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 static struct kmem_cache *extent_map_cache;
14 static struct kmem_cache *extent_state_cache;
20 struct rb_node rb_node;
23 /* bits for the extent state */
24 #define EXTENT_DIRTY 1
25 #define EXTENT_WRITEBACK (1 << 1)
26 #define EXTENT_UPTODATE (1 << 2)
27 #define EXTENT_LOCKED (1 << 3)
28 #define EXTENT_NEW (1 << 4)
29 #define EXTENT_DELALLOC (1 << 5)
31 #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
33 void __init extent_map_init(void)
35 extent_map_cache = kmem_cache_create("extent_map",
36 sizeof(struct extent_map), 0,
37 SLAB_RECLAIM_ACCOUNT |
40 extent_state_cache = kmem_cache_create("extent_state",
41 sizeof(struct extent_state), 0,
42 SLAB_RECLAIM_ACCOUNT |
47 void __exit extent_map_exit(void)
50 kmem_cache_destroy(extent_map_cache);
51 if (extent_state_cache)
52 kmem_cache_destroy(extent_state_cache);
55 void extent_map_tree_init(struct extent_map_tree *tree,
56 struct address_space *mapping, gfp_t mask)
58 tree->map.rb_node = NULL;
59 tree->state.rb_node = NULL;
60 tree->fill_delalloc = NULL;
61 rwlock_init(&tree->lock);
62 tree->mapping = mapping;
64 EXPORT_SYMBOL(extent_map_tree_init);
66 struct extent_map *alloc_extent_map(gfp_t mask)
68 struct extent_map *em;
69 em = kmem_cache_alloc(extent_map_cache, mask);
70 if (!em || IS_ERR(em))
73 atomic_set(&em->refs, 1);
76 EXPORT_SYMBOL(alloc_extent_map);
78 void free_extent_map(struct extent_map *em)
80 if (atomic_dec_and_test(&em->refs)) {
82 kmem_cache_free(extent_map_cache, em);
85 EXPORT_SYMBOL(free_extent_map);
88 struct extent_state *alloc_extent_state(gfp_t mask)
90 struct extent_state *state;
91 state = kmem_cache_alloc(extent_state_cache, mask);
92 if (!state || IS_ERR(state))
96 atomic_set(&state->refs, 1);
97 init_waitqueue_head(&state->wq);
100 EXPORT_SYMBOL(alloc_extent_state);
102 void free_extent_state(struct extent_state *state)
104 if (atomic_dec_and_test(&state->refs)) {
105 WARN_ON(state->in_tree);
106 kmem_cache_free(extent_state_cache, state);
109 EXPORT_SYMBOL(free_extent_state);
111 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
112 struct rb_node *node)
114 struct rb_node ** p = &root->rb_node;
115 struct rb_node * parent = NULL;
116 struct tree_entry *entry;
120 entry = rb_entry(parent, struct tree_entry, rb_node);
122 if (offset < entry->start)
124 else if (offset > entry->end)
130 entry = rb_entry(node, struct tree_entry, rb_node);
132 rb_link_node(node, parent, p);
133 rb_insert_color(node, root);
137 static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
138 struct rb_node **prev_ret)
140 struct rb_node * n = root->rb_node;
141 struct rb_node *prev = NULL;
142 struct tree_entry *entry;
143 struct tree_entry *prev_entry = NULL;
146 entry = rb_entry(n, struct tree_entry, rb_node);
150 if (offset < entry->start)
152 else if (offset > entry->end)
159 while(prev && offset > prev_entry->end) {
160 prev = rb_next(prev);
161 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
167 static inline struct rb_node *tree_search(struct rb_root *root, u64 offset)
169 struct rb_node *prev;
171 ret = __tree_search(root, offset, &prev);
177 static int tree_delete(struct rb_root *root, u64 offset)
179 struct rb_node *node;
180 struct tree_entry *entry;
182 node = __tree_search(root, offset, NULL);
185 entry = rb_entry(node, struct tree_entry, rb_node);
187 rb_erase(node, root);
192 * add_extent_mapping tries a simple backward merge with existing
193 * mappings. The extent_map struct passed in will be inserted into
194 * the tree directly (no copies made, just a reference taken).
