1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/spinlock.h>
8 #include <linux/blkdev.h>
9 #include <linux/swap.h>
10 #include <linux/writeback.h>
11 #include <linux/pagevec.h>
12 #include <linux/prefetch.h>
13 #include <linux/cleancache.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
17 #include "btrfs_inode.h"
19 #include "check-integrity.h"
21 #include "rcu-string.h"
23 #include "transaction.h"
25 static struct kmem_cache *extent_state_cache;
26 static struct kmem_cache *extent_buffer_cache;
27 static struct bio_set *btrfs_bioset;
29 static inline bool extent_state_in_tree(const struct extent_state *state)
31 return !RB_EMPTY_NODE(&state->rb_node);
34 #ifdef CONFIG_BTRFS_DEBUG
35 static LIST_HEAD(buffers);
36 static LIST_HEAD(states);
38 static DEFINE_SPINLOCK(leak_lock);
41 void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
45 spin_lock_irqsave(&leak_lock, flags);
47 spin_unlock_irqrestore(&leak_lock, flags);
51 void btrfs_leak_debug_del(struct list_head *entry)
55 spin_lock_irqsave(&leak_lock, flags);
57 spin_unlock_irqrestore(&leak_lock, flags);
61 void btrfs_leak_debug_check(void)
63 struct extent_state *state;
64 struct extent_buffer *eb;
66 while (!list_empty(&states)) {
67 state = list_entry(states.next, struct extent_state, leak_list);
68 pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
69 state->start, state->end, state->state,
70 extent_state_in_tree(state),
71 atomic_read(&state->refs));
72 list_del(&state->leak_list);
73 kmem_cache_free(extent_state_cache, state);
76 while (!list_empty(&buffers)) {
77 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
78 pr_err("BTRFS: buffer leak start %llu len %lu refs %d\n",
79 eb->start, eb->len, atomic_read(&eb->refs));
80 list_del(&eb->leak_list);
81 kmem_cache_free(extent_buffer_cache, eb);
85 #define btrfs_debug_check_extent_io_range(tree, start, end) \
86 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
87 static inline void __btrfs_debug_check_extent_io_range(const char *caller,
88 struct extent_io_tree *tree, u64 start, u64 end)
96 inode = tree->mapping->host;
97 isize = i_size_read(inode);
98 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
99 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
100 "%s: ino %llu isize %llu odd range [%llu,%llu]",
101 caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
105 #define btrfs_leak_debug_add(new, head) do {} while (0)
106 #define btrfs_leak_debug_del(entry) do {} while (0)
107 #define btrfs_leak_debug_check() do {} while (0)
108 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
111 #define BUFFER_LRU_MAX 64
116 struct rb_node rb_node;
119 struct extent_page_data {
121 struct extent_io_tree *tree;
122 get_extent_t *get_extent;
123 unsigned long bio_flags;
125 /* tells writepage not to lock the state bits for this range
126 * it still does the unlocking
128 unsigned int extent_locked:1;
130 /* tells the submit_bio code to use REQ_SYNC */
131 unsigned int sync_io:1;
134 static void add_extent_changeset(struct extent_state *state, unsigned bits,
135 struct extent_changeset *changeset,
142 if (set && (state->state & bits) == bits)
144 if (!set && (state->state & bits) == 0)
146 changeset->bytes_changed += state->end - state->start + 1;
147 ret = ulist_add(&changeset->range_changed, state->start, state->end,
153 static noinline void flush_write_bio(void *data);
154 static inline struct btrfs_fs_info *
155 tree_fs_info(struct extent_io_tree *tree)
159 return btrfs_sb(tree->mapping->host->i_sb);
162 int __init extent_io_init(void)
164 extent_state_cache = kmem_cache_create("btrfs_extent_state",
165 sizeof(struct extent_state), 0,
166 SLAB_MEM_SPREAD, NULL);
167 if (!extent_state_cache)
170 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
171 sizeof(struct extent_buffer), 0,
172 SLAB_MEM_SPREAD, NULL);
173 if (!extent_buffer_cache)
174 goto free_state_cache;
176 btrfs_bioset = bioset_create(BIO_POOL_SIZE,
177 offsetof(struct btrfs_io_bio, bio));
179 goto free_buffer_cache;
181 if (bioset_integrity_create(btrfs_bioset, BIO_POOL_SIZE))
187 bioset_free(btrfs_bioset);
191 kmem_cache_destroy(extent_buffer_cache);
192 extent_buffer_cache = NULL;
195 kmem_cache_destroy(extent_state_cache);
196 extent_state_cache = NULL;
200 void extent_io_exit(void)
202 btrfs_leak_debug_check();
205 * Make sure all delayed rcu free are flushed before we
209 kmem_cache_destroy(extent_state_cache);
210 kmem_cache_destroy(extent_buffer_cache);
212 bioset_free(btrfs_bioset);
215 void extent_io_tree_init(struct extent_io_tree *tree,
216 struct address_space *mapping)
218 tree->state = RB_ROOT;
220 tree->dirty_bytes = 0;
221 spin_lock_init(&tree->lock);
222 tree->mapping = mapping;
225 static struct extent_state *alloc_extent_state(gfp_t mask)
227 struct extent_state *state;
230 * The given mask might be not appropriate for the slab allocator,
231 * drop the unsupported bits
233 mask &= ~(__GFP_DMA32|__GFP_HIGHMEM);
234 state = kmem_cache_alloc(extent_state_cache, mask);
238 state->failrec = NULL;
239 RB_CLEAR_NODE(&state->rb_node);
240 btrfs_leak_debug_add(&state->leak_list, &states);
241 atomic_set(&state->refs, 1);
242 init_waitqueue_head(&state->wq);
243 trace_alloc_extent_state(state, mask, _RET_IP_);
247 void free_extent_state(struct extent_state *state)
251 if (atomic_dec_and_test(&state->refs)) {
252 WARN_ON(extent_state_in_tree(state));
253 btrfs_leak_debug_del(&state->leak_list);
254 trace_free_extent_state(state, _RET_IP_);
255 kmem_cache_free(extent_state_cache, state);
259 static struct rb_node *tree_insert(struct rb_root *root,
260 struct rb_node *search_start,
262 struct rb_node *node,
263 struct rb_node ***p_in,
264 struct rb_node **parent_in)
267 struct rb_node *parent = NULL;
268 struct tree_entry *entry;
270 if (p_in && parent_in) {
276 p = search_start ? &search_start : &root->rb_node;
279 entry = rb_entry(parent, struct tree_entry, rb_node);
281 if (offset < entry->start)
283 else if (offset > entry->end)
290 rb_link_node(node, parent, p);
291 rb_insert_color(node, root);
295 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
296 struct rb_node **prev_ret,
297 struct rb_node **next_ret,
298 struct rb_node ***p_ret,
299 struct rb_node **parent_ret)
301 struct rb_root *root = &tree->state;
302 struct rb_node **n = &root->rb_node;
303 struct rb_node *prev = NULL;
304 struct rb_node *orig_prev = NULL;
305 struct tree_entry *entry;
306 struct tree_entry *prev_entry = NULL;
310 entry = rb_entry(prev, struct tree_entry, rb_node);
313 if (offset < entry->start)
315 else if (offset > entry->end)
328 while (prev && offset > prev_entry->end) {
329 prev = rb_next(prev);
330 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
337 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
338 while (prev && offset < prev_entry->start) {
339 prev = rb_prev(prev);
340 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
347 static inline struct rb_node *
348 tree_search_for_insert(struct extent_io_tree *tree,
350 struct rb_node ***p_ret,
351 struct rb_node **parent_ret)
353 struct rb_node *prev = NULL;
356 ret = __etree_search(tree, offset, &prev, NULL, p_ret, parent_ret);
362 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
365 return tree_search_for_insert(tree, offset, NULL, NULL);
368 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
369 struct extent_state *other)
371 if (tree->ops && tree->ops->merge_extent_hook)
372 tree->ops->merge_extent_hook(tree->mapping->host, new,
377 * utility function to look for merge candidates inside a given range.
378 * Any extents with matching state are merged together into a single
379 * extent in the tree. Extents with EXTENT_IO in their state field
380 * are not merged because the end_io handlers need to be able to do
381 * operations on them without sleeping (or doing allocations/splits).
383 * This should be called with the tree lock held.
385 static void merge_state(struct extent_io_tree *tree,
386 struct extent_state *state)
388 struct extent_state *other;
389 struct rb_node *other_node;
391 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
394 other_node = rb_prev(&state->rb_node);
396 other = rb_entry(other_node, struct extent_state, rb_node);
397 if (other->end == state->start - 1 &&
398 other->state == state->state) {
399 merge_cb(tree, state, other);
400 state->start = other->start;
401 rb_erase(&other->rb_node, &tree->state);
402 RB_CLEAR_NODE(&other->rb_node);
403 free_extent_state(other);
406 other_node = rb_next(&state->rb_node);
408 other = rb_entry(other_node, struct extent_state, rb_node);
409 if (other->start == state->end + 1 &&
410 other->state == state->state) {
411 merge_cb(tree, state, other);
412 state->end = other->end;
413 rb_erase(&other->rb_node, &tree->state);
414 RB_CLEAR_NODE(&other->rb_node);
415 free_extent_state(other);
420 static void set_state_cb(struct extent_io_tree *tree,
421 struct extent_state *state, unsigned *bits)
423 if (tree->ops && tree->ops->set_bit_hook)
424 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
427 static void clear_state_cb(struct extent_io_tree *tree,
428 struct extent_state *state, unsigned *bits)
430 if (tree->ops && tree->ops->clear_bit_hook)
431 tree->ops->clear_bit_hook(BTRFS_I(tree->mapping->host),
435 static void set_state_bits(struct extent_io_tree *tree,
436 struct extent_state *state, unsigned *bits,
437 struct extent_changeset *changeset);
440 * insert an extent_state struct into the tree. 'bits' are set on the
441 * struct before it is inserted.
443 * This may return -EEXIST if the extent is already there, in which case the
444 * state struct is freed.
446 * The tree lock is not taken internally. This is a utility function and
447 * probably isn't what you want to call (see set/clear_extent_bit).
449 static int insert_state(struct extent_io_tree *tree,
450 struct extent_state *state, u64 start, u64 end,
452 struct rb_node **parent,
453 unsigned *bits, struct extent_changeset *changeset)
455 struct rb_node *node;
458 WARN(1, KERN_ERR "BTRFS: end < start %llu %llu\n",
460 state->start = start;
463 set_state_bits(tree, state, bits, changeset);
465 node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
467 struct extent_state *found;
468 found = rb_entry(node, struct extent_state, rb_node);
469 pr_err("BTRFS: found node %llu %llu on insert of %llu %llu\n",
470 found->start, found->end, start, end);
473 merge_state(tree, state);
477 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
480 if (tree->ops && tree->ops->split_extent_hook)
481 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
485 * split a given extent state struct in two, inserting the preallocated
486 * struct 'prealloc' as the newly created second half. 'split' indicates an
487 * offset inside 'orig' where it should be split.
490 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
491 * are two extent state structs in the tree:
492 * prealloc: [orig->start, split - 1]
493 * orig: [ split, orig->end ]
495 * The tree locks are not taken by this function. They need to be held
498 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
499 struct extent_state *prealloc, u64 split)
501 struct rb_node *node;
503 split_cb(tree, orig, split);
505 prealloc->start = orig->start;
506 prealloc->end = split - 1;
507 prealloc->state = orig->state;
510 node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
511 &prealloc->rb_node, NULL, NULL);
513 free_extent_state(prealloc);
519 static struct extent_state *next_state(struct extent_state *state)
521 struct rb_node *next = rb_next(&state->rb_node);
523 return rb_entry(next, struct extent_state, rb_node);
529 * utility function to clear some bits in an extent state struct.
530 * it will optionally wake up any one waiting on this state (wake == 1).
532 * If no bits are set on the state struct after clearing things, the
533 * struct is freed and removed from the tree
535 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
536 struct extent_state *state,
537 unsigned *bits, int wake,
538 struct extent_changeset *changeset)
540 struct extent_state *next;
541 unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
543 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
544 u64 range = state->end - state->start + 1;
545 WARN_ON(range > tree->dirty_bytes);
546 tree->dirty_bytes -= range;
548 clear_state_cb(tree, state, bits);
549 add_extent_changeset(state, bits_to_clear, changeset, 0);
550 state->state &= ~bits_to_clear;
553 if (state->state == 0) {
554 next = next_state(state);
555 if (extent_state_in_tree(state)) {
556 rb_erase(&state->rb_node, &tree->state);
557 RB_CLEAR_NODE(&state->rb_node);
558 free_extent_state(state);
563 merge_state(tree, state);
564 next = next_state(state);
569 static struct extent_state *
570 alloc_extent_state_atomic(struct extent_state *prealloc)
573 prealloc = alloc_extent_state(GFP_ATOMIC);
578 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
580 btrfs_panic(tree_fs_info(tree), err,
581 "Locking error: Extent tree was modified by another thread while locked.");
585 * clear some bits on a range in the tree. This may require splitting
586 * or inserting elements in the tree, so the gfp mask is used to
587 * indicate which allocations or sleeping are allowed.
589 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
590 * the given range from the tree regardless of state (ie for truncate).
592 * the range [start, end] is inclusive.
594 * This takes the tree lock, and returns 0 on success and < 0 on error.
596 static int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
597 unsigned bits, int wake, int delete,
598 struct extent_state **cached_state,
599 gfp_t mask, struct extent_changeset *changeset)
601 struct extent_state *state;
602 struct extent_state *cached;
603 struct extent_state *prealloc = NULL;
604 struct rb_node *node;
609 btrfs_debug_check_extent_io_range(tree, start, end);
611 if (bits & EXTENT_DELALLOC)
612 bits |= EXTENT_NORESERVE;
615 bits |= ~EXTENT_CTLBITS;
616 bits |= EXTENT_FIRST_DELALLOC;
618 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
621 if (!prealloc && gfpflags_allow_blocking(mask)) {
623 * Don't care for allocation failure here because we might end
624 * up not needing the pre-allocated extent state at all, which
625 * is the case if we only have in the tree extent states that
626 * cover our input range and don't cover too any other range.
627 * If we end up needing a new extent state we allocate it later.
629 prealloc = alloc_extent_state(mask);
632 spin_lock(&tree->lock);
634 cached = *cached_state;
637 *cached_state = NULL;
641 if (cached && extent_state_in_tree(cached) &&
642 cached->start <= start && cached->end > start) {
644 atomic_dec(&cached->refs);
649 free_extent_state(cached);
652 * this search will find the extents that end after
655 node = tree_search(tree, start);
658 state = rb_entry(node, struct extent_state, rb_node);
660 if (state->start > end)
662 WARN_ON(state->end < start);
663 last_end = state->end;
665 /* the state doesn't have the wanted bits, go ahead */
666 if (!(state->state & bits)) {
667 state = next_state(state);
672 * | ---- desired range ---- |
674 * | ------------- state -------------- |
676 * We need to split the extent we found, and may flip
677 * bits on second half.
679 * If the extent we found extends past our range, we
680 * just split and search again. It'll get split again
681 * the next time though.
683 * If the extent we found is inside our range, we clear
684 * the desired bit on it.
687 if (state->start < start) {
688 prealloc = alloc_extent_state_atomic(prealloc);
690 err = split_state(tree, state, prealloc, start);
692 extent_io_tree_panic(tree, err);
697 if (state->end <= end) {
698 state = clear_state_bit(tree, state, &bits, wake,
705 * | ---- desired range ---- |
707 * We need to split the extent, and clear the bit
710 if (state->start <= end && state->end > end) {
711 prealloc = alloc_extent_state_atomic(prealloc);
713 err = split_state(tree, state, prealloc, end + 1);
715 extent_io_tree_panic(tree, err);
720 clear_state_bit(tree, prealloc, &bits, wake, changeset);
726 state = clear_state_bit(tree, state, &bits, wake, changeset);
728 if (last_end == (u64)-1)
730 start = last_end + 1;
731 if (start <= end && state && !need_resched())
737 spin_unlock(&tree->lock);
738 if (gfpflags_allow_blocking(mask))
743 spin_unlock(&tree->lock);
745 free_extent_state(prealloc);
751 static void wait_on_state(struct extent_io_tree *tree,
752 struct extent_state *state)
753 __releases(tree->lock)
754 __acquires(tree->lock)
757 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
758 spin_unlock(&tree->lock);
760 spin_lock(&tree->lock);
761 finish_wait(&state->wq, &wait);
765 * waits for one or more bits to clear on a range in the state tree.
