1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/spinlock.h>
8 #include <linux/blkdev.h>
9 #include <linux/swap.h>
10 #include <linux/writeback.h>
11 #include <linux/pagevec.h>
12 #include <linux/prefetch.h>
13 #include <linux/cleancache.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
17 #include "btrfs_inode.h"
19 #include "check-integrity.h"
21 #include "rcu-string.h"
23 #include "transaction.h"
25 static struct kmem_cache *extent_state_cache;
26 static struct kmem_cache *extent_buffer_cache;
27 static struct bio_set *btrfs_bioset;
29 static inline bool extent_state_in_tree(const struct extent_state *state)
31 return !RB_EMPTY_NODE(&state->rb_node);
34 #ifdef CONFIG_BTRFS_DEBUG
35 static LIST_HEAD(buffers);
36 static LIST_HEAD(states);
38 static DEFINE_SPINLOCK(leak_lock);
41 void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
45 spin_lock_irqsave(&leak_lock, flags);
47 spin_unlock_irqrestore(&leak_lock, flags);
51 void btrfs_leak_debug_del(struct list_head *entry)
55 spin_lock_irqsave(&leak_lock, flags);
57 spin_unlock_irqrestore(&leak_lock, flags);
61 void btrfs_leak_debug_check(void)
63 struct extent_state *state;
64 struct extent_buffer *eb;
66 while (!list_empty(&states)) {
67 state = list_entry(states.next, struct extent_state, leak_list);
68 pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
69 state->start, state->end, state->state,
70 extent_state_in_tree(state),
71 atomic_read(&state->refs));
72 list_del(&state->leak_list);
73 kmem_cache_free(extent_state_cache, state);
76 while (!list_empty(&buffers)) {
77 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
78 printk(KERN_ERR "BTRFS: buffer leak start %llu len %lu "
80 eb->start, eb->len, atomic_read(&eb->refs));
81 list_del(&eb->leak_list);
82 kmem_cache_free(extent_buffer_cache, eb);
86 #define btrfs_debug_check_extent_io_range(tree, start, end) \
87 __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
88 static inline void __btrfs_debug_check_extent_io_range(const char *caller,
89 struct extent_io_tree *tree, u64 start, u64 end)
97 inode = tree->mapping->host;
98 isize = i_size_read(inode);
99 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
100 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
101 "%s: ino %llu isize %llu odd range [%llu,%llu]",
102 caller, btrfs_ino(inode), isize, start, end);
106 #define btrfs_leak_debug_add(new, head) do {} while (0)
107 #define btrfs_leak_debug_del(entry) do {} while (0)
108 #define btrfs_leak_debug_check() do {} while (0)
109 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
112 #define BUFFER_LRU_MAX 64
117 struct rb_node rb_node;
120 struct extent_page_data {
122 struct extent_io_tree *tree;
123 get_extent_t *get_extent;
124 unsigned long bio_flags;
126 /* tells writepage not to lock the state bits for this range
127 * it still does the unlocking
129 unsigned int extent_locked:1;
131 /* tells the submit_bio code to use a WRITE_SYNC */
132 unsigned int sync_io:1;
135 static void add_extent_changeset(struct extent_state *state, unsigned bits,
136 struct extent_changeset *changeset,
143 if (set && (state->state & bits) == bits)
145 if (!set && (state->state & bits) == 0)
147 changeset->bytes_changed += state->end - state->start + 1;
148 ret = ulist_add(changeset->range_changed, state->start, state->end,
154 static noinline void flush_write_bio(void *data);
155 static inline struct btrfs_fs_info *
156 tree_fs_info(struct extent_io_tree *tree)
160 return btrfs_sb(tree->mapping->host->i_sb);
163 int __init extent_io_init(void)
165 extent_state_cache = kmem_cache_create("btrfs_extent_state",
166 sizeof(struct extent_state), 0,
167 SLAB_MEM_SPREAD, NULL);
168 if (!extent_state_cache)
171 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
172 sizeof(struct extent_buffer), 0,
173 SLAB_MEM_SPREAD, NULL);
174 if (!extent_buffer_cache)
175 goto free_state_cache;
177 btrfs_bioset = bioset_create(BIO_POOL_SIZE,
178 offsetof(struct btrfs_io_bio, bio));
180 goto free_buffer_cache;
182 if (bioset_integrity_create(btrfs_bioset, BIO_POOL_SIZE))
188 bioset_free(btrfs_bioset);
192 kmem_cache_destroy(extent_buffer_cache);
193 extent_buffer_cache = NULL;
196 kmem_cache_destroy(extent_state_cache);
197 extent_state_cache = NULL;
201 void extent_io_exit(void)
203 btrfs_leak_debug_check();
206 * Make sure all delayed rcu free are flushed before we
210 kmem_cache_destroy(extent_state_cache);
211 kmem_cache_destroy(extent_buffer_cache);
213 bioset_free(btrfs_bioset);
216 void extent_io_tree_init(struct extent_io_tree *tree,
217 struct address_space *mapping)
219 tree->state = RB_ROOT;
221 tree->dirty_bytes = 0;
222 spin_lock_init(&tree->lock);
223 tree->mapping = mapping;
226 static struct extent_state *alloc_extent_state(gfp_t mask)
228 struct extent_state *state;
230 state = kmem_cache_alloc(extent_state_cache, mask);
234 state->failrec = NULL;
235 RB_CLEAR_NODE(&state->rb_node);
236 btrfs_leak_debug_add(&state->leak_list, &states);
237 atomic_set(&state->refs, 1);
238 init_waitqueue_head(&state->wq);
239 trace_alloc_extent_state(state, mask, _RET_IP_);
243 void free_extent_state(struct extent_state *state)
247 if (atomic_dec_and_test(&state->refs)) {
248 WARN_ON(extent_state_in_tree(state));
249 btrfs_leak_debug_del(&state->leak_list);
250 trace_free_extent_state(state, _RET_IP_);
251 kmem_cache_free(extent_state_cache, state);
255 static struct rb_node *tree_insert(struct rb_root *root,
256 struct rb_node *search_start,
258 struct rb_node *node,
259 struct rb_node ***p_in,
260 struct rb_node **parent_in)
263 struct rb_node *parent = NULL;
264 struct tree_entry *entry;
266 if (p_in && parent_in) {
272 p = search_start ? &search_start : &root->rb_node;
275 entry = rb_entry(parent, struct tree_entry, rb_node);
277 if (offset < entry->start)
279 else if (offset > entry->end)
286 rb_link_node(node, parent, p);
287 rb_insert_color(node, root);
291 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
292 struct rb_node **prev_ret,
293 struct rb_node **next_ret,
294 struct rb_node ***p_ret,
295 struct rb_node **parent_ret)
297 struct rb_root *root = &tree->state;
298 struct rb_node **n = &root->rb_node;
299 struct rb_node *prev = NULL;
300 struct rb_node *orig_prev = NULL;
301 struct tree_entry *entry;
302 struct tree_entry *prev_entry = NULL;
306 entry = rb_entry(prev, struct tree_entry, rb_node);
309 if (offset < entry->start)
311 else if (offset > entry->end)
324 while (prev && offset > prev_entry->end) {
325 prev = rb_next(prev);
326 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
333 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
334 while (prev && offset < prev_entry->start) {
335 prev = rb_prev(prev);
336 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
343 static inline struct rb_node *
344 tree_search_for_insert(struct extent_io_tree *tree,
346 struct rb_node ***p_ret,
347 struct rb_node **parent_ret)
349 struct rb_node *prev = NULL;
352 ret = __etree_search(tree, offset, &prev, NULL, p_ret, parent_ret);
358 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
361 return tree_search_for_insert(tree, offset, NULL, NULL);
364 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
365 struct extent_state *other)
367 if (tree->ops && tree->ops->merge_extent_hook)
368 tree->ops->merge_extent_hook(tree->mapping->host, new,
373 * utility function to look for merge candidates inside a given range.
374 * Any extents with matching state are merged together into a single
375 * extent in the tree. Extents with EXTENT_IO in their state field
376 * are not merged because the end_io handlers need to be able to do
377 * operations on them without sleeping (or doing allocations/splits).
379 * This should be called with the tree lock held.
381 static void merge_state(struct extent_io_tree *tree,
382 struct extent_state *state)
384 struct extent_state *other;
385 struct rb_node *other_node;
387 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
390 other_node = rb_prev(&state->rb_node);
392 other = rb_entry(other_node, struct extent_state, rb_node);
393 if (other->end == state->start - 1 &&
394 other->state == state->state) {
395 merge_cb(tree, state, other);
396 state->start = other->start;
397 rb_erase(&other->rb_node, &tree->state);
398 RB_CLEAR_NODE(&other->rb_node);
399 free_extent_state(other);
402 other_node = rb_next(&state->rb_node);
404 other = rb_entry(other_node, struct extent_state, rb_node);
405 if (other->start == state->end + 1 &&
406 other->state == state->state) {
407 merge_cb(tree, state, other);
408 state->end = other->end;
409 rb_erase(&other->rb_node, &tree->state);
410 RB_CLEAR_NODE(&other->rb_node);
411 free_extent_state(other);
416 static void set_state_cb(struct extent_io_tree *tree,
417 struct extent_state *state, unsigned *bits)
419 if (tree->ops && tree->ops->set_bit_hook)
420 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
423 static void clear_state_cb(struct extent_io_tree *tree,
424 struct extent_state *state, unsigned *bits)
426 if (tree->ops && tree->ops->clear_bit_hook)
427 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
430 static void set_state_bits(struct extent_io_tree *tree,
431 struct extent_state *state, unsigned *bits,
432 struct extent_changeset *changeset);
435 * insert an extent_state struct into the tree. 'bits' are set on the
436 * struct before it is inserted.
438 * This may return -EEXIST if the extent is already there, in which case the
439 * state struct is freed.
441 * The tree lock is not taken internally. This is a utility function and
442 * probably isn't what you want to call (see set/clear_extent_bit).
444 static int insert_state(struct extent_io_tree *tree,
445 struct extent_state *state, u64 start, u64 end,
447 struct rb_node **parent,
448 unsigned *bits, struct extent_changeset *changeset)
450 struct rb_node *node;
453 WARN(1, KERN_ERR "BTRFS: end < start %llu %llu\n",
455 state->start = start;
458 set_state_bits(tree, state, bits, changeset);
460 node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
462 struct extent_state *found;
463 found = rb_entry(node, struct extent_state, rb_node);
464 printk(KERN_ERR "BTRFS: found node %llu %llu on insert of "
466 found->start, found->end, start, end);
469 merge_state(tree, state);
473 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
476 if (tree->ops && tree->ops->split_extent_hook)
477 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
481 * split a given extent state struct in two, inserting the preallocated
482 * struct 'prealloc' as the newly created second half. 'split' indicates an
483 * offset inside 'orig' where it should be split.
486 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
487 * are two extent state structs in the tree:
488 * prealloc: [orig->start, split - 1]
489 * orig: [ split, orig->end ]
491 * The tree locks are not taken by this function. They need to be held
494 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
495 struct extent_state *prealloc, u64 split)
497 struct rb_node *node;
499 split_cb(tree, orig, split);
501 prealloc->start = orig->start;
502 prealloc->end = split - 1;
503 prealloc->state = orig->state;
506 node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
507 &prealloc->rb_node, NULL, NULL);
509 free_extent_state(prealloc);
515 static struct extent_state *next_state(struct extent_state *state)
517 struct rb_node *next = rb_next(&state->rb_node);
519 return rb_entry(next, struct extent_state, rb_node);
525 * utility function to clear some bits in an extent state struct.
526 * it will optionally wake up any one waiting on this state (wake == 1).
528 * If no bits are set on the state struct after clearing things, the
529 * struct is freed and removed from the tree
531 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
532 struct extent_state *state,
533 unsigned *bits, int wake,
534 struct extent_changeset *changeset)
536 struct extent_state *next;
537 unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
539 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
540 u64 range = state->end - state->start + 1;
541 WARN_ON(range > tree->dirty_bytes);
542 tree->dirty_bytes -= range;
544 clear_state_cb(tree, state, bits);
545 add_extent_changeset(state, bits_to_clear, changeset, 0);
546 state->state &= ~bits_to_clear;
549 if (state->state == 0) {
550 next = next_state(state);
551 if (extent_state_in_tree(state)) {
552 rb_erase(&state->rb_node, &tree->state);
553 RB_CLEAR_NODE(&state->rb_node);
554 free_extent_state(state);
559 merge_state(tree, state);
560 next = next_state(state);
565 static struct extent_state *
566 alloc_extent_state_atomic(struct extent_state *prealloc)
569 prealloc = alloc_extent_state(GFP_ATOMIC);
574 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
576 btrfs_panic(tree_fs_info(tree), err, "Locking error: "
577 "Extent tree was modified by another "
578 "thread while locked.");
582 * clear some bits on a range in the tree. This may require splitting
583 * or inserting elements in the tree, so the gfp mask is used to
584 * indicate which allocations or sleeping are allowed.
586 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
587 * the given range from the tree regardless of state (ie for truncate).
589 * the range [start, end] is inclusive.
591 * This takes the tree lock, and returns 0 on success and < 0 on error.
593 static int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
594 unsigned bits, int wake, int delete,
595 struct extent_state **cached_state,
596 gfp_t mask, struct extent_changeset *changeset)
598 struct extent_state *state;
599 struct extent_state *cached;
600 struct extent_state *prealloc = NULL;
601 struct rb_node *node;
606 btrfs_debug_check_extent_io_range(tree, start, end);
608 if (bits & EXTENT_DELALLOC)
609 bits |= EXTENT_NORESERVE;
612 bits |= ~EXTENT_CTLBITS;
613 bits |= EXTENT_FIRST_DELALLOC;
615 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
618 if (!prealloc && gfpflags_allow_blocking(mask)) {
620 * Don't care for allocation failure here because we might end
621 * up not needing the pre-allocated extent state at all, which
622 * is the case if we only have in the tree extent states that
623 * cover our input range and don't cover too any other range.
624 * If we end up needing a new extent state we allocate it later.
626 prealloc = alloc_extent_state(mask);
629 spin_lock(&tree->lock);
631 cached = *cached_state;
634 *cached_state = NULL;
638 if (cached && extent_state_in_tree(cached) &&
639 cached->start <= start && cached->end > start) {
641 atomic_dec(&cached->refs);
646 free_extent_state(cached);
649 * this search will find the extents that end after
652 node = tree_search(tree, start);
655 state = rb_entry(node, struct extent_state, rb_node);
657 if (state->start > end)
659 WARN_ON(state->end < start);
660 last_end = state->end;
662 /* the state doesn't have the wanted bits, go ahead */
663 if (!(state->state & bits)) {
664 state = next_state(state);
669 * | ---- desired range ---- |
671 * | ------------- state -------------- |
673 * We need to split the extent we found, and may flip
674 * bits on second half.
676 * If the extent we found extends past our range, we
677 * just split and search again. It'll get split again
678 * the next time though.
680 * If the extent we found is inside our range, we clear
681 * the desired bit on it.
684 if (state->start < start) {
685 prealloc = alloc_extent_state_atomic(prealloc);
687 err = split_state(tree, state, prealloc, start);
689 extent_io_tree_panic(tree, err);
694 if (state->end <= end) {
695 state = clear_state_bit(tree, state, &bits, wake,
702 * | ---- desired range ---- |
704 * We need to split the extent, and clear the bit
707 if (state->start <= end && state->end > end) {
708 prealloc = alloc_extent_state_atomic(prealloc);
710 err = split_state(tree, state, prealloc, end + 1);
712 extent_io_tree_panic(tree, err);
717 clear_state_bit(tree, prealloc, &bits, wake, changeset);
723 state = clear_state_bit(tree, state, &bits, wake, changeset);
725 if (last_end == (u64)-1)
727 start = last_end + 1;
728 if (start <= end && state && !need_resched())
734 spin_unlock(&tree->lock);
735 if (gfpflags_allow_blocking(mask))
740 spin_unlock(&tree->lock);
742 free_extent_state(prealloc);
748 static void wait_on_state(struct extent_io_tree *tree,
749 struct extent_state *state)
750 __releases(tree->lock)
751 __acquires(tree->lock)
754 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
755 spin_unlock(&tree->lock);
757 spin_lock(&tree->lock);
758 finish_wait(&state->wq, &wait);
762 * waits for one or more bits to clear on a range in the state tree.
