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"
24 static struct kmem_cache *extent_state_cache;
25 static struct kmem_cache *extent_buffer_cache;
26 static struct bio_set *btrfs_bioset;
28 static inline bool extent_state_in_tree(const struct extent_state *state)
30 return !RB_EMPTY_NODE(&state->rb_node);
33 #ifdef CONFIG_BTRFS_DEBUG
34 static LIST_HEAD(buffers);
35 static LIST_HEAD(states);
37 static DEFINE_SPINLOCK(leak_lock);
40 void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
44 spin_lock_irqsave(&leak_lock, flags);
46 spin_unlock_irqrestore(&leak_lock, flags);
50 void btrfs_leak_debug_del(struct list_head *entry)
54 spin_lock_irqsave(&leak_lock, flags);
56 spin_unlock_irqrestore(&leak_lock, flags);
60 void btrfs_leak_debug_check(void)
62 struct extent_state *state;
63 struct extent_buffer *eb;
65 while (!list_empty(&states)) {
66 state = list_entry(states.next, struct extent_state, leak_list);
67 pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
68 state->start, state->end, state->state,
69 extent_state_in_tree(state),
70 atomic_read(&state->refs));
71 list_del(&state->leak_list);
72 kmem_cache_free(extent_state_cache, state);
75 while (!list_empty(&buffers)) {
76 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
77 printk(KERN_ERR "BTRFS: buffer leak start %llu len %lu "
79 eb->start, eb->len, atomic_read(&eb->refs));
80 list_del(&eb->leak_list);
81 kmem_cache_free(extent_buffer_cache, eb);
85 #define btrfs_debug_check_extent_io_range(tree, start, end) \
86 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
87 static inline void __btrfs_debug_check_extent_io_range(const char *caller,
88 struct extent_io_tree *tree, u64 start, u64 end)
96 inode = tree->mapping->host;
97 isize = i_size_read(inode);
98 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
99 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
100 "%s: ino %llu isize %llu odd range [%llu,%llu]",
101 caller, btrfs_ino(inode), isize, start, end);
105 #define btrfs_leak_debug_add(new, head) do {} while (0)
106 #define btrfs_leak_debug_del(entry) do {} while (0)
107 #define btrfs_leak_debug_check() do {} while (0)
108 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
111 #define BUFFER_LRU_MAX 64
116 struct rb_node rb_node;
119 struct extent_page_data {
121 struct extent_io_tree *tree;
122 get_extent_t *get_extent;
123 unsigned long bio_flags;
125 /* tells writepage not to lock the state bits for this range
126 * it still does the unlocking
128 unsigned int extent_locked:1;
130 /* tells the submit_bio code to use a WRITE_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_RECLAIM_ACCOUNT | 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_RECLAIM_ACCOUNT | 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;
229 state = kmem_cache_alloc(extent_state_cache, mask);
233 state->failrec = NULL;
234 RB_CLEAR_NODE(&state->rb_node);
235 btrfs_leak_debug_add(&state->leak_list, &states);
236 atomic_set(&state->refs, 1);
237 init_waitqueue_head(&state->wq);
238 trace_alloc_extent_state(state, mask, _RET_IP_);
242 void free_extent_state(struct extent_state *state)
246 if (atomic_dec_and_test(&state->refs)) {
247 WARN_ON(extent_state_in_tree(state));
248 btrfs_leak_debug_del(&state->leak_list);
249 trace_free_extent_state(state, _RET_IP_);
250 kmem_cache_free(extent_state_cache, state);
254 static struct rb_node *tree_insert(struct rb_root *root,
255 struct rb_node *search_start,
257 struct rb_node *node,
258 struct rb_node ***p_in,
259 struct rb_node **parent_in)
262 struct rb_node *parent = NULL;
263 struct tree_entry *entry;
265 if (p_in && parent_in) {
271 p = search_start ? &search_start : &root->rb_node;
274 entry = rb_entry(parent, struct tree_entry, rb_node);
276 if (offset < entry->start)
278 else if (offset > entry->end)
285 rb_link_node(node, parent, p);
286 rb_insert_color(node, root);
290 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
291 struct rb_node **prev_ret,
292 struct rb_node **next_ret,
293 struct rb_node ***p_ret,
294 struct rb_node **parent_ret)
296 struct rb_root *root = &tree->state;
297 struct rb_node **n = &root->rb_node;
298 struct rb_node *prev = NULL;
299 struct rb_node *orig_prev = NULL;
300 struct tree_entry *entry;
301 struct tree_entry *prev_entry = NULL;
305 entry = rb_entry(prev, struct tree_entry, rb_node);
308 if (offset < entry->start)
310 else if (offset > entry->end)
323 while (prev && offset > prev_entry->end) {
324 prev = rb_next(prev);
325 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
332 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
333 while (prev && offset < prev_entry->start) {
334 prev = rb_prev(prev);
335 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
342 static inline struct rb_node *
343 tree_search_for_insert(struct extent_io_tree *tree,
345 struct rb_node ***p_ret,
346 struct rb_node **parent_ret)
348 struct rb_node *prev = NULL;
351 ret = __etree_search(tree, offset, &prev, NULL, p_ret, parent_ret);
357 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
360 return tree_search_for_insert(tree, offset, NULL, NULL);
363 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
364 struct extent_state *other)
366 if (tree->ops && tree->ops->merge_extent_hook)
367 tree->ops->merge_extent_hook(tree->mapping->host, new,
372 * utility function to look for merge candidates inside a given range.
373 * Any extents with matching state are merged together into a single
374 * extent in the tree. Extents with EXTENT_IO in their state field
375 * are not merged because the end_io handlers need to be able to do
376 * operations on them without sleeping (or doing allocations/splits).
378 * This should be called with the tree lock held.
380 static void merge_state(struct extent_io_tree *tree,
381 struct extent_state *state)
383 struct extent_state *other;
384 struct rb_node *other_node;
386 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
389 other_node = rb_prev(&state->rb_node);
391 other = rb_entry(other_node, struct extent_state, rb_node);
392 if (other->end == state->start - 1 &&
393 other->state == state->state) {
394 merge_cb(tree, state, other);
395 state->start = other->start;
396 rb_erase(&other->rb_node, &tree->state);
397 RB_CLEAR_NODE(&other->rb_node);
398 free_extent_state(other);
401 other_node = rb_next(&state->rb_node);
403 other = rb_entry(other_node, struct extent_state, rb_node);
404 if (other->start == state->end + 1 &&
405 other->state == state->state) {
406 merge_cb(tree, state, other);
407 state->end = other->end;
408 rb_erase(&other->rb_node, &tree->state);
409 RB_CLEAR_NODE(&other->rb_node);
410 free_extent_state(other);
415 static void set_state_cb(struct extent_io_tree *tree,
416 struct extent_state *state, unsigned *bits)
418 if (tree->ops && tree->ops->set_bit_hook)
419 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
422 static void clear_state_cb(struct extent_io_tree *tree,
423 struct extent_state *state, unsigned *bits)
425 if (tree->ops && tree->ops->clear_bit_hook)
426 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
429 static void set_state_bits(struct extent_io_tree *tree,
430 struct extent_state *state, unsigned *bits,
431 struct extent_changeset *changeset);
434 * insert an extent_state struct into the tree. 'bits' are set on the
435 * struct before it is inserted.
437 * This may return -EEXIST if the extent is already there, in which case the
438 * state struct is freed.
440 * The tree lock is not taken internally. This is a utility function and
441 * probably isn't what you want to call (see set/clear_extent_bit).
443 static int insert_state(struct extent_io_tree *tree,
444 struct extent_state *state, u64 start, u64 end,
446 struct rb_node **parent,
447 unsigned *bits, struct extent_changeset *changeset)
449 struct rb_node *node;
452 WARN(1, KERN_ERR "BTRFS: end < start %llu %llu\n",
454 state->start = start;
457 set_state_bits(tree, state, bits, changeset);
459 node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
461 struct extent_state *found;
462 found = rb_entry(node, struct extent_state, rb_node);
463 printk(KERN_ERR "BTRFS: found node %llu %llu on insert of "
465 found->start, found->end, start, end);
468 merge_state(tree, state);
472 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
475 if (tree->ops && tree->ops->split_extent_hook)
476 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
480 * split a given extent state struct in two, inserting the preallocated
481 * struct 'prealloc' as the newly created second half. 'split' indicates an
482 * offset inside 'orig' where it should be split.
485 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
486 * are two extent state structs in the tree:
487 * prealloc: [orig->start, split - 1]
488 * orig: [ split, orig->end ]
490 * The tree locks are not taken by this function. They need to be held
493 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
494 struct extent_state *prealloc, u64 split)
496 struct rb_node *node;
498 split_cb(tree, orig, split);
500 prealloc->start = orig->start;
501 prealloc->end = split - 1;
502 prealloc->state = orig->state;
505 node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
506 &prealloc->rb_node, NULL, NULL);
508 free_extent_state(prealloc);
514 static struct extent_state *next_state(struct extent_state *state)
516 struct rb_node *next = rb_next(&state->rb_node);
518 return rb_entry(next, struct extent_state, rb_node);
524 * utility function to clear some bits in an extent state struct.
525 * it will optionally wake up any one waiting on this state (wake == 1).
527 * If no bits are set on the state struct after clearing things, the
528 * struct is freed and removed from the tree
530 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
531 struct extent_state *state,
532 unsigned *bits, int wake,
533 struct extent_changeset *changeset)
535 struct extent_state *next;
536 unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
538 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
539 u64 range = state->end - state->start + 1;
540 WARN_ON(range > tree->dirty_bytes);
541 tree->dirty_bytes -= range;
543 clear_state_cb(tree, state, bits);
544 add_extent_changeset(state, bits_to_clear, changeset, 0);
545 state->state &= ~bits_to_clear;
548 if (state->state == 0) {
549 next = next_state(state);
550 if (extent_state_in_tree(state)) {
551 rb_erase(&state->rb_node, &tree->state);
552 RB_CLEAR_NODE(&state->rb_node);
553 free_extent_state(state);
558 merge_state(tree, state);
559 next = next_state(state);
564 static struct extent_state *
565 alloc_extent_state_atomic(struct extent_state *prealloc)
568 prealloc = alloc_extent_state(GFP_ATOMIC);
573 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
575 btrfs_panic(tree_fs_info(tree), err, "Locking error: "
576 "Extent tree was modified by another "
577 "thread while locked.");
581 * clear some bits on a range in the tree. This may require splitting
582 * or inserting elements in the tree, so the gfp mask is used to
583 * indicate which allocations or sleeping are allowed.
585 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
586 * the given range from the tree regardless of state (ie for truncate).
588 * the range [start, end] is inclusive.
590 * This takes the tree lock, and returns 0 on success and < 0 on error.
592 static int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
593 unsigned bits, int wake, int delete,
594 struct extent_state **cached_state,
595 gfp_t mask, struct extent_changeset *changeset)
597 struct extent_state *state;
598 struct extent_state *cached;
599 struct extent_state *prealloc = NULL;
600 struct rb_node *node;
605 btrfs_debug_check_extent_io_range(tree, start, end);
607 if (bits & EXTENT_DELALLOC)
608 bits |= EXTENT_NORESERVE;
611 bits |= ~EXTENT_CTLBITS;
612 bits |= EXTENT_FIRST_DELALLOC;
614 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
617 if (!prealloc && gfpflags_allow_blocking(mask)) {
619 * Don't care for allocation failure here because we might end
620 * up not needing the pre-allocated extent state at all, which
621 * is the case if we only have in the tree extent states that
622 * cover our input range and don't cover too any other range.
623 * If we end up needing a new extent state we allocate it later.
625 prealloc = alloc_extent_state(mask);
628 spin_lock(&tree->lock);
630 cached = *cached_state;
633 *cached_state = NULL;
637 if (cached && extent_state_in_tree(cached) &&
638 cached->start <= start && cached->end > start) {
640 atomic_dec(&cached->refs);
645 free_extent_state(cached);
648 * this search will find the extents that end after
651 node = tree_search(tree, start);
654 state = rb_entry(node, struct extent_state, rb_node);
656 if (state->start > end)
658 WARN_ON(state->end < start);
659 last_end = state->end;
661 /* the state doesn't have the wanted bits, go ahead */
662 if (!(state->state & bits)) {
663 state = next_state(state);
668 * | ---- desired range ---- |
670 * | ------------- state -------------- |
672 * We need to split the extent we found, and may flip
673 * bits on second half.
675 * If the extent we found extends past our range, we
676 * just split and search again. It'll get split again
677 * the next time though.
679 * If the extent we found is inside our range, we clear
680 * the desired bit on it.
683 if (state->start < start) {
684 prealloc = alloc_extent_state_atomic(prealloc);
686 err = split_state(tree, state, prealloc, start);
688 extent_io_tree_panic(tree, err);
693 if (state->end <= end) {
694 state = clear_state_bit(tree, state, &bits, wake,
701 * | ---- desired range ---- |
703 * We need to split the extent, and clear the bit
706 if (state->start <= end && state->end > end) {
707 prealloc = alloc_extent_state_atomic(prealloc);
709 err = split_state(tree, state, prealloc, end + 1);
711 extent_io_tree_panic(tree, err);
716 clear_state_bit(tree, prealloc, &bits, wake, changeset);
722 state = clear_state_bit(tree, state, &bits, wake, changeset);
724 if (last_end == (u64)-1)
726 start = last_end + 1;
727 if (start <= end && state && !need_resched())
732 spin_unlock(&tree->lock);
734 free_extent_state(prealloc);
741 spin_unlock(&tree->lock);
742 if (gfpflags_allow_blocking(mask))
747 static void wait_on_state(struct extent_io_tree *tree,
748 struct extent_state *state)
749 __releases(tree->lock)
750 __acquires(tree->lock)
753 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
754 spin_unlock(&tree->lock);
756 spin_lock(&tree->lock);
757 finish_wait(&state->wq, &wait);
761 * waits for one or more bits to clear on a range in the state tree.
762 * The range [start, end] is inclusive.
763 * The tree lock is taken by this function
765 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
768 struct extent_state *state;
769 struct rb_node *node;
771 btrfs_debug_check_extent_io_range(tree, start, end);
773 spin_lock(&tree->lock);
777 * this search will find all the extents that end after
780 node = tree_search(tree, start);
785 state = rb_entry(node, struct extent_state, rb_node);
787 if (state->start > end)
790 if (state->state & bits) {
791 start = state->start;
792 atomic_inc(&state->refs);
793 wait_on_state(tree, state);
794 free_extent_state(state);
797 start = state->end + 1;
802 if (!cond_resched_lock(&tree->lock)) {
803 node = rb_next(node);
808 spin_unlock(&tree->lock);
811 static void set_state_bits(struct extent_io_tree *tree,
812 struct extent_state *state,
813 unsigned *bits, struct extent_changeset *changeset)
815 unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
817 set_state_cb(tree, state, bits);
818 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
819 u64 range = state->end - state->start + 1;
820 tree->dirty_bytes += range;
822 add_extent_changeset(state, bits_to_set, changeset, 1);
823 state->state |= bits_to_set;
826 static void cache_state_if_flags(struct extent_state *state,
827 struct extent_state **cached_ptr,
830 if (cached_ptr && !(*cached_ptr)) {
831 if (!flags || (state->state & flags)) {
833 atomic_inc(&state->refs);
838 static void cache_state(struct extent_state *state,
839 struct extent_state **cached_ptr)
841 return cache_state_if_flags(state, cached_ptr,
842 EXTENT_IOBITS | EXTENT_BOUNDARY);
846 * set some bits on a range in the tree. This may require allocations or
847 * sleeping, so the gfp mask is used to indicate what is allowed.
