1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/bitops.h>
4 #include <linux/slab.h>
7 #include <linux/pagemap.h>
8 #include <linux/page-flags.h>
9 #include <linux/spinlock.h>
10 #include <linux/blkdev.h>
11 #include <linux/swap.h>
12 #include <linux/writeback.h>
13 #include <linux/pagevec.h>
14 #include <linux/prefetch.h>
15 #include <linux/cleancache.h>
16 #include "extent_io.h"
17 #include "extent_map.h"
19 #include "btrfs_inode.h"
21 #include "check-integrity.h"
23 #include "rcu-string.h"
27 static struct kmem_cache *extent_state_cache;
28 static struct kmem_cache *extent_buffer_cache;
29 static struct bio_set *btrfs_bioset;
31 static inline bool extent_state_in_tree(const struct extent_state *state)
33 return !RB_EMPTY_NODE(&state->rb_node);
36 #ifdef CONFIG_BTRFS_DEBUG
37 static LIST_HEAD(buffers);
38 static LIST_HEAD(states);
40 static DEFINE_SPINLOCK(leak_lock);
43 void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
47 spin_lock_irqsave(&leak_lock, flags);
49 spin_unlock_irqrestore(&leak_lock, flags);
53 void btrfs_leak_debug_del(struct list_head *entry)
57 spin_lock_irqsave(&leak_lock, flags);
59 spin_unlock_irqrestore(&leak_lock, flags);
63 void btrfs_leak_debug_check(void)
65 struct extent_state *state;
66 struct extent_buffer *eb;
68 while (!list_empty(&states)) {
69 state = list_entry(states.next, struct extent_state, leak_list);
70 pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
71 state->start, state->end, state->state,
72 extent_state_in_tree(state),
73 refcount_read(&state->refs));
74 list_del(&state->leak_list);
75 kmem_cache_free(extent_state_cache, state);
78 while (!list_empty(&buffers)) {
79 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
80 pr_err("BTRFS: buffer leak start %llu len %lu refs %d bflags %lu\n",
81 eb->start, eb->len, atomic_read(&eb->refs), eb->bflags);
82 list_del(&eb->leak_list);
83 kmem_cache_free(extent_buffer_cache, eb);
87 #define btrfs_debug_check_extent_io_range(tree, start, end) \
88 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
89 static inline void __btrfs_debug_check_extent_io_range(const char *caller,
90 struct extent_io_tree *tree, u64 start, u64 end)
92 if (tree->ops && tree->ops->check_extent_io_range)
93 tree->ops->check_extent_io_range(tree->private_data, caller,
97 #define btrfs_leak_debug_add(new, head) do {} while (0)
98 #define btrfs_leak_debug_del(entry) do {} while (0)
99 #define btrfs_leak_debug_check() do {} while (0)
100 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
103 #define BUFFER_LRU_MAX 64
108 struct rb_node rb_node;
111 struct extent_page_data {
113 struct extent_io_tree *tree;
114 /* tells writepage not to lock the state bits for this range
115 * it still does the unlocking
117 unsigned int extent_locked:1;
119 /* tells the submit_bio code to use REQ_SYNC */
120 unsigned int sync_io:1;
123 static int add_extent_changeset(struct extent_state *state, unsigned bits,
124 struct extent_changeset *changeset,
131 if (set && (state->state & bits) == bits)
133 if (!set && (state->state & bits) == 0)
135 changeset->bytes_changed += state->end - state->start + 1;
136 ret = ulist_add(&changeset->range_changed, state->start, state->end,
141 static void flush_write_bio(struct extent_page_data *epd);
143 static inline struct btrfs_fs_info *
144 tree_fs_info(struct extent_io_tree *tree)
147 return tree->ops->tree_fs_info(tree->private_data);
151 int __init extent_io_init(void)
153 extent_state_cache = kmem_cache_create("btrfs_extent_state",
154 sizeof(struct extent_state), 0,
155 SLAB_MEM_SPREAD, NULL);
156 if (!extent_state_cache)
159 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
160 sizeof(struct extent_buffer), 0,
161 SLAB_MEM_SPREAD, NULL);
162 if (!extent_buffer_cache)
163 goto free_state_cache;
165 btrfs_bioset = bioset_create(BIO_POOL_SIZE,
166 offsetof(struct btrfs_io_bio, bio),
169 goto free_buffer_cache;
171 if (bioset_integrity_create(btrfs_bioset, BIO_POOL_SIZE))
177 bioset_free(btrfs_bioset);
181 kmem_cache_destroy(extent_buffer_cache);
182 extent_buffer_cache = NULL;
185 kmem_cache_destroy(extent_state_cache);
186 extent_state_cache = NULL;
190 void __cold extent_io_exit(void)
192 btrfs_leak_debug_check();
195 * Make sure all delayed rcu free are flushed before we
199 kmem_cache_destroy(extent_state_cache);
200 kmem_cache_destroy(extent_buffer_cache);
202 bioset_free(btrfs_bioset);
205 void extent_io_tree_init(struct extent_io_tree *tree,
208 tree->state = RB_ROOT;
210 tree->dirty_bytes = 0;
211 spin_lock_init(&tree->lock);
212 tree->private_data = private_data;
215 static struct extent_state *alloc_extent_state(gfp_t mask)
217 struct extent_state *state;
220 * The given mask might be not appropriate for the slab allocator,
221 * drop the unsupported bits
223 mask &= ~(__GFP_DMA32|__GFP_HIGHMEM);
224 state = kmem_cache_alloc(extent_state_cache, mask);
228 state->failrec = NULL;
229 RB_CLEAR_NODE(&state->rb_node);
230 btrfs_leak_debug_add(&state->leak_list, &states);
231 refcount_set(&state->refs, 1);
232 init_waitqueue_head(&state->wq);
233 trace_alloc_extent_state(state, mask, _RET_IP_);
237 void free_extent_state(struct extent_state *state)
241 if (refcount_dec_and_test(&state->refs)) {
242 WARN_ON(extent_state_in_tree(state));
243 btrfs_leak_debug_del(&state->leak_list);
244 trace_free_extent_state(state, _RET_IP_);
245 kmem_cache_free(extent_state_cache, state);
249 static struct rb_node *tree_insert(struct rb_root *root,
250 struct rb_node *search_start,
252 struct rb_node *node,
253 struct rb_node ***p_in,
254 struct rb_node **parent_in)
257 struct rb_node *parent = NULL;
258 struct tree_entry *entry;
260 if (p_in && parent_in) {
266 p = search_start ? &search_start : &root->rb_node;
269 entry = rb_entry(parent, struct tree_entry, rb_node);
271 if (offset < entry->start)
273 else if (offset > entry->end)
280 rb_link_node(node, parent, p);
281 rb_insert_color(node, root);
285 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
286 struct rb_node **prev_ret,
287 struct rb_node **next_ret,
288 struct rb_node ***p_ret,
289 struct rb_node **parent_ret)
291 struct rb_root *root = &tree->state;
292 struct rb_node **n = &root->rb_node;
293 struct rb_node *prev = NULL;
294 struct rb_node *orig_prev = NULL;
295 struct tree_entry *entry;
296 struct tree_entry *prev_entry = NULL;
300 entry = rb_entry(prev, struct tree_entry, rb_node);
303 if (offset < entry->start)
305 else if (offset > entry->end)
318 while (prev && offset > prev_entry->end) {
319 prev = rb_next(prev);
320 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
327 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
328 while (prev && offset < prev_entry->start) {
329 prev = rb_prev(prev);
330 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
337 static inline struct rb_node *
338 tree_search_for_insert(struct extent_io_tree *tree,
340 struct rb_node ***p_ret,
341 struct rb_node **parent_ret)
343 struct rb_node *prev = NULL;
346 ret = __etree_search(tree, offset, &prev, NULL, p_ret, parent_ret);
352 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
355 return tree_search_for_insert(tree, offset, NULL, NULL);
358 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
359 struct extent_state *other)
361 if (tree->ops && tree->ops->merge_extent_hook)
362 tree->ops->merge_extent_hook(tree->private_data, new, other);
366 * utility function to look for merge candidates inside a given range.
367 * Any extents with matching state are merged together into a single
368 * extent in the tree. Extents with EXTENT_IO in their state field
369 * are not merged because the end_io handlers need to be able to do
370 * operations on them without sleeping (or doing allocations/splits).
372 * This should be called with the tree lock held.
374 static void merge_state(struct extent_io_tree *tree,
375 struct extent_state *state)
377 struct extent_state *other;
378 struct rb_node *other_node;
380 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
383 other_node = rb_prev(&state->rb_node);
385 other = rb_entry(other_node, struct extent_state, rb_node);
386 if (other->end == state->start - 1 &&
387 other->state == state->state) {
388 merge_cb(tree, state, other);
389 state->start = other->start;
390 rb_erase(&other->rb_node, &tree->state);
391 RB_CLEAR_NODE(&other->rb_node);
392 free_extent_state(other);
395 other_node = rb_next(&state->rb_node);
397 other = rb_entry(other_node, struct extent_state, rb_node);
398 if (other->start == state->end + 1 &&
399 other->state == state->state) {
400 merge_cb(tree, state, other);
401 state->end = other->end;
402 rb_erase(&other->rb_node, &tree->state);
403 RB_CLEAR_NODE(&other->rb_node);
404 free_extent_state(other);
409 static void set_state_cb(struct extent_io_tree *tree,
410 struct extent_state *state, unsigned *bits)
412 if (tree->ops && tree->ops->set_bit_hook)
413 tree->ops->set_bit_hook(tree->private_data, state, bits);
416 static void clear_state_cb(struct extent_io_tree *tree,
417 struct extent_state *state, unsigned *bits)
419 if (tree->ops && tree->ops->clear_bit_hook)
420 tree->ops->clear_bit_hook(tree->private_data, state, bits);
423 static void set_state_bits(struct extent_io_tree *tree,
424 struct extent_state *state, unsigned *bits,
425 struct extent_changeset *changeset);
428 * insert an extent_state struct into the tree. 'bits' are set on the
429 * struct before it is inserted.
431 * This may return -EEXIST if the extent is already there, in which case the
432 * state struct is freed.
434 * The tree lock is not taken internally. This is a utility function and
435 * probably isn't what you want to call (see set/clear_extent_bit).
437 static int insert_state(struct extent_io_tree *tree,
438 struct extent_state *state, u64 start, u64 end,
440 struct rb_node **parent,
441 unsigned *bits, struct extent_changeset *changeset)
443 struct rb_node *node;
446 WARN(1, KERN_ERR "BTRFS: end < start %llu %llu\n",
448 state->start = start;
451 set_state_bits(tree, state, bits, changeset);
453 node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
455 struct extent_state *found;
456 found = rb_entry(node, struct extent_state, rb_node);
457 pr_err("BTRFS: found node %llu %llu on insert of %llu %llu\n",
458 found->start, found->end, start, end);
461 merge_state(tree, state);
465 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
468 if (tree->ops && tree->ops->split_extent_hook)
469 tree->ops->split_extent_hook(tree->private_data, orig, split);
473 * split a given extent state struct in two, inserting the preallocated
474 * struct 'prealloc' as the newly created second half. 'split' indicates an
475 * offset inside 'orig' where it should be split.
478 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
479 * are two extent state structs in the tree:
480 * prealloc: [orig->start, split - 1]
481 * orig: [ split, orig->end ]
483 * The tree locks are not taken by this function. They need to be held
486 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
487 struct extent_state *prealloc, u64 split)
489 struct rb_node *node;
491 split_cb(tree, orig, split);
493 prealloc->start = orig->start;
494 prealloc->end = split - 1;
495 prealloc->state = orig->state;
498 node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
499 &prealloc->rb_node, NULL, NULL);
501 free_extent_state(prealloc);
507 static struct extent_state *next_state(struct extent_state *state)
509 struct rb_node *next = rb_next(&state->rb_node);
511 return rb_entry(next, struct extent_state, rb_node);
517 * utility function to clear some bits in an extent state struct.
518 * it will optionally wake up any one waiting on this state (wake == 1).
520 * If no bits are set on the state struct after clearing things, the
521 * struct is freed and removed from the tree
523 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
524 struct extent_state *state,
525 unsigned *bits, int wake,
526 struct extent_changeset *changeset)
528 struct extent_state *next;
529 unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
532 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
533 u64 range = state->end - state->start + 1;
534 WARN_ON(range > tree->dirty_bytes);
535 tree->dirty_bytes -= range;
537 clear_state_cb(tree, state, bits);
538 ret = add_extent_changeset(state, bits_to_clear, changeset, 0);
540 state->state &= ~bits_to_clear;
543 if (state->state == 0) {
544 next = next_state(state);
545 if (extent_state_in_tree(state)) {
546 rb_erase(&state->rb_node, &tree->state);
547 RB_CLEAR_NODE(&state->rb_node);
548 free_extent_state(state);
553 merge_state(tree, state);
554 next = next_state(state);
559 static struct extent_state *
560 alloc_extent_state_atomic(struct extent_state *prealloc)
563 prealloc = alloc_extent_state(GFP_ATOMIC);
568 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
570 btrfs_panic(tree_fs_info(tree), err,
571 "Locking error: Extent tree was modified by another thread while locked.");
575 * clear some bits on a range in the tree. This may require splitting
576 * or inserting elements in the tree, so the gfp mask is used to
577 * indicate which allocations or sleeping are allowed.
579 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
580 * the given range from the tree regardless of state (ie for truncate).
582 * the range [start, end] is inclusive.
584 * This takes the tree lock, and returns 0 on success and < 0 on error.
586 int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
587 unsigned bits, int wake, int delete,
588 struct extent_state **cached_state,
589 gfp_t mask, struct extent_changeset *changeset)
591 struct extent_state *state;
592 struct extent_state *cached;
593 struct extent_state *prealloc = NULL;
594 struct rb_node *node;
599 btrfs_debug_check_extent_io_range(tree, start, end);
601 if (bits & EXTENT_DELALLOC)
602 bits |= EXTENT_NORESERVE;
605 bits |= ~EXTENT_CTLBITS;
606 bits |= EXTENT_FIRST_DELALLOC;
608 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
611 if (!prealloc && gfpflags_allow_blocking(mask)) {
613 * Don't care for allocation failure here because we might end
614 * up not needing the pre-allocated extent state at all, which
615 * is the case if we only have in the tree extent states that
616 * cover our input range and don't cover too any other range.
617 * If we end up needing a new extent state we allocate it later.
619 prealloc = alloc_extent_state(mask);
622 spin_lock(&tree->lock);
624 cached = *cached_state;
627 *cached_state = NULL;
631 if (cached && extent_state_in_tree(cached) &&
632 cached->start <= start && cached->end > start) {
634 refcount_dec(&cached->refs);
639 free_extent_state(cached);
642 * this search will find the extents that end after
645 node = tree_search(tree, start);
648 state = rb_entry(node, struct extent_state, rb_node);
650 if (state->start > end)
652 WARN_ON(state->end < start);
653 last_end = state->end;
655 /* the state doesn't have the wanted bits, go ahead */
656 if (!(state->state & bits)) {
657 state = next_state(state);
662 * | ---- desired range ---- |
664 * | ------------- state -------------- |
666 * We need to split the extent we found, and may flip
667 * bits on second half.
669 * If the extent we found extends past our range, we
670 * just split and search again. It'll get split again
671 * the next time though.
673 * If the extent we found is inside our range, we clear
674 * the desired bit on it.
677 if (state->start < start) {
678 prealloc = alloc_extent_state_atomic(prealloc);
680 err = split_state(tree, state, prealloc, start);
682 extent_io_tree_panic(tree, err);
687 if (state->end <= end) {
688 state = clear_state_bit(tree, state, &bits, wake,
695 * | ---- desired range ---- |
697 * We need to split the extent, and clear the bit
700 if (state->start <= end && state->end > end) {
701 prealloc = alloc_extent_state_atomic(prealloc);
703 err = split_state(tree, state, prealloc, end + 1);
705 extent_io_tree_panic(tree, err);
710 clear_state_bit(tree, prealloc, &bits, wake, changeset);
716 state = clear_state_bit(tree, state, &bits, wake, changeset);
718 if (last_end == (u64)-1)
720 start = last_end + 1;
721 if (start <= end && state && !need_resched())
727 spin_unlock(&tree->lock);
728 if (gfpflags_allow_blocking(mask))
733 spin_unlock(&tree->lock);
735 free_extent_state(prealloc);
741 static void wait_on_state(struct extent_io_tree *tree,
742 struct extent_state *state)
743 __releases(tree->lock)
744 __acquires(tree->lock)
747 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
748 spin_unlock(&tree->lock);
750 spin_lock(&tree->lock);
751 finish_wait(&state->wq, &wait);
755 * waits for one or more bits to clear on a range in the state tree.