763 * The range [start, end] is inclusive.
764 * The tree lock is taken by this function
766 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
769 struct extent_state *state;
770 struct rb_node *node;
772 btrfs_debug_check_extent_io_range(tree, start, end);
774 spin_lock(&tree->lock);
778 * this search will find all the extents that end after
781 node = tree_search(tree, start);
786 state = rb_entry(node, struct extent_state, rb_node);
788 if (state->start > end)
791 if (state->state & bits) {
792 start = state->start;
793 atomic_inc(&state->refs);
794 wait_on_state(tree, state);
795 free_extent_state(state);
798 start = state->end + 1;
803 if (!cond_resched_lock(&tree->lock)) {
804 node = rb_next(node);
809 spin_unlock(&tree->lock);
812 static void set_state_bits(struct extent_io_tree *tree,
813 struct extent_state *state,
814 unsigned *bits, struct extent_changeset *changeset)
816 unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
818 set_state_cb(tree, state, bits);
819 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
820 u64 range = state->end - state->start + 1;
821 tree->dirty_bytes += range;
823 add_extent_changeset(state, bits_to_set, changeset, 1);
824 state->state |= bits_to_set;
827 static void cache_state_if_flags(struct extent_state *state,
828 struct extent_state **cached_ptr,
831 if (cached_ptr && !(*cached_ptr)) {
832 if (!flags || (state->state & flags)) {
834 atomic_inc(&state->refs);
839 static void cache_state(struct extent_state *state,
840 struct extent_state **cached_ptr)
842 return cache_state_if_flags(state, cached_ptr,
843 EXTENT_IOBITS | EXTENT_BOUNDARY);
847 * set some bits on a range in the tree. This may require allocations or
848 * sleeping, so the gfp mask is used to indicate what is allowed.
850 * If any of the exclusive bits are set, this will fail with -EEXIST if some
851 * part of the range already has the desired bits set. The start of the
852 * existing range is returned in failed_start in this case.
854 * [start, end] is inclusive This takes the tree lock.
857 static int __must_check
858 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
859 unsigned bits, unsigned exclusive_bits,
860 u64 *failed_start, struct extent_state **cached_state,
861 gfp_t mask, struct extent_changeset *changeset)
863 struct extent_state *state;
864 struct extent_state *prealloc = NULL;
865 struct rb_node *node;
867 struct rb_node *parent;
872 btrfs_debug_check_extent_io_range(tree, start, end);
874 bits |= EXTENT_FIRST_DELALLOC;
876 if (!prealloc && gfpflags_allow_blocking(mask)) {
878 * Don't care for allocation failure here because we might end
879 * up not needing the pre-allocated extent state at all, which
880 * is the case if we only have in the tree extent states that
881 * cover our input range and don't cover too any other range.
882 * If we end up needing a new extent state we allocate it later.
884 prealloc = alloc_extent_state(mask);
887 spin_lock(&tree->lock);
888 if (cached_state && *cached_state) {
889 state = *cached_state;
890 if (state->start <= start && state->end > start &&
891 extent_state_in_tree(state)) {
892 node = &state->rb_node;
897 * this search will find all the extents that end after
900 node = tree_search_for_insert(tree, start, &p, &parent);
902 prealloc = alloc_extent_state_atomic(prealloc);
904 err = insert_state(tree, prealloc, start, end,
905 &p, &parent, &bits, changeset);
907 extent_io_tree_panic(tree, err);
909 cache_state(prealloc, cached_state);
913 state = rb_entry(node, struct extent_state, rb_node);
915 last_start = state->start;
916 last_end = state->end;
919 * | ---- desired range ---- |
922 * Just lock what we found and keep going
924 if (state->start == start && state->end <= end) {
925 if (state->state & exclusive_bits) {
926 *failed_start = state->start;
931 set_state_bits(tree, state, &bits, changeset);
932 cache_state(state, cached_state);
933 merge_state(tree, state);
934 if (last_end == (u64)-1)
936 start = last_end + 1;
937 state = next_state(state);
938 if (start < end && state && state->start == start &&
945 * | ---- desired range ---- |
948 * | ------------- state -------------- |
950 * We need to split the extent we found, and may flip bits on
953 * If the extent we found extends past our
954 * range, we just split and search again. It'll get split
955 * again the next time though.
957 * If the extent we found is inside our range, we set the
960 if (state->start < start) {
961 if (state->state & exclusive_bits) {
962 *failed_start = start;
967 prealloc = alloc_extent_state_atomic(prealloc);
969 err = split_state(tree, state, prealloc, start);
971 extent_io_tree_panic(tree, err);
976 if (state->end <= end) {
977 set_state_bits(tree, state, &bits, changeset);
978 cache_state(state, cached_state);
979 merge_state(tree, state);
980 if (last_end == (u64)-1)
982 start = last_end + 1;
983 state = next_state(state);
984 if (start < end && state && state->start == start &&
991 * | ---- desired range ---- |
992 * | state | or | state |
994 * There's a hole, we need to insert something in it and
995 * ignore the extent we found.
997 if (state->start > start) {
999 if (end < last_start)
1002 this_end = last_start - 1;
1004 prealloc = alloc_extent_state_atomic(prealloc);
1008 * Avoid to free 'prealloc' if it can be merged with
1011 err = insert_state(tree, prealloc, start, this_end,
1012 NULL, NULL, &bits, changeset);
1014 extent_io_tree_panic(tree, err);
1016 cache_state(prealloc, cached_state);
1018 start = this_end + 1;
1022 * | ---- desired range ---- |
1024 * We need to split the extent, and set the bit
1027 if (state->start <= end && state->end > end) {
1028 if (state->state & exclusive_bits) {
1029 *failed_start = start;
1034 prealloc = alloc_extent_state_atomic(prealloc);
1036 err = split_state(tree, state, prealloc, end + 1);
1038 extent_io_tree_panic(tree, err);
1040 set_state_bits(tree, prealloc, &bits, changeset);
1041 cache_state(prealloc, cached_state);
1042 merge_state(tree, prealloc);
1050 spin_unlock(&tree->lock);
1051 if (gfpflags_allow_blocking(mask))
1056 spin_unlock(&tree->lock);
1058 free_extent_state(prealloc);
1064 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1065 unsigned bits, u64 * failed_start,
1066 struct extent_state **cached_state, gfp_t mask)
1068 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
1069 cached_state, mask, NULL);
1074 * convert_extent_bit - convert all bits in a given range from one bit to
1076 * @tree: the io tree to search
1077 * @start: the start offset in bytes
1078 * @end: the end offset in bytes (inclusive)
1079 * @bits: the bits to set in this range
1080 * @clear_bits: the bits to clear in this range
1081 * @cached_state: state that we're going to cache
1083 * This will go through and set bits for the given range. If any states exist
1084 * already in this range they are set with the given bit and cleared of the
1085 * clear_bits. This is only meant to be used by things that are mergeable, ie
1086 * converting from say DELALLOC to DIRTY. This is not meant to be used with
1087 * boundary bits like LOCK.
1089 * All allocations are done with GFP_NOFS.
1091 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1092 unsigned bits, unsigned clear_bits,
1093 struct extent_state **cached_state)
1095 struct extent_state *state;
1096 struct extent_state *prealloc = NULL;
1097 struct rb_node *node;
1099 struct rb_node *parent;
1103 bool first_iteration = true;
1105 btrfs_debug_check_extent_io_range(tree, start, end);
1110 * Best effort, don't worry if extent state allocation fails
1111 * here for the first iteration. We might have a cached state
1112 * that matches exactly the target range, in which case no
1113 * extent state allocations are needed. We'll only know this
1114 * after locking the tree.
1116 prealloc = alloc_extent_state(GFP_NOFS);
1117 if (!prealloc && !first_iteration)
1121 spin_lock(&tree->lock);
1122 if (cached_state && *cached_state) {
1123 state = *cached_state;
1124 if (state->start <= start && state->end > start &&
1125 extent_state_in_tree(state)) {
1126 node = &state->rb_node;
1132 * this search will find all the extents that end after
1135 node = tree_search_for_insert(tree, start, &p, &parent);
1137 prealloc = alloc_extent_state_atomic(prealloc);
1142 err = insert_state(tree, prealloc, start, end,
1143 &p, &parent, &bits, NULL);
1145 extent_io_tree_panic(tree, err);
1146 cache_state(prealloc, cached_state);
1150 state = rb_entry(node, struct extent_state, rb_node);
1152 last_start = state->start;
1153 last_end = state->end;
1156 * | ---- desired range ---- |
1159 * Just lock what we found and keep going
1161 if (state->start == start && state->end <= end) {
1162 set_state_bits(tree, state, &bits, NULL);
1163 cache_state(state, cached_state);
1164 state = clear_state_bit(tree, state, &clear_bits, 0, NULL);
1165 if (last_end == (u64)-1)
1167 start = last_end + 1;
1168 if (start < end && state && state->start == start &&
1175 * | ---- desired range ---- |
1178 * | ------------- state -------------- |
1180 * We need to split the extent we found, and may flip bits on
1183 * If the extent we found extends past our
1184 * range, we just split and search again. It'll get split
1185 * again the next time though.
1187 * If the extent we found is inside our range, we set the
1188 * desired bit on it.
1190 if (state->start < start) {
1191 prealloc = alloc_extent_state_atomic(prealloc);
1196 err = split_state(tree, state, prealloc, start);
1198 extent_io_tree_panic(tree, err);
1202 if (state->end <= end) {
1203 set_state_bits(tree, state, &bits, NULL);
1204 cache_state(state, cached_state);
1205 state = clear_state_bit(tree, state, &clear_bits, 0,
1207 if (last_end == (u64)-1)
1209 start = last_end + 1;
1210 if (start < end && state && state->start == start &&
1217 * | ---- desired range ---- |
1218 * | state | or | state |
1220 * There's a hole, we need to insert something in it and
1221 * ignore the extent we found.
1223 if (state->start > start) {
1225 if (end < last_start)
1228 this_end = last_start - 1;
1230 prealloc = alloc_extent_state_atomic(prealloc);
1237 * Avoid to free 'prealloc' if it can be merged with
1240 err = insert_state(tree, prealloc, start, this_end,
1241 NULL, NULL, &bits, NULL);
1243 extent_io_tree_panic(tree, err);
1244 cache_state(prealloc, cached_state);
1246 start = this_end + 1;
1250 * | ---- desired range ---- |
1252 * We need to split the extent, and set the bit
1255 if (state->start <= end && state->end > end) {
1256 prealloc = alloc_extent_state_atomic(prealloc);
1262 err = split_state(tree, state, prealloc, end + 1);
1264 extent_io_tree_panic(tree, err);
1266 set_state_bits(tree, prealloc, &bits, NULL);
1267 cache_state(prealloc, cached_state);
1268 clear_state_bit(tree, prealloc, &clear_bits, 0, NULL);
1276 spin_unlock(&tree->lock);
1278 first_iteration = false;
1282 spin_unlock(&tree->lock);
1284 free_extent_state(prealloc);
1289 /* wrappers around set/clear extent bit */
1290 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1291 unsigned bits, struct extent_changeset *changeset)
1294 * We don't support EXTENT_LOCKED yet, as current changeset will
1295 * record any bits changed, so for EXTENT_LOCKED case, it will
1296 * either fail with -EEXIST or changeset will record the whole
1299 BUG_ON(bits & EXTENT_LOCKED);
1301 return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
1305 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
1306 unsigned bits, int wake, int delete,
1307 struct extent_state **cached, gfp_t mask)
1309 return __clear_extent_bit(tree, start, end, bits, wake, delete,
1310 cached, mask, NULL);
1313 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1314 unsigned bits, struct extent_changeset *changeset)
1317 * Don't support EXTENT_LOCKED case, same reason as
1318 * set_record_extent_bits().
1320 BUG_ON(bits & EXTENT_LOCKED);
1322 return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
1327 * either insert or lock state struct between start and end use mask to tell
1328 * us if waiting is desired.
1330 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1331 struct extent_state **cached_state)
1337 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
1338 EXTENT_LOCKED, &failed_start,
1339 cached_state, GFP_NOFS, NULL);
1340 if (err == -EEXIST) {
1341 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1342 start = failed_start;
1345 WARN_ON(start > end);
1350 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1355 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1356 &failed_start, NULL, GFP_NOFS, NULL);
1357 if (err == -EEXIST) {
1358 if (failed_start > start)
1359 clear_extent_bit(tree, start, failed_start - 1,
1360 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
1366 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1368 unsigned long index = start >> PAGE_SHIFT;
1369 unsigned long end_index = end >> PAGE_SHIFT;
1372 while (index <= end_index) {
1373 page = find_get_page(inode->i_mapping, index);
1374 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1375 clear_page_dirty_for_io(page);
1381 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1383 unsigned long index = start >> PAGE_SHIFT;
1384 unsigned long end_index = end >> PAGE_SHIFT;
1387 while (index <= end_index) {
1388 page = find_get_page(inode->i_mapping, index);
1389 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1390 __set_page_dirty_nobuffers(page);
1391 account_page_redirty(page);
1398 * helper function to set both pages and extents in the tree writeback
1400 static void set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1402 unsigned long index = start >> PAGE_SHIFT;
1403 unsigned long end_index = end >> PAGE_SHIFT;
1406 while (index <= end_index) {
1407 page = find_get_page(tree->mapping, index);
1408 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1409 set_page_writeback(page);
1415 /* find the first state struct with 'bits' set after 'start', and
1416 * return it. tree->lock must be held. NULL will returned if
1417 * nothing was found after 'start'
1419 static struct extent_state *
1420 find_first_extent_bit_state(struct extent_io_tree *tree,
1421 u64 start, unsigned bits)
1423 struct rb_node *node;
1424 struct extent_state *state;
1427 * this search will find all the extents that end after
1430 node = tree_search(tree, start);
1435 state = rb_entry(node, struct extent_state, rb_node);
1436 if (state->end >= start && (state->state & bits))
1439 node = rb_next(node);
1448 * find the first offset in the io tree with 'bits' set. zero is
1449 * returned if we find something, and *start_ret and *end_ret are
1450 * set to reflect the state struct that was found.
1452 * If nothing was found, 1 is returned. If found something, return 0.
