1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/module.h>
8 #include <linux/spinlock.h>
9 #include <linux/blkdev.h>
10 #include <linux/swap.h>
11 #include <linux/writeback.h>
12 #include <linux/pagevec.h>
13 #include <linux/prefetch.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
18 #include "btrfs_inode.h"
20 static struct kmem_cache *extent_state_cache;
21 static struct kmem_cache *extent_buffer_cache;
23 static LIST_HEAD(buffers);
24 static LIST_HEAD(states);
28 static DEFINE_SPINLOCK(leak_lock);
31 #define BUFFER_LRU_MAX 64
36 struct rb_node rb_node;
39 struct extent_page_data {
41 struct extent_io_tree *tree;
42 get_extent_t *get_extent;
44 /* tells writepage not to lock the state bits for this range
45 * it still does the unlocking
47 unsigned int extent_locked:1;
49 /* tells the submit_bio code to use a WRITE_SYNC */
50 unsigned int sync_io:1;
53 int __init extent_io_init(void)
55 extent_state_cache = kmem_cache_create("extent_state",
56 sizeof(struct extent_state), 0,
57 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
58 if (!extent_state_cache)
61 extent_buffer_cache = kmem_cache_create("extent_buffers",
62 sizeof(struct extent_buffer), 0,
63 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
64 if (!extent_buffer_cache)
65 goto free_state_cache;
69 kmem_cache_destroy(extent_state_cache);
73 void extent_io_exit(void)
75 struct extent_state *state;
76 struct extent_buffer *eb;
78 while (!list_empty(&states)) {
79 state = list_entry(states.next, struct extent_state, leak_list);
80 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
81 "state %lu in tree %p refs %d\n",
82 (unsigned long long)state->start,
83 (unsigned long long)state->end,
84 state->state, state->tree, atomic_read(&state->refs));
85 list_del(&state->leak_list);
86 kmem_cache_free(extent_state_cache, state);
90 while (!list_empty(&buffers)) {
91 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
92 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
93 "refs %d\n", (unsigned long long)eb->start,
94 eb->len, atomic_read(&eb->refs));
95 list_del(&eb->leak_list);
96 kmem_cache_free(extent_buffer_cache, eb);
98 if (extent_state_cache)
99 kmem_cache_destroy(extent_state_cache);
100 if (extent_buffer_cache)
101 kmem_cache_destroy(extent_buffer_cache);
104 void extent_io_tree_init(struct extent_io_tree *tree,
105 struct address_space *mapping, gfp_t mask)
107 tree->state = RB_ROOT;
108 INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
110 tree->dirty_bytes = 0;
111 spin_lock_init(&tree->lock);
112 spin_lock_init(&tree->buffer_lock);
113 tree->mapping = mapping;
116 static struct extent_state *alloc_extent_state(gfp_t mask)
118 struct extent_state *state;
123 state = kmem_cache_alloc(extent_state_cache, mask);
130 spin_lock_irqsave(&leak_lock, flags);
131 list_add(&state->leak_list, &states);
132 spin_unlock_irqrestore(&leak_lock, flags);
134 atomic_set(&state->refs, 1);
135 init_waitqueue_head(&state->wq);
139 void free_extent_state(struct extent_state *state)
143 if (atomic_dec_and_test(&state->refs)) {
147 WARN_ON(state->tree);
149 spin_lock_irqsave(&leak_lock, flags);
150 list_del(&state->leak_list);
151 spin_unlock_irqrestore(&leak_lock, flags);
153 kmem_cache_free(extent_state_cache, state);
157 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
158 struct rb_node *node)
160 struct rb_node **p = &root->rb_node;
161 struct rb_node *parent = NULL;
162 struct tree_entry *entry;
166 entry = rb_entry(parent, struct tree_entry, rb_node);
168 if (offset < entry->start)
170 else if (offset > entry->end)
176 entry = rb_entry(node, struct tree_entry, rb_node);
177 rb_link_node(node, parent, p);
178 rb_insert_color(node, root);
182 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
183 struct rb_node **prev_ret,
184 struct rb_node **next_ret)
186 struct rb_root *root = &tree->state;
187 struct rb_node *n = root->rb_node;
188 struct rb_node *prev = NULL;
189 struct rb_node *orig_prev = NULL;
190 struct tree_entry *entry;
191 struct tree_entry *prev_entry = NULL;
194 entry = rb_entry(n, struct tree_entry, rb_node);
198 if (offset < entry->start)
200 else if (offset > entry->end)
208 while (prev && offset > prev_entry->end) {
209 prev = rb_next(prev);
210 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
217 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
218 while (prev && offset < prev_entry->start) {
219 prev = rb_prev(prev);
220 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
227 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
230 struct rb_node *prev = NULL;
233 ret = __etree_search(tree, offset, &prev, NULL);
239 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
240 struct extent_state *other)
242 if (tree->ops && tree->ops->merge_extent_hook)
243 tree->ops->merge_extent_hook(tree->mapping->host, new,
248 * utility function to look for merge candidates inside a given range.
249 * Any extents with matching state are merged together into a single
250 * extent in the tree. Extents with EXTENT_IO in their state field
251 * are not merged because the end_io handlers need to be able to do
252 * operations on them without sleeping (or doing allocations/splits).
254 * This should be called with the tree lock held.
256 static int merge_state(struct extent_io_tree *tree,
257 struct extent_state *state)
259 struct extent_state *other;
260 struct rb_node *other_node;
262 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
265 other_node = rb_prev(&state->rb_node);
267 other = rb_entry(other_node, struct extent_state, rb_node);
268 if (other->end == state->start - 1 &&
269 other->state == state->state) {
270 merge_cb(tree, state, other);
271 state->start = other->start;
273 rb_erase(&other->rb_node, &tree->state);
274 free_extent_state(other);
277 other_node = rb_next(&state->rb_node);
279 other = rb_entry(other_node, struct extent_state, rb_node);
280 if (other->start == state->end + 1 &&
281 other->state == state->state) {
282 merge_cb(tree, state, other);
283 other->start = state->start;
285 rb_erase(&state->rb_node, &tree->state);
286 free_extent_state(state);
294 static int set_state_cb(struct extent_io_tree *tree,
295 struct extent_state *state, int *bits)
297 if (tree->ops && tree->ops->set_bit_hook) {
298 return tree->ops->set_bit_hook(tree->mapping->host,
305 static void clear_state_cb(struct extent_io_tree *tree,
306 struct extent_state *state, int *bits)
308 if (tree->ops && tree->ops->clear_bit_hook)
309 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
313 * insert an extent_state struct into the tree. 'bits' are set on the
314 * struct before it is inserted.
316 * This may return -EEXIST if the extent is already there, in which case the
317 * state struct is freed.
319 * The tree lock is not taken internally. This is a utility function and
320 * probably isn't what you want to call (see set/clear_extent_bit).
322 static int insert_state(struct extent_io_tree *tree,
323 struct extent_state *state, u64 start, u64 end,
326 struct rb_node *node;
327 int bits_to_set = *bits & ~EXTENT_CTLBITS;
331 printk(KERN_ERR "btrfs end < start %llu %llu\n",
332 (unsigned long long)end,
333 (unsigned long long)start);
336 state->start = start;
338 ret = set_state_cb(tree, state, bits);
342 if (bits_to_set & EXTENT_DIRTY)
343 tree->dirty_bytes += end - start + 1;
344 state->state |= bits_to_set;
345 node = tree_insert(&tree->state, end, &state->rb_node);
347 struct extent_state *found;
348 found = rb_entry(node, struct extent_state, rb_node);
349 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
350 "%llu %llu\n", (unsigned long long)found->start,
351 (unsigned long long)found->end,
352 (unsigned long long)start, (unsigned long long)end);
353 free_extent_state(state);
357 merge_state(tree, state);
361 static int split_cb(struct extent_io_tree *tree, struct extent_state *orig,
364 if (tree->ops && tree->ops->split_extent_hook)
365 return tree->ops->split_extent_hook(tree->mapping->host,
371 * split a given extent state struct in two, inserting the preallocated
372 * struct 'prealloc' as the newly created second half. 'split' indicates an
373 * offset inside 'orig' where it should be split.
376 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
377 * are two extent state structs in the tree:
378 * prealloc: [orig->start, split - 1]
379 * orig: [ split, orig->end ]
381 * The tree locks are not taken by this function. They need to be held
384 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
385 struct extent_state *prealloc, u64 split)
387 struct rb_node *node;
389 split_cb(tree, orig, split);
391 prealloc->start = orig->start;
392 prealloc->end = split - 1;
393 prealloc->state = orig->state;
396 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
398 free_extent_state(prealloc);
401 prealloc->tree = tree;
406 * utility function to clear some bits in an extent state struct.
407 * it will optionally wake up any one waiting on this state (wake == 1), or
408 * forcibly remove the state from the tree (delete == 1).
410 * If no bits are set on the state struct after clearing things, the
411 * struct is freed and removed from the tree
413 static int clear_state_bit(struct extent_io_tree *tree,
414 struct extent_state *state,
417 int bits_to_clear = *bits & ~EXTENT_CTLBITS;
418 int ret = state->state & bits_to_clear;
420 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
421 u64 range = state->end - state->start + 1;
422 WARN_ON(range > tree->dirty_bytes);
423 tree->dirty_bytes -= range;
425 clear_state_cb(tree, state, bits);
426 state->state &= ~bits_to_clear;
429 if (state->state == 0) {
431 rb_erase(&state->rb_node, &tree->state);
433 free_extent_state(state);
438 merge_state(tree, state);
444 * clear some bits on a range in the tree. This may require splitting
445 * or inserting elements in the tree, so the gfp mask is used to
446 * indicate which allocations or sleeping are allowed.
448 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
449 * the given range from the tree regardless of state (ie for truncate).
451 * the range [start, end] is inclusive.
453 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
454 * bits were already set, or zero if none of the bits were already set.