756 * The range [start, end] is inclusive.
757 * The tree lock is taken by this function
759 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
762 struct extent_state *state;
763 struct rb_node *node;
765 btrfs_debug_check_extent_io_range(tree, start, end);
767 spin_lock(&tree->lock);
771 * this search will find all the extents that end after
774 node = tree_search(tree, start);
779 state = rb_entry(node, struct extent_state, rb_node);
781 if (state->start > end)
784 if (state->state & bits) {
785 start = state->start;
786 refcount_inc(&state->refs);
787 wait_on_state(tree, state);
788 free_extent_state(state);
791 start = state->end + 1;
796 if (!cond_resched_lock(&tree->lock)) {
797 node = rb_next(node);
802 spin_unlock(&tree->lock);
805 static void set_state_bits(struct extent_io_tree *tree,
806 struct extent_state *state,
807 unsigned *bits, struct extent_changeset *changeset)
809 unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
812 set_state_cb(tree, state, bits);
813 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
814 u64 range = state->end - state->start + 1;
815 tree->dirty_bytes += range;
817 ret = add_extent_changeset(state, bits_to_set, changeset, 1);
819 state->state |= bits_to_set;
822 static void cache_state_if_flags(struct extent_state *state,
823 struct extent_state **cached_ptr,
826 if (cached_ptr && !(*cached_ptr)) {
827 if (!flags || (state->state & flags)) {
829 refcount_inc(&state->refs);
834 static void cache_state(struct extent_state *state,
835 struct extent_state **cached_ptr)
837 return cache_state_if_flags(state, cached_ptr,
838 EXTENT_IOBITS | EXTENT_BOUNDARY);
842 * set some bits on a range in the tree. This may require allocations or
843 * sleeping, so the gfp mask is used to indicate what is allowed.
845 * If any of the exclusive bits are set, this will fail with -EEXIST if some
846 * part of the range already has the desired bits set. The start of the
847 * existing range is returned in failed_start in this case.
849 * [start, end] is inclusive This takes the tree lock.
852 static int __must_check
853 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
854 unsigned bits, unsigned exclusive_bits,
855 u64 *failed_start, struct extent_state **cached_state,
856 gfp_t mask, struct extent_changeset *changeset)
858 struct extent_state *state;
859 struct extent_state *prealloc = NULL;
860 struct rb_node *node;
862 struct rb_node *parent;
867 btrfs_debug_check_extent_io_range(tree, start, end);
869 bits |= EXTENT_FIRST_DELALLOC;
871 if (!prealloc && gfpflags_allow_blocking(mask)) {
873 * Don't care for allocation failure here because we might end
874 * up not needing the pre-allocated extent state at all, which
875 * is the case if we only have in the tree extent states that
876 * cover our input range and don't cover too any other range.
877 * If we end up needing a new extent state we allocate it later.
879 prealloc = alloc_extent_state(mask);
882 spin_lock(&tree->lock);
883 if (cached_state && *cached_state) {
884 state = *cached_state;
885 if (state->start <= start && state->end > start &&
886 extent_state_in_tree(state)) {
887 node = &state->rb_node;
892 * this search will find all the extents that end after
895 node = tree_search_for_insert(tree, start, &p, &parent);
897 prealloc = alloc_extent_state_atomic(prealloc);
899 err = insert_state(tree, prealloc, start, end,
900 &p, &parent, &bits, changeset);
902 extent_io_tree_panic(tree, err);
904 cache_state(prealloc, cached_state);
908 state = rb_entry(node, struct extent_state, rb_node);
910 last_start = state->start;
911 last_end = state->end;
914 * | ---- desired range ---- |
917 * Just lock what we found and keep going
919 if (state->start == start && state->end <= end) {
920 if (state->state & exclusive_bits) {
921 *failed_start = state->start;
926 set_state_bits(tree, state, &bits, changeset);
927 cache_state(state, cached_state);
928 merge_state(tree, state);
929 if (last_end == (u64)-1)
931 start = last_end + 1;
932 state = next_state(state);
933 if (start < end && state && state->start == start &&
940 * | ---- desired range ---- |
943 * | ------------- state -------------- |
945 * We need to split the extent we found, and may flip bits on
948 * If the extent we found extends past our
949 * range, we just split and search again. It'll get split
950 * again the next time though.
952 * If the extent we found is inside our range, we set the
955 if (state->start < start) {
956 if (state->state & exclusive_bits) {
957 *failed_start = start;
962 prealloc = alloc_extent_state_atomic(prealloc);
964 err = split_state(tree, state, prealloc, start);
966 extent_io_tree_panic(tree, err);
971 if (state->end <= end) {
972 set_state_bits(tree, state, &bits, changeset);
973 cache_state(state, cached_state);
974 merge_state(tree, state);
975 if (last_end == (u64)-1)
977 start = last_end + 1;
978 state = next_state(state);
979 if (start < end && state && state->start == start &&
986 * | ---- desired range ---- |
987 * | state | or | state |
989 * There's a hole, we need to insert something in it and
990 * ignore the extent we found.
992 if (state->start > start) {
994 if (end < last_start)
997 this_end = last_start - 1;
999 prealloc = alloc_extent_state_atomic(prealloc);
1003 * Avoid to free 'prealloc' if it can be merged with
1006 err = insert_state(tree, prealloc, start, this_end,
1007 NULL, NULL, &bits, changeset);
1009 extent_io_tree_panic(tree, err);
1011 cache_state(prealloc, cached_state);
1013 start = this_end + 1;
1017 * | ---- desired range ---- |
1019 * We need to split the extent, and set the bit
1022 if (state->start <= end && state->end > end) {
1023 if (state->state & exclusive_bits) {
1024 *failed_start = start;
1029 prealloc = alloc_extent_state_atomic(prealloc);
1031 err = split_state(tree, state, prealloc, end + 1);
1033 extent_io_tree_panic(tree, err);
1035 set_state_bits(tree, prealloc, &bits, changeset);
1036 cache_state(prealloc, cached_state);
1037 merge_state(tree, prealloc);
1045 spin_unlock(&tree->lock);
1046 if (gfpflags_allow_blocking(mask))
1051 spin_unlock(&tree->lock);
1053 free_extent_state(prealloc);
1059 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1060 unsigned bits, u64 * failed_start,
1061 struct extent_state **cached_state, gfp_t mask)
1063 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
1064 cached_state, mask, NULL);
1069 * convert_extent_bit - convert all bits in a given range from one bit to
1071 * @tree: the io tree to search
1072 * @start: the start offset in bytes
1073 * @end: the end offset in bytes (inclusive)
1074 * @bits: the bits to set in this range
1075 * @clear_bits: the bits to clear in this range
1076 * @cached_state: state that we're going to cache
1078 * This will go through and set bits for the given range. If any states exist
1079 * already in this range they are set with the given bit and cleared of the
1080 * clear_bits. This is only meant to be used by things that are mergeable, ie
1081 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1082 * boundary bits like LOCK.
1084 * All allocations are done with GFP_NOFS.
1086 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1087 unsigned bits, unsigned clear_bits,
1088 struct extent_state **cached_state)
1090 struct extent_state *state;
1091 struct extent_state *prealloc = NULL;
1092 struct rb_node *node;
1094 struct rb_node *parent;
1098 bool first_iteration = true;
1100 btrfs_debug_check_extent_io_range(tree, start, end);
1105 * Best effort, don't worry if extent state allocation fails
1106 * here for the first iteration. We might have a cached state
1107 * that matches exactly the target range, in which case no
1108 * extent state allocations are needed. We'll only know this
1109 * after locking the tree.
1111 prealloc = alloc_extent_state(GFP_NOFS);
1112 if (!prealloc && !first_iteration)
1116 spin_lock(&tree->lock);
1117 if (cached_state && *cached_state) {
1118 state = *cached_state;
1119 if (state->start <= start && state->end > start &&
1120 extent_state_in_tree(state)) {
1121 node = &state->rb_node;
1127 * this search will find all the extents that end after
1130 node = tree_search_for_insert(tree, start, &p, &parent);
1132 prealloc = alloc_extent_state_atomic(prealloc);
1137 err = insert_state(tree, prealloc, start, end,
1138 &p, &parent, &bits, NULL);
1140 extent_io_tree_panic(tree, err);
1141 cache_state(prealloc, cached_state);
1145 state = rb_entry(node, struct extent_state, rb_node);
1147 last_start = state->start;
1148 last_end = state->end;
1151 * | ---- desired range ---- |
1154 * Just lock what we found and keep going
1156 if (state->start == start && state->end <= end) {
1157 set_state_bits(tree, state, &bits, NULL);
1158 cache_state(state, cached_state);
1159 state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
1160 if (last_end == (u64)-1)
1162 start = last_end + 1;
1163 if (start < end && state && state->start == start &&
1170 * | ---- desired range ---- |
1173 * | ------------- state -------------- |
1175 * We need to split the extent we found, and may flip bits on
1178 * If the extent we found extends past our
1179 * range, we just split and search again. It'll get split
1180 * again the next time though.
1182 * If the extent we found is inside our range, we set the
1183 * desired bit on it.
1185 if (state->start < start) {
1186 prealloc = alloc_extent_state_atomic(prealloc);
1191 err = split_state(tree, state, prealloc, start);
1193 extent_io_tree_panic(tree, err);
1197 if (state->end <= end) {
1198 set_state_bits(tree, state, &bits, NULL);
1199 cache_state(state, cached_state);
1200 state = clear_state_bit(tree, state, &clear_bits, 0,
1202 if (last_end == (u64)-1)
1204 start = last_end + 1;
1205 if (start < end && state && state->start == start &&
1212 * | ---- desired range ---- |
1213 * | state | or | state |
1215 * There's a hole, we need to insert something in it and
1216 * ignore the extent we found.
1218 if (state->start > start) {
1220 if (end < last_start)
1223 this_end = last_start - 1;
1225 prealloc = alloc_extent_state_atomic(prealloc);
1232 * Avoid to free 'prealloc' if it can be merged with
1235 err = insert_state(tree, prealloc, start, this_end,
1236 NULL, NULL, &bits, NULL);
1238 extent_io_tree_panic(tree, err);
1239 cache_state(prealloc, cached_state);
1241 start = this_end + 1;
1245 * | ---- desired range ---- |
1247 * We need to split the extent, and set the bit
1250 if (state->start <= end && state->end > end) {
1251 prealloc = alloc_extent_state_atomic(prealloc);
1257 err = split_state(tree, state, prealloc, end + 1);
1259 extent_io_tree_panic(tree, err);
1261 set_state_bits(tree, prealloc, &bits, NULL);
1262 cache_state(prealloc, cached_state);
1263 clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
1271 spin_unlock(&tree->lock);
1273 first_iteration = false;
1277 spin_unlock(&tree->lock);
1279 free_extent_state(prealloc);
1284 /* wrappers around set/clear extent bit */
1285 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1286 unsigned bits, struct extent_changeset *changeset)
1289 * We don't support EXTENT_LOCKED yet, as current changeset will
1290 * record any bits changed, so for EXTENT_LOCKED case, it will
1291 * either fail with -EEXIST or changeset will record the whole
1294 BUG_ON(bits & EXTENT_LOCKED);
1296 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
1300 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1301 unsigned bits, int wake, int delete,
1302 struct extent_state **cached)
1304 return __clear_extent_bit(tree, start, end, bits, wake, delete,
1305 cached, GFP_NOFS, NULL);
1308 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1309 unsigned bits, struct extent_changeset *changeset)
1312 * Don't support EXTENT_LOCKED case, same reason as
1313 * set_record_extent_bits().
1315 BUG_ON(bits & EXTENT_LOCKED);
1317 return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
1322 * either insert or lock state struct between start and end use mask to tell
1323 * us if waiting is desired.
1325 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1326 struct extent_state **cached_state)
1332 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
1333 EXTENT_LOCKED, &failed_start,
1334 cached_state, GFP_NOFS, NULL);
1335 if (err == -EEXIST) {
1336 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1337 start = failed_start;
1340 WARN_ON(start > end);
1345 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1350 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1351 &failed_start, NULL, GFP_NOFS, NULL);
1352 if (err == -EEXIST) {
1353 if (failed_start > start)
1354 clear_extent_bit(tree, start, failed_start - 1,
1355 EXTENT_LOCKED, 1, 0, NULL);
1361 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1363 unsigned long index = start >> PAGE_SHIFT;
1364 unsigned long end_index = end >> PAGE_SHIFT;
1367 while (index <= end_index) {
1368 page = find_get_page(inode->i_mapping, index);
1369 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1370 clear_page_dirty_for_io(page);
1376 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1378 unsigned long index = start >> PAGE_SHIFT;
1379 unsigned long end_index = end >> PAGE_SHIFT;
1382 while (index <= end_index) {
1383 page = find_get_page(inode->i_mapping, index);
1384 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1385 __set_page_dirty_nobuffers(page);
1386 account_page_redirty(page);
1393 * helper function to set both pages and extents in the tree writeback
1395 static void set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1397 tree->ops->set_range_writeback(tree->private_data, start, end);
1400 /* find the first state struct with 'bits' set after 'start', and
1401 * return it. tree->lock must be held. NULL will returned if
1402 * nothing was found after 'start'
1404 static struct extent_state *
1405 find_first_extent_bit_state(struct extent_io_tree *tree,
1406 u64 start, unsigned bits)
1408 struct rb_node *node;
1409 struct extent_state *state;
1412 * this search will find all the extents that end after
1415 node = tree_search(tree, start);
1420 state = rb_entry(node, struct extent_state, rb_node);
1421 if (state->end >= start && (state->state & bits))
1424 node = rb_next(node);
1433 * find the first offset in the io tree with 'bits' set. zero is
1434 * returned if we find something, and *start_ret and *end_ret are
1435 * set to reflect the state struct that was found.
1437 * If nothing was found, 1 is returned. If found something, return 0.