1454 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1455 u64 *start_ret, u64 *end_ret, unsigned bits,
1456 struct extent_state **cached_state)
1458 struct extent_state *state;
1462 spin_lock(&tree->lock);
1463 if (cached_state && *cached_state) {
1464 state = *cached_state;
1465 if (state->end == start - 1 && extent_state_in_tree(state)) {
1466 n = rb_next(&state->rb_node);
1468 state = rb_entry(n, struct extent_state,
1470 if (state->state & bits)
1474 free_extent_state(*cached_state);
1475 *cached_state = NULL;
1478 free_extent_state(*cached_state);
1479 *cached_state = NULL;
1482 state = find_first_extent_bit_state(tree, start, bits);
1485 cache_state_if_flags(state, cached_state, 0);
1486 *start_ret = state->start;
1487 *end_ret = state->end;
1491 spin_unlock(&tree->lock);
1496 * find a contiguous range of bytes in the file marked as delalloc, not
1497 * more than 'max_bytes'. start and end are used to return the range,
1499 * 1 is returned if we find something, 0 if nothing was in the tree
1501 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1502 u64 *start, u64 *end, u64 max_bytes,
1503 struct extent_state **cached_state)
1505 struct rb_node *node;
1506 struct extent_state *state;
1507 u64 cur_start = *start;
1509 u64 total_bytes = 0;
1511 spin_lock(&tree->lock);
1514 * this search will find all the extents that end after
1517 node = tree_search(tree, cur_start);
1525 state = rb_entry(node, struct extent_state, rb_node);
1526 if (found && (state->start != cur_start ||
1527 (state->state & EXTENT_BOUNDARY))) {
1530 if (!(state->state & EXTENT_DELALLOC)) {
1536 *start = state->start;
1537 *cached_state = state;
1538 atomic_inc(&state->refs);
1542 cur_start = state->end + 1;
1543 node = rb_next(node);
1544 total_bytes += state->end - state->start + 1;
1545 if (total_bytes >= max_bytes)
1551 spin_unlock(&tree->lock);
1555 static noinline void __unlock_for_delalloc(struct inode *inode,
1556 struct page *locked_page,
1560 struct page *pages[16];
1561 unsigned long index = start >> PAGE_SHIFT;
1562 unsigned long end_index = end >> PAGE_SHIFT;
1563 unsigned long nr_pages = end_index - index + 1;
1566 if (index == locked_page->index && end_index == index)
1569 while (nr_pages > 0) {
1570 ret = find_get_pages_contig(inode->i_mapping, index,
1571 min_t(unsigned long, nr_pages,
1572 ARRAY_SIZE(pages)), pages);
1573 for (i = 0; i < ret; i++) {
1574 if (pages[i] != locked_page)
1575 unlock_page(pages[i]);
1584 static noinline int lock_delalloc_pages(struct inode *inode,
1585 struct page *locked_page,
1589 unsigned long index = delalloc_start >> PAGE_SHIFT;
1590 unsigned long start_index = index;
1591 unsigned long end_index = delalloc_end >> PAGE_SHIFT;
1592 unsigned long pages_locked = 0;
1593 struct page *pages[16];
1594 unsigned long nrpages;
1598 /* the caller is responsible for locking the start index */
1599 if (index == locked_page->index && index == end_index)
1602 /* skip the page at the start index */
1603 nrpages = end_index - index + 1;
1604 while (nrpages > 0) {
1605 ret = find_get_pages_contig(inode->i_mapping, index,
1606 min_t(unsigned long,
1607 nrpages, ARRAY_SIZE(pages)), pages);
1612 /* now we have an array of pages, lock them all */
1613 for (i = 0; i < ret; i++) {
1615 * the caller is taking responsibility for
1618 if (pages[i] != locked_page) {
1619 lock_page(pages[i]);
1620 if (!PageDirty(pages[i]) ||
1621 pages[i]->mapping != inode->i_mapping) {
1623 unlock_page(pages[i]);
1637 if (ret && pages_locked) {
1638 __unlock_for_delalloc(inode, locked_page,
1640 ((u64)(start_index + pages_locked - 1)) <<
1647 * find a contiguous range of bytes in the file marked as delalloc, not
1648 * more than 'max_bytes'. start and end are used to return the range,
1650 * 1 is returned if we find something, 0 if nothing was in the tree
1652 STATIC u64 find_lock_delalloc_range(struct inode *inode,
1653 struct extent_io_tree *tree,
1654 struct page *locked_page, u64 *start,
1655 u64 *end, u64 max_bytes)
1660 struct extent_state *cached_state = NULL;
1665 /* step one, find a bunch of delalloc bytes starting at start */
1666 delalloc_start = *start;
1668 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1669 max_bytes, &cached_state);
1670 if (!found || delalloc_end <= *start) {
1671 *start = delalloc_start;
1672 *end = delalloc_end;
1673 free_extent_state(cached_state);
1678 * start comes from the offset of locked_page. We have to lock
1679 * pages in order, so we can't process delalloc bytes before
1682 if (delalloc_start < *start)
1683 delalloc_start = *start;
1686 * make sure to limit the number of pages we try to lock down
1688 if (delalloc_end + 1 - delalloc_start > max_bytes)
1689 delalloc_end = delalloc_start + max_bytes - 1;
1691 /* step two, lock all the pages after the page that has start */
1692 ret = lock_delalloc_pages(inode, locked_page,
1693 delalloc_start, delalloc_end);
1694 if (ret == -EAGAIN) {
1695 /* some of the pages are gone, lets avoid looping by
1696 * shortening the size of the delalloc range we're searching
1698 free_extent_state(cached_state);
1699 cached_state = NULL;
1701 max_bytes = PAGE_SIZE;
1709 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1711 /* step three, lock the state bits for the whole range */
1712 lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
1714 /* then test to make sure it is all still delalloc */
1715 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1716 EXTENT_DELALLOC, 1, cached_state);
1718 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1719 &cached_state, GFP_NOFS);
1720 __unlock_for_delalloc(inode, locked_page,
1721 delalloc_start, delalloc_end);
1725 free_extent_state(cached_state);
1726 *start = delalloc_start;
1727 *end = delalloc_end;
1732 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1733 u64 delalloc_end, struct page *locked_page,
1734 unsigned clear_bits,
1735 unsigned long page_ops)
1737 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
1739 struct page *pages[16];
1740 unsigned long index = start >> PAGE_SHIFT;
1741 unsigned long end_index = end >> PAGE_SHIFT;
1742 unsigned long nr_pages = end_index - index + 1;
1745 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1749 if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
1750 mapping_set_error(inode->i_mapping, -EIO);
1752 while (nr_pages > 0) {
1753 ret = find_get_pages_contig(inode->i_mapping, index,
1754 min_t(unsigned long,
1755 nr_pages, ARRAY_SIZE(pages)), pages);
1756 for (i = 0; i < ret; i++) {
1758 if (page_ops & PAGE_SET_PRIVATE2)
1759 SetPagePrivate2(pages[i]);
1761 if (pages[i] == locked_page) {
1765 if (page_ops & PAGE_CLEAR_DIRTY)
1766 clear_page_dirty_for_io(pages[i]);
1767 if (page_ops & PAGE_SET_WRITEBACK)
1768 set_page_writeback(pages[i]);
1769 if (page_ops & PAGE_SET_ERROR)
1770 SetPageError(pages[i]);
1771 if (page_ops & PAGE_END_WRITEBACK)
1772 end_page_writeback(pages[i]);
1773 if (page_ops & PAGE_UNLOCK)
1774 unlock_page(pages[i]);
1784 * count the number of bytes in the tree that have a given bit(s)
1785 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1786 * cached. The total number found is returned.
1788 u64 count_range_bits(struct extent_io_tree *tree,
1789 u64 *start, u64 search_end, u64 max_bytes,
1790 unsigned bits, int contig)
1792 struct rb_node *node;
1793 struct extent_state *state;
1794 u64 cur_start = *start;
1795 u64 total_bytes = 0;
1799 if (WARN_ON(search_end <= cur_start))
1802 spin_lock(&tree->lock);
1803 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1804 total_bytes = tree->dirty_bytes;
1808 * this search will find all the extents that end after
1811 node = tree_search(tree, cur_start);
1816 state = rb_entry(node, struct extent_state, rb_node);
1817 if (state->start > search_end)
1819 if (contig && found && state->start > last + 1)
1821 if (state->end >= cur_start && (state->state & bits) == bits) {
1822 total_bytes += min(search_end, state->end) + 1 -
1823 max(cur_start, state->start);
1824 if (total_bytes >= max_bytes)
1827 *start = max(cur_start, state->start);
1831 } else if (contig && found) {
1834 node = rb_next(node);
1839 spin_unlock(&tree->lock);
1844 * set the private field for a given byte offset in the tree. If there isn't
1845 * an extent_state there already, this does nothing.
1847 static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start,
1848 struct io_failure_record *failrec)
1850 struct rb_node *node;
1851 struct extent_state *state;
1854 spin_lock(&tree->lock);
1856 * this search will find all the extents that end after
1859 node = tree_search(tree, start);
1864 state = rb_entry(node, struct extent_state, rb_node);
1865 if (state->start != start) {
1869 state->failrec = failrec;
1871 spin_unlock(&tree->lock);
1875 static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start,
1876 struct io_failure_record **failrec)
1878 struct rb_node *node;
1879 struct extent_state *state;
1882 spin_lock(&tree->lock);
1884 * this search will find all the extents that end after
1887 node = tree_search(tree, start);
1892 state = rb_entry(node, struct extent_state, rb_node);
1893 if (state->start != start) {
1897 *failrec = state->failrec;
1899 spin_unlock(&tree->lock);
1904 * searches a range in the state tree for a given mask.
1905 * If 'filled' == 1, this returns 1 only if every extent in the tree
1906 * has the bits set. Otherwise, 1 is returned if any bit in the
1907 * range is found set.
1909 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1910 unsigned bits, int filled, struct extent_state *cached)
1912 struct extent_state *state = NULL;
1913 struct rb_node *node;
1916 spin_lock(&tree->lock);
1917 if (cached && extent_state_in_tree(cached) && cached->start <= start &&
1918 cached->end > start)
1919 node = &cached->rb_node;
1921 node = tree_search(tree, start);
1922 while (node && start <= end) {
1923 state = rb_entry(node, struct extent_state, rb_node);
1925 if (filled && state->start > start) {
1930 if (state->start > end)
1933 if (state->state & bits) {
1937 } else if (filled) {
1942 if (state->end == (u64)-1)
1945 start = state->end + 1;
1948 node = rb_next(node);
1955 spin_unlock(&tree->lock);
1960 * helper function to set a given page up to date if all the
1961 * extents in the tree for that page are up to date
1963 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1965 u64 start = page_offset(page);
1966 u64 end = start + PAGE_SIZE - 1;
1967 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1968 SetPageUptodate(page);
1971 int free_io_failure(struct inode *inode, struct io_failure_record *rec)
1975 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1977 set_state_failrec(failure_tree, rec->start, NULL);
1978 ret = clear_extent_bits(failure_tree, rec->start,
1979 rec->start + rec->len - 1,
1980 EXTENT_LOCKED | EXTENT_DIRTY);
1984 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1985 rec->start + rec->len - 1,
1995 * this bypasses the standard btrfs submit functions deliberately, as
1996 * the standard behavior is to write all copies in a raid setup. here we only
1997 * want to write the one bad copy. so we do the mapping for ourselves and issue
1998 * submit_bio directly.
1999 * to avoid any synchronization issues, wait for the data after writing, which
2000 * actually prevents the read that triggered the error from finishing.
2001 * currently, there can be no more than two copies of every data bit. thus,
2002 * exactly one rewrite is required.
2004 int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical,
2005 struct page *page, unsigned int pg_offset, int mirror_num)
2007 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2009 struct btrfs_device *dev;
2012 struct btrfs_bio *bbio = NULL;
2013 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
2016 ASSERT(!(fs_info->sb->s_flags & MS_RDONLY));
2017 BUG_ON(!mirror_num);
2019 /* we can't repair anything in raid56 yet */
2020 if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num))
2023 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2026 bio->bi_iter.bi_size = 0;
2027 map_length = length;
2030 * Avoid races with device replace and make sure our bbio has devices
2031 * associated to its stripes that don't go away while we are doing the
2032 * read repair operation.
2034 btrfs_bio_counter_inc_blocked(fs_info);
2035 ret = btrfs_map_block(fs_info, WRITE, logical,
2036 &map_length, &bbio, mirror_num);
2038 btrfs_bio_counter_dec(fs_info);
2042 BUG_ON(mirror_num != bbio->mirror_num);
2043 sector = bbio->stripes[mirror_num-1].physical >> 9;
2044 bio->bi_iter.bi_sector = sector;
2045 dev = bbio->stripes[mirror_num-1].dev;
2046 btrfs_put_bbio(bbio);
2047 if (!dev || !dev->bdev || !dev->writeable) {
2048 btrfs_bio_counter_dec(fs_info);
2052 bio->bi_bdev = dev->bdev;
2053 bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_SYNC);
2054 bio_add_page(bio, page, length, pg_offset);
2056 if (btrfsic_submit_bio_wait(bio)) {
2057 /* try to remap that extent elsewhere? */
2058 btrfs_bio_counter_dec(fs_info);
2060 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2064 btrfs_info_rl_in_rcu(fs_info,
2065 "read error corrected: ino %llu off %llu (dev %s sector %llu)",
2066 btrfs_ino(inode), start,
2067 rcu_str_deref(dev->name), sector);
2068 btrfs_bio_counter_dec(fs_info);
2073 int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
2076 u64 start = eb->start;
2077 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
2080 if (root->fs_info->sb->s_flags & MS_RDONLY)
2083 for (i = 0; i < num_pages; i++) {
2084 struct page *p = eb->pages[i];
2086 ret = repair_io_failure(root->fs_info->btree_inode, start,
2087 PAGE_SIZE, start, p,
2088 start - page_offset(p), mirror_num);
2098 * each time an IO finishes, we do a fast check in the IO failure tree
2099 * to see if we need to process or clean up an io_failure_record
2101 int clean_io_failure(struct inode *inode, u64 start, struct page *page,
2102 unsigned int pg_offset)
2105 struct io_failure_record *failrec;
2106 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2107 struct extent_state *state;
2112 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
2113 (u64)-1, 1, EXTENT_DIRTY, 0);
2117 ret = get_state_failrec(&BTRFS_I(inode)->io_failure_tree, start,
2122 BUG_ON(!failrec->this_mirror);
2124 if (failrec->in_validation) {
2125 /* there was no real error, just free the record */
2126 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2130 if (fs_info->sb->s_flags & MS_RDONLY)
2133 spin_lock(&BTRFS_I(inode)->io_tree.lock);
2134 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
2137 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
2139 if (state && state->start <= failrec->start &&
2140 state->end >= failrec->start + failrec->len - 1) {
2141 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2143 if (num_copies > 1) {
2144 repair_io_failure(inode, start, failrec->len,
2145 failrec->logical, page,
2146 pg_offset, failrec->failed_mirror);
2151 free_io_failure(inode, failrec);
2157 * Can be called when
2158 * - hold extent lock
2159 * - under ordered extent
2160 * - the inode is freeing
2162 void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end)
2164 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2165 struct io_failure_record *failrec;
2166 struct extent_state *state, *next;
2168 if (RB_EMPTY_ROOT(&failure_tree->state))
2171 spin_lock(&failure_tree->lock);
2172 state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY);
2174 if (state->start > end)
2177 ASSERT(state->end <= end);
2179 next = next_state(state);
2181 failrec = state->failrec;
2182 free_extent_state(state);
2187 spin_unlock(&failure_tree->lock);
2190 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
2191 struct io_failure_record **failrec_ret)
2193 struct io_failure_record *failrec;
2194 struct extent_map *em;
2195 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2196 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2197 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2201 ret = get_state_failrec(failure_tree, start, &failrec);
2203 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2207 failrec->start = start;
2208 failrec->len = end - start + 1;
2209 failrec->this_mirror = 0;
2210 failrec->bio_flags = 0;
2211 failrec->in_validation = 0;
2213 read_lock(&em_tree->lock);
2214 em = lookup_extent_mapping(em_tree, start, failrec->len);
2216 read_unlock(&em_tree->lock);
2221 if (em->start > start || em->start + em->len <= start) {
2222 free_extent_map(em);
2225 read_unlock(&em_tree->lock);
2231 logical = start - em->start;
2232 logical = em->block_start + logical;
2233 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2234 logical = em->block_start;
2235 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2236 extent_set_compress_type(&failrec->bio_flags,
2240 pr_debug("Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu\n",
2241 logical, start, failrec->len);
2243 failrec->logical = logical;
2244 free_extent_map(em);
2246 /* set the bits in the private failure tree */
2247 ret = set_extent_bits(failure_tree, start, end,
2248 EXTENT_LOCKED | EXTENT_DIRTY);
2250 ret = set_state_failrec(failure_tree, start, failrec);
2251 /* set the bits in the inode's tree */
2253 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED);
2259 pr_debug("Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d\n",
2260 failrec->logical, failrec->start, failrec->len,
2261 failrec->in_validation);
2263 * when data can be on disk more than twice, add to failrec here
2264 * (e.g. with a list for failed_mirror) to make
2265 * clean_io_failure() clean all those errors at once.
2269 *failrec_ret = failrec;
2274 int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
2275 struct io_failure_record *failrec, int failed_mirror)
2279 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
2280 failrec->logical, failrec->len);
2281 if (num_copies == 1) {
2283 * we only have a single copy of the data, so don't bother with
2284 * all the retry and error correction code that follows. no
2285 * matter what the error is, it is very likely to persist.
2287 pr_debug("Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
2288 num_copies, failrec->this_mirror, failed_mirror);
2293 * there are two premises:
2294 * a) deliver good data to the caller
2295 * b) correct the bad sectors on disk
2297 if (failed_bio->bi_vcnt > 1) {
2299 * to fulfill b), we need to know the exact failing sectors, as
2300 * we don't want to rewrite any more than the failed ones. thus,
2301 * we need separate read requests for the failed bio
2303 * if the following BUG_ON triggers, our validation request got
2304 * merged. we need separate requests for our algorithm to work.
