1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/spinlock.h>
8 #include <linux/blkdev.h>
9 #include <linux/swap.h>
10 #include <linux/writeback.h>
11 #include <linux/pagevec.h>
12 #include <linux/prefetch.h>
13 #include <linux/cleancache.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
17 #include "btrfs_inode.h"
19 #include "check-integrity.h"
21 #include "rcu-string.h"
23 #include "transaction.h"
25 static struct kmem_cache *extent_state_cache;
26 static struct kmem_cache *extent_buffer_cache;
27 static struct bio_set *btrfs_bioset;
29 static inline bool extent_state_in_tree(const struct extent_state *state)
31 return !RB_EMPTY_NODE(&state->rb_node);
34 #ifdef CONFIG_BTRFS_DEBUG
35 static LIST_HEAD(buffers);
36 static LIST_HEAD(states);
38 static DEFINE_SPINLOCK(leak_lock);
41 void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
45 spin_lock_irqsave(&leak_lock, flags);
47 spin_unlock_irqrestore(&leak_lock, flags);
51 void btrfs_leak_debug_del(struct list_head *entry)
55 spin_lock_irqsave(&leak_lock, flags);
57 spin_unlock_irqrestore(&leak_lock, flags);
61 void btrfs_leak_debug_check(void)
63 struct extent_state *state;
64 struct extent_buffer *eb;
66 while (!list_empty(&states)) {
67 state = list_entry(states.next, struct extent_state, leak_list);
68 pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
69 state->start, state->end, state->state,
70 extent_state_in_tree(state),
71 atomic_read(&state->refs));
72 list_del(&state->leak_list);
73 kmem_cache_free(extent_state_cache, state);
76 while (!list_empty(&buffers)) {
77 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
78 pr_err("BTRFS: buffer leak start %llu len %lu refs %d\n",
79 eb->start, eb->len, atomic_read(&eb->refs));
80 list_del(&eb->leak_list);
81 kmem_cache_free(extent_buffer_cache, eb);
85 #define btrfs_debug_check_extent_io_range(tree, start, end) \
86 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
87 static inline void __btrfs_debug_check_extent_io_range(const char *caller,
88 struct extent_io_tree *tree, u64 start, u64 end)
96 inode = tree->mapping->host;
97 isize = i_size_read(inode);
98 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
99 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
100 "%s: ino %llu isize %llu odd range [%llu,%llu]",
101 caller, btrfs_ino(inode), isize, start, end);
105 #define btrfs_leak_debug_add(new, head) do {} while (0)
106 #define btrfs_leak_debug_del(entry) do {} while (0)
107 #define btrfs_leak_debug_check() do {} while (0)
108 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
111 #define BUFFER_LRU_MAX 64
116 struct rb_node rb_node;
119 struct extent_page_data {
121 struct extent_io_tree *tree;
122 get_extent_t *get_extent;
123 unsigned long bio_flags;
125 /* tells writepage not to lock the state bits for this range
126 * it still does the unlocking
128 unsigned int extent_locked:1;
130 /* tells the submit_bio code to use REQ_SYNC */
131 unsigned int sync_io:1;
134 static void add_extent_changeset(struct extent_state *state, unsigned bits,
135 struct extent_changeset *changeset,
142 if (set && (state->state & bits) == bits)
144 if (!set && (state->state & bits) == 0)
146 changeset->bytes_changed += state->end - state->start + 1;
147 ret = ulist_add(changeset->range_changed, state->start, state->end,
153 static noinline void flush_write_bio(void *data);
154 static inline struct btrfs_fs_info *
155 tree_fs_info(struct extent_io_tree *tree)
159 return btrfs_sb(tree->mapping->host->i_sb);
162 int __init extent_io_init(void)
164 extent_state_cache = kmem_cache_create("btrfs_extent_state",
165 sizeof(struct extent_state), 0,
166 SLAB_MEM_SPREAD, NULL);
167 if (!extent_state_cache)
170 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
171 sizeof(struct extent_buffer), 0,
172 SLAB_MEM_SPREAD, NULL);
173 if (!extent_buffer_cache)
174 goto free_state_cache;
176 btrfs_bioset = bioset_create(BIO_POOL_SIZE,
177 offsetof(struct btrfs_io_bio, bio));
179 goto free_buffer_cache;
181 if (bioset_integrity_create(btrfs_bioset, BIO_POOL_SIZE))
187 bioset_free(btrfs_bioset);
191 kmem_cache_destroy(extent_buffer_cache);
192 extent_buffer_cache = NULL;
195 kmem_cache_destroy(extent_state_cache);
196 extent_state_cache = NULL;
200 void extent_io_exit(void)
202 btrfs_leak_debug_check();
205 * Make sure all delayed rcu free are flushed before we
209 kmem_cache_destroy(extent_state_cache);
210 kmem_cache_destroy(extent_buffer_cache);
212 bioset_free(btrfs_bioset);
215 void extent_io_tree_init(struct extent_io_tree *tree,
216 struct address_space *mapping)
218 tree->state = RB_ROOT;
220 tree->dirty_bytes = 0;
221 spin_lock_init(&tree->lock);
222 tree->mapping = mapping;
225 static struct extent_state *alloc_extent_state(gfp_t mask)
227 struct extent_state *state;
230 * The given mask might be not appropriate for the slab allocator,
231 * drop the unsupported bits
233 mask &= ~(__GFP_DMA32|__GFP_HIGHMEM);
234 state = kmem_cache_alloc(extent_state_cache, mask);
238 state->failrec = NULL;
239 RB_CLEAR_NODE(&state->rb_node);
240 btrfs_leak_debug_add(&state->leak_list, &states);
241 atomic_set(&state->refs, 1);
242 init_waitqueue_head(&state->wq);
243 trace_alloc_extent_state(state, mask, _RET_IP_);
247 void free_extent_state(struct extent_state *state)
251 if (atomic_dec_and_test(&state->refs)) {
252 WARN_ON(extent_state_in_tree(state));
253 btrfs_leak_debug_del(&state->leak_list);
254 trace_free_extent_state(state, _RET_IP_);
255 kmem_cache_free(extent_state_cache, state);
259 static struct rb_node *tree_insert(struct rb_root *root,
260 struct rb_node *search_start,
262 struct rb_node *node,
263 struct rb_node ***p_in,
264 struct rb_node **parent_in)
267 struct rb_node *parent = NULL;
268 struct tree_entry *entry;
270 if (p_in && parent_in) {
276 p = search_start ? &search_start : &root->rb_node;
279 entry = rb_entry(parent, struct tree_entry, rb_node);
281 if (offset < entry->start)
283 else if (offset > entry->end)
290 rb_link_node(node, parent, p);
291 rb_insert_color(node, root);
295 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
296 struct rb_node **prev_ret,
297 struct rb_node **next_ret,
298 struct rb_node ***p_ret,
299 struct rb_node **parent_ret)
301 struct rb_root *root = &tree->state;
302 struct rb_node **n = &root->rb_node;
303 struct rb_node *prev = NULL;
304 struct rb_node *orig_prev = NULL;
305 struct tree_entry *entry;
306 struct tree_entry *prev_entry = NULL;
310 entry = rb_entry(prev, struct tree_entry, rb_node);
313 if (offset < entry->start)
315 else if (offset > entry->end)
328 while (prev && offset > prev_entry->end) {
329 prev = rb_next(prev);
330 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
337 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
338 while (prev && offset < prev_entry->start) {
339 prev = rb_prev(prev);
340 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
347 static inline struct rb_node *
348 tree_search_for_insert(struct extent_io_tree *tree,
350 struct rb_node ***p_ret,
351 struct rb_node **parent_ret)
353 struct rb_node *prev = NULL;
356 ret = __etree_search(tree, offset, &prev, NULL, p_ret, parent_ret);
362 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
365 return tree_search_for_insert(tree, offset, NULL, NULL);
368 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
369 struct extent_state *other)
371 if (tree->ops && tree->ops->merge_extent_hook)
372 tree->ops->merge_extent_hook(tree->mapping->host, new,
377 * utility function to look for merge candidates inside a given range.
378 * Any extents with matching state are merged together into a single
379 * extent in the tree. Extents with EXTENT_IO in their state field
380 * are not merged because the end_io handlers need to be able to do
381 * operations on them without sleeping (or doing allocations/splits).
383 * This should be called with the tree lock held.
385 static void merge_state(struct extent_io_tree *tree,
386 struct extent_state *state)
388 struct extent_state *other;
389 struct rb_node *other_node;
391 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
394 other_node = rb_prev(&state->rb_node);
396 other = rb_entry(other_node, struct extent_state, rb_node);
397 if (other->end == state->start - 1 &&
398 other->state == state->state) {
399 merge_cb(tree, state, other);
400 state->start = other->start;
401 rb_erase(&other->rb_node, &tree->state);
402 RB_CLEAR_NODE(&other->rb_node);
403 free_extent_state(other);
406 other_node = rb_next(&state->rb_node);
408 other = rb_entry(other_node, struct extent_state, rb_node);
409 if (other->start == state->end + 1 &&
410 other->state == state->state) {
411 merge_cb(tree, state, other);
412 state->end = other->end;
413 rb_erase(&other->rb_node, &tree->state);
414 RB_CLEAR_NODE(&other->rb_node);
415 free_extent_state(other);
420 static void set_state_cb(struct extent_io_tree *tree,
421 struct extent_state *state, unsigned *bits)
423 if (tree->ops && tree->ops->set_bit_hook)
424 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
427 static void clear_state_cb(struct extent_io_tree *tree,
428 struct extent_state *state, unsigned *bits)
430 if (tree->ops && tree->ops->clear_bit_hook)
431 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
434 static void set_state_bits(struct extent_io_tree *tree,
435 struct extent_state *state, unsigned *bits,
436 struct extent_changeset *changeset);
439 * insert an extent_state struct into the tree. 'bits' are set on the
440 * struct before it is inserted.
442 * This may return -EEXIST if the extent is already there, in which case the
443 * state struct is freed.
445 * The tree lock is not taken internally. This is a utility function and
446 * probably isn't what you want to call (see set/clear_extent_bit).
448 static int insert_state(struct extent_io_tree *tree,
449 struct extent_state *state, u64 start, u64 end,
451 struct rb_node **parent,
452 unsigned *bits, struct extent_changeset *changeset)
454 struct rb_node *node;
457 WARN(1, KERN_ERR "BTRFS: end < start %llu %llu\n",
459 state->start = start;
462 set_state_bits(tree, state, bits, changeset);
464 node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
466 struct extent_state *found;
467 found = rb_entry(node, struct extent_state, rb_node);
468 pr_err("BTRFS: found node %llu %llu on insert of %llu %llu\n",
469 found->start, found->end, start, end);
472 merge_state(tree, state);
476 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
479 if (tree->ops && tree->ops->split_extent_hook)
480 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
484 * split a given extent state struct in two, inserting the preallocated
485 * struct 'prealloc' as the newly created second half. 'split' indicates an
486 * offset inside 'orig' where it should be split.
489 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
490 * are two extent state structs in the tree:
491 * prealloc: [orig->start, split - 1]
492 * orig: [ split, orig->end ]
494 * The tree locks are not taken by this function. They need to be held
497 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
498 struct extent_state *prealloc, u64 split)
500 struct rb_node *node;
502 split_cb(tree, orig, split);
504 prealloc->start = orig->start;
505 prealloc->end = split - 1;
506 prealloc->state = orig->state;
509 node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
510 &prealloc->rb_node, NULL, NULL);
512 free_extent_state(prealloc);
518 static struct extent_state *next_state(struct extent_state *state)
520 struct rb_node *next = rb_next(&state->rb_node);
522 return rb_entry(next, struct extent_state, rb_node);
528 * utility function to clear some bits in an extent state struct.
529 * it will optionally wake up any one waiting on this state (wake == 1).
531 * If no bits are set on the state struct after clearing things, the
532 * struct is freed and removed from the tree
534 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
535 struct extent_state *state,
536 unsigned *bits, int wake,
537 struct extent_changeset *changeset)
539 struct extent_state *next;
540 unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
542 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
543 u64 range = state->end - state->start + 1;
544 WARN_ON(range > tree->dirty_bytes);
545 tree->dirty_bytes -= range;
547 clear_state_cb(tree, state, bits);
548 add_extent_changeset(state, bits_to_clear, changeset, 0);
549 state->state &= ~bits_to_clear;
552 if (state->state == 0) {
553 next = next_state(state);
554 if (extent_state_in_tree(state)) {
555 rb_erase(&state->rb_node, &tree->state);
556 RB_CLEAR_NODE(&state->rb_node);
557 free_extent_state(state);
562 merge_state(tree, state);
563 next = next_state(state);
568 static struct extent_state *
569 alloc_extent_state_atomic(struct extent_state *prealloc)
572 prealloc = alloc_extent_state(GFP_ATOMIC);
577 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
579 btrfs_panic(tree_fs_info(tree), err,
580 "Locking error: Extent tree was modified by another thread while locked.");
584 * clear some bits on a range in the tree. This may require splitting
585 * or inserting elements in the tree, so the gfp mask is used to
586 * indicate which allocations or sleeping are allowed.
588 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
589 * the given range from the tree regardless of state (ie for truncate).
591 * the range [start, end] is inclusive.
593 * This takes the tree lock, and returns 0 on success and < 0 on error.
595 static int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
596 unsigned bits, int wake, int delete,
597 struct extent_state **cached_state,
598 gfp_t mask, struct extent_changeset *changeset)
600 struct extent_state *state;
601 struct extent_state *cached;
602 struct extent_state *prealloc = NULL;
603 struct rb_node *node;
608 btrfs_debug_check_extent_io_range(tree, start, end);
610 if (bits & EXTENT_DELALLOC)
611 bits |= EXTENT_NORESERVE;
614 bits |= ~EXTENT_CTLBITS;
615 bits |= EXTENT_FIRST_DELALLOC;
617 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
620 if (!prealloc && gfpflags_allow_blocking(mask)) {
622 * Don't care for allocation failure here because we might end
623 * up not needing the pre-allocated extent state at all, which
624 * is the case if we only have in the tree extent states that
625 * cover our input range and don't cover too any other range.
626 * If we end up needing a new extent state we allocate it later.
628 prealloc = alloc_extent_state(mask);
631 spin_lock(&tree->lock);
633 cached = *cached_state;
636 *cached_state = NULL;
640 if (cached && extent_state_in_tree(cached) &&
641 cached->start <= start && cached->end > start) {
643 atomic_dec(&cached->refs);
648 free_extent_state(cached);
651 * this search will find the extents that end after
654 node = tree_search(tree, start);
657 state = rb_entry(node, struct extent_state, rb_node);
659 if (state->start > end)
661 WARN_ON(state->end < start);
662 last_end = state->end;
664 /* the state doesn't have the wanted bits, go ahead */
665 if (!(state->state & bits)) {
666 state = next_state(state);
671 * | ---- desired range ---- |
673 * | ------------- state -------------- |
675 * We need to split the extent we found, and may flip
676 * bits on second half.
678 * If the extent we found extends past our range, we
679 * just split and search again. It'll get split again
680 * the next time though.
682 * If the extent we found is inside our range, we clear
683 * the desired bit on it.
686 if (state->start < start) {
687 prealloc = alloc_extent_state_atomic(prealloc);
689 err = split_state(tree, state, prealloc, start);
691 extent_io_tree_panic(tree, err);
696 if (state->end <= end) {
697 state = clear_state_bit(tree, state, &bits, wake,
704 * | ---- desired range ---- |
706 * We need to split the extent, and clear the bit
709 if (state->start <= end && state->end > end) {
710 prealloc = alloc_extent_state_atomic(prealloc);
712 err = split_state(tree, state, prealloc, end + 1);
714 extent_io_tree_panic(tree, err);
719 clear_state_bit(tree, prealloc, &bits, wake, changeset);
725 state = clear_state_bit(tree, state, &bits, wake, changeset);
727 if (last_end == (u64)-1)
729 start = last_end + 1;
730 if (start <= end && state && !need_resched())
736 spin_unlock(&tree->lock);
737 if (gfpflags_allow_blocking(mask))
742 spin_unlock(&tree->lock);
744 free_extent_state(prealloc);
750 static void wait_on_state(struct extent_io_tree *tree,
751 struct extent_state *state)
752 __releases(tree->lock)
753 __acquires(tree->lock)
756 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
757 spin_unlock(&tree->lock);
759 spin_lock(&tree->lock);
760 finish_wait(&state->wq, &wait);
764 * waits for one or more bits to clear on a range in the state tree.
