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(BTRFS_I(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 int __process_pages_contig(struct address_space *mapping,
1558 struct page *locked_page,
1559 pgoff_t start_index, pgoff_t end_index,
1560 unsigned long page_ops, pgoff_t *index_ret);
1562 static noinline void __unlock_for_delalloc(struct inode *inode,
1563 struct page *locked_page,
1566 unsigned long index = start >> PAGE_SHIFT;
1567 unsigned long end_index = end >> PAGE_SHIFT;
1569 ASSERT(locked_page);
1570 if (index == locked_page->index && end_index == index)
1573 __process_pages_contig(inode->i_mapping, locked_page, index, end_index,
1577 static noinline int lock_delalloc_pages(struct inode *inode,
1578 struct page *locked_page,
1582 unsigned long index = delalloc_start >> PAGE_SHIFT;
1583 unsigned long index_ret = index;
1584 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1587 ASSERT(locked_page);
1588 if (index == locked_page->index && index == end_index)
1591 ret = __process_pages_contig(inode->i_mapping, locked_page, index,
1592 end_index, PAGE_LOCK, &index_ret);
1594 __unlock_for_delalloc(inode, locked_page, delalloc_start,
1595 (u64)index_ret << PAGE_SHIFT);
1600 * find a contiguous range of bytes in the file marked as delalloc, not
1601 * more than 'max_bytes'. start and end are used to return the range,
1603 * 1 is returned if we find something, 0 if nothing was in the tree
1605 STATIC u64 find_lock_delalloc_range(struct inode *inode,
1606 struct extent_io_tree *tree,
1607 struct page *locked_page, u64 *start,
1608 u64 *end, u64 max_bytes)
1613 struct extent_state *cached_state = NULL;
1618 /* step one, find a bunch of delalloc bytes starting at start */
1619 delalloc_start = *start;
1621 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1622 max_bytes, &cached_state);
1623 if (!found || delalloc_end <= *start) {
1624 *start = delalloc_start;
1625 *end = delalloc_end;
1626 free_extent_state(cached_state);
1631 * start comes from the offset of locked_page. We have to lock
1632 * pages in order, so we can't process delalloc bytes before
1635 if (delalloc_start < *start)
1636 delalloc_start = *start;
1639 * make sure to limit the number of pages we try to lock down
1641 if (delalloc_end + 1 - delalloc_start > max_bytes)
1642 delalloc_end = delalloc_start + max_bytes - 1;
1644 /* step two, lock all the pages after the page that has start */
1645 ret = lock_delalloc_pages(inode, locked_page,
1646 delalloc_start, delalloc_end);
1647 if (ret == -EAGAIN) {
1648 /* some of the pages are gone, lets avoid looping by
1649 * shortening the size of the delalloc range we're searching
1651 free_extent_state(cached_state);
1652 cached_state = NULL;
1654 max_bytes = PAGE_SIZE;
1662 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1664 /* step three, lock the state bits for the whole range */
1665 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1667 /* then test to make sure it is all still delalloc */
1668 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1669 EXTENT_DELALLOC, 1, cached_state);
1671 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1672 &cached_state, GFP_NOFS);
1673 __unlock_for_delalloc(inode, locked_page,
1674 delalloc_start, delalloc_end);
1678 free_extent_state(cached_state);
1679 *start = delalloc_start;
1680 *end = delalloc_end;
1685 static int __process_pages_contig(struct address_space *mapping,
1686 struct page *locked_page,
1687 pgoff_t start_index, pgoff_t end_index,
1688 unsigned long page_ops, pgoff_t *index_ret)
1690 unsigned long nr_pages = end_index - start_index + 1;
1691 unsigned long pages_locked = 0;
1692 pgoff_t index = start_index;
1693 struct page *pages[16];
1698 if (page_ops & PAGE_LOCK) {
1699 ASSERT(page_ops == PAGE_LOCK);
1700 ASSERT(index_ret && *index_ret == start_index);
1703 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1704 mapping_set_error(mapping, -EIO);
1706 while (nr_pages > 0) {
1707 ret = find_get_pages_contig(mapping, index,
1708 min_t(unsigned long,
1709 nr_pages, ARRAY_SIZE(pages)), pages);
1712 * Only if we're going to lock these pages,
1713 * can we find nothing at @index.
1715 ASSERT(page_ops & PAGE_LOCK);
1719 for (i = 0; i < ret; i++) {
1720 if (page_ops & PAGE_SET_PRIVATE2)
1721 SetPagePrivate2(pages[i]);
1723 if (pages[i] == locked_page) {
1728 if (page_ops & PAGE_CLEAR_DIRTY)
1729 clear_page_dirty_for_io(pages[i]);
1730 if (page_ops & PAGE_SET_WRITEBACK)
1731 set_page_writeback(pages[i]);
1732 if (page_ops & PAGE_SET_ERROR)
1733 SetPageError(pages[i]);
1734 if (page_ops & PAGE_END_WRITEBACK)
1735 end_page_writeback(pages[i]);
1736 if (page_ops & PAGE_UNLOCK)
1737 unlock_page(pages[i]);
1738 if (page_ops & PAGE_LOCK) {
1739 lock_page(pages[i]);
1740 if (!PageDirty(pages[i]) ||
1741 pages[i]->mapping != mapping) {
1742 unlock_page(pages[i]);
1756 if (err && index_ret)
1757 *index_ret = start_index + pages_locked - 1;
1761 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1762 u64 delalloc_end, struct page *locked_page,
1763 unsigned clear_bits,
1764 unsigned long page_ops)
1766 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0,
1769 __process_pages_contig(inode->i_mapping, locked_page,
1770 start >> PAGE_SHIFT, end >> PAGE_SHIFT,
1775 * count the number of bytes in the tree that have a given bit(s)
1776 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1777 * cached. The total number found is returned.
1779 u64 count_range_bits(struct extent_io_tree *tree,
1780 u64 *start, u64 search_end, u64 max_bytes,
1781 unsigned bits, int contig)
1783 struct rb_node *node;
1784 struct extent_state *state;
1785 u64 cur_start = *start;
1786 u64 total_bytes = 0;
1790 if (WARN_ON(search_end <= cur_start))
1793 spin_lock(&tree->lock);
1794 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1795 total_bytes = tree->dirty_bytes;
1799 * this search will find all the extents that end after
1802 node = tree_search(tree, cur_start);
1807 state = rb_entry(node, struct extent_state, rb_node);
1808 if (state->start > search_end)
1810 if (contig && found && state->start > last + 1)
1812 if (state->end >= cur_start && (state->state & bits) == bits) {
1813 total_bytes += min(search_end, state->end) + 1 -
1814 max(cur_start, state->start);
1815 if (total_bytes >= max_bytes)
1818 *start = max(cur_start, state->start);
1822 } else if (contig && found) {
1825 node = rb_next(node);
1830 spin_unlock(&tree->lock);
1835 * set the private field for a given byte offset in the tree. If there isn't
1836 * an extent_state there already, this does nothing.
1838 static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start,
1839 struct io_failure_record *failrec)
1841 struct rb_node *node;
1842 struct extent_state *state;
1845 spin_lock(&tree->lock);
1847 * this search will find all the extents that end after
1850 node = tree_search(tree, start);
1855 state = rb_entry(node, struct extent_state, rb_node);
1856 if (state->start != start) {
1860 state->failrec = failrec;
1862 spin_unlock(&tree->lock);
1866 static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start,
1867 struct io_failure_record **failrec)
1869 struct rb_node *node;
1870 struct extent_state *state;
1873 spin_lock(&tree->lock);
1875 * this search will find all the extents that end after
1878 node = tree_search(tree, start);
1883 state = rb_entry(node, struct extent_state, rb_node);
1884 if (state->start != start) {
1888 *failrec = state->failrec;
1890 spin_unlock(&tree->lock);
1895 * searches a range in the state tree for a given mask.
1896 * If 'filled' == 1, this returns 1 only if every extent in the tree
1897 * has the bits set. Otherwise, 1 is returned if any bit in the
1898 * range is found set.
1900 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1901 unsigned bits, int filled, struct extent_state *cached)
1903 struct extent_state *state = NULL;
1904 struct rb_node *node;
1907 spin_lock(&tree->lock);
1908 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
1909 cached->end > start)
1910 node = &cached->rb_node;
1912 node = tree_search(tree, start);
1913 while (node && start <= end) {
1914 state = rb_entry(node, struct extent_state, rb_node);
1916 if (filled && state->start > start) {
1921 if (state->start > end)
1924 if (state->state & bits) {
1928 } else if (filled) {
1933 if (state->end == (u64)-1)
1936 start = state->end + 1;
1939 node = rb_next(node);
1946 spin_unlock(&tree->lock);
1951 * helper function to set a given page up to date if all the
1952 * extents in the tree for that page are up to date
1954 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1956 u64 start = page_offset(page);
1957 u64 end = start + PAGE_SIZE - 1;
1958 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1959 SetPageUptodate(page);
1962 int free_io_failure(struct inode *inode, struct io_failure_record *rec)
1966 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1968 set_state_failrec(failure_tree, rec->start, NULL);
1969 ret = clear_extent_bits(failure_tree, rec->start,
1970 rec->start + rec->len - 1,
1971 EXTENT_LOCKED | EXTENT_DIRTY);
1975 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1976 rec->start + rec->len - 1,
1986 * this bypasses the standard btrfs submit functions deliberately, as
1987 * the standard behavior is to write all copies in a raid setup. here we only
1988 * want to write the one bad copy. so we do the mapping for ourselves and issue
1989 * submit_bio directly.
1990 * to avoid any synchronization issues, wait for the data after writing, which
1991 * actually prevents the read that triggered the error from finishing.
1992 * currently, there can be no more than two copies of every data bit. thus,
1993 * exactly one rewrite is required.
1995 int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical,
1996 struct page *page, unsigned int pg_offset, int mirror_num)
1998 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2000 struct btrfs_device *dev;
2003 struct btrfs_bio *bbio = NULL;
2004 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
2007 ASSERT(!(fs_info->sb->s_flags & MS_RDONLY));
2008 BUG_ON(!mirror_num);
2010 /* we can't repair anything in raid56 yet */
2011 if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num))
2014 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2017 bio->bi_iter.bi_size = 0;
2018 map_length = length;
2021 * Avoid races with device replace and make sure our bbio has devices
2022 * associated to its stripes that don't go away while we are doing the
2023 * read repair operation.