849 * If any of the exclusive bits are set, this will fail with -EEXIST if some
850 * part of the range already has the desired bits set. The start of the
851 * existing range is returned in failed_start in this case.
853 * [start, end] is inclusive This takes the tree lock.
856 static int __must_check
857 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
858 unsigned bits, unsigned exclusive_bits,
859 u64 *failed_start, struct extent_state **cached_state,
860 gfp_t mask, struct extent_changeset *changeset)
862 struct extent_state *state;
863 struct extent_state *prealloc = NULL;
864 struct rb_node *node;
866 struct rb_node *parent;
871 btrfs_debug_check_extent_io_range(tree, start, end);
873 bits |= EXTENT_FIRST_DELALLOC;
875 if (!prealloc && gfpflags_allow_blocking(mask)) {
876 prealloc = alloc_extent_state(mask);
880 spin_lock(&tree->lock);
881 if (cached_state && *cached_state) {
882 state = *cached_state;
883 if (state->start <= start && state->end > start &&
884 extent_state_in_tree(state)) {
885 node = &state->rb_node;
890 * this search will find all the extents that end after
893 node = tree_search_for_insert(tree, start, &p, &parent);
895 prealloc = alloc_extent_state_atomic(prealloc);
897 err = insert_state(tree, prealloc, start, end,
898 &p, &parent, &bits, changeset);
900 extent_io_tree_panic(tree, err);
902 cache_state(prealloc, cached_state);
906 state = rb_entry(node, struct extent_state, rb_node);
908 last_start = state->start;
909 last_end = state->end;
912 * | ---- desired range ---- |
915 * Just lock what we found and keep going
917 if (state->start == start && state->end <= end) {
918 if (state->state & exclusive_bits) {
919 *failed_start = state->start;
924 set_state_bits(tree, state, &bits, changeset);
925 cache_state(state, cached_state);
926 merge_state(tree, state);
927 if (last_end == (u64)-1)
929 start = last_end + 1;
930 state = next_state(state);
931 if (start < end && state && state->start == start &&
938 * | ---- desired range ---- |
941 * | ------------- state -------------- |
943 * We need to split the extent we found, and may flip bits on
946 * If the extent we found extends past our
947 * range, we just split and search again. It'll get split
948 * again the next time though.
950 * If the extent we found is inside our range, we set the
953 if (state->start < start) {
954 if (state->state & exclusive_bits) {
955 *failed_start = start;
960 prealloc = alloc_extent_state_atomic(prealloc);
962 err = split_state(tree, state, prealloc, start);
964 extent_io_tree_panic(tree, err);
969 if (state->end <= end) {
970 set_state_bits(tree, state, &bits, changeset);
971 cache_state(state, cached_state);
972 merge_state(tree, state);
973 if (last_end == (u64)-1)
975 start = last_end + 1;
976 state = next_state(state);
977 if (start < end && state && state->start == start &&
984 * | ---- desired range ---- |
985 * | state | or | state |
987 * There's a hole, we need to insert something in it and
988 * ignore the extent we found.
990 if (state->start > start) {
992 if (end < last_start)
995 this_end = last_start - 1;
997 prealloc = alloc_extent_state_atomic(prealloc);
1001 * Avoid to free 'prealloc' if it can be merged with
1004 err = insert_state(tree, prealloc, start, this_end,
1005 NULL, NULL, &bits, changeset);
1007 extent_io_tree_panic(tree, err);
1009 cache_state(prealloc, cached_state);
1011 start = this_end + 1;
1015 * | ---- desired range ---- |
1017 * We need to split the extent, and set the bit
1020 if (state->start <= end && state->end > end) {
1021 if (state->state & exclusive_bits) {
1022 *failed_start = start;
1027 prealloc = alloc_extent_state_atomic(prealloc);
1029 err = split_state(tree, state, prealloc, end + 1);
1031 extent_io_tree_panic(tree, err);
1033 set_state_bits(tree, prealloc, &bits, changeset);
1034 cache_state(prealloc, cached_state);
1035 merge_state(tree, prealloc);
1043 spin_unlock(&tree->lock);
1045 free_extent_state(prealloc);
1052 spin_unlock(&tree->lock);
1053 if (gfpflags_allow_blocking(mask))
1058 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1059 unsigned bits, u64 * failed_start,
1060 struct extent_state **cached_state, gfp_t mask)
1062 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
1063 cached_state, mask, NULL);
1068 * convert_extent_bit - convert all bits in a given range from one bit to
1070 * @tree: the io tree to search
1071 * @start: the start offset in bytes
1072 * @end: the end offset in bytes (inclusive)
1073 * @bits: the bits to set in this range
1074 * @clear_bits: the bits to clear in this range
1075 * @cached_state: state that we're going to cache
1076 * @mask: the allocation mask
1078 * This will go through and set bits for the given range. If any states exist
1079 * already in this range they are set with the given bit and cleared of the
1080 * clear_bits. This is only meant to be used by things that are mergeable, ie
1081 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1082 * boundary bits like LOCK.
1084 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1085 unsigned bits, unsigned clear_bits,
1086 struct extent_state **cached_state, gfp_t mask)
1088 struct extent_state *state;
1089 struct extent_state *prealloc = NULL;
1090 struct rb_node *node;
1092 struct rb_node *parent;
1096 bool first_iteration = true;
1098 btrfs_debug_check_extent_io_range(tree, start, end);
1101 if (!prealloc && gfpflags_allow_blocking(mask)) {
1103 * Best effort, don't worry if extent state allocation fails
1104 * here for the first iteration. We might have a cached state
1105 * that matches exactly the target range, in which case no
1106 * extent state allocations are needed. We'll only know this
1107 * after locking the tree.
1109 prealloc = alloc_extent_state(mask);
1110 if (!prealloc && !first_iteration)
1114 spin_lock(&tree->lock);
1115 if (cached_state && *cached_state) {
1116 state = *cached_state;
1117 if (state->start <= start && state->end > start &&
1118 extent_state_in_tree(state)) {
1119 node = &state->rb_node;
1125 * this search will find all the extents that end after
1128 node = tree_search_for_insert(tree, start, &p, &parent);
1130 prealloc = alloc_extent_state_atomic(prealloc);
1135 err = insert_state(tree, prealloc, start, end,
1136 &p, &parent, &bits, NULL);
1138 extent_io_tree_panic(tree, err);
1139 cache_state(prealloc, cached_state);
1143 state = rb_entry(node, struct extent_state, rb_node);
1145 last_start = state->start;
1146 last_end = state->end;
1149 * | ---- desired range ---- |
1152 * Just lock what we found and keep going
1154 if (state->start == start && state->end <= end) {
1155 set_state_bits(tree, state, &bits, NULL);
1156 cache_state(state, cached_state);
1157 state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
1158 if (last_end == (u64)-1)
1160 start = last_end + 1;
1161 if (start < end && state && state->start == start &&
1168 * | ---- desired range ---- |
1171 * | ------------- state -------------- |
1173 * We need to split the extent we found, and may flip bits on
1176 * If the extent we found extends past our
1177 * range, we just split and search again. It'll get split
1178 * again the next time though.
1180 * If the extent we found is inside our range, we set the
1181 * desired bit on it.
1183 if (state->start < start) {
1184 prealloc = alloc_extent_state_atomic(prealloc);
1189 err = split_state(tree, state, prealloc, start);
1191 extent_io_tree_panic(tree, err);
1195 if (state->end <= end) {
1196 set_state_bits(tree, state, &bits, NULL);
1197 cache_state(state, cached_state);
1198 state = clear_state_bit(tree, state, &clear_bits, 0,
1200 if (last_end == (u64)-1)
1202 start = last_end + 1;
1203 if (start < end && state && state->start == start &&
1210 * | ---- desired range ---- |
1211 * | state | or | state |
1213 * There's a hole, we need to insert something in it and
1214 * ignore the extent we found.
1216 if (state->start > start) {
1218 if (end < last_start)
1221 this_end = last_start - 1;
1223 prealloc = alloc_extent_state_atomic(prealloc);
1230 * Avoid to free 'prealloc' if it can be merged with
1233 err = insert_state(tree, prealloc, start, this_end,
1234 NULL, NULL, &bits, NULL);
1236 extent_io_tree_panic(tree, err);
1237 cache_state(prealloc, cached_state);
1239 start = this_end + 1;
1243 * | ---- desired range ---- |
1245 * We need to split the extent, and set the bit
1248 if (state->start <= end && state->end > end) {
1249 prealloc = alloc_extent_state_atomic(prealloc);
1255 err = split_state(tree, state, prealloc, end + 1);
1257 extent_io_tree_panic(tree, err);
1259 set_state_bits(tree, prealloc, &bits, NULL);
1260 cache_state(prealloc, cached_state);
1261 clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
1269 spin_unlock(&tree->lock);
1271 free_extent_state(prealloc);
1278 spin_unlock(&tree->lock);
1279 if (gfpflags_allow_blocking(mask))
1281 first_iteration = false;
1285 /* wrappers around set/clear extent bit */
1286 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1287 unsigned bits, gfp_t mask,
1288 struct extent_changeset *changeset)
1291 * We don't support EXTENT_LOCKED yet, as current changeset will
1292 * record any bits changed, so for EXTENT_LOCKED case, it will
1293 * either fail with -EEXIST or changeset will record the whole
1296 BUG_ON(bits & EXTENT_LOCKED);
1298 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, mask,
1302 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1303 unsigned bits, int wake, int delete,
1304 struct extent_state **cached, gfp_t mask)
1306 return __clear_extent_bit(tree, start, end, bits, wake, delete,
1307 cached, mask, NULL);
1310 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1311 unsigned bits, gfp_t mask,
1312 struct extent_changeset *changeset)
1315 * Don't support EXTENT_LOCKED case, same reason as
1316 * set_record_extent_bits().
1318 BUG_ON(bits & EXTENT_LOCKED);
1320 return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask,
1325 * either insert or lock state struct between start and end use mask to tell
1326 * us if waiting is desired.
1328 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1329 struct extent_state **cached_state)
1335 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
1336 EXTENT_LOCKED, &failed_start,
1337 cached_state, GFP_NOFS, NULL);
1338 if (err == -EEXIST) {
1339 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1340 start = failed_start;
1343 WARN_ON(start > end);
1348 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1353 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1354 &failed_start, NULL, GFP_NOFS, NULL);
1355 if (err == -EEXIST) {
1356 if (failed_start > start)
1357 clear_extent_bit(tree, start, failed_start - 1,
1358 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
1364 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1366 unsigned long index = start >> PAGE_SHIFT;
1367 unsigned long end_index = end >> PAGE_SHIFT;
1370 while (index <= end_index) {
1371 page = find_get_page(inode->i_mapping, index);
1372 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1373 clear_page_dirty_for_io(page);
1379 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1381 unsigned long index = start >> PAGE_SHIFT;
1382 unsigned long end_index = end >> PAGE_SHIFT;
1385 while (index <= end_index) {
1386 page = find_get_page(inode->i_mapping, index);
1387 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1388 __set_page_dirty_nobuffers(page);
1389 account_page_redirty(page);
1396 * helper function to set both pages and extents in the tree writeback
1398 static void set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1400 unsigned long index = start >> PAGE_SHIFT;
1401 unsigned long end_index = end >> PAGE_SHIFT;
1404 while (index <= end_index) {
1405 page = find_get_page(tree->mapping, index);
1406 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1407 set_page_writeback(page);
1413 /* find the first state struct with 'bits' set after 'start', and
1414 * return it. tree->lock must be held. NULL will returned if
1415 * nothing was found after 'start'
1417 static struct extent_state *
1418 find_first_extent_bit_state(struct extent_io_tree *tree,
1419 u64 start, unsigned bits)
1421 struct rb_node *node;
1422 struct extent_state *state;
1425 * this search will find all the extents that end after
1428 node = tree_search(tree, start);
1433 state = rb_entry(node, struct extent_state, rb_node);
1434 if (state->end >= start && (state->state & bits))
1437 node = rb_next(node);
1446 * find the first offset in the io tree with 'bits' set. zero is
1447 * returned if we find something, and *start_ret and *end_ret are
1448 * set to reflect the state struct that was found.
1450 * If nothing was found, 1 is returned. If found something, return 0.