766 * The range [start, end] is inclusive.
767 * The tree lock is taken by this function
769 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
772 struct extent_state *state;
773 struct rb_node *node;
775 btrfs_debug_check_extent_io_range(tree, start, end);
777 spin_lock(&tree->lock);
781 * this search will find all the extents that end after
784 node = tree_search(tree, start);
789 state = rb_entry(node, struct extent_state, rb_node);
791 if (state->start > end)
794 if (state->state & bits) {
795 start = state->start;
796 atomic_inc(&state->refs);
797 wait_on_state(tree, state);
798 free_extent_state(state);
801 start = state->end + 1;
806 if (!cond_resched_lock(&tree->lock)) {
807 node = rb_next(node);
812 spin_unlock(&tree->lock);
815 static void set_state_bits(struct extent_io_tree *tree,
816 struct extent_state *state,
817 unsigned *bits, struct extent_changeset *changeset)
819 unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
821 set_state_cb(tree, state, bits);
822 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
823 u64 range = state->end - state->start + 1;
824 tree->dirty_bytes += range;
826 add_extent_changeset(state, bits_to_set, changeset, 1);
827 state->state |= bits_to_set;
830 static void cache_state_if_flags(struct extent_state *state,
831 struct extent_state **cached_ptr,
834 if (cached_ptr && !(*cached_ptr)) {
835 if (!flags || (state->state & flags)) {
837 atomic_inc(&state->refs);
842 static void cache_state(struct extent_state *state,
843 struct extent_state **cached_ptr)
845 return cache_state_if_flags(state, cached_ptr,
846 EXTENT_IOBITS | EXTENT_BOUNDARY);
850 * set some bits on a range in the tree. This may require allocations or
851 * sleeping, so the gfp mask is used to indicate what is allowed.
853 * If any of the exclusive bits are set, this will fail with -EEXIST if some
854 * part of the range already has the desired bits set. The start of the
855 * existing range is returned in failed_start in this case.
857 * [start, end] is inclusive This takes the tree lock.
860 static int __must_check
861 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
862 unsigned bits, unsigned exclusive_bits,
863 u64 *failed_start, struct extent_state **cached_state,
864 gfp_t mask, struct extent_changeset *changeset)
866 struct extent_state *state;
867 struct extent_state *prealloc = NULL;
868 struct rb_node *node;
870 struct rb_node *parent;
875 btrfs_debug_check_extent_io_range(tree, start, end);
877 bits |= EXTENT_FIRST_DELALLOC;
879 if (!prealloc && gfpflags_allow_blocking(mask)) {
881 * Don't care for allocation failure here because we might end
882 * up not needing the pre-allocated extent state at all, which
883 * is the case if we only have in the tree extent states that
884 * cover our input range and don't cover too any other range.
885 * If we end up needing a new extent state we allocate it later.
887 prealloc = alloc_extent_state(mask);
890 spin_lock(&tree->lock);
891 if (cached_state && *cached_state) {
892 state = *cached_state;
893 if (state->start <= start && state->end > start &&
894 extent_state_in_tree(state)) {
895 node = &state->rb_node;
900 * this search will find all the extents that end after
903 node = tree_search_for_insert(tree, start, &p, &parent);
905 prealloc = alloc_extent_state_atomic(prealloc);
907 err = insert_state(tree, prealloc, start, end,
908 &p, &parent, &bits, changeset);
910 extent_io_tree_panic(tree, err);
912 cache_state(prealloc, cached_state);
916 state = rb_entry(node, struct extent_state, rb_node);
918 last_start = state->start;
919 last_end = state->end;
922 * | ---- desired range ---- |
925 * Just lock what we found and keep going
927 if (state->start == start && state->end <= end) {
928 if (state->state & exclusive_bits) {
929 *failed_start = state->start;
934 set_state_bits(tree, state, &bits, changeset);
935 cache_state(state, cached_state);
936 merge_state(tree, state);
937 if (last_end == (u64)-1)
939 start = last_end + 1;
940 state = next_state(state);
941 if (start < end && state && state->start == start &&
948 * | ---- desired range ---- |
951 * | ------------- state -------------- |
953 * We need to split the extent we found, and may flip bits on
956 * If the extent we found extends past our
957 * range, we just split and search again. It'll get split
958 * again the next time though.
960 * If the extent we found is inside our range, we set the
963 if (state->start < start) {
964 if (state->state & exclusive_bits) {
965 *failed_start = start;
970 prealloc = alloc_extent_state_atomic(prealloc);
972 err = split_state(tree, state, prealloc, start);
974 extent_io_tree_panic(tree, err);
979 if (state->end <= end) {
980 set_state_bits(tree, state, &bits, changeset);
981 cache_state(state, cached_state);
982 merge_state(tree, state);
983 if (last_end == (u64)-1)
985 start = last_end + 1;
986 state = next_state(state);
987 if (start < end && state && state->start == start &&
994 * | ---- desired range ---- |
995 * | state | or | state |
997 * There's a hole, we need to insert something in it and
998 * ignore the extent we found.
1000 if (state->start > start) {
1002 if (end < last_start)
1005 this_end = last_start - 1;
1007 prealloc = alloc_extent_state_atomic(prealloc);
1011 * Avoid to free 'prealloc' if it can be merged with
1014 err = insert_state(tree, prealloc, start, this_end,
1015 NULL, NULL, &bits, changeset);
1017 extent_io_tree_panic(tree, err);
1019 cache_state(prealloc, cached_state);
1021 start = this_end + 1;
1025 * | ---- desired range ---- |
1027 * We need to split the extent, and set the bit
1030 if (state->start <= end && state->end > end) {
1031 if (state->state & exclusive_bits) {
1032 *failed_start = start;
1037 prealloc = alloc_extent_state_atomic(prealloc);
1039 err = split_state(tree, state, prealloc, end + 1);
1041 extent_io_tree_panic(tree, err);
1043 set_state_bits(tree, prealloc, &bits, changeset);
1044 cache_state(prealloc, cached_state);
1045 merge_state(tree, prealloc);
1053 spin_unlock(&tree->lock);
1054 if (gfpflags_allow_blocking(mask))
1059 spin_unlock(&tree->lock);
1061 free_extent_state(prealloc);
1067 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1068 unsigned bits, u64 * failed_start,
1069 struct extent_state **cached_state, gfp_t mask)
1071 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
1072 cached_state, mask, NULL);
1077 * convert_extent_bit - convert all bits in a given range from one bit to
1079 * @tree: the io tree to search
1080 * @start: the start offset in bytes
1081 * @end: the end offset in bytes (inclusive)
1082 * @bits: the bits to set in this range
1083 * @clear_bits: the bits to clear in this range
1084 * @cached_state: state that we're going to cache
1086 * This will go through and set bits for the given range. If any states exist
1087 * already in this range they are set with the given bit and cleared of the
1088 * clear_bits. This is only meant to be used by things that are mergeable, ie
1089 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1090 * boundary bits like LOCK.
1092 * All allocations are done with GFP_NOFS.
1094 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1095 unsigned bits, unsigned clear_bits,
1096 struct extent_state **cached_state)
1098 struct extent_state *state;
1099 struct extent_state *prealloc = NULL;
1100 struct rb_node *node;
1102 struct rb_node *parent;
1106 bool first_iteration = true;
1108 btrfs_debug_check_extent_io_range(tree, start, end);
1113 * Best effort, don't worry if extent state allocation fails
1114 * here for the first iteration. We might have a cached state
1115 * that matches exactly the target range, in which case no
1116 * extent state allocations are needed. We'll only know this
1117 * after locking the tree.
1119 prealloc = alloc_extent_state(GFP_NOFS);
1120 if (!prealloc && !first_iteration)
1124 spin_lock(&tree->lock);
1125 if (cached_state && *cached_state) {
1126 state = *cached_state;
1127 if (state->start <= start && state->end > start &&
1128 extent_state_in_tree(state)) {
1129 node = &state->rb_node;
1135 * this search will find all the extents that end after
1138 node = tree_search_for_insert(tree, start, &p, &parent);
1140 prealloc = alloc_extent_state_atomic(prealloc);
1145 err = insert_state(tree, prealloc, start, end,
1146 &p, &parent, &bits, NULL);
1148 extent_io_tree_panic(tree, err);
1149 cache_state(prealloc, cached_state);
1153 state = rb_entry(node, struct extent_state, rb_node);
1155 last_start = state->start;
1156 last_end = state->end;
1159 * | ---- desired range ---- |
1162 * Just lock what we found and keep going
1164 if (state->start == start && state->end <= end) {
1165 set_state_bits(tree, state, &bits, NULL);
1166 cache_state(state, cached_state);
1167 state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
1168 if (last_end == (u64)-1)
1170 start = last_end + 1;
1171 if (start < end && state && state->start == start &&
1178 * | ---- desired range ---- |
1181 * | ------------- state -------------- |
1183 * We need to split the extent we found, and may flip bits on
1186 * If the extent we found extends past our
1187 * range, we just split and search again. It'll get split
1188 * again the next time though.
1190 * If the extent we found is inside our range, we set the
1191 * desired bit on it.
1193 if (state->start < start) {
1194 prealloc = alloc_extent_state_atomic(prealloc);
1199 err = split_state(tree, state, prealloc, start);
1201 extent_io_tree_panic(tree, err);
1205 if (state->end <= end) {
1206 set_state_bits(tree, state, &bits, NULL);
1207 cache_state(state, cached_state);
1208 state = clear_state_bit(tree, state, &clear_bits, 0,
1210 if (last_end == (u64)-1)
1212 start = last_end + 1;
1213 if (start < end && state && state->start == start &&
1220 * | ---- desired range ---- |
1221 * | state | or | state |
1223 * There's a hole, we need to insert something in it and
1224 * ignore the extent we found.
1226 if (state->start > start) {
1228 if (end < last_start)
1231 this_end = last_start - 1;
1233 prealloc = alloc_extent_state_atomic(prealloc);
1240 * Avoid to free 'prealloc' if it can be merged with
1243 err = insert_state(tree, prealloc, start, this_end,
1244 NULL, NULL, &bits, NULL);
1246 extent_io_tree_panic(tree, err);
1247 cache_state(prealloc, cached_state);
1249 start = this_end + 1;
1253 * | ---- desired range ---- |
1255 * We need to split the extent, and set the bit
1258 if (state->start <= end && state->end > end) {
1259 prealloc = alloc_extent_state_atomic(prealloc);
1265 err = split_state(tree, state, prealloc, end + 1);
1267 extent_io_tree_panic(tree, err);
1269 set_state_bits(tree, prealloc, &bits, NULL);
1270 cache_state(prealloc, cached_state);
1271 clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
1279 spin_unlock(&tree->lock);
1281 first_iteration = false;
1285 spin_unlock(&tree->lock);
1287 free_extent_state(prealloc);
1292 /* wrappers around set/clear extent bit */
1293 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1294 unsigned bits, struct extent_changeset *changeset)
1297 * We don't support EXTENT_LOCKED yet, as current changeset will
1298 * record any bits changed, so for EXTENT_LOCKED case, it will
1299 * either fail with -EEXIST or changeset will record the whole
1302 BUG_ON(bits & EXTENT_LOCKED);
1304 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
1308 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1309 unsigned bits, int wake, int delete,
1310 struct extent_state **cached, gfp_t mask)
1312 return __clear_extent_bit(tree, start, end, bits, wake, delete,
1313 cached, mask, NULL);
1316 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1317 unsigned bits, struct extent_changeset *changeset)
1320 * Don't support EXTENT_LOCKED case, same reason as
1321 * set_record_extent_bits().
1323 BUG_ON(bits & EXTENT_LOCKED);
1325 return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
1330 * either insert or lock state struct between start and end use mask to tell
1331 * us if waiting is desired.
1333 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1334 struct extent_state **cached_state)
1340 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
1341 EXTENT_LOCKED, &failed_start,
1342 cached_state, GFP_NOFS, NULL);
1343 if (err == -EEXIST) {
1344 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1345 start = failed_start;
1348 WARN_ON(start > end);
1353 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1358 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1359 &failed_start, NULL, GFP_NOFS, NULL);
1360 if (err == -EEXIST) {
1361 if (failed_start > start)
1362 clear_extent_bit(tree, start, failed_start - 1,
1363 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
1369 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1371 unsigned long index = start >> PAGE_SHIFT;
1372 unsigned long end_index = end >> PAGE_SHIFT;
1375 while (index <= end_index) {
1376 page = find_get_page(inode->i_mapping, index);
1377 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1378 clear_page_dirty_for_io(page);
1384 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1386 unsigned long index = start >> PAGE_SHIFT;
1387 unsigned long end_index = end >> PAGE_SHIFT;
1390 while (index <= end_index) {
1391 page = find_get_page(inode->i_mapping, index);
1392 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1393 __set_page_dirty_nobuffers(page);
1394 account_page_redirty(page);
1401 * helper function to set both pages and extents in the tree writeback
1403 static void set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1405 unsigned long index = start >> PAGE_SHIFT;
1406 unsigned long end_index = end >> PAGE_SHIFT;
1409 while (index <= end_index) {
1410 page = find_get_page(tree->mapping, index);
1411 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1412 set_page_writeback(page);
1418 /* find the first state struct with 'bits' set after 'start', and
1419 * return it. tree->lock must be held. NULL will returned if
1420 * nothing was found after 'start'
1422 static struct extent_state *
1423 find_first_extent_bit_state(struct extent_io_tree *tree,
1424 u64 start, unsigned bits)
1426 struct rb_node *node;
1427 struct extent_state *state;
1430 * this search will find all the extents that end after
1433 node = tree_search(tree, start);
1438 state = rb_entry(node, struct extent_state, rb_node);
1439 if (state->end >= start && (state->state & bits))
1442 node = rb_next(node);
1451 * find the first offset in the io tree with 'bits' set. zero is
1452 * returned if we find something, and *start_ret and *end_ret are
1453 * set to reflect the state struct that was found.
1455 * If nothing was found, 1 is returned. If found something, return 0.
