1 #include <linux/bitops.h>
2 #include <linux/slab.h>
6 #include <linux/pagemap.h>
7 #include <linux/page-flags.h>
8 #include <linux/module.h>
9 #include <linux/spinlock.h>
10 #include <linux/blkdev.h>
11 #include <linux/swap.h>
12 #include <linux/version.h>
13 #include <linux/writeback.h>
14 #include <linux/pagevec.h>
15 #include "extent_io.h"
16 #include "extent_map.h"
18 /* temporary define until extent_map moves out of btrfs */
19 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
20 unsigned long extra_flags,
21 void (*ctor)(void *, struct kmem_cache *,
24 static struct kmem_cache *extent_state_cache;
25 static struct kmem_cache *extent_buffer_cache;
27 static LIST_HEAD(buffers);
28 static LIST_HEAD(states);
30 #define BUFFER_LRU_MAX 64
35 struct rb_node rb_node;
38 struct extent_page_data {
40 struct extent_io_tree *tree;
41 get_extent_t *get_extent;
44 int __init extent_io_init(void)
46 extent_state_cache = btrfs_cache_create("extent_state",
47 sizeof(struct extent_state), 0,
49 if (!extent_state_cache)
52 extent_buffer_cache = btrfs_cache_create("extent_buffers",
53 sizeof(struct extent_buffer), 0,
55 if (!extent_buffer_cache)
56 goto free_state_cache;
60 kmem_cache_destroy(extent_state_cache);
64 void extent_io_exit(void)
66 struct extent_state *state;
68 while (!list_empty(&states)) {
69 state = list_entry(states.next, struct extent_state, list);
70 printk("state leak: start %Lu end %Lu state %lu in tree %p refs %d\n", state->start, state->end, state->state, state->tree, atomic_read(&state->refs));
71 list_del(&state->list);
72 kmem_cache_free(extent_state_cache, state);
76 if (extent_state_cache)
77 kmem_cache_destroy(extent_state_cache);
78 if (extent_buffer_cache)
79 kmem_cache_destroy(extent_buffer_cache);
82 void extent_io_tree_init(struct extent_io_tree *tree,
83 struct address_space *mapping, gfp_t mask)
85 tree->state.rb_node = NULL;
87 tree->dirty_bytes = 0;
88 spin_lock_init(&tree->lock);
89 spin_lock_init(&tree->lru_lock);
90 tree->mapping = mapping;
91 INIT_LIST_HEAD(&tree->buffer_lru);
94 EXPORT_SYMBOL(extent_io_tree_init);
96 void extent_io_tree_empty_lru(struct extent_io_tree *tree)
98 struct extent_buffer *eb;
99 while(!list_empty(&tree->buffer_lru)) {
100 eb = list_entry(tree->buffer_lru.next, struct extent_buffer,
102 list_del_init(&eb->lru);
103 free_extent_buffer(eb);
106 EXPORT_SYMBOL(extent_io_tree_empty_lru);
108 struct extent_state *alloc_extent_state(gfp_t mask)
110 struct extent_state *state;
112 state = kmem_cache_alloc(extent_state_cache, mask);
113 if (!state || IS_ERR(state))
119 atomic_set(&state->refs, 1);
120 init_waitqueue_head(&state->wq);
123 EXPORT_SYMBOL(alloc_extent_state);
125 void free_extent_state(struct extent_state *state)
129 if (atomic_dec_and_test(&state->refs)) {
130 WARN_ON(state->tree);
131 kmem_cache_free(extent_state_cache, state);
134 EXPORT_SYMBOL(free_extent_state);
136 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
137 struct rb_node *node)
139 struct rb_node ** p = &root->rb_node;
140 struct rb_node * parent = NULL;
141 struct tree_entry *entry;
145 entry = rb_entry(parent, struct tree_entry, rb_node);
147 if (offset < entry->start)
149 else if (offset > entry->end)
155 entry = rb_entry(node, struct tree_entry, rb_node);
156 rb_link_node(node, parent, p);
157 rb_insert_color(node, root);
161 static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
162 struct rb_node **prev_ret,
163 struct rb_node **next_ret)
165 struct rb_node * n = root->rb_node;
166 struct rb_node *prev = NULL;
167 struct rb_node *orig_prev = NULL;
168 struct tree_entry *entry;
169 struct tree_entry *prev_entry = NULL;
172 entry = rb_entry(n, struct tree_entry, rb_node);
176 if (offset < entry->start)
178 else if (offset > entry->end)
186 while(prev && offset > prev_entry->end) {
187 prev = rb_next(prev);
188 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
195 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
196 while(prev && offset < prev_entry->start) {
197 prev = rb_prev(prev);
198 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
205 static inline struct rb_node *tree_search(struct rb_root *root, u64 offset)
207 struct rb_node *prev = NULL;
210 ret = __tree_search(root, offset, &prev, NULL);
217 * utility function to look for merge candidates inside a given range.
218 * Any extents with matching state are merged together into a single
219 * extent in the tree. Extents with EXTENT_IO in their state field
220 * are not merged because the end_io handlers need to be able to do
221 * operations on them without sleeping (or doing allocations/splits).
223 * This should be called with the tree lock held.
225 static int merge_state(struct extent_io_tree *tree,
226 struct extent_state *state)
228 struct extent_state *other;
229 struct rb_node *other_node;
231 if (state->state & EXTENT_IOBITS)
234 other_node = rb_prev(&state->rb_node);
236 other = rb_entry(other_node, struct extent_state, rb_node);
237 if (other->end == state->start - 1 &&
238 other->state == state->state) {
239 state->start = other->start;
241 rb_erase(&other->rb_node, &tree->state);
242 free_extent_state(other);
245 other_node = rb_next(&state->rb_node);
247 other = rb_entry(other_node, struct extent_state, rb_node);
248 if (other->start == state->end + 1 &&
249 other->state == state->state) {
250 other->start = state->start;
252 rb_erase(&state->rb_node, &tree->state);
253 free_extent_state(state);
260 * insert an extent_state struct into the tree. 'bits' are set on the
261 * struct before it is inserted.
263 * This may return -EEXIST if the extent is already there, in which case the
264 * state struct is freed.
266 * The tree lock is not taken internally. This is a utility function and
267 * probably isn't what you want to call (see set/clear_extent_bit).
269 static int insert_state(struct extent_io_tree *tree,
270 struct extent_state *state, u64 start, u64 end,
273 struct rb_node *node;
276 printk("end < start %Lu %Lu\n", end, start);
279 if (bits & EXTENT_DIRTY)
280 tree->dirty_bytes += end - start + 1;
281 state->state |= bits;
282 state->start = start;
284 node = tree_insert(&tree->state, end, &state->rb_node);
286 struct extent_state *found;
287 found = rb_entry(node, struct extent_state, rb_node);
288 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end);
289 free_extent_state(state);
293 merge_state(tree, state);
298 * split a given extent state struct in two, inserting the preallocated
299 * struct 'prealloc' as the newly created second half. 'split' indicates an
300 * offset inside 'orig' where it should be split.
303 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
304 * are two extent state structs in the tree:
305 * prealloc: [orig->start, split - 1]
306 * orig: [ split, orig->end ]
308 * The tree locks are not taken by this function. They need to be held
311 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
312 struct extent_state *prealloc, u64 split)
314 struct rb_node *node;
315 prealloc->start = orig->start;
316 prealloc->end = split - 1;
317 prealloc->state = orig->state;
320 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
322 struct extent_state *found;
323 found = rb_entry(node, struct extent_state, rb_node);
324 printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end);
325 free_extent_state(prealloc);
328 prealloc->tree = tree;
333 * utility function to clear some bits in an extent state struct.
334 * it will optionally wake up any one waiting on this state (wake == 1), or
335 * forcibly remove the state from the tree (delete == 1).
337 * If no bits are set on the state struct after clearing things, the
338 * struct is freed and removed from the tree
340 static int clear_state_bit(struct extent_io_tree *tree,
341 struct extent_state *state, int bits, int wake,
344 int ret = state->state & bits;
346 if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
347 u64 range = state->end - state->start + 1;
348 WARN_ON(range > tree->dirty_bytes);
349 tree->dirty_bytes -= range;
351 state->state &= ~bits;
354 if (delete || state->state == 0) {
356 rb_erase(&state->rb_node, &tree->state);
358 free_extent_state(state);
363 merge_state(tree, state);
369 * clear some bits on a range in the tree. This may require splitting
370 * or inserting elements in the tree, so the gfp mask is used to
371 * indicate which allocations or sleeping are allowed.
373 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
374 * the given range from the tree regardless of state (ie for truncate).
376 * the range [start, end] is inclusive.
378 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
379 * bits were already set, or zero if none of the bits were already set.