196 int add_extent_mapping(struct extent_map_tree *tree,
197 struct extent_map *em)
200 struct extent_map *prev = NULL;
203 write_lock_irq(&tree->lock);
204 rb = tree_insert(&tree->map, em->end, &em->rb_node);
206 prev = rb_entry(rb, struct extent_map, rb_node);
207 printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev->start, prev->end, em->start, em->end);
211 atomic_inc(&em->refs);
212 if (em->start != 0) {
213 rb = rb_prev(&em->rb_node);
215 prev = rb_entry(rb, struct extent_map, rb_node);
216 if (prev && prev->end + 1 == em->start &&
217 ((em->block_start == 0 && prev->block_start == 0) ||
218 (em->block_start == prev->block_end + 1))) {
219 em->start = prev->start;
220 em->block_start = prev->block_start;
221 rb_erase(&prev->rb_node, &tree->map);
223 free_extent_map(prev);
227 write_unlock_irq(&tree->lock);
230 EXPORT_SYMBOL(add_extent_mapping);
233 * lookup_extent_mapping returns the first extent_map struct in the
234 * tree that intersects the [start, end] (inclusive) range. There may
235 * be additional objects in the tree that intersect, so check the object
236 * returned carefully to make sure you don't need additional lookups.
238 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
241 struct extent_map *em;
242 struct rb_node *rb_node;
244 read_lock_irq(&tree->lock);
245 rb_node = tree_search(&tree->map, start);
250 if (IS_ERR(rb_node)) {
251 em = ERR_PTR(PTR_ERR(rb_node));
254 em = rb_entry(rb_node, struct extent_map, rb_node);
255 if (em->end < start || em->start > end) {
259 atomic_inc(&em->refs);
261 read_unlock_irq(&tree->lock);
264 EXPORT_SYMBOL(lookup_extent_mapping);
267 * removes an extent_map struct from the tree. No reference counts are
268 * dropped, and no checks are done to see if the range is in use
270 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
274 write_lock_irq(&tree->lock);
275 ret = tree_delete(&tree->map, em->end);
276 write_unlock_irq(&tree->lock);
279 EXPORT_SYMBOL(remove_extent_mapping);
282 * utility function to look for merge candidates inside a given range.
283 * Any extents with matching state are merged together into a single
284 * extent in the tree. Extents with EXTENT_IO in their state field
285 * are not merged because the end_io handlers need to be able to do
286 * operations on them without sleeping (or doing allocations/splits).
288 * This should be called with the tree lock held.
290 static int merge_state(struct extent_map_tree *tree,
291 struct extent_state *state)
293 struct extent_state *other;
294 struct rb_node *other_node;
296 if (state->state & EXTENT_IOBITS)
299 other_node = rb_prev(&state->rb_node);
301 other = rb_entry(other_node, struct extent_state, rb_node);
302 if (other->end == state->start - 1 &&
303 other->state == state->state) {
304 state->start = other->start;
306 rb_erase(&other->rb_node, &tree->state);
307 free_extent_state(other);
310 other_node = rb_next(&state->rb_node);
312 other = rb_entry(other_node, struct extent_state, rb_node);
313 if (other->start == state->end + 1 &&
314 other->state == state->state) {
315 other->start = state->start;
317 rb_erase(&state->rb_node, &tree->state);
318 free_extent_state(state);
325 * insert an extent_state struct into the tree. 'bits' are set on the
326 * struct before it is inserted.
328 * This may return -EEXIST if the extent is already there, in which case the
329 * state struct is freed.
331 * The tree lock is not taken internally. This is a utility function and
332 * probably isn't what you want to call (see set/clear_extent_bit).
334 static int insert_state(struct extent_map_tree *tree,
335 struct extent_state *state, u64 start, u64 end,
338 struct rb_node *node;
341 printk("end < start %Lu %Lu\n", end, start);
344 state->state |= bits;
345 state->start = start;
347 if ((end & 4095) == 0) {
348 printk("insert state %Lu %Lu strange end\n", start, end);
351 node = tree_insert(&tree->state, end, &state->rb_node);
353 struct extent_state *found;
354 found = rb_entry(node, struct extent_state, rb_node);
355 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end);
356 free_extent_state(state);
359 merge_state(tree, state);
364 * split a given extent state struct in two, inserting the preallocated
365 * struct 'prealloc' as the newly created second half. 'split' indicates an
366 * offset inside 'orig' where it should be split.
369 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
370 * are two extent state structs in the tree:
371 * prealloc: [orig->start, split - 1]
372 * orig: [ split, orig->end ]
374 * The tree locks are not taken by this function. They need to be held
377 static int split_state(struct extent_map_tree *tree, struct extent_state *orig,
378 struct extent_state *prealloc, u64 split)
380 struct rb_node *node;
381 prealloc->start = orig->start;
382 prealloc->end = split - 1;
383 prealloc->state = orig->state;
385 if ((prealloc->end & 4095) == 0) {
386 printk("insert state %Lu %Lu strange end\n", prealloc->start,
390 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
392 struct extent_state *found;
393 found = rb_entry(node, struct extent_state, rb_node);
394 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end);
395 free_extent_state(prealloc);
402 * utility function to clear some bits in an extent state struct.
403 * it will optionally wake up any one waiting on this state (wake == 1), or
404 * forcibly remove the state from the tree (delete == 1).
