1 #include <linux/bitops.h>
2 #include <linux/slab.h>
6 #include <linux/pagemap.h>
7 #include <linux/page-flags.h>
8 #include <linux/module.h>
9 #include <linux/spinlock.h>
10 #include <linux/blkdev.h>
11 #include <linux/swap.h>
12 #include <linux/version.h>
13 #include <linux/writeback.h>
14 #include <linux/pagevec.h>
15 #include "extent_io.h"
16 #include "extent_map.h"
19 #include "btrfs_inode.h"
21 /* temporary define until extent_map moves out of btrfs */
22 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
23 unsigned long extra_flags,
24 void (*ctor)(void *, struct kmem_cache *,
27 static struct kmem_cache *extent_state_cache;
28 static struct kmem_cache *extent_buffer_cache;
30 static LIST_HEAD(buffers);
31 static LIST_HEAD(states);
35 static DEFINE_SPINLOCK(leak_lock);
38 #define BUFFER_LRU_MAX 64
43 struct rb_node rb_node;
46 struct extent_page_data {
48 struct extent_io_tree *tree;
49 get_extent_t *get_extent;
51 /* tells writepage not to lock the state bits for this range
52 * it still does the unlocking
57 int __init extent_io_init(void)
59 extent_state_cache = btrfs_cache_create("extent_state",
60 sizeof(struct extent_state), 0,
62 if (!extent_state_cache)
65 extent_buffer_cache = btrfs_cache_create("extent_buffers",
66 sizeof(struct extent_buffer), 0,
68 if (!extent_buffer_cache)
69 goto free_state_cache;
73 kmem_cache_destroy(extent_state_cache);
77 void extent_io_exit(void)
79 struct extent_state *state;
80 struct extent_buffer *eb;
82 while (!list_empty(&states)) {
83 state = list_entry(states.next, struct extent_state, leak_list);
84 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
85 "state %lu in tree %p refs %d\n",
86 (unsigned long long)state->start,
87 (unsigned long long)state->end,
88 state->state, state->tree, atomic_read(&state->refs));
89 list_del(&state->leak_list);
90 kmem_cache_free(extent_state_cache, state);
94 while (!list_empty(&buffers)) {
95 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
96 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
97 "refs %d\n", (unsigned long long)eb->start,
98 eb->len, atomic_read(&eb->refs));
99 list_del(&eb->leak_list);
100 kmem_cache_free(extent_buffer_cache, eb);
102 if (extent_state_cache)
103 kmem_cache_destroy(extent_state_cache);
104 if (extent_buffer_cache)
105 kmem_cache_destroy(extent_buffer_cache);
108 void extent_io_tree_init(struct extent_io_tree *tree,
109 struct address_space *mapping, gfp_t mask)
111 tree->state.rb_node = NULL;
112 tree->buffer.rb_node = NULL;
114 tree->dirty_bytes = 0;
115 spin_lock_init(&tree->lock);
116 spin_lock_init(&tree->buffer_lock);
117 tree->mapping = mapping;
119 EXPORT_SYMBOL(extent_io_tree_init);
121 static struct extent_state *alloc_extent_state(gfp_t mask)
123 struct extent_state *state;
128 state = kmem_cache_alloc(extent_state_cache, mask);
135 spin_lock_irqsave(&leak_lock, flags);
136 list_add(&state->leak_list, &states);
137 spin_unlock_irqrestore(&leak_lock, flags);
139 atomic_set(&state->refs, 1);
140 init_waitqueue_head(&state->wq);
143 EXPORT_SYMBOL(alloc_extent_state);
145 static void free_extent_state(struct extent_state *state)
149 if (atomic_dec_and_test(&state->refs)) {
153 WARN_ON(state->tree);
155 spin_lock_irqsave(&leak_lock, flags);
156 list_del(&state->leak_list);
157 spin_unlock_irqrestore(&leak_lock, flags);
159 kmem_cache_free(extent_state_cache, state);
162 EXPORT_SYMBOL(free_extent_state);
164 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
165 struct rb_node *node)
167 struct rb_node **p = &root->rb_node;
168 struct rb_node *parent = NULL;
169 struct tree_entry *entry;
173 entry = rb_entry(parent, struct tree_entry, rb_node);
175 if (offset < entry->start)
177 else if (offset > entry->end)
183 entry = rb_entry(node, struct tree_entry, rb_node);
184 rb_link_node(node, parent, p);
185 rb_insert_color(node, root);
189 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
190 struct rb_node **prev_ret,
191 struct rb_node **next_ret)
193 struct rb_root *root = &tree->state;
194 struct rb_node *n = root->rb_node;
195 struct rb_node *prev = NULL;
196 struct rb_node *orig_prev = NULL;
197 struct tree_entry *entry;
198 struct tree_entry *prev_entry = NULL;
201 entry = rb_entry(n, struct tree_entry, rb_node);
205 if (offset < entry->start)
207 else if (offset > entry->end)
215 while (prev && offset > prev_entry->end) {
216 prev = rb_next(prev);
217 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
224 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
225 while (prev && offset < prev_entry->start) {
226 prev = rb_prev(prev);
227 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
234 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
237 struct rb_node *prev = NULL;
240 ret = __etree_search(tree, offset, &prev, NULL);
246 static struct extent_buffer *buffer_tree_insert(struct extent_io_tree *tree,
247 u64 offset, struct rb_node *node)
249 struct rb_root *root = &tree->buffer;
250 struct rb_node **p = &root->rb_node;
251 struct rb_node *parent = NULL;
252 struct extent_buffer *eb;
256 eb = rb_entry(parent, struct extent_buffer, rb_node);
258 if (offset < eb->start)
260 else if (offset > eb->start)
266 rb_link_node(node, parent, p);
267 rb_insert_color(node, root);
271 static struct extent_buffer *buffer_search(struct extent_io_tree *tree,
274 struct rb_root *root = &tree->buffer;
275 struct rb_node *n = root->rb_node;
276 struct extent_buffer *eb;
279 eb = rb_entry(n, struct extent_buffer, rb_node);
280 if (offset < eb->start)
282 else if (offset > eb->start)
291 * utility function to look for merge candidates inside a given range.
292 * Any extents with matching state are merged together into a single
293 * extent in the tree. Extents with EXTENT_IO in their state field
294 * are not merged because the end_io handlers need to be able to do
295 * operations on them without sleeping (or doing allocations/splits).
297 * This should be called with the tree lock held.
299 static int merge_state(struct extent_io_tree *tree,
300 struct extent_state *state)
302 struct extent_state *other;
303 struct rb_node *other_node;
305 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
308 other_node = rb_prev(&state->rb_node);
310 other = rb_entry(other_node, struct extent_state, rb_node);
311 if (other->end == state->start - 1 &&
312 other->state == state->state) {
313 state->start = other->start;
315 rb_erase(&other->rb_node, &tree->state);
316 free_extent_state(other);
319 other_node = rb_next(&state->rb_node);
321 other = rb_entry(other_node, struct extent_state, rb_node);
322 if (other->start == state->end + 1 &&
323 other->state == state->state) {
324 other->start = state->start;
326 rb_erase(&state->rb_node, &tree->state);
327 free_extent_state(state);
333 static void set_state_cb(struct extent_io_tree *tree,
334 struct extent_state *state,
337 if (tree->ops && tree->ops->set_bit_hook) {
338 tree->ops->set_bit_hook(tree->mapping->host, state->start,
339 state->end, state->state, bits);
343 static void clear_state_cb(struct extent_io_tree *tree,
344 struct extent_state *state,
347 if (tree->ops && tree->ops->clear_bit_hook) {
348 tree->ops->clear_bit_hook(tree->mapping->host, state->start,
349 state->end, state->state, bits);
354 * insert an extent_state struct into the tree. 'bits' are set on the
355 * struct before it is inserted.
357 * This may return -EEXIST if the extent is already there, in which case the
358 * state struct is freed.
360 * The tree lock is not taken internally. This is a utility function and
361 * probably isn't what you want to call (see set/clear_extent_bit).
363 static int insert_state(struct extent_io_tree *tree,
364 struct extent_state *state, u64 start, u64 end,
367 struct rb_node *node;
370 printk(KERN_ERR "btrfs end < start %llu %llu\n",
371 (unsigned long long)end,
372 (unsigned long long)start);
375 if (bits & EXTENT_DIRTY)
376 tree->dirty_bytes += end - start + 1;
377 set_state_cb(tree, state, bits);
378 state->state |= bits;
379 state->start = start;
381 node = tree_insert(&tree->state, end, &state->rb_node);
383 struct extent_state *found;
384 found = rb_entry(node, struct extent_state, rb_node);
385 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
386 "%llu %llu\n", (unsigned long long)found->start,
387 (unsigned long long)found->end,
388 (unsigned long long)start, (unsigned long long)end);
389 free_extent_state(state);
393 merge_state(tree, state);
398 * split a given extent state struct in two, inserting the preallocated
399 * struct 'prealloc' as the newly created second half. 'split' indicates an
400 * offset inside 'orig' where it should be split.
403 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
404 * are two extent state structs in the tree:
405 * prealloc: [orig->start, split - 1]
406 * orig: [ split, orig->end ]
408 * The tree locks are not taken by this function. They need to be held
411 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
412 struct extent_state *prealloc, u64 split)
414 struct rb_node *node;
415 prealloc->start = orig->start;
416 prealloc->end = split - 1;
417 prealloc->state = orig->state;
420 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
422 struct extent_state *found;
423 found = rb_entry(node, struct extent_state, rb_node);
424 free_extent_state(prealloc);
427 prealloc->tree = tree;
432 * utility function to clear some bits in an extent state struct.
433 * it will optionally wake up any one waiting on this state (wake == 1), or
434 * forcibly remove the state from the tree (delete == 1).
