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;
463 if (!prealloc && (mask & __GFP_WAIT)) {
464 prealloc = alloc_extent_state(mask);
469 write_lock_irq(&tree->lock);
471 * this search will find the extents that end after
474 node = tree_search(&tree->state, start);
477 state = rb_entry(node, struct extent_state, rb_node);
478 if (state->start > end)
480 WARN_ON(state->end < start);
483 * | ---- desired range ---- |
485 * | ------------- state -------------- |
487 * We need to split the extent we found, and may flip
488 * bits on second half.
490 * If the extent we found extends past our range, we
491 * just split and search again. It'll get split again
492 * the next time though.
494 * If the extent we found is inside our range, we clear
495 * the desired bit on it.
498 if (state->start < start) {
499 err = split_state(tree, state, prealloc, start);
500 BUG_ON(err == -EEXIST);
504 if (state->end <= end) {
505 start = state->end + 1;
506 set |= clear_state_bit(tree, state, bits,
509 start = state->start;
514 * | ---- desired range ---- |
516 * We need to split the extent, and clear the bit
519 if (state->start <= end && state->end > end) {
520 err = split_state(tree, state, prealloc, end + 1);
521 BUG_ON(err == -EEXIST);
525 set |= clear_state_bit(tree, prealloc, bits,
531 start = state->end + 1;
532 set |= clear_state_bit(tree, state, bits, wake, delete);
536 write_unlock_irq(&tree->lock);
538 free_extent_state(prealloc);
545 write_unlock_irq(&tree->lock);
546 if (mask & __GFP_WAIT)
550 EXPORT_SYMBOL(clear_extent_bit);
552 static int wait_on_state(struct extent_map_tree *tree,
553 struct extent_state *state)
556 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
557 read_unlock_irq(&tree->lock);
559 read_lock_irq(&tree->lock);
560 finish_wait(&state->wq, &wait);
565 * waits for one or more bits to clear on a range in the state tree.
566 * The range [start, end] is inclusive.
567 * The tree lock is taken by this function
569 int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits)
571 struct extent_state *state;
572 struct rb_node *node;
574 read_lock_irq(&tree->lock);
578 * this search will find all the extents that end after
581 node = tree_search(&tree->state, start);
585 state = rb_entry(node, struct extent_state, rb_node);
587 if (state->start > end)
590 if (state->state & bits) {
591 start = state->start;
592 atomic_inc(&state->refs);
593 wait_on_state(tree, state);
594 free_extent_state(state);
597 start = state->end + 1;
602 if (need_resched()) {
603 read_unlock_irq(&tree->lock);
605 read_lock_irq(&tree->lock);
609 read_unlock_irq(&tree->lock);
612 EXPORT_SYMBOL(wait_extent_bit);
615 * set some bits on a range in the tree. This may require allocations
616 * or sleeping, so the gfp mask is used to indicate what is allowed.
618 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
619 * range already has the desired bits set. The start of the existing
620 * range is returned in failed_start in this case.
622 * [start, end] is inclusive
623 * This takes the tree lock.
625 int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits,
626 int exclusive, u64 *failed_start, gfp_t mask)
628 struct extent_state *state;
629 struct extent_state *prealloc = NULL;
630 struct rb_node *node;
636 if (!prealloc && (mask & __GFP_WAIT)) {
637 prealloc = alloc_extent_state(mask);
642 write_lock_irq(&tree->lock);
644 * this search will find all the extents that end after
647 node = tree_search(&tree->state, start);
649 err = insert_state(tree, prealloc, start, end, bits);
651 BUG_ON(err == -EEXIST);
655 state = rb_entry(node, struct extent_state, rb_node);
656 last_start = state->start;
657 last_end = state->end;
660 * | ---- desired range ---- |
663 * Just lock what we found and keep going
665 if (state->start == start && state->end <= end) {
666 set = state->state & bits;
667 if (set && exclusive) {
668 *failed_start = state->start;
672 state->state |= bits;
673 start = state->end + 1;
674 merge_state(tree, state);
679 * | ---- desired range ---- |
682 * | ------------- state -------------- |
684 * We need to split the extent we found, and may flip bits on
687 * If the extent we found extends past our
688 * range, we just split and search again. It'll get split
689 * again the next time though.