456 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
457 int bits, int wake, int delete,
458 struct extent_state **cached_state,
461 struct extent_state *state;
462 struct extent_state *cached;
463 struct extent_state *prealloc = NULL;
464 struct rb_node *next_node;
465 struct rb_node *node;
472 bits |= ~EXTENT_CTLBITS;
473 bits |= EXTENT_FIRST_DELALLOC;
475 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
478 if (!prealloc && (mask & __GFP_WAIT)) {
479 prealloc = alloc_extent_state(mask);
484 spin_lock(&tree->lock);
486 cached = *cached_state;
489 *cached_state = NULL;
493 if (cached && cached->tree && cached->start == start) {
495 atomic_dec(&cached->refs);
500 free_extent_state(cached);
503 * this search will find the extents that end after
506 node = tree_search(tree, start);
509 state = rb_entry(node, struct extent_state, rb_node);
511 if (state->start > end)
513 WARN_ON(state->end < start);
514 last_end = state->end;
517 * | ---- desired range ---- |
519 * | ------------- state -------------- |
521 * We need to split the extent we found, and may flip
522 * bits on second half.
524 * If the extent we found extends past our range, we
525 * just split and search again. It'll get split again
526 * the next time though.
528 * If the extent we found is inside our range, we clear
529 * the desired bit on it.
532 if (state->start < start) {
534 prealloc = alloc_extent_state(GFP_ATOMIC);
535 err = split_state(tree, state, prealloc, start);
536 BUG_ON(err == -EEXIST);
540 if (state->end <= end) {
541 set |= clear_state_bit(tree, state, &bits, wake);
542 if (last_end == (u64)-1)
544 start = last_end + 1;
549 * | ---- desired range ---- |
551 * We need to split the extent, and clear the bit
554 if (state->start <= end && state->end > end) {
556 prealloc = alloc_extent_state(GFP_ATOMIC);
557 err = split_state(tree, state, prealloc, end + 1);
558 BUG_ON(err == -EEXIST);
562 set |= clear_state_bit(tree, prealloc, &bits, wake);
568 if (state->end < end && prealloc && !need_resched())
569 next_node = rb_next(&state->rb_node);
573 set |= clear_state_bit(tree, state, &bits, wake);
574 if (last_end == (u64)-1)
576 start = last_end + 1;
577 if (start <= end && next_node) {
578 state = rb_entry(next_node, struct extent_state,
580 if (state->start == start)
586 spin_unlock(&tree->lock);
588 free_extent_state(prealloc);
595 spin_unlock(&tree->lock);
596 if (mask & __GFP_WAIT)
601 static int wait_on_state(struct extent_io_tree *tree,
602 struct extent_state *state)
603 __releases(tree->lock)
604 __acquires(tree->lock)
607 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
608 spin_unlock(&tree->lock);
610 spin_lock(&tree->lock);
611 finish_wait(&state->wq, &wait);
616 * waits for one or more bits to clear on a range in the state tree.
617 * The range [start, end] is inclusive.
618 * The tree lock is taken by this function
620 int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
622 struct extent_state *state;
623 struct rb_node *node;
625 spin_lock(&tree->lock);
629 * this search will find all the extents that end after
632 node = tree_search(tree, start);
636 state = rb_entry(node, struct extent_state, rb_node);
638 if (state->start > end)
641 if (state->state & bits) {
642 start = state->start;
643 atomic_inc(&state->refs);
644 wait_on_state(tree, state);
645 free_extent_state(state);
648 start = state->end + 1;
653 if (need_resched()) {
654 spin_unlock(&tree->lock);
656 spin_lock(&tree->lock);
660 spin_unlock(&tree->lock);
664 static int set_state_bits(struct extent_io_tree *tree,
665 struct extent_state *state,
669 int bits_to_set = *bits & ~EXTENT_CTLBITS;
671 ret = set_state_cb(tree, state, bits);
674 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
675 u64 range = state->end - state->start + 1;
676 tree->dirty_bytes += range;
678 state->state |= bits_to_set;
683 static void cache_state(struct extent_state *state,
684 struct extent_state **cached_ptr)
686 if (cached_ptr && !(*cached_ptr)) {
687 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
689 atomic_inc(&state->refs);
694 static void uncache_state(struct extent_state **cached_ptr)
696 if (cached_ptr && (*cached_ptr)) {
697 struct extent_state *state = *cached_ptr;
699 free_extent_state(state);
704 * set some bits on a range in the tree. This may require allocations or
705 * sleeping, so the gfp mask is used to indicate what is allowed.
707 * If any of the exclusive bits are set, this will fail with -EEXIST if some
708 * part of the range already has the desired bits set. The start of the
709 * existing range is returned in failed_start in this case.
711 * [start, end] is inclusive This takes the tree lock.
714 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
715 int bits, int exclusive_bits, u64 *failed_start,
716 struct extent_state **cached_state, gfp_t mask)
718 struct extent_state *state;
719 struct extent_state *prealloc = NULL;
720 struct rb_node *node;
725 bits |= EXTENT_FIRST_DELALLOC;
727 if (!prealloc && (mask & __GFP_WAIT)) {
728 prealloc = alloc_extent_state(mask);
733 spin_lock(&tree->lock);
734 if (cached_state && *cached_state) {
735 state = *cached_state;
736 if (state->start == start && state->tree) {
737 node = &state->rb_node;
742 * this search will find all the extents that end after
745 node = tree_search(tree, start);
747 err = insert_state(tree, prealloc, start, end, &bits);
749 BUG_ON(err == -EEXIST);
752 state = rb_entry(node, struct extent_state, rb_node);
754 last_start = state->start;
755 last_end = state->end;
758 * | ---- desired range ---- |
761 * Just lock what we found and keep going
763 if (state->start == start && state->end <= end) {
764 struct rb_node *next_node;
765 if (state->state & exclusive_bits) {
766 *failed_start = state->start;
771 err = set_state_bits(tree, state, &bits);
775 cache_state(state, cached_state);
776 merge_state(tree, state);
777 if (last_end == (u64)-1)
780 start = last_end + 1;
781 if (start < end && prealloc && !need_resched()) {
782 next_node = rb_next(node);
784 state = rb_entry(next_node, struct extent_state,
786 if (state->start == start)
794 * | ---- desired range ---- |
797 * | ------------- state -------------- |
799 * We need to split the extent we found, and may flip bits on
802 * If the extent we found extends past our
803 * range, we just split and search again. It'll get split
804 * again the next time though.
806 * If the extent we found is inside our range, we set the
809 if (state->start < start) {
810 if (state->state & exclusive_bits) {
811 *failed_start = start;
815 err = split_state(tree, state, prealloc, start);
816 BUG_ON(err == -EEXIST);
820 if (state->end <= end) {
821 err = set_state_bits(tree, state, &bits);
824 cache_state(state, cached_state);
825 merge_state(tree, state);
826 if (last_end == (u64)-1)
828 start = last_end + 1;
833 * | ---- desired range ---- |
834 * | state | or | state |
836 * There's a hole, we need to insert something in it and
837 * ignore the extent we found.
839 if (state->start > start) {
841 if (end < last_start)
844 this_end = last_start - 1;
845 err = insert_state(tree, prealloc, start, this_end,
847 BUG_ON(err == -EEXIST);
852 cache_state(prealloc, cached_state);
854 start = this_end + 1;
858 * | ---- desired range ---- |
860 * We need to split the extent, and set the bit
863 if (state->start <= end && state->end > end) {
864 if (state->state & exclusive_bits) {
865 *failed_start = start;
869 err = split_state(tree, state, prealloc, end + 1);
870 BUG_ON(err == -EEXIST);
872 err = set_state_bits(tree, prealloc, &bits);
877 cache_state(prealloc, cached_state);
878 merge_state(tree, prealloc);
886 spin_unlock(&tree->lock);
888 free_extent_state(prealloc);
895 spin_unlock(&tree->lock);
896 if (mask & __GFP_WAIT)
901 /* wrappers around set/clear extent bit */
902 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
905 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
909 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
910 int bits, gfp_t mask)
912 return set_extent_bit(tree, start, end, bits, 0, NULL,
916 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
917 int bits, gfp_t mask)
919 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
922 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
923 struct extent_state **cached_state, gfp_t mask)
925 return set_extent_bit(tree, start, end,
926 EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE,
927 0, NULL, cached_state, mask);
930 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
933 return clear_extent_bit(tree, start, end,
934 EXTENT_DIRTY | EXTENT_DELALLOC |
935 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
938 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
941 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
945 static int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
948 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0,
952 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
953 struct extent_state **cached_state, gfp_t mask)
955 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
956 NULL, cached_state, mask);
959 static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
960 u64 end, struct extent_state **cached_state,
963 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
967 int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
969 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
973 * either insert or lock state struct between start and end use mask to tell
974 * us if waiting is desired.
976 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
977 int bits, struct extent_state **cached_state, gfp_t mask)
982 err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
983 EXTENT_LOCKED, &failed_start,
985 if (err == -EEXIST && (mask & __GFP_WAIT)) {
986 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
987 start = failed_start;
991 WARN_ON(start > end);
996 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
998 return lock_extent_bits(tree, start, end, 0, NULL, mask);
1001 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
1007 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1008 &failed_start, NULL, mask);
1009 if (err == -EEXIST) {
1010 if (failed_start > start)
1011 clear_extent_bit(tree, start, failed_start - 1,
1012 EXTENT_LOCKED, 1, 0, NULL, mask);
1018 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1019 struct extent_state **cached, gfp_t mask)
1021 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1025 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
1027 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1032 * helper function to set pages and extents in the tree dirty
1034 int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
1036 unsigned long index = start >> PAGE_CACHE_SHIFT;
1037 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1040 while (index <= end_index) {
1041 page = find_get_page(tree->mapping, index);
1043 __set_page_dirty_nobuffers(page);
1044 page_cache_release(page);
1051 * helper function to set both pages and extents in the tree writeback
1053 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1055 unsigned long index = start >> PAGE_CACHE_SHIFT;
1056 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1059 while (index <= end_index) {
1060 page = find_get_page(tree->mapping, index);
1062 set_page_writeback(page);
1063 page_cache_release(page);
1070 * find the first offset in the io tree with 'bits' set. zero is
1071 * returned if we find something, and *start_ret and *end_ret are
1072 * set to reflect the state struct that was found.