436 * If no bits are set on the state struct after clearing things, the
437 * struct is freed and removed from the tree
439 static int clear_state_bit(struct extent_io_tree *tree,
440 struct extent_state *state, int bits, int wake,
443 int ret = state->state & bits;
445 if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
446 u64 range = state->end - state->start + 1;
447 WARN_ON(range > tree->dirty_bytes);
448 tree->dirty_bytes -= range;
450 clear_state_cb(tree, state, bits);
451 state->state &= ~bits;
454 if (delete || state->state == 0) {
456 clear_state_cb(tree, state, state->state);
457 rb_erase(&state->rb_node, &tree->state);
459 free_extent_state(state);
464 merge_state(tree, state);
470 * clear some bits on a range in the tree. This may require splitting
471 * or inserting elements in the tree, so the gfp mask is used to
472 * indicate which allocations or sleeping are allowed.
474 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
475 * the given range from the tree regardless of state (ie for truncate).
477 * the range [start, end] is inclusive.
479 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
480 * bits were already set, or zero if none of the bits were already set.
482 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
483 int bits, int wake, int delete, gfp_t mask)
485 struct extent_state *state;
486 struct extent_state *prealloc = NULL;
487 struct rb_node *node;
492 if (!prealloc && (mask & __GFP_WAIT)) {
493 prealloc = alloc_extent_state(mask);
498 spin_lock(&tree->lock);
500 * this search will find the extents that end after
503 node = tree_search(tree, start);
506 state = rb_entry(node, struct extent_state, rb_node);
507 if (state->start > end)
509 WARN_ON(state->end < start);
512 * | ---- desired range ---- |
514 * | ------------- state -------------- |
516 * We need to split the extent we found, and may flip
517 * bits on second half.
519 * If the extent we found extends past our range, we
520 * just split and search again. It'll get split again
521 * the next time though.
523 * If the extent we found is inside our range, we clear
524 * the desired bit on it.
527 if (state->start < start) {
529 prealloc = alloc_extent_state(GFP_ATOMIC);
530 err = split_state(tree, state, prealloc, start);
531 BUG_ON(err == -EEXIST);
535 if (state->end <= end) {
536 start = state->end + 1;
537 set |= clear_state_bit(tree, state, bits,
540 start = state->start;
545 * | ---- desired range ---- |
547 * We need to split the extent, and clear the bit
550 if (state->start <= end && state->end > end) {
552 prealloc = alloc_extent_state(GFP_ATOMIC);
553 err = split_state(tree, state, prealloc, end + 1);
554 BUG_ON(err == -EEXIST);
558 set |= clear_state_bit(tree, prealloc, bits,
564 start = state->end + 1;
565 set |= clear_state_bit(tree, state, bits, wake, delete);
569 spin_unlock(&tree->lock);
571 free_extent_state(prealloc);
578 spin_unlock(&tree->lock);
579 if (mask & __GFP_WAIT)
583 EXPORT_SYMBOL(clear_extent_bit);
585 static int wait_on_state(struct extent_io_tree *tree,
586 struct extent_state *state)
587 __releases(tree->lock)
588 __acquires(tree->lock)
591 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
592 spin_unlock(&tree->lock);
594 spin_lock(&tree->lock);
595 finish_wait(&state->wq, &wait);
600 * waits for one or more bits to clear on a range in the state tree.
601 * The range [start, end] is inclusive.
602 * The tree lock is taken by this function
604 int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
606 struct extent_state *state;
607 struct rb_node *node;
609 spin_lock(&tree->lock);
613 * this search will find all the extents that end after
616 node = tree_search(tree, start);
620 state = rb_entry(node, struct extent_state, rb_node);
622 if (state->start > end)
625 if (state->state & bits) {
626 start = state->start;
627 atomic_inc(&state->refs);
628 wait_on_state(tree, state);
629 free_extent_state(state);
632 start = state->end + 1;
637 if (need_resched()) {
638 spin_unlock(&tree->lock);
640 spin_lock(&tree->lock);
644 spin_unlock(&tree->lock);
647 EXPORT_SYMBOL(wait_extent_bit);
649 static void set_state_bits(struct extent_io_tree *tree,
650 struct extent_state *state,
653 if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
654 u64 range = state->end - state->start + 1;
655 tree->dirty_bytes += range;
657 set_state_cb(tree, state, bits);
658 state->state |= bits;
662 * set some bits on a range in the tree. This may require allocations
663 * or sleeping, so the gfp mask is used to indicate what is allowed.
665 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
666 * range already has the desired bits set. The start of the existing
667 * range is returned in failed_start in this case.
669 * [start, end] is inclusive
670 * This takes the tree lock.
672 static int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
673 int bits, int exclusive, u64 *failed_start,
676 struct extent_state *state;
677 struct extent_state *prealloc = NULL;
678 struct rb_node *node;
684 if (!prealloc && (mask & __GFP_WAIT)) {
685 prealloc = alloc_extent_state(mask);
690 spin_lock(&tree->lock);
692 * this search will find all the extents that end after
695 node = tree_search(tree, start);
697 err = insert_state(tree, prealloc, start, end, bits);
699 BUG_ON(err == -EEXIST);
703 state = rb_entry(node, struct extent_state, rb_node);
704 last_start = state->start;
705 last_end = state->end;
708 * | ---- desired range ---- |
711 * Just lock what we found and keep going
713 if (state->start == start && state->end <= end) {
714 set = state->state & bits;
715 if (set && exclusive) {
716 *failed_start = state->start;
720 set_state_bits(tree, state, bits);
721 start = state->end + 1;
722 merge_state(tree, state);
727 * | ---- desired range ---- |
730 * | ------------- state -------------- |
732 * We need to split the extent we found, and may flip bits on
735 * If the extent we found extends past our
736 * range, we just split and search again. It'll get split
737 * again the next time though.
739 * If the extent we found is inside our range, we set the
742 if (state->start < start) {
743 set = state->state & bits;
744 if (exclusive && set) {
745 *failed_start = start;
749 err = split_state(tree, state, prealloc, start);
750 BUG_ON(err == -EEXIST);
754 if (state->end <= end) {
755 set_state_bits(tree, state, bits);
756 start = state->end + 1;
757 merge_state(tree, state);
759 start = state->start;
764 * | ---- desired range ---- |
765 * | state | or | state |
767 * There's a hole, we need to insert something in it and
768 * ignore the extent we found.
770 if (state->start > start) {
772 if (end < last_start)
775 this_end = last_start - 1;
776 err = insert_state(tree, prealloc, start, this_end,
779 BUG_ON(err == -EEXIST);
782 start = this_end + 1;
786 * | ---- desired range ---- |
788 * We need to split the extent, and set the bit
791 if (state->start <= end && state->end > end) {
792 set = state->state & bits;
793 if (exclusive && set) {
794 *failed_start = start;
798 err = split_state(tree, state, prealloc, end + 1);
799 BUG_ON(err == -EEXIST);
801 set_state_bits(tree, prealloc, bits);
802 merge_state(tree, prealloc);
810 spin_unlock(&tree->lock);
812 free_extent_state(prealloc);
819 spin_unlock(&tree->lock);
820 if (mask & __GFP_WAIT)
824 EXPORT_SYMBOL(set_extent_bit);
826 /* wrappers around set/clear extent bit */
827 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
830 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
833 EXPORT_SYMBOL(set_extent_dirty);
835 int set_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
838 return set_extent_bit(tree, start, end, EXTENT_ORDERED, 0, NULL, mask);
840 EXPORT_SYMBOL(set_extent_ordered);
842 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
843 int bits, gfp_t mask)
845 return set_extent_bit(tree, start, end, bits, 0, NULL,
848 EXPORT_SYMBOL(set_extent_bits);
850 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
851 int bits, gfp_t mask)
853 return clear_extent_bit(tree, start, end, bits, 0, 0, mask);
855 EXPORT_SYMBOL(clear_extent_bits);
857 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
860 return set_extent_bit(tree, start, end,
861 EXTENT_DELALLOC | EXTENT_DIRTY,
864 EXPORT_SYMBOL(set_extent_delalloc);
866 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
869 return clear_extent_bit(tree, start, end,
870 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask);
872 EXPORT_SYMBOL(clear_extent_dirty);
874 int clear_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
877 return clear_extent_bit(tree, start, end, EXTENT_ORDERED, 1, 0, mask);
879 EXPORT_SYMBOL(clear_extent_ordered);
881 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
884 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
887 EXPORT_SYMBOL(set_extent_new);
889 static int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
892 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask);
895 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
898 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
901 EXPORT_SYMBOL(set_extent_uptodate);
903 static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
906 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask);
909 static int set_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
912 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK,
916 static int clear_extent_writeback(struct extent_io_tree *tree, u64 start,
919 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask);
922 int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
924 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
926 EXPORT_SYMBOL(wait_on_extent_writeback);
929 * either insert or lock state struct between start and end use mask to tell
930 * us if waiting is desired.
932 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
937 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
938 &failed_start, mask);
939 if (err == -EEXIST && (mask & __GFP_WAIT)) {
940 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
941 start = failed_start;
945 WARN_ON(start > end);
949 EXPORT_SYMBOL(lock_extent);
951 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
957 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
958 &failed_start, mask);
959 if (err == -EEXIST) {
960 if (failed_start > start)
961 clear_extent_bit(tree, start, failed_start - 1,
962 EXTENT_LOCKED, 1, 0, mask);
967 EXPORT_SYMBOL(try_lock_extent);
969 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
972 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask);
974 EXPORT_SYMBOL(unlock_extent);
977 * helper function to set pages and extents in the tree dirty
979 int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
981 unsigned long index = start >> PAGE_CACHE_SHIFT;
982 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
985 while (index <= end_index) {
986 page = find_get_page(tree->mapping, index);
988 __set_page_dirty_nobuffers(page);
989 page_cache_release(page);
992 set_extent_dirty(tree, start, end, GFP_NOFS);
995 EXPORT_SYMBOL(set_range_dirty);
998 * helper function to set both pages and extents in the tree writeback
1000 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1002 unsigned long index = start >> PAGE_CACHE_SHIFT;
1003 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1006 while (index <= end_index) {
1007 page = find_get_page(tree->mapping, index);
1009 set_page_writeback(page);
1010 page_cache_release(page);
1013 set_extent_writeback(tree, start, end, GFP_NOFS);
1018 * find the first offset in the io tree with 'bits' set. zero is
1019 * returned if we find something, and *start_ret and *end_ret are
1020 * set to reflect the state struct that was found.