765 * The range [start, end] is inclusive.
766 * The tree lock is taken by this function
768 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
771 struct extent_state *state;
772 struct rb_node *node;
774 btrfs_debug_check_extent_io_range(tree, start, end);
776 spin_lock(&tree->lock);
780 * this search will find all the extents that end after
783 node = tree_search(tree, start);
788 state = rb_entry(node, struct extent_state, rb_node);
790 if (state->start > end)
793 if (state->state & bits) {
794 start = state->start;
795 atomic_inc(&state->refs);
796 wait_on_state(tree, state);
797 free_extent_state(state);
800 start = state->end + 1;
805 if (!cond_resched_lock(&tree->lock)) {
806 node = rb_next(node);
811 spin_unlock(&tree->lock);
814 static void set_state_bits(struct extent_io_tree *tree,
815 struct extent_state *state,
816 unsigned *bits, struct extent_changeset *changeset)
818 unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
820 set_state_cb(tree, state, bits);
821 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
822 u64 range = state->end - state->start + 1;
823 tree->dirty_bytes += range;
825 add_extent_changeset(state, bits_to_set, changeset, 1);
826 state->state |= bits_to_set;
829 static void cache_state_if_flags(struct extent_state *state,
830 struct extent_state **cached_ptr,
833 if (cached_ptr && !(*cached_ptr)) {
834 if (!flags || (state->state & flags)) {
836 atomic_inc(&state->refs);
841 static void cache_state(struct extent_state *state,
842 struct extent_state **cached_ptr)
844 return cache_state_if_flags(state, cached_ptr,
845 EXTENT_IOBITS | EXTENT_BOUNDARY);
849 * set some bits on a range in the tree. This may require allocations or
850 * sleeping, so the gfp mask is used to indicate what is allowed.
852 * If any of the exclusive bits are set, this will fail with -EEXIST if some
853 * part of the range already has the desired bits set. The start of the
854 * existing range is returned in failed_start in this case.
856 * [start, end] is inclusive This takes the tree lock.
859 static int __must_check
860 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
861 unsigned bits, unsigned exclusive_bits,
862 u64 *failed_start, struct extent_state **cached_state,
863 gfp_t mask, struct extent_changeset *changeset)
865 struct extent_state *state;
866 struct extent_state *prealloc = NULL;
867 struct rb_node *node;
869 struct rb_node *parent;
874 btrfs_debug_check_extent_io_range(tree, start, end);
876 bits |= EXTENT_FIRST_DELALLOC;
878 if (!prealloc && gfpflags_allow_blocking(mask)) {
880 * Don't care for allocation failure here because we might end
881 * up not needing the pre-allocated extent state at all, which
882 * is the case if we only have in the tree extent states that
883 * cover our input range and don't cover too any other range.
884 * If we end up needing a new extent state we allocate it later.
886 prealloc = alloc_extent_state(mask);
889 spin_lock(&tree->lock);
890 if (cached_state && *cached_state) {
891 state = *cached_state;
892 if (state->start <= start && state->end > start &&
893 extent_state_in_tree(state)) {
894 node = &state->rb_node;
899 * this search will find all the extents that end after
902 node = tree_search_for_insert(tree, start, &p, &parent);
904 prealloc = alloc_extent_state_atomic(prealloc);
906 err = insert_state(tree, prealloc, start, end,
907 &p, &parent, &bits, changeset);
909 extent_io_tree_panic(tree, err);
911 cache_state(prealloc, cached_state);
915 state = rb_entry(node, struct extent_state, rb_node);
917 last_start = state->start;
918 last_end = state->end;
921 * | ---- desired range ---- |
924 * Just lock what we found and keep going
926 if (state->start == start && state->end <= end) {
927 if (state->state & exclusive_bits) {
928 *failed_start = state->start;
933 set_state_bits(tree, state, &bits, changeset);
934 cache_state(state, cached_state);
935 merge_state(tree, state);
936 if (last_end == (u64)-1)
938 start = last_end + 1;
939 state = next_state(state);
940 if (start < end && state && state->start == start &&
947 * | ---- desired range ---- |
950 * | ------------- state -------------- |
952 * We need to split the extent we found, and may flip bits on
955 * If the extent we found extends past our
956 * range, we just split and search again. It'll get split
957 * again the next time though.
959 * If the extent we found is inside our range, we set the
962 if (state->start < start) {
963 if (state->state & exclusive_bits) {
964 *failed_start = start;
969 prealloc = alloc_extent_state_atomic(prealloc);
971 err = split_state(tree, state, prealloc, start);
973 extent_io_tree_panic(tree, err);
978 if (state->end <= end) {
979 set_state_bits(tree, state, &bits, changeset);
980 cache_state(state, cached_state);
981 merge_state(tree, state);
982 if (last_end == (u64)-1)
984 start = last_end + 1;
985 state = next_state(state);
986 if (start < end && state && state->start == start &&
993 * | ---- desired range ---- |
994 * | state | or | state |
996 * There's a hole, we need to insert something in it and
997 * ignore the extent we found.
999 if (state->start > start) {
1001 if (end < last_start)
1004 this_end = last_start - 1;
1006 prealloc = alloc_extent_state_atomic(prealloc);
1010 * Avoid to free 'prealloc' if it can be merged with
1013 err = insert_state(tree, prealloc, start, this_end,
1014 NULL, NULL, &bits, changeset);
1016 extent_io_tree_panic(tree, err);
1018 cache_state(prealloc, cached_state);
1020 start = this_end + 1;
1024 * | ---- desired range ---- |
1026 * We need to split the extent, and set the bit
1029 if (state->start <= end && state->end > end) {
1030 if (state->state & exclusive_bits) {
1031 *failed_start = start;
1036 prealloc = alloc_extent_state_atomic(prealloc);
1038 err = split_state(tree, state, prealloc, end + 1);
1040 extent_io_tree_panic(tree, err);
1042 set_state_bits(tree, prealloc, &bits, changeset);
1043 cache_state(prealloc, cached_state);
1044 merge_state(tree, prealloc);
1052 spin_unlock(&tree->lock);
1053 if (gfpflags_allow_blocking(mask))
1058 spin_unlock(&tree->lock);
1060 free_extent_state(prealloc);
1066 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1067 unsigned bits, u64 * failed_start,
1068 struct extent_state **cached_state, gfp_t mask)
1070 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
1071 cached_state, mask, NULL);
1076 * convert_extent_bit - convert all bits in a given range from one bit to
1078 * @tree: the io tree to search
1079 * @start: the start offset in bytes
1080 * @end: the end offset in bytes (inclusive)
1081 * @bits: the bits to set in this range
1082 * @clear_bits: the bits to clear in this range
1083 * @cached_state: state that we're going to cache
1085 * This will go through and set bits for the given range. If any states exist
1086 * already in this range they are set with the given bit and cleared of the
1087 * clear_bits. This is only meant to be used by things that are mergeable, ie
1088 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1089 * boundary bits like LOCK.
1091 * All allocations are done with GFP_NOFS.
1093 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1094 unsigned bits, unsigned clear_bits,
1095 struct extent_state **cached_state)
1097 struct extent_state *state;
1098 struct extent_state *prealloc = NULL;
1099 struct rb_node *node;
1101 struct rb_node *parent;
1105 bool first_iteration = true;
1107 btrfs_debug_check_extent_io_range(tree, start, end);
1112 * Best effort, don't worry if extent state allocation fails
1113 * here for the first iteration. We might have a cached state
1114 * that matches exactly the target range, in which case no
1115 * extent state allocations are needed. We'll only know this
1116 * after locking the tree.
1118 prealloc = alloc_extent_state(GFP_NOFS);
1119 if (!prealloc && !first_iteration)
1123 spin_lock(&tree->lock);
1124 if (cached_state && *cached_state) {
1125 state = *cached_state;
1126 if (state->start <= start && state->end > start &&
1127 extent_state_in_tree(state)) {
1128 node = &state->rb_node;
1134 * this search will find all the extents that end after
1137 node = tree_search_for_insert(tree, start, &p, &parent);
1139 prealloc = alloc_extent_state_atomic(prealloc);
1144 err = insert_state(tree, prealloc, start, end,
1145 &p, &parent, &bits, NULL);
1147 extent_io_tree_panic(tree, err);
1148 cache_state(prealloc, cached_state);
1152 state = rb_entry(node, struct extent_state, rb_node);
1154 last_start = state->start;
1155 last_end = state->end;
1158 * | ---- desired range ---- |
1161 * Just lock what we found and keep going
1163 if (state->start == start && state->end <= end) {
1164 set_state_bits(tree, state, &bits, NULL);
1165 cache_state(state, cached_state);
1166 state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
1167 if (last_end == (u64)-1)
1169 start = last_end + 1;
1170 if (start < end && state && state->start == start &&
1177 * | ---- desired range ---- |
1180 * | ------------- state -------------- |
1182 * We need to split the extent we found, and may flip bits on
1185 * If the extent we found extends past our
1186 * range, we just split and search again. It'll get split
1187 * again the next time though.
1189 * If the extent we found is inside our range, we set the
1190 * desired bit on it.
1192 if (state->start < start) {
1193 prealloc = alloc_extent_state_atomic(prealloc);
1198 err = split_state(tree, state, prealloc, start);
1200 extent_io_tree_panic(tree, err);
1204 if (state->end <= end) {
1205 set_state_bits(tree, state, &bits, NULL);
1206 cache_state(state, cached_state);
1207 state = clear_state_bit(tree, state, &clear_bits, 0,
1209 if (last_end == (u64)-1)
1211 start = last_end + 1;
1212 if (start < end && state && state->start == start &&
1219 * | ---- desired range ---- |
1220 * | state | or | state |
1222 * There's a hole, we need to insert something in it and
1223 * ignore the extent we found.
1225 if (state->start > start) {
1227 if (end < last_start)
1230 this_end = last_start - 1;
1232 prealloc = alloc_extent_state_atomic(prealloc);
1239 * Avoid to free 'prealloc' if it can be merged with
1242 err = insert_state(tree, prealloc, start, this_end,
1243 NULL, NULL, &bits, NULL);
1245 extent_io_tree_panic(tree, err);
1246 cache_state(prealloc, cached_state);
1248 start = this_end + 1;
1252 * | ---- desired range ---- |
1254 * We need to split the extent, and set the bit
1257 if (state->start <= end && state->end > end) {
1258 prealloc = alloc_extent_state_atomic(prealloc);
1264 err = split_state(tree, state, prealloc, end + 1);
1266 extent_io_tree_panic(tree, err);
1268 set_state_bits(tree, prealloc, &bits, NULL);
1269 cache_state(prealloc, cached_state);
1270 clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
1278 spin_unlock(&tree->lock);
1280 first_iteration = false;
1284 spin_unlock(&tree->lock);
1286 free_extent_state(prealloc);
1291 /* wrappers around set/clear extent bit */
1292 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1293 unsigned bits, struct extent_changeset *changeset)
1296 * We don't support EXTENT_LOCKED yet, as current changeset will
1297 * record any bits changed, so for EXTENT_LOCKED case, it will
1298 * either fail with -EEXIST or changeset will record the whole
1301 BUG_ON(bits & EXTENT_LOCKED);
1303 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
1307 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1308 unsigned bits, int wake, int delete,
1309 struct extent_state **cached, gfp_t mask)
1311 return __clear_extent_bit(tree, start, end, bits, wake, delete,
1312 cached, mask, NULL);
1315 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1316 unsigned bits, struct extent_changeset *changeset)
1319 * Don't support EXTENT_LOCKED case, same reason as
1320 * set_record_extent_bits().
1322 BUG_ON(bits & EXTENT_LOCKED);
1324 return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
1329 * either insert or lock state struct between start and end use mask to tell
1330 * us if waiting is desired.
1332 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1333 struct extent_state **cached_state)
1339 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
1340 EXTENT_LOCKED, &failed_start,
1341 cached_state, GFP_NOFS, NULL);
1342 if (err == -EEXIST) {
1343 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1344 start = failed_start;
1347 WARN_ON(start > end);
1352 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1357 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1358 &failed_start, NULL, GFP_NOFS, NULL);
1359 if (err == -EEXIST) {
1360 if (failed_start > start)
1361 clear_extent_bit(tree, start, failed_start - 1,
1362 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
1368 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1370 unsigned long index = start >> PAGE_SHIFT;
1371 unsigned long end_index = end >> PAGE_SHIFT;
1374 while (index <= end_index) {
1375 page = find_get_page(inode->i_mapping, index);
1376 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1377 clear_page_dirty_for_io(page);
1383 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1385 unsigned long index = start >> PAGE_SHIFT;
1386 unsigned long end_index = end >> PAGE_SHIFT;
1389 while (index <= end_index) {
1390 page = find_get_page(inode->i_mapping, index);
1391 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1392 __set_page_dirty_nobuffers(page);
1393 account_page_redirty(page);
1400 * helper function to set both pages and extents in the tree writeback
1402 static void set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1404 unsigned long index = start >> PAGE_SHIFT;
1405 unsigned long end_index = end >> PAGE_SHIFT;
1408 while (index <= end_index) {
1409 page = find_get_page(tree->mapping, index);
1410 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1411 set_page_writeback(page);
1417 /* find the first state struct with 'bits' set after 'start', and
1418 * return it. tree->lock must be held. NULL will returned if
1419 * nothing was found after 'start'
1421 static struct extent_state *
1422 find_first_extent_bit_state(struct extent_io_tree *tree,
1423 u64 start, unsigned bits)
1425 struct rb_node *node;
1426 struct extent_state *state;
1429 * this search will find all the extents that end after
1432 node = tree_search(tree, start);
1437 state = rb_entry(node, struct extent_state, rb_node);
1438 if (state->end >= start && (state->state & bits))
1441 node = rb_next(node);
1450 * find the first offset in the io tree with 'bits' set. zero is
1451 * returned if we find something, and *start_ret and *end_ret are
1452 * set to reflect the state struct that was found.
1454 * If nothing was found, 1 is returned. If found something, return 0.