1074 * If nothing was found, 1 is returned, < 0 on error
1076 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1077 u64 *start_ret, u64 *end_ret, int bits)
1079 struct rb_node *node;
1080 struct extent_state *state;
1083 spin_lock(&tree->lock);
1085 * this search will find all the extents that end after
1088 node = tree_search(tree, start);
1093 state = rb_entry(node, struct extent_state, rb_node);
1094 if (state->end >= start && (state->state & bits)) {
1095 *start_ret = state->start;
1096 *end_ret = state->end;
1100 node = rb_next(node);
1105 spin_unlock(&tree->lock);
1109 /* find the first state struct with 'bits' set after 'start', and
1110 * return it. tree->lock must be held. NULL will returned if
1111 * nothing was found after 'start'
1113 struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
1114 u64 start, int bits)
1116 struct rb_node *node;
1117 struct extent_state *state;
1120 * this search will find all the extents that end after
1123 node = tree_search(tree, start);
1128 state = rb_entry(node, struct extent_state, rb_node);
1129 if (state->end >= start && (state->state & bits))
1132 node = rb_next(node);
1141 * find a contiguous range of bytes in the file marked as delalloc, not
1142 * more than 'max_bytes'. start and end are used to return the range,
1144 * 1 is returned if we find something, 0 if nothing was in the tree
1146 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1147 u64 *start, u64 *end, u64 max_bytes,
1148 struct extent_state **cached_state)
1150 struct rb_node *node;
1151 struct extent_state *state;
1152 u64 cur_start = *start;
1154 u64 total_bytes = 0;
1156 spin_lock(&tree->lock);
1159 * this search will find all the extents that end after
1162 node = tree_search(tree, cur_start);
1170 state = rb_entry(node, struct extent_state, rb_node);
1171 if (found && (state->start != cur_start ||
1172 (state->state & EXTENT_BOUNDARY))) {
1175 if (!(state->state & EXTENT_DELALLOC)) {
1181 *start = state->start;
1182 *cached_state = state;
1183 atomic_inc(&state->refs);
1187 cur_start = state->end + 1;
1188 node = rb_next(node);
1191 total_bytes += state->end - state->start + 1;
1192 if (total_bytes >= max_bytes)
1196 spin_unlock(&tree->lock);
1200 static noinline int __unlock_for_delalloc(struct inode *inode,
1201 struct page *locked_page,
1205 struct page *pages[16];
1206 unsigned long index = start >> PAGE_CACHE_SHIFT;
1207 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1208 unsigned long nr_pages = end_index - index + 1;
1211 if (index == locked_page->index && end_index == index)
1214 while (nr_pages > 0) {
1215 ret = find_get_pages_contig(inode->i_mapping, index,
1216 min_t(unsigned long, nr_pages,
1217 ARRAY_SIZE(pages)), pages);
1218 for (i = 0; i < ret; i++) {
1219 if (pages[i] != locked_page)
1220 unlock_page(pages[i]);
1221 page_cache_release(pages[i]);
1230 static noinline int lock_delalloc_pages(struct inode *inode,
1231 struct page *locked_page,
1235 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1236 unsigned long start_index = index;
1237 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1238 unsigned long pages_locked = 0;
1239 struct page *pages[16];
1240 unsigned long nrpages;
1244 /* the caller is responsible for locking the start index */
1245 if (index == locked_page->index && index == end_index)
1248 /* skip the page at the start index */
1249 nrpages = end_index - index + 1;
1250 while (nrpages > 0) {
1251 ret = find_get_pages_contig(inode->i_mapping, index,
1252 min_t(unsigned long,
1253 nrpages, ARRAY_SIZE(pages)), pages);
1258 /* now we have an array of pages, lock them all */
1259 for (i = 0; i < ret; i++) {
1261 * the caller is taking responsibility for
1264 if (pages[i] != locked_page) {
1265 lock_page(pages[i]);
1266 if (!PageDirty(pages[i]) ||
1267 pages[i]->mapping != inode->i_mapping) {
1269 unlock_page(pages[i]);
1270 page_cache_release(pages[i]);
1274 page_cache_release(pages[i]);
1283 if (ret && pages_locked) {
1284 __unlock_for_delalloc(inode, locked_page,
1286 ((u64)(start_index + pages_locked - 1)) <<
1293 * find a contiguous range of bytes in the file marked as delalloc, not
1294 * more than 'max_bytes'. start and end are used to return the range,
1296 * 1 is returned if we find something, 0 if nothing was in the tree
1298 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1299 struct extent_io_tree *tree,
1300 struct page *locked_page,
1301 u64 *start, u64 *end,
1307 struct extent_state *cached_state = NULL;
1312 /* step one, find a bunch of delalloc bytes starting at start */
1313 delalloc_start = *start;
1315 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1316 max_bytes, &cached_state);
1317 if (!found || delalloc_end <= *start) {
1318 *start = delalloc_start;
1319 *end = delalloc_end;
1320 free_extent_state(cached_state);
1325 * start comes from the offset of locked_page. We have to lock
1326 * pages in order, so we can't process delalloc bytes before
1329 if (delalloc_start < *start)
1330 delalloc_start = *start;
1333 * make sure to limit the number of pages we try to lock down
1336 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1337 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1339 /* step two, lock all the pages after the page that has start */
1340 ret = lock_delalloc_pages(inode, locked_page,
1341 delalloc_start, delalloc_end);
1342 if (ret == -EAGAIN) {
1343 /* some of the pages are gone, lets avoid looping by
1344 * shortening the size of the delalloc range we're searching
1346 free_extent_state(cached_state);
1348 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1349 max_bytes = PAGE_CACHE_SIZE - offset;
1359 /* step three, lock the state bits for the whole range */
1360 lock_extent_bits(tree, delalloc_start, delalloc_end,
1361 0, &cached_state, GFP_NOFS);
1363 /* then test to make sure it is all still delalloc */
1364 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1365 EXTENT_DELALLOC, 1, cached_state);
1367 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1368 &cached_state, GFP_NOFS);
1369 __unlock_for_delalloc(inode, locked_page,
1370 delalloc_start, delalloc_end);
1374 free_extent_state(cached_state);
1375 *start = delalloc_start;
1376 *end = delalloc_end;
1381 int extent_clear_unlock_delalloc(struct inode *inode,
1382 struct extent_io_tree *tree,
1383 u64 start, u64 end, struct page *locked_page,
1387 struct page *pages[16];
1388 unsigned long index = start >> PAGE_CACHE_SHIFT;
1389 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1390 unsigned long nr_pages = end_index - index + 1;
1394 if (op & EXTENT_CLEAR_UNLOCK)
1395 clear_bits |= EXTENT_LOCKED;
1396 if (op & EXTENT_CLEAR_DIRTY)
1397 clear_bits |= EXTENT_DIRTY;
1399 if (op & EXTENT_CLEAR_DELALLOC)
1400 clear_bits |= EXTENT_DELALLOC;
1402 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1403 if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
1404 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
1405 EXTENT_SET_PRIVATE2)))
1408 while (nr_pages > 0) {
1409 ret = find_get_pages_contig(inode->i_mapping, index,
1410 min_t(unsigned long,
1411 nr_pages, ARRAY_SIZE(pages)), pages);
1412 for (i = 0; i < ret; i++) {
1414 if (op & EXTENT_SET_PRIVATE2)
1415 SetPagePrivate2(pages[i]);
1417 if (pages[i] == locked_page) {
1418 page_cache_release(pages[i]);
1421 if (op & EXTENT_CLEAR_DIRTY)
1422 clear_page_dirty_for_io(pages[i]);
1423 if (op & EXTENT_SET_WRITEBACK)
1424 set_page_writeback(pages[i]);
1425 if (op & EXTENT_END_WRITEBACK)
1426 end_page_writeback(pages[i]);
1427 if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1428 unlock_page(pages[i]);
1429 page_cache_release(pages[i]);
1439 * count the number of bytes in the tree that have a given bit(s)
1440 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1441 * cached. The total number found is returned.
1443 u64 count_range_bits(struct extent_io_tree *tree,
1444 u64 *start, u64 search_end, u64 max_bytes,
1445 unsigned long bits, int contig)
1447 struct rb_node *node;
1448 struct extent_state *state;
1449 u64 cur_start = *start;
1450 u64 total_bytes = 0;
1454 if (search_end <= cur_start) {
1459 spin_lock(&tree->lock);
1460 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1461 total_bytes = tree->dirty_bytes;
1465 * this search will find all the extents that end after
1468 node = tree_search(tree, cur_start);
1473 state = rb_entry(node, struct extent_state, rb_node);
1474 if (state->start > search_end)
1476 if (contig && found && state->start > last + 1)
1478 if (state->end >= cur_start && (state->state & bits) == bits) {
1479 total_bytes += min(search_end, state->end) + 1 -
1480 max(cur_start, state->start);
1481 if (total_bytes >= max_bytes)
1484 *start = state->start;
1488 } else if (contig && found) {
1491 node = rb_next(node);
1496 spin_unlock(&tree->lock);
1501 * set the private field for a given byte offset in the tree. If there isn't
1502 * an extent_state there already, this does nothing.
1504 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1506 struct rb_node *node;
1507 struct extent_state *state;
1510 spin_lock(&tree->lock);
1512 * this search will find all the extents that end after
1515 node = tree_search(tree, start);
1520 state = rb_entry(node, struct extent_state, rb_node);
1521 if (state->start != start) {
1525 state->private = private;
1527 spin_unlock(&tree->lock);
1531 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1533 struct rb_node *node;
1534 struct extent_state *state;
1537 spin_lock(&tree->lock);
1539 * this search will find all the extents that end after
1542 node = tree_search(tree, start);
1547 state = rb_entry(node, struct extent_state, rb_node);
1548 if (state->start != start) {
1552 *private = state->private;
1554 spin_unlock(&tree->lock);
1559 * searches a range in the state tree for a given mask.
1560 * If 'filled' == 1, this returns 1 only if every extent in the tree
1561 * has the bits set. Otherwise, 1 is returned if any bit in the
1562 * range is found set.
1564 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1565 int bits, int filled, struct extent_state *cached)
1567 struct extent_state *state = NULL;
1568 struct rb_node *node;
1571 spin_lock(&tree->lock);
1572 if (cached && cached->tree && cached->start == start)
1573 node = &cached->rb_node;
1575 node = tree_search(tree, start);
1576 while (node && start <= end) {
1577 state = rb_entry(node, struct extent_state, rb_node);
1579 if (filled && state->start > start) {
1584 if (state->start > end)
1587 if (state->state & bits) {
1591 } else if (filled) {
1596 if (state->end == (u64)-1)
1599 start = state->end + 1;
1602 node = rb_next(node);
1609 spin_unlock(&tree->lock);
1614 * helper function to set a given page up to date if all the
1615 * extents in the tree for that page are up to date
1617 static int check_page_uptodate(struct extent_io_tree *tree,
1620 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1621 u64 end = start + PAGE_CACHE_SIZE - 1;
1622 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1623 SetPageUptodate(page);
1628 * helper function to unlock a page if all the extents in the tree
1629 * for that page are unlocked
1631 static int check_page_locked(struct extent_io_tree *tree,
1634 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1635 u64 end = start + PAGE_CACHE_SIZE - 1;
1636 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1642 * helper function to end page writeback if all the extents
1643 * in the tree for that page are done with writeback
1645 static int check_page_writeback(struct extent_io_tree *tree,
1648 end_page_writeback(page);
1652 /* lots and lots of room for performance fixes in the end_bio funcs */
1655 * after a writepage IO is done, we need to:
1656 * clear the uptodate bits on error
1657 * clear the writeback bits in the extent tree for this IO
1658 * end_page_writeback if the page has no more pending IO
1660 * Scheduling is not allowed, so the extent state tree is expected
1661 * to have one and only one object corresponding to this IO.