1022 * If nothing was found, 1 is returned, < 0 on error
1024 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1025 u64 *start_ret, u64 *end_ret, int bits)
1027 struct rb_node *node;
1028 struct extent_state *state;
1031 spin_lock(&tree->lock);
1033 * this search will find all the extents that end after
1036 node = tree_search(tree, start);
1041 state = rb_entry(node, struct extent_state, rb_node);
1042 if (state->end >= start && (state->state & bits)) {
1043 *start_ret = state->start;
1044 *end_ret = state->end;
1048 node = rb_next(node);
1053 spin_unlock(&tree->lock);
1056 EXPORT_SYMBOL(find_first_extent_bit);
1058 /* find the first state struct with 'bits' set after 'start', and
1059 * return it. tree->lock must be held. NULL will returned if
1060 * nothing was found after 'start'
1062 struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
1063 u64 start, int bits)
1065 struct rb_node *node;
1066 struct extent_state *state;
1069 * this search will find all the extents that end after
1072 node = tree_search(tree, start);
1077 state = rb_entry(node, struct extent_state, rb_node);
1078 if (state->end >= start && (state->state & bits))
1081 node = rb_next(node);
1088 EXPORT_SYMBOL(find_first_extent_bit_state);
1091 * find a contiguous range of bytes in the file marked as delalloc, not
1092 * more than 'max_bytes'. start and end are used to return the range,
1094 * 1 is returned if we find something, 0 if nothing was in the tree
1096 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1097 u64 *start, u64 *end, u64 max_bytes)
1099 struct rb_node *node;
1100 struct extent_state *state;
1101 u64 cur_start = *start;
1103 u64 total_bytes = 0;
1105 spin_lock(&tree->lock);
1108 * this search will find all the extents that end after
1111 node = tree_search(tree, cur_start);
1119 state = rb_entry(node, struct extent_state, rb_node);
1120 if (found && (state->start != cur_start ||
1121 (state->state & EXTENT_BOUNDARY))) {
1124 if (!(state->state & EXTENT_DELALLOC)) {
1130 *start = state->start;
1133 cur_start = state->end + 1;
1134 node = rb_next(node);
1137 total_bytes += state->end - state->start + 1;
1138 if (total_bytes >= max_bytes)
1142 spin_unlock(&tree->lock);
1146 static noinline int __unlock_for_delalloc(struct inode *inode,
1147 struct page *locked_page,
1151 struct page *pages[16];
1152 unsigned long index = start >> PAGE_CACHE_SHIFT;
1153 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1154 unsigned long nr_pages = end_index - index + 1;
1157 if (index == locked_page->index && end_index == index)
1160 while (nr_pages > 0) {
1161 ret = find_get_pages_contig(inode->i_mapping, index,
1162 min_t(unsigned long, nr_pages,
1163 ARRAY_SIZE(pages)), pages);
1164 for (i = 0; i < ret; i++) {
1165 if (pages[i] != locked_page)
1166 unlock_page(pages[i]);
1167 page_cache_release(pages[i]);
1176 static noinline int lock_delalloc_pages(struct inode *inode,
1177 struct page *locked_page,
1181 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1182 unsigned long start_index = index;
1183 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1184 unsigned long pages_locked = 0;
1185 struct page *pages[16];
1186 unsigned long nrpages;
1190 /* the caller is responsible for locking the start index */
1191 if (index == locked_page->index && index == end_index)
1194 /* skip the page at the start index */
1195 nrpages = end_index - index + 1;
1196 while (nrpages > 0) {
1197 ret = find_get_pages_contig(inode->i_mapping, index,
1198 min_t(unsigned long,
1199 nrpages, ARRAY_SIZE(pages)), pages);
1204 /* now we have an array of pages, lock them all */
1205 for (i = 0; i < ret; i++) {
1207 * the caller is taking responsibility for
1210 if (pages[i] != locked_page) {
1211 lock_page(pages[i]);
1212 if (!PageDirty(pages[i]) ||
1213 pages[i]->mapping != inode->i_mapping) {
1215 unlock_page(pages[i]);
1216 page_cache_release(pages[i]);
1220 page_cache_release(pages[i]);
1229 if (ret && pages_locked) {
1230 __unlock_for_delalloc(inode, locked_page,
1232 ((u64)(start_index + pages_locked - 1)) <<
1239 * find a contiguous range of bytes in the file marked as delalloc, not
1240 * more than 'max_bytes'. start and end are used to return the range,
1242 * 1 is returned if we find something, 0 if nothing was in the tree
1244 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1245 struct extent_io_tree *tree,
1246 struct page *locked_page,
1247 u64 *start, u64 *end,
1257 /* step one, find a bunch of delalloc bytes starting at start */
1258 delalloc_start = *start;
1260 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1262 if (!found || delalloc_end <= *start) {
1263 *start = delalloc_start;
1264 *end = delalloc_end;
1269 * start comes from the offset of locked_page. We have to lock
1270 * pages in order, so we can't process delalloc bytes before
1273 if (delalloc_start < *start)
1274 delalloc_start = *start;
1277 * make sure to limit the number of pages we try to lock down
1280 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1281 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1283 /* step two, lock all the pages after the page that has start */
1284 ret = lock_delalloc_pages(inode, locked_page,
1285 delalloc_start, delalloc_end);
1286 if (ret == -EAGAIN) {
1287 /* some of the pages are gone, lets avoid looping by
1288 * shortening the size of the delalloc range we're searching
1291 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1292 max_bytes = PAGE_CACHE_SIZE - offset;
1302 /* step three, lock the state bits for the whole range */
1303 lock_extent(tree, delalloc_start, delalloc_end, GFP_NOFS);
1305 /* then test to make sure it is all still delalloc */
1306 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1307 EXTENT_DELALLOC, 1);
1309 unlock_extent(tree, delalloc_start, delalloc_end, GFP_NOFS);
1310 __unlock_for_delalloc(inode, locked_page,
1311 delalloc_start, delalloc_end);
1315 *start = delalloc_start;
1316 *end = delalloc_end;
1321 int extent_clear_unlock_delalloc(struct inode *inode,
1322 struct extent_io_tree *tree,
1323 u64 start, u64 end, struct page *locked_page,
1326 int clear_delalloc, int clear_dirty,
1331 struct page *pages[16];
1332 unsigned long index = start >> PAGE_CACHE_SHIFT;
1333 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1334 unsigned long nr_pages = end_index - index + 1;
1339 clear_bits |= EXTENT_LOCKED;
1341 clear_bits |= EXTENT_DIRTY;
1344 clear_bits |= EXTENT_DELALLOC;
1346 clear_extent_bit(tree, start, end, clear_bits, 1, 0, GFP_NOFS);
1347 if (!(unlock_pages || clear_dirty || set_writeback || end_writeback))
1350 while (nr_pages > 0) {
1351 ret = find_get_pages_contig(inode->i_mapping, index,
1352 min_t(unsigned long,
1353 nr_pages, ARRAY_SIZE(pages)), pages);
1354 for (i = 0; i < ret; i++) {
1355 if (pages[i] == locked_page) {
1356 page_cache_release(pages[i]);
1360 clear_page_dirty_for_io(pages[i]);
1362 set_page_writeback(pages[i]);
1364 end_page_writeback(pages[i]);
1366 unlock_page(pages[i]);
1367 page_cache_release(pages[i]);
1375 EXPORT_SYMBOL(extent_clear_unlock_delalloc);
1378 * count the number of bytes in the tree that have a given bit(s)
1379 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1380 * cached. The total number found is returned.
1382 u64 count_range_bits(struct extent_io_tree *tree,
1383 u64 *start, u64 search_end, u64 max_bytes,
1386 struct rb_node *node;
1387 struct extent_state *state;
1388 u64 cur_start = *start;
1389 u64 total_bytes = 0;
1392 if (search_end <= cur_start) {
1397 spin_lock(&tree->lock);
1398 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1399 total_bytes = tree->dirty_bytes;
1403 * this search will find all the extents that end after
1406 node = tree_search(tree, cur_start);
1411 state = rb_entry(node, struct extent_state, rb_node);
1412 if (state->start > search_end)
1414 if (state->end >= cur_start && (state->state & bits)) {
1415 total_bytes += min(search_end, state->end) + 1 -
1416 max(cur_start, state->start);
1417 if (total_bytes >= max_bytes)
1420 *start = state->start;
1424 node = rb_next(node);
1429 spin_unlock(&tree->lock);
1435 * helper function to lock both pages and extents in the tree.
1436 * pages must be locked first.
1438 static int lock_range(struct extent_io_tree *tree, u64 start, u64 end)
1440 unsigned long index = start >> PAGE_CACHE_SHIFT;
1441 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1445 while (index <= end_index) {
1446 page = grab_cache_page(tree->mapping, index);
1452 err = PTR_ERR(page);
1457 lock_extent(tree, start, end, GFP_NOFS);
1462 * we failed above in getting the page at 'index', so we undo here
1463 * up to but not including the page at 'index'
1466 index = start >> PAGE_CACHE_SHIFT;
1467 while (index < end_index) {
1468 page = find_get_page(tree->mapping, index);
1470 page_cache_release(page);
1477 * helper function to unlock both pages and extents in the tree.
1479 static int unlock_range(struct extent_io_tree *tree, u64 start, u64 end)
1481 unsigned long index = start >> PAGE_CACHE_SHIFT;
1482 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1485 while (index <= end_index) {
1486 page = find_get_page(tree->mapping, index);
1488 page_cache_release(page);
1491 unlock_extent(tree, start, end, GFP_NOFS);
1497 * set the private field for a given byte offset in the tree. If there isn't
1498 * an extent_state there already, this does nothing.