1457 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1458 u64 *start_ret, u64 *end_ret, unsigned bits,
1459 struct extent_state **cached_state)
1461 struct extent_state *state;
1465 spin_lock(&tree->lock);
1466 if (cached_state && *cached_state) {
1467 state = *cached_state;
1468 if (state->end == start - 1 && extent_state_in_tree(state)) {
1469 n = rb_next(&state->rb_node);
1471 state = rb_entry(n, struct extent_state,
1473 if (state->state & bits)
1477 free_extent_state(*cached_state);
1478 *cached_state = NULL;
1481 free_extent_state(*cached_state);
1482 *cached_state = NULL;
1485 state = find_first_extent_bit_state(tree, start, bits);
1488 cache_state_if_flags(state, cached_state, 0);
1489 *start_ret = state->start;
1490 *end_ret = state->end;
1494 spin_unlock(&tree->lock);
1499 * find a contiguous range of bytes in the file marked as delalloc, not
1500 * more than 'max_bytes'. start and end are used to return the range,
1502 * 1 is returned if we find something, 0 if nothing was in the tree
1504 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1505 u64 *start, u64 *end, u64 max_bytes,
1506 struct extent_state **cached_state)
1508 struct rb_node *node;
1509 struct extent_state *state;
1510 u64 cur_start = *start;
1512 u64 total_bytes = 0;
1514 spin_lock(&tree->lock);
1517 * this search will find all the extents that end after
1520 node = tree_search(tree, cur_start);
1528 state = rb_entry(node, struct extent_state, rb_node);
1529 if (found && (state->start != cur_start ||
1530 (state->state & EXTENT_BOUNDARY))) {
1533 if (!(state->state & EXTENT_DELALLOC)) {
1539 *start = state->start;
1540 *cached_state = state;
1541 atomic_inc(&state->refs);
1545 cur_start = state->end + 1;
1546 node = rb_next(node);
1547 total_bytes += state->end - state->start + 1;
1548 if (total_bytes >= max_bytes)
1554 spin_unlock(&tree->lock);
1558 static int __process_pages_contig(struct address_space *mapping,
1559 struct page *locked_page,
1560 pgoff_t start_index, pgoff_t end_index,
1561 unsigned long page_ops, pgoff_t *index_ret);
1563 static noinline void __unlock_for_delalloc(struct inode *inode,
1564 struct page *locked_page,
1567 unsigned long index = start >> PAGE_SHIFT;
1568 unsigned long end_index = end >> PAGE_SHIFT;
1570 ASSERT(locked_page);
1571 if (index == locked_page->index && end_index == index)
1574 __process_pages_contig(inode->i_mapping, locked_page, index, end_index,
1578 static noinline int lock_delalloc_pages(struct inode *inode,
1579 struct page *locked_page,
1583 unsigned long index = delalloc_start >> PAGE_SHIFT;
1584 unsigned long index_ret = index;
1585 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1588 ASSERT(locked_page);
1589 if (index == locked_page->index && index == end_index)
1592 ret = __process_pages_contig(inode->i_mapping, locked_page, index,
1593 end_index, PAGE_LOCK, &index_ret);
1595 __unlock_for_delalloc(inode, locked_page, delalloc_start,
1596 (u64)index_ret << PAGE_SHIFT);
1601 * find a contiguous range of bytes in the file marked as delalloc, not
1602 * more than 'max_bytes'. start and end are used to return the range,
1604 * 1 is returned if we find something, 0 if nothing was in the tree
1606 STATIC u64 find_lock_delalloc_range(struct inode *inode,
1607 struct extent_io_tree *tree,
1608 struct page *locked_page, u64 *start,
1609 u64 *end, u64 max_bytes)
1614 struct extent_state *cached_state = NULL;
1619 /* step one, find a bunch of delalloc bytes starting at start */
1620 delalloc_start = *start;
1622 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1623 max_bytes, &cached_state);
1624 if (!found || delalloc_end <= *start) {
1625 *start = delalloc_start;
1626 *end = delalloc_end;
1627 free_extent_state(cached_state);
1632 * start comes from the offset of locked_page. We have to lock
1633 * pages in order, so we can't process delalloc bytes before
1636 if (delalloc_start < *start)
1637 delalloc_start = *start;
1640 * make sure to limit the number of pages we try to lock down
1642 if (delalloc_end + 1 - delalloc_start > max_bytes)
1643 delalloc_end = delalloc_start + max_bytes - 1;
1645 /* step two, lock all the pages after the page that has start */
1646 ret = lock_delalloc_pages(inode, locked_page,
1647 delalloc_start, delalloc_end);
1648 if (ret == -EAGAIN) {
1649 /* some of the pages are gone, lets avoid looping by
1650 * shortening the size of the delalloc range we're searching
1652 free_extent_state(cached_state);
1653 cached_state = NULL;
1655 max_bytes = PAGE_SIZE;
1663 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1665 /* step three, lock the state bits for the whole range */
1666 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1668 /* then test to make sure it is all still delalloc */
1669 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1670 EXTENT_DELALLOC, 1, cached_state);
1672 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1673 &cached_state, GFP_NOFS);
1674 __unlock_for_delalloc(inode, locked_page,
1675 delalloc_start, delalloc_end);
1679 free_extent_state(cached_state);
1680 *start = delalloc_start;
1681 *end = delalloc_end;
1686 static int __process_pages_contig(struct address_space *mapping,
1687 struct page *locked_page,
1688 pgoff_t start_index, pgoff_t end_index,
1689 unsigned long page_ops, pgoff_t *index_ret)
1691 unsigned long nr_pages = end_index - start_index + 1;
1692 unsigned long pages_locked = 0;
1693 pgoff_t index = start_index;
1694 struct page *pages[16];
1699 if (page_ops & PAGE_LOCK) {
1700 ASSERT(page_ops == PAGE_LOCK);
1701 ASSERT(index_ret && *index_ret == start_index);
1704 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1705 mapping_set_error(mapping, -EIO);
1707 while (nr_pages > 0) {
1708 ret = find_get_pages_contig(mapping, index,
1709 min_t(unsigned long,
1710 nr_pages, ARRAY_SIZE(pages)), pages);
1713 * Only if we're going to lock these pages,
1714 * can we find nothing at @index.
1716 ASSERT(page_ops & PAGE_LOCK);
1721 for (i = 0; i < ret; i++) {
1722 if (page_ops & PAGE_SET_PRIVATE2)
1723 SetPagePrivate2(pages[i]);
1725 if (pages[i] == locked_page) {
1730 if (page_ops & PAGE_CLEAR_DIRTY)
1731 clear_page_dirty_for_io(pages[i]);
1732 if (page_ops & PAGE_SET_WRITEBACK)
1733 set_page_writeback(pages[i]);
1734 if (page_ops & PAGE_SET_ERROR)
1735 SetPageError(pages[i]);
1736 if (page_ops & PAGE_END_WRITEBACK)
1737 end_page_writeback(pages[i]);
1738 if (page_ops & PAGE_UNLOCK)
1739 unlock_page(pages[i]);
1740 if (page_ops & PAGE_LOCK) {
1741 lock_page(pages[i]);
1742 if (!PageDirty(pages[i]) ||
1743 pages[i]->mapping != mapping) {
1744 unlock_page(pages[i]);
1758 if (err && index_ret)
1759 *index_ret = start_index + pages_locked - 1;
1763 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1764 u64 delalloc_end, struct page *locked_page,
1765 unsigned clear_bits,
1766 unsigned long page_ops)
1768 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0,
1771 __process_pages_contig(inode->i_mapping, locked_page,
1772 start >> PAGE_SHIFT, end >> PAGE_SHIFT,
1777 * count the number of bytes in the tree that have a given bit(s)
1778 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1779 * cached. The total number found is returned.
1781 u64 count_range_bits(struct extent_io_tree *tree,
1782 u64 *start, u64 search_end, u64 max_bytes,
1783 unsigned bits, int contig)
1785 struct rb_node *node;
1786 struct extent_state *state;
1787 u64 cur_start = *start;
1788 u64 total_bytes = 0;
1792 if (WARN_ON(search_end <= cur_start))
1795 spin_lock(&tree->lock);
1796 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1797 total_bytes = tree->dirty_bytes;
1801 * this search will find all the extents that end after
1804 node = tree_search(tree, cur_start);
1809 state = rb_entry(node, struct extent_state, rb_node);
1810 if (state->start > search_end)
1812 if (contig && found && state->start > last + 1)
1814 if (state->end >= cur_start && (state->state & bits) == bits) {
1815 total_bytes += min(search_end, state->end) + 1 -
1816 max(cur_start, state->start);
1817 if (total_bytes >= max_bytes)
1820 *start = max(cur_start, state->start);
1824 } else if (contig && found) {
1827 node = rb_next(node);
1832 spin_unlock(&tree->lock);
1837 * set the private field for a given byte offset in the tree. If there isn't
1838 * an extent_state there already, this does nothing.
1840 static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start,
1841 struct io_failure_record *failrec)
1843 struct rb_node *node;
1844 struct extent_state *state;
1847 spin_lock(&tree->lock);
1849 * this search will find all the extents that end after
1852 node = tree_search(tree, start);
1857 state = rb_entry(node, struct extent_state, rb_node);
1858 if (state->start != start) {
1862 state->failrec = failrec;
1864 spin_unlock(&tree->lock);
1868 static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start,
1869 struct io_failure_record **failrec)
1871 struct rb_node *node;
1872 struct extent_state *state;
1875 spin_lock(&tree->lock);
1877 * this search will find all the extents that end after
1880 node = tree_search(tree, start);
1885 state = rb_entry(node, struct extent_state, rb_node);
1886 if (state->start != start) {
1890 *failrec = state->failrec;
1892 spin_unlock(&tree->lock);
1897 * searches a range in the state tree for a given mask.
1898 * If 'filled' == 1, this returns 1 only if every extent in the tree
1899 * has the bits set. Otherwise, 1 is returned if any bit in the
1900 * range is found set.
1902 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1903 unsigned bits, int filled, struct extent_state *cached)
1905 struct extent_state *state = NULL;
1906 struct rb_node *node;
1909 spin_lock(&tree->lock);
1910 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
1911 cached->end > start)
1912 node = &cached->rb_node;
1914 node = tree_search(tree, start);
1915 while (node && start <= end) {
1916 state = rb_entry(node, struct extent_state, rb_node);
1918 if (filled && state->start > start) {
1923 if (state->start > end)
1926 if (state->state & bits) {
1930 } else if (filled) {
1935 if (state->end == (u64)-1)
1938 start = state->end + 1;
1941 node = rb_next(node);
1948 spin_unlock(&tree->lock);
1953 * helper function to set a given page up to date if all the
1954 * extents in the tree for that page are up to date
1956 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1958 u64 start = page_offset(page);
1959 u64 end = start + PAGE_SIZE - 1;
1960 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1961 SetPageUptodate(page);
1964 int free_io_failure(struct btrfs_inode *inode, struct io_failure_record *rec)
1968 struct extent_io_tree *failure_tree = &inode->io_failure_tree;
1970 set_state_failrec(failure_tree, rec->start, NULL);
1971 ret = clear_extent_bits(failure_tree, rec->start,
1972 rec->start + rec->len - 1,
1973 EXTENT_LOCKED | EXTENT_DIRTY);
1977 ret = clear_extent_bits(&inode->io_tree, rec->start,
1978 rec->start + rec->len - 1,
1988 * this bypasses the standard btrfs submit functions deliberately, as
1989 * the standard behavior is to write all copies in a raid setup. here we only
1990 * want to write the one bad copy. so we do the mapping for ourselves and issue
1991 * submit_bio directly.
1992 * to avoid any synchronization issues, wait for the data after writing, which
1993 * actually prevents the read that triggered the error from finishing.
1994 * currently, there can be no more than two copies of every data bit. thus,
1995 * exactly one rewrite is required.
1997 int repair_io_failure(struct btrfs_inode *inode, u64 start, u64 length,
1998 u64 logical, struct page *page,
1999 unsigned int pg_offset, int mirror_num)
2001 struct btrfs_fs_info *fs_info = inode->root->fs_info;
2003 struct btrfs_device *dev;
2006 struct btrfs_bio *bbio = NULL;
2007 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
2010 ASSERT(!(fs_info->sb->s_flags & MS_RDONLY));
2011 BUG_ON(!mirror_num);
2013 /* we can't repair anything in raid56 yet */
2014 if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num))
2017 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2020 bio->bi_iter.bi_size = 0;
2021 map_length = length;
2024 * Avoid races with device replace and make sure our bbio has devices
2025 * associated to its stripes that don't go away while we are doing the
2026 * read repair operation.
2028 btrfs_bio_counter_inc_blocked(fs_info);
2029 ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
2030 &map_length, &bbio, mirror_num);
2032 btrfs_bio_counter_dec(fs_info);
2036 BUG_ON(mirror_num != bbio->mirror_num);
2037 sector = bbio->stripes[mirror_num-1].physical >> 9;
2038 bio->bi_iter.bi_sector = sector;
2039 dev = bbio->stripes[mirror_num-1].dev;
2040 btrfs_put_bbio(bbio);
2041 if (!dev || !dev->bdev || !dev->writeable) {
2042 btrfs_bio_counter_dec(fs_info);
2046 bio->bi_bdev = dev->bdev;
2047 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
2048 bio_add_page(bio, page, length, pg_offset);
2050 if (btrfsic_submit_bio_wait(bio)) {
2051 /* try to remap that extent elsewhere? */
2052 btrfs_bio_counter_dec(fs_info);
2054 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2058 btrfs_info_rl_in_rcu(fs_info,
2059 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2060 btrfs_ino(inode), start,
2061 rcu_str_deref(dev->name), sector);
2062 btrfs_bio_counter_dec(fs_info);
2067 int repair_eb_io_failure(struct btrfs_fs_info *fs_info,
2068 struct extent_buffer *eb, int mirror_num)
2070 u64 start = eb->start;
2071 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
2074 if (fs_info->sb->s_flags & MS_RDONLY)
2077 for (i = 0; i < num_pages; i++) {
2078 struct page *p = eb->pages[i];
2080 ret = repair_io_failure(BTRFS_I(fs_info->btree_inode), start,
2081 PAGE_SIZE, start, p,
2082 start - page_offset(p), mirror_num);
2092 * each time an IO finishes, we do a fast check in the IO failure tree
2093 * to see if we need to process or clean up an io_failure_record
2095 int clean_io_failure(struct btrfs_inode *inode, u64 start, struct page *page,
2096 unsigned int pg_offset)
2099 struct io_failure_record *failrec;
2100 struct btrfs_fs_info *fs_info = inode->root->fs_info;
2101 struct extent_state *state;
2106 ret = count_range_bits(&inode->io_failure_tree, &private,
2107 (u64)-1, 1, EXTENT_DIRTY, 0);
2111 ret = get_state_failrec(&inode->io_failure_tree, start,
2116 BUG_ON(!failrec->this_mirror);
2118 if (failrec->in_validation) {
2119 /* there was no real error, just free the record */
2120 btrfs_debug(fs_info,
2121 "clean_io_failure: freeing dummy error at %llu",
2125 if (fs_info->sb->s_flags & MS_RDONLY)
2128 spin_lock(&inode->io_tree.lock);
2129 state = find_first_extent_bit_state(&inode->io_tree,
2132 spin_unlock(&inode->io_tree.lock);
2134 if (state && state->start <= failrec->start &&
2135 state->end >= failrec->start + failrec->len - 1) {
2136 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2138 if (num_copies > 1) {
2139 repair_io_failure(inode, start, failrec->len,
2140 failrec->logical, page,
2141 pg_offset, failrec->failed_mirror);
2146 free_io_failure(inode, failrec);
2152 * Can be called when
2153 * - hold extent lock
2154 * - under ordered extent
2155 * - the inode is freeing
2157 void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end)
2159 struct extent_io_tree *failure_tree = &inode->io_failure_tree;
2160 struct io_failure_record *failrec;
2161 struct extent_state *state, *next;
2163 if (RB_EMPTY_ROOT(&failure_tree->state))
2166 spin_lock(&failure_tree->lock);
2167 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2169 if (state->start > end)
2172 ASSERT(state->end <= end);
2174 next = next_state(state);
2176 failrec = state->failrec;
2177 free_extent_state(state);
2182 spin_unlock(&failure_tree->lock);
2185 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2186 struct io_failure_record **failrec_ret)
2188 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2189 struct io_failure_record *failrec;
2190 struct extent_map *em;
2191 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2192 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2193 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2197 ret = get_state_failrec(failure_tree, start, &failrec);
2199 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2203 failrec->start = start;
2204 failrec->len = end - start + 1;
2205 failrec->this_mirror = 0;
2206 failrec->bio_flags = 0;
2207 failrec->in_validation = 0;
2209 read_lock(&em_tree->lock);
2210 em = lookup_extent_mapping(em_tree, start, failrec->len);
2212 read_unlock(&em_tree->lock);
2217 if (em->start > start || em->start + em->len <= start) {
2218 free_extent_map(em);
2221 read_unlock(&em_tree->lock);
2227 logical = start - em->start;
2228 logical = em->block_start + logical;
2229 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2230 logical = em->block_start;
2231 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2232 extent_set_compress_type(&failrec->bio_flags,
2236 btrfs_debug(fs_info,
2237 "Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu",
2238 logical, start, failrec->len);
2240 failrec->logical = logical;
2241 free_extent_map(em);
2243 /* set the bits in the private failure tree */
2244 ret = set_extent_bits(failure_tree, start, end,
2245 EXTENT_LOCKED | EXTENT_DIRTY);
2247 ret = set_state_failrec(failure_tree, start, failrec);
2248 /* set the bits in the inode's tree */
2250 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2256 btrfs_debug(fs_info,
2257 "Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d",
2258 failrec->logical, failrec->start, failrec->len,
2259 failrec->in_validation);
2261 * when data can be on disk more than twice, add to failrec here
2262 * (e.g. with a list for failed_mirror) to make
2263 * clean_io_failure() clean all those errors at once.
