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 "extent_map.h"
13 /* temporary define until extent_map moves out of btrfs */
14 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
15 unsigned long extra_flags,
16 void (*ctor)(void *, struct kmem_cache *,
19 static struct kmem_cache *extent_map_cache;
20 static struct kmem_cache *extent_state_cache;
26 struct rb_node rb_node;
29 /* bits for the extent state */
30 #define EXTENT_DIRTY 1
31 #define EXTENT_WRITEBACK (1 << 1)
32 #define EXTENT_UPTODATE (1 << 2)
33 #define EXTENT_LOCKED (1 << 3)
34 #define EXTENT_NEW (1 << 4)
35 #define EXTENT_DELALLOC (1 << 5)
37 #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
39 void __init extent_map_init(void)
41 extent_map_cache = btrfs_cache_create("extent_map",
42 sizeof(struct extent_map),
45 extent_state_cache = btrfs_cache_create("extent_state",
46 sizeof(struct extent_state),
51 void __exit extent_map_exit(void)
54 kmem_cache_destroy(extent_map_cache);
55 if (extent_state_cache)
56 kmem_cache_destroy(extent_state_cache);
59 void extent_map_tree_init(struct extent_map_tree *tree,
60 struct address_space *mapping, gfp_t mask)
62 tree->map.rb_node = NULL;
63 tree->state.rb_node = NULL;
65 rwlock_init(&tree->lock);
66 tree->mapping = mapping;
68 EXPORT_SYMBOL(extent_map_tree_init);
70 struct extent_map *alloc_extent_map(gfp_t mask)
72 struct extent_map *em;
73 em = kmem_cache_alloc(extent_map_cache, mask);
74 if (!em || IS_ERR(em))
77 atomic_set(&em->refs, 1);
80 EXPORT_SYMBOL(alloc_extent_map);
82 void free_extent_map(struct extent_map *em)
86 if (atomic_dec_and_test(&em->refs)) {
88 kmem_cache_free(extent_map_cache, em);
91 EXPORT_SYMBOL(free_extent_map);
94 struct extent_state *alloc_extent_state(gfp_t mask)
96 struct extent_state *state;
97 state = kmem_cache_alloc(extent_state_cache, mask);
98 if (!state || IS_ERR(state))
103 atomic_set(&state->refs, 1);
104 init_waitqueue_head(&state->wq);
107 EXPORT_SYMBOL(alloc_extent_state);
109 void free_extent_state(struct extent_state *state)
113 if (atomic_dec_and_test(&state->refs)) {
114 WARN_ON(state->in_tree);
115 kmem_cache_free(extent_state_cache, state);
118 EXPORT_SYMBOL(free_extent_state);
120 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
121 struct rb_node *node)
123 struct rb_node ** p = &root->rb_node;
124 struct rb_node * parent = NULL;
125 struct tree_entry *entry;
129 entry = rb_entry(parent, struct tree_entry, rb_node);
131 if (offset < entry->start)
133 else if (offset > entry->end)
139 entry = rb_entry(node, struct tree_entry, rb_node);
141 rb_link_node(node, parent, p);
142 rb_insert_color(node, root);
146 static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
147 struct rb_node **prev_ret)
149 struct rb_node * n = root->rb_node;
150 struct rb_node *prev = NULL;
151 struct tree_entry *entry;
152 struct tree_entry *prev_entry = NULL;
155 entry = rb_entry(n, struct tree_entry, rb_node);
159 if (offset < entry->start)
161 else if (offset > entry->end)
168 while(prev && offset > prev_entry->end) {
169 prev = rb_next(prev);
170 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
176 static inline struct rb_node *tree_search(struct rb_root *root, u64 offset)
178 struct rb_node *prev;
180 ret = __tree_search(root, offset, &prev);
186 static int tree_delete(struct rb_root *root, u64 offset)
188 struct rb_node *node;
189 struct tree_entry *entry;
191 node = __tree_search(root, offset, NULL);
194 entry = rb_entry(node, struct tree_entry, rb_node);
196 rb_erase(node, root);
201 * add_extent_mapping tries a simple backward merge with existing
202 * mappings. The extent_map struct passed in will be inserted into
203 * the tree directly (no copies made, just a reference taken).