2306 BUG_ON(failrec->in_validation);
2307 failrec->in_validation = 1;
2308 failrec->this_mirror = failed_mirror;
2311 * we're ready to fulfill a) and b) alongside. get a good copy
2312 * of the failed sector and if we succeed, we have setup
2313 * everything for repair_io_failure to do the rest for us.
2315 if (failrec->in_validation) {
2316 BUG_ON(failrec->this_mirror != failed_mirror);
2317 failrec->in_validation = 0;
2318 failrec->this_mirror = 0;
2320 failrec->failed_mirror = failed_mirror;
2321 failrec->this_mirror++;
2322 if (failrec->this_mirror == failed_mirror)
2323 failrec->this_mirror++;
2326 if (failrec->this_mirror > num_copies) {
2327 pr_debug("Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
2328 num_copies, failrec->this_mirror, failed_mirror);
2336 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
2337 struct io_failure_record *failrec,
2338 struct page *page, int pg_offset, int icsum,
2339 bio_end_io_t *endio_func, void *data)
2342 struct btrfs_io_bio *btrfs_failed_bio;
2343 struct btrfs_io_bio *btrfs_bio;
2345 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2349 bio->bi_end_io = endio_func;
2350 bio->bi_iter.bi_sector = failrec->logical >> 9;
2351 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
2352 bio->bi_iter.bi_size = 0;
2353 bio->bi_private = data;
2355 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2356 if (btrfs_failed_bio->csum) {
2357 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2358 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2360 btrfs_bio = btrfs_io_bio(bio);
2361 btrfs_bio->csum = btrfs_bio->csum_inline;
2363 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
2367 bio_add_page(bio, page, failrec->len, pg_offset);
2373 * this is a generic handler for readpage errors (default
2374 * readpage_io_failed_hook). if other copies exist, read those and write back
2375 * good data to the failed position. does not investigate in remapping the
2376 * failed extent elsewhere, hoping the device will be smart enough to do this as
2380 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2381 struct page *page, u64 start, u64 end,
2384 struct io_failure_record *failrec;
2385 struct inode *inode = page->mapping->host;
2386 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2391 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
2393 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
2397 ret = btrfs_check_repairable(inode, failed_bio, failrec, failed_mirror);
2399 free_io_failure(inode, failrec);
2403 if (failed_bio->bi_vcnt > 1)
2404 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
2406 read_mode = READ_SYNC;
2408 phy_offset >>= inode->i_sb->s_blocksize_bits;
2409 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
2410 start - page_offset(page),
2411 (int)phy_offset, failed_bio->bi_end_io,
2414 free_io_failure(inode, failrec);
2417 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
2419 pr_debug("Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d\n",
2420 read_mode, failrec->this_mirror, failrec->in_validation);
2422 ret = tree->ops->submit_bio_hook(inode, bio, failrec->this_mirror,
2423 failrec->bio_flags, 0);
2425 free_io_failure(inode, failrec);
2432 /* lots and lots of room for performance fixes in the end_bio funcs */
2434 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2436 int uptodate = (err == 0);
2437 struct extent_io_tree *tree;
2440 tree = &BTRFS_I(page->mapping->host)->io_tree;
2442 if (tree->ops && tree->ops->writepage_end_io_hook) {
2443 ret = tree->ops->writepage_end_io_hook(page, start,
2444 end, NULL, uptodate);
2450 ClearPageUptodate(page);
2452 ret = ret < 0 ? ret : -EIO;
2453 mapping_set_error(page->mapping, ret);
2458 * after a writepage IO is done, we need to:
2459 * clear the uptodate bits on error
2460 * clear the writeback bits in the extent tree for this IO
2461 * end_page_writeback if the page has no more pending IO
2463 * Scheduling is not allowed, so the extent state tree is expected
2464 * to have one and only one object corresponding to this IO.
2466 static void end_bio_extent_writepage(struct bio *bio)
2468 struct bio_vec *bvec;
2473 bio_for_each_segment_all(bvec, bio, i) {
2474 struct page *page = bvec->bv_page;
2476 /* We always issue full-page reads, but if some block
2477 * in a page fails to read, blk_update_request() will
2478 * advance bv_offset and adjust bv_len to compensate.
2479 * Print a warning for nonzero offsets, and an error
2480 * if they don't add up to a full page. */
2481 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2482 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2483 btrfs_err(BTRFS_I(page->mapping->host)->root->fs_info,
2484 "partial page write in btrfs with offset %u and length %u",
2485 bvec->bv_offset, bvec->bv_len);
2487 btrfs_info(BTRFS_I(page->mapping->host)->root->fs_info,
2488 "incomplete page write in btrfs with offset %u and "
2490 bvec->bv_offset, bvec->bv_len);
2493 start = page_offset(page);
2494 end = start + bvec->bv_offset + bvec->bv_len - 1;
2496 end_extent_writepage(page, bio->bi_error, start, end);
2497 end_page_writeback(page);
2504 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2507 struct extent_state *cached = NULL;
2508 u64 end = start + len - 1;
2510 if (uptodate && tree->track_uptodate)
2511 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2512 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2516 * after a readpage IO is done, we need to:
2517 * clear the uptodate bits on error
2518 * set the uptodate bits if things worked
2519 * set the page up to date if all extents in the tree are uptodate
2520 * clear the lock bit in the extent tree
2521 * unlock the page if there are no other extents locked for it
2523 * Scheduling is not allowed, so the extent state tree is expected
2524 * to have one and only one object corresponding to this IO.
2526 static void end_bio_extent_readpage(struct bio *bio)
2528 struct bio_vec *bvec;
2529 int uptodate = !bio->bi_error;
2530 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2531 struct extent_io_tree *tree;
2536 u64 extent_start = 0;
2542 bio_for_each_segment_all(bvec, bio, i) {
2543 struct page *page = bvec->bv_page;
2544 struct inode *inode = page->mapping->host;
2546 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2547 "mirror=%u\n", (u64)bio->bi_iter.bi_sector,
2548 bio->bi_error, io_bio->mirror_num);
2549 tree = &BTRFS_I(inode)->io_tree;
2551 /* We always issue full-page reads, but if some block
2552 * in a page fails to read, blk_update_request() will
2553 * advance bv_offset and adjust bv_len to compensate.
2554 * Print a warning for nonzero offsets, and an error
2555 * if they don't add up to a full page. */
2556 if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) {
2557 if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE)
2558 btrfs_err(BTRFS_I(page->mapping->host)->root->fs_info,
2559 "partial page read in btrfs with offset %u and length %u",
2560 bvec->bv_offset, bvec->bv_len);
2562 btrfs_info(BTRFS_I(page->mapping->host)->root->fs_info,
2563 "incomplete page read in btrfs with offset %u and "
2565 bvec->bv_offset, bvec->bv_len);
2568 start = page_offset(page);
2569 end = start + bvec->bv_offset + bvec->bv_len - 1;
2572 mirror = io_bio->mirror_num;
2573 if (likely(uptodate && tree->ops &&
2574 tree->ops->readpage_end_io_hook)) {
2575 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2581 clean_io_failure(inode, start, page, 0);
2584 if (likely(uptodate))
2587 if (tree->ops && tree->ops->readpage_io_failed_hook) {
2588 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2589 if (!ret && !bio->bi_error)
2593 * The generic bio_readpage_error handles errors the
2594 * following way: If possible, new read requests are
2595 * created and submitted and will end up in
2596 * end_bio_extent_readpage as well (if we're lucky, not
2597 * in the !uptodate case). In that case it returns 0 and
2598 * we just go on with the next page in our bio. If it
2599 * can't handle the error it will return -EIO and we
2600 * remain responsible for that page.
2602 ret = bio_readpage_error(bio, offset, page, start, end,
2605 uptodate = !bio->bi_error;
2611 if (likely(uptodate)) {
2612 loff_t i_size = i_size_read(inode);
2613 pgoff_t end_index = i_size >> PAGE_SHIFT;
2616 /* Zero out the end if this page straddles i_size */
2617 off = i_size & (PAGE_SIZE-1);
2618 if (page->index == end_index && off)
2619 zero_user_segment(page, off, PAGE_SIZE);
2620 SetPageUptodate(page);
2622 ClearPageUptodate(page);
2628 if (unlikely(!uptodate)) {
2630 endio_readpage_release_extent(tree,
2636 endio_readpage_release_extent(tree, start,
2637 end - start + 1, 0);
2638 } else if (!extent_len) {
2639 extent_start = start;
2640 extent_len = end + 1 - start;
2641 } else if (extent_start + extent_len == start) {
2642 extent_len += end + 1 - start;
2644 endio_readpage_release_extent(tree, extent_start,
2645 extent_len, uptodate);
2646 extent_start = start;
2647 extent_len = end + 1 - start;
2652 endio_readpage_release_extent(tree, extent_start, extent_len,
2655 io_bio->end_io(io_bio, bio->bi_error);
2660 * this allocates from the btrfs_bioset. We're returning a bio right now
2661 * but you can call btrfs_io_bio for the appropriate container_of magic
2664 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2667 struct btrfs_io_bio *btrfs_bio;
2670 bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset);
2672 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2673 while (!bio && (nr_vecs /= 2)) {
2674 bio = bio_alloc_bioset(gfp_flags,
2675 nr_vecs, btrfs_bioset);
2680 bio->bi_bdev = bdev;
2681 bio->bi_iter.bi_sector = first_sector;
2682 btrfs_bio = btrfs_io_bio(bio);
2683 btrfs_bio->csum = NULL;
2684 btrfs_bio->csum_allocated = NULL;
2685 btrfs_bio->end_io = NULL;
2690 struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
2692 struct btrfs_io_bio *btrfs_bio;
2695 new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset);
2697 btrfs_bio = btrfs_io_bio(new);
2698 btrfs_bio->csum = NULL;
2699 btrfs_bio->csum_allocated = NULL;
2700 btrfs_bio->end_io = NULL;
2705 /* this also allocates from the btrfs_bioset */
2706 struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
2708 struct btrfs_io_bio *btrfs_bio;
2711 bio = bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
2713 btrfs_bio = btrfs_io_bio(bio);
2714 btrfs_bio->csum = NULL;
2715 btrfs_bio->csum_allocated = NULL;
2716 btrfs_bio->end_io = NULL;
2722 static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
2723 unsigned long bio_flags)
2726 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2727 struct page *page = bvec->bv_page;
2728 struct extent_io_tree *tree = bio->bi_private;
2731 start = page_offset(page) + bvec->bv_offset;
2733 bio->bi_private = NULL;
2736 if (tree->ops && tree->ops->submit_bio_hook)
2737 ret = tree->ops->submit_bio_hook(page->mapping->host, bio,
2738 mirror_num, bio_flags, start);
2740 btrfsic_submit_bio(bio);
2746 static int merge_bio(struct extent_io_tree *tree, struct page *page,
2747 unsigned long offset, size_t size, struct bio *bio,
2748 unsigned long bio_flags)
2751 if (tree->ops && tree->ops->merge_bio_hook)
2752 ret = tree->ops->merge_bio_hook(page, offset, size, bio,
2758 static int submit_extent_page(int op, int op_flags, struct extent_io_tree *tree,
2759 struct writeback_control *wbc,
2760 struct page *page, sector_t sector,
2761 size_t size, unsigned long offset,
2762 struct block_device *bdev,
2763 struct bio **bio_ret,
2764 unsigned long max_pages,
2765 bio_end_io_t end_io_func,
2767 unsigned long prev_bio_flags,
2768 unsigned long bio_flags,
2769 bool force_bio_submit)
2774 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2775 size_t page_size = min_t(size_t, size, PAGE_SIZE);
2777 if (bio_ret && *bio_ret) {
2780 contig = bio->bi_iter.bi_sector == sector;
2782 contig = bio_end_sector(bio) == sector;
2784 if (prev_bio_flags != bio_flags || !contig ||
2786 merge_bio(tree, page, offset, page_size, bio, bio_flags) ||
2787 bio_add_page(bio, page, page_size, offset) < page_size) {
2788 ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
2796 wbc_account_io(wbc, page, page_size);
2801 bio = btrfs_bio_alloc(bdev, sector, BIO_MAX_PAGES,
2802 GFP_NOFS | __GFP_HIGH);
2806 bio_add_page(bio, page, page_size, offset);
2807 bio->bi_end_io = end_io_func;
2808 bio->bi_private = tree;
2809 bio_set_op_attrs(bio, op, op_flags);
2811 wbc_init_bio(wbc, bio);
2812 wbc_account_io(wbc, page, page_size);
2818 ret = submit_one_bio(bio, mirror_num, bio_flags);
2823 static void attach_extent_buffer_page(struct extent_buffer *eb,
2826 if (!PagePrivate(page)) {
2827 SetPagePrivate(page);
2829 set_page_private(page, (unsigned long)eb);
2831 WARN_ON(page->private != (unsigned long)eb);
2835 void set_page_extent_mapped(struct page *page)
2837 if (!PagePrivate(page)) {
2838 SetPagePrivate(page);
2840 set_page_private(page, EXTENT_PAGE_PRIVATE);
2844 static struct extent_map *
2845 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
2846 u64 start, u64 len, get_extent_t *get_extent,
2847 struct extent_map **em_cached)
2849 struct extent_map *em;
2851 if (em_cached && *em_cached) {
2853 if (extent_map_in_tree(em) && start >= em->start &&
2854 start < extent_map_end(em)) {
2855 atomic_inc(&em->refs);
2859 free_extent_map(em);
2863 em = get_extent(inode, page, pg_offset, start, len, 0);
2864 if (em_cached && !IS_ERR_OR_NULL(em)) {
2866 atomic_inc(&em->refs);
2872 * basic readpage implementation. Locked extent state structs are inserted
2873 * into the tree that are removed when the IO is done (by the end_io
2875 * XXX JDM: This needs looking at to ensure proper page locking
2876 * return 0 on success, otherwise return error
2878 static int __do_readpage(struct extent_io_tree *tree,
2880 get_extent_t *get_extent,
2881 struct extent_map **em_cached,
2882 struct bio **bio, int mirror_num,
2883 unsigned long *bio_flags, int read_flags,
2886 struct inode *inode = page->mapping->host;
2887 u64 start = page_offset(page);
2888 u64 page_end = start + PAGE_SIZE - 1;
2892 u64 last_byte = i_size_read(inode);
2896 struct extent_map *em;
2897 struct block_device *bdev;
2900 size_t pg_offset = 0;
2902 size_t disk_io_size;
2903 size_t blocksize = inode->i_sb->s_blocksize;
2904 unsigned long this_bio_flag = 0;
2906 set_page_extent_mapped(page);
2909 if (!PageUptodate(page)) {
2910 if (cleancache_get_page(page) == 0) {
2911 BUG_ON(blocksize != PAGE_SIZE);
2912 unlock_extent(tree, start, end);
2917 if (page->index == last_byte >> PAGE_SHIFT) {
2919 size_t zero_offset = last_byte & (PAGE_SIZE - 1);
2922 iosize = PAGE_SIZE - zero_offset;
2923 userpage = kmap_atomic(page);
2924 memset(userpage + zero_offset, 0, iosize);
2925 flush_dcache_page(page);
2926 kunmap_atomic(userpage);
2929 while (cur <= end) {
2930 unsigned long pnr = (last_byte >> PAGE_SHIFT) + 1;
2931 bool force_bio_submit = false;
2933 if (cur >= last_byte) {
2935 struct extent_state *cached = NULL;
2937 iosize = PAGE_SIZE - pg_offset;
2938 userpage = kmap_atomic(page);
2939 memset(userpage + pg_offset, 0, iosize);
2940 flush_dcache_page(page);
2941 kunmap_atomic(userpage);
2942 set_extent_uptodate(tree, cur, cur + iosize - 1,
2944 unlock_extent_cached(tree, cur,
2949 em = __get_extent_map(inode, page, pg_offset, cur,
2950 end - cur + 1, get_extent, em_cached);
2951 if (IS_ERR_OR_NULL(em)) {
2953 unlock_extent(tree, cur, end);
2956 extent_offset = cur - em->start;
2957 BUG_ON(extent_map_end(em) <= cur);
2960 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2961 this_bio_flag |= EXTENT_BIO_COMPRESSED;
2962 extent_set_compress_type(&this_bio_flag,
2966 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2967 cur_end = min(extent_map_end(em) - 1, end);
2968 iosize = ALIGN(iosize, blocksize);
2969 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2970 disk_io_size = em->block_len;
2971 sector = em->block_start >> 9;
2973 sector = (em->block_start + extent_offset) >> 9;
2974 disk_io_size = iosize;
2977 block_start = em->block_start;
2978 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2979 block_start = EXTENT_MAP_HOLE;
2982 * If we have a file range that points to a compressed extent
2983 * and it's followed by a consecutive file range that points to
2984 * to the same compressed extent (possibly with a different
2985 * offset and/or length, so it either points to the whole extent
2986 * or only part of it), we must make sure we do not submit a
2987 * single bio to populate the pages for the 2 ranges because
2988 * this makes the compressed extent read zero out the pages
2989 * belonging to the 2nd range. Imagine the following scenario:
2992 * [0 - 8K] [8K - 24K]
2995 * points to extent X, points to extent X,
2996 * offset 4K, length of 8K offset 0, length 16K
2998 * [extent X, compressed length = 4K uncompressed length = 16K]
3000 * If the bio to read the compressed extent covers both ranges,
3001 * it will decompress extent X into the pages belonging to the
3002 * first range and then it will stop, zeroing out the remaining
3003 * pages that belong to the other range that points to extent X.