691 * If the extent we found is inside our range, we set the
694 if (state->start < start) {
695 set = state->state & bits;
696 if (exclusive && set) {
697 *failed_start = start;
701 err = split_state(tree, state, prealloc, start);
702 BUG_ON(err == -EEXIST);
706 if (state->end <= end) {
707 state->state |= bits;
708 start = state->end + 1;
709 merge_state(tree, state);
711 start = state->start;
716 * | ---- desired range ---- |
717 * | state | or | state |
719 * There's a hole, we need to insert something in it and
720 * ignore the extent we found.
722 if (state->start > start) {
724 if (end < last_start)
727 this_end = last_start -1;
728 err = insert_state(tree, prealloc, start, this_end,
731 BUG_ON(err == -EEXIST);
734 start = this_end + 1;
738 * | ---- desired range ---- |
740 * We need to split the extent, and set the bit
743 if (state->start <= end && state->end > end) {
744 set = state->state & bits;
745 if (exclusive && set) {
746 *failed_start = start;
750 err = split_state(tree, state, prealloc, end + 1);
751 BUG_ON(err == -EEXIST);
753 prealloc->state |= bits;
754 merge_state(tree, prealloc);
762 write_unlock_irq(&tree->lock);
764 free_extent_state(prealloc);
771 write_unlock_irq(&tree->lock);
772 if (mask & __GFP_WAIT)
776 EXPORT_SYMBOL(set_extent_bit);
778 /* wrappers around set/clear extent bit */
779 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
782 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
785 EXPORT_SYMBOL(set_extent_dirty);
787 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end,
790 return set_extent_bit(tree, start, end,
791 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL,
794 EXPORT_SYMBOL(set_extent_delalloc);
796 int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
799 return clear_extent_bit(tree, start, end,
800 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask);
802 EXPORT_SYMBOL(clear_extent_dirty);
804 int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end,
807 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
810 EXPORT_SYMBOL(set_extent_new);
812 int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end,
815 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask);
817 EXPORT_SYMBOL(clear_extent_new);
819 int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end,
822 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
825 EXPORT_SYMBOL(set_extent_uptodate);
827 int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end,
830 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask);
832 EXPORT_SYMBOL(clear_extent_uptodate);
834 int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end,
837 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK,
840 EXPORT_SYMBOL(set_extent_writeback);
842 int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end,
845 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask);
847 EXPORT_SYMBOL(clear_extent_writeback);
849 int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end)
851 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
853 EXPORT_SYMBOL(wait_on_extent_writeback);
856 * locks a range in ascending order, waiting for any locked regions
857 * it hits on the way. [start,end] are inclusive, and this will sleep.
859 int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask)
864 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
865 &failed_start, mask);
866 if (err == -EEXIST && (mask & __GFP_WAIT)) {
867 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
868 start = failed_start;
872 WARN_ON(start > end);
876 EXPORT_SYMBOL(lock_extent);
878 int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end,
881 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask);
883 EXPORT_SYMBOL(unlock_extent);
886 * helper function to set pages and extents in the tree dirty
888 int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end)
890 unsigned long index = start >> PAGE_CACHE_SHIFT;
891 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
894 while (index <= end_index) {
895 page = find_get_page(tree->mapping, index);
897 __set_page_dirty_nobuffers(page);
898 page_cache_release(page);
901 set_extent_dirty(tree, start, end, GFP_NOFS);
904 EXPORT_SYMBOL(set_range_dirty);
907 * helper function to set both pages and extents in the tree writeback
909 int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end)
911 unsigned long index = start >> PAGE_CACHE_SHIFT;
912 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
915 while (index <= end_index) {
916 page = find_get_page(tree->mapping, index);
918 set_page_writeback(page);
919 page_cache_release(page);
922 set_extent_writeback(tree, start, end, GFP_NOFS);
925 EXPORT_SYMBOL(set_range_writeback);
927 u64 find_lock_delalloc_range(struct extent_map_tree *tree,
928 u64 start, u64 lock_start, u64 *end, u64 max_bytes)
930 struct rb_node *node;
931 struct extent_state *state;
932 u64 cur_start = start;
936 write_lock_irq(&tree->lock);
938 * this search will find all the extents that end after
942 node = tree_search(&tree->state, cur_start);
943 if (!node || IS_ERR(node)) {
948 state = rb_entry(node, struct extent_state, rb_node);
949 if (state->start != cur_start) {
952 if (!(state->state & EXTENT_DELALLOC)) {
955 if (state->start >= lock_start) {
956 if (state->state & EXTENT_LOCKED) {
958 atomic_inc(&state->refs);
959 write_unlock_irq(&tree->lock);
961 write_lock_irq(&tree->lock);
962 finish_wait(&state->wq, &wait);
963 free_extent_state(state);
966 state->state |= EXTENT_LOCKED;
970 cur_start = state->end + 1;
971 node = rb_next(node);
974 total_bytes = state->end - state->start + 1;
975 if (total_bytes >= max_bytes)
979 write_unlock_irq(&tree->lock);
984 * helper function to lock both pages and extents in the tree.