1439 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1440 u64 *start_ret, u64 *end_ret, unsigned bits,
1441 struct extent_state **cached_state)
1443 struct extent_state *state;
1447 spin_lock(&tree->lock);
1448 if (cached_state && *cached_state) {
1449 state = *cached_state;
1450 if (state->end == start - 1 && extent_state_in_tree(state)) {
1451 n = rb_next(&state->rb_node);
1453 state = rb_entry(n, struct extent_state,
1455 if (state->state & bits)
1459 free_extent_state(*cached_state);
1460 *cached_state = NULL;
1463 free_extent_state(*cached_state);
1464 *cached_state = NULL;
1467 state = find_first_extent_bit_state(tree, start, bits);
1470 cache_state_if_flags(state, cached_state, 0);
1471 *start_ret = state->start;
1472 *end_ret = state->end;
1476 spin_unlock(&tree->lock);
1481 * find a contiguous range of bytes in the file marked as delalloc, not
1482 * more than 'max_bytes'. start and end are used to return the range,
1484 * 1 is returned if we find something, 0 if nothing was in the tree
1486 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1487 u64 *start, u64 *end, u64 max_bytes,
1488 struct extent_state **cached_state)
1490 struct rb_node *node;
1491 struct extent_state *state;
1492 u64 cur_start = *start;
1494 u64 total_bytes = 0;
1496 spin_lock(&tree->lock);
1499 * this search will find all the extents that end after
1502 node = tree_search(tree, cur_start);
1510 state = rb_entry(node, struct extent_state, rb_node);
1511 if (found && (state->start != cur_start ||
1512 (state->state & EXTENT_BOUNDARY))) {
1515 if (!(state->state & EXTENT_DELALLOC)) {
1521 *start = state->start;
1522 *cached_state = state;
1523 refcount_inc(&state->refs);
1527 cur_start = state->end + 1;
1528 node = rb_next(node);
1529 total_bytes += state->end - state->start + 1;
1530 if (total_bytes >= max_bytes)
1536 spin_unlock(&tree->lock);
1540 static int __process_pages_contig(struct address_space *mapping,
1541 struct page *locked_page,
1542 pgoff_t start_index, pgoff_t end_index,
1543 unsigned long page_ops, pgoff_t *index_ret);
1545 static noinline void __unlock_for_delalloc(struct inode *inode,
1546 struct page *locked_page,
1549 unsigned long index = start >> PAGE_SHIFT;
1550 unsigned long end_index = end >> PAGE_SHIFT;
1552 ASSERT(locked_page);
1553 if (index == locked_page->index && end_index == index)
1556 __process_pages_contig(inode->i_mapping, locked_page, index, end_index,
1560 static noinline int lock_delalloc_pages(struct inode *inode,
1561 struct page *locked_page,
1565 unsigned long index = delalloc_start >> PAGE_SHIFT;
1566 unsigned long index_ret = index;
1567 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1570 ASSERT(locked_page);
1571 if (index == locked_page->index && index == end_index)
1574 ret = __process_pages_contig(inode->i_mapping, locked_page, index,
1575 end_index, PAGE_LOCK, &index_ret);
1577 __unlock_for_delalloc(inode, locked_page, delalloc_start,
1578 (u64)index_ret << PAGE_SHIFT);
1583 * find a contiguous range of bytes in the file marked as delalloc, not
1584 * more than 'max_bytes'. start and end are used to return the range,
1586 * 1 is returned if we find something, 0 if nothing was in the tree
1588 STATIC u64 find_lock_delalloc_range(struct inode *inode,
1589 struct extent_io_tree *tree,
1590 struct page *locked_page, u64 *start,
1591 u64 *end, u64 max_bytes)
1596 struct extent_state *cached_state = NULL;
1601 /* step one, find a bunch of delalloc bytes starting at start */
1602 delalloc_start = *start;
1604 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1605 max_bytes, &cached_state);
1606 if (!found || delalloc_end <= *start) {
1607 *start = delalloc_start;
1608 *end = delalloc_end;
1609 free_extent_state(cached_state);
1614 * start comes from the offset of locked_page. We have to lock
1615 * pages in order, so we can't process delalloc bytes before
1618 if (delalloc_start < *start)
1619 delalloc_start = *start;
1622 * make sure to limit the number of pages we try to lock down
1624 if (delalloc_end + 1 - delalloc_start > max_bytes)
1625 delalloc_end = delalloc_start + max_bytes - 1;
1627 /* step two, lock all the pages after the page that has start */
1628 ret = lock_delalloc_pages(inode, locked_page,
1629 delalloc_start, delalloc_end);
1630 if (ret == -EAGAIN) {
1631 /* some of the pages are gone, lets avoid looping by
1632 * shortening the size of the delalloc range we're searching
1634 free_extent_state(cached_state);
1635 cached_state = NULL;
1637 max_bytes = PAGE_SIZE;
1645 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1647 /* step three, lock the state bits for the whole range */
1648 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1650 /* then test to make sure it is all still delalloc */
1651 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1652 EXTENT_DELALLOC, 1, cached_state);
1654 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1656 __unlock_for_delalloc(inode, locked_page,
1657 delalloc_start, delalloc_end);
1661 free_extent_state(cached_state);
1662 *start = delalloc_start;
1663 *end = delalloc_end;
1668 static int __process_pages_contig(struct address_space *mapping,
1669 struct page *locked_page,
1670 pgoff_t start_index, pgoff_t end_index,
1671 unsigned long page_ops, pgoff_t *index_ret)
1673 unsigned long nr_pages = end_index - start_index + 1;
1674 unsigned long pages_locked = 0;
1675 pgoff_t index = start_index;
1676 struct page *pages[16];
1681 if (page_ops & PAGE_LOCK) {
1682 ASSERT(page_ops == PAGE_LOCK);
1683 ASSERT(index_ret && *index_ret == start_index);
1686 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1687 mapping_set_error(mapping, -EIO);
1689 while (nr_pages > 0) {
1690 ret = find_get_pages_contig(mapping, index,
1691 min_t(unsigned long,
1692 nr_pages, ARRAY_SIZE(pages)), pages);
1695 * Only if we're going to lock these pages,
1696 * can we find nothing at @index.
1698 ASSERT(page_ops & PAGE_LOCK);
1703 for (i = 0; i < ret; i++) {
1704 if (page_ops & PAGE_SET_PRIVATE2)
1705 SetPagePrivate2(pages[i]);
1707 if (pages[i] == locked_page) {
1712 if (page_ops & PAGE_CLEAR_DIRTY)
1713 clear_page_dirty_for_io(pages[i]);
1714 if (page_ops & PAGE_SET_WRITEBACK)
1715 set_page_writeback(pages[i]);
1716 if (page_ops & PAGE_SET_ERROR)
1717 SetPageError(pages[i]);
1718 if (page_ops & PAGE_END_WRITEBACK)
1719 end_page_writeback(pages[i]);
1720 if (page_ops & PAGE_UNLOCK)
1721 unlock_page(pages[i]);
1722 if (page_ops & PAGE_LOCK) {
1723 lock_page(pages[i]);
1724 if (!PageDirty(pages[i]) ||
1725 pages[i]->mapping != mapping) {
1726 unlock_page(pages[i]);
1740 if (err && index_ret)
1741 *index_ret = start_index + pages_locked - 1;
1745 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1746 u64 delalloc_end, struct page *locked_page,
1747 unsigned clear_bits,
1748 unsigned long page_ops)
1750 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0,
1753 __process_pages_contig(inode->i_mapping, locked_page,
1754 start >> PAGE_SHIFT, end >> PAGE_SHIFT,
1759 * count the number of bytes in the tree that have a given bit(s)
1760 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1761 * cached. The total number found is returned.
1763 u64 count_range_bits(struct extent_io_tree *tree,
1764 u64 *start, u64 search_end, u64 max_bytes,
1765 unsigned bits, int contig)
1767 struct rb_node *node;
1768 struct extent_state *state;
1769 u64 cur_start = *start;
1770 u64 total_bytes = 0;
1774 if (WARN_ON(search_end <= cur_start))
1777 spin_lock(&tree->lock);
1778 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1779 total_bytes = tree->dirty_bytes;
1783 * this search will find all the extents that end after
1786 node = tree_search(tree, cur_start);
1791 state = rb_entry(node, struct extent_state, rb_node);
1792 if (state->start > search_end)
1794 if (contig && found && state->start > last + 1)
1796 if (state->end >= cur_start && (state->state & bits) == bits) {
1797 total_bytes += min(search_end, state->end) + 1 -
1798 max(cur_start, state->start);
1799 if (total_bytes >= max_bytes)
1802 *start = max(cur_start, state->start);
1806 } else if (contig && found) {
1809 node = rb_next(node);
1814 spin_unlock(&tree->lock);
1819 * set the private field for a given byte offset in the tree. If there isn't
1820 * an extent_state there already, this does nothing.
1822 static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start,
1823 struct io_failure_record *failrec)
1825 struct rb_node *node;
1826 struct extent_state *state;
1829 spin_lock(&tree->lock);
1831 * this search will find all the extents that end after
1834 node = tree_search(tree, start);
1839 state = rb_entry(node, struct extent_state, rb_node);
1840 if (state->start != start) {
1844 state->failrec = failrec;
1846 spin_unlock(&tree->lock);
1850 static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start,
1851 struct io_failure_record **failrec)
1853 struct rb_node *node;
1854 struct extent_state *state;
1857 spin_lock(&tree->lock);
1859 * this search will find all the extents that end after
1862 node = tree_search(tree, start);
1867 state = rb_entry(node, struct extent_state, rb_node);
1868 if (state->start != start) {
1872 *failrec = state->failrec;
1874 spin_unlock(&tree->lock);
1879 * searches a range in the state tree for a given mask.
1880 * If 'filled' == 1, this returns 1 only if every extent in the tree
1881 * has the bits set. Otherwise, 1 is returned if any bit in the
1882 * range is found set.
1884 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1885 unsigned bits, int filled, struct extent_state *cached)
1887 struct extent_state *state = NULL;
1888 struct rb_node *node;
1891 spin_lock(&tree->lock);
1892 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
1893 cached->end > start)
1894 node = &cached->rb_node;
1896 node = tree_search(tree, start);
1897 while (node && start <= end) {
1898 state = rb_entry(node, struct extent_state, rb_node);
1900 if (filled && state->start > start) {
1905 if (state->start > end)
1908 if (state->state & bits) {
1912 } else if (filled) {
1917 if (state->end == (u64)-1)
1920 start = state->end + 1;
1923 node = rb_next(node);
1930 spin_unlock(&tree->lock);
1935 * helper function to set a given page up to date if all the
1936 * extents in the tree for that page are up to date
1938 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1940 u64 start = page_offset(page);
1941 u64 end = start + PAGE_SIZE - 1;
1942 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1943 SetPageUptodate(page);
1946 int free_io_failure(struct extent_io_tree *failure_tree,
1947 struct extent_io_tree *io_tree,
1948 struct io_failure_record *rec)
1953 set_state_failrec(failure_tree, rec->start, NULL);
1954 ret = clear_extent_bits(failure_tree, rec->start,
1955 rec->start + rec->len - 1,
1956 EXTENT_LOCKED | EXTENT_DIRTY);
1960 ret = clear_extent_bits(io_tree, rec->start,
1961 rec->start + rec->len - 1,
1971 * this bypasses the standard btrfs submit functions deliberately, as
1972 * the standard behavior is to write all copies in a raid setup. here we only
1973 * want to write the one bad copy. so we do the mapping for ourselves and issue
1974 * submit_bio directly.
1975 * to avoid any synchronization issues, wait for the data after writing, which
1976 * actually prevents the read that triggered the error from finishing.
1977 * currently, there can be no more than two copies of every data bit. thus,
1978 * exactly one rewrite is required.
1980 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
1981 u64 length, u64 logical, struct page *page,
1982 unsigned int pg_offset, int mirror_num)
1985 struct btrfs_device *dev;
1988 struct btrfs_bio *bbio = NULL;
1991 ASSERT(!(fs_info->sb->s_flags & SB_RDONLY));
1992 BUG_ON(!mirror_num);
1994 bio = btrfs_io_bio_alloc(1);
1995 bio->bi_iter.bi_size = 0;
1996 map_length = length;
1999 * Avoid races with device replace and make sure our bbio has devices
2000 * associated to its stripes that don't go away while we are doing the
2001 * read repair operation.
2003 btrfs_bio_counter_inc_blocked(fs_info);
2004 if (btrfs_is_parity_mirror(fs_info, logical, length)) {
2006 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
2007 * to update all raid stripes, but here we just want to correct
2008 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
2009 * stripe's dev and sector.
2011 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical,
2012 &map_length, &bbio, 0);
2014 btrfs_bio_counter_dec(fs_info);
2018 ASSERT(bbio->mirror_num == 1);
2020 ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
2021 &map_length, &bbio, mirror_num);
2023 btrfs_bio_counter_dec(fs_info);
2027 BUG_ON(mirror_num != bbio->mirror_num);
2030 sector = bbio->stripes[bbio->mirror_num - 1].physical >> 9;
2031 bio->bi_iter.bi_sector = sector;
2032 dev = bbio->stripes[bbio->mirror_num - 1].dev;
2033 btrfs_put_bbio(bbio);
2034 if (!dev || !dev->bdev ||
2035 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
2036 btrfs_bio_counter_dec(fs_info);
2040 bio_set_dev(bio, dev->bdev);
2041 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
2042 bio_add_page(bio, page, length, pg_offset);
2044 if (btrfsic_submit_bio_wait(bio)) {
2045 /* try to remap that extent elsewhere? */
2046 btrfs_bio_counter_dec(fs_info);
2048 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2052 btrfs_info_rl_in_rcu(fs_info,
2053 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2055 rcu_str_deref(dev->name), sector);
2056 btrfs_bio_counter_dec(fs_info);
2061 int repair_eb_io_failure(struct btrfs_fs_info *fs_info,
2062 struct extent_buffer *eb, int mirror_num)
2064 u64 start = eb->start;
2065 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
2068 if (sb_rdonly(fs_info->sb))
2071 for (i = 0; i < num_pages; i++) {
2072 struct page *p = eb->pages[i];
2074 ret = repair_io_failure(fs_info, 0, start, PAGE_SIZE, start, p,
2075 start - page_offset(p), mirror_num);
2085 * each time an IO finishes, we do a fast check in the IO failure tree
2086 * to see if we need to process or clean up an io_failure_record
2088 int clean_io_failure(struct btrfs_fs_info *fs_info,
2089 struct extent_io_tree *failure_tree,
2090 struct extent_io_tree *io_tree, u64 start,
2091 struct page *page, u64 ino, unsigned int pg_offset)
2094 struct io_failure_record *failrec;
2095 struct extent_state *state;
2100 ret = count_range_bits(failure_tree, &private, (u64)-1, 1,
2105 ret = get_state_failrec(failure_tree, start, &failrec);
2109 BUG_ON(!failrec->this_mirror);
2111 if (failrec->in_validation) {
2112 /* there was no real error, just free the record */
2113 btrfs_debug(fs_info,
2114 "clean_io_failure: freeing dummy error at %llu",
2118 if (sb_rdonly(fs_info->sb))
2121 spin_lock(&io_tree->lock);
2122 state = find_first_extent_bit_state(io_tree,
2125 spin_unlock(&io_tree->lock);
2127 if (state && state->start <= failrec->start &&
2128 state->end >= failrec->start + failrec->len - 1) {
2129 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2131 if (num_copies > 1) {
2132 repair_io_failure(fs_info, ino, start, failrec->len,
2133 failrec->logical, page, pg_offset,
2134 failrec->failed_mirror);
2139 free_io_failure(failure_tree, io_tree, failrec);
2145 * Can be called when
2146 * - hold extent lock
2147 * - under ordered extent
2148 * - the inode is freeing
2150 void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end)
2152 struct extent_io_tree *failure_tree = &inode->io_failure_tree;
2153 struct io_failure_record *failrec;
2154 struct extent_state *state, *next;
2156 if (RB_EMPTY_ROOT(&failure_tree->state))
2159 spin_lock(&failure_tree->lock);
2160 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2162 if (state->start > end)
2165 ASSERT(state->end <= end);
2167 next = next_state(state);
2169 failrec = state->failrec;
2170 free_extent_state(state);
2175 spin_unlock(&failure_tree->lock);
2178 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2179 struct io_failure_record **failrec_ret)
2181 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2182 struct io_failure_record *failrec;
2183 struct extent_map *em;
2184 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2185 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2186 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2190 ret = get_state_failrec(failure_tree, start, &failrec);
2192 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2196 failrec->start = start;
2197 failrec->len = end - start + 1;
2198 failrec->this_mirror = 0;
2199 failrec->bio_flags = 0;
2200 failrec->in_validation = 0;
2202 read_lock(&em_tree->lock);
2203 em = lookup_extent_mapping(em_tree, start, failrec->len);
2205 read_unlock(&em_tree->lock);
2210 if (em->start > start || em->start + em->len <= start) {
2211 free_extent_map(em);
2214 read_unlock(&em_tree->lock);
2220 logical = start - em->start;
2221 logical = em->block_start + logical;
2222 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2223 logical = em->block_start;
2224 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2225 extent_set_compress_type(&failrec->bio_flags,
2229 btrfs_debug(fs_info,
2230 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2231 logical, start, failrec->len);
2233 failrec->logical = logical;
2234 free_extent_map(em);
2236 /* set the bits in the private failure tree */
2237 ret = set_extent_bits(failure_tree, start, end,
2238 EXTENT_LOCKED | EXTENT_DIRTY);
2240 ret = set_state_failrec(failure_tree, start, failrec);
2241 /* set the bits in the inode's tree */
2243 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2249 btrfs_debug(fs_info,
2250 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2251 failrec->logical, failrec->start, failrec->len,
2252 failrec->in_validation);
2254 * when data can be on disk more than twice, add to failrec here
2255 * (e.g. with a list for failed_mirror) to make
2256 * clean_io_failure() clean all those errors at once.
2260 *failrec_ret = failrec;
2265 bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages,
2266 struct io_failure_record *failrec, int failed_mirror)
2268 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2271 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
2272 if (num_copies == 1) {
2274 * we only have a single copy of the data, so don't bother with
2275 * all the retry and error correction code that follows. no
2276 * matter what the error is, it is very likely to persist.
2278 btrfs_debug(fs_info,
2279 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2280 num_copies, failrec->this_mirror, failed_mirror);
2285 * there are two premises:
2286 * a) deliver good data to the caller
2287 * b) correct the bad sectors on disk
2289 if (failed_bio_pages > 1) {
2291 * to fulfill b), we need to know the exact failing sectors, as
2292 * we don't want to rewrite any more than the failed ones. thus,
2293 * we need separate read requests for the failed bio
2295 * if the following BUG_ON triggers, our validation request got
2296 * merged. we need separate requests for our algorithm to work.
