info, start);
5096 check_buffer_tree_ref(eb);
5097 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5101 btrfs_release_extent_buffer(eb);
5106 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
5109 unsigned long len = fs_info->nodesize;
5112 unsigned long index = start >> PAGE_SHIFT;
5113 struct extent_buffer *eb;
5114 struct extent_buffer *exists = NULL;
5116 struct address_space *mapping = fs_info->btree_inode->i_mapping;
5120 if (!IS_ALIGNED(start, fs_info->sectorsize)) {
5121 btrfs_err(fs_info, "bad tree block start %llu", start);
5122 return ERR_PTR(-EINVAL);
5125 eb = find_extent_buffer(fs_info, start);
5129 eb = __alloc_extent_buffer(fs_info, start, len);
5131 return ERR_PTR(-ENOMEM);
5133 num_pages = num_extent_pages(eb);
5134 for (i = 0; i < num_pages; i++, index++) {
5135 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
5137 exists = ERR_PTR(-ENOMEM);
5141 spin_lock(&mapping->private_lock);
5142 if (PagePrivate(p)) {
5144 * We could have already allocated an eb for this page
5145 * and attached one so lets see if we can get a ref on
5146 * the existing eb, and if we can we know it's good and
5147 * we can just return that one, else we know we can just
5148 * overwrite page->private.
5150 exists = (struct extent_buffer *)p->private;
5151 if (atomic_inc_not_zero(&exists->refs)) {
5152 spin_unlock(&mapping->private_lock);
5155 mark_extent_buffer_accessed(exists, p);
5161 * Do this so attach doesn't complain and we need to
5162 * drop the ref the old guy had.
5164 ClearPagePrivate(p);
5165 WARN_ON(PageDirty(p));
5168 attach_extent_buffer_page(eb, p);
5169 spin_unlock(&mapping->private_lock);
5170 WARN_ON(PageDirty(p));
5172 if (!PageUptodate(p))
5176 * We can't unlock the pages just yet since the extent buffer
5177 * hasn't been properly inserted in the radix tree, this
5178 * opens a race with btree_releasepage which can free a page
5179 * while we are still filling in all pages for the buffer and
5184 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5186 ret = radix_tree_preload(GFP_NOFS);
5188 exists = ERR_PTR(ret);
5192 spin_lock(&fs_info->buffer_lock);
5193 ret = radix_tree_insert(&fs_info->buffer_radix,
5194 start >> PAGE_SHIFT, eb);
5195 spin_unlock(&fs_info->buffer_lock);
5196 radix_tree_preload_end();
5197 if (ret == -EEXIST) {
5198 exists = find_extent_buffer(fs_info, start);
5204 /* add one reference for the tree */
5205 check_buffer_tree_ref(eb);
5206 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5209 * Now it's safe to unlock the pages because any calls to
5210 * btree_releasepage will correctly detect that a page belongs to a
5211 * live buffer and won't free them prematurely.
5213 for (i = 0; i < num_pages; i++)
5214 unlock_page(eb->pages[i]);
5218 WARN_ON(!atomic_dec_and_test(&eb->refs));
5219 for (i = 0; i < num_pages; i++) {
5221 unlock_page(eb->pages[i]);
5224 btrfs_release_extent_buffer(eb);
5228 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5230 struct extent_buffer *eb =
5231 container_of(head, struct extent_buffer, rcu_head);
5233 __free_extent_buffer(eb);
5236 static int release_extent_buffer(struct extent_buffer *eb)
5238 lockdep_assert_held(&eb->refs_lock);
5240 WARN_ON(atomic_read(&eb->refs) == 0);
5241 if (atomic_dec_and_test(&eb->refs)) {
5242 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5243 struct btrfs_fs_info *fs_info = eb->fs_info;
5245 spin_unlock(&eb->refs_lock);
5247 spin_lock(&fs_info->buffer_lock);
5248 radix_tree_delete(&fs_info->buffer_radix,
5249 eb->start >> PAGE_SHIFT);
5250 spin_unlock(&fs_info->buffer_lock);
5252 spin_unlock(&eb->refs_lock);
5255 /* Should be safe to release our pages at this point */
5256 btrfs_release_extent_buffer_pages(eb);
5257 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5258 if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))) {
5259 __free_extent_buffer(eb);
5263 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5266 spin_unlock(&eb->refs_lock);
5271 void free_extent_buffer(struct extent_buffer *eb)
5279 refs = atomic_read(&eb->refs);
5280 if ((!test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) && refs <= 3)
5281 || (test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) &&
5284 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5289 spin_lock(&eb->refs_lock);
5290 if (atomic_read(&eb->refs) == 2 &&
5291 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5292 !extent_buffer_under_io(eb) &&
5293 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5294 atomic_dec(&eb->refs);
5297 * I know this is terrible, but it's temporary until we stop tracking
5298 * the uptodate bits and such for the extent buffers.