985 * pages must be locked first.
987 int lock_range(struct extent_map_tree *tree, u64 start, u64 end)
989 unsigned long index = start >> PAGE_CACHE_SHIFT;
990 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
994 while (index <= end_index) {
995 page = grab_cache_page(tree->mapping, index);
1001 err = PTR_ERR(page);
1006 lock_extent(tree, start, end, GFP_NOFS);
1011 * we failed above in getting the page at 'index', so we undo here
1012 * up to but not including the page at 'index'
1015 index = start >> PAGE_CACHE_SHIFT;
1016 while (index < end_index) {
1017 page = find_get_page(tree->mapping, index);
1019 page_cache_release(page);
1024 EXPORT_SYMBOL(lock_range);
1027 * helper function to unlock both pages and extents in the tree.
1029 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end)
1031 unsigned long index = start >> PAGE_CACHE_SHIFT;
1032 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1035 while (index <= end_index) {
1036 page = find_get_page(tree->mapping, index);
1038 page_cache_release(page);
1041 unlock_extent(tree, start, end, GFP_NOFS);
1044 EXPORT_SYMBOL(unlock_range);
1046 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private)
1048 struct rb_node *node;
1049 struct extent_state *state;
1052 write_lock_irq(&tree->lock);
1054 * this search will find all the extents that end after
1057 node = tree_search(&tree->state, start);
1058 if (!node || IS_ERR(node)) {
1062 state = rb_entry(node, struct extent_state, rb_node);
1063 if (state->start != start) {
1067 state->private = private;
1069 write_unlock_irq(&tree->lock);
1074 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private)
1076 struct rb_node *node;
1077 struct extent_state *state;
1080 read_lock_irq(&tree->lock);
1082 * this search will find all the extents that end after
1085 node = tree_search(&tree->state, start);
1086 if (!node || IS_ERR(node)) {
1090 state = rb_entry(node, struct extent_state, rb_node);
1091 if (state->start != start) {
1095 *private = state->private;
1097 read_unlock_irq(&tree->lock);
1102 * searches a range in the state tree for a given mask.
1103 * If 'filled' == 1, this returns 1 only if ever extent in the tree
1104 * has the bits set. Otherwise, 1 is returned if any bit in the
1105 * range is found set.