3004 * So here we make sure we submit 2 bios, one for the first
3005 * range and another one for the third range. Both will target
3006 * the same physical extent from disk, but we can't currently
3007 * make the compressed bio endio callback populate the pages
3008 * for both ranges because each compressed bio is tightly
3009 * coupled with a single extent map, and each range can have
3010 * an extent map with a different offset value relative to the
3011 * uncompressed data of our extent and different lengths. This
3012 * is a corner case so we prioritize correctness over
3013 * non-optimal behavior (submitting 2 bios for the same extent).
3015 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
3016 prev_em_start && *prev_em_start != (u64)-1 &&
3017 *prev_em_start != em->orig_start)
3018 force_bio_submit = true;
3021 *prev_em_start = em->orig_start;
3023 free_extent_map(em);
3026 /* we've found a hole, just zero and go on */
3027 if (block_start == EXTENT_MAP_HOLE) {
3029 struct extent_state *cached = NULL;
3031 userpage = kmap_atomic(page);
3032 memset(userpage + pg_offset, 0, iosize);
3033 flush_dcache_page(page);
3034 kunmap_atomic(userpage);
3036 set_extent_uptodate(tree, cur, cur + iosize - 1,
3038 unlock_extent_cached(tree, cur,
3042 pg_offset += iosize;
3045 /* the get_extent function already copied into the page */
3046 if (test_range_bit(tree, cur, cur_end,
3047 EXTENT_UPTODATE, 1, NULL)) {
3048 check_page_uptodate(tree, page);
3049 unlock_extent(tree, cur, cur + iosize - 1);
3051 pg_offset += iosize;
3054 /* we have an inline extent but it didn't get marked up
3055 * to date. Error out
3057 if (block_start == EXTENT_MAP_INLINE) {
3059 unlock_extent(tree, cur, cur + iosize - 1);
3061 pg_offset += iosize;
3066 ret = submit_extent_page(REQ_OP_READ, read_flags, tree, NULL,
3067 page, sector, disk_io_size, pg_offset,
3069 end_bio_extent_readpage, mirror_num,
3075 *bio_flags = this_bio_flag;
3078 unlock_extent(tree, cur, cur + iosize - 1);
3082 pg_offset += iosize;
3086 if (!PageError(page))
3087 SetPageUptodate(page);
3093 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
3094 struct page *pages[], int nr_pages,
3096 get_extent_t *get_extent,
3097 struct extent_map **em_cached,
3098 struct bio **bio, int mirror_num,
3099 unsigned long *bio_flags,
3102 struct inode *inode;
3103 struct btrfs_ordered_extent *ordered;
3106 inode = pages[0]->mapping->host;
3108 lock_extent(tree, start, end);
3109 ordered = btrfs_lookup_ordered_range(inode, start,
3113 unlock_extent(tree, start, end);
3114 btrfs_start_ordered_extent(inode, ordered, 1);
3115 btrfs_put_ordered_extent(ordered);
3118 for (index = 0; index < nr_pages; index++) {
3119 __do_readpage(tree, pages[index], get_extent, em_cached, bio,
3120 mirror_num, bio_flags, 0, prev_em_start);
3121 put_page(pages[index]);
3125 static void __extent_readpages(struct extent_io_tree *tree,
3126 struct page *pages[],
3127 int nr_pages, get_extent_t *get_extent,
3128 struct extent_map **em_cached,
3129 struct bio **bio, int mirror_num,
3130 unsigned long *bio_flags,
3137 int first_index = 0;
3139 for (index = 0; index < nr_pages; index++) {
3140 page_start = page_offset(pages[index]);
3143 end = start + PAGE_SIZE - 1;
3144 first_index = index;
3145 } else if (end + 1 == page_start) {
3148 __do_contiguous_readpages(tree, &pages[first_index],
3149 index - first_index, start,
3150 end, get_extent, em_cached,
3151 bio, mirror_num, bio_flags,
3154 end = start + PAGE_SIZE - 1;
3155 first_index = index;
3160 __do_contiguous_readpages(tree, &pages[first_index],
3161 index - first_index, start,
3162 end, get_extent, em_cached, bio,
3163 mirror_num, bio_flags,
3167 static int __extent_read_full_page(struct extent_io_tree *tree,
3169 get_extent_t *get_extent,
3170 struct bio **bio, int mirror_num,
3171 unsigned long *bio_flags, int read_flags)
3173 struct inode *inode = page->mapping->host;
3174 struct btrfs_ordered_extent *ordered;
3175 u64 start = page_offset(page);
3176 u64 end = start + PAGE_SIZE - 1;
3180 lock_extent(tree, start, end);
3181 ordered = btrfs_lookup_ordered_range(inode, start,
3185 unlock_extent(tree, start, end);
3186 btrfs_start_ordered_extent(inode, ordered, 1);
3187 btrfs_put_ordered_extent(ordered);
3190 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3191 bio_flags, read_flags, NULL);
3195 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3196 get_extent_t *get_extent, int mirror_num)
3198 struct bio *bio = NULL;
3199 unsigned long bio_flags = 0;
3202 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3205 ret = submit_one_bio(bio, mirror_num, bio_flags);
3209 static void update_nr_written(struct page *page, struct writeback_control *wbc,
3210 unsigned long nr_written)
3212 wbc->nr_to_write -= nr_written;
3216 * helper for __extent_writepage, doing all of the delayed allocation setup.
3218 * This returns 1 if our fill_delalloc function did all the work required
3219 * to write the page (copy into inline extent). In this case the IO has
3220 * been started and the page is already unlocked.
3222 * This returns 0 if all went well (page still locked)
3223 * This returns < 0 if there were errors (page still locked)
3225 static noinline_for_stack int writepage_delalloc(struct inode *inode,
3226 struct page *page, struct writeback_control *wbc,
3227 struct extent_page_data *epd,
3229 unsigned long *nr_written)
3231 struct extent_io_tree *tree = epd->tree;
3232 u64 page_end = delalloc_start + PAGE_SIZE - 1;
3234 u64 delalloc_to_write = 0;
3235 u64 delalloc_end = 0;
3237 int page_started = 0;
3239 if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
3242 while (delalloc_end < page_end) {
3243 nr_delalloc = find_lock_delalloc_range(inode, tree,
3247 BTRFS_MAX_EXTENT_SIZE);
3248 if (nr_delalloc == 0) {
3249 delalloc_start = delalloc_end + 1;
3252 ret = tree->ops->fill_delalloc(inode, page,
3257 /* File system has been set read-only */
3260 /* fill_delalloc should be return < 0 for error
3261 * but just in case, we use > 0 here meaning the
3262 * IO is started, so we don't want to return > 0
3263 * unless things are going well.
3265 ret = ret < 0 ? ret : -EIO;
3269 * delalloc_end is already one less than the total length, so
3270 * we don't subtract one from PAGE_SIZE
3272 delalloc_to_write += (delalloc_end - delalloc_start +
3273 PAGE_SIZE) >> PAGE_SHIFT;
3274 delalloc_start = delalloc_end + 1;
3276 if (wbc->nr_to_write < delalloc_to_write) {
3279 if (delalloc_to_write < thresh * 2)
3280 thresh = delalloc_to_write;
3281 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3285 /* did the fill delalloc function already unlock and start
3290 * we've unlocked the page, so we can't update
3291 * the mapping's writeback index, just update
3294 wbc->nr_to_write -= *nr_written;
3305 * helper for __extent_writepage. This calls the writepage start hooks,
3306 * and does the loop to map the page into extents and bios.
3308 * We return 1 if the IO is started and the page is unlocked,
3309 * 0 if all went well (page still locked)
3310 * < 0 if there were errors (page still locked)
3312 static noinline_for_stack int __extent_writepage_io(struct inode *inode,
3314 struct writeback_control *wbc,
3315 struct extent_page_data *epd,
3317 unsigned long nr_written,
3318 int write_flags, int *nr_ret)
3320 struct extent_io_tree *tree = epd->tree;
3321 u64 start = page_offset(page);
3322 u64 page_end = start + PAGE_SIZE - 1;
3329 struct extent_state *cached_state = NULL;
3330 struct extent_map *em;
3331 struct block_device *bdev;
3332 size_t pg_offset = 0;
3338 if (tree->ops && tree->ops->writepage_start_hook) {
3339 ret = tree->ops->writepage_start_hook(page, start,
3342 /* Fixup worker will requeue */
3344 wbc->pages_skipped++;
3346 redirty_page_for_writepage(wbc, page);
3348 update_nr_written(page, wbc, nr_written);
3356 * we don't want to touch the inode after unlocking the page,
3357 * so we update the mapping writeback index now
3359 update_nr_written(page, wbc, nr_written + 1);
3362 if (i_size <= start) {
3363 if (tree->ops && tree->ops->writepage_end_io_hook)
3364 tree->ops->writepage_end_io_hook(page, start,
3369 blocksize = inode->i_sb->s_blocksize;
3371 while (cur <= end) {
3373 unsigned long max_nr;
3375 if (cur >= i_size) {
3376 if (tree->ops && tree->ops->writepage_end_io_hook)
3377 tree->ops->writepage_end_io_hook(page, cur,
3381 em = epd->get_extent(inode, page, pg_offset, cur,
3383 if (IS_ERR_OR_NULL(em)) {
3385 ret = PTR_ERR_OR_ZERO(em);
3389 extent_offset = cur - em->start;
3390 em_end = extent_map_end(em);
3391 BUG_ON(em_end <= cur);
3393 iosize = min(em_end - cur, end - cur + 1);
3394 iosize = ALIGN(iosize, blocksize);
3395 sector = (em->block_start + extent_offset) >> 9;
3397 block_start = em->block_start;
3398 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3399 free_extent_map(em);
3403 * compressed and inline extents are written through other
3406 if (compressed || block_start == EXTENT_MAP_HOLE ||
3407 block_start == EXTENT_MAP_INLINE) {
3409 * end_io notification does not happen here for
3410 * compressed extents
3412 if (!compressed && tree->ops &&
3413 tree->ops->writepage_end_io_hook)
3414 tree->ops->writepage_end_io_hook(page, cur,
3417 else if (compressed) {
3418 /* we don't want to end_page_writeback on
3419 * a compressed extent. this happens
3426 pg_offset += iosize;
3430 max_nr = (i_size >> PAGE_SHIFT) + 1;
3432 set_range_writeback(tree, cur, cur + iosize - 1);
3433 if (!PageWriteback(page)) {
3434 btrfs_err(BTRFS_I(inode)->root->fs_info,
3435 "page %lu not writeback, cur %llu end %llu",
3436 page->index, cur, end);
3439 ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
3440 page, sector, iosize, pg_offset,
3441 bdev, &epd->bio, max_nr,
3442 end_bio_extent_writepage,
3448 pg_offset += iosize;
3456 /* drop our reference on any cached states */
3457 free_extent_state(cached_state);
3462 * the writepage semantics are similar to regular writepage. extent
3463 * records are inserted to lock ranges in the tree, and as dirty areas
3464 * are found, they are marked writeback. Then the lock bits are removed
3465 * and the end_io handler clears the writeback ranges
3467 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3470 struct inode *inode = page->mapping->host;
3471 struct extent_page_data *epd = data;
3472 u64 start = page_offset(page);
3473 u64 page_end = start + PAGE_SIZE - 1;
3476 size_t pg_offset = 0;
3477 loff_t i_size = i_size_read(inode);
3478 unsigned long end_index = i_size >> PAGE_SHIFT;
3479 int write_flags = 0;
3480 unsigned long nr_written = 0;
3482 if (wbc->sync_mode == WB_SYNC_ALL)
3483 write_flags = WRITE_SYNC;
3485 trace___extent_writepage(page, inode, wbc);
3487 WARN_ON(!PageLocked(page));
3489 ClearPageError(page);
3491 pg_offset = i_size & (PAGE_SIZE - 1);
3492 if (page->index > end_index ||
3493 (page->index == end_index && !pg_offset)) {
3494 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
3499 if (page->index == end_index) {
3502 userpage = kmap_atomic(page);
3503 memset(userpage + pg_offset, 0,
3504 PAGE_SIZE - pg_offset);
3505 kunmap_atomic(userpage);
3506 flush_dcache_page(page);
3511 set_page_extent_mapped(page);
3513 ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
3519 ret = __extent_writepage_io(inode, page, wbc, epd,
3520 i_size, nr_written, write_flags, &nr);
3526 /* make sure the mapping tag for page dirty gets cleared */
3527 set_page_writeback(page);
3528 end_page_writeback(page);
3530 if (PageError(page)) {
3531 ret = ret < 0 ? ret : -EIO;
3532 end_extent_writepage(page, ret, start, page_end);
3541 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3543 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
3544 TASK_UNINTERRUPTIBLE);
3547 static noinline_for_stack int
3548 lock_extent_buffer_for_io(struct extent_buffer *eb,
3549 struct btrfs_fs_info *fs_info,
3550 struct extent_page_data *epd)
3552 unsigned long i, num_pages;
3556 if (!btrfs_try_tree_write_lock(eb)) {
3558 flush_write_bio(epd);
3559 btrfs_tree_lock(eb);
3562 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3563 btrfs_tree_unlock(eb);
3567 flush_write_bio(epd);
3571 wait_on_extent_buffer_writeback(eb);
3572 btrfs_tree_lock(eb);
3573 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3575 btrfs_tree_unlock(eb);
3580 * We need to do this to prevent races in people who check if the eb is
3581 * under IO since we can end up having no IO bits set for a short period
3584 spin_lock(&eb->refs_lock);
3585 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3586 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3587 spin_unlock(&eb->refs_lock);
3588 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3589 __percpu_counter_add(&fs_info->dirty_metadata_bytes,
3591 fs_info->dirty_metadata_batch);
3594 spin_unlock(&eb->refs_lock);
3597 btrfs_tree_unlock(eb);
3602 num_pages = num_extent_pages(eb->start, eb->len);
3603 for (i = 0; i < num_pages; i++) {
3604 struct page *p = eb->pages[i];
3606 if (!trylock_page(p)) {
3608 flush_write_bio(epd);
3618 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3620 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3621 smp_mb__after_atomic();
3622 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3625 static void set_btree_ioerr(struct page *page)
3627 struct extent_buffer *eb = (struct extent_buffer *)page->private;
3628 struct btrfs_inode *btree_ino = BTRFS_I(eb->fs_info->btree_inode);
3631 if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
3635 * If writeback for a btree extent that doesn't belong to a log tree
3636 * failed, increment the counter transaction->eb_write_errors.