1500 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1502 struct rb_node *node;
1503 struct extent_state *state;
1506 spin_lock(&tree->lock);
1508 * this search will find all the extents that end after
1511 node = tree_search(tree, start);
1516 state = rb_entry(node, struct extent_state, rb_node);
1517 if (state->start != start) {
1521 state->private = private;
1523 spin_unlock(&tree->lock);
1527 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1529 struct rb_node *node;
1530 struct extent_state *state;
1533 spin_lock(&tree->lock);
1535 * this search will find all the extents that end after
1538 node = tree_search(tree, start);
1543 state = rb_entry(node, struct extent_state, rb_node);
1544 if (state->start != start) {
1548 *private = state->private;
1550 spin_unlock(&tree->lock);
1555 * searches a range in the state tree for a given mask.
1556 * If 'filled' == 1, this returns 1 only if every extent in the tree
1557 * has the bits set. Otherwise, 1 is returned if any bit in the
1558 * range is found set.
1560 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1561 int bits, int filled)
1563 struct extent_state *state = NULL;
1564 struct rb_node *node;
1567 spin_lock(&tree->lock);
1568 node = tree_search(tree, start);
1569 while (node && start <= end) {
1570 state = rb_entry(node, struct extent_state, rb_node);
1572 if (filled && state->start > start) {
1577 if (state->start > end)
1580 if (state->state & bits) {
1584 } else if (filled) {
1588 start = state->end + 1;
1591 node = rb_next(node);
1598 spin_unlock(&tree->lock);
1601 EXPORT_SYMBOL(test_range_bit);
1604 * helper function to set a given page up to date if all the
1605 * extents in the tree for that page are up to date
1607 static int check_page_uptodate(struct extent_io_tree *tree,
1610 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1611 u64 end = start + PAGE_CACHE_SIZE - 1;
1612 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
1613 SetPageUptodate(page);
1618 * helper function to unlock a page if all the extents in the tree
1619 * for that page are unlocked
1621 static int check_page_locked(struct extent_io_tree *tree,
1624 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1625 u64 end = start + PAGE_CACHE_SIZE - 1;
1626 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
1632 * helper function to end page writeback if all the extents
1633 * in the tree for that page are done with writeback
1635 static int check_page_writeback(struct extent_io_tree *tree,
1638 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1639 u64 end = start + PAGE_CACHE_SIZE - 1;
1640 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0))
1641 end_page_writeback(page);
1645 /* lots and lots of room for performance fixes in the end_bio funcs */
1648 * after a writepage IO is done, we need to:
1649 * clear the uptodate bits on error
1650 * clear the writeback bits in the extent tree for this IO
1651 * end_page_writeback if the page has no more pending IO
1653 * Scheduling is not allowed, so the extent state tree is expected
1654 * to have one and only one object corresponding to this IO.
1656 static void end_bio_extent_writepage(struct bio *bio, int err)
1658 int uptodate = err == 0;
1659 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1660 struct extent_io_tree *tree;
1667 struct page *page = bvec->bv_page;
1668 tree = &BTRFS_I(page->mapping->host)->io_tree;
1670 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1672 end = start + bvec->bv_len - 1;
1674 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1679 if (--bvec >= bio->bi_io_vec)
1680 prefetchw(&bvec->bv_page->flags);
1681 if (tree->ops && tree->ops->writepage_end_io_hook) {
1682 ret = tree->ops->writepage_end_io_hook(page, start,
1683 end, NULL, uptodate);
1688 if (!uptodate && tree->ops &&
1689 tree->ops->writepage_io_failed_hook) {
1690 ret = tree->ops->writepage_io_failed_hook(bio, page,
1693 uptodate = (err == 0);
1699 clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
1700 ClearPageUptodate(page);
1704 clear_extent_writeback(tree, start, end, GFP_ATOMIC);
1707 end_page_writeback(page);
1709 check_page_writeback(tree, page);
1710 } while (bvec >= bio->bi_io_vec);
1716 * after a readpage IO is done, we need to:
1717 * clear the uptodate bits on error
1718 * set the uptodate bits if things worked
1719 * set the page up to date if all extents in the tree are uptodate
1720 * clear the lock bit in the extent tree
1721 * unlock the page if there are no other extents locked for it
1723 * Scheduling is not allowed, so the extent state tree is expected
1724 * to have one and only one object corresponding to this IO.
1726 static void end_bio_extent_readpage(struct bio *bio, int err)
1728 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1729 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1730 struct extent_io_tree *tree;
1740 struct page *page = bvec->bv_page;
1741 tree = &BTRFS_I(page->mapping->host)->io_tree;
1743 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1745 end = start + bvec->bv_len - 1;
1747 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1752 if (--bvec >= bio->bi_io_vec)
1753 prefetchw(&bvec->bv_page->flags);
1755 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
1756 ret = tree->ops->readpage_end_io_hook(page, start, end,
1761 if (!uptodate && tree->ops &&
1762 tree->ops->readpage_io_failed_hook) {
1763 ret = tree->ops->readpage_io_failed_hook(bio, page,
1767 test_bit(BIO_UPTODATE, &bio->bi_flags);
1775 set_extent_uptodate(tree, start, end,
1778 unlock_extent(tree, start, end, GFP_ATOMIC);
1782 SetPageUptodate(page);
1784 ClearPageUptodate(page);
1790 check_page_uptodate(tree, page);
1792 ClearPageUptodate(page);
1795 check_page_locked(tree, page);
1797 } while (bvec >= bio->bi_io_vec);
1803 * IO done from prepare_write is pretty simple, we just unlock
1804 * the structs in the extent tree when done, and set the uptodate bits
1807 static void end_bio_extent_preparewrite(struct bio *bio, int err)
1809 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1810 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1811 struct extent_io_tree *tree;
1816 struct page *page = bvec->bv_page;
1817 tree = &BTRFS_I(page->mapping->host)->io_tree;
1819 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1821 end = start + bvec->bv_len - 1;
1823 if (--bvec >= bio->bi_io_vec)
1824 prefetchw(&bvec->bv_page->flags);
1827 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1829 ClearPageUptodate(page);
1833 unlock_extent(tree, start, end, GFP_ATOMIC);
1835 } while (bvec >= bio->bi_io_vec);
1841 extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
1846 bio = bio_alloc(gfp_flags, nr_vecs);
1848 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
1849 while (!bio && (nr_vecs /= 2))
1850 bio = bio_alloc(gfp_flags, nr_vecs);
1855 bio->bi_bdev = bdev;
1856 bio->bi_sector = first_sector;
1861 static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
1862 unsigned long bio_flags)
1865 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1866 struct page *page = bvec->bv_page;
1867 struct extent_io_tree *tree = bio->bi_private;
1871 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1872 end = start + bvec->bv_len - 1;
1874 bio->bi_private = NULL;
1878 if (tree->ops && tree->ops->submit_bio_hook)
1879 tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
1880 mirror_num, bio_flags);
1882 submit_bio(rw, bio);
1883 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1889 static int submit_extent_page(int rw, struct extent_io_tree *tree,
1890 struct page *page, sector_t sector,
1891 size_t size, unsigned long offset,
1892 struct block_device *bdev,
1893 struct bio **bio_ret,
1894 unsigned long max_pages,
1895 bio_end_io_t end_io_func,
1897 unsigned long prev_bio_flags,
1898 unsigned long bio_flags)
1904 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
1905 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
1906 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
1908 if (bio_ret && *bio_ret) {
1911 contig = bio->bi_sector == sector;
1913 contig = bio->bi_sector + (bio->bi_size >> 9) ==
1916 if (prev_bio_flags != bio_flags || !contig ||
1917 (tree->ops && tree->ops->merge_bio_hook &&
1918 tree->ops->merge_bio_hook(page, offset, page_size, bio,
1920 bio_add_page(bio, page, page_size, offset) < page_size) {
1921 ret = submit_one_bio(rw, bio, mirror_num,
1928 if (this_compressed)
1931 nr = bio_get_nr_vecs(bdev);
1933 bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
1935 bio_add_page(bio, page, page_size, offset);
1936 bio->bi_end_io = end_io_func;
1937 bio->bi_private = tree;
1942 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
1947 void set_page_extent_mapped(struct page *page)
1949 if (!PagePrivate(page)) {
1950 SetPagePrivate(page);
1951 page_cache_get(page);
1952 set_page_private(page, EXTENT_PAGE_PRIVATE);
1955 EXPORT_SYMBOL(set_page_extent_mapped);
1957 static void set_page_extent_head(struct page *page, unsigned long len)
1959 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
1963 * basic readpage implementation. Locked extent state structs are inserted
1964 * into the tree that are removed when the IO is done (by the end_io
1967 static int __extent_read_full_page(struct extent_io_tree *tree,
1969 get_extent_t *get_extent,
1970 struct bio **bio, int mirror_num,
1971 unsigned long *bio_flags)
1973 struct inode *inode = page->mapping->host;