2025 btrfs_bio_counter_inc_blocked(fs_info);
2026 ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
2027 &map_length, &bbio, mirror_num);
2029 btrfs_bio_counter_dec(fs_info);
2033 BUG_ON(mirror_num != bbio->mirror_num);
2034 sector = bbio->stripes[mirror_num-1].physical >> 9;
2035 bio->bi_iter.bi_sector = sector;
2036 dev = bbio->stripes[mirror_num-1].dev;
2037 btrfs_put_bbio(bbio);
2038 if (!dev || !dev->bdev || !dev->writeable) {
2039 btrfs_bio_counter_dec(fs_info);
2043 bio->bi_bdev = dev->bdev;
2044 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
2045 bio_add_page(bio, page, length, pg_offset);
2047 if (btrfsic_submit_bio_wait(bio)) {
2048 /* try to remap that extent elsewhere? */
2049 btrfs_bio_counter_dec(fs_info);
2051 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2055 btrfs_info_rl_in_rcu(fs_info,
2056 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2057 btrfs_ino(BTRFS_I(inode)), start,
2058 rcu_str_deref(dev->name), sector);
2059 btrfs_bio_counter_dec(fs_info);
2064 int repair_eb_io_failure(struct btrfs_fs_info *fs_info,
2065 struct extent_buffer *eb, int mirror_num)
2067 u64 start = eb->start;
2068 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
2071 if (fs_info->sb->s_flags & MS_RDONLY)
2074 for (i = 0; i < num_pages; i++) {
2075 struct page *p = eb->pages[i];
2077 ret = repair_io_failure(fs_info->btree_inode, start,
2078 PAGE_SIZE, start, p,
2079 start - page_offset(p), mirror_num);
2089 * each time an IO finishes, we do a fast check in the IO failure tree
2090 * to see if we need to process or clean up an io_failure_record
2092 int clean_io_failure(struct inode *inode, u64 start, struct page *page,
2093 unsigned int pg_offset)
2096 struct io_failure_record *failrec;
2097 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2098 struct extent_state *state;
2103 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
2104 (u64)-1, 1, EXTENT_DIRTY, 0);
2108 ret = get_state_failrec(&BTRFS_I(inode)->io_failure_tree, start,
2113 BUG_ON(!failrec->this_mirror);
2115 if (failrec->in_validation) {
2116 /* there was no real error, just free the record */
2117 btrfs_debug(fs_info,
2118 "clean_io_failure: freeing dummy error at %llu",
2122 if (fs_info->sb->s_flags & MS_RDONLY)
2125 spin_lock(&BTRFS_I(inode)->io_tree.lock);
2126 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
2129 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
2131 if (state && state->start <= failrec->start &&
2132 state->end >= failrec->start + failrec->len - 1) {
2133 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2135 if (num_copies > 1) {
2136 repair_io_failure(inode, start, failrec->len,
2137 failrec->logical, page,
2138 pg_offset, failrec->failed_mirror);
2143 free_io_failure(inode, failrec);
2149 * Can be called when
2150 * - hold extent lock
2151 * - under ordered extent
2152 * - the inode is freeing
2154 void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end)
2156 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2157 struct io_failure_record *failrec;
2158 struct extent_state *state, *next;
2160 if (RB_EMPTY_ROOT(&failure_tree->state))
2163 spin_lock(&failure_tree->lock);
2164 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2166 if (state->start > end)
2169 ASSERT(state->end <= end);
2171 next = next_state(state);
2173 failrec = state->failrec;
2174 free_extent_state(state);
2179 spin_unlock(&failure_tree->lock);
2182 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2183 struct io_failure_record **failrec_ret)
2185 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2186 struct io_failure_record *failrec;
2187 struct extent_map *em;
2188 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2189 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2190 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2194 ret = get_state_failrec(failure_tree, start, &failrec);
2196 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2200 failrec->start = start;
2201 failrec->len = end - start + 1;
2202 failrec->this_mirror = 0;
2203 failrec->bio_flags = 0;
2204 failrec->in_validation = 0;
2206 read_lock(&em_tree->lock);
2207 em = lookup_extent_mapping(em_tree, start, failrec->len);
2209 read_unlock(&em_tree->lock);
2214 if (em->start > start || em->start + em->len <= start) {
2215 free_extent_map(em);
2218 read_unlock(&em_tree->lock);
2224 logical = start - em->start;
2225 logical = em->block_start + logical;
2226 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2227 logical = em->block_start;
2228 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2229 extent_set_compress_type(&failrec->bio_flags,
2233 btrfs_debug(fs_info,
2234 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2235 logical, start, failrec->len);
2237 failrec->logical = logical;
2238 free_extent_map(em);
2240 /* set the bits in the private failure tree */
2241 ret = set_extent_bits(failure_tree, start, end,
2242 EXTENT_LOCKED | EXTENT_DIRTY);
2244 ret = set_state_failrec(failure_tree, start, failrec);
2245 /* set the bits in the inode's tree */
2247 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2253 btrfs_debug(fs_info,
2254 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2255 failrec->logical, failrec->start, failrec->len,
2256 failrec->in_validation);
2258 * when data can be on disk more than twice, add to failrec here
2259 * (e.g. with a list for failed_mirror) to make
2260 * clean_io_failure() clean all those errors at once.
2264 *failrec_ret = failrec;
2269 int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
2270 struct io_failure_record *failrec, int failed_mirror)
2272 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2275 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
2276 if (num_copies == 1) {
2278 * we only have a single copy of the data, so don't bother with
2279 * all the retry and error correction code that follows. no
2280 * matter what the error is, it is very likely to persist.
2282 btrfs_debug(fs_info,
2283 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2284 num_copies, failrec->this_mirror, failed_mirror);
2289 * there are two premises:
2290 * a) deliver good data to the caller
2291 * b) correct the bad sectors on disk
2293 if (failed_bio->bi_vcnt > 1) {
2295 * to fulfill b), we need to know the exact failing sectors, as
2296 * we don't want to rewrite any more than the failed ones. thus,
2297 * we need separate read requests for the failed bio
2299 * if the following BUG_ON triggers, our validation request got
2300 * merged. we need separate requests for our algorithm to work.
2302 BUG_ON(failrec->in_validation);
2303 failrec->in_validation = 1;
2304 failrec->this_mirror = failed_mirror;
2307 * we're ready to fulfill a) and b) alongside. get a good copy
2308 * of the failed sector and if we succeed, we have setup
2309 * everything for repair_io_failure to do the rest for us.
2311 if (failrec->in_validation) {
2312 BUG_ON(failrec->this_mirror != failed_mirror);
2313 failrec->in_validation = 0;
2314 failrec->this_mirror = 0;
2316 failrec->failed_mirror = failed_mirror;
2317 failrec->this_mirror++;
2318 if (failrec->this_mirror == failed_mirror)
2319 failrec->this_mirror++;
2322 if (failrec->this_mirror > num_copies) {
2323 btrfs_debug(fs_info,
2324 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2325 num_copies, failrec->this_mirror, failed_mirror);
2333 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
2334 struct io_failure_record *failrec,
2335 struct page *page, int pg_offset, int icsum,
2336 bio_end_io_t *endio_func, void *data)
2338 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2340 struct btrfs_io_bio *btrfs_failed_bio;
2341 struct btrfs_io_bio *btrfs_bio;
2343 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2347 bio->bi_end_io = endio_func;
2348 bio->bi_iter.bi_sector = failrec->logical >> 9;
2349 bio->bi_bdev = fs_info->fs_devices->latest_bdev;
2350 bio->bi_iter.bi_size = 0;
2351 bio->bi_private = data;
2353 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2354 if (btrfs_failed_bio->csum) {
2355 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2357 btrfs_bio = btrfs_io_bio(bio);
2358 btrfs_bio->csum = btrfs_bio->csum_inline;
2360 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
2364 bio_add_page(bio, page, failrec->len, pg_offset);
2370 * this is a generic handler for readpage errors (default
2371 * readpage_io_failed_hook). if other copies exist, read those and write back
2372 * good data to the failed position. does not investigate in remapping the
2373 * failed extent elsewhere, hoping the device will be smart enough to do this as
2377 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2378 struct page *page, u64 start, u64 end,
2381 struct io_failure_record *failrec;
2382 struct inode *inode = page->mapping->host;
2383 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2388 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2390 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2394 ret = btrfs_check_repairable(inode, failed_bio, failrec, failed_mirror);
2396 free_io_failure(inode, failrec);
2400 if (failed_bio->bi_vcnt > 1)
2401 read_mode |= REQ_FAILFAST_DEV;
2403 phy_offset >>= inode->i_sb->s_blocksize_bits;
2404 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
2405 start - page_offset(page),
2406 (int)phy_offset, failed_bio->bi_end_io,
2409 free_io_failure(inode, failrec);
2412 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
2414 btrfs_debug(btrfs_sb(inode->i_sb),
2415 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2416 read_mode, failrec->this_mirror, failrec->in_validation);
2418 ret = tree->ops->submit_bio_hook(inode, bio, failrec->this_mirror,
2419 failrec->bio_flags, 0);
2421 free_io_failure(inode, failrec);
2428 /* lots and lots of room for performance fixes in the end_bio funcs */
2430 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2432 int uptodate = (err == 0);
2433 struct extent_io_tree *tree;
2436 tree = &BTRFS_I(page->mapping->host)->io_tree;
2438 if (tree->ops && tree->ops->writepage_end_io_hook) {
2439 ret = tree->ops->writepage_end_io_hook(page, start,
2440 end, NULL, uptodate);
2446 ClearPageUptodate(page);
2448 ret = ret < 0 ? ret : -EIO;
2449 mapping_set_error(page->mapping, ret);
2454 * after a writepage IO is done, we need to:
2455 * clear the uptodate bits on error
2456 * clear the writeback bits in the extent tree for this IO
2457 * end_page_writeback if the page has no more pending IO
2459 * Scheduling is not allowed, so the extent state tree is expected
2460 * to have one and only one object corresponding to this IO.
2462 static void end_bio_extent_writepage(struct bio *bio)
2464 struct bio_vec *bvec;
2469 bio_for_each_segment_all(bvec, bio, i) {
2470 struct page *page = bvec->bv_page;
2471 struct inode *inode = page->mapping->host;
2472 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2474 /* We always issue full-page reads, but if some block
2475 * in a page fails to read, blk_update_request() will
2476 * advance bv_offset and adjust bv_len to compensate.
2477 * Print a warning for nonzero offsets, and an error
2478 * if they don't add up to a full page. */
2479 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2480 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2482 "partial page write in btrfs with offset %u and length %u",
2483 bvec->bv_offset, bvec->bv_len);
2486 "incomplete page write in btrfs with offset %u and length %u",
2487 bvec->bv_offset, bvec->bv_len);
2490 start = page_offset(page);
2491 end = start + bvec->bv_offset + bvec->bv_len - 1;
2493 end_extent_writepage(page, bio->bi_error, start, end);
2494 end_page_writeback(page);
2501 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2504 struct extent_state *cached = NULL;
2505 u64 end = start + len - 1;
2507 if (uptodate && tree->track_uptodate)
2508 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2509 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2513 * after a readpage IO is done, we need to:
2514 * clear the uptodate bits on error
2515 * set the uptodate bits if things worked
2516 * set the page up to date if all extents in the tree are uptodate
2517 * clear the lock bit in the extent tree
2518 * unlock the page if there are no other extents locked for it
2520 * Scheduling is not allowed, so the extent state tree is expected
2521 * to have one and only one object corresponding to this IO.
2523 static void end_bio_extent_readpage(struct bio *bio)
2525 struct bio_vec *bvec;
2526 int uptodate = !bio->bi_error;
2527 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2528 struct extent_io_tree *tree;
2533 u64 extent_start = 0;
2539 bio_for_each_segment_all(bvec, bio, i) {
2540 struct page *page = bvec->bv_page;
2541 struct inode *inode = page->mapping->host;
2542 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2544 btrfs_debug(fs_info,
2545 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2546 (u64)bio->bi_iter.bi_sector, bio->bi_error,
2547 io_bio->mirror_num);
2548 tree = &BTRFS_I(inode)->io_tree;
2550 /* We always issue full-page reads, but if some block
2551 * in a page fails to read, blk_update_request() will
2552 * advance bv_offset and adjust bv_len to compensate.
2553 * Print a warning for nonzero offsets, and an error
2554 * if they don't add up to a full page. */
2555 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2556 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2558 "partial page read in btrfs with offset %u and length %u",
2559 bvec->bv_offset, bvec->bv_len);
2562 "incomplete page read in btrfs with offset %u and length %u",
2563 bvec->bv_offset, bvec->bv_len);
2566 start = page_offset(page);
2567 end = start + bvec->bv_offset + bvec->bv_len - 1;
2570 mirror = io_bio->mirror_num;
2571 if (likely(uptodate && tree->ops &&
2572 tree->ops->readpage_end_io_hook)) {
2573 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2579 clean_io_failure(inode, start, page, 0);
2582 if (likely(uptodate))
2585 if (tree->ops && tree->ops->readpage_io_failed_hook) {
2586 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2587 if (!ret && !bio->bi_error)
2591 * The generic bio_readpage_error handles errors the
2592 * following way: If possible, new read requests are
2593 * created and submitted and will end up in
2594 * end_bio_extent_readpage as well (if we're lucky, not
2595 * in the !uptodate case). In that case it returns 0 and
2596 * we just go on with the next page in our bio. If it
2597 * can't handle the error it will return -EIO and we
2598 * remain responsible for that page.