5300 release_extent_buffer(eb);
5303 void free_extent_buffer_stale(struct extent_buffer *eb)
5308 spin_lock(&eb->refs_lock);
5309 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5311 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5312 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5313 atomic_dec(&eb->refs);
5314 release_extent_buffer(eb);
5317 void clear_extent_buffer_dirty(struct extent_buffer *eb)
5323 num_pages = num_extent_pages(eb);
5325 for (i = 0; i < num_pages; i++) {
5326 page = eb->pages[i];
5327 if (!PageDirty(page))
5331 WARN_ON(!PagePrivate(page));
5333 clear_page_dirty_for_io(page);
5334 xa_lock_irq(&page->mapping->i_pages);
5335 if (!PageDirty(page))
5336 __xa_clear_mark(&page->mapping->i_pages,
5337 page_index(page), PAGECACHE_TAG_DIRTY);
5338 xa_unlock_irq(&page->mapping->i_pages);
5339 ClearPageError(page);
5342 WARN_ON(atomic_read(&eb->refs) == 0);
5345 bool set_extent_buffer_dirty(struct extent_buffer *eb)
5351 check_buffer_tree_ref(eb);
5353 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5355 num_pages = num_extent_pages(eb);
5356 WARN_ON(atomic_read(&eb->refs) == 0);
5357 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5360 for (i = 0; i < num_pages; i++)
5361 set_page_dirty(eb->pages[i]);
5363 #ifdef CONFIG_BTRFS_DEBUG
5364 for (i = 0; i < num_pages; i++)
5365 ASSERT(PageDirty(eb->pages[i]));
5371 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5377 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5378 num_pages = num_extent_pages(eb);
5379 for (i = 0; i < num_pages; i++) {
5380 page = eb->pages[i];
5382 ClearPageUptodate(page);
5386 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5392 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5393 num_pages = num_extent_pages(eb);
5394 for (i = 0; i < num_pages; i++) {
5395 page = eb->pages[i];
5396 SetPageUptodate(page);
5400 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num)
5406 int locked_pages = 0;
5407 int all_uptodate = 1;
5409 unsigned long num_reads = 0;
5410 struct bio *bio = NULL;
5411 unsigned long bio_flags = 0;
5412 struct extent_io_tree *tree = &BTRFS_I(eb->fs_info->btree_inode)->io_tree;
5414 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5417 num_pages = num_extent_pages(eb);
5418 for (i = 0; i < num_pages; i++) {
5419 page = eb->pages[i];
5420 if (wait == WAIT_NONE) {
5421 if (!trylock_page(page))
5429 * We need to firstly lock all pages to make sure that
5430 * the uptodate bit of our pages won't be affected by
5431 * clear_extent_buffer_uptodate().
5433 for (i = 0; i < num_pages; i++) {
5434 page = eb->pages[i];
5435 if (!PageUptodate(page)) {
5442 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5446 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5447 eb->read_mirror = 0;
5448 atomic_set(&eb->io_pages, num_reads);
5449 for (i = 0; i < num_pages; i++) {
5450 page = eb->pages[i];
5452 if (!PageUptodate(page)) {
5454 atomic_dec(&eb->io_pages);
5459 ClearPageError(page);
5460 err = __extent_read_full_page(tree, page,
5461 btree_get_extent, &bio,
5462 mirror_num, &bio_flags,
5467 * We use &bio in above __extent_read_full_page,
5468 * so we ensure that if it returns error, the
5469 * current page fails to add itself to bio and
5470 * it's been unlocked.
5472 * We must dec io_pages by ourselves.