381 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
382 int bits, int wake, int delete, gfp_t mask)
384 struct extent_state *state;
385 struct extent_state *prealloc = NULL;
386 struct rb_node *node;
392 if (!prealloc && (mask & __GFP_WAIT)) {
393 prealloc = alloc_extent_state(mask);
398 spin_lock_irqsave(&tree->lock, flags);
400 * this search will find the extents that end after
403 node = tree_search(&tree->state, start);
406 state = rb_entry(node, struct extent_state, rb_node);
407 if (state->start > end)
409 WARN_ON(state->end < start);
412 * | ---- desired range ---- |
414 * | ------------- state -------------- |
416 * We need to split the extent we found, and may flip
417 * bits on second half.
419 * If the extent we found extends past our range, we
420 * just split and search again. It'll get split again
421 * the next time though.
423 * If the extent we found is inside our range, we clear
424 * the desired bit on it.
427 if (state->start < start) {
429 prealloc = alloc_extent_state(GFP_ATOMIC);
430 err = split_state(tree, state, prealloc, start);
431 BUG_ON(err == -EEXIST);
435 if (state->end <= end) {
436 start = state->end + 1;
437 set |= clear_state_bit(tree, state, bits,
440 start = state->start;
445 * | ---- desired range ---- |
447 * We need to split the extent, and clear the bit
450 if (state->start <= end && state->end > end) {
452 prealloc = alloc_extent_state(GFP_ATOMIC);
453 err = split_state(tree, state, prealloc, end + 1);
454 BUG_ON(err == -EEXIST);
458 set |= clear_state_bit(tree, prealloc, bits,
464 start = state->end + 1;
465 set |= clear_state_bit(tree, state, bits, wake, delete);
469 spin_unlock_irqrestore(&tree->lock, flags);
471 free_extent_state(prealloc);
478 spin_unlock_irqrestore(&tree->lock, flags);
479 if (mask & __GFP_WAIT)
483 EXPORT_SYMBOL(clear_extent_bit);
485 static int wait_on_state(struct extent_io_tree *tree,
486 struct extent_state *state)
489 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
490 spin_unlock_irq(&tree->lock);
492 spin_lock_irq(&tree->lock);
493 finish_wait(&state->wq, &wait);
498 * waits for one or more bits to clear on a range in the state tree.
499 * The range [start, end] is inclusive.
500 * The tree lock is taken by this function
502 int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
504 struct extent_state *state;
505 struct rb_node *node;
507 spin_lock_irq(&tree->lock);
511 * this search will find all the extents that end after
514 node = tree_search(&tree->state, start);
518 state = rb_entry(node, struct extent_state, rb_node);
520 if (state->start > end)
523 if (state->state & bits) {
524 start = state->start;
525 atomic_inc(&state->refs);
526 wait_on_state(tree, state);
527 free_extent_state(state);
530 start = state->end + 1;
535 if (need_resched()) {
536 spin_unlock_irq(&tree->lock);
538 spin_lock_irq(&tree->lock);
542 spin_unlock_irq(&tree->lock);
545 EXPORT_SYMBOL(wait_extent_bit);
547 static void set_state_bits(struct extent_io_tree *tree,
548 struct extent_state *state,
551 if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
552 u64 range = state->end - state->start + 1;
553 tree->dirty_bytes += range;
555 state->state |= bits;
559 * set some bits on a range in the tree. This may require allocations
560 * or sleeping, so the gfp mask is used to indicate what is allowed.
562 * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
563 * range already has the desired bits set. The start of the existing
564 * range is returned in failed_start in this case.
566 * [start, end] is inclusive
567 * This takes the tree lock.
569 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits,
570 int exclusive, u64 *failed_start, gfp_t mask)
572 struct extent_state *state;
573 struct extent_state *prealloc = NULL;
574 struct rb_node *node;
581 if (!prealloc && (mask & __GFP_WAIT)) {
582 prealloc = alloc_extent_state(mask);
587 spin_lock_irqsave(&tree->lock, flags);
589 * this search will find all the extents that end after
592 node = tree_search(&tree->state, start);
594 err = insert_state(tree, prealloc, start, end, bits);
596 BUG_ON(err == -EEXIST);
600 state = rb_entry(node, struct extent_state, rb_node);
601 last_start = state->start;
602 last_end = state->end;
605 * | ---- desired range ---- |
608 * Just lock what we found and keep going
610 if (state->start == start && state->end <= end) {
611 set = state->state & bits;
612 if (set && exclusive) {
613 *failed_start = state->start;
617 set_state_bits(tree, state, bits);
618 start = state->end + 1;
619 merge_state(tree, state);
624 * | ---- desired range ---- |
627 * | ------------- state -------------- |
629 * We need to split the extent we found, and may flip bits on
632 * If the extent we found extends past our
633 * range, we just split and search again. It'll get split
634 * again the next time though.
636 * If the extent we found is inside our range, we set the
639 if (state->start < start) {
640 set = state->state & bits;
641 if (exclusive && set) {
642 *failed_start = start;
646 err = split_state(tree, state, prealloc, start);
647 BUG_ON(err == -EEXIST);
651 if (state->end <= end) {
652 set_state_bits(tree, state, bits);
653 start = state->end + 1;
654 merge_state(tree, state);
656 start = state->start;
661 * | ---- desired range ---- |
662 * | state | or | state |
664 * There's a hole, we need to insert something in it and
665 * ignore the extent we found.
667 if (state->start > start) {
669 if (end < last_start)
672 this_end = last_start -1;
673 err = insert_state(tree, prealloc, start, this_end,
676 BUG_ON(err == -EEXIST);
679 start = this_end + 1;
683 * | ---- desired range ---- |
685 * We need to split the extent, and set the bit
688 if (state->start <= end && state->end > end) {
689 set = state->state & bits;
690 if (exclusive && set) {
691 *failed_start = start;
695 err = split_state(tree, state, prealloc, end + 1);
696 BUG_ON(err == -EEXIST);
698 set_state_bits(tree, prealloc, bits);
699 merge_state(tree, prealloc);
707 spin_unlock_irqrestore(&tree->lock, flags);
709 free_extent_state(prealloc);
716 spin_unlock_irqrestore(&tree->lock, flags);
717 if (mask & __GFP_WAIT)
721 EXPORT_SYMBOL(set_extent_bit);
723 /* wrappers around set/clear extent bit */
724 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
727 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
730 EXPORT_SYMBOL(set_extent_dirty);
732 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
733 int bits, gfp_t mask)
735 return set_extent_bit(tree, start, end, bits, 0, NULL,
738 EXPORT_SYMBOL(set_extent_bits);
740 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
741 int bits, gfp_t mask)
743 return clear_extent_bit(tree, start, end, bits, 0, 0, mask);
745 EXPORT_SYMBOL(clear_extent_bits);
747 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
750 return set_extent_bit(tree, start, end,
751 EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL,
754 EXPORT_SYMBOL(set_extent_delalloc);
756 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
759 return clear_extent_bit(tree, start, end,
760 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask);
762 EXPORT_SYMBOL(clear_extent_dirty);
764 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
767 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
770 EXPORT_SYMBOL(set_extent_new);
772 int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
775 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask);
777 EXPORT_SYMBOL(clear_extent_new);
779 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
782 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
785 EXPORT_SYMBOL(set_extent_uptodate);
787 int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
790 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask);
792 EXPORT_SYMBOL(clear_extent_uptodate);
794 int set_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
797 return set_extent_bit(tree, start, end, EXTENT_WRITEBACK,
800 EXPORT_SYMBOL(set_extent_writeback);
802 int clear_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
805 return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask);
807 EXPORT_SYMBOL(clear_extent_writeback);
809 int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
811 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
813 EXPORT_SYMBOL(wait_on_extent_writeback);
815 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
820 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
821 &failed_start, mask);
822 if (err == -EEXIST && (mask & __GFP_WAIT)) {
823 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
824 start = failed_start;
828 WARN_ON(start > end);
832 EXPORT_SYMBOL(lock_extent);
834 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
837 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask);
839 EXPORT_SYMBOL(unlock_extent);
842 * helper function to set pages and extents in the tree dirty
844 int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
846 unsigned long index = start >> PAGE_CACHE_SHIFT;
847 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
850 while (index <= end_index) {
851 page = find_get_page(tree->mapping, index);
853 __set_page_dirty_nobuffers(page);