2298 BUG_ON(failrec->in_validation);
2299 failrec->in_validation = 1;
2300 failrec->this_mirror = failed_mirror;
2303 * we're ready to fulfill a) and b) alongside. get a good copy
2304 * of the failed sector and if we succeed, we have setup
2305 * everything for repair_io_failure to do the rest for us.
2307 if (failrec->in_validation) {
2308 BUG_ON(failrec->this_mirror != failed_mirror);
2309 failrec->in_validation = 0;
2310 failrec->this_mirror = 0;
2312 failrec->failed_mirror = failed_mirror;
2313 failrec->this_mirror++;
2314 if (failrec->this_mirror == failed_mirror)
2315 failrec->this_mirror++;
2318 if (failrec->this_mirror > num_copies) {
2319 btrfs_debug(fs_info,
2320 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2321 num_copies, failrec->this_mirror, failed_mirror);
2329 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
2330 struct io_failure_record *failrec,
2331 struct page *page, int pg_offset, int icsum,
2332 bio_end_io_t *endio_func, void *data)
2334 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2336 struct btrfs_io_bio *btrfs_failed_bio;
2337 struct btrfs_io_bio *btrfs_bio;
2339 bio = btrfs_io_bio_alloc(1);
2340 bio->bi_end_io = endio_func;
2341 bio->bi_iter.bi_sector = failrec->logical >> 9;
2342 bio_set_dev(bio, fs_info->fs_devices->latest_bdev);
2343 bio->bi_iter.bi_size = 0;
2344 bio->bi_private = data;
2346 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2347 if (btrfs_failed_bio->csum) {
2348 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2350 btrfs_bio = btrfs_io_bio(bio);
2351 btrfs_bio->csum = btrfs_bio->csum_inline;
2353 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
2357 bio_add_page(bio, page, failrec->len, pg_offset);
2363 * this is a generic handler for readpage errors (default
2364 * readpage_io_failed_hook). if other copies exist, read those and write back
2365 * good data to the failed position. does not investigate in remapping the
2366 * failed extent elsewhere, hoping the device will be smart enough to do this as
2370 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2371 struct page *page, u64 start, u64 end,
2374 struct io_failure_record *failrec;
2375 struct inode *inode = page->mapping->host;
2376 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2377 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2380 blk_status_t status;
2382 unsigned failed_bio_pages = bio_pages_all(failed_bio);
2384 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2386 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2390 if (!btrfs_check_repairable(inode, failed_bio_pages, failrec,
2392 free_io_failure(failure_tree, tree, failrec);
2396 if (failed_bio_pages > 1)
2397 read_mode |= REQ_FAILFAST_DEV;
2399 phy_offset >>= inode->i_sb->s_blocksize_bits;
2400 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
2401 start - page_offset(page),
2402 (int)phy_offset, failed_bio->bi_end_io,
2404 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
2406 btrfs_debug(btrfs_sb(inode->i_sb),
2407 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2408 read_mode, failrec->this_mirror, failrec->in_validation);
2410 status = tree->ops->submit_bio_hook(tree->private_data, bio, failrec->this_mirror,
2411 failrec->bio_flags, 0);
2413 free_io_failure(failure_tree, tree, failrec);
2415 ret = blk_status_to_errno(status);
2421 /* lots and lots of room for performance fixes in the end_bio funcs */
2423 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2425 int uptodate = (err == 0);
2426 struct extent_io_tree *tree;
2429 tree = &BTRFS_I(page->mapping->host)->io_tree;
2431 if (tree->ops && tree->ops->writepage_end_io_hook)
2432 tree->ops->writepage_end_io_hook(page, start, end, NULL,
2436 ClearPageUptodate(page);
2438 ret = err < 0 ? err : -EIO;
2439 mapping_set_error(page->mapping, ret);
2444 * after a writepage IO is done, we need to:
2445 * clear the uptodate bits on error
2446 * clear the writeback bits in the extent tree for this IO
2447 * end_page_writeback if the page has no more pending IO
2449 * Scheduling is not allowed, so the extent state tree is expected
2450 * to have one and only one object corresponding to this IO.
2452 static void end_bio_extent_writepage(struct bio *bio)
2454 int error = blk_status_to_errno(bio->bi_status);
2455 struct bio_vec *bvec;
2460 ASSERT(!bio_flagged(bio, BIO_CLONED));
2461 bio_for_each_segment_all(bvec, bio, i) {
2462 struct page *page = bvec->bv_page;
2463 struct inode *inode = page->mapping->host;
2464 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2466 /* We always issue full-page reads, but if some block
2467 * in a page fails to read, blk_update_request() will
2468 * advance bv_offset and adjust bv_len to compensate.
2469 * Print a warning for nonzero offsets, and an error
2470 * if they don't add up to a full page. */
2471 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2472 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2474 "partial page write in btrfs with offset %u and length %u",
2475 bvec->bv_offset, bvec->bv_len);
2478 "incomplete page write in btrfs with offset %u and length %u",
2479 bvec->bv_offset, bvec->bv_len);
2482 start = page_offset(page);
2483 end = start + bvec->bv_offset + bvec->bv_len - 1;
2485 end_extent_writepage(page, error, start, end);
2486 end_page_writeback(page);
2493 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2496 struct extent_state *cached = NULL;
2497 u64 end = start + len - 1;
2499 if (uptodate && tree->track_uptodate)
2500 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2501 unlock_extent_cached_atomic(tree, start, end, &cached);
2505 * after a readpage IO is done, we need to:
2506 * clear the uptodate bits on error
2507 * set the uptodate bits if things worked
2508 * set the page up to date if all extents in the tree are uptodate
2509 * clear the lock bit in the extent tree
2510 * unlock the page if there are no other extents locked for it
2512 * Scheduling is not allowed, so the extent state tree is expected
2513 * to have one and only one object corresponding to this IO.
2515 static void end_bio_extent_readpage(struct bio *bio)
2517 struct bio_vec *bvec;
2518 int uptodate = !bio->bi_status;
2519 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2520 struct extent_io_tree *tree, *failure_tree;
2525 u64 extent_start = 0;
2531 ASSERT(!bio_flagged(bio, BIO_CLONED));
2532 bio_for_each_segment_all(bvec, bio, i) {
2533 struct page *page = bvec->bv_page;
2534 struct inode *inode = page->mapping->host;
2535 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2537 btrfs_debug(fs_info,
2538 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2539 (u64)bio->bi_iter.bi_sector, bio->bi_status,
2540 io_bio->mirror_num);
2541 tree = &BTRFS_I(inode)->io_tree;
2542 failure_tree = &BTRFS_I(inode)->io_failure_tree;
2544 /* We always issue full-page reads, but if some block
2545 * in a page fails to read, blk_update_request() will
2546 * advance bv_offset and adjust bv_len to compensate.
2547 * Print a warning for nonzero offsets, and an error
2548 * if they don't add up to a full page. */
2549 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2550 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2552 "partial page read in btrfs with offset %u and length %u",
2553 bvec->bv_offset, bvec->bv_len);
2556 "incomplete page read in btrfs with offset %u and length %u",
2557 bvec->bv_offset, bvec->bv_len);
2560 start = page_offset(page);
2561 end = start + bvec->bv_offset + bvec->bv_len - 1;
2564 mirror = io_bio->mirror_num;
2565 if (likely(uptodate && tree->ops)) {
2566 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2572 clean_io_failure(BTRFS_I(inode)->root->fs_info,
2573 failure_tree, tree, start,
2575 btrfs_ino(BTRFS_I(inode)), 0);
2578 if (likely(uptodate))
2582 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2583 if (ret == -EAGAIN) {
2585 * Data inode's readpage_io_failed_hook() always
2588 * The generic bio_readpage_error handles errors
2589 * the following way: If possible, new read
2590 * requests are created and submitted and will
2591 * end up in end_bio_extent_readpage as well (if
2592 * we're lucky, not in the !uptodate case). In
2593 * that case it returns 0 and we just go on with
2594 * the next page in our bio. If it can't handle
2595 * the error it will return -EIO and we remain
2596 * responsible for that page.
2598 ret = bio_readpage_error(bio, offset, page,
2599 start, end, mirror);
2601 uptodate = !bio->bi_status;
2608 * metadata's readpage_io_failed_hook() always returns
2609 * -EIO and fixes nothing. -EIO is also returned if
2610 * data inode error could not be fixed.
2612 ASSERT(ret == -EIO);
2615 if (likely(uptodate)) {
2616 loff_t i_size = i_size_read(inode);
2617 pgoff_t end_index = i_size >> PAGE_SHIFT;
2620 /* Zero out the end if this page straddles i_size */
2621 off = i_size & (PAGE_SIZE-1);
2622 if (page->index == end_index && off)
2623 zero_user_segment(page, off, PAGE_SIZE);
2624 SetPageUptodate(page);
2626 ClearPageUptodate(page);
2632 if (unlikely(!uptodate)) {
2634 endio_readpage_release_extent(tree,
2640 endio_readpage_release_extent(tree, start,
2641 end - start + 1, 0);
2642 } else if (!extent_len) {
2643 extent_start = start;
2644 extent_len = end + 1 - start;
2645 } else if (extent_start + extent_len == start) {
2646 extent_len += end + 1 - start;
2648 endio_readpage_release_extent(tree, extent_start,
2649 extent_len, uptodate);
2650 extent_start = start;
2651 extent_len = end + 1 - start;
2656 endio_readpage_release_extent(tree, extent_start, extent_len,
2659 io_bio->end_io(io_bio, blk_status_to_errno(bio->bi_status));
2664 * Initialize the members up to but not including 'bio'. Use after allocating a
2665 * new bio by bio_alloc_bioset as it does not initialize the bytes outside of
2666 * 'bio' because use of __GFP_ZERO is not supported.
2668 static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio)
2670 memset(btrfs_bio, 0, offsetof(struct btrfs_io_bio, bio));
2674 * The following helpers allocate a bio. As it's backed by a bioset, it'll
2675 * never fail. We're returning a bio right now but you can call btrfs_io_bio
2676 * for the appropriate container_of magic
2678 struct bio *btrfs_bio_alloc(struct block_device *bdev, u64 first_byte)
2682 bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, btrfs_bioset);
2683 bio_set_dev(bio, bdev);
2684 bio->bi_iter.bi_sector = first_byte >> 9;
2685 btrfs_io_bio_init(btrfs_io_bio(bio));
2689 struct bio *btrfs_bio_clone(struct bio *bio)
2691 struct btrfs_io_bio *btrfs_bio;
2694 /* Bio allocation backed by a bioset does not fail */
2695 new = bio_clone_fast(bio, GFP_NOFS, btrfs_bioset);
2696 btrfs_bio = btrfs_io_bio(new);
2697 btrfs_io_bio_init(btrfs_bio);
2698 btrfs_bio->iter = bio->bi_iter;
2702 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs)
2706 /* Bio allocation backed by a bioset does not fail */
2707 bio = bio_alloc_bioset(GFP_NOFS, nr_iovecs, btrfs_bioset);
2708 btrfs_io_bio_init(btrfs_io_bio(bio));
2712 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
2715 struct btrfs_io_bio *btrfs_bio;
2717 /* this will never fail when it's backed by a bioset */
2718 bio = bio_clone_fast(orig, GFP_NOFS, btrfs_bioset);
2721 btrfs_bio = btrfs_io_bio(bio);
2722 btrfs_io_bio_init(btrfs_bio);
2724 bio_trim(bio, offset >> 9, size >> 9);
2725 btrfs_bio->iter = bio->bi_iter;
2729 static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
2730 unsigned long bio_flags)
2732 blk_status_t ret = 0;
2733 struct bio_vec *bvec = bio_last_bvec_all(bio);
2734 struct page *page = bvec->bv_page;
2735 struct extent_io_tree *tree = bio->bi_private;
2738 start = page_offset(page) + bvec->bv_offset;
2740 bio->bi_private = NULL;
2743 ret = tree->ops->submit_bio_hook(tree->private_data, bio,
2744 mirror_num, bio_flags, start);
2746 btrfsic_submit_bio(bio);
2748 return blk_status_to_errno(ret);
2752 * @opf: bio REQ_OP_* and REQ_* flags as one value
2753 * @tree: tree so we can call our merge_bio hook
2754 * @wbc: optional writeback control for io accounting
2755 * @page: page to add to the bio
2756 * @pg_offset: offset of the new bio or to check whether we are adding
2757 * a contiguous page to the previous one
2758 * @size: portion of page that we want to write
2759 * @offset: starting offset in the page
2760 * @bdev: attach newly created bios to this bdev
2761 * @bio_ret: must be valid pointer, newly allocated bio will be stored there
2762 * @end_io_func: end_io callback for new bio
2763 * @mirror_num: desired mirror to read/write
2764 * @prev_bio_flags: flags of previous bio to see if we can merge the current one
2765 * @bio_flags: flags of the current bio to see if we can merge them
2767 static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
2768 struct writeback_control *wbc,
2769 struct page *page, u64 offset,
2770 size_t size, unsigned long pg_offset,
2771 struct block_device *bdev,
2772 struct bio **bio_ret,
2773 bio_end_io_t end_io_func,
2775 unsigned long prev_bio_flags,
2776 unsigned long bio_flags,
2777 bool force_bio_submit)
2781 size_t page_size = min_t(size_t, size, PAGE_SIZE);
2782 sector_t sector = offset >> 9;
2788 bool can_merge = true;
2791 if (prev_bio_flags & EXTENT_BIO_COMPRESSED)
2792 contig = bio->bi_iter.bi_sector == sector;
2794 contig = bio_end_sector(bio) == sector;
2796 if (tree->ops && tree->ops->merge_bio_hook(page, offset,
2797 page_size, bio, bio_flags))
2800 if (prev_bio_flags != bio_flags || !contig || !can_merge ||
2802 bio_add_page(bio, page, page_size, pg_offset) < page_size) {
2803 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
2811 wbc_account_io(wbc, page, page_size);
2816 bio = btrfs_bio_alloc(bdev, offset);
2817 bio_add_page(bio, page, page_size, pg_offset);
2818 bio->bi_end_io = end_io_func;
2819 bio->bi_private = tree;
2820 bio->bi_write_hint = page->mapping->host->i_write_hint;
2823 wbc_init_bio(wbc, bio);
2824 wbc_account_io(wbc, page, page_size);
2832 static void attach_extent_buffer_page(struct extent_buffer *eb,
2835 if (!PagePrivate(page)) {
2836 SetPagePrivate(page);
2838 set_page_private(page, (unsigned long)eb);
2840 WARN_ON(page->private != (unsigned long)eb);
2844 void set_page_extent_mapped(struct page *page)
2846 if (!PagePrivate(page)) {
2847 SetPagePrivate(page);
2849 set_page_private(page, EXTENT_PAGE_PRIVATE);
2853 static struct extent_map *
2854 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
2855 u64 start, u64 len, get_extent_t *get_extent,
2856 struct extent_map **em_cached)
2858 struct extent_map *em;
2860 if (em_cached && *em_cached) {
2862 if (extent_map_in_tree(em) && start >= em->start &&
2863 start < extent_map_end(em)) {
2864 refcount_inc(&em->refs);
2868 free_extent_map(em);
2872 em = get_extent(BTRFS_I(inode), page, pg_offset, start, len, 0);
2873 if (em_cached && !IS_ERR_OR_NULL(em)) {
2875 refcount_inc(&em->refs);
2881 * basic readpage implementation. Locked extent state structs are inserted
2882 * into the tree that are removed when the IO is done (by the end_io
2884 * XXX JDM: This needs looking at to ensure proper page locking
2885 * return 0 on success, otherwise return error
2887 static int __do_readpage(struct extent_io_tree *tree,
2889 get_extent_t *get_extent,
2890 struct extent_map **em_cached,
2891 struct bio **bio, int mirror_num,
2892 unsigned long *bio_flags, unsigned int read_flags,
2895 struct inode *inode = page->mapping->host;
2896 u64 start = page_offset(page);
2897 const u64 end = start + PAGE_SIZE - 1;
2900 u64 last_byte = i_size_read(inode);
2903 struct extent_map *em;
2904 struct block_device *bdev;
2907 size_t pg_offset = 0;
2909 size_t disk_io_size;
2910 size_t blocksize = inode->i_sb->s_blocksize;
2911 unsigned long this_bio_flag = 0;
2913 set_page_extent_mapped(page);
2915 if (!PageUptodate(page)) {
2916 if (cleancache_get_page(page) == 0) {
2917 BUG_ON(blocksize != PAGE_SIZE);
2918 unlock_extent(tree, start, end);
2923 if (page->index == last_byte >> PAGE_SHIFT) {
2925 size_t zero_offset = last_byte & (PAGE_SIZE - 1);
2928 iosize = PAGE_SIZE - zero_offset;
2929 userpage = kmap_atomic(page);
2930 memset(userpage + zero_offset, 0, iosize);
2931 flush_dcache_page(page);
2932 kunmap_atomic(userpage);
2935 while (cur <= end) {
2936 bool force_bio_submit = false;
2939 if (cur >= last_byte) {
2941 struct extent_state *cached = NULL;
2943 iosize = PAGE_SIZE - pg_offset;
2944 userpage = kmap_atomic(page);
2945 memset(userpage + pg_offset, 0, iosize);
2946 flush_dcache_page(page);
2947 kunmap_atomic(userpage);
2948 set_extent_uptodate(tree, cur, cur + iosize - 1,
2950 unlock_extent_cached(tree, cur,
2951 cur + iosize - 1, &cached);
2954 em = __get_extent_map(inode, page, pg_offset, cur,
2955 end - cur + 1, get_extent, em_cached);
2956 if (IS_ERR_OR_NULL(em)) {
2958 unlock_extent(tree, cur, end);
2961 extent_offset = cur - em->start;
2962 BUG_ON(extent_map_end(em) <= cur);
2965 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2966 this_bio_flag |= EXTENT_BIO_COMPRESSED;
2967 extent_set_compress_type(&this_bio_flag,
2971 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2972 cur_end = min(extent_map_end(em) - 1, end);
2973 iosize = ALIGN(iosize, blocksize);
2974 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2975 disk_io_size = em->block_len;
2976 offset = em->block_start;
2978 offset = em->block_start + extent_offset;
2979 disk_io_size = iosize;
2982 block_start = em->block_start;
2983 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2984 block_start = EXTENT_MAP_HOLE;
2987 * If we have a file range that points to a compressed extent
2988 * and it's followed by a consecutive file range that points to
2989 * to the same compressed extent (possibly with a different
2990 * offset and/or length, so it either points to the whole extent
2991 * or only part of it), we must make sure we do not submit a
2992 * single bio to populate the pages for the 2 ranges because
2993 * this makes the compressed extent read zero out the pages
2994 * belonging to the 2nd range. Imagine the following scenario:
2997 * [0 - 8K] [8K - 24K]
3000 * points to extent X, points to extent X,
3001 * offset 4K, length of 8K offset 0, length 16K
3003 * [extent X, compressed length = 4K uncompressed length = 16K]
3005 * If the bio to read the compressed extent covers both ranges,
3006 * it will decompress extent X into the pages belonging to the
3007 * first range and then it will stop, zeroing out the remaining
3008 * pages that belong to the other range that points to extent X.