5474 atomic_dec(&eb->io_pages);
5482 err = submit_one_bio(bio, mirror_num, bio_flags);
5487 if (ret || wait != WAIT_COMPLETE)
5490 for (i = 0; i < num_pages; i++) {
5491 page = eb->pages[i];
5492 wait_on_page_locked(page);
5493 if (!PageUptodate(page))
5500 while (locked_pages > 0) {
5502 page = eb->pages[locked_pages];
5508 void read_extent_buffer(const struct extent_buffer *eb, void *dstv,
5509 unsigned long start, unsigned long len)
5515 char *dst = (char *)dstv;
5516 size_t start_offset = offset_in_page(eb->start);
5517 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5519 if (start + len > eb->len) {
5520 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5521 eb->start, eb->len, start, len);
5522 memset(dst, 0, len);
5526 offset = offset_in_page(start_offset + start);
5529 page = eb->pages[i];
5531 cur = min(len, (PAGE_SIZE - offset));
5532 kaddr = page_address(page);
5533 memcpy(dst, kaddr + offset, cur);
5542 int read_extent_buffer_to_user(const struct extent_buffer *eb,
5544 unsigned long start, unsigned long len)
5550 char __user *dst = (char __user *)dstv;
5551 size_t start_offset = offset_in_page(eb->start);
5552 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5555 WARN_ON(start > eb->len);
5556 WARN_ON(start + len > eb->start + eb->len);
5558 offset = offset_in_page(start_offset + start);
5561 page = eb->pages[i];
5563 cur = min(len, (PAGE_SIZE - offset));
5564 kaddr = page_address(page);
5565 if (copy_to_user(dst, kaddr + offset, cur)) {
5580 * return 0 if the item is found within a page.
5581 * return 1 if the item spans two pages.
5582 * return -EINVAL otherwise.
5584 int map_private_extent_buffer(const struct extent_buffer *eb,
5585 unsigned long start, unsigned long min_len,
5586 char **map, unsigned long *map_start,
5587 unsigned long *map_len)
5592 size_t start_offset = offset_in_page(eb->start);
5593 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5594 unsigned long end_i = (start_offset + start + min_len - 1) >>
5597 if (start + min_len > eb->len) {
5598 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5599 eb->start, eb->len, start, min_len);
5607 offset = start_offset;
5611 *map_start = ((u64)i << PAGE_SHIFT) - start_offset;
5615 kaddr = page_address(p);
5616 *map = kaddr + offset;
5617 *map_len = PAGE_SIZE - offset;
5621 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
5622 unsigned long start, unsigned long len)
5628 char *ptr = (char *)ptrv;
5629 size_t start_offset = offset_in_page(eb->start);
5630 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5633 WARN_ON(start > eb->len);
5634 WARN_ON(start + len > eb->start + eb->len);
5636 offset = offset_in_page(start_offset + start);
5639 page = eb->pages[i];
5641 cur = min(len, (PAGE_SIZE - offset));
5643 kaddr = page_address(page);
5644 ret = memcmp(ptr, kaddr + offset, cur);
5656 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
5661 WARN_ON(!PageUptodate(eb->pages[0]));
5662 kaddr = page_address(eb->pages[0]);
5663 memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
5667 void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)
5671 WARN_ON(!PageUptodate(eb->pages[0]));
5672 kaddr = page_address(eb->pages[0]);
5673 memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
5677 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
5678 unsigned long start, unsigned long len)
5684 char *src = (char *)srcv;
5685 size_t start_offset = offset_in_page(eb->start);
5686 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5688 WARN_ON(start > eb->len);
5689 WARN_ON(start + len > eb->start + eb->len);
5691 offset = offset_in_page(start_offset + start);
5694 page = eb->pages[i];
5695 WARN_ON(!PageUptodate(page));
5697 cur = min(len, PAGE_SIZE - offset);
5698 kaddr = page_address(page);
5699 memcpy(kaddr + offset, src, cur);
5708 void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
5715 size_t start_offset = offset_in_page(eb->start);
5716 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5718 WARN_ON(start > eb->len);
5719 WARN_ON(start + len > eb->start + eb->len);
5721 offset = offset_in_page(start_offset + start);
5724 page = eb->pages[i];
