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_MEM_SPREAD, NULL);
167 if (!extent_state_cache)
170 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
171 sizeof(struct extent_buffer), 0,
172 SLAB_MEM_SPREAD, NULL);
173 if (!extent_buffer_cache)
174 goto free_state_cache;
176 btrfs_bioset = bioset_create(BIO_POOL_SIZE,
177 offsetof(struct btrfs_io_bio, bio));
179 goto free_buffer_cache;
181 if (bioset_integrity_create(btrfs_bioset, BIO_POOL_SIZE))
187 bioset_free(btrfs_bioset);
191 kmem_cache_destroy(extent_buffer_cache);
192 extent_buffer_cache = NULL;
195 kmem_cache_destroy(extent_state_cache);
196 extent_state_cache = NULL;
200 void extent_io_exit(void)
202 btrfs_leak_debug_check();
205 * Make sure all delayed rcu free are flushed before we
209 kmem_cache_destroy(extent_state_cache);
210 kmem_cache_destroy(extent_buffer_cache);
212 bioset_free(btrfs_bioset);
215 void extent_io_tree_init(struct extent_io_tree *tree,
216 struct address_space *mapping)
218 tree->state = RB_ROOT;
220 tree->dirty_bytes = 0;
221 spin_lock_init(&tree->lock);
222 tree->mapping = mapping;
225 static struct extent_state *alloc_extent_state(gfp_t mask)
227 struct extent_state *state;
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())
733 spin_unlock(&tree->lock);
734 if (gfpflags_allow_blocking(mask))
739 spin_unlock(&tree->lock);
741 free_extent_state(prealloc);
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)) {
877 * Don't care for allocation failure here because we might end
878 * up not needing the pre-allocated extent state at all, which
879 * is the case if we only have in the tree extent states that
880 * cover our input range and don't cover too any other range.
881 * If we end up needing a new extent state we allocate it later.
883 prealloc = alloc_extent_state(mask);
886 spin_lock(&tree->lock);
887 if (cached_state && *cached_state) {
888 state = *cached_state;
889 if (state->start <= start && state->end > start &&
890 extent_state_in_tree(state)) {
891 node = &state->rb_node;
896 * this search will find all the extents that end after
899 node = tree_search_for_insert(tree, start, &p, &parent);
901 prealloc = alloc_extent_state_atomic(prealloc);
903 err = insert_state(tree, prealloc, start, end,
904 &p, &parent, &bits, changeset);
906 extent_io_tree_panic(tree, err);
908 cache_state(prealloc, cached_state);
912 state = rb_entry(node, struct extent_state, rb_node);
914 last_start = state->start;
915 last_end = state->end;
918 * | ---- desired range ---- |
921 * Just lock what we found and keep going
923 if (state->start == start && state->end <= end) {
924 if (state->state & exclusive_bits) {
925 *failed_start = state->start;
930 set_state_bits(tree, state, &bits, changeset);
931 cache_state(state, cached_state);
932 merge_state(tree, state);
933 if (last_end == (u64)-1)
935 start = last_end + 1;
936 state = next_state(state);
937 if (start < end && state && state->start == start &&
944 * | ---- desired range ---- |
947 * | ------------- state -------------- |
949 * We need to split the extent we found, and may flip bits on
952 * If the extent we found extends past our
953 * range, we just split and search again. It'll get split
954 * again the next time though.
956 * If the extent we found is inside our range, we set the
959 if (state->start < start) {
960 if (state->state & exclusive_bits) {
961 *failed_start = start;
966 prealloc = alloc_extent_state_atomic(prealloc);
968 err = split_state(tree, state, prealloc, start);
970 extent_io_tree_panic(tree, err);
975 if (state->end <= end) {
976 set_state_bits(tree, state, &bits, changeset);
977 cache_state(state, cached_state);
978 merge_state(tree, state);
979 if (last_end == (u64)-1)
981 start = last_end + 1;
982 state = next_state(state);
983 if (start < end && state && state->start == start &&
990 * | ---- desired range ---- |
991 * | state | or | state |
993 * There's a hole, we need to insert something in it and
994 * ignore the extent we found.
996 if (state->start > start) {
998 if (end < last_start)
1001 this_end = last_start - 1;
1003 prealloc = alloc_extent_state_atomic(prealloc);
1007 * Avoid to free 'prealloc' if it can be merged with
1010 err = insert_state(tree, prealloc, start, this_end,
1011 NULL, NULL, &bits, changeset);
1013 extent_io_tree_panic(tree, err);
1015 cache_state(prealloc, cached_state);
1017 start = this_end + 1;
1021 * | ---- desired range ---- |
1023 * We need to split the extent, and set the bit
1026 if (state->start <= end && state->end > end) {
1027 if (state->state & exclusive_bits) {
1028 *failed_start = start;
1033 prealloc = alloc_extent_state_atomic(prealloc);
1035 err = split_state(tree, state, prealloc, end + 1);
1037 extent_io_tree_panic(tree, err);
1039 set_state_bits(tree, prealloc, &bits, changeset);
1040 cache_state(prealloc, cached_state);
1041 merge_state(tree, prealloc);
1049 spin_unlock(&tree->lock);
1050 if (gfpflags_allow_blocking(mask))
1055 spin_unlock(&tree->lock);
1057 free_extent_state(prealloc);
1063 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1064 unsigned bits, u64 * failed_start,
1065 struct extent_state **cached_state, gfp_t mask)
1067 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
1068 cached_state, mask, NULL);
1073 * convert_extent_bit - convert all bits in a given range from one bit to
1075 * @tree: the io tree to search
1076 * @start: the start offset in bytes
1077 * @end: the end offset in bytes (inclusive)
1078 * @bits: the bits to set in this range
1079 * @clear_bits: the bits to clear in this range
1080 * @cached_state: state that we're going to cache
1082 * This will go through and set bits for the given range. If any states exist
1083 * already in this range they are set with the given bit and cleared of the
1084 * clear_bits. This is only meant to be used by things that are mergeable, ie
1085 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1086 * boundary bits like LOCK.
1088 * All allocations are done with GFP_NOFS.
1090 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1091 unsigned bits, unsigned clear_bits,
1092 struct extent_state **cached_state)
1094 struct extent_state *state;
1095 struct extent_state *prealloc = NULL;
1096 struct rb_node *node;
1098 struct rb_node *parent;
1102 bool first_iteration = true;
1104 btrfs_debug_check_extent_io_range(tree, start, end);
1109 * Best effort, don't worry if extent state allocation fails
1110 * here for the first iteration. We might have a cached state
1111 * that matches exactly the target range, in which case no
1112 * extent state allocations are needed. We'll only know this
1113 * after locking the tree.
1115 prealloc = alloc_extent_state(GFP_NOFS);
1116 if (!prealloc && !first_iteration)
1120 spin_lock(&tree->lock);
1121 if (cached_state && *cached_state) {
1122 state = *cached_state;
1123 if (state->start <= start && state->end > start &&
1124 extent_state_in_tree(state)) {
1125 node = &state->rb_node;
1131 * this search will find all the extents that end after
1134 node = tree_search_for_insert(tree, start, &p, &parent);
1136 prealloc = alloc_extent_state_atomic(prealloc);
1141 err = insert_state(tree, prealloc, start, end,
1142 &p, &parent, &bits, NULL);
1144 extent_io_tree_panic(tree, err);
1145 cache_state(prealloc, cached_state);
1149 state = rb_entry(node, struct extent_state, rb_node);
1151 last_start = state->start;
1152 last_end = state->end;
1155 * | ---- desired range ---- |
1158 * Just lock what we found and keep going
1160 if (state->start == start && state->end <= end) {
1161 set_state_bits(tree, state, &bits, NULL);
1162 cache_state(state, cached_state);
1163 state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
1164 if (last_end == (u64)-1)
1166 start = last_end + 1;
1167 if (start < end && state && state->start == start &&
1174 * | ---- desired range ---- |
1177 * | ------------- state -------------- |
1179 * We need to split the extent we found, and may flip bits on
1182 * If the extent we found extends past our
1183 * range, we just split and search again. It'll get split
1184 * again the next time though.
1186 * If the extent we found is inside our range, we set the
1187 * desired bit on it.
1189 if (state->start < start) {
1190 prealloc = alloc_extent_state_atomic(prealloc);
1195 err = split_state(tree, state, prealloc, start);
1197 extent_io_tree_panic(tree, err);
1201 if (state->end <= end) {
1202 set_state_bits(tree, state, &bits, NULL);
1203 cache_state(state, cached_state);
1204 state = clear_state_bit(tree, state, &clear_bits, 0,
1206 if (last_end == (u64)-1)
1208 start = last_end + 1;
1209 if (start < end && state && state->start == start &&
1216 * | ---- desired range ---- |
1217 * | state | or | state |
1219 * There's a hole, we need to insert something in it and
1220 * ignore the extent we found.
1222 if (state->start > start) {
1224 if (end < last_start)
1227 this_end = last_start - 1;
1229 prealloc = alloc_extent_state_atomic(prealloc);
1236 * Avoid to free 'prealloc' if it can be merged with
1239 err = insert_state(tree, prealloc, start, this_end,
1240 NULL, NULL, &bits, NULL);
1242 extent_io_tree_panic(tree, err);
1243 cache_state(prealloc, cached_state);
1245 start = this_end + 1;
1249 * | ---- desired range ---- |
1251 * We need to split the extent, and set the bit
1254 if (state->start <= end && state->end > end) {
1255 prealloc = alloc_extent_state_atomic(prealloc);
1261 err = split_state(tree, state, prealloc, end + 1);
1263 extent_io_tree_panic(tree, err);
1265 set_state_bits(tree, prealloc, &bits, NULL);
1266 cache_state(prealloc, cached_state);
1267 clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
1275 spin_unlock(&tree->lock);
1277 first_iteration = false;
1281 spin_unlock(&tree->lock);
1283 free_extent_state(prealloc);
1288 /* wrappers around set/clear extent bit */
1289 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1290 unsigned bits, struct extent_changeset *changeset)
1293 * We don't support EXTENT_LOCKED yet, as current changeset will
1294 * record any bits changed, so for EXTENT_LOCKED case, it will
1295 * either fail with -EEXIST or changeset will record the whole
1298 BUG_ON(bits & EXTENT_LOCKED);
1300 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
1304 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1305 unsigned bits, int wake, int delete,
1306 struct extent_state **cached, gfp_t mask)
1308 return __clear_extent_bit(tree, start, end, bits, wake, delete,
1309 cached, mask, NULL);
1312 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1313 unsigned bits, struct extent_changeset *changeset)
1316 * Don't support EXTENT_LOCKED case, same reason as
1317 * set_record_extent_bits().
1319 BUG_ON(bits & EXTENT_LOCKED);
1321 return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
1326 * either insert or lock state struct between start and end use mask to tell
1327 * us if waiting is desired.
1329 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1330 struct extent_state **cached_state)
1336 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
1337 EXTENT_LOCKED, &failed_start,
1338 cached_state, GFP_NOFS, NULL);
1339 if (err == -EEXIST) {
1340 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1341 start = failed_start;
1344 WARN_ON(start > end);
1349 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1354 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1355 &failed_start, NULL, GFP_NOFS, NULL);
1356 if (err == -EEXIST) {
1357 if (failed_start > start)
1358 clear_extent_bit(tree, start, failed_start - 1,
1359 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
1365 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1367 unsigned long index = start >> PAGE_SHIFT;
1368 unsigned long end_index = end >> PAGE_SHIFT;
1371 while (index <= end_index) {
1372 page = find_get_page(inode->i_mapping, index);
1373 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1374 clear_page_dirty_for_io(page);
1380 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1382 unsigned long index = start >> PAGE_SHIFT;
1383 unsigned long end_index = end >> PAGE_SHIFT;
1386 while (index <= end_index) {
1387 page = find_get_page(inode->i_mapping, index);
1388 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1389 __set_page_dirty_nobuffers(page);
1390 account_page_redirty(page);
1397 * helper function to set both pages and extents in the tree writeback
1399 static void set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1401 unsigned long index = start >> PAGE_SHIFT;
1402 unsigned long end_index = end >> PAGE_SHIFT;
1405 while (index <= end_index) {
1406 page = find_get_page(tree->mapping, index);
1407 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1408 set_page_writeback(page);
1414 /* find the first state struct with 'bits' set after 'start', and
1415 * return it. tree->lock must be held. NULL will returned if
1416 * nothing was found after 'start'
1418 static struct extent_state *
1419 find_first_extent_bit_state(struct extent_io_tree *tree,
1420 u64 start, unsigned bits)
1422 struct rb_node *node;
1423 struct extent_state *state;
1426 * this search will find all the extents that end after
1429 node = tree_search(tree, start);
1434 state = rb_entry(node, struct extent_state, rb_node);
1435 if (state->end >= start && (state->state & bits))
1438 node = rb_next(node);
1447 * find the first offset in the io tree with 'bits' set. zero is
1448 * returned if we find something, and *start_ret and *end_ret are
1449 * set to reflect the state struct that was found.
1451 * If nothing was found, 1 is returned. If found something, return 0.