406 * If no bits are set on the state struct after clearing things, the
407 * struct is freed and removed from the tree
409 static int clear_state_bit(struct extent_map_tree *tree,
410 struct extent_state *state, int bits, int wake,
413 int ret = state->state & bits;
414 state->state &= ~bits;
417 if (delete || state->state == 0) {
418 if (state->in_tree) {
419 rb_erase(&state->rb_node, &tree->state);
421 free_extent_state(state);
426 merge_state(tree, state);
432 * clear some bits on a range in the tree. This may require splitting
433 * or inserting elements in the tree, so the gfp mask is used to
434 * indicate which allocations or sleeping are allowed.
436 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
437 * the given range from the tree regardless of state (ie for truncate).
439 * the range [start, end] is inclusive.
441 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
442 * bits were already set, or zero if none of the bits were already set.
444 int clear_extent_bit(struct extent_map_tree *tree, u64 start, u64 end,
445 int bits, int wake, int delete, gfp_t mask)
447 struct extent_state *state;
448 struct extent_state *prealloc = NULL;
449 struct rb_node *node;
454 if (!prealloc && (mask & __GFP_WAIT)) {
455 prealloc = alloc_extent_state(mask);
460 write_lock_irq(&tree->lock);
462 * this search will find the extents that end after
465 node = tree_search(&tree->state, start);
468 state = rb_entry(node, struct extent_state, rb_node);
469 if (state->start > end)
471 WARN_ON(state->end < start);
474 * | ---- desired range ---- |
476 * | ------------- state -------------- |
478 * We need to split the extent we found, and may flip
479 * bits on second half.
481 * If the extent we found extends past our range, we
482 * just split and search again. It'll get split again
483 * the next time though.
485 * If the extent we found is inside our range, we clear
486 * the desired bit on it.
489 if (state->start < start) {
490 err = split_state(tree, state, prealloc, start);
491 BUG_ON(err == -EEXIST);
495 if (state->end <= end) {
496 start = state->end + 1;
497 set |= clear_state_bit(tree, state, bits,
500 start = state->start;
505 * | ---- desired range ---- |
507 * We need to split the extent, and clear the bit
510 if (state->start <= end && state->end > end) {
511 err = split_state(tree, state, prealloc, end + 1);
512 BUG_ON(err == -EEXIST);
516 set |= clear_state_bit(tree, prealloc, bits,
522 start = state->end + 1;
523 set |= clear_state_bit(tree, state, bits, wake, delete);
527 write_unlock_irq(&tree->lock);
529 free_extent_state(prealloc);
536 write_unlock_irq(&tree->lock);
537 if (mask & __GFP_WAIT)
541 EXPORT_SYMBOL(clear_extent_bit);
543 static int wait_on_state(struct extent_map_tree *tree,
544 struct extent_state *state)
547 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
548 read_unlock_irq(&tree->lock);
550 read_lock_irq(&tree->lock);
551 finish_wait(&state->wq, &wait);
556 * waits for one or more bits to clear on a range in the state tree.
557 * The range [start, end] is inclusive.
558 * The tree lock is taken by this function
560 int wait_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits)
562 struct extent_state *state;
563 struct rb_node *node;
565 read_lock_irq(&tree->lock);
569 * this search will find all the extents that end after
572 node = tree_search(&tree->state, start);
576 state = rb_entry(node, struct extent_state, rb_node);
578 if (state->start > end)
581 if (state->state & bits) {
582 start = state->start;
583 atomic_inc(&state->refs);
584 wait_on_state(tree, state);
585 free_extent_state(state);
588 start = state->end + 1;
593 if (need_resched()) {
594 read_unlock_irq(&tree->lock);
596 read_lock_irq(&tree->lock);
600 read_unlock_irq(&tree->lock);
603 EXPORT_SYMBOL(wait_extent_bit);
606 * set some bits on a range in the tree. This may require allocations
607 * or sleeping, so the gfp mask is used to indicate what is allowed.
609 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
610 * range already has the desired bits set. The start of the existing
611 * range is returned in failed_start in this case.
613 * [start, end] is inclusive
614 * This takes the tree lock.
616 int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits,
617 int exclusive, u64 *failed_start, gfp_t mask)
619 struct extent_state *state;
620 struct extent_state *prealloc = NULL;
621 struct rb_node *node;
627 if (!prealloc && (mask & __GFP_WAIT)) {
628 prealloc = alloc_extent_state(mask);
633 write_lock_irq(&tree->lock);
635 * this search will find all the extents that end after
638 node = tree_search(&tree->state, start);
640 err = insert_state(tree, prealloc, start, end, bits);
642 BUG_ON(err == -EEXIST);
646 state = rb_entry(node, struct extent_state, rb_node);
647 last_start = state->start;
648 last_end = state->end;
651 * | ---- desired range ---- |
654 * Just lock what we found and keep going
656 if (state->start == start && state->end <= end) {
657 set = state->state & bits;
658 if (set && exclusive) {
659 *failed_start = state->start;
663 state->state |= bits;
664 start = state->end + 1;
665 merge_state(tree, state);
670 * | ---- desired range ---- |
673 * | ------------- state -------------- |
675 * We need to split the extent we found, and may flip bits on
678 * If the extent we found extends past our
679 * range, we just split and search again. It'll get split
680 * again the next time though.