1456 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1457 u64 *start_ret, u64 *end_ret, unsigned bits,
1458 struct extent_state **cached_state)
1460 struct extent_state *state;
1464 spin_lock(&tree->lock);
1465 if (cached_state && *cached_state) {
1466 state = *cached_state;
1467 if (state->end == start - 1 && extent_state_in_tree(state)) {
1468 n = rb_next(&state->rb_node);
1470 state = rb_entry(n, struct extent_state,
1472 if (state->state & bits)
1476 free_extent_state(*cached_state);
1477 *cached_state = NULL;
1480 free_extent_state(*cached_state);
1481 *cached_state = NULL;
1484 state = find_first_extent_bit_state(tree, start, bits);
1487 cache_state_if_flags(state, cached_state, 0);
1488 *start_ret = state->start;
1489 *end_ret = state->end;
1493 spin_unlock(&tree->lock);
1498 * find a contiguous range of bytes in the file marked as delalloc, not
1499 * more than 'max_bytes'. start and end are used to return the range,
1501 * 1 is returned if we find something, 0 if nothing was in the tree
1503 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1504 u64 *start, u64 *end, u64 max_bytes,
1505 struct extent_state **cached_state)
1507 struct rb_node *node;
1508 struct extent_state *state;
1509 u64 cur_start = *start;
1511 u64 total_bytes = 0;
1513 spin_lock(&tree->lock);
1516 * this search will find all the extents that end after
1519 node = tree_search(tree, cur_start);
1527 state = rb_entry(node, struct extent_state, rb_node);
1528 if (found && (state->start != cur_start ||
1529 (state->state & EXTENT_BOUNDARY))) {
1532 if (!(state->state & EXTENT_DELALLOC)) {
1538 *start = state->start;
1539 *cached_state = state;
1540 atomic_inc(&state->refs);
1544 cur_start = state->end + 1;
1545 node = rb_next(node);
1546 total_bytes += state->end - state->start + 1;
1547 if (total_bytes >= max_bytes)
1553 spin_unlock(&tree->lock);
1557 static noinline void __unlock_for_delalloc(struct inode *inode,
1558 struct page *locked_page,
1562 struct page *pages[16];
1563 unsigned long index = start >> PAGE_SHIFT;
1564 unsigned long end_index = end >> PAGE_SHIFT;
1565 unsigned long nr_pages = end_index - index + 1;
1568 if (index == locked_page->index && end_index == index)
1571 while (nr_pages > 0) {
1572 ret = find_get_pages_contig(inode->i_mapping, index,
1573 min_t(unsigned long, nr_pages,
1574 ARRAY_SIZE(pages)), pages);
1575 for (i = 0; i < ret; i++) {
1576 if (pages[i] != locked_page)
1577 unlock_page(pages[i]);
1586 static noinline int lock_delalloc_pages(struct inode *inode,
1587 struct page *locked_page,
1591 unsigned long index = delalloc_start >> PAGE_SHIFT;
1592 unsigned long start_index = index;
1593 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1594 unsigned long pages_locked = 0;
1595 struct page *pages[16];
1596 unsigned long nrpages;
1600 /* the caller is responsible for locking the start index */
1601 if (index == locked_page->index && index == end_index)
1604 /* skip the page at the start index */
1605 nrpages = end_index - index + 1;
1606 while (nrpages > 0) {
1607 ret = find_get_pages_contig(inode->i_mapping, index,
1608 min_t(unsigned long,
1609 nrpages, ARRAY_SIZE(pages)), pages);
1614 /* now we have an array of pages, lock them all */
1615 for (i = 0; i < ret; i++) {
1617 * the caller is taking responsibility for
1620 if (pages[i] != locked_page) {
1621 lock_page(pages[i]);
1622 if (!PageDirty(pages[i]) ||
1623 pages[i]->mapping != inode->i_mapping) {
1625 unlock_page(pages[i]);
1639 if (ret && pages_locked) {
1640 __unlock_for_delalloc(inode, locked_page,
1642 ((u64)(start_index + pages_locked - 1)) <<
1649 * find a contiguous range of bytes in the file marked as delalloc, not
1650 * more than 'max_bytes'. start and end are used to return the range,
1652 * 1 is returned if we find something, 0 if nothing was in the tree
1654 STATIC u64 find_lock_delalloc_range(struct inode *inode,
1655 struct extent_io_tree *tree,
1656 struct page *locked_page, u64 *start,
1657 u64 *end, u64 max_bytes)
1662 struct extent_state *cached_state = NULL;
1667 /* step one, find a bunch of delalloc bytes starting at start */
1668 delalloc_start = *start;
1670 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1671 max_bytes, &cached_state);
1672 if (!found || delalloc_end <= *start) {
1673 *start = delalloc_start;
1674 *end = delalloc_end;
1675 free_extent_state(cached_state);
1680 * start comes from the offset of locked_page. We have to lock
1681 * pages in order, so we can't process delalloc bytes before
1684 if (delalloc_start < *start)
1685 delalloc_start = *start;
1688 * make sure to limit the number of pages we try to lock down
1690 if (delalloc_end + 1 - delalloc_start > max_bytes)
1691 delalloc_end = delalloc_start + max_bytes - 1;
1693 /* step two, lock all the pages after the page that has start */
1694 ret = lock_delalloc_pages(inode, locked_page,
1695 delalloc_start, delalloc_end);
1696 if (ret == -EAGAIN) {
1697 /* some of the pages are gone, lets avoid looping by
1698 * shortening the size of the delalloc range we're searching
1700 free_extent_state(cached_state);
1701 cached_state = NULL;
1703 max_bytes = PAGE_SIZE;
1711 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1713 /* step three, lock the state bits for the whole range */
1714 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1716 /* then test to make sure it is all still delalloc */
1717 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1718 EXTENT_DELALLOC, 1, cached_state);
1720 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1721 &cached_state, GFP_NOFS);
1722 __unlock_for_delalloc(inode, locked_page,
1723 delalloc_start, delalloc_end);
1727 free_extent_state(cached_state);
1728 *start = delalloc_start;
1729 *end = delalloc_end;
1734 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1735 u64 delalloc_end, struct page *locked_page,
1736 unsigned clear_bits,
1737 unsigned long page_ops)
1739 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
1741 struct page *pages[16];
1742 unsigned long index = start >> PAGE_SHIFT;
1743 unsigned long end_index = end >> PAGE_SHIFT;
1744 unsigned long nr_pages = end_index - index + 1;
1747 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1751 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1752 mapping_set_error(inode->i_mapping, -EIO);
1754 while (nr_pages > 0) {
1755 ret = find_get_pages_contig(inode->i_mapping, index,
1756 min_t(unsigned long,
1757 nr_pages, ARRAY_SIZE(pages)), pages);
1758 for (i = 0; i < ret; i++) {
1760 if (page_ops & PAGE_SET_PRIVATE2)
1761 SetPagePrivate2(pages[i]);
1763 if (pages[i] == locked_page) {
1767 if (page_ops & PAGE_CLEAR_DIRTY)
1768 clear_page_dirty_for_io(pages[i]);
1769 if (page_ops & PAGE_SET_WRITEBACK)
1770 set_page_writeback(pages[i]);
1771 if (page_ops & PAGE_SET_ERROR)
1772 SetPageError(pages[i]);
1773 if (page_ops & PAGE_END_WRITEBACK)
1774 end_page_writeback(pages[i]);
1775 if (page_ops & PAGE_UNLOCK)
1776 unlock_page(pages[i]);
1786 * count the number of bytes in the tree that have a given bit(s)
1787 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1788 * cached. The total number found is returned.
1790 u64 count_range_bits(struct extent_io_tree *tree,
1791 u64 *start, u64 search_end, u64 max_bytes,
1792 unsigned bits, int contig)
1794 struct rb_node *node;
1795 struct extent_state *state;
1796 u64 cur_start = *start;
1797 u64 total_bytes = 0;
1801 if (WARN_ON(search_end <= cur_start))
1804 spin_lock(&tree->lock);
1805 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1806 total_bytes = tree->dirty_bytes;
1810 * this search will find all the extents that end after
1813 node = tree_search(tree, cur_start);
1818 state = rb_entry(node, struct extent_state, rb_node);
1819 if (state->start > search_end)
1821 if (contig && found && state->start > last + 1)
1823 if (state->end >= cur_start && (state->state & bits) == bits) {
1824 total_bytes += min(search_end, state->end) + 1 -
1825 max(cur_start, state->start);
1826 if (total_bytes >= max_bytes)
1829 *start = max(cur_start, state->start);
1833 } else if (contig && found) {
1836 node = rb_next(node);
1841 spin_unlock(&tree->lock);
1846 * set the private field for a given byte offset in the tree. If there isn't
1847 * an extent_state there already, this does nothing.
1849 static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start,
1850 struct io_failure_record *failrec)
1852 struct rb_node *node;
1853 struct extent_state *state;
1856 spin_lock(&tree->lock);
1858 * this search will find all the extents that end after
1861 node = tree_search(tree, start);
1866 state = rb_entry(node, struct extent_state, rb_node);
1867 if (state->start != start) {
1871 state->failrec = failrec;
1873 spin_unlock(&tree->lock);
1877 static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start,
1878 struct io_failure_record **failrec)
1880 struct rb_node *node;
1881 struct extent_state *state;
1884 spin_lock(&tree->lock);
1886 * this search will find all the extents that end after
1889 node = tree_search(tree, start);
1894 state = rb_entry(node, struct extent_state, rb_node);
1895 if (state->start != start) {
1899 *failrec = state->failrec;
1901 spin_unlock(&tree->lock);
1906 * searches a range in the state tree for a given mask.
1907 * If 'filled' == 1, this returns 1 only if every extent in the tree
1908 * has the bits set. Otherwise, 1 is returned if any bit in the
1909 * range is found set.
1911 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1912 unsigned bits, int filled, struct extent_state *cached)
1914 struct extent_state *state = NULL;
1915 struct rb_node *node;
1918 spin_lock(&tree->lock);
1919 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
1920 cached->end > start)
1921 node = &cached->rb_node;
1923 node = tree_search(tree, start);
1924 while (node && start <= end) {
1925 state = rb_entry(node, struct extent_state, rb_node);
1927 if (filled && state->start > start) {
1932 if (state->start > end)
1935 if (state->state & bits) {
1939 } else if (filled) {
1944 if (state->end == (u64)-1)
1947 start = state->end + 1;
1950 node = rb_next(node);
1957 spin_unlock(&tree->lock);
1962 * helper function to set a given page up to date if all the
1963 * extents in the tree for that page are up to date
1965 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1967 u64 start = page_offset(page);
1968 u64 end = start + PAGE_SIZE - 1;
1969 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1970 SetPageUptodate(page);
1973 int free_io_failure(struct inode *inode, struct io_failure_record *rec)
1977 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1979 set_state_failrec(failure_tree, rec->start, NULL);
1980 ret = clear_extent_bits(failure_tree, rec->start,
1981 rec->start + rec->len - 1,
1982 EXTENT_LOCKED | EXTENT_DIRTY);
1986 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1987 rec->start + rec->len - 1,
1997 * this bypasses the standard btrfs submit functions deliberately, as
1998 * the standard behavior is to write all copies in a raid setup. here we only
1999 * want to write the one bad copy. so we do the mapping for ourselves and issue
2000 * submit_bio directly.
2001 * to avoid any synchronization issues, wait for the data after writing, which
2002 * actually prevents the read that triggered the error from finishing.
2003 * currently, there can be no more than two copies of every data bit. thus,
2004 * exactly one rewrite is required.
2006 int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical,
2007 struct page *page, unsigned int pg_offset, int mirror_num)
2009 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2011 struct btrfs_device *dev;
2014 struct btrfs_bio *bbio = NULL;
2015 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
2018 ASSERT(!(fs_info->sb->s_flags & MS_RDONLY));
2019 BUG_ON(!mirror_num);
2021 /* we can't repair anything in raid56 yet */
2022 if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num))
2025 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2028 bio->bi_iter.bi_size = 0;
2029 map_length = length;
2032 * Avoid races with device replace and make sure our bbio has devices
2033 * associated to its stripes that don't go away while we are doing the
2034 * read repair operation.
2036 btrfs_bio_counter_inc_blocked(fs_info);
2037 ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
2038 &map_length, &bbio, mirror_num);
2040 btrfs_bio_counter_dec(fs_info);
2044 BUG_ON(mirror_num != bbio->mirror_num);
2045 sector = bbio->stripes[mirror_num-1].physical >> 9;
2046 bio->bi_iter.bi_sector = sector;
2047 dev = bbio->stripes[mirror_num-1].dev;
2048 btrfs_put_bbio(bbio);
2049 if (!dev || !dev->bdev || !dev->writeable) {
2050 btrfs_bio_counter_dec(fs_info);
2054 bio->bi_bdev = dev->bdev;
2055 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
2056 bio_add_page(bio, page, length, pg_offset);
2058 if (btrfsic_submit_bio_wait(bio)) {
2059 /* try to remap that extent elsewhere? */
2060 btrfs_bio_counter_dec(fs_info);
2062 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2066 btrfs_info_rl_in_rcu(fs_info,
2067 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2068 btrfs_ino(inode), start,
2069 rcu_str_deref(dev->name), sector);
2070 btrfs_bio_counter_dec(fs_info);
2075 int repair_eb_io_failure(struct btrfs_fs_info *fs_info,
2076 struct extent_buffer *eb, int mirror_num)
2078 u64 start = eb->start;
2079 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
2082 if (fs_info->sb->s_flags & MS_RDONLY)
2085 for (i = 0; i < num_pages; i++) {
2086 struct page *p = eb->pages[i];
2088 ret = repair_io_failure(fs_info->btree_inode, start,
2089 PAGE_SIZE, start, p,
2090 start - page_offset(p), mirror_num);
2100 * each time an IO finishes, we do a fast check in the IO failure tree
2101 * to see if we need to process or clean up an io_failure_record
2103 int clean_io_failure(struct inode *inode, u64 start, struct page *page,
2104 unsigned int pg_offset)
2107 struct io_failure_record *failrec;
2108 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2109 struct extent_state *state;
2114 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
2115 (u64)-1, 1, EXTENT_DIRTY, 0);
2119 ret = get_state_failrec(&BTRFS_I(inode)->io_failure_tree, start,
2124 BUG_ON(!failrec->this_mirror);
2126 if (failrec->in_validation) {
2127 /* there was no real error, just free the record */
2128 btrfs_debug(fs_info,
2129 "clean_io_failure: freeing dummy error at %llu",
2133 if (fs_info->sb->s_flags & MS_RDONLY)
2136 spin_lock(&BTRFS_I(inode)->io_tree.lock);
2137 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
2140 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
2142 if (state && state->start <= failrec->start &&
2143 state->end >= failrec->start + failrec->len - 1) {
2144 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2146 if (num_copies > 1) {
2147 repair_io_failure(inode, start, failrec->len,
2148 failrec->logical, page,
2149 pg_offset, failrec->failed_mirror);
2154 free_io_failure(inode, failrec);
2160 * Can be called when
2161 * - hold extent lock
2162 * - under ordered extent
2163 * - the inode is freeing
2165 void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end)
2167 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2168 struct io_failure_record *failrec;
2169 struct extent_state *state, *next;
2171 if (RB_EMPTY_ROOT(&failure_tree->state))
2174 spin_lock(&failure_tree->lock);
2175 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2177 if (state->start > end)
2180 ASSERT(state->end <= end);
2182 next = next_state(state);
2184 failrec = state->failrec;
2185 free_extent_state(state);
2190 spin_unlock(&failure_tree->lock);
2193 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2194 struct io_failure_record **failrec_ret)
2196 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2197 struct io_failure_record *failrec;
2198 struct extent_map *em;
2199 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2200 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2201 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2205 ret = get_state_failrec(failure_tree, start, &failrec);
2207 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2211 failrec->start = start;
2212 failrec->len = end - start + 1;
2213 failrec->this_mirror = 0;
2214 failrec->bio_flags = 0;
2215 failrec->in_validation = 0;
2217 read_lock(&em_tree->lock);
2218 em = lookup_extent_mapping(em_tree, start, failrec->len);
2220 read_unlock(&em_tree->lock);
2225 if (em->start > start || em->start + em->len <= start) {
2226 free_extent_map(em);
2229 read_unlock(&em_tree->lock);
2235 logical = start - em->start;
2236 logical = em->block_start + logical;
2237 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2238 logical = em->block_start;
2239 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2240 extent_set_compress_type(&failrec->bio_flags,
2244 btrfs_debug(fs_info,
2245 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2246 logical, start, failrec->len);
2248 failrec->logical = logical;
2249 free_extent_map(em);
2251 /* set the bits in the private failure tree */
2252 ret = set_extent_bits(failure_tree, start, end,
2253 EXTENT_LOCKED | EXTENT_DIRTY);
2255 ret = set_state_failrec(failure_tree, start, failrec);
2256 /* set the bits in the inode's tree */
2258 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2264 btrfs_debug(fs_info,
2265 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2266 failrec->logical, failrec->start, failrec->len,
2267 failrec->in_validation);
2269 * when data can be on disk more than twice, add to failrec here
2270 * (e.g. with a list for failed_mirror) to make
2271 * clean_io_failure() clean all those errors at once.
2275 *failrec_ret = failrec;
2280 int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
2281 struct io_failure_record *failrec, int failed_mirror)
2283 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2286 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
2287 if (num_copies == 1) {
2289 * we only have a single copy of the data, so don't bother with
2290 * all the retry and error correction code that follows. no
2291 * matter what the error is, it is very likely to persist.