1452 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1453 u64 *start_ret, u64 *end_ret, unsigned bits,
1454 struct extent_state **cached_state)
1456 struct extent_state *state;
1460 spin_lock(&tree->lock);
1461 if (cached_state && *cached_state) {
1462 state = *cached_state;
1463 if (state->end == start - 1 && extent_state_in_tree(state)) {
1464 n = rb_next(&state->rb_node);
1466 state = rb_entry(n, struct extent_state,
1468 if (state->state & bits)
1472 free_extent_state(*cached_state);
1473 *cached_state = NULL;
1476 free_extent_state(*cached_state);
1477 *cached_state = NULL;
1480 state = find_first_extent_bit_state(tree, start, bits);
1483 cache_state_if_flags(state, cached_state, 0);
1484 *start_ret = state->start;
1485 *end_ret = state->end;
1489 spin_unlock(&tree->lock);
1494 * find a contiguous range of bytes in the file marked as delalloc, not
1495 * more than 'max_bytes'. start and end are used to return the range,
1497 * 1 is returned if we find something, 0 if nothing was in the tree
1499 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1500 u64 *start, u64 *end, u64 max_bytes,
1501 struct extent_state **cached_state)
1503 struct rb_node *node;
1504 struct extent_state *state;
1505 u64 cur_start = *start;
1507 u64 total_bytes = 0;
1509 spin_lock(&tree->lock);
1512 * this search will find all the extents that end after
1515 node = tree_search(tree, cur_start);
1523 state = rb_entry(node, struct extent_state, rb_node);
1524 if (found && (state->start != cur_start ||
1525 (state->state & EXTENT_BOUNDARY))) {
1528 if (!(state->state & EXTENT_DELALLOC)) {
1534 *start = state->start;
1535 *cached_state = state;
1536 atomic_inc(&state->refs);
1540 cur_start = state->end + 1;
1541 node = rb_next(node);
1542 total_bytes += state->end - state->start + 1;
1543 if (total_bytes >= max_bytes)
1549 spin_unlock(&tree->lock);
1553 static noinline void __unlock_for_delalloc(struct inode *inode,
1554 struct page *locked_page,
1558 struct page *pages[16];
1559 unsigned long index = start >> PAGE_SHIFT;
1560 unsigned long end_index = end >> PAGE_SHIFT;
1561 unsigned long nr_pages = end_index - index + 1;
1564 if (index == locked_page->index && end_index == index)
1567 while (nr_pages > 0) {
1568 ret = find_get_pages_contig(inode->i_mapping, index,
1569 min_t(unsigned long, nr_pages,
1570 ARRAY_SIZE(pages)), pages);
1571 for (i = 0; i < ret; i++) {
1572 if (pages[i] != locked_page)
1573 unlock_page(pages[i]);
1582 static noinline int lock_delalloc_pages(struct inode *inode,
1583 struct page *locked_page,
1587 unsigned long index = delalloc_start >> PAGE_SHIFT;
1588 unsigned long start_index = index;
1589 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1590 unsigned long pages_locked = 0;
1591 struct page *pages[16];
1592 unsigned long nrpages;
1596 /* the caller is responsible for locking the start index */
1597 if (index == locked_page->index && index == end_index)
1600 /* skip the page at the start index */
1601 nrpages = end_index - index + 1;
1602 while (nrpages > 0) {
1603 ret = find_get_pages_contig(inode->i_mapping, index,
1604 min_t(unsigned long,
1605 nrpages, ARRAY_SIZE(pages)), pages);
1610 /* now we have an array of pages, lock them all */
1611 for (i = 0; i < ret; i++) {
1613 * the caller is taking responsibility for
1616 if (pages[i] != locked_page) {
1617 lock_page(pages[i]);
1618 if (!PageDirty(pages[i]) ||
1619 pages[i]->mapping != inode->i_mapping) {
1621 unlock_page(pages[i]);
1635 if (ret && pages_locked) {
1636 __unlock_for_delalloc(inode, locked_page,
1638 ((u64)(start_index + pages_locked - 1)) <<
1645 * find a contiguous range of bytes in the file marked as delalloc, not
1646 * more than 'max_bytes'. start and end are used to return the range,
1648 * 1 is returned if we find something, 0 if nothing was in the tree
1650 STATIC u64 find_lock_delalloc_range(struct inode *inode,
1651 struct extent_io_tree *tree,
1652 struct page *locked_page, u64 *start,
1653 u64 *end, u64 max_bytes)
1658 struct extent_state *cached_state = NULL;
1663 /* step one, find a bunch of delalloc bytes starting at start */
1664 delalloc_start = *start;
1666 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1667 max_bytes, &cached_state);
1668 if (!found || delalloc_end <= *start) {
1669 *start = delalloc_start;
1670 *end = delalloc_end;
1671 free_extent_state(cached_state);
1676 * start comes from the offset of locked_page. We have to lock
1677 * pages in order, so we can't process delalloc bytes before
1680 if (delalloc_start < *start)
1681 delalloc_start = *start;
1684 * make sure to limit the number of pages we try to lock down
1686 if (delalloc_end + 1 - delalloc_start > max_bytes)
1687 delalloc_end = delalloc_start + max_bytes - 1;
1689 /* step two, lock all the pages after the page that has start */
1690 ret = lock_delalloc_pages(inode, locked_page,
1691 delalloc_start, delalloc_end);
1692 if (ret == -EAGAIN) {
1693 /* some of the pages are gone, lets avoid looping by
1694 * shortening the size of the delalloc range we're searching
1696 free_extent_state(cached_state);
1697 cached_state = NULL;
1699 max_bytes = PAGE_SIZE;
1707 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1709 /* step three, lock the state bits for the whole range */
1710 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1712 /* then test to make sure it is all still delalloc */
1713 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1714 EXTENT_DELALLOC, 1, cached_state);
1716 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1717 &cached_state, GFP_NOFS);
1718 __unlock_for_delalloc(inode, locked_page,
1719 delalloc_start, delalloc_end);
1723 free_extent_state(cached_state);
1724 *start = delalloc_start;
1725 *end = delalloc_end;
1730 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1731 struct page *locked_page,
1732 unsigned clear_bits,
1733 unsigned long page_ops)
1735 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
1737 struct page *pages[16];
1738 unsigned long index = start >> PAGE_SHIFT;
1739 unsigned long end_index = end >> PAGE_SHIFT;
1740 unsigned long nr_pages = end_index - index + 1;
1743 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1747 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1748 mapping_set_error(inode->i_mapping, -EIO);
1750 while (nr_pages > 0) {
1751 ret = find_get_pages_contig(inode->i_mapping, index,
1752 min_t(unsigned long,
1753 nr_pages, ARRAY_SIZE(pages)), pages);
1754 for (i = 0; i < ret; i++) {
1756 if (page_ops & PAGE_SET_PRIVATE2)
1757 SetPagePrivate2(pages[i]);
1759 if (pages[i] == locked_page) {
1763 if (page_ops & PAGE_CLEAR_DIRTY)
1764 clear_page_dirty_for_io(pages[i]);
1765 if (page_ops & PAGE_SET_WRITEBACK)
1766 set_page_writeback(pages[i]);
1767 if (page_ops & PAGE_SET_ERROR)
1768 SetPageError(pages[i]);
1769 if (page_ops & PAGE_END_WRITEBACK)
1770 end_page_writeback(pages[i]);
1771 if (page_ops & PAGE_UNLOCK)
1772 unlock_page(pages[i]);
1782 * count the number of bytes in the tree that have a given bit(s)
1783 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1784 * cached. The total number found is returned.
1786 u64 count_range_bits(struct extent_io_tree *tree,
1787 u64 *start, u64 search_end, u64 max_bytes,
1788 unsigned bits, int contig)
1790 struct rb_node *node;
1791 struct extent_state *state;
1792 u64 cur_start = *start;
1793 u64 total_bytes = 0;
1797 if (WARN_ON(search_end <= cur_start))
1800 spin_lock(&tree->lock);
1801 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1802 total_bytes = tree->dirty_bytes;
1806 * this search will find all the extents that end after
1809 node = tree_search(tree, cur_start);
1814 state = rb_entry(node, struct extent_state, rb_node);
1815 if (state->start > search_end)
1817 if (contig && found && state->start > last + 1)
1819 if (state->end >= cur_start && (state->state & bits) == bits) {
1820 total_bytes += min(search_end, state->end) + 1 -
1821 max(cur_start, state->start);
1822 if (total_bytes >= max_bytes)
1825 *start = max(cur_start, state->start);
1829 } else if (contig && found) {
1832 node = rb_next(node);
1837 spin_unlock(&tree->lock);
1842 * set the private field for a given byte offset in the tree. If there isn't
1843 * an extent_state there already, this does nothing.
1845 static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start,
1846 struct io_failure_record *failrec)
1848 struct rb_node *node;
1849 struct extent_state *state;
1852 spin_lock(&tree->lock);
1854 * this search will find all the extents that end after
1857 node = tree_search(tree, start);
1862 state = rb_entry(node, struct extent_state, rb_node);
1863 if (state->start != start) {
1867 state->failrec = failrec;
1869 spin_unlock(&tree->lock);
1873 static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start,
1874 struct io_failure_record **failrec)
1876 struct rb_node *node;
1877 struct extent_state *state;
1880 spin_lock(&tree->lock);
1882 * this search will find all the extents that end after
1885 node = tree_search(tree, start);
1890 state = rb_entry(node, struct extent_state, rb_node);
1891 if (state->start != start) {
1895 *failrec = state->failrec;
1897 spin_unlock(&tree->lock);
1902 * searches a range in the state tree for a given mask.
1903 * If 'filled' == 1, this returns 1 only if every extent in the tree
1904 * has the bits set. Otherwise, 1 is returned if any bit in the
1905 * range is found set.
1907 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1908 unsigned bits, int filled, struct extent_state *cached)
1910 struct extent_state *state = NULL;
1911 struct rb_node *node;
1914 spin_lock(&tree->lock);
1915 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
1916 cached->end > start)
1917 node = &cached->rb_node;
1919 node = tree_search(tree, start);
1920 while (node && start <= end) {
1921 state = rb_entry(node, struct extent_state, rb_node);
1923 if (filled && state->start > start) {
1928 if (state->start > end)
1931 if (state->state & bits) {
1935 } else if (filled) {
1940 if (state->end == (u64)-1)
1943 start = state->end + 1;
1946 node = rb_next(node);
1953 spin_unlock(&tree->lock);
1958 * helper function to set a given page up to date if all the
1959 * extents in the tree for that page are up to date
1961 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1963 u64 start = page_offset(page);
1964 u64 end = start + PAGE_SIZE - 1;
1965 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1966 SetPageUptodate(page);
1969 int free_io_failure(struct inode *inode, struct io_failure_record *rec)
1973 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1975 set_state_failrec(failure_tree, rec->start, NULL);
1976 ret = clear_extent_bits(failure_tree, rec->start,
1977 rec->start + rec->len - 1,
1978 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1982 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1983 rec->start + rec->len - 1,
1984 EXTENT_DAMAGED, GFP_NOFS);
1993 * this bypasses the standard btrfs submit functions deliberately, as
1994 * the standard behavior is to write all copies in a raid setup. here we only
1995 * want to write the one bad copy. so we do the mapping for ourselves and issue
1996 * submit_bio directly.
1997 * to avoid any synchronization issues, wait for the data after writing, which
1998 * actually prevents the read that triggered the error from finishing.
1999 * currently, there can be no more than two copies of every data bit. thus,
2000 * exactly one rewrite is required.
2002 int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical,
2003 struct page *page, unsigned int pg_offset, int mirror_num)
2005 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2007 struct btrfs_device *dev;
2010 struct btrfs_bio *bbio = NULL;
2011 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
2014 ASSERT(!(fs_info->sb->s_flags & MS_RDONLY));
2015 BUG_ON(!mirror_num);
2017 /* we can't repair anything in raid56 yet */
2018 if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num))
2021 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2024 bio->bi_iter.bi_size = 0;
2025 map_length = length;
2027 ret = btrfs_map_block(fs_info, WRITE, logical,
2028 &map_length, &bbio, mirror_num);
2033 BUG_ON(mirror_num != bbio->mirror_num);
2034 sector = bbio->stripes[mirror_num-1].physical >> 9;
2035 bio->bi_iter.bi_sector = sector;
2036 dev = bbio->stripes[mirror_num-1].dev;
2037 btrfs_put_bbio(bbio);
2038 if (!dev || !dev->bdev || !dev->writeable) {
2042 bio->bi_bdev = dev->bdev;
2043 bio_add_page(bio, page, length, pg_offset);
2045 if (btrfsic_submit_bio_wait(WRITE_SYNC, bio)) {
2046 /* try to remap that extent elsewhere? */
2048 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2052 btrfs_info_rl_in_rcu(fs_info,
2053 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2054 btrfs_ino(inode), start,
2055 rcu_str_deref(dev->name), sector);
2060 int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
2063 u64 start = eb->start;
2064 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
2067 if (root->fs_info->sb->s_flags & MS_RDONLY)
2070 for (i = 0; i < num_pages; i++) {
2071 struct page *p = eb->pages[i];
2073 ret = repair_io_failure(root->fs_info->btree_inode, start,
2074 PAGE_SIZE, start, p,
2075 start - page_offset(p), mirror_num);
2085 * each time an IO finishes, we do a fast check in the IO failure tree
2086 * to see if we need to process or clean up an io_failure_record
2088 int clean_io_failure(struct inode *inode, u64 start, struct page *page,
2089 unsigned int pg_offset)
2092 struct io_failure_record *failrec;
2093 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2094 struct extent_state *state;
2099 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
2100 (u64)-1, 1, EXTENT_DIRTY, 0);
2104 ret = get_state_failrec(&BTRFS_I(inode)->io_failure_tree, start,
2109 BUG_ON(!failrec->this_mirror);
2111 if (failrec->in_validation) {
2112 /* there was no real error, just free the record */
2113 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2117 if (fs_info->sb->s_flags & MS_RDONLY)
2120 spin_lock(&BTRFS_I(inode)->io_tree.lock);
2121 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
2124 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
2126 if (state && state->start <= failrec->start &&
2127 state->end >= failrec->start + failrec->len - 1) {
2128 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2130 if (num_copies > 1) {
2131 repair_io_failure(inode, start, failrec->len,
2132 failrec->logical, page,
2133 pg_offset, failrec->failed_mirror);
2138 free_io_failure(inode, failrec);
2144 * Can be called when
2145 * - hold extent lock
2146 * - under ordered extent
2147 * - the inode is freeing
2149 void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end)
2151 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2152 struct io_failure_record *failrec;
2153 struct extent_state *state, *next;
2155 if (RB_EMPTY_ROOT(&failure_tree->state))
2158 spin_lock(&failure_tree->lock);
2159 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2161 if (state->start > end)
2164 ASSERT(state->end <= end);
2166 next = next_state(state);
2168 failrec = state->failrec;
2169 free_extent_state(state);
2174 spin_unlock(&failure_tree->lock);
2177 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2178 struct io_failure_record **failrec_ret)
2180 struct io_failure_record *failrec;
2181 struct extent_map *em;
2182 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2183 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2184 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2188 ret = get_state_failrec(failure_tree, start, &failrec);
2190 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2194 failrec->start = start;
2195 failrec->len = end - start + 1;
2196 failrec->this_mirror = 0;
2197 failrec->bio_flags = 0;
2198 failrec->in_validation = 0;
2200 read_lock(&em_tree->lock);
2201 em = lookup_extent_mapping(em_tree, start, failrec->len);
2203 read_unlock(&em_tree->lock);
2208 if (em->start > start || em->start + em->len <= start) {
2209 free_extent_map(em);
2212 read_unlock(&em_tree->lock);
2218 logical = start - em->start;
2219 logical = em->block_start + logical;
2220 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2221 logical = em->block_start;
2222 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2223 extent_set_compress_type(&failrec->bio_flags,
2227 pr_debug("Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu\n",
2228 logical, start, failrec->len);
2230 failrec->logical = logical;
2231 free_extent_map(em);
2233 /* set the bits in the private failure tree */
2234 ret = set_extent_bits(failure_tree, start, end,
2235 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
2237 ret = set_state_failrec(failure_tree, start, failrec);
2238 /* set the bits in the inode's tree */
2240 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
2247 pr_debug("Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d\n",
2248 failrec->logical, failrec->start, failrec->len,
2249 failrec->in_validation);
2251 * when data can be on disk more than twice, add to failrec here
2252 * (e.g. with a list for failed_mirror) to make
2253 * clean_io_failure() clean all those errors at once.
2257 *failrec_ret = failrec;
2262 int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
2263 struct io_failure_record *failrec, int failed_mirror)
2267 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
2268 failrec->logical, failrec->len);
2269 if (num_copies == 1) {
2271 * we only have a single copy of the data, so don't bother with
2272 * all the retry and error correction code that follows. no
2273 * matter what the error is, it is very likely to persist.
2275 pr_debug("Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
2276 num_copies, failrec->this_mirror, failed_mirror);
2281 * there are two premises:
2282 * a) deliver good data to the caller
2283 * b) correct the bad sectors on disk
2285 if (failed_bio->bi_vcnt > 1) {
2287 * to fulfill b), we need to know the exact failing sectors, as
2288 * we don't want to rewrite any more than the failed ones. thus,
2289 * we need separate read requests for the failed bio
2291 * if the following BUG_ON triggers, our validation request got
2292 * merged. we need separate requests for our algorithm to work.
2294 BUG_ON(failrec->in_validation);
2295 failrec->in_validation = 1;
2296 failrec->this_mirror = failed_mirror;
2299 * we're ready to fulfill a) and b) alongside. get a good copy
2300 * of the failed sector and if we succeed, we have setup
2301 * everything for repair_io_failure to do the rest for us.