682 * If the extent we found is inside our range, we set the
685 if (state->start < start) {
686 set = state->state & bits;
687 if (exclusive && set) {
688 *failed_start = start;
692 err = split_state(tree, state, prealloc, start);
693 BUG_ON(err == -EEXIST);
697 if (state->end <= end) {
698 state->state |= bits;
699 start = state->end + 1;
700 merge_state(tree, state);
702 start = state->start;
707 * | ---- desired range ---- |
709 * We need to split the extent, and set the bit
712 if (state->start <= end && state->end > end) {
713 set = state->state & bits;
714 if (exclusive && set) {
715 *failed_start = start;
719 err = split_state(tree, state, prealloc, end + 1);
720 BUG_ON(err == -EEXIST);
722 prealloc->state |= bits;
723 merge_state(tree, prealloc);
729 * | ---- desired range ---- |
730 * | state | or | state |
732 * There's a hole, we need to insert something in it and
733 * ignore the extent we found.
735 if (state->start > start) {
737 if (end < last_start)
740 this_end = last_start -1;
741 err = insert_state(tree, prealloc, start, this_end,
744 BUG_ON(err == -EEXIST);
747 start = this_end + 1;
753 write_unlock_irq(&tree->lock);
755 free_extent_state(prealloc);
762 write_unlock_irq(&tree->lock);
763 if (mask & __GFP_WAIT)
767 EXPORT_SYMBOL(set_extent_bit);
769 /* wrappers around set/clear extent bit */
770 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
773 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
776 EXPORT_SYMBOL(set_extent_dirty);
778 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end,
781 return set_extent_bit(tree, start, end,
782 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL,
785 EXPORT_SYMBOL(set_extent_delalloc);
787 int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
790 return clear_extent_bit(tree, start, end,
791 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask);
793 EXPORT_SYMBOL(clear_extent_dirty);
795 int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end,
798 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
801 EXPORT_SYMBOL(set_extent_new);
803 int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end,
806 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask);
808 EXPORT_SYMBOL(clear_extent_new);
810 int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end,
813 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
816 EXPORT_SYMBOL(set_extent_uptodate);
818 int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end,
821 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask);
823 EXPORT_SYMBOL(clear_extent_uptodate);
825 int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end,
828 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK,
831 EXPORT_SYMBOL(set_extent_writeback);
833 int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end,
836 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask);
838 EXPORT_SYMBOL(clear_extent_writeback);
840 int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end)
842 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
844 EXPORT_SYMBOL(wait_on_extent_writeback);
847 * locks a range in ascending order, waiting for any locked regions
848 * it hits on the way. [start,end] are inclusive, and this will sleep.
850 int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask)
855 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
856 &failed_start, mask);
857 if (err == -EEXIST && (mask & __GFP_WAIT)) {
858 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
859 start = failed_start;
863 WARN_ON(start > end);
867 EXPORT_SYMBOL(lock_extent);
869 int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end,
872 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask);
874 EXPORT_SYMBOL(unlock_extent);
877 * helper function to set pages and extents in the tree dirty
879 int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end)
881 unsigned long index = start >> PAGE_CACHE_SHIFT;
882 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
885 while (index <= end_index) {
886 page = find_get_page(tree->mapping, index);
888 __set_page_dirty_nobuffers(page);
889 page_cache_release(page);
892 set_extent_dirty(tree, start, end, GFP_NOFS);
895 EXPORT_SYMBOL(set_range_dirty);
898 * helper function to set both pages and extents in the tree writeback
900 int set_range_writeback(struct extent_map_tree *tree, u64 start, u64 end)
902 unsigned long index = start >> PAGE_CACHE_SHIFT;
903 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
906 while (index <= end_index) {
907 page = find_get_page(tree->mapping, index);
909 set_page_writeback(page);
910 page_cache_release(page);
913 set_extent_writeback(tree, start, end, GFP_NOFS);
916 EXPORT_SYMBOL(set_range_writeback);
918 u64 find_lock_delalloc_range(struct extent_map_tree *tree,
919 u64 start, u64 lock_start, u64 *end, u64 max_bytes)
921 struct rb_node *node;
922 struct extent_state *state;
923 u64 cur_start = start;
927 write_lock_irq(&tree->lock);
929 * this search will find all the extents that end after
933 node = tree_search(&tree->state, cur_start);
934 if (!node || IS_ERR(node)) {
939 state = rb_entry(node, struct extent_state, rb_node);
940 if (state->start != cur_start) {
943 if (!(state->state & EXTENT_DELALLOC)) {
946 if (state->start >= lock_start) {
947 if (state->state & EXTENT_LOCKED) {
949 atomic_inc(&state->refs);
950 write_unlock_irq(&tree->lock);
952 write_lock_irq(&tree->lock);
953 finish_wait(&state->wq, &wait);
954 free_extent_state(state);
957 state->state |= EXTENT_LOCKED;
961 cur_start = state->end + 1;
962 node = rb_next(node);
965 total_bytes = state->end - state->start + 1;
966 if (total_bytes >= max_bytes)
970 write_unlock_irq(&tree->lock);
975 * helper function to lock both pages and extents in the tree.