1974 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1975 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1979 u64 last_byte = i_size_read(inode);
1983 struct extent_map *em;
1984 struct block_device *bdev;
1987 size_t page_offset = 0;
1989 size_t disk_io_size;
1990 size_t blocksize = inode->i_sb->s_blocksize;
1991 unsigned long this_bio_flag = 0;
1993 set_page_extent_mapped(page);
1996 lock_extent(tree, start, end, GFP_NOFS);
1998 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2000 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2003 iosize = PAGE_CACHE_SIZE - zero_offset;
2004 userpage = kmap_atomic(page, KM_USER0);
2005 memset(userpage + zero_offset, 0, iosize);
2006 flush_dcache_page(page);
2007 kunmap_atomic(userpage, KM_USER0);
2010 while (cur <= end) {
2011 if (cur >= last_byte) {
2013 iosize = PAGE_CACHE_SIZE - page_offset;
2014 userpage = kmap_atomic(page, KM_USER0);
2015 memset(userpage + page_offset, 0, iosize);
2016 flush_dcache_page(page);
2017 kunmap_atomic(userpage, KM_USER0);
2018 set_extent_uptodate(tree, cur, cur + iosize - 1,
2020 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2023 em = get_extent(inode, page, page_offset, cur,
2025 if (IS_ERR(em) || !em) {
2027 unlock_extent(tree, cur, end, GFP_NOFS);
2030 extent_offset = cur - em->start;
2031 BUG_ON(extent_map_end(em) <= cur);
2034 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
2035 this_bio_flag = EXTENT_BIO_COMPRESSED;
2037 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2038 cur_end = min(extent_map_end(em) - 1, end);
2039 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2040 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2041 disk_io_size = em->block_len;
2042 sector = em->block_start >> 9;
2044 sector = (em->block_start + extent_offset) >> 9;
2045 disk_io_size = iosize;
2048 block_start = em->block_start;
2049 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2050 block_start = EXTENT_MAP_HOLE;
2051 free_extent_map(em);
2054 /* we've found a hole, just zero and go on */
2055 if (block_start == EXTENT_MAP_HOLE) {
2057 userpage = kmap_atomic(page, KM_USER0);
2058 memset(userpage + page_offset, 0, iosize);
2059 flush_dcache_page(page);
2060 kunmap_atomic(userpage, KM_USER0);
2062 set_extent_uptodate(tree, cur, cur + iosize - 1,
2064 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2066 page_offset += iosize;
2069 /* the get_extent function already copied into the page */
2070 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
2071 check_page_uptodate(tree, page);
2072 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2074 page_offset += iosize;
2077 /* we have an inline extent but it didn't get marked up
2078 * to date. Error out
2080 if (block_start == EXTENT_MAP_INLINE) {
2082 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2084 page_offset += iosize;
2089 if (tree->ops && tree->ops->readpage_io_hook) {
2090 ret = tree->ops->readpage_io_hook(page, cur,
2094 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2096 ret = submit_extent_page(READ, tree, page,
2097 sector, disk_io_size, page_offset,
2099 end_bio_extent_readpage, mirror_num,
2103 *bio_flags = this_bio_flag;
2108 page_offset += iosize;
2111 if (!PageError(page))
2112 SetPageUptodate(page);
2118 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2119 get_extent_t *get_extent)
2121 struct bio *bio = NULL;
2122 unsigned long bio_flags = 0;
2125 ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
2128 submit_one_bio(READ, bio, 0, bio_flags);
2131 EXPORT_SYMBOL(extent_read_full_page);
2134 * the writepage semantics are similar to regular writepage. extent
2135 * records are inserted to lock ranges in the tree, and as dirty areas
2136 * are found, they are marked writeback. Then the lock bits are removed
2137 * and the end_io handler clears the writeback ranges
2139 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2142 struct inode *inode = page->mapping->host;
2143 struct extent_page_data *epd = data;
2144 struct extent_io_tree *tree = epd->tree;
2145 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2147 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2151 u64 last_byte = i_size_read(inode);
2156 struct extent_map *em;
2157 struct block_device *bdev;
2160 size_t pg_offset = 0;
2162 loff_t i_size = i_size_read(inode);
2163 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2168 unsigned long nr_written = 0;
2170 WARN_ON(!PageLocked(page));
2171 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2172 if (page->index > end_index ||
2173 (page->index == end_index && !pg_offset)) {
2174 page->mapping->a_ops->invalidatepage(page, 0);
2179 if (page->index == end_index) {
2182 userpage = kmap_atomic(page, KM_USER0);
2183 memset(userpage + pg_offset, 0,
2184 PAGE_CACHE_SIZE - pg_offset);
2185 kunmap_atomic(userpage, KM_USER0);
2186 flush_dcache_page(page);
2190 set_page_extent_mapped(page);
2192 delalloc_start = start;
2195 if (!epd->extent_locked) {
2196 while (delalloc_end < page_end) {
2197 nr_delalloc = find_lock_delalloc_range(inode, tree,
2202 if (nr_delalloc == 0) {
2203 delalloc_start = delalloc_end + 1;
2206 tree->ops->fill_delalloc(inode, page, delalloc_start,
2207 delalloc_end, &page_started,
2209 delalloc_start = delalloc_end + 1;
2212 /* did the fill delalloc function already unlock and start
2217 goto update_nr_written;
2220 lock_extent(tree, start, page_end, GFP_NOFS);
2222 unlock_start = start;
2224 if (tree->ops && tree->ops->writepage_start_hook) {
2225 ret = tree->ops->writepage_start_hook(page, start,
2227 if (ret == -EAGAIN) {
2228 unlock_extent(tree, start, page_end, GFP_NOFS);
2229 redirty_page_for_writepage(wbc, page);
2232 goto update_nr_written;
2239 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0))
2240 printk(KERN_ERR "btrfs delalloc bits after lock_extent\n");
2242 if (last_byte <= start) {
2243 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
2244 unlock_extent(tree, start, page_end, GFP_NOFS);
2245 if (tree->ops && tree->ops->writepage_end_io_hook)
2246 tree->ops->writepage_end_io_hook(page, start,
2248 unlock_start = page_end + 1;
2252 set_extent_uptodate(tree, start, page_end, GFP_NOFS);
2253 blocksize = inode->i_sb->s_blocksize;
2255 while (cur <= end) {
2256 if (cur >= last_byte) {
2257 clear_extent_dirty(tree, cur, page_end, GFP_NOFS);
2258 unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
2259 if (tree->ops && tree->ops->writepage_end_io_hook)
2260 tree->ops->writepage_end_io_hook(page, cur,
2262 unlock_start = page_end + 1;
2265 em = epd->get_extent(inode, page, pg_offset, cur,
2267 if (IS_ERR(em) || !em) {
2272 extent_offset = cur - em->start;
2273 BUG_ON(extent_map_end(em) <= cur);
2275 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2276 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2277 sector = (em->block_start + extent_offset) >> 9;
2279 block_start = em->block_start;
2280 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2281 free_extent_map(em);
2285 * compressed and inline extents are written through other
2288 if (compressed || block_start == EXTENT_MAP_HOLE ||
2289 block_start == EXTENT_MAP_INLINE) {
2290 clear_extent_dirty(tree, cur,
2291 cur + iosize - 1, GFP_NOFS);
2293 unlock_extent(tree, unlock_start, cur + iosize - 1,
2297 * end_io notification does not happen here for
2298 * compressed extents
2300 if (!compressed && tree->ops &&
2301 tree->ops->writepage_end_io_hook)
2302 tree->ops->writepage_end_io_hook(page, cur,
2305 else if (compressed) {
2306 /* we don't want to end_page_writeback on
2307 * a compressed extent. this happens
2314 pg_offset += iosize;
2318 /* leave this out until we have a page_mkwrite call */
2319 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2322 pg_offset += iosize;
2326 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
2327 if (tree->ops && tree->ops->writepage_io_hook) {
2328 ret = tree->ops->writepage_io_hook(page, cur,
2336 unsigned long max_nr = end_index + 1;
2338 set_range_writeback(tree, cur, cur + iosize - 1);
2339 if (!PageWriteback(page)) {
2340 printk(KERN_ERR "btrfs warning page %lu not "
2341 "writeback, cur %llu end %llu\n",
2342 page->index, (unsigned long long)cur,
2343 (unsigned long long)end);
2346 ret = submit_extent_page(WRITE, tree, page, sector,
2347 iosize, pg_offset, bdev,
2349 end_bio_extent_writepage,
2355 pg_offset += iosize;
2360 /* make sure the mapping tag for page dirty gets cleared */
2361 set_page_writeback(page);
2362 end_page_writeback(page);
2364 if (unlock_start <= page_end)
2365 unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
2369 wbc->nr_to_write -= nr_written;
2370 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2371 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2372 page->mapping->writeback_index = page->index + nr_written;
2377 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2378 * @mapping: address space structure to write
2379 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2380 * @writepage: function called for each page
2381 * @data: data passed to writepage function
2383 * If a page is already under I/O, write_cache_pages() skips it, even
2384 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2385 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2386 * and msync() need to guarantee that all the data which was dirty at the time
2387 * the call was made get new I/O started against them. If wbc->sync_mode is
2388 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2389 * existing IO to complete.