1453 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1454 u64 *start_ret, u64 *end_ret, unsigned bits,
1455 struct extent_state **cached_state)
1457 struct extent_state *state;
1461 spin_lock(&tree->lock);
1462 if (cached_state && *cached_state) {
1463 state = *cached_state;
1464 if (state->end == start - 1 && extent_state_in_tree(state)) {
1465 n = rb_next(&state->rb_node);
1467 state = rb_entry(n, struct extent_state,
1469 if (state->state & bits)
1473 free_extent_state(*cached_state);
1474 *cached_state = NULL;
1477 free_extent_state(*cached_state);
1478 *cached_state = NULL;
1481 state = find_first_extent_bit_state(tree, start, bits);
1484 cache_state_if_flags(state, cached_state, 0);
1485 *start_ret = state->start;
1486 *end_ret = state->end;
1490 spin_unlock(&tree->lock);
1495 * find a contiguous range of bytes in the file marked as delalloc, not
1496 * more than 'max_bytes'. start and end are used to return the range,
1498 * 1 is returned if we find something, 0 if nothing was in the tree
1500 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1501 u64 *start, u64 *end, u64 max_bytes,
1502 struct extent_state **cached_state)
1504 struct rb_node *node;
1505 struct extent_state *state;
1506 u64 cur_start = *start;
1508 u64 total_bytes = 0;
1510 spin_lock(&tree->lock);
1513 * this search will find all the extents that end after
1516 node = tree_search(tree, cur_start);
1524 state = rb_entry(node, struct extent_state, rb_node);
1525 if (found && (state->start != cur_start ||
1526 (state->state & EXTENT_BOUNDARY))) {
1529 if (!(state->state & EXTENT_DELALLOC)) {
1535 *start = state->start;
1536 *cached_state = state;
1537 atomic_inc(&state->refs);
1541 cur_start = state->end + 1;
1542 node = rb_next(node);
1543 total_bytes += state->end - state->start + 1;
1544 if (total_bytes >= max_bytes)
1550 spin_unlock(&tree->lock);
1554 static noinline void __unlock_for_delalloc(struct inode *inode,
1555 struct page *locked_page,
1559 struct page *pages[16];
1560 unsigned long index = start >> PAGE_SHIFT;
1561 unsigned long end_index = end >> PAGE_SHIFT;
1562 unsigned long nr_pages = end_index - index + 1;
1565 if (index == locked_page->index && end_index == index)
1568 while (nr_pages > 0) {
1569 ret = find_get_pages_contig(inode->i_mapping, index,
1570 min_t(unsigned long, nr_pages,
1571 ARRAY_SIZE(pages)), pages);
1572 for (i = 0; i < ret; i++) {
1573 if (pages[i] != locked_page)
1574 unlock_page(pages[i]);
1583 static noinline int lock_delalloc_pages(struct inode *inode,
1584 struct page *locked_page,
1588 unsigned long index = delalloc_start >> PAGE_SHIFT;
1589 unsigned long start_index = index;
1590 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1591 unsigned long pages_locked = 0;
1592 struct page *pages[16];
1593 unsigned long nrpages;
1597 /* the caller is responsible for locking the start index */
1598 if (index == locked_page->index && index == end_index)
1601 /* skip the page at the start index */
1602 nrpages = end_index - index + 1;
1603 while (nrpages > 0) {
1604 ret = find_get_pages_contig(inode->i_mapping, index,
1605 min_t(unsigned long,
1606 nrpages, ARRAY_SIZE(pages)), pages);
1611 /* now we have an array of pages, lock them all */
1612 for (i = 0; i < ret; i++) {
1614 * the caller is taking responsibility for
1617 if (pages[i] != locked_page) {
1618 lock_page(pages[i]);
1619 if (!PageDirty(pages[i]) ||
1620 pages[i]->mapping != inode->i_mapping) {
1622 unlock_page(pages[i]);
1636 if (ret && pages_locked) {
1637 __unlock_for_delalloc(inode, locked_page,
1639 ((u64)(start_index + pages_locked - 1)) <<
1646 * find a contiguous range of bytes in the file marked as delalloc, not
1647 * more than 'max_bytes'. start and end are used to return the range,
1649 * 1 is returned if we find something, 0 if nothing was in the tree
1651 STATIC u64 find_lock_delalloc_range(struct inode *inode,
1652 struct extent_io_tree *tree,
1653 struct page *locked_page, u64 *start,
1654 u64 *end, u64 max_bytes)
1659 struct extent_state *cached_state = NULL;
1664 /* step one, find a bunch of delalloc bytes starting at start */
1665 delalloc_start = *start;
1667 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1668 max_bytes, &cached_state);
1669 if (!found || delalloc_end <= *start) {
1670 *start = delalloc_start;
1671 *end = delalloc_end;
1672 free_extent_state(cached_state);
1677 * start comes from the offset of locked_page. We have to lock
1678 * pages in order, so we can't process delalloc bytes before
1681 if (delalloc_start < *start)
1682 delalloc_start = *start;
1685 * make sure to limit the number of pages we try to lock down
1687 if (delalloc_end + 1 - delalloc_start > max_bytes)
1688 delalloc_end = delalloc_start + max_bytes - 1;
1690 /* step two, lock all the pages after the page that has start */
1691 ret = lock_delalloc_pages(inode, locked_page,
1692 delalloc_start, delalloc_end);
1693 if (ret == -EAGAIN) {
1694 /* some of the pages are gone, lets avoid looping by
1695 * shortening the size of the delalloc range we're searching
1697 free_extent_state(cached_state);
1698 cached_state = NULL;
1700 max_bytes = PAGE_SIZE;
1708 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1710 /* step three, lock the state bits for the whole range */
1711 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1713 /* then test to make sure it is all still delalloc */
1714 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1715 EXTENT_DELALLOC, 1, cached_state);
1717 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1718 &cached_state, GFP_NOFS);
1719 __unlock_for_delalloc(inode, locked_page,
1720 delalloc_start, delalloc_end);
1724 free_extent_state(cached_state);
1725 *start = delalloc_start;
1726 *end = delalloc_end;
1731 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1732 struct page *locked_page,
1733 unsigned clear_bits,
1734 unsigned long page_ops)
1736 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
1738 struct page *pages[16];
1739 unsigned long index = start >> PAGE_SHIFT;
1740 unsigned long end_index = end >> PAGE_SHIFT;
1741 unsigned long nr_pages = end_index - index + 1;
1744 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1748 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1749 mapping_set_error(inode->i_mapping, -EIO);
1751 while (nr_pages > 0) {
1752 ret = find_get_pages_contig(inode->i_mapping, index,
1753 min_t(unsigned long,
1754 nr_pages, ARRAY_SIZE(pages)), pages);
1755 for (i = 0; i < ret; i++) {
1757 if (page_ops & PAGE_SET_PRIVATE2)
1758 SetPagePrivate2(pages[i]);
1760 if (pages[i] == locked_page) {
1764 if (page_ops & PAGE_CLEAR_DIRTY)
1765 clear_page_dirty_for_io(pages[i]);
1766 if (page_ops & PAGE_SET_WRITEBACK)
1767 set_page_writeback(pages[i]);
1768 if (page_ops & PAGE_SET_ERROR)
1769 SetPageError(pages[i]);
1770 if (page_ops & PAGE_END_WRITEBACK)
1771 end_page_writeback(pages[i]);
1772 if (page_ops & PAGE_UNLOCK)
1773 unlock_page(pages[i]);
1783 * count the number of bytes in the tree that have a given bit(s)
1784 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1785 * cached. The total number found is returned.
1787 u64 count_range_bits(struct extent_io_tree *tree,
1788 u64 *start, u64 search_end, u64 max_bytes,
1789 unsigned bits, int contig)
1791 struct rb_node *node;
1792 struct extent_state *state;
1793 u64 cur_start = *start;
1794 u64 total_bytes = 0;
1798 if (WARN_ON(search_end <= cur_start))
1801 spin_lock(&tree->lock);
1802 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1803 total_bytes = tree->dirty_bytes;
1807 * this search will find all the extents that end after
1810 node = tree_search(tree, cur_start);
1815 state = rb_entry(node, struct extent_state, rb_node);
1816 if (state->start > search_end)
1818 if (contig && found && state->start > last + 1)
1820 if (state->end >= cur_start && (state->state & bits) == bits) {
1821 total_bytes += min(search_end, state->end) + 1 -
1822 max(cur_start, state->start);
1823 if (total_bytes >= max_bytes)
1826 *start = max(cur_start, state->start);
1830 } else if (contig && found) {
1833 node = rb_next(node);
1838 spin_unlock(&tree->lock);
1843 * set the private field for a given byte offset in the tree. If there isn't
1844 * an extent_state there already, this does nothing.
1846 static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start,
1847 struct io_failure_record *failrec)
1849 struct rb_node *node;
1850 struct extent_state *state;
1853 spin_lock(&tree->lock);
1855 * this search will find all the extents that end after
1858 node = tree_search(tree, start);
1863 state = rb_entry(node, struct extent_state, rb_node);
1864 if (state->start != start) {
1868 state->failrec = failrec;
1870 spin_unlock(&tree->lock);
1874 static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start,
1875 struct io_failure_record **failrec)
1877 struct rb_node *node;
1878 struct extent_state *state;
1881 spin_lock(&tree->lock);
1883 * this search will find all the extents that end after
1886 node = tree_search(tree, start);
1891 state = rb_entry(node, struct extent_state, rb_node);
1892 if (state->start != start) {
1896 *failrec = state->failrec;
1898 spin_unlock(&tree->lock);
1903 * searches a range in the state tree for a given mask.
1904 * If 'filled' == 1, this returns 1 only if every extent in the tree
1905 * has the bits set. Otherwise, 1 is returned if any bit in the
1906 * range is found set.
1908 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1909 unsigned bits, int filled, struct extent_state *cached)
1911 struct extent_state *state = NULL;
1912 struct rb_node *node;
1915 spin_lock(&tree->lock);
1916 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
1917 cached->end > start)
1918 node = &cached->rb_node;
1920 node = tree_search(tree, start);
1921 while (node && start <= end) {
1922 state = rb_entry(node, struct extent_state, rb_node);
1924 if (filled && state->start > start) {
1929 if (state->start > end)
1932 if (state->state & bits) {
1936 } else if (filled) {
1941 if (state->end == (u64)-1)
1944 start = state->end + 1;
1947 node = rb_next(node);
1954 spin_unlock(&tree->lock);
1959 * helper function to set a given page up to date if all the
1960 * extents in the tree for that page are up to date
1962 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1964 u64 start = page_offset(page);
1965 u64 end = start + PAGE_SIZE - 1;
1966 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1967 SetPageUptodate(page);
1970 int free_io_failure(struct inode *inode, struct io_failure_record *rec)
1974 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1976 set_state_failrec(failure_tree, rec->start, NULL);
1977 ret = clear_extent_bits(failure_tree, rec->start,
1978 rec->start + rec->len - 1,
1979 EXTENT_LOCKED | EXTENT_DIRTY);
1983 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1984 rec->start + rec->len - 1,
1994 * this bypasses the standard btrfs submit functions deliberately, as
1995 * the standard behavior is to write all copies in a raid setup. here we only
1996 * want to write the one bad copy. so we do the mapping for ourselves and issue
1997 * submit_bio directly.
1998 * to avoid any synchronization issues, wait for the data after writing, which
1999 * actually prevents the read that triggered the error from finishing.
2000 * currently, there can be no more than two copies of every data bit. thus,
2001 * exactly one rewrite is required.
2003 int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical,
2004 struct page *page, unsigned int pg_offset, int mirror_num)
2006 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2008 struct btrfs_device *dev;
2011 struct btrfs_bio *bbio = NULL;
2012 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
2015 ASSERT(!(fs_info->sb->s_flags & MS_RDONLY));
2016 BUG_ON(!mirror_num);
2018 /* we can't repair anything in raid56 yet */
2019 if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num))
2022 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2025 bio->bi_iter.bi_size = 0;
2026 map_length = length;
2029 * Avoid races with device replace and make sure our bbio has devices
2030 * associated to its stripes that don't go away while we are doing the
2031 * read repair operation.