2600 ret = bio_readpage_error(bio, offset, page, start, end,
2603 uptodate = !bio->bi_error;
2609 if (likely(uptodate)) {
2610 loff_t i_size = i_size_read(inode);
2611 pgoff_t end_index = i_size >> PAGE_SHIFT;
2614 /* Zero out the end if this page straddles i_size */
2615 off = i_size & (PAGE_SIZE-1);
2616 if (page->index == end_index && off)
2617 zero_user_segment(page, off, PAGE_SIZE);
2618 SetPageUptodate(page);
2620 ClearPageUptodate(page);
2626 if (unlikely(!uptodate)) {
2628 endio_readpage_release_extent(tree,
2634 endio_readpage_release_extent(tree, start,
2635 end - start + 1, 0);
2636 } else if (!extent_len) {
2637 extent_start = start;
2638 extent_len = end + 1 - start;
2639 } else if (extent_start + extent_len == start) {
2640 extent_len += end + 1 - start;
2642 endio_readpage_release_extent(tree, extent_start,
2643 extent_len, uptodate);
2644 extent_start = start;
2645 extent_len = end + 1 - start;
2650 endio_readpage_release_extent(tree, extent_start, extent_len,
2653 io_bio->end_io(io_bio, bio->bi_error);
2658 * this allocates from the btrfs_bioset. We're returning a bio right now
2659 * but you can call btrfs_io_bio for the appropriate container_of magic
2662 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2665 struct btrfs_io_bio *btrfs_bio;
2668 bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset);
2670 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2671 while (!bio && (nr_vecs /= 2)) {
2672 bio = bio_alloc_bioset(gfp_flags,
2673 nr_vecs, btrfs_bioset);
2678 bio->bi_bdev = bdev;
2679 bio->bi_iter.bi_sector = first_sector;
2680 btrfs_bio = btrfs_io_bio(bio);
2681 btrfs_bio->csum = NULL;
2682 btrfs_bio->csum_allocated = NULL;
2683 btrfs_bio->end_io = NULL;
2688 struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
2690 struct btrfs_io_bio *btrfs_bio;
2693 new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset);
2695 btrfs_bio = btrfs_io_bio(new);
2696 btrfs_bio->csum = NULL;
2697 btrfs_bio->csum_allocated = NULL;
2698 btrfs_bio->end_io = NULL;
2703 /* this also allocates from the btrfs_bioset */
2704 struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
2706 struct btrfs_io_bio *btrfs_bio;
2709 bio = bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
2711 btrfs_bio = btrfs_io_bio(bio);
2712 btrfs_bio->csum = NULL;
2713 btrfs_bio->csum_allocated = NULL;
2714 btrfs_bio->end_io = NULL;
2720 static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
2721 unsigned long bio_flags)
2724 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2725 struct page *page = bvec->bv_page;
2726 struct extent_io_tree *tree = bio->bi_private;
2729 start = page_offset(page) + bvec->bv_offset;
2731 bio->bi_private = NULL;
2734 if (tree->ops && tree->ops->submit_bio_hook)
2735 ret = tree->ops->submit_bio_hook(page->mapping->host, bio,
2736 mirror_num, bio_flags, start);
2738 btrfsic_submit_bio(bio);
2744 static int merge_bio(struct extent_io_tree *tree, struct page *page,
2745 unsigned long offset, size_t size, struct bio *bio,
2746 unsigned long bio_flags)
2749 if (tree->ops && tree->ops->merge_bio_hook)
2750 ret = tree->ops->merge_bio_hook(page, offset, size, bio,
2756 static int submit_extent_page(int op, int op_flags, struct extent_io_tree *tree,
2757 struct writeback_control *wbc,
2758 struct page *page, sector_t sector,
2759 size_t size, unsigned long offset,
2760 struct block_device *bdev,
2761 struct bio **bio_ret,
2762 bio_end_io_t end_io_func,
2764 unsigned long prev_bio_flags,
2765 unsigned long bio_flags,
2766 bool force_bio_submit)
2771 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2772 size_t page_size = min_t(size_t, size, PAGE_SIZE);
2774 if (bio_ret && *bio_ret) {
2777 contig = bio->bi_iter.bi_sector == sector;
2779 contig = bio_end_sector(bio) == sector;
2781 if (prev_bio_flags != bio_flags || !contig ||
2783 merge_bio(tree, page, offset, page_size, bio, bio_flags) ||
2784 bio_add_page(bio, page, page_size, offset) < page_size) {
2785 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
2793 wbc_account_io(wbc, page, page_size);
2798 bio = btrfs_bio_alloc(bdev, sector, BIO_MAX_PAGES,
2799 GFP_NOFS | __GFP_HIGH);
2803 bio_add_page(bio, page, page_size, offset);
2804 bio->bi_end_io = end_io_func;
2805 bio->bi_private = tree;
2806 bio_set_op_attrs(bio, op, op_flags);
2808 wbc_init_bio(wbc, bio);
2809 wbc_account_io(wbc, page, page_size);
2815 ret = submit_one_bio(bio, mirror_num, bio_flags);
2820 static void attach_extent_buffer_page(struct extent_buffer *eb,
2823 if (!PagePrivate(page)) {
2824 SetPagePrivate(page);
2826 set_page_private(page, (unsigned long)eb);
2828 WARN_ON(page->private != (unsigned long)eb);
2832 void set_page_extent_mapped(struct page *page)
2834 if (!PagePrivate(page)) {
2835 SetPagePrivate(page);
2837 set_page_private(page, EXTENT_PAGE_PRIVATE);
2841 static struct extent_map *
2842 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
2843 u64 start, u64 len, get_extent_t *get_extent,
2844 struct extent_map **em_cached)
2846 struct extent_map *em;
2848 if (em_cached && *em_cached) {
2850 if (extent_map_in_tree(em) && start >= em->start &&
2851 start < extent_map_end(em)) {
2852 atomic_inc(&em->refs);
2856 free_extent_map(em);
2860 em = get_extent(inode, page, pg_offset, start, len, 0);
2861 if (em_cached && !IS_ERR_OR_NULL(em)) {
2863 atomic_inc(&em->refs);
2869 * basic readpage implementation. Locked extent state structs are inserted
2870 * into the tree that are removed when the IO is done (by the end_io
2872 * XXX JDM: This needs looking at to ensure proper page locking
2873 * return 0 on success, otherwise return error
2875 static int __do_readpage(struct extent_io_tree *tree,
2877 get_extent_t *get_extent,
2878 struct extent_map **em_cached,
2879 struct bio **bio, int mirror_num,
2880 unsigned long *bio_flags, int read_flags,
2883 struct inode *inode = page->mapping->host;
2884 u64 start = page_offset(page);
2885 u64 page_end = start + PAGE_SIZE - 1;
2889 u64 last_byte = i_size_read(inode);
2893 struct extent_map *em;
2894 struct block_device *bdev;
2897 size_t pg_offset = 0;
2899 size_t disk_io_size;
2900 size_t blocksize = inode->i_sb->s_blocksize;
2901 unsigned long this_bio_flag = 0;
2903 set_page_extent_mapped(page);
2906 if (!PageUptodate(page)) {
2907 if (cleancache_get_page(page) == 0) {
2908 BUG_ON(blocksize != PAGE_SIZE);
2909 unlock_extent(tree, start, end);
2914 if (page->index == last_byte >> PAGE_SHIFT) {
2916 size_t zero_offset = last_byte & (PAGE_SIZE - 1);
2919 iosize = PAGE_SIZE - zero_offset;
2920 userpage = kmap_atomic(page);
2921 memset(userpage + zero_offset, 0, iosize);
2922 flush_dcache_page(page);
2923 kunmap_atomic(userpage);
2926 while (cur <= end) {
2927 bool force_bio_submit = false;
2929 if (cur >= last_byte) {
2931 struct extent_state *cached = NULL;
2933 iosize = PAGE_SIZE - pg_offset;
2934 userpage = kmap_atomic(page);
2935 memset(userpage + pg_offset, 0, iosize);
2936 flush_dcache_page(page);
2937 kunmap_atomic(userpage);
2938 set_extent_uptodate(tree, cur, cur + iosize - 1,
2940 unlock_extent_cached(tree, cur,
2945 em = __get_extent_map(inode, page, pg_offset, cur,
2946 end - cur + 1, get_extent, em_cached);
2947 if (IS_ERR_OR_NULL(em)) {
2949 unlock_extent(tree, cur, end);
2952 extent_offset = cur - em->start;
2953 BUG_ON(extent_map_end(em) <= cur);
2956 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2957 this_bio_flag |= EXTENT_BIO_COMPRESSED;
2958 extent_set_compress_type(&this_bio_flag,
2962 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2963 cur_end = min(extent_map_end(em) - 1, end);
2964 iosize = ALIGN(iosize, blocksize);
2965 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2966 disk_io_size = em->block_len;
2967 sector = em->block_start >> 9;
2969 sector = (em->block_start + extent_offset) >> 9;
2970 disk_io_size = iosize;
2973 block_start = em->block_start;
2974 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2975 block_start = EXTENT_MAP_HOLE;
2978 * If we have a file range that points to a compressed extent
2979 * and it's followed by a consecutive file range that points to
2980 * to the same compressed extent (possibly with a different
2981 * offset and/or length, so it either points to the whole extent
2982 * or only part of it), we must make sure we do not submit a
2983 * single bio to populate the pages for the 2 ranges because
2984 * this makes the compressed extent read zero out the pages
2985 * belonging to the 2nd range. Imagine the following scenario:
2988 * [0 - 8K] [8K - 24K]
2991 * points to extent X, points to extent X,
2992 * offset 4K, length of 8K offset 0, length 16K
2994 * [extent X, compressed length = 4K uncompressed length = 16K]
2996 * If the bio to read the compressed extent covers both ranges,
2997 * it will decompress extent X into the pages belonging to the
2998 * first range and then it will stop, zeroing out the remaining
2999 * pages that belong to the other range that points to extent X.
3000 * So here we make sure we submit 2 bios, one for the first
3001 * range and another one for the third range. Both will target
3002 * the same physical extent from disk, but we can't currently
3003 * make the compressed bio endio callback populate the pages
3004 * for both ranges because each compressed bio is tightly
3005 * coupled with a single extent map, and each range can have
3006 * an extent map with a different offset value relative to the
3007 * uncompressed data of our extent and different lengths. This
3008 * is a corner case so we prioritize correctness over
3009 * non-optimal behavior (submitting 2 bios for the same extent).