854 page_cache_release(page);
857 set_extent_dirty(tree, start, end, GFP_NOFS);
860 EXPORT_SYMBOL(set_range_dirty);
863 * helper function to set both pages and extents in the tree writeback
865 int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
867 unsigned long index = start >> PAGE_CACHE_SHIFT;
868 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
871 while (index <= end_index) {
872 page = find_get_page(tree->mapping, index);
874 set_page_writeback(page);
875 page_cache_release(page);
878 set_extent_writeback(tree, start, end, GFP_NOFS);
881 EXPORT_SYMBOL(set_range_writeback);
883 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
884 u64 *start_ret, u64 *end_ret, int bits)
886 struct rb_node *node;
887 struct extent_state *state;
890 spin_lock_irq(&tree->lock);
892 * this search will find all the extents that end after
895 node = tree_search(&tree->state, start);
896 if (!node || IS_ERR(node)) {
901 state = rb_entry(node, struct extent_state, rb_node);
902 if (state->end >= start && (state->state & bits)) {
903 *start_ret = state->start;
904 *end_ret = state->end;
908 node = rb_next(node);
913 spin_unlock_irq(&tree->lock);
916 EXPORT_SYMBOL(find_first_extent_bit);
918 u64 find_lock_delalloc_range(struct extent_io_tree *tree,
919 u64 *start, u64 *end, u64 max_bytes)
921 struct rb_node *node;
922 struct extent_state *state;
923 u64 cur_start = *start;
927 spin_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)) {
940 state = rb_entry(node, struct extent_state, rb_node);
941 if (found && state->start != cur_start) {
944 if (!(state->state & EXTENT_DELALLOC)) {
950 struct extent_state *prev_state;
951 struct rb_node *prev_node = node;
953 prev_node = rb_prev(prev_node);
956 prev_state = rb_entry(prev_node,
959 if (!(prev_state->state & EXTENT_DELALLOC))
965 if (state->state & EXTENT_LOCKED) {
967 atomic_inc(&state->refs);
968 prepare_to_wait(&state->wq, &wait,
969 TASK_UNINTERRUPTIBLE);
970 spin_unlock_irq(&tree->lock);
972 spin_lock_irq(&tree->lock);
973 finish_wait(&state->wq, &wait);
974 free_extent_state(state);
977 state->state |= EXTENT_LOCKED;
979 *start = state->start;
982 cur_start = state->end + 1;
983 node = rb_next(node);
986 total_bytes += state->end - state->start + 1;
987 if (total_bytes >= max_bytes)
991 spin_unlock_irq(&tree->lock);
995 u64 count_range_bits(struct extent_io_tree *tree,
996 u64 *start, u64 search_end, u64 max_bytes,
999 struct rb_node *node;
1000 struct extent_state *state;
1001 u64 cur_start = *start;
1002 u64 total_bytes = 0;
1005 if (search_end <= cur_start) {
1006 printk("search_end %Lu start %Lu\n", search_end, cur_start);
1011 spin_lock_irq(&tree->lock);
1012 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1013 total_bytes = tree->dirty_bytes;
1017 * this search will find all the extents that end after
1020 node = tree_search(&tree->state, cur_start);
1021 if (!node || IS_ERR(node)) {
1026 state = rb_entry(node, struct extent_state, rb_node);
1027 if (state->start > search_end)
1029 if (state->end >= cur_start && (state->state & bits)) {
1030 total_bytes += min(search_end, state->end) + 1 -
1031 max(cur_start, state->start);
1032 if (total_bytes >= max_bytes)
1035 *start = state->start;
1039 node = rb_next(node);
1044 spin_unlock_irq(&tree->lock);
1048 * helper function to lock both pages and extents in the tree.
1049 * pages must be locked first.
1051 int lock_range(struct extent_io_tree *tree, u64 start, u64 end)
1053 unsigned long index = start >> PAGE_CACHE_SHIFT;
1054 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1058 while (index <= end_index) {
1059 page = grab_cache_page(tree->mapping, index);
1065 err = PTR_ERR(page);
1070 lock_extent(tree, start, end, GFP_NOFS);
1075 * we failed above in getting the page at 'index', so we undo here
1076 * up to but not including the page at 'index'
1079 index = start >> PAGE_CACHE_SHIFT;
1080 while (index < end_index) {
1081 page = find_get_page(tree->mapping, index);
1083 page_cache_release(page);
1088 EXPORT_SYMBOL(lock_range);
1091 * helper function to unlock both pages and extents in the tree.
1093 int unlock_range(struct extent_io_tree *tree, u64 start, u64 end)
1095 unsigned long index = start >> PAGE_CACHE_SHIFT;
1096 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1099 while (index <= end_index) {
1100 page = find_get_page(tree->mapping, index);
1102 page_cache_release(page);
1105 unlock_extent(tree, start, end, GFP_NOFS);
1108 EXPORT_SYMBOL(unlock_range);
1110 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1112 struct rb_node *node;
1113 struct extent_state *state;
1116 spin_lock_irq(&tree->lock);
1118 * this search will find all the extents that end after
1121 node = tree_search(&tree->state, start);
1122 if (!node || IS_ERR(node)) {
1126 state = rb_entry(node, struct extent_state, rb_node);
1127 if (state->start != start) {
1131 state->private = private;
1133 spin_unlock_irq(&tree->lock);
1137 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1139 struct rb_node *node;
1140 struct extent_state *state;
1143 spin_lock_irq(&tree->lock);
1145 * this search will find all the extents that end after
1148 node = tree_search(&tree->state, start);
1149 if (!node || IS_ERR(node)) {
1153 state = rb_entry(node, struct extent_state, rb_node);
1154 if (state->start != start) {
1158 *private = state->private;
1160 spin_unlock_irq(&tree->lock);
1165 * searches a range in the state tree for a given mask.
1166 * If 'filled' == 1, this returns 1 only if every extent in the tree
1167 * has the bits set. Otherwise, 1 is returned if any bit in the
1168 * range is found set.
1170 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1171 int bits, int filled)
1173 struct extent_state *state = NULL;
1174 struct rb_node *node;
1176 unsigned long flags;
1178 spin_lock_irqsave(&tree->lock, flags);
1179 node = tree_search(&tree->state, start);
1180 while (node && start <= end) {
1181 state = rb_entry(node, struct extent_state, rb_node);
1183 if (filled && state->start > start) {
1188 if (state->start > end)
1191 if (state->state & bits) {
1195 } else if (filled) {
1199 start = state->end + 1;
1202 node = rb_next(node);
1209 spin_unlock_irqrestore(&tree->lock, flags);
1212 EXPORT_SYMBOL(test_range_bit);
1215 * helper function to set a given page up to date if all the
1216 * extents in the tree for that page are up to date
1218 static int check_page_uptodate(struct extent_io_tree *tree,
1221 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1222 u64 end = start + PAGE_CACHE_SIZE - 1;
1223 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
1224 SetPageUptodate(page);
1229 * helper function to unlock a page if all the extents in the tree
1230 * for that page are unlocked
1232 static int check_page_locked(struct extent_io_tree *tree,
1235 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1236 u64 end = start + PAGE_CACHE_SIZE - 1;
1237 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
1243 * helper function to end page writeback if all the extents
1244 * in the tree for that page are done with writeback
1246 static int check_page_writeback(struct extent_io_tree *tree,
1249 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1250 u64 end = start + PAGE_CACHE_SIZE - 1;
1251 if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0))
1252 end_page_writeback(page);
1256 /* lots and lots of room for performance fixes in the end_bio funcs */
1259 * after a writepage IO is done, we need to:
1260 * clear the uptodate bits on error
1261 * clear the writeback bits in the extent tree for this IO
1262 * end_page_writeback if the page has no more pending IO
1264 * Scheduling is not allowed, so the extent state tree is expected
1265 * to have one and only one object corresponding to this IO.
1267 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1268 static void end_bio_extent_writepage(struct bio *bio, int err)
1270 static int end_bio_extent_writepage(struct bio *bio,
1271 unsigned int bytes_done, int err)
1274 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1275 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1276 struct extent_state *state = bio->bi_private;
1277 struct extent_io_tree *tree = state->tree;
1278 struct rb_node *node;
1283 unsigned long flags;
1285 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1290 struct page *page = bvec->bv_page;
1291 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1293 end = start + bvec->bv_len - 1;
1295 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1300 if (--bvec >= bio->bi_io_vec)
1301 prefetchw(&bvec->bv_page->flags);
1304 clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
1305 ClearPageUptodate(page);
1309 if (tree->ops && tree->ops->writepage_end_io_hook) {
1310 tree->ops->writepage_end_io_hook(page, start, end,
1315 * bios can get merged in funny ways, and so we need to
1316 * be careful with the state variable. We know the
1317 * state won't be merged with others because it has
1318 * WRITEBACK set, but we can't be sure each biovec is
1319 * sequential in the file. So, if our cached state
1320 * doesn't match the expected end, search the tree
1321 * for the correct one.