1107 static int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end,
1108 int bits, int filled)
1110 struct extent_state *state = NULL;
1111 struct rb_node *node;
1114 read_lock_irq(&tree->lock);
1115 node = tree_search(&tree->state, start);
1116 while (node && start <= end) {
1117 state = rb_entry(node, struct extent_state, rb_node);
1118 if (state->start > end)
1121 if (filled && state->start > start) {
1125 if (state->state & bits) {
1129 } else if (filled) {
1133 start = state->end + 1;
1136 node = rb_next(node);
1138 read_unlock_irq(&tree->lock);
1143 * helper function to set a given page up to date if all the
1144 * extents in the tree for that page are up to date
1146 static int check_page_uptodate(struct extent_map_tree *tree,
1149 u64 start = page->index << PAGE_CACHE_SHIFT;
1150 u64 end = start + PAGE_CACHE_SIZE - 1;
1151 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
1152 SetPageUptodate(page);
1157 * helper function to unlock a page if all the extents in the tree
1158 * for that page are unlocked
1160 static int check_page_locked(struct extent_map_tree *tree,
1163 u64 start = page->index << PAGE_CACHE_SHIFT;
1164 u64 end = start + PAGE_CACHE_SIZE - 1;
1165 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
1171 * helper function to end page writeback if all the extents
1172 * in the tree for that page are done with writeback
1174 static int check_page_writeback(struct extent_map_tree *tree,
1177 u64 start = page->index << PAGE_CACHE_SHIFT;
1178 u64 end = start + PAGE_CACHE_SIZE - 1;
1179 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0))
1180 end_page_writeback(page);
1184 /* lots and lots of room for performance fixes in the end_bio funcs */
1187 * after a writepage IO is done, we need to:
1188 * clear the uptodate bits on error
1189 * clear the writeback bits in the extent tree for this IO
1190 * end_page_writeback if the page has no more pending IO
1192 * Scheduling is not allowed, so the extent state tree is expected
1193 * to have one and only one object corresponding to this IO.
1195 static int end_bio_extent_writepage(struct bio *bio,
1196 unsigned int bytes_done, int err)
1198 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1199 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1200 struct extent_map_tree *tree = bio->bi_private;
1209 struct page *page = bvec->bv_page;
1210 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1211 end = start + bvec->bv_len - 1;
1213 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1218 if (--bvec >= bio->bi_io_vec)
1219 prefetchw(&bvec->bv_page->flags);
1222 clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
1223 ClearPageUptodate(page);
1226 clear_extent_writeback(tree, start, end, GFP_ATOMIC);
1229 end_page_writeback(page);
1231 check_page_writeback(tree, page);
1232 } while (bvec >= bio->bi_io_vec);
1239 * after a readpage IO is done, we need to:
1240 * clear the uptodate bits on error
1241 * set the uptodate bits if things worked
1242 * set the page up to date if all extents in the tree are uptodate
1243 * clear the lock bit in the extent tree
1244 * unlock the page if there are no other extents locked for it
1246 * Scheduling is not allowed, so the extent state tree is expected
1247 * to have one and only one object corresponding to this IO.
1249 static int end_bio_extent_readpage(struct bio *bio,
1250 unsigned int bytes_done, int err)
1252 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1253 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1254 struct extent_map_tree *tree = bio->bi_private;
1264 struct page *page = bvec->bv_page;
1265 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1266 end = start + bvec->bv_len - 1;
1268 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1273 if (--bvec >= bio->bi_io_vec)
1274 prefetchw(&bvec->bv_page->flags);
1276 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
1277 ret = tree->ops->readpage_end_io_hook(page, start, end);
1282 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1284 SetPageUptodate(page);
1286 check_page_uptodate(tree, page);
1288 ClearPageUptodate(page);
1292 unlock_extent(tree, start, end, GFP_ATOMIC);