3011 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3012 prev_em_start && *prev_em_start != (u64)-1 &&
3013 *prev_em_start != em->orig_start)
3014 force_bio_submit = true;
3017 *prev_em_start = em->orig_start;
3019 free_extent_map(em);
3022 /* we've found a hole, just zero and go on */
3023 if (block_start == EXTENT_MAP_HOLE) {
3025 struct extent_state *cached = NULL;
3027 userpage = kmap_atomic(page);
3028 memset(userpage + pg_offset, 0, iosize);
3029 flush_dcache_page(page);
3030 kunmap_atomic(userpage);
3032 set_extent_uptodate(tree, cur, cur + iosize - 1,
3034 unlock_extent_cached(tree, cur,
3038 pg_offset += iosize;
3041 /* the get_extent function already copied into the page */
3042 if (test_range_bit(tree, cur, cur_end,
3043 EXTENT_UPTODATE, 1, NULL)) {
3044 check_page_uptodate(tree, page);
3045 unlock_extent(tree, cur, cur + iosize - 1);
3047 pg_offset += iosize;
3050 /* we have an inline extent but it didn't get marked up
3051 * to date. Error out
3053 if (block_start == EXTENT_MAP_INLINE) {
3055 unlock_extent(tree, cur, cur + iosize - 1);
3057 pg_offset += iosize;
3061 ret = submit_extent_page(REQ_OP_READ, read_flags, tree, NULL,
3062 page, sector, disk_io_size, pg_offset,
3064 end_bio_extent_readpage, mirror_num,
3070 *bio_flags = this_bio_flag;
3073 unlock_extent(tree, cur, cur + iosize - 1);
3077 pg_offset += iosize;
3081 if (!PageError(page))
3082 SetPageUptodate(page);
3088 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
3089 struct page *pages[], int nr_pages,
3091 get_extent_t *get_extent,
3092 struct extent_map **em_cached,
3093 struct bio **bio, int mirror_num,
3094 unsigned long *bio_flags,
3097 struct inode *inode;
3098 struct btrfs_ordered_extent *ordered;
3101 inode = pages[0]->mapping->host;
3103 lock_extent(tree, start, end);
3104 ordered = btrfs_lookup_ordered_range(inode, start,
3108 unlock_extent(tree, start, end);
3109 btrfs_start_ordered_extent(inode, ordered, 1);
3110 btrfs_put_ordered_extent(ordered);
3113 for (index = 0; index < nr_pages; index++) {
3114 __do_readpage(tree, pages[index], get_extent, em_cached, bio,
3115 mirror_num, bio_flags, 0, prev_em_start);
3116 put_page(pages[index]);
3120 static void __extent_readpages(struct extent_io_tree *tree,
3121 struct page *pages[],
3122 int nr_pages, get_extent_t *get_extent,
3123 struct extent_map **em_cached,
3124 struct bio **bio, int mirror_num,
3125 unsigned long *bio_flags,
3132 int first_index = 0;
3134 for (index = 0; index < nr_pages; index++) {
3135 page_start = page_offset(pages[index]);
3138 end = start + PAGE_SIZE - 1;
3139 first_index = index;
3140 } else if (end + 1 == page_start) {
3143 __do_contiguous_readpages(tree, &pages[first_index],
3144 index - first_index, start,
3145 end, get_extent, em_cached,
3146 bio, mirror_num, bio_flags,
3149 end = start + PAGE_SIZE - 1;
3150 first_index = index;
3155 __do_contiguous_readpages(tree, &pages[first_index],
3156 index - first_index, start,
3157 end, get_extent, em_cached, bio,
3158 mirror_num, bio_flags,
3162 static int __extent_read_full_page(struct extent_io_tree *tree,
3164 get_extent_t *get_extent,
3165 struct bio **bio, int mirror_num,
3166 unsigned long *bio_flags, int read_flags)
3168 struct inode *inode = page->mapping->host;
3169 struct btrfs_ordered_extent *ordered;
3170 u64 start = page_offset(page);
3171 u64 end = start + PAGE_SIZE - 1;
3175 lock_extent(tree, start, end);
3176 ordered = btrfs_lookup_ordered_range(inode, start,
3180 unlock_extent(tree, start, end);
3181 btrfs_start_ordered_extent(inode, ordered, 1);
3182 btrfs_put_ordered_extent(ordered);
3185 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3186 bio_flags, read_flags, NULL);
3190 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3191 get_extent_t *get_extent, int mirror_num)
3193 struct bio *bio = NULL;
3194 unsigned long bio_flags = 0;
3197 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3200 ret = submit_one_bio(bio, mirror_num, bio_flags);
3204 static void update_nr_written(struct writeback_control *wbc,
3205 unsigned long nr_written)
3207 wbc->nr_to_write -= nr_written;
3211 * helper for __extent_writepage, doing all of the delayed allocation setup.
3213 * This returns 1 if our fill_delalloc function did all the work required
3214 * to write the page (copy into inline extent). In this case the IO has
3215 * been started and the page is already unlocked.
3217 * This returns 0 if all went well (page still locked)
3218 * This returns < 0 if there were errors (page still locked)
3220 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3221 struct page *page, struct writeback_control *wbc,
3222 struct extent_page_data *epd,
3224 unsigned long *nr_written)
3226 struct extent_io_tree *tree = epd->tree;
3227 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3229 u64 delalloc_to_write = 0;
3230 u64 delalloc_end = 0;
3232 int page_started = 0;
3234 if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
3237 while (delalloc_end < page_end) {
3238 nr_delalloc = find_lock_delalloc_range(inode, tree,
3242 BTRFS_MAX_EXTENT_SIZE);
3243 if (nr_delalloc == 0) {
3244 delalloc_start = delalloc_end + 1;
3247 ret = tree->ops->fill_delalloc(inode, page,
3252 /* File system has been set read-only */
3255 /* fill_delalloc should be return < 0 for error
3256 * but just in case, we use > 0 here meaning the
3257 * IO is started, so we don't want to return > 0
3258 * unless things are going well.
3260 ret = ret < 0 ? ret : -EIO;
3264 * delalloc_end is already one less than the total length, so
3265 * we don't subtract one from PAGE_SIZE
3267 delalloc_to_write += (delalloc_end - delalloc_start +
3268 PAGE_SIZE) >> PAGE_SHIFT;
3269 delalloc_start = delalloc_end + 1;
3271 if (wbc->nr_to_write < delalloc_to_write) {
3274 if (delalloc_to_write < thresh * 2)
3275 thresh = delalloc_to_write;
3276 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3280 /* did the fill delalloc function already unlock and start
3285 * we've unlocked the page, so we can't update
3286 * the mapping's writeback index, just update
3289 wbc->nr_to_write -= *nr_written;
3300 * helper for __extent_writepage. This calls the writepage start hooks,
3301 * and does the loop to map the page into extents and bios.
3303 * We return 1 if the IO is started and the page is unlocked,
3304 * 0 if all went well (page still locked)
3305 * < 0 if there were errors (page still locked)
3307 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3309 struct writeback_control *wbc,
3310 struct extent_page_data *epd,
3312 unsigned long nr_written,
3313 int write_flags, int *nr_ret)
3315 struct extent_io_tree *tree = epd->tree;
3316 u64 start = page_offset(page);
3317 u64 page_end = start + PAGE_SIZE - 1;
3324 struct extent_map *em;
3325 struct block_device *bdev;
3326 size_t pg_offset = 0;
3332 if (tree->ops && tree->ops->writepage_start_hook) {
3333 ret = tree->ops->writepage_start_hook(page, start,
3336 /* Fixup worker will requeue */
3338 wbc->pages_skipped++;
3340 redirty_page_for_writepage(wbc, page);
3342 update_nr_written(wbc, nr_written);
3349 * we don't want to touch the inode after unlocking the page,
3350 * so we update the mapping writeback index now
3352 update_nr_written(wbc, nr_written + 1);
3355 if (i_size <= start) {
3356 if (tree->ops && tree->ops->writepage_end_io_hook)
3357 tree->ops->writepage_end_io_hook(page, start,
3362 blocksize = inode->i_sb->s_blocksize;
3364 while (cur <= end) {
3367 if (cur >= i_size) {
3368 if (tree->ops && tree->ops->writepage_end_io_hook)
3369 tree->ops->writepage_end_io_hook(page, cur,
3373 em = epd->get_extent(inode, page, pg_offset, cur,
3375 if (IS_ERR_OR_NULL(em)) {
3377 ret = PTR_ERR_OR_ZERO(em);
3381 extent_offset = cur - em->start;
3382 em_end = extent_map_end(em);
3383 BUG_ON(em_end <= cur);
3385 iosize = min(em_end - cur, end - cur + 1);
3386 iosize = ALIGN(iosize, blocksize);
3387 sector = (em->block_start + extent_offset) >> 9;
3389 block_start = em->block_start;
3390 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3391 free_extent_map(em);
3395 * compressed and inline extents are written through other
3398 if (compressed || block_start == EXTENT_MAP_HOLE ||
3399 block_start == EXTENT_MAP_INLINE) {
3401 * end_io notification does not happen here for
3402 * compressed extents
3404 if (!compressed && tree->ops &&
3405 tree->ops->writepage_end_io_hook)
3406 tree->ops->writepage_end_io_hook(page, cur,
3409 else if (compressed) {
3410 /* we don't want to end_page_writeback on
3411 * a compressed extent. this happens
3418 pg_offset += iosize;
3422 set_range_writeback(tree, cur, cur + iosize - 1);
3423 if (!PageWriteback(page)) {
3424 btrfs_err(BTRFS_I(inode)->root->fs_info,
3425 "page %lu not writeback, cur %llu end %llu",
3426 page->index, cur, end);
3429 ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
3430 page, sector, iosize, pg_offset,
3432 end_bio_extent_writepage,
3436 if (PageWriteback(page))
3437 end_page_writeback(page);
3441 pg_offset += iosize;
3450 * the writepage semantics are similar to regular writepage. extent
3451 * records are inserted to lock ranges in the tree, and as dirty areas
3452 * are found, they are marked writeback. Then the lock bits are removed
3453 * and the end_io handler clears the writeback ranges
3455 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3458 struct inode *inode = page->mapping->host;
3459 struct extent_page_data *epd = data;
3460 u64 start = page_offset(page);
3461 u64 page_end = start + PAGE_SIZE - 1;
3464 size_t pg_offset = 0;
3465 loff_t i_size = i_size_read(inode);
3466 unsigned long end_index = i_size >> PAGE_SHIFT;
3467 int write_flags = 0;
3468 unsigned long nr_written = 0;
3470 if (wbc->sync_mode == WB_SYNC_ALL)
3471 write_flags = REQ_SYNC;
3473 trace___extent_writepage(page, inode, wbc);
3475 WARN_ON(!PageLocked(page));
3477 ClearPageError(page);
3479 pg_offset = i_size & (PAGE_SIZE - 1);
3480 if (page->index > end_index ||
3481 (page->index == end_index && !pg_offset)) {
3482 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3487 if (page->index == end_index) {
3490 userpage = kmap_atomic(page);
3491 memset(userpage + pg_offset, 0,
3492 PAGE_SIZE - pg_offset);
3493 kunmap_atomic(userpage);
3494 flush_dcache_page(page);
3499 set_page_extent_mapped(page);
3501 ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
3507 ret = __extent_writepage_io(inode, page, wbc, epd,
3508 i_size, nr_written, write_flags, &nr);
3514 /* make sure the mapping tag for page dirty gets cleared */
3515 set_page_writeback(page);
3516 end_page_writeback(page);
3518 if (PageError(page)) {
3519 ret = ret < 0 ? ret : -EIO;
3520 end_extent_writepage(page, ret, start, page_end);
3529 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3531 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3532 TASK_UNINTERRUPTIBLE);
3535 static noinline_for_stack int
3536 lock_extent_buffer_for_io(struct extent_buffer *eb,
3537 struct btrfs_fs_info *fs_info,
3538 struct extent_page_data *epd)
3540 unsigned long i, num_pages;
3544 if (!btrfs_try_tree_write_lock(eb)) {
3546 flush_write_bio(epd);
3547 btrfs_tree_lock(eb);
3550 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3551 btrfs_tree_unlock(eb);
3555 flush_write_bio(epd);
3559 wait_on_extent_buffer_writeback(eb);
3560 btrfs_tree_lock(eb);
3561 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3563 btrfs_tree_unlock(eb);
3568 * We need to do this to prevent races in people who check if the eb is
3569 * under IO since we can end up having no IO bits set for a short period
3572 spin_lock(&eb->refs_lock);
3573 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3574 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3575 spin_unlock(&eb->refs_lock);
3576 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3577 __percpu_counter_add(&fs_info->dirty_metadata_bytes,
3579 fs_info->dirty_metadata_batch);
3582 spin_unlock(&eb->refs_lock);
3585 btrfs_tree_unlock(eb);
3590 num_pages = num_extent_pages(eb->start, eb->len);
3591 for (i = 0; i < num_pages; i++) {
3592 struct page *p = eb->pages[i];
3594 if (!trylock_page(p)) {
3596 flush_write_bio(epd);
3606 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3608 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3609 smp_mb__after_atomic();
3610 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3613 static void set_btree_ioerr(struct page *page)
3615 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3618 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3622 * If writeback for a btree extent that doesn't belong to a log tree
3623 * failed, increment the counter transaction->eb_write_errors.
3624 * We do this because while the transaction is running and before it's
3625 * committing (when we call filemap_fdata[write|wait]_range against
3626 * the btree inode), we might have
3627 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3628 * returns an error or an error happens during writeback, when we're
3629 * committing the transaction we wouldn't know about it, since the pages
3630 * can be no longer dirty nor marked anymore for writeback (if a
3631 * subsequent modification to the extent buffer didn't happen before the
3632 * transaction commit), which makes filemap_fdata[write|wait]_range not
3633 * able to find the pages tagged with SetPageError at transaction
3634 * commit time. So if this happens we must abort the transaction,
3635 * otherwise we commit a super block with btree roots that point to
3636 * btree nodes/leafs whose content on disk is invalid - either garbage
3637 * or the content of some node/leaf from a past generation that got
3638 * cowed or deleted and is no longer valid.