2267 *failrec_ret = failrec;
2272 int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
2273 struct io_failure_record *failrec, int failed_mirror)
2275 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2278 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
2279 if (num_copies == 1) {
2281 * we only have a single copy of the data, so don't bother with
2282 * all the retry and error correction code that follows. no
2283 * matter what the error is, it is very likely to persist.
2285 btrfs_debug(fs_info,
2286 "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
2287 num_copies, failrec->this_mirror, failed_mirror);
2292 * there are two premises:
2293 * a) deliver good data to the caller
2294 * b) correct the bad sectors on disk
2296 if (failed_bio->bi_vcnt > 1) {
2298 * to fulfill b), we need to know the exact failing sectors, as
2299 * we don't want to rewrite any more than the failed ones. thus,
2300 * we need separate read requests for the failed bio
2302 * if the following BUG_ON triggers, our validation request got
2303 * merged. we need separate requests for our algorithm to work.
2305 BUG_ON(failrec->in_validation);
2306 failrec->in_validation = 1;
2307 failrec->this_mirror = failed_mirror;
2310 * we're ready to fulfill a) and b) alongside. get a good copy
2311 * of the failed sector and if we succeed, we have setup
2312 * everything for repair_io_failure to do the rest for us.
2314 if (failrec->in_validation) {
2315 BUG_ON(failrec->this_mirror != failed_mirror);
2316 failrec->in_validation = 0;
2317 failrec->this_mirror = 0;
2319 failrec->failed_mirror = failed_mirror;
2320 failrec->this_mirror++;
2321 if (failrec->this_mirror == failed_mirror)
2322 failrec->this_mirror++;
2325 if (failrec->this_mirror > num_copies) {
2326 btrfs_debug(fs_info,
2327 "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
2328 num_copies, failrec->this_mirror, failed_mirror);
2336 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
2337 struct io_failure_record *failrec,
2338 struct page *page, int pg_offset, int icsum,
2339 bio_end_io_t *endio_func, void *data)
2341 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2343 struct btrfs_io_bio *btrfs_failed_bio;
2344 struct btrfs_io_bio *btrfs_bio;
2346 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2350 bio->bi_end_io = endio_func;
2351 bio->bi_iter.bi_sector = failrec->logical >> 9;
2352 bio->bi_bdev = fs_info->fs_devices->latest_bdev;
2353 bio->bi_iter.bi_size = 0;
2354 bio->bi_private = data;
2356 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2357 if (btrfs_failed_bio->csum) {
2358 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2360 btrfs_bio = btrfs_io_bio(bio);
2361 btrfs_bio->csum = btrfs_bio->csum_inline;
2363 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
2367 bio_add_page(bio, page, failrec->len, pg_offset);
2373 * this is a generic handler for readpage errors (default
2374 * readpage_io_failed_hook). if other copies exist, read those and write back
2375 * good data to the failed position. does not investigate in remapping the
2376 * failed extent elsewhere, hoping the device will be smart enough to do this as
2380 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2381 struct page *page, u64 start, u64 end,
2384 struct io_failure_record *failrec;
2385 struct inode *inode = page->mapping->host;
2386 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2391 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2393 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2397 ret = btrfs_check_repairable(inode, failed_bio, failrec, failed_mirror);
2399 free_io_failure(BTRFS_I(inode), failrec);
2403 if (failed_bio->bi_vcnt > 1)
2404 read_mode |= REQ_FAILFAST_DEV;
2406 phy_offset >>= inode->i_sb->s_blocksize_bits;
2407 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
2408 start - page_offset(page),
2409 (int)phy_offset, failed_bio->bi_end_io,
2412 free_io_failure(BTRFS_I(inode), failrec);
2415 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
2417 btrfs_debug(btrfs_sb(inode->i_sb),
2418 "Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d",
2419 read_mode, failrec->this_mirror, failrec->in_validation);
2421 ret = tree->ops->submit_bio_hook(inode, bio, failrec->this_mirror,
2422 failrec->bio_flags, 0);
2424 free_io_failure(BTRFS_I(inode), failrec);
2431 /* lots and lots of room for performance fixes in the end_bio funcs */
2433 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2435 int uptodate = (err == 0);
2436 struct extent_io_tree *tree;
2439 tree = &BTRFS_I(page->mapping->host)->io_tree;
2441 if (tree->ops && tree->ops->writepage_end_io_hook)
2442 tree->ops->writepage_end_io_hook(page, start, end, NULL,
2446 ClearPageUptodate(page);
2448 ret = ret < 0 ? ret : -EIO;
2449 mapping_set_error(page->mapping, ret);
2454 * after a writepage IO is done, we need to:
2455 * clear the uptodate bits on error
2456 * clear the writeback bits in the extent tree for this IO
2457 * end_page_writeback if the page has no more pending IO
2459 * Scheduling is not allowed, so the extent state tree is expected
2460 * to have one and only one object corresponding to this IO.
2462 static void end_bio_extent_writepage(struct bio *bio)
2464 struct bio_vec *bvec;
2469 bio_for_each_segment_all(bvec, bio, i) {
2470 struct page *page = bvec->bv_page;
2471 struct inode *inode = page->mapping->host;
2472 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2474 /* We always issue full-page reads, but if some block
2475 * in a page fails to read, blk_update_request() will
2476 * advance bv_offset and adjust bv_len to compensate.
2477 * Print a warning for nonzero offsets, and an error
2478 * if they don't add up to a full page. */
2479 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2480 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2482 "partial page write in btrfs with offset %u and length %u",
2483 bvec->bv_offset, bvec->bv_len);
2486 "incomplete page write in btrfs with offset %u and length %u",
2487 bvec->bv_offset, bvec->bv_len);
2490 start = page_offset(page);
2491 end = start + bvec->bv_offset + bvec->bv_len - 1;
2493 end_extent_writepage(page, bio->bi_error, start, end);
2494 end_page_writeback(page);
2501 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2504 struct extent_state *cached = NULL;
2505 u64 end = start + len - 1;
2507 if (uptodate && tree->track_uptodate)
2508 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2509 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2513 * after a readpage IO is done, we need to:
2514 * clear the uptodate bits on error
2515 * set the uptodate bits if things worked
2516 * set the page up to date if all extents in the tree are uptodate
2517 * clear the lock bit in the extent tree
2518 * unlock the page if there are no other extents locked for it
2520 * Scheduling is not allowed, so the extent state tree is expected
2521 * to have one and only one object corresponding to this IO.
2523 static void end_bio_extent_readpage(struct bio *bio)
2525 struct bio_vec *bvec;
2526 int uptodate = !bio->bi_error;
2527 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2528 struct extent_io_tree *tree;
2533 u64 extent_start = 0;
2539 bio_for_each_segment_all(bvec, bio, i) {
2540 struct page *page = bvec->bv_page;
2541 struct inode *inode = page->mapping->host;
2542 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2544 btrfs_debug(fs_info,
2545 "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
2546 (u64)bio->bi_iter.bi_sector, bio->bi_error,
2547 io_bio->mirror_num);
2548 tree = &BTRFS_I(inode)->io_tree;
2550 /* We always issue full-page reads, but if some block
2551 * in a page fails to read, blk_update_request() will
2552 * advance bv_offset and adjust bv_len to compensate.
2553 * Print a warning for nonzero offsets, and an error
2554 * if they don't add up to a full page. */
2555 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2556 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2558 "partial page read in btrfs with offset %u and length %u",
2559 bvec->bv_offset, bvec->bv_len);
2562 "incomplete page read in btrfs with offset %u and length %u",
2563 bvec->bv_offset, bvec->bv_len);
2566 start = page_offset(page);
2567 end = start + bvec->bv_offset + bvec->bv_len - 1;
2570 mirror = io_bio->mirror_num;
2571 if (likely(uptodate && tree->ops)) {
2572 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2578 clean_io_failure(BTRFS_I(inode), start,
2582 if (likely(uptodate))
2586 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2587 if (ret == -EAGAIN) {
2589 * Data inode's readpage_io_failed_hook() always
2592 * The generic bio_readpage_error handles errors
2593 * the following way: If possible, new read
2594 * requests are created and submitted and will
2595 * end up in end_bio_extent_readpage as well (if
2596 * we're lucky, not in the !uptodate case). In
2597 * that case it returns 0 and we just go on with
2598 * the next page in our bio. If it can't handle
2599 * the error it will return -EIO and we remain
2600 * responsible for that page.
2602 ret = bio_readpage_error(bio, offset, page,
2603 start, end, mirror);
2605 uptodate = !bio->bi_error;
2612 * metadata's readpage_io_failed_hook() always returns
2613 * -EIO and fixes nothing. -EIO is also returned if
2614 * data inode error could not be fixed.
2616 ASSERT(ret == -EIO);
2619 if (likely(uptodate)) {
2620 loff_t i_size = i_size_read(inode);
2621 pgoff_t end_index = i_size >> PAGE_SHIFT;
2624 /* Zero out the end if this page straddles i_size */
2625 off = i_size & (PAGE_SIZE-1);
2626 if (page->index == end_index && off)
2627 zero_user_segment(page, off, PAGE_SIZE);
2628 SetPageUptodate(page);
2630 ClearPageUptodate(page);
2636 if (unlikely(!uptodate)) {
2638 endio_readpage_release_extent(tree,
2644 endio_readpage_release_extent(tree, start,
2645 end - start + 1, 0);
2646 } else if (!extent_len) {
2647 extent_start = start;
2648 extent_len = end + 1 - start;
2649 } else if (extent_start + extent_len == start) {
2650 extent_len += end + 1 - start;
2652 endio_readpage_release_extent(tree, extent_start,
2653 extent_len, uptodate);
2654 extent_start = start;
2655 extent_len = end + 1 - start;
2660 endio_readpage_release_extent(tree, extent_start, extent_len,
2663 io_bio->end_io(io_bio, bio->bi_error);
2668 * this allocates from the btrfs_bioset. We're returning a bio right now
2669 * but you can call btrfs_io_bio for the appropriate container_of magic
2672 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2675 struct btrfs_io_bio *btrfs_bio;
2678 bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset);
2680 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2681 while (!bio && (nr_vecs /= 2)) {
2682 bio = bio_alloc_bioset(gfp_flags,
2683 nr_vecs, btrfs_bioset);
2688 bio->bi_bdev = bdev;
2689 bio->bi_iter.bi_sector = first_sector;
2690 btrfs_bio = btrfs_io_bio(bio);
2691 btrfs_bio->csum = NULL;
2692 btrfs_bio->csum_allocated = NULL;
2693 btrfs_bio->end_io = NULL;
2698 struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
2700 struct btrfs_io_bio *btrfs_bio;
2703 new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset);
2705 btrfs_bio = btrfs_io_bio(new);
2706 btrfs_bio->csum = NULL;
2707 btrfs_bio->csum_allocated = NULL;
2708 btrfs_bio->end_io = NULL;
2713 /* this also allocates from the btrfs_bioset */
2714 struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
2716 struct btrfs_io_bio *btrfs_bio;
2719 bio = bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
2721 btrfs_bio = btrfs_io_bio(bio);
2722 btrfs_bio->csum = NULL;
2723 btrfs_bio->csum_allocated = NULL;
2724 btrfs_bio->end_io = NULL;
2730 static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
2731 unsigned long bio_flags)
2734 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2735 struct page *page = bvec->bv_page;
2736 struct extent_io_tree *tree = bio->bi_private;
2739 start = page_offset(page) + bvec->bv_offset;
2741 bio->bi_private = NULL;
2745 ret = tree->ops->submit_bio_hook(page->mapping->host, bio,
2746 mirror_num, bio_flags, start);
2748 btrfsic_submit_bio(bio);
2754 static int merge_bio(struct extent_io_tree *tree, struct page *page,
2755 unsigned long offset, size_t size, struct bio *bio,
2756 unsigned long bio_flags)
2760 ret = tree->ops->merge_bio_hook(page, offset, size, bio,
2766 static int submit_extent_page(int op, int op_flags, struct extent_io_tree *tree,
2767 struct writeback_control *wbc,
2768 struct page *page, sector_t sector,
2769 size_t size, unsigned long offset,
2770 struct block_device *bdev,
2771 struct bio **bio_ret,
2772 bio_end_io_t end_io_func,
2774 unsigned long prev_bio_flags,
2775 unsigned long bio_flags,
2776 bool force_bio_submit)
2781 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2782 size_t page_size = min_t(size_t, size, PAGE_SIZE);
2784 if (bio_ret && *bio_ret) {
2787 contig = bio->bi_iter.bi_sector == sector;
2789 contig = bio_end_sector(bio) == sector;
2791 if (prev_bio_flags != bio_flags || !contig ||
2793 merge_bio(tree, page, offset, page_size, bio, bio_flags) ||
2794 bio_add_page(bio, page, page_size, offset) < page_size) {
2795 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
2803 wbc_account_io(wbc, page, page_size);
2808 bio = btrfs_bio_alloc(bdev, sector, BIO_MAX_PAGES,
2809 GFP_NOFS | __GFP_HIGH);
2813 bio_add_page(bio, page, page_size, offset);
2814 bio->bi_end_io = end_io_func;
2815 bio->bi_private = tree;
2816 bio_set_op_attrs(bio, op, op_flags);
2818 wbc_init_bio(wbc, bio);
2819 wbc_account_io(wbc, page, page_size);
2825 ret = submit_one_bio(bio, mirror_num, bio_flags);
2830 static void attach_extent_buffer_page(struct extent_buffer *eb,
2833 if (!PagePrivate(page)) {
2834 SetPagePrivate(page);
2836 set_page_private(page, (unsigned long)eb);
2838 WARN_ON(page->private != (unsigned long)eb);
2842 void set_page_extent_mapped(struct page *page)
2844 if (!PagePrivate(page)) {
2845 SetPagePrivate(page);
2847 set_page_private(page, EXTENT_PAGE_PRIVATE);
2851 static struct extent_map *
2852 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
2853 u64 start, u64 len, get_extent_t *get_extent,
2854 struct extent_map **em_cached)
2856 struct extent_map *em;
2858 if (em_cached && *em_cached) {
2860 if (extent_map_in_tree(em) && start >= em->start &&
2861 start < extent_map_end(em)) {
2862 atomic_inc(&em->refs);
2866 free_extent_map(em);
2870 em = get_extent(BTRFS_I(inode), page, pg_offset, start, len, 0);
2871 if (em_cached && !IS_ERR_OR_NULL(em)) {
2873 atomic_inc(&em->refs);
2879 * basic readpage implementation. Locked extent state structs are inserted
2880 * into the tree that are removed when the IO is done (by the end_io
2882 * XXX JDM: This needs looking at to ensure proper page locking
2883 * return 0 on success, otherwise return error
2885 static int __do_readpage(struct extent_io_tree *tree,
2887 get_extent_t *get_extent,
2888 struct extent_map **em_cached,
2889 struct bio **bio, int mirror_num,
2890 unsigned long *bio_flags, int read_flags,
2893 struct inode *inode = page->mapping->host;
2894 u64 start = page_offset(page);
2895 u64 page_end = start + PAGE_SIZE - 1;
2899 u64 last_byte = i_size_read(inode);
2903 struct extent_map *em;
2904 struct block_device *bdev;
2907 size_t pg_offset = 0;
2909 size_t disk_io_size;
2910 size_t blocksize = inode->i_sb->s_blocksize;
2911 unsigned long this_bio_flag = 0;
2913 set_page_extent_mapped(page);
2916 if (!PageUptodate(page)) {
2917 if (cleancache_get_page(page) == 0) {
2918 BUG_ON(blocksize != PAGE_SIZE);
2919 unlock_extent(tree, start, end);
2924 if (page->index == last_byte >> PAGE_SHIFT) {
2926 size_t zero_offset = last_byte & (PAGE_SIZE - 1);
2929 iosize = PAGE_SIZE - zero_offset;
2930 userpage = kmap_atomic(page);
2931 memset(userpage + zero_offset, 0, iosize);
2932 flush_dcache_page(page);
2933 kunmap_atomic(userpage);
2936 while (cur <= end) {
2937 bool force_bio_submit = false;
2939 if (cur >= last_byte) {
2941 struct extent_state *cached = NULL;
2943 iosize = PAGE_SIZE - pg_offset;
2944 userpage = kmap_atomic(page);
2945 memset(userpage + pg_offset, 0, iosize);
2946 flush_dcache_page(page);
2947 kunmap_atomic(userpage);
2948 set_extent_uptodate(tree, cur, cur + iosize - 1,
2950 unlock_extent_cached(tree, cur,
2955 em = __get_extent_map(inode, page, pg_offset, cur,
2956 end - cur + 1, get_extent, em_cached);
2957 if (IS_ERR_OR_NULL(em)) {
2959 unlock_extent(tree, cur, end);
2962 extent_offset = cur - em->start;
2963 BUG_ON(extent_map_end(em) <= cur);
2966 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2967 this_bio_flag |= EXTENT_BIO_COMPRESSED;
2968 extent_set_compress_type(&this_bio_flag,
2972 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2973 cur_end = min(extent_map_end(em) - 1, end);
2974 iosize = ALIGN(iosize, blocksize);
2975 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2976 disk_io_size = em->block_len;
2977 sector = em->block_start >> 9;
2979 sector = (em->block_start + extent_offset) >> 9;
2980 disk_io_size = iosize;
2983 block_start = em->block_start;
2984 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2985 block_start = EXTENT_MAP_HOLE;
2988 * If we have a file range that points to a compressed extent
2989 * and it's followed by a consecutive file range that points to
2990 * to the same compressed extent (possibly with a different
2991 * offset and/or length, so it either points to the whole extent
2992 * or only part of it), we must make sure we do not submit a
2993 * single bio to populate the pages for the 2 ranges because
2994 * this makes the compressed extent read zero out the pages
2995 * belonging to the 2nd range. Imagine the following scenario:
2998 * [0 - 8K] [8K - 24K]
3001 * points to extent X, points to extent X,
3002 * offset 4K, length of 8K offset 0, length 16K
3004 * [extent X, compressed length = 4K uncompressed length = 16K]
3006 * If the bio to read the compressed extent covers both ranges,
3007 * it will decompress extent X into the pages belonging to the
3008 * first range and then it will stop, zeroing out the remaining
3009 * pages that belong to the other range that points to extent X.