976 * pages must be locked first.
978 int lock_range(struct extent_map_tree *tree, u64 start, u64 end)
980 unsigned long index = start >> PAGE_CACHE_SHIFT;
981 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
985 while (index <= end_index) {
986 page = grab_cache_page(tree->mapping, index);
997 lock_extent(tree, start, end, GFP_NOFS);
1002 * we failed above in getting the page at 'index', so we undo here
1003 * up to but not including the page at 'index'
1006 index = start >> PAGE_CACHE_SHIFT;
1007 while (index < end_index) {
1008 page = find_get_page(tree->mapping, index);
1010 page_cache_release(page);
1015 EXPORT_SYMBOL(lock_range);
1018 * helper function to unlock both pages and extents in the tree.
1020 int unlock_range(struct extent_map_tree *tree, u64 start, u64 end)
1022 unsigned long index = start >> PAGE_CACHE_SHIFT;
1023 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1026 while (index <= end_index) {
1027 page = find_get_page(tree->mapping, index);
1029 page_cache_release(page);
1032 unlock_extent(tree, start, end, GFP_NOFS);
1035 EXPORT_SYMBOL(unlock_range);
1038 * searches a range in the state tree for a given mask.
1039 * If 'filled' == 1, this returns 1 only if ever extent in the tree
1040 * has the bits set. Otherwise, 1 is returned if any bit in the
1041 * range is found set.
1043 static int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end,
1044 int bits, int filled)
1046 struct extent_state *state = NULL;
1047 struct rb_node *node;
1050 read_lock_irq(&tree->lock);
1051 node = tree_search(&tree->state, start);
1052 while (node && start <= end) {
1053 state = rb_entry(node, struct extent_state, rb_node);
1054 if (state->start > end)
1057 if (filled && state->start > start) {
1061 if (state->state & bits) {
1065 } else if (filled) {
1069 start = state->end + 1;
1072 node = rb_next(node);
1074 read_unlock_irq(&tree->lock);
1079 * helper function to set a given page up to date if all the
1080 * extents in the tree for that page are up to date
1082 static int check_page_uptodate(struct extent_map_tree *tree,
1085 u64 start = page->index << PAGE_CACHE_SHIFT;
1086 u64 end = start + PAGE_CACHE_SIZE - 1;
1087 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
1088 SetPageUptodate(page);
1093 * helper function to unlock a page if all the extents in the tree
1094 * for that page are unlocked
1096 static int check_page_locked(struct extent_map_tree *tree,
1099 u64 start = page->index << PAGE_CACHE_SHIFT;
1100 u64 end = start + PAGE_CACHE_SIZE - 1;
1101 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
1107 * helper function to end page writeback if all the extents
1108 * in the tree for that page are done with writeback
1110 static int check_page_writeback(struct extent_map_tree *tree,
1113 u64 start = page->index << PAGE_CACHE_SHIFT;
1114 u64 end = start + PAGE_CACHE_SIZE - 1;
1115 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0))
1116 end_page_writeback(page);
1120 /* lots and lots of room for performance fixes in the end_bio funcs */
1123 * after a writepage IO is done, we need to:
1124 * clear the uptodate bits on error
1125 * clear the writeback bits in the extent tree for this IO
1126 * end_page_writeback if the page has no more pending IO
1128 * Scheduling is not allowed, so the extent state tree is expected
1129 * to have one and only one object corresponding to this IO.
1131 static int end_bio_extent_writepage(struct bio *bio,
1132 unsigned int bytes_done, int err)
1134 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1135 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1136 struct extent_map_tree *tree = bio->bi_private;
1145 struct page *page = bvec->bv_page;
1146 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1147 end = start + bvec->bv_len - 1;
1149 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1154 if (--bvec >= bio->bi_io_vec)
1155 prefetchw(&bvec->bv_page->flags);
1158 clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
1159 ClearPageUptodate(page);
1162 clear_extent_writeback(tree, start, end, GFP_ATOMIC);
1165 end_page_writeback(page);
1167 check_page_writeback(tree, page);
1168 } while (bvec >= bio->bi_io_vec);
1175 * after a readpage IO is done, we need to:
1176 * clear the uptodate bits on error
1177 * set the uptodate bits if things worked
1178 * set the page up to date if all extents in the tree are uptodate
1179 * clear the lock bit in the extent tree
1180 * unlock the page if there are no other extents locked for it
1182 * Scheduling is not allowed, so the extent state tree is expected
1183 * to have one and only one object corresponding to this IO.