205 int add_extent_mapping(struct extent_map_tree *tree,
206 struct extent_map *em)
209 struct extent_map *prev = NULL;
212 write_lock_irq(&tree->lock);
213 rb = tree_insert(&tree->map, em->end, &em->rb_node);
215 prev = rb_entry(rb, struct extent_map, rb_node);
216 printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev->start, prev->end, em->start, em->end);
220 atomic_inc(&em->refs);
221 if (em->start != 0) {
222 rb = rb_prev(&em->rb_node);
224 prev = rb_entry(rb, struct extent_map, rb_node);
225 if (prev && prev->end + 1 == em->start &&
226 ((em->block_start == 0 && prev->block_start == 0) ||
227 (em->block_start == prev->block_end + 1))) {
228 em->start = prev->start;
229 em->block_start = prev->block_start;
230 rb_erase(&prev->rb_node, &tree->map);
232 free_extent_map(prev);
236 write_unlock_irq(&tree->lock);
239 EXPORT_SYMBOL(add_extent_mapping);
242 * lookup_extent_mapping returns the first extent_map struct in the
243 * tree that intersects the [start, end] (inclusive) range. There may
244 * be additional objects in the tree that intersect, so check the object
245 * returned carefully to make sure you don't need additional lookups.
247 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
250 struct extent_map *em;
251 struct rb_node *rb_node;
253 read_lock_irq(&tree->lock);
254 rb_node = tree_search(&tree->map, start);
259 if (IS_ERR(rb_node)) {
260 em = ERR_PTR(PTR_ERR(rb_node));
263 em = rb_entry(rb_node, struct extent_map, rb_node);
264 if (em->end < start || em->start > end) {
268 atomic_inc(&em->refs);
270 read_unlock_irq(&tree->lock);
273 EXPORT_SYMBOL(lookup_extent_mapping);
276 * removes an extent_map struct from the tree. No reference counts are
277 * dropped, and no checks are done to see if the range is in use
279 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
283 write_lock_irq(&tree->lock);
284 ret = tree_delete(&tree->map, em->end);
285 write_unlock_irq(&tree->lock);
288 EXPORT_SYMBOL(remove_extent_mapping);
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_map_tree *tree,
300 struct extent_state *state)
302 struct extent_state *other;
303 struct rb_node *other_node;
305 if (state->state & EXTENT_IOBITS)
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);
334 * insert an extent_state struct into the tree. 'bits' are set on the
335 * struct before it is inserted.
337 * This may return -EEXIST if the extent is already there, in which case the
338 * state struct is freed.
340 * The tree lock is not taken internally. This is a utility function and
341 * probably isn't what you want to call (see set/clear_extent_bit).
343 static int insert_state(struct extent_map_tree *tree,
344 struct extent_state *state, u64 start, u64 end,
347 struct rb_node *node;
350 printk("end < start %Lu %Lu\n", end, start);
353 state->state |= bits;
354 state->start = start;
356 if ((end & 4095) == 0) {
357 printk("insert state %Lu %Lu strange end\n", start, end);
360 node = tree_insert(&tree->state, end, &state->rb_node);
362 struct extent_state *found;
363 found = rb_entry(node, struct extent_state, rb_node);
364 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end);
365 free_extent_state(state);
368 merge_state(tree, state);
373 * split a given extent state struct in two, inserting the preallocated
374 * struct 'prealloc' as the newly created second half. 'split' indicates an
375 * offset inside 'orig' where it should be split.
378 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
379 * are two extent state structs in the tree:
380 * prealloc: [orig->start, split - 1]
381 * orig: [ split, orig->end ]
383 * The tree locks are not taken by this function. They need to be held
386 static int split_state(struct extent_map_tree *tree, struct extent_state *orig,
387 struct extent_state *prealloc, u64 split)
389 struct rb_node *node;
390 prealloc->start = orig->start;
391 prealloc->end = split - 1;
392 prealloc->state = orig->state;
394 if ((prealloc->end & 4095) == 0) {
395 printk("insert state %Lu %Lu strange end\n", prealloc->start,
399 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
401 struct extent_state *found;
402 found = rb_entry(node, struct extent_state, rb_node);
403 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end);
404 free_extent_state(prealloc);
411 * utility function to clear some bits in an extent state struct.
412 * it will optionally wake up any one waiting on this state (wake == 1), or
413 * forcibly remove the state from the tree (delete == 1).
415 * If no bits are set on the state struct after clearing things, the
416 * struct is freed and removed from the tree
418 static int clear_state_bit(struct extent_map_tree *tree,
419 struct extent_state *state, int bits, int wake,
422 int ret = state->state & bits;
423 state->state &= ~bits;
426 if (delete || state->state == 0) {
427 if (state->in_tree) {
428 rb_erase(&state->rb_node, &tree->state);
430 free_extent_state(state);
435 merge_state(tree, state);
441 * clear some bits on a range in the tree. This may require splitting
442 * or inserting elements in the tree, so the gfp mask is used to
443 * indicate which allocations or sleeping are allowed.
445 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
446 * the given range from the tree regardless of state (ie for truncate).
448 * the range [start, end] is inclusive.
450 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
451 * bits were already set, or zero if none of the bits were already set.