1324 spin_lock_irqsave(&tree->lock, flags);
1325 if (!state || state->end != end) {
1327 node = __tree_search(&tree->state, start, NULL, NULL);
1329 state = rb_entry(node, struct extent_state,
1331 if (state->end != end ||
1332 !(state->state & EXTENT_WRITEBACK))
1336 spin_unlock_irqrestore(&tree->lock, flags);
1337 clear_extent_writeback(tree, start,
1344 struct extent_state *clear = state;
1346 node = rb_prev(&state->rb_node);
1348 state = rb_entry(node,
1349 struct extent_state,
1355 clear_state_bit(tree, clear, EXTENT_WRITEBACK,
1366 /* before releasing the lock, make sure the next state
1367 * variable has the expected bits set and corresponds
1368 * to the correct offsets in the file
1370 if (state && (state->end + 1 != start ||
1371 !state->state & EXTENT_WRITEBACK)) {
1374 spin_unlock_irqrestore(&tree->lock, flags);
1378 end_page_writeback(page);
1380 check_page_writeback(tree, page);
1381 } while (bvec >= bio->bi_io_vec);
1383 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1389 * after a readpage IO is done, we need to:
1390 * clear the uptodate bits on error
1391 * set the uptodate bits if things worked
1392 * set the page up to date if all extents in the tree are uptodate
1393 * clear the lock bit in the extent tree
1394 * unlock the page if there are no other extents locked for it
1396 * Scheduling is not allowed, so the extent state tree is expected
1397 * to have one and only one object corresponding to this IO.
1399 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1400 static void end_bio_extent_readpage(struct bio *bio, int err)
1402 static int end_bio_extent_readpage(struct bio *bio,
1403 unsigned int bytes_done, int err)
1406 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1407 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1408 struct extent_state *state = bio->bi_private;
1409 struct extent_io_tree *tree = state->tree;
1410 struct rb_node *node;
1414 unsigned long flags;
1418 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1424 struct page *page = bvec->bv_page;
1425 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1427 end = start + bvec->bv_len - 1;
1429 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1434 if (--bvec >= bio->bi_io_vec)
1435 prefetchw(&bvec->bv_page->flags);
1437 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
1438 ret = tree->ops->readpage_end_io_hook(page, start, end,
1444 spin_lock_irqsave(&tree->lock, flags);
1445 if (!state || state->end != end) {
1447 node = __tree_search(&tree->state, start, NULL, NULL);
1449 state = rb_entry(node, struct extent_state,
1451 if (state->end != end ||
1452 !(state->state & EXTENT_LOCKED))
1456 spin_unlock_irqrestore(&tree->lock, flags);
1457 set_extent_uptodate(tree, start, end,
1459 unlock_extent(tree, start, end, GFP_ATOMIC);
1466 struct extent_state *clear = state;
1468 node = rb_prev(&state->rb_node);
1470 state = rb_entry(node,
1471 struct extent_state,
1476 clear->state |= EXTENT_UPTODATE;
1477 clear_state_bit(tree, clear, EXTENT_LOCKED,
1488 /* before releasing the lock, make sure the next state
1489 * variable has the expected bits set and corresponds
1490 * to the correct offsets in the file
1492 if (state && (state->end + 1 != start ||
1493 !state->state & EXTENT_WRITEBACK)) {
1496 spin_unlock_irqrestore(&tree->lock, flags);
1500 SetPageUptodate(page);
1502 ClearPageUptodate(page);
1508 check_page_uptodate(tree, page);
1510 ClearPageUptodate(page);
1513 check_page_locked(tree, page);
1515 } while (bvec >= bio->bi_io_vec);
1518 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1524 * IO done from prepare_write is pretty simple, we just unlock
1525 * the structs in the extent tree when done, and set the uptodate bits
1528 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1529 static void end_bio_extent_preparewrite(struct bio *bio, int err)
1531 static int end_bio_extent_preparewrite(struct bio *bio,
1532 unsigned int bytes_done, int err)
1535 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1536 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1537 struct extent_state *state = bio->bi_private;
1538 struct extent_io_tree *tree = state->tree;
1542 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1548 struct page *page = bvec->bv_page;
1549 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1551 end = start + bvec->bv_len - 1;
1553 if (--bvec >= bio->bi_io_vec)
1554 prefetchw(&bvec->bv_page->flags);
1557 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1559 ClearPageUptodate(page);
1563 unlock_extent(tree, start, end, GFP_ATOMIC);
1565 } while (bvec >= bio->bi_io_vec);
1568 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1574 extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
1579 bio = bio_alloc(gfp_flags, nr_vecs);
1581 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
1582 while (!bio && (nr_vecs /= 2))
1583 bio = bio_alloc(gfp_flags, nr_vecs);
1587 bio->bi_bdev = bdev;
1588 bio->bi_sector = first_sector;
1593 static int submit_one_bio(int rw, struct bio *bio)
1597 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1598 struct page *page = bvec->bv_page;
1599 struct extent_io_tree *tree = bio->bi_private;
1600 struct rb_node *node;
1601 struct extent_state *state;
1605 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1606 end = start + bvec->bv_len - 1;
1608 spin_lock_irq(&tree->lock);
1609 node = __tree_search(&tree->state, start, NULL, NULL);
1611 state = rb_entry(node, struct extent_state, rb_node);
1612 while(state->end < end) {
1613 node = rb_next(node);
1614 state = rb_entry(node, struct extent_state, rb_node);
1616 BUG_ON(state->end != end);
1617 spin_unlock_irq(&tree->lock);
1619 bio->bi_private = state;
1623 maxsector = bio->bi_bdev->bd_inode->i_size >> 9;
1624 if (maxsector < bio->bi_sector) {
1625 printk("sector too large max %Lu got %llu\n", maxsector,
1626 (unsigned long long)bio->bi_sector);
1630 submit_bio(rw, bio);
1631 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1637 static int submit_extent_page(int rw, struct extent_io_tree *tree,
1638 struct page *page, sector_t sector,
1639 size_t size, unsigned long offset,
1640 struct block_device *bdev,
1641 struct bio **bio_ret,
1642 unsigned long max_pages,
1643 bio_end_io_t end_io_func)
1649 if (bio_ret && *bio_ret) {
1651 if (bio->bi_sector + (bio->bi_size >> 9) != sector ||
1652 bio_add_page(bio, page, size, offset) < size) {
1653 ret = submit_one_bio(rw, bio);
1659 nr = min_t(int, max_pages, bio_get_nr_vecs(bdev));
1660 bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
1662 printk("failed to allocate bio nr %d\n", nr);
1666 bio_add_page(bio, page, size, offset);
1667 bio->bi_end_io = end_io_func;
1668 bio->bi_private = tree;
1673 ret = submit_one_bio(rw, bio);
1679 void set_page_extent_mapped(struct page *page)
1681 if (!PagePrivate(page)) {
1682 SetPagePrivate(page);
1683 WARN_ON(!page->mapping->a_ops->invalidatepage);
1684 set_page_private(page, EXTENT_PAGE_PRIVATE);
1685 page_cache_get(page);
1689 void set_page_extent_head(struct page *page, unsigned long len)
1691 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
1695 * basic readpage implementation. Locked extent state structs are inserted
1696 * into the tree that are removed when the IO is done (by the end_io
1699 static int __extent_read_full_page(struct extent_io_tree *tree,
1701 get_extent_t *get_extent,
1704 struct inode *inode = page->mapping->host;
1705 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1706 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1710 u64 last_byte = i_size_read(inode);
1714 struct extent_map *em;
1715 struct block_device *bdev;
1718 size_t page_offset = 0;
1720 size_t blocksize = inode->i_sb->s_blocksize;
1722 set_page_extent_mapped(page);
1725 lock_extent(tree, start, end, GFP_NOFS);
1727 while (cur <= end) {
1728 if (cur >= last_byte) {