3640 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3641 * not be enough - we need to distinguish between log tree extents vs
3642 * non-log tree extents, and the next filemap_fdatawait_range() call
3643 * will catch and clear such errors in the mapping - and that call might
3644 * be from a log sync and not from a transaction commit. Also, checking
3645 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3646 * not done and would not be reliable - the eb might have been released
3647 * from memory and reading it back again means that flag would not be
3648 * set (since it's a runtime flag, not persisted on disk).
3650 * Using the flags below in the btree inode also makes us achieve the
3651 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3652 * writeback for all dirty pages and before filemap_fdatawait_range()
3653 * is called, the writeback for all dirty pages had already finished
3654 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3655 * filemap_fdatawait_range() would return success, as it could not know
3656 * that writeback errors happened (the pages were no longer tagged for
3659 switch (eb->log_index) {
3661 set_bit(BTRFS_FS_BTREE_ERR, &eb->fs_info->flags);
3664 set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags);
3667 set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags);
3670 BUG(); /* unexpected, logic error */
3674 static void end_bio_extent_buffer_writepage(struct bio *bio)
3676 struct bio_vec *bvec;
3677 struct extent_buffer *eb;
3680 bio_for_each_segment_all(bvec, bio, i) {
3681 struct page *page = bvec->bv_page;
3683 eb = (struct extent_buffer *)page->private;
3685 done = atomic_dec_and_test(&eb->io_pages);
3687 if (bio->bi_error ||
3688 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3689 ClearPageUptodate(page);
3690 set_btree_ioerr(page);
3693 end_page_writeback(page);
3698 end_extent_buffer_writeback(eb);
3704 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3705 struct btrfs_fs_info *fs_info,
3706 struct writeback_control *wbc,
3707 struct extent_page_data *epd)
3709 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3710 struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
3711 u64 offset = eb->start;
3713 unsigned long i, num_pages;
3714 unsigned long bio_flags = 0;
3715 unsigned long start, end;
3716 int write_flags = (epd->sync_io ? REQ_SYNC : 0) | REQ_META;
3719 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3720 num_pages = num_extent_pages(eb->start, eb->len);
3721 atomic_set(&eb->io_pages, num_pages);
3722 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3723 bio_flags = EXTENT_BIO_TREE_LOG;
3725 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3726 nritems = btrfs_header_nritems(eb);
3727 if (btrfs_header_level(eb) > 0) {
3728 end = btrfs_node_key_ptr_offset(nritems);
3730 memzero_extent_buffer(eb, end, eb->len - end);
3734 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3736 start = btrfs_item_nr_offset(nritems);
3737 end = btrfs_leaf_data(eb) + leaf_data_end(fs_info, eb);
3738 memzero_extent_buffer(eb, start, end - start);
3741 for (i = 0; i < num_pages; i++) {
3742 struct page *p = eb->pages[i];
3744 clear_page_dirty_for_io(p);
3745 set_page_writeback(p);
3746 ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
3747 p, offset >> 9, PAGE_SIZE, 0, bdev,
3749 end_bio_extent_buffer_writepage,
3750 0, epd->bio_flags, bio_flags, false);
3751 epd->bio_flags = bio_flags;
3754 if (PageWriteback(p))
3755 end_page_writeback(p);
3756 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3757 end_extent_buffer_writeback(eb);
3761 offset += PAGE_SIZE;
3762 update_nr_written(wbc, 1);
3766 if (unlikely(ret)) {
3767 for (; i < num_pages; i++) {
3768 struct page *p = eb->pages[i];
3769 clear_page_dirty_for_io(p);
3777 int btree_write_cache_pages(struct address_space *mapping,
3778 struct writeback_control *wbc)
3780 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3781 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3782 struct extent_buffer *eb, *prev_eb = NULL;
3783 struct extent_page_data epd = {
3787 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3792 int nr_to_write_done = 0;
3793 struct pagevec pvec;
3796 pgoff_t end; /* Inclusive */
3800 pagevec_init(&pvec, 0);
3801 if (wbc->range_cyclic) {
3802 index = mapping->writeback_index; /* Start from prev offset */
3805 index = wbc->range_start >> PAGE_SHIFT;
3806 end = wbc->range_end >> PAGE_SHIFT;
3809 if (wbc->sync_mode == WB_SYNC_ALL)
3810 tag = PAGECACHE_TAG_TOWRITE;
3812 tag = PAGECACHE_TAG_DIRTY;
3814 if (wbc->sync_mode == WB_SYNC_ALL)
3815 tag_pages_for_writeback(mapping, index, end);
3816 while (!done && !nr_to_write_done && (index <= end) &&
3817 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3818 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3822 for (i = 0; i < nr_pages; i++) {
3823 struct page *page = pvec.pages[i];
3825 if (!PagePrivate(page))
3828 if (!wbc->range_cyclic && page->index > end) {
3833 spin_lock(&mapping->private_lock);
3834 if (!PagePrivate(page)) {
3835 spin_unlock(&mapping->private_lock);
3839 eb = (struct extent_buffer *)page->private;
3842 * Shouldn't happen and normally this would be a BUG_ON
3843 * but no sense in crashing the users box for something
3844 * we can survive anyway.
3847 spin_unlock(&mapping->private_lock);
3851 if (eb == prev_eb) {
3852 spin_unlock(&mapping->private_lock);
3856 ret = atomic_inc_not_zero(&eb->refs);
3857 spin_unlock(&mapping->private_lock);
3862 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3864 free_extent_buffer(eb);
3868 ret = write_one_eb(eb, fs_info, wbc, &epd);
3871 free_extent_buffer(eb);
3874 free_extent_buffer(eb);
3877 * the filesystem may choose to bump up nr_to_write.
3878 * We have to make sure to honor the new nr_to_write
3881 nr_to_write_done = wbc->nr_to_write <= 0;
3883 pagevec_release(&pvec);
3886 if (!scanned && !done) {
3888 * We hit the last page and there is more work to be done: wrap
3889 * back to the start of the file
3895 flush_write_bio(&epd);
3900 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3901 * @mapping: address space structure to write
3902 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3903 * @writepage: function called for each page
3904 * @data: data passed to writepage function
3906 * If a page is already under I/O, write_cache_pages() skips it, even
3907 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3908 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3909 * and msync() need to guarantee that all the data which was dirty at the time
3910 * the call was made get new I/O started against them. If wbc->sync_mode is
3911 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3912 * existing IO to complete.
3914 static int extent_write_cache_pages(struct address_space *mapping,
3915 struct writeback_control *wbc,
3916 writepage_t writepage, void *data,
3917 void (*flush_fn)(void *))
3919 struct inode *inode = mapping->host;
3922 int nr_to_write_done = 0;
3923 struct pagevec pvec;
3926 pgoff_t end; /* Inclusive */
3928 int range_whole = 0;
3933 * We have to hold onto the inode so that ordered extents can do their
3934 * work when the IO finishes. The alternative to this is failing to add
3935 * an ordered extent if the igrab() fails there and that is a huge pain
3936 * to deal with, so instead just hold onto the inode throughout the
3937 * writepages operation. If it fails here we are freeing up the inode
3938 * anyway and we'd rather not waste our time writing out stuff that is
3939 * going to be truncated anyway.
3944 pagevec_init(&pvec, 0);
3945 if (wbc->range_cyclic) {
3946 index = mapping->writeback_index; /* Start from prev offset */
3949 index = wbc->range_start >> PAGE_SHIFT;
3950 end = wbc->range_end >> PAGE_SHIFT;
3951 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
3955 if (wbc->sync_mode == WB_SYNC_ALL)
3956 tag = PAGECACHE_TAG_TOWRITE;
3958 tag = PAGECACHE_TAG_DIRTY;
3960 if (wbc->sync_mode == WB_SYNC_ALL)
3961 tag_pages_for_writeback(mapping, index, end);
3963 while (!done && !nr_to_write_done && (index <= end) &&
3964 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3965 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3969 for (i = 0; i < nr_pages; i++) {
3970 struct page *page = pvec.pages[i];
3972 done_index = page->index;
3974 * At this point we hold neither mapping->tree_lock nor
3975 * lock on the page itself: the page may be truncated or
3976 * invalidated (changing page->mapping to NULL), or even
3977 * swizzled back from swapper_space to tmpfs file
3980 if (!trylock_page(page)) {
3985 if (unlikely(page->mapping != mapping)) {
3990 if (!wbc->range_cyclic && page->index > end) {
3996 if (wbc->sync_mode != WB_SYNC_NONE) {
3997 if (PageWriteback(page))
3999 wait_on_page_writeback(page);
4002 if (PageWriteback(page) ||
4003 !clear_page_dirty_for_io(page)) {
4008 ret = (*writepage)(page, wbc, data);
4010 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
4016 * done_index is set past this page,
4017 * so media errors will not choke
4018 * background writeout for the entire
4019 * file. This has consequences for
4020 * range_cyclic semantics (ie. it may
4021 * not be suitable for data integrity
4024 done_index = page->index + 1;
4030 * the filesystem may choose to bump up nr_to_write.
4031 * We have to make sure to honor the new nr_to_write
4034 nr_to_write_done = wbc->nr_to_write <= 0;
4036 pagevec_release(&pvec);
4039 if (!scanned && !done) {
4041 * We hit the last page and there is more work to be done: wrap
4042 * back to the start of the file
4049 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4050 mapping->writeback_index = done_index;
4052 btrfs_add_delayed_iput(inode);
4056 static void flush_epd_write_bio(struct extent_page_data *epd)
4061 bio_set_op_attrs(epd->bio, REQ_OP_WRITE,
4062 epd->sync_io ? REQ_SYNC : 0);
4064 ret = submit_one_bio(epd->bio, 0, epd->bio_flags);
4065 BUG_ON(ret < 0); /* -ENOMEM */
4070 static noinline void flush_write_bio(void *data)
4072 struct extent_page_data *epd = data;
4073 flush_epd_write_bio(epd);
4076 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
4077 get_extent_t *get_extent,
4078 struct writeback_control *wbc)
4081 struct extent_page_data epd = {
4084 .get_extent = get_extent,
4086 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4090 ret = __extent_writepage(page, wbc, &epd);
4092 flush_epd_write_bio(&epd);
4096 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
4097 u64 start, u64 end, get_extent_t *get_extent,
4101 struct address_space *mapping = inode->i_mapping;
4103 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4106 struct extent_page_data epd = {
4109 .get_extent = get_extent,
4111 .sync_io = mode == WB_SYNC_ALL,
4114 struct writeback_control wbc_writepages = {
4116 .nr_to_write = nr_pages * 2,
4117 .range_start = start,
4118 .range_end = end + 1,
4121 while (start <= end) {
4122 page = find_get_page(mapping, start >> PAGE_SHIFT);
4123 if (clear_page_dirty_for_io(page))
4124 ret = __extent_writepage(page, &wbc_writepages, &epd);
4126 if (tree->ops && tree->ops->writepage_end_io_hook)
4127 tree->ops->writepage_end_io_hook(page, start,
4128 start + PAGE_SIZE - 1,
4136 flush_epd_write_bio(&epd);
4140 int extent_writepages(struct extent_io_tree *tree,
4141 struct address_space *mapping,
4142 get_extent_t *get_extent,
4143 struct writeback_control *wbc)
4146 struct extent_page_data epd = {
4149 .get_extent = get_extent,
4151 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4155 ret = extent_write_cache_pages(mapping, wbc, __extent_writepage, &epd,
4157 flush_epd_write_bio(&epd);
4161 int extent_readpages(struct extent_io_tree *tree,
4162 struct address_space *mapping,
4163 struct list_head *pages, unsigned nr_pages,
4164 get_extent_t get_extent)
4166 struct bio *bio = NULL;
4168 unsigned long bio_flags = 0;
4169 struct page *pagepool[16];
4171 struct extent_map *em_cached = NULL;
4173 u64 prev_em_start = (u64)-1;
4175 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
4176 page = list_entry(pages->prev, struct page, lru);
4178 prefetchw(&page->flags);
4179 list_del(&page->lru);
4180 if (add_to_page_cache_lru(page, mapping,
4182 readahead_gfp_mask(mapping))) {
4187 pagepool[nr++] = page;
4188 if (nr < ARRAY_SIZE(pagepool))
4190 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4191 &bio, 0, &bio_flags, &prev_em_start);
4195 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4196 &bio, 0, &bio_flags, &prev_em_start);
4199 free_extent_map(em_cached);
4201 BUG_ON(!list_empty(pages));
4203 return submit_one_bio(bio, 0, bio_flags);
4208 * basic invalidatepage code, this waits on any locked or writeback
4209 * ranges corresponding to the page, and then deletes any extent state
4210 * records from the tree
4212 int extent_invalidatepage(struct extent_io_tree *tree,
4213 struct page *page, unsigned long offset)
4215 struct extent_state *cached_state = NULL;
4216 u64 start = page_offset(page);
4217 u64 end = start + PAGE_SIZE - 1;
4218 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4220 start += ALIGN(offset, blocksize);
4224 lock_extent_bits(tree, start, end, &cached_state);
4225 wait_on_page_writeback(page);
4226 clear_extent_bit(tree, start, end,
4227 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
4228 EXTENT_DO_ACCOUNTING,
4229 1, 1, &cached_state, GFP_NOFS);
4234 * a helper for releasepage, this tests for areas of the page that
4235 * are locked or under IO and drops the related state bits if it is safe
4238 static int try_release_extent_state(struct extent_map_tree *map,
4239 struct extent_io_tree *tree,
4240 struct page *page, gfp_t mask)
4242 u64 start = page_offset(page);
4243 u64 end = start + PAGE_SIZE - 1;
4246 if (test_range_bit(tree, start, end,
4247 EXTENT_IOBITS, 0, NULL))
4251 * at this point we can safely clear everything except the
4252 * locked bit and the nodatasum bit
4254 ret = clear_extent_bit(tree, start, end,
4255 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4258 /* if clear_extent_bit failed for enomem reasons,
4259 * we can't allow the release to continue.