1663 static void end_bio_extent_writepage(struct bio *bio, int err)
1665 int uptodate = err == 0;
1666 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1667 struct extent_io_tree *tree;
1674 struct page *page = bvec->bv_page;
1675 tree = &BTRFS_I(page->mapping->host)->io_tree;
1677 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1679 end = start + bvec->bv_len - 1;
1681 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1686 if (--bvec >= bio->bi_io_vec)
1687 prefetchw(&bvec->bv_page->flags);
1688 if (tree->ops && tree->ops->writepage_end_io_hook) {
1689 ret = tree->ops->writepage_end_io_hook(page, start,
1690 end, NULL, uptodate);
1695 if (!uptodate && tree->ops &&
1696 tree->ops->writepage_io_failed_hook) {
1697 ret = tree->ops->writepage_io_failed_hook(bio, page,
1700 uptodate = (err == 0);
1706 clear_extent_uptodate(tree, start, end, NULL, GFP_NOFS);
1707 ClearPageUptodate(page);
1712 end_page_writeback(page);
1714 check_page_writeback(tree, page);
1715 } while (bvec >= bio->bi_io_vec);
1721 * after a readpage IO is done, we need to:
1722 * clear the uptodate bits on error
1723 * set the uptodate bits if things worked
1724 * set the page up to date if all extents in the tree are uptodate
1725 * clear the lock bit in the extent tree
1726 * unlock the page if there are no other extents locked for it
1728 * Scheduling is not allowed, so the extent state tree is expected
1729 * to have one and only one object corresponding to this IO.
1731 static void end_bio_extent_readpage(struct bio *bio, int err)
1733 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1734 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
1735 struct bio_vec *bvec = bio->bi_io_vec;
1736 struct extent_io_tree *tree;
1746 struct page *page = bvec->bv_page;
1747 struct extent_state *cached = NULL;
1748 struct extent_state *state;
1750 tree = &BTRFS_I(page->mapping->host)->io_tree;
1752 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1754 end = start + bvec->bv_len - 1;
1756 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1761 if (++bvec <= bvec_end)
1762 prefetchw(&bvec->bv_page->flags);
1764 spin_lock(&tree->lock);
1765 state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
1766 if (state && state->start == start) {
1768 * take a reference on the state, unlock will drop
1771 cache_state(state, &cached);
1773 spin_unlock(&tree->lock);
1775 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
1776 ret = tree->ops->readpage_end_io_hook(page, start, end,
1781 if (!uptodate && tree->ops &&
1782 tree->ops->readpage_io_failed_hook) {
1783 ret = tree->ops->readpage_io_failed_hook(bio, page,
1787 test_bit(BIO_UPTODATE, &bio->bi_flags);
1790 uncache_state(&cached);
1796 set_extent_uptodate(tree, start, end, &cached,
1799 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
1803 SetPageUptodate(page);
1805 ClearPageUptodate(page);
1811 check_page_uptodate(tree, page);
1813 ClearPageUptodate(page);
1816 check_page_locked(tree, page);
1818 } while (bvec <= bvec_end);
1824 * IO done from prepare_write is pretty simple, we just unlock
1825 * the structs in the extent tree when done, and set the uptodate bits
1828 static void end_bio_extent_preparewrite(struct bio *bio, int err)
1830 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1831 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1832 struct extent_io_tree *tree;
1837 struct page *page = bvec->bv_page;
1838 struct extent_state *cached = NULL;
1839 tree = &BTRFS_I(page->mapping->host)->io_tree;
1841 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1843 end = start + bvec->bv_len - 1;
1845 if (--bvec >= bio->bi_io_vec)
1846 prefetchw(&bvec->bv_page->flags);
1849 set_extent_uptodate(tree, start, end, &cached,
1852 ClearPageUptodate(page);
1856 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
1858 } while (bvec >= bio->bi_io_vec);
1864 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
1869 bio = bio_alloc(gfp_flags, nr_vecs);
1871 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
1872 while (!bio && (nr_vecs /= 2))
1873 bio = bio_alloc(gfp_flags, nr_vecs);
1878 bio->bi_bdev = bdev;
1879 bio->bi_sector = first_sector;
1884 static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
1885 unsigned long bio_flags)
1888 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1889 struct page *page = bvec->bv_page;
1890 struct extent_io_tree *tree = bio->bi_private;
1893 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1895 bio->bi_private = NULL;
1899 if (tree->ops && tree->ops->submit_bio_hook)
1900 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
1901 mirror_num, bio_flags, start);
1903 submit_bio(rw, bio);
1904 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1910 static int submit_extent_page(int rw, struct extent_io_tree *tree,
1911 struct page *page, sector_t sector,
1912 size_t size, unsigned long offset,
1913 struct block_device *bdev,
1914 struct bio **bio_ret,
1915 unsigned long max_pages,
1916 bio_end_io_t end_io_func,
1918 unsigned long prev_bio_flags,
1919 unsigned long bio_flags)
1925 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
1926 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
1927 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
1929 if (bio_ret && *bio_ret) {
1932 contig = bio->bi_sector == sector;
1934 contig = bio->bi_sector + (bio->bi_size >> 9) ==
1937 if (prev_bio_flags != bio_flags || !contig ||
1938 (tree->ops && tree->ops->merge_bio_hook &&
1939 tree->ops->merge_bio_hook(page, offset, page_size, bio,
1941 bio_add_page(bio, page, page_size, offset) < page_size) {
1942 ret = submit_one_bio(rw, bio, mirror_num,
1949 if (this_compressed)
1952 nr = bio_get_nr_vecs(bdev);
1954 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
1958 bio_add_page(bio, page, page_size, offset);
1959 bio->bi_end_io = end_io_func;
1960 bio->bi_private = tree;
1965 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
1970 void set_page_extent_mapped(struct page *page)
1972 if (!PagePrivate(page)) {
1973 SetPagePrivate(page);
1974 page_cache_get(page);
1975 set_page_private(page, EXTENT_PAGE_PRIVATE);
1979 static void set_page_extent_head(struct page *page, unsigned long len)
1981 WARN_ON(!PagePrivate(page));
1982 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
1986 * basic readpage implementation. Locked extent state structs are inserted
1987 * into the tree that are removed when the IO is done (by the end_io
1990 static int __extent_read_full_page(struct extent_io_tree *tree,
1992 get_extent_t *get_extent,
1993 struct bio **bio, int mirror_num,
1994 unsigned long *bio_flags)
1996 struct inode *inode = page->mapping->host;
1997 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1998 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2002 u64 last_byte = i_size_read(inode);
2006 struct extent_map *em;
2007 struct block_device *bdev;
2008 struct btrfs_ordered_extent *ordered;
2011 size_t page_offset = 0;
2013 size_t disk_io_size;
2014 size_t blocksize = inode->i_sb->s_blocksize;
2015 unsigned long this_bio_flag = 0;
2017 set_page_extent_mapped(page);
2021 lock_extent(tree, start, end, GFP_NOFS);
2022 ordered = btrfs_lookup_ordered_extent(inode, start);
2025 unlock_extent(tree, start, end, GFP_NOFS);
2026 btrfs_start_ordered_extent(inode, ordered, 1);
2027 btrfs_put_ordered_extent(ordered);
2030 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2032 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2035 iosize = PAGE_CACHE_SIZE - zero_offset;
2036 userpage = kmap_atomic(page, KM_USER0);
2037 memset(userpage + zero_offset, 0, iosize);
2038 flush_dcache_page(page);
2039 kunmap_atomic(userpage, KM_USER0);
2042 while (cur <= end) {
2043 if (cur >= last_byte) {
2045 struct extent_state *cached = NULL;
2047 iosize = PAGE_CACHE_SIZE - page_offset;
2048 userpage = kmap_atomic(page, KM_USER0);
2049 memset(userpage + page_offset, 0, iosize);
2050 flush_dcache_page(page);
2051 kunmap_atomic(userpage, KM_USER0);
2052 set_extent_uptodate(tree, cur, cur + iosize - 1,
2054 unlock_extent_cached(tree, cur, cur + iosize - 1,
2058 em = get_extent(inode, page, page_offset, cur,
2060 if (IS_ERR(em) || !em) {
2062 unlock_extent(tree, cur, end, GFP_NOFS);
2065 extent_offset = cur - em->start;
2066 BUG_ON(extent_map_end(em) <= cur);
2069 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2070 this_bio_flag = EXTENT_BIO_COMPRESSED;
2071 extent_set_compress_type(&this_bio_flag,
2075 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2076 cur_end = min(extent_map_end(em) - 1, end);
2077 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2078 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2079 disk_io_size = em->block_len;
2080 sector = em->block_start >> 9;
2082 sector = (em->block_start + extent_offset) >> 9;
2083 disk_io_size = iosize;
2086 block_start = em->block_start;
2087 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2088 block_start = EXTENT_MAP_HOLE;
2089 free_extent_map(em);
2092 /* we've found a hole, just zero and go on */
2093 if (block_start == EXTENT_MAP_HOLE) {
2095 struct extent_state *cached = NULL;
2097 userpage = kmap_atomic(page, KM_USER0);
2098 memset(userpage + page_offset, 0, iosize);
2099 flush_dcache_page(page);