1730 iosize = PAGE_CACHE_SIZE - page_offset;
1731 userpage = kmap_atomic(page, KM_USER0);
1732 memset(userpage + page_offset, 0, iosize);
1733 flush_dcache_page(page);
1734 kunmap_atomic(userpage, KM_USER0);
1735 set_extent_uptodate(tree, cur, cur + iosize - 1,
1737 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1740 em = get_extent(inode, page, page_offset, cur,
1742 if (IS_ERR(em) || !em) {
1744 unlock_extent(tree, cur, end, GFP_NOFS);
1748 extent_offset = cur - em->start;
1749 BUG_ON(extent_map_end(em) <= cur);
1752 iosize = min(extent_map_end(em) - cur, end - cur + 1);
1753 cur_end = min(extent_map_end(em) - 1, end);
1754 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
1755 sector = (em->block_start + extent_offset) >> 9;
1757 block_start = em->block_start;
1758 free_extent_map(em);
1761 /* we've found a hole, just zero and go on */
1762 if (block_start == EXTENT_MAP_HOLE) {
1764 userpage = kmap_atomic(page, KM_USER0);
1765 memset(userpage + page_offset, 0, iosize);
1766 flush_dcache_page(page);
1767 kunmap_atomic(userpage, KM_USER0);
1769 set_extent_uptodate(tree, cur, cur + iosize - 1,
1771 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1773 page_offset += iosize;
1776 /* the get_extent function already copied into the page */
1777 if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
1778 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1780 page_offset += iosize;
1783 /* we have an inline extent but it didn't get marked up
1784 * to date. Error out
1786 if (block_start == EXTENT_MAP_INLINE) {
1788 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
1790 page_offset += iosize;
1795 if (tree->ops && tree->ops->readpage_io_hook) {
1796 ret = tree->ops->readpage_io_hook(page, cur,
1800 unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
1802 ret = submit_extent_page(READ, tree, page,
1803 sector, iosize, page_offset,
1805 end_bio_extent_readpage);
1810 page_offset += iosize;
1814 if (!PageError(page))
1815 SetPageUptodate(page);
1821 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
1822 get_extent_t *get_extent)
1824 struct bio *bio = NULL;
1827 ret = __extent_read_full_page(tree, page, get_extent, &bio);
1829 submit_one_bio(READ, bio);
1832 EXPORT_SYMBOL(extent_read_full_page);
1835 * the writepage semantics are similar to regular writepage. extent
1836 * records are inserted to lock ranges in the tree, and as dirty areas
1837 * are found, they are marked writeback. Then the lock bits are removed
1838 * and the end_io handler clears the writeback ranges
1840 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
1843 struct inode *inode = page->mapping->host;
1844 struct extent_page_data *epd = data;
1845 struct extent_io_tree *tree = epd->tree;
1846 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1848 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1852 u64 last_byte = i_size_read(inode);
1856 struct extent_map *em;
1857 struct block_device *bdev;
1860 size_t page_offset = 0;
1862 loff_t i_size = i_size_read(inode);
1863 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
1867 WARN_ON(!PageLocked(page));
1868 if (page->index > end_index) {
1869 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
1874 if (page->index == end_index) {
1877 size_t offset = i_size & (PAGE_CACHE_SIZE - 1);
1879 userpage = kmap_atomic(page, KM_USER0);
1880 memset(userpage + offset, 0, PAGE_CACHE_SIZE - offset);
1881 flush_dcache_page(page);
1882 kunmap_atomic(userpage, KM_USER0);
1885 set_page_extent_mapped(page);
1887 delalloc_start = start;
1889 while(delalloc_end < page_end) {
1890 nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start,
1893 if (nr_delalloc == 0) {
1894 delalloc_start = delalloc_end + 1;
1897 tree->ops->fill_delalloc(inode, delalloc_start,
1899 clear_extent_bit(tree, delalloc_start,
1901 EXTENT_LOCKED | EXTENT_DELALLOC,
1903 delalloc_start = delalloc_end + 1;
1905 lock_extent(tree, start, page_end, GFP_NOFS);
1908 if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
1909 printk("found delalloc bits after lock_extent\n");
1912 if (last_byte <= start) {
1913 clear_extent_dirty(tree, start, page_end, GFP_NOFS);
1917 set_extent_uptodate(tree, start, page_end, GFP_NOFS);
1918 blocksize = inode->i_sb->s_blocksize;
1920 while (cur <= end) {
1921 if (cur >= last_byte) {
1922 clear_extent_dirty(tree, cur, page_end, GFP_NOFS);
1925 em = epd->get_extent(inode, page, page_offset, cur,
1927 if (IS_ERR(em) || !em) {
1932 extent_offset = cur - em->start;
1933 BUG_ON(extent_map_end(em) <= cur);
1935 iosize = min(extent_map_end(em) - cur, end - cur + 1);
1936 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
1937 sector = (em->block_start + extent_offset) >> 9;
1939 block_start = em->block_start;
1940 free_extent_map(em);
1943 if (block_start == EXTENT_MAP_HOLE ||
1944 block_start == EXTENT_MAP_INLINE) {
1945 clear_extent_dirty(tree, cur,
1946 cur + iosize - 1, GFP_NOFS);
1948 page_offset += iosize;
1952 /* leave this out until we have a page_mkwrite call */
1953 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
1956 page_offset += iosize;
1959 clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
1960 if (tree->ops && tree->ops->writepage_io_hook) {
1961 ret = tree->ops->writepage_io_hook(page, cur,
1969 unsigned long max_nr = end_index + 1;
1970 set_range_writeback(tree, cur, cur + iosize - 1);
1971 if (!PageWriteback(page)) {
1972 printk("warning page %lu not writeback, "
1973 "cur %llu end %llu\n", page->index,
1974 (unsigned long long)cur,
1975 (unsigned long long)end);
1978 ret = submit_extent_page(WRITE, tree, page, sector,
1979 iosize, page_offset, bdev,
1981 end_bio_extent_writepage);
1986 page_offset += iosize;
1991 /* make sure the mapping tag for page dirty gets cleared */
1992 set_page_writeback(page);
1993 end_page_writeback(page);
1995 unlock_extent(tree, start, page_end, GFP_NOFS);
2000 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
2002 /* Taken directly from 2.6.23 for 2.6.18 back port */
2003 typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
2007 * write_cache_pages - walk the list of dirty pages of the given address space
2008 * and write all of them.
2009 * @mapping: address space structure to write
2010 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2011 * @writepage: function called for each page
2012 * @data: data passed to writepage function
2014 * If a page is already under I/O, write_cache_pages() skips it, even
2015 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2016 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2017 * and msync() need to guarantee that all the data which was dirty at the time
2018 * the call was made get new I/O started against them. If wbc->sync_mode is
2019 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2020 * existing IO to complete.
2022 static int write_cache_pages(struct address_space *mapping,
2023 struct writeback_control *wbc, writepage_t writepage,
2026 struct backing_dev_info *bdi = mapping->backing_dev_info;
2029 struct pagevec pvec;
2032 pgoff_t end; /* Inclusive */
2034 int range_whole = 0;
2036 if (wbc->nonblocking && bdi_write_congested(bdi)) {
2037 wbc->encountered_congestion = 1;
2041 pagevec_init(&pvec, 0);
2042 if (wbc->range_cyclic) {
2043 index = mapping->writeback_index; /* Start from prev offset */
2046 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2047 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2048 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2053 while (!done && (index <= end) &&
2054 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
2055 PAGECACHE_TAG_DIRTY,
2056 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
2060 for (i = 0; i < nr_pages; i++) {
2061 struct page *page = pvec.pages[i];
2064 * At this point we hold neither mapping->tree_lock nor
2065 * lock on the page itself: the page may be truncated or