2303 if (failrec->in_validation) {
2304 BUG_ON(failrec->this_mirror != failed_mirror);
2305 failrec->in_validation = 0;
2306 failrec->this_mirror = 0;
2308 failrec->failed_mirror = failed_mirror;
2309 failrec->this_mirror++;
2310 if (failrec->this_mirror == failed_mirror)
2311 failrec->this_mirror++;
2314 if (failrec->this_mirror > num_copies) {
2315 pr_debug("Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
2316 num_copies, failrec->this_mirror, failed_mirror);
2324 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
2325 struct io_failure_record *failrec,
2326 struct page *page, int pg_offset, int icsum,
2327 bio_end_io_t *endio_func, void *data)
2330 struct btrfs_io_bio *btrfs_failed_bio;
2331 struct btrfs_io_bio *btrfs_bio;
2333 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2337 bio->bi_end_io = endio_func;
2338 bio->bi_iter.bi_sector = failrec->logical >> 9;
2339 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
2340 bio->bi_iter.bi_size = 0;
2341 bio->bi_private = data;
2343 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2344 if (btrfs_failed_bio->csum) {
2345 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2346 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2348 btrfs_bio = btrfs_io_bio(bio);
2349 btrfs_bio->csum = btrfs_bio->csum_inline;
2351 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
2355 bio_add_page(bio, page, failrec->len, pg_offset);
2361 * this is a generic handler for readpage errors (default
2362 * readpage_io_failed_hook). if other copies exist, read those and write back
2363 * good data to the failed position. does not investigate in remapping the
2364 * failed extent elsewhere, hoping the device will be smart enough to do this as
2368 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2369 struct page *page, u64 start, u64 end,
2372 struct io_failure_record *failrec;
2373 struct inode *inode = page->mapping->host;
2374 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2379 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
2381 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2385 ret = btrfs_check_repairable(inode, failed_bio, failrec, failed_mirror);
2387 free_io_failure(inode, failrec);
2391 if (failed_bio->bi_vcnt > 1)
2392 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
2394 read_mode = READ_SYNC;
2396 phy_offset >>= inode->i_sb->s_blocksize_bits;
2397 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
2398 start - page_offset(page),
2399 (int)phy_offset, failed_bio->bi_end_io,
2402 free_io_failure(inode, failrec);
2406 pr_debug("Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d\n",
2407 read_mode, failrec->this_mirror, failrec->in_validation);
2409 ret = tree->ops->submit_bio_hook(inode, read_mode, bio,
2410 failrec->this_mirror,
2411 failrec->bio_flags, 0);
2413 free_io_failure(inode, failrec);
2420 /* lots and lots of room for performance fixes in the end_bio funcs */
2422 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2424 int uptodate = (err == 0);
2425 struct extent_io_tree *tree;
2428 tree = &BTRFS_I(page->mapping->host)->io_tree;
2430 if (tree->ops && tree->ops->writepage_end_io_hook) {
2431 ret = tree->ops->writepage_end_io_hook(page, start,
2432 end, NULL, uptodate);
2438 ClearPageUptodate(page);
2440 ret = ret < 0 ? ret : -EIO;
2441 mapping_set_error(page->mapping, ret);
2446 * after a writepage IO is done, we need to:
2447 * clear the uptodate bits on error
2448 * clear the writeback bits in the extent tree for this IO
2449 * end_page_writeback if the page has no more pending IO
2451 * Scheduling is not allowed, so the extent state tree is expected
2452 * to have one and only one object corresponding to this IO.
2454 static void end_bio_extent_writepage(struct bio *bio)
2456 struct bio_vec *bvec;
2461 bio_for_each_segment_all(bvec, bio, i) {
2462 struct page *page = bvec->bv_page;
2464 /* We always issue full-page reads, but if some block
2465 * in a page fails to read, blk_update_request() will
2466 * advance bv_offset and adjust bv_len to compensate.
2467 * Print a warning for nonzero offsets, and an error
2468 * if they don't add up to a full page. */
2469 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2470 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2471 btrfs_err(BTRFS_I(page->mapping->host)->root->fs_info,
2472 "partial page write in btrfs with offset %u and length %u",
2473 bvec->bv_offset, bvec->bv_len);
2475 btrfs_info(BTRFS_I(page->mapping->host)->root->fs_info,
2476 "incomplete page write in btrfs with offset %u and "
2478 bvec->bv_offset, bvec->bv_len);
2481 start = page_offset(page);
2482 end = start + bvec->bv_offset + bvec->bv_len - 1;
2484 end_extent_writepage(page, bio->bi_error, start, end);
2485 end_page_writeback(page);
2492 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2495 struct extent_state *cached = NULL;
2496 u64 end = start + len - 1;
2498 if (uptodate && tree->track_uptodate)
2499 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2500 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2504 * after a readpage IO is done, we need to:
2505 * clear the uptodate bits on error
2506 * set the uptodate bits if things worked
2507 * set the page up to date if all extents in the tree are uptodate
2508 * clear the lock bit in the extent tree
2509 * unlock the page if there are no other extents locked for it
2511 * Scheduling is not allowed, so the extent state tree is expected
2512 * to have one and only one object corresponding to this IO.
2514 static void end_bio_extent_readpage(struct bio *bio)
2516 struct bio_vec *bvec;
2517 int uptodate = !bio->bi_error;
2518 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2519 struct extent_io_tree *tree;
2524 u64 extent_start = 0;
2530 bio_for_each_segment_all(bvec, bio, i) {
2531 struct page *page = bvec->bv_page;
2532 struct inode *inode = page->mapping->host;
2534 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2535 "mirror=%u\n", (u64)bio->bi_iter.bi_sector,
2536 bio->bi_error, io_bio->mirror_num);
2537 tree = &BTRFS_I(inode)->io_tree;
2539 /* We always issue full-page reads, but if some block
2540 * in a page fails to read, blk_update_request() will
2541 * advance bv_offset and adjust bv_len to compensate.
2542 * Print a warning for nonzero offsets, and an error
2543 * if they don't add up to a full page. */
2544 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2545 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2546 btrfs_err(BTRFS_I(page->mapping->host)->root->fs_info,
2547 "partial page read in btrfs with offset %u and length %u",
2548 bvec->bv_offset, bvec->bv_len);
2550 btrfs_info(BTRFS_I(page->mapping->host)->root->fs_info,
2551 "incomplete page read in btrfs with offset %u and "
2553 bvec->bv_offset, bvec->bv_len);
2556 start = page_offset(page);
2557 end = start + bvec->bv_offset + bvec->bv_len - 1;
2560 mirror = io_bio->mirror_num;
2561 if (likely(uptodate && tree->ops &&
2562 tree->ops->readpage_end_io_hook)) {
2563 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2569 clean_io_failure(inode, start, page, 0);
2572 if (likely(uptodate))
2575 if (tree->ops && tree->ops->readpage_io_failed_hook) {
2576 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2577 if (!ret && !bio->bi_error)
2581 * The generic bio_readpage_error handles errors the
2582 * following way: If possible, new read requests are
2583 * created and submitted and will end up in
2584 * end_bio_extent_readpage as well (if we're lucky, not
2585 * in the !uptodate case). In that case it returns 0 and
2586 * we just go on with the next page in our bio. If it
2587 * can't handle the error it will return -EIO and we
2588 * remain responsible for that page.
2590 ret = bio_readpage_error(bio, offset, page, start, end,
2593 uptodate = !bio->bi_error;
2599 if (likely(uptodate)) {
2600 loff_t i_size = i_size_read(inode);
2601 pgoff_t end_index = i_size >> PAGE_SHIFT;
2604 /* Zero out the end if this page straddles i_size */
2605 off = i_size & (PAGE_SIZE-1);
2606 if (page->index == end_index && off)
2607 zero_user_segment(page, off, PAGE_SIZE);
2608 SetPageUptodate(page);
2610 ClearPageUptodate(page);
2616 if (unlikely(!uptodate)) {
2618 endio_readpage_release_extent(tree,
2624 endio_readpage_release_extent(tree, start,
2625 end - start + 1, 0);
2626 } else if (!extent_len) {
2627 extent_start = start;
2628 extent_len = end + 1 - start;
2629 } else if (extent_start + extent_len == start) {
2630 extent_len += end + 1 - start;
2632 endio_readpage_release_extent(tree, extent_start,
2633 extent_len, uptodate);
2634 extent_start = start;
2635 extent_len = end + 1 - start;
2640 endio_readpage_release_extent(tree, extent_start, extent_len,
2643 io_bio->end_io(io_bio, bio->bi_error);
2648 * this allocates from the btrfs_bioset. We're returning a bio right now
2649 * but you can call btrfs_io_bio for the appropriate container_of magic
2652 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2655 struct btrfs_io_bio *btrfs_bio;
2658 bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset);
2660 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2661 while (!bio && (nr_vecs /= 2)) {
2662 bio = bio_alloc_bioset(gfp_flags,
2663 nr_vecs, btrfs_bioset);
2668 bio->bi_bdev = bdev;
2669 bio->bi_iter.bi_sector = first_sector;
2670 btrfs_bio = btrfs_io_bio(bio);
2671 btrfs_bio->csum = NULL;
2672 btrfs_bio->csum_allocated = NULL;
2673 btrfs_bio->end_io = NULL;
2678 struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
2680 struct btrfs_io_bio *btrfs_bio;
2683 new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset);
2685 btrfs_bio = btrfs_io_bio(new);
2686 btrfs_bio->csum = NULL;
2687 btrfs_bio->csum_allocated = NULL;
2688 btrfs_bio->end_io = NULL;
2690 #ifdef CONFIG_BLK_CGROUP
2691 /* FIXME, put this into bio_clone_bioset */
2693 bio_associate_blkcg(new, bio->bi_css);
2699 /* this also allocates from the btrfs_bioset */
2700 struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
2702 struct btrfs_io_bio *btrfs_bio;
2705 bio = bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
2707 btrfs_bio = btrfs_io_bio(bio);
2708 btrfs_bio->csum = NULL;
2709 btrfs_bio->csum_allocated = NULL;
2710 btrfs_bio->end_io = NULL;
2716 static int __must_check submit_one_bio(int rw, struct bio *bio,
2717 int mirror_num, unsigned long bio_flags)
2720 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2721 struct page *page = bvec->bv_page;
2722 struct extent_io_tree *tree = bio->bi_private;
2725 start = page_offset(page) + bvec->bv_offset;
2727 bio->bi_private = NULL;
2731 if (tree->ops && tree->ops->submit_bio_hook)
2732 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
2733 mirror_num, bio_flags, start);
2735 btrfsic_submit_bio(rw, bio);
2741 static int merge_bio(int rw, struct extent_io_tree *tree, struct page *page,
2742 unsigned long offset, size_t size, struct bio *bio,
2743 unsigned long bio_flags)
2746 if (tree->ops && tree->ops->merge_bio_hook)
2747 ret = tree->ops->merge_bio_hook(rw, page, offset, size, bio,
2754 static int submit_extent_page(int rw, struct extent_io_tree *tree,
2755 struct writeback_control *wbc,
2756 struct page *page, sector_t sector,
2757 size_t size, unsigned long offset,
2758 struct block_device *bdev,
2759 struct bio **bio_ret,
2760 unsigned long max_pages,
2761 bio_end_io_t end_io_func,
2763 unsigned long prev_bio_flags,
2764 unsigned long bio_flags,
2765 bool force_bio_submit)
2770 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2771 size_t page_size = min_t(size_t, size, PAGE_SIZE);
2773 if (bio_ret && *bio_ret) {
2776 contig = bio->bi_iter.bi_sector == sector;
2778 contig = bio_end_sector(bio) == sector;
2780 if (prev_bio_flags != bio_flags || !contig ||
2782 merge_bio(rw, tree, page, offset, page_size, bio, bio_flags) ||
2783 bio_add_page(bio, page, page_size, offset) < page_size) {
2784 ret = submit_one_bio(rw, bio, mirror_num,
2793 wbc_account_io(wbc, page, page_size);
2798 bio = btrfs_bio_alloc(bdev, sector, BIO_MAX_PAGES,
2799 GFP_NOFS | __GFP_HIGH);
2803 bio_add_page(bio, page, page_size, offset);
2804 bio->bi_end_io = end_io_func;
2805 bio->bi_private = tree;
2807 wbc_init_bio(wbc, bio);
2808 wbc_account_io(wbc, page, page_size);
2814 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
2819 static void attach_extent_buffer_page(struct extent_buffer *eb,
2822 if (!PagePrivate(page)) {
2823 SetPagePrivate(page);
2825 set_page_private(page, (unsigned long)eb);
2827 WARN_ON(page->private != (unsigned long)eb);
2831 void set_page_extent_mapped(struct page *page)
2833 if (!PagePrivate(page)) {
2834 SetPagePrivate(page);
2836 set_page_private(page, EXTENT_PAGE_PRIVATE);
2840 static struct extent_map *
2841 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
2842 u64 start, u64 len, get_extent_t *get_extent,
2843 struct extent_map **em_cached)
2845 struct extent_map *em;
2847 if (em_cached && *em_cached) {
2849 if (extent_map_in_tree(em) && start >= em->start &&
2850 start < extent_map_end(em)) {
2851 atomic_inc(&em->refs);
2855 free_extent_map(em);
2859 em = get_extent(inode, page, pg_offset, start, len, 0);
2860 if (em_cached && !IS_ERR_OR_NULL(em)) {
2862 atomic_inc(&em->refs);
2868 * basic readpage implementation. Locked extent state structs are inserted
2869 * into the tree that are removed when the IO is done (by the end_io
2871 * XXX JDM: This needs looking at to ensure proper page locking
2873 static int __do_readpage(struct extent_io_tree *tree,
2875 get_extent_t *get_extent,
2876 struct extent_map **em_cached,
2877 struct bio **bio, int mirror_num,
2878 unsigned long *bio_flags, int rw,
2881 struct inode *inode = page->mapping->host;
2882 u64 start = page_offset(page);
2883 u64 page_end = start + PAGE_SIZE - 1;
2887 u64 last_byte = i_size_read(inode);
2891 struct extent_map *em;
2892 struct block_device *bdev;
2895 size_t pg_offset = 0;
2897 size_t disk_io_size;
2898 size_t blocksize = inode->i_sb->s_blocksize;
2899 unsigned long this_bio_flag = 0;
2901 set_page_extent_mapped(page);
2904 if (!PageUptodate(page)) {
2905 if (cleancache_get_page(page) == 0) {
2906 BUG_ON(blocksize != PAGE_SIZE);
2907 unlock_extent(tree, start, end);
2912 if (page->index == last_byte >> PAGE_SHIFT) {
2914 size_t zero_offset = last_byte & (PAGE_SIZE - 1);
2917 iosize = PAGE_SIZE - zero_offset;
2918 userpage = kmap_atomic(page);
2919 memset(userpage + zero_offset, 0, iosize);
2920 flush_dcache_page(page);
2921 kunmap_atomic(userpage);
2924 while (cur <= end) {
2925 unsigned long pnr = (last_byte >> PAGE_SHIFT) + 1;
2926 bool force_bio_submit = false;
2928 if (cur >= last_byte) {
2930 struct extent_state *cached = NULL;
2932 iosize = PAGE_SIZE - pg_offset;
2933 userpage = kmap_atomic(page);
2934 memset(userpage + pg_offset, 0, iosize);
2935 flush_dcache_page(page);
2936 kunmap_atomic(userpage);
2937 set_extent_uptodate(tree, cur, cur + iosize - 1,
2939 unlock_extent_cached(tree, cur,
2944 em = __get_extent_map(inode, page, pg_offset, cur,
2945 end - cur + 1, get_extent, em_cached);
2946 if (IS_ERR_OR_NULL(em)) {
2948 unlock_extent(tree, cur, end);
2951 extent_offset = cur - em->start;
2952 BUG_ON(extent_map_end(em) <= cur);
2955 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2956 this_bio_flag |= EXTENT_BIO_COMPRESSED;
2957 extent_set_compress_type(&this_bio_flag,
2961 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2962 cur_end = min(extent_map_end(em) - 1, end);
2963 iosize = ALIGN(iosize, blocksize);
2964 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2965 disk_io_size = em->block_len;
2966 sector = em->block_start >> 9;
2968 sector = (em->block_start + extent_offset) >> 9;
2969 disk_io_size = iosize;
2972 block_start = em->block_start;
2973 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2974 block_start = EXTENT_MAP_HOLE;
2977 * If we have a file range that points to a compressed extent
2978 * and it's followed by a consecutive file range that points to
2979 * to the same compressed extent (possibly with a different
2980 * offset and/or length, so it either points to the whole extent
2981 * or only part of it), we must make sure we do not submit a
2982 * single bio to populate the pages for the 2 ranges because
2983 * this makes the compressed extent read zero out the pages
2984 * belonging to the 2nd range. Imagine the following scenario:
2987 * [0 - 8K] [8K - 24K]
2990 * points to extent X, points to extent X,
2991 * offset 4K, length of 8K offset 0, length 16K
2993 * [extent X, compressed length = 4K uncompressed length = 16K]
2995 * If the bio to read the compressed extent covers both ranges,
2996 * it will decompress extent X into the pages belonging to the
2997 * first range and then it will stop, zeroing out the remaining
2998 * pages that belong to the other range that points to extent X.