2100 kunmap_atomic(userpage, KM_USER0);
2102 set_extent_uptodate(tree, cur, cur + iosize - 1,
2104 unlock_extent_cached(tree, cur, cur + iosize - 1,
2107 page_offset += iosize;
2110 /* the get_extent function already copied into the page */
2111 if (test_range_bit(tree, cur, cur_end,
2112 EXTENT_UPTODATE, 1, NULL)) {
2113 check_page_uptodate(tree, page);
2114 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2116 page_offset += iosize;
2119 /* we have an inline extent but it didn't get marked up
2120 * to date. Error out
2122 if (block_start == EXTENT_MAP_INLINE) {
2124 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2126 page_offset += iosize;
2131 if (tree->ops && tree->ops->readpage_io_hook) {
2132 ret = tree->ops->readpage_io_hook(page, cur,
2136 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2138 ret = submit_extent_page(READ, tree, page,
2139 sector, disk_io_size, page_offset,
2141 end_bio_extent_readpage, mirror_num,
2145 *bio_flags = this_bio_flag;
2150 page_offset += iosize;
2153 if (!PageError(page))
2154 SetPageUptodate(page);
2160 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2161 get_extent_t *get_extent)
2163 struct bio *bio = NULL;
2164 unsigned long bio_flags = 0;
2167 ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
2170 ret = submit_one_bio(READ, bio, 0, bio_flags);
2174 static noinline void update_nr_written(struct page *page,
2175 struct writeback_control *wbc,
2176 unsigned long nr_written)
2178 wbc->nr_to_write -= nr_written;
2179 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2180 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2181 page->mapping->writeback_index = page->index + nr_written;
2185 * the writepage semantics are similar to regular writepage. extent
2186 * records are inserted to lock ranges in the tree, and as dirty areas
2187 * are found, they are marked writeback. Then the lock bits are removed
2188 * and the end_io handler clears the writeback ranges
2190 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2193 struct inode *inode = page->mapping->host;
2194 struct extent_page_data *epd = data;
2195 struct extent_io_tree *tree = epd->tree;
2196 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2198 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2202 u64 last_byte = i_size_read(inode);
2206 struct extent_state *cached_state = NULL;
2207 struct extent_map *em;
2208 struct block_device *bdev;
2211 size_t pg_offset = 0;
2213 loff_t i_size = i_size_read(inode);
2214 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2220 unsigned long nr_written = 0;
2222 if (wbc->sync_mode == WB_SYNC_ALL)
2223 write_flags = WRITE_SYNC;
2225 write_flags = WRITE;
2227 trace___extent_writepage(page, inode, wbc);
2229 WARN_ON(!PageLocked(page));
2230 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2231 if (page->index > end_index ||
2232 (page->index == end_index && !pg_offset)) {
2233 page->mapping->a_ops->invalidatepage(page, 0);
2238 if (page->index == end_index) {
2241 userpage = kmap_atomic(page, KM_USER0);
2242 memset(userpage + pg_offset, 0,
2243 PAGE_CACHE_SIZE - pg_offset);
2244 kunmap_atomic(userpage, KM_USER0);
2245 flush_dcache_page(page);
2249 set_page_extent_mapped(page);
2251 delalloc_start = start;
2254 if (!epd->extent_locked) {
2255 u64 delalloc_to_write = 0;
2257 * make sure the wbc mapping index is at least updated
2260 update_nr_written(page, wbc, 0);
2262 while (delalloc_end < page_end) {
2263 nr_delalloc = find_lock_delalloc_range(inode, tree,
2268 if (nr_delalloc == 0) {
2269 delalloc_start = delalloc_end + 1;
2272 tree->ops->fill_delalloc(inode, page, delalloc_start,
2273 delalloc_end, &page_started,
2276 * delalloc_end is already one less than the total
2277 * length, so we don't subtract one from
2280 delalloc_to_write += (delalloc_end - delalloc_start +
2283 delalloc_start = delalloc_end + 1;
2285 if (wbc->nr_to_write < delalloc_to_write) {
2288 if (delalloc_to_write < thresh * 2)
2289 thresh = delalloc_to_write;
2290 wbc->nr_to_write = min_t(u64, delalloc_to_write,
2294 /* did the fill delalloc function already unlock and start
2300 * we've unlocked the page, so we can't update
2301 * the mapping's writeback index, just update
2304 wbc->nr_to_write -= nr_written;
2308 if (tree->ops && tree->ops->writepage_start_hook) {
2309 ret = tree->ops->writepage_start_hook(page, start,
2311 if (ret == -EAGAIN) {
2312 redirty_page_for_writepage(wbc, page);
2313 update_nr_written(page, wbc, nr_written);
2321 * we don't want to touch the inode after unlocking the page,
2322 * so we update the mapping writeback index now
2324 update_nr_written(page, wbc, nr_written + 1);
2327 if (last_byte <= start) {
2328 if (tree->ops && tree->ops->writepage_end_io_hook)
2329 tree->ops->writepage_end_io_hook(page, start,
2334 blocksize = inode->i_sb->s_blocksize;
2336 while (cur <= end) {
2337 if (cur >= last_byte) {
2338 if (tree->ops && tree->ops->writepage_end_io_hook)
2339 tree->ops->writepage_end_io_hook(page, cur,
2343 em = epd->get_extent(inode, page, pg_offset, cur,
2345 if (IS_ERR(em) || !em) {
2350 extent_offset = cur - em->start;
2351 BUG_ON(extent_map_end(em) <= cur);
2353 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2354 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2355 sector = (em->block_start + extent_offset) >> 9;
2357 block_start = em->block_start;
2358 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2359 free_extent_map(em);
2363 * compressed and inline extents are written through other
2366 if (compressed || block_start == EXTENT_MAP_HOLE ||
2367 block_start == EXTENT_MAP_INLINE) {
2369 * end_io notification does not happen here for
2370 * compressed extents
2372 if (!compressed && tree->ops &&
2373 tree->ops->writepage_end_io_hook)
2374 tree->ops->writepage_end_io_hook(page, cur,
2377 else if (compressed) {
2378 /* we don't want to end_page_writeback on
2379 * a compressed extent. this happens
2386 pg_offset += iosize;
2389 /* leave this out until we have a page_mkwrite call */
2390 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2391 EXTENT_DIRTY, 0, NULL)) {
2393 pg_offset += iosize;
2397 if (tree->ops && tree->ops->writepage_io_hook) {
2398 ret = tree->ops->writepage_io_hook(page, cur,
2406 unsigned long max_nr = end_index + 1;
2408 set_range_writeback(tree, cur, cur + iosize - 1);
2409 if (!PageWriteback(page)) {
2410 printk(KERN_ERR "btrfs warning page %lu not "
2411 "writeback, cur %llu end %llu\n",
2412 page->index, (unsigned long long)cur,
2413 (unsigned long long)end);
2416 ret = submit_extent_page(write_flags, tree, page,
2417 sector, iosize, pg_offset,
2418 bdev, &epd->bio, max_nr,
2419 end_bio_extent_writepage,
2425 pg_offset += iosize;
2430 /* make sure the mapping tag for page dirty gets cleared */
2431 set_page_writeback(page);
2432 end_page_writeback(page);
2438 /* drop our reference on any cached states */
2439 free_extent_state(cached_state);
2444 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2445 * @mapping: address space structure to write
2446 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2447 * @writepage: function called for each page
2448 * @data: data passed to writepage function
2450 * If a page is already under I/O, write_cache_pages() skips it, even
2451 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2452 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2453 * and msync() need to guarantee that all the data which was dirty at the time
2454 * the call was made get new I/O started against them. If wbc->sync_mode is
2455 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2456 * existing IO to complete.
2458 static int extent_write_cache_pages(struct extent_io_tree *tree,
2459 struct address_space *mapping,
2460 struct writeback_control *wbc,
2461 writepage_t writepage, void *data,
2462 void (*flush_fn)(void *))
2466 int nr_to_write_done = 0;
2467 struct pagevec pvec;
2470 pgoff_t end; /* Inclusive */
2473 pagevec_init(&pvec, 0);
2474 if (wbc->range_cyclic) {
2475 index = mapping->writeback_index; /* Start from prev offset */
2478 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2479 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2483 while (!done && !nr_to_write_done && (index <= end) &&
2484 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
2485 PAGECACHE_TAG_DIRTY, min(end - index,
2486 (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
2490 for (i = 0; i < nr_pages; i++) {
2491 struct page *page = pvec.pages[i];
2494 * At this point we hold neither mapping->tree_lock nor
2495 * lock on the page itself: the page may be truncated or
2496 * invalidated (changing page->mapping to NULL), or even
2497 * swizzled back from swapper_space to tmpfs file
2500 if (tree->ops && tree->ops->write_cache_pages_lock_hook)
2501 tree->ops->write_cache_pages_lock_hook(page);
2505 if (unlikely(page->mapping != mapping)) {
2510 if (!wbc->range_cyclic && page->index > end) {
2516 if (wbc->sync_mode != WB_SYNC_NONE) {
2517 if (PageWriteback(page))
2519 wait_on_page_writeback(page);
2522 if (PageWriteback(page) ||
2523 !clear_page_dirty_for_io(page)) {
2528 ret = (*writepage)(page, wbc, data);
2530 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
2538 * the filesystem may choose to bump up nr_to_write.