2033 btrfs_bio_counter_inc_blocked(fs_info);
2034 ret = btrfs_map_block(fs_info, WRITE, logical,
2035 &map_length, &bbio, mirror_num);
2037 btrfs_bio_counter_dec(fs_info);
2041 BUG_ON(mirror_num != bbio->mirror_num);
2042 sector = bbio->stripes[mirror_num-1].physical >> 9;
2043 bio->bi_iter.bi_sector = sector;
2044 dev = bbio->stripes[mirror_num-1].dev;
2045 btrfs_put_bbio(bbio);
2046 if (!dev || !dev->bdev || !dev->writeable) {
2047 btrfs_bio_counter_dec(fs_info);
2051 bio->bi_bdev = dev->bdev;
2052 bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_SYNC);
2053 bio_add_page(bio, page, length, pg_offset);
2055 if (btrfsic_submit_bio_wait(bio)) {
2056 /* try to remap that extent elsewhere? */
2057 btrfs_bio_counter_dec(fs_info);
2059 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2063 btrfs_info_rl_in_rcu(fs_info,
2064 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2065 btrfs_ino(inode), start,
2066 rcu_str_deref(dev->name), sector);
2067 btrfs_bio_counter_dec(fs_info);
2072 int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
2075 u64 start = eb->start;
2076 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
2079 if (root->fs_info->sb->s_flags & MS_RDONLY)
2082 for (i = 0; i < num_pages; i++) {
2083 struct page *p = eb->pages[i];
2085 ret = repair_io_failure(root->fs_info->btree_inode, start,
2086 PAGE_SIZE, start, p,
2087 start - page_offset(p), mirror_num);
2097 * each time an IO finishes, we do a fast check in the IO failure tree
2098 * to see if we need to process or clean up an io_failure_record
2100 int clean_io_failure(struct inode *inode, u64 start, struct page *page,
2101 unsigned int pg_offset)
2104 struct io_failure_record *failrec;
2105 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2106 struct extent_state *state;
2111 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
2112 (u64)-1, 1, EXTENT_DIRTY, 0);
2116 ret = get_state_failrec(&BTRFS_I(inode)->io_failure_tree, start,
2121 BUG_ON(!failrec->this_mirror);
2123 if (failrec->in_validation) {
2124 /* there was no real error, just free the record */
2125 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2129 if (fs_info->sb->s_flags & MS_RDONLY)
2132 spin_lock(&BTRFS_I(inode)->io_tree.lock);
2133 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
2136 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
2138 if (state && state->start <= failrec->start &&
2139 state->end >= failrec->start + failrec->len - 1) {
2140 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2142 if (num_copies > 1) {
2143 repair_io_failure(inode, start, failrec->len,
2144 failrec->logical, page,
2145 pg_offset, failrec->failed_mirror);
2150 free_io_failure(inode, failrec);
2156 * Can be called when
2157 * - hold extent lock
2158 * - under ordered extent
2159 * - the inode is freeing
2161 void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end)
2163 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2164 struct io_failure_record *failrec;
2165 struct extent_state *state, *next;
2167 if (RB_EMPTY_ROOT(&failure_tree->state))
2170 spin_lock(&failure_tree->lock);
2171 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2173 if (state->start > end)
2176 ASSERT(state->end <= end);
2178 next = next_state(state);
2180 failrec = state->failrec;
2181 free_extent_state(state);
2186 spin_unlock(&failure_tree->lock);
2189 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2190 struct io_failure_record **failrec_ret)
2192 struct io_failure_record *failrec;
2193 struct extent_map *em;
2194 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2195 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2196 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2200 ret = get_state_failrec(failure_tree, start, &failrec);
2202 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2206 failrec->start = start;
2207 failrec->len = end - start + 1;
2208 failrec->this_mirror = 0;
2209 failrec->bio_flags = 0;
2210 failrec->in_validation = 0;
2212 read_lock(&em_tree->lock);
2213 em = lookup_extent_mapping(em_tree, start, failrec->len);
2215 read_unlock(&em_tree->lock);
2220 if (em->start > start || em->start + em->len <= start) {
2221 free_extent_map(em);
2224 read_unlock(&em_tree->lock);
2230 logical = start - em->start;
2231 logical = em->block_start + logical;
2232 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2233 logical = em->block_start;
2234 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2235 extent_set_compress_type(&failrec->bio_flags,
2239 pr_debug("Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu\n",
2240 logical, start, failrec->len);
2242 failrec->logical = logical;
2243 free_extent_map(em);
2245 /* set the bits in the private failure tree */
2246 ret = set_extent_bits(failure_tree, start, end,
2247 EXTENT_LOCKED | EXTENT_DIRTY);
2249 ret = set_state_failrec(failure_tree, start, failrec);
2250 /* set the bits in the inode's tree */
2252 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2258 pr_debug("Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d\n",
2259 failrec->logical, failrec->start, failrec->len,
2260 failrec->in_validation);
2262 * when data can be on disk more than twice, add to failrec here
2263 * (e.g. with a list for failed_mirror) to make
2264 * clean_io_failure() clean all those errors at once.
2268 *failrec_ret = failrec;
2273 int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
2274 struct io_failure_record *failrec, int failed_mirror)
2278 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
2279 failrec->logical, failrec->len);
2280 if (num_copies == 1) {
2282 * we only have a single copy of the data, so don't bother with
2283 * all the retry and error correction code that follows. no
2284 * matter what the error is, it is very likely to persist.
2286 pr_debug("Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
2287 num_copies, failrec->this_mirror, failed_mirror);
2292 * there are two premises:
2293 * a) deliver good data to the caller
2294 * b) correct the bad sectors on disk
2296 if (failed_bio->bi_vcnt > 1) {
2298 * to fulfill b), we need to know the exact failing sectors, as
2299 * we don't want to rewrite any more than the failed ones. thus,
2300 * we need separate read requests for the failed bio
2302 * if the following BUG_ON triggers, our validation request got
2303 * merged. we need separate requests for our algorithm to work.
2305 BUG_ON(failrec->in_validation);
2306 failrec->in_validation = 1;
2307 failrec->this_mirror = failed_mirror;
2310 * we're ready to fulfill a) and b) alongside. get a good copy
2311 * of the failed sector and if we succeed, we have setup
2312 * everything for repair_io_failure to do the rest for us.
2314 if (failrec->in_validation) {
2315 BUG_ON(failrec->this_mirror != failed_mirror);
2316 failrec->in_validation = 0;
2317 failrec->this_mirror = 0;
2319 failrec->failed_mirror = failed_mirror;
2320 failrec->this_mirror++;
2321 if (failrec->this_mirror == failed_mirror)
2322 failrec->this_mirror++;
2325 if (failrec->this_mirror > num_copies) {
2326 pr_debug("Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
2327 num_copies, failrec->this_mirror, failed_mirror);
2335 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
2336 struct io_failure_record *failrec,
2337 struct page *page, int pg_offset, int icsum,
2338 bio_end_io_t *endio_func, void *data)
2341 struct btrfs_io_bio *btrfs_failed_bio;
2342 struct btrfs_io_bio *btrfs_bio;
2344 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2348 bio->bi_end_io = endio_func;
2349 bio->bi_iter.bi_sector = failrec->logical >> 9;
2350 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
2351 bio->bi_iter.bi_size = 0;
2352 bio->bi_private = data;
2354 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2355 if (btrfs_failed_bio->csum) {
2356 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2357 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2359 btrfs_bio = btrfs_io_bio(bio);
2360 btrfs_bio->csum = btrfs_bio->csum_inline;
2362 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
2366 bio_add_page(bio, page, failrec->len, pg_offset);
2372 * this is a generic handler for readpage errors (default
2373 * readpage_io_failed_hook). if other copies exist, read those and write back
2374 * good data to the failed position. does not investigate in remapping the
2375 * failed extent elsewhere, hoping the device will be smart enough to do this as
2379 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2380 struct page *page, u64 start, u64 end,
2383 struct io_failure_record *failrec;
2384 struct inode *inode = page->mapping->host;
2385 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2390 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2392 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2396 ret = btrfs_check_repairable(inode, failed_bio, failrec, failed_mirror);
2398 free_io_failure(inode, failrec);
2402 if (failed_bio->bi_vcnt > 1)
2403 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
2405 read_mode = READ_SYNC;
2407 phy_offset >>= inode->i_sb->s_blocksize_bits;
2408 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
2409 start - page_offset(page),
2410 (int)phy_offset, failed_bio->bi_end_io,
2413 free_io_failure(inode, failrec);
2416 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
2418 pr_debug("Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d\n",
2419 read_mode, failrec->this_mirror, failrec->in_validation);
2421 ret = tree->ops->submit_bio_hook(inode, bio, failrec->this_mirror,
2422 failrec->bio_flags, 0);
2424 free_io_failure(inode, failrec);
2431 /* lots and lots of room for performance fixes in the end_bio funcs */
2433 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2435 int uptodate = (err == 0);
2436 struct extent_io_tree *tree;
2439 tree = &BTRFS_I(page->mapping->host)->io_tree;
2441 if (tree->ops && tree->ops->writepage_end_io_hook) {
2442 ret = tree->ops->writepage_end_io_hook(page, start,
2443 end, NULL, uptodate);
2449 ClearPageUptodate(page);
2451 ret = ret < 0 ? ret : -EIO;
2452 mapping_set_error(page->mapping, ret);
2457 * after a writepage IO is done, we need to:
2458 * clear the uptodate bits on error
2459 * clear the writeback bits in the extent tree for this IO
2460 * end_page_writeback if the page has no more pending IO
2462 * Scheduling is not allowed, so the extent state tree is expected
2463 * to have one and only one object corresponding to this IO.
2465 static void end_bio_extent_writepage(struct bio *bio)
2467 struct bio_vec *bvec;
2472 bio_for_each_segment_all(bvec, bio, i) {
2473 struct page *page = bvec->bv_page;
2475 /* We always issue full-page reads, but if some block
2476 * in a page fails to read, blk_update_request() will
2477 * advance bv_offset and adjust bv_len to compensate.
2478 * Print a warning for nonzero offsets, and an error
2479 * if they don't add up to a full page. */
2480 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2481 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2482 btrfs_err(BTRFS_I(page->mapping->host)->root->fs_info,
2483 "partial page write in btrfs with offset %u and length %u",
2484 bvec->bv_offset, bvec->bv_len);
2486 btrfs_info(BTRFS_I(page->mapping->host)->root->fs_info,
2487 "incomplete page write in btrfs with offset %u and "
2489 bvec->bv_offset, bvec->bv_len);
2492 start = page_offset(page);
2493 end = start + bvec->bv_offset + bvec->bv_len - 1;
2495 end_extent_writepage(page, bio->bi_error, start, end);
2496 end_page_writeback(page);
2503 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2506 struct extent_state *cached = NULL;
2507 u64 end = start + len - 1;
2509 if (uptodate && tree->track_uptodate)
2510 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2511 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2515 * after a readpage IO is done, we need to:
2516 * clear the uptodate bits on error
2517 * set the uptodate bits if things worked
2518 * set the page up to date if all extents in the tree are uptodate
2519 * clear the lock bit in the extent tree
2520 * unlock the page if there are no other extents locked for it
2522 * Scheduling is not allowed, so the extent state tree is expected
2523 * to have one and only one object corresponding to this IO.
2525 static void end_bio_extent_readpage(struct bio *bio)
2527 struct bio_vec *bvec;
2528 int uptodate = !bio->bi_error;
2529 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2530 struct extent_io_tree *tree;
2535 u64 extent_start = 0;
2541 bio_for_each_segment_all(bvec, bio, i) {
2542 struct page *page = bvec->bv_page;
2543 struct inode *inode = page->mapping->host;
2545 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2546 "mirror=%u\n", (u64)bio->bi_iter.bi_sector,
2547 bio->bi_error, io_bio->mirror_num);
2548 tree = &BTRFS_I(inode)->io_tree;
2550 /* We always issue full-page reads, but if some block
2551 * in a page fails to read, blk_update_request() will
2552 * advance bv_offset and adjust bv_len to compensate.
2553 * Print a warning for nonzero offsets, and an error
2554 * if they don't add up to a full page. */
2555 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2556 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2557 btrfs_err(BTRFS_I(page->mapping->host)->root->fs_info,
2558 "partial page read in btrfs with offset %u and length %u",
2559 bvec->bv_offset, bvec->bv_len);
2561 btrfs_info(BTRFS_I(page->mapping->host)->root->fs_info,
2562 "incomplete page read in btrfs with offset %u and "
2564 bvec->bv_offset, bvec->bv_len);
2567 start = page_offset(page);
2568 end = start + bvec->bv_offset + bvec->bv_len - 1;
2571 mirror = io_bio->mirror_num;
2572 if (likely(uptodate && tree->ops &&
2573 tree->ops->readpage_end_io_hook)) {
2574 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2580 clean_io_failure(inode, start, page, 0);
2583 if (likely(uptodate))
2586 if (tree->ops && tree->ops->readpage_io_failed_hook) {
2587 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2588 if (!ret && !bio->bi_error)
2592 * The generic bio_readpage_error handles errors the
2593 * following way: If possible, new read requests are
2594 * created and submitted and will end up in
2595 * end_bio_extent_readpage as well (if we're lucky, not
2596 * in the !uptodate case). In that case it returns 0 and
2597 * we just go on with the next page in our bio. If it
2598 * can't handle the error it will return -EIO and we
2599 * remain responsible for that page.
