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 int __init extent_io_init(void)
145 extent_state_cache = kmem_cache_create("btrfs_extent_state",
146 sizeof(struct extent_state), 0,
147 SLAB_MEM_SPREAD, NULL);
148 if (!extent_state_cache)
151 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
152 sizeof(struct extent_buffer), 0,
153 SLAB_MEM_SPREAD, NULL);
154 if (!extent_buffer_cache)
155 goto free_state_cache;
157 if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE,
158 offsetof(struct btrfs_io_bio, bio),
160 goto free_buffer_cache;
162 if (bioset_integrity_create(&btrfs_bioset, BIO_POOL_SIZE))
168 bioset_exit(&btrfs_bioset);
171 kmem_cache_destroy(extent_buffer_cache);
172 extent_buffer_cache = NULL;
175 kmem_cache_destroy(extent_state_cache);
176 extent_state_cache = NULL;
180 void __cold extent_io_exit(void)
182 btrfs_leak_debug_check();
185 * Make sure all delayed rcu free are flushed before we
189 kmem_cache_destroy(extent_state_cache);
190 kmem_cache_destroy(extent_buffer_cache);
191 bioset_exit(&btrfs_bioset);
194 void extent_io_tree_init(struct extent_io_tree *tree,
197 tree->state = RB_ROOT;
199 tree->dirty_bytes = 0;
200 spin_lock_init(&tree->lock);
201 tree->private_data = private_data;
204 static struct extent_state *alloc_extent_state(gfp_t mask)
206 struct extent_state *state;
209 * The given mask might be not appropriate for the slab allocator,
210 * drop the unsupported bits
212 mask &= ~(__GFP_DMA32|__GFP_HIGHMEM);
213 state = kmem_cache_alloc(extent_state_cache, mask);
217 state->failrec = NULL;
218 RB_CLEAR_NODE(&state->rb_node);
219 btrfs_leak_debug_add(&state->leak_list, &states);
220 refcount_set(&state->refs, 1);
221 init_waitqueue_head(&state->wq);
222 trace_alloc_extent_state(state, mask, _RET_IP_);
226 void free_extent_state(struct extent_state *state)
230 if (refcount_dec_and_test(&state->refs)) {
231 WARN_ON(extent_state_in_tree(state));
232 btrfs_leak_debug_del(&state->leak_list);
233 trace_free_extent_state(state, _RET_IP_);
234 kmem_cache_free(extent_state_cache, state);
238 static struct rb_node *tree_insert(struct rb_root *root,
239 struct rb_node *search_start,
241 struct rb_node *node,
242 struct rb_node ***p_in,
243 struct rb_node **parent_in)
246 struct rb_node *parent = NULL;
247 struct tree_entry *entry;
249 if (p_in && parent_in) {
255 p = search_start ? &search_start : &root->rb_node;
258 entry = rb_entry(parent, struct tree_entry, rb_node);
260 if (offset < entry->start)
262 else if (offset > entry->end)
269 rb_link_node(node, parent, p);
270 rb_insert_color(node, root);
274 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
275 struct rb_node **prev_ret,
276 struct rb_node **next_ret,
277 struct rb_node ***p_ret,
278 struct rb_node **parent_ret)
280 struct rb_root *root = &tree->state;
281 struct rb_node **n = &root->rb_node;
282 struct rb_node *prev = NULL;
283 struct rb_node *orig_prev = NULL;
284 struct tree_entry *entry;
285 struct tree_entry *prev_entry = NULL;
289 entry = rb_entry(prev, struct tree_entry, rb_node);
292 if (offset < entry->start)
294 else if (offset > entry->end)
307 while (prev && offset > prev_entry->end) {
308 prev = rb_next(prev);
309 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
316 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
317 while (prev && offset < prev_entry->start) {
318 prev = rb_prev(prev);
319 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
326 static inline struct rb_node *
327 tree_search_for_insert(struct extent_io_tree *tree,
329 struct rb_node ***p_ret,
330 struct rb_node **parent_ret)
332 struct rb_node *prev = NULL;
335 ret = __etree_search(tree, offset, &prev, NULL, p_ret, parent_ret);
341 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
344 return tree_search_for_insert(tree, offset, NULL, NULL);
347 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
348 struct extent_state *other)
350 if (tree->ops && tree->ops->merge_extent_hook)
351 tree->ops->merge_extent_hook(tree->private_data, new, other);
355 * utility function to look for merge candidates inside a given range.
356 * Any extents with matching state are merged together into a single
357 * extent in the tree. Extents with EXTENT_IO in their state field
358 * are not merged because the end_io handlers need to be able to do
359 * operations on them without sleeping (or doing allocations/splits).
361 * This should be called with the tree lock held.
363 static void merge_state(struct extent_io_tree *tree,
364 struct extent_state *state)
366 struct extent_state *other;
367 struct rb_node *other_node;
369 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
372 other_node = rb_prev(&state->rb_node);
374 other = rb_entry(other_node, struct extent_state, rb_node);
375 if (other->end == state->start - 1 &&
376 other->state == state->state) {
377 merge_cb(tree, state, other);
378 state->start = other->start;
379 rb_erase(&other->rb_node, &tree->state);
380 RB_CLEAR_NODE(&other->rb_node);
381 free_extent_state(other);
384 other_node = rb_next(&state->rb_node);
386 other = rb_entry(other_node, struct extent_state, rb_node);
387 if (other->start == state->end + 1 &&
388 other->state == state->state) {
389 merge_cb(tree, state, other);
390 state->end = other->end;
391 rb_erase(&other->rb_node, &tree->state);
392 RB_CLEAR_NODE(&other->rb_node);
393 free_extent_state(other);
398 static void set_state_cb(struct extent_io_tree *tree,
399 struct extent_state *state, unsigned *bits)
401 if (tree->ops && tree->ops->set_bit_hook)
402 tree->ops->set_bit_hook(tree->private_data, state, bits);
405 static void clear_state_cb(struct extent_io_tree *tree,
406 struct extent_state *state, unsigned *bits)
408 if (tree->ops && tree->ops->clear_bit_hook)
409 tree->ops->clear_bit_hook(tree->private_data, state, bits);
412 static void set_state_bits(struct extent_io_tree *tree,
413 struct extent_state *state, unsigned *bits,
414 struct extent_changeset *changeset);
417 * insert an extent_state struct into the tree. 'bits' are set on the
418 * struct before it is inserted.
420 * This may return -EEXIST if the extent is already there, in which case the
421 * state struct is freed.
423 * The tree lock is not taken internally. This is a utility function and
424 * probably isn't what you want to call (see set/clear_extent_bit).
426 static int insert_state(struct extent_io_tree *tree,
427 struct extent_state *state, u64 start, u64 end,
429 struct rb_node **parent,
430 unsigned *bits, struct extent_changeset *changeset)
432 struct rb_node *node;
435 WARN(1, KERN_ERR "BTRFS: end < start %llu %llu\n",
437 state->start = start;
440 set_state_bits(tree, state, bits, changeset);
442 node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
444 struct extent_state *found;
445 found = rb_entry(node, struct extent_state, rb_node);
446 pr_err("BTRFS: found node %llu %llu on insert of %llu %llu\n",
447 found->start, found->end, start, end);
450 merge_state(tree, state);
454 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
457 if (tree->ops && tree->ops->split_extent_hook)
458 tree->ops->split_extent_hook(tree->private_data, orig, split);
462 * split a given extent state struct in two, inserting the preallocated
463 * struct 'prealloc' as the newly created second half. 'split' indicates an
464 * offset inside 'orig' where it should be split.
467 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
468 * are two extent state structs in the tree:
469 * prealloc: [orig->start, split - 1]
470 * orig: [ split, orig->end ]
472 * The tree locks are not taken by this function. They need to be held
475 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
476 struct extent_state *prealloc, u64 split)
478 struct rb_node *node;
480 split_cb(tree, orig, split);
482 prealloc->start = orig->start;
483 prealloc->end = split - 1;
484 prealloc->state = orig->state;
487 node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
488 &prealloc->rb_node, NULL, NULL);
490 free_extent_state(prealloc);
496 static struct extent_state *next_state(struct extent_state *state)
498 struct rb_node *next = rb_next(&state->rb_node);
500 return rb_entry(next, struct extent_state, rb_node);
506 * utility function to clear some bits in an extent state struct.
507 * it will optionally wake up any one waiting on this state (wake == 1).
509 * If no bits are set on the state struct after clearing things, the
510 * struct is freed and removed from the tree
512 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
513 struct extent_state *state,
514 unsigned *bits, int wake,
515 struct extent_changeset *changeset)
517 struct extent_state *next;
518 unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
521 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
522 u64 range = state->end - state->start + 1;
523 WARN_ON(range > tree->dirty_bytes);
524 tree->dirty_bytes -= range;
526 clear_state_cb(tree, state, bits);
527 ret = add_extent_changeset(state, bits_to_clear, changeset, 0);
529 state->state &= ~bits_to_clear;
532 if (state->state == 0) {
533 next = next_state(state);
534 if (extent_state_in_tree(state)) {
535 rb_erase(&state->rb_node, &tree->state);
536 RB_CLEAR_NODE(&state->rb_node);
537 free_extent_state(state);
542 merge_state(tree, state);
543 next = next_state(state);
548 static struct extent_state *
549 alloc_extent_state_atomic(struct extent_state *prealloc)
552 prealloc = alloc_extent_state(GFP_ATOMIC);
557 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
559 struct inode *inode = tree->private_data;
561 btrfs_panic(btrfs_sb(inode->i_sb), err,
562 "locking error: extent tree was modified by another thread while locked");
566 * clear some bits on a range in the tree. This may require splitting
567 * or inserting elements in the tree, so the gfp mask is used to
568 * indicate which allocations or sleeping are allowed.
570 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
571 * the given range from the tree regardless of state (ie for truncate).
573 * the range [start, end] is inclusive.
575 * This takes the tree lock, and returns 0 on success and < 0 on error.
577 int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
578 unsigned bits, int wake, int delete,
579 struct extent_state **cached_state,
580 gfp_t mask, struct extent_changeset *changeset)
582 struct extent_state *state;
583 struct extent_state *cached;
584 struct extent_state *prealloc = NULL;
585 struct rb_node *node;
590 btrfs_debug_check_extent_io_range(tree, start, end);
592 if (bits & EXTENT_DELALLOC)
593 bits |= EXTENT_NORESERVE;
596 bits |= ~EXTENT_CTLBITS;
597 bits |= EXTENT_FIRST_DELALLOC;
599 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
602 if (!prealloc && gfpflags_allow_blocking(mask)) {
604 * Don't care for allocation failure here because we might end
605 * up not needing the pre-allocated extent state at all, which
606 * is the case if we only have in the tree extent states that
607 * cover our input range and don't cover too any other range.
608 * If we end up needing a new extent state we allocate it later.
610 prealloc = alloc_extent_state(mask);
613 spin_lock(&tree->lock);
615 cached = *cached_state;
618 *cached_state = NULL;
622 if (cached && extent_state_in_tree(cached) &&
623 cached->start <= start && cached->end > start) {
625 refcount_dec(&cached->refs);
630 free_extent_state(cached);
633 * this search will find the extents that end after
636 node = tree_search(tree, start);
639 state = rb_entry(node, struct extent_state, rb_node);
641 if (state->start > end)
643 WARN_ON(state->end < start);
644 last_end = state->end;
646 /* the state doesn't have the wanted bits, go ahead */
647 if (!(state->state & bits)) {
648 state = next_state(state);
653 * | ---- desired range ---- |
655 * | ------------- state -------------- |
657 * We need to split the extent we found, and may flip
658 * bits on second half.
660 * If the extent we found extends past our range, we
661 * just split and search again. It'll get split again
662 * the next time though.
664 * If the extent we found is inside our range, we clear
665 * the desired bit on it.
668 if (state->start < start) {
669 prealloc = alloc_extent_state_atomic(prealloc);
671 err = split_state(tree, state, prealloc, start);
673 extent_io_tree_panic(tree, err);
678 if (state->end <= end) {
679 state = clear_state_bit(tree, state, &bits, wake,
686 * | ---- desired range ---- |
688 * We need to split the extent, and clear the bit
691 if (state->start <= end && state->end > end) {
692 prealloc = alloc_extent_state_atomic(prealloc);
694 err = split_state(tree, state, prealloc, end + 1);
696 extent_io_tree_panic(tree, err);
701 clear_state_bit(tree, prealloc, &bits, wake, changeset);
707 state = clear_state_bit(tree, state, &bits, wake, changeset);
709 if (last_end == (u64)-1)
711 start = last_end + 1;
712 if (start <= end && state && !need_resched())
718 spin_unlock(&tree->lock);
719 if (gfpflags_allow_blocking(mask))
724 spin_unlock(&tree->lock);
726 free_extent_state(prealloc);
732 static void wait_on_state(struct extent_io_tree *tree,
733 struct extent_state *state)
734 __releases(tree->lock)
735 __acquires(tree->lock)
738 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
739 spin_unlock(&tree->lock);
741 spin_lock(&tree->lock);
742 finish_wait(&state->wq, &wait);
746 * waits for one or more bits to clear on a range in the state tree.
747 * The range [start, end] is inclusive.
748 * The tree lock is taken by this function
750 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
753 struct extent_state *state;
754 struct rb_node *node;
756 btrfs_debug_check_extent_io_range(tree, start, end);
758 spin_lock(&tree->lock);
762 * this search will find all the extents that end after
765 node = tree_search(tree, start);
770 state = rb_entry(node, struct extent_state, rb_node);
772 if (state->start > end)
775 if (state->state & bits) {
776 start = state->start;
777 refcount_inc(&state->refs);
778 wait_on_state(tree, state);
779 free_extent_state(state);
782 start = state->end + 1;
787 if (!cond_resched_lock(&tree->lock)) {
788 node = rb_next(node);
793 spin_unlock(&tree->lock);
796 static void set_state_bits(struct extent_io_tree *tree,
797 struct extent_state *state,
798 unsigned *bits, struct extent_changeset *changeset)
800 unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
803 set_state_cb(tree, state, bits);
804 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
805 u64 range = state->end - state->start + 1;
806 tree->dirty_bytes += range;
808 ret = add_extent_changeset(state, bits_to_set, changeset, 1);
810 state->state |= bits_to_set;
813 static void cache_state_if_flags(struct extent_state *state,
814 struct extent_state **cached_ptr,
817 if (cached_ptr && !(*cached_ptr)) {
818 if (!flags || (state->state & flags)) {
820 refcount_inc(&state->refs);
825 static void cache_state(struct extent_state *state,
826 struct extent_state **cached_ptr)
828 return cache_state_if_flags(state, cached_ptr,
829 EXTENT_IOBITS | EXTENT_BOUNDARY);
833 * set some bits on a range in the tree. This may require allocations or
834 * sleeping, so the gfp mask is used to indicate what is allowed.
836 * If any of the exclusive bits are set, this will fail with -EEXIST if some
837 * part of the range already has the desired bits set. The start of the
838 * existing range is returned in failed_start in this case.
840 * [start, end] is inclusive This takes the tree lock.
843 static int __must_check
844 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
845 unsigned bits, unsigned exclusive_bits,
846 u64 *failed_start, struct extent_state **cached_state,
847 gfp_t mask, struct extent_changeset *changeset)
849 struct extent_state *state;
850 struct extent_state *prealloc = NULL;
851 struct rb_node *node;
853 struct rb_node *parent;
858 btrfs_debug_check_extent_io_range(tree, start, end);
860 bits |= EXTENT_FIRST_DELALLOC;
862 if (!prealloc && gfpflags_allow_blocking(mask)) {
864 * Don't care for allocation failure here because we might end
865 * up not needing the pre-allocated extent state at all, which
866 * is the case if we only have in the tree extent states that
867 * cover our input range and don't cover too any other range.
868 * If we end up needing a new extent state we allocate it later.