2293 btrfs_debug(fs_info,
2294 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2295 num_copies, failrec->this_mirror, failed_mirror);
2300 * there are two premises:
2301 * a) deliver good data to the caller
2302 * b) correct the bad sectors on disk
2304 if (failed_bio->bi_vcnt > 1) {
2306 * to fulfill b), we need to know the exact failing sectors, as
2307 * we don't want to rewrite any more than the failed ones. thus,
2308 * we need separate read requests for the failed bio
2310 * if the following BUG_ON triggers, our validation request got
2311 * merged. we need separate requests for our algorithm to work.
2313 BUG_ON(failrec->in_validation);
2314 failrec->in_validation = 1;
2315 failrec->this_mirror = failed_mirror;
2318 * we're ready to fulfill a) and b) alongside. get a good copy
2319 * of the failed sector and if we succeed, we have setup
2320 * everything for repair_io_failure to do the rest for us.
2322 if (failrec->in_validation) {
2323 BUG_ON(failrec->this_mirror != failed_mirror);
2324 failrec->in_validation = 0;
2325 failrec->this_mirror = 0;
2327 failrec->failed_mirror = failed_mirror;
2328 failrec->this_mirror++;
2329 if (failrec->this_mirror == failed_mirror)
2330 failrec->this_mirror++;
2333 if (failrec->this_mirror > num_copies) {
2334 btrfs_debug(fs_info,
2335 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2336 num_copies, failrec->this_mirror, failed_mirror);
2344 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
2345 struct io_failure_record *failrec,
2346 struct page *page, int pg_offset, int icsum,
2347 bio_end_io_t *endio_func, void *data)
2349 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2351 struct btrfs_io_bio *btrfs_failed_bio;
2352 struct btrfs_io_bio *btrfs_bio;
2354 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2358 bio->bi_end_io = endio_func;
2359 bio->bi_iter.bi_sector = failrec->logical >> 9;
2360 bio->bi_bdev = fs_info->fs_devices->latest_bdev;
2361 bio->bi_iter.bi_size = 0;
2362 bio->bi_private = data;
2364 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2365 if (btrfs_failed_bio->csum) {
2366 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2368 btrfs_bio = btrfs_io_bio(bio);
2369 btrfs_bio->csum = btrfs_bio->csum_inline;
2371 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
2375 bio_add_page(bio, page, failrec->len, pg_offset);
2381 * this is a generic handler for readpage errors (default
2382 * readpage_io_failed_hook). if other copies exist, read those and write back
2383 * good data to the failed position. does not investigate in remapping the
2384 * failed extent elsewhere, hoping the device will be smart enough to do this as
2388 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2389 struct page *page, u64 start, u64 end,
2392 struct io_failure_record *failrec;
2393 struct inode *inode = page->mapping->host;
2394 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2399 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2401 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2405 ret = btrfs_check_repairable(inode, failed_bio, failrec, failed_mirror);
2407 free_io_failure(inode, failrec);
2411 if (failed_bio->bi_vcnt > 1)
2412 read_mode |= REQ_FAILFAST_DEV;
2414 phy_offset >>= inode->i_sb->s_blocksize_bits;
2415 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
2416 start - page_offset(page),
2417 (int)phy_offset, failed_bio->bi_end_io,
2420 free_io_failure(inode, failrec);
2423 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
2425 btrfs_debug(btrfs_sb(inode->i_sb),
2426 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2427 read_mode, failrec->this_mirror, failrec->in_validation);
2429 ret = tree->ops->submit_bio_hook(inode, bio, failrec->this_mirror,
2430 failrec->bio_flags, 0);
2432 free_io_failure(inode, failrec);
2439 /* lots and lots of room for performance fixes in the end_bio funcs */
2441 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2443 int uptodate = (err == 0);
2444 struct extent_io_tree *tree;
2447 tree = &BTRFS_I(page->mapping->host)->io_tree;
2449 if (tree->ops && tree->ops->writepage_end_io_hook) {
2450 ret = tree->ops->writepage_end_io_hook(page, start,
2451 end, NULL, uptodate);
2457 ClearPageUptodate(page);
2459 ret = ret < 0 ? ret : -EIO;
2460 mapping_set_error(page->mapping, ret);
2465 * after a writepage IO is done, we need to:
2466 * clear the uptodate bits on error
2467 * clear the writeback bits in the extent tree for this IO
2468 * end_page_writeback if the page has no more pending IO
2470 * Scheduling is not allowed, so the extent state tree is expected
2471 * to have one and only one object corresponding to this IO.
2473 static void end_bio_extent_writepage(struct bio *bio)
2475 struct bio_vec *bvec;
2480 bio_for_each_segment_all(bvec, bio, i) {
2481 struct page *page = bvec->bv_page;
2482 struct inode *inode = page->mapping->host;
2483 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2485 /* We always issue full-page reads, but if some block
2486 * in a page fails to read, blk_update_request() will
2487 * advance bv_offset and adjust bv_len to compensate.
2488 * Print a warning for nonzero offsets, and an error
2489 * if they don't add up to a full page. */
2490 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2491 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2493 "partial page write in btrfs with offset %u and length %u",
2494 bvec->bv_offset, bvec->bv_len);
2497 "incomplete page write in btrfs with offset %u and length %u",
2498 bvec->bv_offset, bvec->bv_len);
2501 start = page_offset(page);
2502 end = start + bvec->bv_offset + bvec->bv_len - 1;
2504 end_extent_writepage(page, bio->bi_error, start, end);
2505 end_page_writeback(page);
2512 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2515 struct extent_state *cached = NULL;
2516 u64 end = start + len - 1;
2518 if (uptodate && tree->track_uptodate)
2519 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2520 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2524 * after a readpage IO is done, we need to:
2525 * clear the uptodate bits on error
2526 * set the uptodate bits if things worked
2527 * set the page up to date if all extents in the tree are uptodate
2528 * clear the lock bit in the extent tree
2529 * unlock the page if there are no other extents locked for it
2531 * Scheduling is not allowed, so the extent state tree is expected
2532 * to have one and only one object corresponding to this IO.
2534 static void end_bio_extent_readpage(struct bio *bio)
2536 struct bio_vec *bvec;
2537 int uptodate = !bio->bi_error;
2538 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2539 struct extent_io_tree *tree;
2544 u64 extent_start = 0;
2550 bio_for_each_segment_all(bvec, bio, i) {
2551 struct page *page = bvec->bv_page;
2552 struct inode *inode = page->mapping->host;
2553 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2555 btrfs_debug(fs_info,
2556 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2557 (u64)bio->bi_iter.bi_sector, bio->bi_error,
2558 io_bio->mirror_num);
2559 tree = &BTRFS_I(inode)->io_tree;
2561 /* We always issue full-page reads, but if some block
2562 * in a page fails to read, blk_update_request() will
2563 * advance bv_offset and adjust bv_len to compensate.
2564 * Print a warning for nonzero offsets, and an error
2565 * if they don't add up to a full page. */
2566 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2567 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2569 "partial page read in btrfs with offset %u and length %u",
2570 bvec->bv_offset, bvec->bv_len);
2573 "incomplete page read in btrfs with offset %u and length %u",
2574 bvec->bv_offset, bvec->bv_len);
2577 start = page_offset(page);
2578 end = start + bvec->bv_offset + bvec->bv_len - 1;
2581 mirror = io_bio->mirror_num;
2582 if (likely(uptodate && tree->ops &&
2583 tree->ops->readpage_end_io_hook)) {
2584 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2590 clean_io_failure(inode, start, page, 0);
2593 if (likely(uptodate))
2596 if (tree->ops && tree->ops->readpage_io_failed_hook) {
2597 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2598 if (!ret && !bio->bi_error)
2602 * The generic bio_readpage_error handles errors the
2603 * following way: If possible, new read requests are
2604 * created and submitted and will end up in
2605 * end_bio_extent_readpage as well (if we're lucky, not
2606 * in the !uptodate case). In that case it returns 0 and
2607 * we just go on with the next page in our bio. If it
2608 * can't handle the error it will return -EIO and we
2609 * remain responsible for that page.
2611 ret = bio_readpage_error(bio, offset, page, start, end,
2614 uptodate = !bio->bi_error;
2620 if (likely(uptodate)) {
2621 loff_t i_size = i_size_read(inode);
2622 pgoff_t end_index = i_size >> PAGE_SHIFT;
2625 /* Zero out the end if this page straddles i_size */
2626 off = i_size & (PAGE_SIZE-1);
2627 if (page->index == end_index && off)
2628 zero_user_segment(page, off, PAGE_SIZE);
2629 SetPageUptodate(page);
2631 ClearPageUptodate(page);
2637 if (unlikely(!uptodate)) {
2639 endio_readpage_release_extent(tree,
2645 endio_readpage_release_extent(tree, start,
2646 end - start + 1, 0);
2647 } else if (!extent_len) {
2648 extent_start = start;
2649 extent_len = end + 1 - start;
2650 } else if (extent_start + extent_len == start) {
2651 extent_len += end + 1 - start;
2653 endio_readpage_release_extent(tree, extent_start,
2654 extent_len, uptodate);
2655 extent_start = start;
2656 extent_len = end + 1 - start;
2661 endio_readpage_release_extent(tree, extent_start, extent_len,
2664 io_bio->end_io(io_bio, bio->bi_error);
2669 * this allocates from the btrfs_bioset. We're returning a bio right now
2670 * but you can call btrfs_io_bio for the appropriate container_of magic
2673 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2676 struct btrfs_io_bio *btrfs_bio;
2679 bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset);
2681 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2682 while (!bio && (nr_vecs /= 2)) {
2683 bio = bio_alloc_bioset(gfp_flags,
2684 nr_vecs, btrfs_bioset);
2689 bio->bi_bdev = bdev;
2690 bio->bi_iter.bi_sector = first_sector;
2691 btrfs_bio = btrfs_io_bio(bio);
2692 btrfs_bio->csum = NULL;
2693 btrfs_bio->csum_allocated = NULL;
2694 btrfs_bio->end_io = NULL;
2699 struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
2701 struct btrfs_io_bio *btrfs_bio;
2704 new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset);
2706 btrfs_bio = btrfs_io_bio(new);
2707 btrfs_bio->csum = NULL;
2708 btrfs_bio->csum_allocated = NULL;
2709 btrfs_bio->end_io = NULL;
2714 /* this also allocates from the btrfs_bioset */
2715 struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
2717 struct btrfs_io_bio *btrfs_bio;
2720 bio = bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
2722 btrfs_bio = btrfs_io_bio(bio);
2723 btrfs_bio->csum = NULL;
2724 btrfs_bio->csum_allocated = NULL;
2725 btrfs_bio->end_io = NULL;
2731 static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
2732 unsigned long bio_flags)
2735 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2736 struct page *page = bvec->bv_page;
2737 struct extent_io_tree *tree = bio->bi_private;
2740 start = page_offset(page) + bvec->bv_offset;
2742 bio->bi_private = NULL;
2745 if (tree->ops && tree->ops->submit_bio_hook)
2746 ret = tree->ops->submit_bio_hook(page->mapping->host, bio,
2747 mirror_num, bio_flags, start);
2749 btrfsic_submit_bio(bio);
2755 static int merge_bio(struct extent_io_tree *tree, struct page *page,
2756 unsigned long offset, size_t size, struct bio *bio,
2757 unsigned long bio_flags)
2760 if (tree->ops && tree->ops->merge_bio_hook)
2761 ret = tree->ops->merge_bio_hook(page, offset, size, bio,
2767 static int submit_extent_page(int op, int op_flags, struct extent_io_tree *tree,
2768 struct writeback_control *wbc,
2769 struct page *page, sector_t sector,
2770 size_t size, unsigned long offset,
2771 struct block_device *bdev,
2772 struct bio **bio_ret,
2773 unsigned long max_pages,
2774 bio_end_io_t end_io_func,
2776 unsigned long prev_bio_flags,
2777 unsigned long bio_flags,
2778 bool force_bio_submit)
2783 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2784 size_t page_size = min_t(size_t, size, PAGE_SIZE);
2786 if (bio_ret && *bio_ret) {
2789 contig = bio->bi_iter.bi_sector == sector;
2791 contig = bio_end_sector(bio) == sector;
2793 if (prev_bio_flags != bio_flags || !contig ||
2795 merge_bio(tree, page, offset, page_size, bio, bio_flags) ||
2796 bio_add_page(bio, page, page_size, offset) < page_size) {
2797 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
2805 wbc_account_io(wbc, page, page_size);
2810 bio = btrfs_bio_alloc(bdev, sector, BIO_MAX_PAGES,
2811 GFP_NOFS | __GFP_HIGH);
2815 bio_add_page(bio, page, page_size, offset);
2816 bio->bi_end_io = end_io_func;
2817 bio->bi_private = tree;
2818 bio_set_op_attrs(bio, op, op_flags);
2820 wbc_init_bio(wbc, bio);
2821 wbc_account_io(wbc, page, page_size);
2827 ret = submit_one_bio(bio, mirror_num, bio_flags);
2832 static void attach_extent_buffer_page(struct extent_buffer *eb,
2835 if (!PagePrivate(page)) {
2836 SetPagePrivate(page);
2838 set_page_private(page, (unsigned long)eb);
2840 WARN_ON(page->private != (unsigned long)eb);
2844 void set_page_extent_mapped(struct page *page)
2846 if (!PagePrivate(page)) {
2847 SetPagePrivate(page);
2849 set_page_private(page, EXTENT_PAGE_PRIVATE);
2853 static struct extent_map *
2854 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
2855 u64 start, u64 len, get_extent_t *get_extent,
2856 struct extent_map **em_cached)
2858 struct extent_map *em;
2860 if (em_cached && *em_cached) {
2862 if (extent_map_in_tree(em) && start >= em->start &&
2863 start < extent_map_end(em)) {
2864 atomic_inc(&em->refs);
2868 free_extent_map(em);
2872 em = get_extent(inode, page, pg_offset, start, len, 0);
2873 if (em_cached && !IS_ERR_OR_NULL(em)) {
2875 atomic_inc(&em->refs);
2881 * basic readpage implementation. Locked extent state structs are inserted
2882 * into the tree that are removed when the IO is done (by the end_io
2884 * XXX JDM: This needs looking at to ensure proper page locking
2885 * return 0 on success, otherwise return error
2887 static int __do_readpage(struct extent_io_tree *tree,
2889 get_extent_t *get_extent,
2890 struct extent_map **em_cached,
2891 struct bio **bio, int mirror_num,
2892 unsigned long *bio_flags, int read_flags,
2895 struct inode *inode = page->mapping->host;
2896 u64 start = page_offset(page);
2897 u64 page_end = start + PAGE_SIZE - 1;
2901 u64 last_byte = i_size_read(inode);
2905 struct extent_map *em;
2906 struct block_device *bdev;
2909 size_t pg_offset = 0;
2911 size_t disk_io_size;
2912 size_t blocksize = inode->i_sb->s_blocksize;
2913 unsigned long this_bio_flag = 0;
2915 set_page_extent_mapped(page);
2918 if (!PageUptodate(page)) {
2919 if (cleancache_get_page(page) == 0) {
2920 BUG_ON(blocksize != PAGE_SIZE);
2921 unlock_extent(tree, start, end);
2926 if (page->index == last_byte >> PAGE_SHIFT) {
2928 size_t zero_offset = last_byte & (PAGE_SIZE - 1);
2931 iosize = PAGE_SIZE - zero_offset;
2932 userpage = kmap_atomic(page);
2933 memset(userpage + zero_offset, 0, iosize);
2934 flush_dcache_page(page);
2935 kunmap_atomic(userpage);
2938 while (cur <= end) {
2939 unsigned long pnr = (last_byte >> PAGE_SHIFT) + 1;
2940 bool force_bio_submit = false;
2942 if (cur >= last_byte) {
2944 struct extent_state *cached = NULL;
2946 iosize = PAGE_SIZE - pg_offset;
2947 userpage = kmap_atomic(page);
2948 memset(userpage + pg_offset, 0, iosize);
2949 flush_dcache_page(page);
2950 kunmap_atomic(userpage);
2951 set_extent_uptodate(tree, cur, cur + iosize - 1,
2953 unlock_extent_cached(tree, cur,
2958 em = __get_extent_map(inode, page, pg_offset, cur,
2959 end - cur + 1, get_extent, em_cached);
2960 if (IS_ERR_OR_NULL(em)) {
2962 unlock_extent(tree, cur, end);
2965 extent_offset = cur - em->start;
2966 BUG_ON(extent_map_end(em) <= cur);
2969 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2970 this_bio_flag |= EXTENT_BIO_COMPRESSED;
2971 extent_set_compress_type(&this_bio_flag,
2975 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2976 cur_end = min(extent_map_end(em) - 1, end);
2977 iosize = ALIGN(iosize, blocksize);
2978 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2979 disk_io_size = em->block_len;
2980 sector = em->block_start >> 9;
2982 sector = (em->block_start + extent_offset) >> 9;
2983 disk_io_size = iosize;
2986 block_start = em->block_start;
2987 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2988 block_start = EXTENT_MAP_HOLE;
2991 * If we have a file range that points to a compressed extent
2992 * and it's followed by a consecutive file range that points to
2993 * to the same compressed extent (possibly with a different
2994 * offset and/or length, so it either points to the whole extent
2995 * or only part of it), we must make sure we do not submit a
2996 * single bio to populate the pages for the 2 ranges because
2997 * this makes the compressed extent read zero out the pages
2998 * belonging to the 2nd range. Imagine the following scenario:
3001 * [0 - 8K] [8K - 24K]
3004 * points to extent X, points to extent X,
3005 * offset 4K, length of 8K offset 0, length 16K
3007 * [extent X, compressed length = 4K uncompressed length = 16K]
3009 * If the bio to read the compressed extent covers both ranges,
3010 * it will decompress extent X into the pages belonging to the
3011 * first range and then it will stop, zeroing out the remaining
3012 * pages that belong to the other range that points to extent X.