4270 * a helper for releasepage. As long as there are no locked extents
4271 * in the range corresponding to the page, both state records and extent
4272 * map records are removed
4274 int try_release_extent_mapping(struct extent_map_tree *map,
4275 struct extent_io_tree *tree, struct page *page,
4278 struct extent_map *em;
4279 u64 start = page_offset(page);
4280 u64 end = start + PAGE_SIZE - 1;
4282 if (gfpflags_allow_blocking(mask) &&
4283 page->mapping->host->i_size > SZ_16M) {
4285 while (start <= end) {
4286 len = end - start + 1;
4287 write_lock(&map->lock);
4288 em = lookup_extent_mapping(map, start, len);
4290 write_unlock(&map->lock);
4293 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4294 em->start != start) {
4295 write_unlock(&map->lock);
4296 free_extent_map(em);
4299 if (!test_range_bit(tree, em->start,
4300 extent_map_end(em) - 1,
4301 EXTENT_LOCKED | EXTENT_WRITEBACK,
4303 remove_extent_mapping(map, em);
4304 /* once for the rb tree */
4305 free_extent_map(em);
4307 start = extent_map_end(em);
4308 write_unlock(&map->lock);
4311 free_extent_map(em);
4314 return try_release_extent_state(map, tree, page, mask);
4318 * helper function for fiemap, which doesn't want to see any holes.
4319 * This maps until we find something past 'last'
4321 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4324 get_extent_t *get_extent)
4326 u64 sectorsize = btrfs_inode_sectorsize(inode);
4327 struct extent_map *em;
4334 len = last - offset;
4337 len = ALIGN(len, sectorsize);
4338 em = get_extent(inode, NULL, 0, offset, len, 0);
4339 if (IS_ERR_OR_NULL(em))
4342 /* if this isn't a hole return it */
4343 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
4344 em->block_start != EXTENT_MAP_HOLE) {
4348 /* this is a hole, advance to the next extent */
4349 offset = extent_map_end(em);
4350 free_extent_map(em);
4357 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4358 __u64 start, __u64 len, get_extent_t *get_extent)
4362 u64 max = start + len;
4366 u64 last_for_get_extent = 0;
4368 u64 isize = i_size_read(inode);
4369 struct btrfs_key found_key;
4370 struct extent_map *em = NULL;
4371 struct extent_state *cached_state = NULL;
4372 struct btrfs_path *path;
4373 struct btrfs_root *root = BTRFS_I(inode)->root;
4382 path = btrfs_alloc_path();
4385 path->leave_spinning = 1;
4387 start = round_down(start, btrfs_inode_sectorsize(inode));
4388 len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
4391 * lookup the last file extent. We're not using i_size here
4392 * because there might be preallocation past i_size
4394 ret = btrfs_lookup_file_extent(NULL, root, path,
4395 btrfs_ino(BTRFS_I(inode)), -1, 0);
4397 btrfs_free_path(path);
4406 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4407 found_type = found_key.type;
4409 /* No extents, but there might be delalloc bits */
4410 if (found_key.objectid != btrfs_ino(BTRFS_I(inode)) ||
4411 found_type != BTRFS_EXTENT_DATA_KEY) {
4412 /* have to trust i_size as the end */
4414 last_for_get_extent = isize;
4417 * remember the start of the last extent. There are a
4418 * bunch of different factors that go into the length of the
4419 * extent, so its much less complex to remember where it started
4421 last = found_key.offset;
4422 last_for_get_extent = last + 1;
4424 btrfs_release_path(path);
4427 * we might have some extents allocated but more delalloc past those
4428 * extents. so, we trust isize unless the start of the last extent is
4433 last_for_get_extent = isize;
4436 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4439 em = get_extent_skip_holes(inode, start, last_for_get_extent,
4449 u64 offset_in_extent = 0;
4451 /* break if the extent we found is outside the range */
4452 if (em->start >= max || extent_map_end(em) < off)
4456 * get_extent may return an extent that starts before our
4457 * requested range. We have to make sure the ranges
4458 * we return to fiemap always move forward and don't
4459 * overlap, so adjust the offsets here
4461 em_start = max(em->start, off);
4464 * record the offset from the start of the extent
4465 * for adjusting the disk offset below. Only do this if the
4466 * extent isn't compressed since our in ram offset may be past
4467 * what we have actually allocated on disk.
4469 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4470 offset_in_extent = em_start - em->start;
4471 em_end = extent_map_end(em);
4472 em_len = em_end - em_start;
4477 * bump off for our next call to get_extent
4479 off = extent_map_end(em);
4483 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4485 flags |= FIEMAP_EXTENT_LAST;
4486 } else if (em->block_start == EXTENT_MAP_INLINE) {
4487 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4488 FIEMAP_EXTENT_NOT_ALIGNED);
4489 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4490 flags |= (FIEMAP_EXTENT_DELALLOC |
4491 FIEMAP_EXTENT_UNKNOWN);
4492 } else if (fieinfo->fi_extents_max) {
4493 struct btrfs_trans_handle *trans;
4495 u64 bytenr = em->block_start -
4496 (em->start - em->orig_start);
4498 disko = em->block_start + offset_in_extent;
4501 * We need a trans handle to get delayed refs
4503 trans = btrfs_join_transaction(root);
4505 * It's OK if we can't start a trans we can still check
4512 * As btrfs supports shared space, this information
4513 * can be exported to userspace tools via
4514 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4515 * then we're just getting a count and we can skip the
4518 ret = btrfs_check_shared(trans, root->fs_info,
4520 btrfs_ino(BTRFS_I(inode)), bytenr);
4522 btrfs_end_transaction(trans);
4526 flags |= FIEMAP_EXTENT_SHARED;
4529 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4530 flags |= FIEMAP_EXTENT_ENCODED;
4531 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4532 flags |= FIEMAP_EXTENT_UNWRITTEN;
4534 free_extent_map(em);
4536 if ((em_start >= last) || em_len == (u64)-1 ||
4537 (last == (u64)-1 && isize <= em_end)) {
4538 flags |= FIEMAP_EXTENT_LAST;
4542 /* now scan forward to see if this is really the last extent. */
4543 em = get_extent_skip_holes(inode, off, last_for_get_extent,
4550 flags |= FIEMAP_EXTENT_LAST;
4553 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
4562 free_extent_map(em);
4564 btrfs_free_path(path);
4565 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4566 &cached_state, GFP_NOFS);
4570 static void __free_extent_buffer(struct extent_buffer *eb)
4572 btrfs_leak_debug_del(&eb->leak_list);
4573 kmem_cache_free(extent_buffer_cache, eb);
4576 int extent_buffer_under_io(struct extent_buffer *eb)
4578 return (atomic_read(&eb->io_pages) ||
4579 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4580 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4584 * Helper for releasing extent buffer page.
4586 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb)
4588 unsigned long index;
4590 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4592 BUG_ON(extent_buffer_under_io(eb));
4594 index = num_extent_pages(eb->start, eb->len);
4600 page = eb->pages[index];
4604 spin_lock(&page->mapping->private_lock);
4606 * We do this since we'll remove the pages after we've
4607 * removed the eb from the radix tree, so we could race
4608 * and have this page now attached to the new eb. So
4609 * only clear page_private if it's still connected to
4612 if (PagePrivate(page) &&
4613 page->private == (unsigned long)eb) {
4614 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4615 BUG_ON(PageDirty(page));
4616 BUG_ON(PageWriteback(page));
4618 * We need to make sure we haven't be attached
4621 ClearPagePrivate(page);
4622 set_page_private(page, 0);
4623 /* One for the page private */
4628 spin_unlock(&page->mapping->private_lock);
4630 /* One for when we allocated the page */
4632 } while (index != 0);
4636 * Helper for releasing the extent buffer.
4638 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4640 btrfs_release_extent_buffer_page(eb);
4641 __free_extent_buffer(eb);
4644 static struct extent_buffer *
4645 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4648 struct extent_buffer *eb = NULL;
4650 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4653 eb->fs_info = fs_info;
4655 rwlock_init(&eb->lock);
4656 atomic_set(&eb->write_locks, 0);
4657 atomic_set(&eb->read_locks, 0);
4658 atomic_set(&eb->blocking_readers, 0);
4659 atomic_set(&eb->blocking_writers, 0);
4660 atomic_set(&eb->spinning_readers, 0);
4661 atomic_set(&eb->spinning_writers, 0);
4662 eb->lock_nested = 0;
4663 init_waitqueue_head(&eb->write_lock_wq);
4664 init_waitqueue_head(&eb->read_lock_wq);
4666 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4668 spin_lock_init(&eb->refs_lock);
4669 atomic_set(&eb->refs, 1);
4670 atomic_set(&eb->io_pages, 0);
4673 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4675 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4676 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4677 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4682 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4686 struct extent_buffer *new;
4687 unsigned long num_pages = num_extent_pages(src->start, src->len);
4689 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
4693 for (i = 0; i < num_pages; i++) {
4694 p = alloc_page(GFP_NOFS);
4696 btrfs_release_extent_buffer(new);
4699 attach_extent_buffer_page(new, p);
4700 WARN_ON(PageDirty(p));
4703 copy_page(page_address(p), page_address(src->pages[i]));
4706 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4707 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4712 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4713 u64 start, unsigned long len)
4715 struct extent_buffer *eb;
4716 unsigned long num_pages;
4719 num_pages = num_extent_pages(start, len);
4721 eb = __alloc_extent_buffer(fs_info, start, len);
4725 for (i = 0; i < num_pages; i++) {
4726 eb->pages[i] = alloc_page(GFP_NOFS);
4730 set_extent_buffer_uptodate(eb);
4731 btrfs_set_header_nritems(eb, 0);
4732 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4737 __free_page(eb->pages[i - 1]);
4738 __free_extent_buffer(eb);
4742 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4745 return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
4748 static void check_buffer_tree_ref(struct extent_buffer *eb)
4751 /* the ref bit is tricky. We have to make sure it is set
4752 * if we have the buffer dirty. Otherwise the
4753 * code to free a buffer can end up dropping a dirty
4756 * Once the ref bit is set, it won't go away while the
4757 * buffer is dirty or in writeback, and it also won't
4758 * go away while we have the reference count on the
4761 * We can't just set the ref bit without bumping the
4762 * ref on the eb because free_extent_buffer might
4763 * see the ref bit and try to clear it. If this happens
4764 * free_extent_buffer might end up dropping our original
4765 * ref by mistake and freeing the page before we are able
4766 * to add one more ref.