2999 * So here we make sure we submit 2 bios, one for the first
3000 * range and another one for the third range. Both will target
3001 * the same physical extent from disk, but we can't currently
3002 * make the compressed bio endio callback populate the pages
3003 * for both ranges because each compressed bio is tightly
3004 * coupled with a single extent map, and each range can have
3005 * an extent map with a different offset value relative to the
3006 * uncompressed data of our extent and different lengths. This
3007 * is a corner case so we prioritize correctness over
3008 * non-optimal behavior (submitting 2 bios for the same extent).
3010 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3011 prev_em_start && *prev_em_start != (u64)-1 &&
3012 *prev_em_start != em->orig_start)
3013 force_bio_submit = true;
3016 *prev_em_start = em->orig_start;
3018 free_extent_map(em);
3021 /* we've found a hole, just zero and go on */
3022 if (block_start == EXTENT_MAP_HOLE) {
3024 struct extent_state *cached = NULL;
3026 userpage = kmap_atomic(page);
3027 memset(userpage + pg_offset, 0, iosize);
3028 flush_dcache_page(page);
3029 kunmap_atomic(userpage);
3031 set_extent_uptodate(tree, cur, cur + iosize - 1,
3033 unlock_extent_cached(tree, cur,
3037 pg_offset += iosize;
3040 /* the get_extent function already copied into the page */
3041 if (test_range_bit(tree, cur, cur_end,
3042 EXTENT_UPTODATE, 1, NULL)) {
3043 check_page_uptodate(tree, page);
3044 unlock_extent(tree, cur, cur + iosize - 1);
3046 pg_offset += iosize;
3049 /* we have an inline extent but it didn't get marked up
3050 * to date. Error out
3052 if (block_start == EXTENT_MAP_INLINE) {
3054 unlock_extent(tree, cur, cur + iosize - 1);
3056 pg_offset += iosize;
3061 ret = submit_extent_page(rw, tree, NULL, page,
3062 sector, disk_io_size, pg_offset,
3064 end_bio_extent_readpage, mirror_num,
3070 *bio_flags = this_bio_flag;
3073 unlock_extent(tree, cur, cur + iosize - 1);
3076 pg_offset += iosize;
3080 if (!PageError(page))
3081 SetPageUptodate(page);
3087 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
3088 struct page *pages[], int nr_pages,
3090 get_extent_t *get_extent,
3091 struct extent_map **em_cached,
3092 struct bio **bio, int mirror_num,
3093 unsigned long *bio_flags, int rw,
3096 struct inode *inode;
3097 struct btrfs_ordered_extent *ordered;
3100 inode = pages[0]->mapping->host;
3102 lock_extent(tree, start, end);
3103 ordered = btrfs_lookup_ordered_range(inode, start,
3107 unlock_extent(tree, start, end);
3108 btrfs_start_ordered_extent(inode, ordered, 1);
3109 btrfs_put_ordered_extent(ordered);
3112 for (index = 0; index < nr_pages; index++) {
3113 __do_readpage(tree, pages[index], get_extent, em_cached, bio,
3114 mirror_num, bio_flags, rw, prev_em_start);
3115 put_page(pages[index]);
3119 static void __extent_readpages(struct extent_io_tree *tree,
3120 struct page *pages[],
3121 int nr_pages, get_extent_t *get_extent,
3122 struct extent_map **em_cached,
3123 struct bio **bio, int mirror_num,
3124 unsigned long *bio_flags, int rw,
3131 int first_index = 0;
3133 for (index = 0; index < nr_pages; index++) {
3134 page_start = page_offset(pages[index]);
3137 end = start + PAGE_SIZE - 1;
3138 first_index = index;
3139 } else if (end + 1 == page_start) {
3142 __do_contiguous_readpages(tree, &pages[first_index],
3143 index - first_index, start,
3144 end, get_extent, em_cached,
3145 bio, mirror_num, bio_flags,
3148 end = start + PAGE_SIZE - 1;
3149 first_index = index;
3154 __do_contiguous_readpages(tree, &pages[first_index],
3155 index - first_index, start,
3156 end, get_extent, em_cached, bio,
3157 mirror_num, bio_flags, rw,
3161 static int __extent_read_full_page(struct extent_io_tree *tree,
3163 get_extent_t *get_extent,
3164 struct bio **bio, int mirror_num,
3165 unsigned long *bio_flags, int rw)
3167 struct inode *inode = page->mapping->host;
3168 struct btrfs_ordered_extent *ordered;
3169 u64 start = page_offset(page);
3170 u64 end = start + PAGE_SIZE - 1;
3174 lock_extent(tree, start, end);
3175 ordered = btrfs_lookup_ordered_range(inode, start,
3179 unlock_extent(tree, start, end);
3180 btrfs_start_ordered_extent(inode, ordered, 1);
3181 btrfs_put_ordered_extent(ordered);
3184 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3185 bio_flags, rw, NULL);
3189 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3190 get_extent_t *get_extent, int mirror_num)
3192 struct bio *bio = NULL;
3193 unsigned long bio_flags = 0;
3196 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3199 ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
3203 static noinline void update_nr_written(struct page *page,
3204 struct writeback_control *wbc,
3205 unsigned long nr_written)
3207 wbc->nr_to_write -= nr_written;
3208 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
3209 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
3210 page->mapping->writeback_index = page->index + nr_written;
3214 * helper for __extent_writepage, doing all of the delayed allocation setup.
3216 * This returns 1 if our fill_delalloc function did all the work required
3217 * to write the page (copy into inline extent). In this case the IO has
3218 * been started and the page is already unlocked.
3220 * This returns 0 if all went well (page still locked)
3221 * This returns < 0 if there were errors (page still locked)
3223 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3224 struct page *page, struct writeback_control *wbc,
3225 struct extent_page_data *epd,
3227 unsigned long *nr_written)
3229 struct extent_io_tree *tree = epd->tree;
3230 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3232 u64 delalloc_to_write = 0;
3233 u64 delalloc_end = 0;
3235 int page_started = 0;
3237 if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
3240 while (delalloc_end < page_end) {
3241 nr_delalloc = find_lock_delalloc_range(inode, tree,
3245 BTRFS_MAX_EXTENT_SIZE);
3246 if (nr_delalloc == 0) {
3247 delalloc_start = delalloc_end + 1;
3250 ret = tree->ops->fill_delalloc(inode, page,
3255 /* File system has been set read-only */
3258 /* fill_delalloc should be return < 0 for error
3259 * but just in case, we use > 0 here meaning the
3260 * IO is started, so we don't want to return > 0
3261 * unless things are going well.
3263 ret = ret < 0 ? ret : -EIO;
3267 * delalloc_end is already one less than the total length, so
3268 * we don't subtract one from PAGE_SIZE
3270 delalloc_to_write += (delalloc_end - delalloc_start +
3271 PAGE_SIZE) >> PAGE_SHIFT;
3272 delalloc_start = delalloc_end + 1;
3274 if (wbc->nr_to_write < delalloc_to_write) {
3277 if (delalloc_to_write < thresh * 2)
3278 thresh = delalloc_to_write;
3279 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3283 /* did the fill delalloc function already unlock and start
3288 * we've unlocked the page, so we can't update
3289 * the mapping's writeback index, just update
3292 wbc->nr_to_write -= *nr_written;
3303 * helper for __extent_writepage. This calls the writepage start hooks,
3304 * and does the loop to map the page into extents and bios.
3306 * We return 1 if the IO is started and the page is unlocked,
3307 * 0 if all went well (page still locked)
3308 * < 0 if there were errors (page still locked)
3310 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3312 struct writeback_control *wbc,
3313 struct extent_page_data *epd,
3315 unsigned long nr_written,
3316 int write_flags, int *nr_ret)
3318 struct extent_io_tree *tree = epd->tree;
3319 u64 start = page_offset(page);
3320 u64 page_end = start + PAGE_SIZE - 1;
3327 struct extent_state *cached_state = NULL;
3328 struct extent_map *em;
3329 struct block_device *bdev;
3330 size_t pg_offset = 0;
3336 if (tree->ops && tree->ops->writepage_start_hook) {
3337 ret = tree->ops->writepage_start_hook(page, start,
3340 /* Fixup worker will requeue */
3342 wbc->pages_skipped++;
3344 redirty_page_for_writepage(wbc, page);
3346 update_nr_written(page, wbc, nr_written);
3354 * we don't want to touch the inode after unlocking the page,
3355 * so we update the mapping writeback index now
3357 update_nr_written(page, wbc, nr_written + 1);
3360 if (i_size <= start) {
3361 if (tree->ops && tree->ops->writepage_end_io_hook)
3362 tree->ops->writepage_end_io_hook(page, start,
3367 blocksize = inode->i_sb->s_blocksize;
3369 while (cur <= end) {
3371 if (cur >= i_size) {
3372 if (tree->ops && tree->ops->writepage_end_io_hook)
3373 tree->ops->writepage_end_io_hook(page, cur,
3377 em = epd->get_extent(inode, page, pg_offset, cur,
3379 if (IS_ERR_OR_NULL(em)) {
3381 ret = PTR_ERR_OR_ZERO(em);
3385 extent_offset = cur - em->start;
3386 em_end = extent_map_end(em);
3387 BUG_ON(em_end <= cur);
3389 iosize = min(em_end - cur, end - cur + 1);
3390 iosize = ALIGN(iosize, blocksize);
3391 sector = (em->block_start + extent_offset) >> 9;
3393 block_start = em->block_start;
3394 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3395 free_extent_map(em);
3399 * compressed and inline extents are written through other
3402 if (compressed || block_start == EXTENT_MAP_HOLE ||
3403 block_start == EXTENT_MAP_INLINE) {
3405 * end_io notification does not happen here for
3406 * compressed extents
3408 if (!compressed && tree->ops &&
3409 tree->ops->writepage_end_io_hook)
3410 tree->ops->writepage_end_io_hook(page, cur,
3413 else if (compressed) {
3414 /* we don't want to end_page_writeback on
3415 * a compressed extent. this happens
3422 pg_offset += iosize;
3426 if (tree->ops && tree->ops->writepage_io_hook) {
3427 ret = tree->ops->writepage_io_hook(page, cur,
3435 unsigned long max_nr = (i_size >> PAGE_SHIFT) + 1;
3437 set_range_writeback(tree, cur, cur + iosize - 1);
3438 if (!PageWriteback(page)) {
3439 btrfs_err(BTRFS_I(inode)->root->fs_info,
3440 "page %lu not writeback, cur %llu end %llu",
3441 page->index, cur, end);
3444 ret = submit_extent_page(write_flags, tree, wbc, page,
3445 sector, iosize, pg_offset,
3446 bdev, &epd->bio, max_nr,
3447 end_bio_extent_writepage,
3453 pg_offset += iosize;
3461 /* drop our reference on any cached states */
3462 free_extent_state(cached_state);
3467 * the writepage semantics are similar to regular writepage. extent
3468 * records are inserted to lock ranges in the tree, and as dirty areas
3469 * are found, they are marked writeback. Then the lock bits are removed
3470 * and the end_io handler clears the writeback ranges
3472 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3475 struct inode *inode = page->mapping->host;
3476 struct extent_page_data *epd = data;
3477 u64 start = page_offset(page);
3478 u64 page_end = start + PAGE_SIZE - 1;
3481 size_t pg_offset = 0;
3482 loff_t i_size = i_size_read(inode);
3483 unsigned long end_index = i_size >> PAGE_SHIFT;
3485 unsigned long nr_written = 0;
3487 if (wbc->sync_mode == WB_SYNC_ALL)
3488 write_flags = WRITE_SYNC;
3490 write_flags = WRITE;
3492 trace___extent_writepage(page, inode, wbc);
3494 WARN_ON(!PageLocked(page));
3496 ClearPageError(page);
3498 pg_offset = i_size & (PAGE_SIZE - 1);
3499 if (page->index > end_index ||
3500 (page->index == end_index && !pg_offset)) {
3501 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3506 if (page->index == end_index) {
3509 userpage = kmap_atomic(page);
3510 memset(userpage + pg_offset, 0,
3511 PAGE_SIZE - pg_offset);
3512 kunmap_atomic(userpage);
3513 flush_dcache_page(page);
3518 set_page_extent_mapped(page);
3520 ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
3526 ret = __extent_writepage_io(inode, page, wbc, epd,
3527 i_size, nr_written, write_flags, &nr);
3533 /* make sure the mapping tag for page dirty gets cleared */
3534 set_page_writeback(page);
3535 end_page_writeback(page);
3537 if (PageError(page)) {
3538 ret = ret < 0 ? ret : -EIO;
3539 end_extent_writepage(page, ret, start, page_end);
3548 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3550 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3551 TASK_UNINTERRUPTIBLE);
3554 static noinline_for_stack int
3555 lock_extent_buffer_for_io(struct extent_buffer *eb,
3556 struct btrfs_fs_info *fs_info,
3557 struct extent_page_data *epd)
3559 unsigned long i, num_pages;
3563 if (!btrfs_try_tree_write_lock(eb)) {
3565 flush_write_bio(epd);
3566 btrfs_tree_lock(eb);
3569 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3570 btrfs_tree_unlock(eb);
3574 flush_write_bio(epd);
3578 wait_on_extent_buffer_writeback(eb);
3579 btrfs_tree_lock(eb);
3580 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3582 btrfs_tree_unlock(eb);
3587 * We need to do this to prevent races in people who check if the eb is
3588 * under IO since we can end up having no IO bits set for a short period
3591 spin_lock(&eb->refs_lock);
3592 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3593 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3594 spin_unlock(&eb->refs_lock);
3595 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3596 __percpu_counter_add(&fs_info->dirty_metadata_bytes,
3598 fs_info->dirty_metadata_batch);
3601 spin_unlock(&eb->refs_lock);
3604 btrfs_tree_unlock(eb);
3609 num_pages = num_extent_pages(eb->start, eb->len);
3610 for (i = 0; i < num_pages; i++) {
3611 struct page *p = eb->pages[i];
3613 if (!trylock_page(p)) {
3615 flush_write_bio(epd);
3625 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3627 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3628 smp_mb__after_atomic();
3629 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3632 static void set_btree_ioerr(struct page *page)
3634 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3635 struct btrfs_inode *btree_ino = BTRFS_I(eb->fs_info->btree_inode);
3638 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3642 * If writeback for a btree extent that doesn't belong to a log tree
3643 * failed, increment the counter transaction->eb_write_errors.