2391 static int extent_write_cache_pages(struct extent_io_tree *tree,
2392 struct address_space *mapping,
2393 struct writeback_control *wbc,
2394 writepage_t writepage, void *data,
2395 void (*flush_fn)(void *))
2397 struct backing_dev_info *bdi = mapping->backing_dev_info;
2400 struct pagevec pvec;
2403 pgoff_t end; /* Inclusive */
2405 int range_whole = 0;
2407 if (wbc->nonblocking && bdi_write_congested(bdi)) {
2408 wbc->encountered_congestion = 1;
2412 pagevec_init(&pvec, 0);
2413 if (wbc->range_cyclic) {
2414 index = mapping->writeback_index; /* Start from prev offset */
2417 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2418 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2419 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2424 while (!done && (index <= end) &&
2425 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
2426 PAGECACHE_TAG_DIRTY, min(end - index,
2427 (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
2431 for (i = 0; i < nr_pages; i++) {
2432 struct page *page = pvec.pages[i];
2435 * At this point we hold neither mapping->tree_lock nor
2436 * lock on the page itself: the page may be truncated or
2437 * invalidated (changing page->mapping to NULL), or even
2438 * swizzled back from swapper_space to tmpfs file
2441 if (tree->ops && tree->ops->write_cache_pages_lock_hook)
2442 tree->ops->write_cache_pages_lock_hook(page);
2446 if (unlikely(page->mapping != mapping)) {
2451 if (!wbc->range_cyclic && page->index > end) {
2457 if (wbc->sync_mode != WB_SYNC_NONE) {
2458 if (PageWriteback(page))
2460 wait_on_page_writeback(page);
2463 if (PageWriteback(page) ||
2464 !clear_page_dirty_for_io(page)) {
2469 ret = (*writepage)(page, wbc, data);
2471 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
2475 if (ret || wbc->nr_to_write <= 0)
2477 if (wbc->nonblocking && bdi_write_congested(bdi)) {
2478 wbc->encountered_congestion = 1;
2482 pagevec_release(&pvec);
2485 if (!scanned && !done) {
2487 * We hit the last page and there is more work to be done: wrap
2488 * back to the start of the file
2497 static noinline void flush_write_bio(void *data)
2499 struct extent_page_data *epd = data;
2501 submit_one_bio(WRITE, epd->bio, 0, 0);
2506 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
2507 get_extent_t *get_extent,
2508 struct writeback_control *wbc)
2511 struct address_space *mapping = page->mapping;
2512 struct extent_page_data epd = {
2515 .get_extent = get_extent,
2518 struct writeback_control wbc_writepages = {
2520 .sync_mode = WB_SYNC_NONE,
2521 .older_than_this = NULL,
2523 .range_start = page_offset(page) + PAGE_CACHE_SIZE,
2524 .range_end = (loff_t)-1,
2528 ret = __extent_writepage(page, wbc, &epd);
2530 extent_write_cache_pages(tree, mapping, &wbc_writepages,
2531 __extent_writepage, &epd, flush_write_bio);
2533 submit_one_bio(WRITE, epd.bio, 0, 0);
2536 EXPORT_SYMBOL(extent_write_full_page);
2538 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
2539 u64 start, u64 end, get_extent_t *get_extent,
2543 struct address_space *mapping = inode->i_mapping;
2545 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
2548 struct extent_page_data epd = {
2551 .get_extent = get_extent,
2554 struct writeback_control wbc_writepages = {
2555 .bdi = inode->i_mapping->backing_dev_info,
2557 .older_than_this = NULL,
2558 .nr_to_write = nr_pages * 2,
2559 .range_start = start,
2560 .range_end = end + 1,
2563 while (start <= end) {
2564 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
2565 if (clear_page_dirty_for_io(page))
2566 ret = __extent_writepage(page, &wbc_writepages, &epd);
2568 if (tree->ops && tree->ops->writepage_end_io_hook)
2569 tree->ops->writepage_end_io_hook(page, start,
2570 start + PAGE_CACHE_SIZE - 1,
2574 page_cache_release(page);
2575 start += PAGE_CACHE_SIZE;
2579 submit_one_bio(WRITE, epd.bio, 0, 0);
2582 EXPORT_SYMBOL(extent_write_locked_range);
2585 int extent_writepages(struct extent_io_tree *tree,
2586 struct address_space *mapping,
2587 get_extent_t *get_extent,
2588 struct writeback_control *wbc)
2591 struct extent_page_data epd = {
2594 .get_extent = get_extent,
2598 ret = extent_write_cache_pages(tree, mapping, wbc,
2599 __extent_writepage, &epd,
2602 submit_one_bio(WRITE, epd.bio, 0, 0);
2605 EXPORT_SYMBOL(extent_writepages);
2607 int extent_readpages(struct extent_io_tree *tree,
2608 struct address_space *mapping,
2609 struct list_head *pages, unsigned nr_pages,
2610 get_extent_t get_extent)
2612 struct bio *bio = NULL;
2614 struct pagevec pvec;
2615 unsigned long bio_flags = 0;
2617 pagevec_init(&pvec, 0);
2618 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
2619 struct page *page = list_entry(pages->prev, struct page, lru);
2621 prefetchw(&page->flags);
2622 list_del(&page->lru);
2624 * what we want to do here is call add_to_page_cache_lru,
2625 * but that isn't exported, so we reproduce it here
2627 if (!add_to_page_cache(page, mapping,
2628 page->index, GFP_KERNEL)) {
2630 /* open coding of lru_cache_add, also not exported */
2631 page_cache_get(page);
2632 if (!pagevec_add(&pvec, page))
2633 __pagevec_lru_add_file(&pvec);
2634 __extent_read_full_page(tree, page, get_extent,
2635 &bio, 0, &bio_flags);
2637 page_cache_release(page);
2639 if (pagevec_count(&pvec))
2640 __pagevec_lru_add_file(&pvec);
2641 BUG_ON(!list_empty(pages));
2643 submit_one_bio(READ, bio, 0, bio_flags);
2646 EXPORT_SYMBOL(extent_readpages);
2649 * basic invalidatepage code, this waits on any locked or writeback
2650 * ranges corresponding to the page, and then deletes any extent state
2651 * records from the tree
2653 int extent_invalidatepage(struct extent_io_tree *tree,
2654 struct page *page, unsigned long offset)
2656 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
2657 u64 end = start + PAGE_CACHE_SIZE - 1;
2658 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
2660 start += (offset + blocksize - 1) & ~(blocksize - 1);
2664 lock_extent(tree, start, end, GFP_NOFS);
2665 wait_on_extent_writeback(tree, start, end);
2666 clear_extent_bit(tree, start, end,
2667 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
2671 EXPORT_SYMBOL(extent_invalidatepage);
2674 * simple commit_write call, set_range_dirty is used to mark both
2675 * the pages and the extent records as dirty
2677 int extent_commit_write(struct extent_io_tree *tree,
2678 struct inode *inode, struct page *page,
2679 unsigned from, unsigned to)
2681 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
2683 set_page_extent_mapped(page);
2684 set_page_dirty(page);
2686 if (pos > inode->i_size) {
2687 i_size_write(inode, pos);
2688 mark_inode_dirty(inode);
2692 EXPORT_SYMBOL(extent_commit_write);
2694 int extent_prepare_write(struct extent_io_tree *tree,
2695 struct inode *inode, struct page *page,
2696 unsigned from, unsigned to, get_extent_t *get_extent)
2698 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2699 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
2701 u64 orig_block_start;
2704 struct extent_map *em;
2705 unsigned blocksize = 1 << inode->i_blkbits;
2706 size_t page_offset = 0;
2707 size_t block_off_start;
2708 size_t block_off_end;
2714 set_page_extent_mapped(page);
2716 block_start = (page_start + from) & ~((u64)blocksize - 1);
2717 block_end = (page_start + to - 1) | (blocksize - 1);
2718 orig_block_start = block_start;
2720 lock_extent(tree, page_start, page_end, GFP_NOFS);
2721 while (block_start <= block_end) {
2722 em = get_extent(inode, page, page_offset, block_start,
2723 block_end - block_start + 1, 1);
2724 if (IS_ERR(em) || !em)
2727 cur_end = min(block_end, extent_map_end(em) - 1);
2728 block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
2729 block_off_end = block_off_start + blocksize;
2730 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
2732 if (!PageUptodate(page) && isnew &&
2733 (block_off_end > to || block_off_start < from)) {
2736 kaddr = kmap_atomic(page, KM_USER0);
2737 if (block_off_end > to)
2738 memset(kaddr + to, 0, block_off_end - to);
2739 if (block_off_start < from)
2740 memset(kaddr + block_off_start, 0,
2741 from - block_off_start);
2742 flush_dcache_page(page);
2743 kunmap_atomic(kaddr, KM_USER0);
2745 if ((em->block_start != EXTENT_MAP_HOLE &&
2746 em->block_start != EXTENT_MAP_INLINE) &&
2747 !isnew && !PageUptodate(page) &&
2748 (block_off_end > to || block_off_start < from) &&
2749 !test_range_bit(tree, block_start, cur_end,
2750 EXTENT_UPTODATE, 1)) {
2752 u64 extent_offset = block_start - em->start;
2754 sector = (em->block_start + extent_offset) >> 9;
2755 iosize = (cur_end - block_start + blocksize) &
2756 ~((u64)blocksize - 1);
2758 * we've already got the extent locked, but we
2759 * need to split the state such that our end_bio
2760 * handler can clear the lock.
2762 set_extent_bit(tree, block_start,
2763 block_start + iosize - 1,
2764 EXTENT_LOCKED, 0, NULL, GFP_NOFS);
2765 ret = submit_extent_page(READ, tree, page,
2766 sector, iosize, page_offset, em->bdev,
2768 end_bio_extent_preparewrite, 0,
2771 block_start = block_start + iosize;
2773 set_extent_uptodate(tree, block_start, cur_end,
2775 unlock_extent(tree, block_start, cur_end, GFP_NOFS);
2776 block_start = cur_end + 1;
2778 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
2779 free_extent_map(em);
2782 wait_extent_bit(tree, orig_block_start,
2783 block_end, EXTENT_LOCKED);
2785 check_page_uptodate(tree, page);
2787 /* FIXME, zero out newly allocated blocks on error */
2790 EXPORT_SYMBOL(extent_prepare_write);
2793 * a helper for releasepage, this tests for areas of the page that
2794 * are locked or under IO and drops the related state bits if it is safe
2797 int try_release_extent_state(struct extent_map_tree *map,
2798 struct extent_io_tree *tree, struct page *page,
2801 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2802 u64 end = start + PAGE_CACHE_SIZE - 1;
2805 if (test_range_bit(tree, start, end,
2806 EXTENT_IOBITS | EXTENT_ORDERED, 0))
2809 if ((mask & GFP_NOFS) == GFP_NOFS)
2811 clear_extent_bit(tree, start, end, EXTENT_UPTODATE,
2816 EXPORT_SYMBOL(try_release_extent_state);
2819 * a helper for releasepage. As long as there are no locked extents
2820 * in the range corresponding to the page, both state records and extent
2821 * map records are removed
2823 int try_release_extent_mapping(struct extent_map_tree *map,
2824 struct extent_io_tree *tree, struct page *page,
2827 struct extent_map *em;
2828 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2829 u64 end = start + PAGE_CACHE_SIZE - 1;
2831 if ((mask & __GFP_WAIT) &&
2832 page->mapping->host->i_size > 16 * 1024 * 1024) {
2834 while (start <= end) {
2835 len = end - start + 1;
2836 spin_lock(&map->lock);
2837 em = lookup_extent_mapping(map, start, len);
2838 if (!em || IS_ERR(em)) {
2839 spin_unlock(&map->lock);
2842 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
2843 em->start != start) {
2844 spin_unlock(&map->lock);
2845 free_extent_map(em);
2848 if (!test_range_bit(tree, em->start,
2849 extent_map_end(em) - 1,
2850 EXTENT_LOCKED | EXTENT_WRITEBACK |
2853 remove_extent_mapping(map, em);
2854 /* once for the rb tree */
2855 free_extent_map(em);
2857 start = extent_map_end(em);
2858 spin_unlock(&map->lock);
2861 free_extent_map(em);
2864 return try_release_extent_state(map, tree, page, mask);
2866 EXPORT_SYMBOL(try_release_extent_mapping);
2868 sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
2869 get_extent_t *get_extent)
2871 struct inode *inode = mapping->host;
2872 u64 start = iblock << inode->i_blkbits;
2873 sector_t sector = 0;
2874 size_t blksize = (1 << inode->i_blkbits);
2875 struct extent_map *em;
2877 lock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
2879 em = get_extent(inode, NULL, 0, start, blksize, 0);
2880 unlock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
2882 if (!em || IS_ERR(em))
2885 if (em->block_start > EXTENT_MAP_LAST_BYTE)
2888 sector = (em->block_start + start - em->start) >> inode->i_blkbits;
2890 free_extent_map(em);
2894 static inline struct page *extent_buffer_page(struct extent_buffer *eb,
2898 struct address_space *mapping;
2901 return eb->first_page;
2902 i += eb->start >> PAGE_CACHE_SHIFT;
2903 mapping = eb->first_page->mapping;
2908 * extent_buffer_page is only called after pinning the page
2909 * by increasing the reference count. So we know the page must
2910 * be in the radix tree.