2539 * We have to make sure to honor the new nr_to_write
2542 nr_to_write_done = wbc->nr_to_write <= 0;
2544 pagevec_release(&pvec);
2547 if (!scanned && !done) {
2549 * We hit the last page and there is more work to be done: wrap
2550 * back to the start of the file
2559 static void flush_epd_write_bio(struct extent_page_data *epd)
2563 submit_one_bio(WRITE_SYNC, epd->bio, 0, 0);
2565 submit_one_bio(WRITE, epd->bio, 0, 0);
2570 static noinline void flush_write_bio(void *data)
2572 struct extent_page_data *epd = data;
2573 flush_epd_write_bio(epd);
2576 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
2577 get_extent_t *get_extent,
2578 struct writeback_control *wbc)
2581 struct address_space *mapping = page->mapping;
2582 struct extent_page_data epd = {
2585 .get_extent = get_extent,
2587 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
2589 struct writeback_control wbc_writepages = {
2590 .sync_mode = wbc->sync_mode,
2591 .older_than_this = NULL,
2593 .range_start = page_offset(page) + PAGE_CACHE_SIZE,
2594 .range_end = (loff_t)-1,
2597 ret = __extent_writepage(page, wbc, &epd);
2599 extent_write_cache_pages(tree, mapping, &wbc_writepages,
2600 __extent_writepage, &epd, flush_write_bio);
2601 flush_epd_write_bio(&epd);
2605 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
2606 u64 start, u64 end, get_extent_t *get_extent,
2610 struct address_space *mapping = inode->i_mapping;
2612 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
2615 struct extent_page_data epd = {
2618 .get_extent = get_extent,
2620 .sync_io = mode == WB_SYNC_ALL,
2622 struct writeback_control wbc_writepages = {
2624 .older_than_this = NULL,
2625 .nr_to_write = nr_pages * 2,
2626 .range_start = start,
2627 .range_end = end + 1,
2630 while (start <= end) {
2631 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
2632 if (clear_page_dirty_for_io(page))
2633 ret = __extent_writepage(page, &wbc_writepages, &epd);
2635 if (tree->ops && tree->ops->writepage_end_io_hook)
2636 tree->ops->writepage_end_io_hook(page, start,
2637 start + PAGE_CACHE_SIZE - 1,
2641 page_cache_release(page);
2642 start += PAGE_CACHE_SIZE;
2645 flush_epd_write_bio(&epd);
2649 int extent_writepages(struct extent_io_tree *tree,
2650 struct address_space *mapping,
2651 get_extent_t *get_extent,
2652 struct writeback_control *wbc)
2655 struct extent_page_data epd = {
2658 .get_extent = get_extent,
2660 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
2663 ret = extent_write_cache_pages(tree, mapping, wbc,
2664 __extent_writepage, &epd,
2666 flush_epd_write_bio(&epd);
2670 int extent_readpages(struct extent_io_tree *tree,
2671 struct address_space *mapping,
2672 struct list_head *pages, unsigned nr_pages,
2673 get_extent_t get_extent)
2675 struct bio *bio = NULL;
2677 unsigned long bio_flags = 0;
2679 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
2680 struct page *page = list_entry(pages->prev, struct page, lru);
2682 prefetchw(&page->flags);
2683 list_del(&page->lru);
2684 if (!add_to_page_cache_lru(page, mapping,
2685 page->index, GFP_NOFS)) {
2686 __extent_read_full_page(tree, page, get_extent,
2687 &bio, 0, &bio_flags);
2689 page_cache_release(page);
2691 BUG_ON(!list_empty(pages));
2693 submit_one_bio(READ, bio, 0, bio_flags);
2698 * basic invalidatepage code, this waits on any locked or writeback
2699 * ranges corresponding to the page, and then deletes any extent state
2700 * records from the tree
2702 int extent_invalidatepage(struct extent_io_tree *tree,
2703 struct page *page, unsigned long offset)
2705 struct extent_state *cached_state = NULL;
2706 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
2707 u64 end = start + PAGE_CACHE_SIZE - 1;
2708 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
2710 start += (offset + blocksize - 1) & ~(blocksize - 1);
2714 lock_extent_bits(tree, start, end, 0, &cached_state, GFP_NOFS);
2715 wait_on_page_writeback(page);
2716 clear_extent_bit(tree, start, end,
2717 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
2718 EXTENT_DO_ACCOUNTING,
2719 1, 1, &cached_state, GFP_NOFS);
2724 * simple commit_write call, set_range_dirty is used to mark both
2725 * the pages and the extent records as dirty
2727 int extent_commit_write(struct extent_io_tree *tree,
2728 struct inode *inode, struct page *page,
2729 unsigned from, unsigned to)
2731 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
2733 set_page_extent_mapped(page);
2734 set_page_dirty(page);
2736 if (pos > inode->i_size) {
2737 i_size_write(inode, pos);
2738 mark_inode_dirty(inode);
2743 int extent_prepare_write(struct extent_io_tree *tree,
2744 struct inode *inode, struct page *page,
2745 unsigned from, unsigned to, get_extent_t *get_extent)
2747 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2748 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
2750 u64 orig_block_start;
2753 struct extent_map *em;
2754 unsigned blocksize = 1 << inode->i_blkbits;
2755 size_t page_offset = 0;
2756 size_t block_off_start;
2757 size_t block_off_end;
2763 set_page_extent_mapped(page);
2765 block_start = (page_start + from) & ~((u64)blocksize - 1);
2766 block_end = (page_start + to - 1) | (blocksize - 1);
2767 orig_block_start = block_start;
2769 lock_extent(tree, page_start, page_end, GFP_NOFS);
2770 while (block_start <= block_end) {
2771 em = get_extent(inode, page, page_offset, block_start,
2772 block_end - block_start + 1, 1);
2773 if (IS_ERR(em) || !em)
2776 cur_end = min(block_end, extent_map_end(em) - 1);
2777 block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
2778 block_off_end = block_off_start + blocksize;
2779 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
2781 if (!PageUptodate(page) && isnew &&
2782 (block_off_end > to || block_off_start < from)) {
2785 kaddr = kmap_atomic(page, KM_USER0);
2786 if (block_off_end > to)
2787 memset(kaddr + to, 0, block_off_end - to);
2788 if (block_off_start < from)
2789 memset(kaddr + block_off_start, 0,
2790 from - block_off_start);
2791 flush_dcache_page(page);
2792 kunmap_atomic(kaddr, KM_USER0);
2794 if ((em->block_start != EXTENT_MAP_HOLE &&
2795 em->block_start != EXTENT_MAP_INLINE) &&
2796 !isnew && !PageUptodate(page) &&
2797 (block_off_end > to || block_off_start < from) &&
2798 !test_range_bit(tree, block_start, cur_end,
2799 EXTENT_UPTODATE, 1, NULL)) {
2801 u64 extent_offset = block_start - em->start;
2803 sector = (em->block_start + extent_offset) >> 9;
2804 iosize = (cur_end - block_start + blocksize) &
2805 ~((u64)blocksize - 1);
2807 * we've already got the extent locked, but we
2808 * need to split the state such that our end_bio
2809 * handler can clear the lock.
2811 set_extent_bit(tree, block_start,
2812 block_start + iosize - 1,
2813 EXTENT_LOCKED, 0, NULL, NULL, GFP_NOFS);
2814 ret = submit_extent_page(READ, tree, page,
2815 sector, iosize, page_offset, em->bdev,
2817 end_bio_extent_preparewrite, 0,
2822 block_start = block_start + iosize;
2824 struct extent_state *cached = NULL;
2826 set_extent_uptodate(tree, block_start, cur_end, &cached,
2828 unlock_extent_cached(tree, block_start, cur_end,
2830 block_start = cur_end + 1;
2832 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
2833 free_extent_map(em);
2836 wait_extent_bit(tree, orig_block_start,
2837 block_end, EXTENT_LOCKED);
2839 check_page_uptodate(tree, page);
2841 /* FIXME, zero out newly allocated blocks on error */
2846 * a helper for releasepage, this tests for areas of the page that
2847 * are locked or under IO and drops the related state bits if it is safe
2850 int try_release_extent_state(struct extent_map_tree *map,
2851 struct extent_io_tree *tree, struct page *page,
2854 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2855 u64 end = start + PAGE_CACHE_SIZE - 1;
2858 if (test_range_bit(tree, start, end,
2859 EXTENT_IOBITS, 0, NULL))
2862 if ((mask & GFP_NOFS) == GFP_NOFS)
2865 * at this point we can safely clear everything except the
2866 * locked bit and the nodatasum bit
2868 ret = clear_extent_bit(tree, start, end,
2869 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
2872 /* if clear_extent_bit failed for enomem reasons,
2873 * we can't allow the release to continue.
2884 * a helper for releasepage. As long as there are no locked extents
2885 * in the range corresponding to the page, both state records and extent
2886 * map records are removed
2888 int try_release_extent_mapping(struct extent_map_tree *map,
2889 struct extent_io_tree *tree, struct page *page,
2892 struct extent_map *em;
2893 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2894 u64 end = start + PAGE_CACHE_SIZE - 1;
2896 if ((mask & __GFP_WAIT) &&
2897 page->mapping->host->i_size > 16 * 1024 * 1024) {
2899 while (start <= end) {
2900 len = end - start + 1;
2901 write_lock(&map->lock);
2902 em = lookup_extent_mapping(map, start, len);
2903 if (!em || IS_ERR(em)) {
2904 write_unlock(&map->lock);
2907 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
2908 em->start != start) {
2909 write_unlock(&map->lock);
2910 free_extent_map(em);
2913 if (!test_range_bit(tree, em->start,
2914 extent_map_end(em) - 1,
2915 EXTENT_LOCKED | EXTENT_WRITEBACK,
2917 remove_extent_mapping(map, em);
2918 /* once for the rb tree */
2919 free_extent_map(em);
2921 start = extent_map_end(em);
2922 write_unlock(&map->lock);
2925 free_extent_map(em);
2928 return try_release_extent_state(map, tree, page, mask);
2931 sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
2932 get_extent_t *get_extent)
2934 struct inode *inode = mapping->host;
2935 struct extent_state *cached_state = NULL;
2936 u64 start = iblock << inode->i_blkbits;
2937 sector_t sector = 0;
2938 size_t blksize = (1 << inode->i_blkbits);
2939 struct extent_map *em;
2941 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
2942 0, &cached_state, GFP_NOFS);
2943 em = get_extent(inode, NULL, 0, start, blksize, 0);
2944 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start,
2945 start + blksize - 1, &cached_state, GFP_NOFS);
2946 if (!em || IS_ERR(em))
2949 if (em->block_start > EXTENT_MAP_LAST_BYTE)
2952 sector = (em->block_start + start - em->start) >> inode->i_blkbits;
2954 free_extent_map(em);
2959 * helper function for fiemap, which doesn't want to see any holes.