3010 * So here we make sure we submit 2 bios, one for the first
3011 * range and another one for the third range. Both will target
3012 * the same physical extent from disk, but we can't currently
3013 * make the compressed bio endio callback populate the pages
3014 * for both ranges because each compressed bio is tightly
3015 * coupled with a single extent map, and each range can have
3016 * an extent map with a different offset value relative to the
3017 * uncompressed data of our extent and different lengths. This
3018 * is a corner case so we prioritize correctness over
3019 * non-optimal behavior (submitting 2 bios for the same extent).
3021 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3022 prev_em_start && *prev_em_start != (u64)-1 &&
3023 *prev_em_start != em->orig_start)
3024 force_bio_submit = true;
3027 *prev_em_start = em->orig_start;
3029 free_extent_map(em);
3032 /* we've found a hole, just zero and go on */
3033 if (block_start == EXTENT_MAP_HOLE) {
3035 struct extent_state *cached = NULL;
3037 userpage = kmap_atomic(page);
3038 memset(userpage + pg_offset, 0, iosize);
3039 flush_dcache_page(page);
3040 kunmap_atomic(userpage);
3042 set_extent_uptodate(tree, cur, cur + iosize - 1,
3044 unlock_extent_cached(tree, cur,
3048 pg_offset += iosize;
3051 /* the get_extent function already copied into the page */
3052 if (test_range_bit(tree, cur, cur_end,
3053 EXTENT_UPTODATE, 1, NULL)) {
3054 check_page_uptodate(tree, page);
3055 unlock_extent(tree, cur, cur + iosize - 1);
3057 pg_offset += iosize;
3060 /* we have an inline extent but it didn't get marked up
3061 * to date. Error out
3063 if (block_start == EXTENT_MAP_INLINE) {
3065 unlock_extent(tree, cur, cur + iosize - 1);
3067 pg_offset += iosize;
3071 ret = submit_extent_page(REQ_OP_READ, read_flags, tree, NULL,
3072 page, sector, disk_io_size, pg_offset,
3074 end_bio_extent_readpage, mirror_num,
3080 *bio_flags = this_bio_flag;
3083 unlock_extent(tree, cur, cur + iosize - 1);
3087 pg_offset += iosize;
3091 if (!PageError(page))
3092 SetPageUptodate(page);
3098 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
3099 struct page *pages[], int nr_pages,
3101 get_extent_t *get_extent,
3102 struct extent_map **em_cached,
3103 struct bio **bio, int mirror_num,
3104 unsigned long *bio_flags,
3107 struct inode *inode;
3108 struct btrfs_ordered_extent *ordered;
3111 inode = pages[0]->mapping->host;
3113 lock_extent(tree, start, end);
3114 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
3118 unlock_extent(tree, start, end);
3119 btrfs_start_ordered_extent(inode, ordered, 1);
3120 btrfs_put_ordered_extent(ordered);
3123 for (index = 0; index < nr_pages; index++) {
3124 __do_readpage(tree, pages[index], get_extent, em_cached, bio,
3125 mirror_num, bio_flags, 0, prev_em_start);
3126 put_page(pages[index]);
3130 static void __extent_readpages(struct extent_io_tree *tree,
3131 struct page *pages[],
3132 int nr_pages, get_extent_t *get_extent,
3133 struct extent_map **em_cached,
3134 struct bio **bio, int mirror_num,
3135 unsigned long *bio_flags,
3142 int first_index = 0;
3144 for (index = 0; index < nr_pages; index++) {
3145 page_start = page_offset(pages[index]);
3148 end = start + PAGE_SIZE - 1;
3149 first_index = index;
3150 } else if (end + 1 == page_start) {
3153 __do_contiguous_readpages(tree, &pages[first_index],
3154 index - first_index, start,
3155 end, get_extent, em_cached,
3156 bio, mirror_num, bio_flags,
3159 end = start + PAGE_SIZE - 1;
3160 first_index = index;
3165 __do_contiguous_readpages(tree, &pages[first_index],
3166 index - first_index, start,
3167 end, get_extent, em_cached, bio,
3168 mirror_num, bio_flags,
3172 static int __extent_read_full_page(struct extent_io_tree *tree,
3174 get_extent_t *get_extent,
3175 struct bio **bio, int mirror_num,
3176 unsigned long *bio_flags, int read_flags)
3178 struct inode *inode = page->mapping->host;
3179 struct btrfs_ordered_extent *ordered;
3180 u64 start = page_offset(page);
3181 u64 end = start + PAGE_SIZE - 1;
3185 lock_extent(tree, start, end);
3186 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
3190 unlock_extent(tree, start, end);
3191 btrfs_start_ordered_extent(inode, ordered, 1);
3192 btrfs_put_ordered_extent(ordered);
3195 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3196 bio_flags, read_flags, NULL);
3200 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3201 get_extent_t *get_extent, int mirror_num)
3203 struct bio *bio = NULL;
3204 unsigned long bio_flags = 0;
3207 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3210 ret = submit_one_bio(bio, mirror_num, bio_flags);
3214 static void update_nr_written(struct writeback_control *wbc,
3215 unsigned long nr_written)
3217 wbc->nr_to_write -= nr_written;
3221 * helper for __extent_writepage, doing all of the delayed allocation setup.
3223 * This returns 1 if our fill_delalloc function did all the work required
3224 * to write the page (copy into inline extent). In this case the IO has
3225 * been started and the page is already unlocked.
3227 * This returns 0 if all went well (page still locked)
3228 * This returns < 0 if there were errors (page still locked)
3230 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3231 struct page *page, struct writeback_control *wbc,
3232 struct extent_page_data *epd,
3234 unsigned long *nr_written)
3236 struct extent_io_tree *tree = epd->tree;
3237 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3239 u64 delalloc_to_write = 0;
3240 u64 delalloc_end = 0;
3242 int page_started = 0;
3244 if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
3247 while (delalloc_end < page_end) {
3248 nr_delalloc = find_lock_delalloc_range(inode, tree,
3252 BTRFS_MAX_EXTENT_SIZE);
3253 if (nr_delalloc == 0) {
3254 delalloc_start = delalloc_end + 1;
3257 ret = tree->ops->fill_delalloc(inode, page,
3262 /* File system has been set read-only */
3265 /* fill_delalloc should be return < 0 for error
3266 * but just in case, we use > 0 here meaning the
3267 * IO is started, so we don't want to return > 0
3268 * unless things are going well.
3270 ret = ret < 0 ? ret : -EIO;
3274 * delalloc_end is already one less than the total length, so
3275 * we don't subtract one from PAGE_SIZE
3277 delalloc_to_write += (delalloc_end - delalloc_start +
3278 PAGE_SIZE) >> PAGE_SHIFT;
3279 delalloc_start = delalloc_end + 1;
3281 if (wbc->nr_to_write < delalloc_to_write) {
3284 if (delalloc_to_write < thresh * 2)
3285 thresh = delalloc_to_write;
3286 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3290 /* did the fill delalloc function already unlock and start
3295 * we've unlocked the page, so we can't update
3296 * the mapping's writeback index, just update
3299 wbc->nr_to_write -= *nr_written;
3310 * helper for __extent_writepage. This calls the writepage start hooks,
3311 * and does the loop to map the page into extents and bios.
3313 * We return 1 if the IO is started and the page is unlocked,
3314 * 0 if all went well (page still locked)
3315 * < 0 if there were errors (page still locked)
3317 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3319 struct writeback_control *wbc,
3320 struct extent_page_data *epd,
3322 unsigned long nr_written,
3323 int write_flags, int *nr_ret)
3325 struct extent_io_tree *tree = epd->tree;
3326 u64 start = page_offset(page);
3327 u64 page_end = start + PAGE_SIZE - 1;
3334 struct extent_map *em;
3335 struct block_device *bdev;
3336 size_t pg_offset = 0;
3342 if (tree->ops && tree->ops->writepage_start_hook) {
3343 ret = tree->ops->writepage_start_hook(page, start,
3346 /* Fixup worker will requeue */
3348 wbc->pages_skipped++;
3350 redirty_page_for_writepage(wbc, page);
3352 update_nr_written(wbc, nr_written);
3359 * we don't want to touch the inode after unlocking the page,
3360 * so we update the mapping writeback index now
3362 update_nr_written(wbc, nr_written + 1);
3365 if (i_size <= start) {
3366 if (tree->ops && tree->ops->writepage_end_io_hook)
3367 tree->ops->writepage_end_io_hook(page, start,
3372 blocksize = inode->i_sb->s_blocksize;
3374 while (cur <= end) {
3377 if (cur >= i_size) {
3378 if (tree->ops && tree->ops->writepage_end_io_hook)
3379 tree->ops->writepage_end_io_hook(page, cur,
3383 em = epd->get_extent(BTRFS_I(inode), page, pg_offset, cur,
3385 if (IS_ERR_OR_NULL(em)) {
3387 ret = PTR_ERR_OR_ZERO(em);
3391 extent_offset = cur - em->start;
3392 em_end = extent_map_end(em);
3393 BUG_ON(em_end <= cur);
3395 iosize = min(em_end - cur, end - cur + 1);
3396 iosize = ALIGN(iosize, blocksize);
3397 sector = (em->block_start + extent_offset) >> 9;
3399 block_start = em->block_start;
3400 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3401 free_extent_map(em);
3405 * compressed and inline extents are written through other
3408 if (compressed || block_start == EXTENT_MAP_HOLE ||
3409 block_start == EXTENT_MAP_INLINE) {
3411 * end_io notification does not happen here for
3412 * compressed extents
3414 if (!compressed && tree->ops &&
3415 tree->ops->writepage_end_io_hook)
3416 tree->ops->writepage_end_io_hook(page, cur,
3419 else if (compressed) {
3420 /* we don't want to end_page_writeback on
3421 * a compressed extent. this happens
3428 pg_offset += iosize;
3432 set_range_writeback(tree, cur, cur + iosize - 1);
3433 if (!PageWriteback(page)) {
3434 btrfs_err(BTRFS_I(inode)->root->fs_info,
3435 "page %lu not writeback, cur %llu end %llu",
3436 page->index, cur, end);
3439 ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
3440 page, sector, iosize, pg_offset,
3442 end_bio_extent_writepage,
3446 if (PageWriteback(page))
3447 end_page_writeback(page);
3451 pg_offset += iosize;
3460 * the writepage semantics are similar to regular writepage. extent
3461 * records are inserted to lock ranges in the tree, and as dirty areas
3462 * are found, they are marked writeback. Then the lock bits are removed
3463 * and the end_io handler clears the writeback ranges
3465 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3468 struct inode *inode = page->mapping->host;
3469 struct extent_page_data *epd = data;
3470 u64 start = page_offset(page);
3471 u64 page_end = start + PAGE_SIZE - 1;
3474 size_t pg_offset = 0;
3475 loff_t i_size = i_size_read(inode);
3476 unsigned long end_index = i_size >> PAGE_SHIFT;
3477 int write_flags = 0;
3478 unsigned long nr_written = 0;
3480 if (wbc->sync_mode == WB_SYNC_ALL)
3481 write_flags = REQ_SYNC;
3483 trace___extent_writepage(page, inode, wbc);
3485 WARN_ON(!PageLocked(page));
3487 ClearPageError(page);
3489 pg_offset = i_size & (PAGE_SIZE - 1);
3490 if (page->index > end_index ||
3491 (page->index == end_index && !pg_offset)) {
3492 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3497 if (page->index == end_index) {
3500 userpage = kmap_atomic(page);
3501 memset(userpage + pg_offset, 0,
3502 PAGE_SIZE - pg_offset);
3503 kunmap_atomic(userpage);
3504 flush_dcache_page(page);
3509 set_page_extent_mapped(page);
3511 ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
3517 ret = __extent_writepage_io(inode, page, wbc, epd,
3518 i_size, nr_written, write_flags, &nr);
3524 /* make sure the mapping tag for page dirty gets cleared */
3525 set_page_writeback(page);
3526 end_page_writeback(page);
3528 if (PageError(page)) {
3529 ret = ret < 0 ? ret : -EIO;
3530 end_extent_writepage(page, ret, start, page_end);
3539 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3541 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3542 TASK_UNINTERRUPTIBLE);
3545 static noinline_for_stack int
3546 lock_extent_buffer_for_io(struct extent_buffer *eb,
3547 struct btrfs_fs_info *fs_info,
3548 struct extent_page_data *epd)
3550 unsigned long i, num_pages;
3554 if (!btrfs_try_tree_write_lock(eb)) {
3556 flush_write_bio(epd);
3557 btrfs_tree_lock(eb);
3560 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3561 btrfs_tree_unlock(eb);
3565 flush_write_bio(epd);
3569 wait_on_extent_buffer_writeback(eb);
3570 btrfs_tree_lock(eb);
3571 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3573 btrfs_tree_unlock(eb);
3578 * We need to do this to prevent races in people who check if the eb is
3579 * under IO since we can end up having no IO bits set for a short period
3582 spin_lock(&eb->refs_lock);
3583 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3584 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3585 spin_unlock(&eb->refs_lock);
3586 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3587 __percpu_counter_add(&fs_info->dirty_metadata_bytes,
3589 fs_info->dirty_metadata_batch);
3592 spin_unlock(&eb->refs_lock);
3595 btrfs_tree_unlock(eb);
3600 num_pages = num_extent_pages(eb->start, eb->len);
3601 for (i = 0; i < num_pages; i++) {
3602 struct page *p = eb->pages[i];
3604 if (!trylock_page(p)) {
3606 flush_write_bio(epd);
3616 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3618 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3619 smp_mb__after_atomic();
3620 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3623 static void set_btree_ioerr(struct page *page)
3625 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3628 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3632 * If writeback for a btree extent that doesn't belong to a log tree
3633 * failed, increment the counter transaction->eb_write_errors.
3634 * We do this because while the transaction is running and before it's
3635 * committing (when we call filemap_fdata[write|wait]_range against
3636 * the btree inode), we might have
3637 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3638 * returns an error or an error happens during writeback, when we're
3639 * committing the transaction we wouldn't know about it, since the pages
3640 * can be no longer dirty nor marked anymore for writeback (if a
3641 * subsequent modification to the extent buffer didn't happen before the
3642 * transaction commit), which makes filemap_fdata[write|wait]_range not
3643 * able to find the pages tagged with SetPageError at transaction
3644 * commit time. So if this happens we must abort the transaction,
3645 * otherwise we commit a super block with btree roots that point to
3646 * btree nodes/leafs whose content on disk is invalid - either garbage
3647 * or the content of some node/leaf from a past generation that got
3648 * cowed or deleted and is no longer valid.