870 prealloc = alloc_extent_state(mask);
873 spin_lock(&tree->lock);
874 if (cached_state && *cached_state) {
875 state = *cached_state;
876 if (state->start <= start && state->end > start &&
877 extent_state_in_tree(state)) {
878 node = &state->rb_node;
883 * this search will find all the extents that end after
886 node = tree_search_for_insert(tree, start, &p, &parent);
888 prealloc = alloc_extent_state_atomic(prealloc);
890 err = insert_state(tree, prealloc, start, end,
891 &p, &parent, &bits, changeset);
893 extent_io_tree_panic(tree, err);
895 cache_state(prealloc, cached_state);
899 state = rb_entry(node, struct extent_state, rb_node);
901 last_start = state->start;
902 last_end = state->end;
905 * | ---- desired range ---- |
908 * Just lock what we found and keep going
910 if (state->start == start && state->end <= end) {
911 if (state->state & exclusive_bits) {
912 *failed_start = state->start;
917 set_state_bits(tree, state, &bits, changeset);
918 cache_state(state, cached_state);
919 merge_state(tree, state);
920 if (last_end == (u64)-1)
922 start = last_end + 1;
923 state = next_state(state);
924 if (start < end && state && state->start == start &&
931 * | ---- desired range ---- |
934 * | ------------- state -------------- |
936 * We need to split the extent we found, and may flip bits on
939 * If the extent we found extends past our
940 * range, we just split and search again. It'll get split
941 * again the next time though.
943 * If the extent we found is inside our range, we set the
946 if (state->start < start) {
947 if (state->state & exclusive_bits) {
948 *failed_start = start;
953 prealloc = alloc_extent_state_atomic(prealloc);
955 err = split_state(tree, state, prealloc, start);
957 extent_io_tree_panic(tree, err);
962 if (state->end <= end) {
963 set_state_bits(tree, state, &bits, changeset);
964 cache_state(state, cached_state);
965 merge_state(tree, state);
966 if (last_end == (u64)-1)
968 start = last_end + 1;
969 state = next_state(state);
970 if (start < end && state && state->start == start &&
977 * | ---- desired range ---- |
978 * | state | or | state |
980 * There's a hole, we need to insert something in it and
981 * ignore the extent we found.
983 if (state->start > start) {
985 if (end < last_start)
988 this_end = last_start - 1;
990 prealloc = alloc_extent_state_atomic(prealloc);
994 * Avoid to free 'prealloc' if it can be merged with
997 err = insert_state(tree, prealloc, start, this_end,
998 NULL, NULL, &bits, changeset);
1000 extent_io_tree_panic(tree, err);
1002 cache_state(prealloc, cached_state);
1004 start = this_end + 1;
1008 * | ---- desired range ---- |
1010 * We need to split the extent, and set the bit
1013 if (state->start <= end && state->end > end) {
1014 if (state->state & exclusive_bits) {
1015 *failed_start = start;
1020 prealloc = alloc_extent_state_atomic(prealloc);
1022 err = split_state(tree, state, prealloc, end + 1);
1024 extent_io_tree_panic(tree, err);
1026 set_state_bits(tree, prealloc, &bits, changeset);
1027 cache_state(prealloc, cached_state);
1028 merge_state(tree, prealloc);
1036 spin_unlock(&tree->lock);
1037 if (gfpflags_allow_blocking(mask))
1042 spin_unlock(&tree->lock);
1044 free_extent_state(prealloc);
1050 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1051 unsigned bits, u64 * failed_start,
1052 struct extent_state **cached_state, gfp_t mask)
1054 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
1055 cached_state, mask, NULL);
1060 * convert_extent_bit - convert all bits in a given range from one bit to
1062 * @tree: the io tree to search
1063 * @start: the start offset in bytes
1064 * @end: the end offset in bytes (inclusive)
1065 * @bits: the bits to set in this range
1066 * @clear_bits: the bits to clear in this range
1067 * @cached_state: state that we're going to cache
1069 * This will go through and set bits for the given range. If any states exist
1070 * already in this range they are set with the given bit and cleared of the
1071 * clear_bits. This is only meant to be used by things that are mergeable, ie
1072 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1073 * boundary bits like LOCK.
1075 * All allocations are done with GFP_NOFS.
1077 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1078 unsigned bits, unsigned clear_bits,
1079 struct extent_state **cached_state)
1081 struct extent_state *state;
1082 struct extent_state *prealloc = NULL;
1083 struct rb_node *node;
1085 struct rb_node *parent;
1089 bool first_iteration = true;
1091 btrfs_debug_check_extent_io_range(tree, start, end);
1096 * Best effort, don't worry if extent state allocation fails
1097 * here for the first iteration. We might have a cached state
1098 * that matches exactly the target range, in which case no
1099 * extent state allocations are needed. We'll only know this
1100 * after locking the tree.
1102 prealloc = alloc_extent_state(GFP_NOFS);
1103 if (!prealloc && !first_iteration)
1107 spin_lock(&tree->lock);
1108 if (cached_state && *cached_state) {
1109 state = *cached_state;
1110 if (state->start <= start && state->end > start &&
1111 extent_state_in_tree(state)) {
1112 node = &state->rb_node;
1118 * this search will find all the extents that end after
1121 node = tree_search_for_insert(tree, start, &p, &parent);
1123 prealloc = alloc_extent_state_atomic(prealloc);
1128 err = insert_state(tree, prealloc, start, end,
1129 &p, &parent, &bits, NULL);
1131 extent_io_tree_panic(tree, err);
1132 cache_state(prealloc, cached_state);
1136 state = rb_entry(node, struct extent_state, rb_node);
1138 last_start = state->start;
1139 last_end = state->end;
1142 * | ---- desired range ---- |
1145 * Just lock what we found and keep going
1147 if (state->start == start && state->end <= end) {
1148 set_state_bits(tree, state, &bits, NULL);
1149 cache_state(state, cached_state);
1150 state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
1151 if (last_end == (u64)-1)
1153 start = last_end + 1;
1154 if (start < end && state && state->start == start &&
1161 * | ---- desired range ---- |
1164 * | ------------- state -------------- |
1166 * We need to split the extent we found, and may flip bits on
1169 * If the extent we found extends past our
1170 * range, we just split and search again. It'll get split
1171 * again the next time though.
1173 * If the extent we found is inside our range, we set the
1174 * desired bit on it.
1176 if (state->start < start) {
1177 prealloc = alloc_extent_state_atomic(prealloc);
1182 err = split_state(tree, state, prealloc, start);
1184 extent_io_tree_panic(tree, err);
1188 if (state->end <= end) {
1189 set_state_bits(tree, state, &bits, NULL);
1190 cache_state(state, cached_state);
1191 state = clear_state_bit(tree, state, &clear_bits, 0,
1193 if (last_end == (u64)-1)
1195 start = last_end + 1;
1196 if (start < end && state && state->start == start &&
1203 * | ---- desired range ---- |
1204 * | state | or | state |
1206 * There's a hole, we need to insert something in it and
1207 * ignore the extent we found.
1209 if (state->start > start) {
1211 if (end < last_start)
1214 this_end = last_start - 1;
1216 prealloc = alloc_extent_state_atomic(prealloc);
1223 * Avoid to free 'prealloc' if it can be merged with
1226 err = insert_state(tree, prealloc, start, this_end,
1227 NULL, NULL, &bits, NULL);
1229 extent_io_tree_panic(tree, err);
1230 cache_state(prealloc, cached_state);
1232 start = this_end + 1;
1236 * | ---- desired range ---- |
1238 * We need to split the extent, and set the bit
1241 if (state->start <= end && state->end > end) {
1242 prealloc = alloc_extent_state_atomic(prealloc);
1248 err = split_state(tree, state, prealloc, end + 1);
1250 extent_io_tree_panic(tree, err);
1252 set_state_bits(tree, prealloc, &bits, NULL);
1253 cache_state(prealloc, cached_state);
1254 clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
1262 spin_unlock(&tree->lock);
1264 first_iteration = false;
1268 spin_unlock(&tree->lock);
1270 free_extent_state(prealloc);
1275 /* wrappers around set/clear extent bit */
1276 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1277 unsigned bits, struct extent_changeset *changeset)
1280 * We don't support EXTENT_LOCKED yet, as current changeset will
1281 * record any bits changed, so for EXTENT_LOCKED case, it will
1282 * either fail with -EEXIST or changeset will record the whole
1285 BUG_ON(bits & EXTENT_LOCKED);
1287 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
1291 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1292 unsigned bits, int wake, int delete,
1293 struct extent_state **cached)
1295 return __clear_extent_bit(tree, start, end, bits, wake, delete,
1296 cached, GFP_NOFS, NULL);
1299 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1300 unsigned bits, struct extent_changeset *changeset)
1303 * Don't support EXTENT_LOCKED case, same reason as
1304 * set_record_extent_bits().
1306 BUG_ON(bits & EXTENT_LOCKED);
1308 return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
1313 * either insert or lock state struct between start and end use mask to tell
1314 * us if waiting is desired.
1316 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1317 struct extent_state **cached_state)
1323 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
1324 EXTENT_LOCKED, &failed_start,
1325 cached_state, GFP_NOFS, NULL);
1326 if (err == -EEXIST) {
1327 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1328 start = failed_start;
1331 WARN_ON(start > end);
1336 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1341 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1342 &failed_start, NULL, GFP_NOFS, NULL);
1343 if (err == -EEXIST) {
1344 if (failed_start > start)
1345 clear_extent_bit(tree, start, failed_start - 1,
1346 EXTENT_LOCKED, 1, 0, NULL);
1352 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1354 unsigned long index = start >> PAGE_SHIFT;
1355 unsigned long end_index = end >> PAGE_SHIFT;
1358 while (index <= end_index) {
1359 page = find_get_page(inode->i_mapping, index);
1360 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1361 clear_page_dirty_for_io(page);
1367 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1369 unsigned long index = start >> PAGE_SHIFT;
1370 unsigned long end_index = end >> PAGE_SHIFT;
1373 while (index <= end_index) {
1374 page = find_get_page(inode->i_mapping, index);
1375 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1376 __set_page_dirty_nobuffers(page);
1377 account_page_redirty(page);
1383 /* find the first state struct with 'bits' set after 'start', and
1384 * return it. tree->lock must be held. NULL will returned if
1385 * nothing was found after 'start'
1387 static struct extent_state *
1388 find_first_extent_bit_state(struct extent_io_tree *tree,
1389 u64 start, unsigned bits)
1391 struct rb_node *node;
1392 struct extent_state *state;
1395 * this search will find all the extents that end after
1398 node = tree_search(tree, start);
1403 state = rb_entry(node, struct extent_state, rb_node);
1404 if (state->end >= start && (state->state & bits))
1407 node = rb_next(node);
1416 * find the first offset in the io tree with 'bits' set. zero is
1417 * returned if we find something, and *start_ret and *end_ret are
1418 * set to reflect the state struct that was found.
1420 * If nothing was found, 1 is returned. If found something, return 0.
1422 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1423 u64 *start_ret, u64 *end_ret, unsigned bits,
1424 struct extent_state **cached_state)
1426 struct extent_state *state;
1430 spin_lock(&tree->lock);
1431 if (cached_state && *cached_state) {
1432 state = *cached_state;
1433 if (state->end == start - 1 && extent_state_in_tree(state)) {
1434 n = rb_next(&state->rb_node);
1436 state = rb_entry(n, struct extent_state,
1438 if (state->state & bits)
1442 free_extent_state(*cached_state);
1443 *cached_state = NULL;
1446 free_extent_state(*cached_state);
1447 *cached_state = NULL;
1450 state = find_first_extent_bit_state(tree, start, bits);
1453 cache_state_if_flags(state, cached_state, 0);
1454 *start_ret = state->start;
1455 *end_ret = state->end;
1459 spin_unlock(&tree->lock);
1464 * find a contiguous range of bytes in the file marked as delalloc, not
1465 * more than 'max_bytes'. start and end are used to return the range,
1467 * 1 is returned if we find something, 0 if nothing was in the tree
1469 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1470 u64 *start, u64 *end, u64 max_bytes,
1471 struct extent_state **cached_state)
1473 struct rb_node *node;
1474 struct extent_state *state;
1475 u64 cur_start = *start;
1477 u64 total_bytes = 0;
1479 spin_lock(&tree->lock);
1482 * this search will find all the extents that end after
1485 node = tree_search(tree, cur_start);
1493 state = rb_entry(node, struct extent_state, rb_node);
1494 if (found && (state->start != cur_start ||
1495 (state->state & EXTENT_BOUNDARY))) {
1498 if (!(state->state & EXTENT_DELALLOC)) {
1504 *start = state->start;
1505 *cached_state = state;
1506 refcount_inc(&state->refs);
1510 cur_start = state->end + 1;
1511 node = rb_next(node);
1512 total_bytes += state->end - state->start + 1;
1513 if (total_bytes >= max_bytes)
1519 spin_unlock(&tree->lock);
1523 static int __process_pages_contig(struct address_space *mapping,
1524 struct page *locked_page,
1525 pgoff_t start_index, pgoff_t end_index,
1526 unsigned long page_ops, pgoff_t *index_ret);
1528 static noinline void __unlock_for_delalloc(struct inode *inode,
1529 struct page *locked_page,
1532 unsigned long index = start >> PAGE_SHIFT;
1533 unsigned long end_index = end >> PAGE_SHIFT;
1535 ASSERT(locked_page);
1536 if (index == locked_page->index && end_index == index)
1539 __process_pages_contig(inode->i_mapping, locked_page, index, end_index,
1543 static noinline int lock_delalloc_pages(struct inode *inode,
1544 struct page *locked_page,
1548 unsigned long index = delalloc_start >> PAGE_SHIFT;
1549 unsigned long index_ret = index;
1550 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1553 ASSERT(locked_page);
1554 if (index == locked_page->index && index == end_index)
1557 ret = __process_pages_contig(inode->i_mapping, locked_page, index,
1558 end_index, PAGE_LOCK, &index_ret);
1560 __unlock_for_delalloc(inode, locked_page, delalloc_start,
1561 (u64)index_ret << PAGE_SHIFT);
1566 * find a contiguous range of bytes in the file marked as delalloc, not
1567 * more than 'max_bytes'. start and end are used to return the range,
1569 * 1 is returned if we find something, 0 if nothing was in the tree
1571 STATIC u64 find_lock_delalloc_range(struct inode *inode,
1572 struct extent_io_tree *tree,
1573 struct page *locked_page, u64 *start,
1574 u64 *end, u64 max_bytes)
1579 struct extent_state *cached_state = NULL;
1584 /* step one, find a bunch of delalloc bytes starting at start */
1585 delalloc_start = *start;
1587 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1588 max_bytes, &cached_state);
1589 if (!found || delalloc_end <= *start) {
1590 *start = delalloc_start;
1591 *end = delalloc_end;
1592 free_extent_state(cached_state);
1597 * start comes from the offset of locked_page. We have to lock
1598 * pages in order, so we can't process delalloc bytes before
1601 if (delalloc_start < *start)
1602 delalloc_start = *start;
1605 * make sure to limit the number of pages we try to lock down
1607 if (delalloc_end + 1 - delalloc_start > max_bytes)
1608 delalloc_end = delalloc_start + max_bytes - 1;
1610 /* step two, lock all the pages after the page that has start */
1611 ret = lock_delalloc_pages(inode, locked_page,
1612 delalloc_start, delalloc_end);
1613 if (ret == -EAGAIN) {
1614 /* some of the pages are gone, lets avoid looping by
1615 * shortening the size of the delalloc range we're searching
1617 free_extent_state(cached_state);
1618 cached_state = NULL;
1620 max_bytes = PAGE_SIZE;
1628 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1630 /* step three, lock the state bits for the whole range */
1631 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1633 /* then test to make sure it is all still delalloc */
1634 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1635 EXTENT_DELALLOC, 1, cached_state);
1637 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1639 __unlock_for_delalloc(inode, locked_page,
1640 delalloc_start, delalloc_end);
1644 free_extent_state(cached_state);
1645 *start = delalloc_start;
1646 *end = delalloc_end;
1651 static int __process_pages_contig(struct address_space *mapping,
1652 struct page *locked_page,
1653 pgoff_t start_index, pgoff_t end_index,
1654 unsigned long page_ops, pgoff_t *index_ret)
1656 unsigned long nr_pages = end_index - start_index + 1;
1657 unsigned long pages_locked = 0;
1658 pgoff_t index = start_index;
1659 struct page *pages[16];
1664 if (page_ops & PAGE_LOCK) {
1665 ASSERT(page_ops == PAGE_LOCK);
1666 ASSERT(index_ret && *index_ret == start_index);
1669 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1670 mapping_set_error(mapping, -EIO);
1672 while (nr_pages > 0) {
1673 ret = find_get_pages_contig(mapping, index,
1674 min_t(unsigned long,
1675 nr_pages, ARRAY_SIZE(pages)), pages);
1678 * Only if we're going to lock these pages,
1679 * can we find nothing at @index.