453 int clear_extent_bit(struct extent_map_tree *tree, u64 start, u64 end,
454 int bits, int wake, int delete, gfp_t mask)
456 struct extent_state *state;
457 struct extent_state *prealloc = NULL;
458 struct rb_node *node;
464 if (!prealloc && (mask & __GFP_WAIT)) {
465 prealloc = alloc_extent_state(mask);
470 write_lock_irqsave(&tree->lock, flags);
472 * this search will find the extents that end after
475 node = tree_search(&tree->state, start);
478 state = rb_entry(node, struct extent_state, rb_node);
479 if (state->start > end)
481 WARN_ON(state->end < start);
484 * | ---- desired range ---- |
486 * | ------------- state -------------- |
488 * We need to split the extent we found, and may flip
489 * bits on second half.
491 * If the extent we found extends past our range, we
492 * just split and search again. It'll get split again
493 * the next time though.
495 * If the extent we found is inside our range, we clear
496 * the desired bit on it.
499 if (state->start < start) {
500 err = split_state(tree, state, prealloc, start);
501 BUG_ON(err == -EEXIST);
505 if (state->end <= end) {
506 start = state->end + 1;
507 set |= clear_state_bit(tree, state, bits,
510 start = state->start;
515 * | ---- desired range ---- |
517 * We need to split the extent, and clear the bit
520 if (state->start <= end && state->end > end) {
521 err = split_state(tree, state, prealloc, end + 1);
522 BUG_ON(err == -EEXIST);
526 set |= clear_state_bit(tree, prealloc, bits,
532 start = state->end + 1;
533 set |= clear_state_bit(tree, state, bits, wake, delete);
537 write_unlock_irqrestore(&tree->lock, flags);
539 free_extent_state(prealloc);
546 write_unlock_irqrestore(&tree->lock, flags);
547 if (mask & __GFP_WAIT)
551 EXPORT_SYMBOL(clear_extent_bit);
553 static int wait_on_state(struct extent_map_tree *tree,
554 struct extent_state *state)
557 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
558 read_unlock_irq(&tree->lock);
560 read_lock_irq(&tree->lock);
561 finish_wait(&state->wq, &wait);
566 * waits for one or more bits to clear on a range in the state tree.
567 * The range [start, end] is inclusive.
568 * The tree lock is taken by this function
570 int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits)
572 struct extent_state *state;
573 struct rb_node *node;
575 read_lock_irq(&tree->lock);
579 * this search will find all the extents that end after
582 node = tree_search(&tree->state, start);
586 state = rb_entry(node, struct extent_state, rb_node);
588 if (state->start > end)
591 if (state->state & bits) {
592 start = state->start;
593 atomic_inc(&state->refs);
594 wait_on_state(tree, state);
595 free_extent_state(state);
598 start = state->end + 1;
603 if (need_resched()) {
604 read_unlock_irq(&tree->lock);
606 read_lock_irq(&tree->lock);
610 read_unlock_irq(&tree->lock);
613 EXPORT_SYMBOL(wait_extent_bit);
616 * set some bits on a range in the tree. This may require allocations
617 * or sleeping, so the gfp mask is used to indicate what is allowed.
619 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
620 * range already has the desired bits set. The start of the existing
621 * range is returned in failed_start in this case.
623 * [start, end] is inclusive
624 * This takes the tree lock.
626 int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits,
627 int exclusive, u64 *failed_start, gfp_t mask)
629 struct extent_state *state;
630 struct extent_state *prealloc = NULL;
631 struct rb_node *node;
638 if (!prealloc && (mask & __GFP_WAIT)) {
639 prealloc = alloc_extent_state(mask);
644 write_lock_irqsave(&tree->lock, flags);
646 * this search will find all the extents that end after
649 node = tree_search(&tree->state, start);
651 err = insert_state(tree, prealloc, start, end, bits);
653 BUG_ON(err == -EEXIST);
657 state = rb_entry(node, struct extent_state, rb_node);
658 last_start = state->start;
659 last_end = state->end;
662 * | ---- desired range ---- |
665 * Just lock what we found and keep going
667 if (state->start == start && state->end <= end) {
668 set = state->state & bits;
669 if (set && exclusive) {
670 *failed_start = state->start;
674 state->state |= bits;
675 start = state->end + 1;
676 merge_state(tree, state);
681 * | ---- desired range ---- |
684 * | ------------- state -------------- |
686 * We need to split the extent we found, and may flip bits on
689 * If the extent we found extends past our
690 * range, we just split and search again. It'll get split
691 * again the next time though.
693 * If the extent we found is inside our range, we set the
696 if (state->start < start) {
697 set = state->state & bits;
698 if (exclusive && set) {
699 *failed_start = start;
703 err = split_state(tree, state, prealloc, start);
704 BUG_ON(err == -EEXIST);
708 if (state->end <= end) {
709 state->state |= bits;
710 start = state->end + 1;
711 merge_state(tree, state);
713 start = state->start;
718 * | ---- desired range ---- |
719 * | state | or | state |
721 * There's a hole, we need to insert something in it and
722 * ignore the extent we found.