3650 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3651 * not be enough - we need to distinguish between log tree extents vs
3652 * non-log tree extents, and the next filemap_fdatawait_range() call
3653 * will catch and clear such errors in the mapping - and that call might
3654 * be from a log sync and not from a transaction commit. Also, checking
3655 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3656 * not done and would not be reliable - the eb might have been released
3657 * from memory and reading it back again means that flag would not be
3658 * set (since it's a runtime flag, not persisted on disk).
3660 * Using the flags below in the btree inode also makes us achieve the
3661 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3662 * writeback for all dirty pages and before filemap_fdatawait_range()
3663 * is called, the writeback for all dirty pages had already finished
3664 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3665 * filemap_fdatawait_range() would return success, as it could not know
3666 * that writeback errors happened (the pages were no longer tagged for
3669 switch (eb->log_index) {
3671 set_bit(BTRFS_FS_BTREE_ERR, &eb->fs_info->flags);
3674 set_bit(BTRFS_FS_LOG1_ERR, &eb->fs_info->flags);
3677 set_bit(BTRFS_FS_LOG2_ERR, &eb->fs_info->flags);
3680 BUG(); /* unexpected, logic error */
3684 static void end_bio_extent_buffer_writepage(struct bio *bio)
3686 struct bio_vec *bvec;
3687 struct extent_buffer *eb;
3690 bio_for_each_segment_all(bvec, bio, i) {
3691 struct page *page = bvec->bv_page;
3693 eb = (struct extent_buffer *)page->private;
3695 done = atomic_dec_and_test(&eb->io_pages);
3697 if (bio->bi_error ||
3698 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3699 ClearPageUptodate(page);
3700 set_btree_ioerr(page);
3703 end_page_writeback(page);
3708 end_extent_buffer_writeback(eb);
3714 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3715 struct btrfs_fs_info *fs_info,
3716 struct writeback_control *wbc,
3717 struct extent_page_data *epd)
3719 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3720 struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
3721 u64 offset = eb->start;
3723 unsigned long i, num_pages;
3724 unsigned long bio_flags = 0;
3725 unsigned long start, end;
3726 int write_flags = (epd->sync_io ? REQ_SYNC : 0) | REQ_META;
3729 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3730 num_pages = num_extent_pages(eb->start, eb->len);
3731 atomic_set(&eb->io_pages, num_pages);
3732 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3733 bio_flags = EXTENT_BIO_TREE_LOG;
3735 /* set btree blocks beyond nritems with 0 to avoid stale content. */
3736 nritems = btrfs_header_nritems(eb);
3737 if (btrfs_header_level(eb) > 0) {
3738 end = btrfs_node_key_ptr_offset(nritems);
3740 memzero_extent_buffer(eb, end, eb->len - end);
3744 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
3746 start = btrfs_item_nr_offset(nritems);
3747 end = btrfs_leaf_data(eb) + leaf_data_end(fs_info, eb);
3748 memzero_extent_buffer(eb, start, end - start);
3751 for (i = 0; i < num_pages; i++) {
3752 struct page *p = eb->pages[i];
3754 clear_page_dirty_for_io(p);
3755 set_page_writeback(p);
3756 ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
3757 p, offset >> 9, PAGE_SIZE, 0, bdev,
3759 end_bio_extent_buffer_writepage,
3760 0, epd->bio_flags, bio_flags, false);
3761 epd->bio_flags = bio_flags;
3764 if (PageWriteback(p))
3765 end_page_writeback(p);
3766 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3767 end_extent_buffer_writeback(eb);
3771 offset += PAGE_SIZE;
3772 update_nr_written(wbc, 1);
3776 if (unlikely(ret)) {
3777 for (; i < num_pages; i++) {
3778 struct page *p = eb->pages[i];
3779 clear_page_dirty_for_io(p);
3787 int btree_write_cache_pages(struct address_space *mapping,
3788 struct writeback_control *wbc)
3790 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3791 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3792 struct extent_buffer *eb, *prev_eb = NULL;
3793 struct extent_page_data epd = {
3797 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3802 int nr_to_write_done = 0;
3803 struct pagevec pvec;
3806 pgoff_t end; /* Inclusive */
3810 pagevec_init(&pvec, 0);
3811 if (wbc->range_cyclic) {
3812 index = mapping->writeback_index; /* Start from prev offset */
3815 index = wbc->range_start >> PAGE_SHIFT;
3816 end = wbc->range_end >> PAGE_SHIFT;
3819 if (wbc->sync_mode == WB_SYNC_ALL)
3820 tag = PAGECACHE_TAG_TOWRITE;
3822 tag = PAGECACHE_TAG_DIRTY;
3824 if (wbc->sync_mode == WB_SYNC_ALL)
3825 tag_pages_for_writeback(mapping, index, end);
3826 while (!done && !nr_to_write_done && (index <= end) &&
3827 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3828 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3832 for (i = 0; i < nr_pages; i++) {
3833 struct page *page = pvec.pages[i];
3835 if (!PagePrivate(page))
3838 if (!wbc->range_cyclic && page->index > end) {
3843 spin_lock(&mapping->private_lock);
3844 if (!PagePrivate(page)) {
3845 spin_unlock(&mapping->private_lock);
3849 eb = (struct extent_buffer *)page->private;
3852 * Shouldn't happen and normally this would be a BUG_ON
3853 * but no sense in crashing the users box for something
3854 * we can survive anyway.
3857 spin_unlock(&mapping->private_lock);
3861 if (eb == prev_eb) {
3862 spin_unlock(&mapping->private_lock);
3866 ret = atomic_inc_not_zero(&eb->refs);
3867 spin_unlock(&mapping->private_lock);
3872 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3874 free_extent_buffer(eb);
3878 ret = write_one_eb(eb, fs_info, wbc, &epd);
3881 free_extent_buffer(eb);
3884 free_extent_buffer(eb);
3887 * the filesystem may choose to bump up nr_to_write.
3888 * We have to make sure to honor the new nr_to_write
3891 nr_to_write_done = wbc->nr_to_write <= 0;
3893 pagevec_release(&pvec);
3896 if (!scanned && !done) {
3898 * We hit the last page and there is more work to be done: wrap
3899 * back to the start of the file
3905 flush_write_bio(&epd);
3910 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3911 * @mapping: address space structure to write
3912 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3913 * @writepage: function called for each page
3914 * @data: data passed to writepage function
3916 * If a page is already under I/O, write_cache_pages() skips it, even
3917 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3918 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3919 * and msync() need to guarantee that all the data which was dirty at the time
3920 * the call was made get new I/O started against them. If wbc->sync_mode is
3921 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3922 * existing IO to complete.
3924 static int extent_write_cache_pages(struct address_space *mapping,
3925 struct writeback_control *wbc,
3926 writepage_t writepage, void *data,
3927 void (*flush_fn)(void *))
3929 struct inode *inode = mapping->host;
3932 int nr_to_write_done = 0;
3933 struct pagevec pvec;
3936 pgoff_t end; /* Inclusive */
3938 int range_whole = 0;
3943 * We have to hold onto the inode so that ordered extents can do their
3944 * work when the IO finishes. The alternative to this is failing to add
3945 * an ordered extent if the igrab() fails there and that is a huge pain
3946 * to deal with, so instead just hold onto the inode throughout the
3947 * writepages operation. If it fails here we are freeing up the inode
3948 * anyway and we'd rather not waste our time writing out stuff that is
3949 * going to be truncated anyway.
3954 pagevec_init(&pvec, 0);
3955 if (wbc->range_cyclic) {
3956 index = mapping->writeback_index; /* Start from prev offset */
3959 index = wbc->range_start >> PAGE_SHIFT;
3960 end = wbc->range_end >> PAGE_SHIFT;
3961 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
3965 if (wbc->sync_mode == WB_SYNC_ALL)
3966 tag = PAGECACHE_TAG_TOWRITE;
3968 tag = PAGECACHE_TAG_DIRTY;
3970 if (wbc->sync_mode == WB_SYNC_ALL)
3971 tag_pages_for_writeback(mapping, index, end);
3973 while (!done && !nr_to_write_done && (index <= end) &&
3974 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3975 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3979 for (i = 0; i < nr_pages; i++) {
3980 struct page *page = pvec.pages[i];
3982 done_index = page->index;
3984 * At this point we hold neither mapping->tree_lock nor
3985 * lock on the page itself: the page may be truncated or
3986 * invalidated (changing page->mapping to NULL), or even
3987 * swizzled back from swapper_space to tmpfs file
3990 if (!trylock_page(page)) {
3995 if (unlikely(page->mapping != mapping)) {
4000 if (!wbc->range_cyclic && page->index > end) {
4006 if (wbc->sync_mode != WB_SYNC_NONE) {
4007 if (PageWriteback(page))
4009 wait_on_page_writeback(page);
4012 if (PageWriteback(page) ||
4013 !clear_page_dirty_for_io(page)) {
4018 ret = (*writepage)(page, wbc, data);
4020 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
4026 * done_index is set past this page,
4027 * so media errors will not choke
4028 * background writeout for the entire
4029 * file. This has consequences for
4030 * range_cyclic semantics (ie. it may
4031 * not be suitable for data integrity
4034 done_index = page->index + 1;
4040 * the filesystem may choose to bump up nr_to_write.
4041 * We have to make sure to honor the new nr_to_write
4044 nr_to_write_done = wbc->nr_to_write <= 0;
4046 pagevec_release(&pvec);
4049 if (!scanned && !done) {
4051 * We hit the last page and there is more work to be done: wrap
4052 * back to the start of the file
4059 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4060 mapping->writeback_index = done_index;
4062 btrfs_add_delayed_iput(inode);
4066 static void flush_epd_write_bio(struct extent_page_data *epd)
4071 bio_set_op_attrs(epd->bio, REQ_OP_WRITE,
4072 epd->sync_io ? REQ_SYNC : 0);
4074 ret = submit_one_bio(epd->bio, 0, epd->bio_flags);
4075 BUG_ON(ret < 0); /* -ENOMEM */
4080 static noinline void flush_write_bio(void *data)
4082 struct extent_page_data *epd = data;
4083 flush_epd_write_bio(epd);
4086 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
4087 get_extent_t *get_extent,
4088 struct writeback_control *wbc)
4091 struct extent_page_data epd = {
4094 .get_extent = get_extent,
4096 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4100 ret = __extent_writepage(page, wbc, &epd);
4102 flush_epd_write_bio(&epd);
4106 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
4107 u64 start, u64 end, get_extent_t *get_extent,
4111 struct address_space *mapping = inode->i_mapping;
4113 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4116 struct extent_page_data epd = {
4119 .get_extent = get_extent,
4121 .sync_io = mode == WB_SYNC_ALL,
4124 struct writeback_control wbc_writepages = {
4126 .nr_to_write = nr_pages * 2,
4127 .range_start = start,
4128 .range_end = end + 1,
4131 while (start <= end) {
4132 page = find_get_page(mapping, start >> PAGE_SHIFT);
4133 if (clear_page_dirty_for_io(page))
4134 ret = __extent_writepage(page, &wbc_writepages, &epd);
4136 if (tree->ops && tree->ops->writepage_end_io_hook)
4137 tree->ops->writepage_end_io_hook(page, start,
4138 start + PAGE_SIZE - 1,
4146 flush_epd_write_bio(&epd);
4150 int extent_writepages(struct extent_io_tree *tree,
4151 struct address_space *mapping,
4152 get_extent_t *get_extent,
4153 struct writeback_control *wbc)
4156 struct extent_page_data epd = {
4159 .get_extent = get_extent,
4161 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4165 ret = extent_write_cache_pages(mapping, wbc, __extent_writepage, &epd,
4167 flush_epd_write_bio(&epd);
4171 int extent_readpages(struct extent_io_tree *tree,
4172 struct address_space *mapping,
4173 struct list_head *pages, unsigned nr_pages,
4174 get_extent_t get_extent)
4176 struct bio *bio = NULL;
4178 unsigned long bio_flags = 0;
4179 struct page *pagepool[16];
4181 struct extent_map *em_cached = NULL;
4183 u64 prev_em_start = (u64)-1;
4185 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
4186 page = list_entry(pages->prev, struct page, lru);
4188 prefetchw(&page->flags);
4189 list_del(&page->lru);
4190 if (add_to_page_cache_lru(page, mapping,
4192 readahead_gfp_mask(mapping))) {
4197 pagepool[nr++] = page;
4198 if (nr < ARRAY_SIZE(pagepool))
4200 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4201 &bio, 0, &bio_flags, &prev_em_start);
4205 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4206 &bio, 0, &bio_flags, &prev_em_start);
4209 free_extent_map(em_cached);
4211 BUG_ON(!list_empty(pages));
4213 return submit_one_bio(bio, 0, bio_flags);
4218 * basic invalidatepage code, this waits on any locked or writeback
4219 * ranges corresponding to the page, and then deletes any extent state
4220 * records from the tree
4222 int extent_invalidatepage(struct extent_io_tree *tree,
4223 struct page *page, unsigned long offset)
4225 struct extent_state *cached_state = NULL;
4226 u64 start = page_offset(page);
4227 u64 end = start + PAGE_SIZE - 1;
4228 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4230 start += ALIGN(offset, blocksize);
4234 lock_extent_bits(tree, start, end, &cached_state);
4235 wait_on_page_writeback(page);
4236 clear_extent_bit(tree, start, end,
4237 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
4238 EXTENT_DO_ACCOUNTING,
4239 1, 1, &cached_state, GFP_NOFS);
4244 * a helper for releasepage, this tests for areas of the page that
4245 * are locked or under IO and drops the related state bits if it is safe
4248 static int try_release_extent_state(struct extent_map_tree *map,
4249 struct extent_io_tree *tree,
4250 struct page *page, gfp_t mask)
4252 u64 start = page_offset(page);
4253 u64 end = start + PAGE_SIZE - 1;
4256 if (test_range_bit(tree, start, end,
4257 EXTENT_IOBITS, 0, NULL))
4261 * at this point we can safely clear everything except the
4262 * locked bit and the nodatasum bit
4264 ret = clear_extent_bit(tree, start, end,
4265 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4268 /* if clear_extent_bit failed for enomem reasons,
4269 * we can't allow the release to continue.
4280 * a helper for releasepage. As long as there are no locked extents
4281 * in the range corresponding to the page, both state records and extent
4282 * map records are removed
4284 int try_release_extent_mapping(struct extent_map_tree *map,
4285 struct extent_io_tree *tree, struct page *page,
4288 struct extent_map *em;
4289 u64 start = page_offset(page);
4290 u64 end = start + PAGE_SIZE - 1;
4292 if (gfpflags_allow_blocking(mask) &&
4293 page->mapping->host->i_size > SZ_16M) {
4295 while (start <= end) {
4296 len = end - start + 1;
4297 write_lock(&map->lock);
4298 em = lookup_extent_mapping(map, start, len);
4300 write_unlock(&map->lock);
4303 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4304 em->start != start) {
4305 write_unlock(&map->lock);
4306 free_extent_map(em);
4309 if (!test_range_bit(tree, em->start,
4310 extent_map_end(em) - 1,
4311 EXTENT_LOCKED | EXTENT_WRITEBACK,
4313 remove_extent_mapping(map, em);
4314 /* once for the rb tree */
4315 free_extent_map(em);
4317 start = extent_map_end(em);
4318 write_unlock(&map->lock);
4321 free_extent_map(em);
4324 return try_release_extent_state(map, tree, page, mask);
4328 * helper function for fiemap, which doesn't want to see any holes.