2066 * invalidated (changing page->mapping to NULL), or even
2067 * swizzled back from swapper_space to tmpfs file
2072 if (unlikely(page->mapping != mapping)) {
2077 if (!wbc->range_cyclic && page->index > end) {
2083 if (wbc->sync_mode != WB_SYNC_NONE)
2084 wait_on_page_writeback(page);
2086 if (PageWriteback(page) ||
2087 !clear_page_dirty_for_io(page)) {
2092 ret = (*writepage)(page, wbc, data);
2094 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
2098 if (ret || (--(wbc->nr_to_write) <= 0))
2100 if (wbc->nonblocking && bdi_write_congested(bdi)) {
2101 wbc->encountered_congestion = 1;
2105 pagevec_release(&pvec);
2108 if (!scanned && !done) {
2110 * We hit the last page and there is more work to be done: wrap
2111 * back to the start of the file
2117 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2118 mapping->writeback_index = index;
2123 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
2124 get_extent_t *get_extent,
2125 struct writeback_control *wbc)
2128 struct address_space *mapping = page->mapping;
2129 struct extent_page_data epd = {
2132 .get_extent = get_extent,
2134 struct writeback_control wbc_writepages = {
2136 .sync_mode = WB_SYNC_NONE,
2137 .older_than_this = NULL,
2139 .range_start = page_offset(page) + PAGE_CACHE_SIZE,
2140 .range_end = (loff_t)-1,
2144 ret = __extent_writepage(page, wbc, &epd);
2146 write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd);
2148 submit_one_bio(WRITE, epd.bio);
2152 EXPORT_SYMBOL(extent_write_full_page);
2155 int extent_writepages(struct extent_io_tree *tree,
2156 struct address_space *mapping,
2157 get_extent_t *get_extent,
2158 struct writeback_control *wbc)
2161 struct extent_page_data epd = {
2164 .get_extent = get_extent,
2167 ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd);
2169 submit_one_bio(WRITE, epd.bio);
2173 EXPORT_SYMBOL(extent_writepages);
2175 int extent_readpages(struct extent_io_tree *tree,
2176 struct address_space *mapping,
2177 struct list_head *pages, unsigned nr_pages,
2178 get_extent_t get_extent)
2180 struct bio *bio = NULL;
2182 struct pagevec pvec;
2184 pagevec_init(&pvec, 0);
2185 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
2186 struct page *page = list_entry(pages->prev, struct page, lru);
2188 prefetchw(&page->flags);
2189 list_del(&page->lru);
2191 * what we want to do here is call add_to_page_cache_lru,
2192 * but that isn't exported, so we reproduce it here
2194 if (!add_to_page_cache(page, mapping,
2195 page->index, GFP_KERNEL)) {
2197 /* open coding of lru_cache_add, also not exported */
2198 page_cache_get(page);
2199 if (!pagevec_add(&pvec, page))
2200 __pagevec_lru_add(&pvec);
2201 __extent_read_full_page(tree, page, get_extent, &bio);
2203 page_cache_release(page);
2205 if (pagevec_count(&pvec))
2206 __pagevec_lru_add(&pvec);
2207 BUG_ON(!list_empty(pages));
2209 submit_one_bio(READ, bio);
2212 EXPORT_SYMBOL(extent_readpages);
2215 * basic invalidatepage code, this waits on any locked or writeback
2216 * ranges corresponding to the page, and then deletes any extent state
2217 * records from the tree
2219 int extent_invalidatepage(struct extent_io_tree *tree,
2220 struct page *page, unsigned long offset)
2222 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
2223 u64 end = start + PAGE_CACHE_SIZE - 1;
2224 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
2226 start += (offset + blocksize -1) & ~(blocksize - 1);
2230 lock_extent(tree, start, end, GFP_NOFS);
2231 wait_on_extent_writeback(tree, start, end);
2232 clear_extent_bit(tree, start, end,
2233 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
2237 EXPORT_SYMBOL(extent_invalidatepage);
2240 * simple commit_write call, set_range_dirty is used to mark both
2241 * the pages and the extent records as dirty
2243 int extent_commit_write(struct extent_io_tree *tree,
2244 struct inode *inode, struct page *page,
2245 unsigned from, unsigned to)
2247 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
2249 set_page_extent_mapped(page);
2250 set_page_dirty(page);
2252 if (pos > inode->i_size) {
2253 i_size_write(inode, pos);
2254 mark_inode_dirty(inode);
2258 EXPORT_SYMBOL(extent_commit_write);
2260 int extent_prepare_write(struct extent_io_tree *tree,
2261 struct inode *inode, struct page *page,
2262 unsigned from, unsigned to, get_extent_t *get_extent)
2264 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2265 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
2267 u64 orig_block_start;
2270 struct extent_map *em;
2271 unsigned blocksize = 1 << inode->i_blkbits;
2272 size_t page_offset = 0;
2273 size_t block_off_start;
2274 size_t block_off_end;
2280 set_page_extent_mapped(page);
2282 block_start = (page_start + from) & ~((u64)blocksize - 1);
2283 block_end = (page_start + to - 1) | (blocksize - 1);
2284 orig_block_start = block_start;
2286 lock_extent(tree, page_start, page_end, GFP_NOFS);
2287 while(block_start <= block_end) {
2288 em = get_extent(inode, page, page_offset, block_start,
2289 block_end - block_start + 1, 1);
2290 if (IS_ERR(em) || !em) {
2293 cur_end = min(block_end, extent_map_end(em) - 1);
2294 block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
2295 block_off_end = block_off_start + blocksize;
2296 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
2298 if (!PageUptodate(page) && isnew &&
2299 (block_off_end > to || block_off_start < from)) {
2302 kaddr = kmap_atomic(page, KM_USER0);
2303 if (block_off_end > to)
2304 memset(kaddr + to, 0, block_off_end - to);
2305 if (block_off_start < from)
2306 memset(kaddr + block_off_start, 0,
2307 from - block_off_start);
2308 flush_dcache_page(page);
2309 kunmap_atomic(kaddr, KM_USER0);
2311 if ((em->block_start != EXTENT_MAP_HOLE &&
2312 em->block_start != EXTENT_MAP_INLINE) &&
2313 !isnew && !PageUptodate(page) &&
2314 (block_off_end > to || block_off_start < from) &&
2315 !test_range_bit(tree, block_start, cur_end,
2316 EXTENT_UPTODATE, 1)) {
2318 u64 extent_offset = block_start - em->start;
2320 sector = (em->block_start + extent_offset) >> 9;
2321 iosize = (cur_end - block_start + blocksize) &
2322 ~((u64)blocksize - 1);
2324 * we've already got the extent locked, but we
2325 * need to split the state such that our end_bio
2326 * handler can clear the lock.
2328 set_extent_bit(tree, block_start,
2329 block_start + iosize - 1,
2330 EXTENT_LOCKED, 0, NULL, GFP_NOFS);
2331 ret = submit_extent_page(READ, tree, page,
2332 sector, iosize, page_offset, em->bdev,
2334 end_bio_extent_preparewrite);
2336 block_start = block_start + iosize;
2338 set_extent_uptodate(tree, block_start, cur_end,
2340 unlock_extent(tree, block_start, cur_end, GFP_NOFS);
2341 block_start = cur_end + 1;
2343 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
2344 free_extent_map(em);
2347 wait_extent_bit(tree, orig_block_start,
2348 block_end, EXTENT_LOCKED);
2350 check_page_uptodate(tree, page);
2352 /* FIXME, zero out newly allocated blocks on error */
2355 EXPORT_SYMBOL(extent_prepare_write);
2358 * a helper for releasepage. As long as there are no locked extents
2359 * in the range corresponding to the page, both state records and extent
2360 * map records are removed
2362 int try_release_extent_mapping(struct extent_map_tree *map,
2363 struct extent_io_tree *tree, struct page *page,
2366 struct extent_map *em;
2367 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2368 u64 end = start + PAGE_CACHE_SIZE - 1;
2369 u64 orig_start = start;
2372 if ((mask & __GFP_WAIT) &&
2373 page->mapping->host->i_size > 16 * 1024 * 1024) {
2374 while (start <= end) {
2375 spin_lock(&map->lock);
2376 em = lookup_extent_mapping(map, start, end);
2377 if (!em || IS_ERR(em)) {
2378 spin_unlock(&map->lock);
2381 if (em->start != start) {
2382 spin_unlock(&map->lock);
2383 free_extent_map(em);
2386 if (!test_range_bit(tree, em->start,