3009 * So here we make sure we submit 2 bios, one for the first
3010 * range and another one for the third range. Both will target
3011 * the same physical extent from disk, but we can't currently
3012 * make the compressed bio endio callback populate the pages
3013 * for both ranges because each compressed bio is tightly
3014 * coupled with a single extent map, and each range can have
3015 * an extent map with a different offset value relative to the
3016 * uncompressed data of our extent and different lengths. This
3017 * is a corner case so we prioritize correctness over
3018 * non-optimal behavior (submitting 2 bios for the same extent).
3020 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3021 prev_em_start && *prev_em_start != (u64)-1 &&
3022 *prev_em_start != em->orig_start)
3023 force_bio_submit = true;
3026 *prev_em_start = em->orig_start;
3028 free_extent_map(em);
3031 /* we've found a hole, just zero and go on */
3032 if (block_start == EXTENT_MAP_HOLE) {
3034 struct extent_state *cached = NULL;
3036 userpage = kmap_atomic(page);
3037 memset(userpage + pg_offset, 0, iosize);
3038 flush_dcache_page(page);
3039 kunmap_atomic(userpage);
3041 set_extent_uptodate(tree, cur, cur + iosize - 1,
3043 unlock_extent_cached(tree, cur,
3044 cur + iosize - 1, &cached);
3046 pg_offset += iosize;
3049 /* the get_extent function already copied into the page */
3050 if (test_range_bit(tree, cur, cur_end,
3051 EXTENT_UPTODATE, 1, NULL)) {
3052 check_page_uptodate(tree, page);
3053 unlock_extent(tree, cur, cur + iosize - 1);
3055 pg_offset += iosize;
3058 /* we have an inline extent but it didn't get marked up
3059 * to date. Error out
3061 if (block_start == EXTENT_MAP_INLINE) {
3063 unlock_extent(tree, cur, cur + iosize - 1);
3065 pg_offset += iosize;
3069 ret = submit_extent_page(REQ_OP_READ | read_flags, tree, NULL,
3070 page, offset, disk_io_size,
3071 pg_offset, bdev, bio,
3072 end_bio_extent_readpage, mirror_num,
3078 *bio_flags = this_bio_flag;
3081 unlock_extent(tree, cur, cur + iosize - 1);
3085 pg_offset += iosize;
3089 if (!PageError(page))
3090 SetPageUptodate(page);
3096 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
3097 struct page *pages[], int nr_pages,
3099 struct extent_map **em_cached,
3101 unsigned long *bio_flags,
3104 struct inode *inode;
3105 struct btrfs_ordered_extent *ordered;
3108 inode = pages[0]->mapping->host;
3110 lock_extent(tree, start, end);
3111 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
3115 unlock_extent(tree, start, end);
3116 btrfs_start_ordered_extent(inode, ordered, 1);
3117 btrfs_put_ordered_extent(ordered);
3120 for (index = 0; index < nr_pages; index++) {
3121 __do_readpage(tree, pages[index], btrfs_get_extent, em_cached,
3122 bio, 0, bio_flags, 0, prev_em_start);
3123 put_page(pages[index]);
3127 static void __extent_readpages(struct extent_io_tree *tree,
3128 struct page *pages[],
3130 struct extent_map **em_cached,
3131 struct bio **bio, unsigned long *bio_flags,
3138 int first_index = 0;
3140 for (index = 0; index < nr_pages; index++) {
3141 page_start = page_offset(pages[index]);
3144 end = start + PAGE_SIZE - 1;
3145 first_index = index;
3146 } else if (end + 1 == page_start) {
3149 __do_contiguous_readpages(tree, &pages[first_index],
3150 index - first_index, start,
3155 end = start + PAGE_SIZE - 1;
3156 first_index = index;
3161 __do_contiguous_readpages(tree, &pages[first_index],
3162 index - first_index, start,
3163 end, em_cached, bio,
3164 bio_flags, prev_em_start);
3167 static int __extent_read_full_page(struct extent_io_tree *tree,
3169 get_extent_t *get_extent,
3170 struct bio **bio, int mirror_num,
3171 unsigned long *bio_flags,
3172 unsigned int read_flags)
3174 struct inode *inode = page->mapping->host;
3175 struct btrfs_ordered_extent *ordered;
3176 u64 start = page_offset(page);
3177 u64 end = start + PAGE_SIZE - 1;
3181 lock_extent(tree, start, end);
3182 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
3186 unlock_extent(tree, start, end);
3187 btrfs_start_ordered_extent(inode, ordered, 1);
3188 btrfs_put_ordered_extent(ordered);
3191 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3192 bio_flags, read_flags, NULL);
3196 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3197 get_extent_t *get_extent, int mirror_num)
3199 struct bio *bio = NULL;
3200 unsigned long bio_flags = 0;
3203 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3206 ret = submit_one_bio(bio, mirror_num, bio_flags);
3210 static void update_nr_written(struct writeback_control *wbc,
3211 unsigned long nr_written)
3213 wbc->nr_to_write -= nr_written;
3217 * helper for __extent_writepage, doing all of the delayed allocation setup.
3219 * This returns 1 if our fill_delalloc function did all the work required
3220 * to write the page (copy into inline extent). In this case the IO has
3221 * been started and the page is already unlocked.
3223 * This returns 0 if all went well (page still locked)
3224 * This returns < 0 if there were errors (page still locked)
3226 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3227 struct page *page, struct writeback_control *wbc,
3228 struct extent_page_data *epd,
3230 unsigned long *nr_written)
3232 struct extent_io_tree *tree = epd->tree;
3233 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3235 u64 delalloc_to_write = 0;
3236 u64 delalloc_end = 0;
3238 int page_started = 0;
3240 if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
3243 while (delalloc_end < page_end) {
3244 nr_delalloc = find_lock_delalloc_range(inode, tree,
3248 BTRFS_MAX_EXTENT_SIZE);
3249 if (nr_delalloc == 0) {
3250 delalloc_start = delalloc_end + 1;
3253 ret = tree->ops->fill_delalloc(inode, page,
3258 /* File system has been set read-only */
3261 /* fill_delalloc should be return < 0 for error
3262 * but just in case, we use > 0 here meaning the
3263 * IO is started, so we don't want to return > 0
3264 * unless things are going well.
3266 ret = ret < 0 ? ret : -EIO;
3270 * delalloc_end is already one less than the total length, so
3271 * we don't subtract one from PAGE_SIZE
3273 delalloc_to_write += (delalloc_end - delalloc_start +
3274 PAGE_SIZE) >> PAGE_SHIFT;
3275 delalloc_start = delalloc_end + 1;
3277 if (wbc->nr_to_write < delalloc_to_write) {
3280 if (delalloc_to_write < thresh * 2)
3281 thresh = delalloc_to_write;
3282 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3286 /* did the fill delalloc function already unlock and start
3291 * we've unlocked the page, so we can't update
3292 * the mapping's writeback index, just update
3295 wbc->nr_to_write -= *nr_written;
3306 * helper for __extent_writepage. This calls the writepage start hooks,
3307 * and does the loop to map the page into extents and bios.
3309 * We return 1 if the IO is started and the page is unlocked,
3310 * 0 if all went well (page still locked)
3311 * < 0 if there were errors (page still locked)
3313 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3315 struct writeback_control *wbc,
3316 struct extent_page_data *epd,
3318 unsigned long nr_written,
3319 unsigned int write_flags, int *nr_ret)
3321 struct extent_io_tree *tree = epd->tree;
3322 u64 start = page_offset(page);
3323 u64 page_end = start + PAGE_SIZE - 1;
3329 struct extent_map *em;
3330 struct block_device *bdev;
3331 size_t pg_offset = 0;
3337 if (tree->ops && tree->ops->writepage_start_hook) {
3338 ret = tree->ops->writepage_start_hook(page, start,
3341 /* Fixup worker will requeue */
3343 wbc->pages_skipped++;
3345 redirty_page_for_writepage(wbc, page);
3347 update_nr_written(wbc, nr_written);
3354 * we don't want to touch the inode after unlocking the page,
3355 * so we update the mapping writeback index now
3357 update_nr_written(wbc, nr_written + 1);
3360 if (i_size <= start) {
3361 if (tree->ops && tree->ops->writepage_end_io_hook)
3362 tree->ops->writepage_end_io_hook(page, start,
3367 blocksize = inode->i_sb->s_blocksize;
3369 while (cur <= end) {
3373 if (cur >= i_size) {
3374 if (tree->ops && tree->ops->writepage_end_io_hook)
3375 tree->ops->writepage_end_io_hook(page, cur,
3379 em = btrfs_get_extent(BTRFS_I(inode), page, pg_offset, cur,
3381 if (IS_ERR_OR_NULL(em)) {
3383 ret = PTR_ERR_OR_ZERO(em);
3387 extent_offset = cur - em->start;
3388 em_end = extent_map_end(em);
3389 BUG_ON(em_end <= cur);
3391 iosize = min(em_end - cur, end - cur + 1);
3392 iosize = ALIGN(iosize, blocksize);
3393 offset = em->block_start + extent_offset;
3395 block_start = em->block_start;
3396 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3397 free_extent_map(em);
3401 * compressed and inline extents are written through other
3404 if (compressed || block_start == EXTENT_MAP_HOLE ||
3405 block_start == EXTENT_MAP_INLINE) {
3407 * end_io notification does not happen here for
3408 * compressed extents
3410 if (!compressed && tree->ops &&
3411 tree->ops->writepage_end_io_hook)
3412 tree->ops->writepage_end_io_hook(page, cur,
3415 else if (compressed) {
3416 /* we don't want to end_page_writeback on
3417 * a compressed extent. this happens
3424 pg_offset += iosize;
3428 set_range_writeback(tree, cur, cur + iosize - 1);
3429 if (!PageWriteback(page)) {
3430 btrfs_err(BTRFS_I(inode)->root->fs_info,
3431 "page %lu not writeback, cur %llu end %llu",
3432 page->index, cur, end);
3435 ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
3436 page, offset, iosize, pg_offset,
3438 end_bio_extent_writepage,
3442 if (PageWriteback(page))
3443 end_page_writeback(page);
3447 pg_offset += iosize;
3456 * the writepage semantics are similar to regular writepage. extent
3457 * records are inserted to lock ranges in the tree, and as dirty areas
3458 * are found, they are marked writeback. Then the lock bits are removed
3459 * and the end_io handler clears the writeback ranges
3461 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3462 struct extent_page_data *epd)
3464 struct inode *inode = page->mapping->host;
3465 u64 start = page_offset(page);
3466 u64 page_end = start + PAGE_SIZE - 1;
3469 size_t pg_offset = 0;
3470 loff_t i_size = i_size_read(inode);
3471 unsigned long end_index = i_size >> PAGE_SHIFT;
3472 unsigned int write_flags = 0;
3473 unsigned long nr_written = 0;
3475 write_flags = wbc_to_write_flags(wbc);
3477 trace___extent_writepage(page, inode, wbc);
3479 WARN_ON(!PageLocked(page));
3481 ClearPageError(page);
3483 pg_offset = i_size & (PAGE_SIZE - 1);
3484 if (page->index > end_index ||
3485 (page->index == end_index && !pg_offset)) {
3486 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3491 if (page->index == end_index) {
3494 userpage = kmap_atomic(page);
3495 memset(userpage + pg_offset, 0,
3496 PAGE_SIZE - pg_offset);
3497 kunmap_atomic(userpage);
3498 flush_dcache_page(page);
3503 set_page_extent_mapped(page);
3505 ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
3511 ret = __extent_writepage_io(inode, page, wbc, epd,
3512 i_size, nr_written, write_flags, &nr);
3518 /* make sure the mapping tag for page dirty gets cleared */
3519 set_page_writeback(page);
3520 end_page_writeback(page);
3522 if (PageError(page)) {
3523 ret = ret < 0 ? ret : -EIO;
3524 end_extent_writepage(page, ret, start, page_end);
3533 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3535 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3536 TASK_UNINTERRUPTIBLE);
3539 static noinline_for_stack int
3540 lock_extent_buffer_for_io(struct extent_buffer *eb,
3541 struct btrfs_fs_info *fs_info,
3542 struct extent_page_data *epd)
3544 unsigned long i, num_pages;
3548 if (!btrfs_try_tree_write_lock(eb)) {
3550 flush_write_bio(epd);
3551 btrfs_tree_lock(eb);
3554 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3555 btrfs_tree_unlock(eb);
3559 flush_write_bio(epd);
3563 wait_on_extent_buffer_writeback(eb);
3564 btrfs_tree_lock(eb);
3565 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3567 btrfs_tree_unlock(eb);
3572 * We need to do this to prevent races in people who check if the eb is
3573 * under IO since we can end up having no IO bits set for a short period
3576 spin_lock(&eb->refs_lock);
3577 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3578 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3579 spin_unlock(&eb->refs_lock);
3580 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3581 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
3583 fs_info->dirty_metadata_batch);
3586 spin_unlock(&eb->refs_lock);
3589 btrfs_tree_unlock(eb);
3594 num_pages = num_extent_pages(eb->start, eb->len);
3595 for (i = 0; i < num_pages; i++) {
3596 struct page *p = eb->pages[i];
3598 if (!trylock_page(p)) {
3600 flush_write_bio(epd);
3610 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3612 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3613 smp_mb__after_atomic();
3614 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3617 static void set_btree_ioerr(struct page *page)
3619 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3622 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3626 * If writeback for a btree extent that doesn't belong to a log tree
3627 * failed, increment the counter transaction->eb_write_errors.