3637 * We do this because while the transaction is running and before it's
3638 * committing (when we call filemap_fdata[write|wait]_range against
3639 * the btree inode), we might have
3640 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
3641 * returns an error or an error happens during writeback, when we're
3642 * committing the transaction we wouldn't know about it, since the pages
3643 * can be no longer dirty nor marked anymore for writeback (if a
3644 * subsequent modification to the extent buffer didn't happen before the
3645 * transaction commit), which makes filemap_fdata[write|wait]_range not
3646 * able to find the pages tagged with SetPageError at transaction
3647 * commit time. So if this happens we must abort the transaction,
3648 * otherwise we commit a super block with btree roots that point to
3649 * btree nodes/leafs whose content on disk is invalid - either garbage
3650 * or the content of some node/leaf from a past generation that got
3651 * cowed or deleted and is no longer valid.
3653 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
3654 * not be enough - we need to distinguish between log tree extents vs
3655 * non-log tree extents, and the next filemap_fdatawait_range() call
3656 * will catch and clear such errors in the mapping - and that call might
3657 * be from a log sync and not from a transaction commit. Also, checking
3658 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
3659 * not done and would not be reliable - the eb might have been released
3660 * from memory and reading it back again means that flag would not be
3661 * set (since it's a runtime flag, not persisted on disk).
3663 * Using the flags below in the btree inode also makes us achieve the
3664 * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
3665 * writeback for all dirty pages and before filemap_fdatawait_range()
3666 * is called, the writeback for all dirty pages had already finished
3667 * with errors - because we were not using AS_EIO/AS_ENOSPC,
3668 * filemap_fdatawait_range() would return success, as it could not know
3669 * that writeback errors happened (the pages were no longer tagged for
3672 switch (eb->log_index) {
3674 set_bit(BTRFS_INODE_BTREE_ERR, &btree_ino->runtime_flags);
3677 set_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags);
3680 set_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags);
3683 BUG(); /* unexpected, logic error */
3687 static void end_bio_extent_buffer_writepage(struct bio *bio)
3689 struct bio_vec *bvec;
3690 struct extent_buffer *eb;
3693 bio_for_each_segment_all(bvec, bio, i) {
3694 struct page *page = bvec->bv_page;
3696 eb = (struct extent_buffer *)page->private;
3698 done = atomic_dec_and_test(&eb->io_pages);
3700 if (bio->bi_error ||
3701 test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
3702 ClearPageUptodate(page);
3703 set_btree_ioerr(page);
3706 end_page_writeback(page);
3711 end_extent_buffer_writeback(eb);
3717 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
3718 struct btrfs_fs_info *fs_info,
3719 struct writeback_control *wbc,
3720 struct extent_page_data *epd)
3722 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3723 struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
3724 u64 offset = eb->start;
3725 unsigned long i, num_pages;
3726 unsigned long bio_flags = 0;
3727 int write_flags = (epd->sync_io ? WRITE_SYNC : 0) | REQ_META;
3730 clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
3731 num_pages = num_extent_pages(eb->start, eb->len);
3732 atomic_set(&eb->io_pages, num_pages);
3733 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3734 bio_flags = EXTENT_BIO_TREE_LOG;
3736 for (i = 0; i < num_pages; i++) {
3737 struct page *p = eb->pages[i];
3739 clear_page_dirty_for_io(p);
3740 set_page_writeback(p);
3741 ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
3742 p, offset >> 9, PAGE_SIZE, 0, bdev,
3744 end_bio_extent_buffer_writepage,
3745 0, epd->bio_flags, bio_flags, false);
3746 epd->bio_flags = bio_flags;
3749 end_page_writeback(p);
3750 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3751 end_extent_buffer_writeback(eb);
3755 offset += PAGE_SIZE;
3756 update_nr_written(p, wbc, 1);
3760 if (unlikely(ret)) {
3761 for (; i < num_pages; i++) {
3762 struct page *p = eb->pages[i];
3763 clear_page_dirty_for_io(p);
3771 int btree_write_cache_pages(struct address_space *mapping,
3772 struct writeback_control *wbc)
3774 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3775 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3776 struct extent_buffer *eb, *prev_eb = NULL;
3777 struct extent_page_data epd = {
3781 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3786 int nr_to_write_done = 0;
3787 struct pagevec pvec;
3790 pgoff_t end; /* Inclusive */
3794 pagevec_init(&pvec, 0);
3795 if (wbc->range_cyclic) {
3796 index = mapping->writeback_index; /* Start from prev offset */
3799 index = wbc->range_start >> PAGE_SHIFT;
3800 end = wbc->range_end >> PAGE_SHIFT;
3803 if (wbc->sync_mode == WB_SYNC_ALL)
3804 tag = PAGECACHE_TAG_TOWRITE;
3806 tag = PAGECACHE_TAG_DIRTY;
3808 if (wbc->sync_mode == WB_SYNC_ALL)
3809 tag_pages_for_writeback(mapping, index, end);
3810 while (!done && !nr_to_write_done && (index <= end) &&
3811 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3812 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3816 for (i = 0; i < nr_pages; i++) {
3817 struct page *page = pvec.pages[i];
3819 if (!PagePrivate(page))
3822 if (!wbc->range_cyclic && page->index > end) {
3827 spin_lock(&mapping->private_lock);
3828 if (!PagePrivate(page)) {
3829 spin_unlock(&mapping->private_lock);
3833 eb = (struct extent_buffer *)page->private;
3836 * Shouldn't happen and normally this would be a BUG_ON
3837 * but no sense in crashing the users box for something
3838 * we can survive anyway.
3841 spin_unlock(&mapping->private_lock);
3845 if (eb == prev_eb) {
3846 spin_unlock(&mapping->private_lock);
3850 ret = atomic_inc_not_zero(&eb->refs);
3851 spin_unlock(&mapping->private_lock);
3856 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3858 free_extent_buffer(eb);
3862 ret = write_one_eb(eb, fs_info, wbc, &epd);
3865 free_extent_buffer(eb);
3868 free_extent_buffer(eb);
3871 * the filesystem may choose to bump up nr_to_write.
3872 * We have to make sure to honor the new nr_to_write
3875 nr_to_write_done = wbc->nr_to_write <= 0;
3877 pagevec_release(&pvec);
3880 if (!scanned && !done) {
3882 * We hit the last page and there is more work to be done: wrap
3883 * back to the start of the file
3889 flush_write_bio(&epd);
3894 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3895 * @mapping: address space structure to write
3896 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3897 * @writepage: function called for each page
3898 * @data: data passed to writepage function
3900 * If a page is already under I/O, write_cache_pages() skips it, even
3901 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3902 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3903 * and msync() need to guarantee that all the data which was dirty at the time
3904 * the call was made get new I/O started against them. If wbc->sync_mode is
3905 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3906 * existing IO to complete.
3908 static int extent_write_cache_pages(struct extent_io_tree *tree,
3909 struct address_space *mapping,
3910 struct writeback_control *wbc,
3911 writepage_t writepage, void *data,
3912 void (*flush_fn)(void *))
3914 struct inode *inode = mapping->host;
3917 int nr_to_write_done = 0;
3918 struct pagevec pvec;
3921 pgoff_t end; /* Inclusive */
3923 int range_whole = 0;
3928 * We have to hold onto the inode so that ordered extents can do their
3929 * work when the IO finishes. The alternative to this is failing to add
3930 * an ordered extent if the igrab() fails there and that is a huge pain
3931 * to deal with, so instead just hold onto the inode throughout the
3932 * writepages operation. If it fails here we are freeing up the inode
3933 * anyway and we'd rather not waste our time writing out stuff that is
3934 * going to be truncated anyway.
3939 pagevec_init(&pvec, 0);
3940 if (wbc->range_cyclic) {
3941 index = mapping->writeback_index; /* Start from prev offset */
3944 index = wbc->range_start >> PAGE_SHIFT;
3945 end = wbc->range_end >> PAGE_SHIFT;
3946 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
3950 if (wbc->sync_mode == WB_SYNC_ALL)
3951 tag = PAGECACHE_TAG_TOWRITE;
3953 tag = PAGECACHE_TAG_DIRTY;
3955 if (wbc->sync_mode == WB_SYNC_ALL)
3956 tag_pages_for_writeback(mapping, index, end);
3958 while (!done && !nr_to_write_done && (index <= end) &&
3959 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3960 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3964 for (i = 0; i < nr_pages; i++) {
3965 struct page *page = pvec.pages[i];
3967 done_index = page->index;
3969 * At this point we hold neither mapping->tree_lock nor
3970 * lock on the page itself: the page may be truncated or
3971 * invalidated (changing page->mapping to NULL), or even
3972 * swizzled back from swapper_space to tmpfs file
3975 if (!trylock_page(page)) {
3980 if (unlikely(page->mapping != mapping)) {
3985 if (!wbc->range_cyclic && page->index > end) {
3991 if (wbc->sync_mode != WB_SYNC_NONE) {
3992 if (PageWriteback(page))
3994 wait_on_page_writeback(page);
3997 if (PageWriteback(page) ||
3998 !clear_page_dirty_for_io(page)) {
4003 ret = (*writepage)(page, wbc, data);
4005 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
4011 * done_index is set past this page,
4012 * so media errors will not choke
4013 * background writeout for the entire
4014 * file. This has consequences for
4015 * range_cyclic semantics (ie. it may
4016 * not be suitable for data integrity
4019 done_index = page->index + 1;
4025 * the filesystem may choose to bump up nr_to_write.
4026 * We have to make sure to honor the new nr_to_write
4029 nr_to_write_done = wbc->nr_to_write <= 0;
4031 pagevec_release(&pvec);
4034 if (!scanned && !done) {
4036 * We hit the last page and there is more work to be done: wrap
4037 * back to the start of the file
4044 if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
4045 mapping->writeback_index = done_index;
4047 btrfs_add_delayed_iput(inode);
4051 static void flush_epd_write_bio(struct extent_page_data *epd)
4056 bio_set_op_attrs(epd->bio, REQ_OP_WRITE,
4057 epd->sync_io ? WRITE_SYNC : 0);
4059 ret = submit_one_bio(epd->bio, 0, epd->bio_flags);
4060 BUG_ON(ret < 0); /* -ENOMEM */
4065 static noinline void flush_write_bio(void *data)
4067 struct extent_page_data *epd = data;
4068 flush_epd_write_bio(epd);
4071 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
4072 get_extent_t *get_extent,
4073 struct writeback_control *wbc)
4076 struct extent_page_data epd = {
4079 .get_extent = get_extent,
4081 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4085 ret = __extent_writepage(page, wbc, &epd);
4087 flush_epd_write_bio(&epd);
4091 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
4092 u64 start, u64 end, get_extent_t *get_extent,
4096 struct address_space *mapping = inode->i_mapping;
4098 unsigned long nr_pages = (end - start + PAGE_SIZE) >>
4101 struct extent_page_data epd = {
4104 .get_extent = get_extent,
4106 .sync_io = mode == WB_SYNC_ALL,
4109 struct writeback_control wbc_writepages = {
4111 .nr_to_write = nr_pages * 2,
4112 .range_start = start,
4113 .range_end = end + 1,
4116 while (start <= end) {
4117 page = find_get_page(mapping, start >> PAGE_SHIFT);
4118 if (clear_page_dirty_for_io(page))
4119 ret = __extent_writepage(page, &wbc_writepages, &epd);
4121 if (tree->ops && tree->ops->writepage_end_io_hook)
4122 tree->ops->writepage_end_io_hook(page, start,
4123 start + PAGE_SIZE - 1,
4131 flush_epd_write_bio(&epd);
4135 int extent_writepages(struct extent_io_tree *tree,
4136 struct address_space *mapping,
4137 get_extent_t *get_extent,
4138 struct writeback_control *wbc)
4141 struct extent_page_data epd = {
4144 .get_extent = get_extent,
4146 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
4150 ret = extent_write_cache_pages(tree, mapping, wbc,
4151 __extent_writepage, &epd,
4153 flush_epd_write_bio(&epd);
4157 int extent_readpages(struct extent_io_tree *tree,
4158 struct address_space *mapping,
4159 struct list_head *pages, unsigned nr_pages,
4160 get_extent_t get_extent)
4162 struct bio *bio = NULL;
4164 unsigned long bio_flags = 0;
4165 struct page *pagepool[16];
4167 struct extent_map *em_cached = NULL;
4169 u64 prev_em_start = (u64)-1;
4171 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
4172 page = list_entry(pages->prev, struct page, lru);
4174 prefetchw(&page->flags);
4175 list_del(&page->lru);
4176 if (add_to_page_cache_lru(page, mapping,
4178 readahead_gfp_mask(mapping))) {
4183 pagepool[nr++] = page;
4184 if (nr < ARRAY_SIZE(pagepool))
4186 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4187 &bio, 0, &bio_flags, &prev_em_start);
4191 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
4192 &bio, 0, &bio_flags, &prev_em_start);
4195 free_extent_map(em_cached);
4197 BUG_ON(!list_empty(pages));
4199 return submit_one_bio(bio, 0, bio_flags);
4204 * basic invalidatepage code, this waits on any locked or writeback
4205 * ranges corresponding to the page, and then deletes any extent state
4206 * records from the tree
4208 int extent_invalidatepage(struct extent_io_tree *tree,
4209 struct page *page, unsigned long offset)
4211 struct extent_state *cached_state = NULL;
4212 u64 start = page_offset(page);
4213 u64 end = start + PAGE_SIZE - 1;
4214 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
4216 start += ALIGN(offset, blocksize);
4220 lock_extent_bits(tree, start, end, &cached_state);
4221 wait_on_page_writeback(page);
4222 clear_extent_bit(tree, start, end,
4223 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
4224 EXTENT_DO_ACCOUNTING,
4225 1, 1, &cached_state, GFP_NOFS);
4230 * a helper for releasepage, this tests for areas of the page that
4231 * are locked or under IO and drops the related state bits if it is safe
4234 static int try_release_extent_state(struct extent_map_tree *map,
4235 struct extent_io_tree *tree,
4236 struct page *page, gfp_t mask)
4238 u64 start = page_offset(page);
4239 u64 end = start + PAGE_SIZE - 1;
4242 if (test_range_bit(tree, start, end,
4243 EXTENT_IOBITS, 0, NULL))
4246 if ((mask & GFP_NOFS) == GFP_NOFS)
4249 * at this point we can safely clear everything except the
4250 * locked bit and the nodatasum bit
4252 ret = clear_extent_bit(tree, start, end,
4253 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4256 /* if clear_extent_bit failed for enomem reasons,
4257 * we can't allow the release to continue.
4268 * a helper for releasepage. As long as there are no locked extents
4269 * in the range corresponding to the page, both state records and extent
4270 * map records are removed
4272 int try_release_extent_mapping(struct extent_map_tree *map,
4273 struct extent_io_tree *tree, struct page *page,
4276 struct extent_map *em;
4277 u64 start = page_offset(page);
4278 u64 end = start + PAGE_SIZE - 1;
4280 if (gfpflags_allow_blocking(mask) &&
4281 page->mapping->host->i_size > SZ_16M) {
4283 while (start <= end) {
4284 len = end - start + 1;
4285 write_lock(&map->lock);
4286 em = lookup_extent_mapping(map, start, len);
4288 write_unlock(&map->lock);
4291 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
4292 em->start != start) {
4293 write_unlock(&map->lock);
4294 free_extent_map(em);
4297 if (!test_range_bit(tree, em->start,
4298 extent_map_end(em) - 1,
4299 EXTENT_LOCKED | EXTENT_WRITEBACK,
4301 remove_extent_mapping(map, em);
4302 /* once for the rb tree */
4303 free_extent_map(em);
4305 start = extent_map_end(em);
4306 write_unlock(&map->lock);
4309 free_extent_map(em);
4312 return try_release_extent_state(map, tree, page, mask);
4316 * helper function for fiemap, which doesn't want to see any holes.