1681 ASSERT(page_ops & PAGE_LOCK);
1686 for (i = 0; i < ret; i++) {
1687 if (page_ops & PAGE_SET_PRIVATE2)
1688 SetPagePrivate2(pages[i]);
1690 if (pages[i] == locked_page) {
1695 if (page_ops & PAGE_CLEAR_DIRTY)
1696 clear_page_dirty_for_io(pages[i]);
1697 if (page_ops & PAGE_SET_WRITEBACK)
1698 set_page_writeback(pages[i]);
1699 if (page_ops & PAGE_SET_ERROR)
1700 SetPageError(pages[i]);
1701 if (page_ops & PAGE_END_WRITEBACK)
1702 end_page_writeback(pages[i]);
1703 if (page_ops & PAGE_UNLOCK)
1704 unlock_page(pages[i]);
1705 if (page_ops & PAGE_LOCK) {
1706 lock_page(pages[i]);
1707 if (!PageDirty(pages[i]) ||
1708 pages[i]->mapping != mapping) {
1709 unlock_page(pages[i]);
1723 if (err && index_ret)
1724 *index_ret = start_index + pages_locked - 1;
1728 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1729 u64 delalloc_end, struct page *locked_page,
1730 unsigned clear_bits,
1731 unsigned long page_ops)
1733 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0,
1736 __process_pages_contig(inode->i_mapping, locked_page,
1737 start >> PAGE_SHIFT, end >> PAGE_SHIFT,
1742 * count the number of bytes in the tree that have a given bit(s)
1743 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1744 * cached. The total number found is returned.
1746 u64 count_range_bits(struct extent_io_tree *tree,
1747 u64 *start, u64 search_end, u64 max_bytes,
1748 unsigned bits, int contig)
1750 struct rb_node *node;
1751 struct extent_state *state;
1752 u64 cur_start = *start;
1753 u64 total_bytes = 0;
1757 if (WARN_ON(search_end <= cur_start))
1760 spin_lock(&tree->lock);
1761 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1762 total_bytes = tree->dirty_bytes;
1766 * this search will find all the extents that end after
1769 node = tree_search(tree, cur_start);
1774 state = rb_entry(node, struct extent_state, rb_node);
1775 if (state->start > search_end)
1777 if (contig && found && state->start > last + 1)
1779 if (state->end >= cur_start && (state->state & bits) == bits) {
1780 total_bytes += min(search_end, state->end) + 1 -
1781 max(cur_start, state->start);
1782 if (total_bytes >= max_bytes)
1785 *start = max(cur_start, state->start);
1789 } else if (contig && found) {
1792 node = rb_next(node);
1797 spin_unlock(&tree->lock);
1802 * set the private field for a given byte offset in the tree. If there isn't
1803 * an extent_state there already, this does nothing.
1805 static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start,
1806 struct io_failure_record *failrec)
1808 struct rb_node *node;
1809 struct extent_state *state;
1812 spin_lock(&tree->lock);
1814 * this search will find all the extents that end after
1817 node = tree_search(tree, start);
1822 state = rb_entry(node, struct extent_state, rb_node);
1823 if (state->start != start) {
1827 state->failrec = failrec;
1829 spin_unlock(&tree->lock);
1833 static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start,
1834 struct io_failure_record **failrec)
1836 struct rb_node *node;
1837 struct extent_state *state;
1840 spin_lock(&tree->lock);
1842 * this search will find all the extents that end after
1845 node = tree_search(tree, start);
1850 state = rb_entry(node, struct extent_state, rb_node);
1851 if (state->start != start) {
1855 *failrec = state->failrec;
1857 spin_unlock(&tree->lock);
1862 * searches a range in the state tree for a given mask.
1863 * If 'filled' == 1, this returns 1 only if every extent in the tree
1864 * has the bits set. Otherwise, 1 is returned if any bit in the
1865 * range is found set.
1867 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1868 unsigned bits, int filled, struct extent_state *cached)
1870 struct extent_state *state = NULL;
1871 struct rb_node *node;
1874 spin_lock(&tree->lock);
1875 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
1876 cached->end > start)
1877 node = &cached->rb_node;
1879 node = tree_search(tree, start);
1880 while (node && start <= end) {
1881 state = rb_entry(node, struct extent_state, rb_node);
1883 if (filled && state->start > start) {
1888 if (state->start > end)
1891 if (state->state & bits) {
1895 } else if (filled) {
1900 if (state->end == (u64)-1)
1903 start = state->end + 1;
1906 node = rb_next(node);
1913 spin_unlock(&tree->lock);
1918 * helper function to set a given page up to date if all the
1919 * extents in the tree for that page are up to date
1921 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1923 u64 start = page_offset(page);
1924 u64 end = start + PAGE_SIZE - 1;
1925 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1926 SetPageUptodate(page);
1929 int free_io_failure(struct extent_io_tree *failure_tree,
1930 struct extent_io_tree *io_tree,
1931 struct io_failure_record *rec)
1936 set_state_failrec(failure_tree, rec->start, NULL);
1937 ret = clear_extent_bits(failure_tree, rec->start,
1938 rec->start + rec->len - 1,
1939 EXTENT_LOCKED | EXTENT_DIRTY);
1943 ret = clear_extent_bits(io_tree, rec->start,
1944 rec->start + rec->len - 1,
1954 * this bypasses the standard btrfs submit functions deliberately, as
1955 * the standard behavior is to write all copies in a raid setup. here we only
1956 * want to write the one bad copy. so we do the mapping for ourselves and issue
1957 * submit_bio directly.
1958 * to avoid any synchronization issues, wait for the data after writing, which
1959 * actually prevents the read that triggered the error from finishing.
1960 * currently, there can be no more than two copies of every data bit. thus,
1961 * exactly one rewrite is required.
1963 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
1964 u64 length, u64 logical, struct page *page,
1965 unsigned int pg_offset, int mirror_num)
1968 struct btrfs_device *dev;
1971 struct btrfs_bio *bbio = NULL;
1974 ASSERT(!(fs_info->sb->s_flags & SB_RDONLY));
1975 BUG_ON(!mirror_num);
1977 bio = btrfs_io_bio_alloc(1);
1978 bio->bi_iter.bi_size = 0;
1979 map_length = length;
1982 * Avoid races with device replace and make sure our bbio has devices
1983 * associated to its stripes that don't go away while we are doing the
1984 * read repair operation.
1986 btrfs_bio_counter_inc_blocked(fs_info);
1987 if (btrfs_is_parity_mirror(fs_info, logical, length)) {
1989 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
1990 * to update all raid stripes, but here we just want to correct
1991 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
1992 * stripe's dev and sector.
1994 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical,
1995 &map_length, &bbio, 0);
1997 btrfs_bio_counter_dec(fs_info);
2001 ASSERT(bbio->mirror_num == 1);
2003 ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
2004 &map_length, &bbio, mirror_num);
2006 btrfs_bio_counter_dec(fs_info);
2010 BUG_ON(mirror_num != bbio->mirror_num);
2013 sector = bbio->stripes[bbio->mirror_num - 1].physical >> 9;
2014 bio->bi_iter.bi_sector = sector;
2015 dev = bbio->stripes[bbio->mirror_num - 1].dev;
2016 btrfs_put_bbio(bbio);
2017 if (!dev || !dev->bdev ||
2018 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
2019 btrfs_bio_counter_dec(fs_info);
2023 bio_set_dev(bio, dev->bdev);
2024 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
2025 bio_add_page(bio, page, length, pg_offset);
2027 if (btrfsic_submit_bio_wait(bio)) {
2028 /* try to remap that extent elsewhere? */
2029 btrfs_bio_counter_dec(fs_info);
2031 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2035 btrfs_info_rl_in_rcu(fs_info,
2036 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2038 rcu_str_deref(dev->name), sector);
2039 btrfs_bio_counter_dec(fs_info);
2044 int repair_eb_io_failure(struct btrfs_fs_info *fs_info,
2045 struct extent_buffer *eb, int mirror_num)
2047 u64 start = eb->start;
2048 int i, num_pages = num_extent_pages(eb);
2051 if (sb_rdonly(fs_info->sb))
2054 for (i = 0; i < num_pages; i++) {
2055 struct page *p = eb->pages[i];
2057 ret = repair_io_failure(fs_info, 0, start, PAGE_SIZE, start, p,
2058 start - page_offset(p), mirror_num);
2068 * each time an IO finishes, we do a fast check in the IO failure tree
2069 * to see if we need to process or clean up an io_failure_record
2071 int clean_io_failure(struct btrfs_fs_info *fs_info,
2072 struct extent_io_tree *failure_tree,
2073 struct extent_io_tree *io_tree, u64 start,
2074 struct page *page, u64 ino, unsigned int pg_offset)
2077 struct io_failure_record *failrec;
2078 struct extent_state *state;
2083 ret = count_range_bits(failure_tree, &private, (u64)-1, 1,
2088 ret = get_state_failrec(failure_tree, start, &failrec);
2092 BUG_ON(!failrec->this_mirror);
2094 if (failrec->in_validation) {
2095 /* there was no real error, just free the record */
2096 btrfs_debug(fs_info,
2097 "clean_io_failure: freeing dummy error at %llu",
2101 if (sb_rdonly(fs_info->sb))
2104 spin_lock(&io_tree->lock);
2105 state = find_first_extent_bit_state(io_tree,
2108 spin_unlock(&io_tree->lock);
2110 if (state && state->start <= failrec->start &&
2111 state->end >= failrec->start + failrec->len - 1) {
2112 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2114 if (num_copies > 1) {
2115 repair_io_failure(fs_info, ino, start, failrec->len,
2116 failrec->logical, page, pg_offset,
2117 failrec->failed_mirror);
2122 free_io_failure(failure_tree, io_tree, failrec);
2128 * Can be called when
2129 * - hold extent lock
2130 * - under ordered extent
2131 * - the inode is freeing
2133 void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end)
2135 struct extent_io_tree *failure_tree = &inode->io_failure_tree;
2136 struct io_failure_record *failrec;
2137 struct extent_state *state, *next;
2139 if (RB_EMPTY_ROOT(&failure_tree->state))
2142 spin_lock(&failure_tree->lock);
2143 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2145 if (state->start > end)
2148 ASSERT(state->end <= end);
2150 next = next_state(state);
2152 failrec = state->failrec;
2153 free_extent_state(state);
2158 spin_unlock(&failure_tree->lock);
2161 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2162 struct io_failure_record **failrec_ret)
2164 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2165 struct io_failure_record *failrec;
2166 struct extent_map *em;
2167 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2168 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2169 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2173 ret = get_state_failrec(failure_tree, start, &failrec);
2175 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2179 failrec->start = start;
2180 failrec->len = end - start + 1;
2181 failrec->this_mirror = 0;
2182 failrec->bio_flags = 0;
2183 failrec->in_validation = 0;
2185 read_lock(&em_tree->lock);
2186 em = lookup_extent_mapping(em_tree, start, failrec->len);
2188 read_unlock(&em_tree->lock);
2193 if (em->start > start || em->start + em->len <= start) {
2194 free_extent_map(em);
2197 read_unlock(&em_tree->lock);
2203 logical = start - em->start;
2204 logical = em->block_start + logical;
2205 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2206 logical = em->block_start;
2207 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2208 extent_set_compress_type(&failrec->bio_flags,
2212 btrfs_debug(fs_info,
2213 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2214 logical, start, failrec->len);
2216 failrec->logical = logical;
2217 free_extent_map(em);
2219 /* set the bits in the private failure tree */
2220 ret = set_extent_bits(failure_tree, start, end,
2221 EXTENT_LOCKED | EXTENT_DIRTY);
2223 ret = set_state_failrec(failure_tree, start, failrec);
2224 /* set the bits in the inode's tree */
2226 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2232 btrfs_debug(fs_info,
2233 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2234 failrec->logical, failrec->start, failrec->len,
2235 failrec->in_validation);
2237 * when data can be on disk more than twice, add to failrec here
2238 * (e.g. with a list for failed_mirror) to make
2239 * clean_io_failure() clean all those errors at once.
2243 *failrec_ret = failrec;
2248 bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages,
2249 struct io_failure_record *failrec, int failed_mirror)
2251 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2254 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
2255 if (num_copies == 1) {
2257 * we only have a single copy of the data, so don't bother with
2258 * all the retry and error correction code that follows. no
2259 * matter what the error is, it is very likely to persist.
2261 btrfs_debug(fs_info,
2262 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2263 num_copies, failrec->this_mirror, failed_mirror);
2268 * there are two premises:
2269 * a) deliver good data to the caller
2270 * b) correct the bad sectors on disk
2272 if (failed_bio_pages > 1) {
2274 * to fulfill b), we need to know the exact failing sectors, as
2275 * we don't want to rewrite any more than the failed ones. thus,
2276 * we need separate read requests for the failed bio
2278 * if the following BUG_ON triggers, our validation request got
2279 * merged. we need separate requests for our algorithm to work.
2281 BUG_ON(failrec->in_validation);
2282 failrec->in_validation = 1;
2283 failrec->this_mirror = failed_mirror;
2286 * we're ready to fulfill a) and b) alongside. get a good copy
2287 * of the failed sector and if we succeed, we have setup
2288 * everything for repair_io_failure to do the rest for us.
2290 if (failrec->in_validation) {
2291 BUG_ON(failrec->this_mirror != failed_mirror);
2292 failrec->in_validation = 0;
2293 failrec->this_mirror = 0;
2295 failrec->failed_mirror = failed_mirror;
2296 failrec->this_mirror++;
2297 if (failrec->this_mirror == failed_mirror)
2298 failrec->this_mirror++;
2301 if (failrec->this_mirror > num_copies) {
2302 btrfs_debug(fs_info,
2303 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2304 num_copies, failrec->this_mirror, failed_mirror);
2312 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
2313 struct io_failure_record *failrec,
2314 struct page *page, int pg_offset, int icsum,
2315 bio_end_io_t *endio_func, void *data)
2317 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2319 struct btrfs_io_bio *btrfs_failed_bio;
2320 struct btrfs_io_bio *btrfs_bio;
2322 bio = btrfs_io_bio_alloc(1);
2323 bio->bi_end_io = endio_func;
2324 bio->bi_iter.bi_sector = failrec->logical >> 9;
2325 bio_set_dev(bio, fs_info->fs_devices->latest_bdev);
2326 bio->bi_iter.bi_size = 0;
2327 bio->bi_private = data;
2329 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2330 if (btrfs_failed_bio->csum) {
2331 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2333 btrfs_bio = btrfs_io_bio(bio);
2334 btrfs_bio->csum = btrfs_bio->csum_inline;
2336 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
2340 bio_add_page(bio, page, failrec->len, pg_offset);
2346 * this is a generic handler for readpage errors (default
2347 * readpage_io_failed_hook). if other copies exist, read those and write back
2348 * good data to the failed position. does not investigate in remapping the
2349 * failed extent elsewhere, hoping the device will be smart enough to do this as
2353 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2354 struct page *page, u64 start, u64 end,
2357 struct io_failure_record *failrec;
2358 struct inode *inode = page->mapping->host;
2359 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2360 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2363 blk_status_t status;
2365 unsigned failed_bio_pages = bio_pages_all(failed_bio);
2367 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2369 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2373 if (!btrfs_check_repairable(inode, failed_bio_pages, failrec,
2375 free_io_failure(failure_tree, tree, failrec);
2379 if (failed_bio_pages > 1)
2380 read_mode |= REQ_FAILFAST_DEV;
2382 phy_offset >>= inode->i_sb->s_blocksize_bits;
2383 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
2384 start - page_offset(page),
2385 (int)phy_offset, failed_bio->bi_end_io,
2387 bio->bi_opf = REQ_OP_READ | read_mode;
2389 btrfs_debug(btrfs_sb(inode->i_sb),
2390 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2391 read_mode, failrec->this_mirror, failrec->in_validation);
2393 status = tree->ops->submit_bio_hook(tree->private_data, bio, failrec->this_mirror,
2394 failrec->bio_flags, 0);
2396 free_io_failure(failure_tree, tree, failrec);
2398 ret = blk_status_to_errno(status);
2404 /* lots and lots of room for performance fixes in the end_bio funcs */
2406 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2408 int uptodate = (err == 0);
2409 struct extent_io_tree *tree;
2412 tree = &BTRFS_I(page->mapping->host)->io_tree;
2414 if (tree->ops && tree->ops->writepage_end_io_hook)
2415 tree->ops->writepage_end_io_hook(page, start, end, NULL,
2419 ClearPageUptodate(page);
2421 ret = err < 0 ? err : -EIO;
2422 mapping_set_error(page->mapping, ret);
2427 * after a writepage IO is done, we need to:
2428 * clear the uptodate bits on error
2429 * clear the writeback bits in the extent tree for this IO
2430 * end_page_writeback if the page has no more pending IO
2432 * Scheduling is not allowed, so the extent state tree is expected
2433 * to have one and only one object corresponding to this IO.