4329 * This maps until we find something past 'last'
4331 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4334 get_extent_t *get_extent)
4336 u64 sectorsize = btrfs_inode_sectorsize(inode);
4337 struct extent_map *em;
4344 len = last - offset;
4347 len = ALIGN(len, sectorsize);
4348 em = get_extent(BTRFS_I(inode), NULL, 0, offset, len, 0);
4349 if (IS_ERR_OR_NULL(em))
4352 /* if this isn't a hole return it */
4353 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
4354 em->block_start != EXTENT_MAP_HOLE) {
4358 /* this is a hole, advance to the next extent */
4359 offset = extent_map_end(em);
4360 free_extent_map(em);
4367 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4368 __u64 start, __u64 len, get_extent_t *get_extent)
4372 u64 max = start + len;
4376 u64 last_for_get_extent = 0;
4378 u64 isize = i_size_read(inode);
4379 struct btrfs_key found_key;
4380 struct extent_map *em = NULL;
4381 struct extent_state *cached_state = NULL;
4382 struct btrfs_path *path;
4383 struct btrfs_root *root = BTRFS_I(inode)->root;
4392 path = btrfs_alloc_path();
4395 path->leave_spinning = 1;
4397 start = round_down(start, btrfs_inode_sectorsize(inode));
4398 len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
4401 * lookup the last file extent. We're not using i_size here
4402 * because there might be preallocation past i_size
4404 ret = btrfs_lookup_file_extent(NULL, root, path,
4405 btrfs_ino(BTRFS_I(inode)), -1, 0);
4407 btrfs_free_path(path);
4416 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4417 found_type = found_key.type;
4419 /* No extents, but there might be delalloc bits */
4420 if (found_key.objectid != btrfs_ino(BTRFS_I(inode)) ||
4421 found_type != BTRFS_EXTENT_DATA_KEY) {
4422 /* have to trust i_size as the end */
4424 last_for_get_extent = isize;
4427 * remember the start of the last extent. There are a
4428 * bunch of different factors that go into the length of the
4429 * extent, so its much less complex to remember where it started
4431 last = found_key.offset;
4432 last_for_get_extent = last + 1;
4434 btrfs_release_path(path);
4437 * we might have some extents allocated but more delalloc past those
4438 * extents. so, we trust isize unless the start of the last extent is
4443 last_for_get_extent = isize;
4446 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4449 em = get_extent_skip_holes(inode, start, last_for_get_extent,
4459 u64 offset_in_extent = 0;
4461 /* break if the extent we found is outside the range */
4462 if (em->start >= max || extent_map_end(em) < off)
4466 * get_extent may return an extent that starts before our
4467 * requested range. We have to make sure the ranges
4468 * we return to fiemap always move forward and don't
4469 * overlap, so adjust the offsets here
4471 em_start = max(em->start, off);
4474 * record the offset from the start of the extent
4475 * for adjusting the disk offset below. Only do this if the
4476 * extent isn't compressed since our in ram offset may be past
4477 * what we have actually allocated on disk.
4479 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4480 offset_in_extent = em_start - em->start;
4481 em_end = extent_map_end(em);
4482 em_len = em_end - em_start;
4487 * bump off for our next call to get_extent
4489 off = extent_map_end(em);
4493 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4495 flags |= FIEMAP_EXTENT_LAST;
4496 } else if (em->block_start == EXTENT_MAP_INLINE) {
4497 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4498 FIEMAP_EXTENT_NOT_ALIGNED);
4499 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4500 flags |= (FIEMAP_EXTENT_DELALLOC |
4501 FIEMAP_EXTENT_UNKNOWN);
4502 } else if (fieinfo->fi_extents_max) {
4503 struct btrfs_trans_handle *trans;
4505 u64 bytenr = em->block_start -
4506 (em->start - em->orig_start);
4508 disko = em->block_start + offset_in_extent;
4511 * We need a trans handle to get delayed refs
4513 trans = btrfs_join_transaction(root);
4515 * It's OK if we can't start a trans we can still check
4522 * As btrfs supports shared space, this information
4523 * can be exported to userspace tools via
4524 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4525 * then we're just getting a count and we can skip the
4528 ret = btrfs_check_shared(trans, root->fs_info,
4530 btrfs_ino(BTRFS_I(inode)), bytenr);
4532 btrfs_end_transaction(trans);
4536 flags |= FIEMAP_EXTENT_SHARED;
4539 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4540 flags |= FIEMAP_EXTENT_ENCODED;
4541 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4542 flags |= FIEMAP_EXTENT_UNWRITTEN;
4544 free_extent_map(em);
4546 if ((em_start >= last) || em_len == (u64)-1 ||
4547 (last == (u64)-1 && isize <= em_end)) {
4548 flags |= FIEMAP_EXTENT_LAST;
4552 /* now scan forward to see if this is really the last extent. */
4553 em = get_extent_skip_holes(inode, off, last_for_get_extent,
4560 flags |= FIEMAP_EXTENT_LAST;
4563 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
4572 free_extent_map(em);
4574 btrfs_free_path(path);
4575 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4576 &cached_state, GFP_NOFS);
4580 static void __free_extent_buffer(struct extent_buffer *eb)
4582 btrfs_leak_debug_del(&eb->leak_list);
4583 kmem_cache_free(extent_buffer_cache, eb);
4586 int extent_buffer_under_io(struct extent_buffer *eb)
4588 return (atomic_read(&eb->io_pages) ||
4589 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4590 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4594 * Helper for releasing extent buffer page.
4596 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb)
4598 unsigned long index;
4600 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4602 BUG_ON(extent_buffer_under_io(eb));
4604 index = num_extent_pages(eb->start, eb->len);
4610 page = eb->pages[index];
4614 spin_lock(&page->mapping->private_lock);
4616 * We do this since we'll remove the pages after we've
4617 * removed the eb from the radix tree, so we could race
4618 * and have this page now attached to the new eb. So
4619 * only clear page_private if it's still connected to
4622 if (PagePrivate(page) &&
4623 page->private == (unsigned long)eb) {
4624 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4625 BUG_ON(PageDirty(page));
4626 BUG_ON(PageWriteback(page));
4628 * We need to make sure we haven't be attached
4631 ClearPagePrivate(page);
4632 set_page_private(page, 0);
4633 /* One for the page private */
4638 spin_unlock(&page->mapping->private_lock);
4640 /* One for when we allocated the page */
4642 } while (index != 0);
4646 * Helper for releasing the extent buffer.
4648 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4650 btrfs_release_extent_buffer_page(eb);
4651 __free_extent_buffer(eb);
4654 static struct extent_buffer *
4655 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4658 struct extent_buffer *eb = NULL;
4660 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4663 eb->fs_info = fs_info;
4665 rwlock_init(&eb->lock);
4666 atomic_set(&eb->write_locks, 0);
4667 atomic_set(&eb->read_locks, 0);
4668 atomic_set(&eb->blocking_readers, 0);
4669 atomic_set(&eb->blocking_writers, 0);
4670 atomic_set(&eb->spinning_readers, 0);
4671 atomic_set(&eb->spinning_writers, 0);
4672 eb->lock_nested = 0;
4673 init_waitqueue_head(&eb->write_lock_wq);
4674 init_waitqueue_head(&eb->read_lock_wq);
4676 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4678 spin_lock_init(&eb->refs_lock);
4679 atomic_set(&eb->refs, 1);
4680 atomic_set(&eb->io_pages, 0);
4683 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4685 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4686 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4687 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4692 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4696 struct extent_buffer *new;
4697 unsigned long num_pages = num_extent_pages(src->start, src->len);
4699 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
4703 for (i = 0; i < num_pages; i++) {
4704 p = alloc_page(GFP_NOFS);
4706 btrfs_release_extent_buffer(new);
4709 attach_extent_buffer_page(new, p);
4710 WARN_ON(PageDirty(p));
4713 copy_page(page_address(p), page_address(src->pages[i]));
4716 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4717 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4722 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4723 u64 start, unsigned long len)
4725 struct extent_buffer *eb;
4726 unsigned long num_pages;
4729 num_pages = num_extent_pages(start, len);
4731 eb = __alloc_extent_buffer(fs_info, start, len);
4735 for (i = 0; i < num_pages; i++) {
4736 eb->pages[i] = alloc_page(GFP_NOFS);
4740 set_extent_buffer_uptodate(eb);
4741 btrfs_set_header_nritems(eb, 0);
4742 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4747 __free_page(eb->pages[i - 1]);
4748 __free_extent_buffer(eb);
4752 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4755 return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
4758 static void check_buffer_tree_ref(struct extent_buffer *eb)
4761 /* the ref bit is tricky. We have to make sure it is set
4762 * if we have the buffer dirty. Otherwise the
4763 * code to free a buffer can end up dropping a dirty
4766 * Once the ref bit is set, it won't go away while the
4767 * buffer is dirty or in writeback, and it also won't
4768 * go away while we have the reference count on the
4771 * We can't just set the ref bit without bumping the
4772 * ref on the eb because free_extent_buffer might
4773 * see the ref bit and try to clear it. If this happens
4774 * free_extent_buffer might end up dropping our original
4775 * ref by mistake and freeing the page before we are able
4776 * to add one more ref.
4778 * So bump the ref count first, then set the bit. If someone
4779 * beat us to it, drop the ref we added.
4781 refs = atomic_read(&eb->refs);
4782 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4785 spin_lock(&eb->refs_lock);
4786 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4787 atomic_inc(&eb->refs);
4788 spin_unlock(&eb->refs_lock);
4791 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
4792 struct page *accessed)
4794 unsigned long num_pages, i;
4796 check_buffer_tree_ref(eb);
4798 num_pages = num_extent_pages(eb->start, eb->len);
4799 for (i = 0; i < num_pages; i++) {
4800 struct page *p = eb->pages[i];
4803 mark_page_accessed(p);
4807 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
4810 struct extent_buffer *eb;
4813 eb = radix_tree_lookup(&fs_info->buffer_radix,
4814 start >> PAGE_SHIFT);
4815 if (eb && atomic_inc_not_zero(&eb->refs)) {
4818 * Lock our eb's refs_lock to avoid races with
4819 * free_extent_buffer. When we get our eb it might be flagged
4820 * with EXTENT_BUFFER_STALE and another task running
4821 * free_extent_buffer might have seen that flag set,
4822 * eb->refs == 2, that the buffer isn't under IO (dirty and
4823 * writeback flags not set) and it's still in the tree (flag
4824 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4825 * of decrementing the extent buffer's reference count twice.
4826 * So here we could race and increment the eb's reference count,
4827 * clear its stale flag, mark it as dirty and drop our reference
4828 * before the other task finishes executing free_extent_buffer,
4829 * which would later result in an attempt to free an extent
4830 * buffer that is dirty.
4832 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
4833 spin_lock(&eb->refs_lock);
4834 spin_unlock(&eb->refs_lock);
4836 mark_extent_buffer_accessed(eb, NULL);
4844 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4845 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
4848 struct extent_buffer *eb, *exists = NULL;
4851 eb = find_extent_buffer(fs_info, start);
4854 eb = alloc_dummy_extent_buffer(fs_info, start);
4857 eb->fs_info = fs_info;
4859 ret = radix_tree_preload(GFP_NOFS);
4862 spin_lock(&fs_info->buffer_lock);
4863 ret = radix_tree_insert(&fs_info->buffer_radix,
4864 start >> PAGE_SHIFT, eb);
4865 spin_unlock(&fs_info->buffer_lock);
4866 radix_tree_preload_end();
4867 if (ret == -EEXIST) {
4868 exists = find_extent_buffer(fs_info, start);
4874 check_buffer_tree_ref(eb);
4875 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4878 * We will free dummy extent buffer's if they come into
4879 * free_extent_buffer with a ref count of 2, but if we are using this we
4880 * want the buffers to stay in memory until we're done with them, so
4881 * bump the ref count again.
4883 atomic_inc(&eb->refs);
4886 btrfs_release_extent_buffer(eb);
4891 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
4894 unsigned long len = fs_info->nodesize;
4895 unsigned long num_pages = num_extent_pages(start, len);
4897 unsigned long index = start >> PAGE_SHIFT;
4898 struct extent_buffer *eb;
4899 struct extent_buffer *exists = NULL;
4901 struct address_space *mapping = fs_info->btree_inode->i_mapping;
4905 if (!IS_ALIGNED(start, fs_info->sectorsize)) {
4906 btrfs_err(fs_info, "bad tree block start %llu", start);
4907 return ERR_PTR(-EINVAL);
4910 eb = find_extent_buffer(fs_info, start);
4914 eb = __alloc_extent_buffer(fs_info, start, len);
4916 return ERR_PTR(-ENOMEM);
4918 for (i = 0; i < num_pages; i++, index++) {
4919 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
4921 exists = ERR_PTR(-ENOMEM);
4925 spin_lock(&mapping->private_lock);
4926 if (PagePrivate(p)) {
4928 * We could have already allocated an eb for this page
4929 * and attached one so lets see if we can get a ref on
4930 * the existing eb, and if we can we know it's good and
4931 * we can just return that one, else we know we can just
4932 * overwrite page->private.
4934 exists = (struct extent_buffer *)p->private;
4935 if (atomic_inc_not_zero(&exists->refs)) {
4936 spin_unlock(&mapping->private_lock);
4939 mark_extent_buffer_accessed(exists, p);
4945 * Do this so attach doesn't complain and we need to
4946 * drop the ref the old guy had.
4948 ClearPagePrivate(p);
4949 WARN_ON(PageDirty(p));
4952 attach_extent_buffer_page(eb, p);
4953 spin_unlock(&mapping->private_lock);
4954 WARN_ON(PageDirty(p));
4956 if (!PageUptodate(p))
4960 * see below about how we avoid a nasty race with release page
4961 * and why we unlock later
4965 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4967 ret = radix_tree_preload(GFP_NOFS);
4969 exists = ERR_PTR(ret);
4973 spin_lock(&fs_info->buffer_lock);
4974 ret = radix_tree_insert(&fs_info->buffer_radix,
4975 start >> PAGE_SHIFT, eb);
4976 spin_unlock(&fs_info->buffer_lock);
4977 radix_tree_preload_end();
4978 if (ret == -EEXIST) {
4979 exists = find_extent_buffer(fs_info, start);
4985 /* add one reference for the tree */
4986 check_buffer_tree_ref(eb);
4987 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4990 * there is a race where release page may have
4991 * tried to find this extent buffer in the radix
4992 * but failed. It will tell the VM it is safe to
4993 * reclaim the, and it will clear the page private bit.
4994 * We must make sure to set the page private bit properly
4995 * after the extent buffer is in the radix tree so
4996 * it doesn't get lost
4998 SetPageChecked(eb->pages[0]);
4999 for (i = 1; i < num_pages; i++) {
5001 ClearPageChecked(p);
5004 unlock_page(eb->pages[0]);
5008 WARN_ON(!atomic_dec_and_test(&eb->refs));
5009 for (i = 0; i < num_pages; i++) {
5011 unlock_page(eb->pages[i]);
5014 btrfs_release_extent_buffer(eb);
5018 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5020 struct extent_buffer *eb =
5021 container_of(head, struct extent_buffer, rcu_head);
5023 __free_extent_buffer(eb);
5026 /* Expects to have eb->eb_lock already held */
5027 static int release_extent_buffer(struct extent_buffer *eb)
5029 WARN_ON(atomic_read(&eb->refs) == 0);
5030 if (atomic_dec_and_test(&eb->refs)) {
5031 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5032 struct btrfs_fs_info *fs_info = eb->fs_info;
5034 spin_unlock(&eb->refs_lock);
5036 spin_lock(&fs_info->buffer_lock);
5037 radix_tree_delete(&fs_info->buffer_radix,
5038 eb->start >> PAGE_SHIFT);
5039 spin_unlock(&fs_info->buffer_lock);
5041 spin_unlock(&eb->refs_lock);
5044 /* Should be safe to release our pages at this point */
5045 btrfs_release_extent_buffer_page(eb);
5046 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5047 if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) {
5048 __free_extent_buffer(eb);
5052 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5055 spin_unlock(&eb->refs_lock);
5060 void free_extent_buffer(struct extent_buffer *eb)
5068 refs = atomic_read(&eb->refs);
5071 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5076 spin_lock(&eb->refs_lock);
5077 if (atomic_read(&eb->refs) == 2 &&
5078 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
5079 atomic_dec(&eb->refs);
5081 if (atomic_read(&eb->refs) == 2 &&
5082 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5083 !extent_buffer_under_io(eb) &&
5084 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5085 atomic_dec(&eb->refs);
5088 * I know this is terrible, but it's temporary until we stop tracking
5089 * the uptodate bits and such for the extent buffers.