2913 p = radix_tree_lookup(&mapping->page_tree, i);
2919 static inline unsigned long num_extent_pages(u64 start, u64 len)
2921 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
2922 (start >> PAGE_CACHE_SHIFT);
2925 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
2930 struct extent_buffer *eb = NULL;
2932 unsigned long flags;
2935 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
2938 mutex_init(&eb->mutex);
2940 spin_lock_irqsave(&leak_lock, flags);
2941 list_add(&eb->leak_list, &buffers);
2942 spin_unlock_irqrestore(&leak_lock, flags);
2944 atomic_set(&eb->refs, 1);
2949 static void __free_extent_buffer(struct extent_buffer *eb)
2952 unsigned long flags;
2953 spin_lock_irqsave(&leak_lock, flags);
2954 list_del(&eb->leak_list);
2955 spin_unlock_irqrestore(&leak_lock, flags);
2957 kmem_cache_free(extent_buffer_cache, eb);
2960 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
2961 u64 start, unsigned long len,
2965 unsigned long num_pages = num_extent_pages(start, len);
2967 unsigned long index = start >> PAGE_CACHE_SHIFT;
2968 struct extent_buffer *eb;
2969 struct extent_buffer *exists = NULL;
2971 struct address_space *mapping = tree->mapping;
2974 spin_lock(&tree->buffer_lock);
2975 eb = buffer_search(tree, start);
2977 atomic_inc(&eb->refs);
2978 spin_unlock(&tree->buffer_lock);
2979 mark_page_accessed(eb->first_page);
2982 spin_unlock(&tree->buffer_lock);
2984 eb = __alloc_extent_buffer(tree, start, len, mask);
2989 eb->first_page = page0;
2992 page_cache_get(page0);
2993 mark_page_accessed(page0);
2994 set_page_extent_mapped(page0);
2995 set_page_extent_head(page0, len);
2996 uptodate = PageUptodate(page0);
3000 for (; i < num_pages; i++, index++) {
3001 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
3006 set_page_extent_mapped(p);
3007 mark_page_accessed(p);
3010 set_page_extent_head(p, len);
3012 set_page_private(p, EXTENT_PAGE_PRIVATE);
3014 if (!PageUptodate(p))
3019 eb->flags |= EXTENT_UPTODATE;
3020 eb->flags |= EXTENT_BUFFER_FILLED;
3022 spin_lock(&tree->buffer_lock);
3023 exists = buffer_tree_insert(tree, start, &eb->rb_node);
3025 /* add one reference for the caller */
3026 atomic_inc(&exists->refs);
3027 spin_unlock(&tree->buffer_lock);
3030 spin_unlock(&tree->buffer_lock);
3032 /* add one reference for the tree */
3033 atomic_inc(&eb->refs);
3037 if (!atomic_dec_and_test(&eb->refs))
3039 for (index = 1; index < i; index++)
3040 page_cache_release(extent_buffer_page(eb, index));
3041 page_cache_release(extent_buffer_page(eb, 0));
3042 __free_extent_buffer(eb);
3045 EXPORT_SYMBOL(alloc_extent_buffer);
3047 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
3048 u64 start, unsigned long len,
3051 struct extent_buffer *eb;
3053 spin_lock(&tree->buffer_lock);
3054 eb = buffer_search(tree, start);
3056 atomic_inc(&eb->refs);
3057 spin_unlock(&tree->buffer_lock);
3060 mark_page_accessed(eb->first_page);
3064 EXPORT_SYMBOL(find_extent_buffer);
3066 void free_extent_buffer(struct extent_buffer *eb)
3071 if (!atomic_dec_and_test(&eb->refs))
3076 EXPORT_SYMBOL(free_extent_buffer);
3078 int clear_extent_buffer_dirty(struct extent_io_tree *tree,
3079 struct extent_buffer *eb)
3083 unsigned long num_pages;
3086 u64 start = eb->start;
3087 u64 end = start + eb->len - 1;
3089 set = clear_extent_dirty(tree, start, end, GFP_NOFS);
3090 num_pages = num_extent_pages(eb->start, eb->len);
3092 for (i = 0; i < num_pages; i++) {
3093 page = extent_buffer_page(eb, i);
3094 if (!set && !PageDirty(page))
3099 set_page_extent_head(page, eb->len);
3101 set_page_private(page, EXTENT_PAGE_PRIVATE);
3104 * if we're on the last page or the first page and the
3105 * block isn't aligned on a page boundary, do extra checks
3106 * to make sure we don't clean page that is partially dirty
3108 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
3109 ((i == num_pages - 1) &&
3110 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
3111 start = (u64)page->index << PAGE_CACHE_SHIFT;
3112 end = start + PAGE_CACHE_SIZE - 1;
3113 if (test_range_bit(tree, start, end,
3119 clear_page_dirty_for_io(page);
3120 spin_lock_irq(&page->mapping->tree_lock);
3121 if (!PageDirty(page)) {
3122 radix_tree_tag_clear(&page->mapping->page_tree,
3124 PAGECACHE_TAG_DIRTY);
3126 spin_unlock_irq(&page->mapping->tree_lock);
3131 EXPORT_SYMBOL(clear_extent_buffer_dirty);
3133 int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
3134 struct extent_buffer *eb)
3136 return wait_on_extent_writeback(tree, eb->start,
3137 eb->start + eb->len - 1);
3139 EXPORT_SYMBOL(wait_on_extent_buffer_writeback);
3141 int set_extent_buffer_dirty(struct extent_io_tree *tree,
3142 struct extent_buffer *eb)
3145 unsigned long num_pages;
3147 num_pages = num_extent_pages(eb->start, eb->len);
3148 for (i = 0; i < num_pages; i++) {
3149 struct page *page = extent_buffer_page(eb, i);
3150 /* writepage may need to do something special for the
3151 * first page, we have to make sure page->private is
3152 * properly set. releasepage may drop page->private
3153 * on us if the page isn't already dirty.
3157 set_page_extent_head(page, eb->len);
3158 } else if (PagePrivate(page) &&
3159 page->private != EXTENT_PAGE_PRIVATE) {
3160 set_page_extent_mapped(page);
3162 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
3163 set_extent_dirty(tree, page_offset(page),
3164 page_offset(page) + PAGE_CACHE_SIZE - 1,
3170 EXPORT_SYMBOL(set_extent_buffer_dirty);
3172 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
3173 struct extent_buffer *eb)
3177 unsigned long num_pages;
3179 num_pages = num_extent_pages(eb->start, eb->len);
3180 eb->flags &= ~EXTENT_UPTODATE;
3182 clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3184 for (i = 0; i < num_pages; i++) {
3185 page = extent_buffer_page(eb, i);
3187 ClearPageUptodate(page);
3192 int set_extent_buffer_uptodate(struct extent_io_tree *tree,
3193 struct extent_buffer *eb)
3197 unsigned long num_pages;
3199 num_pages = num_extent_pages(eb->start, eb->len);
3201 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3203 for (i = 0; i < num_pages; i++) {
3204 page = extent_buffer_page(eb, i);
3205 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
3206 ((i == num_pages - 1) &&
3207 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
3208 check_page_uptodate(tree, page);
3211 SetPageUptodate(page);
3215 EXPORT_SYMBOL(set_extent_buffer_uptodate);
3217 int extent_range_uptodate(struct extent_io_tree *tree,
3222 int pg_uptodate = 1;
3224 unsigned long index;
3226 ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1);
3229 while (start <= end) {
3230 index = start >> PAGE_CACHE_SHIFT;
3231 page = find_get_page(tree->mapping, index);
3232 uptodate = PageUptodate(page);
3233 page_cache_release(page);
3238 start += PAGE_CACHE_SIZE;
3243 int extent_buffer_uptodate(struct extent_io_tree *tree,
3244 struct extent_buffer *eb)
3247 unsigned long num_pages;
3250 int pg_uptodate = 1;
3252 if (eb->flags & EXTENT_UPTODATE)
3255 ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3256 EXTENT_UPTODATE, 1);
3260 num_pages = num_extent_pages(eb->start, eb->len);
3261 for (i = 0; i < num_pages; i++) {
3262 page = extent_buffer_page(eb, i);
3263 if (!PageUptodate(page)) {
3270 EXPORT_SYMBOL(extent_buffer_uptodate);
3272 int read_extent_buffer_pages(struct extent_io_tree *tree,
3273 struct extent_buffer *eb,
3274 u64 start, int wait,
3275 get_extent_t *get_extent, int mirror_num)
3278 unsigned long start_i;
3282 int locked_pages = 0;
3283 int all_uptodate = 1;
3284 int inc_all_pages = 0;
3285 unsigned long num_pages;
3286 struct bio *bio = NULL;
3287 unsigned long bio_flags = 0;
3289 if (eb->flags & EXTENT_UPTODATE)
3292 if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3293 EXTENT_UPTODATE, 1)) {
3298 WARN_ON(start < eb->start);
3299 start_i = (start >> PAGE_CACHE_SHIFT) -
3300 (eb->start >> PAGE_CACHE_SHIFT);
3305 num_pages = num_extent_pages(eb->start, eb->len);
3306 for (i = start_i; i < num_pages; i++) {
3307 page = extent_buffer_page(eb, i);
3309 if (!trylock_page(page))
3315 if (!PageUptodate(page))
3320 eb->flags |= EXTENT_UPTODATE;
3324 for (i = start_i; i < num_pages; i++) {
3325 page = extent_buffer_page(eb, i);
3327 page_cache_get(page);
3328 if (!PageUptodate(page)) {
3331 ClearPageError(page);
3332 err = __extent_read_full_page(tree, page,
3334 mirror_num, &bio_flags);
3343 submit_one_bio(READ, bio, mirror_num, bio_flags);
3348 for (i = start_i; i < num_pages; i++) {
3349 page = extent_buffer_page(eb, i);
3350 wait_on_page_locked(page);
3351 if (!PageUptodate(page))
3356 eb->flags |= EXTENT_UPTODATE;
3361 while (locked_pages > 0) {
3362 page = extent_buffer_page(eb, i);
3369 EXPORT_SYMBOL(read_extent_buffer_pages);
3371 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
3372 unsigned long start,
3379 char *dst = (char *)dstv;