2435 static void end_bio_extent_writepage(struct bio *bio)
2437 int error = blk_status_to_errno(bio->bi_status);
2438 struct bio_vec *bvec;
2443 ASSERT(!bio_flagged(bio, BIO_CLONED));
2444 bio_for_each_segment_all(bvec, bio, i) {
2445 struct page *page = bvec->bv_page;
2446 struct inode *inode = page->mapping->host;
2447 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2449 /* We always issue full-page reads, but if some block
2450 * in a page fails to read, blk_update_request() will
2451 * advance bv_offset and adjust bv_len to compensate.
2452 * Print a warning for nonzero offsets, and an error
2453 * if they don't add up to a full page. */
2454 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2455 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2457 "partial page write in btrfs with offset %u and length %u",
2458 bvec->bv_offset, bvec->bv_len);
2461 "incomplete page write in btrfs with offset %u and length %u",
2462 bvec->bv_offset, bvec->bv_len);
2465 start = page_offset(page);
2466 end = start + bvec->bv_offset + bvec->bv_len - 1;
2468 end_extent_writepage(page, error, start, end);
2469 end_page_writeback(page);
2476 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2479 struct extent_state *cached = NULL;
2480 u64 end = start + len - 1;
2482 if (uptodate && tree->track_uptodate)
2483 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2484 unlock_extent_cached_atomic(tree, start, end, &cached);
2488 * after a readpage IO is done, we need to:
2489 * clear the uptodate bits on error
2490 * set the uptodate bits if things worked
2491 * set the page up to date if all extents in the tree are uptodate
2492 * clear the lock bit in the extent tree
2493 * unlock the page if there are no other extents locked for it
2495 * Scheduling is not allowed, so the extent state tree is expected
2496 * to have one and only one object corresponding to this IO.
2498 static void end_bio_extent_readpage(struct bio *bio)
2500 struct bio_vec *bvec;
2501 int uptodate = !bio->bi_status;
2502 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2503 struct extent_io_tree *tree, *failure_tree;
2508 u64 extent_start = 0;
2514 ASSERT(!bio_flagged(bio, BIO_CLONED));
2515 bio_for_each_segment_all(bvec, bio, i) {
2516 struct page *page = bvec->bv_page;
2517 struct inode *inode = page->mapping->host;
2518 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2520 btrfs_debug(fs_info,
2521 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2522 (u64)bio->bi_iter.bi_sector, bio->bi_status,
2523 io_bio->mirror_num);
2524 tree = &BTRFS_I(inode)->io_tree;
2525 failure_tree = &BTRFS_I(inode)->io_failure_tree;
2527 /* We always issue full-page reads, but if some block
2528 * in a page fails to read, blk_update_request() will
2529 * advance bv_offset and adjust bv_len to compensate.
2530 * Print a warning for nonzero offsets, and an error
2531 * if they don't add up to a full page. */
2532 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2533 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2535 "partial page read in btrfs with offset %u and length %u",
2536 bvec->bv_offset, bvec->bv_len);
2539 "incomplete page read in btrfs with offset %u and length %u",
2540 bvec->bv_offset, bvec->bv_len);
2543 start = page_offset(page);
2544 end = start + bvec->bv_offset + bvec->bv_len - 1;
2547 mirror = io_bio->mirror_num;
2548 if (likely(uptodate && tree->ops)) {
2549 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2555 clean_io_failure(BTRFS_I(inode)->root->fs_info,
2556 failure_tree, tree, start,
2558 btrfs_ino(BTRFS_I(inode)), 0);
2561 if (likely(uptodate))
2565 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2566 if (ret == -EAGAIN) {
2568 * Data inode's readpage_io_failed_hook() always
2571 * The generic bio_readpage_error handles errors
2572 * the following way: If possible, new read
2573 * requests are created and submitted and will
2574 * end up in end_bio_extent_readpage as well (if
2575 * we're lucky, not in the !uptodate case). In
2576 * that case it returns 0 and we just go on with
2577 * the next page in our bio. If it can't handle
2578 * the error it will return -EIO and we remain
2579 * responsible for that page.
2581 ret = bio_readpage_error(bio, offset, page,
2582 start, end, mirror);
2584 uptodate = !bio->bi_status;
2591 * metadata's readpage_io_failed_hook() always returns
2592 * -EIO and fixes nothing. -EIO is also returned if
2593 * data inode error could not be fixed.
2595 ASSERT(ret == -EIO);
2598 if (likely(uptodate)) {
2599 loff_t i_size = i_size_read(inode);
2600 pgoff_t end_index = i_size >> PAGE_SHIFT;
2603 /* Zero out the end if this page straddles i_size */
2604 off = i_size & (PAGE_SIZE-1);
2605 if (page->index == end_index && off)
2606 zero_user_segment(page, off, PAGE_SIZE);
2607 SetPageUptodate(page);
2609 ClearPageUptodate(page);
2615 if (unlikely(!uptodate)) {
2617 endio_readpage_release_extent(tree,
2623 endio_readpage_release_extent(tree, start,
2624 end - start + 1, 0);
2625 } else if (!extent_len) {
2626 extent_start = start;
2627 extent_len = end + 1 - start;
2628 } else if (extent_start + extent_len == start) {
2629 extent_len += end + 1 - start;
2631 endio_readpage_release_extent(tree, extent_start,
2632 extent_len, uptodate);
2633 extent_start = start;
2634 extent_len = end + 1 - start;
2639 endio_readpage_release_extent(tree, extent_start, extent_len,
2642 io_bio->end_io(io_bio, blk_status_to_errno(bio->bi_status));
2647 * Initialize the members up to but not including 'bio'. Use after allocating a
2648 * new bio by bio_alloc_bioset as it does not initialize the bytes outside of
2649 * 'bio' because use of __GFP_ZERO is not supported.
2651 static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio)
2653 memset(btrfs_bio, 0, offsetof(struct btrfs_io_bio, bio));
2657 * The following helpers allocate a bio. As it's backed by a bioset, it'll
2658 * never fail. We're returning a bio right now but you can call btrfs_io_bio
2659 * for the appropriate container_of magic
2661 struct bio *btrfs_bio_alloc(struct block_device *bdev, u64 first_byte)
2665 bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, &btrfs_bioset);
2666 bio_set_dev(bio, bdev);
2667 bio->bi_iter.bi_sector = first_byte >> 9;
2668 btrfs_io_bio_init(btrfs_io_bio(bio));
2672 struct bio *btrfs_bio_clone(struct bio *bio)
2674 struct btrfs_io_bio *btrfs_bio;
2677 /* Bio allocation backed by a bioset does not fail */
2678 new = bio_clone_fast(bio, GFP_NOFS, &btrfs_bioset);
2679 btrfs_bio = btrfs_io_bio(new);
2680 btrfs_io_bio_init(btrfs_bio);
2681 btrfs_bio->iter = bio->bi_iter;
2685 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs)
2689 /* Bio allocation backed by a bioset does not fail */
2690 bio = bio_alloc_bioset(GFP_NOFS, nr_iovecs, &btrfs_bioset);
2691 btrfs_io_bio_init(btrfs_io_bio(bio));
2695 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
2698 struct btrfs_io_bio *btrfs_bio;
2700 /* this will never fail when it's backed by a bioset */
2701 bio = bio_clone_fast(orig, GFP_NOFS, &btrfs_bioset);
2704 btrfs_bio = btrfs_io_bio(bio);
2705 btrfs_io_bio_init(btrfs_bio);
2707 bio_trim(bio, offset >> 9, size >> 9);
2708 btrfs_bio->iter = bio->bi_iter;
2712 static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
2713 unsigned long bio_flags)
2715 blk_status_t ret = 0;
2716 struct bio_vec *bvec = bio_last_bvec_all(bio);
2717 struct page *page = bvec->bv_page;
2718 struct extent_io_tree *tree = bio->bi_private;
2721 start = page_offset(page) + bvec->bv_offset;
2723 bio->bi_private = NULL;
2726 ret = tree->ops->submit_bio_hook(tree->private_data, bio,
2727 mirror_num, bio_flags, start);
2729 btrfsic_submit_bio(bio);
2731 return blk_status_to_errno(ret);
2735 * @opf: bio REQ_OP_* and REQ_* flags as one value
2736 * @tree: tree so we can call our merge_bio hook
2737 * @wbc: optional writeback control for io accounting
2738 * @page: page to add to the bio
2739 * @pg_offset: offset of the new bio or to check whether we are adding
2740 * a contiguous page to the previous one
2741 * @size: portion of page that we want to write
2742 * @offset: starting offset in the page
2743 * @bdev: attach newly created bios to this bdev
2744 * @bio_ret: must be valid pointer, newly allocated bio will be stored there
2745 * @end_io_func: end_io callback for new bio
2746 * @mirror_num: desired mirror to read/write
2747 * @prev_bio_flags: flags of previous bio to see if we can merge the current one
2748 * @bio_flags: flags of the current bio to see if we can merge them
2750 static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
2751 struct writeback_control *wbc,
2752 struct page *page, u64 offset,
2753 size_t size, unsigned long pg_offset,
2754 struct block_device *bdev,
2755 struct bio **bio_ret,
2756 bio_end_io_t end_io_func,
2758 unsigned long prev_bio_flags,
2759 unsigned long bio_flags,
2760 bool force_bio_submit)
2764 size_t page_size = min_t(size_t, size, PAGE_SIZE);
2765 sector_t sector = offset >> 9;
2771 bool can_merge = true;
2774 if (prev_bio_flags & EXTENT_BIO_COMPRESSED)
2775 contig = bio->bi_iter.bi_sector == sector;
2777 contig = bio_end_sector(bio) == sector;
2779 if (tree->ops && btrfs_merge_bio_hook(page, offset, page_size,
2783 if (prev_bio_flags != bio_flags || !contig || !can_merge ||
2785 bio_add_page(bio, page, page_size, pg_offset) < page_size) {
2786 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
2794 wbc_account_io(wbc, page, page_size);
2799 bio = btrfs_bio_alloc(bdev, offset);
2800 bio_add_page(bio, page, page_size, pg_offset);
2801 bio->bi_end_io = end_io_func;
2802 bio->bi_private = tree;
2803 bio->bi_write_hint = page->mapping->host->i_write_hint;
2806 wbc_init_bio(wbc, bio);
2807 wbc_account_io(wbc, page, page_size);
2815 static void attach_extent_buffer_page(struct extent_buffer *eb,
2818 if (!PagePrivate(page)) {
2819 SetPagePrivate(page);
2821 set_page_private(page, (unsigned long)eb);
2823 WARN_ON(page->private != (unsigned long)eb);
2827 void set_page_extent_mapped(struct page *page)
2829 if (!PagePrivate(page)) {
2830 SetPagePrivate(page);
2832 set_page_private(page, EXTENT_PAGE_PRIVATE);
2836 static struct extent_map *
2837 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
2838 u64 start, u64 len, get_extent_t *get_extent,
2839 struct extent_map **em_cached)
2841 struct extent_map *em;
2843 if (em_cached && *em_cached) {
2845 if (extent_map_in_tree(em) && start >= em->start &&
2846 start < extent_map_end(em)) {
2847 refcount_inc(&em->refs);
2851 free_extent_map(em);
2855 em = get_extent(BTRFS_I(inode), page, pg_offset, start, len, 0);
2856 if (em_cached && !IS_ERR_OR_NULL(em)) {
2858 refcount_inc(&em->refs);
2864 * basic readpage implementation. Locked extent state structs are inserted
2865 * into the tree that are removed when the IO is done (by the end_io
2867 * XXX JDM: This needs looking at to ensure proper page locking
2868 * return 0 on success, otherwise return error
2870 static int __do_readpage(struct extent_io_tree *tree,
2872 get_extent_t *get_extent,
2873 struct extent_map **em_cached,
2874 struct bio **bio, int mirror_num,
2875 unsigned long *bio_flags, unsigned int read_flags,
2878 struct inode *inode = page->mapping->host;
2879 u64 start = page_offset(page);
2880 const u64 end = start + PAGE_SIZE - 1;
2883 u64 last_byte = i_size_read(inode);
2886 struct extent_map *em;
2887 struct block_device *bdev;
2890 size_t pg_offset = 0;
2892 size_t disk_io_size;
2893 size_t blocksize = inode->i_sb->s_blocksize;
2894 unsigned long this_bio_flag = 0;
2896 set_page_extent_mapped(page);
2898 if (!PageUptodate(page)) {
2899 if (cleancache_get_page(page) == 0) {
2900 BUG_ON(blocksize != PAGE_SIZE);
2901 unlock_extent(tree, start, end);
2906 if (page->index == last_byte >> PAGE_SHIFT) {
2908 size_t zero_offset = last_byte & (PAGE_SIZE - 1);
2911 iosize = PAGE_SIZE - zero_offset;
2912 userpage = kmap_atomic(page);
2913 memset(userpage + zero_offset, 0, iosize);
2914 flush_dcache_page(page);
2915 kunmap_atomic(userpage);
2918 while (cur <= end) {
2919 bool force_bio_submit = false;
2922 if (cur >= last_byte) {
2924 struct extent_state *cached = NULL;
2926 iosize = PAGE_SIZE - pg_offset;
2927 userpage = kmap_atomic(page);
2928 memset(userpage + pg_offset, 0, iosize);
2929 flush_dcache_page(page);
2930 kunmap_atomic(userpage);
2931 set_extent_uptodate(tree, cur, cur + iosize - 1,
2933 unlock_extent_cached(tree, cur,
2934 cur + iosize - 1, &cached);
2937 em = __get_extent_map(inode, page, pg_offset, cur,
2938 end - cur + 1, get_extent, em_cached);
2939 if (IS_ERR_OR_NULL(em)) {
2941 unlock_extent(tree, cur, end);
2944 extent_offset = cur - em->start;
2945 BUG_ON(extent_map_end(em) <= cur);
2948 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2949 this_bio_flag |= EXTENT_BIO_COMPRESSED;
2950 extent_set_compress_type(&this_bio_flag,
2954 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2955 cur_end = min(extent_map_end(em) - 1, end);
2956 iosize = ALIGN(iosize, blocksize);
2957 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2958 disk_io_size = em->block_len;
2959 offset = em->block_start;
2961 offset = em->block_start + extent_offset;
2962 disk_io_size = iosize;
2965 block_start = em->block_start;
2966 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2967 block_start = EXTENT_MAP_HOLE;
2970 * If we have a file range that points to a compressed extent
2971 * and it's followed by a consecutive file range that points to
2972 * to the same compressed extent (possibly with a different
2973 * offset and/or length, so it either points to the whole extent
2974 * or only part of it), we must make sure we do not submit a
2975 * single bio to populate the pages for the 2 ranges because
2976 * this makes the compressed extent read zero out the pages
2977 * belonging to the 2nd range. Imagine the following scenario:
2980 * [0 - 8K] [8K - 24K]
2983 * points to extent X, points to extent X,
2984 * offset 4K, length of 8K offset 0, length 16K
2986 * [extent X, compressed length = 4K uncompressed length = 16K]
2988 * If the bio to read the compressed extent covers both ranges,
2989 * it will decompress extent X into the pages belonging to the
2990 * first range and then it will stop, zeroing out the remaining
2991 * pages that belong to the other range that points to extent X.