2601 ret = bio_readpage_error(bio, offset, page, start, end,
2604 uptodate = !bio->bi_error;
2610 if (likely(uptodate)) {
2611 loff_t i_size = i_size_read(inode);
2612 pgoff_t end_index = i_size >> PAGE_SHIFT;
2615 /* Zero out the end if this page straddles i_size */
2616 off = i_size & (PAGE_SIZE-1);
2617 if (page->index == end_index && off)
2618 zero_user_segment(page, off, PAGE_SIZE);
2619 SetPageUptodate(page);
2621 ClearPageUptodate(page);
2627 if (unlikely(!uptodate)) {
2629 endio_readpage_release_extent(tree,
2635 endio_readpage_release_extent(tree, start,
2636 end - start + 1, 0);
2637 } else if (!extent_len) {
2638 extent_start = start;
2639 extent_len = end + 1 - start;
2640 } else if (extent_start + extent_len == start) {
2641 extent_len += end + 1 - start;
2643 endio_readpage_release_extent(tree, extent_start,
2644 extent_len, uptodate);
2645 extent_start = start;
2646 extent_len = end + 1 - start;
2651 endio_readpage_release_extent(tree, extent_start, extent_len,
2654 io_bio->end_io(io_bio, bio->bi_error);
2659 * this allocates from the btrfs_bioset. We're returning a bio right now
2660 * but you can call btrfs_io_bio for the appropriate container_of magic
2663 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2666 struct btrfs_io_bio *btrfs_bio;
2669 bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset);
2671 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2672 while (!bio && (nr_vecs /= 2)) {
2673 bio = bio_alloc_bioset(gfp_flags,
2674 nr_vecs, btrfs_bioset);
2679 bio->bi_bdev = bdev;
2680 bio->bi_iter.bi_sector = first_sector;
2681 btrfs_bio = btrfs_io_bio(bio);
2682 btrfs_bio->csum = NULL;
2683 btrfs_bio->csum_allocated = NULL;
2684 btrfs_bio->end_io = NULL;
2689 struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
2691 struct btrfs_io_bio *btrfs_bio;
2694 new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset);
2696 btrfs_bio = btrfs_io_bio(new);
2697 btrfs_bio->csum = NULL;
2698 btrfs_bio->csum_allocated = NULL;
2699 btrfs_bio->end_io = NULL;
2704 /* this also allocates from the btrfs_bioset */
2705 struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
2707 struct btrfs_io_bio *btrfs_bio;
2710 bio = bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
2712 btrfs_bio = btrfs_io_bio(bio);
2713 btrfs_bio->csum = NULL;
2714 btrfs_bio->csum_allocated = NULL;
2715 btrfs_bio->end_io = NULL;
2721 static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
2722 unsigned long bio_flags)
2725 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2726 struct page *page = bvec->bv_page;
2727 struct extent_io_tree *tree = bio->bi_private;
2730 start = page_offset(page) + bvec->bv_offset;
2732 bio->bi_private = NULL;
2735 if (tree->ops && tree->ops->submit_bio_hook)
2736 ret = tree->ops->submit_bio_hook(page->mapping->host, bio,
2737 mirror_num, bio_flags, start);
2739 btrfsic_submit_bio(bio);
2745 static int merge_bio(struct extent_io_tree *tree, struct page *page,
2746 unsigned long offset, size_t size, struct bio *bio,
2747 unsigned long bio_flags)
2750 if (tree->ops && tree->ops->merge_bio_hook)
2751 ret = tree->ops->merge_bio_hook(page, offset, size, bio,
2757 static int submit_extent_page(int op, int op_flags, struct extent_io_tree *tree,
2758 struct writeback_control *wbc,
2759 struct page *page, sector_t sector,
2760 size_t size, unsigned long offset,
2761 struct block_device *bdev,
2762 struct bio **bio_ret,
2763 unsigned long max_pages,
2764 bio_end_io_t end_io_func,
2766 unsigned long prev_bio_flags,
2767 unsigned long bio_flags,
2768 bool force_bio_submit)
2773 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2774 size_t page_size = min_t(size_t, size, PAGE_SIZE);
2776 if (bio_ret && *bio_ret) {
2779 contig = bio->bi_iter.bi_sector == sector;
2781 contig = bio_end_sector(bio) == sector;
2783 if (prev_bio_flags != bio_flags || !contig ||
2785 merge_bio(tree, page, offset, page_size, bio, bio_flags) ||
2786 bio_add_page(bio, page, page_size, offset) < page_size) {
2787 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
2795 wbc_account_io(wbc, page, page_size);
2800 bio = btrfs_bio_alloc(bdev, sector, BIO_MAX_PAGES,
2801 GFP_NOFS | __GFP_HIGH);
2805 bio_add_page(bio, page, page_size, offset);
2806 bio->bi_end_io = end_io_func;
2807 bio->bi_private = tree;
2808 bio_set_op_attrs(bio, op, op_flags);
2810 wbc_init_bio(wbc, bio);
2811 wbc_account_io(wbc, page, page_size);
2817 ret = submit_one_bio(bio, mirror_num, bio_flags);
2822 static void attach_extent_buffer_page(struct extent_buffer *eb,
2825 if (!PagePrivate(page)) {
2826 SetPagePrivate(page);
2828 set_page_private(page, (unsigned long)eb);
2830 WARN_ON(page->private != (unsigned long)eb);
2834 void set_page_extent_mapped(struct page *page)
2836 if (!PagePrivate(page)) {
2837 SetPagePrivate(page);
2839 set_page_private(page, EXTENT_PAGE_PRIVATE);
2843 static struct extent_map *
2844 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
2845 u64 start, u64 len, get_extent_t *get_extent,
2846 struct extent_map **em_cached)
2848 struct extent_map *em;
2850 if (em_cached && *em_cached) {
2852 if (extent_map_in_tree(em) && start >= em->start &&
2853 start < extent_map_end(em)) {
2854 atomic_inc(&em->refs);
2858 free_extent_map(em);
2862 em = get_extent(inode, page, pg_offset, start, len, 0);
2863 if (em_cached && !IS_ERR_OR_NULL(em)) {
2865 atomic_inc(&em->refs);
2871 * basic readpage implementation. Locked extent state structs are inserted
2872 * into the tree that are removed when the IO is done (by the end_io
2874 * XXX JDM: This needs looking at to ensure proper page locking
2875 * return 0 on success, otherwise return error
2877 static int __do_readpage(struct extent_io_tree *tree,
2879 get_extent_t *get_extent,
2880 struct extent_map **em_cached,
2881 struct bio **bio, int mirror_num,
2882 unsigned long *bio_flags, int read_flags,
2885 struct inode *inode = page->mapping->host;
2886 u64 start = page_offset(page);
2887 u64 page_end = start + PAGE_SIZE - 1;
2891 u64 last_byte = i_size_read(inode);
2895 struct extent_map *em;
2896 struct block_device *bdev;
2899 size_t pg_offset = 0;
2901 size_t disk_io_size;
2902 size_t blocksize = inode->i_sb->s_blocksize;
2903 unsigned long this_bio_flag = 0;
2905 set_page_extent_mapped(page);
2908 if (!PageUptodate(page)) {
2909 if (cleancache_get_page(page) == 0) {
2910 BUG_ON(blocksize != PAGE_SIZE);
2911 unlock_extent(tree, start, end);
2916 if (page->index == last_byte >> PAGE_SHIFT) {
2918 size_t zero_offset = last_byte & (PAGE_SIZE - 1);
2921 iosize = PAGE_SIZE - zero_offset;
2922 userpage = kmap_atomic(page);
2923 memset(userpage + zero_offset, 0, iosize);
2924 flush_dcache_page(page);
2925 kunmap_atomic(userpage);
2928 while (cur <= end) {
2929 unsigned long pnr = (last_byte >> PAGE_SHIFT) + 1;
2930 bool force_bio_submit = false;
2932 if (cur >= last_byte) {
2934 struct extent_state *cached = NULL;
2936 iosize = PAGE_SIZE - pg_offset;
2937 userpage = kmap_atomic(page);
2938 memset(userpage + pg_offset, 0, iosize);
2939 flush_dcache_page(page);
2940 kunmap_atomic(userpage);
2941 set_extent_uptodate(tree, cur, cur + iosize - 1,
2943 unlock_extent_cached(tree, cur,
2948 em = __get_extent_map(inode, page, pg_offset, cur,
2949 end - cur + 1, get_extent, em_cached);
2950 if (IS_ERR_OR_NULL(em)) {
2952 unlock_extent(tree, cur, end);
2955 extent_offset = cur - em->start;
2956 BUG_ON(extent_map_end(em) <= cur);
2959 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2960 this_bio_flag |= EXTENT_BIO_COMPRESSED;
2961 extent_set_compress_type(&this_bio_flag,
2965 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2966 cur_end = min(extent_map_end(em) - 1, end);
2967 iosize = ALIGN(iosize, blocksize);
2968 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2969 disk_io_size = em->block_len;
2970 sector = em->block_start >> 9;
2972 sector = (em->block_start + extent_offset) >> 9;
2973 disk_io_size = iosize;
2976 block_start = em->block_start;
2977 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2978 block_start = EXTENT_MAP_HOLE;
2981 * If we have a file range that points to a compressed extent
2982 * and it's followed by a consecutive file range that points to
2983 * to the same compressed extent (possibly with a different
2984 * offset and/or length, so it either points to the whole extent
2985 * or only part of it), we must make sure we do not submit a
2986 * single bio to populate the pages for the 2 ranges because
2987 * this makes the compressed extent read zero out the pages
2988 * belonging to the 2nd range. Imagine the following scenario:
2991 * [0 - 8K] [8K - 24K]
2994 * points to extent X, points to extent X,
2995 * offset 4K, length of 8K offset 0, length 16K
2997 * [extent X, compressed length = 4K uncompressed length = 16K]
2999 * If the bio to read the compressed extent covers both ranges,
3000 * it will decompress extent X into the pages belonging to the
3001 * first range and then it will stop, zeroing out the remaining
3002 * pages that belong to the other range that points to extent X.
3003 * So here we make sure we submit 2 bios, one for the first
3004 * range and another one for the third range. Both will target
3005 * the same physical extent from disk, but we can't currently
3006 * make the compressed bio endio callback populate the pages
3007 * for both ranges because each compressed bio is tightly
3008 * coupled with a single extent map, and each range can have
3009 * an extent map with a different offset value relative to the
3010 * uncompressed data of our extent and different lengths. This
3011 * is a corner case so we prioritize correctness over
3012 * non-optimal behavior (submitting 2 bios for the same extent).
3014 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3015 prev_em_start && *prev_em_start != (u64)-1 &&
3016 *prev_em_start != em->orig_start)
3017 force_bio_submit = true;
3020 *prev_em_start = em->orig_start;
3022 free_extent_map(em);
3025 /* we've found a hole, just zero and go on */
3026 if (block_start == EXTENT_MAP_HOLE) {
3028 struct extent_state *cached = NULL;
3030 userpage = kmap_atomic(page);
3031 memset(userpage + pg_offset, 0, iosize);
3032 flush_dcache_page(page);
3033 kunmap_atomic(userpage);
3035 set_extent_uptodate(tree, cur, cur + iosize - 1,
3037 unlock_extent_cached(tree, cur,
3041 pg_offset += iosize;
3044 /* the get_extent function already copied into the page */
3045 if (test_range_bit(tree, cur, cur_end,
3046 EXTENT_UPTODATE, 1, NULL)) {
3047 check_page_uptodate(tree, page);
3048 unlock_extent(tree, cur, cur + iosize - 1);
3050 pg_offset += iosize;
3053 /* we have an inline extent but it didn't get marked up
3054 * to date. Error out
3056 if (block_start == EXTENT_MAP_INLINE) {
3058 unlock_extent(tree, cur, cur + iosize - 1);
3060 pg_offset += iosize;
3065 ret = submit_extent_page(REQ_OP_READ, read_flags, tree, NULL,
3066 page, sector, disk_io_size, pg_offset,
3068 end_bio_extent_readpage, mirror_num,
3074 *bio_flags = this_bio_flag;
3077 unlock_extent(tree, cur, cur + iosize - 1);
3081 pg_offset += iosize;
3085 if (!PageError(page))
3086 SetPageUptodate(page);
3092 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
3093 struct page *pages[], int nr_pages,
3095 get_extent_t *get_extent,
3096 struct extent_map **em_cached,
3097 struct bio **bio, int mirror_num,
3098 unsigned long *bio_flags,
3101 struct inode *inode;
3102 struct btrfs_ordered_extent *ordered;
3105 inode = pages[0]->mapping->host;
3107 lock_extent(tree, start, end);
3108 ordered = btrfs_lookup_ordered_range(inode, start,
3112 unlock_extent(tree, start, end);
3113 btrfs_start_ordered_extent(inode, ordered, 1);
3114 btrfs_put_ordered_extent(ordered);
3117 for (index = 0; index < nr_pages; index++) {
3118 __do_readpage(tree, pages[index], get_extent, em_cached, bio,
3119 mirror_num, bio_flags, 0, prev_em_start);
3120 put_page(pages[index]);
3124 static void __extent_readpages(struct extent_io_tree *tree,
3125 struct page *pages[],
3126 int nr_pages, get_extent_t *get_extent,
3127 struct extent_map **em_cached,
3128 struct bio **bio, int mirror_num,
3129 unsigned long *bio_flags,
3136 int first_index = 0;
3138 for (index = 0; index < nr_pages; index++) {
3139 page_start = page_offset(pages[index]);
3142 end = start + PAGE_SIZE - 1;
3143 first_index = index;
3144 } else if (end + 1 == page_start) {
3147 __do_contiguous_readpages(tree, &pages[first_index],
3148 index - first_index, start,
3149 end, get_extent, em_cached,
3150 bio, mirror_num, bio_flags,
3153 end = start + PAGE_SIZE - 1;
3154 first_index = index;
3159 __do_contiguous_readpages(tree, &pages[first_index],
3160 index - first_index, start,
3161 end, get_extent, em_cached, bio,
3162 mirror_num, bio_flags,
3166 static int __extent_read_full_page(struct extent_io_tree *tree,
3168 get_extent_t *get_extent,
3169 struct bio **bio, int mirror_num,
3170 unsigned long *bio_flags, int read_flags)
3172 struct inode *inode = page->mapping->host;
3173 struct btrfs_ordered_extent *ordered;
3174 u64 start = page_offset(page);
3175 u64 end = start + PAGE_SIZE - 1;
3179 lock_extent(tree, start, end);
3180 ordered = btrfs_lookup_ordered_range(inode, start,
3184 unlock_extent(tree, start, end);
3185 btrfs_start_ordered_extent(inode, ordered, 1);
3186 btrfs_put_ordered_extent(ordered);
3189 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3190 bio_flags, read_flags, NULL);
3194 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3195 get_extent_t *get_extent, int mirror_num)
3197 struct bio *bio = NULL;
3198 unsigned long bio_flags = 0;
3201 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3204 ret = submit_one_bio(bio, mirror_num, bio_flags);
3208 static void update_nr_written(struct page *page, struct writeback_control *wbc,
3209 unsigned long nr_written)
3211 wbc->nr_to_write -= nr_written;
3215 * helper for __extent_writepage, doing all of the delayed allocation setup.
3217 * This returns 1 if our fill_delalloc function did all the work required
3218 * to write the page (copy into inline extent). In this case the IO has
3219 * been started and the page is already unlocked.
3221 * This returns 0 if all went well (page still locked)
3222 * This returns < 0 if there were errors (page still locked)
3224 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3225 struct page *page, struct writeback_control *wbc,
3226 struct extent_page_data *epd,
3228 unsigned long *nr_written)
3230 struct extent_io_tree *tree = epd->tree;
3231 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3233 u64 delalloc_to_write = 0;
3234 u64 delalloc_end = 0;
3236 int page_started = 0;
3238 if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
3241 while (delalloc_end < page_end) {
3242 nr_delalloc = find_lock_delalloc_range(inode, tree,
3246 BTRFS_MAX_EXTENT_SIZE);
3247 if (nr_delalloc == 0) {
3248 delalloc_start = delalloc_end + 1;
3251 ret = tree->ops->fill_delalloc(inode, page,
3256 /* File system has been set read-only */
3259 /* fill_delalloc should be return < 0 for error
3260 * but just in case, we use > 0 here meaning the
3261 * IO is started, so we don't want to return > 0
3262 * unless things are going well.