3644 * We do this because while the transaction is running and before it's
3645 * committing (when we call filemap_fdata[write|wait]_range against
3646 * the btree inode), we might have
3647 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3648 * returns an error or an error happens during writeback, when we're
3649 * committing the transaction we wouldn't know about it, since the pages
3650 * can be no longer dirty nor marked anymore for writeback (if a
3651 * subsequent modification to the extent buffer didn't happen before the
3652 * transaction commit), which makes filemap_fdata[write|wait]_range not
3653 * able to find the pages tagged with SetPageError at transaction
3654 * commit time. So if this happens we must abort the transaction,
3655 * otherwise we commit a super block with btree roots that point to
3656 * btree nodes/leafs whose content on disk is invalid - either garbage
3657 * or the content of some node/leaf from a past generation that got
3658 * cowed or deleted and is no longer valid.
3660 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3661 * not be enough - we need to distinguish between log tree extents vs
3662 * non-log tree extents, and the next filemap_fdatawait_range() call
3663 * will catch and clear such errors in the mapping - and that call might
3664 * be from a log sync and not from a transaction commit. Also, checking
3665 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3666 * not done and would not be reliable - the eb might have been released
3667 * from memory and reading it back again means that flag would not be
3668 * set (since it's a runtime flag, not persisted on disk).
3670 * Using the flags below in the btree inode also makes us achieve the
3671 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3672 * writeback for all dirty pages and before filemap_fdatawait_range()
3673 * is called, the writeback for all dirty pages had already finished
3674 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3675 * filemap_fdatawait_range() would return success, as it could not know
3676 * that writeback errors happened (the pages were no longer tagged for
3679 switch (eb->log_index) {
3681 set_bit(BTRFS_INODE_BTREE_ERR, &btree_ino->runtime_flags);
3684 set_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags);
3687 set_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags);
3690 BUG(); /* unexpected, logic error */
3694 static void end_bio_extent_buffer_writepage(struct bio *bio)
3696 struct bio_vec *bvec;
3697 struct extent_buffer *eb;
3700 bio_for_each_segment_all(bvec, bio, i) {
3701 struct page *page = bvec->bv_page;
3703 eb = (struct extent_buffer *)page->private;
3705 done = atomic_dec_and_test(&eb->io_pages);
3707 if (bio->bi_error ||
3708 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3709 ClearPageUptodate(page);
3710 set_btree_ioerr(page);
3713 end_page_writeback(page);
3718 end_extent_buffer_writeback(eb);
3724 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3725 struct btrfs_fs_info *fs_info,
3726 struct writeback_control *wbc,
3727 struct extent_page_data *epd)
3729 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3730 struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
3731 u64 offset = eb->start;
3732 unsigned long i, num_pages;
3733 unsigned long bio_flags = 0;
3734 int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META;
3737 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3738 num_pages = num_extent_pages(eb->start, eb->len);
3739 atomic_set(&eb->io_pages, num_pages);
3740 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3741 bio_flags = EXTENT_BIO_TREE_LOG;
3743 for (i = 0; i < num_pages; i++) {
3744 struct page *p = eb->pages[i];
3746 clear_page_dirty_for_io(p);
3747 set_page_writeback(p);
3748 ret = submit_extent_page(rw, tree, wbc, p, offset >> 9,
3749 PAGE_SIZE, 0, bdev, &epd->bio,
3750 -1, end_bio_extent_buffer_writepage,
3751 0, epd->bio_flags, bio_flags, false);
3752 epd->bio_flags = bio_flags;
3755 end_page_writeback(p);
3756 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3757 end_extent_buffer_writeback(eb);
3761 offset += PAGE_SIZE;
3762 update_nr_written(p, wbc, 1);
3766 if (unlikely(ret)) {
3767 for (; i < num_pages; i++) {
3768 struct page *p = eb->pages[i];
3769 clear_page_dirty_for_io(p);
3777 int btree_write_cache_pages(struct address_space *mapping,
3778 struct writeback_control *wbc)
3780 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3781 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3782 struct extent_buffer *eb, *prev_eb = NULL;
3783 struct extent_page_data epd = {
3787 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3792 int nr_to_write_done = 0;
3793 struct pagevec pvec;
3796 pgoff_t end; /* Inclusive */
3800 pagevec_init(&pvec, 0);
3801 if (wbc->range_cyclic) {
3802 index = mapping->writeback_index; /* Start from prev offset */
3805 index = wbc->range_start >> PAGE_SHIFT;
3806 end = wbc->range_end >> PAGE_SHIFT;
3809 if (wbc->sync_mode == WB_SYNC_ALL)
3810 tag = PAGECACHE_TAG_TOWRITE;
3812 tag = PAGECACHE_TAG_DIRTY;
3814 if (wbc->sync_mode == WB_SYNC_ALL)
3815 tag_pages_for_writeback(mapping, index, end);
3816 while (!done && !nr_to_write_done && (index <= end) &&
3817 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3818 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3822 for (i = 0; i < nr_pages; i++) {
3823 struct page *page = pvec.pages[i];
3825 if (!PagePrivate(page))
3828 if (!wbc->range_cyclic && page->index > end) {
3833 spin_lock(&mapping->private_lock);
3834 if (!PagePrivate(page)) {
3835 spin_unlock(&mapping->private_lock);
3839 eb = (struct extent_buffer *)page->private;
3842 * Shouldn't happen and normally this would be a BUG_ON
3843 * but no sense in crashing the users box for something
3844 * we can survive anyway.
3847 spin_unlock(&mapping->private_lock);
3851 if (eb == prev_eb) {
3852 spin_unlock(&mapping->private_lock);
3856 ret = atomic_inc_not_zero(&eb->refs);
3857 spin_unlock(&mapping->private_lock);
3862 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3864 free_extent_buffer(eb);
3868 ret = write_one_eb(eb, fs_info, wbc, &epd);
3871 free_extent_buffer(eb);
3874 free_extent_buffer(eb);
3877 * the filesystem may choose to bump up nr_to_write.
3878 * We have to make sure to honor the new nr_to_write
3881 nr_to_write_done = wbc->nr_to_write <= 0;
3883 pagevec_release(&pvec);
3886 if (!scanned && !done) {
3888 * We hit the last page and there is more work to be done: wrap
3889 * back to the start of the file
3895 flush_write_bio(&epd);
3900 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3901 * @mapping: address space structure to write
3902 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3903 * @writepage: function called for each page
3904 * @data: data passed to writepage function
3906 * If a page is already under I/O, write_cache_pages() skips it, even
3907 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3908 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3909 * and msync() need to guarantee that all the data which was dirty at the time
3910 * the call was made get new I/O started against them. If wbc->sync_mode is
3911 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3912 * existing IO to complete.
3914 static int extent_write_cache_pages(struct extent_io_tree *tree,
3915 struct address_space *mapping,
3916 struct writeback_control *wbc,
3917 writepage_t writepage, void *data,
3918 void (*flush_fn)(void *))
3920 struct inode *inode = mapping->host;
3924 int nr_to_write_done = 0;
3925 struct pagevec pvec;
3928 pgoff_t end; /* Inclusive */
3933 * We have to hold onto the inode so that ordered extents can do their
3934 * work when the IO finishes. The alternative to this is failing to add
3935 * an ordered extent if the igrab() fails there and that is a huge pain
3936 * to deal with, so instead just hold onto the inode throughout the
3937 * writepages operation. If it fails here we are freeing up the inode
3938 * anyway and we'd rather not waste our time writing out stuff that is
3939 * going to be truncated anyway.
3944 pagevec_init(&pvec, 0);
3945 if (wbc->range_cyclic) {
3946 index = mapping->writeback_index; /* Start from prev offset */
3949 index = wbc->range_start >> PAGE_SHIFT;
3950 end = wbc->range_end >> PAGE_SHIFT;
3953 if (wbc->sync_mode == WB_SYNC_ALL)
3954 tag = PAGECACHE_TAG_TOWRITE;
3956 tag = PAGECACHE_TAG_DIRTY;
3958 if (wbc->sync_mode == WB_SYNC_ALL)
3959 tag_pages_for_writeback(mapping, index, end);
3960 while (!done && !nr_to_write_done && (index <= end) &&
3961 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3962 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3966 for (i = 0; i < nr_pages; i++) {
3967 struct page *page = pvec.pages[i];
3970 * At this point we hold neither mapping->tree_lock nor
3971 * lock on the page itself: the page may be truncated or
3972 * invalidated (changing page->mapping to NULL), or even
3973 * swizzled back from swapper_space to tmpfs file
3976 if (!trylock_page(page)) {
3981 if (unlikely(page->mapping != mapping)) {
3986 if (!wbc->range_cyclic && page->index > end) {
3992 if (wbc->sync_mode != WB_SYNC_NONE) {
3993 if (PageWriteback(page))
3995 wait_on_page_writeback(page);
3998 if (PageWriteback(page) ||
3999 !clear_page_dirty_for_io(page)) {
4004 ret = (*writepage)(page, wbc, data);
4006 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
4010 if (!err && ret < 0)
4014 * the filesystem may choose to bump up nr_to_write.
4015 * We have to make sure to honor the new nr_to_write
4018 nr_to_write_done = wbc->nr_to_write <= 0;
4020 pagevec_release(&pvec);
4023 if (!scanned && !done && !err) {
4025 * We hit the last page and there is more work to be done: wrap
4026 * back to the start of the file
4032 btrfs_add_delayed_iput(inode);
4036 static void flush_epd_write_bio(struct extent_page_data *epd)
4045 ret = submit_one_bio(rw, epd->bio, 0, epd->bio_flags);
4046 BUG_ON(ret < 0); /* -ENOMEM */
4051 static noinline void flush_write_bio(void *data)
4053 struct extent_page_data *epd = data;
4054 flush_epd_write_bio(epd);
4057 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
4058 get_extent_t *get_extent,
4059 struct writeback_control *wbc)
4062 struct extent_page_data epd = {
4065 .get_extent = get_extent,
4067 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4071 ret = __extent_writepage(page, wbc, &epd);
4073 flush_epd_write_bio(&epd);
4077 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
4078 u64 start, u64 end, get_extent_t *get_extent,
4082 struct address_space *mapping = inode->i_mapping;
4084 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4087 struct extent_page_data epd = {
4090 .get_extent = get_extent,
4092 .sync_io = mode == WB_SYNC_ALL,
4095 struct writeback_control wbc_writepages = {
4097 .nr_to_write = nr_pages * 2,
4098 .range_start = start,
4099 .range_end = end + 1,
4102 while (start <= end) {
4103 page = find_get_page(mapping, start >> PAGE_SHIFT);
4104 if (clear_page_dirty_for_io(page))
4105 ret = __extent_writepage(page, &wbc_writepages, &epd);
4107 if (tree->ops && tree->ops->writepage_end_io_hook)
4108 tree->ops->writepage_end_io_hook(page, start,
4109 start + PAGE_SIZE - 1,
4117 flush_epd_write_bio(&epd);
4121 int extent_writepages(struct extent_io_tree *tree,
4122 struct address_space *mapping,
4123 get_extent_t *get_extent,
4124 struct writeback_control *wbc)
4127 struct extent_page_data epd = {
4130 .get_extent = get_extent,
4132 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4136 ret = extent_write_cache_pages(tree, mapping, wbc,
4137 __extent_writepage, &epd,
4139 flush_epd_write_bio(&epd);
4143 int extent_readpages(struct extent_io_tree *tree,
4144 struct address_space *mapping,
4145 struct list_head *pages, unsigned nr_pages,
4146 get_extent_t get_extent)
4148 struct bio *bio = NULL;
4150 unsigned long bio_flags = 0;
4151 struct page *pagepool[16];
4153 struct extent_map *em_cached = NULL;
4155 u64 prev_em_start = (u64)-1;
4157 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
4158 page = list_entry(pages->prev, struct page, lru);
4160 prefetchw(&page->flags);
4161 list_del(&page->lru);
4162 if (add_to_page_cache_lru(page, mapping,
4163 page->index, GFP_NOFS)) {
4168 pagepool[nr++] = page;
4169 if (nr < ARRAY_SIZE(pagepool))
4171 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4172 &bio, 0, &bio_flags, READ, &prev_em_start);
4176 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4177 &bio, 0, &bio_flags, READ, &prev_em_start);
4180 free_extent_map(em_cached);
4182 BUG_ON(!list_empty(pages));
4184 return submit_one_bio(READ, bio, 0, bio_flags);
4189 * basic invalidatepage code, this waits on any locked or writeback
4190 * ranges corresponding to the page, and then deletes any extent state
4191 * records from the tree
4193 int extent_invalidatepage(struct extent_io_tree *tree,
4194 struct page *page, unsigned long offset)
4196 struct extent_state *cached_state = NULL;
4197 u64 start = page_offset(page);
4198 u64 end = start + PAGE_SIZE - 1;
4199 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4201 start += ALIGN(offset, blocksize);
4205 lock_extent_bits(tree, start, end, &cached_state);
4206 wait_on_page_writeback(page);
4207 clear_extent_bit(tree, start, end,
4208 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
4209 EXTENT_DO_ACCOUNTING,
4210 1, 1, &cached_state, GFP_NOFS);
4215 * a helper for releasepage, this tests for areas of the page that
4216 * are locked or under IO and drops the related state bits if it is safe
4219 static int try_release_extent_state(struct extent_map_tree *map,
4220 struct extent_io_tree *tree,
4221 struct page *page, gfp_t mask)
4223 u64 start = page_offset(page);
4224 u64 end = start + PAGE_SIZE - 1;
4227 if (test_range_bit(tree, start, end,
4228 EXTENT_IOBITS, 0, NULL))
4231 if ((mask & GFP_NOFS) == GFP_NOFS)
4234 * at this point we can safely clear everything except the
4235 * locked bit and the nodatasum bit
4237 ret = clear_extent_bit(tree, start, end,
4238 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4241 /* if clear_extent_bit failed for enomem reasons,
4242 * we can't allow the release to continue.
4253 * a helper for releasepage. As long as there are no locked extents
4254 * in the range corresponding to the page, both state records and extent
4255 * map records are removed
4257 int try_release_extent_mapping(struct extent_map_tree *map,
4258 struct extent_io_tree *tree, struct page *page,
4261 struct extent_map *em;
4262 u64 start = page_offset(page);
4263 u64 end = start + PAGE_SIZE - 1;
4265 if (gfpflags_allow_blocking(mask) &&
4266 page->mapping->host->i_size > SZ_16M) {
4268 while (start <= end) {
4269 len = end - start + 1;
4270 write_lock(&map->lock);
4271 em = lookup_extent_mapping(map, start, len);
4273 write_unlock(&map->lock);
4276 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4277 em->start != start) {
4278 write_unlock(&map->lock);
4279 free_extent_map(em);
4282 if (!test_range_bit(tree, em->start,
4283 extent_map_end(em) - 1,
4284 EXTENT_LOCKED | EXTENT_WRITEBACK,
4286 remove_extent_mapping(map, em);
4287 /* once for the rb tree */
4288 free_extent_map(em);
4290 start = extent_map_end(em);
4291 write_unlock(&map->lock);
4294 free_extent_map(em);
4297 return try_release_extent_state(map, tree, page, mask);
4301 * helper function for fiemap, which doesn't want to see any holes.