724 if (state->start > start) {
726 if (end < last_start)
729 this_end = last_start -1;
730 err = insert_state(tree, prealloc, start, this_end,
733 BUG_ON(err == -EEXIST);
736 start = this_end + 1;
740 * | ---- desired range ---- |
742 * We need to split the extent, and set the bit
745 if (state->start <= end && state->end > end) {
746 set = state->state & bits;
747 if (exclusive && set) {
748 *failed_start = start;
752 err = split_state(tree, state, prealloc, end + 1);
753 BUG_ON(err == -EEXIST);
755 prealloc->state |= bits;
756 merge_state(tree, prealloc);
764 write_unlock_irqrestore(&tree->lock, flags);
766 free_extent_state(prealloc);
773 write_unlock_irqrestore(&tree->lock, flags);
774 if (mask & __GFP_WAIT)
778 EXPORT_SYMBOL(set_extent_bit);
780 /* wrappers around set/clear extent bit */
781 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
784 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
787 EXPORT_SYMBOL(set_extent_dirty);
789 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end,
792 return set_extent_bit(tree, start, end,
793 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL,
796 EXPORT_SYMBOL(set_extent_delalloc);
798 int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
801 return clear_extent_bit(tree, start, end,
802 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask);
804 EXPORT_SYMBOL(clear_extent_dirty);
806 int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end,
809 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
812 EXPORT_SYMBOL(set_extent_new);
814 int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end,
817 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask);
819 EXPORT_SYMBOL(clear_extent_new);
821 int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end,
824 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
827 EXPORT_SYMBOL(set_extent_uptodate);
829 int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end,
832 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask);
834 EXPORT_SYMBOL(clear_extent_uptodate);
836 int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end,
839 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK,
842 EXPORT_SYMBOL(set_extent_writeback);
844 int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end,
847 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask);
849 EXPORT_SYMBOL(clear_extent_writeback);
851 int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end)
853 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
855 EXPORT_SYMBOL(wait_on_extent_writeback);
858 * locks a range in ascending order, waiting for any locked regions
859 * it hits on the way. [start,end] are inclusive, and this will sleep.
861 int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask)
866 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
867 &failed_start, mask);
868 if (err == -EEXIST && (mask & __GFP_WAIT)) {
869 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
870 start = failed_start;
874 WARN_ON(start > end);
878 EXPORT_SYMBOL(lock_extent);
880 int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end,
883 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask);
885 EXPORT_SYMBOL(unlock_extent);
888 * helper function to set pages and extents in the tree dirty
890 int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end)
892 unsigned long index = start >> PAGE_CACHE_SHIFT;
893 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
896 while (index <= end_index) {
897 page = find_get_page(tree->mapping, index);
899 __set_page_dirty_nobuffers(page);
900 page_cache_release(page);
903 set_extent_dirty(tree, start, end, GFP_NOFS);
906 EXPORT_SYMBOL(set_range_dirty);
909 * helper function to set both pages and extents in the tree writeback
911 int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end)
913 unsigned long index = start >> PAGE_CACHE_SHIFT;
914 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
917 while (index <= end_index) {
918 page = find_get_page(tree->mapping, index);
920 set_page_writeback(page);
921 page_cache_release(page);
924 set_extent_writeback(tree, start, end, GFP_NOFS);
927 EXPORT_SYMBOL(set_range_writeback);
929 u64 find_lock_delalloc_range(struct extent_map_tree *tree,
930 u64 start, u64 lock_start, u64 *end, u64 max_bytes)
932 struct rb_node *node;
933 struct extent_state *state;
934 u64 cur_start = start;
938 write_lock_irq(&tree->lock);
940 * this search will find all the extents that end after
944 node = tree_search(&tree->state, cur_start);
945 if (!node || IS_ERR(node)) {
950 state = rb_entry(node, struct extent_state, rb_node);
951 if (state->start != cur_start) {
954 if (!(state->state & EXTENT_DELALLOC)) {
957 if (state->start >= lock_start) {
958 if (state->state & EXTENT_LOCKED) {
960 atomic_inc(&state->refs);
961 write_unlock_irq(&tree->lock);
963 write_lock_irq(&tree->lock);
964 finish_wait(&state->wq, &wait);
965 free_extent_state(state);
968 state->state |= EXTENT_LOCKED;
972 cur_start = state->end + 1;
973 node = rb_next(node);
976 total_bytes = state->end - state->start + 1;
977 if (total_bytes >= max_bytes)
981 write_unlock_irq(&tree->lock);
986 * helper function to lock both pages and extents in the tree.
987 * pages must be locked first.