3628 * We do this because while the transaction is running and before it's
3629 * committing (when we call filemap_fdata[write|wait]_range against
3630 * the btree inode), we might have
3631 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3632 * returns an error or an error happens during writeback, when we're
3633 * committing the transaction we wouldn't know about it, since the pages
3634 * can be no longer dirty nor marked anymore for writeback (if a
3635 * subsequent modification to the extent buffer didn't happen before the
3636 * transaction commit), which makes filemap_fdata[write|wait]_range not
3637 * able to find the pages tagged with SetPageError at transaction
3638 * commit time. So if this happens we must abort the transaction,
3639 * otherwise we commit a super block with btree roots that point to
3640 * btree nodes/leafs whose content on disk is invalid - either garbage
3641 * or the content of some node/leaf from a past generation that got
3642 * cowed or deleted and is no longer valid.
3644 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3645 * not be enough - we need to distinguish between log tree extents vs
3646 * non-log tree extents, and the next filemap_fdatawait_range() call
3647 * will catch and clear such errors in the mapping - and that call might
3648 * be from a log sync and not from a transaction commit. Also, checking
3649 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3650 * not done and would not be reliable - the eb might have been released
3651 * from memory and reading it back again means that flag would not be
3652 * set (since it's a runtime flag, not persisted on disk).
3654 * Using the flags below in the btree inode also makes us achieve the
3655 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3656 * writeback for all dirty pages and before filemap_fdatawait_range()
3657 * is called, the writeback for all dirty pages had already finished
3658 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3659 * filemap_fdatawait_range() would return success, as it could not know
3660 * that writeback errors happened (the pages were no longer tagged for
3663 switch (eb->log_index) {
3665 set_bit(BTRFS_FS_BTREE_ERR, &eb->fs_info->flags);
3668 set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags);
3671 set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags);
3674 BUG(); /* unexpected, logic error */
3678 static void end_bio_extent_buffer_writepage(struct bio *bio)
3680 struct bio_vec *bvec;
3681 struct extent_buffer *eb;
3684 ASSERT(!bio_flagged(bio, BIO_CLONED));
3685 bio_for_each_segment_all(bvec, bio, i) {
3686 struct page *page = bvec->bv_page;
3688 eb = (struct extent_buffer *)page->private;
3690 done = atomic_dec_and_test(&eb->io_pages);
3692 if (bio->bi_status ||
3693 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3694 ClearPageUptodate(page);
3695 set_btree_ioerr(page);
3698 end_page_writeback(page);
3703 end_extent_buffer_writeback(eb);
3709 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3710 struct btrfs_fs_info *fs_info,
3711 struct writeback_control *wbc,
3712 struct extent_page_data *epd)
3714 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3715 struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
3716 u64 offset = eb->start;
3718 unsigned long i, num_pages;
3719 unsigned long start, end;
3720 unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META;
3723 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3724 num_pages = num_extent_pages(eb->start, eb->len);
3725 atomic_set(&eb->io_pages, num_pages);
3727 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3728 nritems = btrfs_header_nritems(eb);
3729 if (btrfs_header_level(eb) > 0) {
3730 end = btrfs_node_key_ptr_offset(nritems);
3732 memzero_extent_buffer(eb, end, eb->len - end);
3736 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3738 start = btrfs_item_nr_offset(nritems);
3739 end = BTRFS_LEAF_DATA_OFFSET + leaf_data_end(fs_info, eb);
3740 memzero_extent_buffer(eb, start, end - start);
3743 for (i = 0; i < num_pages; i++) {
3744 struct page *p = eb->pages[i];
3746 clear_page_dirty_for_io(p);
3747 set_page_writeback(p);
3748 ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
3749 p, offset, PAGE_SIZE, 0, bdev,
3751 end_bio_extent_buffer_writepage,
3755 if (PageWriteback(p))
3756 end_page_writeback(p);
3757 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3758 end_extent_buffer_writeback(eb);
3762 offset += PAGE_SIZE;
3763 update_nr_written(wbc, 1);
3767 if (unlikely(ret)) {
3768 for (; i < num_pages; i++) {
3769 struct page *p = eb->pages[i];
3770 clear_page_dirty_for_io(p);
3778 int btree_write_cache_pages(struct address_space *mapping,
3779 struct writeback_control *wbc)
3781 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3782 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3783 struct extent_buffer *eb, *prev_eb = NULL;
3784 struct extent_page_data epd = {
3788 .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);
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_range_tag(&pvec, mapping, &index, end,
3822 for (i = 0; i < nr_pages; i++) {
3823 struct page *page = pvec.pages[i];
3825 if (!PagePrivate(page))
3828 spin_lock(&mapping->private_lock);
3829 if (!PagePrivate(page)) {
3830 spin_unlock(&mapping->private_lock);
3834 eb = (struct extent_buffer *)page->private;
3837 * Shouldn't happen and normally this would be a BUG_ON
3838 * but no sense in crashing the users box for something
3839 * we can survive anyway.
3842 spin_unlock(&mapping->private_lock);
3846 if (eb == prev_eb) {
3847 spin_unlock(&mapping->private_lock);
3851 ret = atomic_inc_not_zero(&eb->refs);
3852 spin_unlock(&mapping->private_lock);
3857 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3859 free_extent_buffer(eb);
3863 ret = write_one_eb(eb, fs_info, wbc, &epd);
3866 free_extent_buffer(eb);
3869 free_extent_buffer(eb);
3872 * the filesystem may choose to bump up nr_to_write.
3873 * We have to make sure to honor the new nr_to_write
3876 nr_to_write_done = wbc->nr_to_write <= 0;
3878 pagevec_release(&pvec);
3881 if (!scanned && !done) {
3883 * We hit the last page and there is more work to be done: wrap
3884 * back to the start of the file
3890 flush_write_bio(&epd);
3895 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3896 * @mapping: address space structure to write
3897 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3898 * @data: data passed to __extent_writepage function
3900 * If a page is already under I/O, write_cache_pages() skips it, even
3901 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3902 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3903 * and msync() need to guarantee that all the data which was dirty at the time
3904 * the call was made get new I/O started against them. If wbc->sync_mode is
3905 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3906 * existing IO to complete.
3908 static int extent_write_cache_pages(struct address_space *mapping,
3909 struct writeback_control *wbc,
3910 struct extent_page_data *epd)
3912 struct inode *inode = mapping->host;
3915 int nr_to_write_done = 0;
3916 struct pagevec pvec;
3919 pgoff_t end; /* Inclusive */
3921 int range_whole = 0;
3926 * We have to hold onto the inode so that ordered extents can do their
3927 * work when the IO finishes. The alternative to this is failing to add
3928 * an ordered extent if the igrab() fails there and that is a huge pain
3929 * to deal with, so instead just hold onto the inode throughout the
3930 * writepages operation. If it fails here we are freeing up the inode
3931 * anyway and we'd rather not waste our time writing out stuff that is
3932 * going to be truncated anyway.
3937 pagevec_init(&pvec);
3938 if (wbc->range_cyclic) {
3939 index = mapping->writeback_index; /* Start from prev offset */
3942 index = wbc->range_start >> PAGE_SHIFT;
3943 end = wbc->range_end >> PAGE_SHIFT;
3944 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
3948 if (wbc->sync_mode == WB_SYNC_ALL)
3949 tag = PAGECACHE_TAG_TOWRITE;
3951 tag = PAGECACHE_TAG_DIRTY;
3953 if (wbc->sync_mode == WB_SYNC_ALL)
3954 tag_pages_for_writeback(mapping, index, end);
3956 while (!done && !nr_to_write_done && (index <= end) &&
3957 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping,
3958 &index, end, tag))) {
3962 for (i = 0; i < nr_pages; i++) {
3963 struct page *page = pvec.pages[i];
3965 done_index = page->index;
3967 * At this point we hold neither the i_pages lock nor
3968 * the page lock: the page may be truncated or
3969 * invalidated (changing page->mapping to NULL),
3970 * or even swizzled back from swapper_space to
3971 * tmpfs file mapping
3973 if (!trylock_page(page)) {
3974 flush_write_bio(epd);
3978 if (unlikely(page->mapping != mapping)) {
3983 if (wbc->sync_mode != WB_SYNC_NONE) {
3984 if (PageWriteback(page))
3985 flush_write_bio(epd);
3986 wait_on_page_writeback(page);
3989 if (PageWriteback(page) ||
3990 !clear_page_dirty_for_io(page)) {
3995 ret = __extent_writepage(page, wbc, epd);
3997 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
4003 * done_index is set past this page,
4004 * so media errors will not choke
4005 * background writeout for the entire
4006 * file. This has consequences for
4007 * range_cyclic semantics (ie. it may
4008 * not be suitable for data integrity
4011 done_index = page->index + 1;
4017 * the filesystem may choose to bump up nr_to_write.
4018 * We have to make sure to honor the new nr_to_write
4021 nr_to_write_done = wbc->nr_to_write <= 0;
4023 pagevec_release(&pvec);
4026 if (!scanned && !done) {
4028 * We hit the last page and there is more work to be done: wrap
4029 * back to the start of the file
4036 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4037 mapping->writeback_index = done_index;
4039 btrfs_add_delayed_iput(inode);
4043 static void flush_write_bio(struct extent_page_data *epd)
4048 ret = submit_one_bio(epd->bio, 0, 0);
4049 BUG_ON(ret < 0); /* -ENOMEM */
4054 int extent_write_full_page(struct page *page, struct writeback_control *wbc)
4057 struct extent_page_data epd = {
4059 .tree = &BTRFS_I(page->mapping->host)->io_tree,
4061 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4064 ret = __extent_writepage(page, wbc, &epd);
4066 flush_write_bio(&epd);
4070 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
4074 struct address_space *mapping = inode->i_mapping;
4075 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
4077 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4080 struct extent_page_data epd = {
4084 .sync_io = mode == WB_SYNC_ALL,
4086 struct writeback_control wbc_writepages = {
4088 .nr_to_write = nr_pages * 2,
4089 .range_start = start,
4090 .range_end = end + 1,
4093 while (start <= end) {
4094 page = find_get_page(mapping, start >> PAGE_SHIFT);
4095 if (clear_page_dirty_for_io(page))
4096 ret = __extent_writepage(page, &wbc_writepages, &epd);
4098 if (tree->ops && tree->ops->writepage_end_io_hook)
4099 tree->ops->writepage_end_io_hook(page, start,
4100 start + PAGE_SIZE - 1,
4108 flush_write_bio(&epd);
4112 int extent_writepages(struct extent_io_tree *tree,
4113 struct address_space *mapping,
4114 struct writeback_control *wbc)
4117 struct extent_page_data epd = {
4121 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4124 ret = extent_write_cache_pages(mapping, wbc, &epd);
4125 flush_write_bio(&epd);
4129 int extent_readpages(struct extent_io_tree *tree,
4130 struct address_space *mapping,
4131 struct list_head *pages, unsigned nr_pages)
4133 struct bio *bio = NULL;
4135 unsigned long bio_flags = 0;
4136 struct page *pagepool[16];
4138 struct extent_map *em_cached = NULL;
4140 u64 prev_em_start = (u64)-1;
4142 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
4143 page = list_entry(pages->prev, struct page, lru);
4145 prefetchw(&page->flags);
4146 list_del(&page->lru);
4147 if (add_to_page_cache_lru(page, mapping,
4149 readahead_gfp_mask(mapping))) {
4154 pagepool[nr++] = page;
4155 if (nr < ARRAY_SIZE(pagepool))
4157 __extent_readpages(tree, pagepool, nr, &em_cached, &bio,
4158 &bio_flags, &prev_em_start);
4162 __extent_readpages(tree, pagepool, nr, &em_cached, &bio,
4163 &bio_flags, &prev_em_start);
4166 free_extent_map(em_cached);
4168 BUG_ON(!list_empty(pages));
4170 return submit_one_bio(bio, 0, bio_flags);
4175 * basic invalidatepage code, this waits on any locked or writeback
4176 * ranges corresponding to the page, and then deletes any extent state
4177 * records from the tree
4179 int extent_invalidatepage(struct extent_io_tree *tree,
4180 struct page *page, unsigned long offset)
4182 struct extent_state *cached_state = NULL;
4183 u64 start = page_offset(page);
4184 u64 end = start + PAGE_SIZE - 1;
4185 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4187 start += ALIGN(offset, blocksize);
4191 lock_extent_bits(tree, start, end, &cached_state);
4192 wait_on_page_writeback(page);
4193 clear_extent_bit(tree, start, end,
4194 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
4195 EXTENT_DO_ACCOUNTING,
4196 1, 1, &cached_state);
4201 * a helper for releasepage, this tests for areas of the page that
4202 * are locked or under IO and drops the related state bits if it is safe
4205 static int try_release_extent_state(struct extent_map_tree *map,
4206 struct extent_io_tree *tree,
4207 struct page *page, gfp_t mask)
4209 u64 start = page_offset(page);
4210 u64 end = start + PAGE_SIZE - 1;
4213 if (test_range_bit(tree, start, end,
4214 EXTENT_IOBITS, 0, NULL))
4218 * at this point we can safely clear everything except the
4219 * locked bit and the nodatasum bit
4221 ret = __clear_extent_bit(tree, start, end,
4222 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4223 0, 0, NULL, mask, NULL);
4225 /* if clear_extent_bit failed for enomem reasons,
4226 * we can't allow the release to continue.
4237 * a helper for releasepage. As long as there are no locked extents
4238 * in the range corresponding to the page, both state records and extent
4239 * map records are removed
4241 int try_release_extent_mapping(struct extent_map_tree *map,
4242 struct extent_io_tree *tree, struct page *page,
4245 struct extent_map *em;
4246 u64 start = page_offset(page);
4247 u64 end = start + PAGE_SIZE - 1;
4249 if (gfpflags_allow_blocking(mask) &&
4250 page->mapping->host->i_size > SZ_16M) {
4252 while (start <= end) {
4253 len = end - start + 1;
4254 write_lock(&map->lock);
4255 em = lookup_extent_mapping(map, start, len);
4257 write_unlock(&map->lock);
4260 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4261 em->start != start) {
4262 write_unlock(&map->lock);
4263 free_extent_map(em);
4266 if (!test_range_bit(tree, em->start,
4267 extent_map_end(em) - 1,
4268 EXTENT_LOCKED | EXTENT_WRITEBACK,
4270 remove_extent_mapping(map, em);
4271 /* once for the rb tree */
4272 free_extent_map(em);
4274 start = extent_map_end(em);
4275 write_unlock(&map->lock);
4278 free_extent_map(em);
4281 return try_release_extent_state(map, tree, page, mask);
4285 * helper function for fiemap, which doesn't want to see any holes.
4286 * This maps until we find something past 'last'
4288 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4289 u64 offset, u64 last)
4291 u64 sectorsize = btrfs_inode_sectorsize(inode);
4292 struct extent_map *em;
4299 len = last - offset;
4302 len = ALIGN(len, sectorsize);
4303 em = btrfs_get_extent_fiemap(BTRFS_I(inode), NULL, 0, offset,
4305 if (IS_ERR_OR_NULL(em))
4308 /* if this isn't a hole return it */
4309 if (em->block_start != EXTENT_MAP_HOLE)
4312 /* this is a hole, advance to the next extent */
4313 offset = extent_map_end(em);
4314 free_extent_map(em);
4322 * To cache previous fiemap extent
4324 * Will be used for merging fiemap extent
4326 struct fiemap_cache {
4335 * Helper to submit fiemap extent.
4337 * Will try to merge current fiemap extent specified by @offset, @phys,
4338 * @len and @flags with cached one.
4339 * And only when we fails to merge, cached one will be submitted as
4342 * Return value is the same as fiemap_fill_next_extent().
4344 static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
4345 struct fiemap_cache *cache,
4346 u64 offset, u64 phys, u64 len, u32 flags)
4354 * Sanity check, extent_fiemap() should have ensured that new
4355 * fiemap extent won't overlap with cahced one.
4358 * NOTE: Physical address can overlap, due to compression
4360 if (cache->offset + cache->len > offset) {
4366 * Only merges fiemap extents if
4367 * 1) Their logical addresses are continuous
4369 * 2) Their physical addresses are continuous
4370 * So truly compressed (physical size smaller than logical size)
4371 * extents won't get merged with each other
4373 * 3) Share same flags except FIEMAP_EXTENT_LAST
4374 * So regular extent won't get merged with prealloc extent
4376 if (cache->offset + cache->len == offset &&
4377 cache->phys + cache->len == phys &&
4378 (cache->flags & ~FIEMAP_EXTENT_LAST) ==
4379 (flags & ~FIEMAP_EXTENT_LAST)) {
4381 cache->flags |= flags;
4382 goto try_submit_last;
4385 /* Not mergeable, need to submit cached one */
4386 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4387 cache->len, cache->flags);
4388 cache->cached = false;
4392 cache->cached = true;
4393 cache->offset = offset;
4396 cache->flags = flags;
4398 if (cache->flags & FIEMAP_EXTENT_LAST) {
4399 ret = fiemap_fill_next_extent(fieinfo, cache->offset,
4400 cache->phys, cache->len, cache->flags);
4401 cache->cached = false;
4407 * Emit last fiemap cache
4409 * The last fiemap cache may still be cached in the following case:
4411 * |<- Fiemap range ->|
4412 * |<------------ First extent ----------->|
4414 * In this case, the first extent range will be cached but not emitted.