2992 * So here we make sure we submit 2 bios, one for the first
2993 * range and another one for the third range. Both will target
2994 * the same physical extent from disk, but we can't currently
2995 * make the compressed bio endio callback populate the pages
2996 * for both ranges because each compressed bio is tightly
2997 * coupled with a single extent map, and each range can have
2998 * an extent map with a different offset value relative to the
2999 * uncompressed data of our extent and different lengths. This
3000 * is a corner case so we prioritize correctness over
3001 * non-optimal behavior (submitting 2 bios for the same extent).
3003 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3004 prev_em_start && *prev_em_start != (u64)-1 &&
3005 *prev_em_start != em->orig_start)
3006 force_bio_submit = true;
3009 *prev_em_start = em->orig_start;
3011 free_extent_map(em);
3014 /* we've found a hole, just zero and go on */
3015 if (block_start == EXTENT_MAP_HOLE) {
3017 struct extent_state *cached = NULL;
3019 userpage = kmap_atomic(page);
3020 memset(userpage + pg_offset, 0, iosize);
3021 flush_dcache_page(page);
3022 kunmap_atomic(userpage);
3024 set_extent_uptodate(tree, cur, cur + iosize - 1,
3026 unlock_extent_cached(tree, cur,
3027 cur + iosize - 1, &cached);
3029 pg_offset += iosize;
3032 /* the get_extent function already copied into the page */
3033 if (test_range_bit(tree, cur, cur_end,
3034 EXTENT_UPTODATE, 1, NULL)) {
3035 check_page_uptodate(tree, page);
3036 unlock_extent(tree, cur, cur + iosize - 1);
3038 pg_offset += iosize;
3041 /* we have an inline extent but it didn't get marked up
3042 * to date. Error out
3044 if (block_start == EXTENT_MAP_INLINE) {
3046 unlock_extent(tree, cur, cur + iosize - 1);
3048 pg_offset += iosize;
3052 ret = submit_extent_page(REQ_OP_READ | read_flags, tree, NULL,
3053 page, offset, disk_io_size,
3054 pg_offset, bdev, bio,
3055 end_bio_extent_readpage, mirror_num,
3061 *bio_flags = this_bio_flag;
3064 unlock_extent(tree, cur, cur + iosize - 1);
3068 pg_offset += iosize;
3072 if (!PageError(page))
3073 SetPageUptodate(page);
3079 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
3080 struct page *pages[], int nr_pages,
3082 struct extent_map **em_cached,
3084 unsigned long *bio_flags,
3087 struct inode *inode;
3088 struct btrfs_ordered_extent *ordered;
3091 inode = pages[0]->mapping->host;
3093 lock_extent(tree, start, end);
3094 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
3098 unlock_extent(tree, start, end);
3099 btrfs_start_ordered_extent(inode, ordered, 1);
3100 btrfs_put_ordered_extent(ordered);
3103 for (index = 0; index < nr_pages; index++) {
3104 __do_readpage(tree, pages[index], btrfs_get_extent, em_cached,
3105 bio, 0, bio_flags, REQ_RAHEAD, prev_em_start);
3106 put_page(pages[index]);
3110 static void __extent_readpages(struct extent_io_tree *tree,
3111 struct page *pages[],
3113 struct extent_map **em_cached,
3114 struct bio **bio, unsigned long *bio_flags,
3121 int first_index = 0;
3123 for (index = 0; index < nr_pages; index++) {
3124 page_start = page_offset(pages[index]);
3127 end = start + PAGE_SIZE - 1;
3128 first_index = index;
3129 } else if (end + 1 == page_start) {
3132 __do_contiguous_readpages(tree, &pages[first_index],
3133 index - first_index, start,
3138 end = start + PAGE_SIZE - 1;
3139 first_index = index;
3144 __do_contiguous_readpages(tree, &pages[first_index],
3145 index - first_index, start,
3146 end, em_cached, bio,
3147 bio_flags, prev_em_start);
3150 static int __extent_read_full_page(struct extent_io_tree *tree,
3152 get_extent_t *get_extent,
3153 struct bio **bio, int mirror_num,
3154 unsigned long *bio_flags,
3155 unsigned int read_flags)
3157 struct inode *inode = page->mapping->host;
3158 struct btrfs_ordered_extent *ordered;
3159 u64 start = page_offset(page);
3160 u64 end = start + PAGE_SIZE - 1;
3164 lock_extent(tree, start, end);
3165 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
3169 unlock_extent(tree, start, end);
3170 btrfs_start_ordered_extent(inode, ordered, 1);
3171 btrfs_put_ordered_extent(ordered);
3174 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3175 bio_flags, read_flags, NULL);
3179 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3180 get_extent_t *get_extent, int mirror_num)
3182 struct bio *bio = NULL;
3183 unsigned long bio_flags = 0;
3186 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3189 ret = submit_one_bio(bio, mirror_num, bio_flags);
3193 static void update_nr_written(struct writeback_control *wbc,
3194 unsigned long nr_written)
3196 wbc->nr_to_write -= nr_written;
3200 * helper for __extent_writepage, doing all of the delayed allocation setup.
3202 * This returns 1 if our fill_delalloc function did all the work required
3203 * to write the page (copy into inline extent). In this case the IO has
3204 * been started and the page is already unlocked.
3206 * This returns 0 if all went well (page still locked)
3207 * This returns < 0 if there were errors (page still locked)
3209 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3210 struct page *page, struct writeback_control *wbc,
3211 struct extent_page_data *epd,
3213 unsigned long *nr_written)
3215 struct extent_io_tree *tree = epd->tree;
3216 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3218 u64 delalloc_to_write = 0;
3219 u64 delalloc_end = 0;
3221 int page_started = 0;
3223 if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
3226 while (delalloc_end < page_end) {
3227 nr_delalloc = find_lock_delalloc_range(inode, tree,
3231 BTRFS_MAX_EXTENT_SIZE);
3232 if (nr_delalloc == 0) {
3233 delalloc_start = delalloc_end + 1;
3236 ret = tree->ops->fill_delalloc(inode, page,
3241 /* File system has been set read-only */
3244 /* fill_delalloc should be return < 0 for error
3245 * but just in case, we use > 0 here meaning the
3246 * IO is started, so we don't want to return > 0
3247 * unless things are going well.
3249 ret = ret < 0 ? ret : -EIO;
3253 * delalloc_end is already one less than the total length, so
3254 * we don't subtract one from PAGE_SIZE
3256 delalloc_to_write += (delalloc_end - delalloc_start +
3257 PAGE_SIZE) >> PAGE_SHIFT;
3258 delalloc_start = delalloc_end + 1;
3260 if (wbc->nr_to_write < delalloc_to_write) {
3263 if (delalloc_to_write < thresh * 2)
3264 thresh = delalloc_to_write;
3265 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3269 /* did the fill delalloc function already unlock and start
3274 * we've unlocked the page, so we can't update
3275 * the mapping's writeback index, just update
3278 wbc->nr_to_write -= *nr_written;
3289 * helper for __extent_writepage. This calls the writepage start hooks,
3290 * and does the loop to map the page into extents and bios.
3292 * We return 1 if the IO is started and the page is unlocked,
3293 * 0 if all went well (page still locked)
3294 * < 0 if there were errors (page still locked)
3296 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3298 struct writeback_control *wbc,
3299 struct extent_page_data *epd,
3301 unsigned long nr_written,
3302 unsigned int write_flags, int *nr_ret)
3304 struct extent_io_tree *tree = epd->tree;
3305 u64 start = page_offset(page);
3306 u64 page_end = start + PAGE_SIZE - 1;
3312 struct extent_map *em;
3313 struct block_device *bdev;
3314 size_t pg_offset = 0;
3320 if (tree->ops && tree->ops->writepage_start_hook) {
3321 ret = tree->ops->writepage_start_hook(page, start,
3324 /* Fixup worker will requeue */
3326 wbc->pages_skipped++;
3328 redirty_page_for_writepage(wbc, page);
3330 update_nr_written(wbc, nr_written);
3337 * we don't want to touch the inode after unlocking the page,
3338 * so we update the mapping writeback index now
3340 update_nr_written(wbc, nr_written + 1);
3343 if (i_size <= start) {
3344 if (tree->ops && tree->ops->writepage_end_io_hook)
3345 tree->ops->writepage_end_io_hook(page, start,
3350 blocksize = inode->i_sb->s_blocksize;
3352 while (cur <= end) {
3356 if (cur >= i_size) {
3357 if (tree->ops && tree->ops->writepage_end_io_hook)
3358 tree->ops->writepage_end_io_hook(page, cur,
3362 em = btrfs_get_extent(BTRFS_I(inode), page, pg_offset, cur,
3364 if (IS_ERR_OR_NULL(em)) {
3366 ret = PTR_ERR_OR_ZERO(em);
3370 extent_offset = cur - em->start;
3371 em_end = extent_map_end(em);
3372 BUG_ON(em_end <= cur);
3374 iosize = min(em_end - cur, end - cur + 1);
3375 iosize = ALIGN(iosize, blocksize);
3376 offset = em->block_start + extent_offset;
3378 block_start = em->block_start;
3379 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3380 free_extent_map(em);
3384 * compressed and inline extents are written through other
3387 if (compressed || block_start == EXTENT_MAP_HOLE ||
3388 block_start == EXTENT_MAP_INLINE) {
3390 * end_io notification does not happen here for
3391 * compressed extents
3393 if (!compressed && tree->ops &&
3394 tree->ops->writepage_end_io_hook)
3395 tree->ops->writepage_end_io_hook(page, cur,
3398 else if (compressed) {
3399 /* we don't want to end_page_writeback on
3400 * a compressed extent. this happens
3407 pg_offset += iosize;
3411 btrfs_set_range_writeback(tree, cur, cur + iosize - 1);
3412 if (!PageWriteback(page)) {
3413 btrfs_err(BTRFS_I(inode)->root->fs_info,
3414 "page %lu not writeback, cur %llu end %llu",
3415 page->index, cur, end);
3418 ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
3419 page, offset, iosize, pg_offset,
3421 end_bio_extent_writepage,
3425 if (PageWriteback(page))
3426 end_page_writeback(page);
3430 pg_offset += iosize;
3439 * the writepage semantics are similar to regular writepage. extent
3440 * records are inserted to lock ranges in the tree, and as dirty areas
3441 * are found, they are marked writeback. Then the lock bits are removed
3442 * and the end_io handler clears the writeback ranges
3444 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3445 struct extent_page_data *epd)
3447 struct inode *inode = page->mapping->host;
3448 u64 start = page_offset(page);
3449 u64 page_end = start + PAGE_SIZE - 1;
3452 size_t pg_offset = 0;
3453 loff_t i_size = i_size_read(inode);
3454 unsigned long end_index = i_size >> PAGE_SHIFT;
3455 unsigned int write_flags = 0;
3456 unsigned long nr_written = 0;
3458 write_flags = wbc_to_write_flags(wbc);
3460 trace___extent_writepage(page, inode, wbc);
3462 WARN_ON(!PageLocked(page));
3464 ClearPageError(page);
3466 pg_offset = i_size & (PAGE_SIZE - 1);
3467 if (page->index > end_index ||
3468 (page->index == end_index && !pg_offset)) {
3469 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3474 if (page->index == end_index) {
3477 userpage = kmap_atomic(page);
3478 memset(userpage + pg_offset, 0,
3479 PAGE_SIZE - pg_offset);
3480 kunmap_atomic(userpage);
3481 flush_dcache_page(page);
3486 set_page_extent_mapped(page);
3488 ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
3494 ret = __extent_writepage_io(inode, page, wbc, epd,
3495 i_size, nr_written, write_flags, &nr);
3501 /* make sure the mapping tag for page dirty gets cleared */
3502 set_page_writeback(page);
3503 end_page_writeback(page);
3505 if (PageError(page)) {
3506 ret = ret < 0 ? ret : -EIO;
3507 end_extent_writepage(page, ret, start, page_end);
3516 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3518 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3519 TASK_UNINTERRUPTIBLE);
3522 static noinline_for_stack int
3523 lock_extent_buffer_for_io(struct extent_buffer *eb,
3524 struct btrfs_fs_info *fs_info,
3525 struct extent_page_data *epd)
3531 if (!btrfs_try_tree_write_lock(eb)) {
3533 flush_write_bio(epd);
3534 btrfs_tree_lock(eb);
3537 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3538 btrfs_tree_unlock(eb);
3542 flush_write_bio(epd);
3546 wait_on_extent_buffer_writeback(eb);
3547 btrfs_tree_lock(eb);
3548 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3550 btrfs_tree_unlock(eb);
3555 * We need to do this to prevent races in people who check if the eb is
3556 * under IO since we can end up having no IO bits set for a short period
3559 spin_lock(&eb->refs_lock);
3560 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3561 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3562 spin_unlock(&eb->refs_lock);
3563 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3564 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
3566 fs_info->dirty_metadata_batch);
3569 spin_unlock(&eb->refs_lock);
3572 btrfs_tree_unlock(eb);
3577 num_pages = num_extent_pages(eb);
3578 for (i = 0; i < num_pages; i++) {
3579 struct page *p = eb->pages[i];
3581 if (!trylock_page(p)) {
3583 flush_write_bio(epd);
3593 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3595 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3596 smp_mb__after_atomic();
3597 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3600 static void set_btree_ioerr(struct page *page)
3602 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3605 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3609 * If writeback for a btree extent that doesn't belong to a log tree
3610 * failed, increment the counter transaction->eb_write_errors.
3611 * We do this because while the transaction is running and before it's
3612 * committing (when we call filemap_fdata[write|wait]_range against
3613 * the btree inode), we might have
3614 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3615 * returns an error or an error happens during writeback, when we're
3616 * committing the transaction we wouldn't know about it, since the pages
3617 * can be no longer dirty nor marked anymore for writeback (if a
3618 * subsequent modification to the extent buffer didn't happen before the
3619 * transaction commit), which makes filemap_fdata[write|wait]_range not
3620 * able to find the pages tagged with SetPageError at transaction
3621 * commit time. So if this happens we must abort the transaction,
3622 * otherwise we commit a super block with btree roots that point to
3623 * btree nodes/leafs whose content on disk is invalid - either garbage
3624 * or the content of some node/leaf from a past generation that got
3625 * cowed or deleted and is no longer valid.
3627 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3628 * not be enough - we need to distinguish between log tree extents vs
3629 * non-log tree extents, and the next filemap_fdatawait_range() call
3630 * will catch and clear such errors in the mapping - and that call might
3631 * be from a log sync and not from a transaction commit. Also, checking
3632 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3633 * not done and would not be reliable - the eb might have been released
3634 * from memory and reading it back again means that flag would not be
3635 * set (since it's a runtime flag, not persisted on disk).