3264 ret = ret < 0 ? ret : -EIO;
3268 * delalloc_end is already one less than the total length, so
3269 * we don't subtract one from PAGE_SIZE
3271 delalloc_to_write += (delalloc_end - delalloc_start +
3272 PAGE_SIZE) >> PAGE_SHIFT;
3273 delalloc_start = delalloc_end + 1;
3275 if (wbc->nr_to_write < delalloc_to_write) {
3278 if (delalloc_to_write < thresh * 2)
3279 thresh = delalloc_to_write;
3280 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3284 /* did the fill delalloc function already unlock and start
3289 * we've unlocked the page, so we can't update
3290 * the mapping's writeback index, just update
3293 wbc->nr_to_write -= *nr_written;
3304 * helper for __extent_writepage. This calls the writepage start hooks,
3305 * and does the loop to map the page into extents and bios.
3307 * We return 1 if the IO is started and the page is unlocked,
3308 * 0 if all went well (page still locked)
3309 * < 0 if there were errors (page still locked)
3311 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3313 struct writeback_control *wbc,
3314 struct extent_page_data *epd,
3316 unsigned long nr_written,
3317 int write_flags, int *nr_ret)
3319 struct extent_io_tree *tree = epd->tree;
3320 u64 start = page_offset(page);
3321 u64 page_end = start + PAGE_SIZE - 1;
3328 struct extent_state *cached_state = NULL;
3329 struct extent_map *em;
3330 struct block_device *bdev;
3331 size_t pg_offset = 0;
3337 if (tree->ops && tree->ops->writepage_start_hook) {
3338 ret = tree->ops->writepage_start_hook(page, start,
3341 /* Fixup worker will requeue */
3343 wbc->pages_skipped++;
3345 redirty_page_for_writepage(wbc, page);
3347 update_nr_written(page, wbc, nr_written);
3355 * we don't want to touch the inode after unlocking the page,
3356 * so we update the mapping writeback index now
3358 update_nr_written(page, wbc, nr_written + 1);
3361 if (i_size <= start) {
3362 if (tree->ops && tree->ops->writepage_end_io_hook)
3363 tree->ops->writepage_end_io_hook(page, start,
3368 blocksize = inode->i_sb->s_blocksize;
3370 while (cur <= end) {
3372 unsigned long max_nr;
3374 if (cur >= i_size) {
3375 if (tree->ops && tree->ops->writepage_end_io_hook)
3376 tree->ops->writepage_end_io_hook(page, cur,
3380 em = epd->get_extent(inode, page, pg_offset, cur,
3382 if (IS_ERR_OR_NULL(em)) {
3384 ret = PTR_ERR_OR_ZERO(em);
3388 extent_offset = cur - em->start;
3389 em_end = extent_map_end(em);
3390 BUG_ON(em_end <= cur);
3392 iosize = min(em_end - cur, end - cur + 1);
3393 iosize = ALIGN(iosize, blocksize);
3394 sector = (em->block_start + extent_offset) >> 9;
3396 block_start = em->block_start;
3397 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3398 free_extent_map(em);
3402 * compressed and inline extents are written through other
3405 if (compressed || block_start == EXTENT_MAP_HOLE ||
3406 block_start == EXTENT_MAP_INLINE) {
3408 * end_io notification does not happen here for
3409 * compressed extents
3411 if (!compressed && tree->ops &&
3412 tree->ops->writepage_end_io_hook)
3413 tree->ops->writepage_end_io_hook(page, cur,
3416 else if (compressed) {
3417 /* we don't want to end_page_writeback on
3418 * a compressed extent. this happens
3425 pg_offset += iosize;
3429 max_nr = (i_size >> PAGE_SHIFT) + 1;
3431 set_range_writeback(tree, cur, cur + iosize - 1);
3432 if (!PageWriteback(page)) {
3433 btrfs_err(BTRFS_I(inode)->root->fs_info,
3434 "page %lu not writeback, cur %llu end %llu",
3435 page->index, cur, end);
3438 ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
3439 page, sector, iosize, pg_offset,
3440 bdev, &epd->bio, max_nr,
3441 end_bio_extent_writepage,
3447 pg_offset += iosize;
3455 /* drop our reference on any cached states */
3456 free_extent_state(cached_state);
3461 * the writepage semantics are similar to regular writepage. extent
3462 * records are inserted to lock ranges in the tree, and as dirty areas
3463 * are found, they are marked writeback. Then the lock bits are removed
3464 * and the end_io handler clears the writeback ranges
3466 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3469 struct inode *inode = page->mapping->host;
3470 struct extent_page_data *epd = data;
3471 u64 start = page_offset(page);
3472 u64 page_end = start + PAGE_SIZE - 1;
3475 size_t pg_offset = 0;
3476 loff_t i_size = i_size_read(inode);
3477 unsigned long end_index = i_size >> PAGE_SHIFT;
3478 int write_flags = 0;
3479 unsigned long nr_written = 0;
3481 if (wbc->sync_mode == WB_SYNC_ALL)
3482 write_flags = WRITE_SYNC;
3484 trace___extent_writepage(page, inode, wbc);
3486 WARN_ON(!PageLocked(page));
3488 ClearPageError(page);
3490 pg_offset = i_size & (PAGE_SIZE - 1);
3491 if (page->index > end_index ||
3492 (page->index == end_index && !pg_offset)) {
3493 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3498 if (page->index == end_index) {
3501 userpage = kmap_atomic(page);
3502 memset(userpage + pg_offset, 0,
3503 PAGE_SIZE - pg_offset);
3504 kunmap_atomic(userpage);
3505 flush_dcache_page(page);
3510 set_page_extent_mapped(page);
3512 ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
3518 ret = __extent_writepage_io(inode, page, wbc, epd,
3519 i_size, nr_written, write_flags, &nr);
3525 /* make sure the mapping tag for page dirty gets cleared */
3526 set_page_writeback(page);
3527 end_page_writeback(page);
3529 if (PageError(page)) {
3530 ret = ret < 0 ? ret : -EIO;
3531 end_extent_writepage(page, ret, start, page_end);
3540 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3542 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3543 TASK_UNINTERRUPTIBLE);
3546 static noinline_for_stack int
3547 lock_extent_buffer_for_io(struct extent_buffer *eb,
3548 struct btrfs_fs_info *fs_info,
3549 struct extent_page_data *epd)
3551 unsigned long i, num_pages;
3555 if (!btrfs_try_tree_write_lock(eb)) {
3557 flush_write_bio(epd);
3558 btrfs_tree_lock(eb);
3561 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3562 btrfs_tree_unlock(eb);
3566 flush_write_bio(epd);
3570 wait_on_extent_buffer_writeback(eb);
3571 btrfs_tree_lock(eb);
3572 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3574 btrfs_tree_unlock(eb);
3579 * We need to do this to prevent races in people who check if the eb is
3580 * under IO since we can end up having no IO bits set for a short period
3583 spin_lock(&eb->refs_lock);
3584 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3585 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3586 spin_unlock(&eb->refs_lock);
3587 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3588 __percpu_counter_add(&fs_info->dirty_metadata_bytes,
3590 fs_info->dirty_metadata_batch);
3593 spin_unlock(&eb->refs_lock);
3596 btrfs_tree_unlock(eb);
3601 num_pages = num_extent_pages(eb->start, eb->len);
3602 for (i = 0; i < num_pages; i++) {
3603 struct page *p = eb->pages[i];
3605 if (!trylock_page(p)) {
3607 flush_write_bio(epd);
3617 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3619 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3620 smp_mb__after_atomic();
3621 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3624 static void set_btree_ioerr(struct page *page)
3626 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3627 struct btrfs_inode *btree_ino = BTRFS_I(eb->fs_info->btree_inode);
3630 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3634 * If writeback for a btree extent that doesn't belong to a log tree
3635 * failed, increment the counter transaction->eb_write_errors.
3636 * We do this because while the transaction is running and before it's
3637 * committing (when we call filemap_fdata[write|wait]_range against
3638 * the btree inode), we might have
3639 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3640 * returns an error or an error happens during writeback, when we're
3641 * committing the transaction we wouldn't know about it, since the pages
3642 * can be no longer dirty nor marked anymore for writeback (if a
3643 * subsequent modification to the extent buffer didn't happen before the
3644 * transaction commit), which makes filemap_fdata[write|wait]_range not
3645 * able to find the pages tagged with SetPageError at transaction
3646 * commit time. So if this happens we must abort the transaction,
3647 * otherwise we commit a super block with btree roots that point to
3648 * btree nodes/leafs whose content on disk is invalid - either garbage
3649 * or the content of some node/leaf from a past generation that got
3650 * cowed or deleted and is no longer valid.
3652 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3653 * not be enough - we need to distinguish between log tree extents vs
3654 * non-log tree extents, and the next filemap_fdatawait_range() call
3655 * will catch and clear such errors in the mapping - and that call might
3656 * be from a log sync and not from a transaction commit. Also, checking
3657 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3658 * not done and would not be reliable - the eb might have been released
3659 * from memory and reading it back again means that flag would not be
3660 * set (since it's a runtime flag, not persisted on disk).
3662 * Using the flags below in the btree inode also makes us achieve the
3663 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3664 * writeback for all dirty pages and before filemap_fdatawait_range()
3665 * is called, the writeback for all dirty pages had already finished
3666 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3667 * filemap_fdatawait_range() would return success, as it could not know
3668 * that writeback errors happened (the pages were no longer tagged for
3671 switch (eb->log_index) {
3673 set_bit(BTRFS_INODE_BTREE_ERR, &btree_ino->runtime_flags);
3676 set_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags);
3679 set_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags);
3682 BUG(); /* unexpected, logic error */
3686 static void end_bio_extent_buffer_writepage(struct bio *bio)
3688 struct bio_vec *bvec;
3689 struct extent_buffer *eb;
3692 bio_for_each_segment_all(bvec, bio, i) {
3693 struct page *page = bvec->bv_page;
3695 eb = (struct extent_buffer *)page->private;
3697 done = atomic_dec_and_test(&eb->io_pages);
3699 if (bio->bi_error ||
3700 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3701 ClearPageUptodate(page);
3702 set_btree_ioerr(page);
3705 end_page_writeback(page);
3710 end_extent_buffer_writeback(eb);
3716 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3717 struct btrfs_fs_info *fs_info,
3718 struct writeback_control *wbc,
3719 struct extent_page_data *epd)
3721 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3722 struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
3723 u64 offset = eb->start;
3724 unsigned long i, num_pages;
3725 unsigned long bio_flags = 0;
3726 int write_flags = (epd->sync_io ? WRITE_SYNC : 0) | REQ_META;
3729 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3730 num_pages = num_extent_pages(eb->start, eb->len);
3731 atomic_set(&eb->io_pages, num_pages);
3732 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3733 bio_flags = EXTENT_BIO_TREE_LOG;
3735 for (i = 0; i < num_pages; i++) {
3736 struct page *p = eb->pages[i];
3738 clear_page_dirty_for_io(p);
3739 set_page_writeback(p);
3740 ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
3741 p, offset >> 9, PAGE_SIZE, 0, bdev,
3743 end_bio_extent_buffer_writepage,
3744 0, epd->bio_flags, bio_flags, false);
3745 epd->bio_flags = bio_flags;
3748 end_page_writeback(p);
3749 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3750 end_extent_buffer_writeback(eb);
3754 offset += PAGE_SIZE;
3755 update_nr_written(p, wbc, 1);
3759 if (unlikely(ret)) {
3760 for (; i < num_pages; i++) {
3761 struct page *p = eb->pages[i];
3762 clear_page_dirty_for_io(p);
3770 int btree_write_cache_pages(struct address_space *mapping,
3771 struct writeback_control *wbc)
3773 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3774 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3775 struct extent_buffer *eb, *prev_eb = NULL;
3776 struct extent_page_data epd = {
3780 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3785 int nr_to_write_done = 0;
3786 struct pagevec pvec;
3789 pgoff_t end; /* Inclusive */
3793 pagevec_init(&pvec, 0);
3794 if (wbc->range_cyclic) {
3795 index = mapping->writeback_index; /* Start from prev offset */
3798 index = wbc->range_start >> PAGE_SHIFT;
3799 end = wbc->range_end >> PAGE_SHIFT;
3802 if (wbc->sync_mode == WB_SYNC_ALL)
3803 tag = PAGECACHE_TAG_TOWRITE;
3805 tag = PAGECACHE_TAG_DIRTY;
3807 if (wbc->sync_mode == WB_SYNC_ALL)
3808 tag_pages_for_writeback(mapping, index, end);
3809 while (!done && !nr_to_write_done && (index <= end) &&
3810 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3811 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3815 for (i = 0; i < nr_pages; i++) {
3816 struct page *page = pvec.pages[i];
3818 if (!PagePrivate(page))
3821 if (!wbc->range_cyclic && page->index > end) {
3826 spin_lock(&mapping->private_lock);
3827 if (!PagePrivate(page)) {
3828 spin_unlock(&mapping->private_lock);
3832 eb = (struct extent_buffer *)page->private;
3835 * Shouldn't happen and normally this would be a BUG_ON
3836 * but no sense in crashing the users box for something
3837 * we can survive anyway.
3840 spin_unlock(&mapping->private_lock);
3844 if (eb == prev_eb) {
3845 spin_unlock(&mapping->private_lock);
3849 ret = atomic_inc_not_zero(&eb->refs);
3850 spin_unlock(&mapping->private_lock);
3855 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3857 free_extent_buffer(eb);
3861 ret = write_one_eb(eb, fs_info, wbc, &epd);
3864 free_extent_buffer(eb);
3867 free_extent_buffer(eb);
3870 * the filesystem may choose to bump up nr_to_write.