4302 * This maps until we find something past 'last'
4304 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4307 get_extent_t *get_extent)
4309 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
4310 struct extent_map *em;
4317 len = last - offset;
4320 len = ALIGN(len, sectorsize);
4321 em = get_extent(inode, NULL, 0, offset, len, 0);
4322 if (IS_ERR_OR_NULL(em))
4325 /* if this isn't a hole return it */
4326 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
4327 em->block_start != EXTENT_MAP_HOLE) {
4331 /* this is a hole, advance to the next extent */
4332 offset = extent_map_end(em);
4333 free_extent_map(em);
4340 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4341 __u64 start, __u64 len, get_extent_t *get_extent)
4345 u64 max = start + len;
4349 u64 last_for_get_extent = 0;
4351 u64 isize = i_size_read(inode);
4352 struct btrfs_key found_key;
4353 struct extent_map *em = NULL;
4354 struct extent_state *cached_state = NULL;
4355 struct btrfs_path *path;
4356 struct btrfs_root *root = BTRFS_I(inode)->root;
4365 path = btrfs_alloc_path();
4368 path->leave_spinning = 1;
4370 start = round_down(start, BTRFS_I(inode)->root->sectorsize);
4371 len = round_up(max, BTRFS_I(inode)->root->sectorsize) - start;
4374 * lookup the last file extent. We're not using i_size here
4375 * because there might be preallocation past i_size
4377 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), -1,
4380 btrfs_free_path(path);
4385 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4386 found_type = found_key.type;
4388 /* No extents, but there might be delalloc bits */
4389 if (found_key.objectid != btrfs_ino(inode) ||
4390 found_type != BTRFS_EXTENT_DATA_KEY) {
4391 /* have to trust i_size as the end */
4393 last_for_get_extent = isize;
4396 * remember the start of the last extent. There are a
4397 * bunch of different factors that go into the length of the
4398 * extent, so its much less complex to remember where it started
4400 last = found_key.offset;
4401 last_for_get_extent = last + 1;
4403 btrfs_release_path(path);
4406 * we might have some extents allocated but more delalloc past those
4407 * extents. so, we trust isize unless the start of the last extent is
4412 last_for_get_extent = isize;
4415 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4418 em = get_extent_skip_holes(inode, start, last_for_get_extent,
4428 u64 offset_in_extent = 0;
4430 /* break if the extent we found is outside the range */
4431 if (em->start >= max || extent_map_end(em) < off)
4435 * get_extent may return an extent that starts before our
4436 * requested range. We have to make sure the ranges
4437 * we return to fiemap always move forward and don't
4438 * overlap, so adjust the offsets here
4440 em_start = max(em->start, off);
4443 * record the offset from the start of the extent
4444 * for adjusting the disk offset below. Only do this if the
4445 * extent isn't compressed since our in ram offset may be past
4446 * what we have actually allocated on disk.
4448 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4449 offset_in_extent = em_start - em->start;
4450 em_end = extent_map_end(em);
4451 em_len = em_end - em_start;
4456 * bump off for our next call to get_extent
4458 off = extent_map_end(em);
4462 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4464 flags |= FIEMAP_EXTENT_LAST;
4465 } else if (em->block_start == EXTENT_MAP_INLINE) {
4466 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4467 FIEMAP_EXTENT_NOT_ALIGNED);
4468 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4469 flags |= (FIEMAP_EXTENT_DELALLOC |
4470 FIEMAP_EXTENT_UNKNOWN);
4471 } else if (fieinfo->fi_extents_max) {
4472 u64 bytenr = em->block_start -
4473 (em->start - em->orig_start);
4475 disko = em->block_start + offset_in_extent;
4478 * As btrfs supports shared space, this information
4479 * can be exported to userspace tools via
4480 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4481 * then we're just getting a count and we can skip the
4484 ret = btrfs_check_shared(NULL, root->fs_info,
4486 btrfs_ino(inode), bytenr);
4490 flags |= FIEMAP_EXTENT_SHARED;
4493 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4494 flags |= FIEMAP_EXTENT_ENCODED;
4495 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4496 flags |= FIEMAP_EXTENT_UNWRITTEN;
4498 free_extent_map(em);
4500 if ((em_start >= last) || em_len == (u64)-1 ||
4501 (last == (u64)-1 && isize <= em_end)) {
4502 flags |= FIEMAP_EXTENT_LAST;
4506 /* now scan forward to see if this is really the last extent. */
4507 em = get_extent_skip_holes(inode, off, last_for_get_extent,
4514 flags |= FIEMAP_EXTENT_LAST;
4517 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
4526 free_extent_map(em);
4528 btrfs_free_path(path);
4529 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4530 &cached_state, GFP_NOFS);
4534 static void __free_extent_buffer(struct extent_buffer *eb)
4536 btrfs_leak_debug_del(&eb->leak_list);
4537 kmem_cache_free(extent_buffer_cache, eb);
4540 int extent_buffer_under_io(struct extent_buffer *eb)
4542 return (atomic_read(&eb->io_pages) ||
4543 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4544 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4548 * Helper for releasing extent buffer page.
4550 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb)
4552 unsigned long index;
4554 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4556 BUG_ON(extent_buffer_under_io(eb));
4558 index = num_extent_pages(eb->start, eb->len);
4564 page = eb->pages[index];
4568 spin_lock(&page->mapping->private_lock);
4570 * We do this since we'll remove the pages after we've
4571 * removed the eb from the radix tree, so we could race
4572 * and have this page now attached to the new eb. So
4573 * only clear page_private if it's still connected to
4576 if (PagePrivate(page) &&
4577 page->private == (unsigned long)eb) {
4578 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4579 BUG_ON(PageDirty(page));
4580 BUG_ON(PageWriteback(page));
4582 * We need to make sure we haven't be attached
4585 ClearPagePrivate(page);
4586 set_page_private(page, 0);
4587 /* One for the page private */
4592 spin_unlock(&page->mapping->private_lock);
4594 /* One for when we alloced the page */
4596 } while (index != 0);
4600 * Helper for releasing the extent buffer.
4602 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4604 btrfs_release_extent_buffer_page(eb);
4605 __free_extent_buffer(eb);
4608 static struct extent_buffer *
4609 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4612 struct extent_buffer *eb = NULL;
4614 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4617 eb->fs_info = fs_info;
4619 rwlock_init(&eb->lock);
4620 atomic_set(&eb->write_locks, 0);
4621 atomic_set(&eb->read_locks, 0);
4622 atomic_set(&eb->blocking_readers, 0);
4623 atomic_set(&eb->blocking_writers, 0);
4624 atomic_set(&eb->spinning_readers, 0);
4625 atomic_set(&eb->spinning_writers, 0);
4626 eb->lock_nested = 0;
4627 init_waitqueue_head(&eb->write_lock_wq);
4628 init_waitqueue_head(&eb->read_lock_wq);
4630 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4632 spin_lock_init(&eb->refs_lock);
4633 atomic_set(&eb->refs, 1);
4634 atomic_set(&eb->io_pages, 0);
4637 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4639 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4640 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4641 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4646 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4650 struct extent_buffer *new;
4651 unsigned long num_pages = num_extent_pages(src->start, src->len);
4653 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
4657 for (i = 0; i < num_pages; i++) {
4658 p = alloc_page(GFP_NOFS);
4660 btrfs_release_extent_buffer(new);
4663 attach_extent_buffer_page(new, p);
4664 WARN_ON(PageDirty(p));
4669 copy_extent_buffer(new, src, 0, 0, src->len);
4670 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4671 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4676 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4677 u64 start, unsigned long len)
4679 struct extent_buffer *eb;
4680 unsigned long num_pages;
4683 num_pages = num_extent_pages(start, len);
4685 eb = __alloc_extent_buffer(fs_info, start, len);
4689 for (i = 0; i < num_pages; i++) {
4690 eb->pages[i] = alloc_page(GFP_NOFS);
4694 set_extent_buffer_uptodate(eb);
4695 btrfs_set_header_nritems(eb, 0);
4696 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4701 __free_page(eb->pages[i - 1]);
4702 __free_extent_buffer(eb);
4706 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4713 * Called only from tests that don't always have a fs_info
4714 * available, but we know that nodesize is 4096
4718 len = fs_info->tree_root->nodesize;
4721 return __alloc_dummy_extent_buffer(fs_info, start, len);
4724 static void check_buffer_tree_ref(struct extent_buffer *eb)
4727 /* the ref bit is tricky. We have to make sure it is set
4728 * if we have the buffer dirty. Otherwise the
4729 * code to free a buffer can end up dropping a dirty
4732 * Once the ref bit is set, it won't go away while the
4733 * buffer is dirty or in writeback, and it also won't
4734 * go away while we have the reference count on the
4737 * We can't just set the ref bit without bumping the
4738 * ref on the eb because free_extent_buffer might
4739 * see the ref bit and try to clear it. If this happens
4740 * free_extent_buffer might end up dropping our original
4741 * ref by mistake and freeing the page before we are able
4742 * to add one more ref.
4744 * So bump the ref count first, then set the bit. If someone
4745 * beat us to it, drop the ref we added.
4747 refs = atomic_read(&eb->refs);
4748 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4751 spin_lock(&eb->refs_lock);
4752 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4753 atomic_inc(&eb->refs);
4754 spin_unlock(&eb->refs_lock);
4757 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
4758 struct page *accessed)
4760 unsigned long num_pages, i;
4762 check_buffer_tree_ref(eb);
4764 num_pages = num_extent_pages(eb->start, eb->len);
4765 for (i = 0; i < num_pages; i++) {
4766 struct page *p = eb->pages[i];
4769 mark_page_accessed(p);
4773 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
4776 struct extent_buffer *eb;
4779 eb = radix_tree_lookup(&fs_info->buffer_radix,
4780 start >> PAGE_SHIFT);
4781 if (eb && atomic_inc_not_zero(&eb->refs)) {
4784 * Lock our eb's refs_lock to avoid races with
4785 * free_extent_buffer. When we get our eb it might be flagged
4786 * with EXTENT_BUFFER_STALE and another task running
4787 * free_extent_buffer might have seen that flag set,
4788 * eb->refs == 2, that the buffer isn't under IO (dirty and
4789 * writeback flags not set) and it's still in the tree (flag
4790 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4791 * of decrementing the extent buffer's reference count twice.
4792 * So here we could race and increment the eb's reference count,
4793 * clear its stale flag, mark it as dirty and drop our reference
4794 * before the other task finishes executing free_extent_buffer,
4795 * which would later result in an attempt to free an extent
4796 * buffer that is dirty.
4798 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
4799 spin_lock(&eb->refs_lock);
4800 spin_unlock(&eb->refs_lock);
4802 mark_extent_buffer_accessed(eb, NULL);
4810 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4811 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
4814 struct extent_buffer *eb, *exists = NULL;
4817 eb = find_extent_buffer(fs_info, start);
4820 eb = alloc_dummy_extent_buffer(fs_info, start);
4823 eb->fs_info = fs_info;
4825 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
4828 spin_lock(&fs_info->buffer_lock);
4829 ret = radix_tree_insert(&fs_info->buffer_radix,
4830 start >> PAGE_SHIFT, eb);
4831 spin_unlock(&fs_info->buffer_lock);
4832 radix_tree_preload_end();
4833 if (ret == -EEXIST) {
4834 exists = find_extent_buffer(fs_info, start);
4840 check_buffer_tree_ref(eb);
4841 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4844 * We will free dummy extent buffer's if they come into
4845 * free_extent_buffer with a ref count of 2, but if we are using this we
4846 * want the buffers to stay in memory until we're done with them, so
4847 * bump the ref count again.
4849 atomic_inc(&eb->refs);
4852 btrfs_release_extent_buffer(eb);
4857 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
4860 unsigned long len = fs_info->tree_root->nodesize;
4861 unsigned long num_pages = num_extent_pages(start, len);
4863 unsigned long index = start >> PAGE_SHIFT;
4864 struct extent_buffer *eb;
4865 struct extent_buffer *exists = NULL;
4867 struct address_space *mapping = fs_info->btree_inode->i_mapping;
4871 eb = find_extent_buffer(fs_info, start);
4875 eb = __alloc_extent_buffer(fs_info, start, len);
4879 for (i = 0; i < num_pages; i++, index++) {
4880 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
4884 spin_lock(&mapping->private_lock);
4885 if (PagePrivate(p)) {
4887 * We could have already allocated an eb for this page
4888 * and attached one so lets see if we can get a ref on
4889 * the existing eb, and if we can we know it's good and
4890 * we can just return that one, else we know we can just
4891 * overwrite page->private.
4893 exists = (struct extent_buffer *)p->private;
4894 if (atomic_inc_not_zero(&exists->refs)) {
4895 spin_unlock(&mapping->private_lock);
4898 mark_extent_buffer_accessed(exists, p);
4904 * Do this so attach doesn't complain and we need to
4905 * drop the ref the old guy had.
4907 ClearPagePrivate(p);
4908 WARN_ON(PageDirty(p));
4911 attach_extent_buffer_page(eb, p);
4912 spin_unlock(&mapping->private_lock);
4913 WARN_ON(PageDirty(p));
4915 if (!PageUptodate(p))
4919 * see below about how we avoid a nasty race with release page
4920 * and why we unlock later
4924 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4926 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
4930 spin_lock(&fs_info->buffer_lock);
4931 ret = radix_tree_insert(&fs_info->buffer_radix,
4932 start >> PAGE_SHIFT, eb);
4933 spin_unlock(&fs_info->buffer_lock);
4934 radix_tree_preload_end();
4935 if (ret == -EEXIST) {
4936 exists = find_extent_buffer(fs_info, start);
4942 /* add one reference for the tree */
4943 check_buffer_tree_ref(eb);
4944 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4947 * there is a race where release page may have
4948 * tried to find this extent buffer in the radix
4949 * but failed. It will tell the VM it is safe to
4950 * reclaim the, and it will clear the page private bit.
4951 * We must make sure to set the page private bit properly
4952 * after the extent buffer is in the radix tree so
4953 * it doesn't get lost
4955 SetPageChecked(eb->pages[0]);
4956 for (i = 1; i < num_pages; i++) {
4958 ClearPageChecked(p);
4961 unlock_page(eb->pages[0]);
4965 WARN_ON(!atomic_dec_and_test(&eb->refs));
4966 for (i = 0; i < num_pages; i++) {
4968 unlock_page(eb->pages[i]);
4971 btrfs_release_extent_buffer(eb);
4975 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4977 struct extent_buffer *eb =
4978 container_of(head, struct extent_buffer, rcu_head);
4980 __free_extent_buffer(eb);
4983 /* Expects to have eb->eb_lock already held */
4984 static int release_extent_buffer(struct extent_buffer *eb)
4986 WARN_ON(atomic_read(&eb->refs) == 0);
4987 if (atomic_dec_and_test(&eb->refs)) {
4988 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
4989 struct btrfs_fs_info *fs_info = eb->fs_info;
4991 spin_unlock(&eb->refs_lock);
4993 spin_lock(&fs_info->buffer_lock);
4994 radix_tree_delete(&fs_info->buffer_radix,
4995 eb->start >> PAGE_SHIFT);
4996 spin_unlock(&fs_info->buffer_lock);
4998 spin_unlock(&eb->refs_lock);
5001 /* Should be safe to release our pages at this point */
5002 btrfs_release_extent_buffer_page(eb);
5003 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5004 if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) {
5005 __free_extent_buffer(eb);
5009 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5012 spin_unlock(&eb->refs_lock);
5017 void free_extent_buffer(struct extent_buffer *eb)
5025 refs = atomic_read(&eb->refs);
5028 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5033 spin_lock(&eb->refs_lock);
5034 if (atomic_read(&eb->refs) == 2 &&
5035 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
5036 atomic_dec(&eb->refs);
5038 if (atomic_read(&eb->refs) == 2 &&
5039 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5040 !extent_buffer_under_io(eb) &&
5041 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5042 atomic_dec(&eb->refs);
5045 * I know this is terrible, but it's temporary until we stop tracking
5046 * the uptodate bits and such for the extent buffers.