1185 static int end_bio_extent_readpage(struct bio *bio,
1186 unsigned int bytes_done, int err)
1188 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1189 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1190 struct extent_map_tree *tree = bio->bi_private;
1199 struct page *page = bvec->bv_page;
1200 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1201 end = start + bvec->bv_len - 1;
1203 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1208 if (--bvec >= bio->bi_io_vec)
1209 prefetchw(&bvec->bv_page->flags);
1212 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1214 SetPageUptodate(page);
1216 check_page_uptodate(tree, page);
1218 ClearPageUptodate(page);
1222 unlock_extent(tree, start, end, GFP_ATOMIC);
1227 check_page_locked(tree, page);
1228 } while (bvec >= bio->bi_io_vec);
1235 * IO done from prepare_write is pretty simple, we just unlock
1236 * the structs in the extent tree when done, and set the uptodate bits
1239 static int end_bio_extent_preparewrite(struct bio *bio,
1240 unsigned int bytes_done, int err)
1242 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1243 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1244 struct extent_map_tree *tree = bio->bi_private;
1252 struct page *page = bvec->bv_page;
1253 start = (page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1254 end = start + bvec->bv_len - 1;
1256 if (--bvec >= bio->bi_io_vec)
1257 prefetchw(&bvec->bv_page->flags);
1260 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1262 ClearPageUptodate(page);
1266 unlock_extent(tree, start, end, GFP_ATOMIC);
1268 } while (bvec >= bio->bi_io_vec);
1274 static int submit_extent_page(int rw, struct extent_map_tree *tree,
1275 struct page *page, sector_t sector,
1276 size_t size, unsigned long offset,
1277 struct block_device *bdev,
1278 bio_end_io_t end_io_func)
1283 bio = bio_alloc(GFP_NOIO, 1);
1285 bio->bi_sector = sector;
1286 bio->bi_bdev = bdev;
1287 bio->bi_io_vec[0].bv_page = page;
1288 bio->bi_io_vec[0].bv_len = size;
1289 bio->bi_io_vec[0].bv_offset = offset;
1293 bio->bi_size = size;
1295 bio->bi_end_io = end_io_func;
1296 bio->bi_private = tree;
1299 submit_bio(rw, bio);
1301 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1309 * basic readpage implementation. Locked extent state structs are inserted
1310 * into the tree that are removed when the IO is done (by the end_io
1313 int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
1314 get_extent_t *get_extent)
1316 struct inode *inode = page->mapping->host;
1317 u64 start = page->index << PAGE_CACHE_SHIFT;
1318 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1322 u64 last_byte = i_size_read(inode);
1326 struct extent_map *em;
1327 struct block_device *bdev;
1330 size_t page_offset = 0;
1332 size_t blocksize = inode->i_sb->s_blocksize;
1334 if (!PagePrivate(page)) {
1335 SetPagePrivate(page);
1336 set_page_private(page, 1);
1337 WARN_ON(!page->mapping->a_ops->invalidatepage);
1338 page_cache_get(page);
1342 lock_extent(tree, start, end, GFP_NOFS);
1344 while (cur <= end) {
1345 if (cur >= last_byte) {
1346 iosize = PAGE_CACHE_SIZE - page_offset;
1347 zero_user_page(page, page_offset, iosize, KM_USER0);
1348 set_extent_uptodate(tree, cur, cur + iosize - 1,
1350 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1353 em = get_extent(inode, page, page_offset, cur, end, 0);
1354 if (IS_ERR(em) || !em) {
1356 unlock_extent(tree, cur, end, GFP_NOFS);
1360 extent_offset = cur - em->start;
1361 BUG_ON(em->end < cur);
1364 iosize = min(em->end - cur, end - cur) + 1;
1365 cur_end = min(em->end, end);
1366 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
1367 sector = (em->block_start + extent_offset) >> 9;
1369 block_start = em->block_start;
1370 free_extent_map(em);
1373 /* we've found a hole, just zero and go on */
1374 if (block_start == 0) {
1375 zero_user_page(page, page_offset, iosize, KM_USER0);
1376 set_extent_uptodate(tree, cur, cur + iosize - 1,
1378 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1380 page_offset += iosize;
1383 /* the get_extent function already copied into the page */
1384 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
1385 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1387 page_offset += iosize;
1391 ret = submit_extent_page(READ, tree, page,
1392 sector, iosize, page_offset, bdev,