3871 * We have to make sure to honor the new nr_to_write
3874 nr_to_write_done = wbc->nr_to_write <= 0;
3876 pagevec_release(&pvec);
3879 if (!scanned && !done) {
3881 * We hit the last page and there is more work to be done: wrap
3882 * back to the start of the file
3888 flush_write_bio(&epd);
3893 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3894 * @mapping: address space structure to write
3895 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3896 * @writepage: function called for each page
3897 * @data: data passed to writepage function
3899 * If a page is already under I/O, write_cache_pages() skips it, even
3900 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3901 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3902 * and msync() need to guarantee that all the data which was dirty at the time
3903 * the call was made get new I/O started against them. If wbc->sync_mode is
3904 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3905 * existing IO to complete.
3907 static int extent_write_cache_pages(struct extent_io_tree *tree,
3908 struct address_space *mapping,
3909 struct writeback_control *wbc,
3910 writepage_t writepage, void *data,
3911 void (*flush_fn)(void *))
3913 struct inode *inode = mapping->host;
3916 int nr_to_write_done = 0;
3917 struct pagevec pvec;
3920 pgoff_t end; /* Inclusive */
3922 int range_whole = 0;
3927 * We have to hold onto the inode so that ordered extents can do their
3928 * work when the IO finishes. The alternative to this is failing to add
3929 * an ordered extent if the igrab() fails there and that is a huge pain
3930 * to deal with, so instead just hold onto the inode throughout the
3931 * writepages operation. If it fails here we are freeing up the inode
3932 * anyway and we'd rather not waste our time writing out stuff that is
3933 * going to be truncated anyway.
3938 pagevec_init(&pvec, 0);
3939 if (wbc->range_cyclic) {
3940 index = mapping->writeback_index; /* Start from prev offset */
3943 index = wbc->range_start >> PAGE_SHIFT;
3944 end = wbc->range_end >> PAGE_SHIFT;
3945 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
3949 if (wbc->sync_mode == WB_SYNC_ALL)
3950 tag = PAGECACHE_TAG_TOWRITE;
3952 tag = PAGECACHE_TAG_DIRTY;
3954 if (wbc->sync_mode == WB_SYNC_ALL)
3955 tag_pages_for_writeback(mapping, index, end);
3957 while (!done && !nr_to_write_done && (index <= end) &&
3958 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3959 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3963 for (i = 0; i < nr_pages; i++) {
3964 struct page *page = pvec.pages[i];
3966 done_index = page->index;
3968 * At this point we hold neither mapping->tree_lock nor
3969 * lock on the page itself: the page may be truncated or
3970 * invalidated (changing page->mapping to NULL), or even
3971 * swizzled back from swapper_space to tmpfs file
3974 if (!trylock_page(page)) {
3979 if (unlikely(page->mapping != mapping)) {
3984 if (!wbc->range_cyclic && page->index > end) {
3990 if (wbc->sync_mode != WB_SYNC_NONE) {
3991 if (PageWriteback(page))
3993 wait_on_page_writeback(page);
3996 if (PageWriteback(page) ||
3997 !clear_page_dirty_for_io(page)) {
4002 ret = (*writepage)(page, wbc, data);
4004 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
4010 * done_index is set past this page,
4011 * so media errors will not choke
4012 * background writeout for the entire
4013 * file. This has consequences for
4014 * range_cyclic semantics (ie. it may
4015 * not be suitable for data integrity
4018 done_index = page->index + 1;
4024 * the filesystem may choose to bump up nr_to_write.
4025 * We have to make sure to honor the new nr_to_write
4028 nr_to_write_done = wbc->nr_to_write <= 0;
4030 pagevec_release(&pvec);
4033 if (!scanned && !done) {
4035 * We hit the last page and there is more work to be done: wrap
4036 * back to the start of the file
4043 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4044 mapping->writeback_index = done_index;
4046 btrfs_add_delayed_iput(inode);
4050 static void flush_epd_write_bio(struct extent_page_data *epd)
4055 bio_set_op_attrs(epd->bio, REQ_OP_WRITE,
4056 epd->sync_io ? WRITE_SYNC : 0);
4058 ret = submit_one_bio(epd->bio, 0, epd->bio_flags);
4059 BUG_ON(ret < 0); /* -ENOMEM */
4064 static noinline void flush_write_bio(void *data)
4066 struct extent_page_data *epd = data;
4067 flush_epd_write_bio(epd);
4070 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
4071 get_extent_t *get_extent,
4072 struct writeback_control *wbc)
4075 struct extent_page_data epd = {
4078 .get_extent = get_extent,
4080 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4084 ret = __extent_writepage(page, wbc, &epd);
4086 flush_epd_write_bio(&epd);
4090 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
4091 u64 start, u64 end, get_extent_t *get_extent,
4095 struct address_space *mapping = inode->i_mapping;
4097 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4100 struct extent_page_data epd = {
4103 .get_extent = get_extent,
4105 .sync_io = mode == WB_SYNC_ALL,
4108 struct writeback_control wbc_writepages = {
4110 .nr_to_write = nr_pages * 2,
4111 .range_start = start,
4112 .range_end = end + 1,
4115 while (start <= end) {
4116 page = find_get_page(mapping, start >> PAGE_SHIFT);
4117 if (clear_page_dirty_for_io(page))
4118 ret = __extent_writepage(page, &wbc_writepages, &epd);
4120 if (tree->ops && tree->ops->writepage_end_io_hook)
4121 tree->ops->writepage_end_io_hook(page, start,
4122 start + PAGE_SIZE - 1,
4130 flush_epd_write_bio(&epd);
4134 int extent_writepages(struct extent_io_tree *tree,
4135 struct address_space *mapping,
4136 get_extent_t *get_extent,
4137 struct writeback_control *wbc)
4140 struct extent_page_data epd = {
4143 .get_extent = get_extent,
4145 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4149 ret = extent_write_cache_pages(tree, mapping, wbc,
4150 __extent_writepage, &epd,
4152 flush_epd_write_bio(&epd);
4156 int extent_readpages(struct extent_io_tree *tree,
4157 struct address_space *mapping,
4158 struct list_head *pages, unsigned nr_pages,
4159 get_extent_t get_extent)
4161 struct bio *bio = NULL;
4163 unsigned long bio_flags = 0;
4164 struct page *pagepool[16];
4166 struct extent_map *em_cached = NULL;
4168 u64 prev_em_start = (u64)-1;
4170 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
4171 page = list_entry(pages->prev, struct page, lru);
4173 prefetchw(&page->flags);
4174 list_del(&page->lru);
4175 if (add_to_page_cache_lru(page, mapping,
4177 readahead_gfp_mask(mapping))) {
4182 pagepool[nr++] = page;
4183 if (nr < ARRAY_SIZE(pagepool))
4185 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4186 &bio, 0, &bio_flags, &prev_em_start);
4190 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4191 &bio, 0, &bio_flags, &prev_em_start);
4194 free_extent_map(em_cached);
4196 BUG_ON(!list_empty(pages));
4198 return submit_one_bio(bio, 0, bio_flags);
4203 * basic invalidatepage code, this waits on any locked or writeback
4204 * ranges corresponding to the page, and then deletes any extent state
4205 * records from the tree
4207 int extent_invalidatepage(struct extent_io_tree *tree,
4208 struct page *page, unsigned long offset)
4210 struct extent_state *cached_state = NULL;
4211 u64 start = page_offset(page);
4212 u64 end = start + PAGE_SIZE - 1;
4213 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4215 start += ALIGN(offset, blocksize);
4219 lock_extent_bits(tree, start, end, &cached_state);
4220 wait_on_page_writeback(page);
4221 clear_extent_bit(tree, start, end,
4222 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
4223 EXTENT_DO_ACCOUNTING,
4224 1, 1, &cached_state, GFP_NOFS);
4229 * a helper for releasepage, this tests for areas of the page that
4230 * are locked or under IO and drops the related state bits if it is safe
4233 static int try_release_extent_state(struct extent_map_tree *map,
4234 struct extent_io_tree *tree,
4235 struct page *page, gfp_t mask)
4237 u64 start = page_offset(page);
4238 u64 end = start + PAGE_SIZE - 1;
4241 if (test_range_bit(tree, start, end,
4242 EXTENT_IOBITS, 0, NULL))
4245 if ((mask & GFP_NOFS) == GFP_NOFS)
4248 * at this point we can safely clear everything except the
4249 * locked bit and the nodatasum bit
4251 ret = clear_extent_bit(tree, start, end,
4252 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4255 /* if clear_extent_bit failed for enomem reasons,
4256 * we can't allow the release to continue.
4267 * a helper for releasepage. As long as there are no locked extents
4268 * in the range corresponding to the page, both state records and extent
4269 * map records are removed
4271 int try_release_extent_mapping(struct extent_map_tree *map,
4272 struct extent_io_tree *tree, struct page *page,
4275 struct extent_map *em;
4276 u64 start = page_offset(page);
4277 u64 end = start + PAGE_SIZE - 1;
4279 if (gfpflags_allow_blocking(mask) &&
4280 page->mapping->host->i_size > SZ_16M) {
4282 while (start <= end) {
4283 len = end - start + 1;
4284 write_lock(&map->lock);
4285 em = lookup_extent_mapping(map, start, len);
4287 write_unlock(&map->lock);
4290 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4291 em->start != start) {
4292 write_unlock(&map->lock);
4293 free_extent_map(em);
4296 if (!test_range_bit(tree, em->start,
4297 extent_map_end(em) - 1,
4298 EXTENT_LOCKED | EXTENT_WRITEBACK,
4300 remove_extent_mapping(map, em);
4301 /* once for the rb tree */
4302 free_extent_map(em);
4304 start = extent_map_end(em);
4305 write_unlock(&map->lock);
4308 free_extent_map(em);
4311 return try_release_extent_state(map, tree, page, mask);
4315 * helper function for fiemap, which doesn't want to see any holes.
4316 * This maps until we find something past 'last'
4318 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4321 get_extent_t *get_extent)
4323 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
4324 struct extent_map *em;
4331 len = last - offset;
4334 len = ALIGN(len, sectorsize);
4335 em = get_extent(inode, NULL, 0, offset, len, 0);
4336 if (IS_ERR_OR_NULL(em))
4339 /* if this isn't a hole return it */
4340 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
4341 em->block_start != EXTENT_MAP_HOLE) {
4345 /* this is a hole, advance to the next extent */
4346 offset = extent_map_end(em);
4347 free_extent_map(em);
4354 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4355 __u64 start, __u64 len, get_extent_t *get_extent)
4359 u64 max = start + len;
4363 u64 last_for_get_extent = 0;
4365 u64 isize = i_size_read(inode);
4366 struct btrfs_key found_key;
4367 struct extent_map *em = NULL;
4368 struct extent_state *cached_state = NULL;
4369 struct btrfs_path *path;
4370 struct btrfs_root *root = BTRFS_I(inode)->root;
4379 path = btrfs_alloc_path();
4382 path->leave_spinning = 1;
4384 start = round_down(start, BTRFS_I(inode)->root->sectorsize);
4385 len = round_up(max, BTRFS_I(inode)->root->sectorsize) - start;
4388 * lookup the last file extent. We're not using i_size here
4389 * because there might be preallocation past i_size
4391 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), -1,
4394 btrfs_free_path(path);
4403 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4404 found_type = found_key.type;
4406 /* No extents, but there might be delalloc bits */
4407 if (found_key.objectid != btrfs_ino(inode) ||
4408 found_type != BTRFS_EXTENT_DATA_KEY) {
4409 /* have to trust i_size as the end */
4411 last_for_get_extent = isize;
4414 * remember the start of the last extent. There are a
4415 * bunch of different factors that go into the length of the
4416 * extent, so its much less complex to remember where it started
4418 last = found_key.offset;
4419 last_for_get_extent = last + 1;
4421 btrfs_release_path(path);
4424 * we might have some extents allocated but more delalloc past those
4425 * extents. so, we trust isize unless the start of the last extent is
4430 last_for_get_extent = isize;
4433 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4436 em = get_extent_skip_holes(inode, start, last_for_get_extent,
4446 u64 offset_in_extent = 0;
4448 /* break if the extent we found is outside the range */
4449 if (em->start >= max || extent_map_end(em) < off)
4453 * get_extent may return an extent that starts before our
4454 * requested range. We have to make sure the ranges
4455 * we return to fiemap always move forward and don't
4456 * overlap, so adjust the offsets here
4458 em_start = max(em->start, off);
4461 * record the offset from the start of the extent
4462 * for adjusting the disk offset below. Only do this if the
4463 * extent isn't compressed since our in ram offset may be past
4464 * what we have actually allocated on disk.
4466 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4467 offset_in_extent = em_start - em->start;
4468 em_end = extent_map_end(em);
4469 em_len = em_end - em_start;
4474 * bump off for our next call to get_extent
4476 off = extent_map_end(em);
4480 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4482 flags |= FIEMAP_EXTENT_LAST;
4483 } else if (em->block_start == EXTENT_MAP_INLINE) {
4484 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4485 FIEMAP_EXTENT_NOT_ALIGNED);
4486 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4487 flags |= (FIEMAP_EXTENT_DELALLOC |
4488 FIEMAP_EXTENT_UNKNOWN);
4489 } else if (fieinfo->fi_extents_max) {
4490 u64 bytenr = em->block_start -
4491 (em->start - em->orig_start);
4493 disko = em->block_start + offset_in_extent;
4496 * As btrfs supports shared space, this information
4497 * can be exported to userspace tools via
4498 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4499 * then we're just getting a count and we can skip the
4502 ret = btrfs_check_shared(NULL, root->fs_info,
4504 btrfs_ino(inode), bytenr);
4508 flags |= FIEMAP_EXTENT_SHARED;
4511 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4512 flags |= FIEMAP_EXTENT_ENCODED;
4513 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4514 flags |= FIEMAP_EXTENT_UNWRITTEN;
4516 free_extent_map(em);
4518 if ((em_start >= last) || em_len == (u64)-1 ||
4519 (last == (u64)-1 && isize <= em_end)) {
4520 flags |= FIEMAP_EXTENT_LAST;
4524 /* now scan forward to see if this is really the last extent. */
4525 em = get_extent_skip_holes(inode, off, last_for_get_extent,
4532 flags |= FIEMAP_EXTENT_LAST;
4535 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
4544 free_extent_map(em);
4546 btrfs_free_path(path);
4547 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4548 &cached_state, GFP_NOFS);
4552 static void __free_extent_buffer(struct extent_buffer *eb)
4554 btrfs_leak_debug_del(&eb->leak_list);
4555 kmem_cache_free(extent_buffer_cache, eb);
4558 int extent_buffer_under_io(struct extent_buffer *eb)
4560 return (atomic_read(&eb->io_pages) ||
4561 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4562 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4566 * Helper for releasing extent buffer page.