2960 * This maps until we find something past 'last'
2962 static struct extent_map *get_extent_skip_holes(struct inode *inode,
2965 get_extent_t *get_extent)
2967 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
2968 struct extent_map *em;
2975 len = last - offset;
2978 len = (len + sectorsize - 1) & ~(sectorsize - 1);
2979 em = get_extent(inode, NULL, 0, offset, len, 0);
2980 if (!em || IS_ERR(em))
2983 /* if this isn't a hole return it */
2984 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
2985 em->block_start != EXTENT_MAP_HOLE) {
2989 /* this is a hole, advance to the next extent */
2990 offset = extent_map_end(em);
2991 free_extent_map(em);
2998 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2999 __u64 start, __u64 len, get_extent_t *get_extent)
3003 u64 max = start + len;
3007 u64 last_for_get_extent = 0;
3009 u64 isize = i_size_read(inode);
3010 struct btrfs_key found_key;
3011 struct extent_map *em = NULL;
3012 struct extent_state *cached_state = NULL;
3013 struct btrfs_path *path;
3014 struct btrfs_file_extent_item *item;
3019 unsigned long emflags;
3024 path = btrfs_alloc_path();
3027 path->leave_spinning = 1;
3030 * lookup the last file extent. We're not using i_size here
3031 * because there might be preallocation past i_size
3033 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
3034 path, inode->i_ino, -1, 0);
3036 btrfs_free_path(path);
3041 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3042 struct btrfs_file_extent_item);
3043 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
3044 found_type = btrfs_key_type(&found_key);
3046 /* No extents, but there might be delalloc bits */
3047 if (found_key.objectid != inode->i_ino ||
3048 found_type != BTRFS_EXTENT_DATA_KEY) {
3049 /* have to trust i_size as the end */
3051 last_for_get_extent = isize;
3054 * remember the start of the last extent. There are a
3055 * bunch of different factors that go into the length of the
3056 * extent, so its much less complex to remember where it started
3058 last = found_key.offset;
3059 last_for_get_extent = last + 1;
3061 btrfs_free_path(path);
3064 * we might have some extents allocated but more delalloc past those
3065 * extents. so, we trust isize unless the start of the last extent is
3070 last_for_get_extent = isize;
3073 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
3074 &cached_state, GFP_NOFS);
3076 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3086 u64 offset_in_extent;
3088 /* break if the extent we found is outside the range */
3089 if (em->start >= max || extent_map_end(em) < off)
3093 * get_extent may return an extent that starts before our
3094 * requested range. We have to make sure the ranges
3095 * we return to fiemap always move forward and don't
3096 * overlap, so adjust the offsets here
3098 em_start = max(em->start, off);
3101 * record the offset from the start of the extent
3102 * for adjusting the disk offset below
3104 offset_in_extent = em_start - em->start;
3105 em_end = extent_map_end(em);
3106 em_len = em_end - em_start;
3107 emflags = em->flags;
3112 * bump off for our next call to get_extent
3114 off = extent_map_end(em);
3118 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
3120 flags |= FIEMAP_EXTENT_LAST;
3121 } else if (em->block_start == EXTENT_MAP_INLINE) {
3122 flags |= (FIEMAP_EXTENT_DATA_INLINE |
3123 FIEMAP_EXTENT_NOT_ALIGNED);
3124 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
3125 flags |= (FIEMAP_EXTENT_DELALLOC |
3126 FIEMAP_EXTENT_UNKNOWN);
3128 disko = em->block_start + offset_in_extent;
3130 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
3131 flags |= FIEMAP_EXTENT_ENCODED;
3133 free_extent_map(em);
3135 if ((em_start >= last) || em_len == (u64)-1 ||
3136 (last == (u64)-1 && isize <= em_end)) {
3137 flags |= FIEMAP_EXTENT_LAST;
3141 /* now scan forward to see if this is really the last extent. */
3142 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3149 flags |= FIEMAP_EXTENT_LAST;
3152 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
3158 free_extent_map(em);
3160 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
3161 &cached_state, GFP_NOFS);
3165 static inline struct page *extent_buffer_page(struct extent_buffer *eb,
3169 struct address_space *mapping;
3172 return eb->first_page;
3173 i += eb->start >> PAGE_CACHE_SHIFT;
3174 mapping = eb->first_page->mapping;
3179 * extent_buffer_page is only called after pinning the page
3180 * by increasing the reference count. So we know the page must
3181 * be in the radix tree.
3184 p = radix_tree_lookup(&mapping->page_tree, i);
3190 static inline unsigned long num_extent_pages(u64 start, u64 len)
3192 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
3193 (start >> PAGE_CACHE_SHIFT);
3196 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
3201 struct extent_buffer *eb = NULL;
3203 unsigned long flags;
3206 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
3211 spin_lock_init(&eb->lock);
3212 init_waitqueue_head(&eb->lock_wq);
3215 spin_lock_irqsave(&leak_lock, flags);
3216 list_add(&eb->leak_list, &buffers);
3217 spin_unlock_irqrestore(&leak_lock, flags);
3219 atomic_set(&eb->refs, 1);
3224 static void __free_extent_buffer(struct extent_buffer *eb)
3227 unsigned long flags;
3228 spin_lock_irqsave(&leak_lock, flags);
3229 list_del(&eb->leak_list);
3230 spin_unlock_irqrestore(&leak_lock, flags);
3232 kmem_cache_free(extent_buffer_cache, eb);
3236 * Helper for releasing extent buffer page.
3238 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
3239 unsigned long start_idx)
3241 unsigned long index;
3244 if (!eb->first_page)
3247 index = num_extent_pages(eb->start, eb->len);
3248 if (start_idx >= index)
3253 page = extent_buffer_page(eb, index);
3255 page_cache_release(page);
3256 } while (index != start_idx);
3260 * Helper for releasing the extent buffer.
3262 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
3264 btrfs_release_extent_buffer_page(eb, 0);
3265 __free_extent_buffer(eb);
3268 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
3269 u64 start, unsigned long len,
3273 unsigned long num_pages = num_extent_pages(start, len);
3275 unsigned long index = start >> PAGE_CACHE_SHIFT;
3276 struct extent_buffer *eb;
3277 struct extent_buffer *exists = NULL;
3279 struct address_space *mapping = tree->mapping;
3284 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3285 if (eb && atomic_inc_not_zero(&eb->refs)) {
3287 mark_page_accessed(eb->first_page);
3292 eb = __alloc_extent_buffer(tree, start, len, mask);
3297 eb->first_page = page0;
3300 page_cache_get(page0);
3301 mark_page_accessed(page0);
3302 set_page_extent_mapped(page0);
3303 set_page_extent_head(page0, len);
3304 uptodate = PageUptodate(page0);
3308 for (; i < num_pages; i++, index++) {
3309 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
3314 set_page_extent_mapped(p);
3315 mark_page_accessed(p);
3318 set_page_extent_head(p, len);
3320 set_page_private(p, EXTENT_PAGE_PRIVATE);
3322 if (!PageUptodate(p))
3326 * see below about how we avoid a nasty race with release page
3327 * and why we unlock later
3333 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3335 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
3339 spin_lock(&tree->buffer_lock);
3340 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
3341 if (ret == -EEXIST) {
3342 exists = radix_tree_lookup(&tree->buffer,
3343 start >> PAGE_CACHE_SHIFT);
3344 /* add one reference for the caller */
3345 atomic_inc(&exists->refs);
3346 spin_unlock(&tree->buffer_lock);
3347 radix_tree_preload_end();
3350 /* add one reference for the tree */
3351 atomic_inc(&eb->refs);
3352 spin_unlock(&tree->buffer_lock);
3353 radix_tree_preload_end();
3356 * there is a race where release page may have
3357 * tried to find this extent buffer in the radix
3358 * but failed. It will tell the VM it is safe to
3359 * reclaim the, and it will clear the page private bit.
3360 * We must make sure to set the page private bit properly
3361 * after the extent buffer is in the radix tree so
3362 * it doesn't get lost
3364 set_page_extent_mapped(eb->first_page);
3365 set_page_extent_head(eb->first_page, eb->len);
3367 unlock_page(eb->first_page);
3371 if (eb->first_page && !page0)
3372 unlock_page(eb->first_page);
3374 if (!atomic_dec_and_test(&eb->refs))
3376 btrfs_release_extent_buffer(eb);
3380 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
3381 u64 start, unsigned long len,
3384 struct extent_buffer *eb;
3387 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3388 if (eb && atomic_inc_not_zero(&eb->refs)) {
3390 mark_page_accessed(eb->first_page);
3398 void free_extent_buffer(struct extent_buffer *eb)
3403 if (!atomic_dec_and_test(&eb->refs))
3409 int clear_extent_buffer_dirty(struct extent_io_tree *tree,
3410 struct extent_buffer *eb)
3413 unsigned long num_pages;
3416 num_pages = num_extent_pages(eb->start, eb->len);
3418 for (i = 0; i < num_pages; i++) {
3419 page = extent_buffer_page(eb, i);
3420 if (!PageDirty(page))
3424 WARN_ON(!PagePrivate(page));
3426 set_page_extent_mapped(page);
3428 set_page_extent_head(page, eb->len);
3430 clear_page_dirty_for_io(page);
3431 spin_lock_irq(&page->mapping->tree_lock);
3432 if (!PageDirty(page)) {
3433 radix_tree_tag_clear(&page->mapping->page_tree,
3435 PAGECACHE_TAG_DIRTY);
3437 spin_unlock_irq(&page->mapping->tree_lock);
3443 int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
3444 struct extent_buffer *eb)
3446 return wait_on_extent_writeback(tree, eb->start,
3447 eb->start + eb->len - 1);
3450 int set_extent_buffer_dirty(struct extent_io_tree *tree,
3451 struct extent_buffer *eb)
3454 unsigned long num_pages;
3457 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3458 num_pages = num_extent_pages(eb->start, eb->len);
3459 for (i = 0; i < num_pages; i++)
3460 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
3464 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
3465 struct extent_buffer *eb,
3466 struct extent_state **cached_state)
3470 unsigned long num_pages;
3472 num_pages = num_extent_pages(eb->start, eb->len);
3473 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3475 clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3476 cached_state, GFP_NOFS);
3477 for (i = 0; i < num_pages; i++) {
3478 page = extent_buffer_page(eb, i);
3480 ClearPageUptodate(page);
3485 int set_extent_buffer_uptodate(struct extent_io_tree *tree,
3486 struct extent_buffer *eb)
3490 unsigned long num_pages;
3492 num_pages = num_extent_pages(eb->start, eb->len);
3494 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3496 for (i = 0; i < num_pages; i++) {
3497 page = extent_buffer_page(eb, i);
3498 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
3499 ((i == num_pages - 1) &&
3500 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
3501 check_page_uptodate(tree, page);
3504 SetPageUptodate(page);
3509 int extent_range_uptodate(struct extent_io_tree *tree,
3514 int pg_uptodate = 1;
3516 unsigned long index;
3518 ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL);
3521 while (start <= end) {
3522 index = start >> PAGE_CACHE_SHIFT;
3523 page = find_get_page(tree->mapping, index);
3524 uptodate = PageUptodate(page);