1393 end_bio_extent_readpage);
1397 page_offset += iosize;
1401 if (!PageError(page))
1402 SetPageUptodate(page);
1407 EXPORT_SYMBOL(extent_read_full_page);
1410 * the writepage semantics are similar to regular writepage. extent
1411 * records are inserted to lock ranges in the tree, and as dirty areas
1412 * are found, they are marked writeback. Then the lock bits are removed
1413 * and the end_io handler clears the writeback ranges
1415 int extent_write_full_page(struct extent_map_tree *tree, struct page *page,
1416 get_extent_t *get_extent,
1417 struct writeback_control *wbc)
1419 struct inode *inode = page->mapping->host;
1420 u64 start = page->index << PAGE_CACHE_SHIFT;
1421 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1425 u64 last_byte = i_size_read(inode);
1428 struct extent_map *em;
1429 struct block_device *bdev;
1432 size_t page_offset = 0;
1435 loff_t i_size = i_size_read(inode);
1436 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
1440 WARN_ON(!PageLocked(page));
1441 if (page->index > end_index) {
1442 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
1447 if (page->index == end_index) {
1448 size_t offset = i_size & (PAGE_CACHE_SIZE - 1);
1449 zero_user_page(page, offset,
1450 PAGE_CACHE_SIZE - offset, KM_USER0);
1453 if (!PagePrivate(page)) {
1454 SetPagePrivate(page);
1455 set_page_private(page, 1);
1456 WARN_ON(!page->mapping->a_ops->invalidatepage);
1457 page_cache_get(page);
1460 lock_extent(tree, start, page_end, GFP_NOFS);
1461 nr_delalloc = find_lock_delalloc_range(tree, start, page_end + 1,
1465 tree->fill_delalloc(inode, start, delalloc_end);
1466 if (delalloc_end >= page_end + 1) {
1467 clear_extent_bit(tree, page_end + 1, delalloc_end,
1468 EXTENT_LOCKED | EXTENT_DELALLOC,
1471 clear_extent_bit(tree, start, page_end, EXTENT_DELALLOC,
1473 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
1474 printk("found delalloc bits after clear extent_bit\n");
1476 } else if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
1477 printk("found delalloc bits after find_delalloc_range returns 0\n");
1481 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
1482 printk("found delalloc bits after lock_extent\n");
1485 if (last_byte <= start) {
1486 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
1490 set_extent_uptodate(tree, start, page_end, GFP_NOFS);
1491 blocksize = inode->i_sb->s_blocksize;
1493 while (cur <= end) {
1494 if (cur >= last_byte) {
1495 clear_extent_dirty(tree, cur, page_end, GFP_NOFS);
1498 em = get_extent(inode, page, page_offset, cur, end, 0);
1499 if (IS_ERR(em) || !em) {
1504 extent_offset = cur - em->start;
1505 BUG_ON(em->end < cur);
1507 iosize = min(em->end - cur, end - cur) + 1;
1508 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
1509 sector = (em->block_start + extent_offset) >> 9;
1511 block_start = em->block_start;
1512 free_extent_map(em);
1515 if (block_start == 0 || block_start == EXTENT_MAP_INLINE) {
1516 clear_extent_dirty(tree, cur,
1517 cur + iosize - 1, GFP_NOFS);
1519 page_offset += iosize;
1523 /* leave this out until we have a page_mkwrite call */
1524 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
1527 page_offset += iosize;
1530 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
1531 set_range_writeback(tree, cur, cur + iosize - 1);
1532 ret = submit_extent_page(WRITE, tree, page,
1533 sector, iosize, page_offset, bdev,
1534 end_bio_extent_writepage);
1538 page_offset += iosize;
1542 WARN_ON(test_range_bit(tree, start, page_end, EXTENT_DIRTY, 0));
1543 unlock_extent(tree, start, page_end, GFP_NOFS);
1547 EXPORT_SYMBOL(extent_write_full_page);
1550 * basic invalidatepage code, this waits on any locked or writeback
1551 * ranges corresponding to the page, and then deletes any extent state
1552 * records from the tree
1554 int extent_invalidatepage(struct extent_map_tree *tree,
1555 struct page *page, unsigned long offset)
1557 u64 start = (page->index << PAGE_CACHE_SHIFT);
1558 u64 end = start + PAGE_CACHE_SIZE - 1;
1559 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
1561 start += (offset + blocksize -1) & ~(blocksize - 1);
1565 lock_extent(tree, start, end, GFP_NOFS);
1566 wait_on_extent_writeback(tree, start, end);
1567 clear_extent_bit(tree, start, end, EXTENT_LOCKED | EXTENT_DIRTY,
1571 EXPORT_SYMBOL(extent_invalidatepage);