3013 * So here we make sure we submit 2 bios, one for the first
3014 * range and another one for the third range. Both will target
3015 * the same physical extent from disk, but we can't currently
3016 * make the compressed bio endio callback populate the pages
3017 * for both ranges because each compressed bio is tightly
3018 * coupled with a single extent map, and each range can have
3019 * an extent map with a different offset value relative to the
3020 * uncompressed data of our extent and different lengths. This
3021 * is a corner case so we prioritize correctness over
3022 * non-optimal behavior (submitting 2 bios for the same extent).
3024 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3025 prev_em_start && *prev_em_start != (u64)-1 &&
3026 *prev_em_start != em->orig_start)
3027 force_bio_submit = true;
3030 *prev_em_start = em->orig_start;
3032 free_extent_map(em);
3035 /* we've found a hole, just zero and go on */
3036 if (block_start == EXTENT_MAP_HOLE) {
3038 struct extent_state *cached = NULL;
3040 userpage = kmap_atomic(page);
3041 memset(userpage + pg_offset, 0, iosize);
3042 flush_dcache_page(page);
3043 kunmap_atomic(userpage);
3045 set_extent_uptodate(tree, cur, cur + iosize - 1,
3047 unlock_extent_cached(tree, cur,
3051 pg_offset += iosize;
3054 /* the get_extent function already copied into the page */
3055 if (test_range_bit(tree, cur, cur_end,
3056 EXTENT_UPTODATE, 1, NULL)) {
3057 check_page_uptodate(tree, page);
3058 unlock_extent(tree, cur, cur + iosize - 1);
3060 pg_offset += iosize;
3063 /* we have an inline extent but it didn't get marked up
3064 * to date. Error out
3066 if (block_start == EXTENT_MAP_INLINE) {
3068 unlock_extent(tree, cur, cur + iosize - 1);
3070 pg_offset += iosize;
3075 ret = submit_extent_page(REQ_OP_READ, read_flags, tree, NULL,
3076 page, sector, disk_io_size, pg_offset,
3078 end_bio_extent_readpage, mirror_num,
3084 *bio_flags = this_bio_flag;
3087 unlock_extent(tree, cur, cur + iosize - 1);
3091 pg_offset += iosize;
3095 if (!PageError(page))
3096 SetPageUptodate(page);
3102 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
3103 struct page *pages[], int nr_pages,
3105 get_extent_t *get_extent,
3106 struct extent_map **em_cached,
3107 struct bio **bio, int mirror_num,
3108 unsigned long *bio_flags,
3111 struct inode *inode;
3112 struct btrfs_ordered_extent *ordered;
3115 inode = pages[0]->mapping->host;
3117 lock_extent(tree, start, end);
3118 ordered = btrfs_lookup_ordered_range(inode, start,
3122 unlock_extent(tree, start, end);
3123 btrfs_start_ordered_extent(inode, ordered, 1);
3124 btrfs_put_ordered_extent(ordered);
3127 for (index = 0; index < nr_pages; index++) {
3128 __do_readpage(tree, pages[index], get_extent, em_cached, bio,
3129 mirror_num, bio_flags, 0, prev_em_start);
3130 put_page(pages[index]);
3134 static void __extent_readpages(struct extent_io_tree *tree,
3135 struct page *pages[],
3136 int nr_pages, get_extent_t *get_extent,
3137 struct extent_map **em_cached,
3138 struct bio **bio, int mirror_num,
3139 unsigned long *bio_flags,
3146 int first_index = 0;
3148 for (index = 0; index < nr_pages; index++) {
3149 page_start = page_offset(pages[index]);
3152 end = start + PAGE_SIZE - 1;
3153 first_index = index;
3154 } else if (end + 1 == page_start) {
3157 __do_contiguous_readpages(tree, &pages[first_index],
3158 index - first_index, start,
3159 end, get_extent, em_cached,
3160 bio, mirror_num, bio_flags,
3163 end = start + PAGE_SIZE - 1;
3164 first_index = index;
3169 __do_contiguous_readpages(tree, &pages[first_index],
3170 index - first_index, start,
3171 end, get_extent, em_cached, bio,
3172 mirror_num, bio_flags,
3176 static int __extent_read_full_page(struct extent_io_tree *tree,
3178 get_extent_t *get_extent,
3179 struct bio **bio, int mirror_num,
3180 unsigned long *bio_flags, int read_flags)
3182 struct inode *inode = page->mapping->host;
3183 struct btrfs_ordered_extent *ordered;
3184 u64 start = page_offset(page);
3185 u64 end = start + PAGE_SIZE - 1;
3189 lock_extent(tree, start, end);
3190 ordered = btrfs_lookup_ordered_range(inode, start,
3194 unlock_extent(tree, start, end);
3195 btrfs_start_ordered_extent(inode, ordered, 1);
3196 btrfs_put_ordered_extent(ordered);
3199 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3200 bio_flags, read_flags, NULL);
3204 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3205 get_extent_t *get_extent, int mirror_num)
3207 struct bio *bio = NULL;
3208 unsigned long bio_flags = 0;
3211 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3214 ret = submit_one_bio(bio, mirror_num, bio_flags);
3218 static void update_nr_written(struct page *page, struct writeback_control *wbc,
3219 unsigned long nr_written)
3221 wbc->nr_to_write -= nr_written;
3225 * helper for __extent_writepage, doing all of the delayed allocation setup.
3227 * This returns 1 if our fill_delalloc function did all the work required
3228 * to write the page (copy into inline extent). In this case the IO has
3229 * been started and the page is already unlocked.
3231 * This returns 0 if all went well (page still locked)
3232 * This returns < 0 if there were errors (page still locked)
3234 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3235 struct page *page, struct writeback_control *wbc,
3236 struct extent_page_data *epd,
3238 unsigned long *nr_written)
3240 struct extent_io_tree *tree = epd->tree;
3241 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3243 u64 delalloc_to_write = 0;
3244 u64 delalloc_end = 0;
3246 int page_started = 0;
3248 if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
3251 while (delalloc_end < page_end) {
3252 nr_delalloc = find_lock_delalloc_range(inode, tree,
3256 BTRFS_MAX_EXTENT_SIZE);
3257 if (nr_delalloc == 0) {
3258 delalloc_start = delalloc_end + 1;
3261 ret = tree->ops->fill_delalloc(inode, page,
3266 /* File system has been set read-only */
3269 /* fill_delalloc should be return < 0 for error
3270 * but just in case, we use > 0 here meaning the
3271 * IO is started, so we don't want to return > 0
3272 * unless things are going well.
3274 ret = ret < 0 ? ret : -EIO;
3278 * delalloc_end is already one less than the total length, so
3279 * we don't subtract one from PAGE_SIZE
3281 delalloc_to_write += (delalloc_end - delalloc_start +
3282 PAGE_SIZE) >> PAGE_SHIFT;
3283 delalloc_start = delalloc_end + 1;
3285 if (wbc->nr_to_write < delalloc_to_write) {
3288 if (delalloc_to_write < thresh * 2)
3289 thresh = delalloc_to_write;
3290 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3294 /* did the fill delalloc function already unlock and start
3299 * we've unlocked the page, so we can't update
3300 * the mapping's writeback index, just update
3303 wbc->nr_to_write -= *nr_written;
3314 * helper for __extent_writepage. This calls the writepage start hooks,
3315 * and does the loop to map the page into extents and bios.
3317 * We return 1 if the IO is started and the page is unlocked,
3318 * 0 if all went well (page still locked)
3319 * < 0 if there were errors (page still locked)
3321 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3323 struct writeback_control *wbc,
3324 struct extent_page_data *epd,
3326 unsigned long nr_written,
3327 int write_flags, int *nr_ret)
3329 struct extent_io_tree *tree = epd->tree;
3330 u64 start = page_offset(page);
3331 u64 page_end = start + PAGE_SIZE - 1;
3338 struct extent_state *cached_state = NULL;
3339 struct extent_map *em;
3340 struct block_device *bdev;
3341 size_t pg_offset = 0;
3347 if (tree->ops && tree->ops->writepage_start_hook) {
3348 ret = tree->ops->writepage_start_hook(page, start,
3351 /* Fixup worker will requeue */
3353 wbc->pages_skipped++;
3355 redirty_page_for_writepage(wbc, page);
3357 update_nr_written(page, wbc, nr_written);
3365 * we don't want to touch the inode after unlocking the page,
3366 * so we update the mapping writeback index now
3368 update_nr_written(page, wbc, nr_written + 1);
3371 if (i_size <= start) {
3372 if (tree->ops && tree->ops->writepage_end_io_hook)
3373 tree->ops->writepage_end_io_hook(page, start,
3378 blocksize = inode->i_sb->s_blocksize;
3380 while (cur <= end) {
3382 unsigned long max_nr;
3384 if (cur >= i_size) {
3385 if (tree->ops && tree->ops->writepage_end_io_hook)
3386 tree->ops->writepage_end_io_hook(page, cur,
3390 em = epd->get_extent(inode, page, pg_offset, cur,
3392 if (IS_ERR_OR_NULL(em)) {
3394 ret = PTR_ERR_OR_ZERO(em);
3398 extent_offset = cur - em->start;
3399 em_end = extent_map_end(em);
3400 BUG_ON(em_end <= cur);
3402 iosize = min(em_end - cur, end - cur + 1);
3403 iosize = ALIGN(iosize, blocksize);
3404 sector = (em->block_start + extent_offset) >> 9;
3406 block_start = em->block_start;
3407 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3408 free_extent_map(em);
3412 * compressed and inline extents are written through other
3415 if (compressed || block_start == EXTENT_MAP_HOLE ||
3416 block_start == EXTENT_MAP_INLINE) {
3418 * end_io notification does not happen here for
3419 * compressed extents
3421 if (!compressed && tree->ops &&
3422 tree->ops->writepage_end_io_hook)
3423 tree->ops->writepage_end_io_hook(page, cur,
3426 else if (compressed) {
3427 /* we don't want to end_page_writeback on
3428 * a compressed extent. this happens
3435 pg_offset += iosize;
3439 max_nr = (i_size >> PAGE_SHIFT) + 1;
3441 set_range_writeback(tree, cur, cur + iosize - 1);
3442 if (!PageWriteback(page)) {
3443 btrfs_err(BTRFS_I(inode)->root->fs_info,
3444 "page %lu not writeback, cur %llu end %llu",
3445 page->index, cur, end);
3448 ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
3449 page, sector, iosize, pg_offset,
3450 bdev, &epd->bio, max_nr,
3451 end_bio_extent_writepage,
3457 pg_offset += iosize;
3465 /* drop our reference on any cached states */
3466 free_extent_state(cached_state);
3471 * the writepage semantics are similar to regular writepage. extent
3472 * records are inserted to lock ranges in the tree, and as dirty areas
3473 * are found, they are marked writeback. Then the lock bits are removed
3474 * and the end_io handler clears the writeback ranges
3476 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3479 struct inode *inode = page->mapping->host;
3480 struct extent_page_data *epd = data;
3481 u64 start = page_offset(page);
3482 u64 page_end = start + PAGE_SIZE - 1;
3485 size_t pg_offset = 0;
3486 loff_t i_size = i_size_read(inode);
3487 unsigned long end_index = i_size >> PAGE_SHIFT;
3488 int write_flags = 0;
3489 unsigned long nr_written = 0;
3491 if (wbc->sync_mode == WB_SYNC_ALL)
3492 write_flags = REQ_SYNC;
3494 trace___extent_writepage(page, inode, wbc);
3496 WARN_ON(!PageLocked(page));
3498 ClearPageError(page);
3500 pg_offset = i_size & (PAGE_SIZE - 1);
3501 if (page->index > end_index ||
3502 (page->index == end_index && !pg_offset)) {
3503 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3508 if (page->index == end_index) {
3511 userpage = kmap_atomic(page);
3512 memset(userpage + pg_offset, 0,
3513 PAGE_SIZE - pg_offset);
3514 kunmap_atomic(userpage);
3515 flush_dcache_page(page);
3520 set_page_extent_mapped(page);
3522 ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
3528 ret = __extent_writepage_io(inode, page, wbc, epd,
3529 i_size, nr_written, write_flags, &nr);
3535 /* make sure the mapping tag for page dirty gets cleared */
3536 set_page_writeback(page);
3537 end_page_writeback(page);
3539 if (PageError(page)) {
3540 ret = ret < 0 ? ret : -EIO;
3541 end_extent_writepage(page, ret, start, page_end);
3550 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3552 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3553 TASK_UNINTERRUPTIBLE);
3556 static noinline_for_stack int
3557 lock_extent_buffer_for_io(struct extent_buffer *eb,
3558 struct btrfs_fs_info *fs_info,
3559 struct extent_page_data *epd)
3561 unsigned long i, num_pages;
3565 if (!btrfs_try_tree_write_lock(eb)) {
3567 flush_write_bio(epd);
3568 btrfs_tree_lock(eb);
3571 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3572 btrfs_tree_unlock(eb);
3576 flush_write_bio(epd);
3580 wait_on_extent_buffer_writeback(eb);
3581 btrfs_tree_lock(eb);
3582 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3584 btrfs_tree_unlock(eb);
3589 * We need to do this to prevent races in people who check if the eb is
3590 * under IO since we can end up having no IO bits set for a short period
3593 spin_lock(&eb->refs_lock);
3594 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3595 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3596 spin_unlock(&eb->refs_lock);
3597 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3598 __percpu_counter_add(&fs_info->dirty_metadata_bytes,
3600 fs_info->dirty_metadata_batch);
3603 spin_unlock(&eb->refs_lock);
3606 btrfs_tree_unlock(eb);
3611 num_pages = num_extent_pages(eb->start, eb->len);
3612 for (i = 0; i < num_pages; i++) {
3613 struct page *p = eb->pages[i];
3615 if (!trylock_page(p)) {
3617 flush_write_bio(epd);
3627 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3629 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3630 smp_mb__after_atomic();
3631 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3634 static void set_btree_ioerr(struct page *page)
3636 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3639 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3643 * If writeback for a btree extent that doesn't belong to a log tree
3644 * failed, increment the counter transaction->eb_write_errors.
3645 * We do this because while the transaction is running and before it's
3646 * committing (when we call filemap_fdata[write|wait]_range against
3647 * the btree inode), we might have
3648 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3649 * returns an error or an error happens during writeback, when we're
3650 * committing the transaction we wouldn't know about it, since the pages
3651 * can be no longer dirty nor marked anymore for writeback (if a
3652 * subsequent modification to the extent buffer didn't happen before the
3653 * transaction commit), which makes filemap_fdata[write|wait]_range not
3654 * able to find the pages tagged with SetPageError at transaction
3655 * commit time. So if this happens we must abort the transaction,
3656 * otherwise we commit a super block with btree roots that point to
3657 * btree nodes/leafs whose content on disk is invalid - either garbage
3658 * or the content of some node/leaf from a past generation that got
3659 * cowed or deleted and is no longer valid.