1297 check_page_locked(tree, page);
1298 } while (bvec >= bio->bi_io_vec);
1305 * IO done from prepare_write is pretty simple, we just unlock
1306 * the structs in the extent tree when done, and set the uptodate bits
1309 static int end_bio_extent_preparewrite(struct bio *bio,
1310 unsigned int bytes_done, int err)
1312 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1313 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1314 struct extent_map_tree *tree = bio->bi_private;
1322 struct page *page = bvec->bv_page;
1323 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1324 end = start + bvec->bv_len - 1;
1326 if (--bvec >= bio->bi_io_vec)
1327 prefetchw(&bvec->bv_page->flags);
1330 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1332 ClearPageUptodate(page);
1336 unlock_extent(tree, start, end, GFP_ATOMIC);
1338 } while (bvec >= bio->bi_io_vec);
1344 static int submit_extent_page(int rw, struct extent_map_tree *tree,
1345 struct page *page, sector_t sector,
1346 size_t size, unsigned long offset,
1347 struct block_device *bdev,
1348 bio_end_io_t end_io_func)
1353 bio = bio_alloc(GFP_NOIO, 1);
1355 bio->bi_sector = sector;
1356 bio->bi_bdev = bdev;
1357 bio->bi_io_vec[0].bv_page = page;
1358 bio->bi_io_vec[0].bv_len = size;
1359 bio->bi_io_vec[0].bv_offset = offset;
1363 bio->bi_size = size;
1365 bio->bi_end_io = end_io_func;
1366 bio->bi_private = tree;
1369 submit_bio(rw, bio);
1371 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1379 * basic readpage implementation. Locked extent state structs are inserted
1380 * into the tree that are removed when the IO is done (by the end_io
1383 int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
1384 get_extent_t *get_extent)
1386 struct inode *inode = page->mapping->host;
1387 u64 start = page->index << PAGE_CACHE_SHIFT;
1388 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1392 u64 last_byte = i_size_read(inode);
1396 struct extent_map *em;
1397 struct block_device *bdev;
1400 size_t page_offset = 0;
1402 size_t blocksize = inode->i_sb->s_blocksize;
1404 if (!PagePrivate(page)) {
1405 SetPagePrivate(page);
1406 WARN_ON(!page->mapping->a_ops->invalidatepage);
1407 set_page_private(page, 1);
1408 page_cache_get(page);
1412 lock_extent(tree, start, end, GFP_NOFS);
1414 while (cur <= end) {
1415 if (cur >= last_byte) {
1416 iosize = PAGE_CACHE_SIZE - page_offset;
1417 zero_user_page(page, page_offset, iosize, KM_USER0);
1418 set_extent_uptodate(tree, cur, cur + iosize - 1,
1420 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1423 em = get_extent(inode, page, page_offset, cur, end, 0);
1424 if (IS_ERR(em) || !em) {
1426 unlock_extent(tree, cur, end, GFP_NOFS);
1430 extent_offset = cur - em->start;
1431 BUG_ON(em->end < cur);
1434 iosize = min(em->end - cur, end - cur) + 1;
1435 cur_end = min(em->end, end);
1436 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
1437 sector = (em->block_start + extent_offset) >> 9;
1439 block_start = em->block_start;
1440 free_extent_map(em);
1443 /* we've found a hole, just zero and go on */
1444 if (block_start == 0) {
1445 zero_user_page(page, page_offset, iosize, KM_USER0);
1446 set_extent_uptodate(tree, cur, cur + iosize - 1,
1448 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1450 page_offset += iosize;
1453 /* the get_extent function already copied into the page */
1454 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
1455 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1457 page_offset += iosize;
1462 if (tree->ops && tree->ops->readpage_io_hook) {
1463 ret = tree->ops->readpage_io_hook(page, cur,
1467 ret = submit_extent_page(READ, tree, page,
1468 sector, iosize, page_offset,
1469 bdev, end_bio_extent_readpage);
1474 page_offset += iosize;
1478 if (!PageError(page))
1479 SetPageUptodate(page);
1484 EXPORT_SYMBOL(extent_read_full_page);
1487 * the writepage semantics are similar to regular writepage. extent
1488 * records are inserted to lock ranges in the tree, and as dirty areas
1489 * are found, they are marked writeback. Then the lock bits are removed
1490 * and the end_io handler clears the writeback ranges