4415 * So we must emit it before ending extent_fiemap().
4417 static int emit_last_fiemap_cache(struct btrfs_fs_info *fs_info,
4418 struct fiemap_extent_info *fieinfo,
4419 struct fiemap_cache *cache)
4426 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4427 cache->len, cache->flags);
4428 cache->cached = false;
4434 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4435 __u64 start, __u64 len)
4439 u64 max = start + len;
4443 u64 last_for_get_extent = 0;
4445 u64 isize = i_size_read(inode);
4446 struct btrfs_key found_key;
4447 struct extent_map *em = NULL;
4448 struct extent_state *cached_state = NULL;
4449 struct btrfs_path *path;
4450 struct btrfs_root *root = BTRFS_I(inode)->root;
4451 struct fiemap_cache cache = { 0 };
4460 path = btrfs_alloc_path();
4463 path->leave_spinning = 1;
4465 start = round_down(start, btrfs_inode_sectorsize(inode));
4466 len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
4469 * lookup the last file extent. We're not using i_size here
4470 * because there might be preallocation past i_size
4472 ret = btrfs_lookup_file_extent(NULL, root, path,
4473 btrfs_ino(BTRFS_I(inode)), -1, 0);
4475 btrfs_free_path(path);
4484 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4485 found_type = found_key.type;
4487 /* No extents, but there might be delalloc bits */
4488 if (found_key.objectid != btrfs_ino(BTRFS_I(inode)) ||
4489 found_type != BTRFS_EXTENT_DATA_KEY) {
4490 /* have to trust i_size as the end */
4492 last_for_get_extent = isize;
4495 * remember the start of the last extent. There are a
4496 * bunch of different factors that go into the length of the
4497 * extent, so its much less complex to remember where it started
4499 last = found_key.offset;
4500 last_for_get_extent = last + 1;
4502 btrfs_release_path(path);
4505 * we might have some extents allocated but more delalloc past those
4506 * extents. so, we trust isize unless the start of the last extent is
4511 last_for_get_extent = isize;
4514 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4517 em = get_extent_skip_holes(inode, start, last_for_get_extent);
4526 u64 offset_in_extent = 0;
4528 /* break if the extent we found is outside the range */
4529 if (em->start >= max || extent_map_end(em) < off)
4533 * get_extent may return an extent that starts before our
4534 * requested range. We have to make sure the ranges
4535 * we return to fiemap always move forward and don't
4536 * overlap, so adjust the offsets here
4538 em_start = max(em->start, off);
4541 * record the offset from the start of the extent
4542 * for adjusting the disk offset below. Only do this if the
4543 * extent isn't compressed since our in ram offset may be past
4544 * what we have actually allocated on disk.
4546 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4547 offset_in_extent = em_start - em->start;
4548 em_end = extent_map_end(em);
4549 em_len = em_end - em_start;
4554 * bump off for our next call to get_extent
4556 off = extent_map_end(em);
4560 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4562 flags |= FIEMAP_EXTENT_LAST;
4563 } else if (em->block_start == EXTENT_MAP_INLINE) {
4564 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4565 FIEMAP_EXTENT_NOT_ALIGNED);
4566 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4567 flags |= (FIEMAP_EXTENT_DELALLOC |
4568 FIEMAP_EXTENT_UNKNOWN);
4569 } else if (fieinfo->fi_extents_max) {
4570 u64 bytenr = em->block_start -
4571 (em->start - em->orig_start);
4573 disko = em->block_start + offset_in_extent;
4576 * As btrfs supports shared space, this information
4577 * can be exported to userspace tools via
4578 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4579 * then we're just getting a count and we can skip the
4582 ret = btrfs_check_shared(root,
4583 btrfs_ino(BTRFS_I(inode)),
4588 flags |= FIEMAP_EXTENT_SHARED;
4591 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4592 flags |= FIEMAP_EXTENT_ENCODED;
4593 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4594 flags |= FIEMAP_EXTENT_UNWRITTEN;
4596 free_extent_map(em);
4598 if ((em_start >= last) || em_len == (u64)-1 ||
4599 (last == (u64)-1 && isize <= em_end)) {
4600 flags |= FIEMAP_EXTENT_LAST;
4604 /* now scan forward to see if this is really the last extent. */
4605 em = get_extent_skip_holes(inode, off, last_for_get_extent);
4611 flags |= FIEMAP_EXTENT_LAST;
4614 ret = emit_fiemap_extent(fieinfo, &cache, em_start, disko,
4624 ret = emit_last_fiemap_cache(root->fs_info, fieinfo, &cache);
4625 free_extent_map(em);
4627 btrfs_free_path(path);
4628 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4633 static void __free_extent_buffer(struct extent_buffer *eb)
4635 btrfs_leak_debug_del(&eb->leak_list);
4636 kmem_cache_free(extent_buffer_cache, eb);
4639 int extent_buffer_under_io(struct extent_buffer *eb)
4641 return (atomic_read(&eb->io_pages) ||
4642 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4643 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4647 * Helper for releasing extent buffer page.
4649 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb)
4651 unsigned long index;
4653 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4655 BUG_ON(extent_buffer_under_io(eb));
4657 index = num_extent_pages(eb->start, eb->len);
4663 page = eb->pages[index];
4667 spin_lock(&page->mapping->private_lock);
4669 * We do this since we'll remove the pages after we've
4670 * removed the eb from the radix tree, so we could race
4671 * and have this page now attached to the new eb. So
4672 * only clear page_private if it's still connected to
4675 if (PagePrivate(page) &&
4676 page->private == (unsigned long)eb) {
4677 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4678 BUG_ON(PageDirty(page));
4679 BUG_ON(PageWriteback(page));
4681 * We need to make sure we haven't be attached
4684 ClearPagePrivate(page);
4685 set_page_private(page, 0);
4686 /* One for the page private */
4691 spin_unlock(&page->mapping->private_lock);
4693 /* One for when we allocated the page */
4695 } while (index != 0);
4699 * Helper for releasing the extent buffer.
4701 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4703 btrfs_release_extent_buffer_page(eb);
4704 __free_extent_buffer(eb);
4707 static struct extent_buffer *
4708 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4711 struct extent_buffer *eb = NULL;
4713 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4716 eb->fs_info = fs_info;
4718 rwlock_init(&eb->lock);
4719 atomic_set(&eb->write_locks, 0);
4720 atomic_set(&eb->read_locks, 0);
4721 atomic_set(&eb->blocking_readers, 0);
4722 atomic_set(&eb->blocking_writers, 0);
4723 atomic_set(&eb->spinning_readers, 0);
4724 atomic_set(&eb->spinning_writers, 0);
4725 eb->lock_nested = 0;
4726 init_waitqueue_head(&eb->write_lock_wq);
4727 init_waitqueue_head(&eb->read_lock_wq);
4729 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4731 spin_lock_init(&eb->refs_lock);
4732 atomic_set(&eb->refs, 1);
4733 atomic_set(&eb->io_pages, 0);
4736 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4738 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4739 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4740 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4745 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4749 struct extent_buffer *new;
4750 unsigned long num_pages = num_extent_pages(src->start, src->len);
4752 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
4756 for (i = 0; i < num_pages; i++) {
4757 p = alloc_page(GFP_NOFS);
4759 btrfs_release_extent_buffer(new);
4762 attach_extent_buffer_page(new, p);
4763 WARN_ON(PageDirty(p));
4766 copy_page(page_address(p), page_address(src->pages[i]));
4769 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4770 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4775 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4776 u64 start, unsigned long len)
4778 struct extent_buffer *eb;
4779 unsigned long num_pages;
4782 num_pages = num_extent_pages(start, len);
4784 eb = __alloc_extent_buffer(fs_info, start, len);
4788 for (i = 0; i < num_pages; i++) {
4789 eb->pages[i] = alloc_page(GFP_NOFS);
4793 set_extent_buffer_uptodate(eb);
4794 btrfs_set_header_nritems(eb, 0);
4795 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4800 __free_page(eb->pages[i - 1]);
4801 __free_extent_buffer(eb);
4805 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4808 return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
4811 static void check_buffer_tree_ref(struct extent_buffer *eb)
4814 /* the ref bit is tricky. We have to make sure it is set
4815 * if we have the buffer dirty. Otherwise the
4816 * code to free a buffer can end up dropping a dirty
4819 * Once the ref bit is set, it won't go away while the
4820 * buffer is dirty or in writeback, and it also won't
4821 * go away while we have the reference count on the
4824 * We can't just set the ref bit without bumping the
4825 * ref on the eb because free_extent_buffer might
4826 * see the ref bit and try to clear it. If this happens
4827 * free_extent_buffer might end up dropping our original
4828 * ref by mistake and freeing the page before we are able
4829 * to add one more ref.
4831 * So bump the ref count first, then set the bit. If someone
4832 * beat us to it, drop the ref we added.
4834 refs = atomic_read(&eb->refs);
4835 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4838 spin_lock(&eb->refs_lock);
4839 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4840 atomic_inc(&eb->refs);
4841 spin_unlock(&eb->refs_lock);
4844 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
4845 struct page *accessed)
4847 unsigned long num_pages, i;
4849 check_buffer_tree_ref(eb);
4851 num_pages = num_extent_pages(eb->start, eb->len);
4852 for (i = 0; i < num_pages; i++) {
4853 struct page *p = eb->pages[i];
4856 mark_page_accessed(p);
4860 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
4863 struct extent_buffer *eb;
4866 eb = radix_tree_lookup(&fs_info->buffer_radix,
4867 start >> PAGE_SHIFT);
4868 if (eb && atomic_inc_not_zero(&eb->refs)) {
4871 * Lock our eb's refs_lock to avoid races with
4872 * free_extent_buffer. When we get our eb it might be flagged
4873 * with EXTENT_BUFFER_STALE and another task running
4874 * free_extent_buffer might have seen that flag set,
4875 * eb->refs == 2, that the buffer isn't under IO (dirty and
4876 * writeback flags not set) and it's still in the tree (flag
4877 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4878 * of decrementing the extent buffer's reference count twice.
4879 * So here we could race and increment the eb's reference count,
4880 * clear its stale flag, mark it as dirty and drop our reference
4881 * before the other task finishes executing free_extent_buffer,
4882 * which would later result in an attempt to free an extent
4883 * buffer that is dirty.
4885 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
4886 spin_lock(&eb->refs_lock);
4887 spin_unlock(&eb->refs_lock);
4889 mark_extent_buffer_accessed(eb, NULL);
4897 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4898 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
4901 struct extent_buffer *eb, *exists = NULL;
4904 eb = find_extent_buffer(fs_info, start);
4907 eb = alloc_dummy_extent_buffer(fs_info, start);
4910 eb->fs_info = fs_info;
4912 ret = radix_tree_preload(GFP_NOFS);
4915 spin_lock(&fs_info->buffer_lock);
4916 ret = radix_tree_insert(&fs_info->buffer_radix,
4917 start >> PAGE_SHIFT, eb);
4918 spin_unlock(&fs_info->buffer_lock);
4919 radix_tree_preload_end();
4920 if (ret == -EEXIST) {
4921 exists = find_extent_buffer(fs_info, start);
4927 check_buffer_tree_ref(eb);
4928 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4931 * We will free dummy extent buffer's if they come into
4932 * free_extent_buffer with a ref count of 2, but if we are using this we
4933 * want the buffers to stay in memory until we're done with them, so
4934 * bump the ref count again.
4936 atomic_inc(&eb->refs);
4939 btrfs_release_extent_buffer(eb);
4944 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
4947 unsigned long len = fs_info->nodesize;
4948 unsigned long num_pages = num_extent_pages(start, len);
4950 unsigned long index = start >> PAGE_SHIFT;
4951 struct extent_buffer *eb;
4952 struct extent_buffer *exists = NULL;
4954 struct address_space *mapping = fs_info->btree_inode->i_mapping;
4958 if (!IS_ALIGNED(start, fs_info->sectorsize)) {
4959 btrfs_err(fs_info, "bad tree block start %llu", start);
4960 return ERR_PTR(-EINVAL);
4963 eb = find_extent_buffer(fs_info, start);
4967 eb = __alloc_extent_buffer(fs_info, start, len);
4969 return ERR_PTR(-ENOMEM);
4971 for (i = 0; i < num_pages; i++, index++) {
4972 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
4974 exists = ERR_PTR(-ENOMEM);
4978 spin_lock(&mapping->private_lock);
4979 if (PagePrivate(p)) {
4981 * We could have already allocated an eb for this page
4982 * and attached one so lets see if we can get a ref on
4983 * the existing eb, and if we can we know it's good and
4984 * we can just return that one, else we know we can just
4985 * overwrite page->private.
4987 exists = (struct extent_buffer *)p->private;
4988 if (atomic_inc_not_zero(&exists->refs)) {
4989 spin_unlock(&mapping->private_lock);
4992 mark_extent_buffer_accessed(exists, p);
4998 * Do this so attach doesn't complain and we need to
4999 * drop the ref the old guy had.
5001 ClearPagePrivate(p);
5002 WARN_ON(PageDirty(p));
5005 attach_extent_buffer_page(eb, p);
5006 spin_unlock(&mapping->private_lock);
5007 WARN_ON(PageDirty(p));
5009 if (!PageUptodate(p))
5013 * see below about how we avoid a nasty race with release page
5014 * and why we unlock later
5018 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5020 ret = radix_tree_preload(GFP_NOFS);
5022 exists = ERR_PTR(ret);
5026 spin_lock(&fs_info->buffer_lock);
5027 ret = radix_tree_insert(&fs_info->buffer_radix,
5028 start >> PAGE_SHIFT, eb);
5029 spin_unlock(&fs_info->buffer_lock);
5030 radix_tree_preload_end();
5031 if (ret == -EEXIST) {
5032 exists = find_extent_buffer(fs_info, start);
5038 /* add one reference for the tree */
5039 check_buffer_tree_ref(eb);
5040 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5043 * there is a race where release page may have
5044 * tried to find this extent buffer in the radix
5045 * but failed. It will tell the VM it is safe to
5046 * reclaim the, and it will clear the page private bit.
5047 * We must make sure to set the page private bit properly
5048 * after the extent buffer is in the radix tree so
5049 * it doesn't get lost
5051 SetPageChecked(eb->pages[0]);
5052 for (i = 1; i < num_pages; i++) {
5054 ClearPageChecked(p);
5057 unlock_page(eb->pages[0]);
5061 WARN_ON(!atomic_dec_and_test(&eb->refs));
5062 for (i = 0; i < num_pages; i++) {
5064 unlock_page(eb->pages[i]);
5067 btrfs_release_extent_buffer(eb);
5071 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5073 struct extent_buffer *eb =
5074 container_of(head, struct extent_buffer, rcu_head);
5076 __free_extent_buffer(eb);
5079 /* Expects to have eb->eb_lock already held */
5080 static int release_extent_buffer(struct extent_buffer *eb)
5082 WARN_ON(atomic_read(&eb->refs) == 0);
5083 if (atomic_dec_and_test(&eb->refs)) {
5084 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5085 struct btrfs_fs_info *fs_info = eb->fs_info;
5087 spin_unlock(&eb->refs_lock);
5089 spin_lock(&fs_info->buffer_lock);
5090 radix_tree_delete(&fs_info->buffer_radix,
5091 eb->start >> PAGE_SHIFT);
5092 spin_unlock(&fs_info->buffer_lock);
5094 spin_unlock(&eb->refs_lock);
5097 /* Should be safe to release our pages at this point */
5098 btrfs_release_extent_buffer_page(eb);
5099 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5100 if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) {
5101 __free_extent_buffer(eb);
5105 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5108 spin_unlock(&eb->refs_lock);
5113 void free_extent_buffer(struct extent_buffer *eb)
5121 refs = atomic_read(&eb->refs);
5124 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5129 spin_lock(&eb->refs_lock);
5130 if (atomic_read(&eb->refs) == 2 &&
5131 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
5132 atomic_dec(&eb->refs);
5134 if (atomic_read(&eb->refs) == 2 &&
5135 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5136 !extent_buffer_under_io(eb) &&
5137 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5138 atomic_dec(&eb->refs);
5141 * I know this is terrible, but it's temporary until we stop tracking
5142 * the uptodate bits and such for the extent buffers.