4568 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb)
4570 unsigned long index;
4572 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4574 BUG_ON(extent_buffer_under_io(eb));
4576 index = num_extent_pages(eb->start, eb->len);
4582 page = eb->pages[index];
4586 spin_lock(&page->mapping->private_lock);
4588 * We do this since we'll remove the pages after we've
4589 * removed the eb from the radix tree, so we could race
4590 * and have this page now attached to the new eb. So
4591 * only clear page_private if it's still connected to
4594 if (PagePrivate(page) &&
4595 page->private == (unsigned long)eb) {
4596 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4597 BUG_ON(PageDirty(page));
4598 BUG_ON(PageWriteback(page));
4600 * We need to make sure we haven't be attached
4603 ClearPagePrivate(page);
4604 set_page_private(page, 0);
4605 /* One for the page private */
4610 spin_unlock(&page->mapping->private_lock);
4612 /* One for when we allocated the page */
4614 } while (index != 0);
4618 * Helper for releasing the extent buffer.
4620 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4622 btrfs_release_extent_buffer_page(eb);
4623 __free_extent_buffer(eb);
4626 static struct extent_buffer *
4627 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4630 struct extent_buffer *eb = NULL;
4632 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4635 eb->fs_info = fs_info;
4637 rwlock_init(&eb->lock);
4638 atomic_set(&eb->write_locks, 0);
4639 atomic_set(&eb->read_locks, 0);
4640 atomic_set(&eb->blocking_readers, 0);
4641 atomic_set(&eb->blocking_writers, 0);
4642 atomic_set(&eb->spinning_readers, 0);
4643 atomic_set(&eb->spinning_writers, 0);
4644 eb->lock_nested = 0;
4645 init_waitqueue_head(&eb->write_lock_wq);
4646 init_waitqueue_head(&eb->read_lock_wq);
4648 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4650 spin_lock_init(&eb->refs_lock);
4651 atomic_set(&eb->refs, 1);
4652 atomic_set(&eb->io_pages, 0);
4655 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4657 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4658 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4659 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4664 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4668 struct extent_buffer *new;
4669 unsigned long num_pages = num_extent_pages(src->start, src->len);
4671 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
4675 for (i = 0; i < num_pages; i++) {
4676 p = alloc_page(GFP_NOFS);
4678 btrfs_release_extent_buffer(new);
4681 attach_extent_buffer_page(new, p);
4682 WARN_ON(PageDirty(p));
4687 copy_extent_buffer(new, src, 0, 0, src->len);
4688 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4689 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4694 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4695 u64 start, unsigned long len)
4697 struct extent_buffer *eb;
4698 unsigned long num_pages;
4701 num_pages = num_extent_pages(start, len);
4703 eb = __alloc_extent_buffer(fs_info, start, len);
4707 for (i = 0; i < num_pages; i++) {
4708 eb->pages[i] = alloc_page(GFP_NOFS);
4712 set_extent_buffer_uptodate(eb);
4713 btrfs_set_header_nritems(eb, 0);
4714 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4719 __free_page(eb->pages[i - 1]);
4720 __free_extent_buffer(eb);
4724 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4725 u64 start, u32 nodesize)
4731 * Called only from tests that don't always have a fs_info
4736 len = fs_info->tree_root->nodesize;
4739 return __alloc_dummy_extent_buffer(fs_info, start, len);
4742 static void check_buffer_tree_ref(struct extent_buffer *eb)
4745 /* the ref bit is tricky. We have to make sure it is set
4746 * if we have the buffer dirty. Otherwise the
4747 * code to free a buffer can end up dropping a dirty
4750 * Once the ref bit is set, it won't go away while the
4751 * buffer is dirty or in writeback, and it also won't
4752 * go away while we have the reference count on the
4755 * We can't just set the ref bit without bumping the
4756 * ref on the eb because free_extent_buffer might
4757 * see the ref bit and try to clear it. If this happens
4758 * free_extent_buffer might end up dropping our original
4759 * ref by mistake and freeing the page before we are able
4760 * to add one more ref.
4762 * So bump the ref count first, then set the bit. If someone
4763 * beat us to it, drop the ref we added.
4765 refs = atomic_read(&eb->refs);
4766 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4769 spin_lock(&eb->refs_lock);
4770 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4771 atomic_inc(&eb->refs);
4772 spin_unlock(&eb->refs_lock);
4775 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
4776 struct page *accessed)
4778 unsigned long num_pages, i;
4780 check_buffer_tree_ref(eb);
4782 num_pages = num_extent_pages(eb->start, eb->len);
4783 for (i = 0; i < num_pages; i++) {
4784 struct page *p = eb->pages[i];
4787 mark_page_accessed(p);
4791 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
4794 struct extent_buffer *eb;
4797 eb = radix_tree_lookup(&fs_info->buffer_radix,
4798 start >> PAGE_SHIFT);
4799 if (eb && atomic_inc_not_zero(&eb->refs)) {
4802 * Lock our eb's refs_lock to avoid races with
4803 * free_extent_buffer. When we get our eb it might be flagged
4804 * with EXTENT_BUFFER_STALE and another task running
4805 * free_extent_buffer might have seen that flag set,
4806 * eb->refs == 2, that the buffer isn't under IO (dirty and
4807 * writeback flags not set) and it's still in the tree (flag
4808 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4809 * of decrementing the extent buffer's reference count twice.
4810 * So here we could race and increment the eb's reference count,
4811 * clear its stale flag, mark it as dirty and drop our reference
4812 * before the other task finishes executing free_extent_buffer,
4813 * which would later result in an attempt to free an extent
4814 * buffer that is dirty.
4816 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
4817 spin_lock(&eb->refs_lock);
4818 spin_unlock(&eb->refs_lock);
4820 mark_extent_buffer_accessed(eb, NULL);
4828 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4829 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
4830 u64 start, u32 nodesize)
4832 struct extent_buffer *eb, *exists = NULL;
4835 eb = find_extent_buffer(fs_info, start);
4838 eb = alloc_dummy_extent_buffer(fs_info, start, nodesize);
4841 eb->fs_info = fs_info;
4843 ret = radix_tree_preload(GFP_NOFS);
4846 spin_lock(&fs_info->buffer_lock);
4847 ret = radix_tree_insert(&fs_info->buffer_radix,
4848 start >> PAGE_SHIFT, eb);
4849 spin_unlock(&fs_info->buffer_lock);
4850 radix_tree_preload_end();
4851 if (ret == -EEXIST) {
4852 exists = find_extent_buffer(fs_info, start);
4858 check_buffer_tree_ref(eb);
4859 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4862 * We will free dummy extent buffer's if they come into
4863 * free_extent_buffer with a ref count of 2, but if we are using this we
4864 * want the buffers to stay in memory until we're done with them, so
4865 * bump the ref count again.
4867 atomic_inc(&eb->refs);
4870 btrfs_release_extent_buffer(eb);
4875 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
4878 unsigned long len = fs_info->tree_root->nodesize;
4879 unsigned long num_pages = num_extent_pages(start, len);
4881 unsigned long index = start >> PAGE_SHIFT;
4882 struct extent_buffer *eb;
4883 struct extent_buffer *exists = NULL;
4885 struct address_space *mapping = fs_info->btree_inode->i_mapping;
4889 if (!IS_ALIGNED(start, fs_info->tree_root->sectorsize)) {
4890 btrfs_err(fs_info, "bad tree block start %llu", start);
4891 return ERR_PTR(-EINVAL);
4894 eb = find_extent_buffer(fs_info, start);
4898 eb = __alloc_extent_buffer(fs_info, start, len);
4900 return ERR_PTR(-ENOMEM);
4902 for (i = 0; i < num_pages; i++, index++) {
4903 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
4905 exists = ERR_PTR(-ENOMEM);
4909 spin_lock(&mapping->private_lock);
4910 if (PagePrivate(p)) {
4912 * We could have already allocated an eb for this page
4913 * and attached one so lets see if we can get a ref on
4914 * the existing eb, and if we can we know it's good and
4915 * we can just return that one, else we know we can just
4916 * overwrite page->private.
4918 exists = (struct extent_buffer *)p->private;
4919 if (atomic_inc_not_zero(&exists->refs)) {
4920 spin_unlock(&mapping->private_lock);
4923 mark_extent_buffer_accessed(exists, p);
4929 * Do this so attach doesn't complain and we need to
4930 * drop the ref the old guy had.
4932 ClearPagePrivate(p);
4933 WARN_ON(PageDirty(p));
4936 attach_extent_buffer_page(eb, p);
4937 spin_unlock(&mapping->private_lock);
4938 WARN_ON(PageDirty(p));
4940 if (!PageUptodate(p))
4944 * see below about how we avoid a nasty race with release page
4945 * and why we unlock later
4949 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4951 ret = radix_tree_preload(GFP_NOFS);
4953 exists = ERR_PTR(ret);
4957 spin_lock(&fs_info->buffer_lock);
4958 ret = radix_tree_insert(&fs_info->buffer_radix,
4959 start >> PAGE_SHIFT, eb);
4960 spin_unlock(&fs_info->buffer_lock);
4961 radix_tree_preload_end();
4962 if (ret == -EEXIST) {
4963 exists = find_extent_buffer(fs_info, start);
4969 /* add one reference for the tree */
4970 check_buffer_tree_ref(eb);
4971 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4974 * there is a race where release page may have
4975 * tried to find this extent buffer in the radix
4976 * but failed. It will tell the VM it is safe to
4977 * reclaim the, and it will clear the page private bit.
4978 * We must make sure to set the page private bit properly
4979 * after the extent buffer is in the radix tree so
4980 * it doesn't get lost
4982 SetPageChecked(eb->pages[0]);
4983 for (i = 1; i < num_pages; i++) {
4985 ClearPageChecked(p);
4988 unlock_page(eb->pages[0]);
4992 WARN_ON(!atomic_dec_and_test(&eb->refs));
4993 for (i = 0; i < num_pages; i++) {
4995 unlock_page(eb->pages[i]);
4998 btrfs_release_extent_buffer(eb);
5002 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5004 struct extent_buffer *eb =
5005 container_of(head, struct extent_buffer, rcu_head);
5007 __free_extent_buffer(eb);
5010 /* Expects to have eb->eb_lock already held */
5011 static int release_extent_buffer(struct extent_buffer *eb)
5013 WARN_ON(atomic_read(&eb->refs) == 0);
5014 if (atomic_dec_and_test(&eb->refs)) {
5015 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5016 struct btrfs_fs_info *fs_info = eb->fs_info;
5018 spin_unlock(&eb->refs_lock);
5020 spin_lock(&fs_info->buffer_lock);
5021 radix_tree_delete(&fs_info->buffer_radix,
5022 eb->start >> PAGE_SHIFT);
5023 spin_unlock(&fs_info->buffer_lock);
5025 spin_unlock(&eb->refs_lock);
5028 /* Should be safe to release our pages at this point */
5029 btrfs_release_extent_buffer_page(eb);
5030 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5031 if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) {
5032 __free_extent_buffer(eb);
5036 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5039 spin_unlock(&eb->refs_lock);
5044 void free_extent_buffer(struct extent_buffer *eb)
5052 refs = atomic_read(&eb->refs);
5055 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5060 spin_lock(&eb->refs_lock);
5061 if (atomic_read(&eb->refs) == 2 &&
5062 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
5063 atomic_dec(&eb->refs);
5065 if (atomic_read(&eb->refs) == 2 &&
5066 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5067 !extent_buffer_under_io(eb) &&
5068 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5069 atomic_dec(&eb->refs);
5072 * I know this is terrible, but it's temporary until we stop tracking
5073 * the uptodate bits and such for the extent buffers.