989 int lock_range(struct extent_map_tree *tree, u64 start, u64 end)
991 unsigned long index = start >> PAGE_CACHE_SHIFT;
992 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
996 while (index <= end_index) {
997 page = grab_cache_page(tree->mapping, index);
1003 err = PTR_ERR(page);
1008 lock_extent(tree, start, end, GFP_NOFS);
1013 * we failed above in getting the page at 'index', so we undo here
1014 * up to but not including the page at 'index'
1017 index = start >> PAGE_CACHE_SHIFT;
1018 while (index < end_index) {
1019 page = find_get_page(tree->mapping, index);
1021 page_cache_release(page);
1026 EXPORT_SYMBOL(lock_range);
1029 * helper function to unlock both pages and extents in the tree.
1031 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end)
1033 unsigned long index = start >> PAGE_CACHE_SHIFT;
1034 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1037 while (index <= end_index) {
1038 page = find_get_page(tree->mapping, index);
1040 page_cache_release(page);
1043 unlock_extent(tree, start, end, GFP_NOFS);
1046 EXPORT_SYMBOL(unlock_range);
1048 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private)
1050 struct rb_node *node;
1051 struct extent_state *state;
1054 write_lock_irq(&tree->lock);
1056 * this search will find all the extents that end after
1059 node = tree_search(&tree->state, start);
1060 if (!node || IS_ERR(node)) {
1064 state = rb_entry(node, struct extent_state, rb_node);
1065 if (state->start != start) {
1069 state->private = private;
1071 write_unlock_irq(&tree->lock);
1076 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private)
1078 struct rb_node *node;
1079 struct extent_state *state;
1082 read_lock_irq(&tree->lock);
1084 * this search will find all the extents that end after
1087 node = tree_search(&tree->state, start);
1088 if (!node || IS_ERR(node)) {
1092 state = rb_entry(node, struct extent_state, rb_node);
1093 if (state->start != start) {
1097 *private = state->private;
1099 read_unlock_irq(&tree->lock);
1104 * searches a range in the state tree for a given mask.
1105 * If 'filled' == 1, this returns 1 only if ever extent in the tree
1106 * has the bits set. Otherwise, 1 is returned if any bit in the
1107 * range is found set.
1109 static int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end,
1110 int bits, int filled)
1112 struct extent_state *state = NULL;
1113 struct rb_node *node;
1116 read_lock_irq(&tree->lock);
1117 node = tree_search(&tree->state, start);
1118 while (node && start <= end) {
1119 state = rb_entry(node, struct extent_state, rb_node);
1120 if (state->start > end)
1123 if (filled && state->start > start) {
1127 if (state->state & bits) {
1131 } else if (filled) {
1135 start = state->end + 1;
1138 node = rb_next(node);
1140 read_unlock_irq(&tree->lock);
1145 * helper function to set a given page up to date if all the
1146 * extents in the tree for that page are up to date
1148 static int check_page_uptodate(struct extent_map_tree *tree,
1151 u64 start = page->index << PAGE_CACHE_SHIFT;
1152 u64 end = start + PAGE_CACHE_SIZE - 1;
1153 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
1154 SetPageUptodate(page);
1159 * helper function to unlock a page if all the extents in the tree
1160 * for that page are unlocked
1162 static int check_page_locked(struct extent_map_tree *tree,
1165 u64 start = page->index << PAGE_CACHE_SHIFT;
1166 u64 end = start + PAGE_CACHE_SIZE - 1;
1167 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
1173 * helper function to end page writeback if all the extents
1174 * in the tree for that page are done with writeback
1176 static int check_page_writeback(struct extent_map_tree *tree,
1179 u64 start = page->index << PAGE_CACHE_SHIFT;
1180 u64 end = start + PAGE_CACHE_SIZE - 1;
1181 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0))
1182 end_page_writeback(page);
1186 /* lots and lots of room for performance fixes in the end_bio funcs */
1189 * after a writepage IO is done, we need to:
1190 * clear the uptodate bits on error
1191 * clear the writeback bits in the extent tree for this IO
1192 * end_page_writeback if the page has no more pending IO
1194 * Scheduling is not allowed, so the extent state tree is expected
1195 * to have one and only one object corresponding to this IO.
1197 static int end_bio_extent_writepage(struct bio *bio,
1198 unsigned int bytes_done, int err)
1200 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1201 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1202 struct extent_map_tree *tree = bio->bi_private;
1211 struct page *page = bvec->bv_page;
1212 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1213 end = start + bvec->bv_len - 1;
1215 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1220 if (--bvec >= bio->bi_io_vec)
1221 prefetchw(&bvec->bv_page->flags);
1224 clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
1225 ClearPageUptodate(page);
1228 clear_extent_writeback(tree, start, end, GFP_ATOMIC);
1231 end_page_writeback(page);
1233 check_page_writeback(tree, page);
1234 } while (bvec >= bio->bi_io_vec);
1241 * after a readpage IO is done, we need to:
1242 * clear the uptodate bits on error
1243 * set the uptodate bits if things worked
1244 * set the page up to date if all extents in the tree are uptodate
1245 * clear the lock bit in the extent tree
1246 * unlock the page if there are no other extents locked for it
1248 * Scheduling is not allowed, so the extent state tree is expected
1249 * to have one and only one object corresponding to this IO.