3637 * Using the flags below in the btree inode also makes us achieve the
3638 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3639 * writeback for all dirty pages and before filemap_fdatawait_range()
3640 * is called, the writeback for all dirty pages had already finished
3641 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3642 * filemap_fdatawait_range() would return success, as it could not know
3643 * that writeback errors happened (the pages were no longer tagged for
3646 switch (eb->log_index) {
3648 set_bit(BTRFS_FS_BTREE_ERR, &eb->fs_info->flags);
3651 set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags);
3654 set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags);
3657 BUG(); /* unexpected, logic error */
3661 static void end_bio_extent_buffer_writepage(struct bio *bio)
3663 struct bio_vec *bvec;
3664 struct extent_buffer *eb;
3667 ASSERT(!bio_flagged(bio, BIO_CLONED));
3668 bio_for_each_segment_all(bvec, bio, i) {
3669 struct page *page = bvec->bv_page;
3671 eb = (struct extent_buffer *)page->private;
3673 done = atomic_dec_and_test(&eb->io_pages);
3675 if (bio->bi_status ||
3676 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3677 ClearPageUptodate(page);
3678 set_btree_ioerr(page);
3681 end_page_writeback(page);
3686 end_extent_buffer_writeback(eb);
3692 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3693 struct btrfs_fs_info *fs_info,
3694 struct writeback_control *wbc,
3695 struct extent_page_data *epd)
3697 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3698 struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
3699 u64 offset = eb->start;
3702 unsigned long start, end;
3703 unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META;
3706 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3707 num_pages = num_extent_pages(eb);
3708 atomic_set(&eb->io_pages, num_pages);
3710 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3711 nritems = btrfs_header_nritems(eb);
3712 if (btrfs_header_level(eb) > 0) {
3713 end = btrfs_node_key_ptr_offset(nritems);
3715 memzero_extent_buffer(eb, end, eb->len - end);
3719 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3721 start = btrfs_item_nr_offset(nritems);
3722 end = BTRFS_LEAF_DATA_OFFSET + leaf_data_end(fs_info, eb);
3723 memzero_extent_buffer(eb, start, end - start);
3726 for (i = 0; i < num_pages; i++) {
3727 struct page *p = eb->pages[i];
3729 clear_page_dirty_for_io(p);
3730 set_page_writeback(p);
3731 ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
3732 p, offset, PAGE_SIZE, 0, bdev,
3734 end_bio_extent_buffer_writepage,
3738 if (PageWriteback(p))
3739 end_page_writeback(p);
3740 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3741 end_extent_buffer_writeback(eb);
3745 offset += PAGE_SIZE;
3746 update_nr_written(wbc, 1);
3750 if (unlikely(ret)) {
3751 for (; i < num_pages; i++) {
3752 struct page *p = eb->pages[i];
3753 clear_page_dirty_for_io(p);
3761 int btree_write_cache_pages(struct address_space *mapping,
3762 struct writeback_control *wbc)
3764 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3765 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3766 struct extent_buffer *eb, *prev_eb = NULL;
3767 struct extent_page_data epd = {
3771 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3775 int nr_to_write_done = 0;
3776 struct pagevec pvec;
3779 pgoff_t end; /* Inclusive */
3783 pagevec_init(&pvec);
3784 if (wbc->range_cyclic) {
3785 index = mapping->writeback_index; /* Start from prev offset */
3788 index = wbc->range_start >> PAGE_SHIFT;
3789 end = wbc->range_end >> PAGE_SHIFT;
3792 if (wbc->sync_mode == WB_SYNC_ALL)
3793 tag = PAGECACHE_TAG_TOWRITE;
3795 tag = PAGECACHE_TAG_DIRTY;
3797 if (wbc->sync_mode == WB_SYNC_ALL)
3798 tag_pages_for_writeback(mapping, index, end);
3799 while (!done && !nr_to_write_done && (index <= end) &&
3800 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
3805 for (i = 0; i < nr_pages; i++) {
3806 struct page *page = pvec.pages[i];
3808 if (!PagePrivate(page))
3811 spin_lock(&mapping->private_lock);
3812 if (!PagePrivate(page)) {
3813 spin_unlock(&mapping->private_lock);
3817 eb = (struct extent_buffer *)page->private;
3820 * Shouldn't happen and normally this would be a BUG_ON
3821 * but no sense in crashing the users box for something
3822 * we can survive anyway.
3825 spin_unlock(&mapping->private_lock);
3829 if (eb == prev_eb) {
3830 spin_unlock(&mapping->private_lock);
3834 ret = atomic_inc_not_zero(&eb->refs);
3835 spin_unlock(&mapping->private_lock);
3840 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3842 free_extent_buffer(eb);
3846 ret = write_one_eb(eb, fs_info, wbc, &epd);
3849 free_extent_buffer(eb);
3852 free_extent_buffer(eb);
3855 * the filesystem may choose to bump up nr_to_write.
3856 * We have to make sure to honor the new nr_to_write
3859 nr_to_write_done = wbc->nr_to_write <= 0;
3861 pagevec_release(&pvec);
3864 if (!scanned && !done) {
3866 * We hit the last page and there is more work to be done: wrap
3867 * back to the start of the file
3873 flush_write_bio(&epd);
3878 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3879 * @mapping: address space structure to write
3880 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3881 * @data: data passed to __extent_writepage function
3883 * If a page is already under I/O, write_cache_pages() skips it, even
3884 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3885 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3886 * and msync() need to guarantee that all the data which was dirty at the time
3887 * the call was made get new I/O started against them. If wbc->sync_mode is
3888 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3889 * existing IO to complete.
3891 static int extent_write_cache_pages(struct address_space *mapping,
3892 struct writeback_control *wbc,
3893 struct extent_page_data *epd)
3895 struct inode *inode = mapping->host;
3898 int nr_to_write_done = 0;
3899 struct pagevec pvec;
3902 pgoff_t end; /* Inclusive */
3904 int range_whole = 0;
3909 * We have to hold onto the inode so that ordered extents can do their
3910 * work when the IO finishes. The alternative to this is failing to add
3911 * an ordered extent if the igrab() fails there and that is a huge pain
3912 * to deal with, so instead just hold onto the inode throughout the
3913 * writepages operation. If it fails here we are freeing up the inode
3914 * anyway and we'd rather not waste our time writing out stuff that is
3915 * going to be truncated anyway.
3920 pagevec_init(&pvec);
3921 if (wbc->range_cyclic) {
3922 index = mapping->writeback_index; /* Start from prev offset */
3925 index = wbc->range_start >> PAGE_SHIFT;
3926 end = wbc->range_end >> PAGE_SHIFT;
3927 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
3931 if (wbc->sync_mode == WB_SYNC_ALL)
3932 tag = PAGECACHE_TAG_TOWRITE;
3934 tag = PAGECACHE_TAG_DIRTY;
3936 if (wbc->sync_mode == WB_SYNC_ALL)
3937 tag_pages_for_writeback(mapping, index, end);
3939 while (!done && !nr_to_write_done && (index <= end) &&
3940 (nr_pages = pagevec_lookup_range_tag(&pvec, mapping,
3941 &index, end, tag))) {
3945 for (i = 0; i < nr_pages; i++) {
3946 struct page *page = pvec.pages[i];
3948 done_index = page->index;
3950 * At this point we hold neither the i_pages lock nor
3951 * the page lock: the page may be truncated or
3952 * invalidated (changing page->mapping to NULL),
3953 * or even swizzled back from swapper_space to
3954 * tmpfs file mapping
3956 if (!trylock_page(page)) {
3957 flush_write_bio(epd);
3961 if (unlikely(page->mapping != mapping)) {
3966 if (wbc->sync_mode != WB_SYNC_NONE) {
3967 if (PageWriteback(page))
3968 flush_write_bio(epd);
3969 wait_on_page_writeback(page);
3972 if (PageWriteback(page) ||
3973 !clear_page_dirty_for_io(page)) {
3978 ret = __extent_writepage(page, wbc, epd);
3980 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
3986 * done_index is set past this page,
3987 * so media errors will not choke
3988 * background writeout for the entire
3989 * file. This has consequences for
3990 * range_cyclic semantics (ie. it may
3991 * not be suitable for data integrity
3994 done_index = page->index + 1;
4000 * the filesystem may choose to bump up nr_to_write.
4001 * We have to make sure to honor the new nr_to_write
4004 nr_to_write_done = wbc->nr_to_write <= 0;
4006 pagevec_release(&pvec);
4009 if (!scanned && !done) {
4011 * We hit the last page and there is more work to be done: wrap
4012 * back to the start of the file
4019 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4020 mapping->writeback_index = done_index;
4022 btrfs_add_delayed_iput(inode);
4026 static void flush_write_bio(struct extent_page_data *epd)
4031 ret = submit_one_bio(epd->bio, 0, 0);
4032 BUG_ON(ret < 0); /* -ENOMEM */
4037 int extent_write_full_page(struct page *page, struct writeback_control *wbc)
4040 struct extent_page_data epd = {
4042 .tree = &BTRFS_I(page->mapping->host)->io_tree,
4044 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4047 ret = __extent_writepage(page, wbc, &epd);
4049 flush_write_bio(&epd);
4053 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
4057 struct address_space *mapping = inode->i_mapping;
4058 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
4060 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4063 struct extent_page_data epd = {
4067 .sync_io = mode == WB_SYNC_ALL,
4069 struct writeback_control wbc_writepages = {
4071 .nr_to_write = nr_pages * 2,
4072 .range_start = start,
4073 .range_end = end + 1,
4076 while (start <= end) {
4077 page = find_get_page(mapping, start >> PAGE_SHIFT);
4078 if (clear_page_dirty_for_io(page))
4079 ret = __extent_writepage(page, &wbc_writepages, &epd);
4081 if (tree->ops && tree->ops->writepage_end_io_hook)
4082 tree->ops->writepage_end_io_hook(page, start,
4083 start + PAGE_SIZE - 1,
4091 flush_write_bio(&epd);
4095 int extent_writepages(struct address_space *mapping,
4096 struct writeback_control *wbc)
4099 struct extent_page_data epd = {
4101 .tree = &BTRFS_I(mapping->host)->io_tree,
4103 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4106 ret = extent_write_cache_pages(mapping, wbc, &epd);
4107 flush_write_bio(&epd);
4111 int extent_readpages(struct address_space *mapping, struct list_head *pages,
4114 struct bio *bio = NULL;
4116 unsigned long bio_flags = 0;
4117 struct page *pagepool[16];
4119 struct extent_map *em_cached = NULL;
4120 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
4122 u64 prev_em_start = (u64)-1;
4124 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
4125 page = list_entry(pages->prev, struct page, lru);
4127 prefetchw(&page->flags);
4128 list_del(&page->lru);
4129 if (add_to_page_cache_lru(page, mapping,
4131 readahead_gfp_mask(mapping))) {
4136 pagepool[nr++] = page;
4137 if (nr < ARRAY_SIZE(pagepool))
4139 __extent_readpages(tree, pagepool, nr, &em_cached, &bio,
4140 &bio_flags, &prev_em_start);
4144 __extent_readpages(tree, pagepool, nr, &em_cached, &bio,
4145 &bio_flags, &prev_em_start);
4148 free_extent_map(em_cached);
4150 BUG_ON(!list_empty(pages));
4152 return submit_one_bio(bio, 0, bio_flags);
4157 * basic invalidatepage code, this waits on any locked or writeback
4158 * ranges corresponding to the page, and then deletes any extent state
4159 * records from the tree
4161 int extent_invalidatepage(struct extent_io_tree *tree,
4162 struct page *page, unsigned long offset)
4164 struct extent_state *cached_state = NULL;
4165 u64 start = page_offset(page);
4166 u64 end = start + PAGE_SIZE - 1;
4167 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4169 start += ALIGN(offset, blocksize);
4173 lock_extent_bits(tree, start, end, &cached_state);
4174 wait_on_page_writeback(page);
4175 clear_extent_bit(tree, start, end,
4176 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
4177 EXTENT_DO_ACCOUNTING,
4178 1, 1, &cached_state);
4183 * a helper for releasepage, this tests for areas of the page that
4184 * are locked or under IO and drops the related state bits if it is safe
4187 static int try_release_extent_state(struct extent_io_tree *tree,
4188 struct page *page, gfp_t mask)
4190 u64 start = page_offset(page);
4191 u64 end = start + PAGE_SIZE - 1;
4194 if (test_range_bit(tree, start, end,
4195 EXTENT_IOBITS, 0, NULL))
4199 * at this point we can safely clear everything except the
4200 * locked bit and the nodatasum bit
4202 ret = __clear_extent_bit(tree, start, end,
4203 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4204 0, 0, NULL, mask, NULL);
4206 /* if clear_extent_bit failed for enomem reasons,
4207 * we can't allow the release to continue.
4218 * a helper for releasepage. As long as there are no locked extents
4219 * in the range corresponding to the page, both state records and extent
4220 * map records are removed
4222 int try_release_extent_mapping(struct page *page, gfp_t mask)
4224 struct extent_map *em;
4225 u64 start = page_offset(page);
4226 u64 end = start + PAGE_SIZE - 1;
4227 struct btrfs_inode *btrfs_inode = BTRFS_I(page->mapping->host);
4228 struct extent_io_tree *tree = &btrfs_inode->io_tree;
4229 struct extent_map_tree *map = &btrfs_inode->extent_tree;
4231 if (gfpflags_allow_blocking(mask) &&
4232 page->mapping->host->i_size > SZ_16M) {
4234 while (start <= end) {
4235 len = end - start + 1;
4236 write_lock(&map->lock);
4237 em = lookup_extent_mapping(map, start, len);
4239 write_unlock(&map->lock);
4242 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4243 em->start != start) {
4244 write_unlock(&map->lock);
4245 free_extent_map(em);
4248 if (!test_range_bit(tree, em->start,
4249 extent_map_end(em) - 1,
4250 EXTENT_LOCKED | EXTENT_WRITEBACK,
4252 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4253 &btrfs_inode->runtime_flags);
4254 remove_extent_mapping(map, em);
4255 /* once for the rb tree */
4256 free_extent_map(em);
4258 start = extent_map_end(em);
4259 write_unlock(&map->lock);
4262 free_extent_map(em);
4265 return try_release_extent_state(tree, page, mask);
4269 * helper function for fiemap, which doesn't want to see any holes.
4270 * This maps until we find something past 'last'
4272 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4273 u64 offset, u64 last)
4275 u64 sectorsize = btrfs_inode_sectorsize(inode);
4276 struct extent_map *em;
4283 len = last - offset;
4286 len = ALIGN(len, sectorsize);
4287 em = btrfs_get_extent_fiemap(BTRFS_I(inode), NULL, 0, offset,
4289 if (IS_ERR_OR_NULL(em))
4292 /* if this isn't a hole return it */
4293 if (em->block_start != EXTENT_MAP_HOLE)
4296 /* this is a hole, advance to the next extent */
4297 offset = extent_map_end(em);
4298 free_extent_map(em);
4306 * To cache previous fiemap extent
4308 * Will be used for merging fiemap extent
4310 struct fiemap_cache {
4319 * Helper to submit fiemap extent.
4321 * Will try to merge current fiemap extent specified by @offset, @phys,
4322 * @len and @flags with cached one.
4323 * And only when we fails to merge, cached one will be submitted as
4326 * Return value is the same as fiemap_fill_next_extent().
4328 static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
4329 struct fiemap_cache *cache,
4330 u64 offset, u64 phys, u64 len, u32 flags)
4338 * Sanity check, extent_fiemap() should have ensured that new
4339 * fiemap extent won't overlap with cahced one.