3661 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3662 * not be enough - we need to distinguish between log tree extents vs
3663 * non-log tree extents, and the next filemap_fdatawait_range() call
3664 * will catch and clear such errors in the mapping - and that call might
3665 * be from a log sync and not from a transaction commit. Also, checking
3666 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3667 * not done and would not be reliable - the eb might have been released
3668 * from memory and reading it back again means that flag would not be
3669 * set (since it's a runtime flag, not persisted on disk).
3671 * Using the flags below in the btree inode also makes us achieve the
3672 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3673 * writeback for all dirty pages and before filemap_fdatawait_range()
3674 * is called, the writeback for all dirty pages had already finished
3675 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3676 * filemap_fdatawait_range() would return success, as it could not know
3677 * that writeback errors happened (the pages were no longer tagged for
3680 switch (eb->log_index) {
3682 set_bit(BTRFS_FS_BTREE_ERR, &eb->fs_info->flags);
3685 set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags);
3688 set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags);
3691 BUG(); /* unexpected, logic error */
3695 static void end_bio_extent_buffer_writepage(struct bio *bio)
3697 struct bio_vec *bvec;
3698 struct extent_buffer *eb;
3701 bio_for_each_segment_all(bvec, bio, i) {
3702 struct page *page = bvec->bv_page;
3704 eb = (struct extent_buffer *)page->private;
3706 done = atomic_dec_and_test(&eb->io_pages);
3708 if (bio->bi_error ||
3709 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3710 ClearPageUptodate(page);
3711 set_btree_ioerr(page);
3714 end_page_writeback(page);
3719 end_extent_buffer_writeback(eb);
3725 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3726 struct btrfs_fs_info *fs_info,
3727 struct writeback_control *wbc,
3728 struct extent_page_data *epd)
3730 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3731 struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
3732 u64 offset = eb->start;
3734 unsigned long i, num_pages;
3735 unsigned long bio_flags = 0;
3736 unsigned long start, end;
3737 int write_flags = (epd->sync_io ? REQ_SYNC : 0) | REQ_META;
3740 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3741 num_pages = num_extent_pages(eb->start, eb->len);
3742 atomic_set(&eb->io_pages, num_pages);
3743 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3744 bio_flags = EXTENT_BIO_TREE_LOG;
3746 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3747 nritems = btrfs_header_nritems(eb);
3748 if (btrfs_header_level(eb) > 0) {
3749 end = btrfs_node_key_ptr_offset(nritems);
3751 memzero_extent_buffer(eb, end, eb->len - end);
3755 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3757 start = btrfs_item_nr_offset(nritems);
3758 end = btrfs_leaf_data(eb) + leaf_data_end(fs_info, eb);
3759 memzero_extent_buffer(eb, start, end - start);
3762 for (i = 0; i < num_pages; i++) {
3763 struct page *p = eb->pages[i];
3765 clear_page_dirty_for_io(p);
3766 set_page_writeback(p);
3767 ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
3768 p, offset >> 9, PAGE_SIZE, 0, bdev,
3770 end_bio_extent_buffer_writepage,
3771 0, epd->bio_flags, bio_flags, false);
3772 epd->bio_flags = bio_flags;
3775 end_page_writeback(p);
3776 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3777 end_extent_buffer_writeback(eb);
3781 offset += PAGE_SIZE;
3782 update_nr_written(p, wbc, 1);
3786 if (unlikely(ret)) {
3787 for (; i < num_pages; i++) {
3788 struct page *p = eb->pages[i];
3789 clear_page_dirty_for_io(p);
3797 int btree_write_cache_pages(struct address_space *mapping,
3798 struct writeback_control *wbc)
3800 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3801 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3802 struct extent_buffer *eb, *prev_eb = NULL;
3803 struct extent_page_data epd = {
3807 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3812 int nr_to_write_done = 0;
3813 struct pagevec pvec;
3816 pgoff_t end; /* Inclusive */
3820 pagevec_init(&pvec, 0);
3821 if (wbc->range_cyclic) {
3822 index = mapping->writeback_index; /* Start from prev offset */
3825 index = wbc->range_start >> PAGE_SHIFT;
3826 end = wbc->range_end >> PAGE_SHIFT;
3829 if (wbc->sync_mode == WB_SYNC_ALL)
3830 tag = PAGECACHE_TAG_TOWRITE;
3832 tag = PAGECACHE_TAG_DIRTY;
3834 if (wbc->sync_mode == WB_SYNC_ALL)
3835 tag_pages_for_writeback(mapping, index, end);
3836 while (!done && !nr_to_write_done && (index <= end) &&
3837 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3838 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3842 for (i = 0; i < nr_pages; i++) {
3843 struct page *page = pvec.pages[i];
3845 if (!PagePrivate(page))
3848 if (!wbc->range_cyclic && page->index > end) {
3853 spin_lock(&mapping->private_lock);
3854 if (!PagePrivate(page)) {
3855 spin_unlock(&mapping->private_lock);
3859 eb = (struct extent_buffer *)page->private;
3862 * Shouldn't happen and normally this would be a BUG_ON
3863 * but no sense in crashing the users box for something
3864 * we can survive anyway.
3867 spin_unlock(&mapping->private_lock);
3871 if (eb == prev_eb) {
3872 spin_unlock(&mapping->private_lock);
3876 ret = atomic_inc_not_zero(&eb->refs);
3877 spin_unlock(&mapping->private_lock);
3882 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3884 free_extent_buffer(eb);
3888 ret = write_one_eb(eb, fs_info, wbc, &epd);
3891 free_extent_buffer(eb);
3894 free_extent_buffer(eb);
3897 * the filesystem may choose to bump up nr_to_write.
3898 * We have to make sure to honor the new nr_to_write
3901 nr_to_write_done = wbc->nr_to_write <= 0;
3903 pagevec_release(&pvec);
3906 if (!scanned && !done) {
3908 * We hit the last page and there is more work to be done: wrap
3909 * back to the start of the file
3915 flush_write_bio(&epd);
3920 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3921 * @mapping: address space structure to write
3922 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3923 * @writepage: function called for each page
3924 * @data: data passed to writepage function
3926 * If a page is already under I/O, write_cache_pages() skips it, even
3927 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3928 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3929 * and msync() need to guarantee that all the data which was dirty at the time
3930 * the call was made get new I/O started against them. If wbc->sync_mode is
3931 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3932 * existing IO to complete.
3934 static int extent_write_cache_pages(struct extent_io_tree *tree,
3935 struct address_space *mapping,
3936 struct writeback_control *wbc,
3937 writepage_t writepage, void *data,
3938 void (*flush_fn)(void *))
3940 struct inode *inode = mapping->host;
3943 int nr_to_write_done = 0;
3944 struct pagevec pvec;
3947 pgoff_t end; /* Inclusive */
3949 int range_whole = 0;
3954 * We have to hold onto the inode so that ordered extents can do their
3955 * work when the IO finishes. The alternative to this is failing to add
3956 * an ordered extent if the igrab() fails there and that is a huge pain
3957 * to deal with, so instead just hold onto the inode throughout the
3958 * writepages operation. If it fails here we are freeing up the inode
3959 * anyway and we'd rather not waste our time writing out stuff that is
3960 * going to be truncated anyway.
3965 pagevec_init(&pvec, 0);
3966 if (wbc->range_cyclic) {
3967 index = mapping->writeback_index; /* Start from prev offset */
3970 index = wbc->range_start >> PAGE_SHIFT;
3971 end = wbc->range_end >> PAGE_SHIFT;
3972 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
3976 if (wbc->sync_mode == WB_SYNC_ALL)
3977 tag = PAGECACHE_TAG_TOWRITE;
3979 tag = PAGECACHE_TAG_DIRTY;
3981 if (wbc->sync_mode == WB_SYNC_ALL)
3982 tag_pages_for_writeback(mapping, index, end);
3984 while (!done && !nr_to_write_done && (index <= end) &&
3985 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3986 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3990 for (i = 0; i < nr_pages; i++) {
3991 struct page *page = pvec.pages[i];
3993 done_index = page->index;
3995 * At this point we hold neither mapping->tree_lock nor
3996 * lock on the page itself: the page may be truncated or
3997 * invalidated (changing page->mapping to NULL), or even
3998 * swizzled back from swapper_space to tmpfs file
4001 if (!trylock_page(page)) {
4006 if (unlikely(page->mapping != mapping)) {
4011 if (!wbc->range_cyclic && page->index > end) {
4017 if (wbc->sync_mode != WB_SYNC_NONE) {
4018 if (PageWriteback(page))
4020 wait_on_page_writeback(page);
4023 if (PageWriteback(page) ||
4024 !clear_page_dirty_for_io(page)) {
4029 ret = (*writepage)(page, wbc, data);
4031 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
4037 * done_index is set past this page,
4038 * so media errors will not choke
4039 * background writeout for the entire
4040 * file. This has consequences for
4041 * range_cyclic semantics (ie. it may
4042 * not be suitable for data integrity
4045 done_index = page->index + 1;
4051 * the filesystem may choose to bump up nr_to_write.
4052 * We have to make sure to honor the new nr_to_write
4055 nr_to_write_done = wbc->nr_to_write <= 0;
4057 pagevec_release(&pvec);
4060 if (!scanned && !done) {
4062 * We hit the last page and there is more work to be done: wrap
4063 * back to the start of the file
4070 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4071 mapping->writeback_index = done_index;
4073 btrfs_add_delayed_iput(inode);
4077 static void flush_epd_write_bio(struct extent_page_data *epd)
4082 bio_set_op_attrs(epd->bio, REQ_OP_WRITE,
4083 epd->sync_io ? REQ_SYNC : 0);
4085 ret = submit_one_bio(epd->bio, 0, epd->bio_flags);
4086 BUG_ON(ret < 0); /* -ENOMEM */
4091 static noinline void flush_write_bio(void *data)
4093 struct extent_page_data *epd = data;
4094 flush_epd_write_bio(epd);
4097 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
4098 get_extent_t *get_extent,
4099 struct writeback_control *wbc)
4102 struct extent_page_data epd = {
4105 .get_extent = get_extent,
4107 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4111 ret = __extent_writepage(page, wbc, &epd);
4113 flush_epd_write_bio(&epd);
4117 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
4118 u64 start, u64 end, get_extent_t *get_extent,
4122 struct address_space *mapping = inode->i_mapping;
4124 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4127 struct extent_page_data epd = {
4130 .get_extent = get_extent,
4132 .sync_io = mode == WB_SYNC_ALL,
4135 struct writeback_control wbc_writepages = {
4137 .nr_to_write = nr_pages * 2,
4138 .range_start = start,
4139 .range_end = end + 1,
4142 while (start <= end) {
4143 page = find_get_page(mapping, start >> PAGE_SHIFT);
4144 if (clear_page_dirty_for_io(page))
4145 ret = __extent_writepage(page, &wbc_writepages, &epd);
4147 if (tree->ops && tree->ops->writepage_end_io_hook)
4148 tree->ops->writepage_end_io_hook(page, start,
4149 start + PAGE_SIZE - 1,
4157 flush_epd_write_bio(&epd);
4161 int extent_writepages(struct extent_io_tree *tree,
4162 struct address_space *mapping,
4163 get_extent_t *get_extent,
4164 struct writeback_control *wbc)
4167 struct extent_page_data epd = {
4170 .get_extent = get_extent,
4172 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4176 ret = extent_write_cache_pages(tree, mapping, wbc,
4177 __extent_writepage, &epd,
4179 flush_epd_write_bio(&epd);
4183 int extent_readpages(struct extent_io_tree *tree,
4184 struct address_space *mapping,
4185 struct list_head *pages, unsigned nr_pages,
4186 get_extent_t get_extent)
4188 struct bio *bio = NULL;
4190 unsigned long bio_flags = 0;
4191 struct page *pagepool[16];
4193 struct extent_map *em_cached = NULL;
4195 u64 prev_em_start = (u64)-1;
4197 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
4198 page = list_entry(pages->prev, struct page, lru);
4200 prefetchw(&page->flags);
4201 list_del(&page->lru);
4202 if (add_to_page_cache_lru(page, mapping,
4204 readahead_gfp_mask(mapping))) {
4209 pagepool[nr++] = page;
4210 if (nr < ARRAY_SIZE(pagepool))
4212 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4213 &bio, 0, &bio_flags, &prev_em_start);
4217 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4218 &bio, 0, &bio_flags, &prev_em_start);
4221 free_extent_map(em_cached);
4223 BUG_ON(!list_empty(pages));
4225 return submit_one_bio(bio, 0, bio_flags);
4230 * basic invalidatepage code, this waits on any locked or writeback
4231 * ranges corresponding to the page, and then deletes any extent state
4232 * records from the tree
4234 int extent_invalidatepage(struct extent_io_tree *tree,
4235 struct page *page, unsigned long offset)
4237 struct extent_state *cached_state = NULL;
4238 u64 start = page_offset(page);
4239 u64 end = start + PAGE_SIZE - 1;
4240 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4242 start += ALIGN(offset, blocksize);
4246 lock_extent_bits(tree, start, end, &cached_state);
4247 wait_on_page_writeback(page);
4248 clear_extent_bit(tree, start, end,
4249 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
4250 EXTENT_DO_ACCOUNTING,
4251 1, 1, &cached_state, GFP_NOFS);
4256 * a helper for releasepage, this tests for areas of the page that
4257 * are locked or under IO and drops the related state bits if it is safe
4260 static int try_release_extent_state(struct extent_map_tree *map,
4261 struct extent_io_tree *tree,
4262 struct page *page, gfp_t mask)
4264 u64 start = page_offset(page);
4265 u64 end = start + PAGE_SIZE - 1;
4268 if (test_range_bit(tree, start, end,
4269 EXTENT_IOBITS, 0, NULL))
4273 * at this point we can safely clear everything except the
4274 * locked bit and the nodatasum bit
4276 ret = clear_extent_bit(tree, start, end,
4277 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4280 /* if clear_extent_bit failed for enomem reasons,
4281 * we can't allow the release to continue.
4292 * a helper for releasepage. As long as there are no locked extents
4293 * in the range corresponding to the page, both state records and extent
4294 * map records are removed
4296 int try_release_extent_mapping(struct extent_map_tree *map,
4297 struct extent_io_tree *tree, struct page *page,
4300 struct extent_map *em;
4301 u64 start = page_offset(page);
4302 u64 end = start + PAGE_SIZE - 1;
4304 if (gfpflags_allow_blocking(mask) &&
4305 page->mapping->host->i_size > SZ_16M) {
4307 while (start <= end) {
4308 len = end - start + 1;
4309 write_lock(&map->lock);
4310 em = lookup_extent_mapping(map, start, len);
4312 write_unlock(&map->lock);
4315 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4316 em->start != start) {
4317 write_unlock(&map->lock);
4318 free_extent_map(em);
4321 if (!test_range_bit(tree, em->start,
4322 extent_map_end(em) - 1,
4323 EXTENT_LOCKED | EXTENT_WRITEBACK,
4325 remove_extent_mapping(map, em);
4326 /* once for the rb tree */
4327 free_extent_map(em);
4329 start = extent_map_end(em);
4330 write_unlock(&map->lock);
4333 free_extent_map(em);
4336 return try_release_extent_state(map, tree, page, mask);
4340 * helper function for fiemap, which doesn't want to see any holes.