1251 static int end_bio_extent_readpage(struct bio *bio,
1252 unsigned int bytes_done, int err)
1254 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1255 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1256 struct extent_map_tree *tree = bio->bi_private;
1266 struct page *page = bvec->bv_page;
1267 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1268 end = start + bvec->bv_len - 1;
1270 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1275 if (--bvec >= bio->bi_io_vec)
1276 prefetchw(&bvec->bv_page->flags);
1278 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
1279 ret = tree->ops->readpage_end_io_hook(page, start, end);
1284 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1286 SetPageUptodate(page);
1288 check_page_uptodate(tree, page);
1290 ClearPageUptodate(page);
1294 unlock_extent(tree, start, end, GFP_ATOMIC);
1299 check_page_locked(tree, page);
1300 } while (bvec >= bio->bi_io_vec);
1307 * IO done from prepare_write is pretty simple, we just unlock
1308 * the structs in the extent tree when done, and set the uptodate bits
1311 static int end_bio_extent_preparewrite(struct bio *bio,
1312 unsigned int bytes_done, int err)
1314 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1315 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1316 struct extent_map_tree *tree = bio->bi_private;
1324 struct page *page = bvec->bv_page;
1325 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1326 end = start + bvec->bv_len - 1;
1328 if (--bvec >= bio->bi_io_vec)
1329 prefetchw(&bvec->bv_page->flags);
1332 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1334 ClearPageUptodate(page);
1338 unlock_extent(tree, start, end, GFP_ATOMIC);
1340 } while (bvec >= bio->bi_io_vec);
1346 static int submit_extent_page(int rw, struct extent_map_tree *tree,
1347 struct page *page, sector_t sector,
1348 size_t size, unsigned long offset,
1349 struct block_device *bdev,
1350 bio_end_io_t end_io_func)
1355 bio = bio_alloc(GFP_NOIO, 1);
1357 bio->bi_sector = sector;
1358 bio->bi_bdev = bdev;
1359 bio->bi_io_vec[0].bv_page = page;
1360 bio->bi_io_vec[0].bv_len = size;
1361 bio->bi_io_vec[0].bv_offset = offset;
1365 bio->bi_size = size;
1367 bio->bi_end_io = end_io_func;
1368 bio->bi_private = tree;
1371 submit_bio(rw, bio);
1373 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1381 * basic readpage implementation. Locked extent state structs are inserted
1382 * into the tree that are removed when the IO is done (by the end_io
1385 int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
1386 get_extent_t *get_extent)
1388 struct inode *inode = page->mapping->host;
1389 u64 start = page->index << PAGE_CACHE_SHIFT;
1390 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1394 u64 last_byte = i_size_read(inode);
1398 struct extent_map *em;
1399 struct block_device *bdev;
1402 size_t page_offset = 0;
1404 size_t blocksize = inode->i_sb->s_blocksize;
1406 if (!PagePrivate(page)) {
1407 SetPagePrivate(page);
1408 WARN_ON(!page->mapping->a_ops->invalidatepage);
1409 set_page_private(page, 1);
1410 page_cache_get(page);
1414 lock_extent(tree, start, end, GFP_NOFS);
1416 while (cur <= end) {
1417 if (cur >= last_byte) {
1418 iosize = PAGE_CACHE_SIZE - page_offset;
1419 zero_user_page(page, page_offset, iosize, KM_USER0);
1420 set_extent_uptodate(tree, cur, cur + iosize - 1,
1422 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1425 em = get_extent(inode, page, page_offset, cur, end, 0);
1426 if (IS_ERR(em) || !em) {
1428 unlock_extent(tree, cur, end, GFP_NOFS);
1432 extent_offset = cur - em->start;
1433 BUG_ON(em->end < cur);
1436 iosize = min(em->end - cur, end - cur) + 1;
1437 cur_end = min(em->end, end);
1438 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
1439 sector = (em->block_start + extent_offset) >> 9;
1441 block_start = em->block_start;
1442 free_extent_map(em);
1445 /* we've found a hole, just zero and go on */
1446 if (block_start == 0) {
1447 zero_user_page(page, page_offset, iosize, KM_USER0);
1448 set_extent_uptodate(tree, cur, cur + iosize - 1,
1450 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1452 page_offset += iosize;
1455 /* the get_extent function already copied into the page */
1456 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
1457 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1459 page_offset += iosize;
1464 if (tree->ops && tree->ops->readpage_io_hook) {
1465 ret = tree->ops->readpage_io_hook(page, cur,