4768 * So bump the ref count first, then set the bit. If someone
4769 * beat us to it, drop the ref we added.
4771 refs = atomic_read(&eb->refs);
4772 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4775 spin_lock(&eb->refs_lock);
4776 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4777 atomic_inc(&eb->refs);
4778 spin_unlock(&eb->refs_lock);
4781 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
4782 struct page *accessed)
4784 unsigned long num_pages, i;
4786 check_buffer_tree_ref(eb);
4788 num_pages = num_extent_pages(eb->start, eb->len);
4789 for (i = 0; i < num_pages; i++) {
4790 struct page *p = eb->pages[i];
4793 mark_page_accessed(p);
4797 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
4800 struct extent_buffer *eb;
4803 eb = radix_tree_lookup(&fs_info->buffer_radix,
4804 start >> PAGE_SHIFT);
4805 if (eb && atomic_inc_not_zero(&eb->refs)) {
4808 * Lock our eb's refs_lock to avoid races with
4809 * free_extent_buffer. When we get our eb it might be flagged
4810 * with EXTENT_BUFFER_STALE and another task running
4811 * free_extent_buffer might have seen that flag set,
4812 * eb->refs == 2, that the buffer isn't under IO (dirty and
4813 * writeback flags not set) and it's still in the tree (flag
4814 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4815 * of decrementing the extent buffer's reference count twice.
4816 * So here we could race and increment the eb's reference count,
4817 * clear its stale flag, mark it as dirty and drop our reference
4818 * before the other task finishes executing free_extent_buffer,
4819 * which would later result in an attempt to free an extent
4820 * buffer that is dirty.
4822 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
4823 spin_lock(&eb->refs_lock);
4824 spin_unlock(&eb->refs_lock);
4826 mark_extent_buffer_accessed(eb, NULL);
4834 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4835 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
4838 struct extent_buffer *eb, *exists = NULL;
4841 eb = find_extent_buffer(fs_info, start);
4844 eb = alloc_dummy_extent_buffer(fs_info, start);
4847 eb->fs_info = fs_info;
4849 ret = radix_tree_preload(GFP_NOFS);
4852 spin_lock(&fs_info->buffer_lock);
4853 ret = radix_tree_insert(&fs_info->buffer_radix,
4854 start >> PAGE_SHIFT, eb);
4855 spin_unlock(&fs_info->buffer_lock);
4856 radix_tree_preload_end();
4857 if (ret == -EEXIST) {
4858 exists = find_extent_buffer(fs_info, start);
4864 check_buffer_tree_ref(eb);
4865 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4868 * We will free dummy extent buffer's if they come into
4869 * free_extent_buffer with a ref count of 2, but if we are using this we
4870 * want the buffers to stay in memory until we're done with them, so
4871 * bump the ref count again.
4873 atomic_inc(&eb->refs);
4876 btrfs_release_extent_buffer(eb);
4881 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
4884 unsigned long len = fs_info->nodesize;
4885 unsigned long num_pages = num_extent_pages(start, len);
4887 unsigned long index = start >> PAGE_SHIFT;
4888 struct extent_buffer *eb;
4889 struct extent_buffer *exists = NULL;
4891 struct address_space *mapping = fs_info->btree_inode->i_mapping;
4895 if (!IS_ALIGNED(start, fs_info->sectorsize)) {
4896 btrfs_err(fs_info, "bad tree block start %llu", start);
4897 return ERR_PTR(-EINVAL);
4900 eb = find_extent_buffer(fs_info, start);
4904 eb = __alloc_extent_buffer(fs_info, start, len);
4906 return ERR_PTR(-ENOMEM);
4908 for (i = 0; i < num_pages; i++, index++) {
4909 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
4911 exists = ERR_PTR(-ENOMEM);
4915 spin_lock(&mapping->private_lock);
4916 if (PagePrivate(p)) {
4918 * We could have already allocated an eb for this page
4919 * and attached one so lets see if we can get a ref on
4920 * the existing eb, and if we can we know it's good and
4921 * we can just return that one, else we know we can just
4922 * overwrite page->private.
4924 exists = (struct extent_buffer *)p->private;
4925 if (atomic_inc_not_zero(&exists->refs)) {
4926 spin_unlock(&mapping->private_lock);
4929 mark_extent_buffer_accessed(exists, p);
4935 * Do this so attach doesn't complain and we need to
4936 * drop the ref the old guy had.
4938 ClearPagePrivate(p);
4939 WARN_ON(PageDirty(p));
4942 attach_extent_buffer_page(eb, p);
4943 spin_unlock(&mapping->private_lock);
4944 WARN_ON(PageDirty(p));
4946 if (!PageUptodate(p))
4950 * see below about how we avoid a nasty race with release page
4951 * and why we unlock later
4955 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4957 ret = radix_tree_preload(GFP_NOFS);
4959 exists = ERR_PTR(ret);
4963 spin_lock(&fs_info->buffer_lock);
4964 ret = radix_tree_insert(&fs_info->buffer_radix,
4965 start >> PAGE_SHIFT, eb);
4966 spin_unlock(&fs_info->buffer_lock);
4967 radix_tree_preload_end();
4968 if (ret == -EEXIST) {
4969 exists = find_extent_buffer(fs_info, start);
4975 /* add one reference for the tree */
4976 check_buffer_tree_ref(eb);
4977 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4980 * there is a race where release page may have
4981 * tried to find this extent buffer in the radix
4982 * but failed. It will tell the VM it is safe to
4983 * reclaim the, and it will clear the page private bit.
4984 * We must make sure to set the page private bit properly
4985 * after the extent buffer is in the radix tree so
4986 * it doesn't get lost
4988 SetPageChecked(eb->pages[0]);
4989 for (i = 1; i < num_pages; i++) {
4991 ClearPageChecked(p);
4994 unlock_page(eb->pages[0]);
4998 WARN_ON(!atomic_dec_and_test(&eb->refs));
4999 for (i = 0; i < num_pages; i++) {
5001 unlock_page(eb->pages[i]);
5004 btrfs_release_extent_buffer(eb);
5008 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5010 struct extent_buffer *eb =
5011 container_of(head, struct extent_buffer, rcu_head);
5013 __free_extent_buffer(eb);
5016 /* Expects to have eb->eb_lock already held */
5017 static int release_extent_buffer(struct extent_buffer *eb)
5019 WARN_ON(atomic_read(&eb->refs) == 0);
5020 if (atomic_dec_and_test(&eb->refs)) {
5021 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5022 struct btrfs_fs_info *fs_info = eb->fs_info;
5024 spin_unlock(&eb->refs_lock);
5026 spin_lock(&fs_info->buffer_lock);
5027 radix_tree_delete(&fs_info->buffer_radix,
5028 eb->start >> PAGE_SHIFT);
5029 spin_unlock(&fs_info->buffer_lock);
5031 spin_unlock(&eb->refs_lock);
5034 /* Should be safe to release our pages at this point */
5035 btrfs_release_extent_buffer_page(eb);
5036 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5037 if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) {
5038 __free_extent_buffer(eb);
5042 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5045 spin_unlock(&eb->refs_lock);
5050 void free_extent_buffer(struct extent_buffer *eb)
5058 refs = atomic_read(&eb->refs);
5061 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5066 spin_lock(&eb->refs_lock);
5067 if (atomic_read(&eb->refs) == 2 &&
5068 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
5069 atomic_dec(&eb->refs);
5071 if (atomic_read(&eb->refs) == 2 &&
5072 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5073 !extent_buffer_under_io(eb) &&
5074 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5075 atomic_dec(&eb->refs);
5078 * I know this is terrible, but it's temporary until we stop tracking
5079 * the uptodate bits and such for the extent buffers.
5081 release_extent_buffer(eb);
5084 void free_extent_buffer_stale(struct extent_buffer *eb)
5089 spin_lock(&eb->refs_lock);
5090 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5092 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5093 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5094 atomic_dec(&eb->refs);
5095 release_extent_buffer(eb);
5098 void clear_extent_buffer_dirty(struct extent_buffer *eb)
5101 unsigned long num_pages;
5104 num_pages = num_extent_pages(eb->start, eb->len);
5106 for (i = 0; i < num_pages; i++) {
5107 page = eb->pages[i];
5108 if (!PageDirty(page))
5112 WARN_ON(!PagePrivate(page));
5114 clear_page_dirty_for_io(page);
5115 spin_lock_irq(&page->mapping->tree_lock);
5116 if (!PageDirty(page)) {
5117 radix_tree_tag_clear(&page->mapping->page_tree,
5119 PAGECACHE_TAG_DIRTY);
5121 spin_unlock_irq(&page->mapping->tree_lock);
5122 ClearPageError(page);
5125 WARN_ON(atomic_read(&eb->refs) == 0);
5128 int set_extent_buffer_dirty(struct extent_buffer *eb)
5131 unsigned long num_pages;
5134 check_buffer_tree_ref(eb);
5136 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5138 num_pages = num_extent_pages(eb->start, eb->len);
5139 WARN_ON(atomic_read(&eb->refs) == 0);
5140 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5142 for (i = 0; i < num_pages; i++)
5143 set_page_dirty(eb->pages[i]);
5147 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5151 unsigned long num_pages;
5153 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5154 num_pages = num_extent_pages(eb->start, eb->len);
5155 for (i = 0; i < num_pages; i++) {
5156 page = eb->pages[i];
5158 ClearPageUptodate(page);
5162 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5166 unsigned long num_pages;
5168 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5169 num_pages = num_extent_pages(eb->start, eb->len);
5170 for (i = 0; i < num_pages; i++) {
5171 page = eb->pages[i];
5172 SetPageUptodate(page);
5176 int extent_buffer_uptodate(struct extent_buffer *eb)
5178 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5181 int read_extent_buffer_pages(struct extent_io_tree *tree,
5182 struct extent_buffer *eb, int wait,
5183 get_extent_t *get_extent, int mirror_num)
5189 int locked_pages = 0;
5190 int all_uptodate = 1;
5191 unsigned long num_pages;
5192 unsigned long num_reads = 0;
5193 struct bio *bio = NULL;
5194 unsigned long bio_flags = 0;
5196 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5199 num_pages = num_extent_pages(eb->start, eb->len);
5200 for (i = 0; i < num_pages; i++) {
5201 page = eb->pages[i];
5202 if (wait == WAIT_NONE) {
5203 if (!trylock_page(page))
5211 * We need to firstly lock all pages to make sure that
5212 * the uptodate bit of our pages won't be affected by
5213 * clear_extent_buffer_uptodate().
5215 for (i = 0; i < num_pages; i++) {
5216 page = eb->pages[i];
5217 if (!PageUptodate(page)) {
5224 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5228 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5229 eb->read_mirror = 0;
5230 atomic_set(&eb->io_pages, num_reads);
5231 for (i = 0; i < num_pages; i++) {
5232 page = eb->pages[i];
5234 if (!PageUptodate(page)) {
5236 atomic_dec(&eb->io_pages);
5241 ClearPageError(page);
5242 err = __extent_read_full_page(tree, page,
5244 mirror_num, &bio_flags,
5249 * We use &bio in above __extent_read_full_page,
5250 * so we ensure that if it returns error, the
5251 * current page fails to add itself to bio and
5252 * it's been unlocked.
5254 * We must dec io_pages by ourselves.