5091 release_extent_buffer(eb);
5094 void free_extent_buffer_stale(struct extent_buffer *eb)
5099 spin_lock(&eb->refs_lock);
5100 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5102 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5103 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5104 atomic_dec(&eb->refs);
5105 release_extent_buffer(eb);
5108 void clear_extent_buffer_dirty(struct extent_buffer *eb)
5111 unsigned long num_pages;
5114 num_pages = num_extent_pages(eb->start, eb->len);
5116 for (i = 0; i < num_pages; i++) {
5117 page = eb->pages[i];
5118 if (!PageDirty(page))
5122 WARN_ON(!PagePrivate(page));
5124 clear_page_dirty_for_io(page);
5125 spin_lock_irq(&page->mapping->tree_lock);
5126 if (!PageDirty(page)) {
5127 radix_tree_tag_clear(&page->mapping->page_tree,
5129 PAGECACHE_TAG_DIRTY);
5131 spin_unlock_irq(&page->mapping->tree_lock);
5132 ClearPageError(page);
5135 WARN_ON(atomic_read(&eb->refs) == 0);
5138 int set_extent_buffer_dirty(struct extent_buffer *eb)
5141 unsigned long num_pages;
5144 check_buffer_tree_ref(eb);
5146 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5148 num_pages = num_extent_pages(eb->start, eb->len);
5149 WARN_ON(atomic_read(&eb->refs) == 0);
5150 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5152 for (i = 0; i < num_pages; i++)
5153 set_page_dirty(eb->pages[i]);
5157 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5161 unsigned long num_pages;
5163 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5164 num_pages = num_extent_pages(eb->start, eb->len);
5165 for (i = 0; i < num_pages; i++) {
5166 page = eb->pages[i];
5168 ClearPageUptodate(page);
5172 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5176 unsigned long num_pages;
5178 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5179 num_pages = num_extent_pages(eb->start, eb->len);
5180 for (i = 0; i < num_pages; i++) {
5181 page = eb->pages[i];
5182 SetPageUptodate(page);
5186 int extent_buffer_uptodate(struct extent_buffer *eb)
5188 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5191 int read_extent_buffer_pages(struct extent_io_tree *tree,
5192 struct extent_buffer *eb, int wait,
5193 get_extent_t *get_extent, int mirror_num)
5199 int locked_pages = 0;
5200 int all_uptodate = 1;
5201 unsigned long num_pages;
5202 unsigned long num_reads = 0;
5203 struct bio *bio = NULL;
5204 unsigned long bio_flags = 0;
5206 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5209 num_pages = num_extent_pages(eb->start, eb->len);
5210 for (i = 0; i < num_pages; i++) {
5211 page = eb->pages[i];
5212 if (wait == WAIT_NONE) {
5213 if (!trylock_page(page))
5221 * We need to firstly lock all pages to make sure that
5222 * the uptodate bit of our pages won't be affected by
5223 * clear_extent_buffer_uptodate().
5225 for (i = 0; i < num_pages; i++) {
5226 page = eb->pages[i];
5227 if (!PageUptodate(page)) {
5234 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5238 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5239 eb->read_mirror = 0;
5240 atomic_set(&eb->io_pages, num_reads);
5241 for (i = 0; i < num_pages; i++) {
5242 page = eb->pages[i];
5244 if (!PageUptodate(page)) {
5246 atomic_dec(&eb->io_pages);
5251 ClearPageError(page);
5252 err = __extent_read_full_page(tree, page,
5254 mirror_num, &bio_flags,
5259 * We use &bio in above __extent_read_full_page,
5260 * so we ensure that if it returns error, the
5261 * current page fails to add itself to bio and
5262 * it's been unlocked.
5264 * We must dec io_pages by ourselves.
5266 atomic_dec(&eb->io_pages);
5274 err = submit_one_bio(bio, mirror_num, bio_flags);
5279 if (ret || wait != WAIT_COMPLETE)
5282 for (i = 0; i < num_pages; i++) {
5283 page = eb->pages[i];
5284 wait_on_page_locked(page);
5285 if (!PageUptodate(page))
5292 while (locked_pages > 0) {
5294 page = eb->pages[locked_pages];
5300 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
5301 unsigned long start,
5308 char *dst = (char *)dstv;
5309 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5310 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5312 WARN_ON(start > eb->len);
5313 WARN_ON(start + len > eb->start + eb->len);
5315 offset = (start_offset + start) & (PAGE_SIZE - 1);
5318 page = eb->pages[i];
5320 cur = min(len, (PAGE_SIZE - offset));
5321 kaddr = page_address(page);
5322 memcpy(dst, kaddr + offset, cur);
5331 int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv,
5332 unsigned long start,
5339 char __user *dst = (char __user *)dstv;
5340 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5341 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5344 WARN_ON(start > eb->len);
5345 WARN_ON(start + len > eb->start + eb->len);
5347 offset = (start_offset + start) & (PAGE_SIZE - 1);
5350 page = eb->pages[i];
5352 cur = min(len, (PAGE_SIZE - offset));
5353 kaddr = page_address(page);
5354 if (copy_to_user(dst, kaddr + offset, cur)) {
5369 * return 0 if the item is found within a page.
5370 * return 1 if the item spans two pages.
5371 * return -EINVAL otherwise.
5373 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
5374 unsigned long min_len, char **map,
5375 unsigned long *map_start,
5376 unsigned long *map_len)
5378 size_t offset = start & (PAGE_SIZE - 1);
5381 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5382 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5383 unsigned long end_i = (start_offset + start + min_len - 1) >>
5390 offset = start_offset;
5394 *map_start = ((u64)i << PAGE_SHIFT) - start_offset;
5397 if (start + min_len > eb->len) {
5398 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, wanted %lu %lu\n",
5399 eb->start, eb->len, start, min_len);
5404 kaddr = page_address(p);
5405 *map = kaddr + offset;
5406 *map_len = PAGE_SIZE - offset;
5410 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
5411 unsigned long start,
5418 char *ptr = (char *)ptrv;
5419 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5420 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5423 WARN_ON(start > eb->len);
5424 WARN_ON(start + len > eb->start + eb->len);
5426 offset = (start_offset + start) & (PAGE_SIZE - 1);
5429 page = eb->pages[i];
5431 cur = min(len, (PAGE_SIZE - offset));
5433 kaddr = page_address(page);
5434 ret = memcmp(ptr, kaddr + offset, cur);
5446 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
5451 WARN_ON(!PageUptodate(eb->pages[0]));
5452 kaddr = page_address(eb->pages[0]);
5453 memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
5457 void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)
5461 WARN_ON(!PageUptodate(eb->pages[0]));
5462 kaddr = page_address(eb->pages[0]);
5463 memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
5467 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
5468 unsigned long start, unsigned long len)
5474 char *src = (char *)srcv;
5475 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5476 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5478 WARN_ON(start > eb->len);
5479 WARN_ON(start + len > eb->start + eb->len);
5481 offset = (start_offset + start) & (PAGE_SIZE - 1);
5484 page = eb->pages[i];
5485 WARN_ON(!PageUptodate(page));
5487 cur = min(len, PAGE_SIZE - offset);
5488 kaddr = page_address(page);
5489 memcpy(kaddr + offset, src, cur);
5498 void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
5505 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5506 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5508 WARN_ON(start > eb->len);
5509 WARN_ON(start + len > eb->start + eb->len);
5511 offset = (start_offset + start) & (PAGE_SIZE - 1);
5514 page = eb->pages[i];
5515 WARN_ON(!PageUptodate(page));
5517 cur = min(len, PAGE_SIZE - offset);
5518 kaddr = page_address(page);
5519 memset(kaddr + offset, 0, cur);
5527 void copy_extent_buffer_full(struct extent_buffer *dst,
5528 struct extent_buffer *src)
5533 ASSERT(dst->len == src->len);
5535 num_pages = num_extent_pages(dst->start, dst->len);
5536 for (i = 0; i < num_pages; i++)
5537 copy_page(page_address(dst->pages[i]),
5538 page_address(src->pages[i]));
5541 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5542 unsigned long dst_offset, unsigned long src_offset,
5545 u64 dst_len = dst->len;
5550 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5551 unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
5553 WARN_ON(src->len != dst_len);
5555 offset = (start_offset + dst_offset) &
5559 page = dst->pages[i];
5560 WARN_ON(!PageUptodate(page));
5562 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5564 kaddr = page_address(page);
5565 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5574 void le_bitmap_set(u8 *map, unsigned int start, int len)
5576 u8 *p = map + BIT_BYTE(start);
5577 const unsigned int size = start + len;
5578 int bits_to_set = BITS_PER_BYTE - (start % BITS_PER_BYTE);
5579 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(start);
5581 while (len - bits_to_set >= 0) {
5584 bits_to_set = BITS_PER_BYTE;
5589 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5594 void le_bitmap_clear(u8 *map, unsigned int start, int len)
5596 u8 *p = map + BIT_BYTE(start);
5597 const unsigned int size = start + len;
5598 int bits_to_clear = BITS_PER_BYTE - (start % BITS_PER_BYTE);
5599 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(start);
5601 while (len - bits_to_clear >= 0) {
5602 *p &= ~mask_to_clear;
5603 len -= bits_to_clear;
5604 bits_to_clear = BITS_PER_BYTE;
5609 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5610 *p &= ~mask_to_clear;
5615 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5617 * @eb: the extent buffer
5618 * @start: offset of the bitmap item in the extent buffer
5620 * @page_index: return index of the page in the extent buffer that contains the
5622 * @page_offset: return offset into the page given by page_index
5624 * This helper hides the ugliness of finding the byte in an extent buffer which
5625 * contains a given bit.
5627 static inline void eb_bitmap_offset(struct extent_buffer *eb,
5628 unsigned long start, unsigned long nr,
5629 unsigned long *page_index,
5630 size_t *page_offset)
5632 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5633 size_t byte_offset = BIT_BYTE(nr);
5637 * The byte we want is the offset of the extent buffer + the offset of
5638 * the bitmap item in the extent buffer + the offset of the byte in the
5641 offset = start_offset + start + byte_offset;
5643 *page_index = offset >> PAGE_SHIFT;
5644 *page_offset = offset & (PAGE_SIZE - 1);
5648 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5649 * @eb: the extent buffer
5650 * @start: offset of the bitmap item in the extent buffer
5651 * @nr: bit number to test
5653 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
5661 eb_bitmap_offset(eb, start, nr, &i, &offset);
5662 page = eb->pages[i];
5663 WARN_ON(!PageUptodate(page));
5664 kaddr = page_address(page);
5665 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5669 * extent_buffer_bitmap_set - set an area of a bitmap
5670 * @eb: the extent buffer
5671 * @start: offset of the bitmap item in the extent buffer
5672 * @pos: bit number of the first bit
5673 * @len: number of bits to set
5675 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
5676 unsigned long pos, unsigned long len)
5682 const unsigned int size = pos + len;
5683 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5684 u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5686 eb_bitmap_offset(eb, start, pos, &i, &offset);
5687 page = eb->pages[i];
5688 WARN_ON(!PageUptodate(page));
5689 kaddr = page_address(page);
5691 while (len >= bits_to_set) {
5692 kaddr[offset] |= mask_to_set;
5694 bits_to_set = BITS_PER_BYTE;
5696 if (++offset >= PAGE_SIZE && len > 0) {
5698 page = eb->pages[++i];
5699 WARN_ON(!PageUptodate(page));
5700 kaddr = page_address(page);
5704 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5705 kaddr[offset] |= mask_to_set;
5711 * extent_buffer_bitmap_clear - clear an area of a bitmap
5712 * @eb: the extent buffer
5713 * @start: offset of the bitmap item in the extent buffer
5714 * @pos: bit number of the first bit
5715 * @len: number of bits to clear
5717 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
5718 unsigned long pos, unsigned long len)
5724 const unsigned int size = pos + len;
5725 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5726 u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5728 eb_bitmap_offset(eb, start, pos, &i, &offset);
5729 page = eb->pages[i];
5730 WARN_ON(!PageUptodate(page));
5731 kaddr = page_address(page);
5733 while (len >= bits_to_clear) {
5734 kaddr[offset] &= ~mask_to_clear;
5735 len -= bits_to_clear;
5736 bits_to_clear = BITS_PER_BYTE;
5738 if (++offset >= PAGE_SIZE && len > 0) {
5740 page = eb->pages[++i];
5741 WARN_ON(!PageUptodate(page));
5742 kaddr = page_address(page);
5746 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5747 kaddr[offset] &= ~mask_to_clear;
5751 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5753 unsigned long distance = (src > dst) ? src - dst : dst - src;
5754 return distance < len;
5757 static void copy_pages(struct page *dst_page, struct page *src_page,
5758 unsigned long dst_off, unsigned long src_off,
5761 char *dst_kaddr = page_address(dst_page);
5763 int must_memmove = 0;
5765 if (dst_page != src_page) {
5766 src_kaddr = page_address(src_page);
5768 src_kaddr = dst_kaddr;
5769 if (areas_overlap(src_off, dst_off, len))
5774 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5776 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5779 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5780 unsigned long src_offset, unsigned long len)
5782 struct btrfs_fs_info *fs_info = dst->fs_info;
5784 size_t dst_off_in_page;
5785 size_t src_off_in_page;
5786 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5787 unsigned long dst_i;
5788 unsigned long src_i;
5790 if (src_offset + len > dst->len) {
5792 "memmove bogus src_offset %lu move len %lu dst len %lu",
5793 src_offset, len, dst->len);
5796 if (dst_offset + len > dst->len) {
5798 "memmove bogus dst_offset %lu move len %lu dst len %lu",
5799 dst_offset, len, dst->len);
5804 dst_off_in_page = (start_offset + dst_offset) &
5806 src_off_in_page = (start_offset + src_offset) &
5809 dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
5810 src_i = (start_offset + src_offset) >> PAGE_SHIFT;
5812 cur = min(len, (unsigned long)(PAGE_SIZE -
5814 cur = min_t(unsigned long, cur,
5815 (unsigned long)(PAGE_SIZE - dst_off_in_page));
5817 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5818 dst_off_in_page, src_off_in_page, cur);
5826 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5827 unsigned long src_offset, unsigned long len)
5829 struct btrfs_fs_info *fs_info = dst->fs_info;
5831 size_t dst_off_in_page;
5832 size_t src_off_in_page;
5833 unsigned long dst_end = dst_offset + len - 1;
5834 unsigned long src_end = src_offset + len - 1;
5835 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5836 unsigned long dst_i;
5837 unsigned long src_i;
5839 if (src_offset + len > dst->len) {
5841 "memmove bogus src_offset %lu move len %lu len %lu",
5842 src_offset, len, dst->len);
5845 if (dst_offset + len > dst->len) {
5847 "memmove bogus dst_offset %lu move len %lu len %lu",
5848 dst_offset, len, dst->len);
5851 if (dst_offset < src_offset) {
5852 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5856 dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
5857 src_i = (start_offset + src_end) >> PAGE_SHIFT;
5859 dst_off_in_page = (start_offset + dst_end) &
5861 src_off_in_page = (start_offset + src_end) &
5864 cur = min_t(unsigned long, len, src_off_in_page + 1);
5865 cur = min(cur, dst_off_in_page + 1);
5866 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5867 dst_off_in_page - cur + 1,
5868 src_off_in_page - cur + 1, cur);
5876 int try_release_extent_buffer(struct page *page)
5878 struct extent_buffer *eb;
5881 * We need to make sure nobody is attaching this page to an eb right
5884 spin_lock(&page->mapping->private_lock);
5885 if (!PagePrivate(page)) {
5886 spin_unlock(&page->mapping->private_lock);
5890 eb = (struct extent_buffer *)page->private;
5894 * This is a little awful but should be ok, we need to make sure that
5895 * the eb doesn't disappear out from under us while we're looking at
5898 spin_lock(&eb->refs_lock);
5899 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5900 spin_unlock(&eb->refs_lock);
5901 spin_unlock(&page->mapping->private_lock);
5904 spin_unlock(&page->mapping->private_lock);
5907 * If tree ref isn't set then we know the ref on this eb is a real ref,
5908 * so just return, this page will likely be freed soon anyway.
5910 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5911 spin_unlock(&eb->refs_lock);
5915 return release_extent_buffer(eb);