4341 * This maps until we find something past 'last'
4343 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4346 get_extent_t *get_extent)
4348 u64 sectorsize = btrfs_inode_sectorsize(inode);
4349 struct extent_map *em;
4356 len = last - offset;
4359 len = ALIGN(len, sectorsize);
4360 em = get_extent(inode, NULL, 0, offset, len, 0);
4361 if (IS_ERR_OR_NULL(em))
4364 /* if this isn't a hole return it */
4365 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
4366 em->block_start != EXTENT_MAP_HOLE) {
4370 /* this is a hole, advance to the next extent */
4371 offset = extent_map_end(em);
4372 free_extent_map(em);
4379 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4380 __u64 start, __u64 len, get_extent_t *get_extent)
4384 u64 max = start + len;
4388 u64 last_for_get_extent = 0;
4390 u64 isize = i_size_read(inode);
4391 struct btrfs_key found_key;
4392 struct extent_map *em = NULL;
4393 struct extent_state *cached_state = NULL;
4394 struct btrfs_path *path;
4395 struct btrfs_root *root = BTRFS_I(inode)->root;
4404 path = btrfs_alloc_path();
4407 path->leave_spinning = 1;
4409 start = round_down(start, btrfs_inode_sectorsize(inode));
4410 len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
4413 * lookup the last file extent. We're not using i_size here
4414 * because there might be preallocation past i_size
4416 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), -1,
4419 btrfs_free_path(path);
4428 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4429 found_type = found_key.type;
4431 /* No extents, but there might be delalloc bits */
4432 if (found_key.objectid != btrfs_ino(inode) ||
4433 found_type != BTRFS_EXTENT_DATA_KEY) {
4434 /* have to trust i_size as the end */
4436 last_for_get_extent = isize;
4439 * remember the start of the last extent. There are a
4440 * bunch of different factors that go into the length of the
4441 * extent, so its much less complex to remember where it started
4443 last = found_key.offset;
4444 last_for_get_extent = last + 1;
4446 btrfs_release_path(path);
4449 * we might have some extents allocated but more delalloc past those
4450 * extents. so, we trust isize unless the start of the last extent is
4455 last_for_get_extent = isize;
4458 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4461 em = get_extent_skip_holes(inode, start, last_for_get_extent,
4471 u64 offset_in_extent = 0;
4473 /* break if the extent we found is outside the range */
4474 if (em->start >= max || extent_map_end(em) < off)
4478 * get_extent may return an extent that starts before our
4479 * requested range. We have to make sure the ranges
4480 * we return to fiemap always move forward and don't
4481 * overlap, so adjust the offsets here
4483 em_start = max(em->start, off);
4486 * record the offset from the start of the extent
4487 * for adjusting the disk offset below. Only do this if the
4488 * extent isn't compressed since our in ram offset may be past
4489 * what we have actually allocated on disk.
4491 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4492 offset_in_extent = em_start - em->start;
4493 em_end = extent_map_end(em);
4494 em_len = em_end - em_start;
4499 * bump off for our next call to get_extent
4501 off = extent_map_end(em);
4505 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4507 flags |= FIEMAP_EXTENT_LAST;
4508 } else if (em->block_start == EXTENT_MAP_INLINE) {
4509 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4510 FIEMAP_EXTENT_NOT_ALIGNED);
4511 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4512 flags |= (FIEMAP_EXTENT_DELALLOC |
4513 FIEMAP_EXTENT_UNKNOWN);
4514 } else if (fieinfo->fi_extents_max) {
4515 struct btrfs_trans_handle *trans;
4517 u64 bytenr = em->block_start -
4518 (em->start - em->orig_start);
4520 disko = em->block_start + offset_in_extent;
4523 * We need a trans handle to get delayed refs
4525 trans = btrfs_join_transaction(root);
4527 * It's OK if we can't start a trans we can still check
4534 * As btrfs supports shared space, this information
4535 * can be exported to userspace tools via
4536 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4537 * then we're just getting a count and we can skip the
4540 ret = btrfs_check_shared(trans, root->fs_info,
4542 btrfs_ino(inode), bytenr);
4544 btrfs_end_transaction(trans);
4548 flags |= FIEMAP_EXTENT_SHARED;
4551 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4552 flags |= FIEMAP_EXTENT_ENCODED;
4553 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4554 flags |= FIEMAP_EXTENT_UNWRITTEN;
4556 free_extent_map(em);
4558 if ((em_start >= last) || em_len == (u64)-1 ||
4559 (last == (u64)-1 && isize <= em_end)) {
4560 flags |= FIEMAP_EXTENT_LAST;
4564 /* now scan forward to see if this is really the last extent. */
4565 em = get_extent_skip_holes(inode, off, last_for_get_extent,
4572 flags |= FIEMAP_EXTENT_LAST;
4575 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
4584 free_extent_map(em);
4586 btrfs_free_path(path);
4587 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4588 &cached_state, GFP_NOFS);
4592 static void __free_extent_buffer(struct extent_buffer *eb)
4594 btrfs_leak_debug_del(&eb->leak_list);
4595 kmem_cache_free(extent_buffer_cache, eb);
4598 int extent_buffer_under_io(struct extent_buffer *eb)
4600 return (atomic_read(&eb->io_pages) ||
4601 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4602 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4606 * Helper for releasing extent buffer page.
4608 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb)
4610 unsigned long index;
4612 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4614 BUG_ON(extent_buffer_under_io(eb));
4616 index = num_extent_pages(eb->start, eb->len);
4622 page = eb->pages[index];
4626 spin_lock(&page->mapping->private_lock);
4628 * We do this since we'll remove the pages after we've
4629 * removed the eb from the radix tree, so we could race
4630 * and have this page now attached to the new eb. So
4631 * only clear page_private if it's still connected to
4634 if (PagePrivate(page) &&
4635 page->private == (unsigned long)eb) {
4636 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4637 BUG_ON(PageDirty(page));
4638 BUG_ON(PageWriteback(page));
4640 * We need to make sure we haven't be attached
4643 ClearPagePrivate(page);
4644 set_page_private(page, 0);
4645 /* One for the page private */
4650 spin_unlock(&page->mapping->private_lock);
4652 /* One for when we allocated the page */
4654 } while (index != 0);
4658 * Helper for releasing the extent buffer.
4660 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4662 btrfs_release_extent_buffer_page(eb);
4663 __free_extent_buffer(eb);
4666 static struct extent_buffer *
4667 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4670 struct extent_buffer *eb = NULL;
4672 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4675 eb->fs_info = fs_info;
4677 rwlock_init(&eb->lock);
4678 atomic_set(&eb->write_locks, 0);
4679 atomic_set(&eb->read_locks, 0);
4680 atomic_set(&eb->blocking_readers, 0);
4681 atomic_set(&eb->blocking_writers, 0);
4682 atomic_set(&eb->spinning_readers, 0);
4683 atomic_set(&eb->spinning_writers, 0);
4684 eb->lock_nested = 0;
4685 init_waitqueue_head(&eb->write_lock_wq);
4686 init_waitqueue_head(&eb->read_lock_wq);
4688 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4690 spin_lock_init(&eb->refs_lock);
4691 atomic_set(&eb->refs, 1);
4692 atomic_set(&eb->io_pages, 0);
4695 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4697 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4698 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4699 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4704 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4708 struct extent_buffer *new;
4709 unsigned long num_pages = num_extent_pages(src->start, src->len);
4711 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
4715 for (i = 0; i < num_pages; i++) {
4716 p = alloc_page(GFP_NOFS);
4718 btrfs_release_extent_buffer(new);
4721 attach_extent_buffer_page(new, p);
4722 WARN_ON(PageDirty(p));
4725 copy_page(page_address(p), page_address(src->pages[i]));
4728 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4729 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4734 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4735 u64 start, unsigned long len)
4737 struct extent_buffer *eb;
4738 unsigned long num_pages;
4741 num_pages = num_extent_pages(start, len);
4743 eb = __alloc_extent_buffer(fs_info, start, len);
4747 for (i = 0; i < num_pages; i++) {
4748 eb->pages[i] = alloc_page(GFP_NOFS);
4752 set_extent_buffer_uptodate(eb);
4753 btrfs_set_header_nritems(eb, 0);
4754 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4759 __free_page(eb->pages[i - 1]);
4760 __free_extent_buffer(eb);
4764 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4767 return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
4770 static void check_buffer_tree_ref(struct extent_buffer *eb)
4773 /* the ref bit is tricky. We have to make sure it is set
4774 * if we have the buffer dirty. Otherwise the
4775 * code to free a buffer can end up dropping a dirty
4778 * Once the ref bit is set, it won't go away while the
4779 * buffer is dirty or in writeback, and it also won't
4780 * go away while we have the reference count on the
4783 * We can't just set the ref bit without bumping the
4784 * ref on the eb because free_extent_buffer might
4785 * see the ref bit and try to clear it. If this happens
4786 * free_extent_buffer might end up dropping our original
4787 * ref by mistake and freeing the page before we are able
4788 * to add one more ref.
4790 * So bump the ref count first, then set the bit. If someone
4791 * beat us to it, drop the ref we added.
4793 refs = atomic_read(&eb->refs);
4794 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4797 spin_lock(&eb->refs_lock);
4798 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4799 atomic_inc(&eb->refs);
4800 spin_unlock(&eb->refs_lock);
4803 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
4804 struct page *accessed)
4806 unsigned long num_pages, i;
4808 check_buffer_tree_ref(eb);
4810 num_pages = num_extent_pages(eb->start, eb->len);
4811 for (i = 0; i < num_pages; i++) {
4812 struct page *p = eb->pages[i];
4815 mark_page_accessed(p);
4819 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
4822 struct extent_buffer *eb;
4825 eb = radix_tree_lookup(&fs_info->buffer_radix,
4826 start >> PAGE_SHIFT);
4827 if (eb && atomic_inc_not_zero(&eb->refs)) {
4830 * Lock our eb's refs_lock to avoid races with
4831 * free_extent_buffer. When we get our eb it might be flagged
4832 * with EXTENT_BUFFER_STALE and another task running
4833 * free_extent_buffer might have seen that flag set,
4834 * eb->refs == 2, that the buffer isn't under IO (dirty and
4835 * writeback flags not set) and it's still in the tree (flag
4836 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4837 * of decrementing the extent buffer's reference count twice.
4838 * So here we could race and increment the eb's reference count,
4839 * clear its stale flag, mark it as dirty and drop our reference
4840 * before the other task finishes executing free_extent_buffer,
4841 * which would later result in an attempt to free an extent
4842 * buffer that is dirty.
4844 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
4845 spin_lock(&eb->refs_lock);
4846 spin_unlock(&eb->refs_lock);
4848 mark_extent_buffer_accessed(eb, NULL);
4856 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4857 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
4860 struct extent_buffer *eb, *exists = NULL;
4863 eb = find_extent_buffer(fs_info, start);
4866 eb = alloc_dummy_extent_buffer(fs_info, start);
4869 eb->fs_info = fs_info;
4871 ret = radix_tree_preload(GFP_NOFS);
4874 spin_lock(&fs_info->buffer_lock);
4875 ret = radix_tree_insert(&fs_info->buffer_radix,
4876 start >> PAGE_SHIFT, eb);
4877 spin_unlock(&fs_info->buffer_lock);
4878 radix_tree_preload_end();
4879 if (ret == -EEXIST) {
4880 exists = find_extent_buffer(fs_info, start);
4886 check_buffer_tree_ref(eb);
4887 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4890 * We will free dummy extent buffer's if they come into
4891 * free_extent_buffer with a ref count of 2, but if we are using this we
4892 * want the buffers to stay in memory until we're done with them, so
4893 * bump the ref count again.
4895 atomic_inc(&eb->refs);
4898 btrfs_release_extent_buffer(eb);
4903 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
4906 unsigned long len = fs_info->nodesize;
4907 unsigned long num_pages = num_extent_pages(start, len);
4909 unsigned long index = start >> PAGE_SHIFT;
4910 struct extent_buffer *eb;
4911 struct extent_buffer *exists = NULL;
4913 struct address_space *mapping = fs_info->btree_inode->i_mapping;
4917 if (!IS_ALIGNED(start, fs_info->sectorsize)) {
4918 btrfs_err(fs_info, "bad tree block start %llu", start);
4919 return ERR_PTR(-EINVAL);
4922 eb = find_extent_buffer(fs_info, start);
4926 eb = __alloc_extent_buffer(fs_info, start, len);
4928 return ERR_PTR(-ENOMEM);
4930 for (i = 0; i < num_pages; i++, index++) {
4931 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
4933 exists = ERR_PTR(-ENOMEM);
4937 spin_lock(&mapping->private_lock);
4938 if (PagePrivate(p)) {
4940 * We could have already allocated an eb for this page
4941 * and attached one so lets see if we can get a ref on
4942 * the existing eb, and if we can we know it's good and
4943 * we can just return that one, else we know we can just
4944 * overwrite page->private.
4946 exists = (struct extent_buffer *)p->private;
4947 if (atomic_inc_not_zero(&exists->refs)) {
4948 spin_unlock(&mapping->private_lock);
4951 mark_extent_buffer_accessed(exists, p);
4957 * Do this so attach doesn't complain and we need to
4958 * drop the ref the old guy had.
4960 ClearPagePrivate(p);
4961 WARN_ON(PageDirty(p));
4964 attach_extent_buffer_page(eb, p);
4965 spin_unlock(&mapping->private_lock);
4966 WARN_ON(PageDirty(p));
4968 if (!PageUptodate(p))
4972 * see below about how we avoid a nasty race with release page
4973 * and why we unlock later
4977 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4979 ret = radix_tree_preload(GFP_NOFS);
4981 exists = ERR_PTR(ret);
4985 spin_lock(&fs_info->buffer_lock);
4986 ret = radix_tree_insert(&fs_info->buffer_radix,
4987 start >> PAGE_SHIFT, eb);
4988 spin_unlock(&fs_info->buffer_lock);
4989 radix_tree_preload_end();
4990 if (ret == -EEXIST) {
4991 exists = find_extent_buffer(fs_info, start);
4997 /* add one reference for the tree */
4998 check_buffer_tree_ref(eb);
4999 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5002 * there is a race where release page may have
5003 * tried to find this extent buffer in the radix
5004 * but failed. It will tell the VM it is safe to
5005 * reclaim the, and it will clear the page private bit.
5006 * We must make sure to set the page private bit properly
5007 * after the extent buffer is in the radix tree so
5008 * it doesn't get lost
5010 SetPageChecked(eb->pages[0]);
5011 for (i = 1; i < num_pages; i++) {
5013 ClearPageChecked(p);
5016 unlock_page(eb->pages[0]);
5020 WARN_ON(!atomic_dec_and_test(&eb->refs));
5021 for (i = 0; i < num_pages; i++) {
5023 unlock_page(eb->pages[i]);
5026 btrfs_release_extent_buffer(eb);
5030 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5032 struct extent_buffer *eb =
5033 container_of(head, struct extent_buffer, rcu_head);
5035 __free_extent_buffer(eb);
5038 /* Expects to have eb->eb_lock already held */
5039 static int release_extent_buffer(struct extent_buffer *eb)
5041 WARN_ON(atomic_read(&eb->refs) == 0);
5042 if (atomic_dec_and_test(&eb->refs)) {
5043 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5044 struct btrfs_fs_info *fs_info = eb->fs_info;
5046 spin_unlock(&eb->refs_lock);
5048 spin_lock(&fs_info->buffer_lock);
5049 radix_tree_delete(&fs_info->buffer_radix,
5050 eb->start >> PAGE_SHIFT);
5051 spin_unlock(&fs_info->buffer_lock);
5053 spin_unlock(&eb->refs_lock);
5056 /* Should be safe to release our pages at this point */
5057 btrfs_release_extent_buffer_page(eb);
5058 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5059 if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) {
5060 __free_extent_buffer(eb);
5064 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5067 spin_unlock(&eb->refs_lock);
5072 void free_extent_buffer(struct extent_buffer *eb)
5080 refs = atomic_read(&eb->refs);
5083 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5088 spin_lock(&eb->refs_lock);
5089 if (atomic_read(&eb->refs) == 2 &&
5090 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
5091 atomic_dec(&eb->refs);
5093 if (atomic_read(&eb->refs) == 2 &&
5094 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5095 !extent_buffer_under_io(eb) &&
5096 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5097 atomic_dec(&eb->refs);
5100 * I know this is terrible, but it's temporary until we stop tracking
5101 * the uptodate bits and such for the extent buffers.