3380 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3381 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3383 WARN_ON(start > eb->len);
3384 WARN_ON(start + len > eb->start + eb->len);
3386 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3389 page = extent_buffer_page(eb, i);
3391 cur = min(len, (PAGE_CACHE_SIZE - offset));
3392 kaddr = kmap_atomic(page, KM_USER1);
3393 memcpy(dst, kaddr + offset, cur);
3394 kunmap_atomic(kaddr, KM_USER1);
3402 EXPORT_SYMBOL(read_extent_buffer);
3404 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
3405 unsigned long min_len, char **token, char **map,
3406 unsigned long *map_start,
3407 unsigned long *map_len, int km)
3409 size_t offset = start & (PAGE_CACHE_SIZE - 1);
3412 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3413 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3414 unsigned long end_i = (start_offset + start + min_len - 1) >>
3421 offset = start_offset;
3425 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
3428 if (start + min_len > eb->len) {
3429 printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
3430 "wanted %lu %lu\n", (unsigned long long)eb->start,
3431 eb->len, start, min_len);
3435 p = extent_buffer_page(eb, i);
3436 kaddr = kmap_atomic(p, km);
3438 *map = kaddr + offset;
3439 *map_len = PAGE_CACHE_SIZE - offset;
3442 EXPORT_SYMBOL(map_private_extent_buffer);
3444 int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
3445 unsigned long min_len,
3446 char **token, char **map,
3447 unsigned long *map_start,
3448 unsigned long *map_len, int km)
3452 if (eb->map_token) {
3453 unmap_extent_buffer(eb, eb->map_token, km);
3454 eb->map_token = NULL;
3456 WARN_ON(!mutex_is_locked(&eb->mutex));
3458 err = map_private_extent_buffer(eb, start, min_len, token, map,
3459 map_start, map_len, km);
3461 eb->map_token = *token;
3463 eb->map_start = *map_start;
3464 eb->map_len = *map_len;
3468 EXPORT_SYMBOL(map_extent_buffer);
3470 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
3472 kunmap_atomic(token, km);
3474 EXPORT_SYMBOL(unmap_extent_buffer);
3476 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
3477 unsigned long start,
3484 char *ptr = (char *)ptrv;
3485 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3486 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3489 WARN_ON(start > eb->len);
3490 WARN_ON(start + len > eb->start + eb->len);
3492 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3495 page = extent_buffer_page(eb, i);
3497 cur = min(len, (PAGE_CACHE_SIZE - offset));
3499 kaddr = kmap_atomic(page, KM_USER0);
3500 ret = memcmp(ptr, kaddr + offset, cur);
3501 kunmap_atomic(kaddr, KM_USER0);
3512 EXPORT_SYMBOL(memcmp_extent_buffer);
3514 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
3515 unsigned long start, unsigned long len)
3521 char *src = (char *)srcv;
3522 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3523 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3525 WARN_ON(start > eb->len);
3526 WARN_ON(start + len > eb->start + eb->len);
3528 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3531 page = extent_buffer_page(eb, i);
3532 WARN_ON(!PageUptodate(page));
3534 cur = min(len, PAGE_CACHE_SIZE - offset);
3535 kaddr = kmap_atomic(page, KM_USER1);
3536 memcpy(kaddr + offset, src, cur);
3537 kunmap_atomic(kaddr, KM_USER1);
3545 EXPORT_SYMBOL(write_extent_buffer);
3547 void memset_extent_buffer(struct extent_buffer *eb, char c,
3548 unsigned long start, unsigned long len)
3554 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3555 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3557 WARN_ON(start > eb->len);
3558 WARN_ON(start + len > eb->start + eb->len);
3560 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3563 page = extent_buffer_page(eb, i);
3564 WARN_ON(!PageUptodate(page));
3566 cur = min(len, PAGE_CACHE_SIZE - offset);
3567 kaddr = kmap_atomic(page, KM_USER0);
3568 memset(kaddr + offset, c, cur);
3569 kunmap_atomic(kaddr, KM_USER0);
3576 EXPORT_SYMBOL(memset_extent_buffer);
3578 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
3579 unsigned long dst_offset, unsigned long src_offset,
3582 u64 dst_len = dst->len;
3587 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3588 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3590 WARN_ON(src->len != dst_len);
3592 offset = (start_offset + dst_offset) &
3593 ((unsigned long)PAGE_CACHE_SIZE - 1);
3596 page = extent_buffer_page(dst, i);
3597 WARN_ON(!PageUptodate(page));
3599 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
3601 kaddr = kmap_atomic(page, KM_USER0);
3602 read_extent_buffer(src, kaddr + offset, src_offset, cur);
3603 kunmap_atomic(kaddr, KM_USER0);
3611 EXPORT_SYMBOL(copy_extent_buffer);
3613 static void move_pages(struct page *dst_page, struct page *src_page,
3614 unsigned long dst_off, unsigned long src_off,
3617 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3618 if (dst_page == src_page) {
3619 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
3621 char *src_kaddr = kmap_atomic(src_page, KM_USER1);
3622 char *p = dst_kaddr + dst_off + len;
3623 char *s = src_kaddr + src_off + len;
3628 kunmap_atomic(src_kaddr, KM_USER1);
3630 kunmap_atomic(dst_kaddr, KM_USER0);
3633 static void copy_pages(struct page *dst_page, struct page *src_page,
3634 unsigned long dst_off, unsigned long src_off,
3637 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3640 if (dst_page != src_page)
3641 src_kaddr = kmap_atomic(src_page, KM_USER1);
3643 src_kaddr = dst_kaddr;
3645 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
3646 kunmap_atomic(dst_kaddr, KM_USER0);
3647 if (dst_page != src_page)
3648 kunmap_atomic(src_kaddr, KM_USER1);
3651 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3652 unsigned long src_offset, unsigned long len)
3655 size_t dst_off_in_page;
3656 size_t src_off_in_page;
3657 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3658 unsigned long dst_i;
3659 unsigned long src_i;
3661 if (src_offset + len > dst->len) {
3662 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
3663 "len %lu dst len %lu\n", src_offset, len, dst->len);
3666 if (dst_offset + len > dst->len) {
3667 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
3668 "len %lu dst len %lu\n", dst_offset, len, dst->len);
3673 dst_off_in_page = (start_offset + dst_offset) &
3674 ((unsigned long)PAGE_CACHE_SIZE - 1);
3675 src_off_in_page = (start_offset + src_offset) &
3676 ((unsigned long)PAGE_CACHE_SIZE - 1);
3678 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3679 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
3681 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
3683 cur = min_t(unsigned long, cur,
3684 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
3686 copy_pages(extent_buffer_page(dst, dst_i),
3687 extent_buffer_page(dst, src_i),
3688 dst_off_in_page, src_off_in_page, cur);
3695 EXPORT_SYMBOL(memcpy_extent_buffer);
3697 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3698 unsigned long src_offset, unsigned long len)
3701 size_t dst_off_in_page;
3702 size_t src_off_in_page;
3703 unsigned long dst_end = dst_offset + len - 1;
3704 unsigned long src_end = src_offset + len - 1;
3705 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3706 unsigned long dst_i;
3707 unsigned long src_i;
3709 if (src_offset + len > dst->len) {
3710 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
3711 "len %lu len %lu\n", src_offset, len, dst->len);
3714 if (dst_offset + len > dst->len) {
3715 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
3716 "len %lu len %lu\n", dst_offset, len, dst->len);
3719 if (dst_offset < src_offset) {
3720 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
3724 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
3725 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
3727 dst_off_in_page = (start_offset + dst_end) &
3728 ((unsigned long)PAGE_CACHE_SIZE - 1);
3729 src_off_in_page = (start_offset + src_end) &
3730 ((unsigned long)PAGE_CACHE_SIZE - 1);
3732 cur = min_t(unsigned long, len, src_off_in_page + 1);
3733 cur = min(cur, dst_off_in_page + 1);
3734 move_pages(extent_buffer_page(dst, dst_i),
3735 extent_buffer_page(dst, src_i),
3736 dst_off_in_page - cur + 1,
3737 src_off_in_page - cur + 1, cur);
3744 EXPORT_SYMBOL(memmove_extent_buffer);
3746 int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
3748 u64 start = page_offset(page);
3749 struct extent_buffer *eb;
3752 unsigned long num_pages;
3754 spin_lock(&tree->buffer_lock);
3755 eb = buffer_search(tree, start);
3759 if (atomic_read(&eb->refs) > 1) {
3763 /* at this point we can safely release the extent buffer */
3764 num_pages = num_extent_pages(eb->start, eb->len);
3765 for (i = 0; i < num_pages; i++)
3766 page_cache_release(extent_buffer_page(eb, i));
3767 rb_erase(&eb->rb_node, &tree->buffer);
3768 __free_extent_buffer(eb);
3770 spin_unlock(&tree->buffer_lock);
3773 EXPORT_SYMBOL(try_release_extent_buffer);