5725 WARN_ON(!PageUptodate(page));
5727 cur = min(len, PAGE_SIZE - offset);
5728 kaddr = page_address(page);
5729 memset(kaddr + offset, 0, cur);
5737 void copy_extent_buffer_full(struct extent_buffer *dst,
5738 struct extent_buffer *src)
5743 ASSERT(dst->len == src->len);
5745 num_pages = num_extent_pages(dst);
5746 for (i = 0; i < num_pages; i++)
5747 copy_page(page_address(dst->pages[i]),
5748 page_address(src->pages[i]));
5751 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5752 unsigned long dst_offset, unsigned long src_offset,
5755 u64 dst_len = dst->len;
5760 size_t start_offset = offset_in_page(dst->start);
5761 unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
5763 WARN_ON(src->len != dst_len);
5765 offset = offset_in_page(start_offset + dst_offset);
5768 page = dst->pages[i];
5769 WARN_ON(!PageUptodate(page));
5771 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5773 kaddr = page_address(page);
5774 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5784 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5786 * @eb: the extent buffer
5787 * @start: offset of the bitmap item in the extent buffer
5789 * @page_index: return index of the page in the extent buffer that contains the
5791 * @page_offset: return offset into the page given by page_index
5793 * This helper hides the ugliness of finding the byte in an extent buffer which
5794 * contains a given bit.
5796 static inline void eb_bitmap_offset(struct extent_buffer *eb,
5797 unsigned long start, unsigned long nr,
5798 unsigned long *page_index,
5799 size_t *page_offset)
5801 size_t start_offset = offset_in_page(eb->start);
5802 size_t byte_offset = BIT_BYTE(nr);
5806 * The byte we want is the offset of the extent buffer + the offset of
5807 * the bitmap item in the extent buffer + the offset of the byte in the
5810 offset = start_offset + start + byte_offset;
5812 *page_index = offset >> PAGE_SHIFT;
5813 *page_offset = offset_in_page(offset);
5817 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5818 * @eb: the extent buffer
5819 * @start: offset of the bitmap item in the extent buffer
5820 * @nr: bit number to test
5822 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
5830 eb_bitmap_offset(eb, start, nr, &i, &offset);
5831 page = eb->pages[i];
5832 WARN_ON(!PageUptodate(page));
5833 kaddr = page_address(page);
5834 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5838 * extent_buffer_bitmap_set - set an area of a bitmap
5839 * @eb: the extent buffer
5840 * @start: offset of the bitmap item in the extent buffer
5841 * @pos: bit number of the first bit
5842 * @len: number of bits to set
5844 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
5845 unsigned long pos, unsigned long len)
5851 const unsigned int size = pos + len;
5852 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5853 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5855 eb_bitmap_offset(eb, start, pos, &i, &offset);
5856 page = eb->pages[i];
5857 WARN_ON(!PageUptodate(page));
5858 kaddr = page_address(page);
5860 while (len >= bits_to_set) {
5861 kaddr[offset] |= mask_to_set;
5863 bits_to_set = BITS_PER_BYTE;
5865 if (++offset >= PAGE_SIZE && len > 0) {
5867 page = eb->pages[++i];
5868 WARN_ON(!PageUptodate(page));
5869 kaddr = page_address(page);
5873 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5874 kaddr[offset] |= mask_to_set;
5880 * extent_buffer_bitmap_clear - clear an area of a bitmap
5881 * @eb: the extent buffer
5882 * @start: offset of the bitmap item in the extent buffer
5883 * @pos: bit number of the first bit
5884 * @len: number of bits to clear
5886 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
5887 unsigned long pos, unsigned long len)
5893 const unsigned int size = pos + len;
5894 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5895 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5897 eb_bitmap_offset(eb, start, pos, &i, &offset);
5898 page = eb->pages[i];
5899 WARN_ON(!PageUptodate(page));
5900 kaddr = page_address(page);
5902 while (len >= bits_to_clear) {
5903 kaddr[offset] &= ~mask_to_clear;
5904 len -= bits_to_clear;
5905 bits_to_clear = BITS_PER_BYTE;