5256 atomic_dec(&eb->io_pages);
5264 err = submit_one_bio(bio, mirror_num, bio_flags);
5269 if (ret || wait != WAIT_COMPLETE)
5272 for (i = 0; i < num_pages; i++) {
5273 page = eb->pages[i];
5274 wait_on_page_locked(page);
5275 if (!PageUptodate(page))
5282 while (locked_pages > 0) {
5284 page = eb->pages[locked_pages];
5290 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
5291 unsigned long start,
5298 char *dst = (char *)dstv;
5299 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5300 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5302 WARN_ON(start > eb->len);
5303 WARN_ON(start + len > eb->start + eb->len);
5305 offset = (start_offset + start) & (PAGE_SIZE - 1);
5308 page = eb->pages[i];
5310 cur = min(len, (PAGE_SIZE - offset));
5311 kaddr = page_address(page);
5312 memcpy(dst, kaddr + offset, cur);
5321 int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv,
5322 unsigned long start,
5329 char __user *dst = (char __user *)dstv;
5330 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5331 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5334 WARN_ON(start > eb->len);
5335 WARN_ON(start + len > eb->start + eb->len);
5337 offset = (start_offset + start) & (PAGE_SIZE - 1);
5340 page = eb->pages[i];
5342 cur = min(len, (PAGE_SIZE - offset));
5343 kaddr = page_address(page);
5344 if (copy_to_user(dst, kaddr + offset, cur)) {
5359 * return 0 if the item is found within a page.
5360 * return 1 if the item spans two pages.
5361 * return -EINVAL otherwise.
5363 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
5364 unsigned long min_len, char **map,
5365 unsigned long *map_start,
5366 unsigned long *map_len)
5368 size_t offset = start & (PAGE_SIZE - 1);
5371 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5372 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5373 unsigned long end_i = (start_offset + start + min_len - 1) >>
5380 offset = start_offset;
5384 *map_start = ((u64)i << PAGE_SHIFT) - start_offset;
5387 if (start + min_len > eb->len) {
5388 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5389 eb->start, eb->len, start, min_len);
5394 kaddr = page_address(p);
5395 *map = kaddr + offset;
5396 *map_len = PAGE_SIZE - offset;
5400 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
5401 unsigned long start,
5408 char *ptr = (char *)ptrv;
5409 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5410 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5413 WARN_ON(start > eb->len);
5414 WARN_ON(start + len > eb->start + eb->len);
5416 offset = (start_offset + start) & (PAGE_SIZE - 1);
5419 page = eb->pages[i];
5421 cur = min(len, (PAGE_SIZE - offset));
5423 kaddr = page_address(page);
5424 ret = memcmp(ptr, kaddr + offset, cur);
5436 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
5441 WARN_ON(!PageUptodate(eb->pages[0]));
5442 kaddr = page_address(eb->pages[0]);
5443 memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
5447 void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)
5451 WARN_ON(!PageUptodate(eb->pages[0]));
5452 kaddr = page_address(eb->pages[0]);
5453 memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
5457 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
5458 unsigned long start, unsigned long len)
5464 char *src = (char *)srcv;
5465 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5466 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5468 WARN_ON(start > eb->len);
5469 WARN_ON(start + len > eb->start + eb->len);
5471 offset = (start_offset + start) & (PAGE_SIZE - 1);
5474 page = eb->pages[i];
5475 WARN_ON(!PageUptodate(page));
5477 cur = min(len, PAGE_SIZE - offset);
5478 kaddr = page_address(page);
5479 memcpy(kaddr + offset, src, cur);
5488 void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
5495 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5496 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5498 WARN_ON(start > eb->len);
5499 WARN_ON(start + len > eb->start + eb->len);
5501 offset = (start_offset + start) & (PAGE_SIZE - 1);
5504 page = eb->pages[i];
5505 WARN_ON(!PageUptodate(page));
5507 cur = min(len, PAGE_SIZE - offset);
5508 kaddr = page_address(page);
5509 memset(kaddr + offset, 0, cur);
5517 void copy_extent_buffer_full(struct extent_buffer *dst,
5518 struct extent_buffer *src)
5523 ASSERT(dst->len == src->len);
5525 num_pages = num_extent_pages(dst->start, dst->len);
5526 for (i = 0; i < num_pages; i++)
5527 copy_page(page_address(dst->pages[i]),
5528 page_address(src->pages[i]));
5531 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5532 unsigned long dst_offset, unsigned long src_offset,
5535 u64 dst_len = dst->len;
5540 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5541 unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
5543 WARN_ON(src->len != dst_len);
5545 offset = (start_offset + dst_offset) &
5549 page = dst->pages[i];
5550 WARN_ON(!PageUptodate(page));
5552 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5554 kaddr = page_address(page);
5555 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5564 void le_bitmap_set(u8 *map, unsigned int start, int len)
5566 u8 *p = map + BIT_BYTE(start);
5567 const unsigned int size = start + len;
5568 int bits_to_set = BITS_PER_BYTE - (start % BITS_PER_BYTE);
5569 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(start);
5571 while (len - bits_to_set >= 0) {
5574 bits_to_set = BITS_PER_BYTE;
5579 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5584 void le_bitmap_clear(u8 *map, unsigned int start, int len)
5586 u8 *p = map + BIT_BYTE(start);
5587 const unsigned int size = start + len;
5588 int bits_to_clear = BITS_PER_BYTE - (start % BITS_PER_BYTE);
5589 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(start);
5591 while (len - bits_to_clear >= 0) {
5592 *p &= ~mask_to_clear;
5593 len -= bits_to_clear;
5594 bits_to_clear = BITS_PER_BYTE;
5599 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5600 *p &= ~mask_to_clear;
5605 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5607 * @eb: the extent buffer
5608 * @start: offset of the bitmap item in the extent buffer
5610 * @page_index: return index of the page in the extent buffer that contains the
5612 * @page_offset: return offset into the page given by page_index
5614 * This helper hides the ugliness of finding the byte in an extent buffer which
5615 * contains a given bit.
5617 static inline void eb_bitmap_offset(struct extent_buffer *eb,
5618 unsigned long start, unsigned long nr,
5619 unsigned long *page_index,
5620 size_t *page_offset)
5622 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5623 size_t byte_offset = BIT_BYTE(nr);
5627 * The byte we want is the offset of the extent buffer + the offset of
5628 * the bitmap item in the extent buffer + the offset of the byte in the
5631 offset = start_offset + start + byte_offset;
5633 *page_index = offset >> PAGE_SHIFT;
5634 *page_offset = offset & (PAGE_SIZE - 1);
5638 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5639 * @eb: the extent buffer
5640 * @start: offset of the bitmap item in the extent buffer
5641 * @nr: bit number to test
5643 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
5651 eb_bitmap_offset(eb, start, nr, &i, &offset);
5652 page = eb->pages[i];
5653 WARN_ON(!PageUptodate(page));
5654 kaddr = page_address(page);
5655 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5659 * extent_buffer_bitmap_set - set an area of a bitmap
5660 * @eb: the extent buffer
5661 * @start: offset of the bitmap item in the extent buffer
5662 * @pos: bit number of the first bit
5663 * @len: number of bits to set
5665 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
5666 unsigned long pos, unsigned long len)
5672 const unsigned int size = pos + len;
5673 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5674 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5676 eb_bitmap_offset(eb, start, pos, &i, &offset);
5677 page = eb->pages[i];
5678 WARN_ON(!PageUptodate(page));
5679 kaddr = page_address(page);
5681 while (len >= bits_to_set) {
5682 kaddr[offset] |= mask_to_set;
5684 bits_to_set = BITS_PER_BYTE;
5686 if (++offset >= PAGE_SIZE && len > 0) {
5688 page = eb->pages[++i];
5689 WARN_ON(!PageUptodate(page));
5690 kaddr = page_address(page);
5694 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5695 kaddr[offset] |= mask_to_set;
5701 * extent_buffer_bitmap_clear - clear an area of a bitmap
5702 * @eb: the extent buffer
5703 * @start: offset of the bitmap item in the extent buffer
5704 * @pos: bit number of the first bit
5705 * @len: number of bits to clear
5707 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
5708 unsigned long pos, unsigned long len)
5714 const unsigned int size = pos + len;
5715 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5716 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5718 eb_bitmap_offset(eb, start, pos, &i, &offset);
5719 page = eb->pages[i];
5720 WARN_ON(!PageUptodate(page));
5721 kaddr = page_address(page);
5723 while (len >= bits_to_clear) {
5724 kaddr[offset] &= ~mask_to_clear;
5725 len -= bits_to_clear;
5726 bits_to_clear = BITS_PER_BYTE;
5728 if (++offset >= PAGE_SIZE && len > 0) {
5730 page = eb->pages[++i];
5731 WARN_ON(!PageUptodate(page));
5732 kaddr = page_address(page);
5736 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5737 kaddr[offset] &= ~mask_to_clear;
5741 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5743 unsigned long distance = (src > dst) ? src - dst : dst - src;
5744 return distance < len;
5747 static void copy_pages(struct page *dst_page, struct page *src_page,
5748 unsigned long dst_off, unsigned long src_off,
5751 char *dst_kaddr = page_address(dst_page);
5753 int must_memmove = 0;
5755 if (dst_page != src_page) {
5756 src_kaddr = page_address(src_page);
5758 src_kaddr = dst_kaddr;
5759 if (areas_overlap(src_off, dst_off, len))
5764 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5766 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5769 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5770 unsigned long src_offset, unsigned long len)
5772 struct btrfs_fs_info *fs_info = dst->fs_info;
5774 size_t dst_off_in_page;
5775 size_t src_off_in_page;
5776 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5777 unsigned long dst_i;
5778 unsigned long src_i;
5780 if (src_offset + len > dst->len) {
5782 "memmove bogus src_offset %lu move len %lu dst len %lu",
5783 src_offset, len, dst->len);
5786 if (dst_offset + len > dst->len) {
5788 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5789 dst_offset, len, dst->len);
5794 dst_off_in_page = (start_offset + dst_offset) &
5796 src_off_in_page = (start_offset + src_offset) &
5799 dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
5800 src_i = (start_offset + src_offset) >> PAGE_SHIFT;
5802 cur = min(len, (unsigned long)(PAGE_SIZE -
5804 cur = min_t(unsigned long, cur,
5805 (unsigned long)(PAGE_SIZE - dst_off_in_page));
5807 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5808 dst_off_in_page, src_off_in_page, cur);
5816 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5817 unsigned long src_offset, unsigned long len)
5819 struct btrfs_fs_info *fs_info = dst->fs_info;
5821 size_t dst_off_in_page;
5822 size_t src_off_in_page;
5823 unsigned long dst_end = dst_offset + len - 1;
5824 unsigned long src_end = src_offset + len - 1;
5825 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5826 unsigned long dst_i;
5827 unsigned long src_i;
5829 if (src_offset + len > dst->len) {
5831 "memmove bogus src_offset %lu move len %lu len %lu",
5832 src_offset, len, dst->len);
5835 if (dst_offset + len > dst->len) {
5837 "memmove bogus dst_offset %lu move len %lu len %lu",
5838 dst_offset, len, dst->len);
5841 if (dst_offset < src_offset) {
5842 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5846 dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
5847 src_i = (start_offset + src_end) >> PAGE_SHIFT;
5849 dst_off_in_page = (start_offset + dst_end) &
5851 src_off_in_page = (start_offset + src_end) &
5854 cur = min_t(unsigned long, len, src_off_in_page + 1);
5855 cur = min(cur, dst_off_in_page + 1);
5856 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5857 dst_off_in_page - cur + 1,
5858 src_off_in_page - cur + 1, cur);
5866 int try_release_extent_buffer(struct page *page)
5868 struct extent_buffer *eb;
5871 * We need to make sure nobody is attaching this page to an eb right
5874 spin_lock(&page->mapping->private_lock);
5875 if (!PagePrivate(page)) {
5876 spin_unlock(&page->mapping->private_lock);
5880 eb = (struct extent_buffer *)page->private;
5884 * This is a little awful but should be ok, we need to make sure that
5885 * the eb doesn't disappear out from under us while we're looking at
5888 spin_lock(&eb->refs_lock);
5889 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5890 spin_unlock(&eb->refs_lock);
5891 spin_unlock(&page->mapping->private_lock);
5894 spin_unlock(&page->mapping->private_lock);
5897 * If tree ref isn't set then we know the ref on this eb is a real ref,
5898 * so just return, this page will likely be freed soon anyway.
5900 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5901 spin_unlock(&eb->refs_lock);
5905 return release_extent_buffer(eb);