4342 * NOTE: Physical address can overlap, due to compression
4344 if (cache->offset + cache->len > offset) {
4350 * Only merges fiemap extents if
4351 * 1) Their logical addresses are continuous
4353 * 2) Their physical addresses are continuous
4354 * So truly compressed (physical size smaller than logical size)
4355 * extents won't get merged with each other
4357 * 3) Share same flags except FIEMAP_EXTENT_LAST
4358 * So regular extent won't get merged with prealloc extent
4360 if (cache->offset + cache->len == offset &&
4361 cache->phys + cache->len == phys &&
4362 (cache->flags & ~FIEMAP_EXTENT_LAST) ==
4363 (flags & ~FIEMAP_EXTENT_LAST)) {
4365 cache->flags |= flags;
4366 goto try_submit_last;
4369 /* Not mergeable, need to submit cached one */
4370 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4371 cache->len, cache->flags);
4372 cache->cached = false;
4376 cache->cached = true;
4377 cache->offset = offset;
4380 cache->flags = flags;
4382 if (cache->flags & FIEMAP_EXTENT_LAST) {
4383 ret = fiemap_fill_next_extent(fieinfo, cache->offset,
4384 cache->phys, cache->len, cache->flags);
4385 cache->cached = false;
4391 * Emit last fiemap cache
4393 * The last fiemap cache may still be cached in the following case:
4395 * |<- Fiemap range ->|
4396 * |<------------ First extent ----------->|
4398 * In this case, the first extent range will be cached but not emitted.
4399 * So we must emit it before ending extent_fiemap().
4401 static int emit_last_fiemap_cache(struct btrfs_fs_info *fs_info,
4402 struct fiemap_extent_info *fieinfo,
4403 struct fiemap_cache *cache)
4410 ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
4411 cache->len, cache->flags);
4412 cache->cached = false;
4418 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4419 __u64 start, __u64 len)
4423 u64 max = start + len;
4427 u64 last_for_get_extent = 0;
4429 u64 isize = i_size_read(inode);
4430 struct btrfs_key found_key;
4431 struct extent_map *em = NULL;
4432 struct extent_state *cached_state = NULL;
4433 struct btrfs_path *path;
4434 struct btrfs_root *root = BTRFS_I(inode)->root;
4435 struct fiemap_cache cache = { 0 };
4444 path = btrfs_alloc_path();
4447 path->leave_spinning = 1;
4449 start = round_down(start, btrfs_inode_sectorsize(inode));
4450 len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
4453 * lookup the last file extent. We're not using i_size here
4454 * because there might be preallocation past i_size
4456 ret = btrfs_lookup_file_extent(NULL, root, path,
4457 btrfs_ino(BTRFS_I(inode)), -1, 0);
4459 btrfs_free_path(path);
4468 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4469 found_type = found_key.type;
4471 /* No extents, but there might be delalloc bits */
4472 if (found_key.objectid != btrfs_ino(BTRFS_I(inode)) ||
4473 found_type != BTRFS_EXTENT_DATA_KEY) {
4474 /* have to trust i_size as the end */
4476 last_for_get_extent = isize;
4479 * remember the start of the last extent. There are a
4480 * bunch of different factors that go into the length of the
4481 * extent, so its much less complex to remember where it started
4483 last = found_key.offset;
4484 last_for_get_extent = last + 1;
4486 btrfs_release_path(path);
4489 * we might have some extents allocated but more delalloc past those
4490 * extents. so, we trust isize unless the start of the last extent is
4495 last_for_get_extent = isize;
4498 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4501 em = get_extent_skip_holes(inode, start, last_for_get_extent);
4510 u64 offset_in_extent = 0;
4512 /* break if the extent we found is outside the range */
4513 if (em->start >= max || extent_map_end(em) < off)
4517 * get_extent may return an extent that starts before our
4518 * requested range. We have to make sure the ranges
4519 * we return to fiemap always move forward and don't
4520 * overlap, so adjust the offsets here
4522 em_start = max(em->start, off);
4525 * record the offset from the start of the extent
4526 * for adjusting the disk offset below. Only do this if the
4527 * extent isn't compressed since our in ram offset may be past
4528 * what we have actually allocated on disk.
4530 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4531 offset_in_extent = em_start - em->start;
4532 em_end = extent_map_end(em);
4533 em_len = em_end - em_start;
4535 if (em->block_start < EXTENT_MAP_LAST_BYTE)
4536 disko = em->block_start + offset_in_extent;
4541 * bump off for our next call to get_extent
4543 off = extent_map_end(em);
4547 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4549 flags |= FIEMAP_EXTENT_LAST;
4550 } else if (em->block_start == EXTENT_MAP_INLINE) {
4551 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4552 FIEMAP_EXTENT_NOT_ALIGNED);
4553 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4554 flags |= (FIEMAP_EXTENT_DELALLOC |
4555 FIEMAP_EXTENT_UNKNOWN);
4556 } else if (fieinfo->fi_extents_max) {
4557 u64 bytenr = em->block_start -
4558 (em->start - em->orig_start);
4561 * As btrfs supports shared space, this information
4562 * can be exported to userspace tools via
4563 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4564 * then we're just getting a count and we can skip the
4567 ret = btrfs_check_shared(root,
4568 btrfs_ino(BTRFS_I(inode)),
4573 flags |= FIEMAP_EXTENT_SHARED;
4576 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4577 flags |= FIEMAP_EXTENT_ENCODED;
4578 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4579 flags |= FIEMAP_EXTENT_UNWRITTEN;
4581 free_extent_map(em);
4583 if ((em_start >= last) || em_len == (u64)-1 ||
4584 (last == (u64)-1 && isize <= em_end)) {
4585 flags |= FIEMAP_EXTENT_LAST;
4589 /* now scan forward to see if this is really the last extent. */
4590 em = get_extent_skip_holes(inode, off, last_for_get_extent);
4596 flags |= FIEMAP_EXTENT_LAST;
4599 ret = emit_fiemap_extent(fieinfo, &cache, em_start, disko,
4609 ret = emit_last_fiemap_cache(root->fs_info, fieinfo, &cache);
4610 free_extent_map(em);
4612 btrfs_free_path(path);
4613 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4618 static void __free_extent_buffer(struct extent_buffer *eb)
4620 btrfs_leak_debug_del(&eb->leak_list);
4621 kmem_cache_free(extent_buffer_cache, eb);
4624 int extent_buffer_under_io(struct extent_buffer *eb)
4626 return (atomic_read(&eb->io_pages) ||
4627 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4628 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4632 * Release all pages attached to the extent buffer.
4634 static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb)
4638 int mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
4640 BUG_ON(extent_buffer_under_io(eb));
4642 num_pages = num_extent_pages(eb);
4643 for (i = 0; i < num_pages; i++) {
4644 struct page *page = eb->pages[i];
4649 spin_lock(&page->mapping->private_lock);
4651 * We do this since we'll remove the pages after we've
4652 * removed the eb from the radix tree, so we could race
4653 * and have this page now attached to the new eb. So
4654 * only clear page_private if it's still connected to
4657 if (PagePrivate(page) &&
4658 page->private == (unsigned long)eb) {
4659 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4660 BUG_ON(PageDirty(page));
4661 BUG_ON(PageWriteback(page));
4663 * We need to make sure we haven't be attached
4666 ClearPagePrivate(page);
4667 set_page_private(page, 0);
4668 /* One for the page private */
4673 spin_unlock(&page->mapping->private_lock);
4675 /* One for when we allocated the page */
4681 * Helper for releasing the extent buffer.
4683 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4685 btrfs_release_extent_buffer_pages(eb);
4686 __free_extent_buffer(eb);
4689 static struct extent_buffer *
4690 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4693 struct extent_buffer *eb = NULL;
4695 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4698 eb->fs_info = fs_info;
4700 rwlock_init(&eb->lock);
4701 atomic_set(&eb->write_locks, 0);
4702 atomic_set(&eb->read_locks, 0);
4703 atomic_set(&eb->blocking_readers, 0);
4704 atomic_set(&eb->blocking_writers, 0);
4705 atomic_set(&eb->spinning_readers, 0);
4706 atomic_set(&eb->spinning_writers, 0);
4707 eb->lock_nested = 0;
4708 init_waitqueue_head(&eb->write_lock_wq);
4709 init_waitqueue_head(&eb->read_lock_wq);
4711 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4713 spin_lock_init(&eb->refs_lock);
4714 atomic_set(&eb->refs, 1);
4715 atomic_set(&eb->io_pages, 0);
4718 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4720 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4721 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4722 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4727 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4731 struct extent_buffer *new;
4732 int num_pages = num_extent_pages(src);
4734 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
4738 for (i = 0; i < num_pages; i++) {
4739 p = alloc_page(GFP_NOFS);
4741 btrfs_release_extent_buffer(new);
4744 attach_extent_buffer_page(new, p);
4745 WARN_ON(PageDirty(p));
4748 copy_page(page_address(p), page_address(src->pages[i]));
4751 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4752 set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags);
4757 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4758 u64 start, unsigned long len)
4760 struct extent_buffer *eb;
4764 eb = __alloc_extent_buffer(fs_info, start, len);
4768 num_pages = num_extent_pages(eb);
4769 for (i = 0; i < num_pages; i++) {
4770 eb->pages[i] = alloc_page(GFP_NOFS);
4774 set_extent_buffer_uptodate(eb);
4775 btrfs_set_header_nritems(eb, 0);
4776 set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
4781 __free_page(eb->pages[i - 1]);
4782 __free_extent_buffer(eb);
4786 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4789 return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
4792 static void check_buffer_tree_ref(struct extent_buffer *eb)
4795 /* the ref bit is tricky. We have to make sure it is set
4796 * if we have the buffer dirty. Otherwise the
4797 * code to free a buffer can end up dropping a dirty
4800 * Once the ref bit is set, it won't go away while the
4801 * buffer is dirty or in writeback, and it also won't
4802 * go away while we have the reference count on the
4805 * We can't just set the ref bit without bumping the
4806 * ref on the eb because free_extent_buffer might
4807 * see the ref bit and try to clear it. If this happens
4808 * free_extent_buffer might end up dropping our original
4809 * ref by mistake and freeing the page before we are able
4810 * to add one more ref.
4812 * So bump the ref count first, then set the bit. If someone
4813 * beat us to it, drop the ref we added.
4815 refs = atomic_read(&eb->refs);
4816 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4819 spin_lock(&eb->refs_lock);
4820 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4821 atomic_inc(&eb->refs);
4822 spin_unlock(&eb->refs_lock);
4825 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
4826 struct page *accessed)
4830 check_buffer_tree_ref(eb);
4832 num_pages = num_extent_pages(eb);
4833 for (i = 0; i < num_pages; i++) {
4834 struct page *p = eb->pages[i];
4837 mark_page_accessed(p);
4841 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
4844 struct extent_buffer *eb;
4847 eb = radix_tree_lookup(&fs_info->buffer_radix,
4848 start >> PAGE_SHIFT);
4849 if (eb && atomic_inc_not_zero(&eb->refs)) {
4852 * Lock our eb's refs_lock to avoid races with
4853 * free_extent_buffer. When we get our eb it might be flagged
4854 * with EXTENT_BUFFER_STALE and another task running
4855 * free_extent_buffer might have seen that flag set,
4856 * eb->refs == 2, that the buffer isn't under IO (dirty and
4857 * writeback flags not set) and it's still in the tree (flag
4858 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4859 * of decrementing the extent buffer's reference count twice.
4860 * So here we could race and increment the eb's reference count,
4861 * clear its stale flag, mark it as dirty and drop our reference
4862 * before the other task finishes executing free_extent_buffer,
4863 * which would later result in an attempt to free an extent
4864 * buffer that is dirty.
4866 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
4867 spin_lock(&eb->refs_lock);
4868 spin_unlock(&eb->refs_lock);
4870 mark_extent_buffer_accessed(eb, NULL);
4878 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4879 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
4882 struct extent_buffer *eb, *exists = NULL;
4885 eb = find_extent_buffer(fs_info, start);
4888 eb = alloc_dummy_extent_buffer(fs_info, start);
4891 eb->fs_info = fs_info;
4893 ret = radix_tree_preload(GFP_NOFS);
4896 spin_lock(&fs_info->buffer_lock);
4897 ret = radix_tree_insert(&fs_info->buffer_radix,
4898 start >> PAGE_SHIFT, eb);
4899 spin_unlock(&fs_info->buffer_lock);
4900 radix_tree_preload_end();
4901 if (ret == -EEXIST) {
4902 exists = find_extent_buffer(fs_info, start);
4908 check_buffer_tree_ref(eb);
4909 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4912 * We will free dummy extent buffer's if they come into
4913 * free_extent_buffer with a ref count of 2, but if we are using this we
4914 * want the buffers to stay in memory until we're done with them, so
4915 * bump the ref count again.
4917 atomic_inc(&eb->refs);
4920 btrfs_release_extent_buffer(eb);
4925 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
4928 unsigned long len = fs_info->nodesize;
4931 unsigned long index = start >> PAGE_SHIFT;
4932 struct extent_buffer *eb;
4933 struct extent_buffer *exists = NULL;
4935 struct address_space *mapping = fs_info->btree_inode->i_mapping;
4939 if (!IS_ALIGNED(start, fs_info->sectorsize)) {
4940 btrfs_err(fs_info, "bad tree block start %llu", start);
4941 return ERR_PTR(-EINVAL);
4944 eb = find_extent_buffer(fs_info, start);
4948 eb = __alloc_extent_buffer(fs_info, start, len);
4950 return ERR_PTR(-ENOMEM);
4952 num_pages = num_extent_pages(eb);
4953 for (i = 0; i < num_pages; i++, index++) {
4954 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
4956 exists = ERR_PTR(-ENOMEM);
4960 spin_lock(&mapping->private_lock);
4961 if (PagePrivate(p)) {
4963 * We could have already allocated an eb for this page
4964 * and attached one so lets see if we can get a ref on
4965 * the existing eb, and if we can we know it's good and
4966 * we can just return that one, else we know we can just
4967 * overwrite page->private.
4969 exists = (struct extent_buffer *)p->private;
4970 if (atomic_inc_not_zero(&exists->refs)) {
4971 spin_unlock(&mapping->private_lock);
4974 mark_extent_buffer_accessed(exists, p);
4980 * Do this so attach doesn't complain and we need to
4981 * drop the ref the old guy had.
4983 ClearPagePrivate(p);
4984 WARN_ON(PageDirty(p));
4987 attach_extent_buffer_page(eb, p);
4988 spin_unlock(&mapping->private_lock);
4989 WARN_ON(PageDirty(p));
4991 if (!PageUptodate(p))
4995 * We can't unlock the pages just yet since the extent buffer
4996 * hasn't been properly inserted in the radix tree, this
4997 * opens a race with btree_releasepage which can free a page
4998 * while we are still filling in all pages for the buffer and
5003 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5005 ret = radix_tree_preload(GFP_NOFS);
5007 exists = ERR_PTR(ret);
5011 spin_lock(&fs_info->buffer_lock);
5012 ret = radix_tree_insert(&fs_info->buffer_radix,
5013 start >> PAGE_SHIFT, eb);
5014 spin_unlock(&fs_info->buffer_lock);
5015 radix_tree_preload_end();
5016 if (ret == -EEXIST) {
5017 exists = find_extent_buffer(fs_info, start);
5023 /* add one reference for the tree */
5024 check_buffer_tree_ref(eb);
5025 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
5028 * Now it's safe to unlock the pages because any calls to
5029 * btree_releasepage will correctly detect that a page belongs to a
5030 * live buffer and won't free them prematurely.
5032 for (i = 0; i < num_pages; i++)
5033 unlock_page(eb->pages[i]);
5037 WARN_ON(!atomic_dec_and_test(&eb->refs));
5038 for (i = 0; i < num_pages; i++) {
5040 unlock_page(eb->pages[i]);
5043 btrfs_release_extent_buffer(eb);
5047 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5049 struct extent_buffer *eb =
5050 container_of(head, struct extent_buffer, rcu_head);
5052 __free_extent_buffer(eb);
5055 static int release_extent_buffer(struct extent_buffer *eb)
5057 lockdep_assert_held(&eb->refs_lock);
5059 WARN_ON(atomic_read(&eb->refs) == 0);
5060 if (atomic_dec_and_test(&eb->refs)) {
5061 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5062 struct btrfs_fs_info *fs_info = eb->fs_info;
5064 spin_unlock(&eb->refs_lock);
5066 spin_lock(&fs_info->buffer_lock);
5067 radix_tree_delete(&fs_info->buffer_radix,
5068 eb->start >> PAGE_SHIFT);
5069 spin_unlock(&fs_info->buffer_lock);
5071 spin_unlock(&eb->refs_lock);
5074 /* Should be safe to release our pages at this point */
5075 btrfs_release_extent_buffer_pages(eb);
5076 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5077 if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))) {
5078 __free_extent_buffer(eb);
5082 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5085 spin_unlock(&eb->refs_lock);
5090 void free_extent_buffer(struct extent_buffer *eb)
5098 refs = atomic_read(&eb->refs);
5101 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5106 spin_lock(&eb->refs_lock);
5107 if (atomic_read(&eb->refs) == 2 &&
5108 test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))
5109 atomic_dec(&eb->refs);
5111 if (atomic_read(&eb->refs) == 2 &&
5112 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5113 !extent_buffer_under_io(eb) &&
5114 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5115 atomic_dec(&eb->refs);
5118 * I know this is terrible, but it's temporary until we stop tracking
5119 * the uptodate bits and such for the extent buffers.