4317 * This maps until we find something past 'last'
4319 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4322 get_extent_t *get_extent)
4324 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
4325 struct extent_map *em;
4332 len = last - offset;
4335 len = ALIGN(len, sectorsize);
4336 em = get_extent(inode, NULL, 0, offset, len, 0);
4337 if (IS_ERR_OR_NULL(em))
4340 /* if this isn't a hole return it */
4341 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
4342 em->block_start != EXTENT_MAP_HOLE) {
4346 /* this is a hole, advance to the next extent */
4347 offset = extent_map_end(em);
4348 free_extent_map(em);
4355 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4356 __u64 start, __u64 len, get_extent_t *get_extent)
4360 u64 max = start + len;
4364 u64 last_for_get_extent = 0;
4366 u64 isize = i_size_read(inode);
4367 struct btrfs_key found_key;
4368 struct extent_map *em = NULL;
4369 struct extent_state *cached_state = NULL;
4370 struct btrfs_path *path;
4371 struct btrfs_root *root = BTRFS_I(inode)->root;
4380 path = btrfs_alloc_path();
4383 path->leave_spinning = 1;
4385 start = round_down(start, BTRFS_I(inode)->root->sectorsize);
4386 len = round_up(max, BTRFS_I(inode)->root->sectorsize) - start;
4389 * lookup the last file extent. We're not using i_size here
4390 * because there might be preallocation past i_size
4392 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), -1,
4395 btrfs_free_path(path);
4404 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4405 found_type = found_key.type;
4407 /* No extents, but there might be delalloc bits */
4408 if (found_key.objectid != btrfs_ino(inode) ||
4409 found_type != BTRFS_EXTENT_DATA_KEY) {
4410 /* have to trust i_size as the end */
4412 last_for_get_extent = isize;
4415 * remember the start of the last extent. There are a
4416 * bunch of different factors that go into the length of the
4417 * extent, so its much less complex to remember where it started
4419 last = found_key.offset;
4420 last_for_get_extent = last + 1;
4422 btrfs_release_path(path);
4425 * we might have some extents allocated but more delalloc past those
4426 * extents. so, we trust isize unless the start of the last extent is
4431 last_for_get_extent = isize;
4434 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4437 em = get_extent_skip_holes(inode, start, last_for_get_extent,
4447 u64 offset_in_extent = 0;
4449 /* break if the extent we found is outside the range */
4450 if (em->start >= max || extent_map_end(em) < off)
4454 * get_extent may return an extent that starts before our
4455 * requested range. We have to make sure the ranges
4456 * we return to fiemap always move forward and don't
4457 * overlap, so adjust the offsets here
4459 em_start = max(em->start, off);
4462 * record the offset from the start of the extent
4463 * for adjusting the disk offset below. Only do this if the
4464 * extent isn't compressed since our in ram offset may be past
4465 * what we have actually allocated on disk.
4467 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4468 offset_in_extent = em_start - em->start;
4469 em_end = extent_map_end(em);
4470 em_len = em_end - em_start;
4475 * bump off for our next call to get_extent
4477 off = extent_map_end(em);
4481 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4483 flags |= FIEMAP_EXTENT_LAST;
4484 } else if (em->block_start == EXTENT_MAP_INLINE) {
4485 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4486 FIEMAP_EXTENT_NOT_ALIGNED);
4487 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4488 flags |= (FIEMAP_EXTENT_DELALLOC |
4489 FIEMAP_EXTENT_UNKNOWN);
4490 } else if (fieinfo->fi_extents_max) {
4491 struct btrfs_trans_handle *trans;
4493 u64 bytenr = em->block_start -
4494 (em->start - em->orig_start);
4496 disko = em->block_start + offset_in_extent;
4499 * We need a trans handle to get delayed refs
4501 trans = btrfs_join_transaction(root);
4503 * It's OK if we can't start a trans we can still check
4510 * As btrfs supports shared space, this information
4511 * can be exported to userspace tools via
4512 * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
4513 * then we're just getting a count and we can skip the
4516 ret = btrfs_check_shared(trans, root->fs_info,
4518 btrfs_ino(inode), bytenr);
4520 btrfs_end_transaction(trans, root);
4524 flags |= FIEMAP_EXTENT_SHARED;
4527 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4528 flags |= FIEMAP_EXTENT_ENCODED;
4529 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4530 flags |= FIEMAP_EXTENT_UNWRITTEN;
4532 free_extent_map(em);
4534 if ((em_start >= last) || em_len == (u64)-1 ||
4535 (last == (u64)-1 && isize <= em_end)) {
4536 flags |= FIEMAP_EXTENT_LAST;
4540 /* now scan forward to see if this is really the last extent. */
4541 em = get_extent_skip_holes(inode, off, last_for_get_extent,
4548 flags |= FIEMAP_EXTENT_LAST;
4551 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
4560 free_extent_map(em);
4562 btrfs_free_path(path);
4563 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4564 &cached_state, GFP_NOFS);
4568 static void __free_extent_buffer(struct extent_buffer *eb)
4570 btrfs_leak_debug_del(&eb->leak_list);
4571 kmem_cache_free(extent_buffer_cache, eb);
4574 int extent_buffer_under_io(struct extent_buffer *eb)
4576 return (atomic_read(&eb->io_pages) ||
4577 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4578 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4582 * Helper for releasing extent buffer page.
4584 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb)
4586 unsigned long index;
4588 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4590 BUG_ON(extent_buffer_under_io(eb));
4592 index = num_extent_pages(eb->start, eb->len);
4598 page = eb->pages[index];
4602 spin_lock(&page->mapping->private_lock);
4604 * We do this since we'll remove the pages after we've
4605 * removed the eb from the radix tree, so we could race
4606 * and have this page now attached to the new eb. So
4607 * only clear page_private if it's still connected to
4610 if (PagePrivate(page) &&
4611 page->private == (unsigned long)eb) {
4612 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4613 BUG_ON(PageDirty(page));
4614 BUG_ON(PageWriteback(page));
4616 * We need to make sure we haven't be attached
4619 ClearPagePrivate(page);
4620 set_page_private(page, 0);
4621 /* One for the page private */
4626 spin_unlock(&page->mapping->private_lock);
4628 /* One for when we allocated the page */
4630 } while (index != 0);
4634 * Helper for releasing the extent buffer.
4636 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4638 btrfs_release_extent_buffer_page(eb);
4639 __free_extent_buffer(eb);
4642 static struct extent_buffer *
4643 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
4646 struct extent_buffer *eb = NULL;
4648 eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
4651 eb->fs_info = fs_info;
4653 rwlock_init(&eb->lock);
4654 atomic_set(&eb->write_locks, 0);
4655 atomic_set(&eb->read_locks, 0);
4656 atomic_set(&eb->blocking_readers, 0);
4657 atomic_set(&eb->blocking_writers, 0);
4658 atomic_set(&eb->spinning_readers, 0);
4659 atomic_set(&eb->spinning_writers, 0);
4660 eb->lock_nested = 0;
4661 init_waitqueue_head(&eb->write_lock_wq);
4662 init_waitqueue_head(&eb->read_lock_wq);
4664 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4666 spin_lock_init(&eb->refs_lock);
4667 atomic_set(&eb->refs, 1);
4668 atomic_set(&eb->io_pages, 0);
4671 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4673 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4674 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4675 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4680 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4684 struct extent_buffer *new;
4685 unsigned long num_pages = num_extent_pages(src->start, src->len);
4687 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
4691 for (i = 0; i < num_pages; i++) {
4692 p = alloc_page(GFP_NOFS);
4694 btrfs_release_extent_buffer(new);
4697 attach_extent_buffer_page(new, p);
4698 WARN_ON(PageDirty(p));
4703 copy_extent_buffer(new, src, 0, 0, src->len);
4704 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4705 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4710 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4711 u64 start, unsigned long len)
4713 struct extent_buffer *eb;
4714 unsigned long num_pages;
4717 num_pages = num_extent_pages(start, len);
4719 eb = __alloc_extent_buffer(fs_info, start, len);
4723 for (i = 0; i < num_pages; i++) {
4724 eb->pages[i] = alloc_page(GFP_NOFS);
4728 set_extent_buffer_uptodate(eb);
4729 btrfs_set_header_nritems(eb, 0);
4730 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4735 __free_page(eb->pages[i - 1]);
4736 __free_extent_buffer(eb);
4740 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
4741 u64 start, u32 nodesize)
4747 * Called only from tests that don't always have a fs_info
4752 len = fs_info->tree_root->nodesize;
4755 return __alloc_dummy_extent_buffer(fs_info, start, len);
4758 static void check_buffer_tree_ref(struct extent_buffer *eb)
4761 /* the ref bit is tricky. We have to make sure it is set
4762 * if we have the buffer dirty. Otherwise the
4763 * code to free a buffer can end up dropping a dirty
4766 * Once the ref bit is set, it won't go away while the
4767 * buffer is dirty or in writeback, and it also won't
4768 * go away while we have the reference count on the
4771 * We can't just set the ref bit without bumping the
4772 * ref on the eb because free_extent_buffer might
4773 * see the ref bit and try to clear it. If this happens
4774 * free_extent_buffer might end up dropping our original
4775 * ref by mistake and freeing the page before we are able
4776 * to add one more ref.
4778 * So bump the ref count first, then set the bit. If someone
4779 * beat us to it, drop the ref we added.
4781 refs = atomic_read(&eb->refs);
4782 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4785 spin_lock(&eb->refs_lock);
4786 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4787 atomic_inc(&eb->refs);
4788 spin_unlock(&eb->refs_lock);
4791 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
4792 struct page *accessed)
4794 unsigned long num_pages, i;
4796 check_buffer_tree_ref(eb);
4798 num_pages = num_extent_pages(eb->start, eb->len);
4799 for (i = 0; i < num_pages; i++) {
4800 struct page *p = eb->pages[i];
4803 mark_page_accessed(p);
4807 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
4810 struct extent_buffer *eb;
4813 eb = radix_tree_lookup(&fs_info->buffer_radix,
4814 start >> PAGE_SHIFT);
4815 if (eb && atomic_inc_not_zero(&eb->refs)) {
4818 * Lock our eb's refs_lock to avoid races with
4819 * free_extent_buffer. When we get our eb it might be flagged
4820 * with EXTENT_BUFFER_STALE and another task running
4821 * free_extent_buffer might have seen that flag set,
4822 * eb->refs == 2, that the buffer isn't under IO (dirty and
4823 * writeback flags not set) and it's still in the tree (flag
4824 * EXTENT_BUFFER_TREE_REF set), therefore being in the process
4825 * of decrementing the extent buffer's reference count twice.
4826 * So here we could race and increment the eb's reference count,
4827 * clear its stale flag, mark it as dirty and drop our reference
4828 * before the other task finishes executing free_extent_buffer,
4829 * which would later result in an attempt to free an extent
4830 * buffer that is dirty.
4832 if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
4833 spin_lock(&eb->refs_lock);
4834 spin_unlock(&eb->refs_lock);
4836 mark_extent_buffer_accessed(eb, NULL);
4844 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4845 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
4846 u64 start, u32 nodesize)
4848 struct extent_buffer *eb, *exists = NULL;
4851 eb = find_extent_buffer(fs_info, start);
4854 eb = alloc_dummy_extent_buffer(fs_info, start, nodesize);
4857 eb->fs_info = fs_info;
4859 ret = radix_tree_preload(GFP_NOFS);
4862 spin_lock(&fs_info->buffer_lock);
4863 ret = radix_tree_insert(&fs_info->buffer_radix,
4864 start >> PAGE_SHIFT, eb);
4865 spin_unlock(&fs_info->buffer_lock);
4866 radix_tree_preload_end();
4867 if (ret == -EEXIST) {
4868 exists = find_extent_buffer(fs_info, start);
4874 check_buffer_tree_ref(eb);
4875 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4878 * We will free dummy extent buffer's if they come into
4879 * free_extent_buffer with a ref count of 2, but if we are using this we
4880 * want the buffers to stay in memory until we're done with them, so
4881 * bump the ref count again.
4883 atomic_inc(&eb->refs);
4886 btrfs_release_extent_buffer(eb);
4891 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
4894 unsigned long len = fs_info->tree_root->nodesize;
4895 unsigned long num_pages = num_extent_pages(start, len);
4897 unsigned long index = start >> PAGE_SHIFT;
4898 struct extent_buffer *eb;
4899 struct extent_buffer *exists = NULL;
4901 struct address_space *mapping = fs_info->btree_inode->i_mapping;
4905 if (!IS_ALIGNED(start, fs_info->tree_root->sectorsize)) {
4906 btrfs_err(fs_info, "bad tree block start %llu", start);
4907 return ERR_PTR(-EINVAL);
4910 eb = find_extent_buffer(fs_info, start);
4914 eb = __alloc_extent_buffer(fs_info, start, len);
4916 return ERR_PTR(-ENOMEM);
4918 for (i = 0; i < num_pages; i++, index++) {
4919 p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
4921 exists = ERR_PTR(-ENOMEM);
4925 spin_lock(&mapping->private_lock);
4926 if (PagePrivate(p)) {
4928 * We could have already allocated an eb for this page
4929 * and attached one so lets see if we can get a ref on
4930 * the existing eb, and if we can we know it's good and
4931 * we can just return that one, else we know we can just
4932 * overwrite page->private.
4934 exists = (struct extent_buffer *)p->private;
4935 if (atomic_inc_not_zero(&exists->refs)) {
4936 spin_unlock(&mapping->private_lock);
4939 mark_extent_buffer_accessed(exists, p);
4945 * Do this so attach doesn't complain and we need to
4946 * drop the ref the old guy had.
4948 ClearPagePrivate(p);
4949 WARN_ON(PageDirty(p));
4952 attach_extent_buffer_page(eb, p);
4953 spin_unlock(&mapping->private_lock);
4954 WARN_ON(PageDirty(p));
4956 if (!PageUptodate(p))
4960 * see below about how we avoid a nasty race with release page
4961 * and why we unlock later
4965 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4967 ret = radix_tree_preload(GFP_NOFS);
4969 exists = ERR_PTR(ret);
4973 spin_lock(&fs_info->buffer_lock);
4974 ret = radix_tree_insert(&fs_info->buffer_radix,
4975 start >> PAGE_SHIFT, eb);
4976 spin_unlock(&fs_info->buffer_lock);
4977 radix_tree_preload_end();
4978 if (ret == -EEXIST) {
4979 exists = find_extent_buffer(fs_info, start);
4985 /* add one reference for the tree */
4986 check_buffer_tree_ref(eb);
4987 set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
4990 * there is a race where release page may have
4991 * tried to find this extent buffer in the radix
4992 * but failed. It will tell the VM it is safe to
4993 * reclaim the, and it will clear the page private bit.
4994 * We must make sure to set the page private bit properly
4995 * after the extent buffer is in the radix tree so
4996 * it doesn't get lost
4998 SetPageChecked(eb->pages[0]);
4999 for (i = 1; i < num_pages; i++) {
5001 ClearPageChecked(p);
5004 unlock_page(eb->pages[0]);
5008 WARN_ON(!atomic_dec_and_test(&eb->refs));
5009 for (i = 0; i < num_pages; i++) {
5011 unlock_page(eb->pages[i]);
5014 btrfs_release_extent_buffer(eb);
5018 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
5020 struct extent_buffer *eb =
5021 container_of(head, struct extent_buffer, rcu_head);
5023 __free_extent_buffer(eb);
5026 /* Expects to have eb->eb_lock already held */
5027 static int release_extent_buffer(struct extent_buffer *eb)
5029 WARN_ON(atomic_read(&eb->refs) == 0);
5030 if (atomic_dec_and_test(&eb->refs)) {
5031 if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
5032 struct btrfs_fs_info *fs_info = eb->fs_info;
5034 spin_unlock(&eb->refs_lock);
5036 spin_lock(&fs_info->buffer_lock);
5037 radix_tree_delete(&fs_info->buffer_radix,
5038 eb->start >> PAGE_SHIFT);
5039 spin_unlock(&fs_info->buffer_lock);
5041 spin_unlock(&eb->refs_lock);
5044 /* Should be safe to release our pages at this point */
5045 btrfs_release_extent_buffer_page(eb);
5046 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5047 if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) {
5048 __free_extent_buffer(eb);
5052 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
5055 spin_unlock(&eb->refs_lock);
5060 void free_extent_buffer(struct extent_buffer *eb)
5068 refs = atomic_read(&eb->refs);
5071 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
5076 spin_lock(&eb->refs_lock);
5077 if (atomic_read(&eb->refs) == 2 &&
5078 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
5079 atomic_dec(&eb->refs);
5081 if (atomic_read(&eb->refs) == 2 &&
5082 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
5083 !extent_buffer_under_io(eb) &&
5084 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5085 atomic_dec(&eb->refs);
5088 * I know this is terrible, but it's temporary until we stop tracking
5089 * the uptodate bits and such for the extent buffers.