3525 page_cache_release(page);
3530 start += PAGE_CACHE_SIZE;
3535 int extent_buffer_uptodate(struct extent_io_tree *tree,
3536 struct extent_buffer *eb,
3537 struct extent_state *cached_state)
3540 unsigned long num_pages;
3543 int pg_uptodate = 1;
3545 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3548 ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3549 EXTENT_UPTODATE, 1, cached_state);
3553 num_pages = num_extent_pages(eb->start, eb->len);
3554 for (i = 0; i < num_pages; i++) {
3555 page = extent_buffer_page(eb, i);
3556 if (!PageUptodate(page)) {
3564 int read_extent_buffer_pages(struct extent_io_tree *tree,
3565 struct extent_buffer *eb,
3566 u64 start, int wait,
3567 get_extent_t *get_extent, int mirror_num)
3570 unsigned long start_i;
3574 int locked_pages = 0;
3575 int all_uptodate = 1;
3576 int inc_all_pages = 0;
3577 unsigned long num_pages;
3578 struct bio *bio = NULL;
3579 unsigned long bio_flags = 0;
3581 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3584 if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3585 EXTENT_UPTODATE, 1, NULL)) {
3590 WARN_ON(start < eb->start);
3591 start_i = (start >> PAGE_CACHE_SHIFT) -
3592 (eb->start >> PAGE_CACHE_SHIFT);
3597 num_pages = num_extent_pages(eb->start, eb->len);
3598 for (i = start_i; i < num_pages; i++) {
3599 page = extent_buffer_page(eb, i);
3601 if (!trylock_page(page))
3607 if (!PageUptodate(page))
3612 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3616 for (i = start_i; i < num_pages; i++) {
3617 page = extent_buffer_page(eb, i);
3619 WARN_ON(!PagePrivate(page));
3621 set_page_extent_mapped(page);
3623 set_page_extent_head(page, eb->len);
3626 page_cache_get(page);
3627 if (!PageUptodate(page)) {
3630 ClearPageError(page);
3631 err = __extent_read_full_page(tree, page,
3633 mirror_num, &bio_flags);
3642 submit_one_bio(READ, bio, mirror_num, bio_flags);
3647 for (i = start_i; i < num_pages; i++) {
3648 page = extent_buffer_page(eb, i);
3649 wait_on_page_locked(page);
3650 if (!PageUptodate(page))
3655 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3660 while (locked_pages > 0) {
3661 page = extent_buffer_page(eb, i);
3669 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
3670 unsigned long start,
3677 char *dst = (char *)dstv;
3678 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3679 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3681 WARN_ON(start > eb->len);
3682 WARN_ON(start + len > eb->start + eb->len);
3684 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3687 page = extent_buffer_page(eb, i);
3689 cur = min(len, (PAGE_CACHE_SIZE - offset));
3690 kaddr = kmap_atomic(page, KM_USER1);
3691 memcpy(dst, kaddr + offset, cur);
3692 kunmap_atomic(kaddr, KM_USER1);
3701 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
3702 unsigned long min_len, char **token, char **map,
3703 unsigned long *map_start,
3704 unsigned long *map_len, int km)
3706 size_t offset = start & (PAGE_CACHE_SIZE - 1);
3709 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3710 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3711 unsigned long end_i = (start_offset + start + min_len - 1) >>
3718 offset = start_offset;
3722 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
3725 if (start + min_len > eb->len) {
3726 printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
3727 "wanted %lu %lu\n", (unsigned long long)eb->start,
3728 eb->len, start, min_len);
3733 p = extent_buffer_page(eb, i);
3734 kaddr = kmap_atomic(p, km);
3736 *map = kaddr + offset;
3737 *map_len = PAGE_CACHE_SIZE - offset;
3741 int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
3742 unsigned long min_len,
3743 char **token, char **map,
3744 unsigned long *map_start,
3745 unsigned long *map_len, int km)
3749 if (eb->map_token) {
3750 unmap_extent_buffer(eb, eb->map_token, km);
3751 eb->map_token = NULL;
3754 err = map_private_extent_buffer(eb, start, min_len, token, map,
3755 map_start, map_len, km);
3757 eb->map_token = *token;
3759 eb->map_start = *map_start;
3760 eb->map_len = *map_len;
3765 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
3767 kunmap_atomic(token, km);
3770 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
3771 unsigned long start,
3778 char *ptr = (char *)ptrv;
3779 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3780 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3783 WARN_ON(start > eb->len);
3784 WARN_ON(start + len > eb->start + eb->len);
3786 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3789 page = extent_buffer_page(eb, i);
3791 cur = min(len, (PAGE_CACHE_SIZE - offset));
3793 kaddr = kmap_atomic(page, KM_USER0);
3794 ret = memcmp(ptr, kaddr + offset, cur);
3795 kunmap_atomic(kaddr, KM_USER0);
3807 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
3808 unsigned long start, unsigned long len)
3814 char *src = (char *)srcv;
3815 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3816 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3818 WARN_ON(start > eb->len);
3819 WARN_ON(start + len > eb->start + eb->len);
3821 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3824 page = extent_buffer_page(eb, i);
3825 WARN_ON(!PageUptodate(page));
3827 cur = min(len, PAGE_CACHE_SIZE - offset);
3828 kaddr = kmap_atomic(page, KM_USER1);
3829 memcpy(kaddr + offset, src, cur);
3830 kunmap_atomic(kaddr, KM_USER1);
3839 void memset_extent_buffer(struct extent_buffer *eb, char c,
3840 unsigned long start, unsigned long len)
3846 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3847 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3849 WARN_ON(start > eb->len);
3850 WARN_ON(start + len > eb->start + eb->len);
3852 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3855 page = extent_buffer_page(eb, i);
3856 WARN_ON(!PageUptodate(page));
3858 cur = min(len, PAGE_CACHE_SIZE - offset);
3859 kaddr = kmap_atomic(page, KM_USER0);
3860 memset(kaddr + offset, c, cur);
3861 kunmap_atomic(kaddr, KM_USER0);
3869 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
3870 unsigned long dst_offset, unsigned long src_offset,
3873 u64 dst_len = dst->len;
3878 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3879 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3881 WARN_ON(src->len != dst_len);
3883 offset = (start_offset + dst_offset) &
3884 ((unsigned long)PAGE_CACHE_SIZE - 1);
3887 page = extent_buffer_page(dst, i);
3888 WARN_ON(!PageUptodate(page));
3890 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
3892 kaddr = kmap_atomic(page, KM_USER0);
3893 read_extent_buffer(src, kaddr + offset, src_offset, cur);
3894 kunmap_atomic(kaddr, KM_USER0);
3903 static void move_pages(struct page *dst_page, struct page *src_page,
3904 unsigned long dst_off, unsigned long src_off,
3907 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3908 if (dst_page == src_page) {
3909 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
3911 char *src_kaddr = kmap_atomic(src_page, KM_USER1);
3912 char *p = dst_kaddr + dst_off + len;
3913 char *s = src_kaddr + src_off + len;
3918 kunmap_atomic(src_kaddr, KM_USER1);
3920 kunmap_atomic(dst_kaddr, KM_USER0);
3923 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
3925 unsigned long distance = (src > dst) ? src - dst : dst - src;
3926 return distance < len;
3929 static void copy_pages(struct page *dst_page, struct page *src_page,
3930 unsigned long dst_off, unsigned long src_off,
3933 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3936 if (dst_page != src_page) {
3937 src_kaddr = kmap_atomic(src_page, KM_USER1);
3939 src_kaddr = dst_kaddr;
3940 BUG_ON(areas_overlap(src_off, dst_off, len));
3943 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
3944 kunmap_atomic(dst_kaddr, KM_USER0);
3945 if (dst_page != src_page)
3946 kunmap_atomic(src_kaddr, KM_USER1);
3949 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3950 unsigned long src_offset, unsigned long len)
3953 size_t dst_off_in_page;
3954 size_t src_off_in_page;
3955 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3956 unsigned long dst_i;
3957 unsigned long src_i;
3959 if (src_offset + len > dst->len) {
3960 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
3961 "len %lu dst len %lu\n", src_offset, len, dst->len);
3964 if (dst_offset + len > dst->len) {
3965 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
3966 "len %lu dst len %lu\n", dst_offset, len, dst->len);
3971 dst_off_in_page = (start_offset + dst_offset) &
3972 ((unsigned long)PAGE_CACHE_SIZE - 1);
3973 src_off_in_page = (start_offset + src_offset) &
3974 ((unsigned long)PAGE_CACHE_SIZE - 1);
3976 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3977 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
3979 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
3981 cur = min_t(unsigned long, cur,
3982 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
3984 copy_pages(extent_buffer_page(dst, dst_i),
3985 extent_buffer_page(dst, src_i),
3986 dst_off_in_page, src_off_in_page, cur);
3994 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3995 unsigned long src_offset, unsigned long len)
3998 size_t dst_off_in_page;
3999 size_t src_off_in_page;
4000 unsigned long dst_end = dst_offset + len - 1;
4001 unsigned long src_end = src_offset + len - 1;
4002 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4003 unsigned long dst_i;
4004 unsigned long src_i;
4006 if (src_offset + len > dst->len) {
4007 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4008 "len %lu len %lu\n", src_offset, len, dst->len);
4011 if (dst_offset + len > dst->len) {
4012 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4013 "len %lu len %lu\n", dst_offset, len, dst->len);
4016 if (!areas_overlap(src_offset, dst_offset, len)) {
4017 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
4021 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
4022 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
4024 dst_off_in_page = (start_offset + dst_end) &
4025 ((unsigned long)PAGE_CACHE_SIZE - 1);
4026 src_off_in_page = (start_offset + src_end) &
4027 ((unsigned long)PAGE_CACHE_SIZE - 1);
4029 cur = min_t(unsigned long, len, src_off_in_page + 1);
4030 cur = min(cur, dst_off_in_page + 1);
4031 move_pages(extent_buffer_page(dst, dst_i),
4032 extent_buffer_page(dst, src_i),
4033 dst_off_in_page - cur + 1,
4034 src_off_in_page - cur + 1, cur);
4042 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4044 struct extent_buffer *eb =
4045 container_of(head, struct extent_buffer, rcu_head);
4047 btrfs_release_extent_buffer(eb);
4050 int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
4052 u64 start = page_offset(page);
4053 struct extent_buffer *eb;
4056 spin_lock(&tree->buffer_lock);
4057 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4059 spin_unlock(&tree->buffer_lock);
4063 if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
4069 * set @eb->refs to 0 if it is already 1, and then release the @eb.
4072 if (atomic_cmpxchg(&eb->refs, 1, 0) != 1) {
4077 radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4079 spin_unlock(&tree->buffer_lock);
4081 /* at this point we can safely release the extent buffer */
4082 if (atomic_read(&eb->refs) == 0)
4083 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);