1574 * simple commit_write call, set_range_dirty is used to mark both
1575 * the pages and the extent records as dirty
1577 int extent_commit_write(struct extent_map_tree *tree,
1578 struct inode *inode, struct page *page,
1579 unsigned from, unsigned to)
1581 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1583 if (!PagePrivate(page)) {
1584 SetPagePrivate(page);
1585 set_page_private(page, 1);
1586 WARN_ON(!page->mapping->a_ops->invalidatepage);
1587 page_cache_get(page);
1590 set_page_dirty(page);
1592 if (pos > inode->i_size) {
1593 i_size_write(inode, pos);
1594 mark_inode_dirty(inode);
1598 EXPORT_SYMBOL(extent_commit_write);
1600 int extent_prepare_write(struct extent_map_tree *tree,
1601 struct inode *inode, struct page *page,
1602 unsigned from, unsigned to, get_extent_t *get_extent)
1604 u64 page_start = page->index << PAGE_CACHE_SHIFT;
1605 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
1607 u64 orig_block_start;
1610 struct extent_map *em;
1611 unsigned blocksize = 1 << inode->i_blkbits;
1612 size_t page_offset = 0;
1613 size_t block_off_start;
1614 size_t block_off_end;
1620 if (!PagePrivate(page)) {
1621 SetPagePrivate(page);
1622 set_page_private(page, 1);
1623 WARN_ON(!page->mapping->a_ops->invalidatepage);
1624 page_cache_get(page);
1626 block_start = (page_start + from) & ~((u64)blocksize - 1);
1627 block_end = (page_start + to - 1) | (blocksize - 1);
1628 orig_block_start = block_start;
1630 lock_extent(tree, page_start, page_end, GFP_NOFS);
1631 while(block_start <= block_end) {
1632 em = get_extent(inode, page, page_offset, block_start,
1634 if (IS_ERR(em) || !em) {
1637 cur_end = min(block_end, em->end);
1638 block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
1639 block_off_end = block_off_start + blocksize;
1640 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
1642 if (!PageUptodate(page) && isnew &&
1643 (block_off_end > to || block_off_start < from)) {
1646 kaddr = kmap_atomic(page, KM_USER0);
1647 if (block_off_end > to)
1648 memset(kaddr + to, 0, block_off_end - to);
1649 if (block_off_start < from)
1650 memset(kaddr + block_off_start, 0,
1651 from - block_off_start);
1652 flush_dcache_page(page);
1653 kunmap_atomic(kaddr, KM_USER0);
1655 if (!isnew && !PageUptodate(page) &&
1656 (block_off_end > to || block_off_start < from) &&
1657 !test_range_bit(tree, block_start, cur_end,
1658 EXTENT_UPTODATE, 1)) {
1660 u64 extent_offset = block_start - em->start;
1662 sector = (em->block_start + extent_offset) >> 9;
1663 iosize = (cur_end - block_start + blocksize - 1) &
1664 ~((u64)blocksize - 1);
1666 * we've already got the extent locked, but we
1667 * need to split the state such that our end_bio
1668 * handler can clear the lock.
1670 set_extent_bit(tree, block_start,
1671 block_start + iosize - 1,
1672 EXTENT_LOCKED, 0, NULL, GFP_NOFS);
1673 ret = submit_extent_page(READ, tree, page,
1674 sector, iosize, page_offset, em->bdev,
1675 end_bio_extent_preparewrite);
1677 block_start = block_start + iosize;
1679 set_extent_uptodate(tree, block_start, cur_end,
1681 unlock_extent(tree, block_start, cur_end, GFP_NOFS);
1682 block_start = cur_end + 1;
1684 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
1685 free_extent_map(em);
1688 wait_extent_bit(tree, orig_block_start,
1689 block_end, EXTENT_LOCKED);
1691 check_page_uptodate(tree, page);
1693 /* FIXME, zero out newly allocated blocks on error */
1696 EXPORT_SYMBOL(extent_prepare_write);
1699 * a helper for releasepage. As long as there are no locked extents
1700 * in the range corresponding to the page, both state records and extent
1701 * map records are removed
1703 int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page)
1705 struct extent_map *em;
1706 u64 start = page->index << PAGE_CACHE_SHIFT;
1707 u64 end = start + PAGE_CACHE_SIZE - 1;
1708 u64 orig_start = start;
1711 while (start <= end) {
1712 em = lookup_extent_mapping(tree, start, end);
1713 if (!em || IS_ERR(em))
1715 if (!test_range_bit(tree, em->start, em->end,
1716 EXTENT_LOCKED, 0)) {
1717 remove_extent_mapping(tree, em);
1718 /* once for the rb tree */
1719 free_extent_map(em);
1721 start = em->end + 1;
1723 free_extent_map(em);
1725 if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0))
1728 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE,
1732 EXPORT_SYMBOL(try_release_extent_mapping);