5144 release_extent_buffer(eb);
5147 void free_extent_buffer_stale(struct extent_buffer *eb)
5152 spin_lock(&eb->refs_lock);
5153 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5155 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5156 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5157 atomic_dec(&eb->refs);
5158 release_extent_buffer(eb);
5161 void clear_extent_buffer_dirty(struct extent_buffer *eb)
5164 unsigned long num_pages;
5167 num_pages = num_extent_pages(eb->start, eb->len);
5169 for (i = 0; i < num_pages; i++) {
5170 page = eb->pages[i];
5171 if (!PageDirty(page))
5175 WARN_ON(!PagePrivate(page));
5177 clear_page_dirty_for_io(page);
5178 xa_lock_irq(&page->mapping->i_pages);
5179 if (!PageDirty(page)) {
5180 radix_tree_tag_clear(&page->mapping->i_pages,
5182 PAGECACHE_TAG_DIRTY);
5184 xa_unlock_irq(&page->mapping->i_pages);
5185 ClearPageError(page);
5188 WARN_ON(atomic_read(&eb->refs) == 0);
5191 int set_extent_buffer_dirty(struct extent_buffer *eb)
5194 unsigned long num_pages;
5197 check_buffer_tree_ref(eb);
5199 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5201 num_pages = num_extent_pages(eb->start, eb->len);
5202 WARN_ON(atomic_read(&eb->refs) == 0);
5203 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5205 for (i = 0; i < num_pages; i++)
5206 set_page_dirty(eb->pages[i]);
5210 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5214 unsigned long num_pages;
5216 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5217 num_pages = num_extent_pages(eb->start, eb->len);
5218 for (i = 0; i < num_pages; i++) {
5219 page = eb->pages[i];
5221 ClearPageUptodate(page);
5225 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5229 unsigned long num_pages;
5231 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5232 num_pages = num_extent_pages(eb->start, eb->len);
5233 for (i = 0; i < num_pages; i++) {
5234 page = eb->pages[i];
5235 SetPageUptodate(page);
5239 int read_extent_buffer_pages(struct extent_io_tree *tree,
5240 struct extent_buffer *eb, int wait, int mirror_num)
5246 int locked_pages = 0;
5247 int all_uptodate = 1;
5248 unsigned long num_pages;
5249 unsigned long num_reads = 0;
5250 struct bio *bio = NULL;
5251 unsigned long bio_flags = 0;
5253 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5256 num_pages = num_extent_pages(eb->start, eb->len);
5257 for (i = 0; i < num_pages; i++) {
5258 page = eb->pages[i];
5259 if (wait == WAIT_NONE) {
5260 if (!trylock_page(page))
5268 * We need to firstly lock all pages to make sure that
5269 * the uptodate bit of our pages won't be affected by
5270 * clear_extent_buffer_uptodate().
5272 for (i = 0; i < num_pages; i++) {
5273 page = eb->pages[i];
5274 if (!PageUptodate(page)) {
5281 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5285 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5286 eb->read_mirror = 0;
5287 atomic_set(&eb->io_pages, num_reads);
5288 for (i = 0; i < num_pages; i++) {
5289 page = eb->pages[i];
5291 if (!PageUptodate(page)) {
5293 atomic_dec(&eb->io_pages);
5298 ClearPageError(page);
5299 err = __extent_read_full_page(tree, page,
5300 btree_get_extent, &bio,
5301 mirror_num, &bio_flags,
5306 * We use &bio in above __extent_read_full_page,
5307 * so we ensure that if it returns error, the
5308 * current page fails to add itself to bio and
5309 * it's been unlocked.
5311 * We must dec io_pages by ourselves.
5313 atomic_dec(&eb->io_pages);
5321 err = submit_one_bio(bio, mirror_num, bio_flags);
5326 if (ret || wait != WAIT_COMPLETE)
5329 for (i = 0; i < num_pages; i++) {
5330 page = eb->pages[i];
5331 wait_on_page_locked(page);
5332 if (!PageUptodate(page))
5339 while (locked_pages > 0) {
5341 page = eb->pages[locked_pages];
5347 void read_extent_buffer(const struct extent_buffer *eb, void *dstv,
5348 unsigned long start, unsigned long len)
5354 char *dst = (char *)dstv;
5355 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5356 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5358 if (start + len > eb->len) {
5359 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5360 eb->start, eb->len, start, len);
5361 memset(dst, 0, len);
5365 offset = (start_offset + start) & (PAGE_SIZE - 1);
5368 page = eb->pages[i];
5370 cur = min(len, (PAGE_SIZE - offset));
5371 kaddr = page_address(page);
5372 memcpy(dst, kaddr + offset, cur);
5381 int read_extent_buffer_to_user(const struct extent_buffer *eb,
5383 unsigned long start, unsigned long len)
5389 char __user *dst = (char __user *)dstv;
5390 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5391 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5394 WARN_ON(start > eb->len);
5395 WARN_ON(start + len > eb->start + eb->len);
5397 offset = (start_offset + start) & (PAGE_SIZE - 1);
5400 page = eb->pages[i];
5402 cur = min(len, (PAGE_SIZE - offset));
5403 kaddr = page_address(page);
5404 if (copy_to_user(dst, kaddr + offset, cur)) {
5419 * return 0 if the item is found within a page.
5420 * return 1 if the item spans two pages.
5421 * return -EINVAL otherwise.
5423 int map_private_extent_buffer(const struct extent_buffer *eb,
5424 unsigned long start, unsigned long min_len,
5425 char **map, unsigned long *map_start,
5426 unsigned long *map_len)
5428 size_t offset = start & (PAGE_SIZE - 1);
5431 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5432 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5433 unsigned long end_i = (start_offset + start + min_len - 1) >>
5436 if (start + min_len > eb->len) {
5437 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5438 eb->start, eb->len, start, min_len);
5446 offset = start_offset;
5450 *map_start = ((u64)i << PAGE_SHIFT) - start_offset;
5454 kaddr = page_address(p);
5455 *map = kaddr + offset;
5456 *map_len = PAGE_SIZE - offset;
5460 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
5461 unsigned long start, unsigned long len)
5467 char *ptr = (char *)ptrv;
5468 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5469 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5472 WARN_ON(start > eb->len);
5473 WARN_ON(start + len > eb->start + eb->len);
5475 offset = (start_offset + start) & (PAGE_SIZE - 1);
5478 page = eb->pages[i];
5480 cur = min(len, (PAGE_SIZE - offset));
5482 kaddr = page_address(page);
5483 ret = memcmp(ptr, kaddr + offset, cur);
5495 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
5500 WARN_ON(!PageUptodate(eb->pages[0]));
5501 kaddr = page_address(eb->pages[0]);
5502 memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
5506 void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)
5510 WARN_ON(!PageUptodate(eb->pages[0]));
5511 kaddr = page_address(eb->pages[0]);
5512 memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
5516 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
5517 unsigned long start, unsigned long len)
5523 char *src = (char *)srcv;
5524 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5525 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5527 WARN_ON(start > eb->len);
5528 WARN_ON(start + len > eb->start + eb->len);
5530 offset = (start_offset + start) & (PAGE_SIZE - 1);
5533 page = eb->pages[i];
5534 WARN_ON(!PageUptodate(page));
5536 cur = min(len, PAGE_SIZE - offset);
5537 kaddr = page_address(page);
5538 memcpy(kaddr + offset, src, cur);
5547 void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
5554 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5555 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5557 WARN_ON(start > eb->len);
5558 WARN_ON(start + len > eb->start + eb->len);
5560 offset = (start_offset + start) & (PAGE_SIZE - 1);
5563 page = eb->pages[i];
5564 WARN_ON(!PageUptodate(page));
5566 cur = min(len, PAGE_SIZE - offset);
5567 kaddr = page_address(page);
5568 memset(kaddr + offset, 0, cur);
5576 void copy_extent_buffer_full(struct extent_buffer *dst,
5577 struct extent_buffer *src)
5582 ASSERT(dst->len == src->len);
5584 num_pages = num_extent_pages(dst->start, dst->len);
5585 for (i = 0; i < num_pages; i++)
5586 copy_page(page_address(dst->pages[i]),
5587 page_address(src->pages[i]));
5590 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5591 unsigned long dst_offset, unsigned long src_offset,
5594 u64 dst_len = dst->len;
5599 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5600 unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
5602 WARN_ON(src->len != dst_len);
5604 offset = (start_offset + dst_offset) &
5608 page = dst->pages[i];
5609 WARN_ON(!PageUptodate(page));
5611 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5613 kaddr = page_address(page);
5614 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5623 void le_bitmap_set(u8 *map, unsigned int start, int len)
5625 u8 *p = map + BIT_BYTE(start);
5626 const unsigned int size = start + len;
5627 int bits_to_set = BITS_PER_BYTE - (start % BITS_PER_BYTE);
5628 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(start);
5630 while (len - bits_to_set >= 0) {
5633 bits_to_set = BITS_PER_BYTE;
5638 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5643 void le_bitmap_clear(u8 *map, unsigned int start, int len)
5645 u8 *p = map + BIT_BYTE(start);
5646 const unsigned int size = start + len;
5647 int bits_to_clear = BITS_PER_BYTE - (start % BITS_PER_BYTE);
5648 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(start);
5650 while (len - bits_to_clear >= 0) {
5651 *p &= ~mask_to_clear;
5652 len -= bits_to_clear;
5653 bits_to_clear = BITS_PER_BYTE;
5658 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5659 *p &= ~mask_to_clear;
5664 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5666 * @eb: the extent buffer
5667 * @start: offset of the bitmap item in the extent buffer
5669 * @page_index: return index of the page in the extent buffer that contains the
5671 * @page_offset: return offset into the page given by page_index
5673 * This helper hides the ugliness of finding the byte in an extent buffer which
5674 * contains a given bit.
5676 static inline void eb_bitmap_offset(struct extent_buffer *eb,
5677 unsigned long start, unsigned long nr,
5678 unsigned long *page_index,
5679 size_t *page_offset)
5681 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5682 size_t byte_offset = BIT_BYTE(nr);
5686 * The byte we want is the offset of the extent buffer + the offset of
5687 * the bitmap item in the extent buffer + the offset of the byte in the
5690 offset = start_offset + start + byte_offset;
5692 *page_index = offset >> PAGE_SHIFT;
5693 *page_offset = offset & (PAGE_SIZE - 1);
5697 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5698 * @eb: the extent buffer
5699 * @start: offset of the bitmap item in the extent buffer
5700 * @nr: bit number to test
5702 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
5710 eb_bitmap_offset(eb, start, nr, &i, &offset);
5711 page = eb->pages[i];
5712 WARN_ON(!PageUptodate(page));
5713 kaddr = page_address(page);
5714 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5718 * extent_buffer_bitmap_set - set an area of a bitmap
5719 * @eb: the extent buffer
5720 * @start: offset of the bitmap item in the extent buffer
5721 * @pos: bit number of the first bit
5722 * @len: number of bits to set
5724 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
5725 unsigned long pos, unsigned long len)
5731 const unsigned int size = pos + len;
5732 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5733 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5735 eb_bitmap_offset(eb, start, pos, &i, &offset);
5736 page = eb->pages[i];
5737 WARN_ON(!PageUptodate(page));
5738 kaddr = page_address(page);
5740 while (len >= bits_to_set) {
5741 kaddr[offset] |= mask_to_set;
5743 bits_to_set = BITS_PER_BYTE;
5745 if (++offset >= PAGE_SIZE && len > 0) {
5747 page = eb->pages[++i];
5748 WARN_ON(!PageUptodate(page));
5749 kaddr = page_address(page);
5753 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5754 kaddr[offset] |= mask_to_set;
5760 * extent_buffer_bitmap_clear - clear an area of a bitmap
5761 * @eb: the extent buffer
5762 * @start: offset of the bitmap item in the extent buffer
5763 * @pos: bit number of the first bit
5764 * @len: number of bits to clear
5766 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
5767 unsigned long pos, unsigned long len)
5773 const unsigned int size = pos + len;
5774 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5775 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5777 eb_bitmap_offset(eb, start, pos, &i, &offset);
5778 page = eb->pages[i];
5779 WARN_ON(!PageUptodate(page));
5780 kaddr = page_address(page);
5782 while (len >= bits_to_clear) {
5783 kaddr[offset] &= ~mask_to_clear;
5784 len -= bits_to_clear;
5785 bits_to_clear = BITS_PER_BYTE;
5787 if (++offset >= PAGE_SIZE && len > 0) {
5789 page = eb->pages[++i];
5790 WARN_ON(!PageUptodate(page));
5791 kaddr = page_address(page);
5795 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5796 kaddr[offset] &= ~mask_to_clear;
5800 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5802 unsigned long distance = (src > dst) ? src - dst : dst - src;
5803 return distance < len;
5806 static void copy_pages(struct page *dst_page, struct page *src_page,
5807 unsigned long dst_off, unsigned long src_off,
5810 char *dst_kaddr = page_address(dst_page);
5812 int must_memmove = 0;
5814 if (dst_page != src_page) {
5815 src_kaddr = page_address(src_page);
5817 src_kaddr = dst_kaddr;
5818 if (areas_overlap(src_off, dst_off, len))
5823 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5825 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5828 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5829 unsigned long src_offset, unsigned long len)
5831 struct btrfs_fs_info *fs_info = dst->fs_info;
5833 size_t dst_off_in_page;
5834 size_t src_off_in_page;
5835 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5836 unsigned long dst_i;
5837 unsigned long src_i;
5839 if (src_offset + len > dst->len) {
5841 "memmove bogus src_offset %lu move len %lu dst len %lu",
5842 src_offset, len, dst->len);
5845 if (dst_offset + len > dst->len) {
5847 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5848 dst_offset, len, dst->len);
5853 dst_off_in_page = (start_offset + dst_offset) &
5855 src_off_in_page = (start_offset + src_offset) &
5858 dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
5859 src_i = (start_offset + src_offset) >> PAGE_SHIFT;
5861 cur = min(len, (unsigned long)(PAGE_SIZE -
5863 cur = min_t(unsigned long, cur,
5864 (unsigned long)(PAGE_SIZE - dst_off_in_page));
5866 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5867 dst_off_in_page, src_off_in_page, cur);
5875 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5876 unsigned long src_offset, unsigned long len)
5878 struct btrfs_fs_info *fs_info = dst->fs_info;
5880 size_t dst_off_in_page;
5881 size_t src_off_in_page;
5882 unsigned long dst_end = dst_offset + len - 1;
5883 unsigned long src_end = src_offset + len - 1;
5884 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5885 unsigned long dst_i;
5886 unsigned long src_i;
5888 if (src_offset + len > dst->len) {
5890 "memmove bogus src_offset %lu move len %lu len %lu",
5891 src_offset, len, dst->len);
5894 if (dst_offset + len > dst->len) {
5896 "memmove bogus dst_offset %lu move len %lu len %lu",
5897 dst_offset, len, dst->len);
5900 if (dst_offset < src_offset) {
5901 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5905 dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
5906 src_i = (start_offset + src_end) >> PAGE_SHIFT;
5908 dst_off_in_page = (start_offset + dst_end) &
5910 src_off_in_page = (start_offset + src_end) &
5913 cur = min_t(unsigned long, len, src_off_in_page + 1);
5914 cur = min(cur, dst_off_in_page + 1);
5915 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5916 dst_off_in_page - cur + 1,
5917 src_off_in_page - cur + 1, cur);
5925 int try_release_extent_buffer(struct page *page)
5927 struct extent_buffer *eb;
5930 * We need to make sure nobody is attaching this page to an eb right
5933 spin_lock(&page->mapping->private_lock);
5934 if (!PagePrivate(page)) {
5935 spin_unlock(&page->mapping->private_lock);
5939 eb = (struct extent_buffer *)page->private;
5943 * This is a little awful but should be ok, we need to make sure that
5944 * the eb doesn't disappear out from under us while we're looking at
5947 spin_lock(&eb->refs_lock);
5948 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5949 spin_unlock(&eb->refs_lock);
5950 spin_unlock(&page->mapping->private_lock);
5953 spin_unlock(&page->mapping->private_lock);
5956 * If tree ref isn't set then we know the ref on this eb is a real ref,
5957 * so just return, this page will likely be freed soon anyway.
5959 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5960 spin_unlock(&eb->refs_lock);
5964 return release_extent_buffer(eb);