2387 extent_map_end(em) - 1,
2388 EXTENT_LOCKED, 0)) {
2389 remove_extent_mapping(map, em);
2390 /* once for the rb tree */
2391 free_extent_map(em);
2393 start = extent_map_end(em);
2394 spin_unlock(&map->lock);
2397 free_extent_map(em);
2400 if (test_range_bit(tree, orig_start, end, EXTENT_IOBITS, 0))
2403 if ((mask & GFP_NOFS) == GFP_NOFS)
2405 clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE,
2410 EXPORT_SYMBOL(try_release_extent_mapping);
2412 sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
2413 get_extent_t *get_extent)
2415 struct inode *inode = mapping->host;
2416 u64 start = iblock << inode->i_blkbits;
2417 sector_t sector = 0;
2418 struct extent_map *em;
2420 em = get_extent(inode, NULL, 0, start, (1 << inode->i_blkbits), 0);
2421 if (!em || IS_ERR(em))
2424 if (em->block_start == EXTENT_MAP_INLINE ||
2425 em->block_start == EXTENT_MAP_HOLE)
2428 sector = (em->block_start + start - em->start) >> inode->i_blkbits;
2429 printk("bmap finds %Lu %Lu block %Lu\n", em->start, em->len, em->block_start);
2431 free_extent_map(em);
2435 static int add_lru(struct extent_io_tree *tree, struct extent_buffer *eb)
2437 if (list_empty(&eb->lru)) {
2438 extent_buffer_get(eb);
2439 list_add(&eb->lru, &tree->buffer_lru);
2441 if (tree->lru_size >= BUFFER_LRU_MAX) {
2442 struct extent_buffer *rm;
2443 rm = list_entry(tree->buffer_lru.prev,
2444 struct extent_buffer, lru);
2446 list_del_init(&rm->lru);
2447 free_extent_buffer(rm);
2450 list_move(&eb->lru, &tree->buffer_lru);
2453 static struct extent_buffer *find_lru(struct extent_io_tree *tree,
2454 u64 start, unsigned long len)
2456 struct list_head *lru = &tree->buffer_lru;
2457 struct list_head *cur = lru->next;
2458 struct extent_buffer *eb;
2460 if (list_empty(lru))
2464 eb = list_entry(cur, struct extent_buffer, lru);
2465 if (eb->start == start && eb->len == len) {
2466 extent_buffer_get(eb);
2470 } while (cur != lru);
2474 static inline unsigned long num_extent_pages(u64 start, u64 len)
2476 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
2477 (start >> PAGE_CACHE_SHIFT);
2480 static inline struct page *extent_buffer_page(struct extent_buffer *eb,
2484 struct address_space *mapping;
2487 return eb->first_page;
2488 i += eb->start >> PAGE_CACHE_SHIFT;
2489 mapping = eb->first_page->mapping;
2490 read_lock_irq(&mapping->tree_lock);
2491 p = radix_tree_lookup(&mapping->page_tree, i);
2492 read_unlock_irq(&mapping->tree_lock);
2496 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
2501 struct extent_buffer *eb = NULL;
2503 spin_lock(&tree->lru_lock);
2504 eb = find_lru(tree, start, len);
2505 spin_unlock(&tree->lru_lock);
2510 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
2511 INIT_LIST_HEAD(&eb->lru);
2514 atomic_set(&eb->refs, 1);
2519 static void __free_extent_buffer(struct extent_buffer *eb)
2521 kmem_cache_free(extent_buffer_cache, eb);
2524 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
2525 u64 start, unsigned long len,
2529 unsigned long num_pages = num_extent_pages(start, len);
2531 unsigned long index = start >> PAGE_CACHE_SHIFT;
2532 struct extent_buffer *eb;
2534 struct address_space *mapping = tree->mapping;
2537 eb = __alloc_extent_buffer(tree, start, len, mask);
2538 if (!eb || IS_ERR(eb))
2541 if (eb->flags & EXTENT_BUFFER_FILLED)
2545 eb->first_page = page0;
2548 page_cache_get(page0);
2549 mark_page_accessed(page0);
2550 set_page_extent_mapped(page0);
2551 WARN_ON(!PageUptodate(page0));
2552 set_page_extent_head(page0, len);
2556 for (; i < num_pages; i++, index++) {
2557 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
2562 set_page_extent_mapped(p);
2563 mark_page_accessed(p);
2566 set_page_extent_head(p, len);
2568 set_page_private(p, EXTENT_PAGE_PRIVATE);
2570 if (!PageUptodate(p))
2575 eb->flags |= EXTENT_UPTODATE;
2576 eb->flags |= EXTENT_BUFFER_FILLED;
2579 spin_lock(&tree->lru_lock);
2581 spin_unlock(&tree->lru_lock);
2585 spin_lock(&tree->lru_lock);
2586 list_del_init(&eb->lru);
2587 spin_unlock(&tree->lru_lock);
2588 if (!atomic_dec_and_test(&eb->refs))
2590 for (index = 1; index < i; index++) {
2591 page_cache_release(extent_buffer_page(eb, index));
2594 page_cache_release(extent_buffer_page(eb, 0));
2595 __free_extent_buffer(eb);
2598 EXPORT_SYMBOL(alloc_extent_buffer);
2600 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
2601 u64 start, unsigned long len,
2604 unsigned long num_pages = num_extent_pages(start, len);
2606 unsigned long index = start >> PAGE_CACHE_SHIFT;
2607 struct extent_buffer *eb;
2609 struct address_space *mapping = tree->mapping;
2612 eb = __alloc_extent_buffer(tree, start, len, mask);
2613 if (!eb || IS_ERR(eb))
2616 if (eb->flags & EXTENT_BUFFER_FILLED)
2619 for (i = 0; i < num_pages; i++, index++) {
2620 p = find_lock_page(mapping, index);
2624 set_page_extent_mapped(p);
2625 mark_page_accessed(p);
2629 set_page_extent_head(p, len);
2631 set_page_private(p, EXTENT_PAGE_PRIVATE);
2634 if (!PageUptodate(p))
2639 eb->flags |= EXTENT_UPTODATE;
2640 eb->flags |= EXTENT_BUFFER_FILLED;
2643 spin_lock(&tree->lru_lock);
2645 spin_unlock(&tree->lru_lock);
2648 spin_lock(&tree->lru_lock);
2649 list_del_init(&eb->lru);
2650 spin_unlock(&tree->lru_lock);
2651 if (!atomic_dec_and_test(&eb->refs))
2653 for (index = 1; index < i; index++) {
2654 page_cache_release(extent_buffer_page(eb, index));
2657 page_cache_release(extent_buffer_page(eb, 0));
2658 __free_extent_buffer(eb);
2661 EXPORT_SYMBOL(find_extent_buffer);
2663 void free_extent_buffer(struct extent_buffer *eb)
2666 unsigned long num_pages;
2671 if (!atomic_dec_and_test(&eb->refs))
2674 WARN_ON(!list_empty(&eb->lru));
2675 num_pages = num_extent_pages(eb->start, eb->len);
2677 for (i = 1; i < num_pages; i++) {
2678 page_cache_release(extent_buffer_page(eb, i));
2680 page_cache_release(extent_buffer_page(eb, 0));
2681 __free_extent_buffer(eb);
2683 EXPORT_SYMBOL(free_extent_buffer);
2685 int clear_extent_buffer_dirty(struct extent_io_tree *tree,
2686 struct extent_buffer *eb)
2690 unsigned long num_pages;
2693 u64 start = eb->start;
2694 u64 end = start + eb->len - 1;
2696 set = clear_extent_dirty(tree, start, end, GFP_NOFS);
2697 num_pages = num_extent_pages(eb->start, eb->len);
2699 for (i = 0; i < num_pages; i++) {
2700 page = extent_buffer_page(eb, i);
2703 set_page_extent_head(page, eb->len);
2705 set_page_private(page, EXTENT_PAGE_PRIVATE);
2708 * if we're on the last page or the first page and the
2709 * block isn't aligned on a page boundary, do extra checks
2710 * to make sure we don't clean page that is partially dirty
2712 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
2713 ((i == num_pages - 1) &&
2714 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
2715 start = (u64)page->index << PAGE_CACHE_SHIFT;
2716 end = start + PAGE_CACHE_SIZE - 1;
2717 if (test_range_bit(tree, start, end,
2723 clear_page_dirty_for_io(page);
2724 read_lock_irq(&page->mapping->tree_lock);
2725 if (!PageDirty(page)) {
2726 radix_tree_tag_clear(&page->mapping->page_tree,
2728 PAGECACHE_TAG_DIRTY);
2730 read_unlock_irq(&page->mapping->tree_lock);
2735 EXPORT_SYMBOL(clear_extent_buffer_dirty);
2737 int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
2738 struct extent_buffer *eb)
2740 return wait_on_extent_writeback(tree, eb->start,
2741 eb->start + eb->len - 1);
2743 EXPORT_SYMBOL(wait_on_extent_buffer_writeback);
2745 int set_extent_buffer_dirty(struct extent_io_tree *tree,
2746 struct extent_buffer *eb)
2749 unsigned long num_pages;
2751 num_pages = num_extent_pages(eb->start, eb->len);
2752 for (i = 0; i < num_pages; i++) {
2753 struct page *page = extent_buffer_page(eb, i);
2754 /* writepage may need to do something special for the
2755 * first page, we have to make sure page->private is
2756 * properly set. releasepage may drop page->private
2757 * on us if the page isn't already dirty.