5048 release_extent_buffer(eb);
5051 void free_extent_buffer_stale(struct extent_buffer *eb)
5056 spin_lock(&eb->refs_lock);
5057 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5059 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5060 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5061 atomic_dec(&eb->refs);
5062 release_extent_buffer(eb);
5065 void clear_extent_buffer_dirty(struct extent_buffer *eb)
5068 unsigned long num_pages;
5071 num_pages = num_extent_pages(eb->start, eb->len);
5073 for (i = 0; i < num_pages; i++) {
5074 page = eb->pages[i];
5075 if (!PageDirty(page))
5079 WARN_ON(!PagePrivate(page));
5081 clear_page_dirty_for_io(page);
5082 spin_lock_irq(&page->mapping->tree_lock);
5083 if (!PageDirty(page)) {
5084 radix_tree_tag_clear(&page->mapping->page_tree,
5086 PAGECACHE_TAG_DIRTY);
5088 spin_unlock_irq(&page->mapping->tree_lock);
5089 ClearPageError(page);
5092 WARN_ON(atomic_read(&eb->refs) == 0);
5095 int set_extent_buffer_dirty(struct extent_buffer *eb)
5098 unsigned long num_pages;
5101 check_buffer_tree_ref(eb);
5103 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5105 num_pages = num_extent_pages(eb->start, eb->len);
5106 WARN_ON(atomic_read(&eb->refs) == 0);
5107 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5109 for (i = 0; i < num_pages; i++)
5110 set_page_dirty(eb->pages[i]);
5114 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5118 unsigned long num_pages;
5120 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5121 num_pages = num_extent_pages(eb->start, eb->len);
5122 for (i = 0; i < num_pages; i++) {
5123 page = eb->pages[i];
5125 ClearPageUptodate(page);
5129 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5133 unsigned long num_pages;
5135 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5136 num_pages = num_extent_pages(eb->start, eb->len);
5137 for (i = 0; i < num_pages; i++) {
5138 page = eb->pages[i];
5139 SetPageUptodate(page);
5143 int extent_buffer_uptodate(struct extent_buffer *eb)
5145 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5148 int read_extent_buffer_pages(struct extent_io_tree *tree,
5149 struct extent_buffer *eb, u64 start, int wait,
5150 get_extent_t *get_extent, int mirror_num)
5153 unsigned long start_i;
5157 int locked_pages = 0;
5158 int all_uptodate = 1;
5159 unsigned long num_pages;
5160 unsigned long num_reads = 0;
5161 struct bio *bio = NULL;
5162 unsigned long bio_flags = 0;
5164 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5168 WARN_ON(start < eb->start);
5169 start_i = (start >> PAGE_SHIFT) -
5170 (eb->start >> PAGE_SHIFT);
5175 num_pages = num_extent_pages(eb->start, eb->len);
5176 for (i = start_i; i < num_pages; i++) {
5177 page = eb->pages[i];
5178 if (wait == WAIT_NONE) {
5179 if (!trylock_page(page))
5185 if (!PageUptodate(page)) {
5192 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5196 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5197 eb->read_mirror = 0;
5198 atomic_set(&eb->io_pages, num_reads);
5199 for (i = start_i; i < num_pages; i++) {
5200 page = eb->pages[i];
5201 if (!PageUptodate(page)) {
5202 ClearPageError(page);
5203 err = __extent_read_full_page(tree, page,
5205 mirror_num, &bio_flags,
5215 err = submit_one_bio(READ | REQ_META, bio, mirror_num,
5221 if (ret || wait != WAIT_COMPLETE)
5224 for (i = start_i; i < num_pages; i++) {
5225 page = eb->pages[i];
5226 wait_on_page_locked(page);
5227 if (!PageUptodate(page))
5235 while (locked_pages > 0) {
5236 page = eb->pages[i];
5244 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
5245 unsigned long start,
5252 char *dst = (char *)dstv;
5253 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5254 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5256 WARN_ON(start > eb->len);
5257 WARN_ON(start + len > eb->start + eb->len);
5259 offset = (start_offset + start) & (PAGE_SIZE - 1);
5262 page = eb->pages[i];
5264 cur = min(len, (PAGE_SIZE - offset));
5265 kaddr = page_address(page);
5266 memcpy(dst, kaddr + offset, cur);
5275 int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv,
5276 unsigned long start,
5283 char __user *dst = (char __user *)dstv;
5284 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5285 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5288 WARN_ON(start > eb->len);
5289 WARN_ON(start + len > eb->start + eb->len);
5291 offset = (start_offset + start) & (PAGE_SIZE - 1);
5294 page = eb->pages[i];
5296 cur = min(len, (PAGE_SIZE - offset));
5297 kaddr = page_address(page);
5298 if (copy_to_user(dst, kaddr + offset, cur)) {
5312 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
5313 unsigned long min_len, char **map,
5314 unsigned long *map_start,
5315 unsigned long *map_len)
5317 size_t offset = start & (PAGE_SIZE - 1);
5320 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5321 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5322 unsigned long end_i = (start_offset + start + min_len - 1) >>
5329 offset = start_offset;
5333 *map_start = ((u64)i << PAGE_SHIFT) - start_offset;
5336 if (start + min_len > eb->len) {
5337 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
5339 eb->start, eb->len, start, min_len);
5344 kaddr = page_address(p);
5345 *map = kaddr + offset;
5346 *map_len = PAGE_SIZE - offset;
5350 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
5351 unsigned long start,
5358 char *ptr = (char *)ptrv;
5359 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5360 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5363 WARN_ON(start > eb->len);
5364 WARN_ON(start + len > eb->start + eb->len);
5366 offset = (start_offset + start) & (PAGE_SIZE - 1);
5369 page = eb->pages[i];
5371 cur = min(len, (PAGE_SIZE - offset));
5373 kaddr = page_address(page);
5374 ret = memcmp(ptr, kaddr + offset, cur);
5386 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
5387 unsigned long start, unsigned long len)
5393 char *src = (char *)srcv;
5394 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5395 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5397 WARN_ON(start > eb->len);
5398 WARN_ON(start + len > eb->start + eb->len);
5400 offset = (start_offset + start) & (PAGE_SIZE - 1);
5403 page = eb->pages[i];
5404 WARN_ON(!PageUptodate(page));
5406 cur = min(len, PAGE_SIZE - offset);
5407 kaddr = page_address(page);
5408 memcpy(kaddr + offset, src, cur);
5417 void memset_extent_buffer(struct extent_buffer *eb, char c,
5418 unsigned long start, unsigned long len)
5424 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5425 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5427 WARN_ON(start > eb->len);
5428 WARN_ON(start + len > eb->start + eb->len);
5430 offset = (start_offset + start) & (PAGE_SIZE - 1);
5433 page = eb->pages[i];
5434 WARN_ON(!PageUptodate(page));
5436 cur = min(len, PAGE_SIZE - offset);
5437 kaddr = page_address(page);
5438 memset(kaddr + offset, c, cur);
5446 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5447 unsigned long dst_offset, unsigned long src_offset,
5450 u64 dst_len = dst->len;
5455 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5456 unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
5458 WARN_ON(src->len != dst_len);
5460 offset = (start_offset + dst_offset) &
5464 page = dst->pages[i];
5465 WARN_ON(!PageUptodate(page));
5467 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5469 kaddr = page_address(page);
5470 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5480 * The extent buffer bitmap operations are done with byte granularity because
5481 * bitmap items are not guaranteed to be aligned to a word and therefore a
5482 * single word in a bitmap may straddle two pages in the extent buffer.
5484 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
5485 #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
5486 #define BITMAP_FIRST_BYTE_MASK(start) \
5487 ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
5488 #define BITMAP_LAST_BYTE_MASK(nbits) \
5489 (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
5492 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5494 * @eb: the extent buffer
5495 * @start: offset of the bitmap item in the extent buffer
5497 * @page_index: return index of the page in the extent buffer that contains the
5499 * @page_offset: return offset into the page given by page_index
5501 * This helper hides the ugliness of finding the byte in an extent buffer which
5502 * contains a given bit.
5504 static inline void eb_bitmap_offset(struct extent_buffer *eb,
5505 unsigned long start, unsigned long nr,
5506 unsigned long *page_index,
5507 size_t *page_offset)
5509 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5510 size_t byte_offset = BIT_BYTE(nr);
5514 * The byte we want is the offset of the extent buffer + the offset of
5515 * the bitmap item in the extent buffer + the offset of the byte in the
5518 offset = start_offset + start + byte_offset;
5520 *page_index = offset >> PAGE_SHIFT;
5521 *page_offset = offset & (PAGE_SIZE - 1);
5525 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5526 * @eb: the extent buffer
5527 * @start: offset of the bitmap item in the extent buffer
5528 * @nr: bit number to test
5530 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
5538 eb_bitmap_offset(eb, start, nr, &i, &offset);
5539 page = eb->pages[i];
5540 WARN_ON(!PageUptodate(page));
5541 kaddr = page_address(page);
5542 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5546 * extent_buffer_bitmap_set - set an area of a bitmap
5547 * @eb: the extent buffer
5548 * @start: offset of the bitmap item in the extent buffer
5549 * @pos: bit number of the first bit
5550 * @len: number of bits to set
5552 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
5553 unsigned long pos, unsigned long len)
5559 const unsigned int size = pos + len;
5560 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5561 unsigned int mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5563 eb_bitmap_offset(eb, start, pos, &i, &offset);
5564 page = eb->pages[i];
5565 WARN_ON(!PageUptodate(page));
5566 kaddr = page_address(page);
5568 while (len >= bits_to_set) {
5569 kaddr[offset] |= mask_to_set;
5571 bits_to_set = BITS_PER_BYTE;
5573 if (++offset >= PAGE_SIZE && len > 0) {
5575 page = eb->pages[++i];
5576 WARN_ON(!PageUptodate(page));
5577 kaddr = page_address(page);
5581 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5582 kaddr[offset] |= mask_to_set;
5588 * extent_buffer_bitmap_clear - clear an area of a bitmap
5589 * @eb: the extent buffer
5590 * @start: offset of the bitmap item in the extent buffer
5591 * @pos: bit number of the first bit
5592 * @len: number of bits to clear
5594 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
5595 unsigned long pos, unsigned long len)
5601 const unsigned int size = pos + len;
5602 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5603 unsigned int mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5605 eb_bitmap_offset(eb, start, pos, &i, &offset);
5606 page = eb->pages[i];
5607 WARN_ON(!PageUptodate(page));
5608 kaddr = page_address(page);
5610 while (len >= bits_to_clear) {
5611 kaddr[offset] &= ~mask_to_clear;
5612 len -= bits_to_clear;
5613 bits_to_clear = BITS_PER_BYTE;
5614 mask_to_clear = ~0U;
5615 if (++offset >= PAGE_SIZE && len > 0) {
5617 page = eb->pages[++i];
5618 WARN_ON(!PageUptodate(page));
5619 kaddr = page_address(page);
5623 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5624 kaddr[offset] &= ~mask_to_clear;
5628 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5630 unsigned long distance = (src > dst) ? src - dst : dst - src;
5631 return distance < len;
5634 static void copy_pages(struct page *dst_page, struct page *src_page,
5635 unsigned long dst_off, unsigned long src_off,
5638 char *dst_kaddr = page_address(dst_page);
5640 int must_memmove = 0;
5642 if (dst_page != src_page) {
5643 src_kaddr = page_address(src_page);
5645 src_kaddr = dst_kaddr;
5646 if (areas_overlap(src_off, dst_off, len))
5651 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5653 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5656 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5657 unsigned long src_offset, unsigned long len)
5660 size_t dst_off_in_page;
5661 size_t src_off_in_page;
5662 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5663 unsigned long dst_i;
5664 unsigned long src_i;
5666 if (src_offset + len > dst->len) {
5667 btrfs_err(dst->fs_info,
5668 "memmove bogus src_offset %lu move "
5669 "len %lu dst len %lu", src_offset, len, dst->len);
5672 if (dst_offset + len > dst->len) {
5673 btrfs_err(dst->fs_info,
5674 "memmove bogus dst_offset %lu move "
5675 "len %lu dst len %lu", dst_offset, len, dst->len);
5680 dst_off_in_page = (start_offset + dst_offset) &
5682 src_off_in_page = (start_offset + src_offset) &
5685 dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
5686 src_i = (start_offset + src_offset) >> PAGE_SHIFT;
5688 cur = min(len, (unsigned long)(PAGE_SIZE -
5690 cur = min_t(unsigned long, cur,
5691 (unsigned long)(PAGE_SIZE - dst_off_in_page));
5693 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5694 dst_off_in_page, src_off_in_page, cur);
5702 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5703 unsigned long src_offset, unsigned long len)
5706 size_t dst_off_in_page;
5707 size_t src_off_in_page;
5708 unsigned long dst_end = dst_offset + len - 1;
5709 unsigned long src_end = src_offset + len - 1;
5710 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5711 unsigned long dst_i;
5712 unsigned long src_i;
5714 if (src_offset + len > dst->len) {
5715 btrfs_err(dst->fs_info, "memmove bogus src_offset %lu move "
5716 "len %lu len %lu", src_offset, len, dst->len);
5719 if (dst_offset + len > dst->len) {
5720 btrfs_err(dst->fs_info, "memmove bogus dst_offset %lu move "
5721 "len %lu len %lu", dst_offset, len, dst->len);
5724 if (dst_offset < src_offset) {
5725 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5729 dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
5730 src_i = (start_offset + src_end) >> PAGE_SHIFT;
5732 dst_off_in_page = (start_offset + dst_end) &
5734 src_off_in_page = (start_offset + src_end) &
5737 cur = min_t(unsigned long, len, src_off_in_page + 1);
5738 cur = min(cur, dst_off_in_page + 1);
5739 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5740 dst_off_in_page - cur + 1,
5741 src_off_in_page - cur + 1, cur);
5749 int try_release_extent_buffer(struct page *page)
5751 struct extent_buffer *eb;
5754 * We need to make sure noboody is attaching this page to an eb right
5757 spin_lock(&page->mapping->private_lock);
5758 if (!PagePrivate(page)) {
5759 spin_unlock(&page->mapping->private_lock);
5763 eb = (struct extent_buffer *)page->private;
5767 * This is a little awful but should be ok, we need to make sure that
5768 * the eb doesn't disappear out from under us while we're looking at
5771 spin_lock(&eb->refs_lock);
5772 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5773 spin_unlock(&eb->refs_lock);
5774 spin_unlock(&page->mapping->private_lock);
5777 spin_unlock(&page->mapping->private_lock);
5780 * If tree ref isn't set then we know the ref on this eb is a real ref,
5781 * so just return, this page will likely be freed soon anyway.
5783 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5784 spin_unlock(&eb->refs_lock);
5788 return release_extent_buffer(eb);