1492 int extent_write_full_page(struct extent_map_tree *tree, struct page *page,
1493 get_extent_t *get_extent,
1494 struct writeback_control *wbc)
1496 struct inode *inode = page->mapping->host;
1497 u64 start = page->index << PAGE_CACHE_SHIFT;
1498 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1502 u64 last_byte = i_size_read(inode);
1505 struct extent_map *em;
1506 struct block_device *bdev;
1509 size_t page_offset = 0;
1512 loff_t i_size = i_size_read(inode);
1513 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
1517 WARN_ON(!PageLocked(page));
1518 if (page->index > end_index) {
1519 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
1524 if (page->index == end_index) {
1525 size_t offset = i_size & (PAGE_CACHE_SIZE - 1);
1526 zero_user_page(page, offset,
1527 PAGE_CACHE_SIZE - offset, KM_USER0);
1530 if (!PagePrivate(page)) {
1531 SetPagePrivate(page);
1532 set_page_private(page, 1);
1533 WARN_ON(!page->mapping->a_ops->invalidatepage);
1534 page_cache_get(page);
1537 lock_extent(tree, start, page_end, GFP_NOFS);
1538 nr_delalloc = find_lock_delalloc_range(tree, start, page_end + 1,
1542 tree->ops->fill_delalloc(inode, start, delalloc_end);
1543 if (delalloc_end >= page_end + 1) {
1544 clear_extent_bit(tree, page_end + 1, delalloc_end,
1545 EXTENT_LOCKED | EXTENT_DELALLOC,
1548 clear_extent_bit(tree, start, page_end, EXTENT_DELALLOC,
1550 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
1551 printk("found delalloc bits after clear extent_bit\n");
1553 } else if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
1554 printk("found delalloc bits after find_delalloc_range returns 0\n");
1558 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
1559 printk("found delalloc bits after lock_extent\n");
1562 if (last_byte <= start) {
1563 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
1567 set_extent_uptodate(tree, start, page_end, GFP_NOFS);
1568 blocksize = inode->i_sb->s_blocksize;
1570 while (cur <= end) {
1571 if (cur >= last_byte) {
1572 clear_extent_dirty(tree, cur, page_end, GFP_NOFS);
1575 em = get_extent(inode, page, page_offset, cur, end, 0);
1576 if (IS_ERR(em) || !em) {
1581 extent_offset = cur - em->start;
1582 BUG_ON(em->end < cur);
1584 iosize = min(em->end - cur, end - cur) + 1;
1585 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
1586 sector = (em->block_start + extent_offset) >> 9;
1588 block_start = em->block_start;
1589 free_extent_map(em);
1592 if (block_start == 0 || block_start == EXTENT_MAP_INLINE) {
1593 clear_extent_dirty(tree, cur,
1594 cur + iosize - 1, GFP_NOFS);
1596 page_offset += iosize;
1600 /* leave this out until we have a page_mkwrite call */
1601 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
1604 page_offset += iosize;
1607 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
1608 ret = tree->ops->writepage_io_hook(page, cur, cur + iosize - 1);
1612 set_range_writeback(tree, cur, cur + iosize - 1);
1613 ret = submit_extent_page(WRITE, tree, page, sector,
1614 iosize, page_offset, bdev,
1615 end_bio_extent_writepage);
1620 page_offset += iosize;
1624 WARN_ON(test_range_bit(tree, start, page_end, EXTENT_DIRTY, 0));
1625 unlock_extent(tree, start, page_end, GFP_NOFS);
1629 EXPORT_SYMBOL(extent_write_full_page);
1632 * basic invalidatepage code, this waits on any locked or writeback
1633 * ranges corresponding to the page, and then deletes any extent state
1634 * records from the tree
1636 int extent_invalidatepage(struct extent_map_tree *tree,
1637 struct page *page, unsigned long offset)
1639 u64 start = (page->index << PAGE_CACHE_SHIFT);
1640 u64 end = start + PAGE_CACHE_SIZE - 1;
1641 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
1643 start += (offset + blocksize -1) & ~(blocksize - 1);
1647 lock_extent(tree, start, end, GFP_NOFS);
1648 wait_on_extent_writeback(tree, start, end);
1649 clear_extent_bit(tree, start, end,
1650 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
1654 EXPORT_SYMBOL(extent_invalidatepage);
1657 * simple commit_write call, set_range_dirty is used to mark both
1658 * the pages and the extent records as dirty
1660 int extent_commit_write(struct extent_map_tree *tree,