5091 release_extent_buffer(eb);
5094 void free_extent_buffer_stale(struct extent_buffer *eb)
5099 spin_lock(&eb->refs_lock);
5100 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
5102 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
5103 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
5104 atomic_dec(&eb->refs);
5105 release_extent_buffer(eb);
5108 void clear_extent_buffer_dirty(struct extent_buffer *eb)
5111 unsigned long num_pages;
5114 num_pages = num_extent_pages(eb->start, eb->len);
5116 for (i = 0; i < num_pages; i++) {
5117 page = eb->pages[i];
5118 if (!PageDirty(page))
5122 WARN_ON(!PagePrivate(page));
5124 clear_page_dirty_for_io(page);
5125 spin_lock_irq(&page->mapping->tree_lock);
5126 if (!PageDirty(page)) {
5127 radix_tree_tag_clear(&page->mapping->page_tree,
5129 PAGECACHE_TAG_DIRTY);
5131 spin_unlock_irq(&page->mapping->tree_lock);
5132 ClearPageError(page);
5135 WARN_ON(atomic_read(&eb->refs) == 0);
5138 int set_extent_buffer_dirty(struct extent_buffer *eb)
5141 unsigned long num_pages;
5144 check_buffer_tree_ref(eb);
5146 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
5148 num_pages = num_extent_pages(eb->start, eb->len);
5149 WARN_ON(atomic_read(&eb->refs) == 0);
5150 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
5152 for (i = 0; i < num_pages; i++)
5153 set_page_dirty(eb->pages[i]);
5157 void clear_extent_buffer_uptodate(struct extent_buffer *eb)
5161 unsigned long num_pages;
5163 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5164 num_pages = num_extent_pages(eb->start, eb->len);
5165 for (i = 0; i < num_pages; i++) {
5166 page = eb->pages[i];
5168 ClearPageUptodate(page);
5172 void set_extent_buffer_uptodate(struct extent_buffer *eb)
5176 unsigned long num_pages;
5178 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5179 num_pages = num_extent_pages(eb->start, eb->len);
5180 for (i = 0; i < num_pages; i++) {
5181 page = eb->pages[i];
5182 SetPageUptodate(page);
5186 int extent_buffer_uptodate(struct extent_buffer *eb)
5188 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5191 int read_extent_buffer_pages(struct extent_io_tree *tree,
5192 struct extent_buffer *eb, u64 start, int wait,
5193 get_extent_t *get_extent, int mirror_num)
5196 unsigned long start_i;
5200 int locked_pages = 0;
5201 int all_uptodate = 1;
5202 unsigned long num_pages;
5203 unsigned long num_reads = 0;
5204 struct bio *bio = NULL;
5205 unsigned long bio_flags = 0;
5207 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
5211 WARN_ON(start < eb->start);
5212 start_i = (start >> PAGE_SHIFT) -
5213 (eb->start >> PAGE_SHIFT);
5218 num_pages = num_extent_pages(eb->start, eb->len);
5219 for (i = start_i; i < num_pages; i++) {
5220 page = eb->pages[i];
5221 if (wait == WAIT_NONE) {
5222 if (!trylock_page(page))
5230 * We need to firstly lock all pages to make sure that
5231 * the uptodate bit of our pages won't be affected by
5232 * clear_extent_buffer_uptodate().
5234 for (i = start_i; i < num_pages; i++) {
5235 page = eb->pages[i];
5236 if (!PageUptodate(page)) {
5244 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
5248 clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
5249 eb->read_mirror = 0;
5250 atomic_set(&eb->io_pages, num_reads);
5251 for (i = start_i; i < num_pages; i++) {
5252 page = eb->pages[i];
5254 if (!PageUptodate(page)) {
5256 atomic_dec(&eb->io_pages);
5261 ClearPageError(page);
5262 err = __extent_read_full_page(tree, page,
5264 mirror_num, &bio_flags,
5269 * We use &bio in above __extent_read_full_page,
5270 * so we ensure that if it returns error, the
5271 * current page fails to add itself to bio and
5272 * it's been unlocked.
5274 * We must dec io_pages by ourselves.
5276 atomic_dec(&eb->io_pages);
5284 err = submit_one_bio(bio, mirror_num, bio_flags);
5289 if (ret || wait != WAIT_COMPLETE)
5292 for (i = start_i; i < num_pages; i++) {
5293 page = eb->pages[i];
5294 wait_on_page_locked(page);
5295 if (!PageUptodate(page))
5303 while (locked_pages > 0) {
5304 page = eb->pages[i];
5312 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
5313 unsigned long start,
5320 char *dst = (char *)dstv;
5321 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5322 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5324 WARN_ON(start > eb->len);
5325 WARN_ON(start + len > eb->start + eb->len);
5327 offset = (start_offset + start) & (PAGE_SIZE - 1);
5330 page = eb->pages[i];
5332 cur = min(len, (PAGE_SIZE - offset));
5333 kaddr = page_address(page);
5334 memcpy(dst, kaddr + offset, cur);
5343 int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv,
5344 unsigned long start,
5351 char __user *dst = (char __user *)dstv;
5352 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5353 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5356 WARN_ON(start > eb->len);
5357 WARN_ON(start + len > eb->start + eb->len);
5359 offset = (start_offset + start) & (PAGE_SIZE - 1);
5362 page = eb->pages[i];
5364 cur = min(len, (PAGE_SIZE - offset));
5365 kaddr = page_address(page);
5366 if (copy_to_user(dst, kaddr + offset, cur)) {
5381 * return 0 if the item is found within a page.
5382 * return 1 if the item spans two pages.
5383 * return -EINVAL otherwise.
5385 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
5386 unsigned long min_len, char **map,
5387 unsigned long *map_start,
5388 unsigned long *map_len)
5390 size_t offset = start & (PAGE_SIZE - 1);
5393 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5394 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5395 unsigned long end_i = (start_offset + start + min_len - 1) >>
5402 offset = start_offset;
5406 *map_start = ((u64)i << PAGE_SHIFT) - start_offset;
5409 if (start + min_len > eb->len) {
5410 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
5412 eb->start, eb->len, start, min_len);
5417 kaddr = page_address(p);
5418 *map = kaddr + offset;
5419 *map_len = PAGE_SIZE - offset;
5423 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
5424 unsigned long start,
5431 char *ptr = (char *)ptrv;
5432 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5433 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5436 WARN_ON(start > eb->len);
5437 WARN_ON(start + len > eb->start + eb->len);
5439 offset = (start_offset + start) & (PAGE_SIZE - 1);
5442 page = eb->pages[i];
5444 cur = min(len, (PAGE_SIZE - offset));
5446 kaddr = page_address(page);
5447 ret = memcmp(ptr, kaddr + offset, cur);
5459 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
5460 unsigned long start, unsigned long len)
5466 char *src = (char *)srcv;
5467 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5468 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5470 WARN_ON(start > eb->len);
5471 WARN_ON(start + len > eb->start + eb->len);
5473 offset = (start_offset + start) & (PAGE_SIZE - 1);
5476 page = eb->pages[i];
5477 WARN_ON(!PageUptodate(page));
5479 cur = min(len, PAGE_SIZE - offset);
5480 kaddr = page_address(page);
5481 memcpy(kaddr + offset, src, cur);
5490 void memset_extent_buffer(struct extent_buffer *eb, char c,
5491 unsigned long start, unsigned long len)
5497 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5498 unsigned long i = (start_offset + start) >> PAGE_SHIFT;
5500 WARN_ON(start > eb->len);
5501 WARN_ON(start + len > eb->start + eb->len);
5503 offset = (start_offset + start) & (PAGE_SIZE - 1);
5506 page = eb->pages[i];
5507 WARN_ON(!PageUptodate(page));
5509 cur = min(len, PAGE_SIZE - offset);
5510 kaddr = page_address(page);
5511 memset(kaddr + offset, c, cur);
5519 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5520 unsigned long dst_offset, unsigned long src_offset,
5523 u64 dst_len = dst->len;
5528 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5529 unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
5531 WARN_ON(src->len != dst_len);
5533 offset = (start_offset + dst_offset) &
5537 page = dst->pages[i];
5538 WARN_ON(!PageUptodate(page));
5540 cur = min(len, (unsigned long)(PAGE_SIZE - offset));
5542 kaddr = page_address(page);
5543 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5553 * The extent buffer bitmap operations are done with byte granularity because
5554 * bitmap items are not guaranteed to be aligned to a word and therefore a
5555 * single word in a bitmap may straddle two pages in the extent buffer.
5557 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
5558 #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
5559 #define BITMAP_FIRST_BYTE_MASK(start) \
5560 ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
5561 #define BITMAP_LAST_BYTE_MASK(nbits) \
5562 (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
5565 * eb_bitmap_offset() - calculate the page and offset of the byte containing the
5567 * @eb: the extent buffer
5568 * @start: offset of the bitmap item in the extent buffer
5570 * @page_index: return index of the page in the extent buffer that contains the
5572 * @page_offset: return offset into the page given by page_index
5574 * This helper hides the ugliness of finding the byte in an extent buffer which
5575 * contains a given bit.
5577 static inline void eb_bitmap_offset(struct extent_buffer *eb,
5578 unsigned long start, unsigned long nr,
5579 unsigned long *page_index,
5580 size_t *page_offset)
5582 size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
5583 size_t byte_offset = BIT_BYTE(nr);
5587 * The byte we want is the offset of the extent buffer + the offset of
5588 * the bitmap item in the extent buffer + the offset of the byte in the
5591 offset = start_offset + start + byte_offset;
5593 *page_index = offset >> PAGE_SHIFT;
5594 *page_offset = offset & (PAGE_SIZE - 1);
5598 * extent_buffer_test_bit - determine whether a bit in a bitmap item is set
5599 * @eb: the extent buffer
5600 * @start: offset of the bitmap item in the extent buffer
5601 * @nr: bit number to test
5603 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
5611 eb_bitmap_offset(eb, start, nr, &i, &offset);
5612 page = eb->pages[i];
5613 WARN_ON(!PageUptodate(page));
5614 kaddr = page_address(page);
5615 return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
5619 * extent_buffer_bitmap_set - set an area of a bitmap
5620 * @eb: the extent buffer
5621 * @start: offset of the bitmap item in the extent buffer
5622 * @pos: bit number of the first bit
5623 * @len: number of bits to set
5625 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
5626 unsigned long pos, unsigned long len)
5632 const unsigned int size = pos + len;
5633 int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5634 unsigned int mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
5636 eb_bitmap_offset(eb, start, pos, &i, &offset);
5637 page = eb->pages[i];
5638 WARN_ON(!PageUptodate(page));
5639 kaddr = page_address(page);
5641 while (len >= bits_to_set) {
5642 kaddr[offset] |= mask_to_set;
5644 bits_to_set = BITS_PER_BYTE;
5646 if (++offset >= PAGE_SIZE && len > 0) {
5648 page = eb->pages[++i];
5649 WARN_ON(!PageUptodate(page));
5650 kaddr = page_address(page);
5654 mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
5655 kaddr[offset] |= mask_to_set;
5661 * extent_buffer_bitmap_clear - clear an area of a bitmap
5662 * @eb: the extent buffer
5663 * @start: offset of the bitmap item in the extent buffer
5664 * @pos: bit number of the first bit
5665 * @len: number of bits to clear
5667 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
5668 unsigned long pos, unsigned long len)
5674 const unsigned int size = pos + len;
5675 int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
5676 unsigned int mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
5678 eb_bitmap_offset(eb, start, pos, &i, &offset);
5679 page = eb->pages[i];
5680 WARN_ON(!PageUptodate(page));
5681 kaddr = page_address(page);
5683 while (len >= bits_to_clear) {
5684 kaddr[offset] &= ~mask_to_clear;
5685 len -= bits_to_clear;
5686 bits_to_clear = BITS_PER_BYTE;
5687 mask_to_clear = ~0U;
5688 if (++offset >= PAGE_SIZE && len > 0) {
5690 page = eb->pages[++i];
5691 WARN_ON(!PageUptodate(page));
5692 kaddr = page_address(page);
5696 mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
5697 kaddr[offset] &= ~mask_to_clear;
5701 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5703 unsigned long distance = (src > dst) ? src - dst : dst - src;
5704 return distance < len;
5707 static void copy_pages(struct page *dst_page, struct page *src_page,
5708 unsigned long dst_off, unsigned long src_off,
5711 char *dst_kaddr = page_address(dst_page);
5713 int must_memmove = 0;
5715 if (dst_page != src_page) {
5716 src_kaddr = page_address(src_page);
5718 src_kaddr = dst_kaddr;
5719 if (areas_overlap(src_off, dst_off, len))
5724 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5726 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5729 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5730 unsigned long src_offset, unsigned long len)
5733 size_t dst_off_in_page;
5734 size_t src_off_in_page;
5735 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5736 unsigned long dst_i;
5737 unsigned long src_i;
5739 if (src_offset + len > dst->len) {
5740 btrfs_err(dst->fs_info,
5741 "memmove bogus src_offset %lu move "
5742 "len %lu dst len %lu", src_offset, len, dst->len);
5745 if (dst_offset + len > dst->len) {
5746 btrfs_err(dst->fs_info,
5747 "memmove bogus dst_offset %lu move "
5748 "len %lu dst len %lu", dst_offset, len, dst->len);
5753 dst_off_in_page = (start_offset + dst_offset) &
5755 src_off_in_page = (start_offset + src_offset) &
5758 dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
5759 src_i = (start_offset + src_offset) >> PAGE_SHIFT;
5761 cur = min(len, (unsigned long)(PAGE_SIZE -
5763 cur = min_t(unsigned long, cur,
5764 (unsigned long)(PAGE_SIZE - dst_off_in_page));
5766 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5767 dst_off_in_page, src_off_in_page, cur);
5775 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5776 unsigned long src_offset, unsigned long len)
5779 size_t dst_off_in_page;
5780 size_t src_off_in_page;
5781 unsigned long dst_end = dst_offset + len - 1;
5782 unsigned long src_end = src_offset + len - 1;
5783 size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
5784 unsigned long dst_i;
5785 unsigned long src_i;
5787 if (src_offset + len > dst->len) {
5788 btrfs_err(dst->fs_info, "memmove bogus src_offset %lu move "
5789 "len %lu len %lu", src_offset, len, dst->len);
5792 if (dst_offset + len > dst->len) {
5793 btrfs_err(dst->fs_info, "memmove bogus dst_offset %lu move "
5794 "len %lu len %lu", dst_offset, len, dst->len);
5797 if (dst_offset < src_offset) {
5798 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5802 dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
5803 src_i = (start_offset + src_end) >> PAGE_SHIFT;
5805 dst_off_in_page = (start_offset + dst_end) &
5807 src_off_in_page = (start_offset + src_end) &
5810 cur = min_t(unsigned long, len, src_off_in_page + 1);
5811 cur = min(cur, dst_off_in_page + 1);
5812 copy_pages(dst->pages[dst_i], dst->pages[src_i],
5813 dst_off_in_page - cur + 1,
5814 src_off_in_page - cur + 1, cur);
5822 int try_release_extent_buffer(struct page *page)
5824 struct extent_buffer *eb;
5827 * We need to make sure nobody is attaching this page to an eb right
5830 spin_lock(&page->mapping->private_lock);
5831 if (!PagePrivate(page)) {
5832 spin_unlock(&page->mapping->private_lock);
5836 eb = (struct extent_buffer *)page->private;
5840 * This is a little awful but should be ok, we need to make sure that
5841 * the eb doesn't disappear out from under us while we're looking at
5844 spin_lock(&eb->refs_lock);
5845 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5846 spin_unlock(&eb->refs_lock);
5847 spin_unlock(&page->mapping->private_lock);
5850 spin_unlock(&page->mapping->private_lock);
5853 * If tree ref isn't set then we know the ref on this eb is a real ref,
5854 * so just return, this page will likely be freed soon anyway.
5856 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5857 spin_unlock(&eb->refs_lock);
5861 return release_extent_buffer(eb);