5075 release_extent_buffer(eb);
5078 void free_extent_buffer_stale(struct extent_buffer *eb)
5083 spin_lock(&eb->refs_lock);
5084 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5086 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5087 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5088 atomic_dec(&eb->refs);
5089 release_extent_buffer(eb);
5092 void clear_extent_buffer_dirty(struct extent_buffer *eb)
5095 unsigned long num_pages;
5098 num_pages = num_extent_pages(eb->start, eb->len);
5100 for (i = 0; i < num_pages; i++) {
5101 page = eb->pages[i];
5102 if (!PageDirty(page))
5106 WARN_ON(!PagePrivate(page));
5108 clear_page_dirty_for_io(page);
5109 spin_lock_irq(&page->mapping->tree_lock);
5110 if (!PageDirty(page)) {
5111 radix_tree_tag_clear(&page->mapping->page_tree,
5113 PAGECACHE_TAG_DIRTY);
5115 spin_unlock_irq(&page->mapping->tree_lock);
5116 ClearPageError(page);
5119 WARN_ON(atomic_read(&eb->refs) == 0);
5122 int set_extent_buffer_dirty(struct extent_buffer *eb)
5125 unsigned long num_pages;
5128 check_buffer_tree_ref(eb);
5130 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5132 num_pages = num_extent_pages(eb->start, eb->len);
5133 WARN_ON(atomic_read(&eb->refs) == 0);
5134 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5136 for (i = 0; i < num_pages; i++)
5137 set_page_dirty(eb->pages[i]);
5141 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5145 unsigned long num_pages;
5147 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5148 num_pages = num_extent_pages(eb->start, eb->len);
5149 for (i = 0; i < num_pages; i++) {
5150 page = eb->pages[i];
5152 ClearPageUptodate(page);
5156 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5160 unsigned long num_pages;
5162 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5163 num_pages = num_extent_pages(eb->start, eb->len);
5164 for (i = 0; i < num_pages; i++) {
5165 page = eb->pages[i];
5166 SetPageUptodate(page);
5170 int extent_buffer_uptodate(struct extent_buffer *eb)
5172 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5175 int read_extent_buffer_pages(struct extent_io_tree *tree,
5176 struct extent_buffer *eb, u64 start, int wait,
5177 get_extent_t *get_extent, int mirror_num)
5180 unsigned long start_i;
5184 int locked_pages = 0;
5185 int all_uptodate = 1;
5186 unsigned long num_pages;
5187 unsigned long num_reads = 0;
5188 struct bio *bio = NULL;
5189 unsigned long bio_flags = 0;
5191 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5195 WARN_ON(start < eb->start);
5196 start_i = (start >> PAGE_SHIFT) -
5197 (eb->start >> PAGE_SHIFT);
5202 num_pages = num_extent_pages(eb->start, eb->len);
5203 for (i = start_i; i < num_pages; i++) {
5204 page = eb->pages[i];
5205 if (wait == WAIT_NONE) {
5206 if (!trylock_page(page))
5212 if (!PageUptodate(page)) {
5219 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5223 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5224 eb->read_mirror = 0;
5225 atomic_set(&eb->io_pages, num_reads);
5226 for (i = start_i; i < num_pages; i++) {
5227 page = eb->pages[i];
5229 if (!PageUptodate(page)) {
5231 atomic_dec(&eb->io_pages);
5236 ClearPageError(page);
5237 err = __extent_read_full_page(tree, page,
5239 mirror_num, &bio_flags,
5244 * We use &bio in above __extent_read_full_page,
5245 * so we ensure that if it returns error, the
5246 * current page fails to add itself to bio and
5247 * it's been unlocked.
5249 * We must dec io_pages by ourselves.
5251 atomic_dec(&eb->io_pages);
5259 err = submit_one_bio(bio, mirror_num, bio_flags);
5264 if (ret || wait != WAIT_COMPLETE)
5267 for (i = start_i; i < num_pages; i++) {
5268 page = eb->pages[i];
5269 wait_on_page_locked(page);
5270 if (!PageUptodate(page))
5278 while (locked_pages > 0) {
5279 page = eb->pages[i];
5287 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
5288 unsigned long start,
5295 char *dst = (char *)dstv;
5296 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5297 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5299 WARN_ON(start > eb->len);
5300 WARN_ON(start + len > eb->start + eb->len);
5302 offset = (start_offset + start) & (PAGE_SIZE - 1);
5305 page = eb->pages[i];
5307 cur = min(len, (PAGE_SIZE - offset));
5308 kaddr = page_address(page);
5309 memcpy(dst, kaddr + offset, cur);
5318 int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv,
5319 unsigned long start,
5326 char __user *dst = (char __user *)dstv;
5327 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5328 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5331 WARN_ON(start > eb->len);
5332 WARN_ON(start + len > eb->start + eb->len);
5334 offset = (start_offset + start) & (PAGE_SIZE - 1);
5337 page = eb->pages[i];
5339 cur = min(len, (PAGE_SIZE - offset));
5340 kaddr = page_address(page);
5341 if (copy_to_user(dst, kaddr + offset, cur)) {
5356 * return 0 if the item is found within a page.
5357 * return 1 if the item spans two pages.
5358 * return -EINVAL otherwise.
5360 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
5361 unsigned long min_len, char **map,
5362 unsigned long *map_start,
5363 unsigned long *map_len)
5365 size_t offset = start & (PAGE_SIZE - 1);
5368 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5369 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5370 unsigned long end_i = (start_offset + start + min_len - 1) >>
5377 offset = start_offset;
5381 *map_start = ((u64)i << PAGE_SHIFT) - start_offset;
5384 if (start + min_len > eb->len) {
5385 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
5387 eb->start, eb->len, start, min_len);
5392 kaddr = page_address(p);
5393 *map = kaddr + offset;
5394 *map_len = PAGE_SIZE - offset;
5398 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
5399 unsigned long start,
5406 char *ptr = (char *)ptrv;
5407 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5408 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5411 WARN_ON(start > eb->len);
5412 WARN_ON(start + len > eb->start + eb->len);
5414 offset = (start_offset + start) & (PAGE_SIZE - 1);
5417 page = eb->pages[i];
5419 cur = min(len, (PAGE_SIZE - offset));
5421 kaddr = page_address(page);
5422 ret = memcmp(ptr, kaddr + offset, cur);
5434 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
5435 unsigned long start, unsigned long len)
5441 char *src = (char *)srcv;
5442 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5443 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5445 WARN_ON(start > eb->len);
5446 WARN_ON(start + len > eb->start + eb->len);
5448 offset = (start_offset + start) & (PAGE_SIZE - 1);
5451 page = eb->pages[i];
5452 WARN_ON(!PageUptodate(page));
5454 cur = min(len, PAGE_SIZE - offset);
5455 kaddr = page_address(page);
5456 memcpy(kaddr + offset, src, cur);
5465 void memset_extent_buffer(struct extent_buffer *eb, char c,
5466 unsigned long start, unsigned long len)
5472 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5473 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5475 WARN_ON(start > eb->len);
5476 WARN_ON(start + len > eb->start + eb->len);
5478 offset = (start_offset + start) & (PAGE_SIZE - 1);
5481 page = eb->pages[i];
5482 WARN_ON(!PageUptodate(page));
5484 cur = min(len, PAGE_SIZE - offset);
5485 kaddr = page_address(page);
5486 memset(kaddr + offset, c, cur);
5494 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5495 unsigned long dst_offset, unsigned long src_offset,
5498 u64 dst_len = dst->len;
5503 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5504 unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
5506 WARN_ON(src->len != dst_len);
5508 offset = (start_offset + dst_offset) &
5512 page = dst->pages[i];
5513 WARN_ON(!PageUptodate(page));
5515 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5517 kaddr = page_address(page);
5518 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5528 * The extent buffer bitmap operations are done with byte granularity because
5529 * bitmap items are not guaranteed to be aligned to a word and therefore a
5530 * single word in a bitmap may straddle two pages in the extent buffer.
5532 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
5533 #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
5534 #define BITMAP_FIRST_BYTE_MASK(start) \
5535 ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
5536 #define BITMAP_LAST_BYTE_MASK(nbits) \
5537 (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
5540 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5542 * @eb: the extent buffer
5543 * @start: offset of the bitmap item in the extent buffer
5545 * @page_index: return index of the page in the extent buffer that contains the
5547 * @page_offset: return offset into the page given by page_index
5549 * This helper hides the ugliness of finding the byte in an extent buffer which
5550 * contains a given bit.
5552 static inline void eb_bitmap_offset(struct extent_buffer *eb,
5553 unsigned long start, unsigned long nr,
5554 unsigned long *page_index,
5555 size_t *page_offset)
5557 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5558 size_t byte_offset = BIT_BYTE(nr);
5562 * The byte we want is the offset of the extent buffer + the offset of
5563 * the bitmap item in the extent buffer + the offset of the byte in the
5566 offset = start_offset + start + byte_offset;
5568 *page_index = offset >> PAGE_SHIFT;
5569 *page_offset = offset & (PAGE_SIZE - 1);
5573 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5574 * @eb: the extent buffer
5575 * @start: offset of the bitmap item in the extent buffer
5576 * @nr: bit number to test
5578 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
5586 eb_bitmap_offset(eb, start, nr, &i, &offset);
5587 page = eb->pages[i];
5588 WARN_ON(!PageUptodate(page));
5589 kaddr = page_address(page);
5590 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5594 * extent_buffer_bitmap_set - set an area of a bitmap
5595 * @eb: the extent buffer
5596 * @start: offset of the bitmap item in the extent buffer
5597 * @pos: bit number of the first bit
5598 * @len: number of bits to set
5600 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
5601 unsigned long pos, unsigned long len)
5607 const unsigned int size = pos + len;
5608 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5609 unsigned int mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5611 eb_bitmap_offset(eb, start, pos, &i, &offset);
5612 page = eb->pages[i];
5613 WARN_ON(!PageUptodate(page));
5614 kaddr = page_address(page);
5616 while (len >= bits_to_set) {
5617 kaddr[offset] |= mask_to_set;
5619 bits_to_set = BITS_PER_BYTE;
5621 if (++offset >= PAGE_SIZE && len > 0) {
5623 page = eb->pages[++i];
5624 WARN_ON(!PageUptodate(page));
5625 kaddr = page_address(page);
5629 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5630 kaddr[offset] |= mask_to_set;
5636 * extent_buffer_bitmap_clear - clear an area of a bitmap
5637 * @eb: the extent buffer
5638 * @start: offset of the bitmap item in the extent buffer
5639 * @pos: bit number of the first bit
5640 * @len: number of bits to clear
5642 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
5643 unsigned long pos, unsigned long len)
5649 const unsigned int size = pos + len;
5650 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5651 unsigned int mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5653 eb_bitmap_offset(eb, start, pos, &i, &offset);
5654 page = eb->pages[i];
5655 WARN_ON(!PageUptodate(page));
5656 kaddr = page_address(page);
5658 while (len >= bits_to_clear) {
5659 kaddr[offset] &= ~mask_to_clear;
5660 len -= bits_to_clear;
5661 bits_to_clear = BITS_PER_BYTE;
5662 mask_to_clear = ~0U;
5663 if (++offset >= PAGE_SIZE && len > 0) {
5665 page = eb->pages[++i];
5666 WARN_ON(!PageUptodate(page));
5667 kaddr = page_address(page);
5671 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5672 kaddr[offset] &= ~mask_to_clear;
5676 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5678 unsigned long distance = (src > dst) ? src - dst : dst - src;
5679 return distance < len;
5682 static void copy_pages(struct page *dst_page, struct page *src_page,
5683 unsigned long dst_off, unsigned long src_off,
5686 char *dst_kaddr = page_address(dst_page);
5688 int must_memmove = 0;
5690 if (dst_page != src_page) {
5691 src_kaddr = page_address(src_page);
5693 src_kaddr = dst_kaddr;
5694 if (areas_overlap(src_off, dst_off, len))
5699 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5701 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5704 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5705 unsigned long src_offset, unsigned long len)
5708 size_t dst_off_in_page;
5709 size_t src_off_in_page;
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,
5716 "memmove bogus src_offset %lu move "
5717 "len %lu dst len %lu", src_offset, len, dst->len);
5720 if (dst_offset + len > dst->len) {
5721 btrfs_err(dst->fs_info,
5722 "memmove bogus dst_offset %lu move "
5723 "len %lu dst len %lu", dst_offset, len, dst->len);
5728 dst_off_in_page = (start_offset + dst_offset) &
5730 src_off_in_page = (start_offset + src_offset) &
5733 dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
5734 src_i = (start_offset + src_offset) >> PAGE_SHIFT;
5736 cur = min(len, (unsigned long)(PAGE_SIZE -
5738 cur = min_t(unsigned long, cur,
5739 (unsigned long)(PAGE_SIZE - dst_off_in_page));
5741 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5742 dst_off_in_page, src_off_in_page, cur);
5750 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5751 unsigned long src_offset, unsigned long len)
5754 size_t dst_off_in_page;
5755 size_t src_off_in_page;
5756 unsigned long dst_end = dst_offset + len - 1;
5757 unsigned long src_end = src_offset + len - 1;
5758 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5759 unsigned long dst_i;
5760 unsigned long src_i;
5762 if (src_offset + len > dst->len) {
5763 btrfs_err(dst->fs_info, "memmove bogus src_offset %lu move "
5764 "len %lu len %lu", src_offset, len, dst->len);
5767 if (dst_offset + len > dst->len) {
5768 btrfs_err(dst->fs_info, "memmove bogus dst_offset %lu move "
5769 "len %lu len %lu", dst_offset, len, dst->len);
5772 if (dst_offset < src_offset) {
5773 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5777 dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
5778 src_i = (start_offset + src_end) >> PAGE_SHIFT;
5780 dst_off_in_page = (start_offset + dst_end) &
5782 src_off_in_page = (start_offset + src_end) &
5785 cur = min_t(unsigned long, len, src_off_in_page + 1);
5786 cur = min(cur, dst_off_in_page + 1);
5787 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5788 dst_off_in_page - cur + 1,
5789 src_off_in_page - cur + 1, cur);
5797 int try_release_extent_buffer(struct page *page)
5799 struct extent_buffer *eb;
5802 * We need to make sure nobody is attaching this page to an eb right
5805 spin_lock(&page->mapping->private_lock);
5806 if (!PagePrivate(page)) {
5807 spin_unlock(&page->mapping->private_lock);
5811 eb = (struct extent_buffer *)page->private;
5815 * This is a little awful but should be ok, we need to make sure that
5816 * the eb doesn't disappear out from under us while we're looking at
5819 spin_lock(&eb->refs_lock);
5820 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5821 spin_unlock(&eb->refs_lock);
5822 spin_unlock(&page->mapping->private_lock);
5825 spin_unlock(&page->mapping->private_lock);
5828 * If tree ref isn't set then we know the ref on this eb is a real ref,
5829 * so just return, this page will likely be freed soon anyway.
5831 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5832 spin_unlock(&eb->refs_lock);
5836 return release_extent_buffer(eb);