1469 ret = submit_extent_page(READ, tree, page,
1470 sector, iosize, page_offset,
1471 bdev, end_bio_extent_readpage);
1476 page_offset += iosize;
1480 if (!PageError(page))
1481 SetPageUptodate(page);
1486 EXPORT_SYMBOL(extent_read_full_page);
1489 * the writepage semantics are similar to regular writepage. extent
1490 * records are inserted to lock ranges in the tree, and as dirty areas
1491 * are found, they are marked writeback. Then the lock bits are removed
1492 * and the end_io handler clears the writeback ranges
1494 int extent_write_full_page(struct extent_map_tree *tree, struct page *page,
1495 get_extent_t *get_extent,
1496 struct writeback_control *wbc)
1498 struct inode *inode = page->mapping->host;
1499 u64 start = page->index << PAGE_CACHE_SHIFT;
1500 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1504 u64 last_byte = i_size_read(inode);
1507 struct extent_map *em;
1508 struct block_device *bdev;
1511 size_t page_offset = 0;
1514 loff_t i_size = i_size_read(inode);
1515 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
1519 WARN_ON(!PageLocked(page));
1520 if (page->index > end_index) {
1521 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
1526 if (page->index == end_index) {
1527 size_t offset = i_size & (PAGE_CACHE_SIZE - 1);
1528 zero_user_page(page, offset,
1529 PAGE_CACHE_SIZE - offset, KM_USER0);
1532 if (!PagePrivate(page)) {
1533 SetPagePrivate(page);
1534 set_page_private(page, 1);
1535 WARN_ON(!page->mapping->a_ops->invalidatepage);
1536 page_cache_get(page);
1539 lock_extent(tree, start, page_end, GFP_NOFS);
1540 nr_delalloc = find_lock_delalloc_range(tree, start, page_end + 1,
1544 tree->ops->fill_delalloc(inode, start, delalloc_end);
1545 if (delalloc_end >= page_end + 1) {
1546 clear_extent_bit(tree, page_end + 1, delalloc_end,
1547 EXTENT_LOCKED | EXTENT_DELALLOC,
1550 clear_extent_bit(tree, start, page_end, EXTENT_DELALLOC,
1552 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
1553 printk("found delalloc bits after clear extent_bit\n");
1555 } else if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
1556 printk("found delalloc bits after find_delalloc_range returns 0\n");
1560 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
1561 printk("found delalloc bits after lock_extent\n");
1564 if (last_byte <= start) {
1565 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
1569 set_extent_uptodate(tree, start, page_end, GFP_NOFS);
1570 blocksize = inode->i_sb->s_blocksize;
1572 while (cur <= end) {
1573 if (cur >= last_byte) {
1574 clear_extent_dirty(tree, cur, page_end, GFP_NOFS);
1577 em = get_extent(inode, page, page_offset, cur, end, 0);
1578 if (IS_ERR(em) || !em) {
1583 extent_offset = cur - em->start;
1584 BUG_ON(em->end < cur);
1586 iosize = min(em->end - cur, end - cur) + 1;
1587 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
1588 sector = (em->block_start + extent_offset) >> 9;
1590 block_start = em->block_start;
1591 free_extent_map(em);
1594 if (block_start == 0 || block_start == EXTENT_MAP_INLINE) {
1595 clear_extent_dirty(tree, cur,
1596 cur + iosize - 1, GFP_NOFS);
1598 page_offset += iosize;
1602 /* leave this out until we have a page_mkwrite call */
1603 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
1606 page_offset += iosize;
1609 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
1610 ret = tree->ops->writepage_io_hook(page, cur, cur + iosize - 1);
1614 set_range_writeback(tree, cur, cur + iosize - 1);
1615 ret = submit_extent_page(WRITE, tree, page, sector,
1616 iosize, page_offset, bdev,
1617 end_bio_extent_writepage);
1622 page_offset += iosize;
1626 WARN_ON(test_range_bit(tree, start, page_end, EXTENT_DIRTY, 0));
1627 unlock_extent(tree, start, page_end, GFP_NOFS);
1631 EXPORT_SYMBOL(extent_write_full_page);
1634 * basic invalidatepage code, this waits on any locked or writeback
1635 * ranges corresponding to the page, and then deletes any extent state
1636 * records from the tree
1638 int extent_invalidatepage(struct extent_map_tree *tree,
1639 struct page *page, unsigned long offset)
1641 u64 start = (page->index << PAGE_CACHE_SHIFT);
1642 u64 end = start + PAGE_CACHE_SIZE - 1;
1643 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
1645 start += (offset + blocksize -1) & ~(blocksize - 1);
1649 lock_extent(tree, start, end, GFP_NOFS);
1650 wait_on_extent_writeback(tree, start, end);
1651 clear_extent_bit(tree, start, end,