5103 release_extent_buffer(eb);
5106 void free_extent_buffer_stale(struct extent_buffer *eb)
5111 spin_lock(&eb->refs_lock);
5112 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5114 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5115 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5116 atomic_dec(&eb->refs);
5117 release_extent_buffer(eb);
5120 void clear_extent_buffer_dirty(struct extent_buffer *eb)
5123 unsigned long num_pages;
5126 num_pages = num_extent_pages(eb->start, eb->len);
5128 for (i = 0; i < num_pages; i++) {
5129 page = eb->pages[i];
5130 if (!PageDirty(page))
5134 WARN_ON(!PagePrivate(page));
5136 clear_page_dirty_for_io(page);
5137 spin_lock_irq(&page->mapping->tree_lock);
5138 if (!PageDirty(page)) {
5139 radix_tree_tag_clear(&page->mapping->page_tree,
5141 PAGECACHE_TAG_DIRTY);
5143 spin_unlock_irq(&page->mapping->tree_lock);
5144 ClearPageError(page);
5147 WARN_ON(atomic_read(&eb->refs) == 0);
5150 int set_extent_buffer_dirty(struct extent_buffer *eb)
5153 unsigned long num_pages;
5156 check_buffer_tree_ref(eb);
5158 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5160 num_pages = num_extent_pages(eb->start, eb->len);
5161 WARN_ON(atomic_read(&eb->refs) == 0);
5162 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5164 for (i = 0; i < num_pages; i++)
5165 set_page_dirty(eb->pages[i]);
5169 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5173 unsigned long num_pages;
5175 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5176 num_pages = num_extent_pages(eb->start, eb->len);
5177 for (i = 0; i < num_pages; i++) {
5178 page = eb->pages[i];
5180 ClearPageUptodate(page);
5184 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5188 unsigned long num_pages;
5190 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5191 num_pages = num_extent_pages(eb->start, eb->len);
5192 for (i = 0; i < num_pages; i++) {
5193 page = eb->pages[i];
5194 SetPageUptodate(page);
5198 int extent_buffer_uptodate(struct extent_buffer *eb)
5200 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5203 int read_extent_buffer_pages(struct extent_io_tree *tree,
5204 struct extent_buffer *eb, int wait,
5205 get_extent_t *get_extent, int mirror_num)
5211 int locked_pages = 0;
5212 int all_uptodate = 1;
5213 unsigned long num_pages;
5214 unsigned long num_reads = 0;
5215 struct bio *bio = NULL;
5216 unsigned long bio_flags = 0;
5218 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5221 num_pages = num_extent_pages(eb->start, eb->len);
5222 for (i = 0; i < num_pages; i++) {
5223 page = eb->pages[i];
5224 if (wait == WAIT_NONE) {
5225 if (!trylock_page(page))
5233 * We need to firstly lock all pages to make sure that
5234 * the uptodate bit of our pages won't be affected by
5235 * clear_extent_buffer_uptodate().
5237 for (i = 0; i < num_pages; i++) {
5238 page = eb->pages[i];
5239 if (!PageUptodate(page)) {
5246 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5250 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5251 eb->read_mirror = 0;
5252 atomic_set(&eb->io_pages, num_reads);
5253 for (i = 0; i < num_pages; i++) {
5254 page = eb->pages[i];
5256 if (!PageUptodate(page)) {
5258 atomic_dec(&eb->io_pages);
5263 ClearPageError(page);
5264 err = __extent_read_full_page(tree, page,
5266 mirror_num, &bio_flags,
5271 * We use &bio in above __extent_read_full_page,
5272 * so we ensure that if it returns error, the
5273 * current page fails to add itself to bio and
5274 * it's been unlocked.
5276 * We must dec io_pages by ourselves.
5278 atomic_dec(&eb->io_pages);
5286 err = submit_one_bio(bio, mirror_num, bio_flags);
5291 if (ret || wait != WAIT_COMPLETE)
5294 for (i = 0; i < num_pages; i++) {
5295 page = eb->pages[i];
5296 wait_on_page_locked(page);
5297 if (!PageUptodate(page))
5304 while (locked_pages > 0) {
5306 page = eb->pages[locked_pages];
5312 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
5313 unsigned long start,
5320 char *dst = (char *)dstv;
5321 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5322 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5324 WARN_ON(start > eb->len);
5325 WARN_ON(start + len > eb->start + eb->len);
5327 offset = (start_offset + start) & (PAGE_SIZE - 1);
5330 page = eb->pages[i];
5332 cur = min(len, (PAGE_SIZE - offset));
5333 kaddr = page_address(page);
5334 memcpy(dst, kaddr + offset, cur);
5343 int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv,
5344 unsigned long start,
5351 char __user *dst = (char __user *)dstv;
5352 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5353 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5356 WARN_ON(start > eb->len);
5357 WARN_ON(start + len > eb->start + eb->len);
5359 offset = (start_offset + start) & (PAGE_SIZE - 1);
5362 page = eb->pages[i];
5364 cur = min(len, (PAGE_SIZE - offset));
5365 kaddr = page_address(page);
5366 if (copy_to_user(dst, kaddr + offset, cur)) {
5381 * return 0 if the item is found within a page.
5382 * return 1 if the item spans two pages.
5383 * return -EINVAL otherwise.
5385 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
5386 unsigned long min_len, char **map,
5387 unsigned long *map_start,
5388 unsigned long *map_len)
5390 size_t offset = start & (PAGE_SIZE - 1);
5393 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5394 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5395 unsigned long end_i = (start_offset + start + min_len - 1) >>
5402 offset = start_offset;
5406 *map_start = ((u64)i << PAGE_SHIFT) - start_offset;
5409 if (start + min_len > eb->len) {
5410 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5411 eb->start, eb->len, start, min_len);
5416 kaddr = page_address(p);
5417 *map = kaddr + offset;
5418 *map_len = PAGE_SIZE - offset;
5422 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
5423 unsigned long start,
5430 char *ptr = (char *)ptrv;
5431 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5432 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5435 WARN_ON(start > eb->len);
5436 WARN_ON(start + len > eb->start + eb->len);
5438 offset = (start_offset + start) & (PAGE_SIZE - 1);
5441 page = eb->pages[i];
5443 cur = min(len, (PAGE_SIZE - offset));
5445 kaddr = page_address(page);
5446 ret = memcmp(ptr, kaddr + offset, cur);
5458 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
5463 WARN_ON(!PageUptodate(eb->pages[0]));
5464 kaddr = page_address(eb->pages[0]);
5465 memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
5469 void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)
5473 WARN_ON(!PageUptodate(eb->pages[0]));
5474 kaddr = page_address(eb->pages[0]);
5475 memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
5479 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
5480 unsigned long start, unsigned long len)
5486 char *src = (char *)srcv;
5487 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5488 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5490 WARN_ON(start > eb->len);
5491 WARN_ON(start + len > eb->start + eb->len);
5493 offset = (start_offset + start) & (PAGE_SIZE - 1);
5496 page = eb->pages[i];
5497 WARN_ON(!PageUptodate(page));
5499 cur = min(len, PAGE_SIZE - offset);
5500 kaddr = page_address(page);
5501 memcpy(kaddr + offset, src, cur);
5510 void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
5517 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5518 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5520 WARN_ON(start > eb->len);
5521 WARN_ON(start + len > eb->start + eb->len);
5523 offset = (start_offset + start) & (PAGE_SIZE - 1);
5526 page = eb->pages[i];
5527 WARN_ON(!PageUptodate(page));
5529 cur = min(len, PAGE_SIZE - offset);
5530 kaddr = page_address(page);
5531 memset(kaddr + offset, 0, cur);
5539 void copy_extent_buffer_full(struct extent_buffer *dst,
5540 struct extent_buffer *src)
5545 ASSERT(dst->len == src->len);
5547 num_pages = num_extent_pages(dst->start, dst->len);
5548 for (i = 0; i < num_pages; i++)
5549 copy_page(page_address(dst->pages[i]),
5550 page_address(src->pages[i]));
5553 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5554 unsigned long dst_offset, unsigned long src_offset,
5557 u64 dst_len = dst->len;
5562 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5563 unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
5565 WARN_ON(src->len != dst_len);
5567 offset = (start_offset + dst_offset) &
5571 page = dst->pages[i];
5572 WARN_ON(!PageUptodate(page));
5574 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5576 kaddr = page_address(page);
5577 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5586 void le_bitmap_set(u8 *map, unsigned int start, int len)
5588 u8 *p = map + BIT_BYTE(start);
5589 const unsigned int size = start + len;
5590 int bits_to_set = BITS_PER_BYTE - (start % BITS_PER_BYTE);
5591 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(start);
5593 while (len - bits_to_set >= 0) {
5596 bits_to_set = BITS_PER_BYTE;
5601 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5606 void le_bitmap_clear(u8 *map, unsigned int start, int len)
5608 u8 *p = map + BIT_BYTE(start);
5609 const unsigned int size = start + len;
5610 int bits_to_clear = BITS_PER_BYTE - (start % BITS_PER_BYTE);
5611 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(start);
5613 while (len - bits_to_clear >= 0) {
5614 *p &= ~mask_to_clear;
5615 len -= bits_to_clear;
5616 bits_to_clear = BITS_PER_BYTE;
5621 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5622 *p &= ~mask_to_clear;
5627 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5629 * @eb: the extent buffer
5630 * @start: offset of the bitmap item in the extent buffer
5632 * @page_index: return index of the page in the extent buffer that contains the
5634 * @page_offset: return offset into the page given by page_index
5636 * This helper hides the ugliness of finding the byte in an extent buffer which
5637 * contains a given bit.
5639 static inline void eb_bitmap_offset(struct extent_buffer *eb,
5640 unsigned long start, unsigned long nr,
5641 unsigned long *page_index,
5642 size_t *page_offset)
5644 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5645 size_t byte_offset = BIT_BYTE(nr);
5649 * The byte we want is the offset of the extent buffer + the offset of
5650 * the bitmap item in the extent buffer + the offset of the byte in the
5653 offset = start_offset + start + byte_offset;
5655 *page_index = offset >> PAGE_SHIFT;
5656 *page_offset = offset & (PAGE_SIZE - 1);
5660 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5661 * @eb: the extent buffer
5662 * @start: offset of the bitmap item in the extent buffer
5663 * @nr: bit number to test
5665 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
5673 eb_bitmap_offset(eb, start, nr, &i, &offset);
5674 page = eb->pages[i];
5675 WARN_ON(!PageUptodate(page));
5676 kaddr = page_address(page);
5677 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5681 * extent_buffer_bitmap_set - set an area of a bitmap
5682 * @eb: the extent buffer
5683 * @start: offset of the bitmap item in the extent buffer
5684 * @pos: bit number of the first bit
5685 * @len: number of bits to set
5687 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
5688 unsigned long pos, unsigned long len)
5694 const unsigned int size = pos + len;
5695 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5696 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5698 eb_bitmap_offset(eb, start, pos, &i, &offset);
5699 page = eb->pages[i];
5700 WARN_ON(!PageUptodate(page));
5701 kaddr = page_address(page);
5703 while (len >= bits_to_set) {
5704 kaddr[offset] |= mask_to_set;
5706 bits_to_set = BITS_PER_BYTE;
5708 if (++offset >= PAGE_SIZE && len > 0) {
5710 page = eb->pages[++i];
5711 WARN_ON(!PageUptodate(page));
5712 kaddr = page_address(page);
5716 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5717 kaddr[offset] |= mask_to_set;
5723 * extent_buffer_bitmap_clear - clear an area of a bitmap
5724 * @eb: the extent buffer
5725 * @start: offset of the bitmap item in the extent buffer
5726 * @pos: bit number of the first bit
5727 * @len: number of bits to clear
5729 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
5730 unsigned long pos, unsigned long len)
5736 const unsigned int size = pos + len;
5737 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5738 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5740 eb_bitmap_offset(eb, start, pos, &i, &offset);
5741 page = eb->pages[i];
5742 WARN_ON(!PageUptodate(page));
5743 kaddr = page_address(page);
5745 while (len >= bits_to_clear) {
5746 kaddr[offset] &= ~mask_to_clear;
5747 len -= bits_to_clear;
5748 bits_to_clear = BITS_PER_BYTE;
5750 if (++offset >= PAGE_SIZE && len > 0) {
5752 page = eb->pages[++i];
5753 WARN_ON(!PageUptodate(page));
5754 kaddr = page_address(page);
5758 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5759 kaddr[offset] &= ~mask_to_clear;
5763 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5765 unsigned long distance = (src > dst) ? src - dst : dst - src;
5766 return distance < len;
5769 static void copy_pages(struct page *dst_page, struct page *src_page,
5770 unsigned long dst_off, unsigned long src_off,
5773 char *dst_kaddr = page_address(dst_page);
5775 int must_memmove = 0;
5777 if (dst_page != src_page) {
5778 src_kaddr = page_address(src_page);
5780 src_kaddr = dst_kaddr;
5781 if (areas_overlap(src_off, dst_off, len))
5786 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5788 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5791 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5792 unsigned long src_offset, unsigned long len)
5794 struct btrfs_fs_info *fs_info = dst->fs_info;
5796 size_t dst_off_in_page;
5797 size_t src_off_in_page;
5798 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5799 unsigned long dst_i;
5800 unsigned long src_i;
5802 if (src_offset + len > dst->len) {
5804 "memmove bogus src_offset %lu move len %lu dst len %lu",
5805 src_offset, len, dst->len);
5808 if (dst_offset + len > dst->len) {
5810 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5811 dst_offset, len, dst->len);
5816 dst_off_in_page = (start_offset + dst_offset) &
5818 src_off_in_page = (start_offset + src_offset) &
5821 dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
5822 src_i = (start_offset + src_offset) >> PAGE_SHIFT;
5824 cur = min(len, (unsigned long)(PAGE_SIZE -
5826 cur = min_t(unsigned long, cur,
5827 (unsigned long)(PAGE_SIZE - dst_off_in_page));
5829 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5830 dst_off_in_page, src_off_in_page, cur);
5838 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5839 unsigned long src_offset, unsigned long len)
5841 struct btrfs_fs_info *fs_info = dst->fs_info;
5843 size_t dst_off_in_page;
5844 size_t src_off_in_page;
5845 unsigned long dst_end = dst_offset + len - 1;
5846 unsigned long src_end = src_offset + len - 1;
5847 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5848 unsigned long dst_i;
5849 unsigned long src_i;
5851 if (src_offset + len > dst->len) {
5853 "memmove bogus src_offset %lu move len %lu len %lu",
5854 src_offset, len, dst->len);
5857 if (dst_offset + len > dst->len) {
5859 "memmove bogus dst_offset %lu move len %lu len %lu",
5860 dst_offset, len, dst->len);
5863 if (dst_offset < src_offset) {
5864 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5868 dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
5869 src_i = (start_offset + src_end) >> PAGE_SHIFT;
5871 dst_off_in_page = (start_offset + dst_end) &
5873 src_off_in_page = (start_offset + src_end) &
5876 cur = min_t(unsigned long, len, src_off_in_page + 1);
5877 cur = min(cur, dst_off_in_page + 1);
5878 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5879 dst_off_in_page - cur + 1,
5880 src_off_in_page - cur + 1, cur);
5888 int try_release_extent_buffer(struct page *page)
5890 struct extent_buffer *eb;
5893 * We need to make sure nobody is attaching this page to an eb right
5896 spin_lock(&page->mapping->private_lock);
5897 if (!PagePrivate(page)) {
5898 spin_unlock(&page->mapping->private_lock);
5902 eb = (struct extent_buffer *)page->private;
5906 * This is a little awful but should be ok, we need to make sure that
5907 * the eb doesn't disappear out from under us while we're looking at
5910 spin_lock(&eb->refs_lock);
5911 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5912 spin_unlock(&eb->refs_lock);
5913 spin_unlock(&page->mapping->private_lock);
5916 spin_unlock(&page->mapping->private_lock);
5919 * If tree ref isn't set then we know the ref on this eb is a real ref,
5920 * so just return, this page will likely be freed soon anyway.
5922 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5923 spin_unlock(&eb->refs_lock);
5927 return release_extent_buffer(eb);