5121 release_extent_buffer(eb);
5124 void free_extent_buffer_stale(struct extent_buffer *eb)
5129 spin_lock(&eb->refs_lock);
5130 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5132 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5133 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5134 atomic_dec(&eb->refs);
5135 release_extent_buffer(eb);
5138 void clear_extent_buffer_dirty(struct extent_buffer *eb)
5144 num_pages = num_extent_pages(eb);
5146 for (i = 0; i < num_pages; i++) {
5147 page = eb->pages[i];
5148 if (!PageDirty(page))
5152 WARN_ON(!PagePrivate(page));
5154 clear_page_dirty_for_io(page);
5155 xa_lock_irq(&page->mapping->i_pages);
5156 if (!PageDirty(page)) {
5157 radix_tree_tag_clear(&page->mapping->i_pages,
5159 PAGECACHE_TAG_DIRTY);
5161 xa_unlock_irq(&page->mapping->i_pages);
5162 ClearPageError(page);
5165 WARN_ON(atomic_read(&eb->refs) == 0);
5168 int set_extent_buffer_dirty(struct extent_buffer *eb)
5174 check_buffer_tree_ref(eb);
5176 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5178 num_pages = num_extent_pages(eb);
5179 WARN_ON(atomic_read(&eb->refs) == 0);
5180 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5182 for (i = 0; i < num_pages; i++)
5183 set_page_dirty(eb->pages[i]);
5187 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5193 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5194 num_pages = num_extent_pages(eb);
5195 for (i = 0; i < num_pages; i++) {
5196 page = eb->pages[i];
5198 ClearPageUptodate(page);
5202 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5208 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5209 num_pages = num_extent_pages(eb);
5210 for (i = 0; i < num_pages; i++) {
5211 page = eb->pages[i];
5212 SetPageUptodate(page);
5216 int read_extent_buffer_pages(struct extent_io_tree *tree,
5217 struct extent_buffer *eb, int wait, int mirror_num)
5223 int locked_pages = 0;
5224 int all_uptodate = 1;
5226 unsigned long num_reads = 0;
5227 struct bio *bio = NULL;
5228 unsigned long bio_flags = 0;
5230 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5233 num_pages = num_extent_pages(eb);
5234 for (i = 0; i < num_pages; i++) {
5235 page = eb->pages[i];
5236 if (wait == WAIT_NONE) {
5237 if (!trylock_page(page))
5245 * We need to firstly lock all pages to make sure that
5246 * the uptodate bit of our pages won't be affected by
5247 * clear_extent_buffer_uptodate().
5249 for (i = 0; i < num_pages; i++) {
5250 page = eb->pages[i];
5251 if (!PageUptodate(page)) {
5258 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5262 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5263 eb->read_mirror = 0;
5264 atomic_set(&eb->io_pages, num_reads);
5265 for (i = 0; i < num_pages; i++) {
5266 page = eb->pages[i];
5268 if (!PageUptodate(page)) {
5270 atomic_dec(&eb->io_pages);
5275 ClearPageError(page);
5276 err = __extent_read_full_page(tree, page,
5277 btree_get_extent, &bio,
5278 mirror_num, &bio_flags,
5283 * We use &bio in above __extent_read_full_page,
5284 * so we ensure that if it returns error, the
5285 * current page fails to add itself to bio and
5286 * it's been unlocked.
5288 * We must dec io_pages by ourselves.
5290 atomic_dec(&eb->io_pages);
5298 err = submit_one_bio(bio, mirror_num, bio_flags);
5303 if (ret || wait != WAIT_COMPLETE)
5306 for (i = 0; i < num_pages; i++) {
5307 page = eb->pages[i];
5308 wait_on_page_locked(page);
5309 if (!PageUptodate(page))
5316 while (locked_pages > 0) {
5318 page = eb->pages[locked_pages];
5324 void read_extent_buffer(const struct extent_buffer *eb, void *dstv,
5325 unsigned long start, unsigned long len)
5331 char *dst = (char *)dstv;
5332 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5333 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5335 if (start + len > eb->len) {
5336 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5337 eb->start, eb->len, start, len);
5338 memset(dst, 0, len);
5342 offset = (start_offset + start) & (PAGE_SIZE - 1);
5345 page = eb->pages[i];
5347 cur = min(len, (PAGE_SIZE - offset));
5348 kaddr = page_address(page);
5349 memcpy(dst, kaddr + offset, cur);
5358 int read_extent_buffer_to_user(const struct extent_buffer *eb,
5360 unsigned long start, unsigned long len)
5366 char __user *dst = (char __user *)dstv;
5367 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5368 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5371 WARN_ON(start > eb->len);
5372 WARN_ON(start + len > eb->start + eb->len);
5374 offset = (start_offset + start) & (PAGE_SIZE - 1);
5377 page = eb->pages[i];
5379 cur = min(len, (PAGE_SIZE - offset));
5380 kaddr = page_address(page);
5381 if (copy_to_user(dst, kaddr + offset, cur)) {
5396 * return 0 if the item is found within a page.
5397 * return 1 if the item spans two pages.
5398 * return -EINVAL otherwise.
5400 int map_private_extent_buffer(const struct extent_buffer *eb,
5401 unsigned long start, unsigned long min_len,
5402 char **map, unsigned long *map_start,
5403 unsigned long *map_len)
5405 size_t offset = start & (PAGE_SIZE - 1);
5408 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5409 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5410 unsigned long end_i = (start_offset + start + min_len - 1) >>
5413 if (start + min_len > eb->len) {
5414 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5415 eb->start, eb->len, start, min_len);
5423 offset = start_offset;
5427 *map_start = ((u64)i << PAGE_SHIFT) - start_offset;
5431 kaddr = page_address(p);
5432 *map = kaddr + offset;
5433 *map_len = PAGE_SIZE - offset;
5437 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
5438 unsigned long start, unsigned long len)
5444 char *ptr = (char *)ptrv;
5445 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5446 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5449 WARN_ON(start > eb->len);
5450 WARN_ON(start + len > eb->start + eb->len);
5452 offset = (start_offset + start) & (PAGE_SIZE - 1);
5455 page = eb->pages[i];
5457 cur = min(len, (PAGE_SIZE - offset));
5459 kaddr = page_address(page);
5460 ret = memcmp(ptr, kaddr + offset, cur);
5472 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
5477 WARN_ON(!PageUptodate(eb->pages[0]));
5478 kaddr = page_address(eb->pages[0]);
5479 memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
5483 void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)
5487 WARN_ON(!PageUptodate(eb->pages[0]));
5488 kaddr = page_address(eb->pages[0]);
5489 memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
5493 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
5494 unsigned long start, unsigned long len)
5500 char *src = (char *)srcv;
5501 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5502 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5504 WARN_ON(start > eb->len);
5505 WARN_ON(start + len > eb->start + eb->len);
5507 offset = (start_offset + start) & (PAGE_SIZE - 1);
5510 page = eb->pages[i];
5511 WARN_ON(!PageUptodate(page));
5513 cur = min(len, PAGE_SIZE - offset);
5514 kaddr = page_address(page);
5515 memcpy(kaddr + offset, src, cur);
5524 void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
5531 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5532 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5534 WARN_ON(start > eb->len);
5535 WARN_ON(start + len > eb->start + eb->len);
5537 offset = (start_offset + start) & (PAGE_SIZE - 1);
5540 page = eb->pages[i];
5541 WARN_ON(!PageUptodate(page));
5543 cur = min(len, PAGE_SIZE - offset);
5544 kaddr = page_address(page);
5545 memset(kaddr + offset, 0, cur);
5553 void copy_extent_buffer_full(struct extent_buffer *dst,
5554 struct extent_buffer *src)
5559 ASSERT(dst->len == src->len);
5561 num_pages = num_extent_pages(dst);
5562 for (i = 0; i < num_pages; i++)
5563 copy_page(page_address(dst->pages[i]),
5564 page_address(src->pages[i]));
5567 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5568 unsigned long dst_offset, unsigned long src_offset,
5571 u64 dst_len = dst->len;
5576 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5577 unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
5579 WARN_ON(src->len != dst_len);
5581 offset = (start_offset + dst_offset) &
5585 page = dst->pages[i];
5586 WARN_ON(!PageUptodate(page));
5588 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5590 kaddr = page_address(page);
5591 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5601 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5603 * @eb: the extent buffer
5604 * @start: offset of the bitmap item in the extent buffer
5606 * @page_index: return index of the page in the extent buffer that contains the
5608 * @page_offset: return offset into the page given by page_index
5610 * This helper hides the ugliness of finding the byte in an extent buffer which
5611 * contains a given bit.
5613 static inline void eb_bitmap_offset(struct extent_buffer *eb,
5614 unsigned long start, unsigned long nr,
5615 unsigned long *page_index,
5616 size_t *page_offset)
5618 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5619 size_t byte_offset = BIT_BYTE(nr);
5623 * The byte we want is the offset of the extent buffer + the offset of
5624 * the bitmap item in the extent buffer + the offset of the byte in the
5627 offset = start_offset + start + byte_offset;
5629 *page_index = offset >> PAGE_SHIFT;
5630 *page_offset = offset & (PAGE_SIZE - 1);
5634 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5635 * @eb: the extent buffer
5636 * @start: offset of the bitmap item in the extent buffer
5637 * @nr: bit number to test
5639 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
5647 eb_bitmap_offset(eb, start, nr, &i, &offset);
5648 page = eb->pages[i];
5649 WARN_ON(!PageUptodate(page));
5650 kaddr = page_address(page);
5651 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5655 * extent_buffer_bitmap_set - set an area of a bitmap
5656 * @eb: the extent buffer
5657 * @start: offset of the bitmap item in the extent buffer
5658 * @pos: bit number of the first bit
5659 * @len: number of bits to set
5661 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
5662 unsigned long pos, unsigned long len)
5668 const unsigned int size = pos + len;
5669 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5670 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5672 eb_bitmap_offset(eb, start, pos, &i, &offset);
5673 page = eb->pages[i];
5674 WARN_ON(!PageUptodate(page));
5675 kaddr = page_address(page);
5677 while (len >= bits_to_set) {
5678 kaddr[offset] |= mask_to_set;
5680 bits_to_set = BITS_PER_BYTE;
5682 if (++offset >= PAGE_SIZE && len > 0) {
5684 page = eb->pages[++i];
5685 WARN_ON(!PageUptodate(page));
5686 kaddr = page_address(page);
5690 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5691 kaddr[offset] |= mask_to_set;
5697 * extent_buffer_bitmap_clear - clear an area of a bitmap
5698 * @eb: the extent buffer
5699 * @start: offset of the bitmap item in the extent buffer
5700 * @pos: bit number of the first bit
5701 * @len: number of bits to clear
5703 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
5704 unsigned long pos, unsigned long len)
5710 const unsigned int size = pos + len;
5711 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5712 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5714 eb_bitmap_offset(eb, start, pos, &i, &offset);
5715 page = eb->pages[i];
5716 WARN_ON(!PageUptodate(page));
5717 kaddr = page_address(page);
5719 while (len >= bits_to_clear) {
5720 kaddr[offset] &= ~mask_to_clear;
5721 len -= bits_to_clear;
5722 bits_to_clear = BITS_PER_BYTE;
5724 if (++offset >= PAGE_SIZE && len > 0) {
5726 page = eb->pages[++i];
5727 WARN_ON(!PageUptodate(page));
5728 kaddr = page_address(page);
5732 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5733 kaddr[offset] &= ~mask_to_clear;
5737 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5739 unsigned long distance = (src > dst) ? src - dst : dst - src;
5740 return distance < len;
5743 static void copy_pages(struct page *dst_page, struct page *src_page,
5744 unsigned long dst_off, unsigned long src_off,
5747 char *dst_kaddr = page_address(dst_page);
5749 int must_memmove = 0;
5751 if (dst_page != src_page) {
5752 src_kaddr = page_address(src_page);
5754 src_kaddr = dst_kaddr;
5755 if (areas_overlap(src_off, dst_off, len))
5760 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5762 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5765 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5766 unsigned long src_offset, unsigned long len)
5768 struct btrfs_fs_info *fs_info = dst->fs_info;
5770 size_t dst_off_in_page;
5771 size_t src_off_in_page;
5772 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5773 unsigned long dst_i;
5774 unsigned long src_i;
5776 if (src_offset + len > dst->len) {
5778 "memmove bogus src_offset %lu move len %lu dst len %lu",
5779 src_offset, len, dst->len);
5782 if (dst_offset + len > dst->len) {
5784 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5785 dst_offset, len, dst->len);
5790 dst_off_in_page = (start_offset + dst_offset) &
5792 src_off_in_page = (start_offset + src_offset) &
5795 dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
5796 src_i = (start_offset + src_offset) >> PAGE_SHIFT;
5798 cur = min(len, (unsigned long)(PAGE_SIZE -
5800 cur = min_t(unsigned long, cur,
5801 (unsigned long)(PAGE_SIZE - dst_off_in_page));
5803 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5804 dst_off_in_page, src_off_in_page, cur);
5812 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5813 unsigned long src_offset, unsigned long len)
5815 struct btrfs_fs_info *fs_info = dst->fs_info;
5817 size_t dst_off_in_page;
5818 size_t src_off_in_page;
5819 unsigned long dst_end = dst_offset + len - 1;
5820 unsigned long src_end = src_offset + len - 1;
5821 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5822 unsigned long dst_i;
5823 unsigned long src_i;
5825 if (src_offset + len > dst->len) {
5827 "memmove bogus src_offset %lu move len %lu len %lu",
5828 src_offset, len, dst->len);
5831 if (dst_offset + len > dst->len) {
5833 "memmove bogus dst_offset %lu move len %lu len %lu",
5834 dst_offset, len, dst->len);
5837 if (dst_offset < src_offset) {
5838 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5842 dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
5843 src_i = (start_offset + src_end) >> PAGE_SHIFT;
5845 dst_off_in_page = (start_offset + dst_end) &
5847 src_off_in_page = (start_offset + src_end) &
5850 cur = min_t(unsigned long, len, src_off_in_page + 1);
5851 cur = min(cur, dst_off_in_page + 1);
5852 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5853 dst_off_in_page - cur + 1,
5854 src_off_in_page - cur + 1, cur);
5862 int try_release_extent_buffer(struct page *page)
5864 struct extent_buffer *eb;
5867 * We need to make sure nobody is attaching this page to an eb right
5870 spin_lock(&page->mapping->private_lock);
5871 if (!PagePrivate(page)) {
5872 spin_unlock(&page->mapping->private_lock);
5876 eb = (struct extent_buffer *)page->private;
5880 * This is a little awful but should be ok, we need to make sure that
5881 * the eb doesn't disappear out from under us while we're looking at
5884 spin_lock(&eb->refs_lock);
5885 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5886 spin_unlock(&eb->refs_lock);
5887 spin_unlock(&page->mapping->private_lock);
5890 spin_unlock(&page->mapping->private_lock);
5893 * If tree ref isn't set then we know the ref on this eb is a real ref,
5894 * so just return, this page will likely be freed soon anyway.
5896 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5897 spin_unlock(&eb->refs_lock);
5901 return release_extent_buffer(eb);