1661 struct inode *inode, struct page *page,
1662 unsigned from, unsigned to)
1664 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1666 if (!PagePrivate(page)) {
1667 SetPagePrivate(page);
1668 set_page_private(page, 1);
1669 WARN_ON(!page->mapping->a_ops->invalidatepage);
1670 page_cache_get(page);
1673 set_page_dirty(page);
1675 if (pos > inode->i_size) {
1676 i_size_write(inode, pos);
1677 mark_inode_dirty(inode);
1681 EXPORT_SYMBOL(extent_commit_write);
1683 int extent_prepare_write(struct extent_map_tree *tree,
1684 struct inode *inode, struct page *page,
1685 unsigned from, unsigned to, get_extent_t *get_extent)
1687 u64 page_start = page->index << PAGE_CACHE_SHIFT;
1688 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
1690 u64 orig_block_start;
1693 struct extent_map *em;
1694 unsigned blocksize = 1 << inode->i_blkbits;
1695 size_t page_offset = 0;
1696 size_t block_off_start;
1697 size_t block_off_end;
1703 if (!PagePrivate(page)) {
1704 SetPagePrivate(page);
1705 set_page_private(page, 1);
1706 WARN_ON(!page->mapping->a_ops->invalidatepage);
1707 page_cache_get(page);
1709 block_start = (page_start + from) & ~((u64)blocksize - 1);
1710 block_end = (page_start + to - 1) | (blocksize - 1);
1711 orig_block_start = block_start;
1713 lock_extent(tree, page_start, page_end, GFP_NOFS);
1714 while(block_start <= block_end) {
1715 em = get_extent(inode, page, page_offset, block_start,
1717 if (IS_ERR(em) || !em) {
1720 cur_end = min(block_end, em->end);
1721 block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
1722 block_off_end = block_off_start + blocksize;
1723 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
1725 if (!PageUptodate(page) && isnew &&
1726 (block_off_end > to || block_off_start < from)) {
1729 kaddr = kmap_atomic(page, KM_USER0);
1730 if (block_off_end > to)
1731 memset(kaddr + to, 0, block_off_end - to);
1732 if (block_off_start < from)
1733 memset(kaddr + block_off_start, 0,
1734 from - block_off_start);
1735 flush_dcache_page(page);
1736 kunmap_atomic(kaddr, KM_USER0);
1738 if (!isnew && !PageUptodate(page) &&
1739 (block_off_end > to || block_off_start < from) &&
1740 !test_range_bit(tree, block_start, cur_end,
1741 EXTENT_UPTODATE, 1)) {
1743 u64 extent_offset = block_start - em->start;
1745 sector = (em->block_start + extent_offset) >> 9;
1746 iosize = (cur_end - block_start + blocksize - 1) &
1747 ~((u64)blocksize - 1);
1749 * we've already got the extent locked, but we
1750 * need to split the state such that our end_bio
1751 * handler can clear the lock.
1753 set_extent_bit(tree, block_start,
1754 block_start + iosize - 1,
1755 EXTENT_LOCKED, 0, NULL, GFP_NOFS);
1756 ret = submit_extent_page(READ, tree, page,
1757 sector, iosize, page_offset, em->bdev,
1758 end_bio_extent_preparewrite);
1760 block_start = block_start + iosize;
1762 set_extent_uptodate(tree, block_start, cur_end,
1764 unlock_extent(tree, block_start, cur_end, GFP_NOFS);
1765 block_start = cur_end + 1;
1767 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
1768 free_extent_map(em);
1771 wait_extent_bit(tree, orig_block_start,
1772 block_end, EXTENT_LOCKED);
1774 check_page_uptodate(tree, page);
1776 /* FIXME, zero out newly allocated blocks on error */
1779 EXPORT_SYMBOL(extent_prepare_write);
1782 * a helper for releasepage. As long as there are no locked extents
1783 * in the range corresponding to the page, both state records and extent
1784 * map records are removed
1786 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page)
1788 struct extent_map *em;
1789 u64 start = page->index << PAGE_CACHE_SHIFT;
1790 u64 end = start + PAGE_CACHE_SIZE - 1;
1791 u64 orig_start = start;
1794 while (start <= end) {
1795 em = lookup_extent_mapping(tree, start, end);
1796 if (!em || IS_ERR(em))
1798 if (!test_range_bit(tree, em->start, em->end,
1799 EXTENT_LOCKED, 0)) {
1800 remove_extent_mapping(tree, em);
1801 /* once for the rb tree */
1802 free_extent_map(em);
1804 start = em->end + 1;
1806 free_extent_map(em);
1808 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0))
1811 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE,
1815 EXPORT_SYMBOL(try_release_extent_mapping);