2761 set_page_extent_head(page, eb->len);
2762 } else if (PagePrivate(page) &&
2763 page->private != EXTENT_PAGE_PRIVATE) {
2765 set_page_extent_mapped(page);
2768 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
2772 return set_extent_dirty(tree, eb->start,
2773 eb->start + eb->len - 1, GFP_NOFS);
2775 EXPORT_SYMBOL(set_extent_buffer_dirty);
2777 int set_extent_buffer_uptodate(struct extent_io_tree *tree,
2778 struct extent_buffer *eb)
2782 unsigned long num_pages;
2784 num_pages = num_extent_pages(eb->start, eb->len);
2786 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
2788 for (i = 0; i < num_pages; i++) {
2789 page = extent_buffer_page(eb, i);
2790 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
2791 ((i == num_pages - 1) &&
2792 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
2793 check_page_uptodate(tree, page);
2796 SetPageUptodate(page);
2800 EXPORT_SYMBOL(set_extent_buffer_uptodate);
2802 int extent_buffer_uptodate(struct extent_io_tree *tree,
2803 struct extent_buffer *eb)
2805 if (eb->flags & EXTENT_UPTODATE)
2807 return test_range_bit(tree, eb->start, eb->start + eb->len - 1,
2808 EXTENT_UPTODATE, 1);
2810 EXPORT_SYMBOL(extent_buffer_uptodate);
2812 int read_extent_buffer_pages(struct extent_io_tree *tree,
2813 struct extent_buffer *eb,
2818 unsigned long start_i;
2822 unsigned long num_pages;
2824 if (eb->flags & EXTENT_UPTODATE)
2827 if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1,
2828 EXTENT_UPTODATE, 1)) {
2833 WARN_ON(start < eb->start);
2834 start_i = (start >> PAGE_CACHE_SHIFT) -
2835 (eb->start >> PAGE_CACHE_SHIFT);
2840 num_pages = num_extent_pages(eb->start, eb->len);
2841 for (i = start_i; i < num_pages; i++) {
2842 page = extent_buffer_page(eb, i);
2843 if (PageUptodate(page)) {
2847 if (TestSetPageLocked(page)) {
2853 if (!PageUptodate(page)) {
2854 err = page->mapping->a_ops->readpage(NULL, page);
2867 for (i = start_i; i < num_pages; i++) {
2868 page = extent_buffer_page(eb, i);
2869 wait_on_page_locked(page);
2870 if (!PageUptodate(page)) {
2875 eb->flags |= EXTENT_UPTODATE;
2878 EXPORT_SYMBOL(read_extent_buffer_pages);
2880 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
2881 unsigned long start,
2888 char *dst = (char *)dstv;
2889 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
2890 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
2891 unsigned long num_pages = num_extent_pages(eb->start, eb->len);
2893 WARN_ON(start > eb->len);
2894 WARN_ON(start + len > eb->start + eb->len);
2896 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
2899 page = extent_buffer_page(eb, i);
2900 if (!PageUptodate(page)) {
2901 printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len);
2904 WARN_ON(!PageUptodate(page));
2906 cur = min(len, (PAGE_CACHE_SIZE - offset));
2907 kaddr = kmap_atomic(page, KM_USER1);
2908 memcpy(dst, kaddr + offset, cur);
2909 kunmap_atomic(kaddr, KM_USER1);
2917 EXPORT_SYMBOL(read_extent_buffer);
2919 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
2920 unsigned long min_len, char **token, char **map,
2921 unsigned long *map_start,
2922 unsigned long *map_len, int km)
2924 size_t offset = start & (PAGE_CACHE_SIZE - 1);
2927 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
2928 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
2929 unsigned long end_i = (start_offset + start + min_len - 1) >>
2936 offset = start_offset;
2940 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
2942 if (start + min_len > eb->len) {
2943 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len);
2947 p = extent_buffer_page(eb, i);
2948 WARN_ON(!PageUptodate(p));
2949 kaddr = kmap_atomic(p, km);
2951 *map = kaddr + offset;
2952 *map_len = PAGE_CACHE_SIZE - offset;
2955 EXPORT_SYMBOL(map_private_extent_buffer);
2957 int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
2958 unsigned long min_len,
2959 char **token, char **map,
2960 unsigned long *map_start,
2961 unsigned long *map_len, int km)
2965 if (eb->map_token) {
2966 unmap_extent_buffer(eb, eb->map_token, km);
2967 eb->map_token = NULL;
2970 err = map_private_extent_buffer(eb, start, min_len, token, map,
2971 map_start, map_len, km);
2973 eb->map_token = *token;
2975 eb->map_start = *map_start;
2976 eb->map_len = *map_len;
2980 EXPORT_SYMBOL(map_extent_buffer);
2982 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
2984 kunmap_atomic(token, km);
2986 EXPORT_SYMBOL(unmap_extent_buffer);
2988 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
2989 unsigned long start,
2996 char *ptr = (char *)ptrv;
2997 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
2998 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3001 WARN_ON(start > eb->len);
3002 WARN_ON(start + len > eb->start + eb->len);
3004 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3007 page = extent_buffer_page(eb, i);
3008 WARN_ON(!PageUptodate(page));
3010 cur = min(len, (PAGE_CACHE_SIZE - offset));
3012 kaddr = kmap_atomic(page, KM_USER0);
3013 ret = memcmp(ptr, kaddr + offset, cur);
3014 kunmap_atomic(kaddr, KM_USER0);
3025 EXPORT_SYMBOL(memcmp_extent_buffer);
3027 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
3028 unsigned long start, unsigned long len)
3034 char *src = (char *)srcv;
3035 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3036 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3038 WARN_ON(start > eb->len);
3039 WARN_ON(start + len > eb->start + eb->len);
3041 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3044 page = extent_buffer_page(eb, i);
3045 WARN_ON(!PageUptodate(page));
3047 cur = min(len, PAGE_CACHE_SIZE - offset);
3048 kaddr = kmap_atomic(page, KM_USER1);
3049 memcpy(kaddr + offset, src, cur);
3050 kunmap_atomic(kaddr, KM_USER1);
3058 EXPORT_SYMBOL(write_extent_buffer);
3060 void memset_extent_buffer(struct extent_buffer *eb, char c,
3061 unsigned long start, unsigned long len)
3067 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3068 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3070 WARN_ON(start > eb->len);
3071 WARN_ON(start + len > eb->start + eb->len);
3073 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3076 page = extent_buffer_page(eb, i);
3077 WARN_ON(!PageUptodate(page));
3079 cur = min(len, PAGE_CACHE_SIZE - offset);
3080 kaddr = kmap_atomic(page, KM_USER0);
3081 memset(kaddr + offset, c, cur);
3082 kunmap_atomic(kaddr, KM_USER0);
3089 EXPORT_SYMBOL(memset_extent_buffer);
3091 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
3092 unsigned long dst_offset, unsigned long src_offset,
3095 u64 dst_len = dst->len;
3100 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3101 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3103 WARN_ON(src->len != dst_len);
3105 offset = (start_offset + dst_offset) &
3106 ((unsigned long)PAGE_CACHE_SIZE - 1);
3109 page = extent_buffer_page(dst, i);
3110 WARN_ON(!PageUptodate(page));
3112 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
3114 kaddr = kmap_atomic(page, KM_USER0);
3115 read_extent_buffer(src, kaddr + offset, src_offset, cur);
3116 kunmap_atomic(kaddr, KM_USER0);
3124 EXPORT_SYMBOL(copy_extent_buffer);
3126 static void move_pages(struct page *dst_page, struct page *src_page,
3127 unsigned long dst_off, unsigned long src_off,
3130 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3131 if (dst_page == src_page) {
3132 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
3134 char *src_kaddr = kmap_atomic(src_page, KM_USER1);
3135 char *p = dst_kaddr + dst_off + len;
3136 char *s = src_kaddr + src_off + len;
3141 kunmap_atomic(src_kaddr, KM_USER1);
3143 kunmap_atomic(dst_kaddr, KM_USER0);
3146 static void copy_pages(struct page *dst_page, struct page *src_page,
3147 unsigned long dst_off, unsigned long src_off,
3150 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3153 if (dst_page != src_page)
3154 src_kaddr = kmap_atomic(src_page, KM_USER1);
3156 src_kaddr = dst_kaddr;
3158 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
3159 kunmap_atomic(dst_kaddr, KM_USER0);
3160 if (dst_page != src_page)
3161 kunmap_atomic(src_kaddr, KM_USER1);
3164 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3165 unsigned long src_offset, unsigned long len)
3168 size_t dst_off_in_page;
3169 size_t src_off_in_page;
3170 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3171 unsigned long dst_i;
3172 unsigned long src_i;
3174 if (src_offset + len > dst->len) {
3175 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
3176 src_offset, len, dst->len);
3179 if (dst_offset + len > dst->len) {
3180 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
3181 dst_offset, len, dst->len);
3186 dst_off_in_page = (start_offset + dst_offset) &
3187 ((unsigned long)PAGE_CACHE_SIZE - 1);
3188 src_off_in_page = (start_offset + src_offset) &
3189 ((unsigned long)PAGE_CACHE_SIZE - 1);
3191 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3192 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
3194 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
3196 cur = min_t(unsigned long, cur,
3197 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
3199 copy_pages(extent_buffer_page(dst, dst_i),
3200 extent_buffer_page(dst, src_i),
3201 dst_off_in_page, src_off_in_page, cur);
3208 EXPORT_SYMBOL(memcpy_extent_buffer);
3210 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3211 unsigned long src_offset, unsigned long len)
3214 size_t dst_off_in_page;
3215 size_t src_off_in_page;
3216 unsigned long dst_end = dst_offset + len - 1;
3217 unsigned long src_end = src_offset + len - 1;
3218 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3219 unsigned long dst_i;
3220 unsigned long src_i;
3222 if (src_offset + len > dst->len) {
3223 printk("memmove bogus src_offset %lu move len %lu len %lu\n",
3224 src_offset, len, dst->len);
3227 if (dst_offset + len > dst->len) {
3228 printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
3229 dst_offset, len, dst->len);
3232 if (dst_offset < src_offset) {
3233 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
3237 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
3238 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
3240 dst_off_in_page = (start_offset + dst_end) &
3241 ((unsigned long)PAGE_CACHE_SIZE - 1);
3242 src_off_in_page = (start_offset + src_end) &
3243 ((unsigned long)PAGE_CACHE_SIZE - 1);
3245 cur = min_t(unsigned long, len, src_off_in_page + 1);
3246 cur = min(cur, dst_off_in_page + 1);
3247 move_pages(extent_buffer_page(dst, dst_i),
3248 extent_buffer_page(dst, src_i),
3249 dst_off_in_page - cur + 1,
3250 src_off_in_page - cur + 1, cur);
3257 EXPORT_SYMBOL(memmove_extent_buffer);