5907 if (++offset >= PAGE_SIZE && len > 0) {
5909 page = eb->pages[++i];
5910 WARN_ON(!PageUptodate(page));
5911 kaddr = page_address(page);
5915 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5916 kaddr[offset] &= ~mask_to_clear;
5920 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5922 unsigned long distance = (src > dst) ? src - dst : dst - src;
5923 return distance < len;
5926 static void copy_pages(struct page *dst_page, struct page *src_page,
5927 unsigned long dst_off, unsigned long src_off,
5930 char *dst_kaddr = page_address(dst_page);
5932 int must_memmove = 0;
5934 if (dst_page != src_page) {
5935 src_kaddr = page_address(src_page);
5937 src_kaddr = dst_kaddr;
5938 if (areas_overlap(src_off, dst_off, len))
5943 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5945 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5948 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5949 unsigned long src_offset, unsigned long len)
5951 struct btrfs_fs_info *fs_info = dst->fs_info;
5953 size_t dst_off_in_page;
5954 size_t src_off_in_page;
5955 size_t start_offset = offset_in_page(dst->start);
5956 unsigned long dst_i;
5957 unsigned long src_i;
5959 if (src_offset + len > dst->len) {
5961 "memmove bogus src_offset %lu move len %lu dst len %lu",
5962 src_offset, len, dst->len);
5965 if (dst_offset + len > dst->len) {
5967 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5968 dst_offset, len, dst->len);
5973 dst_off_in_page = offset_in_page(start_offset + dst_offset);
5974 src_off_in_page = offset_in_page(start_offset + src_offset);
5976 dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
5977 src_i = (start_offset + src_offset) >> PAGE_SHIFT;
5979 cur = min(len, (unsigned long)(PAGE_SIZE -
5981 cur = min_t(unsigned long, cur,
5982 (unsigned long)(PAGE_SIZE - dst_off_in_page));
5984 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5985 dst_off_in_page, src_off_in_page, cur);
5993 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5994 unsigned long src_offset, unsigned long len)
5996 struct btrfs_fs_info *fs_info = dst->fs_info;
5998 size_t dst_off_in_page;
5999 size_t src_off_in_page;
6000 unsigned long dst_end = dst_offset + len - 1;
6001 unsigned long src_end = src_offset + len - 1;
6002 size_t start_offset = offset_in_page(dst->start);
6003 unsigned long dst_i;
6004 unsigned long src_i;
6006 if (src_offset + len > dst->len) {
6008 "memmove bogus src_offset %lu move len %lu len %lu",
6009 src_offset, len, dst->len);
6012 if (dst_offset + len > dst->len) {
6014 "memmove bogus dst_offset %lu move len %lu len %lu",
6015 dst_offset, len, dst->len);
6018 if (dst_offset < src_offset) {
6019 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
6023 dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
6024 src_i = (start_offset + src_end) >> PAGE_SHIFT;
6026 dst_off_in_page = offset_in_page(start_offset + dst_end);
6027 src_off_in_page = offset_in_page(start_offset + src_end);
6029 cur = min_t(unsigned long, len, src_off_in_page + 1);
6030 cur = min(cur, dst_off_in_page + 1);
6031 copy_pages(dst->pages[dst_i], dst->pages[src_i],
6032 dst_off_in_page - cur + 1,
6033 src_off_in_page - cur + 1, cur);
6041 int try_release_extent_buffer(struct page *page)
6043 struct extent_buffer *eb;
6046 * We need to make sure nobody is attaching this page to an eb right
6049 spin_lock(&page->mapping->private_lock);
6050 if (!PagePrivate(page)) {
6051 spin_unlock(&page->mapping->private_lock);
6055 eb = (struct extent_buffer *)page->private;
6059 * This is a little awful but should be ok, we need to make sure that
6060 * the eb doesn't disappear out from under us while we're looking at
6063 spin_lock(&eb->refs_lock);
6064 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
6065 spin_unlock(&eb->refs_lock);
6066 spin_unlock(&page->mapping->private_lock);
6069 spin_unlock(&page->mapping->private_lock);
6072 * If tree ref isn't set then we know the ref on this eb is a real ref,
6073 * so just return, this page will likely be freed soon anyway.
6075 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
6076 spin_unlock(&eb->refs_lock);
6080 return release_extent_buffer(eb);