1652 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
1656 EXPORT_SYMBOL(extent_invalidatepage);
1659 * simple commit_write call, set_range_dirty is used to mark both
1660 * the pages and the extent records as dirty
1662 int extent_commit_write(struct extent_map_tree *tree,
1663 struct inode *inode, struct page *page,
1664 unsigned from, unsigned to)
1666 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1668 if (!PagePrivate(page)) {
1669 SetPagePrivate(page);
1670 set_page_private(page, 1);
1671 WARN_ON(!page->mapping->a_ops->invalidatepage);
1672 page_cache_get(page);
1675 set_page_dirty(page);
1677 if (pos > inode->i_size) {
1678 i_size_write(inode, pos);
1679 mark_inode_dirty(inode);
1683 EXPORT_SYMBOL(extent_commit_write);
1685 int extent_prepare_write(struct extent_map_tree *tree,
1686 struct inode *inode, struct page *page,
1687 unsigned from, unsigned to, get_extent_t *get_extent)
1689 u64 page_start = page->index << PAGE_CACHE_SHIFT;
1690 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
1692 u64 orig_block_start;
1695 struct extent_map *em;
1696 unsigned blocksize = 1 << inode->i_blkbits;
1697 size_t page_offset = 0;
1698 size_t block_off_start;
1699 size_t block_off_end;
1705 if (!PagePrivate(page)) {
1706 SetPagePrivate(page);
1707 set_page_private(page, 1);
1708 WARN_ON(!page->mapping->a_ops->invalidatepage);
1709 page_cache_get(page);
1711 block_start = (page_start + from) & ~((u64)blocksize - 1);
1712 block_end = (page_start + to - 1) | (blocksize - 1);
1713 orig_block_start = block_start;
1715 lock_extent(tree, page_start, page_end, GFP_NOFS);
1716 while(block_start <= block_end) {
1717 em = get_extent(inode, page, page_offset, block_start,
1719 if (IS_ERR(em) || !em) {
1722 cur_end = min(block_end, em->end);
1723 block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
1724 block_off_end = block_off_start + blocksize;
1725 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
1727 if (!PageUptodate(page) && isnew &&
1728 (block_off_end > to || block_off_start < from)) {
1731 kaddr = kmap_atomic(page, KM_USER0);
1732 if (block_off_end > to)
1733 memset(kaddr + to, 0, block_off_end - to);
1734 if (block_off_start < from)
1735 memset(kaddr + block_off_start, 0,
1736 from - block_off_start);
1737 flush_dcache_page(page);
1738 kunmap_atomic(kaddr, KM_USER0);
1740 if (!isnew && !PageUptodate(page) &&
1741 (block_off_end > to || block_off_start < from) &&
1742 !test_range_bit(tree, block_start, cur_end,
1743 EXTENT_UPTODATE, 1)) {
1745 u64 extent_offset = block_start - em->start;
1747 sector = (em->block_start + extent_offset) >> 9;
1748 iosize = (cur_end - block_start + blocksize - 1) &
1749 ~((u64)blocksize - 1);
1751 * we've already got the extent locked, but we
1752 * need to split the state such that our end_bio
1753 * handler can clear the lock.
1755 set_extent_bit(tree, block_start,
1756 block_start + iosize - 1,
1757 EXTENT_LOCKED, 0, NULL, GFP_NOFS);
1758 ret = submit_extent_page(READ, tree, page,
1759 sector, iosize, page_offset, em->bdev,
1760 end_bio_extent_preparewrite);
1762 block_start = block_start + iosize;
1764 set_extent_uptodate(tree, block_start, cur_end,
1766 unlock_extent(tree, block_start, cur_end, GFP_NOFS);
1767 block_start = cur_end + 1;
1769 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
1770 free_extent_map(em);
1773 wait_extent_bit(tree, orig_block_start,
1774 block_end, EXTENT_LOCKED);
1776 check_page_uptodate(tree, page);
1778 /* FIXME, zero out newly allocated blocks on error */
1781 EXPORT_SYMBOL(extent_prepare_write);
1784 * a helper for releasepage. As long as there are no locked extents
1785 * in the range corresponding to the page, both state records and extent
1786 * map records are removed
1788 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page)
1790 struct extent_map *em;
1791 u64 start = page->index << PAGE_CACHE_SHIFT;
1792 u64 end = start + PAGE_CACHE_SIZE - 1;
1793 u64 orig_start = start;
1796 while (start <= end) {
1797 em = lookup_extent_mapping(tree, start, end);
1798 if (!em || IS_ERR(em))
1800 if (!test_range_bit(tree, em->start, em->end,
1801 EXTENT_LOCKED, 0)) {
1802 remove_extent_mapping(tree, em);
1803 /* once for the rb tree */
1804 free_extent_map(em);
1806 start = em->end + 1;
1808 free_extent_map(em);
1810 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0))
1813 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE,
1817 EXPORT_SYMBOL(try_release_extent_mapping);